Umvor MAN UAL J ONCHOLOGY; STRUCTURAL AND SYSTEMATIC. WITTl ILLUSTRATIONS OF Till- si>K< BY GEORGE W. TRYON, JR. CONTINUATION BY HENRY A. PILSBRY, CoNSKKVATOK OK VHK CoXniouxiirAI. SECTION Ol THE Ni.TlTRAL SCIKNCKS «)K PlI I LADK1.1MI 1 A. Vol. XIV. POLYPLACOPHORA, ( Chitons. ) LEl'IDOl'LKURID.K, ISCHNOCH1TONID.K, CHITO> PAU1D PHILADELPHIA : isluMl by Concholop-i<-<een much neglected by Conchologists. This may !><• due to the fact that their characters are not generally understood, or even seen in ordinary cabinet specimens; and again, no illustrated \\<>rk treat- ing the group scientifically has hitherto been produced. Certain it is, that if the serious study of this group be once begun, its at: tious will be found to equal or excel those of any other fain; The numberless modifications of form, the beautiful adapt structure to life-habits and station, the marvelous parallel develop- ments, producing almost identical structures in totally diverse phyla, — all distinguish the Polyplacophora as preeminently int< ing among mollusks. The author begs those who may use this work to begin by taking apart one specimen of each species to be studied ; then find the genus by the Key on page xxviii. After a certain amount of practice the genus may be ascertained by removing valves vii and viii only ; but guessing it from the external features is in most cases uncertain and unscientific. As a rule, Chitons tell no secrets to those who will not take the trouble to disarticulate them. It is hoped that describers of new species will hereafter state the generic characters of their novelties. It is as rational to describe a bivalve without examining its hinge-teeth, as to notice the outside only of a Chiton. The synonymy is believed to be practically exhaustive, ex that useless references to mere lists giving no new information are omitted. Attention should here be directed to the new theories of the origin of important structures of shell and girdle, given on pp. i\, \ii ; to the original system of classification (p. xxiii), and the phylogenies (pp. xxvii, xxviii). The new species described herein which are credited to Car/ rest upon his types when the descriptions are g »» H* Mt. (as in the case of Callochiton princeps, p. 50). In cases where I have given original descriptions of new species, whether the specific names be Carpenter's or my own. the types are understood to be the ment described by me, in the collection of the Academy; wherever and whatever the original < mens may be. A case in j...int is /> •// ocrtor, p. 60, and /. conspicuus, p. 63. It is liy this expedient that confusion can be avoided in cases of real or fancied wrong identification, on my part, of Carpenter's .V . species. Many new species not illustrated in the body of the work are figured from the typos in the Appendix. The Appendix should always be consulted when a species is not found elsewhere, as forms .M known generic position have been included therein. e grateful task remains of acknowledging assistance from scientific friends and institutions. Through the intervention of DR. \\"M. H. DM. i.. Honorary Curator of the Department of Mollusks, U. S. National Museum, the writer has received from S. P. LAV-- . Secretary of the Smithsonian Institution, the drawings and .i/v prepared by the lamented PHILIP P. CARPENTER upon this group, a work of priceless value, embodying the results of many years study of the subject. Throughout the text of this volume will be foun fcfl from this MS.; such quotations in every case being idly credited. For the loan of a large number of type spec- iim -us from the Smithsonian collections, the writer is indebted to the nued kimlnesi of DR. DALL. To J. F. WHITEAVES of the ula Geological Survey, PROF. WHITFIELD of the American ••urn of Natural Hi>tory, New York City, PROFESSOR F. W. of Christchurch, New Zealand, and many other con- chologists, the thanks of the author are due for specimens presented or loaned. H. A. P. MANUAL OF CONCHOLOGY. MONOGRAPH OF THE POLYPLACOPHORA. Class AMPHINEURA. Bilaterally symmetrical mollusks, the nervous system consist of four (two lateral and two ventral or pedal) parallel cords, me* in a cerebral ganglion ; other ganglia feebly or not developed. Anus posterior and median ; head without tentacles or eyes. The Amphineura or Isopleura constitute one of the five primary divisions or Classes into which the Mollusk phylum divides ; and it is, in many respects, the most primitive of all. This class has been by most authors considered a sub-class or order of Gastropoda ; but the fact should be distinctly recognized that the characters com: to Gastropoda and ^Amphineura are either features possess* (hypothetical) primitive rnollusk, or are peculiarities evolved in response to similar habits of life. The Patellidce among Gastropoda have been repeatedly compared to the Amphineurous family Chitonidce; but the branchial cordon of Patell" is. .in no way homo- logous with the gills (or ctenidia) of Chiton, and the nervous and digestive systems are profoundly different. The class Amphineura is divisible into two Orders : Order I. POLYPLACOPHORA. Dorsal surface bearing eight in eating shelly plates ; head divided from the body ; gills numerous, occupying a lateral groove on each side between the foot and the encircling mantle ; foot adapted to creeping ; genital organs and nephridia paired ; sexes distinct ; radula well developed. Order II. APLACOPHORA. Body subcylindrical or y.rmitorm, without shelly plates or valves; foot rudimentary or aborted, the mantle cavity being reduced to a ventral groove terminating in a posterior cloaca containing the rudimentary gills, and the outlets of anus and nephridia. (v) vi POLYPLACOPHORA. ler POLYPLACOPHORA Blainville. The further division of this order into families and genera will be found on page xxiv. The following notes on the morphology of Chitons are mainly restri vaturea important from a phylogenetic or taxonomic standpoint; the primary object of this work being, of course, the establishment of a natural system of the Order. Tin. SHELL. The shell in Chitons consists of eight imbricating pieces or valves, bound together by a leathery girdle of connective tissue. The valves, when freed of the girdle by soaking a few hours in water, are seen to be of three forms: the anterior, (or "head valve") semicircular in outline its apex elevated: the intermediate (sometimes called " central " or " median ") valves, squarish in shape, and the poste- •r " tail valve," which is like the intermediate valves with the addition of a sloping surface behind the apex or mucro. In struct- 'he wives are composed of two layer*, generally '/////V different in color and texture ; an ont'T AI»/»T, culled by Middendorff the tegmeu- tum, •///«/ ne -reat phylum of Chitons. Asa rule Fig. 2. Intermediate valve oftne head-valve is sculptured all over Atm*tk9(hittt(if/HiWiii showing / like th« lateral areas. The posterior insertion plate, and Ue fig. 4) is divided into a central *alnral Uni1 and a | .iiva : the former being ar to the area so named in the intermediate valves POLYPLACOPHOR \. VII and the latter corresponding clo>ely in .-rulptun- to the lateral areas' In some genera the muero i> near or at \\\> valve, and the posterior area is then reduced to a narrow altogether absent (see pi. OL', li. 17, I*;. In position, ti. may be either anterior (pi. -^l liir. 1*3), or media,, < pi. 17, i ••i«r (pi. .VJ, figs. 22, I*:!) ; and it may be either elevat^l | fig. 9-J), or depressed (pi. 39, fig. 41), the last being sometime culled a Hat or planate mucro. THE INNER LAYER OF Tin: VALVES (articulament i > i / 1 I- larger than the tegmentum, projecting in front in two lobes called sntural lamince, which are separated by a median bay, the j"ytl sinus. At the sides of the intermediate va! and around the semicircle of the end valves, most Chitons have projecting plates called insertion plates, to whieh the girdle is attached. These are •*» commonly cut into teeth by transverse slits. From the slits to the apex of each valve inside, run slight grooves and rows of pores, known as slit-rays; often they are obliterated, but in forms having a highly developed system of sense-organs in the tegmentum, the Figs. 3, 4. "intermediate and PareS °f the ^W* 9Q rve &S D6rve posterior valves of Ischnochiton foramina. The teeth are sometimes conspicuus. finely cut or crenulated, (technically " pectinated ") between the slits ; and in some forms the edges of the teeth are thickened outside, or " propped." Fig. 3 represents the interior of the fourth valve of an Ischnochiton, showing the slits, teeth, insertion plates, etc. The tegmentum is essentially cuticular in nature. It consi>' a chitinous foundation substance, impregnated with salts of lime. It is perforated at the surface by a multitude of minute, definitely arranged pores of two sizes, called by Moseley, the larger //<"/<*/"/ the smaller micropores (see pi. 52, fig. 28, showing two megalopores and many micropores). Each megalopore leads into a cylindrical chamber which is continued below into a wide canal, ffhich as it penetrates deeper toward the plane of junction of tegmentum and articulamentum, curves outward toward the girdle-margin of the former. On reaching the plane of junction it joins a plexus of viii POLYPLACOPHOBA, main canals which ramify horizontally in this plane, and find open- ing from tin- valves at the eaves, or outer bases of the teeth and anterior sinus. From the sides of the megalopore chambers or from the deeper plexus of canals, are given off fine canals which perforate •••irmmtu: illy and join the bases of the micropore cavities. All of these canals are occupied by fibrous and nerve tissues con- tinued in from the girdle and interior. From these ramifications are given off l»rum -lies to each megalopore canal, in the superficial chamber of which they expand into obconic knobs of highly refract- ing tissue, sensory in function, and in all probability tactile. These knobs are calk-d l>v Moseley, megahesthetes ; they are capable of being somewhat i'1-otnidi d t'nmi the mouths of the pores. The micro- pores hold exactly -imilar but smaller sense-organs, the micr (Esthetes. These structures are found in probably all Chitons ; but in certain genera they are subobsolete. In others some of the megalaestlietes have become transformed into eyes. These are connected with the network of soft tissues, and occupy pear-shaped cavities like the true megabesthetes. On one side the bulb of the pear, more or less near its extremity, is closely applied to the outer surface of the tegmentum, and here it-; wall is pierced by a circular aperture, the pupil-like opening. This opening covered by the cornea, the periphery of which extends to a considerable distance beyond its margin all round. 6 cornea is a concavo-convex, watch glass-shaped lamina, trans- parent, and calcareous in structure, being continuous all around with the superficial calcareous layer of the tegmentum. "The pear- shaped cavity of the eye in the tegmentum is lined by a dark brown pigni mbraiM- of a stiff and apparently somewhat chitinous texture, which forms the eye capsule. This capsular membrane exactly follows the shape of the eye cavity, except near the surface of the tegmentum, where its margin curves inward beneath the 'rming a sort of iris and bounding the circular pupil, h is of less diameter than the cornea. The ;ip2rtureof the pupil is occupied by the front surface of the lens. The lens is perfectly parent and ! :md strongly biconvex. It is filled in behind the iris aperture. It is composed of soft tissue and dissolves in strong acetic acid gradually and completely, showing a fibrous dis- atructure in the process. There is a space between the front surface of the lens and the cornea. ' Within the pigm. nt« d tubular prolongation of the eye capsule POLYPLACOPHORA. the numerous fine fibres composing the optic nenre beoome lepai from one another and loose. Immediately imrought to boar upon the growing edges of these plates, that their development is duo, in precisely the same manner that the enlarged joints of a laborer's hand are the result of :m pacts and strains to which they have been subjected. All Chitons which live in situations exposed to the buffeting of the surf, possess highly-developed in>ert ion-plates, which are, moreover, in nearly every cases. : >u and el-ewhere, JJn/ojiluira in Australia and Japan, all rmiarkable.forthe great development of strong, rough insertion plates, and equally for the very exposed situations in which they live, »t'ten subjected in the full force of the surf. It is, of course, the belief of the writer that characters acquired by the action of natural forces, acting upon many generations, become hereditary ; but in tural selection " no doubt has had a certain consider- able effect, although the process has, I believe, been mainly one of selection from definite variations produced by the mechanical causes described above, not selection from indefinite variations in all direc- tions. On the other hand, forms living in less exposed stations, such as ath stones at or below low water, have thin, smooth insertion plates (IMfioeAifoft) etc) ; and at great depths, where the motion of the water and its power of transporting pebbles or stones is reduced to a minimum, and where therefore the valves of the Chitons are not • t to impacts or strains from without, the species are found to be entirely without insertion plates. This excessively weak organ iza- tion has been transmitted unchanged from the Paleozoic Chitons, all of which lacked insertion-plates; and it is a significant fact that [Ofl typ,- lias been able to exist to the present time only in deep water, where the forces which I believe to have moulded the modern Chitons do not act, and where competition in the life-struggle is less severe than in the shallows. In this connection the case of J't'U-l/Jwra (PlacojiJinroj,*!*) ntlnn- tica shoul i Thi> species was dredged off New England in •ni\\n tins., — depths beyond the limit of the penetration of li-ht, and of course far beyond the reach of appreciable water movement, r l>y currents or surface disturbances. The conditions therefore demand no stronger apparatus for the attachment of the valves to POLYPLAOOPHO1 XI the girdle than is possessed l>y Lepidopkurui ; ami in fart \\o find that its insertion plates are reduced to very >hort Mmm anterior " teeth " arc small, low, unevenly notched, and not n« as long as the overhanging eaves. It is only n<-r. that the genus Ptaxipkora, tin- nearest ally of I'/m-ojJi" remarkable for the length of its strong, regularly slit insertion plates. The same is true of the entire family Mnjmli'n^r, to whieh these genera belong. In Pln<'ophorop«i* u/A/.//.//m wo have, there- fore, a member of a family of littoral Chitons, which by descent into the abyssal region has partially lost by retrogressive development through disuse the characters originally evolved to fit the ancestral forms for existence in the littoral zone. Further deep sea researches will probably reveal other cases of degeneration along the lines here indicated ; and it is not impossible that forms as destitute of insertion plates as the genus Lftpidopleurus have been produced from hi. types by retrogessive evolution ; but there is at present no evidence of the existence of such forms. THE GIRDLE. This organ variously called ligament, zone, or girdle, is a baud of connective and muscular tissues extending around the valves, the edges of which are imbedded in it. The surface of the girdle is variously clothed with scales, spines, haiis or spicules, or is naked. The armor, whether of spines, scales or hairs, consists of a chiti- nous foundation more or less infiltrated with lime. The girdle- appendages vary greatly in development among closely allied species; but the general type of covering is a moderately constant generic character. In some forms the girdle encroaches upon or entirely covers the valves. In some genera having a posterior sinus in the tail-valve, the girdle has a corresponding sinus or slit ; in others it has no sinus, but in life is always curved upward into a posterior conduit, serving for an outlet for the anus and gills. In some forms having hairy or spiculose girdles, the hairs or spicules are gathered into tufts or groups at the sutures (i. e. lateral points of junction between valves), and around the anterior valve ; issuing from pits or pores at those places (see pi. 5, fig. 97). In their incipient stage, these sutural tufts are merely the gathering together of two or several of the ordinary surface hairs: in their full development they are dense clusters of long spicules ; and in their decadence only a small pit or pore remains. The presence of Xll POLYPLACOPHOR \ . pores or tufo has been considered by systematists a character of great value; but not with justice. The fact is that at least three H in the development of Chitons has this feature appeared independently ; first in the genus Hemiarthrum of Lepidopleuridce, form having a pore at each suture, and six around the head valve; second in Call; / (culminating in Mopaliidci) where pores are excessively inconstant, and the number around the head valve indefinite (0-6) ; and for the third time in Acantho" "he and its derivative l'nj/>foplacidimj pores or tufts ofsjtiiic* <>n the sides. A9 7 • 'in 1 1 posterior valves divided '•> several ' 'I of the cent ml -mli-e* into two lobes. a. Containing Chiton, Tonicia, Acanthopleura, Schizochiton. b. Containing Corcphium, Plaxiphora, Onithochiton, Enoplo- clii- ['-. Radsia, Callocliiton, Ischnochiton, Leptochiton, subsequently a-l.lrd by Gray.] B. The plate of insertion of all the valves with only a single notch on The valves more or less covered ; the hinder valve I [dales of insertion (as in the central valves'), with only a single notch <»i cat-h side, and a concave sinuosity below. a. Contain.- M<»palia. Katharina, Cryptochiton. // Mi • '• >/ >t!i 3, when PHII.H' P. CAIMT.NII it (born in Bristol, England, in 1*1 •». died at Montreal, Canada, 1877) published a catalogue of the V rican f..rm- Urit. Asso. Rep). This was followed by - upon the California!! and Atlantic Chitons, and finally by the preparation of a monograph of the entire group. In work upon this great undertaking, Dr. Carpenter examined critically the Cumiugian and British Museum collections, contain- ing most of the types of Broderip, Sowerby, Gray, Reeve and H. .•ii5»; and besides, nearly every collection of any size in England and America, including thoM of A. Adams, Angas, Dr. A. A.Gould, comb, Jay, Haines, the State of California, the Smithsonian Institution, Museum of Comparative Zoology, etc. The information gained from the examination of this great amount of material was in process of re-arrangement at the time of his death, in 1877, that ing to the Leptoidea and Ischnoidea being practically com- pleted. A vast amount of work had been done upon the other groups, but his studies of them were far from finished. A large number of drawings had been prepared under Dr. Carpenter's direction, mainly by Messrs Emerton, Foord, and Smith. The whole «»f this J/.S. being devised to the Smithsonian Institution, \VM. II. DALL published (Proc. U. S. Nat. Mus. 1881, p. 283- 7 tfie genera of Chitons, giving Carpenter's complete classification, and brief diagnosis of the new groups, of the Carpenterian names therefore date from this time; although in 1873 a large part of them were included by Carpenter in u table printed by the Smithsonian Institution, showing the characters of the " Regular Chitons. " The fact that the distribu- tion of this table was limited to Carpenter's personal friends and correspondents, that it was never advertised or offered for sale, was not sent to most (if any) public scientific libraries nor noticed in i tific journals, prevents ug from dating his names from the time publication. The following table shows the Carpenterian classification in full. The group and family names given by DALL in 1889 ('Blake" Gastropoda) are added in parenthesis. Order POLYPLACIIMIOL'A (Polyplaoophora Dull;. Section I. — Chitones regulares BoOHITON] \ I'ull;. Head and tail plates similarly artinilat* •r- !»r. Beaiiella Dall. /V/«/(v//oy»A //ra Guild! ng. Section II. — Chitones irregulares (OPSICHITONIA Dall). Tail plate abnormal or with a sinus behind. E. SCHIZOIDEA (Schizochltonidce Dall). Tail valve fissured. a H. and A. Adams. ochiton Gray. Aulacochiton (Shuttleworth) Cpr. F. l*i..\« im<>i:< HIT.E Rochebr., genus Acanthochites Risso. 1 'an illy ( '11 i; i Rochebr., genus Chcetopleura Shutt, spe- <• placed upon them. The same is true of his figures of fossil Chitons. From the above sketch it will be seen that the chief workers upon the classification of Chitons have been few in number, the publica- tions of BLAINVILLE, GRAY and CARPENTER successively mark- ing epochs in the taxonomic history of the group. POLTPLAOOPHOBJL Ci, \-iri. M-ION OF Cmi< The classification given in this work is h:H.-d mainly upon < -har- acters furnished by tlu- articulatm- BUrfeoei «•»' tin- v:ilv«-s. Th«: hard structure in this group is o.mparal.lr to tip ton in the great variety of stresses to whirli it is suhj<-«-t. Karl. valve is not only acted upon by external forces and its i.ody mus- cles, but by the valves before and behind it, and by th<- ^m11' • Hard parts of great complexity have thus arisen, offering to him who can decipher their story clues as valuable for the construction of genealogical lines as have been found in the limb-bones of mam- mals, or the hinge-teeth of bivalve mollusks. The development of the gills, foot and girdle has been given due weight, and for the first time, systematic use has been made of the sense organs of the shell (tegmentum), and the system of sculpture of the latter. The non- differentiation of the dentition throughout the group has prevented the use of that character usually so important. The Polyplacophora known to us, form a group remarkably homo- geneous, when we consider the vast antiquity of the stock, fossil forms are yet few in number and imperfectly known ; so that all attempts to trace the mutual relationships and descent of modern genera must still be based upon the morphology of living forms. The complex inter-relations of the various families and genera, the number of phyla, and especially the wonderful parallel develop- ments of different stocks, all render a linear arrangement of groups highly unsatisfactory. The accompanying diagrams show the mam facts of classification and descent much more clearly. It is commonly known that the earlier (Paleozoic) Chitons are without exception, destitute of plates of insertion, and belong, therefore, to the family Lepidopleuridce. This family has survived to the present day, but the species are now few in number and of small size. The higher genera of Lepidopleuridce possess insertion plates on some or all valves, but they are unslit; and it is to tl branch that the genesis of the higher Chitons is to be traced lowest Ischnochitonidce known have already become well differenti- ated by the development of a definite system of slits. The Ischnoid stock must be regarded as a synthetic or uuspecia ized type of Chitons. In other words the common ancestors of other families of the Chitons (except Lepidopleuridce^ would proba- bly, if known to us, be classed as ItoknochitonM*. From this general- ized Ischnoid stock specialization proceeded in two directions: XXIV PO.LYPLACOPHORA. toward greater definiteness in the positions of the slits, and often nl the degeneration of the >h» -11 ; leading (a) through Callisto- placiiuf to the Mopnliidn, and (6) through Acanthochitidce to covered forms, Cryptochiton, and to worm-like forms, Cryptoplacida* ; the last having fewer slits than any other Chitons. In the other direc- tion (II) the slits became generally more numerous, the insertion- plates are roughened for the stronger adhesion of the girdle, the valves increase in general effectiveness as a protective armor, and thrir sense organs became highly developed. This phylum (Chi- nlminates in / vthoplewra, Schizochiton, Enoplo- chiton, Liolophnra, etc. ; and may be regarded as the highest group of Polyj'hu'ophora. NOTK. — It must be understood that in cases where the classifica- tion below given differs from that in the descriptive part of this work, the former represents the mature views of the author. Page n the text, should be cancelled, as it was written when but a small portion of the groups there discussed had been studied. The synopses given on pp. 24-25, and 148-149 also require correction. pris of Classification of the Order Poly placophora. I. Superfamily EOPLACOPHORA. Family Lepidopleiiridce Pilsbry. nus Lepidopleurus Risso. p. 2. Section Deshayesiella Cpr., p. 16. Genus Hanleya Gray, p. 17. * Genus Hcrniai •thrum Cpr., p. 19. * Genus Microplax Ad. chttnltil>lrur:i Sluittlw., p. 27. Genni l'all<><'liit«>M Dull, p. 256. Genus Dinoplax Cpr., p. 2~> I. * Genus Ischnochiton < Jniy, j>. 53. Subgenus Stenochiton Ad. & Ang., p. 55. Subgenus Stenoplax Cpr., p. 56. Section Stenoradsia Cpr., p. 61. Subgenus Ischnoplax Cpr., p. 64. Subgenus Ischnochiton s. s. p. 87. Section Lepidozona Pils., p. 125. Section Radsiella Pils., p. 139. Section Ischnoradsia Shuttl., p. 144. Subgenus Heterozona Cpr., p. 65. Subfamily Callistoplacinse Pilsbry, p. 259. Genus Callistochiton Cpr., p. 260. * Genus Nuttallina Cpr., p. 277. Subgenus Middendorffia Cpr., p. 282. Genus Craspedochiton Shuttlew., p. 285. * Genus Angasia Cpr., p. 286. Genus Callistoplax Cpr., p. 288. Genus Ceratozona Dall, p. 290. Family MopaliidcB Pilsbry, p. 292. Genus Mopalia Gray, p. 294. Genus Placiphorella Cpr., p. 305. Genus Plaxiphora Gray, p. 311. Section Guildingia Cpr., p. 329. Section Fremblya H. Ad., p. 330. Subgenus Placophoropsis Pilsbry, p. 313. Family Acanthochitidce Pilsbry. Genus Spongiochiton Cpr. Genus Acanthochites Risso. Section Notoplax Ad. POLYPLACOPHORA. Section Cryptm-onchus Blv. Section Loboplax Pils. Genus (?) Leptophix Cpr. Genus Katharinu Gray. * Genus Amicula Gray. * Genus Cryptochiton Midd. Family Cryptoplacidce Dall. Genus Cryptoplax Blainv. Genus Choneplax Cpr. III. Superfamily TELEOPLACOPHORA. Family Chitonidce Pilsbry. Subfamily Chitoninae Pilsbry. Genus Chiton Linn., p. 149. Section Radsia Gray, p. 189. Section Sclerochiton Cpr., p. 188. * Genus Eudoxochiton Shuttlw., p. 192. Subfamily Toniciinae Pilsbry. Genus Tonicia Gray, p. 194. Section Fannettia Dall, p. 212. Genus Acanthopleura Guild.', p. 213. Subgenus Mesotomura Pils., p. 218. Subgenus Acanthopleura s. s., p. 219. Subgenus Maugeria Gray, p. 226. Subgenus Amphitomura Pils., p. 230. Subfamily Liolophurime Pilsbry, p. 232. Genus Schizochiton Gray, p. 234. * Genus Lorica Ads., p. 236. Section Loricella Pils., p. 238. .. Genus Enoplochiton Gray, p. 252. Genus Onitlmdiiton < iray, p. 244. Genus Lioloplmra Pilsl.ry, p. 239. i-oi^ ri..\' 0FB xxvii l>h<,loy:n. clear to me aud require much further investigation ; but the vie expressed on pages 259, 260 may possibly suggest super-generic groups. POLYPLACOPHORA. of the genera of Chitonidcz. I I d a 1 K C o o -r .r r Liolophurince ClIITONIDJE ANALYTICAL KEY TO GENERA OF POLYPLACOPHORA. a. Fa/re» /ac&mp imertion plates, or if present they are wislit (Lepidopleur* b. Valves entirely exposed, not immersed, Insertion plates completely absent, LEPIDOPLEURUS, p. 2. oc. Head valve having an insertion plate, grooved outside hut unslit; valves ii-viii without plates, -mile xpinuloBe HANLEYA, p. 17. ccc. Head and tail valves only having unslit insertion plates; girdle thick, sparsely downy, with sut- ural pores HEMIARTHRUM, p. 19. POLYPLAOOPHO1 bb. Valves partly covered, the exposed portions .-mall, sep- arated MI n, aa. All valves possessing insertion plates ; valrr\,\ \ii ing slits ; teeth smooth or bid 4ig fitly roughened bci>< » » f/" r closely, finely pectinated; valves Iwkimj b. Surface of intermediate valves divided into lat« r:i central areas by a diagonal (often in.listinct), extend- ing from beak to outer front angle of tegraentum ; or if this is not clearly the case, the posterior valve has un even, crescentic series of well developed teeth ; all valves having slits. c. Posterior valve having a crescentic series of well developed teeth (Ischnoch \\m> > d. Anterior and side slits not corresponding in position to external ribs (Ischnochitonina.) e. Valves porous at the eaves, appar- ently smooth outside or nearly so ; teeth sharp, smooth; girdle naked, sparsely hairy or densely covered with elongated corneous bodies, the visible ends of which appear like diamond- shaped scales (Tonicelloid group). f. Sutural plates not connected across the sinus ; girdle naked ; side-slits single ; gills shorter than the foot. g. Median valves having a me- dian slit filled with carti- lage, SCHIZOPLAX, p. 46. gg. Median valves normally < al- cified, TONICELLA, p. 40. ff. Sutural plates connected across the sinus, or side-slits several, or both ; girdle either sparsely hairy, naked, or with compact diamond- patterned covering; gills as long as the foot, CALLOCHITON, p. 48. (This includes the typical forms of Trachyradsia, p. 83.) jgjf. Girdle with chaffy scales or pap- XXX POLYPLACOPHORA. illose ; gill-row short or long, TRACHYDERMON, p. 67- ee. Valves solid at eaves, generally with beaded sculpture ; teeth sharp, often rugose outside; girdle leathery with few or many hairs or spiculse, never scaly ; gills as long as the foot (Chat;* - pleuroid group). /. Sinus squared, the sutural plates not connected across it; girdle hairy or naked. g. Mucro in front of the mid- dle, CH^ETOPLUERA, p. 27, [and appen'H.r. gg. Mucro decidedly posterior, PALLOCHITON, p. 256. ff. Sutural plates connected across the sinus ; girdle thick, bearing minute clumps of short spicules, DINOPLAX, p. 254. eee. Valves solid at eaves ; girdle densely covered with imbricating scales, rare- ly elongated like fluted pillars (Isch- noid group) ISCHNOCHITON. /. Shell much elongated, narrow (gills short at both ends ; foot no- tably dilated and produced in front, at least in some of these sections). g. Girdle scales uniform ; mu- cro near the middle h. Valves longer than wide, roundly arched, with several side slits; animal Julus-like, Stenochiton p. 55. hh. Less elongated; Amer- ican forms Stenoplax, p. 56. gg. Girdle scales very unequal ; POLYFLAOOFHOfl raucro el / ff. Shell not ^n ally .-IniiL g. ( iinllc clothed with large ami small iiit'Tiningled scales, Heterozo gg. Girdle scales regular, uni- form. h. 1 slit on each side of median valves i. Girdle scales flat, lachnochiton, p. 86. ii. Girdle scales very convex, Lepidozowi, \>. 1 '_'•"». hh. 2 or more slits on each side, i. Girdle scales flat, Eadsiella, p. 139. ii. Girdle scales con- vex, Ischnoradsia, p. 144. dd. Anterior and side slits corresponding in position with external ribs (Callistoplacinae). e. Surface of valves having strong radial ribs ; girdle densely clothed with im- bricating scales, CALLISTOCHITON, p. 260. ee. Surface of valves granulated or peb- bly ; girdle not densely imbricated with scales. /. Anterior valve with more than 7 slits ; sinus very spongy ; mu- cro posterior, NUTTAI.I.INA. J>. -77. ff. Anterior valve with ."> slits ; mu- cro subcentral, not posterior, g. No sutural pore tufts. CRASPEDOCHITON, p. 285. gg. Sutural pore tufts present, A NC.ASIA, p. 286. \X.\ii POLYPLACOPHORA. e> f. Surface of valves wrinkled or ribbed ; girdle naked except for hairs or cor- neous spines. /. Valves having very strong radial ribs; girdle naked, with sutural tufts, CALLISTOPLAX, p. 288. jj. Valves not very strongly sculp- tured ; girdle tough, with corne- ous curved spine-like processes, CERATOZONA, p. 290. Posterior valve having a sinus behind, with one slit or none on each side ; girdle hairy or nude, never scaly (Mopaliida'). See key to genera on page 293. 66. Surface of intermediate valves divided into a narrow dorsal area, and latero-pleural areas, the latter formed by the union of the lateral and the pleural (or sides of the central) areas ; valves more or less covered by the naked, spiculose or hairy (never scaly) girdle ; gills gen- erally short (Acanthochitoid phylum). c. Posterior valve either having well developed slits, or a posterior sinus, or both ; not funnel-shaped, anterior valve with 5 or more slits (Acanthochiti- dce, see next volume for species). d. Valves not completely covered by the girdle, the first 7 having their apices posterior and marginal. e. Anterior valve having 5 regularly placed slits; exposed portion of each median valve much longer than wide. /. Girdle provided with pores bear- ing tufts of bristles ; posterior teeth wanting or irregular ACANTHOCHITKS. ff. Girdle naked ; posterior valve with 6 slits, the teeth even, spread- ing LEPTOPLAX. jfjfjf. Girdle spongy, produced forward as in Placiphorella SPONGIOCHITON. POLYPLACOni«H:\. ee. Anterior \ larly spaced, mon- than •"> ; j.o.st«-i valve with :i median angular t its edge with several uni-<|ual notched or slits; exposed part of valves flask- shaped I\ \iiii eee. Anterior valve having 6-8 un< slits; posterior valve 2 slit- ai, median wave; expoM.I part of each valve far shorter than the ridge of the valve, heart-shaped A.MICULA. dd. Valves completely covered by the girdle, their apices not marginal, CRYIT. L94, cc. Girdle covered with calcareous spines or spinelets, ACANTHOPLEURA, p. 213. bbb. Valves having eyes (rarely subobsolete) ; posterior XXXIV POLYPLACOPHOKA. valve either having a deep sinus behind, or lacking the insertion plate altogether (Liolophurince). c. Median valves having eyes developed only on the diagonal ribs. Sinus notably narrow and small. Insertion plates of tail valve a low, rounded, rugose ridge more or less notched, slit or waved upward in the middle behind, or sharp, long and pectinated. .ves developed on radiating ribs of all valves; the ribs of head valve correspond- ing to internal slits ; girdle having minute spines ; shell elongated, posterior valve and girdle slit behind SCHIZOCHITON, p. 234. '/ot concealed by the girdle. B. Girdle without pores. Genus I. LEPIDOPLEURUS Kisso, 1826. Insertion plates absent. Girdle with minute, gravelly, smooth or striated scales, usually with a marginal fringe of longer scales. Type, L. cajetanus Poli. Section Deshayesiella Carpenter, 1878. Girdle having delicate spines and chaffy scales. Valves curved and beaked ; sutural plates and sinus as in Leptochiton. Type, L. curvatus Cpr. Genus II. HANLEYA Gray, 1857. Front valve having an insertion plate which is grooved outside but without slits. Intermediate and posterior valves without inser- tion plates. Girdle finely spiculose, without pores. Type, JL huii- leiji Bean. BB. Girdle with pores at the sutures. ( ienus III. HEMIARTHRUM Carpenter, 1876. Head and tail valves having smooth, unslit insertion plates, the intermediate valves without insertion plates. Sinus broad and 1 (1) 2 M i'iiM>i-i.i:rRU8. spongy. Girdle downy, having small, tufted pores. Type, H. set- ulosiun ( 'j.r. A A. Valves partly covered, the expose< small and sepa- rated. \\\( K< H'LA X Adams & Angas, 1804. Insertion plates smooth and thin, well developed in all the valves, ml plates and sinus obsolete. Girdle thin, most minutely gran- ular, not jM»riferous. Type, M. proyiAd. & Ang. Gem.- I. LEPIDOPLEURUS Riaso, 1826. pleurus Risso, Hist. Nat. 1'Kur. M.'rid., iv, p. 267, 1826, in : t species /,. c,ij*t>tnns Poll). — SARS., Moll. Reg. Arct. ., 1*7*, }». 1 in. Nut L'-ftidoplenrus of H. & A. Adams, Car- : 'all. ft •i/.—Lrptorhiton GRAY, Proc. Zool. Soc. Lond. 1847, j». 1 H I1.. M.. p. 182, 1857.— CARPKM I:K, J/& p. 1,— - ; . Mus. 1878, p. 3\±.—Leptochiton, in part, of H. A A. A i. A MS, Gen. Rec. Moll, i, p. 473, and of CHUM , Manuel, i, p. 381. In / itioii plates are completely absent; the girdle is narrow, with minute striated or smooth scales, and some _rer scales at the edge. The present genus has hitherto been known as Leptochiton, but :vji-i-tioM of that name seems to be inevitable as will be seen DO the following: // • '. of the name Lfj'irl»i>/>-urii.<. The first publication of Lepi- l in Kisso's Histoire Naturelle des principales pro- !••• Mi'ridiojiale, vol. iv, p. 267, 182G, where ii is •«NJ as of Leach's ww. It is character! zed as having the triangular lateral areas elevated and the girdle covered with small scales, and in it are includ<-d .711) L. cayetanns Poli, (712) L. coral/inn* n. sp. and (713) L. sul&itus n. sp. Of these, the first species belongs to the v '• . Mib.-e.juently named I,e]ttocliiton, and the two latter belong to the genus Chiton as restricted to Lin nuns' type. It is there!'"!.' evid.-nt that if u>.-d at all. the name Lepido- plcn ;.rojM-rly be ii>,-d foi | ,,,,lv. It is greatly to be regretted that it was not so used by < iray, as much subsequent confusion would have been avoided. The rej.ublication of the i.i PIDOPLE1 i '{ •Trims in ( Iray's edition of L.-arh' I/,- - jn '. need not he omsidrivd here ai ii \\-.\- no hcarim: upon mmi.-n- rlatun>. In 1868, Me«r», II. ami A. Adams, in tli«- <, Recent Mn//nwt, adopted llisso's nanir for a I:ir_r(i li-t 0 mainly of Ttehnochitoni, l>ut inrludinir al Lcpfnchitttn, etc., among them L. m/v/. /////.-• I'oli. • priitrr in his later writing used LepidopUufW !•• rover tliat '_rroiip of Isrlmorhitons liavini: the girdle clothed with large, .-niooth nm- \ •« A 0-100 fms. ; Lofoten Is. 300 fins. ; Greenland: South to Gulf of Lyons, Vigo, Spain (and Dalmatia /). Northern I'lirific. — .-1 tnskn, at Unalashka, Shumagins, Port Etches and Sit/:n II<;r/i<>,\ o'-loo t'ms. 4 LEPIDOPLE1 ii m*.}. Conch. 111. f. 1()4- 3& HAM Brit, M-'ll. ii. I>. -Jl(>. : Brit. < «nch. iii, p. -J17: v. p. l'. I. — Lr/.i'lnjJtuirns r'tnrellntn* BARS, Moll. .. p. IN. t. 7. f. 6; t.i,f.&.—Lq)tochiton i/>, p. :;.- - Du.i.. Proc. I". 6. Nat. Mu,. 187* Linn..//'/' Hanlcy. — Chiton as ellus MIDI.., not .if Lowe.— ( An r., n..t Payr. — / Ch. isliimliru* Tli without careful inspection will usually be confounded wiih small specimen- of Tr'irliinlcnmiH iiUnis, but a --lance at the sculpture i- -utlicient to separate it. From several other species of ailily distinguished, and a magnifier is indis- •ahlr. The ditlerential characters are as follows: The pu.-tules which constitute most of the sculpture are arranged like overlapping coins or a solid-linked chain in lines which in the 1 area an- nearly parallel with the longitudinal axis of the animal. The lateral area- are distinct, and the pustules upon them in rather indistinct lines radiating toward the lateral of the valves, at nearly right angles to the lines on the dorsal ilpture on the mucro is more delicate than elsewhere. The apex of the po>terior valve is not sunken and is not so sharp -i>ecies compared with it here ; the girdle is scaly, with -mall, spino^e, transparent scales near the margin. There live Lrill plume- on each side, prominent and near the vent. pear to be two fenestra on each side. The lateral areas .(her portions of the valves are nearly always colored with blacki-h or frrniL'inoiis patches, but these, as with Treem to be really c<.mpo>ed of extraneous matter. In L. fuli- Ad. A: live., the pustules are much smaller, and while hav- ing a Lfeneral longitudinal arrangement on the dorsum, do not form llariy defined TOWS Or chains. The areas are not raised above the dor-uni. The shell is much larger and more elevated, with a :iken and «|iiite sharp posterior mucro. Tin- other nine ii"i raided but about them the sculpture is more regu- larly aliened than eUewhere. 1 have compared the valve- of a typical >|M-< -iinen from Korea, collected by Belcher. I figure of the sculpture i- very bad. as are nio-t of his details. L. alveolus di-tinct though it has been confounded with thi-. It- sculpti;! and rather ni..iv Sparse, LEPIDOPLEU1 ."i isolated puMiilr-, alxoliitcly irn-Lrular in di-l ril.ul i< •: same .-!/«• on the mucro ;in. The aicll of tin- back is | >eci 1 1 ia ll y P>und. the lat- : not rai^-d ami barely di>tiniMii>hai)le. The girdle seem I have compared typical examples. L. ooncmnttt Gould, from the types, ifl of i diilen-nt color, and has a much M router and different sculpture like line- of i L. inft'nir.rii.'S ( 'arpenter and var. rui/nln.* ( 'pr., are more like cinnii*, hut di-tin^-mslied from either by the peculiar ^irdl- with sul>e<|iial scales. L. nexn* ('arpenter more nearly resembles c.ancellatns but the sculpture is of separate, not lapping, rounded rhomboidal pu>n the mucrones are much more pronounced, and the white ground i- prettily marbled with black and gray inherent coloration. The name cancellattu is a misnomer, since it is only in certain lights that any trace of reticulation can be observed faintly. The young are flatter than the adults. It bears no resemblance to L. asellus, with which Middendorff united it, probably without a comparison. L. arcticus of Sars seems to be a finely grown variety of this spe- cies, if one may judge from the figures; at least, no differential characters are given which seem to be of a permanent character, and not subject to variation within the limits of a species. The gills occupy a space corresponding to the posterior quarter of the foot ; there are about eight or ten on each side. The mantle edge is plain and thick. The veil is plain. The muzzle is rounded, with a little papilla at the posterior corner on each side (Dall.) L. ARCTICUS Sars. PI. 3, figs. 59-63. Shell subdepressed, dorsal keel obsolete, lateral areas little con- spicuous. Posterior valve smaller than the anterior, subrhom- boidal, roundly produced in front. Median plates throe tim- long as broad, the front margin truncate in the middle. Surface of the valves nearly smooth, indistinctly granulose. (Sars.) Length 12 mill. Spitzbergen, Greenland, Vadso and Finmark, 20-10* • Lepidopleurus arcticus SARS, Moll. Reg. Arct. Norv. p. 11-, t. 7, f. 7.— Chiton aretiew JEFFREYS, P. Z. 8. 1882, p. 668. Dall, judging from the description and figures, considered tl form of L. cancellatus. Jeffreys, who found the - D the b LEPIDOPLEUBUS, ' Lightning' dred-ini:-, -ays that it differs from the white variety «if euf [--ascllus] in its comparatively greater length and more raised or arched form, in the less distinct or regular catenation of granules which OOVer the surface, and in the prominence of the lateral areas. I.. \i.\ r.M.rsSars. PI. 2, figs. 23-' H . Shell quite convex, hack equally arched, without trace of a keel or defined lateral areas : valve- rather elongate, the posterior larger than the anterior valve, half-round, truncated by a straight line in t'n.nt: median valves subequal, their posterior margins straight, rior margins lightly emarginate in the middle. Entire surface 1 witli minute ovate tubercles, regularly disposed. (Sars.) Length 16 mill. North Atl'tntir at Bergen, Lofoten, Finmark, 150-300 fms. ; Bay of Jiiwitt, ] i_>n-6fi4 fms. ; Gulf of St. Lawrence betiveen Cape Rosier \ 1C. /,„/„/ of Anticostild., 220 fms.; St. George's Bank, ',e, 150finfl, •dveolm (SARS ms.) LOVEN, Ind. Moll. Lit. Scand. p. L'7, 159, 1846. — I ii PREYS, P. Z. S. 1882, p. G68.—Lepidopleurus alve- olus G. O. SAI:>, Moll. Reg. Arct. Norv. p. 110, t. 7, f. 3 ; t. i, p. 7, ISlS.—Leptochitn,, alveolus DALL, Proc. U. S. Nat. Mus. 1878, p. :I17.— II A i 'DON, Challenger Rep. vol. xv, p. 12. L. i-i.i:«;i: \vvrrs Dall. Vn figured. Shell elongated, moderately elevated, regularly arcuate, without jugurn. Pale wax.-n, sometimes white. Valves wide, without • .s. Front and back valves more or less concave; posterior valve without elevated apex. Sculpture as in L. cancellatus, but th«- -ninnies larirer, lateral areas less defined. Sutural plates elon- gated. < iirdh- wide, densely beset with delicate scales. (Dull.') 1 Qgth !_'. breadth 6i mill. Near Dominica, West Indies, in 138 fms. Lepfoekiiok J,' rri i i i , and without the dinu'V hlaekish pai nt in- of either. / crl/ntu.< is narrower, higher, and \\itli a -harper medi:m aiiL'Ir. |M L. fnli t/iiiiifn.* the middle valve- are ihortei from front t<. liaek, tli.' sutural lamina- .-mailer and much more tri;iii'_:ular. Th- siirii of a niucro on these valves, hut in /,. y,/-/-///-//,,,////.* t in TO \» a beginning of one, <|iiitc perceptible. The latter i.- a pn.pi.rt ionallv wider and. Hatter species, with a stronger and more prominent girdle densely set with elongated silvery scales like short eeming to radiate from the median dorsal line. In a/tW//.< the lat- eral areas are barely perceptible. In belknapi they are raised, con- centrically rugose, and the pattern of the pustular arraiiL.rcm»! different and more irregular than that on the dorsum. In belktiapi LEPIDOPLEUR1 3. thin, narrow, and sparely 96l with small pel- lucid ipiculea Dear the mar-in. Ti ior mucro or up. lllr [Tile, in ^flop^ is prominent, overhangs a shallow J ami fV..,n its point there diyerp- anteriorly t\mr depr the anterior lateral an-l.-> of tin- plate, the inn. :idi-tant from each ot her and the outer Iiu,->. I'.etween the plat.- ^ >welled, formini: three rounded ridges, ruard like th.- leaflet- of a trefoil <»r clover, Nothing •iiblm- thi> ha> been •»!>«• rvcd on any of the other species which have oome under my notice. The >,,ft parts in spirits appeal- to Other Bpeciefl compared with it. It is evidently adult Tl'' Bent the form dredged l.y the 'Challen-er1 ,,tr mt Thilippines. Had.lon describes these specimens a< fullcws: S|l(l11- l>nttl.-. cloaelj Covered with larire, round, .smooth tuber- i an angle of about 110°. Sutural lamina- all. r valve.— With a few irregular lines of «rrowth, thickly •A ilh irregularly disposed tubercles. 'li:ltt> v^' ntral areas: with a shallow depression : -h Bide "f the median rid^., which givea the latter a pinched : his depn-sion is mo>t apparent at the hinder border The tubercles have a -eneral arrangement in ol.li.ju,' liiu-s ra.liatin- forwards from the keel and at the same time i" li' Btric to the umbo, but these two series of lines are not '. and the tubercles often appear to be irregularly dis- !' short eoncentric rows usually demarcate the 1 the lateral areas. Lateral areas: scarcely ap- ndicatin.i: a line of -rowth occurs at a short dis- Mle; tubercles irregularly disposed, with a ten- '.. however, to concentric lines. With a small subeentral umbo, behind which Interior area: the lateral lon-itudi- ""I '' tejugum to be slightly prominent and thus give^ the anterior inewhat trilobed appearance; the tuber- Bnded keel. Posterior area; with ooncen- i and el-.-elv >rt tuber, . thickly covered with delicate small oval scales; :ini1 more pointed scales occur along the border and in th- !vr> 8 .- ( irayish-whitr. Si/.,-. Len-th about rjmm.; hivadlh ~> mm. ; hriirhi inin. s. Fornmi- a short po-terior n»w, ^i\ <.r seven in number. This species is considerably lar-er and OOartOT than tin- |>i (L. benthut'). The tubercles are twice the size and <•!• ther, The shell IB also Comparatively >harply keel.-d, instead of having a uvntlv rounded appearance. L. BEVTHU6 Haddon. IM. 1, ligs. 1-13. Shell.— Delicate, brittle, surface with minute inc.,n^,i(MiMUs >ln.rt ridges more or less radially disposed, and studded with small tul.er- cles3. The sides meet at a rounded angle of about 100°. Sntural lamina- small. Anterior valve. — With minute scattered tubercles, which | towards the apex into low tubercular ridges, having a concentric arrangement. Intermediate valves. — Central areas: The minute surface ridges, when visible, are longitudinally disposed on the jugum, but be. radial or oblique on the pleura. The tubercles are round on the jugum, but becomeVomewhat oval on the pleura, and there appear to&be concentrically arranged, although in some valves they seem to more or less regularly diverge from the apex. Lateral areas : The surface ridges are radial and more pronounced than elsewhere. On the upper portion of the areas there are transverse low ri placed further apart than the former ; these ridges by bein- inter- rupted gradually pass into tubercles. The tubercles are round, distinctly smaller than in the central areas, and more scattered. Posterior valve.— With a small central umbo. Anterior an a : With concentric tubercles, as in the lateral areas. Posterior area : Similar to the anterior valve. Qirjle.__NarroWj with delicate scales, which form a minute fri at the edge. C0lolv_Greenish-white with one or two irregular reddish-brown flecks. Size.— Length, 8 mm. ; breadth, 3.."> mm. Northern 7V//.V, L«t. 35° 41' N., long. 157° 4? K.. i.. 2300 fas. /.. henthus HAD., ('hall. K.-p. xv, p. H>, t. 1. f. 1. t. 2, f. dills.— Seven in number, extending between the prominent anu> and postero-lateral angle of the foot. The gill row ifl ..n.—venth 10 LEPIDOPLEURU8. of the total length of the body, the proportion with regard to the n <>t* the foot is 1 : 4.5. Tin -y are of moderate size, the middle being the largest, slightly decreasing behind but much more so in L. n i i '.IN \rt\s Adams h. (CJpr.) Length 20, breadth 9} mill. ; divergence 90°. Korea. ( '1,,'tw, fH/if/htntu* AD. & RVE., Conch. Icon. t. 26, f. 174, 1847.— Lept<><-Itit«)i fnflf/inatus A. & R., CPR. ms. p. 4, 5. — DALL, Proc. U. t. MIIS. 1878, p. 318, 316. This specimen is an approach to Stenoplax in its outward form and the character of its girdle covering. The scales appear smooth, ami have the shape of those of Stenoplax. It has a curious general resemblance to Trachydermon albus, but the absence of insertion plat*-- at once distinguishes it. The concentric furbelowing at the sides i> variable. (Qor. from B. M. specimens.) See remarks under L. cancellatus for further distinguishing char- acters of tli is species. I.. • \ni. 1.1 •- K« ve. PI. 4, fig. 87. Shell ovate, attenuated anteriorly; terminal valves and lateral areas of the rest concentrically ridged, radiated with minute gran- uli-s central areas very finely grooved and cancellated, whitish, liga- ment horny, arenaceous (Reeve.) Habitat unknown. C. catillus Rv. Conch. Icon. t. 23, f. 159, lS47.—Leptochiton ... CPB, .UN. p. ii. Miu'ht e;i>ily IK- taken for *trnmtnens Sby. outside. Coarsely granose-1 irate, like the Mogador specimen [L. granoliratus] ; girdle gravelly. The sculpture consists of longitudinal granose lira1 upon ami radiating gltmofe lira- upon the lateral areas. No insertion plates, but the line of them is rugose. Length 9*, rgeooe 110°. Jugum rounded. (Q?r.) ii PIBOPL1 iKUS. 1 1 L. CONCINNU8 Gould. I'njif/nrnL Shell minute, reddish, elliptical, vaulted, all over punctate [ LM lose], the points arranged in radiating, nirvmi: B6rie0; lateral areas hardly elevated, longitudinally waved, l-'mut valve oretoentlC : posterior valve with an acute umbo, concentrically waved. < ,'mlle narrow, buff. (Old.) Length 8, breadth r, mill. Butural plates small, subtriangular ; jugal sinus very wide, flat ; scales of the girdle delicate. (Qpr.) Hakodadi, Japan, laminarian zone, on shells and C. (Leptochiton) concinnus GLD., Otia Conch, p. 117. — Lepto- chiton concinnus CPR. MS., p. 3. — DALL, Proc. U. S. Nat. Mu~. p. 318, 316, 1878. L. NEXUS Carpenter. Unfigured. Shell small, whitish-ashen, valves gothic-arched ; lateral areas scarcely defined; entire surface ornamented with series of sulujuad- rate granules, the series longitudinal upon the central, radiating upon the lateral areas and end valves, very close, scarcely inter- rupted. Jugum elevated, subacute; umbones inconspicuous. Mucn. conspicuous, median. Inside with strong sutural lobes and a wide plane sinus to the middle valves; insertion plates obsolete. Girdle having narrow, close, striated scales and needle-shaped, crystalline bristles here and there and around the margin. (Q?r.) Length 7s, breadth 4£ mill.; div. 90°. Catalina Island, California, 20-80 fins. Leptochiton nexus CPR., Rep. Brit. Asso. Adv. Sci. for 1863, p. 650,1864; Proc. Cal. Acad. iii, p. 212, 1866; ms. p. 2.— DAM.. Proc. U. S. Nat. Mus. 1878, p. 316, 319. A variety is prettily variegated with olive, has stronger sculpt- ure, and the valves slightly beaked. The spicules which appear on the girdle among the striated, elongated scales, are very numerous. It is curiously like the young of Ischnochiton radians. (Cpr.} See notes under L. cancellatus for comparison with that species. L. RUGATUS Carpenter, n. sp. PI. 3, figs. 67-70. Oval, rather convex, the lateral slopes nearly straight, doi-al ridge broadly arched. Front and back valves and lateral areas of the intermediate valves sculptured with excessively fine radiating striae which are feebly granose, and having well-marked, coarse, con- centric wrinkles; central areas having an equally minute sculpture ll* LEPIDOPLEUBU8, of longitudinal Bubgnuno0e striae. Macro sabcentral ami prominent. Tlit- lateral areas are slightly ra: \. bivadth 7 mill.; <1».< Santos Bay, L. C. granolirotiu, but it is much finely -culptinvd. the arch of the valves is narrower and the al areas are less stnmirly marked by concentric- wrinkles. It i-- likely that (lie following is merely the young of this, but I have not Keen able to compare typical specimens of internexus. L. i\ irpenter. Sh»-ll similar to L. nexus, but much smaller, orange colored. Valve- i. -iilarly arcuate, without jugum. Sutural plates small, triangular: sinus larger. Girdle with more solid scales, scarcely pilose, i ( >-.) Length 41, breadth .31 mill.; div. 90°. Santa Barbara, O.///Vor///'/. A. inh-rnexus CPR. MS., p. 3. L. CERGl iii \MS Haddon. PI. 1, figs. 14-17. Shell. — Minute, smooth, or with scattered minute tubercles ; the -idi- meet at an aii.irle of about 100°; sutural lamina' small, tri- anirular. Anterior valve. — Small, smooth, with scattered aborted tubercles. Int'Tinediate valves. — (V-ntral area smooth, with very faint longi- tudinal >tri;e; lateral areas scarcely discernible, with faint radial -tri:e and minute concentric interrupted ridges towards the apex, which pa>- into inconspicuous small scattered tubercles. I1 sterior valve. — With full rounded umbo, behind which is a >hall«)\\ d< presHon. Anterior area : similar to the central areas of the intermediate valves. Posterior area similar to the anterior val- (iiidlc. — Narrow, with delicate scales. < '"lor. — rniform whitish. . — Length 3, breadth !'."» mill. < iills. — Posterior, « i-ht or nine in number (Haddon.} Balfour Bay, Royal tfnunide l.\ :( .-.liirlit ._. . margin «.r the anterior valve i< semicircular, MM- posterior mai meeting ;il MII angle <'f l.'.n '. The po.-terior margin of the vnlvc is about tin- third of a circle, itfi In. nt 111:11 above a- a >traight line. The miicro is >nl.eenl ral, .-omewhat D t'orxvard than lichind. Tlit' color ot'tlic valves is a pale irray-liniwn. irre-jularK witli brown dots which are lacking at the margins, l'-a\; a paler, unicoh.i-ed /(.no. The girdle is brownish, the scales white. The length cannot be given exactly, as all the >pecinien- \\ ••!••• strongly rolled up; but the maximum length seemed to l.e 1-7, breadth of the shell 2';") of the girdle O8 mill. (/;/fr.). Leptochiton pagenstecheri PFFR., Jahrb. Hamburg. \Vi.--en- schat't lichen AnstaJten, iii Jahrgang, p. 107, t. 3, f. 3, 1 - L. ASELLU8 Spongier. PI. 3, figs. 64, 65, 66. Shell small, rather elevated, the dorsal ridge bluntly angular. Very minutely and evenly, but rather indistinctly, lirate-granulate; olive-ashen, often having longitudinal delicate pencilings of olive- green. Anterior valve very densely, minutely and evenly granulated, the granules being irregularly, but usually visibly, arranged in radi- ating rows ; the peripheral third of the valve having coarse concen- tric wrinkles. Intermediate valves have the central areas finely densely longi- tudinally granose-lirate. Lateral areas closely granose, the granules arranged in radiating rows on the lower portions, which are also wrinkled like the anterior and posterior valves. The lateral areas are separated from the central area by an inconspicuous low ridge. Posterior valve with subcentral, rather low umbo, the posterior slope concave. Interior of valves white; sutural plates small. Lofoten Is., Norway, Iceland and Greenland, *out/i to d'u/j »f Gascony. Chiton asellus SIM:N<;I.I:R, Skriv. Nat. Solsk. 17(.»7, vol. iv. j.. — LOWE, Zool. Journ. ii, p. 101, t. 5, f. 3, 4, 1825. — BROWN: DESHAYES in LAMARCK An. s. Vert. ; MII>IH-:NI><>I:I i : FORBEB <$ 1 1. \\LEY, Brit. Moll. vol. ii, p. 407, t. f>!>, f. 1, '_'. — Chiton tiiiniinn.< ( 'IIKMNIT/; WOOD; DILI.WYN. — Chiton cinereu* MONTAGU; 14 : K'I.IVI : LoYEN; JEFFREYS, Brit. Conch, vol. iii, p. 218, v. p. 108, t. 56, f. •_' : I'. Z. S. 1882, p. 668., non LINNI:. teste II \\IIY. Ip-. Lin. Conch, p. 17. — Lepioehiton cinereus GRAY, P. 1*47. p. 127, !»;* • var. white, C. "'albus " exclus.) as type of genus. — J.fjitnrhitnu nuel/unli.&A. ADAMS, (Jen. i, )>. 473. — GRAY, Guide, p. 182.— Cn:. *•* p. 2.— BALL, I'roc. T. S. Nat. Mus. 1878, p. 318. — / Lein'il<']>!' unit cinereus L., SARS., Moll. Reg. Arct.Norv. p. ll'J. t. 7. f. *.— Chiton ittandicn* 4. iv. 1 Heft. P. «;•_', 17!»7 rf. Mai. HI. xvii, p. 113. This >j>ccies is allied to L. granoliratus Cpr., but that is more t« .1. the central and lateral areas are more diverse in sculpture, and the concentric wrinkles are much stronger. In L. cancellnttt* the lateral areas are raised, which is not the case with the asellus. "Under the microscope this species can easily be separated from ;i. iixirginatus Jeffr.) by external characters. In the nnon the scales are very minute, smooth, granular, reddish and closely appressed to the girdle; in the Leptochiton they are gravel like, irregularly crowded, larger, lengthened and striated. In I, also, the valves are more beaked, especially in young shells." L. '.I:\NOI.H: \n > Carpenter, n. sp. PI. 2, figs. 47-53. Shell oval, rather h»w and regularly convex, not angulated d<>r- sally. Very finely and closely granose-lirate, the anterior and pos- terior valves, and the lateral areas of the median valves strongly c.,rnii:ati-d c.mrrntrieally. Color "ashen-orange" or fleshy-ashen, with an ill-dHim-d darker dorsal stripe. ,nt«-rinr valve, ;md the lateral areas of the intermediate valves ,11. ly radially granose, and have a number of strong concentric wrink!«>. The central areas have close fine subgranose longitud- inal lira-. The lateral areas are slightly raised. I'mho of the posterior valve somewhat in front of the middle, rather prominent ; posterior slope concave, radiately granose-lirate and strongly, irregularly, concentrically wrinkled. LBPIDOP1 i ' 1:1 -. 10 (iirdle narrow, rl<»>rly hr.-et with delicate • '. •oales, LniLrth 10, hivadth 7 mill.;
