sTeteibie ghee AMPHIPODA weararigsrsssssae) | ‘BOVALLIL 1s a 1886 1 sant TG Das < MG SphNaY cr yl a a Ay, a kala / oo et | a SS ee eee %. Rathbun AMPHIPODA “SYNOPIDEA BY Stop) aa Or oP ak . Pay CARL BOVALLIUS. "ea WITH 3 PLATES. (PRESENTED TO THE ROYAL SocteTY OF ScleENcES OF UPSALA THE 10th May 1886.) 7+ : ; ae its Nova Acta, a. sev, vel. 13, “ot — ~ UPSALA. PRINTED BY EDV. BERLING. 1886. — NIAN INST i>, 8) AAS e 7 , . 7 7 << ; 2 - es > we ore 7 “fa ke 7 im 2 Se ee ree, Dorey WF Pere, ¢°@s Vo Be a ee . ra ) are | ee Oe ee eG el -_— wae. 6 6 ; aa? —_ <7 a> yl Cee - y es a a 7 c + a ae ‘@ - - : = a a ie. 7) ; = = eS - - 7 i? a 7 ‘ on a vi i a) Sais ~ ‘= ' a © See a eee es 2 - _ - - 7 lS a aad - oo a - ; 7 r 2 i _—- - @ ee Sie ee fe 7 = y a me a) > _ 7 » > <& — 7 a le = > = . = ‘ a? aw Cd ant os - _ _ a = “oe Ca - — , : 7 ' - x 7 - ah a aoa — + sr Tran A 7) a * ne ie ol, 0 a 7 a ~ 7 re a 7 7 > : 2 _ eo. eee nr «+ - = : «,” Pe 7 Se - wr > a = nr A. _ a 7 a. CA ~ Ff / a - coal _ _ vy 7 - 7 ’ *% a 7 ; 2 ; ae . : av : - - ae Oy frye : zo - _ a a 7 i 7 ‘ i . 7 a] 7 7 > a ~ lee : : : & : > zy a f oo = | 7 : .- 7» 7 s _ i 7 a - rw 2 ae ee : 7 aan 7 Me ' , oe y.. — —- 7 : am! 7 7 So i y- My 7 “ -. - 7. iP an 7 : _: e =e - — ) 7 a 7 | 7 ie ° a , i. - . 7 — 7 vo ‘ff : 7 ad rs al ow oF | 7 awl 1 he f a c is aa lL * vis 7 » ar ; : 7 y 7 iT u . 7 & - - aa - 7 _ Pi a a ks a , © = » rs 7 7 : - - ° = — 7 _ 7 we fo nee > ’ *. 5 . ae . Wis 7 s * es 4a 7 : S rY 7 a a - » agen : - ee = — 7 _ k - - Y , a A 2 Tae a 7 oa = “a ‘ a) = » 7 Te = : : - ‘7s ; ; i ; > a = _ oo! ' a 9 =< “ a al 7 _ - 7 - 7 | 7 : ae s with the author's best reg ( SODODOADODOOX DOGO II TBO OID OA Se ay 1 OP Me “I XX Seo, Gp, > a> > 0 E>. 0 is > AL DOW >.>

3 a wer a | Sy ST — 4%. Rathbun. : ; AMPHIPODA SYNOPIDEA ui ay N ZOOLOC i \ Crustacea CARL BOVALLIUS. BY IN /ERTEBR AT WITH 3° PLATES. Q) SO 4 Oo (PRESENTED TO THE Royat Sociery oF Sciences oF UpsaLaA THE 10th May 1886.) NAO OOOO v D> NI NF ON 890803 . qe ze Be se eae HEE Ae VOODOO IO OOOD OOOO AAD arose st = eae - SMITHSONIAN INSTITUTIOS WASHINGTON 25, D.C. Introduction . . .. . Amphipoda Synopidea. . Diagram of the families . . . First family, Synopide . SOC ara Diagram of the species . . Se UUTAMOTING -2 +. CORAUUICE: 2s Me SCN CCIE! eg ew a OTUCNMOS vote 0hGl ln De GQNGUSTLTTONS . 9. 5. S. ortentalis CONTENT. Second family, Trischizostomatide Trischixostoma . . i Rhaschit 2 . : Third family, Hyperiopside Hy periopsis i Voermngu ..:. Explanation of the plates. . Pag. Abbreviations. SM. = Collections of the Royal Swedish State Museum at Stockholm. DM. = » » the Zoological Museum of the University at Copenhagen. UM. = » » the Zoological Museum of the University at Upsala. NF » » the Zoological Museum of the University at Christiania. CE — > » the author. M, researches on the relations of the different forms of Amphipoda Hyperiidea to one another and to the other Amphipoda have induced me to establish a new tribe of Amphipoda, intermediate between the Gam- maridea and the Hyperiidea. I propose to name it Amphipoda Syno- pidea. In my opinion the Amphipoda thus ought to be divided into five tribes, with the following diagnoses: 1. Amphipoda Tanaidea. Caput cum segmento primo perei coalitum. Oculi minuti in lobis diseretis siti, vel nulli. Antenne superiores flagello secundario instruct vel destitute. Pedes maxillares in unum coaliti, palpum quattuor-articulatum gerentes. Lamine branchiales pedibus maxillaribus affixee. Pleon seepe quinque-articulatum. Urus maximum. Telson nullum. II. Amphipoda Gammaridea. Caput cum segmento primo pereii non coalitum. Ocul mediocres, sessiles. Antenne superiores flagello secundario seepissime instructee, Pedes maxillares non coaliti, palpum quattuor-articulatum gerentes. Vesicule branchiales pedibus pereii aftixe. Pleon tri-articulatum. Urus mediocre, tri-articulatum. Telson seepissime fissum. II. Amphipoda Synopidea. Caput cum segmento primo pereii non coalitum. Oculi grandes, maximam partem capitis occupantes, sessiles. Antenne superiores flagello secundario instructe, Pedes maxillares plus minusve coaliti, palpum quattuor-articulatum gerentes, Nova Acta Reg. Soc. Sc. Ups. Ser. III. 1 2 Cart Bovat.ivs, Vesicule branchiales pedibus pereii affixe. Pleon tri-articulatum. Urus tri-articulatum. Telson simplex vel leviter fissum. IV. Amphipoda Hyperiidea. Caput cum segmento primo pereii non coalitum. Oculi seepissime grandes, maximam partem capitis occupantes. Antenne. superiores flagello secundario carentes. Pedes maxillares 1 unum coaliti, palpo carentes. Vesicule branchiales pedibus pereii affixe. Pleon tri-articulatum. Urus bi- vel raro tri-articulatum. Telson simplex non fissum. VY. Amphipoda Caprellidea. Caput cum segmento primo pereii coalitum. Oculé minuti. Antenne superiores flagello secundario carentes. Pedes maxillares in unum coaliti, palpum unguiculatum gerentes. Vesicule branchiales segmentis anticis pereii affixee. Pleon et urus valde reducta. Telson nullum. AMPHIPODA SYNOPIDEA. Amphipods with the head free from the first pereional segment; with large eyes, occupying almost the whole surface of the head; the first pair of antenne provided with a secondary flagellum; the maxilli- peds more or less coalesced, provided with four-jointed palps; pleon and urus divided into three segments each; telson simple or partially cleft. With the true Gammarids the animals belonging to this tribe have many characteristics in common, as the general form of the body, the secondary flagellum of the first pair of antenne, the strueture of the maxillipeds and their palps ete. (The first family, Synopide, is the most closely related to the Gammarids). Many characteristics point deci- AMPHIPODA SYNOPIDEA. 3 dedly to the Hyperids, as the structure and development of the eyes, the structure of the mouth-organs (with the exception of the palps of the maxillipeds), the form of the uropoda and the telson (especially in the last two families) a. o. Probably the new genus Hyperiopsis, lately described by G. O. Sars), is to be placed in this tribe as the type of a new family, Hy- periopsidx, and I shall preliminarily do so here, although I do not know much about the very important characteristics of the mouth-or- gans, because Sars only mentions, that the mandibles are provided with palps, similar to those of the Gammarids. Thus the tribe can conveniently be divided into three families: 1. SYNOPIDZ. 2. TRISCHIZOSTOMATIDA and 3. HYPERIOPSID&. & bifid. Synopide. not transformed. Telson The seventh pair of pereiopoda simple. Trischizostomatide. transformed. ‘'Telson simple. Hyperiopside. The first family. SYNOPIDE. Syn. 1852. Subfamily Synopine, DANA. United States Exploring Expedi- tion. Crustacea. vol. 2, p. 981. Fol. 1862. Subfamily Synopiades. SPENCE BATE. Catalogue of the specimens of Am- phipodous Crustacea in the col- lection of the British Museum. p. 341. ISSO. Subfamily Synopiade. R. KOSSMANN. = Zoologische Ergebnisse einer im Auftrage der k. Academie der Wis- senschaften zu Berlin ausgefihr- ten Reise in die Kiistengebicte des Rothen Meeres. Malacostraca. p. 137. Leipzig. 4:to. Diagn. The head is triangular, not tumid. The eyes oceupy the upper median part of the head, and are distinctly faceted. The mandibles ave well developed, with a three-jointed palp. 1) The Norwegian North Atlantic Expedition. Zoology. Crustacea. I, p. 231. Chri- stiania. 1885. Fol. 4 Cart Bova.uius, The mazillipeds, coalesced at the base, carry strong four-jointed palps. The antenne are fixed on the under-side of the head. The second pair are like those of the Gammarids. The seventh pair of peretopoda are not transformed. The wropoda are like those of the Gammarids. The ftelson is cleft to the middle. The animals belonging to this family resemble the true Gammarids in more points than those of the two following families do and are very interesting as connecting lmks. Dana‘) placed them among the Hype- rids as the third subfamily of the family Hyperide; Spence Bate”) removed them from this family and ranged them as the first subfamily of the family Oxycephalide. Claus mentions the genus 1871°) as belon- ging to the Gammarids. Kossmann‘) regarded them as Hyperids and described some particulars of their morphology, overldoked by Dana. Other authors have totally omitted the animals, which seem to be very rare and easily passed over, being very small and, as is has been men- tioned above, very similar in general habitus to Gammarids. Genus 1. Synopia. DANA, 1852. Syn. 1852. Synopia. DANA. —— United States Exploring Expedition. Cru- stacea. vol. 2, p. 994. Folio. ~ 1862. 3 Bs Spence Bate. Catalogue of the specimens of Amphipod- ous Crustacea in the collection of the British Museum. p. 341. 18S0. * & R. Kossmann. Zoologische Ergebnisse einer im Auftrage der k. Academie der Wissenschaften zu Berlin ausgefithrten Reise in die Kiisten- gebiete des Rothen Meeres. Malacostraca. p. 137. Leipzig... 4:to. 1) United States Exploring Expedition. Crustacea. vol. 2, p. 981. 2) Catalogue of the specimens of Awmphipodous Crustacea in the collection of the British Museum. p. 341. 8) »Untersuchungen iiber den Bau und die Verwandtschaft der Hyperiden», in Nachrichten von der Kénigl. Gesellschaft der Wissenschaften und der G. A. Universitit zu Gottingen, 1871, N:o 5. p. 157. 