iiilililiilliiii'itllflliiii' ■^^^^^^^ ,1 r^ l-T) r-q 5 1-0 <— □ □ 1 = S r^ O m □ THE VOYAGE OF H.M.S. CHALLENGER. ZOOLOGY-VOL. XVIM. SECOJfD PART. REPORT (2/2- '■»c . ^ ON THE SCIENTIFIC RESULTS OF THE VOYAGE OF H.M.S. CHALLENGER DURING THE YEARS i87 3-7 6 UNDER THE COMMAND OF Captain GEORGE S. NARES, R.N., F.R.S. AND THE LATE ^,rF^>v Captain FRANK TOURLE THOMSON, R.N. PREPARED UNDER THE SUPERINTENDENCE OF THE LATE Sir C. WYVILLE THOMSON, Knt, F.R.S., &c. REGIUS PROFESSOR OF NATURAL HISTORY IN THE UNIVERSITY OF EDINBURGH DIRECTOR OF THE CIVILIAN SCIENTIFIC STAFF ON BOARD AND NOW OF JOHN MURRAY ONE OF THE NATURALISTS OF THE EXPEDITION MARINE BIOLQGICAL LABORATORY LIBRARY WOODS HOLE, MASS. W. H. 0. I Zoology— Vol. XVIII. SECOND PART Pul)U'sl)eri b|) <0i-liei- of i^er Jflajestp's (Soliernmeut PRINTED FOR HER MAJESTY'S STATIONERY OFFICE AND SOLD BY LONDON :— EYRE & SPOTTISWOODE, EAST HARDING STREET, FETTER LANE EDINBURGH :— ADAM & CHARLES BLACK DUBLIN :— HODGES, FIGGIS, & CO. 1887 Price {in Two Parts, with a Volume of Plates) £'^, \os. PRINTED BY NEILL AND COMPANY, EDINBURGH, KOK HER majesty's STATIONERY OFFICE. 5 r (^ / / CONTENTS. Report on the Radiolaria collected by H.M.S. Challenger during the years 1873-1876. By Ernst Haeckel, M.D., Ph.D., Professor of Zoology in the University of Jena. SECOND PART.— OSCULOSA. (NASSELLARIA AND PHvCODARIA.) CONTENTS. SECOND PART. II. Subclass OSCULOSA Legion III. NASSELLARIA vel MONOPYLEA, Order 11. Nassoidea, ,, 12. Plectoidea, „ 13. Stephoidea, „ 14. Spyroidea, ,, 15. botryodea, „ 16. Ctrtoidea, Legion IV. PH^EODARIA vel CANNOPYLEA, Order 17. Ph^ocystina, „ 18. Ph^08ph.€:ria, ,, 19. Ph^ogromia, „ 20. Ph^oconchia, Note on the Dimensions and Mbascrbmbnts, ADDENDA, ...... ERRATA, INDEX, ....... PAGE 889 889 895 898 931 1015 1103 1126 1521 1542 1590 1642 1710 1760 1761 1763 1765 EEPOET ON THE RADIOLARIA, 889 Legion III. NASSELLARIA, vel Monopylea, vel Monopylaria (Pis. 51-98). Nassellaria (inclusis Spj^ridinis), Ehrenberg, 1875. Monopylea, Hertwig, 1879. Monopylaria, Haeckel, 1881. Cyrtida et AcantJwdesmida, Haeckel, 1862. Definition. — Radiolaria with simple membrane of the central capsule, which is monaxou or bilateral, and bears on one pole of the main axis a porous area (porochora), forming the base of a peculiar intracapsular cone (podoconus). Extra- capsulum without phseodium. Skeleton siliceous, very rarely wanting. Fundamental form originally monaxon, often dipleuric or bilateral. The legion Nassellaria vel Monopylea, in the extent here defined, was constituted in 1879 by Richard Hertwig in his work Der Organismus der Radiolarien (pp. 133—137). He gave to this large group the rank of an order, and united in it the two families Acanthodesmida and Cyrtida, which I had constituted fii'st in 1862 in my Monograph (pp. 237, 265, 272) ; but he added, too, as a third family the Plagiacanthida, united by me with the former. In the first system of Ehrenberg (1847, loc. cit., pp. 53, 54), four families belonging to the Monopylea were enumerated, the Halicalyptrina, Lithochytrina, Eucyrtidina, and Spyridiua. He united the three former under the name " Polycystina solitaria," which he afterwards changed into Nassellaria (1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 157). In my Monograph of the Radiolaria (1862, pp. 265—345) forty -four genera of Nassellaria were enumerated (six Acanthodesmida and thirty-eight Cyrtida), whilst the total number of genera in the whole class of Radiolaria at that time amounted to one hundred and thirteen. But owing to the astonishing number of new and interesting forms of this legion which I afterwards detected in the collection of the Challenger, in 1881 I distinguished in my Prodromus not less than three hundred and seventeen genera. These were disposed in fi^ve large main groups, retained in the jiresent Report, with twenty-six families, viz., (1) Plectoidea (with three families), (2) Ste- p h o i d e a (with four families), (3) Spyroidea (with four families), (4) Botryodea (with three families), and (5) Cyrtoidea (with twelve families). The first two groups have an incomplete or rudimentary skeleton, and may be united in the order Plectellaria, whilst the other three families possess a complete latticed shell, and (ZOOL. CHALL. ESP. PART XL. 1889.) Ef 112 890 THE VOYAGE OF H.M.S. CHALLENGER. may be uuited as Cyr tell aria. The former correspond to the Acanthodesmida, the latter to the .Cyrtida in my Monograj^h. The character common to all Monopylea or Nassellaria, which separates them from all other Radiolaria, was first recognised by Richard Hertwig in 1879, and consists in the singular structure of the monaxonian central capsule, bearing on the basal pole a peculiar porous area or operculum, the "Porenfeld;" we call it shortly the " porochora." It represents a circular or elliptical porous plate on the basal pole of the vertical main axis of the central capsule, and bears a peculiar " podoconus " or " Pseudopodien-Kegel," a conical body of singular structure, protruding inside the membrane into the capsule. The pseudopodia arising from this peculiar " podoconus " proceed from the capsule piercing the " porochora," whilst the other parts of the capsule are not perforated. The MoNOPYLEA are therefore " Merotrypasta," like the following fourth legion, the Ph.^odaria or Cannopylea. But in these latter we find on the basal pole of the monaxonian capsule only one single large main opening, prolonged into a peculiar tube, and there is no trace of the typical " podoconus," characteristic of all Nassellaeia. The latter agree, however, with the former in the possession of a basal opening, serving for the emission of the pseudopodia, and in the monaxonian fundamental form, arising from this structure. Therefore these two legions of " Merotrypasta " exhibit a wider divergence from the Acantharia and Spumellaeia, the two legions of " Holotrypasta," in which the central capsule is everywhere perforated by innumerable small pores (com- pare above, pp. 5, 6, 716). Tlie Skeleton in all Nassellaria consists either of pure silica, or of a peculiar silicate ; never of acanthin (as in all Acantharia). The siliceous bars and beams constituting it are invariably solid (as also in the Spumellaria) ; never hollow (as in the Ph^odaeia). In the small family of Nassellida alone (with the two genera Cystidium and Nassella) the skeleton is entirely absent. In all other genera of Nassellaria the siliceous skeleton is more or less developed ; imperfect, or quite rudimentary in the Plectellaria (Plectoidea and S t e p h o i d e a), but perfect and forming a regular lattice-shell in the C y r t e 1 1 a r i a (S p y r o i d e a, Botryodea, and C y r t o i d e a). The different forms of this skeleton exhibit an extraordinary variety, but may be reduced to a few very simple fundamental forms, or even to a single, most simple original form. The comparative morphology is more interesting, but also more difficult to understand than in any other Radiolaria. The geometrical fundamental form of the skeleton is in all Nassellaria monaxonial, the vertical main axis of the body, which is already indicated by the axis of the central capsule with two difi'erent poles, being also expressed constantly in the form of the skeleton. The lower or basal pole of the latter always exhibits a difierent shape from that of the upper or apical pole. This difi"erence is so striking in nearlj^ all Monopylea, that the two poles may be determined on the first view. REPORT ON THE RADIOLARIA. 891 In the great majority of Nassellaria not ouly is the monaxonial fundamental form expressed, but also the dipleuric or l)ilateral, so that the symmetrical halves of the body may be easily determined ; the riglit and left halves exhibit the same symmetry as in the vertebrates, so that we may distinguish an anterior ventral and a posterior dorsal face of the body. The whole form is in this case determined by three dimensive axes, perpendicular to one another, two of which are heteropolar, the third is homoeopolar. The apical pole of the vertical main axis (principal or longitudinal axis) is difi'erent from the basal j)ole. The ventral pole of the horizontal sagittal axis (or dorso-ventral axis) is different from the dorsal pole. The right pole of the horizontal transverse axis (lateral or frontal axis) is equal to the left pole. Therefore the sagittal or median plane of the body (in which the principal and the sagittal axis are crossed) divides it into symmetrical equal halves and is perpendicular to the frontal axis. Three different original elements of structure are recognisable in the majority of Nassellaria, viz., (l) a vertical simple ring, the primary or sagittal ring, placed vertically in the sagittal plane and enclosing the median plane of the central capsule ; (2) a basal tripod, composed of three diverging radial rods, which are united on the basal pole of the central capsule and are either expanded horizontally or descend ; (3) an ovate or subspherical, simple lattice-shell, the cephalis or capitulum, w^hich sur- rounds the central capsule and exhibits a peculiar structure on its basal pole. These three important original elements of structure — the sagittal ring, the basal tripod, and the latticed cephalis — are so united in the majority of Nassellaria that the cephalis rests upon the tripod and includes the sagittal ring wholly or partially. The simplest realisation of this typical union is afforded by the Archiperida and Tripospyrida, and these may be derived from the simpler important Stephanid Cortina (PL 83, fig. 9 ; PI. 92, fig. 21 ; PL 97, fig. 1). In this and in all other tripodal Nassellaria, the three basal rods or the " cortinar feet " are constantly so arranged that an odd or posterior rod, the " caudal foot " [c) is opposed to the two anterior paired rods, the " pectoral feet " (one right, p", and one left, p'). The caudal foot lies in the sagittal plane, and is prolonged upwards into the dorsal rod of the sagittal ring (h), and over this in a free ascending spine, the " apical horn " (a). The curved ventral rod of the ring [r) is united above with the base of the apical horn, below with the common centre of the tripod or the " cortinar centrum." The characteristic position of the central capsule in this skeleton of Cortina is such that its basal pole (with the porochora) rests upon the centre of the tripod, w^hilst its sagittal perimeter is separated from the surrounding ring by the calymma ; the numerous pseudopodia arising from its base diverge downwards and are supported and protected by the three basal feet of the tripod (PL 97, fig- !)• Compare also Pis. 51, 53, 84, 95, 98. The typical skeleton of Cortina, a tripodal ring, becomes more developed in the Semantid Cortiniscus, in which the basal parts of the three diverging feet are united 892 THE VOYAGE OF H.M.S. CHALLENGER. by a second horizontal ring, the cortinar or basal ring (PI. 92, figs. 11-13). The pores between the former and the latter, or the " cortinar pores," may be regarded as the first beginning of the lattiee-j)late, composing the " cephalis " or the simple primordial shell in the Archiperida and Tripospyrida, and transmitted from these by heredity to the great majority of Nassellaeia. The "cephalis or capitulum " (the "Kopfchen" of the German authors) is therefore the most important part of the skeleton in all C y r t e 1 1 a r i a, or in all Nassellaria possessing a complete lattice-shell. In the Plectellaria, however, or in those Nassellaria which do not j)ossess a complete fenestrated shell, the " cephalis " is either imperfect or totally wanting. The cephalis surrounds the enclosed central capsule on all sides in the form of an ovate or subspherical lattice -shell, and is separated from it only by the jelly-like calymma. The sagittal ring is either enclosed in the wall of the cephalis (wholly or partially), separating its two lateral halves, or it is enclosed in the cavity of the cephalis and connected with its sagittal perimeter by short beams. The base of the cei^halis (with the cortinar plate) often rests immediately upon the centre of the tripod ; in the majority of Nassellaria, however, this near relation is altered by reason of later changes and secondary modifications. The number of various forms, developed from these simple original structural elements of the skeleton, is astonishing, and there are described more than three hundred genera and nearly two thousand species of this legion in the following pages. This large number may be easily increased by subsequent observers. Since in all these Monopylea the characteristic structure of the central capsule is identical, and also the structural elements of the siliceous skeleton are similar, it is very probable that they may have arisen from a single common stock. But it is very difficult (and at present impossible) to explain a natural monophyletic system of this large legion. The greatest difficulty is presented by the fact that the three structural elements mentioned above, viz., the sagittal ring, the basal tripod, and the latticed cephalis, are not constantly united, but each alone may also constitute the skeleton by itself In this respect the following seven cases are possible, and are actually realised. A. The skeleton is com^josed of the sagittal ring only and of its spiny appendages, without basal tripod and without latticed cephalis. This is the case in the majority of Stephoidea (Stephanida, Semantida, Coronida, and Tympanida). B. The skeleton is composed of a basal tripod only (Plagiacantha), or of a tripod in the centre of which arises a vertical apical horn (Plagoniscus), and often of an irregular framework, arising from the rods of the tripod; but there is neither a trace of a sagittal ring nor a complete latticed cephalis. This is the case in the remarkable suborder Plectoidea (Plagonida and Plectanida). C. The skeleton is composed of a latticed cephalis only, a simple ovate or sub- spherical fenestrated shell, which encloses the monopylean central capsule; there is no REPORT ON THE RADIOLARIA. 893 trace of a sagittal ring nor of a basal tripod. This is the case in the remarkable family of Cyrtocalpida (Archicorida and Ai'chicapsida), in numerous Botryodea and in other C y r t e 1 1 a r i a. D. The skeleton is composed of a sagittal ring and a basal tripod, without latticed cephalis. This is the case in a few, but very important forms of Stephoidea: Cortina, Stephanium, Cortiniscus, Stephaniscus, Podocoronis, and some allied genera. E. The skeleton is composed of a sagittal ring and a latticed cephalis, but without basal tripod. This is the case in numerous Cyrtellaria, in the Circospyrida (or Zygospyrida apoda: Dictyospyris, Circospyris) and some other Spyroidea; and in a large number of Botryodea and Cyrtoidea eradiata (a part of the Sethocyrtida, Theocyrtida, Lithocampida, and others). F. The shell is composed of a basal tripod and a latticed cephalis, but without any trace of the sagittal ring. This is the case in numerous Cyrtoidea trii'adiata and multii-adiata, and perhaps in the majority of the following families — Tripocalpida, Tripocyrtida, Podocyrtida, and Podocampida. G. The shell is composed of all three above-mentioned elements, of a sagittal ring, a basal tripod, and a latticed cephalis. This is the case in the great majority of Spyroidea (with a few exceptions only), and perhaps also in the majority of Cyrtoidea. The survey of these seven groups, A to G, each of which is represented by numerous living forms, shows clearly how difficult and complicated the morphology and phylogeny of the numerous Nassellaeia must be. For all possible combinations of the three original structural elements are realised abundantly, and in such compli- cated relations, and so intermiua;led in the different orders and families, that it seems nearly hopeless to answer the question of theii- true origin. The identity in the structure of the central capsule, however, in all these Monopylea, makes it probable that they have all arisen originally from the skeletonless Nassellida (Cystidium, Nassella), either in a monophyletic or in a polyphyletic w^ay. In this respect the following phylogenetical hypotheses are possible. 1. Monophyletic hypothesis, deriving all Nassellaeia from a simple sagittal ring {Archicircus, Lithocircus, &c., PL 81). The groups A, D, E, and G may be derived easily from such a ring, but the groups B, C, and F only by means of the hypothesis that the original ring may be completely reduced and finally lost. This hypothesis was stated by me in the years 1877 to 1879, when I had got the first general survey of the astonishing number of new Nassellaeia in the Challenger collection, and as I had found the sagittal ring in the majority of them. This, my former hypothesis, is mentioned by Ptichard Hertmg (1879, loc. cit., pp. 68, 126). It was afterwards supported wdth particular energy by 0. Bhtschli (1882, Zeitschr. fiir wiss. Zool., Bd. XXXVL). 2. ]\lonophyletic hypothesis, deriving all Nassellaeia from a basal tripod {Triplagia, Plagoniscus, &c., PI. 91). The groups B, D, F, and G, all trii-adiate, may 894 THE VOYAGE OF H.M.S. CHALLENGEE. be derived easily from such a tripod ; but the groups A, C, and E only by means of the hypothesis that the original tripod may be completely reduced and finally lost. This hypothesis was employed in 1881 in my Prodromus, since I had convinced myself that the " triradial structure " is prevalent in the great majority of Nassellakia, and is perhaps more important than the sagittal ring. 3. Monophyletic hypothesis, deriving all Nassellaeia from a latticed cephalis, a simple ovate or subspherical fenestrated shell without ring and trij)od [Cyrtocalpis, Archicapsa, &c.). The groujjs C, E, F, and G may be derived easily from such a cephalis, but the groups A, B, and D only by means of the hypothesis that the sagittal ring as well as the basal trijiod may remain as the last remnants of a reduced cephalis. This hypothesis was given in 1862 in my Monograph, where I constructed the' first pedigree of Eadiolaria (j). 234). I there derived all the Cyrtida from the Sphseroidea {Cyrtidosphccra), supposing that Cyrtocalpis and some other Monocyrtida may form a dii'ect phylogenetical passage from the Sphseroidea to the Cyrtoidea. 4. Polyphyletic hypotheses, deriving the different groups of Nassellakia from different skeletonless Nassellida, by development of simple siliceous skeletons in different ways. Among the numerous polyphyletic hypotheses which are possible, one of the simplest would be the supposition that three different fundamental forms of skeleton may have arisen independently one from another : (l) a simple sagittal ring as original form of the Stephoidea and Spyroidea (A) ; (2) a simple basal tripod as original form of the Plectoidea (B) ; (3) a simple latticed cephalis as original form of the Botryodea and Cy rt oidea (C). This triphyletic hypothesis is supported by R. Hertwig (1879, loc. cit, p. 136) ; he assumes that the original skeletonless Nassellida (Ci/stidium) have produced three different branches, his " Acanthodesmida " ( = Stephoidea and Spyroidea) with a primary ring, his " Plagiacanthida " ( = Plectoidea) with a primary tripod, and his Cyrtida (=:Botryodea and Cyrtoidea) with a primary cephalis. This hypothesis seems rather probable on the first view ; but it meets with the greatest difficulties in view of the fact that these three original elements of the skeleton are more or less evidently combined in the great majority of Nassellakia. The greatest difficulty arises from the fact that often among very similar and closely allied forms the first exhibits all three elements (A, B, C) com- bined, whilst the second has a combination of A and B, the third of B and C, the fourth of A and C ; and there are other forms, very similar to the former, in which one element only is recognisable. Another difficulty arises from the fact that the intimate structure of the cephalis in the majority of C y r t e 1 1 a r i a is not perfectly known, and often exhibits structures which are difficult to explain with regard to the three elements A, B, C. Under these cii'cumstances further researches on the numerous imperfectly known Nassellakia are required, and chiefly accurate observations on their more minute structure and on their important ontogeny. REPORT ON THE EADIOLARIA. 895 We divide tlie immense legion of Nassellaeia into two large orders, the Plectellaria without complete lattice-shell, and the Cyrtellaria with a complete lattice-shell or a "cephalis," including the central capsule; the latter, of course, have arisen from the former. The Plectellaria comprise three different suborders, the Nassoidea (without skeleton), the Plectoidea (with a tripodal skeleton, -ndthout ring), and the Stephoidea (with a primary sagittal ring, with or without tripod). The Cyrtellaria again also comprise three different suborders, the Spyroidea (with bilocular cephalis and a sagittal constriction), the Botryodea (with multilocular and lobate cephalis, exhibiting two or more constrictions and three or more lobes), and the C y r t o i d e a (with simj)le, unilocular cephalis, without con- striction). I. Order PLECTELLARIA. Nassollaria without complete lattice-shell. Synopsis of the Orders and Suborders of Nassellaria. ' No skeleton, . . . .L Nassoidea. Skeleton with a basal tripod, without IL Order CYRTELLARIA. NasseUaria with a complete lattice-shell. 2. Plectoidea. Skeleton with a sagittal ring (usually without tripod), . . . 3. Stephoidea. Cephalis bilocular, with a sagittal con- striction, . . . . 4. Spyroidea. Cephalis multilocular, with two or more constrictions and lobes, . . 5. Botryodea. Cephalis simple, without constriction and lobes, . . . . . 6. Cyrtoidea. Order V. PLECTELLAEIA, Haeckel, 1883. Definition. — Nassellaeia without complete lattice-shell, usually with an incomplete skeleton, formed of a ring, a tripod, or an irregular framework. Suborder I. NASSOIDEA, Haeckel. Definition. — Nassellaeia without skeleton. Single family Nassellida. 896 THE VOYAGE OF H.M.S. CHALLENGER. Family XLV. Nassellida, Haeckel. Cystidina, Haeckel, 1883, Sitzungsb. Jena Ges. fiir Naturw., Februar 16. Definition. — Nassellaria without skeleton. The soft bod};- composed of a mouopylean central capsule (with porochora and podoconus) and of a surrounding jelly-veil or calymma. The family N a s s e 1 1 i d a comprises the simplest and most primitive forms of Nassellakia, the only group which is entirely without a skeleton. The central capsule is therefore perfectly free and naked, enveloped by the calymma only, as in the C 0 1 1 o i d e a among the Spumellaria, in the Phseodinida among the Ph^eodaria. Probably these naked and skeletonless Monopylea must be regarded as surviving remnants of the common ancestral group of this legion ; but the possibility is not excluded that the few observed forms are either young Nassellakia which have not yet secreted a skeleton, or older Nassellaria which have lost their original skeleton. We distinguish in this small family two genera only : Cystidium with hyaline, not foamy calymma, without extracapsular alveoles, and Nassella, with a very voluminous foamy calymma, including numerous large alveoles ; the former corresponds to Actissa and the latter to Tlialassicolla among the Colloideaor the skeletonless Spumellaria. But in these two latter genera, as in all Peripylea, the central capsule is perforated everywhere by innumerable small pores ; the two former genera, however, exhibit the same characteristic podoconus in the central capsule, and the same porochora at its base, as all the other Monopylea. The pseudopodia are protruded from the central capsule through the porochora only. The. Central Capsule is in the two observed genera either ovate or nearly spherical, usually slightly tapering towards the basal mouth. Its transverse section is constantly circular. The membrane of the capsule is usually rather thick and double-contoured, and bears on the truncate basal pole a circular " porochora " or area porosa, through which the pseudopodia are protruded. The iwrochara is either quite simple, circular, or in some species trilobed, with three ecjual circular lobes, each of which is surrounded by a girdle of small granules. The podoconus, or " pseudopodial-cone," arising vertically from the horizontal basal porochora, is half as long as the central capsule, or longer, simply conical and finely striped longitudinally. The nucleus lies usually in the upper- most part of the central capsule, above or behind the podoconus, and is either spherical or ovate, sometimes kidney-shaped. It includes one or more nucleoli. Synopsis of the Genera of Nassellida. Calymma hyaline, without alveoles, ....... 382. Cystidium. Calymma foamy, with uumorous large alveoles, ..... 383. Nassella. REPORT ON THE RADIOLARIA. 897 Genus 382. Cystidium^ R Hertwig, 1879, Organismus d. Eadiol., p. 87. Definition. — N assellida with hyaline calynima, without extracapsular alveoles. The genus Cystidium is the simplest and most primitive among all Nassellaria, and may be regarded as the common ancestral form of this legion, for which it has the same high importance as Actissa for the Spumellaeia. The central capsule is quite simple, ovate or nearly spherical, and included in a voluminous hyaline calymma, which contains no large alveoles. Cystidium differs from Actissa, its probable ancestral form, in the possession of the " podoconus " and its basal " porochora," characteristic of all Nassellama or Monopylea. 1. Cystidium princeps, n. sp. (PI. 91, fig. 1). Central capsule ovate, one and a thii-d times as long as broad. Podoconus with simple circular porochora, about half as long as the capsule, surrounded at its base by red granules of pigment. Nucleus spherical. Three equal oil-globules in the endoplasm. No pigment in the voluminous calymma, which includes numerous xantheUs. Dimensions. — Length of the central capsule O'l, breadth 0"075 ; nucleus 0"035. Habitat. — Indian Ocean, Maldive Islands (Haeckel), surface. 2. Cystidium lecythium, n. sp. Central capsule ovate, one and a half times as long as broad. Podoconus with simple circular porochora, three-fourths as long as the capsule. Nucleus ellipsoidal. No oil-globules in the endoplasm. No pigment and no xantheUffi in the calymma. Dimensions. — Length of the central capsule 0'12, breadth O^OS ; nucleus 0-04. Habitat. — Central Pacific, Station 271, surface. 3. Cystidium inerme, R. Hertwig. Cystidium inerme, R Hertwig, 1879, Organismus d. Radiol., p. 87, Taf. vii. figs. l-lb. Central capsule subspherical, a httle longer than broad. Podoconus about two-thirds as long as the capsule, with trifid porochora, which is composed of three equal circular lobes. Nucleus spherical. Numerous oil-globules m the endoplasm. The calymma includes numerous xauthellge and brown pigment around the mouth. Dimensions. — Length of the central capsule 0*06, breadth 0'05 ; nucleus 0'03. Hciibitat. — Mediterranean, Messina (E. Hertwig), surface. 1 C)/sfidmm= Small vesicle ; kv/ttHiou. (ZOOL. CHALL. EXP. — PAET XL. — 1885.) Rr 113 898 THE VOYAGE OF H.M.S. CHALLENGER. Genus 383. NasseUa,'^ nov. gen. Definition. — Nassellida with foamy calymma, containing numerous large extracapsular alveoles. The genus Nassella differs from the preceding Cystidium, its probable ancestral form, in the development of numerous large alveoles in the extracapsular calymma, and therefore exhibits the same relation to it that Thalassicolla bears to Actissa among the Spumellakia. The foamy calymma is very voluminous, and includes numerous symbiotic xanthellse. 1. Nassella thalassicolla, n. sj). Central capsule spherical. Podoconus with simple circular porochora, half as long as the capsule. Nucleus spherical. Numerous oil-globules in the endoplasm. Calymma spherical, without pigment, with numerous xantheUte and large alveoles. Dimensions. — Diameter of the central capsule 012, nucleus 004, calymma 0-6. Habitat. — South Pacific, Station 300 (off Juan Fernandez), surface. 2. Nassella nassiterna, n. sp. Central capsule ovate. Podoconus two-thirds as long as the capsule, trifid, with three equal circular lobes (as in Cystidimn inerme). Nucleus ovate. Three equal large oil-globules in the endoplasm, corresponding to the three lobes of the porochora. Calymma ovate, in the upper half much more voluminous than in the lower, including nimierous large alveoli and xanthellse, and around the mouth masses of black pigment. Dimensions. — Diameter of the central capsule O'l, nucleus O'Oo, calymma 0'8. Habitat. — Indian Ocean, Madagascar (Eabbe), surface. Suborder II. PLECTOIDEA, Haeckel. Plectoidea vel Plectida, Haeckel, 1881, Prodromus, p. 423. Plagiacanthida {sensu ampliori), R. Hertwig, 1879, Organismus d. Radiol., p. 72. Definition. — Nassellaria with a rudimentary, originally tripodal skeleton, composed of radial spines, arising from one common central point or central rod ; the spines are simple or branched, and the branches may form by concrescence of their meeting ends a loose wickerwork, but never a complete lattice-shell. Never a ring in the skeleton. ' i\'cMS(!Zto — Small wicker cage for flsbinc. REPORT ON THE RADIOLARIA. 899 The suborder Plectoidea, hitherto known by few species only of "Plagiacanthida," comprises a large numlier of interesting Nassellaria, which belong partly to the simplest and most primitive forms of this legion. It may be divided into two different families, Plagonida and Plectanida. In the first family, Plagonida, the monopylean central capsule is supported by a simple or rudimentary skeleton, composed only of a variable number of radial spines united in a common centre. In the second family, Plectanida, the branches of these radial spines become united and form a loose irregular framework with wide meshes, partly enclosing the central capsule, but never a perfect lattice-shell. The Plectoidea dilier from the following suborder, the S t e p h o i d e a, in the absence of the ring, characteristic of the latter. Some slight traces, however, indicate a near affinity between the ringless Plectoidea and the ring-bearing Stephoidea. Both these suborders of Plectellaria differ from the closely allied Cyrtellaria (Spyroidea, Botryodea, and Cyrtoidea) in the absence of a complete lattice-shell. The morphological relation and phylogenetic affinity between the former and the latter have already been discussed in the preceding description of the legion Nassellaria (compare pp. 891—894). The first known species of Plectoidea was observed in the North Atlantic (on the Norwegian shore) in 1855 by my late friend Edouard Claparede, and described and figured in his Etudes, &c. (1858), under the name Plagiacantha arachnoides. He considered it as a new genus of Acanthometrina. Another species, from the Mediterranean, was described in the same year by Johannes Miiller as Acanthodesmia dumetum (1858, loc. cit., Ta£ i. fig. 3). A third species, also Mediterranean, was figured by me in 1865 under the name Acanthodesmia polyhroclia. Finally, Richard Hertwig, 1879, in his Organismus der Radiolarien, gave a very accurate description of another Mediterranean form, Plagiacantha ahietina (loc. cit., Taf. vii. fig. 6). He first reco2;nised the true character of Monopylea in their monaxonian central capsule, and observed at the same time the first Nassellarium without skeleton, called by him Cyrtidium inerme {loc. cit., Taf. vii. fig. 1). To these four known species, representing three different genera, the rich collection of the Challenger has added so many new forms that we may distinguish here not less than seventeen genera and sixty-one species. In my Prodromus (1881, p. 423) I arranged these in two subfamilies, the Plagonida and Plectanida, constituting together the family Plectida (identical with the " Plagiacanthida " of Hertwig and Biitschli). But at present, regarding the important relations of these Plectida to the other Nassellaria, it seems more con- venient to give to them the rank of an independent suborder of Radiolaria, under the name Plectoidea. The peculiar structure of the central capsule of the Plectoidea, first recognised by Richard Hertwig, allows no doubt of their being true Monopylea or Nassellaria ; and also their siliceous, originally trii'adiate skeleton indicates the nearest affinity to 900 THE VOYAGE OF H.M.S. CHALLENGER. the other families of this legion. But a very difficult and as yet unsolved problem is the important question, in what manner these different groups of Nassellaria are phylogenetically connected. Either the Plectoide a — as the simplest of all — are the original common ancestral group of this whole legion (as I assumed in my Prodromus, 1881), or they are derived from the Stephoidea (by reduction of the sagittal ring), or they have originated independently from them (if we sujapose a poly- phjdetic origin of the Monopylea. Compare above, p. 893, &c.). In any case the typical " triradial structure " of the Plectoide a, prevalent also in the other groups of this legion, is a very important and interesting fact. The triradial skeleton of the Plectoidea exhibits in the two families of Plagonida and Plectanida a complete homology of development, so that each genus of the latter may be derived from a corresponding genus of the former, simjily arisen by concrescence or union of the branches of the radial spines. Therefore the only difference between the two closely allied families is, that the branches of the radial spines in the Plagonida remain free, whilst in the Plectanida they produce a loose framework or wickerwork by union of their meeting ends. We express this complete homology in the nomenclature of the Plectoidea, in each genus of Plagonida retaining the syllable " Plag-" ; in each genus of Plectanida, correspondingly, the syllable "Plect-." The number of radial spines composing the skeleton is originally three, and in all not triradial genera is probably derived from three. For better survey we may divide each family, according to the different number of rays, into four different subfamilies : A, with three radial spines (Triplagida and Triplectida) ; B, with four radial spines (Tetraplagida and Tetraplectida) ; C, with six radial spines (Hexaplagida and Hexaplectida) ; and D, with numerous (seven to nine or more) radial spines (Polyplagida and Polyplectida). The last three subfamilies have arisen probably from the first triradial subfamily, by a secondary increase in the number of rays. The important signification of the triradial structure, recurring in the most different groups of Nassellaria, has been akeady pointed out sufficiently by myself and by R. Hertwig. But the triradial Plectoidea offer also another interesting relation of this characteristic structure, some simple forms of this order appearing nearly identical with the isolated triradial spicula of certain B e 1 o i d e a (Thalassosphserida and Sphferozoida). Even some more complex quadriradial and sexradial forms of the latter reappear in exactly the same shape also in the former. This identity may be perhaps an important indication of true affinity (compare below). The simplest and probably the most original kind of triradial structure is exhibited by the genera Triplagia and Triplecta (PL 91, figs. 2, 7). Here three equal radial spines lie in one horizontal plane and are united in a common central point at equal angles, so that three lines connecting their distal ends form a regular equilateral triangle. Simple trii-adial spicula of the same regular form are also found in many EEPORT ON THE RADIOLARIA. 901 Beloidea [Lampoxanthium, Splicerozoum, &c., Pis. 2 and 4). The central capsule of these simplest Plectoidea (with vertical main axis) rests perpendicularly on the horizontal triangle, formed by the triradial skeleton ; the porochora of the former (or the " area porosa ") rests upon the central point of the latter. Another kind of triradial structure characterises the genera Plagiacantlia and Plectop)hora. The three radial spines united in the central point lie here not in one plane, but diverge in different planes, so that they correspond to the three lateral edges of a three-sided pyramid. Commonly the three spines are of equal size, and also the angles between them equal, so that the pyramid is regular, sometimes very flat, at other times more elevated. Spicula of exactly the same form are also found in some Beloidea. Probably the three divergent spines are homologous to the three basal feet of numerous Spyroidea and C y r t o i d e a. The central capsule, accord- ing to Hertwig, is placed in the apical part of the pyramid, the axes of both being identical, and the porochora resting in the apex itself. This fact seems to 'contradict the above-mentioned affinity ; but since in Trvplecta and Triplagia the three spines lie horizontally, they may have changed this original position in different direction, in Plagiacantha and Plectophora becoming divergent upwards, whereas in Plagoniscus and Plectaniscus (as in the Spyroidea and Cyrtoidea) directed dowTiwards. The triradial structure, common to the Triplagida and Triplectida, is replaced by the quadriradial structure in the Tetraplagida and Tetraplectida. Probably the latter have been derived from the former by development of a fourth spine, and then this latter would correspond to the "apical horn" of the other Nassellaria. But possibly also both struc- tures have originated independently from one another. We may distinguish not less than four different kinds of the quadriradial structure. In the first case all four spines are equal, and diverge from a common central point at equal angles in different direc- tions, corresponding to the four axes of a regular tetrahedron (Tetraplagia and Tetraplecta, PI. 91, figs. 3, 8). In the second case all four spines are also equal, 'bnt they are not united in a common central point, but opposite in pairs on the two poles of a common central rod (Plagonidium). Therefore the skeleton possesses here the same form as in the " geminate-biradiate " spicula of many Beloidea (e.g., Tlialassoxanthium bifurcum and Sphmrozoum furcatum). The development of the short horizontal middle rod, con- necting the two divergent pairs of spines, is here probably effected by the porochora of the central capsule resting upon it. Whilst in these two cases of quadriradial structure all four spines are equal, in two other cases they become differentiated in a very remarkable manner. One spine is vertically directed upwards, in shape and size different from the three others, which are directed dowTiwards ; the former corresponding probably to the " apical horn," the latter to the three "basal feet," which are found in the great majority of the Spyroidea 902 THE VOYAGE OF H.M.S. CHALLENGER. and Cyrtoidea. Therefore we' encounter here for the first time that characteristic " cortinar structure " which is complete in Cortina and Cortiniscus (PL 92, figs. 11—13, 21), and which may be regarded as the strongest argument for a close relationship, or even for a common monophyletic origin of all Nassellaria. The four spines, which we regard therefore as " cortinar spines," exhibit a twofold kind of central junction. In the simpler case they are united in a common central point, on which rests the porochora of the central capsule [Plagoniscus and Plectaniscus, PI. 91, figs. 4, 9). These forms are nearer to Cortina, and may be derived immedi- ately from Tetraplagia and Tetrwplecta by difierentiation of the four equal spines. In the other case the four cortinar spines are separated in pairs, diverging from the two poles of a short horizontal common " central rod " (Plagiocarpa and Periplecta, PI. 91, figs. 5, 10). These forms may be compared with the spicula of some Beloidea and derived from Plagonidium ; but their basal central rod may be compared again with the basal part of the sagittal ring of Cortina, and this comparison becomes very important in those forms like Plagiocarpa procortina (PI. 91, fig. 5). Here the four spines approach very nearly to those of Cortina; the two ventral spines (or pectoral feet) on the anterior pole of the middle rod are equal, but very different from the two dorsal spines, arising from the posterior pole ; the lower odd spine of the latter corresponds to the " caudal foot," the upper spine to the " apical horn " of Cortina and of the Cyrtellaria. The vertical plane, determined by these two dorsal spines, is the sagittal plane, and two opposite curved branches which lie in this plane (an upper arising from the basal part of the apical spine and a low^er arising from the anterior pole of the middle rod) may be regarded as ventral parts of an incomplete sagittal ring. This interesting form and some other similar Tetraplagida may be regarded either as beginning St ephoidea (Cor^wm, with incomplete sagittal ring) or as retrograde Stephoidea [Cortina, with jsartly reduced sagittal ring). In every case they seem to indicate the near relationship between the Stephoidea and Plectoidea. Another argument for this close relationship may be found in the position of the central capsule in the interesting genus Plagiocarpa (PI. 91, fig. 5). Its basal part (with the porochora) rests upon the common central rod, its ventral face upon the ventral prolongation of the latter, its dorsal face upon the apical horn ; its axis lies in the sagittal plane. The three basal spines (the odd caudal and the paired pectoral feet) diverge from its basal pole downwards in the same manner as in the Cortinida, the Zygospyrida and the Monocyrtida. Less important than those quadriradial Tetraplagida and Tetraplectida, are the sexradial Plectoidea, the Hexaplagida and Hexaplectida. These may be derived immediately from the triradial Plectoidea by prolongation of the three primary original spines (of Plagiacantha) over the common central point. Here also two REPORT ON THE RADIOLARIA. 903 different kinds of central junction are found. In the simpler case all six radial spines arise from a common central point [Hexaplagia and Hexaplecta). In the other case the six radial spines arise from the two poles of a short horizontal common central rod, opposed in two groups, each of three spines [Plagonium and Plectanium, PL 91, figs. 6, 11). In this latter case the single corresponding spines of the two opposite groups are usually parallel, and exhiliit therefore exactly the same characteristic " geminate- trii-adiate " form which is found in many Beloidea {e.g., in the common Sphcerozoum punctatum and the similar Lamp)Oxanthium punctatum). The fourth and last group of this suborder contains the multiradiate Plectoidea, the Polyplagida and Polyplectida. Here the number of radial spines, diverging from the common centre, exceeds six, and is commonly seven to nine, at other times ten to twelve or more [Polyplagia and Polyplecta, PI. 91, fig. 12). When these two genera are better known from further accurate observations, they may probably be divided into several different genera (as already proposed in my Prodromus, 1881), since not only the number, but also the central junction and the arrangement of the numerous radial spines in the few observed species seems to be very different. In some seven-radiate species {e.g., Polyplecta heptacantha) four larger spines seem to l)e true " cortinar spines," the three smaller secondary productions of the former. In the nine-radiate species the nine spines seem to be sometimes basal branches of three primary spines, at other times six secondary intercalated between the three primary (like EnneapJiormis, PL 57, fig. 9). In those multiradial Plectoidea, in which the number of spines amounts to ten or twelve or more, the laws of disposition are not yet recognised. Comparing these different productions of the skeleton in the numerous Plectoidea, we find expressed two remarkable and very different affinities. On the one hand many Plectoidea exhibit exactly the same peculiar forms, which are only found besides in the Beloidea (as many species of Triplagia, Plagiacantha, Tetraplagia, Plagonidium, Hexaplagia, and Plagonium). On the other hand many Plectoidea bear the same characteristic composition of the skeleton (or the " cortinar structure ") which is found in the Cortinida among the S t e p h o i d e a, and in numerous Spyroidea and Cyrtoidea, which aU agree in the possession of three divergent basal feet and a vertical apical horn. A most important argument for the close affinity of all these " cortinar Nassellaria " seems to be given by the fact that the sagittal ring, which in Cortina is combined with the quadriradial structure, exhibits in the Cyrtellaria the most different stages of development ; in one group it is complete, in the second incomplete, and in the third it has completely disappeared. The form of the radial spines composing the skeleton is usually three-sided prismatic, gradually tapering from the thicker central base towards the distal apex ; sometimes they are slender pp'amidal. More rarely the spines are cylindrical or slender conicaL In the majority of species the spines are straight, in the mLaority more or 904 THE YOYAGE OF H.M.S. CHALLENGER. less curved. lu very few species only are they quite simple, without branches. They are nearly always more or less branched, in many larger species very richly ramified. The modes of ramification are rather variable. In the majority of Plectoidea the spines are rather regularly verticillate, bearing an increasing number of verticUs, each of which is composed of three divergent branches. These arise from the three edges of the spine, and aU the branches of one edge are usually parallel, either perpendicular to the spine, or directed at an acute angle towards its apex. When the verticUs are numerous (five to ten or more), their size commonly tapers gradually towards the apex. Pinnate spines occur more rarely than verticillate ones ; in this ease the two paired lateral edges only of the prismatic spine bear opposite or alternate branches, whilst the odd middle edge bears no ramules. In some species the spines are singly or doubly forked. In many species (mainly those with cylindrical spines) the ramifica- tion of the spines is more or less irregular. "Whilst in all Plagonida the branches of the spines remain perfectly free, in all Plectanida, again, the meeting ends of the branches become united and grow together, and by this concrescence a loose network arises, like wickerwork, which partly encloses the central cajasule and the central parts of the spines, on which it rests. The meshes of this loose wickerwork are large, either quite irregular, of very difi"erent size and form, or more or less regular, with a certain form and arrangement of the meshes, efi"ected by the peculiar kind of ramification. Commonly the siliceous thr-eads of the arachnoidal wickerwork are very thin, often extremely dehcate, representing "pseudopodia metamorphosed into silex." Sometimes the wickerwork is spongy. Its surface is constantly rough and bristly, with free ends of the spine-branches, never covered with a regular lattice-plate, as in the Cyrtellaria (Spyroidea, Botryodea, and C y r 1 0 i d e a). The entire form of the central wickerwork is in the minority of Plectanida c[uite irregular and indefinite ; in the majority, however, a certain more or less regular entire form is recognisable, eff"ected by a certain, more or less regular origin and mode of the connection of the meeting branches. So in some species of Triplecta (PI. 91, fig. 7) the network represents a triangular plate, of Plectopliora and Plectaniscus a three-sided pyramid, of Tetraplecta (PI. 91, fig. 3) a tetrahedi-on, and in many other species a polyhedron of more or less regular form. Some species of Plectanida become very similar to certain species of Stephoidea, Spyroidea, and Cyrtoidea; so Plectaniscus and Periplecta approach to Cortina and Cortiniscus, Pteroscenium and Clathrocorys, &c. (compare Pis. 92, 93, 53, 64, &e.). They may represent a true phylogenetic connection between both groups. But in these cases also the distinction is determined by the fact that the true Plectoidea never possess a complete sagittal ring (like the Stephoidea) nor a regular lattice-shell (like the Spyroidea, Botryodea, and Cyrtoidea). REPORT ON THE RADIOLARIA. 905 Tlie Central Capsule of the Plectoidca constantly exhibits the peculiar characters of the Monopylea or Nassellaria. It is commonly ovate, more rarely ellipsoidal or even spherical, sometimes conical or lentelli^Jtical. The lower or basal pole of its vertical main axis constantly exhibits the characteristic " porochora " (or the area porosa) of the Monopylea, and upon this rests the peculiar " podoconus " (or the pseudopodial-cone) of this legion. On this porochora the central caj)sule is in immediate connection with the central point of the skeleton, or the horizontal common central rod, from which the radial spines arise. The endoplasm, or the protoplasm of the central capsule (besides the podoconus), contains commonly one large alveole or several small vacuoles, and often pigment-granules. The nucleus is large, spherical or ovate, and exhibits the same character as in all the other Monopylea ; it encloses usually a single nucleolus. The position of the central capsule and its topographical relation to the skeleton oflFers in the different Plectoidea some important and as yet unsolved problems, which can be answered only by fresh and accurate observations on living specimens. In Triplagia and Triplecta, where the triangular skeleton lies in a horizontal plane, the vertical main axis of the central capsule is perpendicular to the central point of that supporting triangle. In Plagiacantha and Plectophora, where the three radial spines correspond to the edges of a flat pyramid, the capsule is enclosed in the pyramidal space of the latter, its basal pole touching the apex ; therefore in the normal position of the body the three divergent rays are directed upwards. In Tetixqjlagia and Tetraplecta probably the same position is retained, and therefore the fourth free spine, here developed, is probaljly directed vertically downwards. In Plagoniscus and Plectaniscus, however, and, moreover, in the closely aUied Plagiocarpa and the corres- ponding Periplecta (PI. 91, figs. 5, 10) the position of the central capsule, relative to the skeleton, seems to be inverse, and to agree with that of the Stephoidea {Cortina, Cortiniscus, &c.) and the Cyrtoidea (Pterosceiiium, Clathrocorys, &c.); the three divergent spines are here directed downwards (as basal feet), whilst the opposite fourth spine is vertically directed upwards (as an apical horn); the capsule rests here upon the tripod, which lies below it, and is inclined with its dorsal face to the apical spine. In the majority of the other Plectoidea the position of the central capsule and its relation to the skeleton are not yet sufficiently observed, and require further accurate researches. Its position seems to be very different in the several genera. The capsule is never perforated by parts of the skeleton; this latter is constantly extra-capsular. The physiological value of the skeleton, with regard to the central capsule, is different in the Plagonida and Plectanida; in the former it supports, in the latter it encloses the capsule like a shell. In the NasseUida, where no skeleton is developed, the central capsule is quite free and naked, enveloped only by the calymma. (ZOOL. CHALL. EXP. — PAET XL. 1885.) El 114 906 THE VOYAGE OF H.M.S. CHALLENGER. The calymma or the extracapsular jeEy-veil in all P 1 e c t o i d e a is voluminous, and encloses not only the central capsule completely, but also the skeleton wholly or partially. Its form is of the greatest value for the development and configuration of the skeleton. Sometimes the calymma is alveolate and foamy, as in Nassella and the common Thalassicolla, In several other Plectoidea the calymma seems to include numerous small vacuoles, sometimes also pigment-granules. Xanthellae are commonly scattered in it in great numbers. The pseudopodia, arising in a large bunch from the porochora of the capsule, and running along the branches of the radial spines, seem to be always numerous, richly branched, and with a strong tendency to form anastomoses. The peculiar form of their network is often exactly preserved in the con- formation of the skeleton, produced by them. The peculiarities of this network require further accurate observations, as does the whole organisation of the Plectoidea. Synopsis of the Families of Plectoidea. L Skeleton (originally tripodal) composed of radial spines united in a common centre and supporting the central capsule, without wicker-work, . .1. Plagonida. II. Skeleton (originally tripodal) wattled, with irregular wicker-work, composed of the united branches of radial spines and enveloping the central capsule, . . 2. Plectanida. Family XLVI. Plagonida, Haeckel. Plagonida, Haeckel, 1881, Prodromus, p. 423. Plagiaoanthida {sensu stridlori), Eichard Hertwig, 1879, Organismus d. Eadiol., p. 72. Definition. — P lectoidea with a spiny skeleton, composed of radial spines, which arise from a common central point or central rod, and support the free central capsule. The family Plagonida comprises those Nassellaria in which the skeleton is only composed of united radial spines, arising from a common centre, without any connec- tion of meeting branches of the spines ; the rudimentary skeleton exhibits therefore neither a loose wickerwork (as in the closely allied Plectanida), nor a ring (as in the Stephoidea), nor a complete lattice-shell (as in the Cyrtellaria, the Spyroidea, Botryodea, and C y r t o i d e a). The central capsule, which possesses all the characters of the Monopylea, is therefore free, not enclosed, and only on one side supported or partly protected by the radial spines or their branches. Two species only of Plagonida have been hitherto known. The first form described is the Plagiacantha arachnoides, discovered thii-ty years ago (1855) by Claparfede on the western shore of Norway. Another species of the same genus, from the Mediterranean, was very accurately described by Richard Hertwig in 1879 in his Organismus der REPORT ON THE RADIOLARIA. 907 Radiolarien (Plagiacantha ahietina). Upon these two species the latter founded his family Plagiacauthida, a term which was afterwards employed by Biitschli and others, for the whole group of P 1 e c t o i d e a. Many new forms are contained in the collec- tion of the Challenger, so that we may describe here nine genera and thirty-four species. The family Plagonida may be divided into four different subfamilies, according to the numbers of the radial spines which compose the skeleton : Triplagida with three, Tetraplagida with four, Hexaplagida with six, and Polyplagida with numerous (seven to nine or more) radial spines. These are united commonly in one common central point, upon which rests the basal pole of the central capsule, with the porochora. More rarely (in the genera Plagonidium, Plagiocarpa, and Plagonium) the spines arise in two opposite groups (each with two or three spines) from the two poles of a common central rod; in this case the basal pole of the central capsule with the porochora rests upon the horizontal common rod, which corresponds probably to the basal part of the sagittal ring of the Stephoidea and C y r t e 1 1 a r i a. The different forms which the skeleton of the Plagonida assumes in the different genera of this family, and the important relations which these exhibit on the one hand to the spicula of the Beloidea, and on the other hand to the shell of some Stephoidea [Cortina, Cortiniscus, &c.) and Cyrtoidea (Pteroscenium, Clathrocorys, &c.), have Ijeen already pointed out in the preceding description of the suborder Plectoidea. There it is also demonstrated, that all these different forms may be derived from the simplest tru'adial forms, Triplagia and Plagiacantha (compare above, pp. 900—904). Whilst the genera of the Plagonida are characterised by the number of the radial spines and the peculiar mode of junction in a common central point or at the two poles of a common central rod, the different species of this family may be defined by the peculiar form of the spines and their branches. These morphological characters have also been already described above. We repeat here only that the radial spines in the majority of species are three-sided prismatic and verticillate, each verticil commonly with three branches. The distal ends of these branches remain constantly free, and are never united, as is always the case in the following family. The Central Capsule of the Plagonida exhibits the general characters of all MoNOPYLEA (compare above, p. 890). It is commonly ovate or ellijjsoidal, with vertical main axis ; on the lower pole of the latter is the porochora (or the " area porosa," from which all pseudopodia radiate). This is in immediate connection with the central point or central rod of the skeleton, in which' its radial spines are united. The topographical relation of the supporting skeleton to the central capsule seems to exhibit in the different genera of the Plagonida remarkable differences, as already demonstrated above (p. 905). 908 THE VOYAGE OF H.M.S. CHALLENGER. I. Subfamily Triplagicla. Three radial sijines. IL Subfamily Tetraplagida. Four radial spines. III. Subfamily Hexaplagida. Six radial spines. IV. Subfamily Polyplagida. Numerous radial spines. Synopsis of the Genera of Plagonida. Three spines lying in one horizontal plane, . Three spines corresponding to the edges of a flat pyramid, All four spines equal, Four spines arising from one common central point. Four spines arising in two pairs from the poles of a common central rod. One apical spine opposed to three basal spines, All four spines equal, One apical spine opposed to tlu'ee basal spines. (" Six spines arising from one common central point, J Six spines arising in two opposite groups from the poles of a common central rod, ..... Numerous (seven to nine or more) radial spines arising from a common centre (either a central point or a branched rod), ....... 384. Triplagia. 385. Plagiacantha. 386. Tetraplagia. 387. Plagoniscus. 388. Plagonidium. 389. Plagiocarpa. 390. Flexaplagia. 391. Plagonium. 392. Polyplagia, Subfamily 1. Tkiplagida, Haeckel, 1881, Prodromus, p. 423. Definition. — P 1 a g o n i cl a with three radial spines. Genus 384. Triplagia,^ Haeckel, 1881, Prodi-omus, p. 423. Definition. — P lagonida with three radial spines, arising from one common central point and lying in one horizontal plane. The genus Triplagia and the following closely allied Plagiacantha may be regarded as the simplest and most primitive forms of the Plectoidea, perhaps as the common ancestral stock of this suborder. The skeleton is composed of three simple or branched radial spines, arising from one common central point. These three spines in Triplagia lie in one and the same plane, whilst in Plagiacantha they lie in different planes. Therefore the former exhibits the simplest type of the triradial structure, common to the majority of Nassellaria. ' JVipZa(/ia= Triangular or three-radial ; Tg/xAay/of. REPORT ON THE RADIOLARIA. 909 1. Triplagia primordialis, n. sp. (PI. 91, fig. 2). Spines straight, of equal size and similar form, equidistant, three-sided prismatic, each with two pairs of opposite lateral branches, which are correspondingly parallel to the two other spines ; the proximal branches twice as long as the distal branches. Bimensixms. — Length of each spine 0"2, of the basal branches 0"07. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 2. Triplagia triradialis, n. sp. Spines straight, of equal size and similar form, equidistant, three-sided prismatic, regularly pin- nate, with six pairs of opposite pinnulce, tapering gradually towards the distal ends; the basal pinnulge are again branched, with straight ramules. Dimensions. — Length of each spine 0"27, of the basal branches 0'08. Habitat. — Xorth Pacific, Station 256, surface. 3. Tripilagia horizontalis, n. sp. Spines curved, cylindrical, irregularly branched, with three primary and nine to twelve secondary branches, which are also slightly curved. The angles between the bases of the three spines are equal, but the size and form of the branches different. Dimensions. — Length of the three spines 015 to 0'25, of the basal branches 0'05 to 0'08. Habitat. — West Tropical Pacific, Station 225, depth 4475 fathoms. Genus 385. Plagiacantha} Claparede, 1856, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, November 13. Definition. — P 1 a g o u i d a with three radial spines, arising from one common central point and corresponding to the edges of a three-sided pyramid. The genus Plagiacantha agrees with the preceding Triplagia in the simple structure of the triradial skeleton, composed of three diverging radial spines, which are united in a common centre at the oral pole of the central capsule. But whilst the three radial rods of Triplagia lie in one horizontal plane, here they lie in different planes and correspond to the tliree edges of a flat pyramid. Plagiacantha arachnoides, described in 1856 by Claparede, was the earliest known form of aU Plectoidea. ' PlagiacantJia ^Heiving spines on the sides ; wTiay/of, SicauOa- 910 THE VOYAGE OF H.M.S. CHALLENGER. 1. Plagiacantha arachnoides, Claparede. Plagiacantha arachnoides, Claparfede, 1856, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, November 13. Plagiacantha arachnoides, Claparede, 1858, Etudes sur les Infusoires et les Rhizopodes, p. 462 (pL xxii. fig. 8). Acanthomctra arachnoides, Claparfede, 1855, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 675. Spines straight, cylindrical, divided into three divergent straight branches of equal size ; each branch two to three times as long as the simple thicker basal part. Dimensions.- — Length of the spines 012 to 0-2, of the branches O'OS to 014. Habitat. — North Atlantic, coast of Norway, Claparede, surface. 2. Plagiacantha furcata, n. sp. Spines straight, cylindrical, divided into two divergent straight branches of equal size, of about the same length as the simple basal part. The spines and their branches are smooth. Dimensions. — Length of the spines 0'24, of their fork-branches 012. Habitat. — North Pacific, Station 254, surface. 3. Plagiacantha dodecantha, u. sp. Spines straight, three-sided prismatic, in the middle with one verticil composed of three divergent straight branches of equal size, of about the same length as the simple basal part. The edges of the spines and their branches are thorny. Dimensions. — Length of the spines 0'24, of the branches 01. Habitat. — Central Pacific, Station 274, surface. 4. Plagiacantha ahietina, Eichard Hertw^ig. Plagiacantha ahietina, Eichard Hertwig, 1879, Organismus d. Radiol., p. 72, Taf. vii. figs. 6-6i. Spines straight, three-sided prismatic, with three verticils of three divergent straight lateral branches, decreasing in size towards the distal end ; the branches of the first verticil about twice as long as those of the second, and four times as long as those of the third verticil. All nine branches of each spine simple, straight, three-sided pyramidal. Dimensions. — Length of the spines 0'2 to 0'3, of the basal branches 0'06 to 0'08. Habitat. — Mediterranean, Messina (E. Hertwig), surface. 5. Plagiacantha verticillata, n. sp. Spines curved, three-sided prismatic, with six to nine verticils of three chvergent branches, decreasing in size towards the distal end ; the branches of the first verticil about twice as long as those of the fourth verticil. All branches simple, slightly curved, bristle-shaped. Dimensions. — Length of the spines 0-27, of the basal branches 012. Habitat. — South Pacific, Station 296, surface. REPORT ON THE RADIOLARIA. 911 6. Plagiacantha elatine, n. sp. Spines straight, three-sided prismatic, with prominent wing-like edges and ten to twelve verticils of three divergent branches, decreasing in size towards the distal end ; the branches of the three or four basal verticils are again ramified and much larger than the simple branches of the distal verticUs. Dimensimis. — Length of the spines 0'3G, of the basal branches 0'14. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. Subfamily 2. Tetraplagida, Haeckel, 1881, Prodromus, p. 424. Definition. — P lagonida with four radial spines. Genus 386. Tetraplagia} Haeckel, 1881, Prodromus, p. 424. Definition. — P lagonida with four equal radial spines, arising from one common central point, and corresponding to the four axes of a tetrahedron. The genus Tetraplagia is one of the most important P 1 e c t o i d e a, and possibly the common ancestral form of many Nassellaria (compare above, p. 901). The skeleton is composed of four radial rods, diverging from one common centre in different directions, and corresponding to the four axes, which extend from the central point of a tetrahedron to the central points of its four faces. The whole skeleton of Tetraplagia exhibits therefore the same form, which is observed in the single quadriradiate spicula of some B el 0 i d e a (in some species of Lamiwxantliium, SphcBrozoum, &c.). 1. Tetraplagia geometrica, n. sp. Spines straight, cylindrical, perfectly equal, corresponding in regular disposition exactly to the four geometrical axes of a regular tetrahedron ; in the middle arise from each spine two opposite equal lateral branches of half the length of the spiae. Bimensions. — Length of the spines 012, of the branches 0'06. Halitat. — Central Pacific, Station 266, surface. 2. Tetrapiagia phcBna^xoraa, n. sp. (PI. 91, fig. 3). Spines straight or slightly curved, three-sided prismatic, with irregular short branches arising from the three edges ; the branches are thorny, tapering towards the apex. Dimensions. — Length of the spines 015, of the basal branches 0'03. Habitat. — Tropical Atlantic, Station 332, surface. 1 Tetraplagia = Four-sided ; nrQcc'xXxyios. 912 THE VOYAGE OF H.M.S. CHALLENGER. 3. Tetraplagia ahietina, Haeckel. Plagiacantha ahietina, var. quadrispina, Richard Hertwig, 1879, Organismus d. Radiol., p. 73. Spines straight, three-sided prismatic, verticillate, with six to eight verticils of three simple straight branches ; the branches of each edge are parallel, tapering towards the distal end. E. Hertwig regards this species only as a four-spined variety of his three-spined Plagiacantha ahietina ; but a specimen, observed by me in Corfn, exhibited all the characters of Tetraplagia. Dimensions. — Length of the spines 0'2, of the basal branches 0'07. Hahitat. — Mediterranean (Messina, Corfu), surface. Genus 387. Plagoniscus} n. gen. Definition. — Plagonida vrith four unequal radial spines, arising from one common central point ; one vertical or apical spine opposed to three divergent or basal spines. The genus Plagordscus agrees with the preceding Teti-aplagia (its probable ancestral form) in the possession of four radial spines, diverging from one common central point. But whilst in this latter all four spines are equal, corresponding exactly to the four axes of a tetrahedron, here in Plagiocarpa an important difierence exists between one vertical or apical spine and three other divergent basal spines ; these latter corresponding probably to the three "feet," the former to the single "apical horn" of the majority of Nassellaria. Perhaps we find here one of the oldest and simplest types of their " triradial or cortinar structure " (compare above, p. 902). 1. Plagoniscus tripodlscus, n. sp. (PL 91, fig. 4). Spines three-sided prismatic, thorny. Apical spine nearly straight, verticillate, with four to five verticils of three thorny branches, tapering towards the apex. Tliree basal spines somewhat shorter,, curved, with three thorny edges. Dimensio-ns. — Length of the apical spine 0"2, of the basal spines 015. Habitat. — Central Pacific, Station 263, surface. 2. Plagoniscus euscenium, n. sp. Spines three-sided prismatic, thorny, with dentate edges, and three to six verticils of three short branches. Apical spine straight, with six verticils, nearly twice as long as the three curved basal spines, each of which bears three verticils ; the basal verticils larger and ramified. Resembles somewhat Euscenium eucolpium, PI. 53, fig. 12, but has no latticed shell. Dimensions. — Length of the apical spine 0'3, of the basal spines 0"16. Habitat. — ^North Pacific, Station 247, surface. 1 Plagoniscus— ^idji — windlass ; xXayo;, suVxof. REPORT ON THE RADIOLARIA, 913 3. Plagoniscus cortinaris, u. sp. Spines three-sided prismatic, straight, verticillate. Apical spine with twelve verticils, one and a half times as long as the three basal spines, each of which bears eight verticils of three branches. The branches are also prismatic, straight, on each edge parallel, tapering towards the apex, in the three basal spines forked, in the apical spine more branched. Similar to the cortinar skeleton of Clathrocorys (PL 64, figs. 8-10). Dimensions. — Length of the apical spine 0'24, of the basal spines 0'16. Habitat. — South Atlantic, Station 338, surface. 4. Plagoniscus nassellaris, n. sp. Spines cylindrical, curved, irregularly branched. Apical spine half as long as, and less branched than the three basal spines, which are sigmoidal, nearly horizontally expanded in the proximal half, descending in the distal half. Dimensions. — Length of the apical spine 01, of the three basal spines 01 8. Sabitat. — West Tropical Pacific, Station 224, surface. Genus 388. Plagonidium,^ Haeckel, 1881, Prodromus, p. 424. Definition. — P lagonida with four equal radial spines, arising in pairs from the two poles of a common central rod. The genus Plagonidium and the following Plagiocarpa possess four radial spines, like the two preceding genera. But whilst the four rods in these latter arise from a common centre, here they arise in two pairs from the two poles of a common middle rod ; they have therefore exactly the same form which we find in the single spicula of some Beloidea (e.g., Tlialassoxanthium furcatum, SphcBvozoum furcatum, &c.). Probably the middle rod is horizontal and serves as supporting base for the central capsule, whilst two opposite spines are directed upwards, two other downwards. 1. Plagonidium higeminum, n. sp. Spines straight, three-sided prismatic, four to six times as long as the common central rod, pinnate, with four to five pairs of opposite pinnulse, the distal of which are simple, the proximal again branched. Dimensions. — Length of the spines 0 16, of the middle rod 0'032. Habitat. — Indian Ocean, Sunda Strait (Eabbe), surface. ' PZa(7o?iirfium= Small side-article ; irT^xyauliiop. (ZOOL. CHALL. EXP. PART XL. 1886.) El 115 914 THE VOYAGE OF H.M.S. CHALLENGEE. 2. Plagonidium quadrigemimim, n. sp. Spines cylindrical, curved, eight to ten times as long as the conunon central rod, in the distal half forked ; the fork-branches curved, somewhat longer than the basal part. Dimensioiis. — Length of the spines 018, of the middle rod 0-02. Habitat. — Antarctic Ocean, Kerguelen Island, Station 159, surface. Genus 389. Plagiocarpa,'^ Haeckel, 1881, Prodromus, p. 424. Definition. — P 1 a g o ii i d a with four unequal radial spines, arising in pairs from the two poles of a common central rod ; one ascending apical spine opposed to tkree descending basal spines. The genus Plagiocarpa agrees with the preceding Plagonidium in the possession of a common horizontal middle rod, the two poles of which bear two pairs of divergent spines; but whilst in the preceding all four spines are equal, here they are differentiated in the same manner as in Plagoniscus, which differs only in the absence of the middle rod. The two observed and closely allied species of this genus are of peculiar interest, since they belong possibly to the common ancestral forms of the Nassellaria ; the basal middle rod corresponds perhaps to the basal part of a sagittal ring, the apical spine to its dorsal part, the three other spines to the basal feet (compare above, p. 902). 1. Plagiocarpa procortina, n. sp. (PI. 91, fig. 5). Spines cyHndrical, curved, thorny, three to four times as long as the common middle rod. Apical spine and the meeting caudal spine (or the posterior basal spine) somewhat larger and with more numerous thorns than the two paired pectoral (or anterior) spines. From the common base of the latter arises an anterior prolongation of the horizontal middle rod, which in the sagittal plane is curved upwards and corresponds to the sternal foot of many Cyrtellaria. An ascending branch of this spine is opposed to a descending branch of the apical spine, both together forming an incomplete sagittal ring. Dimensions. — Length of the two larger spines 015, of the two smaller 0'12. Habitat. — Mediterranean (Portofino near Genoa), surface. 2. Plagiocarpa procyrtella, n. sp. Spines of form and arrangement similar to those of the preceding species, but longer and more branched, six to eight times as long as the shorter common middle rod. The two characteristic ' Ptojiiocarpa = Having its fruit (the central capsule) on the side ; u-Xay/oxafj^oj. REPORT ON THE RADIOLARIA. 915 opposed branches (the ascending branch of the basal rod and the descending branch of the apical spine), which in the preceding species nearly compose a sagittal ring, are here absent. Dimensions. — Length of the two larger 0-27, of the two smaller 0'21. Habitat. — North Atlantic, Iceland (Steenstrup), surface. Subfamily 3. Hexaplagida, Haeckel. Definition. — P lagonida with six radial spines. Genus 390. Hexaplagia,^ Haeckel, 1881, Prodromus, p. 424. Definition. — P lagonida with six radial spines, arising from one common central point. The genus Hexajilagia differs fi-om the preceding genera of Plagonida in the possession of six radial spines, diverging from one common central point. Commonly, these six spines seem to lie opposite in pairs in three different meridian planes, and in this case Hexaplagia may be regarded as a Plagiacantha, the three radial spines of which are prolonged over the basal pole of the central capsule. But in other species the six spines seem to lie in different planes. Further observations are required. 1. Hexaplagia arctica, n. sp. Spines opposite in pairs in three diameters, crossed in the common centre, straight, three-sided prismatic, with dentate edges. The three pairs are equal, but the upper spine of each pair only half as long as the lower spine. DiviensioTis. — Length of the upper spine 013, of the lower 0'27. Habitat. — Arctic Ocean (Greenland), in the stomach of a Medusa (Olrik). 2. Hexaplagia antarctica, n. sp. Spines opposite in pairs in three diameters, crossed in the common centre, slightly curved, three- sided prismatic, with verticillate branches ; the three pairs are equal, but the lower spine of each pair bears three to four verticils, each of three branches, and is two to three times as long as the upper spine, which bears two verticils only. Dimensions. — Length of the upper spine 012, of the lower 0-3. Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms. 1 flexopZo^m = Six-sided ; e|«n->i«7(o;. 916 THE VOYAGE OF H.M.S. CHALLENGER. 3. Hexaiolagia collaris, n. sp. Spines in opposite pairs in three diameters, crossed in the common centre, straight, cylindrical, pinnate, with three to fonr pairs of opposite lateral branches or regular pinnulse. All six spines are equidistant, of equal size and similar form, and lie with their branches nearly in one horizontal plane. Therefore they are similar to the six radial rods in the coUar septum of many Spyroidea and Cyrtoidea {e.g., Calpophcena, PI. 53, fig. 18). Dimensions. — Length of aU six spines 018, of their basal pinnule 0-04. Habitat. — East of New Zealand, Station 169, surface. 4. Hexaplagia australis, n. sp. Spines unequal, at unequal intervals, not opposite in pairs, cylindrical, irregularly branched and curved. In this species a definite arrangement of the six different spines could not be detected. Dimensions. — Length of the spines 0-2 to O'S, of their largest branches 01. Habitat. — South of Australia, Station 160, surface. Genus 391. Plagonium,^ Haeckel, 1881, Prodromus, p. 423, Definition. — P lagonida with six radial spines, arising in two opposite divergent groups from the two poles of a common central rod. The genus Plagonimn differs from the preceding closely allied Hexaplagia in the remarkable peculiarity, that the six radial spines do not arise from one common central point, but from the two poles of a common horizontal middle rod ; three divergent spines on each pole. The skeleton of Plagonium exhibits therefore the same remark- able form which is found in the isolated spicula of numerous Beloidea (e.g., Lampoxantliium lyunctatum, Spharozoum p>unctatum), and bears the same relation to Hexaplagia that Plagonidium does to Tetraplagia. 1. Plagonium sphcerozoum, n. sp. (Pi. 91, fig. 6). Spines straight and stout, three-sided prismatic, about twice as long as the common middle rod, irregularly branched or nearly vertieiUate, with short thorny branches. Similar to the single spicula of some species of Sphcerozoum, and Lampoxanthium. Dimensions. — Length of the spines 012, of the middle rod 0"06. Habitat. — Equatorial Atlantic, Station 347, surface. * Pfo^oniiim = Side-article ; wAtiyof, umm. EEPOET ON THE RADIOLARIA. 917 2. PJagonium lampoxanthium, n. sp. Spines irregularly curved, slender, cylindrical, six to eight times as long as the common middle rod, in the proximal half smooth, in the distal half covered with short thorns. (Similar to an isolated spiculum of Zampoxanfhium punctatum or of SjjJicBrozoum variabile, PI. 4, fig- 5.) Dimensions. — Length of the spines 0'18, of the middle rod 0-03. Habitat. — North Pacific, Station 240, surface. 3. PJagonium arhorescens, n. sp. Spines irregularly curved and branched, slender, cylindrical, thorny, twelve to sixteen times as long as the middle rod ; the branches are large, arborescent, their ramules again ramified and very thorny. Dimensions. — Length of the spines 02 to 0-25, of the middle rod 0'02. Habitat. — Indian Ocean, Madagascar (Rabbe), surface. 4. PJagonium trigeminum, n. sp. Spines straight, slender, cylindrical, four to six times as long as the middle rod, in the basal half smooth, in the distal half arborescent, with three to four irregular verticils of ramified branches. (Similar to a single spiculum of S2)liccrozoum vcrticillatum, PI. 4, fig. 7.) Dimensions. — Length of the spines 015 to 0'2, of the middle rod 0'05. HaMtat. — Central Pacific, Station 265, depth 2900 fathoms. 5. PJagonium distriactis, n. sp. Spines straight and stout, three-sided prismatic, smooth, ten to twelve times as long as the middle rod ; each on the distal end cleft into three divergent straight branches; which are again trichotomous. Dimensions. — Length of the spines 015 to 018, of the middle rod 0-015. Habitat. — South Pacific, Station 288, surface. Subfamily 4. Polyplagida, Haeekel, 1881, Prodromiis, p. 424. Definition. — P 1 a g 0 n i d a with numerous (seven to nine or more) radial spines. Genus 392. PoJypJagia,'^ n. gen. Definition. — P 1 a g o n i d a with numerous (seven to nine or more) radial spines, arising from a common centre and lying in different planes. 1 Poij|pia^ta= Manifold; xoXu^rXay/of. 918 THE VOYAGE OF H.M.S. CHALLENGER. The genus Polyplagia alone represents the small subfamily of Polyplagicia, dis- tinguished from the other Plagonida by the multiplication of the radial spines, the number of which amounts to seven to nine or more. This increased number is commonly the result of an intercalation of new spines between the three or four primary spines ; it is sometimes also effected by stronger development of branches of the latter, which become independent. The following five species of this genus are very different, requii-e further investigation, and perhaps represent different genera: — 1. Polyplagia septenaria, n. sp. Seven radial spines, straight, three-sided prismatic, verticillate, of different sizes ; four larger spines correspond to the four axes of a tetrahedron (running from the centre to the four corners), each with five to six verticils of three simple slender branches ; one of these four main spines seems to be the apical, the three others the basal spines of Plagiocarpa ; in the three meridian planes between the latter and the former lie the three smaller spines, diverging upwards, each with two to three verticils. (Similar to Polyplecta heptacantha, PI. 91, fig. 12, but without connection between the branches.) Dimensions. — Length of the four major spines 0'26, of the three minor Oil. Habitat — Central Pacific, Station 274, surface. 2. Polyjylagia octonaria, n. sp. Eight radial spines, straight, three-sided prismatic, of equal size, arising in two opposite groups from the two poles of a short common middle rod (as in Sphccrozouni arborcsccns, PI. 4, fig. 8, and in other B e 1 o i d e a). The four spines of each group are divergent, six to eight times as long as the middle rod, each spine armed with three to four verticils of thorny branches. Dimensions. — Length of the spines i0"15, of the middle rod 0022. Habitat. — Indian Ocean, Cocos Islands (Eabbe), surface. 3. Polyplagia novenaria, n. sp. Nine rachal spines of equal size, straight, cylindrical, lying nearly in a horizontal plane, or forming a very flat pyramid. Near the common central point every three spmes arise from a short common rod, so that the centre of the skeleton is triradial. Each spine bears towards the apex two divergent straight lateral branches. This species may have been derived from Flagiacantha arach- noides by shortening and reduction of the basal parts of the three original branched primary spines. Dimcnsiotis. — Length of the nine spines 0"24, of the three basal rods 0'02. Habitat. — North Atlantic, Eajroe Channel (Gulf Stream), John Murray, surface. 4. Polyp)lagia duodenaria, n. sp. Twelve radial spines of equal size, arising from a common central point, and diverging in different directions. The twelve spines are very large, opposite in six pairs, cylindrical, longitudinally EEPOET ON THE RADIOLARIA. 919 striped (the expression of concentric lamelltB), and with spinxilate surface, covered with innumerable small thorns. The basal quarter of each spine is straight and simple, the second quarter twice forked, and these four fork-branches are again in the outer half of the spine richly forked or ramified, with diverging, slightly curved thin branches ; each of the twelve spines with about sixty to eighty terminal branches, the ends of which seem to fall into a spherical face. The position of this remarkable species in this family is doubtfuL Dbrmiisions. — Length of the spines 012 to 016, of the simple basal part 0*04. Habitat. — South Pacific (off Juan Fernandez), Station 299, surface. 5. Polyplagia viminaria,. n. sp. Numerous (sixteen to twenty or more) radial spines of about equal size, arising from a common central point and diverging in different directions, richly and more or less irregularly branched. The ends of the numerous small branches seem to fall into a spherical face. The large spines of this species have the same form and structure as in the preceding, nearly allied species, but are more numerous and more irregularly branched and disposed. Dimensio7is. — Length of the spines 0'2 to 0'25, of the simple basal part 0'05. HahUat. — North Pacific, Station 241, surface. Family XLVII. Plectanida, HaeckeL Pledaiuda, Haeokel, 1881, Prodromus, p. 424. Definition. — P lectoidea with a wattled skeleton, composed of tlie meeting and' united branclies of radial spines, which arise from a common central point or central rod, and protect the partly enclosed central capsule. The family Plectanida comprises those Nassellaria in which the skeleton is composed of radial spines, arising from a common centre, and of a loose wickerwork, produced by concrescence of the meeting branches of those .spines. This rudimentary wattled skeleton is either quite irregular or only slightly regular, but it never assumes the form of a complete lattice-shell, as in the Cyrtellaria (the Spyroidea, B 0 t r y o d e a, and C y r t o i d e a), nor does it exhibit a ring (as in the S t e p h o i d e a). The central capsule is partly or wholly protected, and often entirely enclosed by the wattled skeleton. Three species only of Plectanida have been hitherto known. The first described form is Plectophora arachnoides, which its discoverer Claparede observed in a living state in 1855 on the western coast of Norway, and considered as a mere variety of his Plagia- cantha arachnoides. Two other species were afterwards observed in the Mediterranean, Polyplecta dumetum, 1856, by Johannes Miiller (united by him with Aca7ithodesmia) and Polyplecta polyhrocha by myself in 1864. Many new forms are found in the 920 THE VOYAGE OF H.M.S. CHALLENGER. collection of the Challenger, so that we may here distinguish eight genera and twenty- seven species. The family Plectanida may be divided into four different subfamilies, according to the number of the radial spines which compose the skeleton. These four subfamilies, as also the genera contained in them, correspond exactly to the four subfamilies of Plagonida, from which they have originated : Triplectida with three, Tetraplectida with four, Hexaplectida with six, and Polyplectida with numerous (seven to nine or more) radial spines. These spines are usually united (as in the corresponding ancestral Plagonida) in one common central point, upon which rests the basal pole of the central capsule, with the porochora. More rarely (in the genera Periplecta and Plectanium) the spines arise in two opposite groups (each of two or three spines) from the two poles of a common horizontal central rod, which supports the overlying porochora of the central capsule. The ditiereut genera of Plectonida, which are enumerated in the following synopsis, correspond so exactly to the different genera of Plagonida described above, that probably each of the former has arisen from a corresponding genus of the latter. The only difference between the two is, that in all Plagonida the branches and ramules of the radial spines end freely, without growing together, whilst in all Plectanida the meeting ends of the neighbouring spines grow together and so produce a loose and irregular wickerwork. Therefore the latter constantly possess meshes, which are missing in the former. As soon as any form of Plagonida begins to produce meshes by concrescence of meeting branches of the spines, it passes over into a corresponding form of Plectanida. The loose mckerwork or wattlework so produced is sometimes very irregular, at other times more or less regiUar ; but it never assumes the regular form of a complete lattice -shell, as in the C y r t e 1 1 a r i a (S p y r o i d e a, B o t r y o d e a, and C y r t o i d e a). The general differences which this wickerwork exhibits in the different genera of Plectanida have been already described above (compare pp. 900—904). The Central Capsule of the Plectanida agrees perfectly with that of the ancestral Plagonida, as well in general form and structure as in the peculiar topographical relation to the radial spines (compare above, p. 905). A slight difference between the two families is effected by the higher development of the skeleton in the Plectanida. Since the branches of the radial sj)ines in this family become united and form a loose wicker- work, the central capsule becomes more or less enclosed by the latter, and more perfectly protected, than in the Plagonida, where the branches remain free. In this respect the Plectanida approach more nearly to the Cyrtoidea with which they are connected by such transitional forms as Plectaniscus and Periplecta on the one hand, Cladoscenium and Pterosceniiim on the other. REPORT ON THE RADIOLARIA. 921 I. Subfamily TriplectiJa. Three radial spiues. II. Subfamily Tetraplectida. Four radial spines. III. Subfamily Hexaplectida. Six radial spines. IV. Subfamily Polyplectida. Numerous radial spines. Synojms of the Genera of Plectanida. Three spines lying in one horizontal plane, . Three spines corresponding to the edges of a flat pyramid, ' All four spines equal, Four spines arising from one common central point. One apical spine opposed to three basal spines. Four spines arising in two pairs from the poles of a common central rod; one apical spine different from three basal spines, ....... Six spines arising from one common central point, . Six spines arising in two opposite groups from the poles of a common central rod, ..... ( Numerous (seven to nine or more) radial spines arising from J a common centre (either a central point or a branched ( rod) 393. Triplecia. 394. Plectophora. 395. Tetraplecta. 396. Pledanisciis. 397. Peripleda. 398. Hexaplecta. 399. Pledanium. 400. Polypleda. Subfamily 1. Triplectida, Haeckel, 1881, Prodromus, p. 424. Definition. — P lectanida with three radial spines. Genus 393. Triplecta,'^ Haeckel, 1881, Prodromus, p. 424. Definition. — P lectanida with three radial spines, arising from one common central point and lying in one horizontal plane. The genus Triplecta is the simplest and most primitive of the Plectanida, and may therefore be regarded as the prototype of this family. The skeleton represents a triangular lattice-plate with three radial beams. On the central union of the latter rests the oral pole of the central capsule. Since the axis of the latter is vertical, the lattice-plate must be horizontal, serving for the expansion of the pseudopodia. Triplecta has arisen from Triplagia by union of the branches of its three radial spines. In the simplest case only three large meshes are formed, corresponding prob- ably to the three cortinar meshes in the collar septum of many Cyrtellaria. 1. Triplecta triangulum, n. sp. Spines straight, equal, smooth, cylindrical, each in the basal half with one pair of divergent straight lateral branches. The opposed branches of every two neighbouring spines are united by a 1 JVtpfecte = Himting net with three beams ; tjij, otTvsxt^ (ZOOL. CHALL. EXP. — PAET XL. 1886.) Er 116 922 THE VOYAGE OF H.M.S. CHALLENGER. thin convex bow. In this way arises a very simple, equilateral triangular skeleton, with three equal large meshes. Dimensions. — Length of the spines 0-14, sides of the triangle 0'16. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 2. Triplecta triactis, n. sp. (PI. 91, fig. 7). Spines straight, equal, three-sided prismatic, pinnate, each with three to four pairs of opposite slender pinnulte or lateral branches ; the pinnulffi of each spine are correspondingly parallel to the main rods of the other two spines. Ail pinnulte branched and connected by a few slender bows, marking the sides of a regular triangle. Bimensions. — Length of the spines 0'15, sides of the triangle 0"l7. Habitat.— Qenti&\ Pacific, Station 272, depth 2600 fathoms. Genus 394. Plectophora,^ Haeckel, 1881, Proclromus, p. 424. Definition. — P lectanida with three radial spines, arising from one common central point and corresponding to the edges of a three-sided pyramid. The genus Plectophora has been derived from Plagiacantha by union of the meeting neighbouring branches of the three radial spines, and exhibits therefore to it the same relation that Triplecta bears to Triplagia. The loose framework so produced corre- sponds to the three sides of a flat pyramid and supports the central capsule. 1. Plectophora triomma, n. sp. Spines equal, straight, three-sided prismatic, thorny, connected by three convex bows, the meeting branches of lateral spines arising in one pair from the middle part of each spine. There- fore the skeleton exhibits three large ovate meshes only. Bimensions. — Length of the spines 0'12, of the meshes 0'08. Habitat. — North Pacific, Station 238, surface. 2. Plectophora arachnoides, Haeckel. PlagiacantJia arachnoides, var., Claparfede, 1858, !lfitudes sur les Infusoires et los Ehizopodes, p. 462, Taf. xxii. fig. 9. Spines straight, cylindrical, trifid, with one pair of lateral branches. The nine diverging, straight, and smooth branches are connected in the distal part by slender concave bows, so that the whole skeleton exhibits nine wide meshes, three larger pentagonal and six smaller triangular. Bimensions. — Length of the spines 014, of their branches O'OV. Habitat. — North Atlantic, west coast of Norway (Claparfede), surface. ^ Plectophora = ^eB.Tmg a hunting net ; ■TrTiiKxti, (pi^m. REPORT ON THE RADIOLARIA. 923 3. Plectophora novena, n. sp. Spines slightly curved, tliree-sided prismatic, thorny, with two pairs of lateral branches. The six smaller distal brauches end freely, whilst the six larger basal branches are connected by slender convex bows. There are therefore nine wide meshes, as in the preceding closely allied species. Dimamons. — Length of the spmes O'lS, of the basal branches 0'08. Habitat. — North Atlantic, Fajroe Channel (Gulf Stream) (John Murray), siu'face. 4. Plectophora pyramidalis, u. sp. Spines straight, three-sided prismatic, with three to four verticils of short lateral branches. The branches of the basal verticils are again ramified, and form by connecting bows a delicate loose framework, covering the three sides of a flat pyramid, the three edges of which are the three radial spines. BimensioTis. — Length of the spines 0'2, base of the pyramid 0'16. Habitat. — Central Pacific, Station 267, surface. Subfamily 2. Teteaplectida, Haeckel, 1881, Prodromus, p. 424. Definition. — P lectanida with four radial spines. Genus 395. Tetrcqolecta^ Haeckel, 1881, Prodromus, p. 424. Definition. — P lectanida with four equal radial spines, arising from one common central point and corresponding to the four axes of a tetrahedron. The genus Tetraplecta has been derived from Tetraplagia by union of the neighbour- ing branches of the four radial spines, diverging from a common point in different directions. In some forms of this genus the four rods seem to correspond exactly to the four axes, which are directed from the centre of a tetrahedron towards its four corners ; whilst in other forms the four- rods and the angles between them are perhaps not perfectly equal 1. Tetraplecta tetrahedra, n. sp. Spines straight, equal, three-sided prismatic, pinnate, each with three or four pairs of opposite straight slender pinnulse or lateral branches ; the pinnule of each side are correspondingly parallel ' Teiroptoa = Hunting net with four beams ; tst^o., ■n^.ixTti. 924 THE VOYAGE OF H.M.S. CHALLENGER. All pinnulse connected by a few slender bridges, thus producing a delicate network with irregular rhomboidal meshes. Dimensions. — Length of the spines 0'15, of the basal branches 0"05. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 2. Tetraplecta quadricornis, n. sp. Spines in the basal half straight, in the distal half slightly curved and irregularly branched, with two to three pairs of unequal alternate lateral branches, the distal ends of which are connected by a few slender bows, marking the six edges of an irregular tetrahedron. Dimensions. — Length of the spines 0"22, of the basal branches 0'14. Habitat. — Central Pacific, Station 2G6, depth 2750 fathoms. 3. Tetraplecta pinigera, n. sp. (PI. 91, fig. 8). Spines three-sided prismatic, straight, or in the basal half slightly curved, verticillate ; each spine with six to eight three-branched regular verticils, tapering gradually towards the distal end. All branches of each spine lie parallel in three equidistant meridian planes, and are connected by delicate parallel threads, perpendicular to the branches. Therefore the skeleton consists of four pine-shaped trees and twelve delicate triangular wings with rectangular meshes. Dimensions. — Length of the spines 0'25 to 0'3, of the basal branches 0"1 to 015. Habitat. — Central Pacific, Station 271, surface. Genus 396. Plectaniscus,^ nov. gen. Definition. — P lectanida with four unequal radial spines, arising from one common central point ; one vertical or apical spine opposed to three divergent or basal spines. The genus Plectaniscus has probably been derived from Plagoniscus by reticular union of the neighbouring branches of the four radial spines, and exhibits therefore to it the same relation that Tetraplecta bears to Tetraplagia. Whilst in these two latter genera the four spines are equal, in the two former genera there is an important differ- ence between a vertical spine (or apical horn) and three divergent (commonly larger) spines, corresponding to the three basal feet of the triradiate Nassellaria. Perhaps, therefore, Plectaniscus is one of the remotest ancestors of the latter ; but differs in the absence of a complete lattice-shell. 1 PZectamsaw = Shell of wickerwork ; TXexTai/Zuxo;. REPORT ON THE RADIOLARIA. 925 1. Plectanisctis cortiniscus, u. sp. (PL 91, fig. 9). Spines straight, three-sided prismatic, with three to four verticils of short perpendicular branches ; the branches of the distal verticils are simple and free, those of the proximal verticils again ramified and connected by an arachnoidal network of delicate threads. The vertical apical spine (or horn) is scarcely one-third or half as long as the three divergent basal spines (or feet), and the angle between it and the latter is smaller. Dimensions. — Length of the apical spine 0'05 to O'l, of the three basal spines 018 to 0'2. Hahitai. — North Pacific, Station 244, surface. 2. Plectaniscus tripodiscus, n. sp. Spines curved, cylindrical, with a variable number of irregular branches, which in the distal half of the spines are free, in the basal half again ramified and connected by a loose spongy frame- work. The apical spine is shorter and simpler, nearly straight, less ramified. BiTnensions. — Length of the apical spine Ol, of the three basal spines 015 to 018. HaMtat. — North Pacific, Station 238, surface. 3. Plectaniscus archiscenium, n. sp. Spines slightly curved, three-sided prismatic, with two to three verticils of short curved branches. The vertical apical spine is about twice as long as the three basal spines, and connected with them by an irregular loose framework. The three basal spines are connected together only by a simple ring, so that between them remain three large coUar holes, like those of the similar and closely allied Archiscenium quadrispinum (PI. 53, fig. 11). Dimensions. — Length of the apical spine 0'32, of the three basal spines 018. HaMtat. — South Pacific, Station 295, depth 1500 fathoms. 4. Plectaniscus cladoscenium, ru sp. Spines curved, three-sided prismatic. The three basal spines pinnate, with four to five pairs of opposite curved pinnulae ; the distal pairs are simple and free, the basal pairs branched and connected by an irregular delicate framework, which together with the apical spine forms a spongy cap-shaped shell, similar to Cladoscenium. Apical spine about half as long, simple. Dimensions. — Length of the apical spine 01, of the three basal spines 018, Habitat. — Central Pacific, Station 274, surface. 5. Plectanisctis clatKi'ocorys, n. sp. Spines straight, three-sided prismatic, with seven or eight verticils of ramified branches, which in the basal half are connected by an irregular loose framework. In the distal half each of the three divergent basal spines (or feet) is connected with the longer apical spine (or horn) by a 926 THE VOYAGE OF H.M.S. CHALLENGER. fenestrated triangular lattice wing. Therefore the skeleton becomes very shnilar to Clathrocorys (PI. 64, figs. 8-10), but wants the regular central cephalis. Dimensions. — Length of the apical spine 0'2, of the basal spines 0'14. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 397. Periplecta,^ Haeckel, 1881, Prodronms, p. 424. Definition — P lectanida with four unequal radial spines, arising in pairs from the two poles of a common central rod ; one ascending apical spine opposed to three descending basal spines. The genus Perij^Iecta has probably been derived from Plagiocarpa (by concrescence of the meeting sj^ine branches), and has the same important relation to a part of the triradial Stephoidea ( Cortina, &c. ) and Cyrtoidea (Pteroscenium, &c. ). It differs from the latter only in the fact that the loose nregular framework connecting the bases of the four cortinar spines is not a regular lattice-shell. 1. Periplecta cortina, n. sp. (PI. 91, fig. iO). Spines of very different size and shape, three-sided prismatic. The apical spine (or horn) is larger, nearly straight, and bears a verticil of three large divergent branches, which are again ramified. The three basal spines (or feet) are curved, pinnate, each with three to five pairs of opposite simple curved branches. A smaU common central rod separates the two united pectoral feet from the two other spines (the caudal foot and the apical horn). The three basal feet are connected by three convex bows composing a horizontal collar ring, and since the central rod is prolonged between the pectoral feet to the ring, a very remarkable collar SQptum is formed with four cortinar meshes. Above this septum an irregular spongy shell, including the central capsule, is formed by a delicate framework, interwoven between the apical horn and the three basal feet. Dimensions. — Length of the apical spine 0'25 to 0'3, of the three basal spines 0'15 to 0'2. Habitat. — Central Pacific, Station 27l, surface. 2. Periplecta pteroscenium, n. sp. Spines of very different size and shape, three-sided prismatic, verticillate. The apical sjune (or horn) with ten to twelve verticils, is one and a half times as long as the three basal spines (or feet), which bear six to eight verticils only; each verticil with three branches which by communicating ramules form a loose irregular wickerwork. Similar to Pterosccni^im pinnatuvi, PI. 53, figs. 14-16, but without a regular lattice-shell. A short basal central rod separates two equal (pectoral) spines from two unequal spines, the larger of the latter is the apical, the shorter the caudal spine. Dimensions. — Length of the apical spine 0-26, of the three basal spines 0-17. Habitat. — Central Pacific, Station 274, surface. 1 Periplecta = Surrounded Ijy a hunting net ; tc^I, ■ahex.Tti. REPORT ON THE RADIOLARIA. 927 3. Periplecta monocyrtis, u. sp. Spines of nearly equal size and shape, cylindrical, irregularly branched. The apical spine is straight, more branched and nearly twice as long as the three basal spines. All four spines in the basal third connected by a loose spongy framework, approaching the form of some Monocyrtida. Dimensions. — Length of the apical spine 024, of the basal spines 0'13. Habitat. — Central Pacific, Station 274, surface. Subfamily 3. Hexaplectida, Haeckel, Definition. — P lectauida with six radial spines. Genus 398. Hexaplecta,^ Haeckel, 1881, Prodromus, p. 425. Definition. — P lectanida with six radial spines, arising from one common central point. The genus Hexajylecta has probably been derived from Hexaplagia by concrescence of the meetiag branches of the six spines, and therefore has to it the same relation that Plectophora bears to Plagiacantha. The two species here described represent perhaps two different genera, since in the first all six spines are equal, opposed in pairs, in the second different in pairs (three upper smaller and three lower larger), 1. Hexcvplecta triaxonia, n. sp. Spines equal, opposite in three crossed pairs, straight, three-sided prismatic, thorny, in the distal half with three leaf-shaped, dentate edges, in the basal half with three verticils of slender branches, which axe connected by parallel threads, and so form an arachnoidal network with rect- angular or rhomboidal meshes. Dimensions. — Length of the spines 0'22, of their basal branches 0"06. Habitat. — South Pacific, Station 285, depth 2375 fathoms. 2. Hexaplecta tricladonia, n. sp. Spines unequal, three larger spines (in the lower half of the body) being opposite to three smaller spines (in the upper half). The latter are nearly horizontally expanded, each bearing three straight divergent branches. The larger are stronger, twice as long and armed with three verticUs, each of three branches. All six spines are slender, three-sided prismatic. Their branches are very thin, thread-shaped, and form by their union a loose network with irregular polygonal meshes. Dimensions. — Length of the larger spines 0"25, of the smaller 0"12. Habitat. — South Pacific, Station 291, surface. 1 Hexajplecta = Hunting net with six beams ; ?|«, ■z'kiKTn. 928 THE VOYAGE OF H.M.S. CHALLENGER. Genus 399. Plectanium,^ Haeckel, 1881, Prodromus, p. 424. Definition. — P lectanida with six radial spines, arising in two opposite divergent groups from the two poles of a common central rod. The genus Plectanium has been derived from Plagonium by concrescence of the meeting branches, and bears therefore to it the same relation that the preceding IIexa]r)lecta exhibits to Hexaplagia. Whilst in these two latter genera the six spines arise from a common central point, they arise here in two divergent groups from the two poles of a horizontal common middle rod, similar to the spicula of many B e 1 o i d e a. 1. Plectanium trigeminum, n. sp. (PL 91 ^ fig. 11). Spines .straight and stout, six to eight times as long as the common middle rod, three-sided prismatic ; in the distal half thickened, with three divergent terminal thorns ; in the basal lialf with three to four verticils of thin lateral branches, which are again ramified, and by their united threads produce an irregular loose framework. Dimensions. — Length of the spines 0'25, basal breadth 0"005, terminal breadth 0'02; length of the middle rod 0-03. Habitat. — North Pacific, Station 244, surface. 2. Plectanium ovodimare, n. sp. Spines straight and stout, three-sided prismatic, about four times as long as the common middle rod, gradually thinned towards the distal end ; in the basal half with 'two to three verticils of forked branches, which are dichotomously ramified, and by their united threads form a loose ovate framework. Dimensions. — Length of the spines 017, of the middle rod 0'04. Habitat. — North Pacific, Station 236, surface. 3. Plectanium sphcerozoum, n. sp. Spines straight, cyhndrical, ten to twelve times as long as the common middle rod, with six to eight verticUs of thorny branches, tapering towards the distal end; the branches of the verticils are simple in the distal half, again ramified in the basal half, and here connected together by irregularly branched threads forming a loose framework. (Eesembles one spiculum of Sphcerozoujn vcrtieillcUum, PI. 4, fig. 7, but is more richly branched, with united ramules.) Dimensions. — Length of the spines 0-2, of the middle rod 0-01. Habitat. — Central Pacific, Station 26G, surface. * Plectanium=Sma,]l wickerwork or network ; iry^txrxuYt. EEPOET ON THE RADIOLAEIA. 929 Subfamily 4. Polypleotida, Haeckel, 1881, Prodromus, p. 424. Definition. — P 1 e c t a n i d a witli numerous (seven to nine or more) radial spines. Genus 400. Polyplecta,^ Haeckel. Definition. — P 1 e c t a n i d a with numerous (seven to nine or more) radial spuies, arising from a common centre and lying in different planes. The genus Polyplecta comprises provisionally all Plectanida possessing seven or more radial spines, united in the centre of the framework. It may be derived from Polyplagia by meeting and concrescence of the free branches. But as in the latter genus, here also the few observed species are very different, perhaps of different origin, and may be afterwards better separated as representatives of diverse genera. 1. Poli/plecta heptacantha, n. sp. (PI. 91, fig. 12). Heptaplegma heptacantha, Haeckel, 1882, MS. Seven unequal spines divergent from one common central point, slender, slightly curved, three- sided prismatic. Four spines are much larger, twice to three times as long and as thick as the three smaller spines. One of the four larger spines is directed upwards (as " apical horn "), whilst the three others diverge downwards (as " basal feet "). Each of the four larger spuies bears five to seven equidistant verticils of three divergent branches, the proximal of which are branched, the distal simple. The three smaller spines He nearly horizontally, midway between the odd apical spine and the three basal spines, and in the same meridian planes with them ; each bears one verticil of three divergent branches. All the branches are united by arachnoidal threads, composing a loose wickerwork with irregular, generally quadrangular meshes. Dimensions. — Length of the four larger spines 0'27 to 0'33, of the four smaller 01 to 014 Habited. — Central Pacific, Station 271, surface. 2. Polyplecta emieacantha, n. sp. Enneaplerjina enneacantha, Haeckel, 1881, Prodromus, p. 425. Mne equal and equidistant, straight, cylindrical radial spines, lying nearly in one plane, arise from an irregular spongy central framework; six , of them seem to be secondary, intercalated between three equidistant primary spines, which are united in the centre. (This species resembles in the nine-radial structure the remarkable EnneaphorTnis rotula, PI. 57, fig. 9, and may perhaps be derived from a similar species ; but it has no regular latticed shell.) Dimensions. — Length of the spines 0'22, diameter of the framework 017. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 1 Polyplecta = M.\i(h. entwined ; ttoAi/ttAsxtoj. (ZOOL. CHALL. EXP.— PART XL. — 1886.) Er 117 930 THE VOYAGE OF H.M.S. CHALLENGER. 3. Polyplecta decacantha, n. sp. Pentaplegma decacantha, Haeckel, Prodromus, p. 425. Ten radial spines, curved, cylindrical, irregularly branched, diverge in different directions and seem to arise in pairs from an irregular central framework, in the centre of which five primary spines are united ; the latter correspond probably to the five spines of Pentasinjris, &c. The density of the spongy central framework did not allow of an accurate investigation, and makes it doubtful whether this species is not a Spongionwia. Dimensions.- — Length of the spines 0'3 to 0'4, diameter of the framework 0'18. Hcibitat. — Tropical Atlantic, Station 338, depth 1990 fathoms. 4. Polyplecta polyhrocha, Haeckel. "l Acantliodesmia polybrocha, Haeckel, 1865, Zeitschr. f. wiss. Zool., Bd. xv. p. 3G8, Taf. xxvi. fig. 3. Plegmosphcera polyhrocha, Haeckel, 1881, Prodromus, p. 455. Numerous (twenty to thhty or more) radial spines, thin, cylindrical, curved and irregularly branched, arising from an irregular central spongy framework, are connected by numerous slender arches. The specimen observed by me in 1880 in Portofino was a true Polyplecta, with three primary spines centrally united, between which numerous other spines were intercalated. The similar specimen, however, observed in 1864 in ViUafranca, and figured, loc. cit., was perhaps a Plegmosphcera. Dimensions. — Length of the radial spines 0'05 to 0"1, diameter of the fi-amework 0"16. Habitat. — Mediterranean (ViUafranca, Portofino), surface. 5. Polyp>lecta dumetum, Haeckel. Acanthodesmia dumetum, J. MiiUer, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 30, Taf. i. fig. 3. Numerous (ten to twelve or more) radial spines, thin and straight, with a few straight lateral branches, diverge in different directions and are connected by a few slender curved arches. Some similar forms, but more developed, with numerous branches and curved rods, are found in the Pacific Eadiolarian ooze, and represent probably different species. Dimensions. — Length of the radial spines 0-05 to 0-08, of the branches 0'02 to 0-03. Habitat. — Mediterranean, French shore (Cette and Saint Tropez), Johannes MuUer, surface REPORT ON THE RADIOLARIA . 931 Suborder III. STEPHOIDEA, Haeckel. Stephoidea vel Stephida, Haeckel, 1881, Prodromus, p. 444. Acanthodesmida [sensu ampliori), Biitschli, 1882, Zeitschr. f. wiss. ZooL, vol. xxxvi. p. 495. Definition. — Nassellaria without complete lattice-shell, with a skeleton composed of one or more simple rings, which may be united l)y a loose framework and are separated by large openings or gates. One primary or sagittal ring, determining the sagittal or median plane of the l^ilateral body, encloses the monaxonian central capsule. The suborder Stephoidea, hitherto known by a few species only of " Acantho- desmida," comprises a large number of interesting Nassellakia (now more than two hundred species), which possess peculiar interest for the morphology and phylogeny of this legion. The monaxonian central capsule of the Stephoidea is surrounded either by one simple ring or by a complex system of several loosely connected rings ; these may be united by a loose framework of connected branches, but never produce a com- plete lattice-shell, as is constantly the case in the S p y r o i d e a, B o t r y o d e a, and Cyrtoidea. Therefore there remain between the parts of the connected rings a few large openings which we call "gates," separating them from the numerous small "pores" of the complete lattiee-sheUs. In the most simple case, if only one ring be formed, there is also present only one " gate," the aperture of this simple ring. The first known species of Stephoidea were observed in the Mediterranean by Johannes Mtiller in 1856, and described and figured in his last treatise (1858) under the names Lithocircus annidaris {loc. cit., Taf. i. fig. 1) and Acanthodesmia vinculata (loc. cit., Taf. i. figs. 4—7). In the following year I myself observed two other living species in the Mediterranean, and described them in my Monograph (1862, pp. 268, 270) as Zygostephanus muUeri (Taf xii. fig. 2) and Prismatium tripleurum (Taf iv. fig. 6). For these four longest known Stephoidea I founded the new family of Acanthodesmida {loc. cit., p. 265), but united with them two other similar genera which I afterwards separated : — Plagiacantha (belonging to the Plectoidea) and Dictyocha (belonging to the Ph^odaria). When, in 1876, I received the rich material of the Challenger collection, I was astonished to find in it an enormous number of new, similar, and partly very interest- ing "Acanthodesmida," which were afterwards arranged in my Prodromus (1881, p. 444) in thirty-eight tlig"erent genera and four " subfamilies," all united in one single large family, " Stephida or Monopylaria cricoidea." I retain here this natural group in the same sense, but give to it the rank of a " suborder," separating at the same time its four subfamilies as substantial "families." Since the names of the 932 THE VOYAGE OF H.M.S. CHALLENGER. latter, proposed in the Prodromus, were not quite suitable, I replace tliem here by the following more convenient names : — 1. Family Stephanida ( = Monostephida, 1881, p. 447). Skeleton entirely formed by one simple ring (the primary vertical sagittal ring). The only " gate " is the simple aperture of the ring. 2. FamUy Semautida ( = Dyostephida, 1881, p. 446). Skeleton composed of two rings, perpendicular to one another ; the primary vertical sagittal ring bears at the base a horizontal basal ring ; between the two rings two or more " basal gates remain." 3. Family Coronida ( = Triostephida, 1881, p. 445). Skeleton composed of two crossed vertical or meridional I'ings, perpendiciilar to one another — the primary sagittal ring and the secondary frontal ring. Commonly the two vertical rings are united at the base by a horizontal basal ring, and between them remain two or more " basal gates." 4. Family Tympanida ( = Parastephida, 1881, j). 446). Skeleton composed of two parallel horizontal rings, an upper mitral ring, and a lower basal ring, both connected by vertical or divergent columellse, which are parts of vertical rings (primary sagittal, and secondary frontal ring). The peculiar structure of the central capsule of the Stephoidea, and their character as true Monopylea, were first recognised by Richard Hertwig, who in 1879, in his Organismus der Radiolarien, gave an excellent detailed description of it {loc. cit., pp. 68—72, Taf. vii. figs. 4, 5). He also pointed out the near affinity of these " Acanthodesmida " with the S p y r o i d e a or Zygocyrtida, uniting the latter with the fo^er family. A fuller explanation of this affinity, and of the great morphological and phylo- genetic importance of the "Acanthodesmida," as ancestral forms of the Spyroidea and Cyrtoidea, was given in 1882 by Biitschli (Zeitschr. f. wiss. ZooL, vol. xxxvi. pp. 495-501). He described in detail some important fossil forms of Acanthodesmida as diflerent species of " Stephanolithis," a name which Ehrenberg had employed for various ring-like fragments of Radiolarian shells, sponges, and other fossil bodies. The four fossd species which Biitschli described represent four different genera of Stephoidea, viz., Semantis [spinescens), Semantrum [miilleri), Semantidium (haeckelii), and Tristephanium (hertwigii). On the phylogenetic conclusions, derived from these accurate observations, compare above, p. 893, &c. The topographical sigiirfi- cation of the parts, employed by Biitschli, is contrary to mine ; he calls my dorsal side the " anterior," and my ventral side the " posterior." The geometrical fundamental form of the body in nearly all Stephoidea (with few exceptions) is distinctly bUateral or " dipleuric," so that we can easily distinguish the REPORT ON THE RADIOLARIA. 938 three different dimensive axes : the principal axis with different apical and basal poles, the sagittal axis with different dorsal and ventral poles, and the lateral axis with equivalent right and left poles. In only a few genera this bilateral symmetiy is not expressed, and a simpler, more regular fundamental form appears. The latter may be either primary (in the mouaxonian Archicircus and Lithocircits) or secondary, afterwards acquii-ed (in the octahedi'al Trissocircus and Trissocyclus, the cubical Lithocuhus, the prismatic Eutympanium, and some other forms). The most important element of the skeleton, with which its formation begins, in all S t e p h o i d e a is the simple primary or sagittal ring, lying vertically in the sagittal or median plane of the body and surrounding the monaxonian central capsule. This sagittal ring is the only essential element of the skeleton in all Stephanida, and is completely preserved in all Semantida, also in the greater part of the Coronida and Tympanida. It is partially reduced in the small groups of the true Acanthodesmida (subfamily of Coronida) and the Dystympanida and Eutympauida (subfamilies of Tympanida). Here only the vertical parts of it are preserved (dorsal and ventral rod), whilst the horizontal jjarts are lost (mitral and basal rod). The sagittal ring lies constantly in the vertical median plane of the body, and therefore divides the enclosed central capsule into a right and a left half. It is rarely regular or subregular, commonly dipleuric or distinctly bilateral, so that w^e may easily distinguish its dorsal and ventral, apical and basal parts. The most important of these four parts or " rods " is the " basal rod " or the inferior part, because here the ring is in closer connection with the central capsule and its "porous area"; here peculiar spines or branches are commonly developed, which even on the isolated ring immediately determine the basal pole. The opposite upper part, or the " mitral rod," is also often distinguished by peculiar appendages. The posterior part, or the " dorsal rod " (the anterior rod, a, in the description of Biitschli), is commonly more straight, often quite vertical. The opposite anterior part, or the " ventral rod " (the posterior rod, h, of Biitschli), is usually more convex, and often strongly curved or semicii'cular. Whilst this dipleuric or bilateral (commonly oblic^uely ovate or nearly triangular) form of the sagittal ring is distinctly preserved in by far the greater number of S t e p h o i d e a, it is replaced in some few genera by a more regular, amphithect, diphragmatic, or biradial form. In this case we may often suppose a primary regularity to exist, the dorsal and ventral parts being not yet differentiated, as in Archicircus and Lithocircus, Zygo- stephanus and Profymjxtnium, and perhaps also in some other forms. But in other cases the regularity is, on the contrary, secondary, being derived from original bilateral forms. The rod of the sagittal ring is either cylindrical (with circular transverse section) or angular (commonly with triangular transverse section). In nearly all S t e p h o i d e a (with very few exceptions) branches or apophyses are developed from the ring, regularly disposed and often of very great morphological importance. Commonly these 934 THE VOYAGE OF H.M.S. CHALLENGER. apophyses are developed in pairs, growing symmetrically on both sides of the ring. The most important of these apophyses are : — (l) basal apophyses, arising from the basal pole of the ring ; (2) mitral apophj^ses, arising from the apical pole ; (3) dorsal apophyses, arising from the middle of the dorsal rod ; and (4) ventral apophyses, arising from the middle of the ventral rod. The two former arise in the principal axis, the two latter in the sagittal axis of the body. Very frequently the latter pair is replaced by two paii's of transverse branches, one inferior (mandibular) and one superior (orbital). The apophyses of the ring are either simple or branched, often very large, richly ramified, and give origin to a number of further products. Whilst in the Stephanida the primary sagittal ring alone represents the whole skeleton, it produces in all other Stephoidea one or more secondary rings. The most important of these is the horizontal basal ring, appearing first in the Semantida (PL 92). From the base of the sagittal ring there arise in the horizontal basal plane two pairs of lateral branches or " basal apophyses." The curved opposite branches of the corresponding pairs become united on each side of the primary ring (right and left), and so produce a second, horizontal ring, perpendicular to the former. This basal ring encloses two paired basal gates, which are enclosed on the medial side by the basal rod of the sagittal ring, and on the lateral side by two united apophyses (Semantis, PI. 92, figs. 1, 2). These two primary basal gates are of the greatest morphological importance; we call them the "jugular gates or jugular pores " (in the descrij^tion of Biitschli, the pores I, loc. cit., p. 498). Tlie dorsal jaair of basal apophyses (on their posterior edge) are the coracal rods, e (rods e of Biitschli) ; the opposite ventral pair (on their anterior edge) are the clavicular or furcular rods, y (rods el of Biitschli); compare Pis. 92-95, and their explanation. The skeleton of Semantis, the prototype of the Semantida, thus assumes the characteristic form of a signet-ring. The basal ring enclosing the two jugular pores corresponds to the seal-plate. It is commonly more or less horizontal ; but often the apophyses descend obliquely (PL 92, figs. 1, 2, 13, &c.), more rarely laterally (PL 29, fig. 11). The further development of this typical form is essentially efi"ected by the production of new basal pores in the horizontal seal-plate. In Seinantrum (PL 92, figs. 3, 4, 5) we find already four basal gates. Behind the jugular gates is formed a second pair, the " cardinal gates " (pores II of Biitschli). These are enclosed on the anterior margin by the coracal rods (e), on the posterior margin by the scapular rods (d), a third pair of basal apophyses, arising behind the former from the sagittal ring and uniting with them (the rods e2 of Biitschli). Commonly the two posterior, or cardinal gates are much larger than the two anterior, jugular gates. This characteristic basal plate of Semantrum, with two pairs of basal pores, is of the greatest morphological importance, as it is inherited in by far the greater number of the Nassellaeia, though not so generally as Biitschli supposes. The basal ring of Semantrum is either more circular REPOET ON THE EADIOLARIA. 935 ¥ or elliptical, or more polygonal, and is connected with the basal rod of the sagittal ring by three paii'S of radial apophyses, the anterior furcular, the middle coracal, and the posterior scapular rods. A thiixl important form of Semantida is Semantidium (PI. 92, figs. 6, 7). Here we find three pairs of basal j3ores in the seal-plate ; the third pair, newly formed, consists of the cervical gates (e), bounded in front by the scapular rods {d), behind by a fourth pair of basal apophyses, the cervical rods. The basal apophyses of the sagittal ring are not only of great morphological importance, because they produce by their union three typical pairs of basal gates or " collar pores," but also because their prolongations often appear as typical basal feet. The distal prolongations of the coracal rods appear in Semantiscus (PI. 92, figs. 16—18) as two pectoral feet, those of the scapular rods as two tergal feet, whilst the opposite prolongations of the basal rod of the sagittal ring appear as two " sagittal feet " (in front an anterior or sternal, and behind a posterior or caudal foot). In the typical Cortiniscus (PI. 92, figs. 11-13) only three feet are developed; an odd caudal and two paired pectoral feet (compare above, p. 891). The typicah basal ring of the Semantida, with its paired basal gates (Seinantis), reappears in the majority of the Coronida, differing from the former in the development of a second vertical ring, which lies in the frontal plane (perpendicular to the sagittal ring), and which we therefore call the frontal ring. In only one small group of the Coronida the basal ring is absent, namely, in the Zygostephanida, and here the frontal ring appears in the simplest form, as a complete elliptical meridian ring, crossing the sagittal ring perpendicularly on the two poles of the main axis (^Zygostejjhanus, PI. 93, figs. 1—4). Four large lateral gates between the two rings remain open. This form may be derived directly irom. the Stephanida in the following way; fr'om both poles of a simple sagittal ring there arise two opposite lateral apophyses, which in the frontal plane become curved one towards the other, and united in the poles of the transverse axis. The basal apophyses would be the coracal rods. But it is also possible that Zygostephanus was derived from Semantis by the loss of the furcular rods. The three typical rings (or the " dimensive rings ") of the Stephoidea appear in their most complete form in the subfamily Trissocyclida (PI. 93, figs. 7, 13). Here all three rings are undivided and completely developed in the three dimensive planes, perpendicular one to another. Between them there remain eight large open gates ; the four superior are the four " lateral gates " of Zygostephanus, the four inferior are the four basal gates of Semantrum. The four latter are originally much smaller than the four former; but in Trissocircus and Trissocyclus (PI. 93, figs. 10—12) they reach the same size. Therefore all eight gates are here of equal form and similar size, and the basal ring, now a true equatorial ring, divides the two meridional rings into two equal halves. In the Eucoronida, a thuxl subfamily of Coronida, the sagittal and the basal rings 936 THE VOYAGE OF H.M.S. CHALLENGER. are complete, but the frontal ring is incomplete, its basal part being wanting (PL 82, figs. 4—6). Therefore we find here six large gates between the three rings; four upper lateral gates (between the two crossed vertical rings) and two lower basal gates (between the basal rod of the sagittal ring and the two halves of the basal ring). Eucoronis, the type of this subfamily, may be derived either directly from Seviantis by development of a frontal ring, or from Tristephanium by loss of the basal part of the frontal ring. A quite simple basal ring, with a single gate, distinguishes the fourth subfamily of Coronida, the Acanthodesmida (sensu restricto), the genera Coronidium (PI. 82, figs. 1, 2, 7, 8) and Acanthodesmia (PI. 93, fig. 5). The horizontal basal ring alone is here complete, whilst both vertical rings (the sagittal and frontal rings) are incomplete, their basal parts being wanting. Therefore there are here five gates, four lateral and one basal. These forms may be derived from Eucoronis by loss of the basal rod of the primary sagittal ring. The Tympanida, the fourth family of S t e p h o i d e a, exhibit another type of ring structure. Here two parallel horizontal rings are constantly developed, one on the apical pole, the other on the basal pole of the sagittal ring. The latter is the same basal ring as in the Semantida and Coronida. The former is a " mitral ring," developed in the same manner, by union of two paii's of horizontal lateral branches, which arise on both sides from the apical rod (or mitral rod) of the sagittal ring. In the simplest case these two parallel horizontal rings are connected only by the sagittal ring, which is either complete (Pi'ott/mjxinium, PL 93, fig. 14) or incomplete (Parastephamis, PL 93, fig. 21). But commonly also an incomplete frontal ring is present, so that the two horizontal rings are connected by four vertical or subvertical rods ; two of these " columellse " are the dorsal and ventral rods of the sagittal ring, the two others are the lateral rods of the frontal ring. Between the former and the latter are sometimes developed two, four, or more accessoiy columellse (probably halves of accessory incomplete diagonal meridian rings). In this way arise the characteristic " drum-forms " of many Tympanida, in which the two parallel horizontal rings correspond to the upper and lower rings of a drum, whilst the connecting vertical columellse correspond to its parallel lateral rods (PL 83, figs. 1, 2, &c.). Originally the two horizontal rings of these " drum-shells " are both bisected by the complete sagittal ring, each provided with two lateral gates (Protympanida). But in the Eutympanida both i-ings exhibit one simple gate only, the apical and the basal rod of the sagittal ring being lost. In the Paratympanida both rings are closed by a secondary lattice -plate, whilst in the Dystympanida the upper (mitral) ring alone is closed by such a plate, the lower (basal) ring is open. In some Eutympanida the shell assumes the strange form of a regular geometrical cube, the twelve edges of which are represented by thin rods of silex [Lithocuhus) — its four upper edges represent the mitral ring, the four lower the basal ring ; two opposite of the four vertical cube- REPORT ON THE RADIOLARIA. 937 edges arc the lateral halves of the frontal ring, the two other alternate ones are the remaining halves of the reduced sagittal ring (dorsal and ventral rod) (PI. 82, fig. 12). In many Tympauida and Coronida a loose irregular lattice or framework is developed, which partly closes the large open gates. But this never reaches the com- pleteness of a true lattice-shell, such as we find in the Spj'roidea, Botryodea, and C y r 1 0 i d e a. In by far the greater number of Stephoidea the corners, and partly also the rods, of the shell are armed with numerous ii-regular spines, often forked or richly branched. Among these spines the descending " basal apophyses " possess a peculiar importance, since by their regular number and disposition they correspond to the radial rods of the Plectoidea, and to the tyjaical " feet " of the Spyroidea and Cyrtoidea. The most important of them are the three cortinar feet (one caudal and two pectoral) of Cortina, Cortiniscus, &c. (compare above, p. 891). T/ie Central Capsule exhibits in the Stephoidea the same characteristic structure as in all other Monopylea, first exactly pointed out by Richard Hertwig in 1879 (Organismus der Radiol., p. 71, Taf. vii. figs. 4, 5). Its form is commonly ovate or ellipsoidal, sometimes also lentelliptical or nearly spherical. It exhibits constantly on the basal pole the porochora or porous area, and in the basal half the podoconus or pseudopodial cone. From the surrounding sagittal ring it is separated by a thick jelly-like calymma, which commonly exhibits numerous zooxanthellse. The numerous pseudopodia are commonly branched, with rather rare anastomoses. The membrane of the central capsule is thick. Synopsis of the Families of Stephoidea. I. Skeleton composed of the simple vertical sagittal ring only, without secondary rings, ......... II. Skeleton composed of two crossed rings, a vertical sagittal and a horizontal basal III. Skeleton composed of two crossed vertical meridional rings (a primary sagittal and a secondary frontal ring), cominonlj' also with a horizontal basal ring, . 3. Coronida. rV. Skeleton composed of two parallel horizontal rings (upper mitral and lower basal ring), both connected by a vertical sagittal ring (and often by a vertical frontal ring), ......... 4. Tympanida. Family XLVIII. Stephanida, Haeckel (PL 81). Monostephida, Haeckel, 18S1, Prodromus, p. 447. Definition. — S t e p h o i d e a with a simple sagittal ring, without any lattice-work. The family S t e p h a n i d a is the most simple of aU Stephoidea, and probably the common ancestral group of this suborder (compare above, p. 933). The skeleton (ZOOL. CHALL. EXP. PART XL. — 1886.) Rr 118 938 THE VOYAGE OF H.M.S. CHALLENGER. consists of a simple ring only, surrounding the central capsule, and armed commonly with simj)le thorns or with larger branched spines. The branches of these spines are constantly free, never joining together. Therefore the shell exhibits no trace of fenestration or lattice-work, no pores or gates, except the simple large gate of the ring itself. In all other S t e p h o i d e a we find secondary gates or lattice-work. The first known form of this family is Litliocircvs annularis, described by Johannes Miiller in 1858 (Abhandl. d. k. Akad. d. Wiss. Berlin, p. 29, Taf. i. fig. 1). He observed already the central capsule (" Blase ") surrounded by the circular ring of silex, and the calymma (" Strahlige Gallert ") enveloping the whole body. The peculiar structure of the soft body, particularly the " area porosa " on the basal pole of the central capsule, and the pseudopodial cone within it, were first accurately described by Hertwig (in 1879). A great number of simple rings, similar to these, were found in the Challenger collection, and are here arranged in six genera and forty-eight species. The simjDle ring of silex, which alone forms the skeleton of the Stephanida, corresponds to the primary or sagittal ring of the other Stephoidea, and lies there- fore vertically in the median or sagittal plane of the body. We can therefore distinguish on it four diff'erent segments, rods or bows, two of which are more horizontal, two more vertical. The former are one upper bow or apical rod, and one lower bow or basal rod. The latter are one posterior bow or dorsal rod, and one anterior bow or ventral rod. Sometimes each of these four component bows is distinguished by a corner-spine, or by a pair of divergent branches. In the two simplest (and probably oldest) genera of Stephanida, in Archicircus and Lithocrrcus, the dorsal and ventral rods of the ring are equal and cannot be distinguished ; therefore the fundamental form is here amphithect, diphragmatic, or biradial (the poles of the sagittal axis being equal). In the four other genera the dorsal rod is more straight (often vertical) and more or less difi"erent from the ventral, convexly curved rod ; therefore the fundamental form is here dipleuric or bilateral, as in the greater number of all Nassellaria (the poles of the sagittal axis being unequal).. The general form of the ring in this latter case is commonly obliquely ovate or nearly triangular, the basal pole being more pointed, the apical pole more rounded (PL 81). The rods or bows of the ring are either roundish or cylindrical (with circular or elliptical transverse section), or they are prismatic or angular (commonly with triangular transverse section). In the latter case one edge usually is prominent in the sagittal plane (on the convex outside of the ring), whilst two other edges diverge laterally on both sides of it. The inner or concave margin of the ring is commonly smooth. The inner perimeter of the large gate, enclosed by the ring, is commonly rounded (elliptical or ovate), rarely angular. However, the outer perimeter of the ring is REPORT ON THE RADIOLARIA. 939 nearly always polygonal, with prominent corners, and usually from these arise thorns or branched spines which are regularly disposed. Eegardiug this disposition we may distinguish three cases : A, the spines lie in the sagittal plane and form a single row, arising from the median edge ; B, the spines lie on both sides of the latter and form two parallel rows, arising from the two lateral edges ; C, the spines represent a com- bination of A and B, and are disposed in three rows, two paired rows arising from the two lateral edges, and an odd middle row between them, arising from the median edge. The spines are simple, without branches, in Archicircus and Zygocircus ; more or less branched in Lithocircus and Dendrocircus. The branches are often richly ramified or arborescent, and exhibit great variety in size, special form, and direction (compare PI. 81). The number and disposition of the spines or groups of spines are usually constant, and may be employed in the further progress of our knowledge, to distinguish a number of genera and subgenera. Very commonly (perhaps in the majority of the Stephanida) we find six groups of spines, an apical group on the upper rod of the sagittal ring, a basal group on the lower rod (on the porochora of the central cajDsule), two ventral groups on the anterior rod, and two dorsal groups on the posterior rod. In other species we find four or eight groups instead of six, and sometimes a larger number. The most important of these apophyses of the ring are the basal spines, arising from its basal pole, where the porochora of the central capsule rests upon it. They are often much larger and more branched than the other spines, and attain a peculiar morphological value in the small subfamily Cortinida. Here we find three or four regularly disposed " basal spines," which may be compared to the typical " basal feet" of the Cyrtellaria, appearing in the majority of Spyroideaand Cyrtoidea. Cortina, one of the most important Nassellaria, bears three typical divergent feet on the base of the simple ring, two paired anterior or " pectoral feet," and an odd posterior or " caudal foot." The latter appears as a direct basal prolonga- tion of the dorsal rod of the ring, and is opposed to an upper prolongation of the same, which corresponds to the "apical horn" of the Cyrtellaria (PL 97, figs. 1-3). As already explained above, these three basal feet of Cortina possess the highest phylo- genetic value, since they may also be compared with the three primary radial spines of the Plectoidea, and so connect the Cyrtellaria and the Plectellaria. Stephaniiim di9"ers from Cortina in the possession of four basal feet, an odd anterior or " sternal foot" being added to the three typical feet of the latter (PI. 92, figs. 20, 21). Some forms of Plectoidea (Plagoniscus, Plectaniscus, &c.) seem to be nearly related to these Cortinida, and may be easily transformed into them by development of a complete ring, embracing the central capsule. They seem to demonstrate the near affinity of all these triradiate Nassellakia (PI. 91, figs. 4, 5, 9, lO). 940 THE VOYAGE OF H.M.S. CHALLENGER. Syjiojisis of the Genera of Stephanida. L Subfamily Lithocircida. TSo typical basal feet on • the base of the ring (no cortinar feet). II. Subfamily Cortinida. Three or four typical basal feet on the ring (cortinar feet). Eing diphragmatic or amphithect; dorsal and ventral bow equal. King smooth or thorny, with- out branched spines. Ring armed with branched spines, f Eing smooth or thorny, with- Eing dipleuric, bilateral ; | out branched spines, dorsal and ventral bow - different. Eing armed with branched spines. Three basal feet (and an / One caudal and two lateral apical horn). ( feet, Four basal feet (and an ( Two sagittal and two lateral apical horn). ( feet, 401. Archidrcus. 402. Lithocircus. 403. ZygocirciLS. 404. Dendrocircus. 405. Cortina. 406. Stephanium. Subfamily 1. Lithocircida, Haeckel. Definition. — S tephanida without typical basal feet or cortuiar feet. Genus 401. Archidrcus^' n. gen. Definition. — S tephanida with a simple amphithect or diphragmatic ring, smooth or thorny, without branched spines and basal feet. The genus Archidrcus is the most primitive and simplest form of all S t e p h o i d e a, and probably the common ancestral form, not only of this suborder, but of the greater number of all Nassellaria (compare above, p. 893). The skeleton consists only of a quite simple sagittal ring, in which commonly a slight difference of both poles of the main axis (basal and apical pole) is visible, but no diflference between the dorsal and the ventral bow of the ring. In my Prodromus (1881, p. 447) the species oi Archidrcus were disposed partly in the subgenus Monostejihus, partly in the genus Lithocircus. Subgenus 1. Monostephus, Haeckel, 1881, Prodromus, j). 447. Definition. — Ring circular, elliptical, or ovate, without prominent corners. 1. Archidrcus princeps, n. sp. Gate circular. Eing circular, smooth, its transverse section also circular. The simplest form of all S 1 6 p h oi d e a. Dimemions. — Diameter of the gate 0-05 to Q-QS ; thickness of the ring 0-006 to O'OOS. Edbitat. — Central Pacific, Stations 265 to 274, depth 2350 to 2925 fathoms. 1 ylrc/ticifcus = Primordial ring; ifx'i "■'Z'^og. RErOET 0^ THE RADIOLARIA. 941 2. Archicircus monostephus, n. sp. (PI. 83, fig. 17). Grate circular. Ring circular, with three elegantly denticulate edges (one outer median and two lateral edges). Transverse section of the ring triangular. Dimensions. — Diameter of the gate 0-06 to 008 ; thickness of the ring O'Ol to 0008. Haiitat. — Central Pacific, Station 274, depth 2750 fathoms. 3. Archicircus ellipsis, n. sp. Gate elliptical. Eing eUiptical, on the inner margin smooth, on the outer margin with fifteen to twenty equal, short, simple, or slightly forked thorns. Transverse section ovate. Dirnensions. — Diameter of the gate 0-05 to 0-09 ; thickness of the ring O'Ol to 0 0 14. EahUai. — ^Western Tropical Pacific, Station 225, depth 4475 fathoms ; also fossil in Barbados. 4. Archicircus ovalis, n. sp. Gate ovate. Eing eUiptical, smooth, with three prominent, slightly distorted edges, without thorns ; in the transverse section triangular. Dimensions. — Diameter of the gate O'OS to 0'12 ; thickness of the ring 0-006 to 0-009. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. 5. Archicircus mtpnopylus, n. sp. Gate ovate. Eing ovate, thorny, with three distorted edges, in the transverse section triangular ; surface covered with numerous simple small thorns arising from the three edges. Dimensions. — Diameter of the gate O'l to 0-15 ; thickness of the ring O'Ol to 0-012. Habitat. — Indian Ocean (iladagascar), Eabbe, surface. Subgenus 2. Archistep>hus, Haeckel. Definition. — Ring polygonal, with four to six or more prominent comers (and commonly with simple spines arising from the corners). 6. Archicircus quadratus, n. sp. Gate square. Eing square, with three edges and four short simple pyramidal spines on the four comers, opposite in pairs in two perpendicular diameters. Transverse section triangular. Dimensions. — Diameter of the gate 0-08 ; thickness of the ring 0-008. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 942 THE VOYAGE OF H.M.S. CHALLENGER. 7. Archicircus rhombus, n. sp. (PL 81, fig. 7). Gate rhombic. Eing rhombic, with four promineut edges and four pairs of short, divergent, pyramidal spines on the four corners, arising from the lateral edges of the four rods, about as long as the radius of the gate. Dimensions. — Diameter of the gate 0-04 to O'OS; thickness of the ring 0"007 to O'Ol. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 8. Archicircus duodenus, n. sp. Gate square or rhombic. Eing rhombic, with three prominent edges and twelve stout and straight pyramidal spines, about as long as the radius of the gate. In each of the four corners are three divergent spines, arising fi-om the three edges of each two meeting rods. Dimensions. — Diameter of the gate 0'08 ; thickness of the ring 0'012. Habitat. — North Atlantic, surface (Eabbe). 9. Archicircus primordialis, n. sp. (PI. 81, fig. 1). Gate ovate. Eiag hexagonal, with three prominent edges and six short pyramidal thorns at the six corners; the basal thorn is either simple or forked. Dimensions. — Diameter of the gate 0'07 ; thickness of the ring O'Ol to 0*015. Habitat. — Central Pacific, Stations 265 to 274, depth 2350 to 2925 fathoms. 10. Archicircus hexacanthus, n. sp. (PI. 81, fig. 4). Gate subregular, hexagonal. Eing hexagonal, with three sharp edges and six equal radial pyramidal spines, arising from the six corners and placed in the plane of the ring, about as long as the diameter of the gate. Dimensiom. — Diameter of the gate 0'05 to 0-07 ; thickness of the ring O'Ol. Habitat. — South Pacific, Station 295, depth 1500 fathoms. 11. Archicircus hertwigii, Haeckel. Lithocircus annularis, R. Hertwig {nan J. Miiller), 1879, Organismus der Radiol., p. 69. Taf. vii. fig. 5. Gate hexagonal, with prolonged main axis. Eing hexagonal, with two prominent edges and six pairs of equal, short, conical spines, arising from the two edges of the six rods at the six corners and divergent on each side of the plane of the ring. The basal spine-pau- is doubled, therefore there are in all fourteen spines. Dimensions. — Diameter of the gate 0-05 to 0-07 ; thickness of the ring 0-005 to 0-006. Habitat. — Mediterranean (Messina), Hertwig, surface. REPORT ON THE RADIOLARIA. 943 12. Archicircxis triglyphus, n. sp. Gate ovate. Eiug hexagonal, with three prominent edges and twenty-two to twenty-four simple curved spines, arising from the six corners and about as long as the diameter of the gate. In the basal corner arise six to nine larger spines, protecting the basal pole of the central capsule. From each of the five other corners arise three spines, diverging from the three edges. DimeTisions. — Diameter of the gate 0'07 to 0-11 ; thickness of the ring O'OOS to O'Oll. HahUat. — Central Pacific, Station 268, depth 2900 fathoms. 13. Archicircus sexangularis, n. sp. (PL 81, fig. 12). Gate hexagonal or subcircular. Eing hexagonal, with two sharp prominent edges and six pairs of divergent spines, about as long as the radius of the gate, and arising from the two edges at the six corners. The two apical and the two basal spines are simple and conical, whilst the eight other spiaes, arising in pau's from the two dorsal and the two ventral corners, are slightly forked. Dimensions. — Diameter of the gate 0'06 to 0-08 ; thickness of the ring O^Ol to O'Olo. EaUtat- — South Atlantic, Station 332, depth 2200 fathoms. Genus 402. Lithocircus,^ J. Miiller, 1856, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 484. Definition. — S t e p h a n i d a with a simple amphithect or dipkragmatic ring, armed witk branched spines, without typical basal feet. Tlie genus Lithocircus is the oldest known form of all S t e p h o i d e a, founded by J. Miiller in 1856 for his Lithocircus annularis, the first species of this suborder described. We retain here this cosmopolitan form as the typical representative of the genus, which differs from the preceding Archicircus, its ancestral form, in the develop- ment of branched radial spines. 1. Lithocircus annularis, J. Miiller. Lithocircus annularis, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 29, Taf. i. fig. 1. Gate circiUar. Eing circular, with four forked or simply branched spines, opposite in pairs in two diameters, perpendicular one to the other. Spines with slender curved fork-branches, about as long as the diameter of the gate. The specimen figured by J. Miiller bears a supernumerary fifth spine ; numerous other specimens observed by me exhibited a regular cross of four spines. JDimensions. — Diameter of the gate 0"1 to 015; length of the spines O'Ol to 0'18. Hahitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface. 1 Lithocircus = 'R\ng of silex ; x/^of, x/jxoj. 944 THE VOYAGE OF H.M.S. CHALLENGER. 2. Lithocircus quadricornis, n. sp. (PI. 81, fig. 9). Gate square. Eing square, with three sharp denticulate edges, and four large buuehes of richly branched spines on the four corners. In each corner arise three curved spines, about as long as the diameter of the ring ; their numerous irregular branches are forked and curved like the antlers of deer. Dimensions. — Diameter of the gate 0'07 ; length of the horns 0-06 to 0'09. Habitat. — South Pacific, Station 300, depth 1375 fathoms. 3. Lithocircus decimalis, n. sp. (PI. 81, fig. 15). Gate elliptical. Eing pentagonal, with three prominent edges and five pairs of branched spines on the five corners. In each corner arise two or three curved spines, about as long as the radius of the gate, each with two to four forked branches. Dimensions. — Diameter of the gate 0'08 ; length of the spines 0'03 to 0"05. Habitat. — North Atlantic, Station 354, surface. 4. Lithocircus hexahlastus, n. sp. (PL 81, fig. 17). Gate elliptical. Eing hexagonal, with three prominent edges and six pairs of branched spines, arising from the six corners. Each of the twelve spines is short and stout, only half as long as the radius of the gate, and bears a bunch of ten to twenty short, densely aggregated, conical or horn-like curved branches. Dimensions. — Diameter of the gate O'l ; length of the spines 0'02 to 0'03. Habitat.— Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms. 5. Lithocircus crambessa, n. sp. (PL 81, fig. 6). Gate elliptical or subcircular. Eing hexagonal, with three wing-shaped distorted edges and six groups of branched spines, arising from the six corners. In each corner arise three short and stout divergent spines, each bearing a bunch of numerous short roundish branches like a cauliflower, scarcely as long as the thickness of the ring. Dimensions. — Diameter of the ring 01 to 0'12, length of the spines O'Ol to 0'02. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 6. Lithocircus tarandus, n. sp. (PL 92, fig. 19). Gate circular. Eing hexagonal, with three sharp edges and six pairs of large branched spines, arising from the flat lateral edges on the six corners. Each of the twelve spines is horizontally expanded, longer than the diameter of the ring and dichtomously forked like the antlers of a rein- REPORT ON THE RADIOLARIA. 945 deer. If the lateral ends of the branches of this species become united in the frontal plane, we get 3Iicrocubus, the four upper spines forming the mitral ring, the four middle the equatorial ring, and the four lower the basal ring. Dimensions. — Diameter of the gate 0-08 ; length of the spines 0'09. Habitat. — Centi-al Pacific, Station 272, surface. 7. Lithocircus furcatus, u. sp. Gate ovate. Eing ovate, with three sharp prominent edges. The two lateral edges are smootla, The mechan edge (in the sagittal plane) bears sixteen to twenty forked spines (commonly eight dorsal, eight ventral, and four basal). All the spmes are of nearly equal size, slightly curved, and about half as long as the short sagittal axis of the ring. Dimensions. — Diameter of the gate 0'08 to 0'12 ; length of the spines 0"03 to 0'04. Habitat. — North Pacific, Station 253, depth 3125 fathoms. 8. Lithocircus magnijiciis, n. sp. (PL 81, fig. 16). Gate ovate or nearly elliptical. Ring ovate, with three prominent edges, and numerous richly branched spines arising from the three edges. The specimen figured, which I observed living in the Mediterranean, exhibited eight bunches of larger spines, three dorsal, three ventral, one apical, and one basal bunch ; the latter much larger than the seven others. Each bunch was composed of two to four larger and numerous smaller spines, their branches curved and forked. The ovate purple central capsule, with a distinct podoconus, fiUed more than the half of the gate. Dimensions. — Diameter of the gate 01 to 013 ; length of the spines 0'05 to 015. Habitat. — Mediterranean (Portofino, 1880), Atlantic (Canary Islands), Station 351, surface. Genus 403. Zygocircus,^ Biitschli, 1882, Zeitschr. f. wiss. ZooL, vol. xxxvi. p. 496. Definition. — -Steplianida with a simple dipleuric or bilateral ring, smooth or thorny, without branched spines and basal feet. The genus Zygocircus and the following Dendrocircus differ from the two preceding older genera in the bilaterally symmetrical or dipleuric form of the sagittal ring. Whilst in Archicircus and Lithocircus the two sagittal halves or bows of the ring, the dorsal and ventral bow, are equal (therefore the fundamental form amphithect or diphrag- matic), here both bows become distinctly different ; the dorsal bow is constantly more straight (often vertical), the ventral bow more convex (obliquely ascending). This dipleuric differentiation is most important, as it is transmitted to the greater number of Nassellaria by heredity. ' Zygodmts = Yoked or symmetrical ring ; i^vyou, ki'^xo;. (zOOL. CHALL. EXP. — PART XL. — 1886.) Rr 119 946 THE VOYAGE OF H.M.S. CHALLENGER. 1. Zygocircus sagittalis, n. sp. Gate ovate. Eing half ovate or nearly triangular, with three curved edges and three prominent corners, one apical and two basal protuberances. Dorsal rod vertical, twice as long as the horizontal basal rod. Ventral rod convexly curved. Dimensions. — Diameter of the gate 0-05 to 0-07 ; height of the tubercles 0-01 to 0-015. Habitat. — Central Pacific, Stations 265 to 268, depth 2900 fathoms. 2. Zygocirmis trigonus, n. sp. Gate triangular. Eing triangular, with three curved edges and three prominent corners, which are prolonged into nine divergent conical spines ; three spines arising from the three edges of each corner. Dorsal rod vertical ; ventral and basal rods curved and convergent. Dimensions. — Diameter of the gate Oil to 013 ; length of the spines O'Ol to 0'015. Habitat. — Indian Ocean, Sunda Archipelago (Eabbe), surface. 3. Zygocircus tetragonus, n. sp. Gate ovate. Eing quadrangular, without edges, with four simple conical spines of different sizes ; one smaller apical, one larger basal, and two equatorial spines of middle size (one dorsal and one ventral). Dorsal and ventral rod curved. Dimensions. — Diameter of the gate O'Ol to 0'06 ; length of the spines O'OIS to 0'026. Habitat. — Tropical Atlantic, Station 338, depth 1990 fathoms. 4. Zygocircus rhomhicus, n. sp. Gate rhombic. Eing rhombic, with three prominent edges, and eight short conical curved spines arising from the lateral edges at the four corners of the rhombus. The basal and ventral spine are larger than the apical and dorsal spine ; the ventral rod is more curved (with smaller angle) than the shorter dorsal rod. The medial edge of the ring is smooth, without spines. Dimensions. — Diameter of the gate 0'08 ; length of spines 0'02 to 0'04. Habitat. — South Atlantic, Station 335, depth 1425 fathoms. 5. Zygocircus pentagomis, n. sp. (PI. 81, fig. 8). Gate roundish pentagonal. Eing very thick (about as thick as the radius of the gate), irregularly pentagonal, with prominent sagittal edge. On both sides of the latter arise at the five corners five pairs of short simple irregularly curved spines. The four ventral spines are larger than the four dorsal, and the two basal spines larger than the eight former, forked. (In fig. 8 the basal spines are turned upwards.) Dimensions. — Diameter of the gate 0-07 ; length of the spines 0-04 to 0-06. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. f REPORT ON THE RADIOLARIA. 947 6. Zygocircus hexagonus, n. sp. Gate irregularly hexagonal. Ring obliquely hexagonal, thick, without edges, with six short and stout conical spines on the six corners. The two spines of the curved ventral rod are longer than the two spines of the straight dorsal rod. The apical spine is smaller and the basal spine larger than the four others. DinieimoTis. — Diameter of the gate 0"07 to 0"09 ; length of the spines O'Ol to O^OS. Habitat. — North Pacific, Station 241, depth 2300 fathoms. 7. Zygocircus triquetrus, n. sp. (PI. 81, fig. 3). Gate obliquely ovate. Pang obliquely hexagonal, with three sharp edges and three short conical spines on each of the six corners. Therefore each hexagonal edge bears six short radial spines of equal size. Dimensions. — Diameter of the gate 0'04 to 0'08 ; length of the spines O'Ol to 0'02. Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface. 8, Zygocircus dodecanthus, n. sp. Gate semicircular. Eing semicircular or irregularly hexagonal, without edges, with twelve short blunt spines, arising in pairs from the six corners ; two apical, two basal, and between them two equatorial corners. Three pairs of spines remain on the straight dorsal rod, three on the curved ventral rod. Dimensions. — Diameter of the gate 0-04 to 0-06 ; length of the spines O'Ol to 0'02. Habitat. — Central Pacific, Stations 263 to 268 ; depth 2650 to 2900 fathoms. 9. Zygocircus acacia, n. sp. (PL 81, fig. 5). Gate obliquely ovate. Eing semi-ovate, with straight dorsal and curved ventral rod, partly with distorted edges. Six bunches of numerous short and straight conical spines arise from the ring, one larger bunch (often trifid) from the apex, two smaller bunches from the dorsal, two from the ventral rod, and one very large bunch from the base. The six bunches are often more sej^arated, smaller, and the spines shorter than in the figured specimen, which passes over into Derulrocircus. Dimensions. — Diameter of the gate 012 to 0"16 ; length of the spines, 0-01 to 0'07. Haiitat. — Central Pacific, Station 266, depth 2750 fathoms. 10. Zygocircus polygonus, n. sf). (PI. 81, fig. 2). Gate irregularly roundish or ovate. Eing irregularly pol3-gonal or sometimes nearly circular, without edges, armed with a single series of ten to fifteen short pyramidal spines, which are irregularly 948 THE VOYAGE OF H.M.S. CHALLENGEE. disposed in the sagittal plane. The ventral rod is strongly curved, often semicircular, the dorsal rod less curved or nearly straight. Dimensions. — Diameter of the gate 0'05 to 0'07 ; length of the spines 0-004 to 0'02, Hcibitat. — Cosmopolitan — Atlantic, Pacific ; also fossil in Barbados. 11. Zijgocircus hiitschlii, n. sp. Zygocircits produdus, Biitschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 497. Gate obliquely ovate. Eing irregularly roundisli, semi-ovate or ovate, with interrupted and distorted edges, and with a large number (ten to twenty or more) of simple, irregularly formed and asymmetrically disposed spines ; commonly some larger spines at the base. Dimensions. — Diameter of the gate O'Oo to 0"09 ; length of the spines 0'005 to 0'02. Habitat. — Fossil in Barbados. 12. Zijgoeircus productus, Biitsclili. Zygocirais produdus, Biitschli, 1882, Zeitschr. f. wiss. Zoo]., vol. xxxvii p. 496. Liithocircus produdus, R. Hertwig, 1879, Organismus d. Eadiol., p. 69, Taf. vii. fig. 4. Gate oblicpiely ovate. Eing obliquely ovate, with three complete prominent edges and with numerous (ten to twenty or more) siniple, short conical spines, arising in three series from the three edges ; commonly some smaller spines at the base. Dimensions. — Diameter of the gate 01 to 02 ; length of the spines O'OOS to 0'02. Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface. Genus 404. Dendrocircus,^ Haeckel, 1881, Prodromus, p. 447. Defiyiition. — S tephanida with a simple dipleuric or bilateral ring, armed with branched spines, without typical basal feet. The genus Dendrocircus has the same dipleuric or bilaterally symmetrical form of the sagittal ring as its ancestral genus Zyfjocircus. It differs from the latter in the development of branched radial spines, and therefore bears to it the same relation as the amphithect Lithocircus does to the simpler Archicircus. 1. Dendrocircus quad.rangidus, n. sp. Gate irregularly quadrangular or nearly semicircular. Eing quadrangular, edgeless, with four unequal sides ; ventral rod more curved and with longer sides than the dorsal rod. From the four edges arise four strong, irregularly branched spines, about as long as the diameter of the gate, ' De»droarcMS= Ring bearing trees ; BsvSgov, Aijxoj. REPORT ON THE RADIOLARIA. 949 with curved branches ; the ventral and basal spines larger than the dorsal and apical spines. Similar to Lithocircus g/uadricomis (PI. 81, fig. 9), but less branched, and with a striking difference between the shorter dorsal and the longer ventral rod. Dimensions. — Diameter of the gate 0'04 to 0'06 ; length of the spines 0"05 to 0'07. Habitat. — North Pacific, Station 256, depth 2950 fathoms. 2. Dendrocircus dodecarrhiza, n. sp. Gate obliquely ovate. Ring irregularly quadrangular, with three prominent edges. From the latter arise at the four corners twelve divergent, irregularly branched spines (three in each corner), about as long as the radius of the gate, with curved branches ; the three basal spines larger than the nine others. Dimensions. — Diameter of the gate O^OS to O'l ; length of the spines 0'0-i to 006. Habitat. — Indian Ocean (Maldive Islands), surface (Haeckel). 3. Dendrocircus dodecancistra, n. sp. (PI. 81, fig. 11). Gate obliquely ovate or nearly elliptical. King irregularly ovate, with three distorted edges and six paii's of branched spines. The two ventral paii's are much more distant than the two dorsal pairs, the ventral rod being longer and more curved than the dorsal rod. All twelve spines are of nearly equal size, are more or less curved, about as long as the diameter of the gate, and each, bears six to twelve irregular short branches at the end. Dimensions. — Diameter of the gate 0-07 to 0'08 ; length of the spines 0'05 to 0'08. Habitat. — Tropical Atlantic, Station 342, depth 1445 fathoms. 4. Dendrocircus arborescens, n. sp. (PI. 81, fig. 10). Gate irregularly roundish or nearly circular. Ring of the same form, with slight edges and six pairs of elegant arborescent spines (one apical, two dorsal, two ventral, and one basal pair) ; the three latter somewhat larger than the three former. Each tree is larger than the ring, in the basal half simple, in the distal half forked, each fork-branch with numerous dichotomous terminal branches. Dimensions. — Diameter of the gate 0'06 to 0'G8 ; length of the spines 012 to 0'15. Habitat. — Central Pacific, Stations 266 to 274, surface. 5. Dendrocircus elegans, n. sp. (PI. 81, fig. 13). Gate irregularly ovate. Ping thick, ovate, with three denticulate edges and six bunches of stout, branched and spinulate, curved spines. The four ventral spines are more distant than the four dorsal, the ventral rod being more curved than the dorsal. The latter bears above the two apical spines. The two basal spines are much larger, deeply forked ; their four fork -branches may be compared to the four basal feet of Stcphanium. Dimensions. — Diameter of the ring 0'09 to Oil; length of the spines 0"03 to 0"06. Hahitat. — Central Pacific, Station 274, depth 2750 fathoms. 950 THE VOYAGE OF H.M.S. CHALLENGER. 6. Dendrocircus harbadensis, n. sp. Gate irregularly ovate or nearly semicircular. Eiiig of the same obUque form, thick, with interrupted and distorted edges, armed with eight to twelve larger iiTegularly formed and branched acute spines; between them numerous conical smaUer spines. This common species is very polymorphous and variable. X>ime?mo»is.— Diameter of the ring 0-05 to 0-08 ; length of the spines 0-005 to 0-02. Habitat. — Fossil in Barbados. 7. Dendrocircus stalactites, n. sp. (PL 81, fig. 14). Gate obliquely ovate. Ring irregularly ovate or roundish, very thick, vrithout edges, armed with numerous (eight to twelve or more) short and stout branches, which are shorter than the diameter of the oate, irregularly disposed and branched, with very numerous clustered blunt ramules. Dimensions. — Diameter of the gate G-07 to 0-09 ; length of the spines 0-02 to 0-06. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. Subfamily 2. Cortinida, Haeckel. Definition. — S tephanida with typical basal feet (or cortinar feet). Genus 405. Cortina,^ n. gen. Definition. — S tephanida with a simple dipleuric or bilateral ring, bearing at the base three divergent feet (one odd caudal and two paired lateral feet). The genus Cortina and the following Stephatiium represent together the small but very important group of Cortinida, differing from the simple Lithocircida in the possession of three typical basal feet, which are transmitted to the majority of the Nassellaria by heredity, and produce their peculiar trii-adial structure. They appear therefore as a combination of the simple ring [Zygocircus) with three basal feet {Plagonium). One of these three divergent feet is the odd caudal foot, op]30site to the apical horn ; the two others are the paired lateral or pectoral feet. (On the probable origin and the typical signification of Cortina compare above, pp. 891—894.) 1. Cortina tripus, n. sp, (PI. 83, fig. 9). ELng ovate, smooth, or with a few short thorns. Apical horn obUque, curved, simple, smooth, about as long as the sagittal axis of the ring. Feet divergent, curved, simple, smooth, about as 1 Cortina = Tripod. REPORT ON THE RADIOLARIA. 951 long as the horn ; the caudal foot shorter than the two pectoral feet. Very variable in fomi and size. Dimensions. — Height of the ring 0'06 to 0-09, breadth 0-04 to 006 ; length of the feet 0-05 to 01. Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific, surface and in various depths. 2. Cortina tyjms, n. sp. (PI. 97, fig. 1). Eing kidney-shaped or nearly semicircular, with revolnte vertical dorsal rod and strongly curved ventral rod ; both rods with two pairs of spine-bunches. Apical horn nearly straight, thorny, longer than the ring, directed a little obliquely backwards. Feet slightly curved, of equal length, two to three times as long as the ring ; each armed with few large bunches of curved spines, which are more developed in the caudal foot than in the two pectoral feet. Dimensions. — Height of the ring 014, breadth O-QS ; length of the feet 0'2 to 03. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 3. Cortina conifera, n. sp. Eing sulicircular, smooth. Apical horn and the three divergent feet of equal size and similar form, cylindrical, straight, about as long as the ring, at the distal end thickened, with a dimply cone (similar to Tripospyris conifera and Tripospyris eucolpa, PL 84, figs. 4, 7). Dimensions. — Height of the ring 0'08, breadth 0"06 ; length of the feet 0-09. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 4. Cortina furcata, n. sp. Eing elliptical, with three forked horizontal spines (one on the dorsal and two on the ventral rod). Apical horn and the three divergent feet of equal size, somewhat longer than the ring, slightly curved, in the distal half forked. Dimensio'os. — Height of the ring 0-07, breadth 0'05 ; length of the feet 0'09. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 5. Cortina dendroides, n. sp. Eing ovate, with six pairs of branched horizontal spines, three on the dorsal and three on the ventral rod. Apical horn very large, arborescent, about as long and as broad as the ring. Feet similar to the horn, also richly branched, of equal size. All the rods and their branches curved, with prominent distorted edges. Dimensions. — Height of the ring 013 to 017, breadth 01 to 012 ; length of the feet 0r5 to 0-2. Habitat. — Central Pacific, 'Stations 266 to 274, depth 2350 to 2925 fathoms. 952 THE VOYAGE OF H.M.S. CHALLENGER. 6. Cortina cervina, n. sp. (PL 92, fig. 21). Pdng ovate, with four pairs of forked horizontal spines (two dorsal and two ventral pairs) Apical horn straight and stout, as long as the ring, with trifid point. Three feet *qual, widely divergent, very large, branched like a deer's antler, with very numerous short and stout, curved and pointed branches. All rods and branches roundish, without edges. Dimensions. — Height of the ring 01, breadth 0-07 ; length of the feet 012 to 0-16. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. Genus 406. Stejihaniurn,^ n. gen. Definition. — S t e p h a n i d a with a simple dipleurie or bilateral ring, bearing at the liase four divergent feet (two sagittal and two lateral feet). The genus Stephanium differs from the preceding nearly allied Cortina in the production of four basal feet ; the new foot, missing in the latter, is the anterior or sternal foot. Therefore Stejihanium may be regarded as the archetype of all those Nassellaeia in which, on the base of the sagittal ring, there are developed four typical feet — two sagittal feet (the posterior caudal and anterior sternal foot) and two lateral feet (right and left). On the origin of Stejihanium compare above, p. 893, &c. 1. Stephanium quadrupes, n. sp. (PI. 92, fig. 20). Eing ovate, with three prominent dentate edges and a short pyramidal apical horn. Four feet aU of nearly equal size, about as long as the ring, also with three thorny edges, in the upper half divergent, in the lower convergent. Dimensions. — Height of the ring 012, breadth O^OS ; length of the feet Oil to 013. Hahitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Stephanium tetrapus, n. sp. Eing elliptical, without edges, thorny, with a stout, thorny apical horn of the same length. Four feet curved and irregularly branched, divergent, of different size. The two sagittal feet (the anterior sternal and posterior caudal) about as long as the ring. The two lateral feet (right aud left) nearly twice as long, more richly branched. Dimensions. — Height of the ring 016, breadth Oil ; length of the feet 015 to O'S. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 1 SUphanium=^va.&]l crown or garland ; aTtipaunju. REPORT ON THE RADIOLARIA. 953 Family XLIX. S e m a n t r d a, u. £am. Definition. — S tephoiclea with a single vertical ring (the primary sagittal ring), bearing on its base a horizontal ring (basal or cortiuar ring) with two to four or more basal gates (or cortinar pores). The family S e m a n t i d a differs from the preceding Stephanida in the development of a small horizontal ring on the base of the primary vertical sagittal ring. By the crossing of these two rings a small latticed basal plate is formed, with one or two pairs of pores ; rarely with a greater number of " basal pores." The production of this characteristic " basal plate " is of the greatest morphological importance, as the beginning of the numerous different lattice-formations, which are differentiated in the great majority of Nassellaria. In my Prodromus (1881, p. 446) I had enumerated the Semantida with three genera (Nos. 298 to 300) as a separate subfamily of the Dyostephida or " Stephoidea bianuularia," and characterised these " Dyostephanida " by the following definition : " Skeleto annulis duobus composito, qui in duobus planis invicem perpendicularibus jacent ; altero annulo (sagittali) verticali, altero (basali) horizoutali." As the names there given were already employed with another signification, and as the Zygostephauida (there united with the Dyostephanida) are more closely related to the Coronida, I now change the names, and propose to call the family Semantida, expressing by this term the typical similarity of the skeleton to a signet-ring (Semantis, Semantrum, Semantidium). At about the same time, some Stephoidea of this family were accurately described by Biitschli (1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 495, Taf. xxxii. figs. 6, 7, 8). He called them Ste2:)hanolithis, a name which Ehrenberg had em- ployed, not for complete shells of Eadiolaria, but for isolated parts of such, and for siliceous fragments of different skeletons, needles of Sponges, &e. The three species described by Biitschli represent three different genera of our Semantida, viz., Semantis spinescens (with two gates in the basal plate), Semantrum miilleri (with four gates), and Semantidium haeckelii (with six gates). He pointed out the great morpho- logical value of the fenestrated basal plate and its paired gates, as beginnings of numerous other Nassellakia. But his opinion, that in all S p y r 0 i d e a and C y r- t o i d e a, derived from these, two pau's of basal gates were constant, was erroneous, nor was the formation of the first pair naturally explained ; he supposed that the formation of the basal plate begins by develojament of an odd sagittal apophysis, arising from the base of the primary sagittal ring. But this odd sagittal apoi^hysis (" der unpaare mediane Kieselfortsatz cl", loc. cit., p. 497) is in reality not a primary (zool. CHALL. EXP. PART XL. — 18S6.) lir 120 954 THE VOYAGE OF H.M.S. CHALLENGEE. and essential part of the skeleton, but secondary and of little morphological value, absent in the majority of the Semantida and of the other Nassellaeia. We divide our famUy Semantida into two diiferent suljfamilies, which possibly possess a direct phylogenetic relation to the two subfamilies of Stephanida : — The Semantiscida have no typical feet, and have arisen directly from the Lithocircida ; the Cortiniscida, however, possess the three typical basal feet of Cortina, and may there- fore be derived directly from the Cortinida. Since these three cortinar feet are probably identical with the three primary radial rods of the P 1 e c t o i d e a, an imme- diate affinity also to these Nassellaeia is indicated. The Semantiscida, which do not possess these three basal cortinar feet, are the simpler forms of the family. The simplest of all, and perhaps the common ancestral form of the whole family, is Semcintis (PL 92, figs. 1, 2). It may be derived from Archicircus or Zygocircus by development of two pairs of horizontal apophyses on its base, around the porochora of the central capsule. The two rods of each side (right and left), becoming curved one towards the other, and meeting laterally, form a simple horizontal gate, and the two paired basal gates together, a horizontal ring or basal ring, to which the primary sagittal ring is pei'pendicular. In the next allied genus, Semantrum (PL 92, figs. 3—5), three pairs of horizontal apophyses are developed, and therefore two pairs of basal gates produced, an anterior and a posterior. In the third genus, Semantidium (PL 92, figs. 6, 7), three pau-s of basal pores or gates are visible, surrounded and separated by four pairs of horizontal apophyses, which arise from the base of the sagittal ring. Finally, in Clathrocircus (PL 92, figs. 8—10) the number of apophyses is much increased, and two parallel rows of pores are developed along the two sides of the sagittal ring. The basal plate or the "seal," developed from the base of the primary sagittal ring or " signet-ring," is therefore a horizontal ring, which becomes bisected by the latter, and exhibits either one pair of primary " basal gates " or two or three pau-s of these important basal pores, rarely more. Since these pores possess the greatest morphological value, and are probably everywhere homologous, we give to them and to the separating apophyses certain names, and call the anterior pair of gates, "jugular pores " (i in our figures, the pair I of Biitschli) ; the middle (usually the largest) pair, " cardinal pores " (k in our figures, the pair II of Biitschli), and the posterior, smaller pair, " cervical pores," l. The typical pairs of rods, l:)y the union of which these basal pores arise, are the following : — (l) the clavicular or furcular rods,/, the first pair (rods el of Biitschli), (2) the coracal rods, e, between the jugular and cardinal pores (rods e of Biitschli), (3) the scapular rods, g, between the cardinal and cervical pores (rods e2 of Biitschli), (4) the cervical rods, the fourth pair of apophyses, the most posterior, /i. Biitschli supposes that the topographical succession of the three typical j)airs of basal pores is also the chronological succession, the jugular being formed first, the EEPORT ON THE RADIOLARIA. 955 cardinal second, and the cervical pores thiixl ; but it seems that this succession is often altered, and that the cardinal pores (the largest), appear first, the jugular pores (in front of them) second, and the cervical pores third (or perhaps sometimes in the inverse succession). The Cortiniscida, the second subfamily of Semantida, differ from the preceding Semantiscida in the possession of three typical basal feet, which are probably inherited from the Cortinida, and perhaps indirectly from the Plagonida (Plagoniscus). The simplest and the most important form of this second family is Cortiniscus (PI. 92, figs. 11—13), differing from its probable ancestral form, Cortina^ in the development of a basal ring, produced by horizontal union of the basal apophyses. The three typical feet are the same as in all triradiate Nassellaeia, two paired pectoral feet {p^, p^) diverging on the anterior base of the sagittal ring, whilst the odd caudal foot (c) lies on its posterior base in the sagittal plane and appears as a basal prolongation of the dorsal rod of the sagittal ring ; the upper part of the dorsal rod is usually prolonged into an ascending apical horn. In Stephaniscus (PL 92, figs. 14, 15) four basal feet are visible, an anterior or sternal foot (z) being added as a prolongation of the basal rod of the ring, opposite to the caudal foot. Finally, Semantiscus (PI. 92, figs. 16—18) is distinguished by the possession of six divergent basal feet, probably identical with those of all six -radiate Nassellaeia ; three of these may be regarded as primary and per- radial, the odd caudal and the paired pectoral feet; the three other intercalated as secondary or interradial feet, the odd sternal (z) and the paired tergal feet {ti, ^u). The basal plate of these Cortiniscida exhibits the same important differences as in the preceding Semantiscida, either one, or two, or three pairs of basal gates being developed. But there occur also in some species (mainly in Cortiniscus) only three basal gates, an odd anterior (between the two pectoral feet and a connecting horizontal bar), and two paired posterior (between the two pectoral and the odd caudal foot). It requires further accurate researches to solve the important problem, what the true homologies of these typical basal pores and the separating bars ai'e in the different genera of Semantida. In Semantiscus there are three pairs of basal pores in the horizontal seal, correspond- ing to those of Semantidium, and the radial rods or bai-s between these are the basal parts of the six radial feet ; therefore the odd caudal foot (?) seems to be the posterior, and the odd sternal foot (2) the anterior prolongation of the basal part of the primary sagittal ring; the two paired anterior or pectoral feet (j).^, p ) the prolongations of the coracal rods (e) and the two paired posterior or tergal feet (t^, ?j^), the prolongations of the scapular rods (g). But it is not yet certain whether these six radial feet and the separating gates of the basal plate are all the same and truly homologous in all six- radiate Nassellaeia. In eveiy case the comparative study of the Semantida is of the highest value for the accurate knowledge of the Monopylea, 956 THE VOYAGE OF H.M.S. CHALLENGER. Synopsis of the Genera of Semantida. ' Two basal pores, . I. Subfamily Semantiscida. Basal ring without typical, regularly disposed basal feet (no cortinar feet). IL Subfamily CortLniscida. Basal ring wtli typical, - regularly disposed basal feet (cortinar feet). Only two, four, or six basal pores (no dorsal and - ventral pores). Four basal pores, . Six basal pores, Besides four basal pores, also apical pores or dorsal and ventral pores along the whole ring, Three basal feet. Four basal feet. Six basal feet. { One odd caudal foot and two paired lateral feet, Two sagittal and two latera or pectoral feet, Two sagittal, two pectoral and two tergal feet. 407. Semantis. 408. Semantrum. 409. Semantidium. 410. Clath rocireus. 411. Cortiniseus. 412. Stephaniscus. 413. Semantiscus. Subfamily 1. Semantiscida, Haeckel. Definition. — S emantida without typical basal feet or cortinar feet. Genus 407. Semantis, n. gen. Definition. — S emantida with two basal pores (or jugular pores), without typical basal feet. The genus Semantis, the most primitive and the oldest of the Semantida, is of the greatest morphological interest, as the first form of Stephoidea which produces gates or pores by communicating branches, and therefore the probable ancestral form not only of this family, but of the greater number of all S t e p h o i d e a, and perhaps even of all Spyroidea and C y r t o i d e a. Semantis arises from Archicircus by the pro- duction of two pairs of lateral branches from the basdar rod of the sagittal ring, one anterior pair of clavicular rods, and one posterior pair of coracal rods. By junction of the cla\'icular and coracal rod on each .side arises a left and a right pore, the "jugular pore or jugular gate." 1. Semantis hiforis, n. sp. (PI. 92, fig. 2). Sagittal ring obliquely ovate, nearly trapezoidal, with six pairs of short mammillated knobs or branches ; dorsal rod straight, vertical, with two pairs of knobs, ventral rod strongly convex, also with ' iSe7rianiw= Signet-ring ; S'em(Mi{trfMim= Small signet-ring; a^imuTihiou. REPORT ON THE RADIOLARIA. 061 sagittal iiair, one posterior and one anterior). All six gates of the basal plate triangular, the jugular and cervical a little smaller than the cardinal gates. Bimcnsioihs. — Height of the sagittal ring 0"1, breadth 0'07. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 3. Semantidium haeckelii, Biitschli. Stephanolithis Haeckelii, Biitschli, 1882, Zeitschr. f. wiss. Zoo!., vol. xxxvL pp. 499, 538, Taf. xxxii. figs. 6a, &!). Sagittal ring elliptical, with three pairs of short horizontal branched spines, one apical and two equatorial pairs (one dorsal and one ventral). Basal ring roundish hexagonal, with numerous short thorns on the margin. Jugular pores ovate, about half as broad as the ovate cardinal pores and twice as broad as the small cer\'ical pores. Bimensioiis. — Height of the sagittal ring 0'08, breadth 0-06. Habitat. — Fossil in Barbados. 4. Semantidium signatorium, n. sp. (PL 92, fig. 7). Sagittal ring semicircular, thorny ; basal ring pentagonal, with short spines on the margin and five stronger thorny spines on the five corners. Jugular pores ovate, smaller than the triangular cervical pores. Cardinal pores two to three times as large as each of the former, pentagonal. Dimensions. — Height of the sagittal ring 0-08, breadth 0"12. Habitat. — North Pacific, Station 241, depth 2300 fathoms. Genus 410. Clathrocircus,^ Haeckel, 1881, Prodromus, p. 447. Definition. — Semantida with a variable number of pores on the apical and the basal part of the ring, symmetrically arranged, without typical basal feet. The genus Clathrocircus comprises those Semantida in which the sagittal ring bears not only basal pores (as in the three preceding genera) but also apical pores (on the opposite pole of the main axis), or a variable number of pores along the whole ring. All these pores are sjrmmetrically arranged in pairs. In the simplest form there are only two apical pores opposite to four basal pores, whilst in the highest state of development the w^hole ring bears two complete circles of pores. At both poles of the transverse axis two large lateral gates remain open. If these become closed by lattice-work, Clathrocircus passes over into Dictyospyris. ' CTaffiroa>cus = Lattice-ring; xKiiipoy, ki'^ko;. (ZOOL. CHALL. EXP. — PAET XL. — 1886.) Er 121 962 THE VOYAGE OF H.M.S. CHALLENGER. 1. Clathrocircus hexaporus, n. sp. Sagittal ring circular, smooth, with three pairs of pores (one apical and two basal). The two apical pores are triangular, with two lateral spines, and correspond to the two mitral gates of the Tympanida. The four basal pores form a hexagonal basal plate, with six lateral spines, and correspond to the four basal pores of Semantrum ; the two jugular are pear-shaped, and half as broad as the two triangular cardinal pores. Dimensions. — Height of the sagittal ring 0'08, breadth 0"06. Habitat. — Cosmopolitan ; Atlantic, Pacific, many Stations, surface. 