  • cayetanus Poli, Risso, Hist. Eur. Merid. iv, p. 267. — Ch. cult" Poli, JEFFR., P. Z. S. 1882, p. QQ7.—Leptochiton cuj'.'tnnu* Poli, CPR. mss. p. 7. — Holochiton cajetanus Poli, BUQUOY, DAUT/I \ i and DOLLFUS, Moll. Mar. Roussillou, i, p. 500, t. 61, f. 1-3 ; i f. 5. 16 LEPIDOPLEUBU8, In -culpture tliis sp -trikinirly different from the other and in fact from all other Chitons. The lateral areas ami front \:il , -1, the latter being compared by ater to a circular flight <»f nmndcd >irps. The Atlantic >p, cinieii^ arc always larger than those from the . the measurement* Jird given above being taken from an Ocean example, the second measurements from an Italian speci- men. It i- the i llisso's genii- Lepidopleurui. ;ion Deshayesiff/'t Carpenter, 1878. Deshayesiei/'i CAKI-IMKR mss., p. 10. — DALL, Proc. I . S. Nat. ;.. :I14; l.<: 1882, p. 286.— HADDON, 'Challenger' IV.lyplacophora, p. 9. Shdl ehm-ated: valves curved, somewhat beaked; umbo flat- tened: m> insertion plates ; sutural plates, triangular ; girdle spicu- lose. Ditli-i> from Ltochiton not only in its hairy girdle but al>o in ':itt«-m-d iimlio and its valves, which are somewhat thrown for- um d, forming a decided transition toward some of the palaeozoic forms. L. . i KV kTOH Carpenter, n. sp. PL 4, figs. 78,79, 80, 81. Shell rather elongated, whitish-ashen, planate ; dorsal ridge rounded ; umho central, flat; valves with pointed apices, all curved ; the interior .if the posterior part of each valve much scooped out. Jugal area broadly V-shaped, r. I N:i1. Mil-.. 1*7*. p. •"•IMname ami -jeiier'n- e! Dtthayetiella curvata c/ir. ,l/.sf. p. lo. This shell externally looks very niiieh like an . I "//,//, o'7, /'/<,// without the pore hunches, of \\hieh there i< no trace. The plam d oil' parts inside the apices are unusually large. (Q>r.) Genus II. IIANLKYA Gray, 1857, Hanfcya GBAY, Guide Syst. Di>t. Moll. P.. M., p. 186, type"//. debilis Gray— Chiton h«n/<-i/i Thorpe." — Hnn.leyia DAM., and Ilt/tl suppl. to Thorpe's Brit. Mar. Conch, p. _ and HAM. KY. Hist. P.rit. Moll, ii, p. 398, t. .-.lini:.. IJrit. Condi, iii, p. 215; v, p. 198, t. 55, f. s.— 5, Moll. ] . Norv. p. 109, t. 7, f. 5. — Hanleia hanleyi P.. an, Cri:. mss. p. 8. — llanleiia dcbilis GRAY, Guide, p. 186, ]x~>7. // , •";/,/ dclUls Cray, DAI.I.. PrOC. I". 8, Nat. Mns. 1*7*, p. 319. •"//(//• LUVKN, Ind. Moll., p. I'll. This spi-cii's has been reporti-d tVoin Palermo by Monterosato '.!o,,r. dr Conch. 1878, p. 147). Yar. LBY88ORUM M. Sars. PI. 4, figs. 74, 75, 7d, 77. Closely allied to //. h'tiJciii, but more than double the size, hav- ing thr -mile \vidor and thicker, spicules shorter; shell narrower, with !«•>> distinct sculpture. Pale brown, the girdle flesh-brown. jth :;t mill. fS.trs.') Bergen, Xorway, 150-200 fms. Ch. abyssoruiii >F. Sars, G. O. SARS, Moll. Reg. Arct. Norv. p. . t. 7, f. 4; t. 34, f. 3. H. MI:M.I« -AIIIA Mi-hels vV Adams. PL 4, figs. 82, 83, 84, 85. Shell oblong-oval, not much elevated, dorsal ridge obtuse, lateral elopes flattened ; ashen-white, the entire surface granulated, gran- !y crowded, forming longitudinal series, about 20 on each >id«-: lateral areas ha idly defined, irregularly granulated, the granules larger. .luirum scarcely defined, broadly vaulted. Mucro low or : al. Interior having a solid, rather acute, but scarcely fissured inser- tion plate to the anterior valve ; none upon the central and posterior valve.-. Sutiiral plates lariro, subtriangular ; sinus simple, wide, scarcely laminate. Kaves wide. Girdle wide, solid, leathery, finely Spiculate, the spicules glassy, here and there crowded; no p < Jills posterior, about \~> on each side. •i_rth 1 "», hr.-adtli 85 mill.; divergence 123°. Length 1th 15 mill.; divergence 108°. (Q?r.) Casco B,, rnnl llarhur -I. i., Inv.-rt. of Ma.s.. P.inney's Edit, p. 2(>3, f. 526.— M .. ii.. -1 1:1 ••!••]:., P. /. S. 1882? IM.MI MM IIIMM. Hi j>. <5H7.- • Hanky ia mtndicaria CPU., N. Km:. Oiitim.--, Ann. I N. II.- I: xiii, ',,. iL'l ; .J/X., ,,.!), 10.— DAI. I,, PrOC, I tfuB. 1878, p. 319. H. TROPICALffi Dull. PI. 6, figs. 12-18. Chiton about !<)•() nun. in K-n^tli and .">•() nun. in width, with the usual characters of the genus, i. e., anterior valve with an un-lit insertion plate, other valves without even the plates; hack with an angle of about 90°. Girdle (fig. 13) in the dried specimens, thin, narrow, covered with close-set, white, glassy, slender spine- • 1-n I -."> nun. in length) above, and below with similar but much shorter ones. Anterior valve with a well-marked mucro, from which proceed concentric striae of growth, and in front of which the valve is a little concave ; sculpture of little less tesselated flattened nodules radiating from the mucro, above which are irregularly distributed small, opaque, white pustular bubbles of shelly matter looking like attached grains of coral sand ; posterior valve smaller, flatter, with similar sculpture, but the pustules take on a decidedly cylindrical shape and are elongated, looking like the stalks of decapitated mushrooms; this arrangement is still more marked on the posterior lateral areas of the intermediate valves, the anterior lateral areas also exhibit (less prominently), but with an obliquely anteropos- terior radiation, while the former have it more entirely lateral from the mucrones ; dorsal areas with the tesselated sculpture alone, arranged longitudinally. Color entirely white. Sand Key, Florida, in 128 fms. Hanleyia tropicalis DALL, Bull. Mus. Comp. Zool. ix, p. 53, 1881 ; < Blake' Gastrop. p. 415, t. 26, f. 8c, 8d ; Bull. U. S. Nat. Mus. No. 37, p. 172, t. 26, f. 8c, 8d. Genus III. HEMIARTHRUM Carpenter, 1876. Hemiarthrum CPR., in Dall's Moll, of Kerguelen I., Bull. U. S. Nat. Mus. ii, 1876, p. 44. Head and tail valves having smooth, unslit insertion plates, the intermediate plates lacking them. Eaves minute. Sinus broad and spongy. Girdle solid, downy, poriferous, the lateral tufts small. Gills short. Differs from all the preceding genera in having both head and tail valves provided with insertion plates, and in the poriferous girdle. 20 HEMIARTH1MM. II. BBTULOSUH Carpenter. PL 5, figs. 89-100; 1-8. The color of the shell is a uniform warm dark brown, and the girdle is chestnut brown, with a pale crenulated border round the margin of tin- valves. In each of the dark triangular bays between tin- valve- i- a .-mail tuft of short white spicular scales, and there are imilar tufts round the anterior border of the first valve. The anterior and po>trrior valves and the lateral areas of the inter- mediate valves are marked by concentric lines of growth, otherwise the latter are scarcely discernible. The jugum is very gently rounded, so that the pleura are slightly depressed. The unslit in- sertion plate of the anterior and posterior valves is shown in figs. 90, 94, and 4. ~>, (\. The girdle (fig. 98) is thick and soft, with a minute scattered scales. There is a distinct fringe of reddish brown elongated striated scales round the margin. The scales forming the tufts are stout, and white in color. Carpenter describes the anterior tufts as about four in number; in my specimen there are -i\ anterior tufts. Evidently Carpenter was not quite satisfied on this point, as in all other Chitons which possess tufts, only four are p resent; and, consequently, that number might be expected to occur in this species also. The head lappets are rather large, and the anus is on a large rounded papilla. The longitudinal band on the under side of the girdle (veil of Carpenter) is produced into flaps at the po.-terior extremity. Tin- Lrill> rjil. .">, figs. 1, 99, 100, 7), form a short posterior row, and appear to be about six in number; they decrease in size anttr- iorly. Length '.) mm. ; breadth 4 mm. ; side of valves meet at an angle of about 115°. (Haddon.) Length i:1,, width 7 mill. (Q?r.) Kerguelen Island, on stones at low water (Kidder); and Royal Sound on shore (' Challenger ') ; South Georgia (Pffr). Hemi'irthrum setn/nsnm CARPENTER 1/&, p. 13. — DALL, Bull. U. it. Mus. ii, l>7'i. p. 44.— HADDON,' Challenger 'Poly placophora, p. 11. t. 1. f. 1 : t. L'. i'. 4a-l. — MAI.-TKNS and PFKI -FKK, Jahrb. der llambnrgischen Wissenschaftlichen Austalten iii, p. ]08, t. .'), f. 4, 1886, The specimens from S. Georgia were much eroded ; they meas- : about s-ll mill., and were when alive, ''brown-black almost blaek. " One of these is figured on pi. 5, figs. 1, 2, 3. MI< HOI-LAX. LM This shell, externally, resembles < in r.iMM,, Miss. Sci. du ( 'aj> Horn, vi, /ool., j.. ' 1 :; I l-l.",, L889.— CA&m L., FISCHER, Manual, p. 879. Chitons in which all of the valves pOMeta insertion-plates -lit into teeth; the insertion-plate of the tail valve similar to that of the head valve. Eaves developed. The conclusion has been forced upon me that the- three divisions B, Ischnoidea, C, Lophyroidea, D, Acanthoidea of Carpenter's arrangement cannot be separated by sufficiently definite characters to give them the rank of families. The Ischnoidea blend with the Lophyroidea through certain species of Chcetopleura, Tonicella and Tonicia ; and the connection with those Acanthoidea having Isch- noid insertion plates is even closer. It is by no means certain that the Acanthoidea constitute a natural group; the portion having pectinated insertion plates may prove more closely allied to the true Chitons (Lophyroidea), whilst those with sharp, smooth inser- tion plates would hold a like relation to the Ischnoidea. It is, in fact, not an easy matter to decide whether such genera as Callisto- chiton and Pallochiton belong to the Ischnoid or the Acanthoid series, Carpenter referring them to the former, whilst my own stud- ies cause me to place them in the last named group. In the present work I have concluded to recognize Carpenter's three divisions as subfamilies, believing it better to retain a classifi- cation admitted to be faulty than to institute radical changes which I am at present unable to place upon an indisputable basis. The regular Chitons having slit insertion plates may therefore be divided into the following three Subfamilies : Subfamily ISCHNOCHITONIN^E. Insertion plates smooth or nearly so, sharp, slit into teeth, which project outward on all of the valves. Subfamily CHITONINJE. Insertion plates finely pectinated, blunt- edged, the teeth all projecting outward. Subfamily ACAXTHOPLEURIN^E. Insertion plates smooth and acute, or pectinated and obtuse ; teeth of the posterior valve dis- tinctly directed forward, not outward. (23) 24 Subfamily ISCHNOCHITONIN^E. Ischnoidea CPR., Table of Regular Chitons, and DALL, Proc. I. at. Mus. l*si>. p. 283, (in 'part; < Jenera 19-24 excluded).— hchruH-hitonnlt DALL, ' Blake ' (iastmp. p. 4M, 1889. I have above given some of the reasons which induce me to con- sider this group as a subfamily rather than a family. I am wholly disposed to believe that the subfamily as here constituted, is rather artificial ; and some of the genera may require consolidation. The relation existing between Cluztopleura and Tonicia especially calls tor investigation ; and there are some forms (section Cyanoplax) which seem to bridge the gap between Chcetopleura and Tonicella. Synopsis of Genera of Ischnochitonince. Genus V. LEPTOPLAX Cpr. Valves thin, partly immersed in the thin smooth girdle; insertion plates acute, having jew slits. Umbo of posterior valve median. Genus VI. SPOXGIOCHITON Cpr. Valves partly Immersed. Insertion plates acute; umbo of pos- terior valve median. Girdle spongy, having chaffy scales and hair- lets, and produced forward. Genus VII. CH^ETOPLEUPvA Shutthv. Valves exposed; insertion plates smoother obsoletely grooved : X. CALLOCIIIToN Valves rxp<>srd : insertion plates cut into num< ill rising from very *IHHHJ\J COVCS, the teeth more or les~ /mftressed at tin- out- side edges. Sutural-platet continuous acron the vr,r>/ nhullmr m*',/;,/,, x/;//(.<. <;irdle typically covered with fine eompaet diamond -haped scales : hut iii the suhgnms Stereochiton sparsely downv, fV«-«jinMit.Iv naked l»y erosion. Genus XI, ISCHNOCHITON Gray. Valves exposed ; insertion phites sharp, smooth ; eaves not spongy, or rarely so. Umbo of posterior valve varying from pos- terior to anterior. Girdle covered with imbricating scales. Genus V. LEPTOPLAX Carpenter, 1882. Leptoplax CPR. MS., and Table of Regular Chitons, 1871. — DA i.i.. Proc. U. S. Nat. Mus. 1882, p. 286. Type C. codrctatus Sby. Valves thin, partly immersed in the thin, smooth girdle. Inser- tion plates acute, with few slits, but regular. Sinus scarcely toothed ; mucro median. (Q?r.) The prominent characters of this genus are, (1) valves partly covered by a thin extension of the girdle, (2) girdle smooth, as in Tonicella, (3) insertion plates long, with few slits. The gills are unknown. L. COARCTATUS Sowerby. PL 11, figs. 38, 39. Shell elongated, very delicate, little elevated, the dorsal ridge acute ; greenish-ashen or reddish-olive. Valves of the normal form, but two-thirds covered by a thin cuticle continued from the girdle. Exposed portion of the valves flask-shaped, the jugular area smooth, subelevated, having longitudinal rows of points; central areas and end valves having large pustules, close and somewhat radiately placed, about 20 on each side in a young specimen, 100 in an adult : lateral areas scarcely defined ; mucro slightly behind the center, rather elevated. Interior: Plates of insertion very long, tinted, here and there delicately striated outside. Slits small, in the posterior valve 6, posteriorly situated; central valves 1, anterior valves 4, having shallow grooves running up to the cave-. Sinus 26 SPONGIOCHITOX. moderate, indented by the sculpture of the outside. Girdle very thin, ratlin- expanded, smooth. (Cpr.) Length 131, breadth 71 mill.; divergence 120°. Island of Bohol, Philippines- Chiton eoarctatut SOWKKHV. 1*. /. S. 1841, p. 62. — REEVE, Conch. Icon., t. 20, f. 127. — Leptoplax conrdatus CPR. MS., and Lept. rubrotinrt'i ( JpR. -VX. <>/hn. This mi.irht he regarded as an extremely -delicate Katheriua, but that the valves are thrown forward and the tail-plate is Ischnochitonoid rather than Mopaloid. It differs from Fannia as Ischnochiton does from Chiton, in the extreme thinness and general smoothness of the sharp teeth and in the non-dentition of the sinus. I have seen no other regular Chiton in which the insertion plates are tinted, the head valve having only four slits, and the tail valve with so long a lamina, unh'ssured, at the anterior sides. (Cjpr.) Carpenter at first described this form under the name rubrotincta but he discovered its identity with C. coarctatus by an examination of the type of the latter. The sculpture varies much ; sometimes there are a few large grains, sometimes many smaller ones. Genus VI. SPONGIOCHITON Carpenter. Spongiochiton CPR., Table of Regular Chitons, 1873. — DALL, Proc. U. S. Nat. Mus. 1882, p. 272, 283, 286, 289, 290. Valves partly immersed ; insertion plates acute, Ischnoid ; sinus large, smooth ; raucro median, flat ; girdle spongy, produced forward. S. PRODUCTUS Carpenter, n. sp. Shell oval, the valves immersed two-fifths of their width ; exposed portion rubicund, flat, the jugum arcuate, paler. Lateral areas scarcely defined. Entire surface sculptured with prominent pebbles, worn at the jugum. Mucro submedian, flat. Interior : posterior valve with 6, central valve 1, anterior valve 5 slits; teeth long, acute, scarcely serrate; sinus wide, smooth, extremely deep. Eaves narrow, scarcely grooved. Girdle produced in front, spongy, sparsely covered with chaffy scales and translucent hairlets. Length 25, breadth 161 mill. ; divergence 130°. (Q>r.) New Zealand (Mus. Cum. no. 50). ( ill TOPLS1 i: \. -7 This very peculiar shell rescmUes .Mopalia Mainvillei in mantle and inner.); and Nuttallina in tin- l«»n.Lr, Mnooth plate.-, -eparaN d l.y a d.-ep, not laminated sinn<. Tin- side slils how, and deep instead of duplicate and angular, as in thai rior plates are not tin-own forward nor waved as in Mopalia. I^av- \i\^ out of view the anterior prolongation of the mantle, which \» a variable character even anioni: Mopalia, it may be regarded as a partially covered Tonicella. The slits are abnormally few, as in Leptoplax. But for the characters of the tail plate I should have considered it intermediate between Mopalia and Katherina. (< Genus VII. CH^TOPLEURA Shuttleworth, l*f>3. Chcctopleura SHUTTLW., Diagn. neuer Moll. no. 4, iiber den Ban der Chitoniden, etc., in Bern. Mittheil. p. 66, June, 18~>3 (~ Acan- thopleuraGray, ex parte). — Choetopleura CPR. MS. and DALL, 1'roc. U. S. Nat. Mus. 1878, p. 329, type C. peruviana Lam. — Acantko- pleura, GRAY, Guide Moll. B. M. p. 183. Valves as in Ischnochiton ; eaves solid ; girdle leathery, more or less hairy ; gills extending almost or entirely to the front end of the foot. The present group seems to me to stand naturally on the confines of the Ischnochitonoid series, having decided relations to the true Chitons and especially to Tonicia. Carpenter made a subgenus, Maugerella, under Chcetoplcura, for a Radsioid Californian form, which I have excluded from the genus, as its affinities are with the Radsioid Ischnochitons. The following able discussion of this genus is from Carpenter's MS. : Shuttleworth, in distinguishing this genus from Acanthopleura by the mantle characters only, does not seem to have observed the co- ordinate differences in the hind valve and the insertion plates. Messrs Adams united to this genus Eudoxochiton and Craspedo- chiton which do not belong to the same section. Gray, in his " Guide," p. 183, ignores the genera of Shuttleworth, but preserves the distinction between Chsetopleura and Acanthopleura. Most unfortunately, however, he chooses to keep the name Acanthopleura for Chsetopleura of Shuttleworth and Add., and makes a fresh name Maugeria for the restricted Acanthopleura of Shuttleworth and Add. Even if Shuttleworth had been unwise in his mode of division, he would have been entitled to precedence ; but fortunately he kept Acanthopleura for the first section of Guilding's group, 28 < II.V.KTI.Kt i: \. .Jouni. v, p. 28, represented by Chiton spin osus 8by, The • Indian -pecies belongini: to this section (A. picea) must have been familiar to him and u'iven ri>e to the " / diairno>i>. with which < 'iKctoj.leura does not accord. The -•ntcd l»v < '. peruvianus 1'onns only tlie sixtli among seven sections into which Guilding divided his genus. Bhottleworth and Adams place the hairy chitons, in Chsetopleura and those with shelly l>ristle> in Acanthopleiira. The distinction is obvious as between peruviana and picea, but not so in t lie cast' of many -pecies \\lien the bristles are corneous but With more or len of shelly matter in their substance. There are also ma; | in which the hairs are shortened and flattened into chaffy scales and others in which hairs grow irregularly in the midst of a spongy or chaffy mass. Gray, moreover, assigns "shelly t-» the peruviana group and " shelly spines or bristles " to tin- picea jrroup. Tothefir-t. however, are assigned thin, to the second thick valves. Both are described as having the insertion plate- pectinated ; but as being " regular well developed " in peru- viana, hut "narrow, rather irregular " in picea. This last results from what seem- to me the essential difference. Acanthopleiira is hunch-hacked on the tail plate, with the insertion plates thrown for- ; and L'r-'ovcil outside ; while Chretopleura has the normal tail plate of Chiton and Ischnochiton and agrees with the latter genus in having the insertion plates not pectinated and nearly smooth. The transition forms from the densely pilose peruviana to the smooth mantle of Tonicella are so gradual that the latter might rank as a subgenus under Chsetopleura were it not that the gills in tin- ircmis are represented as elongate. (Cpr.) < 'h;etopleura should be compared with the Lophyroid genus Ton- icia, which has similar ambient gills and solid eaves, and frequently has th- t--r i h scarcely more pectinated than in the larger Chieto- plcuras. The genus consists of several groups of species. (1) Typical ;h«-r large, and having very delicate sculpture; and (2) Group of C.gemmea, having the lateral areas strongly raised and coarsely sculptured, the central areas also sculptured. (1). Urniij, of C. n \I\N\ Lamarck, IM. rj, ii^. 42-46. • •ssed, dull a.-h colored, the girdle clothed with long, Stifi*. crUp black hair, a fringe of which also projects from each ' : 'i .1 i i: \. suture. The valves MIT iniiiiitclv .-culpmred \vitli very minute granules in lin»-> which diverge -li-htly at the jiiiriini, more upon tin1 >ide- ol' the central area-, divaricate on tlie horder ln-t central and lateral areas, and an- radiating upon the liiti-ral ai and tenninal valves. The iimho of the tail valve i> low, -omeuhal anterior. Interior white with a brown stain at the back edire of each valv«-. Anterior valve having lon^- insertion plates which are di.-tinctlv crennlated outside, ami have !)-!() slits, central valves with 1 -lit, post, valve with 7~V slits. Sutural plates very broad, connected across the sinus hy a narrow plate; eaves narrow, .-hort, Length 38, breadth 20 mill. Lima, Peru; Chili; to Oij>r Chiton periivianus LMK., An. s. Vert, vi, p. 321 ; ed. Dh., vii, p. 491. — Barnes, Amer. Jour. Sci. vii, p. 10, t. 3, f. 2. — SOWB., Conch. Illustr. f. 44. — KI:I:\ i: Conch. Icon. f. 50. — Chaetopleura peruviana Lm., SHUTTLW., Diagn. n. Moll. nr. 4, p. 07.— \{<>< \\ i.m; ., Moll. Cap Horn, p. 1-^). — Acanthopleura peruviana Lm., TAP. CAN., Viag. Magenta, p. 77. This form is readily known by its girdle covering and sutural fringes of long black hairs. The sutural plates are strongly devel- oped, slightly recalling Leptoplax. The hair is crisp and coarse, like that of a horse's tail. The gills extend forward to the head. C. HENNAHI Gray. PI. 12, figs. 47, 48, 49 ; pi. 17, fig. 39. Shell oval, rather depressed, dorsal ridge obtuse, side slopes nearly straight. Color variable, but generally either reddish-brown marked with red, or greenish-white marked with brown ; surface smooth to the naked eye. Girdle leathery, covered with short hairs, which may readily be rubbed off. The median valves are about four times as wide as long; the lateral areas are only weakly indicated ; the tail valve is depre>- d, with the slightly prominent umbo in front of the middle, the pos- terior slope concave. The sculpture consists of closely beaded ti in- separated threads, which are longitudinal on the central, radiating on the lateral areas and end valves ; under this may be seen an excessively fine, close shagreening of the whole surface. Inside white, each valve marked with brown under the beaks. Sutural plates of equal width from the outer angle of the valve to the rather shallow sinus. Ant. valve having 13, central valves 1. po>t. 30 CEJSTOPLBURA. valve !•"> >lits, (i 'arpenter Liives : ant. v. 10, centr. 1, post. 9-12 slits). Teeth sharp, those of the head valve prominently grooved outside. Eaves narrow and short, grooved just above the teeth, not spongy. Girdle .pi. 17, fig. 39) granulated, sparsely clothed with stiff white spinelet-. ( Jills continuous to the head, as in C. pernviana. \, Qgth 13, l-readth 28 mill. Callao Peru, on Pectens, in 5-7 fms- Ch. henwihi .— RKKVI:. ( ouch. Icon. t. 7, f. 37, and pi. 23, lower mitral lLrure. This >pecies is closely allied to C. peruviana in form of the valves and sculpture. The girdle hairs are short, deciduous, and when retained they are disposed to lie in bunches. The front teeth are decidedly grooved outside, in old specimens resembling lafulva. i. ii i- Reeve. PI. 14, fig. 80. Shell ovate, smooth or very closely marked throughout with minute raised dots ; lateral areas faintly radiately grooved. Red- dish chocolate-brown, unspotted ; ligament horny, beset with very short, hard bristles (Rve.) Habitat unknown. f'hHon »<>!>;iis "Gray," REEVE, Conch. Icon. t. 21, f. 139, May, 1847. Not Chiton nobilis Gray. — Chcetopleura nobilis Rv., CPR. m Carpenter further describes the type specimen: mucro median little elevated : valves rounded at the sides. Interior: post, valve with J), ant. 11, centr. 1 slit. Teeth acute; eaves small; sinus small, deep, planate, smooth. Girdle leathery, pale brown, sparsely and irrer i i.i i: \. :;i (Vntral area- having sul.parallel or slightly radiating lin- granules, about L'U on cadi side. Lateral area- -eareely «|eline<|, having about 1<> irregular radiating line-, tin- ant. va! post, valve 40 such lines. Kntiiv siirlaee nio-t niiniitely pun. This species must not l)e mistaken for the e.r/crn?'•) ill, :;. alt. , mill; divergence 110°. if/an, on Spondylus calcil'er. Lepidopleurus bntlaliis Cri:., Ma/at. Catal. p. 195. — Chtttojil* lnll» ' !/>'.— L. hnll'itu* i'"r. (•<>/<• Iferus CPR., 1. c. p. 196. One fresh specimen (><>me\vliat crushed in extraction) and a few perfe i were found of this species, which is characterized by the very >t mil-: row <>f tubercles, (like pebbles) which lie on the diagonal line; by the rows of somewhat strong tubercles on the central area, rmminir perpendicularly from the diagonal towards the juguni and the granules over the whole surface, somewhat corru- gated on the juguni. The internal plates of all the valves have an :ial projection from the outer surface, as in L. .«niomewhat rounded. Posterior valve depressed, excavated, the mucro >mall. superior; jugal and lateral areas indistinct : sur- with granules and ornamented with small close points. Sutural plates large, curved; sinus tlat : insertion plates acute, the intermediate valves with 1, terminal valves l!) slits. Girdle hairy, -pines .-mall, erect, tlat. • adth 3i,alt. 1 mill.; divergence 110°. it Ian, ( ii i i-.ri.i i i: \. .' l,t'i>i<1»i>l>'iirn.< l»,inii enter unites C. teabrimhus Sowl). pi. \'l. • •I aii.l !.«•/, nix'/ufon }>tyle of sculpture is the same as in C. gemmea, but the shell is much broader than in that species. Var. r i :. \SINATA Cpr. lihir to jHir'i/lefn, but vivid green; lateral areas irregularly ornamented with series of tubercles. Cape St. Lucas. Var. « "i.i MI;II NMS Sowerby. PI. 12, figs. 51, 52. Shell ovate, a little depressed, ashen ; end valves and lateral MPBAS --parsely gnumlote; Central areas longitudinally //*MSowi:.. P. /.S.I 832, p. 58; Conch. Illustr. f. 15.— L'I.I.VI . Conch, leuii. f. 82. — Clwtopleura columbiensis Sby. CPR., m§. Carpenter says: Mucro slightly in front of the middle, sul>- planate, the posterior part exeiirved. Interior: posterior valve with *. anterior valve !), central 1 >lit. Teeth obtuse, scarcely roughened; eaves large; sinus narrow, moderately deep. Girdle leathery, with a f.-w corneous hairlets. . . . One of Colonel Jewett's specimens is of a uniform dark chocolate color, but parts of some ,,f the valve- are of a variegated olive. Of another specimen ( 'pr. writes: One specimen of the wiliri- culus type. Girdle finely hairy. K'.d. with dark girdle. On each » ii i POP1 i i i: \. of the central RFCM llieiv an- l»i tinr row- of h»-ads nnt developed ; jugular araai not defined ; -idr areai u ith in larly >cattetvd grains. Mucro central, d«-pi .--( •", 58. Shell oblong, brown ; back carinatcd ; front valve and lateral areas of the intermediate valves radiutel}' granulate; central treat longitudinally granulose-striate. Length 22 mill. (Orb.) 9 Bay of San Bias, Patay<> Chiton isabellei ORB., Voy. dans 1'Amer. Mr rid. p. 488, t. «;:>, f. 14-1!). — Tonicia isabellei ROCHEBR., Cap Horn, p. 138. — Chceto- pleura isabellei CPR. MS. Allied, by its granulated strife, to C. peruvianus, but narrower, more carinated, the girdle smooth. ( Orb.*) The gills are figured as continuing almost to the front end of the foot. In the absence of any information regarding the insertion plates it is impossible to say whether this species is a Tmnriit or a Ckcetopleura ; if the latter, the girdle is probably not truly smooth. In sculpture it seems near to columbiensis and its allies. C. DIEFFENBACHII Reeve. PI. 13, figs. 65, 66. Shell somewhat elongately ovate ; valves covered with very min- ute raised dots; lateral areas scarcely raised ; posterior valve umho- nated ; variegated with red, green and yellow ; ligament horny, arenaceous. (Rve.) Newcastle. A u.r having black patches at the sides or on the ridge (sometimes red or purple 36 < I LF/TOPLEURA. in Southern specimens); carinated, the side-slopes nearly straight; central areas having headed threads, lateral areas and end valves havin.ir numerous scattered pustules. The lateral areas are distinctly defined, raised, and bear numer- ous erect rounded pustules, irregularly scattered, not arranged in rows. The end valves have the same sculpture, but the pustules are more crowded. The central areas have minutely beaded longi- tudinal thivads, f'r«»m 15 to 20 on each side. The umbo of the pos- terior valve is in front of the middle, and rendered slightly pro- jecting by the concavity of the slope back of it. The interior is white or stained with leaden in places. The sutural plates are rounded ; sinus moderate but angular. Slits of anterior valve 11, central valves 1, posterior valve 9-11. Teeth slightly crenulated ; eaves short, solid. Girdle narrow, bearing sparsely scattered, transparent, short bain. Gills extending almost to the forward end of the foot, 24 branchiae on each side. Length 17, breadth 10 mill. Length 16, breadth 12 mill. Cape Cod, Massachusetts, to Florida. Chiton apiculatus SAY, Amer. Conch., edit. Binney, p. 231. — S,,wi:.. Conch. Illustr. f. 140.— DsKAY, Moll. N. Y. p. 164, t. 10, f. 201, 202.— GOULD, Invert, of Mass. (edit. Binney), p. 258, f. 522. — Chcetopleura apiculata Say, CPR. Ann. Mag. N. H. (4), xiii, p. 120.— DALL, Proc. U. S. Nat. Mus. 1882, p. 410 ; Bull. 37, U. S. Nat. Mus., p. 172, t. 51, f. 10. — Chiton labeculatus KEEVE, Conch. Icon. t. 18, f. 108. The tubercles of the lateral areas and end valves of this species show a lack of arrangement into radiating rows, which will readily distinguish this from other species. It i> ijuitc commonly distributed along the Atlantic coast of the Tinted States from Nantucket to Florida, and has also been reported from Haiti. The North, in examples are generally buff or ash colored, some- times with patches of black; but in a suite before me from Marco, Florida, one specimen is scarlet and another purplish-pink. These southern examples, whilst agree inir with the typical form in sculp- , are smaller and comparatively narrower. (Figs. 78, 79.) A specimen from Angfaeea, New Jersey, baa the lateral areas and < ii BTOPLE1 i: \- end valves pink, the central areas Imll'. :in. M'1—i'hitnn segmentatus REEVE, Conch. Icon. t. 23, .. — / 'It if on (Chcelopleura) asper SHUTTLW., Jour, de Conchyl. 1856, p. 169. Tli is species is much elongated, about twice as long as broad- The sculpture of the end valves and lateral areas consists of coaix -. nodulous ribs, which are quite unlike the clear-cut pustules of C. meet, etc. Young specimens have only two or three nodulous ribs on the lateral areas. The C. segmentatus of Reeve (pi. 13, figs. 61, 62) differs in no way from the type. C. SPINULOSA Gray. PL 13, figs. 63, 64. Shell ashen, partially tessellated with dark and light at the sutures, and stained with brown on some of the jugular areas. Jugum very acute, elevated. Mucro median, not much raised, the posterior slope very concave. Jugal area not distinct; central areas having about 22 rows of very fine granules on each side of the otherwise smooth areas ; lateral areas much raised, having about 10 rows of radiating grains, separate, sparse; grains very irregular and sparse on terminal valves. Interior: Anterior valve with 10, central valves 1, posterior valve 9 slits. Teeth not very sharp but Ischnoid, the posterior slightly niLrulose. Sinus smooth, channelled, broad, deep, the cting jugular sculpture of the outside giving a faint appear- ance of denticulation. Eaves moderate, not spongy. Interior whitish, with two rays of chestnut. Length 31, breadth 15* mill. Rio Janeiro. Ch'r nlosus GRAY, Spicil. Zool. p. 6, t. 6, f. 7, 7a. — Sowb., Conch. 111. f. 84, 84a.— REEVE, Conch. Icon. t. 27, f. 90.— Chceto- •a CI-R., MS. It is doubtful whether the C. spinulom of Sowerby, Reeve and Carpenter is the same as the form originally so named by Gray. Carpenter's description, given above, is drawn from a single speci- men, which apparently served Reeve for his illustration. This specimen i- much injured, having lost its girdle, and some of the . 1 1.1 K.l'l.l IRA. 89 valves ami teeth an- broken. Tin- ii.L'im-s ln-rr- -/iven an- from Reeve. C.*8owi-:i:uiANA Reeve. PI. 13, figs. 67, 68. Shell <»hlon.i:-ovatr, valves having the lateral areas (•••ii-pieuously elevated, granoaely ridged throughout, riders of tin- central areas much tiner. Dull yellowish-brown, with a triangular \vhiti.-h along the umbonial summit of each valve. Ligament hornv. CRw.) Rio Janeiro. Chiton janeirensis Gray, REEVE, Conch. Icon. t. !;">, f. 80. — C. sowerbianus REEVE, /. c., in note under species No. 116, May, 1847. — Sowerbyi REEVE, /. c., expl. of pi., detail of sculpture, sp. 80. — Sower by anus REEVE, I. c., index to Chiton. Carpenter says : Seems to me a coarse var. of spinulosa Gray. Rio Janeiro. Very like apiculata, but with more swelling side areas. The sinus represented in the sculptured figure of Reeve is only the part left after the swelling of the sides. With this impression, I did not think it necessary to examine the single specimen in Cum- ing's collection; but on further examination I thought it might be a distinct species and described it thus : Valves arched ; jugum rather rounded ; jugular area finely striate. Central areas having about 18 nearly parallel ribs on each side, the interstices decussated between the ribs, which are sharp (not in necklaces). Lateral areas swelling, with 6 to 8 very close rows of coarse granules, inter- calating, and no spaces between. In the end valves they go into close radiating rows. Mucro in front of the middle, depressed, the slope behind it very concave. Girdle with very few scattered hairs. Interior: Anterior valve with 9, central 1, posterior 8 slits; teeth sharp, normal ; eaves conspicuous, rugulose, but not spongy. Sinus moderate, sharp, deep, channelled. Length 26£, breadth 133 mill. C. ARMILLATA Carpenter, n. sp. Unfigured. Shell subelongate, elevated, the jugum acute; mucro a little in front of the middle; reddish-brown, maculated with darker. Valves quadrate, scarcely apicate; jugal area scarcely defined; central areas having 14 to 20 lines of small granules on each side, the interstices flat. Lateral areas scarcely elevated, having sub- radiating, distant, sparse granules; entire surface nearly smooth, very minutely punctulate and striatulate under a lens. Interior: 4U TONICELLA. Posterior valve with 9, anterior 9, central 1 slit. Teeth acute ; eaves conspicuous ; -inns narrow, deep, smooth. Girdle leathery, minuU'ly dowpy-ecaled and having occasional delicate, corneous hair*. Opr.) Length 25, breadth 11 1 mill.; divergence 100°. Is. Gorriti (Mus. Cum. No. 34). One of the specimens is light colored on the jugum of each valve, with a triangular spot. (Q/r.) Genus VIII. TONICELLA Carpenter, 1873. Tonicella CPR., Bull. Essex Inst. v, p. 154, 1873, type C. marmo- reus Fabr.— DAI.I, IVoc. U.S. Nat. Mus. 1878, p. 324.— Tonin.i, in part of (iK.vv, ADAMS, et at. — Boreochiton, (part) SARS, Moll. Reg. Arct. N..rv. p. 116, 1878. Valves, sutural plates sinus and teeth as in Ischnochiton, but the • are spongy ; girdle as in Tonicia, leathery, smooth or nearly so. Gills extending forward from two-thirds to three-fourths the length of the foot. Distribution, Northern Atlantic and Northern Pacific shores. This irrouj) differs from Trachydermon, Callochiton, Ischnochiton, Ckitniileurn, etc., in its naked, scale-less girdle ; from Stereochit.m in having a single slit in the median insertion plates. It differs from T»n iria, to which genus the species of Tonicella were formerly referred, in the non-pectinated insertion plates, spongy eaves and shorter gills. The surface of the valves is smooth, or evenly microscopically granulated. The essential differences between Tonicella and Chtptopleura seem to !»«• bridled by several species which are intermediate in charac- ters of gills, girdle or both. The former should perhaps rank as a subgenus rather than a genus, as the pattern of sculpturing of the valves, shorter gills and spongy eaves are about all there is to sep- arate the two groups. Under Tonicella, as a subgenus, I include the peculiar type Cyano- pro posed for the reception of the C. hartwegiiCpr. The genus will therefore be divided thus: Suhgenus TONMT:I.I.A s. s. Teeth rather long; valves nearly smooth ; gills shorter than the Subgenus CYANOPLAX Pils. (h stumpy, bi- or tri-loh<-d ; valves granulated; gills ambient. rONIOBl 11 TONIOKLUI < '\>r. T. M\I:M<>KI:A Fahrieius. 1M. 10, fiir- s L5, Shell oblong or uvul, I'levah'd. ratln-r acntclv angular; hull', closely speckled and maculated with -lark n-d. as in Trl> ruhcr. Surface denttly, microscopically granulated, but apparently smooth. Lateral areas not distinct. Valves beaked, \im\tn «.f pos- terior valve slightly prominent, central. Interior rose tinted; anterior valve with 8-10, median valves 1, posterior valve 8-9 slits. Sutural plates broad, rounded; >irms deep, angular. (Jirdle leathery, nude. The gill rows extend forward three-quarters the length of the foot, each containing 20-25 brand) in-. Length 40, breadth 24 mill. Length 27, breadth 16 mill. North Atlantic : Massachusetts Bay to Greenland; Holland to Ireland and northward. North Pacific: Aleutian Islands and Japan. Chiton marmoreus FABR., Faun. Gronl. p. 420, 1780. — FORBES & HANLEY, Hist. Brit. Moll, ii, p. 414, t. 58, f . 2 ; t. 59, f. 4.— JEFFREYS, Brit. Conch, iii, p. 227 ; v, p. 199, t. 56, f. 7. — Chiton, (Tonicia) marmoreus Fabr. Smith, Ann. and Mag. N. H. (4) xx, p. 139 (Franklyn Pierce Bay, Greenland). — Tonicella marmorea Fabr. CPR., Bull. Essex Inst. v, p. 154, 1873 ; Ann. Mag. N. Hist. (4) xiii, p. 121.— BALL, I c., vi, p. 124 (anat.) ; Proc. U. S. Nat. Mus. 1878, p. 324.— Chiton ruber SPENGLER, Skrift. Nat. Selsk. iv, p. 92, not of Linne. — Chiton hvvigatus FLEMING, Edinb. Encyc. p. 113, t. vii ; Brit. Anim. p. 290.— REEVE, Conch. Icon. t. 27, f. 179. — / Chiton punctatus STROM, (teste JEFFR.) Acta Nidr. iii, p. 433, t. 6, f. 14.— Chiton latus LOWE, Zool. Journ. ii, p. 103, t. 5, f. 6, 7.— SOWB., Conchol. Illustr. f. 113. — Chiton fulminatus COUTH., Bost. Journ. Nat. Hist, ii, p. 80, t. 3, f. 19. — GOULD, Invert. Mass, i, p. 14*, f. 3. — Chiton pictus BEAN, in Thorpe's Brit. Mar. Conch, p. 264. — Chiton flemingius LEACH, Moll. (Jt. Brit. p. 230. — Boreo- ch'doH marmoreus Fabr. SARS, Moll. Reg. Arct. Norv. p. 116, t. 8, f. 3. This species has very much the color pattern of C. ruber, Imt may readily be distinguished by its nude, leathery girdle. Sars was evidently led by this superficial resemblance to create his genus •IL' TONICELI A. Boreochiton for the two forms. The Greenland and East American s|M arc more elevated and generally larger than the British form, which might retain the varietal name latus Lowe. Middendorff found the number of slits variable in his specimens fn>m the White Sea and the Arctic coast of Russian Lapland, the anterior valve having 5 to 7, posterior valve 6 to 9 slits. T. SUBMARMOREA Middendorff. PI. 10, figs. 16-24. Shell oval, rather depressed, rather smooth and shining, the entire sui face seen under a lens to be very minutely, regularly and closely •//•/». Lateral areas scarcely distinct, slightly swollen. Color rosy or yellowish-white, closely painted with spots and flames of red. Interior rose colored ; terminal valves each with five slits. < iirdle smooth, shining, yellow or brown. Uranchia' median, consisting of about 24 plumes. Length 38, breadth 24, alt. 12-13 mill. Japan, Okhotsk Sea ; Aleutian Is. to Sitka and Fuca Strait. C. submarmoreus MIDD., Bull. Acad. Sci. St. Petersb. iv, 1846 ; Mai. Ross, i, p. 98 ; Sib. Reise. p. 178, t. 14, f. 7-10 ; t. 15, f. 7, 8. — Tonlrcll'i xnbmarmorea Midd., DALL, Proc. U. S. Nat. Mus. 1878, p. 296, t. I, f. 7 ; p. 327 ; I. c. 1886, p. 210.— Chiton insignis REKVK, Conch. Icon. t. 22? f. 148, 1847. This species is readily distinguished from T. lineata by its micro- scopic granulation ; from T. marmorea by its more depressed shell, different color-pattern, etc. T. MM: A i A Wood. PI. 11, figs. 25-28. Shell oblong, rather low, roundly arched or subcarinated. Sur- face smooth, shining, ground color light reddish. End valves con- centrically marked with black-brown lines bordered above with white, intermediate valves having similarly colored longitudi- nal lines, sloping obliquely backward, the ridge or jugum of each valv. havinir a light triangle with a narrower dark one in the mid- dl«- on some valves. Occasionally some valves are wholly dark brown, unmarked. Lateral areas scarcely raised ; umbo of posterior valve in front of the middle. Interior white, more or less tinged with rose color. Sutnral plates broad, rounded ; sinus deep and angular. Anterior valve with 8-10, median 1, posterior valve 8-10 slits. Teeth short, espe- TONH i;u.\. 43 cially in the p(»terior valve, and blunt, in adult- dceidedly cn-ini- lated at the tips and obsoletely fissured ouf.-ide. I :i:ill. (Jirdk' leathery, apparently smooth and nude, brown in dried specimens. Gills extending forward two-thirds the, length of the foot, com- posed of 27 branch ire cadi. Length :>7, breadth 20 mill. Length 30, breadth 15 mill. ; divergence 120°. From Bering Strait southwestward to the Okhotsk Sea and Japan, southeastward to the Bay of Monterey, California. Aleutian Is. Chiton lineatus WOOD, General Conchology p. 15, t. 2, f. 1 1815— MIDD., Mai. Ross, i, p. 109, t. 12, f. 8, 9.— SOWB., Conch. 111. f. 77.— RKEVE, Conch. Icon. t. 7, f. 33.— Tonicia lineata Wood, H. & A. AD., Genera Rec. Moll, i, p. 474. — Tonicella lineata CPR. MS., p. 38.— DALL, Proc. U. S. Nat. Mus. 1878, p. 326. In many old specimens of this species the teeth are distinctly, though obsoletely crenulated and striated outside, presenting an approach to Tonicia.. The slit in the median valves frequently has its edges thickened, and there is a distinct notch on each side of it. This is one of the handsomest north Pacific Chitons. It is read- ily distinguished from T. marmorea and T. submarmorea by the absence of microscopic granulation of the surface, as well as by the pattern of coloring. Dall writes : The painting of this very characteristic species is very variable, even on different valves of the same individual. Nothing can appear more distinct than the coloration of typical specimens of some varieties, but in a large series the differences do not hold equally good. The number of slits is also somewhat variable, occa- sional abnormal or injured specimens having only six or seven slits in the tail valve. But fine and normal specimens of both varieties show no more than individual variations. Middendorff, while pointing out the distinctions between the fol- lowing species and T. marmorea, appears to have overlooked the connection between the former and T. lineata and his description does not always agree with his figures. From Tonicia lineolata Sowerby, from South America, besides the internal generic characters, the exterior differs by the absence of punctures and raised granules at the sides. 44 TONICELI-A. T. SACCH A i : i N A I )al 1 . Unfigured. Shell small, oblong, the entire surface painted with lustrous red and whitish. Urabo subcentral, inconspicuous. Lateral areas indistinctly raiaed ; dorsal area blood colored, reticulated in quin- cunx. Anterior valve having 10-11, posterior 8-10, median 1 slit. Teeth small, spongy ; sinus small ; eaves spongy, moderate, (•irdle leathery, (iills median. Length 6£, breadth 4 mill. i ami Shumagin Is.; Kyskn, Utialashka, and Koniu*hi, 8 fa&, on stones; St. Paul, Pribiloff Is., 15 fms. i it-ell n miccharina DALL, Proc. U. S. Nat. Mus. 1878, pp. 2, 827. This interesting little species has the luster of rock-candy, through which the microscopic reticulation is barely perceptible. It is marked in all the specimens obtained, by the red wine colored dor- sal areas contrasted with a waxy white color of the lateral areas, rendering its recognition easy. The girdle is dark, leathery, nar- row, slightly pubescent, and furnished at its extreme margin with a fringe of fine spiny hairs or spicules, as in T. marmorea. T. SITKKNSIS Middendorff. PL 11, figs. 29, 30, 31. Shell depressed, smooth, the lateral areas indistinct, under a lens seen to be sparsely granulose ; reddish. Anterior valve having 8, 1". -tenor 10, central 1 slit. Gills posterior. Length 10, width 6 mill. ; divergence 130°. Sitka. C. sitketms MIDD., Bull. Acad. Sci. St. Petersb. vi, p. 121, 1846 ; Mai. Ross, i, p. 112, t. 13, f. 1, 2.— Not C. sitkensis Keeve, 1847. I >• scribed from a single specimen, and not found by later collec- Middendorff 's figures and description do not agree upon sev- t-ral points. The anterior teeth are figured as grooved outside, a character also seen in T. lineata. Subgenus CYANOPLAX Pilsbry, 1892. Valves resembling those of Ischnochiton, but having the teeth MMiit. obtuse, crenulated or hi- or trilobed at their tips; and the • •:!'.• — [">i,j\ -. (iirdle leathery, miniftely papilloBC. (Jills extend- ing to the anterior end of the foot. I)it}!-r> from ( '/mtojtfeura in the spongy eaves and papillose, not Jfiini Lrirt<-l,>j' 1*71, and of DALL, Proc. U. S. Nat. Mus. 1882, p. 286, not Cnllochiton of Carpenter's earlier writings (P. Z. B. 1865, p. 276, etc.), — Callistochitnii. Valves exposed ; insertion plates rising out of porous or spongy — and cut into numerous teeth; sutural plates connected or continuous across the shallow jugal sinus. Two subgenera are recognized by Carpenter: Subgenus CALLOCHITON (restricted). < iirdle covered with a smooth, compact layer of very small dia- mond-shaped scales. • Subgenus STEREOCHITON Cpr. ( iirdle leathery, more or less downy, frequently naked when the delicate scales are rubbed off. Subgenus CALLOCHITON s. sir. The essential characters of the restricted genus Callochiton are correctly stated by Carpenter as follows: (1) The insertion plates are broken up into very numerous teeth rising out of spongy eaves ; (2) that these have a tendency to become propped outside ; (3) that the sinus is a mere wave in the otherwise united branches of the sutural lamina ; (4) that the mantle is reticulated with what look like diamond-shaped scales, which are only the points of long, flat- tened, closely appressed corneous bodies, not found on any other Chiton. For Gray's second group, in which the peculiar covering is not seen, a subgenus should be created, unless indeed the species may rank under Trachyradsia. For two species with a mantle intermediate between ( 1m topleura and Tonicella I have establi.-hed a subgenus Stereochiton. Of the whole series there are very few species known. All of them are rare and display very little sculp- ture on the val\. ~. ( ALL. HIM l<>\. H» C, i BVIS Montagu. I'l. !» figs. !»:>-<)9. Shell oblong, rather elevated and rather acutely earin;i(ed. tin- Bides Straight Or convex. Color very variable, but niainlv vellow- ish-olive, spotted and marbled more or less with dark rod «»r n-ddi.-li, but green often predominating. Girdle olive with creamy spot-, and often red patches. The valves are slightly beaked and apparently smooth, but under a lens a fine but half-effaced granulation is seen. The lateral areai are distinctly raised. The umbo is low and in front of the center. Interior pink-tinted. Anterior insertion plate having 14 to 17 slits, median valves with about 3 slits, posterior valve with 14-K> slits. The teeth rise from very spongy eaves, and are more or less thickened at the sides or "propped." Sutural plates continuous, the jugal sinus indicated by a shallow depression. Girdle firm, smooth and wide, composed of excessively fine dia- mond-shaped scales. Length 21, breadth 11 mill., sometimes larger. British Seas; Mediterranean. Chiton l(cvis MONTAGU, Test. Brit. p. 2. — REEVE, Conch. Icon, f. 125.— FORBES & HANLEY, Hist. Brit. Moll. p. 411, t. 58, f. 3.— JEFFREYS, Brit. Conch, iii, 226, t. 56, f. 6. — Chiton marginatus of some authors. — C. achatinus BROWN, Illustr. Conch. Gt. Brit. p. 65, t. 21, f. 4, 12, 13, 15. — C. septemvalvis MONT., Test. Brit. p. 3 and C. discprs MATON & RACKETT, Trans. Linn. Soc. viii, p. 20. — Chi- on cranchianus LEACH, Moll. G. B. p. 230. — Lepidopleurus punctu- latus LEACH, 1. c. p. 228. — Chiton dorice CAPELLINI, Journ. de Conchyl. (2), iii, p. 325, t. 12, f. 2, a", b", c", 1859. This is a rather high and sharply keeled species although depressed specimens occur. It may be known from other Euro- pean Chitons by the comparative smoothness of both valves and girdle, the latter wide and covered with very fine diamond-shaped scales ; by the propped teeth and spongy eaves, the number of slits in the median valves, etc. The Mediterranean form has been called C. dorice, but I am unable to see that it has distinctive characters. C. PLATESSA Gould. PI. 10, figs. 1-5. Shell smooth, entire surface delicately shagreened, terminal valves and lateral areas only with indistinct concentric lines of growth ; 4 50 CALLOCHITON. lateral areas not prominent, with no radial markings; umbones small, pointed. Girdle. — With delicate flat elongated scales. Gills. — Extend along whole length of foot, about thirty in num- ber on each side. Color. — Central areas yellowish, obscurely mottled with orange ; on some valves there are a central and a lateral pair of pale lines. Lateral areas and terminal valves of a uniform dull orange color, and uniformly spotted with minute black dots, which are absent from the central areas, the posterior border of the valves is orna- nirntrd with alternate lighter and darker spots. Ligament brown- ish, with a few irregular small white flecks and five large white spots, four very large spots extending from the points of junction of the first and second and seventh and eighth valves respectively t<» the edge of the girdle; the fifth spot being in the median line N'riorly. (Haddon.) Interior. Posterior valve with 14, anterior 16 and median valves with :! slits. Teeth solid, separated, propped outside, bifid or aped. Eaves very spongy, simple, short. Sinus small, wide ; sutural plates united; girdle normal. (Qor.) Sydney; Port Jackson; Botany Bay ; Australia; (and New Zea- land?). C.platessa GLD., Proc. Bost. Soc. N. H. ii, 1846, p. 143; U. S. ExpL Kxped. p. :;L>O; atlas, f. 434, 434a, left hand, under Ch. fru- ticosus. — I.rjtiiluji/enru plntessa GLD., Otia Conch, p. 242. — Callo- chiton platessa Old., CPR., tnss. — HADDON, Challenger Rep. p. 1 5.— ' 'It if on i-winns Rve., Conch. Icon. t. 22, f. 14(5, 1*47.— Chiton ver- sicolor A. AD., I'. /. 6, \*~>'2, p. !)2, t. 1(>, f. ~).—Leptochiton versico- lor, ANCIAS, P. Z. S. 1867, p. 223. There is an error in the lettering of Gould's plate, the figures iM-inir niimlx-red 4:54 instead of 431. There is considerable varia- tion in coloring. C. versicolor, which Carpenter considered a syn- onym, is represented in pi. 10, fig. 6. C. crocinus (pi. 10, fig. 7) is a larger form, length .V> mill., said to be from New Zealand. C. PRINCEPS Carpenter, n. sp. Shell large, very flat, oval ; JIILMIIM annulate ; red, streaked with paler and deeper. Posterior valve large, very flat, the median umbo inconspicuous. Lateral areas hardly defined; central valves OALLOCHIT" .'-1 rounded at the mai-iiins, sometime- (abnormally?) p«-«-t mated. Knlhv surface roii-pirimiisly hut minutely 'jTaimlat.'d. Interim-: Posterior valve having 1 7, anterior I *, median va ."> slits. Teeth elegantly radiately propped, curve*! outwunl, tv three lobed, sometimes striated. Kaves short, reddish, sp<.nirv. Inside Iiurht fle.; The complicated external structure of the insertion plates is more beautiful in this than in any other known species, resembling the fret-work of a Gothic pinnacle. It is specially displayed where the eaves have been broken off through accident, and the grooving is displayed under the colored part of the valves, which are there pec- tinated at the edges. It is unfortunate that the locality of this typical species is unknown. (Cpr.) C. ILLUMINATUS Reeve. PI. 9, figs. 92, 93, 94. Shell oval, red, rather elevated, the jugum acute ; umbo a little in front of the middle, slightly elevated. Entire surface very min- utely wrinkle-striate and granulose under a lens, the central areas longitudinally, the rest radially. Central areas with slender ele- vated separated threads, parallel to the jugum, 6 to 14 on each side. Lateral areas rather elevated. Interior roseate. Anterior valve with 15-16, posterior with 11-14 slits, median valves with 1 slit. Teeth acute, quite distant, scarcely propped. Eaves spongy, sinus small, the sutural plates connected across it. Girdle normal, the scales rather large, solid ; sometimes spotted with paler at the sutures. (Q>r.) Length 16, breadth 10 mill. ; divergence 120°. Straits of Magellan* Chiton illuminatus REEVE, Conch. Icon. t. 22, f. 147,1*47.- C. (Callochitoii) illuminatus Rve., SMITH, P. Z. S. 1881, p. 35. — Lepidopleurus illuminatus ROCHEBRUNK, Miss. Cap Horn, p. 141. There are about 16 gill plumes on each side, reaching three-fifths of the distance forward, according to Carpenter. In having but one slit in the median insertion plates and in the want of props on the teeth this species is abnormal ; in other respects it agrees with Callochiton. 52 CALLOCHITON. Subgenus STEREOCHITON Carpenter. Stereochiton CARPENTER MS., 1871.— DALL, Proc. U. S. Nat. Mns. iss-j, ,,. -JM; (type C. castaneus Wood). Valve- like Callochiton, but the girdle leathery and downy, the scales very delicate and deciduous. In this group the teeth are numerous, the median valves having 5 or more; but on account of tlu-ir narrowness they do not always, have the lateral buttresses or props outside, so characteristic of the teeth of the true Callochi- ton <. The eaves are very narrow, but distinctly porous or spongy, as in Callochiton, and the bottoms of the slits are also coarsely spongy'. The sutural plates are continuous from side to side, the nir.liaii sinus being a mere wave, also a characteristic of Callochiton.. It is therefore obvious that the characters of the girdle alone sepa- rate Stereochiton from Callochiton. In C. castaneus the girdle of moderate sized specimens is always, so far as I know, denuded of most of the covering of downy scales, but under a strong lens the close, fine markings where they were inserted in the girdle may be seen, as well as occasional scattered scales. Stereochiton externally resembles Tonicella, but it may be at once distinguished from that group by its numerous side slits. C. CASTANEUS Wood. PI. 9, figs. 86-91. Shell oval, depressed, dark chestnut brown or variegated with lighter brown. Jugum obtusely keeled ; lateral areas rather distinctly defined, slightly raised. Entire surface very minutely, densely granulated, when seen under a lens ; the granules low, not arranged in distinct lines, but an obscure oblique radiation is more or less visible. Growth striae light. Umbo of the posterior valve some- what in front of the middle, somewhat elevated. Interior rose colored; Anterior valve with 20, posterior with 18, median valves with 5 deep slits. Teeth rather high and narrow, blunt, not propped, those of the terminal valves frequently bilobed or Lrilobed inside, and obtusely crenulated at their apices. Inter- stices spongy. Eaves very narrow, short, spongy. Sutural plates connected, the jugal sinus shallow. Girdle leathery, bearing (when 'not rubbed off) delicate elongated scales. Length 42, breadth 28 mill. Cape of Good Hope. Chiton castaneus WOOD, General Conchology, p. 13, t. 2, f. 2, 3 ; t. 3, f. L>, :j, 1815.— SowERBY,Couchol.Illustr.f. 114, 115.— REEVE, BOHNOOHTTON, Conch. loon., t. f>, f. '.