4) Zoologische Ergebnisse einer im Auftrage der kéniglichen Academie der Wissen- schaften zu Berlin ausgefiihrten Reise in die Kiistengebiete des Rothen Meeres. Mala- costraca. p. 137. Or AMPHIPODA SYNOPIDEA. Diagn. Corpus compressum, gracile. Caput angustum, triangulatum. Oculi grandes, in medio capitis confluentes, ocellis magnis. Antenne primi paris flagello multi-articulato, articulo primo valde elongato, setoso. Pedes pereté pavium quattuor priorum inzequales, setosi; ili parium trium ulti- morum elongati, subeequales, dactylis longis. Pedes wri ultimi paris ramis externis bi-articulatis. Telson maximum. The body is compressed. The head is narrow, triangular The eyes are very large, coalesced into one in the middle of the head, with distinct large ocelli. The first pair of antenne with a multi-articulate flagellum; the first joint of the flagellum very long, beset with long hairs. The first four pairs of perecopoda are unequal, setose; the three last ones subequal, elongate, with long dactyli. The last pair of wropoda with the outer rami bi-articulate. The ¢elson is very large. The genus Synopia was established in the year 1852 by Dana upon specimens captured in the tropical seas during the United States Exploring Expedition 1838—1842. He distributed them into two or rather three species, S. wltramarina, S. angustifrons and S. gracilis, the last one only conditionally, supposing that it might perhaps prove to be the male of S. ultramarina. Judging from the descriptions and drawings of Dana, compared with the alcohol-specimens of 8. ultra- marina at my disposal, I think they are different species and_ shall retain the name proposed by Dana. Spence Bate cites the two species S. ultramarina and 8S. angustifrons, with short extracts from Dana’s descriptions and copies of some of his figures. In the year 1880 R. Kossmann described some details of a Synopia from the Red Sea; he proposed for it the name S. orientalis. During the expe- dition of His Swed. Maj:s Corvette Balder, 1881—82, I cap- tured four specimens of a new species and one of S. ultramarina, some twenty miles off the East coast of Barbadoes; and in the Carib- bean Sea one specimen of another new species, closely allied to S. ultramarina and S. gracilis. Last year, in a very valuable collection of Hyperids and other pelagic Crustacea, made by Captain George von Schéele during a voyage round the world') and presented to the Zoologi- 1) In the Swedish vessel Monarch, belonging to Consul Rettig of Gefle, who in the kindest manner supported the zoological labour of Captain von Schéele. 6 Car. Bova.utus, cal Museum of the University of Upsala, I found six specimens of 8. ultra- marina in comparatively good condition. These are the chief material for my researches on this species. All the species of the genus Synopia are closely allied and seem rather to deserve the name of varieties than of species, of so small importance are the characteristics distinguishing them from one another; but as their differences seem to be constant, at least according to my experience, I am bound to describe them as distinct species. the first joint harry. rounded. Fla- the following gellum of the smooth. ie N ultramarina. shorter than the pe- Dana. reion. Femora of the fifth and sixth pairs of pereiopoda N. Sp. first pair of an- tenne with wn all joints hairy. 2. caraibica, produced an- TR -angustifrons. Dana. Synopia. | teriorly. The more or less rectangular. 3. The head is? first pair of antenne are rounded. 4.-S. Scheéleana. longer than the pe- N. Sp. reion. Femora of the fifth and sixth pairs of pereiopoda .. . . | truncate below. 5. S. gracilis. Dana. not produced anteriorly... - - 52+ +e eee ee tee et ee ee 6. S. orientalis. Kossmann. 1. Synopia ultramarina. DANA, 1852. Bl iphone ele Syn. 1852. Synopia ultramarina. DANA. —— United States Exploring Expe- dition. Crustacea. v. 2, p. 995. pl. 68, fig. 6 a—h. 1862. Spence Bate. Catalogue of the specimens of Amphipodous Crustacea of the British Museum, p. 341. pl. 54, fig. 1, ed aie Diagn. Caput triangulare, longitudine latitudinem equans, Oculi parvi supplementarii singuli supra bases antennarum primi paris siti. Antenne primi paris quam pereion multo breviores. Flagellum secundarium longitudine articulum primum flagelli (veri) equans vel superans. AMPHIPODA SYNOPIDEA. 7 Segmentum primum perei? secundo longius, segmentum sextum septimo lon- gius, omnium longissimum. Femora parium quinti et sexti pedwm pereit rotundata, fere circularia. Pedes septimi paris illis sexti breviores. Peduneuli pedwin plet elliptici. Segmentum primum «77 secundo paulo longius. Rami paris ultimi, pedwm uri longitudine inequales, parte inferiore solum marginis interioris setis instructa. Telson triangulare, apice truncato. The head is triangular, as broad as long. There is a small secondary eye on each side, at the bases of the first pair of antenne. The first pair of antenne are much shorter than the pereion; the secondary flagellum as long as or longer than the first joint of the true flagellum. The first segment of the perefon is longer than the second; the sixth is longer than the seventh, being the longest of all. The femora of the fifth and sixth pairs of pereiopoda are rounded, nearly circular. The seventh pair are shorter than the sixth. The peduncles of the pleopoda are elliptical. The first wral segment is only a little longer than the second. The rami of the last pair of wropoda are unequal in length, with the lower part only of the inner margin provided with hairs. The telson is triangular, truncated at the hinder end. There are some details in the drawings, given by Dana, which do not agree with mine, but I think it best to try to identify my specimens with the species of Dana, because in my opinion they ‘agree in the more essential characteristics. The body is strongly arched, with a thin hyaline integument, and agrees well in general habitus with the figure of Dana’s S. ultramarina. The head is triangular, seen from the side, even as from above, with two slight excavations for the insertion of the antenne. It is smaller than in the following species, a little shorter than the first three pereio- nal segments, not deeper than the pereion. The,median eye is round, composed of large ocelli, provided with distinct light-breaking elements. The number of peripherical ocelli is about twenty-four, not very distinct at the hinder margin. Over the bases of the first pair of antenne there is on each side a little secondary 8 Cart Bova.uius, eye, detached from the head mass probably in an early period of the development; it is composed of three ocelli. The pigment is deep black. | The first pair of antenne [Pi. I, fig. 2] are a little different in the male and the female; the peduncle is three-jointed, the first joint thick and long, the second scarcely as long as half the first, the third as long as half the second. The secondary flagellum consists of two joints, the first thick, five times longer than the second, beset with five to six bristles. In the male it is longer than the first jomt of the true flagellum, in the female it equals the same joint in length. [Pl. J, fig. 3). The true flagellum consists of a long, conical, a little tumid joint, like that of the genus Hyperia, carrying long hairs; then follow in the male nine, in the female four narrow joints, the terminal being the longest, with a long hair at the apex. In the male the first pair of antenne reach to the anterior margin of the fifth segment, in the fe- male scarcely to that of the fourth. The second pair of antenne [pl. 1, fig. 2 a] are about twice longer than the first. The first jomt of the peduncle is rounded, as long as broad, the second very short, the third linear, as long as the two pre- ceding together, the fourth is the longest, with minute hairs along the anterior margin, the fifth as long as the third, with a long hair at the lower anterior corner and minute ones along the anterior margin. The flagellum consists in the male of 18, in the female of 12 articuli, in the male every one carries two minute hairs at the upper anterior corner. The flagellum is longer than the peduncle. The second pair of antennz reach in the male to the first ural segment, in the female to half the second pleonal segment. The mouth-organs are well developed, constructed for mas- tication. The labrum [Pl. I, fig. 4] is divided mto two semicircular pro- jections, which are fringed with strong hairs, feebly curved at the ends. The mandibles [Pl. I, fig. 5] are very strong; a little beyond the middle projects a thick, rounded, molar tubercle, whose grinding surface is provided with 10 curved, strongly denticulated crests [Pl. I, fig. 6]; at the outer side of the molar tubercle there is a bundle of denticu- lated spines and bristles. Then follows a deep excavation with a row of five long bifid spines [Pl. I, fig. 7]; the end of the mandible consists of a hollowed process, denticulated at the apex. From the middle of the outer margin of the mandible projects the three-jointed palp; the AMPHIPODA SYNOPIDEA. 