2. Clathrocircus octoporus, n. sp. Sagittal ring elHptical, smooth, with four pairs of pores (two apical and two basal). The four apical pores are of nearly equal size, subcircular, and form a regular cross around the apical pole. The four basal pores are ovate, and form a quadrangular plate, armed with marginal thorns ; the two jugular pores are somewhat smaller than the two cardinal pores. Dimensions. — Height of the sagittal ring Oil, breadth 0'08. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 3. Clathrocircus decaporus, n. sp. Sagittal ring ovate, thorny, with five paii's of pores (two apical and three basal). The four apical pores are roundish and form a cross. The six basal pores are triangular and form a hexagonal plate with thorny margin ; the two jugular pores are somewhat larger than the two cervical, and half as broad as the two cardinal pores. Dimensions. — Height of the sagittal ring 0'09, breadth 0'07. Habitat. — North Pacific, Station 256, depth 2950 fathoms. 4. Clathrocircus stapedius, n. sp. (PL 92, fig. 8). Sagittal ring ovate, smooth, with six pairs of pores (two apical and four basal). The four apical pores are of nearly equal size and form a quadrangular mitral plate with two large lateral horns. The eight basal pores are of very different size (the four central far larger than the two anterior and the two posterior), and form a hexagonal basal plate, also with two large lateral horns. The four branched lateral horns (two upper and two lower) form together an incomplete frontal ring. Dimensions. — Height of the sagittal ring 01, breadth 0"08. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. REPORT ON THE RADIOLARIA. 963 5. Clathrocircus dictyospyris, n. sp. (PL 92, fig. 9). Sagittal ring ovate, thorny, with eight pau's of pores. The four apical and the four basal pores are elliptical and far larger than the four dorsal and the four ventral pores. Eesembles a Dictyospyris with open lateral gates. Dimensicms. — Height of the sagittal ring 0'08, breadth 0"06. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 6. Clathrocircus multiforis, n. sp. (PI. 92, fig. 10). Sagittal ring circular, smooth, with ten to twelve pairs of roundish pores, forming together a complete lattice-girdle with two parallel circular rows of pores. Four larger of these are the four gates of the basal ring (two jugular and two cardinal pores). Dimensions. — Diameter of the ring O'l to 0'15, breadth 0"03 to 0'05. .fia6«!a!l.— Central Pacific, Stations 263 to 274, depth 2350 to 2925 fathoms. Subfamily 2. Cortiniscida, Haeckel. Definition. — S emantida with large, typical, regularly disposed basal feet (origiually three cortinar feet, one odd caudal and two paired pectoral). Genus 411. Cortiniscus,^ n. gen. Definition. — S emantida with three ty|)ical basal feet (an odd caudal foot and two paired lateral or pectoral feet). The genus Cortiniscus is of peculiar importance, as the common ancestral form of the Cortiniscida, or those Semantida in which the basal ring is provided with tj^iical, regularly disposed basal feet — three, four, or six. Since these typical basal feet (or " cortinar feet ") are preserved in the greater number of all Nassellaeia, determining their triradial structure, they possess a great morphological value. Cortiniscus exhibits the same three primary feet as Cortina, from which it difi"ers in the production of two or more basal pores (between the odd caudal and the paired lateral feet). 1. Cortiniscus tripodiscus, n. sp. (PL 92, fig. 11). Sagittal ring ovate, thorny, with three prominent, distorted edges ; its dorsal rod nearly straight and vertical, with one or two pairs of short thorns ; its ventral rod strongly curved, with three or four pairs of divergent thorns. Basal ring larger than the sagittal ring, with two semicircular gates and obUquely ascending halves, which on the inner and lower edge are smooth, 1 CorimiscJis= Small cortina or tripod. 964 THE VOYAGE OF H.M.S. CHALLENGER. on the outer and upper thorny. Apical horn and the three divergent feet nearly equal, straight, about as long as the sagittal ring, with three thorny edges. Dimensions. — Height of the sagittal ring 01 to 012, breadth 0'07 to 0'09. Habited. — Central Pacific, Stations 270 to 274, dejjth 2350 to 2925 fathoms. 2. Cortiniscus dipylaris, n. sp. (PI. 92, fig. 13). Sagittal ring nearly semicircular, with prominent distorted edges and six pairs of small roundish piapillate tubercles (three pairs on the straight dorsal, three on the curved ventral rod). Apical horn short and stout, with a tuberculate knob. Basal ring smaller than the sagittal ring with two elliptical gates. Three feet short and stout, irregularly branched Kke a cauliflower, with numerous short papillate tubercles. Di)nc7isions. — Height of the sagittal ring Oil, breadth 0'08. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 3. Cortiniscus tripylcms, n. sp. Sagittal ring elHptical, smooth. Apical horn conical, smooth. Basal ring larger than the sagittal ring, with three elKptical gates of equal size ; two paired, posterior (jugular pores) between the basal parts of the caudal foot and the two pectoral feet), and an odd, anterior (sternal pore) between the basal parts of the two pectoral feet and a connecting horizontal convex sternal bow. Dimensions. — Height of the sagittal ring 0"09, breadth 0"06. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 4. Cortiniscus tetrapylaris, n. sp. Sagittal ring elliptical, with four pairs of short branched thorns, two posterior on the straight dorsal, and two anterior on the curved ventral rod. Basal ring smaller than the sagittal ring, with four triangular gates ; the two anterior (jugular pores) a little smaller than the two posterior (cardinal pores). Apical horn and the three divergent feet shorter than the sagittal ring, irregularly branched, with curved, often tuberculate branches. Dimensions. — Height of the sagittal ring 0'08 to 0'012, breadth 0'06 to 01. Habitat. — Fossil in Barbados. 5. Cortiniscus typicus, n. sp. (PI. 92, fig. 12). Sagittal ring ovate, thorny, with three distorted edges ; dorsal rod nearly straight and vertical prolonged upwards into a stout thorny apical horn, downwards into the caudal foot. Basal ring smaller than the sagittal ring, with four elliptical or nearly triangular gates ; the two anterior (jugular pores) about half as large as the two posterior (cardinal pores). Three feet of equal size, thorny, divergent, straight or slightly curved, about as long as the diameter of the sagittal ring. Dimensions. — Height of the sagittal ring 014 to 018, breadth 01 to 012. Habitat. — Cosmopolitan; Atlantic, Indian, Pacific, at various depths. REPORT ON THE RADIOLARIA. 965 Genus 412. Stephaniscus,^ n. gen. Definition. — S emantida with four typical basal feet (two sagittal and two lateral or pectoral feet). The genus Stephaniscus differs from the preceding Cortiniscus in the production of a fourth (sternal) foot, and therefore exhibits the same relation to it that Stephanium among the Stephanida bears to Cortina. It differs from Stephanium in the pro- duction of a basal ring, with pores or gates between the bases of the basal feet. Two of these feet are sagittal (the posterior caudal and the anterior sternal foot), whilst the other two are lateral or pectoral (right and left). The basal lattice-plate exhibits either two pores ("jugular gates") or four pores (two anterior jugular and two posterior cardinal gates). 1. Stephaniscus tetrapodius, n. sp. Sagittal ring nearly circular, smooth, with a short conical apical horn. Basal ring square, smooth, with two triangular gates. Four feet simple, equal, conical, divergent, about as long as the diameter of the ring. Dimensions. — Height of the sagittal ring 0'08, breadth 0'07. Habitat. — Central Pacific, Stations 270 to 274, depth 2350 to 2^25 fathoms. 2. Stephaniscus quadrifurcus, n. sp. (PI. 92, fig. 14). Sagittal ring subcircular, thorny, with a small thorny apical horn. Basal ring also nearly circular, with two large semicircular gates and a few small thorns. All four feet curved and forked, the fork-branches again ramified, with numerous short curved and pomted branches. The two lateral feet (right and left) are larger and more branched than the two sagittal feet (sternal and caudal foot). Dimensions. — Height of the sagittal ring 0'12, breadth O'l. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 3. Stephaniscus quadrigatus, n. sp. (PI 92, fig. 15). Sagittal ring oblique, ovate, with three prominent thorny edges ; its dorsal rod nearly straight and vertical, the ventral rod strongly curved ; apex with a small curved horn. Basal ring with a few short thorns and four gates of different size ; the two anterior (jugular pores) ovate or nearly triangular, two-thirds as broad as the two posterior subcircular or pentagonal (cardinal pores). All ■ Stephaniscus = Small coronet or garland ; oTipetnlux-os. 966 THE VOYAGE OF H.M.S. CHALLENGER. four feet simple, curved, with three edges, the posterior (caudal) foot larger, the anterior (sternal) foot smaller than the two lateral (pectoral) feet. Dimensions. — Height of the sagittal ring 0-09, breadth 0'07. Habitat. — Tropical Atlantic, Station 351, surface. 4. Stephaniscus medusinns, n. sp. Sagittal ring elliptical, thorny, with a larger apical horn. Basal ring nearly square, with short marginal thorns and four large ovate gates of nearly equal size. All four feet of equal size divergent, curved, irregularly branched, with short curved branches. Dimensions. — Height of the sagittal ring 013, breadth 0'09. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. Genus 413. Semantiscus,^ n. gen. Definition. — S emantida with six typical basal feet (two sagittal, two pectoral, and two tergal feet). The genus Semantiscus may be the archetype of those Nassellaria which exhibit six typical basal feet, in combination with the sagittal ring. Three of these are the primary feet of Cortina and Cortiniscus, the other three are secondary productions between the former. The basal ring may possess either two, four, or six basal pores. 1. Semantiscus hexajwdius, n. sp. (PI. 92, fig. 16). Sagittal ring elliptical, with a large branched apical horn. Basal ring small, square, with two small triangular gates (or jugular pores). From its periphery there arise six short and stout cylindrical feet, one very large (caudal) from the posterior corner, two tergal on each side, two opposite (pectoral) from the lateral corners, and one odd sternal from the anterior corner. All six spines bear a bunch of ten to twenty stout pointed conical branches, partly simple, partly forked. Dimensions. — Height of the sagittal ring 012, breadth 0'08. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Semantiscus hexaspyris, u. sp. (PL 92, fig. 18). Sagittal ring semicircular, broad, latticed, with two pairs of irregular dorsal and two pairs of ventral pores. The dorsal rod is straight and vertical, prolonged upwards into a short serrate apical horn, downwards hito a straight Hnear caudal foot. The ventral rod is curved and prolonged into a similar sternal foot. Basal ring hexagonal, with four ovate gates (two smaller jugular and two larger cardinal pores); its four lateral corners prolonged into four curved thorny lateral feet (two ^ Semantiscus = Small signet-rmg; anfiauriaxo;. REPORT ON THE RADIOLARIA. 967 anterior larger pectoral, and two posterior smaller tergal feet). This species may be regarded as a commencing Hcxaspyris or Liriosjnjris. Dimensions. — Height of the sagittal ring 0"08, breadtli 0'06. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 3. Semantiscus hexajyylus, n. sp. (PI. 92, fig. 17). Sagittal ring ovate, thorny, with a small apical horn. Basal ring with six roundish or nearly triangular gates ; the two jugular pores are smaller than the two cardinal and larger than the two cervical pores. The separating bars between these six pores are prolonged into six straight, thorny widely divergent feet ; three larger feet (the caudal and the two pectoral) with a pair of apophyses three smaller between them simple (the sternal and the two tergal feet). DimcTisions. — Height of the sagittal ring 0"1.3, breadth 0'09. HabUat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. Family L. Cokonida, Haeckel. TriostepMda, Haeckel, 1881, Prodromus, p. 445. Definition. — S tephoidea with tw^o crossed vertical rings, perpendicular one to the other (the primary sagittal and the secondary frontal ring). Usually their common base bears a horizontal basal ring, but a mitral ring (or a horizontal ring at the apex) is never developed. The family Coronida comprises those Stephoidea in which the primary sagittal ring (of the Stephanida and Semantida) becomes crossed by a second vertical ring, the lateral or frontal ring. Between these two vertical meridian rings, perpen- dicular to one another, four large apertures remain constantly open, the " lateral " gates. But besides these four constant openings, usually (excepting only in the Zygo- stephanida) other gates are developed on the common base of the two crossed rings, produced by a third, horizontal, basal ring. These basal gates are the same which we have found already in the Semantida. The distinction of the Coronida from the other Stephoidea is always easy. In the Stephanida and Semantida, the frontal ring, or the second meridian ring, which we find in all Coronida, is never developed. On the other hand these latter never exhibit the tj^iical "mitral ring," or the second, upper, horizontal ring, which distinguishes the Tympanida. We distinguish here, among the Coronida, four different subfamilies, which perhaps afterwards may be better separated as families. Of these four groups the Zygo- stephanida and Acanthodesmida exhibit the nearest relationship to the Stephanida, whilst the Eucoronida and Trissocyclida possess a closer affinity with the Semantida. 968 THE VOYAGE OF H.M.S. CHALLENGER. The Zygostephauida, constituting the first subfamily, exhibit four large gates only, and differ from all other Coronida in the absence of a basal ring and of basal gates. Therefore the skeleton is entirely composed of two crossed vertical rings, perpendicular to one another; the first is the primary or sagittal ring (inherited from the Stephanida), the second is the new lateral or frontal ring. The four large lateral gates are either quite simple [Zygostophanus) or partly closed by loose and irregular lattice-work {Zygo- stephanium). The Zygostephauida may be derived directly from the Stephanida by development of lateral branches forming a frontal ring. They commonly possess the same characteristic spines or branches, and the same typical difi"erence between the straight dorsal rod and convex ventral rod of the sagittal ring, which we found in the greater number of Stephanida. The frontal ring is commonly elliptical or kidney-shaped, and much larger than the ovate sagittal ring. The Acanthodesmida, forming the second subfamily of Coronida, differ from aU other members of this family in the possession of a large simple basal gate, surrounded by a simple horizontal basal ring. Only this ring is complete, whilst the two crossed vertical meridian rings (the primary sagittal and the secondary frontal ring) are incomplete, both truncated at the base by the basal ring. Therefore there remain here between the three rings five large gates (recognised previously by Johannes Miiller in 1856 inAcantho- desmia) : four lateral gates (the same as in the Zygostephauida) and one central basal gate. The latter is always quite simple, and serves for the emission of the pseudo- podia, arising from the basal pole of the central capsule. The fovir lateral gates are either quite simple {Coronidium) or partly closed by irregular loose lattice-work {Acanthodesmia). The subfamily Acanthodesmida may be derived either directly from the Stephanida (by development of a central basal gate) or from the Eucoronida (by loss of the basilar part of the sagittal ring). The Eucoronida, the third subfamily, are the most important group of the Coronida ; their numerous species are much more frequent and more widely distributed than those of the other three subfamilies. They may be derived immediately from the Semantida by the development of a lateral or frontal ring. This remains incomplete in the basal part, whilst the two other rings, perpendicular to it (the vertical sagittal ring and the horizontal basal ring), are comj)lete. Therefore the shell constantly exhibits six large open gates between the three rings ; four lateral gates (the same as in the Zygo- stephauida and Acanthodesmida) and two basal gates (inherited from Semantis) ; the latter correspond to the " jugular pores " of the Spyroidea and Cyrtoidea; they remain constantly simple. The four lateral gates may also remain simple {Eucoronift) or they may become partly closed by irregular loose lattice-work {Plectocoronis). The remarkable genus Podocoronis is distingiiished by the development of typical descending basal feet, which are regularly disposed and correspond to the typicfd " cortinar feet " of the other Nassellaeia. There may be developed either two lateral feet (as lower REPORT ON THE RADIOLARIA. 969 prolongations of the segments of the frontal ring), or three feet (one caudal and two pectoral, as in Cortina and Cortiniscus), or four feet (two sagittal and two lateral, as in Stephanium and Stephaniscus), or six feet (two sagittal, two pectoral, two tergal, as in Semantiscus), sometimes numerous feet (as in Petalospyris and Anthocyrtis, &c.). The Trissocyclida represent the fourth and last subfamily of Coronida, distinguished from all others in the possession of three complete rings, perpendicular one to another, and of eight large gates separated by them. Two of the three rings are vertical (the primary sagittal and the secondary frontal ring), the third is horizontal (the basal ring). The four upper gates correspond to the four lateral gates of the preceding three subfamilies ; the four lower gates are the same as the four basal gates of Semantrum (two primary jugular and two secondary cardinal gates) ; therefore the Trissocyclida may be derived directly from these Semantida by development of a complete frontal ring. Probably the two jugular gates were originally smaller than the two cardinal, but usually they have become equal. In Tristephanium (the common ancestral form of the Trissocyclida) and in the closely allied Tricyclidium the four basal gates remain smaller than the four lateral gates. But in two other genera, Tfissocircus and Trissocyclus, the four lower or basal gates reach the same size as the four upper or lateral gates ; therefore all eight gates become equal and the basal ring becomes equatorial. In the most regular species of the latter genera also the three rings become perfectly equal and cannot be any longer distinguished. Here the original bilateral (or dipleuric) funda- mental form of the shell passes over into a regular cubic or octahedral form (with three equal, isopolar axes,, perpendicular one to another). The eight large gates of the Trissocyclida usually remain simple [Tristephanium, Trissocircus), but sometimes they become partly closed by loose lattice-work {Tricyclidium, Trissocyclus). The original rings, and the secondary rods or bars, composing the loose framew^ork of the Coronida are either roundish (with circular or eUi^^tical transverse section) or three-edged (with triangular transverse section), rarely quadrangular or provided with distorted edges. The branches or spines arising from them, are either simple or branched, and offer a great variety in number, form, and disposition. The most important forms are those which develop the three tj^ical basal feet of Cortina, e.g., Podocoronis cortina (PL 97, fig. 2). The Central Capjside of the Coronida is the same as in the other Stephoidea (comp. p. 937), and offers all those characteristic peculiarities of " Monopylea " which we have mentioned above in the general description of the Nassellakia (p. 890). Usually it is spherical or ellipsoidal, often \dolin-shaped or bilolied, with a sagittal constriction. The porochora of its basal pole is in close contact -nith the l)ase of the sagittal ring. (ZOOL. CHAT.L. EXP. PAHT XL. — 1886.) Rr 122 970 THE VOYAGE OF H.M.S. CHALLENGER. I. Subfamily Zygostephanida. Four lateral gates (no basal gate). II. Subfamily Acantliodesmida. Five large gates (four lateral and one simple basal). III. Subfamily Eucoronida. Six large gates (four lateral and two basal). Spiojysis of the Genera of Coronida. Two meridional rings ] (sagittal and frontal) I -p, i . i , • i ^ ° 1 , ' r our lateral gates simple, complete, perpen- 1 or; ,, , 11 Four lateral gates partly latticed, another (no basal | o i- j > ring). J Two meridional rings (sagittal and frontal) incomplete, botli truncated by the complete horizontal | basal ring. J Two rings (the sagittal meridional ring and the horizontal basal ring) complete, the ' frontal meridian ring incomplete. Four lateral gates simple, Four lateral gates partly latticed. Basal ring without larger descending feet. Gates simple, . Gates partly lat- ticed, Basal ring witli large, regularly disposed, descending feet. Gates simple, 414. Z)jgodeplianus. 415. Zijgostephanium. 416. CoronicUum. Wl. A canthodesmia. 418. Eucoronis. 419. Pledocoronis. 420. Podocoronis. IV. Subfamily Trissooyclida. Eight large gates (four upper lateral and four lower basal). Four upper gates larger than the Two meridional rings (sagittal and frontal) and the horizontal , j. , 1 1 . 1 i lour lower. basal nng complete. < All three complete rings perpendicular . i, . , , , , ° ^ ^,, All eight gates to one another. c ^ ■ i ot equal size. Gates simple, . 421. Tristephanium. Gates partly lat- ticed. 422. Trkijdidium. Gates simple, . 423. Trissodrais. Gates partly lat- ticed, 424. Trissocydux Subfamily 1. Zygostephanida, Haeckel, 1881, Prodromus, p. 446. Definition. — C o r o n i d a with four large lateral gates, without basal gate. Skeleton composed of two complete vertical rings, perpendicular one to another — the ]5rimary sagittal and the secondary frontal ring. Genus 414. Zygostephanus,^ Haeckel, 1862, Monogr. d. Eadiol., p. 268. Definition. — C o r o n i d a with four large, simple, lateral gates, without basal gate and lattice-work. Skeleton composed of two simple meridional rings, perpendicular to one another. The genus Zygosteplianus, founded by me in 1862 for the Mediterranean Zygoste- ■phanus mUlleri, is the simplest and most primitive of all the Coronida, and may there- ' Zygostephanm = YdkeA ring ; ^vyou, aTi(ficiiios. REPORT ON THE RADIOLARIA. 971 fore be regarded as the common ancestral form of this family. The simple skeleton is composed of two meridional rings only, perpendicular one to another — a sagittal and a frontal ring. Subgenus 1. Zijgostephus, Haeckel, 1881, Prodromus, p. 446. Definition. — The two vertical rings of nearly equal height, therefore without sagittal constriction. 1. Zygostephanus dissocircus, n. sp. (PI. 93, fig. 1). Both rings elliptical, of nearly equal height, smooth, without spines. Frontal ring somewhat longer than the sagittal. No sagittal constriction. Dimensions. — Height of the rings 0'07, breadth 0"1. Habitat. — Cosmopohtan; Mediterranean, Atlantic, Pacific, surface. 2. Zygostep)hanus serratus, u. sp. Both rings elliptical, of nearly equal height, with a serrate prominent edge on the outer convexity (in the transverse section three-edged). No sagittal constriction. Dimensions. — Height of the rings 0'08, breadth 012. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 3. Zygostephanus mulleri, Haeckel. Zygostephanus miilleri, Haeckel, 1862, Monogr. d. Radiol., p. 268, Taf. sii. fig. 2. Both rings eUiptical, of nearly equal height, armed with numerous (about fifty) slender curved spines, as long as the radius of the rings ; commonly each ring with twelve pairs of divergent spines. No sagittal constriction. Dimensions. — Height of the rings 0'06, breadth 0*1. HaMtat. — Mediterranean (Messina), surface. 4. Zygostephanus ramosus, n. sp. Both rings eUiptical, of nearly equal height, armed with numerous branched spines, which are arranged on each ring in two divergent rows ; the branches of the spines are curved and partly protect the open gates. No sagittal constriction. Dimensions. — Height of the rings 0'07, breadth 0*09. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 972 THE VOYAGE OF H.M.S. CHALLENGER. Subgenus 2. Zygostephanisciis, Haeckel, 1881, Prodromus, p. 446. Definition. — The two vertical rings of different heights; the frontal ring higher than the sagittal ring, therefore with a sagittal constriction in the median plane. 5. Zygostephanus reniformis, n. sp. Frontal ring kidney-shaped, in the upper half convex, in the lower half concave, in the latter with a deep sagittal constriction, armed with numerous irregular short spines. Sagittal ring thicker and lower, only two-thirds as high, with four pairs of short divergent spines (two ventral and two dorsal pairs). Dimensions. — Height of the frontal ring 0"13, breadth 0'2. Edbitat. — Central Pacific, Station 271, depth 2425 fathoms. 6. Zygostephanus violina, n. sp. Frontal ring violin-shaped, on the upper and the lower margin concave, with a deep sagittal constriction, armed with numerous irregular spines, which are partly simple, partly branched. Sagittal ring thicker and lower, only half as high, with a few sl:ort conical spines at the apical and basal poles. Dimensions. — Height of the frontal ring 0'12, breadth 0'18. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 7. Zygostephanus hicornis, n. sp. (PI. 93, fig. 2). Frontal ring violin-shaped, on the upper and the lower margin concave, with a deep sagittal con- striction ; its two halves pentagonal. Between numerous smaller spines there arise from the frontal ring six groups of larger branched spines, two odd in the corners of the highest points (curved like two horns), two branched pairs on the prominent lateral corners (at right and left), and two pairs in the corners of the lowest points (like four branched basal feet). Sagittal ring only two-thirds as high, with four pairs of irregular spines. Dimensions. — Height of the frontal ring Oil, breadth 0'16. Habitat. — South Pacific, Station 300, depth 1375 fathoms. Genus 415. Zygostephanium,'^ Haeckel, 1881, Prodromus, p. 446. Definition. — C o r o n i d a with four large, partly latticed, lateral gates, without basal gate. Skeleton composed of two meridional rings j^erpendicular to each other. The genus Zygostephanium differs from the preceding ancestral genus Zygostephanus in the development of lattice-work along the two crossed rings, produced by their anasto- mosing branches. Therefore the four large lateral gates between them, which are quite simple, in the preceding genus here become more or less fenestrated. 1 Zygostephamu'm='S)Vii?t& yoked ring ; ^vyor, anipai/iov. REPORT ON THE RADIOLARIA. 973 1. Zygostephanium dizonium, u. sp.. (PI. 93, fig. 3). Tijmpanieciis dizonuis, Haeckel, 1882, Manuscript. Both rings elliptical, of nearly equal height, smooth, without spines. Sagittal ring with four pairs of small pores (two apical pairs and two basal pairs). Frontal rmg with three pairs of small pores (one pair lateral, one pair above and one pair below). Dimensions. — Height of the frontal ring 0*08, breadth 0^12. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 2. Zygostejyhanium paradictyum, n. sp. (PI. 93, fig. 4). Frontal ring kidney-shaped, in the upper half convex, in the lower concave, in the latter with a deep sagittal constriction. Sagittal ring ovate, about two-thirds as high as the frontal ring. Both rings three-edged, armed with numerous short and branched bristle-shaped spines, which anasto- mose along their three edges and produce two series of irregular polygonal pores. Dimensions. — Height of the frontal ring 0"08, breadth 0'13. Sabitat. — North Pacific, Station 236, surface. 3. Zygostephanmm constrictum, u. sp. Frontal ring violin-shaped, concave on the upper and lower margins, with a deep sagittal constriction. Sagittal ring ovate, about two-thirds as high as the frontal ring. Both rings covered with numerous branched irregular spines, which partly anastomose along the edges of the rings, and produce small irregular polygonal pores. Dimc'iisio'ns. — Height of the frontal ring 0"12, breadth 018. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. Subfamily 2. Acanthodesmida, Haeckel, 1881, Prodromus, p. 445.. Definition. — C o r o n i d a with five large gates (four lateral and one basal). Skeleton composed of three rings, perpendicular one to another, two of which are vertical and incomplete (the primary or lateral, and the secondary or frontal), the third is horizontal and complete (the tertiary or basal ring). Genus 416. Coronidium,^ Haeckel, 1881, Prodromus, p. 445. Definition. — C o r o n i d a with five large simple gates (four lateral and one basal). Skeleton composed of two incomplete meridional rings and one comj3lete basal ring, without lattice -work. ' CoroJiiiium = Small crown ; xo^uhHiov. 974 ■ THE VOYAGE OF H.M.S. CHALLENGER. i The genus Coronidium aud the following, nearly allied Acanthodesmia, form together the peculiar subfamily of Acanthodesmida — not in the wider sense in which I first founded this group (1862, Monogr. d. KadioL, p. 265), but in the restricted sense, which is exactly defined in my Prodromus (1881, p. 445). According to this definition, the shell is composed of three different rings, perpendicular to one another ; only one of these is complete, the simple horizontal basal ring ; the two others are incomplete and vertical (the primary or sagittal and the secondary or frontal ring). Therefore there remain constantly between the three rings five characteristic large oj)enings or gates ; four of these are lateral (between the halves of the two meridional rings), the fifth is basal, enclosed by the horizontal basal ring. The longest known type of this subfamily is Acanthodesmia vinculata, the five characteristic gates of which are clearly distinguished by its discoverer, Johannes Miiller (" Das Gehause besteht nur aus den Leisten zwischen fiinf grossen Lticken "). The Acanthodesmida may be derived from the Eucoronida by reduction of the basilar rod of the sasfittal rino-. If in Eucoronis this basal rod be lost, Coronidium arises. 1. Coronidium dyostephanus, n. sp. (PL 82, fig. 7). Frontal ring elliptical, with few scattered thorns, twice as broad as high, and three times as broad as the smooth rhombic basal ring. Sagittal ring semicircular, very stout, twice as thick as the two other rings, with short lateral thorns (in the figure seen from the apical pole, which exhibits a four-lobed dimple). Basal gate rhombic. Dimensions. — Height of the fi-ontal ring 0"08, breadth 0'16. Habitat. — Central Pacific, Station 263, depth 2650 fathoms. 2. Coronidium diadema, n. sp. (PL 82, fig. 8). Frontal ring kidney-shaped, one and a half times as broad as high, with a slight sagittal con- striction. Sagittal ring ovate, smaller, about of the same size as the elliptical basal ring. Eods of all three rings cylindrical, bearing numerous short and stout curved spines, partly sim^jle, partly branched. Four bunches of larger spines on the four corners of the basal ring, and one very large bunch on the apical pole. Basal gate elliptical, one and a half times as broad as long. Dimensions. — Height of the frontal ring 013, breadth 0'18. Habitat. — Indian Ocean (Madagascar), Piabbe, surface. 3. Coronidium cervicorne, n. sp. (PL 82, fig. 1). Frontal ring kidney-shaped, twice as broad as high, one and a half times as broad as the elliptical basal ring, both with a slight sagittal constriction. Sagittal ring ovate. All three rings EEPORT ON THE RADIOLARIA. 975 (in the figure seen from the apical pole) with cylindrical rods, armed with numerous stout spines, branched like a deer's antler. Basal gate rather oblong, twice as broad as long. Dimensions. — Height of the frontal ring 008, breadth 016. EaUtat. — Central Pacific, Station 272, depth 2600 fathoms. 4. Coronidium acacia, n. sp. (PI. 82, fig. 2). Frontal ring and sagittal ring nearly circular, of equal size, truncated at the base. Basal ring circular, somewhat smaller. All three rings with prominent edges, bearing bunches of short and straight pointed spines, like those of an Acacia. Basal gate circular. Dimensions. — Height of the frontal rin" 0'12, breadth 0'14. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. Genus 417. Acanthodesmia,^ J. Miiller, 1856, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 485. Definition. — Coronida with five large, partly latticed gates (four lateral and one basal). Skeleton composed of two incomplete, partly fenestrated meridional rings, and one complete basal ring. The genus Acanthodesmia, the oldest known form of all Coronida, differs fi-om the preceding Coronidium, its ancestral form, in the development of nregular loose lattice- work along the rings, and therefore bears to it the same relation that Zygostephanium does to Zygostephanus. The first species described by Johannes Miiller, Acantho- desmia vinculata ("with five large gates between the bars of the shell") remains the true type of this genus ; the second species described by him (Acanthodesmia dumetum) belongs to the Plectanida [Polyplecta). 1. Acanthodesmia vincidata, J. Miiller. Acanthodesmia vinculata, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 30, Taf. i. figs. 4-6 (non 7). Lithocircus vincukdus, J. Miiller, 1856, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 484. Frontal ring \iolin-shaped, one and a half times as broad as high, with a sagittal constriction. Sagittal ring ovate, smaller. The four gates between the two rings are partly fenestrated by a few thin threads, irregularly branched and connecting the two rings. A few short thorns are scattered here and there. Basal gate elliptical. Dimensions. — Height of the frontal ring 012, breadth 0'18. Habitat. — Mediterranean (Nice), Atlantic (Canary Islands), surface. 1 Acanthodesmia = Thorn-band ; oLkx-jScc, "iicfuoi. 97(> THE VOYAGE OF H.M.S. CHALLENGER. 2. Acanthodesmia ceratospyris^ n. sp. Frontal ring violin-shaped, one and a half times as broad as high, with a deep sagittal con- striction, Sagittal ring semicircular, half as high as the frontal ring. The four gates between the two rings are partly fenestrated by anastomosing branches of the numerous, irregularly branched spines, wliich cover all three rings. Basal gate nearly circular, smaller than the sagittal ring. Dimensions. — Height of the frontal riug 0'08, breadth 0"12. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 3. Acanthodesmia corona, n. sp. (PL 93, fig. 5). Frontal ring kidney-shaped, nearly twice as broad as high, with a fiat sagittal constriction. Sagittal ring semicircular. The four gates between the two rings are partly fenestrated by an arachnoidal network, composed of thin, irregularly branched threads, arising from the rings. The edges of aU three rings are armed with irregular thorns. Basal gate circular, larger than the sagittal ring. Dimensions. — Heisfht of the frontal rinir 0'08, breadth 0'14. Habitat. — Indian Ocean (Madagascar), Eabbe, surface. 4. Acanthodesmia miilleri, n. sp. Frontal ring kidney-shaped, with a deep sagittal constriction. Sagittal riug ovate. The four gates between the two rings irregularly fenestrated, with a few large polygonal meshes. Edges of the rings with a few scattered thorns. Basal gate viohn-shaped. Dimensions. — Height of the frontal riug O'l, breadth 0'16. Habitat. — Tropical Atlantic, Station 347, surface. Subfamily 3. Eucoeonida, Haeckel, 1881, Prodromus, p. 445. Definition. — C o r o n i d a with six large gates (four lateral and tw^o basal gates). Skeleton composed of three rings perpendicular to one another, two of which are complete (the vertical sagittal, and the horizontal basal ring) ; the third is incomplete (the vertical frontal riug). Genus 418. Eucoronis,^ Haeckel, 1881, Prodi'omus, p. 445. Definition. — C o r o n i d a with six large simple gates (four lateral and two basal). Skeleton composed of two complete rings (the sagittal and basal) and one incomplete (frontal) ring. Basal ring without typical feet ' Eucoronis = Good cro\*Ti ; iv, y.o^mii. EEPORT ON THE EADIOLARIA. 977 The genus Eucoronis and the following two nearly allied genera [Plectocorvnis and Podocoronis) compose together the important subfamily Eucoronida. In this typical main group of Coronida the shell is constantly composed of three rings and six gates. The vertical sagittal ring and the horizontal basal ring are complete (as in the Semantida); the vertical frontal ring is incomplete. Between these three rings remain six large open gates, the four upper (or lateral) are always much larger than the four lower (or basal gates). Eucoronis may be derived from Semantis by development of the frontal ring. Subgenus 1. Acrocoronis, Haeckel, 1881, Prodi'omus, p. 445. Definition. — Rings smooth or rough, armed with numerous short spines or thorns. 1. Eucoronis j^erspicillum, n. sp. (PL 82, fig. 6). Frontal ring elliptical, twice as broad as high, with a slight constriction at the apical pole, armed with three pairs of short conical spines, one apical pair (near the constriction) and two lateral pairs (one upper and one lower pair). Sagittal ring of the same height, half the breadth and double the thickness, also armed with three pairs of spines (one basal, one dorsal, and one ventral pair). Dimensions. — Height of the frontal ring 0"11, breadth 0"22. Hahitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms. 2. Eucoronis Icevigata, n. sp. Frontal ring elhptical, smooth, one and a half times as broad as high, without sagittal constric- tion, with horizontal basal gates. Sagittal ring of the same height and thickness, also elliptical and smooth. No spines on either of the smooth rings. Dimensions. — Height of the frontal ring G4, breadth 0'15. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 3. Eucoronis nephrospyris, n. sp. (PI. 82, fig. 5). Frontal ring kidney-shaped, in the upper half convex, in the lower concave, with a sagittal constriction (often much deeper than in the specimen figured). Sagittal ring ovate, about two- thirds as high as the frontal ring. Eods of both rings without edges, cylindrical, armed with numerous short conical thorns. Dimensions. — Height of the frontal ring O'l to 0'12, breadth 0"15 to 0'18. Habitat. — CosmopoHtan ; Meditenanean, Atlantic, Indian, Pacific, many Stations, surface and at various depths. (ZOOL. CHAI-L. EXP. PART XL. — 188G.) Rr 123 978 THE VOYAGE OF H.M.S. CHALLENGER. 4. Eucoronis angulata, n. sp. (PI. 82, fig. 3). Frontal ring violin-shaped, twice as broad as high, on the upper and the lower margin concave, with a deep sagittal constriction. Sagittal ring pentagonal, with straight horizontal basal rod, two- thirds as high as the frontal ring. Eods of both rings with sharp prominent edges, bearing numerous short pyramidal spines. Dimensions. — Height of the frontal ring 0'09, breadth 017. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. Subgenus 2. Llthocoronis, Haeckel, 1881, Prodromus, p. 445. Definition. — Rings armed with numerous large, branched or arborescent spines. 5. Eucoronis cervicornis, n. sp. Frontal ring kidney-shaped, in the upper half convex, in the lower concave, with sagittal con- striction. Sagittal ring ovate, two-thirds as high as the frontal ring. Both rings armed with numerous stout spines, irregularly branched like a deer's antler. (Very similar to Goronidium ccrvicorne, PI. 82, fig. 1, which I formerly confounded with it, but differing in the complete sagittal ring, which in the latter form is incomplete and has lost its basal part.) Dimensions. — Height of the frontal ring 0'12, breadth 0-2. Habitat. — Central Pacific, Station 264, surface. 6. Eucoronis arborescens, n. sp. Frontal ring kidney-shaped, with a deep sagittal constriction in the concave basal part. Sagittal ring ovate, half as high as the frontal ring. Both rings armed with numerous thin, richly branched and arborescent spines (branches much thinner and more numerous than in the preceding and following species). Divunsions. — Height of the frontal ring 015, breadth 0"25. Habitat. — Equatorial Atlantic, Station 247, surface. 7. Eucoronis challengeri, n. sp. (PI. 82, fig. 4). Lithocoronis cliallengeri, Haeckel, 1881, Prodromus, p. 445. Frontal ring violin-shaped, one and a half times as broad as high, with a strong sagittal con- striction. Sagittal ring nearly circular, two-thirds as high as the frontal ring. Both rings armed with numerous irregularly branched spines. (The specimen figured, with red central capsule and numerous xanthelke, was observed living by me at the Canary Islands.) Dimensions. — Height of the frontal ring 01 to 012, breadth 014 to 017. Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific, surface and at various depths. REPORT ON THE RADIOLARIA. 979 Geuus 419. Plectocoronis,^ Haeckel, 1881, Prodromus, p. 445. Definition. — C o r o u i d a with six large, partly latticed gates (four lateral and two basal). Skeleton composed of two complete rings (the sagittal and basal) and one incomplete (frontal) ring. Basal ring without developed typical feet. The genus Plectocoronis differs from the preceding Eucoronis, its ancestral form, in the development of loose irregular lattice-work along the two meridional rings, and therefore bears to it the same relation that AcantJwdesmia does to Coronidium. If the lattice-work become more complete and close the gates, these Coronida pass over directly into S p y r o i d e a (Zygospyrida) . 1. Plectocoronis anacantha, n. sp. Basal ring and frontal ring elliptical, without sagittal constriction. Sagittal ring ovate. The frontal and sagittal rings are bordered on both edges with an incomplete series of small irregular pores. All three rings smooth, without spines. Dimensions. — Height of the frontal ring O'l, breadth 0'16. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 2. Plectocoronis triacantha, n. sp. Basal ring and frontal ring nearly circular, without sagittal constriction. Sagittal ring elHptical, prolonged at the apex into an apical horn from which two branched lateral bows descend and unite with the uppermost parts of the frontal ring. Four other small bows descend fi-om the lowermost parts of the latter and unite with the basal ring. From the lateral corners of the basal ring descend two short vertical feet. (May be regarded as derived from Podocoronis toxarium, PL 83, fig. 7, by development of the bows connecting the rings.) Dimensions. — Height of the frontal ring O'll, breadth 0'13. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 3. Plectocoronis pentacantha, n. sp. (PI. 93, fig. 6). Basal ring and frontal ring kidney-shaped, with deep sagittal constriction. Sagittal ring ovate, prolonged at the apex mto an oblique born. From the edges of the angular rings dehcate threads arise, which anastomose and form irregular arachnoidal meshes, partly closing the four open lateral gates. Two basal gates simple. From the four nodal points of the basal ring there arise four, short diverging feet, comparable to rudimentary cortinar feet (two lateral from the frontal ring and two sagittal from the primary ring, as basal prolongations). Dimensions. — Height of the frontal ring 0'12, breadth 018. Habitat. — Central Pacific, Station 271, surface. ^ Plectocoronis = Crowu with framework; 'TrTiSxros, xo^ai/ig. 980 THE VOYAGE OF H.M.S. CHALLENGER. Genus 420. Podocoronis,^ Haeckel, 1881, Prodromus, p. 445. Definition. — C o r o n i d a with six large gates (four lateral and two basal). Skeleton composed of two complete rings (the sagittal and basal) and one incomplete (frontal) ring. Basal ring provided with typical, regularly disposed, descending feet (cortinar feet). The genus Podocoronis difiers from the two preceding nearly allied genera in the development of typical radial feet on the basal ring, which by their regular disposition and their general ajapearance among the Spyroidea and Cyrtoidea obtain great morphological importance. According to the different number and disposition of these basal feet (or " cortinar feet "), the following subgenera may be distinguished (regarded in my Prodromus, 1881, p. 445, as separate genera) : — Dipocoronis with two lateral feet, Tripocor-onis with three cortinar feet (most important !), Tetracoronis with four crossed feet, Hexacoronis with six radial feet, Stylocoronis with numerous (8 or more feet). These subgenera have important relations to the corresponding genera of Zygospyrida. Subgenus 1. Dipocoronis, Haeckel, 1881, Prodromus, p. 445. Definition. — Basal ring •with two descending lateral feet (right and left) as pro- longations of the frontal ring. 1. Podocoronis dipodiscus, n. sp. Basal ring nearly circular, with two conical, straight, parallel descending feet, which are direct lateral prolongations of the subcircular fi-ontal ring, and half as long as it. The ovate sagittal rino- bears at the apex a short conical vertical horn. All rings nearly smooth. Dimensions. — Height of the frontal ring 0'12, breadth 0'14. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Podocoronis toxarium, n. sp. (PI. 83, fig. 7). Basal ring elliptical, with two descending, slightly curved conical feet, lateral prolongations of the subcircular frontal ring. The ovate sagittal ring bears at the apex a cyLindrical vertical horn, which is connected by two descending lateral arches (or galear arches) with the uppermost part of the frontal ring. Dinicnsions. — Height of the frontal ring Ol, breadth 013. Habitat. — Central Pacific, Stations 265 to 268, depth 2900 fathoms. ' Podocoronis != Crown with feet; tov;, xojan';. REPORT ON THE RADIOLARIA. 981 Subgenus 2. Tripocorouis, Haeckel, 1881, Prodromus, p. 445. Definition. — Basal ring with three descending feet (one caudal and two pectoral). 3. Podocoronis cortiniscus, n. sp. (PI. 97, fig. 2). Basal ring violin-shaped, with three straight divergent thorny feet, about as long as the ovate sagittal ring. The dorsal part of the latter is straight, vertical, and prolonged downwards into the caudal foot, upwards into a stout, thorny, vertical apical horn. The ventral part is semicircular and gives off the lateral branches, forming the kidney-shaped sagittal ring. All the rings and their apophyses are armed with stout thorns. This and the following tripodal species may be directly derived from Cortina. Dimensions. — Height of the frontal ring O'l, breadth 0'15. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 4. Podocoronis tripodiscus, n. sp. Basal ring kidney-shaped, with thi-ee large divergent curved feet, nearly twice as long as the semicircular sagittal ring. The straight dorsal part of the latter is prolonged downwards into the caudal foot, upwards into a large branched apical horn, curved backwards. Differs from the preceding species mainly in the longer curved apophyses and in the larger violin-shaped frontal ring. Dimensions. — Height of the frontal ring 0'12, breadth 0'2. Habitat. — North Pacific, Station 238, surface. Subgenus 3. Tetracoronis, Haeckel, 1881, Prodromus, p. 445. Definition. — Basal ring with four descending feet (two sagittal and two lateral). 5. Podocoronis tetrapodiscus, n. sp. Basal ring kidney-shaped, with four stout and straight divergent feet, about as long as the sagittal ring ; two of them are lateral and arise from the basal corners of the vioUn-shaped frontal ring (at its junction with the basal ring) ; two are sagittal, and arise from the basal corners of the semicircular sagittal ring (one posterior caudal and one anterior sternal). The straight dorsal part of the sagittal ring is prolonged upwards into an apical horn. All the rings are thorny. Dimensions. — Height of the frontal ring 015, breadth 0'25. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. Subgenus 4. Hexacoronis, Haeckel. Definition. — Basal riug with six radial descending feet (two sagittal, two pectoral, and two tergal feet). 982 THE VOYAGE OF H.M.S. CHALLENGER. 6. Podocoronis hexapodiscus, n. sp. Basal ring kaolin-shaped, with six conical, vertically descending feet, half as long as the sagittal ring ; two of them are sagittal (arising from the two basal corners of the sagittal ring, caudal and sternal feet) ; the other four are lateral, and prolongations of the forked basal parts of the frontal ring, which is inserted on the basal ring with two forked branches ; the anterior correspond to the pectoral, the posterior to the tergal feet of Hexaspyris. All the rings are thorny. Bimfnsions. — Height of the frontal ring Oil, breadth 0'17. Habitat. — South Pacific, Station 295, depth 1500 fathoms. Subgenus 5. Stylocoronis, Haeckel. Definition. — Basal ring with numerous (eight to twelve or more) descending feet. 7. Podocoronis petalosjyyris, n. sp. Basal ring violin-shaped, with ten to twelve flat lamellar, vertically descending feet, about as long as the ovate sagittal ring. Frontal ring twice as broad as long, elliptical. All rings nearly smooth. Similar to a Petalospyris without lattice-work. * Dimensions.— Jiei^i of the frontal ring O'l, breadtli 0'2. Habitat. — Fossil in Barbados. 8. Podocoronis polypodiscus, n. sp. Basal ring elliptical, with fifteen to eighteen conical, curved, descending feet, half as long as the ■ovate sagittal ring. Frontal ring kidney-shaped, one and a half times as broad as long. All the rings armed with short conical spines. Dimensions.- — -Height of the frontal ring 0'12, breadth 0"18. Habitat. — Central Pacific, Station 273, depth 2350 fathoms. Subfamily 4. Teissocyclida, Haeckel, 1881, Prodromus, p. 446. Definition. — C o r o n i d a with eight large gates (four superior lateral and four inferior basal). Skeleton composed of three complete rings, perpendicular to one another ; two of which are vertical (the primary or sagittal and the secondary oi frontal ring), the third is horizontal (the tertiary or basal ring). Genus 421. Tristephaniuni} Haeckel, 1881, Prodi'omus, p. 445. Definition. — C o r o n i d a with eight large, simple gates of different sizes ; the four upper or lateral gates larger than the four low^er or basal gates. Skeleton composed of three simple complete rings, perpendicular to one another. ^ rmlete horizontal rings. The upper ring, composed of the superior or mitral branches, may be called the mitral ring, the lower ring, formed by the inferior or basal branches, the basal ring. Both rings are commonly of nearly equal size, more rarely of different sizes. Their connection is effected either by the primary (sagittal) ring only, or also by secondary vertical rings, a frontal ring iu the lateral plane, or some diagonal meridian rings between the latter and the former. These vertical rings, which connect both horizontal rings in the form of " columelli©," may be either complete or incomplete; in the latter case their apical and basal parts are lost, the dorsal and ventral parts only being preserved. The Tympanida develop a great variety of different forms, greater than in the three other families of Stephoidea, so that we may distinguish here not less than sixteen genera and seventy-two species. Hitherto only three species were known : Prismatium tripleurum, figured in 1862 in my Monograph, TyiniKinidmm harbadense, figured by Bury in the "fossil Polycystins of Barbados," and Tympaniscus Jibida, described in 1875 by Ehrenberg as a Ceratosjoyris Jihula. The number of species in this large and richly developed group will be considerably augmented l)y further researches. A great many of them exhibit remarkable relations to different Nassellaeia. For better survey of the whole family we distinguish here four subfamilies, the first of which (Protympanida) is probably the common ancestral group of the other three. They may have been derived originally either from the Semantida or directly from the Stephanida. The first subfamily, Protympanida, exhibits a complete primary or vertical sagittal ring, bearing on the upper part a horizontal mitral ring, on the lower part a horizontal basal ring. Therefore the gates of these two parallel rings become bisected by the sagittal ring, each divided into a right and a left half. The sagittal ring itself becomes divided by the two horizontal rings into four parts or rods ; two opposite of these are more or less vertical ; the dorsal (posterior) and the ventral (anterior) rod ; the two other rods are more or less horizontal ; the mitral (upper) and the basal (lower) rod. In Protympanium (PI. 93, fig. 14), the simplest and most primitive form of Tympanida, the connection of the two horizontal rings is effected only by the dorsal and ventral rods of the sagittal ring forming two parallel more or less vertical " columellse." In all other Protympanida accessory columellse are developed between the latter. In the greater number we find two secondary columeUee in the lateral plane, being the lateral REPORT ON THE RADIOLARIA. 989 segments of an incomplete frontal ring (Acrociihus, PI. 93, figs. 15-17). Between the latter and the former there are sometimes developed four tertiary columeUse, as segments of two crossed incomplete diagonal rings {Tympanidium, PL 94, figs. 1, 18). At other times we find six columellte ; here probably the frontal ring is cleft into halves on each side {Tymixiniscus, PL 94, figs. 4-7). Some genera are distinguished by the development of an equatorial ring, or a third horizontal ring (between the upper mitral and the lower basal ring) ; this equatorial ring is either complete [Microcuhus, PL 94, figs. 8-10) or incomplete, developed only laterally {Octotympanum, PL 94, figs. 2, 3). The genus Toxarium (PL 93, figs. 18-20) is distinguished by the development of accessory pairs of bows in the frontal plane, upper or galear bows and lower or thoracal bows, remarkable as beginnings of the accessory joints, which we distinguish in many Spyroidea and Cyrtoidea as" galea and thorax." The second subfamily of Tympanida are the Paratympanida, in which the two horizontal rings become closed by lattice-work. The numerous columellse connecting the two rings are here either divergent (Paratympanum, with two unecjual rings, PL 94, fig. 14) or parallel and vertical (Lithotympaniim, with two equal rings, PL 83, fig. 1). The shell of the latter assumes the form of a drum. A third small subfamily, Dyst}Tnpanida, is represented by a single genus only, Dystympanuim (PL 94, figs. 15, 16). Here only the upper or mitral ring is closed by lattice-work, whilst the lower or basal ring exhibits a quite simple opening, a large " basal gate " which has probably arisen by loss of the basilar rod of the sagittal ring. These curious forms exhibit a remarkable resemblance to some Monocyrtida, and also to the Dictyocha (Ph.-eodaeia). The fourth sul)family, the Eutympanida, are distinguished by the simple wide aperture of the two horizontal rings; the upj)er enclosing a simple " mitral gate," the lower a simple " basal gate." Here probably the two horizontal parts of the sagittal ring (the upper mitral rod and the lower basilar rod) are lost by reduction ; its two vertical parts (the dorsal and ventral rods) only remaining and forming the two paraUel columeUse, which connect the two horizontal rings [Parastephcmus, PL 93, fig. 21). In this group also secondary columeEse are commonly developed between the two rings, alternating with the two primary columellse. Pseudocubus (PL 94, figs. 11, 12), resembling an obelisk, exhibits four divergent columellse ; the two sagittal of these are probably the vertical parts of the primary ring, whilst the two lateral are the halves of an incomplete frontal ring. In Lithocuhus (PL 82, fig. 12) the four columella are parallel and vertical, the two rings being equal ; the shell here assumes the form of a geometrical cube. Prismatium is distinguished by three paraUel columellse ; two of these are j)robably parts of a frontal ring, whilst the third is the remains of a reduced sagittal ring. In Circotympanum (PL 94, fig. 17) and in Lithotympanum (PL 82, fig. 1 1) the number of the columeUse is augmented, there being six to eight or more ; in the former they are divergent 990 THE VOYAGE OF H.M.S. CHALLENGER. (the two rings being of diiferent sizes), in the latter parallel (the two rings being equal) ; the fundamental form of the former is a truncated pjn^amid, of the latter a prism. Comparing these differences between the four subfamilies of Tympanida, we may suppose that the common ancestral group are the Protympanida, derived from the Semantida by the formation of a mitral ring. If the two horizontal rings become closed by lattice-work, the Paratympanida arise. When the mitral ring only becomes latticed, the basal ring being simple, the Dystympanida originate. Finally, the fourth subfamily, the Eutympanida, may be derived from the Protympanida by the loss of the two horizontal parts of the sagittal ring. The two horizontal rings (upper mitral and lower basal) and the two vertical rings (primary sagittal and secondary frontal), which thus compose the loose framework of the T}Tnpanida, are rarely smooth, commonly armed with spines or branches, similar to those of the Coronida. The rods or bars are either roundish (with circular transverse section) or angular (commonly with triangular transverse section). The paired branches of the two vertical rings often preserve the characteristic arrangement inherited from the Semantida and Stephanida. The two horizontal rings sometimes exhibit typical apophyses, which recur in the Spyroidea and C5^rtoidea. The mitral ring may possess one odd apical horn and two paired frontal horns (PI. 93, figs. 16, 17, 19, 23). The basal ring sometimes bears the three typical feet of Cortina (PI. 93, figs. 16, 22), one odd caudal foot and two paired pectoral feet. Sometimes a fourth (sternal) foot is developed (PI. 94, fig. 4), at other times only two lateral feet (PL 94, figs. 5, 6). Synopsis of the Genera of Tympanida. I. Subfamily Protympanida. Two horizontal rings (upper mitral ring and lower basal ring) bi- sected by the complete sagittal ring. II. Subfamily Paratympanida. Two horizontal ring fenestrated. Two horizontal rings con- nected by two columella. Two hori- zontal rings connected by four columellre (the halves of the sagittal and the frontal ring). No equa- torial ring. An equa- torial rinjr. Two horizontal rings con- nected by six or eight columeUce (three or four vertical rings). One complete sagittal ring (no frontal ring), No galear and thoracal bows, . Galear and thoracal bows, . ( Equatorial ring complete, . { Equatorial ring incomplete, f Six columella (three meri- I dional rings), Two horizontal rings closed by a lattice-jjlate, con- nected by numerous columellas. Eight columelte (four meri- dional rings), Two rings unequal (colu- mellee divergent), I Two rings equal (columella; [ parallel), 425. Protymjpanium. 426. Acrocuhus. 427. Toxarium. 428. Microcuhus. 429. Odotijmpanum. 430. Tympaniscus. 431. Tympanidium. 432. Paratijmpannm. 433. Lithotympanmn. REPORT ON THE RADIOLARIA. 991 III. SubfamHy Dystympanida. Mitral ring fenestrated, basal ring simple. Two horizontal rings con- nected by numerous (six IV. Subfamily Eutympanida. Two horizontal rings (upper mitral ring and lower basal ring) simple. Apical and basal parts of the sagittal ring lost. Mitral ring closed by a lat- to eight or more co mellaj). J , ' V tice-plate, basal simnlfl, . simple. Two horizontal rings con- nected by two or three columellaj (four or five open gates). Two horizontal rings con- nected by four or more columellas (six or eight or more open gates). Two columellse (parts of the sagittal ring), Three columella; (parts of the half sagittal and the frontal ring), Four colu- mella. Six to eight or more columeUEe. Two rings unequal, Two rings equal, . Two rings unequal. Two rings equal, 434. Dystympanium. 435. Parastejjlianus. 436. PrismaHiim. 437. Pseudoeiibus. 438. Lithocuhus. 439. Circotympanum. 440. Eutympanium. Subfamily 1. Protympanida, Haeckel. Definition. — T y m p a n i d a with two bisected horizontal rings, connected by the complete vertical sagittal ring. (The upper mitral ring and the lower basal ring become divided by the complete primary or sagittal ring into two horizontal symmetrical gates, two mitral gates on the apical and two basal gates on the basal pole.) Genus 425. Protynipanium,^ Haeckel, 1881, Prodromus, p. 447 {sensu emend.). Definition. — T y m p a n i d a with two bisected horizontal rings, connected by two vertical columellse. The genus Protympanium is the most simple form of all Tympanida, and probably the common ancestral form of this family. It arises from Litliocircus by the develop- ment of two horizontal rings, perpendicular to the primary sagittal ring. The upper or mitral ring arises by lateral union of two pairs of superior branches, the lower or basal ring by union of two pairs of basal branches of the primary vertical ring. 1. Protympanium primordicde, n. sp. Mitral and apical ring of equal size, elliptical, smooth, somewhat smaller than the connecting thorny sagittal ring. Dimensions. — Diameter of tlie two horizontal rings 0T2, of the sagittal ring 015. Ecibitat. — Central Pacific, Stations 263 to 274, at various deptlis. 1 Pro<2/™paMiM7ft= Primordial drum; •Tr^orvfi'zaiiiau. 992 THE VOYAGE OF H.M.S. CHALLENGEE. 2. Protympanium amphipodium, n. sp. (PI. 93, fig. 14). Mitral and apical rings of equal size, thin, elliptical, smooth, larger than the broad connecting sagittal ring. The latter bears on the apical and on the basal pole two divergent straight spines (lying in the frontal plane), the two apical (or horns) somewhat smaller and not so spiny as the two basal spines (or feet). In the frontal plane there arise from the two horizontal rings on each side two small opposite spines (remnants or beginnings of the lateral frontal ring ?). Dimerisions. — -Diameter of the two horizontal rings O'll, of the sagittal ring 0'07. Habitat. — Central Pacific, Station 27l, depth 2425 fathoms. 3. Protympanium trissocircus, n. sp. Mitral ring smaller than the basal ring ; both rings circular, rough. Sagittal ring in size between the two former. All three rings covered with very small thorns. Dimensions. — Diameter of the mitral ring 0"08, of the sagittal ring 01, of the basal ring 0-12. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. Genus 426. Acrocuhus,^ Haeckel, 1881, Prodromus, p. 447. Definition. — T y m p a n i d a with two bisected horizontal rings, connected by four vertical columellse. No equatorial ring. The genus Acrocubus is the most primitive of those remarkable Tympanida, the .skeleton of which represents more or less exactly the form of a geometrical cube. A simple complete sagittal ring bears on the superior and on the inferior part two opposite pairs of lateral branches ; by union of the convergent branches of each side there arise two horizontal parallel quadrangular rings, which are bisected by the sagittal ring. There- fore the superior ring encloses two triangular mitral gates, the inferior two triangular basal gates. The lateral corners of the two gates of each side are connected by a vertical rod or columella. These two parallel columellse are the remaining middle parts of the secondary or frontal ring, which is incomplete on the superior and on the inferior face of the body. If the sagittal ring also become incomplete, by the loss of the superior and inferior part (the anterior and posterior only remaining), then Acrocubus is .transformed into Lithocubus. Subgenus 1. Apocubus, Haeckel. Definition. — Basal ring without descending feet. ^ ^crocM6tw = Perfect culie ; axjo?, xi/,3of. REPORT ON THE RADIOLARIA. 993 1. Acrocubus octopylus, u. sp. (PI. 82, fig. 9). Mitral ring somewhat smaller than the basal ring ; both rings rhombic, with curved outlines. Sagittal ring elliptical, with six pairs of nodnlate protuberances. Four columelliE curved. Nodal points without radial spines. Dimensions. — Height of the frontal ring 012, breadth 0'18. Habitat. — ^Western Tropical Pacific, Station 225, depth 4475 fathoms. 2. Acrocubus tesseralis, u. sp. Mitral ring of the same size as the basal ring; both rings square, smooth, with straight outlines. Sagittal ring also square, smooth. Four columellse straight. Nodal points without radial spines. The shell has the form of a regular geometrical cube, the edges of which are represented by the rings. Dimensions. — Height of the frontal ring 01, breadth Oil. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. Subgenus 2. Dipocubus, Haeckel. Definition. — Basal ring with two descending feet. 3. Acrocubus brachiatus, n. sp. Mitral ring smaller than the basal, both rings square, with thick straight rods. Sagittal ring- tuberculate, square, equatorial part thinner. Four columellie curved, the two lateral ones prolonged downwards into two vertical parallel straight feet of half their length. Dimensions. — Diameter of the cube 012 ; length of the feet 0'06. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 4. Acrocubus amphistylus, n. sp. Mitral and basal rings of nearly equal size, square, with thick curved rods. Sagittal ring eUiptical, in the equatorial part thinner. Frontal ring tuberculate. Four columellce curved, the two lateral ones prolonged downwards into two vertical, tubercidate feet of half theii" length. Dimensions. — Diameter of the cube 013 ; length of the feet 0'07. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 5. Acrocubus arcuatus, n. sp. (PI. 93, fig. 15). Mitral and basal rings, as well as the sagittal ring, of the same form as in the jareceding nearly allied species. The two lateral columellte are prolonged not only downwards into two short (ZOOL. CHALL. EXP. PART XL. — 1886.) Kf 125 994 THE VOYAGE OF H.M.S. CHALLENGER. vertical feet, but also upwards into two curved bows, which are united in a vertical ascending horn, arising from the apical pole of the sagittal ring. Dimensions. — Diameter of the culje 014 ; total height 0-21. Hcibitat. — Central Pacific, Station 265, depth 2900 fathoms. Subgenus 3. Tnj^ocuhus, HaeckeL Definition. — Basal ring with three descending feet (one odd caudal and tvi^o paired lateral). 6. Acrocuhiis lasanum, n. sj). Mitral ring smaller than the liasal, both rings square, with curved rods. Sagittal ring ovate, prolonged upwards into an occipital simple horn, downwards into a caudal foot. Two lateral columella? prolonged downwards into two pectoral feet. All three feet conical, about as long as the height of the cube. Dimensions. — Diameter of the cube 0"08 ; length of the feet 0"07. Hahitat. — North Pacific, Station 241, depth 2300 fathoms. 7. Acrocuhus corlina, n. sp. (PL 93, fig. 16), Mitral ring smaller than the basal, both rings elliptical, with curved rods. Sagittal ring ovate, prolonged upwards into an occipital horn, downwards into a caudal foot, as in the preceding species. As in the latter, also, the two lateral columella? are prolonged downwards into two pectoral feet, but also upwards into two convergent horns, which are united with the occipital horn (commencing the formation of a galea). Eings and feet somewhat thorny. Dimensions. — Diameter of the cube 016 ; total height 0'2. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. Subgenus 4. Tetracuhus, HaeckeL Definition. — ^Basal ring with four descending feet (two sagittal and two lateral). 8. Acrocuhus tetrapodius, n. sp. ' Mitral and basal rings of the same size, square, with straight rods, sagittal ring also square. The four vertical columellce are nearly parallel and straight, prolonged upwards into four short conical horns, downwards into four longer conical feet. (The shell has nearly the form of a geometrical cube, the eight corners of which are prolonged into eight vertical conical spines, four smaller ascending and four larger descending.) Dimensions. — Diameter of the cube 0"09 ; length of the feet 0'06. Hahitat. — South Atlantic, Station 332, depth 2200 fathoms. REPOET ON THE RADIOLAEIA. 995 9. Acrocuhus amphithectus, u. sp. (PI. 93, fig. 17). Mitral ring smaller than the basal, both rings elliptical, with curved rods. Four columellse tliorny, also curved, divergent downwards, prolonged upwards into four thorny convergent horns, downwards into four larger branched divergent feet. The two sagittal horns and feet (anterior and posterior) are smaller than the two lateral (right and left) ; therefore the fundamental form of tliis species is distinctly amphithect (as in the Ctcnophora). Dimensions. — Breadth of the cube 012 ; total height 0'2. Hahitat. — South Pacific, Station 289, depth 2550 fathoms. Genus 427. Toxarium,^ n. gen. Definition. — T y m p a n i d a with two bisected horizontal rings, connected by four vertical columellee. In the frontal plane two galear bows project upwards, and two thoracal bows downwards. The genus Toxarium differs from its ancestral form Acrociibus in the development of two pairs of peculiar bows, placed in the lateral or frontal plane ; the upper pan- projects above the mitral gates, and may be called the " galear bows," the lower pair projects below the basal gates of the cubical shell, and may be called the " thoracal bows." Both pairs are produced originally by the development of two forked vertical spines, arising in the frontal plane on both poles of the priuci25al axis from the sagittal ring (compare Protympanium amphipodium, PL 93, fig. 14). The apical fork- branches become connected ^Adth the lateral corners of the mitral gates, the basal branches with those of the basal gates. By development of lattice-work between the bows and the rings some Spyroidea {Amphispyris, &c.) may have arisen. The important genus Toxarium may be divided into three subgenera. In Toxellium aU the bows are simple, in Toxonium all are forked ; in Toxidium the galear bows are simple, the thoracal bows forked. Subgenus 1. Toxellium, Haeckel. Definition. — Galear and thoracal bows simple. , 1. Toxarium circospyris, n. sp. (PI. 88, fig. 1). Galear and thoracal bows simple, of about the same size as the frontal bows between them ; all bows armed with scattered simple conical spines. Sagittal constriction deep, half as long as the whole shell. Lateral outlines of the shell nearly parallel. Binicnsions. — Length of the shell 0'16, breadth 0'13. Habitat. — Central Pacific, Stations 265 to 274, depth 2350 to 2925 fathoms. ' roxa?'i!tjn = Small bow ; 7-o|«g/(r«or. (ZOOL. CHALL. EXP. — PAET XL. — 1886.) Kr 126 1002 THE VOYAGE OF H.M.S. CHALLENGER. 4. Tym/paniscus tripodiscus, n. sp. (PL 94, fig. 7). Basal ring of about the same size as the mitral riug, with three large and stout divergent feet (two lateral and one caudal). Sagittal ring stout, broader than the two spiny subsagittal rings ; the upper part of the latter bears two ascending arches, which are united with the large apical horn arising from the apex of the sagittal ring. Six columella nearly vertical, slightly curved on the outside ; their lateral edges armed with numerous simple or forked spines. Dimensions. — Breadth of the shell O'l, total length 0'12. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 5. Tympaniscus qtiadrupes, n. sp. (PL 94, fig. 4). Basal ring larger than the mitral ring, with four short vertical three-sided pyramidal feet of equal size (two lateral and two sagittal) ; the feet are three-sided pyramidal, with finely denticulate median edges, and bear at the base a horizontal thorny spur. Sagittal ring at the apex with a very large cross-shaped horn, bearing two horizontal thorny lateral branches ; the horn is supported by an anterior and a posterior arch. Six columella; strongly curved and dentate. Dimensions. — Breadth of the shell 015, length 012. Habitat. — South Pacific, Station 298, depth 2225 fathoms. 6. Tympaniscus fibula, HaeckeL Ceratospijris fibula, Ehrenherg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xx. fig. 3. Basal ring of about the same size as the mitral ring, with six large conical descending feet; these are prolongations of the six columellae, nearly of the same length, slightly divergent, and bear at the base a strong horizontal spur. The six columellae are strongly curved, spiny, and bear above small arches, which are united with the apical horn of the sagittal ring. Dimensions. — Breadth of the shell 0'09, height 0'05 ; total height 0'09. Habitat. — Fossil in Barbados. 7. Tympaniscus dodecaster-, n. sp. Basal ring of the same size as the mitral ring, with six very large and six alternating smaller, slightly divergent, curved feet, about as long as the shell ; the larger are the basal prolongations of the six curved, thorny columellije. Mitral ring spiny, not overgrown with arches, as in the similar preceding species. Dimensions. — Length of the shell 0"08, breadth 012. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. REPORT ON THE RADIOLARIA. 1003 Geuus 431. Tympanidium,'^ Haeckel, 1881, Prodi-omus, p. 447. Definition. — T y in p a n i d a with two bisected horizontal rings, which are connected by four vertical meridional rings (or eight columellse). The genus Tymjoanidium differs from all other Protympanida in the development of four vertical rings, placed in four different meridional planes. Only one of these is complete, the primary sagittal ring ; the three others are incomplete, inserted on the two horizontal rings, which are formed by the paii-ed mitral and basal branches of the sagittal ring ; one of these three lies in the frontal plane, the two others in diagonal meridional planes (between the frontal and sagittal). The shell therefore exhibits twelve large gates, four of which are horizontal (the two superior mitral and the two inferior basal gates) ; the eight others are vertical, separated by the eight columellse, or the halves of the four meridional rings. In the subgenus Tympanomma the number of gates amounts to sixteen, the four lateral gates being bisected by an incomplete equatorial ring. The genus Tympanidium may be derived from Acrocuhus by development of the two diagonal rings (between the frontal and sagittal). Subgenus 1. Tympanura, Haeckel. Definition. — Shell with twelve gates ; the four lateral gates simple. 1. Tympanidium foUosum, n. sp. (PL 94, fig. l). Shell with twelve gates ; the four lateral gates simple. Basal gates of the shell larger than the mitral gates. Sagittal ring ovate, much smaller than the three other meridional rings, which are armed with numerous large elegant spines, bearing a lanceolate leaf on a thin pedicle. The sagittal ring bears a bunch of similar spines only at the apex, and on both poles of the sagittal axis (in the equator) a single forked spine, with two thorny branches. Dimensions. — Length of the shell 0'09 (with spines 0'25), breadth 0'15. Habitat. — South Pacific, Station 300, depth 1375 fathoms. 2. Tympanidium spinosum, n. sp. Shell with twelve gates ; the four lateral gates simple. Basal and mitral gates of about equal size. Shell similar to that of the preceding species, differing mainly in the different armature ; the numerous spines, covering the convex outside of the four vertical rings, are not leaf-shaped, but conical, short, of very variable size, partly simple, partly irregularly branched. Dimensions. — Length of the shell 0-08 (with spines 0-2), breadth 012. Habitat. — South Pacific, Station 295, depth 1500 fathoms. 1 Tympanidium = 'S:\i\sl\ drum ; Ti/^xan'S/oi/. 1004 THE VOYAGE OF H.M.S. CHALLENGER. Subgenus 2. Tympanomma, Haeckel. Definition. — Shell with sixteen gates (eight median gates, paired on both sides of the sagittal ring, and eight lateral gates, j^aired on both sides of the frontal ring). The four lateral gates of the two preceding species (subgenus Tympanura) are bisected in Tympanomma by the lateral parts of an incomplete equatorial ring. 3. Tympanidium binoctonum, n. sp. (PI. 94, fig. 18). Shell with sixteen gates ; the four lateral gates double, bisected by the lateral parts of an incomplete equatorial ring. Basal gates nearly rectangular, of the same breadth as the pentagonal mitral gates, but twice as long. Equatorial outline of the shell (seen in fig. 18 from the apical pole) octagonal. All rods of the shell thin, smooth. Dimensions. — Transverse axis of the shell 0-1, sagittal axis 0"06. Sabitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 4. Tympanidium barhadense, Haeckel. "Hollow cyliuder," &c., Bury, 1862, Polycystins of Barbados, pi. xvi. fig. 1. Shell with sixteen gates ; the four lateral gates double, bisected by an incomplete equatorial ring. Basal gates kidney-shaped, of the same breadth as the circular mitral gates, but twice as long. Equatorial outline of the shell elliptical. All rods of the shell thin, smooth. Dimensions. — Transverse axis of the shell 012, sagittal axis 0'08. Habitat. — Fossil in South Naparima, Trinidad, Barbados. 5. Tympanidium staurocircum, n. sp. Shell with sixteen gates ; the four lateral gates double, bisected by an incomplete equatorial ring. Basal and mitral gates of the shell of about equal size, roundish. Equatorial outline of the shell xiolin-shaped, with a sagittal constriction. All rods of the shell armed with short irregular spines. Dimensions. — Transverse axis of the shell 012, sagittal axis 0-06. Habitat. — ^Tropical Atlantic, Station 347, depth 2250 fathoms. Subfamily 2. Paratympanida, Haeckel, 1881, Prodromus, p. 447. Definition. — T y m p a n i d a with two fenestrated horizontal rings, which are connected by a variable number of vertical rods or columellas. The shell therefore becomes more completely latticed than in the other Tympanida, and approaches that of the S p 5^ r 0 i d e a. REPORT ON THE RADIOLARIA. 1005 Genus 432. Paratijmpanum,'^ Haeckel, 1881, Prodi'omus, p. 447. Definition. — Tympauida with two latticed horizontal rings, connected by numerous descending and diverging columellse ; mitral ring smaller than the basal ring. The genus Paratympanum and the following nearly allied Lithotympanum form together the small subfamily of Paratympanida, distinguished from the other Tympanida by the fenestration of the two parallel horizontal rings. These rings in Lithotympanum are both equal, whUst in Paratympanum the basal ring is larger than the mitral ring ; therefore the connecting rods or columellte are in the former parallel and vertical, in the latter divergent and descending. Two opposite ones of these columellse are parts of the primary sagittal ring, two others are parts of the lateral or frontal ring, whilst the remainder are afterwards intercalated. Paratympanum may be derived from Dystym- panium by fenestration of the basal ring. 1. Paratympanum hexastylum, n. sp. Six divergent columellfe, about as long as the diameter of the hexagonal mitral ring, connect it with the larger hexagonal basal ring. Lattice of the mitral ring hemispherical, with six roundish pores, sui-rounding a central apical horn. Lattice of the basal ring with one large central pore, surrounded by numerous peripheral pores. Eiugs and rods smooth, without spines. Dimensions. — Length of the shell O'OV ; breadth of the mitral ring 0'06, of the basal ring 0-09. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Paratympanum octostylum, n. sp. (PL 94, fig. 14). Eight divergent columella, about as long as the diameter of the octagonal mitral ring, connect it with the larger circular basal ring, and bear at each end a divergent, strong, conical spine. Lattice-plate of both rings slightly convex, with numerous subregular circular pores, smooth, without surface spines. Dimensions. — Breadth of the mitral ring 0'06, of the basal ring 0'09. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 3. Paratympanum decastylum, n. sp. Ten divergent columella, only half as long as the diameter of the decagonal mitral ring, coimect it with the larger circular basal ring. Lattice-plate of the mitral ring nearly hemispherical of the basal ring flat, both with numerous irregular roundish pores and scattered Opines. Margin of both rings spiny. Dimensions. — Breadth of the mitral ring 0'08, of the basal ring 01. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 1 Paratympanum = Side-dTnrri ; x«fai, Tvftvui^o'j. 1006 THE VOYAGE OF H.M.S. CHALLENGER. Genus 433. LitJwtympanum,^ Haeckel, 1881, Prodromus, p. 447. Definition. — T y m p a n i d a with two latticed horizontal rings, connected by numerous parallel and vertical columellse ; mitral and basal rings of equal size. The genus Lithotympanum has the form of a cylindrical drum, the two fundamental faces of which (the mitral and basal gates) are closed by lattice-work. Both horizontal rings are equal, whilst in the preceding Paratympanum the basal gate is larger than the mitral. It may be derived from the latter by equalisation of these two rings, or directly from Dystym'panium by fenestration of the basal ring. 1. Lithotympanum tuberosum, n. sp. (PL 83, fig. 1). Both lattice-plates slightly convex ; the mitral plate with six larger marginal pores and one central pore separated by numerous smaller pores ; the basal plate with seven large pores only (one central and six peripheral). Surface and margin of the plates uneven, with roundish prominent dimpled tubercles. Both rings connected by ten to twelve simple cylindrical vertical columella;. Dimensions. — Length of the shell 013, breadth 0"1. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 2. Lithotympanum spinosum, n. sp. Both lattice-plates flat, with numerous irregular roundish pores of variable size. Surface thorny. Margin with numerous irregular spines, directed upwards on the mitral, downwards on the basal plate. Both rings connected by eight simple cylindrical vertical columella;. Dimensions. — Length of the shell 0'12, breadth 0'08. Habitat. — Western Tropical Pacific, Station 224, depth 1850 fathoms. Subfamily 3. Dystympajstida, Haeckel. Definition. — T y m p a n i d a with fenestrated mitral ring and simple open basal ring ; both horizontal rings connected by numerous vertical or divergent columellse. Genus 434. Dystympanium,^ n. gen. Definition. — Tympanida with two horizontal rings, connected by numerous (six to eight or more) divergent columellse. The upper mitral ring is smaller and latticed, the lower basal ring larger and open. ^Lithotyrrvpanum—Dvu.moisilex; Ai'^fos, ti//anium distephanus, n. sp. Basal ring hexagonal, with six larger spines at the six corners, and numerous smaller ones between them. Mitral ring half as broad as the basal ring, also with six angular spines. The latter are connected with the former by six divergent curved columellse, about as long as the diameter of the basal ring. Mitral lattice-plate ilat, with irregular roundish pores. Dimensions. — Diameter of the basal ring 01, mitral ring 0'05 ; length of the columeUse 0'09. Habitat. — Equatorial Atlantic, Station 347, depth 2250 fathoms. 3. Dystympanium medusa, n. sp. Basal ring circidar, with eight larger and niuuerous smaller divergent spines. Mitral ring two- thirds as broad as the basal I'ing, octagonal, with eight conical ascending spines on the eight corners. The latter are connected with the former by eight divergent, curved columeUae, as long as the diameter of the mitral ring. Mitral lattice-plate nearly hemispherical, with nine circidar pores (eight peripheral pores around one central pore). Dimensions. — Diameter of the basal ring 012, mitral ring 0'08 ; length of the columellte 0'09. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. Subfamily 4. Eutympanida, Haeckel. Definition. — T ympanida with two simple horizontal rings, which ai'e connected by a variable number of vertical rods or columeUse. Therefore the shell exhibits a large simple mitral gate on the upper, and a large simple basal gate on the lower side; between the two a variable number of lateral gates. 1008 THE VOYAGE OF H.M.S. CHALLENGER. Genus 435. Parastephanus, Haeckel, 1881, Prodromus, p. 446. Definition. — T y m p a n i d a with two simple horizontal rings, connected by two vertical columellse. The o-enus Parastephanus is the simplest among the Eutympanida, and exhibits only two vertical rods or columellse, which connect the two parallel horizontal rings. One of these latter must be regarded as the mitral or superior ring, the other as the basal or inferior ring ; whilst the two parallel columellse, connecting both, are the remaining vertical parts of the sagittal ring, the upper and lower parts of which are lost. By loss of the latter Parastephanus has probably been derived from Protympanium. 1. Parastepha7ius circularis, n. sp. Two horizontal rings smooth, circular, of equal size, connected by two curved smooth columelkc, which are somewhat shorter than the diameter of the rings. Dimensions. — Diameter of the rings 008, length of the columellse 0'06. Habitat. — Central Pacific, Station 263, depth 2650 fathoms. 2. Parastephanus quadrispinus, n. sp. (PL 93, fig. 21). Two horizontal rings smooth, elliptical or nearly circular, of equal size, connected by two vertical, slightly curved columellas, which are about as long as the radius of the rings. Each ring bears two simple lateral spines, which in the mitral ring are curved downwards, in the basal ring upwards, possibly the last remains of a reduced frontal ring. Dimensions. — Diameter of the rings 0-09, length of the columellse 0'05. Habitat. — North Pacific, Station- 236, surface. 3. Parastephanus asymmetricus, n. sp. (PI. 82, fig. 10). Two horizontal rings thorny, of equal size, irregularly ovate or nearly semicircular, and of some- what asymmetrical form. The two connecting parallel columellffi are straight, cylmdrical, about as long as the diameter of the rings. The peculiar asymmetry in the form of the rings raises the possibility that the two columelke in this species are the remaining parts of a frontal ring, and that the sagittal ring has altogether disappeared. In this case the convex half of both rings would be the ventral, the straight half the dorsal part. Dimensions. — Diameter of the rings 01, length of the columeUse 0'08. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. REPORT ON THE RADIOLARTA. 1009 4. Parastejihctnus disjyar, n. sp. Two horizontal rings elliptical, thorny, of different sizes, the basal ring one and a half times as broad as the mitral ring. The two connecting columellffl are curved, somewhat longer than the diameter of the mitral ring. IHmensions. — Diameter of the basal ring 0'09; mitral 0-06 ; length of the columellffi 0"07. Habitat. — South Pacific, Station 300, depth 1375 fathoms. Genus 436. Prismatium,^ Haeckel, 1862, Monogr. d. Radiol., p. 270. Definition. — Tympanida with two simple horizontal rings, connected by three vertical columellse. The genus Prismatium was hitherto the only known form of the Tympanida, and the only species described in 1862 in my Monograph was Prismatiutn tripleurum {loc. cif., p. 270, pi. iv. fig. 6), A new species from the Challenger collection (PL 93, fig. 22), Prismatium tripodium, explains the true structure of this remarkable genus. The skeleton is composed of nine siliceous rods, corresponding to the edges of a trilateral prism. Six of these are horizontal, and enclose the two parallel triangular horizontal gates, the superior of which is formed by the mitral or coryphal, and the inferior by the basal or cortinar ring. The three other rods are vertical and nearly parallel, and connect (as lateral edges of the prism) the corresponding corners of the two parallel horizontal triangles. Two of these vertical columellse, together with the two horizontal parallel rods connecting them, represent the complete frontal ring, whilst the third vertical columella is the posterior half of the sagittal ring, the other parts of which are lost. 1. Prismatium tripodium, n. sp. (PI. 93, fig. 22). Mitral ring triangular, somewhat smaller than the triangular basal ring, both connected at the corners by three vertical, slightly curved columeUse. From the six corners arise six radial spines of different size and form ; the two paired spines of the mitral ring are simple and very small, whilst those of the basal rmg are three times as long and bear a lateral branch. The odd spine of the third corner is on lx)th rings larger, and distingui.shed by some thorns. This difference seems to indicate that these two odd spines correspond to the apical horn and the caudal foot of Cortina, and the eolumella between them is the rest of the reduced sagittal ring. In this case the quad- rangular vertical ring, which is composed of the two paired columeike and the two connecting horizontal rods, would be probably the frontal ring. Dimensio7is. — Length of the .shell 0'09, breadth 0'07. HaMtat. — Equatorial Atlantic, Station 347, surface. ' Prisraatium = A. small prism ; vqtniecittot. (ZOOU CHALL. EXP. PART xu — 1886.) Er 127 1010 THE VOYAGE OF H.M.S. CHALLENGEE. 2. Prismatium tripleurum, Haeckel. PrUmatluni tripleurum, Haeckel, 1862, Monogr. d. Radiol., p. 270, Taf. iv. fig. 6. Acanthodesmia prismatium, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 799. Mitral and basal rings of equal size, equilateral triangular, both connected at the corners by three vertical equal columella. From the six comers arise six short, equal, conical radial spines. The nine rods of the shell correspond to the nine edges of a triangular equilateral prism. Dimc-nsions. — Length of the shell 0'044, breadth 0-032. Habitat. — Mediterranean (Messuia), surface. Genus 437. Pseudocubus,^ n. gen. Definition. — Tympanida with two simple horizontal rings of different sizes, connected by four divergent columellse. The genus Pseudocuhus exhibits the characteristic form of an obelisk, or a truncated four-sided ^^yramid. The four edges of this obehsk, or the four " columellse," are the remaining parts of the two incomplete vertical rings ; two opposite edges are the dorsal and ventral rod of the sagittal ring ; the two alternate edges between these are the lateral rods of the frontal ring. The two horizontal rings, which become connected by the four divergent columellte, are the smaller mitral ring and the larger basal ring ; both are either square or nearly circular. 1. Pseudocuhus oheliscus, n. sp. (PL 94, fig. 11). Mitral ring square, with circular gate and two divergent simple spines on each corner. Basal ring twice as broad, square, with four convex sides and one simple spine on each corner. Four columellEe straight. All twelve rods with three smooth edges. Dimensions. — Breadth of the mitral ring 0'02, of the .basal ring 0'05. Halitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Pseudocuhus octostylus, n. sp. • Mitral ring square, with one stout pyramidal spine on each corner. Basal ring twice as broad, square, also with a single strong spine on each corner. Four columella; straight. All twelve rods with three smooth edges. Dimensions. — Breadth of the mitral ring 0'04, of the basal ring O'OS. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 1 Pseudocubiis=T'ahe cube ; \f sJoo;, x5,3o;. REPORT ON THE RADIOL ARIA. 1011 3. Pseudociihus hexajrylus, n. sp. (PI. 94, fig. 12). Mitral ring circular, two-thirds as broad as the subcircular, or nearly square, basal ring ; both rings with a simple spine on the two sagittal corners (dorsal and ventral), with a forked or branched larger spine on the two lateral corners (right and left). All twelve rods more or less curved and thorny. Dimensions. — Breadth of the mitral ring 0'07, of the basal ring O'l. Ealitat. — Central Pacific, Station 272, depth 2600 fathoms. Genus 438. Lithocubus,^ Haeckel, 1881, Prodromus, p. 447. Definition. — T y m p a n i d a with two simple horizontal rings of equal size, connected by four parallel vertical columellaj. The genus LitJiocuhus is very remarkable for the regular cubical form of the skeleton, which is composed of twelve siliceous rods, corresponding to the twelve edges of a cube. Eight of these are horizontal, and enclose the two parallel square horizontal gates, the superior mitral and the inferior basal gate. The four other rods are vertical, parallel, and connect (as lateral edges of the cube) the corresponding corners of the two horizontal squares. Two opposite ones of these four vertical columellse are the remaining halves of the incomplete sagittal ring ; the two alternate are the remaining halves of the incomplete frontal ring. The four lateral gates between these four columellse are also square or rectangular, and either of the same size as the two horizontal gates, or some- what larger. Lithocubus may be derived from Acrocubus by reduction of the coryphal and the basal part of the primary sagittal ring, the only remaining parts of which are the anterior and the posterior columellse. 1. Lithocubus geometricus, n. sp. (PI. 94, fig. 13). The twelve rods, corresponding to the edges of the geometrical cube, are straight and smooth ; the eight corners provided with a smaU conical thorn. The shell exhibits six equal square sides, and represents therefore exactly the geometrical form of a cube. Dimensions. — Diameter of the cube 0'05 ; thickness of the bars 0"008. Hahitat. — -Tropical Pacific, Station 224, depth 1850 fathoms. 2. Lithocubus octacanthus, n. sp. The twelve rods of the cubical shell are shghtly curved, convex, smooth, as in the similar preceding species. It differs from that in the development of eight slender radial spines, arising from the eight corners of the geometrical cube, from two to three times as long as its diameter, and lying opposite in pairs in its diagonals. Dimensions. — Diameter of the cube 0"06 ; length of the spines 0"15. Habitat. — North Atlantic, Canary Islands, surface. ^ Lithocubus=C\i\ie oi silex; 'kih;, xifios. 1012 THE VOYAGE OF H.M.S. CHALLENGEE. 3. Lithocuhus vinculatus, Haeckel. Aeantlutdesmia vincuJata, J. Miiller, 1856 (jmrtim), Abhandl. rl. "k. Akad. d. Wiss. Berlin, Taf. i. fig. 7 (not 4-6). The twelve rods of the cubical shell are curved and armed with scattered, simple, short spines. Tlie figure 7 of Johannes Miiller {loc. cit.) corresponds exactly to the Mediterranean form observed by me at Portofino, and is quite different from his true AcantJiodesmia vinculata {he. cit, figs. 4—6), so that I have no doubt he did observe these two different species (compare above, p. 9.75). Dimensions. — Diameter of the cube 0"07 ; length of the spines 0-O2. Habitat. — Mediterranearu (Nice, Portofino). 4. Lithocubus astragalus, n. sp. (PI. 82, fig. 12). The twelve rods of the cubical shell are stout and slightly curved, armed with numerous, simple, and irregularly branched spines. Eight larger spines, branched like a deer's antler, arise from the eight corners of the cube. Dimensions. — Diameter of the cube 0"1 to 012 ; length of the corner spines 0'05 to 0'08. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 439. Circotympanum,^ n. gen. Defimtion. — Tympanida with two simple different horizontal rings, connected by numerous (six to eight or more) divergent columellse. The genus Circotymjmiium comprises those Tympanida in which two simple hori- zontal rings of different size (an upper smaller " mitral ring," and a lower larger " basal ring ") are connected by a variable number of divergent rods or columellse (at least six or eight). Oircotympanum is probal^ly derived from Tympaniscus or Tympanidium by partial reduction of the sagittal ring, the upper (apical) and lower (basal) part of which is lost. The geometrical fundamental form is a truncated pyramid with six to eight or more edges. • o^ 1. Circotympamtm hexagonium, n. sp. Mitral and basal ring hexagonal, the latter twice as broad as the former, each with a simple siuall spiiie on the six corners. Six columellffi nearly straight, as long as the radius of the basal ring. All rods with three prominent edges. Dimensions. — Breadth of the mitral ring 0'06, of the basal ring Oil. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 1 Circotympanwrn = 1)11101 with rings ; x/(|xo;, zifiTravou. EEPOET ON THE RADIOLAEIA. 1013 2. Circot^jm'panum octogonium, n. sp. (PI. 94, fig. 17). Mitral and basal rings octagonal, the latter one and a half times as broad as the former. Ei'dit columellfe slightly curved, thorny. The mitral ring bears on each corner a short ascending spine, the basal ring a larger, thorny, obliquely descending spine, which has some recurved thorns on the upper edge. All rods more or less thoriiy. Dimensions. — Breadth of the mitral ring 0'06, of the basal ring 0"09. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 3. Clrcotympanum decagonium, n. sp. Mitral and basal rings circular, the latter nearly twice as broad as the foi-mer, both armed with scattered irregular thorns. Ten columellie smooth, curved. Dimensions. — Breadth of the mitral ring 0'O7, of the basal ring 012. Habitat. — North Pacific, Station 244, depth 2900 fathoms. Genus 440. Eiitynvpanium,^ Haeckel, 1881, Prodromus, p. 447. Definition. — T y m p a n i d a with two simple equal horizontal rings, connected by numerous (six to eight or more) parallel and vertical columellae. The genus Eutympantum contains those Tympanida in which the drum-shaped shell is composed of two simple, parallel and equal horizontal rings, and numerous vertical and parallel rods or columellee connecting them. The number of the latter is at least six or eight. Two opposite of these must be regarded as remaining vertical parts of the sagittal ring, t"wo others as parts of the fi'ontal ring, whilst the other columellse (between the former and the latter) are secondary and intercalated. Therefore Eutympanium may be derived from Tympanidium by reduction and loss of the apical and basal parts of the sagittal ring. 1. Eittymjmnium musicantum, n. sp. (PI. 83, fig. 2). Eight parallel and vertical columellte, simple, straight and smooth. Both horizontal rings equal, circular, each armed with eight to twelve short conical thorns. Dimensions. — Height of the shell 0'09, breadth 0'07. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 1014 THE VOYAGE OF H.M.S. CHALLENGER. 2. Eutymixinimn octonarium, n. sp. Eight vertical coluinelL'e slightly curved, thorny. Both horizontal rings equal, octagonal, each armed with eight large, irregularly-branched spines, which on the mitral ring are directed obliquely upwards, on the basal ring downwards. Dimensions. — Height of the shell 012, breadth 01. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 3. Eutympanium coronarium, n. sp. • Eight thorny columellse, obliquely descending and curved like a bow, divergent in the upper part, convergent in the lower. Basal ring circular, mitral ring octagonal. Both horizontal rings armed with eight stout thorny spines, which on the mitral ring are smaller and directed obliquely upwards, on the basal ring larger and directed downwards, each with a recurved hook. Dimensions. — Height of the shell 0"08, breadth 0'06. Habitat.— South Atlantic, Station 332, depth 2200 fathoms. 4. Eutympanium militare, n. sp. (PI. 82, fig. 11). Ten parallel and vertical columellje straight and smooth, cylindrical. Both horizontal rings equal, circular, armed with numerous short conical spines, divergent in all directions. Ten to twenty spines on each ring larger than the others. Dimaisions. — Height of the sheU 01, breadth 0'08. Habitat. — -Western Tropical Pacific, Station 225, depth 4475 fathoms. 5. Eutympanium dodecarium, n. sp. Twelve vertical columellse, slightly curved, smooth. Mitral and basal rings circular, both horizontal rings armed with twelve stout, irregularly-branched spines, which are prolongations of the columella, and on the mitral ring directed upwards, on the basal ring downwards. Dimensions. — Height of the shell 013, breadth 01. Habitat. — South Pacific, Station 300, depth 1375 fathoms. REPORT ON THE RADIOLARIA. 1015 Order VI. CYRTELLARIA, Haeckel, 1881. Definition. — Nassellaria -ftdth a complete lattice-shell enveloping the central capsule. Suborder I. SPYEOIDEA, Haeckel. Spyridina, Ehrenberg {pro parte), 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Zygocyrtida, Haeckel, 1862, Monogr. d. Radiol., p. 291. Zygocyrtida, Biitschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 501. Acanthodesmida, R. Hertwig, 1879, Organismus der Radiol., 'p. 68. Spyi'ida vel Spyroidca, Haeckel, 1881, Prodronius, jd. 440. Definition. — Nassellaria with a complete lattice-shell, exhibiting constantly a bilocular cephalis with a sagittal constriction. The suborder S p y r 6 i d e a, and the two following closely allied suborders, • Botryodea and C y r t o i d e a, represent together that large group of Radiolaria which I first described in my Monograph (1862, pp. 272, 280) as the family Cyrtida, but afterwards as a separate order (or sublegion) under the name Cyrtellaria (1883, Jena. Sitzungsber., Feb. 16, p. 18). This group comprises all those Monopylea or Nassellarlv which possess a complete lattice-shell, whilst the preceding P 1 e c t e 1- laria never develop a perfect fenestrated shell enveloping the central capsule. The Spyroidea differ from the other Cyrtellaria (Botryodea and Cyrtoidea) in the bilocular shape of the cephalis, which is bisected by the sagittal ring and a corresponding longitudinal constriction into two symmetrical halves. The Spyroidea appear in the first system of Polycystina of Ehrenberg (1847, loc. cit., pp. 53, 54) as the fourth of his seven families, under the name Spyridina, with the following definition : — " Testae nucleo destitutte (associatse et coalitse) ; cellulse binse clathratse, nucis forma amplse, strictura longitudinali levins discretse." Ehrenberg united them with his " Polycystina composita or Spumellaria " and separated them from the closely allied " Polycystina solitaria or Nassellaria." He distinguished among them five genera, two of which have no external appendages [Dictyospyris and Pleurof^pyris), whilst the other three possess spiny or lamellar appendages [Ceratospyris, Cladospyris, and Petalospyris). These five genera and the accompanying definitions were also repeated in the same terms in the last system of Ehrenberg (1875, loc. cit., p. 157). In my Monograph (1862, pp. 280, 291) the Spyroidea are enumerated as a sub- 1016 THE VOYAGE OF H.M.S. CHALLENGER. family of the Cyrtida, under the name Zygocyrtida, with the following definition : — " Lattice-shell divided by an annular sagittal longitudinal constriction into two neigh- bouring equal joints or chambers." I adopted at that time the above five genera of Ehrenberg, only eight species of which were known. Eichard Hertwig gave in 1879 the first accurate description of the central capsule of the S p y r o i d e a, and demonstrated that they possess the same characteristic structure of the capsule, with a porochora and a podoconus, that is common to all Monopylea. He separated the Zygocyrtida from the other Cyrtida, and united them with the Stephoidea (Lithocircus) in the family Acanthodesmida. In my Prodromus (1881, p. 440) I adopted that division and put the " Spyrida or Spyroidea" as a separate family between the Cyrtoidea and Stephoidea. I there gave the following definition : — Monopylaria gemina, testa silicea clathrata gemina, cameris binis juxta compositis, annulo verticali sagittali contiguis, capsula central! a testa inclusa. Promorpha dipleura vel bilaterali, dextro et sinistro antimero symmetricis, piano sagittali annuloque separatis. Polum superiorem axis verticalis vel principalis plerumque spina apicalis (vel occipitalis) occupat, polum inferiorem ostium clathratum (poris tribus aut quatuor aut pluribus) et spina caudalis (posterior). Ad dextram et sinistram duae spinse laterales distant. Ab hac forma tripoda (Monocjrrtida triradiata acuta cum annulo mediano) diversse Sp5rridum formae derivandse sunt." I there divided the Spyrida into seven subfamiHes and forty-eight genera. Btitschli in 1882 pubhshed accurate researches on the Zygocyrtida in his Beitrage zur Kenntniss der Radiolarien-Skelete, insbesondere der der Cyrtida (Zeitschr. f. wiss. ZooL, vol. xxxvi. ]). 501, Taf xxxii.). He gave a very exact anatomical description of the skeleton of several fossil Spyroidea of Barbados, and pointed out their close affinity to the Acanthodesmida on the one hand, and to the Cyrtida on the other. Regarding their phylogenetical relation, he supjaosed that the Zygocyrtida have descended from the Acanthodesmida (our Stephoidea) and are the ancestors of all other Cyrtida. The best part of this valuable paper of Btitschli is his exact description of the sagittal ring and its apophyses, producing the basal plate ; and the general conception thus derived of the essential parts of the skeleton in all MoNOPYLEA, bearing a sagittal ring. But his general conclusions were partly erroneous, since the fossil Spyroidea and Cyrtoidea of Barbados, upon which they were founded, contain only the minority of genera of the large groujj; and many important and typical forms remained unknown to him. The numerous new genera discovered in the rich collection of the Challenger, and mainly in the wonderful Radiolarian ooze of the Central Pacific (Stations 263 to 274) throw a new light upon the complicated affinities of the whole group, and manifest a far greater richness in developmental variations and admirable morphological productions than Btitschli could suppose. The following description, however, must remain very incom- jxlete, since the exact and thorough study of all indi"\adual forms, in the same manner as REPORT ON THE RADIOLARIA. 1017 Blitschli had done in the case of a small number of species, would require several years. I can therefore only give the basis of further researches. In the majority of Spyroidea the three essential elements of the Nassellarian skeleton are easily recognisable, viz. : — A, the vertical sagittal ring of the S t e p h o i d e a ; B, the basal tripod of the P 1 e c t o i d e a ; and C, the latticed cephalis of the C y r t e 1- 1 a r i a. These three elements are constantly so combined that the primary sagittal ring bisects the cavity of the lattice-shell and produces an external, longitudinal, more or less distinct constriction, separating the lateral inflated halves of the bUocular cephalis; while the three divergent feet of the basal tripod descend from the cortinar or basal plate of the cephalis. The number of the feet is often augmented ; they are rarely want- ing (probably reduced). The sagittal ring is constantly present, though its relation to the shell-wall exhibits many modifications. The bilocular form of the fenestrated cephalis, with its sagittal constriction, is characteristic of all true Spyroidea, and separates them from the Botryodea (with multilobate cephalis) on the one hand, and from the Cyrtoidea (with simple cephalis) on the other. There are, however, some intermediate forms between these three suborders of Cyrtellaria, which show a direct transition to one another. Almost constantly the length of the three dimensive axes in the cephalis of the Spyroidea is so diflerent that the lateral or frontal axis is the longest, the sagittal or dorso-ventral axis the shortest, and the principal or longitudinal axis intermediate between them. As in all dipleuric or bilaterally symmetrical forms, the two poles of the frontal axis are equal, whilst the two poles of the sagittal and of the principal axis are more or less different. In only a few forms of Spyroidea these differences are difiicult to make out ; usually the dorsal side is distinctly difi'erent from the ventral, and the apical side from the basal. A perfect knowledge of the dipleuric shell requires therefore accurate observation from all six sides. The suborder of Spyroidea is here divided into four difi'erent families. In the first and original family, the Zygospyrida, the shell is represented by the bdocular cephalis only. The second family, Tholospyrida, is distinguished by a fenestrated cupola or galea, a hemispherical or conical dome, arising from the upper or coryphal face of the cephalis. In the third family, Phormospyrida, a thorax is developed, or a fenestrated basal chamber, arising from the lower or basal face of the cephalis. The fourth family, Androspyrida, combines the characters of the second and the third family, a galea arising from the upper and a thorax from the lower face of the cephalis. The bilocular cephalis, as the most important and constant part of the skeleton in all Spyroidea, requires a further general consideration. Its lattice-work, very variable in the numerous species, is usually more or less different on the six sides of the nut-shaped shell. Its most important part is the horizontal basal plate or lower face, and the sao^ittal ring arising from it in the vertical median plane. This part of the shell corresponds exactly to the skeleton of the Semantida, and exhibits the same modifications (ZOOL. CHALL. EXP. PAHT XL. — 1886.) Rr 128 1018 THE VOYAGE OF H.M.S. CHALLENGER. as in that family ; it is therefore probable that the majority of the S p y r o i d e a (if not the whole group) have been derived directly from the Semantida by further development of network from the fenestrated ring of Clathrocircus. Whilst in this latter Semantid the two lateral sides of the central capsule remain naked, in the Spyroidea they become enclosed and covered by lattice-work, which arises on the right and left from the ring. In some forms, however, as in the Ceratospyris OAiuminata of Hertwig, and in my Perispyrida, the frontal ring also of the Coronida and the mitral ring of the Tympanida appear as the initial parts of a complete latticed cephalis. The basal plate of the cej)halis, or the " cortinar plate," the " Basal-Scheibe " of Biitschli, has constantly, according to this author, two pairs of pores, an anterior smaller pair of jugular pores (the pores I of Biitschli) and a posterior larger pair of cardinal pores (the pores II in his description) (compare PI. 95, figs. 3, 6). This applies to the majority of Sjjyroidea, but by no means to the whole group. We find basal plates with two pores only (PL 95, fig. 1), with three pores (figs. 2, 5), with, six pores (figs. 4, 7), with nine pores (PI. 87, fig- 2), &c. The forms with two basal pores may be derived directly from Semantis (PI. 92, figs. 1, 2); the common forms with four pores from Semantrum (figs. 3-5) ; the rarer forms with six pores from Semantidium (figs. 6, 7); and the forms with three pores from Cortiniscus, &c. In this as well as in other respects the variety of difi'erent forms and of developmental variations is far greater than Biitschli (1882, loc. cit.) supposed. The bars between the pores of the basal plate possess the same value and the same names as in the Semantida (compare above, p. 954). The coryphal plate of the cephalis, its ujDper or apical lattice-jDlate, does not exhibit such important difi'erences as the opposite basal plate, is far less variable, and is usually pierced by numerous, smaller pores. Some larger pores lie, often in pairs, on the right and left side of the sagittal constriction, and have in some groups a regular form and disposition. Either in the middle of the coryphal plate, or (usually) nearer to its dorsal margin, there arises in the majority of S p y r o i d e a an apical horn, directed either vertically or more or less obliquely backwards. In many Spyroidea three horns are developed in the coryphal plate, the odd middle apical horn and two paii-ed frontal or lateral horns arising on each side of the latter and directed more forwards (PL 84, figs. 9—12). Sometimes the apical horn disappears, while the two frontal horns remain (PL 95, fig. 12). The anterior or ventral plate of the cephalis (the " Hinterseite " of Biitschli), and the posterior or dorsal side (the " Vorderseite " of that author), exhibit in the majority of Spyroidea more or less marked difi'erences in the number, form, and disposition of their pores, which require a far more accurate description than is here possible. Usually the sagittal constriction of these two plates, produced by the primary vertical ring, is deeper and sharper in the middle of the ventral than in that of the dorsal plate. On both sides of the ring there appear in each plate usually two or three pairs of larger pores, whilst numerous smaller pores are situated towards the lateral sides. We may REPORT ON THE RADIOL ARIA. 1019 distinguish the large pores of the ventral plate as facial pores (upper orbital, middle nasal, and lower maxillary pores), and the opposite large pores of the dorsal plate as occipital pores (upper epoccipital, middle mesoccipital, and lower suboccipital pores). A closer comparison of these pores, and of the separating bars in the numerous S p y r o i d e a, may show a regularity of development similar to that offered by the homologies of the parts in the skeleton of the Echinodermata, or of the bones in the skull of the Vertebrata. The two convex lateral plates of the cephalis, or the right and left sides, both symmetrically equal, do not exhibit the same regularity in the shape, number, and disposition of the pores that the four other sides do. Usually theii* pores are much smaller and more numerous. In very few forms only a distinct frontal ring is visible (corresponding to that of the Coronida), and in this case the lateral pores are sometimes disposed symmetrically on both sides of this ring. These Spyroidea may have arisen directly from corresponding forms of Coronida. The sagittal ring (or the primary vertical ring, inherited from the Stephanida and Semantida, shows in the Spyroidea great variety in its form and in its relation to the cephalis. These variations are far greater than Biitschli (1882, loc. cit.) supposed. We may distinguish the following six principal cases : — A. The ring lies completely in the wall of the cephalis, and causes a deep sagittal constriction in it. In this case the lower part or basal segment of the ring separates the basal pores into pairs ; its anterior part or ventral rod the facial pores ; its upper part or coryphal rod the apical pores ; and its posterior part or dorsal rod the occipital pores. No part of the ring is free in the shell-cavity. B. The greater part of the ring lies enclosed in the shell- waU ; only its dorsal rod arises free in the shell-cavity and ascends vertically or obliquely to the apex, where it is usually prolonged into the apical horn. This seems to be the most common case. C. The coryphal and the basal part of the ring lie enclosed in the shell-wall, with its dorsal and ventral rod fi'ee in the shell-cavity ; the dorsal rod ascends vertically to the apex, the ventral rod obliquely upwards to the upper part of the facial plate (the nasal or orbital region). This case, regarded by Biitschli as the usual one, is far less common than he supposed. D. The greater part of the ring lies free in the shell-cavity, its basal rod only is enclosed in the shell-wall, and separates the right from the left group of the cortinar pores. This case seems to be rarer than the preceding. E. The whole ring lies free in the shell-cavity, and is connected with the sagittal constriction of the shell -wall by numerous short radial beams. The distance of the sheU-waH from the enclosed ring is usually least on the basal rod, and greatest on the dorsal rod. F. The whole ring lies free in the sheU-cavity (as in the preceding case), and is connected by numerous short radial beams with a secondary larger, concentric sagittal ring, which is developed in the longitudinal constriction of the shell-wall. 1020 THE VOYAGE OF H.M.S. CHALLENGEK. Comparing these sis principal cases, in respect of the relation of the primary sagittal ring to the cephalis of the Spyroidea, we may suppose that they represent together a continuous phylogenetical series, of which the first (A) is the original, and the last (F) the latest case ; and that the true cause of the various changes is a successive separation of the ring, which becomes more and more free and independent from the lattice-plate of the cephalis. Since the intimate study of the structure of the cephalis in many Spyroidea is very difficult, it requires further accurate observations (from all six sides of the shell). There are also some other more difficult complications of its structure, which cannot be solved without exact study and extended comparison. Of peculiar importance for the difi"erentiation of the numerous genera of the Spyroidea are the basal feet or the descending and diverging apophyses, which are developed from the base of their cephalis. In general they exhibit the same typical shape which we find in the Plectellaria as well as in the C y r t o i d e a, and which we regard therefore as an important common character of the majority of Nassellaria. We may therefore distinguish here also the three primary, and the other ones as secondary feet. The three primary feet, or the " cortinar feet," are the same that we found in the Plagonida and Plectanida, in Cortina and Cortiniscus among the Stephoidea, and in the majority of Cyrtoidea. They also reappear in the same characteristic disposition and connection with the basal plate of the cephalis, in the majority of S p y r o i d e a. The odd caudal foot (c) is the lower prolongation of the dorsal rod of the sagittal ring, which is prolonged upwards into the apical horn. The two paired pectoral feet, however (p'j p")> ^■i^^ the descending prolongations of the coracal rods (e) which separate the jugular pores (i) from the cardinal pores {k) of the cortinar plate (compare PI. 95, figs. 2-6). The three cortinar feet are nearly equally developed in the majority of Spyroidea (compare Pis. 84, 89). But often the odd caudal foot exhibits a difi'erent shape from that of the two paired pectoral feet, and in many genera of the group it becomes more or less rudimentary. It has quite disappeared in the subfamily Dipospyrida (PL 85) ; here the two pectoral feet only are developed (often excessively), and are usually opposite in the frontal plane. Such dipodal forms, very common in the Spyroidea, are never found in the Cyrtoidea. The secondary feet, which we contrast with the three primary feet as later productions, exhibit great variations in number and development. Very frequently three interradial secondary feet become developed, alternating with the three primary cortinar or perradiaJ feet, and opposed to them in pairs (PI. 95, figs. 7, 8). In these hexapodal Spyroidea (or Ilexaspyrida) an odd anterior or sternal foot (z) is opposite to the odd caudal foot, and two paired posterior or tergal feet {t,i One horn, . like a tree. I ' Feet with a ] series of lateral \ One horn, . spines. ) Feet simple, . Feet with a series of lateral spines, III. Subfamily Tetraspyrida. Two sagittal and two lateral feet. IV. SubfamHy \ Hexaspyrida. > Six basal feet. j V. Subfamily Pentaspyrida. Five basal feet. VI. Subfamily Therospyrida. Four paii'ed lateral ■ feet. (Two pectoral and two tergal.) VII. Subfamily Polyspyrida. Numerous (seven to - twelve or more) basal feet. VIII. Subfamily i Circospyrida. ^ No basal feet. ( Feet simple, not branched. Two sagittal, two pectoral, and two tergal feet. I Apex with one horn, ( Apex without a horn, Apex with one horn, Apex with three horns. Apex without a horn, f Apex with one horn, One caudal, two pectoral, and , ^ ^^j^ ^j^^^^ ^ two tergal leet. ^ Apex without a horn. Apex with one horn, .... Apex with three horns (one apical and two frontal). Apex with two lateral or frontal horns, Apex without a horn. Apex with one horn, Apex with three horns (one apical and two frontal). Apex with numerous horns, . Apex without a horn, Apex with one horn, .... Apex without a horn. 441. Tripospyris. 442. Triceraspyris. 443. Tristylospyris. 444. CepJialospyris. 445. Dipospyris. 446. Brachiospyris. 447. Dendrospyris. 448. Dorcadospyris. 44&. Gamospyris 450. Stephanospyris. 451. Tetraspyris. 452. Tessarospyria. 453. Hexaspyris, 454. Liriospyris. 455. Cardharospyris. 456. Clathrospyris. 457. ^gospyris. 458. Pentaspyris. 459. Zygospyris. 460. Elaphospyris. 461. Taurosp>yris. 462. Therospyris. 463. Petalospyris. 464. Anthospyris. 465. Oeratospyris. 466. Gorgospyris. 467. Circospyris. 468. Didyospyris. REPORT ON THE RADIOLARIA. 1025 Subfamily 1. Tripospyrida, Haeckel, 1881, Prodromus, p. 441. Definition. — Z y g o s p y r i d a tripoda, with three descending basal feet (the same as in Cortina, an odd posterior or caudal foot and two paired anterior or pectoral feet). Genus 441. Tripospyris,^ Haeckel, 1881, Prodromus, p. 441. Definition. — Z ygospyrida \\dth three basal feet and one apical horn. The genus Tri2wsp)yris (PL 84, figs. 1-7) is in the large group of Spyroidea probably the most original and typical form, from which, as a common ancestral form, all other genera of this polymorphous suborder may be derived. The shell is usually shaped like a nut or thorax, and exhibits two paired lateral chambers, which are separated by a distinct sagittal ring and a slighter or deeper sagittal constriction. The dorsal rod of the ring is prolonged at the upper pole into an ascending apical horn, at the lower pole into a descending caudal foot, whilst two paired pectoral or lateral feet arise from the anterior pole of the basal rod. These three divergent basal feet and the apical horn are the same four typical radial spines which we have encountered already in Plagoniscus (Plagonida), in Plectaniscus (Plectanida), in Cortina (Stephanida), and in Cortiniscus (Semantida). Compare above, p. 891. From all these Plectellaria, Tripospyris differs in the development of a complete bilocular lattice-shell, having the characters of the true Spyroidea. The numerous species of this genus may be placed in different subgenera, according to the different number of collar pores or cortinar pores in the basal plate (two, three, four, six, or more). These differences are very important, however" difficult to make out ; the following system therefore is a provisional one, and requires further accurate observations. Subgenus 1. Tripospyrantha, Haeckel. Definition. — Basal plate with two large pores only (the primary jugular pores of Semantis). 1. Tripospyris cortina, n. sp. (PI. 95, fig. 1). Shell ovate, smooth, about as long as broad, with slight ovate sagittal stricture, and broad primary ring in its wall. Basal plate with two large kidney-shaped coUar pores only (cardinal pores). Facial and occipital plates each with two pairs of large annular pores, and ten to twelve pairs of small lateral pores. Apical horn and the three basal feet of equal length, one and a half times as long as the shell, three-sided prismatic, straight, divergent. Dimensions. — Shell O^OS long, 0'09 broad ; horn and feet 0'15 long. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 1 rripos^i/n's= Basket ^vith a tripod ; tj/xoj, avviili. (ZOOL. CHALL. EXP. — PART XL. — 1886.) Er 129 1026 THE VOYAGE OF H.M.S. CHALLENGER. 2. Tripospyris cortiniscus, n. sp. (PL 84, fig. 6). Shell ovate, smooth, one and a third times as long as broad, with sharp ovate sagittal stricture and broad primary ring. Basal plate with two large cardinal pores only. Occipital plate with two pairs of very large pores ; facial plate and lateral sides with numerous smaller irregular rounchsh pores. Apical horn small, conical, curved, half as long as the three basal feet, which are club- shaped and three-edged, with thinner bases and half as long as the shell, strongly divergent. Dimensions. — Shell 012 long, 0-09 broad ; horn 0-03 long, feet 006 long. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 3. Tripospyris semantis, n. sp. (PL 84, figs. 2, 3). Shell subspherical, smooth, somewhat broader than long, with slight sagittal stricture and sub- circular parietal primary ring. Basal plate with two large semicircular cardinal pores. Facial and occipital plate each with two pairs of large annidar pores and an odd large subapical pore ; lateral sides with very numerous small roundish pores. Apical horn and caudal foot club-shaped, half as long as the shell, angular, simple ; the two pectoral feet somewhat longer, nearly vertical, and at the distal end with a small incision, nearly forked. Dimensions. — Shell 01 long, 012 broad ; horn and feet 0'05 to 0'07 long. Habitat. — North Pacific, Station 24-i, depth 2900 fathoms. 4. Tnpospyris diomma, n. sp. (PL 84, fig. 5). Shell thorax-shaped, smooth, twice as broad as long, with deep sagittal stricture, two vaulted ovate bosoms and smaller ovate internal primary ring. Basal plate with two large ovate cardinal pores. Facial plate with three pairs, occipital plate with four pairs of large annular pores ; the other lattice-work loose, with small and numerous irregular polygonal pores. Apical horn and caudal feet slender and thin, curved, shorter than half the shell ; two pectoral feet also small, widely divergent, more or less curved, deeply forked. Dimensions. — Shell 01 long, 016 broad ; horn and feet 0*2 to 0"25 long. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. Subgenus 2. Tripospyrella, HaeckeL Definition. — Basal plate with three large collar pores (two paired posterior cardinal pores, and an odd anterior sternal pore). 5. Tripospyris triomma, HaeckeL Ceratospyris triomma, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xxi. fig. 3. Shell subspherical, tuberculate, with slight sagittal stricture and circular internal ring. Basal plate with three large pores, which are sometimes (but not in every specimen) surrounded by a REPORT ON THE RADIOLARIA. 1027 circle of very small pores. The other lattice-work with numerous small roundish pores. Apical horn small, oblique, about as long as the shell. Three feet very large, cylindrical, curved, widely divergent, four to five times as long as the shell. (In Ehrenberg's description the caudal foot is erroneously described as " frontal spine " ; its figure exhibits the basal plate.) Bimensions. — Shell 0-07 to 0-09 diameter ; horn 0-06 long, feet 0-3 to 0-4 long. Habitat. — Fossil in Tertiary rocks of Barbados. 6. Tripospyris conifera, n. sp. (PL 84, figs. 7, 7a). Shell nearly hemispherical, papillate, with sKght sagittal stricture and semicircular internal ring. Basal plate with three large pores (sometimes, as in the figured specimen, with some small accessory peripheral pores). The other lattice-work with subregular circular pores. Apical horn shorter than the three basal feet, but of similar form, like an elegant ovate dimpled cone, spinidate, with a smooth spindle-shaped pedicle, about as long as the shell. Bimensions. — Shell 0-08 long, Ol broad ; horn 0-06 long, feet 0-08 long. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 7. Triiwspyris triplecta, n. sp. (PL 95, fig. 2). Shell thorax-shaped, spiny, with deep sagittal stricture and semicircular internal ring. Basal plate with three large collar pores. Facial plate with four pairs, occipital plate with three pairs of large annular pores ; the other pores small, subregidar, circular. Apical horn and the feet slender, three-sided pyramidal, about as long as the shell. Bimensions. — Shell 01 long, Oil broad ; horn and feet 01 to 015 broad. Habitat. — Mediterranean, Corfu (Haeckel), surface. Subgenus 3. Tripospyrissa, HaeckeL Definition. — Basal plate with two pairs of coUar pores (two larger posterior cardinal pores and two smaller anterior jugular pores). 8. Tripospyris semantrum, n. sp. (PL 95, fig. 3). Shell thorax-shaped, thorny, with deep sagittal stricture and subcircular ring. Basal plate with four large collar pores (two smaller ovate jugular, and two larger pentagonal cardinal pores). Facial and occipital plates also each with two pairs of large annular pores ; lateral sides with smaller irregidar polygonal pores. Apical horn and the three feet slender, prismatic, divergent, longer than the shell. Bimensions. — Shell 0"07 long, 0'08 broad ; horn and feet Oil to 013 long. Habitat. — South Atlantic, Cape of Good Ho^^e (Willielni Bleek), surface. 1028 THE VOYAGE OF H.M.S. CHALLENGEE. 9. Tripospyris capitata, n. sp. (PI. 84, fig. 1). Shell subspherical, spiny, with slight sagittal stricture and ovate internal ring. Basal plate with four large collar pores. Facial plate with three pairs and occipital plate with two pairs of large roundish annular pores ; lateral lattice with smaller irregular pores. Apical horn and the three feet subcylindrical, about half as long as the shell, straight, divergent, with a spherical, spiuulate knob at the distal end. Dimensions. — Shell 0-09 long, 01 broad ; horn and feet 0'05 to 0'06 long. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 10. Tripospyris clavata, Haeckel. Ceratospyris davata, Biitsclili, 1882, Zeitschr. f . wiss. Zool.,vol. xxxvi. p. 539,Taf. xxxii.flg. 13, a-c. Shell subspherical, compressed, rough, with slight sagittal stricture and ovate internal primary ring. Basal plate with four large collar pores (fig. 13,a, loc. cit). The other lattice-work with irregular small roundish pores. Apical horn and the three feet short and thick, scarcely half as long as the shell, with a roundish spinulate knob at the distal end. Dimensions. — Length of the shell 0'07 long, 0'08 broad ; horn and feet 0'02 to G'03 long. Habitat. — Fossil in Barbados. 11. Tripospyris tessaromma, n. sp. Shell nearly cubical, spiny, with deep sagittal stricture and subcircular ring. Basal plate with four large collar pores. Facial and occipital plates each also with two pairs of large square annular pores ; lateral pores irregular polygonal. Apical horn half as long as the feet, which are three times the length of the shell, cylindrical, slightly curved. Dimensions. — Shell O'l long, 012 broad ; horn 015 long, feet 0"3 long. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. Subgenus 4. Tripospyromma, Haeckel. Definition. — Basal plate with sis or more collar pores. Commonly two small anterior jugular pores, two large middle cardinal pores, and two small posterior cervical pores ; sometimes several small accessory collar pores. 12. Tripospyris hexomma, n. sp. (PI. 95, fig. 4). Shell thorax-shaped, tuherculate, with deep sagittal stricture and semicircular internal primary ring. Basal plate with three pairs of pores. Facial plate with two pairs, occipital plate with four pairs of large annular pores. Lateral pores smaller, irregular, polygonal. Apical horn and caudal foot half as long as the shell and as the two pectoral feet ; all four spines cylindrical, two to three times as long as the shell, slightly curved. Dimensions. — Shell 01 long, 012 broad ; horn and feet 0-2 to 04 long. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. REPORT ON THE RADIOLARIA. 1029 13. Tri'pospyris semantidium, u. sp. Shell nut-shaped, thorny, with sharp sagittal stricture and subcircular ring. Basal plate with three pairs of large pores. Facial and occipital plates each with three pairs of large squarish pores. Lateral pores small and numerous, irregular roundish. Apical horn half as long as the shell and the three feet ; all four spines straight, cylindrical, with thickened club-shaped end. Dimcnsiom. — SheU 012 long, 013 broad ; horn 0-06 long, feet 015. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. 14. Triposi^yris eucolpos, n. sp. (PI. 84, fig. 4). SheU thorax-shaped, smooth, with two vaulted bosoms, separated by a deep sagittal stricture and an internal primary ring. Basal plate constricted, with three pairs of coUar pores. The other lattice-work with subregular circular pores. Apical horn and the three feet shorter than the shell, straight, divergent ; their inner half thinner, cylindrical, smooth, their outer half an ovate dimpled cone. Dimetisio'ns. — SheU 01 long, 013 broad ; horn and feet 0'06 long. Sabitat. — Indian Ocean, Cocos Islands (Eabbe), surface. 15. Tripospyris tribrachiata, Haeckel. Cladospyris tribrachiata, Ehrenberg, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. xxi. fig. 8. Shell subspherical, smooth, with slight sagittal stricture and numerous, very small circular pores. Basal plate with numerous small pores. Apical horn and the three divergent feet very large and stout, straight, three-sided prismatic, with dentate edges, two to three times as long as the sheU. Divwnsions. — SheU diameter 0'05 ; horn and feet 01 to 015 long. Habitat. — FossU in Barbados. 16. Tripospyris furcata, n. sp. (PI. 83, fig. 11). SheU nut-shaped, smooth, with deep sagittal stricture and broad ring. Basal plate with three pairs of smaU pores. Facial and occipital faces each with a pair of very large holes. Apical horn and caudal foot simple conical, two pectoral feet forked or irregularly branched. Dimensions. — SheU 0'08 long, 012 broad ; horn and feet O^Oo long. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 442. Triceraspyris^ Haeckel, 1881, Prodromus, p. 441. Definition. — Zygospyrida with three basal feet and three corj^hal horns. The genus Triceraspyris has arisen from the preceding ancestral Tripospyris by the development of two paired frontal horns, so that the shell here bears six ajjpendages, ' 2Vic«ras/iyris= Basket with three horns ; T^/xsja;, a^irv^ii. 1030 THE VOYAGE OF H.M.S. CHALLENGER. three superior or coryphal spines and three inferior or basal spines ; two of these are odd and dorsal (the apical horn and the caudal foot), the four others are paired and ventral (the frontal horns and the pectoral feet). The numerous species of this genus may be divided into three subgenera, according to the simple or branched shape of the ascending horns and of the descending feet. Subgenus 1. Triospyris, Haeckel, 1881, Prodromus, p. 441. Definition. — Horns and feet simple, not branched nor forked. 1. Triceraspyris tripodiscus, n. sp. Shell nut-shaped, tuberculate, with deep sagittal stricture. Pores irregular roundish, two pairs of ■larger pores on each side of the ring. Basal plate with three large pores. Horns and feet slender cylindrical, straight, divergent ; three horns about as long as the shell, three feet twice as long. Dimensions. — Shell 0'06 long, 0'08 broad ; horn 0'05 long, feet 01. Habitat. — Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms. 2. Triceraspyris cortiniscus, n. sp. Shell subspherical, smooth, with slight sagittal stricture. Pores small and numerous, subregular roundish. Basal plate with two large pores (?). Apical horn conical, short, half as long as the shell and the two lateral horns, which are curved outwards. AU three feet equal, cylindrical, strongly curved and divergent, twice to three times as long as the shell. Dimensions. — Shell 0-07 long, 0'08 broad ; horn 0-04 to 0-08 long, feet 015 to 0-2 long. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 3. Triceraspyris didiceros, Haeckel. Ceratospyris didiceros, Ehienberg, 1875, Abhandl. d. Akad. d. Wise. Berlin, p. 66, Taf. xxi. fig. 6. Shell nut-shaped, thorny, with superficial sagittal stricture. Pores large, irregular roundish. Basal plate with four larger pores. Apical horn and caudal foot small, conical, shorter than half the shell. The two frontal horns longer, slender conical. The two pectoral feet very large, cylindrical, nearly parallel, vertical, slightl}' curved, twice to three times as long as the shell. Di'mensions. — Shell 0-07 long, 0'09 broad ; two sagittal spines 0"02 long, two lateral horns 0-04 long, two lateral feet 015 to 0-25 long. Habitat. — Fossil in Barbados. Subgenus 2. Triospyrium, Haeckel. Definition. — Horns simple, not branched ; feet forked or branched. REPORT 0¥ THE RADIOLARIA. 1031 4. Tnceraspyns furcata, Haeckel. Oeratospyris furcata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xx. fig. 8. Shell nut-shaped, tuberculate, with slight sagittal stricture. Pores numerous, irregular roundish. Basal plate with four large pores. Three horns small, conical, shorter than half the shell. Three feet large, cylindrical, curved, about twice as long as the shell, forked at the distal end. Dimensions. — Shell 0-07 long, 0'08 broad ; horns 0-02 long, feet 01 to 012 long. Sabitat. — Fossil in Barbados. 5. Triceraspyris giraffa, n. sp. (PI. 84, fig. 11). Shell nut-shaped, mammiUate, with slight sagittal stricture. Pores numerous, subregular circular. Basal plate with nine pores (three larger central and three alternate pairs of smaller peripheral, as in PI. 87, fig. 2). Three horns equal straight, divergent, shorter than the shell, in the basal half cylindrical, in the distal half spindle-shaped. Three feet cylindrical, twice as long as the shell, nearly parallel, vertical, at the distal end divergent, with a recurved branch near the base. Dimensions. — Shell 0-08 long, 01 broad ; horns 005 to 0-07 long, feet 016 long. Habitat. — "Western Tropical Pacific, Station 225, depth 4475 fathoms. 6. Triceraspyris gazella, n. sp. (PI. 84, fig. 9). Shell nut-shaped, tuberculate, with sharp sagittal stricture. Pores large, irregular roundish ; two or three pairs of larger pores on each side of the ring. Basal plate with three large triangular pores. Three horns simple, about as long as the shell, the apical straight, the two frontal elegantly curved. Three feet somewhat longer, slender, curved, with a recurved branch near the base, repeatedly forked at the distal end. Divunsions. — SheU 0-06 long, 0-09 broad ; horn 0-05 long, feet 0-08 long. Habitat. — Indian Ocean (Cocos Islands), surface (Rabbe). 7. Triceraspyris corallorrhiza, n. sp. (PL 84, fig. 12). SheU nut-shaped, spiny, with deep sagittal stricture. Pores irregular polygonal or roundish. Basal plate with two large semicircular pores. Three horns slender, simple, about half as long as the shell. Three feet of the same length, slender, divergent, ii-regularly branched like coral. Diinensions. — Shell O'OG long, 0-09 broad ; horn and feet O'OS to 0-05 long. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 8. Triceraspyris maniculata, n. sp. Shell subspherical, smooth, without external sagittal stricture. Pores subregular circular. Basal plate with four large pores (?). Three horns simple, straight, divergent, spindle-shaped, half 1032 THE VOYAGE OF H.M.S. CHALLENGER. as long as the shell. Caudal foot of the same form, twice as long. Two pectoral feet cylindrical, curved, twice as long as the shell, palmate, divided at the distal end into five short fingers. Dimensions. — Shell O'OS diameter ; horns 0-04 long ; lateral feet 012 long. Habitat. — North Pacific, Station 241, depth 2300 fathoms. 9. Triceraspyris longicornis, n. sp. Shell nut-shaped, papillate, with deep sagittal stricture. Pores irregular roundish. Basal plate with six pores (?). Apical horn short, conical, two frontal horns very large, curved, widely divergent, longer than the shell. Three feet of about the same length, irregularly branched. Dimensions. — Shell O'OS long, 0-12 broad ; lateral horns and feet 015 to 0-2 long. Sabitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. Subgenus 3. Triospyridium, Haeckel. Definition. — Horns and feet forked or branched. 10. Triceraspyris damaecornis, n. sp. Shell nut-shaped, smooth, compressed, with broad sagittal ring. Pores irregular roundish ; one pair of very large pores on each side of the ring. Basal plate with four large coUar pores. Three horns and three feet short, divergent, slightly curved, about half as long as the shell, irregularly branched. (In general form very similar to Maphospyris damaecornis, PI. 84, fig. 10, with which I formerly confounded it.) Dimensions. — Shell O'OS long, 012 broad ; horns and feet 0-04 long. Habitat. — South Pacific, Station 295, depth 1500 fathoms. 11. Triceraspyris arhorescens, n. sp. SheU subspherical, with deep sagittal stricture. Pores irregular roundish ; three pairs of larger pores on both sides of the ring. Basal plate with two large coUar pores. Three horns about half as long as the shell, with few irregular terminal branches. (Beginning of a cupola.) Three feet strong, cylindrical, twice as long as the shell, richly branched, arborescent. Dimensions.— '&\iq\\ 0-09 long, 01 broad ; horns 0'05 long, feet 0'2 long. Habitat. — Indian Ocean (Madagascar), Eabbe, surface. Genus 443. Tristylospyris^ Haeckel, 1881, Prodromus, p. 441. Definition. — Zygospyrida with three basal feet, without apical horn. The genus Tristylospyris exhibits in general the same structure as the typical genus Tripospyris, its ancestral form. It differs from the latter in the absence of the apical 1 Tristylospyris ='BSi!iket with three styles; r^iarv^o;, a^v^ii. , REPORT ON THE RADIOLARIA. 1033 horu, wliicli is completely reduced, and may therefore be regarded as the simplest prototype of all tripodal C y r t e 1 1 a r i a without a horn. Subgenus 1. Tristylospyrula, Haeckel. Definition. — Feet simple, not branched nor forked. 1. Tristylospyris 2Jahnipes, n. sp. (PL 84, fig. 14). Shell companulate, smooth, with slight sagittal stricture. Pores irregular roundish, three pairs of larger annular pores on each side of the broad ring. Basal plate with four large collar pores. Feet half as long as the shell, sKghtly divergent, straight, prismatic, with a broad, hand-like, radially striped plate at the distal end. Dimensions. — Shell 0*1 long, 0"09 broad ; feet 0"06 long. HcAitat. — Equatorial Atlantic, Station 347, depth 2250 fathoms. 2. Tristylospyris scaphipes, n. sp. (PI. 84, fig. 13). Shell nut-shaped, smooth, with sharp sagittal stricture. Pores very small and numerous, circular; two pairs of larger pores on both sides of the ring. Basal plate with four large pores (?). Feet about half as long as the shell, angular, shovel-shaped, straight, parallel, vertical. Dimensions. — Shell 0'06 long, 0'08 broad ; feet 0'04 long. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 3. Tristylospyris davipes, u. sp. (PI. 84, fig. 15). Shell nut-shaped, rough, with deep sagittal stricture. Pores small, subregular circular. Basal plate with three large poi'es. Feet about as long as the shell, slender, straight, divergent, with a spinidate knob at the thickened distal end. DimensioTis. — Shell O^OG long, 0"08 broad ; feet O'Oo long. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 4. Tristylospyris triceros, Haeckel. Ceratospyris triceros, Elirenberg, 1875, Abhandl. d. k. Akacb d. Wiss. Berlin, p. 66, Taf. xxi. fig. 5. Shell nut-shaped, tuberculate, without external sagittal stricture. Pores circular, not numerous. Basal plate with four large collar pores. Feet large, cylindrical, three to four times as long as the shell, strongly curved and divergent. DimeTisions. — Shell O^OS long, 0'07 broad ; feet 0-1.5 to 0-2 long. Habitat. — Fossil in Barbados. * (ZOOL. CHALL. EXP. — PART XU — 1836.) . Rr 130 1034 THE VOYAGE OF H.M.S. CHALLENGER. Subgenus 2. Tristylospynum, Haeckel. Definition. — Feet forked or branched. 5. Tristylospyris furcata, n. sp. Shell subspherical, rough, with slight sagitta stricture. Pores subregular circular. Basal plate with three large coUar pores. Feet cylindrical, three to four times as loug as the shell, strongly curved and divergent, at the distal end forked, with two short (sometimes ramified) branches. Dimensions.- — Cephalis 0'08 long, 0'09 broad ; feet 0'2 to 0'3 long. Habitat. — South Atlantic (off Patagonia), Station 318, surface. 6. Tristylospyris ramosa, n. sp. (PI. 52, fig. 23). Shell subspherical, tuberculate, with a prominent sagittal ring. Pores irregular roundish. Basal plate with three large pores. Feet large, straight, widely divergent, about twice as loug as the shell, 'prismatic, irregiilarly branched. (Compare the following species.) Dimensions. — Shell O'OB in diameter; feet 015 long. Habitai. — Central Pacific, Station 265, depth 2900 fathoms. 7. Tristylospyris tripodiscium, n. sp. (PI. 52, fig. 22). Shell subovate, tuberculate, very similar to the preceding species. It diffeis from this in the very different size of the in-egular pores and the greater breadth of the pedal branches. The basal plate in a complete specimen (observed afterwards from the base) exhibited four large collar pores of the usual form, whilst in the similar preceding species it had three pores. In the similar Tripodiscium spharocephalum (PI. 52, fig. 21) the basal mouth is quite simple and open. Dimensions. — Shell 0'09 long, O'l broad ; feet 0"12 long. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. Genus 444. Ccphalospyris,^ Haeckel, 1881, Prodromus, p. 441 (sensu etnciid.y Definition. — Z ygospyrida with three basal feet and two large apical openings or coryphal holes, one on each side of the ring-apex. No true horns. The genus Cephcdospyris comprises some few Tripospyrida of very peculiar shape, differing from all other Zygospyrida in the possession of two large apical holes or coryphal apertures, lying on each side of a latticed sagittal septum, which is formed by the upper part of the sagittal ring. The sagittal stricture is deep, with a complete ^ Cephalospyns = liea.d-]\kc hasket ; Ki^atKY,, aTtvJs. JIEPOIIT ON THE EADIOLARIA. 1035 primary ring. The vertical axis of the slender ovate shell is much greater thau the transverse. The network is very delicate, with very small and numerous triangular or polygonal pores. Tlie central capsule encloses peculiar concrements (PI. 96, fig. 28). 1. Ceplialospyris cancellata, n. sp. (PI. 83, fig. 10). yheU slender ovate, two and a lialf times as long as broad, with deep sagittal stricture and complete ring. Network very delicate, with very small and numerous, irregular polygonal pores. Tlie two large apical holes are separated by a latticed triangular sagittal septum, the apex of which represents a rudimentary horn. Basal plate with two large coUar holes. Three feet slightly curved, divergent, about half as long as the breadth of tlie slicll ; the caudal foot slender, much thinner than the two stout pyramidal pectoral feet. Dimensions. — Shell 0'32 long, 0'13 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 2. Cephalo.'^pyris ovata, n. sp. Shell slender, ovate, twice as long as liroad, with deep sagittal stricture and complete ring. Network very delicate, with very small and numerous triangular pores (on both poles intermingled with irregular polygonal pores). The two large apical holes are separated by a latticed triangular sagittal septum, the upper edge of which is concave and bears two rudimentary horns. Basal plate with four large collar holes. Three feet latticed, slightly curved, convergent, scarcely one-eighth as long as the breadth of the shell. The central capsule filled up by concrements. Dimensions. — Shell 0'32 long, 0'16 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 3. Ceplialospyris triangulata, n. sp. (PI. 96, fig. 28). Shell ovate, one and a half times as long as broad, with deep sagittal stricture and complete ring. Network very delicate and regular, with small triangular pores of equal size. The two larcre apical holes are separated by a latticed semilunar septum, the upper edge of which is concave, and bears two rudimentary horns. Basal plate with three large collar holes (?). Three feet latticed, conical, nearly parallel and vertical (the caudal curved), about half as long as the breadth of the shell. The ovate central capsule contains peculiar amyloidal concentric concrements. Dimensio7is. — Shell 0'2 long, 0'14 broad. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. Subfamily 2. Dipospyeida, Haeckel, 1881, Prodromus, p. 441. Definition. — Zygospyrida dipoda, with two descending lateral basal feet (probably corresponding to the pectoral feet of Cortina). 1036 THE VOYAGE OF H.M.S. CHALLENGER. Genus 445. Di2)OS2)yris,'^ Haeckel, 1881, Prodromus, p. 441. Definition. — Z y g o s p y r i d a with two simple free basal feet and one apical horn. The genus Dipospyris and the following five genera represent together the interesting subfamily of Dipos^jyrida, which always bear two opposite lateral feet only. Therefore in this bipedal group the biradial or bilateral type of the S p y r o i d e a is particularh' expressed. Such bipedal forms never occur in the Cyrtoidea. ■ The topographical relation of the two lateral feet to the rods of the collar-plate, and to the cortinar pores separated by these, leaves no doubt that they correspond to the pectoral feet of Cortina and Tripospyris, and therefore that the Dipospyrida have originated from the Tripospyrida by loss of the caudal foot. Diposp>yris is the simplest form of the Dipo- spyrida, with two simple free feet. 1. Dipospyris hipes, n. sp. ' Shell thorax-shaped, smooth, with deep sagittal stricture, two vaulted bosoms, and subregular circular pores. Basal plate with two large collar pores only. Horn and feet equal, conical, straight, about as long as the shell ; the feet widely divergent. Dimensions. — Shell 0'08 long, 012 broad ; horn and feet O^l to 015 long. Habitat. — Fossil in Barbados. 2. Dipospyris 7nystax, Haeckel. Ceratosjjyris mystax, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlm, p. 66, Taf. xx. tig. 6. Shell elliptical spinulate, with slight collar stricture and large subregular circular pores. Bas£!,l plate with three pores (?) Horn small conical, oblique, shorter than the shell. Feet slender conical, longer than the shell, slightly curved, divergent. At the base of the columella, between the two feet, a small rudiment of the last caudal foot is visible. Dimensions. — Shell 0"06 long, 0"1 broad ; horn 0'02, feet 012 long. Habitat. — ^Fossil in Barbados. 3. Dipospyris cuhus, n. .sp. (PL 83, fig. 18). Shell box-shaped, subcubical, papillate, without external sagittal stricture, with numerous subregular circular pores. Basal plate with three very large collar pores, surrounded by a circle of smaller pores. Apical horn short and thick, scarcely half as long as the shell. Feet of the same, form, longer than the shell, widely divergent. Dimensions. — Shell 0-08 long. Oil broad ; horn 0'03 long, feet 014 long. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. ' Dipospyris = 'Basket with two feet ; 3iVo:/5, airvni;. EEPOllT UN THE EA.DIOLARIA. 1037 4. Dipospijris cheUfer, u. sp. (PI. 85, fig. 3). Shell elliptical, compressed, nodose, with deep sagittal stricture and irregular roundish pores. Basal plate with three pores (?). Apical horn stout, conical, twice to four times as long as the shell (often much longer than in the figured specimen). Feet scarcely longer than the shell, cylindrical, slightly curved towards one another. Dhmnsions. — Shell 0'08 long, 012 broad ; horn 0-2 to 0-3 long, feet 01 to 015 long. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 5. Dipospyris irregularitt, ii. sp. Shell subspherical, without external sagittal stricture, with small circular pores. Basal plate with four pores. Apical horn small, conical, shorter than the shell. Feet three to four times as long as the shell, cylindrical, irregularly curved, very variable in size and form. Dimensions. — Shell 0-08 long, 01 broad ; horn 0-02 to O'Ol long, feet 0-2 to O'o long. Habitat. — Central Pacific, Stations 266 to 268, depth 2700 to 2900 fathoms. 6. Dipospyris sigmop)odium , u. sp. Shell violin-shaped, thorny, with deep sagittal stricture and irregular roundish pores. Basal plate with four collar pores. Horn straight, conical, about as long as the shell. Feet twice as long,, cylindrical, markedly divergent, S-shaped, curved. Dimensions. — Shell 0^08 long, 012 broad ; horn 0-06 long, feet 0-2 long. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms ; also fossil in Barbados. 7. Dipospyris forcipata, u. sp. (PI. 85, fig. 1). Shell nut-shaped, tuberculate, with subregular circidar pores. Basal plate with four larger and a circle of six to ten smaller pores. Horn cylindrical, straight, two to three times as long as the shell. Feet three to five times as long as the shell, cylindrical, semicircular, with convergent and crossed distal ends. (If these ends grow together, Gamospyris arises.) Dimensions. — Shell O'OS long. Oil broad ; horn 015 to 0'2 long, feet 0-2 to 01 long. Habitat. — Central Pacific, Stations 263 to 268, depth 2600 to 3000 fathoms. Genus 446. Brachio.spyris,^ Haeckel, 1881, Prodromus, p. 441. Definition. — Zygospyrida witli two simple free basal feet, without apical horn. The genus Brachiospyris difi'ers from the preceding Diposi^yris, its ancestral form, only in the absence of the reduced apical horn, and therefore bears to it a similar ' iJrac/iio.<2«/n'.'- = Basket with two arms; /i^ayju^, otv^i;. 1038 THE VOYAGE OF H.M.S. CHALLENGER. relation to that which the hornless Tristylospyris, among the Tripospyrida, bears to the horned Tripospyris. Brxicliiospyris may therefore also be derived from Tristylosjyyris by loss of the caudal foot. 1. Brachiospyris oceUata, Haeckel. Cefatospyris ocellata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Bei'lin, p. 66, Taf. xx. fig. 5. Shell iiut-shaped, thorny, with slight sagittal stricture aud irregular roundish pores. Basal plate with four large aud four alternate pairs of smaller pores. Two feet cylindrical, straight, divergent, two to three times as long as the shell. Dimensions. — Shell 0-08 long, Oil broad; feet 0'2 to 0'3 long. Habitat. — South Atlantic, Station 335, depth 1425 fathoms ; also fossil in Barbados. 2. Brachiospyris diaeantha, u. sp. (PI. 95, tig. 5). 1 Ceratospyris diaeantha, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 303. Shell nut-shaped, tuberculate, compressed in the sagittal axis, convex on the frontal face, concave on the sagittal face, with a slight sagittal stricture ; with large irregular roundish pores. Basal plate with three very large pores. Two feet cylindrical, curved, S-shaped, about twice as long as the shell. Dimensions. — Shell 0'06 long, 0-09 broad ; feet 01 to 015 long. Hahitat. — Western Tropical Pacific (Philippine Sea), Station 206, depth 21(J0 fathoms. Genus 447. Dendrospyris,^ Haeckel, 1881, Prodromus, p. 441. Definition. — Z ygospyrida with two free lateral feet, forked or branched like a tree. Apex with a horn. The genus Dendrospyris differs from its ancestral form Dipospyris in the ramification of the two large lateral feet, which descend from the base of the shell, and are usually very large and stout, sometimes simply forked. 1. Dendrospyris stylophora, Haeckel. Ceratospyris styloj/hora, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xx. fig. 10. Shell nut-shaped, thorny, with subregular circular pores. Basal plate with four pores. Apical horn and the two divergent feet straight, cylindrical, larger than the sliell, forked" at the distal end. 1 Dendrospyris - Basket with arborescent feet ; osj/Sjok, owi/j iV. REPORT ON THE RADIOLARIA. 1039 (The size and muiibcr of the huk-brauches is variable ; the horn is sometimes simple. In some specimens a rudimentary remnant of the lost caudal foot is visible.) Dimensions. — Shell O'OS long, 0-09 broad ; horn and feet O'l to 0-12 long. Habitat. — Fossil in Barbados. 2. Dendrospyris dirrhiza, Haeckel. Ceratospyris dirrliiza, Ehrenberg, 1875, AbhancU. d. k. Akad. d. Wiss. Berlin, p. 6G, Taf. xx. fig. 9. Shell nut-shaped, spiny, very similar to the preceding species. It differs from that mainly in the gi-owth of the cylindrical feet, which are not straight and divergent, but more or less curved and convergent ; their distal ends are sometimes simply forked, sometimes repeatedly dichotomous. The size and form of the apical horn are also very variable. Dimensions. — Shell 0-06 long, 0-08 broad ; horn and feet 0-07 to 0-09 long. Habitat. — Fossil in Barbados. 3. Dendrospyris hihrachiata, Haeckel. Cladospyris hihrachiata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. "Wiss. BerKc, p. 68, Taf. xxi. fig. 7. Shell nut-shaped, smooth, with sharp stricture and numerous very small circular pores. Apical horn and the two feet very large and stout, straight, prismatic, with irregular lateral branches on their edges, twice to four times as long as the shell. (The horn in the Ehrenberg's figure is broken off.) This species is closely allied to Tripospyris tribrachiata. Dimensions. — Shell 0'05 long, 0-06 broad ; horn and feet O'l to 0'2 long. Habitat. — Fossil in Barbados. 4. Dendrospyris furcata, n. t. (PI. 85, fig. 5). Shell subspherical, tuberculate, with small regular circular pores. Basal plate with four larger pores. Apical horn four to six times as long as the shell, straight, cylindrical, smooth. Feet of the same length, crescentic or nearly semicircular, with crossed distal ends. On the convex edge of each foot a series of twelve to fifteen smooth conical teeth, partly longer than the shell. (Very variable in size and curvature of the feet, and number of their teeth.) Dimensions. — Shell 0'09 long, Oil broad; horn and feet 0'4 to 0-6 long. HaUtat. — Central Pacific, Stations 270 to 274, depth 2350 to, 2925 fathoms. 3. Dorcadospyris lunidata, n. sp. Shell subspherical spinulate, nearly of the same shape as in the preceding species, but with a short conical horn (scarcely as long as the shell); the feet are much more slender, crescentic, and bear twenty to thirty smaller smooth conical teeth (shorter than the shell). The distal ends of the feet are crossed. Dimensions. — Shell O'OS long, O'OO broad ; horn 0-06 long, feet 0-03 to 006 long. Hahitat. — ^Central Pacific, Station 266, depth 2750 fathoms. 4. Dorcadospyris decussata, n. sp. (PI. 85, fig. 7). Shell subspherical, smooth, very similar to that of the two preceding species. Horn small conical, about as long as the shell. Feet more than semicircular, more strongly curved than in any other species, each with four to eight small conical teeth, shorter than the shell ; distal ends crossed. (In this species also, besides the normal symmetrical form, there often occurs an asymmetrical form of the two feet ; one of these frequent anomalies is shown in fig. 7.) Dimensions. — Shell 0-06 long, 0-08 broad ; horn 0-05, feet 0-2 to 0-5 long. Habitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms. 5. Dorcadospyris dinoceras, n. sp. (PL 85, fig. 4). Shell subspherical, tuberculate, with subregular circular pores. Basal plate with four larger central and eight to twelve smaller peripheral pores. Horn about as long as the shell, in the basal half prismatic, smooth, in the distal half ovate or strobihform, spiny. Feet very large and strongly curved, together nearly heart-shaped, four to six times as long as the shell. Each foot bears on its outer convex side a series of fifteen to twenty or more strong conical teeth, which are again spinulate, perpendicular to the foot, and longer than the sheU. Dimensions. — SheU O'OS long, O'OQ broad ; horn 0-07 long, feet 0'3 to O'S long. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. (ZOOL. CHALL. EXP. — PAHT XL. — 1886.) Kr 131 1042 THE VOYAGE OF H.M.S. CHALLENGED. Genus 449. Gamospyris,'^ Haeckel, 1881, Prodromus, p. 441. Definition. — Z ygospyrida with two simple lateral feet, forming a ring by union. The genus Gamospyris and the similar Stephanospyris differ from all other S p y r o i d e a in the possession of a large basal ring, placed in the frontal plane of the shell. This ring has been produced by concrescence of the distal ends of the two large curved lateral feet of Dipospyris. 1. Gamospyris circulus, n. sp. (PI. 83, fig. 19). Shell subspherical, tuberculate, with subregular circular pores. Basal plate with four larger collar pores. Apical horn pyramidal, about as long as the shell. The connected feet form together a circular or nearly circular smooth ring, the diameter of which is three to four times as great as that of the shell. Dimemions. — Shell 0-08 long, O^OO broad ; diameter of the arm-ring 0-25 to 0'33. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 2. Gamospyris annulus, n. sp. Shell nut-shaped, tuberculate, with subregular circular pores. Basal plate with four large central and a circle of eight to twelve small peripheral pores. Apical horn conical, twice as long as the shell. The connected arms form together an elliptical smooth ring, which is five times as long and three times as broad as the shell. Dimensions. — Shell 0'07 long, 0'09 broad ; ring 0'33 long, 0'26 broad. Habitat. — Central Pacific, Station 258, depth 2900 fathoms. Genus 450. Stephanos2oyris,^ Haeckel, 1881, Prodromus, p. 441. Definition. — Z ygospyrida with two lateral feet bearing a series of secondary spines and forming a ring by union. The genus Stephanospyris exhibits tlie same peculiar armature of the semipinnate lateral feet as its ancestral genus Dorcadospyris, but differs from it in the concrescence of the distal ends of the feet, to form a complete foot-ring. The former therefore bears to the latter the same relation that Gam,ospyris does to Diposp>yris. 1. Stephanospyris cordata, n. sp. (PI. 85, fig. 10). Shell subspherical, tuberculate, with small regular circular pores. Basal plate with four larger pores. Apical horn cylindrical, three times as long as the shell, with three to four verticils 1 Gamospi/?-is= Basket with two feet grown together ; ycifto;, gtv^Is. ' Stephanospyris = Basket with a garland ; oTiipeti'of, a-avf^ii. REPORT ON THE RADIOLARIA. 1043 of teeth. The connected feet form a heart-shaped ring, four times as long and three times as broad as the shell. Each foot bears on the outer convex edge four to six stout conical teeth, shorter than the shell. Distal ends crossed and prominent. Dimensions. — Shell diameter 01 ; length of the arm-ring 0'4, breadth OS. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 2. Stephano&pyris verticillata, n. sp. (PI. 85, fig. 11). Shell nut-shaped, tuberculate, with subregular circular pores. Basal plate with numerous small pores. Apical horn cylindrical, four to six times as long as the shell, with six to ten verticils of teeth. The connected feet form a circular ring, the diameter of which is four times as great as that of the shell. Each foot bears ten to twelve conical teeth, about as long as the shell. Distal ends not crossed and not prominent. Dimensions. — Diameter of the shell 01, of the arm-ring 0-4. Haiitat. — Central Pacific, Station 266, depth 2750 fathoms. 3. Stephanosinjris excellens, n. sp. (PI. 83, fig. 20). Shell subspherical, tuberculate, with regular circular pores. Basal plate with numerous small pores. Apical horn cylindrical, twice as long as the shell, with eight verticils of teeth. The connected feet form an ovate ring, which is three times as long and two and a half times as broad as the shell. Each foot bears eight conical spinulate teeth, about as long as the shell. The crossed and prominent distal ends bear two parallel vertical teeth. Dimensions. — Diameter of the shell 01, of the arm-ring 0-2 to O'S. Babital— Central Pacific, Station 268, depth 2900 fathoms. Subfamily 3. Tetraspyrida, Haeckel, 1881, Prodromus, p. 442. Definition. — Z ygospyrida tetrapoda, with four descending basal feet, two of which are opposite in the sagittal plane (an odd caudal and an odd sternal foot), whilst the two others are paired lateral or pectoral feet. Genus 451. Tetraspyris^ Haeckel, 1881, Prodromus, p. 442. Definition. — Zygospyrida with four basal feet crossed in pairs (two sagittal and two lateral). Apex with a horn. The o-eniis Tetraspyris and the following closely allied Tessarospyris represent together the small subfamily of Tetraspyrida, characterised by the possession of four descending basal feet, three of which correspond to the three original feet of the 1 reirtwpi/m = Basket Tvith four feet ; Ttrja, uttv^i;. 1044 THE VOYAGE OF H.M.S. CHALLENGER. ancestral genera Cortina and Tr{pospy7ns, whilst the fourth is an odd anterior or sternal foot, produced by anterior prolongation of the basilar segment of the sagittal ring. Here, therefore, two opposed feet lie in the sagittal plane (a caudal and a sternal foot), whilst tlie two others are the paired lateral or pectoral feet, as also in Stephanmm and Stephaniscus, p. 965. The Tetraspyrida ought not to be confounded with the Therospyrida (sixth subfamily), in which the four feet have another signification. Subgenus 1. Tetrarrhahda, Haeckel, 1881, p. 429. Definition. — Feet simple, not branched nor forked. 1. Tetraspyris stephanium, n. sp. (PL 95, fig. 6). Shell nut-shaped, tuberculate, with deep sagittal strictvire and small roundish pores ; three pairs of larger pores on each side of the ring. Basal plate with four large coUar pores. Apical horn stout conical, half as long as the shell. Two pectoral feet somewhat longer than the two sagittal feet, one and a half times as long as the shell. All four feet straight, three-sided prismatic, strongly divergent. Dimemions. — Shell 0-08 long, 012 broad ; horn 0-04 long, feet 0-08 to 0-12 long. Hahitat. — Central Pacific, Station 272, depth 2G00 fathoms. 2. Tetraspyris cubica, n. sp. Shell nearly cubical, smooth, with slight sagittal stricture and small polygonal pores; some larger pores on both sides of the ring. Basal plate with four large collar pores. Apical horn and the four feet of equal size and form, about as long as the shell, cylindrical m the basal, spindle shaped in the distal half. Dimensions. — Shell 0'09 diameter ; horn and feet O'l long. Hahitat. — Central Pacific, Station 265, depth 2900 fathoms ; also fossil in Barbados. Subgenus 2. Tetracorethra, Haeckel, 1881, Prodromus, p. 429. Definition. — Feet branched or forked. 3. Tetrasp)yris tetracorethra, n. sp. (PI. 53, figs. 19, 20). Tetracorethra miraljilis, Haeckel, 1881, Prodromus, p. 429, and Atlas, loc. eit. Shell campanulate, tuberculate, with deep sagittal stricture and irregular polygonal pores ; two pairs of larger pores at the flattened occipital face (fig. 20). Basal plate with four large collar pores. Apical horn very long, thirty to forty times as long as the shell, slender three-sided prismatic, straight, at the distal end irregularly branched, besom-shaped. Four basal feet half as REPORT ON THE RADTOLARIA. 1045 thick as the horn, eight to twelve times as long as the shell, bristle-shaped, irregularly curved and branched, divergent, at the distal end besom-shaped. Central capsule very large ; the enclosed small campanulate part sends out through the four collar pores four very long club-shaped basal lobes, half as long as the feet ; each lobe contains a large oil-globule (fig. 19). Dimciisio-iis. — Shell 0-036 diameter; horn 1 to 1-5 mm. long, feet 0-3 to 0*4 long. Habitat. — Central Pacific, Station 270, surface. 4. Tetraspyris calcarata, n. sp. Shell campanulate, smooth, very similar to that of the preceding species, but differing in the follow- ing characters : — the two inferior occipital pores are four times (in the preceding twice) as large as the two superior ; the apical horn bears at its distal end only three simple branches ; the sternal foot is smaller than the three others, arises higher, is more divergent and curved, and bears at its base a large horizontal conical spur. Dimensions. — Shell 0'035 diameter ; horn 1 to 1'2 long, feet 0'2 to 0'3 long. Habitat. — Central Pacific, Station 266, surface. 5. Tetraspyris scoparia, n. sp. Shell campanulate, rough, very similar to the two preceding species, but differing in the following characters : — the four occipital pores are of nearly equal size ; the apical horn is simple, not branched ; the four feet are forked near the base, so that apparently eight feet diverge, each in the distal half richly branched, besom-shaped. Dimensions. — Shell 0'038 diameter ; horn 1 to 11 long, feet 0'4 to 0'5 long. Habitat. — Central Pacific, Station 268, surface. Genus 452. Tessarospyris,^ Haeckel, 1881, Prodromus, p. 442. Definition. — Z ygospyrida with four basal feet crossed in pairs (two sagittal and two lateral). Apex without horn. The genus Tessarospyris differs from the preceding Tetraspyris, its ancestral genus, in the absence of the apical horn, and therefore bears to it the same relation that Tristylospyris does to Tripospyris. 1. Tessarospyris clathrohursa, n. sp. (PI. 53, fig. 8). Clathrohursa didyopus, Haeckel, 1881, Prodromus, p. 429, and Atlas, pL liii. fig. 8. Shell nearly ovate, strongly compressed, smooth, one and a half times as long as broad, with deep sagittal stricture in the basal half. Pores very small and niunerous, irregularly roundish. Basal plate with four very large triangular holes, two larger (posterior) cardinal, and two smaller (anterior) ■*■ 3'essaro«p2/ris = Basket with four feet ; tinca^a, aw^i'i. 1046 THE VOYAGE OF H.M.S. CHALLENGER. jugular pores ; above the latter (on the frontal face) two large mental pores. Two pectoral feet large, half as long as the shell, at the base fenestrated, vertical, and parallel. Two sagittal feet much smaller, nearly horizontal, pyramidal (the caudal larger than the sternal foot). Two longitudinal pectoral ribs arise on the frontal face. Dimensions. — Shell 0-21 long, 014 broad ; lateral feet 01, sagittal feet 0-02. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 2. Tessarospyris nucifofmis, n. sp. Shell nut-shaped, papillate, with deep sagittal stricture. Pores irregular roundish, on both sides of the ring three to six times as large as on the lateral sides. Basal plate with four large pores. Two pectoral feet cylindrical curved, twice as long as the shell and as the two sagittal feet ; the caudal is much stronger than the sternal foot. Dinwnsions. — Shell 0-06 long, 0-09 broad ; lateral feet 01, sagittal feet 0-05 long. Halitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. 3. Tessarospyris seminulum, Haeckel. Petalospyris seminulum, Stbhr, 1880, Palaeontogr., vol. xxvi. pL iii. fig. 12. Shell subspherical, smooth, with shght sagittal stricture and small circular pores ; some larger pores on both sides of the ring. Basal plate with two large (lateral) pores only. Four feet nearly equal, short, conical, divergent, scarcely one-fourth as long as the shell. Dimensions. — Shell 0'06 long, 0'08 broad; feet 0'016 long. Habitat. — Fossil in Tertiary rocks of Sicily (Grotte), Stohr. Subfamily 4. Hexaspyrida, Haeckel. Definition. — Zygospyrida hexapoda, with six descending basal feet; three of these are primary (one odd caudal and two paired pectoral feet), the other three are secondary, opposed diametrically to the former and alternating with them (one odd sternal and two paired tergal feet). Genus 453. Hexaspyris,^ n. gen. Definition. — Zygospyrida with six basal feet and one apical horn. The genus Hexaspyris and the two following closely allied genera represent together the peculiar subfamdy of Hexaspyrida, and differ from the other Zygospyrida in the possession of six descending basal feet; three of these are the three original, perradial, or primary basal feet of Cortina, Cortiniscus, Plagoniscus, Plectaniscus, Triposp>yris, &c. ; the other three, usually opposed to the former diameti'ically, are ' ifea;asp2/rw= Basket with sLx feet ; tia, oxpj/j. REPORT ON THE RADIOL A.RIA. 1047 secondary or interradial ; an odd sternal foot (opposed to the odd caudal) and two paired tergal feet (opposed to the two paired pectoral). Subgenus 1. Hexaspyridium, Haeckel. Definition. — Feet simple, not branched nor forked. 1. Hexaspyris alterna, n. sp. Shell nut-shaped, smooth, with deep sagittal stricture and irregular polygonal pores ; on each side of the stricture two pairs of larger square annular pores. Basal plate also with four larger collar pores. Apical horn twice as long as the shell, conical. Three primary feet (the apical and the two pectoral) slender, curved, as long as the horn ; three secondary feet (the sternal and the two tergal) are half as long as the former and more highly inserted ; all six feet strongly divergent, cylindrical, pointed. Dimensions. — SheU 0'06 long, 0-09 broad; horn 015 long, feet 0'08 to 014 long. Habitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms. 2. Hexaspyris setigera, Haeckel. Ceratoifpyris setigera, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xx. fig. 11. Ceratospyris setigera, Biitschli, 1882, Zeitschi'. f. wis.'!. Zool., vol. xxxvi. p. 539, Taf. xxxii- figs. 11a, 11 J. SheU nut-shaped, tuberculate, with a complete internal sagittal ring and numerous small circular pores. Basal plate with four larger central and a circle of twelve to twenty smaller peripheral pores. Apical horn half as long as the shell, bristle-shaped. Three prunary feet longer and more deeply inserted than the three secondary feet; all six feet strongly divergent, bristle-shaped, shorter than the shell. Dimensions. — Shell G'06 long, 0'09 broad ; horn 0'03 long ; primary feet 0'05, secondary 0-02 long. Habitat. — Fossil in Barbados. 3. Hexaspyris biitschlii, Haeckel. Ceratospyris trionnna, Biitschli (no7i Ehrenberg), 1882, Zeitschr. f. wiss. Zoo!., vol. xxxvi. p. 539, Taf. xxxii. fig. 12, a, b. Shell nut-shaped, spinulate, with a complete internal sagittal ring and subregular circular pores. Basal plate with twelve pores (four larger central and eight smaller peripheral). Apical horn stout, oblique, as long as the shell. Six feet of equal length, shghtly divergent, nearly vertical, slender three to four times as long as the shell. Dimensions. — SheU O'Oo long, 0'07 broad ; horn 0'06, feet 015 to 0^2 long. Habitat. — FossU in Barbados. 1048 THE VOYAGE OF H.M.S. CHALLENGER. 4. Hexaspyris spinosa, Haeckel. Petalospyris spiiiosa, Stokr, 1880, Pal;eontogr., vol. xxvi. p. 98, Taf. iii. fig. 14. Shell subspherical, smooth, with slight sagittal stricture and irregular polygonal pores ; on each side of the stricture two pairs of larger pores. Basal plate with two large pores only. Apical horn short, pyramidal, three primary feet half as long as the shell and twice as long as the three secondary feet. All six feet pyramidal, slightly divergent. Bime^isions.-^'&heW 0-05 long, 0-07 broad ; horn 0-02, feet 0-02 to 0-04 long. Habitat. — Fossil in Tertiary 'rocks of Sicily (Grotte, Caltanisetta). 5. Hexasi^yi'is ophirensis, Haeckel. Petalospyris ophirensis, Ehrenberg, 1872, Abliandl. A', k. Akad. d. Wiss. Berlin, p. 297, Taf. ix. fig. 24. Shell nut-shaped, with deep sagittal stricture and numerous irregular roundish pores ; two pairs of larger pores on each side of the stricture. Apical horn short, curved. Six feet equal, divergent, straight, slender, about as long as the shell. Dimensions. — Shell O^OS long, 01 broad; horn O'Ol, feet 0'05 to 0'08 long. Habitat. — Indian Ocean (Zanzibar), depth 2200 fathoms, PuUeu. Subgenus 2. Hexacorethra, Haeckel. Definition. — Feet forked or branched. 6. Hexaspyris hexacorethra, n. sp. (PL 95, fig. 8). Hexacorethra magica, Haeckel, 1882, Manuscript. Shell campanulate, smooth, with sharp sagittal stricture and irregular roundish pores. Basal plate with six larger collar pores. Apical horn very long and thin, three-sided prismatic, straight, ten to twenty times as long as the shell, branched at the distal end. Six feet thinner, bristle-shaped, six to eight times as long as the sheH, divergent, irregularly curved, in the distal part branched, besom-shaped ; the sternal foot at its base with a large conical horizontal spur. Dimensions. — Shell 0-034 diameter ; horn 04 to O'S long, feet 0'2 to 0'3 long. Habitat. — Central Pacific, Station 265, surface. 7. Hexaspyris articulata, Haeckel. Ceratospyris articulata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xx. fig. 4. Shell nut-shaped, tuberculate, with deep sagittal stricture and small irregular roundish pores. Basal plate with six pores (?). Apical horn conical, longer than the shell. Six feet very large, thick REPORT ON THE RADIOLARIA. 1049 cylindrical, divergent, three to four times as long as the shell, with few irregular lateral branches (often much more developed than in Ehrenberg's figure). Dimcmions. — Shell 003li long, 0-05 broad; horn 0-05, feet 01 to OlS long. Habitat. — Fossil in Barbados. Genus 454. Liriospyris,'^ Haeckel, 1881, Prodromus, p. 443. Definition. — Z y g o s p y r i d a with six basal feet and three coryphal horns. The genus Liriosjjyris differs from the preceding Hexaspyris, its ancestral form, in the possession of three corj^phal horns (one odd apical in the middle, and tvi^o paired frontal horns on each side of it); it therefore bears to the latter the same relation that Triceraspyris does to Tripospyris. 1. Lir.iospyris hexapoda, n. sp. (PL 86, fig. 7). Shell subspherical, smooth, with slight sagittal stricture and irregular roundish pores ; two to three pairs of large annular pores on each side of the stricture. Basal plate with four large collar pores. Three horns and six feet nearly of the same size and of similar form, conical, divergent, about one-third as long as the shell. Dimensions. — Shell diameter 0-09 to 01 ; horns and feet O'OS to 0'04 long. Ealitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms. 2. Liriospyris clathrata, Haeckel. Dictyospyris clathrus, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 25. Didyospyris clathrata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. "VViss. Berlin, p. 68, Taf. xix. fig. 7. Dictyospyris clathrata, Butscbli, 1882, Zeitschr. f. Wiss. Zool., vol. xxxvi. pp. 506, 539; Taf. xxxii. figs. 10«, 10?'. Petalospyris clathrus, Haeckel, 1862, Monogr. d. Radiol., p. 295. Shell campanidate or nearly spherical, smooth, with slight sagittal stricture. Three pairs of large annular pores on each side of the stricture ; a few smaller irregular pores on the lateral sides. Basal plate with six large collar pores (Btitschli, loc. cit, fig. lOa). Three horns and six feet nearly of the same size and form; short, conical, slightly divergent or nearly parallel, shorter than half the ring. (The size of the nine appendages is in this common species rather variable ; sometimes they are rudimentary, at other times much stronger than in the good figure of Biitschli.) Dimensions. — Shell diameter 0'08 to 0'09, horns and feet 001 to 003. Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific ; also fossil in Barbados and Sicily. ' £mos2))/m = Lily-basket ; Xe/^/oi/, jTt/j/f. (zOOL. CHALI,. EXP. PART XL. — 1886.) Hi 132 1050 THE VOYAGE OF H.M.S. CHALLENGER. 3. Lirios2')yris heteropoda, n. sp. Shell nut-sliaped, nodose, with deep sagittal stricture and small circular pores ; two pairs of larger pores on each side of the stricture. Basal plate with four larger central and eight smaller peripheral pores. Apical horn conical, as long as the shell and twice as long as the two curved frontal horns. Three primary feet twice as long as the shell and as the three secondary feet, which are more highly inserted. All six feet slender curved, divergent. Dimensions. — Shell 0"07 long, Oil broad; horn and secondary feet 0'08 long, primary feet 0"15 long. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 4. Liriospyris turrita, Haeckel. Ceratospyris turrita, Ehrenberg, 1875, ALhandl. d, k. Akad. d. Wiss. Berlin, p. 66, Taf. xx. fig. 1. Shell ovate, campanulate, smooth, with sharp sagittal stricture and irregular roundish pores ; three to four pairs of larger pores on each side of the stricture. Basal plate with four large collar pores. Three horns short and stout, conical, fenestrated at the base. Six feet slender, conical, nearly vertical, of equal size, only one-third as long as the shell. I)imcnsio7is.—'Si\e\\. O'OS long, 0'06 broad ; horns O'Ol long, feet 0'03 long. Habitat. — Fossil in Barbados. 5. Liriospyris amphithecta, n. sp. (PL 95, fig. 7). Shell nut-shaped, tuberculate, with distinct sagittal stricture and irregular roundish pores. Basal plate with six larger and twelve smaller pores. Three horns conical, the apical as long as the shell and twice as long as the curved frontal horns. Two pectoral feet cylindrical, very large, curved, divergent, about three times as long as the shell and as the four other feet, which are conical. Dimensions. — Shell 0'08 long, 012 broad ; apical horn 0'08, frontal horns 0'05 long ; length of the two pectoral feet 0'2, of the four others 0'06. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. •Genus 455. Cantharospiyris,^ n. gen. Definition. — Z ygospyrida with six basal feet, without apical horn. The genus Cantharospyris diflers from the preceding two hexapodal genera in the absence of horns on the coryphal face, and has therefore the same relation to them that the hornless Tristylospyris bears to the one-horned Tripospyris and the three- horned Triceraspyris^. ■ Ca»i/jix?-osp2/ns = Basket with six feet, like a beetle ; x»i/^«joj, axv^!;. REPORT ON THE RADIOLARIA. 1051 1. Cantharosjvjris carahus, n. sp. Shell nut-shaped, with deep sagittal stricture and irregular roundish pores. Basal plate with six larger pores. Six feet of different sizes, cylindrical, curved ; three primary feet (one caudal and two pectoral) about as long as the shell and twice as long as the three secondary feet. Dhnensions. — Shell 0-08 long, 012 broad ; feet 0-05 to 0-09 long. HaUtat. — Tropical Atlantic, Station 338, depth 1990 fathoms; Central Pacific, Station 268, depth 2900 fathoms. 2. Cantharospyris ateuchus, Haeckel. Ceratospyris ateuchus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xxi. fig. 4. Shell nut-shaped, tuberculate, with slight sagittal stricture and unequal circular pores. Basal plate with six larger pores. The two pectoral feet very large and stout, four to six times as long as the shell, widely divergent, curved. The four other feet much smaller and thinner, about as long as the shell. Dimensions. — SheU O'OG long, O'OS broad ; length of the two larger feet 0-2 to 0-3, of the four smaller 0-05 to 0-07. Habitat. — Fossil in Barbados. 3. Cantharospyris radicata, Haeckel. Ceratospyris radicata, Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 43; MikrogeoL, 1854, Taf. xxii. fig. 37. Haliomma radicatum, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 83. Fefalospyris radicata, Haeckel, 1862, Monogr. d. EadioL, p. 295. Petalospyris radicata, Stohr, 1880, Palseontogr., vol. xxvi. p. 79, Taf. iii. fig. 11. Shell nut-shaped, smooth, with slight sagittal stricture and irregular roundish pores ; two larger pores on each side of the ring. Basal plate with sLx pores (?). Six feet of equal size and similar form, conical, divergent, slightly curved, shorter than half the riag. Dimensions. — SheU 0-05 long, O'OS broad ; feet 0-02 long. Habitat. — Fossil in Barbados and SicUy. 4. Cantharospyris platyhursa, n. sp. (PI. 53, fig. 7). Platylursa compressa, Haeckel, 1881, Prodromus, p. 429; Atlas, pi. 53, fig. 7. Shell smooth, nearly discoidal circvilar, markedly compressed in the sagittal direction, with slight basal stricture. Pores very numerous, irregular polygonal, with thin bars. Basal plate with four very large pores. Six feet short, conical, nearly horizontally expanded. Two sagittal feet (caudal 1052 THE VOYAGE OF H.M.S. CHALLENGER. and sternal) larger, about half as long as the shell (shortened in the figure). The two sternal feet larger than the two small or rudimentary tergal feet. Dimensions. — Shell 015 long, 013 broad ; feet 0-02 to 0-06 long. HaUtat. — Central Pacific, Station 271, depth 2425 fathoms. Subfamily 5. Pentaspyrida, Haeckel, 1881, Prodiomus, p. 442. Definition. — Zygospyrida pentapoda, with five descending basal feet, one odd caudal foot, and two pairs of lateral feet (two anterior or pectoral, and two posterior or tergal feet). Genus 456. Clathrospyris,^ Haeckel, 1881, Prodromus, p. 442. Definition. — Z y g o s jj y r i d a with five basal feet and one apical horn. The genus Clathrospyris and the two following closely allied genera represent together the small subfamily of Pentaspyrida, differing from the other Zygospyrida in the possession of five descending feet on the basal face. Three of these are the primary cortinar feet (of Cortiniscus, Plagoniscus, Tri'posjiyris, &c.), whilst the two others are secondary tergal feet. The Pentaspyrida may therefore be probably derived from the Hexaspyrida by loss of the odd anterior or sternal foot. 1. Clathrospyris canielop>ardalis, n. sp. Shell nut-shaped, tuberculate, with deep sagittal stricture. Pores irregular roundish. Basal plate with six pores (?). Two pectoral feet very large, twice as long as the shell, cylindrical, curved. Two tergal feet half as long and thick as the pectoral. Caudal foot and apical horn straight, conical, half as long as the shell. Dimensions. — Shell 0'07 long, 0'09 Isroad ; horn and odd caudal foot 0'04 long ; pectoral feet 016, tergal O'OS long. HaUtat. — South Pacific, Station 297, depth 1775 fathoms. 