>."». --Nor <\ ;//X (J.uoy nor ('. Conth. — C.certitiim* '*//, •/////., RI:I:YI:, Com-h. Icon. f. i;;j. This Bpeciee IB Variable in colorinir, IteinireitlnT uniform brown or having spots and patches of l)ro\vn on a lighter Around. The interior is always roseate. The numerous narrow teeth, short spongy eaves, spongy slits, etc., readily separate it from other forms. C. LOBATUS Carpenter, n. sp. PI. 8, figs. 83--S-"). Shell large, flattened, with acute jugum; intense olive colored; iimbo median, the posterior slope concave. Valves scarcely beaked, rounded at the margins. Lateral areas not well defined. Entire surface minutely granulated in quincunx. Interior : Posterior valve with 20, median valves 5 to 7 (usually 6, the posterior minute), anterior valve 24 slits. Teeth small, deeply separated, and outside very strongly propped, as if bilobed ; interstices deeply spongy. Eaves small, spongy, grooved inside ; sinus subobsolete ; sutural plates connected. Girdle leathery, smooth, under a lens seen to bear short, minute, sparsely placed hairlets. Length 41, breadth 27£ mill.; divergence 130°. Tasmania. (Mus. Cum. No 19.) This fine and curious species has the general aspect of Mopalia vespertina (from which it is known at once by the lophyroid mucro) ; the insertion plates, props, spongy eaves and minute sinus of Callochiton ; and a mantle resembling an aberrant Tonicia. Genus XI. ISCHNOCHITON Gray, 1847. =Ischnochiton + Tracliydermon -f- Maugerella Cpr. Valves external, having sharp, slit, insertion plates, the teeth not buttressed. Eaves solid (rarely somewhat porous in s. g. Trachy- dermoii) ; girdle covered with imbricating scales, either flat or con- vex, smooth or striated. Gills typically extending the entire length of the foot, but in some species they are short in front or at both ends. Ischnochiton is the typical or central point in development of the sharp-toothed division of Chitons, around which the other genera naturally group themselves. The great diversity in the girdle covering permits us to use that character for the foundation of a number of subgeneric and sec- tional divisions, as follows : 54 ISCHNOCHITON. Synopsis of Subgenera and Sections. Subgenus I. STENOCHITON Ad. and Ang. Very much elongated, valves longer than wide, roundly arched, the median valves having several slits; unibo subcentral ; girdle covered with minute, smooth imbricating scales. Subgenus II. STENOPLAX Cpr. Elongated, narrow, the posterior valve large, depressed, with sub- central or posterior umbo. Girdle covered with small crowded striated scales. * Section Stenoplax s. s. Median valves 1 slit. Section Stenoradsia Cpr. Median valves with several slits. Subgenus III. ISCHNOPLAX Cpr. Elongated, narrow ; posterior valve elevated, the umbo posterior; girdle covered with very minute scales, having conspicuously larger, striated scales mingled among them. Subgenus IV. HETEROZONA Cpr. Shell like normal Ischnochiton. Girdle bearing small scales with large striated scales intermingled. Subgenus V. TRACHYDERMON Cpr. Oval ; valves having the sharp teeth of normal Ischnochiton ; eaves narrow, rarely spongy. Girdle having very small smooth scales. tion Trachydermon s. s. Median valves having one side slit. Section Trachyradsia Cpr. Median valves having more than one side slit. Subgenus VI. ISCHNOCHITON (Gray) Cpr. Oval or oblong; valves having sharp smooth teeth and solid eaves. Girdle covered with short flat, generally striated imbricating scales of moderate size. Section Ischnochiton s. s. Central valves having one slit. Section Radsiella Pils. Central valves having two or several slits. I8CII\«.« mi 55 \'||. [00H2TORAIMSU Shuttles. Shell oval, as in Isehnoehiton ; irinlle covered with .-olid, n.rivex, smooth scales, like those of Chiton 8. 8. (ion lacJiiiui'ttdfiift s. s. Median valves having several side slits. Type £ atotro/w Sowb, Sretioii LepidozoiKi I'ils. Median valve- having one side; .-lit. Type /. inertensii Midd. Subgenus I. STENOCHITON Adain.s and Angas, 18f>4. Stenochiton AD. AND ANG., P. Z. S. 1864, p. 193. Shell very much elongated, roundly arched ; valves Ischnoid, the central valves havi ng several slits ; girdle having minute smooth imbricating scales. This section was discarded by Carpenter, who referred its only species to his own later group Stenoradsia with doubt ; Stenochiton, however, seems to have as much individuality as most of the divis- ions of Ischnochiton, and may be allowed to stand as a subgenus. I. JULOIDES Adams and Angas. PI. 16, figs. 6, 7, 8. Shell much elongated, narrow, narrower in front; rufous brown, minutely spotted with white. Valves narrow, longer than wide, very convex, not carinated ; lateral margins scarcely rounded, pol- ished. Lateral areas elevated and at the margins concentrically sulcate. Girdle narrow, pale-brown, spotted with black-brown, covered with very minute, polished, imbricating scales. (Ad. and Ang.) Length 25, breadth 6 mill. Holdfast Bay, South Australia. Stenochiton juloides AD. AND ANG., P. Z. S. 1864, p. ?93 ; I. c. 1865, p. 58, t. 11, f. 15.— ANGAS, P. Z. S. 1865, p. 188.— " f St* adsia " juloides Ad. and Ang., CPU. MS. This species, from its narrow, convex form and polished surface has much the general appearance of a Myriapod. (Ad. and Ang.) This species is the type of the genus Stenochiton Adams and Angas, which is thus characterized by them: "Shell elongated, narrow, convex ; valves longer than wide, not carinated; apex of the posterior valve subcentral ; plates of insertion small, multi- fissate in the end valves, the intermediate valves having T> li- on each side; girdle covered with very minute, polished, imbrica- ting scales." 56 ISCHNOCHITON. Carpenter gives the following notes on the type specimen : Length 22*, breadth 4 ' mill. ; shell very narrow, elongate, elevated, cylin- drical, the juguni rounded ; red-brown, narrowly streaked with paler. Posterior valve elongated, mucro median, scarcely conspic- uous, the slope behind it straight. Anterior valve forming more than a semicircle, its posterior margin (suture) emarginate. Entire surface delicately granulated in quincunx; jugal area scarcely defined ; lateral areas conspicuously elevated. Girdle inconspic- uous, covered with minute imbricating scales. Scales almost all destroyed, but looking like those of /. sanguineus, etc. Sinus large, very deep, flat, wide; sutural plates much elongated, narrow. Central valves regularly 3-slit; posterior valves about 16, anterior valves about 13 slits. The slits are irregular, sometimes bifurcating but typically rather distant. Teeth very acute, moderately long. Eaves moderate. Subgenus II. STENOPLAX Carpenter, 1878. = Stenoplax Cpr. -f Stenoradsia Cpr. -f- Maugerella Cpr. Elongated, narrow Ischnoids, having the girdle covered with minute, crowded, imbricating striated scales. Median valves having the lateral areas much raised ; posterior valve large, depressed, the mucro subcentral or slightly posterior. The subgenus Stenoplax (-f- Stenoradsia and Maugerella) has a very characteristic peculiarity. The sides and front end of the foot are so much dilated that the head of the animal is nearly or entirely concealed from below, the thin, produced, anterior end of the foot extending quite over it The gill row is shortened at both ends, reaching nearly to the head, but shortened at the tail about one- fourth the entire length of the foot. .The branchiae are largest at the middle. STI:N< 'iM. \x divides naturally into two sections: (1) Section >plax (restricted), in which the median valves have a single >lit on each side, and (2) Section Stenoradsia, the species of which have two or several side slits in the median valves. Section Stenoplax Cpr. (restricted). - noplax CPU., MS. and table of Regular Chitons, 1873. — DA LI., ,U.S Nat. Mns. 1878, p. 330, type /. limaciformis Sby. This section is closely allied to Stenoradsia, the latter differing only in having several slits in the plates of the intermediate valves. ISCHHOCHITOH. I. I.IMA< ll'oKMI- Si.wrrhy. PI. Hi, fi.LTS. •' I'J. Shell rl.m'jaled and narrow, elevated, well areh. d : bull irreriiish, indistinctly marldrd with darker, and occasionally blotehed with red; longitudinally costulate, not graiiosc ; <_rirdl< minute. The sculpture upon the central areas con>ists of line, close, smooth lon-itudinal rildets; these continue upon the lateral areas, becom- ing broader and Hat there, and being decidedly waved or irregular on the slope between central and lateral areas. The end valves are sculptured with close, flattened concentric ridges, which are more or less wavy or irregular. The lateral areas are well raised, and are separated by a considerable space at the jugum. The mucro is subcentral and low. Interior stained with bright pink and blue-green ; sutural plates well developed ; sinus flat, angular, wide; anterior valves with 11, central valves 1, posterior valves 9 slits. Teeth sharp, smooth ; eaves grayish, solid. Girdle covered with extremely minute subequal scales. Length 35, breadth 12 mill. Length 25, breadth 10 mill. Florida Keys ; St. Thomas, St. Vincent and West Indies gener- ally; Central America and Peru; under stones at low water. Chiton, limaciformis SOWERBY, P. Z. S. 1832, p. 26; Conchol. Illustr. f. 38. — KEEVE, Conch. Icon. t. 8, f. 42. — Ischnochiton ciformis SHUTTLEW, Bern. Mittheil. 1853, p. 190. — (Stenoplax) limaciformis Sowb., CPR. MS., and DALL, Blake Gas- trop. p. 415. — Ischnochiton multico status Ad., DALL, Proc. U. S. Xat. Mus. vi, p. 337, 1883, not of C. B. Adams. — Chiton prodwhi* Ilr.KVE, Conch. Icon. t. 17, f. 97, 1847. — Chiton sanguineus Ki i:\ i:, /. c. f. 98. — f Lepidopleurus sanguineus CPR., Ma/. ( 'atal. p. 1(.>4. The West Indian specimens collected by Robert Swift at St. Thomas, and the Peruvian specimens which I have examined are absolutely identical in character except that the former are finely mottled with pink, and one specimen is heavily blotched with crim- son on the second and tail valves (fig. 9). Another tray from the Swift collection contains pale but!' examples with faint darker markings. Carpenter has reported the same species, or one very closely allied, from Ma/at Ian and from Japan. The last certainly requires confirmation. 58 ISCHNOCHITON. The characteristic mark of this species is the sculpture of the lateral areas and end valves, which are non-granulated but have slightly serrated concentric flat riblets. The girdle scales are flat, solid, not striated or very obsoletely so, and far more minute than in /. n /ut n.-: I. FLORIDANUS Pilsbry, n. sp. PI. 17, figs. 19-22. Shell elongated, narrow, elevated, the valves roundly arched, not carinated. Color whitish or delicate green, variously marked and mottled with olive, blackish-olive or gray. The lateral areas are raised, longitudinally costulate, the riblets cut into granules by radiating impressed or incised lines devel- oped over the whole area or over the forward half of it. End valves similarly cut into granules by radiating and concentric lines. Cen- tral areas covered with longitudinal riblets which are finer and closer upon the jugum, usually showing a tendency to be a little irregular on either side of it, and are granulous toward the outer angles of the areas. Posterior valve large, rather depressed, the mucro slightly posterior. Interior pink, blue and white, in various proportions, rarely all roseate or all white. Sutural plates strongly developed, rounded ; sinus wide, deep, square. Anterior valve having 9, central valves 1, posterior 9 slits; teeth sharp, smooth or very obsoletely lobed. Eaves narrow, solid. Girdle delicately marbled with bluish and gray, densely clothed with rounded, solid, delicately striated scales. Length 41, breadth 15 mill. Length 35, breadth 1U mill. Key West, Florida. (Hemphill.) This species is allied to J. limaciformis, differing in the differently sculptured lateral areas. It is also related to C. purpurascens C. B. Ad., but differs in several respects, notably in the flatter poste- rior valve and longer central valves. I. i-L'RPURASCENS C. B. Adams. PI. 17, figs. 23, 24. Shell <-l<>iiLrat< mi 59 and (M.ncciitfic lines. Central areas having tin- dorsal ridi" or only minutely punehired ; the longitudinal riUets of the lateral area- extend forward Upon the "pleura" or lidet "| tbc e.-ntral areas. Posterior valve elevated, the IMIICTO .slightly posterior, elevated. Interior white or stained ; sutural plates short; sinus wide, tlat. Anterior valve having 10, central valves 1, posterior valve ID -lii~. Teeth sharp, smooth. Eaves narrow. Girdle rather wide, alternately bluish and buff, densely clothed with minute, solid, striated scales. Length 16, breadth 7 mill. Jamaica (Adams) ; Key West, Florida (Hernphill ; Rush.) Chiton ]>iii-]>iirhy : veil copious, neck lappets long. Gills about one valve's luvadth removed from neck and the same at tail. Vent inconspicuous. Foot fleshy, projecting. [01 ll\... ill i , 1 ferpeoter, 1*7*. , i/\. mid tahl.- of i;«- ci.it : Proc. r. s. N:,t. M.IS. I.STS, P. 830, type G maj B —M times light flesh-colored, with the jugum or central areas often green. Girdle dark ashen or olive. The anterior valve is notably concave, as in /. conspicuus. Tin- lateral areas are much raised, and sculptured with acute radiating riblets, sometimes splitting; central areas having acute longitudinal riblets. Interior pink, with a blue spot at the jugal sinus. Sutural p! wide, pink; sinus broad, deep, angular. Anterior valves having 13-15, central valves 2-4, posterior valves 10-13 slits. Teeth long, sharp, smooth. Eaves wide, dark-blue. Girdle wide, tough, covered with very small, solid, shot Length 110, breadth 55 mill. Length 75, breadth 40 mill. Cerros (Cedros) Island to Cape St. Limn.*, Lower California, StenoradsiaacriorCpR.MS. — Chiton iintfjd'i/eneimiin part Ki i Conch. Icon. t. 4, f. 20a, not of Hinds. This species represents one extreme of variation of the / magdalenensis type, the other extreme being 7. con^»icun.<. 1 i 62 ISCIINOCHITON. still to see specimens truly ronnoctinir the three forms, although they arc doubtless closely allied. The present form differs from }n>igd'ilenen*is in having a concave head valve, strong, distinct, acute riblets upon the central areas, and a generally more robust A th. /. t '•« also has a concave head valve, but the sides of tin- central areas show no sculpture except microscopic granulation, and the scales of the girdle are pulled out into true spines or bris- tles. There is a light form of acrior which is fleshy-white, the girdle gray-white or dark ; and some of these have the jugum or the cen- tral areas of the normal green-olive color (fig. 89.) 1. M A.-I.AI KNKNSIS Hinds. PI. 15, figs. 98, 99, 100. Shell elongated, rather narrow, generally faintly mottled with delicate olive on a light greenish, blue or pinkish ground. Interior bluish, white or pink. Lateral areas and end valves having radia- ting riblets, central areas finely pitted. The lateral areas are distinctly raised, radiately delicately ribbed. Front slope of the anterior valve straight. Central areas having a more or less developed system of branching reticulating wrinkles pro- ilncnig oblong or diamond- shaped pits. Umbo of posterior valve central, but little projecting. Interior : Sutural plates well developed, the sinus deep, angular. Anterior valve having 10-13, central valve 2-4, posterior valve 10-12 slits. Girdle having fine, close, solid imbricating scales. Length 75, breadth 30 mill. ; divergence about 130°. Length 55, breadth 27 mill. Monterey, California, south to Magdalena Bay; Catalina and Sta. Barbara Is. Chiton magdalenensis HINDS, Zool. Voy. 'Sulphur' ii, p. 54, t. 1 :». t. 1 . REEVE, Conch. Icon. t. 5, f. 20b. — Stenoradsia magdalen- ensis CPR. — S. "magdalensis" Ki;i:r, West Coast Shells, p. 107, f. 94, and of collectors generally. This species differs from /. conspicuus in its pitted instead of finely granulose central areas and in the mantle-covering of minute, solid scales, unlike the short spines of the other form. It differs from 7. • /• in the much finer sculpture and more delicate coloring. rSOHNOCHT] »'».'! Tin- loot projects foruard, conceal! MI: tin- lim.j tV-.m bttN :itli. I. . 02XBPX4 GUfl Carpenter, n. ip, I'i Shell lar^e, elongated. moderately elevated; greei earthy-brown ), luit \\ lien- eroded at tin- heaks it i^ pink. In! pink, witli a blue spot at tin- juiral -inn-. Lateral an-as much raised, having acute radiating rilil. : enlly *mnnih, but microscopically -rauulated, BOtQetitiK faint longitudinal strice at the jogum, Front */ope of th< i' vet- 1'i'tll nfJiCrt. The entire surface is very densely miero-eopieally granulated, where not eroded. The lateral areas have fine aeute radii and often the back edge of each valve is crenulated by oblique, sharp, little folds. The color is often varied by darker little flame- on tin- central areas. The posterior valve is large and depressed. The sutural plates are large, the sinus deep and angular. Inser- tion plates having in anterior valve 9, central valves 2 or 3, j> rior valve 10 slits. Teeth sharp and thin in posterior and central valves, but blunt and bi- or trilobed in anterior valve. Eaves wide. solid, light blue-green colored. Length 82, breadth 36 mill. Length 89, breadth 41 mill. Santa Barbara, California, t<> Magdalena Bay. Maugerella conspicua CPR. MS. — OROUTT, Proc. U. S. Nat. Mu>. 1885, p. 544. This species may be separated from /. amor by its unsculptund central areas and velvety rather than scaly girdle. It is more closely allied to I. magdalenensis and may, indeed, prove tointergrade with that species; but in magdalenensis the front valve is scar concave in front, the sides of the central areas have a honeycomb sculpture, and the girdle is very finely sc<><•( in, it //.< S«,\\ I ;.. M a-. , ,f N ill . I I i~f ., .lime. |S-lU. p. : ' t. 1C., t'. :i ; Conch. Illustr. ('. 1 1C,. |;, ., \ , . ( ',,, ,,.),. I 1 83, ' '• /-•'•hnn.'hitiiii i pectinatu* SIM n u.\\ ., Hem. Mitthdl. I |t. 77. — •I.tf'hnniilii.r }irrtiu'lfu.i CPB., M>. — Chiton ncnti/i, KI:I;\I:, Condi. Icon. t. *, f. Mt.--Chitnn miill'u-n*tuhi# ('. \\. Ah., Proo, r.«.st. Boo, N. II. ii, |». 8, ! LVadily known from other \Ve>l India ( 'hitons liv its dong r.inn, speckled and mottled coloring, SUM! especially \>\- the peculiar ^irdlo. The larirf scales are distinctly but finely Mriated. The grOUnd-Oolor of the girdle is pale bufl', with patches of olive- ii'reen. The larLie scales are mingled white and buff on the liirlit tracts, and are a dark blue-green on the dark patches. Reeve's C. acutiliratm (fig. 30) is a typical pcH'n, : posterior valve having the macro central. Interior white, the end valves usually marked with a brown crescent; sutural lobes rounded ; sinus wide and flat. Anterior valve having 12, median valves 1, posterior valve 12 slits; teeth smooth, rather .-harp. Kaves solid. (iirdle covered with flattened striated scales, which are verv unequal in si/.c, but become larger toward the valves (fig. 21). Length 32, breadth HI mill. Australia, The texture of the shell is peculiar, the outer layer being thin and easily broken through, exposing an extremely spongy layer. ( arpenter's specimens seem to have been worn so as to expose this layer in places, hence the name cariosus. In the normal and un- worn specimens before me the outer surfare is scarcely carious though dull and uneven, nor are the eaves spongy. Carpenter's original description is as follows: Heterozona cariosa (pi. 24, fig. 23). Shell subelongate, rather elevated, the jugum rounded. Mucro median, moderately elevated ; whitish-ashen, slightly variegated at the sutures occasionally. Central areas very granose in a young specimen, the granules minute and close toward the jugum, then becoming rugose lines, undulating anteriorly, and widely separated on thesides; the adult shell is carious. Lateral areas having 3-8 deeply but irregularly granose radii, the grains at the sutures large; end valves having 30-40 graniferous radii. Interior: posterior valve with 11, central 1, anterior valve 11 slits. Teeth acute; eaves wide, spongy; sinus large, flat, smooth. Girdle (pi. 24, fig. 23), clothed with nornal striated imbricating scales and having long, large striated solid scales scattered here and there. (Qt?r.) Length 30, breadth 161 mill., divergence 100°. Australia (Mus. Cuming No. 46). This shell forms an exact transition between Ischnoplax and the true Ischnoehiton. The mantle resembles Ischnoplax in its double series of scales ; although if the large ones were plucked out, the latter would be nearly of a normal arrangement, except that they aiv rather nariow a- in /. castns. It differs from 7>r///>oy,A/.r, not only in not lu-in^ narrow and elongated, but in having a normal IIMKTO. The species is curiously like Stciiormltn'n magdalenentis, HNO in i' younir, ill .-hape :in -eripljnii anI:I:M<>\ ( 'arpenter, 1863. ., Kep. l',rit. &MO. Adv. Sri. L863, p, G. O. SABS, Moll. lie-. A ret. Norv. p. 1 i IVmi. - - cinereus L.). — Boreochiton S\i;- in ; p. lit! (proposed for C. ruber Lowe and C. marmoreiu Fahr.;. — (liitoii, Lepidoplewrus, Leptochiton, Ischnochitnn and /,'>/>//>//•" • •!' various authors. Valves exactly like those of Ischnochifou, hoth diitside and within: girdle having the scales very small, close and sim...tli. (Jills from one-half to over three-fourths the length of the ; This irroup was originally proposed as a suhgenusof I.«r]nnn-1, and the following species referred to it: refij><>r<>. (1pi-., unltxUii Cpr., flectens Cpr. Carpenter subsequently stated that Trac.hydermon was equivalent to Gray's second section of Ischnoehiton, " ** scales of mantle minute, granule-like." (1*. /. S. 1847, p. 127), this section containing only the species P. >//'//•'/'/'- »////x C. cinereus L. and Lowe. Still later, Carpenter raised the group to the rank of a genus, adding to his diagnosis the words "gill- short." It is evident that a type species for the group should be selected from Carpenter's original list; not from among the species si; quently referred to the group by him. The shortness of the Drills influenced Carpenter and Dall to place this group next t«> the Leptochitons, but there is probably no affinity indicated l>y this character, Trachydermon being phy to genetically as far from 7. ffi iton as Ischnoehiton is. The length of the gill-row is so variable that genera cann« founded upon that character in the present family. In the species itllms and ruber I have ascertained the gills to l>e median, as they are said to be also in the tcrobieukUvs and //» of Midd. In the other species which I have examined, or upon which data are available, interstinrtii.-*. 0 the irills extend from two-thirds to over three-fourths the length <»t' th. 68 IM IIN<»< IIIToN. It is therefore obvious that n<> separation can he made from other suhueiiera of hchnochiton on this character. Several species of Trachydermon liave distinctly spon_ like tlinse of T"/tir>//*i. This structure is exceptional in 7.W/M*- chiton where the eavee a- a rule, aie solid, as in the genus Cluito- i. The fact i>e that certain forms of Trachyderinon, such a< T. ruber, form a partial transition from hchnochiton to • /A/. From ZVoMyrfermon, Carpenter has sundered a few species hav- ing Kadsioiil central valves, to which he has given the sectional name Ti: \< H \n\ i»i \. Section Trachydermon, s. sir. I. CINEREU8 Linn.'. PI. i«le. Number of slits in the anterior valve 9 or 10; in the posterior valve 10 or 14J. The teeth of the posterior valve are rugose. The intermediate valves have a single slit on each side. lor varying greatly, the most common pattern being a.-hcn thickly mottled and blotched with olive ; others are a li.irht fleshy- oranire. and frequently the light and dark patterns are combined on ;irioiis valve- of one individual. The girdle has usually alternating light and dark bars. It 1 with minute >e;il.-s th«- edge having a fringe of delicate v .-pines. II No. I II TON. r_' ', l.ivadtli 74 mill. Leii-th IS. luvadih ID' mill. liritlnh mid Scandinavian iSV./x. m//-//» /" /,».//•/, •//. XO///A /o /; /\ • / Chiton etfMTtffll LlN* N'at. xii, /rx/r Hanky. Conch. ]>. 17.- -Low i-:, /«>nl. .Joimi. ii, p. 9 II \NI.KY, Hist. r.i'il. Moll, ii, |>. -ID'J, (. .V\ f. 1, (T. ni'iryiifif' plate*.— r. Hinryhntln* IV.N \.\ M, P.rit. /ool. iv, p. 71. t. ::•;, f. 2, and of MONT., Sown., IJ\ i:. and .1 1:1 i 1:1 IB, Brft ( kmch, iii, p. 2'Jl , t. 56, i'. 5j P. /. S. ISS'J, p. 669.— C. marginatus M; Moiuis, Knuna der Kieler Bucht, ii, t. 1, f. 1-5. — Craspedoch'ln* ma ryln.it u« SARS, Moll. Arct. Norv. ]>. 11"), t. 20, f. 16 ; t. 2, f. L'.— Trachydermon mt try hiatus CPR., New Eng. Chitons, p. 1 Trachijdermon. cinereus CPR. MS. p. 15. — DAM., Proc. I Mus. 1878, p. 323. — NOT Lepidopleurus cinereus SARS, /. r., t. 7. t'. 8. — Chiton, circmnrulliitit.* Hi;i:vi:, Conch. Icon. t. 27, f. K This species may be known by the evenly shairreened surtin-r. which is quite different from other North Atlantic Trachydermons. Tr. dentiens Gld., which Jeffreys considers the same as Hnereiift, differs in sculpture, color, and the shorter form. There are a num- ber of old and more or less doubtful synonyms, such as Ch. fiiscatus Brown, 111. Conch. G. B. p. 66, t. 21, f. 17 ; and Jeffreys quotes also cimex Chemn. and cimicinus Landt. Carpenter seems to have supposed that the gills of this species did not extend forward beyond the middle of the foot, but I have determined by the examination of alcoholic specimens, one of which is drawn on pi. 7, fig. 57, that they extend nearly to the head, being composed of 16 or 17 plumes on each side. They are also so figured by Meyer & Mobius. In this character, cinereiu di from albus and ruber, in which species the gills are median. Carpenter, having examined the type of C. circumra/lnf writes that he is satisfied that it is merely a cinereus. The locality given by Reeve is no doubt wrong. Yar. variegatus Phil. PI. 7, figs. 58, 59, 60. Smaller, with triangular sutural laniinir. Anterior valve having 8 or 9, posterior valve having 7 or 8 slits in the insertion plates. Length 8, breadth 5, alt. 3 mill. Mediterraii( ^ 70 I-< IINnrnITOX. variegaku run.., Knum. Moll. Sicil. i, p. 107, 1836; ii, p. 83, t. 19, f. l:>.— WKINKAUFF, Conchyl. des Mittelm. ii, p. 4lL>.— I — i i., Chit. del mare di Geneva, Bull. Mai. Ital. iii, p. 7, t. 1, f. 1, 1870. — Chiton mnrginatus Penn., TIBERI, Bull. Soc. Mai. Ital. iii, p. 139, 154. — MONTEROSATO, Enum. e Synon. p. 16, 1878. — Brn., DAI i/ iV DOLLF., .M..11. Mar. Rouss. i, p. 497, t. 61, f. 13-Ki; t. 62, : I have preferred to retain the Mediterranean form distinct, at least as a geographic variety, for it differs from Tr. cinereus of the north in being constantly smaller, having fewer slits in the end valves, and having the sutural plates of a decidedly different shape. I. Ai.r.rs Limn'. PI. 7, figs. 35-38. Shell oblong, elevated, the back keeled, lateral slopes nearly straight. Anterior valve half-circular, its posterior margin slightly concave ; sculpture consisting of some scarcely perceptible, low radiating ridges, often wholly obsolete, and an excessively minute shagreening or granulation of the whole surface, the granules showing a disposition to be arranged in oblique curved lines. Intermediate valves slightly beaked, produced forward in the mid- dle, having the same sculpture, and showing low, irregular growth wrinkles. Lateral areas scarcely raised, sculptured like the front valve. Posterior valve having the umbo slightly elevated, central, inclined backward. Interior white. Sutural plates large and wide, extending from the insertion plates nearly to the jugum. Sinus rounded. The anterior valve has 13 slits in the smooth and rather sharp insertion plate; the intermediate valves have one slit; the posterior valve has 10 slits, and the edge of the plate is decidedly roughened and irregular. Another specimen has 14 slits in the anterior valve, }'2 in posterior valve; and in still another individual, some of the intermediate valves have two slits on one side. The girdle is covered with small gravelly scales, and has no marginal fringe of long scales or spines. The gills consist of thirteen leaflets on each side, extending for- ward two- thirds the entire length of the foot. The color is a very delicate buff tint, sometimes almost white, often shading into a light orange on the posterior part and lateral areas of each valve. Most specimens have more or less of a blark deposit on the back part of the valves. Length 1."), breadth 7 mill. Length 10, breadth 5-6 mill. »CHNOCHIT< A relic '/•// /W/ n{ .}/,,,, S/. Lawrence, Maine, and south to Mauaehutettt \ In tlir r,icifii- from Arctic Ocean, xo /f///. In tin- .S'/M/w////// /..-., n'ent to h'l/xkn. Low water to :!:;7 f'ms. Chiton ulbii* LINM:, Syst. Nat. xii, p. 1 107.- Lowi:, /•>«.]. .I.-urn. iii. p. SO.— Sown., Conch. III. f. !>'.), UK).- GOULD, Inv. Rfa loi). f. 21.— MlDD., Mai. Ross, i, p. 120.— I-'OKI:I.< A- HANI i;v, I'.rit. Moll, ii, p. 405, t. 62, f. 2.— STIMPSON, Sh. of N. En#l. p, inv. of (Jrand Manan p. 2'J. — .Ji:i'F., Brit. Conch, iii, p. L'-jn ; v. p. 199, t. 56, f. 3.— BINNEY, in Gould's Invert. Mass. p. 265, i. 51 ? Chiton onjzn S]-I:N,;IJ:K, Skrift. Nat. Selsk. iv, hft. 1, 17'.»7, teste JiflV. — Ch. «selloides LOWE, Zool. Journ. ii, p. !().'», t. ">, f. 3. — WOOD, Inv a broad, rounded median sinus ; posteriorly the inner surface is marked by about sixteen radiating lines, terminating in thin notches of the inserted edge, which is very narrow and simple. The marginal membrane is rather narrow and covered with rather stout, prominent, oblong and obtuse spinules, regularly arranged in quincunx, their ends looking like granules, at the edge and on the lower side these are replaced by small slender spinules. Head rounded ; hood large, the sides produced backward into rounded lobes. Foot long and rather narrow. Gills about twenty- four on each side, extending from the posterior end of the foot to about its anterior third. Length, 17 mm.; breadth, 8 mm.; height, 5.5 mm.; length of shell, 1 .")..", nun.; breadth, 7 mm.; length 1st valve, 3 mm.; breadth. (5 mm.: ]"ii_rth .'Ird valve, exposed part, 2 mm.; breadth, 7 mm., length of p -terior valve, 3.5 mm.; breadth, , 1882; Trans. Conn. Aead. S-i. vi, p. 208, UN.., Bin t. :',(>, f.2, 2a,2&.- DM. i, Hull. [ . B, Nai. f. 1'. This species is readily di>t inurnMied from I \ the very di-tinct differentiation of the valves into median and in areas, having lines of sculpture rniiiiin.Lr in diH'en-nt direction-, and by (lie much coarser granulation of their Bdlfaoet, In I. there are no distinct lateral area-; the radiatiirj grooves JIIM| ridge* arc absent ; and the granulation is >o line and ub-mn- a.- ; scarcely visible without a lens. Tlie spinulation of the mar: membrane is similar in the two species. ( Verrill.) I. DENTIKNS (Jould. PI. 8, figS. 61-()~>. Shell oval, rather elevated, dorsally angled, ash colored, clon -ly and finely mottled with olive, and having a series of alternat in ir olive and light spots upon the back edges of the valves ah.ni: the sutures. These spots are often obscure or wanting, and in some specimens the ground color is a pale orange-flesh tint. The valves are covered with a very minute sharp granulation. the granules small but well raised, and on the central areas of some specimens they are somewhat disposed to be arranged in longitud- inal lines converging toward the dorsal ridge, this disposition n-u- ally stronger toward the lateral extremities of the valves. Tin- lateral areas are a little raised, the diagonal lines separating them from the central areas rather distinct. The urn bo of the posterior valve is median, somewhat raised, the slope behind it being depressed and concave. The interior is either whitish stained with gray-green, or quite green. The sutural plates do not project as far as usual, and on some valves they are emarginate in front. The ju.iral sinus is wide. angular, flat or encroached upon by the jugum. The anterior valve has 11 slits in the insertion plate, the intermediate valves 1, the posterior valve has 10 or 12, and some of the median teeth are bifid at the tip. The girdle is narrow, gravelly, covered with minute scales. The gills extend to the front end of the foot. Length 15, breadth 10 mill. Puget Sound (Old.) ; San Diego, California (Hemphill, in A. N. S. P. coll.). Chiton dentiens GOULD, Proc. Bost. Soc. N. H. ii. p. 14">: <>tiu p. 0. — eft. (Onithochitoii) dent ten* ., /. <•., LM'J : 1". S. Kxpl. /4 WCHNOCHH Kxped. p. :i-_M. t. -I:::1. had .— Trnchnd-r, DAM.. Proc. U. S. Nat. Mus. 1ST*, j». :\'i:\. — '!',•< n-hydermon pseudodentiens CAR- RENTER, r.rii. &J8O. Adv. Sci. Rep. 1863, p. (J4!» : Pn.c. Acad. 8cL Phila. !*»;:>, p. 60. This sj>ecies is closely allied to chierens L., luit dillers in the sharper granulation, tlie granules being less regularly arranged, in the tbrm <>f the- sutural plates and the color both externally and within. The girdle of dentiens differs from that of cineren* in lacking the marginal spicules characteristic of that species. The gills are long, as in rhirreus. Gould's diagnosis and figures are extremely incorrect, the liiiht spots alonir the sutures having been mistaken by him f«>r projections. • »r "teeth," whence the name (lcntirn*. ( 'arj)enter ascertained tin- identity of dentiens with the present form by an examination of Gould's type specimen. A series from San Ignacio Lagoon, Lower California, differs from the San Diego shells in being narrower, chiefly dark green (occa- sionally with some lighter valves), and in being more subtly granu- lated. The interior is vivid dark green. One of these is shown in fig. 65. These specimens show a short, slightly acute and beaked umbo on the central valves. In the larger northern specimens this is lost by erosion. nil < :irs Carpenter. Unfigured. Shell small, much elevated, green, elegantly tinted with rose and olive; valves gothic-arched, the dorsal ridge acute; lateral areas small, arcuately distinctly defined, granulose; umbones prominent; umbonal margin having a tessellated color pattern and incurved. Central areas longitudinally ribbed, ribs rounded, close, not much elevated, the interstices small, sometimes slightly decussated. End valves sculptured like the lateral areas, the tail valve having the umbo median and somewhat elevated. Interior having the sutural plates scarcely separated, the jugal sinus very broad and shallow; insertion plates of median valvts having a single slit, terminal plates with -s-10 slits; the plates are obtuse; eaves hardly elevated. (Jirdlemost minutely scaly, the granules very close, rounded smooth; edge with .-mail suberect hairs. ((.'/ Length 5, breadth 2A mill. ; div. 80°. CataliiKi i-< HNO in i (/nth!,-n.< ( lABPl WTEH v. Sci. p, 648; Proc, Cal, &cad 8ri. ill, p. 212, An unusual character in ihi> II, prettil' ci.- is that the sutural hmiin.-e iitly con; jiiLral sinus] l»y a layer liniiiLr tin- very bl 'Indt'nfn'H* [ dtntient to (>' i-oun'at. Sci. Phila. 1865, p. 60. A variety i'rom Catalina Is. has the posterior valve with 7, inter- mediate 1 . anterior 8 slits, the mucro less anterior ; divergence 90°. (Opr.) I. LIVIDUI Middendorff. PI. 6, figs. 22, 23, 24. Shell elevated, teL'inentum smooth, shining, livid. Anterior valve, lateral areas and posterior valve obsoletely radiately ril>- stiiate. Central areas longitudinally costulate, the riblets sepa- rated, .-harply cut, whitish, 18-20 in number. Lateral areas depressed. (Jills median. Length 23 mill.; divergence 120°. Sitka. Chiton (Stenosemus) lividus MIDD., Beitr. zu einer Malac. Ros- sica, i, p. 124, t. 13, f. 3, 4. This species and the next have not been found by later observers. I. SCROBICULATUS Middendorff. PI. 8, figs. 66, 67, 68. Shell depressed, tegmentum rough, opaque, ashen or yellow- brown. Central areas regularly pitted in longitudinal series; lat- eral areas swollen, divided by a radiating groove which widens below. Girdle having narrow scales. Gills median, 16 in number. Length 9 mill.; divergence about 130°. California, Chiton (Stenosemus) scrobicnlatus MIDD., Mai. Ross, i, p. 127, t. 14. i1. 4-7. I. SOLIDIOR Carpenter, n. sp. Unfigured. Shell small, oval, somewhat elevated, rather flesh-colored; jiifrum obtuse ; niuero elevated, in front of the middle. Valves pointed, a little rounded at the margins; lateral areas scarcely defined. Entire surface smooth, under a lens minutely roughened and very minutely punctate ; wrinkles of growth conspicuous. hind.-: posterior yalye with 9, anterior with -s, median with 1 slit; the teeth obtuse, solid, much separated, at times somewhat roughened. Sinus wide, flat ; caves *h<>rt. (iirdle normal I'm- TrnrJiiidr,-ni»n, the granules solid. II \« >• Illl' This is the only tropical Bpecief th:it I have met with, ami very ;ii>n.)i-in:il in \\< itumpy projecting teeth, re0embliog tbote of Tnnif,-//ii. The girdle IB, however, normal, tin- extremely nil crowded granules present ini: :i s«.me\\ hat hri.-t I \ . the mirroseopi'. The above is taken from Carpenter's Jtfft Thety] oen is Miis. ( 'iiiiiin-, N<». !()/>. I. \>IM:IM«>I: Carpenter, n. sp. I 'nfn/ured. Shell small, oval, depressed, the juirnni acute. Valves apicu- late; ashen, maculated with darker. Mucro rather raided, the posterior slope concave. Kntire surface under a l<-n- §een ' conspicuously j)iistulose ; central areas havinir ahout 7 suhparalle] lines of small but projecting granules, bending toward tl:e jiiiruin, closer on the jugal area. Lateral areas hardly elevated, ha about 3 very distant and a little larger lines of granules; anterior valve with about 18 such lines. Interior: anterior valve with 8, central valves 1, posterior valve with 9 slits; teeth acute, long ; eaves conspicuous, short ; sinus nar- row, deep, laminated but scarcely dentate. Girdle thickly beset with most minute purple smooth scales (and occasionally corneous hairs, perhaps foreign to it). Length 1H, breadth 7* mill. ; div. 140°. Eaxt .' Trochydermon asperior Cm., MS. p. 19. The solitary specimen was found in a mixed group of species, named C. pulcherrimus Sby., and Lept. craticulatus by Dr. (iould, and coming from either Hong Kong or Hakodadi. It will be easily recognized by its* sculpture and minutely chaffy s< ; Whether it belongs to this genus or to C/urtopleura will probably be decided by the gills. (Cpr.) I. PERORNATUS Carpenter, n. sp. Unfigured. Shell, small, subelongate, elevated; jugmn acute; ashen or olive maculated; mucro slightly before the middle, planat.-. Central areas with subparallel strong tuberculate bars, about H) mi each side, interstices decussated; jtiLral urea granulate, sculptured in front; lateral areas strongly defined, having rounded irregularly radiating tubercles, of which there are around the margin of the posterior valve about 20, the median valves f>, anterior val\> 78 ISCHMK I II TON. Interior: anterior and posterior valves having 7 slits, median valves 1 slit ; teeth a little acute, eaves large, pectinated by the t ul »ercles or little bubbles of the outer .surface; sinus moderate, deep, flat, smooth. Girdle closely beset with rather flat, subpilose, minute scales. Lemrth 1">, breadth 7-1 mill.; div. (.>">°. Habitat >/?// Ttchydermon perornatus CPR., MS. p. 19. Congeneric with asperior, but easily distinguished by the very >tr"i)Lr sculpture, flattened mucro, yet sharp elevation of the .shell. '••) 1. VIRGATUS Reeve. PI. 8, figs. 72, 73 (enlarged). Shell oblong-ovate, minute ; valves smooth, or under a lens very finely reticulated; beautifully mottled and striped with bluish- green and yellow\ Ligament very minutely scaly, marbled. (JRve.~) Port Lincoln, Australia. Ch. virgatus Rv., Conch. Icon. t. 28, f. 192, ISl&.— Trachydermou virgatus Rv., CARPENTER, MS. p. 22. — Ischnochiton virgatus Rv., CPR., MS. p. 106. ( 'arpenter writes as follows of the type specimens : Two speci- mens, Mus. Cuming; minute, length 5, breadth 2 mill.; div. 85°. Shell very arched, the jugum rather obtuse but not very. Mucro elevated, the posterior slope slightly concave. It looks externally like the young of lentiginosus, being painted in the same way- olivaceous with bluish-green spots. Girdle tessellated with *mnll scales not striated; granular. The three areas are scarcely to be distinguished. Very conspicuously quasi-granulate all over. The juirular part is partially streaked with brown in one specimen, blotched with ashen in the other. The anterior valve has D, central valves 1, posterior valve 9 slits. Teeth sharp, few, long. Eaves moderate. Sinus broad, moderate, flat, not channelled. I. YIRESCENS Reeve. PL 8, fiir<. 71, 75. Shell ovate, valves smooth, crenulated along the posterior edge ; bright pale green ; ligament horny. (7?r.) JIahitaf mil:/' Chiton rh-escens REEVE, Conch. Icon. t. L'o. f. j-ji;, May. 1847.— "ft Tro'-Inj.hnnon n'rescena" Cl'R., MS. p. 21. i! Norn I ! . ( larpenter'e aotei are as toll.,- CiiiniiiL'-. A very remarkable ipecies, \\iili M combination of characters. IVrhap- it belong- rather win etO, Valves rather pointed in limit, and broader behind ; oval, -omewhat elevated, jiiguni rat her .-ha rp. (in-ni, uitli one OF more valves always varie-ated with darker; line N's.-dlati..; suture-, causing it to appear toothed. Muero rather rai- • anterior third ; posterior >h>pe very concave. Valves rath' ; with conspicuous, rat her obtuse apices. Side areas scared v di-tinct. 'The whole surface is rat her glossy, hut under the niirrosropr uitli extremely line .irranulation, which runs into line lines alon- ami near the juiruni. ( Jirdle Trachydermoid, covered with extremely minute scales and occasional hairlets, but at the sutures and in a row around the margin are a series of brown dots which turn out to be semi-pores, quite regular but without hairs, only lar.Lri making a kind of knob. They are very conspicuous as pore-lumps when the shell has been soaked. The anterior valve has 11, central 1, posterior 9 slits. Teeth stumpy, like nuttallii, but not striated. Sinus shallow and rounded, with about 16 teeth, formed by the lirations of the anterior part within. Eaves short and very spongy. Length 12-1, breadth 7 mill.; divergence 113°. I. STRAMINEUS Sowerby. PI. 8, fig. 71. Shell ovate, smooth, pale straw-colored ; back rounded ; marginal scales sparse. (Sowb.~) Length 10, breadth 6 mill. Island of Chiloe, under stones at low w Chiton stramineus Sows., P. Z. S. 1832, p. 104 ; Conchol. Illustr. f. 28; Zool. Beechey's Voyage, p. 150, t. 41, f. 13.— Trachydermon straminens Sowb., CARPENTER, MS. p. 21. Carpenter remarks : A distinct species. Five specimens in Mus. (aiming, much worn and smashed. They scarcely show the sculpt- ure ; in the best there is an attempt at granulation. Rather broad, flat, rounded jugum. Girdle gravelly; mucro median, a tritle raised ; posterior slope nearly straight. The anterior valve h:i- median 1, posterior 10 slits; teeth sharp, Isehnoid ; eaves mod, Length 1H, breadth 7 mill.; divergence about 114°, the valve- rounded. 80 [SCHNOCHITON, I. PUSILLUS Sowerby. PI. 8, figs. 69, TO. Shell small, obovate, whitish ; back elevated : intermediate valves narrow, very minutely punetulate : lateral areas somewhat distinct ; posterior valve larger, the apex central, inclined backward. (Sowb.) Length 6i, breadth lM mill. Hirnminnio, J'fi'ii, on a coral reef in 17 fins., 0 miles from shore. C. ;>M. M \. 1'iiciiir t. Nat. xii, j>. 1 1 <»7.— L»>\\ i:, Zool. Journ. ii. p. 101, t. 5, f. 2.— (Jon, i), Invert. Mass. p. 1 111, f. '_' 1 : edit. IJiimey p. 1M50, f. 523.— FORHKS& HANI.KY, IIi>t. Mull. (i. I;, ii, ; 59, f. 6; t. AA, f. 6.— HANLKY, Sh. ,,f Linn. p. 17. SoWEBBTj Coiu-h. Illnstr. f. 103, 104.— RKKVE, Conch. Icon. f. 175.— JEF- i IM.YS, Brit. Conch, iii, p. 224 ; v, p. 19!), t. M>, f. 4. — Ch. cinereus ( ). F.vi;u., I-'uiin. Clronl. p. 423, not of authors nor of Lin IK'. — Ch. minimum SIM-:NVI;N, Ind. M.dl. lit. Scand. p. 28, 1846, not of Mont., Forbes & Hanley, et al.— Ch. Ar/'/'x I'KNNANT (probably), Brit. Zool. (iv), iv, p. 72, t. :U\, f. 3.— Ch. latus LEACH, Moll. Brit. p. 231. — Chiton (Lepidopleurus^ruber JEFFKKYS, ]>iit. ^Toll. iii, p. 210. — Trachydermon ruber CAi:ri;.\i i .1:. Bull. Essex Inst. v, p. 153, 1873. — Boreouhiton ruber SARS, M«»ll. Reg. Arct. Norv., p. 116, t. 8, f. 4.— TV. ruber DALL, Proc. V - Nat. Mus. 1878, p. 320 (1879).— Chiton incarnatus REEVE, Conch. Icon. f. 194, 1848. The shell is apparently smooth, as described by Forbes and Ilan- ley, but under a high power appears finely reticulated as observed by Jeffreys. Its color is very variable, being usually marbled red and whitish like Tonicella marmorea, but the valves may be uni- form dark red or nearly pure white. I have one specimen with the four central valves dark red and the rest white ; one valve in a specimen is often dark red, while all the others are marbled. It is most likely to be confounded with Tonicella marmorea and - varieties of T. liueata, both of which have leathery girdles, while this species can almost always be determined by its farina' girdle, dusted with alternate red and whitish patches, the latter nearly opposite the sutures. (Dall.} I. PUNICEUS Couthouy. PL 8, figs. 76, 77. Shell small, thin, elongated, elliptical, elevated and sharply ear- iiuited along the back, of a dull rose, or bright brick-red color, and 6 ISCIINorliri' everywhere minutely punctured. The lateral areas are vn-y abruptly and distinctly elevated, regularly ridged by the obtusely rounded stages of growth and bearing a lew scattered granules. Central areas with the lines of increase well marked, and remark- ably barred with about six elevated, longitudinal, parallel ridges, which are generally dislocated about the middle by some of the lin.-s of increa-r. The posterior valve has a very minute, and acute, nearly central nmbo, with an abrupt depression pas-im: transversely through it; the margin is very minutely imbri- cated by prismatic scales, colored like the shell, and with yellowish band- ending it, opposite to the junctures of the valves. (G/c?.) Length 12$, breadth 7'. mill. Orange Harbor, Terra del Fuego. Ch. j>n,i!rrns (CouTHOUY MS.) GOULD, Proc. Bost. Soc. N. 11. ii, 1846, p. I-}-0.: Exped. Sh. p. 5; U.S. Expl. Kxped. Moll. p. .°>24, t. L'7. f. 412; Otia Conch, p. 5. — Trachydermon ruber var., CAKI-I N- TER MS. — Lepidopleurus puniceus ROCHEBR., Miss. Sci. Cap Horn, Moll. p. 140. The gills extend forward to the middle of the foot. They are erroneously represented upon Gould's plate. Carpenter considered this a synonym of T. ruber, but it is probably distinct. I. STKINKMI Pfeffer. PL 6, figs. 19, 20, 21. The form of the animal is a somewhat elongated oval, bluntly rounded before and behind, the middle keel-like and elevated. ( Jirdle covered with granules which are somewhat elongated in a radial direction. Eighteen gills on each side, reaching from the middle of the foot nearly to the posterior end. Shell rather elevated, very finely granulated. Median valves comparatively narrow, their length not much over 1 of their breadth, the posterior angles not produced backward; yo: examples having strong, acute apices, older having less projecting blunt apices. Lateral areas separated from central ana- by a dis- tinct ridge. Central areas having transverse lines of fine grains, which turn at right angles and become longitudinal on the lateral areas; there are also more or less terrace-like marks of growth- arrest. There is a system of weak radial wrinkle-stri;e, converging toward the timbo. upon the central areas, more developed in young specimens, and totally absent in the larger ones. Anterior valve half-round, concentrically finely granulated, and having coarse con- ft HWO in i erntrir growth-mark-. Tail valve hall'eimilar. || -eulptiired likr the head valve; it- mitral area from than .' die length «.f die posterior slope. I'mbo aeut»- examples. The insertion plates are nil overhung l»y the eaves, th< Ia1 jectiDg beyond them. Tin- ;uit< -rii.r valve has 17, posterior valve \'2 teeth. The ground color of the shell baa a light reddish-white or hril- liant red tone, with more or less distinct radiating flamed ro\vii, lighter toward the edge, with i'cw or numerous transverse tracts of lighter. / L.-ngth 2b", breadth 14 mill. South steinenii PFFR., ^Foll. von Siid-Georgien, in .Juhrb. Hand). Wiss. Anstaltcn, iii, p. 103, t. 3, f. 1, 1886. Closely allied to T. puniceus, but different in having the central and lateral areas equally granulated, and the central area entirely without longitudinal sculpture. Section Trachyradsia Carpenter. Trachyradsia CPR., MS. — DALL, Proc. U. S. Nat. Mus., Jan., 1878, p. \, 323. Type, C/i. fulgelrum Keeve. Chitons like Trachydermon except that the insertion plates of the median valves have two or several slits. The species of this group should be carefully compared with CalMntnn. and Stereochiton, with which groups they agree in the multiple slits of the central valves and the markedly spongy ea I am not disposed to group these forms with Trathydermon but leave them here in deference to the views of Carpenter. It should be noted that Carpenter did not consider Ch. fulgetrutn the tvpe of his group, that species having been selected by Dull. I. PULQETBUM Reeve. PL 8, figs. 80, 81, 82. Shell ovate, a little attenuated in front, very minutely and doe decussately punctured under the lens, throughout. Terminal valves and lateral areas of the rest somewhat ohscmvly radiatrly grooved. Reddish-brown, peculiarly painted with longitudinal yel- low and black zigzag waves. Girdle horny, (five.) H'thltat tail;/ s I ISCHNOCHITON. Chiton fulyetrum ]Ji:i:vi:, Conch. Icon. t. xiii, f. 71, March, 1847. — / Ti'itchijrmlt'm fulgetriim CPR., MS. p. 24. — ? Chiton dental us, SPENGLER, Skrivter af Naturhistorie-Selskabet, iv, p. 88, t. 6, f. 16, Kiobonhavii, 17(.'7. Carpenter writes as follows of the type specimen, unique in the Cuming Collection : The mucro is prominent and median, the slope In-hind it very concave. The interior is vivid rose color. The insertion plate of the front valve has 20 slits, median valves 4 to 5, and posterior valve 18 slits. Sinus small, imperfect in each valve, but probably as shown in fig. 81. Eaves small. Girdle thin, wide, ornamented with small, scarcely imbricating, slightly elongated, very close, deciduous scales. Length 63, breadth 38 mill.; divergence 103°. The scales are extremely minute deciduous, crowded into an irregular spongy mass, and when seen separately are not like a flat spine as in Callochiton, but somewhat rectangular and scarcely elongate. They have perished over most of the specimen, although that is in fine condition. It appears to have been tessellated with white over the chestnut surface but most of the specimen is now of a light horn color. The radsioid character of the valves and the brilliant rose interior makes this specimen very like castaneus but it is known outside by the obsolete riblets formed by slight depressions co-ordinate with the slits inside. Even these do not appear in the younger part of the shell. The color markings are probably vari- able. It is probably from S. Africa. (Q?r.) I. ALEUTICUS Ball. Unfigured. Shell small, rufous-ashen, oblong, vaulted, the jugum very acute; mucro submedian ; apices prominent ; lateral areas inconspicuous, entire surface minutely reticulated in quincuncial pattern. Interior: anterior valve with 16, central with 2, posterior with 11 slits; teeth small, very spongy, widely separated ; eaves spongy, sinus small. < Jirdle beset with minute scales. (Dall.) Length ('., width 3 mill. Kyska Harbor, Kyska Id. ; Constantine and Kiriloff Harbors, Amchitka Id., and Nazan Bay, Atka, in the western Aleutians, at low- water mark, under stones on the beach. Trachyradsia aleutica BALL, Proc. U. S. Nat. Mus. p. 1, Jan., 1878 and t. c., p. 323. 1 1\«. ••nirow. 85 This modest little species is of a dull livid purplish red, with an aahy tinge, especially on the narrow girdle, Kxcepi r,,r th<- weii- marked ridges of growth, it appears SIIMM.||I, hut pOWeMet ' like all Chitons) a fiiu> reticulation, only vi>iblc under a. maLMiit, lateral areas are not distinct, the back is very much rounded and the valves well hooked in the median line. The substance of the valves from within appears remarkably spongy as if rotten, or even like vesicular pumice, especially under the eaves. The ante- rior slits are marked by radiating lines of holes, though the teeth between them can hardly be made out. The posterior valve, how- ever, has not this aid to counting, and in the general spongiin is almost impossible to say how many teeth or denticles exist. It bears no marked resemblance to any other species of the region. (DalQ I. MULTIDENTATUS Carpenter, n. sp. Unfigured. Shell small, reddish-ashen, oblong, vaulted, the jugum very obtuse ; umbo of the last valve submedian ; apices prominent. Entire surface having the appearance of being minutely scaled in quincunx ; lateral areas scarcely distinguishable. Interior having 20 slits in the posterior valve, 2 or three in the intermediate valves ; teeth small, solid, obtuse, deeply and broadly separated ; eaves short, spongy ; sinus small, very wide, scarcely laminate. Girdle beset with minute scales. ( Cpr.~) Bonin Islands (Stimpson). Trachyradsia multidentata CARPENTER, MS. p. 24. The type is in the Smithsonian collection. The only specimen known has lost its head valve, and most of the mantle scales; what remain of these, however, are of the Trac/u/- dermon rather than the Callochiton type. The shell was named Lepidopleurus lepidus by Dr. Gould, but has little in common with that species. There is no character to distinguish it by outside ; but within the incisors are represented by a series of roundish, stumpy, peg-shaped denticles, set rather widely apart in the short spongy gums that are characteristic of Callochiton. The three or four lobes in the side valves are rather longer. I. LINDHOLMI Schrenck. PI. 27, figs. 35, 36, 37, 38, 39. Shell ovate, about twice as long as wide, depressed ; olive-green, the eroded umbones rosy-white. Lateral areas and end valves 86 I-i 'UNIX IIIToN. racliately costulate, decussated by concentric growth sulci, the rib- It -ts more or less scaly-gran ose, the interstices very delicately punc- tate. Central areas longitudinally wrinkled, the interstices deli- cately punctate. Mucro sulx-entral. Anterior valve having 16, median valves 4, posterior valve 12 slits. Sutural plates yellowisli- rose color. Girdle half as broad as the lateral slope of the valves, very delicately granulose, blackish-green maculated with white. Gills ambient, composed of 44 branchue. Length 44 mill. ; divergence 130°. Bay of Hakodadi, Chiton lindJiolmi SCHRENCK, Bull. 1'Akad. Imp. Sci. de St. rsb. v. p. 511 ; Melanges Biolog. iv, p. 253; Reiseu u. Forsch. im Amurlande ii, Zool. p. 288, t. 12, f. 9-16. This large radsioid species may prove to be a Stenoradsia (see p. 61) ; but the meagre description of the girdle given by Schrenck, causes me to place it, for the present, in the decidedly heterogenous group Trachyradsia. « Subgenus VI. ISCHNOCHITON Gray (restricted). Ischnochiton GRAY, P. Z. S. 1847, p. 126. — SHUTTLEWORTH, Bern. Mittheil. 1853, p. 66. — Lepidopleurus (part) H. & A. ADAMS, and CARPENTER, olim., not Lepidopleurus Risso. — Ichsnochiton FISCHKK, Manuel p. 880. Valves having sharp, non-pectinated insertion plates ; mucro median or anterior; girdle covered with imbricating scales. Within this subgenus three subdivisions may be recognized : Section Ischnochiton s. s., in which the valves and insertion plates are thin and smooth, one side-slit in each median valve ; the scales of the girdle flat and striated. Section Lepidozona, differing in the convex, solid girdle scale-. which are usually almost smooth. Section Radsiella, like typical Ischnochiton except that there are two or several side-slits in each median valve. The .-nbgenus Heterozona should properly be included here also, and Ischnoradtio is not far removed from Lepidozonn in characters. BOTO in i' .W///or///V (1.) (I'nmj, of I. /oiif/ininih'i. ( )l)h>iiM -.^peril's, with line, not conspicuous, sculpture, tin- central irranulatcd in quincunx <>r in /iir/ai: patt'-rn, lateral areas radially ribbed. The species are from A us( ralo-/elandie seas. I. LONQICYMBA (,>uoy iV (laimard. PI. 22, figs. f>> Shell oblong, rather highly and broadly arched, not in the least carinated. Surface to the naked eye appearing smooth on the cen- tral, radiately lirulate on the lateral areas and end valves. Color extremely variable, usually pale olive mottled with dark olive or purple-black, or having a broad light band along the back. Lateral areas distinctly raised, sculptured with 8-12 radiating riblets, often bifurcating, the intervals densely granulated ; the rib- lets are interrupted by irregular impressed concentric growth-line-. Central areas very closely and finely granulated in quincuncial pattern ; the granulation is nearly even on the jugum, although the anteriorly divergent rows of granules are sometimes slightly more prominent ; on the slope between central and lateral areas, and <>n the extreme sides of the latter the granules are arranged to form more or less distinct longitudinal rows. The end valves are verv minutely granulated and radially lirulate. Umbo of posterior valve rather low, obtuse; posterior slope visibly concave. Interior green or blue sometimes varied with red or corneous. Anterior valve with 9-12, central 1, posterior valve 11 slits; teeth thin, sharp and smooth ; posterior tooth of the side insertion plates short, and terminating abruptly before attaining the posterior mar- gin of the valve (figs. 61, 64) ; eaves solid. Girdle closely covered with solid, convex but somewhat flattened imbricating scales, most of which are rather weakly striated, but among which non-striated scales are mingled (pi. 22, figs. 63, 66). Length 33, breadth 16 mill, (often smaller). New Zealand: Auckland to Duned in ; Pitts' Island; Auckland Is.; Campbell Id. C. longicymba (? Dufresne, Mus. Paris; Blainville. Diet, des Sri. Nat. xxxvi, p. 542), Qn»y A- < IAIMAMD, Yoy. de PAstrol. Xool. iii, p. 390, t. 75, f. 1-18 (1834).— Hi EVE, Conch, [con. t. !'.», f. 126, t. L'4, f. 163d. — Lepidopleurus lonyiciimbtm Hni<>\. Man. N. /. Moll. p. 113(1880). 