9 first joint is very short; the second very long, tumid, irregularly ovate, carrying a single plumose hair near the outer end; the last Jot 1s mi- nute, scarcely a tenth of the length of the preceding, with two very long, plumose hairs at the tip. At the base of the mandibular palp there are two strong, denticulated, masticatory projections. The first pair of maaille [Pl. I, fig. 8] consist of a short basal joint and two robust laminz; the outer one is the longest and broadest, carrying a row of nine to ten strong spines at the end, and another row of six spines a little behind, near the middle of the lamina. The inner lamina is fringed with long hairs along the inner margin, and carries a row of 7—8 unequal spines at the end. The second pair of mazille [Pl. I, fig. 9] consist of two lamine; the inner is the larger, ovate, with a row of five peculiar, denticulated spines at the end [Pl. J, fig. 10], and a longitudinal row of 14—15 long, simple spines on the inner side of the lamina. The inner lamina is obleng, with about a dozen long bristles at the top. The mawillipeds [P\. I, fig. 11] are very large, when closed, totally covering the other oral organs. The basal joints are coalesced, the following free; both lamine are ovate, fringed with long, plumose hairs, the first along the inner, the second along the outer margin. The palp is four-jointed, the first joint is short and thick, the second three times longer than the first, fringed along the outer margin with long, plumose hairs. The third joint is narrower, half as long as the second, with long, simple hairs at the end; the fourth joint is very minuie, about a fifth of the length of the preceding. The pereion. The first segment is a little longer than the second, but shorter than the third, the third to fifth are equal, the sixth is much longer, longest of all, the seventh segment is longer than the fifth. The surface of the segments is very smooth, the posterior corners are feebly rounded. The epimerals (Pl. 1, fig. 1) are well developed, but very thin and totally pellucid; they are very easily overlooked, which may be the reason why they are not described by Dana, but only mentioned in the explanation of the plates and figured from the third segment together with the correspondent leg. (Dana l. c. p. 996, pl. 68, fig. 6, e). The epimerals of the first and second segments are as long as the segments, of an irregular shape and only half as deep as long. The epimerals of the third segment [PI. I, fig. 13] are enormously de- veloped; they are quadrangular with the upper corner (the articulation with Nova Acta Reg. Soc. Sc. Ups. Ser. III. 2 10 Cart Bova..ius, the segment) truncate, and the hinder margin excavate. At the inside of the upper corner is a tuberculous prominence, against which the upper end of the femur articulates; the epimeral is as deep as the length of the femur of the correspondent leg, quite as large as the femur of the fifth pair. The epimerals of the fourth segment are scarcely as long as the segment [PI. I, fig. 14], deeper than long, the anterior margin rounded, the posterior straight; at the middle of the upper margin there is on the inside of the epimeral a tubercular projection for the arti- culation with the leg. The epimeral reaches as far down as half the length of its femur, and is partly concealed by the femur of the fifth pair of pereiopoda. The epimerals of the fifth and sixth segments are longer than the segments, rounded at both ends, more than twice longer than deep; the posterior portion is a little deeper than the anterior. The last epimerals are shorter than the segment and smaller than the preceding, but of the same form. [PI. I, fig. 17]. The branchial sacks are fixed at the bases of all the pereiopoda with the exception of the first pair. Those of the second to fourth seg- ments [Pl. I, fig. 14] are longer than the corresponding femora and very large, the following [Pl. I, fig. 15 and 16] equal the length of the femora and are more slender. The ovitectrices [Pl. I, fig. 18] are attached to the bases of the second to sixth pairs of pereiopoda; they are long, narrow lamine, a little broader at the lower ends, feebly bent inwards. They carry 8—12 long, simple hairs around the lower ends. They are a little shorter than, the corresponding branchial sacks. The first pair of pereiopoda [Pl. I, fig. 12]. The femur is long and narrow, a little broader at the lower end, with two plumose hairs at the lower anterior corner; the genu is short, the tibia twice longer. The carpus is very large, dilated, nearly ovate, more than twice longer than the two preceding joints together and fully as long as the femur. It carries a single long hair at the lower anterior corner; the hinder mar- gin is nearly semicircular, bordered with 14 plumose hairs, which are as long as half the breadth of the joint; at the lower posterior corner there is a long, plumose hair, longer than the metacarpus. The meta- carpus is very dilated, with the anterior margin feebly, the posterior strongly curved; it is only a third longer than broad. The hinder marein is fringed with 14 plumose hairs and, at their bases some short, simple hairs. At the lower end of the joint around the dactylus AMPHIPODA SYNOPIDEA. 11 there are 3—4 long, simple hairs, longer than the dactylus. The dactylus is strong, feebly curved, only a little shorter than the metacarpus. The second pair. The femur is long, narrow, smooth; the genu is very short, the tibia more than twice longer, smooth. The carpus is longer than the femur, more than five times longer than broad, the an- terior margin straight, the posterior feebly curved and provided with very strong, plumose bristles; at the upper third of the joint these bristles are geniculate, six in number; at the lower part they are straight, very long, 8—10 in number. The metacarpus is longer than halt the carpus, a little dilated, four times longer than broad. The anterior margin 1s nearly straight, the posterior irregularly curved, fringed with 10—12 strong, plumose bristles, longer than the breadth of the joint. At the lower end there are two long, simple hairs on each side of the dactylus, as long as the metacarpus itself. The dactylus is very small, shorter than a sixth of the length of the preceding joint, pedunculated; the peduncular part is a little longer than the claw. The third pair (Pl. I, fig. 13]. The femur is as long as the epi- meral is deep, broader at the posterior margin; the genw is short, the tibia very long and broad, laminar, with the hinder margin strongly curved, the anterior straight, smooth, with a single simple hair at each of the lower corners. The carpus is broad, ovate, laminar, the hinder margin fringed with !0—11 unequal, plumose hairs; it is longer than the tibia (16: 13). The tibia and carpus together equal the length of the femur. The metacarpus is narrow, nearly linear, shorter than the carpus (13: 17), the posterior margin with three simple hairs. The dactylus is a little longer than half the metacarpus, pedunculated; the peduncular part is elongate, lanceolate, more than twice as long as the claw, which is feebly curved, sharp. The fourth pair [P1.1, fig. 14]. The femur is elongate-elliptical, very narrow at the upper end, with a long, simple hair at the lower posterior corner. The genu is short, with a plumose hair at the posterior margin. The tibia very broad, laminar, triangular with rounded corners, broader than long (14:9), with a plumose hair at the hinder margin and a long simple one at the anterior corner. The carpus is long and very broad, laminar, the anterior margin is straight, the under margin nearly straight, the hinder margin curved, and the upper margin excavated. It is scarcely a third longer than broad. Along the lower and hinder margins there is a row of 15 plumose hairs, the longest shorter than the breadth of the joint. The metacarpus is elongate-ovate, longer than half the carpus, with four 12 Cart Bovauius, short, plumose hairs at the lower end. The dactylus is a little shorter than the metacarpus (8: 11), pedunculated, of the same shape as in the preceding pair. The fifth pair [Pl. I, fig. 15}. The femur is rounded, nearly cir- cular, a little longer than broad (13: 11), the hinder margin is quite smooth, the anterior carrying three short hairs. The genw is short, the tibia broad, three times longer than the genu, the hinder margin feebly curved, with a short spine at the lower corner, the anterior margin straight with 3—4 spines. The carpus equals the tibia im length, and is linear, with 4—5 spines at the anterior margin. The metacarpus is longer and narrower, linear, with two pairs of spines on the anterior, and a simple hair at the posterior margin; at each of the lower corners there is a long, straight spine. The dactylus is very long, nearly straight, sharp-poited, not pedunculated, only a little shorter than the metacarpus (19: 23). The sith pair [Pl]. I, fig. 16] are longer than the fifth but of the same structure. The femur is longer than broad (29: 23), and carries a spine at the lower anterior corner. The metacarpus is quite as long as the femur, with four pairs of spines along the anterior margin, the last pair at the lower corner, two short spines at the hmder margin, and a longer one at the lower hinder corner. The dactylus is only a little shorter than the metacarpus [11: 14], straight, sharp. The seventh pair [Pl]. I, fig. 17] are about a fifth shorter than the sixth; the femur is broad, laminar, posteriorly produced downwards, the projection reaching nearly to the middle of the tibia; the hinder margin is curved, smooth; the anterior margin is feebly curved, nearly straight. The genu is short; the tibia of the same form as in the two preceding pairs, but carrying only two spines at the lower corners. The carpus is of the length of the tibia, with three or four spines along the an- terior margin and two on the posterior. The metacarpus is longer and narrower, but not equalling the femur in length; it carries four single spines along the anterior margin and one on the posterior. At the lower, hinder corner there are two straight spines. The dactylus is straight, long, sharp, but does not fully equal two thirds of the length of the metacarpus (15: 24). The pleon. The segments are large, equal in length, each as long as the sixth pereional segment. The flanks of the segments reach tole- rably deep, the under margin is rounded; they end posteriorly in a not very sharp angle. The pleon equals the first five pereional segments together in length. AMPHIPODA SYNOPIDEA. 