2. Clathrosjiiyris jyyramidalis, n. sp. (PL 95, fig. 9). Shell four-sided pyramidal, truncate, thorny, with slight sagittal stricture. Pores very large, polygonal roundish. Two pairs of large pores on each side of the ring (at the frontal and the occipital plate). Lateral pores more numerous. Basal plate with four large pores. The four edges of the pyramid are prolonged into four short pyramidal divergent lateral feet (one-third as ' Clathrospyris = Latticed ba,sket ; xT^iiS^oi', a-rrv^i;. REPOET ON THE RADIOLARIA. 1053 long as the sliell). Caudal foot short. Horn at the apex of the truncate pyramid with two lateral teeth. Dimensions. — Sliell O'OG long, 0-08 broad ; horn and feet 0-02 long. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 3. Clathrospyris fusiformis, n. sp. Shell nearly cubical, smooth, with sUght sagittal stricture. Pores roundish; three pairs of larger pores on each side of the ring. Basal plate with six large pores. Five feet of equal length, slender, spindle-shaped, about as long as the shell, divergent. Apical horn conical, and half as long as the feet. Dimensions. — Shell O'OS long, 0-09 broad ; horn O'Oo long, feet 01 long. Habitat. — Fossil in Barbados. Genus 457. Aegospyris,'^ Haeckel, 1881, Prodromus, p. 442. Definition. — Z y g o s p y r i d a with five basal feet and three coryphal horns. The genus Aegos2'>yris differs from the preceding Clathrospyris, its ancestral form, in the possession of three horns on the coryphal face (one odd apical, and two paired frontal horns on each side), and therefore bears to the latter the same relation that Tricevaspyris does to Tripospyris, and Liriospyris to Hexaspyris. 1. Aegospyris aequispina, n. sp. SheU nut-shaped, tuberculate, with slight sagittal stricture. Pores subregular circular. Basal plate with four large collar pores. Three horns and five feet all of equal size and similar form, slender conical, slightly curved, widely divergent, about as long as the shell. Dimensions. — Shell 0-08 long. Oil broad ; horns and feet 0'08 long. Habitat. — Central Pacific, Stations 265 to 274, depth 2350 to 2925 fathoms. 2. Aegospyris octospina, n. sp. Shell nearly cubical, smooth, with slight sagittal stricture. Pores subregular circular; two pairs of larger pores on each side of the ring. Basal plate with four large pores. Two paired horns and four paired feet of equal size and similar form, S-shaped curved, twice as long as the shell. Odd horn and odd feet half as long, straight, conical. Dimensions. — SheU 0'08 long, 0'09 broad ; six paii-ed spines 0'2 long, two odd spines 01 long. Habitat. — South Atlantic, Station 323, depth 1900 fathoms. 1 Aegospyris = Goat-basket ; kiyoG-jrv^k. 1054 THE VOYAGE OF H.M.S. CHALLENGER. 3. Aegospyris longiharha, Haeckel. Ceratospyris longiharha, Ehrenberg, 1875, Abliandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xxi. figs. 1, 2. Shell nut-shaped, tuberculate, with slight sagittal stricture. Pores subregular circular. Basal plate with four larger central, and eight smaller peripheral pores. Apical horn and caudal foot .short, straight, conical ; two frontal horns longer, curved ; four paired feet slender, curved, twice as long as the shell. Dimensions.— SheW 0-06 long, 0"08 broad ; paired horns O^OS long, paired feet 0"1 long. Habitat. — Fossil in Barbados. 4. Aegospyris aegoceras, n. sp. (PI. 95, fig. 10). Shell nut-shaped, tuberculate, with deep sagittal stricture. Pores irregular roundish. Basal plate with three large pores. Apical horn and caudal foot short, straight, spindle-shaped ; two frontal horns as long as the shell, strongly curved ; four paired feet also curved, at the distal end ■ forked, divergent ; the tergal thinner and as long as the shell, the pectoral thicker and twice as long. Dimensions. — Shell 0'07 long, 0"09 broad ; pectoral feet O'l long. Rabitat. — North Pacific, Station 244, depth 2900 fathoms. 5. Aegospyris cap)rina, n. sp. (PI. 86, fig. 8). Shell nut-shaped, papillate, with sharp sagittal stricture. Pores irregular roundish, two pairs of larger pores on each side of the ring. Basal plate with six large pores. Eight spines all straight, subvertical and nearly parallel, cylindro-conical. Two frontal horns and two tergal feet about as long as the shell ; odd horn shorter ; odd foot longer. Two pectoral feet twice as long as the shell, club-shaped, with a spinulate knob at the distal end. Dimensions. — Shell 0"06 long, 0'09 broad; pectoral feet O'll long. Habitat. — Central Pacific, Station 271, surface. Genus 458. Pentaspyris,^ Haeckel, 1881, Prodromus, p. 442. Definition. — Z y g o s p y r i d a with five basal feet, without apical horn. The genus Pentaspyris differs from the two preceding genera in the absence of any coryphal horn, and represents therefore the pentapodal form among the hornless Zygospyrida. 1. Pentaspyris pentacantha, n. sp. (PL 95, fig. 11). Shell nut-shaped, tuberculate, with deep sagittal stricture. Pores irregular roundish, two pairs of larger pores on each side of the ring. Basal plate with four larger pores. All five feet cylin- ' Pentaspyris = Basket with five feet ; ■^ii/rx, a-Trv^l;. REPORT ON THE RADIOLARIA. 1055 drical, S-shaped curved, strongly divergent, with few short branches, the two pectoral feet twice as long as the shell and the two tergal feet ; odd caudal foot shorter. Dmciisio7is. — Shell O'OS long, 013 broad ; pectoral feet 0-2 long, tergal feet 01, caudal foot 0-06. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Pentasioyris isacantlia, n. sp. Shell subspherical, smooth, with slight sagittal stricture. Pores small, regular circular. Basal plate with six large pores (?). All five feet equal, cylindrical, C-shaped curved, slightly divergent, about a,s long as the shell. Dimensions. — Shell 0'08 long, 0'09 broad ; feet 0'07 long. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. Subfamily 6. Therospyrida, Haeckel, 1881, Prodromus, p. 442. Definition. — Zygospyrida tetrapoda with two pairs of descending basal feet, one pair corresponding to the anterior or pectoral, the other pair to the posterior or tergal feet of the Hexaspyrida. Genus 459. Zygospyris,^ Haeckel, 1881, Prodromus, p. 442. Definition. — Z ygospyrida with two pairs of lateral feet and an apical horn. The genus Zygospyris and the following three genera represent together the peculiar subfamily of Therospyrida. These always possess four basal feet, like the Tetraspyiida ; but whDst in the latter group two feet are sagittal, and two lateral, in the Therospjrrida there are no sagittal feet at all, but the four feet are opposed in two lateral pairs ; the anterior pair corresponds to the pectoral, the posterior to the tergal feet of the Hexaspyrida and Pentaspyrida ; from these latter the Therospyrida have been derived by loss of the sagittal feet. 1. Zygospyris quadrnpes, n. sp. Shell nut-shaped, tuberculate, with deep sagittal stricture. Pores irregular roundish, on each side of the ring two pairs of larger jjores. Apical horn conical, straight. Four feet equal, straight, divergent, conical, about as long as the shell and the horn. Dimensions. — Shell O'OS long, Oil broad; horn and feet 01 long. Habitat. — South Atlantic, Station 335, depth 1425 fathoms. 1 Zygospyris = Bilocular basket, -n-ith paired halves ; ^v/a, asv^i's. 1056 THE VOYAGE OF H.M.S. CHALLENGER. 2. Zygospyris equus, n. sp. (PI. 83, fig. 16). Shell subspherical, rough, with slight sagittal stricture. Pores small and numerous, subregular circular ; no larger annular pores. Apical horn cylindrical, half as long as the shell. Two pectoral feet somewhat smaller than the two tergal feet, about as long as the shell, slightly divergent, cylindrical. The distal ends of the feet and of the horn form an ovate, dimpled and spinulate cone. Dimensions. — Shell 0'06 long, 0-09 broad ; horn 0'04 long, feet 0'06 long. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. Genus 460. Elaphospyris,^ Haeckel, 1881, Prodromus, p. 442. Definition. — Z y g o s p 3^ r i d a with two pairs of lateral feet and three coryphal horns. The genus Elaphospyris differs from the preceding Zygospyris, its ancestral form, in the possession of three coryphal horns (one odd apical and two paired frontal horns), and therefore bears to it the same relation that Triceraspyris does to Tripospyris among the Tripospyrida. Subgenus 1. Giraffospyris, Haeckel, 1881, Prodromus, p. 442. Definition. — Feet simple, not branched nor forked. 1. JSlaphos^yyris heptaceros, Haeckel. Ceratospyris lieptaceros, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xx. fig. 2. Giraffoqjyris hej^faceros, Haeckel, 1881, Prodromus, p. 442. Shell nut-shaped, tuberculate, with slight sagittal stricture and subregular circular pores. Basal plate with four large pores. Apical horn small conical, shorter than the two curved lateral horns, which are as long as the shell. Caudal and sternal feet small, conical, straight. Two pectoral feet slender, divergent, S-shaped, about as long as the shell. Dimensioiis. — Shell 0'05 long, 0'07 broad; horns and feet 0'02 to O^OOS long. Habitat. — Fossil in Barbados. 2. Elaphosp>yris capricornis, n. sp. Shell nut-shaped, spiny, with slight sagittal stricture and numerous small circular pores. Basal plate with four large pores. Three horns slender, simple, about as long as the shell, the middle one straight, the two lateral curved. Four feet of nearly equal size, slender, curved, divergent, simple, twice as long as the shell and the horns. Dimensions. — Shell 0-07 long, 009 broad ; horns O'OS long, feet 015 long. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. ^ .Eia^jAos^J^m = Deer-basket ; iTicKpos, u'tiv^I;. REPORT ON THE RADIOLARIA. 1057 Subgenus 2. Corythospyris, Haeckel, 1881, Prodromus, p. 443. Definition. — Feet branched or forked. 3. Elaphospyris damaecornis, n. sp. (PL 84, fig. 10). Shell flat and broad, nearly triangular, with shght sagittal stricture and irregular roundish pores ; two very large pores on the frontal and on the occipital face, opposite on both edges of the broad sagittal ring. Basal plate with four large central and several smaller lateral pores. Three horns about half as long as the shell, with two to six irregular branches. Four feet of equal size, about as long as the shell, divergent, forked, with four to six irregular terminal branches. (The shell in fig. 10 is seen from the apical side.) Dimensions. — Shell 0'09 long, 0'13 broad ; horns 0'05 long, feet O'l long. Habitat. — Indian Ocean, Cocos Islands, Eabbe, surface. 4. Elaphospyris cervicornis, n. sp. (PL 86, fig. 13). Shell polyhedral, spiny, with deep sagittal stricture and a small number of large roundish pores ; two pairs of large pores on each side of the ring. ■ Basal plate with four pores. Three large horns as long as the shell arise from the apex between smaller conical spines ; the middle odd horn simple, the two lateral each with a pair of branches. Two pectoral feet very large, divergent, with broad and irregular distal ramification, twice as long as the shell and as the two tergal feet, which are less branched. (Fig. 13 exhibits the shell from the dorsal side.) Dimensions. — Shell 0-09 long, Oil broad ; horns and smaller feet O'OV to 009 long ; pectoral feet 016 long. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 5. Elaphospyris alcicornis, n. sp. (PL 86, fig. 12). Shell nut-shaped, spiny, with sharp sagittal stricture and large roundish pentagonaUy framed pores ; three pairs of larger pores on each side of the ring. Basal plate with four larger and four alternate smaller pores. There arise from the apex, between smaller spines, three large, divergent, pyramidal horns, which are nearly as long as the shell, and connected by an arched frontal bridge. Two pectoral feet very large, divergent, prismatic, longer than the shell, and at the distal end with a bunch of thick spines. Two tergal feet half as long and thick, simple (in the figure hidden beliind the large pectoral feet). DimcTisions. — Shell 0'09 long. Oil broad ; horns and smaller feet 006 long, pectoral feet 012 long. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. (ZOOL. CHALL. EXP. PART XL.^1886.) Rr 133 1058 THE VOYAGE OF H.M.S. CHALLENGEE. Genus 461. Taurospyris,'^ Haeckel, 1881, Prodromus, p. 442. Definition. — Z ygospyrida with twopairs of lateral feet and one pairof lateral horns. The genus Taurospyris bears only two frontal horns in the coryphal face of the shell, and may therefore be derived from the preceding closely aUied Elaphospyris by reduction and loss of the middle or apical horn. 1. Taurospyris cervina, n. sp. (PL 95, fig. 12). Shell nut-shaped, thorny, with deep sagittal stricture and irregular roundish pores ; three pairs of larger pores on each side of the ring. Basal plate with four large pores. Two horns cylindrical, curved, widely divergent, about as long as the shell, branched. Four feet of nearly equal length, also cylindrical and curved, divergent, somewhat longer than the shell, in the distal half branched like a deer's antler. Dimensicms. — Shell 0'07 long, O'll broad ; horns 0'03 long, feet 0'06 long. Habitat. — South Atlantic, Station 332, depth 2200 fathoms ; also fossil in Barbados. 2. Taurospyris hovina, n. sp. Shell subspberical, smooth, with slight sagittal stricture and small circular pores. Basal plate with six larger pores. Two horns conical, curved, divergent, about as long as the shell. Two pectoral feet very large, twice as long as the shell and as the two thinner tergal feet ; all four feet curved, cylindrical, divergent, pointed at the distal end. Dimensions. — SheU 0'08 long, 0'09 broad ; horns and posterior feet O'l, anterior feet 0"2 long. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. Genus 462. TJierospyris,^ Haeckel, 1881, Prodromus, p. 442. Definition. — Zygospyrida with two pairs of lateral feet, without apical horn. The genus Therospyris has two pairs of lateral feet corresponding to those of the pre- ceding three genera, but differs from them in the complete absence of horns on the coryphal face of the shell. 1. Therospyris canis, n. sp. Shell nut-shaped, tubercidate, with deep sagittal stricture. Pores irregular, roundish. Basal plate with four longer pores. Surface covered with roundish tubercles. Four feet equal, divergent, about as long as the shell, thickened at the distal end, club-shaped, not forked. Dimensions. — SheU 0-07 long, Oil broad ; feet O'OO long. Habitat. — Fossil in Barbados. ' Taurospyris = 'BxL\\-\)a.skitt ; T»i(>os, (1^1/5/5. 2 r/i«rosp2/ns= Basket with four feet, like u beast ; 6^^, a^yj/;. REPORT ON THE RADIOLARIA. 1059 2. Therospyris felis, u. sp. (PI. 89, fig. 6). Shell nut -shaped, mammillate, with sharp sagittal stricture. Pores large, irregularly roundish or polygonal, of somewhat different size. Basal plate with four large pores. Surface covered with hemispherical pomted mammilhie. Four feet equal, divergent, half as long as the shell, at the chstal end forked, with few small branches. Dimensions. — Shell 01 long, 0'15 broad; feet 0'05 long. Hahitat. — Central Paciiic, Station 268, depth 2900 fathoms. 3. Therospyris leo, n. sp. (PI. 89, fig. 5). Shell nearly cubical, papillate, with slight sagittal stricture. Pores irregular, roundish ; on each side of the ring three pairs of larger pores (the imdermost the largest). Basal plate with two large pores. Surface covered with conical papHlfe. Four feet equal, divergent, about as long as the shell, with an external spur in the middle, and irregularly branched spines at the distal end. Dimerisions. — Shell 0'08 long, 0'12 broad ; feet 0'09 long. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. Subfamily 7. Polyspyeida, Haeckel, 1881, Prodromu.s, p. 442. Definition. — Zy go spy rid a poljrpoda, with numerous descending basal feet {at least seven to nine, usually twelve to sixteen or more). Genus 463. Petalospyris,^ Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Definition. — Z ygospyrida with numerous (seven to twelve or more) basal feet and one apical horn. The genus Petalospyris and the following three genera form together the peculiar subfamily of Polyspyrida, differing from the other Zygospyrida in the multiplication of the radial feet, which descend from the basal face of the shell ; they may therefore be also called " Zygospyrida multiradiata," and bear the closest relationship to the Archi- phsenida (or the " Monocyrtida multiradiata "). They differ, however, from the latter in the presence of the distinct sagittal stricture, characteristic of all S p y r o i d e a. The number of the basal feet, which form a coronet around the margia of the basal plate, is commonly between twelve and sixteen, but often more. Their form is usually flat, lamellar, but often also more or less cylindrical or conical. 1 Petalospyris = Leaf-basket ; xsraTioj, k. 1060 THE VOYAGE OF H.M.S. CHALLENGER. Subgenus 1. Petalospyrantha, Haeckel. Definition. — Basal plate with two large collar pores only, separated by the base of the primary ring. 1. Petalospyris foveolata, Ehrenberg. Petalospyris foveolata, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 14; Abhandl d. k. Akad. d. Wiss. Berlin, 1875, p. 80, Taf. xxii. fig. 10. Shell campanulate, smooth, with distinct sagittal stricture and subregular circular pores. Basal plate with two large collar pores only. Apical horn and the eight feet slender, conical, sUghtly curved, about as long as the shell ; feet somewhat divergent (often seven or nine instead of eight). DimeTisioTis. — Shell diameter 0'04 to 0'05 ; length of the horn and the feet 0'04 to 0'05. Habitat. — Fossil in Barbados. 2. Petalospyris fioscula, n. sp. Shell nut-shaped, tuberculate, with deep sagittal stricture and subregular circular pores. Basal plate with two large triangular pores only. Apical horn slender, conical, twice as long as the shell. Twelve to sixteen feet flattened, leaf-shaped, broad, slightly divergent, as long as the shell, with truncate distal end. Dimensions. — Shell 0-06 long, 0-09 broad; horn 012 long, feet 0-05 to 0-07 long. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. Subgenus 2. Petalospyrella, Haeckel. Definition. — Basal plate with three large collar pores (two paired posterior cardinal, and an odd anterior sternal pore). 3. Petalosjyyris triomma, n. sp. (PI. 87, fig. 14). Shell nut-shaped, tuberculate, with sharp sagittal stricture and irregular roundish pores. Basal plate with three large pores and three alternate smaller. Apical horn stout, conical, half as long as the shell. Twelve to fifteen feet, divergent, curved, pointed, as long as the horn. Dimensions. — Shell 006 long, O'OS broad ; horn and feet 0-03 long. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 4. Petalospyris platyacantha, Ehrenberg. Petalospyris platyacantha, Ehrenberg, Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 80, Taf. xxii. fig. 8. Shell campanulate, smooth, with slight sagittal stricture and small irregular roundish pores. Basal plate with three large pores (?). Apical horn very strong, three-sided pyramidal, twice as REPOET ON THE RADIOLARIA. 1061 long as the shell (its edge is described by Ehrenberg as a " canaliculus.") Feet ten to twelve, flat, triangular, vertical, about as long as the shell. Dimensions. — Shell 0'04 long, 0'05 broad ; horn 007 long, feet 0'03 long. Habitat. — Fossil in Barbados. 5. Petalospyris corona, Stohr. Petdlospijris corona, Stbhr, 1880, Palaeontogr., voL xxvi. p. 98, Taf. iii. fig. 13. Shell nut-shaped, smooth, with sUght sagittal stricture and very numerous small circular pores ; on each side of the stricture three larger annular pores (the imdermost the largest). Basal plate with three large pores only. Apical horn very small, conical. Feet twelve to eighteen, short conical, nearly vertical, shorter than the half shell (in my specimen from Caltanisetta much stouter than in that of Stohr). Dimensions. — Shell 0-07 long, 0'09 broad ; horn and feet O'Ol to 0-03 long. Habitat. — FossU in Tertiary rocks of Sicily (Grotte, Caltanisetta). Subgenus 3. Petalospyrissa, Haeckel. Definition. — Basal plate with four collar pores (two lai-ger posterior cardinal and two smaller anterior jugular pores). 6. Petalospyris octopus, n. sp. (PL 87, fig 11). Shell nut-shaped, tuberculate, with sharp sagittal stricture and irregular, roundish pores. Basal plate with four larger pores. Horn slender, conical, half as long as the shell. Feet eight, very slender, about three times as long as the shell, subvertical, with outer convex edge and convergent ends. Dimensions. — Shell 0'06 long, 0-09 broad ; horn 0'03 long, feet 0'2 long. Habitat. — Tropical Atlantic, Station 342, depth 1445 fathoms. 7. Petalosp>yris eupetala, Ehrenberg. Petalospyris eupetala, Ehrenberg, 1875, Abhandl d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xxii. fig. 4. Shell nut-shaped, tuberculate, with slight sagittal stricture and scattered small circular pores. Basal plate with four large collar pores (sometimes surrounded by several small peripheral pores). Apical horn slender, conical, as long as the shell. Feet sixteen to twenty, laminated and truncate, of the same length, nearly vertical and parallel. Dimensions. — Shell 0-06 long, O'OS broad; horn and feet 0-05 to 0-07 long. Habitat. — FossU in Barbados. 1062 THE VOYAGE OF H.M.S. CHALLENGER. 8. Fetalospyris anthemis, n. sp. Shell nut-shaped, spinulate, with deep sagittal stricture and irregular, roundish pores. Basal plate with four large pores of equal size. Apical horn conical, twice as long as the shell. Feet twenty to thirty, laminated and truncate, as long as the shell, divergent. Dimensions. — Shell 0'05 long, 0"08 broad; horn 01 long, feet 0'6 long. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 9. Fetalospyris tessaromma, n. sp. Shell subspherical, with slight sagittal stricture and few small pores ; on each side of the stricture four larger, square, annular pores. Basal plate with four large collar pores (two larger cardinal and two smaller jugular pores). Horn and feet conical, about half as long as the shell. Feet twenty to twenty-five, slightly curved, convergent. Dimensions. — Shell diameter 0'08 ; horn and feet 0'04. Habitat. — Central Pacific, Station 268, depth 2900 fathoms; also fossU in Barbados. Subgenus 4. Petalosp>yromma, Haeckel. Definition. — Basal plate with numerous (six or more) collar pores, commonly three or four larger central, and six to twelve smaller peripheral pores. 10. Fetalospyris novena, n. sp. (PI 83, fig. 12). Shell nut-shaped, tuberculate, with slight sagittal stricture and irregular, roundish pores. Basal plate with nine pores (three large primary and three alternate pairs of small secondary pores). Nine long corresponding feet, twice to four times as long as the shell (three very thick primary, and three alternate pairs of thin secondary feet). All feet cylindrical, curved, widely divergent. Horn conical. Dimensions.— SheW 0-06 long, 0'08 broad ; horn and feet O'lo to 0'25. Habitat. — Indian Ocean (Cocos Islands), Eabbe,. surface. 11. Fetalospyris argiscus, Ehrenberg. Fetalospyris argisciis, Ehrenberg, 1875, Abhandl. d. k. Akad. Wiss. Berlin, p. 80, Taf. x.\ii. figs. 1, 2. Pefalospyris argiscus, Biitschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvL p. 539, Taf. xxxii. fig. 17, a, h. Shell nut-shaped, tuberculate, with slight sagittal stricture and irregular, roundish pores. Basal plate with nine pores (three larger central and three alternate pairs of smaller peripheral pores). REPORT ON THE RADIOLARIA. 1063 Apical horn slender, spindle-shaped, about as long as the shell. Twenty to twenty-five feet, of the same length, broad, lamellar and truncate, nearly vertical, slightly divergent. Bimmisions. — Shell 0-OG long, O'l broad ; horn and feet 0'05 to 0-07 long. Hahitat. — Fossil iu Barbados. 12. Petalosj>yris papillata, n. sp. SheU nearly cubical, papillate, without external sagittal stricture, with small, irregular, roundish pores. Basal plate with six pores (three larger and three alternate smaller). Apical horn conical, half as long as the shell. Feet twenty to thirty, one-half to one-third as long, conical, divergent. Dimensions. — SheU diameter 0-09 ; horn O'Oi long, feet 0-03 to 0'05 long. Hahitat. — North Atlantic, Station 353, depth 2965 fathoms. 13. Petalospyris dictyocuhus, n. sp. (PI. 86, fig. 6). Shell nearly cubical, smooth, without external stricture, but with a complete, parietal, square, sagittal ring. On each side of the rmg four pairs of larger pores, whilst the lateral pores are smaller and more numerous. Basal plate also with four pairs of larger pores and smaller lateral pores. Apical horn and -basal feet short, pyramidal, scarcely one- fourth as long as the shell. The three primary feet are larger than the sLx to nine secondary feet. Dimensions. — Shell diameter O'OS ; horn and feet 0'02 long. Habitat. — Central Pacific, Station 274, surface. 14. Petalospyris hellidiastrum, n. sp. SheU nut-shaped, tuberculate, with sUght sagittal stricture and irregular, roundish pores. Basal plate with twelve pores (four central larger and eight peripheral smaller pores). Apical horn slender, conical, about as long as the sheU (sometimes ramified at the distal end). Feet sixteen to twenty, broadly lamellar, truncate, divergent, about as long as the sheU. Dimensioiis. — SheU 0'08 long, O'l broad; horn and feet 0-07 to 0'09 long. Habitat. — Central Pacific, Station 265, depth 2900 fathoms ; also fossU in Barbados. 15. Petalospyris dinoceras, n. sp. (PL 87, fig. 12). SheU nut-shaped, mammUlate, without external stricture, but with complete external sagittal ring. Pores subregular, circular. Basal plate with four large central pores, surrounded by a circle of twelve to twenty smaU peripheral pores. Apical horn very large, spincUe-shaped, one and a half times as long as the sheU. Feet twenty-five to thirty, broadly lamellar, truncate, divergent, about as long as the sheU. Dimensions. — SheU O'll long, 0'13 broad ; horn 0-15 long, feet 0'09 long. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 1064 THE VOYAGE OF H.M.S. CHALLENGER. 16. Petalospyris furcata, n. sp. Shell nut-shaped, smooth, with sharp sagittal stricture. Pores numerous, small, and circular ; no larger annular pores. Basal plate with four larger and four alternate pairs of smaller pores. Horn conical, about as long as the shell. Feet fifteen to twenty, broadly lamellar, about twice as long as the shell, in the distal half forked. Dimensions. — Shell 0"04 long, 0-06 broad ; horn 0'05 long, feet 01 long. Edbitat. — South Pacific, Station 300, depth 1375 fathoms. 17. Petalospyris lohata, n. sp. (PI. 87, fig. 13). Shell subspherical, smooth, with slight sagittal stricture. Pores small, roundish ; on each side of the ring two pairs of larger annular pores. Basal plate with four pores. Horn stout, three- sided prismatic, half as long as the shell. Feet twelve to sixteen, lamellar, lobate (the most part with three lobes), nearly vertical, about as long as the shell. Dimensions. — Shell diameter 0'05 ; horn 0'03, feet 0'05 long. Habitat. — South Atlantic, Station 335, depth 1425 fathoms. Genus 464. Anihospyris,^ Haeckel, 1881, Prodromus, p. 443. Definition. — Zygospyrida with numerous (seven to nine or more) basal feet and three corj^hal horns. The genus Anthospyris difi"ers from the preceding Petalospyris, its ancestral form, in the possession of three horns on the coryphal face (one odd middle apical horn and two paired frontal horns, one on each side). The former therefore bears to the latter the same relation that Triceraspyy'is does to Tripospyris and Liriospyris to Hexaspyris. 1. Anthospyris mammillata, n. .sp. (PL 87, fig. 16). Shell nut-shaped, mammillate, with deep sagittal stricture and irregular, polygonal pores. Basal plate with two large ovate pores (?). The pediculate apical horn and the two frontal horns stout and short, conical, twice to three times as large as the conical papillse of the surface. Feet twelve to fifteen, lanceolate lamellar, pointed, divergent, about as long as the shell. Dimensions. — Shell 0'05 long, 0'08 broad ; horns 0'03, feet 0"04 long. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. ' .4ivfAosp2/ris = Flower-basket ; a!»tfof, aitv^k. REPORT ON THE RADIOLARIA. 1065 2. Anthosiiyris spathulata, n. sp. (PL 87, fig- 15). Shell subspherical, thoruy, with slight sagittal stricture and irregular, roundish pores. Basal plate with three large pores. The three horns spindle-shaped, half as long as the ten to twelve thin feet, which are pediculate, shovel-shaped, a little divergent, and shorter than the shell. Dimensions. — Shell 0-05 diameter ; horn 002 long, feet 004 long. Habitat. — Xorth Pacific, Station 250, depth 3050 fathoms. 3. Anthospyris diaboliscus, Haeckel. Petalospyris diaboliscus, Elireiiberg, 1854, MLkrogeol., Taf. xxxvi. fig. 12 ; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 80, Taf. ssii. fig. 3. Shell nut-shaped, smooth, with slight sagittal stricture and small circular pores. Basal plate with four large pores. . Apical horn straight conical, frontal horns curved laterally. Feet nine to twelve, of about the same length as the horns and the shell, broad lamelliform, truncate, nearly vertical, slightly curved. Diimnsions. — Shell 0-04 long, 0-07 broad ; horns and feet 0-05 to 0-07 long. Habitat. — Fossil in Barbados. 4. Anthospyris arachnoides, Haeckel. Petalospyris arachnoides, Haeckel, 1862, Monogr. d. Radiol., p. 294, Taf. xii. fig. 7. Shell nut-shaped, tuberculate, with slight sagittal stricture and irregular, polygonal pores. Basal plate with four large pores (?). Apical horn straight, conical, longer than the two curved lateral horns. Feet ten, slender, S-shaped, widely divergent, about as long as the sheU is broad. Dimensions. — SheU 0-05 long, 0-08 broad ; horns O'OS to 0-05 long, feet 0-08 long. Habitat. — Mediterranean (Messina), Atlantic, Station 354, surface. 5. Anthospyris aculeata, n. sp. (PI. 86, fig. 5). Shell campanidate, spiny, with deep sagittal stricture and irregular, roundish pores. On each side of the stricture three pairs of larger annular pores. Basal plate with two large square pores. The three horns of the same size as, and similar form to, the ten to fifteen feet, slender pyramidal, straight, divergent, about half as long as the shell. (This species is very variable and closely allied to Ceratospyris.) Dimensions. — Shell diameter 0-08 to 0-12 ; horns and feet 0-04 to 0-06 long. Habitat. — Central Pacific, Stations 266 to 274, surface. 6. Anthospyris doronicum, n. sp. (PI. 87, fig- 18). SheU nut-shaped, spiny, with a deep sagittal stricture and smaU circular pores. On each side of the stricture two pairs of very large square annular pores. Basal plate with four larger coUar (ZOOL. CHAIL. EXP. PART XL. — 1886.) Er 134 1066 THE VOYAGE OF H.M.S. CHALLENGER. l^ores and a coroua of numerous small peripheral pores. Three horns spindle-shaped, divergent' about half as long as the shell. Feet twenty-five to thirty, broad, lamellar, lanceolate, pointed divergent, nearly as long as the shell. Dimensions. — Shell O'l long, O'lS broad ; horns 0-06, feet 0-09 long. Habitat. — South Pacific, Station 296, depth 1825 fathoms. 7. Anthospyris tragopogo7i, n. sp. (PL 87, fig. 17). Shell nut-shaped, tuberculate, with distinct sagittal stricture and small regular circular pores. Basal plate with numerous small pores. Apical horn very large, spindle-shaped, twice as long as the shell ; frontal horns small, scarcely one-fourth as long, curved laterally. Feet twenty-five to thirty, three to four times as long as the shell, lamellar, lanceolate, pointed, parallel, vertical. Dimensions. — Shell 0'08 long. Oil broad ; apical horn 0'16, feet 0^2 long. Habitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms. Genus 465. Ceratospyris,^ Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Definition. — Zygospyrida with numerous (seven to twelve or more) basal feet and numerous coryphal horns. The genus Ceratospyris difi"ers from all the other Zj^gospyrida in the possession of numerous large spines on the surface of the shell, which usually exhibits only a small number of large pores or meshes. The lower spines which cover the inferior or basal face of the shell (usually nine to twelve or more) may be compared to the descending " basal feet " of the other Zygospyrida ; the upper spines, however, which cover the superior or coryphal face (usually six to nine, rarely more), may be regarded as " coryphal horns." In many species of this genus the lattice-work of the shell is of a peculiar loose kind, with few large meshes, resemblbig the wicker-work of the Plectanida. Subgenus 1. Lop)hosp)yris, Haeckel, 1881, Prodromus, p. 443. Definition. — Spines simple, not branched. Meshes of the shell usually polygonal, or roundish with polygonal frames. Bars of the network prismatic. 1. Ceratospyris polygona, n. sp. (PI. 86, fig. 1). Shell polyhedral, with deep sagittal stricture, studded with twenty-four to thirty long simple straight slender pyramidal spines, which are as long as the shell or longer. All pores large, polygonal. On the frontal and the occipital face two pairs of very large pores only, the superior ' Ceratospyris = Horned basket ; xsj^s, ffwvf/f. REPORT ON THE RADIOLARIA. 1067 pentagoual, larger than the inferior tetragonal. Basal plate with two triangular pores. Bars of the loose framework three-sided prismatic, thin. Dimcnsiom. — Shell 0-08 long, 012 broad ; spines 0'06 to 012 long. Habitat. — Cosmopolitan; Atlantic, Indian, Pacific, surface. 2. Ceratospyris pentagona, Ehrenberg. Ceratospyris pentagona, Ehrenberg, 1872, Abbandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. x. fig. 15. Shell polyhedral, with slight sagittal stricture, studded with twenty-four to thirty small simple conical spines, which are shorter than one-fourth of the shell. Most pores pentagonal. On the frontal and the occipital face two pairs of large pores only, the superior smaller than the inferior. Basal plate with four quadrangular pores. Bars of the network prismatic, thin. Dimensions. — Shell 0'07 long, Oil broad; spines O'Ol to 002 long. Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific, surface. 3. Ceratospyris allmersii, u. sp. (PI. 86, fig. 3). Shell polyhedral, with slight sagittal stricture, studded with thirty to forty prismatic spines which are not longer than half the shell. Most pores pentagonal. On the frontal face two, on the occipital three pairs of larger pores ; the inferior the largest. Basal plate with two rhomboidal pores (?). Bars of the network three -sided prismatic, thin. Dedicated to my dear friend, the excellent poet and naturalist, Hermann Allmers, of PLechtenHeth. Dimensions. — Shell 0'08 long, 012 broad ; spines O'Ol to 0'03. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. 4. Ceratospyris mulderi, n. sp. (PI. 86, fig. 4). Shell polyhedral, with deep sagittal stricture, studded with fifty to seventy prismatic spines ; two inferior (pectoral) spines about as long as the shell, the others much shorter. Pores polygonal. On the frontal and the occipital face one pair of very large pores. Basal plate with two distinctly hexagonal pores. Bars of the loose network prismatic. Dedicated to my dear friend, the excellent author and painter, Ludwig Mulder, of the Hague. Dimensions. — Shell O'O? long, 012 broad ; spines O'Ol to O^OS. Habitat. — Indian Ocean, Sunda Straits (Eabbe), surface. 5. Ceratospyris strasburgeri, n. sp. (PI. 86, fig. 2). Shell polyhedral, with slight sagittal stricture, studded with thirty to forty prismatic spines, which are about half as long as the shell (two or four inferior are longer). Pores roundish, with polygonal frames. On the frontal and occipital face two pairs of larger pores (the superior 1068 THE VOYAGE OF H.M.S. CHALLENGER. smaller). Basal plate with two large pentagonal pores. Bars of the network prismatic. Dedicated to my dear friend, the celebrated botanist, Professor Eduard Strasburger, of Bonn. Dimensions. — Shell 0'07 long, 01 broad ; spiues 0'02 to 0'04. Habitat. — Western Tropical Pacific, Station 225, depth 4475. 6. Ceratospyris mulleri, Stohr. Ceratospyris mulleri, Stohr, 1880, Paleeontogr., voL xxvi. Taf. iii. fig. 15. Shell polyhedral, with slight collar stricture, studded with forty to fifty pyramidal spines, shorter than half the shell. Pores circular, with pentagonal frames of the same breadth, all nearly of equal size. (Basal plate with four pores ?) Bars of the network prismatic. Dedicated to Johannes Miiller. Dimensions. — Shell 008 long, 01 broad ; spines O'Ol to 0'03. Habitat. — Fossil in Tertiary rocks of Sicily, Grotte (Stohr). 7. Ceratospyris krausei, n. sp. (PI. 86, fig. 10). Shell nut-shaped, with deep sagittal stricture, studded with forty to fifty strong conical spines ; six basal spines as long as the shell and two to three times as long as the others. Pores roundish polygonal, twice to three times as broad as the bars ; two pairs of larger pores on each side of the ring. (Basal plate with four large pores ?) Bars of the network rounded, thick. Dedicated to my dear friend, the excellent author, Ernst Krause (Carus Sterne), of Berlin. Dimensions. — Shell 0'06 long, 0'09 broad ; spines 0'03 to 0'08. Habitat. — "Western Tropical Pacific (Philippine Sea), Station 206, depth 2100 fathoms. 8. Ceratospyris preyeri, n. sp. (PI. 86, fig. 9). Shell nut-shaped, with slight sagittal stricture, studded with ten to twelve longer club-shaped spines (about as long as the shell) and nimierous smaller conical spines. Pores irregular, roundish, numerous ; two pairs of larger pores on each side of the ring. Basal plate with four large pores. Bars of the network rounded. Dedicated to my honoured friend and colleague, the celebrated investigator of psychical ontogeny. Professor William Preyer, of Jena. Dimensions. — Shell 0-07 long, 0-09 broad ; spines 0-02 to 0-08 long. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 9. Ceratospyris echinus, Ehrenberg. Ceratospyris echinus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. XX. fig. 12. Shell subspherical, with slight sagittal stricture, studded with numerous conical curved spines ; six basal and one apical spine are larger than the others, about as long as the shell. Pores numerous, small, circular. Basal plate with numerous pores. Bars of the network roundish. Dimensions. — Shell 0-05 long, 0-06 broad ; spines 0-02 to 0-05 long. Habitat. — Fossil in Barbados. REPORT ON THE RADIOLARIA. 1069 Subgenus 2. Cladospyris, Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Dejinition. — Spines forked or branched. Meshes roundish or polygonal. 10. Ceratospyris ramosa, Ehrenberg. Geratopyris ramosa, Ehrenberg, 1875, Abhaadl. d. k. Akad. d. \Vi.?s. Berlin, p. 66, Taf. xx. fig. 7. Cladospyris ramosa, Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Shell nut-shaped, with slight sagittal stricture, studded with numerous conical, irregularly branched spines. The largest about as long as the shell. Pores irregular, roundish ; on each side of the ring two pairs of larger pores. Basal plate with four pores. Bars of the network roundish. Dimensions. — Shell 0"06 long, 0"08 broad ; spines 0'02 to 0"08 long. Habitat. — Fossil in Barbados. 11. Ceratospyris carnerii, n. sp. (PL 86, fig. 11). Shell nut-shaped, with sharp sagittal stricture, studded with numerous pyramidal spines ; two basal spines are larger, as long as the shell, and irregularly branched. Pores polygonal ; on each side of the ring three pairs of larger pores. Basal plate with four large pores. Dedicated to my dear friend, the excellent monistic philosopher, B. von Carneri. Dimensions. — Shell 0-09 long, 012 broad ; spines 0-02 to O'OS long. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 12. Ceratospyris calorrhiza, n. sp. (PI. 87, fig. 19). Shell nut-shaped, with deep sagittal stricture, studded with numerous conical strong spines, about one-fourth as long as the shell. Basal spines irregularly branched, with root-like ends. Pores irregular, roundish, some larger pores on each side of the ring. Basal plate with four larger pores. Bars of the network rounchsh. Dimensions. — Shell O'l long, 0'14 broad ; spines 0*02 to 0'04 long. Hahitat. — Central Pacific, Station 27l, surface. Genus 466. Gorgospyris,^ Haeckel, 1881, Prodromus, p. 443. Dejinition. — Zygospyrida with numerous (seven to twelve or more) basal feet, without coryphal horns. The genus Gorgospyiis agrees with the three preceding genera in the possession of numerous basal feet, but differs from them in the complete absence of any horns on the coryphal face. It represents therefore the " hornless polypedal Zygospyrida,' and may ' Gorjiospi/ns = Medusiform basket ; yooyu, aTtvpi;. 1070 THE VOYAGE OF H.M.S. CHALLENGER. be derived from Petalospyris by loss of the original apical horn. The feet are commonly numerous, and often form a circle around the margin of the basal plate, similar to the circle of tentacles in many Medusse (Gorgon). Subgenus 1. Gorgospyriuni, Haeckel. Definition. — Feet simple, not branched. 1. Gorgospyris medusa, n. sp. (PI. 87, fig- !)• Shell hemispherical, papillate, with slight sagittal stricture and subregular circular pores. Basal plate with three large collar pores (by mistake not correctly represented in the figure). Ten to twelve slender feet, twice as long as the shell, strongly curved and divergent, of equal length. Dimensions. — Shell 0-06 long, 0-08 broad ; feet 0-1 long. Habitat. — North Pacific, Station 241, depth 2300 fathoms. 2. Gorgospyris medusetta, n. sp. (PI. 87, fig- 2). Shell nut-shaped, smooth, with deep sagittal stricture and irregular, roundish pores. Basal plate with three large collar pores, alternating with three pairs of smaller pores. Sixteen to twenty slender feet, about as long as the shell, slightly curved and divergent, of nearly equal length. Dimensions. — Shell 0-05 long, 0"08 broad; feet 0-05 long. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 3. Gorgospyris ehrenhcrgii, Haeckel. Petaloqjyris pentas, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berhn, p. 80, Taf. xxii. fig. 11. Shell nut-shaped, smooth, with sUght sagittal stricture and unequal circular pores. Basal plate with three large central pores, alternating with three pairs of smaller pores, and with a peri- pheral circle of smaller pores. Twenty-four to thirty short truncated feet, shorter than half the shell. Dimensions. — Shell 0'05 long, 0"07 broad ; feet 0"02 long. Habitat. — Fossil in Barbados. 4. Gorgospyns polypus, n. sp. (PI. 87, fig. 3). Shell hemispherical, papillate, with slight sagittal stricture and subregular circular pores. Basal plate with four larger and four alternating smaller pores. Feet sixteen to twenty, slender, curved, divergent ; four primary feet larger, twice to three times as long as the shell and the other feet. Dimensions. — Shell O'OS long, Q-l broad ; feet Ol to 0'2 long. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. REPORT ON THE RADIOLARIA. 1071 5. Gorgospyns eurycoljios, n. sp. (PI. 87, fig. 5). Shell nut-shaped, rough, with deep sagittal stricture and irregular, roundish pores ; two to three pairs of larger annular pores on each side of the stricture. Basal plate with four large collar pores. Feet eight, short, triangular, vertical, about one-fourth as long as the shell. Duiunsions. — Shell O'OS long, 013 broad ; feet 0-02 long. Hahitat. — Central Pacific, Station 270, depth 2925 fathoms. 6. Gorgospyris liriope, n. sp. (PI. 87, fig. 6). Shell nut-shaped, thorny, with sharp sagittal stricture and irregular, roundish pores. Two pairs of larger annular pores on each side of the ring. Basal plate with two very large circular pores only. Eight to ten short feet vertical, about one-fourth as long as the shell, with an elegant papillate knob at the distal end. Dimetisions. — Shell 0'07 long, 01 broad ; feet 0'02 long. Habitat. — South Atlantic, Station 323, depth 1900 fathoms. 7. Gorgospyris lamellosa, n. sp. Shell nut-shaped, tuberculate, with subregular circular pores. Basal plate with four larger and four alternate pairs of smaller pores. Feet fifteen to twenty-five, broad, lamellar, vertical, truncate, about as long as the shell, of irregular size and form, very variable. Dimensions. — Shell 0'07 long, 01 broad ; feet 0'05 to 01 long. Habitat. — Fossil in Barbados. Subgenus 2. Tliamnospyris, Haeckel, 1881, Prodromus, p. 443. Definition. — Feet divided or branched. 8. Gorgospyris schizopodia, n. sp. (PI. 87, fig. 4). Shell hemispherical, smooth, with slight sagittal stricture and small regular, circular pores. Basal plate with four large central and a circle of small pores. Feet fifteen to twenty, broad, lamellar, confluent at the base, about as long as the shell, irregularly divided or forked. Dimensions. — Shell O'OG long, 0-08 broad ; feet 0-05 to 0-08 long. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 9. Gorgospyris thamnopodia, n. sp. Thamnospyris thamnopodia, Haeckel, 1881, Prodromus, p. 443. Shell nut-shaped, tuberculate, with deep sagittal stricture and irregular, roundish pores. Basal plate with numerous small pores. Feet twenty to thirty, slender, curved, divergent, twice to three :imes as long as the shell, irregularly branched. Dimensions. — Shell 008 long, 012 broad ; feet 015 to 0-25 long. Halitat.^-lTi6i?i.Ti Ocean (Madagascar), Eabbe, surface. 1072 THE VOyAGE OF H.M.S. CHALLENGER. Subfamily 8. Circospyrida, Haeckel, 1881, Prodromus, p. 443. Definition. — Z ygospyrida apoda, without descending basal feet. Genus 467. Circospyris,^ Haeckel, 1881, Prodi-omus, p. 444. Definition. — Z ygospyrida without basal feet, with an apical horn. The genus Circospyris and the following closely allied genus Dictyosjjyris represent together the small subfamily Cii'cospyrida, difiering from all other Zj^gospjrridti a in the absence of feet on the basal face. They have probably arisen from the Tripos - pyrida (^Tripospyris) by reduction and loss of the feet (in the same way as the eradiate C y r t o i d e a from the triradiate). But it is also possible that many of the Circospyrida (if not all) are derived directly from the Semantida (Clathrocircus) by the closing of the two lateral openings and by completing the framework. 1. Circospyris micula, n. sp. (PL 95, fig. 13). Shell nut-shaped, compressed, smooth, with prominent sagittal ring. On each side of the ring three to four pairs of very large annular polygonal pores. Lateral pores small and numerous, roundish. Basal plate with two large pores only. Horn slender, conical, shorter than half the shell. Dimensions. — Shell O'll long, 013 broad. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. 2. Circospyris gigas, Haeckel. Dictyospyi-is gigas, Ehrenberg, Abhandl. d. k. Akad. d. Wiss. Berlin, p, 68, Taf. xix. fig. 6. Shell nut-shaped, tuberculate, with distinct sagittal stricture. On each side of the ring four pairs of larger annular pores. Lateral pores roundish, smaller. Basal plate with four large central and a circle of eight to twelve smaller peripheral pores. Horn cylindrical, about half as long as the shell (in the inverted figure of Ehrenberg directed downwards). Dimensions. — Shell Ol to 0'15 long, 0'15 to 0-2 broad; horn 0-05 to O'OS long. Habitat. — Fossil in Barbados. 3. Circospyris tridentata, Haeckel. Didyosjnjris tridentata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xix. fig. 10, a, b. Shell nut-shaped, smooth, with sharp sagittal stricture. On each side of the ring two pairs of large annular pores. Lateral pores roundish, smaller. Basal plate with six large pores. Horn slender, cylindrical, about as long as the shell, with three sharp teeth at the distal end. Dimensions. — Shell O'OS long, 0'05 broad ; horn 0'03 long. Habitat. — Fossil in Barbados. ^ Circospyris = Basket with a ring ; xi^xo;, aw^ii. REPORT ON THE RADIOLARIA. 1073 Genus 468. Dictyospyris,'^ Ehreuberg, 1847, Mouatsber. d. k. preuss. Akad. d. AYiss. Berlin, p. 54. Definition. — Z y g o s p y r i d a without basal feet, and without coryphal horns. The genus Dictyospyris, the last and simplest of the twenty-eight genera of Zygocyrtida, may be regarded either as a primordial ancestral form of this large family, or more probably as the last and most reduced form of it. In the former case the total absence of coryphal horns and basal feet is primary, in the latter case secondary, effected by phylogenetic reduction and loss. But it is also possible that in one part of the numerous species of this genus the former case, and in another the latter takes place, and that one part of Dictyospyris may be directly developed from the Semantida or Coronida (the lattice shell becoming complete), another part arising from the Tripospyrida or Dipospyrida (the horns and feet becoming lost). Subgenus 1. Dictyospyrantha, Haeckel. Definition. — Basal plate with two large pores only (the primary jugular pores of Semantis). 1. Dictyospyris distoma, n. sp. (PI. 89, figs. 11, 12). Shell nut-shaped, smooth, or somewhat tuberculate, with deep sagittal stricture. Pores not numerous, large, roundish-polygonal ; three pairs of large annular pores on each side of the ring. Basal plate with two very large pentagonal roundish coUar pores. Dimensions. — Shell 0'06 long, 0'08 broad. Habitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms. 2. Dictyospyris stalactites, n. sp. (PL 89, fig. 7). Shell nut-shaped, covered with irregular ramified tubercles (like stalactites), with deep sagittal strictirre. Pores not numerous, large, irregular, roundish. Two pairs of large triangular pores on each side of the ring (the inferior larger). Basal plate with two very large semicircular collar pores. Dimensions. — Shell 0"07 long, 0'09 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms ; also fossil in Barbados. ^ DictyospyTis = 'i\ei-hasket; iix.7voi, oa-i/j/j. (ZOOL. CHALL. EXP. PAET XL. 188G.) lir 135 1074 THE VOYAGE OF H.M.S. CHALLENGER. 3. Dictyospyris hiloba, n. sp. Shell subspherical, tuberculate, with slight sagittal stricture. Pores very numerous, small, circular. No larger pores on either side of the ring. Basal plate with two very large circular pores, surrounded by a circle of smaller pores. Dimensions. — Shell 0-07 long, 0-08 broad. Habitat. — North Pacific, Station 253, depth 3125 fathoms. Subgenus 2. Dictyospyrella, Haeckel. DeJinitio7i. — Basal plate with three large collar jDores (two paired posterior cardinal pores and an odd anterior sternal pore). 4. Dictyosjjyris triomma, n. sp. Shell nut-shaped, smooth, with deep sagittal stricture. Pores not numerous, large, polygonal roundish, two pairs of very large annular pores on each side of the ring. Basal plate with three large triangular pores. No free internal procolumeUa. Dimensions. — Shell 0'06 long, 0'09 broad. Habitat. — Indian Ocean, Zanzibar (Pullen), depth 2200 fathoms.. 5. Dictyosjjyris tristoma, Ehrenberg. Didyospyris tristoma, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. .xix. fig. 9. Shell nut-shaped, tuberculate, with slight sagittal stricture. Pores numerous, irregular, roundish. Three pairs of larger annular pores on each side of the ring. Basal plate with three large semi- circular pores (the sternal odd pore apparently halved by an internal free procolumeUa). Diyne'iisions. — Shell 0'05 long, 0'08 broad. Habitat. — Fossil in Barbados and Sicily (Caltanisetta). 6. Dicfyosjyyris triloba, Ehrenberg. Didyospyris triloba, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xix. lig. 8. Shell nut-shaped, spinulate, without external stricture, but with a complete internal sagittal ring. Pores numerous, subregular cii-cular ; no larger annular pores. Basal plate with three large, heart-shaped two-lobed collar pores. Dimensions. — Shell 0-05 long, 0'07 broad. Habitat. — Fossil in Barbados. REPOKT ON THE RADIOLARIA. 1075 7. Dictijos2)i/ris yi'jds, Biitsclili. ■ Dictyospi/ris gir/as, Biitsclili, 1880, Zeitsclir. f. wiss. Zool., vol. xxxvi., p. 539, Taf. xxxii. fig. 14a, 146. Shell subspherical, smooth, with a half (ventral) sagittal stricture, and a nearly complete internal ring. Pores very numerous and small, circular. No larger annular pores. Basal plate with three large collar pores (the sternal odd pore apparently divided into two jugular pores by the visible free procolumella. (Compare Circospyris (jigas, p. 10T2 = Didyosinjris cjigas, Ehreuberg). Bimeimons. — Shell 0"1 long, 014 broad. Habitat. — Fossil in Barbados. Subgenus 3. Dictyospyrissa, Haeckel. Definition. — Basal plate with four large collar pores (two larger posterior cardinal and two smaller anterior jugular pores). 8. Dictyosj^yris fenestra, Ehrenberg. Didyospyris fenestra, Ehrenberg, 1875, Abhandl. d.k. Akad. d. Wiss. Berlin, p. 68, Taf. xix. fig. 11. Shell nearly cubical, smooth, without extei-nal sagittal stricture. Internal sagittal ring complete. Pores small, roundish ; on each side of the ring two crossed pairs of large, square, equal, annular pores. Basal plate also with four longer pores of nearly equal size. JDimemions. — Shell 0"05 long, 0'07 broad. Habitat. — Fossil in Barbados. 9. Didyospyris tetrastoma, Ehrenberg. Didyospyris tetrastoma, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xis. fig."l2. Shell nut-shaped, tuberculate, with slight sagittal stricture. Pores numerous, irregular, rouiidish. No larger annular pores. Basal plate with foiu: large ovate coUar pores (the two cardinal twice as large as the two jugular pores). Dimensions. — Shell 0'05 long, 0'07 broad. Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific ; also fossil in Barbados and Sicily. 10. Dictyospyris spinulosa, Ehrenberg. Didyospyris spinulosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Beihn, p. 70, Taf. xix. fig. 13. 1 Ceratospyris borealis, Bailey, 1856, Amer. Journ. of Science and Arts, vol. xxii. pi. i. fig. 3. Shell nut-shaped, spinulate, without external stricture, with an internal free sagittal ring. Pores numerous, irregular, roundish ; on each side of the ring two pairs of very large square pores. Basal plate with four large collar pores. 1076 THE VOYAGE OF H.M.S. CHALLENGER. Dimensions. — Shell 0'07 long, 0'08 broad. Hahitat. — Central Pacific, Stations 271 to 274, depth 2350 to 2750 fathoms ; also fossil in Barbados. 11. DictyosiJyris mammillaris, n. sp. (PL 89, figs. 9, 10). Shell mammillate, nut-shaped, with deep sagittal stricture. Mammillfe of the surface hemi- spherical, with a conical apex. Pores not numerous, large, roundish. Two pairs of large pores on each side of the ring. Basal plate with four large jjores. Dimensions. — Shell 0"06 long, 0"08 broad. Hahitat. — ^Western Tropical Pacific, Station 225, depth 4475 fathoms. 12. Dictyospyris anthophora, n. sp. (PI. 89, fig. 8). Shell tuberculate, nut-shaped, nearly cubical, without external sagittal strictures. Pores not numerous, large, polygonally roundish. Bars between them compressed, elevated, with large, cam- panulate or flower-like tubercles on the nodal points. Basal plate with four large pores. Dimensions. — Shell 0'07 long, 0'09 broad. Habitat. — North Atlantic, Station 349, depth 2450 fathoms. 13. Dictyospyris quadriloba, n. sp.. Shell nut-shaped, smooth, with deep sagittal stricture. Pores numerous, small, circular, on each side of the ring three to four times as large as on the lateral sides. Basal plate with four very large collar pores and a circle of twenty to twenty-five very small peripheral pores. Dimensions. — Shell 0'08 long, O'll broad. Habitat. — Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms. 14. Dictyospyris messanensis, J. Miiller. Did)/oq>y7-is messanensis, J. Miiller, 1858, Abliandl. d. k. Akad. d. Wiss. Berlin, p. 46, Taf. ii. fig. 8. Dictyospyris messanensis, Haeckel, 1862, Monogr. d. Radiol., p. 291. Shell nut-shaped, spinulate, with deep sagittal stricture. Pores numerous and small, irregular roundish. No larger annular pores on the sides of the ring. Basal plate with four large, nearly equal, pear-shaped collar pores. Dimensions. — Shell 0"06 long, 0"08 broad. Habitat. — Mediterranean ; Messina, surface. Subgenus 4. Dictyospyromma, Haeckel. Definition. — Basal plate with six or more collar pores. REPORT ON THE RADIOLARIA. 1077 15. Dictyospyris hexastoma, n. sp. Shell nut-shaped, tubcrculate, with deep sagittal stricture. Pores small, irregular, roundish. Three pairs of larger pores on each side of the ring. Basal plate with six large pores; the middle pair (cardinal) twice as large as the anterior (jugular), and the posterior (cervical).. Dime7isio7is. — Shell 0'08 long, 0-12 broad. Habitat. — Fossil in Barbados. 16. Dictyospyris enneastoma, n. sp. Shell ellipsoidal, smooth, without external sagittal stricture, but with an internal free sagittal ring. Pores small and numerous, regular, circular. No larger annular pores. Basal plate with nine pores, three larger interradial alternating with three pairs of adradial. DivuiisioTis. — Shell 0-07 long. Oil broad. Habitat. — South Pacific, Station 297, depth 1775 fathoms. 17. Dictyospyris ^^olystoma, u. sp. Shell nut-shaped, mammillate, with cUstinct sagittal stricture. Pores small and numerous, irregular, on each side of the ring three to five times as large as on the lateral sides. Basal plate with twelve large pores (four central and four alternate pairs of peripheral). Dimensions. — Shell 01 long, 014 broad. Halitat. — Tropical Atlantic, Station 338, depth 1990 fathoms. Family LIII. Tholospyrida, n. fam. (PL 87, figs. 7-10 ; PL 89, figs. 1-4 ; PL 95, figs. 14-16). Definition. — S pyroidea with a galea, but without thorax ; the shell being composed of the bilocular cephalis and of an aboral cupola or galea arising from its coryphal face. The family Tholospyrida differs from the preceding Zygospyrida, its ancestral group, in the development of a galea, i.e., a fenestrated hemispherical or dome-shaped cupola, which covers the upper face of the cephalis like a cap. Only three species of this family have been hitherto described : Pylospyris (or Spyridobotrys) trinacria, figured in my Monograph (1862), Pylospyris (or Lithopera) denticiilata, figured by Ehrenberg (1872), and Lophosjyyr is (or Ceratospyris) acuminata, figured by Hertwig (1879). Fourteen new species have been found in the collection of the Challenger, which we dispose here among five genera. These may be derived from corresponding genera of Zygospyrida by the development of a galea. 1078 THE VOYAGE OF H.M.S. CHALLENGER. The numljer and disposition of the terminal feet around the basal plate do not vary so much in the Tholospyrida as in the Zygospyrida. We find here only one genus with three feet, Tliolospyris (corresponding to Tripospyris) ; one genus with two lateral feet, Lophospyris (corresponding to Dipospyris); and two genera with numerous feet, the horned Sepalospyris and the hornless Tiarosjyyris (the former corresponding to Petalospyris, the latter to Gorgospyi'is). The fifth genus [Pylospyris) has no feet at all, and may be derived from Circospyris among the Zygospyrida. The cephalis exhibits in the Tholospyrida the same typical structure which we have described above of all Spy ro idea (compare p. 1017). The cupola or galea, arising from its upper face, seems to be a secondary production, perhaps caused by an apical growth of the central capsule, or in other cases by descending branches of the apical horn, which cover the apical face of the calymma with protecting network. Synopsis of the Genera of Tholospyrida. I. Subfamily Lophospyrida. Two or three basal (cortinar feet). Galea " with a horn. II. Subfamily Tiarospyrida. Numerous basal feet in a corona (six to nine or more). ' Thi-ee basal feet (two paired pectoral and an odd caudal), Two paired basal (pectoral) feet, Galea with a horu, Galea without a horn, III. Subfamily Pylospyrida. No basal feet. Galea with a horn. 469. Tholospyris. 470. Lcrphoqjyri-i. 471. Sepalospyris. 472. Tiarospiyris. 473. Pylospyris. Genus 469. Tholospyris^ Haeckel, 1881, Prodromus, p. 441. Definition. — T h o 1 o s p y r i d a with three basal feet and an apical horu. The genus Tholospyris is probably the common ancestral form of the Tholospyrida, and has arisen from Triposp>yris by development of a galea or cupola; this is composed jf the apical horn, the lateral branches of which become connected with lateral spines arising from the coryphal face of the cephalis, and of lattice-work developed between the former and the latter. The thi'ee descending feet of the basal face are the typical cortinar feet (one odd caudal and two paii-ed pectoral), the same as in the old ancestral genera Cortina, Plagoniscus, Tripospyris,. &c. Subgenus 1. TJiolospyri^im, Haeckel. Definition. — Basal feet simple, neither forked nor branched. ' rAofcs2)jTO= Basket with a cuiiola ; 6ihoi, qtcv^I;. REPORT ON THE RADIOLARIA, 1079 1. TJioIosjii/ris trijiodiscus, n. sp. (PI. 89, fig. 1). Shell campanulate, smooth, as broad as long, with deep sagittal stricture. Cephalis com- pressed, with irregular roundish pores ; two or three pairs of larger annular pores on each side of the rmg. Basal plate with four large pores. Galea with two very large opposite holes (an occipital and a frontal opening). A slender free perpendicular columella connects the uppermost part of the sagittal ring with the strong three-sided pyramidal apical horn. All three feet of equal length, half as long as the ring, three-sided, prismatic, divergent, with three dentated edges. Dimensions. — Shell OlS diameter, ring 0-08 long, feet 0-05 long. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 2. Tliolospyris fenestrata, n. sp. (PI. 89, fig. 2). Shell roundish polyhedral, smooth, with slight sagittal stricture. Cephalis nearly cubical, with irregularly roundish pores ; two or three pairs of larger pores on each side of the ring. Basal plate with two very large pores. Galea pyramidal, with two large occipital holes. Columella enclosed in the dorsal wall of the galea, prolonged into an oblique pyramidal spine of the same length. Two pectoral feet pyramidal, nearly vertical and as long as the ring, twice as long as the caudal foot. Dimensions. — Shell 012 diameter, ring 0-07, pectoral feet 0-05 long. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 3. Tholospyris galeata, n. sp. Shell helmet-shaped, thorny, with deep sagittal stricture. Cephahs campanulate, with sub- regular circular pores. Basal plate with three large pores. Galea hemispherical, separated from the cephalis by a sharp horizontal stricture ; pores smaller. A slender free columella connects the apex of the ring with the strong conical apical horn, which is half as long as the ring. All three feet of equal length, divergent conical, as long as the horn. Dimmsions. — Shell 014 diameter, ring 0-09 long, feet 0'08 long. Habitat. — Central Pacific, Station 263, depth 2650 fathoms. Subgenus 2. TJiolospyridium, Haeckel. Definition. — Basal feet forked or brauched. 4. Tliolospyris rainosa, n. sp. (PI. 89, fig. 3). Shell helmet-shaped, smooth, with deep sagittal stricture. Cephalis nearly spherical, with irre- gularly polygonal pores ; four or five pairs of larger annular pores on each side of the strong angular ring. Cupola flat, conical, with two pairs of larger pores. Columella enclosed in its dorsal wall. 1080 THE VOYAGE OF H.M.S. CHALLENGEE. bearing an irregularly branched horn. Caudal foot short conical, simple. Two pectoral feet half as long as the shell, angular, subvertical, irregularly branched. Diviensioiis. — Shell 0"15 diameter, ring 01 long, pectoral feet 0'07 long. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 5. Tholospyris ciq^ola, u. sp. (PL 89, fig. 4). Shell pear-shaped or cupola-shaped, smooth, with shght sagittal stricture. Cephalis not distinctly separated from the galea, as the ring in the uppermost part of the shell-wall becomes obliterated. Pores irregularly polygonal, small and numerous. Basal plate with four large pores. Apical horn and the three divergent feet, irregularly branched ; feet nearly as long as the shell, about four times as long as the horn. Dimensions. — Shell 014 diameter, ring O'l long, feet 0'12 long. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. Genus 470. Lopliosioyris^ Haeckel, 1881, Prodromus, p. 443 (sensu emendato). Definition. — Tholospyrida with two lateral basal feet and an apical horn. The genus Lopliosinjris diflfers from the preceding Tlwlospyris, its probable ancestral form, in the absence of the caudal foot, and therefore bears to it the same relation that Dipospyris does to Tripospyris. The two pectoral feet are alone developed and are placed opposite in the frontal plane. Lophospyris may also be derived from Dipospyris by the formation of a galea. 1. Lophospyris dipodisciis, n. sp. (PL 95, fig. 14). SheU ovate, spinulate, with sharp transverse coronal constriction. Cupola hemispherical, half as large as the nut-shaped cephalis. Pores irregularly roundish, much larger on the sagittal constriction. Apical horn pyramidal, about half as long as the shell. Two lateral feet cylindrical, strongly curved, about as long as the shell, with some irregular branches ; together forming a nearly complete circle. Bimensions. — SheU 0'09 long, 0-08 broad; ring 0'04 long, feet 0-08 long. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 2. Lophospyris acuminata, Haeckel. Geratospyris acuminata, K. Hert\ng, 1879, Organisin. d. Radiol., p. 70, Taf. vii. fig. 2. SheU campanulate, smooth, without external transverse stricture. Cupola conical, half as long and broad as the nut-shaped cephalis. Pores irregularly roundish, on each side of the sagittal ' Lopliospyris = Basket vrith a crest ; Xo'to;, a-jrv^i;. REPORT ON THE RADIOLARIA. 1081 strictures much larger. Basal plate with four large triangular pores. Apical horn slender, prismatic ; its outer free part of the same length as the inner columella, and as the two lateral feet, which are curved, shorter than half the ring. Ditnensiojis. — Shell 008 long, 0-09 broad; ring 0'06 long; horn and feet 0"03 long. Habitat. — Mediterranean, Messina (E. Hertwig). 3. Lophospyris comosa, u. sp. Shell ovate, spiny, with deep transverse stricture. Cupola large, campanulate, nearly as long and two-thirds as broad as the nut-shaped cephalis. Pores irregular, roundish, of little different size. Basal plate with numerous (eight to twelve) similar pores. Apical horn large, nearly as long as the shell, surrovmded by a bunch of smaller divergent spines. Two lateral feet divergent, larger than the shell, cylindrical ; at the distal end irregularly branched, at the base surrounded by some smaller spines. Dimensions. — Shell 015 long, O'll broad; ring 0'08 long; feet 0"2 long.' Habitat. — Western Tropical Pacific, Station 206, depth 2100 fathoms. Genus 471. Sepalospyris,^ Haeckel, 1881, Prodromus, p. 443. Definition. — T holospyrida with numerous basal feet (eight to twelve or more). Galea with a horn. The genus Sepalospyris has been derived from the similar Petalospyris by development of a galea or cupola on the coryphal face of the cephalis, or from Tholospyris by multiplication of the basal feet. The latter (in the two observed species from twelve to twenty -five) form a regular corona around the basal plate. 1. SejMlospyris platyphylla, n. sp. Shell ovate, rough, with sharp transverse stricture. Cupola with dehcate network, hemi- spherical, about two-thirds as long and broad as the nut-shaped thorax. Pores of the latter irregular, roundish ; two or three pairs of large pores on each side of the sagittal stricture. Apical horn conical, half as long as the shell. Basal coronet with twelve to fifteen broad, lamellar, truncate, vertical feet, somewhat shorter than the cephalis. Dimensions. — Shell 012 long, 013 broad; ring 0'06 long; horn 0'04 ; feet 0-05 long. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 2. Sepalospyris iwlyphylla, n. sp. Shell campanulate, rough, with deep transverse stricture. Cupola hemispherical, about one- third as long and broad as the nut-shaped thorax. Pores irregular, roundish, a little different in 1 Sepalospyris = Basket with leaves ; ativcchor, »irt/j(V. (ZOOL. CHALL. EXP. — PART XL. — 1886.) Er 136 1082 THE VOYAGE OF H.M.S. CHALLENGER. size. Apical horn pyramidal, about as long as the shell. Basal coronet with twenty to twenty- five slender, lamellar, pointed, vertical feet, longer than the shell. Dimensions. — Shell Oil long, 0-12 broad; ring 0-07 long; horn 01; feet 012 to 018 long. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. Genus 472. Tuvrospyris,^ Haeckel, 1881, Prodromus, p. 443. Definition. — T h o 1 o s p y r i d a with numerous basal feet (eight to twelve or more). Galea without a horn. The genus Tiarospyris has probably been derived from the preceding Sepalosp)yris by reduction and loss of the free apical horn ; it therefore bears to it the same relation that the similar Gorgospiyris does to Petalospyris. 1. Tiarospyris pervia, n. sp. (PI. 87, fig. 7). Shell nut-shaped, smooth, with deep sagittal stricture. Cephahs on the lateral sides with numerous small roundish pores, on each side of the ring with a pair of very large holes. Basal plate with two large collar pores. Cupola flat, cap-shaped, with two large parietal pores above the ring. Coronet with eight conical, shghtly divergent feet, about one-fourth as long as the shell. Dimensions. — Shell 0-08 long, 01 broad ; ring 0'06 long ; feet 0-02 long. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 2. Tiarospyris galea, n. sj?. Shell hehnet-shaped, with deep sagittal stricture. Cephalis with irregular, polygonal pores ; on each side of the ring two paks of larger annular pores. Basal plate with four large pores. Cupola high, conical, nearly as long as the cephalis, separated from it by a distinct coronal stricture. Basal coronet with twelve to sixteen slender curved divergent feet, nearly as long as the shell. Dimensions. — Shell 016 long, 012 broad; ring 01 long; feet 015 long. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 3. Tiarospyris mitra, n. sp. (PL 87, figs. 9, 10). Shell subspherical, smooth. Cephalis on the lateral sides with small roundish, double- contoured pores, on each side of the ring with three to five pairs of larger pores, each of which is closed by a thin fenestrated lamella (different on the frontal face, fig. 9, and the dorsal face, fig. 10). Cupola flat, cap-shaped, separated by a distinct coronal stricture, with smaller pores. Basal coronet with ten to twelve short conical convergent feet. Diinciisio7is. — SheU Oil long, 012 broad; ring O^Ol long; feet 0-02 long. Habitat. — West Tropical Pacific, Station 225, depth 4475 fathoms. * J'mrosp)/m= Basket with a cap ; tj«««, a-Tiv^ii. REPORT ON THE RADIOLARIA. 1083 4. Tiarospyris amphora, n. sp. (PL 87, fig. 8). Shell amphora-shaped, iu the upper half smooth, in the lower spiuy, without external sagittal stricture. Cephalis subspherical, with a small number of . irregular, large, roundish pores, which are closed by a thin fenestrated lamella. Cupola flat, cap-shaped, with numerous small pores. Base covered with numerous conical divergent feet of different sizes, the largest one-third as long as the shell. Internal sagittal ring ovate, nearly free. Dimensions. — Shell 0-14 long, 0'13 broad ; ring Ol long ; feet 0'04 long. Habitat. — South Pacific, Station 285, depth 2375 fathoms. Genus 473. Pylospyris,'^ Haeckel, 1881, Prodromus, p. 443. Definition. — T li o 1 o s p y r i d a without basal feet, with an apical horn. The genus Pylospyris was first known from a Mediterranean species, called by me, in 1862, Spyridohotrys trinacria. As this name was given erroneously, on the supposi- tion of a near relation to the Botryodea ( = Polycyrtida), I changed it afterwards to Pylospyris. This genus differs from the other Tholospyrida in the total absence of basal feet, and may therefore be derived either from them by reduction of the feet, or from Dictyospyris by formation of a galea. 1. Pylospyris denticulata, Haeckel. Lithopera denticulata, Ehrenberg, 1873, Abhandl. d. k. Akad. d. Wiss. Berhn, p. 297, Taf. xii. II. fig. 7. Lifhobotrys denticulata, Ehrenberg, 1844, Monatsber. d. Akad. Berlin, p. 203. Shell spinulate, with sHght coronal and deep sagittal constriction, with irregidar, roundish pores of variable size. Galea hemispherical, about half as long and broad as the nut-shaped cephalis. No symmetrically disposed larger pores. Dimensions. — Galea 0-04 long, 0'06 broad ; cephalis 0'08 long, 01 broad. Habitat. — Antarctic Ocean, Ehrenberg. (Included iu the ice.) 2. Pylospyris trinacria, Haeckel. Spyridobotrys trinacria, Haeckel, 1862, Monogr. d. Radiol, p. 341, Taf. xii. figs. 8, 9. SheU tuberculate, with sharp coronal and sagittal stricture. Galea campanulate, with very small circular pores, and a short conical apical horn of the same length. Cephalis nut-shaped, with large, irregular, roundish pores ; two pairs of larger annular pores on each side of the sagittal ring, also four larger pores in the basal plate. Dimensions. — Galea O'OS long, 0'04 broad ; cephalis 0"04 long, 0'07 broad. Habitat. — Mediterranean, Messina, surface. 1 Pi/Zo.spyn's = Basket with gates ; ■!ri/X>i, sirvoi;. 1084 THE VOYAGE OF H.M.S. CHALLENGER. 3. Pylospyris canariensis, n. sp. (PI. 95, fig. 16). Shell rough, with deep coronal and slight sagittal constriction. Galea hemispherical, with numerous small irregular, roundish pores, about half as long as the cephalis, with a slender conical horn of twice the length. Cephalis nut-shaped, with larger roundish pores of very unequal size, three pairs of larger pores on each side of the ring. Basal plate with two larger pores. Dimensions. — Galea 0'03 long, 0'08 broad; cephalis 0-06 long, O'll broad. Habitat. — North Atlantic, Canary Islands, surface. Family LIV. Phormospyrida, Haeckel (sensu emendato) {PL 83, figs. 13-15 ; PL 95, figs. 17-19). Phormospyrida, Haeckel, 1881, Prodromus, p. 442. Definition. — S pyroidea with a thorax, without galea; the shell composed of the bUocular cephalis and of a simple thorax arising from its basal face. The family Phormospyrida differs from the Zygospyrida, their ancestral group, in the development of a thorax, or a second fenestrated shell-joint, which arises from the lower face of the cephalis. It corresponds, therefore, to the Dicyrtida among the Cyrtoidea, and may perhaps be, wholly or partially, the ancestral group of the latter. When the sagittal ring and the longitudinal constriction of the cephalis disappear, the Phormospyrida pass over into the Dicyrtida. Only three species of this famUy have been hitherto known, which were found fossil in Barbados, and described by Ehrenberg (1875) as Lithohotrys stiligera and Petalosjyyi-is conjiuens, and by Biitschli (1882) as Petalospyris anthocyrtoides. Fifteen other species are found in the Challenger collection, which we dispose here among five genera. Two of these five genera (the horned Acrospyris and the hornless Phormospyris) possess the three typical basal feet of Cortina and Tripospyris, and may be derived from these genera by the development of network between the bases of the feet. The three other genera possess numerous feet, and may be derived in the same way from the Polyspyrida; the apical face diff"ers in the three genera, in Desmospyris it is hornless, in Patagospyris it bears an apical horn, and in Rhodospyris three horns (an apical and two lateral or frontal). The cephalis in the Phormospyrida exhibits the same typical structure, which we have described above, of all Spyroidea (compare, p. 1017). The thorax or the second joint of the shell arises by reticular connection of the bases of the basal feet, and represents a cylindrical or truncate-conical joint in the polypodal forms, or a three-sided joint in the tripodal forms. The terminal aperture or the mouth of the thorax is constantly open, and surrounded by the free ends of the feet. REPORT ON THE RADIOLARIA. 1085 Si/nopsis of the Genera of Phormospyrida. I Quo apical horn, . I. Subfamily Acrospyrida. Three basal cortinar feet (one odd caudal | -^^ apical horn and two paired pectoral). J II. Subfamily Rhodospyrida. Numerous basal feet in a corona (nine to twelve or more). ' One apical horn, . Three apical horns, No apical horn, . 474. Acrospyris. 475. Phormosjjyris. 476. Patagospyris. 477. Rhodospyris. 478. Desniospyris. Subfamily 1. Acrospyeida, Haeckel, 1881, Prodromus, p. 441 (sensu emendato). Definition. — P liormospyrida with three basal feet (an odd caudal and two paired pectoral). Genus 474. Acrospyris} Haeckel, 1881, Prodromus, p. 441. Definition. — P hormospyrida with three basal feet and one apical horn. The genus Acrospyris is probably the oldest and most primitive among the Phor- mospyrida, perhaps the original ancestral form of this family. It has been derived from Tripos'pyris by the development of lattice-work between the three basal feet, forming a second joint or thorax. It has also therefore a close relation to the simj)lest forms of the triradiate Dicyrtida: Dictyophimus, Clathrocanium, &c. It differs from these in the distinct sagittal constriction of the cephalis, which divides it into two lateral loculi. 1. Acrospyris clathrocanium, n. sp. (PI. 95, fig. 17). Shell tuberculate, with distinct collar and deep sagittal stricture. Cephalis nut-shaped, with numerous irregular, roundish pores ; three pairs of larger annular pores on each side of the ring. Basal plate with four larger pores (two major cardinal and two minor jugular pores). Apical horn .slender, pyramidal, curved, about as long as the shell, with three recurved short spines. Thorax three-sided, about twice as large as the cephalis, with three large basal holes and a broad riband with numerous smaller holes ; three ribs between them stout, pyramidal, strongly curved, prolonged into three convergent crescentic feet. Dimemions. — Cephalis O'OS long, Oil broad; thorax 0-14 long, 016 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 2. Acrospyris dictyophimus, n. sp. Shell smooth. Cephalis and thorax of nearly the same structure and form as in the preceding species ; it differs from the latter in the shape of the three stout basal feet, which are ' ^CTOS2)i/m = Basket with an apical spine ; a*(i«, aw^i;. 1086 THE VOYAGE OF H.M.S. CHALLENGER. straight, much longer than the thorax, divergent, and at the broader base irregularly fenestrated, without three larger holes. Dimensions. — Cephalis 0'05 long, O'OS broad ; thorax 0-07 long, 012 broad. Habitat. — North Pacific, Station 241, depth 2300 fathoms. 3. Acrospyris p)yramidalis, n. sp. Shell three-sided pyramidal, with slight collar stricture. Cephalis campanulate, with deep sagittal stricture and stout ring, armed with a strong pyramidal horn of the same length. Thorax shorter and broader, truncate. Pores irregular, roundish, scarce. Three feet divergent, three-sided pyramidal, as long as the cephalis. Dimensions. — Cephalis O'Oo long, 0'06 broad ; thorax 0'02 long, 0-08 broad. Habitat. — Fossil in Barbados. 4. Acrospyris macrocephala, n. .sp. Shell spinulate, with deep sagittal and very deep collar stricture. Cephalis very large, nut- shaped, twice as long and broad as the small, truncate, pyramidal thorax. Pores irregxdar, roundish. Horn spindle-shaped, nearly as long as the cephalis ; the three divergent feet are of the same form and size as the horn, and arise as three ribs from the deep collar stricture. Dimensions. — Cephalis O'l long, 0'15 broad; thorax 0'05 long, 0"09 broad. Habitat. — Fossil in Barbados. 5. Acrospyris fragilis, n. sp. Shell very thin-walled and fragile, with deep sagittal and collar strictures. Pores very small and numerous, circular. Cephalis nut-shaped, nearly spherical, with a slender bristle-shaped horn of the same length. Basal stricture with two large collar pores only (luminella). Thorax nearly three-sided prismatic, longer than the cephalis, with three parallel riljs, prolonged into three slender, long, bristle-shaped feet. Dimensions. — Cephalis 0'05 long, 0'06 broad ; thorax 0'08 long, 0'06 broad. Habitat. — North Pacific, Station 244, surface. Genus 475. Phormosjyyris,^ Haeckel, 1881, Prodromus, p. 442 {sensu emendata). Definition. — P h o r m o s p y r i d a with three basal feet, without apical horn. The genus Phormospyris has been derived from Acrospyris, its ancestral form, by reduction and loss of the apical horn ; it therefore bears to the latter the same relation that Tristylospyris has to the ancestral Tripospyris. 1 PAonreo.'ipj/ns = Wicker- basket ; (po^fto;, a-Tru^ii. REPORT ON THE RADIOLARIA. 1087 1. Phormospyvis tricostata, u. sp. (PI. 83, fig. 15). Cephalis nut-shaped, thorny, with deep sagittal and collar strictures, half as large as the pyramidal thorax. Mouth of the latter dilated and cihated, twice as broad as the cephalis. Pores irregular, polygonal, with thin bars. Three cylindrical, straight, divergent ribs descend in the wall of the thorax, and are prolonged over the mouth into three short conical teeth. Dimensions. — Cephalis O'OG long, 0'09 broad ; thorax 0'08 long, 016 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 2. Phormospyris tridentata, n. sp. (PI. 95, fig. 18). Cephalis nut-shaped, with deep sagittal and collar strictures, about twice as large as the thorax. Mouth of the latter half as broad as the cephalis. Pores veiy small and numerous, subregular, circular. Collar plate with four large triangular pores. In the wall of the thorax three vertical prismatic ribs descend, which are prolonged over the mouth into three parallel feet of the same length. Dimensions. — Cei3halis 0'06 long, 0"08 broad; thorax 0'04 long, 0'06 broad. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 3. Phormospyris trifoUata, n. sp. Cephalis nut-shaped, with deep sagittal and collar strictures, smaller than the thorax. Mouth of the latter nearly as broad as the cephalis. Pores circular, double-contoured, larger in the thorax than in the eephaUs. The thorax has no lateral rilss, but bears around the mouth three large triangular lamellar terminal feet. Dimensions. — Cephalis 0'04 long, 0'05 broad; thorax 0-06 long, 0'05 broad. HaMtat. — Central Pacific, Station 271, depth 2425 fathoms. Subfamily 2. Ehodospyrida, Haeckel. Definition. — Phor mospy r ida with a corona of numerous (nine to twelve or more) basal feet. Genus 476. Patagospyris,^ Haeckel, 1881, Prodromus, p. 443. Definition. — P hormospyrida with numerous basal feet (nine to twelve or more) and an apical horn. The genus Patagospyris and the two following closely allied genera differ from the two preceding tripodal genera in the multiplication of the basal feet, and therefore have to the latter the same relation that the Polyspyrida {Petalospjyris) bear to the Tripospyrida {Tri-pospyris). When the numerous basal feet of Petalospyris become connected by lattice- work, Patagosp>yris arises. 1 Patojosp2/n's= Basket with a patiigium ; "iraTayuav, a'rzv^ls. 1088 THE VOYAGE OF H.M.S. CHALLENGER. 1. Patagospyris conjiuens, Haeckel. Petalospyris covfluens, Ehrenberg, 1885, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xxii. fig. 5. Shell tuberculate, with distinct sagittal and collar strictures. Pores irregular, roundish. Cephalis nut-shaped, larger than the short truncate thorax. Horn conical, shorter than the cephalis. Peristome with a coronet of twelve to fifteen short triangular feet, which are parallel and vertical, slightly curved and shorter than the thorax. Dimensions. — Cephalis 0-05 long, 0'07 broad ; thorax 0'0.3 long, 0'07 broad. Habitat. — Fossil in Barbadoes. 2. Patagospyris lanceolata, n. sp. Shell tuberculate, with slight sagittal and sharp collar strictures. Pores subregular, circular. Cephalis subsplierical, about as large as the truncate subcylindrical thorax. Horn spindle-shaped, about as long as the cephalis. Peristome witli a coronet of fifteen to twenty divergent lanceolate lamellar feet, longer than the thorax. Dimensions. — Cephalis 0'08 long, 0-09 broad; thorax 0'07 long, 0'07 broad. Habitat, — Fossil in Barbados. 3. Patagospyris stiligera, Haeekel. LHhohotrys stiligera, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berhn, p. 76, Taf. iii. fig- 17. Shell smooth, hyaline, with deep sagittal and collar strictures. Pores very small and few. Ceplialis nut-shaped, bilobed, of the same breadth as the cylindrical thorax. Horn conical, about as long as the cephalis. Peristome with a coronet of six to nine broad lamellar feet (in Ehrenberg's figure broken oft). Dimensions. — Cephalis 0"04 to 0-05 diameter ; thorax 0"06 long, 0'05 broad. Habitat- — Fossil in Barbados. 4. Patagospyris anthocyrtis, n. sp. (PL 95, fig. 19). Shell smooth, with deep sagittal and deep collar strictures. Pores irregular, roundish, of various sizes, numerous. Cephalis nut-shaped, with two inflated bosoms, about twice as broad as the short cylindrical thorax. Horn stout, pyramidal, about as long as the cephalis. Peristome with a coronet of fifteen to twenty parallel and vertical triangular lamellar feet, nearly as long as the thorax. Dimensions. — Cephalis 0-05 long, 01 broad ; thorax 0-04 long, 0-06 broad. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. Genus 477. Rhodospyris,^ Haeckel, 1881, Prodromus, p. 443. Definition. — P hormospyrida with numerous basal feet (nine to twelve or more), and with three coryphal horns. 1 iJ/iodospj/n's = Rose-basket ; piaou awoli. REPORT ON THE RADIOLARIA. 1089 The genus Rhodospyris differs from the preceding Fatagosi^yris in the development of three eoryphal horns (one odd middle apical horn, and two paired frontal horns on each of its sides), and therefore bears the same relation to the latter that the similar Anthospyris does to Petalospyris. When the numerous basal feet of Antho- spyris become connected by lattice-work, Rhodospyris arises. 1. Rhodospyris tricornis, n. sp. (PL 83, fig. 13). Cephalis nut-shaped, with deep sagittal stricture, and three short apical horns of half its length ; the middle odd horn is straight, the two paired lateral horns are curved outwards. Thorax some- what larger than the cephalis, dilated around the wide open mouth, with a coronet of twenty-five to thirty slender basal feet, which are slightly curved and convergent, about as long as the thorax. Pores small, numerous and circular. Dimensions. — -CephaUs O^OS long, 0'07 broad ; thorax 0'06 long, 0'08 broad ; horns 0'02 long, feet 0-06 long. Habitat. — Indian Ocean, Madagascar (Eabbe), surface. 2. Rhodospyris triceros, n. sp. Cephahs nut-shaped, with deep sagittal and deep collar stricture, and with three stout divergent horns of nearly equal length. Thorax cyUndrical, twice as long as the cephalis, and of the same breadth, with a coronet of twelve to sixteen broad, lamellar, rectangular, perpendicular feet around the mouth, about as long as the cephalis. Pores rather large, subregular, circxilar. Dimensions. — Cephahs 0"06 long, 0'08 broad ; thorax 012 long, O^OQ broad. Habitat. — Indian Ocean, Singapore (Trebing), surface. Genus 478. Desmospyris^ Haeckel, 1881, Prodromus, p. 443. Definition. — P h o r m o s p y r i d a with numerous basal feet (nine to twelve or more), without a eoryphal horn. The genus Desmospyris differs from the two preceding polypodal genera in the com- plete absence of horns on the eoryphal face of the cephalis. It therefore corresponds to Gorgospyris among the Zygocyrtida, and arises when the numerous basal feet of the latter become connected by lattice-work. 1. Desmospyris mammillata, n. sp. (PI. 83, fig. 14). Shell mammillate, with deep sagittal and slight collar constriction. Pores irregular, roundish. CephaUs nut-shaped, larger than the inversely conical thorax, and twice as broad as the constricted 1 Desmospyris = Basket with a band or string ; oiafios, aiiv^i;. (ZOOL. CHALL. EXP. PAET XL. — 1886.) Er 137 1090 THE VOYAGE OF H.M.S. CHALLENGER. mouth. Coronet of the peristome with twelve to fifteen short conical convergent feet, shorter than half the thorax. Dimensions. — Cephalis 0'06 long, 0-09 broad ; thorax 0-04 long, 0-06 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 2. Desmospyris cyrtocolpos, n. sp. Shell smooth, with deep sagittal and collar strictures. Pores subregular, circular, double-con- toured, very small and numerous. Cephalis nut-shaped, larger than the short truncate thorax. Coronet with eighteen to twenty-four slender, irregular, pointed, convergent feet, about twice as long as the thorax. Dimensions. — Cephalis 0'08 long, 0'12 broad ; thorax 0'04 long, O^l broad. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 3. Desmospyris anthocyrtoides, Haeckel. Petalosjryris antJiocijrtoides, Biitsclili, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. pp. 533, 539, Taf. xxxii. fig. 19, a-c. Shell tuberculate, with slight sagittal and sharp collar strictures. Pores subregular, circular. Cephalis nut-shaped, larger than the short truncate thorax. Coronet with fifteen to twenty short conical, parallel and vertical feet, about as long as the thorax. Dimensions. — Cephahs 0'06 long, 0'09 broad; thorax 0'02 long, 0-G7 broad. Habitat. — Fossil in Barbados. 4. Desmosp>yris carpocanium, n. sp. Shell smooth, with slight sagittal and shght collar strictures. Pores subregular, circular, small and numerous. Cej)halis campanulate, smaller than the ovate thorax. Coronet with fifteen to twenty irregular lamellar feet, which are longer than the thorax, pointed, nearly vertical and parallel. Dimensions — Cephalis 0*05 long, 0-08 broad ; thorax 007 long, 01 broad. Habitat. — South Pacific, Station 298, depth 2225 fathoms. Family LV. Androspyrida, n. fam. (PI. 88-90). Definition, — S p y r o i d e a with galea and thorax ; the shell composed of a bilocular cephalis and of two secondary joints, a galea arising from its upper face, and a thorax arising from its lower face. REPORT ON THE RADIOL ARIA. 1091 The fjimily A n d r o s p y r i d a differs from the three preceding families of S p y r- o i d e a in the three-jointed shell, in which the galea of the Tholospyrida and the thorax of the Phormospyrida are combined ; it may therefore be derived from the latter by develop- ment of a galea, or from the former by formation of a thorax. The common ancestral group of these three famihes is probably the Zygospyrida. But it may be that a part of the Androspyrida has originated directly from the S t e p h o i d e a. Two species only of this family were hitherto known, Amjihispyris reticulata (figured, in 1872, byEhrenberg, as Dictyospyiis) and Sphcerospyris sj^/iogra (described, in 1882, by Biitschli, as Dictyospyris). Thirty new species were found in the collection of the Challenger, and are here dis^^osed in seven genera. But perhaps these may represent three diflferent families, which we here enumerate as subfamilies ; the Lampros- pyrida, Perispyrida, and Nephrospyrida. The Lamprospyrida, the first subfamily, are tripodal Spyroidea with galea and thorax ; they may therefore be regarded as a combination of Tholospyris and Acrospyris. In the simpler form, Androspyris (PL 83, fig. 8), the network of the shell is simple, and allows a very clear recognition of the internal stritcture. In the splendid Lamp>rosp)yris, derived from it (PL 89, figs. 13, 14) the delicate network is more or less spongy. The large apical horn is branched and fenestrated in the latter and simple in the former. The Perispyrida, the second subfamily, possess no free apophyses, but a three-jointed shell wdth two distinct transverse strictures, an upper mitral and a lower coUar stricture. The network of this shell is incomplete in Amphisjyyris (PL 88, figs. 2-7), being- developed only in the frontal or lateral perimeter, thus making it prolial^le that this subfamily may have arisen directly from the Tympanida {Toxarium, PL 88, fig. 1 ; PL 93, figs. 18-20). The network of Tricolospyris (PL 88, figs. 8-11) is complete, of another shape in the cephalis than in the galea and thorax; it is doubled or spongy in Perispyris (PL 88, figs. 12, 13). The Nephrospyrida, the third subfamily, contains two very different genera only, each of which may represent a separate family. Sphwrospyris (PL 83, fig. 4) possesses a spherical or sulxspherical lattice-shell, the central part of which includes a sagittal ring, connected with the inner face of the sphere by a number of paired apophyses, correspond- ing to those of Lithocircus ; it may be easily confounded with some Sphseroidea {Caiposphcera), but the enclosed ring leaves no doubt as to its true origin. Nephrospyns (PL 90) has a flat discoidal shell of considerable size, usually kidney-shaped or cordate, with a deep sagittal incision at the base, indicating the region where the pseudojDodia are protruded from the porochora. The violin-shaped central capsule has two large lateral lobes on each side of the including sagittal ring, and the transverse nucleus is perpendicular to its sagittal plane (PL 90, figs. 7, 10). Sphcerocircus Si& w&\\ asNephro- spyris have probably arisen independently from the Stephanida. 1092 THE VOYAGE OF H.M.S. CHALLENGER. f I. Subfamily | Lamprospyrida. Three free basal feet. 11. Subfamily Perispyrida. No free basal feet. Shell three-jointed. III. Subfamily Nephrospyrida. No free basal feet. Shell spherical or discoidal. Synopsis of the Genera of Androspyrida. Lattice- work simple, not J Apical horn usually simple, spongy. not fenestrated, Lattice-work wholly or j Apical horn usually branched partly spongy. Shell with two transverse coronal strictures (one superior mitral and one inferior collar stricture). Shell without external trans- verse stricture. and fenestrated. Lattice-work only complete in the frontal ring, - Lattice-work complete on all sides, Lattice- work double orspongy, Shell spherical orsubspherical. Shell discoidal, kidney-shaped or subcircular. 479. Androspyris. 430. Lamxirospyris. 481. Amphispyris. 482. Tricoloqjyris. 483. Perispyris. 484. Sphcerospyris. 485. Nephrospiyris. Subfamily 1. Lamprospyrida, Haeckel. Defiyiition. — A ndrospyrida with three free basal feet (an odd posterior caudal foot and two paired anterior pectoral feet). Genus 479. Androspyris^ n. gen. Definition. — A n d r o s p y r i d a with three free basal feet and a simple apical horn ; lattice-work of the three-jointed shell simple, not spongy. The genus Androspyris is probably the most original form of the Androspyrida, and represents, together with the following Lampirospyris, the subfamily of Lamprospyrida, which always possess three free basal feet, an odd posterior or caudal foot, and two paired anterior or pectoral feet. It may be derived either from Acrospyris by develop- ment of a cupola, or from Tholospyris by development of a thorax ; the common ancestral form of these three typical genera is, no doubt, Triposj>yris. Some species of Androsp>yris reach a considerable size and are distinguished by a peculiar external form resembling somewhat a human figure. 1. Androspyris homunculus, n. sp. Shell thorny, with two deep transverse constrictions and irregular polygonal pores. Galea subspherical, with a strong pyramidal oblique horn, about two-thirds as large as the cephalis, which has the form of a human thorax, includes a strong ovate sagittal ring, and bears on each side a stronger lateral spine. Thorax short and broad, prolonged into three latticed divergent feet ; the 1 j4ndrosp?/ris = Man-like wicker basket ; av^f, anv^lf. REPORT ON THE RADIOLARIA. 1093 two lateral (pectoral) feet are like the legs of a human body, and are twice as long as the ceplialis and as the tail-like caudal feet. (The whole shell exhibits a curious similarity to a human figure, more than in the following nearly allied species.) Bimensioiis. — Length of the shell (including horn and feet) 0'4, breadth 0"1 to 015. Hahitat. — Central Pacific, Station 273, depth 2350 fathoms. 2. Androspyris anthropiscus, n. sp. (PL 83, fig. 8). Shell rough, with two distinct transverse constrictions and irregular polygonal pores. Galea ovate, with a slender conical oblique horn, about as large as the cephalis, which exhibits a deep longitudinal furrow in the sagittal dorsal line. Thorax half as long, prolonged into three short latticed feet; the terminal spines of the two lateral feet are vertical and parallel, that of the caudal foot larger, directed obliquely backwards. Bivieiisions. — Length of the shell (including horn and feet) 0"35, breadth 01 to 012. Hahitat. — Central Pacific, Station 271, depth 2425 fatlioms. 3. Androspyris ptithecus, n. sp. (PL 95, fig. 20). Shell smooth, with two slight transverse constrictions. Galea conical, with a short conical horn, longer than the nut-shaped cephalis. Thorax with three nearly vertical and parallel feet of equal length. Pores in the galea and thorax very small and numerous, circular, in the cephalis much larger, irregular, roundish. Dimensions. — Length of the shell (including horns and feet) 0"25, breadth 0"06 to 0'08. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 4. Androspyris aptenodytes, n. sp. Shell smooth, with two slight transverse constrictions and irregular, roundish pores. Galea hemispherical, with a short conical horn, about as large as the roundish cephalis and half as large as the ovate thorax. The three feet arise immediately beyond the collar stricture, are equal, divergent, curved, about as long as the cephalis, and are not terminal (as in the three preceding species), but lateral appendages of the thorax. Bimenswns. — Length of the shell 0'2, breadth O'Oo to 0-07. Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms. Genus 480. Lamprospyris,^ Haeckel, 1881, Prodromus, p. 447. i>ey^m'<{on.^-An drospy rida with three free basal feet and a fenestrated apical horn ; lattice-work of the three-jointed sheU wholly or partly spongy. The genus Lamprospy7is diffei-s from the preceding Androspyris, its ancestral form, mainly in the higher development of the lattice-work of the large shell. Whilst this in 1 ia«iyrospi/rw= Splendid wicker-basket ; 'ha/i-x^if, arv^ig. 1094 THE VOYAGE OF H.M.S. CHALLENGER. the latter genus is a simple lattice-plate, it here becomes more or less spongy, and some- times forms a very dense and delicate wickerwork. The apical horn and the three basal feet are commonly also fenestrated. The two annular strictures, which separate the cephalis from the conical cupola and the inflated thorax, are commonly not so distinct as in the preceding genus. Some species belong to the largest Spyroidea and reach more than half a millimetre in length. 1. Lamprospyris darwinii, n. sp. (PL 89, fig. 13). 'Shell nearly pear-shaped, with two distinct annular strictures, and uneven papillate surface. The total length is equal to twice the greatest breadth, and to seven times the length of the ring. Apical horn free, irregularly branched and fenestrated, as long as the included columella beyond it. The three diverging feet are strongly curved, S-shaped, and completely included by loose lattice-work. In the middle of their length they give off a simple strong lateral branch. The loose arachnoidal lattice-work is rather equally developed. Dimensions. — Length of the entire shell (including the apophyses) 0"5, greatest breadth 0'25, ring 0'07 long. Hahitat. — Central Pacific, Station 271, depth 2425 fathoms. 2. Lamprospyris lyellii, n. sp. Shell slender, pear-shaped, very similar to the preceding species, but differing in the following characters — the branched horn is much larger and twice as long as the columella ; the two annular transverse strictures (separating the three joints) are deeper. The free lateral branches of the three included feet are forked. Lattice-work looser than in the preceding species. Dimensions. — Length of the entire shell 0"6, breadth 0"2, ring 0'09 long. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 3. Lamprospyris huxleyi, n. sp. (PI. 89, fig. 14). Shell ovate, spiny, with two slight annular transverse strictures ; their length equal to one and a half times the breadth, and iip to seven times the length of the ring. Apical horn quite included by the loose lattice-work of the large conical cupola, which is as long as the cephalis and thorax together. The three slender feet are also included in the lattice-work and only one-third as long as the shell, nearly vertical. Lattice-work much denser than in the two preceding species. Dimensions. — Length of the shell 0-4, breadth 0-26, ring 0'06 long. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 4. Lamprospyris hookeri, n. sp. Shell ovato-conical, very similar to the preceding species, but smooth, not spiny. The apical horn and the three feet are much longer, not included in the network, but freely prominent, half REPORT ON THE RADIOLARIA. 1095 as long as the shell and nearly vertical, parallel. The arachnoidal lattice-work is much denser in the middle third (cephalis) than in tlie iipiier third (cupola) or the lower third (thorax). Dimamons. — Length of the shell (without appendages) 0-4:5, breadth O'S, ring O'OS long. ^a6ito;!.^Central Pacific, Station 270, depth 2925 fathoms. 5. Lamprospyris spenceri, n. sp. Shell slender, ovate, very similar to the preceding species ; differmg from it in the larger cupola, which is as long as the cephalis and thorax together. The three feet are much shorter and weaker, more divergent. This differs from aU four preceding species in the possession of a large double apical horn ; the two horns are strong, pyramidal, straight, strongly divergent, and as long as the cupola. Dimensions. — Length of the shell (without the appendages) 0"3, breadth 0'2, ring 0'05 long. Habitat. — Central Pacific, Station 2*72, depth 2600 fathoms. Subfamily 2. Perispyrida, Haeckel, 1881, Prodromus, p. 443. Definition. — ^Androspy rida without free basal feet, with three distinct joints separated by two parallel transverse strictures. Genus 481. Amphispyris,^ Haeckel, 1881, Prodromus, p. 444. Definition. — Androspyrida without free basal feet, with three distinct joints, separated by two transverse strictures ; lattice-work of the shell only complete in the frontal ring, with large open holes on the ventral and dorsal face. The genus Amphispyris and the tW'O following genera arising from it, represent together the peculiar small subfamily of Perispyrida. This may have originated directly from Toxarium (family Tympanida, PL 88, fig. 1 ; PI. 93, figs. 18-20), the large holes between its arches and rings becoming filled up by lattice-work ; in Am2)hispyris this intercalated network remains incomplete on the ventral and dorsal faces, whilst in Tricolospyris it becomes complete, and in Perispyris spongy. Subgenus 1. Amphispyrium, Haeckel. Definition. — On each side of the ring-plane three pairs of large annular meshes ; no middle zygomatic ring is developed between the two tympanic transverse rings (superior orbital and inferior maxillary ring). ' Amphispyris = Basket with a cap on both sides ; duSii, aisu^ii. 109G THE VOYAGE OF H.M.S. CHALLENGER. 1. Amphispyris thorax, n. sp. (PL 88, fig. 4). Shell thorax-shaped, as long as broad, with a deep sternal incision and two slight transverse strictures. On each side of the ring-plane three pairs of large, irregular, annular holes of nearly equal size, the middle holes nearly half as broad as the shell. No zygomatic bars between the orbital and maxillary bars. Lateral lattice-girdle narrow, with few small roundish meshes. Dimensions. — Shell 0'17 long, 0-17 broad, ring 0-06 long. Habitat. — Central Pacific, Station 270, depth 2925 fathoms. 2. Ainphisp)yris quadrigemina, n. sp. (PL 88, fig. 6). Shell shaped Uke the " corpora quadrigemina cerebralia," with two deep crossed strictures, a coronal transverse stricture and a sagittal sternal stricture. On each side of the ring plane three pairs of large, irregular, annular, double holes, the middle holes larger than the upper and lower holes, and about one-fourth as long as the shell. No zygomatic bars between the orbital and maxillary bars. Lateral lattice-girdle broad, with numerous small meshes. Dimensions. — Shell 0'13 long, 0"16 broad, ring 0'07 long. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 3. AmpMspyris reticulata, HaeckeL Dictyospyris reticulata, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. BerUn, p. 289, Taf. x. fig. 19. Shell thorax-shaped, one and one-fifth times as long as broad, with a deep sternal incision and two distinct transverse strictures. On each side of the ring-plane three pairs of large annular holes of nearly equal size, about one-third as long as the shell. No zygomatic bars between the orbital and maxillary bars. Lateral girdle narrow, witli few large polygonal meshes. Dimensions. — Shell 0'18 long, 0"15 broad. Habitat. — Indian Ocean, Zanzibar, depth 2200 fathoms (Pullen). Subgenus 2. Amp>hispyridium, HaeckeL Definition. — On each side of the ring-plane four pairs of larger annular meshes ; a middle horizontal zygomatic ring is developed between the two tympanic transverse rings (superior orbital and inferior maxiUary ring). 4. Amphisjjyris sternalis, n. sp. (PL 88, fig. 2). Shell thorax-shaped, one and one- fifth times as long as broad, with deep sternal incision and two distinct transverse (tympanic) strictures. On each side of the ring-plane four pairs of large irregular, annular holes ; the fourth (inferior or buccal) pair is the longest. The middle of the sagittal ring EEPOET ON THE RADIOLARIA. 1097 is crossed by horizontal zygomatic bars (between the ascending orbital and the descending maxillary bars). Lateral lattice-girdle narrow, with few large meshes. Dimensions. — Shell 0-24 long, 0-2 broad ; ring 0-09 long. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 5. Amphispyris subquadrata, n. .sp. (PI. 88, fig. 5). Shell compressed, nearly square, spiny, with slight sternal incision and two distinct transverse strictures. Similar to the preceding species ; four pairs of irregular annular pores of nearly equal size. Zygomatic ring complete. Lateral lattice-girdle narrow, with few large meshes. Dimensions. — Shell 014 long, 012 broad ; ring 0-06 long. Habitat. — Central Pacific, Station 285, depth 2275 fathoms. 0. Amphispyris costata, n. sp. (PL 88, fig. 3). Shell compressed, nearly square, with slight sternal incision and two obliterated transverse strictures. Similar to the two preceding species ; with four pairs of large annular pores, the two middle of which (the orbital and nasal holes) are much larger than the superior (frontal) and inferior (oral) holes. Zygomatic ring incomplete. Lateral lattice-girdle broad, with very numerous, smaU, irregular, polygonal pores. Dimensions. — Shell 0'2 long, 016 broad ; ring 0-07 Ions. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 7. Amphispyris toxarium, n. sp. (PI. 88, fig. 7). Shell inflated, with deep sternal incision and two distinct transverse strictures. Similar to the preceding species, but with deeper constriction and looser lattice-work. Four pairs of large, irregular, annular pores, the central two of which are much larger. Zygomatic ring complete. Lateral girdle broad, with iiTegular pores of very different size. Di^nensions. — Shell 0'2 long, 014 broad ; rino- 0-09 long. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. Genus 482. Tncolospyris,^ Haeckel, 1881, Prodromus, p. 443. Definition. — Androspy rida without free basal feet, with three distinct joints, separated by two transverse strictures ; lattice-work of the shell complete, simple. The genus Tricolospyris has arisen from the preceding Amphispyris, its ancestral form, by develoj)ment of lattice-work which completely closes the large open holes remaining on the ventral and dorsal faces of the latter. 1 JVicofosp2/"is= Wicker-basket with three joints ; rjixuAoj, nxv^if. (ZOOL. CHALL. EXP.— PART XL. — 1886.) Er 138 1098 THE VOYAGE OF H.M.S. CHALLENGER. 1. Tricolospyi'is kantiana, n. sp. (PI. 88, fig. 10). Shell smooth, one and a half times as long as broad, with two deep transverse strictures. Pores of the cephalis large, roundish, of nearly equal size. Cupola and thorax hemispherical, of about the same size and form, with numerous and small, double-contoured, roundish pores. Dimensions. — Shell 0-12 long, O'OS broad ; ring 0-04 long. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 2. Tricolospyris leibnitziana, n. sp. (PI. 88, fig. 9). Shell spiny, twice as long as broad, with two deep transverse strictures. Pores of the cephalis large, roundish, polygonally framed, of very different size ; two middle transverse rows of smaller pores enclosed between a superior and an inferior row of very large pores. Cupola and thorax hemispherical, about equal, with much smaller and very numerous roundish pores. Dimensions. — Shell 0'15 long, 0'07 broad ; ring 0"06 long. Habitat. — Western Tropical Pacific, Station 224, depth 1850 fathoms. 3. Tricolospyris baconiana, n. sp. (PL 88, fig. 8). Shell rough, twice as long as broad, with two sharp strictures. Pores of the cephalis large, very irregular, partly lobated. Cupola hemispherical, smaller than the campanulate thorax, both with smaller irregular pores. Dimensions. — Shell 015 long, 0'08 broad ; ring 0-06 long. Habitat. — Western Tropical Pacific, Station 215, depth 2500 fathoms. 4. Tricolospyris neivtoniana, n. sp. (PL 88, fig. 11). Shell spiny, slender, three times as long as broad, with two distinct strictures. Pores of the cephalis very large, irregular. Cupola hemispherical, only one-third as long as the slender inversely conical abdomen, both with irregular, much smaller pores. Dimensions. — Shell 0'22 long, O'OB broad ; ring 0'05 long. Habitat. — Western Tropical Pacific, Station 206, depth 2100 fathoms. Genus 483. Perispyris,^ Haeckel, 1881, Prodromus, p. 444. De^m'ft'on.— A u d r 0 s p y r i d a without free basal feet, with three distinct joints, separated by two transverse strictures ; lattice-work of the shell double or sjDongy. The genus Pe^ispyris diff"ers from the preceding Tricolospyris, its ancestral form, in the development of a secondary outer shell, which encloses the inner primary one either like an enveloping cortical shell or like a spongy veil. This is produced by the concrescence of meeting branches, which arise from spines of the inner shell. 1 Pmsp2/TO= Wicker-basket surrounded by an envelope ; ttsji, jwi/j/j. REPORT ON THE RADIOLARIA. 1099 1. Penspyris hicincta, n. sp. (PI. 88, fig. 13). Shell smooth, with two deep transverse annular strictures and a deep sagittal incision at the sternal base ; one and a half times as long as broad. Cephalis nut-shaped, with large irregular roundish pores and very broad bars. Everywhere from its surface there arise numerous slender arborescent radial beams; by the anastomoses of their ramified branches there arise the flat cap- shaped cupola and the larger bilobed thorax ; and also the external enveloping shell with loose delicate network. Dimensions. — Inner shell 017 long, 01 broad ; outer shell 0'23 long, 0"17 broad ; ring 0'06 long. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 2. Penspyris spongiosa, n. sp. Shell rough, with two distinct transverse strictures and a deep sternal incision, similar to the preceding ; the radial beams arising from the inner shell, and forming by anastomosing branches the outer shell, are thinner and more numerous, and the framework of the latter on the surface is very dense and spongy, therefore the shell is dark and not transparent. Dimensions. — Inner sheU 018 long, 012 broad ; outer shell 0'241ong, 018 broad ; ring 0-08 long. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 3. Perispyris lentellijosis, n. sp. (PI. 88, fig. 12). Shell smooth, lenteUiptical, with three different isopolar axes, perpendicular one to another. Transverse and sagittal strictures are wanting ; but the large enclosed ring and the two pairs of large adjacent annular meshes indicate clearly the position and size of the hidden cephalis. The two other joints (the cupola on the upper and the thorax on the lower pole of the cephalis) are nearly equal, cap-shaped or hemispherical. The outer lenteUiptical shell is little larger than the inner, connected with it by numerous thin bristle-shaped radial beams, and exhibits a delicate arachnoidal lattice-work. Dimensions. — Inner shell 015 long, 01 broad;, outer shell 018 long, 013 broad; ring O'OS long. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. Subfamily 3. Nephrospyrida (vel Paradictyida, Haeckel, 1881). Definition. — A ndrospyrida without free basal feet and external constrictions. SheU either spherical or discoidal. Genus 484. Sphcerospyns^ n. gen. Definition. — A ndrospyrida with a spherical or subspherical shell, without basal incision and transverse constriction ; without free basal feet. ' Sphtrrospyris = Spherical wicker-basket ; a^xi^ct, airv^i'i. 1100 THE VOYAGE OF H.M.S. CHALLENGEE. The genus Splmrospyris differs from all other S p y r o i d e a in the regular spherical or spheroidal form of the lattice-shell. It may therefore be easily confounded with some species of the Sphaeroidea; but the internal sagittal ring, placed in the median plane of the fenestrated sphere and connected with it by radial beams, leaves no doubt that it is derived from a true Spyroid, either Dictyospyris or Amphisjjyris, or another genus. Sometimes also four larger collar pores are visible. 1. Sphcerospyris sphcera, Haeckel. Dictyospyris sphcera, BiitscUi, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. pp. 511, 539, Taf. xxxii. fig. 15, a, h. Shell smooth, nearly spherical, slightly flattened at the base, with small regular circular pores. In the centre of the basal plate a regular rectangular cross with four equal collar pores. Dimensions. — Diameter of the shell Oil, of the enclosed ring 0'06. Habitat. — Fossil in Barbados. 2. Sphcerospyo'is quadriforis, n. sp. Shell rough, nearly spherical, shghtly flattened at the base, with small regular circular pores. In the centre of the basal plate a bilateral symmetrical cross with four ovate collar pores ; two cardinal pores twice as large as the two jugular pores and six to eight times as broad as the other shell-pores. Dimensions. — Diameter of the shell 0-26, of the enclosed ring 0'09. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 3. Sphcerospyris globosa, n. sp. (PI. 83, fig. 4). SheU smooth, perfectly spherical, with smaU subregular circular pores. In the centre of the basal plate no larger collar pores. (The original collar pores are here of the same size as the other pores, and cannot therefore be distinguished.) Dimensions. — Diameter of the shell 013, of the enclosed ring 0'06. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. Genus 485. Nephrospyris,^ Haeckel, 1881, Prodromus, p. 444. Definition — A ndrospyrida with a discoidal, kidney-shaped, or subcircular shell, with a basal incision ; without transverse constriction and free basal feet. The genus Nephrospyris is one of the most peculiar and most modified of the Spyroidea, of extraordinary size, in this respect surpassing aU other genera of this 1 Nephrospyris = Kidney-shaped basket ; mpjoV, avv^is. REPORT ON THE RADIOLARIA. 1101 suborder, and differing from them in its flat discoidal form. The diameter of the compressed shell often reaches one half millimetre or more ; its perimeter is elliptical or nearly circular, smooth, constantly with a characteristic deep sternal incision or a basal sinus on the basal pole of the main axis. The central sagittal ring is comparatively small. The margin is often inflated, like a delicate reticular girdle, and contains a large number of pecuHar spherical or roundish nucleated cells (PI. 90, figs. 6-10). Accord- ing to the observations of Dr. John Murray, made on living Nephrospyris, they are Vorticellina, perhaps constant Symbiontes. Subgenus 1. Nephrodictyum , Haeckel, 1881, Prodromus, p. 444. Definition. — Network of the shell simple, with bars of nearly equal breadth. 1. Nephrospyris renilla, n. sp. (PI. 90, figs. 9, 10). Shell kidney-shaped, one and a half times as broad as long, and three times as long as the deep kidney-shaped sternal incision. Ring with six pairs of branched apophyses, the bars of the apical pair vertical, of the basal pair divergent. The corresponding bars of the two middle pairs (on the frontal and the occipital face) form together on each side a large pentagonal or hexagonal naso-orbital area, which is surrounded by four or five large polygonal meshes ; the other meshes become smaller towards the inilated margin. All meshes simple, without arachnoidal fi'amework. Dimensions. — Shell 0"3 to 0"4 long, 0"4 to 0"5 broad ; ring 0'08 to 01 long. EaUtat. — Central Pacific, Station 272, depth 2600 fathoms. 2. Nephrospyris nephridium, n. sp. Shell kidney-shaped, one and two-third times as broad as long, very similar to the preceding species (or only a variety of it ?). Ring with seven pairs of branched apophyses. The large naso-orbital area is on the dorsal or occipital side simple, on the ventral or facial side divided by an equatorial pair of transverse horizontal branches into two superior orbital, and two inferior nasal holes. Sternal incision ovate. All meshes simple. DimcnsioTis — Shell 0-25 to 0-35 long, 04 to O'O broad ; ring O'O? to O'OS long. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 3. Nephrospyris phaseolus, n. sp. Shell kidney-shaped, twice as broad as long, very similar to the two preceding species (or only a variety of them ?). Ring with eight pairs of branched apophyses. The large naso-orbital area (between the mitral and collar ring) is on the dorsal and on the ventral side divided by two equatorial pairs of horizontal branches into two superior (orbital and occipital), and two inferior (nasal and suboccipital) holes. Sternal incision cordate. All meshes simple. Dimensions. — Shell 0"25 long, 0"5 broad ; ring 006 to 0'07 long. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 1102 THE VOYAGE OF H.M.S. CHALLENGER. 4. Nephrospyris cordata, n. sp. Shell heart-shaped, about as long as broad. Eing with six pairs of branched apophyses (as in Nephrospyris rcnilla, PL 90, fig. 9). No equatorial transverse branches. Sternal incision cordate, deeper than in aU other species of the genus, nearly half as long as the shell. All meshes of the network simple. Dimensions. — Shell 0-32 long, 0-36 broad; ring 0-05 to 0-06 long. Rabitat.^CentTal Pacific, Station 263, depth 2650 fathoms. Subgenus 2. Paradictytim, Haeckel, 1881, Prodromus, p. 444. Definition. — Network of the shell double ; the larger meshes separated by strong bars, and filled up by a very delicate secondary arachnoidal network. 5. Nephrospyris par adictyum, n. sp. (PI. 90, figs. 1-8). Paradidyum paradoxum, Haeckel, 1881, Prodromus et Atlas, loc. cit. Shell nearly circular, ten times as broad as the inflated marginal girdle, and three times as long as the sternal incision. Eing with six pairs of branched apophyses ; the bars of the apical pair nearly vertical, of the basal pair divergent ; the corresponding and opposite bars of the two middle pairs (on the occipital and on the frontal face) form together a large middle naso-orbital area ; above and below this lie six pairs of larger meshes. All larger meshes of the network are filled up by very delicate arachnoidal framework. The inflated and delicately reticulated marginal girdle of this and of the following closely allied species is usually filled up by nucleated roundish cells (fig. 7), which are Vorticellinse, according to the observations of Dr. John Murray on living specimens. Dimensions. — Diameter of the shell 0'5 to 0'6, of the marginal girdle 0-05 to 0"07 ; ring 0'07 to 0-09 long. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 6. Nephrosp)yris paradoxa, n. sp. Shell kidney-shaped, one and one-third times as broad as long, six times as broad as the inflated marginal girdle, and half as long as the sternal incision. Eing with six pairs of apophyses. Above and below the large naso-orbital holes lie ten pairs of larger meshes. All the meshes are filled up by very delicate arachnoidal network. Dimensions.— Length, of the shell 0-4 to 0-5, breadth 0-5 to 0-7 ; ring 0-06 to 0-08 long. Habitat. — Central Pacific, Station 270, depth 2925 fathoms. REPORT ON THE RADIOLARIA. 1103 Suborder II. BOTRYODEA, Haeckel, 1881 (PL 96). Pohjcyrtida, Haeckel, 1862, Monogr. d. Radiol., p. 341. Polycyrtida, Biitschli, 1882, Zeitschr. f. wiss. ZooL, vol. xxxwi. p. 519. Botryodea [ — Botrida vel Botryida), Haeckel, 1881, Prodromus, p. 439. Definition. — Nassellaria with a complete lattice -shell, exhibiting constantly a lobate and multilocular cephalis, with three to five or more separated lobes, and two to three or more constrictions. The suborder Botryodea differs from the other Cyrtellaria in the multi- locular and lobate shape of the cephalis, which is composed of at least three or four, often five or six, and sometimes even a greater number of lobes, which are separated by con- strictions and partly also by internal septa. This characteristic shape is found neither in the S p y r o i d e a (with bilocular cephalis) nor in the Cyrtoidea (with simple cephalis). The affinities of the former group to the two latter form a very complicated problem, which is not yet solved ; the morphology of the Botryodea is the most difficult part in the system of Nassellaria, and what we can here give, are incomplete and unsatisfactory beginnings only. Up to the year 1860 only a single genus of the Botryodea was known, Litho- hotrys, one of the oldest genera of " Polycystina," and described by Ehrenberg in 1844 (Mouatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 74). He gave the following definition : — " Loricse silice^ articuli in adulto non in seriem, sed in uvse brevis formam, id est in loculos plus minus discretos nonnuUos contiguos dispositi. Proxime ad Lithocampem accedit." In his first System (1847) Lithohotrys is placed with Liiliocampe among his family Lithochytrina. Afterwards (1860) Ehrenberg added two new genera, under the names Botryocanijje and Botryocyrtis and figured some species of these incompletely in his last works (1872, 1875). In my Monograph I founded for these three genera the separate subfamily of Poly- cyrtida, added as a fourth genus Sjoyridohotrys, and gave to the group the following definition (1862, loc. cit., p. 341): — " Lattice-sheU divided by two or more annular strictures, partly longitudinally, partly transversely, into three or more unequal chambers, which are placed in different planes and have a different relation to the poles of the shell-axis." The new and remarkable forms of Botryodea, which I subsequently found in the Challenger collection, demonstrated that the Botryodea differ from the other Cyrtellaria (the Cyrtoidea as well as the S p y r o i d e a) in a fiir higher degree than I formerly had supposed. A synopsis of the figures in PI. 96 will give sufficient evidence of this view. Therefore in my Prodromus (1881, ]). 439) 1104 THE VOYAGE OF H.M.S. CHALLENGER. I completely separated the B o t r y o d e a (or Botrida) from the other suborders of Cyrtellaria (Spyrida and C}Ttida). Biitschli gave, in 1882, in his paper on the Cyrtida {loc. cit.) a very accurate descrip- tion of Lithohotrys geminata, and pointed out its close affinity to Lithocorythium and Lithomelissa, and the importance of an oblique septum separating the cephalis into a smaller anterior and a larger posterior lobe. His views on the Botryodea (as a subordinate group of the C y r t o i d e a) are however incomplete, since the peculiar forms, described in the following pages, were unknown to him. According to the wide morphological divergence of the diiferent Botryodea, and the numerous peculiar forms developed from it, we here divide the whole group into three families and ten genera, with fifty -five species. These form, however, only a small part of the large and varied mass of closely related forms which are found in the rich collections of the Challenger. The great difficulty of researches on their intimate structure, and the great amount of time requii'ed for it, prevented me from giving a more complete and exact description than the one here given. The observation of the small shells from all the difierent sides is a difficult task, requiring years of work, and its satisfactory explanation would be possible only by means of numerous figures. The three families of Botryodea, here described, correspond to the three first groups of C y r 1 0 i d e a. The first family, Cannobotryida, corresponds to the Mono- C5rrtida clausa and to the Zygospyrida ; their shell consists of a cephalis only, wdthout subsequent joints. The second family, Lithobotryida, corresponds to the Dicyrtida and Phormospyrida ; their shell is composed of a cephalis and a thorax, both joints being separated by a transverse cortinar septum and a collar stricture. The third family, Pylobotryida, has a three-jointed shell, like the Tricyrtida, with cephalis, thorax and abdomen. The cephalis is the most characteristic part of the shell of the Botryodea and its lobulate and multilocular shape separates them from the Spyroidea and C y r- toidea. It represents the whole shell in the Cannobotryida, and in the young state of the two other families, which afterwards develop a thorax (Lithobotryida) and an abdomen (Pylobotryida). The typical lobulation of the cephalis is probably originally caused by internal septa ; and these may be originated by branches of the internal columella, which corresponds either to the central ascending columella of the Plectoidea or to the excentric ascending dorsal rod of the sagittal ring of the Stephoidea. But afterwards, when the original septa disappear and are lost by reduction, only the external constrictions remain to indicate the limits of the single lobes. Among the internal septa and the corresponding external constrictions which efi'ect the lobulation of the cephalis, may be distinguished primary or constant septa and secondary or inconstant septa. As primary septa we regard firstly an oblique frontal REPORT ON THE RADIOLARIA. 1105 septum aud secoudly a vertical sagittal septum. The frontal septum (described accurately by Biitschli) has usually two or three pairs of pores and ascends obliquely fi-om the base to the anterior face of the cephalis, where it is inserted in the orbital region ; it divides the cephalis into a smaller anterior or facial lobe and a larger posterior or occipital lobe. The latter is commonly higher and more developed than the former and partly covers its upper face, like the crest of a helmet. The facial lobe is again bisected by an incomplete sagittal septum and a corresponding partial constriction on the anterior face. We find, therefore, in this oi'iginal cephalis of the Botryodea, three primary lobes, an odd larger occipital lobe and two paired smaller facial lobes. The typical trilobed cephalis may be regarded perhaps as the common original form of the Botryodea. The secondary and inconstant constrictions which we find in many Botryodea, and which produce a greater number of lobes in the cephalis, require further accurate observation. The following cases of lobation may be considered as the most im- portant : — (1) Cephalis with four lobes, opposite in two pairs (two larger occipital and two smaller facial lobes, separated by a complete sagittal and an oblique frontal constriction) ; (2) cephalis with four unequal lobes, two of which are odd and sagittal, two paired and lateral (the odd occipital lobe usually larger and the odd mandibular lobe smaller than the two paired lateral or buccal lobes) ; (3) cephalis with five lobes (a large odd occipital lobe and two pairs of smaller lobes, anterior nasal, and lateral buccal lobes) ; (4) cephalis with five lobes, three of which are odd (a posterior occipital, middle frontal, and anterior facial lobe), and one pair of lateral lobes ; (5) cephalis with six lobes, opposite in pairs (two larger occipital, two smaller nasal and two intermediate lateral or buccal lobes); (6) cephalis with six lobes, two of which are odd and sagittal (a large occipital and a smaller nasal lobe), four opposite in pairs (two anterior and two posterior buccal lobes) ; (7) cephalis with seven lobes, three of which are odd (a large posterior occipital, a middle frontal, and an anterior small nasal lobe), four opposite in two pairs (an anterior buccal and a posterior temporal pair) ; (8) cephalis with eight lobes, two of which are odd (a large posterior occipital and a small anterior frontal lobe) and six opposite in three lateral pairs ; (9) cephalis with nine lobes, three of which are odd (an occipital, a frontal aud a nasal lobe) and six opposite in three lateral pairs ; (10) cephalis with ten lobes, two of which are odd (a large occipital and a smaller frontal lobe) and the other eight opposite in pairs; (11) cephalis with numerous lobes (twelve to fifteen or more) which are symmetrically disposed on each side of the median plane ; (12) cephalis with numerous lobes (twelve to fifteen or more) which are irregularly and sometimes spirally conglomerated. All these difi"erent forms of lobation require a far more thorough examination than I can devote to them, and may furnish examples of regular laws of development. The irregular forms are rather common, and I have found some very irregular Botryodea (ZOOL. CHALL. EXP. — PART XL. — 1886.) Rr 139 1106 THE VOYAGE OF H.M.S. CHALLENGER. (not here described) in whicli I could not determine the topographical regions of the cephalis. The difficulty in the examination of these complicated forms is increased by their very small size, which does not reach the usual dimensions of the other C y r t e 1- 1 a r i a. In some cases I was able to observe on the base of the cephalis the same typical cortinar pores (in two or three pairs), which we also find in the same part of the cephalis in the S p y r o i d e a and C y r t o i d e a, and which are inherited from the Semantida. The thorax of the B o t r y o d e a, or the second shell -joint, absent in the Cannobotryida, is usually of very simple form, ovate, truncate, conical or cylindrical, and consists of a secondary joint, developed from the base of the cephalis. The thorax is usually small, alwut the same size as the cephalis or a little larger, whilst in the Cyrtoidea it is commonly much larger than the latter. Its terminal mouth is closed by a lattice-plate in the Botryocellida, while it remains open in the Botryopylida and Pylobotryida. The abdomen, or the third shell -joint, developed in the Pylobotryida only, generally also exhibits a very simple shape, like the thorax, and it is a tertiary joint developed from the base of the thorax. It exhibits to the latter the same relation as in the Tricyrtida. The terminal mouth of the abdomen remains open in the Botryocyrtida ; it becomes closed by a lattice-plate in the Botryocampida. The lattice-plate forming the shell of the Botryodea is usually very thin and fragile, with very small circular pores. These are often very numerous, at other times scarce, and sometimes nearly wanting, so that the shell appears hyaline. In this group there never occurs that great variety in form and size of the pores, which numerous Cyrtoidea and Spyroidea exhibit. The radial apophyses which are found in the majority of Botryodea seem to correspond in position and relation to the typical radial beams of the other Nassellaria, viz., three descending basal feet arising from the base of the cephalis, and an ascending vertical apical horn arising from the top of the cephalis. Here also they seem to be inherited from the Plectoidea or Stephoidea ( Cortina, Cortiniscus). But whilst these four typical radial beams in the other Nassellaria are usually simple spines or solid rods, here they usually appear as hollow cylindrical tvibes, the thin wall of which is pierced by the same small pores as the shell. These porous tubes are either straight or slightly curved, often inflated and ovate at the base. We find in their number and disposition the same variety as in the simple radial spines of the other Nassellaria. The original number may here also be seen in the development of four typical beams, an ascending apical tube on the top of the cephalis, and three descending basal tubes on its base ; the odd posterior tube of the latter corresponds to the caudal foot, the two paired anterior to the pectoral feet. There is often also a fourth foot developed opposite to the caudal, and representing a sternal tube. Sometimes also two superior tubes are developed, a posterior occipital and an anterior frontal. The different REPORT ON THE RADIOLARIA. 1107 apophyses may be lost by reduction. I have never observed Botryodea with more than five apophyses. The Central Capsule of the Botryodea is not yet sufficiently known, no living species having been observed. In some preparations from specimens in the Challenger collections, stained by Dr. John Murray with carmine immediately after the dredging operation, single Botryodea are to be found in which the central capsule is deeply coloured. In Botryopera quinqueloba (PI. 96, fig. 2) it filled up the greater part of the cephalis and seemed to be divided into some small lobes. In Lithohotrys sphcBrothorax (PI. 96, fig. 15) it was divided into four lobes, three of which filled the ti'ilobed cephalis, the fourth large lobe occupying a great part of the spherical thorax. Details of their structure, unfortunately, were not recognisable. There can, however, be no doubt that they are the same as in all other Nassellaria. Synopsis of the Families of Botryodea. 1. Shell monothalamous, consisting of the loLate cephalis only, . . .1. Cannobotrtida. 2. Shell dithalanious, composed of a lobate cephalis and a simple thorax, . . 2. Lithobotryida. 3. Shell trithalamous, composed of a lobate cephalis, a thorax and an abdomen, . 3. Pylobotrtida. Family LVI. Cannobotkyida, Haeckel {sensu emendato). Cannobotryida, Haeckel, 1881, Prodromus, p. 440. Definition. — Botryodea monothalamia, the shell of which represents a lobate cephalis, without thorax and abdomen. The family C a n n o 1> o t r y i d a (retained here with a stricter definition than originally was given in my Prodromus) comprises those Botryodea, in which the whole shell is represented by the cephalis alone, u-ithout thorax and abdomen. Since the two latter joints, found in the two following families, are secondary productions, the Cannobotryida must be regarded as the ancestral forms of all B o t r y o d e a, in an ontogenetic as well as in a phylogenetic sense. Two species only of this family have been hitherto known, incompletely described by Ehrenberg as Lithohotrys triloba and Lithohotrys quadriloha. A great number of similar forms are to be found in the Radiolarian ooze of the Central Pacific, but they are very minute, and difficult to examine. We can describe here only twelve species of these, w^hich w^e arrange in two genera ; Botryopera without porous tubes, and Cannohotrys bearing a variable number of porous cylindrical tubes (one to five). The number of lobes of the cephalis is also variable in each genus (one to five or more). If in the future these minute and interesting shells should be better examined, it would 1108 THE VOYAGE OF H.M.S. CHALLENGER. be advisable to distinguish a number of genera according to the diflferent number of the porous tubes and of the lobes of the cephalis. The base of the latter is constantly- closed by a basal lattice-plate, and usually exhibits two or three pairs of cortinar pores, identical with those of the Semantida. The phylogenetic origin of the Cannobotryida may be found either in the Zygospyrida or in the Monocyrtida ; they differ from these two similar groups in the lobation of the cephalis, which is effected by the development of internal septa and external constrictions. Synopsis of the Genera of Cannobotryida. Cephalis without porous tubes, ....... 486. Botryopera. Cephalis with a variable number of porous tubes, ..... 487. Cannobotrys. Genus 486. Botryopera,^ n. gen. Definition. — C a n n o b o t r y i d a without tubes on the cephalis. The genus Botryopera is the simplest form among the Botryodea, the shell con- sisting of a lobate cephalis only, without tubes or radial appendages. It may be derived either from Dictyosp>yris or from Archicapsa by development of the horizontal fold in the frontal face of the shell, and the corresponding internal frontal septum, which separates the larger occipital lobe from the smaller facial half ; the latter may be divided again into paired frontal lobes, lateral buccal lobes, &c. Botryopera may be the common ancestral form of many Botryodea. 1. Botryopera cyrtoloba, n. sp. (PI. 96, fig. l). Cephalis trilobate ; the posterior odd occipital lobe helmet-shaped, about twice as large as the two paii'ed anterior frontal lobes, which are subovate and covered by the upper half of the former. Pores small and numerous, subregular, circular ; some larger pores at the base. DimeTisions. — Length of the shell 0'08, basal breadth 0'06. Habitat. — Central Pacific, Station 265 to 274, depth 2350 to 2925 fathoms. 2. Botryopera triloba, Haeckel. Lithohotrys triloba, Ehrenberg, 1854, Mikrogeol., Taf. xxii. tig. 30. Cephalis trilobate ; the occipital lobe subcylindrical, one and a half times as long as the two frontal lobes, which are slender, ovate and not covered by the former. Pores small and numerous. Dimensions. — Length of the shell 0-05, breadth O'OS. Habitat. — Fossil in Tertiary rocks of the Mediterranean (Sicily, Greece, &c.) ' Boirj/opera = Basket with grapes ; fiir^vi, Trti^x. REPORT ON THE RADIOLARIA. 1109 3. Botryojiera qiiadriloba, Haeckel. Lithohotrys quadriloba, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 84. Cephalis quadrilobate ; the occipital lobe helmet-shaped, one and a half times as long as the two paired hemispherical buccal lobes, and twice as large as the anterior frontal lobe. Pores not numerous, rather large, circular. Dimcnsioiis. — Length of the shell 0-06, breadth 0-04. Habitat. — Fossil in Barbados and North America (Virginia). 4. Botryopera qitinqueloba, n. sp. (PI. 96, fig. 2).. CephaUs quinquelobate ; the occipital lobe helmet-shaped, and twice as long as the two hemi- spherical frontal lobes, three times as long as the subspherical lateral buccal lobes. Pores scarce, small, circular. Bimemions. — Length of the shell 0-07, basal breadth 0-05. Habitat. — North Pacific, Station 253,,- depth 3125 fathoms, 5. Botryopera multiloba, n. sp, Cephalis multilobate ; the posterior odd occipital lobe ovate, and of about the same size as the anterior frontal half of the shell, which is clustered and divided into five to seven smaller lobes, an odd subspherical sternal lobe, and on each side of it two or three pairs of smaller subspherical lobes. Dimejisions. — Length of the shell 0'09, breadth 0'06. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. Genus 487. Cannobotrys,^ Haeckel, 1881, Prodromus, p. 440. Definition. — C annobotryida with, tubes on the cephalis. The genus Cannobotrys difi'ers from the preceding Botryopera in the development of hollow radial tubes, arising from the lobate cephalis in various numbers. According to their number the genus may be divided into various subgenera : (l) Cannobotrantha (monocanna) with a single apical tube ; (2) Cannobotrella (dicanna) with two divergent tubes, an ascending apical and a descending sternal one ; (3) Cannobotrissa (tricanna) with three tubes in the sagittal plane (an upper apical, a posterior caudal, and an anterior sternal) ; (4) Cannobotromma (tetracanna) with four radial tubes disposed like the four typical spines of Cortina (compare p. 950), and Cannobotrusa (pentacanna) with five radial tubes disposed like the five typical spines of Stephaniicm (p. 952). * (7anj«)5o{rys= Grape with tubes; navva, /iir^vi. 1110 THE 70YAGE OF H.M.S. CHALLENGER. Perhaps these five groups may be separated as five genera, possessing near relations to five very different genera of Nassellaria (Circosjjyris, Halicapsa, Archibursa, Cortina, StejihaJiium, &c. 1. Cannobotrys Tnonocanna, n. sp. ■ Cephalis trilobate, with a single cylindrical straight ajDical tube on the apex of the occipital lobe, which is helmet-shaped, and about one and a half times as long as the two subspherical frontal lobes. Pores small and numerous, subregular, circular. Biviensions. — Length of the shell 0'05, breadth 003. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. 2. Cannobotrys dicanna, n. sp. Cephalis quadrUobate, with two divergent tubes, an odd apical tube on the apex of the posterior occipital lobe, and an odd sternal tube on the anterior frontal lobe. Between these two odd lobes lie two paired lateral or buccal lobes, of about the same size. Shell nearly hyaline, with very few minute pores. Dimensions. — Length of the shell 0'06, breadth 0'04. Habitat. — Indian Ocean ; Madagascar (Eabbe), surface. 3. Cannobotrys tricanna, n. sp. (PL 96, fig. 3). Cephalis quinquelobate, with three curved cylindrical tubes in the sagittal plane ; an ascending apical tube on the apex of the helmet-shaped occipital lobe, and two horizontal tubes on the base of the shell (a posterior caudal, c, and an anterior sternal, z). The two frontal lobes are hemispherical, and twice as large as the two lateral buccal lobes. Pores very small and numerous. Dimensions. — Length of the shell 0'08, basal breadth O^OG. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 4. Cannobotrys sagittalis, n. sp. Cephalis multilobate, with three straight divergent cylindrical tubes in the sagittal plane ; a vertical apical tube on the apex of the ovate occipital lobe, and two horizontal tubes on the base, as in the preceding similar species ; it differs from the latter in the greater number of lobes (seven or nine), the two frontal lobes being divided into two or four secondary lobules. Dimensions. — Length of the shell 01, breadth 0-07. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 5. Cannobotrys cortina, n. sp. (PL 96, fig. 4). Cephalis quinquelobate, with four cylindrical nearly straight tubes of equal size ; an ascending, nearly vertical, apical tube on the apex of the occipital lobe, and three divergent descending tubes REPORT ON THE RADIOLARIA. 1111 on the base of the shell (an odd posterior caudal tube and two paired anterior pectoral tubes). The two lateral buccal lobes- are twice as large as the two anterior fi-ontal lobes, and half as large as the posterior odd occipital lobe. The four tubes in this and the following species correspond probably to the four spines of Cortina (p. 950). Dimensions. — Length of the shell 0'07, basal breadth 0'06. Habitat. — Central Pacific, Stations 263 to 274, depth 2350 to 2925 fathoms. 6. Cannohotrys tetracanna, n. sp. Cephalis multilobate, with four cylindrical curved tubes conical at their wider base, correspond- ing to those of the preceding species and to the four spines of Cortina. The odd occipital lobe is of about the same size as the anterior part of the shell, which is cleft into three pairs of roundish lobes, one pair of anterior larger frontal lobes, and two pairs of smaller lateral buccal lobes. Pores very few and minute. Dimensiom. — Length of the shell O'll, basal breadth 0'07. Habitat. — North Pacific, Station 253, depth 3125 fathoms. 7. Cannohotrys pentacanna, n. sp. Cephalis quinquelobate, with five cylindrical slender curved tubes, three of which are placed in the sagittal plane (a superior apical, a posterior caudal, and an anterior sternal), whilst the other two are paired and diverge laterally (two pectoral tubes). The five tubes correspond exactly to the five typical spines of Stephanium (p. 952). The helmet-shaped occipital lobe of the shell is twice as large as each of the two anterior frontal lobes, and three times as large as each of the two lateral buccal lobes. Pores numerous. Dimensions. — Length of the shell 007, basal breadth 004. Habitat. — ^Western Tropical Pacific, Station 225, depth 4475 fathoms. Family LVII. Lithobotryida, n. fam. Definition. — Botryodea dithalamia, the shell of which is composed of a lobate cephahs and a simple thorax, without abdomen. The family Lithobotryida comprises those Botryodea in which the shell is divided by a transverse annular constriction into a lobate cephalis and a simple thorax. They correspond therefore to the Dicyrtida among the Cyrtoidea, and to the Phormospyrida among the Spyroidea. The thorax, or the second shell-joint, is in all these three families a secondary production, arising from the base of the cephalis ; therefore the Lithobotryida must be phylogeneticaUy derived from the Cannobotryida. Several species of Lithohotrys were first described by Ehrenberg as Lithobotrys and Lithocorythium. These two genera are, however, identical, as has been 1112 ■ THE VOYAGE OF H.M.S. CHALLENGER. demonstrated by Biitschli (1882, loc. cit., p. 519). Some other species united by Ehrenberg with Lithohotrys belong to other genera. The number of Lithobotryida found in the " Radiolarian ooze " of the Challenger collection, is far greater than that of the Cannobotryida and Pylobotryida. But only a small part of them could be thoroughly examined and described here, so that their number may be greatly augmented by further accurate researches. We here arrange those forms in four genera, representing two different subfamilies. The terminal mouth of the thorax remains open in the Botryopylida, whilst it becomes closed by a lattice-plate in the Botryocellida. In each group there are shells with and without porous tubes. The number of these tubes, and also the number of lobes of the cephalis, is very variable, and may in future serve for the distinction of more genera. Synopsis of the Genera of Lithobotryida. I. Subfamily ( Cephalis without porous tubes, .... 488. Botryopyle. Botryopylida. ^, Mouth of the thorax open. ( Cephalis with a variable number of porovis tubes, . 489. Acrohotrys. ■R t ll'rl ' Cephalis without porous tubes, .... 490. Botryocella. ,,,.,, Cephalis ■with a variable number of porous tubes, . . 491. Lithohotrys. Genus 488. Botryopyle, Haeckel, 1881, Prodi'omu.s, p. 440. Definition. — L ithobotryida without tubes on the cephalis, and with the mouth of the thorax open. The genus Botryopyle comprises the simplest forms of Lithobotryida, the lobate cephalis bearing no tubes and the basal mouth of the thorax remaining open. It may be derived either from Dictyocephalus or from Desmospyris, by development of lobes on the cephalis and of an internal frontal septum, separating the larger occipital lobe from the smaller frontal half of the shell. The latter may be divided again into anterior frontal lobes, lateral buccal lobes, &c. 1. Botryopyle sethocorys, n. sp. (PI. 96, fig. 7). Cephalis trilobate, separated by a deep collar constriction from the hemispherical thorax, which is twice as broad. Occipital lobe helmet-shaped, little longer than the two hemispherical frontal lobes. Surface spiny. Pores irregular, roundish, of very ditferent size. Dimension's. — Length of the shell O'l, breadth 0'07. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. REPORT ON THE RADIOLARIA. 1113 2. Boiryopyle cribrosa, Haeckel. Lithobotrys cribrosa, Ehrenberg, 1875, Abhandl. J. k. Akad. d. Wiss. Berliu, p. 76, Taf. iii. fig. 20. ? Lithobotrys biceps, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 295, Taf. ix. fig. 23. Cephalis trilobate, separated by a slight collar constriction from the ovate thorax, which is somewhat smaller. Occipital lobe very large, helmet-shaped, longer than the thorax and twice as long as the two subspherical frontal lobes. Pores regular, circular, scarce. Dimensions. — -Length of the shell Oil, breadth 0-05. Habitat. — Fossil in Barbados. 3. Botryo^iyle cephalodes, Haeckel. Lithocorythiuin cephalodes, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berliu, p. 78, Taf. iv. fig. 6. Cephalis quinquelobate, separated by a slight collar constriction from the larger conical thorax, which is gradually dilated towards the wide mouth. Occipital lobe helmet-shaped, little longer than the frontal half of the cephalis, which is divided into two pairs of lateral chambers, corresponding to the four crossed pores of the sagittal septum, figured by Ehrenberg. The figure of the latter is inverse, seen from the frontal face, a part of the frontal wall having been broken off. DiTnensions. — Length of the shell 0-08, breadth 0-05. Habitat. — Fossil in Barbados. 4. Botryopyle dictyocephalus, u. sp. (PI. 96, fig. 6). CephaUs multilobate, separated by an obhque constriction from the subcylindrical thorax, which is somewhat larger and sUghtly curved. Occipital lobe conical, of the same length as the posterior part of the triangular frontal half of the shell, which is divided into five to seven lobes, two or three odd lobes in the median part, and one or two pairs of lateral lobes; very variable in size and form of the lobes. Mouth of the thorax wide, truncate. Dimensions. — Length of the shell 012, breadth 0'07. Habitat. — Central Pacific, Station 271 to 274, depth 2350 to 2750 fathoms. 5. Botryopyle inclusa, n. sp. (PL 96, fig. 5). Cephalis multilobate, campanulate, separated by a sharp constriction from the inflated thorax, which is nearly twice as long and broad. Both joints of the shell are irregularly lobate, with numerous vaulted lobes of different sizes, and partly internal septa. Pores small and numerous. Dimensions. — Length of the shell 01, breadth 0'06. Habitat. — Mediterranean (Candia) Spratt, depth 1620 fathoms. (ZOOL. CHALL. EXP. PAET XL. — 1886.) Er 140 1114 THE VOYAGE OF H.M.S. CHALLENGEE. Genus 489. Acrobotrys, Haeckel/ 1881, Prodromus, p. 440. Definition. — L ithobotryida with tubes on the cephalis, and with the mouth of the thorax open. The genus Acrobotrys differs from the preceding Botryopyle in the development of radial tubes, and from its probable ancestral form, Cannobotrys, in the development of a thorax, the basal mouth of which remains open. According to the varying number of the tubes we may distinguish the following five subgenera (corresponding to those of Cannobotrys), viz., (1) Acrobotrantha (monosolenia) with a single (apical) tube ; (2) Acrohotrella (disolenia) with two divergent tubes (an apical and a sternal) ; (3) Acrobotrissa (trisolenia) with three sagittal tubes (an apical, a caudal, and a sternal) ; (4) Acrobotromma {tetrasolenia) with four tubes, like the four tjrpical spines of Cortina ; and (5) Acrobotrusa {pento.solenia) with five feet, corresponding to the five typical spines of Stejjhatiium. 1. Acrobotrys monosolenia, n. sp. Cephalis trilobate, with a single straight apical tube, which ascends vertically from the apex of the occipital lobe, and is pointed at the distal end, with an anterior oblique aperture. Two frontal lobes paired, ovate, half as long as the helmet-shaped occipital lobe. Thorax ovate, twice as long as the cephalis. Pores very scarce. Dimensions. — Length of the shell 0"08, breadth 0'06. Habitat. — Mediterranean (Corfu), surface. 2. Acrobotrys disolenia, n. sp. (PI. 96, fig. 10). Cephalis trilobate, with three odd ovate lobes of nearly equal size in the sagittal plane and two divergent straight slender cylindrical tubes, a vertical apical tube on the occipital lobe, and a horizontal nasal tube on the frontal lobe; the middle lobe between them is somewhat smaller. Thorax ovate, about twice as large as the cephalis, with constricted mouth. Pores, small and numerous. Dimensions.- — -Length of the shell 0"1, breadth 0"06. Habitat. — Central Pacific, Station 265 to 274, depth 2350 to 2925 fathoms. 3. Acrobotrys aquaria, n. sp. Cephalis quinquelobate, with two divergent long cylindrical curved tubes. Occipital lobe helmet-shaped, with an ascending apical tube; -nasal lobe conical, with a descending sternal tube; ' ylcro6o(r2/s= Perfect grape ; axjoV, fior^v;. REPORT ON THE RADIOLARIA. 1115 between them a smaller odd middle lobe, and on each side of the latter an ovate frontal lobe. Thorax inflate, twice as long and broad as the cephahs. Pores small, scarce. Dimensions. — Length of the shell 0-09, breadth 0'07. Habitat. — South Pacific, Station 285, depth 2375 fathoms. 4. Acrohotrys acuminata, n. sp. (PI. 96, fig. 9). Cephalis sexlobate, with two divergent tubes. Occipital and frontal lobes ovate, odd ; between them a cupola-shaped apical lobe, bearing an ascending pointed apical tube. On each side at the base a small buccal lobe, and between the paired buccal lobes an anterior nasal lobe with a descend- ing curved sternal tube. Thorax smaller than the cephalis. Pores numerous and smaU. Dimensions. — Length of the shell O'll, breadth 0'09. EaMtat. — Central Pacific, Station 272, depth 2600 fathoms. 5. Acrohotrys auriculata, n. sp. (PL 96, fig. 11). Cephalis quadrUobate, with three pointed and auriculate tubes, two ascending apical (an anterior and a posterior) in the helmet-shaped occipital lobe, and a descending sternal tube on the base of the frontal lobe ; between the lobes two lateral paired buccal lobes. Thorax campanulate, twice as broad as the cephalis. Pores rather large and numerous. Dimeiisions. — Length of the shell O^l, breadth G'08. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 6. Acrohotrys trisolenia, n. sp. (PL 96, fig. 8). Cephalis quadrilobate, with four odd lobes and three divergent curved tubes, an ascending apical tube in the conical occipital lobe, and two descending tubes on the anterior and posterior basal lobes ; between these three lobes a small central lobe. Thorax ovate, about as large as the cephalis. Pores small and numerous. Dimensions. — Length of the shell Oil, breadth 0'05. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 7. Acrohotrys tetrasolenia, n. sp. Cephalis trilobate, with four slender cylindrical tubes. Occcipital lobe helmet-shaped, with an apical tube on the apex and a caudal tube on the base. Two frontal lobes ovate, prolonged into two paired pectoral tubes. The four tubes correspond in position to the four spines of Cortina. Thorax inflate, ovate, larger than the cephalis. Pores very scarce, rather large, irregular. Diviensio'ns. — Length of the shell 0-08, breadth 0-05. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 8. Acrohotrys pentasolenia, n. sp. Cephalis quinquelobate, with five short conical tubes ; three divergent odd tubes arise from three odd lobes ; an apical from the occipital lobe, a posterior caudal from the suboccipital lobe, and an 1116 THE VOYAGE OF H.M.S. CHALLENGER. anterior sternal from the nasal lobe. Two paired lateral tubes arise from the base of two ovate frontal lobes. The five tubes correspond in disposition to the five spines of Stcphanium. Thorax truncate. Pores small. Dimensions. — Length of the shell 012, breadth 0-09. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. Genus 490. Botryocella,^ Haeckel, 1881, Prodromus, p. 440. Definition. — L ithobotryida without tubes on the cephalis, and with the mouth of the thorax closed. The genus Botryocella differs from the closely allied Botryopyle in having the mouth of the thorax closed, and may be derived from it by development of a lattice-plate, effecting this closure. It bears therefore the same relation to the latter that Dicolocapsa has to Dictyocephalus. 1. Botryocella nucula, Haeckel. Lithohotrys nucula, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. iii. fig. 16. Ldthobotrys adspersa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. iii. fig. 15. Cephalis trilobate ; occipital lobe helmet-shaped, nearly twice as long as the two ovate frontal lobes. Thorax about as long as the cephalis. Pores very small and scarce. Dimensions. — Length of the shell 0-06, breadth 0'03. Habitat. — Fossil in Barbados. 2. Botryocella borealis, Haeckel. Ldthobotrys borealis, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 294, Taf. ii. fig. 3. Cephalis trilobate ; occipital lobe ovate, little longer than the two ovate frontal lobes. Thorax about twice as long as the cephalis. Pores very numerous and small. Dimensions. — Length of the shell 0'08, breadth 0'04. Habitat. — North Atlantic, Greenland, depth 1000 to 2000 fathoms. 3. Botryocella tricellaris, n. sp. Cephalis trilobate, with three odd sagittal lobes ; the middle or central lobe larger than the anterior frontal and smaller than the posterior occipital lobe. Thorax nearly spherical, about as long as the cephalis. Pores small and scarce. DimensioTis. — Length of the shell 0'08, breadth O'OG. Habitant. — North Atlantic, Station 353, depth 2965 fathoms. ' Botryocella =GTape-^umace ; /SoV^vf, KtKka.. REPORT ON THE RADIOLARIA. 1117 4. Botryocella quadricellans, n. sp. (PI 96, fig. 13). Cephalis quadrilobate ; the helmet-shaped occipital lobe twice as long as the two paired subspherical buccal lobes, and three times as long as the odd spherical frontal lobe. Thorax nearly- spherical, about as long as the cephalis. DimcnsioTis. — Length of the shell 01, breadth 0'05. Habitat. — Central Pacific, Station 272, depth 4475 fathoms. 5. Botryocella quadrigemina, n. sp. (PI. 96, fig. 14). Cephalis quadrilobate, with two pairs of lateral ovate lobes and complete sagittal constriction • the two occipital lobes nearly twice as large as the two frontal lobes. Thorax ovate, separated from the cephalis by a coUar septum with four cortinar pores (fig. 14). Dimensions. — Length of the sheU 0'09, breadth 0'06. Habitat. — Indian Ocean, Sunda Strait (Eabbe), surface 6. Botryocella multicellaris, n. sp. (PI. 96, fig. 12). Cephalis multilobate ; occipital lobe helmet-shaped, very large, about twice as long and broad as the frontal half of the shell, which is divided into six to eight small roundish clustered lobes. Thorax subspherical, of about the same size as the cephalis. Dimensions. — Length of the shell 0"1, breadth 0'05. Habitat. — South Pacific Station 297, depth 1775 fathoms. Genus 491. Lithohotrys,^ Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d.Wiss. Berlin, p. 74. Definition. — L ithobotryida with tubes on the cephalis, and with the mouth of the thorax closed. The genus Lithobotrys, the oldest and first known of the Botryodea, was founded by Ehrenberg in 1844, and was one of his five oldest genera of Polycystiua. It repre- sented by itself the suborder Botryodea until the year 1860. The numerous species described by Ehrenberg belong to very different genera of Botryodea, and partly also of Spyroidea. Following Butschli (1882) we retain here the name Lithobotrys iox those species, the type of which is Lithobotrys geminata. The genus Lithocorythium of Ehrenberg is for the greater part identical with it. When in the preceding genus Acrobotrys the mouth of the thorax becomes closed by lattice work, Lithobotrys arises. In the latter as well as in the former the number of tubes on the cephahs is difi'erent, and may characterise different subgenera. ' Lithohotrys=Sitone grape ; \itos, /SoV^t/f. 1118 THE VOYAGE OF H.M.S. CHALLENGER. 1 . Lithohotrys geminata, Ehrenberg. Ldthohotrys geminata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p 76, Taf. iii. fig. 19. Lithobotrys geminata, Biitschli, 1882, Zeitschr. f. wiss. ZooL, vol. xxxvL p. 519, Taf. xxxiii. fig. 27, a to c. ILithocoriithium platylophus, Ehrenberg, 1875, Abhandl. d. k, Akad, d. Wiss. Berlin, p. 78, \ Taf. iv. fig. 5. Cephalis trilobate, with a single apical tube in the ape.x of the helmet-shaped occipital lobe, which is one and a half times as long as the two subspherical frontal lobes. Thorax ovate, one and a half times as long as the cephalis, with few small pores in six to eight transverse rows. Dimensions. — Length of the shell O'l, breadth 0'05. Habitat. — Fossil in Barbados. 2. Lithohotrys lithocorythium, Haeckel. Lithocoryiliium oxylophus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, jj. 78, Taf. iv. figs. 3, 4. ILithopera oxystauros, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iii. fig. 6. Cephalis trilobate, with a single apical horn or a pointed tube in the apex of the helmet-shaped occipital lobe, which is a little longer than the two ovate frontal lobes. Thorax ovate, about as long as the cephalis, with very numerous and small pores. Dimensions. — Length of the shell 0"08, breadth 0'04. Habitat. — Fossil in Barbados. 3. Lithohotrys nasuta, Ehrenberg. Lithobotrys nasuta, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. iii. fig. 21. Cephalis quadrilobate, with a single descending sternal or nasal tube on the base of the anterior or frontal lobe, which is half as long as the helmet-shaped occipital lobe and twice as large as the two lateral buccal lobes. Thorax ovate, twice as long as the cephalis. Pores rather large, circular. Dimensions. — Length of the shell Oil, broad 0"05. Habitat. — Fossil in Barbados. 4. Lithobotrys ornata, Ehrenberg. Lithobotrys ornata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. iii. fig. 18. Cephalis quinquelobate, with two divergent ascending tubes, a posterior occipital and an anterior sternal or nasal tube. Occipital lobe campanulate, twice as large as the two frontal, and four times as large as the two buccal lobes. Thorax ovate, twice as long as the cephalis. Pores scarce and small. The specimen figured by Ehrenberg is very incomplete. Dimensions. — Length of the shell 0-09, breadth 0-05. Habitat. — Fossil in Barbados. REPORT ON THE RADIOLARIA. 1119 5. Lithohotrys sphwrothorax, n. sp. (PI. 96, fig. 15). CephaKs trilobate, with two divergent cylindrical tubes, an ascending apical tube in the apex of the ovate occipital lobe, and a descending sternal or nasal tube in the campanulate frontal lobe ; between the two lobes a smaller central lobe. Thorax spherical, twice as long as the latter. Pores very small, numerous. Bimensiom. — Length of the shell 0-08, breadth 0-06. Habitat. — Western Tropical Pacific, Station 225, depth 4575 fathoms. 6. Lithohotrys mascula, n. sp. (PL 96, fig. 16). Cephalis sexlobate, with two divergent cylindrical tubes, an ascending apical tube in the apex of the helmet-shaped occipital lobe and a descending sternal tube on the base, between the two kidney-shaped frontal lobes. The latter are half as large as the odd occipital lobe and of about the same size as the two inflated lateral buccal lobes, which are separated by a small odd nasal lobe. Dimensions. — Length of the shell 013, breadth 0'08. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 7. Lithohotrys orchidea, n. sp. (PI. 96, fig 17). Cephalis sexlobate, similar to the preceding species, but with five divergent and curved cylin- drical tubes, which correspond to the five spines of Stephanium ; an apical tube on the apex of the occipital lobe, a caudal tube on its base, a sternal tube between the two frontal lobes, and two paired pectoral tubes between the latter and the lateral buccal lobes. Pores small and scarce. Dimensions. — Length of the shell 012, breadth 0'06. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Family LVIII. Pylobotryida, Haeckel (sensu emendato). Pylohotnjida, Haeckel, 1881, Prodromus, p. 440. Definition. — Botryodea trithalamia, the shell of which is composed of a lobate cephalis, a thorax, and an abdomen. The family Pylobotryida comprises those Botryodea in which the shell exhibits two parallel transverse annular constrictions, and is divided by these into three successive joints, corresponding to the cephalis, the thorax, and the abdomen of the Tricyrtida. As in the latter, the abdomen is here also a later production, arising from the terminal mouth of the thorax; therefore the Pylobotryida must be derived phylogenetically from the Lithobotryida. Two genera of Pylobotryida were incompletely described in 1860 by Ehrenberg, Botryocyrtis and Botryocam^Je. We retain them here, with a stricter definition, how- ever. Two other genera were added in my Prodromus — Pylohotrys and Phormohotrys. 1120 THE VOYAGE OF H.M.S. CHALLENGER. The small number of species here enumerated may be easily increased, since numerous forms, belonging probably to this family, are not sufficiently known. Their study is, however, very difficult and requires accurate examination of the tiny shells from different sides. The four genera of Pylobotryida, here described, represent two different subfamilies. The terminal mouth of the abdomen remains open in the Botryocyrtida, whilst it becomes closed by a lattice-plate in the Botryocampida. There are in both groups shells with and without porous tubes; the number of these tubes, and also the number and disposition of the lobes in the cephalis, exhibit remarkable differences in the different species of those genera, and may in future serve for their division into a greater number of genera. Synopsis of the Genera of Pylobotryida. I. Subfamily ( Cephalis witliout porous tubes, . . . 492. Botryocyrtis. Botryocyrtida. ■' Mouth of the abdomen open. ( Cephalis with a variable number of porous tubes, . 493. Pylohotrys. II. Subfamily Botryocampida. Mouth of the abdomen closed by a lattice-plate. Cephalis without porous tubes, . . . 494. Botryocampe. Cephalis with a variable number of porous tubes, . 495. Phormobotrys. Genus 492. Botryocyrtis,^ Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 829. Definition. — P ylobotryida without tubes on the cephalis, and with the mouth of the abdomen open. The genus Botryocyrtis, founded by Ehrenberg upon two Indian species, is the simplest among the Pylobotryida. It may have been derived from Botryopyle by the development of an abdomen (or a third shell -joint), the mouth of which remains open. 1. Botryocyrtis serpentis, Ehrenberg. Botryocyrtis serpentis, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. x. fig. 21. Cephalis quadrilobate ; the odd frontal and the two paired buccal lobes subspherical, about half as large as the odd occipital lobe. Thorax inflated, about as long as the cephalis and half as long as the ovate abdomen. Mouth of the latter constricted, of half the breadth. DimensioTis. — Length of the shell 0'12, breadth 0'06. Habitat. — Indian Ocean (Zanzibar), depth 2200 fathoms, Pullen. 1 £oir2/oci/rtis= Basket with grapes ; ^otjk;, xv^tI;. REPORT ON THE RA.DIOLARIA. 1121 2. Botryocyrtis theocampe, n. sp. (PI. 96, fig. 19). Cephalis quadrilobate ; the odd frontal and the two paired buccal lobes hemispherical, about half as large as the helmet-shaped occipital lobe. Thorax cylindrical, of equal length and breadth, oue and a half times as broad as the cephalis and as the cylindrical abdomen. Pores rather large, irregular, roundish. Dmiensions. — Length of the shell 0"12, breadth 0-06. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 3. Botryocyrtis cerebellum, n. sp. (PI. 96, fig. 18). Cephalis quiuquelobate ; the odd frontal and the two paired buccal lobes ovate, about half as large as the two helmet-shaped paired occipital lobes (?). Thorax campanulate, twice as broad and long as the cephalis and as the truncate cylindrical abdomen. Dimensions. — ^Length of the shell 012, breadth 0'08. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 4. Botryocyrtis quinaria, Ehrenberg. Botryocyrtis quinaria, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. x. fig. 16. Cephalis quinquelobate ; the odd occipital lobe ovate, twice as large as each of the other four subsphericnl lobes, the two anterior (or frontal) of which are somewhat smaller than the two posterior (or buccal). Thorax campanulate, somewhat larger than the truncate abdomen. Pores rather large, irregidar. Dimensions. — Length of the shell 0'09, breadth 0'05. Habitat. — Indian Ocean (Zanzibar and Madagascar), surface. Genus 493. Pylobotrys,^ Haeckel, 1881, Prodromus, p. 440. Definition. — P y 1 o b o t r y i d a with tubes on the cephalis, and with the mouth of the abdomen open. The genus Pylohotrys differs from the closely allied Acrobotrys, its ancestral form, in the development of an abdomen or a third shell -joint, the basal mouth of which remains open. 1. Pylobotrys putealis, n. sp. (PI. 96, fig. 21). Cephalis multilobate, with a single curved and descending tube on the base of its anterior part (sternal tube). Occipital half of the cephalis di\'ided into three large odd lobes (the largest '■ Pi/to6oiri/s= Grape with an aperture ; •n/Aii, liiri^v;. (ZOOL. CHALL. EXP. PART XI.. — 1880.) Er 141 1122 THE VOYAGE OF H.M.S. CHALLENGER. the apical) ; facial half divided into three to five lobes, an odd frontal and one or two lateral pairs of small buccal lobes. Thorax truncate conical, about as large as the cephalis and larger than the truncate abdomen. Pores regular circular. Dimensions. — Length of the shell 012, breadth 0-08. Habitat. — Tropical Atlantic Station 347, depth 2250 fathoms. 2. Pylohotrys fontinalis, n. sp. (PI. 96, fig. 20). Cephalis trilobate, with three ovate lobes in the sagittal plane, of nearly equal size, and two divergent cylindrical tubes conical at the base. An ascending apical tube on the apex of the occipital lobe and a descending sternal tube on the base of the frontal lobe. The middle lobe between the former distinctly exhibits in the apical view (fig. 20) the collar septum with the four cortinar pores. Thorax campanulate, larger than the cephalis and the truncate abdomen. Dimensions. — Length of the shell Oil, breadth O^OG. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 3. Pylohotrys cerebralis, n. sp. (PL 96, fig. 22). Cephalis multilobate, with four divergent cylindrical tubes, which are cylindrical, obliquely truncate at the mouth, and correspond in position to the four typical spines of Cortina; an ascending apical tube and three descending basal tubes (an odd caudal and two paired pectoral). The helmet-shaped occipital lobe is about as large as the frontal half of the cejAalis, which is divided into three pairs of smaller pyriform lobes. Thorax subspherical, about as large as the cephalis and half as large as the inflated abdomen. Pores very scarce and small. Dimensions. — Length of the .shell 015, breadth 0'08. Habitat. — Indian Ocean, Cocos Islands, Eabbe, surface. Genus 494. Botryocampe} Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 829. Definition. — P ylobotryida without tubes on the cephalis, and with the mouth of the abdomen closed. The genus Botryocampe may be derived from Botryocyrtis by development of ;i basal lattice-plate, closing the terminal mouth of the abdomen. It is at the same time closely allied to the Tricyrtid Theocapsa, and may be perhaps derived from this liy lobation of the cephalis. 1 Boir2/oca?7vpe = Caterpillar with a grape ; /iar^v;, x.afi'xri REPORT ON THE RADIOLARIA. 1123 1. Botryocampe inflata, Ehrenberg. Botnjocampe inflata, Ehrenberg, 1861, Monatsber. d. k. Akad. d. Wiss. Berlin, p. 296 ; Abhandl. d. k. Akad. d. Wiss. BerHn, 1872, p. 285, Taf. ii. fig. 4. Botryocampe inflata, Haeckel, 1862, ]\Ionogr. d. Eadiol., p. 345. Lithohotnjs inflata, Bailey, 1856, Amer. Journ. Sci. aud Arts, vol. xxii. p. 1, pi. i. fig. 15. Cephalis trilobate, inflated, of about the same breadth and length as the tun-shaped thorax and the hemispherical abdomen. Frontal lobes of the cephalis ovate, a little smaller than the ovate odd occipital lobe. Pores numerous and small. Dimensions. — Length of the shell 0-05 to 008, breadth 0-02 to 0-04. Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, Stations 267 to 274, 241, 354, &c., surface, and in various depths. 2. Botryocampe theocajysa, n. sp. Cephalis trilobate, half as long as the campanulate thorax, and one-third as long as the ovate abdomen. Frontal lobes subspherical, scarcely half as long as the helmet-shaped occipital lobe. Pores very small and scarce. Dimensions. — Length of the shell 0'12, breadth 004. Habitat. — South Atlantic, Station 335, depth 1425 fathoms. 3. Botryocampe galea, Haeckel. Lifhohotrys galea, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 83. Lithocorythium galea, Ehrenberg, 1854, Mikrogeol., Taf. xxii. fig. 29, a, h. Litlwcorythium galea, Haeckel, 1862, Monogr. d. Radiol., p. 330. Cephalis quiuquelobate, about as large as the ovate thorax, and twice as large as the hemispher- ical abdomen (which is identical with the " crista obtusa finis anterioris " of Ehrenberg). Occipital lobe helmet-shaped, about twice as long as the two pairs of lateral lobes (the superior frontal and the inferior buccal lobes). Dimensions. — Length of the sheU O'OS, breadth 0'04. Habitat. — Fossil in Barbados. 4. Botryoca7nj)e rotalia, n. sp. (PL 96, fig. 23). Cephalis quiuquelobate, half as large as the campanulate thorax and the subspherical abdomen. Occipital lobe ovate, one and a half times as long as the two ovate frontal lobes, and three times as long as the two subspherical buccal lobes. Collar septum with six distinct cortinar pores (two anterior jugular, two middle cardinal and two posterior cervical, fig. 23). Dimensions. — Length of the shell 01, breadth 0'06. Habitat. — South Pacific, Station 295, depth 1500 fathoms. 1124 THE VOYAGE OF H.M.S. CHALLENGEE. 5. Botryocampe camerata, n. sp. (PL 96, fig. 24). Cephalis multilobate, about as long and half as broad as the irregularly campanulate thorax, which is half as long as the subspherical large abdomen. Occipital lobe of the cephalis helmet- shaped, larger than its uviform frontal part, which is divided into six to eight small subspherical lobes. In the interior of the thorax and abdomen irregularly branched rods are visible, which divide their inner space into compartments or incomplete chambers. Pores large, regular, circular, hexagonally framed. DimmsioTis. — Length of the shell 015, breadth 0'09. Ealitat. — Central Pacific. Station 271, depth 2425 fathoms. Genus 495. Pliormohotrys,'^ Haeckel, 1881, Prodromtis, p. 440. Definition. — P ylobotryida with tubes on the cephalis, and with the mouth of the abdomen closed. The genus Phormohotrys differs fi'om the similar and closely allied Pylobotrys in the development of a basal lattice-plate closing the terminal mouth of the thorax, and corresponds therefore to Lithohotrys among the Lithobotryida. As in the latter and in Cannohotrys, &c., so here in Phormohotrys, different subgenera may be distinguished, according to the different number and disposition of the radial tubes which become developed from the lobate cephalis. 1. Phormohotrys trithalamia, n. sp. (PI. 96, fig. 26). Cephalis trilobate, with a single apical tube, which is only one-third as long, spindle-shaped, pointed, with frontal opening. Frontal lobes ovate, two-thirds as long as the helmet-shaped occipital lobe. Internal frontal septum of the cephalis with four large pores. Thorax cylindrical, twice as long as the hemispherical abdomen. Pores small and numerous, irregular, roundish. DimensioTis. — Length of the shell 0'16, breadth O^OS. Hahitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Phormohotrys pentathalamia, n. sp. (PI. 96, fig. 27). Cephalis quinquelobate, with a single conical apical tube of the same length, which has an obliquely truncate frontal opening. Odd frontal and paired buccal lobes smaller than the sternal and the occipital lobe. Internal frontal septum with six large pores. Thorax inflated, a little larger than the subspherical abdomen. Pores subregular, circular. Dimensions. — Length of the shell 0'15, breadth 0"08. Habitat— Central Pacific, Station 272, depth 2600 fathoms. ' Phormohotrys = Grape basket ; (p6qf*o;, /ior^vg. REPORT ON THE RADIOLARIA. 1125 3. Phonnohotrys hexathalamia, Haeckel. Botryocarnpe hexathalamia, Haeckel, 1862, Monogr. d. Radiol., p. 344, Taf. xii. fig. 10. Cephalis sexlobate, with a single apical horn, which is solid, vertical, cylindrical, pointed, only one-third as long. Frontal lobes subcylindrical, nearly as long as the kidney-shaped occipital lobe, three to four times as long as the small buccal lobes and the odd sternal lobe. Thorax tun-shaped, smaller than the cephalis, larger than the hemispherical abdomen. Pores numerous, subregular, circular. Dimensions. — Length of the shell 013 to 015, breadth O'OS to 0-06. Habitat. — Mediterranean, Messina, surface. 4. Phormohotrys cannothalamia, n. sp. (PL 96, fig. 25). Cephalis trilobate, of about the same breadth and length as the campanulate thorax, which is three times as long as the flat cap-shaped abdomen. The middle (or central) lobe of the cephalis is simple, nearly cubical, and smaller than the ovate occipital and frontal lobe. The two latter are prolonged into two slender cylindrical divergent tubes. Pores small and very numerous. Dimensions. — Lengtli of the shell 01, breadth 0'05. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 5. Phormohotrys polythalamia, n. sp. Cephalis multilobate, of the same length and breadth as the subspherical thorax, and half as long as the ovate abdomen. Occipital lobe helmet-shaped, about as large as the frontal half of the cephalis, which is divided into six to eight lobes (two odd and two or three pairs of lateral lobes). Four cylindrical tubes corresponding to the four typical spines of Cortina, an ascending apical and three descending basal tubes (a posterior caudal and two anterior pectoral). Dimensions. — -Length of the shell 014, breadth 0'08. Habitat. — South Pacific, Station 298, depth 2225 fathoms. 1126 THE VOYAGE OF H.M.S. CHALLENGER. Suborder III. CYETOIDEA, Haeckel, 1862. Cijrtkla, Haeckel, 1862, Monogr. d. Radiol., pp. 272, 280. Cijrtoidea vel Cyrtida, Haeckel, 1881, Prodromus, pp. 425-439. Polycystina solitaria, Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, pp. 53, 54. Monodictya nassellaria, Ehrenberg, 1875, Abhandl. d. k. preuss. Akad. d. Wiss. Berlin, pp. 156, 157. Definition. — Nassellaria with a complete lattice-shell, exhibiting a simple or reduced cephalis, which is neither bilocular nor lobate, without sagittal constriction. The order Cyrtoidea, described by me in 1862 as the family Cyrtida, is by far the largest of all the main groups of Eadiolaria, and remarkable from the extraordinary variety of forms and the number of species. In the following system more than eleven hundred species are described, comprising about one-fourth of the number of species in the whole class of Radiolaria. This astonishing variety, however, is not effected by development of a large number of different types, but by an extraordinary variability within certain restricted boundaries, similar to what is seen among insects and birds. The number of genera, therefore, is comparatively small, and they may all be disposed into four families only, which in my Monograph (1862, p. 280) were distinguished as Monocyrtida, Dicyrtida, Tricyrtida and Stichocyrtida. If we divide these four groups in the following pages into twelve families and twenty- four subftimilies, we are guided by practical considerations only, hoping thereby to give a better survey of the difficult labyrinth of Cyrtoidean morphology. The Cyrtoidea are characterised by this wonderful richness of specific forms not only in the present seas, but also for millions of years in the former ages of our globe. The majority of all the fossil Radiolaria which are now known belong to this group, and many species of it are so common, that great rocks are formed b}^ their union. This fact was first observed by Ehrenberg, who in his first system of Polycystina (1847, loc. cit., p. 54) enumerated forty -four genera and two hundred and eighty -two species; the Cyrtoidea, his Polycystina solitaria, form the preponderant majority of the whole class, viz., twenty -five genera and one hundred and ninety-three species. In this first system (of 1847), as well as in the last systematic table of Ehrenberg (of 1875, loc. cit.), the Cyrtida as "Polycystina solitaria" are opposed to all other Radiolaria, as " Polycystina composita." The former bear the definition " Testae silicese spatio interno ample pervio, aut passim levius transverse constricto " ; the latter, however, " Testse silicese spatio interno cellulose aut strictura longitudinali constricto." In reality these definitions are insufficient, and the conclusions which Ehrenberg derived REPORT ON THE RADIOLARIA. 1127 from the organisation of the Polycystiua solitaria and composita, were quite erroneous. So also ai'e the definitions of the three families into which he divided the Polycystina solitaria, afterwards (in 1875) called by him " Monodictya nassellaria." These three families were the Halicalyptrina, Lithochytrina and Eucyrtidina. With these were also united the three genera of B o t r y o d e a known to Ehrenberg (Lithobotrys, Botryocampe, Botryocyrtis). We entirely separate these here from the true Cyrtida, on account of their lol)ate or multilocular cephalis. Whilst Ehrenberg only knew the skeleton of the Polycystina solitaria, the first observations of living Cyi'tida were published by Johannes Miiller, 1858, in his funda- mental treatise. He gave the first description and figures of the central capsule of tliis group, with the characteristic lobes developed from its basal part ; and of the pseudo- podia radiating on all sides [loc. cit., Taf. vi.). The forms described by him were all Mediterranean, one Dicyrtid (Lithomelissa mediterranea), two Tricyrtids [Eucyrtidium zancleum and Pterocanium charyhdeum), and one Stichocyrtid (^Lithocampe tropeziana). In my monograph (1862, p. 272—341) I gave a detailed description of all known and some new Cyrtida, and characterised this family by the fundamental monaxonial form of the shell, with two difterent poles (an upper apical and a lower basal pole), and by the unipolar growth, beginning from the apical pole. I pointed out also the peculiar structure of the monaxonial central capsule. At that time I divided the Cyrtida into five subfamilies, in which, however, the Spyroidea ( = Zygocyrtida), and the Botryodea ( = Polycyrtida) were united with the true Cyrtoidea (Monocyrtida, Diftyrtida, Stichocyrtida). The astonishing number of new and interesting forms of Cyrtida which I found in the rich collection of the Challenger (beginning from 1876), and mainly in the Radiolarian ooze of the Central Pacific (Stations 263 to 274), enabled me to give in my Prodromus, in 1881, a greatly enlarged and amended system of this important group. I separated there the Spyroidea ( = Zygocyrtida), and the Botryodea ( = Polycyrtida) from the true Cyrtoidea by restricted definition, pointing out the essential difi"erences in the structure of the cephalis in these groups of C y r t e 1 1 a r i a. The latter name, as here used, is therefore identical with the " Cyrtida " of my Monograph. In the Prodromus I divided the true Cyrtida (p. 426) into five sub- families and thirty tribes, corresponding to the differences in the number of the shell- joints and of the radial apophyses, and in the shape of the closed or open mouth. These groups are here retained, but reduced to four families and twenty-four subfamilies, since the Tetracyrtida are better united with the Stichocyrtida (compare below). Eichard Hertwig in his work Organismus der Radiolarien (1879, pp. 74 to 86) gave the fiirst accurate description of the finer structure of the central capsule of the Cyrtida, and pointed out their character as true Monopylea, with porochora and 1128 THE VOYAGE OF H.M.S. CHALLENGER. podoconus, and the peculiar shape of its nucleus. He also published excellent figures of some interesting new species. 