88 ISCHNOCHITON. There is no certainty in the identification of de Blainville's lovgi- cymba but I have accepted the form recognized under that name by (v)iioy, as he was the first to figure the species. This identification coin pels us to regard the New Zealarfd shell as the type form. Figures 58, 60-66 represent New Zealand specimens furnished me by Prof. Hutton and Mr. G. W. Wright. These differ from the Australian form, which I have named Haddoni, in the much less distinct, less regular striation of the girdle scales, the broadly rounded arch of the back, and the short, abruptly terminating posterior tooth of the side insertion plates. I. HADDONI Pilsbry, n. sp. PL 22, figs. 67-73. Shell distinctly keeled on the back; scales of the girdle beauti- fully regular in size and arrangement, and evenly and deeply grooved (fig. 67). Sculpture and color patterns like /. longicymba. Interior white, greenish or bluish ; anterior valve with 10, cen- tral 1, posterior valve 12 slits; teeth thin, sharp. Posterior tooth of the intermediate valves long, extending almost to the posterior-lat- eral angle of the valve, and not terminating abruptly (fig. 72). Length 27, breadth 12 mill. The coloring is even more variable than in the New Zealandic /. longicymba ; some specimens are clear, light greenish-buff (fig. 71) ; some are brown, speckled all over with olive-black ; some are mainly red, or black, having a wide white dorsal stripe. Port Jackson, Australia. Chiton longicymba So WEBBY, Conchol. Illustr. f. 67. — REEVE, Conch. Icon. t. 24, f. 163a-c. — Ischnochiton longicymba CPR., MS., and of HADDON, Challenger Rep. Polyplac. p. 17 (not Ch. Imtgifymba Quoy). Having examined extensive suites of specimens of the longi- cymba type of Ischnochitons from New Zealand and Australia, I find myself compelled to separate specifically those from the latter locality, although in general appearance, color and sculpture they certainly resemble the true longicymba. The differences indicated above, and shown in the figures, seem to be remarkably constant, and readily recognized if one takes the trouble to look for them. It must be admitted, however, that to thoroughly examine a small ( 'hiton involves some little trouble; and therefore we must feel no surprise if the superficial collector and the often no less superficial author, continue to confound species which are really distinct. It ft IIMM III l< must be said, however, that the confusion of these two ip probably been due to the hick of specimens from the two localities for comparison ; else the dilli-rcnccs would hardly have escaped writers so careful and observant as Carpenter and Iladdon. I. CRISPUS Reeve. PI. 24, figs. 98, 99 (enlarged). Shell rather elongately ovate; terminal valve- and lateral areas of the rest finely decussately granulately crisped, central areas smooth, or under the lens very minutely reticulated. Olive-green, thickly painted with dots of a darker color. Ligament minutely grauulously coriaceous, obscurely tessellated. (Reeve.) Australia. C. crispus EVE., Conch. Icon. t. 19, f. 120, May, 1847. Allied to C. longicymba, but distinguished from that by the min- ute decussated character of the sculpture of the lateral areas. (Eve.) Carpenter seems to think this simply a pale variety of C. longi- cymba, saying that he cannot see the decussation spoken of by Reeve, unless it is from the concentric ribs of growth seen in some of the specimens. In view of the inadequate description and figure, the species had better be dropped. I. PALLIDUS Reeve. PI. 23, fig. 91 (enlarged}. Shell oblong-ovate, valves smooth throughout; dead white; lig- ament horny, arenaceous, brown. (Reeve.} Australia. C. pallidus REEVE, Conch. Icon. t. 16, f. 92, March, 1847.— Isch. pallidus CPR., MS. Carpenter's notes on the specimens in the British Museum are as follows, but I am not sure that these are Reeve's species : Shell almost exactly like L longicymba, gothic-arched ; whitish, ashen, or variously tinged or streaked with roseate, blue and olivaceous ; jugal area scarcely defined, jugum obtuse ; central areas wrinkle- striated, the wrinkles irregularly tending forward toward the jugum, sometimes v-shaped; lateral areas well-defined, having 12-30 gran- ulate-wrinkled stride, sometimes the wrinkles, sometimes the gran- ules predominating, sometimes having concentric growth wrinkles. Mucro median, rather elevated, the slope behind it little concave. Interior : front valve with 11, central 1, posterior valve 13 slits ; teeth '.«) ISCHNOCHITON. acute ; sinus very broad, flat ; eaves large, scarcely spongy. Girdle thin, irregularly imbricated with very small, very close, solid, sub- elevated, conspicuously sulcated scales. Australia. Five speci- mens, P>. M.. the tablet including two specimens of longicymba and one of Heterozona cariosa f. In the first specimen the radiating sculpture is almost lost in the i:ranulc< in the side areas. The painting is sometimes with delicate broken lines of brown longitudinally. Sometimes one jugular patch more or less broken into streaks, side areas rarely if ever painted, but often tinged with bluish green. The specimen opened B. M. has 2 central teeth on posterior valve changed into an irreg- ular series of pectinations evidently consequent on an injury. I. INQUINATUS Reeve. PL 18, figs. 49, 50 (enlarged). Shell oblong-ovate ; terminal valves and lateral areas concen- trically, somewhat obscurely ribbed, finely radiately grooved; cen- tral areas longitudinally finely ridged. Ligament horny, arena- ceous. Whitish, stained with a light brown spot along the summit of each valve. (Rve.} Tasmania. C. inquinatus RVE., Conch. Icon. t. 23, f. 154, May, 1847. — Isch- nochiton inquinatus CPU., MS. The shell is sometimes partially stained throughout with the faint brown color which appears on the umbonal summit. (Rve.) Compare /. divergens Rve. I. DIVERGENS Reeve. PI. 22, figs. 74-77. Shell oblong, moderately elevated, varying from obsoletely to distinctly angled at the dorsal line. Lateral areas raised and rugose. Color very variable, but usually a light green tint, spotted with dark olive-brown, or cream-white, variegated writh olive, olive- brown or dull scarlet. The raised lateral areas are sculptured with a varying number of bi- furcating or irregular riblets, the surface between them being granular. Central areas sculptured in the middle with very fine subgranose strice diverging forward /\-likefrom the dorsal ridge ; pleura or sides of the <•< ntral areas having stronger longitudinal rugce at the sides and on the diagonal slope ; a region of fine zigzag striation sometimes inter- vcninir between the side corrugation and the A'like >t nation of the jugal tract. End valves sculptured like the lateral areas. Umbo i~< n\'M 111 1. :u of iln- posterior valve rather acute, in front of tin- middle : slope concave. Interior whitish or bluish, marked at tin- >inns \\itli 1>1 and posteriorly with rose ; the tail valve haviirj a conspkmooi Nark crescent in the middle. Anterior valve having l<> ll;. central 1, posterior valve 10-13 slits; teeth sharp; cave- narrow, -olid. Girdle indistinctly tessellated with purplish on a paler Around, covered with forge, convex, closely and deeply ftriaUd 9oM -• (fig. 74). Length 28, breadth 14 mill. Port Jackson, AurtraKa. Chiton diver gens REEVE, Conch. Icon. t. 8, f. 44. — Ch. proteus REEVE, /. c., t. 18, f. 111. — Lepidopleitrus proteus ANCAS, I'. / 8, 1867, p. 222. — Itchnochiton divergens and Inch, proteus CPR., JA\. Isch. intricatus and Isch. intricandus CPR., MS., olim. * This species differs from I. longicymba, haddoni and //•/// /ra*t/.>- in the very much larger convex scales of its girdle. It has the lateral areas much as in I. fruticosus, but the median portion of the cen- tral area is more distinctly patterned, and the jugum is subcar- inated. It varies greatly in coloring, and usually has some roae- pink inside. /. divergens has been erroneously united to fruticosus by Angas and by Haddon. It should be understood that all of the detail drawings of the girdles are drawn to exactly the same scale; if this be considered, the student need not hesitate in identifying the pres- ent species. I. FRUTICOSUS Gould. PI. 23, figs. 78, 79, 80. Shell oblong, moderately highly arched, the back rounded, not carinated. Surface lusterless and showing distinct, irregularly radiately roughened lateral areas. Color usually grayish or light green, becoming olive-green or brown toward the sides, and more or less spotted with blackish. The lateral areas are raised and irregularly sculptured with a varying number (3-6) of bifurcating subnor radiating riblets, the posterior one of which is transformed into a series of nodes; the other riblets often much interrupted (fig. 80), but sometimes nearly continuous; intervals between the riblets are finely granulated. The central areas are either minutely and evenly shagreened in the middle, much as in /. lonyi- cymba, except that the granules are more distinctly arranged into 92 ISCHNOCHITON. oblique zigzag rows ; but toward the sides of the central areas, along the diagonal slope, a coarse sculpture of longitudinal wrinkles is developed. End valves sculptured like the lateral areas; umbo of posterior valve rather obtuse, the posterior slope concave. Interior white and blue or blue-green; posterior valve having a black crescent. Anterior valve having 10, central valves 1, poste- rior valve 9 slits. Teeth sharp, thin, smooth outside, but slightly roughened inside ; posterior tooth of the side plates terminating abruptly near the posterior edge of the valve. Eaves narrow, solid. Girdle indistinctly marbled with ashy-purple on a paler ground ; very closely covered with microscopic, deeply imbricating striated scales (fig. 79). Length 33, breadth 15 mill. New South Wales. Chiton ftuticosus GOULD, Proc. Bost. Soc. Nat. Hist, ii, p. 142 (July, 1846) ; U. S. Expl. Exped. p. 319, f. 428 ; Otia, p. 4, 242. — Ischnochiton fruticosus CARPENTER, MS. and of HADDON ? Chal- lenger Polyplac. p. 17. — Isch. sowerbyi n. s. ?, CPR., MS. This species has the lateral areas more roughly and irregularly sculptured than /. longicymba or /. haddoni, and the girdle is some- what more compactly, flatly scaled than either. The external sculpture of the valves is extremely similar to /. divergens Rve.; but the latter differs totally in its very coarsely pebble-scaled girdle. I. SCULPTUS Sowerby. PL 23, figs. 89, 90. Shell subelongate, depressed, subattenuated in front, back rounded. Central areas smooth, striated at the sides ; lateral areas ornamented with radiating exfoliating ribs ; margin smooth. Length 20, breadth 10 mill. (Sowb.) Habitat unknown. C. sculptus SOWERBY, Mag. of Nat. Hist, iv, p. 292, June, 1840 ; < "nch. Illustr. No. 44, f. 66.— REEVE, Conch. Icon. no. 177, t. 26, f. 121. A beautiful little shell, remarkable for the exfoliated sculpture of the lateral areas, on each side of which there are three radiating series of strongly relieved laminae. The central areas are nearly smooth except at the sides, where they are slightly striated. The niaririn i- nearly sm<>oth, li.trlit brown invirularly striped with gray ; and the general color is creamy-white. (Soivb.) EBOHHOCB] i' I. coNTSAcrua Reeve, I'l. 23, figs. 81, g Shell oblong, peculiarly runt ractrd ;it tin- rxhvn especially tin* anterior; terminal valves and lateral tin- rest concentrically granulated, granule^ solitary, central areas very minutely and closely ridded, ridges curved and OOD- spicuous towards the >idcs, finer towards the middle and drni»at«-d with ohli(|iie stria-: light hay, flamed in the middle with hrown ; ligament granosely coriaceous, dark hrown. (live.) TiH*innniii • Mil-. ( 'inn ( '/ilton contractus KEEVE, Conch. Icon. 1. 1^, fi;r. 7*, March, 1847. — (1hiton. (IcciiMttH* RI:I:\ I-;, Conch. Icon. t. 18, f. 107, April, 1> 17. — Chiton rattu* IvVK., t. 22, f. 14-"), May, 1847.— /.>•'•/, n^-hitn,, castus CPR., MS., and 7. interyranosus CPR., MS. — Lr/, ;a. The streaked coloring is quite exaggerated : it is very irregular, not in even lines as in Reeve's figure. The divergence is the .-ameasin 7. castus. Side by side they exactly correspond. The difference i!\«- 111 ! in tin- >inu> is perhaps accidental, from their being older specn "•0 '.h-<:recn, flamed along tlie suiuinit with brown. Rpe.) Australia Mus. Cuming, 1 specimen). < . r,,.liirhtly and very minutely denticulated by the external sculpture; laigc, hardly spongy. Girdle olivaceous, slightly tessellated, imbricated with large, wide and solid, deeply striated scales. Length 21, breadth 12 mill. : irence 103°. (Cpr.,from type specimen.) A n^rnlin. The ireneral characters of this species are the same as in Irstili* and rat'iosus, but it differs sufficiently in sculpture. Both of the two specimens in the Brit. Mus. are curved up so that thev cannot be measured accurately. Another form which Carpenter described in J/N. as " 1. cimtn* n. >p.," but which he afterward decided to be synonymous with wnthut . i> white with a black «rirdle. The shell is much elevated with acute juirum ; the central areas have delicate but much raised lira, about •')<> on each >ide, and subparallel except toward the ridge where they bend outward, and upon the juirum they are elegant! v undulating. The lateral areas and end valves have rather large, separ: rly radiating, serrating the sutures. The anteri<.r valve has 13, central 1, posterior valve 11 slit>. The irirdle U clothed with narrow, stout, deeply grooved scales. Len^tli ::n. breadth \\\ mill.; divergence 110°. It is from Su>«,t /,' MII-. ( 'umini:. No. 100). l-« UN'" III . i> an excellent description of the exterior of this species. [. COLUBBIFEB Kccvc. 1M. L; 1 , tiirs. 51, 52. Shell ohlonu'-ovate, somewhat elevated in the middle. Terminal valves and lateral areas peculiarly flat-drained, cent ral ana- finely reticulated with circular and obliquestlifiB, Whiti.-li l)l«>i. with Itlaek ; li-ament scaly. (Reeve.~) Habit"! »////•/' C. colu In- it')- RKI:\ i:, Conch. Icon. t. 28, f. 188, Jan., 184N.--/.W,- nockiton colubrtfer CPR., MS. Carpenter writes: Three specimens, Mus. Cuming. Very like a yoiini: variety of the castu* group. Shell arched, not keeled, ele- vated ; ashy, spotted with dark here and there, tinged with orange about the umbos, which are not beaked. Central areas, and the undifierentiated jugal areas, covered with a minute granulation, runniiiLr perpendicular to the diagonal line and then brandling off into wrinkles. Lateral areas and end valves having granulations running into coarse concentric wrinkles. Posterior valve bavin- 10, central valves 1, anterior valve 9 slits; teeth extremely sharp and tine; sinus broad, deep, smooth, deeply channelled at the bi eaves long, solid. Girdle having typical Ischnoid scales, rather large, flat, broad, thin, regularly imbricated, very finely striated. Length 16, breadth 7 mill.; divergence about 83°. I. I-ALLIDULUS Reeve. PI. 23, figs. 96, 97. Shell elongated; terminal valves and lateral ar utrieully undulately wrinkled; central areas minutely rough; whitish throughout; ligament horny, arenaceous, whitish. /,' Il'iltit'it n>ik> C. paWidti/iw EEEVB, Conch. IOOD. t. L'O, f. 131, May. ; IscJino'-hifon /Ktllidnliix Crii., .1/N. 96 ilN"< I II TON. Carpi-mer gives the following aotee: Anterior valve with !'. :al valv.s 1 , posterior valve 9 slits; teeth typically Ischnoid ; .-inns deep, broad, channelled, flat ; eaves moderate. Jugum obtuse, elevated; central areas very conspicuously granulated in quincunx. ing somewhat into the Y-culpttiiv : lateral areas c»»nspicinMi>ly raised, concentrically wrinkled, " thuinhy." Mucro central. 7, p. 222. Carpenter briefly notes that the scales of the type specimens an rather gravelly and irregular, very small, but apparently a little >triated. The drawings of scales and valves given on my plate were prepared for Carpenter, presumably from specimens in th»- collection of Mi-. Win. A. Ilaines, of New York City. I. < -A KI NT i. ATUS Reeve. PI. 23, figs. 94, 95. The finely keeled Chiton. Shell oblong-ovate, terminal valves and lateral areas of the rest concentrically and radiately somewhat obscurely ridged and sculptured with obtuse granules arranged in wrinkles, central areas also granulated, smooth in the middle, peculiarly keeled at the summit; ruddy rose; ligament finely squamately coriaceous. (Rve.) T«.hell, the shape of longicymba. Girdle with very small, distincilv but ti n. ly striated scales. Mucro at the anterior fourth. .Ingmn rather ilN'M III I shaip, curiously marked by a long, narrow white line \\i,i, h , he accidental. ( 'flit I II I areas li:i\ 1! granulation! : falling invjuhirly into coi rin:at inn -rain-. Lateral aie;i- moderate! v rai- -I. \siili wrinkling pa.-.-ini: OVer about four very lilunt ob-ohte rib- : end Valves obsoletely radiated. Inieiior: posterior v:il\. 11, mitral \al\vs 1, anterior valve 1 0 -lit- ; teeth sharp, i.in ; sinus broad hut shallow, very -traiirln, -mo^th, not channelled ; eavee moderate, rather close to the teeth. Len-ih LI}, breadl mill. : divergence Id.". . I. CUIMIHVM - I'-. A. Smith. PI. L'l. li-. U lenlai Shell oval, llattish, of a dirty dark irravish color, havini: a • spictious black hroadish line from end to end do\vn the middle of the hack, with a pale one on each side of it, and with the mantle patched alternately li^lit and dark, irregularly granulated through- out. Valvi-s arched, not carinate at the vertex, with verv indi- lateral areas, exhihiting strong concentric lines of growth, e-pecially conspicuous at the sides and anterior maririiis. Front plat*- well curved anteriorly, the posterior margin beini: hroadly sinnat' d. Second plate longer than the other intermediate valve-, sli-htly incurved on each side, the central outcurved point in front, rather peaked in the middle of the hinder edge. The third, fourth, fifth, sixth and seventh valves are very short in comparison with their width in proportion as 1 is to 3. The jngal sinus is large and arcu- ate. Last valve of a narrow acutely elliptic form, with the n prohably near the center. Interior of the plates greenish-hlue, stained dark hrown in the middle. Lt'inina- of in>ertioii in tin- front plate with about ten notches at unequal distance-, leaving diflerent sized teeth between them, which an- ,-tiiated on both .-ides, but more strongly externally, their edges being sharp, but not smooth. The central plates have a single minute notch OH each side, the insertion lamina being Comparatively Miiooth on the upper surface and marked \\ith a small brown spot on each .-id the edge of the valve. Tail plate much thickened \\itliin aloii. posterior edge, which is roughened by fine crOSB stria-, th- no prominent teeth, and of course no notches. .Mantle mar-in cov- ered with small snbimbricating oval grannies. Length without margin l(i mill.; width of fourth plate '.». 98 The granules of the surface have an irregular concentric <1 tiiin, fnllo\\iniLp t<> .-Mine extent the lints of growth. (Smith.) r<>rt Curtis Chit»it i l.3, figs. 85, 86. Shell oblong, small, rufescent, narrow. Intermediate valves hav- ing a very wide trigonal dorsal cariua, the margins grooved : lateral *s distinctly defined. Length 4*1, breadth !•:; mill. (Soivb.) This is the smalleM species Mr. So\\erl>y has seen; the dorsal ke.-| ot' the intermediate valves is very broad, and distinguished l>y OV6 <>n each side. (Sowb.) •d Hood's ItlamI, 7V//mW». <>n Pearl ()y- riu'fnn exigvuiSoWB., P. Z.S. 18,32. p. 104; Conchol. Illustr. f. 36. — REEVE, Conch. Icon. t. 28, f. 186. — Ischnochiton exigwu Ci-i:.. Carpenter writes: Interior: end valves having 14-16 slits, cen- tral valves 1 slit: .-inus wide, curved; girdle irregularly clothed with large, slightly striatulate scales. Habitat, Centm/ I'-n-ifi*- (Pease). Mr. Pease's solitary specimen seems conspecific with Mr. Ciiminir's hitherto unique specimen from Lord Hood's Island. It is in better condition than the type, but extremely minute and evi- dently very young. 2. Group of I. textili*. itral a i-eas granulated, becoming striolate at the sides: lateral areas radially wrinkled. South African species. \ 1 1 us Gray. Unfiyuretl. Shell itbhnnj, e/oHiftite, white, pellucid when younrit.). Cli> \U (-i: \v. Sjiieileiria /oolo^ica, pt. 1, p. ">, pi. (I, f. 20 Muly 1, 1828).— KRAUSS, Die Sndafiic. Moll., p. 38.— (?) I'h.solca UN... Ill I' !•!» .. ( 'ouch. llliMr. !'. HI n»i d.-crihed, RE •////.>•). — Not ( '/i. //•./•//// '.'I . The ahove dc-ciiplio|| is from ' taut panagee hem- italicized h\- on worthless. Keevc's liiruiv and description do n..t pi -rtain to t hi- species, hut to I. (Radsiella) xebra Kran- , true /. •• iii all respects a typical Ttehnochiton, I refer the no d C. mtlt-,1 of Suwerhy to t,.rtili.« becaOM il i- -aid to IK- that tpeckl l>y S,. \vt-rhy hiinsclt'; l»ut the figure i> VTV poor, The detaUl h u'ivcn will enable studenta to identify (H .ith eomj alive ease and certainty, without a figure; for it wemi to he closely allied to the /. oni*<'n.t only ainoiiLr South African < 'Into details of sculpture of the central areas and the coloring «-em to he especially characteristic. Krauss de.-crihe- specimen.- collected hv him, and which he at one time considered a new species which he intended naming C. li«l>r!uhmucro- nate in the middle; intermediate valves having the central areas finely punctate on the ridge, longitudinally striolate at the sides; lateral areas and end valves radiately rugulose-striated. (iiidle a-hi'ii, suhniaculated, scaly, the scales small and ohlonir, > . finely multicn rln ,lits in the insertion plates, which are smooth and shorter than the eaves. The median valves are rather narrow (8'6 x 3 mill.) and have distinct lateral areas with 5 to 6 strong wrinkle-like and interrupted stria-. The cen- tral areas are seen under a lens to be covered with fine raised points, which toward the margins become more and more di-tinct, and near the lateral margins as well as in front of the hit oral areas they unite into distinct longitudinal rows. The sutural plates are rounded; insertion plates short , smooth, and having a single slit. The girdle is covered with extremely small, thin longitudinal » not discernahle to the naked eye, and prettily marki d with 8-9 stria\ The color is whitish in the middle of the shell. Lrrayish- green on the sides, and dotted and llecked throughout with brown. Krauss also describes the following : 100 1-' IIN«»< III 1 Var. jiuni'tn/'ttu. Shell carinated. ashen-wbitisb, unicolored or > d and dotted with brown ; very finely punctate. Lateral areas and end valves radially striated. Length *2'2, breadth 10 mill. Tin- valves are keeled and covered with regularly arranged ..:«-d points only to he seen under a lens. A- an illustration of tins variety Kranss refers to Sowerby's Gout-hoi. Illn.-tr. fig. ">"), but in my opinion this i- not correct. I. OKI8CU8 Krauss. PI. 20, figs. 12, 3, 14, 1 "). Shell small, ovate-oblong, tbin, semipellncid, subcarinatod ; white, rarely with a reddi-h dor.-al baml, or yellowish with green dots. Intermediate valves having the central areas very finely punctu- late in tbe middle and longitudinally striolate at the sides; lateral areas and end valves finely undulately striolate. (iirdle yellowish, mandated with Lrreen, scaly, the scales very minute, oblong, smooth. (Kraws.} Length 10, width 5'6 mill. Natal, on the shore. Chiton oni'tcus KR., Die Siidafric. Moll. p. 39, t. 3, f. 4.—Tschno- chiton oniscus CPR., MS. This species, whilst it has a superficial resemblance to /. text His mill, wide, 4 lon^r, rounded at both .-ides, and having a single slit in each insertion plate. One specimen is white with greenish-brown girdle ; another is whitish with a rod-brown hand along the back ; a third specimen is dirty yellow with green dots, the girdle also green dotted. (Kru< ( arpenter gives this note on specimens received by him from Stimp-nii : Terminal valves having 10- PJ, central 1 slit: teeth acute ; eaves short, spongy ; sinus broad, Hat. In one of the .-pen- men- examined the hind valve has the central teeth very small and close, while the side teeth are long and distant. In] I. YI:I:I;I I:M }•'.. A. Smith. I'l. 1 1. Shell small, depn».-d. >lii) tjcrlntrij'i SMITH, 1'. /. ^. 1891, ]». U<», j,|. n:;, i: (;. Only a single specimen <>(' this species wa- found l»y Major 5 Itury. The sculpture re<-alls that of a thinihle. It i» a trifle coar-er on the lateral, especially aloni: their posterior margins, than on the central areas. The dirty green spotting is also more notic, on the hinder edges of the valves than elsewhere. (Sin I. M vrcii.i.ivRAYi Carpenter, n. sp. Unfigured. Shell elongated, small, elevated, the purum sliirlitly acute, valve- heaked ; ashen-hrown or pale ashen, often elegantly painted with lines or angular flames. Entire surface minutely gran n lose ; lateral areas scarcely defined, having radiating wrinkles, not very distinct. Mucro median, little elevated. Interior: posterior valve having 12-13, anterior valve 12-11, median valves 1 slit. Teeth subacute ; eaves very conspicuous ; sinus wide, flat, smooth. Girdle cl< covered with delicate, subelongated, strongly lirate scales. Length 14, breadth 7 mill.; divergence 110°. Tristan d'Acunha (Macgillivray, Mus. Cuming, No. 74, 92) ; St. Paul's (Mus. Ginning, No. 7). The specimens from the last locality have the teeth acute. This shell has the general aspect of Trachydennoti a/t>u.-< hut is longer, not so sharp at the ridge, more highly sculptured, and tin- scales strongly lirate. The pattern varies greatly in the specii It is nearly related to /. OHI'M-H*, and a larger series of individuals may prove them identical (Cpr., MS.) I. RETICULATUS Reeve. PI. 20, figs. HI, 17. Shell oblong-ovate ; terminal valves and lateral areas of radiately ridged ; central areas rudely and closely reticul;, dull brown ; ligament horny, rouirh. i Heeve.) Wei I 102 l-< IIN(>( HI I • Chiton tcj'titi.-* WMr. Sown.. Condi. Illustr. i'. 01, according to Reeve. — Chiton retimlntu* Rv., Conch. Icon. j,l. ]."">, fig. 83 (1847). — hchnochiton reticulahis CIM:.. .!/>'. Reeve states that this is the textilis of Sowerhy hut not of Gray, and lie i- probably right, although his own identification of text ilia ( iray is erroneous. Carpenter gives these notes upon Reeve's ty pi- specimen : One specimen, which is over-colored and over-drawn in Reeve's illustration. It looks to me like a line textitin, as Sowerby seems to have taken that species, but I have no /<•./•/ ///* by me for comparison. It is very light brown, with little black irregular dots which appear to be adventitious. Girdle typically Isclmoid, with moderate-sized striated imbricating scales. Fine radiating ribs on the lateral anas, very numerous on the terminal valves; honey- combed in the middle ; jugum very much rounded. Anterior valve with 14, central valve 1, posterior valve 12 slits; teeth sharp; sinus very broad and flat, not toothed. Length 303, breadth 16 mill. (Cpr.) Compare textili* Gray, from which this differs in coloration and apparently in sculpture. 3. Group of I. ri**oL Small species having longitudinal riblets upon the central areas, and continuing backward over the lateral areas. These are closely allied to the group of /. striolatH*. Distribution : Mediterranean, African and West Indian. I. KISSOI Payraudeau. PI. 20, figs. 1-7. Sln-11 oblong, elevated, the back regularly arched or snbcarinated, side slopes convex. Surface longitudinally 1 irate on the intermedi- ate, concentrically on the end valves. Color pale brown-olive, the lateral areas and end valves more or less maculated with snow-white and In-own. The lateral areas are moderately raised and sculptured with coar.-e. Hat, uneven-edged longitudinal riblets, which are separated by narrow punctate intervals and are frequently irregular; under a higher power of the microscope the surface appears to be min- utely punctate, the dots whitish. The central area> have cl«»e. line riblets in the same direction, somewhat finer on the dorsal ridge, and giving way to a minute punctation in the region of the beak of HNOCHIT' [00 each valve. The umbo of the posterior val^ ml ami : eratrly elevate. I. Interior white ; >utm-al plates raiftll, -»-p:iratrd id*-, flat siim-. Anirrii-r valve lia\in-_r !•"•. po-in i..r valve Ml tral valves 1 slit ; teeth .-harp; eftVei narrow, .-hurl, -olid. ( ;irdle covered with rl. -mall, Btl ialulale, in scales. Length !•"), breadth * mill. .!/- dit( i i-'ini'tin and A<> r> chiton rtwot I'AVI:.. Moll. Cone, p. 87, t. PiMi.irn, Knum. Moll. Sicil. i. p. 107. — C\ri i IIM, .I«.iiru. iill<'ttim» MalacologlCO Italiano, iii. p. ."», t. 1, t (1870).— MOFTBBOSATO, Journ. de Conchyl. 1*7\ p. 117.— I. I)\i T/.. .\: DOLLF., Moll. Mar. Rouss. p. 495, L 81, t'. 10, 11, 12; t. tt'2. t'. 2. — r/t. mriH't/hinii. CAPKLLINI, Joimi. dc Conchyl. (*2) iii, p. 325, t. 12, f. 1. — Ck. inediterraneu* "Gray MS.," I; >nch, Icon. t. 23, f. ir>7 (1847). This species is well characterized by its flat close concentric rib- lets and the sparsely scattered snowy spots on the end valves and lateral areas. The sculpture of the lateral areas is irregular and variable, the riblets being ragged-edged and occasionally sul> lete, leaving the raised areas almost smooth. The C. />o/ii Phil, is readily distinguished from this species by its difft-ivntly formal posterior insertion teeth ; in ri**oi the posterior teeth are normally Ischnoid. The Ch. mediterraneux of Reeve is simply a synonym of the typi- cal form of this species. The form which Reeve calls risso Icon. t. 19, fig. 122) is a synonym of the variety meneghinO. V&r.meneghinii Capellini (pi. 20, figs. 8-10). Sculpture stronger, the end valves and lateral areas exhibiting distinct radiating stria-. Var. frayill* Monts. (Enum. e Sinon.). Smaller in si/t\ the sculpture obsolete, without trace of radiating stria-. I. PERTUSUS Reeve. PL 20, figs. 18, 1 !>. Shell oblong-ovate, valves elevated in the middle, very cl grooved throughout, ridges of the central areas thin, nm\vr_ towards the umhones, interstitial grooves pricked, posterior edge of the valve serrated ; dark red, sprinkled with a tew minute white dots; ligament horny, very sparingly b«'.M-t \\ith short hri.-tli->. lui BCHNOCHITi Th»- pricked inter-tic, n tin- clo>e-set ridircs which consti- one of tlu* distinguishing features of this species are scarcely :iihle without tlio lens. (Rve.) Simon's /*'nch. Icon. pi. xvi, £ 88 L847).— -IMfioc&t- 1 !•!:.. .l/\ rpenter*s notes from two specimena in tin- Cumin-.: collection areas follow*: The liur'iiv in Keeve doe- nut rcprc-cnt it well. It i- one of the /•/»'»/ irnmp. Shell much arched, elevated, lint the juiruni rather blunt, t'mho of posterior valve raised, situated at the anterior third ; the -lopr hehind it very ,-liirhtly concave, nearlv jht. triated. Color oliv:uvou>, varie«rated. JiiLral area imt deiined from the central areas, which are sculptured with v« TV numerous and line rather blunt liruhe with extremely small inter-ii<'-: <>r the >url'ace ini^lit he described a< finely «rniov« d. ThcM- .-mail rihlets are longitudinal, very slightly «rrai)o.-e, and at the diagonal liordrr of the lateral areas become rupilose, passing on to join with the riblets of the latter, The lateral areas have about '•' to 12 very fine radiating rihlets which are m::de i:ran«»e by the longitudinal riblets from the central areas cro»ini_r them. The end valves have very close and regular radiating rows of Drains, the -culpture bt-inir very like that of C'ltrini/ntii*, but in that species the i-oiic.-ntric wrinkles predominate. The head valve- has TJ slits, median 1, posterior valve !) slits. Teeth quite sliarp, with lonur |>ro- jectiipj; eaves, which are not spongy. Sinus broad, rather deep, flat, -m. .,,th. but deeply channelled on each side at the inner has.snfthe sutural plate-. Terminal valves stained with brownish-purple inside. :li :;•_'. breadth K'.; mill.; divergence 113°. I. i \:\ HII:«>N«>ITS C. ]\. Adams. UnfiV. Thnnin.* ninl r<,,-t<, Him (\\\\\\\\\*>v <. Cli IhronakuC. P.. Ai>., Proo, BostSoe, N. II. lv — 1 . I ;,'»lrliifnn) t'1-iltlii-iniufii* SnrTTI.W., I>eril. M i 1 1 lie! I . ! The pa--a^cs in brack. -i- uf i w<»rt h's Interpolal i' I. i \ 1 1 1:1 1 ii - Shuttleworth, I 'iiiiy Shell clliptical-ohluiij, (-,,nvc\ ; l.i with whitish; end valve- .-iihcuiicent rically HIM -ah- and pun- Mt diiin valve- imt c:i rinated ; c, ntral ft] impn-sed, becoming transversely cottulftt nibmloate at 1 lateral areas suhelevated, radiately snh-ulcafe and minutely punc- tate-foveolate, Girdle unioolored nil. dm^-iv bc-et with minute flattnird icalet, Lrnirtli I L\ l.ivadth H mill. >SI,,,tt/w.) •SV. '/ ln,,» ' . II . (Ifchnockiton) A//r/-/////x Snr'rri,\\., hia-n. n. Mull, in i. Mittheil. 1853, p. 75, I havr nut idcntiiicd this sju-cii s, of which Shnttlcwurth wr. I have two specimens. The color i< an int< -nse l.rick red, l.oth iinide and out. It is allied to ( '. cnjtlirnnntti* ( '. H. Ad., lint ditN-r^ abundantly in toe sculpture and color, and in the 1< .-> elun-at. d shell. 4. (,'rnnji of I. Small species, apparently smooth, hut under a len.- shuwini: a sculpture of longitudinal rildets or lines of grannies on the central areas, interrupted on the lateral areas, which arc niuirlu-niMl hy peculiar irregular impressions (pi. 1*, tig-. 54,55 . It i- difficult to describe the sculpture of the lateral areas of these >[>••« it-- : it i- what ( 'arpenter called " thuinby " or " pollicaroid." Diatribution : Antillean and I'anarnic Sped i'" ii'ifh >•//•/'//' I. STRIOLATUS Gray. PI. 20, figs. 20-24. Shell ohloiig, moderately arcln-d, the hack sometime- distinctly, sometimes scarcely visibly keeled; side slope- convex. SB showing no sculpture to the naked eye, hut having the lateral : moderately di-tinct. Color e\ce--ively variable but generally either olive-green or olive-slate colored with white ur creamy t!- or cream-culoren* l»iu-,'t n tin m (Int. «//••<>' (jiiium /licit be<'tnnr.« *tiyht/y <•«*//•>•/ /• t»u;i,- <•o>terior valve having a moderately elevated, central unilio, rior >loj.c concave. Interior liirht «rray-l)lue or white : ani> valve with !>, central valve 1, po>teri«,r valve !» slits. Teeth .-mooth, >harp. Maves narrow, solid; sutural plates wliiti.-h, rather wide and low: sinus Hat, angular. Girdle whitish clouded with blue, or blue marbled with white, generally having some small yellow or orange flecks. It is densely covered with imbricating, deeply striated scales. (PI. 20, fig. 24.) Length 14 to 15, breadth 8 mill. St. Thom-M*X of Sowerby, all belong to the #fi'iynonyms of /. >//W, unequal ICaleS; n-ntral area! mark -in- 1., ill ill the middi' striale ; girdle I"" illernalt i Length 17 breadth Hi mill. < Ad.) Chiton .tiiininiHlnxti* .\|... ProC, I' Ili-t. ii. : — C. : guamu/Mu* SHUTTLW, I1., i n. Mittln-i: Thia ia unquestionably the same form I havr d< ~nil>< .1 ab The name AtfOmtt&MU* will therefore h»-e..mr ;i C. lutulutti* Shutllw. Shell small, elliptical-ovate. narrower in t'ront ; dull olivaceous spotted with wliih-; tcrniiiiiil valves impressed-punctate, toward the margina irregularly concen- trically Buboostulate ; jugum not keeled; di»i>:il ana- tim-lv and regularly imprCSSed-punctate, and touard the niai'-iii- th'Miondv and irregularly transversely j)lieatulate. (Jirdle olivai-nm- and spotted with white, the >e;,les small, flattened, iml)rieat<-d. L.'ii-jth 1-J, width ^ mill. (Mnttfw.') I ' ' • I Chiton ( I«rh>i<>('hit<»i) lutu/hell lengthened-oval, scarcely carinated, variedly painted, grayish-olive, white, reddish and olivaceous, or purple, sometimes hlarki.-h with white markings; end valves concentrically and roughly gn.' striate or scaly, central areas ornamented with delicate, curved. flexuous, granose lira1; lateral areas roughly . ' mens, when viewed from a distance of twelve indie-. app«-aring olive-grav, speckled with white; others are of a pinki-h en-am color speckled with red or blotched along the; >id« - in front "f tbe 108 ISCIIN'M mi • lateral areas with black, as in some of the specimens from F» -rnando Noronha. Tin- granules or scales of the lateral area and on tin- front and posterior valves are peculiarly Hat and arc somewhat tran>versely arranged on the former and concentrically on the lat- ter. The central areas are finely punctured along the center, and become more and more coarsely grnnoM-ly lirate as the sides are approached. One example is almost entirely reddi.-h purple, and others are blackish with a broad pallid stripe down the middle from end to end. (Smith.) ('/litnn (Itcknochiton) caribbatorum (Yi:., J/.s'.. SMITH, .loiirn. Linn. 8oc, I. 'iid., \x, p. 4(.>o', t. .'{(), f. ~>, 5a. The dimeiiHons given hy Srnitli may possibly he a mistake, for the iark on his plate is only I-')' mill. long. In other respects the description and figures indicate no tangible points of difference from the /. .pec- imens of *t, -io/iit u*. It is worthy of note that Carpenter recogni/ed the specific identity of >7/-/V>A////x, ciiriblm-nrinn, j//>- was COncede.l I iy ( 'urpenter. Lfuniculahu Carpenter. Shell small, strongly oval, suhelevated, the jii'jnm little acute: pale ashen, ochraceous or olivaceous varie- gated: mucro central, moderately prominent. Kntire surface wrinkh-d and minutely pitted: wrinkles >nhregul:»r. nearly j.aral- lel with the d..r-al rid_re on the central areas, ahout 1 x on each >ide, Obsolete toward the jugum j the moderately distinctly defined lat- M and the end valves undulated and having sul)ohsolete radiating liruhe. Interior: posterior valve with 7-i>, anterior valve BNO4 HOT 7 in. central valve- I -lit. 'I wide, ll:ii. ( iirdle lurid-lied \\ ith \ . tened M-ales. Length 10, width .') mill.; di\< (.'iKi'l.l/nllf,,- . Mil ' ( >ne specimen Is of a pale yellowish tint flight]} -I \\iih :i brighter color; another i- in .iv a-hy and \vil li t lie \ : pale olive. h has stronger .-culpture than /. <•//, •//,/,*/•»,,•///;/. ruguhe rising tij) like close rungs in a rope-ladder, and denta' the sutures. ( ( '/»-.') The above deseri|>t ion, from Carpenter1! .!/>. defioei a fonn which will probably prove to he a variety of T.cwil \\hieh species Carpenter, at a later date, united it. I. PBUINOSU8 Could. IM. LM, fitrs. 27, 28. Shell small, elongated, nearly elliptical, convexly elevated, earinate. or rather somewhat doubly carimite alon^ tlie hack : §or« t'aee generally covered with microscopic |)iinetnres, ai-raiiLrfd in lo/.'.-ni:e. Lateral areas very slightly rair-cd, and longitudinally imbricate-sulcate ; central areas with faint line wth and punctures in quincunx ; anterior valve concentrically .-triate, not punctate; posterior valve slightly nmbonate, and rn»-> ed l»y a Iran-verse ridge, behind which it is concentrically Mriate. 1 frosted or mottled with dark brown, ash, purple, green. Are. Mar- gin minutely granulated, so as to look hoary. (Old.) "Some specimens are of a uniform pale green. Margin chmdrd with dark green; some had two or three distinct, white blotch. the sixth valve, the rest of the shell being olive-green, with a line of faint green along middle of back ; another had the ground-colour a clear olive, three dark brown spots bordered with white <>n each side of posterior margin of valves, a row of similar spot- surround- ing the terminal valves just above insertion, and the whole sin sparsely and irregularly spotted in the same way nt a delicately mottled a-pect. A fourth variety wa> of a uniform dark rosr-oilor. and the margin clouded with dark red band<. Inter- nally it was dark red or rosy along the middle, and dull yellow toward- the sides. All the other varie. i greenish hue internally." (Cnnfli. i,, <;! Length 17 '. breadth * ; mill. Off /•''"•' •s'""/" OrVft H'" •/"""''•", "" stone- in 'J or :i t'ms. 1 111 tSCHNCH IIITON. -"v(;M,. I',, Soc, N. II. ii. p. 144, July ls4(J: otia Conch, p. 5, 242; I . S, ExpL Exped. p. 316, t 419.— iiir.iMM, P..lyplax. Cap Horn, p. 141. — hchnochiton pruino- CPB, .V>. p. 77. 103. Carpenter seems to consider this the same as mr'iblxtnm,,, and ' iht* ; hut the specimen before me is too worn to enable me to decide. 1. 1:1 «,! LATU8 S,,werhy. PI. 21. fi--. ~t'\-~n . Shell ohlon.tr, rather smooth, olivaceous varied with white; front valve, lateral areas and posterior valve concentrically unduh;t. Iv wrinkled: central areas smooth, wrinkled at the margins. Length •Jo. breadth 10 mill. Girdle granose. (Soivb.} J'm, -tn r»i-ti->r<> and Inner John* Jil., Centrnl Anit.i'i'-n, under Btonefl :it h»w water. rliltnn rtiiiiil.tttt* Sown., P. Z. S. 1832, p. 58; Concl.ol. Illu^tr. t. !_'. 78, 1 I-. 144 ; Heechey's Voyage, Zool. p. \r>o, pi. 41, fig. 18.— REEVE, Conch. Icon. t. 19, f. 118; t. 20, f. 128, 13:}.— /W/,,,W//7oy, 1-niintnfn* < 'i'i:., MS. ( arjienter describes the interior and girdle from the type speci- ii, .11. tlni-: Posterior and anterior valves having 9, central valves 1 slit; teeth solid ; eaves moderate ; sinus \\ide. Hat. Girdle closely imhricalcd with moderate sized solid scales, scarcely striated. It is very like drinlnln* but havini: stronger sculpture. It goes through all the color variations of lonijicijnilxt. The >cah-s M-I-III to he smooth, but here and there are slight striolations from the dried skin. I. c.\ i i:\ri.ATUS Sowerhy. PI. 21, figs. 47, 48. Shell lonir and narrow, elevated, arched, the jugiun rounded. ( iirdle smooth, broad, thin, with imbricatini: striated scales. Muero central, elevated, the posterior slope >..nn what concave. Central :n. -a- sculptured with very close parallel liruhe, which pa.-s into wrinkles on the lateral area<. which ai'e -wolleii. Mud valve- con- centrically wrinkled. Interior: posterior valve having I <>, «-«-ntral 1, anterior valve '.» >lit>; teeth huiir, sharp, thin ; eaves moderate, not loi)Lr, but well develope»l ; not spongy. Sinus broad, deep, Miiooth. channelled. Length 17, breadth 7 mill.: divergence about L02 . ' Inn, /' /,'.//,,> I.*I,i ml. I9, ,-tl. I-' ll\'.< III 111 •WB., I'. / nch, in,. l 15, REEVE, < onch, [con, t. •_'«., t: 180. / < ri:. MS. The single specimen before me is \vhiii~h, I UJH, brown. tli.- girdle a-hen-hluMi. The >culptui. more like thai «.!' /. th in/.ii,. ..,,,| adorn < thing else, having exactly the same pattern, but not «pntc- The girdle has conspicuously Mriated scale-. The following gpeciee were referred liv Carpenter t,, €i L«-|«i«losterior area of the posterior valve uianu- lous. Girdle grunosc. Length 25, breadth 12i mill. (&•> Inland Saboga, Bay of l*tununn, under .-tone.- on the shore. Chiton d'i*i«tr SIJY., T. /. S. 1832, p. 58; Conchol. Illustr. f — KKI-IVK, (1onch. Icon. t. 18, f. 96. — Not 7,svA//o, -,/,/,,. Cai-penter MS. — Chiton jir<>/»-iit# K.KKVI-:, Condi. Icon. f. lol. — C. picus KKKVK, Condi. Icon. t. 25, f. 121. The name has been suggested by the circnm-tanee of the central areas bein.ir quite smooth, while the lateral areas are covered with granules, i (1. B. Sowerby.') The description given by Sowerby differs entirely from the spe- cies which 1 take to be the /.Wn/o/v/Js/.. and indicates a form very similar to Carpenter's L. r»/>riti* Rv. as follows : One specimen, smashed; " West Coast of America." I>r. A. Sinclair, K. N. This is exactly like the L''jii'l»/i/rni-ii* ii;.«/»ir, havin- lar--.\ smooth scales. Reeve's C. pictu i> also said by Cpr. to be a synonym for /. conspicuously granuloi;- : ftreafl irregularly Ill' KCHNOCHITON, uarted. the warts lohed. Mucro anterior, slightly Interior having tin- central valve with 1 slit, end valves 8-10 slit-. ii acute; sinus flat, very wide. (iirdle imhrieately Length !•">. breadth 7' mill.; divergence 110". < ( )/r.) J'ltHIIIH'1. danuti CIM:.. I*. /. s. 1st;:;, p. 24.— adatnsi* CPB., 1'. /. S. 1866, p. 'J74. Tlie -hells which I have drawn in figs. .">1 -.">."> of pi. 18, seem to me to belong to this species rather than to /. ar. They are described In-low. It must he understood that the more minute sculpture can be seen only under a compound inimpr <>r a very Mul lellS. The shell is oval, rather low, the jugum rounded. >ide->lop. s nearlv straight. Color dark olive mottled with lighter, or having large whitish tracts on some valves; the interior light blue, sutuml l>l4, and at the left side of fig. of). The lateral areas and terminal valves have a coarsely reticulated pattern, formed by impressed zigzag or irregularly lobed impressions, over which a tine granulation extends (h'g. oo.) The interior has 8-10 slits in the posterior valve, 1 in the inter- mediate valves (fig. .">:]). Teeth sharp, smooth ; eaves very narrow. The -jirdle was denuded of nearly all of its scales in both of the imens before me, but such as remain are large, solid. Length 14, breadth 8-] mill. I. TI:M D9CULPTU8 Carpenter. l'nfnjnr«1. Shell similar to I,. « in /.. '/ir.) Panama, Chil'in ili^mr ('. H. A I)., Cat. Panam.Sh.no. 373l part . — /.. />i'ln- kU <'ri:.. P. Z. 8. 18 •'. p. -J7-"). A variety is paler, tinged with rufous at the jugum. l-< I IN. H III I The outside of this shell so much iv-nnMe- id. i/»»/-rs// that specimen- may have ln-« ii distributed m ". Shell ovate oblong, siiHM.tli. roseate; back rounded; front \, and lateral areas of the intermediate valves loiigit mi inally. cent ral areas transversely sulcate ; posterior valve with ctntral ap eentrieallv sulcate. Len-'tli 1 7 ' -, hrcadtli 7 ' mill. fX /. nf J'/titu i ( 'iiniinu ) ; i':>. is-j.")f a species of Acanthochiton). — l*<-lino<-liit<>,> ,-,,*• »/.< < .1/N. — I.«rhiiorh!t»f/i scales, with bristles intercalated at the margin. The sutural lamina- are as .-mall as in /,>/>!»< ; anr valve bavin itral I , . valve !» >lils; teeth .-harp, liiin :in mill. Lengtfc -V. breadth •> mill. JuiH'iini (Adams i ; Murt-n, X» \ l\.»<-. N. II. i^i:>. [..!». — C. ^opi^/oatw SHUTTLW. Hern. Mitthcil. l-s">-'), p. 77.- / l»il>il!n«u« DAI. i., (atal. Mar. Moll. S.-K. U. S., in Hull. :J7, I Nat. Mus., p. 17L'. This is the smallest of our Florida or West Indian I-rlmoid-. It lias much the same sculpture as the small Leptochitons, being uni- formly granulated and having the lateral areas very indistinctly defined. It is readily known from other Ischnochitons by these characters. The original description is as follows : Shell small, wide ; greenish, closely maculated with whitish and black; papillose; areas separated by a slender riblet; girdle very finely scaly, alternately greenish and white. Length 5'25, breadth 3'25 mill. I. ITNCTCJLATISSIMUS Sowerby. PI. 21, figs, oo- Shell oval, moderately elevated, the dorsal rid^u bluntly angular, side slopes nearly straight. Surface apparently smooth, but seen under a lens to be minutely and evenly granulated all over. Lat- eral areas ill-detined. Flesh colored, speckled or dotted all over with light brown, and often maculated on some of the valves or along the dorsal ridge with dark brown. Lateral areas demarcated by a very low and obtuse ridge, obsoletely sculptured by the intersection of two series of obliquely radiating curved impressed lines; central areas similarly sculptured by obliquely longitudinal lines. Umbo of posterior valve in front ot' the middle, the posterior slope concave. Interior bine-white, having 9-12 slits in the end valves, 1 in the median valves; to-ih acute: eaves moderate ; sinus wide, flat. Gird!. 1 with -olid, flat- tened, striated imbricating scales. Length 17, breadth Id mill. Bay* of Callao, Mexill, t. 40, f. 3, 3.— RKKVI:, Conch. Icon. t. 20, f. 129. Tiic typical form of this species is descrihed ahove, and figured on my plate. It is characterized by the almost effaced but even granulation, which is the same on both central and lateral areas, although differing in direction ; by the minutely freckled color pat- tern, etc. Sowcrhy mentions a white variety with a black border and some- what varied with black. This form I have not seen. It has been illustrated by the figures in Captain Beechey's Voyage, H. ^1. S. 'Blossom,' and fig. 9 of the Conchological Illustrations. The latter figure I have copied on my plate. I. IMITATOR Smith. PL 21, figs. 29-34. Shell elongate-ovate, moderately elevated, subangularly arched at the middle, dirty white. Valves narrow, with a single notch on each side, exhibiting small, slightly raised lateral areas, which towards the margin have a few transverse strong grooves or marks of growth. Front margin sloping very slightly on each side from the middle in a posterior direction ; hind margin straight. Sculpt- ure consisting of close flat granulation, exhibiting a somewhat serial arrangement. Lamina of insertion [sutural plates] very thin, with a wide sinus between them. Anterior valve sculptured like the others, with fourteen fissures within, the thirteen teeth between them being sharp and straight edged. Posterior valve with a cen- tral mucro, from which there is a faint ridge on each side to the lat- eral extremity, also marked with concentric lines of growth at intervals and with the inner marginal fissures twelve in number. Scales of the mantle minute, imbricating, ovate, arranged length- wise ; under the microscope they appear very coarsely transversely grooved. Length 11 mill.; diam. of fourth valve f> mill. (Smith.') Tom Bay, Patin/ntiln, on the shore. Ch. (Isrhnor/nt,,,, ) unitotor E. A. SMITH. P. /. S. 1881, p. 35, t. 4, f. 13. 6. Groii/i i if 1. nun i it a*. Surface evenly, minutely granulated, the lateral areas having radiating riblets. (iinlle scale.- nearly -niooth. .Japan, etc. BNOCHTP 117 [. COMPTUS < "Mild. Shell small, thin, cllipt ical ; Lrn-.-n ,,r ~r;iH, t. Ci •.•.|u«-nt 1 y (l(ittc, diani. 10 mill. < Old.) Ootinut, J'l/xtn ; llnn'm uml /,/'//- A'/// /x. /Slim;,. C. (Leptoehiton) wnn/itn* (»<>I:M>, I'roc. Host. Soc. N. II. vii, p. 163; Otia, p. 117.— hch. <'fn« CJPB., J/\ Carjientcr writes: Entire surface punctate; central areas having the lines of points either parallel or bending toward the acute juguni ; lateral areas having small radiating \vrinkl<-s, at fii-t :i \<> \ in number, then splitting into 6 to 8. End valvo havin-j- in deli- cate, hardly apparent radiating wrinkles. Mucro slightly in front of the middle, slightly elevated. Interior: posterior valve with 13, central valve 1, anterior valve 14 slits; teeth acute; • moderate, acute; sinus wide, flat. Girdle having large, solid imbricating scales, sometimes very slightly striated. Length 1 7 , breadth 10 mill.; divergence 120°. Philippines, Mus. Cumin_ 11. Dr. Gould strangely placed this species in Leptochiton. although the scales are as large, solid and regular as in Chiton. The above diagnosis is written from Mr. Cuming's beautiful speci- mens, which are broad and externally curiously like the vein Chiton (var.) patulus. In the typical specimens, the striulation of the scales can seldom be seen, having apparently lived in ex; situations. The variation in color is extraordinary, being (a) densely clouded with olive; (6) light ditto mottled with dark and lilac; (f) four central valves chestnut, the rest olivaceous; (d) brown with olive, with broad white streak down the centre ; (e) light reddish-chestnut mottled ; (/) ditto, shading into oli (0r) sixth, seventh and part of eighth valve dark olive-brown. rest light ashy; (//) the whole light ash. The sutures are alwaya regularly spotted, as in T. jtseudodentiens. In the typical specimen examined there were only eleven slits in the terminal val\ I. LEPIDUS Gould. Unfyured. Shell small, elliptical, roof-shaped, yellow-irreeii >tn-akrd with olive; front valve semi-circular, radially striated; posterior valve crescentric, beaked, radially grooved behind and longitudinally in 118 I-- IINMI mi. P\. . front; lateral arras elevated, sculptured with 6 radiating sulri : central areas imbricatelj sulrate. (iirdle narrow, handed with olivaceous, covered witli minute scales. Length l:J. breadth !» mill. (G7d.) Interior: terminal valves with about 14, central valve.- 1 slit; teeth very acute, but a little serrated at the edge. Haves large; sinus narrow, vaulted, scarcely laminate. Girdle irregularly imbricated with transverse, solid, neatly smooth scales. (Cpr.) China Sea, Lot. 24* N. Chiton (Lepidopleura) !f/n'". 11. vii, p. H>4 ; Otia, p. 118. — Ischnochiton /c/inlus CPR., MS. The girdle scales are those of Lepidopletirus, [—Lepidozona] except that the imbrication is irregular. The species is remarkable for the narrow-, arched sinus; and for the slight serration of the insertion plates which are yet normally sharp and protected with broad eaves. I have not been able to re-examine the type since I matured a plan of arrangement for the sections of the genus. (Q?r.) I. PBTALOIDES Gould. PI. 23, figs. 92, 93. Shell small, delicate, elliptical, roundly arched, very slightly car- inated, the valves not beaked, of a pale lemon-yellow ground color, reticulated along the centre, with delicate, angulated, pale-violet line-: these areas are also rugosely lineate-punctate longitu- dinally, especially toward the margin ; lateral areas very prominent, riiiro-rly granulate, and with about four, fine radiating stria? ; pos- terior valve acutely umbonated and crossed by an acute, tran- rib. Margin cream-colored, very finely granulate-imbi ; (Old.) Interior : posterior valve having 9, central 1, ant. v. 9 slits ; teeth acute; eaves acute, hardly spongy ; sinus very widt •. short, smooth. Girdle imbricated \\ith flat, scarcely striated scales. (Cj>r.) Length 12i, breadth 10 mill. Kan 1 1 1 l OaJnt^ SainhrirJt /.«. C. /»t« /•"''/'>• <1 i.i».. I'r«'c. liost. Soc. N. 11. ii. p. 144, July. lM'i; t . >. Kxpl. Kxped., Moll. SI... p. ::•_' : Otia Concho)., p. (i ; C. (Luciu) pdu/n!if>:< ( \\.\t., ( Mia p. L' 4 '_'.— J.n/Ji tfru.< /xf.i/n!,/, .< 1^1 . Amer. Journ. of Conch, vii, ]». 194. — Itchnochiton i»inln'ti/c of the shell, but thin, sprciiin-n- have sometimes an af>prarancr of minntr >triula- i» ii \< » 111 i 1 1!> tion, from tin- contraction of tin- epidermal film. I >r. Gould mi-"d that tliU ipecitt «mirht t<> lie :i Lucia, i the Pacific Is.; hut it is a normal l-chnochiton in all respects except the non >triation of I he scales. < ( ///•.) I. m-< i i.i-i i > ( 'arpeiiter, n. sp. Shell small, oval ; juu'iim acute; miicro me.lian, rather elevated; :i>hy, maculated with olivaceous. Entire surface minutely gnmu- lose ; central areas having about 10 distant, acute, subparallel lira-, sometimes siih^ranose, the interstices wrinkle-decussated. Lateral areas scarcely raised, ha vim: distant, small, much raised Drains, Mih- radiately arranged in --4 scries, the end valves having 16-20 such series. Interior: posterior valve having 7, central valves 1, ante- rior 10 slits; teeth rather obtuse, roughened but scarcely pectinated at the margin. Eaves small ; sinus small, deep, smoothly laminate. Girdle rather regularly imbricated with decidedly transverse, con- spicuously striated scales. Length 11, breadth 6 mill. ; divergence 120°. (<>/•.) / Hong Kong (Stimpson, N. P. E. E.). " Chiton f pulcherrimus Sby." GOULD, MS. + C. (Leptochiton) craticulatus GLD., Otia, p. 117, pars. (Cpr.). The shells forming the five species, pulcherrimus, craticulatus fcul- tratus, bisculptus and asperior were included by Dr. Gould under the first two names. They need a careful examination of the details of sculpture, as well as of the mantle scales, in order to sep- arate them. Of these pulcherrimus and bisculptus have the striated scales of Ischnochiton ; craticulatus and cultratus, the strong, smooth scales which belong to Lepidopleurus ; and asperior is intermediate between Trachydermon and Cha3topleura. The decided; rugosity of the insertion plates and short eaves of this species form a transition toward Chiton. The whole group appears to have a slight lamina at the sinus, marked off by a slit from the sutural wing. (Qw.) 7. Group of I. interstinctus. Small, finely granulated shells, the lateral areas radially ribbed. Scales striated. Species of the west coast of North America. I. IM KKSI IN. n s Gould. PI. 11, figs. 40, 41 ; pi. 21, fig. Shell OVal-oblong, rather elevated, the dorsal rid;:*1 ohti: keeled, side slopes nearly straight. Surface apparently smooth, but 1-" I-' !i.\carcely perceptibly raised and besides Ix-in- microseopieally punctulate like the rest of the surface thev have low radiating ribs. al)oiit 6* or 7 in number. Central areas evenly punetulate: end valves punetulate and radiately multilirate. I'ml.o ,,f posterior valve in front of the middle, rather elevat. d. Inside: posterior valve with ll\ anterior valve 10, median valves 1 slit ; teeth acute, eaves moderate; sinus wide, flat. (iirdle densely covered with small, suboval, delicately striated* scales. Length \^>. breadth 8 mill.; divergence 110°. Xifk'i ll'irhor mnith t<> Monterey and the Santa Barbara la., Cali- fornia. Chiton interxtinrf,,.* GLD., Proc. Bost. Soc. Bost. N. H. ii, p. ] \:> : M.,11. T. S. Expl. Exped., p. 315, pi. 23, f. 423 ; Otia, p. 230, 2 1_\ —Ischnnr/iit'tH i ,itcr*liii<'tn* Cn:., .1/N. isj)!, and DALL, Proc. U. S. Nat. Mus. 1878, p. 331. This is a small reddish species, characterized by the fine pun ela- tion of the whole surface and the rather coarse but low radiating riblHs of the lat.-ral areas and end valves. The sculpture is not well shown in ( iould's figures. It is drawn from a specimen before me in fig. 39 of pi. LM, representing an enlarged half-valve. I. M:\V( -»MI;I Carpenter, n. sp. Unfigured. Sh.-II small wide, tumid, with obtuse rounded ju<:um. Mucro median, rather elevated. Ashy or olivaceous, ele-antly clouded; central an ;i~ and entire surface -raniilated, the granules being <|uincuncially arranged, close and regular; lateral areas scarcely defined, having abou! 4 lines of tubercles which are hardly elevat. d. Posterior valve having about 30, anterior valve 40 such lino. Inte- rior: posterior valve having 12, median 1, anterior valve 11 slits; teeth acute; eaves apparent ; sinus wide, short, scarcely laminate, (iirdle imbricated with large striated and rather regular s-ale>. Length 83, breadth f the middle, .-eareely elevated ; entiiv >ur- face quincuncially granulated ; lateral areas scarcely defined. ;u,d with the end valves ohsoletely sublirulate. Interior: pi,.-t- valve having JMO, central valves 1, anterior valve ID 11 slits; teeth acute; eaves small; >imis wide, short, scarcely laminate. Girdle regularly covered with solid, coarsely striated, moderate sized scales. Length L'l, breadth If) mill.; divergence 110°. (( ', Monterey, Cnlijoniin. The internal color-rays are seen in all the dead valves; the external painting resembles Mo/xtl'm vespertina. The sculpture is on the plan of/, mterstinctus. One central valve of one specimen, on one side only, had a second slit. (Q>r.) 8. Group of I. scabricostatus, I. SCABRICOSTATUS Carpenter. Unfigured. Shell small, orange colored, elevated ; valves gothic arched, jugum acute. Entire surface very closely granulated ; lateral areas well defined, with 3 subobsolete, radiating series of large granule.- : beaks scarcely apparent; umbonal margin slightly turned inward, and having dark spots giving a false appearance of teeth. Central areas having separated longitudinal series of narrow, subobsolete riblcts, furnished with large granules. End valves having similar radia'inir granulous riblets. Umbo of posterior valve scarcely cen- tral, little projecting. Interior: sutural plates separated by a large flat sinus; insertion plates subobtuse, the end valves having 1"-1_, central valves 1 slit; eaves moderate, subconspicuous. (Jirdle wide, closely clothed with imbricating, elongated, transvei>« 1\ striated scales. Length 73, breadth 41 mill.; divergence 1 (Cpr.