13 The pleopoda (PI. 1, fig. 19]. The peduncles are elliptical, longer than the flagella; the number of articuli in the outer flagellum of the first pair is 10, in the inner flagellum 9. The ciliw of the flagella are pedunculated, long, plumose ; the peduncular part long, but shorter than the rest [Pl. I, fig. 20]. The urus {Pl. I, fig. 21]. The first segment is only a little longer than the second (5: 4); the last is nearly as long as the second. The urus is as long as the first three pereional segments. ‘The surface is quite smooth. The first pair of uropoda. The peduncle is linear, reaching to the posterior margin of the last ural segment. The rami are unequal, the inner much the longest, both ending with a strong movable claw-like spine. The outer ramus is shorter than the peduncle, finely serrated along the inner margin. The inner ramus is longer than the peduncle, the inner margin Asante carrying only one short spine at the middle and two very small at the lower corner, at the base of the great claw- like spine. The second pair. The peduncle does not reach to the posterior margin of the last segment; the rami are unequal in length, the inner the longest, both ending with Aa feebly curved spines, two in each. Both rami are smooth on the outer margins and finely serrated along the inner. The third pair. The peduncle is very short, broader below; the rami are unequal in length, the outer the longest. The outer ramus is two-jointed, the terminal joint equals a third of the length of the basal joint. The outer margins of both rami are smooth, the lower parts of the inner margins carry four simple hairs in the outer ramus, three in the inner one; at the lower end of the terminal joint of the outer ramus there are two minute spines. The lower end of the inner ramus carries also two minute spines and between them two long, strong hairs. The telson is very large, triangular, obliquely truncated behind, divided beyond the middle by a longitudinal fissure. At the lower ends there are some minute spines. The telson is longer than the peduncle of the last pair of uropoda, almost as long as the last two ural segments together. Colour. Ultramarine (Dana), hyaline. Length. 5—6 m.m. Hab. The tropical parts of the Atlantic. (S.M. U.M. CB.) 14 Cart Bova.uius, 2. Synopia caraibica. N. sp. (PI. II, fig. 30.) Diagn. Caput triangulare, longitudine Jatitudinem superans. Oculy parvi supplementarii, singuli, supra bases antennarum primi paris siti. Antenne primi paris quam pereion multo breviores, flagello valde setoso. Flagellum secundarium longitudine articulum primum flagelli (veri) superans. Segmentum primum pere?? secundum longitudine equans, sextum et septi- mum sequalia. Femora parium quinti, sexti et septimi pedwm pere? clongato-ovata. Pedes quinti paris longissimi, sequentes longitudine decrescentes. Pedunculi pedum plet ovati. Segmentum primum wr? secundo duplo longius. Telson ovatum, leviter fissum. The head is triangular, longer than broad. A small secondary eye on each side of the head, at the base of the first pair of antenne. The jirst pair of antenne are much shorter than the pereion, the flagellum is richly provided with hairs along its whole length. The se- condary flagellum is longer than the first joint of the true flagellum. The first segment of the pereion equals the second in length; the sixth is as long as the seventh. The femora of the fifth, sixth, and seventh pairs of pereiopoda are elongate-ovate, almost pear-shaped. The fifth pair are the longest, the following decreasing. The peduncles of the pleopoda are egg-shaped. The first segment of the wrus is twice as long as the second. The telson is ovate, only a little bifid. The only specimen of this animal that I got was very damaged, being taken from the stomach of an Exocoetus. It seems to be closely allied to §S. ultramarina, but is distinguished from it by comparatively good characteristics, as the setose flagellum of the first pair of antenna, the form ef the femora of the last three pairs of pereiopoda, especially of the last, and the form of the telson. The body is arched, but not as much as in 8. ultramarina. The head is proportionally much larger than in the preceding species, more obtuse; thé excavation for the insertion of the first pair AMPHIPODA SYNOPIDEA. 15 of antennz is much deeper. The head is fully as long as the first four pereional segments. The large median eye is surrounded by 20 ocelli in an unbroken circle. The secondary eyes are separated from the median one by a longer distance than in the other species. The first joint of the first pair of antenne is almost globular, the second narrow, linear, scarcely half as long as the first, the third a little longer. The flagellum consists of five joints, the first much the longest, all richly provided with long hairs. The secondary flagellum is two-jointed. The second pair of antenne were broken off. The pereion. The first four segments are equal, the last three a little longer, equal. The epimerals of the first and second segments are deeper than long; the following could not be examined. The pereiopoda, as far as it could be ascertained, are very similar to those of S. ultramarina, differing only in the form of the femora of the last three pairs, and in the length of the fifth pair. The pleon. The first segment is a little longer than the second, the pleon is exactly as long as the pereion. The pleopoda. The peduncles are shorter than the flagella. The urus is as long as the first four pereional segments. The last segment is longer than the second. The first pair of wropoda reach almost to the apex of the last pair. The telson is a little longer than the peduncle of the last pair of uropoda, equalling the last ural segment in length. The fissure is searcely a third of the length of the telson. Colour. White, with a few red spots at the lower ends of the pereional segments. Length. 5 m.m. Fab. The Caribbean Sea. (S. M.] One specimen in the stomach of a small EHxocoetus, off the coast of Venezuela at the Long. of the Island of Margarita. 16 Cart Bova.uius, 3. Synopia Schéeleana. N. sp. (Pl. II, fig. 22—29.) Deriv. The name in honor of Captain George von Schéele, the zealous collector of pelagic animals for the University of Upsala. Diagn. Caput triangulare, longitudine latitudinem equans. Oculi parvi supplementarii, singuli, supra bases antennarum primi paris siti, Antenne primi paris quam pereion longiores; flagellum secundarium longi- tudine articulum primum flagelli (veri) haud squans. Seementum primum pere/’ secundum longitudine zquans; sextum septimo bre- vius, septinum omnium longissimum. Femora paris quinti pedwm pereti ovata, femora paris sexti circularia. Peduneuli pedwm plet cylindrici. Segmentum primum 77 secundo ter longius. Rami ultimi paris pedem wri inzequales, margine toto interno setis instructo. Telson latum, ovatum, in apice rotundatum. The head is triangular, as broad as long. A small secondary eye on each side of the head, at the base of the first pair of antenne. The first pair of antenne are longer than the pereion; the secon- dary flagellum shorter than the first joint of the true flagellum. The first pereional segment is as long as the second; the sixth is shorter than the seventh, which is the longest. : The femora of the fifth pair of pereiopoda are ovate, those of the sixth pair circular. The peduncles of the pleopoda are cylindrical. The first ural segment is three times longer than the second. The rami of the last pair of wropoda are unequal in length, fringed with hairs along the whole length of the inner margins. The telson is broad, ovate, rounded at the ends. Synopia Schéeleana is intermediate between S. ultramarina and S. gracilis, but is perhaps more allied to the last. It differs from it in the following characteristics: the supplementary eyes, the short se- condary flagellum of the first pair of antenna, the circular form of the femur of the sixth pair of pereiopoda, the length of the same pair in comparison with the seventh; the equal length of the rami of the last pair of uropoda. The differences from 8. ultramarina will be men- tioned below. AMPHIPODA SYNOPIDEA. ey The body is not very arched, almost straight. The head is triangular seen from above, but nearly rectangular seen from the side, a little shorter than the first four pereional seg- ments. The excavation for the insertion of the antenne is very large, deeper than half the depth of the head. The median eye is very broad, not circular; the number of peri- pherical ocelli is about thirty, those of the hinder margin are indistinct. The small secondary eyes are situated very close to the median eye. The first pair of antenne (PI. II, fig. 23] reach quite to the anterior margin of the second pleonal segment. The last joint of the peduncle is scarcely as long as a third of the second. The flagellum consists of 16 joints, the first much the longest, as long as the