0. Biitschli, 1882, in his valuable paper entitled: " Beitrage zur Kentniss der Radiolarien-Skelette, insbesondere der der Cyrtida" (Zeitsehr. fiir wiss. Zool., vol. xxxvi. p. 485) made an attempt at a natural classification of the Cyrtida, which he de- rived from the S p y r o i d e a or Zygocyrtida. As already mentioned above, we cannot accept this essay as the foundation of a true natural system, since the affinities of the Cyrtellaria (and of the Nassellaria as a whole) are far more complicated and difficult than Biitschli supposed. His views were supported by accurate observations only on the structure of the fossil Cyrtoidea of Barbados ; these, however, represent the minority only of the genera, and many interesting and important forms (mainly of true " Monocyrtida ") remained unknown to Biitschli. A great part, however, of his observations are very useful, and his remarks on comparative morphology are very suggestive. The Cyrtoidea may be divided into families and subfamilies according to three diff'erent principles, viz., (l) the number of joints into which the shell is divided by transverse strictures ; (2) the number of radial apophyses which arise from the shell ; (3) the shape of the basal mouth, which is either open or closed by a lattice-plate. At present every attempt of classification in this large group must be more or less artificial, since the afl&nities of the numerous smaller and larger groups are extremely complicated, and the ontogeny, the only sure guide in this phylogenetical labyrinth, is perfectly unknown. It seems therefore the most convenient to employ for our artificial classification, first, the number of shell-joints, second, the radial structure, and third, the shape of the mouth. A. The number of joints into which the shell is divided by transverse constrictions, serves here for the distinction of four primary groups or suborders of the Cyrtoidea, viz., (1) Monocyrtida with one joint ; . (2) Dicyrtida with two joints ; (3) Tricyrtida with three joints ; and (4) Stichocyrtida with four or more joints. In my Prodromus (1881, p. 426) I divided the latter group into Tetracyrtida (with four joints), and Stichocyrtida (with five or more joints); but these two groups may be united, since the fourth and all the succeeding joints are of rather indifi'erent shape and of little morpho- logical value. The three first joints, however, are usually very diff'erent and possess a high morphological importance, so that we distinguish the first joint as cephalis, the second as thorax, and the third as abdomen. The uppermost transverse constriction, which separates the two first joints, cephalis and thorax, is the collar stricture and is usually caused by an internal fenestrated septum, the cortinar septum. The second con- striction, which separates the second and third joints (thorax and abdomen) is called the lumbar constriction. The followmg constrictions (in the Stichocyrtida) are indifferent and of little morphological interest, and require therefore no peculiar designation. REPORT ON THE RADIOLARIA. 1129 B. The radial structure, indieaterl by radial apophyses arising from the rIicU, offers three principal diiferenccs, according to which the whole group of C y r t o i d e a may be divided into three large groups or sections, viz., (l) Pilocyrtida, or Cyrtoidea triradiata, with three radial apophyses ; (2) Astrocyrtida, or Cyrtoidea multiradiata, with numerous radial apophyses (four to nine or more) ; and (3) Coroc5^rtida, or Cyrtoidea eradiata, without external radial apophyses. The majority of Cyrtoidea are Pilocyrtida, with three radial apophyses, which are probably homologous to the three primary feet of the Plcctoidea and of Cortina (therefore " cortiuar feet "). The Astrocyrtida, or the Cyrtoidea with a variable number of radial apophyses (at least four to six) may be derived from the Pilocyrtida by interpolation of secondary or interradial apophyses between the three primary or perradial apophyses. The Corocyrtida, however, or the Cyrtoidea without external radial apophyses, may have originated by reduction and loss of the latter, either from the Pilocyrtida or from the Astrocyrtida. C. The shape of the basal mouth in the Cyrtoidea exhibits two essential diflferences only, viz., (l) the terminal mouth of the shell is a simple wide opening in the Stomocyrtida, or (2) the terminal mouth is closed by a lattice-plate, in the Clistocyrtida. As these two different cases occur in all the twelve families, which we have distinguished according to the differences in the number of joints and in the radial structure, we get altogether twenty-four subfamilies which are synoptically arranged in the following table : — Sj'nopsis of the four sections, twelve families and twenty-four subfamilies of CYRTOIDEA. PILOCYRTIDA. Cyrtoidea triradiata. (Three radial apophyses. ) ASTROCYRTIDA. Cyrtoidea multiradiata. (Four to nine or more apophyses. ) COROCYRTIDA. Cyrtoidea eradiata. (No radial apophyses.) Mouth of the shell. AjKTta. Clausa. Aperta. Clausa. Aperta. Clausa. MONOCYRTIDA. (Cyrtoidea monothalamia). Tripocalpida. PH.iENOCALPIDA. Ctrtocalpida. Arehipilida. Archiperida. Archiphormida. Archiphsenida. Archicorida. Archicapsida. DICYRTIDA. (Cyrtoidea dithalamia). Tripocyrtida. Anthoctrtida. Sethocyrtida. Setliopilida. Sethoperida. Sethophormida. Sethophsenida. Sethocorida. Sethocapsida. TRICYRTIDA. (Cyrtoidea trithalamia). PODOCTRTIDA. Phormocyrtida. THEOCYRTID.i. Theopilida. Theoperida. Theophormida. Theophsenida. Theocorida. Theocapsida. STICHOCYKTIDA. (Cyrtoidea polythalamia). PODOCAMPIDA. Phormocampida. LiTHOCAMPIDA. Stichopilida. Stichoperida. Stichophormida. Stichophsenida. Stichocorida. Stichocapsida. (ZOOL. CHALL. EXP. — PAET XL. 1886.) Er 142 1130 THE VOYAGE OF H.M.S. CHALLENGER. The cephalis, or the first shell-joint of the C y r t o i d e a, is in the majority homo- logons with the cephalis of the S p y r o i d e a, from which it differs iu the rednctiou of the sagittal ring and the absence of the corresponding sagittal constriction ; its cavity is therefore simple, not biloenlar. Its homology with the original cephalis of the S^p y r 0 i d e a cannot be doubted, when its base exhibits the typical basal pores of the Semantida. But in many cases these are wanting, and in a great number of C y r t o i d e a (mainly of Monocyrtida) there is more or less evidence that the original cephalis is lost, and that the real first joint is the thorax, the original second joint. At present it is quite impossible to distinguish between the former and the latter shells, and therefore in the following descriptions the first joint is always named cephalis and the second thorax. In future, when the affinities of the Cyrtoidea become better known, it will be necessary to distinguish the " Archicej^halis," or the true cephalis of all S p y r o i d e a and of the majority of Cyrtoidea, from the " Pseudocephalis " or the false cephalis of the minority {e.g., of many Monocyrtida aperta, Archipilida, Archi- phormida, Archicorida, &c.). The thorax, or the second shell -joint of the Cyrtoidea, is in the majority homo- logous with the thorax of the Phormospyrida and Androspyrida, and therefore developed by apophyses, which arise from the base of the cephalis and become united by transverse branches forming a lattice-plate. Its size is generally in inverse proportion to that of the cephalis. The more the cephalis becomes reduced, the more the thorax is developed. Its form is very variable, usually three-sided pyramidal or prismatic iu the triradiate, polyhedral in the multii-adiate, and conical or cylindrical in the eradiate Cyrtoidea. Its terminal mouth is either a simple wide ojjening, or closed by a lattice-plate. In the majority of C y r t o i d e a the thorax is separated from the cephalis not only by the external collar constriction, but also by the internal cortinar septum, a horizontal lattice-plate which exhibits the typical basal pores of the Semantida (usually two smaller jugular and two larger cardinal pores). But this septum is often reduced or perfectly lost, and then the external collar constriction alone indicates the se^iaration of the cephalis and the thorax. The abdomen, or the third shell-joint of the Cyrtoidea, absent in the Mono- cyrtida and Dicyrtida (as also in all S p y r o i d e a), occurs constantly in all Tricyrtida and Stichocyrtida. It is a simple large chamber in the Tricyrtida, but forms an annu- lated body, composed of a variable number of successive joints, in the Stichocyrtida. The constrictions between these joints, and also the lumbar constriction, between abdomen and thorax, are usually provided with a lattice-girdle, projecting into the cavity of the shell, like a diaphragm. Usually this horizontal girdle bears only a single circle of pores, rarely two or more. In many Cyrtoidea it is replaced by a solid horizontal ring of silex, and often it is wanting. It originates by the insertion of the following shell-joint, which takes place not on the terminal mouth of the preceding joint, but somewhat above it. REPORT ON THE RADIOLARIA. 1131 The aiiuular joints of the Stichocyrtida succeeding tlie third joint, and very variable in number, may be regarded either as a series of new postabdominal chamljers, succeeding the true abdomen, or as secondary joints of the annulated abdomen itself. The latter A-iew may be sustained by the fact that these joints are usually of an indif- ferent shape, and do not possess the characteristic features which we find in the first three joints, the abdomen, the thorax al^d the cephalis. The lattice-work of the shell exhibits in the C y r t o i d e a an extraordinary variety, similar to that of the Sphaeroidea; it serves in the first place for the distinction of species. The three first joints of the shell are often distinguished by the difi"erent char- acter of the lattice-work. The cephalis has usually very small and simple pores. The lattice-work of the thorax is often characterised by radial structures. The pores of the abdomen are usually very numerous and regular. The numerous joints in the annulated abdomen of the Stichocyrtida commonly exhibit little variety. The closure of the mouth, effected by a convex or horizontal terminal lattice-plate, has a different signification in the Monocyrtida and in the jointed C y r t o i d e a. In the Monocyrtida clausa this closing plate is the original cortiuar j^late or the basal plate of the cephalis. In the jointed Cyrtoidea, however, the lattice-plate which closes the terminal mouth of the thorax or of the abdomen (of the last annular joint in the Sticho- cyrtida), is produced by central union of the convergent edges, which grow centripetally from the margin of the mouth of the last joint towards its centre. The radial apophyses arising from the shell of the Cyrtoidea may probabl}' be always derived from that tripodal structure which is found in all P 1 e c t o i d e a, in Cortina and Cortiniscus among the Stephoidea, and in the majority of S p y r o i d e a. Therefore the prototype of this radial structure would be Plagoniscus and Cortina, with four radial spines united in a common point, the cortinar centrum ; an ascending apical horn and three descending basal feet. The odd posterior or caudal foot is usually similar in shape to the two paired anterior or pectoral feet, but may be distinguished from these latter by its relation to the apical horn. Very frequently an internal vertical free columella arises in the cephalis, or instead of it an ascending rib in the dorsal wall of the cephalis, which connects the base of the apical horn with the origin of the caudal foot. This is probably the remaining j)art of the sagittal ring. ]\Iore rarely also a part of the ventral rod of the latter is preserved, or on the anterior pole of the basal rod of the cephalis an ascending procolumeUa arises which is inserted on the frontal face of the cephalis, and sometimes prolonged into a nasal horn (the rod, C, of Biitschli). These two odd horns, the posterior apical horn and the anterior nasal horn, are usually different and divergent. In some genera a variable number of accessory radial horns is developed on the convex face of the cephalis. In many hornless genera the free apical horn is lost, but not unfrequently the columella is preserved which connects the caudal foot with that point of the cej)halis, in which formerly the apical horn was in serted. 1132 THE VOYAGE OF H.^NLS. CHALLENGEH. The three primary radial beams, corresponding to the three basal feet of Plectaniscus and Cortina, exhibit in the Cyrtoidea the greatest variety in form and size, and chiefly in their relation to the shell, the latter serving mainly for the distinction of genera. Orio-inally these three cortinar beams arise from the basal plate of the cephalis, the odd caudal foot appearing as a prolongation of the basal rod of that plate, and the paired pectoral feet as prolongations of its coracal rods (between the jugular and cardinal pores). The lattice-work of the thorax is developed usually between the three cortinar feet, more rarely inside or outside of them. Therefore the three beams appear commonly as three divergent ribs in the wall of the thorax, and continue over its basal mouth as three free terminal feet. "With the increasing length of the shell and the number of its joints the three radial ribs are also prolonged, and their free distal ends may be prominent at very different points, either as three lateral wings or as three terminal feet. These are either solid spines or lattice -plates, sometimes more or less ramified. The three radial apophyses are prevalent in the majority of the Cyrtoidea, which we call " Pilocyrtida " (or Cyrtoidea triradiata). Their number increases in the Astrocyrtida (or Cyrtoidea multiradiata). The most frequent cases of multiplication are here caused by the development of six or nine radial apophyses ; these may be enclosed ribs, or lateral wings, or terminal feet. In the sexradial Cyrtoidea there are three secondary or interradial apophyses interpolated between the three primary or perradial ; in the nine-radial Cyrtoidea, however, there are six adradial apophyses interpolated. A third and last great group is formed by the Corocyrtida or Cyrtoidea eradiata. These exhibit no radial apophyses, neither enclosed ribs, nor free lateral wings, nor terminal feet. But in a great number of them internal traces of an original triradiate structure are visible, mainly in the cortinar septum between cephalis and thorax ; this often exhibits three or four, and sometimes six cortinar or collar pores, of the same typical shape as in the triradial Spyroidea. Sometimes even an internal columella with three radial branches is preserved, as in Axocorys. It is therefore very probable that a great part of these Cyrtoidea eradiata (if not all) may be derived from triradiate or multiradiate ancestral forms, by reduction and loss of the radial apophyses. In another part of this group, mainly in the Monocyrtida eradiata (Cyrtocalpida) it is possible, or even probable, that their eradiate shell has originated independently from Nassellida, and that they have no true relation to radial Cyrtoidea. The Central Capsule of the Cy r toide a, first observed by J. Mliller (1858), and more fully described in my Monograph (1862), was very accurately examined by Richard Hertwig (1879). His observations were confirmed by numerous new forms, which I was able to examine in well-preserved preparations of the Challenger. The central capsule, according to these, exhibits the same typical shape, which is characteristic of all MoisroPYLEA (with porochora and podoconus), and may be derived with the latter from the common ancestral forms, Cystidmm and Nassella ( = the skeletonless Nassellida). In REPORT ON THE RADIOLARTA. 1133 the majority, however, of Cyrtoidea, the capsule develops on its basal face a number of depending lobes, as were also found in some Spyroidea (and probably also B 0 1 r y o d e a). lu this respect we may distinguish two main forms of the capsule in the C y r t e 1 1 a r i a, viz., the primary simple, not lobate form, and the secondary lobate form. The central capsule is originally always enclosed in the cephalis, and has there a simple, subspherical, ellipsoidal or ovate form. As soon as their growth increases, and the enclosing cephalis becomes too narrow, it sends out prolongations in the form of basal lobes, which depend from its base, and proceed through the pores of the basal lattice of the cephalis, or the cortinar pores. In the great majority of Cyrtoidea in which the capsule was observed, either three or four such lobes were seen (already described by J. Mliller). Of course this number depends upon the number of cortinar pores, which is either three or four ; therefore in the Cyrtoidea with three pores in the cortinar plate, we find three lobes of the central capsule (an odd posterior and two paired anterior) ; in the Cyrtoidea, however, with four pores in the cortinar plate (the majority) we find four lobes of the central capsule (two smaller anterior jugular and two larger posterior cardinal lobes). Usually each lobe is ovate or pear-shaped and encloses a large oil-globule, and often also an apophysis of the cell- nucleus. Section 1. MONOCYETIDA, Haeckel, 1862, Monogr. d. Eadiol, pp. 280, 281. Definition. — Cyrtoidea monothalamia, with simple, not jointed shell (or cephalis), without transverse constrictions. Synopsis of the three Families and six Subfamilies of Monocyrtida. \ Mouth open, . . . . .1. Archipilida. FamUy LIX. Tripocalpida. Three radial apophyses. Family LX. Phsenocalpida. Xumerous radial apophyses. Family LXI. Cyrtocalpida. Xo radial apophyses. ) Mouth closed, ) ^louth open, j Mouth closed, \ Mouth open, ) ]\Iouth closed, 2. Archiperida. 3. Archiphormida. 4. Archiphsenida. 5. Archicorida. 6. Archicapsida. Family LIX. Tripocalpida, n. fam. Archipilida et Archiperida, Haeckel, 1881, Prodromus, pp. 427, 429. Definition. — Monocyrtida triradiata. (Cyrtoidea with a simple, not jointed shell, representing a simple cephalis, with three radial apophyses.) 1134 THE VOYAGE OF H.M.S. CHALLENGER. The family Tripocalpida, composed of the Archipilida and Archiperida of mj- Prodromus, comprises those Cyrtoidea in which the hittice-shell is quite simple, without transverse constriction, and bears three radial apophyses. The two subfamilies differ in the shape of the basal mouth, which in the Archipilida is a simple wide opening, in the Archiperida closed by a lattice-plate ; the former are here divided into eight, the latter into seven different genera. Only three species of this family were hitherto described, all three belonging to the Archipilida, viz., (l) Tripocalpis galea (fossil in Barbados, figured by Ehrenberg, 1875, as Halicalyiitra galea), (2) Tripodisciuin campanula (fossil in Sicily, figured by Stohr, 1880, as Carpocanium) ; and (3) Tridictyopus elegans, of which Eichard Hertwig gave an excellent description in 1879, with an accurate figure of the central capsule. All tlie other species of the family (seventy) are new. The shell in the majority of Tripocalpida is ovate or campanulate, sometimes conical or three-sided pyramidal. Three radial apophyses are constantly distinct, either three lateral wings or three terminal feet ; these are usually solid spines, rarely lattice-plates. The top of the shell usually bears an apical horn, rarely two or more horns ; often the horn is wanting. The lattice-work of the shell is very various in the different species, and often of a remarkable structure (PI. 51, figs. 6-8 ; PI. 98, figs. 4-8). The cavity of the shell is in all Archipilida, and in a part of the Archiperida (Peridium, Archi^^era, Archibursa) quite simple. In the other part of the Archiperida, however, constituting the peculiar group of Euscenida (genera 504-507), a vertical columella arises in the centre of the basal plate, and is prolonged upwards in the apical horn ; this columella is either simple [Euscenium, Archiscenium) or branched {Cladoscenium, Pteroscenium) ; in the latter case the ascending branches are disposed in triradiate verticils and are inserted on the inner face of the shell (compare PI. 53, figs. 11-16, and PI. 98, figs. 1-4). The jshylogenetic origin of the Tripocalpida may be very divergent, and their morpho- logical affinity to the other Nassellaria is a very complicated problem. The Euscenida (genera 504-507) may be derived directly from the Plagonida {Plagoniscus) or Plectanida (Plectaniscus). The Archibursida (genera 508-510) however, manifest a closer aflinity to the Tripospyrida, and may be derived from them by reduction of the sagittal ring and constriction. In these two groups of Archiperida the shell may be regarded as a true cephalis. In the Archipilida, however, wliere the shell has a wide basal opening and the three radial ribs arise originally from the base of the apical horn, the shell itself may correspond to the thorax of the DicjTtida, and may be derived from these by loss of the cephalis. This is the more probable, as sometimes a small remnant of the reduced cephalis is preserved (PI. 98, fig. 8). None of these difficult questions can be answered until a much closer morphological knowledge of the Tripocalpida is acquired. EEPOET ON THE RADIOLARIA. 1135 I. Subfamily Archipilida. Basal mouth of the - shell a simple wide opening. II. Subfamily Archiperida. Basal mouth of the shell closed by a lattice-plate. Synopsis of the Genera of Tripocalpida Three terminal feet. Shell with three lateral ribs or wiiiys, with or without ter- minal feet. Shell without lateral ribs or wings but with three terminal feet. Shell in its axis with a free (simple or branched) in- ternal columella, prolonged into an apical horn. ( Apex with a horn, . ( No apical horn. Six to nine or more I -kj -it, , ■ , X i. !■ No apical horn, terminal feet. I ^ No terminal feet. Apex with a horn, No apical horn, Feet simple or ] Apex with a horn, . branched, not lat^ ticed. Feet latticed. Shell with three free feet, without lateral lattice- wings. Shell with three lateral lattice- wings, connecting the three feet with the horn. Shell with simple cavity, without free columella. Three free basal feet. No apical horn. Apex with a horn, . Columella simple, . Columella branched, Columella simple, . Columellabranched, One apical horn. Two or more horns. No apical horn. 496. Tripoealpis. 497. Tripodoniiim. 498. Tripterocalpis. 499. Trissopilium. 500. ArcMpilium. 501. Tripilidium. 502. Tripodiseium. 503. Tridictyopus. 504. Euscenium. 505. Cladoseenium. 506. Archiscenium. 507. Pteroseenium. 508. Peridium. 509. Archipera. 510. Archiburm. Subfomil)" 1. Aechipilida, Haeckel, 1881, Prodromus, p. 427. Definition. — T r i p o c a 1 p i d a with the basal mouth of the shell open (vel Mono- cyrtida trii-adiata aperta). Genus 496. Tripocalpis,^ Haeckel, 1881, Prodromus, p. 428. Definition. — A r c h i p i 1 i d a (vel Monocyrtida triradiata aperta) with three lateral ribs prolonged into three terminal feet. Apex with a horn. The genus Tripocalpis opens the series of Archipilida, or of those Monocyrtida in which the monothalamous shell exhibits a distinct triradial structure, and a simple open mouth, without cortinar lattice. Tripocalpis is probably the most primordial of the Archipilida, and has three lateral ribs, which are prolonged into three free terminal I Tripocalpis = \]td. with three feet ; tjiVoi/;, x«>nr/V. 1136 THE VOYAGE OF H.M.S. CHALLENGER. feet, and connected in the apex of the pyramidal or campanulate shell with the apical horn. It may probably be derived from Dictyo2')liimus by loss of the cephalis. The central capsule is simple, spherical, or ellipsoidal. 1. Tripocalpis plectaniscus, n. sp. Shell three-sided pyramidal, smooth, about as long as broad, with irregular polygonal pores and thin bars. Apical horn stout, three-sided pyramidal, about as long as the shell. From the three edges of its base arise three prominent straight radial ribs, which are prolonged into three large divergent feet, of equal size and tlie same form as the horn. Dimensions. — Shell O'l diameter, horn and feet 012. Hahitat. — Tropical Pacific (Pliilippine Sea), Station 206, depth 2100 fathoms. 2. Tripocaljns galea, Haeckel. Haliealyptra galea, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 74, Taf. ii. iig. 10. Shell campanulate, rough, about as long as broad, with irregular roundish pores and thick bars. Apical horn stout, three-sided pyramidal, scarcely one-fourth as long as the shell. Beyond its base there arise three prominent, shghtly curved lateral ribs, which are prolonged into three pyramidal, slightly divergent stout feet, somewhat shorter than the shell. Dimensions. — Shell 0-08 to 0-09 diameter, horn 0-02, feet 0-07. Habitat. — Fossil in Barbados. 3. Tripocalpis tricostata, n. sp. Shell ovate campanulate, one and a half times as long as broad, with regular circular pores, disposed in alternate longitudinal rows. Apical horn three-sided pyramidal, stout, half as long as the shell. In the middle of the shell there arise three wing-like lateral ribs, which are prolonged into three broad, slightly curved, divergent terminal feet. Dimensions. — Shell 012 long, 0-08 broad, horn and feet O'OG to O'OS. Habitat. — Fossil in Barbados. 4. Tripocalpis triserrata, n. sp. (PL 51, fig. 6). SheU ovate, nearly twice as long as broad. The three sides of the shell, between the three large ribs, are provided each with nine dehcate parallel, longitudinal, shghtly curved ribs, alternating with ten longitudinal rows of regular circular pores about as broad as the bars. Apical horn short and broad, three-sided pyramidal ; from the three edges of its base there arise three wing-like serrate main ribs, which are prolonged into three short pyramidal terminal feet. Dimensions. — Shell 012 long, 0'07 broad, horn and feet 01)1. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. REPORT ON THE EADIOLARIA. 1137 5. Tripocalpis cortinaris, n. sp. (PI. 97, fig. 3). Shell liemispherical, one and a half times as broad as loug, with regular, eireular, hexagonally framed pores. Apical horu stout, three-sided pyramidal, with three serrate edges. From the base of the latter arise three strongly dentate and curved lateral ribs, with recurved teeth, and these are prolonged into the serrate convex edge of the three basal feet, which are crescentic and twice as long as the shell. Dimensions. — Shell 0"07 long, O'l broad; horn 0'06 long, feet 014 long. Hahitat. — Indian Ocean, Cocos Islands (Kabbe), surface. Genus 497. Tripodonhim} Haeckel, 1881, Prodromus, p. 428. Definition. — Arc li ip il i d a (vel Monocyitida ti-iradiata aperta) with three lateral ribs prolonged into three terminal feet. Apex without horn. The genus Tripodonium differs from the preceding Tripocalpis, its prol^aljle ancestral form, only in the loss of the apical horn (already very small in some forms of the latter). It Ijears therefore to the latter the same relation that Seihojnlium does to DictyoiMmus. 1. Tripodonium campamdatum, n. sp. Shell campanulate, somewhat broader than high, with regular circular pores, twice as broad as the bars. Three broad lateral wings, lamellar, triangular, are prolonged over the peristome into three short triangular lamellar feet, one-fourth as long as the shell. Dimensions. — Shell 0-08 long, 0-09 broad; feet 0-02 long. Hahitat. — Central Pacific, Station 272, depth 2600 fathoms. 2. Tripodonium ovatum, n. sp. Shell ovate, one and one-thuxl times as long as broad, with numerous and small circular pores, scarcely as broad as the bars. Three prominent longitudinal ribs, arising in the lower half of the shell-wall, are prolonged into three divergent conical curved feet, about half as long as the shell. Dirnensions. — Shell 012 long, 0'09 broad ; feet 0'06 long. Hahitat. — Centi-al Pacific, Station 266, depth 2750 fathoms. Genus 498. Trijyterocaljns,'^ Haeckel, 1881, Prodromus, p. 428. Definition. — Archipilida (vel Monocyrtida triradiata aperta) with three lateral wings and a peristomial corona of numerous terminal feet. Shell ovate, witli constricted mouth, without apical horn. 1 Tri2Jodonium = ahtW with three feet. - Tripterocalpis = '[Jni with three wiugs ; tjiVtsjoj, xaXTr/f. (ZOOL. CHALL. EXP. — PART XL. 188C.) El' 143 1138 THE VOYAGE OF H.M.S. CHALLENGER. The genus Tripterocalpis is distinguished from the other Archipilida by the remark- able combination of three lateral \\4ngs and of numerous (six to nine or more) terminal feet. It may be derived directly from the preceding Tripodocalpis by multiplication of the terminal feet. These are sometimes obliquely directed. The central capsule is ellipsoidal or ovate, and fills up the greater part of the shell. 1. Tripterocalpis phylloptera, n. sp. (PL 51, fig. 1). Shell sleuder, ovate, nearly twice as long as broad. Pores circular, of difterent sizes and at unequal distances. Along the lower half of the shell there arise three broad triangular lamellar wings. Peristome with twelve conical, nearly jjarallel and vertical feet, about one-sixth as long as the shell. Dimeimans. — Shell 0'2 long. 012 broad; wings O'l long, feet 0'03 long. HaMtat. — Central Pacific, Station 271, depth 2425 fathoms. 2. Tripterocalpis conoptera, n. sp. (PI. 51, fig. 2). Shell ovate, nearly as broad as long. Pores regular, circular, quincimcial, twice as broad as the bars. In the middle of the shell there arise three conical, smooth, divergent wings, about half as long as the shell. Peristome with six short triangular, obUque, convergent feet. Dimensions. — Shell 016 long, 014 broad ; wings 0'09 long ; feet 002 long. Habitat — Central Pacific, Station 272, depth 2600 fathoms. 3. Tripterocalpis ogmoptera, n. sp. (PL 51, figs. 3—5). Shell ovate, nearly as broad as long. Pores small and numerous, circular or roundish, partly confluent, double-contoured (fig. 4). In the middle of the shell there arise three very large conical divergent wings, which are longitudinally striped and longer than half the shell. Peristome with lune short triangular, oblique, convergent feet. Divunsions. — Shell 018 long, 016 broad ; wings 012 long, feet 0"02 long. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 499. Trissopilium,^ Haeckel, 1881, Prodromus, p. 427. Definition. — A r c h i p i 1 i d a (vel Monocyrtida triradiata aperta) with three lateral ribs or wings. Mouth smooth, without terminal feet. Apex with a horn. The genus Trissojnlium and the following nearly allied Archipilium differ from the i)ther Ai'chipilida in the absence of terminal feet, the peristome being quite simple, and truncate. But there are three lateral wings, arising either from the apex or from the lateral sides of the monothalamous shell. Trissopilium may perhaps be derived from Lithomelissa by reduction of the cephalis. ' Trissopilium = SmuW hat witli three winga ; Tf/ujof, r^i'htov. TtEPORT ON THE EAUIOLARIA. 1139 1. T)-iSsopih')im (etraplecta, n. sp. Shell iu the upper half three-sided pyramidal, in the lower half inversely hemispherical, of equal length and breadth. Pores irregular, roundish, in the upper half larger. From the apex there diverge four equal, straight and stout, three-sided pyramidal spmes, one of which is vertically ascending (the horn), the three others oblitiuely descending (the wings). The distal half of the latter is free, whilst the proximal half forms three ribs, enclosed in the shell-wall. Mouth constricted, half as broad as the shell. Dimensions. — Shell 0"08 long and broad, horn and wings 0"1 long. EaMtat. — Central Pacific, Station 268, depth 2900 fathoms. 2. Trissopilium lithomditit;a, u. sp. Shell ovate, one and one-third times as long as broad. Pores circular, of different sizes, small and numerous. Apical horn very large, straight, cylindrical, vertical, longer than the shell. Three lateral wings shorter, arising from the middle of the shell, conical, curved, divergent. Mouth truncate, two-thirds as broad as the shell. Dimemions. — Shell Oil long, 008 broad; horn OlS long, wings 0-09 long. Habitat. — Central Pacific, Station 2*71, depth 2425 fathoms. Genus 500. Archipilium,^ Haeckel, 1881, Prodromus, p. 427. Definition. — A r c h i p i li d a (vel Monocj^-tida triradiata aperta) with three lateral ribs or wings. Mouth truncate, without terminal feet. Apex without horn. The genus Archiinlium difi'ers from the nearly allied Trissoptilium, its probal)le ancestral form, in the absence of the apical horn. The three lateral wings of the ovate shell are stout spines. It may also be derived from the similar Scthopilivm by reduc- tion and loss of the cephalis. 1. Archipilium orthopterum, n. sjj. (PI. 98, fig. 7). ' Shell ovate, smooth, nearly cylindrical, scarcely broader than the truncate, widely open mouth. Pores numerous, irregular, roundish, of very different sizes. Three lateral wings arising from the middle zone, twice as long as the shell, straight, divergent, stout, cylindrical, longitudinally striped. Dimensions. — Shell O'OS long, O'OG broad; wings 015 long. Habitat. — Central Pacific, Station 272, depth 2(300 fathoms. 2. Archipilium sigmoptenim, n. sp. Shell ovate, smooth, nearly campanulate, of equal length and breadth, one and one-third times as broad as the truncate, sliglitly constricted mouth. Pores scarce, irregularly formed and ' Arehipiliuvi = Vi'uuoTdhAl hat ; koy^ixChmy. 1140 THE VOYAGE OF H.M.S. CHALLENGER. scattered, of very different sizes. Three lateral wings, stout, prismatic, about as long as the shell widely divergent and S-shaped, curved. Dimensions. — Shell 0-08 diameter, wings 0"08 long. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 3. Archipilium cyrtopterum, n. sp. Shell ovate, rough, twice as broad as the constricted mouth. I'ores small and numerous, subregular, circular, smaller than the bars. Three lateral wings cylindrical, crescentic, in the upper half divergent, in the lower convergent, one and one-half times as long as the shell. Dime7isions. — Shell 0-09 long, 0-07 broad ; wings 014 long. Hahitat. — Central Pacific, Station 265, depth 2900 fathoms. Genus 501. Tripilidium,^ Haeckel, 1881, Prodromus, j)- 428. Definition. — A r c h i p i 1 i d a (vel Monocyrtida triradiata aperta) without lateral ribs, with three simple or branched terminal feet and an apical horn. The genus Tripilidium differs from Tripodonium in the absence of the three lateral ribs, and may be derived either from this ancestral form, or directly from Tripospyris (by loss of the sagittal ring and constriction); perhaps also from Lychno- canimn (by reduction of the cephalis). We distinguish as two subgenera Tristylocory.^ (with simple feet) and Tripodocorys (with branched feet). Subgenus 1. Tristylocorys, Haeckel. Definition. — Feet simple, not branched, 1. Tripilidium cortina, n. sp. Shell campanulate, rough, about as long as broad. Pores suliregular, circular, larger in the middle zone, twice to three times as broad as the bars. Mouth constricted, half as broad as the shell. Apical horn straight and stout, three-sided pyramidal, about as long as the shell. Three feet divergent, slightly S-shaped, curved, somewhat longer than the shell. Dimensions. — Shell O'l diameter, horn 0'09 long, feet 0"13 long. Hahitat. — Central Pacific, Station 272, depth 2600 fathom.s. 2. Tripilidium Jiemispluericum, n. sp. Shell hemispherical, smooth, nearly twice as broad as hmg. Pores large, with thin bars, irregular, roundish, of very different sizes. Mouth wide open. Apical horn conical, half as long as ' 7'ri/. REPOKT ON THE RADIOLARIA. 1141 the sliell. Three feet slender cylindrical, widely divergent, curved, nearly twice as long as the shell. I)ime7isiotis. — Sliell 0-08 long, 0'14 broad; horn 0"05 long, feet 015 long. Habitat. — South Pacific, Station 298, depth 2225 fathoms. 3. Tripilidimn lychnocanium, u. sp. Shell hemispherical, thorny, one and a half times as broad as long. Pores regular, circular, hexagonally fi-anied, as broad as the bars. Mouth slightly constricted. Apical horn stout and short, three-sided pyramidal. Three feet cylindrical, straight, divergent, twice to three times as long as the shell. (Similar to Lychnocanium favosum, PI. 61, fig. 6, perhaps derived fi'om it by reduction of the cephalis.) Dimensions. — Shell 0-08 long, 012 broad ; horn 0-02 long, feet 0'2 long. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 4. Tripilidmm ovatum, n. .sp. Shell ovate, smooth, one and a half times as long as broad. Pores regidar, circular, as broad a? the bars. Mouth constricted, half as broad as the shell. Horn short, conical. Three feet conical, cui-ved, convergent, scarcely one-third as long as the shell. Dimensions. — Shell 0'15 long. Oil broad; horn 0'02 long, feet 0'04 long. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 5. Tripilidium clavatum, n. sp. Shell nearly spherical, tuberculate, a little broader than long. Pores regidar, circular, as Ijroad as the bars. Mouth constricted, half as broad as the shell. Apical feet and the three divergent feet of equal size and similar form, about as long as the shell, straight, in the basal half smooth, cylindrical, in the distal half club-shaped, dimpled. (Very similar to Triiwspyris conifcra and Tripo- spyris eucolpos, PI. 84, figs. 7 and 4 ; but the spherical shell exhibits no trace of sagittal ring or constriction, and the simple shell-cavity has a wide open mouth, and is not closed by a liasal plate.) Dimensions. — Shell 01 diameter, horn and feet 0'08 to 0"09 long. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. (3. Tripilidium costatum, n. sp. (PI. 98, figs. 8, Sa, 8h). Shell ovate, spinulate and costate, nearly twice as broad as long. Surface with fifteen to twenty prominent longitudinal ribs, which are convergent towards each pole and elegantly denticulate. The deep furrows between them are divided by delicate, parallel, transverse ribs into numerous short and broad dimples (thirty to forty in each furrow); each dimple contains a small pore, like a transverse 1142 THE VOYAGE OF H.M.S. CHALLENGER. fissure. The apex beai's a short and stout, three-sided pyramidal horn, the hollow base of which is closed by a small cortinar septum with three collar pores (fig. 8h). This seems to indicate a rudimentary cephalis and the derivation of this species from Lijchnocanium (PL 61). Peristome constricted, only one-fourth as broad as the shell, with three short, conical, nearly vertical feet. The central capsule (fig. 8a) in the specimen examined was well preserved, hemispherical, not lobate, and filled up the upper half of the shell-cavity (beyond the rudiment of the cortinar septum). Dimensions. — SheU 0'2 long, 0"12 broad ; horn O'Ol long, feet 0'fl2 long. Habitat. — Tropical Atlantic, Station .348, deptli 2450 fathoms. 7. Tripilidium donyatum, n. sp. SheU elongate, smooth, nearly cylindrical, in the upper third conical. Pores small and numerous, regular, circular, half as broad as the bars, disposed in alrout thirty longitudinal alternatmg rows. Peristome scarcely constricted. The apical horn and the three parallel feet are of equal size and similar form, straight, conical, one-sixth as long as the shell. Dimensions. — Shell 0'12 long, 0"06 broad ; horn and feet 002 long. Habitat. — Fossil in Barbados. Subgenus 2. Tripodocorys, Haeckel, 1881, Prodromus, p. 428. Definition. — Feet forked or branched. 8. Tripilidium dichopodium, n. sp. Shell hemispherical, nearly twice as broad as long, smooth. Pores irregular, roundisli, twice to four times as broad as the bars. Mouth wide open. Apical horn spindle-shaped, half as long as the shell. Three feet cylindrical, nearly straight and parallel, as long as the shell, forked at the distal end. (Exhibits an external similarity to Triposjjyris scmantis, PI. 84, fig. 2, but has no trace of sagittal ring and constriction, and the simple shell-cavity has a wide open mouth.) Dimensions. — 0'06 long, 01 broad ; horn 0"03 long, feet 0'07 long. Habitat. — North Pacific, Station 241, depth 2300 fathoms. 9. Tripilidinm cladoptodium, n. s]:). SheU campauulate, rough, about as long as broad. I'ores subregular, circular, as broad as tlie bars. Mouth slightly constricted. Apical horn and three divergent feet of nearly equal size and form, three-sided prismatic, straight and stout, irregularly dentate and bi'anched, somewhat longer than the shell. Dimensions. — Shell O'OS diameter; horn and feet 0"1 to 012 long. Habitat. — Central Pacific, Station 205, deptli 2900 fathoms. REPOET ON THE RADIOLARIA. 1143 Genus 502. Tripodiscium,^ Haeckel, 1881, Prodromus, p. 428. Dcjinition. — Archipilida (vel Mouocyrtida triradiata aperta) without lateral ribs aud apical horn, with three simple or branched terminal feet. The genus Tripodiscium may he derived either from the preceding Tripilidium by loss of the apical horn, or from the nearly related Tristylospyi'is by loss of the sagittal ring and constriction. Some forms of the latter genus can scarcely be distinguished from similar species of the former. Subgenus 1. Tripodiscinus, Haeckel. Definition. — Feet simple, not Ijranched nor forked. 1. Tripodiscium tristylospyris, n. sp. Shell subspherical, with regular, circular pores, twice as broad as tlie bars. Mouth constricted, half as broad as the shell, with three short spindle-shaped feet, which are nearly parallel and vertical, lialf as long as the shell. (Similar to Tristylospyris scaphipcs, PI. 84, fig. 13, but without sagittal rmg and constriction.) Dimensions. — Shell 0'08 long, 0'07 broad ; feet 004 long. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 2. Tripodiscium ovatmn, n. sp. Shell ovate, rough, nearly as broad as long. Pores regular circular, double-contoured, twice as broad as the bars. Mouth constricted, one-third as broad as the shell, with three convergent short triangular feet. Dimrnsimis. — Shell O'l long, 009 broad ; feet 0'02 long. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 3. Tripodiscium clavatum, n. sp. Shell ovate, smooth, one and a half times as long as broad. Pores irregular roundish, of different sizes. Mouth constricted, two-thirds as broad as the shell, with three divergent, straight club-shaped feet, nearly as long as the shell. Dimensions. — Shell 012 long, O'OS broad ; feet Ol long. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. ' rry)odt«m(m= Shell mtli three .small feet ; Tf/a, TtMianK,). 1144 THE VOYAGE OF H.M.S. CHALLENGER. 4. Tripodischim campanula, Haeckel. Carpocanium campanula, Stblu-, 1880, Palaeontogr., vol. xxvi. p. 9G, Taf. iii. fig. 9. Shell campanulate or subspherical, smooth, about as long as broad. Pores small, regular circular, as broad as the bars. Mouth constricted, about half as broad as the shell, with three sliort conical descending feet. Dimensimis. — Shell 0-06 long, 0-05 broad ; feet 0-02 long. Habitat. — North Pacific, Station 244, depth 2900 fathoms ; fossil in Sicily. Subgenus 2. Tripodiscidus, Haeckel. Definition. — Feet branched or forked. 5. Tiipodiscitim furcatum, n. sp. Shell ovate, rough, nearly as broad as long. Pores subregular, circular, twice as Ijroad as the bars. Mouth constricted, two-thirds as broad as the shell, with three divergent parallel and \'ertical feet, which are as long as the shell, and forked at the tUstal end. Dimensio7is. — Shell 0'09 long, 0'08 broad ; feet 0'07 long. Habitat. — Tropical Atlantic, Station 338, depth 1990 fathoms. 6. Tripodiscium ramosum, n. sp. Shell ovate, tuberculate, nearly as Inroad as long. I'ores irregular, roundish, of very different sizes. Mouth constricted, half as broad as the shell, with three large, divergent, irregularly branched feet, nearly twice as long as the shell. (Similar to Tristylospyris ramosa, V\. 52, fig. 23, but without sagittal ring and constriction.) Bwnensions. — Shell 0*07 long, 0'06 broad ; feet 015 long. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 7. Tripodiscium sphcerocephalum, n. sp. (PL 52, fig. 21). Shell subspherical, rough, with circular pores of difierent sizes. Mouth constricted, circular, simple, two-thirds as broad as the shell, with three large divergent feet, which are three-sided prismatic, irregularly branched, and twice as long as the shell. Biimnsions. — Shell 0'07 long, O-QB broad ; feet 0-12 long. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. EEPORT ON THE RADIOLAEIA. 1145 Genus 503. Tridictyojnis,'^ Haeckel, 1881, Prodromus, p. 428. Definition. — A r c h i p i 1 i d a (vel Monocyrtida trii-adiata aperta) with three latticed terminal feet. Shell ovate or subconical, with an apical horn. The genus Tridictyojyus diflfers from the nearly allied Trijnlidium in the possession of three large fenestrated shovel-shaped feet, forming direct prolongations of the large conical shell. The lattice work exhibits a peculiar elegant structure recurring in the similar, perhaps nearly related, Cephalospyris (PI. 83, fig. 10; PI. 96, fig. 28). The central capsule is large, ellipsoidal or ovate, and fills up the greater part of the shell cavity (compare R. Hertwig, 1879, loc. cit., p. 75). 1. Tridictyopus vatillum, n. sp. (PL 51, fig. 8). Shell campamilate, about as long as broad (excluding horn and feet). Pores irregular, polygonal, in the middle part more regular, triangular. Horn short and stout, three-sided pyramidal. Three feet large, triangular, shovel-shaped, about half as long as the shell. DimensioTis. — Shell 0'14 long, 0"15 broad. Hahitat. — South Atlantic, Station 332, depth 2200 fathoms. 2. Tridictyojyus conidus, n. sp. (PI. 51, fig. 7). Shell campanulate conical, about one and a half times as long as broad (excluding horn and feet). Pores mostly triangular, disposed in subregular hexagonal figures, which are separated by bands of smaller irregular polygonal pores. Horn short and stout, three-sided pyramidal. Three feet triangular shovel-shapeil, convergent, about one-sixth as long as the shell. Dimensions. — SheU O'o long, 0'2 broad ; horn 0'04 long, feet 005 long. Habitat. — Equatorial Atlantic, Station 347, depth 2250 fathoms. 3. Tridictyopus elegans, R. Hertwig. Trii:Udijo2ms elegans, E. Hertwig, 1879, Organismus d. Radiol., p. 75, Taf. vii. fig. 3, 3a, 3&. SheU slender, conical, campanulate, about twice as long as bioad (excluding horn and feet). Most pores subregular triangular, with some irregular polygonal ones intermingled. The horn in the two observed specimens was broken off, together with the conical apex of the shell. Three feet triangular shovel-shaped, about one-sixth as long as the shell Dinuiisions. — SheU 0'3 long, 0'15 broad ; feet 0'05 long. Habitat. — Mediterranean (Messina), E. Hertwig, surface. ' Tridictyopus — Shell with three lattice-feet ; Tg/«, o/kti/o;/, xoii;. (ZOOL. CHAI.L, EXP. PART XL. — 188G.) El' 144 1146 THE VOYAGE OF H.M.S. CHALLENGER. Subfamily 2. Archiperida, Haeckel, 1881, p. 429. Definition. — Tr ip o c al pid a with the basal mouth of the shell fenestrated {vel Monocyrtida triradiata clausa). Genus 504. Euscenixim^ n. gen. Definition. — A r c h i p e r i d a (vel Monocyrtida triradiata clausa) with a free simple internal columella, prolonged into an apical horn. Three basal feet free, without lateral wings. The genus Euscenium and the three following nearly allied genera form together the remarkable small group of Euscenida, probably one of the oldest and most primitive of all C y r t o i d e a, and perhaps the common root of this suborder, arising directly from the P 1 e c t o i d e a. The simple skeleton is composed of four radial beams united in one point (the cortinar centrum). Three beams are directed downwards, and form three divergent basal feet ; the fourth beam is directed upwards and represents an apical horn ; its basal part is enclosed as " columella" in the cavity of the simple shell, the lattice-work of which connects the four spines (compare above, Plectaniscus, p. 924). In the genus Euscenium, the simplest of all, the columella is simple, and the three feet also simple, without wings. Subgenus 1. Euscenarium, Haeckel. Definition. — Three feet simple, not branched. 1. Euscenium plectaniscus (PI. 98, fig. 1). Shell three-sided pyramidal, thorny, about as long as broad, with three dentate edges. Frame- work very loose, with irregular polygonal meshes ; in the middle of each of the three triangular sides a horizontal band of denser network. Basal plate with three very large simple collar-holes. The apical horn and the three feet are three-sided pyramidal, about half as long as the columella, with three prominent irregularly dentate edges. The horn is straight, whilst the three feet are hook-shaped, its distal end being curved downwards and inwards. Dimensions. — Shell Oil long, 013 broad. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 2. Euscenium archicyrtis, n. sp. Shell three-sided pyramidal, smooth, nearly as long as broad, with three straight edges connected by irregular loose framework with polygonal meshes. Basal plate with three very large ' Euscenium = 'Nice small tent ; sJ uxni/zls. REPORT ON THE RADIOLARIA. 1147 simple collar-holes. The apical horn and the three feet are three-sided prismatic, smooth, about twice as long as the columella, straight and widely divergent. Bimcnsimis. — Shell 008 long, O^l broad. Habitat. — Tropical Pacific, Station 225, depth 4475 fathoms. 3. Euscenium hemisphoericum, n. sp. Shell hemispherical smooth, half as long as broad, with small and numerous subregular circular pores. Basal plate with three large triangular simple collar-holes. Horn slender, three-sided prismatic, twice as long as the columella. Feet very slendei", with three denticulate edges, widely divergent and curved lite the quadrant of a circle. I>imensio7is. — Shell 0'04 long, 0'06 broad. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 4. Euscenium tricolpiuin, n. sp. (PL 53, fig. 12). Archiscenium tricolpiwn, Haeckel, 1881, Prodromus et Atlas, loc. dt. Shell cap-shaped, nearly hemispherical, with three vaulted hemispherical bosoms between the three arches ascending from the feet to the horn. Network very irregular, with polygonal meshes, of different form and size. Basal plate with three large primary and some smaller irregular accessory collar-holes. Horn slender, straight, twice as long as the columella. Feet of the same length, slender, widely divergent, slightly curved. The three edges of the horn and the feet are elegantly denticulated. Dimensions. — Shell 0'04 long, 0-08 broad. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 5. Eusceniuvi triposjjyris, n. sp. (PI. 84, fig. 8). Tripospyris euscenium, Haeckel, 1881, Prodromus et Atlas. SheU nearly spherical, smooth, with numerous small circular pores. Basal plate also with numerous small pores. Horn and feet stout, three-sided prismatic, straight or slightly curved, about as long as the thin, somewhat curved columella. This species is closely aUied to Tripospyris. Dimensions. — Shell Oil to 0-12 diameter, horn and feet O'OS to 01 long. Habitat. — South Pacific, Station 298, depth 2225 fathoms. Subgenus 2. Euscenidium, Haeckel. Definition — Feet forked or branched. 6. Euscenium furcatum, n. sp. SheU campanulate, smooth, with numerous irregular roundish pores. Basal plate with nine pores (three larger central and six smaller distal). Horn club-shaped, half as long as the columella. 1148 THE VOYAGE OF H.M.S. CHALLENGER. Feet twice as long, cylindrical, parallel, vertical, forked at the distal end. (Similar to Tripos2')yris semantis, PI. 84, fig. 2, but without sagittal feet.) Dimensions. — Shell O-O? long, 0'06 broad; horn 0-04 long, feet 01 long. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 7. Euscenium quadratum, n. sp. Shell campanulate, smooth, with subregular square pores. Basal plate with three large pores. Horn and feet of the same size and shape, twice as long as the columella, three-sided prismatic, each with four or five verticils of lateral branches. (Similar to the cephalis of Clathrocorys murrayi, PI. 64, fig. 8, but with four free spines without connecting lattice-wings.) Dimensions. — Shell 0'06 long, 0'05 broad ; horn and feet 0"12 long. Habitat. — Central Pacific, Station 272, surface. 8. Euscenium ramosum, n. sp. Shell subspherical, rough, with small subregular circular pores. Basal plate with nine pores (three larger central and six smaller distal pores). Horn and feet of the same size and form, three to four times as long as the columella, three-sided prismatic, irregularly branched. Dimensions. — Shell 0'06 diameter, horn and feet 015 to 0'2 long.. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 505. Cladoscenium,^ Haeckel, 1881, Prodromus, p. 429. Definitiori. — A r c h i p e r i d a (vel Monocyrtida triradiata clausa) with a free branched internal columella, prolonged into an apical horn. Three basal feet free, without lateral wings. The genus Cladoscenium differs from the preceding Euscenium only in the ramifica- tion of the internal columella, which bears one or more verticils of three ascending lateral branches. The three branches of each verticil lie in the same equidistant meridian planes as the three basal feet, and are inserted with their distal ends on the inner surface of the simple lattice-shell. The three feet are also branched, but without vertical lattice-wings. Cladoscenium is perhaps closely allied to Clathrocorys. 1. Cladoscenium fulcratum., n. sp. Shell subspherical, smooth, with large irregular roundish pores. Basal plate with three large pores. Columella with a single verticil of three ascending lateral branches. Apical horn as long as the ' Cladoscenimn — '&raiAX tent with branched axis ; Khccios, ikyiuiov. REPORT ON THE RADIOLARIA. 1149 columella, simple, three-sided prismatic. Feet twice as long, widoly divergent, straight, prismatic, with some irregular hasal branches. Dimensions. — Shell O'OG diameter, horn 0'05 long, feet 01 long. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Cladoscenium ancoralum, n. sp. (PL 53, fig. 13). Shell campanulate, smooth, with irregular polygonal pores. Basal plate with six pores (two large cardinal, two smaller jugular and two still smaller cervical pores). Columella with a single verticil of three ascending lateral branches (by mistake not distinct in the figure). Apical horn and the three feet of the same form and size, slender, prismatic, twice to three times as long as the shell, straight, in the distal half with three slender recurved branches, anchor-shaped. Dimensions. — Shell O^OS long, 0-04 broad ; horn and feet 0"1 to 015 long. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 3. Cladoscenium gladiatutn, n. sp. Shell subspherical, with irregular polygonal pores. Basal plate with three large pores. Columella with two verticils of three ascending lateral branches. Apical horn as long as the columella, three-sided prismatic. Feet of the same form, twice as long, in the distal half with two opposite transverse branches, sword-shaped. DimcTisions. — Shell 0'05 long, 0"06 broad ; horn 0"04 long, feet 01 long. Habitat. — "Western Tropical Pacific, Station 225, depth 4475 fathoms. 4. Cladoscenium pinnatum, n. sp. Shell campanulate, with irregular polygonal pores. Basal plate with four pores (two major cardinal and two minor jugular). Columella with two verticils of three ascending lateral branches, and prolonged into a slender prismatic apical horn of twice the length, which bears four such verticils. Feet twice as long as the horn, pinnate, each with four or five pairs of opposite lateral branches, decreasing towards the thin dLstal end. Dimensions. — Shell 0'06 long, 0'05 broad ; horn 01 long, feet 0'2 long. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. 5. Cladoscenium veHicillatum, n. sp. Shell campanulate, with subregular square pores. Basal plate with nine pores (three larger central and six smaller distal). Columella with three verticils of three ascending lateral branches. Apical horn and the three basal feet of equal size and similar form, four to six times as long as the columella, three-sided prismatic, each with four to five verticils of three lateral branches, which are 1150 THE VOYAGE OF H.M.S. CHALLENGER. irregularly ramified and tapering towards the distal end. (Similar to Clathrocorys tcuscheri, PL 64, fig. 10, but with four free spines, without connecting lattice- wings.) Di7)iensions. — Shell 0-07 long, O'OG broad ; horn and feet 0-2 to 0-25 long. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 6. Cladoscenmm pectinatum, n. sp. (PL 98, fig. 2). Shell subspherical, with irregular roundish pores. Basal plate with three large holes. Columella with two verticils of three ascending lateral branches. Apical horn and the three feet of nearly the same size and form, three to four times as long as the columella, straight, three- sided prismatic, each with five to eight verticils of three simple lateral branches, tapering towards the distal end. Dimensions. — Shell 0-07 long, O'OS broad ; horn and feet 016 to 0-22 long. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. , Genus 506. Archiscenium,^ Haeckel, 1881, Prodromus, -p. 429. Definition. — A r c li i p e r i d a (vel Mouocyrtida triradiata clausa) with a free simple internal columella, prolonged into an apical horn. Three basal feet connected with the horn by three vertical lateral wings. The genus Archiscenium and the following nearly allied Pteroscenium are derived from the two preceding genera, from which they diifer in the development of three free vertical lateral lattice-wings ; these arise from the upper edge of the three basal feet and connect them with the three edges of the apical horn. The basal part of the latter, enclosed in the shell, forms an internal free columella, which in Archiscenium is simple, not branched. 1. Archiscenium quadrispinum, n. sp. (PL 53, fig. 11). Shell hemispherical, smooth, with a small number of large irregular polygonal meshes and thin bars. Basal lattice with three very large central meshes and six smaller peripheral meshes (two on the base of each foot). Apical horn and the three feet of equal size and similar form, slender, pyramidal, widely divergent, straight, as long as the shell-cUameter. Three lateral wings small, little prominent, each with two or three irregular meshes. Central capsule subspherical. Dimensions. — Shell 0"05 long, O'l broad. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 2. Archiscenium clathrocorys, n. sp. Shell campanulate, smooth, with numerous irregular square meshes. Basal lattice with three very large meshes. Apical horn and the three feet of equal size and similar form, three-sided prismatic, ' yl 7-c/n'scemMm = Primordial teut ; eci^xh ""■l"'''''- EEPORT ON THE RADIOLAEIA. 1151 widely divergent, straight, twice as long as the shell-diameter. Three lateral wings broad, each with a basal row of few very large irregular roundish meshes, and several distal rows of small square meshes. This species is very similar to Clathrocorys mttrrayi (PI. 64, fig. 8), but has no trace of thorax-wall. The latter species may be derived from the former by development of the thoracic lattice, which connects the three free feet. Dimensions. — Shell 0*05 long, 0'06 broad. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 3. Archiscenium tripterygiwm, n. sp. Shell hemispherical, smooth, with numerous irregular roundish meshes of very different sizes. Basal lattice with four large meshes, two major cardinal and two minor cardinal pores. Apical horn and the three feet of similar form and size, slender prismatic, three to four times as long as the shell ; the horn straight, the feet curved. Three lateral wings very delicate, with a basal row of few large irregular polygonal meshes, and several distal rows of similar small pores. Dimensions. — Shell 0'04 long, 0'05 broad. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 4. Archiscenium cyclopteruvi, n. sp. (PL 98, fig. 3). Shell hemispherical, with small irregular roundish pores. Basal lattice with four large meshes, two major cardinal and two minor jugular pores. Apical horn and the three feet of similar form and size, slender prismatic, straight, twice to four times as long as the sheU. Three lateral wings nearly semicircular, densely latticed, with the same pores as the shell, and smooth convex margin. Dimensions. — Shell 0'05 long, 0'06 broad. Habitat. — South Pacific, Station 295, depth 1500 fathoms. 5. Archiscenium callimitra, n. sp. Shell campanulate, with irregular polygonal pores. Basal lattice with nine meshes (three larger central and six smaller distal pores, as in Calliynitra carolotw, PL 63, fig. 8). Apical horn straight, prismatic, slender, conical, twice as long as the shell. Feet longer and more slender, slightly curved. Three lateral wings very broad, densely fenestrated, with irregular polygonal pores of the same shape as in the similar Callimitra carolotw (PI. 63, fig. 1). Dimensions. — Shell 0'05 long, 0'04 broad. Habitat. — ^Western Tropical Pacific, Station 225, depth 4475 fathoms. Genus 507. Pteroscenium} Haeckel, 1881, Prodromus, p. 429. Definition. — A r c li i p e r i d a (vel Monocyrtida triradiata clausa) with a free branched internal cohimella, prolonged into an apical horn. Three basal feet connected with the horn by three vertical lateral wings. 1 Pteroscenium = Small tent witli wings ; •jrri^oi/, hormis^ Elirenberg, 1847, Monatsber. d. k. preuss. *Akad. d. Wiss. Berlin, p. 54 (sensu mutato). Definition. — A r c h i p li o r m i d a (vel Monoeyrtida multiradiata aperta) with numerous radial ribs in the wall of the campanulate shell, prolonged into free terminal feet. Apex with a horn. The genus Hcdiphormis (with an ajiical horn) and the following Archipihormis (without a horn) comprise those Archiphormida in which the open mouth is more or less constricted and surrounded by a coronet of radial feet, as terminal prolongations of the radial ribs of its wall. The few forms, upon which Ehrenberg originally founded the genus Hali2)hormis, are partly not recognisable, partly belong to other genera. We therefore give here a new definition of the genus, as stated in my Prodromus, 1881, p. 428. ^ Haliphormis =Sea-ba,sket ; «7if, (fo^/iig. KEPORT ON THE RADIOLARIA. 1167 1. Haliphormis lagena, n. sp. (PI. 97, fig. 5) Shell bottle-shaped, twice as long as broad, tapering towards both ends, with nine longitudinal curved ribs. These are connected by irregular transverse beams, and the quadrangular meshes, so produced, are filled up by irregiilar, delicate, arachnoidal framework. The constricted mouth is half as broad as the middle part of tlie shell and surrounded by nine slender convergent feet, the free distal ends of the ribs. The apex bears a small knob with an oblique horn, perhaps the rudimentary cephalis of Sdhamphora or SdJwpi/ramis (?). DimensioTis. — Sliell 0"6 to 0"7 long, 0'3 to 0'4 broad. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 2. Haliphormis costata, n. sp. Shell campanulate, somewhat longer than broad, with twelve prominent longitudinal ribs, alternating with twelve rows of regular circular pores. Mouth constricted, half as broad as the shell, with twelve long triangular feet, formed by the free distal ends of the ribs. Apical horn short and stout, triangular pyramidal. Dimensions. — Shell 0'12 long, 01 broad ; mouth 0'07 long. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 518. Archiphormis,^ Haeckel, 1881, Prodromus, p. 428. Definition. — A rcliij)liormida (vel Monocyrtida multii-adiata aperta) with numerous radial ribs in the wall of the campanulate or urceolate shell, prolonged into free terminal feet. Apex without horn. The genus Archiphormis differs from the preceding Halijiliormis, its probable ancestral form, in the absence of the apical horn. The number of the longitudinal ribs, which are prolonged into terminal feet, is from six to nine or twelve or even more. 1. Archiphormis cancellata, Haeckel. (?) Halicaly]jtra cancellata, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 243. Shell cup-shaped or campanulate, with six prominent ribs, prolonged into six terminal triangular feet, one-third as long as the shell. Eiljs connected by five or six transverse horizontal rings ; meshes between them rounded squarish. (As Ehrenberg has given no figure of this species, its identity with the Challenger specimen is doubtful.) Dimensions. — Shell O'OS long, 0-06 broad ; mouth 0-04 broad. Habitat. — North Atlantic, Station 353, depth 2965 fathoms. ' .4 rcfeipAormw = Primordial-basket ; ajx'i P/wEJioni^j^is = Urceolate shell ; (paha, r.a.'Kirii. 1174 THE VOYAGE OF H.M.S. CHALLENGER. 2. PhcBnocaljns ocellata, Haeckel. Petalospyris ocellata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xxii. fig. 9. Shell subspherical, smooth, with irregular roundish pores, about as broad as the bars. Columella slightly curved aud excentric, prolonged into a slender conical horn of the same length. Six l^asal feet similar to the horn, slightly divergent. Dimensions. — Shell 0'06 long, 0'07 broad ; horn and feet 0'05 long. Habitat. — Fossil in Barbados. 3. Plumiocalpis carinata, Haeckel. Fefalonpi/ris carinafa, Ehrenberg, 187.5, Abhamll. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xxii. fig. 6. Shell campanulate, rough, with irregular roundish pores, smaller than the bars. Columella straight, central, prolonged into a stout conical horn of the same length. Nine basal feet slender, triangular, longer than the shell, nearly vertical, with a middle rib in the basal half. Dimensions.' — Shell 0'05 long, 0'06 broad ; horn 0'04 long, feet 0'08 long. Habitat. — -Fossil in Barbados. 4. Phcenocalpis Jlabellum, Haeckel. Petalospuris flahelluin, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. xxii. fig. 7. Shell campanulate smooth, with very small circular pores, half as broad as the bars. Columella straight, central, prolonged into a pyramidal horn of half the length. Twelve to fifteen basal feet lamellar, linear, twice to three times as long as the shell, parallel and vertical, pointed at the distal end. Dimensions. — Shell O'Oi long, 0'05 broad ; horn 0'02 long, feet O'l to 0'12 long. Habitat. — Fossil in Barbados. Genus 523. Phmiosceniutn,^ u. gen. Definition. — A rchiphaenida (vel Monocyrtida multiradiata clausa) with an internal axial branched columella, prolonged outside into an apical horn. The genus Phcenoscenium differs from the preceding Phcenocalpis in the branched columella, which is connected by three or six ascending branches with the inner wall of the shell. It bears therefore to the latter the same relation that Cladoscenium exhibits to Euscenium. The former genera may have been derived from the latter by inter- polation of new interradial feet between the three primary perradial feet. ' Pft.a7j.osc6m«TO = Tent-shaped shell ; ^ahx., cKnvio'j. REPORT ON THE RADIOLARIA. 1175 1. FJuvnoscenium hexapodium, n. sj). (PL 98, fig. 9). Shell campanulate, smootli, alwut as long as broad. Network delicate, with irregular polygonal pores and thiu bars. Colinnella with four to six ascending three-branched verticils, prolonged into the conical hollow apical horn (witli six to eight smaller verticils) wliich is about as long as tlie shell. Six basal feet curved, divergent, of the same lengtli, witli pinnate middle rod. Dimoisions. — Shell O'l long. Oil broad; horn and feet 0-08 to 0-09 long. Habitat. — Central Tacific, Station 271, depth 2425 fathoms. 2. PhcBnoscenium cladopodiinn, n. sp. Shell campanulate, conical, smooth, somewhat broader than long. Network with irregular roundish pores, about as broad as the bars. Columella with a single verticil of three ascending l)ranches. Horn pyramidal, stout, as long as the shell, with three dentate edges. Six feet divergent, slightly curved, very unequal ; three primary (or perradial) very large, longer than the shell, three-sided pyramidal, with three dentate edges ; three secondary (or interradial) much smaller, simple, shorter than the shell. Dimensions. — Shell 0'05 long, 0-06 broad ; horn and feet 0'04 to 0'07 long. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 3. PhcBnoscenium, 'polyiwdium, u. sp. Shell subspherical, about as long as broad, smooth. Network with regular circular pores, twice as broad as the bars. Columella with two verticils of three ascending branches, prolonged into a stout conical horn of twice the length. Twelve to fifteen conical curved divergent feet, about as long as the shell. The three primary feet are directly connected with the base of the columella. Dimensions.- — Shell 0-08 diameter, horn 015 long, feet 0'07 to 0-09 long. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. Genus 524. CalpoplicBna,'^ Haeckel, 1881, Prodromus, p. 429. JD-efinition. — A r c h iph ge n i da (vel Monocyrtida multiradiata clausa) with an apical horn and simple internal cavity of the shell, without axial columella. The genus Calioophcena and the following closely allied Archiphcena differ from the two preceding genera of Archijjhsenida in the simple shell cavity, which encloses no columella. They may be derived either from the preceding Phcenocaljns by loss of the columella, or directly from the Zygospyrida by reduction of the sagittal constriction and loss of the primary ring. Different subgenera may be distinguished in Calpophcena according either to the number of the feet or to their shape (being simple or branched). 1 Cal'po])hcEna=\]mo\a.te. shell; xcthTrii, (paha. 117(3 THE VOYAGE OF H.M.S. CHALLENGER. Subgenus 1. Acrocorona, Haeckel, 1881, Prodromus, p. 430. Definition. — Feet simple, not l)ranclied nor forked. 1. Calpophwna tetrarrhahda, n. sp. Shell subspherical, tuberculate, with subregular circular pores. Apical horn conical, about as long as the sheU. Basal plate with a regular cross of four equal cortinar pores, separated by four bars ; these are crossed in the sagittal and frontal diameter, and prolonged into four equal conical divergent feet, about as long as the shell. Dimensions. — Shell O'l diameter, horn and feet O'l to 0'12 long. Habitat. — South Pacific, Station 297, depth 1775 fathoms. 2. Calpophcena hexarrhabda, n. sp. (PL 53, figs. 17, 18). Shell subspherical, rough, with irregular roundish pores. Apical horn conical, shorter than the shell. Basal plate (fig. 18) with three pairs of triangular pores, two larger (cardinal) pores in the middle, two smaller (cervical) at the dorsal, and two intermediate (jugular) at the veutral side. The bars between them are prolonged into six equal cylindrical divergent feet, nearly as long as the shell, provided with a spiny knob at the end. Dimensions. — Shell 0'09 long, 0'08 broad ; horn and feet 0"0G to 0'08 long. Habitat. — Tropical Pacific, Station 224, depth 1850 fathoms. 3. CalpopjluBiia ennearrhahda, n. sp. Shell subspherical, spiny, with irregular, roundish pores. Apical horn cylindrical, longer than the shell. Basal i^late with nine collar pores, three larger central alternating with three pairs of smaller peripheral (like PL 87, fig. 2). Corona with nine slender cylindrical, slightly curved, divergent feet, somewhat longer than the shell. Dimensions. — Shell Oil long, O'l broad ; horn and feet 012 to 015 long. Habitat. — North Pacific, Station 241, depth 2300 fathoms. 4. Ccdp)ophcena ennea2)hyUa, n. sp. Shell ovate, smooth, with regular circular pores. Apical horn pyramidal, half as long as the shell. (Basal plate with four cortinar pores?) Corona with nine broad, lamellar, truncate, vertical feet, about as long as the horn. Dimensions. — Shell 012 long, 0'09 broad; horn and feet 0'06 long. Habitat. — Central Pacific, Station 271, surface. REPOKT ON THE EADIOLARIA. 1177 5. Calpophcena jxitalosj^i/ris, ii. sp. Shell campanulate, tuberculate, with irregular, roundish pores. Apical horn conical, shorter than tlie shell. (Basal plate with nine pores ?) Corona with twelve to twenty broad, lamellar, truncate, vertical feet, of different sizes, somewhat irregular. Dimensions. — Sliell 0'08 long, 0'09 broad; horn and feet 0'07 to 0-12 long. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. Siil)o;enus 2. Cladocorona, Haeckel, 1881, Prodromus, p. 430. Definition. — Feet branched or forked. 6. Calpophcena tet)-acoretJira, u. «p. Sliell subspherical, smooth, with irregular, roundish pores. Basal plate with four larger pores. Apical horn and the four divergent basal feet of equal size and similar form, three to four times as long as the shell, slender, bristle-shaped, curved, in the distal half irregularly branched. (Very similar to the remarkalile Tctraspi/ris tetracordhra, PL 53, figs. 19, 20, but with shorter appendages and with simple spherical shell, wliich exhibits no trace of sagittal ring and constriction.) Dimensions. — Shell 012 diameter, horn and feet 0-.3 to 0'5 long. Habitat. — Central Pacific, Station 271, deptli 2425 fathoms. 7. Calpophmna hexacorethra , n. sp. Shell subspherical, smooth, similar to the preceding species. Basal plate with six pores. Apical horn and the six divergent feet twice to three times as long as the shell, bristle-shaped, irregularly curved and branched. (Similar to Hexaspijris hexacorethra, PI. 95, fig. 8, but without sagittal ring and constriction.) Dimensions. — Shell Oil long, 01.'^ broad ; liorn and feet 0-2 to 0'3 long. Hahitat.-^Gentic&l Pacific, Station 274, deptli 2750 fathoms. Genus 525. Archiphcena,'^ Haeckel, 1881, Prodromus, p. 429. Definition. — A r c h i p li aj u i d a (vel Monocyrtida multiradiata clausa), with simple internal cavity of the shell, without apical horn and axial columella. The genus Archipluena has the same simple cavity of the shell as the preceding Calpophcena, but differs from it in the loss of the apical horn. It bears therefore to the latter the same relation that Gorgosiyyris does to Petalospyris. The two former genera may ha derived from the two latter Ijy loss of the sagittal ring and constriction. ' ArchiplicEna = 'PximoTA\&\. shell ; ajx'j h(ena, Haeckel, 1881, Prodromus, p. 429. Definition. — Feet liranched or forked. 3. ArcMplicBna stephanoma, n. sp. Shell campanulate, somewhat longer than broad, with subregular, circular pores. Margin of the flattened base with a corona of about twenty unequal feet, which are partly simple, partly irregularly branched, and about as long as the shell. Dimensions. — Shell Oil long, 0'03 broad; feet 0'08 to 0'12 long. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Family LXI. C yrtoc alpid A, n. fam. Archicorida et Archicapsida, Haeckel, 1881, Prodromus, pp. 427, 428. Definition. — M onocyrtida eradiata. (Cyrtoidea with a simple, not jointed shell, representing a simple cephalis without radial apophyses.) The family Cyrtocalpida, composed of the Archicorida and Archicapsida of my REPORT ON THE RADIOLARIA. 1179 Prodromus, comprises those C y r t o i cl e a in which the lattice-shell is quite simple, with- out transverse constriction, and without radial apophyses. The two subfamilies differ in the shape of the basal mouth, which in the Archicorida is a simple wide opening, but in the Archicapsida is closed by a lattice-plate. Only a few species of this family were formerly known. Ehrenberg, in 1838, founded upon these the genus Cornutella, one of the three oldest genera of Polj^cystina (Cornutella, LitJiocampe, Haliomnna). In 1862 I described some living forms, with a central capsule, as Cijrtocalpis. The Challenger collection contains a large number of new genera and species. Probal)ly the family Cyrtocalpida is an artificial group, comprising two or more different subfamilies of very different origin. The Cornutellida [Cornutella, Cornu- tanna) have probably been derived from the Sethocorida by loss of the cephalis, so that their conical shell represents a thorax alone. The Mitrocalpida on the other hand (genera 528—531) may be originally simple ovate shells (like Groniia and Lecythium), arising independently from the Nassellida. The Archicapsida (Halicapsa, Archicapsa) are probably derived from the Zygospyrida {Dictyospijris, Circospyris) by loss of the sagittal ring and constriction. This is nearly certain, when the three or four typical cortinar jjores appear in their basal plate. Some forms of Halicapsa may be easily confounded with some forms of Prunoidea [Lithapium). Those Cyrtocalpida, which possess a central capsule with three or four lobes, are probably derived from Tripocyrtida by loss of the three feet, or from Sethocyrtida by loss of the cephalis, since the lobes indicate the original presence of cortinar pores and of a cephalis. Those Cyrtocalpida, however, in which a simple ovate shell encloses a simple central capsule without lobes, may be original " Monocyrtida eradiata," without relation to any radial ancestral forms. Synopsis of the Genera of Cyrtocalpida. I. Subfamily Archicorida. Basal mouth of the shell a simple wide opening. II. Subfamily Archicapsidix. Mouth closed by a lat- tice plate. Shell with simple lattice-work (not ■{ double or spongy). Shell not simply latticed. Shell conical, gradu- j' With horn, ally dilated to ■; wards the mouth. ( No horn, SheU ovate or urceo- j" With horn, late, with con- ■; stricted mouth. ( No horn. Shell ovate, double, with an external mantle, .... Shell ovate, with spongy irregular lattice- work, .... r Shell with an apical horn, Shell without horn on tlie apex, 526. Cornutella. 527. Ciirnutanna. 528. Arrliirory.-'. 529. Cijrtoi:aJ2'U'. 530. Mitrocalin--<. 531. Sponyocyrfit. 532. Halicapsa. 533. Archicapsa. 1180 THE VOYAGE OF H.M.S. CHALLENGER. Suljfamily 1. Archioorida, Haeckel, 1881, Prodromus, p. 427. Definition. — C y r t o calj^ id a, with the basal mouth of the shell open (vel Mono- cyrtida eradiata aperta). Genus 526. CornuteMa,^ Ehrenberg, 1838, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 128. Definition. — A r c h i c o r i d a with conical shell, gradually dilated towards the wide open mouth. Apex armed with a horn. The genus CornuteUa is one of the three oldest genera of Polycystina, described by Ehrenberg, in 1838 [CornuteUa, Lithocampe, and Haliomma). He afterwards enumerated, in 1872 and 1875, a large number of fossil and living species, the majority of which, however, belong to other genera of Monocyrtida and Dicyrtida (at least six or seven different genera). We retain here as the true type of the genus the oldest known species: — CornuteUa clathrata, and the nearly allied foi'ms CornuteUa slijlo- phcBna, CornuteUa initra, CornuteUa circularis, &c. The simple conical shell exhibits no distinct trace of an original cephalis, excepting the apical horn; it may have origin- ated either independently, or been derived from Sethoconus, by loss of the cephalis. Subgenus 1. CornuteUium, Haeckel. Definition. — Axis of the conical shell straight. Pores polygonal, or roundish with polygonal frames. 1. CornuteUa hexagona, n. sp. (PL 54, fig. 9). Shell slender, conical, with straight ontlines. lV>res subregular, liexagoual, gradually increasing in size towards the mouth ; in about ten to twelve longitudinal series, in the upper part very small. Horn slenderly conical, nearly bristle-shaped, long. Dimensions. — Shell O^l to 015 long, 0"04 to 0"06 broad. Habitat. — Central Pacific, Stations 265 to 274, surface, and at different depths. 2. CornuteUa sethoconus, n. sp. (PL 54, fig. 10). Sliell slender, conical, with undulate outlines. I'ores subregular, hexagonal, gradually increasing in size towards the moutli, in aliout fifteen to eighteen longitudinal series, in the upper j^art circular. Horn small, conical, short. The network is not so delicate as in the preceding similar species. Dimensions. — Shell 0-12 to O'lG long, 0-06 to 0-08 broad. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. ' Cornutella=^msXi horn ; diminutive of comu. REPORT ON THE RADIOLARIA. 1181 3. Coniutella distenta, Ehrenberg. Oomnfella disfmta, Ehrenberg, 1872, Abliandl. J. k. Akad. dj Wiss. Berlin, p. 287, Taf. vi. 111. fig. 3. Shell slender, conical, with straight outlines. Pores small, circular, regularly disposed in six to eiglit alternating longitudinal rows, each jiore surrounded by a large rhombic frame. The connected frames form together a regular rhombic framework with obliquely crossed crests. Horn conical, stout, lai'ge. Dimensions. — Shell 01 to 015 long, 0-04 to O'OG broad. Habitat. — North Pacific, Californian Sea, depth 2600 fathoms, Ehrenberg. 4. CornutcUa stiligera, Ehrenberg. Coniufella sfilii/em, Elnenberg, 18.54, Mikrogeol., Taf. xxxvi. fig. 1; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 68, Taf. ii. fig. 3. Shell slender, conical, with straight outlines. Pores subregular, rhombic or nearly square, dis- posed in oblique series, separated by parallel obliquely ascending rings, which are crossed by interrupted parallel bars. Horn slenderly conical or bristle-shaped, tliin and long. Bivmisions. — Shell 0-08 to 012 long, 0-03 to 0-04 long. Habitat. — Fossil in Barbados. Subgenus 2. Cornutissa, Haeckel, 1881, Prodromus, p. 427. Definition. — Axis of the conical shell straight. Pores cii'cular or roundish, without polygonal frames. 5. CornutcUa circularis, Ehrenberg. ComufeUa cimdan'g, Ehrenberg, 1875, Abhandl. d. k. Akad. d. AViss. BerHn, p. 68, Taf. ii. fig. 4. Shell wide, conical or funnel-shaped, with straight outlines. Pores very large, circular, ten to twenty times as broad as the bars, in about nine to twelve longitudinal alternating rows, increasing gradually towards the mouth. Horn very large, cylindrical. Dimensions. — Shell 01 to 015 long, O'OS to 012 broad. Habitat. — Fossil in Barbados. 6. Cornutdla mitra, Ehrenberg. Coniutella mitra, Ehrenberg,; 187 5, Abhandl. d. k. Aiad. d. Wiss. Berlin, p. 68, Taf. ii. fig. 8. Shell wide, conical, campanulate, with convex outKnes. Pores subregular, circular, nearly equal in size, not regularly disposed in rows. Horn conical, stout. Dimensions. — Shell 012 to 016 long, 0-08 to 012 broad. Habitat. — Central Pacific, Station 268, depth 2900 fathoms ; also fossil in Barbados. 1182 THE VOYAGE OF H.M.S. CHALLENGER. 7. Cornutella clathrata, Elireuberg. Cornutella dathrata, Ehrenberg, 1838, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 129; Mikrogeol., Taf. xxii. fig. 39. Cornutella clathrata, Ehrenberg, 1875, Abhandl. d. k. AkaJ. d. AViss. Berlin, Taf. ii. tig. 9. Shell wide, conical, with slightly convex outlines. Pores regular, circular, gradually increasing in size towards the mouth, disposed in twelve to fifteen longitudinal alternating rows. Horn short and stout, conical. (Compare Cornutella curvata.) Dimensions. — Shell 0-15 to 0-2 long, 0-06 to 0-09 broad. HaMtat. — Cosmopolitan ; Atlantic, Indian, Pacific ; also fossil in tertiary rocks of Barbados, Nikobar and Sicily. 8. Cornutella stylophcena, Elireuberg. Cornutella stijlophmna, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. vi. III. fig. 1. ? Cornutella tumens, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. vi. III. fig. 4. SheU slender, conical, with undulate outlines. Pores subregular, circular, gi-adually increasing in size, disposed in six to nine quincuncial alternating longitudinal rows. Horn very long, cylindro- conical, sometimes about as long as the shell. Dimensions. — Shell 01 to OlS long, 0-04 to 0-06 broad. Habitat. — North Pacific, Calif ornian Sea, depth 2600 fathoms. 9. Cornutella gramtlata, Ehrenberg. Cornutella gramtlata, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. vi. Ill fig. 5. Shell slender, conical, nearly cylindrical, with straight outlines, rounded at the apex. Pores very small and numerous, punctiform, disposed into very numerous pai'allel transverse rows. Horn small, conical (may be perhaps the shell of a Tintinnoid Infusorium ?). Dimensions. — Shell O'OS long, 0-02 broad. Habitat. — North Pacific, Californian Sea, deptli 2600 fathoms. 10. Cornutella annulata, Ehrenbero-. Cornutella annulata, Ehrenberg, 1872, Abhandl. d. k. .Vkad. d. Wiss. Berlin, p. 287, Taf. ii. fig. 16. Shell slender, conical, nearly cylindrical, with straight outlines, rounded at the apex. Pores small and numerous, regular circular, of equal size, regularly disposed in ten to fifteen parallel trans- verse series. Horn l)ristle-shaped. (Compare Artostrobus annulatus, Cornutella amiulata, Bailey.) Dimensions. — Shell 01 to 013 long, 0'03 to 0-04 broad. Habitat. — Cosmopolitan, Atlantic, Pacific, surface. REPORT ON THE RADIOLARIA. 1183 Subgenus 3. Cormitosa, Haeckel, 1881, Prodromus, p. 427. Definition. — Axis of the conical shell curved. Pores circular or roundish. 11. Cornutella curvata, Haeckel. Comutella dafhrafa, var., Ehrenberg, 1854, Mikrogeol., Taf. xxii. figs. 39a, b, c. Comutosa clathrafa, Haeckel, 1881, Prodromus, p. 427. Shell slender, conical, with curved axis ; the curve Hes in one plane and is not spirally convoluted. Pores subregular, circular, of nearly equal size, quincuncially disposed. Horn short, conical. Dimensions. — Shell Ol to 015 loug, O'Ol to 0-06 broad. Habitat. — Fossil in tertiary rocks of Sicily (Caltanisetta). 12. Cornutella spiralis, n. sp. Comutura spiralis, Haeckel, 1881, Prodromus, p. 427. Shell slender, conical, nearly cylindrical, very long, spirally contorted ; its axis is an ascending spiral line with two or three windings, widely distant. Pores irregular, square, small and numerous. Dimensions. — Shell 0-2 to 0-25 long, 0-05 to 0-08 broad. HaUtat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 527. Cornutanna,^ Haeckel, 1881, Prodromus, p. 427. Definition. — A r c h i c o r i d a with conical shell, gradually dilated towards the wide open mouth. Apex without horn. The genus Cornutanna has the same simple conical shell as the preceding Cornutella, but differs from it in the total absence of an apical horn. It bears there- fore to the latter the same relation that Cyrtocalpis does to Archicorys. It may be derived from Sethoconus by complete reduction of the cephalis and its horn. 1. Cornutanna orthoconns, n. sp. Shell slender, conical, with straight axis and straight outhnes. Pores subregular, circular, quincuncially disposed in nine to twelve alternating longitudinal series, gradually increasing in size towards the mouth. Dimensions. — Shell 0-1 to 012 long. 0-03 to 0-04 broad. Habitat. — Central Pacific, Stations 270 to 274, surface. 1 CornMi»>.7ris. (ZOOL. CHALL. EXP. — PART XL. — 1886.) Rr 149 1186 THE VOYAGE OF H.M.S. CHALLENGER. the preceding genus Archicorys, from which it differs in the total absence of an apical horn. There is no trace of any triradial structure, excepting in some smaller species, in which the basal part of the central capsule is trilobate ; these may be derived from the Dicyrtides Sethocorys or Dictyocephalus, by loss of the cephalis and the cortinar septum. But the larger species, which have a quite simple, ovate, central capsule (PL 51, fig. 13), have probably an independent origin, from Cystklium. 1. Cyrtocalpis urceolus, n. sp. (PI. 51, fig. 13). Shell smooth, urceolate, with very delicate and elegant network. Pores in the middle part large, regular, hexagonal, towards each pole smaller, irregular, roundish or polygonal. Mouth with broad, hyaline, annular peristome, about one-third as broad as the shell. Bwiensions. — Shell 016 long, 012 broad ; mouth 0'05 broad. Habitat. — Mediterranean (Portofino near Genoa), surface. 2. Cyrtocalpis reticulum, n. sp. Shell smooth, urceolate, very similar to the preceding' species, but diftering from it in the densely reticulated framework of the shell, which is composed of very numerous and small, irregular, polygonal meshes of nearly equal size. Mouth without peristome, half as broad as the shell. Dimensions. — Shell 018 long, 015 broad ; mouth 0'07 broad. Habitat. — Tropical Atlantic, Station .'-)47, depth 2250 fathoms. 3. Cyrtocalpis amphora, Haeckel. Cyrtocalpis ainphum, Haeckel, 1862, Monogr. d. Radiol., p. 286, Taf. v. tig. 2. Shell smooth, urceolate, with regular, circular pores of equal size, of about the same breadth as the bars. Mouth with smooth peristome, about half as broad as the shell. Dimensions. — Shell 012 long, O'OS broad ; mouth Q-Ol broad. Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific ; surface, and at various depths. 4. Cyrtocalpis urna, Stohr. Cyrtocalpis urna, Stohr, 1880, Palaeontogr., vol. x.x.vi. ji. 96, Taf. iii. fig. 7. Shell smootli, urceolate, with subregular, circular pores of different sizes, gradually increasing towards the mouth, of about the same breadth as the bars. Mouth without peristome (?), about half as broad as the shell. Dimensions. — Shell 009 long, 0-06 broad ; mouth 0-035 broad. Habitat. — Fossil in tertiary rocks of Sicily (Grotte). REPORT ON THE RADIOLARIA. 1187 5. Cyrtocalpis sethopora, n. sp. (PI. 52, fig. 4). Shell smooth, urceolate, vei-y thiii-walled, with large irregular roundish meshes, each of which is closed by a thin porous sieve-plate. Mouth two-thirds as broad as the shell, with a broad, emarginate, longitudinally striped peristome. (Perhaps the shell of a Tintinnoid Infusorium ?) Dimensions. — Shell O'OS long, 0-05 broad ; mouth 0-0.3 broad. Hahitat. — Central Pacific, Station 272, depth 2600 fathoms. 6. Cyrtocalpis coinpacta, n. .sp. (PL 52, figs. 7, 8). Shell smooth, ovate, very thick-walled, with small, subregular, circular pores of equal size, perpendicularly perforating the wall, about half as broad as the bars. Mouth small, only one-third as broad as the compact shell. (Perhaps a reduced Lithocanipe or Lithomitra ?) Dimensions. — Shell Q-QS long, 0-04 broad ; mouth 0015 broad. Habitat. — Central Pacific, Station 268, depth 2900 fathoms; also fossil in Barbados. 7. Cyrtocalpis lithomitra, n. sp. (PI. 52, figs. 5, 6). Shell smooth, slender, ovate, nearly cylindrical, with small subregular, circular pores, which are disposed in nine to twelve transverse rows, and obliquely ascencUng perforate the wall. Mouth wide, without peristome, about two-thirds as broad as the shell. (Compare Lithomitra, PL 79.) Dimensions. — Shell 0-09 long, 0-045 broad ; mouth 0-03 broad. Habitat. — Central Pacific, Station 265, depth 2900 fathoms ; also fossil in Barbados. 8. Cyrtocalpis ovulum, u. sp. Cyrtocalpis obliqua, var. ovulum, Haeckel, 1862, Monogr. d. Eadiol., p. 286, Taf. v. fig. .3. Shell smooth, broad, ovate, with very numerous and small regular circular pores, quincuncially disposed, twice as broad as the bars. Mouth without peristome, about half as broad as the shell. Dimensions. — Shell 0-09 long, 0-047 broad; mouth 0-04 broad. Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface. 9. Cyrtocalpis ohliqxia, Haeckel. Cyrtocalpis obliqua, Haeckel, 1862, Monogr. d. Radiol., p. 286, Taf. v. figs. 4-11. Shell smooth, irregularly ovate, more or less obUque, variable in size and form, sometimes nearly spherical, at other times subcyHudrical. Pores subregular, circular, once or twice the breadth of the bars. Mouth simple, without peristome, about half as broad as the shell. Dimensions. — Shell 0-07 to O'l long, 0-05 to 0-08 broad ; mouth 0-03 to 0-04 broad. Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface. 1188 THE VOYAGE OF H.M.S. CHALLENGER. 10. Cyrtocalpis gromia, n. sji. (PI. 51, fig. 11). Shell rough, ovate, very thick-walled, with siibregular, circular pores of somewhat variable size. The diameter of the internal, simple, subspherical cavity is five to six times as gi-eat as the thickness of the wall Mouth tubular, cylindrical, very narrow, only one-sixth as broad as the shell. Dimensions. — Shell 0'16 long, O'll broad; mouth 0'02 broad. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. Genus 530. Mitrocalpis,^ Haeckel, 1881, Prodromus, p. 427. Definition. — A r c h i c o r i d a with a double ovate or ellipsoidal shell, composed of two parallel lattice-plates, which are connected by numerous l)eams. Apex without horn. The genus Mitrocalpis and the following closely allied Spongocfrtis differ from the four preceding genera of Archicorida in the complicated structure of the shell-wall, which in the former is double, in the latter spongy. The mouth is in both genera constricted, narrow, and the apex without a horn. Mitrocalpis has been derived probably from Cyrtocalpis in the same way as Peripijrariiis from Bathropyramis, by development of spines on the surface of the shell, which at equal distances from the latter become connected by branches, thus forming an outer envelojje. 1. Mitrocalpis palliata, n. sp. Shell ellipsoidal, large, one and a third times as long as broad. Inner shell very thin-walled, with irregular, polygonal pores of very variable size and form. From its nodal points there arise numerous bristle-shaped radial beams, about as long as the diameter of the mouth, wliich are connected at equal distances from the surface by delicate threads, forming the outer enveloping shell. The surface of the latter is smooth. The thin bars of the inner shell are twice to four times as broad as those of the outer. Mouth about one-seventh as broad as the shell, with a short tubular peristome. Dinunsions. — Shell 0'35 long, 0"27 broad ; mouth 0"04, distance of both shells 0'037. Habitat. — Central Pacific, Station 271, surface. Genus 531. Spongocyrtis,^ Dunikowski. SjMiu/oci/rtis, Dunikowski, 1882, Denkschr. d. k. AkaJ. d. Wiss. Wien., vol. xlv. p. 31. Definition. — A r c h i c o r i d a with a spongy ovate shell, the wall of which is composed of irregular spongy wickerwork. Apex without horn. The genus Spongocyrtis differs from most other Monocyrtida in the spongy structure of the shell, which is found in only very few^ other genera of C y r t o i d e a, e.g., in Spongopyramis and Spongomelissa. It has been derived either from the similar ' Mitrocalpis = 'V\a\>a,n basket ; fiir^a, xety^Tis. - Spongocyrtis =S]pongy basket; aioyyi, xv^ti;. REPORT ON THE RADIOLARIA. 1189 Cyrtocalpis by developracut of irregular sjiougy wickerwork on the surface of the simple lattice-shell ; or from Arachnocalpis (PI. 98, fig. 13) by loss of the peristome. 1. Spongocyrtis montis ovis, Dunikowski. SpongocyHis moniis ovis, Dunikowski, 1882, Denksclir. J. k. Akad. d. Wiss. Wien., vol. xlv. p. 31, Taf. vi. tigs. 67, 68. Shell broad, ovate, rough, spongy, thick-walled ; length to the breadth = 4 : 3. Spongy frame- work very dense and dark, with very small roundish pores. Mouth constricted, with a short tubular peristome, about one-third as broad as the shell. DiTnensions. — Shell 0'35 long, 0'26 broad ; mouth 0'08 broad. Habitat. — Fossil in the Alpine Lias (Schafberg bei Salzburg, Dunikowski). 2. Spongocyrtis arachnoides, n. sp. Shell ellipsoidal, spiny, spongy, thin-walled ; length to the breadth =3:2. Spongy frame- work loose and dehcate, with irregular polygonal meshes and arachnoidal thread-like bars. Mouth constricted, without peristome, about one-fifth as broad as the shell. (Very similar to Arachnocalpis ellipsoides, PI. 98, fig. 13, but without corona around the mouth.) Dimensions. — Shell 0'32 long, 0-21 broad; mouth 0-04 broad. Habitat. — Central Pacific, Station 270, depth 292.5 fathoms. Subfamily 2. Akchicapsida, Haeckel, 1881, Prodromus, p. 428. Definition. — C y rt o c al p id a, with the basal mouth of the .shell fenestrated (vel Monocyi'tida eradiata clausa). Genus 532. Halicapsa,^ Haeckel, 1881, Prodromus, p. 429. Definition. — A rchicapsida with an apical horn. The genus Halicapsa, and the following closely allied Archicapsa, represent together the small subfamily of Archicapsida, or of those Cyrtocalpida, in which the basal mouth of the simple shell is closed by a lattice plate. This may be the original state of this family, if it is derived from the Cireospyrida (Circospyris, Dictyospyris) by loss of the sagittal constriction and the primary ring. But it is also possible that the Archicapsida have been partly derived from the Archicorida by secondary fenestration of the open mouth. The genus Halicapsa may be easily confounded with the similar EUipsid Lithapium (compare p. 303, PL 14, figs. 8—10). The skeleton of both genera may be perfectly similar, the only distinction being the structure of the central capsule, which in Halicapsa is that of the Monopylea, in Lithapium that of the Pekipylea. ' fiaHcapsa = Sea-capsule ; a>i£, xa\^«. 1190 THE VOYAGE OF H.M.S. CHALLENGER. Subgenus 1. Calpocapsa, Haeckel. Definition. — Surface of the shell smooth or rough, but uot spiny. 1. Haliccqisa lithapium, n. sp. (PL 97, fig. 6). Shell pear-shaped, rough, one and a half times as long as broad. Pores subregular, circular, twice as broad as the bars. Basal plate with four larger ovate cortinar pores (two larger cardinal and two smaller jugular), and with six smaller peripheral pores (fig. 6). Horn of the apex three- sided pyramidal, stout, half as long as the shell. Dimensions- — Shell 0'16 long, O'l broad ; horn 0"08 long. Eahitat. — North Pacific, Station 244, depth 2900 fathoms. 2. Halicapsa triglochin, n. sj). (PI. 53, figs. 3, 4). Shell ovate, rough, a little longer than broad. Pores regular, chcular, hexagonally framed, of the same breadth as the bars. Basal plate (fig. 4) without larger pores. Horn pyramidal, stout, about half as long as the shell, with three short, horizontally divergent secondaiy spines at the base (possibly remnants of three original cortinar feet ?) Dimensions. — Shell Oil long, G'09 broad; horn 0'06 long. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 3. Halicapsa pninoides, n. sp. • Shell pear-shaped, tuberculate, a little longer than broad. Pores irregular, roundish, of different sizes. Basal plate with four larger and six smaller pores. Horn pyramidal, stout, about one-third as long as the shell. (May belong perhaps to the similar P r u n o i d e a Lithapiuvi, compare p. 303 and PL 14, figs. 8-10.) Dimensions. — Shell 0'14 long, 0'12 broad; horn 0'05 long. Habitat. — Fossil in Barbados. Subgenus 2. Echinocapsa, Haeckel, 1881, Prodromus, p. 429. Definition. — Surface of the shell spiny, covered with thorns, papillae or larger spines. 4. Halicapsa papillata, n. sp. Shell bottle-shaped, papillate, one and a half times as long as broad. Pores circular, much larger in the middle part than towards the poles. The elevated frames between them bear on the REPORT ON THE RADIOLARIA, 1191 nodal points large blunt conical papillte. Basal plate without larger pores. Horn three-sided pyramidal, one-third as long as the shell, gradually passing into the slender neck of the bottle. Dimensions. — Shell 0-22 long, 015 broad ; horn O'OT long. Eabitat. — Central racific, Station 265, depth 2900 fathoms. 5. Halicapsa pyriformis, Haeckel. ? Haliomma pyriforme, Bailej', 1856, Amer. Journ. Sci. and Arts, vol. xxii. p. 1, pi. i. fig. 29. Shell pear-shaped, a little longer than broad, covered with numerous short conical spines Pores subregular, circular, of nearly equal size, twice as broad as the bars. Basal plate with four crossed larger ovate pores (two larger cardinal and two smaller jugular pores). Horn stout pyramidal, scarcely one-fourth as long as the shell. Dimensions. — Shell 016 long, 014 broad ; horn O'Ol long. Habitat. — Fossil in Barbados, living in the North Pacific (Kamtschatka) ? 6. Halicapsa hystrix, n. sp. (PI. 53, figs. 5, 6). Shell pear-shaped, subspherical, a little longer than broad, with scattered stout pyramidal spines about as long as the radius of the shell. Pores subregular, circular, three times as broad as the bars. Basal plate (fig. 6) without larger pores. Horn very large, pyramidal, longer than the shell. Dimensions. — Shell 01 long, 0'09 broad; horn 013 long. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. Genus 533. Archicapsa,'^ Haeckel, 1881, Prodromus, p. 428. Definition. — A r c li i c a p s i d a watliout apical horn. The genus Archicap>sa difi'ers from the preceding Halicapsa in the absence of the apical horn, and represents the simplest form among the Monocyrtida clausa, a simple, ovate, or pear-shaped shell without any appendages. The characteristic structure of the basal lattice-plate (with three or four large cortinar pores) makes it probable that Archicapsa has been derived either from Halicapsa, by loss of the horn, or directly from Dictyospyris, by reduction of the sagittal ring and constriction. 1. Archicajosa triforis, n. sp. (PI. 53, figs. 1, 2). Shell pear-shaped, smooth, one and a half times as long as broad. Pores subregular, circular, of about the same breadth as the bars. Basal plate (fig. 2) with three very large pores, three times as broad as the others (one odd sternal pore and two paired cardinal pores). Dimensions. — Shell 0'09 long, 0'06 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. ' Archicapsa = Primordial capsule ; i»5x'''!«'<|'«. 1192 THE VOYAGE OF H.M.S. CHALLENGER. 2. Archicapsa quadriforis, n. sp. Shell ovate, rough, a little longer than broad. Pores subregular, circular, twice as broad as the bars. Basal plate with four larger ovate cortinar pores (two smaller jugular and two larger cardinal pores). Dimensions. — Shell 012 to 015 long, 01 to 012 broad. Habitat. — Central Pacific, Station 265 to 268, depth 2700 to 2900 fathoms. 3. Archicapsa nonaforis, n. sp. Shell pear-shaped, thorny, one and a half times as long as broad. Pores regular, circular, small, hexagonaUy framed, twice as broad as the bars. Basal plate with nine cortinar pores (three larger alternating with three pairs of smaller pores, as in PI. 87, fig. 2). Dimensions. — Shell 014 long, 0"09 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. Section II. DICYRTIDA, Haeckel, 1862, Monogr. d. Radiol., pp. 280, 296. Definition. — C y r t o i d e a dithalamia, with two-jointed shell, being divided by a transverse collar stricture into an apical joint (or cephalis) and a basal joint (or thorax). Synopsis of the thi^ee Families and six Subfamilies of Dicyrtida. i Mouth open, . . . . .1. Sethopilida. Family LXII. Tripocyrtida. Three radial apophyses. Family LXIIL AntliocyrtiJa. Numerous radial apophyse.s. Family LXIV. Sethocyrtida. No radial apophyses. ( Mouth closed, Mouth open, Mouth closed, i Mouth open, ( Mouth closed, 2. Sethoperida. 3. Sethophormida. 4. Sethophaenida. .5. Sethocorida. 6. Sethocapsida. Family LXII. Tripocyrtida, n. fam. Sethopilida et Sethoperida, Haeckel, 1881, Prodromus, pp. 431, 433. Definition. — D i c y r t i d a triradiata. (Cyrtoidea with a two-jointed shell, divided by a transverse constriction into cephalis and thorax, and bearing three radial apophyses.) KEPORT ON THE RADIOLARIA. 1193 The family T r i p o e y r t i d u, composed of the Sethopilida and Sethoperida of my Prodromus, comprises those Cyrtoidea in which the lattice-shell is two-jointed and bears three radial apophyses. The two subfamilies diifer in the shape of the mouth, which in the Sethopilida is a simple wide opening, but in the Sethoperida is closed by a lattice -plate ; the former are here divided into sixteen, the latter into eight diflerent genera. Though probably the two shell -joints are not truly homologous in aU Tripocyrtida, we call the first joint here, as in all Dicyrtida, the cephalis, and the second joint the thorax. Numerous Trijjocyrtida, living as well as fossil forms, were formerly described by Ehrenberg. His genera Dictyophimus, Claihrocanium, Lithomelissa, and Lychno- canium belong to the Sethopilida, and have the mouth open; his genera Lithopera and Lithochytris (partly) belong to the Sethoperida, and have the basal mouth closed by a lattice-plate. Many of these Tripocyrtida belong probably to the oldest forms of Dicyrtida, are nearly related to the Phormospyrida, and therefore of special phylogeuetic interest, as was demonstrated by Biitschli (1882, loc. cit., jjjx 514-519). This near relation to certain Spyroidea {Trqwspyris, Acrospyris, &c.) is particularly striking in some forms of Clathrocanium, Lithomelissa , &c. Some other Tripocyrtida seem to possess a closer relation to certain Plectoidea (Plar/oniscus, Plectaniscus), so mainly some forms of Tripocyrtis and Dictyophimus. The cephalis, or the first joint of the shell, corresponds usually to the whole shell of the Zygospyrida and of numerous Monocyrtida, and exhibits various modifications of shape, which have been already described in these latter families. It is usually subspherical or hemispherical and armed with an apical horn. In a small number of genera the horn is lost, in some other genera multij^lied. The cephalis is separated from the thorax not only externally by the collar constriction, but commonl}^ also internally by a transverse horizontal fenestrated septum, which usually exhibits three or four characteristic cortinar pores. The central capsule, originally enclosed in the cephalis, develops usually three or four large pear-shaped csecal sacs which pass through the cortinar pores and depend into the thorax (PI. 55, figs. 2—11 ; PI. 60, figs. 3-7, &c.). The thorax in this famdy exhibits a great variety of interesting modifications, mainly in the development of the three radial apophyses arising from it. These may be either enclosed in the wall of the thorax as ribs, or arise as free wings, very often prolonged over the mouth as three terminal feet. Finally the three terminal feet only remain, whilst the original ribs are lost. The special ornamentation of these three apophyses exhibits an extraordinary variety and elegancy of structure, and many Tripo- c}T.-tida belong, no doubt, to the most graceful and admirable forms of Nassellaria. CZOOL. CHALL. EXP. — PART XL. — 1886.) Er 150 1194 THE VOYAGE OF H.M.S. CHALLENGER. Synopsis of the Genera of Tripocyrtida. a. Three tlio- f -n i v i ^ " -b set solid, A. Three radial ribs(orcortinar rods) partly or completely en- closed in the wall of the thorax. Xo latticed vertical cephalic wings. L Subfamily Sethopilida. Terminal mouth of the thorax a simple wide open- ing. IL Subfamily Sethoperida. Terminal mouth of the thorax closed by a lattice-plate. racic ribs pro- longed into three terminal feet. h. Three tho- racic ribs pro- longed into three lateral win<;s. c. Three tho- racic riljs com- pletely enclosed I in the wall of [ the flat thorax. Cephalis I with a horn. \ Feetlatticod, Xo horn, feet solid, Thorax per- ( -^vjtii hom fectly hit. - ticed. ( No horn, . Thorax with spongy frame- work. Thorax with three large lateral holes between the three ribs, Peristome simple, smooth, . Peristome with a corona of spines, . E. Three radial ribs enclosed in the wall of the thorax and connected with the cephalic horn by three latticed vertical C. Three radial beams (or cor- tinar rods) per- fectly free, not enclosed in the wall of the thorax. «. Thorax com pletely latticed I No frontal horn (four spines), 1 With frontal horn (five ' spines), . b. Thorax witli three large lateral holes between the three ribs. No frontal horn, . Three beams outside the thorax, arising freely from the collar stricture (no cephalic hole). Three beams inside the thorax. Ceplialis with a large apical hole. D. Three radial terminal feet on \ the [leristome (the three original J- lateral ribs are lost). j Thi-ee divergent ribs (or cortinar rods) enclosed either in the wall or in the cavity of the thorax. Three divergent free lateral wings (as prolongation of the three ribs) on the sides of the thorax. Three free terminal feet (on the base of the thorax). Feet solid, . Feet latticed. Three ribs enclosed in the lattice-wall of the thorax, Three internal rods in the cavity of the thorax. Three solid f Cephalis lateral ■) spines. [ ^o ^orn, . Throe latticed lateral wings. With horn, Three feet solid. with horn. Three feet latticed. Shell with- out exter- nal mantle, Shell with an arachnoidal mantle. SSi. Dic1yo2jhimus. 535. Tripocipiis. 536. SeiJwpi'Hum. 537. LUhomelissa. 538. Psilomelissa. 539. Spoiigomelissa. 540. Clathrocanium 541. Lamprodiscus 5412. Lampromitra. 543. Cullhnitya. 544. Clafliromifrn. 545. Clafhrocori/a. 546. Eucecryphalus. 547. Ampihiplecfft. 548. Li/c/i II ocan ium. 549. Lychnodidijum. 550. Sethopjera. 551. Litliopera. 552. Micromelissa. 553. Peromelissa. 554. SethomeUssa. 555. TetraJiedrina. 556. Setliochyin's. 657. Clathrohjclmiis. REPORT ON THE RADIOLARIA. 1195 Subfamily 1. Sethopilida, Haeckel, 1881, Prodromus, p. 431. Definition. — T r i }) o c y r t i d a, with the basal mouth of the shell open (vel Dicyr- tida triradiata aperta). Genus 534. Dictyophimus,^ Ehrenberg, 1847, Monatsber. d. k. preuss, Akad. d. Wiss. Berlin, p. 53. Definition. — S e t h o p i 1 i d a (vel Dicyrtida triradiata aperta) with three complete thoracic ribs, prolonged into three solid divergent feet on the peristome. Cephalis with an apical horn. The genus Dictyophimus, comprising many common species, may be regarded as the common ancestral form of all Sethopilida, and therefore also of the whole family of Dicyrtida. The cephalis bears an apical horn, and the thorax three ribs, which are prolonged over the open mouth into three solid feet. Dictyophimus may be derived either from Eusceniuni or Peridium (Archiperida), or from Tripospyris (Zygospyrida), or from Plectaniscvs (Plectanida), by development of lattice-work between the three terminal feet, which therefore become thoracic ribs. Subgenus 1. Dictyophimium, Haeckel. Definition. — Shell smooth or rough, -ndthout prominent spines on the edges of the three thoracic ribs. (Commonly one single horn on the cephalis.) 1. Dictyophimus spharocephalus, n. sp. (PL 57, %. 10). Shell smooth, with a deep collar stricture, separatiug two joints of nearly equal size. Cephalis subglobular, rough, with a stout pyramidal horn of half the length, and regular, circular, hexagonally framed pores. Thorax nearly three-sided prismatic, smooth, with three stout, little divergent or nearly parallel ribs, which are prolonged into conical subvertical feet half as long. Thoracic pores irregular, roundish. Dimensions. — Cephalis 0-08 long, O'OS broad ; thorax O'OS long, 0-08 broad. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 2. Dictyophimus tripus, Haeckel. Dictyophimus tripus, Haeckel, 1862, Monogr. d. Eadiol., p. 306, Taf. vi. fig. 1. Shell with a slight collar stricture, separating two joints of slightly differen't size. Cephalis nearly eUipsoidal, large, with a slender conical horn of the same length. Thorax truncate three-sided ■ Dictyophimtis = ^et goljlet ; oiV-ti/oi/ Jsiui:. 1106 THE VOYAGE OF H.M.S. CHALLENGER. pyramidal, with three strongly divergent ribs, which are prolonged into three slender conical feet of about the same length. Pores irregular, roundish, of variable size. Biviensions. — Cephahs 0'032 long, 0"028 broad ; thorax 0-34 long, 0-064 broad. Habitat. — Mediterranean (Messina), Atlantic (Canary Islands), surface. 3. Dictyophimus plectaniscus, n. sp. (PL 61, figs. 8, 9). Shell flat, pyramidal, smooth, with distinct collar stricture. Cephalis hemispherical, with a conical horn of the same length and numerous small regular pores. Thorax flat, triangular, pyramidal, with three widely divergent ribs, which are prolonged into three cylindrical feet of the same length. Thoracic pores fifteen, very large, subregular, roundish, disposed in two transverse girdles, the inner with six, the outer with nine pores ; five pores between every two ribs. Dimensions.- — Cejihalis 0'04 long, 0'06 broad ; thorax O^OS long, 018 broad. HaMtat. — Central Pacific, Station 265, depth 2900 fathoms. 4. Dictyoiohimiis craticula, Elirenberg. Dictyophimus craticula, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. V. figs. 4, 5. Dictijopliimus craticula, Biitschli, 1882, Zeitschr. f. Wiss. Zool., vol. xxxvi. p. 515, Taf. xxxiii. fig. 35. Shell flat, pyramidal, very similar to the preceding species, but differing in the rudimentary horn, which is smaller than half the cephalis, and in the length of the three cylindrical feet, which are twice to three times as long as the shell. The nine inferior large pores of the thorax are twice to three times as large as the six superior pores. The basal peristome is commonly thorny. Dimensions. — Cephalis 0'04 long, 0'05 broad ; thorax 01 long, 0"2 broad. Habitat. — Fossil in Barbados. 5. Dictyophimus pyramis, Ti. sp. (PL 61, fig. 16). Shell regular, pyramidal, with flat collar stricture. P»elative length of the two joints = 1:4, breadth = 2:6. Cephalis hemispherical, with a stout pyramidal horn of the same length. Thorax triangular pyramidal, with three prominent ribs, which are prolonged into three slender pyramidal feet, half as long. Pores small and very numerous, subregular, circular. Dimensions. — Cephalis 0'03 long, 0'05 broad ; thorax 01 long, 015 broad. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. G. Dictyophimus challengeri, Haeckel. Dictyophimus challengeri, Haeckel, 1878, Protistenreich, p. 47, fig. 35. Shell campanulate, with sharp collar stricture. Eelative length of tlie joints = 1:3, lu-eadth 1:4. Cephalis subspherical, with a stout pyramidal horn of twice the length, and numerous REPORT ON THE RADIOLARIA. 1197 very small pores. Thorax nearly hemispherical, with three vaulted bosoms between the three decurrent ribs, which are prolonged into three nearly parallel and vertical feet of about the same length. Pores subregular, circular, of medium size. This species is very similar to Lychnodictyum challengeri, Haeckel, but differs in the smaller straight horn and the longer solid feet, which are not fenestrated. Dimensions. — Cephalis 0'03 long, 0'04 broad ; thorax 0'09 long, 013 broad. Habitat. — Tropical Atlantic, Station 347, surface. 7. Dictyophimus lasanum, n. sp. (PI. 61, fig. 5). Shell nearly pear-shaped, with distinct collar stricture. Pielative length of the two joints = 1 : 3, breadth =1:3. Cephalis hemispherical, with a conical horn of the same length. Thorax nearly spherical, on both poles truncate and constricted, with three decurrent curved ribs and small regular circular pores. The prolongations of the ribs form three divergent pyramidal straight feet, nearly as long as the thorax. Dimensions. — Cephalis 0'02 long, 0'03 broad ; thorax 0-09 long, 0'09 broad. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 8. Dictyojyhimus longipes, n. sp. (PL 61, fig. 3). Shell three-sided pyramidal, with distinct collar stricture. Pielative length of the two joints = 1:4, breadth = 2 : 6. Cephalis hemispherical, with a rudimentary pyramidal horn, scarcely one-fourth as long ; and with small circular regular pores. Thorax with larger irregular pores, and three vaulted bosoms between the three decurrent ribs, which are prolonged into three very long and slender prismatic feet, S-shaped, curved, and twice to three times as long as the shell. Dimensions. — Cephalis 0'02 long, 0'04 broad ; thorax 0'09 long, 013 broad. Habitat. — South Pacific, Station 300, depth 1375 fathoms. 9. Dictyoiihimus gracilipes, Bailey. Didijophimus gracilipes, Bailey, 1856, Amer. Journ. Sci. and Arts, vol. xxii. p. 4, pi. i. fig. 8. Shell three-sided pyramidal, with a deep collar stricture. Eelative length of the two joints = 1 : 3, breadth = 1:4. Cephalis hemispherical, with a thin horn of the same length. Thorax with three curved ribs, which are prolonged into three divergent angular feet of the same length. Pores irregular roundish. Dimensions. — Cephalis 002 long, 0-03 broad ; thorax O'OS long, 0-08 broad. Habitat. — North Pacific, Station 240, surface, Kamtschatka (Bailey). 10. Dictyo2)himns cortina, n. sp. (PL 61, fig. 1). Shell three-sided pyramidal, with distinct collar stricture. Eelative length of the two joints = 1:3, breadth =1:4. Cephalis subspherical, with a pyramidal horn of half the length. Thorax 1198 THE VOYAGE OF H.M.S. CHALLENGER. with much larger irregular roundish pores and three prominent ribs, which are prolonged into three stout, club-shaped, strongly divergent feet of the same length. Mouth widely open, elegantly coronate, with a circle of numerous small cilia. Dimensions. — Cephalis 0'02 long, 0-03 broad ; thorax 0-06 long, 0-08 broad. Hahitat. — Central Pacific, Station 272, depth 2600 fathoms. 11. Dictyophimus arabicus, Haeckel. Lychnocanium arabicum, Ehronberg, 1872, Abliandl. d. k. Ak'ad. d. Wiss. Berlin, p. 296, Taf. X. fig. 3. Shell smooth, three-sided pyramidal, with deep collar stricture. Eelative length of the two joints = 1:3, breadth = 1:4. Cephalis subspherical, with a slender horn of the same length. Thorax with much larger, irregular roundish pores, and three widely divergent ribs, which are prolonged into three slender, somewhat recurved feet of about the same length. Dimensions. — Cephalis 0'02 long, 0"02 broad ; thorax 0'07 long, 0'09 broad. Hahitat. — Indian Ocean, Zanzibar (Pullen), depth 2200 fathoms. 12. Dictyophimus platycephalus, n. sp. (PI. 60, figs. 4, 5). Shell smooth, flat, three-sided pyramidal, with distinct collar stricture. Eelative length of the two joints =1:3, breadth = 3:9. Cephalis iiat, cap-shaped, three times as broad as long, with a slender conical horn of the same length. Thorax flatly vaulted, with much larger, irregular roundish, double- edged pores, and three widely divergent ribs, which are prolonged into three slender conical feet of the same length. Central capsule in the cephalis flat, discoidal, with a discoidal nucleus of half the size, and with four large pear-shaped crecal sacs depending into the thorax, each of which contains a large oil globule (fig. 4). Dimensions. — Cephalis 0'02 long, 0'07 broad ; thorax 0'06 long, 018 broad. Habitat. — North Atlantic, Canary Islands (Lanzerote), Haeckel, surface. 13. Dictyophimus hrandtii, ii. sjj. (PI. 60, fig. 6). Shell smooth, flat, three-sided pyramidal, with deep collar stricture, very similar to the preced- ing species. Eelative length of the two joints =1:3, breadth = 2:7. Cephalis hemispherical, with a slender conical horn of twice the length. Thorax flatly vaulted, with irregular polygonal pores and thin bars ; and with three widely divergent ribs, which are prolonged into three slender prismatic feet of thrice the length. In fig. 6 the shell is seen from the base and exhibits very distinctly the collar septum with its four large meshes, two minor jugular and two major cardinal pores. Dimensions. — Cephalis 0-03 long, 0-07 broad ; thorax O'OB long, 0'2 broad. Habitat. — North Pacific, Station 236, surface. REPORT ON THE RADIOLARIA. 1199 14. Divtyophimus lucerna, Haeckel. Lycltnoraniinii hicerim, Ebrenberg, 1854, j\Iikrogeol., 1"af. xxxvi. fig. 6 ; Abliandl. d. k. Akad. d. Wis.<;. Berliu, 1875, p. 80, Taf. viii. fig. 3. Li/rJnKirai/uan lurcrna, Haeckel, 1862, Monogr. d. Radiol., p. 311. Shell smooth, three-sided pyramidal, with slight collar stricture. Relative length of the two joints = 1:4, breadth = 1:4. Cephalis hemispherical, with a thick conical horn of twice the length. Thorax with small regular, circular pores and three flat sides ; between these arise three rounded ribs, which are prolonged into three short, conical, divergent feet, one-third as long as the thorax. Bimensiom. — Cephalis 0-02 long, 0-025 broad ; thorax O'OS long, O'OS broad. Habitat. — Fossil in Barbados. 15. Dietyoiohimus hamosus, Haeckel. Lychnocanium hamosum, Ehrenherg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. vii. fig. 9. Shell pear-shaped, rough, with deep collar stricture. Eelative length of the two joints = 1:2, breadth = 1:3. Cephalis subglobular, with a conical horn of twice the length. Thorax with small, regular, circular pores, and with three prominent ribs, prolonged into three vertical prismatic feet, which are about as long as the shell, parallel or a little convergent towards the distal end, with recurved teeth or hooks at the lateral edges. Dimensions. — Cephalis 0'02 long, 0'02 broad ; thorax O^Ol long, 0-06 broad. Habitat. — Fossil in Barbados. 16. Dictyophimus trideniatus, Haeckel. Lychnocanium tridentatum, Ehrenberg, 1875, AbLandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. vii. fig. 4. Shell smooth, three-sided pyramidal, with deep collar stricture. Eelative length of the two joints = 1:3, breadth =1:4. Cephalis subspherical, with a conical horn of the same length, and some small accessory thorns. Thorax tetrahedral, with three smooth hyaline walls, bearing only a single series of small pores on each side of the three pi eminent ribs, which are prolonged into three strong prismatic curved feet of twice the length, with the convexity external. A group of small pores and a strong triangular tooth at tlie base of each foot. Binu'iisions. — Cephalis 0-02 long, 0'02 broad ; thorax 006 long, 0-08 broad. Habitat. — Fossil in Barbados. Subgenus 2. Lamprotripus, Haeckel, 1881, Prodromus, p. 432. Definition. — Shell spiny or thorny, with prominent spines on the edges of the three thoracic ribs. (Commonly one larger and a few smaller horns or spines on the cephalis.) 1200 THE VOYAGE OF H.M.S. CHALLENGER. 17. Dictyophimvs triserratus, u. sp. (PI. 61, fig. 17). Shell three-sided pyramidal, with sliglit collar stricture. Eelative length of the two jonits = 1 : 3, breadth = 1:4. Cephalis small, subspherical, with a large pyramidal horn three times as long. Thorax with much larger, irregular roundisli, double-edged pores, and three prominent, serrate ribs, which are prolonged into three pyramidal strongly divergent feet of the same length. Dimensions. — Cephalis 0'02 long, 0-02 broad ; thorax 0'06 long, 0'09 broad. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 18. Dictyophimus hicornis, u. sp. Shell thorny, with deep collar stricture. Eelative length of the two joints = 2:3, breadth = 2:3. Cephalis nearly as large as the thorax, subglobular, with numerous small, circular pores, and two divergent pyramidal horns of half the length (a major occipital and a minor frontal horn). Thorax three-sided pyramidal, with larger irregidar pores and three serrate ribs, which are prolonged into three prismatic spiny feet of half the length. (Differs from the smiilar Dictyophimus S2jh(croceplialus, PI, 57, fig. 10, mainly in the double horn and the spinulate feet.) Dimensions. — Cephalis 0'05 long, 0-05 broad ; thorax O'OS long, 0'07 broad. Habitat. — Western Tropical Pacific, Station 225, deptli 4475 fathoms. 19. Dictyophimus pocilhim, Ehrenbcrg. Dictyophimus pocillum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. v. fig. 6. Shell thorny, with distinct collar stricture. Eelative length of the two joints = 1:5, breadth = 1:5. Cephalis nearly spherical, with numerous small conical spines. Thorax flat, three-sided pyramidal with large, irregular, roundish pores, and three sti-ong, widely divergent, spinulate ribs, which are prolonged into three prismatic spinulate feet of the same length. Dimensions. — Cephalis 0'03 long, 0-03 broad ; thorax 015 long, 015 broad. Hiibitat. — Fossil in Barbados. 20. Dictyophimus cienkowskii, n. sp. (PI. 60, fig. 1). Lamprotripus S(]uarrogus, Haeckel, 1881, Prodromus et Atlas. Shell spiny, flatly pyramidal, with slight collar stricture. Eelative length of the two joints = 1:3, breadth = 2:6. Cephalis flat, cap-shaped, three times as long as broad, with numerous bristle- shaped spines three times as long. Thorax also spiny, with irregular, very large, polygonal meshes and thin bars ; its three ribs ])rolonged into three very long and thin, widely divergent, prismatic feet, bearing numerous long spines on the three edges. Dimensions. — Cephalis 0-025 long, 0-05 broad ; thorax 0-075 long, 0-15 broad. Habitat. — North Pacific, Station 250, surface. RErOET ON THE EADIOLARIA. 1201 21. Dk-tyophimus hiitscldii, u. sp. (PI. 60, fig. 2). Lamprotripwi Iwrviilua, Haeckel, 1881, Prodromus et Atlas. Shell spiny, flatly pyramidal, with deep collar stricture. Relative length of the two joints = 1:2, breadth = 1:5. Cephalis subspherical, with numerous long, bristle-shaped spines and a larger ranrified horn. Thorax also spiny, flatly vaulted, with large, subregular, hexagonal meshes and thin bars ; its three spiny ribs prolonged into three very long and thin, prismatic, widely divergent feet, twice to four times as long as the thorax. Dimcnsiom. — Cephalis 0-04 long, O'Ol broad; thorax 0-08 long, 0-2 broad. Habitat. — South Pacific, Station 284, surface. 22. Dictyophimus hertwigii, n. sp. (PL 60, fig. 3). Lamprotrq^us spinosus, Haockel, 1831, Prodromus et Atlas. SheU spiny, flatly pyramidal, with sharp collar stricture. Relative length of the two joints = 1:2, breadth = 1:5. Cephalis subspherical, with irregular roundish pores, numerous small spines and a large, oblique, prismatic horn of the same length, bearing on its distal end a bunch of small divergent spines. Thorax pyramidal, with larger irregular polygonal pores and thin bars ; its three strong, widely divergent ribs spiny, straight, and prolonged into three prismatic slender feet of the same length. Central capsule with three lobes depending into the thorax. Dimensio7is. — Cephalis 0-04 long, 0-04 broad ; thorax O'OS long, 0-2 broad. Habitat. — Central Pacific, Stations 270 to 274, surface. Genus 535. Tripocyrtis,^ n. gen. Definition. — Sethopilida (vel Dicyrtida triradiata aperta) wdtli three complete thoracic ribs, prolonged into three latticed divergent feet on the peristome. Cephahs with an apical horn. The genus Tripocyrtis has been derived from the preceding Dictyophimus by com- plete fenestration of the three basal feet, which throughout their whole length become united by complete lattice-work. This genus is closely allied to Pleetaniscus. 1. Tripocyrtis plagoniscus, u. sp. (PI. 60, fig. 10). CephaUs subspherical, with large, roundish meshes and a stout, three-sided pyramidal, irregularly branched horn of twice the length. Thorax with a small number of large, irregular, polygonal meshes and three stout curved ribs about as long as the cephahc horn. Dim.ensians. — Cephalis 0-06 long, 0-07 broad ; thorax Oil long, 016 broad. Habitat. — Central Pacific, Station 266, surface. ^ Tripocyrtis = Basket with a tripod ; rj/ro;, xi/jt/;. (ZOOL. CHALL. EXP. — PART XL. — 1886.) Pr 151 1202 THE VOYAGE OF H.M.S. CHALLENGER. 2. Tripocyrtis tri^wdiscus, n. sp. Cephalis subspherical, with small, polygonal pores and a large, arborescent, vertical horn of thrice the length, bearing numerous ramified branches. Thorax with three straight, widely divergent ribs, of the same length as the horn, connected by a delicate, arachnoidal framework with irregular, polygonal meshes. Dimensions. — Cephalis 0-04 long, 05 broad ; thorax 0-12 long, 018 broad. Habitat. — Central Pacific, Station 269, surface. 3. Tripocyrtis plectaniscus, n. sp. (PI. 60, fig. 9). Cephalis subspherical, with small roundish pores, and a stout, three-sided pyramidal, denticulate horn of the same length. Thorax with three little divergent and curved ribs, twice as long as the horn, in the upper half with smaller, in the lower half with larger, polygonal, irregular meshes. Dimensions. — Cephalis 0'05 long, 0'06 broad ; thorax 01 long, 012 broad. Habitat. — Central Pacific, Station 264, surface. Genus 536. Sethopilium^ Haeckel, 1881, Prodromus, p. 431. Definition. — Sethopilida (vel Dicyrtida triradiata aperta) with three complete thoracic ribs, which are prolonged into three solid divergent feet on the peristome. Cephalis smooth, without a horn. The genus Sethopilium diflers from its probable ancestral form Dictyopkimus by the complete loss of the cej^halic horn, and of the collar septum between both joints, which are only separated by the slight external collar stricture. 1. Sethopilium orthopus, n. sp. (PL 97, fig. 8). Shell smooth, with sharp collar stricture. Eelative length of the two joints— 5 : 4, breadth = 7:6. Cephalis large, subspherical, with numerous regular circular pores, twice as broad as the bars. Thorax with tliree stout, straight, widely divergent ribs, prolonged into three straight pointed feet of the same length. Between every two ribs, in the centre of the collar stricture, a single large triangular mesh, and beyond this three to six rows of smaller irregular meshes. Dimensions. — Cephalis 0'05 long, 0'07 broad ; tliorax 0-04 long, 0-06 broad. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Sethopilium cyrtoptis, n. sp. Shell smooth, with sharp collar stricture. Eelative length of the two joints = 4:5, breadth = 7 : 11. Cephalis hemispherical, with large irregular roundish pores, four times as broad as the bars. * SeihopiUwm = Bmai\ lenestrated hat ; aiiia, 'Kihinv. REPORT ON THE RADIOLARIA. 1203 Tliorax with three stout, curved, widely divergent ribs, prolonged into three cylindro-conical, curved feet of twice the length, which are convex in the proximal half, concave in the distal half. Between every two ribs, beyond the collar stricture, two large ovate meshes, and beyond this two rows of smaller irregular meshes. Dimensions. — Cephalis 0'04 long, 0'07 broad; thorax 0-05 long. Oil broad. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 3. Sethopiliiim macropuii, n. sp. (PL 97, fig. 9). Shell smooth, with slight collar stricture. Eelative length of the two joints =; 4 : 7, breadth = 6:13. Cephahs hemispherical, with irregular double-contoured pores, about as broad as the bars. Thorax with three very stout, curved, widely divergent ribs, prolonged into three curved, cylindrical, very long feet, which are three to four tunes as long as the shell, and convex on the outside. Between every two ribs, beyond the collar stricture, two large broad meshes, and lieyond this two or three rows of smaller meshes. i)i'mCTmoKs.— Cephalis G'04 long, 0'06 broad ; thorax 0'07 long, 0'13 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 537. Lithomelissa,^ Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Definition. — S e t h o p i 1 i d a (vel Dicyrtida triradiata aperta) with three free lateral mngs, or solid spines arising from the sides of the tliorax. No terminal feet. Cephalis with one or more horns. The genus Lithomelissa, containing numerous and widely distributed forms, may like Dictyophimus be regarded as one of the most primitive and ancient forms of Dicyrtida. It differs from the latter by the lateral (not terminal) position of the three thoracic feet, and may be derived either from Dictyophimus (by secondary development of intrapedal network towards the mouth, on the inside of the three feet) or directly from Tripo- spyris by similar formation of thoracic network beyond the collar stricture, outside the base of the three divergent feet and pierced by the latter. As the species of this genus are numerous, it may perhaps be better to divide it into two or three genera : Acromelissa, with a single horn, Micromelissa, with two horns, and SethomeUssa, with three or more horns. Subgenus 1. Acromelissa, Haeckel, 1881, Prodromus, p. 431. Definition. — Cephalis with a single occipital horn. 1 Lithomelissa = Stone bee ; f^itlci;, ixi'Maaa. 1204 THE VOYAGE OF H.M.S. CHALLENGER. 1. Lithomelissa macroptera, Ehrenberg. Lifhomelissa macroptera, Ehrenberg, 1875, Abhandl. J. k. Akad. d. Wiss. Berlin, p.78, Taf. iii. figs. 9, 10. ■ Shell smooth, with distinct collar stricture. Eelative length of the two joints = 4:5, breadth = 3:4. Cephalis ovate, with a stout, excentric, vertical, pyramidal horn of the same length. Thorax little larger, ovate, truncate. Both joints with very small and scattered pores. Three divergent ribs arise from the base of the cephalic horn, and are prolonged over the major part of the thorax ; their under free part arises from the middle part of the thorax and is as long as the horn, straight, pyramidal. Mouth truncate, little constricted. Dimensions. — Cephalis 0'04 long, 0"03 broad; thorax 0'05 long, 0'04 broad. Habitat. — Fossil in Barbados. 2. Lithomelissa ehrenbergii, Biitschli. Lithomelissa ehrenbergii, Biitsclili, 1882, Zeitschr. f. wiss. Zoo!., vol. xxxvi. p. 517, Taf. xxxiii. fig. 21a, b. Lithomelissa macroptera, var., Ehrenberg, 1875, Abhandl. J. k. Akad. d, Wiss. Beilin, p. 78, Taf. iii. fig. 8. (?) Lophophxna capito, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. viii. fig. 6. (?) Lophopihsena galeata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. viii. fig. 12. Shell rough, with distinct collar stricture. Relative length of the two joints = 4:2, breadth = 3:4. Cephalis ovate, with a stout excentric, oblique, pyramidal horn of half the length. Thorax little shorter, truncate, conical. Both joints with regular circular pores, of the same breadth as the bars. Three divergent conical feet, as long as the cephaUs, arise below the collar stricture. Mouth truncate, not constricted. Dimensions. — Cephalis 0'08 long, 0'06 broad ; thorax 0-04 long, O^OS broad. Habitat. — Central Pacific, Station 265, depth 2900 fathoms ; fossil in Barbados. 3. Lithomelissa macroceras, n. sp. Shell spiny, with sharp collar stricture. Relative length of the two joints = 5:7, breadth = 5:6. Cephalis spherical, with a large pyramidal horn of twice the length. Thorax little longer, ovate, truncate. Both joints with regular circular pores, three times as broad as the bars. Three divergent pyramidal feet, twice as long as the cephalis, arise from the middle part of the thorax. Mouth constricted, half as broad as the thorax. Dimensions. — Cephalis 0-05 long, 0-05 broad ; thorax 0-07 long, Q-QB broad. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 4. Lithomelissa mitra, Biitschli. Lithomelissa mitra, Biitschli, 1881, Zeitschr. f. wiss. ZooL, p. 518, Taf. xxxiii. fig. 24. Shell smooth, with distinct collar stricture. Relative length of the two joints = 5:4, breadth = 4:5. Cephalis ovate, with a slender, straight, vertical, pyramidal horn of the same length. Thorax ovate. REPORT ON THE RA.DIOLARIA. 1205 truncate, of about the same size. Both joints with very small and numerous pores, as broad as the bars. Three feet arising from the middle part of the thorax, very small, rudimentary, pyramidal, about as long as broad. Mouth truncate, little constricted. Dimensions. — Cephalis 0-05 long, 004 broad ; thorax 0-04 long, 0-05 broad. Habitat. — Fossil in Barbados. 5. Lithomelissa pycnoptera, n. s\). Shell rough, papillate, with slight collar stricture. Eelative length of the two joints = 1:3, breadth = 1:3. Cephalis small, hemispherical, with very small pores and a slender, straight, conical horn of twice the length. Thorax subconical, with regvdar circular, hexagonally framed pores, as broad as the bars. From its lower half arise three divergent, very strong feet, pyramidal, as long as the thorax, and three times as long as broad. Dimensions. — Cephalis 0'03 diameter, thorax 01 diameter. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 6. Lithomelissa microstoma, n. sp. Shell papillate, with slight collar stricture. Pielative length of the two joints =1:5, breadth =1:5. Cephalis small, hemispherical, with a conical horn of twice the length. Thorax subspherical, with subregular circular pores, three times as broad as the bars. From its middle part arise three divergent, stout, conical feet, of half the length, and twice as long as broad. Mouth small, strongly constricted, one-fourth to one-third as broad as the thorax. Dimensions. — Cephalis 0'03 long, 0'04 broad ; thorax 015 diameter. Habitat. — Fossil in Barbados. 7. Lithomelissa amphora, Stohr. Lithomelissa amphora, Stohr, 1880, Palseontograph, vol. xxvi. p. 100, Taf. iii. fig. 11. Shell smooth, with sharp collar stricture. Eelative length of the two joints = 1:5, breadth = 2:4. Cephalis small, hemispherical, with a cervical horn of the same length. Thorax ovate, with small regular circular pores, twice as broad as the bars. From its upper half arise three divergent, slender, conical feet, only one-fourth as long. Mouth constricted, with a hyaUne peristome, half as broad as the thorax. Dimensions. — Cephalis 0013 long, 0'026 broad; thorax 0'063 long, 0'053 broad. Habitat. — Fossil in tertiary rocks of Sicily ; Grotte (Stohr). Subgenu.s 2. Micromelissa, Haeckel, 1881, Prodromus, p. 433 {sensu emendato). Definition. — Cephalis with two divergent horns, a superior occipital horn and an inferior frontal horn. 1206 THE VOYAGE OF H.M.S. CHALLENGER. 8. Lithomelissa thoracites, Haeckel. LitliumeUssa fhomrites, Haeckel, 1862, Monogr. d. Radiol., p. 301, Taf. vi. figs. 2-8. Lithniiidiasa thoracites, R Hertvvig, 1879, Organism, d. Radiol., p. 76, Taf. viii. fig. 1. Shell smooth, with deep collar .stricture. Cephalis ovate, with two divergent, slender, conical horns, of about half the length ; a major oblique occipital horn on the posterior face, and a minor, nearly horizontal horn above the collar stricture, on the anterior face. Thorax about as large as the cephalis, truncate, ovate. Pores of both joints irregular, roundish, of different sizes. From the upper half of the thorax, below the collar stricture, there arise three slender, conical divergent feet, about as long as the cephalis. Mouth truncate, wide open, not constricted. On the numerous varieties of this common species compare my Monograph, on the structure of the ovate central capsule (enclosed in the cephalis), Hertwig, loc. cit. Dimensions. — Cephalis 0-05 to 0-06 long, 0-04 to O'OS broad ; thorax O'OS to 0-05 long, 0-05 to 0-07 broad. Hahitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface. 9. Lithomelissa mediterranea, J. Miiller. Lithomelissa mediteiTanea, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 4.5, Taf. vi. fig. 11. Lithomelissa mediterranea, Haeckel, 1862, Monogr. d. Radiol., p. 302. Shell smooth, with sharp collar stricture. Relative length of the two joints = 4:5, breadth = 4 : 5. Cephalis campanulate, conical, with two divergent small conical horns, a major occipital subvertical horn near the summit, and a minor sub-horizontal frontal horn near the collar stricture. Thorax truncate, ovate, little larger than the cephalis. From its lower part there arise three short conical, divergent feet, scarcely half as long as the cephalis (in Miiller's figure one of them is seen shortened, opposite to the frontal horn). Pores irregular, roundisli, much smaller in the cephalis than in the thorax. Mouth wide open, not constricted. Dimensions. — Cephalis 0'04 diameter, thorax 0"0.5 diameter. Habitat. — Mediterranean (French shore), J. Miiller, surface. 10. Lithomelissa hicornis, Ehrenberg. Lithomelissa hicornis, Ehrenberg, 1872, Ahliandl. d. k. Akad. d. Wiss. Berlin, p. 297, Taf. ii. fig. 7. Shell smooth, with deep collar stricture. Eelative length of the two joints = 1:3, breadtli = 1:2. Cephalis hemispherical, with two divergent, stout and straight, pyramidal horns ; a lai'ger occipital horn sub-vertical near the summit, and a smaller oblique frontal horn near the collar stricture. Thorax subspherical, twice as large, with larger irregular, roundish pores. From its lower half there arise three divergent curved pyramidal feet of about the same length. Mouth constricted, only one- third as broad as the thorax. Dimensions. — Cephalis 0'02 long, 0'03 broad ; tliorax 0-06 diameter. Habitat. — Atlantic, Stations 348 to 353, surface. REPORT ON THE RADIOLARIA. 1207 11. Lithomelissa haeckelii, Biitschli. LHhomelissa haeckelii, Butschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 517, Taf. xxxiii. fig. 23, a, b. Shell rough, with sharp collar stricture. Eelative length of the two joints = 6:5, breaclth = 6:7. Cephalis subspherical, large, with two divergent horns, a very large, obUque pyramidal occipital horn on the summit, and a very small frontal horn on the middle of the forehead. Thorax campanulate, little larger than the cephalis, with regular circular pores of twice the breadth. From the upper part of the thorax, below the collar stricture, there arise three stout, divergent, angular, semi-lunar feet, about as long as the shell. Mouth wide open, not constricted. Dimensions. — Cephalis O'OG long, 0'06 broad ; thorax 0'05 long, 0-07 broad. Ealitat. — Tropical Atlantic, Station 347, depth 2250 fathoms; fossil in Barbados. 12. Lithomelissa hiltschlii, n. sp. (PI. 56, fig. 1). Shell smooth, with slight collar stricture. Eelative length of the two joints = 5:6, breadth = 4:5. Cephalis ovate, large, with two small conical horns, which are opposed nearly horizontally, in the upper part of the cephalis ; an anterior frontal and a posterior occipital horn. Thorax ovate, truncate, little larger. Pores of l)oth joints irregular, roundish, of very different sizes. From the middle part of the thorax there arise three short conical divergent feet. (In the figured specimen there were some accessory thorns ; in another specimen, found afterwards, the surface was quite smooth, but the two horns and the three feet much larger, half as long as the cephalis.) Dimensions. — Cephalis 0-05 long, 0-04 broad; 006 long, 0'05 broad. Habitat. — Central Pacific, Stations 266 to 274, depth 2350 to 2925 fathoms. Subgenus 3. Sethomelissa, Haeckel, 1881, Prodromus, p. 431. Definition. — Cephalis with three, four, or more horns, a primary occipital, a secondary frontal, and one or more accessory parietal horns. 13. Lithomelissa corythium, Ehrenberg. Lithomelissa corythium, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iii. fig. 12. Shell smooth, with slight collar stricture. Eelative length of the two joints = 4:3, breadth = 4:5. Cephalis campanulate, with three short conical horns on the summit. Thorax flat and wide. Prom its upper part below the collar stricture, there arise three divergent, pyramidal feet, fenestrated at the base, about as long as the shell. Mouth wide open. (The specimen figured by Ehrenberg was an incomplete one.) DiTnensions. — Cephalis 0'04 in diameter, thorax O^OS long, O'Oo broad. Habitat. — Central Pacific, Station 268, depth 2900 fathoms ; fossil in Barbados. 1208 THE VOYAGE OF H.M.S. CHALLENGER. 14. Lithomelissa decacantha, n. sp. (PI. 56, fig. 2). Sethomelissa decacantha, Haeckel, 1881, Prodromus et Atlas. Shell smooth, with deep collar stricture, and with ten prismatic spines of nearly equal size and similar form. Eelative length and breadth of the two joints about equal. Cephalis ovate, in the upper half hyalme, in the lower half with few scattered pores ; in the equator with four prismatic horns of the same length, which diverge upwards ; three of them are placed in the same meridional planes as the three wings and the three feet of the thorax (one occipital and two parietal); the fourth (frontal) horn is opposed to the occipital. Thorax campanulate, three-edged, with three vertical prominent feet (directed downward) and three horizontal wings, arising from their knees. Mouth wide open, not constricted. Dimensions. — CephaUs 0'05 diameter ; thorax 0-05 long, 0'06 broad. Habitat. — Equatorial Atlantic, Station 347, surface. Genus 538. Psilomelissa,^ Haeckel, 1881, Prodromus, p. 431. Definition. — Sethopilida (vel Dicyrtida triradiata aperta) with three free lateral wings, or solid spines arising from the sides of the thorax. No terminal feet. Cephalis smooth, without a horn. The genus Psilomclissa has the same formation of the shell as the nearly allied preceding genus Lithomelissa, and may be derived from it by reduction and loss of the cephalic horn. The cephalis is quite bare. 1. Psilomelissa galeata, Haeckel. Dictyoeeplialtts galeatus, Ehrenberg, 1872, Aljhandl. d. k. Akad. d. Wiss. Barlin, p. 289, Taf. vii. fig. 25. Shell smooth, with sharp collar stricture. Eelative length of the two joints = 5:3, breadth =4:5. Cephalis ovate, with numerous irregular, roundish pores. Thorax truncate, conical, with a few small pores. From its upper part (below the collar stricture) there arise three thin, bristle-shaped, widely divergent wings, about as long as the cephalis. Mouth widely open. Dimensions. — Cephalis 0'05 long, 0'04 broad ; thorax O'OS long, 0'05 broad. Habitat. — Western Tropical Pacific, Stations 200 to 225, surface. 2. Psilomelissa phalacra, n. sp. Shell smooth, with deep coUar stricture. Eelative length of the two joints = 5:6, breadth = 4:4. Cephalis ovate, hyaline, with few small pores only in the lower third. Thorax cylindrical, truncate, with small irregular, roundish pores. From its upper third there arise below the stricture three club- ' Psilomelissa = Smootli bee ; •^I'Koi, /ii^icaa. REPORT ON THE RADIOLARIA. 1209 shaped, nearly liorizoutally divergent wings, as long as the thorax. The cephalis and the three feet are similar to those of Pcromdissa i:i}mlacra, (PI. 57, fig. 11); but the cylindrical thorax with irregularly scattered pores is completely different, and exhibits a truncate, wide open mouth. Dimensions. — Cephalis 0-05 long, 0'04 broad ; thorax 0-06 long, 0'04 broad. Eahitat. — North Pacific, Station 244, depth 2900 fathoms. 3. Psilomelissa hertwigii, Haeckel. Lithomelissa hertwigii, Biitschli, 1882, Zeitschr. f. wiss. Zool., p. 517, Tcaf. xxxiii. iig. 22, a, h. Shell rough, with obliterated collar stricture. Length of the two joints = 4:4, breadth = 5:5. Cephalis hemispherical. Thorax little larger, cylindrical. From its upper half there arise three very strong pyramidal divergent wings, about as long as the shell. Pores of both joints very small and numerous, circular. Mouth truncate, wide open. Dimensions. — Cephalis 0-04 long, 0-05 broad ; thorax 0-04 long, 0-05 broad. Habitat. — Fossil in Barbados. 4. Psilomelissa calvata, u. sp. (PL 56, fig. 3). Shell smooth, with sharp collar stricture. Length of the two joints = 7:5, breadth = 5:6. Cephahs ovate, large, with subregular, circular, double-contoured pores. Thorax smaller, ovate, with very irregular, roundish pores of different sizes. From its upper third there arise three conical, slender, widely divergent spines or wings of the same length. (In fig. 3 the cephalis with the three wings is alone represented.) Dimensions. — Cephalis 0-07 long, 0*05 broad ; thorax 0-05 long, 0-06 broad. Habitat. — Central Pacific, Stations 263 to 274, depth 2350 to 2925 fathoms. 5. Psilomelissa sphwrocephala, n. sp. Shell rough, with deep collar stricture. Length of the two joints = 1:2, breadth = 1:3. Cephalis spherical. Thorax cap-shaped, flat and broad. From its upper half there arise three pyra- midal wings, half as long, fenestrated at the base and nearly horizontally divergent. Mouth con- stricted, half as broad as the thorax. Dimensions. — Cephalis 0'03 diameter; thorax 0'06 long, 0-09 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. Genus 539. Sponxjomelissa,^ n. gen. Definition. — S e t h o p i 1 i d a (vel Dicyrticla triradiata aperta) with three free lateral wings, or solid spines arising from the sides of the thorax. No terminal feet. Cephalis with one or more horns. * /Spon(707?i«Zissa= Spongy bee ; uTti'/yoi, fisKwam. (ZOOL. CHALL. EXP. — PART XL. — 1886). Rr 152 1210 THE VOYAGE OF H.M.S. CHALLENGEE. The genus Spongomelissa differs from its ancestral genus Lithomelissa only in the development of spongy framework in the shell-wall — a very rare production in the Cy rtoidea (compare Peripyramis, p. 1162, and Spongocyrtis, p. 1188). 1. Spongomelissa spongiosa, Haeckel. Lithomelissa spongiosa, Biitsclili, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. pp. 519, 539, Taf. xxxiii. fig. 25, a, b, c. Shell of dense spongy structure, with a deep collar stricture. The subspherical cephalis and the truncate abdomen of nearly equal size, both with irregular delicate spongy framework. Mouth wide open. Cephalis with a large vertical apical and a small oblique frontal horn. Thorax with three very stout, three-sided prismatic widely divergent lateral wings, which are covered with numerous irregularly ramified branches ; the spongy framework arises hy communication of the dehcate branches. Dimensions. — Cephalis O'Ol: long, O'Oo broad, thorax 0'04 long, 0'06 broad. Habitat. — Fossil in Barbados. Genus 540. Clathrocanium,^ Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 829. Definition. — S e t h o p i 1 i d a (vel Dicyrtida triradiata aperta) with three prominent lateral ribs on the thorax, alternating with three large holes (or thoracic gates). Cephalis with a horn. The genus Clathrocanium is nearly allied to Dictyophimus and Lithomelissa, and, together with these two genera, may be regarded as surviving representatives of the oldest and most primitive forms of Dicyrtida. It differs from the latter mainly in the incomplete fenestration of the sheU, three large interradial holes remaining between the three perradial thoracic ribs. It may therefore be derived either from Eusceniuni or from Tripospyris by the development of a terminal lattice-band between the three feet. Clathrocanium may be divided into two different subgenera : Clathrocanidium, with simple horn and smooth mouth, and Clathrocorona, with fenestrated horn and coronated mouth. Subgenus 1. Clathrocanidium, Haeckel. Definition — Horn of the cephalis simple, not fenestrated. Peristome smooth. 1 Ctot/irocciiwMm = Basket of network ; xXij^^a, x.»vtoii. REPORT ON THE RADIOLARIA. 1211 1. Clathrocanium squarrosum, Ehrenberg. Clathrocanium sqiMrromm, Ehrenberg, 1872, Abhandl. d. k. AkaJ. d. Wiss. Berlin, p. 287, Taf. vii. fig. 5. Cephalis campanulate, with irregular roundish pores and a pyramidal horn of the same length, bearing at the apex three short branches. Length of the two joints 2 : 3, breadth = 2:6. Thorax with three simple, prismatic, thin ribs, which are twice as long as the cephalis, separated by large triangular holes and connected only at the distal end by a small triangular ring of delicate lattice- work. Peristome smooth, wide, as broad as the thorax. Dimensions. — Cephalis 0-04, long, 0'04 broad ; thorax 0-OG long, 012 broad. Habitat. — Western Tropical Pacific (Philippine Sea), depth 3300 fathoms. 2. Clathrocanium sphceroceplialum, n. sp. (PL 64, fig. 1). Cephalis spherical, with regular circular pores and a prismatic horn of the same length, with three serrated edges. Length of the two joints = 2:3, breadth 2 : 4. Thorax with three broad, triangular, latticed, divergent ribs, which are separated by three large ovate holes (about as large as the cephalis), and connected at the distal end by a broad fenestrated circular ring of regular lattice-work (about six pores in its height). Peristome smooth, constricted, half as broad as the thorax. Dimensions. — Cephalis 0-04 long, 0-04 broad ; thorax O'OG long, O'OS broad. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 3. Clathrocanium coarctatum, Ehrenberg. Clathrocanium coarctatum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. vii. fig. 6. Lychnocanium fenesfratum, Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 767. Cephalis spherical, thorny, with regular circular pores and a simple pyramidal horn of the same length. Length of the two joints = 2:3, breadth = 2:5. Thorax with three simple, prismatic, little prominent ribs, which are separated by three large ovate holes (twice as long as the cephalis), and connected below the prominent distal end by a narrow circular ring of delicate lattice-work. Peristome smooth, wide, little narrower than the thorax. Dimensions. — Cephalis 0"03 long, 0-04 broad; thorax 0'06 long, 01 broad. Habitat. — Western Tropical Pacific (Philippine Sea), depth 3300 fathoms. 4. Clathrocanium triomma, n. sp. (PL 64, fig. 3). Cephalis spherical, thorny, with regular circular pores, and a slender prismatic horn of twice the length, bearing at its apex three short recurved branches. Length of the two joints = 2:4, breadth = 2:5. Thorax with three broad prismatic, fenestrated ribs, which are separated by three large sub- 1212 THE VOYAGE OF H.M.S. CHALLENGER. circiilar holes, and below the prominent distal end by a broad, triangular, roundish ring of subregular lattice-work (with square pores). Peristome smooth, about half as broad as the thorax Dimensions. — Cephalis 0-04 long, 0-04 broad; thorax 0-08 long, Ol broad. Rahitat. — Central Pacific, Station 272, depth 2600 fathoms. Subgenus 2. Clathrocorona, Haeckel, 1881, Prodromus, p. 431. Definition. — Horn of the cephalis fenestrated. Peristome on the margin of the basal mouth with a corona of sj)ines. 5. Clathrocanium diadema, n. sp. (PL 64, fig. 2). Clathrocorona diadema, Haeckel, 1881, Prodromus, p. 431. Cephalis hemispherical, thorny, with irregular roundish pores, and a large prismatic horn of twice the length, the three edges of which are denticulate and fenestrated, each with a series of square pores. Length of the two joints = 1:3, breadth = 2:4. Thorax thorny, with three broad fenestrated divergent ribs, which are separated by three large ovate holes (twice as long as the cephalis) and have their prominent distal ends connected below by a broad circular ring of lattice-work (with irregular polygonal small meshes). Peristome wide, two-thirds as broad as the thorax, with a circular corona of small square pores and alternating promuient small teeth. Dimensions. — Cephalis 0'03 long, 0'04 broad ; thorax 0'07 long, 0"09 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 6. Clathrocanium regince, n. sp. (PI. 64, fig. 4). Clathrocorona regince, Haeckel, 1881, Prodromus, p. 431. Cephalis hemispherical, with irregular roundish pores and a prismatic club-shaped horn of twice the length, the three edges of which are denticulate and fenestrated. Length of the two joints = 1:3, breadth = 1:4. Thorax thorny, with three broad triangular, fenestrated and nodulated ribs, which are separated by three large ovate holes (twice as long as the cephalis) and have their prominent distal ends connected below by a circular ring of lattice-work. Peristome constricted, as broad as the thorax, with a corona of short spines. DiTneniions. — Cephahs 0'03 long, 0'04 broad; thorax 0'08 long, 012 broad. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. Genus 541. Lamiorodiscus, Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 831. Definition. — S ethopilida (vel Dicyrtida triradiata aperta) with three divergent lateral ribs in the wall of the flat, conical, discoidal, or pyramidal thorax. Cephalis with a horn. Peristome smooth, %vithout corona of spines. ' ia?7ipro(iwciw = Spleudid disk ; 'haftw^os, licrxos. REPORT ON THE RADIOLARIA. 1218 The genus Lamjyrodisctts, ;uk1 the following neasrly allied Lampromitra, differ from till preceding Sethopilida in the complete connection of the three thoracic feet by lattice- work, so that they are imbedded in the thorax-wall as prominent ribs and are not prolonged beyond the margin as free feet. The shell is commonly very flat, conical or pyramidal, sometimes nearly discoidal. The margin of Lanvprodiscus is simple, smooth. 1. Lainprodisms monoceros, Ehrenberg. Lamprodiscua monoceros, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 295, Taf. vii. fig 2. Shell smooth, with deep collar stricture. Length of the two joints = 1:5, breadth —1:8 CephaHs spherical, hyaline, without pores, with an oblique conical horn of the same length. Thorax flat, campanulate, nearly hemispherical, with convex lateral outlines, and regular hexagonal meshes, increasing gradually in size towards the mouth. Bars very thin. Peristome smooth. Dimensions. — Cephalis 0'02 diameter ; thorax 01 long, 016 broad. Rahitat. — Western Tropical Pacific (Philippine Sea), Station 200, surface. 2. Lamprodiscus coscinodiscus, Ehrenberg. Lamprodiscm coscinodiscus, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 295, Taf. vii. fig. 3. Shell smooth, with sharp coUar stricture. Thorax of the same form and structure as in the preceding species, difl'ering from it mainly in the structure of the smooth circular margin, which is composed of a ring of very small square pores. Length of the two joints = 1:4, breadth =1:8. Cephalis with small hexagonal pores, without horn or with a short rudimentary horn. Lateral outlines of the campanulate thorax in the upper part concave, in the lower convex. Dimensions. — Cephalis 0'02 diameter ; thorax 0'08 long, 016 broad. Hahitat. — Tropical Pacific, Stations 206, 224, 266, &c., surface. 3. Lamprodiscus tricostatus, n. sp. Shell smooth, with deep collar stricture. Length of the two joints = 1:3, breadth = 1:7. Cephalis spherical, with an oblique conical horn of twice the length and small circular pores. Thorax flatly, conical, twice as broad as liigh, with straight lateral outline, and regular hexagonal meshes, increasing gradually in size towards the mouth ; bars very thin. Peristome or margin of the basal mouth circular, smooth. Very similar to Tlicopilimn tricostatum (PI. 70, fig. 6), but without abdomen. Differs from the two preceding species mainly in the conical form of the thorax and the less delicate network. Dimensions. — Cephalis 0'03 diameter; thorax 01 long, 0"2 broad. Habitat. — Cosmopolitan, Mediterranean, Atlantic, Indian Pacific ; surface. 1214 THE VOYAGE OF H.M.S. CHALLENGER. 4. Lamjyrodiscits Icevis, Haeckel. Eucecrijphalus lams, E. Hertwig, 1879, Organism, d. Radiol., p. 77, Taf. viii. figs. 6, 6a, 65. Shell .smooth, with distinct collar stricture. Length of the two joints = 1 : 3, breadth = 1 : 6. CephaUs subspherical, with small circular pores and an oblique conical horn of twice the length. Thorax flat, pyramidal, twice as broad as long, with three strong, straight divergent edges and subregular roundish pores. Peristome smooth. Dimensions. — Cephalis 0'025 diameter; thorax 0'08 long, 0-16 broad. Habitat. — Mediterranean (Messina), E. Hertwig, surface. Genus 542. Lampro7nitra, Haeckel,^ 1881, Prodromus, p. 431. Definition. — S e t h o p i 1 i cl a (vel Dicyrtida triradiata aperta) with three divergent lateral ribs in the wall of the flat conical or pyramidal thorax. Cephalis commonly with a horn. Peristome with a corona of spines. The genus Lampromitra difl'ers from the preceding and nearly allied Lamprodiscus only in the development of a dentated peristome, or an elegant corona of teeth around the wide open mouth. It bears therefore to the latter the same relation that Clathrocorona does to Clathrocanium. 1. Lampromitra coronata, n. sp. (PI. 60, fig. 7, 7a). Shell flat, conical, with slight collar stricture. Length of the two joints = 1:2, breadth = 2:7. Cephalis hemispherical, with a conical oblique horn of twice the length, and small subregular hexagonal pores. Thorax with larger, subregular, hexagonal meshes, six to eight times as broad as the bars. Peristome or basal margin of the thorax circular, with a marginal ring of smaller polygonal meshes and a triple coronal of short spines ; two external rings of short conical centrifugal spines, and an internal ring of thin centripetal rods (fig. 7«). In fig. 7 the shell is seen from below and exhibits very distinctly the internal cross of the collar septum, composed of the four divergent cortinar bars ; between the latter descend the four pear-shaped lobes of the central capsule (each containing an oil globule), whilst the apical part of the capsule (with the nucleus) is hidden in the large cap-shaped cephalis. Dimensions. — Cephalis O'OS long, 0'07 broad ; thorax 0-06 long, 0-2 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 2. Lampromitra quadricuspis (PI. 58, fig. 7). Shell flat, conical, with sharp collar stricture. Length of the two joints =1 : 3, breadth = 2 : 10. Cephalis hemispherical, with subregular circular pores and an oblique, conical, occipital horn of twice ' La?ftp?-omiira= Splendid turban; 7i«/«w;oV, fV? «• REPORT ON THE RADIOLARIA. 1215 the length, bearing three divergent lateral liranches, which are directed upwards, and correspond to the three thoracic ribs. Further down, near the collar stricture, a short divergent frontal horn arises. Thorax with irregular roundish pores of different sizes, three to six times as broad as the bars. Peristome with a simple coronal of short, conical, divergent spines, about as long as the diameter of the cephalis. Dimensions. — Cephalis 0'02 long, O'Oi broad ; thorax O'OG long, 0'2 broad. Hahitat. — North Atlantic, Canary Islands, surface. 3. Lampromitra furcata, n. sp. (PI. 58, fig. 8). Shell flat, conical, with deep collar stricture, very similar in furm and structure to the preced- ing species ; differs from it in the shape of the peristome and the armature of the cej)halis, which bears a conical, forked, occipital horn of the same length, and a small rudimentary divergent frontal horn. Length of the two joints = 1:2, breadth = 1 : G. Tlie four pores of the collar septum (two larger cardinal and two smaller jugular) exhibit in this species a peculiar asymmetry (fig. 8). The peristome bears a simple coronal of spines as long as the diameter of the cephalis. The major part of them is forked, some irregularly branched. Dimensions. — Cephalis 0'02 long, 0'03 broad; thorax O'OG long, 0'18 broad. Hahitat. — South Pacific, Station 298, depth 2225 fathoms. 4. Lampromitra pyramidalis, n. sj). Shell flat, pyramidal, smooth, with slight collar stricture. Length of the two joints = 1:4, breadth = 1:9. Cephalis subspherical, with an oljlique pyramidal horn of twice the length, and small circular pores. Thorax with three strong, divei'gent, straight ribs and three flat triangidar sides between them, with subregular hexagonal pores, increasing in size towards the mouth. Peristome with a simple coronal of large and numerous divergent, conical spines, half as long as the shell. Dimensions. — Cephalis 0'02 long, 0-02 broad ; thorax 0'09 long, 0"18 broad. Hahitat. — South Atlantic, Station 325, depth 2650 fathoms. 5. Lampromitra huxleyi, Haeckel (PI. 59, fig. 1). Eucecryphalus huxleyi, Haeckel, 1879, Natiirl. Schopfungsgesch., Edit. vii. Taf. xvi. fig. 9. Shell flat, conical, spiny, with slight collar stricture. Length of the two joints = 1:3, breadth = 1:8. Cephalis hemispherical, with a short conical horn of the same length. Thorax with irregular polygonal pores. Peristome with three coronals of divergent bristle-shaped spines ; the first directed obliquely upwards, the second outwards, and the third nearly vertically, downwards ; the Ijristles of the latter are much longer, about as long as the height of the shell. Dimensions.- — Cephalis 0'02 long, 0'02 broad; thorax OOG long, 0"16 broad. Hahitat. — Australia (east coast), Station 169, surface. 1216 . THE VOYAGE OF H.M.S. CHALLENGER. 6. Lampromitiu schultzei, Haeckel. Eucearyphalus sehultzei, Haeckel, 1862, Monogr. d. Kadiol., p. 309, Taf. v. figs. 16-19. Shell flat, conical, smooth, with slight collar stricture. Length of the two joints = 1:3, breadth = 1:8. Cephalis hemispherical, with a small conical horn of half the length, and very small roundish pores. Thorax with three strong, straight ribs and irregular polygonal pores, which are much larger in the middle part than in the upper or lower part. Peristome with a double coronal of short, conical, divergent spines; the superior obliquely ascending, the inferior vertically descending. (Named in honour of the late Professor Max Schultze, the illustrious histologist.) Dimensions. — Cephalis 0'025 diameter; thorax 0"07 long, 0'2 broad. Hahitat. — Mediterranean, Messina, surface. 7. Lampromitra arboresce?is, n. sp, (PL 60, fig. 8, 8a). Shell flat, pyramidal, spiny, with sharp collar stricture. Length of the two joints = 1:3, breadth = 2 : 10. Cephalis cap-shaped, with an oblique, slender, conical horn of twice the length, and small circular pores. Thorax with three slight almost obliterated ribs and three vaulted sides between them, with irregular roundish pores. The three ribs are distinct in the proximal, not in the distal part. Peristome with a double coronal of smaller squarish pores and numerous divergent spines ; the larger spines are irregularly branched and as long as the diameter of the cephalis. Dimensions. — Cephalis 0'15 long, 0-03 broad ; thorax 0'04 long, 0-2 broad. Hahitat.— Imlian Ocean, Madagascar (Eabbe), surface. 8. Lampromitra dendrocorona, n. sp. (PI. 58, fig. 9). Shell flat, conical, with smooth surface and deep collar stricture. Length of the two joints = 1:4, breadth = 2 : 10. Cephalis hemispherical, with a slender occipital horn of three times the length, and a small divergent frontal horn. Thorax with three strong, prominent, straight ribs and irregular polygonal meshes, increasing in size towards the mouth. Peristome with a dense coronal of numerous short conical spines and twenty-four to thirty larger arborescent spines, longer than the diameter of the cephalis. Dimensions. — Cephalis 0'02 long, 0"04 broad; thorax 0'08 long, 0'2 broad. Hahitat. — Central Pacific, Station 272, depth 2600 fathoms. Genus 543. Callimitra} Haeckel, Prodromus, 1881, p. 431. Definition. — S e t h o p i 1 i d a (vel Dicyrtida triradiata aperta) with three vertical latticed wings, which stretch between the three divergent lateral ribs of the thorax and the vertical horn of the cephalis. No frontal horn. 1 CaMtmitra = Beautiful turban ; koKkI;, ^iVja. EEPORT ON THE RADIOLARIA. 1217 The genus Callimitra, aud the two following nearly allied genera, Clathromitra and Clathrocorys, form together a peculiar small group, the Callimitrida, living in the Central Pacific, aud differing from the other Sethopilida in some remarkable points, derived perhaps directly from the Ai'chiscenida, Archiscenmm and Pteroscenium, by the development of thoracic network between the three cortiuar feet. In the centre of the collar septum, where these feet are united, there arises a vertical free columella, prolonged over the top of the cephalis as a free horn, aud this horn is connected with the three thoracic ribs by three vertical fenestrated wings. 1. Callimitra carolotce, n. sj). (PI. 63, figs. 1, 7, 8). Cephalis campanulate, conical, with irregular, polygonal pores, and a thin bristle-shaped apical horn of the same length. Length of the two joints = 3 : 6, breadth = 2 : 6. Thorax in the upper half with irregular network, in the lower half with parallel transverse bars ; in each of its three sides descend two convergent pairs of stronger, parallel, curved ribs, not confluent at the peristome. Each of the three vertical wings with eight stronger ribs, three arising from the cephalis, five from each foot. Dedicated to my dear mother Charlotte Sethe. Dimensions. — Cephalis 0-07 long, 0-05 broad; thorax 015 long, O'lo broad. Habitat. — Central Pacific, Station 270, depth 2925 fathoms. 2. Callimitra anna;, n. sp. (PI. 63, fig. 2). Cephalis campanulate, conical, with irregular, polygonal pores, and a thin bristle-shaped horn of the same length. Length of the two joints = 1:2, breadth = 1:3. ThoraLx nearly in its whole extent with parallel transverse bars, which are crossed by two convergent systems of parallel beams ; in each of its three sides descend four convergent pairs of stronger, parallel, curved ribs, not coniiuent at the peristome. Each of the tlu-ee vertical wings with six stronger ribs, three arising from the cephaUs, three from each foot. Dedicated to my dear first wife Anna Sethe. Dimensions. — Cephalis 0-05 long, 0-05 broad ; thorax 012 long, 018 broad. Habitat. — Central Pacific, Station 271, depth 2125 fathoms. 3. Callimitra agnesce, n. sp. (PL 63, fig. 5). Cephalis pear-shaped, with irregular, square pores, aud a slender bristle-shaped horn twice as long. Length of the two joints = 1:3, breadth = 1:5. Thorax in its whole extent with parallel transverse bars, which are crossed by two converging and crossed systems of parallel beams ; in each of its three sides descend five convergent pairs of stronger, parallel, curved ribs, the two or three upper of which are crossed at the peristome. Each of the tliree vertical win^s with five stronger ribs, three arising from the cephalis and the horn, two from each foot. Dedicated to my dear second wife Agues Huschke. Dimensions. — Cephalis 0-05 long, 0-05 broad; thorax 015 long, 0'22 broad. Habitat. — Central Pacific, Station 273, depth 2350 fathoms. (200L. CHALL. EXP. PART XL. — 188G.) Er 153 1218 THE VOYAGE OF H.M.S. CHALLENGER. 4'. Ccdlimitra elisahethce, n. sp. (PL 63, fig. 6). Cephalis nearly hemispherical, with irregular, square pores, and a strong prismatic horn thrice the length. Length of the two joints = 2: 7, breadth = 2:9. Thorax in the upjier third with irregular network, in the lower two-thirds with parallel transverse bars, which are crossed by two convergent systems of parallel beams ; in each of its three sides descend three convergent pairs of stronger, parallel, curved ribs ; the two ribs of the uppermost pair are united and confluent in a single odd rib in tlie lower half of tlie thorax. Each of the three vertical wings with seven stronger ribs, three arising from the cephalis and the horn, four from each foot. Dedicated to my dear elder daughter Elizabeth Haeckel. Dimensions. — Cephalis 0'04 long, 0'05 broad; thorax 015 long, 0'2 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 5. Callimitra emmce, n. sp. (PL 63, figs. 3, 4). Cephalis campanulate, with irregular, polygonal pores, and very thin bars (of the same* shape as in the thorax) and with a thin bristle-shaped horn twice the length. Length of the three joints = 3:6, breadth = 2:9. Thorax in its whole extent with an arachnoidal network, similar to that in the cephalis and the three wings, composed of very numerous parallel threads, which are crossed by two crossed diagonal systems of parallel threads. In each of the three sides of the thorax descend five convergent pairs of stronger ribs, the three upper of which are crossed and form large rhomboidal meshes. Each of the three vertical wings with ten stronger ribs, four arising from the cephalis and each horn, six from each foot. Dedicated to my dear younger daughter Emma Haeckel. Dimcnsio7is. — Cephalis 0-07 long, 0'06 broad ; thorax 015 long, 0'22 broad. HaUtat.^Central Pacific, Station 274, depth 2750 fathoms. Geuus 544. Clathromitra,^ Haeckel, 1881, Prodromus, p. 432. Definition. — S e t h o p i 1 i d a (vel Dicyrtida triradiata aperta) with three vertical latticed wings, which stretch between the three divergent lateral ribs of the thorax and the vertical horn of the cephalis. The front of the latter is armed with a large frontal horn. The genus Clathromitra differs from the preceding similar Callimitra in the develop- ment of a free frontal or sternal horn, a prolongation of an internal obliquely ascending rod, opposite to the caudal foot. Therefore the shell in this genus possesses five divergent free spines, two cephalic horns, and three thoracic feet. The lattice-work of the three vertical wings is not so delicate as in Callimitra. ^ Ctei/iromi(ra = Lattice-turban ; xTtijS^a., fiir^ct, REPORT ON THE RADIOL ARIA. 1219 1. CJathromitra pterophormis, u. sp. (PI. 57, fig. 8). Cephalis very large, hemispherical, about as long and half as broad as the three-sided pyramidal thorax ; both with irregular, polygonal meshes. Apical horn three to four times as long as the frontal horn and the three basal feet. All five spines three-sided prismatic, with nearly smooth edges. Three lateral wings half as broad as the cephalis. Dimensions. — Cephalis 0'05 long, 01 broad ; thorax 0'05 long, 0'15 broad. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 2. C/athromitra pentacantha, n. sp. Cephalis large, hemispherical, half as long as the three-sided pyramidal thorax ; both with irre- gular, roundish meshes. Apical horn of about the same length as tire frontal horn, and twice as long as the three basal feet, All five spines three-sided prismatic, with denticulated edges. Three lateral wings about as broad as the cephalis. Dimensions. — Cephalis 0'04 long, 0'08 broad ; thorax O'l long, 0'2 broad. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. Genus 545. Clathrocorys,^ Haeckel, 1881, Prodromus, p. 432. Definition. — Setliopilida (vel Dicyrtida triradiata aperta) with three promiuent lateral ribs on the thorax, alternating with three large holes (or thoracic gates). The three ribs are connected with the central apical horn of the cephalis by three vertical latticed wings. The genus Clathrocorys differs from the two preceding nearly allied genera in the incomplete fenestration of the thorax, the three perradial ribs of which are separated by three large interradial holes. It has therefore the same relation to Callimitra that Clathrocanium bears to Dictyophimus. 1. Clathrocorys murrayi, n. sp. (PI. 64, fig. 8). Cephahs pear-shaped, with irregularly square pores. From the centre of its base there arise four strong, prismatic, radial beams of nearly equal size, the vertical, straight, cephalic horn being little longer than the three divergent, somewhat curved feet. In the three meridional planes (between the horn and each foot) a few rather thick branches arise, which by communication of the ramules form the three vertical latticed wings ; eacli wing with two large meshes, three to five meshes of medium size, and three to four parallel arachnoidal rows of small, square, distal meshes. The three walls of the flat pyramidal tliorax (between every two feet) are formed in the upper part by squarish network 1 (/fofftrocoro/s = Lattice-heliuet ; x>ji6^x, k6^u;. 1220 THE VOYAGE OF H.M.S. CHALLENGER. similar to that of the cephalis, in the middle part hj a single row of arches separated by thin threads, and in the lower part l)y a narrow band of arachnoidal network. Dedicated to Dr. John Murray. Dimensions. — Cephalis 0'05 long, O'Oo broad ; thorax 0'0'04 long, 015 broad ; apical distance of every two feet 0"15, of each foot and the horn 0'17. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 2. Clathrocorys teuscheri, n. sp. (PL 64, fig. 10). Cephalis pear-shaped, with irregular, square pores. From the centre of its base there arise seven prismatic, radial beams of equal strength, supporting the lattice-work of the wall ; the single verti- cal beam is prolonged into the apical horn ; six others He in the three meridian planes (between the horn and each foot) ; three ascending end in the wall of the cephalis, three descending are prolonged into tlie three strong feet, which are longer than the horn. In each meridional plane there arise four tliieker and several thinner bars, which by communication of their ramides form the three latticed wings ; each wing with a single very large mesh, two meshes of medium size, and a narrow marginal band of small, square pores. The three walls of the flat pyramidal thorax are formed in the upper part by squarish network similar to that of the cephalis, in the lower part by a narrow band of the same ; between them a large hole. Dedicated to Dr. Eeinhold Teuscher. Divimsions. — Cephalis 0'05 long, 0"04 broad; thorax 0'06 long, 015 broad; apical distance of every two feet 0'2, of each foot and the horn 0'2. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 3. Clathrocorys giltschii, n. sp. (PI. 64, fig. 9). Cephalis pear-shaped, with irregular, polygonal pores. From the centre of its base there arise seven prismatic, radial beams of different strength ; the single vertical beam bears six lateral branches (parallel to the three ascending supporting beams), and is prolonged into the apical horn ; six others lie in the three meridional planes (between the horn and each foot) ; three weaker ascending beams end in the wall of the cephalis, three stronger descending are prolonged into the three large diver- ging feet, which are twice as long as the cephalic horn. The network of the three wings and of the three-sided pyramidal thorax is about the same as in the preceding species, but much more developed ; the marginal bands with the squarish network are much broader, and an arachnoidal wicker-work of very thin thread-lilve bars fills out the large meshes. Dedicated to Mr. Adolf Giltsch. Dimensions. — Cephalis 0-04 long, 0-04 broad ; thorax 012 long, 0^2 broad ; apical distance of every two feet 0-24, of each foot and the horn 0 2. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. Genus 546. Eucecryphalus,^ Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 836. Definition. — S e t k o p i 11 d a (vel Dicyrtida triradiata aperta) with three free collar ' Eucecryphaliis='i^ ice net-cap ; iv, y.tx.^iq>a>.oi. REPORT ON THE RADIOLARIA. 1221 wdngs or solid spines arising from tlie collar stricture, and freely prominent between the horned cephalis and the flat conical thorax. The genus Eucecryphalus, according to the restricted definition here given, com- prises only those Sethopilida in which the three primary cortinar beams are perfectly fi-ee divergent collar wings, i.e., free spines arising outside the shell from the coUar stricture, between the cephalis and thorax. The type of this genus (which I formerly united with other Sethopilida) remains Eucecryphalus gegenbauri. Subgenus 1. Eucyrtomphalv.s, Haeckel, 1881, Prodromus, p. 431. Definition. — Peristome or margin of the basal mouth of the thorax smooth,, without marginal spines. 1. Eucecryphalus corocalyptra, n. sp. SheU flatly conical, with slight coUar stricture. Length of the two joints = 1 ; 3, breadth = 1 : C. Cephalis subspherical, with an obhque conical horn twice its length. Thorax conical, twice as broad as long, with regular hexagonal meshes and straight lateral outlines. From the coUar stricture there arise three slender conical spines, about as long as the thorax, divergent downwards. Similar to Corocalyptra agmsce, (PL 59, fig. 3), but without lumbar stricture and abdomen. Peristome or basal margin of the mouth of the thorax smooth, simple. Dimensions. — Cephalis 0*03 diameter ; thorax 0'09 long, 0-18 broad. Habitat. — Cosmopohtan ; Atlantic, Indian, Pacific, surface. 2. Eucecryphalus halicalyptra, ix, sp. Shell flat, campanulate, with distinct coUar stricture. Length of the two joints =1 : 4, breadth; = 2:10. Cephalis hemispherical, with two divergent conical horns, a major occipital and a minor frontal horn. Thorax with subregular hexagonal meshes and concavo-convex lateral outlines, cam- panulata From the collar stricture there arise three divergent bristle-shaped spines, nearly horizontal, about half as long as the thorax. Peristome smooth, with a marginal coronal of small square pores. Bimensiom. — Cephalis 0-02 long, 0-04 broad ; thorax O'OS long, 0-2 broad. Habitat. — Central Pacific, Stations 266 to 274, surface. Subgenus 2. Eucecryphalium, Haeckel. ' Definition. — Peristome or mai-gin of the basal mouth of the thorax dentate, with-,- a coronal of marginal spines. 1222 THE VOYAGE OF H.M.S. CHALLENGER. 3. Eucecry2)fialus cuvieri, n. sp. Shell flatly conical, with slight collar stricture. Length of the two joints = 1:8, breadth = 2:10. Cephalis hemispherical, with an oblic|Tie pyramidal horn twice as long. Thorax with straight outlines and regular hexagonal meshes, increasing in size towards the mouth. From the collar stricture there arise three stout conical spines, half as long as the thorax, and diverging downwards. Peristome with a ring of small square pores and alternate conical divergent spines. Differs fi'om the similar Clathrocyclas alcmence (PL 59, fig. 6), mainly in the simple apical horn and the possessiou of the three collar fundamental spines. Dimensions. — Cephalis 002 long, 0'03 broad ; thorax 0'15 long, 0'2 broad. Habitat. — Tropical Atlantic, Station 342, depth 1445 fathoms. 4. Eucecryphalus mulleri, n. sp. Shell flatly campanulate, of nearly the same structure as and similar form to that of the preceding species. Differs from it mainly in the considerable size of the cephalic horn and the three collar spines, which are bristle-shajjed and longer than the shell. Length of the two joints =1 : 4, breadth = 2 : 8. The peristome bears a double marginal ring of divergent conical spines, the upper being directed upwards, the lower downwards. Dimensions — Cephalis 0'02 long, 0'04 broad ; thoi'ax O'OS long, 0'16 broad. Habitat. — North Pacific, Station 241, depth 2300 fathoms. . 5. Eucecryphalus gegenhauri, Haeckel. Eucecryphalus gegenhaui-i, Haeckel, 1862, jMonogr. d. Eadiol., p. 308, Taf. v. figs. 12-15. Eucecryphalus gegenhauri, R. Hertwig, 1879, Organism, d. Radiol., p. 76, Taf. viii. figs. ,'>, 5(7, bh. . Shell flatly conical, campanulate, with slight eoUar stricture. Length of the two joints = 1:4, breadth = 1:8. Cephalis hemisi^herical, with a conical horn of the same length, and very small pores. Thorax about twice as liroad as high, with large, subregular, hexagonal meshes, increasing in size downwards. In the upper half of the thorax the meshes are filled up by an extremely delicate arachnoidal network. From the collar stricture there arise three divergent bristle-shaped spines half as long as the thorax. Peristome with a double coronal of small square pores (the inner smaller and more numerous than the outer), and with a single coronal of divergent marginal spines. This cosmopolitan species is rather variable. Dimensions. — Cephalis 0'Q2 to 0'03 diameter; thorax O'l to 012 long, 002 to 025 broad. Habitat. — Cosmopolitan; Mediterranean,. Atlantic, Indian, Pacific, surface. REPORT ON THE RADIOLARIA. 1223 6. Euceci'yphalus campanella, HaeckeL Pterocodon campanella, Ehreuberg, 1875, Abhandl. d. k. Akacl. tl. Wiss. Berlin, p. 8"2, Taf. xix. fig. 2. Shell campanulate, conical, with sliarp collar stricture. Length of the two joiute=l:3, hreadth = 1:2. Cephalis hemispherical, with a short conical horn half as long, and very small pores. Thorax campanulate, as broad as high, with large roundish meshes, increasing in size downwards. From the coUar stricture arise three strong, divergent, somewhat curved spines, nearly as long as the thorax. Peristome with a coronal of ten to twelve strong, conical, marginal spines, which are nearly parallel, directed downwards, a little curved, and half as long as the thorax. In the complete specimen examined by me, the apical horn, the three lateral wings and twelve terminal feet were well preserved. Dimensions. — Cephalis 0'02 to 0"03 diameter; thorax 006 to 0'07 long and broad. Habitat. — Fossil in Barbados. Genus 547. AmpMj^lecta,^ Haeckel, 1881, Prodromus, p. 424. - Definition. — Sethopilida (vel Dicyrtida triradiata aperta) with three internal thoracic ribs, enveloped by the network of the thorax. Cephalis with a large aj^ical opening, surrounded by a coronal of spines. The genus Amp)hi2ylecta (or Amphicryphalus) comprises some very peculiar forms of Sethopilida, probably widelj^ remote from the other genera of this subfamily, and derived directl}" from the Plectanida (compare above, p. 921). The cortinar tripodium, composed •of thi-ee feet divergent downwards^ and one apical horn ascending upwards (in some species also a second frontal horn) is here enclosed in the cavity of a two-jointed shell, which exhibits two large openings, a smaller apical hole in the top of the cephalis, and a larger terminal mouth on the thor;ix. There is no trace of a sagittal ring. 1. Amphijplecta amp>hisloma, n. sp. Cephalis subspherical, spiny, with sharp collar stricture on the base ; its apical opening central, suiTOunded by a coronal of twelve to eighteen short spines. Length of the two joints = 7:8, breadth = 6 : 20. Thorax flatly conical, armed with bristle-shaped spines. Meshes of tlie network in both joints subregular, hexagonal, six to eight times as broad as the bars. Basal mouth bristly. Dimensions. — Cephalis 0^07 long, 0"06 broad ; thorax O"08 long, 0'2 broad Hahitat. — Central Pacific, Station 274, surface. 2. Amjjfiiplecta acrostoma, n. sp. (PL 97, fig. 10). Cephalis siibspherical, spiny, with distinct collar stricture on the base, its apical opening central, surrounded by a coronal of six to nine divergent denticulate spines. Length of the two joints = 5:6, '■ Amphiplecta = Shell at both poles open, with framework around; uj^tptic'hnKToi. 1224 THE VOYAGE OF H.M.S. CHALLENGER. Ijreadth = 4 : 15. Thorax flatly conical, armed with denticulate spines. Meshes of lioth joints irregular, polygonal, twice to six times as broad as the bars. Basal mouth armed with longer, divergent, denticulate spines, Bimcnsion-s. — CeiDhalis O'Oo long, 0-04 broad ; thorax O'OG long, OlS broad. .Habitat. — North Pacific, Station 244, depth 2900 fathoms. 3. AmpMplecta caUistoma, n. sp. (PL 59, fig. 2). Cephalis flat, cap-shaped, spiny, with obliterated collar stricture on the base ; its apical opening -excentric, oblique, surrounded by a coronal of ten to twenty bristle-shaped spines. Length of the •two joints = 4:5, breadth =: 7 : 25. Thorax flatly conical, armed with long bristle-shaped spines. Meshes of both joints irregular, hexagonal, twice to six times as broad as the bars. Basal mouth with a double irregular coronal of small square pores, and of bristle-shaped divergent spines. Dimensions — Cephalis 0-04 long, 0'07 broad ; thorax 0-05 long, 0-25 broad. Habitat. — Central Pacific, Station 271, surface. >Genus 548. Lychnocanium,^ Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Definition. — S e t h o p i 1 i d a (vel Dicyrtida triradiata aperta), witli three solid terminal feet on the peristome. No thoracic ribs. Cephalis with a horn. The gemis Lychnocanium, very rich i]i common living and fossil forms, comprises those Sethopilida in which the thorax bears three simple terminal feet around the mouth, but no lateral ribs in its wall. It has therefore been probably derived from Dictyojjhinms by reduction and loss of these three lateral ribs. The mouth is commonly more or less constricted. The three feet surrounding it are sometimes divergent, straight or curved, at other times parallel and vertical, straight, or curved and convergent. The central capsule exhibited in some living species, three or four distinct lobes, filling up the upper half of the thorax. Subgenus 1. Lychnocanella, Haeckel. Definition. — Feet divergent, straight or scarcely curved ; their terminal distance greater than their basal distance. 