} Catalina Islanf''ii,'n* anibr'icttxtuhi* Ci-i:., Hep. Brit. A.«so. Adv. 8 isi;:;, p. 649; IVoc.Cal. Acad. N. S. ii, p. -iVl.—Mm,,- iW- costatu* ( 'i'ii., J/& The sinus has a thin, smooth lamina separated by a slit on each side from the sutural lamime. It is a small, arched oraii-. with rows of prominent granules over a shagreened surface, ' l-i'llNn* HI!' >V N i ii N- < 'arpenter. I'n >/" /'"'. 11 small, whitish, tinned \vitli rOMafte; valv»- gi.thic-arched, mi suharute; entire surface minutely irranulnse: lateral -picii'Misly il. -lined, having strong diagonal and sutural ; with well projecting rounded grains; end valves hav- ini: -uhohsolete radiating riblet>: central areas having about s di.— taiit, raised subgranulose longitudinal rihs on each side, the rih< at the jugum : inter.-ticcs latticed with suhradiating rihlct-: umhnnes conspicuous, the uinhonal margin deeply toothed by a wart- bearing ril>. the teeth 8 to 10, obsolete toward the jugum : margin • ly intortrd. Tnibo of posterior valve submedian. slightly j >ro- •iiaririn elegantly pectinated. Interior: sinus large, Hat. : rate : insertion-plates acute, broadly uniiissate. end ••s having about 8 slits ; eaves conspicuous. Girdle having lar^- riated scales. Length 61, breadth 2-1 mill. ; divergence 90°. (Cj^r.} ,! /xA//td, 20-30 fins. veredentiens CPR., Rep. Brit. Asso. Adv. Sci. p. 'il!*: I 'roc. C'al. Acad. Sci. iii, p. 211. A small arched species, sculptured like /. mertensii, but with two 8, one of which dentates the sutures. The girdle scale- rat her large, flattened and striated, as in typical I&knochiton. I. BBRRATUB ( 'arjicnter. Utifiyured. Shell small, ashy, dotted here and there and especially at the suture- with olive, sometimes spotted with red ; oval, suhdepressed, the sutures indistinct; entire surface mo.-t minutely granulated: lat'-ral areas strongly defined, provided with two to five very wide, obtuse rihs, no interstices; posterior margins elegantly serrated. Central areas having about 12 acute parallel ribs on each ride; juLrum obtuse, scarcely uinhonate: with subradiating latticing ribs. intei>tiees impre.-sed. Mucro median, obtuse. End valves having about 20 obtuse rihs, like the lateral areas. Interior: median valves bifi>sate, end valves with about !> .-lit-. Sutural plates i liirdlc imbricated with large, scarcely >triated .-cales. Length 8'. breadth ~> mill. ; divergence 115°. (<>r-) Caj" >V. /. ' 'fiwritin. Ischnochtion terratut CP&.I Ann.iV Mair. Nat. Hist. (3) xiii. p. UN... in;. I. \i 1:1 OTINCT1 - < 'arpeiiler, n. |p, ( 'nj Shell resemblili (f, but the lateral AfMI Scarcely defined, radial and Ion-it udina! Kntire surface equally granulated. < )ran-e .-potted \vitli Interior: posterior valve having 11, central \alv<- I, anterior l.'J.-lits. Len-th «;.. breadth \ mill.; diver-ence IIHI . r//r.) ( ''ilnlinn, Ixluiitl, ( 'nl. Thl8 Species is known from Tr.jln.rti* by the valvis not beini: beaked, and by the large striated scales of the margin, which nilile tho>e of /. scabricottatut. (Cpr.) I. DECIPIENS Carpenter, n. sp. t'njnjured. Shell exactly like /. /irrfinii/'ifii*, hut reddish, rK-vatod, the JIILMIID acute ; scales of the girdle small, striated. Length 15, breadth 7-j mill.; divergence 105°. (Cj>r.') This very pu//lin,ir shell differs from /. *!nn(lriited punctate wrinkles, hardly lirate ; lateral areas strongly longitudinally corru- gated. Interior: posterior valve with 8-10, anterior valve i central valves 1 slit. Sinus wide, flat. Girdle thin, covered with very close, very small striatulate imbricating scales. Length 13:], breadth 7 mill.; divergence 90°-100°. ( 'otalina Is., beach to 40 fms. (Cooper, Cal. State Coll. No>. 1 • 1070,1074); Todos Santos Bay (Hemphill), California. Differs from Stenoplax samjuine.ii* in sculpture as well as in the plan of mantle-ornamentation. A specimen from Todo- Santo- Uay (under a stone between tides) collected by Henry Hemphill, is about the size of limactfornil* from Ma/atlan, and it would natur- ally be so called; the sculpture, however. i> >« -n-ibly ditfi-rent, both from that and from /'•. The central areas are minutely, the juir;d areas very minutely, wrinkle-punctate, wrinkle- an-jular. irregular; lateral areas moderately dcfineil and el and, llM ISCIIN'M HI TON. ther with the end valves, irregularly. suhconccntrically and >t ron-jlv c,.rni'_rat( <1. Mucm median, planate. This -pr<-i«- i- a ii/iij- in furin, but & true Itchnoehiton in its imbricated scales, which arc. bowever, extremely minute. This specimen is n-iruhirly arched. much less elevated than the type, with which, however, it agrees well in particulars. Length '_M, breadth !» mill. (( I am unable to see why this should not he considered a .sVr///y/A/./-, imles- it !>e on account of the smaller girdle scales; but, as I have not seen specimens, I deem it be.-t to leave the specie- when- ( 'ar- penter placed it. I. SUBCLATHRATUS Pilsbry. Shell suhrotund, depressed (at an angle of 130°); brown-olive; valve- very wide, the margins lobed, interstices nearly straight. Intermediate valves granulated at the dorsal ridge and more or [em all over, having two strongly tuberculate ribs, one diagonal, the other in front of the suture; lateral areas small, granulate; central areas having four longitudinal bars on each side, the bars tuher- culate, interstices granulated. Front valve having about eleven rounded, suhtuberculate radiating ribs. Girdle very wide, having close small scales ; valve-margins simple, the anterior having 9 slits. Length 41, breadth 3 alt. -5 mill. , under stones. Lepidopleunu rluthrnhi* CPR., Mazat. Cat., p. 1 05 (1857) , /W»//o- r/tifhr'ifnx (Vi:.. J/& — Not Cli. r/'itlirntu* Ri:i:vi:, Conch. Icon., pi. xviii, f. 113 (1847.) I have not seen this species, the name of which ha> been already used by Reeve. Carpenter write- as follow.- : One very small specimen was discovered on a stone to which a Crucibulum had been attached, beautifully perfect except in the loss of the anterior valve. A dead anterior valve was found of a much larger specimen displaying a marginal structure like that of /,. The shell is remarkable for the Mrong bars across the central area-, and the stout rows of tubercles which run, tin- •-nally. the other along the inteistitial margin. The mantle is v.-i-y hr..ad and crowded with minute Males. '/"*.) I have no opportunity of re-examining the type of this minute shel. bether the very minut n-e sti-iated. If so, it mii-l clotdy re-.Miihle the young of /. . The jiaucity of lr< ll\<" III i genuine Ttchnochitont in the Gulf fkuna i- n-mark:ih|'-. so many .-prcie.- ;nv found I'urtlirr north. < '///•. l/> Section Lrj,i'iln;nnn Pil-hrv. I 3 LepuJopfetmi* CARPENTER (Table of lirgular chiton- DM i.. Proc, r. B, Nat. MII-. 1878, p. 881, type / Mdd. \ ,| LtpidopleuriU of Ki--<>, Hi-t. Nat. Kiir. M«'-rid. iv, p. iX'Ji!, nor of II. iV. A.ADAMS, L 858, HOT of CARPENTER, Ma/at. Cat i Valves having sharp but somewhat, rugose and tliick in>ertii.n teeth, and Mypically) the sinus is delicately toothed within. (Jinllr covered with convex scales, usually snioot liisli. Type /. mer\> This section diflers from Ixcluxx-hitnn not only in havini: the gir- dle scales convex and smooth or hut slightly striated, hut al>o in the toothed sinus. It is, however, an artificial Lrrouj>, the species being more closely related to a number of diverse /.W///W//Vo//x than to each other. Numerous transitions from the smooth convex scales to tlat striated scales occur, the variation in degree of stria- tion being considerable in some species. This section in its present limits is therefore merely a temporary expedient for convenience in identifying species. It should rank as a section under Minorhif<>n s. s., rather than under Isehnoradeia, to which group these species have no especial affinity. The status of the name Lepidopfatnu has been discussed on page 2 of this volume. I. MI- UTKNSII Middendorff. PI. 26, figs. 20-26. Shell oval, elevated, with angular dorsal ridge, and straight -side- slopes. Varying in color from orange-red to claret-red, or even dark red-brown, and either unicolored or speckled and blotched with white. The lateral areas are elevated, and sculptured wiih radiating rows of elevated pUStuleft Standing upon a smooth, alm«»t tlat ground; the pustules of the SUtura! row often irregular. Central area- hav- ing acute, narrow, parallel rai-ed riblets, the intervals bet ween them regularly latticed across, except at the dorsal ridge, where the rihlcts have a tendency to diverge, and the CTOBS hatchi letfe End valves radially pustulo.-e. Mucro central, low, tlat and incon- spicuous. Interior white or blue-white, the median valves when det-ached showing broad red-brown ray.- po.-teriorly. the end valves with [81 ll\. H II1TON. :,»• same color. Sutnral plates low ; sinus flat, angular, tinely toutheol. Anterior valve having 10-11, central valves 1, po>teri»r valve 10 slits; teeth rather >hort ami obtuse, and u.Mially di>tinctly belted : eaves rather wide. Girdle tinn. compact lv cover. d with regular, solid, oval, >hinii>g scales, which are usually smooth, but frequently are superficially or telj striated ii-. 22, Length 85, breadth L'l mill. |.e,,LMh :'>*. breadth 2-°, mill. Sitk't iifinl/i to Mnnh-i'ci/, ('of !j'"r/i in. Chiton \ Mi DP., Hull. Acad. Sc. St. IV-tcrsh. vi. p. 118, lsl«i. — Chiton (PhcenocJiiton, Ilmnm-hiton, Stenosemus) merl Mi 1.1... Mai. Ro.-, p. :U, 125, t. 14, f. 1-3, 184?*— J*pfoeAiton mertentii II. £ A. AD., (Jen. Kec. Moll, i, p. -47-">. 1>">4. -J,rj,i'il>,- tM )m-rten*ii CPR., J/*S., and DALL, Proc. U. S. Nat. Mu-. 1 >7V. p. 8 This species may be known by the more or less red coloring, the shining convex oval scales of the girdle, which are usually alnn»t smooth, and by the strongly developed sculpture. Attention has alr«-a'l v been directed to the similarity of the Ch&topleura '/'""/"" «>f Cpr. i p. '•}} i, which dillers mainly in its spar.-ely hairy girdle. - iihrrn examples of this species are larger and more frequently variegated with white than those from the northern part of its range; and the girdle scales seem to be more distinctly striated. They seem to be almost or entirely smooth in mo>t northern speci- mens as far as my material shows; and I do not doubt, that Car- penter's figure (pi. 26, fig. 23) was drawn from a specimen collected north of San Franoisoo. In almost all of the specimens from the smth which I have examined, the scales show a delicate striation \\hen illuminated from the side, or at right angles to the direction of the stri;e. This is shown in figure 2U, drawn by the author from a Monterey specimen. The sculpture of the valves is peculiar ; the ! area ha- diver_'inir line, with smooth intervals. This is always most pronounced on the seconil valve (Hg. lM . the other valves often having the line more nearly parallel, and the intervals not all smooth. This is shown in fi_r. 25, repir-entiii- a fourth valve; but in smm- specimen- the divergence is even le>s pro- iiMiincrd than in this. The pustules upon the front valve occas- ionally become soldered \> Uto riblets, but those of the tail val mill disti: l-< H\M. IN | I. . OOPEBJ ( larpenter, n. >p. I'l. •_'»;, figg. -j; shell oval an.l elevated, wiili angular dona! i side-slopes, Sculpture like Lmerientii. ( 'oh.r <,li\ae« ,,n.~, or dull earthy In-own, indistinctly clouded IM..IV or ten \\iili liirht blue, especially upon the side areas. The lateral areas arc iai-f rounded pustules, the young bavin- four : the adull (I to 's. A >troiig lens reveals a line, suhol»ob-te irranula- tion of the nearly Hat surface between the pustules. The central areas have a line hut distinct and even radial striation, over whieh run acute narrow raised threads parallel to the dur.-al rid-c; upon the ridge these threads are seen to be more or le.-s divei-ifim:, specially ii])on the second valve. The end valves are radially ridged, the ridges bearing elongated pustules, or showing - where such pustules have been. Mucro low, flat. Interior bluish, the valves marked under their innbnnes with dark olive. Head valve having 11, central valves 1, tail valve 11 >lits ; teeth roughened but rather sharp; eaves wide, dark, minutely punctulate, but solid, not spongy. ( iirdle compactly covered with small imbricating, deeply striated scales (fig. 28). Length 40, breadth 24 mill. Xmt.tti ('rn: and Bolinas, California. This species closely resembles 7. mertei>*ii in shape and sculpture, but it differs entirely in the smaller, distinctly striated or grooved scales, in the sombre coloring both outside and within, in the closer pectination of the inter-liral spaces of the central areas, and in the more developed microscopic granulation of the lateral areas. It cannot be claimed that all or any one of these characters is invari- able, but the balance of them taken together, seem to indicate that differentiation has proceeded to a stage we may call specific. The following species is allied to this in coloring, but differs sufficiently in sculpture, a< well as in the girdle-seal'-. The details of sculpture and the scales of all three >p drawn to the same scale. The third valve of/, cooperi is >h..\vn in tb-s. I'D, :](). It must be remembered that the valves behind this, and usually even the third, have less markedly divergent -culpture than the typical form here shown. The specimens herein described and figured are from Bolinas, north of San IVanci-co, and since no diagnosis has been published hitherto, thc.-c will be considered the typical specimen-. Carpel specimens were1 from Sta. Crux. 1-JS [8GHNOGHITOK, I 8INUDENTATU8 ( 'arpcnter, n. sp. Unfiyured. Shell oval, much elevated, reddish : juLTum acute-; nuicro median, Iv elevated: entire surface minutely irranulose. Central - lia\ mi: about 12 Bubparallel bare, Which pectinate the i'n.nt marLriu. their iutn u--ated : lateral areas havini: '5-4 irran- OSC radiatini: lira-, the anterior valve With 26, posterior valve 24 such Lim. Interior: anterior valve with 10, central 1 , posterior valve l) slits; teeth acute; eaves conspicuous. stibspongy, crenulated by the sculpture ; sinus wide, short, laminate with ahout «; teeth. Girdle having moderate si/ed, wide, conspicuously striated, rather iarly imhrioatiDg scales. Length 15, width !•• mill. ; diver- gence 100°. (fyr.) Monterey, Cti/ii'u-uin. This shell has the color of /. mertensii, nciirl/ the sculpture <•!' /. f.cctumi.itn* and the normal scales of this «rroup. Like /. /•"/"- . it htis the denticulate sinus of Chiton. (Cpr.) I. CLATHRATUS Reeve. PI. 26, figs. 31-'U. Shell oval or oldong, elevated, the l>ack carinated : >ide slopes i\\\ : lateral areas and end valves radially grauulate-lirate, cen- tral areas latticed. Color dingy yellow, clouded with black, or rarely unicolored yellow or olivaceous. The lateral areas are raised and sculptured with about 5 rudia- atin_r. clos-ly and conspicuously irranose rihlets. the posterior rib wide or hilid : stroiiirly [icetinated alon<_r the sutuial (d^e. Central area- havini: longitudinal narrow bars parallel to the doi>al i d l»y liars of almost e<|iial prominence vertical to them, prodiieini: the effect of a grating. Mucro depn-s-ed. fnterior whitish, with olive or leaden ra\s under the uinboiie-. Sinus flat, denticulate; anterior valve having 11 -I'-', central valves I, posterior Valve 14-HJ >lits; teeth rather sharp, but not thin id; Girdle Compactly covered with very convex scales, which aie ob-oletely striated. ,jtli 27, br.-adth 17 mill. Length 84, breadth is mill. and Son to I.> Pout, / i-i IIN«H mi' 1'lu'ton rfittlu-'itu* III I A i . < '..nrli. Iron., I. 18, f, US, A pi — Le}>il>/''iinr f'/iilni, /,<'<•/!, iatn.< Sou i RBY, altOai (7; //OH (jmt., j>. I'.l ).— Li'indnjtlcnriiA i,,'ctiinilutu.<< < Yl:. .!/>'. and of Ainrriran collectors and writers. Carpenter's diagnosis in Proc. Cal. Acad. Sri. -eems to have included both this species and /. roopo-l, but he afterward distin- guished tlirni upon receipt of better material, and re-Darned the prev- ent form " pectin tilatnu."' This species seems to replace /. mertensii south of Monterey. It is a dingy, lusterless shell, resembling mertensii in the shape of tli<- girdle scales, which are, however, not so bright and clean in the dalhrtitns. It has decided riblets on the lateral areas, and the lattice-work of the central areas is strong and much less finely cut than in cooperi or mertensii. From /. cooperi, the different scaling of the girdle, as well as the sculpture of the valves, separate thi- form. The second valve has divergent sculpture on the dorsal ridge, but upon the other valves the riblets are parallel or nearly so there, and the interstices are latticed. I. COREANICUS A.dams & Reeve. PI. 27, fig. 50, (enlarged.) Shell ovate, rather elevated, terminal valves and lateral areas of the rest radiately grooved, interstices convex, peculiarly grained, grains prominent, round, solitary ; posterior terminal valve um- bonated, extremity radiate, small, short ; central areas longitudinally very finely granosely ridged, interstices between the ridges hollowrd ; lateral areas blackish-green, grains yellowish, central areas yellow- ish blotched and variegated with black ; ligament finely granosely coriaceous, tessellated dark and pale green. The sculpture of this species is not much unlike that of C. lurtdus ; still it is distinct, and accompanied with a very characteristic of painting. The central areas of the shell are of a yellowish ground, blotched and variegated with black. The terminal and lateral areas are very dark green, with the prominent granules con- spicuously tinged here and there with yellow. The ligament is strikingly tessellated with dark and pale sea-green. (/. Korean Archijtehtgo, under stones (Belr: 9 130 I8CHN<>< IUTON. coreanicus Ri:i:\ i. I'. X. S. 1847, p. 24; Conch. Icon., t. 26, f. 128.— AI.AM- iV Kvi :.. Voy, 'Samarang' Zool., Moll., t. 15, f. 9. — S< HIM N< K. llek u. I-'oi-M-l). ini Amur-Lande, ii, p. 281, f. 1-0. — Lophyrus c<> DKK., Ind. Moll. Mar. Jap., p. 1 ~>7. Carpenter (MS.) compares this to /. pcctinulatus and 7. co«y Schrenck reports it from the Bay of Hakodadi, on the- authority of Lindholm. I. JMI.CHKKRIMUS Sowerby. PI. 27, figs. 47, 48. Shell oval, elevated; jugum acute; mucro conspicuous, elevated, median. tlie slope behind it concave. Color red, variously clouded or streaked with ashy. Jugal area hardly defined, smooth at the prominent beaks ; central areas having 16 to 18 acute, subparallel lir;«' on each side, meeting over the jugum but otherwise nearly parallel ; interstices crenulated ; entire surface granulated. The interstices are decussated by the buttresses, as it were, of the cren- ulated sides. Lateral areas with 3 principal rows of close knobs, inrreasing to 5 rows by intercalation. End valves having 16 to 20 such rows, the interstices crenulated. Sutures with sharp rows of granules in addition to the contiguous ribs. Interior: anterior valve with 7, central 1, posterior valve 10 slits; teeth obtuse, striated, slightly pectinated ; eaves small ; sinus deep, flat, dentic- ulate. Girdle tessellated, imbricated with large, solid, more or less striated rounded scales. Divergence 97°-107.° (Q>r.) Length 24, breadth 13 mill. Island of Bo hoi, 7 Vi ///;>;// Chiton j>nlc.herrimus SOWB., P. Z. S. 1841, p. 103. — Rr.i Conch. Icon., t. 20, f. 132. This species, says Carpenter, is very close to /. merte»*ii. The striation of the scales is conspicuous in some specimens, on others scarcely seen, yet they all appear conspecific. The species is exactly intermediate between the two genera, Chiton and Ischnochiton, the teeth being scarcely pectinate enough for Chiton, and yet it has the balance of its characters. One specimen has very little light, clouded with dark; one almost entirely light, with one dark streak on both sides of the central areas; other specimens are inter- mediate. ( Cpr.) I. CRATICULATUS Gould. Unfigured. Mucro central, scarcely elevated; central areas having 18-22 bars; on the acute, much elevated jugum scarcely obsolete; ISCIIN'M || I IMS. interstice.- traDSVenely wrinkled. Lateral areas havini: d< elevated Lrraniferotis rihlets, 1 in ymni.Lr, * I" H> in adult individ anterior valve having about ~ti} .-uch riblet-. Int. i '-rior valve bavin-: I 1 , central valves 1, anterior valve 1 0 slits ; teeth short, not very acute, outside and at tin- margins in (rout rugulose, almost pectinated in front. Kav«> -mall, obi < |Q| short, narrow, slightly denticulate. ( lirdle irregularly, closely imbricated •with small, smooth, solid scales. Length 1T>, breadth 1 -~> mill.; divergence 93°. (Cpr.) China Nn/x, orJii/xni (Stimpson, N. P. E. E. ; 1 specimen in Mus. Smithsonian.) Chiton (Le]ttochito)i) craticiilatus GOULD, Proc. Bost. Soc. K. II. vii, p. 101, Dec. 1859; Otia Conch., p. 117. — Lepidopleurus cratic- it tut u* (1I'R., MS. Dr. Gould appears from his diagnosis to have had several species under his eye when he wrote the description of this species. From his calling it a Leptockiton, he might have looked at the minute, chaffy scales of Trachydermon asperior ; when he wrote of long striated scales, he was probably observing Ischnochiton bixculptus. Again when he noted the great variation of the ridges (from 4 to 8), he probably had under his eye both /. cultratus and the species above described. Of the four, the balance of characters inclines me to retain the name for the shell last mentioned, although only one - imen was returned of it, mixed with the other three. Outside, the species is recognized by the solid smooth scales, and details of sculpture; inside by the blunt, somewhat rugulose teeth, which < in part of the anterior valve) are almost pectinate. (Q;r.) I. CULTRATUS Carpenter, n. sp. Unfigured. Shell similar to " L. craticulatus " ; mucro central, planate, but central areas having about 14 to 20 very acute, strongly developed subparallel lira?, becoming less acute, somewhat obsolete, on the dorsal ridge ; sutures elegantly pectinated, interstices cancellated with small wrinkles; lateral areas having 4 low, gninifurous liruhe, and a fifth line of granules at the sutures, the grains sparse, small, but strongly projecting. Posterior valve having about 18 similar liruhe, anterior valve 24. Interior: posterior valve having i), central valves 1, anterior valve 8 slits; teeth acute : eaves projecting : sinu> small, deep, sensibly laminated, smooth. (lirdlo regularly imbri- cated with flat, smooth scales. (Cpr.) .Length 27, breadth 17 mill. 132 racHHOOHirov. If'ilcud'idi. Jit/Kin > Stimpson, X. P. E. E. Smithsonian Mu-.. 1672.) Chiton pult'herrimus (pars) GI.I>., J/\, not Sowr,. — Leptorhiton •nlatus G i.i>., //\ ( )iia, p. 117. (Cpr.) This species differs from /. pulcherrimus So werby in having five rows of extremely fine, distant, but strongly expressed granules, instead of three (rarely four) of very coarse ones. This lias the space between the very sharp, knife-like central ridges but faintly cancellated with rugose lines; while in pulcherrimus the cancella- tion is so strong as to make the ridges appear granular. But the principal distinction is that pulcherrimus has strong striie on the mantle-scales, while those of cultratus are smooth and larger in proportion. It has the same general aspect as /. craticul'.. p. 88. Carpenter seems to have decided that the /,. mnrandrei of his Ma/atlan Catalogue was identical with Hoove's C. w/.-'m /•/'//.•*, although he remarks that he would not have known it from the E8OHKOCHIT< and description u'ivrii l»y Reeve. I. PUBIO Sowerhy. Shell oval, smooth ; olivaceous, ornamented with nimu-roiiggreen dots; front and .-ide margins of the valves rugulose. Marginal ligament scaly. Length 12*, breadth 7' mill. (Sowb.) , Valparaiso, on Amphidrsma Bolldum, 30-50 fin*. ; sand bottom. Chiton /mtio S<>\\ KKI;Y, I*. /. S. 1832, p. 105. I. DALMI Haddon. PL 25, fig. 1-10. Shell evenly covered with closely set minute low tubercles, wliieh give it a granular appearance; with straight-sides meeting at an an^le of 110°. Anterior valve closely granular, with twenty-six short radial rows of tubercles, each row consisting of four or five tubercles, which diminish in size from the periphery towards the apex ; the posterior row is the broadest, and is partially bifid. Intermediate valves. Central area: jugum coarsely granular; pleura with about 12 or 13 distinct horizontal ridges; lateral areas granular, with three main radiating rows of tubercles, the anterior and posterior often partially double. Posterior valve remarkably fiat, coarsely granular, with nineteen rows of three tubercles each, of which the outermost is the largest ; umbo scarcely, if at all, raised above thje surface; anterior border coarsely granular, with the granules passing into oblique ridges on the pleura. Girdle medium breadth, upper surface with smooth imbricating scales in oblique rows, about seven or eight in a row, those nearest the shell being the smallest. Color greyish -white. Length 11, breadth 6, height about 3 mill. Gills extending to about three-quarters the length of the foot, diverging posteriorly and hidden by a slight swelling of the longitu- dinal band on the under surface of the girdle ; about twenty-one in number, largest about the fifth from the posterior end, and gradually diminishing in size anteriorly. (Haddon.) Lat. 51° 27' 30" S, long. 74° 3' W., 400 fins, blue mud. Lepidopleunu dallii HADDOX, Challenger Polyplac., p. I1', t. 1, f. (>, t. :), f. 6a-6i. I have associated this species with the name of my friend Mr. \V. II. Dall, of the Smithsonian Institution, Washington, ( - A (Haddon.) 134 I-< IIN«i HITON. I. MCI i.osrs Carpenter, n. sp. Unfigured. '•11 oval, little elevated, the jugum acute; mucro slightly elevated ; brown-olive, elegantly dotted and clouded with darker, and sometimes maculated with ashy or roseate. Central areas gran- ulated in a somewhat quincuncial manner, rather regular lines radiating from the jugum. Lateral areas scarcely elevated, having 3 to 5 scarcely projecting radiating wrinkles; end valves having 30 to 40 subobsolete radiating wrinkles, and granulated like the central areas. Interior: posterior valve having 11, central valves 1, ante- rior valve 11 slits; teeth acute; eaves large; sinus moderate, flat, smooth. Girdle variegated, regularly covered with solid, large, sub- rotund smooth scales. Length 15, breadth 10 mill. ; divergence 110°. (Qor.) St. Vincent, Cape Verde Is* Curiously like /. comptus in color and sculpture, but that species has the scales extremely finely striated, the side areas a little more decided, the granulation less regular, the painting more sombre and the sutures tessellated. These minute differences, joined with the wide separation in locality, probably denote a different origin. (Cpr.) The type is no. 88 of the Cumingian collection. I. OHTUSUS Carpenter, n. sp. Unfigured. Shell small, strongly elevated, oval, the jugum little acute; mucro median, conspicuous. Reddish-brown, variously maculated with paler. Central areas having about 10 subparallel deep sulci on each side, obsolete upon the jugum ; lateral areas with 3 to 4 radiating wrinkles, sometimes divaricating, the end valves having 20 to 40, here and there interrupted by wrinkles of growth. Interior: pos- terior valve having 8, central valves 1, anterior valve 9 slits; slits small, teeth very short and obtuse, sometimes rugulose or almost pectinated ; calloused inside ; eaves small ; sinus moderate, exrurvnl, smooth. Girdle furnished with very close, small, very solid, rounded, smooth scales. Length 12$, width 7' mill.; divergence 85°. (Cpr.) Portugal (Mus. Cum., no. 105.) A remarkable shell, presenting some general resemblance to mertensii in the appearance <>f the valves. The girdle scales are as small as in Trachydermon, hut very solid. The specimen is much worn outside, which may account for the bluntness and callosity .if the teeth, (f/ [ft HHO mi I. i i M i S)\\rrl»y. 11. 27, l'iLr. I t. Shell oval, cariualed, smooth : hack elevated ; lateral area- i, spicnoiis. ( 'oh»r lawny hrown, ornamented with rounded hlue Spots. Mar-in minutely scaly. Length 1 .">, hrradth !> mill. (Sowb.) "Newcastle, AvttraUa? C. lentiginosus Sown., The Magazine of Natural History, con- ducted by Ed w. Charlesworth, iv, new series, p. 293, .June. 1840; Conch. Illustr., f. 120. Chiton cyaneopundatus KRAUSS, Die Siidafric. Moll., p. 40. Kxcept in heing somewhat larger, and said to be from a different locality, this seems to be absolutely the same as /. cyaneopnndatut Krauss. It is likely that the Australian habitat assigned to lenti- guiosus is a mistake. The description of cyaneopunctatus here follows : C. cyaneopunctatus Krauss. (PL 27, figs. 40-43). Shell si.iall, oblong-ovate, thin, semi-pellucid, convex, carinated, shining, a.-hy, orange or brown, closely painted with dots and lines of blue ; very minutely punctulate; intermediate valves narrow, subrectangular ; lateral areas slightly distinct ; end valves delicately concentrically striolate. Girdle ashy and rufous banded, scaly, the scales distinct, subrotund, polished, shining. Length 10*, breadth 6 mill, (jfifr.) Cape of Good Hope. The valves appear smooth to the naked eye, but under the lens delicate, elevated points are visible upon the central areas ; and on the slightly raised lateral areas and the end valves, there are very delicate concentric striaB. The head valve has 12, the posterior valve 13 slits. The median valves are very narrow (5'2 mill, wide, 1-2 long), with one slit in the insertion-plates. The scales of the girdle are as large as those of C. capensis Gray, shining, convex and rounded. The color is very various : gray, blue-gray, yellowish and reddish-yellow to brown shells occurring, but all show under a lens sky-blue dots, which frequently coalesce into lines. Tho girdle has darker transverse bands. (Krauss.} I. DORSUOSUS Haddon. PI. 25, figs. 11-19. Shell remarkably compressed laterally, the two sides meeting at an angle of 75°. Anterior valve concentrically ruirose, with about 26 radiating low irregular ridges, some of which hifuivate. < Vntral areas, with jugum and anterior border striated, the pleura will tinct horizontal ridges. Lateral areas distinct, concentrically rugose, 136 i-« IIN<>< •HITON*. usually with three main radiating low ridges, the anterior and pos- r of which are often bifid. Posterior valve concentrically rugose, with fifteen irregularly arranged low radiating ridges. The anterior ridge is broader than the others, and may be slightly bifid, umbo rudimentary; anterior border smooth, with slight concentric lines of growth. Lamina- of insertion moderate in size. Girdle narrow. Upper surface with ovoid, slightly overlapping, somewhat granular scales; edge with minute projecting spicules; under surface, with long, narrow, closely applied scales. Color white. Length 21'5, breadth 7'f>, height 6 mill. (Haddon.') Prince Edward's Island, Lat. 46° 41' S., long. 38° 10' W. 310 fros. Lepidopleurut dorsuosus HADDON, Challenger Polyplac., p. 1 1 , f. 5 ; t. 3, f. 5o-5t. 1886. Gills extending to more than half the length of the foot, twenty in number, the middle somewhat larger than the remainder. The name dorsuosus, full of ridges, is applicable to this species on account of its numerous longitudinal and radiating ridges, and at the same time recalling the steep ridge of the shell itself. (Haddon.) I . \hii\ IDENSIS Reeve. PL 24, figs. 7, 8 (enlarged.) Shell somewhat shortly ovate, very minutely reticulated through- out, under the lens; terminal valves and lateral areas of the rest finely ridged, ridges waved, central areas smooth, lateral areas not raised ; livid olive and yellow, flamed with brown in the middle, posterior edges of the valves articulated with brown ; ligament Lrnmately coriaceous, grains very large. (7?ve.) I '<>rt Adelaide (Rve.) ; Port Molle, Queensland (Coppinger), Aus- tralia. Chiton adelaidensis REEVE, Conch. Icon., 1. 19, f. 123. — C. (Isch- 'itonf) adelaidensis E. A. SMITH, Zool. II. M. S. 'Alert/ p. 79, 1884. — Lepidopleurus adelaidensis CPR., MS. Smith L'ives the followini: notes on the specimens collected at Port Molle by Coppinger: The entire surface of this species is minutely i:ranosely reticulated. the front valve, the lateral areas of the narrow central valves, and the hinder area of thepo.-terior are in addition somewhat irregularly radiately sulcate. The prevailing color is pale greenish, streaked and dotted with ivd, the posterior mar-in of the valves brinLT paler BtHO HI i < than the general tone of tin >hell, ami con-picuou-i;, \\itli the same red color. The -ruins ..f the mantle an- .-m«n.tli. arranged in alternate grrrnisli and reddish patches, and individually have a ide areas di-tinct, slightly raised, more variegated and darker than the central areas. ,Ji: 138 I8CHNOrmi< sharp ; nmer<> not much raised, situated at the front fourth, posterior slope a little concave. Valves square, not beaked : Lrlo~\ -. \\ith very- fine quineuneial granulation. Inside : posterior valves having 10 or 11, central valves 1, anterior valves 11 slits; teeth sharp, thin, and rather Ion- : >inus broad, deep, flat, not channelled at the sides ; eaves projecting, granulated in quincunx but not spongy. Girdle with rather large, stout, smooth roundish scales. (Cpr., from types). Length 13 J, breadth 8 mill.; divergence iL'n . Port Jackson, New South Wale*t Austral in. Lophyru* *innrms AN<;AS, P. Z. S. 1867, p. 115, t, 13, f. 28; t. '•.. p. '2"2'2. — Lepidoplenrus smaragdinus CPR., MS. I. SULCATUS Quoy & Gaimard. PI. 38, figs. 24, 25, 26. Shell oval-oblong, quite convex, obtusely triangular, with narrow girdle ornamented with little, rounded scales, each of which is green. ish with a brown dot. The valves are wide, arcuate, almost without carina, very prettily grooved lengthwise on the sides, and zigzag in the middle. The lateral areas are triangular, granulose, and elevated. The anterior valve is simply granulated, with 11 or 12 teeth; the posterior valve is larger with 13 teeth, and above it is striated in front, and with marginal granulations. The sutural- plates are short and separated. All of these parts are of a hand- some clear green varied with white. The base of each of the lateral triangles is white. Each valve has at the summit a green spot surrounded with whitish, or sometimes with rose, in which case the interior also is roseate. Length 30, width 18 mill. Port of Kiny Geor now included herein, whilst his diagnosis covers all Radsioid forms of Iscknochiton. I have therefore restricted the namelschno- r>i'l*ia to the forms grouping around Shuttleworth's first species, auttralis. I. TKIDKNTATUS Pilsbry, n. sp. PL 18, figs. 35, 36, 37, 38, 39. Shell small, oval, moderately arched, slate-color with white spots and dots, or white mottled with slate ; the girdle tessellated with alternate dark and light, the interior blue, with a leaden spot under each BUtural-plate, and short dark rays from the apex. The valves are evenly arched. The posterior valve (fig. 39) has a central, rather depressed umbo, the slope behind it concave. Lateral areas raised a trifle, but scarcely distinguishable; central areas evenly, closely and finely pitted in quincuncial pattern ; the lateral areas are a little more coarsely sculptured with close low diamond-shaped granules ; the granulation generally less regularly arranged on the end valves than on the lateral areas. Interior with low, arched sutural-plates and wide, flat, angular sinus; anterior valve with 13, posterior 12, central valves 2 slits. Teeth sharp, smooth. Eaves very narrow. Girdle covered with imbricating striated scales (fig. 36.) Length 15, breadth 10 mill. l.aTnz, Lower California (Lockington) ; Gulf of California (Gab!..; / • M ,/•'/ni<';ith tin- h< ad, a- i: Stenoradria, The irills extend from tlic front end of tl within somewhat less than tin- width of a valv from tin- t.iil • -, I. vii:ii.ri.r> Couthouy. 1M. 17 Shell small, ohloiiLr, rather elevated and dc«-id»-dlv «;irinated; creamy yellow, or "of a very pale olive or drab color." Surface smooth to tlio naked eye, but under a lens it is seen to be every- where covered with low granules quincuncially arranged, lateral areas are a trifle raised, but not distinctly so, and upon them the granulation is somewhat effaced, and a few very obsolete radiat- ing sulci are generally distinguishable, as well as several rather strongly indicated growth-periods. "Interior: posterior valve hav- ing 13-14, (rarely 17), anterior valve 14-16, central valve?- slits. Teeth acute, distant; eaves acute, projecting, hardly spot sinus wide, short, flat. Girdle covered with rather large, wide scales, deeply and distantly striated." Length 13, breadth 7 mill. Orange Harbor, Terra del Fuego. Ch. viriduhis COUTH. MS., GOULD, Proc. Bost. Soc, N. H. ii, p. 144, 1846; Otia Conch., p. 5 ; U. S. Expl. Exped., Moll., p. 318; atlas, f. 413. — Ischnoradsia viridulas CPU., MS. — Lepidopleurus viri- dulus KOCHEBR., Miss. Cape Horn, Polyplacophores, p. 140. — 'f Minochiton viriduhis Gld., HADDON, Challenger Rep., p. 16,1886. A small form, evenly granulated, and having indistinct lateral areas. I have taken the description of the internal parts from Carpenter's MS., as I have not examined the interior of the single specimen before me, which is one of the original lot. I. TRIFIDUS Carpenter. PI. 18, fig. 40. Shell rather large, rather elevated, regularly oval ; red-ehotnut. maculated with lighter and darker; jugum acute, gothic. Mucro median, flat; entire surface very minutely granulated ; central areas having about 8 strongly punctate lines perpendicular to the jugum ; lateral areas strongly defined, having 2 to 4 obsolete ribs, sonutim.- punctate in the interstices. Interior whitish flesh-colored, with two reddish-purple rays diverg- ing from the flat umbones ; posterior valve havin_r !•'>, anterior central valves 2 slits; teeth acute, sometimes serrated at the edge, sometimes striated outside, sometimes smooth. Kaves subspongy ; sinus small, laminate, the lamina slit at the sides and sometimes in 14'J ISCIIN.X mi'.N IIAI.HI.I.I.A. the middle. <;irdlc having very small, solid, >mooth scales. Gills almost ambient. ( < 'pr.) Lenirth 40, breadth i>ii mill.: divergence 135°. Sitka to Pug^t Sound, 9-18 fms. Tr.H'hwI.nnn,, tni',,ln.« OR., Suppl. Kep. B. A. 1863, p. l>4'.» ; Proc. Acad. Nat. Sci. Phila. 1865, p. 60. — Ischnoradsia trifida CPR., .!/>.. and PXI.I., I'roc. U. S. Nat. Mus. 1878, p. 881. I have not seen this species. The figure is from a rude sketch in Carpenter's MS. Dr. Dall writes of it as follows: This rare and fine species is not particularly handsome, being of dull and livid colors, but is peculiarly characterized by the straight transverse ribs on the dorsal areas with spongy interspaces, and by the pretty regular division of the lateral areas into three well marked radiating costa?, which are separated in the insertion plate by two fissures. No other species of the region resembles this in srulptuiv. Mu/x.le with a pectinated margin in front produced into rounded lappets at the corners. Gill rows as long as the foot, con- taining each 28-35 branchiae. Veil absent. Mantle edge plain, narrow. There is a small spherical lump on each side of the girdle just behind the posterior ends of the gill-rows, which are turned out toward the girdle and widely separated behind. The anus is large median, and crenate, opening on the upper part of the hinder end of the foot. No ovarian openings could be detected, and the species presents some peculiarities which call for further research with more material. (Dall.) 1. KKCJULARIS Carpenter. PL 18, figs. 41-46. Shell oblong, elevated, dorsally carinated, the side slopes straight. Surface appearing almost smooth to the naked eye. Color a uni- form olive or slaty-blue, the girdle having more or less of a blue or purple " bloom." The lateral areas are very little raised, and are sculptured with numerous delicate radiating threads, occasionally branching toward the lower margin, and freely branching along the posterior edge of the valve. The terminal valves have similar delicate radii. The central areas have numerous longitudinal, somewhat beaded threads, separated by flat intervals. The posterior valve is elevated, with anterior uml»o. The interior is light blue. Sutural plates low, connected across the HMIIS by a narrow plate which is silicate above and cut into in i"N i: \ Den 1 1 \. ;ihi>ut 10 trrth liy delirat" .-lit-. Anterinr v:il\«- : • Tin nil '2 •"., poMrrior •_'•_' -lit.-. Terth even MIL! -harp, -li. -triatrd or grooved outside. Kav.- solid, (lirdle uid« , • eivd with solid, regularly and closely imlmeat iiiLr -triuted Scales 16), Len-th 85, lueadth, 1H mill. Monterey, ( c/iifnn regulari* CPB^ P. /. B, 1855, p. 'i'.vi.--l.--'>.l,<.,,,(bia r I- y n/> m'.* CPB., J/N. This species is of a very regular form, and a uniform dral>, -dive or blue color. It is not closely allied to any other West Coast form. Tlui number of slits in the posterior valve is unusually large. I. TIGRINUS Krauss. PI. 19, figs. 60-63. Shell oblong, convex, roundly arched, buff-white, unicolored, or striped lengthwise with reddish ; rarely roseate. Valves without apices. The lateral areas do not extend to the middle of the back; they are raised, and cut into radiating riblets by 8 or 10 narrow impressed grooves, and there are rather con- spicuous concentric wrinkles or waves of growth on the lower part of the areas. The end valves are similarly sculptured. Central areas closely and regularly pitted all over. Posterior valve rather large and depressed, with subcentral urn bo. Interior white and light brown. Anterior valve having 17-18, central valves 2-3, posterior valve 12-13 slits; teeth rather thin, but somewhat bevelled and roughened inside; eaves solid. Sinus wide and flat, the sutural-plates being rounded. Muscle-scars dis- tinctly impressed. Girdle rather wide, firm, densely clothed with somewhat coir finely striated scales (fig. 63). Length 22-28 mill. Cape of Good Hope. Chiton tiyrinus KRAU&S, Die Siidafric. Moll., p. 38, ? Ischnoradsia subcariosa CPR., MS. This species is readily known by its Radsioid valvi- and tln> beautiful web-like sculpture of the central areas, produced by the pattern of regularly arranged rhombic pits. It is like no other species, although the young of /. magdaleneiisis bears a slight resemblance in the sculpturing of the central areas. Although technically a Radxiella or Stenor' is not easy to decide which) this species probably was developed from a different stock of Ischnochitons. Indeed, the multiplication of side-slits may 1 1 I [SCHNOCHTTON-IBCHNORADeiA, ,i'ccted to occur in any branch of Chitons; from the genus IschnochUon alone, we have at least tour or five independent Kad-ioid branches. The typical /. tiyrinm* of Krauss is >triped longitudinally. The unstripnl form, of which several specimens are before me, may be called var. nnicolor. The species mentioned by Carpenter as /. subcariosa may be a form of /. tiijruina. The type is a single specimen of unknown origin, and is in the museum of McGill College, Montreal. Subgenus VII. ISCHNORADSIA Shuttleworth, 1853. Ischnoradsia SHUTTLW., Berner Mittheil. 1853, p. 65, species cited C. australix and C. magdalenensis. Not Ischnoradsia CPR. — Lepido- radsia CARPENTER, MS.; and DALL, Proc. U. 8. Nat. Mus. 1 p. 33 1 , type C. australis. Valves having sharp but rather thick insertion plates, those of the median valves with two or several slits. Girdle covered with convex, pebble-like, smooth scales. Type Chiton australi* Sowb. The typical forms of this section are from the Australian seas, but several species have also been found in Japanese waters. Carpenter's substitution of the name ' Lepidoradsia ' in place of Ischnoradsia, was in direct violation of the rules of nomenclature. Key to species. a. Sinus dentate within, albrerhti. ad. Sinus smooth. b. Central areas longitudinally ribbed, australi*,lHt/ubrw. bb. Central areas minutely granulated. c. Outside green, inside green and pink ; scales very convex, novcehol/andke. cc. No green or pink ; scales small, convex, lutkodadensis. I. AUSTRALIS Sowerby. PL 18, figs. 57, 58, 59. Shell oval-oblong, moderately elevated, the dorsal ridge sub- angular, side-slopes nearly straight. Color dark olive-brown, the apices of the valves pink when eroded. Lateral areas somewhat raised and sculptured with close, unevt n riblets, which usually bifurcate or branch freely, especially toward the posterior maririn of the area. Crntrdl ureas closely and eienly rSCHNCX HITOB fSCHlfOB LDtt \. ?/•//// y/'/irr /nni/ifinlinu/ r/A/r/x, ;>}>-<. Ictc »n t! win -iv they _irivc place to a d»-n.-r microscopic Lrran illation. apices of the valvc^ arc pink in mature >he!U. Knd valves sculpt- ured with clo>r radiating ril.lets, those of the posterior valve irreg- ularly ^ranose; IIUHTO rather depres.-ed ; posterior slopes of th- valve depressed and concave. Interior liirht blue-green, with two wide pink rays in each v and behind them two olive-brown rays. Sntural plates nun whitish or yellowish; sinus wide, flat, not in the least toothed. Insertion plates having 16-21 slits in the anterior, 2 or 3 in the median, and 17-21 in the posterior valve; teeth rather thick and stumpy, and a, little rugose, but sharp edged. Eaves wide and solid. Girdle (fig. 57) wide, closely covered with conspicuous, convex, pebble-like scales, which toward the outer edge are subcatinated in the middle. Length 62, breadth 35 mill. Port Jackson, Australia. Chiton australis SOWERBY, Mag. of Nat. Hist. (Charlesworth's), June, 1840, p. 290 ; Conch. Icon., f.46. — REEVE, Conch. Icon., t. 2, f. lO.—Lophyrus australis ANGAS, P. Z. S. 1867, p. 221.— Lepido- radsia australis CPR., MS. and DALL, Proc. U. S. Nat. Mus. 1878, p. 279, t. 2, f. 19 (dentition) ; p. 333 (branchia>).— HADDON, ' Challenger ' Rep., Polyplac., p. 1 9. — Chiton (Ischnoradsia) australis SHUTTLW., Bern. Mittheil., 1853, p. 66. — C. evanidus SOWERBY, Mag. Nat. Hist, iv, June, 1840, p. 291 ; Conch. Illustr., f. 139.— C. metallicus RVE., Conch. Icon., t. 17, f. 104, 1847. This species is distinguished from the following by the fine longitu- dinal ribbing of the central areas. The synonymy given above is unquestionable. Occasionally one or more of the teeth is cloven into a number of small ones ; the number of teeth varies considerable. Dall found the gill rows to extend the whole length of the foot, and to contain forty-seven branchiae in each. Mantle-edge plain, thin ; muzzle plain, semicircular, without a veil. I. NOV.EHOLLANDI.E (Gray) Reeve. PI. 19, figs. 67, 68, 69. Shell oval-oblong, elevated, the dorsal ridge an.Lrul:< opes nearly straight. Color green, minutely marbled with olive, the lateral areas darker. 10 14''. GBCHNO< in i' H iRADBIA, •••r;il areas somewhat raised, sculptured with low, uneven, some- what nod ulous radiating riblets, and some concentric growth-wrinkles. • ireas smooth o-f /o?* a very dense and reijnhtr microscopic fjrnniilnti-">, Dec., 1859; Otia Conch., p. 116. — Lepidoradiia lugubri* GUI.. < I'.:. The girdle, says Carpenter, is very like that of 7. p. 1M. in. ligs.fji. *'<~>t 66. Shell oval-tihloiig. moderately elevated, l>ack railn i mindly arched, \ cent rie wrinkles of growth ; central areas very mi nutcly pitted all over, the surface being something between aquinemirial granulation, and a succession of ww-like zigzags. End valves having fine radiat- ing riblets cut by some cencentric growth-sulci. Mucro in front of the middle, rather prominent. Interior blue-white ; sinus smooth ; sutural plates low, rounded ; anterior valve having 15-20, central valves 2-3, posterior valve 15 narrow slits ; teeth rather sharp, sometimes slightly roughened ; eaves short, narrow, solid. Girdle covered with small, solid, convex, smooth scales (fig. 66). Length 25, breadth 15 mill. Hakodadi, J This species, which was collected by Wm. Stimpson of the North Pacific Exploring Expedition, has very much the aspect of /. / co*us Old. of Australia, the sculpture of the central areas being of the same zigzag character. From all species of the /. longi- cymba group, however, this is distinguished by its smooth, convex girdle scales, and by the plurality of slits in the side insertion-plates. The above description and figures are drawn from part of the original specimens. I. ALBRECHTI Schrenck. PL 19, figs. 70-74. Shell large, oval, elevated, the dorsal ridge acute ; mucro median, nearly flat. Reddish maculated with darker, the interior having rays of reddish-brown. Entire surface minutely and closely punctate; central areas with about 30 lines of granules oil each side of, and parallel with, the jugum ; lateral areas having in the young 4 to 6, in the adult 10 to 12 radiating, distantly granose riblets; the end valves having 50 riblets. Interior: posterior valve having 12, central valves ? to 3, ante- rior valve about 17 slits ; teeth acute, sometimes rugose or lobed at the edges, outside ; sinn< moderate, 8 to 12 dentate. 148 OHirOKD Girdle pretty regularly covered with large narrow, -olid, smooth scales. ( ' Length 40, breadth 25 mill., divergence 112°. Hakodadi, Japan. Chiton albrechtii SCHRENCK, Bull. Acad. Imp. Sci. de St. Pelersb., v, p. 511 ; Reisen u. Forsch. im Amur-Lande, ii, Zool., p. 283, t. 13, t'. 7-17. — Chiton (Lepidopleurus) albrechti E. A. SMITH, Ann. & Mag. Nat. Hist., (4), xvi, p. 115, 1875. — Lepidoradsia granofilosus CPR., J/N. The form collected by H. C. St. John, R. N. at Endermo Harbor, Japan, is larger, (length 65, breadth of central valves 28 mill.), the lirations on the lateral areas are not granulated, and all the valves are distantly concentrically sulcated. Subfamily CHITONIN^E. Lophyroidea CpR.,-\-Acanthoidea lophyroidea and Acanthoidea typica CPR., table of Regular Chitons, 1873, and in Dall, Proc. U. at. Mus. 1881, p. 284 (1882).— Chitonidce and Acanthopleuridcs (part) DALL, Catal. Marine Moll. Southeast Coast, Bull. 37, U. S. Nat. Mus., p. 172 (1889.) Regular Chitons having the insertion-plates well-developed on all of the valves, and closely grooved or pectinated outside and at edge. The retention of Carpenter's groups Lophyroidea and Acanthoidea in anything like the limits given by their author, is simply impos- sible. On the other hand, a perfectly natural group is obtained by uniting these two groups, after excluding the "Acanthoidea isch- noidea" Cpr., and the group Craspedochiton Shutt., which have special characters not yet noticed in print. Within the group thus constituted, four genera having well- defined characters are distinguishable, all of them agreeing in the pectinated insertion-plates, though varying in the degree of pectina- tion. Synopsis of Genera. A. No eyes developed on the valves, a. Girdle scaly. Genus XII. CHITON Linn.'. Valves having one or several side-slits in each insert ion-plate, and a deticulated sinus separating the sutural plates ; girdle scaly, the ( III mi. 1.^1 ami s.»li.l, closely imliriral in-, rarely separated. Type ••n/ntiix Limn'. mt. ( iinllr willi , 06.— Sun i Bern. Mittheil. iv, p. 72. — CARPIOM 1:1: A- D.M.I.. IV . I'. S. Nat Mus. i, p. 300 (1878), type C. tnbercuhttus.— Not Chit,,,, II. ^ A. AD., Gen. Rec. Moll, i, p. 474 (1858.) Lophyru* (in part) POLI, Test. utr.Sicil. i, mnltn-ntri'i, p. 2, 4, etc. — H. A A. ADAMS, Gen. K«r. Moll, i, p. 46!> -in part.) 150 < HI TON. 'lopleurus (in part) Risso, Hist. Nat. Kur. M.'rid., p. 267. Oymnoplax GRAY, in The London Medical Repository, Monthly Journal and Review, xv, p. 234 (Jan .-June, 1*21.) Valves wholly external, the beak of the tail valve median or anterior; insertion-plates longer than the eaves, slit into teeth which are deeply and finely pectinated, and typically project outward on all the valves. Girdle covered with closely imbricating, convex, smooth or striated scales. Gills extending the entire length of the foot. Hi.\\ •ay. in his article "A Natural Arrangement of the Mollusca according to their internal Structure" (Med. Repos.), under the h«-ad of •' Or /V*///A/ro/;//o/v/," enumerates the synonyms of that term, defines the order, and otters the following arrangement: i'lates placed on the hack of the mantle. 1. < iymnoplax or jrymnoplacidae. Acanthochitona. Chiton facirularis. Ix'ptochitona. Chiton marginatus. /'. Plates sunken in the hack of manlle. 2. Cryptoplax. Chiton larv:eforinis." The inference from this would 1 e that Gray intended to include in " < ivmnoplax or irymnoplacida- " all Chit ms having exposed • Illl I .") 1 val\-e>. a meaning also favored by the etymology ; but in I'. / \^\^ he places (iiiiiiiinfi/ii.!- under <"/,//,, a synonym. In anv ca>e, tin- name (//////;/»•///'/./• cannot I" Vsed except in the uvneral way <|iioted above, and no-pecics lias ever hecn rxpivss ly deH-naled a< hrlnn^Ji,^ to it. The name has been ii>«'il by . a. Central areas having longitudinal riblets. b. Sides and ridge of central areas both sculptured. > < m r<>.\. c. Urabo of tail valve distinctly in front of the middle. d. Ril>let> of lateral areas rather smooth and fine. e. Dotted or spotted with Mm-. /. Large, black, dote Bmall, ff. Small: dots large, ee. Concentrically Hneated with brown or dark, cumhufi. eee. Unicolored or blotched. /. 17 slits in head and tail valves together, perviridis. ff. 22-24 slits in head and tail valves together, quoyi. fff. 35 slits in head and tail valves together, subfuscus. ffff. 30 slits in head and tail valves together, bowenii. dd. Riblets of lateral areas granulose, irregular, or much forking. e. Lateral areas with 3-4 rows of pustules, granosus. ee. Lateral areas with forking or meshing riblets. /. Riblets 8-10, fine ; slits in head and tail valves together about 40, i-iri/ulatus. ff. Riblets coar&er, netted ; slits fewer, stokesii. Umbo of tail valve about central. d. Mucro depressed, slope behind it hardly concave, pellisserpentis. dd. Slope behind mucro very concave, burmmttin. bb. Central areas with a smooth band or triangular on ridge of each valve. Murro in front of the middle. i-entral areas curved or converging, e. Lateral areas sparsely pustulose-lirate, viridis. ee. Lateral areas with interrupted or netted lira-. tubereulattu, , tusul'ir!*. ddd. Lateral areas with Lrrano>«- or noilo.-e ribs. •. Lateral areas with o-l, pleura '2~> riblets, iiril and girdle UDiform blackUb, mar '/(/. Finely Ix-adcd ; ihell and girdle banded, .^/////?no«««. 66. End valves finely striated. C. Shell oblon.ir. divergence about 110°. Shell elongated : divt-rp-m''' about 98°. f><»< AA. LATERAL AREAS SMOOTH OR CONCI:VI 1:1- M .1 .v w n.i'irRED. a. Whole surface smooth. b. Mucro near the anterior margin. c. Color black and olive-yellow, with snowy lines, (ilhu/in- cc. Purple or olive mottled. d. Sutural-plates within dark-blotched at base; sinus nar- row, ''j'ttiift. dr dark olive-brown, unicolored sometimes, but generally speckled on the side-areas and end-valves, often clouded on tin- central an of the valves having a dark stripe on the ridge. Lateral areas raised, sculptured with about -\eord-like radiatm- riblets, which are sometimes subcontinuous, but usually are much 154 « IIITON. interrupted :inr. II. Sharp at Toba-" i- aUo apparently .-«-v.-n-\ alved, having two of the valvei linnly loldered lit of an early injury. It is likely that the B6VOT and -ix-valved ( 'hit-. us :ihed by early author.- were partly abnormal specimen- of tins c'haraeter. and the rest \v iv (minded upon careless and MOO] Bgur Color-var. Color a uniform dull blackish ; rihlets of the central area- finer and coim-r^ini: near to the median line. Area behind the sinus in-ide, and the slit-rays solid, not spongy or pon.u-. nuda. I have 8681) a -reat number of specimens, but mostly BO <-roded that the permanence of the characters could not be decided. Yar. ASSIMILIS Reeve. PI. 33, figs. 61, 62. Fawn colored, with white dots on the lateral areas, the ctirina handed with brown ; girdle light green. Central areas «mtj>tured with very fine, close riblets. Interior having the >lit-rays and the area behind the sinus porous. St. Thomas to Barbados. Chiton f/.Wm/7/x KI:I:VK, Conch. Icon., t. 14, f. 76 (right hand figure) ; f. 77b. (March, 1847.) Color-var. ater. (pi. 33, fig. 63). Shell having the close fine sculpture of assimilis, but black in color, dark green-blue inside. St. Kitts (Rush) ; Tr'>niuitct>tte. Cf-nfrn/ urcua not sculptured, save for inconspicuous growth-lines. MIKTO of posterior valve near the front margin. Interior dark blue-green, the sutunil plates lighter. Sinus rudely denticulate. Anterior valve having 12, central valvt > 1. p >-terior !•"•»'> < IIITON. valve l:J slits. Kavos narrow, .-hort. somewhat spongy; sinus and slit-rays hardly porous. Teeth pectinated. Girdle alternately light green and whitish, covered with smooth convex-flattened scales. Length 60, breadth .".2 mill. Len-tli 4:», breadth 28 mill. Cuba, Jamaica, St. Thomas and St. Croix, West Indies. Chiton squamoms LINNE, Mus. Ulricae, p. 465 (1764). — Chiton niosus L., Syst. Nat. xii, p. 1107. — SpENGLEBSkrivter at' Natur- historie-Selskabet iv, p. 67, t. 6, f. 2 (1797).— HANLEY, Shells of LiniKeus, p. 15 (1855). NOT C/iiton squamosus of authors. — Chiton BPENGLEB, ]. >•.. p. 68 (a depressed form; see Chemn. viii, f. 792, 793). — Chiton scaber variegatus CHEMN. Abh., p. 31, t. 1, f. 3 ; Conchyl. Cab. viii, p. 276, t. 94, f. 792, 793.— Chitonfasciatus WOOD, Gen. Conch.. IS]."), p. 10, t. 1, f. 4, 5 (excl. syn.). — SOWB., Conch. Illii.-tr.. f. 1 .y;.— SHUTTLW., Bern. Mittheil. 1853, p. 74.