four following ones to- gether, beset with long hairs; the following are totally smooth, except the last, which carries a long terminal hair. The secondary flagellum is two-jointed, shorter than the first joint of the true flagellum. The second pair of antenne [P1. Il, fig. 24] are similar in struc- ture to those of S. ultramarina, but the articuli of the flagellum are longer and more setose. The pereion. The fifth and sixth segments are equal, the seventh the longest, as long as the first two together. The epimerals [P1. II, fig. 22] resemble very closely those of S. ultramarina. The first pair of pereiopoda [Pl. HW, fig. 25] differ from the same pair in §S. ultramarina only in very unimportant details, as the carpus being proportionally longer, the plumose hairs also longer, as long as the breadth of the joint, and the dactylus shorter, equalling only two thirds of the length of the metacarpus. The second pair [Pl. Ul, fig. 26] are of the same form as in BS. ultramarina, the bristles of the carpus and metacarpus are a little longer and stronger. The third pair (PI. II, fig. 27]. The femur is shorter than the epi- meral is deep. The tibia is longer than the carpus; the tibia and car- pus together are longer than the femur. The anterior margin of the tibia is fringed with minute hairs. The fourth pair [Pl. Il, fig. 28]. The carpus is almost twice as long as broad; both tibia and carpus are filled with a glandular mass, a little of which is to be seen also in the metacarpus. The metacarpus is half as long as the carpus, the hinder margin fringed with 10—12 very long, plumose hairs, longer than the joint itself. Nova Acta Reg. Soc. Sc. Ups. Ser. II. 3 18 CarL Bova..ius, The fifth to seventh pairs are like those of S. ultramarina, dif- fering only in the form of the femora of the fifth and sixth pairs. The pleon is longer than the pereion. The peduncles of the pleopoda are cylindrical, shorter than the flagella. The uwrus. The first segment is three times longer than the se- cond, the third is almost twice longer than the same. The first pair of uropoda (Pl. Il, fig. 29]. The outer ramus is finely ciliated along the inner margin, with a minute spine in the middle. The second pair. The peduncle reaches beyond the posterior mar- gin of the last segment. The outer ramus is totally smooth along both margins; the inner ramus finely ciliated, with two short spmes along the inner margin. The third pair. The rami are unequal in length, the outer the longest, two-jointed; the outer margins of both rami are smooth, the inner fringed with hairs along their whole length. The telson is a little longer than the last ural segment, broadly ovate, bifid, with rounded ends, the fissure scarcely equalling half the leneth of the telson. Colour. Hyaline. Length. 4—6 m.m. Hab. The tropical parts of the Atlantic (U.M. 8.M.). Some twenty miles East off Barbadoes (D.M., C.B.). 4. Synopia gracilis. DANA, 1852. (Pl. II, fig. 31—355, copied from Dana). Syn. 1852. Synopia gracilis. DANA. United States Exploring Expedition. Crustacea. vol. 2, p. 998, pl. 68, fiz: 7 a—e. , Fol! Diagn. Caput triangulare, longitudine latitudinem sequans. Oculi supplementarii desunt. Antenne primi paris quam pereion multo longiores; flagellum secundarium longitudine articulum primum flagelli (veri) eequans. Segmentum primum perce? secundo brevius, segmentum sextum et septimum eequalia. Kemora parium quinti et sexti pedwm perei non rotundata, infra truncata. Pedes septimi paris pedibus sexti paris longitudine sequales. AMPHIPODA SYNOPIDEBA. 19 Peduneuli pedum plet in apice truncati. Segmentum primum wré secundo plus quam duplo longius. Rami ultimi paris pedwm wri longitudine squales. Telson obsoletum. The head is triangular, as broad as long. Secondary eyes are wanting. The first pair of antennw are much longer than the pereion; the secondary flagellum equals the length of the first joint of the true flagellum. The first pereional segment is shorter than the second; the sixth is as long as the seventh. The femora of the fifth and sixth pairs of peresopoda are not rounded, but truncated below. The seventh pair equal the length of the sixth. The peduncles of the pleopoda are truncated below. The first wral segment is more than twice longer than the second. The rami of the last pair of wropoda are equal in length. Telson obsolete. Dana proposed the above quoted name for the animal, but he thought that it might possibly prove to be the male of S. ultramarina. As I have got males among the specimens, which | have identified with Da- nas S. ultramarina, I must retain the name of Dana, allowing that the animals are closely allied. »The body is more slender than in S. ultramarina, and has no convexity along the back.» »The excavation in the lower part of the head, from which the antenne proceed is very large, being as broad as the part af the head immediately above.» »The superior antennz are sparingly shorter than the body; fla- vellum of the inferior pair scabrous.» Colour. »More or less. entirely ultramarine.» »The blue colour was deepest along the venter. The four anterior legs and the bases of the superior antenne had the same rich blue colour.» Length, 6 m.m. Hab. The Atlantic: »Lat. 8°--12° S. and Long. 11°—14°15" W:; also Lat. 4°—7° S. and Long. 21°—25° W.» 20 Cart Bovau.ius, id 5. Synopia angustifrons. DANA, 1852. (Pl. I, fig. 836—39, copied from Dana). Syn. 1852. Synopia angustifrons. DANA. os United States Exploring Expedi- tion. Crustacea. vol. 2, p. 998, pl. 68, fig. 8 a—d. Fol. 1862. * " " Spence Bate. Catalogue of the specimens of Amphipodous Crustacea in of the collection of the British Museum. p. 342, pl. 54, fig. 2. Diagn. Caput angustum, triangulare, longius quam latius. Oculi supplementarii desunt. Antenne primi paris quam pereion multo breviores; flagellum secundarium longitudine articulum primum flagelli (veri) superans. Segmentum primum pere?? secundo brevius, segmentum sextum et septimum eequalia. Femora paris quinti pedwm perei’ angusta, rectangularia, femora paris sexti duplo latiora, infra truncata; pedes septimi paris pedibus sexti breviores. Pedunculi pedwm plet infra lati, truncati. Segmentum primum 777 secundo paulo longius. The head is narrow, triangular, longer than broad. Secondary eyes are wanting. The first pair of antenne are much shorter than the pereion; the secondary flagellum is longer than the first joint of the true flagellum. The first pereional segment is shorter than the second; the sixth is as long as the seventh. The femora of the fifth pair of pereiopoda are narrow, rectangu- lar, those of the sixth pair twice as broad, truncated below; the seventh pair are shorter than the sixth. The peduncles of the pleopoda are broad at the lower ends, truncate. The first wral segment is only a little longer than the second. The sides of the head »converging forward at an angle of 40°—50%. »The number of ocelli is between 40 and 50.» The first pair of antenne (Pl. Il, fig. 38] reach to the anterior margin of the fifth pereional segment, the true »flagellum is five-jointed», the secondary flagellum »three-jointed». The second pair of antenne reach beyond the anterior margin of the last pleonal segment. »The flagellum is ten-jointed, joints slender, cylindrical». AMPHIPODA SYNOPIDEA. yA | The second pair of pereiopoda [Pl. H, fig. 39] are »slender, the joints cylindrical». The femur of the seventh pair »is similar to that of S. ultramarinap. Colour. »Intense blue, with a barely perceptible tinge of red.» Length. 4 m.m. Hab. The Pacific »Lat. 18° S. and Long. 122° W.» 6. Synopia orientalis. R. KOSSMANN, 1880. Syn. ISSO. Synopia orientalis. R. KOSSMANN. Zool. Ergebnisse e. im Auftr. der K. Acad, der Wiss. zu Berlin ausgef. Reise in die Kiistengebiete des Rothen Meeres. vol. 2p. Lod, pl. 15; fie. 11—13. Fol: The head is not produced anteriorly over the bases of the an- tenne, vertically truncated. The median eye is large occupying the whole length of the head. Both pairs of antenne are longer than the body. The first joint of the flagellum of the first pair is very long. The secondary flagellum is three-(2)jointed. The second pair of antenne are longer than the first. The tibia and carpus of the third pair of pereiopoda are stronger and stouter than those of S. ultramarina. The dactylus is pedunculated. The tibia of the fourth pair is shorter than half the carpus. The dac- tylus is long, not pedunculated. »The other characters agree with those of Synopia ultramarina, Dana.» Length, 3 m.m. Hab. The Red Sea. 22 Syn. Diagn. Cart Bova.uius, The second Family. TRISCHIZOSTOMATIDE. G. O. SARS. 1860. Prostomate. A. BOECK. Forhandl. ved de Skandivaviske Natur- forskeres 8:de Mode. p. 637. 1865. Trischizostomatina. W. LILLJEBORG. »Bidrag till kannedomen om under- familjen Lysianissina inom underord- ningen Amphipoda bland kraftdjuren». p. 9. in Upsala Universitets Arsskrift 1865. Matematik och Naturvetenskap. »On the Lysianassa magellanica», ete. p. 17, in Nova Acta Reg. Soc. Se. Upsaliensis. Ser. HI, vol. VI. 1IS7O. = Prostomata. A. BOECK. »Crustacea amphipoda borealia et are- phip tica». p. LO. in Christ. Vidensk. Selsk. Forhandlinger for 1870. 1872. x os De skandinaviske og arktiske Amphi- poder. p. 95. 