1. Lychnocanium lanterna, n. sp. (PI. 61, fig. 7). Shell conical, rough, with slight collar stricture. Length of the two joints = 1:3, breadth = 1:3. Cephalis with a stout pyramidal horn of the same length. Thorax pear-shaped, twice as ^ Lychnocanium = Lantern-basket ; ^is/x""?, '-■a^sou. EEPORT ON THE RADIOLARIA. 1225 broad as the constricted mouth, with regular, circular pores of the same breadth as the bars. Three feet pyramidal, little divergent, straight, about as long as the cephalis. Bime^isions. — Cephalis O'Oo long, 0'03 broad ; thorax O'OO long, 0-08 broad. Habitat. — Central Pacific, Stations 263 to 268, depth 2650 to 2900 fathoms. 2. Lychnocanium continuum, Ehrenberg. Lychnocanium continuum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. vii. fig. 11. Shell smooth, with distinct collar stricture. Length of the two joints = 1:3, breadth = 1:3. Cephalis subspherical with a conical horn of the same length. Thorax pear-shaped, twice as broad as the constricted mouth, nearly hyaUne, with a very small number of scattered mumte pores. Three feet pyramidal, little divergent, straight, about as long as the thorax. Diviensions. — Cephalis 0'02 long, 0'02 broad ; thorax 0'06 long, 0'06 broad. Habitat. — Fossil in Barbados. 3. Lychnocanium pyriforme, n. sp. (PL 61, fig. 11). Shell pear-shaped, rough, with sharp coUar stricture. Length of the two joints =1:4, breadth = 1:5. Cephalis hemispherical, with a conical horn of the same length. Thorax inflated, four times as broad as the constricted tubular mouth, with regular, circular pores. Three feet pyramidal, straight, divergent, about as long as the thorax. Dimensions. — Cephalis 0'02 long, 0'03 broad ; thorax 012 long, 015 broad. Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific, many Stations ; also fossil in Barbados. 4. Lychnocanium favosum, u. sp. (PL 61, fig. 6). Shell campanulate, rough, with slight collar stricture. Length of the two joints = 1:5, breadth = 1:6. Ceplialis hemispherical, with a rudimentary pyramidal horn of half the length. Tliorax subglobular, three times as broad as the constricted mouth, with regular, circular pores, and an elevated hexagonal framework between them. Three feet cylindrical, slender, straight, divergent, twice to three times as long as the thorax. Dimensions. — Cephalis 0'02 long, 0"025 broad ; thorax 01 long, 012 broad. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 5. Lychnocanium nodosum, n. sp. (PL 61, fig. 14). Shell campanulate, nodose, with deep collar stricture. Length of the two joints =1:3, breadtli = 1:4. Cephalis subglobular, with a rudmientary conical horn of half the length. Thorax nearly hemispherical, twice as broad as the fiat mouth, witli regular, circular pores, and a variable (ZOOL. CHALL. EXP. — PART XL. — 1886.) Rr 154 1226 THE VOYAGE OF H.M.S. CHALLENGER. number of scattered, conical, fenestrated protuberances. Three feet very large, prismatic, straight, divergent, twice as Ions; as the thorax. Dimensions. — Cephalis O'Co long, 0-04 broad ; thorax 0-09 long, 0-12 broad. Habitat.— Sovih. Pacific, Station 253, depth 3125 fathoms. 6. Lychnocanium carinatum, Elirenberg. Lyclmocanium carinatum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss, Berlin, p. 78, Taf. viii. fig. 5. Shell campanulate, with deep collar stricture. Length of the two joints = 1:3, breadth = 1:3. Cephalis subglobular, with a slender horn of the same length. Thorax conical, twice as broad as the flat mouth, with fifteen to twenty prominent, longitudinal, divergent ribs, alternating with the same number of rows of pores. Three feet slender, prismatic, straight, divergent, twice as long as the thorax. Dimensions. — Cephalis 0'02 long, 0'02 broad ; thorax O'OG long, 0-06 broadi Habitat. — Possil in Barbados. 7. Lychnocanium ventricosum, Ehrenberg. Lychnocanium ventricosum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Tat vii. fig. 12. Shell pear-shajjed, rough, with deep collar stricture. Length of the two joints =1:3, breadth = 1:4. Cephalis subglobular, with a stout conical horn twice the length. Thorax conical, three times as broad as the constricted mouth, with irregular, roundish pores of different sizes. Three feet stout, conical, divergent, half as long as the thorax. Dimensions. — Cephalis 0'02 long, 0'03 broad ; thorax 0'07 long, 0'09 broad. Hahitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms ; fossil in Barbados. 8. Lychnocanium trihulus, Ehrenberg, Lychnocanium trihulus, Ehrenberg, 1875, Abhandl d. k. Akad. d. Wiss. Berlin, p. 80, Taf. vii. fig. 1. Shell pear-shaped, nodose, with distinct collar stricture. Length of the two joints = 1:4 breadth =1:4. Cephalis subglobular, with a conical horn twice the length. Thorax ovate, twice as broad as the constricted mouth, with irregular, roundish pores of different sizes. Three stout feet strongly divergent, pyramidal, about as long as the thorax. Dimensions. — Cephalis 0-02 long, 0-02 broad ; O'OS long, 0-08 broad. Hahitat. — Fossil in Barbados. Subgenus 2. Lychnocanissa, Haeckel. Definition. — Feet divergent, more or less curved ; their terminal distance greater than their basal distance. REPORT ON THE RADIOL ARIA. 1227 9. Lychnocanium fortipes, n. sp. (PI. 61, fig. 12). Shell inflated, rough, with distinct collar stricture. Length of the two joints = 1 : 5, breadth = 1 : 6. Cephalis small, hemispherical, with a pyramidal horn of half the length. Thorax subglobular, truncate, twice as broad as the constricted mouth, with large, regular, circular pores and very thin bars. Three feet very stout, prismatic, twice as long as the thorax, widely divergent, curved with convexity outwards, club-shaped at the distal end, with denticulate edges. Dimensions. — -Cephalis 0*02 long, 002 broad ; thorax O^l long, 0-12 broad. Habitat. — Equatorial Atlantic, Station 347, depth 2250 fathoms. 10. Lychnocanium falciferum, Ehrenberg. Lychnocanium /aZci/erMm, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 7; Abhandl. d. k. Akad. d. Wiss. BerUn, p. 78, Taf. viii. fig. 4. Lithomelissa falcifera, Haeckel, 1862, Monogr. d. Eadiol., p. 303. Shell inflated, rough, with deep collar stricture. Length of the two joints = 1:3, breadth = 1:3. Cephalis small, with a conical horn of half the length. Thorax subglobular, truncate, three times as broad as the constricted mouth, with small, regular, circular pores. Three feet widely divergent, twice as long as the thorax, curved like a crescent, with strong convexity outwards. Dimensioiis. — Cephalis 0-02 long, 0"02 broad; thorax 0"06 long, 0'06 broad. Habitat. — Fossil in Barbados. 11. Lychnocanium tuherosum, n. sp. (PI. 61, fig. 13). Shell co^jical, tuberculate, with deep coUar stricture. Length of the two joints = 1 : 3, breadth = 1:4. Cephalis subglobular, with a conical horn of the same length. Thorax inflated, twice as broad as the flat mouth, with small, irregular, roundish pores and scattered fenestrated tubercles. Three feet very large, angular, three times as long as the thorax, curved like a crescent, with strong convexity outwards. Bimensiom. — Cephalis 0'02 long, 0'03 broad ; thorax O^OS long, 0'12 broad. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 12. Lychnocanium hirundo, Ehrenberg. Lyclinocanium hirundo, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berhn, p. 80, Taf. vii. fig. 8. Lithornithiwn hirundo, Ehrenberg, 1854, Mikrogeol., Taf. xix. fig. 53. Lithocampe hirundo, Ehi-enberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berhn, p. 65. Shell conical, tuberculate, with slight collar stricture. Length of the two joints = 1 : 3, breadth =1:4. Cephalis hemispherical, with a conical horn of half the lengtb. Thorax cam- 1228 THE VOYAGE OF H.M.S. CHALLENGER. panulate, twice as broad as the flat mouth, with longitudinal, divergent ribs, alternating with rows of small circular pores. Three feet divergent, striated, gradually lessening from a broad base, twice as long as the thorax, curved like a crescent, with convexity outwards. Dimensions. — Cephalis 0-02 long, 0'03 broad ; thorax 0-06 long, 0-08 broad. Habitat. — Fossil in Tertiary rocks of Barbados and the Mediterranean (Sicily, Greece). 13. Lijchnocanium fenestratum, n. sp. (PI. 61, fig. 10). Shell pear-shaped, rough, with slight collar stricture. Length of the two joints = 1:4, breadth = 1:3. Cephalis subglobular, with a very large prismatic horn, which is about as long as the shell, with three denticulate, prominent, wing-like crests, which are pierced by a series of pores. Thorax ovate, three times as broad as the constricted, prominent mouth, with subregular, circular pores. Three feet arising somewhat above the mouth, prismatic, with denticulate edges, about as long as the thorax, divergent, curved, with convexity outwards. Dimensions. — Cephalis 0-02 long, 0-03 broad; thorax 0'08 long, 0'08 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 14. Lychnocanium sigmopodium, n. sp. (PL 61, fig. 15). 1 Lychnocanium fetrapodium, Eluenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Beflin, p. 80, Taf.- vii. fig. 3. Shell campanulate, rough, with distinct collar stricture. Length of the two joints = l:4, breadth = 1:3. Cephalis subspherical, with a slender, pyramidal horn twice the length. Thorax inflated, conical, with regular, circular ]^)ores and a wide open mouth of nearly the same breadth. Three feet widely divergent, twice as long as the thorax, angular, S-shaped, or curved with convexity inwards. (Lijchnocanium tctrapodium of Ehrenberg is perhaps a variety of this species ?). Dimensions. — Cephalis 0-02 long, 0'03 broad ; thorax O'OS long, 0-09 broad. Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Pacific, maay stations at various depths ; also fossil in Barbados and Sicily. 15. Lychnocanium trichopus, Ehrenberg. Lychnocanium trichopus, Ehrenberg, 1875, Abhandl. d. k. Akad. d.Wiss. Berlin, p. 80, Taf. vii. fig. 5. Shell conical, smooth, with deep collar stricture. Length of the two joints = 1:3, breadth = 1:3. Cephalis subspherical, with a rudimentary conical horn of half the length. Thorax cam- panulate, with regular, circular pores and wide open mouth of nearly the same breadth. Three feet divergent, very slender, four to five times as long as the thorax, not broader than one pore, S-shaped, or curved with convexity inwards in the distal half. Dimensions. — Cephalis 0-02 long, 0-03 broad ; thorax 0-07 long, 0-09 broad. Habitat. — Fossil in Barbados. REPORT ON THE RADIOLARIA. 1229 Subgenus 3. Lychnocanoma, Haeckel. Definition. — Feet parallel, vertical, straight, or little curved ; divergent in the basal half, often convergent in the distal half ; their terminal distance about equal to the basal distance. 16. Lychnocaniimi tripodium, Ehrenberg. Li/chnocanium tripodium, Ehrenberg, 1875, Abhandl. d. k, Akad. d. Wiss. Berlin, p. 80, Taf. vii; fig. 2. Shell ovate, smooth, with distinct collar stricture. Length of the two joints = 1:4, hreadth = 1 : 4. Cephahs subglohular, with a slender conical horn twice the length. Thorax inflated, twice as broad as the constricted mouth, ^vith small, regular, circular pores. Three feet slender, prismatic, twice to three times as long as the thorax, nearly straight and. parallel, vertical. Dimensions. — Cephahs 0-02 long, 0"02 broad ; thorax 0-07 long, 0'07 broad. Habitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms; also fossil in. Barbados. 17. Lychnocanium cypselus, Ehrenberg. Lychnocaniiim cypselus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. vii. fig. 10. Shell slender, ovate, with slight collar stricture. Length of the two joints = 1 : 4, breadth = 1 : 3. Cephahs subspherical, with a conical horn of the same length. Thorax ovate, truncate, three times as broad as the narrow, constricted mouth, with small, regular, circular pores. Three feet slender, somewhat shorter than the thorax, Httle curved, with convexity outwards, nearly parallel, vertical. (In the specimen figured by Ehrenberg, the third foot was broken off.) Dimensions. — Cephahs 0-02 long, 0'02 broad ; thorax 0'08 long, 0'06 broad. Habitat. — Fossil in Barbados. 18. Lychnocanium ovatum, n, sp. Shell ovate, rough, without external collar stricture. Length of the two joints = 1 : 6, breadth = 1:5. Cephahs conical, with a stout conical horn of the same length. Thorax ovate, four times as broad as the nan'ow constricted mouth, with small, regular, circular pores, separated by hexagonal frames of twice the breadth. Three feet cyUndrical, half as long as the thorax, and three times as long as broad, straight, parallel, vertical. Dimensio'iis. — Cephahs 0"02 long, 0'02 broad ; thorax, 0'12 long, 0"1 Ijroad. HaUtat. — South Atlantic, Station 332, depth 2200 fathoms. 1230 THE VOYAGE Of H.M.S. CHALLENGER. 19. Lychnocanium crassipes, Ehrenberg. Lychnocanium crassipes, Ehienberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. vii. ■fig. 7. Shell campanulate, rough, with deep eoUar stricture. Length of the two joint.s = 1:3, breadth = 1:4. Cephalis subspherical, with a thin conical horn of the same length. Thorax semi-ovate, three times as broad as the narrow constricted mouth, with fifteen to twenty divergent, denticulate ribs, alternating with the same number of rows of small, regular, circular pores. Tliree feet very stout, as long as the thorax, cylindrical, nearly straight and parallel, vertical, at the distal end clavate, spinulate or a little forked. Dimensions.- — Cephalis 0'02 long, 0'02 broad ; thorax 0'06 long, O^OS broad. Habitat. — Fossil in Barbados. 20. Lychnocanium clavigerum, u. sp. (PI. 61, fig. 4). Shell campanulate, sulcate, with sharp coUar stricture. Length of the two joints = 1:4, breadth = 1:5. Cephalis subglobular, with a spindle-shaped papillate horn twice the length. Thorax nearly spherical, truncate at both poles, three times as broad as the narrow, constricted, somewhat tubular mouth, with fifteen to twenty elevated meridional ribs, alternating with the same number of rows of circular pores. Three feet slender, cylindrical, twice as long as the thorax, in the basal half divergent, in the distal half convergent, club-shaped, with a thickened papillate end. Dimensions. — Cephalis 0"02 long, 0"025 broad ; thorax 0-08 long, O'Ol broad. Habitat. — Indian Ocean, Madagascar, surface (Rabbe). 21. Lychnocanium /pudicum, n. sp. (PI. 61, fig. 2). Shell campanulate, with deep collar stricture. Length of the two joints = 1:3, breadth = 1:3. Cephalis heraispherical, hyaline (without pores), with a short and thick club-shaped, spinulate horn of the same length. Thorax subglobular, truncate at both poles, twice as broad as the constricted mouth, with small, irregular, roundish pores. Three feet somewhat shorter than the thorax, curved like a crescent, with convexity outwards ; theu- distal ends club-shaped, spinulate, convergent towards the central axis. Dimensions. — Cephalis 0-02 long, 0'025 broad ; thorax 0'06 long, 0'07 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. Genus 549. Lychnodictyxim,'^ Haeckel, 1881, Prodromus, p. 432. Definition. — Se t h opilida (vel Dicyrtida triradiata aperta), with three latticed terminal feet on the peristome, without thoracic ribs. Cephalis originally with a horn (sometimes lost). •^ Lychnodictyum = Lantern with network ; 'hCx.^fSt SiWvoy. REPORT ON THE RADIOLARIA. 1231 The genus Lychnodictyum differs from the preceding Lychnocanium only in the fenestration of tlie three terminal feet, and bears therefore to it the same relation that the ancestral Tripocyrtis does to Dictyophimus, 1. Lychnodictyum challengeri, Haeckel. Dictyopodium challengeri, Wyville Thomson, 1877, Atlantic, voL i. p. 234, fig. 52. Didyophimus (vel Tripocyrtis) rJiallengm-i, Haeckel, 1878, Protistenreich, p. 47, fig. 35. Shell campanulate, smooth, with sharp collar stricture. Length of the two joints = l:3, breadth = 1:4. Cephalis siibspherical, with a large, oblique, pyramidal horn thrice the length. Thorax with three inflated bosoms between the three decurrent ribs, which are prolonged into tln-ee vertical, parallel, pyramidal, in the upper half fenestrated feet, as long as the thorax. Pores regular, circular. Mouth constricted, flat, half as broad as the thorax. Dhnamons. — Cephalis 0'03 diameter; thorax 0'08 long, 0'12 broad. Habitat. — Tropical Atlantic, Station 338, depth 1990 fathoms. 2. Lychnodictyum wyvillei, n. sp. Shell pyramidal, smooth, witli obhterated collar stricture. Length of the two jomts = 1:3, lireadth = 1:5, Cephalis subspherical, with a large, straight, pyramidal horn of ■ twice the length. Thorax nearly tetrahedral, inflated, with three rounded, decurrent ribs, which are prolonged into three widely divergent, angular, curved feet, about as long as the shell, with pyramidal fenestrated base. Pores regular, circular. Mouth constricted, flat, half as broad as the thorax. DimensioTis. — Cephalis 0'025 diameter; thorax O'OS long, 0"12 broad. Habitat. — Central Pacific, Stations 266 to 274, depth 2350 to 2925 fathoms. 3. Lychnodictyum scaphopodium, n. sp. (PI. 56, fig. 4). Cephalis hemispherical, large, without liorn, with irregular, small, roundish pores. Thorax a little larger, campanulate, with three broad, shovel-shaped, fenestrated, vertical feet, and larger, irregular pores. In the figured specimen the third (posterior) foot was broken off. In another speciT men the three feet were somewhat longer and not so broad. Dimensions. — Cephalis 0"03 long, 0'05 broad ; thorax 0'05 long, 0'06 broad. Habitat. — Central Pacific, Station 274, depth 2750 fathoms.. 4. Lychnodictyum sethopodium, n. sp. Cephahs hemispherical, large, with a rudimentary conical horn, and very scarce small pores. Thorax twice as broad and long as the cephalis, campanulate, with irregular, roundish pores, and three slender, pyramidal, divergent feet twice the length, which in the upper half are fenestrated, in the lower half solid. Birmnsions. — Cephalis 0'025 long, 0'045 broad ; thorax G'05 long, 0'09 broad; Habitat. — South Atlantic, Station 330, surface. 1232 THE VOYAGE OF H.M.S. CHALLENGER. Subfamily 2. Sethopeeida, Haeckel, 1881, Prodromus, p. 433. Definition. — T r i p o c y r t i d a with the basal mouth of' the shell fenestrated (vel Dicyi-tida triradiata clausa). Genus 550. Sethopera,^ Haeckel, 1881, Prodromus, p. 433. Definition. — S ethoperida (vel Dicyrtida trmadiata clausa), with three divergent ribs enclosed in the latticed wall of the thorax. Cephalis with a horn. The- genus Sethopera is probably the oldest form of the Sethoperida, and may therefore be regarded as the common ancestral form of this subfamily. The thorax exhibits three radial ribs, which are completely enclosed in its wall. Sethopera may be derived either from Dictyophimus or from another of the Sethopilida {^Lamprodiscus, Clatlirocanium) by development of a basal lattice-plate closing the mouth). There are often wide holes or open spaces between the three radial ribs. 1. Sethopera tncostata, n. sp. (PL 97, fig. 11). Cephahs subspherical, spinulate, with a pyramidal horn of the same length. Length of the two joints = 5 : 8, breadth = 5 : 8. Thorax also nearly spherical; in the upper half with three stout, prismatic, convex, divergent ribs, and three large ovate holes between them; in the lower half with numerous small and irregular pores, spinulate. Bimensicms. — Cephalis 0'05 diameter ; thorax 0'08 diameter. Hahitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 2. Sethopera Oceania, Haeckel. Lithopera Oceania, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 297, Taf. iv. fig. 21. Cephalis hemispherical, with a small bristle-shaped horn of half the length (broken off' in Ehrenberg's figure). Length of the two joints = 3 : 4, breadth = 3 : 4. Thorax nearly spherical; in the upper half with three divergent ribs, separated by some larger, irregular pores ; in the lower half with numerous small, irregular, roundish pores. Dimensions. — Cephalis 0*03 long, 0'03 broad ; thorax 0'04 long, 0'04 bi'oad. Habitat. — North Atlantic, Station 354, surface ; Canary Islands and Azores. 3. Sethopera pyrum, Haeckel. 'i Lithopera pyrum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 297. Cephalis hemispherical, with a small conical horn of half the length. Length of the tw-o joints = 3 : 10, breadth = 3:7. Thorax pear-shaped, with rather large, regular, quiucuncial pores ; ^ /Se(/t02Je)-a = Sieve-pouch ; a^^w, tt^jos. REPORT ON THE EADIOLARIA. 1233 its upper half with three divergent ribs in the wall, half as broad as the subspherical lower half. (The three ribs probably were overlooked by Ehrenberg.) Dimensions. — Cephalis 0"03 long, OOo broad ; thorax Ol long, 0-07 broad. Sahitat. — North Pacific, Station 256, surface ; Californian Sea, 2600 fathoms, Ehrenberg. 4. Sethopera lagena, Haeckel. Lithopera lagetia, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iii. fig. 4. Cephalis pear-shaped, with a small conical horn of half the length. Length of the two jioints = 3:8, breadth = 3:6. Thorax smooth, pear-shaped, with irregular roundish pores ; in the wall of its upper third three divergent thin ribs (sometimes wanting) ; the lower half inflated. (Compare Scthocapsa lagciui.) Bimensions. — Cephalis 0'03 long, 0'03 broad ; thorax 0"08 long, 0"06 broad. Habitat. — Fossil in Barbados. Genus 551. Lithoperet,^ Ehrenberg, 1847, Monatsber, d. k. preuss. Akad. d.. Wiss. Berlin, p. 54. Definition. — S ethoperida (vel Dicyrtida triradiata clausa), with three divergent ribs enclosed in the cavity of the thorax. Cephalis wdth a horn. The genus Lithopera is, like the preceding Sethopera, one of the most simple and oldest forms of the Sethoperida, and exhibits three divergent thoracic ribs, which are prolonged neither into lateral wings nor into basal feet. But whilst in Setho2iera the three ribs are enclosed in the lattice-work of the shell-wall, in Lithopera they lie freely in its cavity, and are overgrown by the enveloping shell-wall, being inserted on its inner face with their distal ends. Lithopera may be derived directly from Lithomelissa, by development of lattice-work closing the shell-mouth. Therefore the lower part of the cephalis is hidden in the uppermost part of the thorax ; only its upper part is free. 1. Lithopera bacca, Ehrenberg. Lithopera bacca, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berhn, p. 297, Taf. viii. fig. 1. CephaKs spherical, with small, irregular pores and a bristle-shaped spine of half the length ; its lower half hidden in the thorax. Length of the two joints = 1:6, breadth = 1:5. Thorax ellipsoidal, smooth, with regular, hexagonal, small pores, and very thin, thread-like bars. From the deep collar stricture there arise three internal, divergent bars, which are inserted at the uppermost third of the thorax. Dimensions. — Cephalis 0'02 diameter ; tliorax 012 long, O'l broadi Habitat. — Tropical Pacific, Stations 200, 224, 266, 271, &c., surface.. 1 ii(/iD;pera = Stone-pouch ; x/tfoj, ■nijoa.. (ZOOL. CHALL. EXP.- — PART XL. — 1886.) Rf 155 1234 THE VOYAGE OF H.M.S. CHALLENGEE. 2. Lithopera bursella, Ehrenberg. Lithopera Inirsella, Ehreaberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 297, Taf. x. fig. 4. Sliell of about the same form and structure as in the nearly allied preceding species, but smaller, of more slender form, with smaller pores and thinner bars. Length of the two joints = 1 : 5, breadth = 1 : 3. In the specimen' observed by me the three internal, divergent bars of the ellipsoidal thorax (not seen by Ehrenberg) were as distinct as in the similar preceding and following species. Dimensions. — Cephalis 0'02 diameter ; thorax 01 long, 0-06 broad Habitat. — Indian Ocean, Zanzibar (Pullen), Madagascar (Eabbe), surfaca 3. LitliO'pera ancmassa, u. sp. (PI. 57, fig. 3). Shell of about the same form and structure as in the two preceding species, but larger and more robust, and differing' in the spiny surface. Length of the two joints =1 :5, breadth =1 : 4. Here also the lower half of the spherical cephalis is submerged in the ellipsoidal thorax, and from the collar stricture arise three strong, internal, divergent beams. The bars of the hexagonal pores are much tliicker than in the two preceding species. Dimensions. — Cephalis O'OS diameter; thorax OIG long, 0'12 broad. Habitat. — Tropical Atlantic, Stations 347 to 352, surface. 4. Lithopera glohosa, n. sp. Cephalis spherical, very small, witli two divergent conical horns of half the length ; its lower half hidden in the thorax. Length of the two joints = 1 : 5, breadth = 1 : 5. Thorax spherical, with regular, circular, hexagonally-framed pores. From the collar stricture arise three radial internal beams, horizontally diverging, and inserted at the inside of the thorax. Dimensions. — Cephalis 0'03 diameter; thorax 0"15 diameter. Habitat.- — Central Pacific, Stations 271, depth 2425 fathoms. 5. Lithopera gutta, Etrenberg, Uthopera gutta, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 297, Taf. viii. fig. 2. Shell pear-shaped, with sliarp coHar stricture. Length of the two joints =1 : 4, breadth = 1 : 3, Cephalis spherical, with a conical horn of the same length ; its lower half hidden in the iippermost part of the ovate thorax, and connected with its wall by three internal, cortinar beams. Pores of the thorax very irregular in form and size, partly lobed. Dimensions. — Cephalis 0-02 diameter; thorax O'OS long, 0'06 broad. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms ; Philippine Sea (depth 3300 fathoms), Ehrenberg. REPORT ON THE RADIOLARIA. 1235 Genus 552. Micromelissa,^ Haeckel, 1881, Prodromus, p. 433. Definition. — S ethoperida (vel Dicyrtida triradiata clausa), wdth three divergent, solid, lateral wings. Ceplialis with a horn. The genus Micromelissa diflers from the two preceding genera in the free pro- minence of the three cortinar ribs, forming three solid lateral wings. Beyond these the thorax walls are convergent, and the basal mouth closed by a lattice-plate. Therefore Micromelissa may have arisen from Lithomelissa simply b)' development of this basal mouth-plate. 1. Micromelissa bo^nbus n. sp. (PI. 57, fig. 14). Shell smooth, with sharp collar stricture. Length of the two joiuts =1:4, breadth = 1:5. Cephalis spherical, with an oblique conical horn of the same length. Thorax subspherical, in the upper half with three conical, downwardly diverging wings, about as long as its radius. Pores very small and scarce. Bivunsions. — Cephalis 0"02 long, 002 broad ; thorax 0'09 long, 0"1 broad. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Micromelissa vespa, n. sp. Shell smooth, with deep collar stricture. Length of the two joints = 2:5, breadth = 2:3. Cephalis spherical, with an oblique pyramidal horn twice the length. Thorax inversely ovate, in the upper half with three pyramidal wings, which are equal to its breadth, little curved and diverging downwards. Pores very small and scarce. Dimensions. — Cephalis 0'04 diameter ; thorax Ol long, 0'06 broad. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 3. Micromelissa apis, n. sp. Shell rough, with deep coUar stricture. Length of the two joints = 2:3, breadth = 2:4. Cephalis subspherical, with a straight conical horn of half the length, and subregular, circular, double- contoured pores, of the same breadth as the bars. Thorax Uttle larger, subspheiical, with irregular, roundish pores, twice to four times as broad as the bars. From its lower half arise three short conical wings, curved downwards, and half as long as the cephahs. Dimensions. — Cephahs 0'04 long, 0'04 broad ; thorax O'QG long, 0'08 broad. Habitat. — South Pacific, Station 295, depth 1500 fathoms. ' Micromelissa = Small bee ; /aix^o;, fttT^iaax. 1236 THE VOYAGE OF H.M.S. CHALLENGER. 4. Micromelissa microptera, Haeckel. Lithomelissa microptera, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 2 ; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 78, Taf. iii. fig. 13. Lithomelissa microptera, Biitschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 539, Taf. xxxiiL fig. 26. Shell smooth, with distinct collar stricture. Length of the two joints = 4 : 6, breadth = 3 : 5. 'Cephalis ovate, with a straight sword-shaped horn of the same length and very small pores, some larger ones above tlie stricture. Thorax little larger, ovate, nearly hyaline, with very few and small scattered pores. From its uppermost part arise three short conical wings, scarcely half as long as the -cephalic horn, little curved and divergent downwards. Bimensiom.— Cephalis 0'04 long, 0'03 broad ; thorax 0'06 long, O'Oo broad. Habitat. — Fossil in Barbados. 5. Micromelissa mentricosa^ Haeckel. Lithomelissa ventricosa, Ehrenberg, 1875, Abhandl. d. k. AkaJ. d. Wiss. Berlin, p. 78, Taf. iii. fig. 11. Shell rough, with slight collar stricture. Length of the two joints = 1 : 7, breadth = 1 : 5. Cephalis small, hemispherical, with a small conical horn of half the length, Thorax ovate, very large, papillate, with irregular, roundish pores. From its basal part arise three short and stout conical wings at great distances, shorter than the cephalis. (A transition-form to Scthoca2)sa.) Dimensions. — Cephalis 0-02 long, 0'022 broad; thorax 0'14 long, O-ll broad. Habitat.- — Fossil in Barbados. Genus 553. Peromelissa,^ Haeckel, 1881, Prodromus, p. 433.. Definition. — S ethoperida (vel Dicyrtida triradiata clausa) with three divergent solid lateral wings. Cephalis without horn. The genus Peromelissa differs from the preceding ancestral form, Micromelissa^ only in the absence of the cephalic horn, which is lost by reduction. 1. Peromelissa plialacra, n. sp. (PI. 57, fig. 11). Shell smooth, with two joints of nearly equal size and similar ovate form. Cephalis in the upper half hyaline, without pores ; in the lower half with four remote, transverse rows of irregular, roundish pores, decreasing in size towards the hemispherical summit. Thorax with twelve transverse ' 'Peromelissa = Pouch-bee ; 5r^f«, fitXitjau. REPORT ON THE RADIOLARIA. 1237 rows of pores, the upper six rows three to four times as large as the lower six rows. From its upper half diverge almost horizontally three angular club-shaped wings, half as long as the shell Dimensions. — Cephalis 0'05 long, O^OG broad ; thorax 0'06 long, 0'05 broad. Hahiiat. — Western Tropical Pacific, Station 225, depth 4475 fathom.s. 2. Peromelissa psilocrana, n. sp. Shell smooth, very similar to the preceding species in size and form, but differing from it in the disposition of the irregular, roundish pores, which are irregularly scattered, and in the form of the three wings, wliich are slender, pyramidal, diverging downwards, and about as long as the entire shell. Dimensions. — -Cephalis 0'07 long, 0'06 broad ; thorax 0'07 long, 0'06 broad. Habitat. — Central Pacifi-c, Station 272, depth 2600 fathoms. 3. Peromelissa capita, Haeckel. ■Lithomelissa capito, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iii. fig. 14. Shell rough, with two joints of nearly equal size and similar ovate form. Pores irregular, roundish, eveiywhere scattered. From the upper half of the thorax arise three short conical wings, which are little curved and diverge downwards (scarcely half as long as the breadth of the shell). Dimensions. — Cephalis 0-07 long, 0"06 broad ; tJiorax 007 long, 0'06 broad. Habitat. — Fossil in Barbados. 4. Peromelissa calva, u. sp. (PI. 57, fig. 12). Shell rough, with two ovate joints of somewhat different sizes. Pores irregular, roundish, every- where scattered. Thorax little larger than the cephaKs ; from its upper half arise three short conical wings, diverging downwardly or nearly horizontally. Dimensions. — Cephalis 0-06 long, 0'04 broad ; thorax 0-7 long, 005 broad. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. Genus 554. Sethomelissa,^ Haeckel, 1881, Prodromus, p. 43L Definition. — S e t h o p e r i d a (vel Dicyitida triradiata clausa) witli three divergent latticed lateral wings. Cephalis with a horn (or a launch of horns). The genus Sethomelissa differs from the nearly allied Micromelissa in the fenestra- tion of the three lateral wings, and may be derived either from this genus by develop- ment of lattice -work connecting the three wings with the shell, or perhaps from Clathrocanium by closing the mouth. • Sethomelissa = Sieve-bee ; viieu, (li'Maaa. 1238 THE VOYAGE OF H.M.S. CHALLENGER. 1. Sethomelissa hymenoptera , n. sp. Cephalis subsplierical, thorny, with a bunch of three divergent, larger apical spines. Thorax ■pear-shaped, with three broad, triangular, latticed wings, the superior edge of which is a horizontal straight, and stout spine, nearly as long as the thorax. Pores irregular, roundish. Dimensions. — Cephalis O'O.S diameter; thorax Oil long, 0-08 broad. habitat. — Central Pacific, Station 271, depth 2425 fathoms. • 'Genus 555. Tetrahedrina,^ Haeckel, 1881, Prodromus, p. 433. Definition. — S e t h o p e r i d a (vel Dicyrtida trii-adiata clausa) with a three-sided •pyramidal thorax, the three edges of which are prolonged into three divergent, solid, terminal feet. Cephalis wilih a horn. The genus Tetrahedrina, and the two following, nearly allied genera, are distin- guished by the possession of three free, divergent, terminal feet,, projecting over the latticed mouth of the thorax. Tetrahedrina may be derived directly from Dictyo- 2)himus, by development of a horizontal latticed mouth-plate from the middle part of the feet, the lower part of which remains free. This genus, not noticed by Ehrenberg, is similar to his Lithochytris, and common in the Barbados .deposits. 1. Tetrahedrina pyramidalis, n. sp. Shell three-sided pyramidal, smooth, with shght collar stricture. Length of the two joints = 1:4,. breadth = 1:4. Cephalis hemispherical, with small, sparsely disposed pores, and a pyramidal horn of the same length. Thorax with subregular, circular pores and three sharp edges, prolonged into three divergent pyramidal feet of the same length. Dimensions. — Cephalis 0-03 diameter ; thoi'ax 012 long, 012 broad. Habitat.. — -Fossil in Barbados. 2. Tetrahedrina pyriformis, n. sp. SheU pear-shaped, rough, with distinct collar stricture. Length of the two joiiits = 2 :,6, lireadth = 2:5. Cephalis subspherical, with a conical horn of the same length. Thorax with sub- regular, circular pores, ovate, at the broad base with three pyramidal, widely divergent feet of the same length. (Similar to Lychnocanium trihulus, Ehrenberg, 1875, loc. cit.,iA. vii. fig. 1, but with the mouth closed by a lattice-plate.) Dimensions. — Cephalis 0-04 diameter; thorax 012 long, 01 broad. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. ^ Tetrahedrina =SmaU tetrahedron ; Tfr^it^ou. REPORT ON THE RADIOLARIA. 1239 3. Tetrahedrina quadricornis, HaeckeL Lithochytris triangula, Bury, 1862, Polycystins of Barbados, pi. xix. figs. 4, 5, 6. Shell pear-shaped, papillate, with sKght collar strictura Length of the two joiiits=l:5, breadth =1:5. Cephalis subspherical, with a stout conical horn twice the length. Thorax with irregular, roundish, lobulated pores, with three conical, stout, divergent feet at the base, of the same- size and form as the cephalic horn. Dimensioiis. — Cephalis 0'02 diameter ; thorax O'l long, O'l broad. Habitat. — Fossil in Barbados. Genus 556. Sethochytris,^ Haeckel, 1881, Prodromus^ p. 433. Definition. — S etlioperida (vel Dicyrtida triradiata clausa) with three terminal latticed feet or hollow, fenestrated, divergent, basal apophyses of the thorax. Cephalis with a horn. The genus Sethochytris differs from the preceding Tetrahedrina in the fenestration of the three basal feet, which form direct protrusions or evaginations of the three basal corners of the pyramidal shell. It may be derived from Sethopera by centrifugal growth of the basal corners. 1. Sethochytris triconiscus, n. sp. (PI. 57, fig. 13). Shell rough, with deep collar stricture. Length of the two Joints = 1:8, breadth = 1:3. Cephalis spherical, with an oblique pyramidal horn of the same length. Thorax campanulate, conical ; its three basal corners prolonged into three divergent, slender, hoUow, fenestrated cones, twice as long as the thorax, and ending in a stout pyramidal spine. Dimensions. — Cephalis 0'04 diameter, thorax 012 diameter, length of the feet 0"2. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 2. Sethochytris barhadensis, Haeckel. Lithochytris barhadensis, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 160,- Taf. V. fig. 2. Shell smooth, with slight coUar stricture. Length of the two joints = 1:6, breadth = 1:4. Cephalis ovate, witli a conical horn of half the length. Thorax conical ; its base prolonged into three divergent, hollow, fenestrated cones, half as long as the thorax. Pores small, subregular, circular. Dimeiisions.-^C e]ihalis 0-025 diameter, thorax 01 diameter, length of the feet 0'05. Habitat — Fossil in Barbados. ' Sethochytris = Sieve-'pot; oijiu, x"'''?';- 1240 THE VOYAGE OF H.M.S. CHALLENGER. 3. Sethochytris pyramis, n. sp. Shell smooth, with slight collar stricture. Length of the two joints = 1:8, breadth = 1:5. Cephalis ovate, with a conical horn of half the length. Thorax pyramidal, with three sharp edges ; its base prolonged into three pyramidal, divergent, hollow, fenestrated feet, nearly as long as the thorax. Pores regular, circular, double-contoured. Dimensions. — Cephalis 0-04 diameter ; thorax 0-2 diameter, length of the feet 0-15. Eabitat. — Central Pacific, Station 265, depth 2900 fathoms ; also fossil in Barbados; 4. Sethochytris triangula, Haeckel. Idthochytris triangula, Bur.y, 1S62, Polycystins of Barbados, pi. xix. fig. 7. Shell rough, with obliterated collar stricture (but distinct internal coUar septum). Length of the two joints = 1:6, breadth = 1:3. Cephalis subspherical, with a stout conical horn of the same length. Thorax pear-shaped, inflated ; its base prolonged into three divergent, hollow, fenestrated cones, about as long as the thorax. Pores regular, circular. Dimensions. — Cephalis Q-Oo diameter; thorax 0-09 diameter, length of the feet O'l. Habitat. — Fossil in Barbados. Genus 557. ClathroIychmis,i Haeckel, 1881, Prodromus, p. 431. Definition. — S ethoperida (vel Dicyrtida triradiata clausa), with three vertical',, lateral latticed wings stretched between the apical horn and the three terminal feet. The external kttice-work connecting the wings and closing the mouth forms an arachnoidal mantle around the shell. The genus Clathrolychnus may be derived directly from Clathrocorys, by develop- ment of an external arachnoidal mantle connecting the three wings and the three feet,, and enveloping the whole shell, closing at the same time the basal mouth of the thorax, by a fenestrated plate. 1. Clathrolychnus araneosus, n. sp. {PI. 64,, fig. 5). Cephalis subspherical, with irregular, polygonal pores and a large pyramidal horn of twice the length. Length of the two joints = 4 : 9, breadth = 5 : 12. Thorax with three large triangular holes (twice as broad as the cephalis) between the three pyramidal, divergent feet, which at the distal end are connected by a narrow band of network, composed of two or three rows of polygonal pores. The entire pyramidal shell is enveloped by a very delicate web of irregular, polygonal ' Clathrolychnus =''Fenestrated lantern ; x>^^ja, hvx,"";. REPORT ON THE RADIOLARIA. 1241 meshes, closing also the basal mouth. (In fig. 5 the greater part of the web is taken off U> demonstrate the large holes of the thorax). Only two feet are visible. Dimensions. — Cephalis 004 long, 005 broad ; thorax 009 long, 0-12 broad. HabUai. — Central Pacific, Station 274, surface. 2. Clathrohjchnus penplectus, n. sp. (PI. 64, fig. 6). Cephalis subspherical, with subregular, circular pores and a pyramidal horn of the same length. Length of the two joints = 1 -.2, breadth =1:3. Thorax with three large elliptical holes between the three pyramidal, divergent feet, which are connected at the distal end by a broad band of net- work, composed of five to ten rows of polygonal pores. The entire pyramidal shell is enveloped by a very delicate web, which on the sides is composed of subregular, square meshes, and on the closed mouth of polygonal meshes. (In fig. 6 only a part of the web is represented.) Dimensions. — 004 long, 005 broad ; thorax 0-08 long, 0-14 broad. Hdbitat. — Central Pacific, Station 271, surface. Family LXIII. A n t h o c y r t i d a, n. fam. Sethyphormida et Sethophxnida, Haeckel, 1881, Prodiomus, p. 432, -133. Definition. — D i c y r t i d a multiradiata. (C y r t o i d e a with a two-jointed shell, divided by a transverse constriction into cephalis and thorax, and bearing- numerous — four to nine or more — radial apophyses.) The family A n t h o c y r t i d a, composed of the Sethophormida and Sethophsenida of my Prodromus, comprises those C y r t o i d e a in which the shell is two-jointed and bears numerous radial apophyses. The two subfamilies differ in the shape of the mouth, which in the Sethophormida is a simple, wide opening ; in tlie Sethophsenida closed by a lattice-plate. Numerous fossd and living forms of Anthocyrtida were described formerly by Ehrenberg in his genera Carpocanium and Anthocyrtis. These, however, represent only a small part of the whole family, which exhibits a great variety in the composition of the lattice-work and in the number of radial beams. The number of species here described amounts to one hundred and forty, and these are disposed in fourteen genera (twelve Sethophormida and two Sethophaenida). The Sethophormida may be again divided into two different groups or tribes, the Setliamjihorida and Carpocanida ; in the former the thorax bears numerous radial ribs, enclosed in its wall ; in the latter these ribs have disappeared, and only a corona of terminal feet is developed around the mouth. The shell of the former is usually pyramidal, with a widely open mouth ; of the latter ovate, with a constricted mouth. The mouth of the thorax becomes perfectly closed in the Sethophsenida. (ZOOL. CHALL. EXP. — PART XL. — 1886.) Rr 156 1242 THE VOYAGE OF H.M.S. CHALLENGER. The majority of the Anthocyrtida may be derived from the Polyspyrida {Petalo- spyris, &c.) by reduction of the cephalis aud loss of the sagittal ring, as was suggested by Biitschli (1882, loc. cit). But another part may also have arisen from the Tripoeyrtida, by interpolation of secondary radial apophyses between the three primary perradial apophyses. The cephalis in this family is developed in all possible degrees, from one of a considerable size to one very much reduced. If it becomes perfectly lost, the Cyrto- calpida arise. 1. Subfamily Sethophormida. Terminal mouth of the thorax a simple wide opening. Synopsis of the Genera of Antlwcyrtida. Shell flat, . campanulate or nearly discoidal (cephalis without horn), Shell ovate, with constricted mouth (■without horn), Radial ribs smooth (rarely thorny) enclosed in the wall of the thorax (cepha- ■ lis commonly small, with out horns). Shell slender pyramidal, with straight ribs. Eadial ribs thorny (rarely smooth) prolonged into free terminal feet (cepha- lis commonly large, with one or more horns). ]\Ieshes of the network simple, Meshes fenes- trated by secondary lat- ticework. Meshes closed by spongy framework, . Shell not enveloped by arach- noidal network. Shell enveloped by arachnoidal network. No ribs in the thorax. Peristome with free terminal feet. Cephalis well- developed, - with an apical horn Feet terminal, without separate peristome. Six feet, Nine feet. Twelve or more feet. Feet subterminal, outside the constricted peristome. II. Subfamily Sethopha;nida. Terminal mouth closed " by a lattice-plate. Cephalis rudimentary, hidden in the upper part of the thorax, without horn, . Thorax with lateral apophyses (four to six or more wings), Thorax with terminal apophyses (four to six or more feet), 558. Sethophormis. 5-59. Sethainpliora. 560. Setkopyramis. 561. Plectopyramis. 562. Spiongopiyramis. 563. Accmthocwys, 56 L Araehnocorys. 565. Anihoryrtoma. 566. Anthocyrtis. 567. Antliocyrtium. 568. Atitlioeyrtidium. 569. Carpocanimn. 570. SetJiojJhama. 571. Clistopilucna. REPORT ON THE RADIOLA.RIA. 1243 Subfiimily 1. Sethophormida, Haeckel, 1881, Prodromus, p. 432. Definition. — A n t li o c y r t i d a with the basal mouth of the shell open (vel Dicyrtida multiradiata aperta). Genus 558. Sethophormis, Haeckel/ 1881, Prodromus, p. 432. Definiti(yii. — S e t h o p h o r m i d a (vel Dicyrtida multiradiata aperta) with numerous radial ribs in the wall of the liat and broad, campanulate or nearly discoidal thorax. Cephalis also flat and broad, cap-shaped, mthout horn. The genus Sethophormis comprises a great number of widely distributed and large Dicyrtida, all agreeing in the flat cap-shaped or nearly discoidal form of the thorax, which has constantly a very delicate network, and is pierced by numerous radial beams. Four of these are commonly primary and direct prolongations of the four cortinar rods in the collar septum, whilst the others are secondary or interpolated ribs. Sethophormis may be derived either from the triradial Lamprodiscus by multiplication of the ribs (or interpo- lation of secondary ribs between the three primary), or from lialicalyptra by develop- ment of transverse rods connecting its terminal feet, and forming a ribbed thorax. Corresponding to the number of the ribs, we may distinguish as subgenera (separate genera in my Prodromus, 1881, p. 432) Tetraphormis with four, Pentaphormis with five, Hexaphormis with six, Octophormis with eight, Enneaphormis with nine, and Astro- phormis with ten to twenty or more ribs. The cephalis bears no horn, and is usually large, flat, cap-shaped or hemispherical. Subgenus 1. Tetraphormis, Haeckel, 1881, Prodromus, p. 432. Definition. — Thorax with four radial ribs, opposite in pairs in two meridional planes, perpendicular to one another. CoUar septum with four large pores. 1. Sethophormis ci-uciata, n. sp. Cephalis very large, hemispherical, with irregular, delicate network of small square meshes. Thorax flatly campanulate, with delicate, regular network of small hexagonal meshes. All bars very thin, thread-like. Four stout radial thoracic ribs, crossed in pairs, lie in two meridional planes, perpendicular to one another. Very similar to Sethophormis aurelia (PI. 55, figs. 3, 4), but not so flat, and with only four thoracic ribs. Peristome or margin of the thoracic mouth smooth, circular. Dimensions. — Cephalis 0'04 long, 0"08 broad ; thorax 0'12 long, 0'36 broad. Habitat. — Central Pacific, Station 271, surface. 1'244 THE TOYAGE OF H.M.S. CHALLENGER. 2. Sethophormis medusa, u. sp. Cephalis very large, flat, cap-shaped, with irregular, delicate network of polygonal nieshea Thorax flat, campanulate, nearly hemispherical, with delicate, irregular network of small polygonal meshes. All bars very thin, thread-like. Four stout radial thoracic ribs, as in the preceding species. Peristome denticulate. Dimensions. — Cephalis OOS long, O'OO broad; thorax 0'15 long, 0-25 broad Habitat. — North Pacific, Station 244, surface. Subgenus 2. Pentaphormis, Haeckel, 1881, Prodromus, p. 432. Definition. — Thorax with five radial ribs, one of the three primary ribs (the odd occipital rib) being simple, the two others (the paired lateral ribs) forked 3. Sethophormis pentalactis, n. sp. (PL 56, fig. 5). Cephalis large, flat, hemispherical, with subregular, hexagonal pores. Thorax flat, campanulate, nearly hemispherical ; also with subregular, hexagonal pores, and with five stout ribs. The three primary ribs of the thorax are complete, and reach the peristome ; the two secondary ribs (as basal liranches of the two lateral ribs) are incomplete and absent in the distal half of the thorax. Peri- stome denticulate, with an elegant marginal corona of small square pores and short conical spines. Dimensions. — Cephalis 0'03 long, O'OO broad ; thorax 0"1 long, 0"2 broad. Habitat. — Central Pacific, Station 26 G, depth 2750 fathoms. 4. Sethophormis asteriscus. n. sp. Cephalis large, flat, cap-shaped, with irregular polygonal pores. Thorax flat, campanulate, with subregular, hexagonal pores, and five stout ribs. Tlie marginal distance between the two anterior (lateral) ribs is twice as great as the distance between every two other ribs (the postero-lateral ribs being basal branches of the antero-lateral' ribs). Peristome with a double corona of short, conical spines. Dimensions. — Cephalis 0'02 long, 004 broad ; thorax 0'06 long, 0"1 7 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 5. Sethophormis astrodiscus, u. sp. Cephalis small, flatly vaulted, cap-shaped, with irregular, polygonal pores. Thorax very flatly vaulted, nearly discoidal, with subregular, hexagonal pores, and five stout ribs. The marginal dis- tance between all five ribs is nearly equal. Peristome denticulate, with an elegant corona of small square pores and short conical thorns. Dimensions. — Cephalis O'Olo long, 0-035 broad ; thorax 0'05 long, 0'2 broad. Habitat. — Tropical Atlantic, Station 348, depth- 2450 fathoms. REPORT ON THE RADIOLARIA. 1245 Subgenus 3. Hexaphormis, Haeckel, 1881, Prodromus, p. 432. Definition. — Thorax with six radial ribs (three primary perradial and three second- ary interradial beams). 6. Sethophorniis hexalactis, n. sp. (PI. 56, fig. 6). Cephalis large, hemispherical, with iiTegular, polygonal pores. Thorax flatly campanulate, with' subregular, hexagonal pores, and six stout radial ribs ; the lateral connected in pairs. (Fig- 6 exhibits the central part of the shell, seen from below.) In the subcircular collar septum the two anterior (jugular) meshes are much smaller than the two posterior (cardinal) meshes. The odd anterior (sternal) lib is opposite to the posterior (caudal) rib. The two paired ribs of each side (antero-lateral or pectoral and postero-lateral or ventral ribs) diverge from one common point. In^ the specimen figured the left half of the thorax exhibited the two regular ribs, and the right half three, a posterior accessory branch being developed (transition to Odoplwrmis). This specimen might indeed be called Heptaphormis hepfaladis. Dimcnsioiis. — Cephalis 0'02 long, O'Oo broad ; thorax 0'08 long, 0'22 broad. Habitat. — Central Pacific, Station 274, depth 2750' fathoms. 7. Sethojyhormis hexagonalis, n. sp. Cephalis small, flat, cap-!5haped, with small, regular, hexagonal pores. Thorax flatly conical^ nearly discoidal, with larger pores of the same form, and six stout, straight, prominent ribs. These arise at equal distances from the six corners of the hexagonal base of the coUar septum. Peristome hexagonal, with a corona of short spines. Dimensions. — Cephahs 0'015 long, 0-04 broad ; thorax 0'06 long, 0'24 broad. Hahitat. — North Atlantic, Station 354, surface. Subgenus 4. Octojohormis, Haeckel. Definition. — Thorax with eight radial ribs, four secondary interradial beams being interpolated between the four primary perradial beams of Tetra'phonnis. 8. Sethophormis octalactis, u. sp. Cephalis large, hemispherical, with irregular, polygonal pores. Thorax flatly campanulate, with regular, hexagonal pores, and eight stout, regularly-disposed, radial ribs reaching the margin at equal distances. Four of these correspond to the four primary ribs of Tdrap>hormis cruciata, and exhibit at their base a larger j)air of basal pores, surrounded by a semicircular ring (PL 70, fig. 5) ; the other four are secondary, interpolated. Peristome circular, simple. Dimensions. — Cephahs 0'03 long, 006 broad ; thorax 01 long, 022 bi-oad. Habitat. — Indian Ocean, Madagascar (Piabbe), surface. 1246 THE VOYAGE OF H.M.S. CHALLENGER. Subgenus 5. Enneaphormis, Haeckel, 1881, Prodi-omus, p. 432. Definition. — Thorax with nine radial ribs, three of which are the primary beams, ithe other six being secondary and interpolated. • 9. Setliophormis rotula, u. sp. (PL 57, fig. 9). Enneaphormis rotula, Haeckel, 1881,. Prodromus et Atlas, pi. Ivii. fig. 9.. CephaUs very large, flat, cap-shaped, trilobed, with irregular, polygonal network. Horizontal •edllar-ring stout, hexagonal, with three lai-ger and three alternate smaller sides of half the length. From the middle of the three larger sides arise three horizontal, centripetal, radial beams, which are united in the centre of the collar-septum — the three primary cortinar beams. These are prolonged outside into three centrifugal primary ribs of the thorax. From the six corners of the collar-ring arise six other secondary, thoracic ribs, equal in size and similar in form to the three primary.. Each of these nine equal, straight ribs of the thorax is thickened towards the distal end, and bears at equal distances five pairs of opposite (tangential) lateral branches. The opposite branches of the neighbouring spines become united, and lie nearly horizontally in one plane, so that the flat, dis- coidal thorax is like a nine-angled wlieel with nine equally distant spokes and five concentric, nine- angled rings. Dimensions. — Cephalis 012 diameter, thorax 0'36 diameter. Habitat. — Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms. 10. Sethophormis triluha, n. sp. Cephahs large, hemispherical, distinctly trilobed, with dense, irregular, polygonal network. From the centre of its top diverge three stout arches or semilunar rods, which are curved downwards, and unite with the three horizontal, radial beams of the collar-septum inside the collar-ring. These three parietal arches of the cephalis are much stronger than in the similar preceding species (PI. 57, fig. 9), and between them are placed three vaulted bosoms of the cephahs. The collar-ring and the thorax are of the same form as in the preceding, but possess only four concentric, nine-angled rings. Dimensions. — Cephalis 0'05 long, 0'08 broad ; thorax 0'24 diameter. Habitat.- — North Pacific, Station 244, depth 2900 fathoms. 11. Sethophormis enneastrtmi, n. sp. Cephalis very large, flat, cap-shaped, with hexagonal base, trilobed, of similar form and struc- ture to the two precechng species. The flat,,discoidal thorax has also the same form, with nine stout ribs and five -concentric, nine-angled rings; its forty-five large meshes, however, are not so simjjle REPORT ON THE RADIOLARIA. 1247 as these (PI. 57, fig. 9), but are subdivided into irregular, smaller meshes by interpolated radial beams connecting the concentric rings, dimensions. — Cephalis 01 diameter, thorax OS diameter. Habitat. — North Pacific, Station 253, depth 3125 fathoms. 12. Sethophormis arachnium, u. sp. Cephalis very large, flat, cap-shaped, trilobed, with hexagonal base, of the same structure as in' the three preceding species. The flat discoidal thorax is also similar, and has the same structure as in the preceding species (I'l. 57 fig- 9) J ^'ut the number of concentric, nine-angled rings is raised from five to eight, and in its outer part nine secondary radial beams are interpolated between the nine primaries, so that the peristome has not nine but eighteen corners. Dimensions. — CephaUs 0'08 diameter, thorax 0'4 diameter. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 13. Sethophormis enneactis, n, sp. • Cephalis small, hemispherical, with small, irregular, polygonal pores. Thorax flatly pyramidal, nearly discoidal, with nine prominent, stout ribs, which are connected by numerous (twelve to six- teen) horizontal, nine-angled rings. In the outer half of the thorax there are nine weaker secondary libs interpolated between the nine stronger primaries, and eighteen shorter and feebler tertiary ribs between the former and the latter. Peristome denticulated, nine-angled. Dimensions. — Cephalis 0"03 diameter, thorax 0"08 long, 0'24 broad. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 14. Sethophorims eupilium, n. sp. (PL 56, fig. 9). Sethopyramis exipilium, Haeckel, 1882, Atlas, pi. Ivi. fig. 9. Graspedilium eupilium, Haeckel, 1878, Manuscript. Cephalis very small, hemispherical, hyaline, without pores. Thorax flatly pyramidal, with nine concave, triangular faces and nine little curved, stout, radial beams. Between these are interpolated numerou.s incomplete secondary beams, which are absent in the apical part of the thorax. The radial beams being connected by numerous (thirty to forty or more) horizontal, ring-like threads, a delicate, arachnoidal network with small, quadrangular pores is produced. Peristome nine-angled, with a peculiar vertical gallery, composed of four horizontal, parallel, nine-angled rings, which are con- nected by numerous vertical, parallel bars, therefore with three transverse rows of square pores. This peculiar species is very different from the preceding and may represent a separate genus, Craspedilium. Dimensions. — Cephalis O'Ol diameter, thorax Ol long, 0'25 broad. Habitat. — Central Pacific, Station 27l, surface. 1248 THE VOYAGE OF H.M.S. CHALLENGER. Subgenus 6. Astrophormis, Haeckel. Definition. — Thorax with a variable number of radial ribs (twelve to twenty or more). 15. Setliopho7'mis aurelia, n. sp. (PI. 55, figs. 3, 4). Leptarachnmm aurelia, Haeckel, ] 879, Manuscript et Atlas. Cephalis large, nearly hemispberieal, with irregular, delicate network of small square meshes. Collar-septum with four large meshes, separated by a cross of four bars, opposite in pairs. Thorax flatly campanulate, with delicate, subregular, hexagonal meshes, and twenty-four prominent radial riljs ; four of these are primary or perradial (centrifugal prolongations of the four bars of the collar- septum) ; four others are interradial or secondary, alternating with the former at angles of 45°: sixteen others are adradial or tertiary, interpolated between the first and second more or less irre- gularly. In some specimens the disposition of the twenty-four ribs was more regular, in others more irregular, than in the specimen figured (figs. 3, 4). The central capsule (fig. 4) exhibits a flat, cap- shaped part with the nucleus (enclosed in the cephalis), and four large, pear-shaped lobes protruded through the four large collar holes (somewhat deformed in the preparation figured). The wall of the thorax ex'hibits at the base four larger, nearly semicircular pores, bisected by the four primary thoracic ribs. Peristome with twenty-four indentations (between the prominent distal ends of the twenty-four ribs), often more distinct than in the specimen figured. Dimensions. — Ce]jhalis 0-03 long, 0-08 broad ; thorax 01 to 0-2 long, 0-4 to 0-6 broad. Hahitat. — Central Pacific, Station 263 to 274, depth 2350 to 2925 fathoms. 16. Sethojihormis dodecaster, u. .sp. (PI. 56, fig. 12). Cephalis small, flatly cap-shaped, with irregular, small, roundish pores. Thorax flatly conical, nearly of the same shape as in the preceding species, but only with twelve prominent ribs ; four primary or perradial ribs (as prolongations of the four crossed cortinar bars), and eight adradial libs interpolated between the former, and arising at some distance from the collar ring. Peristome with twelve prominent pointed lobes (supported by the distal ends of the twelve ribs), and with twelve semicircular bosoms between them. (The specimen figured is young and not fully developed.) Dimensions. — Cephalis 0"02 long, 0'04 broad ; thorax 01 long, 0'3 broad. Hahitat. — South Pacific, Station 298, depth 2225 fathoms. 17. Setlwphormis umb.rella., n. sp. (PI. 70, figs. 4, 5). Cephalis large, flatly cap-shajDcd, with irregular, small polj'gonal meshes. Thorax fiat, umbrella- shaped, with subregular, hexagonal meshes, and sixteen strong radial ribs. Four of these are per- radial, and centrifugal prolongations of the four crossed collar beams ; four others are interradial, and REPORT ON THE RADIOLARIA. 1249 arise, alternating with llie former, directly from the horizontal collar ring ; eight ribs are adrailial or tertiary, anil arise in pairs from the four large perradial basal arches of the thorax, which become bisected by the four primary ribs. Peristome irregularly denticulate. Dimensions. — Cephalis 0'02 long, 0'06 broad ; thorax 012 long, 0*32 broad. Habitat. — North Pacific (off" Jaimn), Stations 236 to 239, surface. 18. Sethophormis fioscula, n. sp. Cephalis small, hemispherical, with subregular, small hexagonal pores. Thorax flatly conical, with larger hexagonal meshes and twenty-four ribs ; four of these are perradial and prolongations of the four collar bars; four iuterradial arise from the collar ring between the former, alternating with them. Each of these eight main ribs gives off two more or less irregular, lateral branches (one at each side), altogether sixteen. The thorax is similar to Cladaraxihnium ramosum (PI. 55, fig- 5), whilst the cephalis is quite different. Peristome with twenty-four prominent triangular lobes. Dimensions. — Cephalis 0-02 long, O'OS broad ; thorax O'l long, O'-lr broad. Habitat. — South Atlantic, Station 325, surface. 19. Sethophormis leptoscenimn, n. sp. Cephalis very small, spherical, with few small, circular pores. Thorax flatly conical or tent- shaped, with concave lateral outlines, small hexagonal meshes, and numerous (thii-ty to forty or more) strong, little curved, simple radial ribs. Peristome nearly circular, with a corona of small, irregular, conical spines. Dimen.'iions. — Cephalis 0-015 diameter ; thorax 0-07 long, 0'2G broad. Habitat. — Indian Ocean, Madagascar (Piabbe), surface. 20. Sethophormis leptopilium, n. sp. Cephalis very small, subsplierical, hyaline, without pores. Tliorax flatly conical or hat-shaped, with concave lateral outlines, and a very delicate network of small square meshes (similar to Litharachnium araneosum, PI. 55, fig. 8). This is supported by thuty-two curved radial ribs, four of which are primary, four secondary, and the other twenty-four interpolated. Peristome horizon- tally expanded and little recurved, like the reflexed brim of a hat. Dimensions. — Cephalis 012 diameter ; thorax 0'08 long, 0'24 broad. Habitat. — South Pacific, Station 291, depth 2250 fathoms. Geuus 559. Sethamphora,^ n. gen. Definition.—^ ethophormida (vel Dicyrtida multiradiata aperta) with numerous curved ribs in the wall of the ovate thorax, the small mouth of which is constricted. Cephalis without horn. ' Sethamphora = Sieve-pitcher ; a-/iiu, «^(Joffi/'f. (ZOOL. CHALL. EXP. PART XL. 1886.) El 157 1250 THE VOYAGE OF H.M.S. CHALLENGER. The genus Sethamphora difiers from the preceding Sethophormis, and from the next following ribbed Sethophormida, mainly in the small, more or less constricted mouth ; therefore the thorax is more or less ovate, and its ribs curved, with the convexity external. Sethophormis may be divided into two different subgenera, DicUjoprora and Cnjpto- cephalus ; in the former the cephalis is perfectly free and well developed, in the latter it is more or less hidden in the uppermost part of the thorax (like Carpocanium). Subgenus 1. Dictyoprora, Haeckel, 1881, Prodromus, p. 430. Definition. — Cephalis large, perfectly free, not hidden in the thorax. 1. Sethamphora hexapleura, n. sp. Shell ovate, smooth, with distinct collar stricture. Length of the two joints = 3 : 11, breadth = 5:10. Cephalis large, free, hemispherical, with small circular pores. Thorax truncate, ovate, with six strong curved ribs, and six large triangular meshes between them in the upper half ; five smaller pores between every two ribs in the lower half (in three tiers) ; therefore, together, tliirty-six thoracic meshes. Mouth strongly constricted, smooth, only one-third as broad as the thorax. Dimensions. — Cephalis 0-03 long, 0-05 broad ; thorax. Oil long, 01 broad. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Sethamjyhora enneapleura, n. sp. Shell subovate, smooth, with slight collar stricture. Length of the two joints = 3:9, breadth = 4 : 8. Cephahs large, hemispherical, fi-ee, with small circular pores. Thorax mflated, ovate, with nine strong curved ribs, which are connected by five transverse circular rings at equal distances. Forty-five rounded, squarish, large meshes between them, in five transverse and nine longitudinal rows. Mouth constricted, smooth, half as broad as the thorax. Dimemions. — Cephalis 0-03 long, 0-04 broad ; thorax 0-09 long, 0-08 broad. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 3. Sethamphoixi dodecapleura, n. sp. Shell urceolate, smooth, with sharp collar stricture. Length of the two joints = 3:9, breadth = 5:9. Cephalis flat, cap-shaped, free, with twelve ribs, and very small pores between them. Thorax thick-walled, inflated, with subcylindrical cavity, and twelve prominent sharp ribs, alternating with twelve longitudinal rows of very small circular pores (eight pores in each row). Mouth con- stricted, half as broad as the thorax. Dimensions, — Cephalis 0-03 long, 0-05 broad ; thorax O'OO long, 009 broad. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. REPORT ON THE RADIOLARIA. 1251 4. Sethamphora mongolfieri, Haeckel. Eucyrtidium mongnljieri, Ehrenberg, 1854, Mikrogeol., Taf. xxxiv. fig. 18; Abhandl. d. k. Akad. d. Wiss. Berlin, 1S75, p. 72, Taf. x. fig. 3. Shell urceolate, smooth, with distinct collar stricture. Length of the two joints = 2 : 9, breadth = 3:7. Cephalis campanulate, with eighteen ribs and small pores. Thorax nearly ellipsoidal, witli eighteen prominent ribs, and eighteen longitudinal rows of regular circular pores between them (eight pores in each row ; therefore 144 pores altogether). Mouth constricted, only one-third as broad as the thorax. Dimeiisions. — Cephalis 0-02 long, 0"03 broad ; thorax b'09 long, 0-07 broad. Habitat. — Fossil in Rarbados. 5. Sethamphora costata, n. sp. Shell urceolate, smooth, very similar to the preceding species ; also with eighteen longitudinal ribs, but differing in the larger size of the cephalis and its pores, and in the more slender and ovate form of the thorax. Length of the two joints = 5 : 10, breadth = 5:8. Pores of the cephalis more numerous. Mouth half as broad as the thorax. Di7nensio7is. — Cephalis 0'05 long, O'Oo broad ; thorax 01 long, 0'08 broad. Halitat. — Central Pacific, Stations 265 to 274, depth 2350 to 2925 fathoms. 6. Sethamphora serrata, n. sp. Shell ovate, spinulate, without external collar stricture. Length of the two joints = 1:6, breadth = 2:4. Cephalis flat, cap-shaped, with small circular pores. Thorax ovate, truncate, with eighteen seiTate longitudinal ribs, alternating with eighteen longitudinal rows of short and broad rather oblong pores (twenty to thirty pores in each row). Mouth strongly constricted, only one-fourth as broad as the thoi'ax. Dimensions. — Cephalis 0'02 long, 0-04 bi'oad ; thorax 0-12 long, 0-08 broad. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 7. Sethamphora ojnpulla, Haeckel. Eucyrtidium ampulla, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 15; Ahliandl. d. k. Akad. "d. Wiss. BerhD, 1875, p. 72, Taf. x. figs. 11, 12. Shell broad, urceolate, spiny, with sharp coUar stricture. Length of the two joints = 1:4, breadth = 1:5. Cephalis subspherical, with few small pores (in figs. 12a and 12& of Ehrenberg, loc. cit., broken off, so that the four pores of the cortinar septum appear). Thorax inflated, bottle-shaped, with twenty prominent, sharply dentate ribs, alternating with twenty longitudinal rows of circular pores (about eight pores in each row). Mouth flat, constricted, one-third as broad as the thorax. Dimensions. — CephaHs 0025 long, 003 broad ; thorax 0"1 long, 044 broad. Habitat. — Fossil in Barbados. 1252 THE VOYAGE OF H.M.S. CHALLENGEE. 8. Sethamphora aerostatica, Haeckel. Podocyrtis aerostatica, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xvi. fig. 4. Shell broad, urceolate, smooth, with sharp collar stricture. Length of the two joints = 2:6, breadth = 3:8. Cephalis hemispherical, large, with few pores (broken off in fig. 4a of Ehrenberg, so that the six collar pores appear). Thorax inflated, bottle-shaped, with twenty-two to twenty-four smooth prominent ribs, alternating with the same number of longitudinal rows of small circular pores. Mouth very small, strongly constricted, scarcely as broad as the cephalis, with three short teeth. Dimensions. — Cephalis 0-02 long, O'OS broad; thorax 0-06 long, 0-08 broad. Habitat. — Fossil in Barbados. Subgenus 2. Cryptocephalus, Haeckel, 1881, Prodromus, p. 430. . Definition. — Cephalis more or less hidden in thorax, being partly enveloped by its uppermost part. 9. Sethamphora microstoma, n. sp. (PI. 57, fig. 5). Cryptoprora microstoma, Haeckel, Atlas, pi. Ivii., fig. 5. Shell ovate, smooth, without external collar stricture. Length of the two joints = 1:6, breadth = 2 : 4. Cephalis flat, cap-shaped, without ribs, with small circular pores. Thorax ovate, with twenty- four prominent ribs, alternating with deep longitudinal furrows, each of which contains a series of about fifteen small circular pores. Mouth very small, representing a short cylindrical tube, which is only one-eighth as broad as the thorax. Dimensions. — Cephalis 0'02 long, 004 broad ; thorax 012 long, 0-08 broad. Habitat. — Western Tropical Pacific, Station 220, depth 1100 fathoms. 10. Sethamphora favosa, n. sp. (PI. 57, fig. 4). Cryptocephalus favosus, Haeckel, 1881, Prodromu.s, p. 430. Shell ovate, dimply. Length of the two joints = 1:5, breadth = 1:5. Cephalis subspherical, small, completely hidden in the thickened top of the thorax (but very distinct ia the longitudinal section). Thorax ovate, with twenty-five to thirty longitudinal ribs, alternating with the same number of longitudinal furrows, each of which contains ten to twelve circular, hexagonally framed pores. In the smooth wall of the peristome only twelve triangular ribs are visible. Mouth constricted, one-third as broad as the thorax. Difnensions. — Cephalis 0-02 diameter ; -thorax 01 long, O'OO broad. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. REPORT ON THE RADIOLARIA. 1263 Genus 560. Sethopyramis,^ Haeckel, 1881, Prodromus, p. 432 (sensu emendato !) Definition. — Se t h op h or m i da (vel Dk-yrtida multiradiata aperta) with nume- rous straight or slightly curved radial ribs in the wall of the pyramidal thorax. Net- work simple. Cephalis commonly without horn. The genus Sethopyramis and the four following genera form together a peculiar small group (SethopjTamida), characterised by the slender pyramidal shell, in the wall of which numerous (six to nine or more) radial ribs are enclosed. These ribs may be regarded as the terminal feet of a CalpophcBna or Halicalyp>tra, which become connected by transverse bars. Sethopyramis may be derived also directly from Patagospjyris by loss of the primary sagittal ring and reduction of the cephahs. Subgenus 1. Sestropyramis, Haeckel. Definition. — PjTamidal shell with six radial main beams (sometimes also five or seven, as individual varieties). 1. Sethopyramis scalaris, Haeckel. Cornutdla scalaris, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. iL fig. 1. Shell smooth, .slenderly pyramidal, hexagonal. Cephalis large, subglobular, hyaline, without pores (or with very small and scarce pores). Thorax with six straight (or httle curved) stout longitudinal ribs or radial beams, which are connected by twenty to thirty complete, hexagonal, horizontal rings. The large meshes so produced are regular, square, their length and breadth equally and gradually increasing towards the mouth. Dimensions. — Cephalis 0'04 diameter ; thorax (with twenty-four transverse rings) 0'4 long, 0"15 broad at the mouth. Habitat. — Fossil in Barbados. 2. Sethopyramis hexalactis, n. sp. Shell thorny, of the same form as, and similar structure to, the preceding species, but differing in the spiny surface and the smaller subglobular cephalis, which bears small circular pores and an obhque conical horn twice the length. The whole surface is covered with short conical thorns. Dimenstons. — Cephalis 0'02 diameter ; thorax (with twenty transverse rings) 0"25 long, 01 broad. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. Subgenus 2. Cep)halop}yramis, Haeckel, 1881, Prodromus, p. 432. Definition. — Pyramidal shell with nine radial main beams (sometimes also eight or ten, as individual varieties). 1254 THE VOYAGE OF H.M.S. CHALLENGER. 3. Sethopyramis enneactis, n. sp. (PL 5Q, fig. 7). Gephalcypyramis enneactis, Haeckel, 18S1, Prodromus et Atlas, pi. Ivi. fig. 7. Shell smooth, slender, pyramidal. Cephalis large, ovate, with pointed apex, nearly hyaline, with very few and small scattered pores. Thorax very slenderly pyramidal, with straight lateral outUnes, and nine stout and straight radial beams, which are connected by fifteen to twenty horizontal complete rings. Meshes subregular, square, simple, without secondary network ; their length and breadth equally increasing towards the mouth. Dimensions. — Cephalis 0'05 long, 0'03 broad ; thorax (with twenty transverse rings) 0'24 long, 01 broad at the mouth. Habitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms. 4. Sethopyramis quadrata, n. sp. (PL 54, fig. 2). Shell smooth, slenderly pyramidal, very similar in form and structure to the preceding species ; differing from it in the rudimentary cephalis, which is very small, hemispherical, with few small porules. The three internal cortinar Ijars of the collar stricture are present ; when they become lost this species passes over into Bathropijramis quadrata (PL 54, fig. 1). Dimensions. — Cephalis O'Ol long, 0'02 broad ; thorax (with ten transverse rings) 0"15 long, O'l broad at the mouth. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 5. Sethopyramis quadratella, Haeckel. Conmtella quadratella, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. ii. fig. 2. , Litharachnium quadratella, Biitsclili, 1882, Zeitschr. f. Ts'i.ss. ZooL, vol. xxxvi. p. 540, Taf. xxxiii. fig. 37. Shell smooth, broadly pyramidal. Cephalis ovate, small, blunt, hyaline, with very few and small pores (in the figure of Ehrenberg broken off). Thorax broadly pyramidal, with straight lateral out- lines, and nine stout and straight radial beams, which are connected by eight to twelve horizontal complete rings. Meshes in the upper half regular, square, in the lower half broad, rectangular (in the tenth transverse I'ow twice as broad as long). Dimensions. — Cephalis 0"03 long, 0'02 broad ; thorax (with ten transverse ring^ 0-15 long, 0"15 broad. Hahitat. — Fossil in Barbados. 6. Sethopyramis trapezoides, n. sp. Shell smooth, broadly pyramidal. Cephalis large, ovate, liyaluie, without pores ; its collar septum exhibits distinctly the four collar pores (two larger cardinal and two smaller jugular pores). REPORT ON THE RADIOLARIA. 1255 Thorax broad, pyramidal, with slightly concave lateral outlines and nine (sometimes eight or ten) curved ribs, which are connected by eighteen to twenty-four complete transverse rings. The large meshes, so produced, have the form of a parallel trapezoid, and are in the eighth transverse row three times as broad as long. (Differs from Batliropyramis trapezoides, PL 54, fig- 3, mainly by the possession of a well developed cephalis). Dimensions. — Cephalis 0-04 long, 0'03 broad ; thorax (with eighteen rings) 0'32 long, 0'24 broad. Habitat. — South Pacific, Station 285, depth 2375 fathoms. 7. Sethopyramis spinosa, n. sp. Shell thorny, slender, pyramidal. Cephalis small, subspherical, with few small pores and a straight, vertical, conical horn twice the length. Thorax with nine straight ribs, which are con- nected by sixteen to twenty complete transverse nine-angled rings. The large meshes so produced are subregular, square. From each nodal point a short conical spine arises. (Differs from the similar Bathropyramis spiriosa, PI. 54, fig. 4, by the development of the cephalis and the simple pointed, unforked spines.) Dimensions. — Cephalis 0-03 diameter ; thorax (with sixteen rings) 0'2 long, 012 broad. Habitat. — Central Pacific, Station 263, depth 2650 fathoms. 8. Sethopyramis hexagonalis, n. sp. Shell papillate, slender, pyramidal. Cephalis small, hemispherical, with a straight conical horn twice the length, and small circular pores. Thorax conical, with slightly convex outlines and nine stout, somewhat curved ribs in zig-zag form, which are connected by ten to twelve interrupted transverse bars. From each nodal point a small conical papilla arises. The large meshes so pro- duced are regular, hexagonal, gradually increasing in size towards the mouth. Dimensions. — Cephalis 0'03 diameter ; thorax (with twelve transverse rows of meshes) 0'18 long, 012 broad. Habitat. — South Atlantic, Station 335, depth 1425 fathoms. 9. Sethopyrami.s cydomma, n. sTp. Shell thorny, slender, pyramidal. Cephalis large, subspherical, with numerous very small circular pores, and a small conical horn of the same length. Thorax similar in form and structure to that of the preceding species ; but each hexagonal mesh is provided with a very thin circular hyaline ring (like a diaphragm), so that the openings are not hexagonal, but circular. From each nodal point a short pointed conical or slightly forked spine arises. Dim.ensions. — Cephalis 0'02 diameter ; thorax (with ten transverse rows of meshes) 018 long, 014 broad. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 1256 THE VOYAGE OF H.M.S. CHALLENGER. Subgenus 3. Actinopyramis, Haeckel. Definition. — Pyramidal shell with twelve or more radial beams (commonly twelve to twenty-four, sometimes forty or more). 10. Sethopyramis dodecalactis, n. sp. Shell Smooth, slender, pyramidal. CephaUs small, spherical, hyahne, with a short conical horn. Thorax with twelve radial ribs in the upper half, between which twelve others are interpolated in the lower half. These are connected by twenty to twenty-four complete transverse rings. The meshes so produced are subregular, rectangular. Dimensions. — Cephalis 0'03 diameter ; thorax 0'6 long, 0'2 broad. Habitat. — Indian Ocean, Madagascar (Eabbe), surface. 11. Sethopyramis hicornis, n. sp. Shell spiny, slender, pyramidal. Cephalis small, spherical, hyaline, with two di^'ergent conical horns, the major (occipital) three times and the minor (frontal) twice as long. Thorax slender, pyramidal, campanulate, thorny, with twenty to thirty radial beams, which are little curved, convex in the upper, concave in the lower half, and connected by numerous interrupted transverse bars. Meshes in the upper third rounded, in the lower two-thirds quadrangular, of very different sizes. Surface covered with spinules. Bimcnsions. — Cephalis 0'02 diameter; thorax 0'9 long, 0'4 broad. Habitat. — North Pacific, Station 241, depth 2300 fathoms. 12. SetJiopyramis maxima, u. sp. Shell smooth, slender, pyramidal. Cephalis small, spherical, with few small pores, and a stout, vertical, conical horn twice the length. Thorax very prolonged, conical, with straight lateral out- lines and numerous (twenty to fifty) radial beams (in the upper third twelve, in the middle third twenty-four, in the lower third forty to fifty, by interpolation); they are connected by very numerous interrupted transverse bars. Meshes subregular, quadrangular. Surface smooth. Dimmisions. — Cephahs 0'02 diameter ; thorax 1-05 long, 0'45 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 561. Plectopyramis,^ Haeckel, 1881, Prodromus, p. 432. Definition. — S e t h o p h o r m i d a (vel Dicyrtida multiradiata aperta) with numerous straight or slightly curved radial ribs in the wall of the pyramidal thorax. Network double, the large primary meshes being fenestrated by fine secondary network. Cephalis commonly without horn. ' FUctopyrainis = Woven pyramitl ; •K'hixTog, Tcv^a^ii. REPORT ON THE RADIOLARIA. " 1257 The genus Plectopyramis differs from the preceding Setho2')yramis, its ancestral form, only in the peculiar double fenestration of the shell, the large primary meshes of which are separated bj' strong bars, and filled up by a very delicate arachnoidal network, com- posed of small pores and very thin threads between them. This double lattice-work often exhibits a very remarkable regularity. As in the preceding genus, the number of radial ribs is commonly six or nine, rarely twelve to twenty or more. Subgenus 1. Hexapleuris, Haeckel. Definition. — Pyramidal shell with six radial main beams (sometimes five or seven in individual varieties). 1. Plecto])yramis magnifica, Haeckel. Polycystina magnifii-a, Bury, 1862, Polycystins of Barbados, pi. xi. fig. Shell smooth, slender, pyramidal. Cephalis large, ovate, pointed, separated from the thorax by a very deep collar stricture, with few irregular pores. Thorax with six strong and straight radial beams, which are connected by about twenty horizontal, hexagonal rings. The large meshes so produced are regidar, square, and filled up by an extremely delicate secondary arachnoidal net- work, composed of regular square pores (as in PI. 54, figs. 7, 8). Divunsions. — Cephalis 0-06 long, 0-04 broad ; thorax (with twenty transverse rings) 0'4 long, .0-12 broad. Habitat. — Fossil in Barbados. 2. Plectopyramis hexapleura, n. sp. Shell thorny, slender, pyramidal. Cephalis large, ovate, blunt, with deep collar stricture. Thorax with six strong and straight radial beams, which are connected by numerous (twenty to thirty) interrupted transverse bars. The large meshes so produced are irregular, quadrangular, and filled up by irregular, delicate, secondary network, with small polygonal pores. Dimensions. — Cephalis O'OS long, 0-03 broad ; thorax 0-3 long, 01 broad. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. Subgenus 2. Enneapjleuris, Haeckel. Definition. — Pyramidal shell with nine radial main beams (sometimes eight or ten in indi\ddual varieties). (ZOOL. CHALL. EXP.— PART XL. — 1886.) Er 158 1258 THE VOYAGE OF H.M.S. CHALLENGER. 3. Plectojyyramis dodecomma, n. sp. (PL 54, fig. 6). Shell smooth, slenderly pyramidal, with straight outlines. CephaHs conical, obtuse, with thirty-six small square pores (in nine divergent longitudinal rows, each of four pores). Collar septum (be- tween cephalis and thorax) with four distinct collar pores. Thorax pyramidal, with nine very stout and straight angular radial beams, which are connected by ten to fifteen broad horizontal nine- angled rings. Each of the large regular, square meshes so produced contains a very delicate fenestra- tion, witli twelve regular, square pores, separated by two transverse and three longitudinal crossed threads. A very regular and remarkable structure. Dimensions. — Ce^jhalis 0"03 long, 0'02 broad; thorax (with ten rings) 0'2 long, 0'15 broad. Huiitat. — Central Pacific, Station 271, depth 2425 fathoms. 4. Plectopyramis (juadratomma, u. sp. Shell smooth, slenderly pyramidal. Cephahs large, ovate, hyaline, with few very small basal pores and deep collar stricture. Thorax pyramidal, with straight outline, and nine very stout and straight radial beams, which are connected by fifteen to twenty horizontal nine-angled rings. Each of the large regular, square meshes so produced is filled up by a very delicate arachnoidal network, with very numerous and small square pores (as in the similar Ci^iclopi/ramis infundihulum, PI. 54, fig. 7, which differs in the loss of the cephalis). Dimensions. — Cephalis 0'05 long, 0-03 broad ; thorax (with fifteen rings) 0'32 long, 0-2 broad. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 5. Plectopyramis trapezomma, n. sp. (PL 54, fig. 8). Shell smooth, broadly pyramidal, with concave lateral outlines. Cephalis hemispherical, small, with numerous small, circular pores. Thorax pyramidal, with nine stout, concavely curved radial beams, which are connected by twelve to sixteen horizontal nine-angled rings. The large meshes so produced are in the upper half square, in the lower half parallel trapezoid (in the fifteenth ring three times as broad as long), and filled up by a secondary arachnoidal network, with very numerous and small square pores. Dimensions.— Ge-\)\\?i\\s 0'015 long, 0-025 broad ; thorax (with fifteen rings) 0'22 long, 0'2 broad. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 6. Plectopyramis polygonomma, n. sp. Shell smooth, pyramidal, very similar to the preceding species ; differing from it in the irregular shape of the delicate polygonal (not tetragonal) secondary network, filling up the large rectangular meshes. The cephalis is larger, hyaline, pear-shaped, pointed, without pores, with a deep collar stricture. The nine radial beams of the thorax are less concave. Dimensions. — Cephalis 0-04 long, 0-03 broad ; thorax (with fifteen rings) 0-3 long, 0-22 broad. Habitat. — South Pacific, Station 295, depth 1500 fathoms. REPORT ON THE RADIOLARIA. 1259 7. Phctopyramis heteromma, n. sp. Shell smooth, slenderly pyramidal, witli concave outlines. Cephalis very small, subspherical, with a small oblique, conical horn, and very small, scarce circular pores. Thorax with nine stout con- cavely curved radial beams, which are connected by numerous (thirty to fifty or more) interrupted transverse bars. Tlie large irregular meshes so produced are filled up by irregular, polygonal, deUcate lattice-work. IHmensions. — Cephalis 0*02 long, 0'02 broad ; thorax 0'6 long, Oo broad. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 8. Plectopyramis serrata, n. sp. Shell thorny, slenderly pyramidal, with straight outlines. Cephalis very small, spherical, with a long oblique, conical horn, and very small cu'cular pores. Thorax with nine stout, straight, regularly serrate ribs or radial beams, which are connected by numerous (twenty to thirty or more) inter- rupted transverse bars. The latter, being crossed by intercalated and interrupted irregular radial beams, produce a subregular secondary network of rectang-ular meshes of different sizes. Dimensions. — Cephalis 0'02 long, 0"02 broad ; thorax, 0"3 long, 0"2 broad. Habitat. — South Pacific, Station 298, depth 2225 fathoms. 9. Plectopyramis fenestrata, Haeckel. Pyramis fenestrata, Buiy, 1862, Polycystins of Barbados, pi. xxi. fig. 8. Shell thorny, broadly pjTamidal, with straight outlines. Cephalis very small, spherical, hyaline. Thorax with nine stout, spinulate, straiglit ribs or radial beams, which are connected by ten to fifteen transverse bars, which in the upper half are complete rings, in the lower half interrupted, and crossed by irregularly intercalated radial beams. Meshes therefore irregular, quadrangular. All the bars are thorny. Dimensions. — Cephalis O'Ol diameter; thorax 0"2 long, 0'16 broad. Habitat. — Tropical Atlantic. 10. Plectopyrami'i furcata, n. sp. Shell spiny, slenderly pyramidal, with straight outlines. CephaKs small, spherical, with few- small pores. Thorax with nine stout and straight spinulate ribs, which are connected by a variable number of irregular interrupted transverse bars ; the large quadrang-ular meshes so produced are fiUed up by irregular delicate network. The entire surface of the thorax is covered with short forked spines. Dimensions. — Cephalis 0'02 diameter ; thorax 0'3 long, 0'2 broad. Habitat. — Indian Ocean (Zanzibar), Pullen, depth 2200 fathoms. 1260 THE VOYAGE OF H.M.S. CHALLENGER. Subgenus 3. Polypleuris, Haeckel. Definition. — Pyramidal shell with numerous (twelve or more) radial main beams (commonly twelve to eighteen, sometimes twenty to thirty or more). 11. Plectopyr amis poly pleura, n. sp. (PL 56. fig. 8). Shell smooth, slenderly conical, with straight outlines. Cephalis small, subspherical, with very small dot-like pores, and an oblique conical horn twice the length. Thorax with numerous (twenty to thirty) divergent longitudinal ribs ; usually twelve of these radial beams appear as stronger, primary main ribs, and twelve to eighteen other as secondary, feebler, interpolated ribs. They are crossed by numerous (twenty to forty or more) horizontal rings. The large meshes so produced are quadrangular, and partly filled up by a very delicate secondary network, with small square pores. Dinnensions. — Cephalis 0"03 diameter ; thorax 0'36 long, 0"24 long. Habitat. — Central Pacific, Station 267, depth 2700 fathoms. 12. Plectopyramis lagena, n. sp. Shell smooth, wine-bottle shaped, or slenderly conical-campanulate, with bent outlines, which are concave in the upper, convex in the lower half. Cephahs very small, spherical, hyahne, without pores. Thorax with twenty-four radial ribs, twelve stronger primary, alternathig with twelve feebler secondary. They are crossed by interrupted transverse bars. The irregular quadrangular meshes so produced are filled up by a delicate, irregular, secondary network. Dimensimis. — Cephalis 0'02 diameter; thorax 0-5 long, 0'3 broad. HaUtat. — South Atlantic, Station 335, depth 1425 fathoms. Genus 562. Spongopyramis^ n. sp. Definition. — S e t h o p h o r m i d a (vel Dicyrtida multiradiata aperta) with numerous straight or slightly curved radial ribs in the wall of the pyramidal thorax. Network spongy. Cephalis commonly without horn. The genus SjMngopyramis has arisen from Sethopyramis by development of an irregular spongy framework around the lattice-shell, and is one of the small number of C y r t o i d e a in which the shell- wall exhibits a spongy structure. In both observed species the cephalis is small, but evident. REPORT ON THE RADIOLARIA. 1261 1. Spongopyramis spongiosa, n. sp. (PL 56, fig. 10). Plectopyramis spongiosa, Haeckel, 1881, Prodromiis et Atlas, loe. cit. Shell partly or entirely enveloped by spongy framework, slender, pyramidal, with rather straight outlines. CephaUs very small, ovate, hyaline. Thorax with nine very stout and nearly straight ribs, which are connected by fifteen to twenty or more irregular, interrupted transverse bars. The irregular quadrangular meslies so produced are filled up by an irregidar secondary network, with meshes of very different size and form. The dense spongy envelope, which in the specimen figured covered only half the shell, was complete in another older specimen. DiTnensions. — Cephalis 0'015 long, O'Ol broad; thorax 0"4 long, 0'25 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 2. Spongopyramis spongoplecta, n. sp. Shell entirely enveloped by spongy framework, pyramidal, with straight outlines. Cephalis ovate (twice as large as in the preceding species), with small circular pores. Thorax with twelve stout and straight ribs, which are connected by twenty to twenty-five annular, transverse bars. The subregular square meshes so produced are filled up by irregular, spongy network, which envelops the whole shell more loosely than in Spongopyramis spongiosa. Dimensions. — Cephalis 0'03 long, 0'02 broad ; thorax O'o long, 0'2 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. Genus 563. Acanthocorys,^ Haeckel, 1881, Prodromus, p. 432. Definition. — S etliophormicla (vel Dicyrtida multiradiata aperta) vs^ith numerous radial ribs in the wall of the pyramidal thorax, prolonged into divergent terminal feet. Network simple. Cephalis commonly with several horns. The genus Acanthocorys and the following nearly allied Arachnocorys possess a near relation to the three preceding pyramidal genera, but differ from them in the terminal pro- longation of the radial ribs, which are commonly spiny and form a corona of free feet around the mouth of the thorax. The cephalis is usually much larger than in the three preceding genera, and bears a variable number of radial horns. Therefore these two genera are probably older and nearer to the common ancestral form of the Sethophormida than the preceding genera. It may be derived directly from Bictyophimus by inter- polation of three secondary (interradial) ribs between the three primary (perradial) ribs. 1 Acanthocorys = S^my helmet ; xxxudec, k6(vs. 1262 THE VOYAGE OF H.M.S. CHALLENGER. Subgenus 1. Acanthocorallium, Haeckel. Definition. — Thorax with six divergent ribs or radial beams (three primary or perradial alternating with three secondary or interradial). 1. Acanthocorys hexapodia, n. sp. Cephalis large, ovate, with subregular hexagonal pores, and six strong, conical, simple, divergent horns of the same length. Thorax flat, conical, smooth, with six large triangular basal holes, sepa- rated by six strong, prismatic, smooth beams, which are connected only near the distal end by a hexagonal ring of delicate, irregular network. CoUar septum with three meshes, separated by the three centripetal prolongations of the three primary ribs. Dimensions. — Cephalis 0-05 long, 0'04 broad ; thorax 012 long, 0'24 broad. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 2. Acanthocorys pristipodia, n. sp. Cephalis large, hemispherical, with irregular, polygonal pores, and numerous (ten to twenty) bristle- shaped, radiating horns, which are conical at the base, and twice as long. Thorax flatly campanulate, thorny, with six strong, serrate or spinulate, divergent, radial rihs, prolonged into six. free conical feet of the same length. Meshes of the thorax irregular, polygonal, a corona of six larger ones at the base. Collar septum with four meshes, shaped as in PI. 56, fig- 6. Dimensions. — Cephalis 0'04 long, 0'06 broad ; thorax 0'08 long, 0'18 broad. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 3. Acanthocorys macropodia, u. sp. Cephalis small, subspherical, with irregular, roundish pores .and numerous small, bristle-shaped horns. Length of the two joints =1 : 2, breadth =1 : 6. Thorax sexangular, pyramidal, with six very long and straight, widely divergent feet, which are prismatic and spiny, and three to five times as long as the breadth of the shell. Only the upper third of the six ribs is connected by irregular, roundish network, with six large triangular holes at the base. CoUar septum with four meshes which have the same relation to the six ribs as in SetJwpJiormis hexalactis (PI. 56, fig. 6). Dimensions. — Cephalis 0'025 diameter, thorax 0'G5 long, 015 broad. Habitat. — Central Pacific, Station 271, surface. 4. Acanthocorys hictschlii, Haeckel. 1 Clathroeanium ehrenhergii, Biitschli, 1882, Zeitschr. f. wiss. ZooL, vol. xxxvL pp. 514, 539, Taf. xxxii. fig. 18, a, h. Cephalis large, subs]3herical, with numerous small, circular pores and three to six divergent, slender, apical horns. Thorax flatly conical, smooth, not much larger than the cephalis, with six REPORT ON THE RADIOLARIA, 12G3 large, triangular or ovate basal holes between the six ribs. Three of these ribs are primary or perradial, and arise immediately from the collar septum, alternating with three secondary or inter- radial ribs, which arise more outside. The specimen observed by me exhibited six apical horns, and was more complete than that figured by Blitschli, the six ribs being prolonged over the con- necting lattice-girdle into six short, divergent feet. Dimensions. — Cephalis 0'06 long, 0"06 broad ; thorax 0'08 long, 0"1 broad. Habitat. — Fossil in Barbados. Subgenus 2. Acanthocoronium, Haeckel. Definition. — Thorax with nine divergent ribs or radial beams, three of which are primary or perradial, the other six secondary or interradial. 5. Acanthocorys umbellifera, Haeckel. Arachnocorys umhelUfera, Haeckel, 1862, Monogr. d. Radiol., p. 305, Taf. vi. fig. 12. Cephalis large, ovate, with subregular, circular pores and numerous divergent, sunple spines of different lengths. Thorax flatly conical, with nine strong, divergent ribs, which in the distal half are free, in the proximal half connected by numerous transverse beams, forming irregular polygonal meshes. Dorsal face of the thorax armed with scattered ascending spines. Dimensions. — Cephahs O'Oo long, 0'035 broad ; thorax 0'05 long, 0"12 broad. Habitat. — Mediterranean (Messina) ; Atlantic, Station 354, surface. 6. Acanthocorys triloba, u. sp. Cephalis large, campanulate, trilobed, with irregular, roundish pores, numerous spines, and a large pyramidal horn on the top, which is connected by three constricted arches with the base of the horizontal collar beams. From the latter arise as centrifugal prolongations three stout, curved, primary ribs of the flatly vaulted thorax, and each of these gives ofi' at the base two opposite, lateral, secondary ribs. These nine ribs are spiny, and connected by irregular, arachnoidal network. Dimensions. — Cephalis 0-05 long, 0'07 broad ; thorax 0"08 long, 0*18 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 7. Acanthocorys enneapodia, n. sp. Cephalis large, ovate, with irregular roundish pores, and numerous divergent, ascending spines. Thorax smooth, conical, little larger, with the same network, and nine larger, triangular holes at the base ; with nine straight, ecpially-disposed ribs, which are prolonged into slender feet twice the length. With these latter alternate nine shorter radial sprues, arising from the truncate peristome. Dimensions. — Cephalis 0'05 long, 0'04 broad ; thorax O'Oo long, 0"09 broad. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathonas. 1264 THE VOYAGE OF H.M.S. CHALLENGER. 8. Acanthocorys macroceras, n. sp. (PI. 97, fig. 12). Cephalis large, hemispherical, spiny, with regular, circular pores, and a very large, cylindrical, vertical horn five times as long as the whole shell. Thorax spiny, campanulate, with irregular, roundish pores and nine strong, curved ribs, prolonged into nine slender, divergent feet twice the length, which are curved, convex in the proxunal half and concave in the distal half. Dimensions. — Cephalis 0'05 long, 0'08 broad ; thorax 012 long, 0'2 broad. Habitat. — South Pacific, Station 298, depth 2225 fathoms. 9. Acanthocorys furcata, n. sp. Cephalis large, subspherical, spiny, with irregular, roundish pores. Thorax flatly conical, thorny, with irregialar, polygonal pores, decreasuig in size towards the mouth, and with nine straight divergent riljs, which at the peristome are forked and prolonged into eighteen slender, very long, bristle-shaped feet. Dimensions. — Cephalis 0'045 diameter, thorax 0"07 long, 0"13 broad. Habitat. — South Atlantic, Station 323, depth 1900 fathoms. Subgenus 3. Acanthocorythium, Haeckel. Definition. — Thorax with a variable number (ten to twenty or more) radial ribs, prolonged into free terminal feet. 10. Acanthocorys dodecaster, n. sp. CephaUs small, subspherical, with small circular pores and a large conical horn of twice the length, and some accessory spines. Thorax thorny, flatly campanulate, with twelve stout curved ribs, which at the peristome are prolonged into twelve slender, curved feet of twice the length ; four of them are centrifugal prolongations of the four cortinar beams separating the four large meshes of the collar septum ; eight other ribs are secondary, interpolated in pairs between the former. At the base of the thorax are twelve large triangular holes between the riljs ; the other network is irregidar, with polygonal meshes. Dimensions. — Cephalis 0'03 diameter, thorax 0"05 long, 012 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 11. Acanthocorys polypodia, n. sp. Cephalis small, hemispherical, with small, roundish pores and divergent radial spines. Thorax flatly conical, spiny, with twenty to twenty-four divergent, straight ribs, which in the proximal REPOET ON THE RADIOLARIA. 1265 third are separated by the same luunher of large, triangular meshes, in the middle third connected by irregular network, in the distal third free. Dimensions. — Cephalis 0-02 long, 0-03 broad ; thorax 0-06 long, CIS broad. Habitat. — Central Pacific, Station 273, depth 2350 fathoms. Genus 564. Arachnocorys,^ Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 837. Definition. — S e t li o p h o r m i d a (vel Dicyrtida multiradiata aperta) with numerous radial ribs hi the wall of the pyramidal thorax, prolonged into divergent terminal feet. Network double, with an arachnoidal outer mantle around the inner lattice -shell. Cephalis commonly with numerous horns. The genus Arachnocorys has been derived from the preceding Acanthocorys, by development of numerous external siliceous threads which connect the radial horns of the cephalis -udth the secondary spines arising from the thoracic ribs. In this way there becomes formed an outer arachnoidal framework, enveloping loosely, like a delicate mantle, the inner primary lattice-shell. Subgenus 1. Arachnocorallium, Haeckel. Definition. — Thorax with six divergent ribs or radial beams (three primary or perradial, alternating with three secondary or interradial). 1. Arachnocorys hexai^tera, n. sp. Arachnocorys circumtexta (juv. ]), R. Hertwig, 1879, Organism, d. Radiol, p. 79, Taf. viii. fig. 2a. Cephalis large, subspherical, with irregular, polygonal pores, and numerous bristle-shaped spines twice the length ; on the centre of the top a single larger vertical horn. Thorax flatly conical, with six strong and straight widely divergent ribs, which in the proximal half are separated by six large holes, in the distal half connected by a broad ring of irregular network. From each rib arises a perpendicular branch, and these branches are connected together, and with the spines of the cephalis, by arachnoidal network. Dimensions. — Cephalis 0'04 diameter, thorax O^OS long, 0'24 broad. Habitat. — Central Pacific, Station 266 ; Mediterranean, surface. 2. Arachnocorys discoides, n. sp. Cephalis small, pyramidal, with irregular, roundish pores and numerous thin spines, on the top a single larger vertical horn. Thorax very flat, nearly discoidal, with six strong and straight ribs, 1 Arachnocorys - helmet with a cobweb ; ifax^ii "-''^"s- (ZOOL. CHALL. EXP. PART XL. — 1886.) Kr 159 126G THE VOYAGE OF H.M.S. CHALLENGER. which by communication of few larger and numerous smaller branches form an irregular network with polygonal meshes. From each of the si.-i ribs arise two or three larger, perpendicular branches of half the length, and from the network numerous smaller spines. All these dorsal spines of the .shell are connected by a dense arachnoidal wicker-work. Dimensions. — Cephalis 0'02 diameter, thorax 0-0-4 long, O'S broad. Habitat. — Central Pacific, Station 271, surface. Subcrenus 2. Arachnocoronium, Haeckel. Definition. — Thorax with nine divergent ribs or radial beams, three of which are primary or perradial, the other six secondary or interradial. (Sometimes eight or ten occur instead of the nine normal ribs.) 3. Arachnocorys cirmimtexta, Haeckel. Arachnocorys circumtexta, Haeckel, 1862, Monogr. d. Radiol., p. 304, Taf. vi. figs. 9-11. Arachnocorys circumtexia, E. Hertwig, 1879, Organism, d. Radiol., p. 78, Taf. viii. fig. 2. Cephalis large, subspherical, with numerous roundish pores, and eight to ten slender, conical horns twice the length. Thorax flatly conical, with nine strong, -straight, widely divergent, conical feet, each of which bears in the middle of its outer side a perpendicular ascending branch of half the length. These branches and the horns of the cephalis are connected by very thin, parallel, arach- noidal threads. Network of the thorax irregular, with nine larger triangular holes at the base. Collar septum with numerous, irregular, roundish pores. Dimensions. — Cephalis 0'04 to O'Oo diameter, thorax 0'08 to 012 long, 015 to 0'25 broad. Habitat. — -Mediterranean (Messina) ; Atlantic, Stations 347 to 354, surface. 4. Arachnocorys enneaptera, n. sp. Cephalis large, campanulate, with irregular, polygonal pores, two larger stout pyramidal and numerous slender, bristle- shaped horns. Thorax of the same structure as in the preceding species, only the nine basal holes are of twice the size ; the lower network denser (as in Clathrocanium diadcma, PI. 64, fig. 2). Collar septum with numerous, irregular, roundish pores. Dimensions. — Cephalis 0'05 diameter, thorax 012 long, 0^22 broad. Habitat. — Tropical Atlantic, Station 338, surface. 5. Arachnocorys araneosa, n. sp. (PL 56, fig. 11). Cephalis large, subspherical, with circular, subregular, hexagonally framed pores, and twenty to thirty slender, cylindrical, straight radial spines. Thorax flatly conical, nearly of the same shape as in the two preceding species, but with nine longer ribs, and more irregular, broader network between them, From the middle of each rib arises, nearly horizontally, a strong branch, which is directed REPORT ON THE RADIOLARIA". 1267 outwards. These branches are connected with the spines of the cephalis as well as with the distal half of the ribs, by dense and delicate arachnoidal network, composed of parallel, very thin, siliceous threads (in fig. 11 only partially represented). Collar septum with numerous irregular, roundish pores. DimcTusions. — Cephalis 0-04 diameter, thorax O'l long, 0-2 broad. Habitat. — Central Pacific, Station 270 to 274, surface. 6. Arachnocorys arachnodiscus, n. sp, Cephalis small, campanulate, conical, with a single very large conical central horn, and numerous smaller accessory spines. Thorax in form and structure similar to that of the three preceding species, but much flatter, being nearly discoidal. The meshes of the network are smaller and more numerous, irregularly polygonal, and the nine basal holes little larger. Collar septum with four large meshes (as in PI. 60, fig. 6). Dime'asions. — Cephalis 0'25 long, 0'3 broad ; thorax 0'04 long, 0'24 broad. Habitat. — North Pacific, Station 248, surface. 7. Arachnocorys trifida, n. sp. Cephalis large, campanulate, with irregular, roundish pores and numerous ramified spines ; in the centre of the top a larger pyramidal oblique horn of twice the length. Thorax cap-shaped, flatly vaulted, with nine strong convex ribs, prolonged into slender free feet. Three of these nine riljs are the centrifugal prolongations of the three cortinar bars (united in the centre of the collar stricture, separating its three large cortinar meshes); the other six are diverging lateral branches of the former, arising in pairs at both sides of its base. All nine ribs are connected by delicate arachnoidal net- work with irregular polygonal meshes. From its surface arise thin bristles, and from the base of each main rib a stout, perpendicular branch. All these dorsal spines are connected l)y irregular, arachnoidal wicker-work, covering thorax and cephalis. (A remarkable primitive species ?) Dimensions. — Cephalis 0'05 long, 0'06 broad ; thorax 0'07 long, 018 broad. Habitat. — Central Pacific, Station 27l, depth 242.5 fathoms. Subgenus 3. Arachnocorythium, Haeckel. Definition. — Thorax with a variable number of radial ribs (twelve to twenty or more), prolonged into free terminal feet. 8. Arachnocorys polyjJtera, n. sp. Cephalis large, subspherical, with iiTegular, roundish pores and numerous radial spines. Thorax flatly conical, with numerous radial ribs (twenty to thirty), which are in the distal half free, in the proximal half connected by delicate arachnoidal wicker-work, with ]Dolygonal, irregular meshes. From its dorsal face arise numerous radial spines, whic'h are connected together, and with the cephalic spines, by very thin and numerous threads, parallel between every two spines. Similar to 1268 THE VOYAGE OF H.M.S. CHALLENGER. Arachnocorys araneosa (Tl. 56, fig. 11), but differing in the structure of the eephalis, and in the greater number of the ribs and spines. Dimensions. — Cephalis 0-04 diameter, thorax 012 long, 0-24 broad. Habitat. — South Pacific, Station 300, depth 1375 fathoms. Genus 5G5. Anthocyrtoma,^ n. gen. Definition. — S e t h o p h o r m i d a (vel Dicyrtida multiradiata aperta) without thoracic ribs, with six terminal feet around the mouth. Cephalis free, with an apical horn. The genus Anthocyrtoma and the four following genera form together the peculiar group of Carpocanida, comprising all those Sethophormida in which the original thoracic ribs are lost, and only the terminal feet remain. Anthocyrtoma is the simplest form of this group, possessing only six terminal feet, three primary perradial, and three alter- nating, secondary, interradial. It may be directly derived either from Lychnocanium, by interpolation of three interradial feet, or from Hexasj^yris by loss of the sagittal ring. I. Anthocyrtoma senmlata, Haeckel. Anthocyrtis serrulata, Ehrenberg, 1875, Abhandl d. k. Akad. d. Wiss. Berhn, p. 66, Taf. vi. fig. 7. Shell pear-shaped, rough, with obliterated collar stricture. Length of the two joints =1 : 4, breadth = 1 : 3. Cephalis ovate, with very small pores, and a stout conical horn of the same length. Abdomen inflated, truncate, with larger, regular, circular pores, twice as broad as the con- stricted mouth. Six feet vertical, parallel, serrate, all of the same size, about as long as the cephalis. Dimensions.- — Cephalis 0"06 long, O'Oo broad; thorax 0'2 long, 017 broad. Habitat — Fossil in Barbados. 2. Anthocyrtoma alterna, n. sp. Shell pear-shaped, smooth, with distinct collar stricture. Length of the two joints = 1:5, breadth=l:6. Cephalis hemispherical, with a slender conical horn of twice the length. Abdomen inflated, subglobular, with regular, circular, hexagonally framed pores, three times as broad as the narrow, constricted mouth. Six feet conical, smooth, somewhat divergent, alternating, of different sizes ; the three larger (perradial) half as long as the shell, and twice as long as the three smaller (interradial). (Similar to Antlwcyrtis ventricosa.) Dimensions. — Cephalis 0'03 long, 0-04 broad ; thorax 015 long, 018 Ijroad. ^ Hahitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. ' .4?ifAoci/rt077ia= Flower-arch ; sivh;, nii^ujiix. REPORT ON THE RADIOLARIA. 1269 Genus 566. Anthocyrtis,^ Ehrenberg, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, 1847, p. 54. Definition. — S e t h o p h o r m i d a (vel Dicyrtida multiradiata aperta) without thoracic ribs, with nine terminal feet around the mouth. Cephalis free, with an apical horn. The genus Anthocyrtis (in the original definition of Ehrenberg) contained all Dicyrtida without thoracic ribs, with terminal feet. We here restrict the definition to those Setho- phormida in which the number of free terminal feet is constantly nine (three primary perradial and three alternate pairs of secondary interradial feet). Anthocyrtis may be derived either directly from Patagospyris by loss of the sagittal ring, or from Lychno- canium by interpolation of three secondary feet. Subgenus 1. Anthocyrtella, Haeckel. Definition. — Feet of the peristome-corona divergent, their basal distance less than their terminal distance. 1. Anthocyrtis mespihis, Ehrenberg. Anthocyrtis mespilus, Elirenberg, 1854, Taf. xxxvi. fig. 13 ; Abhnudl. d. k. Akad. d. Wiss. Berlin, 1875, p. 66, Taf. vi. fig. 4 (not 5). Shell smooth, with distinct collar stricture. Length of the two joints = 1:5, breadth =: 2 : 6. Cephalis hemispherical, with a stout pyramidal horn of twice the length. Thorax nearly hemi- spherical, with regular, circular, quincuncial pores. Mouth scarcely constricted, with nine divergent, triangular, lamellar feet, about as long as the thorax. Dimensions.- — Cephalis 0'012 long, 0'02 broad ; thorax 0'05 long, 0-06 broad. Habitat.' — Fossil in Barbados. 2. Anthocyrtis furcata, Ehrenberg. Anthocyrtis furcata, Elirenberg, 1875, AbhandL d. k. Akad. d. Wiss. Berlin, p. 64, Taf. vi. fig. 2. Shell smooth, with deep collar stricture. Length of the two joints = l:5, breadth = 2 : 6. Cephalis hemispherical, with a short pyramidal horn of half the length. Thorax hemispherical, with large, irregular, roundish pores. Mouth scarcely constricted, with nine divergent, curved, slender feet, which are about as long as the shell, and forked at the distal end. JDimensions. — Cephalis 0-01 long, 0"02 broad ; thorax 0'05 long, 0-06 broad. Habitat. — Fossil in Barbados. 1 Anthocyrtis =Flov,'eT-h&sket ; duh;, kv^i;. 1270 THE VOYAGE OF H.M.S. CHALLENGER. 3. Anthocyrtis butomus, u. sp. Shell thorny, with obliterated collar stricture. Length of the two joints = 2 : 6, breadth = 2 : 7. CephaUs ovate, with very small and scarce pores, and a conical horn of the same length. Thorax inflated, pear-shaped, with regular, circular, quincuncial pores. Mouth about half as broad, con- stricted, with nine divergent, broad, nearly square, lamellar feet, half as long as the thorax (similar to Anthocyrtis scrrulata, Ehrenberg, loc. cit., Taf. vi. fig. 7). Divunsions. — Cephalis 0'05 long, 0'04 broad ; thorax 0"12 long, 014 broad. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 4. Anthocyrtis ventricosa, Ehrenberg. Anthocyrtis ventricosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. viii. fig. L Shell thorny, with obliterated collar stricture. Length of the two joints = l:7, breadth = 2 : 7. Cephalis hemispherical, hyaline, without pores, with a slender, conical horn, of about the same length. Thorax inflated, pear-shaped or subspherical, with regular, circular, quincuncial pores. Mouth only oue-tliird as broad, much constricted, with nine divergent, slender, conical feet, about one-fifth as long as the diameter of the sheU (partly broken off in Ehreuberg's figure). Dimensions. — Cephalis 0'03 long, 0'04 broad ; thorax 014 long, 014 broad. Habitat. — Tropical Atlantic, Station 338, depth 1990 fathoms ; also fossil in Barbados. Subgenus 2. Anthocyrtissa, Haeckel. Definition. — Feet of the peristome-corona parallel, vertical ; their basal and terminal distances equal. 5. Anthocyrtis ophirensis, Ehrenberg. Anthocyrtis ophirensis, Ehrenberg, 1872, Abhandl. d. k, Akad. d. Wiss. Berlin, p. 285, Taf. ix. fig. 13. Shell smooth, with slight collar stricture. Length of the two joints = 2:4, breadth = 1 : 5. Cephalis ovate, with irregular, roundish pores, and a pyramidal, excentric, vertical horn of the same length. Thorax campannlate, with delicate network of large, regular, hexagonal pores. Mouth scarcely constricted, with nine parallel, vertical, conical feet, about as long as the cephalis. (In the specimen figured by Ehrenberg only seven feet are represented, two being broken off; two other specimens of this species, captured by Eabbe, exhibited nine regularly disposed feet.) Dimensions. — Cephalis O'O." long, 0-02 broad ; thorax O'OS long, 01 broad. Habitat. — Indian Ocean, Zanzibar (Pullen) ; Madagascar (Eabbe), surface. REPORT ON THE RADIOLARIA. 1271 G. Anthocyrtis laiirantlius, u. sp. Shell smooth, with slight collar stricture. Length of the two joints=l: 3, breadth = l:4. Cephalis ovate, with large, roundish pores, and a conical horn of twice the length. Thorax inflated, cauipanulate, with regular, circular, hexagonally framed pores. Mouth two-thirds as broad, little constricted, with nine parallel, vertical, broad, lamellar, triangular feet, half as long as the cephalis. Di-mensmis. — Cephalis 0-04 long, 0-03 broad ; thorax 01 long, 0-12 broad. EaUtat. — Central Pacific, Station 266 to 270, depth 2550 to 2925 fathoms. 7. Anthocyrtis grossularia, Ehrenberg. Anthocyrtis grossularia, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 64, Taf. vi. tig. 6. Shell spiny, with deep collar stricture. Length of the two joints =1:5, breadth = 1:4. Cephalis subspherical, thorny, with a conical horn of the same length. Thorax ovate, spiny, with numerous densely-crowded, subregular, circular pores. Mouth about half as broad, constricted, with nine parallel, vertical, slender, conical feet, about as long as the cephalis. dimensions. — Cephalis 0'04 long, 0-05 broad ; thorax 0'2 long, 018 broad. Habitat. — Fossil in Barbados. 8. Anthocyrtis subglobosa, n. sp. Shell spiny, with deep collar stricture. Length of the two joints = 1:7, breadth = 1:7. Cephalis subspherical, with a conical horn twice the length. Thorax nearly spherical, with small and very numerous, regular, circular pores. Mouth only one-third as broad, constricted, with nine parallel, vertical, square, lamellar feet, about twice as long as the cephalis. Dimensions. — Cephalis 0-03 long, 0-035 broad ; thorax 0-2 long, 0-2 broad. Habitat. — South Pacific, Station 297, depth 1775 fathoms. Subgenus 3. Anthocyrtura, Haeckel. Definition. — Feet of the peristome-corona convergent, their basal distance greater than their terminal distance. 9. Anthocyrtis enneaphylla, n. sp. Shell smooth, with sharp collar .stricture. Length of the two joints = l : 6, breadth = l : .5. Cephalis subsjiherical, with a conical horn twice the length, nearly hyaline, with very small and scarce pores. Thorax nearly spherical, with regular, circular, quincuncial pores. Mouth only 1272 THE VOYAGE OF H.M.S. CHALLENGEE. half as broad, with nme broad, triangular feet, twice as long as the cephalis, and curved inwards, convergent towards the main axis. Dimensions. — Cephalis 0'02 long, 0'025 broad ; thorax Oil long, 012 broad. Habitat. — South Atlantic, Station 332, depth 2200 fathom.s. 10. Anthocyrtis ovata, n. s]). (PL 62, fig. 13). Shell smooth, with slight coUar stricture. Length of the two joints = 1:5, breadth =: 1 : 3. Cephalis ovate, with numerous small pores, and an excentric conical horn of the same length. Thorax ovate, with regular, circular, quincuncial pores. Mouth nearly of the same breadth, scarcely constricted, with nine triangular, widely-separated feet, about as long as the cephalis, and convergent towards the main axis. Dimensions. — Cephalis G'035 long, 0"03 broad ; thorax 015 long, 01 broad. Hahitat. — Central Pacific, Station 272, depth 2600 fathoms. Genus 567. Antliocyrtumi,^ u. gen. Definition. — S etliophormida (vel Dicyrtida multiradiata aperta) without thoracic ribs, with numerous terminal feet around the moutli (twelve to fifteen or more). Cej^halis free, with an apical horn. The genus Anthocyrtium has been derived from the two preceding genera by further multiplication of the terminal feet, the number of which is at least twelve to fifteen, often twenty or more. It may be that some species have arisen directly from Pata- gospyris by loss of the sagittal ring. Subgenus 1. Anthocyrtarium, Haeckel. Definition. — Feet of the peristome-corona divergent, their basal distance less than their terminal distance. 1. Anthocyrtiunfi chrysanthemum, n. sp. (PI. 62, fig. 14). Shell smooth, with distinct collar stricture. Length of the two joints = 3:7, breadth = 4:9. Cephalis hemispherical, with small, circular pores, and a large, straight, cylindro-conical horn, about as long as the shell. Thorax campanulate, hemispherical, with six to eight transverse rows of squarish pores, increasing in size downwards. Mouth Utile constricted, with twelve to fifteen divergent, curved, slender feet, about as long as the thorax. Dimensions. — Cephahs 0-03 long, 0-04 broad ; thorax 0-07 long, 0-09 broad. Hahitat. — Central Pacific, Station 270 to 274, depth 2350 to 2925 fathoms. 1 /ljiiftoci/rJium = Flower-basket; av^oj, Kv^rtov. EEPORT ON THE RADIOLAJRIA. 1273 2. Anthocyrtium centaurea, Haeckel. Anthocyrtis mesinlus, var. major, Ehrenberg, 1875, Abliandl. d. k. Akad. d. Wiss. Berlin, p. GG, Taf. vi. fig. 5. Shell smooth, with sharp collar stricture. Length of the two joints = 2:6, breadth = 3:7. Cephalis hemispherical, with ii-regular, roundish pores, and a very large pyramidal horn, longer than the shell, with contorted edges. Thorax hemispherical, with six to eight transverse rows of regular, circular pores of equal size. Mouth little constricted, with fifteen to twenty divergent, curved, slender feet, about as long as the shell. Dimensions. — Cephalis 0'02 long, 0'03 broad ; thorax 0'06 long, O'OV broad. Habitat. — Fossil in Barbados. 3. Anthocyrtium anthemis, n. sp. Shell papillate, with obliterated collar stricture. Length of the two joints = 1:3, breadth = 1:3. Cephalis hemispherical, with very small and scarce pores, and a conical horn of the same length. Thorax conical, as long as broad, with conical papillae, and eight to ten transverse rows of roundish pores, gradually increasing in size downwards. Mouth scarcely constricted, with fifteen to twenty divergent, straight, conical feet, half as long as the thorax. DimensioTis. — Cephalis 003 long, 0-04 broad ; thorax 0-09 long, 0'09 broad. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 4. Anthocyrtium collare, Haeckel. Anthocyrtis collaris, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 64, Taf. vi. fig. 8. Shell rough, conical, with obliterated collar stricture. Length of the two joints = 3:5, breadth =4:7. Cephalis conical, with a pyramidal horn of the same length, and with two transverse rows of rather oblong, narrow pores. Thorax truncate, conical, in the lower part thorny, with six to eight transverse rows of regular, circular pores, increasing in size downwards. Dimensions. — Cephalis 0'03 long, 0^04 broad ; thorax O'Oo long, 0'07 broad. Habitat. — Fossil in Barbados. 5. Anthocyrtium adonis, n. sp. (PL 62 fig. 20). Shell rough, with sharp collar stricture. Length of the two joints = 3 : 10, breadth = 4 : 12. Cephalis subspherical, with very small circular pores, and a very long, straight cylindrical, horn, twice to three times as long as the shell. Thorax inflated, ovate, or subspherical, with small regular, circular, hexagonally-framed pores. Mouth strongly constricted, half as l)road as the thorax, with fifteen to (ZOOL. CHALL. EXP. — PAKT XL. — 1886.) Er 160 1274 THE VOYAGE OF H.M.S. CHALLENGEE. twenty divergent, broad, lamellar, rectangular feet, as long as the thorax, and so densely placed that their margins come in contact with one another. Dhnensions. — Cephalis 0'03 long, 0'04 broad ; thorax 01 long, 012 broad. Habitat. — ^Central Pacific, Station 263 to 268, depth 2650 to 3000 fathoms. 6. Anthocyrtium anemone, n. sp. Shell spiny, with sharp collar stricture. Length of the two joints = 1:5, breadth =1:4. Cephalis subspherical, with a conical horn of half the length, hyaline, without pores. Thorax spiny, pear-shaped, inflated, with small and numerous, regular, circular pores. Mouth constricted, half as broad as the thorax, with twelve to fifteen divergent, slender, conical, denticulate feet, half as long as the thorax. Dimensions. — Cephalis 0'03 long, 0'04 broad ; thorax 014 long, 012 broad. Habitat. — Tropical Atlantic, Station, 347, depth 2250 fathoms ; also fossil in Barbados. Subgenus 2. Anthocyrtonium, Haeckel. Definition. — Feet of the peristome-coroua parallel, vertical ; their basal and apical distances equal. 7. Anthocyrtium campanula, n. sp. (PI. 62, fig. 17). Shell smooth, with deep collar stricture. Length of the two joints = 1 : 3, breadth = 1 : 3. Cephalis spherical, with a conical horn of the same length. Thorax campanulate, thin-walled, with delicate network of regular, hexagonal pores and thin bars. Mouth little constricted, with twenty to twenty-four parallel, vertical, lanceolate feet, about as long as the cephalis. Dimensions. — Cephalis 0'03 diameter, thorax O^OO long, 01 broad. Habitat. — South Pacific, Station 302, depth 1450 fathoms. 8. Anthocyrtium reticulattim, Haeckel. Tliyrsocyrtis retieuluta, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xii. fig. 10. Shell rough, with sharp collar stricture. Length of the two joints =1:2, breadth = 1:3. Cephalis hemispherical, with a prismatic, denticulate horn of the same length, and small, irregular pores. Thorax campanulate, thorny, tliin-walled, with delicate network of irregular, polygonal pores. Mouth little constricted, with twelve (or more) small, parallel, vertical, triangular feet, shorter than the cephalis. Dimensions. — Cephalis 0-015 long, 0-02 broad ; thorax 0'04 long, 0'06 broad. Habitat. — Fossil in Barbados. REPORT ON THE RADIOLARIA. 1275 9. Anthocyrtium leptostylum, Haeckel. Anthocyrtis leptostyla, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 64, Taf. vi. fig. 1. Shell thorny, with slight collar stricture. Length of the two joints = 1 : 5, breadth = 2 : 4. Cephalis hemispherical, with small, scarce pores and a slender conical horn of the same length. Thorax spiny, with regular, circular, quincuucial pores. Mouth constricted, half as broad, with twelve to eighteen slender, parallel, vertical feet, about as long as the cephalis. Dime'iisions. — Cephalis 0-02 long, 0-04 broad ; thorax 01 long, 0'08 broad. Habitat. — Central Pacific, Stations 266 to 270, depth 2550 to 2925 fathoms ; also fossil iu Barbados. 10. Anthocyrtium hispidum, Haeckel. Anthocyrtis hispida, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 64, Taf. viii. fig. 2. Anthocyrtis hispida, Biitschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 540, Taf. xxxiii. fig. 30. Shell thorny, with sharp coUar stricture. Length of the two joints = 1:4, breadth = 2:5. Cephalis hemispherical, hyaline, with few very small pores, or without any ; with a stout conical horn of twice the length. Thorax spiny, with regular, circular, hexagonally-framed pores (half as broad as the bars between them). Mouth wide open, scarcely constricted, with twelve to fifteen parallel, vertical, broad, lamellar, rectangular feet, reaching nearly the length of the thorax. Dimensions. — Cephalis 0-02 to O'OS long, 0-03 to 0-05 broad ; thorax 0-07 to 0-09 long, O'l to 0-12 broad. Habitat. — Central Pacific, Stations 263 to 265, depth 2650 to 3000 fathoms ; also fossU in Barbados. 11. Anthocyrtium turris, n. sp. Shell thorny, very similar to Caloeydas turris, Ehrenberg (1875, loc. cit., Taf. x^iii. fig. 7), but without fenestrated abdomen. CoUar stricture deep. Length of the two joints = 1 : 3, breadth = 1 : 3. Cephalis subspherical, hyaline, without pores, with a stout conical horn of twice the length. Thorax nearly spherical, spiny, with regular, circular, quincuncial pores. Mouth little constricted, with fifteen to twenty parallel, vertical, broad, lamellar, rectangular feet, about as long as the thorax. Dimensions. — Cephalis O^OS long, 0'03 broad ; thorax 01 long, 01 broad. HaJbitat. — Central Pacific, Station 265, depth 2900 fathoms. 1276 THE VOYAGE OF H.M.S. CHALLENGER. 12. Anthocyrtium doronicum, n. sj). (PL 62, fig. 18). Shell rough, with sharp collar stricture. Length of the two joints = 1 : 5, breadth = 1 : 3. Cephalis hemispherical, with small, circular pores and a stout conical horn of twice the length. Thorax campanulate, subcylindrical, with regular, circular, quincuncial pores, three to four times as broad as the bars. Mouth scarcely constricted, with twenty-four to thirty vertical, nearly parallel, little curved feet, which are about half as long as the shell, broad, lamellar, rectangular, and in close contact with their edges. Dimensions — Cephahs 0'025 long, 0"035 broad ; thorax 0'12 long, Ol broad. Sabiiat. — South Pacific, Station 295, depth 1500 fathoms. Subgenus 3. Anthocyrturium, Haeckel. Definition. — Feet of the peristome-corona convergent, their basal distance greater than their apical distance. 13. Anthocyrtium jpyrum, n. sp. (PI. 62, fig. 12). Shell smooth, with obliterated collar stricture. Length of the two joints = 2 : 7, breadth = 3 : 8. Cephalis hemispherical, with a small, bristle-shaped horn of half the length. Thorax inflated, subglobose, with regular, circular, quincuncial pores and thin bars. Mouth constricted, only half as broad, with fifteen to twenty small, triangular, convergent feet, shorter than the cephalis. (In another specimen the feet were twice as long, stronger and more convergent, than in the one figured.) Dimensions. — Cephalis 0"02 long, 0'03 broad ; thorax 007 long, 0'8 broad. Habitat. — North Pacific, Station 241, depth 2300 fathoms. 1 4. Anthocyrtium setosum, Haeckel. Anthocyrtis setosa, Haeckel, 1862, Monogr. d. Kadiol., p. 311. 1 Lithopera setosa, Ehrenberg, 1854, Mikrogeol., Taf. xxxv. B., B. iv. fig. 23. Shell spiny, with sharp collar stricture. Length of the two joints = 1:2, breadth = 1:3. Cephalis hemispherical, with a conical horn of the same length and some accessory spines. Thorax campanulate, with subregular, circular pores. Mouth little constricted, with twenty to thirty small, triangular, convergent feet, about as long as the cephalis. (In Ehrenberg's incomjilete figure they are mostly broken off.) Dimensions. — Cephalis 0-02 long, 0'02 broad ; thorax 0'04 long, 0'06 broad. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. REPORT ON THE RADIOLARIA. 1277 15. Anthocyrtium ehreiibergii, Haeckel. Ardhocyrtis ehrenhergii, Stbhr, 1880, Palaeontogr., vol. xxvi. \>. 100, Taf. iii. fig. 21, a, h. Shell smooth, with obliterated collar stricture. Length of the two joints = 3 : 10. breadth = 2 : 8. Cephalis subcylindrical, with an excentric, stout, pyramidal horn of the same length. Thorax bottle-shaped, with small, regular, circular pores of equal size, ilouth little constricted, with twenty to thirty small, triangular, convergent feet, about half as long as the cephalis. Dimensions. — Cephalis 0"03 long, 0"02 broad ; thorax 0"1 long, 0'08 broad. Habitat. — Fossil in Tertiary i-ocks of Sicily (Grotte), Stohr. 16. Aiithocyrtium zangueharicum, Jla,eckel. Anthocijrtis zangueharica, Ehrenberg, 1872, Abhandl. d. k. Akad. d. "Wiss. Berlin, p. 285, Taf. ix. fig. 12. Shell smooth, with slight collar stricture. Length of the two joints =3 : 10, breadth = 2 : 7. Cephalis subspherical, with an excentric conical horn of the same length. Thorax slender, ovate or bottle-shaped, with irregular, roundish pores increasing in size downwards. Mouth little con- stricted, with twelve to fifteen small, triangular, convergent feet, about half as long as the cephalis. Dimensions. — Cephalis 0'03 long, 0'02 broad ; thorax O'l long, 0'07 broad. Habitat. — Indian Ocean (Zanzibar), depth 2200 fathoms, Pullen. 17. Anthocyrtium Jicus, Haeckel. Anthocyrtis ficus, Ehrenberg, 1875, Abhandl. J. k. Akad. d. Wiss. Berlin, p. 64, Taf. vi. fig. 3. Shell rough, with obliterated collar stricture. Length of the two joints = 2 : 12, breadth =3 : 10. Cephalis conical, with a large, cylindrical horn, pyramidal at the base, about as long as the thorax. Thorax subovate, truncate, papillate, with small, regular, circular, quincuncial pores of the same breadth as the bars. Mouth constricted, two-thirds as broad as the thorax, with fifteen to twentv strongly convergent, lamellar, rectangular or sword-shaped feet, nearly as long as the thorax. DinunsioTis. — Cephalis 0"02 long, 0'03 broad ; thorax 0'12 long, 01 broad. Habitat. — FossU in Barl^ados. 18. Anthocyrtium Jlosculus, n. sp. (PL 62, fig. 19). Anthocyrtis flosculus, Haeckel, 1881, Prodromus et Atlas, pi. Ixii fig. 19. Shell ribbed, with distinct collar stricture. Length of the two joints = 1:4, breadth = 2:4. Cephalis hemispherical, with small, circular pores and a large cylindrical horn, twice as long as the thorax and half as broad at the base as the cephalis. Thorax subovate, truncate, with twenty- four to thirty longitudinal ribs and alternating rows of circular pores. Mouth constricted, two-thirds 1278 THE VOYAGE OF H.M.S. CHALLENGER. as broad as the thorax, with twenty-four to thirty slender, convergent feet, which are as long as the entire shell, with their edges in close contact and their distal ends pointed. Dimensions. — Cephalis 0-03 long, 0-05 broad ; thorax 0-12 long, 0-12 broad. Habitat. —Central Pacific, Stations 265 to 274, depth 2350 to 2925 fathoms. Genus 568. Anthocyrtidium,^ Haeckel, 1881, Prodromus, p. 431. Definition. — S e t h o p h o r m i d a, (vel Dicyrtida multiradiata aperta) without thoracic ribs, with numerous (twelve to fifteen or more) subterminal feet, which are separated from the constricted mouth by a ring of lattice-work. Cephalis free, with an apical horn. The genus Anthocyrtidiuvi has been derived from the preceding Anthocyrtium l;>y further growth and constriction of the peristome, which becomes separated from the subterminal corona of feet by a more or less broad ring of lattice-work. 1. Anthocyrtidium cineraria, n. sp. (PI. 62, fig. 16). Shell campanulate, smooth, with obliterated collar stricture. Length of the two joints = 5 : 11, breadth = 3 : 13. Cephalis subcylindrical-ovate, with a conical straight horn of half the length. Thorax hemispherical, inflated, nearly twice as broad as the constricted mouth. Pores subregular, circular, double-contoured. Above the mouth, separated from it by two rows of pores, a corona of twelve to fifteen short conical feet, which are directed downwards, slightly curved, and as long as the cephalic horn. Dimensions. — Cephalis 0'05 long, 0'03 broad; thorax Oil long, 0'13 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 2. Anthocyrtidium ligularia, n. sp. (PL 62, fig. 15). Shell campanulate, rough, with distinct collar stricture. Length of the two joints = 1:4, breadth = 2:6. Cephalis hemispherical, with a slender, conical, slightly curved horn, about as long as the shell. Thorax hemispherical, three times as broad as the cephalis, nearly twice as broad as the constricted mouth, which is prolonged into a prominent smooth ring. Above the mouth, separated from it by one row of pores, a corona of twelve to fifteen slender linear feet, .which axe shghtly curved, divergent, and emarginate at the truncated distal end. Dimensions. — Cephalis 0015 long, 0'03 broad ; thorax 0-06 long, 0'09 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. ' Anthocyrtidium =SiiKin flower-basket ; xuh;, x^frjojoi/. REPORT ON THE RADIOLARIA. 1279 3. Anihocyrtidium matricaria, u. sp. Shell campanulate, rough, very similar to the preceding species, but differing in the straight, large, pyramidal horn of the cephalis (as long as the shell), and in the longer, feet, which are twelve to fifteen in number, little curved at the distal end, pointed, and about as long as the shell. Length of the two joints = 2:6, breadth = 3:8. Differs from the similar Antlwcyrtium ccntaurea, Ehrenberg (1875, loc. ciL, Taf. vi. fig. 5), mainly in the prominent ring of the peristome. Dimensions. — Cephahs, 0-02 long, 0-03 broad ; thorax 0-06 long, 0-08 broad. Habitat. — Fossil in Barbados. Genus 569. Carpocanium,^ Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, jj. 54. Definition. — S e t h o p h n r m i d a (vel Dicyrtida mnltiradiata aperta) without thoracic ribs, with numerous terminal feet around the month (six to twelve or more). Cephalis hidden in the thorax, without apical horn. The genus Carpocanium, very common, and rich in numerous living and fossil species, w^as formerly placed by me among the true Monocyrtida, since an external constriction is not visible (Monogr., 1862, p. 290). Afterwards (in 1879) Eichard Hertwig demonstrated that the cavit}^ of the ovate shell, externally simple, is divided by an internal transverse septum into two joints, the upper of which is the flat rudimentary cephalis (Organism, d. Radiol., p. 79; compare also Butschli, 1882, Zoc. cit., p. 535). Indeed this septum, with four central crossed cortinar beams, is a true collar septum, and Carpocanium has been derived from Anthocyrtis or Desmospyris by reduction of the cephalis, which is very flat and perfectly hidden in the uppermost part of the thorax. The apical horn is lost. If the internal septum were to become lost, the genus would pass over into Caipocanistrum. Subgenus 1. Carp>ocanarium, Haeekel. Definition- — Peristome-corona composed of six feet (three primary perradial alter- nating with three secondary interradial). 1. Carpocanium caly codes, Stohr. Carpocanium calycodes, Stohr, 1880, Palaeontogr., vol. xxvi. p. 96, Taf. iii. tig. 8. Shell urceolate, smooth, nearly twice as long as broad, with hemispherical vaulted cephalis. Length of the two joints = 3 : 16, breadth =5 : 10. Pores regular, circular, as broad as the bars, ' Carpocanium = Fruit-basket ; xajTroV, xMntov. 1280 THE VOYAGE OF H.M.S. CHALLENGEE. quincuncially disposed in about five longitudinal series at each side. Mouth constricted, half as broad as the thorax. Peristome with six vertical, equilateral, triangular feet. Dimensions. — Cephalis 0-015 long, 0-025 broad; thorax 0-08 long, 0-05 broad. Habitat. — Fossil in Tertiary rocks of Sicily (Grotte, Caltanisetta). 2. Carpocanium setosum, Haeekel. Halicalyptra setosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 160, Taf. ii. fig. 12. Shell ovate, truncate at the mouth, thorny, exactly as long as broad. Length of the two joints = 1:8, breadth = 3:9. Cephalis hidden, with very small pores. Thorax inflated, with regular, circular pores, twice as broad as the bars, in about ten longitudinal series at each side. Mouth constricted, half as broad as the thorax. Peristome with six vertical, parallel, broad, lamellar, rectangular feet, separated by equal intervals, half as long as the shell. Dimensions.^Ce])hslis O'Ol long, 0-03 broad; thorax O'OS long, 0-09 broad. Habitat. — Fossil in Barbados. 3. Carpocanium laeve, Ehrenberg. Carpocanium laeve, Ehrenberg, 1872, Abliandl. d. k. Akad. d. Wiss. Berlin, p. 287. Shell subspherical, smooth, equal in length and breadth, with little vaulted, cap-shaped cephalis. Length of the two joints = l : 6, breadth = 4 : 7. Pores regular, circular, twice as broad as the bars, in nine longitudinal rows. Mouth constricted, only one-third as broad as the thorax. Peristome with six strong conical feet, which are slightly curved and con\'ergent. Bimensions. — Cephalis 0-01 long, 0-04 broad ; thorax 0-06 long, 0*07 broad. Habitat. — Mediterranean (Greece); Tropical Atlantic, Station 348, depth 2450 fathoms. 4. Carpocanium lanceolatum, n. sp. Shell subspherical, thorny, with perfectly hidden cephalis. Length of the two joints = 1:3, breadth =1:3. Pores regular, circular, hexagonally framed, half as broad as the bars, in about sixteen longitudinal rows at each side. Mouth constricted, half as broad as the thorax. Peristome with six large lanceolate, vertical, lamellar feet, half as long as the shell. Dimensions. — -Cephalis 0-03 long, 0-03 broad ; thorax 0-09 long, O'OQ broad. Habitat. — South Pacific, Station 300, depth 1375 fathoms. Subgenus 2. Carpocanidium, HaeckeL Definition. — Peristome-corona composed of iiiue feet (three primary perradial and six secondary interradial). REPORT ON THE RADIOL ARIA. 1281 5. Carpocanium diadema, Haeckol. Carpocanium diadema, Haeckel, 1862, Monogr. d. Radiol, p. 290, Taf. v. fig. 1. Carpocanium diadema, R. Hertwig, 1879, Organism, d. Radiol., p. 79, Taf. viii. figs. 7, 7a, 8, 8a, 86. Shell ovate, with little vaulted cephalis. Length of the two joints = 1:8, breadth = 3:6. Pores regular, circular, iu about twelve longitudinal rows, twice as broad as the bars. Mouth constricted, half as broad as the thorax. Peristome with nine vertical, equilateral, triangular feet. Dimensions. — Cephalis OIU long, 0-03 broad ; thorax O'OS long, 0'06 broad. Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific ; many stations, surface. 6. Carpocanium cylindricum, n. sp. Shell cylindrical, with hemispherical, flatly vaulted cephalis. Length of the two joints = 1:4, breadth = 3 : 3. Pores regular, circular, double-contoured, as broad as the bars, in about fifteen longitudinal series. ]\Iouth constricted, two-thirds as broad as the thorax. Peristome with nine vertical, slender, triangular, pointed feet. Dimensions. — Cephalis 0'02 long, 0'06 broad ; thorax O^OS long, 0'06 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 7. Carpocanium enneaphyllum, n. sp. Shell slenderly ovate, at the mouth truncate, thorny, with hemispherical, vaulted cephalis. Length of the two joints = 1:6, breadth = 2:4. Pores regular, circular, hexagonally framed, as broad as the bars, in about thirteen longitudinal rows. Mouth constricted, about two-thirds as broad as the thorax. Peristome with nine broad, lamellar, vertical, nearly square feet, half as long as the shell, with small intervals. Dimensions. — Cephalis 0'02 long, 0'04 broad ; thorax 012 long, 0'09 broad. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 8. Carpocanium solitarium, Ehrenberg. Carpocanium solitarium, Ehrenberg, 1854, Mikrogeol., Taf. xxii. fig. 28. Litliocampe solitaria, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 65. Shell slenderly ovate, twice as long as broad, with hidden spherical cephalis, completely enclosed in the simimit of the thorax. Length of the two joints = 1:6, breadth = 1:4. Pores small, regular, circular, as broad as the bars, in about eleven longitudinal rows. Mouth gradually constricted, half as broad as the thorax. Peristome with nine ovate blunt feet, which are as long as the cephalis, little curved and convergent. Dimensions. — Cephalis 0'02 long, 0'02 broad ; thorax 0"12 long, 0'07 broad. Habitat. — Fossil in Tertiary rocks of Sicily (Caltanisetta). (ZOOL. GHAIi. EXP. — PART XL. — 1886.) Rr 161 1282 THE VOYAGE OF H.M.S. CHALLENGER. 9. Carpocanium gemmula, n. sp. Shell subspherical, smooth, equal in lengtl: aud breadth, with hemispherical vaulted cephalis. Length of the two joints = 2:7, breadth = 4:9. Pores small, regular, circular, twice as broad as the bars, in about twenty longitudinal rows. Mouth strongly constricted, only one-fourth as broad as the thorax. Peristome with nine conical feet, which are twice as long as the cephaHs, curved, and so convergent that their distal ends come nearly in contact. Dimensions. — Cephalis 0-02 long, 0'04 broad ; thorax 0'07 long, 0'09 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 10. Cai'pocanium microdon, Ehrenberg. Carpocavium microdon, Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d. "Wiss. Berlin, p. 30. SheU broad, ovate, rough, with perfectly hidden cephalis. Length of the two joints = 2:9, breadth =4:7. Pores very small and scarce, smaller than the bars between them, irregularly scattered. Mouth constricted, one-third as broad as tlae thorax. Peristome with nine short, triangular, pointed, convergent feet. Dimensions. — Cephalis 0'02 long. 0-04 broad ; thorax 0'09 long, 0-07 broad. Habitat. — Mediterranean (Crete), Atlantic (Canary Islands), Station 354, surface. Subgenus 3. Carpocanobium, Haeckel. Definition. — Peristome-coroua composed of twelve or more feet. 11. Carpocanium trepanium, n. sp. (PI. 52, tig. 18). Shell subcylindrical, with flatly vaulted cephalis. Length of the two joints = 1:6, breadth = 3:4. Pores regular, hexagonal, four to six times as broad as the bars. Mouth Little constricted, two- thirds as broad as the thorax. Peristome with eighteen to twenty-four large, slender, triangular, vertical feet. Dimensions. — CephaHs 0'02 long, 0"06 broad ; thorax 0'12 long, G'08 broad. Habitat. — Indian Ocean, Madagascar (Eabbe), surface. 12. Carpocanium hexagonale, n. sj). (PL 52, fig. 15). Shell broadly ovate or subconical, with vaulted, cap-shaped cephalis. Length of the two joints = 2 : 7, breadth = 5 : 9. Thorax subglobular, truncate. Pores subregular, hexagonal, three to four times as broad as the bars. Mouth consti-icted, two-thirds as broad as the thorax. Peristome with twenty to twenty-five small, triangular, vertical feet. Dimensions. — Cephalis 0-02 long, 0-05 broad ; thorax 0-07 long, 0-09 broad. Habitat. — Tropical Atlantic, Station 347, surface. REPOET ON THE RADIOLARIA. 1283 13. Carpocanium petalospyris, u. sp. (PI. 52, fig. 19). Shell subspherical, smooth, with perfectly hidden cephalis. Length of the two joints = 1:6, breadth = 3:6. Pores regular, circular, hexagonally framed, twice as broad as the bars, in about sixteen longitudinal rows. Mouth slightly constricted, little narrower than the thorax. Peristome with twenty to twenty-four vertical, broad, lamellar feet, which are nearly as long as the shell, at the distal end truncate, and almost in contact at their edges. Dimensions. — Cephalis 0-02 long, 0-05 broad ; thorax 0"11 long, 0'12 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 14. Carpocanium polypterum, Haeckel. Crijptoprora polyptera, Ehrenberg, 1872, Abhandl. d. k. Akad. d. "Wiss. Berlin, p. 287, Taf. ix. fig. 17. Carpocanium macropterum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 302. Shell campanulate-conical, smooth, with perfectly liidden cephalis. Length of the two joints = 1 : 6, breadth = 4:6. Pores regular, circular, twice as broad as the bars, in about sixteen longi- tudinal rows. Mouth wide open, not constricted. Peristome with twenty to thirty vertical, slender, conical feet, about as long as the shell. Dimensions. — Cephalis O'Ol long, 0-04 broad ; thorax O'OG long, 0"06 broad. Habitat. — Indian Ocean (Zanzibar), depth 2200 fathoms (Pullen). 15. Carpocanium palmipes, n. sp. Shell ovate, very thick-walled, smooth. Lower half of the subspherical cephalis hidden in the summit of the thorax, upper half free, with few small pores. Length of the two joints = 3 : 10, breadth =3 : 10. Thorax foveolate, with oblong dimples, each of which enclo-ses a small, circular, double-contoured pore, half as broad as the bars. Mouth little constricted, nearly as broad as the thorax. Peristome prolonged into a solid, cylindrical tube, nearly as long and as broad as the shell ; the upper half of the tube is solid, the lower divided into from twelve to fifteen vertical, lamellar, pointed feet. Diiiwnsions. — Cephalis 0'03 long, 0-03 broad ; thorax O'l long, O'l broad. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 16. Carpocanium per istomium, n. sp. (PI. 52, figs. 16, 17). Shell ovate, smooth, with perfectly hidden, flat cephalis (fig. 17). Length of the two joints = 2 : 10, breadth = 5 : 9. Pores small and very numerous, regular, circular, as broad as the bars, in about twenty longitudinal rows. Mouth little constricted. Peristome broad ; in the upper 1284 THE VOYAGE OF H.M.S. CHALLENGEE. half a hyaline, circular ring, in the lower half divided into from eighteen to twenty-four triangixlar, curved, little convergent feet. Dimensions. — Cephalis 0'02 long, 0'05 broad ; thorax 01 long, 0'09 broad. Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific ; many stations, at various depths. 17. Carpocanitim coronatum, Ehrenberg. Carpocanium coronatum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. v. fig. 7. SheU ovate, smooth, with perfectly hidden, subspherical cephalis. Length of the two joints = 2 : 9, breadth = 2 : 8. Pores small and very numerous, twice as broad as the bars, regular, circular, in about twenty longitudinal rows. Mouth little constricted, two-thirds as broad as the thorax. Peristome with twenty-five to thirty short, bristle-shaped feet, which are slightly curved, convergent, and in the upper half connected by a soUd ring. Dimensions. — Cephalis 0'02 long, 0-02 broad; thorax 0'09 long, 0"08 broad. Habitat. — Fossil in Barbados. 18. Carpocanium dactijlus, n. sp. SheU slenderly ovate, twice as long as broad, with flat, perfectly hidden cephalis. Length of the two joints = 1 : 12, breadth = 4 : 8. Pores subregular, circular, as broad as the bars, ia about twelve longitudinal rows, separated by prominent longitudinal ribs. Mouth con- stricted, two-thirds as broad as the thorax. Peristome with twelve large, lanceolate, lamellar, convergent feet. Dimensions. — Cephalis O'Ol long, 0-04 broad ; thorax 0'12 long, 0-08 broad. Habitat. — South Pacific, Station 295, depth 1500 fathoms. 19. Carpocanium irregulare, n. sp. (PI. 52, fig. 14). Shell irregular, roundish, subovate, with flat and oblique, perfectly hidden cephahs. Length of the two joints = 1 : 10, breadth = 3 : 9. Pores irregularly .scattered, roundish, about as broad as the bars. Mouth wide open, not at all or little constricted. Peristome with twenty to thirty long, lamellar, pointed feet, which are irregularly curved and convergent. Dimensions. — CephaUs O'Ol to 002 long, 0-03 to 0-04 broad ; thorax 0-09 to Oil long, O'OS to 0-09 broad. Habitat. — Central Pacific, Station 2G3 to 274, surface, and at various depths. 20. Cariiocanium verecwidum, n. sp. (PI. 52, figs. 12, 13). Sliell ovate, smooth, with flat, perfectly hidden cephahs (fig. 12). Length of the two joints = 1 : 9, breadth = 4:9. Pores subregular, circular, twice as broad as the bars, in about eighteen, REPORT ON THE RADIOL ARIA. 1285 partly interrupted, longitudinal rows, separated by prominent crests. Month little constricted. Peristome with twenty to twenty-four broad, lamellar, pointed feet, which are about as long as the shell, little curved, and convergent. Dimensions. — Cephahs O'Ol long, 0-04 broad ; thorax 0'09 long, 0-09 broad. Halitat. — North Pacific, Station 244, depth 2900 fathoms. 21. Carpocanium virginexcm, n. sp. (PI. 52, fig. 20). Shell ovate, smooth, with flat, perfectly hidden cephaJis. Length of the two joints = 1:8, breadth = 3:9. Pores regular, circular, hexagonally framed, as broad as the bars, in about sixteen longi- tudinal rows on each side. Mouth little constricted. Peristome with eighteen to twenty-four very large, lamellar, pointed feet, which are longer than the shell, and so curved and convergent that their distal points come nearly in contact. Dimciisioiis. — Cephahs O'Ol long, 0'03 broad ; thorax 0'08 long, 0'09 broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. Subfamily 2. Sethoph^nida, Haeckel, 1881, Proclromus, p. 433. Definition. — A n t li o c y i" t i d a with the basal mouth of the shell fenestrated (vel Dicyrtida multiradiata elausa). Genus 570. Sethophcena,'^ Haeckel, 1881, Prodromus, p. 433. Definition. — S e t h o p h se n i d a {vel Dicyrtida multiradiata elausa) with lateral apophyses. Cephalis with a horu. The genus Sethophcena and the following Clistophcena form together the small sul)- family of Sethophsenida, comprising those Dicyrtida in which the thorax bears numerous radial appendages (four to six or more), and the mouth is closed by a lattice-plate. In SethophcBna the apophyses are lateral wings, as in Micromelissa, from which it may be derived by development of secondary wings, interpolated between the three primary wings. 1. Sethophcena tetraptera, n. sp. Shell smooth, with deep coUar stricture. Length of the two joints = 3:10, breadth = 4 : 9. Cephalis subspherical, without horn. Thorax ovate, with rounded hemispherical base, and subregular, hexagonal pores. From its upper half (below the collar stricture) arise four divergent, 1 Se(/i«p/i(E?ia = Sieve-shell ; aviSu, (fxlua. 1286 THE VOYAGE OF H.M.S. CHALLENGER. conical, straight wings, of half the length, opposite in pairs in two meridional planes, perpendicular to one another (compare Tetralacorys, PL 65, figs. 4, 5). Dimensions. — Cephalis 0-03 long, 0'04 hroad ; thorax 01 long, 0-09 broad. Hahitat. — South Pacific, Station 300, depth 1375 fathoms. 2. Sethoi^hcena hexaptera, n. sp. (PI. 97, fig. 13). Shell rough, pear-shaped, with distinct collar stricture. Length of the two joints = 1:4, breadth = 2:4. Cephalis hemispherical, with a conical horn of the same length. Thorax inflate, inversely ovate, nearly pear-shaped, with subregular, circular pores. From its upper half arise, by a broad base, six divergent, strong, conical wings, which are horu-Uke, curved downwards, and half as long as the thorax. Dimensions. — Cephalis 0'025 long, 004 broad ; thorax 0"09 long, 0"08 broad. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 3. Sethophcena emieaptera, n. sp. Shell rough, with sharp collar stricture. Length of the two joints = 1:6, breadth = 1:3. CephaUs subspherical, with a stout conical horn of twice the length. Thorax inversely ovate, with pointed, conical, basal part, and irregular, roundish pores. From its middle part arise, by a broad triangular base, nine compressed, divergent wings, which are a Little curved, slender, and about as long as the thorax. Dimensions. — Cephalis 0'025 long, 0'03 broad ; thorax 017 long, 01 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 4. Sethophcena polyptera, n. sp. Shell thorny, with slight collar stricture.* Length of the two joints = 1 : 10, breadth = 3 : 8. Cephalis flat, cap-shaped, without horn. Thorax pear-shaped, with hemispherical base and regular, circular pores. From its lower half (beyond the equator) arises a corona of numerous short conical wings (eighteen to twenty-four), which are a little curved, and divergent downwards, scarcely one-third as long as the thorax. Dimensions. — Cephalis O'OIS long, O'Ol broad ; thorax 015 long, 012 broad. Habitat. — North Pacific, Station 253, depth 3125 fathoms. Genus 571. Clistophcena, Haeckel, 1881, Prodromus, j?. 433. Definition. — S e t h o p h £e n i d a (vel Dicyrtida multiradiata clausa) with terminal apophyses. Cephalis with a horn. 1 Clistoph(ima — C\o&6& shell ; with truncate, constricted < or tubular mouth. Cephalis with two horns or a bunch of horns, _ Cephalis without horn. II. Subfamily Sethocapsida. Terminal mouth closed by a lattice-plate. Cephalis free, not hidden Iq | ' ' tVio tlinrn v j ^ ( Xo horn. the thorax. Cephalis hidden in the f ,, , , c ,, ., < ^0 horn, [ upper part of the thorax. •572. Sethoconus. 573. PeriararJinium. 574. Sethoceplialus. 575. Setlwcyrtis. 576. Setliocorijs. 577. Lojjlwpluena. 578. Dicfi/oceplialus. 579. Setlwcapsa. 580. Dicolocapsa. 581. Cryptocapsa. Subfamily 1. Sethocorida, Haeckel, Prodromus, p. 430. Definition. — S e t h o c y r t i d a with the basal mouth of the shell open (vel Dieyrtida eradiata aperta). (ZOOL. CHALL. EXP. — PART XL. — 1886.) Er 162 1290 THE VOYAGE OF H.M.S. CHALLENGER. Genus 572. Sethoconns,^ Haeckel, 1881, Prodromus, p. 430. Definition. — S e t h o c o r i d a (vel Dicyrtida eradiata aperta) with conical or campanulate, gradually dilated thorax and wide open mouth. Cephalis with one or more horns. The genus Sethoconus is the oldest and simplest form of the Sethocorida, or of those Dicyrtida in which the simple thorax bears no apophyses and has the mouth open and not closed by a basal lattice-plate. Probaljly all those eradiate Sethocorida have been derived either from triradiate Sethopilida {Lychnocanium) , or from multiradiate Sethophormida {Sethophormis, Anthocyrtis 1) by loss of the radial ribs and feet. In Sethoconus the thorax is more or less conical, sometimes more campanulate, commonly smooth, in some species covered with spines. The cephalis is usually small, with rudimentary collar septum, at other times large, with distinct cortinar septum. Correspondingly, the genus may be divided into different groups, which here are enumerated as subgenera. Subgenus 1. Conarachnium, Haeckel, 1881, Prodromus, p. 430 ( = Ceratocyrtis, Biitschli), 1882, loc. cit., p. 536. Definition, — Cephalis relatively large, with distinct collar septum and numerous pores. Thorax smooth. 1. Sethoconus trochus, Haeckel. Eucyrtidium trochus, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 293, Taf. vii. fig. 17. Conarachniura troclms, Haecksl, 1881, Prodromus, p. 4.30. Cephalis ovate, relatively large, with a pyramidal horn of the same length, and three pairs of large opposite pores, on each side of a vertical septum. Thorax wide, conical, about as long as broad, with nearly straight outlines ; its pores regular, circular, hexagonaUy framed, of the same size as the cephalic pores. Dimensions. — Cephalis O'Oo long, 0"02 broad; thorax 0'06 long, 0'06 broad. Habitat. — Tropical Pacific, Stations 200 to 281, surface. 2. Sethoconus cucullaris, Haeckel. Coniutella nicullaris, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. ii. fig. 7. Ceratocyriis ciwuUaris, Biitschli, 1882, Zeitschr. f. wiss. ZooL, Bd. xsxvi. p. 536, Taf. xxxiii. fig. 36, a. h. Cephalis subspherieal, thorny, relatively large, with a conical horn of the same length, and small circular pores. Thorax wide, conical, enveloping the lower hidden half of the cephalis, about as ' Sethoconus = Sieve-cone ; ai^a, kui/o:. REPORT ON THE RADIOLARIA. 1291 long as broad, with sliglitlj' convex outlines ; its pores subregular, circular, half as broad as the cephalis. Dimensions. — Cephalis 0"03 long, 0'02 broad ; thorax 015 long, 014 broad. Habitat. — Fossil in Barbados. 3. Setlioconus jnleus, n. sp. Cephalis subspherical, free, with distinct collar stricture, a conical oblique horn of the same length, and small, irregular, roundish pores. Thorax flatly conical, about half as long as broad, with straight outlines ; its pores subregular, hexagonal, half as broad as the cephalis, with very thin bars. Dimensions. — Cephalis 0'02 long, 0'02 broad ; thorax 0'08 long, 016 broad. Habitat. — Central Pacific, Stations 262 to 274, surface. 4. Sethoconus ampliatus, Haeckel. Cornutella ampliata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. ii. fig. 5. Ceratocyrtis ampliata, Biitschli, 1882, Zeitsclir. f. wiss. Zool., Bd. xxxvi. p. 5.3G. Cephalis, hemispherical, thorny, with a conical horn of twice the length; it is separated from the thorax by a complete internal collar septum, but without external collar stricture. Thorax flatly conical, about half as long as broad, with straight outlines ; its pores subregular, hexagonal, about as large as the cephalis, with thin bars. Dimensions. — Cephalis 0'015 long, 0'03 broad ; thorax 0'08 long, 018 broad. Habitat. — Fossil in Barbados. 5. Sethocomis mitra, Haeckel. Cornutella mitra, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. ii. fig. 8. Ceratocyrtis mitra, Btitschli, 1882, Zeitschr. f. wiss. Zool., Bd. xxxvi. p. 536. Cephalis ovate, with slight collar stricture (not distmct enough in Ehrenberg's figure), with few large pores, and a conical stout horn of the same length. Thorax campanulate, conical, twice as long as broad, with slightly convex outlines ; its pores subregular, roundish, increasing in size towards the mouth, the largest as broad as the cephalis. Dimensions. — Cephalis, 0'03 long, 0'02 broad ; thorax 012 long, 0"07 broad. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms ; fossU in Barbados. 6. Sethoconus rayianus, n. sp. (PL 58, fig. 6) Conarachnium rayianum, Haeckel, 1881, Prodromus, p. 430. Cephalis ovate, with obliterated collar stricture (but distinct internal septum), with small, irregular pores, and two to four divergent horns, which are longer than the cephalis, and two or three of which are forked. Thorax tent-shaped, conical, two-thirds as long as broad, with slightly 1292 THE VOYAGE OF H.M.S. CHALLENGER. concave outlines, and subregular, hexagonal pores, gradually increasing towards the mouth, the largest half as broad as the cephalis. This elegant species is dedicated to Dr. Eay, the discoverer of many rare Eadiolarians in the Challenger collection. Dimensions. — Cephalis 0'03 long, 0'02 broad ; thorax 0'08 long, 012 broad. Habitat. — Central Pacific, Stations 26G to 272, surface. 7. Sethoconus cervus, Haeckel. 1 Eucyrtidium cervus, Ehrenberg, 1872, Abhandl. d. k. Akad. d. "Wiss. Berlin, p. 291, Taf. ix. fig. 21. Cunaracliniimi cervus, Haeckel, 1881, Prodromus, p. 430. Cephalis subspherical, with slight collar stricture, small circular pores, and two to four di\-ergent horns, one or two of which are forked. Thorax wide, conical, about as long as broad, with straight outlines and irregular, polygonal pores, gradually increasing towards the mouth ; the largest as broad as the cephalis. Dimensions. — Cephalis O'Olo long, 0'02 broad ; thorax 0'08 long, O'OS broad. Habitat. — Indian Ocean ; Maldive Islands, surface (Haeckel) ; Zanzibar, depth 2200 fathoms (Pullen). 8. Sethoconus loj^hoj^hcena, u. sp. Conarachnium loplioplicvna, Haeckel, 1881, Prodromus, p. 430. Cephalis subspherical, with distinct collar stricture, small circular pores, and numerous (twelve to sixteen) radial, bristle-shaped horns of diflerent lengths. Thorax wide, conical, somewhat longer than broad, with slightly convex outlines, and subregular, hexagonal pores, increasing gradually in size towards the mouth ; the largest twice as broad as the cephalis. Dimensions. — Cephalis 0'03 long, 0-04 broad ; thorax 0'2 long, 0-16 broad. Habitat. — South Pacific, Station 300, depth 1375 fathoms. 9. Sethoconus larvatus, Haeckel. Loplwphana larvata, Ehrenberg, 1875, Abliandl. d. k. Akad. d. "Wiss. Berlin, p. 78, Taf. viii. fig. 10. Didyocsphalus larvatus, BUtschli, 1882, Zeitsclir. f. wiss. Zool., Bd. xxxvi. p. 535. Cephalis subspherical, large, with sliarp collar stricture, and numerous (five to ten or more) radial, conical (partly forked) horns of different lengths. Thorax wide, conical, somewhat broader than long, with straight outlines. Pores of both joints very irregular, roundish, of very different sizes and form. Dimensions. — Cephalis 0-04 long, O'Oo broad ; thorax O'i long, 012 broad. Habitat. — Fossil in Barbados. REPORT ON THE RADIOLARIA. 1293 10. SetJioconus Jiassa, Haeckel. Eucyrtidium nassa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. "Wiss. Berlin, p. 72, Taf. ix. fig. 9. Cephalis slenderly ovate, with sharp collar stricture, few scattered pores, and a very stout, pyra- midal horn of the same length, which is surrounded at the base by three short, divergent, ascending spines (perhaps the remnants of the three cortinar rods of Eucccry]3halas, &c.?). Thorax slender, conical, with straight outlines, and small, dense, regular, circular pores of equal size. JDimensions. — Cephalis 0'04 long, 002 broad ; thorax 012 long, 0"08 broad. Habitat. — Fossil in Barbados. 11. Sethocoiius tahulatus, Ilaeckel. Cydadopltova tahulata, Ehrenberg, 1872, AbhanJl. d. k. Akad. d. "Wiss. Berlin, p. 289, Taf. iv. Cg. 18. Cephalis subspherical, with slight collar stricture, and numerous small, irregular pores, without horn, or with a small conical horn. Thorax slenderly conical, with straight outlines, and large, regular, hexagonal pores. Mouth truncate. (In the specimen 1 examined the thorax was longer and more conically dilated ; the cephalis had a distinct small horn.) Dimensions. — Cephalis 0'02 long, 0'03 broad ; thorax 0"08 long, G-06 broad. Habitat. — North Atlantic, Antilles, depth IGOO fathoms (Ehrenberg); Station 347, depth 2250 fathoms. Subgenus 2. CornutelUum (vel Ceratarachnium), Haeckel, 1881, Prodromus, p. 4.30. Definition. — Cephalis very small, rudimentary, hyaline, vi^ithout distinct collar septum, and without jjores (or with scarce, rudimentary pores). Thorax smooth. 12. Sethoconus hexagonalis, Haeckel. Comutella trochns, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Derliu, p. 287, Taf. ix. fig. 14. Cephalis very small, subspherical, hyaline, without pores, with a rudimentary horn of half the length. Thorax slenderly conical, or bottle-shaped, twice to three times as long as liroad ; in the lower half nearly cylindrical, with very thin, thread-like bars, and regular, hexagonal pores, increasing in size towards the mouth. Biviunsions. — Cephalis 0'005 diameter, thorax 012 long, 0'05 broad. Habitat. — Indian Ocean, Zanzibar, depth 2200 fathoms (PuUen). 13. Sethoconus verrucosus, Haeckel Comutella verrucosa, Ehrenberg, If fig. 16. Cephalis very small, subspherical, hyaline, without pores, with a rudnuentary liorn of half the Comutella verrucosa, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. is. fis. 16. 1294 THE VOYAGE OF H.M.S. CHALLENGER. length. Thorax slenderly conical, or bottle-shaped, with little convex outlines ; three to four times as long as broad, papillate, with regular, circular pores, which are included by rhombic frames, and increase in size towards the mouth. Dimensions. — Cephahs 0'004 diameter, thorax 012 long, 0'035 broad. Habitat. — Indian Ocean (Zanzibar), depth 2200 fathoms (Pullen). 14. Sethoconiis orthoceras, n. sp. (PI. 54, fig. 11). Gornutella orthoceras, Haeckel, 1879, Atlas, loe. cit. Cephahs very small, conical, hyaline, without pores, with a double internal stricture, and a very short, rudimentary horn. Thorax slenderly conical, with undulate outlines, three to four times as long as broad, with subregular, roundish pores, gradually increasing in size towards the mouth. Dimeiisions. — Cephalis 0'02 long, O'Ol broad; thorax 0'16 long, 0'04 to 0'08 broad. Habitat. — South Atlantic, Station 325, surface. 15. Sethoconus jJfofimdus, Haeckel. CornuteUa profunda, Ekrenberg, 1854, Mikrogeol., Taf. xxxv. B, Nr. B. iv. fig. 21. Cornutella proftcnda, Bailey, 1856, Arncr. Jour., vol. xxii. pi. i. fig. 23. CornuteUa profunda, Haeckel, 1862, Monogr. d. EadioL, p. 284. Cephahs very small, spherical, hyaline, without pores and internal stricture, with a very short, rudimentary horn. Thorax slenderly conical, with straight outlines, three to four times as long as broad, with subregular, circular pores, gradually increasing in size towards the mouth. Dimensions. — Cephahs 0-004 to 0-008 diameter, thorax 0-08 to 0-12 long, 0-03 to 0-04 broad. Habitat. — CosmopoUtan ; Mediterranean, Atlantic, Indian, Pacific ; at various depths. 16. Sethoconus trichostylus, Haeckel. Cornutella trichosfyla, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. vi. fig. 2. Cephalis very small, conical, hyaline, without pores, with a very long, bristle-shaped, spirally twisted horn, longer than the whole shell. Thorax slenderly conical, with straight outHnes, and very small, regular, circular pores of nearly equal size, which are separated by broader bars and spirally ascending oblique crests (according to the figure). Dimensions. — Cephahs 0-004 long, 0-002 broad ; thorax O'OG long, 0-04 broad. Habitat. — North Pacific (California), depth 2600 fathoms. 17. Sethoconus lonqisetus, Haeckel. Cornutella longiseta, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. ix. fig. 15. Cephalis very small, spherical, hyaline, without pores, with a very long, bristle-shaped horn. REPORT ON THE RADIOLARIA. 1295 nearly as long as the shell. Thorax slenderly conical, rough, with straight outlines, and irregular, roundish pores, gradually increasing in size towards the mouth. Dimensions. — Cephalis Q-Ol diameter, thorax 0-09 long, 0-03 broad. Habitat. — Indian Ocean (Zanzibar), depth 2200 fathoms (PuUen). 18. Sethocomis gracilis, Haeckel. Eucyrtidium gracile, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xi. fig. 15. Cephalis small, subspherical, with few scarce pores, and a stout, pyramidal horn, of the same length. Thorax slenderly conical, three to four times as long as broad, with straight outlines, and very small and numerous circular pores of equal size. Dimensions. — Cephalis 0'015 diameter, thorax 012 long, 0'04 broad. Hahitat. — Fossil in Barbados. 19. Sethoconus himarginatus, n. sp. (PI. 54, fig. 12). Comutella bimarginata, Haeckel, 1879, Atlas, loc. cit. Cephalis very small, subspherical, hyaline, without pores, with a rudimentary, conical horn of the same length. Thorax slenderly conical, three times as long as broad, with undulated, little convex outlines, and irregular, roundish, double-contoured pores, arranged in nine longitudinal series, markedly increasing in size towards the mouth. Dimensions. — Cephalis 00 1 diameter, thorax OlO long, 0-05 broad. Habitat. — South Pacific, Station 300, depth 1375 fathoms. 20. Sethoconus clathratus, Haeckel. Coi-nutella elathrata, Ehrenberg, 1854, Mikrogeol., Taf. xxii. fig. 39«, h, c. Cephalis very small, subspherical, hyaline, without pores, with a rudimentary horn of half the length. Thorax slenderly conical, three to four times as long as broad, smooth, with curved axis and small, regular, circular pores, nearly equal in size. This common species differs from all others of the genus by the curvation of the axis of the shell, which is more or less crescentic, or curved like a cowherd's horn ; it may, therefore, represent a peculiar genus, Sethodrejpanum. Dimensions. — Cephalis 0-003 to 0-006 diameter, thorax 0-08 to 0-16 long, 0-03 to 0-05 broad. Hahitat. — Cosmopolitan ; Atlantic, Pacific, many stations ; fossil in Barbados and Sicily. Subgenus 3. Phlebarachnium, Haeckel (et Cladarachnium, Haeckel), 1881, Prodromus, p. 430. Definition. — Cephalis small, with very small pores, and internal collar septum. Thorax spiny or thorny. 1296 THE VOYAGE OF H.M.S. CHALLENGER. 21. Sethoconiis facetus, n. sp. (PL 55, fig. 1). PJilebarachnium facefum, Haecke], 1881, ProJromus, p. 430. Cephalis small, hemispherical, with distinct collar septum, the same network as the thorax, and numerous bristle-shaped horns of the same length. Thorax wide, conical, about as long as broad, with slightly convex outlines ; its network extremely delicate, with very small and numerous, regular, hexagonal pores, disposed in numerous divergent, longitudinal series, which are convoluted somewhat spirally around the shell axis. Surface covered with thin, scattered, bristle-shaped spines, about as long as the cephalis. Dimoisions. — Cephalis 0'02 diameter, thorax 0'2 long, 0-22 broad. Habitat. — Central Pacific, Stations 271 to 274, surface. 22. Sethoconus anthocyrtis, n. sp. (PI. 62, fig. 21). Antliocijrtis sethoconus, Haeckel, 1879, Atlas, loe. cit. Cephalis small, subspherical, with very small pores and numerous radial, bristle-shaped spines of the same length. Thorax wide, conical, about as long as broad, with parabolic outhnes, its net- work very delicate, with subregular, hexagonal meshes. Surface with scarce, bristle-shaped spiaes (not represented in the figure). Mouth with a corona of numerous small, vertical spines. Dimensions. — Cephalis 0'025 diameter, thorax 0'26 long, 0"24 broad. Habitat. — North Pacific, Station 248, surface. 23. Sethocorms virgultus, u. sp. CladaracJiniiun virgultum, Haeckel, 1881, Prodroiuus, p. 430. Cephalis and thorax nearly of the same form and stricture as in Sethoconus facdus, but larger and wider, with the same delicate, hexagonal network (PI. 55, fig. 1) ; it differs from the latter by the wider, more convex and campanulate form, but mainly by the armature of the surface, which is densely covered with thin, arborescent, bristle-shaped spines, irregularly branched, and four to eight times as large as the cephalis. Dimensions. — Cephalis 0'02 diameter, thorax 0'32 long, 0'4 broad. Habitat. — South Pacific, Station 288, surface. 24. Sethoconus setostis, n. sp. Phlebarachniam seiosum, Haeckel, 1881, Prodromus, p. 430. Cephalis small, subspherical, with distinct collar septum, and the same network as the thorax, ■with numerous bristle-shaped horns of the same length. Thorax slenderly conical, twice as long as broad, with irregular, polygonal pores of little different sizes, and very thin bars. Surface covered with perpendicular, simple, bristle-shaped spines, about as long as the cephalis. Dimensions. — Cephalis 0-02 diameter, thorax 012 long, 0-22 broad. Habitat. — Central Pacific, Stations 266 to 272, surface. EEPORT ON THE RADIOLAKIA. 1297 25. SetJiocouiis venosus, ii. sji. (PI. 55, fig. 2). Phhhararhninm venosiiw, Haeckel, 1S81, Prodromus, p. 430, et Atlas, loc. cif. CepliaKs subsjiherical, with a stout, prismatic horn twice the length, bearing three denticu- late edges. The uppermost part of the thorax is supported by three diverging, radial beams arising from the deep collar stricture. Thorax wide, conical, nearly twice as long as broad, with slightly convex, thorny outUnes ; its delicate network is composed of very irregular, polygonal meshes of different sizes, separated by stronger bars, and of numerous very small polygonal pores separated by very thin bars inside the former. The central capsule of the figured specimen exhibited in the upper third of the thorax four large club-shaped lobes, which arose from a very small sphere enclosed in the cephalis and containing the nucleus. Dijiunsions. — Cephalis 0'02 long, O^OS broad ; thorax 0"4 long, 0'3 broad. Rahitat. — Central Pacific, Station 271, surface. Genus 573. Periar actinium,^ Haeckel, 1881, Prodromus, p. 430. Definition. — Setliocorida (vel Dicyrtida eradiata aperta) with conical or cam- panulate, gradually dilated thorax, and widely open mouth. Primary lattice - shell enveloped by an external arachnoidal mantle. Cephalis with one or more horns. The genus Periarachnium has been derived from those forms of the preceding Sethoconus, in which the conical thorax is covered with simple spines {Phlebarachnium) or branched spines [Cladarachnium). By communication of the branches of these spines a second outer shell is formed, which, like an arachnoidal mantle, envelops the inner primary shell. 1. Periarachnmm periplectum, n. sp. (PI. 55, fig. 11). Cephahs hemispherical, separated from the thorax by a sharp collar stricture, from which arise three internal, diverging beams supporting its upper third. Thorax campanulate, conical, about as long as broad, with shghtly convex outlines. The delicate lattice-work of the entire shell is double ; the inner composed of subregular, hexagonal meshes ; the outer of larger, irregular, polygonal meshes. The bars of the inner are much thicker than the thin threads of the outer. Both shells are connected by numerous bristle-shaped beams. The central capsule of the figured specimen exhibited in the upper part of the thorax three club-shaped lobes, which arose from a sphere enclosed in the cephahs and containing the nucleus. I)mensions.^Ce^ha.]is 0"02 long, O^OS broad ; thorax O'lo long, 012 broad. Rahitat. — Central Pacific, Station 271, surface. 'Periar(ic/tnium = Shell enveloped by cobweb; ■xi^i, liiiaxiiay. (ZOOL. CHALL. EXF. — PART XL. — 1886.) Rr 163 1298 THE VOYAGE OF H.M.S. CHALLENGER. Genus 574. ySethoceijhalus,'^ Haeckel, 1881, Prodromus, p. 430. Definition. — Sethocorida (vel Dicyrtida eradiata aperta) with discoidal, flatly expanded thorax. Cephalis Large, without horn. The genus Sethocephalus (formerly proposed under the name Platycryphalus) contains some few and rare Sethocorida, distinguished by the A'ery lai'ge cephalis, the collar opening of which is wide open, not closed by cortinar beams, and surrounded by a very flat, nearly discoidal thorax, like the brim of a hat. It is possible that this peculiar genus has been derived from a Tricyrtid (TJieocalyptra f) by loss of the original cephalis, and that the apparent large cephalis is the original thorax. 1. Sethocephalus eucecryphalus, n. sp. (PI. 56, fig. 13). Cephalis very large, campanulate-conical, with irregular, polygonal pores and thin bars. Thorax short, scarcely broader than the cephalis, beyond the sharp collar stricture expanded like the brini of a hat, with few rows of irregular, polygonal pores. (In the specimen figured the thorax was only half as broad as in another specimen found afterwards.) Dimensions. — Cephalis 0'12 long, 0'09 broad; thorax 0'02 long, 012 broad. Habitat. — South Pacific, Station 285, surface. 2. Sethocephalus p>latycryphalus, n. sp. Platycryphalus sethodiscus, Haeckel, 1881, Prodromus, p. 430. Cephalis large, hemispherical, with irregular square pores and thin bars. Thorax flatly conical, three to four times as broad as the cephalis, beyond the collar stricture expanded nearly discoidally, with a delicate network of small, subregular, hexagonal pores. (Similar in general form to Scthophormis aurelia, PI. 55, fig- 3, but without any trace of collar beams or radial ribs.) Dimensions. — Cephalis 0'04 long, 0'08 broad ; thorax 0'04 long, O'o broad. Habitat. — South Pacific, Station 289, surface. Genus 575. Sethocyrtis,^ n. gen. Definition. — S e t h o c o r i d a (vel DicjTtida eradiata aperta) with ovate or subcylindrical thorax, the mouth of which is constricted, simple, without prominent hyaline peristome. Cephalis with an apical horn. ' iSeJ/ioc(;pfe«ZMS= Sieve-head ; ariiu, y.i(pcthyi. '^ Se(/!.oc!/rf?s = Sieve-basket; ; oiiSu, xv^rii. REPORT ON THE RADIOLARIA. 1299 The genus Sethocyrtis and the three following nearly allied genera differ from the three preceding genera of Sethocorida in the form of the thorax, which is not gradually dilated, conical, but cylindrical or ovate, with more or less constricted mouth. ♦Sc^/iocj/j-i/s may be derived from Anthocyrtis by loss of the terminal feet. Its mouth is quite simple, without tubular or annular peristome. 1. Sethocyrtis oxycephalis, n. sp. {PL 62, fig. 9). Shell rough, subcouical, with slight collar stricture. Length of the -two joints = 4:9, breadth = 3 : 8. Cephalis ovate, with a pyramidal horn of half the length. Thorax campanulate, with regular, circiilar pores, twice as broad as those of the cephaUs. Mouth constricted, scarcely half as broad as the thorax. Dimensions. — Cephalis 0'04 long, 0'03 broad ; thorax 0-09 long, O'OS broad. Habitat. — Central Pacific, Stations 263 to 274, depth 2350 to 3000 fathoms. 2. Sethocyrtis cancrina, Haeckel. Eucyrtidium cancrinum, Ehrenberg, 1875, Abliandl. J. k, Akad. d. Wiss. Berlin, p. 70, Taf. x. fig. 4. Shell smooth, bottle-shaped, with obliterated coUar stricture. Length of the two joints = 4 : 9, breadth = 2 : 7. Cephalis subcylindrical, with a stout conical horn of the same length, and some- times a smaller accessory horn at its base. Thorax ovate, truncate, with regular, circular, quin- cuncial pores, twice as broad as those of the cephalis. Moutli little constricted, flat, nearly as broad as the thorax. Dimensions. — Cephalis 0-04 long, 0'02 broad ; thorax 0"09 long, 0'07 broad. Habitat. — Fossil in Barbados. 3. Sethocyrtis diomedis, n. sp. Shell thorny, pear-shaped, with slight collar stricture. Length of the two joints =: 3 : 16, breadth = 4:20. Cephalis hemispherical, with a conical horn of twice the length. Thorax inflate, ovate, truncate at both poles, with regular, circular pores, twice as broad as those of the thorax. Mouth constricted, flat, half as broad as the thorax. Dimensions. — Cephalis 0-03 long, 0'04 broad ; thorax 012 to 016 long, 016 to 0'2 broad. Habitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms ; also fossil in Barbados. 4. Sethocyrtis menelai, n. sp. Shell spiny, pear-shaped, with sharp collar stricture. Length of the two joints = 3:15, breadth = 4 : 18. Cephalis subspherical, with a large, cylindro-conical horn, about as long as the whole shell. 1300 THE VOYAGE OF H.M.S. CHALLENGER. Thorax inflate, subspherical, truncate, with large, irregular, roundish pores, four to six times as large as those of the cephalis. Mouth constricted, flat, one-third as broad as the thorax. Dimensions. — Cephalis 0'03 long, 0'04 broad; thorax 015 long, O'lS broad. Habitat. — Fossil in Barbados. 5. Sethocyrtis subacuta, Haeckel. Eucyrtidinm subacutum, Ehrenberg, 1872, Abliandl. d. k. Akad. d. AViss. Berlin, p. 293, Taf. vii. fig. 18. Shell smooth, pear-fshaped, with sharp collar stricture. Length of the two joints = 1:4, breadth = 1 : 3. Cephalis subspherical, with small, irregular pores and a rudimentary horn of half the length. Thorax ovate, with large, subregular, hexagonal pores and thin bars between theiu. Mouth constricted, flat, half as broad as the thorax, without prominent peristome. Dimensions. — Cephalis 0'02 long, 002 broad ; thorax 0'08 long, 0*06 broad. Habitat. — Philippine Sea, depth 3300 fathoms (Ehrenberg). 6. Sethocyrtis pleuracantha, Haeckel. Eiicijrtidium i^leumcaiifhum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 293, Taf. vii. fig. 21. Shell smooth, bottle-shaped, with distinct collar stricture. Length of the two joints = 2:4 breadth = 1:3. Cephalis slenderly ovate, with an excentric pyramidal horn of the same lengtli. Thorax inflate, ovate, with irregular, roundish pores and thin bars between them. Mouth con- stricted, flat, half as broad as the thorax, without prominent peristome. Dimensions. — Cephalis 0-04 long, 0-02 broad ; thorax 0'08 long, 0'06 broad. Habitat. — Tropical Pacific, Stations 200, 225, 266, 274, &c., at various depths. 7. Sethocyrtis agamemnonis, n. sp. (PI. 62, figs. 11, o, h). Shell pear-shaped, rough, with sharp collar stricture. Length of the two joints = 2 : 10, l)readth = 3 : 8. Cephalis subspherical, with very small pores and a small, pyramidal horn of half the length. Thorax inflate, ovate ; in the uppermost part (beyond the collar stricture) with a ring of six to nine very large roundish pores, which are twice to four times as broad as the other irregular, roundish pores. (The shell is seen in fig. 11 from the apical pole, in fig. 11a with the cephalis, in fig. 11 J without it, exhibiting the four central collar pores of the cortinar septum.) Mouth truncate, without prominent peristome. Dimensions. — Cephalis 0-02 long, O'OS broad ; thorax 01 long, 0-08 broad. Habitat. — North Pacific, Station 244, depth 2900 fathoms. REPORT ON THE EADIOLARIA. 1301 8. Sethocyrtis cassis, Haeckel. Cuniutdla casng, Ehrenborg, 1834, Mikrogeol., Taf. xxii. fig. 38. CyHocalpis cassis, Haeckel, 1862, Monogr. d. Eadiol., p. 287. Shell pear-shaped, smooth, with obliterated collar stricture. Length of the two joints = 4 : 13, breadth = 3 : 12. Cephalis ovate, with a conical horn of half the length. Thorax inflate, ovate, with subregular, circular, quiucuncial pores, twice to three times as broad as the bars. Mouth con- stricted, truncate, two-thirds as broad as the thorax, without prominent peristome. Dimensions. — Cephalis 0'04 long, 0"03 broad ; thorax 013 long, 012 broad. Habitat. — Fossil in Tertiary rocks of Sicily (Caltanisetta). Genus 576. SetJiocorys,^ Haeckel, 1881, Prodromus, p. 430. Definition. — Se t h o c o ri dii (vel Dicyrtida eradiata aperta) with ovate or sub- cyKndrical thorax, the mouth of which is constricted and prolonged into a ring-like peristome. Cephalis with an apical horn. The genus Scthocorys differs from the preceding Sethocyrtis, its ancestral form, in the form of the constricted mouth, which is prolonged into a prominent, hyaline, tubular, or annular peristome. 1. Sethocorys achiUis, u. sp. (PI. 62, fig. 8). Shell rough, pear-shaped, with distinct collar stricture. Length of the two joints = 4 : 8, breadth = 3:8. Cephalis ovate, with a stout pyramidal horn of half the length. Thorax nearly spherical, with regular, circular, quincuncial pores of the same breadth as the cephalic pores. Mouth constricted, half as broad as the thorax, with a broad, smooth, striated peristome. Dimensions. — Cephalis 0'04 long, 0'03 broad ; thorax 0'08 long, O'OS broad. Mahitat. — Cosmopolitan ; Mediterranean (Corfu), Atlantic, Indian, Pacific ; many stations, at various depths. 2. Sethocorys patrocli, n. sp. Shell thorny, pear-shaped, with slight collar stricture. Length of the two joints = 4 : 12, breadth = 3 : 10. CephaHs ovate, with a pyramidal horn of twice the length. Thorax ovate, truncate at both poles, with regular, circular pores, twice as broad as the cephalic pores. Mouth constricted, half as broad as the thorax, with a broad, smooth, prominent peristome. Dimensions. — Cephalis 0'04 long, 0'03 broad ; thorax 012 long, 01 broad. Halitat. — Central Pacific, Stations 2G3 to 274, depth 2350 to 3000 fathoms. 1 Rethocorys -- Sieve-helmet ; ciidu, xoov;. 1302 THE VOYAGE OF H.M.S. CHALLENGER. 3. Sethocorys armadillo, Haeckel. Eucyrtidium armadillo, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. ix. fig. 10. Shell slenderly ovate, smooth, with deep collar stricture. Length of the two joints = 3 : 10, breadth = 4:6. Cephalis ovate, at the apex thorny, with a conical horn of the same length. Thorax smooth, ovate, truncate, with small, regular, circular pores, disposed in from twelve to fifteen transverse rows of the same breadth as the cephalic pores. Mouth constricted, half as broad as the thorax, with a broad, hyaline, prominent peristome. Dimensions. — ^Cephalis 0'03 long, 0-04 broad ; thorax 01 long, 0'06 broad. Habitat. — Fossil in Barbados. 4. Sethocorys odysseus, n. sp. (PL 62, fig. 10). Shell ovate, smooth, with obliterated collar stricture. Length of the two joints = 2:9, breadth = 4:8. Cephalis hemispherical, with a slender, conical horn of the same length. Thorax nearly spherical, with regular, circular pores, of the same breadth as the cephalic pores, quincun- cially disposed. Mouth constricted, only one-third as broad as the thorax, with a broad, hyaline, prominent peristome. Dimensions. — Cephalis 0-02 long, 0"04 broad ; thorax 0-09 long, 0'08 broad. Hahitat. — Central Pacific, Station 272, depth 2600 fathoms. 5. Sethocorys ami^hora, Haeckel. Lophophcena ainpliora, Stbhr, 1880, Palseontogr., vol. xxvi. p. 99, Taf. iii. fig. 11. Shell ovate, mouth with distinct collar stricture. Length of the two joints=l:5, breadth = 2:4. Cephalis hemispherical, with a short conical horn of half the length. Thorax ovate, truncate, with small, regulai-, circular, quincuncial pores. Mouth constricted, half as broad as the thorax, with a narrow, prominent, hyaline peristome. Dimensions. — Cephalis O^OIS long, O'OS broad ; thorax 0'07 long, 0'06 broad. Habitat. — Fossil in Tertiary rocks of Sicily ; Grotte (Stohr). 6. Sethocorys ajacis, n. sp. Shell slenderly ovate, smooth, without external collar stricture, but with an internal septum. Length of the two joints = 1:3, breadth = 1:2. Cephalis conical, with a large pyramidal horn of twice the length, and sometimes with a smaller accessory horn at its base ; its pores scarce, irregular. Thorax ovate, truncate, hyaline, in the greater part without pores, in the smaller part REPORT ON THE RADIOLARIA. 1303 with from two to four transverse rows of small, circular pores only. Moutli constricted, with a large cylindrical, tubular, hyaline peristome, half as long as the shell. Bimoisions. — Cephalis 003 long, 0'04 broad ; thorax 0-09 long, 0-07 broad. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. Genus 577. LojyhophcBna,^ Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Definition. — Sethocoi'ida (vel Dicyrtida eradiata aperta) with ovate or sub- cylindrical thorax, the mouth of which is either truncate or constricted. Cephalis armed with several large horns. The genus LophophcBua differs from the nearly allied Sethocorys and Dictyocephalus only in the armature of the large cephalis, which bears a group of large horns, often arranged in a corona of radial spines. Sometimes these spines are connected by anastomosing branches (like Arachnocorys). Subgenus 1. Lophophcenula, Haeckel. Definition.— Yiovws of the cephaUs simple, free, radial spines, neither branched nor connected. 1 . Lopliophcena galea, Ehrenberg. Lopliophmna galea orei, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 245. Lophophcena apieulaia, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. viii. fig. 11. t Gffrnutella spiniceps, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. ii. fig. 6. Shell with slight collar stricture. Length of the two joints = 5:4, breadth = 5:6. CephaKs subglobular, with numerous bristle-shaped, radial spines, about as long as its radius. Thorax about the same size, truncate, conical, smooth, with wide open mouth. Pores in both joints of equal size, small, regular, circular. Dimensions. — ^^Cephalis 0'05 long, 0'05 broad ; thorax 0'04 long, O'OG broad. Habitat. — Tropical Atlantic,- Station 348, depth 2450 fathoms ; also fossil in Barbados. 2. Lophophcena radians, Ehrenberg. LophophcBna radians, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. viii. fig. 9. ILophoplwBiia lynx, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berhn, p. 78, Taf. viii. fig. 13. Shell with shght coUar stricture. Length of the two joints = 4:6, breadth = 4:5. CephaHs subglobular, with numerous, stout, conical, radial spines, about as long as its diameter. Thorax ' iopAoptena = Shell with a top-knot ; Ao'^Joj, foilau. 1304 THE VOYAGE OF H.M.S. CHALLENGER. of about the same size, subcylindrical, smooth, truncate, with wide open mouth. Pores in both joints of equal size, small, regular, circular. Dimensions. — Cephalis 0'04 long, 0-04 broad ; thorax 0'06 long, 0'05 broad. Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific ; also fossil in Barbados. 3. Lojjhojyhcena liothorax, ii. sp. Shell with distinct collar stricture. Length of the two joints = 4 : 10, breadth = 4 : 8. Cephalis subglobular, with large, circular, hexagonally-framed pores, and with numerous stout, conical, radial spines, about as long as its diameter. Thorax twice as long, ovate, smooth, truncate, with little con- stricted mouth, and with irregular, roundish pores, of very different sizes. Dimensions. — Cephalis 0"04 long, 0"04 broad ; thorax O'l long, 0'08 broad. Ealitat. — Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms. 4. Loj^hophcena ecMnocephala, n. sp. Shell with deep collar stricture. Length of the two joints = 4:8, breadth = 4:9. Cephalis subglobular, of the same shape as in the preceding species. Thorax thorny, inflate, nearly spherical, with a constricted mouth of half the breadth, and with irregular, roundish, double- contoured pores. Dimensions. — Cephalis 0^04 long, 0'04 broad ; thorax 0'08 long, 0'09 broad. Hahitat. — North Pacific, Station 253, depth 3125 fathoms. Subgenus 2. Lophopluenoma, Haeckel. Definition. — Horns of the cephalis connected by anastomosing branches. 5. Lopliophcena circumtexta, Haeckel. Loplioplixna radians, var., Ehrenberg, 1875, Abbandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. viii. figs. 7, 8. Shell with slight collar stricture. Length of the two joints = 4:5, breadth = 4:5. Cephalis subglobular, with numerous conical, radial spines, about as long as its diameter, and at equal distances from the surface, connected by anastomosing branches. Thorax nearly cylindrical, smooth, little dilated towards the truncate, wide open mouth. Pores subregular, circular. Dimensions. — Cephalis 0'04 long, 0'04 broad ; thorax 0'05 long, 0'05 broad. Habitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms ; also fossil in Barbados. REPORT ON THE RADIOLARIA. 1305 Genus 578. Dictyocephalus,^ Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 830. Definition. — Sethocorida (vel Dicyrtida eradiata aperta) with ovate or sub- cylindrical thorax, the mouth of which is more or less constricted, either truncate or with a ring-like peristome. Cephalis rounded, without horn. The genus Dictyocephalus has originated probably from Sethocorys by reduction and loss of the apical horn. The mouth is more or less constricted, either simple, truncate [Dictyocryphalus) , or provided with a prominent, broad, hyaline, annular peristome {Dictyoprora). Subgenus 1. Dictyoprora, Haeckel, 1881, Prodromus, p. 430. Definition. — Mouth of the thorax constricted, with a prominent, ring-like or tubular, hyaline peristome. 1. Dictyocephalus amphora, n. sp. (PI. 62, fig. 4). Shell smooth, thick-walled, subovate, with shght collar stricture. Length of the two joints = 5 : 9, breadth = 6:8. Cephalis large, obtusely conical, with numerous oblique pore-canals. Thorax inflate, with six to eight transverse rows of roundish pores, increasing in size towards the base. Mouth constricted, one-third as broad as the thorax, with an internal diaphragm and a narrow hyaline peristome. Dimensions. — Cephalis 0"05 long, 0"06 broad; thorax 0'09 long, 0'08 broad. Habitat. — Central Pacific, Stations 265 to 272, depth 2425 to 2925 fathoms. 2. Dictyocephalus urceolus, n. sp. 1 Eucyrtidium Mongolfieri, Bury, 1862, Polycystins of Barbados, pi. v. fig. 2. Shell smooth, thick-walled, urceolate, with obUterated collar stricture. Length of the two joiats = 5:12, breadth = 4 : 10. Cephahs campanulate, with numerous obUque pore-canals. Thorax inflate, with five or six transverse rows of roundish pores of equal size. Mouth constricted, nearly half as broad as the thorax, with a broad hyaline peristome. Dimensions. — Cephahs 0'05 long, 0'04 broad; thorax 0"12 long, Ol broad. 5a5itoi.— Central Pacific, Station 268, depth 2900 fathoms; also fossil in Barbados. 1 -Dic<2/oc«pAaiws= Latticed head; IUtvou, xeipax*. (ZOOL. CHALL, EXP. — PART XL. — 1886.) Rl 164 1306 THE VOYAGE OF H.M.S. CHALLENGER. 3. Dictyocephalus excellens, Haeckel. Eucyrtidium excellens, Ehrenberg, 1875, Abhandl. d. k. Akad. d. "Wiss. Berlin, p. 70, Taf. x. fig. 2. Shell annulate, thick-walled, urceolate, with slight collar stricture. Length of the two joints = 5 : 10, breadth = 4 : 7. Cephalis large, ovate-conical, with numerous oblique pore- canals. Thorax ovate, with ten to twelve transverse rows of regular, roundish pores, which are separated by prominent annular ribs. Mouth constricted, about half as broad as the thorax, with a broad hyaline jjeristome. Dimensions.- — Cephalis O'Oo long, 0'04 broad ; thorax O'l long, 0'07 broad. Habitat. — Fossil in Barbados. 4. Dictyocephalus oceUatus, Haeckel. Dictyocephalus ocellatus, Haeckel, 1862, Monogr. d. EadioL, p. 297. ? Eucyrtidium ocellatum, Ehrenberg, 1861, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 299. Shell smooth, thick-walled, with deep collar stricture. Length of the two joints = 3 : 9, breadth = 4 : 7. Cephalis subspherical, with numerous oblique pore-canals. Thorax inflate, campauulate, hyaline, only with three or four remote transverse rows of circular, double-contoured pores of equal size. Mouth constricted, one-third as broad as the thorax, with a narrow hyaline annular peristome. Dimensions. — Cephalis 0"03 long, 0'04 broad; thorax 0"09 long, 0'07 broad. Habitat. — North Atlantic, Greenland ; Fiieroe Channel (Gulf Stream), John Murray. 5. Dictyocephalus crassiceps, Haeckel. Eucyrtidium crassiceps, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xi. fig. 4. Shell smooth, thick-walled, with sharp collar stricture. Length of the two joints = 4 : 6, breadth = 3:4. Cephalis ovate, in the upper part with scattered pores, in the lower part with one transverse row of pores. Thorax hyaline, subcyUndrical, only with four or five remote transverse rows of small, circular pores. Mouth constricted, half as broad as the thorax, with a short hyaline peristome. Dimensions.— Ge-^\\2i\\s 0"04 long, O^OS broad ; thorax O-QG long, 0'04 broad. Habitat. — Fossil in Barbados. 6. Dictyocephalus australis, n. sp. (PI. 62, fig. 1). • Shell smooth, thick-walled, with slight collar stricture. Length of the two joints = 2 : 9, breadth = 3 : 6. Cephalis hemispherical, with few small pores. Thorax subcylindrical, with large, REPORT ON THE RADIOLARIA. 1307 roundish, double-contoured pores, irregularly disposed. Mouth constricted, two-thirds as broad as the thorax, with a broad, hyaline peristome. Dimcnsioiis. — Cephalis 0'02 long, 0"03 broad ; thorax O'OO long, O'OG broad. Habitat. — East coast of Australia, Station 164, surface. 7. Dictyocephalus mediterraneiis, n. sp. (PI. 62, fig. 2). Shell rough, thin-walled, with slight collar stricture. Length of the two joints = 3 : 10, breadth = 4 : 8. Cephalis hemispherical, with small, circular pores. Thorax ovate, truncate, with much larger circular pores of different sizes and thin bars between them. Mouth little constricted, two-thirds as broad as the thorax, with a narrow, hyaline peristome. Dimensions. — Cephalis 0'03 long, 0'04 broad ; thorax 01 long, 0'08 broad. Hahitat. — Mediterranean, Smyrna (Haeckel), surface. 8. Dictyocephalus papillosus, Haeckel. Hucyrtidium papillosum, Etrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 293, Taf. vii. fig. 10. Shell thin-walled, papillate, with obliterated collar stricture. Length of the two joints = 2:7, breadth =3:5. Cephalis hemispherical, with small, circular pores. Thorax slenderly ovate, with larger, subregular, circular pores, separated by oblique series of conical papillae. Mouth with a broad, hyaline peristome (the " third articulus " of Ehrenberg), separated by a stricture from the little broader thorax. Dimensions. — Cephalis 0-02 long, 0"03 broad ; thorax 0'07 long, 0"05 broad. Hahitat. — "Western Tropical Pacific (Philippine Sea), depth 3300 fathoms. 9. Dictyocephalus tabulatus, n. sp. Shell thin-walled, papillate, with obliterated collar stricture. Length of the two joints = 2 : 10, breadth = 3:7. Cephalis hemispherical, with small, circular pores. Thorax slenderly ovate, truncate, with large, subregular, circular, hexagonally-framed pores. Mouth little constricted nearly as broad as the thorax, with a broad, hyaline peristome. Dimensions. — Cephalis 0'02 long, 0'03 broad ; thorax 01 long, 0'07 broad. Hahitat. — Central Pacific, Station 271, depth 2425 fathoms. 1 0. Dictyocephalus reticulum, Haeckel. Dictyoeephalxis reticulum, Haeckel, 1862, Monogr. d. Radiol., p. 297. Eucyrtidium reticAilum, Ehrenberg, 1861, Monatsber. d. k. preuss. Akad. d. "Wiss. BerHii, p. 300. Shell thin-walled, smooth, with deep collar stricture. Length of the two joints = 2 : 8, breadth = 3 : 5. Cephalis subspherical, with small, circular pores. Thorax campanulate, with 1308 THE VOYAGE OF H.M.S. CHALLENGER. transverse rows of alternating square pores. Mouth little constricted, nearly as long as the thorax, with a narrow, prominent peristome. Dimensions. — Cephahs 0-02 long, 003 broad ; thorax O'CS long, 0-05 broad. Habitat. — Arctic Ocean, Greenland (Schaffher) ; Iceland (Krabbe). 11. Dictyocephalus ampulla, n. sp. Shell thin-waUed, smooth, with slight coUar stricture. Length of the two joints = 1:4, breadth = 1 : 3. Cephahs subspherical, without pores, hyahne. Thorax inilate, subspherical, with scarce and small, widely-scattered, chcular pores. Mouth constricted, only one-third as broad as the thorax, with a narrow, prominent peristome. Dimensions. — Cephahs 0-02 long, 0-02 broad ; thorax O'DS long, 0-07 broad. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. Subgenus 2. Dictyocryphalus, Haeckel, 1881, Prodromus, p. 430. Definition. — Mouth of the thorax flat or truncate, without prominent ring-like peristome. 12. Dictyocephalus obtusus, Ehrenberg. Didyocephalus obimiis, Ehi-enberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 830. Lophoplimia ohtusa, Ehrenberg, 1854, Mikrogeol., Taf. xxii. fig. 40. Cornutella obtusa, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 877. Dictyocephalus obtusus, Haeckel, 1862, Monogr. d. Eadiol., p. 296. Shell smooth, thick-walled, with distinct collar stricture. Length of the two joints = 5:6 breadth = 4:5. Cephahs ovate, httle smaller than the subcylindrical thorax. Pores subregular, circvdar, of httle different sizes. Mouth truncate, without ring-like peristome. Dimensions. — Cephahs O'Oo long, 0'04 broad ; thorax 0'06 long, 0'05 broad. Habitat. — Fossil in Tertiary rocks of Sicily (Caltanisetta), Grotte, &c. 13. Dictyocephalus glohiceps, n. sp. (PL 62, fig. 7). SheU rough, thin-walled, with distinct collar stricture. Length of the two joints = 6:8, breadth = 6:7. Cephahs subspherical, large, with circidar, double-contoured pores. Thorax cylindrical, with in'egular, roundish pores, the size of which, hke the thickness of the wall, decreases gradually towards the truncate mouth, which has no ruig-hke peristome. Dimensions. — Cephalis 0'06 long, 0'06 broad ; thorax, 0'08 long, G'07 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. REPORT ON THE RADIOLARIA. 1309 14. Dictyocephalus cavea, n. sp. Shell rough, thiii-waUed, with slight collar stricture. Length of the two joints = 3 : 10 = breadth = 5:7. Cephalis hemispherical, thorny, with numerous regular, circular pores. Thorax subcylindrical, with very large, circular, hexagonally-framed pores (in nine longitudinal alternating rows), three to five times as broad as the cephalic pores. Mouth truncate, wide open, without ring-like peristome. DimcTisions. — Cephalis 0'06 long, O'l broad ; thorax 0-2 long, 0"14 broad. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 15. Dictyocephalus ccipito, Elirenberg. Didyocephaltis capita, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 289, Taf. vii. fig. 24. Shell smooth, thin-walled, with sharp collar stricture. Length of the two joints = 7:9, breadth = 6:8. CephaHs ovate, with numerous irregular, roundish, densely - crowded pores. Thorax ovate, with very few widely-scattered, irregular, roundish pores (broken off in Ehrenberg's figure), Mouth truncate, little constricted, without ring-like peristome. Dimensions. — Cephalis 0-07 long, O'OG broad ; thorax 0"09 long, 0"08 broad. Hahitat. — Western Tropical Pacific (PhOippine Sea) Station 206, depth 2100 fathoms. 16. Dictyocephalus hispidus, Ehrenberg. " Dictyocephalus hispidus, Ehrenberg, !Monatsber. d. k. preuss. Akad. d. Wiss. Berhn ; Abhandl. d. k. Akad. d. Wiss. Berlin, 1872, p. 289, Taf. v. fig. 18. Shell rough, thin- walled, with deep collar stricture. Length of the two joints =3:4, breadth = 3:5. Cephalis subspherical, spiny, with the same irregular, roundish pores as the funnel-shaped or nearly ovate thorax. Mouth truncate, little narrower than the thorax, without ring-like peristome. Dimensions. — Cephalis 003 long, 0-03 broad ; thorax 0'04 long, 0-05 broad. Hahitat. — Tropical Atlantic, Mexican Gulf (Ehrenberg) ; Station 338, depth 1990 fathoms. Subfamily 2. Sethocapsida, Haeckel, 1881, Prodromus, p. 433. Definition. — S e th ocy r t i da witb the basal mouth of the shell fenestrated (vel Dicyrtida eradiata clausa). 1310 THE VOYAGE OF H.M.S. CHALLENGER. Genus 579. Setliocapsa,'^ Haeckel, 1881, Prodromus, p. 433 (sensu emendato). Definition. — S ethocapsida (vel Dicyrtida eradiata clausa) with a free cephali bearing an apical horn. The genus Sethocapsa and the two following genera represent together the small subfamily of Sethocapsida, or those Dicjrrtida in which the mouth of the thorax is closed, and no radial apophyses are present. Sethocapsa may be derived either from Lithopera hj loss of the three radial rods, or from Sethocyrtis by closure of the mouth. 1. Sethocapsa pyriformis, n. sp. (PI. 57, fig. 2). Shell rough, pear-shaped, with slight collar stricture. Length of the two joints = 3:10, breadth = 3:8. Cephalis subspherical, with numerous small pores, and a short pyramidal or conical horn of half the length. Thorax ovate, with subregular, circular, quincuncial pores. Dimensions. — Cephalis 0'03 diameter, thorax 01 long, 0'08 broad. Habitat. — Central Pacific, Stations 263 to 274, depth 2350 to 3000 fathoms. 2. Sethocapsa lagena, Haeckel, lAtliopera lagena, Ehrenberg, 1875, Abhandl. d. k. Akad. d. "Wiss. Berlin, p. 78, Taf. iii. fig. 4. Shell smooth, pear-shaped, with sharp collar stricture. Lengtli of the two joints = 3:8, breadth = 3:6. Cephalis pear-shaped, with few scarce pores, and a small conical horn of half the length. Thorax pear-shaped, with irregular, roundish pores. This species differs fi-om the similar Lithopera lagena almost only in the complete absence of the three internal radial collar beams inside the thorax, and may be derived from it by their retrograde metamorphosis. Dimensions. — Cephalis 0'03 diameter, thorax 0'08 long, 0'06 broad. Habitat. — Fossil in Barbados. 3. Sethocapsa macroceros, n. ep. Shell smooth, pear-shaped, with slight collar stricture. Length of the two joints = 2 : 11, breadth = 2:9. Cephalis subspherical, with small circular pores, and a very large, straight, pyra- midal horn, of about the same length as the shell. Thorax ovate, with large, irregular, roundish pores, which are surrounded by polygonal frames. Dimensions. — Cephalis O'OS diameter, thorax Oil long, O'OO broad. Habitat. — Central Pacific, Station 270, depth 2925 fathoms. 1 SeiAocaysa = Sieve-cap.?ule ; o^^s, x.i-^». REPORT ON THE RADIOLARIA. 1311 4. Setliocapsa nidus, Ilaeekel. Lithopera 7iitlus pcndulits, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iii. fig. 7. Shell smooth, pear-shaped, with distinct collar stricture. Length of the two joiuts = 3:6, breadth = 3 : 5. Cephalis subspherical, with a large, straight, pyramidal horn of twice the length, and scarce smaU pores. Thorax ovate, also with very small and scarce pores. Divicnswns. — Cephalis 0'03 diameter, thorax O'OG long, 0'05 broad. Habitat. — Fossil in Barbados. _ 5. Setliocapsa bulla, n. sp. Shell spiny, with slight collar stricture. Length of the two joints = 3 : 12, breadth = 4 : 12. Cephalis hemispherical, with small, scarce pores, and a conical horn of the same length. Thorax nearly spherical, with large, subregular, circular, quincuncial pores, twice as broad as the bars. Dimensians. — Cephalis O'Oo long, 004 broad ; thorax 012 long, 012 broad. jBaJite^.— Central Pacific, Station 268, depth 2900 fathoms ; fossil in Barbados. 6. Sethocapsa ampulla, n. sp. Shell papillate, with slight collar stiicture. Length of the two joints = 1:5, breadth = 1:5. Cephalis hemispherical, hyaline, without pores, with a large pyramidal horn of twice the length. Thorax nearly spherical, with large, ii-regular, roundish, lobulated pores. Dimensions. — Cephalis 0"03 long, 0^04 broad; thorax 015 long, 015 broad. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 7. Sethocapsa staurocephala, Haeckel. ^Lithopera oxystauros, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iii. fig. 6. "i Lithopera amhlystauros, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berhn, p. 78, Taf. iii. fig. 5. Shell smooth, with slight collar stricture. Length of the two joints = 3:4, breadth = 3:4. Cephalis • large, ovate, with a conical horn of the same length, small scarce pores, and an internal frontal septimi, composed of two crossed beams, a vertical and a horizontal. Thorax little larger than the cephalis, ovate, with irregular, small and scarce pores. (The two figures of Ehrenberg are either incomplete — in Lithopera amhlystauros, the cephalic horn, and in Lithopera oxystauros, the basal part of the thorax, being broken off — or they belong to different B o t r y o d e a). Dimensions. — Cephalis 0'03 diameter, thorax 0'04 diameter. Habitat. — Fossil in Barbados. 1312 THE VOYAGE OF H.M.S. CHALLENGER. Genus 580. Dicolocapsa,^ Haeckel, 1881, Prodromus, p. 433 (sensu emendato). Definition. — S ethocapsida (vel Dicyrtida eradiata clausa) with a free cephalis, without apical horn. The genus Dicolocapsa differs from the preceding Sethocapsa in the loss of the apical horn, and therefore bears to it the same relation that Dictyocephalus does to Sethocyrtis. 1. Dicolocapsa microcephala, n. sp. (PI. 57, fig. 1). Shell smooth, thin-walled, with distinct coUar stricture. Cephalis small, subspherical, with small, crowded pores. Length of the two joints = 1:3, breadth =1:3. Thorax also nearly spherical, three times as large as the cephalis, with small, irregularly scattered, circular pores, and much broader bars. DimensioTis. — CephaUs 0'03 diameter, thorax 0'09 diameter. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 2. Dicolocajjsa megacephala, n. sp. Shell smooth, thin-walled, with sharp collar stricture. Cephalis large, conical, obtuse. Length of the two joints = 5:9, breadth = 6:8. Thorax ovate, truncate, with hemispherical base. Pores of both joints equal, subregular, circular, about as broad as the bars. Dimensions. — Cephalis 0'05 long, 0"06 broad ; thorax 0"09 long, O'OS broad. EaMtat. — Central Pacific, Station 272, depth 2600 fathoms. 3. Dicolocapsa platycephala, n. sp. Shell papillate, thick-walled, with slight collar stricture. Cephalis flat, hemispherical, hyaline, without pores (or with few small pores). Length of the two joints = 2 : 11, bi'eadth = 4 : 9. Thorax ovate, with small, regular, circular pores, half as broad as the bars. Dimensions. — Cephalis 0'02 long, 0'04 broad ; thorax O'll long, 0'09 broad. Habitat. — Fossil in Barbados. Genus 581. Cryj^tocajjsa,^ Haeckel, 1881, Prodromus, p. 433. Definition. — S ethocapsida (vel Dicyrtida eradiata clausa) with a cephalis hidden in the thorax, without apical horn. ^ Dicolocapsa = Two-iointei capsule ; oixuho;, xd^x. 2 Cj-i/piocajjsa = Hidden capsule ; x^vktos, ".a-^ce. REPORT ON THE RADIOLARIA. 1313 The genus Crijptocapsa differs from the preceding Dicolocapsa, its ancestral form, iu the peculiar shape of the ccphalis, which is nearly perfectly enclosed iin the upper part of the inflated thorax. It has, therefore, to the latter the same relation as Carpocanium bears to Anthocyrtis. 1. Cryptocapsa bacca, n. sp. Cephalis spherical, with small circular pores enclosed in the upper part of the thorax, which is ovate, smooth, and exhibits regular, circular pores, about as broad as the bars. Dimensions. — Cephalis 0"03 diameter, thorax 015 long, 0'12 broad. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 2. Cryptocapsa pila, u. sp. Cephalis spherical, with few small pores, enclosed in the upper part of the thorax, which is pear-shaped, spiny, and exhibits subregular, hexagonal pores, three times as broad as the bars. From each hexagon corner a small thorn arises. Dimensions. — Cephalis 0'04 diameter, thorax 0'25 long, 0"17 broad. Habitat. — Central Pacific, Station 269, depth 2900 fathoms. Section III. TEICYETIDA, Haeckel, 1881, Prodromus, p. 426, 434. Definition. — Cyrtoidea trithalamia, with three-jointed shell, composed of cephalis, thorax, and abdomen, with two separating transverse constrictions, an upper collar, and a lower lumbar constriction. Synopsis of the Families and Subfamilies of Tricyrtida. Family LXV. Podocyrtida. Three radial apophyses. Family LXVI. Phormocyrtida. Numerous radial apophyses. Family LXVII. Theocyrtida. No radial apophyses. r Mouth open, ( Mouth closed, ( Mouth open, ( ilouth closed, i Mouth open, ( Mouth closed. (ZOOL. CHALL. EXP. PAET XL. 1886.) Theopilida. Theoperida. Theophormida. Theophsenida. Theocorida. Theocapsida. Er 165 1314 THE VOYAGE OF H.M.S. CHALLENGER. Family LXV. P odo c yktid a, n. fam. (PL 67, 68, 71-73). Theopilida et Theoperida, Haeckel, 1881, Prodromus, p. 435, 436. Definition. — T r i c y r t i d a triradiata. (Cyrtoidea with a three-jointed shell, divided by two transverse constrictions into cephalis, thorax, and abdomen, and bearing three radial apophyses.) The family P o d o c y r t i d a, composed of the Theopilida and Theoperida of my Prodromus, comprises those Cyrtoidea in which the lattice-shell is three-jointed and triradial, bearing three external apophyses. The two subfamilies differ in the shape of the basal mouth, which in the Theopilida is a simple wide opening, in the Theoperida closed by a lattice-plate. The latter are derived from the former by development of this closing plate. The phylogenetic origin of the Podocyrtida may be found in the Tripocyrtida, from which they are derived by development of an abdomen. But there are also some forms, which may be derived directly from the Plectoidea, and the origin of some other forms seems to be doubtfuL The Podocyrtida represent one of the largest groups of Cyrtoidea, very rich in numerous species, which are partly very common and widely distributed. A large number of living and fossil species has already been described and figured by Ehrenberg, (1872, 1879, loc. cit.). These mainly belong to his genera Podocyrtis, Pterocanium, Rhopalocanium, Lithornithium, &c., and many of them are very characteristic and common forms, in which the triradial structure of the three-jointed shell is visible at first view. We distinguish here twenty genera and one hundred and fifty species. The majority have a shell with a simple wide open mouth (Theopilida, fourteen genera and one hundred and eighteen species), in the minority the mouth is closed by lattice- work (Theoperida, six genera and thirty -two species). The three joints of the shell have in the majority of Podocyrtida such a proportion that the cephalis is the smallest, the abdomen the largest, and the thorax between them intermediate in size. The cephalis bears almost constantly an apical horn ; this is rarely reduced or lost ; sometimes two or more horns are developed. The three radial apophyses arise originally from the base of the cephalis, and may from this point run along the shell-wall embedded in the lattice-plate of the thorax and the abdomen. They leave the latter at very different points, and form either lateral wings or terminal feet, sometimes both together. They are either solid or latticed, sometimes also branched, and of very various shape. Often only the three terminal feet surrounding the mouth have remained, whilst the ribs have disappeared. Many species of this large family are very variable and connected with other different species by numerous transitional forms ; the distinction of the genera described is also often very difficult. REPORT ON THE RADIOLARIA. 1315 Syno2:)sis of the Genera of Podocyrtida. I. Subfamily Theopilida- (Podocyrtida aperta.) Terminal mouth of the shell a simple wide opening. II. SubfamUy Theoperida. (Podocyrtida clausa.) Terminal mouth of the shell closed by a lattice-plate. A. Three free limbs or wings on the thorax (partly also on the abdo- men). No free ex- ternalappen- dages on the abdomen. Three wings of the thorax - solid. ' Wings arising from the thorax, Three ribs enclosed in the wall of the thorax, . Wings arising free from the collar stricture, Wings not prolonged T,, . c into the cephalis, ihree wings oi ■ r ' the thorax , ^-.t- i j latticed. n\|ngs prolonged [ into the cephalis. Free appen dages on the ■ abdomen. Three ribs pro- longed into three termi- nal feet. Ribs and feet solid. Ribs and feet lat- ticed. Three free f Wings and wings on the | solid, . thorax. Nu- '^'ometheus, ii. sp. Shell tower-shaped, very similar to the preceding species in form and fenestration, but more slender and different in the longer and three-sided prismatic abdomen. Length of the three joints = 1:1:8, breadth = 1:3:7. Cephalis with two large divergent horns of three times the length, which are tmited by interior prolongations with the basal central point, from which arise the upper edges of the three divergent wings ; the ends of the latter are directed downwards. Mouth with a corona of about thirty irregular, triangular feet. Dimensions. — Length of the three joints, a 0-03, h 0-03, c 0-25 ; breadth, a O'OS, h O'OS, c 0-2. Habitat. — Tropical Atlantic, Station 347, surface. Genus 591. Pleuropodium,^ Haeckel, 1S81, Prodromus, p. 43G. Definition. — Theopilida (vel Tricyrtida triradiata aperta) without ribs in the thorax, but with three ribs enclosed in the abdomen, which are prolonged into three terminal feet. The genus Pleuropodium, formerly confounded with TheojMdium and Pterocanium, differs from these two closely allied ancestral genera in the localisation of the three lateral ribs, which have disappeared in the thorax and become limited to the abdomen. It is therefore intermediate between the former and the following Podocyrtis. 1. Pleuropodium clmryhdeutn, Haeckel. Pterocanium cJiaei/ldeum, J. MiiUer, 1858, Aliliandl. d. k. AkaJ. d. Wiss. Berlin, p. 43, Taf. vi. figs. 7-10. Poelocyrtis charyldea, J. MiiUer, 1856, Monatsbor. d. k. preuss. Akad. d. "Wiss. Beiliu, p. 492. Shell campanulate, armed with scattered, bristle-shaped spines, with sharp collar and slight lumbar stricture. Length of the three joints = 1:3:1, breadth = 1 : 4 : 5. Cephahs cupola- shaped, with a large prismatic, somewhat curved horn, half as long as the shell. Thorax hemi- spherical, spiny. Abdomen short and wide, three-sided prismatic, with three stout longitudinal ribs, which are prolonged into three slender, prismatic, nearly vertical, slightly curved feet, about as long as the shell. Pores irregular, roundish, of variable size. Dimensions. — Length of the three joints, a 0-02, h O'OG, c O'OS ; breadth, a 003, h OllS, c Ol. Habitat. — Mediterranean (Messina, Nice, &c.), surface. 2. Pleuropodlutn cortliia, n. sp. Shell campanulate, smooth, with two distinct strictures. Length of the three joints = 1:4:2, breadth = 1:3:4. Cephalis subspherical, with a small, pyramidal, straight horn of the same length. ' PJtiuropo(Ziit)7i = Sliell with ribs and feet ; TrXfi/ja, ■sohiov. REPORT ON THE RADIOL ARIA. 1337 Tliorax pear-shapeil, with regular, circular, liexagoually-framed pores. Abdomen three-sided pyramidal, with irregular, roundish pores and three prominent, stout, prismatic ribs, which are prolonged into three straight, divergent feet of the same length. Dimensions. — Length of the three joints, a 0-02, h O'OS, c 0-04 ; breadth, a 0-025, b O'OG, c O'OS. Hahitat. — Xorth Atlantic, Station .354, surface. Genus 592. Podocyrtis,^ Ehrenberg, 1847, Monatsber. cl. k. preuss. Akad. d. Wiss. Berlin, p. 54. Definition. — Theopilida (vel Tricyrtida triradiata aperta) with three simple, terminal feet on the mouth of the abdomen, without lateral ribs or wings. Apex with a horn, which usually is simple. The genus Podocyrtis, and the two following closely allied genera, differ from all the preceding Theopilida in the absence of lateral ribs or wings, and the possession of three free terminal feet, which arise directly from the peristome, or from the margin of the abdominal mouth. They may be derived from PleuroiJodium by reduction and loss of the three piercing lateral ril >s, the terminal free prolongations of which only remain. The genus Podocyrtis is one of the largest and most common among all C y r t o i d e a, being rich mainly in fossil forms. Ehrenberg in his Polycystins of Barbados (1875, loc. cit., p. 80) enumerated not less than thirty-one species. Some of these are yet living, and occur in the Pacific Eadiolarian ooze collected by the Challenger. Other new forms are to be added, so that the number of species described in the following pages amounts to forty-five. Many of these are cosmopolitan, or at least common and widely distributed. To facilitate study we may divide this large genus into four subgenera : in two of these the terminal feet are divergent, or nearly parallel ; in the two others convergent. In each of these two groups the pores of the thorax and the abdomen are either nearly equal in size and form, or distinctly different, the abdominal pores being often much larger than the thoracic. The small cephalis bears constantly an apical horn, which is usually simple, rarely branched. Subgenus 1. Podocyrtarium, Haeckel. Definition. — Feet divergent (the distance between theii' ends being greater than that between their bases). Pores of the thorax and abdomen nearly equal in size and similar in form. * Podocyrtis = 'Ba&kti with feet ; xoil?, j-.v^tI;. (ZOOL. CHALL. EXP. — PART Wu — 1886.) Rr 168 1338 THE VOYAGE OF H.M.S. CHALLENGER. 1. Podocyrtis trij)odiscus, n. sp. (PL 72, fig. 4). Shell nearly conical, gradually dilated from the apical to the basal part, with two slight strictures. Surface a little rough. Length of the three joints = 1 : 2:4, breadth = 2:4:6. Pores subregular, circular, quincuncially disposed, of nearly equal size in the conical thorax and the subspherical abdomen. Ce^jhaKs hemispherical, with smaller pores and a spindle-shaped spiny horn of twice the length. Feet cylindrical, as long as the abdomen, little divergent, their ends curved outwards and thickened into a papillate knob. Dimensions. — Length of the three joints, a 0-02, h 0-03, c 0-08 ; breadth, a 0'03, h 0-07, c Oil. Habitat. — Central Pacific, Station 265 to 272, depth 2425 to 2926 fathoms. 2. Podocyrtis attenuata, Elirenberg. Podocyrtis attenuata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xvi. fig. 5. Shell nearly conical, gradually dilated from the apical to the basal part, with two slight strictures. Sui-face a little rough. Length of the three joints = 2 : 3: 4, breadth = 2: 4: 5. Pores subregular, circular, equal, quincuncial. Cephalis subspherical, with a conical horn of twice the length. Feet cylindrical, as long as the abdomen, little divergent (sometimes as in the specimen figured, nearly parallel). Dimensions. — Length of the three joints, a 0-015, h 0'03, c 0-04 ; breadth, a 0'02, b 0-04, c 0-05. Habitat. — Fossil in Barbados. 3. Podocyrtis thyrsoceras, n. sp. Shell slender, conical, smooth, very similar to Thyrsocyrtis rhizodon, Ehrenberg (1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xii. fig. 1), with two slight strictures, nearly of the same form and fenestration as in the preceding smaller species. Length of the three joints = 1:2: 3, breadth = 1: 3 : 4. Cephalis subspherical, with a large cylindrical straight horn, which reaches the length of the abdomen, and is papillate in the distal half. Feet cylindrical, divergent, nearly as long as the whole shell, broadened and spinulated at the distal end. Dimensions. — Length of the three joints, a 0-02, b 004, c 0-06 ; breadth, a 0-02, b 0-06, c 0-08. Habitat. — South Pacific, Station 295, depth 1500 fathoms. 4. Podocyrtis conica, u. sp. Shell conical, without external strictures, but with two internal septal rings . Surface papillate. Length of the three joints = 2 : 3 : 8, breadth = 3 : 6 : 10. Pores equal, subregular, circular, quincuncial. Cephalis hemispherical, with a thick conical horn of the same length. Feet conical, about as long as the thorax, divergent in the direction of the outline of the conical shell. Dimensions. — Length of the three joints, a 0-02, b 0-03, c 0-08 ; breadth, a 00-3, b 0-06, c 01. Habitat. — Cosmopolitan, Central Pacific, Stations 263 to 274 ; Tropical Atlantic, Station 348, in depths between 2350 and 2925 fathoms ; also fossil in Barbados. EEPOET ON THE RADIOLARIA. 1339 5. Podocyrtis corythceola, u. sp. (PI. 72, fig. 2). Shell ovate conical, with two deep strictures, and with rough surface. Length of the three joints = 2:5:8, breadth = 3 : 8:10. Cephalis hemispherical, thorny, with a strong oblique horn three times the length, which is armed with nine to twelve conical spines. Pores small, circular, of irregular size and distribution. Feet spindle-shaped, divergent, as long as the inflated abdomen. Dimensions. — Length of the three feet, a 0-02, h 0-05, c 0-08 ; breadth, a O'OS, h 0-08, c 01. Habitat. — Indian Ocean, Maldive Islands (Haeckel), surface. 6. Podocyrtis surena, n. sp. (PI. 72, fig. 10). Shell thin-walled, tower-shaped, smooth, with two deep strictures. Length of the three joints = 2 : 5 : 10, breadth = 3 : 10 : 11. Cephalis subspherical, with a bent conical horn, as long as the hemispherical thorax. Abdomen cylindrical. Pores subregular, circular, quincuncially disposed, and sUghtly larger in the abdomen. Feet with a thickened calf, nearly perpendicular, as long as the thorax ; their distal ends little divergent, and forming a knob beset witli small roundish tubercles. Dimensions. — Length of the three joints, a 0-02, b 0-05, c 01 ; breadth, a 0-035, b 01, c Oil. Habitat. — North Pacific, Station 241, depth 2300 fathoms. 7. Podocyrtis conulus, n. sp. SheU elongate, conical, rougli, without external strictures, but with two internal septal rings. Length of the three joints = 3 : 4 : 15, breadth = 5 : 7 : 12. Cephalis hemispherical, with a thick pyramidal horn of the same length. Feet also pyramidal, divergent, of the same size as the horn. Pores iiTCgidar, roundish, of variable size. Abdomen very long. Dimensions. — Length of the three joints, a 0-03, b 0-04, c 015 ; breadth, a 0-05, b 0-07, c 012. Habitat. — Tropical Atlantic, Station 342, depth 1445 fathoms ; also fossil in Barbados. 8. Podocyrtis tridactyla, n. sp. Shell conical, with two slight strictures, smooth. Length of the three joints = 2:6:5, breadth = 4:5:6. Cephalis hemispherical, with a pyramidal horn of twice the length. Pores irregular, polygonal, of variable size. Feet as long as the abdomen, constricted in the middle, trilobed at the distal end ; the middle lobe twice as large as the lateral lobes. Dimensions. — Length of the three joints, a 0-02, b 0-06, c 0-05 ; breadth, a 0-04, b 0-05, c O'OG. Habitat. — Indian Ocean, Madagascar; Eabbe. Subgenus 2. Podocyrtecium, Haeckel. Definition. — Feet divergent (the distance between their ends being greater than that between their bases). Pores of the thorax and abdomen of difierent form or size. 1340 THE VOYAGE OF H.M.S. CHALLENGER. 9. Podocyrtis prismatica, n. sp. (PL 72, fig. 1). Shell conical, rough, with two distinct strictures. Length of the three joints = 1:1:3, breadth = 1:2:5. Cephalis subspherical, with a curved conical horn of twice the length. Thorax and abdomen together nearly hemispherical. Pores small, regular, circulai", quincuncial, twice as large in the abdomen as in the thorax. Feet very large, twice as long as the whole shell, divergent, bent outwards, prismatic, with strong prominent edges. Dimensions. — Length of the three joints, a 0-02, b 0-02, c OOG ; breadth, a 0-02, h 0-0-4, c 01. Habitat. — Western Tropical Pacific, Station 225, depth 4175 fathoms. 10. Podocyrtis hrevipes, Ehreuberg. Podocyrtis hrevipes, Elirenberg, 1875, AbhanJl. d. k. AkaJ. d. "Wiss. Berlin, p. 80, Taf. xvi. fig. 6. SheU conical, smooth, with two slight strictures. Length of the three joints = 2 : 3 : G, breadth = 2:5:9. Cephalis subspherical, with a conical horn of the same length. Pores regular, circular, quincuncial, three times as broad in the abdomen as in the thorax. Feet short, triangular, divergent, as long as the horn. (The specimen figured by Ehrenberg was incomplete, one foot and the horn being broken off.) Dimensions. — Length of the three joints, a 0'02, b 0-03, c O'CG ; breadth, a 0'02, h 005, c 0'09. Habitat. — Fossil in Barbados. 11. Podocyrtis divergens, n. sp. (PI. 72, fig. 6). Shell slender, subconical, thick-walled, with two distinct strictures. Length of the three joints = 2:5:7, breadth = 4:8:10. Cephalis hemispherical, with a large, oblique, prismatic horn three times the length, and a small divergent by-horn at its base. Thorax hemispherical, rough, with regular, circular, quincuncial pores. Abdomen cylindrical, thorny, with larger circular pores of subregular disposition, two to three times as broad as those of the thorax. Feet conical, horn-like, bent, as long as the abdomen ; strongly divergent in the distal half. Dimensions. — Length of the three joints, a 0-02, b 0-05, c 0-07 ; breadth, a O'Ol, b O'OS, c 01. Habitat. — Western Tropical Pacific, Station 220, depth 1100 fathoms. 12. Podocyrtis collar is, Ehreuberg. Fodocyriis collaris, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82; Taf. xvi. fig. 1. Shell conical, with slight collar and deeper lumbar stricture. Length of the three joints = 1:4:4, breadth = 1:4:8. Cephalis hemispherical, with a small oblique liorn of the same length. Pores regular, circular, quincuncial, four to six times as broad in the inflated abdomen as in the conical thorax. Feet short and slightly divergent, little longer than the cephalis. Dimensions.— Length of the three joints, a 0-02, b 0-07, c O'OS ; breadth, o O'Oo, b O'OS, c 016. Habitat. — Fossil in Barbados. REPORT ON THE RADIOLARIA. 1341 13. Podocyrtis veniricosa, Ehrenberg. Podocyrtis veniricosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xvi. fig. 3. Shell conical, with two deep strictures, thorny. Length of the three joints = 1:2:5, breadth = 1:4:8. Cephalis subspherical, with a small conical horn of the same length. Pores regular circidar, quincuncial, four to six times as broad in the inflated abdomen as in the hemispherical thorax. (Pores much larger and less numerous than in the similar preceding species.) Feet broad and stout, triangular, divergent, as long as the thorax. Divicnsions. — Length of the three joints, a 0-02, I 0-04, c Ol ; breadth, a 0-025, I O'OV, c 016. Habitat. — Fossil in Barbados. 14. Podocyrtis flosculata, u. sp. (PL 72, fig. 9). Shell conical, rough, as broad as long, with distinct coUar, but obliterated kunbar stricture. Length of the three joints = 1:2:4, breadth = 2:4:7. Cephalis hemispherical, with a thick conical horn of the same length. Thorax truncate, conical, with small, circular, quincuncial pores. Abdomen inflated, with very large and remarkable regular, quincuncial pores ; their inner edge cu'cular, the outer six-lobed, the six lobes elegantly alternating with six short conical spines. Feet very coarse, equilateral triangular, half as broad as the thorax, little divergent. Dimensions. — Length of the three joints, a 0-02, I 0-04, c O'OS ; breadth, a 0-04, I O'OS, c 014. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 15. Podocyrtis centriscus, Ehrenberg, Podocyrtis centriscus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. AViss. Berhn, p. 80, Taf. xiv. fig. 2. Shell conical, rough, about as high as broad, with two obliterated strictures. Length of the three joints = 1 : 2 : 4, breadth = 1 : 4: 7. Cephalis small, hemispherical, with a stout conical horn. Pores of the inflated abdomen iiTCgular, roundish, very large, three occurring in the course of its length, five times as broad as the small, very numerous, regidar, circular pores of the conical thorax. Feet S-shaped, as long as the abdomen, with the blunt end curved outwards. Dimensions. — Length of the three joints, a 0-02, b 0-04, c O'OS ; breadth, a 0-02, b 0-08, c 014. Habitat. — Central Pacific, Station 266, depth 2750 fathoms ; fossil in Barbados. 16. Podocyrtis magnijica, n. sp. (PL 72, fig. 5). Shell conical, spiny, a little longer than broad, with two distinct strictures. Length of the three joints =1:2:5, breadth = 2:4:7. CephaUs hemispherical, with a large conical horn, which is as long as the abdomen, nearly scaly, and covered with short, simple, and bifid spines. Pores regular, circular, quincunciaUy disposed, four times as broad in the inflated abdomen as in th3 1342 THE VOYAGE OF H.M.S. CHALLENGEE. conical thorax. Spines of the former twice as large as those of the latter. Feet very long and slender, cylindrical, S-shaped, bent outwards at the thickened distal end, with a spindle-shaped papillate knob. Dimensions. — Length of the three joints, a 0-03, b 0-04, c 01 ; breadth, a 0-04, h 0-08, c 014. Habitat. — Canary Islands, Lanzerote, Haeckel, surface. 17. Podocyrtis jyrinccps, Ehrenberg. Podocyrtis princeps, Ehrenberg, 1875, Abhandl. d. k. AkaJ. d. Wiss. Berlin, p. 82, Taf. xiii. fig. 1. Podocyrtis jyrinceps, Biitschli, 1882, Zeitschr. f. wiss. ZooL, vol. xxxvi. p. 540, Taf. xxxiii, fig. 32. SheU conical, with two distinct strictures. Length of three joints =1:2:5, breadth = 1:4:7. CephaHs subspherical, with a large cylindrical, vertical horn, longer than the whole shell. Pores regular, cii-cular, quincuncial, in the inflated spiny abdomen very large (four to five in the course of its length), five times as broad as in the smooth conical thorax. Feet about as long as the shell, slightly bent, S-shaped, cylindrical. Divwnsions. — Length of the three joints, a 0'02, b 0'05, c 01 ; breadth, a 0'03, b O^OS, c 014. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms ; fossil in Barbados. 18. Podocyrtis euceros, Ehrenberg. Podocyrtis euceros, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xv. fig. 1. Shell conical, campanulate, with two deep strictures. Length of the three joints = 1:3:6, breadth = 2:5:7. Cephalis hemispherical, with a large, cylindrical horn, nearly as long as the shell. Pores regular, circular, hexagonally framed, quincuncial, four times as broad in the papiUated, inflated abdomen as in the hemispherical, smooth thorax. Feet short and broad, triangular, divergent, about as long as the thorax. (In the specimen figured by Ehrenberg, two feet were broken off). Dimensions. — Length of the three joints, a 0'016, b 0'05, c 01 ; breadth, a 0'03, b 0-08, c 012. Habitat. — -Cosmopolitan ; Mediterranean, Atlantic, Indian, and Pacific Oceans, at many stations, and in various depths ; fossil in Barbados. 19. Podocyrtis cristata, n. sp. (PL 72, fig. 7). Shell conical-campanulate, thorny, with two deep strictures. Length of the three joints = 1:2:5, breadth = 2 : 4 : 7. Cephalis subspherical, with a large, oblique, httle bent, conical horn, as long as the abdomen. Thorax hemispherical, papillate, with small, regular, circular pores. Abdomen inflated, with very large, circular pores, (three to four in its length), six times as broad as those of the thorax, and separated by hexagonal, serrated crests. Feet cyhndrical, stout, S-shaped, slightly divergent, with a spherical papillate knob at the distal end. Drincnsimis.— Length of the three joints, a 0^02, b 0-04, c 01 ; breadth, a 0-035, b 0-07, c 014. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. REPORT ON THE RADIOL ARIA. 1343 20. Podocyrtis schomhitrgkii, Ehreuberg. Podoeyrtis schmnJmrgkii, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 22; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 82, Taf. xiv. fig. 7. Shell ovate-conical, with two distinct strictures. Length of the three joints = 2:5:10, breadth = 3 : 8 : 12. Cephalis hemispherical, with a large, straight, conical horn as long as the abdomen. Thorax campanulate, smooth, with small, regular, circular pores. Abdomen inflated, papillate, with very large, regular, hexagonal pores (three to four in the course of its length), five times as broad as their bars and as the pores of the thorax. Feet as long as the abdomen, nearly parallel, slightly bent outwards at the conical distal end. Dimensiotis. — Length of the three joints, a 0-02, h 0-05, c Ol ; breadth, a 0-0.3, h 0-08, c 012. Habitat. — Fossil in Barbados. 21. Podocyrtis hexagonalis, n. sp. Shell nearly ovate, slender, everywhere covered with a regular network of high, hexagonal, denti- culated crests, separating the circular, funnel-shaped pores, which are twice as large in the sub- spherical abdomen as in the hemispherical thorax, between both of which are two deep strictures. Length of the three joints =1:3:6, breadth = 2:5:6. Cephalis hemispherical, with a long and thin cylindrical, vertical horn, as long as the abdomen. Feet of the same length and form, nearly straight, slightly divergent. Dimenswns. — Length of the three joints, a 0-02, h 0-06, c 012 ; breadth, a 0-04, h O-Qll, c 013. Habitat. — North Pacific, Station 244, depth 2900 fathoms. . 22. Podocyrtis ovata, u. sp. Shell nearly ovate, papillate, without external strictures. Length of the three joints = 1:2:3, breadth = 2:4:5. Cephalis hemispherical, with a pyramidal horn half as long as the shell. Pores regular, circular, hexagonally framed, three times as broad in the inflated abdomen as in the conical thorax. Feet pyramidal, little bent, divergent, about as long as the thorax. Dimcnsiom. — Length of the three joints, a 0-025, h O'Oo, c 0-08 ; breadth, a Q-Oo, h 0-095, c 0-12. Habitat. — Mediterranean, Corfu, Haeckel, surface. 23. Podocyrtis tirceoldta, n. sp. 1 Podocyrtis mitra. Bury, 1862, Polycystins of Barbados, pi. v. fig. 3. Shell nearly ovate, smooth, with two deep strictures. Length of the three joints = 1:2:6, breadth = 2:4:5. Cephalis subspherical, with a stout, conical horn of the same length. Thorax flat, hemispherical, with four to six transverse rows of small circular pores. Abdomen urceolate, 1344 THE VOYAGE OF H.M.S. CHALLENGER. with four to five transverse rows of very large, subregular, hexagonal pores. Feet short and thick, bent outwards, as long as the thorax. Dimensions. — Length of the three joints, a 0'025, h 0'05, c 015 ; breadth, a 005, h O'l, c 013. Habitat. — Central Pacific, Station 2G5, depth 2900 fathoms ; fossil in Barbados. 24. Podocyrtis ehrenbergii, Haeckel. Podocyrtis amphiacantlia, Ehrenherg, 1875, AblaantU. d. k. AkaJ. J. Wiss. Berlin, p. 80, Taf. svii. fig. 3. Shell slender, ovate, smooth, with deep collar, but evanescent lumbar stricture. Length of the three joints = 1:3:2, breadth = 1:3:3. CephaHs subspherical, with a large conical horn, as long as the campanulate thorax. Abdomen nearly cylindrical. Pores irregular, roundish, two to four times as large in the abdomen as in the thorax. Feet conical, slender, divergent, nearly as long as the shell. (In the imperfect specimen figured by Ehrenberg, two spines were broken off.) Dimensions. — Length of the three joints, a 0'02, h 0'06, c 0'04 ; breadth, a 0'02, h 0'06, c O'OG. Habitat. — North Pacific, Station 253, depth 3125 fathoms ; fossil in Barbados. 25. Podocyrtis arguhis, Ehrenberg. Podocyrtis argidus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xvi. fig. 2. Shell slender, ovate, or subconical, with two deep strictures. Length of the three joints = 1:2:4, breadth =1:3:4. Cephahs hemispherical, with a small conical horn of the same length (broken off in the figure of Ehrenberg). Pores regular, circular, three times as broad in the inflated abdomen as in the campanulate thorax. Feet spindle-shaped, slender, divergent, about as long as the thorax. Dimensions. — Length of the three joints, a 0'025, b O'Oo, c Ol ; breadth, a 0-03, h 0'07, c O'l. Habitat. — Tropical Atlantic, Station 247, depth 2530 fathoms ; also fossil in Barbados. Subgenus 3. Podocyrtidium, Haeckel. Definition. — Feet convergent {tlie distance between their ends being smaller than that between their bases). Pores of the thorax and abdomen nearly equal in size and similar in form. 26. Podocyrtis papalis, Ehrenljerg. Podocyrtis ■papalis, Ehrenberg, Mikrogeol., Taf. xxxvi. fig. 23 ; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 82, Taf. xv. fig. 6. Shell ovate, smooth, without external stricture. Length of the three joints = 1 : 3 : 1, breadth =1:3:3. Cephalis ovate, with a stout pyramidal horn of twice the length. Thorax and REPORT ON THE RADIOLARIA. 1345 MAPIME B!01.CG!CAL LABORATORY " librar" WOODS HOLE, Ml W. H. 0. I. abdomen with about thirty longitudinal, divergent ribs, separating the same number of longitudinal rows of regular, circular pores, the size of which increases gradually towards the base. Feet shovel- shaped (broad, triangular, with convex outer and concave inner side, the obtuse end being curved inwards), about as long as the short abdomen, only slightly convergent. Bimcmions. — Length of the three joints, a 004, h 0'12, c 0'04; breadth, a 0'04, h 012, c O'll. Hahitat. — Fossil in Barbados. 27. Podocyrtis costata, u. sp. Shell ovate, smooth, of the same form and structure as Podocyrtis papalis, but with two distinct strictures and dififerent proportions. Length of the three joints =1:3:6, breadth = 2:4:6. About thirty longitudinal ribs regularly alternating with rows of circular, regular pores. Feet as in Podocyrtis papalis. Dimensions.— L%ngi\\ of the three joints, a 0-02, 6 0-06, c 012 ; breadth, a 0-04, h O'OS, c 012. Habitat. — Central Pacific, Stations 266 to 272, depth 2425 to 2925 fathoms. 28. Podocyrtis mitrella, Elirenberg. Podoci/rtis mitrella, Ehienberg, 1875, Abhandl. d. k. Akad. d. "Wiss. Berlin, p. 82, Taf. xv. fig. 3. Shell ovate, smooth, nearly of the same form and structure as Podocyrtis ptapalis, but different in the proportions of the joints, m the much smaller, regidar pores, and in the great breadth of the shovel-shaped, blunt, about semicircular feet. Length of the three joints = 2 : 9 : 4, breadth = 3 : 10 : 3. Cephalis subspherical, with a thick pyramidal horn of the same length. Slight collar, but no lumbar stricture. Dimensions. — Length of the three joints, « 0'02, l 0'09, c 0'04 ; breadth, a 0'03, h 01, c 0'03. Hahitat. — Fossil in Barbados. 29. Podocyrtis mitra, Ehrenberg. Podocyrtis mitra, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 20; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 82, Taf. xv. fig. 4. Shell ovate, conical, smooth, with two slight strictures. Length of the three joints = 1:2:3, breadth = 1:3:4. Cephalis with the horn (of equal length) conical. Pores regular, circular, in about twenty longitudinal rows, slightly increasing in size in the middle part of the abdomen. Feet shovel-shaped, blunt, slightly divergent, only as long as the cephalis. Dimensions. — Length of the three joints, a 0-025, b 0'5, c O'V ; breadth, a 0-03, h 0-075, c O'l. Habitat. — Cosmopolitan ; Mediterranean (Gibraltar), Canary Islands, Central Pacific, Stations 265 to 274, in different depths ; also fossU in Barbados. (ZOOL. CHALL. EXP. PART XL. — 1886.) Er 169 1346 THE VOYAGE OF H.M.S. CHALLENGER . 30. Podocyrtis argus, Ehrenberg. Podocyrtis argus, Ehrenberg, 1875, Abbandl. d. k. Akad. d. "Wiss. Berlin, p. 82, Taf. xvi. fig. 9. Shell ovate, with two distinct strictures, smooth. Length of the three joints = 1:3:4, hreadth = 1:4:5. Cephalis subcorneal, with a conical horn of the same length. Thorax cam- panulate. Abdomen inflated. Pores subregular, roundish, of nearly equal breadth, quincuncial. Feet shovel-shaped, triangular, nearly vertical, only as long as the cephalis. Dimensions. — Length of the three joints, a 0-02, h 0-06, c 0-08 ; breadth, « 0-025, l 0-08, c 01. Habitat. — Tropical Atlantic, Station 347, surface ; fossil in Barbados. 31. Podocyrtis eulophos, Ehrenberg. Podocyrtis euloplios, Ehrcaberg, 1875, Abliandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xiv. fig. 6. Shell subcorneal, slender, with two slight strictures, smooth. Length of the three joints = 1:2:6, breadth = 2:4:6. Cephalis hemispherical, with a large, spiadle-shaped, angular horn of twice the length. Thorax hemispherical. Abdomen truncate, conical. Pores subregular, roundish, in about twenty longitudinal rows, their breadth gradually increasing towards the base. Feet shovel-shaped, blunt, nearly vertical, only as long as the cephalis. Dimensions. — Length of the three joints, a 0'025, h 0"05, c 016 ; breadth, a O'Oo, h O'OS, c 014. Hahitat.-^'Fossil in Barbados. 32. Podocyrtis favosa, n. sp. Shell ovate, with two slight strictures, and with honeycomb-like surface. Length of the three joints = 1:5:2, breadth = 2:6:5. Cephalis hemispherical, with a pyramidal horn of twice the length. Thorax hemispherical. Pores regular, circular, hexagonally framed, funnel-shaped, with high, prominent crests between them. Feet shovel-shaped, little convergent, triangular, as long as the abdomen. Dimensions.— J^ewgih. of the three joints, a 0'02, l 01, c 0'04 ; breadth, a 0'04, h 012, c Oil. Hahitat. — South Pacific, Station 300, depth 1375 fathoms. 33. Podocyrtis fusiforinis, n. sp. Shell slender, nearly spindle-shaped, diminishing gradually from the broadest middle part (immediately above the lumbar septimi) towards the two poles. Length of the three joints = 1:5:8, breadth = 2:6:5. Cephalis subspherical, with a large conical horn three times the length. Thorax and abdomen with twenty-four to thirty denticulated, longitudinal ribs, separating the same number of longitudinal rows of regular, circular pores. Instead of the lumbar stricture, a broad, internal septum occurs. Feet slender, straight, as long as the abdomen, only slightly convergent. Dimensions. — Length of the three joints, a 0-03, h 01, c 016 ; breadth, « O'Oo, I 012, c 01. Habitat. — Indian Ocean, Madagascar (Kabbe) surface. REPORT ON THE RADIOLARIA. 1347 Subgenus 4. Podocyrtonium, Haeckel. Definition. — Feet convergent (the distance between their ends being smaller than that between their bases). Pores of the thorax and abdomen different in size or form. 34. Podocyrtis 2^edicellaria, n. sp. (PI. 72, fig. 8). Shell conical, ovate, with two very slight strictures. Length of the three joints = 2:3:8, breadth = 2:4:8. Cephahs conical, with a pyi-amidal horn of the same length. Pores subregular, circular, quincuncially disposed, two to three tunes as broad in the smooth abdomen as in the rough, spinulate thorax. Feet as long as the thorax, shovel-shaped (broad, triangular, with convex outer and concave inner side, the free ends being curved inwards), only shghtly convergent. Dimensions. — Length of the three joints, a 0-04, h 0-05, c 016 ; breadth, a O'OS, h O'OQ, c OIG. Hahitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms. 35. Podocyrtis sinuosa, Ehrenberg. Podoctjrtis sinuosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berhn, p. 82, Taf. xv. fig. 5. Podocyrtis sinuosa, Biitschli, 1882, Zeitschr. f. wiss. Zool., vol. x.xxvi. p. 540, Taf. xxxiii. fig. 33. Shell slender, conical, with shght collar, but without lumbar stricture. Length of the three joints = 1:2:4, breadth = 1 : 2 : 4. Cephalis subspherical (in the figure of Ehrenberg broken off), with a pyramidal horn of the same length. Pores subregular, circular, four times as broad in the abdomen as in the thorax. Peet shovel-shaped, as long as the thorax. Dimensions.— 'Le.wgih. of the three joints, a O'O.j, h 0-06, c 012; breadth, a O'OS, h 0-06, c 012. Hahitat. — Fossil in Barbados. 36. Podocyrtis florihunda, n. sp. Shell ovate, conical, with two very shght strictures. Length of the three joints = 2:3:6, breadth =2:4:7. Between twenty-four to thirty longitudinal, denticulated ribs lie the same number of subregular pores, which are flower-like, lobed, or rosette-shaped, and two to three times as large in the abdomen as in the thorax. Feet shovel-shaped (as in the similar Podocyrtis pedicellaria (PI. 72, fig. 8). Dimensions. — Length of the three joints, a 0-03, h O'OS, c 012 ; breadth, a O'Cl, h 0-08, c 014. Habitat. — Tropical Atlantic, Station 342, depth 1445 fathoms ; also fossil in Barbados. 37. Podocyrtis scaphopodia, n. sp. Shell conical, rough, with two slight strictures. Length of the three joints = 2:3:5, breadth = 2:4:8. Cephalis subspherical, with a pyramidal horn of twice the length. Poi'es subregular. 1348 THE VOYAGE OF H.M.S. CHALLENGER. circular, quincuncial, four times as large in the abdomen as in the thorax. Feet short and broad, triangular, shovel-shaped, with convergent ends. This species is similar to Podocyrtis hrevipes, but differs in the form and size of the horn and of the feet. Dimensions. — Length of the three joints, a 0-02, h O'OS, c 0-05 ; breadth, a 0-02, I 0-04, c 0-08. Habitat. — Central Pacific, Stations 263 to 274, depth 2350 to 2925 fathoms. 38. Podocyrtis lithoconus, n. sp. (PL 72, fig. 3). Shell conical, thick-walled, smooth, with two sKght strictures. Length of the three joints = 2:3:6, breadth = 2:4:7. CephaUs hemispherical, with a spindle-shaped horn of the same length. Pores subregular, circular, two to four times as broad in the abdomen as in the thorax. Feet triangular, shovel-shaped, nearly vertical, as long as the cephalis. Dimensions. — Length of the three joints, «■ 0-03, h 0-06, c 012 ; breadth, « 0-04, I 0-08, c 0-14. Habitat. — Central Pacific, Station 270, depth 2925 fathoms. 39. Podocyrtis a,m23la, Ehrenberg. Podocyrtis ampla, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80,Taf. xvi. fig. 7. Shell conical, thick-walled, with distinct collar, but without lumbar stricture. Length of the three joints = 1:4:5, breadth =1:6:7. Cephalis hemispherical, with a large conical horn, as long as the thorax. Pores regular, circular, quincuncial, three times as broad in the rough abdomen as in the smooth thorax. Feet very small, shovel-shaped, only as long as the cephalis. Dimensions.- — Length of the three joints, a 0-02, b 0-08, c 01 ; breadth, a O'Oo, b 012, c 014. Habitat. — North Atlantic (Florida) ; also fossil in Barbados. 40. Podocyrtis nana, Ehrenberg. Podocyrtis nana, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xvii. fig. 2. Shell conical, thorny, with two distinct strictures. Length of the three joints = 1:3:3, breadth = 2:5:6. Cephalis hemisiDherical, with a large cylindrical horn, nearly as long as the shell. Pores in the abdomen irregular, roundish, two to four times as broad as the regular, circular, quincuncial pores of the thorax. Feet very small, shovel-shaped, scarcely as long as the cephalis. Dimensions. — Length of the three joints, a 0-01, b O'Oo, c 01)3 ; breadth, a 0-02, b 0-05,c'0-06. Habitat. — South Atlantic, Station 335, depth 1425 fathoms ; also fossil in Barbados. 41. Podocyrtis lycea, Haeckel. Thyrsor.ijrtis lijwa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wis.'^. Berlin, p. 84, Taf. xii. fig. 3. Shell ovate, conical, with two deep strictures. Length of the three joints = 2:5:8, breadth = 3:8:9. Cephalis hemispherical, with a large conical horn, which is spinulate, scaly, and as REPORT ON THE RADIOLARIA. 1349 long as the abdomen. Pores subregular, circular, two to four times as broad in the smooth abdomen as in the spiny tliorax. Feet very short and broad, shovel-shaped, scarcely as long as the cephalis. Dimensions.— Length of the three joints, a 002, b 0-05, c 0-08 ; breadth, a 003, b 0-08, c 0-09. Habitat. — Fossil in Barbados. 42. Podocyrtis hromia, Haeckel. Thyrsocyrtis hromia, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xii. fig. 2. Shell ovate, thorny, with two distinct strictures. Length of the three joints = 2:5:5, breadth = 3:8:9. Cephalis subspherical, with a large conical horn, which is half as long as the shell, and spirally dentated in the distal half. Thorax conical, spinulate, with regular, circular, quincuncial pores. Abdomen tuberculate, with a small number of very large irregular pores. Feet short, shovel-shaped, nearly vertical, as long as the cephalis. Dimensions. — Length of the three joints, a 0-02, b 0-05, c 0-05 ; breadth, a O'OS, b 0-08, c 0-09. Habitat. — Fossil in Barbados. 43. Podocyrtis sphcerogaster, n. sp. Shell inversely ovate, with two deep strictures. Length of the three joints = 1:2:6, breadth = 2:4:7. Cephalis hemispherical, with a slender, slightly bent horn, as long as the abdomen. Thorax hemispherical, spinulate. Abdomen nearly spherical, with much constricted mouth. Pores subregular, circular, hexagonally framed. Feet slender, cylindro-conical, about as long as the shell, with outer convexity, distinctly convergent. Dimensions. — Length of the three joints, a 0-02, b 0-04, c 0-12 ; breadth, a 0-04, b 0-08, c 0-14. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 44. Podocyrtis tripus, Haeckel. Podocyrtis Ucornis, Ehrenberg, 1875, Abhandl. d. k. A-kad. d. Wiss. Berlin, p. 80, Taf. xvi. fig. 8. 'tPodoeyrtis dipus, Ehrenberg, 1875,Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xii. fig. 11. Shell conical, rough, with two deep strictures. Length of the three joints = 1:2:4; breadth = 1:3:5. Cephalis subspherical, with a large, oblique, conical horn (sometimes with a small acces- sory horn at its base). Thorax hemispherical, with subregular, circular, small, quincuncial pores. Abdomen campanulate, with a small number (about twenty) of very large, irregular, polygonal pores. Feet conical, small, as long as the thorax, slightly convergent or nearly vertical. Dimensions. — Length of the three joints, a 002, b 004, c 008 ; breadth, a 0-03, b O'OG, c 01. Habitat. — Fossil in Barbados. 1350 THE VOYAGE OF H.M.S. CHALLENGER. 45. Podocyrtis triacantha, Ehrenberg. Podocyrtis triacantha, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. xiii. fig. 4. Shell conical, rough, with two di.stinct strictures. Length of the three joints = 1:2:4; breadth = 2:4:6. CejDhalis hemispherical, with a very large conical horn, nearly as long as the whole shell. Thorax campanulate, densely spinulate, with very small, regular, circular, quincuncial pores. Thorax inflated, with very large, irregular, roundish, pores (three to four in the course of its length), five to ten times as broad as those of the thorax. Feet slender and thin, subcylindrical, as long as the abdomen, divergent in the proximal half, convergent and curved inwards in the distal half. Dimensions. - Length of the three joints, a 0-02, h 0-04, c 0-08 ; breadth, a 0-04, h 0-08, c 012. Habitat. — Central Pacific, Station 268, depth 2900 fathoms ; also fossil in Barbados. Genus 593. Thyrsocyrtis,^ Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Definition. — T h e o p i 1 i d a (vel Tricyrtida triradiata aperta) with three branched terminal feet on the mouth of the abdomen, without lateral ribs or wings. Apex with a horn, which usually bears lateral spines. The genus Thyrsocyrtis differs from the preceding Podocyrtis, its ancestral form, in the ramification of the three terminal feet, which in the latter genus remain simple. 1. Thyrsocyrtis rhizodon, Ehrenberg. Thyrsocyrtis rhizodon, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. xii. fig. 1. Shell slender, conical, smooth, with two distinct strictures. Length of the three joints = 1:2:3, breadth =1:3:4. Cephabs hemispherical, with a large cylindrical horn, reaching half the length of the shell, and papillate in the distal half. Pores nearly equal, regular, circular, quin- cuncially disposed, small. Feet divergent, about half as long as the shell, broadened and forked at the distal end. (The fork incision is often much deeper, as in the figure given by Ehrenberg.) Dimensions. — Length of the three joints, a G'02, h 0'04, c 0-06 ; breadth, a O'Oo, h 0-06, c O'OS. Habitat. — Fossil in Barbados. 2. Tliyrsocyrtis arborescens, n. sp. (PI. 68, fig. 9). Shell nearly ovate, thorny, with a deep coUar, but without lumbar stricture. Length of the three joints = 1:2:4, breadth = 2 : 3:4. CephaUs hemispherical, with a stout scaly or branched horn, half as long as the shell. Pores irregular, roundish, small, separated by spinulated crests, of slightly different sizes. Feet divergent, cylindrical, and as long as the thorax in the proximal half, 1 Thyrsocyrtis = Basket with a thyrsus or apical rod ; ^v^uo;, xi/jtiV. REPORT ON THE RADIOLARIA. 1351 irregularly branched or arborescent in the distal half, with ten to thirty blunt, thickened or papillate, terminal branches. Dimensions. — Length of three joints, a 002, b 0-04, c 008 ; breadth, a O'O-i, b O'OG, c 0-08. Habitat — Central Pacific, Station 268, depth, 2900 fathoms. 3. Thyrsocyrtis fu7'cata, n. sp. Shell ovate, thorny, with two slight strictures. Length of the three joints = 1:1:3, breadth = 1:2:3. Cephalis hemispherical, with a p}Tamidal smooth horn of twice the length. Pores of the thorax and abdomen nearly equal, regular, circular, quincuncial. feet very broad, forked, about as long as the abdomen, much divergent ; the outer fork -branch as long as the simple basal half of the foot, and twice as long as the inner or axial branch. Dimensions. — Length of the three joints, a O'Oo, h 0-03, c 0-09 ; breadth, a 0-04, b 0-06, c 0-09. Habitat— Tvo\y\csl Atlantic, Station 338, depth 1990 fathoms. 4. Thyrsocyrtis rhizopus, Haeckel. Podocijrtis rhizodon, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xv. fig. 2. Shell pear-shaped, smooth, with two slight strictures. Length of the three joints -=1:2:4, breadth = 1:3:5. C'ephaHs ovate, with a stout, sword-shaped horn of the same length. Pores regular, circular, twice as broad in the inflated abdomen as in the truncate, conical thorax. Feet cylindrical, parallel, vertical, straight, divided at the distal end into two short fork -branches. Dimensions. — Length of the three joints, a Q-Q'2, b 0"04, c 0"08 ; breadth, a 0'02, h O^OG, c 0"1. Habitat — Fossil in Barbados. 5. Thyrsocyrtis rhizopodium, n. sp. (PI. 68, fig. 8). Shell campanulate-conical, with deep collar, iDut without lumbar stricture. Length of the three joints = 3 : 4 : 10, breadth = 4: 10 : 15. Cephalis subspherical, with a small conical horn of the same length. Pores regular, circular, quincuncial, three to four times as large in the inflated abdomen as in the truncate, conical thorax. Feet cylindrical, slightly divergent, about as long as the abdomen, S-shaped, bent outwards, irregularly branched in the distal half, with tuberculate terminal branches. Dimensions. — Length of the three joints, a 0-03, b 0'04, c 01 ; breadth, a 0'04, b O'l, c 015. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 6. Thyrsocyrtis radicata, Haeckel. Podocyrtis radicata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xiii. fig. 5. Shell campanulate-conical, with two distinct strictures. Length of the three joints = 1:2:4, breadth = 1:4:6. Cephalis subspherical, with a small conical horn of half the length. Pores regular, 1352 THE VOYAGE OF H.M.S. CHALLENGEE. circular, quincuncial, four to five times as broad iu tlie inflated, rough abdomen as in the campanu- late, smooth thorax. Feet cylindrical, nearly as long as the whole shell, S-shaped, bent outwards, dilated and hand-shaped at the distal end, di\'ided by three to five incisions in some in-egular finger-like branches. Dimensions. — Length of the three joints, a 0-02, h 0-04, c 0-08 ; breadth a 0-03, h O'OS, c 012. Habitat. — Fossil in Barbados. 7. Tliyrsocyrtis trifida, n. sjJ. Shell campanulate-conical, thorny, with two slight strictures. Length of the three joints = 1:2:3, breadth = 1:3:5. Cephalis subspherical, with a short pyi'amidal horn of the same length. Pores regular, circular, hexagoually framed, twice as broad in i\\e inflated spiny abdomen as in the rough, campanulate thorax. Feet very large, as long as the shell, cylindrical in the proximal simple half, in the distal half broadened and cleft into three large, irregularly lobed branches, two shorter lateral, and one longer abaxial branch ; the latter forms the prolongation of the proximal half. The outer straight edges of the three diverging feet correspond to the edges of a three-sided pyramid. Dimensions. — Length of the three joints, a 002, I O'OS, c 0-09 ; .breadth, a O'Oo, h 0-09, c 015. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. Genus 594. Dictyopodium,'^ Elirenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Definition. — T h e o p i 1 i d a (vel Tricyrtida triradiata aperta) with three latticed terminal feet on the mouth of the abdomen, without lateral ribs or wings. Apex with a horn. The genus Dictyopodium differs from the two preceding ancestral genera iu the fenestration of the three terminal feet, which in Podocyrtis are simple, in Thyrsocyrtis branched, but not latticed. 1. Dictyopodium eurylophus, Ehrenberg. Didopodium, mryloplms, Ehrenberg, 1875, Abliandl. d. k. Akad. d. Wiss. Eerhn, p. 68, Taf. xix. fig. 4. Shell campanulate-conical, thorny, with two deep strictures. Length of the three joints = 1:2:3, breadth = 1:3:4. Cephalis hemispherical, with a stout angular horn of twice the length, which at the apex is broadened and divided into some spines. Pores in the hemispherical thorax and in the truncate, conical abdomen of nearly equal size, small, subregular, circular (in the 1 Dictyopodium = Shell -with latticed feet ; o/xtuoi-, ■!r6hoi/. REPORT ON THE RADIOLARIA. 1353 abdomen sometimes more irregular and unequal). Feet as long as the abdomen, arising from it with triangular base, diverging, fenestrated throughout the entire length. Dimensions. — Length of the three joints, a O'OS, b 0-06, c O'OS ; breadth, a O'OiJ, b 0-08, c 01. Habitat. — Central Pacific, Station 263, depth 2650 fathoms ; fossil in Barbados. 2. Dictyopodimn oxylophus, Ehrenberg. Didyopodiwn oxylophus, Ehreuberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. xix. fig. 5. Shell subcorneal, smooth, with two slight strictures. Length of the three joints = 2 : 5 : 7, breadth = o : 8 : 10. Cephalis subspherical, with a small, conical, smooth horn of the same length. Pores irregular, polygonal, roundish, slightly larger in the alxlomen than iu the thorax. Feet as long as the thorax, arising from it with triangular base, diverging, fenestrated throughout the entire length. (The figures of this and the preceding species given by Ehrenberg are incomplete, having been drawn from spoiled specimens. In perfect specimens all the three feet are present and diverge in both species in tlie direction of the conical outline. The main difference between the two species is connected with the pores, wliich in Didyopodium oxyloplms are larger and more irregular, the two strictures are here not so deep.) BimensioTis. — Length of the three joints, « 0-02, b 0-05, c 0-07 ; breadth, a O'OS, b O'OS, c 01. Sabiiat. — Fossil in Barbados. 3. Dictyopodium scaphopodium, n. sp. (PI. 73, fig. 8). Shell campanulate, conical, with two deep strictures. Length of the three joints = 1:2:6, breadth = 1:4:8. Cephalis hemispherical, with a conical, smooth horn of twice the length. Thorax hemispherical, rough, with small, regular, circular pores. Abdomen inflated and papillate, with very large, polygonal or roundish pores (eight to ten times as broad as the thoracic pores) Feet divergent, nearly as long as the shell, S-shaped, bent outwards, solid and cylindrical in the proximal half, shovel-shaped and fenestrated in the distal half. 'Dimensions. — Length of the three joints, a 0-02, b 0-04, c 012 ; breadth, a 0-025, b O'OS, c 010. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 4. Dictyopodium cothurnatum, Haeckel. Podoayrtis cothurnafa, Ehrenberg, 18.54, MikrogeoL, Taf. xxxvi. fig. B. 21 ; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 82, Taf. xiv. fig. 1. Anthocyrtis cothurnata, Haeckel, 1862, Mouogr. d. Radiol., p. 310. Shell subconical, rough, with two deep strictures. Length of the three joints = 1:2:3, breadth = 1:3:5. Cephalis hemispherical, with a very large cylindrical, vertical horn, about as long as the whole shell. Thorax conical, rough, with small, regular, circular pores. Abdomen inflated, with very large, roundish pores (four to five in the course of its length), six to eight times (ZOOL. OHALL. EXP. —PART XL. — 1886.) Rr 170 1354 THE VOYAGE OF H.M.S. CHALLENGER. as large as the thoracic pores. Feet nearly vertical, only slightly divergent, S-shaped, bent, as long as the abdomen, cylindrical ; at the distal end shovel-shaped and fenestrated (often much more than in Ehrenberg's figure). Dimensions. — Length of the three joints, a 0-03, h 0-06, c O'l ; breadth, a O'OS, I 0-09, c 015. Habitat. — Fossil in Barbados. 5. Dictyopodium thyrsolophus, n. sp. (PI. 73, fig. 7). Shell subeonical, rough, with two slight strictures. Length of the three joints = 1 : 2 : 4, breadth = 1:3:6. Cephalis hemispherical, with an elegant horn, which is half as long as the shell, spindle-shaped and scaly on the distal third. Thorax hemispherical, with small, regular, circular pores. Abdomen inflated, papillate, with regular, circular pores, three times as large as the thoracic pores (five to six in the course of its length). Feet slightly divergent, cylindrical, about as long as the shell, shovel-shaped and fenestrated (with a prominent middle rib) at the distal end. Dimensions. — Length of the three joints, a 0"03, h 0-06, c 0'12 ; breadth, a 0'04, I 01, c 018. Hahitat. — Central Pacific, Station 268, depth 2900 fathoms. Subfamily 2. Theoperida, Haeckel, 1881, Prodromus, p. 436. Definition. — P odocyrtida with the basal mouth of the shell fenestrated (vel Tricyrtida triradiata clausa). Genus 595. Lithornithium,^ Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Definition. — T li e o p e r i d a (vel Tricyrtida triradiata clausa) with three solid lateral wings on the thorax. The genus Lithornithium has an ovate or spindle-shaped shell, with two distinct strictures, and tapering towards both poles. The abdomen is simple, whilst the cephalis bears an apical horn, and the thorax three free, lateral, solid, divergent wings. It may be derived from Pterocorys by development of a terminal lattice-plate closing the mouth. 1. Lithornithium ciconia, n. sp. (PI. 67, fig. 3). Shell nearly spindle-shaped, with two indistinct strictures. Length of the three joints = 1:2:4, breadth =1:3:3. Cephalis ovate, with a large pyramidal spine of twice the length. Thorax three-sided pyramidal with three pyramidal wings of the same length, the broad triangular bases of which occupy the whole length of the thoracic edges. Abdomen inversely ovate (in the 1 Lithor7tithium = Si\iceo\xs bird ; T^lSos, o^'/iHiov. IIEPORT ON THE RADIOLARIA. 1355 figured specimen broken off, iu another specimen, found afterwards, completely closed at the distal end). Pores very small, regular, circular, of equal size. Dimensions. — Length of the three joints, a 0-02, h 0-04, c O'OS ; breadth, a 0-02, b 0-OC, c 0-06. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 2. Lithornithium falco, n. sp. (PI. 67, fig. 1). Shell nearly ovate, with two sharp strictures. Length of the three joints =1:3:4, breadth = 1:4:3. Cephalis hemispherical, with a conical spine of the same length. Thorax subspherical, with three conical wings of half the length, little curved, arising with broad triangular base from the upper half of the thorax. Abdomen inversely conical. Pores irregular, roundish, of different sizes. Dimensions. — Length of the three joints, a 0-02, b O'OG, c 0-07 ; breadth, a 0-03, b 0-08, c 0-06. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 3. Lithornithium trochilus, n. sp. (PL 67, fig. 4). Shell nearly spindle-shaped, with two deep strictures. Length of the three joints = 1 : 2 : 3_ breadth = 1:3:2. Cephalis hemispherical, with a thin curved horn of the same length. Cephalis subovate, with three thin curved wings of half the length, arising with broad base from its upper half. Abdomen ovate. Pores subregular, circular, of sHghtly different sizes. DimensioTis. — Length of the three joints, a 0"015, b 0"5, c 0"06 ; breadth, a 0"02, b 0'05, c 0"04 Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 4. Lithornithium foveolatum, Ehrenberg. Lithornithium foveolatum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iv. fig. 7. Shell subovate, with two distinct strictures. Length of the three joints = 2:4:3, breadth = 3:5:4. Cephalis hemispherical, with a short conical spine of the same length. Thorax sub- spherical, with three broad triangular wings of half the length arising from its lower half. Abdomen subconical. Pores small, regular, circular, of nearly equal size. Dimensions. — Length of the three joints, a 0-02, b 0-04, c 0-03 ; breadth, a 0-03, b 0-05, c 0-04. Habitat. — Fossil in Barbados. 5. Lithornithium fringilla, u. sp. (PI. 67, fig. 2). Shell ovate, with two slight strictures. Length of the three joints = 4:7:4, breadth = 3:7:5. Cephalis ovate, with a pyramidal spine of the same length Thorax subconical, with three stout 1356 THE VOYAGE OF H.M.S. CHALLENGER. conical, curved wings of half tlie length, arising from its lower third (immediately above the girdle). Abdomen inversely campanulate. Pores subregular, circular, of equal size. Dimensions. — Length of the three joints, a 0-04, h 007, c 0-04 ; breadth, a 0-03, b 0-07, c 0-05. Eahitat. — Central Pacific, Station 272, depth 2600 fathoms. 6. Lithornithium hirundo, Ehrenberg. Litliocampe hirundo, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 65. Lithornithium hirundo, Ehrenberg, 1854, Mikrogeol., Taf. xix. fig. 53. Shell nearly ovate, with two deep strictures. Length of the three joints = 2:6:4, breadth = 2:7:5. Cephalis hemispherical, with an oblique, conical horn of twice the length. Thorax hemispherical, with three long, angular, little divergent wings of twice the length, which are S-shaped, cui-ved, and arise from its lower third, immediately above the girdle. Abdomen inversely conical. Pores irregular, roundish, of different sizes. In the figure of Ehrenberg the abdomen is broken off; in a specimen from Caltanisetta, with somewhat shorter and broader wings, I found it complete. Dimensions. — Length of the three joints, a 0-02, h 0-06, c 0-04; breadth, a 0-02, h 0-07, c 0-05. Habitat. — Fossil in Tertiary rocks of the Mediterranean (^Egina, Greece ; Caltanisetta, Sicily). Genus 596. Sethornithnim,^ Haeckel, 1881, Prodromus, p. 436. Definition. — T h e o p e r i d a (vel Tricyrtida triradiata clausa) with three Latticed lateral wincrs on the thorax. The genus Sethornithium differs from the preceding Lithornithium, its ancestral form, only in the fenestration of the three thoracic wings, and bears therefore to it the same relation that Dictyoceras exhibits to Pterocorys. 1. Sethornithium dictyopterum, n. sp. Shell ovate, with two slight strictures. Length of the three joints = 2:4:3, breadth = 1:5:4. Cephalis ovate, with a pyramidal horn of twice the length. From the middle part of the thorax arise three broad, triangular, latticed wings of about the same length, the distal end of each of which is curved downwards. Abdomen inversely conical. Pores regular, circular. (Similar to Lithornithium fringilla, PI. 67, fig. 2, but with much larger wings, which in the greater part are fenestrated.) Dinmisions. — Length of the three joints, a 0-04, 6 O'OS, c O'OB ; breadth, a 0-02, b Ol, e 0-08. Rahitat.— Central Pacific, Station 271, depth 2425 fathoms. 1 Sethornithium ^httticed bird; aiiSa, oouidot. EEPORT ON THE RADIOLARIA. 1357 Genus 597. Tlieopera} Haeckel, 1881, Prodromus, p. 436. Definition. — Tlieoperida (vel Tricyrtida trii-adiata clausa) with three lateral wings, beginning from the sides of the thorax and prolonged into the sides of the abdomen. The genus TJieopera differs from the two preceding genera in the greater extension of the three lateral wings, which are prolonged from their original base, the thorax, into the inversely conical abdomen. It has therefore an intermediate position between the preceding and the following genera. It differs from the similar Pterocanium and Tlieopodium in the closure of the constricted and fenestrated mouth. 1. Tlieopera prismatica, n. sp. (PI. 67, fig. 7). Rhopalocanium prismalicuvi, Haeckel, 1879, Atlas, pi. Ixvii. fig. 7. Shell three-sided prismatic, with three broad and long hyaline wings, which are prolonged from the coUar stricture almost to the basal end, with three parallel edges. Length of the three joints = 2 : 8 : 10, breadth = 3 : 9 : 8. Cephalis hemispherical, with a conical horn of the same length. Thorax subspherical ; abdomen inversely ovate ; pores of both small, regular, circular, of equal size. Dimensions. — Length of the three joints, a 0-02, b O'OS, c O'l ; breadth, a 0-03, h 0-09, c 0-08. Eabitat. — South Atlantic, Station 332, depth 2200 fathoms. 2. Tlieopera pyramis, Haeckel. Rhopalocanium sp., Bury, 1862, Polycystins of Barbados, pi. xviL fig. 8. Shell three-sided pyramidal, with three broad and long hyaline wings, which are prolonged from the collar stricture almost to the basal end, with three diverging edges. Length of the three joints = 3:8:11, breadth = 4 : 8 : 9. Cephahs subspherical, with a conical horn of the same length. Thorax hemispherical ; abdomen inversely campanulate. Pores in the abdomen twice to three times as broad as in the thorax, subregular, circular. Differs from the preceding species mainly in the broader pyramidal form and the divergence of the wings. Dimensions. — Length of the three joints, a 0-03, h 0-08, c Oil ; breadth, a 0-04, I O'OS, c 0-09. Habitat. — Fossil in Barbados. 3. TTieopeni fusiformis (PI. 67, fig. 5). Shell nearly spindle-shaped, rough, with two shght strictures. Length of the three joints = 2:3:6, breadth = 2 : .5 : 4. Cephalis hemispherical, large, with an obhque conical horn of the same length. Thorax hemispherical ; abdomen inversely conical. Pores irregular, roundish, of very ' Theopera = Divine pouch ; 6i6:, viioci. 1358 THE VOYAGE OF H.M.S. CHALLENGER. different sizes. Three wings short, broad, diverging, triangular, and striated, embracing at the base the lumbar stricture, the lower thuxl of the thorax and the upper third of the abdomen. Dimensions. — Length of the three joints, a 0-04, h 0-06, c 012 ; breadth, a 0-045, h 01, c 0-08. Habitat. — Central Pacific, Stations 263 to 274, depth 2350 to 2925 fathoms. 4. TJieopera luscinia, Haeckel. Lithomithium luscinia, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iv. fig. 9. Shell slenderly ovate, with distinct collar, but indistinct lumbar strictures. Length of the three joints = 1 : 3 : 6, breadth = 1:5:5. Cephalis hemispherical, with a slender cylindrical horn of three times the length, bearing a spindle-shaped spiuulate top (like a fir-cone). Pores subregular, circular, twice as broad in the abdomen as in the thorax. Three wings arising with broad triangular base, embracing the lower third of the thorax and the upper third of the abdomen, prolonged into three slender diverging spines, as long as the shell. Dimensions. — Length of the three joints a O'Olo, h 0"05, c 01 ; breadth, a 0'02, h O'OV, c 0'07. Habitat. — Fossil in Barbados. 5. Theopera chytro2nis, n. sp. (PI. 67, fig. 6). Shell slender, ovate, with distmct collar, but indistinct lumbar stricture. Length of the three joints =1:2:5, breadth = 1:3:3. Cephalis hemispherical, with a conical horn of the same length. Pores in the thorax and abdomen of similar shape, irregular, roundish. Three wings with broad triangular base attached at the upper half of the shell, in the lower half free, diverging, with a spinulate knob at the distal end. Dimensions. — Length of the three joints, a 0-025, h 0-06, c 0-15 ; breadth, a 0-03, b 0-09, c 0-09. Habitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms. 6. Theopera cortina, n. sp. (PI. 67, fig. 8). Shell slender, ovate, with distinct collar, but indistinct lumbar stricture. Length of the three joints =1:2:6, breadth 1:4:4. Cephalis subspherical, with an elegant pyramidal horn of three times the length, bearing an ovate, spinulate knob. Pores subregular, circular, two or three times as large in the abdomen as in the thorax. The three wings are slightly elevated small ribs on the thorax, arise with broad, triangular, striated bases in the upper half of the abdomen, and are pro- longed into three slender diverging feet, which are as long as the shell, and bear a spinulate, ovate knob at the distal end. Dimensions. — Length of the three jomts, a 0-02, b 0-05, c 0-13 ; breadth, a 0-03, b 0-08, c 0-08. Habitat. — Tropical Atlantic, Station 338, depth 1990 fathoms. REPORT ON THE RADIOLARIA. 1359 ■ Genus 598. Rhopalocanium,^ Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Definition. — Theopcrida (vel Tricyrtida triradiata clausa) with three Lateral wings on the sides of the inversely conical abdomen, which bears no vertical terminal horn on the basal apex. The genus Rhoiwlocanium, and the closely allied Rhopalatractus which follows, differ from the preceding Theopera, their probable ancestral form, in the origin of the three lateral wings from the inversely conical abdomen, the thorax bearing no wings. The upper part of the wing bases, which arose formerly from the thorax, is here reduced and lost. 1. Rhopalocaniuni lasamim,n. sp. (PL 67, fig. 10). Shell subovate, with two distinct strictures. Length of the three joints =1:2:3, breadth = 1:3:4. Cephalis hemispherical, with a conical, dimpled horn of twice the length. Thorax sub- conical, abdomen campanulate, both with irregular, circular pores. Three wings cyhndrical, divergent, about as long as the shell, striated, with an ovate, dimpled knob ■at the distal end, their broad triangular base being attached to the upper half of the abdomen. (Form rather variable.) Dimensions. — Length of the three joints, a 0-02, h 0-07, c 0-09 ; breadth, a 0-03, I 0-09, c 012. Habitat. — Central Pacific, Stations 263 to 268, depth 2650 to 3000 fathoms. 2. Rhopalocanium ornatum, Ehrenberg. RJiopalocanivm or»a#!«»i Ehrenberg, 1854, Mikrogeol.,Taf. xxxvi. fig. 9; Abhandl. d. k. Akad. d. "Wiss. Berlin, 1875, p. 82, Taf. xvii. fig. 8. Shell nearly spindle-shaped, with two distinct strictures. Length of the three joints = 1 : 3 : 6, breadth = 1 : 4 : 3. Cephalis hemispherical, with a stout, cylindrical horn of twice the length, bearing a dimpled cone. Thorax ovate, campanulate. Abdomen inversely conical Pores sub- regular, circular, twice as large in the thorax as in the abdomen. Three wings compressed, slender, divergent, slightly longer than the abdomen, bearing an ovate, dimpled cone at their distal end, with the broad, triangular, striated base attached to the upper third of the abdomen. Dimensions. — Length of the three joints, a 0-02, h OM, c 012 ; breadth, a 0-025, b O'OS, c 0-07. Habitat. — Fossil in Barbados. 3. Rhopalocanium cortinium, n. sp. Shell slender, ovate, nearly of the same form as, and with similar fenestration to that of Tlieo- pera cortina, (PI. 67, fig. 8). It differs from the latter mainly by the absence of the three thoracic ribs, characteristic of Tluopera. Length of the three joints = l : 2 : 6, breadth=l : 4 : 4. The ' RlwpalocanixLm='Basket with clubs ; ^6-zciMii, y.xi/iou. 1360 THE VOYAGE OF H.M.S. CHALLENGER. three wings arise by a broad, triangular, striated base from the upper half of the abdomen, below the lumbar stricture. The cephalic horn and the three divergent wings are shorter, and at tlie distal end not so much thickened as in TJieopera cortma. Dimenswns. — Length of the three joints, a 0-025, h 0-045, c 0-12 ; breadth, a 0-03, h 0-07, c O'OS. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. 4. Rlwpalocaniwm pythia, n. sp. Rhopalocanium ornatum. Bury, 1862, Polycystins of Barbados, pi. vi. fig. 1. Shell nearly ovate, with two deep strictures. Length of the three joints = 1:4:8, breadth = 1:4:4. Cephalis subspherical, with a conical horn of three times the length. Thorax inflated, abdomen inversely campanulate and prolonged into a short, conical, latticed tube. Pores sub- regular, circular. Three wings slender, as long as the abdomen, arising by a broader base from the Tippermost part of the abdomen, their thickened end being curved inwards. Dimensions. — Length of the three joints, a 0-02, h 0-07, c 0-15 ; breadth, a 0-03, h 0-08, c 0-07. Habitat. — Fossil in Barbados. 5. Rhopalocanium delphicum, n. sp. (PL 67, fig. 9). Shell nearly spindle-shaped, with two deep strictures. Length of the three joints = 1:2:4, breadth = 1:3:3. Cephalis hemispherical, with a slender, conical, curved horn, as long as the hemispherical thorax. Abdomen inversely campanulate, prolonged into a short, conical, latticed tube. Pores suhregular, circular. Three wings arising by a narrow base from the uppermost part of the abdomen, slender, cylindrical, S-shaped, curved, divergent, with a thick scaly appendix like a fir- cone at the distal end. Dimensions. — Length of the three joints, a 0-025, h 0-07, c 0-14 ; breadth, a 0-03, b 0-09, c 0-08. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. Genus 599. Rhopalatr actus} Haeckel, 1881, Prodromus, p. 437. Definition. — T lieoperida (vel Tricyrtida triradiata clausa) with three Lateral wings on the sides of the inversely conical abdomen, which bears a vertical terminal horn on tlie basal apex. The genus Rho2yalatr actus, one of the most remarkable forms of Tricyrtida, differs from the preceding Rhopalocanium, its ancestral form, in the production of a vertical, basal horn, which descends from the basal apex of the inversely conical abdomen, and is opposed to the upper apical horn of the cephalis. The shell becomes here, therefore, exc^uisitely spindle-shaped 1 iJ/wjpafotraciMS = Spindle with clubs ; pdu-a?iov, iHt^ukto;. REPORT ON THE RADIOLARIA. 1361 1. Rhopalatractus pentacanthus, n. sp, (PI. 68, fig. 11). Shell very thick-walled, witli two sharp strictures. Length of the three joints = 1 : 6 : 8, breadth = 1:6:7. Cephalis heniisplierical, with conical cavity, and a conical horn of twice the length. Thorax subspherical, separated from the abdomen by a deep lumbar stricture, with small, regular, circular, hexagonally-framed pores. Abdomen three-sided prismatic, with three strong, prominent, wing-shaped edges, which are slightly divergent towards the base, and prolonged into three pyramidal feet about as long as the thorax. Pores of the abdomen disposed in longitudinal rows, which are separated by denticulate crests. Abdominal base inversely pyramidal, and prolonged into a very large, cylindrical, basal, axial spine, nearly as long as the whole shell. Biinensions. — Length of the three joints, a 0'02, h 0'12, c 0'15 ; breadth, a 0'03, h Oil, c 014. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 2. Rhopalati'actus foveolatus, n. sp. (PI. 68, fig. 10). SheU slenderly ovate, thick-waUed, with rough, dimpled surface. Length of the three joints = 1:3:5, breadth = 2:4:4. Cephalis hemispherical, with spherical cavity, and a thick, conical spine of the same length. Thorax subspherical, with subregular, circular pores. Abdomen inversely conical, with larger, irregular, roundish pores, prolonged at the distal end into a cylindrical, axial, basal spine of about half its length. From the middle part of the abdomen arise three lateral, conical feet, which are slightly curved and divergent downwardly, scarcely as long as the basal spine. All five spines are dimpled. Dimensions. — Length of the three joints, a 0'02, b 0'06, c 01 ; breadth « 0'04, b O'OS, c O'OS. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 3. Rhopalatractus fusiformis, n. sp. Shell slender, spindle-shaped, nearly of the same form as in the preceding species. Length of the three joints = 1:2:6, breadth = 1:2:2. Cephalis subspherical, with a cylindrical horn three times the length. Pores subregular, circular, of equal breadth in the thorax and in the abdomen, which is prolonged into a cylindrical, axial, basal spine of the same length. From the upper third of the abdomen arise, from a broad triangular base, three conical wings of half the length, divergent and slightly curved mwards. Dimensions. — Length of the three joints, a 0'025, 6 Oi05, c 015 ; breadth, a O^OS, h 0'06, c 0'06. Habitat. — Central Pacific, Station 203, depth 2650 fathoms. 4. Bhopalatractus fenestratus, n. sp. (PI. 68, fig. 12). Dictyatractus fenestratus, Haeckel, 1881, Prodromus et Atlas. SlieU nearly spindle-shaped, with two distinct strictures. Length of the three joints =1:3:6, breadth = 1:4:4. Cephalis hemispherical, with a large, club-shaped horn, nearly as long as the abdomen, sulcated by longitudinal ribs, which are elegantly denticulate in the distal half. Thorax (ZOOL. CHALL. EXP. — PABT XL. — 1886.) El 171 1362 THE VOYAGE OF H.M.S. CHALLENGER. siibspherical. Abdomen subovate, prolonged into a pyramidal, axial, basal spine, half as long as the thorax. Pores subregular, circular. From the upper half of the abdomen arise three stout, lateral, divergent wings of about the same length, which are curved inwards and fenestrated both at the Ijroad triangular base and at the thickened, three-edged distal end. Dimensions. — Length of the three joints, a 0'02, l 0'06, c 0'12 ; breadth, a 0'03, b O'OS, c 0'08. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. Genus 600. Lithochytris,^ Ehrenberg, 1847, Monatsber. cl. k. preuss. Akacl. d, Wiss. Berlin, p. 54. Definition. — T heoperida (vel Tricyrtida triradiata clausa) with a three-sided pyramidal abdomen, the triangular base of which is prolonged at the three corners into three terminal feet. The genus Lithochytris diflers from all the other Theoperida in the absence of lateral wings and the possession of three divergent, terminal feet, which arise from the three corners of the three-sided pyramidal abdomen. It repeats, therefore, among the Tricyrtida, that characteristic formation which Sethochytris and Tetrahedrina represent among the Dicyrtida. Some species may be derived from Pterocanium, other species from Podocyrtis, by the development of a lattice-plate closing the terminal mouth. Subgenus 1. Lithochy trades, Haeckel. Three feet of the abdomen solid, not fenestrated, representing external apophyses of the triangular shell-base. 1. Lithochytris cortina, n. sp. (PL 67, fig. 12). Shell three-sided pyramidal, without external strictures, but with two internal girdles. Length of the three joints = 2 : 2 : 5, breadth = 3 : 4 : 6. Cephalis large, truncate-pyramidal, with nine deep divergent ribs (and nine longitudinal rows of pores between them), and with a stout pyramidal horn of half the length. The three prominent edges of the thorax and abdomen are prolonged over the base of the pyramid into three very stout, solid, subovate feet, about as long as the thorax. Dimensions. — Length of the three joints, a 0-04, b OM, c 01 ; breadth, a 0-06, b O'OS, c 012. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Lithochytris pyriformis, n. sp. (PI. 67, fig. 13). Shell pyramidal, nearly pear-shaped, with two distinct strictures. Length of the three joints = 1:1:3, breadth = 1:2:3. Cephalis large, pear-shaped, with a short pyramidal ,horu of half the ^■Lithochytris=.Fot of silex; A/^of, x^i':- REPORT ON THE RADIOLAEIA. 1363 length. Tliorax and abdomen rounded, without prominent edges. Three basal feet pyramidal, solid, nearly vertical, as long as the thorax. Pores irregular, roundish, in the abdomen large, twice to three times as broad as in the t-horax. Dimensions. — Length of the three joints, a 0-03, h 003, c 008 ; breadth, a 0-04, h 0-06, c 009. Rahitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 3. Lithochytris tripodium, Ehreuberg. Lithochytris tripodium, Elirenborg, 1875, AbhandL d. k. Akad. d, Wiss. Berlin, p. 76, Taf. iv. fig. 11. Shell pyramidal, nearly pear-shaped, with two distinct strictures. Length of the three joints = 1:2:4, breadth = 1:2:5. Cephalis with a horn of the same length, conical. Thorax and abdomen rounded, without prominent edges. Three basal feet conical, solid, strongly divergent, shorter than the thorax. Pores subregular, circular, twice as broad in the abdomen as in the thorax. Dimensions. — Length of the three joints, a 002, b 0-04, c 008 ; breadth, a O'Oo, b 0'05, c 01. Habitat. — Fossil in Barbados. •Subgenus 2. Lithochy Iridium, Haeckel. Definition. — Three feet of the abdomen hollow and fenestrated, representing direct protuberances or corner prolongations of the triangular shell-base. 4. Lithochytris galeata, n. sp. (PI. 67, fig. 16). Shell pyramidal, with two sharp strictures. Length of the three joints = 1:1:4, breadth = 1:2:4. Cephalis subspherical, with an oblique pyramidal horn of the same length. Thorax some- what larger. Abdomen inflated, with three sharp, prominent edges, which are prolonged over the shell-base into three pyramidal, hollow, and fenestrated feet, longer than the thorax. Pores subregular, circular, twice as broad in the abdomen as in the thorax. Dimensio'ns. — Length of the three joints, a 0'025, b 0'025, c 01 ; breadth, a 0'025, b 0'05, c 01. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 5. Lithochytris 2iileata, Ehrenberg. Lithochytris pileata, Ehrenberg, 1876, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. v. fig. 3. Shell three-sided pyramidal, with deep collar, but indistinct lumbar stricture. Length of the three joints = 2 : 2 : 9, breadth = 3 : 5 : 10. Cephahs with a conical horn of the same length, pear- shaped. Thorax very short and broad. Abdomen inflated, with three sharp, prominent edges, which 1364 THE VOYAGE OF H.M.S. CHALLENGER. are prolonged over the shell-base into three pyramidal, hollow and fenestrated feet, the lower edge of which is horizontal. Pores regular, circular, of equal size in the thorax and abdomen. Dimensions. — Length of the three joints, a 0-02, h 002, c 0'09 ; breadth, a 0'03, h 0'05, c O'l. Habitat. — FossU in Barbados. 6. Lithochytris lucerna, n. sp. (PI. 67, fig. 14). Shell three-sided pyramidal, with two indistinct strictures. Length of the three joints = 1:2:5, breadth = 2:3:8. Cephalis small, with a horn of the same length, conical. Thorax with sub- spherical cavity. Abdomen with three rounded, prominent edges, which are prolonged over the shell-base into three conical, hollow, and fenestrated feet, twice as long as the thorax, with a thick, pyramidal, terminal spine. Pores subregular, circular, of equal size in the thorax and abdomen. Dimensions. — Length of the three joints, a 0'02, Ij 0'04, c 01 ; breadth, a O'O-l, h 006, c 016. Habitat. — South Pacific, Station 297, depth 17*75 fathoms. 7. Lithochytris lantevna, n. sp. (PL 67, fig. 11). Shell three-sided pyramidal, with two distinct strictures. Length of the three joints = 1:2:4, breadth = l : 3 : 6. Cephalis small, with a pyramidal slender horn of twice the length. Thorax with subspherical cavity. Abdomen with three sharp prominent edges, which are prolonged over the convex shell-base into three slender, prismatic, hollow, fenestrated feet, strongly divergent, twice as long as the thorax (seen in fig. 11 from the vaulted base). Pores circular, twice as broad in the abdomen as in the thorax. Dimensions. — Length of the three joints, a 0'02, h 0'04, c O'OS ; breadth, a 0'02, h 0'06, c 012. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 8. Lithochytris pyramidalis, Ehreuberg. Lithochytris pyramidalis, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. v. fig. 1. Shell three-sided pyramidal, without external strictures, but with two internal transverse girdles. Length of the three joints = 1:2:6, breadth = 2:4:8. Cephalis with a short horn of half the length, conical. Cavity of the thorax subspherical. Abdomen with three rounded edges, prolonged over the concave base into three pyramidal, hollow, and fenestrated feet, twice as long as tlie thorax. Pores large, irregular, roundish. Dimensions. — Length of the three joints, a 0-02, h 0-04, c 012 ; breadth, a 0-04, h 0-08, c 016. Habitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms ; fossil in Barbados. 9. Lithochytris pteropus, n. sp. (PI. 67, fig. 15). Shell three-sided pyramidal, with two indistinct strictures, but with two broad, internal girdles. Length of the three joints = 2:2:6, breadth = 2:3:9. Cephalis with a small horn of half the REPORT ON THE RADIOLARIA. 1365 length, pear-shaped. Thorax broader than long. Abdomen with three prominent, rounded edges, prolonged over the concave base mto three conical, hollow, and fene.strated feet, twice as long as the thorax. Pores small, circular, iiTegular, in longitudinal series along the edge.s. Dimensions. — Length of the three joints, a 0-04, b 0-04, c 0-12 ; breadth, a 0-04, h O'OG, c O'lS. EaUtat. — Central Pacific, Station 268, depth 2900 fathoms. 10. Lithochytris vespertilio, Ehrenberg. Lithochytris vespertilio, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. iv. fig. 10. Shell three-sided pjTamidal, with two indistinct strictures. Length of the three joints =1 : 2 : 5, breadth = 2 : 3 : 10. Cephalis with a short horn of half the length, conical. Thorax inflated. Abdomen without prominent edges, divided in the lower half into three large, conical, hollow, and fenestrated feet, twice as long as the thorax. Pores small, irregular, roundish. Difnensions. — Length of the three joints, a 0-02, h 0-04, c Ol ; breadth, a 004, h O'OC, c 0-2. Habitat. — Fossil in Barbados. Family LXVI. P h o r m o c y r t i d a, n. fam. Theophormida et TheopJicenida, Haeckel, 1881, Prodromus, pp. 436, 437. Definition. — Tricyrtida multii-adiata. (Cyrtoidea with a three-jointed shell, dixdded by two transverse constrictions into cephalis, thorax, and abdomen, with numerous, four to nine or more, radial ajjoi^hyscs. ) The famdy P h o r m o c y r t i d a, composed of the Theophormida and Theophsenida of my Prodromus, comprises those Cyrtoidea in which the lattice-shell is three- jointed, and bears numerous radial appendages (usually six or nine, sometimes more, rarely less, four or five). The two subfamilies difi'er in the shape of the terminal mouth, which is in the Theophormida a simple wide opening, in the Theophsenida closed by a lattice-plate. The phylogenetic origin of the Phormocyrtida may be found either in the Podocyrtida or in the Anthocyrtida ; they may be derived either from the former by interpolation of interradial, secondary apophyses between the three primary perradial apophyses ; or from the latter by development of an abdomen. The radial apophyses are originally radial ribs, which arise from the base of the cephalis on the collar stricture, run along the thorax and abdomen, and are often pro- longed into terminal feet. Whilst in some forms the radial ribs are completely preserved in both joints, they are in other forms only partly visible (in the abdomen), and very often only their free terminal prolongations are preserved in the form of a corona of feet around the mouth of the thorax. This corona is either simple or double. Some- times also a corona is developed on the lumbar stricture, between tlie thorax and abdomen. 1366 THE VOYAGE OF H.M.S. CHALLENGER. These apophyses exhibit a remarkal)le variety in the great subfamily Theophormida, with open mouth. In the small subfamily Theophaenida, however, the apophyses appear as six or nine simple lateral wings on the abdomen. The Theophormida are richly represented not only in the present seas, but also as fossils in Barbados, and numerous remarkable forms have been already described by Ehrenberg, in his genera Calocyclas and Cydadophora. Many Phormocyrtida belong- to the most elegant and admirable forms of Eadiolaria. Synopsis of the Ge7iera of Phormocyrtida. I. Subfamily Theophormida. Terminal mouth of the abdomeQ a simple wide opening. Radial ribs enclosed in the wall of the shell, either the thorax or the abdomen. No radial ribs in the sliell-wall. Peristome with a corona of terminal feet. Radial ribs in the thorax and the abdomen. Radial ribs in the abdomen only. Terminal corona simple. Corona of feet double. Abdomen flat, dilated, with a wide open mouth, Abdomen ovate or cylin- drical, with constricted mouth, . Peristome with free ter- minal feet. Peristome smooth, without free feet, f Abdomen cylindrical or I ovate, not dilated, Abdomen dilated, truncate, conical or disooidal, [ Both coronas terminal. One corona terminal, the other lumbar, II. Subfamily Theophfenida. C Terminal mouth of the ab- ( Six lateral wings, . ■; domen closed by a lattice- < ( plate. ( Nine lateral wings, . 601. Theophormis. 602. Phormocyrtis. 603. Alaeorys. 604. Cydadoj^Jwra. 605. Calocyclas. 606. Clafhrocyclas. 607. Lamproeyclas. 608. Diplocyclas. 609. Hexalatractus. 610. Theophama. Subfamily 1. Theophormida, Haeckel, 1881, Prodromus, p. 436. Defi7iition. — P h o r m o c y r t i d a with the basal mouth of the shell open (vel Tricyrtida multiradiata aperta). Genus 601. Theophormis,^ Haeckel, 1881, Prodromus, p. 436. Definition. — T h e o p h o r m i d a (vel Tricyrtida multiradiata aperta) with numerous radial ribs enclosed in the wall of the thorax and of the flat dilated abdomen ; mouth of the latter wide open. ' Theophormis = T)\\mt bastet ; dto;, hora dodecapleura, u. sp. Shell cupola-shaped, with two deep strictures. Length of the three joints = 2 : 5:6, breadth = 2 : 7 : 10. Cephalis hemispherical, with a conical horn of twice the length. Thorax subspherical, truncate at both poles, thorny, with regular, circular pores. Abdomen in the upper half with a coronal of twelve large ovate holes, separated by twelve divergent, slender ribs, in the lower half with curved, convergent prolongations of the twelve ribs, and niunerous sn>all, irregular, roundish pores. Dimensions. — Length of the three joints, a 0'015, h 0'05, c 0'06 ; breadth, a 0'02, h 0'07, c 0"1. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 11. Ci/dadophora campanula, n. sp. Shell campanulate, with two slight strictures. Length of the three joints = 2:4:5, breadth = 2 : 6 : 10. Cephahs ovate, with a conical horn of the same length. Thorax campanulate, rough, with regular, circular pores. Abdomen dilated, with fifteen to twenty slender, divergent, little curved ribs, which are connected by two or three horizontal rings, and from two or three trans- verse rows of large, roundish, square pores. Dimensions. — Length of the three joints, a 0-04, l 0'08, c O'l ; breadth, a 0'04, h 012, c 0'2. Habitat. — North Atlantic, Bermuda, surface ; also fossil in Barbados. 12. Cycladophora spatiosa, Ehrenberg. Cydadophvra spatiosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. xviii. figs. 5, 6. Shell campanulate, with two shght strictures. Length of the three joints = 2 : 6 : 9, breadths 3 : 8 : 14. Cephahs subspherical, with a conical horn of the same length. Thorax campanulate, 1380 THE VOYAGE OF H.M.S. CHALLENGER. smooth, with regular, circular pores. Abdomen truncate, conical, with sixteen to twenty-four divergent ribs, which are straight or slightly curved, and connected by from four to six transverse, circular rings. The large regular meshes, so produced, form sixteen to twenty-four longitudinal series, and are rounded in the upper, square ia the lower transverse rows. Dimensions. — Length of the three joints, a 002, h 0-06, c 0-09; breadth, a O'Oo, h 0-08, c 014. Habitat. — Fossil in Barbados. 13. Cycladophora favosa, n. sp. (PI. 62, figs. 5, 6). Shell dome-shaped, without collar stricture, but with a deep lumbar stricture. Cephalis flat, cap-shaped, without horn, or with a rudimentary conical horn, with small circidar pores. Length of the three joints = 1:4:3, breadth = 2:5:4. Thorax subspherical, rough, with regular, circular, hexagonally-framed pores. Abdomen truncate, conical, with eighteen to twenty-four prominent ribs ; between every two ribs only two or three ovate pores occur. Mouth circular, with eighteen to twenty-four teeth. The shape of the abdomen is rather variable (figs. 5, 6). Dimensions. — Length of the three joints, a 0-02, h 0-08, e 0-06 ; breadth, a .0-04, h O'OO, c 0-07. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. Subgenus 5. Cyclamptidium, Haeckel. Definition. — Abdomen nearly cylindrical or prismatic, with numerous (ten to twenty or more) straight, vertical, parallel ribs. Moutli wide open, truncate. 14. Cycladophora fenestrata, u. sp. (PI. 68, fig. 2). Shell rough, with two shght strictures. Length of the three joints = 1:5:5, breadth = 1:6:5. Cephalis conical, with a conical, dimpled horn of twice the length. Thorax nearly spherical, with regular, circular pores, and small conical sjiines. Abdomen cylindrical, with eighteen stout, parallel, vertical ribs, which are connected by six to eight horizontal, circular rings ; therefore regular transverse and longitudinal rows of square or circular pores occur. Mouth truncate, circular. Dimensions. — Length of the three joints, a 0-02, b 01, c 01 ; breadth, a 0'03, b 012, c 01. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 15. Cycladophora stiligera, Ehrenberg. Cycladophora stiligera, Ehrenberg, 1875, Abhaudl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. xviii. fig. 3. Shell smooth, with two distinct strictures. Length of the three joints = 2 : 7 : 8, breadth = 2:9:7. Cephalis subspherical, with a conical horn of twice the length. Thorax subspherical, smooth, with regular, ckcular pores. Abdomen cylindrical, with twelve parallel, vertical ribs, which EEPORT ON THE RADIOLARIA. 1381 are connected by three to four broad, horizontal rings ; therefore snbregular, transverse, and longi- tudinal rows of roundish pores are present. Mouth truupate, circular. Dimensions. — Length of the three joints, a 0-02, h 0-07, c 0-08 ; breadth, a 0-02, h OOO, c 0-07. Hahitat. — Fossil in Barbados. Genus 605. Calocyclas,^ Ehreuberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54. Definition. — T h e o p h o r m i d a (vel Tricyrtida multiradiata aperta) with a simple corona of terminal feet around the truncate mouth. Abdomen not dilated, cylindrical or ovate. No ribs in the shell-wall. The genus Galocyclas, and the three following closely allied genera, differ from the four preceding genera of Theophormida in the absence of radial or longitudinal ribs in the wall of the thorax and abdomen. These are completely reduced, and their terminal prolongations only remain, forming a simjale or double corona around the mouth of the abdomen. They correspond therefore to Carpocanium and Anthocyrtis among the Dicyrtida. In Calocyclas the corona is simple. The mouth is not dilated, but often constricted, and the abdomen is cylindrical or ovate, not conical. The teeth of the corona axe usually vertical or convergent. Subgenus 1. Calocy delta, Haeckel. Definition. — Thorax and abdomen smooth, without spines or thorns. 1. Calocyclas veneris, n. sp. (PI. 74, fig. 5). Shell smooth, with two distinct strictures. Length of the three joints =1:2:2, breadth = 1:4:3. CephaHs ovate, with a large, triangular, prismatic horn of three times the length. Thorax hemispherical; abdomen cylindrical; both with regular, circular pores of equal size. Mouth truncate, with a corona of nine to twelve vertical, lamellar feet, which are as long as the abdomen, rectangular, twice as broad as their distance apart, and truncate at the end. Dimensions. — Length of the three joints, a 0'03 to 004, h 0'06 to 01)8, c 0^04 to 0'06 ; breadth, a 0-03 to 0-04, h 0-09 to Oil, c 0-08 to 01. Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific, many stations ; surface, and in various depths. 2. Calocyclas virginis, n. sp. (PL 74, fig. 4). Shell smooth, with distinct collar, but indistinct lumbar stricture. Length of the three joints = 1:2:1, breadth = 1:4:3. Cephalis ovate, with a slender, conical horn, little shorter than the 1 Calocyclas = 'Biia.\itiiul female robe ; x-sAi;, xvK'Ka;. 1382 THE VOYAGE OF H.M.S. CHALLENGEK. shell. Thorax subspherical. Abdomen nearly cylindrical, little contracted towards the peristome. Pores regular, circular, twice as broad in the thorax as in the abdomen, where they are separated by slight longitudinal ribs. Corona of the peristome composed of sixteen to twenty-four vertical, lamellar feet, which are longer than the abdomen, rectangular, and truncate at the end. Dimensions. — Length of the three joints, a 0'04, i O'OS, c 0'05 ; breadth, a O^OS, b O'll, c 0'09. Habitat. — Central Pacific, Station 225, depth 4475 fathoms. 3. Calocyclas minervce, n. sp. Shell smooth, with two deep strictures, similar to Cydadoplwra stiligcra. Length of the three Joints = 1:4:3, breadth = 1:4:3. CephaUs subspherical, with a large, conical horn of three times the length. Thorax subspherical, with small, regular, circular pores. Abdomen cylindrical, with truncate mouth and few irregular pores of different sizes, commonly arranged in three or four subregular, transverse rows, with large intervening distances. Peristome with a corona of twelve to twenty vertical, lamellar feet, which are about as long as the abdomen, and truncate at the end (in Ehrenberg's figure these are broken off). Dimensions.— LQwgth. of the three joints, « 0-02, h 0-08, c 0-06 ; breadth, a 0-02, h 0-09, c 0-07. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 4. Calocyclas aniicce, n. sp. (PL 74, fig. 2). Shell smooth, with two slight strictures. Length of the three joints = 2:4:5, breadth = 2:5:5. Cephalis subspherical, with a pyramidal horn of the same length. Thorax campanulate-conical ; abdomen nearly cylindrical ; both with small, subregular, circular pores. Peristome with a corona of twelve to fifteen small, triangular feet, only as large as the thickness of the shell-wall, and separated by distances of twice the size. Dimensions. — Length of the three joints, a 0'04, h 0'08, c 01 ; breadth, a 0"04, b O'l, c 0"1. Habitat. — North Pacific, Station 253, depth 3125 fathoms. 5. Calocyclas sacerdotis, n. sp. Shell smooth, with two deep strictures. Length of the three joints = 1:3:4, breadth = 1:3:3. Cephalis ovate, with a pyramidal horn of three times the length. Thorax campanulate, conical ; abdomen twice the length, cylindrical ; both with small, regular, circular pores. Peristome somewhat constricted, with a corona of nine to twelve conical feet, which are as long as the cephalis, and with the ends curved inwards, protecting the mouth. Dimensions. — Length of the three joints, a 0-03, b O'OS, c 012 ; breadth, a 0-03, h 0-09, c 0-09. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. 6. Calocyclas vestalis, n. sp. (PL 74, fig. 3). Shell smooth, with two deep strictures. Length of the three joints = 1:2:3, breadth = 1:3:3. Cephalis subspherical, with a pyramidal horn of twice the length. Thorax campanulate ; abdomen REPORT ON THE RADIOLARIA. 1383 nearly cylindrical ; both with reguLir, hexagonal pores, three times as broad as the bars. Peristome constricted, half as broad as the abdomen, with a corona of nine conical, vertical feet as long as the cephalis. DivicTisions. — Length of the three joints, a 0'03, h 0'07, c 01 ; breadth, a 0'035, h Ol, c 01. Hahitat. — Central Pacific, Station 271, depth 2425 fathoms. Subgenus 2. Calocyclissa, Haeckel. Definition. — Thorax spiny or thorny ; abdomen smooth. 7. Calocyclas tiirris, Ehrenberg. Calocydas turris, Ehrenberg, 1875, Abliandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xviii. fig. 7. Shell with two sharp strictures. Length of the three joints =1:4:4, breadth =1:5:4. Cephalis hemispherical, with a stout conical liorn of the same length. Thorax subspherical, thorny with small, regular, circular, quincuncial pores. Abdomen cylindrical, smooth, nearly hyaline, with very scarce, irregular, widely scattered pores. Peristome with a corona of fifteen to twenty broad, lamellar, vertical, truncate feet, about as long as the abdomen. Dimoisions. — Length of the three joints, a 0-02, h 0-08, c 0-08 ; breadth, a 0-03, h 01, c 0-08. Hahitat. — Fossil in Barbados. 8. Calocyclas hyalogaster, n. sp. Shell with two sharp strictures. Length of the three joints =1:4:6, breadth = 1:4:3. Cephalis subspherical, with a conical horn of twice the length. Thorax subspherical, thorny, with regular, circular pores. Abdomen cylindrical, smooth, quite hyaline, without any pores. Peristome with a corona of twelve broad, lamellar, vertical, truncate feet, half as long as the abdomen. Dimensions. — Length of the three joints, a 0-02, b O'OS, c 012; breadth, a 0-02, h 0-08, c 0-06. Hahitat. — South Pacific, Station 300, depth 1375 fathoms. 9. Calocyclas erinaceus, Haeckel. Cydailophora erinaceus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. xviii. fig. 2. Shell with two sharp strictures. Length of the three joints = 2:9:5, breadth = 3:9:5. Cephalis subspherical, rough, with a short and broad conical horn of half the length. Thorax ovate, densely covered with conical spines as long as the horn, and with regular, circular, quincuncial pores. Abdomen cylindrical, smooth, with irregular roundish pores of different sizes. Peristome with twelve to fifteen vertical, broad, lamellar, truncate feet half as long as the abdomen (in Ehrenberg's figui-e these are broken off). Dimensions. — Length of the three joints, a 0-04, h 018, c 01 ; breadth, a 0-06, h 018, c 01. Habitat. — Fossil in Barbados. 1384 THE VOYAGE OF H.M.S. CHALLENGER. 10. Calocyclas gigas, Haeckel. Cydacloplwra gigas, Ehrenberg, 1875, Abliandl. d. k. Aljad. d. Wiss. Berlin, p. 68, Taf. xviii. fig. L Shell with two sharp strictures. Length of the three joints = 2:5:3, breadth = 2:6:4. Cephalis subspherical, rough, with a short and broad conical horn of half the length. Thorax subspherical, campanulate, thorny, with subregular, circular jwres (smaller and more numerous than in the preceding). Abdomen cylindrical, smooth, with a small number of sparsely disposed, roundish, irregularly scattered pores. Peristome with twenty to thirty short, lamellar, truncate, vertical feet about half as long as the cephalis. Bimeiisions. — Length of the three joints, a 0-06, h 015, c 0-09 ; breadth, a 0-06, h 0-18, c 012. Habitat. — Fossil in Barbados. Subgenus 3. Ccdocycloma, Haeckel. Definition. — Thorax smooth ; abdomen spiny or thorny. 11. Calocyclas casta, n. sp. (PL 73, fig. 10). Shell ovate, with two sharp strictures. Length of the three joints = 1:2:8, breadth = 2:4:8. Cephalis hemispherical, with a strong pyramidal horn of twice the length. Thorax campanulate, smooth, with small, regular, circular pores. Abdomen inflated, subspherical, covered with large conical spines, and large intervening circular pores (four times as broad as the thoracic pores). Mouth constricted, only one-third as broad as the abdomen, with a peristome of nine to twelve conical vertical feet as long as the abdominal spines. (In the specimen figured they were broken off.) Dimensions. — Length of the three joints, a 0-03, h 0-04, c 015 ; breadth, a 004, h 0-08, c 015. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 12. Calocyclas pudica, n. sp. Shell ovate, with two distinct strictures. Length of the three joints = 1:3:8, breadth = 1:4:6'. Cephalis subspherical, with a conical horn of three times the length. Thorax and abdomen nearly of the same shape as in the preceding species, but more slender, and the regular, circular pores of the abdomen only twice as broad as the thoracic pores. Conical spines of the abdomen only half as large, but more numerous. Peristome constricted, half as broad as the abdomen, with sixteen to twenty short, conical, vertical feet as long as the cephalis. Dimensions. — Length of the three joints, a 0-02, b 0-06, c 016; breadth, a 0-025, b 0-08, c 012. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. Subgenus 4. Calocycloma, HaeckeL Definition. — Thorax and abdomen spiny or thorny. REPORT ON THE RADIOLARIA. 1385 13. Calocyclas parthenia, n. sp. (PI. 74, fig. 1). Shell nearly ovate, with thorny surface, and two slight strictures. Length of the three joints = 1:2:4, hreadth = 2:4:5. Cephalis hemispherical, armed with numerous short, conical thorns, and with a pyramidal, very large, vertical horn as long as the thorax, and on the basal half as broad as the cephalis. Thorax liemispherical, separated by a slight stricture from the broader, barrel- shaped abdomen, which is a little constricted at the mouth. Teeth of the coronal about twenty, triangular, short, little divergent. Pores circular, somewhat irregular in size, three to four times as broad as the bars, in all three joints nearly of the same shape. Dwicnsions. — Length of the three joints, a 0-03, I 0-06, c O'll ; breadth, a 0-05, h 01, c 012. Habitat. — Indian Ocean, Cocos Islands, surface (Kabbe). 14. Calocyclas aspasia, n. sp. Shell ovate, conical, with two deep strictures. Length of the three joints = 1:3:4, breadth = 1:4:5. Cephalis subspherical, with a conical horn of twice the length. Thorax and abdomen nearly of the same shape as in the preceding species, but covered with longer conical spines, less numerous, and twice as long as the diameter of the subregular, circular pores. Mouth more con- stricted, and armed with a coronal of twelve to sixteen broad, lamellar feet, as long as the cephalis, and similar to those of Calocyclas p^iella (PI. 74, fig. 5). Dimemions. — Length of the three joints, a 0-02, b Q-Q6, c O'OS ; breadth, a 0-03, b 0-08, c 01. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 15. Calocyclas monumentum, n. .sp. (PL 73, fig. 9). Shell nearly conical, with two very deep strictures, everywhere covered with long, bristle-shaped, divergent spines, about as long as the thorax. Length of the three joints =1:2:2, breadth = 1:4:6. Cephalis nearly spherical, with a very large, three-sided pyramidal horn of twice the length. Thorax and abdomen of similar form, campanulate, with a lower cylindrical, and an upper truncate, conical part. Pores irregular, roundish, in the smaller thorax of slightly different sizes, in the larger abdomen three to four transverse rows of larger pores (sLx to eight in each row) are separated by numerous much smaller pores. Peristome wide open, with a coronal of twelve large, triangular, vertical feet, nearly as long as the abdomen ; in the base of each foot a large, roundish, triangular pore. Dimensions. — Length of the three joints, a 0-03, b O'OG, c 0-6 ; breadth, a 0-04, b 012, c 018. HaMtat.—G&ntxal Pacific, Station 271, depth 2425 fathoms. Genus 606. Clathrocyclas,^ Haeckel, 1881, Prodromtis, p. 434. Definition. — Theophormida (vel Tricyrtida multiradiata aperta) -with a simple corona of terminal feet around the dilated mouth. Abdomen dilated, truncate-conical, or discoidal. No ribs in the sheU-w-all, ' (7fc(.«,«7rjoVj x.vx.'ha;. REPORT ON THE RADIOLARIA. 1391 spirally convoluted. Outer coronal of the peristome with twelve to fifteen short, divergent feet, inner with as many convergent, longer feet. Dimensions. — Length of the three joints, « 0-04, i 0-05, c 0-06 ; breadth, a 0-04, b 01, c Olo. Rabitat.—CeiitTal Pacific, Station 272, depth 2600 fathoms. 3. Lamprocyclas dejiorata, u. sp. (PI. 74, fig. 10). SheU ovate, smooth, with deep collar, but indistinct lumbar stricture ; very similar to the two preceding species, but with different horn and peristome. Length of the three joints = 3:5:8, breadth = 3 : 10 : 13. CephaUs subspherieal, with a pyramidal horn of twice the length, the three faces of which are deeply concave. Thoracic pores half as large as the abdominal, both subregular, double-edged. Outer coronal of the wide peristome with nine short, triangular, subvertical feet, inner with nine larger, horizontal feet, lying in the plane of the wide mouth. Dimensions. — Length of the three joints, a O'Oo, I 0-05, c O'OS ; breadth, a 0-03, h 01, c 013. Hahitat. — Central Pacific, Station 265, depth 2900 fathoms. 4. Lamprocyclas saltatricis, n. sp. (PI. 74, fig. Ifi). SheU conical, rough, with two slight strictures. Length of the three joints = 2:2:3, breadth = 1:4:6. Cephalis ovate, with a large, prismatic horn, half as long as the shell. Pores subregular, circular, not double-edged, three times as broad in the inflated abdomen as in the hemispherical thorax. Outer coronal of the wide peristome with twelve to fifteen divergent feet, inner with fifteen to twenty conical feet, which are curved inwards nearly horizontally. Dimensions. — Length of the three joints, a 0-04, b O'Oo, c 0-07 ; breadth, a 0-025, b 01, c 015. EaUtat. — North Pacific, Station 244, depth 2900 fathoms. 5. Lamprocyclas regince, n. sp. (PL 74, figs. 11, 12). SheU campanulate, with two slight strictures. Length of the three joints = 2:3:3, breadth = 2:5:6. CephaUs subcylindrical, with about fifteen longitudinal rows of circular pores, separated by prominent, paraUel crests, and with a very large sword-like horn, nearly as long as the shell. Thorax hemispherical, smooth, with elegant, circular, hexagonaUy-framed pores. Abdomen dilated, with similar but larger pores, armed with hook-shaped spines. The two inferior rows of these hooks form the double coronal of the peristome ; the feet of the outer are curved downwards, of the inner inwards. Dimensions. — Length of the three joints, a 0-04, b 0-06, c 0-06 ; breadth, a 0-04, b 01, c 012. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 6. Lamprocyclas cegles, Haeckel. Podocyrtis cegles, Ehrenberg, 1854, Mikrogeol., Taf. xxxv. B. B iv. fig. 18. SheU campanulate, conical, thorny, with two deep strictures. Length of the three joints = 3:5:5, breadth = 3 : 8 : 11. Cephalis ovate, with a stout, three-sided prismatic horn of twice the 1392 THE VOYAGE OF H.M.S. CHALLENGER. length. Pores subregular, circular, twice as broad in the inflated abdomen as in the campanulate thorax, and four times as broad as in the cephalis. Outer coronal of the wide peristome with fifteen to twenty conical, divergent feet, inner coronal with a smaller number of vertical, parallel, divergent feet. Dimoisioiis. — Length of the three joints, a O'OS, h 0-05, c 0-05; breadth, a 0-03, h O'OS, c Oil. Habitat. — North Atlantic, depth 1400 fathoms (Berrymaun). Subgenus 2. Lam^jrocycloma, Haeckel. Definition. — Feet of the peristome forked or branched. 7. Lamprocyclas hajaderce, n. sp. Shell campanulate, very similar to the preceding species, but with stronger spines on the abdomen and with different peristome. Length of the three joints = 2:2:3, breadth = 2:6:8. Cephalis equal to that of Lamprocydas maritalis (PI. 74, figs. 13, 14). Outer coronal of the peristome with fifteen to twenty divergent, pyramidal feet, half as long as the horn ; inner coronal with as many longer, vertical feet, which are irregularly forked or branched. BimensioTis. — Length of the three joints, a 0'04, h 0-04, c 0-06 ; breadth, a 0-04, h 012, c 016. Habitat. — South Pacific, Station 298, depth 2225 fathoms. Genus 608. Diplocyclas,^ Haeckel, 1881, Prodromus, p. 434. Definition. — T hcophormida (vel Tricyrtida multiradiata aperta) with a double corona of radial solid feet, an upper around the lumbar stricture, a lower around the mouth. No ribs in the shell- wall. The genus Diplocyclas differs from all the other Theophormida in the possession of a double coronal of radial teeth, an upper between thorax and abdomen, and a low^er around the terminal mouth of the latter ; it may be regarded as an Anthocyrtis, which has formed an abdomen, and repeated the terminal armature. The cephalis bears a single or double apical horn. 1. Diplocyclas bicorona, n. sp. (PL 59, fig. 8). Shell slender, campanulate. Length of the tliree jouits = 1:3:2, breadth = 1:4:4. CephaHs subspherical, with two divergent horns ; the occipital of the same length and forked, the frontal shorter and simple. Thorax campanulate, with six to eight transverse rows of double-edged roundish pores of increasing size. Abdomen cylindrical, with three transverse rows of large poly- ' Diplocyclas = Female robe with a double girdle ; aiizhoos, xvithis. REPORT ON THE RADIOLARIA. 1393 gonal pores, and a terminal row of very small square pores. Lumbar and terminal coronals of similar shape, each with twenty to thirty short divergent feet. Bimi-yisions.— Length of the three joints, a 0-02, 6 0-06, c 0-04; breadth, a 0-025, b O'OS, c 0-08. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 2. Diplocyclas bicincta, u. sp. Shell campanulate, in general of the same form as, and similar fenestration to, the preceding species but not so slender, and with different proportions. Length of the three joints = 1:4:2, breadth = 2:5:5. Cephalis hemispherical, with a single, conical, simple horn. Pores of the thorax hexa- gonal, of increasing size (in eight to ten transverse rows). Abdomen with smaller square pores (in four to six rows). The two coronals of the same shape as in PL 59, fig. 8. Dimensions.— Length of the three joints, a 0-02, b 008, c 0-04 ; breadth, a 004, b 01, c 01. Habitat. — North Pacific, Station 253, depth 3125 fathoms. 3. Diclocyclas bizonalis, n. sp. Shell subconical, with iudistuict coUar and distinct lumbar stricture. Length of the three joints =1:2:3, breadth = 1:3:4. Cephalis hemispherical, with two divergent conical horns of equal size. Thorax conical, with small, irregular, roundish, double-edged pores, and a terminal corona of about nine very large pores. Abdomen truncate, conical, with three to four transverse rows of roundish, quadrangular, very large pores. Lumbar and terminal coronals of similar shape, each with twelve to fifteen triangular divergent feet. Dimensions. — Length of the three joints, a 0-02, b 0-04, c 0-06 ; breadth, a 0-02, b O'OG, c 0-08. Habitat. — South Pacific, Station 295, depth 1500 fathoms. Subfamily 2. Theoph^nida, Haeckel, 1881, Prodromus, p. 437. Definition. — Pli or m o cy rt ida with the basal mouth of the shell fenestrated (vel Tricyrtida multiradiata clausa). Genus 609. Hexalatractus} n. gen. Definition. — T h e o p h se n i d a (vel Tricyrtida multiradiata clausa) with six lateral wings on the abdomen. The genus Hexalatractus, and the following genus Tlieoiohcena, represent together the small subfamily Theophsenida, or those Tricyrtida in which the terminal mouth of the shell is closed by lattice-work, and six or nine lateral apophyses indicate a multi- radiate structui-e. The shell is more or less ovate or spindle-shaped, tapering towards ' H'exatorac(its = Spindle with six wings ; ej«>i«, a!T{«xToc. (ZOOL. CHALL. EXP. PAET XL. — 1886.) Kl 175 1394 THE VOYAGE OF H.M.S. CHALLENGEE. both poles, and resembles greatly the triradiate Rhojxdocaiiium. It may be derived from the latter by interpolation of three secondary or interradial wings between the three primary or perradial apophyses. 1. Hexalatractus sexalatus, n. sp. Shell ovate, smooth, with two distinct strictures. Length of the three joints = 3:6:9, breadth = 4:9:8. Cephalis subspherical, with a pyramidal horn of twice the length. Thorax campanu- late ; abdomen inversely conical ; both with subregular, circular pores. Six divergent wings arise, beginning from the collar stricture, from the upper half of the shell, with broad triangular base ; they are little curved downwards, with the convexity outside, and gradually tapering towards the distal end ; the latter lies in the same horizontal plane as the basal apex of the abdomen. Dimensions. — Length of the three joints, a O'OS, h 0-06, c 009 ; breadth, a 0-04, h 0-09, c 0'08. Habitat. — ^Central Pacific, Stations 263, depth 2650 fathoms. 2. Hexalatractus fusiformis, n. sp. (PI. 68, fig. 13). Shell rough, nearly spindle-shaped, with sharp collar and slight lumbar stricture. Length of the three joints = 2:5:12, breadth = 3:8:7. Cephalis hemispherical, with a conical horn of the same length. Thorax hemispherical, with regular, circular, hexagonally-framed pores. Abdomen inversely conical, with irregular, roundish pores. From the upper half of the abdomen arise, with broad triangular base, six divergent wings, which are nearly straight, and slightly fenestrated at the base ; their conical distal ends do not reach the horizontal plane, in which the basal apex of the abdomen lies. Dimensions. — Length of the three joints, a 0-02, h 0-05, c 0-12 ; breadth, a 0-03, h 0-08, c 0-07. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. Genus 610. TJieophcena,'^ Haeckel, 1881, Prodromus, p. 437. Definition. — Theophsenida (vel Tricyrtida multiradiata clausa) with nine lateral wings on the abdomen. The genus TheojihcBna differs from the preceding six-radiate Hexalatractus in the possession of nine lateral wings, and may be derived from the triradiate Bhopalocanium by interpolation of six secondary wings between the three primary apophyses. 1. TJieophcena corona, n. sp. (PI. 70, fig. 12). Shell rough, nearly spindle-shaped, with two sharp strictures. Length of the three joints = 4: 9:16, breadth = 5 : 12 : 10. Cephahs hemispherical, very thick-walled, with a conical horn of ' r/icop^Bwa = Divine shell ; k6;, (fxii/x. REPORT ON THE RADIOLARIA. 1395 the same length; both covered with numerous small dimples and spinules. Thorax campanulate • abdomen inversely conical ; both with regular, circular pores. Thorax with nine thin curved ribs, which in the upper half of the abdomen arise as nine large feet, which are strongly compressed and curved (with the convexity outwards) ; their distal ends form nine ovate spinulate cones, and lie in the same horizontal plane as the basal apex of the abdomen. Dimensions. — Length of the three joints, a 0'04, b 0'09, c O'lG ; breadth, « 0-05, b 012, c 01, Habitat. — Indian Ocean, Madagascar (Ealjbe), surface. 2. TJieopliaina nonaria, n. sp. Shell thorny, ovate, with two slight strictures. Length of the three joints =1:4:5, breadth = 1:5:4. Cephalis subspherical, with a conical horn of half the length. Thorax subspherical, with regular, circular pores and conical spines. Abdomen ovate, smooth, with irregular, roundish pores. In the upper half of the thorax descend nine straight, little divergent ribs, which in the lower half become free, and represent nine slender, conical wings ; their distal ends do not reach the horizontal plane in which the basal end of the abdomen lies. Dimensions. — Length of the three joints, a O'OS, b 012, c 015; breadth, a 0'03, b 014, c 012. Habitat. — South of Australia, Station 160, surface. Family LXVII. Theocyrtida, n. fam. Theocorida et Theocapsida, Haeckel, 1881, Prodromus, pp. 434, 436. Definition. — T ricyrtida eradiata. Cyrtoidea with a three -jointed shell, divided by two transverse constrictions into cephaUs, thorax, and abdomen, without radial apophj^ses. The famUy Theocyrtida, composed of the Theocorida and Theocapsida of my Prodromus, comprises those Cyrtoidea in which the lattice-shell is three-jointed, and bears no external radial apophyses. The two subfamilies differ in the shape of the terminal mouth, which in the Theocorida is a simple wide opening, in the Theocapsida closed by a lattice-plate. The phylogenetic origin of the Theocyrtida may be found either in the Podocyrtida or in the Sethocyrtida ; they may have been derived from the former by reduction and loss of the three primary apophyses, or from the latter by development of an abdomen. The number of species in this group is very large, and many belong to the most common and widely distributed Cyrtoidea. A great number of living and fossil species have already been described by Ehrenberg, the majority being disposed in his genera Lithocampe and Eucyrtidium. The number of genera, however, is comparatively small, and their distinction difficult, since the form of the shell presents no striking differences. 1396 THE VOYAGE OF H.M.S. CHALLENGER. It exhibits all possible passages, from a flatly expanded or nearly discoidal form with a wide open mouth, to a conical or cylindrical, and by constriction of the terminal mouth to an ovate or spindle-shaped form. By complete closure of the mouth the Theo- capsida arise. In some genera remarkable traces of the original triradial structure are preserved. The most interesting of these forms is Axocorys, with an internal axial columella, which bears a number of verticils, each with three radial branches. Synopsis of the Genera of Theocyrtida. L Subfamily Theocorida. Terminal mouth of the abdomen a simple wide open- II. Subfamily Theocapsida. Terminal mouth closed by a lat- tice-plate. Abdomen gra- dually dilated towards the wide open mouth. Abdomen cylindrical, of nearly equal breadth throughout its whole length. Mouth trun- cate. Abdomen flatly ex- panded, dis- coidal. With horn, No horn, 611. 612. Theoralyptra. Ceeryphalium Abdomen One horn, 613. Theoconus. conical. Two or more horns, . 614. Lopkoconus. single apical ' Thorax and abdomen of equal breadth, 615. Theocyrtis. horn on the \ cephalis. I Thorax much broader than [ the tubular abdomen, . Two horns or a bunch of horns on the cephalis, ...... No horn on the cephalis, .... Abdomen ovate or in- versely conical. Mouth more or less con- stricted. A single apical horn on the - cephalis. Shell-cavity without an in- ternal columella, . Shell-cavity witli an axial columella, Two horns or a bunch of horns on the cephalis, ...... No horn on the cephalis. An apical horn, No horn on the cephalis, A complete latticed septum between thorax and abdomen, No latticed septum between thorax and abdomen. 616. Theosyringium. 617. Lopliocyrtis. 618. Tricolucampe. 619. Theocorys. 620. Axocorys. 621. Lopliocorys. 622. Tlieocampe. 623. Theocapsa. 624. Tricolocapsa. 625. Phrenocodon. Subfamily 1. Theocorida, Haeckel, 1881, Prodromus, p. 434. Definition. — T heocyrtida with the basal mouth of the shell open (vel Tricyrtida eradiata aperta). REPORT ON THE RADIOLARIA. 1397 Genus 611. Tlieocalyptra,^ Haeckel, 1881, Prodromus, p. 434. Definition. — Theocorida (vel Tricyrtida eradiata aperta) with diseoidal or flatly expanded abdomen. Cephalis with a single apical horn, or with two divergent horns. The genus TJieocalyptra, and the follouang closely allied genus Cecnjphalium, differ from all the other Theocorida in the flattened form of the cap-shaped or nearly diseoidal shell. The abdomen specially is quite flat, often horizontally expanded, and like the mai'ginal brim of a flat hat. They may be derived from the Dicyrtida Setho- cephaliis by the development of an abdomen, or from Corocalyptra by loss of the collar wings. The network is usually very delicate, as in the latter. The cephalis of Theocalyptra bears one or two horns. 1. Theocalyptra veneris, n. sp. Shell flatly campanulate, very delicate and fragile, very similar to Eucephryphalus agtiesce (PI. 59, fig. 3), but without collar spines. Length of the three joints = 1 : 4 : 2, breadth = 1 : 7 : 9. Cephalis hemispherical, with a single bristle-shaped horn of twice the length. Thorax sub- conical, separated from the flatter abdomen by a deep stricture, with thin bars, and large, subregular, hexagonal meshes, increasing in size towards the smooth mouth-edge. Dimensions. — Length of the three joints, a 0'02, I 0"07, c 004 ; breadth, a 0-025, b 0'15, c O'L Habitat. — Cosmopolitan ; Atlantic, Indian Pacific, many stations, surface. 2. TJieocalyptra orci, Haeckel. Halkaliiptra orci, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 293, Taf. x. figs. 9, 10. Shell flatly campanulate, very similar to the preceding species in general form and fenestration, but flatter and smaller, with different proportions. Length of the three joints = 7 : 2 : 1, breadth = 1:6:8. Cephalis hemispherical, very small, with two divergent, bristle-shaped horns of the same length. Abdomen nearly horizontally expanded. Dimensions. — Length of the three joints, a 0-015, b 0-04, c O'Ol ; breadth, a 0-02, b 012, c 0-16. Habitat. — Indian Ocean, Zanzibar, depth 2200 fathoms (PuUen). 3. TJieocalyptra discoides, Haeckel. Cydadoplwra discoides, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. xviii. fig. 4. SheU flatly campanulate, similar to the two preceding species, but not so delicate, with thicker bars, and roundish, not hexagonaL meshes. Length of the three joints =1:2:2, breadth = 3:6:9. 1 Theocalyptra = 'Dvrm(^ veil; li6i, xa^v^rrj*. 1398 THE VOYAGE OF H.M.S. CHALLENGER. Cephalis large, trilobed, with a short, oblique horn of half the length. Thorax campanulate, conical, separated from the abdomen by a circle of smaller pores and a deep stricture. Abdomen flat, dis- coidal, with three circles of larger pores. Dimensions. — Length of the three joints, a 0-02, b 0-04, c OM ; breadth, a 0-06, h 012, c 018. Habitat. — Fossil in Barbados. 4. Theocalyi^tra cornuta, Haeckel. Carpocanium cornutum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. ii. fig. 9. Hdlicalyptra cornuta, Bailey, 1856, Amer. Journ. Sci. and Arts, vol. xxii. p. 5, pi. i. figs. 13, 14. Lophophmna cornuta, Haeckel, 1862, Monogr. d. Radiol., p. 299. Shell campanulate-conical, with two sharp strictures. Length of the three joints = 1:3:1, breadth = 1:4:5. Cephalis subspherical, with two stout, pyramidal, divergent horns of twice the length. Thorax campanulate, with eight to ten transverse rows of roundish or nearly square pores, increasing in size towards the abdomen, which is flatly expanded, nearly discoidal, separated by a circle of smaller pores ; the last circle of pores (on the margin) is larger. Di'mensio7is. — Length of the three joints, a 0'025, b 0'09, c O^OS ; breadth, a 0'03, b 012, c 016. Habitat. — Arctic Ocean, Kamtschatka (Bailey), Greenland (Ehrenberg). Genus 612. Cecryphalium,^ Haeckel, 1881, Prodromus, p. 434. Definition. — Theocorida (vel Tricyrtida eradiata aperta) with discoidal or flatly expanded abdomen. Cephalis without horn. The genus Cecry2)halium has the same flat, conical, or nearly discoidal shell as the preceding Tlieoccdyptra, its ancestral genus, but difl^ers from it in the complete absence of horns on the cephalis. 1. Cecryphalium lamprodiscus, n. sp. (PI. 58, fig. 2). Shell flatly conical, with two slight strictures. Length of the three joints = 1:3:2, breadth = 1 : 7 : 11. Cephalis roundish, very small. Thorax conical, with straight lateral outline ; its pores irregular, polygonal, increasing in size towards the girdle. Abdomen Kttle flatter than the thorax, forming its direct prolongation, with five to six circular, concentric rows of pores ; the first row formed by sixty to eighty very large, oblongish, quadrangular pores, the second row by very small, the third again by larger pores ; the outmost rows by very small and numerous pores. Dimensions. — Length of the three joints, a 0-02, b 0-06, c 0-04 ; breadth, a 0-02, b 014, c 0-22. Habitat. — Central Pacific, Station 272, surface. 1 Cecryphalium = Net-cap ; xexjwpaXio*. EEPORT ON THE RADIOLARIA, 1899 2. Cecryphalium sestrodiscus, u. sp. (PI. 58, fig. 1). Shell very flat, subcorneal, nearly discoidal, with two distinct strictures. Length of the three joints = 1:2:1, breadth = 1 : 8 : 10. Cephalis kidney-shaped, very small. Thorax flat, campanu- late, with curved lateral outline ; its pores irregular, polygonal, increasing in size towards the girdle. Abdomen horizontally expanded, hke the brim of a hat, with five to six concentric, circular rows of pores, the pores of the inner rows twice to three times as large as those of the outer rows. (The inner circle of large, oblongish, quadrangular pores, characteristic of the preceding species, is here divided into three concentric rings by two circular hoops.) Dimensions. — Length of the three joints, a 0-02, h 0-04, c 0-02; breadth, a 0-02, h 0-15, c 0-2. HaMtat. — Central Pacific, Station 274, surface. Genus 613. Theoconus,^ n. gen. Definition. — T h e o c o r i d a (vel Tricyrtida eradiata aperta) with conical abdomen, gradually dilated towards the wide open mouth. Cephalis with a single horn. The genus TJieoconus, and the following closely allied Lophoconus, differ from the other Theocorida in the conical or campanulate form of the shell ; the abdomen is a truncated cone, gradually dilated towards the terminal mouth. The latter is usually truncated, widely open, sometimes with a slightly constricted peristome. The cephalis of Theoconus bears a single apical horn. Subgenus 1. Tlieocorax, Haeckel. Definition. — Pores of the thorax and of the abdomen of nearly equal size and simdar form. 1. Theoconus zancleus, Haeckel. Eucyrtidiyni zandeum, J. Miiller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 41, Taf. vi. figs. 1-3. Eucyrtidium zandeum, Haeckel, 1862, Monogr. d. EadioL, p. 321. Shell bell-shaped, nearly conical, smooth. Length of the three joints = 1:3:4, breadth = 1 : 4 : 6. Cephalis nearly spherical, with a stout, straight, pyramidal horn of the same length. Thorax hemi- spherical. Abdomen gradually increasing in breadth towards the wide truncated mouth. Pores in all three joints nearly of the same shape, circular, regular, four times as broad as the thin bars. Dimensions. — Length of the three joints, a 0-027, h O'OS, c 01 ; breadth, a 0'03, b 0'12, c 018. Habitat. — Mediterranean (Messina, Naples, Nice, &c.). ' Theoconus = Divine cone ; $i6s, xcJuo;. 1400 THE VOYAGE OF H.M.S. CHALLENGER. 2. TJieoconus CBgcBus, Haeckel. Eucyrtidium cegcaum, Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 31 ; Mikrogeol., 1854, Taf. xxxv. a, xix. a, fig. 5. Eucyrtidium cegceum, Haeckel, 1862, Monogr. d. Eadiol., p. 329. Shell flatly bell-shaped, nearly conical. Length of the three joints = 2:5:3; breadth =1:7:8. CephaUs ovate, with a stout, straight, pyramidal horn of the same length. Thorax flat, bell-shaped. Abdomen with increasing breadth towards the wide truncated mouth. Pores in all three joints nearly of the same shape, regular, circular, three times as broad as the bars. Divicnsions. — Length of the three joints, a 0'02, b 0'05, c O^OS ; breadth, a 0'016, b 0'07, c 0*08. Habitat. — Mediterranean (Coast of Greece and Sicily), surface. 3. Tlieocomis zanguebaricus, Haeckel. Eucyrtidium zangueharicum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 293, Taf. ix. fig. 22. Shell bell-shaped. Length of the three joints = 1:2:1, breadth = 1:3:4. Cephalis ovate, with a straight, pyramidal horn of half the length. Thorax hemispherical, without collar stricture, but with evident girdle stricture. Abdomen dilated towards the wide truncated mouth. Pores regular, hexagonal, of nearly equal size and form, four to six times as broad as the thin Ijars. Dimensions. — Length of the three joints, a 003, b 0-06, c 0-03 ; breadth, a 0-024, b 0-09, c Oil. Habitat. — -Indian Ocean (off Zanzibar), PuUen, depth 2200 fathonLS. 4. Tlieoconus campanulatiis, Haeckel. ? Eucyrtidium campanulatum, Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 241. Eucyrtidium camj^anulatum, Haeckel, 1862, Monogr. d. Eadiol., p. 329. Shell beH-shaped, smooth. Length of the three joints = 2:3:7, breadth = 3 : 7 : 10. Cephalis small, spherical, with a short, conical, oblique horn of the same length. Thorax hemispherical, with an external girdle stricture, prolonged into the truncated, barrel-shaped abdomen, which is a little constricted at the very wide mouth. Pores small and very numerous, regular, circular, twice to three times as broad as the bars. Dimensions. — Length of the three joints, a 0'02, b 0'03, c 0'07 ; breadth, a O'Oo, b 0'07, c 01. Habitat — North Atlantic, Station 352, surface. 5. Tlieoconus orthoconus, n. sp. Shell perfectly conical, smooth. Length of the three joints = 1:2:3, breadth = 1:2:4. Cephalis hemispherical, with a strong, straight, conical horn of the same length. Thorax conical, without external girdle stricture, prolonged into the truncated, conical abdomen, which is gradually REPORT ON THE RADIOLARIA. 1401 dilated into a very wide mouth. Pores small, of nearly equal size and similar form, of the same breadtli as the bars. DimcnsioTis. — Length of the three joints, a O'OS, b O'OG, c 0-09 ; breadth, a 0-03, b 0-06, c 0-12. Habitat. — Cosmopolitan ; Atlantic, Pacific ; many stations, at different depths. Subgenus 2. Theocorhis, Haeckel. Definition. — Pores of the thorax and of the abdomen of different sizes or dissimilar forms. 6. Theoconus jovis, n. sp. (PL 69, fig. 4). Shell bell-shaped, nearly conical. Length of the three joints = 5 : 6 : 7, breadth = 4 : 10 : 14. Cephalis nearly cylindrical, large, little curved, with a very large, oblique, pyramidal horn, as long as the two first joints together. Thorax and the broader abdomen irregularly bell-shaped, dilated towards the wide mouth. Pores circular, somewhat irregularly disposed, gradually increasing in size towards the mouth. Dinunsions. — Length of the three joints, a 0'05, b 0'06, c 0'07 ; breadth, a 0'04, h Ol, c 014. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 7. TJieocomis jimonis, n. sp. (PI. 69, fig. 7). Shell nearly conical. Length of the three joints = 4 : 5 : 8, breadth = 3 : 8 : 11. Cephalis ovate, with a large apical opening at the base of the vertical compressed horn, which has about the same length. Thorax and the broader abdomen together conical, gradually dilated towards the wide mouth. Thorax with a bosom-Hke protuberance on one side. Pores circular, gradually increasing in size. Dimensions. — Length of the three joints, a 0-04, I 0-05, c O'OS ; breadth, a 0-03, b 0-08, c Oil. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 8. Theoconus longicornis, n. sp. Shell conical, thorny. Length of the three joints = 1:2:4, breadth =1:3:6. Cephalis nearly spherical, with a very large, cylindrical, perpendicular, straight horn, once and a half to twice as long as the whole shell. Thorax conical. Abdomen nearly hemispherical, with wide open mouth. Pores circular, four to six times as broad in the thick-walled spiny abdomen as in the thin-walled rough thorax. Dimensions. — Length of the three joints, a 0-03, h 0-06, c 0'12 ; breadth, a 0-03, b 0'09, c 0-18. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms ; also fossil in Barbados. (ZOOL. CHALL. EXP. PART XL. — 1886.) Er 176 1402 THE VOYAGE OF H.M.S. CHALLENGER. 9. TJieoconus ampuUaceus, Haeckel. Lithocampe ampullacea, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. iv. fig. 1. TTieocorys ampullacea, Haeckel, 1881, Prodromus, p. 434. Shell bell-shaped, nearly conical, thorny. Length of the three joints = 3 :4 : 10 ; breadth = 4:8:15. Cephalis siibspherical, with a stout lateral horn of the same length. Thorax hemi- spherical, rough. Abdomen siibspherical, widely truncated at both poles, spiny. Pores regulai', circular, three to four times as broad in the thick-walled abdomen as in the thin-walled thorax. (Differs from the similar preceding species in the smaller liom and the two deeper strictures of the shell.) Dimensions. — Length of the three joints, a O'Oo, b 0'04, c O'l ; breadth, a 0'04, b 0'08, c 015. Habitat. — Fossil in Barbados. 10. Theoconus -amjilus , Haeckel. 1 Podocyrtis ampla, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xvi. fig. 7. 'i Podoci/rtis ampki, Biitschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 539, Taf. xxxiii. fig. 16. 1 Eucyrtidium amplum, Ehrenberg, 1873, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 248. Shell conical, smooth, with two broad internal annular septa. Length of the three joints = 1:3:4, breadth =1:4:5. Cephalis subspherical, with a very large, straight, conical horn of the same breadth, which is as long as the conical thorax. Pores regular, circular, twice as broad in the truncate, gradually dilated abdomen as in the thorax. Dimaisions. — Length of the three joints, a 0-03, b 0-09, c 012; breadth, a 0-03, b 012, c 015. Habitat. — Fossil in Barbados. 11. Theoconus ariadnes, n. sp. Shell conical, nearly bell-shaped, smooth. Length of the three joints = 1 : 2 : 3, breadth = 1:3: 5. Cephalis subspherical, with a conical spine of about the same length. Thorax hemispherical, thin- walled. Abdomen conical, slightly constricted at the wide open mouth. Pores regular, circular, twice as large in the thick-walled aMomen as in the thin-walled thorax. Diiimisions. — Length of the three joints, a O'OIS to 0-022, b 0-03 to 0-035, c 0-06 to 0-07; breadth, a 0-015 to 0-02, b 0-04 to 0-06, c 0-07 to O'OO. Habitat. — Cosmopolitan ; Atlantic, Indian, and Pacific Oceans, common, surface. 12. Tlieoconus dionysins, Haeckel. Tliyrsocyrtis dionysia, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xii. fig. 5. Tliyrsocyrtis jaccMa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xii. fig. 7. Shell bell-shaped, smooth. Length of the three joints = 1:3:5, breadth = 1:4:5. Cephalis subspherical, with a conical, irregularly denticulate horn of twice or thrice the length. Thorax REPORT ON THE RADIOLARIA. 1403 inflated, nearly spherical, truncate at both poles, separated by a deep stricture from the ceplialis, as well as from the conical abdomen, which is dilated gradually towards the wide mouth. Pores in the thorax subregular, circular, in the abdomen twice to four times larger, and irregular. Dimensions. — Length of the three joints, a 0'02,, 6 0'06, c O'l ; breadth, a 0'02, h 0'08, c 01. Habitat. — Fossil in Barbados. 13. Tlieoconus laterna, u. sp. Shell conical, smooth. Length of the three joints = 1:2:4, breadth = 1:2:4. Cephalis small, ovate, with a strong, pyramidal, vertical horn three times the length. Thorax hemispherical, with subregular, circular, hexagonally-framed pores. Abdomen truncate, conical, with only fifteen to twenty very large, irregular, polygonal pores, which are separated by very thick bars of the same breadth as the horn. Dimensions. — Length of the three joints, a 0"03, b O'OG, c 012 ; breadth, a 0'03, b 0'07, c 012. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 14. Theoconus Jicus, Haeckel. Eucyrtidinm ficiis, Ehrenberg, 1875, Abhandl. d. k, Akad. d. Wiss. Berlin, p. 70, Taf. xi. fig. 19. ■ Theocorys fictis, Haeckel, 1881, Prodromus, p. 434. Shell conical, pear-shaped, smooth. Length of the three joints = 1 : 5 : 20, breadth = 2 : 10:25. Cephalis very small, ovate, with a conical, straight horn three times the length. Thorax quite conical, with solid wall, without pores. Abdomen very large, nearly spherical, truncate at both poles, little constricted at the very wide mouth ; its pores subregular, circular, about three times as broad as the bars. (This species is intermediate between the genera Theoconus and Theocorys.) Dimensiom. — Length of the three joints, a O'Ol, b 0-05, c 0'2 ; breadth, a 0'02, b 01, c 0'25. Habitai. — Fossil in Barbados. Genus 614. Lophoeonus} n. gen. Definition. — T heocorida (vel Tricyrtida eradiata aperta) with conical abdomen oradually dUated towards the wide open mouth. Cephalis with two or more horns or a corona of horns. The genus Lophoconus has the same conical shell with truncate mouth as Theoconvs, and differs from it only in the armature of the cephalis, bearing either two large diver- gent horns (usually a larger occipital and a smaller frontal horn), or a bunch or corona of numerous divergent horns. 1 iop/iocowMs = Cone with a crest ; Xo'^oj, xuvo;. 1404 THE VOYAGE OF H.M.S. CHALLENGER. 1. Lophoconus antilope, Haeckel. Eucyrtidium antilope, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. ix. fig. 18. Shell conical, smooth, with two slight strictures. Length of the three joints = 1:3:8, breadth = 2:4:8. Cephalis hemispherical, with two divergent, pyramidal horns of twice the length. Thorax campanulate. Abdomen gradually dilated towards the wide open mouth. Pores very small and numerous, regular, hexagonal. Dimcnsio7is. — Length of the three joints, a 0-015, h O'OS, c 0-12 ; breadth, a 0-025, h 0-07, c 0-12. Habitat. — Indian Ocean ; between Aden and Socotra (Haeckel) ; Zanzibar (Pulleu). 2. Lophoconus hexagonalis, n. sp. Shell campanulate, conical, s-piny, with two sharp strictures. Leng-th of the three joints = 1 : 2:4, breadth = 1:3:6. CephaHs hemispherical, with numerous conical spines of different sizes, the largest of twice the length. Thorax campanulate, with smaller spines. Abdomen inflated, dUated towards the wide moi;th. Pores large, three or four times as broad as the bars, subregular, hexagonal. Dimendons. — Length of the three joints, a 0-02, h 0-05, c 0-09 ; breadth, a 0-03, h 0-07, c 0-12. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 3. Lophocomis cornutella, n. sp. Shell slender, conical, smooth, without external strictures, but with two internal, annular septa. Length of the three joints = 1 : 2 : 6, breadth = 1:2:4. Cephalis ovate, with two stout, divergent, conical horns of tlixee times the length. Thorax and abdomen together conical, gradually dilated towards the wide truncate mouth. Pores regular, circular, quincuncial. Z»Mftc?isto?is.— Length of the three joints, a O'OS, h 0-06, c 0-12 ; breadth, « 0-02, h 0-04, c 0-08. Habitat. — North Atlantic, Station. 353, depth 2965 fathoms. 4. Lophoconus apiculatus, Haeckel. Eucyrtidium apicidatum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. "Wiss. Berlin, p. 70, Taf. X. fig. 10. Shell campanulate, conical, thorny, with two distinct strictures. Length of the three joints = 1:2:2, breadth =1:3:4. Cephalis subspherical, with a bunch of eight to twelve divergent, conical horns, the largest of which are longer than the cephalis. The regular, circular pores are in tlie campanulate thorax scarcely half as broad as in the truncate, gradually dilated abdomen. Dimensions. — Length of the three joints, a 0-02, b 0-04, c 0-04 ; breadth, a 0-025, b 0-06, c 0-08. Habiiat. — Fossil in Barbados. REPORT ON THE RADIOLARIA. 1405 5. Lophoconus cervics, Haeckel. ? Eucyrtidium cervus, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. ix. fig. 21. Shell conical, smooth, without external stricture, but with two internal annular septa. Length of the three joints = 1:2:4, breadth = 1:3:6. Cephalis campanulate, with two to six divergent, partly ramified horns. Pores in tlie thorax regular, circular, in tlie abdomen three to four times as larse, regular, hexagonal. Dimensions. — Length of the three joints, a, 0-02, h 0-04, c 0-08 ; breadth, a 0-02, h 0-06, c 0-12. Habitat. — Indian Ocean, Cocos Islands (Eabbe), surface (? Zanzibar, 2200 fathoms, PuUen). 6. Lophoconus rhinoceros, n. sp. (PL 69, fig. 2). Shell campanulate, conical, rough, with two sharp strictures. Length of the three joints = 1:2:3, breadth = 1:3:4. Cephalis subspherical, with numerous very small pores, and two stout, divergent, pyramidal horns, the major of which is longer, the minor shorter, than the cephalis. Thorax campanulate, with small, regular, cii-cular pores. Abdomen inflated, with thickened margin at the wide open mouth, and with irregular, roundish pores, twice to four times as broad as those of the thorax. Dimensions. — Length of the three joints, a 0'03, h 0'05, c 0'09 ; breadth, a 0'04, l 0'09, c 012. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. Genus 615. Theocyrtis,^ n. gen. Definition. — Theocorida (vel Tricyi-tida eradiata aperta) with cylindrical abdomen, and wide oj)en truncate mouth. Cephalis with a single horn. The genus Theocyrtis and the three following closely allied genera difi"er from the other Theocorida in the cylindrical form of the slender abdomen, which is of equal breadth nearly throughout its whole length. The terminal mouth is wide open, usually truncate, and of the same breadth ; sometimes slightly constricted. The cephalis of Theocyrtis bears a single horn. Subgenus 1. Tlieocorypha, Haeckel. Definition. — Pores of the thorax and abdomen of nearly equal size and similar form. 1. Tlieocyrtis trachelius, Haeckel. Eucyrtidium trachelius, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 293, Taf. vii. fig. 8. Shell thin-walled and very fragile, smooth. Length of the three joints = 2 : 8 : 7, breadth = 2:9:8. Cephalis subspherical, with a straight, conical horn of the same length, separated by a 1 71ieocyrtis='DiYme basket ; ho;, xvorig. 1406 THE VOYAGE OF H.M.S. CHALLENGER. slender neck from the inflated, siibspherical thorax. Abdomen cylindrical, with a wide open, truncate mouth. Pores subregular, hexagonal, of equal size, four to six times as broad as the thin, thread-like bars. Dimemions. — Length of the three joints, a 0-02, h 0-08, c 0-07 ; breadth, a 0-02, h 009, c 0-08. Habitat. — Tropical Pacific, many Stations (200, 224, 271, &c.), surface, and in various depths. 2. Theocyrtis harhadensis, HaeckeL Eueyrtidiwn harhadense, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. ix. fig. 7. Shell thin-walled, smooth. Length of the three joints = 2:4:5, breadth, 2:5:4. Cephalis ovate or conical, with a strong, conical horn, without external stricture, dilated into the campanulate thorax. Abdomen cylindrical, with a wide open, truncate mouth. Pores subregular, circular, quincuncially disposed, of about the same breadth as the bars. Dimensions. — Length of the three joints, a 0'04, h O'OS, c 01 ; breadth, a 0'04, h 01, c 0'08. Habitat. — Fossil in the Tertiary rocks of Barbados. 3. Theocyrtis cylindrica, HaeckeL Eucyrtidium cylindricum, Ehrenberg, 1875, AbhandL d. k. Akad. d. Wiss. Berlin, p. 70, Taf. X. fig. 1. Shell elongate, cylindrica], straight, smooth. Length of the three joints = l :2 : 6, breadth = 1:3:3. Cephalis hemispherical, with a thick, pyramidal horn of the same length (the edges of the horn giving to it the appearance of being composed of two converging spines). Thorax truncated, conical. Abdomen perfectly cylindrical, much elongated. Pores subregular, circular, twice as broad as the bars, quincuncially disposed. Mouth wide open, truncate. Dimensions.— 'Length of the three joints, a 0-02, h 0-04, c 012 ; breadth, a 0-03, h O'OO, c 0-06. ^aftito^.— Tropical Pacific, Station 2G6, depth 2750 fathoms ; fossil in Barbados. 4. TJieocyrtis elegans, HaeckeL Eucyrtidium elegans, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xi. fig. 12. ? Eucyrtidium pusilluin, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 72, Taf. xi. fig. 6. Shell slender, cylindrical, straight, smooth. Length of the three joints =1:2:7, breadth = 1:3:3. Cephalis subconical, with a small conical horn. Thorax campanulate, conical. Abdomen cylindrical, very slender. Pores subregular, circular, small, disposed in transverse rows, three in the thorax, six to eight in the abdomen. Mouth wide open, truncate. Dimensions. — Length of the three joints, a O'Ol, h 0-02, c 0-07 ; breadth, a 0-015, b O'OS, c 0-03. Habitat. — Fossil in Barbados and Sicily. REPORT ON THE RADIOLARIA. 1407 5. Tlieocyrtis paupera, Haeckel. Euctjrtidium pauperu7n, Ehrenberg, 1875, Abhandl. d. k. AkaJ. d. "Wiss. Berlin, p. 72, Tiif. xi. fig. 13. Shell slender, cylindrical, smooth. Length of the three joints = 1 : 2 : G, breadth = 1:3:3. Cephalis hemispherical, with a stout conical horn of twice the length. Thorax truncate, conical' Abdomen cylindrical. Pores very small, regular, circular, disposed in transverse rows, one or two in the thorax, three to five in the abdomen. (Distance between the rows twice as great as in the preceding nearly related species.) Mouth wide open, truncate. Dimensions. — Length of the three joints, a O'Ol, b 0'02, c 0'06 ; breadth, a 0'015, h 0-03, c 0-03. Habitat. — "Western Tropical Pacific, Station 225, depth 4475 fathoms ; also fossil in Barbados and Sicily. 6. Theocyrtis microtheca, Haeckel. Eueyrtidium viicrotheca, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berhn, p. 72, Taf. xi. fig. 10. Eueyrtidium hillabi/, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 72, Taf. xi. fig. 8. Shell cylindr'ical, a little rough. Length of the three joints = 1:3:4, breadth = 1:3:3. Cephalis subspherical, with a small conical horn. Thorax hemispherical or campanulate. Abdomen cylindrical, with wide open truncate mouth. Pores subregular, circular, quincuncially disposed, of medium size, rudimentary or wanting in the cephalis. Dimensions. — Length of the three joints, a 0-015 to 0-02, b 0-03 to 0-05, c 0-05 to 008 ; breadth, a 0-02 to 0-025, b 0-05 to 0-06, c 0-05 to 0-06. Habitat. — Central Pacific, Stations 263 to 274, depth 2350 to 2925 fathoms; also fossil in Barbados. Subgenus 2. Theocorusca, Haeckel. Definition. — Pores of the thorax and the abdomen of different sizes or forms. 7. Theocyrtis macroceros, n. sp. (PL 69, fig. 13). Shell almost cylindrical, smooth. Length of the three joints =1:2:5, breadth = 2:3:4. Cephalis hemispherical, with a very large cylindrical horn, once or twice as long as the shell. Thorax truncate, hemispherical. Aljdomen cylindrical, only slightly contracted towards both ends. Two girdle strictures deep. Pores small, subregular, circular, more irregular and twice to three times as large in the abdomen as in the thorax, disposed in transverse rows, five to six in the thorax, eight to ten in the abdomen. Dimensions. — Length of the three joints, a 0-02 to 0-03, b 0-04 to 0-05, c 0-1 to 0-12 ; breadth, a, 0-04, b 0-07, c 0-08. Habitat. — South Atlantic, Station 335, depth 1425 fathoms ; also fossil in Barbados. 1408 THE VOYAGE OF H.M.S. CHALLENGER. 8. Theocyrtis ptychodes, n. sp. (PL 69, fig. 8). Shell almost cylindrical, smooth. Length of the three joints = 1:3:3, breadth ^2:4:4. Cephalis hemispherical, with a large, conical, curved horn of twice the length. Thorax very large, inflated, campanulate, thick- walled. Abdomen cylindrical, with a thin folded wall (like a petticoat), the thickness of which decreases gradually towards the wide truncate mouth. Pores subregular, circular, and quincuncially disposed in the two first joints, irregular and larger in the abdomen, forming lonEritudinal series between the folds. Dimensions. — Length of the three joints, a 0-04, h 01, c Oil ; breadth, a O'Oo, h 012, c 012. Hahiiat. — Central Pacific, Station 272, depth 2600 fathoms. 9. Theocyrtis aspera, HaeckeL Eucyrtidium asperum, Ehrenberg, 1875, Abbandl. d. k. Akad. d. "Wiss. Berlin, p. 70, Taf. viii. fig. 15. Shell almost cylindrical, with rough or thorny surface. Length of the three joints = 1:3:5, breadth = 1:5:5. Cephalis subspherical, small, with a short conical horn. Thorax hemispherical, inflated. Abdomen cylindrical, with wide truncate mouth. Pores in the thorax subregular, circular, quincuncially disposed, in the abdomen irregular roundi.sh, two to four times as large. Dimensions. — Length of the three joints, a 0-015 to 0-02, b 0-06 to 0-07, c O'OS to 01 ; breadth, a 0-02, h 01, c 01. Habitat. — Tropical Atlantic, Station 338, depth 1990 fathoms^ fossil in Barbados. 10. TJieocyrtis proserpineB, n. sp. Shell almost cylindrical, smooth. Length of the three joints = 3:6:9, breadth = 2:8:7. Cephalis subspherical, with a stout conical horn. Thorax campanulate. Abdomen cylindrical. Pores regular, circular, quincuncially disposed, double-edged in the thorax, and three to four times as large as in the cephalis and the abdomen. Bimemions. — Length of the three joints, a 0-03, b 0-06, c 0-09 ; breadth, a 0-02, b O'OS, c 0-07. Habitat. — North Pacific, Stations 244 to 253, depth 2050 to 3125 fathoms. 11. TJieocyrtis oenophila, HaeckeL Thyrsocyriis oenophila, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xii. fig. 8. Shell in the apical half conical, in the lower cylindrical. Length of the three joints = 2:5:6, breadth = 3:8:7. Cephalis subspherical, with a large prismatic horn, which is bulbous at the base, and armed with three teeth at the distal apex. Thorax conical, constricted at tlie base, with subregular, ciixular, quincuncial pores. Abdomen cylindrical, with a coronal of nine large REPORT ON THE RADIOLARIA. 1409 roundish pores beyond the hnnbar stricture, and two to four succeeding transverse rows of irregular, roundish, smaller pores. Mouth widely open, truncated. Dimfusiom. — Length of the three joints, a 0-02, h 0-05, c O'OG ; breadth, a OOo, h 0-08, c 0-07. Habitat. — Fossil in Barbados. Genus 616. TJieosyringium, Haeckel/ 1881, Prodromus, p. 434. Definition. — T li e o c o r i d a (vel Tricyrtida eradiata aperta) with cylindrical abdomen, which is much narrower than the inflated thorax, and forms a slender, narrow tube, with truncated mouth. Cephalis with a single horn. The genus Tlieosi/ ring i urn differs from the closely allied Theocyrtis, its ancestral form, in the wide inflated thorax, which is much broader than the narrow tubular abdomen. The mouth of the latter is small and truncate. 1. Tlieosyringium tibia, n. sp. (PI. 68, fig. 4). SheU rough, very slender, with two distinct strictures. Length of the three joints = 1:3:4, breadth = 1:2:1. Cephalis ovate, with a conical horn of the same length. Thorax ellipsoidal. Abdomen cylindrical, as long as the two former joints together. Pores subregular, circular. mmensions. — Length of the tliree joints, a 0-0.3, h 0-09, c 012 ; breadth, a 0-03, 1 0-06, c 0-02. Hahitat. — Central Pacific, Station 263, depth 2650 fathoms. 2. Tlieosyringium pij^etta n. sp. (PI. 68, fig. 5). SheU rough, inflated, with two sharp strictures. Length of the three joints = 2 : 7:9, breadth = 2:7:2. Cephalis conical, with a slender horn of half the length. Thorax subglobose. Abdomen cylindrical, as long as the two former joints together. Pores subregular, circular. Dimensions. — Length of the three joints, a 0-02, h 0-07, c 0-09 ; breadth, a 0-02, I 0-07, c 0-02. Hahitat. — Central Pacific, Station 268, depth 2900 fathoms. 3. Tlieosyringium siphonium, n. sp. Shell rough, inflated, with two deep strictures. Length of the three joints = 1:3:3, breadth = 1:2:1. Cephalis subspherical, with a stout pyramidal horn of twice the length. Thorax broad ovate. Abdomen slender, inversely conical, as long as the thorax, and one-third as broad as the base. Pores subregular, circular, hexagonaUy framed. (Similar to Eusyringium conosiphon, PI. 78, fig. 10) but only with two strictures and three joints.) Diriunsions. — Length of the three joints, a 0-03, h 01, c 01 ; breadth, a 0-03, h 0-07, c 0'025. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. ' rAeosi/nj!5fMtTO=Divine tube; 6iig, avoiyyiov. (ZOOL. CHALL. EXP. — PART XL. — 1886.) Rr 177 1410 THE VOYAGE OF H.M.S. CHALLENGER. 4. TJieosyringium tuhiilus, Haeckel. Eucyrtidium tuhulus, Ehrenberg, 1875, Abhaudl. d. k. Akad. d. Wiss. Bei'lin, p. 72, Taf. xi. fig. 6. Shell smooth, slenderly spindle-shaped, with two slight strictures. Length of the three joints =: 2:10:8, breadth = 3 : 6 : 3. Cephalis hemispherical, hyaline, with a stout, pyramidal horn of the same length. Thorax spindle-shaped. Abdomen inversely conical, half as long as the thorax prolonged into a slender, cylindrical tube. Pores subregular, circular. Dimensions.— Length, of the three joints, a 0-02, h 01, c 0-08 ; breadth, a 0-03, h 0-06, c 0-03. Habitat. — Fossil in Barbados. Genus 617. Lophocyrtis} n. gen. Definition. — T heocorida (vel Tricyrtida eradiata aperta) with cylindrical abdomen, and wide open truncate mouth. Cephalis with two horns, or a bunch of horns. The genus Lophocyrtis differs from its ancestral form Theocyrtis only in the armature of the cephalis, bearing instead of a single horn either two divergent horns, or a bunch, or coronal of numerous spines. The slender abdomen is in both genera cylindrical, with wide open mouth. 1. Lophocyrtis holothuria, n. sp. Shell smooth, slender, with two distinct strictures. Length of the three joints = 1:2:4, breadth = 2:4: 3. Cephalis hemispherical, with a bunch of five divergent, conical horns, the middle of which is larger and vertical, nearly as long as the thorax. Thorax campanulate, half as long as the cylindrical abdomen. Mouth truncate. Pores regular, chcular, quiucuucial. (Similar to Theocyrtis cylindrica, but with different cephalis aud thorax.) DimensioTis. — Length of the three joints, a 0-03, h 0-05, c 01 ; breadth, a 0-04, b 0-07, c O'OO. Habitat. — Central Pacific, Station 268, depth 2900 fathom.s. 2. Lophocyrtis stephanophora, Haeckel. Eucyrtidium stephanophorum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 72, Taf. viiL fig. 14. Shell smooth, slender, with deep collar and indistinct lumbar stricture. Length of the three joints = l :2 :4, breadth = 1 : 3 : 3. Cephalis subspherical, with very smaU circular pores, and a corona of three to nine short conical spines. Thorax campanulate, with regular, circular pores, which are half or one-third as broad as those of the cylindrical alxlomen. Dimensions. — Length of the three joints, a 0-025, b 005, v 009 ; breadth, a 0-025, b O'OG, c 0-06. Habitat. — Fossil in Barbados. 1 Lophocyrtis = 'Basket with a crest ; Xeipof, xt/jxi's. REPORT ON THE RADIOLARIA. 1411 3. Loplwcyrtis synapta, n. sp. Shell spiny, with two sharp strictures. Length of the three joints = 5 : 10 : 6, breadths 4:9:7. Cephalis large, ovate, with ninnerous (twenty to thirty or more) conical, radially divergent spines of different sizes, the largest about as long as the cephalis. Thorax subconical, with numerous short, conical, divergent spines, which are directed downwards. Abdomen smooth, cylindrical. The irregular, polygonal pores are separated by thin bars, and in the thorax are twice to four times as broad as in the first and last joints. Dimcmwm. — Length of the three joints, a 0-05, h 01, c O'CG ; breadth, a 0-04, h O'OO, c 0-07. Habitat. — Indian Ocean, Maldive Islands (Haeckel), surface. 4. Lophocyrtis coronata, HaeckeL Eucyrtidium coronatum, Ehrenberg, 1875, Abhandl. J. k. Akad. d. Wiss. Berlin, p. 70, Taf. X. fig. 9. Shell smooth, cylindrical, with two deep strictures. Length of the three joints = 4:3:4, breadth = 4:5:4. Cephalis subspherical, large, of about the same size and form as the thorax, with a coronal of four to eight short, conical spines on the apex. Pores in the two first joints irregular, roundish, twice to four times as broad as the small, circular pores of the cylindrical abdomen, which are disposed in four to eight transverse rows. Dimensions. — Length of the three joints, a 0^04, h G'03, c 0-04 ; breadth, a 0'04, I 0-05, c 0'04. Habitat. — Central Pacific, Station 273, depth 2350 fathoms ; fossU in Barbados. 5. Lophocyrtis biaurita, Haeckel. Uucyrtidium hiauritum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. X. fig. 8. Eucyrtidium hiauritum, Biitschli, 1882, Zeitschr. f. wis.s. Zool., p. 540, Taf, xxxiii. fig. 38, «-/. Shell smooth, with two distinct strictures. Length of the three joints = 1:6:3, breadth = 2:5:4. Cephalis small, hemispherical, hyaline, with two large, divergent, cun^ed horns of three times the length. Thorax ovate, with few small, widely scattered pores. Abdomen cylindrical, without pores. Dimensimis. — Length of the three joints, a O'Olo, b 0'06, c 0'03 ; breadth, a 0'02, b 0'05, c 0-04. Habitat. — Fossil in Barbados. Genus 618. Tricolocampe,^ Haeckel, 1881, Prodromus, p. 434. Dejinition. — Theocorida (vel Tricyrtida eradiata aperta), with cylindrical abdomen, and wide open truncate mouth. Cephalis without horn. The genus Tricolocampe differs from its ancestral genus, Theocyrtis, in the loss of the cephalic horn ; it has the same cylindrical form of the slender abdomen, and ■ a wide ' Tricolocampe = Caterpillar -with three joints ; tjiV, xu'Koij, xuftTrti. 1412 THE VOyAGE OF H.M.S. CHALLENGER. open terminal moutli of the same breadth. The whole shell is more or less cylindrical, (sometimes conical in the upper part), with two distinct external strictures, or internal annular septa. Subgenus 1. Tricolocampium, Haeckel. Definition. — Pores of the thorax and of the abdomen of nearly equal size and similar form. 1. Tricolocampe cylindrica, n. sp. (PI. QQ, fig. 21). Shell nearly cylindrica], smooth. Length of the three joints = 2:3:15, breadth = 3:4:5. CephaHs hemispherical, with numerous very small pores. Thorax and abdomen cyhudrical, of about equal breadth, with equal, circular pores, disposed regularly in transverse rows, three to four rows in the thorax, ten to twelve in the abdomen. Mouth wide open, not constricted. Dimensions. — Length of the three joints, a 0-02, h 0-03, c 0-15 ; breadth, a 0-03, h 0-04, c 0-05. Habitat. — Central Pacific, Stations 265 to 274, depth 2350 to 2925 fathoms. 2. Tricolocampe pupa, Haeckel. Eucyrtidium pupa, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 293, Taf. vii. fig. 16. SheU nearly cylindrical, smooth. Length of the three joints=2 : 2 : 8, breadth = 2 : 3 : 3. Cephalis subsj)herical, with four larger pores. Thorax and abdomen cylindrical, of about equal breadth, with equal, very small pores, disposed regularly in transverse rows, two rows in the thorax, eight to ten in the abdomen. Mouth wide open, a little constricted. Dimensions. — Length of the three joints, a 0-02, b 0-02, c 0-08 ; breadth, a 0-02, b 0-03, c Om. Habitat. — Tropical Pacific (Philippine Sea), Station 20G, depth 2100 fathoms. 3. Tricolocampe polyzona, n. sp. (PI. QQ, fig. 19). Shell nearly cylindrical, thick-walled. Length of the three joints = 4:4:12, breadth = 8:9:9. Cephalis obtuse, conical. Thorax barrel-shaped. Abdomen in the middle part a httle constricted. Pores very numerous, subregular, disposed regularly in transverse rows, six to eight in the cephaUs, eight to ten in the thorax, twelve to fifteen in the abdomen. Mouth rather constricted, only half as broad* as the abdomen. Dimensions. — Length of the three joints, a 0-04, b 0-04, c 012 ; breadth, a 0-08, b O'OO, c 0-09. Habitat. — Central Pacific, Stations 266 to 272, depth 2425 to 2925 fathoms; also fossil in the Nicobars and in Barbados. REPORT ON THE RADIOLARIA. 1413 4. Trtcolocampe stenozona, u. sp. (PL QQ, fig. 20). Shell nearly cylindrical, tliin-walled. Length of the tliree joints = 5 : 4 : 9, breadth = 6 : 8 : 9. Form of the three joints and disposition of their pores nearly equal to the preceding species ; Ijut the proportion of the joints is different, the shell more delicate, and the mouth more widely open, and nearly as broad as the abdomen. Dimenswns. — Length of the three joints, a 0-05, b 0-04, c 0-09 ; breadth, a 0-OG, b O'OS, c 0-09. Habitat. — North Pacific, Station 256, depth 2950 fathoms. 5. Tricolocam2Je amphizona, n. sp. (PL QQ, fig. 17). Shell mitre-.shaped, very thick- walled. Length of the three joiuts = 2 : 1 : 1, breadth nearly uniform. Cephalis obtuse, conical, as long as the two other cylindrical joints together (probably composed of several united joints). Pores subregular, disposed in transverse rows, six to eight in the cephalis, two in the thorax, and two in the abdomen. Mouth widely open. Dimensions. — Length of the three joints, a 0-04, b 0'02, c 0'02 ; breadth, a 0'04, b 0'05, c 0'05. Hahitai. — Tropical Atlantic, Station 348, depth 2450 fathoms. 6. Tricolocampe panthera, Haeckel. Eucyrtidium panth&ra, Ehrenberg, 1875, Abhandl. d. k. Aknd. d. Wiss. Berlin, p. 72, Taf. xi. fig. 18. Shell mitre-shaped or nearly cylindrical, thick-walled. Length of the three joints = 1:2:3, breadth = 1 : 2 : 2. Cephalis subspherical. Thorax campanulate. Abdomen cylindrical. Pores in all three joints irregular, roundish, of different sizes, irregularly disposed. Mouth widely open, truncated, not constricted. Dimensions. — Length of the three joints, a 0-015 to 0-02, b 0-04 to 0-05, c 0-06 to 0-08 ; breadth about ff. 0-02, b and c 0-05. Habitat. — Cosmopolitan ; Atlantic, Pacific ; also fossil in Barbados. Subgenus 2. Tn'coZocampfra, Haeckel. Definition. — Pores of the thorax and the abdomen of different sizes or forms. 7. Tricolocampe urnula, n. sp. (PL QQ, fig. 22). Shell cylindrical, v.ith obtuse conical apex, smooth. Length of the three joints = 2:3:10, breadth = 2:3:6. Cephalis subsi^herical. Thorax barrel- shaped. Abdomen cylindrical with slightly con- stricted wide mouth. Pores irregular, roundish, three to four times as broad in the abdomen as in the thorax, irregularly disposed. Dimensions. — Length of the three joints, a 0-02, b 0-03, c O'l ; breadth, a 0-025, b 0-035, c 0-06. Habitat. — Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms. 1414 THE VOYAGE OF H.M.S. CHALLENGER. 8. Tricolocampe doliolum, n. sp. Shell cylindrical, with hemispherical apex, rough. Length of the three joints =1:3:5, breadth = 1:2:3. Cephalis spherical. Thorax and abdomen cylindrical, of nearly equal breadth. Mouth ■widely open, not constricted. Pores irregular, roundish, in the abdomen three to four times as large as in the thorax, disposed in oblique rows. Dimensions. — Length of the three joints, a 0-03, b OW, c 0-16 ; breadth, a 0-03, i 0-05, c OW. Habitat. — Fossil in Barbados. 9. Tricolocampe cingulata, n. sp. Shell subcylindrical, with obtuse conical apex, thick-walled. Length of the three joints = 2 : 3 : 11, breadth = 3:7:8. Cephalis hemispherical, not separated externally from the short conical thorax, but with internal collar septum. Abdomen cylindrical, with wide open, non-constricted mouth. Pores in the thorax narrow, obliquely ascending, in the abdomen twice as large, circular, arranged in ten to twelve regular transverse rows, separated by slight strictures. Lumbar septum nearly complete. Dimensions. — Length of the three joints, a 0^02, b Q-m, p 01 to 012; breadth, «0-03, 6 0-07, c 0-08. Habitat. — -Fossil in Barbados, and in Tertiary rocks of Sicily ; living in the depths of the Atlantic and Central Pacific, Station 348, depth 2450 fathoms ; Station 268, depth 2900 fathoms. 10. Tricolocampe arcta, Haeckel. ? Eucyrtidium ardnin, Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 33. ? Ldthocamjje arcta, Haeckel, 1862, Monogr. d. Radiol., p. 317. Shell subcylindrical, with obtuse conical apex. Length of the three joints =1:2:4, breadth = 1:2:2. Cephalis subspherical. Thorax campanulate, separated by a deep collar, but a slight lumbar stricture. Abdomen cylindrical, with wide truncate mouth. I'ores in the thorax narrow, obliquely ascending, in the abdomen half as large, very small, and densely disposed in six to eight regular transverse rows. Dimensions. — Length of the three joints, a 0-022, b 0-045, e 0-09 ; breadth, a 0-026, b 0-05, c 0-05. Habitat. — Central Pacific, Station 266 to 274, depth 2350 to 2925 fathoms. Genus 619. Theocorys} Haeckel, 1881, Prodromus, p. 434. Definition. — T li e o c o r i d a (vel Tricyrtida eradiata aperta) with ovate abdomen, broader than the constricted mouth. Cephalis with a single horn. The genus Tlieocorys and the two following closely allied genera, united formerly with Eucyrtidium, differ from the preceding Theocorida in the constriction of the ' r/ieocor!