— Chiton cheinnit-ii PKR., Krit. Register zu Mart. u. Chemu., p. 78, 1840. — Chiton marmorem REEVE, Conch. Icon., t. 12, f. 64 (not of Chemn. nor Fabr.) This species is colored in much the same fashion as some striped forms of C. marmoratus, and it also agrees with that species in the smooth central areas; but the dullness of the surface and the minutely beaded lateral areas at once separate the two forms. Specimens vary greatly in degree of elevation and consequently in the size of the angle of divergence. LiniKeiis gives an unusually full description of this species, amply sufficient to distinguish it from the shell which Born, Gmelin, and later authors confused with it. Spengler correctly identified it in his monograph of 17'.»7, and gave a most excellent figure and a good ription. Hunley found Linnaeus' original type still preserved in hi- eollertion, but the C. squamosus of authors is not present there. It should hi- noted that Linnaeus' specific names of Chitons were intended to In- descriptive of the girdle*, not the valves. rjUDIfl Spengler. PI. 33, figs. 64, (if), (Hi, 67. Shell oval, moderately elevated, carinated, side-slopes slightly con- vex. Color varying from gray-white to olive, irregularly marked on tin- central area- ..r on the rid«jo with blackish : some! lines hlack- hrnwn all o\ (ii i I..N. 157 Lateral ATOM strongly raised, :iml wulpturtd »•//// • low r'nli'itint/ rih.t Item-ing nf irrcgn/ur or regular inh-rrn/.-- rnumh'd j. I tin ,- ,r ///,,/ rior lionlrr of eacb valv gen< nil;. ticulated. OwUro/ oraoi tmoo^i hi the >/m/( nlmrt rilm f»'tit in ///»• .!.,• (Swift) ; Jamaica. Chiton *(]n, 70. Shell oval, rather elevated, the dorsal ridge varying from roundly- angular to distinctly carinated; side-slopes convex or straight. Sur- face smooth, polished. Color varying from olive to dark brown or purple-brown, variously marked with darker spots or blotches and liirht longitudinal stripes or lines. The lateral area- arc a little raised ; the whole surface showing a very minute quincuncial pattern of granulation under the lens, and marked with inconspicuous growth-lines. Mucro close to the front edge of the tail-valve, as in C. Icevigatus. Interior blue-green, each valve often having darker or olive pos- terior rays. Sinus deep, angular, having a jagged convex row of denticles, half as long as a sutural-plate. Anterior valve having 11- 14, mitral valves 1, posterior valve 13-17 slits; teeth deeply finely pectinated. Eaves, slit-rays and triangle behind the jugal sinus very porous. Girdle alternately blotched with green and light blue. Length 56, breadth 32 mill. Length 48, breadth 26 mill. Texas (Dall) ; Bermuda (Heilprin) ; Jamaica (Cpr.) ; Cuba ; St. Thomas (Swift) ; St. Croix; St. Vincent (Sharp) ; Barbados (Rush) ; Carthagena, U. S. Columbia (Krebs.) Chiton marmoratus GMEL., Syst. Nat. xiii, p. 3205.— (Chiton marmoreus CHEMNITZ, Conchyl. Cab. viii, p. 282, t. 95, f. 803-805. Not C. marmoreus REEVE). — C. marmoratus Sows., Conch. Illustr., f. 148-150.— REEVE, Conch. Icon., f. 6.— SHUTTLW., Bern. Mittheil. 1853, p. 74.— DALL, Cat. Moll. S.-E. U. S., p. 172.— C. scarabceus REEVE, Conch. Icon., t. 12, f. 66. This species is excessively variable, but with all its variety I have seen no specimens having the pattern of the West Mexican C. l&vigatus and articnltifns. The following color-patterns are commonly met: 1. Entire surface of valves blackish-brown. This is not an uncommon form, being the C. scarabcRus of Reeve. 2. Olive, with fine flecks and lines of whitish, becoming confluent toward the middle. 3. Either purple-brown or olive, having longitudinal zebra-like stripes on the side-slopes. CHITON, This -pi-firs is amply dislin.Lrni.-hed from 1'. /nrlf/'ifn.-- hv tin- wider sinus, dillrtvnt Ooloriagj and l>y tlir iniirli more porous lines |f iiiLT toward llir .-Ills, and (lir eon>piriiou>ly pomii- triaiiL'l' under tin- dorsal ridi:r of each valve, as shown in li: Species of the West coast of the Americas. This is a natural jrroup of lar.Lre species, character i/fd bv the generally somber color, large smooth scales, and anterior nuiero. l! 1-, cent ral valve- 1. post valve I'J 11 slits; teeth stout, blunt, deeply pectinated. Kave- sliort and narro\v, spun. (iirdle - lig. -\ > strong, covered with .shining, convex, imbricating seal Lentil) '.)•">, breadth 60 mill.; divergence 120°. Valparaiso, C '// /'//'. Chiton mitgnijicus I)n., Diet. Class, des Sc. Nat. xii, p. 4-V> : I-jicycl. ^Feth., p. 680; Lam., An. s. Vert., ed. Dh., vii, p. 498.— J{I-:I-:VK, Conch. Icon., t. 1, f. 3. — Chiton latus SOWERBY, Catal. Sh. Tankerv., appendix, p. v, (not Ch. latus Lowe). — Chiton olivaceus FREMIM.Y. Zool. Journ. iii, p. 199, Suppl. pi. 16, f. 4. — Cliiton nfrlnhi* UAUNKS, Amer. Journ. of Science vii, p. 70, t. 3,f. l.(1824). Not ('. ttriiifns of authors. This large olive-black, blue-dotted species is remarkable for the evenness and smoothness of its sculpture. It is an unusuallv hand- some Chiton. C. MURRAYI Haddon. PI. 29, figs. 15-21. Shell apparently smooth, but really very closely and finely striated, the striae being roughened or interrupted ; greatly depre Anterior valve with radial stria-; under surface with eleven dis- tinct square slits, radial grooves distinct and perforated; teeth of insertion plate serrate. Intermediate valves narrow, tlatt. non-carinate, with sharp depres.»ed umbo, surface stria? longitudinal in central areas, radial in the lateral areas; lateral areas distinct, with slight-concentric ruga-, and with three or four >carcely apparent peripheral radial ridges, which die away toward the apex ; sutural laminae shallow, a single lateral slit, lateral insertion plates Ben juguni with nine rounded teeth, the central beiinr verv small. Pos- terior valve flattened, slightly umhonatc, stria- longitudinal on the anterior area, radial on the posterior an -a : under surface with seventeen distinct slits, teeth serrate : jugum finely toothed. 11 • II! I Color, upper surface ground color of shell a greenish- -rhtly clouded with dark brown and black ; umbones lighter ; on eacl of the latter the ground is yellowish: whole, wrimr «],ritik!fd with pale blue spots, which are bounded externally by a black line; on ••i-ntral areas, the spots run in irregular, oblique, hackwardly diverging lines, and have a slight tendency to confluence, but on the lateral areas and terminal valves the spots are irregularly scattered; under surface, pale sea-green, darker along the jugum, and with a dark spot at the umbones of the terminal valves. Girdle: upper surface with large imbricate scales, of which the exposed portion is smooth, the hidden portion being usually finely striated longitudinally ; color, dark green, with a tendency to form darker bands opposite the valves; in the angles between the valves a few of the scales are paler and yellowish in color; under surface with long narrow oblong white scales arranged in transverse series. < Jills extending along the whole length of thefoot, about fifty- live <>r >ixty in number. Length 12'5, breadth 7%3 mill. The following Chitons also have blue spots: Chiton magnificus Desh. and Chiton dvrjuncttu Fremb. The latter is also from Valparaiso, but it would be impossible to mistake these for Chiton murrnij'i. Superficially, this species bears some resemblance to loplcurut lentiginosus Sow. (G. B. Sowerby, 1840, Charles- worih's X. S. London's Man. Xat. Hist., and Conch. Illust., 1841, figs. 120, 121 ; Reeve, Conch. Icon., 1847, pi. xxiv, fig. 165,= Chiton letatu* KKAUSS, Die siidat'rikanischen Moll., 1848, pi. iii, tiir. -) ; but apart from the generic distinction, Suwerhy's species can be distinguished by the perfectly smooth shell, inconspicuous lateral an as. paler color of the shell generally, and absence of the external black border to the blue spots. I have given myself t Ill- pleasure of dedicating this pretty and distinctive little Chiton to Mr. John Murray of the Challenger Expedition. (Haddon.') Valparaiso, Chili on the shore. Chi \\ . Challenger Polyplac., p. 1>1, t. 1, f. 7; t. 3, f. la-le. • C. 8UBFU8CU8 Sowerby. PI. 38, figs. 19, 20, 21, 22. Shell < h-vated, carinated, the sidr-slopes nearly straight. Surface rather shining. Color dark olivi-hrown. or olive- raved will) brick-red, (or " copperat-jpreen or reddish, i ss tlamed \villi jet-l>lael Tin- lateral -in. -\\hai '. itli 11 inn ' - " , ii'/ti'-lt « rnpted by grow th-lines. Central I dptim-d \,\ irniwth-wrinkles. and by //m' /»ni*«/rtr "i- ,ilw)it or/-/*/ mi f/inj;-nnt of //<>- dnrnnl r'i<\ of Wive, Kml valves having radii like tin- l:it«-r:il areas, their uneven- ness iriviiiL: the valve a superficially pitted or tinely netted apt anee. l>eak of tail valve near the anterior margin. Intoriur pale l)Ini>h, the sutural-plates whiter. Anterior valve having 15, central 1, postrrim- valve 20 slits; teeth rather sharp- I, strongly crennlated inside and out; sinus-area spongy ; slits ami slit-rays coarsely sponiry. Kaves short. Girdle densely covered with fine, smooth, convex, shining, black or olive-black scale-. Length 4'J, width '24 mill.; divergence 110°. Island of Chiloe (Cuming) ; Chili. Chiton *nhi'n./'/ Reeve adopted the name .s/r/'"/'/.«, and figured the shell repi-e-eiited by Sowerby's fig. 3 of the " Conchological Illustrations." This is copied in our fig. 20. We are constrained by thetermc l»y's original description to adopt the folio wir nt. Typical tnlniscus Sowb. PI. 38, fig. 19. I'alt; ashy olivaceous green, streaked and mottled with black : imdinal seulpture all over the mitral areas, and radiating sculpture on lateral area.-, both .-tr": loped, the latter a little interrupted into regulations. The relations of this form with m ;ire inv« - 164 < I II TON. Y;,r. mesoghjjitns Pilshry. PL 38, figs. 20, 21, 22. Olive-brown or brown, unicolored or rayed with brick or blood- t he latter sometimes predominating. Central areas having a group of longitudinal striae on the dorsal ridge, but smooth or nearly so on the pleura. Smaller than the preceding. I have seen a considerable number of this form, which is the " var." described by Sowerby and figured in Conch. Illustr., fig. 41. I am unable to say whether it intergrades with the true subfuscusor not. C. BOWENII King. PL 38, fig. 23. Shell large, elongated, elevated, the dorsal ridge car in ated; red- dish-chestnut, olive, or ashen streaked with olive. Mucro in front of the middle, the slope behind it straight. Central areas smooth, sometimes with delicate longitudinal strise at the ridge ; lateral areas elevated, delicately radiately striated, the end valves similarly sculptured. The entire surface is microscopic- ally granulated in quincunx pattern. ln>ide having 13 slits in the anterior, 1 in the central, 17 in the posterior valve; teeth pectinated, eaves small; sinus wide, flat, with 12-16 teeth. Girdle olive-brown, in all the varieties of valve-coloring ; scales solid, rounded, regularly imbricating, and small for the size of the shell. Length 82, width 38 mill. ; divergence 98°. Length 68, width 32 mill. Strut ft of Magellan. Chiton bowenii KING, Zoolog. Journ. v, p. 338 (1831 or 1832).— SOWERBY, Conch. Illustr., f. 37. — REEVE, Conch., Icon., t. 2, f. 9. — SMITH, P. Z. S. 1881, p. 35. — ROCHEBRUNE & MAT.II.U:. Moll. Cap Horn, p. 141. Distinguished by its comparative smoothness, unusually elongated form, and highly ridged back. C. CUMINGI Frembly. PL 30, figs. 29, 30, 31. Shell oval or oblong, elevated, the dorsal ridge angular, side- slopes nearly straight. Whitish or olive, very closely and regularly d with brown or lead-colored lines which are concentric on the end valves and lateral areas and converge forward on the central. areas; often blotched on some or all of the valves with lead-brown or buff. ( III 1 Tin1 lateral an. parated from the central area- l»v an oblique curved ridge, hut scarcely raised; sculptured with*; or 7 low radiating riblets, somewhat dedicated by longitudinal sub- ol)st>lete riblets. The central aiva< are sculptim-d with Longitudinal rildets liner than those of the lateral areas. End valve.- having radiating riblets and less distinct concentric lira-, the iimbo of po.— terinr valve near the front margin. Interior pale bine ; sinus flat, toothed; anterior valve having 10, central valves 1, posterior valve l.'J slit>; teeth blunt, pectinated. Girdle clothed with smooth, convex, imbricating scales. Length 53, breadth 34 mill. Length 56, breadth 31 mill. Valparaiso, Chili. C. cumuiynii. FRKMI'.I.Y, Zool. Journ. iii, p. 198, suppl. pi. 16, f. 3. — C. cwningsi DH. in Link., An. s. Vert, vii, p. 500. — C. cumin '/ii, SOWB., Conciiol. Illust., f. 32.— REEVE, Conch. Icon., t. 1, f. 2. This well-known species is of a bronze-olive color, closely lineated with brown or olive. The lines are not distinctly -enough shown in the figures. The range of variation in contour and color-pattern is considerable. It has been reported from the Cape Verde Is. (Nouv. Arch, du Mus. 1881, p. 282), but there cannot be much doubt that the citation is based on a false locality label. C. STOKESII Broderip. PI. 30, figs. 25, 26 ; pi. 32, figs. 50-53. Shell oval, moderately elevated or depressed, the back cariuated, side-slopes straight. Brownish-black, toward the middle often more or less marbled longitudinally with dirty white. Lateral areas somewhat raised, closely sculptured with radiating, irregularly gntnnlous and anastomosing riblets. Central areas sculptured throughout with low close longitudinal riblets, often made slightly granose by the lines of growth. End valves covered with a net-work of nodose riblets generally very much interrupted ; umbo of posterior valve near the front margin. Inside smooth, varying from blue-white to light blue, the sutural plates paler, all of the valves marked with a spot of dull brown. Sinus deep, rather narrow and angular, jaggedly toothed. Anterior valve havinir 1<>, Central valves 1. posterior valve 15-16 slits. 166 ( HITON. ( .irdle (pi. 32, figs. 53) covered with solid, convex, subcarinated imbricating scales. Length 68, breadth f>0 mill. Gun?/ . II >>•> Mexico, to Panama and West Coliunhin. Chiton stokesii BROD., P. Z. S., 1832, p. 25.— S,,\vi;.. Conch. mufltr., f. 24.— REEVE, Conch. Icon., 1. 1, f. 4.— M..I:< H. Mai. 151. vjj p 171; — Chiiun jtnttilu* Sown., Charleswortli's MULT. Nat. Ili.-t. . p. •_".»! : Conch. Illustr.,f. 134.— RKKVE, Conch. Icon., f. 30.— >il,fn.< CPU., J/\ The sculpture of the lateral areas is peculiar, being something like the meshes of a stretched net, but the cords or riblets are irregularly irranulose. In uniting the C. patulus of Sowb. to stokesii, I quite agree with Carpenter, who writes as follows: The form patulus is typically " engine-turned " on the terminal valves, with strong ruga? on the sides, and larger scales on the girdle. A young specimen sent by Mr. Cuming has only 18 slits in the tail plate. The typical stokesii has the terminal rugae radiating, and sometimes a row of color tints at the sutures. The bulk of the Panama and San Juan i niens (of which I have examined many hundreds) are so variously intermediate between the two forms that I find it impos- sible to separate them even as varieties. The scales are extremely deciduous, and specimens in good condition are not often found. It was often the custom of Mr. Cuming to select extreme forms for his cabinet; and these being described and figured as the normal types of species are very apt to mislead students who work by single specimens. ( '. vi 1:1.1 i. \ rrs Sowerby. PI. 32, figs. 54, 55, 56. Shell ohlonir, parallel-sided, rather elevated, the dorsal ridire ear- inated, side-slopes straight. Lateral areas and end valves olive- brown, or like the central area< which are green, longitudinally cl..iided with blackish : girdle jinn ami W/W. t ransversely or longitu- dinally banded. The lateral areas are raised and -culptur.-d with rwmenut s-10) ifiti'i rifift.'t-*, irli ic/i /mi' "-// //, sji/it or branch. Central areas sculptured with longitudinal rihlets which at the sides diverge a little and are nearly as coarse as those of the lateral areas, hut finer and parallel to the rid^e toward the middle. Km! valves having dose radiating riblct> : ap. \ of tail valve ante) i In-ide dark I>1> sutural-plates hi'jh. blue-irr- en. Sinus angular and tootln-d. Ant-.i-r valvi- liavinjr '1\-1'1, <-cnh*///'"/ Calij - WB. in Charlesworth's Mag. Nat Hi>t. 1840, P. L'!»I ; Conch. Illustr.. 1'. 132.- REEVE, Conch. Icon., t. 21, f. 140. Thi> species is allied to ('. N/fi/w//, hut differs in bring narrower, more elevated, dilierently colored, in having the riblets iim-r. inoj-e nunuM-oiis and less anastomosing, in the color of the interior and in the iinmher <>f .-lius which is much Lfi'eater in the end valves of this species than in those of C. ttnketii, and in some of the intermediate valves there are two slits in one or both sides. The entire surface, as usual in this genus, is microscopically granulated. The girdle- scales are liner and smoother than in <". s/o/r*//, and the sutural- plates are different in form. A square mm. of the girdle is shown by the dotted line in fiir. ~><>. It has been reported from Australia, but erroneously. Many spec- imens are before me from the localities given above. The remarkable feature of this species is that it forms a perfect transition between the restricted genus Chiton and the section /iV/>/ a >•. x. C. GRAN08U8 Frembly. PI. 30, figs. 27, 28. Shell oval-oblong, moderately elevated, scarcely earinated, the side-slop«-> somewhat convex. Black, having a white stripe <»t e i the central l'm<\ clouded with whitish between the .-tripes. Lateral areas bearing three or/'"/.-- "'n'nt ; V, ('hill. 1'liiton fjrano*n* FKKMKLY, Zool. Journ. iii, p. 200, suppl. pi. 17. f. 1 (1827). — Dn. in Link., An. s. Vert, iii, p. 500. — SOWB., Conch. Illustr., p. 2: Moll. iBeechey's Voyage of If. M. S. 'Blossom,' t. 4<>. f. .">. — IIi:i-:vi:, Conch. Icon., t. 5, f. 27. — LojJii/rti* (j,-an».-«i* TAP. < IAN. Viag. ' Magenta' p. 75. The pustulose lateral areas and end valves and the black, two- striped color-pattern are the stronger features of the exterior of this- nid the interior is no less strongly marked by the trans- wrinkling of the front part of each valve, which may be readily seen under the lens without dis-articulating the shell. This wrink- ling in other species is confined to a band the width of the sinus, and is much le.-s strongly developed. The second valve is broad and beaked, with only a narrow smooth dorsal line : the following valves have a distinct smooth band. ( . 8TR1 vn N9QUAMO8U8 ( 'arpenter. Shell s'ibrotund, depressed, pale brown-olive ; entire suriace of the valves densely granulated : lateral areas rather distinct, valves wide, .-liirhtly curved, scarcely beaked; jugum scarcely distinct, very delicately longitudinally striated, lateral margins planate : mucro iior. -lightly distinct. Girdle furnished with solid, oval, large hardly crowded scale-, part deeply siriated : maririns <>f t he valves serrated ; median valves with a .-ingle .-lit on each side, end valves having about 12 slits: .-iitnral-plate- i '".-ly arcuate. Length } . l.r.-adth 3, alt. 1 mill.; divergence 140°. (Cpr.) M'l-'itlnn, on Si»nnihjln>- <•<> ••/»'/mo.s/'.< < i'i:.. ( 'at. Ma/at. Sh., p. 1•/ ///.« kTiLia Reeve, PL W I, 84, Shell OVftte, valvr< very e|..ea irreen. A peculiar smoothly bronzed shell, painted across the middle with narrow hands or ripples of green. (Reeve.) •sima} ./•///'///. C. aqiidtilis REEVE, Conch. Icon., f. 7-'5. Reeve gives no locality for this species. The figures on my plate are copies of his. Carpenter writes as follows of Reeve's type specimen : One spec- imen made up of two, only the valves stuck together. I counted just eleven scales in one corner, though Reeve describes and figures it as complete. The very insertion-plates are in great measure rubhed off. It may equal my C. densiliratus in poor condition. Anterior valve having 10, central valves 1, posterior valve 1:5 slits ; teeth pectinated ; eaves short. Shell rather elevated, the dorsal ridge sharpish. Central areas with extremely close fine parallel striae, jugal area not defined. Lateral areas not elevated, having 1 ^ radiating lines, extremely close and fine, as on central areas, but rather more developed ; the end valves similarly sculptured, mucro in front of the middle; posterior slope very concave. Marked "? Japan"; and the habitat of a specimen sent by Damon for pur- chase is Tsu-Hina, Japan. The valves alone, without -'irdle, and irregularly placed measure: Length 40, breadth 23 mill.; divergence !<)."> . C. PKNsiuuATrs Carpenter, n. sp. Shell oval, solid, elevated, the jiiu'iim acute : mucro scarcely prominent, subantcrior. Ashy or pale bmwii, irregularly clouded with chestnut or black, often eleirantly dotted with darker or paler. Central areas having about *2~> rildet< on each side of the juurum and parallel with it, obsolete at the rid;re: lateral area- well defined, having S-10 line, sometimes bifurcating; end valve< having *: such line. 170 CHITON. Inside: anterior valve having 8 ; central ralvefl i. posterior valve 18 slits; teeth normal, very closely pectinated ; sinus narrow, havinir about 1 1! minute denticles. idle unicolored or tessellated, bearing normal imbricating scales which here and there are very minutely Mriatulate. Length :>s, width 33 mill.; divergence 110°. ,I name was given by Garrett or by Tryon I do not know. C. PBBVIKIDIS Carpenter. Shell small, narrow, elevated, thejuirum acute: color an im green. Entire surface very minutely scaly under a lens: lateral areas and cud valves radially I irate, tin- line obtuse, little con- spicuous, 4 or ~) on side-areas, 2"-L'"> <>n end val\ ' iral areas (Ill : 171 having about 1 '_' little impressed, di>lant siilci, parallel to tin- slits in end valve-, I in median valves; leetli a deeply peetinated -hurt; .-inns wide, Mat, toothed. (Jirdlc furnished \vitli large, solid, imbricating but Mriated Males. Length Hi, wi.lt h 6$, alt. .°» mill. TaM C/ilfnn ( Loj,hi/rii.^ itt'i-viridi* CIM:., I*. /. S. 1M'>.~>. p. 511. L»/>li'j- ri(.-i ptrviridit PEASE, Amer. Journ. Conch, vii, p. I'M. A solitary s])ecimen of this interesting species is very like ( '. v!re«- Kve. in general appearance: but the mantle of tiiat species is nearly smooth and the valves scarcely sculptured. This shell a uniform bright green. It has the aspect of Le]n'dltj,/n.nru.< | Lepid- ozona] ; but the insertion-plates though sharp, are deeply pectinated. It differs from most other Chitons in having the scales di>tinctly striated, as in C. 8friato«f]uamosus. (Cpr.) C. P.URMANUS Carpenter, n. sp. Shell elevated, with acute dorsal ridge ; olivaceous or red, Imciny a white blotch <»i the tail vahe behind the mncro. Whole surface of the valves finely quincuncially granulated ; central areas havinir nlmut '20 .n c<«-I> parallel to the dorsal ridge, upon which they are finer and cl lateral areas having 3 to 5 roiv* of stout granules, some of the rows not reaching to the apex. Knd valves having -'"> (or fewer) rows of stout granules. Mucro of the tail valve median, the slope behind if very concave. Interior having 8 slits in the anterior, 1 in the median, 1 1 in the posterior valve; teeth sharp but distinctly pectinated : » aves -hurt. Girdle covered with rather roundish oval scale.- of larue >i/e. Length 19, breadth l<).l mill.; divergence %°. < 'u'i*f nj AfiL-'i/i. />Y///V/ Jtui'inuh, under st«»m-s at lu\v water. The British Museum contains four sj)ecimens, of which three are olivaceous, the other red. The above description is from ( ar- penler's .1/N. //'/, JNV?r Zt'itliDnl. The S])ecies of tli re mostly of moderate or small - and generally the muem is central and the scale- mieroscopicallv striated. 1,1' CHITON. C. QUO vi i I. PI. 37, figs. 6, 7, 8. Shell oval, rather elevated. carinated, the side-slopes straight. Surfac.- having a smooth and polished appearance luit very finely striated. ('»!»,• generally a veni '/a/7; olive-green, hut sometimes yelli)\vish brown marked with olive on the sides and ends, or clear yellow with rays of olive or brown. Lateral areas slightly raised, sculptured with numerous narrow, delicate and slightly erenulated radiating threads. Central anas covered with still finer longitudinal striae. End valves sculptured like the lateral areas, the two about equal in si/e ; ninero of the rather raised tail valve a little in front of the middle. Interior sky-blue, marked under the beaks with olive-brown rays. Sinus rather square, finely denticulate. Anterior valve having 9- 10, central 1, posterior 13-14 slits; teeth erenulated outside. Girdle covered with smooth convex imbricating scales, mostly li.irht blue, but often having dark brown scales mingled with them. Length 37, breadth 22 mill. .1 iK-klnml to Dunedin, New Zealand, in pools under stones, between ti«les. Chiton rirnHs Q. & G., Voy. Astrol. iii, p. 38^., t. 74, f. 23-28 (1834). Not Chiton e.rtn* r/Y/-, hifn* c" >/'//'///* of Chemnitz, Con- chyl. Cab, viii, p. i>77, t. 94, f. 794, 795 (1785), nor t'A. viridit Sprn.irler, if. r. — C/'itnn (jnoyi DESH. in Lam., Anim. s. Vert, vii, p. . 1836).— Ki.i:\ i, Conch. Icon., t. 13, f. 68 (1847).— Chiton glawsu* HITK.N, Man. N. Z. Moll., p. 112 (1880.) ? C/tifon (/fa urn* GRAY, Spicilegia Zoologica j)t. i, p. 5 (1828). — ': /.--//A >/ /•//* r/l•; but I have not been able to confirm this by the compari-on nf -pecimens from the latter locality, which may safely l>e omitted until authoritatively con- firmed. The locality of Gray's ('. ylnim.* was unknown, he did not figure hi- -pccimen, which had lost its girdle, and lie states that it was whit.- in-ide. -Ian- outaide, The identification ofQaoy and (iai II d. -cril.ed aiid fi^ureil shells from New /.'aland with « III : 17-". have seen Cray's type, and its ijrnrrir eharaeters, are wholly unknown. I hav«- never leeo a "gb|UCUI linen of this species "wluteioside;" they arc always blue. The cbi of name made l>y Deshayes must be adopted on account oi earlier ('. riri'H* of Spender. ('. PELLI88ERPENTIB <,)iioy & Gaimard. PI. 37, figs. 14, 15, 16, 17, 18. Shell oval, rather elevated, hardly cari nated, the side-slopes some- what convex. Surface lusterless. Color a rather dull and din-y olive or olive-green marked with black along the ridge and on the sides of some valves. The lateral areas are moderately raised and sculptured with 3 or 4 roir* of Distinct tubercle*. Central areas having *tronirf/i irrinklc*, elli*-«erpenti« KEKVI:, Conch. Icon., t. 15, f! 84.— HUTTON, Cat, Mar. Moll. N. Z. 1873, p. 4C : Man. N. /, Moll. 1880, p. 111.— HADDON, Challenger Polyplac., p. '2'2. This is one of the most abundant New Zealand Chitons. Its sculpture is frequently obscured or lost by erosion. C. sim'/nirl is closely allied, but it differs in color-pattern, in the poll." licit central areas, whilst the surface of pelli«-*erpenfis is lusterless, and in the sculpture of the central areas. The median valves of pellisserpenti* 174 i HITON. are rather stronirlv arrhed hack ward, and the broad sinus is remark- able for the absence or obsolescence of teeth. The interior, except just behind the .-inns, is smooth ; the callus in each valve is heavy and smooth. Figures 14, !•>, 17 arc drawn from Auckland, X. /. examples, furnished by Mr. < J. W. Wright. C. SINCLAIRI Gray. PI. 36, figs. 1, 2, 3. Shell oval, rather elevated, the dor*«l ridge rounded, side-slopes rather straight; brown-black, each valve irregularly and raggedly Hh whiti*h; the head valve pale with dark rays. Some- times the white predominates. The lateral areas are raised and sculptured with three or four i-'id luting grano«e rib*, often *nbobsolete. Central areas xmooth in the middle except for a few growth-wrinkle*, but having fine .«hort lougitu- •<> the ."life." in front of the diagonal line. These riblets are sometimes almost obsolete. Head-valve sculptured at first with about 15-18 granose riblets, but as these have a tendency to split as the valve grows, the number in a grown specimen is usually 24-30. Tail-valve having a low, obtuse mucro, decidedly in front of the middle. Interior bluish. Sinus rather wide, denticulate, the area behind it porous. Anterior valve having 11, central valves 1, posterior valve 14 slits; teeth obtuse, strongly crenulated. Eaves broad, _y. Girdle (pi. 36, fig. 3) covered with large, convex scales, which are very finely, sharply striated. Length 28, breadth 18 mill. Length 17, breadth 11 mill. New Zealand (Sinclair, Hutton, Wright.) Chit"n ."'nn-lnu'i ClHAY, in Dieftenbach's Travels in N. /. ii, p. 263 (1843).— HUTTON, Trans. N. Z. Inst. iv, p. 177 ; Man. X. /. Moll. p. Ill n«.sO).— SMITH, Zool. ' Erebus' and 'Terror,' p. 4. t, 1, f. 17.— REI-:VE, Conch. Icon., t. 22, f. 143. The smooth, polished central areas, grooved only al..ii'j the • nal line at t he sides, and the granoa6»lii>bed lateral area< and en 1 valves are characteristic, and remind one of the \Ye.-t Indian ( '. The black-and-white coloring also is rather constant. The ivas varies greatly in stn-n^th. This s-pecies has been reported from Tasmania, but mi doubtful authority. ' III ( '. i Souverbie, I'l. <'»">. il^. •'!, 4. Shell ovate-ohlonir, the hack earinatt-d, nmhoiMS HihroMi -ii «.r yrllowish-ivd, with lonr.) ( . MTRICATUS A. Adams. PI. 37, figs. 12, 13. Shell oblonir, much elevated in the middle; black-brown and white variegated. Knd valves and /titrml urem* n/'/m/r/// i-illictl, the ribi Ornamented n'if/i dcmlcd acute f/niinn: tail valve umbon- ated in the middle. Central areas longitudinally deeply lirate, the umhoiics smooth, elevated, somewhat produced. (Jirdle scaly, the scales mucronatcd, imbricating, with subenrt apices. 1 , t ; ,in Tliis species is remarkable for the somewhat triangular imbricate BOalefl of the ligament ending In slmrp i«>iutc. /. S. 1865, p. 186; 1867, p. 222.— Clnt»n /ini'ins and C. carn»*n* CIM:., J/.s'N. Varies in color from dull green to orange and bull'. Carpenter examined Adam's type of this species, and ascertained it to be identical with his own unpublished (.'. li»iefore me, indicates the following as the m<»t important characters of cnrnosmt : Central areas having about 18 suhparallel -ulci on each side, more prominent toward the margin, obsolete toward the jugnm ; lateral areas and end valves having irregularly (at the sutures strongly) nod.»e wrinkles, 4 in number on the >ide areas, 22 on the anterior, 14 on the posterior valve, i 111 1.7 hi fin-cat iii'j:. Interior: anterior valve with*, central 1, post valve- LOsliti, Length 80, breadth ir> mill.; divergence l< Ka-ily rec«»_i:ni/ed by the ilesliy color and small, beaked, ma: scales; the side sculpture of /imotw (with which this species agrees in the scales) 11 very diflerent in pattern. (Cpr.) (\ c \\\\.\<-( \.\v\ > (^imviV radiating ribs which are regularly cut into low beads, and which often split toward the lower margin. Central areas having a narrow smooth space upon the ridge, sculptured on each side with about 16 strong longitudinal ribs, separated by deep intervals ; posterior mar- gins of valves crenulated. Anterior valve having about 22 granose radiating ribs ; posterior valve having about 16 granose radiating ribs, the umbo slightly in front of the middle, the slope behind it a little concave. Interior whitish; sinus rather deep and narrow. Girdle covered with compactly imbricating, convex, shining obso- letely striated small scales (pi. 36, fig. 6.) Length 14, breadth 11 mill. Ta*man Bay's (Q. & G.), and Stewart Island (Hutton), Xew Zea- land. Chiton canalicnlatus Q. & G., Voy. Astrol. Zool. iii, p. 394, atlas, t. 75, f. 37-42 (1834).— Chiton stangeri REEVE, Conch. Icon., t. 22, f. 150 (1847).— Chiton insculptus A. ADAMS, P. Z. S. 1852, p. 91, t. 16, f. 4.— ef. HUTTON, Man. N. Z. Moll. 1880, p. Ill, 112. Allied, in its acutely elevated contour, to C.,/".'/"*"^, but differing maikedly in the granose-ribbed lateral areas. It is usually very brilliantly colored with rose-pink and buff) but olivaceous torn i- occur. The latter may be distinguished from C. *uit'lairi by the differently sculptured central areas. Professor Hutton (in lift.) suggests to me the identity of stangcri and inm'iiljtt'i*. The latter seems to agree altogether with (Buoy's oanaKcMlatut. The girdle-scales (pi. 36, fig. 6) are smaller than in ('. jiignsus, and they are much less distinctly striated than in ('. ,s///" pettiuerpentis. 178 ( II1TON. ( '. .injosus Gould. PI. 36, figs. 91, 92, 93, 94, 95. Shell oblong, much elevated, carinated, the side-slopes straight and steep. Central areas sulcate at the sides, smoufli in the middle, literal urea* smooth. Color light green, the ribs of the central < >/e, lateral areas with fine alternating concentric lines of yellow and green. The lateral areas are strongly raised and smooth, painted with close lines parallel to the dorsal keel. Central areas having a smooth triangle in the middle, the sides sculptured with 11-14 strong rounded orange colored ribs, separated by deep, blue intervals of the same width. Head valve smooth, concentrically lineated ; tail valve concentrically lined at the sides, having a broad triangular buff or orange ray behind, extending across the girdle ; apex project- ing slight li/ behind the middle, posterior slope strongly concave. Interior blue-white, the sutural plates white. Sinus narrow and angular, denticulate. Anterior valve having 8, central valves 1, posterior valve 12 slits ; teeth blunt, pectinated. Eaves spongy. Girdle (fig. 95) buff and greenish, irregularly alternating, covered with compactly imbricating, polished convex scales, which are obso- letely striated. Length 35, breadth 20 mill. Port Jackson, Sydney, N. S. Wales, Australia. Chiton jagosus GOULD, Proc. Bost. Soc. N. H. ii, p. 142 (1846); Expl. Exped. xii, Moll. & Sh., p. 317, atlas, t. 28, f. 430 (1852).— SMI in, Xool. Coll. H. M. S. 'Alert/ .p. 78 (1884).— HADDON, Chall. I'olyplac., p. 22 (1886).— Lop hyr us jugosus GLD., Otia, p. 3, 242 (1862).— ANGAS, P. Z. S. Lond. 1867, p. 222.— C/nton concsntricns Ki i:vi:, Conch. Icon., t. 16, f. 95 (1847). — Lophyrus concentricus ANGAS, P. Z. S. 1867, p. 221. The peculiar and beautiful coloration separates this species from its allies. The second valve is frequently blood red, or blotched at the sides with dark sepia; and occasionally all or many of the valves have blotches of buff interrupting the longitudinal color-lines. The light triangle radiating backward from the- uinho of the tail valve is present in every specimen I have seen. The tail valve, indeed, i « in Sin Is one somewhat of that of an irregular Chiton. Tin- paintiiiLT of tin- lateral areas gives the impression that they are longitudinally ribbed, as Reeve and An.iras havr dcscrilx-d : but even in Reeve's tyj>e8 these areas are quite .-month, as they are in all the specimens I have seen. 179 This sp.-eie- has hem reported from New Zealand, hut probably incorrectly, ('. ITI.VIN \ rrs ( 'arpenter, n. sp. Shell small, oval, suhelevated, with acute jiiiruni : IMIHTO median ; apie»-s ot' the valves prominent; olivaceous and !>ro\vn variously clouded and irregularly painted. Kntire surface minutely punet- ulated ; mitral areas hari nout.l6 deep su lei on each side; lateral «','// (lejiiH'd, H en rh/ smooth, as are the end valves also. Interior: anterior valve having 10, central valves 1, posterior valve !> slits; teeth acute, deeply serrated ; sinus moderate, dentic- ulate. ( Jirdle covered with large smooth scales. Length 0, width 4* mill.; divergence 110°. (Cpr.) New Ireland (Mus. Cuming, no. 78.) Distinguished from Inzonicus by the smooth scales and side-areas, which display a velvety appearance under the microscope. C. yEREtis Reeve. PL 36, figs. 96, 97. Shell oblong-ovate, angularly raised in the middle ; valves rudely impressly striated throughout, umbonal eminence smooth. Dull green ; ligament granosely coriaceous. The color is a uniform dull green except along the rubbed umbonal summit, where it has a copperas hue. (Rve'} New Zealand (Earl.) Chiton cereits REEVE, Conch. Icon., t. 7, f. 36 (1847). — Chiton (Leptochiton) cerens SMITH, Zool. Voy. ' Erebus ' and ' Terror ' Moll, p. 4, t. 1, f. 9.— CA. siculoides CPR., MS. This species has been referred by Smith to C. siculus Gray. The locality requires confirmation, as it rests solely upon Cumingian specimens. Hutton (Man. >.'. 7. Moll.) reprints Reeve's diagnosis without comment. Carpenter's notes on Reeve's type are as follows ; Central areas having about 20 furrows on each side, not deep, continuing until they are rubbed off in the middle; lateral areas having 4-8 divari- cating riblets, much worn, broken up by the concentric ruga of growth; crenate at the sutures; end valves with about 30 riblets. Mucro in front of the middle, posterior slope concave. Interior 180 < I II TON. bluish, sinus with ~>-13 denticles, deep, narrow; girdle scales stout, roundish. Length :J!», breadth 23, divergence 94°. One specimen, New Zen land, in Mus. Cuining. Species of the Mediterranean and African Seas. The species are allied to those of Australia and New /ealuml, the iiiucro in many of them being central, and the scales striated. C. OLIVACEUS Spengler. PL 35, figs. 87, 88, 89, 90, 91, 92. Shell oblong, elevated, carinated, the side-slopes strain lit. Surface ribbed and microscopically punctulate. Color very variable ; either black, brown, scarlet or olive-green, unicolored or clouded or mottled. Lateral areas raised, sculptured with 4-6 flat Ion- rndi'tfi:ii/ ribs, the posterior rib widest, separated by narrow shallow grooves. Central areas having a smooth triangle on the ridge of each valve, the sides (pleura) bearing strong longitudinal ribs, which become stronger toward the outer margin. End valves having low radiating riblets. Tail valve having a conspicuous central apex, the posterior slope somewhat concave. Interior light bluish, marked with brown rays in each valve. Sutural plates rounded ; sinus deep, square, denticulate. Anterior valve having 7-8, central valves 1, posterior valve 8-10 slits ; teeth blunt, pectinated. Eaves spongy. Girdle wide, banded with alternate light and dark, compactly covered with minute smooth, convex scales. Length 36, breadth 20 mill., often less. Mediterranean and Adriatic Seas ; Cape Verde Is. Chiton squamosus POLI, Test. utr. Sicil. i, t, 3, f. 21, 22 (171)1) and of PAYRAUDEAU, COSTA, and PHIL., Enum. Moll. Sicil. i, p. 106, t. 7, f. 3; and of Granger, Moll. France, p. 170, t. 12, f. 16 (1885). Not of Linne*. — Chiton olivaceus Sn:v.i.r.K. Skrivter af Naturhistorie-Selskabet, iv, p. 75, t. 6, f. 8a-c (1797).— Jeffreys, Rep. Asso. Adv. Sci. 1873, p. 113. — MONTEROSATO, Enum. e Sinon. p. 17.- Bn>. DM i/. et DOI.I.F., Moll. Mar. du Rouss. i. p. 489, t. 61, f. 4-6, t. 62, f. 4.— LOCARD, Coq. Mar. des Cotes de Fr., p. 232 (1892).— Ch. , EtaBO, Hist. Eur. M.-rid iv, p. 268.— Ti m 1:1. Bull, della Soc. Malac. Ital. iii, p. 145. — Chiton siculus GRAY, Spicil. 7,ool., p. .", ; Pun.., Knuiii. Moll. Sicil. ii, p. S2.— Wrix- KAUKI, Conchyl. «l<-s Mittdm. ii, p. 408.— REEVE, Conch. Icon., t. ">; t. 16, f. 97 (lowest fig.); t. 19, f. 12l.— Gli/mnopl>ix < III K". mm:., NOIIV. . \n-h.du Mn~. 1^*1, p. 242, ' 'A///,// ;,/,/// |)i-n. (not IMiil. I de Morfe, iii, |>. 132; Lamk. .-.lit. Dl,., vii, ]). .~>(U. — C. #/////•//>• . < IIITON. SAVK.NV, iWript. de 1'Egypte, Gasterop., t. 3, f. 9.— Chiton Malar. Mar Kosso, p. 234 (1869). — C. .« de1 Tortaori d«-lhi due Sicilie, p. i, iii, t, 1, f. 2 (Naples, 1829); Fauna di Napoli, Aniiu. Mulli, Chiton, p. 8. — Chiton j». Ai-ir. Invert., in K«-p. i::th in.M-tin- Urit. Asso. Adv. Sci., for 184:;. ,,. i-s'^j (1844). — C. scytodern .\\, < '. /,// /'//;>;, // . 111 roiTi The prominent features of this little sprri»- >lor, Lrreat elrvatioli. like a -"thie roof, and the sculpture. Thi- ifl imt identical with the LepidopleUTUA mr at, <'"i» ]'>,•>!• A. Qymnoplax ///. mill. (Sowb.*) This shell is ><> thin as to be nearly transparent; it is smooth, ratlin- amrulated in the center, the lateral areas smooth, slightly elevated, the central areas marked with faint longitudinal ribs. The margin is covered with regular, minute scales. The general color is drab, variegated with brownish concentric lines at the sides and reddish-brown dorsal bands on some of the valves. (Swb.) Jfnltitiit Hiihnoirn. Chit'm ////•'////>• Sown, in Charlesworth's Mag. of Nat. Hist. 1840, p. 293 ; Conchol. Illustr., f. 126.— REEVE, Conch. Icon... f. 110. This shell should be compared with w//'//-fV//*/x Orb. and tli.<- .«ini!/i* Reeve. Carpenter has described a C. xr////A/-/-/'x in MS. from Cumingian specimens of unknown locality. It will probably prove to be a form of the above species. Reeve reports C. lyr'tin* from Prince Island, West Africa, under stones. C. DISSIMILIS Reeve. PI. 37, fig. 11. Shell oblong-ovate ; terminal valves and lateral areas longitu- dinally grooved, smooth in the middle ; variegated with reddish- brown ; ligament granosely coriaceous, tessellated. Approximating in some measure to the C. tu/ijut. (J£mr.) Ifufiifilt nnkiinirii. C. f//W//////* RKKVK, Conch. Icon., t. 25, f. 170 (May, 1847.) Reeve s description does not correspond very well with his figure ; and the species will probably prove to be the same as C. mnnrii //>•/.< Orb. Carpenter notes that in Reeve's type specimen the whole surface is conspicuously quincuncially granulated. The anterior valve has 9, central 1, posterior valve 13 slits; teeth sharply pectinated. It measures, length 18, breadth 9 mill. ; divergence 90°. C. CAN M:M .Nsisd'Orbiirny. IM. :!4, figs. 77, 78, 79. Shell oblong: carina smooth, central areas of the valves longitu- dinally sulcated, lateral areas smooth; ends smooth: margin granulate-scaly. Length -J4, width 12 mill. (Orb.) CHI The shell is oldon-, a 1 it I le ea ri mite, I ; the intern xillnnf/i nt tin fiiriiiii, iiKirlcrtl nu < nr/i *iy deep grooves; the /»//»/•»// i> are verv variahle : sometimes marbled with Mark and brown spots on a white ground, sometimes with some valves quite Mack or ^roi'ii. the others spotted. Tin- irirdle i> radiated with Mark, gray and white. (Orb.} CHIHH-II [«. (Webb and ]>erthelot.) ( '. rinmrieii*i« OKI;., in Webh tt Berth., Hist. Nat. des lies Canaries, Moll., p. !W. t. 7, f. 16-11). — Chiton (JLophurw?) riiiini-irii.*!*, SHUTTLW., Bern. Mittheil. 1853, p. 81. Allied to C. o///wr//x, but differs in having the lateral areas and end valves smooth. The interior, according to Shuttleworth, is green, with spots of rose and purple. This species should be com- pared with C. lifrntti* Sowb. C. TULIPA Quoy & Gaimard. PI. 31, figs. 43-49. Shell oval-oblong, elevated, acutely carinated, the side-slopes nearly straight. Snri'nrr #ntonth and polished throughout. Ground- color buff or whitish, suffused and closely mottled all over with red- dish-chestnut, fawn, or purple-brown ; usually longitudinally streaked on the central areas, zigzagged or tessellated on the end valves, and articulated on the diagonal lines with the darker color. Sometimes parts of some valves, or several whole valves are of a uniform dark brown color (figs. 43, 45.) The central areas are smooth except for slight growth-lines and a microscopic granulation which covers the whole surface. Lutrnil areas /'>// /•"/, flat, rarely with slight radii, smooth. In the excavation at the diagonal line a lens shows a few very short longitu- dinal grooves, in some specimens. Tail valve elevated, //•//// rr///,W wnbo. Interior very light blue-green, each valve rayed with brown at the beaks. Anterior valves having 8, central valves 1, posterior valves 12 slits; teeth pectinated. Eaves short, spongy, grooved along the teeth. Sinus narrow, denticulate. 186 i III TON. < iirdle solid, closely covered with smooth, convex scales. Length 43, breadth 25 mill. ; divergence 105°. Length 38, breadth '27 mill.; divergence 100°. Length 33, breadth 24 mill.; divergence 112°. Cape of Gooy. de 1'Astrol. Zool., iii, p. 389, t. 74, f. 35-36 (1834).— KRAUSS, Die Sudafric. Moll., p. 37.— C. t'ljmltinhi SOWERBY, Charlesworth's Mag. of Nat. Hist. 1840, p. Conch. Illustr., f. 45, and var., f. 85, 86.— REEVE, Conch. Icon., t. 3, f. 18. ? C. politits SPENGLER, Skrivter af Naturhist.-Selskabet, iv, p. 89, 17l»7. A smooth, polished species, excessively variable in color and pattern. The short traces of grooves at the diagonal line are rarely visible without a lens, and are completely obsolete in many spec- imens. The smooth surface and unusual coloring are the more striking characters of the species; but the strongly raised lateral areas and the central mucro at once separate it from C. , etc. C. RUSTICUS Deshayes. PL 31, figs. 32, 33, 34. Shell ovate-oblong, depressed, the jugum rounded ; very dark green, much paler beneath. Entire surface quincuncially granulose. Central areas with no other sculpture, but at flu- iluinrr// enf n- indistinct) obsolete swelling rib*, or rather, obsolete knobs irregularly coalescing into indistinct ribs; blotched with paler. End valves similarly sculptured and blotched, beak of the tail valve in front of tin middle, the slope behind it a trifle concave. Interior: anterior valve having !», central valves 1, posterior valve 12 slits; teeth pectinated ; eaves short; sinus moderate, with about 13 teeth. < Jirdle dark olive, like the valves ; covered with very large stout scales. Leiurth '24. breadth 15, alt. 6 mill. Length L'n. bivadth l-'J mill.: divergence 1 15°. H.. Moll. K. MM., p, 89, t. ft, !'. 1 3, ( ; 1, J). C, /,'///'/«/'/"'/•« .Mr-, in Mol.iu- i li Mauri- tius, p. oIKI. This species has considerable resemblance : l>ut the lateral arca< and end valves an- le.-s Btronglj Sculptured and the longitudinal rihh-ts arc lacking on the central areas except at the diagonal lines. The above description is from Carpenter's J/>. C. ANGUSTlco>r\ n> <,Juoy iV (iaiinanl. IM. :51,fii:s. -'IT, Shell ovate, wide, little elevated, depressed hehind hy the prom- inence of the anterior valve. The third to the seventh valves are excessively narrow, arcuated hehind. with a little median projection, which contributes to form a dorsal carina. The last valve is the largest of all, nearly orbicular; the second valve is next in size, the intermediate valves being about equal. Sutural plates narrow, separated by a wide, flat, sinus ; insertion-plates denticulate. The end valves have striated teeth. The entire interior is a pretty green ; and this we suppose to be the color of the outside, but it is eroded. AVe think it is striated like our C. rtritlf*. The girdle is scaly, the scales oval. Length 22, width 16, alt. 8 mill. Lie of Fi'min; C. (niitn* Q. & G., Voy. Astrol. iii, p. 398, t. 73, f. 4, 4'. The entire substance of Quoy's description is rather freely trans- lated in the above paragraph. It is very likely that this is merely a greatly worn specimen of C.yW//xxoyyr////x Q. & G. ( '. NKiKoviiMiNS Blainville. PI. 31, figs. 41, 42 (enlarged.) Shell ovate, moderately elevated, the dorsal ridge obtuse ; black- ish. Mucro in front of the middle, little raised, the slope behind it straight. Valves obtusely beaked; entire surface minutely quincuiK-ially •rranulated; jugal area smooth, often eroded; central areas having about 30 delicate lirulse on each side, parallel to the dorsal ridge, sometimes eroded ; lateral areas moderately raised, having 6 to 8 delicate granulose riblets, the intervals Hat. Interior: anterior valve having 12, central valves 1, posterior valve 14 slits; teeth short, obtuse, coar.-ely pectinated; eaves small : sinus wide, flat, 12-toothed. Girdle covered with solid, smooth, lanre and rounded imbricating scales. Length 17'., breadth 10 mill.; divergence 117°. •/ H<>i» . 188 ( IIHON-SCLEROCIIITON. Chiton nigrovirent P>LAINVIU,E Diet. Sci. Nat. xxxvi, p. 538 (1825).— HADDON, Challenger, Polyplac., ]>. 22.— C.operMU GRAY, Spicil. Zool., p. 5 (1828). — HANLEY, in Wood, Index Test. Suppl. t. 1. f. LI.— REEVE, Conch. Icon., t. 22, f. 151.— KK.U--, Die Siidafric Moll., p. 37. C. TENUISTRIATUS Sowerby. PI. 38, figs. 27, 28. Shell oval, carinated, the back elevated ; valves all over very finely radially striated; girdle scaly. Length 25, width 15 mill. (So>r/,.j A neat little shell of a dark olive-green color, oval, elevated, nearly smooth in appearance, but finely striated ; margin lighter green than the rest of the shell; inside bluish-green. (Sotcb.) Habitat inihiiinri, (Mus. Stainforth.) C. tfimlxfrinfii* SOWB., in Mag. Nat. Hist. 1840, p. 291 ; Conch. Illustr., f. 135, 135. This is apparently a typical Chiton, closely allied to qnoyi or , but it seems to be more elevated than either. C. MAURITIANUS Quoy & Gaimard. PI. 31, figs. 39, 40. Shell small, oval, elongated, the valves elevated, carinated, trans- versely finely striated and having lateral areas over which the stria- pass. It is a very dark green, lighter at the ridge, and at the edge of the girdle, which is covered with fine, close, rounded scales, and marked with 18 brown bands. Branchial leaflets about 38 on each side. Length 18, breadth 10, alt. 6 mill. Mauritius. r. mawritianu* Q. & G., Voy. Astrol. iii, p. 397, t. 73, f. J-3.— L'j,itli,l,/, a, -ii." mini, -H'mit a* MARTENS, in Mobius' Reise nach Mauritius, p. 300. Known only by the original description, which is far from being satisfactory. The interior has not been described. It is a more carinated species than C. quoyi, and the striation is in a different direction ; the girdle also being banded with brown. Section SCLEROCHITON Carpenter, 1892. 'eroeh&m CIM:., .l/\, in Dall, Proc. U. S. Nat. Mus. 1881, p. 284, 287, 289 (no type mentioned.) Teeth of the tail valve turned forward, blunt and pectinated ; sinus smooth, not denticulate; scales of girdle solid, striated, uted. OHITOK i: LDflJ \. This section or sabgeniu represents a further development of the AcMiithoplcuroid characters which sonic A uM ralasian ,-peries of the restricted p-nus ChUmi a-.-ume. In ("//. /» ///.•»•/ ,-/» ////'-, lor example, the 'micro is median, the posterior teeth tend forward .-om»-wh;i- sinu- i- smooth or only very ohsoletcly denticulate, and the girdle- scales are striated and rather separated. I" &-i,-,'n<-hiin,i the mucro is -lightly more posterior, the teeth slightly more tilted forward ; the sinus is smooth, and the girdle scales still more separated. ('I. il* could be placed almost as well in Schrncliitnn as in 8. *. ; the necessity of reducing Sclerochiton to the rank of a section under (1liifnn will therefore be apparent. The girdle-scales hear a certain resemblance to those of En<>i>In, but this is a purely accidental similarity, dependent upon their separation on the surface of the girdle. C. MILES Carpenter, n. sp. PL 46, figs. 1, 2, 3, 4, 5' Shell solid, rugose, oval, depressed, generally eroded ; dorsal ridge rounded, hardly defined ; mucro behind the middle, nearly flat; apices of the valves prominent, obtuse. Ashen, spotted with black-brown. Central areas transversely pretty regularly riigulose, the wrinkles appressed ; lateral areas hardly elevated, moderately well denned, conspicuously rugose, rugae subradiating, granose ; the end valves similarly sculptured. Interior having the anterior valve with about 11, central 1, pos- terior valve obscurely 9-11, slits. Teeth of posterior valves directed forward, strongly callosed inside above the slits, sulcate outside ; the rest of the valves having the teeth sulcate outside and pect- inated at the margins. Eaves moderate, solid, deeply grooved. Sinus deep, wide, wavy, smooth ; sutural laminae united. Girdle (pi. 46, fig. 1.) maculated, ornamented with large, solid, more or less separated scales which are striated outside ; no hairs. (Cpr.}. Length 30, breadth 17* mill. ; divergence 130°. Tnrrr* Sf I'll iff (Mus. Cuniing, no. 42.) A variety is described as being a little narrower, and blackish, hardly maculated. Section KADSIA Gray. i;,i,l*i>i ( JIIAY, P. /. S. 1847, p. 126. Type Ch. /*/,•//- Girdle and shell like C/iiti>//, except that the insertion-plates of the intermediate valves have two or several slits. I'.il) CH3TON-RAD8IA. Carpenter's opinion of the small importance of the character upon which this Lrroiip is founded, is fully supported by the material studied by myself. lie writes as follows: "The bi- or tri-slitting of the lamina1 appears to me a character of very secondary impor- tance, as Ix-iiiLf merely numerical, not structural, and as being very variable even in the same specimen. In one specimen of Dr. Gray's type which I received from Mr. Cuming, only one r /mil fm> >•///.< »-h >/'/<; most of the other valves had one only ; sometimes a second slit was seen on one side. For such a specimen it would have been as useless to establish a genus as for C//. i'!i-i/n/ntu.«, or for C. a 1 1 in which Dr. Gray found the same abnormality (vide P. Z. S. 1847, p. 127). Another specimen of C. burnt^ii had the valves either with»one slit or with two slits on each side, or with one on one side and two or three on the other. Under these circumstances I cannot regard the number of slits as a generic character." Compare alse the notes under C. Key to species of Ji!>. Riblets fine; color variegated. c. Ribets of central areas nearly obsolete ; of lateral areas irninose, Imrin-xii. cc. Riblets of central areas fine, distinct ; shell olive mottled with dark, . C. BAI:NI>H ( iray. PL 29, figs. 10,^1, 12. Shell oval, J/y,,v.n,, ///o//x nulinfinfi /•//>.>-. Ccnfriif OfOtU .<>-ii/j,fii,-> i1nr*nl /vWy, and some- what latticed by growth-lines. Knd valves having radiating nodulous ribs; mnfm thrr . potterior valve L8-19 ilita Teeth l>lmit, pertinat. narrow, SpOB (Jirdle eovrre.1 with sliiniii-, o.nvex, minutely ,-triated scales. n't in !><>, ( '/////. ( liitnn tarn«§t» GBAY, Spirii. 7<>ol., p. r>, t. 6, f. 22. — Sown, in M..11. Beechc}- Voj., p. HH, t. 11, f. 10; Conchol. Illustr., f. 2.— REEVE, Conch, Icon., 1. 1, f. 1 ; t. 21, f. 137. Kntirely different from the other species of Radxia in form jind sculpture. The rihlets upon the central areas are very fine and their interspaces shallow. Occasionally a specimen occurs having some of the valves with a single slit one side. C. GOODALLII Broderip. PL 29, fig. 9 ; pi. 28, figs. 5-8. Shell very large, oval, moderately elevated, carinated, the side- slopes nearly straight or rather convex. Surface nearly smooth. Color blackish, olive-black or brown-black, generally showing an obscure olive-green stripe on each side of the keel.' The lateral areas are a little raised, separated by an obtuse ridge from the central areas, and in most specimens they are son/new In it. t< miri'il IHJ roiii-i'utrlr mark* of groicth-arrest. There is no other >sru/jit- ?'/•> <>n i iflii'r c> ,it,;il nr lateral areas except an extremely minute and even granulation over the whole surface. The umbo of the posterior nifr,:* !* u ii ii.rin olwe-blaehj or having the lateral areas obscurely purple-black. EUDOXOC ill I Lateral area- .//«-eit« Slmttleworth, Diagn. n. Moll., no. 4, in Bern. Mittheil. 1853, p. 65. Xo description of this species has been published. It is said to be from California. Possibly founded on a Ch. ciri/H/iitn*, q. V. Genus XIII. EXJDOXOCHITON Slmttleworth, 1853. Eudoxochiton SHUTTLW., Bern. Mittheil. hsr>3, p. C>7, type A. unhil'i* ( lUAY. — Aoiiithn/t/rnt'ii SCCt. * * f, GRAY, P. Z. S. 1*47, p. 68, n",, ( Juildin;:.— JAhort slits. Girdle leathery, setose. (iills extendini: the entire length of tin- : The valves, when eroded, are seen under the len> t«. be «lnisely. evenly and regularly punctured all over. The interior is white, and i IIM.X.H m i <•(' a dense, porcellanuu> texture. The laciniated inMltk>n*p] cut into many short teeth, combined with the haohh mile and continuous sut ural-plate>, an- the nio>t >t rikinir Lreiierir diar- acten, From A<'}>/i urn and Mau^i-rin, irroups to which Home authors have referred the type of this ircnus, Kml<,.n,rliifoi, is sundered by the lack of eyes in the valves, the multiplicity of .-lit-, dcpres-cd inucro, etc. I', sides the following, C/i. /inter (CLem.) Reeve may belong to this genus, but its generic characters are entirely unknown. See appendix. I-:. eroBiua (Jray. PL 46, figs. 88-95. Shell ohlon.ir, < /< r/oA///V ( ii; \v. in Dieffenbach's New Zealand, ii, p i 1843). — Chiton (Einlu-nrl,it,m') m>/n'li* Gray, SHUTTLW.. l>orn. Mittheil. 1*.~)3, p. 67. — Chitn,, t Ch&tcpleura) iinbili* (\\-\\\, SMITH, Zool. Erebus and Terror, p. 4, t. 1, f. 8 (1874 >.— HuTTON, Man. N. /. Moll., p. 115 (1880.) This species differs from the following in its more elongated and much more elevated contour, and in the stronger valves. The 13 I'.il TONK'IA. seventh valve is represented in figs. 89, 90; and a square millimeter of the girdle is indicated in fig. 95. K. nt ri MM Pilsbry, n. sp. PI. 46, figs. 96-100. Shell oval, j>, •<*.•<> -ides the fundamental characters above recounted, the species of this genus mostly agree in having the valves >mo7»this.h, the second valve notably larger than the following five, and often differ- ently sculptured on the ridge; the sculpture is generally fine or minute, the colors much variegated or uniform black-brown, and the ••s are hardly spongy. IVom CkcRtopleura and T pectinated insertion-plates. Tin- .u'emis ( hiil hodiihni ha~ nmilar >iii'M»t!i valve-, !»iit the posterior valve lacks slits and teeth of insertion, The specie- «>f Tnu'n'in iuhahit mainly the -hores of the southern and tropical Pacific, hcin.u; found from Middle America lo < Horn, and irom tin- Philippines to Australia and New Zealand. They may l>e grouped thus: A. Valves not immersed or separated, imbricating, section Tonicia. 1. Species of West America. 2. Species of the Wc.-t Indies. 