4:to. 1882. Trischizostomida. G. O. SARS. »Oversigt af Norges Crustaceer», ete. I. in Christ. Vidensk. Selsk. Forhandlin- ger 1882, N:o 18. p. 20. The head triangular, not tumid. The eyes large, occupying the sides of the head, distinetly faceted. The mandibles styliform, with a strong three-jointed palp. The mazillipeds coalesced along the middle, forming a gouge-like operculum for the mouth-organs, carrying a four-jointed palp. The antenna are fixed on the under-side of the head. The second pair of antennze like those of the Gammarids. The seventh pair of peretopoda not transformed. The wropoda like those of the Hyperids. The telson simple. Only one genus Trischizostoma, A. Borck. The young ones of Trischizostoma Raschii show an interesting feature pointing to their relationship with the preceding family, in the exterior ramus of the last pair of uropoda being bi-articulate and the telson cleft or rather in- cised to less than a fifth of its length. These characteristics are totally changed in the adult animal. In the large epimerals of the second to fourth pereional segments the animals belonging to. this family show another resemblance to the Synopide, a feature which reappeares in the family Hyperiopside, but in a lower degree. AMPHIPODA SYNOPIDEA. 23 Gen. 1. Trisehizostoma. A. BOECK, 1860. Syn. 1860. Trischizostoma. A. BOECK. —— Forhandlinger ved de Skand. Na- turforskeres 8:de Mode. p. 637. 1865. 5 W. Linusenora. »Bidrag till kannedomen om un- derfamiljen Lysianassina inom underordningen Amphipoda bland kraftdjuren». p. 9, in Upsala Uni- versitets Arsskrift, 1865. Mate- matik och Naturvetenskap. BS * “ r »On the Lysianassa magellanica», etc. p. 17, in Nova Acta Reg. Soc. Se. Upsaliensis, Ser. III, vol. VI. 1870. a ‘5 A. Borck »Crustacea borealia et arctica. p- 10. in Christ. Videnskabs Selsk. Forhandlinger for 1870. 1872. 53 én —— De Skandinaviske og Arktiske Amphipoder. p. 96. 4:to. Diagn. Corpus latum, non compressum. Caput latum, triangulatum, ante in rostrum latum, crassum, in apice rotunda- tum, productum. Oculi grandes, in medio capitis non confluentes, ocellis magnis. Antenne primi paris flagello multi-articulato instructee, articulum primum fla- gelli crassum, elongatum. Pedes perevi primi paris metacarpo permagno, inflato, semicirculari; dactylo in angulo inferiore posteriore affixo. Pedes pereii quarti paris tibia elongata, valde dilatata. Pedes trium parium ultimorum dactylis modicis, robustis. Pedes uri ultimi paris ramis lanceolatis, integris. Telson magnum. The body is broad, not very compressed. The head is broad, triangular anteriorly produced into a_ broad, thick rostrum, rounded at the tip. The eyes are large, not coalesced in the middle of the head, with distinct large ocelli. The first pair of antenne with a multi-articulate flagellum, the first joint of the flagellum thick and long. The first pair of perevopoda have a very large, tumid, semicircular metacarpus, the dactylus is articulated against the hinder lower corner of the metacarpus. The fourth pair with the tibia very broad and long. The last three pairs with robust, but not very long dactyli. The last pair of wropoda with the exterior rami lanceolate, not bi-articulate. The telson is large. Only one species is hitherto known, 24 Car Bova utius, Trischizostoma Raschii. A. BOECK, 1860. Syn. 1860. Trischizostoma Raschii. A. BOECK. Forhandl., ved de Skandinaviske Natur- forskeres 8:de Méde. p. 637. 1870. a ee _ »Crustacea amphipoda borealia et arctica», p. 11. in Christ. Vidensk. Selsk. For- handlinger for 1870. 1872. 3 3 De skandinaviske og arktiske Amphipo- der. p. 97. A4:to. Diagn. Caput cum rostro segmento primo pereil brevius. Antenne primi paris flagello decem-articulato, articulo primo sequentibus lon- gitudine sequante. Flagellum secundarium tri-articulatum. Genu paris seeundi peda pereit perlongum, longitudine carpum superans ; dactylo minimo. Tibia paris quarti longitudinem femoris sequans. Epimera segmentorum secundi, tertii et quarti permagna, epimerum segmenti secundi maximum, triangulatum. Pedes wi secundi paris apicem ultimi paris attingentes. Telson rotundatum, pedunculo pedum uri ultimi paris longius. The head with the rostrum shorter than the first pereional segment. The flagellum of the first pair of antenne ten-jointed, the first joint as long as the following together. The secondary flagellum is three-jointed. The genu of the second pair of pereiopoda is very long, longer than the carpus; the dactylus is very small. The tibia of the fourth pair equals the length of the femur. The epimerals of the second, third, and fourth segments are very large, that of the second segment is the largest, triangular. The second pair of uropoda reach to the end of the third pair. The telson is rounded, longer than the peduncle of the last pair of uropoda. The description of Borck is not quite accurate; it seems that he has taken some characteristics from the adult animal and others from very young ones; the drawings given by him do not always agree with his description; on this account it seems convenient to give here also figures of some details of a younger specimen for comparison with the same organs in the adult animal. The specimens described here were taken by me at »Tjétté», Northern Norway, from a depth of 80 fathoms July 1871, and in »Hardanger fjord» south-western coast of Norway, July 1880, AMPHIPODA SYNOPIDEA. 25 The habitus of the animal resembles a Lysianassa, the dorsal side of the body being broad and even, without keel; the surface of the body is smooth and hard as if polished. The adult female. The head is much deeper than the pereion, broad, smooth; the rostrum is very broad at the base, slightly tapering towards the end, the apex broadly rounded. The head with the rostrum is as long as deep, and a little shorter than the first pereional segment. The insertion for the antenne on the under-side of the head, at the base of the rostrum, pointing to the case of the Oxycephalide. The eyes occupy almost the whole sides of the head, separated from one another only by a very narrow strip of the front; they con- sist each of large ocelli, ranged in 18 longitudinal rows, 9 in the upper- most row and 8 in the undermost one, in all about 100 ocelli in each eye. The first pair of antenne [PIl. III, fig. 42] are a third longer than the head. The first joint of the peduncle is very thick and long, the second very short, the third twice as long as the second. The flagellum is 10-jointed; the first joint is as thick at the base as the last peduncular joint, and is almost as long as all the following joints together (13: 15), smooth, tapering anteriorly. The two following joints are short, equal, a little narrower than the apex of the first joint; the last seven joints are shorter and narrower, tapering towards the end, without hairs or bristles. The secondary flagellum is three-jointed, almost as long as the first joint of the ordinary flagellum; its first joint is very long and thick, the two terminal very minute, carrying some minute hairs. The second pair of antenne [Pl. IU, fig. 43] are much longer than the first pair, reaching, if bent backwards, beyond the anterior margin of the fourth pereional segment. The first joint of the peduncle is stout and thick, projecting downwards into a short, round process, forming the opening of a cavity in the joint; I suppose that the organ can be interpreted either as an auditory cavity, as the lower, circular surface of the process seems to be closed by a thin membrane, or as a secret- ory gland. The dissection of the organ gives more probability to the latter supposition, because the process is filled with a granular mass and only a few very minute hairs are to be seen at the bottom of the joint. The second and third joints are very short, but broad; the fourth is the longest, broader than the fifth, carrying a single Nova Acta Reg. Soc. Sc. Ups. Ser. II. 4 26 Cart Bova.uius, plumose hair at the lower hinder corner. The fifth jot carries some minute hairs along the anterior margin, and at the lower end. The flagellum is a third longer than the peduncle, the first joint is the longest, about half as long as the last jot of the peduncle, the follo- wing are short, tapering towards the end. The mouth-organs are transformed into a projecting tube, forming a powerful boring and sucking instrument. The labrum [Pl. II, fig. 44] forms a long, triangular, open channel, bifid at the lower end, with sharp, tooth-shaped points, exca- vated at the base to afford place for the mandibular palps. The mandibles [Pl. Il, fig. 45] consist of a broad, strong basal portion, projecting into a long, single, sharp-pointed, styliform process; at the base of the process it carries a large, stout palp; the first joint of the palp is very short but broad; the second very long, elongate- ovate, with an oblique row of long, simple hairs from the middle to the upper end; the third joint is a little shorter than the second, bor- dered by long hairs along the inner margin. The first pair of maaille {Pl. III, fig. 46] have the outer lamina reduced, the inner elongate, with four strong teeth at the apex. The second pair of maaille (Pl. HI, fig. 47] with both lamine elongate, narrow, carrying minute teeth at the ends. The mazillipeds [Pl]. III, fig. 48] are coalesced into a gouge-like channel, forming together with the labrum the walls of the tube; the two first joints of the right maxilliped are coalesced with the corre- sponding joints of the left one, the inner lamine are very narrow, concealed by the outer, which are large, hollowed, placed close to one another. The palp is four-jointed, as usual, the first joint short, the second, twice longer, equalling the third, the fourth is the longest. The second and third carry long hairs at the exterior ends. The pereion. The first segment is long, the longest of all, equal- ling the last two ones together in length, the second to fifth segments are equal, the hinder corners feebly rounded. At tiie dorsal side of the sixth and seventh segments there is a slight ovate excavation. The surface is hard and smooth, white as ivory. The segments are a little convex longitudinally, distinctly separated from one another; the first is somewhat higher than the others. The epimerals [Pl. III, fig. 41] are well developed, that of the first segment is long but not very deep, triangular, partly concealed by the following, which is enormous in size, triangular, with the upper AMPHIPODA SYNOPIDEA. 