/s = Divine helmet ; Stii, koqu;. REPORT ON THE RADIOLARIA. 1415 peristome, so that the inflated abdomen is broader than the terminal mouth. They represent, therefore, the transition to the Theocapsida, with closed mouth. The abdomen is commonly more or less ovate or barrel-shaped, sometimes inversely conical. The cephalis of Theocorys bears a single apical horn, Subgenus 1. Theocoronium, Haeckel. Definition. — Pores of the thorax and of the abdomen of nearly equal size and similar form. 1. Theocorys turgidula, Haeckel. Euciirtidium turgidulum, Ehrenberg, 1872, Abhaudl. d. k. Akad. d. Wiss. Berlin, p. 293, Taf. vii. fig. 13. Shell slender, ovate, with two deep strictures, very fragile and thin-walled. Length of the three joints = 2:5:7, breadth = 2:6:6. Cephalis subspherical, with a pyramidal horn of the same length. Thorax nearly spherical. Abdomen ovate, twice as broad as the constricted mouth. Pores very numerous, regular hexagonal, three to four times as broad as the bars. Dimensions. — Length of the three joints, a 0'015, h 0'005, c 0'07 ; breadth, « 0'02, h 0"06, c 006. Habitat. — Tropical Pacific (Philippine Sea), Stations 206 and 224, surface. 2. Theocorys veneris, n. sp. (PL 69, fig. 5). Shell uiversely ovate, with two deep strictures, smooth. Length of the three joints = 2:5:6, breadth = 3:7:6. Cephalis hemispherical, with a slender conical horn of twice the length. Thorax nearly spherical. Abdomen ovate, twice as broad as the constricted mouth. Pores regular, circular, twice as broad as the bars, quincuncially disposed. Dimensions. — Length of the three joints, a 0-02, h 0-05, c 0-06 ; breadth, a O'OS, h 0-07, c 0-06. Habitat. — -Cosmopolitan ; Atlantic, Indian, Pacific ; many Stations, surface. 3. Tlieocorys cretica, Haeckel. Eucyrtidmm creticum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. xi. fig. 23. Shell ovate, thin-walled, smooth, with two deep strictures. Length of the three joints = 2:4:4, breadth = 3:6:6. Cephahs hemispherical, with a conical horn of the same length. Thorax and abdomen nearly hemispherical, inflated, united by the opposite bases of the hemispheres. Constricted mouth only one-third as broad as the abdomen. Pores very small and numerous, regular, circular, of the same breadth as the bars, quincuncially disposed. Dimensions. — Length of the three joints, a 0-2, b 0-04, c 0-04 ; breadth, a 0-03, h 0-06, c 0-06. Habitat. — Mediterranean, Crete, Corfu, surface. 1416 THE VOYAGE OF H.M.S. CHALLENGEE. 4. Theocorys ovata, n. sp. (PL 69, fig. 16). Shell quite ovate, thick-walled, smooth, without external strictures. Length of the three joints = 2:2:9, hreadth = 3:5:7. Cephalis conical, with a thick conical horn of the same length. Thorax and ahdomen gradually dilated towards the base, and then hemispherical, constricted. Mouth scarcely one-third as broad as the abdomen, prolonged into a short tube. Pores regular, circular, disposed in transverse rows, two to three in the cephalis, two to three in the thorax, eight to ten in the abdomen. Dimensions. — Length of the three joints, a 0-02, b 0-02, c 0-09 ; breadth, a 0-03, b 0-05, c 0-07. Habitat. — Central Pacific, Stations 263 to 268, depth 2650 to 3000 fathoms. 5. Theocorys plutonis, n. sp. (PL 69, fig. 1). Shell ovate, thick-walled, smooth, with two slight strictures. Length of the three joints = 2 : 5 : 4, breadth=4 : 7: 6. Cephalis hemispherical, with a conical, oblique horn of the same length. Thorax and abdomen only slightly inflated, gradually decreasing towards the wide, httle constricted mouth. Pores subregular, circular, much larger in the abdomen and the lower half of the thorax than in the upper half and the cephalis. Dimensions. — Length of the three joints, « 0-02, b 0-05, c 0-04 ; breadth, a 0-04, b 0'07, c 0-06. Habitat. — South Pacific, Station 295, depth 1500 fathoms. 6. Theocorys scolopax, HaeckeL Euciirtidium scolopax, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 72, Taf. ix. fig. 5. Shell slender, inversely ovate, smooth. Length of the three joints = 1:3:3, bi-eadth = 1 : 4 : 4. Cephalis subspherical, with a long, slightly curved horn, half as long as the whole shell. Thorax campanulate. Abdomen inversely ovate, twice as broad as the constricted mouth (incomplete in Ehrenberg's figure). Dimensions. — Length of the three joints, a 0-02, b 0'06, c 0'06 ; breadth, a 0'02, b O'OS, c 0-08. Habitat.— ¥o?,&i\ in Barbados. Subgenus 2. Theocoryihium, HaeckeL Definition.- — Pores of the thorax and of the aLdomeu of difi"erent sizes or dissimilar forms. 7. Theocorys diance, n. sp. (PL 69, fig. U). Shell almost ovate, with two deep strictures. Length of the three joints = 3:6:8, breadth = 3:9:8. Cephalis subspherical, with a slender, pyramidal horn of three times the length. Thorax REPORT ON THE RADIOLARIA. 1417 conical, constricted at the base. Abdomen bottle-shaped. Pores in the thora.x irregular, polygonal, in the alxlomen subregular, circular, qnincuucially disposed. Dimensions. — Length of the three joints, a 0-03, h O'OG, c 0-08 ; breadth, a 0-03, b O'OQ, c 0-08. Mabitat. — North Pacific, Station 253, surface. 8. Theoc(yrys hyaloihorax, n. sp. Shell slender, ovate, with two deep strictures. Length of the three joints = 6:9:8, breadth = 7:12:11. Cephalis subspherical, with numerous densely-placed circular pores, and with a pyramidal, slender horn of the same length. Thorax hemispherical, hyaline, without any pores. Abdomen ovate, twice as broad as the constricted mouth, with two to four widely distant, transverse rows of small, circular pores. Divicnsions. — Length of the three joints, a 0-024, h 0-036, c 0-032 ; breadth, a 0-028, b 0-048, c 0-044. Habitat. — Tropical Pacific, Station 225, depth 4475 fathoms. 9. Theocorys bachahunda, Haeckel. Thyrsoeyrtis bachabunda, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84 Taf. xii. fig. 4. Shell inversely ovate, with two distinct strictures. Length of the three joints = 2 : 5 : 9, breadth = 3:9:8. Cephalis subspherical, small, with a large cylindrical horn, which is half as long as the whole shell, and armed with spines at the conical apex. Thorax conical, inflated, with small, subregular, circular, quincuneial pores. Abdomen inversely ovate, with irregular, roundish, pores of larger and smaller sizes mixed, gradually lessening towards the constricted mouth. Dimensions.- — Length of the three joints, a 0-02, b 0-05, c 0-09 ; breadth, a 0*03, b 0-09, c 0-08. Habitat. — Fossil in Barbados. 10. Theocorys attenuata, Haeckel. EucyHidium aftenuatum, Ehrenberg, 1875, Abhaudl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xi. fig. 16. vShell inversely ovate, with distinct collar, but indistinct lumbar stricture. Length of the three joints = 2:5:5, breadth = 2:7:6. Cephalis hemispherical, with a short, oblique, conical horn. Thorax inflated, campanulate, with small, regular, circular, quincuneial pores. Abdomen inversely conical, with irregular pores of larger and smaller sizes mixed, gradually lessening towards the truncated mouth. Dimensions. — Length of the three joints, a 0-02, b 0-05, c 0-05 ; a 0-025, b 0-07, c 0-06. Habitat. — Central Pacific, Station 268, depth 2900 fathoms ; also fossil in Barbados. 11. Theocorys ohliqua, n. sp. (PI. 69, fig. 10). Shell inversely ovate, with distinct collar, but indistinct lumbar stricture. Length of the three joints = 3 : 7 : 4, breadth = 4 : 9 : 8. Cephalis hemispherical, with a stout, pyramidal, oblique (ZOOL. CDALL. EXP. — PART XL. — 1886.) Er 178 1418 THE VOYAGE OF H.M.S. CHALLENGER. horn of the same length. Thorax and abdomen together ovate, gradually lessening towards the constricted mouth, which is only half as broad. Pores irregular, roundish, in the thorax twice to four times as broad as in the abdomen. Both joints are separated by an oblique, internal, lumbar septum, which in some specimens observed was more oblique than in that figured; some specimens had a very irregular form. Dimensions. — Length of the three joints, a 0-025 to O'OS, b O'OS to O'O?, c O'OS to 0-04 ; breadth, a 0-04, b 0-09, c 0-08. Habitat. — Central Pacific, Station 265, depth 2900 fathoms; also fossil in Barbados. 12. Theocorys alauda, Haeckel. Eucyrtidium alauda, Ehrenberg, 1875, Adliandl. d. k. Akad. d. Wiss. BerKn, p. 72, Taf. ix. fig. 4. Shell nearly spindle-shaped, decreasing from the thicker middle towards both ends. Length of the three joints = 1:3:8, breadth = 1:4:5. Cephalis subspherical, with a strong, conical horn of three times the length. Thorax campanulate, with numerous regular, circular, quincuneial pores. Abdomen inversely ovate, slender, twice as broad as the truncated mouth, with irregular, roundish pores, three to four times as large as those of the thorax. Dimensions. — Length of the three joints, a 0-02, h O'OG, c 016 ; breadth, a 0-03, b 0-08, c 01. Habitat. — Fossil in Barbados and in Tertiary rocks of Sicily. 13. Theocorys ajJollinis, u. sp. (PI. 69, figs. 3). Shell ovate, with two deep strictures. Length of the three joints = 2:3:5, breadth = 2:5:7. Cephalis subspherical, with a large, straight, cylindrical horn, about as long as the whole shell (in the specimen figured this is broken off). Thorax truncate, conical. Abdomen subglobose, truncate on both poles, twice as broad as the constricted mouth. Pores quincuneial, subregular, circular, twice as broad in the abdomen as in the thorax. Dimensions. — Length of the three joints, a 0-02, b 0-03, c O'OS ; breadth, a 0-02, b O'OS, c 0-07. Habitat. — South Atlantic, Station 332, surface. 14. Theocorys sph(Bro2}hila, Haeckel. Eucyrtidium spluerophilum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 72, Taf. viii. fig. 16. Shell almost ovate, rough, with two slight strictures. Length of the three joints = 2 : 7: 10, breadth = 3 : 8 : 12. Cephalis subspherical, with a strong, conical horn of the same length. Thorax nearly spherical, with subregular, circular pores of different sizes. Abdomen ovate, truncate at both poles, nearly twice as broad as the constricted mouth, with very large, subregular, hexagonal pores, four to six times as broad as the bars, in three to four transverse, and ten to twelve longi- tudinal rows. Dimensions. — Length of the three joints, a 0-02, b 0-07, c 01 ; breadth, a 0-03, b 0-08, c 012. Habitat. — Central Pacific, Station 266, depth 2750 fathoms ; fossil in Barbados. REPORT ON THE RADIOLARIA. 1419 15. Tlieocorys tuhercxdata, n. sp. Shell almost ovate, tuberculate, with deep collar, but slight lumbar stricture. Length of the three joints =2 : 5 : 12, breadth = 3: S : 11. Cephalis hemispherical, with a cylindrical horn of twice the length. Thorax hemispherical, with regular, circular, double-edged, quincuncial pores, between which conical tubercles occur. Abdomen truncate, ovate, twice as broad as the constricted mouth, with regular, circular, hexagonally-framed pores, three to four times as broad as those of the thorax. IHmensions. — Length of the three joints, a 0-02, b 0-05, c 012 ; breadth, 0-03, b 0-08, c Oil. Habitat. — Tropical Atlantic, Station 348, depth 2-450 fathoms ; fossil in Barbados. 16. Tlieocorys martis, n. sp. Shell slender, ovate, with two deep strictures. Length of the three joints = 3 : 6 : 18, breadth = 4: 8 : 12. Cephalis small, hemispherical, with a very large, sword-shaped broad horn, nearly as long as the whole shell. Thorax hemispherical, honey-comb like, with regular, cucular, hexagon- aUy-framed pores. Abdomen ovate, with irregular, roundish, very large pores, four to six times as broad as the bars, and as the pores of the thorax. Constricted mouth half as broad as the abdomen. Dimensions. — Length of the three joints, a 0'03, b 0'06, c 018 ; breadth, a O'Ol, b O'OS, c 012. Habitat. — South Pacific, Station 295, depth 1500 fathoms. 17. Tlieocorys mercurii, n. sp. Shell ovate, conical, with two slight strictures. Length of the three joints = 1:3:7, breadth = 2:4:7. Cephalis hemispherical, with a broad pyramidal horn of the same length. Thorax campanulate, with longitudinal series of small, regular, circular pores, separated by divergent crests. Abdomen nearly spherical, one and a half times as broad as the constricted mouth, which is pro- longed into a thin, solid, cylindrical peristome. Pores of the abdomen regular, circular, hexa- gonaUy framed, three to four times as broad as the bars, and as the pores of the thorax. Dimensions. — Length of the three joints, a 0'02, b 0'06, c 015 ; breadth, a 0'04, b 0'09, c 015. Habitat. — South Atlantic, Station 338, depth 1990 fathoms. 18. Tlieocorys minervce, u. sp. (PI. 69, fig. 14). Shell ovate, conical, with two deep strictures. Length of the three joints = 1 : 3:4, breadth = 1:4: 5. Cephalis subspherical, with a large pyramidal horn as long as the thorax, and with small, circular pores. Thorax rough, with regular, quincuncial, circular pores, three to four times as large as those of the cephalis. Abdomen barrel-shaped, with irregular, roundish pores of very different sizes, six very large pores immediately beyond the lumbar stricture, and four to five rows 1420 THE VOYAGE OF H.M.S. CHALLENGER. of pores, which are twice to four times as large as those of the thorax. Mouth truncated, with thickened margin, two-thirds as broad as the abdomen. Dimensions. — Length of the three joints, a 0-04, h 0-12, c 0-16; breadth, a 0-04, h 016, c 02. Habitat— Genixdl Pacific, Station 268, depth 2900 fathoms. Genus 620. Axocorys,^ Haeckel, 1881, Prodromus, p. 434. Definition. — Theocorida (vel Tricyrtida eradiata aperta), with ovate abdomen, including an internal vertical axial rod, which bears three divergent radial spines or verticUs of three branches, and is prolonged into an apical horn. The genus Axocorys contains only a single but very remarkable species, and may, perhaps, represent a peculiar group, which has closer relations to the Plectoidea than to the other Tricyrtida. The pyriform three-jointed shell has neither lateral nor terminal free appendages, but possesses a very large apical horn, and an inner pro- longation of this, an axial rod, which bears some triradiate verticds of branched spines. The original ancestral forms of this remarkable genus are probably Plagoniscus and Plectaniscus (pp. 912 and 924). 1. Axocorys macroceros, n. sp. (PL 68, figs. 1, la). Shell pear-shaped, with two distinct strictures. Length of the three joints = 2 : 3 : 16, breadth = 3:6:16. Cephalis hemispherical, with few small pores. From its apex arises vertically a very long three-sided prismatic horn with denticulate edges, three to four times as long as the shell. An inner thin prolongation of the horn descends vertically nearly to the mouth, and bears on its basal end three verticils of branched spines, each verticil with three divergent forked spines (fig. 1«). Pores regular, circular, in the subspherical abdomen three times as large as in the hemi- spherical thorax. The constricted mouth is scarcely broader than the thorax. Dimensions. — Length of the three joints, a 0-02, b O'OS, c 0-16 ; breadth a 0-03, h 0-06, c 016. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 621. Lophocorys,' Haeckel, 1881, Prodromus, p. 434. Definition. — T heocorida (vel Tricyrtida eradiata aperta), with ovate abdomen, broader than the constricted mouth. Cephalis with two divergent horns, or with a bunch of horns. ' .4a;oco?'i/s = Helmet with an internal axis; eZfis, xo'^t/f. ^ Zioy/iocorj/s — Helmet with a top crest; y^o(pos, xi^vs- REPORT ON THE RADIOLARIA. • 1421 The genus Loj^hocorya differs from its cancestral form, Theocorys, only in the armature of the cophalis, bearmg either two divergent horns, or a corona of several radial horns. In two species there are four horns on the apex, a larger vertical (occipital) horn being surrounded by three smaller, upwards divergent horns. 1. Lophocorys astrocephala, n. sp. (PI. 69, fig. 9). Shell smooth, inversely ovate, with deep collar and slight lumbar stricture. Length of the three joints = 3 : 7 : 6, breadth = 4 : 11 : 10. Cephalis subspherical, stellate, densely covered with numerous (ten to twenty or more) divergent, large, slenderly conical horna, the longest of which reach the length of the shell. Thorax campanulate, with small, regular, circular pores. Abdomen taper- ing towards the constricted mouth, in the upper half with the same pores, in the lower half with smaller, scarce pores, or nearly hyaline. J)imensio7is. — Length of the three joints, a 0'03, h 0"07, c O'OS ; breadth, a 0'04, b OH, c 01. Hahitat. — Central Paicific, Station 266, depth 2750 fathoms. 2. Lophocorys acanthocephala, Haeekel. Eueyrtidium acanfhoeephalum, Ehienberg, 1875, Abliandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. ix. fig. 8. Shell rough, bottle-shaped, with two slight strictures. Length of the three joints = 5:11:7, breadth = 4 : 12 : 10. Cephalis conical, with a large pyramidal horn of the same length, and three smaller divergent accessory horns at the base of the three edges of the latter. Thorax campanulate, nearly as long as the tapering abdomen (which in the figure of Ehrenberg is broken off). Pores regular, circular, quincuncial. Dimensions. — Length of the three joints, a 0'05, b Oil, c 007 ; breadth, a 0'04, b 0'12, c 01. Habitat. — Fossil in Barbados. 3. Lophocorys bicornis, Haeekel. Eueyrtidium bicome, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xi. fig. 7. Shell smooth, almost spindle-shaped, with two slight strictures. Length of the three joints = 2:8:3, breadth = 3 : 5:4. Cephalis hemispherical, with two stout, pyramidal, divergent horns of twice the length. Thorax ovate, with seven to eleven transverse rows of small, regular, circular pores (often very scarce in the upper half). Abdomen with two to four transverse rows of the same pores. Mouth constricted, half as broad as the thorax. Dimensiom. — Length of the three joints, a 0'02, b 0'08, c 0'03 ; breadth, a 0'03, b 0'05, c 0'04. Habitat. — Fossil in Barbados. 1422 THE VOYAGE OF H.M.S. CHALLENGER. 4. Lopliocorys quadricornis, n. sp. Shell rough, slenderly ovate, with two distinct strictures. Length of the three joints = 2 : 4 : 2, breadth = 2:4:3. Cephalis ovate, with four very stout, three-sided prismatic horns ; the largest is as long as the thorax and vertical upon the apex, the three smaller are as long as the cephalis and diverge upwards from the base of the former. Thorax ovate, with large, irregular, roundish pores, which are three to four times as broad as the small, circular pores of the first and the third joint. Constricted mouth half as broad as the thorax. Dimensions. — Length of the three joints, a 0-045, h 0-085, c 0-04 ; breadth, a 0-035, I 0-075, c 0-06. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 5. Lophocorys hovicornis, n. sp. (PI. 69, fig. 12). Shell rough, subovate, with two deep strictures. Length of the three joints =1:2:3, breadth = 1:3:4. Cephalis subspherical, with two divergent, curved horns of different lengths. Thorax cam- panulate, with small, circular pores. Abdomen subspherical, truncate at both poles, twice as broad as the constricted mouth, thorny, with very large, circular pores, four to six times as broad as those of the smaller thorax. Dimensions. — Length of the three joints, a 0-03, h 0-06, c 0-09 ; breadth, a 0-04, h 0-09, c 0-12. Habitat. — Central Pacific, Station 270, depth 2925 fathoms. Genus 622.. Theocampe,^ n. gen. Definition. — T heocorida (vel Tricyrtida eradiata aperta) with ovate abdomen, broader than the constricted mouth. Cephalis without horn. The genus Tlieocampe differs from the two preceding genera in the absence of horns on the cephalis, and may, therefore be derived from Theocorys by reduction of the apical horn. It bears to the latter the same relation as Tricolocampe does to Tlieocyrtis. Subgenus 1. Theocampana, Haeckel. Definition. — Pores of the thorax and the abdomen of nearly equal size and similar form. 1. Theocampe ehrenhergii, Haeckel. Didyomitra ehrenhergii, Zittel, 1876, Zeitschr. d. deutsch. geol. Gesellsch., ji. 82, Taf. ii. fig. 5. Shell ovate, smooth. Length of the three joints = 2: 3: 13, breadth = 4: 7: 12. Cephalis hemispherical. Thorax truncate, conical. Abdomen inflated, nearly spherical, twice as broad as the constricted mouth. Pores of nearly equal size and form, small, regular, circular. 1 Theocampe = Di\{ne caterpillar ; hog, nafivji. REPORT ON THE RADIOLARIA. 1428 Bbmnsioiis.. — Length of the three joints, a 0-014, h O'OIS, c 0-076 ; breadth, a 0-023, h 0-044, c 0-073. Habitat. — Fossil in the chalk of Northern Germany ; Brunswick (Zittel). 2. Theocampe pirum, Haeckel. Eucyrtid ium piruin, 'Eh.TenheTg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 72, Taf. x. fig. 14. Eucyrfidium excellens, Biitschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 540, Taf. xxxiii. fig. 31. Shell ovate, smooth. Length of the three joints = 3 : 5 : 15, breadth = 6 : 10 : 16. Cephalis hemispherical. Thorax truncate conical. Abdomen inflated, subspherical, three times as broad as the constricted mouth. Pores of nearly equal size, regular, circular, in the thorax alternating, in the abdomen disposed in five to six transverse, widely distant rows. Dimensions. — Length of the three joints, a 0-015, h 0-025, c 0-075 ; breadth, a 0-03, h O'Oo, c 0-08. Habitat. — Fossil in the Tertiary rocks of Barbados. 3. Theocampe stenostoma, n. sp. (PI. 66, fig. 23). Shell aliout ovate, smooth. Length of the three joints = 3:4: 3, breadth = 6 : 8:9. Cephalis hemispherical, large. Thorax and abdomen short, barrel-shaped. Both strictures deep. Abdomen three times as broad as the constricted mouth. Pores of equal size, regular, circular, disposed in oblique rows. Dinunsions. — Length of the three joints, a 0-03, h 0-04, c 003 ; breadth, a 0-06, h 0-08, c 0-09. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 4. Theocampe nucula, Haeckel. Eucyrtidium nucula, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 29, Taf. vii. fig. 19. Shell nearly ovate, rough. Length of the three joints = 3 : 5": 3, breadth = 4 : 7 : 6. Cephalis hemispherical, large. Thorax and abdomen inflated. Both strictures deep. Thorax broader than the short abdomen, and twice as broad as the constricted mouth. Pores of equal size, regular, circular, regularly disposed in transverse rows : three in the cephalis, six in the thorax, and three in the abdomen. Dimensions. — Length of the three joints, a 0-03, h 0-05, c 0-03 ; breadth, a 0-04, b 0-07, c 0-06. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms ; also fossil in Barbados. 5. Theocampe cryptoprora, Haeckel. Eucyrtidium cryptoprora, Ehrenberg, 1872, AbhandL d. k. Akad. d. Wiss. Berlin, p. 291, Taf. vii. fig. 14. Shell ovate, thin-waUed, smooth, without external strictures, but with two distinct internal annular septa. Length of the three joints = 2:7:4, breadth = 3:7:6. Cephalis, large, subspherical. 1424 THE VOYAGE OF H.M.S. CHALLENGER. hyaline ; its lower half hidden in the upper part of the campanulate thorax. Mouth little con- stricted, nearly as broad as the truncate abdomen. All pores equal, small, regular, circular. Diinensions. — Length of the three joints, a 0-025, h 0-07, c 0-04 ; breadth, a 0-03, h 0'07, c O'OG. Habitat. — Tropical Pacific, Stations 225 to 265, in various depths. 6. Theocampe ovulum, n. sp. Shell perfectly ovate, thick-walled, smooth, without external strictures, but with two broad, internal septa. Length of the three joiuts = 2 : 3 : 10, breadth = 3 : 6 : 8. Cephahs and thorax together obtuse, conical, with obliquely ascending pores. Abdomen inflated, twice as broad as the constricted mouth, with ten to twelve transverse rows of pores. All pores equal, small, regular, circular. Dimensions. — Length of the three joints, a 0-02, b O'OS, c 01 ; breadth, a O'Oo, h 0-06, c 0-08. Habitat. — Fossil in Tertiary rocks of Barbados and Sicily. 7. Tlieocampe cassis, Haeckel. Hucyrtiditim cassis, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. vii. fig. 20. Shell bottle-shaped, thin-walled, with slight collar, but deep lumbar stricture. Length of the three joints = 3 : 8 : 6, breadth = 2 : 7 : 7. Cephalis ovate. Tliorax campanulate. Abdomen .inflated, twice as broad as the constricted mouth. Pores equal, regular, circular, disposed in quincuncial rows. Limmmons. — Length of the three joints, a 0-03, b 0-08, c 0-06 ; breadth, a 0-02, b 0-07, c 01)7. Habitat. — Tropical Pacific (Philippines), Station 206, depth 2100 fathoms. Subgenus 2. Theocamptra, Haeckel. Definition. — Pores of the thorax and the abdomen of different sizes or dissimilar forms. 8. Theocampe sphoBrothorax, n. sp. (PI. QQ, fig. 25). Shell almost ovate, rough. Length of the three joints = 2:5:10, breadth = 3:8:8. Cephalis hemispherical. Thorax nearly spherical, truncate. Abdomen ovate, twice as broad as the constricted mouth. Pores subregular, circular, quincuncially disposed, in the abdomen twice as broad as in the thorax, and four times as broad as in the cephalis. Dimensions. — Length of the three joints, a 0-025, b 0-05, c O'l ; breadth, a 0-03, b 0-08, c 0-08. Habitat. — Central Pacific, Stations 263 to 274, depth 2350 to 2925 fathoms. REPORT ON THE RADIOLARIA, 1425 9. Tlieocampe versipeUis, Haeckel. Etiryrtidium versipeUis, Ehrenberg, 1875, Abhandl. d. k. AkaJ. d. Wiss. Berlin, p. 72, Taf. xi. fig. 14. Shell slenderly ovate, rough. Length of the three joints = 3:5:13, breadth = 4:8:9. Cephalis subspherieal, without pores. Thorax hemispherical. Abdomen inflated, twice as broad as the constricted mouth. Pores subregular, circular, quincuncially disposed, in the abdomen three times as broad as in the thorax. Dimensions. — Length of the three jomts, a 0-025, h 0-05, c 013 ; breadth, 0-04, b O'OS, c 0-09. Habitat. — Fossil in Barbados. 10. Theocampe megalopora, Haeckel. Eucrjrtidium megaloporum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. vii. fig. 19. Shell almost ovate, with two distinct strictures. Length of the three joints = 2:6:3, breadth = 3:6:4. Cephalis hemispherical. Thorax ovate, inflated. Abdomen inversely ovate, two to three times as broad as the constricted mouth. Pores subregular, circular, quincuncially disposed, twice as broad in the large thorax as in the smaller abdomen. Dimensions. — Length of the three joints, a 0-02, b 0-06, c 0-03 ; breadth, a 0-03, b 006, c 0-04. Habitat. — Central Pacific, Station 267, depth 2700 fathoms. 11. Theocampe collaris, n. sp. (PI. QQ, fig. 18). Shell almost ovate, with two distinct strictures. Length of the three joints = 3:3:6, breadth = 4:5:7. Cephalis obtuse conical, with five or six transverse rows of small pores. Thorax truncate conical, with longitudinal furrows, each of which contains a single pore. Abdomen inflated, with five or six distant, transverse rows of small, circular pores. DiTnensums. — Length of the three joints, a 0-03, b 0-03, c 0-06 ; breadth, a 0-04, b 0-05, c 0-07. Habitat. — South Pacific, Station 295, depth 1500 fathoms. 12. Theocampe gemmata, Haeckel. Eucyrtidium gemmatuni, Ehrenberg, 1875, AbhandL d. k. Akad. d. Wiss. Berlin, p. 70, Taf. X. fig. 6. Shell slenderly ovate, smooth, with two internal annular septa. Length of the three joints = 1:1:4, breadth = 1:2:3. Cephalis campanulate, nearly as large as the truncate, conical thorax, both with small, irregular, obliquely descending pores. Abdomen broader, twice as broad as the constricted mouth, with numerous longitudinal ribs, alternating with single rows of small, circular pores. (Tills and the following allied species approach to Cydadophora, by the abdominal ribs.) Dimensions. — Length of the three joints, a 0-02, b 0-02, c 0-07 ; breadth, a 0-025, b 0-035, c 0-045. Habitat. — Fossil in Barbados. (ZOOL. CHALL. EXP. — PART XL. — 1886.) Er 179 1426 THE VOYAGE OF H.M.S. CHALLENGER. 13. Theocampe costata, n. sp. (PI. QQ, fig. 24). Shell almost ovate, with two sharp strictures. Length of the three joints = 2:4:8, breadth = 3:5:7. Cephalis hemispherical. Thorax twice as large, also hemispherical, both with regular, circular, quincuncial pores. Abdomen broader, with numerous longitudinal ribs, alternating with longitudinal rows of larger jjores. Mouth constricted, half as broad as the thorax. Dimensions. — Length of the three joints, a 0-02, b 0'04, c 0-08 ; breadth, a O'Oo, h 0-05, c 0-07. Habitat. — Indian Ocean, Sunda Straits (Eabbe), surface. 14. TTieocampe cryptocephala, Haeckel. Eucyrtidium cryptocephalum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Beilin, p. 70, Taf. xi. fig. IL Shell ovate, rough, with two distinct strictures. Length of the three joints = 1:2:4, breadth = 1:4:5. CeiAalis subspherical, its lower half hidden in the campanulate thorax. Abdomen subspherical, twice as broad as the constricted mouth. Pores subregular, circular, quincuncial, twice as broad in the abdomen as in the thorax. Dimensions. — Length of the three joints, a 0-02, b 0-04, c 0-07 ; breadth, a 0-025, b 0-07, c 0-09. Habitat. — Fossil in Barbados. Subfamily 2. Theocapsida, Haeckel, 1881, Prodromus, p. 436. Definition. — Theocyrtida with the basal mouth of the shell fenestrated (vel Tricyrtida eradiata clausa). Genus 623. Tlieocapsa,^ Haeckel, 1881, Prodromus, p. 436. Definition. — Theocapsida (vel Tricyrtida eradiata clausa), with an apical horn, and a terminal lattice-plate on the mouth. The genus Theocapsa, and the two following genera, represent together the small subfamily of Theocapsida, or of those Tricyrtida in which the mouth is closed by a lattice- plate, and external radial appendages are wanting. Theocapsa may be derived from Theocorys by fenestration of the constricted mouth. Subgenus 1. TJieocapsetta , Haeckel. Definition. — Thorax of about the same size as the abdomen, or somewhat larger ; pores of both nearly equal in size and similar in form. ' Theocapsa = T)ivme capsule ; do;, Kaipa. REPORT ON THE RADIOLARIA. 1427 1. Theocapsa aristotelis, n, sp. (PI. QQ, fig. 6). Shell subovate, smooth, with two distinct strictures. Length of the three joints = 2:6:7, breadth = 3:8:8. Cephalis hemispherical, with a conical, slender horn of about the same length. Thorax and abdomen nearly equal in size, thin-walled, smooth, with small, regular, circular pores of equal size. Basal pole rounded. BiTnensions. — Length of the three joints, a 0-02, b 0-06, c O'OV ; breadth, a 0-03, h O'OS, c O'OS. Habitat — Mediterranean (Gibraltar), Atlantic (Canary Islands), surface. 2. Theocapsa plinii, n. sp. Shell subovate, smooth, with two indistinct strictures. Length of the three joints = 2 : 5 : 6, breadth = 3:7:7. Cephalis hemispherical, with a pyramidal, thick horn of about the same length. Thorax and abdomen of nearly equal size, thick-walled, rough, with large, regular, circular, doixble- edged pores of equal size (twice as large and half as numerous as in the similar preceding species). Bimemions. — Length of the three joints, a 0-02, b 0-05, c 0-06 ; breadth, a 0-03, b 0-07, c 0-07. Habitat. — Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms. 3. Theocapsa democriti, n. sp. (PL QQ, fig. 8). Shell slender, ovate, spiny, with two distinct strictures. Length of the three joints = 3:5:6, breadth = 4:7:7. Cephalis ovate, with numerous slender horns of the same length. Thorax and abdomen with small, irregular, roundish pores of nearly equal size, armed with scattered slender spines, half as long as the cephalic horns. Basal pole hemispherical, rounded. Dimensions. — Length of the three joints, a 0-03, b 0-05, c O'OO ; breadth, a OM, b 0-07, c 0-07. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 4. Theocapsa galeni, n. sp. Shell broadly ovate, spiny, with two deep strictures. Length of the three joints = 2:7:6, breadth = 3:8:7. Cephalis hemispherical, with two conical, divergent horns of the same length. Thorax and abdomen with large, irregular, roundish pores of nearly equal size, armed with numerous short spines, not larger than the pores. Basal pole conical, pointed. Bimensimis. — Length of the three joints, a 0'02, b 0*07, c 0"06 ; breadth, a 0"03, b 008, c 0"07. Habitat. — Xorth Pacific, Station 253, depth 3125 fathoms. Subgenus 2. Theocapsilla, Haeckel. Definition. — Thorax of about the same size as the abdomen, or somewhat larger ; pores of the two difiereut in size or form. 1428 THE VOYAGE OF H.M.S. CHALLENGER. 5. Theocapsa wottonis, n. sp. (PI. QQ, fig. 11). Shell subovate, rough, with two deep strictures. Length of the three joints = 3:7:5, breadth = 3:9:8. Cephalis subspherical, with regular, circular, hexagonaUy-framed pores, and with a stout pyramidal horn of the same length. Thorax conical, with subregular, circular, double-edged pores. Abdomen hemispherical, smaller and thinner walled, with irregular, somewhat oblong pores. Basal pole rounded. Dimensions. — Length of the three joints, a 0-03, h 0-07, c 0-05 ; breadth, a 0-03, h 0-09, c 0-08. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 6. Theocapsa gessneri, n. sp. Shell broadly ovate, with two deep strictures. Length of the three joints = 3:9:5, breadth = 4:10:4. Cephalis hemispherical, with a slender, conical horn of the same length. Thorax sub- spherical, with small, regular, circular pores. Abdomen inversely conical, with few large, somewhat oblong pores. Basal pole acute. Dimensions. — Length of the three joints, a 0'03, h 0'09, c 0'05 ; breadtli, a 004, h 0"1, c 004. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 7. Theocapsa aldrovandi, n. sp. Shell slender, inversely ovate, with two slight strictures. Length of the three joints = 3 : 8 : 14, breadth = 4 : 11 : 8. Cephalis subglobular, with a conical horn of the same length. Thorax also subglobular, papillate, with regular, circular, hexagonally-framed pores. Abdomen inversely conical, slender, with very small and numerous, subregTilar, circular pores. Basal pole ovate, pointed. Dimemions.— Length of the three joints, a 0-03, b 008, c 014; breadth, a 004, b Oil, c 0-08. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms, 8. Theocapsa malpighii, n. sp. (PI. 66, fig. 15). Shell inversely ovate, witli two distinct strictures. Length of the three joints = 3 : 8 : 11, breadth = 4:9:8. Cephalis hemispherical, with a conical horn of the same length. Thorax hemi- spherical, thorny, with very small circular pores, surrounded by large, regular, hexagonal frames. Abdomen inversely campanulate, with larger circular pores, and longitudinal ribs. Basal pole blunt, conical. Dimensions. — Length of the three joints, a 0-03, h 0-08, c Oil ; breadth, a 0-04, b 0-09, c 0-08. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. Subgenus 3. Theocapsomma, Haeckel. Definition. — Thorax much smaller than the abdomen, pores of the two nearly equal in size and similar in form. REPORT ON THE RADIOLARIA. 1429 9. Theocapsa linncei, u. sp. (?1. QQ, fig. 13). Shell slender, subcylindrical, rough, with two slight strictures. Length of the three joints = 1:3:6, breadth = 1:4:4. Cephalis hemispherical, with a pyramidal horn of twice the length (sometimes, as in the specimen figured, one or two small accessory horns occur at its base). Thorax liemispherical, thick-waUed. Abdomen nearly cylindrical, twice as long as the thorax, thin-walled, with a hemispherical, rounded basal pole. The specimen figured is an abnormal one, with some deformities on the irregular abdomen ; in numerous other specimens the abdomen is cylindrical, regular. Pores of the thorax and abdomen equal, very small and numerous, regular, circular, three to four times as broad as the bars. Dimensions. — Length of the three joints, a 002, h 0-05 to 006, c 01 to 012 ; breadth, a O'OS, 6 0-06 to 0-07, c 007 to 008. Habitat. — Cosmopolitan; Atlantic, Indian, and Pacific Oceans; many Stations at various depths. 10. Theocapsa forskalii, n. sp. (PI. QQ, fig. 9). Shell slender, subcylindrical, smooth, with two slight strictures. Length of the three joints = 1:1:3, breadth-= 1:2:2. Cephalis hemispherical, with a conical horn of half the length. Abdomen three times as long as the thorax, of the same breadth, with the same irregular, roundish pores, large and small intermingled. Basal pole rounded. Dimensions. — Length of the three joints, a 0-02, b O'OS, c 0-09 ; breadth, a 0-03, b 0-06, c 006. Habitat. — North Atlantic, Canary Islands, Station 353, depth 2965 fathoms. 11. Theocapsa loolffii, n. sp. (PI. QQ, fig. 14). Shell slender, spindle-shaped, very thick-walled, rough, without external strictures, but with two broad internal girdles. Length of the three joints = 2 : 3 : 15, breadth = 4 : 5 : 7. Cephalis with a short horn of the same length, conical. Abdomen five times as long as the thorax, with the same subregular, circular pores. Basal pole inversely conical, with some larger, elongate pores. Dimensions. — Length of the three joints, a 0'02, h O'OS, c 015 ; breadth, a 0'04, b 0'05, c 0'07. Habitat. — Mediterranean, Crete, depth 1620 fathoms (Spratt). 12. Theocapsa pallasii, n. sp. Shell subovate, thorny, with two slight strictures. Length of the three joints = 1:2:3, breadth = 1:2:3. Cephalis ovate, with a pyramidal horn of the same length. Thorax and abdomen with subregular, circular pores of medium size. Basal pole hemispherical. (Differs from Tlicoeapsa mulleri, PI. 66, fig. 7, mainly in the larger number and smaller size of the regular, quin- cuncial pores.) Dimensions. — Length of the three joints, a O'OS, b 0-06, c 0-09 ; breadth, a 0-03, h 0-06, c 0-09. Habitat. — Tropical Atlantic, Station 342, depth 1445 fathoms. 1430 THE VOYAGE OF H.M.S. CHALLENGER. Subgenus 4. Theocapsura, Haeckel. Definition. — Thorax much smaller than the abdomen, pores of the two difiereut in size or form. 13. Tlieocapsa lamarckii, n. sp. (PI. QQ, fig. 16). Shell slenderly ovate, rough, with two distinct strictures. Length of the three joints = 1 : 2 : 7, breadth = l : 4 : 5. Cephalis subspherical, with a conical horn of twice the length. Thorax conical, with regular, circular pores. Abdomen three times longer, with subregular, hexagonal pores of twice the size. Basal pole hemispherical, with very large, irregular, roundish pores. Dimensions. — Length of the three joints, a 0"02, 6 O'OS, c 014 ; breadth, a 0'03, b 0'08, c O'l. Habitat. — Indian Ocean, Madagascar (Eabbe), surface. 14. Tlieocapsa cuvieri, n. sp. (PL Q6, fig. 10). Shell slenderly spindle-shaped, thorny, with two slight strictures. Length of the three joints = 1:3:6, breadth = 1:3:3. Cephalis subspherical, with a conical horn of the same length. Thorax conical, spiny, with regular, circular, double-edged pores. Abdomen thinner-walled, inversely conical, with irregular, roundish pores. Basal pole acute, with a bunch of larger spines. Dimensions. — Length of the three joints, a 0'02, b 0'05, c 0"12 ; breadth, a 0-02, b 0'05, c 0-06. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 15. Tlieocapsa haerii, n. sp. Shell slenderly spindle-shaped, smooth, with two indistinct strictures. Length of the three joints =1:2:8, breadth =2:3:4. Cephalis hemispherical, with a tliick, conical horn of the same length. Abdomen four times as long as the thorax. Pores in the thorax small and numerous, regular, circular, in the abdomen twice as large, and irregularly roundish. Basal pole inversely conical, acute. (Differs fi-om Tlieocapsa wolffii, PI. 66, fig. 14, mainly in the shape of the pores.) Dimensions. — Length of the three joints, a 0-015, b O'OS, c 0-12 ; breadth, a 0-03, b 0-04, c O'OG. Habitat. — North Pacific, Station 241, depth 2300 fathoms. 16. Tlieocapsa rathkei, n. sp. Shell slenderly conical, with two slight strictures. Length of the three joints= 1 : 2 : 10, breadth = 2:4:15. Cephalis small, with a large, conical horn of three times the length. Thorax small, thorny, with small, irregular, roundish pores. Abdomen very large, as long and as broad as the thorax, with irregular, polygonal or roundish, very large pores, the margin of which is finely denticulate. Basal pole truncate, rounded. Dimc7isians. — Length of the three joints, a 0-02, b 0-05, c 0-2 ; breadth, a O'Ol, b O'OS, c O'S. Habitat. — Fossil in Barbados. REPOKT ON THE RADIOLARIA. 1431 17. Tlieocapsa schwannii, u. sp. Shell slenderly ovate, or pear-shaped, with two distinct strictures. Length of the three joints = 1 :2 : 7, liveailth = 2 : 4 : 7. CephaUs siibspherical, small, with a stout, pyramidal horn of three times the length. Cavity of the thorax subspherical, its thick wall with small, regular, circular, hexagonaUy-fi'amed pores. Abdomen very thick-walled, with crested bars, and very large, irregular, roundish pores. Basal pole rounded, truncate. DimcTisions. — Length of the three joints, a 0'02, b 0'04, c 014 ; breadth, a 0'04, h 0-08, c 014. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 18. Tlieocapsa mulleri, u. sp. (PI. QQ, fig. 7). Shell slenderly ovate, or pear-shaped, spiny, with two indistinct strictures. Length of the three joints = 1:2:3, breadth =1 : 2 : 3. Cephalis ovate, with a stout, pyramidal horn of the same length, and with a variable number of smaller accessory horns. Pores irregular, roundish, three to four times as broad in the inflated abdomen as in the thorax. Basal pole hemispherical, spiny. Dimensions. — Length of the three joints, a 0*03, b 0-05, c O^OQ ; breadth, a 0'03, b 0'07, c 0'09. Habitat. — Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms. 19. Tlieocapsa sarsii, n. sp. Shell pear-shaped, with two indistinct strictures. Length of the three joints = 1 : 1 : 3, breadth = 1:2:4. Cephalis with a thick horn of the same length, conical. Abdomen subspherical, very thick-walled, its pores regular, circular, twice as broad as the bars, and three times as broad as those of the thorax. Basal pole flat, rounded. Dimensions. — Length of the three joints, a 0'04, b 0'05, v 0'12 ; breadth, a O'Oo, b O'll, c 015. Habitat. — Fossil in Barbados. 20. Tlieocapsa darivinii, n. sp. (PL QQ, fig. 12). Shell pear-shaped, with two distinct strictures. Length of three joints = 1:1:5, breadth = 1:2:5. Cephalis hemispherical, with a conical horn of twice the length. Thorax campanulate, with small, regular, circular pores. Abdomen broad, ovate, with larger, regular, circular, hexagon- ally-framed pores. Basal pole hemispherical. Dimensions — Length of the three joints, a 0'03, b 0"04, c 0-2 ; breadth, a 0-04, b 0'08, c 0-2. Habitat.~C%iAm\ Pacific, Stations 263 to 274, depth 2350 to 2925 fathoms. Genus 624. Tricolocapsa,^ Haeckel. Definition. — T heocapsida (vel Tricyrtida eradiata clausa) without apical horn, with a terminal lattice-plate on the mouth. ' 3Vtcoiocapsa = Three-jointed capsule ; t;;«5xo», >ta4'«. 1432 THE VOYAGE OF H.M.S. CHALLENGER. The genus Tricolocapsa differs from the preceding Theocapsa in the loss of the apical horn, and exhiliits therefore to it the same relation that Theocamjye bears to Tlieocorys. In some species (PL QQ, figs. 1, 3) a small tube begins to be developed on the cephalis, and these may perhaps be separated as a pecuUar genus, Tricolopera. Subgenus 1. Tricoloeapsula, Haeckel. Definition. — Thorax of about the same size as the abdomen, or larger. 1. Tricolocap)sa thcop>hrasti, n. sp. (PI. QQ, fig. 1). Shell slenderly ovate, with two slight strictures. Length of the three joints = 2:8:5, breadth = 3:7:5. Cephalis hemispherical, with a larger, tube-like, cervical pore at the collar stricture. Thorax very thick-walled, with irregular, roundish, double-edged pores, smaller than the bars between them. Abdomen smaller, inversely campanulate-conical, with very irregular pores. Basal pole acute. Dimensions. — Length of the three joints, a 0-02, I O'OS, c 0-05 ; breadth, a 0-03, h 0-07, c 0-05. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 2. Tricolocapsa dioscoridis, n. sp. (PL QQ, fig. 3). Shell short and broad, with two deep strictures. Length of the three joints = 3:5:4, breadth = 4:7:5. Cephalis hemispherical, with a lai-ger, tube-like, cervical jjore above the collar stricture. Thorax very broad, with irregular, large and spare, roundish pores. Abdomen much smaller, inversely conical, with smaller pores. Basal pole obtuse. JDimeTisions. — Length of the three joints, a 0'03, b 0'05, c 004 ; breadth, a 0'04, b 0-07, c 0-05. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 3. Tricolocapsa linncei, n. sp. (PL QQ, fig. 5). Shell short and broad, with two deep strictures. Length of the three joints =1:4:2, breadth = 1:4:2. Cephalis hemispherical. Thorax thick-walled, inflated, with subregular, circular, double- edged pores. Abdomen much smaller, thin-walled, with irregular, polygonal pores. Basal pole hemispherical, rounded. Dimensions. — Length of the three joints, a 0'02, h 0'08, e 0'05 ; breadth, a G'03, b 0'08, c 0'05. Habitat. — South Pacific, Station 295, depth 1500 fathoms. REPORT ON THE RADIOLARIA. 1433 4. Tricolocapsa decandollei, n. sp. (PI. QQ, fig. 4). Shell subovate, with two sharp strictures. Length of the three joints = 2:2:2, breadth = 3:4: 3'5. Cephalis campanulate. Thorax broader, ring-shaped. Abdomen inversely hemispheri- cal. All three joints of the same length, thick-walled, with the same regular and peculiar reticula- tion, the small circular pores being surrounded by square, elevated frames. Dimensions. — Length of the three joints, a 0-07, h 0-07, c 0-07 ; breadth, a 010, h 014, c 012. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. Subgenus 2. Tricolocapsium, Haeckel. Definition. — Thorax much smaller than the abdomen. 5. Tricolocapsa brownii, n. sp. Shell ovate, very thick-walled, with two indistinct strictures. Length of the three joints = 2 : 4 : 7, breadth = 3 : 7 : 10. Cephalis flat, hemispherical. Thorax truncate, conical. Abdomen inflated, inversely hemispherical. Pores regular, circular, of the same breadth as the bars, hexagonally- framed, twice as large in the abdomen as in the thorax. Basal pole rounded. Dimensions. — Length of the three jomts, a 0-02, h 0-04, c 0-07 ; breadth, a O'OS, b 0-07, c 01. Habitat. — Fossil in Barbados. 6. Tricolocapsa schleidenii, n. sp. (PI. QQ, fig. 2). Shell subcorneal, with two deep strictures. Length of the three joints = 2 : 3 : 6, breadth = 3:5:6. Cephalis subspherieal. Pores subregular, circular, arranged in transverse girdles, three in the broad thorax, six in the subglobular abdomen. Basal pole rounded. Dimensions. — Length of the three joints, a 0-02, I 0'03, c 0-06 ; breadth, a 0-03, b 0'05, c 0"06. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. Genus 625. Phrenocodon,^ n. gen. Definition. — Theocapsicla (vel Tricyrtida eradiata clausa) with an apical horn, and a lattice-plate between thorax and abdomen. The genus Phrenocodon difi"ers from the two preceding genera in the remarkable circumstance, that the basal lattice-plate closes not the terminal mouth itself, but the 1 Phrenocodon = 'Bt\i. with diaphiagm ; (pj^», kuouu. (ZOOL. CHALL. ESP. PAET XL. 1SS6.) El 180 1434 THE VOYAGE OF H.M.S. CHALLENGER. constricted opening between thorax and abdomen. It may therefore be regarded as a Sethocapsa, which has develoi^ed a third, open, abdominal joint. The cephalis bears an apical horn. 1. Phrenocodon clathrostomium, n. sp. (PI. 70, figs. 7, 8). Shell campanulate-conical, with two deep strictures. Length of the three joints = 2:6:3, breadth = 3 : 10 : 14. Cephalis hemispherical, with an oblique curved horn of the same length. Thorax subconical, with polygonal, roundish pores, increasing in size towards the girdle. A perfect fenestrated diaphragm, with irregular, roundish pores of very different sizes, separates the thorax from the abdomen. Tlie latter is composed of three parallel, circular rings, which are connected by fifteen to twenty radial beams. As the middle ring is larger than the two others, the beams between the large quadrangular pores are divergent in the upper, convergent in the lower girdle. Short prolongations of the divergent beams form a coronal around the middle ring (compare fig. 7 profile, fig. 8 from below). Dimensions. — Length of the three joints, a 0'02, b 0'06, c 0-03 ; breadth, a 0'03, & 01, c 014. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 2. Phrenocodon diaphragma, n. sp. Shell campanulate-conical, very sunUar to that of the preceding species, but with abdomen and pro- portions different. Length of the three joints = 1:3:2, breadth = 1:4:4. Abdomen cylindrical, with two or three transverse rows of large quadrangular meshes (fifteen to twenty in each row), without the characteristic inflexion of the preceding species, and without the coronal. Bimensioyis. — Length of the three joints, a 0-02, h 0-06, c 0-034 ; breadth, a 0-02, b O'OS, c 0-08. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Section IV. STICHOCYETIDA, Haeckel, 1862, Monogr. d. Radiol., p. 280, 312 (Pis. 75-80). Stichoeyriida et Tetraeyrtida, Haeckel, 1881, Prodromus, p. 437, 438. Definition. — C yrtoidea polythalamia, with annulated shell, divided by three to six or more transverse, horizontal constrictions, into four to seven or more annular joints. (The first joint represents the cephalis, the second the thorax, the third the abdomen, all the following joints together a post-abdomen.) REPORT ON THE RADIOLARIA. 1435 Family LXX. Lithocampida. No radial apophyses. Synopsis of the three Families and six Subfamilies of Stichocyrtida. . Stichopilida. . Stichopeiida. . Stichophormida. . StiohopliEeiiida. \ IMoutli open, I Mouth closed, Family LXVIII. Podocampida. Three radial apophyses. Family LXIX. Phormocampida. Numerous radial apophyses, } Mouth open, Mouth closed, 'j Mouth open, J Moutli close J, Stichocorida. Stichocapsida, Family LXVIII. Podocampida, n. fam. Artopilida et Artoperida, Stichopilida et Stichopm-ida, Haeckel, 1881, Prodi-omus, p. 437-439. Definition. — S tichocyrtida trii'adiata. (Cyrtoidea with an annulated slieU, divided by three or more transverse constrictions into four or more annular joints, and bearing three radial apophyses). The family Podocampida comprises those Cyrtoidea in which the lattice- shell is composed of numerous (four to eight or more) annular joints, and bears three external radial apophyses. It may be divided into two subfamilies, differing in the shape of the terminal mouth. This is a simple wide opening in the Stichopilida (and the united Artopilida), closed by a lattice-plate in the Stichoperida (and the united Artoperida). The phylogenetic origin of the Podocampida may be found in the Podocyrtida (p. 1314). Very few forms only of the Podocampida were hitherto known, viz., Stichoiyilium (^Pterocodon) davisianum, and three fossil species from Barbados, figured by Ehrenberg ; Artopera loxia (united by him with Lithornithium), and two species of Pteropilium {sphinx and homhiis, both united by him with the three-jointed Pterocanium). In general, the triradiate Stichocyrtida are much rarer and much poorer in specific forms than the tru'adiate Tricyrtida, then* ancestors. We have observed altogether only forty-four species, thirty Stichopilida, and fourteen Stichoperida ; the former are dis- posed among seven, the latter among three genera. The three radial apophyses appear either as lateral ribs or prominent wings in the thorax (PL 77, fig. 8—12), or as three terminal feet around the mouth (PI. 97, fig. 15). Sometimes the ribs are replaced by three radial combs, or rows of spines, and these may be united by three divergent beams, forming three vaulted bridges with numerous bows (PL 75, figs. 10, 11). The lateral wings or ribs, as well as the terminal feet, are either solid or fenestrated. 1436 THE VOYAGE OF H.M.S. CHALLENGER. L Subfamily Stichopilida. Mouth, of the ter- minal joint a simple wide opening. IL Subfamily Stichoperida. Mouth of the terminal joint closed by a lattice-plate. Synopsis of the Genera of Podocampida. ■ Lateral wings are f Cephalis with horn, solid spmes. ( ^ ^ Three lateral appen- dices or wings (no < terminal feet). Three terminal ap- pendices or feet at the peristome (all with cephalic horn). Lateral wings are latticed. Three lateral ribs or crests prolonged into the three ter- minal feet. No lateral ribs. Three terminal feet free. With horn, Without horn, Feet solid, Feet latticed, Feet solid, Feet latticed. Last joint rounded, f ^^^.^^ j^^^^^ ^^^^ ^.j^^ ^^^ ^^^^ ^j j^^^^ without a verti- | \ r i cal basal spine -j ,^^^^^ j^^^^^j i^tjjged wings (or rows of (cephahs with ^. . _ /> ^ _ horn). [ ° ' Last joint conical, pointed, with a vertical spine. Three lateral solid ribs (cephalis with basal I an apical horn), 626. Stkhopilium. 627. Artopilium. 628. Pteropilium. 629. SHehocampe. 630. Stichopterium. 631. Podocampe. 632. Stichopodium. 633. Stichopera. 634. Cyrtopera. 635. Artopera. Subfamily 1. Stichopilida, Haeckel, 1881, Prodromus, p. 439. Definition. — P odocampida with the terminal mouth of the shell open (vel Stichocyrtida triradiata aperta). Genus 626. Stichopilium,^ Haeckel, 1881, Prodromus, p. 439. Definition. — S tichopilida (vel Stichocyrtida trii-adiata aperta) with three solid lateral ribs or wings, without terminal feet. Cephalis with a horn. The genus Stichopilium is the most primitive among all Stichocyrtida, and repre- sents perhaps the common ancestral form of this family. The shell is composed of four or more joints (sometimes ten to twelve), has a wide open terminal mouth, and three lateral solid wings or ribs (sometimes a little latticed on the base). Stichopilium may be derived from Tlieopilium or Pterocorys by addition of new terminal joints. Subgenus 1. Triacartus, Haeckel, 1881, Prodromus, p. 437. Definition. — Shell with three annular strictures, and four distinct joints. 1 Stich(ypilium='S.a.t with a row of joints; arixo;, ■xi'Kiou. REPORT ON THE RADIOLARIA, 1437 1 Stichojnlium cortina, n. sp. Shell ovate, with three sharp strictures. Length of the four joints = 2:6:3: 4. Cephalis sub- spherical, with a slender pyramidal horn of twice the lengtL The three edges of the horn are prolonged into three strong divergent ribs, along the three first joints, and into three free conical lateral spines, directed downwards, on the end of the third joint. The fourth joint is sub- cylindrical ; its circular, terminal mouth half as broad as the third joint, which is the broadest. Pores small, regular, hexagonal, with thin bars. JDimcnskms. — Length of the shell (with four joints) 015, breadth 0'08. Length of the single joints, a 0-02, b 0-06, e 0-03, d 0-04. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 2. Stichopilium costatum, n. sp. Shell conical, or nearly pyramidal, with three distinct strictures. Length of the four joints = 3:5:8:4. Cephalis subconical, with a stout pyramidal horn of the same length. Thorax cam- panulate, with six longitudinal ribs, from three of which in the middle arise three horizontal, conical, free spines or wings, about as long as the cephalis. The third large prismatic joint bears twelve parallel ribs, six new ribs being intercalated between the six former. Fourth joint short, cylin- drical, without ribs, the wide open mouth not constricted, nearly as broad as the third joint, which is the broadest. Pores small, irregular, polygonal, or roundish. Dimensions. — Length of the shell (with four joints) 0'2, breadth 012. Length of the single joints, a 0-03, b O'OS, c O'OS, d 0-04. Habitat. — North Pacific, Station 244 (off Japan), depth 2900 fathoms. 3. Stichopilium hicorne, n. sp. (PI. 77, fig. 9). Shell conical, with three slight strictures. Length of the four joints = 4 : 14 : 5 : 3. Cephalis large, conical, with two stout pyramidal, divergent horns of twice the length. From its base (in the middle of the collar stricture) arise three internal, downwardly divergent ribs, which are prolonged on the outside of the upper half of the thorax into three stout, pyramidal, lateral spines (similar to the horns). The fourth joint, with wide open mouth, was the broadest, but not fully developed in the single specimen observed. Pores subregular, hexagonal, with thin bars. Dimensions. — Length of the shell (with four joints) 0'02, breadth 0"09. Length of the single joints, a 0-02, b 0-07, c 0-025, d 0-015. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 4. Stichopilium davisianum, Haeckel. Pterocodon rfaOT'sza«?ilium, but it differs in the fenestration of the three lateral rfbs or wings, which in the latter are solid. The limit between the two genera is often not ' Artopilium =:ho9.i-h.aX; d^oi, ■ni'h.tou. 1440 THE VOYAGE OF H.M.S. CHALLENGER. sharp. Artopilium may be also derived from the three-jointed Dictyoceras by addition of new terminal joints. Subgenus 1. Ti'ictenartus, Haeckel, 1881, Prodromus, p. 437. Definition. — Shell with three annular strictures and four joints. 1. Artopilium elegans, n. sp. (PI. 75, fig. 1). Shell three-sided pyramidal, with three annular strictures. Length of the four joints = 1:2:9:3. Cephalis small, hemispherical, with two large, prismatic, divergent horns of three times the length. The three prominent edges of the second and third joints are finely latticed and dentated, and at the basal end of the third joint are prolonged into three stout, free, pointed, pyramidal, divergent wings, about as long as the horns. The fourth joint is only as long as the second, three-sided prismatic, its wide triangular mouth is armed with six parallel, vertical, slender teeth (two between every three wings). Network very delicate and regular, in the first and second joints with circular, in the third and fourth joints with small hexagonal meshes. Dimensions. — Length of the shell (with four joints) 0-3, breadth of the third joint 0'3, of the fourth 0-2. Length of the single joints, a 0-02, I 0-04, c 018, d 0-06. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. 2. Artopilium longicorne, n. sp. (PL 77, fig. 10). Shell subovate, with three internal annular septa. Length of the four joints = 2:3:2:6. Cephalis hemispherical, with a very large three-sided prismatic horn, nearly as long as the shell. Along the three following joints arise three broad, triangular, latticed wings, about as long as the shell. The fourth joint is the broadest, and twice as broad as the constricted mouth. Pores in the two upper joints regular, circular, in the two lower and the three wings hexagonal. . Dimensions. — Length of the shell (with four joints) 0-13, breadth O'OO. Length of the single joints, a 0-02, h 0-03, c 0-02, d O'OG. Habitat. — Central Pacific, Station 263, depth 2650 fathoms. 3. Artopilium cyrtopterum, n. sp. (PI. 77, fig. 12). Shell subovate, with three sharp strictures. Length of the four joints = 1:2:3:3. Cephalis subspherical, with a stout, pyramidal horn of twice the length. Along the second and third joints arise three broad, triangular, latticed wings, about half as long as the shell. The third joint is the broadest, and twice as broad as the constricted mouth. Pores subregular, circular. Dimensions. — Length of the shell (with four joints) 018, breadth 01. Length of the single joints, a 0-02, b 0-04, c 0-06, d 0-06. Habitat. — North Pacific, Station 253, depth 3125 fathoms. REPORT ON THE RADIOLARIA. 1441 Subgenus 2. Clathropyrgus, Haeckel, 1881, Prodromus, p. 439. Definition. — Shell with four or more annular strictures, and five or more joints. 4. Artopilium trifenestra, n. sp. (PI. 75, fig. 7). Clathropyrgus trifenestra, Haeckel, 1881, Prodromus et Atlas (loc. cit.). Shell tower-shaped, nearly cylindrical, with nine deep strictures. The ten joints are of different lengths and breadths. The third and fourth joints are the longest, twice as long as the first, fifth, sixth, eighth, and ninth joints. The third, seventh, and tenth joints are the broadest, and nearly twice as broad as the second and ninth joints. The mouth of the last joint is dilated. The second joint bears three divergent ribs, and the third joint (as prolongations of these) three broad, triangular, lattice-wings, and between the latter three large, ovate openings or windows, recalling those in Clathrocanium (PI. 64). Cephahs subspherical, with a pyramidal horn of twice the length. Pores subregular, circular, hexagonally framed. Dimensions. — Length of the shell (with ten joints) 0-28, of the first and ninth joints 0-02, of the third and fourth joints 0'04 ; breadth of the third and seventh joints O'OS, of the second and ninth joints 0'04. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 5. Artopilium trigonopterum, n. sp. Shell in the upper half campanulate-conical, in the lower half cylindrical, with seven internal septa. The four middle joints are equal in length, each about twice as long as each of the two first and of tlie two last joints. Cephalis hemispherical, with a conical horn of the same length. Along the first three joints arise three broad, triangular, lattice-wings. Pores small, regular, hexa- gonal, in the wings and the two first joints circular. The five lower joints are of equal breadth. Dimensions. — Length of the sliell (with eight joints) 0"2, breadth 0"1. Length of the four middle joints, each about 0'034, of the two first and the two last, each 0'017. Habitat. — South Pacific, Station 300, depth 1375 fathoms. 6. Artopilium cornutella, n. sp. Shell slenderly conical, without external strictures, but with twelve to fifteen internal annular septa. All thirteen to sixteen joints are nearly equal or shghtly different in length, but increase gradually in breadth. Along the whole shell arise three narrow, divergent lattice-wings, increasing in height towards the wide open mouth. Pores subregular, square, in three to four transverse rows on each joint, half as large in the three wings as in the joints. Cephalis small, subspherical, with a conical horn of twice the length. (In the specimen described the axis of the slender cone was straight, in another incomplete specimen curved ; this may perhaps be a separate species, A rtopilium curvat um.) (ZOOL. CHALL. EXP.— PAET Xli. — 1886.) Erl81 1442 THE VOYAGE OF H.M.S. CHALLENGER. Dimensions. — Length of the shell (with sixteen joints) O'S, basal breadth 012. Length of each single joint (on an average), 0'02. HaUtat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 7. Artopilium stichopterygium, n. sp. (PI. 75, %. 8). Stichopterygiu7n tanypterum, Haeckel, 1881, Prodromus, p. 439, et Atlas. Shell slenderly ovate, subconical, with five deep strictures. The four lower joints are nearly equal in length, each about twice as long as each of the first two joints. The fourth and fifth joints are the broadest. Along the whole shell arise three broad, triangular wings, which envelop the long, slender, pyramidal horn of the cephalis. In the delicate and loose lattice-work of each wing is a longitudinal series of six large, ovate apertures, one on each joint. The small pores of the shell are irregular, polygonal, or roundish. Dimensions. — Length of the shell (with six joints) 017, breadth 0'08. Length of each of the four lower joints 0'03, of each of the two upper joints O'OIS. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 8. Artopilium anomalum, Haeckel. Eucyrtidium anomalum, Haeckel, 1862, Monogr. d. Eadiol., p. 323, Taf. vii. figs. 11-13. Litliocampe ano^nala, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 839. Stichopiterygium anomalum, Haeckel, 1881, Prodromus, p. 439. Shell five-jointed, with four internal septa, of a peculiar, irregular, aud abnormal form. Cephalis small, hemispherical, with an oblique, curved horn. Thorax inflated, campanulate, with three large, latticed, and carinated protuberances. The third joint (the first abdominal joint) nearly as large as the thorax, two to three times as long as the two last joints, the septa of which are connected in a peculiar manner by a common nodal point on one side. Pores subregular, circular. (Compare the detailed description of this remarkable species — perhaps the type of a peculiar genus, Stichopterygium — in my Monograph, he. cit.) Dimensions — Length of the shell (with five joints) 015, breadth 01. Habitat. — Mediterranean (Messina), surface. Geuus 628. Pterop>iliuin,'^ n. gen. Definition. — S t i c h o p i 1 i d a (vel Stichocyrtida triradiata aperta) with three latticed external ribs or M'ings, without terminal feet. No horn upon the cephalis. The genus Pteropilium (confounded by Ehrenberg with Pterocanium) differs from this three-jointed form by addition of new terminal joints. The shell-form is in general the same as in the preceding species, from which it may be derived by phylogenetic loss of the cephalic horn. ' PieropiKum = Winged hat ; •xTi^iv, x/Tkok. REPORT ON THE RADIOLARIA. 1443 1. Pteropilium sphinx, Haeckel. Pterocanium sphinx, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 255, Taf. xvii. fig. 5. Shell slenderly conical, with three slight strictures. Each of the two last joints as long as tlie two first joints togetlier. Cephalis hemispherical. Third joint with three prominent, divergent ribs, which are prolonged along the fourth joint into three latticed, triangular wings, ending in a free, strong, conical spine. Pores subregular, circular, twice as broad in the fourth joint as in the third, and three times as broad as in the second joint. Bimensioiis. — Length of the shell (with four joints) 0"15, of the single joints, a Q-Q2, b 0'03, '■ 0-05, d 0-05 ; breadth of the third joint 0-09, of the fourth joint 0-06. Habitat. — Fossil in Barbados. 2. Pteropilium hombus, Haeckel. Pterocanium hombus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berhn, p. 82, Taf. xvii. fig. 4. Shell broadly conical, with three deep strictures. Length and breadth of the four joints, gradually increasing gi'ving the proportion 2:4:5:6. Cephalis hemispherical, second joint with three prominent ribs, which are prolonged along the third and fourth joints into three slender, triangular pointed wings, with few pores at the base. Pores of the shell subregular, circular. Dimensions. — Length of the .shell (with four joints) 0"17, of the single joints, a 0-02, b 0'04, c 0-05, d 0-06 ; basal breadth Oil. Habitat. — Fossil in Barbados. 3. Pterop>ilium pyramis, n. sp. Shell three-sided, pyramidal, with five deep strictures. Length and breadth of the six joints gradually increasing towards the wide mouth. Cephalis subconical. Along the four first joints arise three slender, divergent ribs, which at the fifth joint become three free, triangular, latticed wings, with long, descending, terminal spines. The sixth joint is free, without wings. Pores irregular, roundish. Dimensions. — Length of the shell (with six joints) 0-2, basal breadth 0'2. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. Genus 629. Stichocampe,^ Haeckel, 1881, Prodromus, p. 439. Definition. — S tichopilida (vel Stichocyrtida triradiata aperta) with three solid lateral ribs or wings, which are prolonged into three solid terminal feet. Cephalis with a horn. 1 SticAocamT^e = CaterpiEar with a row of joints; (tt/xos, x.afivn. 1444 THE VOYAGE OF H.M.S. CHALLENGER. The genus Stichocampe, together wdth the three following genera, represent a peculiar small group among the Stichocyrtida, differing from all other members of this family in the possession of three free terminal feet around the open mouth. In the two genera, Stichocampe and Stichopteriuni, these three feet are the terminal prolonga- tions of three lateral ribs or crests, while in the two genera developed later, Podocainpte and Sticliopodium, the three original ribs are lost, and only the three free feet remain. Stichocampe (the most primitive of these four genera) may be derived from TJieopodium, by addition of new joints. 1. Stichocampe divergens, n. sp. Shell spiny, broadly pyramidal, with six deep strictures. Seven joints gradually increasing in breadth and length, the seventh twice as broad as the fourth. Pores subregular, circular, hexagon- ally framed. The prominent edges of the pyramis are prolonged over the wide mouth into three slender, straight, divergent feet, half as long as the shell. Dimensions. — Length of the shell (with seven joints) 0'3, of the last joint 0'06, of the fourtli 003 ; breadth 0-25. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 2. Stichocampe convei'gens, n. sp. Shell smooth, slenderly pyramidal, with eight distinct strictures. All nine joints nearly equal in length. Pores regular, circular, forming three or four transverse rows in each joint. The smooth edges of the pyramis are prolonged over the wide mouth into three slender, slightly curved, and convergent feet, twice as long as one joint. Dimensions. — Length of the shell (with nine joints) 0'25, of each joint, about 0-35 ; breadth OIL Habitat. — Central Pacific, Station 273, depth 2350 fathoms. Genus 630. Stichopterium,^ Haeckel, 1881, Prodromus, p. 439. Definition. — S tichopilida (vel Stichocyrtida tru-adiata aperta), with three lateral ribs or wings, which are prolonged into three latticed, terminal feet. Cephalis with a horn. The genus Stichopterium has in general the same shell-formation as the nearly allied Stichocampe, but differs from this ancestral form in the fenestration of the three terminal feet. It corresponds, therefore, to Pterocanium among the Tricyrtida. ' Stichopterium = Bow-wing ; BTi'xoi, ■stej/sk. REPORT ON THE EADIOLARIA. 1445 1. Stichopterium pterocanium, ii. sp. Shell campanulate, with three distinct strictures. Length of the four joints = 2:3:4:3. Cephalis suhspherical, with a conical horn of twice the length. Pores regular, hexagonal, with thin bars. From the collar stricture arise three divergent ribs, which in the fourth joint become latticed and prolonged over its mouth into three slender, pyramidal, latticed, divergent feet, nearly as long as the shell. (Similar to Fterocanium bieorne, PI. 73, fig. 5, but with four distinct strictures.) Dimensions. — Length of the shell (with four joints) 012, breadth O'l. Length of the single joints, a 0-02, h 003, c 0-04, d 0-03. Habitat. — South Pacific (off Patagonia), Station 304, surface. 2. Stichopterium virgineiim, n. sp. Shell three-sided, pjTamidal, with four sharp strictures. Length of the five joints = 1:4:3:2:1. Cephalis hemispherical, with a pyramidal horn three times the length. Pores subregular, circular, in the second campanulate joint twice or three times as broad as in the four other joints. From the base of the cephalic horn arise three divergent ribs, which descend over the whole shell, and in the fourth joint become latticed and prolonged over the wide mouth of the fifth joint into three latticed, pyramidal feet, as long as the second joint. (Similar in general form to Plerocanium virgineum, PI. 73, fig. 6.) Dimensions. — Length of the shell (with five joints) 0'22, breadth O'l 6. Length of the single joints, a 0-02, h 0-08, c 0-06, d 0-04, e 0-02. Habitat. — Central Pacific, Station 281, surface. 3. Stichopterium dictyopodium, n. sp. SheU subovate, with five internal annular septa. The third and the fourth joints are about twice as long as the two first and the two last joints. The fifth joint is the broadest. Pores small and numerous, regular, circular. The three first joints are without ribs. From the third stricture arise three divergent, triangular, latticed wings, which descend along the three last joints, and are prolonged over the wide mouth as three slender, fenestrated, divergent feet, two-thirds as long as the shell. Dimensions. — Length of the shell (with six joints) 0'18, breadth 0"12. Length of the two middle joints 0-04, of the four others 0-02 to 0-03. Habitat. — South Pacific, Station 288, surface. Genus 631. Podocampe,^ Haeckel, 1881, Proclromus, p. 439. Definition. — S tichopilida (vel Stichocyrtida triradiata aperta), without lateral ribs or wings, but with three free, solid, terminal feet. Cephalis with a horn. 1 Podocampe = Caterpillar with feet ; aroi/j, xafivti. 1446 THE VOYAGE OF H.M.S. CHALLENGER. The genus Podocampe is next allied to Stichocampe, and has also three solid, free feet around the mouth, but it has lost the three lateral ribs of the latter. It corre- sponds to Podocyrtis among the Tricyrtida, and may be derived from this by addition of new terminal joints. 1. Podocampe tripodiscus, n. sp. Shell ovate, witli three annular septa. The fourth joint is the broadest, and as long as the three other joints together. Cephalis hemispherical, with a pyramidal liorn of twice the length. Mouth constricted, with three convergent, curved, triangular feet, half as long as the last joint. Pores subregular, circular. (Similar to Podocyrtis pcdicellaria, PI. 72, fig. 8, but larger, with more slender feet, and four joints instead of three.) Dimensions. — Length of the shell (with four joints) 0'2, of the last joint 01; breadth 0"12. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 2. Podocampe trictenota, n. sp. (PL 97, fig. 15). Shell slenderly ovate, nearly spindle-shaped, with three annular septa. The third joint is the broadest, somewhat longer than the second and third joints, and three times as long as the hemi- spherical cephalis, which bears a strong pyramidal horn of twice the length. Along the two first joints arise three divergent, dentate crests, each with four to six strong pyramidal teeth. Mouth strongly constricted, only as broad as the cephalis, with three conical, vertical, parallel feet, as long as the cephalis. Pores regular, circular, hexagonally framed. Dimensions. — Length of the shell (with four joints) 0'14, of the third joint 0'06, of the last 004; breadth 0-08. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 3. Podocampe conica, n. sp. Shell conical, with five cUstinct strictures. Six joints gradually increasing in length and breadth. The sixth joint is the broadest, and twice as long as the fifth joint, three times as long as the fourth. Cephalis conical, with a stout, conical horn of the same length. Mouth little con- stricted, with three divergent, conical feet, half as long as the shell. Pores subregular, circular. (Similar to Podocyrtis lithoconus, PI. 72, fig. 3, but with six joints instead of three, and with divergent, slender feet.) Dimensions. — Length of the shell (with six joints) 018, of the last joint 0'06; breadth 012. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 4. Podocampe cornuta, n. sp. Shell slenderly conical, with seven distinct strictures. Eight joints of nearly equal length, gradually increasing in breadth. Along the three last joints arise three prominent crests, which are REPORT ON THE RADIOLARIA. 1447 prolonged over the wide mouth into three divergent, conical feet, half as long as the shell. Cephalis hemispherical, with a conical, slender, curved horn, three times the length. Tores subrernxlar hexagonal. Dimensions. — Length of the shell (with eight joints) OIG, of each single joint (on an average) 0-02; basal breadth O-OV. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. Genus 632. Stichojiodium,^ Haeckel, 1881, Prodromus, p. 439. Definition. — S t i c h o p i 1 i d a (vel Stichocyrtida triradiata aperta) without lateral ribs or wings, but with three free latticed terminal feet. Cephalis with a horn. The genus Stichopodium differs from the preceding genus Podocampe in the fenes- tration of the three free terminal feet. It agrees in this character with the genus Stichopterium, and may be derived either from this by loss of the lateral ribs, or from the three-jointed Pterocanium by addition of new shell -joints. 1. Stichopodixun dictyop)odium, n. sp. (PL 75, fig. 6). Shell subcylindrical, in the upper third conical, with six or seven internal annular septa. All seven or eight joints are about equal in length, except the small hemispherical cephalis, which is scarcely half as long, and bears an oblique, conical horn of the same length. Pores small and numerous, regular, circular, quincuncial. The last joint with wide open mouth, and a peristome of three large, triangular, latticed, shovel-shaped, vertical feet. Dimensions. — Length of the shell (with seven joints) 0'2, breadth OIL Length of each single joint about 0-03, of the feet 0-03. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. Subfamily 2. Stichoperida, Haeckel, Prodromus, p. 439. Definition.- — P odocampida with the terminal mouth of the shell fenestrated (vel Stichocyrtida triradiata clausa). Genus 633. Stichopera,^ Haeckel, 1881, Prodromus, p. 439. Definition. — S tichoperida (vel Stichocyrtida triradiata clausa) with three solid lateral ribs, or three longitudinal combs of spines. Cephalis with a horn. '^ Stichopodium = B,ow-ioot; BTijcos, voi ion. ■ SJic^opera = Row-pouch ; arixo;, ■TrijQot. 1448 THE VOYAGE OF H.M.S. CHALLENGER. The genus Stichopera, and the two following genera, represent the small sulDfamily of Stichoperida, or those triradiate Stichocyrtida in which the terminal mouth is closed by lattice-work. In Stichojyera the three radial appendages are either solid lateral ribs or longitudinal combs of spines ; the closed basal part of the shell is rounded, not pointed. It may be derived either from Stichopilium by closure of the mouth, or from Lithorniihium 'by increase of the number of the joints. Subgenus 1. Stichoperina, Haeckel. Definition. — Shell with three solid radial ribs, or longitudinal dentate crests. 1. Stichopera ovata, n. sp. Shell ovate, with three distinct strictures. Length of the four joints = 2:3:4:6. The fourth joint is the broadest, and twice as long as the second, with hemispherical basal pole. Cephahs hemispherical, with a conical horn of twice the length. Along the second and third joints descend three prominent divergent ribs, which disappear in the middle zone of the fourth joint. Pores regular, circular. Dimensions. — Length of the shell (with four joints) 01.5, breadth 01. Length of the single joint, a 0-02, I O'OS, c 0-04, d 0-06. Halitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Stichopera lagena, n. sp. Shell bottle-shaped, with six sharp strictures ; the upper half is slender, conical, and composed of six joints of nearly equal length, the lower half is formed only by the last subspherical joint. Cephalis subspherical, with a pyramidal horn of the same length. From its base arise three divergent ribs, which attain the greatest height in the fourth joint, and disappear in the sixth joint. (Similar to Stichophcena ritteria7ia, PI. 75, fig. 12, but only with three ribs and seven joints.) Pores regular, hexagonal. Dimensions. — Length of the shell (with seven joints) 0'25. Length of each joint 0"02 to 0'025, of the last joint 012 ; breadth 014. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 3. Stichopera serrata, n. sp. Shell bottle-shaped, with eight deep strictures. The first eight joints are little different in length, and form together a slender cone, while the last joint is four times as long (half as long as this cone), and subspherical. Cephalis conical, with a slender, prismatic horn of three times the length. Along the whole shell arise three divergent, serrate ribs, which disappear towards the hemispherical, basal pole. Pores subregular, hexagonal. REPORT ON THE RADIOLARIA. 1449 Dimensions. — Length of the shell (with nine joints) 0'21, breadth 0"08 ; length of each joint 0-016 to 0-019, of the last joint 0-07. Habitat. — Western Tropical Pacific, Station 224, depth 1850 fathoms. Subgenus 2. Sticholagena, Haeckel. Definition. — Shell mth three radial combs or longitudinal rows of isolated spines (instead of the three radial ribs). 4. Stichopera pectinata, n. sp. (PI. 75, fig. 11). Shell club-shaped, with nine sharp strictures. The nine upper joints increase gradually in length and breadth, and are together three times as long as the inflated, inversely campanulate and rounded last joint. Each joint (excepting the first and the last) bears three thin, bristle-shaped spines, which are directed obliquely upwards. Cephalis subspherical, with a slender, conical horn of twice the length. Pores subregular, in the upper half circular, in the lower hexagonal. Dimensions. — Length of the shell (with ten joints) 0-22, breadth 0-09 ; length of the eighth and ninth joints 0-02, of the last jomt O'OTo. Habitat. — North Pacific, Station 241, depth 2300 fathoms. 5. Stichopera clavata, n. sp. Shell club-shaped, with eight sharp strictures, very similar in form and structure to that of the preceding species, but differing from it in the club-like form of the inflated last joint, which is nearly half as long as the shell ; its lower half is broader than the upper (the reverse being the case in the preceding species). The lateral spines of the three combs are not directed upwards, but downwards. Cephahs with a curved, conical horn of the same length. Dimensions. — Length of the shell (with nine joints) 0-2, breadth 0-08 ; length of the eighth joint 0-02, of the last joint 0-09. Habitat. — South Pacific, Station 298, depth 2225 fathoms. 6. Stichopera verticiUata, n. sp. Shell club-shaped, with ten sharp strictures, similar in form and structure to that of the two preceding species, but differing from them in the ovate form of the slender last joint, which is one- third as long as the whole shell, and five times as long as the preceding joint. The lateral spines of the three combs are directed nearly horizontally, and are much more nimierous, each joint (excepting the first and last) bears six to twelve spines (two, three, or four in each radius). They form together about thirty horizontal verticils, each with three spines. Cephalis with a curved, conical horn of three times the length. (ZOOL. CHALL. EXP. — PART XL. — 1886.) Kr 182 1450 THE VOYAGE OF H.M.S. CHALLENGER. Dimensions. — Length of the shell (with eleven joints) 0-28, breadth 0-09 ; length of the tenth joint 0'02, of the last joint 0"1. Hahitat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 634. Cyrtopera} Haeckel, 1881, Prodromus, p. 439. Definition. — S tichoperida (vel Stichocyrtida triradiata clausa) with three latticed lateral wings, or three longitudinal rows of lattice-wings. Cephalis with a horn. The genus Cyrtopera differs from tlie preceding Stichopera in the fenestration of the three lateral wings, and bears therefore to it the same relation that Sethornithium exhibits to Lithornithium among the Tricyrtida. Subgenus 1. Artopera, Haeckel, 1881, Prodi-omus, p. 438. Definition. — Shell with three annular strictures and four joints. 1. Cyrtopera thoracoptera, n. sp. (PI. 75, fig. 3). Artopera tlwracoptei-a, Haeckel, 1881, Prodromus et Atlas {loc eit.). Shell inflated, with three very deep strictures. Length of the four joints = 2:7:8:6. Cephalis hemispherical, with a slender, prismatic horn, half as long as the shell. Thorax subspherical, in its middle third with three latticed, triangular wings of half the length. Abdomen with inflated third, and inversely hemispherical fourth joint ; the third is the broadest. Pores subregular, hexagonal, with thin bars. Dimensions. — Length of the shell (with four joints) 0'23. Breadth of the third (broadest) joint 013. Length of the single joints, a 0'02, h 0-07, c 0-08, d 0-06. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 2. Cyrtopera ornithoptera, n. sp. Shell broadly ovate, with three slight strictures. Length of the four joints = 1:2:3:4. Cephalis hemispherical, with a slender, pyramidal horn of three times the length. Along the second and third joints arise with broad base three latticed, triangiJar wings, nearly as long as the whole shell. Abdomen inflated. The fourth joint is the broadest and longest, with hemispherical basal pole. Pores subregular, hexagonal. (Similar to Artopilium longicornc, PI. 77, fig. 10, but with more closely reticulated network, and perfectly closed mouth.) Dimensions. — Length of the shell (with four joints) 0'2. Breadth of the fourth (broadest) joint 014. Length of the single joints, a 0-02, b 0-04, c 0-06, d 0-08. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. ' Cyrtopera = Basket-poucli ; xi/^ro;, 9r^j«. REPORT ON THE RADIOLARIA. 1451 3. Cyrtopera gasteroptera, n. sp. Shell slenderly ovate, with three distinct strictures. Length of the four joints = 2 : G : 7 : 6. Cephalis subspherieal, with a stout pyramidal horn of the same length. The three following joints have nearly equal length ; the third is the broadest. The thorax exhibits three divergent solid ribs ; as prolongations of these, three descending latticed wings, of about the same length, arise from the third joint, with broad triangular base. The fourth joint is inversely conical, blunt. Pores irregular, roundish. (Similar to Mexalatractus fusiformis, PI. 68, fig. 13, but with three wings and four joints.) DimensioTis. — Length of the shell (with four joints) 0'21. Breadth of the third (broadest) joint 0-11. Length of the single joints, a 0-02, b 006, c 007, d 0-06. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. Subgenus 2. Cyrtolagena, Haeckcl, 1879, Atlas (PI. 75). Definition. — Shell with four or more annular strictures, and five or more joints. 4. Cyrtopera laguncula, n. .sp. (PL 75, fig. 10). Cyrtolagena laguncula, Haeckel, 1879, Manuscript et Atlas (lor. cit.). Shell bottle-shaped, with seven sharp strictures ; the upper part is slender, conical, composed of seven joints of nearly equal length ; the lower part is only formed by the spherical last joint. Cephalis subspherieal, with a slender curved horn of three times the length. Along the whole shell arise three longitudinal combs or rows of ascending spines (three on each joint, fifteen on the last). These are connected by three divergent longitudinal rods, so that three elegant fenestrated ribs are formed (each rib with one series of large square meshes). Pores in the seven upper joints regular, circular, in the last polygonal, irregular and larger. Diviensions. — Length of the shell (with eight joints) 017, of the last joint 0'08 ; breadth O^OS. Habitat. — South Pacific, Station 298, depth 2225 fathoms. 5. Cyrtopera lagenella, n. sp. Shell bottle-shaped, with twelve sharp strictures, very similar in form and structure to the pre- ceding species; but instead of the three simple fenestrated ribs there arise here, along the shell, three series of short, triangular, latticed wings. The four first and the last joints are without wings. The hemispherical cephalis bears a curved conical horn, as long as the subspherieal last joint. The twelve joints of the upper conical part are nearly equal in length, with regular, small, hexagonal pores. The last inflated joint is one-third as long as the shell, and has larger, irregular, polygonal pores. Dimensions. — Length of the shell (with thirteen joints) 0'25, of the last joint 0'08 ; breadth O'l. Habitat. — South Pacific, Station 300, depth 1375 fathoms. 1452 THE VOYAGE OF H.M.S. CHALLENGER. Genus 635. Artopera,^ Haeckel, 1881, Prodromus, p. 438. Definition. — S t i c h o p e r i d a witli three solid lateral ribs or wings, and with a vertical basal spine on the end of the pointed last joint. Cephalis with a horn. The genus Artopera differs from its ancestral genus, Stichopera, in the development of a vertical terminal spine on the end of the last joint, and bears therefore to it the same relation that Rhopalatractus exhibits to Rhopalocanium among the Tricyrtida. 1. Artopera loxia, Haeckel. Lithornithium loxia, Ehrenberg, 1854, Mikrogeol., Taf. xxsvi. fig. 8; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 78, Taf. iv. fig. 8. Shell spindle-shaped, with three deep strictures. Length of the four joints = 2:5:5:4. Cephalis subspherical, hyaline, without pores, with a thick conical horn of the same length. From the two following joints, which are nearly equal in size and of eampanulate form, arise, with broad base, three divergent, slender, triangular wings. The fourth joint is smaller, inversely conical, and bears on the basal pole a strong, three-sided pyramidal, vertical spine, half as long as the shell. Pores subregular, circular. Dimensions. — Length of the shell (with four joints) 0'18, breadth 0'07. Length of the single joints, a 0-02, h 0-055, c 0-055, d 0-05. HaMtat. — Fossil in Barbados. 2. Artopera motacilla, n. sp. Shell spindle-shaped, with three distinct strictiires. Length of the four joints = 1:2:3:2. Cephahs subspherical, with a conical horn of twice the length. From the second jomt arise three longitudinal, smooth, divergent ribs, which are prolonged over the third joint, and terminate at the third stricture in three short, conical teeth. The fourth is inversely conical, and bears on the basal pole a strong, vertical, cylindrical spine, nearly half as long as the shell. Pores subregular, circular, hexagonaUy framed. (Similar to Rhopalatractus pentacanthus, PI. 68, fig. 11, but differing in the presence of three sharp strictures, and a large, conical, basal joint). Dimensions. — Length of the shell (with four joints) O'lS. Breadth of third (broadest) joint O'OO. Length of the single joint, a 0-02, h 0-04, c 0-06, d 0-04. Habitat. — Western Tropical Pacific (Phihppine Sea), Station 198, depth 2150 fathoms. 3. Artopera fusiformis, n. sp. Shell spindle-shaped, with three distinct strictures. Length of the four joints = 2:3:5:5. Cephalis conical, with a strong, conical horn of the same length. Along the three first joints arise ' .Artopera = Bread-pouch; aigroj, 9r^;«. REPORT ON THE RADIOLARIA. 1453 three divergent, irregularly dentate ribs, which at the second joint bear stronger, pyramidal teeth, also at the thml stricture a strong, terminal tooth. Fourth joint without ribs, inversely conical, with a strong, conical, terminal spine of half the length on the basal pole. Pores subregular, circular, double-edged. Dimensions. — Length of the shell (with four joints) 0'15. Breadth of the third (broadest) joint 0-08. Length of the single joint, a 0-02, h O'O.S, c 0-05, d 0-05. Hahitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. Family LXIX. Phormocampida, u. fam. Artophormida et Artophsenida, Stichophormida et Stichophsenida, Haeckel, 1881, Prodromus, pp. 438, 439. Definition, — S tiehocyrtida multiradiata. (Cyrtoidea with an aunulated shell, divided by three or more transverse constrictions into four or more aunitlar joints, with numerous, four to nine or more, radial apophyses.) The family Phormocampida comprises those Cyrtoidea in which the lattice-shell is composed of numerous (four to eight or more) annular joints, and bears numerous (four to eight or more) radial apo2>hyses. We divide it into two subfamilies, differing in the shape of the terminal mouth. This is a simple wide opening in the Stichophormida (and the united Artophormida), closed by a lattice- plate in the Stichophsenida (and the united Artophaenida). The phylogenetic origin of the Phormocampida ma}'' be found in the Phormocyrtida. Three fossil forms only of Phormocampida were hitherto known, two of which were described by Stohr as Eucyrtidium aciitatum and Lithocampe fimbriata, the third by Ehrenberg as Eucyrtidium harhadense ; the latter belongs to Artophormis, the two former to Cyrtophormis. All the other Phormocampida here described, forming together thirty-one species, are new ; twenty -two of them belong to the Stichophor- mida, and nine to the Stichophteuida. The latter are disposed in two, the former in four genera. The number of the radial apophyses is sometimes six or nine, sometimes twelve or more, usually a multiple of three. They are either lateral ribs or wings (PI. 75, figs. 2, 5, 12), or terminal feet (PL 77, figs. 13 to 18). Usually they are solid, not latticed, and not strongly developed. The majority of Phormocampida have pro- bably been derived from Phormocyrtida by growth of the abdomen, which becomes annulated by transverse constrictions. Some forms, however, may be derived from similar Podocampida, by interpolation of three to six or more secondary apophyses between the three primary or perradial apophyses. 1454 THE VOYAGE OF H.M.S. CHALLENGER. I. Subfamily Stichophormida. Mouth of the terminal joint open, simple. II. Subfamily Stichophsenida. Mouth of the terminal joint closed by a lattice-plate. Syno23sis of the Genera of Phormocampida. Shell conical or pyra- , midal. Mouth wide j open, not constricted. Shell ovate or spindle- shaped. Mouth more or less constricted. Six radial ribs or wings, Nine radial ribs or wings, Lateral ribs prolonged terminal feet, . into the 636. Stichophormis No lateral ribs. Feet minal. free, ter- 637. Plwrmoeampe Lateral ribs prolonged terminal feet, . into the 638. Arfophormis. No lateral ribs. Feet minal. free, ter- 639. Gyrtophormis. 640. Artophsena. 641. Stichoplixna. Subfamily 1. Stichophormida, Haeckel, 1881, Prodromus, p. 439. Definition. — P hormocampida with the terminal mouth of the shell open (vel Stichocjrrtida multiradiata aperta). Genus 636. SticIiophor7nis,^ Haeckel, 1881, Prodromus, p. 439. Definition. — Stichophormida (vel Stichocyrtida multiradiata aperta) with conical or pyramidal shell, bearing in its wall numerous lateral riljs, which are prolonged into terminal feet. Mouth not constricted. The genus Stichophormis and the three following genera represent together the sub- family of Stichophormida, or of those multiradiate Stichocyrtida in which the mouth remains open ; they may be derived therefore either from the Theophormida by in- creasing the number of the shell -joints, or from the Stichopilida by the interpolation of new radial ribs between the three primary ribs. Stichophormis may have been derived in the former way from Theophormis. Subgenus 1. Stichophormium, Haeckel. Definition. — Shell with six prominent longitudinal ribs, which are prolonged into six (sometimes five or seven) divergent free feet over the mouth. 1. Stichophormis pyramidalis, n. sp. Shell slenderly pyramidal, with three annular septa, and six prominent radial ribs, which arise from the collar-septum, and are prolonged on the mouth into si.x free, divergent, pyramidal feet, ' Stichophormis = Row-basket ; ot/xos, hcBna ritteriana, n. sp. (PI. 75, fig- 12). Shell pear-shaped, twice as long as broad, with seven internal annular septa. Tlie upper half is slenderly conical, composed of seven joints of nearly equal length, gradually increasing in breadth. The lower half is formed only by the eighth joint, which is very large, subglobose, inflated, and as long as the seven other joints together. The spherical cephaHs bears a conical horn of the same length. From the thorax arise at equal distances nine radial ribs in the form of thin, triangular lamellae, which attain their greatest height in the sixth joint, and form nine elegant, denticulate crests in the eighth joint. Pores small and numerous, subregular, circular. This beautiful species is dedicated to my honourable friend, Dr. Paul von Eitter, the magnanimous philanthropist and liberal protector of free science, who founded in the University of Jena the first professorial chair of Darwinism and phylogeny. Dimensions. — Length of the shell (with eight joints) 0'24, breadth 0'12. Length of each of the first seven jomts 0"015 ; diameter of the subspherical last joint 0"12. Habitat. — South Pacific, Station 300 (ofT Juan Fernandez), depth 1375 fathoms. 2. StichophoBna darwiniana, n. sp. Shell pear-shaped, twice as long as broad, with six distinct strictures. The last joint is the broadest and twice as long as the sixth, three times as long as each of the five preceding joints. The hemispherical cephalis bears a conical horn of twice the length. From the third joint arise nine radial ribs, which reach the sixth joint, but are not developed in the last hemispherical joint. Pores irregular, roundish. Dimensions. — Length of the shell (with seven joints) 0"2, breadth 0"1. Length of five first joints, each 0-018 to 0-022, of the sixth 0-03, of the seventh joint 0-06. Halitat. — Central Pacific, Station 265, depth 2900 fathoms. 1 Stichophcsna = Row-shell ; inix<"^, (pahix. (ZOOL. CHALL. EXP. — PAKT XL. — 1886.) Er 184 1466 ' THE VOYAGE OF H.M.S. CHALLENGEK. 3. Stichophcena gcetheana, n. sp. Shell ovate, one and a half times as long as broad, rough, with five internal annular septa. The six joints gradually increase in length and breadth. The last joint is the broadest, and half as long as the five others together. The hemispherical cephalis bears a pyramidal horn of twice the length. From the thorax arise nine radial ribs, which attain their greatest height in the fourth joint and reach the fifth joint, but are not developed in the last ovate joint. Pores subregular, circular. Dimensions. — Length of the shell (with six joints) 0-22, breadth 014. Length of the single joints, a 0-02, b 0-025, c 0-03, d 0-035, c 0-04, / 0-7. Hahitat. — Central Pacific, Station 266, depth 2750 fathoms. Subgenus 2. Stichophcenoma, Haeckel. DeJi7iition.— Last joint of the shell pointed, armed with a polar, basal spine, or a bunch of spines. 4. StichopJuena nonaria, n. sp. (PI. 76, fig. 6). Shell nearly spindle-shaped, with five or six distinct strictures. The third joint is the broadest and longest, and twice as long as- the second and the fifth joints. Along the second or third middle joint (beginning from the second or third) descend nine prominent longitudinal ribs. Cephalis hemispherical, with two short, conical, divergent horns. Last joint inversely conical, armed with several strong, conical, divergent spines. Dimensions. — Length of the shell (with seven joints) 0-23, of the third joint 0-05, of the last 0-04; breadth 0-1. Hahitat. — North Pacific, Station 244, depth 2900 fathoms. 5. Stichophcena novena, n. sp. (PL 76, fig. 7). Shell nearly spindle-shaped, with eight or nine deep strictures. The third joint is the broadest, campanulate, in its lower half with nine prominent ribs, which disappear beyond the third stricture. The following joints are alternately longer and shorter, and decrease gradually in breadth. Thorax hemispherical. Cephalis small, hemispherical, with a conical horn of the same length. Last joint also hemispherical, scarcely larger than the cephalis, with a bunch of conical, divergent spines. Dimensions. — Length of the shell (with nine joints) 0-25, of the third joint 0-05, of the last 0*02; breadth 01. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. REPORT ON THE RADlOLARIA. 1467 Family LXX. Lithocampida, n. fam. Artocortda et Artocapdda, Stichocorida et Stichocapsida, Haeckel, 1881, Prodromus, pp. 437-439. Definition. — S t i c b o c y r t i d a eradiata. (C y r t o i d e a with an annulated shell, divided by three or more transverse constrictions into four or more annular joints, without radial apophyses.) The family Lithocampida comprises those Cyrtoidea in which the lattice-shell is composed of numerous (four to eight or more) annular joints, and bears no radial apophyses. It may be divided into two subfamilies, differing in the shape of the terminal mouth. This is a simple wide opening in the Stichocorida (and the united Ai-tocorida), closed by a lattice-plate in the Stichocapsida (and the allied Axtocapsida). The phylogenetic origin of the Lithocampida may be found in the Theoej'rtida. The number of species of Lithocampida is very great, and amounts here to more than one hundred and sixty, whilst the total number of Stichocyrtida is about two hundred and forty. They represent, therefore, two-thirds of the whole group, whilst one-third is composed of the Podocampida and Phormocampida. Ehrenberg has already described between forty and fifty species in his genera JEucyrtidium and Litho- campe; the majority of these were fossils from Barbados. This large number of species may be easdy increased by accurate researches on the great masses of Lithocampida, which are found in the Radiolarian ooze of the Challenger, and as fossils in Barbados. The variety in the number, size, and proportion of the shell-joints and of the lattice-^^ores is very great, and permits us to distinguish a far greater number of species than are here described. Many species are cosmopolitan, and belong to the most common forms of Radiolaria. This large number of species requires to be disposed in different genera, but the distinction of these latter is a rather difficult task, since the exterior of the shell, as well as its internal structure, offers no striking differences (compare Pis. 78 to 80). In my Monograph (1862, pp. .312 to 319) I have already pointed out the difficulty of distinguishing between Lithocampe and Eucyrtidium. The general form of the shell exhibits a continuous series of transformations, from a flat, conical, or nearly discoidal form, through cylindrical to ovate, or spindle-shaped shells, the wide open terminal mouth becoming more or less constricted, and finally (in the Stichocapsida) closed. The absence or presence of an apical horn may further serve for the distinction of genera. A peculiar small group is represented by the Spirocampida [Spirocyrtis, Spirocampe, PL 76, figs. 11 to 17), the transverse latticed girdles separating the single joints, which are usually parallel and horizontal, becoming here partly connected, so that they form a descending spiral. 1468 THE VOYAGE OF H.M.S. CHALLENGER. I. Subfamily Stichocorida. Terminal mouth of the last shell- joint a simple ■wide opening. Synopsis of the Genera of Lithocampida. ' ri ■ A J ( With horn, Conical, gradu- j ' aUy dilated. ( j^^ j,,^^ All annular septa or transverse strictures of the shell separated, parallel, not connected by a spiral line. Shell conical or cylindrical. Mouth of the last joint wide open, not dis- tinctly con- stricted. Conical above, ( J Wi below. ( cylindrical ith horn. Cylindrical or ( With horn, subcylin- < drioal. ( No horn, Shell ovate or spindle-shaped. Mouth of the last joint con- stricted. Cephalis with a horn. Cephalis with- out horn. Last joint tubular. Last joint a long tube. not Cephalis tube. with Cephalis without tube, II. Subfamily Stichocapsida. Terminal mouth closed by a lattice-plate. Annular septa or transverse strictures of the ( With horn, . shell all or partly obliquely descending and -J connected spirally. ( No horn, Last joint rounded, without a vertical basal J ' " ■ I No horn, 642. Lithostrobus. 643. Dictyomitra. 644. Stichocorys. 64-5. Artostrohus. 646. Litlioniitra. 647. Eucyrtidium. 648. Eusyringium. 649. Siphocampe. 650. Lithocampe. 651. Spirocyrtis. 652. Spirocampe. 653. Cyrtocapsa. 654. Stiehoeapsa. Last spine. ^jomt conical, pointed, with a vertical, basal | Cephalis with horn, 655. Artocapsa. Subfamily 1. Stichocorida, Haeckel, 1881, Prodromus, p. 438. Definition. — L ithocampida with the terminal mouth of the shell open (vel Stichocyrtida eradiata aperta). Genus 642. Lithostrobus,^ Biitschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529. Definition. — S tichocorida (vel Stichocyrtida eradiata aperta), with conical shell, gradually dilated towards the wide open mouth. Cephalis with a horn. The genus Lithostrohus is probably the most primitive among the Lithocampida, and comprises those forms of this family in which the slender, conical shell is gradually dilated towards the wide, terminal mouth, each joint being broader than the preceding. ' Lithostrohus = Con& of siles; 7i;'^o;, o-tjo'/Jos. REPORT ON THE RADIOLARIA. 1469 It may be deiived from Tlieoconus by increase in the number of the joints. Some species are distinguished by a curved axis, which gives them a horn-like appearance; these may be separated as a peculiar genus, Covnustrobus. Subgenus 1. Conostrohus, Haeckel. Definition. — Shell regularly conical, with straight axis ; all joints nearly equal in length, gradually increasing in breadth. 1. Lithostrobus monostichus, n. sp. Shell slenderly conical, smooth, with straight axis, and eight to ten deep strictures. All joints nearly of the same length, gradually increasing in breadth ; the eighth joint twice as broad as the fourth. In each joint only a single transverse series of small, circular, regular pores. Hoi'n of the cephalis conical, straight, of twice the length. (Similar to Lithostrobus tetrastichus, PI. 80, fig. 6, but in each joint there is only a single series of pores.) Dimensions. — Length of the shell (with ten joints) 0'2, of each joint 0-02 ; breadth of the fourth joint O'OS, of the eight 006. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 2. Lithostrobus distichus, n. sp. Shell conical, papillate, with straight axis, and four to six deep strictures. All joints nearly of the same length, the fifth twice as broad as the second. In each joint two transverse rows of large, circular pores. Horn of the cephalis stout, straight, conical, of the same length. Dimensions. — Length of the shell (with six joints) 0'18, of each joint 0'03 ; breadth of the second joint 0-04, of the fifth 0-08. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 3. Lithostrobus tristichus, Haeckel. Lithostrolus cuspidatus, Biitschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529. Eucyriidium cuspidatuni, Bailey, 18.56, Amer. Journ. Sci. and Arts, vol. xxii. p. 5, pi. i. fig. 12. Shell slenderly conical, smooth, with straight axis, and eight to ten deep strictures. All joints nearly of the same length, the eighth joint twice as broad as the third. In each joint three trans- verse rows of pores. Horn of the cephaKs bristle-shaped, strongly curved, about as long as the shell. (Ehrenberg confounds this species with Lithostrobus cuspidatus). Dimensions. — Length of the shell (with eight joints) 0-16, of each joint 002 ; breadth of the fourth joint 0-04, of the eighth 0-08. Habitat. — North Pacific, Kamtschatka (Bailey); Station 241, depth 2300 fathoms. 1470 THE VOYAGE OF H.M.S. CHALLENGER. 4. Ldthostrobus tetrastichus, n. sp. (PL 80, fig. 6). Shell slenderly conical, smooth, with straight axis and six to eight deep strictures. All joints nearly of the same length, the eighth joint twice as broad as the second. In each joint four trans- verse rows of regular, circular pores with very thin bars. Horn of the cephalis conical, strong, curved, about as long as two joints. Dimensions. — Length of the shell (with eight jomts) 012, of each joint 0'015 ; breadth of the second joint 0'02, of the eighth 0'04. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 5. Luhostrohus pentastichus, n. sp. Shell slenderly conical, smooth, with straight axis, and six to eight slight strictures. All joints nearly of the same length, the sixth twice as broad as the third. In each joint five transverse rows of small circular pores. Horn of the cephalis pyramidal, of twice the length. (Similar to Eucyrtidi'um cicnkoioskii, PL 80, fig. 9, but regiilarly conical, with all the joints equal in length.) Dimensions. — Length of the shell (with eight joints) 0'2, of each joint 0'025 ; breadth of the third joint 0-04, of the sixth 0-08. Habitat. — South Pacific, Station 298, depth 2225 fathoms. 6. Lithostrohus hexastichus, n. sp. (PL 80, fig. 15). Shell campanulate-conical, smooth, with straight axis, and six to eight slight strictures. All joints nearly of the same length, the sixth joint twice as broad as the second. In each joint six transverse rows of subregular, hexagonal pores, with thin bars. Horn of the cephalis conical, straight, of about the same length. (The specimen figured is a somewhat irregular one ; other specimens found afterwards were perfectly conical and regular, with joints of equal length). Dimensions. — Length of the shell (with six joints) 0'16, of each joint 0'027. ' Habitat. — Central Pacific, Station 270 to 274, depth 2350 to 2925 fathoms. Subgenus 2. Cornustrobus, HaeckeL Definition.~^\\Q\[ horn-shaped, conicaL with curved axis ; all joints nearly equal in length, gradually increasing in breadth. 7. Lithostrohus cyrtoceras, n. sp. (PL 80, fig. 2). Shell horn-shaped, conical, with curved axis, smooth, with six to eight deep strictures. All joints nearly of the same leugth, gradually increasing in breadth ; the sixth joint twice as broad as the second. In each joint about four transverse series of regular circular pores. Horn of the cephalis conical, slightly curved, of the same length. REPORT ON THE RADIOLARIA. 1471 Dimensions. — Length of the curved axis of the shell (with eight joints) 0-24, length of each joint 0-03; breadth of the second joint 0-04, of the sixth 0-08. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 8. Lithostrobus leptoceras, n. sp. Shell horn-shaped, slenderly conical, with curved axis (like a quadrant of a circle), smooth, with twelve to fourteen slight strictures. All joints nearly of the same length, the tenth twice as broad as the second. In each joint only a single transverse row of small circular pores. Horn of the cephalis curved, bristle-shaped, half as long as the shell. DimensfioTis. — Length of the curved axis of the ^hell (with twelve joints) 018, length of each joint 015 ; breadth of the second joint 0"02, of the tenth 0'04. Habitat. — Xorth Pacific, Station 253, depth 3125 fathoms. 9. Lithostrobus caloceras, n. sp. (PI. 80, fig. 4). Shell horn-shaped, conical, with curved axis, smooth, with six to eight deep strictures. All joints nearly of the same length, the sixth twice as broad as the third. On each joint a single circle of very large roundish pores, separated by two to four series of smaller pores. Horn of the cephalis conical, curved, of twice the length. Dimensions — Length of the curved axis of the shell (with six joints) 012, length of each joint 0-02 ; breadth of the third joint 0-04, of the sixth 0-08. Habitat. — South Pacific, Station 297, depth 1775 fathoms. 10. Lithostrobus macroceras, n. sp." Shell horn-shaped, slenderly conical, with curved, nearly semicircular axis, without external strictures, but with twelve to twenty internal septal rings. All joints nearly of the same length, the twelfth twice as broad as the third. On each joint three to four transverse rows of subregular, small, hexagonal pores. Horn of the cephalis conical, curved, of twice the length. Dimensions. — Length of the curved axis of the shell (with sixteen joints) 0'32, length of each joint 0-02 ; breadth of the third joint 0-02, of the twelfth 0-04. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. Subgenus 3. Cyrtostrobus, Haeckel. Definition — Shell conical (often more campanulate or irregular), with straight axis ; joints of different lengths. Cephalis not lobate. 1472 THE VOYAGE OF H.M.S. CHALLENGER. 11. Lithostrohus conulus, n. sj). (PI. 80, fig. l). Shell slenderly conical, smooth, with straight axis, and seven to ten distinct strictures. Joints of different lengths ; the fourth and fifth about twice as long as the preceding and following joints, the former with four to five, the latter with two to three transverse rows of large irregular pores ; the seventh joint twice as broad as the third. Horn of the cephalis short, pyramidal. Dimensions. — Length of the shell (with eight joints) 0-14, length of the fifth joint O'OS ; breadth 0-06. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 12. Lithostrohus picus, Biitschli. Lithostrobus picus, Biitschli, 1882, Zeitschr. f. wiss. ZooL, vol. xxxvi. p. 529. Eucyrtidium picus, Ehrenberg, 1875, Abliandl. d. k. Akad. d. Wiss. Berlin, p. 72, Taf. xi. fig. 1. Shell slenderly conical, smooth, with straight axis, and six to eight slight strictures. Joints of different lengths, the second twice as long as each of the three following, and four times as long as each of the last joints; the sixth joint one and a-half tunes as broad as the second. Small circvdar pores in regular transverse rows; six rows in the first and the second, three rows in the third, fourth, and fifth, a single row in each of the last joints. Horn of the cephalis cylindrical, half as long as the shell. Diinensions. — Length of the shell (with eight joints) 0"12, length of the second joint 0'03 ; breadth 0-04. Habitat. — Fossil in Barbados. 13. Lithostrobus argus, Biitschli. Lithostrolus argus, Biitschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529. Eucyrtidium argus, Ehrenberg, 1875, Abhandl. d. k. Akad. d; Wiss. Berlin, p. 70, Taf. ix. fig. 1. Shell conical, thorny, with straight axis, and five to seven slight strictures. Joints of different lengths, each of the three first twice as long as each of the following. Pores large, roundish, in trans- verse rows ; three rows in the first and the second joints (which in the figure of Ehrenberg are not separated), two rows in the third joint, a single row in each of the following joints. Horn of the cephaUs large, conical, curved, half as long as the shell. Dimensions. — Length of the shell (with seven joints) 0'2, length of the fourth joint (and each following) 0-02 ; breadth 01. Habitat. — Fossil in Barbados. 14. Lithostrohus acuminatus, Haeckel. Eucyrtidium acuviinatum, Bury, 1862, Polycystins of Barbados, pi. i. fig. 1. Shell slenderly conical, smooth, with straight axis, and four to six deep strictures. Joints gradu- ally increasing in length. Pores in regular, transverse rows, commonly three rows in the first, four REPORT ON THE RADIOLARIA. 1473 in the second, five in the third, six in the fourth, seven in the fifth, &c. (sometimes the increase of tlie number is more or less irregular). Horn of the cephalis strong, conical, straight, about as long as the fourth or sixth joint. Dimoisiom. — Length of the shell (with six joints) 0-2 ; length of the fourth joint 0-04, breadth 0-06. Habitat. — P'ossil in Barbados. 15. Lifhostrohus ciispidatus, Haeckel. Eucyrtidium cuspidatum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. ii. fig. 15. Shell, slender, conical, smooth, with straight axis, and ten to twelve distinct strictures. Joints gradually increasing slightly in length, the tenth twice as long as the third. Pores circular, in regular transverse rows ; commonly two rows in the first, three in the second, four in the third, seven in the eighth and following joints. Horn of the cephalis long, bristle-shaped, curved. This species called Eucyrtidium cuspidatum by Ehreuberg, differs from LitJwstrobus tristiclms (compare above), to which Bailey had given the same name. Dimensions. — Length of the shell (with ten jokits) 0-2 ; leng^th of the tenth joint 0-03, breadth 0-06. Rabitat. — Xorth Atlantic (Greenland, Ehrenberg); Station 348, depth 2450 fathoms. 16. Lithostrohus cornutella, Biitsclili. LHhostrohus cornutella, BiitscLli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529. Eucyrtidium cornutella, Ehrenberg, 1872, Abhandl d. k. Akad. d. Wiss. Berlin, p. 291, Taf. ii. fig. 14. Shell slender, conical, smooth, with straight axis, and seven to nine slight strictures. Joints gradually increasing slightly in length, the sixth or seventh about twice as long as the third. Pores circular, in regular transverse rows ; two or three in the three or four first joints, three or four in the following, four or five in the last joints. Horn of the cephalis thin, bristle-shapetl, curved. Dimensions. — Length of the shell (with eight joints) 0"1 ; length of the eighth joint 0"01, breadth 0-04. Hahitat. — Cosmopolitan ; Mediten'anean, Atlantic, Pacific ; many stations, surface. 17. Lithostrohus tornatus, Haeckel. Eucyrtidium tornatum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 292, Taf. is. fig. 20. Shell campanulate-conical, smooth, with straight axis, and four to six deep strictures. Joints broad, gradually increasing in length, the fifth twice as long as the second. Pores small, circular, in regular transverse rows ; in the second and third joints three or four rows, in the fifth seven rows, &c. Horn of the cephalis small, double or forked. (zOOL. CHALL. EXP. — PART XL. — 1886.) Rr 185 1474 THE VOYAGE OF H.M.S. CHALLENGER. Bimemions. — Length of the shell (with five joints) Ol ; length of the fifth joint 0-04, breadth 0-08. Habitat. — Indian Ocean, Zanzibar, depth 2200 fathoms (Pullen). 18. Lithostrohus seriatus, n. sp. (PI. 79, fig. 15). Shell slender, conical, smooth, with straight axis, and four or five deep strictures. Joints little different in length, increasing towards the inflated last joint, which is twice as long as the pre- ceding. On each joint four or five transverse rows of small circular pores. Horn small, bristle- shaped, oblique. This common species is rather variable. Dimensions. — Length of the shell (with five joints) 014 ; length of the fifth joint 0'05, breadth 0-06. Habitat. — Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms, 19. Lithostrohus cornutus, n. sp. (PI. 77, fig. 6). Shell slender, conical, subcampanulate, smooth, with three or four deep strictures. Joints of different lengths, the third and the fourth twice as long as the second, four times as long as the first. Transverse rows of small circular pores ; three in the first joint, five in the second, eight in the third and in the fourth. Horn large, pyramidal, aliout as long as the third joint. Dimensions. — Length of the shell (with four joints) 0'12 ; length of the third joint 0'04, breadth 006. Habitat. — Central Pacific, Station 265 to 268, depth 2700 to 2900 fathoms. 20. Lithostrohus microporus, Butschli. Lithostrohus microporvs, Butschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529. Eucyrtidium microporum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. xi. fig. 20. Shell slender, conical, smooth, very similar to the preceding species, differs mainly in the nioi'e slender form and the smaller pores. The first joint has four, the second eight, the third ten trans- verse rows of pores. Horn conical, as long as the cephalis. The third joint in this and the pre- ceding species is campanulate, and large. Dimensions. — Length of the shell (with four joints) O'll ; length of the third joint O'Oo, breadth 0-04. Habitat. — Fossil in Barbados. 21. Lithostrohus quadratus,n. sp. Shell broad, conical, smooth, with straight axis, and six to eight deep strictures. Joints of different lengths, usually alternately longer and shorter. The seventh joint five times as broad as long, twice as long as the sixth and the fourth ; six transverse rows of pores in the seventh, three REPOET ON THE EADIOLARIA. 1475 in the sixth joint. Horn small, conicnl. This species differs from all others in the subregular square form of the small pores. I)imensio7is. — Length of the shell (with seven joints) 015 ; length of the seventh joint 0-024, breadth 012. EaUtat — Central Pacific, Station 271 to 274, depth 2350 to 2750 fathoms. 22. Litlwstrobus hexagonall'^, n. sp. (PI. 79, fig. 20). Shell broad, conical, smooth, witli straight axis, and five to eight prominent girdles between six and nine constricted broad joints. The first and the third joints are half as long as the second, the fourth, and each of the following joints. The sixth joint is five times as broad as long. Pores sub- regular, hexagonal, in regular transverse rows ; three to four rows in the first and the second joints, six to eight in the third, the fourth, and each following joint. Cephalis with some small spines, and a larger, oblique, curved horn. Dimensions. — Length of the shell (with six joints) 0'2 ; length of the sixth joint 0'04, breadth 0-2. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. Subgenus 4. Botryostrohus, Haeckel. Definition. — Shell conical, with straight axis, joints of different lengths. Cephalis lobate, with some irregular constrictions. (Perhaps derived from B o t r y o d e a ?). 23. Litho.strohus hotryocyrtis, n. sp. (PL 79, figs. 18, 19). Shell slender, conical, smooth, with straight axis, and three deep strictures. Joints of different lengths. The length of the fourth joint equals two-thirds of its breadth, and of the length of the three preceding joints together. Each of the latter bears three transverse rows of small, quadrangular pores, the fourth joint has six rows. The cephalis is irregularly lobate, with four to six prominent lobes, and two small divergent horns (fig. 19). Dimensions. — Length of the shell (with four joints) 01 ; length of the fourth joint 0'04, breadth 0-06. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 24. Lithostrobus Uthobotrys, n. sp. (PI. 79, fig. 17). Shell slender, conical, smooth, with straight axis, and four deep strictures. Joints of different lengths, gradually increasing towards the mouth, the length of the fifth joint equals half its breadth, and one-third of the length of the whole shell. The single joints bear each four or five transverse rows of small, roundish pores. Cephalis irregularly lobate, with four to six prominent lobes, and the same number of small, conical horns. 1476 THE VOYAGE OF H.M.S. CHALLENGER. Dimensions. — Length of the shell (with five joints) 012 ; length of the fifth joint 0-04, breadth 0-08. Halitat — Central Pacific, Station 268, depth 2900 fathoms. Genus 643. Dictyomitra^ Zittel, 1876, Zeitschr. d. deutsch. geol. Gesellsch., p. 80. Definition. — S tichocorida (vel Stichocyrtida eradiata aperta), with conical shell gradually dilated towards the wide open month. Cephalis without horn. The genus Dictyomitra agrees with the preceding Lithostrohus in the slender, conical form of the multiarticulate shell, but differs from it in the absence of a horn on the cephalis ; the horn is here completely lost. Subgenus 1. Dictyoniitrella, Haeckel. Definition. — Shell smooth, with joints nearly equal in length. 1. Dictyomitra articidata, Haeckel. Eucyrtidium articulatum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xi. figs. 2, 3. Shell slender, conical, smooth, with six to eight deep strictures. All joints nearly equal in length, gradually increasing in breadth, the eighth four times as broad as long, and twice as broad as the fourth joint. In each joint three to four transverse series of small, regular, circular pores. Dimensions. — Length of the shell (with eight joints) 012, of each joint 0-015 ; breadth of the fourth joint 0-04, of the eighth joint 0-08. Habitat. — Fossil in Barbados. 2. Dictyomitra macilenta, Haeckel. Eucyrtidium. macilentum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. vii. fig. 15. Shell slender, conical, smooth, with five to seven deep strictures. All joints nearly equal in length, gradually increasing in breadth, the sixth joint three times as broad as long, and twice as broad as the second. In each joint only two transverse series of small, regular, circular pores. Dimensions. — Length of the shell (with seven joints) 0'08, of each joint 0-012 ; breadth of the sixth joint 0-036, of the second 0018. Habitat. — Western Tropical Pacific, Stations 200 to 225, in various depths. ' -Diic(i/omie clava, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. iv. fig. 2. Shell smooth, club-shaped, or slenderly ovate, with five internal septal rings. Six joints of very different lengths = 5 : 2 : 3 : 4 : 5 : 18. The sixth joint is the broadest, and as long as the five others together. Pores small, circular, in the basal half of the last joint irregular and larger. Constricted mouth as broad as the subspherical, hyaline cephalis. Dimensions. — Length of the shell (with .six joints) 0-15. Length of the single joints, a 0-02, b 0-011, c 0-013, d 0-016, c 0-02,/ 0-07. Habitat. — Fossil in Barbados. 19. Lithocampe hexacola, n. sp. (PL 79, fig. 7). Shell smooth, nearly spindle-shaped, without external strictures, but with five internal septal rings. Six joints of different lengths = 4:8:5:5:5:10. The fourth joint is the broadest, and four times as broad as the constricted mouth. Pores subregular hexagonal, or irregular polygonal, with thin bars. Dimensions. — Length of the shell (with six joints) 0-18, greatest breadth 0-09. Length of the six joints, a 0-02, b 0-04, c, d, and c each 0-025, / 0-05. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 1508 THE VOYAGE OF H.M.S. CHALLENGER. 20. Lithocampe heptacola, n. sp. (PI. 79, fig. 8). Shell smooth, subcylindrical, constricted at both poles, with six distinct strictures. Seven joints of different lengths, the five abdominal joints neatly equal, each half as long as the hemi- spherical, vaulted thorax, and twice as long as the subspherical, small cephalis. Mouth constricted, with a short, tubular, hyaline peristome (like an eighth joint without pores), about one-third as broad as each of the four middle joints. Pores suliregular hexagonal, or irregular polygonal, with thin bars. Dimensions.— Length of the shell (with seven joints) 0-24, greatest breadth 0-09. Length of the cephalis 0-02, thorax 0-06, each of the four following joints 0-03, of the last joint 0-04. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 21. Lithocampe octocola, n. sp. (PI. 79, fig. 6). Shell smooth, subcylindrical, thick-walled, constricted at both poles, without distinct, external strictures, but with seven internal septal rings. Eight joints of different lengths ; four joints (the second to the fifth) being about twice as long as the four others (the first and the three last). The constricted mouth only one-third as broad as the four middle joints. Pores small and numerous, subregular, circular. Dimensions. — Length of the shell (with eight joints) 0'19, breadth 0'09. Length of the second to the fifth joints, each O'OS ; length of the four other joints, each about 0'016. Habitat.- — Central Pacific, Station 274, depth 2750 fathoms. 22. Lithocampe polycola, n. sp. Shell smooth, subcylindrical, constricted at both poles, with twelve to fifteen distinct strictures. Fourteen to sixteen joints of different lengths. Cephalis flat, cap-shaped, hyaline, without pores. Thorax nearly hemispherical, with three transverse rows of small circular pores. Each following joint (each abdominal joint) only with a single row of small pores. The constricted mouth of the last joint only one-third as broad as the middle part of the shell. (Very similar to Lithomitra eruca, PI. 79, fig. 3.) Dimensions.- — -Length of the sliell (with sixteen joints) 0'3, breadth 0'08. Length of the cephalis 0'02, thorax 0*06, each of the following joints 0'015, last joint 0'025. Habitat. — Tropical Pacific, Station 224, depth 1850 fathoms. Genus 651. Sp>irocyrtis^ Haeckel, 1881, Prodromus, p. 438. Definition. — S t i c h o c o r i d a (vel Stichocyrtida eradiata aperta) with spirally- arranged constrictions on the shell. Cephalis with a horn. The genus Spirocyrtis and the following closely allied genus Spirocampe difi"er from the other Stichocorida (and also from nearly all C y r t o i d e a) in a very remarkable ^ iSpiroci/riw = Spiral basket ; aiiUa, kv^ti';. REPORT ON THE RADIOLARIA. 1509 character. The anniUar constrictions of the multiartieulatc shell and the corresponding internal annular septa are here not separated, and do not lie in parallel, transverse planes (as usually happens), but they are all or partly connected in the form of an ascending spiral, so that the joints are not perfectly separated. An' ii-regularity or asymmetry of growth on the different sides of the shell is probably the cause of this strange, spiral structure. Subgenus 1. Spirocyrtidium, Haeckel. Definition. — Shell conical, gradually dilating towards the wide open terminal mouth. 1. Spirocyrtis scalaris, n. sp. (PI. 76, fig. 14). Shell conical, gradually dilating towards the wide open mouth, with ten to twelve spiral convolutions, which correspond to the same number of short and broad chambers or joints, gradually increasing in breadth ; all joints form together a spirally winding staircase. The length or height of the single joints or stairs is about equal, and each bears four or five transverse rows of small, square pores. Cephalis fiat, cap-shai3ed, with two or three short divergent horns. Dimensions. — Length of the shell (with ten joints or turnings) 0'16, length of each joint (on an average) 0"016 ; breadth of the third joint 0'04, of the fifth joint 0'07, of the tenth joint 01. Habitat. — Central Pacific, Stations 271 to 274, depth 2350 to 2750 fathoms. 2. Spirocyrtis cornutella, u. sp. (PL 76, fig. 13). Shell conical, gradually dilating towards the wide mouth, similar to the preceding, but differing in the curved axis, and the broader and shorter joints, each of which bears only two or three transverse rows of square pores. The turnings of the staircase are not so sharp, nor so distinct, as in the preceding species. Cephabs with a single short horn. Dimensions. — Length of the shell (with eight joints) 01 ; breadth of the fourth joint 0'05, of the eighth joint O'OS. Habitat. — Central Pacific, Station 270, depth 2925 fathoms. Subgenus 2. Spirocyrtoma, Haeckel. Definition. — SheU ovate, or nearly spindle-shaped, more or less tapering towards the narrower, somewhat constricted mouth. 3. Spirocyrtis holospira, n. sp. (PL 76, fig. 16). Shell subovate, twice as long as broad, without external strictures, but with an internal regularly descending spiral septum, which separates seven to nine broad joints of nearly equal lengths ; the 1510 THE VOYAGE OF H.M.S. CHALLENGER. first and second joints together are conical, and about as long as each of the following joints. Cephalis small, hemispherical, with a thick pyramidal horn of the same length. The fifth joint is the broadest, the truncate mouth is slightly constricted (in the specimen figured it is broken off). Pores regular, circular, quincuncial. Dimensions. — Length of the shell (with eight joints) 0'2, breadth O'l ; length of each joint, about 0-03. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 4. Spirocyrtis hemispira, n. sp. Shell slender, nearly spindle-shaped, three times as long as broad, without external strictures, but with ten to eleven internal septa. The five or six upper of these are perfectly separate, com- plete parallel rings ; the five or six lower are spirally connected. The eleven or twelve joints gradually taper in length and breadth, from the broadest middle towards the two constricted ends of the sheU. The middle (fifth or sixth) joint is the broadest, and is three to four times as broad as the constricted mouth. Cephalis small, hemispherical, with a conical horn of the same length. Pores regular, circular, hexagonally framed. Dimensions. — Length of the shell (with twelve joints) 0"25, breadth 0"09 ; length of the middle joint 0-03. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 5. Spirocyrtis merospira, n. sp. (PI. 76, fig. 15). Shell ovate, with six to eight slight strictures, twice as long as broad. The three or four upper joints are perfectly separated by annular septa, the three or four lower joints connected by an internal spiral septum. The spiral line is often more or less irregular or interrupted (as is also the case ill the specimen figured). Mouth rather wide. Pores small, subregular, circular. A rather variable species. Dimensions. — Length of the shell (with eight joints) 0'2, breadth O'l. Habitat. — Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms. 6. Sjnrocyrtis diplospira, n. sp. (PI. 76, fig. 17). SheU slender, ovate, with seven to eight slight strictures. All eight or nine joints are con- nected by an internal double spiral septum, the first spiral beginning from the ventral side, the second from the dorsal side of the coUar stricture. Length and breadth of the single joints rather variable and irregular ; the broadest joint is commonly the fifth. Mouth more or less con- stricted. Pores subregular, circular. This remarkable species differs from all other C y r t o i d e a by the double spiral septum of the joints. Dimensions. — Length of the shell (with eight joints) 0-2, breadth 0-1. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. REPORT ON THE RADIOLARIA. 1511 Genus 652. Spirocampe,'^ Haeckel, 1881, Prodromus, p. 438. Definition. — S tichocorida (vel Stichocyrtida eradiata aperta) with spirally arranged constrictions on the shell. Cephalis without horn. The genus Spirocampe has the same peculiar spiral structure of the shell as the pre- ceding Spirocyrtis, and differs from it only in the absence of a cephalic horn. It exhibits, therefore, the same relation to the latter as the similar Lithocampe bears to Uiicyrtidium. 1. Spirocampe callispira, n. sp. (PI. 76, fig. 11). Shell ovate, smooth, with six joints, connected in the form of a complete winding staircase. All the windings are nearly at equal distances ; each bears one row of large roundish pores, enclosed by two rows of smaller pores. Cephalis hemispherical, of about the same breadth as the constricted, short tubular mouth. Dimensions. — Length of the sheU (with six joints) 0-15, breadth 009 ; mouth 0'03 diameter. Habitat. — Central Pacific, Station 270, depth 2925 fathoms. 2. Spirocampe allospira, n. sp. (PL 76, fig. 12). SheU subcylindrical, or nearly spindle-shaped, smooth, very tliick-walled, with eight joints alternately longer and shorter, and connected in the form of an irregular spiral. The distance between the windings is very variable. Pores small, regular, circular. Cephalis hemispherical, of about the same size as the short tubular mouth. Dimensions. — Length of the sheU (with eight joints) 0'2, breadth 0'08 ; mouth 0'03 diameter. Habitat. — Central Pacific, Station 273, depth 2350 fathoms. 3. Spirocampe poly spira, n. sp. Shell cyhndrical, rough, with twelve joints nearly equal in length, connected in the form of a regular, complete spiral. AU windings are at the same distance. Pores regular, circular, three rows on each turning. Cephalis flat, cap-shaped, half as broad as the slightly constricted, not tubular mouth. Dimensions. — Length of the shell (with twelve joints) 0'24, breadth 0'07 ; mouth O'Oo diameter. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Subfamdy 2. Stichocapsida, Haeckel, 1881, Prodromus, p. 439. Definition. — L ithocampida with the terminal mouth of the shell fenestrated (vel Stichocyrtida eradiata clausa). ' S;;irocam2Je = Spiral caterpillar ; airtl^tt., y.uffjT/i. 1512 THE VOYAGE OF H.M.S. CHALLENGER. Genus 653. Cyrtocapsa,^ Haeckel, 1881,'Prodromus, p. 439. Definition. — S t i c h o c a p s i d a (vel Stichocyrticla eradiata clausa) -wdth an apical horn on the cephalis, without basal terminal spine. The genus Cyrtocapsa and the two following genera represent together the small sub- family of Stiehocapsida, or of those C y r t o i d e a in which the many-jointed shell bears no radial appendages, and the terminal mouth is closed by a lattice-plate. They have been derived from the Stiehocorida by development of such a closing plate. Cyrtocap>sa bears an apical horn on the cephalis, and may be derived therefore directly from Eucyrtidium. Subgenus 1. Cyrtocapsella, Haeckel. Definition. — Shell with three annular strictures (or internal septa) and four distinct joints. 1. Cyrtocapsa tetrapera, n. sp. (PI. 78, fig. 5). Shell rough, pear-shaped, with three deep strictures. The three first joints are of equal lengths, and each half as long as the hemispherical fourth joint. Cephalis subspherical, with an oblique conical horn of the same length. The third joint is the broadest, three times as broad as long. Pores regular, circular. Dimensions. — Length of the shell (with four joints) 015, breadth 0'09 ; length of each of the three first joints O'Oo, of the last Q-OG. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 2. Cyrtocapsa comjxicta, n. sp. (PL 77, fig. 8). Eiicyrtidium compactum, Haeckel, 1878, Atlas, loc. cit. Shell rough, pear-shaped, with three slight strictures. The hemispherical cephalis bears a thick pyramidal spine of the same length, and is half as long as the second and the third joints, one- third as long as the hemispherical fourth joint. The third joint is the broadest, three times as broad as long. Pores subregidar, circular. In the centre of the basal pole is one larger pore, the remnant of the constricted mouth of Eucyrtidium. Dinunsions. — Length of the shell (with four joints) 0"16, breadth 0'12. Length of the single joints, a 0-02, h 0-04, c 0-04, d 006. Habitat. — Western Tropical Pacific, Station 206, depth 2100 fathoms. ^ C2/rtocapsa= Basket-capsule ; xi/jto'j, xav/^a. EEPORT ON THE RADIOLARIA. 1513 3. Cyrtocapsa injiata, n. sp. Shell spiny, pear-shaped, with three deep strictures. The inflated third joint is twice as long as the second and fourth joints, and three times as long as the hemispherical cephalis, which bears a large conical horn of three times the length. Fourth joint flat, vaulted, inversely cap-shaped. The third joint is the broadest, being twice as broad as long. Pores regular, circular, double-contoured. Dimensions. — Length of the shell 014, breadth Oil. Length of the single joints, a 0-02, h 0 03, c 0-06, d 0-03. Habitat— YioTih Pacific, Station 244, depth 2900 fathoms. 4. Cyrtocapsa pyrum, n. sp. (PL 78, fig. 8). Shell thorny, pear-shaped, without external strictures, but with three internal annular septa. Length of the four joints = 2:5:6:7. The fourth joint is the broadest, being about twice as broad as long, and hemispherical. The small subspherical cephalis bears a stout conical horn of the same length. Pores large, regular, circular. Bvjncnsions. — Length of the sheU (with four joints) 0'2, breadth 012. Length of the single joints, a 0-02, b 0-05, c 0-06, d O'OV. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 5. Cyrtocapsa cornuta, n. sp. (PL 78, fig. 9). Shell rough, very thick-walled, nearly pear-shaped, with three annular strictures ; the second of which is very sharp, the first and third slight. Length of the four joints = 3:4:5:6. The third joint is the broadest, being about twice as broad as long ; the fourth joint is hemispherical. CephaUs subspherical, with a large, conical, curved horn of- twice the length. Pores regular, circular, hexa- gonaUy framed. Dimensions. — Length of the shell (with four joints) 018, breadth 012. Length of the single joints, a O'OS, b 0-04, c 0-05, d 0-06. Habitat.- — Central Pacific, Station 272, depth 2G00 fathoms. 6. Cyrtocapsa diploconus, n. sp. (PL 78, fig. 6). Shell rough, doubly conical, with three annular septa. Length of the four joints = 3:4:4:8. The third joint is the broadest, two and a half times as broad as long ; the fourth is inversely conical, acute. Cephalis hemispherical, with a pyramidal horn of the same length. Pores irregular, roundish. Dimensions. — Length of the shell (with four joints) 019, breadth 01. Length of the single joints, a 0-03, h 0-04, c 0-04, d O'OS. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. (ZOOL. CHALL. EXP. PART XL. — 1886.) Er 190 1514 THE VOYAGE OF H.M.S. CHALLENGER. 7. Cyrtocapsa fusulus, n. sp. (PI. 78, fig. 7). Shell smooth, spindle-shaped, with three distinct strictures. Length of the four joints = 1:1:4:3. The third joint is the broadest, somewhat longer than broad. The fourth joint is inversely conical. CephaUs hemispherical, with a coronal of large, ovate pores, and a pyramidal, sulcate, oblique horn of twice the length. Pores regular, circular. Dimensions. — Length of the shell (with four joints) 018, breadth 0-07. Length of the single joints, a 0-02, I 0-02, c 0-08, d 0-06. Habitat. — South Pacific, Station 295, depth 1500 fathoms. Subgenus 2. Cyrtocajjsoma, Haeckel. Definition. — Shell with four or more annular septa, and five or more joints. 8. Cyrtocapsa incrassata, Haeckel. Eucyrtidium incrassatum, Stohr, 1880, Palaeontogr., vol. xxvi. p. 105, Taf. iv. fig. 9. Shell rough, spindle-shaped, with four annular septa. Length of the five joints = 2:3:4:4:4. The third joint is the broadest, nearly three times as broad as long. The fourth joint is inversely conical, acute. Cephalis small, spherical, with two short, conical, divergent horns. Pores small, regular, circular. Dimensions. — Length of the shell (with five joints) 017, breadth Oil. Length of the single joints, a O'Olo, h 0-035, c 0-04, d 0-04, c 0-04. Habitat. — Fossil in Tertiary rocks of Sicily, Grotte. 9. Cyrtocapsa costata, n. .sp. Shell smooth, spindle-shaped, twice as long as broad, with nimierous longitudinal ribs, and four annular septa. Length of the five joints = 1:4:3:2:8. The third joint is the broadest. Fourth joint inversely conical, acute. Cephahs small, hemispherical, with a small conical horn. Pores regular, circular. Dimensions. — Length of the shell (with five joints) 018, breadth O'OO. Length of the single jomts, a 0-01, b 0-04, c 0-03, d 0-02, e 0-08. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 10. Cyrtocapsa colatractus, n. sp. Shell smooth, spindle-shaped, with eight internal annular septa (without external stricture). All nine joints are nearly equal in length, the first somewhat shorter, the last longer. The fourth joint is the broadest, four times as broad as long. Last joint inversely conical, blunt. Cephalis subspherical, with a conical horn of the same length. Pores small and numerous, regular, circular. REPORT ON THE RADIOLARIA. 1515 DimcTisions. — Length of the shell (with nine joints) 0'22, brccodth 01 ; length of the cephalis 0-015, of the last joint, 0-03, of each of the seven other joints, 0-022 to 0-028. HaUtat. — Central Pacific, Station 271, depth 2425 fathoms. 11. Cyrtocapsa chrysalidium, n. sp. (PI. 76, fig. 9). Shell rough, nearly spindle-shaped, with seven distinct strictures. Length of the eight joints = •4:6:11:8:5:5:4:3. The third and fourth joints are the broadest. The last joint is small, inversely cap-shaped. Cephalis subspherical, with an oblique, dentate horn of the same length. Pores very numerous, sulsregular, circular. Dimensions. — Length of the shell (with eight joints) 0-23, breadth O'l. Length of the single joints, a 0-02, b 003, c 0-055, d 0-04, e 0-025, / 0-025, g 0-02, h 0-015. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. Genns 654. Stichocapsa} Haeckel, 1881, Prodromus, p. 439. Definition. — S t i c h o c a p s i cl a (vel Stichocyrtida eradiata clausa) without apical horn, and without basal spine. The genus Stichocapsa diflfers from the preceding Cyrtocapsa in the absence of an apical horn, and bears therefore to it the same relation as Lithocampe does to Eucyrtidium. It may be derived either from Cyrtocapsa by loss of the horn, or from Eucyrtidium by closure of the terminal mouth. 1. Stichocap>sa tetracola, n. sp. (PL 78, fig. 1). Shell smooth, spindle-shaped, half as broad as long, with three slight strictures. Length of the four joints = 3:4:4:11. The fourth jomt is the broadest, inversely conical, with acute basal pole. Pores subregTilarly square in the second and third joints, more irregular in the fourth joint. Dimensions. — Length of the shell (with four joints) 0-11. Length of the single joints, a 0-015, b 0-02, c 0-02, d 0-055 ; breadth 0-055. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 2. Stichocapsa qiiadrigata, n. sp. (PI. 78, fig. 3). Shell smooth, pear-shaped, half as broad as long, with three deep strictures. Length of the four joints = ^ : 8 : 8 : 5. The second joint is the broadest. Tlae fourth joint is scarcely larger than the hemispherical cephalis, inversely conical, with blunt basal pole. Pores subregular, square, in transverse rows, in the second and third joints of equal size, in the fourth smaller. Dimcnsiom. — Length of the shell (with four joints) 0-12. Length of the single joints, a 0-015, b 0-04, c 0-04, d 0-025; breadth 0-06. Habitat. — Central Pacific, Station 270, depth 2925 fathoms. ' S(icAocaysa = Jointed capsule ; or/xof, xav^a. 1516 THE VOYAGE OF H.M.S. CHALLENGER. 3. Stichocapsa tricincta, n. sp. (PL 78, fig. 2). Shell smooth, spindle-shaped, twice as long as broad, with three deep strictures. Length of the four joints = 2 : 5 : 5 : 10. The third joint is the broadest. Fourth joint inversely conical, with acute basal pole. Cephalis small, subconical. Pores irregular, roundish, of very different sizes. Dimensions. — Length of the shell OIL Length of the single joints, a O'Ol, h 0'025, c 0"025, d 0-05; breadth 0055. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 4. Stichocapsa suhglobosa, n. sp. Shell thorny, broad, pear-shaped, nearly spherical, almost as broad as long, with three internal septal rings. Length of the four joints = 1:2:7:2. Cephalis small, subspherical. Thorax flat, conical. Third joint very large, inflated, about twice as broad as the second and fourth joints. The latter is flat, cap-shaped, with rounded basal pole. Pores regular, circular, hexagonally framed, in the third joint twice as broad as in the second and fourth joints. Dimensions. — Length of the shell 0-24. Length of the single joints, a 0-02, h 0-04, c 014, d 0-04 ; breadth 0-2. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 5. Stichocapsa compressa, Haeckel. Lithocampe compressa, Stohr, 1880, Palaeontogr., vol. xxvi. p. 103, Taf. iv. fig. 5. Shell rough, broad, pear-shaped, almost as broad as long, with three internal septal rings. Length of the four joints =1:2:3:2. Cephalis very small, spherical. Thorax conical. The third joint is the broadest, strongly inflated. The fourth joint (in the figure of Stohr broken off) is in a well preserved specimen inversely hemispherical, with rounded basal pole. Pores very small, regular, circular. Dimensions. — Length of the shell 01. Length of the single joints, a O'OIS, h 0'027, c 0^04, d 0-022 ; breadth 0-08. Habitat. — Fossil in Tertiary rocks of Sicily ; Grotte, Caltanisetta. 6. Stichocajisa p>yriformis, n. sp. Shell rough, pear-shaped, about twice as long as broad, with three internal septal rings. Length of the four joints = 2:5:2:9. Cephalis small, spherical, hyaline. Thorax conical. Third joint very short and broad ; the fourth joint is the broadest, half as long as the shell, with an inversely hemispherical basal pole. Pores subregular, circular, small and numerous, larger in the basal third. Dimensions. — Length of the shell 018. Length of the single joints, a 0-02, h 0-05, c 0-02, d O'OO ; breadth 01. Habitat. — Fossil in Barbados. REPORT ON THE RADIOLARIA. 1517 7. Stichocapsa monstrosa, u. sp. (PI. 78, fig. 4). Shell tuberculate, twice as long as broad, irregular, horn-shaped or inversely conical, with curved axis, and with three internal septal rings. Length of the four joints = 2:7:3:4. Cephalis subspherical, with small, circular pores. The thorax is the broadest joint, half as long as the shell. The fourth joint is small, inversely conical, with a blunt, curved, basal pole. Pores irregular, roundish, partly double-contoured. Dimensions. — Length of the shell (with four joints) 016. Length of the single joints, a 0-02, h 0-07, c 0-03, d 0-04 ; breadth 0-08. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 8. Stichocapsa pentacola, n. sp. (PI. 76, fig. 1). Shell smooth, slender, pear-shaped, twice as long as broad, with four sharp strictures. Length of the five joints = 1:1:1:2:3. The three first joints are nearly equal in length, but increase in breadth. The fifth joint is the broadest, nearly spherical, with rounded basal pole. Pores irregular, roundish. Dimensions. — Length of the shell (with five joints) 0-13. Length of the single joints, a 0-017, 6 0-017, c 0-017, d 0028, e 0-05 ; breadth 007. Habitat. — Central Pacific, Station 273, depth 2350 fathoms. 9. Stichocapsa hexacola, n. sp. (PL 76, fig. 2). Shell rough, slender, pear-shaped, twice as long as broad, with five internal septal rings. The five first joints are nearly equal in length. The sixth joint is, the broadest, half as long as the shell, with a rounded, hemispherical basal pole. Pores small and numerous, subregular, circular, larger in the inflated basal third. Dimensims. — Length of the shell (with six joints) 0-2. Length of each of the first five joints 0-02, of the sixth joint 0-1 ; breadth 0-1. Habitat. — Central Pacific, Station 266, depth 2750 fathoms ; also fossil in Barbados. 10. Stichocapsa compacta, n. sp. (PI. 76, fig. 3). Shell rough very thick-walled, slender, pear-shaped, twice as long as broad, without external stricture, but with eight internal septal rmgs. The eight first joints, gradually increasing in breadth, are nearly equal in length. The eighth joint is the broadest, and one-third as long as the shell, inversely hemispherical. Pores small, circular, in the last joint larger. Dimensions. — Length of the shell (with nine joints) 0-25. Length of each of the eight first joints about 0-02, of the ninth joint 0-08 ; breadth 013. Habitat. — Central Pacific, Station 268, depth 2900 fathoms ; also fossil in Barbados. 1518 THE VOYAGE OF H.M.S. CHALLENGER. 11. Stichocapsa radicula, Haeckel. Lithocampe radicula, Ehrenberg, 1838 (partwi); Mikrogeol., 1854, Taf. xxii. fig. 23b. 1 Shell smooth, spindle-shaped, decreasing from the broader middle towards the two rounded poles, with four or five slight strictures. All five or six joints nearly equal in length, the middle (third and fourth) are the broadest. Pores subregular, circular. (To this species those forms of Lithocampe radicula, Ehrenberg, must be referred, in which the basal opening is perfectly closed by lattice-work. The other forms in which the basal mouth remains open, and which are connected with the former by transitional forms, constitute the true type of the genus Litliocampe (page 1503). Dimensions. — Length of the shell (with six joints) 012 to 0-15, breadth 0-06 to 0-07. Habitat. — Fossil in Barbados. 12. Stichocapsa suhligata, Haeckel. Lithocampe subligata, Stblir, 1880, Pateontogr., vol. xxvi. p. 102, Taf. iv. fig. 1. Shell rough, subcylindrical, irregular, with seven slight strictures. All eight joints of slightly different lengths, the third joint is the broadest ; the seventh joint is much broader than the sixth and tlie eighth joints. The latter is inversely hemispherical. CephaUs very small, spherical. Pores regular, circular, very small and numerous. Dimensions. — Length of the shell (with eight joints) 0-24 ; length of the single joints (on an average) 0-025 to 0-035, breadth 0-08. Hahitai. — Fossil in Tertiary rocks of Sicily (Grotte). 13. Stichocapsa paniscus, n. sp. (PL 76, fig. 4). Shell smooth, cyhudrical, with a blunt, conical cephalis, and a hemispherical last joint, without external strictures, but with seven or eight internal septa. Eight or nine joints nearly equal in length, the second and the last somewhat longer. Pores circular, of unequal sizes. Dimensions. — Length of the shell (with seven joints) 0-16 ; length of each joint (on an average) 0-02 to 0-03, breadth 0-07. Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 14. Stichocapsa cylindrica, n. sp. Shell rough, cylindrical, four times as long as broad, with hemispherical cephalis and last joint, without external stricture, but with ten or eleven internal septa. All eleven or twelve joints are nearly equal in length, and are three times as broad as long. Only the fiat cephalis is shorter, and the vaulted last joint longer than each of the nine or ten other joints. Pores regular, circular. Dimensions. — Length of the shell (with twelve joints) 0-24 ; length of each joint (on an average) 0-02, breadth 0-06. Habitat. — Tropical Atlantic, Station 338, depth 1990 fathoms. REPORT ON THE RADIOLARIA. 1519 Genus 655. Artocapsa} Haeckel, 1881, Prodromus, p. 438. Definition. — S tichocapsida (vel Stichocyxtida eradiata elausa) with an apical horn on the cephahs, and a basal terminal spine on the last joint. The genus Artocapsa difiers from Cyrtocapsa, its ancestral form, by the development of a vertical terminal spine, or a bunch of spines, on the base of the last joint, and bears therefore to it the same relation as Rhopalatractus does to Rhopalocanium. 1. Artocapsa fiisiformis, n. sp. (PI. 76, fig. 5). Shell spindle-shaped, rough, with five slight strictures, decreasing uniformly from tlie broader middle towards both poles, with a strong, pyramidal, terminal spine at each pole. Length of the six joints = 2:5:3:3:2:5. Cephalis hemispherical, hyaline, without pores, its horn half as large as tlie basal spine. Pores small and numerous, subregular, circular. Diincnsions. — Lengtli of the shell (with six joints) 0'2, breadtli 0'09. Length of the single joints, a 0-02, 6 0-05, c 003, d 003, c 0-02. / 0-05. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 2. Artocapsa spinosa, n. sp. (PL 76, fig. 10). Shell spindle-shaped, spiny, with five distinct strictures. Length of the six joints = 2:3:2:5:4:4. The fourth joint is the broadest, and much larger than the five other joints. The first and the last joints are similar in size and form, hemispherical, armed with some larger, irregular, conical spines. Pores irregular, roundish, of variable sizes. Dimensions. — Length of the shell (with six joints) 0'2, breadth 0'09. Length of the single joints, a 0-02, h 0-03, c 0-02, d 0-05, c 004,/ 0-04. Hahitat. — Central Pacific, Station 266, depth 2750 fathoms. 3. Artocapsa infraculeata, Haeckel. Eucyrtidium infraculeatum, Stcihr, 1880, Paleeontogr., vol. xxvi. p. 106, Taf. iv. fig. 13. Shell subcylindrical, rough, with five annular septa. Length of the six joints = 2:3:4:4:4:3. The third, fourth, and fifth joints are nearly equal in length and breadth, whilst the second and sixth are cupola-shaped. The cephalis is very small, subspherical (regarded by Stohr as a " large pore "), and bears a short conical horn. The last joint bears a buncli of basal spines. DimevMons. — Length of the shell (with six joints) 0-2, breadth 0-09. Length of the cephalis 0'02, second and sixth joints 0'03, third, fourth, and fifth joints 0-04. Habitat. — Fossil in Tertiary rocks of Sicily ; Grotte (Stohr), Caltanisetta \,Haeckel). 1 v^r(ocapsa = Bread-shaped capsiile ; ajroc, xdi^a. 1520 THE VOYAGE OF H.M.S. CHALLENGER. 4. Artocapsa quadricamera, n. sp. Shell spindle-shaped, smooth, with three sharp strictures. Length of the four joints = 2:3:4:8. The third joint is the broadest. The fourth joint is inversely conical, nearly as long as the three other joints together, and bears a strong, conical, basal spine, of half the length. The cephalis is small, subspherical, and bears a conical horn of the same length. Pores subregular, circular. Dimensions. — Length of the shell (with four joints) OlV, breadth 0-08. Length of the single joints, a 0-02, h O'OS, c 0-04. d 0-08. Hahitat. — Fossil in Barbados. 5. Artocapsa armata, n. sp. Shell slender, inversely ovate, spiny, with six deep strictures. Length of the seven joints = 2:4:6:5:4:3:2. The third joint is the broadest, inflated, and much larger than the four foUovv- iuCT, which gradually decrease in size. The small, hemispherical cejihalis bears a stout pyramidal horn of twice the length. The last hemispherical joint is armed with a bunch of stout spines, one of which is much the larger, and as long as the third joint. Pores irregular, roundish. Dimensions. — Length of the shell (with seven jomts) 0-26, breadth 0-12. Length of the single joints, a 0-02, h 0-04, c 0-06, cl 0-0.5, e 0-04,/ 0-03, g 0-02. Hahitat. — Western Tropical Pacific, Station 225, depth 4575 fathoms. 6. Artocapsa octocamera, n. sp. Shell subcylindrical, smooth, with seven internal annular septa. Five joints (the third to the seventh) are nearly equal in size, whQe the second and eighth are cupola-shaped, somewhat longer. The cephalis is smaller, with a conical horn of the same length. The last joint bears a bunch of divergent, conical spines, of different lengths. Pores small, regular, circular. Dimensions. — Length of the shell (with eight joints) 016, breadth O'OS. Length of the cephalis 0-016, second and eighth joints 0033, each of the five other joints 0-022. Eabitat. — South Pacific, Station 285, depth 2375 fathoms. 7. Artocapsa elegans, n. sp. (PI. 76, fig. 8). Shell spindle-shaped, smooth, with eight internal, broad, annular septa. The second and third jomts are the largest, the fourth and fifth of medium size, while the cephalis and the four last joints are nearly equal in length, and much shorter. The third joint is the largest. The subspherical cephalis bears a bristle-shaped horn of the same length, while the last joint is armed with a bunch of conical spines. Pores small, in the upper half of the shell regular, hexagonal, in the lower half irregular. Dimensions. — Length of the shell (with nine joints) 0-2, breadth 0-09. Length of the first and the four last joints, each 0-014 ; of the fourth and fifth, each 0-02 ; of the third 0-04, second 005. Habitat. — Central Pacific, Station 274, depth 2750 fathoms. REPORT OX THE RADIOLARIA. 1521 Legion IV. PH^EODARIA, vel Cannopylea, vel Pansolenia (Pis. 99-128). PhcBodana, Haeckel, 1879. Tripylea, Hertwig, 1879. Cannopylea, Haeckel, 1881. Pansolenia, Haeckel, 1878. Definition. — Radiolaria with a double membrane surrounding the central capsule, which bears on one pole of the main axis a peculiar astropyle, or a tubular main-opening, in the centre of a circular radiate operculum. Usually (but not constantly) a pair of small, lateral, accessory openings (or parapylse) on the opposite pole of the main axis. Extracapsulum constantly with a phteodium, or with a voluminous aggregation of peculiar dark pigment bodies (phseodeUa) covering the astropyle of the central capsule. Skeleton siliceous or silicated, always extracapsular, very rarely wanting. Fundamental form very variable, originally monaxon, often dipleuric or bilateral. The legion Ph.eodaria, or Cannopylea, in the extent here defined, was constituted liy me in 1878, in my Protistenreich (p. 102) under the name Pansolenia. This name was given on the supposition that the skeleton of these interesting Radiolaria is always composed of hoUow tubules, in contrast to that of the other Radiolaria, where it is never tubular. But I was soon convinced that this supposition was erroneous, that in a great part of the Pansolenia the skeleton is not composed of hollow tubules but of solid Ijars, and that a constant, very characteristic, and never failing mark of this group is to be found in the peculiar phseodium, a voluminous, constant, extracapsular pigment body. Therefore, in 1879, I changed the name into Ph^odakia, and having discovered in the collection of the Challenger an astonishing number of new and wonderful tyjDcs of this group, I described, in a preliminary note on it, four different orders and ten famihes with thirty-eight genera (Ueber die Phseodarien, eine neue Gruppe kieselschahger mariner Rhizopoden ; in Sitzungsberichte der Jenaischen Gesellschaft fiir Medicin and Natur- wissenschaft. Sitzung vom, 12th December 1879). In the same year (1879), Richard Hertwig, in his excellent work entitled Der Organ- ismus der Radiolarien, published the first accurate descri^^tion of the intimate structure of the soft body of the Pansolenia, and mainly of their central capsule ; and having always observed, in the few representatives examined by him, three openings in the capsule (one main-opening and two accessory openings), he called them Tripylea {Joe. cit. p. 87), being guided by the erroneous supposition that these three openings are (ZOOL. CHALL. EXP. — PART XL. — 1886.) " Rf 191 1522 THE VOYAGE OF H.M.S. CHALLENGER. constant in all members of the group. But this is by no means the case. The two accessory openings are completely absent in several families, whilst in others their number is increased. A constant and very striking character, however, of all Ph/EODAEia, is the peculiar structure of their tubular main-opening, which I call astropyle, with its radiate operculum and cannular proboscis. On account of this important and startling characteristic I proposed in 1881 to call this group Cannopylea. The two names Ph^odaria and Cannopylea both express a very striking and quite constant character of these curious Radiolaria, whilst the two names Pansolenia and Tripylea are applical^le only to a part of the whole legion. The history of our knowledge of the Ph^^iodaria is short, but very remarkable. Although hundreds of species, many of them cosmopolitan, are distributed over all oceans and all zones, although their size is in general much greater than that of the other Kadiolaria (usually 1 to 2 mm., often even 5 to 10 mm. or more), and although their form and structure are usually striking, nevertheless the Ph^odaria remained completely unknown up to the year 1859. During that year I observed the first forms living in the Gulf of Messina, and described and figured in 1862 in my Monograph five genera and seven species, viz., (l) Aulacimtha scolymantha (p. 263), (2) Tlialassoi^lancta cavispicula (p. 261, now Cannohelos cavispicula), (3) Aulosphcera trigonopa, and Aulosphcera elegantissima (p. 359), (4) Sp)ongodictyum trigonizon (p. 459, now Sagoplegma trigonizon), and (5) Coslodendrum ramosissimum, and Ccelodendrum gracillimum (p. 361). I recognised the structure of the three genera enumerated as 1, 3, and 5, as so remarkable and so different from that of the othel- Eadiolaria, that I founded three peculiar families for them, the Aulacanthida, Aulosphserida, and Ccelodendrida. The first note on the numerous remarkable Ph/EODARIA discovered by the Challenger, and mainly on the large-sized inhabitants of the deep-sea, was published in 1876 by Dr. John Murray, in his Preliminary Reports on Work done on Board the Challenger (Proc. Roy. Soc, vol. xxiv., read March 16, 1876). He pointed out {loc. cit., p. 535), that the tow-nets, sent down to a great depth (according to a new plan, adopted in April 1875) l3rought up on every occasion a great many new and peculiar Rhizopods, which had never been observed in the nets used near the surface. " The shells of all have an exceedingly beautiful tracery, a fenestrated appearance often, which a closer examination shows to be caused by pit-like dejDressions. Some have only one, others have several openings, through which the sarcode flows. The sarcode of all these deep-sea Rhizopods has many large black -brown pigment-cells. At times they come up with a good deal of the sarcode outside of the shell ; and two specimens have been seen to throw out elongated pseudopodia" (loc. cit, p. 536). Dr. John Murray distinguished at that time not less than fifty species of these interesting deep-sea Rhizopods and called them provisionally Challengerida ; a term which we retain here for the largest and most characteristic family. He gave at the same time, in an accompanying plate (xxiv.), six REPORT ON THE RADIOLARIA. 1523 figures of new Ph.eodaria, the uames of which (as found l)y mc in 1879 in the corres- ponding preparations) are the following; (l) Challengeria naresii, (2) Chcdlengeria aldrichii, (3) Bivaha comj^ressa [no-^ = Conchopsis compressa), (4) Tuscarora helknapii, (5) Cliallengeria circopora (now= Circoporus sexfurcus), and (6) Haeckeliana porcellana. A great number of these Challengerida (twenty species) were afterwards figured by Dr. John Mm-ray in the Narrative of the Cruise of H.M.S. Challenger, 1885, vol. i. part 1, p. 226, PI. A; viz., fourteen species of Challengeria and six species of Tuscarora. The most important advance in the knowledge which we had of the peculiar organisation of the Ph^odakia, was made by the accurate description which Richard Hertwdg published, in 1879, of the intimate structure of their central capsule, and mainly of its peculiar openings. He examined living at Messina the following three forms, described in my Monograph; (l) Aulacantha scohjmantha, (2) AidosphcBva elegantis- sima, and (3) Cailodendrum ramosissimum. Besides, he described an interesting new genus, Coelacantha anchorata; and another new form, which he placed in the Aulosph?erida, as Aidosphcera gracilis, Ijut which really was a new genus of Sagos- phserida, here described as Sagoscena gracilis. Finally, Hertwig first discovered that the peculiar bodies, described by Ehrenberg as Dictyocha and placed by him in the Diatomea [Polygastrica), were the isolated pieces of the skeleton of a true Phceodanum, and that they were scattered loosely in great numbers over the surface of the jelly-sphere, just as are the hollow spicula of T7ialassop>lancta or Cannohelos. The six species mentioned, of which Hertwig gave a very accurate description and very instructive figures, belong to six different genera, and these represent six difi'erent families of Ph^^odaria, viz. ; Aulacanthida, Aulosphserida, Coelodendrida, Cannospbaerida, Sagosphserida and Cannorrhaphida. He found that all these six forms, in spite of great differences in the form and structure of their skeleton, were identical in the structure of the central capsule ; and since he observed constantly three openings in its double wall (a large main-opening on the oral pole, and a pair of lateral accessory openings on the aboral pole of its main axis) he called them Tripylea {loc. cit., p. 87, 94). But he also pointed out the remarkable shape of their voluminous extracapsular body, and especially the characteristic position, size, colour and composition of the large pigment body, which I had called the phseodium. The accurate description of the gigantic and elegant skeleton of a new" Phceodarium, surpassing all other known Radiolaria in its extraordinary size (15 mm.), was published in 1882 by 0. Biitschli (in Zeitschr. f. wiss. ZooL, vol. xxxvi. p. 486, Taf. xxxi.). He called it Coelothamnus davidoffii, in honour of its discoverer, who had found it floating on the surface of the Gulf of Villafranca, near Nice. He placed it among the Coelodendrida, ; it belongs, however, to that part of this group which possesses a nasal tube, and which I afterwards separated under the name Coelographida. 1524 THE VOYAGE OF H.M.S. CHALLENGER. The total number of Ph^odaeia, hitherto described and illustrated by figures, amounts therefore to seventeen species, viz., the seven species first described by myself (in 1862) ; the six new species figured by Dr. John Murray (in 1876) ; the three new species discovered by Hertwig (in 1879) and the single species last-mentioned described by Butschli (in 1882). The rich collection of the Challenger has added to this small number such an astonishing wealth of new and remarkable forms, that I can describe in the following system of Ph.^odaeia not less than eighty-four genera and four hundred and sixty-five species. These belong to fifteen different families and four different orders. But this great number is probably only a small part of the numerous interesting Ph^odaria, which are abundantly distributed overall the oceans; those (e.g.) of the Indian and of the Arctic Oceans are almost unknown. The great majority of these wonderful Ph^odaria are inhabitants of the deep-sea, mainly of the southern hemisphere, and are so common in many stations explored by the Challenger, that its collection contains many thousands (or rather hundreds of thousands) of well-preserved sjiecimens. A smaller part of the legion is found on the surface, widely distributed over all oceans; some of these are very common (as, e.g., Aulacantlia, AidosjihcBra, Sago-iphmxt, Calodendruni, CastaneUa, &c.) and it is difficult to explain how they could entirely escape the eyes of all former observers. The three general characters whicli distinguish the Ph.eodaria easily and constantly from all the other Radiolaria are the following: — (l) the double membrane, a thick outer and a thin inner envelope, of the big central capsule ; (2) its typical main- opening or astropyle, placed on the oral pole of the main axis, and distinguished by a peculiar radiate operculum, with tubular proboscis ; (3) the phseodium, or the peculiar voluminous pigment-body, which constantly lies in the oral half of the calymma, surrounds the oral part of the central capsule, and is composed of numerous phajodella, or singular pigment-granules of green, olive, brown or black colour. Besides these three general and never failing marks of the Ph^odaria, the majority of this legion (but by no means all) possess the three following peculiarities ; ( 1 ) two parapylse or accessory openings of the central capsule, placed laterally (at the right and left) on the aboral pole of the main axis (wanting in the Challengerida, Medusettida, Castanellida, and perhaps in some other families) ; (2) a characteristic skeleton which is always extracapsular, wanting only in the Phseodinida, incomplete in the Cannorrhaphida and Aulacanthida, but perfectly developed and of very various shapes in the twelve other families ; usually this silicated skeleton is composed of hollow tubules, which are filled up ^-•y jsUy (Pansolenia) ; but in some families it is composed of ordinary solid network, not different from that of the other Radiolaria, eg., especially in the Castanellida and Sagosphajrida ; (3) an extraordinary size of the body, as well of the central capsule and its nucleus, as of the extracapsular skeleton ; the majority of Ph^odaria have a diameter of 1 to 2 mm., and arc therefore from ten to twenty times as large as the REPORT ON THE RADIOLARIA. 1525 majorit)' of the other Radiolaria ; in some gigantic forms tlic (liameter of tlie unicellular body reaches 20 or even 30 mm. The Central Capsule of the Ph.eodaria is the most important part of their body and preserves in all families of this legion the same essential structure, and nearly the same form, in striking contrast to the extraordinary variety and complication of the skeleton. As alread)^ mentioned, it differs from the central capsule of all the other Radiolaria in two most important peculiarities ; firstly, the double membrane of the spheroidal capsule, and secondly, the singular structure of its constant main-opening, the astropyle. A third constant character is the considerable size of the enclosed nucleus, the diameter of which usually equals about half of that of the capsule itself. The diameter of the capsule is, in the majority of Ph^odakia, O'l to 0"2 mm., often also 0"3 to 0'4, rarely more than 0'5, or less than 0"05 mm. The position of the central capsule is somewhat different in the four orders into which we have divided the Ph.eodaria. It lies in the centre of the spherical, concentric calymma in all the P h se o c y s t i n a, or in those Ph^odaria which possess no complete lattice-shell — Phasodinida, Cannorrhaphida, and Aulacanthida (Pis. 101-105). The P h £6 0 s p h a3 r i a (comprising the Orosphserida, Sagosphaerida, Aulosphaerida, and Cannosphserida, Pis. 106-112) all possess a very big, usually spherical lattice-shell, and here the central capsule is much smaller than the latter and lies in its centre. Another position is constantly occupied by the central capsule in all P h se o g r o m i a (Pis. 99, 100, 113-120; the families Challengerida, Medusettida, Castanellida, Circoporida, Tuscarorida), which have a peculiar mouth on the lattice-shell, placed on the oral pole of its main axis ; the central capsule lies in the opposite aboral half of the shell cavity. The Phajoconchia finally (Pis. 121-128, the families Concharida, Coelodendrida, and Ccelographida) all possess a bivalved shell, and the capsule is here enclosed between the two valves of the shell. The form of the central capsule is constantly spheroidal, slightly depressed in the direction of the main axis, and therefore comparable to the spheroidal form of our globe. The depression is generally very slight, so that the proportion of the minor vertical main axis to the major horizontal or equatorial axis is about 4:5 or 5 : G, often even 8 : 9 or less ; but sometimes the proportion becomes 3 : 4, or even 2 : 3, so that the capsule becomes nearly lenticular ; very rarely its form becomes almost perfectly spherical (PL 101, fig. 1). The main axis stands always vertically, and is distinctly marked by the peculiar shape of the astropyle, placed on its oral pole. Usually this pole, in the living and freely floating Ph-^eodaria seems to be the lower pole, directed downwards (as also in the Nassellaria) ; but in some families it seems to be inversely directed upwards, as in the Challengerida and Tuscarorida (Pis. 99, 100). The two membranes of the central capsule possess in all PH^i:oDARiA a very different shape, and were in all preparations which I could accurately examine (some hundreds 1526 THE VOYAGE OF H.M.S. CHALLENGER. l^elonging to all families) separated by a clear, rather wide interval, filled up either by a colourless fluid or by a structureless jelly (PI. 103, fig. 1 ; PL 123, figs. 8, 9,&c.). They are in direct connection only at the openings. In the living Ph.^odaria, however, their distance is very small, or they are in immediate contact without any interval (PL 101, fie. 10 ; PL 102, fio". 1). According to the observations of Hertwig, the two membranes are always in close contact, and without interspace, in the living Ph.eodaria ; and the space between them is an artificial product due to the influence of the preserving fluid or of certain chemical agents. In every case it is very easy to separate both membranes completely, except at the openings, where they are in direct connection. "We distinguish both membranes shortly as ectocapsa and endocapsa. The ectocapsa, or the outer memlDraue of the central capsule, is rather firm and durable, double-contoured, elastic and difiicult to destroy. Its physical and chemical qualities seem to approach those of chitin. It becomes, however, stained red by carmine, and yellow by nitric acid. Usually it appears structureless and refracts the light strongly. In a few cases, however, it exhibits, when examined by strong lenses, a fine puncta- tion ; and in some Aulacanthida (especially in some big forms of Aulogrcqyhis and AulosiKithis) the entire ectocaj^sa was densely covered with peculiar curved, or S-shaped dark corpuscles (PL 114, fig. 13). They were all of the same length, about O'Ol, and seemed to lie on its inner face. The endocapsa, or the inner membrane of the central capsule, is much thinner than the outer, with which it is in immediate connection only at the openings. It encloses the entire contents of the capsule, and becomes very distinct, as soon as the latter are dissolved by chemical agents, or stained by carmine. In the majority of well- preserved preparations it is irregularly plicated, and resembles a thin, but firm, crumpled paper. Isolated pieces of the endocapsa are completely structureless, but exhibit also a considerable resistance, in spite of their minute thickness. The openings of the central capsule exhibit in the Ph.eodaria a greater variety than their discoverer, R. Hertwig, supposed. The majority of the legion, certainly, possess the three openings described by him, and are therefore true Tripylea. Some families, however, have only one opening, the astropyle, which is generally present (Challengerida, Medusettida, Castanellida, and Phaiocolla among the Phseodiuida, PL 101, fig. 1). In some other families there is a variable number of accessory openings or parapylse, one, three, or more, e.g., especially in the Circoporida and Tuscarprida. The former may be caUed Astropylea, the latter Sporopylea. Thus only a single opening to the central capsule is constant in aU Ph.eodaria without exception, and that is the astropyle, or the large main-opening with its peculiar structure. The astropyle, or the single constant main-opening of the central capsule, is distinguished by a very remarkable structure, and is sufficient of itself to separate the REPORT ON THE RADIOLARIA. 1527 Ph.^odaria from all the other Kadiolaria, and from the other Rhizopoda in general. It is always placed on the oral pole of the main axis, forming here a peculiar cap- shaped or flatl)^ conical elevation, the centre of which is prolonged into a short, cylindrical tulude ; we call the latter shortly a proboscis, and the former an operculum. To understand better the different forms which these important parts assume in the difierent families, compare PI. 101, figs. 1-6 ; PL 102, fig. 1 ; PL 103, fig. 1 ; PL 104, figs. 1-3; PL 111, fig. 2; PL 123, figs. 1-9; PL 127, figs. 4-6; PL 128, fig. 2, &e. Compare also the first very accurate figures which R. Hertwig has given in 1879 (loc. cit.) in his Taf. x. The operculum of the astropyle, the most important part of this main opening (" der Oefluungshof der Hauptofl:nung," in the description of Hertwig), is a circular convex plate, always more strongly vaulted than the surrounding part of the capsule membrane, and is sharply separated from it by a circular, often thickened and double- contoured margin. The operculum covers the main-opening like the lid of a tea- kettle, and the proboscis arising from its centre is comparable to the handle of that lid. The diameter of the circular operculum is usually about half as long (rarely as long) as the radius of the central capsule, therefore in the majority of Ph.eodaria 0"03 to 0*06, sometimes 0"1 and more. Its form is sometimes more conical, sometimes more like a mamma. Its height is usually about equal to half its diameter. It always exhibits a very distinct radial striation, produced by numerous prominent radial ribs, which arise in the centre and end at the circular sharply truncated margin. The usual number of these radial ribs may be, in the operculum of smaller capsules, from thirty to fifty, in those of medium size from sixty to ninety, and in the largest two hundred to three hundred or more. Usually the ribs are simple (PL 101, figs. 1, 2, 6, 10 ; PL 127, figs. 4—6 ; also in all figures given by Hertwig) ; but sometimes, mainly in the biggest Aulaeanthida, they are distinctly branched in a centrifugal direction (PL 114, fig. 13 ; PL 115, fig. 3). Hertwig is of the opinion that the radial ribs are thickened ridges of the endocapsa ("leistenartige Verdickungen der inneren Membran"), and that the ectocapsa covering it is structureless (compare his figs. 1 and la, in Taf. X.). But I am convinced now, by numerous experiments and observations, that the radiate operculum is a part of the outer, not of the inner membrane. That part of the latter which lies immediately beyond the former, and which may be called the " inner operculum," also exhibits usually a fine radial striation ; but this is probably only the cast of the stronger and much more prominent radial ribbing of the " outer operculum " belongmg to the ectocapsa. The latter exhibits a large circular opening with thickened margin, when the radiate operculum is taken from it. The operculum becomes stained intensely red by carmine, yellow by nitric acid, corresponding to the ectocapsa, the main-opening of which is closed by it. Tlie proboscis, or the cylindrical tubule, which arises in the centre of the 1528 THE VOYAGE OF H.M.S. CHALLENGER. operculum, is often rather short, and bears the same relation to it as the nipple does to the human breast (PI. 104, fig. 2). But usually it is more or less prolonged and often about as long as the radius of the capsule, rarely nearly as long as its diameter (PI. 101, fig. 1). Its form is usually a slender cylinder, sometimes somewhat conical and tapering towards the distal end. It is more or less curved or S-shaped in the majority of preparations (PL 115, fig. 3; PI. 127, fig. 6, &c.). Its thin wall is a dii'ect prolongation of the outer membrane of the capsule, therefore it appears as a direct apophysis of the operculum, when this is detached from the latter. The opening at the distal end of the proboscis, through which the endosarc is thrown out, is circular. The parapylse, or the accessory openings of the central capsule, exhibit in all Ph.eodaria the same form and structure, but vary in number and disposition. They are recognised with difticulty in the smaller species, since they are always of small size, and may be easily overlooked. They seem to be completely wanting in the following families :— Challengerida (PI. 99), Medusettida (Pis. 118-120), Castanellida (PI. 1 13), and in single genera of other families, as in Phceocolla (PI. 101, fig. 1). The majority of Ph^odaeia seem to possess the two lateral parajjylae, first described liy Hertwig, placed at a variable distance on each side of the aboral pole, to the right and left (PL 101, figs. 2, 6, 10; PL 103, fig. la; PL 104, figs. 1, 2« ; PL 123, figs. 1, 8«, &c.). The horizontal axis, in which the two parapylse lie, is the frontal or lateral axis ; and the plane, which passes through the three openings of these " Tripylea," is the frontal or lateral plane. The number of the parapylse seems to be variable in the two families, Circoporida and Tuscarorida, which also difi"er from the other Ph^odaria in the peculiar (porcellanous) structure of their shell-wall. The number seems to vary even in the single species of one genus ; and the following cases may be found: (A) a single parapyle, placed on the aboral pole of the main axis and directly opposed to the astropyle (on the oral pole), as in Tuscaridium (PL 100, fig. 8); (B) three equidistant parapylse, one of which is placed in the sagittal plane, and the two others one on each side of it, to the right and left, as in Tuscarora (PL 100, figs. 1—6) ; the three parapylse seem to correspond here to the three long feet, or the tubular aboral apophj^ses of the shell, which are arranged in a similar manner to the three cortinar feet of the Nassellaria ; (C) four equidistant parapyla3, placed in pairs on the poles of the diagonal axes of a horizontal plane, as in Tuscarusa (PL 100, fig. 7); they seem here to correspond to the four crossed aboral feet; (D) six to eight or more jDarapylse, probably in the different genera of Circoporida (Pis. 114^117); perhaps each radial tube, which is surrounded on its base by a circle of pores, here corresponds to a separate parapyle. The number of well-preserved central capsules belonging to the two latter families, however, which I could examine was relatively small, and their examination very diflicult ; therefore these numbers are not stated with satisfactory certainty and require a further more accurate examination. REPORT ON THE RADIOLARIA. 