3. Species of New /ealand, Australia, Red Sea, Philippines. B. Valves partly separated, the girdle encroaching on them at the sutures, section Fannettia. Section Tonicia s. sir. I. Species of West American shores. T. CRENULATA Sowerby. PL 45, figs. 69, 70, 71, 72. Shell oblong-ovate, slightly more narrowed in front, moderately raised, the back carinated. Ground-color buff or slightly rose- tinged, having oblique dark olive irregular stripes, often marked on some valves with rich brown ; apices of valves pink when eroded. The lateral areas are raised and well-defined, and except the pos- terior third or fourth, are studded closely with black eyes; the suture is prominently ami ro'iwly '-renulated, and there are some irregular radiating rows of granules on the back part of the areas, and some- times a row or two dividing the^eye tract. Central areas having a smooth keel in the middle, bounded on each ru/re by a V formed by two low divergent waves, crossed by convergent riblets ; pleura or sides sculptured with longitudinal-diverging rugte or ribs. Anterior valve high, with radiating rows of weak granules alternating with rays crowded with eyes. Tail valve with slightly posterior, elevated mucro. Interior white, with a large red tract in each of the median valves. Slits in anterior valve s, central 1, posterior 14; teeth obtuse and short in the posterior, acute and longer in the anterior valves, sulcate 196 "in side and at edge. Sinus square, denticulate ; sutural-plates ami in>t rtiun-plates white. Girdle leathery, thin, yellowish-green, naked. Length 34, breadth 20 mill. Length 50, breadth 33 mill. ; divergence 115°. J'enrl Island, Bay of Panama (Cuming, et al) ; Mazatlan (Reigen.) Chiton crenulatus BROD., P. Z. S. 1832, p. 27.— SOWERBY, Conch. Illustr., f. 43.— REEVE, Conch. Icon., no. 29, t'. 6, f. 39 (error for 29). "/ Tonicia" forbesii CPR., Mazatlan Catal., p. 193 (1856.) This species is readily distinguished from the other West Amer- ican forms by the greater width of the lateral bands of eyes, the crenulated sutures, and the beautiful sculpture of the central areas. The second valve is not so prominent as in most species of Tonicia, and it is sculptured like the other intermediate valves. T. ELEGANS Frembly. PL 41, figs. 22, 23, 24 ; pi. 42, figs. 31, 32, 33, 34, 35. Shell elliptical-oblong, not much elevated, the dorsal ridge rounded, side-slopes straightened. Color umber-brown at the sides, becoming chestnut in the middle, delicately and peculiarly speckled and blotched and streaked with buff or buff-white. Lateral areas hardly raised, but separated from the central areas by an obtuse diagonal ridge bearing a series of low tubercles, some- times subobsolete ; sculptural n'ith subradiating roics of small gran- ules, and showing a band of irregularly placed black eyes on the for- ward part. Central area of second valve having in the middle, a keel or a group of line ; centralareas of the other rntrrs hiring a i\«r- tnut-yellow color. Length 48, breadth '\'2 mill.; divergence 125°. Call Valparaiso. [CIA, l'»7 n ' FBXKBLY, ZooL .i<>un>. ill, p. 208, -nppl., pi. 17, f. 6. — S. >\\ r... ( 'oiich. Illuslr.. no. 75, II i.i.v i , ( ouch. Icon., t. I. f. 11). — ('. 3OWB.J Conch. IllnMr., f. 7-'), 7 \ 'young.) The type species of T"iii<-in. The scul ptu re is well shown in fi;:. 1)%J : the color-pattern in the liirure l>ct\\ccn '2'2 and lM. Subspecies cnii.i N-I- Fremhly. PI. 41, figs. 19, 20. Shell rather heavier and thicker than T. rlgr/an*, with thicker girdle. G>A>r « uniform tlnrk chocolate brown, except near the beaks n'here ff» re /.< a large or sum// arm th< *hnj>r of f/ir ra/rr n-hich is /i'/hf de/irnfe/it mnff/> tlingtinul litir /x turmounted by a wie* <>f #wnll tubercle; lateral areas showing fewer and less conspicuous eye-spots than T. el'' > th r> /•'/ thick and b/tmt, strongly, closely pectinated. Girdle leathery, naked, rather thick. Length 38, breadth 28 mill.; divergence 130°. Length 68, breadth 43 mill. Valparaiso, under stones. C. r/iit''n.«I* FREMB., Zool. Journ. iii, p. 204, suppl., pi. 17, f. 8. — REEVE, Conch. Icon., t. 3, f. 17. — Tonicia chilenxis ROCHEBRUNE, Nouv. Arch, du Mus. 1881, p. 240 (Reported from the Canaries, on the authority of specimens so labelled in the Paris Museum, but undoubtedly false.) This form is very closely allied to T. elegans, differing mainly in the (a) dissimilar coloration, (/>) more numerous stria? on each side of the median smooth band, (c) generally obsolete granulation of the lateral areas, (d) thicker insertion-teeth, and in the thicker girdle ; a still better distinction is in the tail-valve, which in rh Mentis has a more prominent umbo, nearer the center than in < /ff/ans, and the area in front of the umbo is striated, whilst in rlei/nn* it is smooth. All 198 TONKIA. of these differences however, do not avail to name specimen- in which various characters of eZ^an* are combined with other char- acters of cliilni.*!* ; so that while when typically developed the forms may readily be separated, it is, I believe, impossible to classify occasional synthetic specimens. I have therefore considered <-h if- a phase or variety of d> il-l. — KI.KVK, Conch. Icon., t. 7, f. 34. — Tmtinu Hn<>>i/afn$ CPU. — ? Chitm, bruguieri I'ot. & Mich. Galerie, i, p. 534 (1838.) The distinguishing characters of typical lineolatu." are the lack of larger tubercles along the diagonal rid-v. and the fine concentric line-painting. The characters of both sculpture and color-pattern however, are in some specimens inextricably united with these of T. elegan-, of which species I am therefore compelled to consider this a variety. Many specimens show several valve- of uniform black-brown; others are blotched on many valves with the same. The species [OTA, I'1-' somewhat resembl< '/<•<• p. H', pi. 11. (8), lull dilli-rs sufficiently in sculpture and tli- OH <>f black eye-pits, as well as in tin- entirely diilJ-mit insertion-p /'. * nihles /uii'n/tifii in color-pattern, l»nt it dilfer- entirely in having the entire central areas Inngit udinally, and the latei-il areas and end valves radially c-ostuhite. T. i AMI..IM v (.r;iv Sowe.-l.y. PI. 41, fig. 21 ; pi. 4L>, figs. 36, 37, 38, Shell oblong, moderately elevated, subcarinated ; the side-slopes nearly straight; surface sinoothisli. Color olive-brown, sometimes whitish, Inirl IK/ imli^lnd concentric dur/a r xtre'tk* ; rarely unicolored black-brown. / teral urea* hai-dlij raised, indistinctly separated from the central areas by a smooth, low or obsolete diagonal ridge. Entire surface of lateral and central areat covered with a microscopic granulation, the granules sometimes coalescing into short wrinkles in front of the diagonal at the sides. 7)o/W ridyr Imvlmj a i'cnj narrow .-•niootk band in the middle, on each *ide of whic.lt fhrre are several deeply engraved longitudinal . Z. S. ls:v_>, p. 58; Conch. 111. (assyn. of elegant), f. 18*, 10, 29, 30.— RKEVK, Conch. Icon., t. 3, f. 14. The main distinguishing characters of this species are its even fine granulation, lack of tubercles on the low diagonal ridge, few engraved grooves on each side of the smooth narrow dorsal baud, and the obscure concentrically streaked style of coloration. 200 i " M i • i A . I do not know whether the C.clnlornsis of Sowerby belongs to this species or to C. elegans. It is represented on pi. 42, fig. 40. T. GRANIFERA Sowerby. PL 43, figs. 44, 45. Shell ovate, chestnut varied with white and black; dorsum elevated ; front valve radially granose ; lateral areas and posterior area of posterior valve subradiately graniferous; central areas longitudinally granose-lineate, marginal ligament smooth. Length 25, breadth 15 mill. (&w-&.) Conception, Chili; on Mytilus in 9 fms. (Cuming.) C. graniferus SOWB., P. Z. S. 1832, p. 104 (Conch. 111., f. 8 ?).— KEEVE, Conch. Icon., t. 15, f. 86. — ToniciayraniferaGpR., MS. Evidently closely allied to T. elcf/an*, having much the same sculpture. T. GRAYI Sowerby. PI. 43, figs. 46, 47. Shell oblong, pale, varied with brown and rufous ; anterior vnlrr, lateral areas and tail valve radially granose-striate ; anterior margins of lateral areas elevated, posterior margins [xutures] crcnulated. Central areas obliquely longitudinally granulose-striate ; third to ft i-i-nth valres longitudinally bixulcate in the middle. Marginal ligament smooth. Length 30, breadth 17 \ mill. (&»/•/>.) Island of St. Lawrence, Bay of Callao, Peru, on shells in 17 fms. (Cuming.) Chiton f/raifii SOWB., P. Z. S. 1832, p. 57 ; Conch. Illustr. f. 8.— REEVE, Conch. Icon., t. 17, f. 105. — Tonicia grayi CPR., MS. This form is evidently closely allied to T. elegan*, etc. The italics of Sowerby's description translated above are my own. Carpenter thus describes the type specimens : Jugular areas with deep grooves on each side of the central smooth rib, but both grooves and rib are evanescent on the second valve. Central areas with a second set of granules parallel to the diagonal and more or less con- tinued into faint riblets, somewhat diverging from the more prom- inent apices. Lateral areas with a very decided row of rugose granulations along the diagonal, inside of which is a smooth space crowded with metallic dots [eyes] ; then two or more rows of very rough irregular granules, ending in sharply crenate sutures. End valves with about eleven obsolete riblets, irregularly Lrranosc, with rows of metallic dots between each. Mucro in front of the middle, swolk-n, but the slope behind it Anterior valve having 8 central I, po.Mrrior valve II slils; treth v«-rv .-harp, !"•<•! inat«-d Sinus Hat moderately deep and hn»ad, \\ith up to Hi teeth. Lengtli 80, hreadth 17 mill.; divei T, MKMA Sowerl.v. IM. II. ftgi, 28, I".), 30. Shell oval-oblong. smooth, sulicarinated ; valve- ncarlv sul.n»trate ; lateral areas inconspicuous; maririn ['_rmlle] smooth. Length 26, breadth 1 L'.1. mill. \o,r/,.) The smooth, narrow, .-lightly aiiLrulated species above de-rrib« of a blackish-brown color; the lateral areas an- not distinctly marked except l>y rays ot'liirhtcr color in some specimen- on them, and on the terminal valve>. (.sVw/>.) F'tlL-tnnd I*. (Sowb.) ; Ora),-20 denticle-. Hutton reports this species from Macquarie Island, X. /., but says: " Our species agrees very well with Reeve's figure, but not with hi.s description. The anterior terminal area is distantly radiately ribbed, and the lateral areas are sometimes defined by a single rib. The umbone of the posterior valve is more posterior than in the drawing, and the valves are of a uniform hrown color. The mantle is of the same color as the valves." These characters seem to me to indicate a distinct species, which may he called /'// T. SWAINSONI Sowerby. PI. 43, figs. 41, 42. 43, Shell oval, moderately or decidedly elevated, somewhat earinated. the side-slopes nearly straight. < I round-color li^ht pinki>h-l>uH'. /minted all over with n mult if ml- r rrtl-hroivn linen, < t» the beaks; often havinir some valves striped at or on each side of the ridire, or more or le>s completely covered with dark n-d-l»ro\\n. Lateral areas little raised, xo////^,>' . Beak of tail-valve obtuse, behhul il< miililfc. Inf< n'or of a jie'-u/inr r»l-/>roirn color, the callus of each valve- whitish. Siittirii/'ii/nfi.« //////, )'til-l»rnirn. Sinus delicately dentic- ulate. the area behind it, extending to the beak, transversely wrinkled. Slit< in anterior valve 8, central valves 1 . posterior valve 'I . roinci \. teeth finely crenulated oiilsidr ami at ed'je, rather thin, and colored ivd. A- in other -prrirs liavini: a po-h-rior mncro, the tail- valve teeth art- directed forward. < iirdlr yellowish, leathery, nude and smooth. Length L'*, luvadth 1 :» mill.; divergence 108°. Callao ; and Chili (U. S. 1 This species differs from all of the T. vtcgans group in lacking sculpture upon the central areas and engraved grooves along tin- dorsal ridge; and from other species of Toniria in the red sutural- platcs. teeth, etc. The blunt inucro is posterior, and the teeth in the tail-valve are directed forward. The posterior margin of the tail valve is broadly waved upward in the middle, as in Eudoxochiton. T. HORNIANA Rochebrune. PL 43, figs. 50, 51. Shell ovate-elliptical, carinated, rufous, marbled with buff and roseate ; anterior valve radially costate, posterior valve small ; inter- mediate valves having the central areas minutely concentrically striated; lateral areas multi-sulcate and ornamented with two lines of dots. Marginal ligament dull roseate. Length 19, breadth 14 mill. (Eochebr.') Orange Bay, Patagonia. T. horniana ROCHEBR., Polyplac. Cap Horn, p. 139, t. 9. f. 7. T. M ARTIELI Rochebrune. PL 43, figs. 48, 49. Shell ovate-elongate, strongly carinated, the ends of the valves curved backward, brown-rose, anterior valve radially strongly costate ; posterior valve small ; intermediate valves having the central areas transversely lineated, lines denticulate; lateral areas granulated and margined by asquamate hand. Marginal ligament violaceous-rufescent. Length 21, breadth 14 mill. Strait* <>f Miiyltitn. T.martieli ROCIIKHK., Polyplac. Cap Horn, p. i:J!», t. 9, f. 8 (1889.) T. LI.HKUNI Rochebrune. PL 43, figs. 52, 53. Shell ovate-elliptical, carinated, shining, violaceous or greenish- roseate. End valves radially most minutely striated; intermediate valves having the lateral areas covered with tubercles ; the central areas concentrically silicate, the sulci wavy; marginal ligament narrow, leathery, whitish- violaceous. Length 29, breadth 12 mill. (AV//e6r.) Punta Arenas, 0 ran y /: . >';. /•/' .1A/;// //»//». •J'»J -I CIA. Touiria lebnnii ROCH., Bull. Soc. Philomath. Paris, 1883-'84, p. 35 ; Polyplac. Cap Horn, p. 138, t. 9, f. 6. T. FONTAINKI Rochebrune. Unfigttred. Shell ovate, broad, subcarinated, gray, with brown spots. Ante- rior valve, lateral areas of intermediate valves, and posterior part of posterior valve very delicately striatulate and sparsely covered with conic tubercles ; central areas sculptured with beaded longitudinal waved lines. Marginal ligament rather wide, leathery, rufous. Length 11, breadth 9 mill. (Rochebr.} Chili (M. Fontaine) ; Paris Museum. Tonicia fontainei ROCHEBR., Bull. Soc. Philom. de Paris, 1881- 1882, p. 193. The foregoing species are not defined with sufficient exactness to insure their indentification, Rochebrune being a century behind the times in descriptive zoology. T. ARGYROSTICTA Philippi. Unfigured. Girdle smooth. Valves smooth, subcarinated ; lateral areas hav- ing a single series of distinct silvery impressed dots. Length 4J, breadth 3 lines. This small species is sufficiently distinguished by the peculiar impressed silvery -shining points, which remind one of the similar marking on some Carabidse. On both end valves they stand in several concentric rows. The coloring varies ; the brown-red color predominating; in one example there are whitish flecks and trans- verse stripes, in another longitudinal stripes. (Phil.') Strait* <>f Muyellun. Chiton argyrostictus PHIL., Archiv fur Naturg. 1845, p. 59. T /.SCHAUI Pfeffer. PI. 40, fig. 12. The animal is much elongated, the breadth hardly one-half the length. The inner region of the girdle is covered with very minute granules, hardly visible under a strong lens, arranged in not entirely regular oblique series, and separated by about their own dimensions. Under a low-power lens the girdle appears. quite naked. Toward the margin these granules grow into transparent, short spines. The 28 branchiu.' roach the entire length of the foot. The valves are quite shining, and sculptured with close growth- stria? ; otherwise they appear smooth under a \\vak power of the lens; under strong magnification a fine granulation is \i>il>lr. The median valves have only a low angle separatini: central and lateral 01 v. arras; the growth wrinkles, which mi the lateral U and prominent, are Weaker OD the central areas, the posterior part of which appear sculptureless. The iimho seem.- to \v produced hack- ward [heakedj in young shells, hut in this specimen it is so upon the I'd valve only. The dorsal ridge is bluntly angular. The head valve is long compared with its hreadth, the length of the front slope equalling tliat of each of the posterior margins ; it shows weak concentric sculpturing of stria?. Tlie tail-valve is small and narrow, not much more than two-thirds as broad as the head valve, and also notably shorter; its forward area is not shining; the posterior segment is shining and sculptured like the head valve. The lateral areas and the outer anterior parts of the central areas are yellowish-red with red marbling. The central area shows on its middle part, a group of beautiful chocolate-brown and violet- white stria?, radially diverging from the umbo. On the anterior median valves are seen also a few clear brown streaks on the outer part of the central areas. The single specimen before me is fastened on pasteboard, and measures 13'5 by 6 mill.; the broadest valve is 5 mill., so that the girdle is but *5 mill., wide. The third median valve of this specimen is abnormal in being pure white. South Georgia. Chiton zschaui PFFR. in Moll. Siid-Georgien, Jahrb. Hamb. Wissensch. Anstalten iii, p. 105, t. 3, f. 2 (1886.) This is placed in Tonicia with much doubt, for the presence of eyes is not noted in Pfeffer's description, above. T. TEHUELCHUS d'Orbigny. PI. 40, figs. 13, 14, 15. Shell oblong, elevated, strongly carinated ; brown with two white longitudinal zones ; head-valve and lateral areas radially sulcate- bifurcate; central areas longitudinally punctate-silicate. Length 27 mill. (Orb.) Jj, figs. r>4, 55, 56. Shell oblong, moderately elevated, roundly angular. Surface polished. Qround-eolor l>uj)\ mnitltr sometime* 206 i CIA. with bright rtddith-brown. Valves strongly beaked, the umbo of the far to the posterior (fig. 54). Central area* smooth throughout; lab ml areas separated from the central by a prom- inent, rounded, curved diagonal rib, and #mo<»th except for a broad band of black eye dots, variously arranged, on the forward half; suture* feebly or obsoUfaly crenulated. Head-valve smooth except for 8-10 broad rays of eye-spots. Interior white, stained with crimson along the jugal tract. Sinus obsoletely denticulate. Anterior valve having 9-10, central valves 1, posterior valve 14 slits; teeth deeply and regularly pectinated on outer face and edge. Posterior border of each valve in flexed and maculated with reddish. Girdle leathery, tawny, flesh-colored. Guadalupe ; Florida Keys ; Bermuda, Chiton (Tonicia) Mchrammi SHUTTLW., Journ. de Conchyl. 1856, p. 171, t. 6, f. 9. — T. schrammi HEILPRIN, The Bermuda Is., p. 176. BALL, Catal. Moll. S. E. U. S., p. 174. This form differs markedly from those of Western South Amer- ica in the non-sculptured central areas, prominent diagonal rib (like that of T. cremilata), and broad bands of eye-spots. The umbo of the tail-valve is far backward, and in most specimens the posterior margin of the same valve is distinctly emarginate in the middle, the teeth being much shorter there and irregular. In this it resembles Eudoxochiton. The diagonal rib is more prominent, and the eyes far more numerous than in T. rubridens. The nearest ally of schrammi is the very differently sculptured T. crenulatn.*. 3. Specie* of Australia, New Zealand, Philijui'me*, etc., etc. T. 8UEZEN8I8 Reeve. PI. 40, figs. 16, 17. Shell oblong ovate, valves very closely concentrically wrinkled at the sides, with oblique wrinkles toward the middle; yellowish, delicately stained with pale scarlet and green ; ligament horny. (Reeve.) f of Suez. C. suezensis K i i \ i , Touch. Icon., t. 20, f. l.".-4 (May, 1847 ,— !>.-] i. Moll. Mar Ross., . p. 235.— COOK i:, Ann. Ma-. N. H. 1386, j». 276.— ' S \vh.sx. | ),.>cr. Aegypte, t. 3, f. 4. — Tonieia f suezensis (Vi:.. MS. Carpenter writes: Mucro subposterior-median, rectangularly elevated. Interior: anterior valve having 8, central 1, posterior valve 13 slits; posterior teeth shorter, bending forward, anterior [( I \. sharp. i , v« -ry deeply pectinated. I ... tdl -inns minutely denticulated. This species :nnl the following, with trniH'iitn. are intermediate between Tnnirin and .\r,it,ffi»/>/>'ii,-'i ; hut they a-Tee with this ireiius in the porcellanoiis texture, deep slits, angular denticulated -inus and pect inated teeth. Tin- .-li-ht la: lion of the girdle appears to l>e a secondary character. T. NIGBOFUN4 r\i \ ( 'arpenter. Unfigured. sholl small, rather elongated, elegantly clouded olivaceous and l>ro\vn ; moderate] v arched, the dorsal ridge obtuse. Lateral areas moderately defined, ornamented with radiating and longitudinal wrinkles irregularly decussating, with black dots scattered between them. Central areas having subparallel, subdecussating, scarcely regular ribs, obsolete at the jugum. Mucro posterior, elevated. Interior having 8-10 slits in the anterior, 1 in the central, 12-14 in the posterior valve ; teeth in the posterior valve solid, sloping, short ; sinus broad, denticulate. Girdle copiously clothed with hair- like scales. Length 12, breadth 6'2, alt. 1-7 mill. (Qpr.) Tahiti. (Pease.) Acanthopleura nigropunctata CPU., P. Z. S. 1865, p. 511. — PEASE, Amer. Journ. Conch, vii, p. 194. — Tonicia nigropunctata CPR., J/\ This species is most closely allied to T. suezensis, but the latter has the valves more beaked and curved, and the central rugae per- pendicular to the diagonal lines, while in this they are nearly parallel to the dorsal ridge. T. FORTILIRATA Reeve. PI. 40, figs. 3, 4 (enlarged.) Shell ovate ; valves somewhat beaked in the middle ; posterior valve umbonated, blunt ; lateral areas rather concave, granulated anteriorly ; central areas strongly arcuately ridged. Yellowish variegated with green, stained with red in the middle. Ligament horny. (Reeve.) Rait if* f-^'ind, Torres Sts. (Ince) ; Port Darwin, 8-10 fms. sand and mud ( '( !oppioger.) Chiton fortilinihi* KVK., Conch. Icon., t. 18, f. 112.— C. (ZWcm) fortiliratus SMITH, Zool, ' Alert ' p. 84. ( 'arpenter writes of the type: Anterior valve having «>, central valves 1, posterior valve 13 slits; teeth short, numerous, very sharply pectinate: short at the hinder end but gradually becoming a little longer. Kaves short, slightly rugose, not spongy ; sinus with about 20 teeth, rather broad, flat. Interior whitish. Outside ashy 2<»S TONICIA. >usly pencilled and marked with olivaceous; beaks small, con- spicuous. Jugal area very small, smooth in front. Central areas with :il»out 20 smooth riblets, curving toward the middle on the median part of the areas, and toward the outside of the areas radiat- ing outward. Lateral areas scarcely raised, having faint rows of granules; at diagonal rib and at sutures having slight elongated granules toward the sutural ribs and rows of metallic dots next the diagonal ribs. Anterior valves with granules and irregular rows of metallic dots alternating; crenate at suture. Posterior valve with median, raised, swollen mucro ; posterior slope straight. Length 28, breadth 18 mill. The single specimen collected by Coppinger is thus described by Smith : It is of a greyish-pink color, copiously blotched with black along the sides of some of the valves. The headplate •* -:•:- insertion edge is much thickened, coarsely striated externally, and is divided by 8 short narrow slits. The exterior surface is coarsely subsquamately granulated throughout, and exhibits numerous black raised dots, disposed in rather irregular radiating series. The second valve is long in comparison with those which follow, feebly peaked behind ; the fourth, fifth and sixth plates are about equal in size and a trifle broader than the third and seventh. All the inter- mediate valves are very coarsely ridged and sulcated on the central areas, and coarsely grained and minutely black-dotted on the sides (lateral areas). The ridges are flat-topped, clean-cut, nearly smooth, attenuated posteriorly, wavy, converge on each side toward the front, and the intervening grooves are feebly punctate. All have the hinder margin nearly straight and but feebly pointed at the poste- rior apex. * •* •* The posterior valve is strong and thick, obtusely mucronated in the center, very coarsely striated and serrated upon the thickened insertion-margin, which is subdivided by about 10 dis- tinct notches. The interior of the valve is liirht livid bluish, with a reddish stain along the middle of all, with the exception of the last. The mantle, as described by Reeve, is simply "horny." Length, without girdle, 18, diam., of fifth valve 9 mill. Reeve's type is a larger >peeimen. lieinir -4 mill, long, 13 wide, without girdle. I - \i:ri.vn:i:i Aiiiras. IM. 40, ficr. 7. Shell ovate, elevately convex. carinat< d. :i>hy white, ornamented at the hinder edges of the valves with pale spots, the spaces between which are very dark olive, melting into ei»nfu>rd hands of a paler hue which extend nearly across the valves; valves rostrate, undul- K'MCIA. ately concentrically -iil>inil>ricately sculptured throughout: the lateral aiva- not raised luit separated from tin- dorsal areas by an elevated ril>. Posterior valve strongly gibbous, the umbo almost terminal; mantle margin hrown. Length 9 lines. (Angas.) Port Jackson, Au-r.) T. LAMELLOSA Quoy & Gaimard. PI. 40, figs. 8, 9, 10, 11. Shell small, oval-elongate, subelevated, carinated ; valves trans- versely scaly-striated, variegated with gray or ferruginous ; girdle thick, smooth, reddish marked with radiating brown lines. Anterior valve having 10 crenulated teeth, posterior 9, and a much project- ing tuberosity. Color of valves grayish-yellow, varied with brown, red or greenish. Girdle usually yellow. (Q. & (•?.) Length 15, breadth about 8, alt. 5 lines. Tnnfja Tabu. Chiton lamellosw Q. & G., Zool. Astrol. iii, p. 386, t. 74, f. 29-32. This species has the mucro more posterior than any of the preced- ing species. 14 TONK'IA. T. CONFOSSA Gould. PI. 57, figs. 33-36. Shell oblong, solid, elevated, the side-slopes straight, dorsal ridge <-;uinated. Ashy white, delicately maculated with various shades of reddi-h and purple-brown, the darker color irregularly tessellating the posterior margin of each valve. The median valves are moderately beaked ; the lateral areas a little raised, and posteriorly and on the diagonal are very peculia rly sculptured with transverse narrow leni_r:itnl in front. p]aves narrow; sinus dentic- ulate. N i ii' .1-1.1.1 i: \. Girdle smooth, broad, ^xteDding lictwrni tin- valv<-s, and \vln-n living marldrd with vivid n-d, ^ivm and blur. Length 62, breadth .",7 mill. Valparaiso, f'lu'fi. Chiton <{(.<>]. .Journ. iii, p. 203, suppl. pi. 17, f. 5 (hrtwrrii Oct., 182<> and May, 1827).— I: < onch. Icon. t. 4, f. 21.— GOULD, U. S. Kxpl. 'Kxped., Moll, and Sh., p. 329.— Fannyia •' dispuncta " [err. typog.] GRAY, Guide, p. 185. — Fannia iliyunrta Cl'R., MS. " The transitions between this species and the normal Tonicice are so gradual, that it scarcely seems entitled to generic rank. The valves are not much more covered than in T. truncata; but instead of the lateral sinuses being angular, they are gradually rounded, and extended to the apices of the valves. The principal peculiarity is in the flattening of the mucro ; the creature, having devoted itself to lateral expansion, had no need to push its tail up into a hump. The slits are as short as if the valves were fully exposed, only extend- ing up one-third of the teeth in the anterior valve and one-half in the others. Inside, however, the gums rise to the level of the slits, so that, when seen from within, the shell appears perfectly normal. According to Gould, E. E. Moll, p. 329, the girdle is "distinctly cleft " behind. This is duly represented in the Atlas, f. 417. I have not, however, been able to trace it in either of the specimens examined. That in Dr. Gould's own cabinet, although in good con- dition, shows no trace of it. Neither Frembly nor Gray allude to it. Genus XV. ACANTHOPLEURA Guilding. Acanthopleura GUILD., Zool. Journ. v, p. 28 (in part), -f Core- phium GRAY, Maugeria GRAY, Francisia CPR. Valves exposed, beaked, generally lusterless or eroded ; provided with eyes on the forward part of the lateral areas and the end valves ; mucro posterior ; interior colored, the tegmentum broadly inflexed at the posterior margin of each valve. Insertion -plates all conspicuously pectinated outside, and directed forward. Girdle thick, covered with small or large calcareous spines. History of the name Acanthopleura. — Under Acanthopleura, Guilding defined seven sections, naming a representative of each. His scheme is here reproduced, the modern equivalents of the species named being added in brackets: 214 ACANTHOPLEURA. * Zona spinosa. Chiton yuwsua Sow., Gen. f. 1. \=Acantkopleura spinosa Brug.] * * Zona spinulosa. Ch. tarmvokaefa Gray, Spicil. [==Plaxiphora.] * * * Zona granulosa. Ch. asellus Lowe, Zool. Journ. [=Lep\doplewru*i p. 13.] * * * * Zona rugoso-granulosa. Ch. asselloides Lowe. [= Trachydermon albus L., p. 70.] ***** Zona crinita. Ch. crinitus Wood, Index. \=Acan- thochites.~] ****** Zona villosa. Ch. peruvianus Frembly. \=Ch«fn- jileura, p. 28.] ******* Zona farinosa. Ch. cinereus Lowe. \==Traehyder- mon, p. 68.] As neither of these sections were selected by Guilding as the typical group, we are obliged to select a type for ourselves ; and of course the choice must be limited to the species actually enumerated by name in Guild ing's *cheme of sections. We must first exclude such species as are already provided with generic names ; and glancing down the list we therefore, eliminate section * * *, which falls into Risso's earlier genus Lepidopleurus, and section *****, which belongs to Acanthochites Risso. Of the five sections remaining, * * was separated by Gray in 1847 under the name Plaxiphora. Section ****** was denominated Chcetopleura by Shuttleworth in 1853 ; and for the species included in sections * * * * and * * * * * * *, Carpenter established the genus Trachydermon, in 1863. These successive dismemberments have left only ihefirtft tectitm of Guild- ing's arrangement, to represent the original genus ; and Chiton spinoms, therefore, becomes the type of Acanthopleura Guilding. Unfortunately for science, few authors have arrived at this result; but the fact that it rests upon principles "t nomenclature from which there is no appeal, will, it is believed, be evident to all. Since Guilding's publication of the name, it has been considered by the following systematists : 1840. SWAINSON defines the genus (which he calls " Canth«}>]< MTti«m~ : f A. nnbi/iit (I ray. [—EudoXOCMtOH.'] ft A.pioia Sow., *i>in ii/ci-'i S>\v., MMfiti Gray, j^xosa Brug., /;/•/ S I'jti'ifirn ( I ray. [ ,!/'/"'/'/•/'/.] ftt A. f git/"* (imel. [=Dwi0p four] ; A. f trum-titn. [=2W- toio.] Neitlicr of these sections is selected by Gray as typical ; but in his " List of the Genera of Recent Mollusca, their synonyma and types " P. Z. 8. 1847, he gives on p. 168, no. 413, " Acanthopkura (iuild. 1835; Gray, 1847. Canthapleura Swains., 1840. Ch. 8pin< It appears then that not only Swainson, but Gray himself selects C. yi nn*u * as the type species. 1853. SHUTTI, i:\voiiTir, in a most scholarly essay, divided Gray's Acautho/ilenra of 1847 into three sections: Chcetopleura [equivalent to Gray's sect. * and part of f t t> and including C. rugosu* (Gray) Sowb., per n vi[> ura sect, f t plus Corephium, with some other miscellaneous species]. In 1856, GRAY again made a cruel onslaught upon the genus; and here he restricts Acanthopleura to the sect. * of his 1847 arrangement, ignoring the fact that Shuttleworth had meantime given a new name, Chceto})leura, to that section, and apparently forgetting that he had himself said in a former paper that C. spinosus was the type of Acanthopleura ! In the same paper, he proposes a new genus, Minnjrriit, for the following species, which he arranges in two sections: f> M- nobilis {_= Eudoxochiton Shuttl. 1853]. ft* ^[. /n'rc'i Sow., ,*/>! a iyera Sow., oiven.ii, a/nnosa Sow., brevispinota Sow., magnified Sow., C. 111., f. 52. He also retains his genus Core- phium for C echinatum Sow., 111., f. 47. 1858. Messrs Adams, in their Genera, reunite Acanthopleura and Coreplu'inn, with a choice assortment of other forms, under the genus " Chiton /,in turns." As the status of this generic name has been fully discussed by me on p. lf)0, comment here would be super- fluous. 1873-1882. Carpenter, in his MS. arrangement of Chiton* (an abstract of which was published by Dall, Proc. U. S. Nat. Mus. 1881, p. 284, 287), proposes to retain the name Acantkoplevra for the group of Ch. piceus; Corephium for C. echinatus ; and T7/'/ Cpr., ?ioi'., for Ch. spinosus. This arrangement is not acceptable 216 ACANTHOPLEURA. because (1) Ch. piceus is not mentioned in Guilding's essay, and therefore cannot be the type of his genus. We are not concerned with the shadows of species dimly visible upon Guilding's pages, but with the species actually enumerated by him, with name and refer- ence. (2). Franciaia being founded upon the type of Guilding's Acanthopleura, falls as a synonym. The eyes, in this genus, are generally obliterated by erosion except at the edges of the valves, but they are present in young Individuals, as in Tonicia. They are smaller than in Tonicia, and more numerous. In Mesotomura they are excessively numerous, minute and oval. In Acanthof)leura spiniger they are larger, cir- cular, and scattered around the bases of the tubercles on the lateral areas. In Maugeria granulata they are more numerous and more scattered. The interior layer of the valves is very solid and dense, as in JSudoxochiton and Tonicia, even the jugal tract inside and the slit- rays lacking punctures. The tegmentum is deeply grooved over the teeth and sutural-plates. Although but few well- differentiated species of A canthopleura are known, the range of individual and local variation is great, and con- sequently an extensive literature has arisen, and the synonymy of the species is exceptionally involved. It is not improbable that some other valid species exist, but if so, they have not yet been recognizably defined. The group Lucia Gld. (Lucilina Dall) has been considered a sub- genus of Acanthopleura, but it proves to be a synonym of Tonicia. The genus Acanthopleura differs from Tonicia mainly in the duller and sculptured valves, having the tegmentum more broadly inflexed over the posterior margins ; in the more numerous, smaller eyes, the fleshy girdle clothed with large or small calcareous spines, etc. It is not especially allied to any other genus, but some species of Liolophura, a genus near Onithochiton, are externally very similar to species of the subgenus M. Interior of valves blue-white, with a black tract behind the white-edged sinus; exterior black with a light stripe on each side of the dorsum, sides granulated ; girdle black, A. borb» Subgeuus MESOTOMURA Pilsbry, 1893. Me*otomura PILS., in the Nautilus vi, p. 105 (Jan., 1893). — Core- ]>hinm GRAY, P. Z. S. 1847, p. 65, 68.— Not Corephium BROWN, 111. Conch. G. B. edit. I, 1827. Acanthopleura : Valves transversely engraved inside, and having the sinus denticulate ; tail valve having a long, continuous insertion- plate, slit only in the middle. Girdle beset with spike-like spines. A monotypic subgenus related to typical Acanthopleura. It is remarkable for the stout spines of the girdle, the long, continuous insertion-plate of the tail valve, and the finely engraved interior. In the last character it can only be compared with Enoplochiton /.-t with strong spike-like ipL Lrill- rxtrml the whole length (.ftlir f'"<>t. ih mo, luvadth .v> mill.: divergence 1 1.")°-1200. Length 68, i.n-a.lth 40 mill. J'.ivt.i, /V/-// , Dr. \V. B.Jones); <;* (P. Ac. Coll.) : Val- parai.«>, Chili ( Fivmbly.) Chiton whiiKitu* BARNES, Amer. Journ. Science and Arts, (Silli- many) vii, p. 71, t. "», f. 4«, 4b. (1823).— SOWERBY, Conch, rilu.-tr., f. 47 (young). — GMton tvberculiferui SOWKKKY, ('at. Tankerv., p. 29, no. 688 (1825).— Chiton ./'// //r/-//x FREMBLY, Zool. Journ. iii, p. 196, Suppl., pi. 16, f. 1 (1827).— Chiton aculeatu* REEVE, Conch. Icon., t. 9, f. 49. Not C. aculeatn* of DESK, et al., nor of Linn. — Chiton (Corephiwn) spinifents Frembl., STEARNS, Proc. U. S. Nat. Mus. xiv, 1891, p. 334. This large, spiney species is not likely to be confused with any other, being very distinct in external features as well as in the peculiar insertion-plate of the tail-valve, the engraving of the inte- rior (reminding one of Enoplocliiton niyer and Chiton granosus), and the denticulate sinus. The girdle spines are frequently encrusted with a white calcareous deposit, converting them into globular pellets. The young shell also lacks slits in the posterior insertion- plate (figs. 15-17, x 2) ; and the adults sometimes show an addi- tional shallow notch or two near the median caudal slit. Subgenus ACANTHOPLEURA, 5. sir. Acanthopleura GUILDING, I. c. (part), and PILSBRY, The Nauti- lus vi, p. 105, Jan. 2, 1893. — Frantisia CARPENTER in DALL, Proc. U. S. Nat. Mus. 1881, p. 284, 289, 290 (1882.) Acanthopleura: Tail valve having a long, many-slit insertion- plate, crenulated outside ; median valves much wider across the sutural-plates (or articulamentum) thau across the exposed portion (tegmentum.) The facts which cause me to consider this the typical group of Acanthopleura have been discussed above. The affinities of the sub- genus are with Mnuyerin and with Mesotomnra. With the latter it agrees in the coarsely spiney girdle, interior coloring, denticulate sinus and long insertion-plates; but it differs from that group in having a many-slit tail-plate, in the frequent (or usual) plurality of side-slits, the nearly smooth exterior, etc. In the form and dentic- 220 ACANTHOPLEURA. ulation of the valves, and in interior coloring, A. spinosa is very closely allied to A. -•/>/»/;/< r Sowb., from which the occasional radsi- oid slitting, and the feeble denticulation of the sinus in the second valve, separate it specifically. Dr. Carpenter's subgenus Frandsia included A. spinosa only. A. SPINOSA Bruguiere. PI. 45, figs. 80-87. Shell oblong, depressed, smoothish and black ; girdle wide, covered with long, brittle black spines. The valves are smooth except for growth-lines on central areas and some inconspicuous radial wrinkling or obscure granulation on the vt'ry feebly defined, small, lateral areas. End valves somewhat rugose-granose radially, the mucro posterior. bmdepwrpl+redJnthe middle, white on the sutural-plates and the region of the lateral slit-rays. Sinus of second valve cut into delicate square denticles by short linear slits, but in the other valves the denticulation is obsolete. Slits in anterior valve 15, central valves 1 or 2, posterior valve 10 ; teeth of end-valves long, grooved outside and crenulated at the edges, the posterior teeth vertical ; teeth of intermediate valves triangular, the posterior tooth, when present, very small. Sutural plates long, separated by a deep sinus broader than the plates. Girdle wide, rusty, beset with long brittle black spines (fig. 86.) Length 50, breadth 28 mill. Albany Island, £ape York, North Australia (Challenger.) Chiton *pinn*u8 BRUGUIERE, Journal d'Histoire Naturelle, i, p. 25, t. 2, f. 1, 2 (1792).— LAMARCK, An. s. Vert, vi, p. 321 (1819). — SOWI-:I:I;Y. < ieuera of Shells, Cephala, Chiton, f. 1 ; and Conch. Illustr. p. 1, f. 151.— REEVE, Conch. Syst. ii, p. 12, t. 134, f. 151 ; and Conch. Icon., t. 9, f. 51. — Framisia spinosa CARPENTER MS. — Mn <«jlits are really very short, but are continued on the outside as grooves, up to the eaves. The eyes appear as minute amber colored heads, sparsely scattered down the forward half of the lateral areas, but scarce ly arranged in rows. Poorly preserved or very old specimens show their pits only. \< \M n»ri.i.ri: \. •_>•_' 1 Nutta/linn . ;i -li-lit resemblance to thin species, but it is diMeivnt.ly sculptured, has smooth teetli and los -piny girdle. The tail plate of A. spinosa is like that of Kntli'ii-um /»,//- icata, on account of the long, vertical teeth. A. SPINIGER Sowerby. PL 48. Shell oblong-oval, moderately elevated or depressed, lusterless, microscopically granulated an7">, f. 1692. — Chiton aculeatus SPENGLER, Naturhist. Selskabet, iv, p. 78. — Chiton aculeatus QUOY & GAIMARD, Voy. de 1' Astrolabe, Zool. iii, p. 373 ; atlas, t. 74, f. 1-5 (1834). v PHOPLEURA, 3OWB., M n. Hist. 1*40, p. 287, Suppl. ])1. xvi, f. 2; I'. /.'>. 1841, p. 61; Conch. Illustr., f. 68.— REEVE, Condi. .1. 14, 1'. 7-"). — Mnii^f'-ri'i ,*j,ini'j'ra GRAY, Guide Moll. B. M., ]). 184 (1857). — Ac.itnthojJi ">-. 80. — Chiton (Acanthopleura) spiniger SMITH, Zool. Coll. H. M. S. ' Alert/ p. 81 (1884) ; P. Z. S. 189J , p. -Awmthtif,/, urn *i>ini/">• of Lin IK' ; but any one who will consult the original description, " C. testa octovalvi striata, corjtore su bactdeato" then turn to Riimphius' figure cited as an illustration, will be prepared to acquiesce in Hanley's suggestion (Ipsa Linn. Conch.) that the '•s be dropped us unidentifiable. Gmelin had no better informa- tion upon this species than we; and therefore his additional citations jures are valueless. The mere fact that the figure cited by Limn' represents an oriental species is offset by the absolute impos- sibility of knowing that it was an Acanthoineura. Besides the localities given above, this species has been reported from Sue/, by Is>el (Mai. Mar Rosso p. 235, and see also Cooke, Ann. Ma-. N. II. 1885, p. 276), from Aden by Haddon (Challenger Polyplar., j>. 24). It has been figured from the Red Sea by Savigny (see pi. •">, ii.ur>. 4, 1-2 of his folio). Probably Savii_rny's \\^. 7, 1-3 of the same plate represent a young shell of the same, although I havr sri-n none closely corresponding in sculpture. The eyc> arc distinctly drawn by the artist, a rather remarkable circumstance when we remember that no subsequent illustrations of Chitons show them ! Additional localities are Si n- /r«Iimplilicd l»y the elimination of i'l) A. f>or/>o, ,!,;/, characteri/ed by a •ail-valv- and (2; the " Aninth- ACAM HMI-I.I i i:\. ; Au-tralia and the so-called Acant lioplmras of .Japan, which arc characterized i>y a flat ere-centie callu- in pla<-»- of the teeth in ilic tail-valve (pi. .~>3, fiir. -V Tin; variation ot'thi- Speciei is irr«-at, and a number of Hiibspeeilie or varietal forms will probably be distinguished eventually. My material is not extensive enough to permit me to diagnose these, or to indicate their areas of distribution ; and I therefore offer below the original descriptions of the several described forms. Typical >IMM»;I:I: is characterized by the possession of longer spines than any of the other forms. It is thus described by Sower by : C. spiniger Sowb. (pi. 48, fig. 22). Shell depressed, ovate-elong- ated, all over granulated ; valves reclining, ends rounded ; girdle wide, furnished with numerous subarcuate spines. .Length 2'1, width 1'5 inch. Habitat ? Mus. Stainforth. Another spini- ferous species, rather narrow in proportion to its length ; depressed and finely granulated ; the valves are rounded at the lateral extrem- ities, with their apices leaning backward, and their lateral areas scarcely distinguished ; numerous slightly curved spines, nearly one- half an inch long, cover the margin ; general color like a faded leaf, with dark patches of reddish-brown covering the lateral and part of the central areas of some of the valves, and a dark dorsal band bordered by bright green and white (Sowb. in Mag. Nat. Hist.) The fig. 22 is a copy of the original one published in Mag. Nat. Hist., and fig. 23 of that in the Conchological Illustrations, which probably represents the same specimen. Note the length of the girdle-spines. Reeve's figure (pi. 48, fig. 27) represents a larger specimen, collected by Cuming in the Philippines. In this the spines are much shorter. Figs. 24-26, pi. 48, represent valves from a specimen very similar in all respects to Reeve's figure (see pi. 48, fig. 27). The granulation is rather obscure, or transformed into low wrinkles. The spines on the very wide girdle are both long and short (1-1 \ mill.) Figs. 31, 32, pi. 48, are drawn from a specimen from the Viti I>. collected by Andrew Garrett. In this specimen the dorsal ridge has a blackish-green band with a wider fleshy-white triangle on each side of it, and a streak of green, the rest of the surface of the valves being black except the large ashy-eroded patch on each side of the black (eroded) beaks. The central areas have some scattered gran- 224 ACANTHOPLEURA. ules on the light bands, and toward the diagonal lines ; the lateral areas have rather coarse, irregular granules. The girdle is covered with alternate black and whitish patches of spines, theee being all curved like a Dentalium, rather blunt, the longer of them measuring about 2i mill, in length. Another specimen, from New Caledonia, is similar, but has no white patches on the girdle, the spines being 3-3£ mill, long, and black, often tipped with light color. The C. macgillivrayi Ad. (P. Z. S. 1855, p. 120) seems to be very similar, to this variety, if not identical ; the original description follows : C. macgillivrayi A. Ad. Shell oblong-oval, a little elevated ; black, the central areas painted with two pale longitudinal stripes; valves obtuse, under a lens seen to be most minutely granulated, ornamented with concentric undulating rugose-grained line ; ter- minal valve umbonated in front, umbo rather smooth, slightly pro- duced; girdle set with black, curved, slightly obtuse calcareous spines. Feejee Islands, on the reefs ( J. Macgillivray). This is a well-marked and handsome species, rather more than two inches in length ; the surface of the valves is finely granulated and orna- mented besides with subgranulated, wavy, concentric elevated lines ; the central areas have a pale greenish band on each side of the umbo. (Ad.) Carpenter gives the following notes upon the types : Four spec- imens, with A. Adams' autograph label. Bristles rather long for the group, crowded and curved, black, but often tipped with light as in brevispinosa. Sculpture with granules like borbonica in the young, but soon changing to concentric wrinkles. Mucro prominent, somewhat antemedian, the posterior slope convex. Jugal area granose ; in one specimen only are there white streaks making V's on the valves. Sculpture of central areas gradually changing from grains into wrinkles toward the diagonals. Lateral areas scarcely distinguished ; concentric wrinkles predominating. On the terminal valves the sculpture is much finer, the rugulte breaking up into grains. Inside color dark. The divergence is very variable, one specimen being quite elevated, the others flatter; measuring 103°, 126°, 114°, 129°. The >irit-eas REEVE, Conch. Icon., t. 13, f. 70, March, 1847. — \8, P. Z. S. 1867, p. 223.— TAPPARONE-CANEFRI, Zool. Viag. Magenta, Malacologia, p. 77 (1874). — C. obesus SHUTT., Bern. Mittheil. 1853, pp. 67," 79. Angas says that this species is freely distributed on most parts of the coast of New South Wales. The specimen commented upon by Canefri was collected at Sydney ; but both may be founded upon wrong identifications. Carpenter writes of the types as follows: "Four specimens from Australia. The figure of Reeve is much larger than the type, and would stand well for a perfect The largest shell measures: length 77 J, breadth 49 mill., divergence 108°. This is a more raised shell than cuttning- hniiii, probably from its having grown in rougher water. Spines very short, black, sometimes white. Sculpture almost entirely worn away in all the specimens ; when seen it consists chiefly of concentric wrinkle.-: more or less broken into granules. The lateral areas are scarcely distinguishable; mucro very perfect, post-median like 'inyhumi, but rather more elevated, as is the rest of the shell." Subgenus MAUGERIA Gray, 1857. .!/'/<"/' rm (i KAY, < iuide Syst. Dist. Moll. IJrit. Mas., p. 183 (in part). — Ac'iHthojileiira CAKTI \ri.i:, Table Reg. Chit. 1873, and Dal I. 8, Nat. Miis. 1881, p. 284, 289, 290 (in part); Not / Guilding, q. v. Exterior lusterless; tail valve having numerous (7-12) slit- in the short crenulated insi-rtiun-plate, median valves 1-slit, the exposed coating or tegnientum widrr than the articulanu-ntuni or inner layer; 227 sinus not toothed, the sntural plates connected across it; thick, densely beset witli calcareous spinelets. Type < '/t. 'jranulatus (Jinel. ThU •ubgenua or section differs from Acl>,i,- Jlnrbor, Vaccas Key, etc., Flnriil'i : •/ Indie^ southward to Trinidad and the Spanith Miceus GMEL., I c. no. 17, p. 3205 (Chemn. viii, p. 285, t. 96, f. 807-810).— WOOD, Gen. Conch., p. 8, t. 1, f. 3.— SOWERBY, Conch. Illustr. f. 147.— SHUTTLW., Bern. Mittheil. 1853, p. 78, and of most later writers on the Antillean fauna. — Chiton occidental™ REEVE, Conch. Icon., t. 14, f. 77a. (1847). — Chiton sala- '!rr SPENGLER, Skrivter af Naturhist. Selskabet, iv, p. 80 (= Chemn. viii, f. 806. — Chiton tuberculatus L., SCHROETER, Einleit. iii, p. 494, t. 9, f. 19 ("Der cylindrische Chiton ") ; not C.tubwula- t\i8 Linne. — Chiton nnguiculatus BLAINVILLE, Diet. Sc. Nat. xxxvi, p. 544. — (7. conrexus BLAINV. /. c. — Chiton (Acanthopleurd) blaum-ri SHUTTL. Journ. de Conchyl. 1856, p. 170. — ? C. (A.~) mucronulatus SHUTTL., Bern. Mittheil. 1853, p. 79. This species is the common Chiton of the West Indies, being abundantly distributed throughout the group, the specimens before me being from the following localities : Bermuda (Heilprin) ; Key Vaccas, Florida (Calkins, Hemphill) ; Bahamas (H. C. Chapman, J. J. Brown, F. Stearns) ; Jamaica (Johnson and Fox) ; San Dom- ingo (Gabb); St. Thomas (Swift); Dominica (Sharp) Monos, (Sharp) ; Atlantic coast of Costa Rica (Gabb). The specimens are almost always eroded, the original color and sculpture being quite lost. Although the species is very variable, no local forms deserving varietal rank are known to me. Figures 39-41 represent a St. Thomas specimen, eroded in the usual manner. Fig. 48 is also drawn from a St. Thomas specimen in which the sculpture is perfectly preserved, and the color uncom- monly dark. Figures 44-47 represent valves of examples from St. Domingo. The non-eroded forward part shows a central brown band, with a flesh-colored band on each side of it. This coloring is also found in most specimens from Florida Keys (fig. 43), Jamaica, St. Thomas. Specimens from the Bahamas have the two light stripes blue-white, and are strongly corrugated. Tho tail-valve varies greatly in respect to the prominence of the mucro. In some specimens (fig. 46) it projects beyond the pos- terior edge of the valve ; in others it hardly attains the edge; but these variations do not seem to be correllated with other characters. Li \M -IIMI-I i ri:\. 229 The identity of C. mallri I ri: \ Keadilv rec.. Lrni/ed l>y the Mack, irranulated ridtt, an. I HBOOthet ;riped rid.ire, in connection with the peculiar insertion-plate of tin- tail valves. Smith has placed the species with douht in the synonymy of A» »i»iiii[icr, where it certainly does not belong ; and Martens, also erroneously, suggests its identity with ('It. i>ctli<>lpl'-imi brcvi-xpinoaa ROCHEBR., Nouv. Arch, du Mus. J881, p. 240. Part of the localities given above are probably incorrect, A good many shells procured at " Cape of Good Hope" and "Zanzibar" 232 never grew at those places. The evidence in favor of the Comoro Is. is more satisfactory. This species is closely allied to A. borbonica in sculpture, but it differs in having flatter, thinner valves, longer, white-tipped spines, in lacking the white dorsal stripes as well as in the color of the inte- rior. Finally, the characters of the tail insertion plate differ. Subfamily LIOLOPHURIN^E. Median and anterior valves provided with eyes, and having well- developed insertion-plates with slits, the teeth pectinated outside, not thickened at the edges of the slits. Posterior valve with the mucro posterior and terminal ; its insertion-plate obsolete, reduced to a low ridge or flat ledge of callus, which is unslit (except in Schizochiion ) and continuous posteriorly or interrupted in the middle by a caudal sinus. Gills as long as the foot. This group is closely allied to Chitonidce and has doubtless been derived from the Tonicioid branch of that stock. It is separated from them on account of the degeneration of the posterior valve and esj>ecially its insertion-plate, — a character of vastly less importance than Carpenter supposed. The median notching of the tail valve behind is also extremely variable, as is exemplified by such closely allied forms as Lorica volvox and L. angasi. All of the genera of >nidcet Chiton, Eudoxochiton, Tonicia and Acanthopleitra, show species in which the tail valve has an incipient caudal sinus, or in which the insertion-plate is becoming obsolete, or both conditions. It is only necessary to mention Chiton jugosus (p. 178), Eudoxochiton (pp. 193, 194), Tonicia confossa (p. 210); Acanthopleura sjrinigera, all showing more or less posterior emargination ; Acanthopleura grnnii/nfu and the section Amphitomura have the posterior insertion- plate very short, some forms of the latter having it nearly deprived of slits. Compare with these Schizochitou and Lorica, the latter having the insertion-plate short but distinctly creuulated. It is probable that deposits not older than Miocene will furnish the generic links now missing between the series of forms here included tnd those grouped in L i»lo/> h ///•/// Ontthochiton. outside, ponvllanous \vitlnn; girdle [leathery, nude. f Eyes scattered among the tubercles! of the surface, which is rough and Maugtna < . . ' . ' . .. }• Liolophura. lusterless ; interior dark ; girdle [clothed with calcareous spines. (Eyes very minute, oval, scattered;! surface of valves brown and polished I — 7 , . ,. > Enoplochiton. outside when not eroded, peculiarly sculptured inside. The genera Lorica and Schizochiton have no representatives in the Toniciitice, for while they are closely allied to the latter, they have been differentiated along a line away from that taken by Onitho- chiton and its immediate allies. Synopsis of Genera. A. Median valves having eyes developed only on the diagonal ribs. Sinn* notably narrow and small. Insertion-plate of tail valve a low, rounded, rugose ridge more or less notched or waved upward in the middle behind, or sharp, long and pectinated. B. Eyes large, situated on the diagonal ribs and on the ribs of the head valve, the latter corresponding to slits in the insertion-plate. Girdle having minute calcareous spines. Genus XVI. SCHIZOCHITON Gray. Much elongated. Posterior valve having a deep caudal sinus with one or two notches on each side of it in the insertion-plate. Head valve with few (about 6) slits. Girdle sparsely, finely spinulose, slit behind. BB. Eyes reduced to minute, fuuctionless punctures on the summit of the diagonal ribs, and entirely absent on the head valve, the riblets of the latter not corresponding to internal slits. Qifdfa dfnseli/ s<'ah/. Genus XVII. LORICA H. & A. Adams. Oval or ovate, elevated. Posterior valve having a deep caudal sinus or a shallow wave, the insertion-ridge otherwise uninterrupted. 234 SCHI/OCHIToN. Head valve with numerous (8-10) slits. Girdle den-ely clothed with minute, convex, crowded scales. Section LORICA s. str. Caudal fissure deep ; sinus v-shaped ; girdle widest at the sides, slit behind. ^ Section LORICELLA Pils. Caudal fissure reduced to a shallow wave; sinus bilobed ; girdle widest in front, not slit behind. AA. Eyes developed upon the lateral areas. Sinus wide and large, 'ion-plate of the tail valve reduced to a smooth ledge or ridor, N. S. Wales; Port Lincoln, S. Australia, under stones at extreme low tide. 238 r/,/Vo/, m/vn.r JiKEvi-:. Conch. Icon., t. 6, f. 31 (Feb., 1847).— /,<>,- it-'t i-ulrn.c (Rve.) IlAnimN, 'Challenger' Polyplac., p. 31. — Chiton cimol!".< Hi: i:\ i :. Conch. Icon., t. 21, f. 141 (May, 1847). — L rhnoli'i \\. & A. AD., Ann. Mag. N. H. (2) ix, p. 355. — ANGAS, P. /. S. 1SG7, p. 224; 1871, p. 97. — Aiilacochiton volvox SIIUTTL., Bern. Mittheil. 1853, p. 68.—? Chiton nulls HUTTON (see below.) The differences between L. volvox and L. cimolia are easily effaced when a good series is examined. The yoilng show great variation in the pustulation of the lateral areas, the pustules sometimes being scattered, radiating, cords obsolete. The dorsal ridge generally has a central fine carina with a long narrow smooth triangle on each side, but this varies also. The second valve has a rather large median patch of scattered or diverging series of pustules. The color- ing varies a good deal in the series before me. ' I am disposed to consider Hutton's Chiton rudis a synonym of this species, but my opinion is founded upon a study of the original description only, which is as follows : Chiton rudis Hutton. Oblong; margin with minute scales; valves elevated, flattened on the sides, not keeled ; apex of anterior valve recurved, with its posterior margin slightly convex at the sides and deeply concave in the center ; posterior margins of intermediate valves straight ; posterior valve rather small ; apex posterior, pointed and emarginate. Anterior valve and lateral areas with radiating moniliform ribs ; posterior and median areas widely but rather irreg- ularly, deeply longitudinally furrowed, with narrow ridges between Margin gray, with broad, irregular, reddish-brown transverse patches; valves grayish-brown ; interior grayish-white. Length 1*75, breadth '75 inch. Founded on a specimen in the Colonial Museum, locality not stated. (Hutto.i, in Trans. N. /,- Inst. iv, 1872, p. 179, and Man. N. Z. Moll. 1880, p. 113.) Section Loricelli Pilsbry. Sinus in tail valve a mere wave ; jugal sinus lobed ; girdle widest in front, not cleft behind. L. \\<. AM Adam- and Angas. PI. ~>1, figs. 9-13. Shell ovate, coarctate and angulate behind, pale brown, variegated with green. Anterior valve concentrically striated and having radiating pustulose ribs ; posterior valve narrow, transversely silicate and densely longitudinally lirate; median valves subcarinated, the central arras driiM-ly lirat»- and t ran.-vi-r-rl y siilraH-d; tli.- lateral area- elevated, radially lirate, tin- line jmst ulose. (iirdle moderate, nlivaeemi-, L-sct with minute scales. Leii-th H>. luva.lth I'll mill. < If. .!i<-,•, /'„,-/ ./<"•/. vo>,, N. S. I !",//,•.