27 corner truncated, as long as the first two pereional segments. The epimeral of the third segment is as long as the segment, but twice as deep, rounded at the anterior margin, straight at the hinder. That of the fourth segment is fully as long as the segment, the anterior margin rounded, the inferior straight, the lower hinder corner truncate, and the hinder margin deeply excavated. The epimeral of the fifth segment is longer than the segment and longer than deep, with ob- tusely rounded corners. The epimerals of the sixth and seventh seg- ments are smaller, not so deep as the preceding, scarcely longer than the corresponding segments, with feebly rounded corners. The branchial sacks are very large, thin, showing very broad white crests or bands crossing each other at acute angles. They are fixed at the bases of the second to seventh pairs of pereiopoda. The ovitectrices [Pl. Il], fig. 49] are shorter than the branchial sacks, lanceolate, four on each side. The first pair of pereiopoda [PI]. Ul, fig. 50) are enormously deve- loped, and characterize the animal at once. The femur is long and narrow, slightly bent at both ends; the genw is tolerably long and stout; the tibia is shorter; the carpus a little longer, but transformed, and turned round backwards, pressed against the metacarpus with the whole length of the joint, thus turning round the metacarpus so that the original anterior corner seems to be the posterior. The metacarpus 1s elobularly inflated, bordered by sharp, recurved teeth along the under margin, against which the dactylus impinges; the anterior corner 1s pro- vided with five tooth-shaped tubercles and two movable, strong bristles. The dactylus articulates against the apparently hinder corner of the me- tacarpus, it is quite as long as the underside of the metacarpus, feebly curved, without teeth or serrations. The hand thus forms a most po- werful instrument for holding fast the animal to the body of its host, the animal probably living as ecto-parasite on sharks, and other larger fishes, principally from greater depths. The second pair [Pl. Il, fig. 51]. The femur is long, smooth, broader at the lower end; the genu is of an unusual length, a little shorter than the femur and longer than the carpus; the tebia equals half the length of the femur; the carpus is longer, richly beset with hairs; the metacarpus is short, broadly triangular, surrounded with hairs. The very small dactylusis articulated at the middle of the lower margin of the underside of the metacarpus, not as usual at the anterior corner. The part of the margin, against which the dactylus impinges, is denticulated, 28 Cart Bova.utus, with rounded, minute teeth, and provided with stout, straight bristles of an- other kind than those bordering the rest of the metacarpus [PI. III, fig. 52]. The third pair [Pl. II, fig. 53]. The femur is tolerably broad; the genu short; the t2bza very long, broad, with some short spines at the hinder lower corner. The carpus is ovate, short, scarcely half as long as the femur. The metacarpus is long, as long as the tibia, narrow, finely serrated along the hinder margin. The dactylus equals a third of the length of the metacarpus; it is not very curved, finely serrated along the hinder margin. The fourth pair (PI. Ill, fig. 54). The femur is longer than broad, smooth; the genu is short; the teébca is long and unusually broad, broader than half its length (9: 15), with some minute spines along the hinder margin, pointing to the state in Hyperiopsis; the tibia equals the length of the femur. The carpus is ovate, half as long as the tibia. The metacarpus and dactylus are similar to those of the preceding pair, the dactylus only a little longer [Pl. III, fig. 55]. The fifth pair (Pl. II, fig. 56}. The femur is broad, laminar, the hinder part deeply produced downwards, the hinder margin straight; the genu small; the tebia broad, provided with minute spines along the anterior and posterior margins; the carpus is only a little shorter than the tibia, serrated at the anterior margin, with two small spines. The metacarpus is as long as the carpus; the dactylus longer than half the metacarpus, both serrated along the anterior margins. The sixth pair [Pl. Il, fig. 57]. The femur is broad, laminar, the hinder part not so deeply produced as in the preceding pair; the an- terior and posterior margins rounded; at the lower anterior corner there are some strong bristles. The téb¢a is narrower than in the preceding pair, with the same armature. The carpus is as long as the tibia; the metacarpus a little shorter; the dactylus half as long as the preced- ing joint; all three joints serrated along the anterior margins. The seventh pair [Pl. Ill, fig. 58] are a little longer than the fifth and sixth pairs; the femur has the anterior margin straight; the follow- ing joints are similar to those of the sixth pair. The pleon. The segments are large, subequal, tolerably deep; the flanks of the segments are rounded, with a slight angulation inferiorly. The pleon is as long as the first four segments of the pereion; the sur- face is smooth and hard as in the pereion. The pleopoda [Pl. UI, fig. 59] consist of a thick peduncle and two long, articulated flagella, bordered with long, plumose hairs. The AMPHIPODA SYNOPIDEA. 29 flagella are longer than the peduncles. The flagellum of the first pair consists 17 joints. The urus [Pl. III, fig. 60] is shorter than the first two pereional segments, and also shorter than the first two pleonal segments. At the dorsal side of the first segments there is a deep excavation for the re- ception of the hinder margin of the last pleonal segment, when the body is stretched out. The second and third segments are free, not coa- lesced, the third longer than the second. The jirst pair of uropoda reach to the ends of the peduncles of the last pair; the rami are longer than the peduncle; the outer ramus is slightly serrated along the outer margin; the inner ramus smooth, a little longer; both broadly lanceolate. The second pair reach as far as the third pair; the rami are nar- rower and more pointed than in the preceding pair, smooth, a little longer than the peduncle. ~ The third pair are nearly as long as the two last ural segments, the rami are more than twice longer than the peduncle, lanceolate, smooth. The telson is almost circular, longer than the peduncle of the last pair, with the margins smooth. Length 22 m.m. The young male. (Pl. Ill, fig. 61—67). The specimens examined were probably just out from the incuba- tory pouch of the mother; they present some interesting differences, which will be shortly mentioned below. Some of these characteristics point decidedly to the family Synopide. The head is longer than the first pereional segment. The eyes are distinctly faceted, but without the brown pigment. The first pair of antenne [PI. III, fig. 62] are nearly twice as long as the head, the flagellum four-jointed, the secondary flagellum two-jointed. The second pair of antenne [PI. III, fig. 63] have only fourjoints in the flagellum, the first joint very long. The mouth-organs are very similar to those of the adult animal, but the palp of the mandibles wants hairs, and the teeth at the ends of the maxille are but feebly developed, the lamine and the palp of 30 Cart Bova ius, the maxillipeds are not ciliated, quite smooth; the inner laminz are more distinct than in the adult animal. The pereion. The first segment is shorter than the sixth and se- venth together. The surface of the pereion shows. the insertion of the muscles, and is a little granular. The epimerals (Pl. IH, fig. 61] are smaller than in the adult animal. The first pair of pereiopoda (PI. Ill, fig. 64] are proportionally larger, and the carpus not transformed as in the adult animal; the meta- carpus with the anterior angle directed forwards as usual, and thus the dactylus articulating in its ordinary place; the lower inargin of the meta- carpus shows only a few very minute teeth; the dactylus is shorter than the lower margin of the metacarpus. The second pair [Pl. II, fig. 65]. The genu is shorter than half the femur; the metacarpus is nearly ovate, and the dactylus pro- portionally longer. The third and fourth pairs (Pl. IIL, fig. 66] have the tibia shorter and not so much dilated as in the adult animal. The fifth, siath, and seventh pairs have the femora very narrow and the following joints smooth, not serrated. The pleon is longer than the first four percional segments. The pleopoda carry pointed flagella; the peduncles are very long. The urus [Pl]. Hl, fig. 67] is as long as the first two pereional segments, and nearly as long as the first two pleonal ones. The ex- cavation at the dorsal side of the first segment is very distinct; the first segment is as long as the two following together. The third segment is only a little longer than the second. The first pair of wropoda with the rami narrower, without serra- tions; at the lower end of the outer ramus there is a small notch, indicat- ing an earlier division or articulation of the ramus. The same occurs in the second pair. The third pair do not reach beyond the tips of the second pair, the rami are scarcely twice longer than the peduncle. The outer ramus consists of two joints, as in Synopia, the terminal joint equals a third of the length of the basal joint. The inner ramus is undivided, smooth. The telson is broad, not rounded, deeply excavated, nearly bifid at the middle of the posterior margin. Length. 