1529 The minute structure of the parapyliB (or " Neben-OefFnungen") has been described already very accurately by Hertwig (loc. cit., p. 95, Taf. x. figs. 1-T1&). The two membranes of the capsule are in direct and immediate connection on each parapyle. The strong outer membrane arises in the form of a ring or of a short cylindrical tubule (coUare paraboscidis or " Oeffnungshals "), is then reflected . inwards, and connected at the bottom of the cjdindi'ical cavity with the delicate inner membrane. From this connective ring arises a short conical or cylindrical tubule, which we call shortly the "paraboscis." According to Hertwig (who calls it " Oefi'nungskegel") the paraboscis is a direct prolongation of the inner membrane only. My own observations have led me to the opinion, that the paraboscis of each j^arapyle is a direct prolongation of the outer membrane (similarly to the larger proboscis of the astropyle), and that the basal connective ring is, therefore, the inner opening of the paraboscis, through which the entosarc enters, being protruded through its outer circular opening. Usually the paraboscis of each parapyle is only a short cylinder, arising by a conical base ; but sometimes, especially in some Aulosphserida and Sagosph^erida, it is prolonged into a slender tubule, nearly as long as the radius of the central capsule. It has been already figured by Hertwig (loc. cit., Taf. x. figs. 6—8). It seems, therefore, that the paraboscis of the accessory openings is developed in a way similar to the proboscis of the main-opening, and that the chief difference between the two is indicated by the large radiate operculum of the latter. The cavity of the endocapsa, or the spheroidal space enclosed by the inner membrane of the central capsule, is filled up in its central part by the big nucleus, in its peripheral part by the endoplasm, or by the internal protoplasm, which is in com- munication with the outer or extracapsular protoplasm by the openings of that capsule. The endoplasm, or the intracapsular sarcode, is rather opaque, finely granulated, and usually filled up by numerous small clear spherules of equal size, which are more or less regularly arranged and equidistant. These spherules have usually a diameter of O'Ol to 0"015, rarely more than 0'02 or less than 0"005 mm. ; their size is generally equal in each capsule. They have been abeady described and figured in my Monograph, as " wasserhelle kugelige Bliischen," and are probabl)^ vacuoles or small vesicles filled up by jelly or by a clear fluid. Usually each vesicle contains a small dark granule of fat, or a group of such granules connected together ; and in these Hertwig observed a vibrating molecular motion. The central capsule of many PniEODARiA contains, besides the vacuoles, often granules of pigment (usually red or yellow) and sometimes numerous groups of small crystals, placed mainly beyond the operculum of the astropyle (PL 127, figs. 4—7). The outer layer of the endoplasm, placed immediately beyond the endocapsa, often exhibits a fine striation, as if composed of delicate fibrillse. This fibrillar striation is usually most distinct on the base of the openings, where also the endoplasm becomes stained very iutensely by carmine. The astropyle as well as (ZOOL. CHALL. EXP. — PART XI-. — 1886.) Kr 192 1530 THE VOYAGE OF H.M.S. CHALLENGER. the paraj^ylse often exhibit here, when observed from the face, a distinct radial striatiou (compare Hertwig, loo. cit., p. 98, Ta£ x. figs. 6—14). Perhaps the radiate shape of the operculum is only produced by radial folds of the endocapsa placed beyond it, and these folds may be in turn the product of the radial fibrillse, which are prominent beyond the astropyle. On the other hand, these fibrillae may be compared to the muscular fibrillse or " myophane filaments " in the ectosarc of the Infusoria, and may perhaps effect by their contraction a dilatation of the openings of the capsule. The nucleus of the PHiEODAHiA is always very large, usually about half or two-thirds as broad as the central capsule, and placed either in its centre, or sometimes nearer to one pole of the main axis, which is common to the capsule and its nucleus. Therefore the diameter of the latter is usually half or even two-thirds of that of the capsule, and may be in the majority 0"05 to 0'15, often 0'2 to 0'3, rarely more than 0'4 or less than O'Ol mm. The form of the nucleus is rarely spherical, usually sjiheroidal, and it is more depressed in the direction of the main axis than the capsule itself. In my Monograph, where I gave the first description of it, I called it " Binnenblaschen." The membrane of the vesicular nucleus is thin but rather firm, and contains a rather clear, finely granulated substance, in which numerous nucleoli are usually scattered. (Compare PL 101, figs. 1-10; PI. 102-104; PI. 123; PL 127, &c. ; the nucleus is marked by n, the nucleoli by /.) The nucleoli are very different in respect to their form, size, number and arrange- ment. Since these differences are very great even in different specimens of a single species (as, e.g., in the common cosmopolitan Aulacantha scolymantha, Aulosphcera trigonopa, Ccelodendrum ramosissimuin, &c.), it is probable that they represent different stages of development and multiplication, and that the smallest fragments of the nucleoli, or the final results of their repeated division, become the nuclei of the flagellate spores, which are developed in the Ph^odaria just as in the other Radiolaria. In the majority of nuclei examined, the number of the enclosed nucleoli proved to be very great, fifty to eighty or more, often some hundreds, the greater their number the smaller their size. Their form is usually irregular, roundish, or even amoeboid — probably the result of amoebiform motions (PL 101, fig. 1). Sometimes the nucleoli were regularly spherical, equidistant, and connected apparently by a delicate network (PL 101, fig. 2). (Compare PL 102-104, 111, 123, and also Taf. x. of Hertwig, loc. clt.). The calymma, or the extracapsular jelly-veil, is in the PniEODARiA always well developed and usually much larger than the enclosed central capsule. The entire volume of the calymma may be three to six times as great as that of the capsule in the majority of this legion ; but in the large Aulacanthida, Aulosphserida, Coelo- dendiida, Ccelographida, &c., the volume of the former is twenty to fifty times as great as that of the latter, or even more. The jelly substance is rather firm and consistent, clear, structureless, and becomes more or less intensely stained by carmine. In the RErORT ON THE RADIOLARIA. 1531 larger forms it is often filled by numerous large alveoles, which are usually absent in the smaller forms. These extracapsular alveoles are most strongly developed in the caljTuma of the Phseoey stina, or the Ph.eodaria with incomplete skeleton, embracing the three families Phseodinida, Cannorrhaphida and Aulacanthida (Pis. 101- 104). Usually the calymma is here very voluminous and entirely filled up by large alveoles, which are either spherical, ii'regularly roundish, or polyhecbal by mutual compression. These alveoles or vacuoles have no peculiar wall, but are only cavities in the homogeneous substance of the jelly, and are filled by a clear aqueous fluid. Between these the network of the anastomosing pseudopodia is expanded. They exhibit, therefore, the same shape, as was first observed in Thalassicolla and in the P o 1 y- e y 1 1 a r i a (Collozoida, Sphserozoida and CoUosphserida). The relation of the calymma to the skeleton is in the Ph^odaria of the same importance as in the other Radiolaria, and we may also here distinguish a primary and a secondary calymma. The primarj' calymma is that on the surface of which at a certain period of life (in the " shell-building period ") the fenestrated shell is secreted in the majority of Ph.eodaeia. The secondary calymma, however, is formed after this period, and envelops the shell itself as well as its apophyses externally. Usually the entire skeleton seems to be enveloped by the secondary calymma. The parts of the extracapsular body, w^hich are enclosed in the gelatinous calymma, possess a peculiar importance in the Ph^eodaria ; these are firstly the sarcomatrix and the pseudopodia arising from it, and secondly the phaeodium. The sarcomatrix, or the layer of extracapsular sarcode (ectoplasm), which immediately surrounds the central capsule, is very thick and more strongly developed in all Ph,^odaria than in all other Eadiolaria. Its extraordinary size has been already mentioned by Hertwig (1879, loc. cit., p. 99). It is in dii'ect connection with the intracapsular sarcode (or the endoplasm) only by the openings of the central capsule, and mainly by the astropyle. Very numerous radial pseudopodia arise every^vhere from the sarcomatrix and run to the surface of the calymma, usually forming a rich network in it by means of numerous branches and anastomoses (compare PL 101-104). On the surface of the calymma the meshes of this network are very numerous, and there arise from its nodal points the terminal pseudopodia, which float freely in the surrounding water. The metamor- phoses of this network of sarcode, the perpetual changes in the number and size of its meshes, and the movements of the sarcode streams as well as of the small granules running in it, are alwaj^s very manifest in the Ph^odaria and in the big forms of this legion (mainly in the Aulacanthida) they are better observed than in the majority of other Radiolaria. In many Ph^eodaria (and perhaps in all) a part of the pseudo- podia seems to have undergone a local difi"erentiation, for special physiological pur- poses ; and Hertwig has described a peculiar conical contractile body, which arises in Ccelodendrum between the two parapylse (loc. cit., p. 100, fig. 3). Further examination 1532 THE VOYAGE OF H.M.S. CHALLENGER. of these interesting organs in living Ph^odaria is required. Usually the sarcode, issuing from the openings of the capsule, forms a stronger cylinder, with peculiar movements. The phaeodium, or the peculiar dark extracapsular pigment-body of the PHiEODARiA, is one of the most important and most characteristic parts of their organisation, and has induced me to derive their name fi-om it ; it is not less typical for the whole legion, than the astropyle with its radiate operculum and the proboscis ; and both these important parts are always in direct topographical and physiological connection. Whilst I have missed the phseodium in no Phseodarium in which the soft body was well preserved, I have not found it. in any other Radiolaria ; for the similar extra- capsular pigment bodies, which are found in some species of Tlialassicolla and some other S ji h a3 r e 1 1 a r i a, have a composition and signification diflerent from that of the phajodium — an exclusive peculiarity of the Ph.eodaria. The typical importance of the phseodium for aU members of this legion is proved by the following five facts : — (l) its constant presence in all Ph^obaeia ; (2) its constant excentric position in the oral half of the calymma ; (3) its constant relation to the astropyle, the operculum and the proboscis of which is always surrounded by it ; (4) its constant considerable size, its volume being usually greater than that of the central capsule, the aboral half of which is covered by it ; (5) its constant colour and morphological as well as chemical composition. These five facts together demonstrate by their absolute constancy the high morphological and physiological importance of the phseodium for this peculiar subclass of Radiolaria, although its true nature is difiicult to make out, and its main function is not yet sufliciently known. The first remarks that have been made on the pha^odium were published in 1862 in my Monograph, where I noticed the peculiar dark brown extracapsular pigment body and its excentric position covering only one-half of the central capsule, in Aula- cantha (p. 263, Taf. ii. figs. 1, 2), in Thalassoplancta (p. 262, Taf. iii. fig. 10), and in Ccelodendrum (p. 361, Taf xxxii. fig. 1). Its general presence and peculiar composition were first recognised by Dr. John Murray, who had, during the Challenger Expedition, the first opportunity of examining many big living Ph^odaria brought up from great depths. He gives in his first Pieport (1876, loc. cit., p. 536), the following important notice : — " The sarcode of all these deep-sea Rhizopods has many large black-brown pigment-cells. Small bioplasts are scattered through the sarcode. These collect into capsular -like clumps when the animal is at rest, and are quickly coloured by carmine." In 1877 Dr. John Murray sent me the wonderful collection of Ph^^iodaria brought home by the Challenger, and I had now the best opportunity for examining the pha3odium in hundreds of well-preserved specimens. Supported by these extensive observations, I gave, in 1879, in a preliminary paper,^ a fuller description of the 1 Ueber die Phoeodarien, eine neue Gruppe kieselschaliger mariner Rhizopoden, Sitzungsh. med.-nat. Gesellsch. Jena, December 12, 1879, pp. 3, 4. REPORT ON THE RADIOLARIA. 1533 phaeodium, and of the plifeodella (or the peculiar dark pigment-granules composing it). At the same time R. Hertwig published his olbservations on the big living Tripylea examined by him at Messina, and pointed out particularly that the constant presence, comjiosition, and ari'angement of this excentric extracapsular pigment-body was most characteristic, and sufficient in itself to distinguish this group from all the other Radio- laria (1879, he. cit., p. 99). The most stiikiug peculiarity of the phaeodium, and the most important on account of its absolute constancy, is its excentric position, covering only the oral hemi- sphere of the central capsule, and wholly or partly wanting on the aboral hemisphere. This constant topographical relation to the capsule never fails, and may be always observed at the first glance, when the body is seen from the side (the main axis of the capsule being perpendicular to the axis of the eye of the observer), (compare PI. 101, figs. 6, 10; PL 102, fig. 1 ; PL 103, fig. 1, &c.). The phaeodium envelops, therefore, the oral half of the capsule completely, and especially the astropyle in its centre ; hence, the radiate operculum and the proboscis arising from the latter cannot be seen usually before the former is removed. The general form of the entire ph^odium, in consequence of this excentric j^osition, is concavo-convex (or crescentic in longitudinal section), its concave face embracing the oral or anterior face of the capsule, and its convex face being turned to the surface of the cal}Tnma. The topographical relation of the phaeodium to the surrounding shell is also very characteristic in the suborder P h ge o g r o m i a, or in those PH^aEODARiA which possess a peculiar shell-mouth placed on the oral pole of its main axis. Here the capsule is always placed in the aboral half of the shell- cavity, the phaeodium in its oral half, separating the astropyle from the mouth of the sheU, both of which lie in the main axis ; as in the Challengerida (PL 99), Tuscarorida (PL lOO), Castanellida (PL 113), Circoporida (PL 115), and Medusettida (PL 118-120). In this suborder (the Phaeogromia), the volume of the phaeodium may be, on an average, about as great as that of the central capsule, whilst in the majority of other Ph^odaria it is much greater than the latter. A similar topographical relation between the phaeodium and the enclosing shell, as in the P h ae o g r o m i a, also exists in the suborder P h se o c o n c h i a, or in those Ph.eodaria, which are distinguished from all the others by the possession of a bivalved shell (PL 121-128). The two valves of this curious shell, which resembles that of the Brachiopoda, are dorsal and ventral, and the tripylean central capsule is always so placed between them that its two lateral parapylae (right and left) lie in the frontal plane of the shell, where a large frontal fissure opens between the opposed margins of the two hemispherical or cap-shaped valves. The phaeodium is also placed here on the oral half of the capsule and surrounds its astropyle ; but it exhibits some differences in the three families ofPhaeoconchia. 1534 THE VOYAGE OF H.M.S. CHALLENGER. The Concharida, the bivalved shell of which is simple, and without tubular apophyses (PI. 123-125), possess a relatively small central capsule, which usually fills wp only the third or fourth part of the shell-caAdty. This is the aboral or posterior part, on the apex of which both valves are united by a ligament in some Concharida (PL 123, figs. 8, 9). The oral or anterior part of the shell-cavity (usually two-thirds or more) is filled up by the phseodium, and this is usually bifid, being divided by a frontal constriction into two wings or lobes ; the dorsal wing is hidden in the upper valve of the shell, the ventral wing in the lower valve ; both wings are usually united only by a small central bridge, and this bridge of the phreodium is pierced in its centre by the proboscis of the astropyle (PI. 124, figs. 6, 10; PI. 123, figs. 8, 9). The Coelodendrida have a different shape (PI. 121). Their bivalved shell is rela- tively small and tiny, and bears on the two poles of the sagittal axis two conical apophyses or gale«, from each of which three or four very large, dichotomously branched tubes arise. The central capsule fills up the cavity of the bivalved shell almost entirely, and the voluminous dark phseodium envelops both to such an extent that the shell and the enclosed capsule are often hidden in it completely. Therefore I arrived in my first description of Ccelodendmm (1862, loc. cit.) at the erroneous conclusion that the capsule lies outside, not inside the shell. The first accurate figure and description of its structure was given in 1879, by Hertwig {loc. cit., p. 99, Taf X. fig. 3). The central capsule {v) is here separated from the bivalved shell (m) only by a very small distance, and the oral part of both is hidden in the phseodium. I find, however, in the majority of the numerous preparations of the Challenger collection, the volume of the phseodium much greater, and it often envelops the entire shell. The Ccelographida, finally, have a phseodium of the most remarkable shape, since in their bivalved shell a peculiar reserve store or magazine of phseodella, which we call the "phseocapsa" is developed for it (PL 126-128, g.t.m.). The bivalved shell has in these most perfect PhyEODARIA a structure similar to that in the Coelodendrida ; but they differ from the latter in the stronger development, and greater differentiation of the two apical galeae, and the large hollow tubes arising from them. These two helmet-shaped cupolse, the galese {g), which arise from the two valves on the poles of the sagittal axis, are in the Ccelographida usually larger than the valves themselves, and are not closed, as in the Coelodendrida, but open by a tubular apophysis at their base, the nasal tube or rhinocanna (t). The apex of the galea is connected with the open mouth of the rhinocanna by a single or double frenulum (6). The two nasal tubes or rhinocannse (a dorsal and a ventral) lie in the sagittal plane of the body (and run from the base of each galea along the anterior convexity of the valve to its oral margin. Here is placed the proboscis of the astropyle, between the two opposed mouths of the rhinocannse (PL 128, fig. 2). The phseodium is usually hidden entirely heport on the radiolaria. 1535 ill the two plia30capsa3, which are composed of the two galeae (g), and the two rhinocauna3 arisiug from them (PL 127, figs. 4—9). A part of the phaeodella is usually thrown out by the mouth of the latter (?»-). The characteristic colour of the phseodium exhibits numerous different tints between green, brown, and black. It seems to be in the majority blackish-brown or greenish- brown, very often olive, more rarely almost quite green or red-browTi. Usually the colour is so dark, intense and opaque, that the parts enclosed by the pha^odium, mainly the oral hemisphere of the central capsule and the astropyle, are completely hidden in it. The chemical composition of the phajodium demands further accurate researches ; unfortunately I have not been able to make out its true nature, since numerous different experiments furnished no certain general results. The pha3odella, or the pigment-corpuscles, which compose the phseodium, aggre- gated in huudi'eds, and in the bigger species in thousands, are usually spherical, some- times somewhat ellipsoidal, at other times spheroidal or lenticular ; but usually numerous smaller, ii-regular, roundish particles are intermingled between the larger and more regular corpuscles, and often the main mass forms a very fine black powder. The size of the phaeodella is very variable, not only in the different species, but also in one and the same individual. The larger phseodella have a diameter of O'Ol to 0'02, the smaller of 0'004 to 0"008 mm. ; but there also occur very big forms of 0'04 to 0"05 mm., or even more, and very small ones of O'OOl mm. or less. Usually the phseodium appears as an aggregate of numerous larger and smaller phseodella, which are very different in size as well as in the intensity and tint of their colour, and are irregularly crowded in a black, powder-like substance. The morphological nature of the phaeodella is also difficult to make out. I have already pointed out in my first description of Aulacantha, Tlialassoj^lancta and Coelodendrum (1862, loc. cit.), that a great part of these pigment-corpuscles are true cells, composed of a nucleus and protoplasm, which contains granules of pigment, and is enveloped by a membrane. Dr. John Murray, who had during the Challenger voyage the opportunity of examining numerous different living Ph^odaria, and staining them by carmine, also asserts that a great part of those dark corpuscles are " large black -brown pigment-cells" (1876, loc. cit., p. 536). Numerous preparations of the Challenger collection, well preserved in glycerine, and stained by carmine, contain Ph^odakia belonging to different families, the phasodium of which contains numerous such " pigment-cells," with a dark red nucleus, and so similar are these cells, that every histologist should recognise them. But in strange contrast to this is the fact, that in numerous other mountings, prepared in the same manner, not a single cell of this kind is found in the phaeodium, and that the latter is composed only of iiTegular pigment-granules. In many Ph^odaria belonging to different families I, like Hertwig, could not find a single true nucleated cell in the phseodium. 1536 THE VOYAGE OF H.M.S. CHALLENGER. A great part of the Ph.eodaria, and usually the bigger forms of Aulacanthida, Cannor- rhaphida, Ccelodendiida, Ccelographida, &c., exhibit a peculiar structure of the larger phseodella, viz., a fine parallel striation (PI. 101, figs. 3, 6 ; PL 102, fig. 1 ; PI. 103, fig. 1 ; PI. 104, figs. 1-3, &c.). In each phseodellum may be counted about ten to twenty such fine parallel stripes (more in the greater, less in the smaller forms) ; and in the ellipsoidal pha3odella the stripes are either transverse rings, perpendicular to their main axis, or ascending obliquely ; they often resemble the convoluted spiral filament of a thread-cell or nettle-cell of an Acaleph. Some- times these parallel transverse stripes are very striking. Another structure is seen in larger phseodella, namely an aggregate or cluster of smaller globules, often of equal size, resembling a small morula. All these minute structures of the phseodella as well as theii' changes in the living Ph^odaria, require a far more extensive examina- tion (by means of strong lenses and different chemical reagents), than I could, unfortunately, devote to them. The physiological signification of the phseodella, therefore, is at present not yet knowTi ; but the general facts quoted above, their constant presence, position, volume, and composition, make it probable that their physiological value in the Ph^odarian organism is very great. The following hypotheses may be taken provisionally into consideration : — A. The phseodella are peculiar symbiontes, or unicellular algse, compar- able to the xanthellse or zooxanthellse of the other Radiolaria. This hypothesis is pro- bably correct for those phseodella which are true nucleated cells ; and the more so, as the majority of Ph^odaria do not exhibit those common yellow xanthellse, which are usually found in the Spumellaria and Nassellaria. It is even possible that the latter are absent in all Ph^odaria. B. The phseodella are dark pigment-bodies, which absorb light and heat in a manner similar to the simple " pigment-eyes " of many lower animals, and may therefore be optical sense-organs of the Ph.eodaria. This hypothesis may be supported by a comparison with the large-ej^ed unicellular Protist, Erythropsis agilis, described by E. Hertwig. C. The phseodella are organs of nutrition of the Ph^odaria and active in their metastasis (" Stoffwechsel "). Regarding them from this point of view, we may suppose that the jahseodella are secreted products which serve for digestion, acting like the bile or the saliva of higher animals. Perhaps they too act like the venomous matter produced in the thread-capsules of the Acalephse. The suggestion that they are mere excretions, or half-digested matters, as Hertwig supposes (" halb assimilirte Nahrungs-bestandtheile," 1879, loc. cit., p. 99) seems less jjrobable. The most important fact illustrating their high signification for the processes of nutrition, digestion and for effecting changes on matter, seems to be the close relation of the phseodium to the astropyle ; the radiate operculum of the latter, and the proboscis arising from it, being constantly covered and completely hidden by the central main mass of the phseodium. REPORT ON THE RADIOLARIA. 1537 The skeleton of the Ph.eodaria is always extracapsular, aud exhibits in the majority of this legion such a characteristic shape, form, aud structure, that these organisms may be easily recognised by it, even apart from the central capsule and the phaeodium. In a few cases, however, the skeleton is so similar to that of some Nassellaria and Spumellaria, that it may be accidentally confounded with it. In general the skeleton of the Ph.eodaria is much larger, and much more highly developed, than that of most other Radiolaria, and exhibits the most wonderful appearances, and the most marvellous complications, which are found in the whole world of Protists, or of unicellular organisms. The varied composition and differentiation of the skeleton alone distinguishes the numerous families, genera, and species of Ph^odaria described in the sequel ; all the fifteen families, however, agree so completely in the structure of the central capsule and the phseodium described, that we may derive them all phylogenetically from a small skeletonless family, the Phseodinida. The chemical composition of the skeleton seems to be, in the majority of Ph.eodaria, somewhat different from that of the other Radiolaria. In a few groups only, especially in the Cannobelida (Dictyocha, Mesocena, &c.), and in a part of the Castanellida and Concharida, the substance of the skeleton seems to be of pure silica, as in the Nassellaria and Spumellaria ; these flinty skeletons, therefore, may be also found fossil. In the majority of Ph^odaria, however, the skeleton does not consist of pure silica, but of an organic silicate ; it becomes more or less intensely stained by carmine, and browned or blacked by fire ; in many cases it even becomes completely burned and destroyed by the prolonged action of heat. This circumstance explains why Ph^^odaria in general are rare in deep-sea deposits, as in the common Radiolarian ooze of the Pacific, and why they are generally absent in fossil deposits. Even the pure Radiolarian rocks of the Barbados, &c., contain only a few Ph^odaria, mainly Dictyochida. According to the different forms of the skeleton, we may divide the legion or sub- class of Ph^odaria into two sublegions, four orders, and fifteen families. Firstly, we may distinguish as two groups the Phaeocystina, without a lattice-shell, and the P hajoc oscina, with a lattice-shell (compare above, p. 5). The Phseocystina comprise three different families, viz., (l) Pheeodinida, without any skeleton (PI. 101, figs. 1, 2); (2) Cannorrhaphida, with an incomplete skeleton, composed of numerous separate, not radial pieces, which are scattered around the capsule in the calymma (PL 101, figs. 3-14; PI. 114, figs. 7-13), and (3) Aulacanthida (PL 102-105), with an incom- plete skeleton, composed of numerous hoUow radial tubes, which pierce the calymma and come in contact by their proximal ends with the surface of the central capsule. The Phseocoscina, or the Ph.^odaria with a lattice-shell (embracing the great majoi'ity of the whole legion) exhibit three principal differences in the shape of their shell, and from these we distinguish the three following orders ; (A) Phseosphseria, with a spherical, not bivalved shell (rarely of an ellipsoidal or lenticular, or another (ZOOL. CTTAT.L. EXP. — PART XL. — 1886.) Kr 193 1538 THE VOYAGE OF H.M.S. CHALLENGER. modified form), without a shell-mouth or a peculiar constant large opening on the lattice-shell ; (B) P h 8e o g r o m i a, with an ovate or polyhedral, not bivalved shell (often also of a subspherical, ellipsoidal, or another modified form), constantly provided with a shell-mouth or a peculiar large 023ening on one pole of the main axis of the lattice-shell ; (C) Phaeoconchia, with a bivalved shell, composed of two completely separated, hemispherical, cap-shajaed or boat-shaped valves (a dorsal and a ventral), comparable to that of the Brachiopoda. The P h ge o s 23 h se r i a, or those PniEODAEiA the big shell of which is usually spherical, never bivalved and never j^rovided with a peculiar shell-mouth, comprise a great number of common and large-sized Ph^odaria, which may be arranged into four different families, according to the different structure of the shell — (1) Orospha^rida (PL 106, 107), spherical shell extremely big and robust, composed of a single piece of coarse lattice- work, the thick bars of which are stratified and contain partly a fine axial-canal, meshes of the network usually irregularly polygonal, no astral septa in the nodal points ; (2) Sagosphaerida (PL 108), spherical shell large-sized, but extremely delicate and fragile, composed of a single piece of arachnoidal lattice-work, the thin bars of which are simple solid threads, without axial -canal, meshes of the network always large and triangular, no astral septa in the nodal points ; (3) Aulosphasrida (PL 109-111), spherical shell large-sized, but very fragUe, composed of numerous hollow cylindrical tubes, which are connected (and at the same time separated) by peculiar astral septa in the nodal points, meshes either triangular or polygonal; (4) Cannosphserida (PL 112), spherical shell douljle, composed of two concentric shells which are connected by thin hollow radial tubes, the inner shell simple, solid or fenestrated, with a shell-mouth on the basal pole, the outer shell composed of hollow cylindrical tubes which are connected by astral septa in the nodal points. The structure of this outer shell is the same as in the Aulosphajrida, while the basal mouth of the inner shell brings this family in closer relationshii? to the P h se o g r o m i a. The P h se o g r o m i a, or those PnyEODARiA the shell of which is not bivalved, but provided with a peculiar constant mouth on the oral pole of the main axis, are in general similar to the Nassellaria (Monocyrtida), and may be divided into five different families, viz., (l) Challengerida (PI. 99), shell ovate or subspherical, also often triangular or lenticular, distinguished by a peculiar diatomaceous structure, an exceed- ingly fine tracery of regular hexagonal, very delicate network ; (2) Medusettida (PL 118-120), shell ovate, campanulate or cap-shaped, distinguished by a peculiar alveolar structure, with a corona of peculiar hollow, large, articulated feet around the moutt; (3) Castanellida (PL 113), shell spherical or subspherical, of ordinary simple lattice-work, usually with a corona of simple solid teeth around the mouth ; (4) Circoporida (PL 114-117), shell spherical or polyhedral, with panelled or dimpled surface, distinguished by a peculiar porcellanous structure (numerous thin needles being REPORT ON THE RADIOLARIA. 1,339 embedded iu a punctulate cenient-substauce), with hollow radial spines and with a corona of simple solid teeth around the mouth ; (5) Tuscarorida (PI. 100), shell ovate or subspherical, with smooth sui'face, of the same peculiar porcellanous structure as the Circoporida, but with hollow, very long, tubular teeth around the mouth. The Phgeoconchia are the peculiar and most interesting " Ph^odaria bivalva," diflering from all other Ph.^odaria, and from all known Eadiolaria in general, in the possession of a bivalved lattice-shell, composed of a dorsal and a ventral valve. They maybe divided into three families: (1) Concharida (PI. 123-125), shell with two thick and firm, regularly latticed valves, which bear no hollow tubes and no cupola or galea on their apex or sagittal pole; (2) Coelodendrida (PI. 121), shell with two thin and fragile, scarcely latticed valves, which bear a conical cupola or a helmet-shaped galea on their apex, and hollow branched tubes arising from it (without rhinocanna and frenula); (3) Coelographida (PI. 122, 126-128), shell with two thin and fragile, scarcely latticed valves, similar to those of the Ca3lodendrida, but differing from them in the development of a peculiar rhinocanna or nasal tube upon each valve ; this tube is connected by an odd or paired frenulum with the apex of the galea, and both together contain the phgeodium. The phylogeuetic affinity of the fifteen families enumerated, and the morphological relationship based upon it, form a very difficult problem. The whole legion of Ph^eodaria is proljably monophyletic, in as much as all the families may be derived from a single ancestral group, the skeletonless Phseodinida {PhcBodina and PhcBOColla) ; but at the same time polyphyletic, in as much as probably many families have been derived, indepen- dently one from another, from different branches of Phseodinida ; or in other words, the characteristic malacoma of the Ph^eodaria (the cannopylean central capsule and the ealymma with the phseodium) may be a mouo^ihyletic product, inherited from a single ancestral form ; the manifold skeleton, however, is certainly a polyphyletic product, originatino; from different skeletonless Phseodinida. Among the independent families of Ph/EOBARia, derived directly from skeletonless Phseodinida by production of a peculiar skeleton, may be the following : Cannorrhaphida (PI. 101, probably polyphyletic) Aulacanthida (PI. 102-105), Castanellida (PI. 113), Challengerida (PI. 99), Concharida (PL 123-125), Circoporida (PL 114-117) and Tuscarorida (PL 100). The four families of Phseosphseria (the Orospha^rida, Sagosphserida, Aulosphserida and Cannosj)h8erida (PL 106-112), may be derived perhaps from the Castanellida; and the Medusettida (PL 118-120), have been perhaps derived from the Challengerida. The complicated affinities of these groups are however difficult to explain. The Coelodendrida (PL 121) are probably derived from the Concharida, and the Coelographida (PL 126-128) from the Coelodendrida. The geometrical fundamental form of the shell is in the majority of Ph^odaria monaxonial, corresponding to the main axis of the enclosed central capsule ; the 1540 THE VOYAGE OF H.M.S. CHALLENGER. astropyle of the latter, placed on the oral pole of the main axis, corresponds to the mouth of the shell in all P h se o g r o m i a. In the P h se o s p h se r i a, where no peculiar shell-mouth is developed, the general fundamental form of the shell is usually homaxonial or spherical, often an endospherical polyhedron, rarely eUii^soidal or spindle- shaped (with prolonged main axis), or lenticular (with shortened main axis). The bivalved Phajoconchia have usually either an amphithect shell (with the same fundamental form as the Ctenophora), or a dipleuric, bilaterally symmetrical shell (with a dorsal and a ventral valve, a right and a left parapyle). A small number of Ph^odaria (mainly Circoporida) are remarkable on account of the regular polyhedral form of their shell, the geometrical axes of which resemble crystalline axes and are defined by regular radial tubes; as the octahedral Circoporus (PL 117, fig. 6), the dodecaliecbal Circorrhegma (fig. 2), and the icosahedral Circogonia (fig. l). The sdiceous or silicate bars, which compose the skeleton of the Ph^odaeia, are in the majority hollow tubes, filled up by jelly ; in some other families, however, they are solid rods, as in the Nassellakia and Spumellaria. Such usual lattice-work, composed of solid rods, occurs only in the families Sagosphserida (PI. 108), Castanel- lida (PI. 113), and Concharida (Pis. 123-125). A quite peculiar structure, a diatomaceous tracery of extremely fine and regular hexagonal frames, distinguishes the Challengerida (PI. 99). The hollow cylindrical tubes, which are found in the other families, appear in three different forms, simple, articulate, and provided with an axial thread. Simple hollow tubes, which are neither articulate, nor provided with an axial thread, occur in the Caunorrhaphida (PI. 101) Aulacanthida (PL 102-105), Ccelodendrida (PI. 121, 122), and Ccelographida (PL 126-128). In all these families the hollow cylindrical tubes have a very thin wall and contain a wide cavity, filled only by jelly. The Orosphserida (PL 106, 107), difler in the reduction of the cavity, which becomes very narrow (often rudimentary or lost), whUst the walls of the tubes become extremely thickened and stratified, numerous concentric layers of sUica being disposed one over the other. The hollow cylindrical tubes contain an axial filament, or a thin thread of silica, placed in its axis, in the families Aulosphterida (PL 109-111), Cannosphgerida (PL 112), Circoporida (PL 114-117), and Tusca- rorida (PL 100). Usually the axial filament is connected with the thin wall of the tube by numerous horizontal branches. A quite peculiar structure distinguishes the Medusettida (PL 1 18-120) ; their hollow tubes, extremely prolonged, are articulate owing to the presence of numerous, regular, equidistant transverse septa ; these are pierced by a short tubule, similar to the siphon of the shells of Nautilus ; this remarkable alveolar structure also occurs in the peripheral part of their shell-wall (and sometimes in the whole shell), numerous small polyhedral chambers or alveoles which communicate by small openings, being developed ; they become easdy fidled with air in the dry shell (PL 120, figs. 11-16). REPORT ON THE RADIOLARIA. 1541 The substance of the siliceous or silicated shell-wall is, in the majority of Ph.eodaria, homogeneous and structureless, as in the Spumellaria and Nassellaria ; but sometimes it acquires a peculiar structure. The thickened wall of the hollow tubes in the Orosphserida and in several Aulacanthida (PL 105, figs. 6-10) becomes distinctly stratified, concentric strata being disposed one over the other. A very remarkable structure, diftering from that in all other Radiolaria, is found in the porcellanous shell of the Cii-coporida (PL 114-117), and Tuscarorida (PL 100). The thickened wall of the opaque shell is here composed of a peculiar silicated cement, which encloses numerous very thin and irregularly scattered needles (PL 115, figs. 6-9; PL 116, fig. 3). Dry fragments of these shells, observed by a strong lens, appear finely punctulate, and probably air, entering into these fine porules of the cement, causes the white colour and the calcareous or jjorcellauous appearance of the opaque dry shell. Its surface is smooth in the Tuscarorida (PL 100), panelled in the Circoporida (PL 114-117). The hoUow or solid spines, which arise from the shell of the Ph^odaria, exhibit an extraordinary variety and elegance in the production of different branches, bristles, hairs, secondary spine, and thorns, hooks, anchor-threads, pencils, spathillse, &c. These appendages are developed similarly to those of many Spumellaria, but exhibit a far greater variety and richness in form. They are organs partly for protection, partly for retention of food. They are much more interesting than in other Radiolaria. I. Order PH^OCYSTINA. Skeleton absent or in- complete, composed of numerous single scattered - pieces, without connec- tion. Central capsule placed in the centre of the calymma. II. Order PH^OSPHyERIA. Skeleton a simple or double lattice-shell, not bivalveil, without a peculiar shell- mouth (shell usually spherical, rarely of a modi- fied form, always without peristome). Central cap- sule placed in the centre of the shell-cavity. Syno2:>sis of the Orders and Families of Ph^odaria. Skeleton completely absent, .... Skeleton composed of numerous scattered pieces, not of radial tubes. Skeleton composed of numerous hollow radial tubes, the proximal ends of which are in contact with the central capsule, ...... Shell composed of a simple, non-articulated lattice- plate, without astral septa in the nodal points. Shell composed of numer- ous hollow, tangential cylindrical tubes, which are separated by astral " septa in the nodal points. f Network very robust and coarse, with irregular polygonal meshes ; bars very thick, partly hollow, Network very delicate and fragile, with subregular, triangular meshes; rods very thin, filiform, always solid, Shell articulated, with astral septa, without a simple central shell, Shell double, composed of two concentric shells ; the outer articulated, the inner simple. 1. Ph^odinida. 2. Cannoekhaphida. 3. Aulacanthida. 4. Oeosph^rida. 5. Sagosph^rida. 6. AULOSPH^RIDA. 7. Cannosph^rida. 1542 THE VOYAGE OF H.M.S. CHALLENGER. Synopsis of the Orders and Families of Ph^eodaria — continued. HI. Order PH.^OGROMIA. Skeleton a simple lattice- shell, not bivalved, con- stantly provided with a peculiar large shell- mouth placed on the oral pole of the main axis ; peristome usually surrounded by peculiar feet or teeth. (Shell either spherical or ovate, or of another form). Central capsule excentric, placed in the ahoral half of the shell-cavity. IV. Order PH^OCONCHIA. Skeleton a bivalved lattice- shell, composed of adorsal and a ventral valve which are completely separated (rarely connected by a ligament on the aboral pole). Central capsule enclosed between the two valves. Structure of the shell not porcellanous (without needles imbedded in a punotulate cement-sub- stance). Structure of the shell diatomaceous, with very delicate and regular hexa- gonal pores. No articu- late feet. Structure of the shell alveo- lar, with hollow alveoles between a double plate. A corona of articulated feet around the mouth, . Structure of the shell por- cellanous, with pecidiar fine needles imbedded in a punctulate cement- - substance (a circle of pores around the base of each radial tube). The two valves of the bivalved shell thick and firm, regularly latticed, without a galea or cupola on their apex, and without hollow tubes, The two valves of the bivalved shell very thin and fragile, scarcely lat- ticed, each with a conical cupola or a helmet- shaped galea on its sagittal pole or apex, and with hollow tubes. Galea without rhinocanna or nasal tube, without frenula, . Galea with a rhinocanna or nasal tube, both con- nected by an odd or paired frenulum, 8. Challengerida. 9. Medusettida. Structure of the shell of sim- ple lattice-work, neither diatomaceous nor alveo- lar. No articulate feet, 10. Surface of the shell pan- elled or dimpled (spheri- cal or polyhedral). Peris- tome flat, . .11. Surface of the shell smooth, even (ovate or subspheri- cal). Peristome pro- minent. Castanbllida. CiRCOPORIDA. 12. TUSCARORIDA. 13. CONCHARIDA. 14. CCELODENDRIDA. 15. CCELOGRAPHIDA. Order I. PH.EOCYSTINA, Haeckel (1879). Definition. — Ph^odaria without lattice-shell, either without auy skeleton, or with an incomplete skeleton, composed of numerous single pieces, which are scattered in the calymma without connection. Central capsule placed in the centre of the spherical calymma. REPORT ON THE RADIOLARTA. 1543 Family LXXI. Ph^odinida, Haeckel (PL 101, figs. 1, 2). Phceodinida, Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. 4. Definition. — Ph.eodaria without skeleton. Central capsule with one to three (or more) openings, placed in the centre of the spherical naked calymma. The family P h a3 o d i n i d a is the simplest and most primitive of the Ph^odaria, and diflfers from all the other families of this legion in the complete absence of a skeleton. It bears, therefore, the same relation to the latter as the ThalassicoUida do to the other Spumellaria. The soft body is only composed of the central capsule with the nucleus, and the caljniima with the phasodium. Of course it is quite possible that the skeletonless PnyEODARiA, which we regard here as the ancestral family of that legion, may be either members of other families which have lost their skeleton accidentally, or young Ph^odaria which have not yet developed a skeleton. But in some preparations of the Challenger certain large, well- preserved Ph/EODARia, without any trace of skeleton, are not rare; and since I myself have observed a complete living Phceodina, I have no doubt that they are independent, primordial forms (like Actissa, Jlialassicolla, Cystidium, Nassclla, &c.). Probably also two skeletonless Ph.bodaria belong to this famdy which are figured by R. Hertwig, in 1879, in his Organismus d. Radiol. (Taf. x. fig. 1,11); this author, however, supposed that they had lost their original skeleton. The three species of Phseodinida which are described in the sequel represent two difi"erent genera, Phceodina and Phmocolla, already distinguished in my first note on the Ph^odaria (Sitzungsb. med.-nat. Gesellsch. Jena, 1879, Dec. 12, p, 4). Phceodina is a true Tripylea, and has the usual three openings which occur in the majority of Ph^o- daria, a large astropyle or main-opening on the oral pole of the main axis, and a pair of lateral accessory openings, or parapylse, on the aboral pole. Phceocolla, however, has only a single opening, the astropyle, and agrees therefore with those Ph^odaria which possess no parapylse (Challengerida, Medusettida, Castanellida, &c.). The complete body is in all observed Phaeodinida a small jelly sphere of 1 to 3 mm. in diameter, with a transparent cortical layer and an opaque dark central part. This latter is the phseodium, in which the central capsule is hidden, surrounded on all sides by the gelatinous spherical calymma ; the smooth surface of the latter is spheiical. The centred capside of the Phseodinida (PL 101, figs. 1, 2), is either spherical or spheroidal, somewhat lenticular, slightly depressed in the direction of the main axis. Its diameter is between 0'1.5 and 0"25. Its double membrane exhibits the same structure as in the other Ph^odaria. The thick, double-contoured outer membrane is separated from the thin and delicate inner membrane by a clear space, fiUed up by jelly or by a fluid ; the two are connected in Phceocolla (fig. 1) only at the astropyle, in Phceodina (fig. 2) 1544 THE VOYAGE OF H.M.S. CHALLENGER. they are also connected at the two parapylse. The radiate operculum of the astropyle opens by a tubular prolongation or proboscis, which is very long in the foi-mer, shorter in the latter. The two parapylse of the latter also bear short tubules. The protoplasm, enclosed in the inner membrane, contains numerous small circular vacuoles. The large central nucleus is sometimes spherical or ellipsoidal, at other times spheroidal or lenticular ; it always contains numerous nucleoli. One specimen observed, with two nuclei, was apparently engaged in self-division (fig. 2). The spherical gelatinous calymma, in the centre of which the central capsule is placed, has a diameter of 1 to 2 mm. In the specimen of Phceodina tripylea, which I observed living, it exhibited exactly the same shape as the figure of Dictyocha sta2)edia in PI. 101, fig. 10; the only distinction in this latter being indicated by the pileated pieces of the skeleton on the surface. The jelly-sphere contained numerous roundish or globular alveoles of very different sizes, and between them an areolated network of protoplasm ; the latter has arisen from the outer surface of the calymma in the form of very numerous, radiating, partly branched and anastomosing pseudopodia. The dark and opaque centre of the jelly-sphere is filled up by the granular, blackish-brown phfeodium, which envelops the oral half of the central capsule completely ; it exhibits the same characters as in all the other Ph^odaria. Synopsis of the Genera of Phceodinida. Central capsule with a single opening (an astropyle on the oral pole), . . . 656. Plimocolla. Central capsule with three openings (an oral astropyle and two aboral parapylae), . 657. Plueodina. Genus 656. PhceocoUa,^ Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. 4. Definition. — Phseodinida with a single aperture to the central capsule (an astropyle with radiate operculum, placed on the oral pole of the main axis). The genus PhceocoUa may be regarded as the simplest form of all Ph^odaria, and perhaps as the common ancestral form of this legion. It has no skeleton, and the central capsule exhibits only a single aperture on one pole of the main axis. In this it agrees with the Challengerida, Medusettida, and Castanellida, which have also no parapylse or secondary openings. 1. PhcBocolla primordialis, n. sp. (Pl. 101, fig. 1). Central capsule subspherieal, or somewhat depressed iu the direction of the main axis. The oral pole of the latter exhibits a large astropyle, or a radiate operculum, about as broad as the ^ PhceocoUa = Brown jelly; ^6g, a-jrotSl;. REPORT ON THE RADIOL ARIA. 1587 3. Aulospathis quadnfurca, n. sp. Eadiiil tubes with an inflated ovate terminal knob at the distal end, which bears foiu' crossed, divergent, curved terminal branches. Proximal whorl also rather regular, with a cross of four straight lateral branches. Dimensions. — Length of the tubes 3"0 to 4'0, breadth 0-04 to 0'08 ; branches 0'2 to 0'3. Habitat. — South Pacific, Station 291, depth 2250 fathoms. 4. Aulospathis polymorpha, n. sp. (PL 104, figs. 10-13). Radial tubes with an iiitlated ovate terminal knob at the distal end, which bears a variable number of divergent, curved, iiTCgidar, terminal branches. Usually the majority of the tubes bear three branches, whilst others exhibit two or four, sometimes also five or six. Proximal whorl also very variable and irregular, with two to six, usually three or four unequal branches. Dimensions. — Length of the tubes 2"0 to 4-0, breadth 0-04 to 0'06 ; branches 01 to 0-3. Hahitat. — South Pacific, Station 289, depth 2550 fathoms. Subgenus 2. Aidospathilla, Haeck^l. Definition. — Distal ends of the radial tubes of equal breadth or tajjering gradually, uot inflated, without terminal knobs. 5. Aulospathis diodon, n. sp. Radial tubes without inflated terminal knob, forked at the tapering distal end, with two divergent curved branches of equal size. Proximal whorl cruciate, with four rather equal, crossed, straight, lateral branches (sometimes three or five instead of four in single tubes). Dimensions. — Length of the tubes 2'0 to 2-5, breadth 0'03 to 0'04 ; branches 01 to 0'3. Hahitat. — North Pacific, Station 231, depth 2250 fathoms. 6. Aidospathis triodon, n. sp. (PL 104, fig. 8). Radial tubes without inflated terminal knob, with three divergent, slightly curved, terminal branches. Proximal whorl with a variable number of curved lateral branches, usually also three (often two or four, rarely more). Dimensio7is — Length of the tubes 2 to 3, breadth 0'03 to 0'05 ; branches 0'2 to 0'3. Hahitat. — North Pacific, Stations 250 to 253, depth 2740 to 3125 fathoms. 1588 THE VOYAGE OF H.M.S. CHALLENGER. 7. Aulospathis tetrodon, n. sp. (PI. 104, fig. 9). Eadial tubes without inflated termiual knob, with four crossed, divergent, slightly curved terminal branches. Proximal whorl usually with an irregular cross of four lateral branches (often five or six, rarely two or three instead of the usual four). Dimensions. — Length of the tubes 2-0 to 2-5, breadth 0-03 to 0'04 ; branches 0-2 to O'S. Halitat. — North Pacific, Stations 244 to 245, depth 2775 to 2900 fathoms. 8. Aulospathis hexodon, n. sp. Eadial tubes withoiit inflated terminal knob, with three forked, curved branches at the distal end, so that each tube usually bears six terminal branches; but other tubes of the same specimen bear only three simple or a few irregularly forked branches. Proximal whorl usually with six curved, irregular, lateral branches. Dimensions. — Length of the tubes 2-0 to 3'0, breadth 0'03 to O'OG ; branches 0^2 to 0'5. HaUtat. — AVestern Tropical Pacific, Station 224, deptli 1850 fathoms. 9. Aulospathis furcata , n. sp. Eadial tubes without inflated terminal knob, with a \'ariable number of unequal terminal branches, which are partly simple, partly irregularly forked or branched; the usual number of terminal branches is three or four, more rarely two or five or six. Proximal whorl very irregular, usually with four to six unequal, lateral branches. Dimensions. — Length of the tubes 2'0 to 2'5, breadth 0'03 to O'Oo ; branches 01 to 0'3. Halitat. — Stations 265 to 268, depth 2700 to 2900 fathoms. 10. Aulospathis variabilis, u. sp. (PL 104, figs. 14-17). Eadial tubes without inflated terminal knob, with a variable number of unequal termiual branches, which are constantly sunple, never forked ; the usual number is in the majority of the tubes three or four, often also two, rarely five to eight. Proximal whorl irregular, with a \'ariable number of lateral branches (usually four to six). Dimensions. — Length of the tubes 2-0 to 3'0, breadth O'OS to 0-06 ; branches 01 to 0'3. Habitat. — Central Pacific, Stations 271 to 274, depth 2350 to 2750 fathoms. Genus G70. Aulodendron,^ n. gen. Definition. — A u 1 a c a n t li i d a with a veil of tangential needles, and with radial tiiljcs, which bear numerous, irreguhxrly scattered, lateral and terminal branches. * Avhderuhon = Tubular tree ; ai/Xo;, Itnoi^oy. REPORT ON THE RADIOLARIA. 1589 The genus Aulodendron difters from the other Aulacanthida in the possession of hitcral and terminal branches, which are irreguLarly scattered on the radial tubes and not arranged in regular verticils. The branches are usually short, simple or forked, rarely longer and again irregularly ramified. 1. Aulodendron antarcticum, n. sp. (PI. 105, fig. 5). Eadial tubes cylindrical, more or less curveil, in the inner proximal half smooth and half as broad as in the outer distal half, which is studded with irregularly curved, partly branched spines, arising usually perpendicularly from the tube. The majority of the spines usually simple, the minority forked, with two to four short branches, the largest spines scarcely twice as long as the breadth of the tube. Dimensions. — Length of the tubes 0-7 to 0-9, breadth 0-01 to 0-02 ; length of the branches 0-02 to 0-04. Hahitut. — Antarctic Ocean (Kerguelen), Stations 156 to 159, surface. 2. Aulodendron imcijicum, n. sp. (PL 105, fig. 2). Itadial tubes cylindrical, slightly curved, in the proximal half smooth, in the distal half with scattered lateral branches, which are partly simple, partly forked, about twice as long as the breadth of the tube, and bear at the distal end a spathilla with five to six recurved teeth. The distal end of the tubes bears a spherical knob, which is separated by a deep stricture and armed with a bunch of six to twelve strong conical teeth. Dimensions. — Length of the tubes 1 to 1-2, breadth 0'015 to 0-02 ; branches O'Oo to 0'04 Habitat. — South Pacific, Station 293, depth 2025 fathoms. 3. Aulodendron australe, n. sj). (PI. 105, fig. 3). Eadial tubes cylindrical, straight, thin, smooth in the proximal half, armed with numerous lateral branches in the distal half ; the majority of the branches forked, about as long as the breadth of the tube, with two or three short ramules, each of which bears a spinulate terminal knob. The distal end of the tubes also forked, with two or three divergent branches. Dimensions. — Length of the tubes 1-2 to 1"6, breadth O'Ol to 0'012. Habitat. — South Pacific, Station 289 ; New Zealand, Station 169, surface. 4. Aidodendron atlanticum, n. sp. liadial tubes cylindrical, tapering gi-adually towards the two ends ; smooth and straight in the proximal half, irregularly curved and branched in the distal half, with ten to twenty (rarely more) branches, which arise almost perpendicularly from the tube. The proximal branches are from four to eight times as long as the greatest breadth of the tube, forked, with two or three short ramules ; 1590 THE VOYAGE OF H.M.S. CHALLENGER. the distal branches are much smaller and simple. The distal end of each branch bears a spathilla with four to six short teeth. Dimensions. — Length of the tubes 24 to 3-6, breadth 0-06 to 0-08. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 5. Aulodendron indicum, n. sp. (PI. 105, fig. 1). Eadial tubes cylindrical, irregularly curved, tapering gradually towards the two ends ; smooth in the proximal half, in-egularly branched in the distal half, with ten to twenty or more curved branches. The proximal branches are very large, one-sixth to one-fourth as long as the tube and irregularly ramified ; the distal branches are much shorter, also ramified or simple. All the branches are more or less curved and bear a spinulate knob at the distal end. Dimensions. — Length of the tubes 1-2 to l^S, breadth 0'02 to 0"G3 ; length of the branches 01 to 0-3. Habitat. — Indian Ocean ; Cocos Islands (Eabbe), surface. Order II. PHiEOSPH^EEIA, Haeckel, 1879. Definition. — PHiEODARiA with a simple or double, usually spherical lattice-shell, which is not bivalved and has no peculiar mouth or peristome. Central capsule placed in the centre of the shell. FamUy LXXIV. Orosph^rida, n. fam. (Pis. 106, 107). Definition. — Ph^odaria with a big spherical (sometimes polyhedral or ellipsoidal), very coarse shell, which is composed of thick bars containing an axial canal. Nodal points of the coarse network without astral septa. Meshes of moderate size, irregularly polygonal. Surface of the shell usually with radial spines and pyi-amidal elevations. No peculiar mouth in the shell. Central capsule tripyleau, in the centre of the shell. The family 0 r o s p li as r i d a comprises those Ph^odaria which possess a simjile spherical or polyhedral lattice-shell, composed of hollow, very thick, non-articulate rods, without a peculiar shell-mouth. They agree in the considerable size of the spherical lattice- shell and the absence of a peculiar shell-moiith with the other Phseosphseria, but dift'er from them in the coarse and irregular shape of the massive network, which is composed of irregular polygonal meshes, separated by very thick concentrically stratified rods, containing a fine axial canal. The closely allied Sagosphserida differ from them in the delicate shape of the solid and very thin, filiform rods of the network, and its subregular REPORT ON THE RADIOLARIA. 1591 triangular meshes. The AiilosphEerida dittcr iu the development of the peculiar nodal cavities and astral septa, by which the thin-walled cylindrical tubes *of the articulated network are separated in the stellate nodal points. The Cannosphaerida, closely allied to these latter, also differ iu the articulated network, and further in the possession of an internal concentric shell. The Castanellida are sometimes similar to the Orosphserida, but distinguished by a peculiar large shell-mouth and a network of different shape. The Orosphaerida belong to the biggest Rndiolaria, and the lattice-work of their spherical shell is of a ruder and coarser shape than, iu any of the other families of this class. Nevertheless they have been hitherto perfectly unknown, and were first discovered by the Challenger. We have been able to distinguish in the collection four genera and twenty-seven species. This strange fact ma)^ be explained by the circumstance, that they are in general rare, and restricted to a few localities, and that probably all the species are inhabitants of great depths. Complete shells also are rarely found, whilst broken fragments of their big shells, easily recognisable by the coarse irregular meshes and the thick stratified bars, are met with frequently in the Radiolarian ooze of some Pacific Stations, especially at Stations 265 and 268, at a depth of 2900 fathoms. The lattice-shell of the Orosphserida is usually spherical, or an endospherical poly- hedron (PL 106, fig. 4) ; rarely one axis is somewhat prolonged, so that the shell becomes slightly ellipsoidal (PL 106, fig. 1). Its diameter is usually between 2 and 3, often also between 2 and 1 mm., rarely more than 3, or less than 1 mm. The largest shells observed attained 5 to 6, the smallest 0"5 to 0"6 mm. Their general habit is veiy characteristic, so that they may be easily distinguished from all other spherical lattice-shells, especially from the Castanellida and from the simple Monosphaerida (Cenosphera, Acanthos2)hcera), with which I confounded them in the beginning (hence the first shell observed, figured in 1878, was placed among the Monosph^rida in PL 12). A closer examination of the coarse network and of the peculiar structure of its thick bars always enables one to recognise even small isolated fragments of broken shells. The meshes of the coarse network exhibit in all observed Orosphserida a very irregular form and unequal size ; the majority are usually more or less quadrangular, more rarely they are triangular, pentagonal or hexagonal, very rarely rounded. They are often arranged in parallel rows, which seem to be determined by prominent crests, connecting the bases of the radial spines (PL 12, fig. 1; PL 106, fig. 4, &c.). The diameter of the meshes is usually between 0'05 and O'l, often O'l to 0*2, rarely more than 0'25, or less than 0'025 mm. In Oroplegma, which develops an outer loose, spongy shell around the inner primary shell, the big meshes of the former become much larger and very irregular (PL 107, fig. 1). The coarse bars which separate the large meshes of the u-regular network are very thick and massive, cylindi'ical, usually of unequal thickness, straight or slightly curved, never angular or prismatic. Their diameter is usually between O'Ol and 0"02, rarely 1592 THE VOYAGE OF H.M.S. CPIALLENGEE. more than 0-03 or less than 0-005 mm. Their surface is either smooth or slightly spinulate. Examined in the dry state and by strong lenses, they constantly exhibit a fine, but distinct longitudinal striation, as the expression of concentric stratification. A fine axial canal or central tubule is usually visible in the axis of each rod, and often this axial canal is studded with numerous short lateral branches (PI. 107, figs. 2, 4, 8). But very often the axial canals become rudimentary or lost, or are developed only in a part of the bars (PI. 12, fig. 1). When they are completely developed, the entire network of the shell is drained by a reticulate system of communicating axial canals ; they are probably filled by jelly in the living body. This tubular system never attains that regu- larity and high development which is constantly found in the Aulosphserida ; and the characteristic stellate nodal points of the latter, with their astral septa, are never found in any of the Orospheerida. Moreover the wall of the tubular bars is very thin and struc- tureless in the Aulosphserida, very thick and stratified in the Orosphserida, the enclosed canal very wide in the former, very narrow in the latter. The stratification of the con- centric cylindrical lamellae, which surround the narrow axial canal, is eftected by the gradual dejiosition of the concentric layers, and is very similar to that which is found in the thick spicula of many sponges. The peculiar structure of the bars in the Orosphasrida becomes very distinct if the skeleton be burned, or acted upon by fire for some time ; it then assumes a brown colour and its surface often appears dimpled. Sometimes the concave dimples on the surface of the bars are rather deep and separated by prominent crests (PI. 107, figs. 4, 7). The few genera of Orospha^rida which are here distinguished have all the same structure, are closely allied, and diiFer mainly in the shape of the outer surface of the lattice-sphere. The latter is quite simple and smooth only in Orona. In the common Orosphcera (PL 106, figs. 1-3) it is studded with radial spines. In the most frecpient form, Oroscena, the shell has a pyramidal or tent-shaped elevation on the base of each radial spine, and usually the bases of the neighbouring spines are connected by strong jjromineut crests, the edges of the three- sided or four-sided pyramids (PI. 12, fig. 1 ; PI. 106, fig. 4). This remarkable form is more or less polyhedral, with concave sides, and is similar to the characteristic shells which are represented by Aidoscena among the Aulosphserida, by Sagoscena and Sagoplegma among the Sagosphserida (compare Pis. 108 and 110). The pyramids or tents, however, are in these latter more regularly and distinctly developed than in the Orosphserida. The radial spines which arise from the top of the pyramids are often branched, and the branches become connected to form an outer enveloping secondary shell or a loose spongy framework in Oroplegma (PI. 107, fig. 1). The radial spines of the Orosphaerida never exhibit a constant number or disposition in the individual species ; their usual number is from twenty to sixty. Their form exhibits two different types, which, however, are not sharply separated ; robust club-shaped and slender rod-shaped spines. The rolxist club-shaped spines are usually about as long as EEPORT ON THE RADTOLARIA. 1593 the diameter of the shell ; they are longitudinally striped in the basal part, spinu- late or reticulately dimpled in the distal f)art ; sometimes they are straight, at other times curved or undulate (PL 106, figs. 1-4 ; PI. 107, figs. 4-6). The slender rod- shaped spines are usually longer than the diameter of the shell, cylindrical, more or less curved or even undulate, smooth or thorny, sometimes irregularly branched, and often the branches are all or partly connected (PL 106, fig. 3 ; PL 107, fig. 1). In the majority of the shells observed the radial spines were found to be partly broken oflf. Then- structure is the same as that of the bars of the network ; but the central axial canal and the surrounding concentric lamellae are usually more distinct than in the latter. The central capsule of the Orosphserida lies in the centre of the spherical lattice- shell, surrounded by the voluminous calymma, which fills up its cavity. The form, structure, and size of the central capsule are the same as in the closely allied Aulosphajrida (PL 111, fig. 2). Its diameter is usually about 0"2, or between 0*15 and 0"25, rarely more than 0'3 or less than 1-2. The dark phseodium is of about the same volume as the central capsule, and envelops its oral half with the radiate operculum and the proboscis of the astropyle. The two opposite parapylse are small. I. Subfamily Oronida. Surface of the shell without pyramidal or " tent-shaped elevations. II. Subfamily Oroscenida. Synopsis of the Genera of Orosphcerida. Surface smooth, without radial spines, 671. Orona. Surface studded with simple or branched radial spines, ..... 672. OroupJicera. Pyramids of the surface free, without spongy enTelope, ..... 673. Oroscena. Surface of the shell with numerous pvra- It, ■ -, c ,i j ,^ i , . , , i i. 1 1 1 i- pyramids oi the surface connected by a spongy nudal or tent-shaped elevations. •' , ^ i i .,- , ,, ^ ^"^ [ envelope or an external lattice-shell, 674. Oroplegma. Genus 671. Orona,^ n. gen. Definition. — 0 r o s p h ^ r i d a with a simple spherical or slightly ellipsoidal shell, without pyi-amidal elevations and radial spines. The genus Orona is the simplest of the Orosphaerida, and probably the common ancestral form of this family. The lattice -sheU is a simple fenestrated sphere, some- times slightly ellipsoidal, with prolonged main axis, and bears on its surface neither tent-shaped elevations nor radial spines. It may be confounded with some big forms of Cenosj)hcBra ; it difi'ers, however, in the possession of hollow central canals in the thick bars of the very coarse lattice -plate. 1 Ormia-HiUj or tuberculate shell; ocoijuvti. (ZOOL. CHALL. EXP. — PART XL. — 1886.) Rr 200 1594 THE VOYAGE OF H.M.S. CHALLENGER. 1. Orona maxima, n. sp. (PI. 107, fig. 5). Shell spherical, with very irregular polygonal meshes. Bars of the loose network smooth or slightly spinulate, very thick, with a pinnulate axial canal. Dimensions. — Diameter of the sphere 5-0 to 55, of the meshes 02 to 04, of the bars 001. Habitat. — Central Pacific, Station 265, depth 2900. 2. Orona rohusta, n. sp. Shell spherical, with irregular quadrangular meshes (intermingled with single triangular, pentagonal, and hexagonal meshes). Bars of the coarse network very thick, spinulate. Dimensions. — Diameter of the sphere 3"0 to 3-6, of the meshes 0'05, of the bars 0'012. Habitat. — Central Pacific, Station 268, depth 2900 fathoms. 3. Orona crassissima, n. sp. (PL 107, fig. 7). Shell ellipsoidal, slightly prolonged in the main axis, with irregular polygonal meshes of very different sizes and unequal forms. Bars of the coarse network very thick, thorny and dimpled, their surface being covered with a network of prominent polygonal crests. Dimensions. — Diameter of the sphere 3'0 to 4'0, of the meshes 0'2 to 0'5, of the bars 0"02 to 0-06. Habitat. — South Pacific, Station 289, depth 2550 fathoms. Genus 672. Orosjyhcera,^ n. gen. Definition. — 0 rosphserida with a simple, spherical (sometimes slightly ellip- soidal or polyhedral) lattice-shell without pyramidal elevations, but with numerous radial spines. The genus Orosphcera differs from the preceding Orona, its ancestral form, in the development of simple or branched radial spines. It bears, therefore, the same relation to the latter that Acanthosphcera has to Cenosphcera. In the two latter genera, however, the bars of the network are solid, in the two former hoUow. The species referred to Orospliwra are closely allied and require a further accurate examination. Subgenus 1. Oronium, Haeckel. Definition. — Eadial spines simple, smooth or spiny, but neither branched nor arborescent. 1 Oras^/wim = Sphere with hilly elevations; ofoj, a(pai(>a. REPORT ON THE RADIOLARIA. 159;") 1. OrosphcBra hastigera, n. sp. Radial spines cylindrical, straight, smooth, simple, about as long as the diameter of the spherical shell, and as broad as its smooth bars. Meshes of the network irregularly polygonal, the majority quadrangular, of different sizes. Dimcmions.~—T)mnKiQx of the sphere I'O to 1-2, length of the radial spines 11 to 1-5, middle breadth 0-004. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. 2. OrosphcBva spinigera, n. sp. Eadial spines cylindrical, irregularly curved, thorny, simple, two to three times as long as the diameter of the spherical shell, and as broad as its spiny bars. Meshes of the network irregularly polygonal, the majority pentagonal. DimcnsioTis. — Diameter of the sphere 1-5 to 1-8, length of the spines S'O to 5-0, breadth 0006. Habitat. — North Atlantic, Station 353, depth 2965 fathoms. 3. OrosphcBra fusigera, n. sp. Eadial spines slender, spindle-shaped, straight, smooth, about as long as the diameter of the spherical or slightly ellipsoidal shell, in the thicker middle part five times as broad as the bars, and tapering equally towards both ends. Meshes of the network irregularly polygonal, the majority quadrangular, separated by smooth bars. Dimensions. — Diameter of the shell 1-0 to 1-2, length of the spines 1-2 to 1-6, basal breadth 0-02, middle breadth 01. Habitat. — North Pacific, Station 253, depth 3125 fathoms. 4. Orosphcera foiKolata, n. sp. Eadial spines spindle-.shaped, straight, dimpled, half as long as the radius of the spherical shell and three to five times as thick as the bars. Meshes irregular, polygonal, of very different shapes, separated by dimpled bars. (Similar to Oroscena gegenbauri, PI. 106, fig. 4, but with spherical dimpled shell, without pyramidal elevations.) Dimensions. — Diameter of the shell 2'0 to 2*4, length of the spines 0"05, breadth 015. Habitat. — Central Pacific, Station 267, depth 2700 fathoms. 5. OrosphcBra serpentina, n. sp. (PL 106, fig. 1). EacUal spines cylindrical, dimpled, undulate or curved in a snake-like manner, about as long as the diameter of the ellipsoidal or spherical shell and four to six times as broad as its smooth bars. Meshes very irregular, polygonal. Dimensions. — Diameter of the shell I'O to 1'2, length of the spines 012 to 015, breadth 012. Habitat. — South Pacific, Station 289, depth 2550 fathoms. 1596 THE VOYAGE OP H.M.S. CHALLENGER. 6. Orosphcera horrida, n. sp. (PI. 106, fig. 2). Eadial spines club-shaped, very strong, straight, about as long as the diameter of the polyhedral shell, ovate and smooth in the distal half, slenderly conical, and armed with recurved spines in the proximal half ; their outer third is the thickest, and five times as broad as the smooth bars of the coarse network. Meshes of the latter irregularly quadrangular. Dimensions. — Diameter of the shell 1-2 to I'G, length of the spines 1-2 to 2'0, breadth 0-2. Habitat. — South Pacific, Station 291, depth 2250 fathoms. 7. Orosj)h(Bra clavigera, n. sp. Eadial spines club-shaped, thickened towards the distal end, more or less curved, spinulate, about as long as the diameter of the spherical shell ; in the distal third four to six times as broad as the spinulate bars. Meshes irregularly polygonal, the majority pentagonal. Dimensions. — Diameter of the shell 2'0 to 2-5, length of the spines 1"8 to 2-2, breadth 0'16. Habitat. — Central Pacific, Station 263, depth 2650 fathoms. Subgenus 2. Orothamnus, Haeckel. Definition. — Eadial spines branched or arborescent. 8. OrosphcBra ramigera, n. sp. Eadial spines cylindrical, spinulate, straight, about twice as long as the diameter of the spherical shell and as thick as its spinulate bars. Numerous simple spinulate branches, straight or slightly curved, and two to four times as long as the meshes, are irregularly scattered, and arise nearly perpendicularly from the bars. DiTiiBTisions. — Diameter of the shell 2-0 to 2-2, length of the spines 4 to 5, breadth 0'05. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 9. Orosphcera fur cata, n. sp. Eadial spines cylindrical, smooth, irregularly curved, about as long as the radius of the spherical shell and as thick as its smooth bars, forked at the distal end, with two or three terminal branches of various lengths. Meshes irregularly polygonal (the majority hexagonal). Dimensions. — Diameter of the shell 1-2, length of the spines 07, breadth 0-03. Habitat. — Indian Ocean, Madagascar (Eabbe), surface (?). 10. Orosphcera confiuens, n. sp. Eadial spines cylindrical, smooth, irregularly curved, two to three times as long as the diameter of the polyhedral shell, twice as broad as its smooth bars, bearing numerous irregular, lateral REPORT ON THE RADIOLARIA. 1597 branches, which are partly confluent and fenestrated (similarly as in PI. 107, fig. 1), but not forming an outer lattice-shell. Meshes irregularly polygonal. Limensioiis. — Diameter of the shell o'3, length of the spines 6 to 9, breadth 0'03. HaMtat. — Tropical Atlantic, Station 347, depth 2250 fathoms. 11. Orosphcera arborescens, n. sp. (PI. 106, fig. 3). Orothamnus arborescens, Haeckel, 1881, Atlas, loc. cit. Radial spines cylindrical, rough, more or less curved, somewhat longer than the diameter of the subspherical or slightly ellipsoidal shell, and at the thicker base three times as broad as its smooth bars, bearing numerous irregularly branched and curved, sometimes confluent, lateral branches. j\Ieshes irregularly quadrangular. Dimetisions. — Diameter of the shell 1'2 to 1-6, length of the spines 1-5 to 2'2, breadth 0'06. HaUtat. — South Atlantic, Station 335, depth 1425 fathoms. Geuus 673. Oroscena,^ n. gen. Definition. — 0 r o s p h se r i d a with a simple, polyhedral or subspherical lattice- shell, and with numerous pyramidal elevations on its surface, the top of which bears a radial spine. The genus Oroscena differs from the preceding Orosphcera in the possession of numerous pyramidal or tent-shaped elevations, each of which bears on its top a radial spine. It exhibits therefore the same relation to the latter that Sagoscena does to Sagosphcera and Auloscena to Aulosphcera. The bases of the radial spines are usually connected by prominent concave crests, the edges of the pyramids. The species described of Oroscena seem to be very variable and transformistic. Subgenus 1. Oroscenium, Haeckel. Definition. — Radial spines simple, smooth or spiny, but neither branched nor forked. 1. Oroscena gegenhauri, n. sp. (PL 106, fig. 4). Radial spines club-shaped, about half as long as the radius of the shell, cylindrical and finely sulcata in the basal third, ovate and elegantly dimpled in the distal two-thirds. The bases of the radial spines are connected by prominent concave crests, which form the edges of the polyhedral shell. Meshes irregularly polygonal, the majority quadrangular, separated by denticulate bars. 1 Oroscena = Shell witli tent-ahaped elevations ; ogoj, ff«n»ij. 1598 THE VOYAGE OF H.M.S. CHALLENGER. Dimensions. — Diameter of the shell (without spines) 1'2 to 1-8, of the meshes 0-04 to 01; length of the spines 0"3 to 0'5. Habitat— Q%niv!i\ Pacific, Station 268, depth 2900 fathoms. 2. Oroscena miilleri, n. sp. (PL 107, fig. 8).^ Radial spines club-shaped, very similar to that of the preceding species, but much larger, about as long as the radius of the shell. Meshes irregularly polygonal, the majority pentagonal, separated by smooth bars. Dimensions. — Diameter of the shell 2-0 to 2'4, length of the spines I'O to 1"2. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 3. Oroscena cuvieri, n. sp. (PL 107, fig. 6). Eadial spines club-shaped, compressed and smooth in the proximal half, spindle-shaped and dimpled in the distal half, about as long as the radius of the shell. Meshes irregularly polygonal, the majority hexagonal, separated by denticulate bars. Dimensions. — Diameter of the shell I'o, length of the spines 0'8. Habitat. — South Pacific, Station 289, depth 2550 fathoms. 4. Oroscena hcerii, n. sp. (PL 107, fig. 4). Radial spines nearly spindle-shaped, undulate, tapering from the thicker middle towards both ends, coarsely dimpled, about one-third as long as the radius of the shell. Meshes irregularly polygonal, the majority pentagonal, separated by spinulate bars. Dimensions. — Diameter of the shell 3'2, length of the spines I'O to r2, breadth 0"1. Habitat. — North Pacific, Station 244, depth 2900 fathoms. 5. Oroscena ivolffii, n. sp. Radial spines cylindrical, spinulate, more or less curved, longer than the diameter of the shell and about twice as broad as its bars. Meshes irregularly polygonal, of very variable form and unequal size, separated by smooth bars. Dimensions. — Diameter of the .shell 2'5, length of the spines 3'0 to 3'5, breadth 0"02. Habitat. — Indian Ocean, Zanzibar (Pullen), depth 2200 fathoms. Subgenus 2. Orodendrum, HaeckeL Definition. — Radial spines branched or arborescent. 1 In the plate the number is omitted by mistake. The figure is above in the middle. EEPORT ON THE RADIOLARIA. 1599 6. Oroscena huxleyi, n. sp. (PI. 12, ligs. 1, la). Eadial spines cylindrical, obliquely ascending and irregularly curved, about as long as the diameter of the shell and somewhat thicker than its thorny bars. A variable number of short, irregular, partly simple, partly forked, lateral branches arises from the spines. Meshes of the network very irregular, partly solid, partly hollow (fig. la*), the majority quadrangular. This species, the first observed form of Orospha-rida (captured the 21st February 1873 at Station 5), was at the beginning of my observations, in 1876, and when I had no knowledge of the central capsule, erroneously regarded by me as a gigantic Sphreroid (of the Monosphsrida) and therefore placed in PL 12. The long branched spines, afterwards observed complete in another specunen, were broken off in the specimen first figured. Bimcnsimis. — Diameter of the shell 2'0 to 2 '5, length of the spines 2 to 3 mm., breadth 0'03. Habitat. — North Atlantic (west of Canary Islands), Station 5, depth 2740 fathoms. 7. Oroscena darwinii, n. sp. Eadial spines cylindrical, irregularly curved and branched, about twice as long as the diameter of the shell ; the branches are all again ramified and partly confluent (as in PI. 107, fig. 1). The branches and the bars of the network are of equal breadth, smooth (not thorny as in the similar preceding species). Meshes rather subregular, quadrangular. Dimensions. — Diameter of the shell 2"4 to 2'8, length of the spines 4 to 5 mm., breadth 0"015. Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 8. Oroscena duncanii, n. sp. ? Sexadineltida didyonina, Martin Duncan, 1881, Journ. Eoy. Micr. Soc, p. 1 75, pi. iii. figs. 4, 6. Eadial spines cylindrical, thorny, arborescent, somewhat shorter than the diameter of the shell, with ii-regular ramified branches (similar to Orosphwra arborcscens, PI. 106 fig. 3). The size and ramification of the arborescent spinulate branches decrease towards the apex. The thicker branches are from two to three times as broad as the spinulate bars of the network. Meshes of the latter irregular, the majority c^uadrangular. Dimensions. — Diameter of the shell 3'2, length of the spines 3'5 to 4'5, breadth 0"02 to 0'3. Habitat. — South Atlantic, Station 318, depth 2040 fathoms ; coast of Portugal, 1095 fathoms. Genus 674. Oroplegma,^ n. gen. Definition. — 0 rosphgerida with a spongy, spherical or slightly polyhedral lattice -shell, which is enveloped by a loose spongy framework and bears numerous radiJil spines. The genus Orojylegma differs from the other Orosphasrida in the development of an external lattice-work envelopmg the internal primary shell, and produced by the union 1 Oro2degma='H.i]lj shell of framework; ojoj, ■r'hiYfioi. 1600 THE VOYAGE OF H.M.S. CHALLENGER. of the branches of the radial spines. This outer shell is either a simple lattice-plate (comparable to the cortical shell of Diplos2')hcBra), or a spongy framework (as in Rhizo- plegma). Subgenus 1. Oroplegmnim, Haeckel. Definition. — External shell a simple fenestrated lamella, forming an outer concentric lattice-sphere around the inner primary shell. 1. Oroijlegma diplosphaera , u. sp. (PI. 107, fig. 1). Eadial spines slender, cyhndrical, smooth, more or less curved, about twice as broad as the smooth bars of the network. External shell a simple irregular lattice-sphere, with loose polygonal meshes, which are on an average three to four times as broad as the irregular meshes of the internal shell. The free prominent parts of the radial spines are irregularly branched, very long, with partly confluent branches. Dimensions. — Diameter of the inner sphere 1'5 to 2-0, of the outer 2 '5 to 3'0 ; length of the free spines V2, breadth 0'04. Habitat. — Central Pacific, Station 265, depth 2900 fathoms. 2. Oroplegma sptinulosum, n. sp. Eadial spines slender, cylindrical, thorny, more or less curved, very similar to those of the preceding species ; the shell also much resembles that of Oroplegma perplexum. It differs from the latter in the more regular fenestration of both shells, and mainly in the shape of the bars and the spine-branches, which are all spinulate and densely studded with small conical thorns. Dimensions. — Diameter of the inner sphere 1"5 to 2-0, of the outer 2"5 to 3"0 ; length of the spines 1'2, breadth 0-03. Hahitat. — Central Pacific, Station 268, depth 2900 fathoms. 3. Oroplegma velatum, n. sp. Eadial spines stout, cylindrical, somewhat club-shaped, spiny, slightly curved, about three to four times as broad as the thorny bars of the network. External shell a simple lattice-sphere with irregular polygonal meshes, which are for the most part pentagonal and about four times as broad as the polygonal meshes of the inner shell. The free prominent parts of the radial spines are thickened, club-shaped, and about as long as the radius. Dimensions. — Diameter of the inner sphere2-0 to 2-4, of the outer 2-8 to 3-6 ; length of the free spines 0-5 to 0-7, breadth 012 to 0-15. Habitat. — Tropical Atlantic, Station 338, depth 1990 fathoms. REPORT ON THE RADIOLARIA. 1601 Subgenus 2. Orodictyum, Haeckel. Definition. — External shell a complex framework, forming an outer spongy envelope around the inner primary shell. 4. Oroplegma spongiosum, n. sp. (PL 107, fig. 3). Eadial spines stout, cylindrical, spinulate, slightly curved, three to tive times as broad as the inner rough bars. External shell witli pyramidal elevations, forming a loose spongy framework, the irregular polygonal meshes of which are two to five times as broad as those of the enclosed internal shell ; the thickness of the spongy envelope equals about half the radius of the inner sliell. External free prolongations of the radial spines about equal to the radius. Dimensions. — Diameter of the inner sphere 2 to 2"5, of the outer 3 to 35 ; length of the free radial spines 0'5 to 2-0, breadth 01. Edbitat — North Pacific, Station 241, depth 2300 fathoms. 5. Oroplegma giganteum, n. sp. (PI. 107, fig. 2). Eadial spines slender, cylindrical, spinulate, irregularly curved, about twice as broad as the spinulate tubidar bars of the network (fig. 2). External shell an irregitlar, loose, spongy framework, the polygonal meshes of which are three to six times as broad as the rounded irregidar meshes of the inner shell ; the tliickness of the spongy envelope about equals the radius of the inner shell. External free prolongation of the radial spines irregularly branched. Dimensions. — Diameter of the inner sphere 3"2 to 3-5, of the outer 5'4 to 6'6 ; length of the free spines 1"4 to I'o, breadth 0"03. Habitat. — Tropical Atlantic, Station 347, depth 2250 fathoms. Family LXXV. SAGOSPH.i;RiDA, n. fam. (PL 108). Definition. — Ph^odakia with a large spherical (or sometimes polyhedral), very delicate shell, which is composed of solid, very thin and long threads. Nodal points of the arachnoidal network without astral septa. Meshes large, triangular. Surface of the shell usually armed with radial spines and often studded with pyramidal elevations. No peculiar mouth in the shell. Central capsule tripylean, in the centre of the shell. The family Sagosphserida comprises a rather large number of common and widely distributed Ph^odaria, which in respect of the special form and differentiation of the shell exhibit the greatest similarity to the common Aulosphserida, but diff'er essentially from them in the peculiar structure of the network. This is not composed of stout hollow cylindrical tubes, but of solid, very thin threads ; and these fine arachnoidal (ZOOL. CHALL. EXP. — PAKT XL. — 1886.) El 201 1602 THE VOYAGE OF H.M.S. CHALLENGER. threads are simply united or confluent at the nodal points, and are not connected by a radial or stellate septal junction, as in the Aulosphserida. There are, therefore, neither astral septa nor a nodal cavity in each nodal point. The delicate shape of the thin and fragile threads separates the Sagospha^rida from the closely allied Orosphterida, the thick bars of which contain a central axial canal and exhibit a concentric structure. Another diff'er- ence between these two similar families is indicated by the form of the meshes of the network, which are constantly triangular in the Sagosphserida, but irregularly polygonal or quadrangular in the Orosphserida. The general habit of these two families, however, is very difi'erent, since the big and stout spheres of the Orosphaerida are the coarsest and rudest spherical shells of all Eadiolaria, whilst the fragile and delicate spheres of the Sagosphserida represent the finest and most tender in the whole class. The spherical lattice-shell of the Sagospheerida has a considerable size, its diameter being usually between one and three millimetres, rarely less or more. Some species are very common and widely distributed, usually accompanying the common Aulosphserida ; very frequently the similar shells of the two are found interwoven. But in spite of this frequency and visible size, the Sagosph^rida have hitherto almost completely escaped the attention of observers. The main cause of this strange fact may be their extreme delicacy and fragibility, so that complete and intact shells occur very rarely, the majority being more or less broken and incomplete. It seems that only two species of Sagosphaerida have been hitherto observed. The first form described is Sagmarium trigonizon, observed by me in 1859 living at Messina, and figured in 1862 in my Monograph as Dictyosoma trigonizon (Taf xxvi. figs. 4-6), but afterwards called Spongodictyutn trigonizon (loc. cit., p. 459). I supposed at that time (now twenty-five years ago), that this remarkable and in many respects distinct form might belong to the Spongospheerida, and that an internal, triple, spherical lattice- shell, found entangled in its spongy framework, might be its central "medullary shell." But at present, having found many shells of different Eadiolaria accidentally entangled in the arachnoidal framework of various Sagos^jhajrida, I think it much more probable, that that " triple medullary shell," composed of three simple concentric lattice-spheres, was really a species of Plegmosphcera or Actinomma, accidentally entangled in the arachnoidal spongy framework of Sagmarium. This is the more probable, as I had observed very frequently at Messina, in 1859, fragments of that framework, but only once the triple lattice-shell which I supposed to be the "triple medullary shell" of the former. The peculiar structure of the loose framework, its very large triangular meshes and thin arachnoidal bars, partly provided with cruciate verticils {loc. cit, Taf. xxvi. figs. 4, 5) have been very frec[uently observed by me during the last ten years in various Sagosphaerida (PniEODARiA), but never in any true Sphseroidea (Spumellaria). The second species of Sagosphserida hitherto observed, is Sagoscena gracilis, described and figured in 1879 by Richard Hertwig as Aulosplmra gracilis (Organism. REPORT ON THE RADIOLARIA. 1G03 d. Radiol., p. 91, Taf. ix. fig. 4). He too observed oidy fragments of destrbyed and incomplete shells, and was led by their striking similarity to fragments of Aulosphcera elegantissima to unite it with the genus AuIos2)h(Bra. But the accurate description and the figure given hj him of the fragments observed leaves no doubt that it was a true Sagoscena. In the collection of the Challenger the Sagosphaerida are so common and so richly represented, that we may describe here not less than seven genera and thirty-three species, but this may be a small part only of the numerous species of this family, which seems to be widely distriljuted over all oceans, in the Arctic and Antarctic as well as in temperate and tro^iical zones. The majority are inhabitants of the surface, but a few species have been found oulj- in deep-sea soundings. A striking fact is their usual association ^\'ith the similar Aulosphserida. The majority of shells of l^oth families were found entangled in one another. The shell of all Sagosphjerida seems to lie spheiical or nearly spherical in the complete state ; but complete spheres can be observed only very rarely, and it is not impossi1)le that deviations from the spherical form exist just as in some Aulosphserida {e.g., the lenticular Aidojihaciis and the spindle-shaped Aulatractus). The diameter of the spheres usually seems to be between 1 and 2, often also 3 millimetres ; very rarely shells occur which are less than 1 or more than 3 (4 or 5) millinietres. The siliceous network or lattice-work of the Sagosphgerida exhibits a very character- istic shape, and this enables one to distinguish it at first sight from aU the other Radiolaria. It is constantly composed of triangular, very large meshes, which are separated by very thin and delicate, flexible and elastic bars. With respect to the arrangement of these meshes we distinguish two difi"erent subfamilies ; in the Sagenida the wall of the spherical sheU is very thin and composed only of a simple lattice-plate ; in the Sagmarida the wall is thickened and spongy, with a complete wicker-work of threads, interwoven in difierent dii-ections. The typical triangular form of the large meshes is usually regular or subregular in the' fenestrated Sagenida, more or less irregular in the spongy Sagmarida. In many cases, however, iiTegular triangles also occur in the former, and regular triangles in the latter subfamily. Very rarely irregular polygonal meshes are found in a part of the network, small connecting bars being developed accidentally between two neighbouring sides of the triangles. The diameter of the meshes is usually between 0"1 and 0'2 mm., often also greater, between 0*2 and 0'3, rarely smaller, 0"05 to 0"09 mm. The triangular meshes of the Sagosphserida are therefore on an average ten times as large as the usual meshes in the network of the common Sphseroidea. The filiform bars, or the thread-shaped, very long and thin rods between the triangular meshes, are scarcely less characteristic of the Sagosphserida than the form and size of the meshes. Their length is usually between O'l and 0*2 mm., often also 1604 THE VOYAGE OF H.M.S. CHALLENGER. from 0-2 to 0-3 mm., whilst theii- tliickuess is only 0-002 to 0*004 mm., often it is less than 0-001, rarely more than 0-005 mm. The nodal points of the network, in which six threads are usually united, are more or less thickened, often stellate (PI. 108, figs. 9, 12, &c.). Sometimes they are pierced by a central pore. The thin threads are constantly cylindrical, never edged or prismatic, very elastic and flexible ; usually they are perfectly smooth, rarely spiny or thorny, sometimes provided with scattered cruciate verticils of lateral branches, as in Sagena crucifera and in the first described form of this family, Sagmarium trigonizon (compare my Monograph, 1862, Taf. xxvi. fig. 5). The surface of the spherical shell is smooth only in two genera of Sagosphserida, in Sagena and Sagmarium (PI. 108, figs. 2, 8). In the five other genera it is covered either with radial spines, arising from the nodal points of the network, or with peculiar cortical pyramids or tent-shaped elevations (PI. 108, figs. 1, 3—6, &c.). These pyramids are of the same characteristic shape as in the similar Auloscena among the Aulosphserida (PI. 110, fig. l) ; usually, however, they are less regular than in the latter. The pyramids or tents are usually six-sided, often, however, they are also four- sided or three-sided, more rarely five, seven or more sided. The edges of the pyramids ai'e formed by filiform bars similar to those which compose the original lattice-work of the Sagosphaerida. The cavity of the pyramids is quite simple in Sagoscena (figs. 1, 5, 6), whilst in Sagenoscena and Sagoplegma a radial column arises in its axis, the thickened axial rod (figs. 3, 4, 10). The radial spines, which arise either from the tops of the pyramids or from the nodal points of the network, exhibit in the Sagosphserida a variety and elegance similar to the closely allied Aulosphgerida. Sometimes a single radial spine arises in each nodal point or at the top of each pyramid (figs. 3, 4, 10) ; at other times two, three, or four (rarely more) divergent spines (figs. 6-9, 12, 13). These are rarely quite simple, usually provided with lateral and terminal branches. The lateral branches are either scattered irregularly, or regularly disposed in elegant verticils, each of which is usually composed of three or four short branches (PL 108, figs. 9, 13). The terminal branches form either a similar verticil, or a bunch or corona, composed of numerous radial secondary spines. The distal ends of the terminal as well as of the lateral branches are rarely simple, usually they are provided with a spinulate knob or with an elegant spathilla (PI. 108, figs. 3, 9, 13). The central capsule of the Sagosphserida is comparatively small, as it also is in the Aulosphserida and Orosphserida. Its diameter is usually about one-third or one-fourth that of the enveloping shell, between 0-2 and 0-3, often only 0-12 to 0-18, rarely more than 0*3 mm. It is surrounded on the oral half by a red or dark phseodium and separated from the inner surface of the shell by the voluminous calymma. The subspherical nucleus is usually about half as broad as the capsule. The three openings of the latter, the large tuljular astropyle and the two opposite lateral parapylse, exhibit the same shape REPORT ON THE RADIOLARIA. 1605 as in the closely allicil Aulospliajrida (PI. Ill, fig- 3). The pseudopodia arising from the eenti'al capsule form a loose network in the calymma, and proceed over its surface as numerous delicate radial filaments, often supported by the radial spines. I. Subfamily Sagonida. Wall of the spherical shell composed of a simple lattice- plate, with or without pyra- midal elevations. II. Subfamily Sagmarida. "Wallof thespherical shell spongy, com- posed of an irre- gular complicated wicker-work Syno2)sis of the Genera of Sagosphcerida. Surface of the spherical shell i No radial spines, surface smooth, smooth or spiny, without -I pyramidal elevations. ( Radial spines in the nodal points, » f Pyramids without internal axial Surface of the spherical shell j rod, .... covered with pyramidal \ or tent-shaped elevations. ] Pyramids with an internal radial [ axial rod, Surface of the spherical shell smooth or spiny, without pyramidal elevations Surface of the spherical shell covered with pyramidal elevations. Surface smooth, without radial spines, Surface studded with radial spines, j Pyramids on the top with a radial -; spine or a bunch of divergent ( spines, 675. Sagena. 676. Sagospha^ra. 677. Sagoscena. 678. Sagenoscena. 679. Sagmarium. 680. Sagmidium. 681. Sagoplegma. Subfamily 1. Sagenida, Haeckel. Definition. — Sago sp h a3r id a with a delicate spherical shell, the thin wall of which is composed of a simple lattice-plate, not spongy. Genus 675. Sagena,^ n. gen. Definition. — S agosphserida with a delicate spherical shell, the thin wall of which is composed of a simple smooth lattice-plate, without i-adial spines. The genus Sagena is the simplest of the Sagosphaerida and may be regarded as the common ancestral form of this familj^ The delicate wall of the simple spherical lattice- shell is composed of large, regular, or subregular, triangular meshes, the nodal points of which bear no radial spines. It agrees therefore perfectly with ^itZajw, and differs from this simplest form of Aulosphserida only in the structure of the skeleton, which is composed not of hollow articulated tubes, but of very thin solid threads. The skeleton may therefore also be confounded with Cenosjyhcei-a, but the central capsule of this latter is " peripylean," with numerous fine pores in the entire wall, whilst that of Sagena is " tripylean," having the proboscis of all Ph^odaria. 1 iSa5feno= Drag-net; aay/,r/i. 1606 THE VOYAGE OF H.M.S. CHALLENGER. 1. Sagena ternaria, n. sp. (PI. 108, fig. 8). Network subregular, with equilateral triangular meshes, intermingled with single irregular meshes (fig. 8). Bars of the network smooth, its nodal points solid, not pierced. Dimensions. — Diameter of the spherical shell 1-5 to 2-5, length of the bars 01 to 0-2, breadth 0-002 to 0-005. Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface. 2. Sagena pertusa, n. sp. Network subregular, with nearly equal triangular meshes. Bars of the network smooth, its nodal points pierced by a circular hole. Dimensions. — Diameter of the shell 1-2 to 1-8, length of the bars 0-2 to 0-25, breadth 0-003. Habitat. — Central Pacific, Stations 270 to 274, surface. 3. Sagena triangiila, n. sp. Network very regular, with equilateral triangular meshes. Bars of the network spinulate, like those of Sagojjlcfivia sjjimdosa (PI. 108, fig. 14), its nodal points solid, not pierced. Dimensions. — Diameter of the shell 2-2, length of the bars 0-25, breadth 0-004. Habitat. — South Atlantic, Station 325, surface. 4. Sagena crucifera, n. sp. Network more or less irregular, with unequal triangular meshes. Bars of the network studded with scattered, rectangular, minute crosses, arising perpendicularly, each cross composed of four small equal bars. Nodal points partly solid, partly pierced by a hole. Network very similar to that of Dictyosoma trigonizon, figured in my Monograph, Taf. xxvi. figs. 4, 5. Dimensions. — Diameter of the shell 1-5, length of the bars 0-1 to 0-2, breadth 0-003. Hahitat. — Mediterranean, Atlantic, Canary Islands, Station 353, surface. Genus 676. Sagosphcera,^ n. gen. DeJtnitio7L — S agosphserida with a delicate spherical shell, the thin wall of which is composed of a simple lattice-plate, and bears on its nodal points radial spines. The genus Sagosphcera differs from the preceding Sagena, its ancestral form, in the development of radial spines on the nodal points of the simple delicate lattice-sphere. It exhibits therefore the same relation to the latter as AulosjihcBva bears to Aularia. ' SojfospfetBra = Spherical armour ; aiyn, (i(pa'ina. REPORT ON THE RADIOLARIA. 1607 The regular or subregular triaugular meshes of the lattice-sphere are separated in Sagosplicera by solid, very thin threads, in the similar Aulosiohcera, however, by thicker hollow tubes. The genus Sagosplicera may be divided into two subgenera : — Sagosph(Brella with a single radial spine at each nodal point of the network, and SagosphcBroma with a l)unch of two to four or more divergent radial spines. 1. Sagosphmra trigonilla, n. sp. Eadial spines simple, straight, smooth, about as long as the smooth bars of the network, a single one at each nodal point. Meshes very regular, of equal size, equilateral triangular. (Similar to the common Aulosplictra trigonojM.) jDimenslons. — Diameter of the sphere 12 to 1'8, length of the bars O'l to 0'2, breadth 0"002 to 0-006. Habitat. — CosmopoUtan ; Mediterranean, Atlantic, Pacific, surface. 2. Sagosphcera penicilla, n. sp. (PI. 108, fig. 10). Eadial spines straight, stout, a single one at each nodal point, twice as thick, but of the same length as the smooth bars of the network, armed at the distal end with a brush of numerous thin radial bristles. (Very similar to Sagcnoscoia pencillata, but without pyramidal elevations on the surface of the sphere.) DiTnensions. — Diameter of the sphere I'D to 1'5, length of the bars Ol to 015, breadth 0'002 to 0-004 Habitat. — Antarctic Ocean, Station 154, surface. 3. SagosphcBra verticilla, n. sp. Eadial spines slender, slightly curved, a single one at each nodal point, armed with three to five cruciate verticils, each of which is composed of four crossed lateral branches with spinulate terminal knobs (similar to Sagmidium crucicornc, PL 108, fig. 9), but with a spherical shell, having a simply latticed, and not a spongy wall. Dimensions. — Diameter of the sphere 2'0 to 2'5, length of the bars O'l to 0'2, breadth 0'002. Habitat. — Xorth Pacific, Station 256, surface. 4. Sagosphcera furcilla, n. sp. (PL 108, figs. 11, 11a). Eadial spines short, spinulate, with a spiny terminal knob (fig. 11a), two or three arising from each nodal point of the network in divergent directions, only one-third or one-fourth as long as its smooth bars. Meshes more or less irregular, triangular. Dimensions. — Diameter of the sphere 2-2, length of the bars 0'2 to 0'3, breadth 0'004. Habitat. — South Pacific, Station 293, depth 2025 fathoms. 1608 THE VOYAGE OF H.M.S. CHALLENGER. 5. Sagosphcera coronilla, n. sp. Eadial spines slender, smooth, three to six arising from each nodal point of the network in . divergent directions, about as long as its smooth bars, crowned at the distal end with a bunch of twenty to thirty radial terminal branches, and provided with a spinulate knob at the distal end (similar to Sagcnosccna stcllata, PL 108, iig. 3). Dimensions. — Diameter of the sphere S'O, length of the bars 01 to 0-2, breadth 0002. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 677. Sagoscena,^ n. gen. Definitioti. — S agospliasricla with a delicate s]3herical shell, the thin wall of which is composed of a simple lattice-plate and covered with numerous pyramidal elevations ; each pyramid bears on its top one or more radial spines, but has no axial rod in its radial axis. The genus Sagoscena, and the following closely allied Sagenoscena (l)oth very common and widely distributed), exhibit a peculiar and very remarkable structure of the delicate lattice-shell, similar to that which Auloscena represents among the Aulo- sphserida. The surface of the simple spherical lattice-shell is covered with numerous pyramidal or tent-shaped elevations. These elegant and delicate pyramids are, how- ever, in Sagoscena usually not so regular as in the similar Auloscena ; the edges of the pyramids are in the latter hollow cylindrical tubes, in the former thin solid threads. The top of each pyramid usually bears a bunch of apical sj)ines. 1. Sagoscena castra, n. sp. (PI. 108, fig. l). Pyramids subregular, of equal size and similar form, usually three-sided, crowned at the top with three divergent apical spines, which alternate with the three edges of the pyramids and bear a small spinulate terminal knob. (Some four-sided and single five-sided pyramids are often inter- mingled with the three-sided.) Dimensions. — Diameter of the sphere 17 to 2'3, length of the bars 0'2 to 0'25, breadth 0*008. Habitat. — South-Eastern Pacific, Stations 295, 296, surface. 2. Sagoscena tentorium, n. sp. (PI. 108, fig. 6). Pyramids subregular, of equal size and similar form, usually four-sided, crowned at the top with three divergent apical spines, which are trifurcate at the distal end. (Some three-sided and five-sided pyramids are often intermingled with the four-sided.) Dimensions. — Diameter of the sphere 2-2, length of the bars 0-2 to 0-25, breadth 0-005. Haiitat. — South Pacific, Station 291, surface. ' iSaposcena= Armour with tents ; (!X'/r,,uy.r,uvi. REPORT ON THE RADIOLAEIA. 1609 3. Sagoscena prfetormm, n. sp. (PI. 108, fig. 7). Tyi'^mitls subregular, of equal size and similar form, usually four-sided, crowned at the distal top with three or four divergent apical spines, which bear some irregular verticils of lateral and terminal branches. (Some five-sided and some six-sided pyramids are often intermingled with the four-sided.) Diincnsions. — Diameter of the sphere 2-6, length of the bars 0-3, breadth 0-006. Habitat. — Central Pacific, Stations 271 to 274, surface. 4. Sagoscena jyellonum, n. sp. (PI. 108, fig. 5). Pyramids subregular, of equal size and similar form, usually five-sided or six-sided, crowned at the distal end with three to six divergent apical spines, which bear an irregularly spinulate terminal knob. (The size and form of the apical spines is here very variable, as well as the number of the edges of the pyramids, which varies between three and six.) Dimensions. — -Diameter of the sphere 3-2, length of the bars 015 to 0-25, breadth O'OOS. Habitat. — Antarctic Ocean, Station 156, surface. 5. Sagoscena cruciarium, n. sp. Pyramids subregular, usually six-sided (intermingled with single five-sided and seven-sided or eight-sided forms), crowned at the distal top with three divergent, slender, apical spines, each of which bears three to six regular cruciate verticUs ; the four crossed lateral branches of each verticil bearing a spinulate terminal knob. (Similar to Sagoplcgma scenopJiora, PI. 108, fig. 13.) Dimensions. — Diameter of the shell 2-5, length of the bars 0-2 to 0-3, breadth 0-004. Habitat. — North Pacific, Stations 240 to 244, surface. 6. Sagoscena dehilis, n. sp. ' Pyramids more or less irregular, with four, five, or six sides, of somewhat different form and unequal size ; crowned at the top with one, two, or three slender apical spines, of variable length. These spines as well as the bars of the network bear scattered cruciate verticils, each usually composed of four crossed, small, lateral branches. Dimensions. — Diameter of the shell 2 to 3-0, length of the bars O'l to 0-15, breadth 0-003. Habitat. — Central Pacific, Stations 263 to 274, surface. 7. Sagoscena gracilis, Haeckel. Aulosphara fjracilis, R. Hertwig, 1879, Organism, d. Radiol., p. 91, Taf. ix. fig. i. Pyramids more or less irregular, with five, six, or seven sides, often of somewhat different form and unequal size ; crowned at the top with a single radial spine, which has the same size as the (ZOOL. CHALL. EXP. — PART XL. — 1886.) Rr 202 1610 THE VOYAGE OF H.M.S. CHALLENGER. bars of the network, and bears in its distal half four cruciate verticils, each composed of four crossed and curved horizontal branches. Dimensions. — Diameter of the sphere 1 to 2, length of the bars 0-08 to 0-09, breadth 0-002. ITabitat. — Mediterranean (Messina), surface. 8. Sagoscena fragilis, n. sp. Pyramids very irregular, with four to eight sides, of different form and unequal size ; crowned at the top with a single, slender, radial spine, of the same thickness as the slender bars of the net- work ; the latter as well as the former are smooth, without lateral branches. Dimensions. — Diameter of the sphere I'O to 2-0, length of the bars O'l to 0"2, breadth 0-001 to 0-002. Habitat. — Cosmopolitan ; Atlantic, Pacific, surface. Genus 678. Sagenoscena,^ n. gen. Definition. — S agosphserida with a delicate spherical shell, the thin wall of which is composed of a simple lattice-plate and covered with numerous pyramidal elevations ; each pyramid bears on its top one or more radial spines, and has an internal axial rod in its radial axis. The genus Sagenoscena differs from the preceding closely allied Sagoscena in tlie possession of an internal radial axial rod, which arises in the centre of the base of each pyramid, and is prolonged usually over its apex into a free, radial, apical spine. The distal end of the latter is usually armed with a bunch of terminal teeth or bristles. In the similar Sagoscena the internal cavity of the pyramids is simple, without axial rod. 1. Sagenoscena stellata, n. sp. (PL 108, fig. 3). Pyramids rather regular, usually six-sided (intermingled with single five-sided and four-sided forms) ; their axial rod and its prolongation, the radial apical spine, three to four times as thick as the slender edges of the pyramid. The distal end of the apical spine bears an elegant star of numerous radially divergent terminal branches, each of which is armed with a spinulate terminal knob. Dimensions. — Diameter of the sphere 3-5 to 4-0, length of the net bars 0-3, breadth 0'003 ; length of the radial spines 0-2, breadth 0-012. Halitat. — South Atlantic, Station 318, depth 2040 fathoms. 2. Sagenoscena ornata, n. sp. (PL 108, fig. 4). Pyramids rather regular, usually six-sided (intermingled with single five-sided and seven-sided forms); their axial rod and apical spine spindle-shaped, two to four times as thick as the smooth bars ' Sagenoscena='Net with tents ; aecyripn, axnuii. REPORT ON THE RADIOLARIA. 1611 of the network. The distal end of the radial spines bears an elegant, foliate, terminal knob, com- posed of four to six vertical pinnate leaves, lying in crossed meridional planes. IHmensimis. — Diameter of the sphere 2 to 3, length of the rods 01 to 0'2, breadth 0'003 to 0-01. Hah'itat. — Antarctic Ocean, Station 156, depth 1975 fathoms. 3. Sagenoscena penicillata, n. sp. (PI. 108, fig. 10). Pyramids rather regular, usually six-sided (intermingled with single five-sided, seven-sided, and eight-sided forms) ; their axial rod and apical spine spindle-shaped, thicker than the smooth bars of the network. The distal end of the radial spines is penicUlate and bears a brush of bristle- shaped, radial, terminal spinules (compare Sagosphccra iKnicilla,'^. 1607). Dimensions. — Diameter of the sphere 1 to 1'5, length of the bars 0"1 to 0'15, breadth 0'004 to 0-005. Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms. 4. Sagenoscena coronata, n. sp. Pyramids rather regular, usually four-sided (intermingled with single five-sided and six-sided forms) ; their axial rod and apical spines cylindrical, scarcely thicker than the smooth bars of the network. The distal end of the radial spines bears a corona of twenty to thirty curved terminal branches, which form a regiilar circle, and are armed with a spinulate terminal knob. Dimensions. — Diameter of the sphere 2 to 3, length of the bars 0'12 to 0'18, breadth 0'004 to 0-008. Habitat. — North Pacific, Station 256, surface. 5. Sagenoscena spathillata, n. sp. Pyramids more or less irregular, of different sizes and various forms, each composed of four to eight convergent rods and a central axial rod. The latter is prolonged into a free apical spine, which bears at the distal end a spathUla of eight to twelve recurved teeth, and often beyond it a second similar verticU. Dimensions. — Diameter of the sphere 4-0, length of the bars O'l to 0-2, breadth 0-002. Habitat. — ^Arctic Ocean, Greenland (Olrik). 6. Sagenoscena cruciata, n. sp. Pyramids very irregidar, of different sizes and various forms, each composed of six to nine convergent rods and a central axial rod. The latter is prolonged into a free apical spine, which bears three to five cruciate verticils, each composed of four perpendicularly crossed lateral branches which bear at the distal end a spinulate knob (similar to Sagviidium cnicicorne, PI. 108, fig. 9). Dimensions. — Diameter of the sphere 1-0 to 1-2, length of the bars 0-06 to 0-09, breadth 0-001. Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 1612 THE VOYAGE OF H.M.S. CHALLENGEE. Subfamily 2. Sagmarida, Haeckel. Definition. — Sago sph re rid a with a spongy spherical shell, the thickened wall of which is composed of a loose spongy framework. Genus 679. Sagmarium, n. gen. Definition. — S agosphasrida with a spongy spherical shell, the thickened wall of which is composed of a loose spongy framework, and exhibits a smooth surface, without radial spines and pyramidal elevations. The genus Sagmaritmi, and the following two genera of Sagosphaerida, represent together the subfamily Sagmarida, differing from the preceding Sagenida in the spongy structure of the shell-wall. Whilst in the latter the thin wall of the delicate spherical shell is composed of a simple lattice-plate with triangular meshes, in the former numerous liranches diverge from the nodal points of these meshes, and produce by union an irregular and loose spongy framework. The surface of this spongy hollow sphere (similar to Plegmot!j)ha3ra) is in Sagmarium smooth. 1. Sagmarium spongodicti/um, n. sp. (PI. 108, fig. 2). Spongy wall of the hollow sphere about half as thick as the radius of its cavity. Bars of the spongy framework veiy tliiu and fragile, smooth, without thorns. Dimensions. — Diameter of the sphere 2'0 to 24; length of the bars 01 to 0"2, breadth O'OOl. Hahitat. — South Atlantic, Station 333, surface. 2. Sagmarium plegmosphcerium, n. sp. (PL 108, fig. 14). Spongy wall of the hollow sphere about one-fourth as thick as the radius of its cavity. Bars of the spongy framework rather stout, studded with numerous small spines, which arise perpen- dicularly from their surface. Dimensions. — Diameter of the sphere 1'2 to 1'5, length of the bars 01 to 016, breadth 0'004. Hahitat. — Tropical Atlantic, Station 347, surface. 3. Sagmarium trigonizo7i, Haeckel. Didyosoma trigonizon, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 841. Spongodietyon trigonizon, Haeckel, 1862, Monogr. d. Eadiol., p. 459, Taf. xxvi. figs. 4, 5. Bars of the spongy framework thin, hregularly curved, bearing scattered small crosses, which are composed of four small rods arising perpendicularly from the bars. Nodal points of the frame- ' Sagmarium = Covering of a shield, armour ; aayfia^iou. REPORT ON THE RADIOLARIA. 1613 work partly pierced by a hole. The peculiar network of a complete specimen, observed by me at Portofiuo in 1880, was so similar to that of Spongodictyon trigonizon, described above (p. 91), and figured in 1862 in my ]\Ionograph, that 1 am doubtful if the two forms are not identical, the two medullary shells of the latter being accidentally entangled in the framework. (Compare p. 1602.) Dimensions. — Diameter of the sphere I'l to 1'5, length of the bars 01 to 0'2, breadth 0"002. Habitat. — Mediterranean (Messina, Portofino), surface. Genus 680. Sagmidium,^ n. gen. Definition. — S ago sphserida with a spongy spherical shell, the thickened wall of which is composed of a loose spongy framework, and bears on the nodal points of its surface radial spines. The genus Sagmidium differs from the preceding Sagmarium in the development of radial spines on the surface of the spongy hollow sphere. It bears therefore the same relation to the latter as SagosphcBra does to Sagena, and may be derived either from Sagmarium by the formation of radial spines, or from Sagosphcera by development of the spongy envelope. 1. Sagmidium unicorne, n. sp. Eadial spines simple, straight, smooth, a single one at each nodal point of the surface of the spongy sphere, bearing on its distal end a spinulate knob, or a bunch of numerous radial bristles. (Similar to Sagcnosccna pciiicillata, PI. 108, fig. 10.) Bars of the spongy framework smooth. Dimensions. — Diameter of the sphere 3"0 to 3'5, length of the bars O'lo to 0"2, breadth 0'003 to 0-006. Habitat. — Antarctic Ocean, Station 256, surface. 2. Sagmidium tricorne, n. sp. Eadial spines simple, smooth, usually three divergent united at each nodal point of the surface (sometimes two or four instead of three). Each spine bears on its distal end three short divergent conical teeth. (Similar to the terminal teeth of Sagosccna tentorium, PI. 108, fig. 6.) Bars of the spongy framework smooth. Dimensions. — Diameter of the sphere 1-6 to 2% length of the bars 0-06 to 0-09, breadth 0-001 to 0-002. Habitat. — Central Pacific, Stations 263 to 268, surface. 3. Sagmidiibm crucicome, n. sp. (PL 108, fig. 9). Puidial spines slender, verticillate, three or four divergent arising from each nodal point of the surface. Each spine bears three to six cruciate verticils of lateral branches ; each verticil bein" 1 Sagniidium = Bms\l armour, military cloak ; uayfifiiou. 1G14 THE VOYAGE OF H.M.S. CHALLENGER. composed of four crossed small branches with a spinulate terminal knob. Bars of the spongy framework partly covered with similar verticils. Dimensions. — Diameter of the sphere 2-0 to o'O, length of the bars 0-2 to 0-3, breadth 0-002 to 0003. Habitat. — North Pacific, Stations 240 to 244, surface. 4. Sagmidiiim quadiicorne, n. sp. (PL 108, fig. 12). Eadial spines stout, smooth, cylindrical, usually four divergent arising from each nodal point of the surface (sometimes three, five, or six, instead of four). Each spine bears on its distal end a club-shaped stellate knob. Bars of the spongy framework smooth. Dimensions. — Diameter of the sphere 4'5, length of the bars 0'2 to 0'3, breadth 0-003 to 0'005. Habitat. — South Pacific, Station 293, depth 2025 fathoms. 5. Sagmidium multicorne, n. sp. Eadial spines slender, more or less curved, verticillate, in variable number (three to six) divergent, arising from the nodal points of the surface. The spines as well as the bars of the spongy framework are partly simple, partly covered with irregularly scattered cruciate verticUs, very similar to those of Safjmarium trigonizon (or Dictyosoma trigonizon), figured in my Monograph, pi. xxvi. figs. 4, 5. DiTnensioTis. — Diameter of the sphere 5-0, length of the bars 0'2 to 0'3, breadth 0'003. Habitat. — Indian Ocean, Cocos Islands (Eabbe), surface. Genus 681. Sagoplegma,^ n. gen. Definition. — S agospliserida with a spongy spherical shell, the thickened wall of which is composed of a loose spongy framework, and bears on its surface numerous pyramidal elevations. The genus Sagoplcgnfia differs from Sagmarium, its ancestral form, in the development of pyramidal or tent-shaped elevations on the surface of the spongy hollow sphere. It exhibits, therefore, the same relation to the latter as the similar Sagoscena bears to Sagena. The wall of the spherical shell is in the two latter genera a thin simple lattice- plate, in the former a thickened spongy framework. 1. Sagoplegma pyramidophora, n. sp. Pyramids on the surface of the spongy sphere subregular, mostly tetrahedral, of nearly equal size and similar form. The three edges of each pyramid are prolonged over its top into three ' S<.ig(rplegma = Aimouv of framework ; aayn, ■n'hiyf/.oi,. REPORT ON THE RADIOLARIA. 1615 short, divergent, apical spines which aro forked at the distal end. (Very similar to Sagoscena castra and Sagoscena tentorium, I'l. 108, figs. 1, 6, probably derived from them, but differing in the spongy structure of the thickened sheU-wall, which is half as thick as the radius of its cavity.) Dimensions. — Diameter of the sphere 2-0 to 2'5, length of the bars 0'15 to 0-2, breadth 0'002. Habitat. — North Pacific, Stations 231 to 239, surface. 2. Sago2)legma scenophora (PI. 108, fig. 13). Pyramids on the surface of the spongy sphere irregular, with three to six sides, unequal in size and diSereut in form. The edges of each pyramid are prolonged over its top into three to six divergent apical spines, which bear three to six cruciate verticils, each composed of four small, crossed, lateral branches, armed with a spinidate knob at the distal end. Dimensions. — Diameter of the sphere S'O to 3'5, length of the bars 0'25 to 0'35, breadth 0'003. Habitat. — North Pacific, Stations 252, 253, surface. Family LXXVI. Aulosph^erida, Haeckel (Pis. 109-1 11). Aulosplimrida, Haeckel, 1862, Monogr. d. Radiol., p. 357. Definition. — Ph^odaeia witli a large spherical or subspherical (rarely spindle- shaped) articulated shell, which is composed of hollow tangential tubes. Nodal points of the loose network stellate, with a nodal cavity and astral septa. Meshes either triangular or polygonal. Hollow radial spines arise usually at the nodal points of the surface. No peculiar mouth in the shell. Central capsule tripylean, placed in the centre of the shell. The family Aulosphserida comprises a great number of splendid and widely distri- buted Ph^odaria, which have a special interest on account of the peculiarly complicated structure of their large lattice-shell, of the extraordinary beauty of their form and of their remarkable relations to the other Ph^odaria. They differ from all the other Eadiolaria in the peculiar articulate composition of the spherical skeleton of hollow tangential tubes, which are connected (and at the same time separated) by sutural or astral septa and filled up by jelly. The same peculiar structure recurs only in the closely allied Cannosphserida, which, however, differ in the possession of a second internal concentric shell, connected with the outer by radial beams. The similar Sagosphserida, which exhibit corresponding forms in various genera, differ from the Aulosphserida in the simpler structure of the delicate lattice-sphere, which is composed of very thin solid threads of silica, without astral septa. The Orosphserida, finally, also nearly related to the preceding families, differ from them in the coarse structure of the lattice-sphere, which is composed of very thick tangential, concentrically stratified rods, with an internal axial canal, but without astral septa at the nodal points. 1616 • THE VOYAGE OF H.M.S. CHALLENGER. One genus only, and two species, of Aulosphserida have been hitherto known, having been discovered by me in 1859 at Messina, and described in my Monograph in 1862 as AulosphcBra trigonopa and AulosphcBra elegantissima (loc. cit., p. 357, Taf. x. figs. 4, 5 ; Taf. xi. figs. 5, 6). The characteristic structure of their central capsule, as true Tripylea, was afterwards, in 1879, described more accurately by Richard Hertwig (Organism, d. Eadiol., p. 90, Taf. x. figs. 2, 8, 14). The rich collection of the Challenger has demonstrated that the i^ ulosphferida belong to the most common and most widely distributed Ph^odaria; many of them are distinguished by the admirable elegance and astonishing regularity of their large and delicate shell. Nine genera and fifty-six species of this great family are described in the following pages, which, however, may represent only a small part of the nimierous forms which are found on the surface as well as in difi"erent depths of all oceans and in all zones. The shell is in the great majority of Aulosphserida a regular sphere or an endospherical polyhedron. Two genera only, both rather rare, exhibit a different monaxonial form, one vertical main axis being developed either more or less than all the other ones of the sphere : — Aulatracttis is spindle-shaj)ed or elHpsoidal, with prolonged main axis ; AulojjJiacus is lenticular or discoidal, with shortened main axis. The former may be compared to the Prunoidea, the latter to the Discoidea, in opposition to the common regular Sph^eroidea. The size of the lattice-shell is very considerable in all Aulosphterida, its diameter varying usually between 1 and 3 mm., often it amounts to 4 or 5 mm. ; very rarely the diameter is more than 5 or less than 1 mm. The largest form observed is the spindle-shaped Aulatractus, in which the vertical prolonged main axis attains 6 to 10 mm., the horizontal equatorial axis 3 to 5 mm. The network of the lattice-shell exhibits in the Aulosphserida two different types, according to which we distinguish two different subfamilies : Aularida and Aulonida ; the former are much more common and richer in remarkable forms than the latter. The meshes of the network are in the Aularida constantly triangular, regular or subregular, and very similar to those of the Sagosphasrida ; at each nodal point six tangential tubes are usually united, so that the network may be regarded also as composed of regular hexagonal meshes, each of which is divided into six smaller triangular meshes (PI. 109, figs. 1, 3, 5). The second subfamily, the Aulonida, are much rarer than the former, and are distinguished by the polygonal meshes of the network ; these are usually more or less irregular, pentagonal and hexagonal intermingled, more rarely tetragonal, heptagonal, or octagonal ; usually three or four, rarely five or more tangential tubes are united at each nodal point (PI. Ill, figs. 1, 3). The size of the meshes is very considerable, and agrees with that of the Sagosphserida ; their diameter being usually between O'l and 0*3, rarely less or more. The hollow tubes which compose the loose network are usually cylindrical, straight or slightly curved, smooth (PI. Ill, fig. 2), more rarely somewhat spinulate (PL 109, EEPORT ON THE RADIOL AEI A. 1617 fig. 5). Thoir length is usuall}' between O'l ;ind 0"2 mm., rarely less than 0'08, or more than 0'24 mm.; their diameter usually between 0"003 to 0"005, sometimes only 0'002 or less, at other times 0"006 or more. In several species the tangential tubes are thinner in the middle part, and thickened towards the two ends (PI. 109, figs. 3, 4). Each tube con- sists of a thin cylindrical wall of silex, and of a jelly-mass filling up its cavity ; in its axis runs a very thin, straight or slightly curved thread of silica, the axial filament. The arrangement of the tangential tubes, which originally, in the simplest Aulosphtei'ida, lie tangentially in the spherical face of a simple lattice-sphere, exhibits various secondary modifications, leading to various interesting generic forms. Two genera only, Aulana (with triangular meshes, PI. Ill, fig. 2) and Aulonia (with polygonal meshes, PL 111, fig. 1) possess a smooth, perfectly simple lattice-sphere, and may therefore be regarded as the ancestral genera of the two subfamilies. Two other corresponding genera, the common Aidosphcera (PI. 109) and the rarer Aulastrum (PL 111, fig. 3), diS"er from the former in the development of radial spines at the nodal points of the simple lattice-sphere. Aulojjhacus may be developed from Aulosjihmra by shortening, Aulatractus, however, by prolongation of the vertical main axis (PL 111, figs. G, 7). In two genera, Auloplegma and Aulodictyum, the latticed wall of the spherical shell becomes thickened and spongy, an irregular framework being formed by tubes connected in diflerent directions (PL 111, fig. 8). The most remarkable and the most elegant form, however, of the whole family is represented by Auloscena (PL 110). The entire surface of the spherical lattice-shell is here covered with numerous regular or subregular pyramids, or tent-shaped elevations. Usually each pyramid, is six-sided, and surrounded by six other six-sided pyramids, their bases being separated by six triangular meshes, which lie in the spherical face. A similar elegant form is developed among the Sagospha?rida in the genera Sagoscena, Sagenoscena and Sagoplegnv.i (PL 108, fig. 1). The structure of Auloscena, however, is usually more regular, and in the top of each pyramid a radial tube arises. The junction of the cylindrical tubes at the nodal points of the network is very remarkable. Aulana, the simplest form of the family, exhibits at each nodal point the union of six tangential tubes (PL 111, fig. 2) ; their ends are so pointed and truncated that they are connected in the form of a regular six-radiate star ; the conical end of each tube is separated from, and at the same time closely connected with, the adjacent conical ends of the two neighbouring tubes by a thin septum, the astral or sutural septum. The six astral septa compose together a six-radiate star, and in the centre of this star the six axial filaments of the tubes are united. Their central union is surrounded by a small, double-contoured circle, and this circle seems to be the perimeter of a small and flat (^avity on the in.side of the star, which we call shortly the "nodal cavity" ("die kleine Vertiefung" according to Hertwig, he. cit., p. 90). The nodal cavity of Aulana probably possesses a central opening on its inside and six small surrounding pores, which (ZOOL. CHALL. EXP. — PART XL. — 1886.) Rr 203 1618 THE VOYAGE OF H.M.S. CHALLENGER. lead into the six conuected tangential tubes. In AulosphcBra and Auloscena, where a radial spine arises at each nodal point, its axial filament arises from the centre of the star, and is usually prolonged on the inside into a free centripetal beam (PI. 109, figs. 6, 7; PI. 110, figs. 4, 6). This centripetal beam is a slender, very thin, conical tube (often with a six-sided pyramidal base) and perhaps of great morphological interest as a rudiment, being homologous to the hollow radial beams which connect the two concentric spheres of the Cannosphserida. Possibly the Aulosphserida have been derived from the latter by loss of the inner shell and reduction of the radial beams ; the centripetal beams which are found in many (but not in aU) Aulosphajrida, may lie the last remnant of those radial beams. They contain also an axial filament, as a direct internal prolongation of that of the external radial spine. The axial filaments of the radial spines are usually connected ■\\-ith their thin wall by a variable number of scattered transverse threads, or sometimes even by thin transverse sej^ta (PI. 110, figs. 4-7, &c.). This structure corresponds to the similar axial filaments and their thin filiform transverse branches which we have found in other Ph^odaeia, e.g., in the Tuscarorida and Circoporida. The Aulouida (with polygonal meshes) exhibit in general the same structure as the Aularida (with triangular meshes). But whilst in the latter usually six tangential tubes are united at each nodal point, in the former only three or four tubes become united. Therefore also the number of the small sutui'al partitions or astral septa, which radiate from the central openings of the nodal cavity, is six in the latter, three or four in the former. Correspondingly three or four small pores lead from the nodal cavity into the surrounding tangential tubes. The true nature of the nodal points, and the intimate structure of the difi"erent parts here united, is a matter which it is very difticult to explain. It is a certain fact, well established by hundreds of observations, that in the complete and well-preserved skeletons which are perfectly purified by fire, or by hot mineral acids, and afterwards dried, ail the tubes of the skeleton, the tangential as well as the radial cylinders, become fiUed up by air. Each tube contains usually one large cylindrical air-bubble, with two hemispherical ends. But the air-bubbles of the neighbouring tubes are completely separated one from another by the thin astral or sutural septa, and the air-bubble of the radial tubes is also separated from the former. The central cavity of each nodal point is therefore surrounded in the Aularida by six, in the Aulonida by three or four separate cylinders of air. This fact seems to be explained only on the supposition that each single tube has two terminal pores or fissures, which open into the two nodal cavities on its two ends. The radial tubes must also possess at least one small opening, probably on their base, and probably they have another on their distal apex. In no other way can it be explained, that in aU complete, well-preserved and purified skeletons, each single tube constantly becomes easily filled by an air-bubble after drying. In the living Aulosphserida the cavities of all tubes are filled up by a jelly-substance, REPORT ON THE RADIOLARIA. 1619 wliich may Ije .stained by carmine and is probably identical with the jelly of the calymma. The latter is probably in direct connection with the former by the central pore of the nodal cavity, which is placed on its inside and surrounded by the astral septa ; these separate the tangential tubes, radiating from one nodal point, completely, and are thin and simple, but very solid lamellae of silica. Therefore the nodal stars of broken shells usually remain united, whilst the single radiating tubes composing them are broken oft' (PI. 110, figs. 3, 8, 10). But it happens only rarely (and only in certain individual species) that complete single tubes separate; usually the fragments of the connected neighbouring tuljcs remain on their ends. The two small terminal openings of each tangential tube, which lead from its cavity into the nodal cavity, and are surrounded on each end by the truncated ends of two neighbouring astral septa, are very difficult to observe (PI. 110, figs. 8-10). The wonderful elegance and the high complication of these regular skeletons of the Aulosphserida, produced by a single cell, becomes increased by the graceful and manifold appendages and apophyses which are usually developed on the radial tubes. In only a few species these are simple, as in the common and cosmopolitan AulosphcBra trigonopa. Usually lateral or terminal appendages are develojjed in great variety, a selection of which is figured in Pis. 109-111. The lateral branches are either irregularly scattered spines (PI. 110, figs. 3-7) or regular verticils of cruciate or radiate spines ; each verticil is usually composed of four perpendicularly crossed horizontal branches (PI. 109, figs. 3, 4, 7, 10, &c.), more rarely of a greater number of radiating transverse branches. The terminal appendages of the radial spines exhibit a striking similarity with those of the Aulacauthida (Pis. 102-105). They are either forks with two or three divergent branches (PL 111, figs. 3, 4), or regular crosses with four branches opposite in paii"s (Pi. 109, figs. 2, 6, 7, 10), or elegant crowns or verticils, composed of numerous radiating branches (PI. 110, figs. 1-6). The distal ends of the terminal as well as of the lateral branches are either simple, pointed, or armed with a spinulate knob, or with a terminal spathilla. The variety and elegance of these terminal ornaments, the function of which is that of capturing tentacles, is in the Aulosphserida not less admirable than in the Aulacauthida and Coelodendrida. The central ccqjsule of the Aulosphgerida (PI. Ill, fig. 2) was first figured in my Mouocraph (1862, Taf. xi. fig. 5) of Aulosphcera elegantissima, as a sphere of 0'2 to 0'3 mm. in diameter. I described there the large nucleus (of half that size) as a spherical " Binuenblase," and the numerous pseudopodia which arise from the capsule and radiate through the meshes of the lattice-shell. But I had not observed at that time the three typical openings of the capsule, which were first discovered and accurately described by R. Hertwig (1879, loc. cit., p. 94, Taf. x. figs. 2, 4, 5, 8, 14). The large astropyle with its radiate operculum and proboscis, and the two smaller lateral parapylas, provided with 1620 THE VOYAGE OF H.M.S. CHALLENGER. a smaller tubule, have in general the same shape as in the closely allied Sagosphserida and Orosphgerida, and agree in their strong development with that of the Aulacanthida. The collection of the Challenger contains numerous well-preserved preparations of Aulosphserida, which were stained by carmine immediately after being captured, and in which the central capsule and its nucleus exliibit the same intimate structure already accurately described by E. Hertwig. The diameter of the capsule is usually between 0"2 and 0'3, rarely less than 0"15 or more than 0'35 mm., the nucleus has half that size. The phaeodium has usually about the same volume (PI. 109, fig. 1), l)ut seems to be in many Aulosphairida less developed than in the other Ph^odaeia. Synojysis of the Genera of Aulosphcerida. 1. Subfamily Aularida. Meshes of the net- work triangular. Tegular or sub- regular. Six tangential tubes united at each nodal point of the net. IL Subfamily AulouiJa. Meshes of the net- work polj'gonal, usually irregular. Three or four (rarely more) tan- gential tubes united at each nodal point. Shell spherical, with a simple network. Shell spherical, with pyra- midal elevations or with \ spongy framework. f "Without radial tubes, With radial tubes in the nodes of the net, Shell covered with pyramidal elevations, the top of which bears a radial tube, Shell with spongy framework, the surface of wliich bears radial tubes, .... C Shell lenticular, with shortened c,, ,, , 1-1 -,1 main axis and radial tubes, Shell not spherical, either lenticular orspindle-shaped,<| g^^jj spindle-shaped, with pro- longed main axis and radial tubes, .... with simple network. Shell spherical, with a simple network. ' "Without radial tubes, "With radial tubes in the nodes of the net, Shell spherical, with a spongy ) ^^r-^^^^^^ ,,ji,i ^^^^ framework. ) ' 682. Aularia. 683. Aulospluira. 684. Auloscena. 685. Auloplegma. 686. AnJophacus. G87. Aulatradus. 688. Aulonia. 689. Aulastrum. 690. Aulodidyum. Subfamily 1. Aulapjda, Haeckel. Definition. — Network of the shell with triangular, regular or subregular meshes ; six tangential tubes being united at each nodal point. REPORT ON THE RADIOLARIA. 1621 Genus 682. Aularia,^ n. gen. Definition. — A u 1 o s p li -m r i d a with triangular meshes in the network, the tangential tubes of which form a simple smooth lattice-sphere. No radial tubes at the nodal points. The genus Aularia is the simplest form of the subfamily ^Vularida, or of those Aulosphasrida in which the network of the shell is composed of regular or subregular triangular meshes ; they are the main group of the family, much more common and far richer in distinct forms than the Aulonida (or the Aulosphserida with polygonal meshes). The shell of Aularia, the probable ancestral form of the family, is a simple lattice-sphere with smooth surface, and diflFers from the common Aulosphcera in the absence of radial tubes, arising at the nodal points. 1. Aularia ternaria, n. sp. (PI. Ill, fig. 2). Tangential tubes of the network cylindrical, straight, smooth, of equal breadth. Triangular meshes of the reticular sphere very regular, equilateral triangular. This species is the simplest of all Aulosphserida and similar to the common Aulosphcera trif/onojja, but has no radial tubes. Bimemions. — Diameter of the sphere I'O to 2-0 ; tubes 01 to 015 long, 0-007 to O'Ol broad. Habitat. — Central Pacific, Stations 270 to 274, surface. 2. Aularia tuhularia, n. sp. Tangential tubes of the network cylindrical, straight, of equal breadth, thorny, covered with numerous short bristle-shaped thorns, which are all of the same length and perpendicular to the tube. Dimensions. — Diameter of the sphere 30 ; tubes 015 long, 0'005 broad. Habitat. — South Pacific, Station 291, depth 2250 fathoms. 3. Aularia trigonaria, n. sp. Tangential tubes of the network smooth, very thin in the middle part, gradually dilated towards both ends, so that the nodal points of the network are inflated. (Similar to Aulospha:ra sceptrophora, PI. 109, fig. 3, but without radial tubes.) Dimcjisions. — Diameter of the sphere 2-2; tubes 01 long, 0-002 broad in the middle part, Q-Ol on both sides. Habitat. — North Pacific, Station 253, depth 3125 fathoms. ' .4 uZan'a = Tubular shell ; xi/hi^ia. 1622 THE VOYAGE OF H.M.S. CHALLENGER. Genus 683. Aulosphcera,^ Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 802. Definition. — A ulospliserida with triangular meshes in the network, the tangential tubes of which form a simple lattice-sphere. Radial tubes arise at its nodal points. The genus Aulosjihcera, the first observed form of all Aulosphserida, is also the most common form of the whole family, the richest in distinct species, and widely distributed over all oceans, in the tropical as well as in the temperate and Arctic zones. The twenty-one species here enumerated may be only a small part of the numerous forms, which may be distinguished according to the different forms of the tubes. One of the two Mediterranean species, which I first described in my Monograph, is cos- mopolitan. The shell is in all species a simple regular lattice-sphere with triangular meshes ; it difiers from the preceding Aularia in the development of radial tubes at the nodal points of the lattice-work. Subgenus 1. Aulosphcerantha, Haeckel. Definition. — Radial tubes simple, smooth, without terminal teeth and without lateral branches. 1. Aulosphcera trigonopa, Haeckel. Aulosphoera trigonopa, Haeckel, 1862, Monogr. d. Radiol. , p. 359, Taf. x. fig. 4. Radial tubes of the spherical shell cylindro-conical, straight, smooth, of the same length as the tangential tubes of the uetwork, which are also smooth, straight, cylindrical. Dimensions. — Diameter of the sphere I'O to 2'0 ; tangential tubes O'l to 0'2 long, 0'002 to 0-004 broad. Habitat. — Cosmopohtan ; Mediterranean, Atlantic, Indian, Pacific, surface. 2. Aulosphcera fiexuosa, n. sp. Eadial tubes slenderly conical, smooth, gradually tapering towards the distal end, more or less irregularly curved, two to three times as long as the tangential tubes, which are cylindrical, straight and smooth. Dimensions. — Diameter of the sphere 2-2 ; tangential tubes 015 long, 0-006 broad. Habitat. — North Atlantic, Fteroe Channel (Gulf Stream), John Murray, surface. ■ ^i4os/)/ifEra = Tubular sphere ; aixo';, acfccha. REPORT ON THE RADIOLARIA. 1623 Subgenus 2. AulosphcereUa, Haeckel. Dejinition. — Radial tubes smooth, without lateral branches or spines, but armed with a verticil of teeth at the distal end. 3. Aulosphcera dlodon, n. sp. Eadial tubes cylindro-couical, straight, smooth, of the same length as the smooth, cyhndrical, tangential tubes ; armed at the distal end with two divergent terminal teeth, which are sUghtly curved, pincer-shaped, and about one-fourth as long as the tube. Dimensio7is. — Diameter of the sphere 2 '5 ; tangential tubes OIG long, O^OOS broad. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. 4. AidosphcBra triodon, n. sp. (PL 109, fig. 8). Eadial tubes cylindrical, straight, smooth, two to three times as long as the smooth, cylindrical, tangential tubes ; armed at the chstal end with three divergent terminal teeth, which are straight or slightly curved and about one-third as long as the tube. Dimensions. — Diameter of the sphere 1"2 ; tangential tubes O'l long, O'Ol broad. Habitat. — North-Eastern Pacific (off Japan), Station 231, surface. 5. Aidos2:>h(era tetrodon, n. sp. Eadial tubes slender, cylindrical, straight, smooth, about three times as long as the smooth, cylindrical, tangential tubes ; armed at the distal end with a regular cross of four terminal teeth, which are directed almost horizontally, and are shghtly recurved (just as in Aulosphcera spathillata, PI. 109, fig. 7, but longer and without lateral verticils). Dimensions. — Diameter of the sphere 1'6 ; tangential tubes 015 long, 0'005 broad. Eahitat. — South Pacific, Station 289, depth 2550 fathoms. 6. AidosphcBra polyodon, n. sp. Eadial tubes slender, spindle-shaped, gradually tapering towards the two ends, smooth, about twice as long as the cyhndrical, smooth, tangential tubes ; armed at the distal end with a verticil of twelve to twenty or more divergent, conical, shghtly curved teeth. Dimensions. — Diameter of the sphere 3"3 ; tangential tubes 0'2 long, O'Ol broad. Habitat. — Central Pacific, Station 272, depth 2600 fathoms. , Subgenus 3. AulosphcBrissa, Haeckel. Definition. — Radial tubes verticillate, armed with a variable number of regular verticils of lateral branches. 1624 THE VOYAGE OF H.M.S. CHALLENGER. 7. Aulosphcera verticillata, n. sp. Eadial tubes slender, cyliudro-conical, straight, tapering towards the distal end, about as long as the smooth, cylindrical, tangential tubes ; armed with eight to twelve verticils of three curved, simple, lateral branches. (Very similar to the tubes of Aulastrum trichoceros, PI. Ill, fig. 5«.) Dimensions. — Diameter of the sphere 1-6 ; tangential tubes 0-15 long, O'OOS broad. Habitat. — South Tacific, Station 300, surface. 8. Aulosphcera spathillata, n. sp. (PI. 109, figs. 7, 7a). Eadial tubes slender, cylindro-conical, straight, tapering towards the distal end, two to three times as long as the smooth, cylindrical, tangential tubes ; armed with two or three distal alternate verticils, each of which forms a horizontal cross of four (sometimes three or five) equidistant branches ; their distal ends are on the terminal cross simple hooks, on the proximal cross spathillte. Dimensions. — Diameter of the .sphere 3'2 ; tangential tubes 0"12 to 016 long, O'Ol broad. Hahitat. — South-Eastern Pacific (off Valparaiso), Station 298, depth 2225 fathoms. 9. AulosphcBra cruciata, Haeckel (PL 109, fig. 10). Aulosphcera elegantissima, E. Hertwig {iion Haeckel), 1879, Organism, d. Eadiol., p. 90, Taf. ix. fig. 1; Taf. X. figs. 2, 4, 5, 8, U, 15. 1 Aidosphoira xiourtalesii, Duncan, 1881, Journ. Eoy. Micr. Soc, p. 175, pi. iii. figs. 1-3. Eadial tubes slender, cylindro-conical, straight, tapering towards the distal end, twice as long as the smooth, cylindrical, tangential tubes ; armed with four to eight cruciate equidistant verticils, each of which forms a regular cross of four equal, horizontal, lateral branches, bearing at the end a .small knob or spathilla. Dimensions.— T>'mm.QteTi of the sphere V2 to 1'8 ; tangential tubes O'l to 0"15 long, O'OOS broad. Hahitat. — Mediterranean (Messina), North Atlantic (Canary Islands), Caribbean Sea. 10. Aulosphcera elegantissima, Haeckel. Aulospluei-a elegantissima , Haeckel, 1862, Monogr. d. Eadiol., p. 359, Taf. x. fig. 5; Taf. xi. figs, 5, 6. Eadial tubes cylindrical, straight, twice as long as the smooth, cylindrical, tangential tubes ; armed with four to eight equidistant verticils, each of which is composed of eight to twelve simple, horizontal, lateral branches. Dimensions. — Diameter of the sphere 1'5 to 2 ; tangential tubes 012 to OIG long, 0-00-4 broad. Hahitat. — Mediterranean (Messina), surface. 11. Aulosphcera histernaria, n. sp. (PI. 109, figs. 11, 12). Piadial tubes cylindrical, straight, about as long as the cylindrical tangential tubes, smooth or somewhat thorny, armed at the distal end with two alternate verticils of three branches, which bear REPORT ON THE RADIOLARIA. 1625 a terminal spathilla ; the proximal branches are twice as long as the distal, and alternate with tliem regularly, so that the six branches lie in six different meridional planes. Dimensions. — Diameter of the sphere 2'5 ; tangential tubes 02 long, 001 broad. Hahiiat. — Antarctic Ocean, Station 156, surface. 12. Aulosphcsra dendroj^hora, u. sp. (PI. 109, fig.s. 1, 2). Radial tubes cylindrical, straight, about as long as the cylindrical, smooth, tangential tubes, armed in the distal half with three verticils of four crossed branches ; the four proximal branches are three times as long as the four distal, and twice as long as tlie four intermediate branches. All twelve branches bear a terminal spinulate knob, and lie in two perpendicularly crossed meridian planes. Dimensions. — Diameter of the sphere 2'2 to 2'S ; tangential tubes 0'2 long, O'Ol broad. Hahitat. — Central Pacific, Station 271, depth 2-42o fathoms. 13. Aulusphcera sceptrophora, u. sp. (PL 109, figs. 3, 4). Radial tubes straight, in the proximal half conical, with inflated base ; in the distal half cylindrical, with five or six cruciate verticils, each of which has four perpendicularly crossed teeth. Tangential tubes half as long as the radial tubes, in the middle part very thin, thickened towards both ends. Dimensions. — Diameter of the sphere 1^2 ; tangential tubes O'l long, 0'002 broad in the middle part, 0"012 on both ends. Hahitat. — Central Pacific, Station 266, depth 2750 fathoms. 14. AulosphcBra spatliop)honi, n. sp. Radial tubes slender, cylindrical, more or less curved, about three times as long as the tangential tubes, in the distal half with eight to twelve verticils of six to eight lateral branches, which are forked, decrease in length towards the distal end, and bear on each ramule a terminal spathilla. Tangential tubes slightly curved and thorny. (Similar to Aulopleijma pcrpkxum, PI. Ill, fig. S«, but with a simple lattice-sphere.) Dimensions. — Diameter of the sphere 2'2 ; tangential tubes 0'2 long, 0"006 broad. Ealitat. — North Pacific, Station 244, depth 2900 fathoms. Subgenus 4. AulosphcBr omnia, Haeckel. Definition. — Radial tubes spiuy or tlioruy, with irregular lateral branches, often with forked distal ends. (ZOOL. CHALL. EXP. PART. XL. — 1886.) Rr 204 162tj THE VOYAGE OF H.M.S. CHALLENGER. 15. AulosphcBva bifiirca, n. sp. Kadial tubes cylindrical, straight, thorny, twice as long as the smooth, cylindrical, tangential tubes, forked at the distal end, with two curved, convergent, thorny, terminal branches. (Similar to Aulastrum dendroceros, PI. Ill, figs. 4«-4c, but with longer and more spinulate branches.) Dimensions. — Diameter of the sphere 3-2 ; tangential tubes 0-25 long, 0-01 broad. HaUtat. — North Pacific, Station 239, surface. 16. AulosiohcBva trifurca, u. sp. (PL 109, fig. 9). ' Eadial tubes cylindrical, straight, thorny, about as long as the smooth, cylindrical, tangential tubes, forked at the distal end, with three curved, convergent, terminal branches. Dimensions. — Diameter of the sphere 2-5 to 3-0; tangential tubes 0-2 long, O'Ol broad. Habitat. — North Pacific, Station 2-iO, surface. 17. Aulosphwra quadrifurca, n. sp. Eadial tubes cylindro-conical, straight, about as long as the smooth, cylindrical, tangential tubes ; studded with numerous irregular lateral branches in the distal half, and armed at the distal end with a cross of four divergent, forked, terminal branches. Dimensions. — Diameter of the sphere 4-2 ; tangential tubes 0-2 long, 0-01 broad. Habitat. — Indian Ocean, Madagascar (Eabbe), surface. 18. Aulosphcera multifurca, n. sp. Eadial tubes cylindrical, more or less curved, three to four times as long as the smooth, often curved, tangential tubes ; studded with numerous forked, irregular, lateral branches, and armed at the distal end with a verticil of twelve to sixteen divergent, forked, terminal branches. Dimensions. — Diameter of the sphere 1-2 ; tangential tubes 0-06 long, 0-003 broad. Habitat. — Arctic Ocean, Greenland (Olrik), surface. 19. Aulosphcera coronata, n. sp. Eadial tubes spindle-shaped, tapering from the thicker middle part towards both ends, twice as long as the thorny tangential tubes, studded with numerous irregular, curved, lateral spines, and bearing at the distal end a corona of twenty to twenty-five divergent, curved, terminal branches. (Similar to AuloseevM flammabunda, PL 110, fig. 4.) Dimensions. — Diameter of the sphere 3'0 ; tangential tubes 0-2 long, 0"08 broad. Hahitat. — Tropical Atlantic, Station 347, surface. i REPORT ON THE RADIOLARIA. 1627 20. Aulos2iluvra undulata, ii. sp. (PL 109, fig. G). Radial tubes slender, cylindro-conical, undulate, about twice as long as the spinulate and imdulate tangential tubes ; studded with numerous short, perpendicular, lateral branches which are partly simple, partly forked, and bear small terminal spathillte. The distal end of each radial tube bears usually a verticil of four to eight similar pediculate spathilltc. Bimcnsmis. — Diameter of the sphere 24 ; tangential tubes 0'2 long, O'OOo broad. Eabitat. — North Pacific, Station 252, surface. 21. Aulospliceni spinosa, u. sp. (PI. 109, fig. 5). Radial tubes and tangential tubes equal in size and similar in form, more or less curved, slender, cylindrical, densely studded with numerous irregular spines. Ditnenskms. — Diameter of the sphere 16 ; tangential tulies O'l long, 0'004 broad. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. Genus 684. Auloscena,^ n. gen. Definition. — A ulosphserida with triangular meshes in the network, the tangential tuljes of which arise in pyramidal groups of six over the surface of the sj^herical shell. Radial tubes arise at the tops of the six-sided pyramids, which cover the whole surface. The genus Auloscena differs from the preceding AidosphcBra, its ancestral form, in a very remarkable and elegant character. The tangential tubes of the network here lie not on a spherical face (as in the latter), but arise over the surface of the spherical calymma in the form of numerous, regular, hexagonal pyramids ; each j)yramid being com- posed of six convergent ascending tubes, which are united in a common nodal point; at the latter arises a radial tube, which usually bears an elegant corona of radially divergent terminal branches. Therefore the base of each hexagonal pyramid is in contact at its six corners with the basal corners of six similar neighbouring pyramids, whilst the neighbouring sides of the bases are separated by six regular triangular meshes, which lie on the spherical face. In some species this remarkable and elegant structure is quite regitlar, whilst in others it becomes more or less irregular. Subgenus 1. Auloscenium, Haeckel. Definition. — Radial tubes smooth, without lateral branches or spines, bearing a terminal verticil at the distal end. 1 Auhicaw, = Tubular tent ; xix6;, cx.ni>fi. 1628 THE VOYAGE OF H.M.S. CHALLENGER. 1. Auloscena mirabilis, n. sp. (PI. 110, figs. 1, 2). Eadial tubes cylindrical, straight, smooth, about as long as the smooth i^yramidal tubes (or the convergent tubes which form the edges of the six-sided pyramids of the network). The distal end of each radial tube bears an elegant sjDathillate terminal corona (fig. 2), or a verticil of fifteen to twenty curved radial branches, the distal end of which is armed with a spinulate knob. Dimensions. — Diameter of the sphere 2'0 to 3-0; pyramidal tubes 0-16 to 0-24 long, 0-008 broad. Habitat. — Central Pacific, Stations 271 to 274, depth 2350 to 2750 fathoms. 2. Auloscena sjiectahilis, u. sp. (PL 110, figs. 8, 9). Eadial tubes cylindro-conical, straight, smooth, twice as long as the smooth pyramidal tubes, armed at the distal end with a conical terminal corona, or a verticil of twelve to sixteen divergent, straight, pointed, terminal branches. Dimensions.- — Diameter of the sphere 4'0 to 5'0 ; pyramidal tubes 0'25 to 0'3 long, 0'012 broad. Habitat. — Antarctic Ocean, Station 154, surface. 3. Auloscena ijyramidalis, n. sp. Eadial tubes slender, conical, straight, smooth, of the same length as the smooth pyramidal tubes, armed at the distal end with a hexagonal terminal corona, or a verticil of six divergent, straight, pointed, terminal branches, which correspond to the six sides of a pyramid ; the proximal apex of this terminal pyramid is opposed to the distal apex of the similar basal pyramid. Dimensions. — Diameter of the sphere 3'0 to 4-0 ; pyramidal tubes 0'2 to 0'3 long, O'Ol broad. Habitat. — Tropical Atlantic, Stations 347 to 349, surface. Subgenus 2. Auloscenidium, Haeckel. Definition. — Eadial tubes thorny, with kiteral branches or spines, usually with a terminal verticil at the distal end. 4. Auloscena tentorium, n. sp. (PI. 110, fig. G). Eadial tubes spindle-shaped, tapering towards both ends, nearly smooth, of the same length as the smooth pyramidal tubes. The distal part of the radial tubes is thorny, and bears a verticil or a corona of twenty to thirty slender terminal branches, which are about one-third as long as the tube, sabre-shaped, with concave outer edge and pointed distal end. Dimensions. — Diameter of the sphere 4-0; radial tubes 0-3 to 0-4 long, 002 to 0-03 broad. Habitat. — North-Western Pacific (oft" Japan), Station 231, surface. REPORT ON THE RADIOLARIA. 1620 5. Auloscena verticillus, n. sp. (PL 110, iigs. 10, 11). Radial tubes slender, cylindrical, twice as long as the smooth or somewhat thorny pyramidal tubes, armed in the distal part with two or three irregular verticils of three to six perpendicular spines, and on the distal end with a corona of twelve to eighteen straight, divergent, pointed, terminal branches, whieli often arise in pairs. Dhnctisions. — Diameter of the sphere 3"2 ; pyramidal tubes 0"15 long, 001 broad. Habitat. — South Atlantic, Station 318, depth 2040 fathoms. 6. Auloscena penicillus, n. sp. (PI. 110, fig. 3). Eadial tubes slender, cj'lindrical, thorny, one and a half times as long as the thin and smooth pyramidal tubes, armed in the distal half with densely crowded perpendicular spines and a terminal corona of numerous (twenty to thirty or more) bristle-shaped branches, lOie a brush. Dimensions. — Diameter of the sphere 20 to 2'5 ; radial tubes 015 to 02 long, 0'005 to 001 broad. Habitat. — Antarctic Ocean, Stations 156, 157, surface. 7. Auloscena flammabicnda, u. sp. (PI. 110, fig. 4). Piadial tubes cylindro-conical, twice as long as the thorny pyramidal tubes, studded with numerous curved spines, and armed with a verticil or corona of numerous (twenty to thirty or more) undulate, divergent, pointed, terminal branches. Dimensions. — Diameter of the sphere S'O ; radial tubes Oo to 0'4 long, 002 to 0'03 broad. Habitat. — North Pacific, Station 252, surface. 8. Auloscena gigantea, n. sp. (PI. 110, fig. 7). Piadial tubes cylindrical, thorny, about as long as the thorny pyramidal tubes, armed in the distal half with four to eight verticils of short curved ciliie, and at the distal end with a similar small terminal verticil. Dimensions. — Diameter of the sphere 5'2 ; pyramidal tubes 0'2 to O'S long, O'Ol broad. Habitat. — Central Pacific, Stations 265 to 268, surface. 9. Auloscena arboretum, n. .sp. Eadial tubes cylindrical, straight or slightly curved, about the same length as the smooth pyramidal tubes ; armed in the distal half with three or four verticils, tapering in size towards the distal end; each verticil is composed of four crossed and curved branches, which bear a terminal spinulate knob. (This species is very similar to Aulospliara dendrophora, PL 109, fig. 1, and may 1630 THE VOYAGE OF H.M.S. CHALLENGER. be derived from it by elevation of the liexagonal pyramids, which in the latter lie in the spherical plane). Dimensiom. — Diameter of the sphere 44 ; pyramidal tubes 025 long, 0-01 broad. Habitat. — Indian Ocean, Cocos Islands (Eabbe), surface. 10. Auloscena serrata, n. sp. (PI. 110, fig. 5). Eadial tubes spindle-shaped, tapering towards both ends, thorny, twice as long as the thorny pyramidal tubes ; armed at the distal end with an elegant corona which is composed of twelve to sixteen curved terminal branches. Each branch bears two opposite series of small recurved teeth and a terminal spathilla of six to eight larger recurved teeth. DimeTisions. — Diameter of the sphere 3-0; pyramidal tubes O'S long, 0012 broad. Habitat. — South Pacific, Station 298, depth 2225 fathoms. Genus 685. Atdoplegma,'^ Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. 6. Definition. — A u 1 o s p h as r i d a with triangular meshes in the network, the tubes of which are connected in different directions, and form the spongy wall of a spherical shell. Radial tubes arise on the surface at the nodal points. The genus Atdoj^legma, one of the rarest forms of AulospliEerida, differs from the preceding genera in the spongy structure of the lattice-sphere, the thickened wall of which is composed of a loose framework. Numerous tubes, irregularly disposed in different directions, are connected at the nodal points of this loose spongy framework, whilst radial tubes arise on the surface of the latter. Auloplegma exhibits therefore a relation to Anlosphwra, its probable ancestral form, similar to that which PlegmosphcBoxt does to Acanthosphcera among the Sphseroidea. 1. Auloplegma perplexum, n. sp. (PI. Ill, figs. 8, 8a). Eadial tubes straight, cylindro-conical, armed with six to eight verticils of lateral branches, which increase in size towards the base ; each verticil is a cross of four dichotomous delicate ramules, ending with a spinulate knob. The length of the radial tubes is about equal to the radial diameter of the spongy framework, which forms the thick wall of the spherical shell, and is composed of smooth and straight cylindrical tubes. Dimensions. — Diameter of the shell 1-5 to 2-0, of its wall 0-3 to 04 ; length of the radial tubes 0-2 to 0-3, basal breadth 0015. Habitat. — North Pacific, Station 237, surface. 1 Aul(ypUrjma = 'S\xhvi\&T framework ; aiXoV, wAiy^*. REPORT ON THE RADIOLARIA. 1031 2. Auloplegma spongiosum, n. sp. (IM. Ill, fig. 9). Kadial tubes slender, straight, cylindro-couical, studded irregularly with lateral branches, which are short, simple, sliglitly curved, partly vertieillate in the distal third, and ending with a small spinulate knob. The length of the radial tubes is about twice as great as the radial diameter of the spongy framework, which forms the wall of the spherical shell, and is composed of thorny or verti- eillate cylindrical tubes. Dimcnsio7is. — Diameter of the shell 3'2, of its wall 01 ; length of the radial tubes 0'24, breadth 001. Rahitat. — North Pacific, Station 231, surface. Genus 686. Axdophacus,^ n. gen. Definition. — A u 1 o sph 33 ri da with triangular meshes in the network, the tangential tubes of which form a simple, lenticular, biconvex lattice-shell, with shortened vertical main axis. Radial tubes arise at its nodal points. The genus Aulophacus differs from the common Aulos2)h(era, its ancestral form, only in the lenticular comj^ression of the spherical lattice-shell, the vertical axis of which is considerably shortened. It exhibits therefore to the latter the same relation as Cenodiscus does to Cenosp>]i(Bra among the Sphasroidea. The contrary condi- tion is shown in the following genus Atdatractus, in which the vertical axis is prolonged. In the two species of Aidophactts observed the radial spines exhibit a remarkable peculiarity, being longer on the circular periphery of the lens, shorter on both its faces, and shortest in the vertical main axis. 1. Aidophacus lenticularis, u. sp. (PL 111, fig. 5«). Shell biconvex, lenticular, with rounded circular margin ; its horizontal diameter three times as great as its thickness (or its vertical main axis). Eadial tubes cylindro-conical, straight, with six to nine triradiate verticils, those of the margin of the lens twice as long as the smooth tangential tubes, the others shorter. Dimensions. — Horizontal diameter of the lens 5T) mm., vertical main axis 0'2 ; length of the radial tubes 0-2, breadth O'Ol. Habitat. — Indian Ocean, Belligemma, Ceylon (Haeckel) surface. 2. Aidophacus amphidiscus, n. sp. (PI. Ill, fig. 5b). Shell discoidal, slightly biconvex, with rounded circular margin ; its horizontal diameter five times as great as its thickness. Eadial tubes cylindrical, covered with numerous short thorns, those of the margin of the lens three times as long as the smooth tangential- tubes, the others shorter. ' Aulophacus = Tnhula.T lens ; ctvT^o;, 4MZonm= Tubular object; au'hoc, utlon. (ZOOL. CHALL. EXP.— PART XL. — 1886.) Rr 205 1634 THE VOYAGE OF H.M.S. CHALLENGEE. 2. Aulonia j^entagonia, ii. sp. Meshes subregular, pentagonal, intermingled with a smaller number of quadrangular and triangular irregular meshes. Bars cylindrical, of equal breadth. Dimensions. — Diameter of the spherical shell 2"8 to 3'2, of the me.shes 0'15 to 0'2 ; breadth of the bars 0-01. Halitat. — South Pacific, Stations 293 to 302, depth 1375 to 2270 fathoms. 3. Aulonia hexagonia, n. sp. (PI. Ill, fig. 1). Meshes regular or subregular, hexagonal, often intermingled with a variable number of pentagonal and heptagonal meshes. Bars cylindrical, of equal breadth. Dimensions. — Diameter of the spherical shell 2'5 to 3"3, of the meshes 015 to 0'25; lireadth of the bars 0-012. Habitat. — Tropical Atlantic, Stations 347 to 349, surface. 4. Aulonia metagonia, n. sp. Meshes subregularly alternating, larger octagonal and smaller tetragonal. The network of this remarkable species has a striking similarity to the arrangement of the radial tubes in some species of Sycon, figured in my Monograph of the Calcispongias (1872, Bd. iii., Taf Ix. fig. 12). Dimensions. — Diameter of the sphere 4'4, of the greater octagonal meshes 0"24 to 0'3, smaller tetragonal 01 to 012 ; breadth of the bars 0'007. Habitat. — Indian Ocean, Cocos Islands (Eabbe), surface. 5. Aulonia polygonia, u. sp. Meshes irregular, polygonal, variable in form and unequal in size ; the majority usually pentagonal or hexagonal, but numerous intermingled meshes with three, four, seven, or eight sides. Very variable in the size of the bars and the form of the meshes. Dimensions. — Diameter of the sphere 2"5 to 5-5, of the meshes 01 to 0'2 ; breadth of the bars 0-008 to 0-12. Habitat. — Cosmopolitan ; Atlantic, Indian, Pacific, surface. Geuus 689. Aulastrum,^ n. gen. Definition. — Au 1 os p h se ri da with polygonal meshes in the network, the tangential tubes of which form a simple lattice-sphere. Radial tubes arise at its nodal points. 1 ^wZ(::s')'Ms = TuLular star ; «u?n{f, iSirTroii. REPORT ON THE EADIOLARIA. 1635 The geuus Aidastrum diU'ers from the preceding Aidoiila, its ancestral form, only in the development of radial spines at the nodal points of the simple lattice-sphere. It exhibits therefore to the latter the same relation as Aulosph(era does to Aularia. But the meshes of the spherical network are constantly triangular in the two latter genera, polygonal in the two former. The different species of Aulastrum are much rarer, and are not so diflercutiatcd as those of the common Aulosphcera. 1. Aulastrum monoceros, n. sp. Eadial tubes siniple, smooth, straight, cylindro-conical, about as long as the smooth tangential tubes or somewhat longer. Meshes of the network irregularly polygonal, the majority usually pentagonal or hexagonal. Dimensions. — Diameter of the sphere 3'0 to 4-0, of the meshes O'lo ; breadth of the tubes 0-012. Habitat. — Tropical Atlantic, Stations 347, 348, depth 2250 to 2450 fathoms. 2. Aidastrum dichoceros, n. sp. Eadial tubes cylindrical, more or less curved, undulate, smooth, twice as long as the smooth tangential tubes, forked at the distal end, with two divergent curved branches. Meshes of the net- work subregular, hexagonal (as in Aulonia hexagonia, PI. Ill, fig. 1), intermingled with single pentagonal and square meshes. Dimensions. — Diameter of the sphere 2-0 to 2-5, of the meshes 0-12 to 018 ; breadth of the tubes 0-01. Habitat. — Antarctic Ocean, Station 157, depth 1950 fathoms. 3. Aulastrum dendroceros, n. sp. (PI. Ill, figs. 4o, h, c). Eadial tubes cylindrical, straight or slightly curved, thorny, forked at the distal end, two to three times as long as the thorny tangential tubes ; the thorns are short and thin, partly simple, partly in-egularly branched and scattered, arborescent. Meshes of the network irregularly polygonal, the majority pentagonal or tetragonal. Dimensions. — Diameter of the sphere 2-4 ; radial tubes 0-2 to 0-3 long, 0-02 broad. Habitat. — North Pacific, Station 241 to 244, surface. 4. Aidastrum triceros, n. sp. (PI. Ill, figs. 3, 3a). Eadial tubes cylindrical, straight, smooth, alwut twice as long as the smooth tangential tubes, armed with three divergent curved teeth at the distal end. Meshes subregular, pentagonal, inter- mingled with a small number of tetragonal and hexagonal meshes. Dimensions. — Diameter of the sphere 1-2 to I'S ; radial tubes 015 long, O'Ol broad. Habitat. — Tropical Atlantic, Station 349, depth 2450 fathoms. 1636 THE VOYAGE OF H.M.S. CHALLENGER. 5. Aulastrum trichoceros, u. sp. Eadial tubes slender, straight, cylindro-conical, about twice as long as the smooth tangential tubes, armed with six to eight verticils of lateral branches, each of which is composed of three short curved branches (similar to those of Aulophacus lenticular is, PI. Ill, fig. 5rt). Meshes irregularly polygonal, the majority tetragonal, intermingled with pentagonal and triangular meshes. Dimensions. — Diameter of the sphere 2'2 ; tangential tubes 0'12 long, 0'007 broad. Habitat. — South Pacific, Station 289, depth 2550 fathoms. 6. Aulastrum tetraceros, n. sp. Eadial tubes straight, cylindrical, about three times as long as the smooth tangential meshes, armed with three to six subregular cruciate verticUs of branches, each of which is composed of four short, regularly crossed branches, bearing at the end a spinulate knob (similar to those of Aulatractus fusiformis, PI. Ill, fig. 65). Meshes subregidar, square, intermingled with single pentagonal and hexagonal meshes. Dimsnsions. — Diameter of the sphere 1"5, of the meshes 012 to 0'16 ; breadth of the bars O'OOS. Habitat. — South Atlantic, Station 318, depth 2040 fathoms. 7. Aulastrum pentaceros, n. &]). Eadial tubes straight, cylindrical, smooth, about as long as the smooth tangential tubes, armed at the distal end with a corona of five curved teeth (of the same shape as in Cannosphccra atlantiea, PI. 112, fig. 6). Meshes subregular pentagonal (intermingled with single tetragonal, hexagonal, and heptagonal meshes). Dimensions. — Diameter of the sphere 5'0, of the meshes 0"2 ; breadth of the bars O^Olo. Habitat. — Indian Ocean, Madagascar (Eabbe), surface. 8. Aulastrum 2^olyceros, n. sp. Eadial tubes spindle-shaped, tapering from the broader middle towards both ends, spiny, twice as long as the spiny tangential tubes, armed at the distal end with a corona of twelve to twenty divergent curved teeth (similar to the radial tubes of Auloscena tentorium, PI. 110, fig. 6). Meshes irregular, polygonal, very variable in size and form. All tubes of this species are armed with scattered, short, conical spines. Dimensions. — Diameter of the sphere 4-5, of the meshes 01 to 0-2 ; breadth of the bars 0'006. Habitat. — Central Pacific, Station 271, depth 2425 fathoms. REPORT ON THE RADIOLARIA. 1637 Genus 690. Aidodictyum} Ilaeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. 6. Definition. — A u 1 o s p li k r i d a with polygonal meshes in the network, the tubes of which are connected in different directions and form the spongy wall of a spherical shell. No radial tubes prominent over the surface. The genus AuJodidyum dilfers from Aulonia, its ancestral form, in the develop- ment of a spongy framework in the thickened wall of the spherical lattice-shell. It bears therefore to the latter the same relation as Auloplegma does to Aularia. But the outer surface of the hollow sphere is in Aidodictyum completely smooth, as well as the inner, and bears no radial tubes. Only one species of this genus has been observed. 1. Aidodictyum hydrodictyum, n. sp. Shell spherical, smooth on the outer and inner surfaces, composed of an irregular framework of straight and smooth cylindrical tubes ; its meshes very in-egular, of unequal size and various forms. The diameter of the sphere is about six or eight times as great as the thickness of its reticular wall. Dimensioiis. — Diameter of the sphere 2 to 3, of its meshes 01 to 0'2 ; breadth of the bars 0-01. Halitat. — Antarctic Ocean, Station 157, depth 1950 fathoms. Family LXXVII. C a n x o s p h ^ r i d a, Haeckel (PI. 112). Gannosphm-ida, Haockel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. G. Definition. — Ph.eodaria with two concentric spherical or subspherical shells, which are connected by numerous thin, tubular, radial beams. Inner shell simple, spherical or ovate, solid or latticed, with a peculiar mouth. Outer shell spherical or polyhedral, articulate, composed of hollow tangential tuljes, which are separated by astral septa at the stellate nodal points. From the latter arise hollow radial tubes, whilst the inner radial beams, connecting the two shells, are inserted in the middle of the tangential tubes. No peculiar mouth in the outer shell. Central capsule enclosed by the inner shell. The family C a n n o s p h se r i d a comprises a small number of remarkable Ph^odaria which are rare and found only in a few localities. They diifer from all the other Ph.eodaria in the possession of two concentric spherical shells, which are connected by radial beams, and the inner of which is quite simple, like that of the Medusettida, 1 Aulodklymn = T\\hvL[ax net ; uv7\6;, o/xtvoi'. 1638 THE VOYAGE OF H.M.S. CHALLENGER. whilst the outer is articulated and composed of hollow tangential tubes, like that of the Aulosphasrida. This latter family seems to be most nearly allied to the Cannosphairida, and is perhaps derived from them by loss of the inner shell. The possession of a peculiar mouth in this inner shell brings the Cannosphterida nearer to the Phseogromia. The similar Ccelodrymida, in which also two concentric sphserical shells are connected by hollow radial beams, differ essentially in the bivalved shape of the inner shell and the simple, non-articulated, network of the outer shell. Only a single species of Cannospha^rida has been hitherto known, described and figured in 1879 by R. Hertwig as Ccelacantha anchorata (loc. cit., p. 92, Taf. ix. fig. 2). The rich collection of the Challenger has added to it only four other species, one of which is most nearly allied to the former, whilst the others Ijelong to a separate genus, Cannosjohcera (PI. 112). The inner shell is in this latter genus a solid lamella of silica, whilst in the former it is fenestrated. In all other essential points of structure both genera ai'e scarcely different. The inner shell is either spherical or ovate and has a diameter of O'l to 0"4 (usually 0*2 to 0*3 mm.). A distinct main axis is always marked by the large open mouth on its oral pole. The aboral part of the shell-cavity contains the spherical central capsule, the oral part the dark ph^eodium, a part of which is often prominent through the mouth (figs. 1, 2, 4). The wall of the inner shell is a very thin and transparent lamella of silica, which is structureless and solid in Cannosph(Bra, distinctly fenestrated in Ccelacantha ; the pores of the latter are irregularly rounded and seem to possess a thickened margin. From the surface of the ijiner shell ai'ise numerous thin, tubular, radial beams (twenty to eighty or more) and connect it with the outer shell. These beams are always very thin and straight cylindrical tubules, about twice to four times as long as the diameter of the inner shell, and usually O'OOl mm. broad, or even less. Their basal end at their origin from the inner shell is more or less dilated, often funnel-shaped, so that the surface of the latter appears mammillated (figs. 2, 4). The cavity of the inner shell seems to pass over immediately into the tubular cavities of the radial beams. These latter are sometimes simple, at other times articulated or jointed by a number of transverse septa. The radial beams are covered in all the species observed either with scattered spines (fig. 5) or with verticils of anchor-threads, very thin, filiform, lateral branches which bear a spathilla with three or four recurved teeth on the distal end (figs. 2, 4). The outer shell is either spherical or an endosp>herical polyhedron, the prominent nodal points of which fall into a spherical face. Its diameter -is usually from 2 to 3 mm., rarely more than 3 or less than 1 mm. Its structure is the same as described for the Aulosphajrida, being composed of hollow cylindrical tubes, which form a loose network and are separated at its nodal points by astral septa. The meshes of the network are REPORT ON THE RADIOLARIA. 1639 very large, usuall}' twice to three times as broad as the inner shell, and irregulai'Iy polygonal; the usual and prevailing form is pentagonal, but hexagonal meshes are also often intermingled, more rarely meshes with four, seven, or eight sides. The cylindrical tangential tulies possess in general the same shape as in the similar Aulosphserida, have a thin wall, are filled by jelly, and contain a delicate axial filament in their axis ; they difi"er, however, in a peculiar constant character ; in the middle of each tube is inserted an inner radial beam coming from the inner shell, so that both together have the form of a T. The central point of insertion has a somewhat shorter radial distance from the centre of the body than the two nodal points on both ends of the tangential tube, so that the latter is slightly geniculate (figs. 1—5). The two halves of each tangential tube are usually somewhat thinner on the central end (where the inner radial lieam is inserted), thicker on the distal end (where the outer radial tube arises) ; at both ends they are closed by a thin transverse septum. Often also some other septa are developed, so that each tangential tube seems to be composed of four to six joints or segments. Usually the tangential tubes are armed with spines or anchor-threads, similar to those of the inner radial beams. The length of the single tangential tubes is usually between 0"1 and 0"3, their diameter from O'Ol to 0"02. The nodal points of the outer lattice-sphere, in which the outer radial spines arise, seem to possess the same structure as in the similar Aulosphserida. Since three tangential tubes are connected in each nodal point, in its centre is the union of three small astral septa or sutural partitions. The small nodal cavity on the inside of the nodal point has probably three small pores, which lead into the three tangential tubes between the three astral septa. A fourth pore probably leads from the nodal cavity into the cavity of the hollow radial tube. This structiire is difficult to observe, but seems to be demonstrated by the fact, that in the complete and carefully purified skeletons which are treated with hot mineral acids and afterwards dried, all cylinders, the tangential as well as the radial tubes, become easily filled by air (compare the descrip- tion of the similar structure in the Aulosphserida). The external radial tubes which arise in the nodal points of the outer shell are either cylindrical or cylindro-conical, straight, and usually about as long as the diameter of the inner shell. Their structure and armature is the same as in the similar Aulosphserida. In the axis of each radial tul^e runs a delicate axial filament, which is connected with its thin and fragile wall either by filiform transverse branches or by delicate transverse septa. The outside of the radial tubes is either smooth (figs. 3—5) or armed with scattered spines (fig. 4) or with verticils of lateral branches ; each verticil is usually composed of three or four branches. The distal end of the radial tubes is rarely simple, pointed ; it is usually armed with a spathilla of three or four curved terminal branches (figs. 3, 5) sometimes with an elegant corona composed of twenty to thirty thin radially divergent branches (fig. 4). 1640 THE VOYAGE OF H.M.S. CHALLENGER. The central capsule of the Camiosphaerida is small (of O"! to O'lo in diameter) and hidden in the aboral half of the enclosing inner shell, whilst the oral half of the latter is filled up by the phseodium (figs. 2, 4). The structure of the capsule and of its three openings seems to be the same as in the closely allied Aulosphaerida. I have, however, not been able to recognise the two parapylse or secondary openings, and have only observed the astropyle or the main-opening w^ith its radiate operculum surrounded by the phaeodium, and directed with its tubular proboscis towards the mouth of the inner shell. As R. Hertwig also could not recognise the two parapylse, it is not impossible that they are wanting, and that the Cannosphserida possess only one opening, the astropyle, like the Medusettida and Challengerida. The nucleus, enclosed in the central capsule, is spherical, half or one-third as liroad as the latter, and contains numerous nucleoli. Synopsis of the Genera of Cannosphmrida. Internal shell solid, without open pores, ...... 691. Cannosphcera. Internal sheU latticed, with open pore?, ...... 692. Caelacantha. Genus 691. Cannosphcera,^ Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. 6. Definition. — C a n n o s p h te r i d a with a solid, not latticed internal shell. The genus Cannosphcerct comprises those Cannospha^rida in which the inner shell is formed by a thin solid siliceous-plate and exhibits no pores between the prominent bases of the radial beams. 1. Cannosp>hcera atlantica, n. .sp. (PI. 112, figs. 5, 6). Internal shell not niammillate, with fifteen to twenty radial I'ods, which are loosely studded with single, scattered, simple, lateral spines. External shell with irregular, mostly hexagonal meshes, armed with numerous scattered forks of paired divergent spines, and with twenty to thirty larger simple radial spines, which are about half as long as the internal rods, and bear at the distal end a verticil of three to live curved, simple, terminal branches. Dimensions. — Diameter of the inner shell O'l, of the outer 0'5. HaUtat. — Tropical Atlantic, Stations 347 to 349, depth 2250 to 2450 fathoms. 2. Cannosphcera antarctica, u. sp. (PI. 112, figs. 1-3). Internal shell mammillate, with sixty to ninety radial rods, which are studded with cruciate verticils of tridentate anchor-threads. External shell with irregular, mostly pentagonal meshes, ' Ccm)iosp/i(Era = Sphere with tubules ; xxi^i/cc, ctpxl^a. REPORT ON THE RADIOLARIA. 1641 the bars of which bear ou tlie outside bunches of similar tridentate anchor-threads. At each nodal point arises a simple, smooth, radial spine, which bears at the distal end a verticil of three or four small, curved, terminal branches. Dimeyisions. — Diameter of the inner shell 0-2 to 0-3, of the outer 1'5 to 2'0. Habitat. — Antarctic Ocean, Stations 154 to 157, depth 1300 to 1975 fathoms. 3. Cannosjihceva 2^'-('Cifica, u. sp. (PI. 112, fig. 4). Internal shell mammillate, with one hundred to one hundred and twenty radial rods, which are studded with cruciate verticils of tridentate anchor-threads. External shell witli irregular, mostly- hexagonal meslies, the bars of which bear on the outside and on the inside bunches of similar tridentate anchor-threads. At each nodal point arises a simple, thorny, radial spine, which bears at the distal end an elegant verticil of fifteen to twenty flatly expanded, thin, terminal branches. Dimensions. — Diameter of the inner shell 0'25 to 0'35, of the outer 2'0 to 2'5. Habitat. — Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms. Genus 692. Coelacantha ,i R. Hertwig, 1879, Organism, d. Eadiol., p. 91. Definition. — C annosphserida with a latticed internal shell. The genus Coelacantha comprises those Cannosphserida in which the inner shell is formed by a fenestrated flint-plate, and exhibits numerous pores between the prominent bases of the radial beams. 1. Coelacantha anchorata, R. Hertwig. Caelacantlia anchorata, R. Hertmg, 1879, Organism, d. Eadiol., p. 92, Taf. ix. fig. 2. Internal shell slightly mammillate, with thirty to forty radial rods, which are densely studded with verticils of tridentate anchor-threads. External shell with irregular, mostly pentagonal meshes, the bars of which bear the same verticils, each composed of three thin, tridentate anchor- threads. At each nodal point arises a slender radial spine, which bears six verticils, each composed of three to five lateral branches! Dimensions. — Diameter of the inner shell 0'5, of the outer 3-0. Habitat. — Mediterranean, Messina (R. Hertwig), surface, 2. Coelacantha mammillata, n. sp. Internal shell strongly mammillate, with sixty to eighty radial rods, which are densely studded with cruciate verticils of quadridentate anchor-threads. External shell with irregular, mostly 1 C'(«fac««ite=Hollow spine ; koiT^os, kkxv^x. (ZOOL. CHALL. EXP. — PART XL. — 1886.) Er 206 1642 THE VOYAGE OF H.M.S. CHALLENGER. hexagonal meshes, the bars of which bear the same verticils, each composed of four tliin quadri- dentate anchor-threads. At each nodal point arises a slender, smooth, radial spine, which bears at its distal end a verticil of four large, curved, terminal branches. Dimensions. — Diameter of the inner shell 0'4, of the outer 3"2. Habitat. — South Atlantic, Station 332, depth 2200 fathoms. Order III. PHiEOGROMIA, Haeckel, 1879. Definition. — Ph^odaria with a simple, not bivalved lattice-shell, which assumes very diflferent forms, but is always provided with a peculiar mouth and peristome on the oral pole of the main axis. Central capsule always excentric, placed in the aboral half of the shell-cavity. Family LXXVIII. Challengerida, John Murray (PL 99). Ghallengerida, John Murray, 1876, Proc. Eoy. Soc. Lond., vol. xxiv. p. 471, pi. xxiv. figs. 1, 2. Definition. — Ph^odaeia with a monaxonial, usually ovate or lenticular shell, which exhibits a peculiar, fine, regularly hexagonal, diatomaceous structure, and is usually provided with teeth on the mouth, but without articulated feet. Central capsule excentric, placed in the aboral half of the shell-cavity. The family Challengerida represent a large, peculiar, and interesting group of Ph.