5 m.m. Colour. White as ivory; the eyes dark brown, AMPHIPODA SYNOPIDEA. 31 Hab. The Arctic Sea, the North Atlantic. The animal was found for the first time at »Havbroen»y, a bank, 150—300 fathoms deep, some twenty miles off the west coast of Norway, by Professor Rascn, of the Christiania University; later at »Throndhiemsfjord», more to the north on the same coast, by Conservator Storm. ‘This specimen was parasite on a shark. In the year 1880 I found some specimens in »Hardangerfjord», at a depth of 250 fathoms, parasites on, or in com- pany with, an Asterias. Some years before I had got about twenty young specimens at »Tjétté», on the west coast of Norway, some twenty miles south of the polar circle. A very young one was also taken by A. Borck in »Christianiafjord», the south coast of Norway, at a depth of 60 fathoms. I am also informed that some specimens of the animal were captured at the west coast of Novaja-Zemlja by Captain Collin. (S.M., U.M., D.M., N.M., CB.). The third family. WYPERIOPSID#. Diagn. The head large, globular, tumid. The eyes large, filling the sides of the head. The mandibles with a three-jointed palp. The maxillipeds? The first pair of antenne are fixed at the lower anterior corner of the head; the second pair are fixed on the under-side of the head; they are few-jointed, not angulated. The seventh pair of perevopoda transformed. The two first pairs of wropoda are two-jointed, not bi-ramous, the last pair bi- ramous. The f¢el/son is simple, very minute. Genus 1. Hyperiopsis. G. O. SARS, 1885. Syn. 1885. Hyperiopsis. G. O. SARS. The Norwegian North Atlantic Expedition 1876 -——1878. Zoology. Crustacea, I, p. 231. Fol. Diagn. Carpus latum. Caput globulare, tumidum. Oculi grandes, imperfecti. , Antenne primi paris flagello multi-articulato, articulo primo valde elongato, setoso, Pedes pereii primi et secundi paris simplices non subcheliformes, pedes tertii et quarti paris tibiis elongatis lamellatis, instructi ; pedes pereii paris ultimi transformati, filiformes. Pedes wri ultimi paris ramis lanceolatis. Telson minimum. 32 Cart Bova..ius, The body is very broad. The head is globular, tumid. The eyes are large, but imperfectly developed. The first pair of antenne with a multi-articulate flagellum; the first joint of the flagellum very long, beset with long hairs. . The two first pairs of pereiopoda are simple, not subcheliform; the two succeeding pairs with the tibia very long, lamelliform; the last pair transformed, filiform. The last pair of wropoda with lanceolate rami. The telson is minute. Only one species is known. 1. Hyperiopsis Voeringii. G. O. SARS, 1885. (Pl. II, fig. 40, copied from G. O. Sars.) Syn. 1885. Hyperiopsis Voeringii/ G. O. SARS. The Norwegian North Atlantic Expe- dition 1876—1878. Zoology. Crusta- cea, I, p. 231. Fol. Diagn. Corpus leve. Caput margine anteriore arcuato, tuberculo parvo supra bases antennarum primi paris instructo. Antenne primi paris flagello XII—XII]-articulato, articulo primo sequentibus breviore. Flagellum secundarium quattuor-articulatum. Tibi parium tertii et quarti pedwm perei valde clongatee., dilatatee, remi- formes. Epimera segmentorum quattuor priorum magna, subsequalia. Rami paris ultimi pede wi pedunculo longitudine eequales. The body is smooth. The head with the anterior margin evenly arched, with a slight tubercular projection over the base of the first pair of antenne. The first pair of antenne with a 12—13-articulated flagellum; the first joint shorter than the following together. The secondary flagel- lum is four-jointed. The tibiae of the third and fourth pairs of pereiopoda are very elongate, dilated, oar-shaped. The epimerals of the first four pereional segments are large, subequal. The rami of the last pair of wropoda equal the length of the peduncle. AMPHIPODA SYNOPIDEA. 33 As I have not got any specimen at my disposal for examination, the above quoted characteristics are extracted from the description of Professor Sars (I. ¢c.); for further particulars I refer to his detailed de- scription, mentioning here only some few important facts. The eyes are without any trace of refractive elements or distinctly developed pigment. The secondary flagellum of the first pair of antenne is about as long as the first joint of the true flagellum; its first joint is the longest. The second pair of antenne are shorter and more slender than the first, the flagellum is shorter than the peduncle. The femora of the last three pairs of pereiopoda are slender, not lamelliform; the following part of the last pair is very elongate. The first two pairs of wropoda are long, slender, two-articulate. This is a very peculiar form of uropoda, not occurring, as far as I know, in the tribe of Amphipoda Hypertidea. Length. i mi.m. Hab. The North Atlantic. »One example of this remarkable Amphipod was taken, on the first cruise of the Expedition, off the Norwegian coast (Stat. 54)%) at a depth of 600 fathoms. Another (defective) specimen was subsequently extracted from the stomach of the remarkable deep-sea fish, Rhodich- thys regina, CotxerT, brought up at Stat. 297°), from a depth of 1280 iinomsy (G. O. Sars 1c. p. 233). 1) About Lat. 64°54’ North and Long, 3°50’ East from Greenwich. 2) About Lat. 71°50’ North and Long. 5°30’ East from Greenwich. or Nova Acta Reg. Soc. Sc. Ups. Ser. III. Fig. Fig. “~1 18. 19. no DO po i) ol COR wl he CS bo OU a. tXPLANATION OF THE PLATES. BL Synopia ultramarina. Dana. The animal seen from the side. ¢. ('8/,). One of the first pair of antenne. g. (3?/)). >» » » second pair of antenne. g. (3?/)). The secondary flagellum of the first pair of antenne. g. (°°/;). A piece of the labrum. 9. (98/,). The right mandible. (9/,). A piece of the surface of the molar tubercle of the mandible. (#6°/;). A bifid spine from the excavation of the mandible. (?5°/;). The right one of the first pair of maxille. (°8/)). The left one of the second pair of maxille. (°8/)). A spine from the same. (??°/;). The left maxilliped. (°§/,). One of the first pair of pereiopoda. (#8/,). » » » third » » » G 8/,). » » fourth » >» » (#8/,). » » fifth » » 2 (48/,). >. > pret yy » (#8/,). » seventh » » > (48/3). An ovitectrix from the fifth segment. (#8/,). One of the first pair of pleopoda. (#8/)). - A hair from the preceding. (75°/,). The urus. (48/,). PEALE Synopia Schéeleana. N. sp. ¢. The animal seen from the side. (18/,). One of the first pair of antenne. (3?/,). second » » . (39/1): first > > pereiopoda. (48/,). Fig. 26. One of the second pair of pereiopoda. (#8/)). » 27. » » » third >» » > (48/,). » 28. » » “» fourth » » : (48/,). * 29. The urus. (£5/,). Synopia caraibica. N. sp. ¢: Fig. 30. The head of the animal from the side. (18/;). Synopia gracilis. Dana. ‘iv, 31. The animal seen from the side. » 82. The head from above. > 383. One of the first pair of antenne. | copied from Dana. Soa >» » » » » > u ropoda. » 85. The last pair of » Synopia angustifrons. Dana. Fig. 36. The animal seen from the side. 2 » 37. The head from above. ra ; : . copied from Dana. » 38. One of the first pair of antenne. ! » 39. » » » second » » preiopoda. Hypertopsis Voeringii. G. O. Sars. 40. The animal seen from the side (copied from G, O. Sars). oe ee 168 Trischixostoma Raschit. A. Boeck. The adult female. Fig. 41. The animal seen from the side. (#/)). » 42. One of the first pair of antenne. (!?/)). >» » » second » » » (a) wae] the labrum, (22/5). » 45. The left mandible. (3?/,). » 46. One of the first pair of maxille. (3?/,). » AT. » » » second » » » Can): » 48. The maxillipeds. (3?/,). » 49. An oyitectrix from the fourth segment. (1?/,). 50. One of the first pair of pereiopoda. (1?/;). 21 51 >» » » second » » > (12/)). 52. The dactylus of the preceding. (%*/;). » 53. One of the third pair of pereiopoda. (1?/;). Cr Go or > Ot Ot Cl oa) D> = on nS One The One > of the fourth pair of pereiopoda. (1?/;). last joints of the preceding. (3°/}). of the fifth pair of pereiopoda. (1?/,). » » sixth >» » » (Ce 1): » » seventh » » » (2/7): » » first >» >» pleopoda. . aa ). urns. (¢/;,): The Young male. animal seen from the side. (11/4). of the first pair of antenne. (B27: » » second » » » (35/))- » » first >» » pereiopoda. (3579): » » second » » » COE > >= fourth > 9s » (39/1). urus. (42/4). fe pemeteeiilaame. -y . by “| VY, DOVAaAlLIIIS, AMpPMpsG RR eh ee iz hice. — sk : . ; z BN pe = ee EES L__+ =D Se <: SS tondyan } | teryren del T dl Se. Ups. Ser, IIT iB. 00. ' Nova Acta Reé —— » Nova. Acta Reg. S06, Sc.Ups. Der. LEE. iin Bovalhus, Amphiy ada synopide 5 b c } ‘oc mnt ec ; =f ' = pA.M Westergren del. Tath W. Schlachter, Stoc! y ru! t } , | eM ya i A WAN Hien iy Oe, uc ¥ We Ay +i 4 vel rs : we Reet: PT: OF rae ite