>• llra/ier). In deep water. Lorica angati II. AD. . I have not seen this species, which is here figured for the first time, from drawings made by Emerton for Carpenter, who writes as follows : " Anterior valve large ; posterior valve small, the mucro terminal, much elevated, prominent ; diagonal ridges elevated ; dorsal ridge acute. Interior : posterior valve a little sinuated behind, the sinus wide; having two callous, subobsolete, slightly roughened ribs in place of the insertion-plates. Anterior valve with 10, central valves 1 slit ; teeth acute, serrated outside and at the edge ; eaves prominent, deeply grooved ; sinus narrow, deep ; the sutural plates separated, but having a lamina between them which is sometimes bilobate or denticulate. Girdle reduced one-half in width behind, and sinuated, very closely beset with solid minute scales, seen under a lens to be obsoletely bilobate. Length 32£, breadth 22J mill, ; divergence 110°. " One of Mr. Cuming's specimens is much broader and somewhat tripartite. This species differs from the typical Lorica in the anterior projection of the girdle ; in the minute raised scales, which under the microscope look like grains of wheat set on end ; in the sinus having a separate lamina, somewhat lobed ; in the absence of anterior * false apex ' on the valves ; and finally in the mucro being terminal and but slightly waved, with a correspondingly slight wave in the girdle behind." The " hairs " shown on the girdle in fig. 9 are foreign to it. Genus XIX. LIOLOPHURA Pilsbry, 1893. Liolophura PILS., The Nautilus vi, j>. 105 (January, 1893). — Acanthopleura sp., of authors. Valves exposed, dull and somewhat roughened, irenerally erodrd outside, with minute eyes irregularly scattered over the lateral i the head-valve and the sides of the central areas. Interior dark 240 LIOLOPHURA. colored, having anterior and side insertion-plates slit into teeth and sharply pectinated outside ; posterior valve with posterior terminal mucro, lacking the insertion-plate, which is represented by a flat callous ledge. Sinus wide, deep, smooth. Girdle covered with stout calcareous spines or obtuse club-shaped processes. Type Chiton japonicua Lischke. The species of this genus have been referred to Acanthopleura, Mmiyrin and Chiton by authors who have mentioned them; but from these groups the characters of the tail-valve at once sunder them. Liolophura resembles Onithochiton and Enoplochiton in hav- ing a callous ridge in place of the posterior insertion-plate, in the pectinated teeth of the other valves, and in the possession of eyes ; but it differs from Onithochiton (a) in the somewhat rawed instead of marginal mucro, (b) in the dullness of the valves externally, (c) in the distribution of the eyes upon the sides of the central areas, whilst in Onithochiton they occupy a band on the forward part of the lateral areas only ; and finally (d) in the covering of the girdle which in Liolophura consists of densely crowded calcareous spines, comparable to the spines of Maugeria. Liolophura differs from Enoplochiton in lacking the interior sculpture and denticulate sinus characteristic of that genus, and in the totally diverse development of the girdle covering. L. GAIMARDI Blainville. PL 53, figs. 30-35. Shell oblong, depressed, roundly arched. Surface lusterless, buff- gray, marked at sides and on ridge of valves with black. Girdle tessellated light and dark, having a light bar opposite each suture, or having dark or light larger patches. The valves are somewhat beaked, but always considerably eroded ; lateral areas but little raised, concentrically wrinkled toward their bases, studded with minute scattered eyes appearing as black dots. Central areas wrinkled by lines of growth and having scattered eyes at the sides. Head valve concentrically wrinkled, studded with eyes. Tail valve small, depressed, similar in contour to the median valves, the mucro being posterior and terminal, but eroded. Interior dark red-brown, whitish on the edges of the sutural-plates and the valve-callus; posterior internal margin covered by the reflexed blackish-brown tegmentum. Sutnral-plates brownish below with a white outer edge ; seen from above they are whitish shading into reddish-brown toward the median sinus; rounded, broadly separated by a very wide, deep, rounded sinus. Anterior valve hav- i KM oi'HtjRA. 241 ing 9, central valves 1 slit : the teeth deeply, el.xely pertinatrd out- side. Posterior valve having the eaves projecting beyond the l.road, flat crescent of callus which occupies the place of an insertion-plate. ( Jirdle densely clothed with intermingled minute, larger and large calcareous spines, (fig. 31.) New tiouth Wales (Wilkes) ; Port Jackson (Blainville, Coppinger and Challenger Kxped. > Australia. Chiton incanns GOULD, Proc. Bost. Soc. Nat. Hist. 1846, ii, p. 145 ; U. S. Expl. Exped., p. 315, t. 28, f. 432, 432a ; Otia, p. 6.— Maugeria invtnus GLD., Otia, p. 248. — Acanthopleura incana E. A. SMITH, Zool. Coll. H. M. S. ' Alert,' p. 81, 1884.—? Chiton piceu* ANGAS, P. Z. S. 1867, p. 223.—Acanthopleura (/) incana (Old.) HADDON, Challenger Polyplac., p. 25 (in part.) — Chiton gaimardi BLAINV., Diet. Sc. Nat. xxxvi, p. 546, (1825.) This species may readily be separated from all forms of Acantho- pleura by the peculiar flat callus of the tail valve inside, altogether lacking the pectination and slits which are present in Acanthopleura. It differs also in having eyes scattered over the sides of the lateral areas, and in having some of the girdle-spines striated. It differs from the Japanese species in the differently colored interior and sutural-plates, in the details of girdle-structure, etc. The spines on the white tracts of the girdle are unicolored whitish ; on the dark tracts they are of a uniform black-brown color. Occa- sional spines are striated like the scales of Ischnochiton. L. GEORGIANA Quoy and Gaimard. PI. 53, figs. 36-40. Body oval, thick ; girdle narrow, granulose, whitish with 8 white stripes; valves arcuate, flattened, thickly striated ; brown, black in the middle. The body is short, oval, much swollen ; girdle very thick, little dilated at the sides, covered with very small rounded tubercles, white with 8 black bands across each side. Foot narrow, yellowish. Branchiae reaching to the buccal fringe, which is large. Valves very wide, covering nearly the whole body, semicircular, but little elevated, narrowed, somewhat heart-shaped, very thick ; having concentric striae, the anterior and lateral most marked; of a deep brown color at the sides, lighter in the middle with a black dorsal line ; fourth and fifth valves equal and wider than the others. Inside the valves are of a violaceous brown ; median valves with an arcuate thickening. The sutural plates are short, rounded, separated by a flat, straight median sinus. Insertion plates slit and crenulated. 16 242 LIOLOPHURA. Anterior valve having 12 to 15 short, unequal, deeply striated teeth. Posterior valve triangular, flattened, with a callus in place of the insertion-plate. All of the apophyses (which are of a horny color) have a brown spot at the angle. Length 19 lines, breadth 1 inch. (Q. & a a. This species resembles the stout, elevated, dark olive forms of 0. nmlnlatus, such as occur at Auckland, N. Z., in contour and colora- tion. It differs markedly from undulatus and all other known species in ttnr«l at the sides with fine, close grooves (continued from those of the lateral areas) converging toward the ridge, where there is a narrow smooth dorsal band. Anterior valve having about 10 narrow rays of eyes, the spaces between sculptured with concentric grooves interrupted by the eye-bands into scallops having their convexity upward, terior valve broadly triangular, depressed. Interior white with a crimson spot in the cavity of each valve. Sinus deep, angular, delicately subdenticulate. Anterior valve hav- ing 8, median 1 slit ; the teeth rather long, sharply pectinated out- 248 ONITHOCHITON. side. Posterior valve having a smooth callus in place of the inser- tion-plate, separated from the eaves by a groove at each side. Girdle leathery, closely clothed with microscopic down, clouded brown and whitish. Length 42, breadth 20 mill. Pitcairn Island, in small hollows, at low water mark (Cuming) ; Raine's Island, Torres Ste., under stones at low water (Ince) ; Wat- son's Buy, N. S. Wales, Australia, at very low tides (Angas.) Chiton lyellii SOWB., P. Z. S. 1832, p. 26 : Conch. Illustr. f. 7.— REEVE, Conch. Icon., f. 12. — Chiton incii REEVE, Conch. Icon- no. 94, t. 16, f. 96 ; detail fig. 94. — Chiton puncticulatus REEVE, Conch. Icon., t. 13, f. 696 and description in part — Onithochiton incei ANG., P. Z. S. 1867, p. 223. This species differs from O. maillardi in the narrower smooth dorsal areas, the less deep, less regular grooving of the lateral areas, and the shorter and broader posterior valve. It relations to the following species are not clear to me, as I have seen no authentic specimen of the latter. Figs. 8, 9 of pi. 55 represent the C. incii of Reeve. The Chiton puncticulatus of Reeve seems to have been founded on a specimen of this species and one of Pallochiton lanuginosus ; but Reeve's reference to the punctation seems to apply best to this form. In any case, the name is so ill-defined that it cannot in fairness be used. O. QUERCINUS Gould. PI. 55, figs. 12, 13. Shell small, depressed, slightly carinateand beaked, ovate, yellow- ish wood or oak color, clouded with olive or dusky slate color at the sides. Lateral areas scarcely raised, but distinctly marked by coarse longitudinal sulci, which are divided by a radiating furrow and sometimes more, and the two portions form somewhat of an angle with each other; central areas with faint, rugose, longitudinal lines toward the margin, and scattered punctures about the apex ; anterior valve checked with raised spaces formed by concentric and more distant radiating furrows, which become more numerous near the margin ; posterior valve with theumbo nearly terminal, so that the transverse ridge runs nearly parallel to the margin. Marginal ligament broad, yellowish, frosted. (Old.) Length 22, breadth 15 mill. New South Wales, Australia. i . N 1 1 1 1 • M • 1 1 1 1 249 Chiton quern' n n< «.M... Pro< Nut. Hi-t. ii, p. ML' (1846); U. S. Expl. Erped M.,11., p. .'{12, f. 437, 1870; <>ti:i Conch., p. 3. — C. (f)nitlnn'hitnn) >jii' GH i'. ()tiji, p. -42. Closely allied to 0. /y< /// and O. /•»/;/ "fosus. O. RuouLoeuB Angas. 1M. :>:>, fig. 19. Shell elougately ovate, a little narrowed in front, raised and car- inated, pale yellowish-brown, the central areas of the valves faintly spotted with olive, the outer edges bordered with green, upon which and extending inward are concentric waved bands of olive brown darker at the margin; lateral areas not raised, divided from the dorsal areas by radiating nodulous ribs, transversely rugosely, costate ; dorsal areas finely longitudinally ridged ; mantle brown, variegated with ash-color and clothed with very minute chaff-like scales- (Aug.) Length 16 mill. Port Jackson, Australia. Onithnclnton rugnlosns ANG., P. Z. S. 1867, p. 115, 223, t. 13, f. 29. Carpenter gives the following notes upon the type specimen : Shell broad, the valves much beaked, dorsal ridge acute. Mucro terminal. Jugal area scarcely distinct, smoothish ; central areas having about 16 nearly longitudinal, jagged wrinkles, nearly meet- ing over the jugum. Lateral areas very sharply rugose, much more so than in the other species, the rugse about 12, not developed in young shells, very irregular, swelling into granules especially «>n the diagonal lines and sutures. Anterior valve having 8 lines of black dots, with two additional, indistinct ones. Inside whitish with a brown spot in the cavity ; posterior valve having the mucro absolutely terminal, the insertion-plate planed off. Anterior valve having 8 slits; teeth very finely rugose; sinus deep, flat, tolerably broad, with about 20 fine teeth. Girdle covered with minute hairs. Length 16$, breadth 12 mill.; divergence 125°. O. AMICORUM Baird. PL 54, fig. 46. Shell rather elongated, elevated, with acute dorsal ridge. There is a line of reddish-brown color along the dorsal ridge, and one or two others along the sides. Lateral areas much elevated, with very nodulous wrinkles, two or three irregularly concentric ; these are partly on the diagonal and sutural ribs, with others intercalated. Central areas with about '2'2 slightly irregular riblets, nearly longitudinal, but bending toward the 250 ONITHOCHITON. middle, the interstices very narrow. Anterior valve having about 20 radii, much smaller than those of the lateral areas, but toward the sutures becoming coarser than those of the lateral areas. Poste- rior valve depressed, the mucro subterminal. Interior: anterior valve having about 9 slight slits, not corre. spending to the outside dots. Central valves with 1 slit ; teeth striated outside and at the broad, but sharp edge. Eaves planed off, scarcely grooved. Sinus broad, deep, with about 14 denticles. Girdle stout, with shelly spines, exactly like magellanicus, prin- cipally whitish, irregularly tessellated with dark. (Cpr., from type.) Length 18, breadth 10 £, divergence 90.° Nine or Savaye Island, Friendly Group (Brenchlev.) Chiton ( Onithochiton) amicorum BAIRD, in Brenchley's Jotting* during the Cruise of H. M. S. 'Curacoa' among the South Sea Islands, in 1865. London, 1873, p. 445, t. 40, f. 7. The generic position of this species is uncertain, but could be readily ascertained by an examination of the type, which is, we believe, in the British Museum. It is probably either an Onithochiton^ a Liolophura or a Plaxiphora. Baird's original description is as follows: "Shell ovate, nearly equal at each extremity; mantle margin covered with numerous chaffy-looking scales, first valve larger than any of the others, marked with numerous granular lines ; central valves strongly striated, lateral areas with 2 or 3 granular lines ; last valve small and striated. A line of a red color runs along the top of all the valves, whilst "one or two others run along the lateral areas. Length 8 lines, breadth 5J lines." O. MAILLARDI Deshaves. PI. 55, fig. 20. Shell oblong, elevated, the dorsal ridge roundly angled, side- slopes nearly straight. Surface shining ; color pale buff, with a nar- row orange-tinted or brown triangle at the ridge of each valve, several dark -green spots along each diagonal slope, the lateral areas and head valve with concentric green-olive sometimes dark brown lines. Median valve beaked, the lateral areas somewhat raised, having near the front margin a narrow radiating band of eye-dots, the width of the band greater on the hinder valves; sculptured with longitu- dinal grooves corresponding with the dark color-lines, sometimes irregular or branching; and continuing upon the diagonal slope. Upon the central areas these grooves become much more delicate,. <>M I II... in I closer, M>D Vtfging tOWftrd tin- dorsal riil^r. and oftni /igzagged ; the median triangle of the central arras >inooth. A ntrrior valve having 8 narrow rays of ryes, i.rra-ionally with ,-onie eye- >eatt« red between along the lower margin ; the intervals between the eye-rays sculpt- ured with sulei forming short arcs of concentric grooves. Posterior valve depressed, triangular; //••« /on/tit from sinus to ///'• //".iterior terminal inncro briny one- half the greatest breadth of its tegmentum. Interior white, with a large spot of rich brown in each valve. Sinus delicately toothed, wide and deep. Anterior valve having 8 slits, median valves 1 slit ; teeth finely and sharply pectinated out- side. Posterior valve having a smooth ledge of callus in plate of the insertion-plate, flat behind, rounded at the sides. Eaves narrow, grooved, solid. Girdle fleshy-brown, leathery. Length 24, breadth 15 mill.; divergence 110°-115°. Mauritus and Bourbon (Reunion.) Chiton maillardi DESH., Moll, de File Reunion, p. 38, t. 5, f. 14. — Chiton (Toniciaf) maillardi MARTENS, in Mobius' Reise nach Mauritius, p. 300. — Ornithochiton maillardi CPR., MS. — Ornitho- chiton sp., MOSELEY Quarterl. Journ. R. Mic. Soc. xxv, p. 54, t. 5, f. 4-7. O. LITERATUS Krauss. PI. 55, figs. 21, 22, 23. Shell ovate, convex ; brown, spotted with whitish and having a whitish longitudinal band ; closely silicate. Interior white, brown- ish-violet in the middle. Anterior valve lunate, convex with undulating grooves ; posterior valve triangular, depressed, sculptured with angular grooves; intermediate valves sinuated in front, rounded at the sides, undulately and angularly grooved. Girdle rufous-brown, leathery, velvety. Length 12, breadth 8 lines. (Krauss.) Natal. Chiton literatus KRAUSS, Die Siidafrik. Moll. p. 36, t. 3, f. 6. I have not seen this secies, which is evidently quite distinct, although allied to 0. maillardi. The central areas have angular or zigzag grooves; the lateral areas are not raised, and are sculptured with wavy grooves. The back is not carinated. Insertion plates as usual in the genus. 252 ENOPLOCHITON. Genus XX. ENOPLOCHITON Gray, 1847. Enoplochiton GRAY, P. Z. S. 1847, pp. 65, 69, 169. Valves exposed, of a uniform dark brown or chocolate color out- side and within ; the lateral areas and head valve irregularly studded with extremely minute eyes. Interior minutely laminated and punctate in a peculiar pattern ; sinus deep, denticulate. Inser- tion-plates of anterior and median valves slit into teeth and sharply pectinated outside. Tail-valve having the mucro posterior and terminal, and inside with a flat ledge of callus in place of the lack- ing insertion-plate. Girdle fleshy, bearing extremely broad and short, blunt, separated striated scales. The single species comprised in Enoplochiton resembles the larger Onit/iochitons in being polished and sculptured with wavy impressed lines (when not eroded) and also in the denticulate sinus, as well as in the structure of all the insertion-plates. It differs from Onitho- chiton in the peculiar texture and color of the valves, the sculpture of the interior and the structure of the girdle. The eyes in this genus are extremely minute and oval instead of round. The megalopores and micropores are arranged in vertical lines (pi. 52, figs. 27, 28). The valves resemble those of Mesotoinura in most respects, excepting the tail valve, which is that of Onitho- chiion. E. NIGER Barnes. PL 52, figs. 22-29. Shell oblong, convex, the valves thick and dark brown outside and within. Surface shining when perfect, but generally eroded and dull. The valves are strongly beaked, and generally much eroded*; but when not too much worn the sculpture is as follows : lateral areas marked with undulating longitudinal impressed lines ; central areas having a series of short impressions in front of each diagonal rib, and an impressed V on the ridge of each valve ; anterior valve hav- ing concentric wavy grooves ; posterior valve much depressed, with posterior terminal mucro ; sculptured like the median valves. Interior seen under a lens to be sharply, densely laminate in front of the valve callus, punctate on the sutural plates and behind the valve-callus (fig. 25). Sutural and insertion plates of median vulves thick, tending forward; sinus broad, rounded or angular, denticulate; anterior valve having 9 slits, median valves 1 slit; teeth long, deeply, shaq^ly and closely pectinated outside. Posterior ISCIIN'M HI I"M I' 1 . valve having tin- inticro projecting beyond the narrow eaves; inser- tion plate obsolete, reduced to a callous ridge, flattened behind, rounded at tin- side.s and pectinated outside where it joins the sutural plates. Girdle fleshy, bearing numerous wide, short, blunt, striated, sepa- rated scales (fig. 29, a young specimen) ; the interstices between the scales covered with a velvety pile. Length 75-80, breadth 35-40 mill. Peru (Capt. Ridgeley) ; Coquimbo Bay (Frembly) ; Valparaiso (U. S. Expl. Exped.) Chiton niger BARNES, Amer. Journ. of Science and Arts, vii, p. 71, t. 3, f. 3 (1824).— Enoplochiton niger GRAY, P. Z. S. 1847, p. 69. — Chiton coquimbensis FREMB., Zool. Journ. iii, p. 197, t. 16, f. 2 (1827).— SOWERBY, Voy. 'Blossom' Zool., p. 149, t. 40, f. 6.— REEVE, Conch. Icon., f. 22. The entire substance of the valves is colored in this remarkable species. Specimens as well preserved as the individual figured are not common ; but so peculiar is the entire shell that it may readily be recognized, however eroded. This species like Acanthopleura spinifera, lives upon the rocks between tides in situations exposed to the full force of the surf. In fig. 27 a portion of the surface of a valve is drawn magnified, show- two eyes, megalsesthetes and micrsesthetes ; fig. 28 represents a por- tion more highly magnified, showing two megalsesthetes and the accompanying micrsesthetes. Family ISCHNOCHITONID^. A number of genera belonging to the Ischnochitonidce were omitted by me in my treatment of it in parts 1 and 2 of this volume, in deference to the views of Carpenter, who grouped them with Acanthopleura and its allies. A more profound study of this and related families, enables me now to see traits of relationship unknown at the time the synopsis on pages 23, 24, 25 was prepared, and there- fore to group the genera more naturally than was then possible. Subfamilies of Ischnochitonidce. CALLISTOPLACINJE, in which the slits of the anterior and inter- mediate valves correspond in position to radiating ribs on the exte- rior. (See p. 259.) 254 I8CHNOCHITOMN 1 -DINOPLAX. i, in which there is apparently no such relation between slits and external ribs. This last subfamily includes the majority of species, and a consider- able number of genera ; and while there are still some obscure points, the light cast by what we already know of their morphology is suffi- cient to show us the approximate paths of generic descent, the genera falling into three main groups, as shown in the diagram. 3 1 ; : 1 6 1 0 G H 1 r& r- g £^ ~~8 9- I ^ = £ O 3 Ischnochitoninse Callistoplacinse It will be noticed that Leptoplax and Spongiochiton are not included. These genera belong to the Acanthochitidaz. Moreover, it must be remembered that Trachyradsia is a synonym of Stereochiton (see p. 52) and part of Trachydermon belongs to the Tonicelloid branch. These groups were erroneously placed in the text. The following genera belong to the Chudopleuroid branch of Ischnochitoninae and should have been inserted after the genus Chcetopleura (p. 27.) Genus XXL DINOPLAX Carpenter, 1882. Dinoplax CPR. MS., in DALL, Proc U. S. Nat. Mus. 1881, p. 284, 287 (Jan. 20, 1882).— Acanthopleura (in part) GRAY.— Chwtopleura (part) Sur i n. I:\VMR MI.— r/,,7o» s. s. (in part) ADAMS, Gen. Rec. Moll, i, p. 474, 475, not of Linn. Valves heavy, exposed, the lateral areas high ; teeth of insertion sharp, smooth, those of the posterior valve directed forward; slits of anterior \alvr not rorn^|.ondin_r t<» i-xtrrnsil rilis. Posterior luiriii'i the vnici". }n>*teri'n-. Suitttal plafat fn-nml/i/ imitxl across the sinus. < iinllr thick, lent licry, with minute Imm'hes of delicate sjnne- lets scattered upon it. The position assigned by Shuttleworth to the type of this genus was not. tar from correct. The Ischnoid insertion-plates, solid eaves and the leathery spiculose girdle are characters strongly binding C. /t'nrtrrii>r valve wide, flat, sul»pongy; of other valves moderate, hardly Lrn>oved. Sinus narrow, dccj., hardly toothed, slit at the sides, at t he jmiet ion of the sutural plates. Girdle leathery, smooth or most minutely and closely downy. Length '2\l hreadth 16* mill; divergence 110°-120°. Habitat unknown. Arthur in filosa CPR. MS. and in DALL, Proc. U. S. Nat. Mus. 1881, p. 287 (name only). Types in Mus. Cuming, nos. 23, 38. Carpenter's description is given above. He remarks : " This shell has the tail plate of Nuttallina, but the other valves more resemble Chcetopleura or Tonicella. It is known externally from Nuttaffina by the nearly smooth girdle ; but would hardly be distin- guished from Omithochiton except by the regular articulation of the insertion-plates. In the Ischnoid genera, the posterior profile from the mucro is often concave ; in this the anterior. In consequence of the great projection of the beak, both in Nuttallina and Arthuria, the posterior teeth appear plumulate rather than fissured ; a char- acter also seen in Callistochiton. The terminal valve in both the specimens examined are exactly alike in color as well as markings ; but the central valves in one specimen are of a much lighter color, with more delicate and well developed sculpture." Subfamily CALLISTOPLACIN^E. Ischnochitonida3 in which the slits of the anterior valve correspond in number and position to the radial ribs of the exterior. Teeth generally thickened at the edges of the slits. In this subfamily, which seems to be a natural division, may be placed a number of genera widely scattered in Carpenter's scheme. These genera fall into three groups, or branches, lettered a, aa, and aaa in the following table. The first of them seems to have affinities with the typical Ischnochitons, the second slightly resembles the Acanthochitidve, and the third may be somewhat allied to the Mopaliidce. The number of anterior slits sometimes exceeds the number of external ribs, so that the subfamily diagnosis must not be taken too literally. The plan of structure is sufficiently obvious; but exuberant Nature knows nothing of absolute adherence to rules. 260 CALLISTOCHITON. K< y to genera of Callistoplacince. a. Surface of valves having strong radial ribs ; girdle densely clothed with imbricating scales, CALLISTOCHITON. aa. Surface of valves granulated or pebbly ; girdle not densely imbricated with scales. b. Anterior valve with more than 7 slits ; sinus very spongy ; imicro posterior, NUTTALLINA. bb. Anterior valve with 5 slits; mucro subcentral, not posterior, CRASPEDOCHITON. ANGASIA. aaa. Surface of valves wrinkled or ribbed ; girdle naked except for hairs or corneous spines. b. Valves having very strong radial ribs; girdle naked, with sutural tufts, CALLISTOPLAX. bb. Valves not very strongly sculptured ; girdle tough, with corneous curved spine-like processes, CERATOZONA. Genus XXIII. CALLISTOCHITON Carpenter, 1882. Callistochiton CPR., Table of Regular Chitons, 1873.— DALL, Proc, U. S. Nat. Mus. 1881, p. 283, 289, 290 (Jan.-Feb., 1882).— Callo- chiton (in part) H. & A. Adams, and of CARPENTER, P. Z. S. 1865, p. 276, not of Gray. Valves conspicuously sculptured ; the insertion-plates short, smooth or nearly so, festooned, being curved outward at the ribs and slit there, thickened outside at the edges of the slits, the latter corresponding in position to the ribs of the outer surface. Sinua squared. Mucro median or post median, generally depressed. Girdle poreless, densely clothed with minute striated or smooth scales. Type, Chiton pukhellw Gray. This genus differs from Ischnochiton in the peculiar insertion-teeth, which are curved into the ribs as if festooned, in the relation of the slits to the external ribs, and in the tail valve, which is often peculiarly humped. The species though not numerous, are widely distributed, Aus- tralia, Red Sea, Japan and the Gulf of Mexico together furnishing about half, the rest being from the western coast of the Americas, from southern California to northern Chili. Nearly all of the species have the lateral areas strongly bicostate and granose; the end valves have strong ribs, the number of which « \ i.i .1-1 n( inioN. 261 is le-< valuable :is :i specific cli;ir:ictcr than one would at first suppose, on account of their tendency to increase by splitting. When a rib splits, an additional slit appears in the insertion-plate; so that this character also is lamely vitiated. The best characters for distinguishing species are the sculpture of the median portion of the central areas, and the contour of the tail valve ; the profile of the latter being especially characteristic and constant. The following notes from Carpenter's MS. apply more especially to the more typical forms : " It is quite possible that in their earlier stages these curious shells resemble Ischnochiton ; but as they pro- ceed toward maturity, while they spread naturally in the seven ante- rior valves, the posterior is simply raised a tier higher ; consequently, in the adult, the posterior part of the tail plate resembles a closed fist outside; and within the teeth and eaves are very broad and blunt. There is an approach toward the throwing forward observed in Acanthopleura. In Ischnochiton, whatever be the external sculpt- ure, the row of teeth follow the same oval line, and the incisions do not correspond (except by accident) with the external ribs ; whereas in Callistochiton the tooth line is elegantly scalloped in and out of the hollows of the ribs. " In general the incisions are in the centre of each rib, and the plates are there propped outside, as in Callochiton ; but sometimes a separate keystone (as it were) is let into some or all of the arches on the terminal valves. The genus appears to culminate on the Cali- fornia coast, and reaches its greatest development in C. palmulatus ; in which the posterior valve displays the further peculiarity of each tooth being broken up into a number of fingers, each fluted, and so arranged that the inner margins form a semicircle while the outer present the scalloped curve of the genus. The valves are peculiarly solid and are easily detached from the thin and narrow zone. The sinus has always a lamina, which is generally marked off by slits from the sutural lamina, but is scarcely ever dentate. Two of the species have minute, smooth scales." Key to species of Callistochiton. One species, C. heterodon Pils., has pectinated teeth like a typical Chiton, and it is placed in this genus with much doubt ; the others may be tabulated thus : 262 CALLISTOCHITON. a. Central areas having a pitted or net-like pattern toward the beaks. b. Mucro posterior, not depressed, tail valve with 7 ribs; scales smooth, pulchellu*. bb. Mucro subcentfal, the slope behind it concave, scales striated, shuttleivort/i Inn n*. bbb. Mucro subcentral, tail valve rapidly sloping backward from the front margin ; eaves narrow ; scales striated, (inilquus. aa. Central areas smooth in the middle, decoratus. aaa. Central areas sculptured throughout with parallel lira. b. Posterior area of tail valve swollen above the anterior area, palmulatus. bb. Posterior area not higher. c. Mucro posterior ; riblets converging on ridge, crassicostaius. cc. Mucro subcentral, riblets not converging on ridge. d. Profile of tail valve convex, mucro obtuse, infortunatus. dd. Profile of tail valve rapidly sloping 'back- ward from the front margin, mucro flat, gabbi. The species elenensis and expressus from western Middle Amer- ica, and adenensis from the Red Sea, probably belong in the last section of the above table, but I have seen no specimens. C.jacob- &U8 of Gould also belongs near infortunatus, probably. C. PALMULATUS Carpenter, n. sp. PI. 58, figs. 7-16. Shell similar to C. pulchellus, but more flattened, the dorsal ridge acute; mucro subcentral, depressed, the posterior area strongly swollen; sculpture stronger; central areas having about 10 sub- parallel acute line on each side, pectinatiug the sutures, interstices deeply cancellated; lateral areas having two strong ribs bearing strong tubercles, the sutures dentate, interstices deeply punctate. Anterior valve having 11 ril>>, of which the outer two are joined; posterior valve 7 very strong ribs bifurcating behind. Interior: anterior valve having 11 slits, central 1 slit, the teeth normal ; posterior valve having 26 slits, the teeth crowded, minute, palmate. Eaves very strong; sinus small, strongly laminate, the • M.i.isTorm i' W, lamina di-eply slit on each side, (iirdlc imbricated with striated scales. Lcnirth 1 1 !, hrradth 7-1 mill.; divergence l-'if)0. (Cpr.) N/rf. n.irbnra (Cooper, Cal. State Coll. no. 1077) ; Monterey (Can- field, coll. Cpr.) The above description is quoted from Carpenter's MS. He gives the following additional notes: " This species with a general resem- blance to pulchcllns, is known outside by its stronger sculpture, flat- tend anterior and tumid posterior valve ; and by its sharp back with flattened sides. It is one of the most remarkable peculiarities of Chitons that they are so particular in special adornment of their tails, while their heads are covered with very uniform plates. In this species this peculiarity culminates. Not only the radiating and fur- belowed arrangement of the teeth presents the greatest differentiation yet observed in a Chiton, but the fluting of each individual finger- like tooth adds special beauty to the complex pattern." Figures 7, 8, 13-16 are from drawings prepared for Dr. Carpenter ; fig. 12 represents the tail valve of a typical specimen before me, for comparison with that of the following variety. Var. MIRABILIS Pilsbry, n. v. PI. 58, figs. 7, 8, 9, 10, 11. Shell oblong, elevated, the back angular, side-slopes convex. Surface lusterless, dull brownish, the lateral areas and end valves blackish. Valves not beaked; the lateral areas widely separated by the eroded beaks, greatly elevated, each split by a deep median sulcus, the two ribs thus formed bearing coarse transverse grains. Central areas sculptured with about 15 narrow longitudinal cords, parallel at the dorsal ridge except on the second valve in which they diverge forward ; the interstices wider than the cords, and finely latticed across. Anterior valve having 9 stout radiating ribs, strongly granose, and with the exception of the two outer ones, they are generally not bifid. Posterior valve much higher than the anterior, the mucro somewhat in front of the middle, the area behind it enormously developed, > I r\ . \ery oloeelj and finely latticed across. Anterior v.<, cadi divided by a shallow median gTOOY6. I'oste- rior valve elevated, having ///' macro directly over the }> '/.'/', //' hinder ttrcn not h'njln-r than the arco in front of it; posterior slope vertical, convex, sculptured with live very strong, deeply separated ribs, which are i^rauose above, and subdivide into several riblets each toward the lower margin. Interior bluish-white ; sutural-plates slightly connected across the rounded sinus. Anterior valve having 9, central valves 1, poste- rior valve 13-20 slits ; teeth short, rather sharp and smooth, hardly projecting below the eaves, thickened along the slits outside ; eaves broad, solid. Girdle narrow, thin, covered with excessively minute, closely imbricating, striated scales. Length 22, breadth 9 mill. Monterey, California. Callixtochiton fimbriatus CPR., MSS. 1875. Not Callochiton fim- briatus Cpr. in COOPER, Geographical Catalogue of the Mollusca found west of the Rocky Mountains, between Latitudes 33° and 49° North (Geol. Surv. of Cal.), p. 23, 1867 (no description),^ Callisto- chiton pulchellus, Cpr. MSS. 1875. ? Chiton ( Callochiton} fimbriatus Cpr., ORCUTT, Proc. U. S. Nat. Mus. 1885, p. 544 (1885), no description. Not Chiton fimbriatus SOWB. This species is readily separated from the next by the smaller number of ribs on the head and tail valves, the less distinctly bicos- tate lateral areas, and the far less elevated tail valve, which has, besides, a posterior terminal mucro. The specimens before me were collected by Henry Hemphill at Monterey. A species under this name has been reported from San Diego and from Catalina Island, but the identity of the specimens with the present species is open to doubt, although its occurrence in those places is not improbable. The name of this species is involved in some obscurity, owing to the fact that no diagnosis or description whatever has heretofore been published, although the name fimhrintns has appeared in several lists. This much however is certain: that the original fimhrintn* Cpr. of Cooper's Catalogue, the unique type of which is said to be in the Smithsonian Institution collection, is not the fimbrixfus of Car- penter's later MSS. ( Vi>1>- < 'arpenter's MSS. vol. I, p. 135) ; and we 266 CALLISTOCHITON. have no means of knowing whether the C. fimbriatus of Orcutt's San- Diego list was identified from Carpenter's earlier type specimen, or his later MSS. Everything considered, the best course open to us seems to be the selection of an entirely new name. The type is in the collection of the Academy. C. INFORTUNATUS Pilsbry, n. sp. PI. 59, figs. 37-42. Shell large, regularly ovate, the dorsal ridge obtuse ; valves arcuate ; mucro obtuse, median. Olivaceous, sometimes spotted with paler on the ribs and jugum. Central areas having about 12 parallel lirse on each side, decussated, the interstices having square depressions. Lateral areas having two very strong rounded tuberculose ribs. Anterior valve with 9, pos- terior with 7-8 elegantly spreading ribs. Interior: posterior valve having 7-8, central 1, anterior 9 slits ; teeth concave outwardly, obtuse, slit at the apices of the ribs, some- times with an intercalated slit or abnormally serrate ; teeth of poste- rior valve very obtuse, hardly sloping ; eaves small, delicate. Sinus wide, flat, but little angular, sometimes crenulated by the riblets of the exterior. Girdle irregularly imbricated with flattened scales, each one about 6-striated (fig. 39.) Length 17*, breadth 8| mill. Equador (Cuming) ; La Paz, W. Mexico (Pease.) Callistochiton pulchellus CARPENTER, MSS. Not C. pulchellus Gray, q. v. The sculpture of the central and lateral areas resembles that of C. palmulatus, but the tail-valve (figs. 38, 42) is entirely different in form. This shell was sent to Dr. Carpenter by Cuming as the true C. pulchellus of Gray, but it is certainly not that species. The above description and the figures are from Carpenter's MSS. and unpub- lished drawings of his type. The shell recorded by Dr. J. G. Cooper from " Catalina (or other?) I., Cal." under the name Callocliitmt ihnbrintus Cpr. MSS., and by Carpenter (in MSS.) from " S. Pedro " (both referring to the same specimen) may be a variety of this species, but no definition of it has been published, the locality is uncertain, and Dr. Carpenter in his later MSS. shifted the n&m6 fimbriatut to another species, leaving the form under discussion as a nameless variety of his C. pulchellus. Under these circumstances it has been thought best to expunge the name fimbriatiui from the list of valid species. OALUVfOCHITOV, -'•" C. JAC«»i; r.l s (Jould. f'ntiiflli'cd. Shell small, ashy, elongated, elliptical, hardly carinate.l ; end valves very lar^-, vaulted, ornamented with 10 scaly nuliatinir ril>> ; central areas cancellated; lateral areas conspicuous, bicostate. Ligament narrow, covered with minute elongated scales. Length 12, breadth 5 mill. (UM. ) Interior: posterior valve having 7, anterior 10, central 1 slit; teeth acute, curved outwardly ; eaves solid ; sinus wide, nearly flat, laminate, the lamina more or less separated from the sutural plates [by notches at the sides of the sinus]. Girdle imbricated with flat, striated scales. ( Q>r.) Simoda, Japan (North Pacific Expl. Exped.) C. (Leptochiton) Jacobceus GLD., Proc. Boston Soc. Nat. Hist, vii, p. 164 (Dec., 1859) ; Otia Conch., p. 117. — Caltistochiton jacobceus CPR., MSS. Carpenter gives the following notes ; but it must be remembered that his C. pulchellus is not the true pulchellus of Gray. " If this shell had come from Central America, I should certainly have regarded it as C. pulchellus with which it exactly agrees in sculpture, number of ribs, size andstriation of the scales, and general aspect. Indeed it can scarcely be separated as a variety, like the Californian shell. Inside, however the teeth are somewhat sharper, one of them having an extra slit. The lamina which lines the sinus is very thin and sharp, generally (but not always) marked off' from the sutural plates by slight slits. In some valves, the lines which mark it off are perceptible, but they do not serrate the edges. It is also much broader in some valves than others. Whether the species are or are not identical, cannot be decided from the single specimen in the Smithsonian Museum. It is very singular that a shell from equatorial S. America should be replaced by a very distinct species in the Bay of Panama, should reappear in the Gulf of California, be still found in the temperate seas of California and lastly display a representation on the shores of Japan." (CJpr.) C. ELENENSIS Sowerby. PL 59, figs. 27, 28. Shell oblong, pallid ; back rounded; anterior valve radiately sul- cate ; lateral areas of the intermediate valves swollen, unisulcate; posterior valve retuse, radially sulcate behind ; central areas of the intermediate valves irregularly sulcate-scabrous ; margin smooth. Length '6, breadth -3 inch. (Sowb.*) St. Elena and Panama. 268 CALLISTOCHITON. Chiton elenensis SOWERBY, P. Z. S. 1832, p. 27.— C. ellinensis SOWB., Conchol. Illustr., p. 6, f. 69. — Ischnochiton elenensis CPR., P. Z. S. 1865, p. 275. — Probably Chiton janeirensis var.f GRAY,Spicil. Zool., not of Sowerby and Reeve. Sowerby's original description and figures given above. I have not seen this species, and place it in Callistochiton with some doubt, as its internal characters may demand for it a position in Ischno- chiton. Haddon considers it very closely allied to C. deeoratus Cpr. Carpenter has identified with this species a Panama form collected by Prof. C. B. Adams. He gives the following description of it : "Outside having the central areas decussated with about 20 parallel bars ; lateral areas having two strong, swollen, tuberculose ribs. Interior having the sutural [posterior] margin reflexed, tuberculate, with a small sinus ; insertion plates 1-slit, sinus 'very broad. Front valve having 12 ribs, not very strong, and ten slits within, the teeth acute, eaves narrow. Posterior valve having the mucro subposterior, depressed ; the slope behind it expanded, con- cave, with about 12 subobsolete ribs; inside with 9 slits, the teeth short, eaves small, callous within. The central valves of this species are normal ; but the posterior valve offers a transition toward Callo- chiton L=Callistochiton], the outside being concave posteriorly, the insertion-teeth short, and the eaves callous. (Cpr. in P. Z. S.). The sinus is unusually broad and shallow, the sutural laminse not being marked off. (Cpr.) C. EXPRESSUS Carpenter. Unfigured. Shell similar to /. elenensis, but flesh-colored. Central areas hav- ing 10 distant closely decussated bars ; dorsal ridge acute, lateral areas having two very strong, narrow ribs with narrow tubercles ; inside having the posterior margin flat, hardly tuberculose, hardly si mi a ted ; sinus narrow, angulated at the jugum. Anterior valve having 10 strong, narrow ribs; interior as in elenensis, but with 8 slits. Posterior valve having a flat posterior mucro, the slope behind expanded, hardly concave, with about 7 very strong ribs; inside having about 7 slits, the eaves flat. " With a strong general resemblance to /. e/> //' //x/x, the differences in detail in the only two specimens examined, as above stated, appear of specific importance. If only varietal, it is equally impor- tant to notice how much change is tolerated by the habits of the animal. It may be the shell called Cliilan <-?at /trains by Professor 269 Adams, of whieh there were no duplicates to compare. Jt offers a still more marked transition to (<•/, Iton, the mar-jin of the pos- terior valve l.eiiiLr somewhat pectinated by the great projection of the ribs. (Q>r.) rnnama (C. B. Ad.) Ischnochiton (? yar.) expressus CPR., P. Z. S. 1865, j>. 'J7">. This species, like the last, is not known to me by specimens, the above description and notes being from Carpenter's paper in the P. Z. S. In his MSS. Carpenter places it in the smooth scaled section of Inch noch Unit, and gives some additional notes, as follows: "This shell is almost exactly like the young of /. serratus, agreeing not only in the peculiar and beautiful sculpture, but even in the mantle scales. Yet it differs remarkably in the abnormal, narrow pointed sinus, in which respect it resembles J. tectiformis. One of these species is probably the C. clathratus of C. B. Ad. (Pan. shells, p. 242), and possibly of Reeve." C. DECORATUS Carpenter, n. sp. PI. 58, figs. 17-20. Shell oblong, moderately convex, obtusely subangular along the dorsal ridge, the side-slopes slightly convex. Surface rather shining, varying in color from olive-buff to dark green, uniform or having darker flammules and spots. Apices of the median valves eroded. Lateral areas raised, each rendered bicostate by a central sylcus, and having a few uneven longitudinal impressed grooves, giving it a terraced aspect. Central areas having numerous parallel longitudinal ribs, the intervals closely latticed across, this sculpture obsolete on the ridge, where there is a broad V-shaped smooth area, which rarely shows a few diverging subobsolete ribs. Anterior valve having 11 rounded ribs. Posterior valve less elevated than the anterior, highest at the front margin, the mucro depressed, post-median ; posterior area having 9-10 rounded ribs. Interior bluish, generally marked with olive or green at jugum, bases of the sutural-plates, and slit- rays. Sutural plates wide, separated by a square sinus notched at each side. Anterior valve having 9 or 11, central 1, posterior valve 9-12 slits ; teeth rather sharp, smooth ; slit-rays distinct and porous. Eaves narrow. Girdle narrow, ashy-brown, covered with minute, striated, closely imbricating scales. Length 20, breadth 9-10 mill. ; divergence about 110°. Todos Santos Bay and near San Tomas River, Lower Calif orn in. 270 rAI.USTui HITON. CaUistochiton cfoeorofti* CPR., .I/NX. — Chiton (CaUistochiton) decor- ati(s Cpr., ORCUTT, Proc. U. S. Nat. Mus. viii, p. 544 (1885,) no description. It has been reported from San Diego by Orcutt and from La Paz by Carpenter (Pease coll.) The partially sculptured central areas are peculiar and character- i-tic-, and the tail valve presents features not found in the other species of the same region. The figures 17-20 may be regarded as the types, but some individuals show some very obsolete coarse ribs in the front part of thejugal smooth tract. The type is in the collection of the Academy. C. GABBI Pilsbry, n. sp. PL 60, figs. 7-10. Shell oblong, convex, rather sharply carinated, the side-slopes somewhat convex. Surface lusterless, the central areas light brown, lateral areas olivaceous-brown. Median valves not beaked ; lateral areas composed of two strongly elevated ribs, bearing acute grains, the posterior rib wider, having an additional row of smaller grains along the sutural margin ; the suleus between the ribs rather wide, minutely pitted. Central areas having about 15 parallel longitudinal riblets, becoming diverging toward the outer margins, the interstices very closely, sharply cross- latticed ; region of the beaks smoother, pitted and microscopically granulate. Anterior valve having 9 strongly elevated ribs separated by pitted intervals of the same width as the ribs, the latter bearing acute grains; the posterior rib on each side wider, with sutural grains ; region of the beak excavated. Posterior valve elevated at the front edge, rapidly sloping backward, the mucro about c> iitral, much depressed; posterior area sculptured with 7 rather broad wave-like radiating ribs surmounted by acute grains. Interior light olivaceous, with dark markings under the beaks. Sutural plates well developed, separated by a narrow, angular, con- vex sinus. Anterior valve having 9, central 1, posterior valve 8 slits ; teeth rather short, smooth, festooned and slit at the ribs. L expect r,,ral ridire of each valve. The (\ of S..\vrrl»y, a species which I have not seen, seems to be similar, bat judging from Sowerl>y'> figure the nuiero of that species projects at the summit of the posterior slope, which is far from bring the case with the form before me. The form described as elenensis by Carpenter differs in having a very wide sinus, weaker sculpture, etc. It should be compared with Carpenter's untiguivd Inchnochiton expressns, a species not known to me autopt- ically. The type is in the collection of the Academy. C, ITU IIKLLUS Gray. PI. 60, figs. 1-6. Shell oblong, rather depressed, the dorsal ridge subangular, side- slopes convex. Of a soiled buff color, the girdle darker, ashen. Valves not beaked ; lateral areas raised, cut by a sulcus into two prominent ribs, of which the posterior is wider, sculptured with low, transversely elongated grains, serrating the sutures, the anterior rib having less conspicuous grains. Central areas in the middle pitted in diagonal series, the pattern becoming coarser on each side, then changing into longitudinal fine riblets on the outer half of each side. Anterior valve having 10 (or 12) strong rounded ribs, cut into low transverse grains by superficial concentric impressed lines. Posterior valve abruptly depressed at the mucro, which is behind the middle, the forward area level, reticulated, the posterior area bearing 7 stout ribs ; the posterior ones are strongly bent. Interior whitish ; sutural-plates rounded, separated by a wide sinus, which is angular but hardly notched at the sides, and not per- ceptibly laminate. Slits in head-valve 10, median valves 1, poste- rior valve about 14 ; teeth thin but normal in front and median, irregular in the posterior valve. Eaves narrow. Girdle narrow, densely imbricated ivith minute smooth, flattened scales. Length 10, breadth 5 mill.; divergence 135°. Arica, Chili (Hennah.) Chiton pulchellus GRAY, Spicilegia Zoologica, pt. 1, p. 6, t. 3, f. 9, (July 1, 1828).— REEVE, Conch. Icon., t. 23, f. 153 (? and perhaps t. 25, f. 168).— Chiton (Callochiton) pulclicllus MORCH, Mai. Blat. vii, p. 176. — C. bicoxtatus D'ORBIGNY, Voy. dans 1'Amer., Merid., p. 486, t. 81, figs. 7-9. L' , _' CALLISTOCHITON. ? Chiton pulchellus C. B. AD., Cat. Panama Sh., p. 243 (in part). — " Chiton pulchellus " CPR., P. Z. S. 1865, p. llS.— Callistochitnn pukhri&r CPR., J/N£ Not Callistochiton pulchellus of Carpenter's M8S. — Not Chiton. l>\ilchellus of d'Orbigny, Voy. dans l'Ame*r. Me*rid., p. 489. The netted sculpture of the dorsal areas is unlike other species from the western coasts of the Americas. Figures 3-6, drawn by the author, should enable any one to identify the species readily. The small size is also rather characteristic, as well as the profile of the posterior valve (fig. 5.) I have but little doubt of the identity of Carpenter's C. pulchrior (=0. pulchellus Cpr., P. Z. S. 1865, p. 276) with the true C. rl,,!In8 of Gray. Carpenter separated pulchrior from after studying specimens supposed to be of the latter species sent him by Cuming ; but it is clear to me that Cuming's identification was erroneous, and therefore the position taken by Carpenter becomes untenable. Drawings of the form called pulchrior, prepared for Carpenter, are reproduced on my plate 59, figs. 21-26. The sculpture is not well rendered, and if the drawing is accurate, the tail-plate differs somewhat in profile. Gray's description of pulchellus is not as good as Reeve's and his figure (pi. 60, fig. 1) is poor. The detail figure given by Reeve is copied on pi. 60, fig. 2. Gray's description is as follows : Shell oblong, ^elongate, slightly keeled, yellowish-white. End valves distantly, unequally, radiately ribbed; lateral areas of the middle valves with two broad, regular ribs ; central area closely and deeply punctured. Margin yellowish- white, with very minute bran-like scales. The ribs of the lateral areas are rarely bifid. Length 3, breadth i of an inch. [=about 9x4 mill.] Inhab. Arica, Peru, Rev. W. Hennah, Brit. Mus. (Gray.) The species described from Arica by d'Orbigny is in all pro It- ability the same as Gray's form, but the figures are very poor. The original description is here translated : C. bicostatu* d'Orbigny. (PI. 59, figs. 43, 44). Shell oblong, swollen and obtuse, entirely whitish. Anterior and posterior valves sculptured with broad, radiating ribs and some concentric lines of growth. Lateral areas of the intermediate valves each ornamented ( \i i WTO in •with tWO very larirr, prominent ribs ; median ide and punctate. Girdle minutely scaly. Len^-tli 7 mill. (0 Arirn, under stones at l«»w \v;r \lliedt" r. inilrlicf/im of < iray, ditli-rmi: in tin- irranulous and scaly, not smooth, Lrmlle, 1>\ the two ribs ..i'the lateral areas instead of three, and hy the punctate central areas, which in the other species are striated." (Orb.) It must l>e remembered that the " C. pulchellus of Gray" alluded to hy Orhiirny, is not tin- true jutlchellus of Gray, but some totally ditieivnt species of Chcetopleura or of Tonic!". ( '. -in ri i. I:\VOKTHIANUS Pilsbry, n. sp. PL 21, figs. 42, 43, 44, 4-">, 4U. Shell oval, depressed but dorsally carinated, the side-slopes nearly straight; lateral areas strongly raised, bicostate, the ribs nodose; central areas having a coarse raised net-work in the middle, and longitudinally ribbed toward the sides. Girdle broad. Color of both xliell ami yirdle intense orange yellow. The lateral areas bear two strong ribs which bear stout transverse tubercles, the intervening spaces being closely granulate. The central areas have coarse wi-likc sculpture (fig. 45), which becomes much finer toward the beaks, and is transformed into a longitudinal cos- tulation at the sides. The front valve has 16 or 17 strong, tuberculate radiating ribs, the whole covered by a fine granulation. The poste- •"/?•' />• Depressed, having a rather low but acute and slightly pos- terior mucro, the slope back of it being concave. It is sculptured similar to the head-valve, except that the concentric sculpture pre- dominates over the radiating. The interior is flesh-colored; anterior valve with 10, central 1 slit; sutural plates low and rounded ; sinus shallow, flat. Girdle wide, compact, very densely clothed with closely imbricat- ing scales, the terminations of which are not striated, although the basal portions are distinctly grooved (pi. 21, fig. 46.) Length 14, breadth 9 mill. Key West, Fl»ri This species has the same style of honey-comb or netted sculpture toward the beaks that C. pnlchellus and C. shuttleworihianus show. A specimen in which the number of ribs on the head valve is increased by splitting to 17, and on the tail valve to 16 is on record; < LLLWTCX m bat the number in front Ifl ordinarily from into 1'J, In-hind from -8 to ]-. The tail valve is much depre— ed, as in (\ tjnl>hi. Carpenter deseril>ed a Iarir<-, line speeimen as ( . Mreophagut, hut upon examining Ueeve's type he concluded that it was merely a well developed f//i//////i/x. Tlie type is in the Uritish Museum. C. coiM-iN<;i;i:i Smith. PI. o<>, fig. 36. Shell elongate, greenish-white, stained with a dark green color alonir each side near the girdle, with a paler indistinct stripe on each side of the central line, the apex of the valves heing somewhat livid. Central valves with a straight posterior margin, arched, with only the faintest indication of a carina at the vertex. Lateral areas somewhat raised, with two radiating rows of coarse transverse rugse, of which the hinder or marginal are the largest. The surface between them is finely granular. Central areas covered with a more or less criss-cross granulation, the granules at the center being very minute, and gradually increasing in size toward the sides, where there is very little of the criss-cross arrangement seen at the vertex, but rather a longitudinal disposition of them. The front valve is minutely granulated and has about twenty fine radiating ridges, here and there some of them bifurcating near the circum- ference. Posterior valve rather large, concave behind the sub- central mucro, in front of which the surface is sculptured in the same manner as the front of the central valves, as is usual with most, if not all Chitons. The posterior half is finely grained and sparsely covered with pustules of different shapes and sizes. The coarsest being near the margin and the smallest near the center. The iusertioual plates are thin, with twelve slits in the last, at unequal distances, eleven in the front one, and one on each side of the intermediate valves. The interior is pale bluish, the latter valves having an olive- brown stain radiating from the vertex behind on each side, and the two terminal valves have marks of the same color near the middle. The girdle is covered with alternately pinkish and dark grayish patches of fine oval compressed imbricating scales, of which those toward the outer margin are much smaller than those near the valves. Length without girdle 21 millim. ; diameter of fifth central plate 8 mill. (Smith.') Port Jackson, Australia (Coppinger.) Chiton (Callistochitoii) coppinyeri E. A. SMITH, Rep. Zool. Coll. H. M. S. 'Alert,' p. 80, t. 6, f. E (1884.) 276 CALLISTOCHITON. The only published figure of this species is very poor. Smith writes : closely allied to C. antiguus, but it is differently and more finely sculptured, and the scales on the mantle are larger. The type is in the British Museum. C. ADENENSIS Smith. PI. 59, fig. 45. Shell small, depressed, hardly carinated, unicolored pale brown- ish. Anterior valve having about 22 granulate radiating ribs. Lateral areas composed of two strong granulate ribs ; central areas longitudinally granose-lirate, the lirse more delicate in the middle than at the sides. Posterior valve having about 25 delicate granulate lirce. Girdle pale brownish, very minutely scaly. Length 14, breadth 9£ mill. (Smith.') Aden. Chiton (Callistochitoii) adenensis E. A. SMITH, Proc. Zool. Soc. Lond. 1891, p. 421, t. 33, f. 7. The sculpture of this species is of the same character as that of C. antiguus Reeve, but not quite so pronounced, and the rays of both the terminal valves are more numerous. (Smith.) The type is in the British Museum. The italics of the above description are my own. C. HETERODON Pilsbry, n. sp. PI. 60, figs. 11-15. Shell oblong, rather elevated, carinated, the side-slopes nearly straight; buff- white, sparsely dotted on the ridge with olive-black and having one or two spots of the same on the sides of each valve ; the girdle yellowish, having narrow slate-colored bars. Valves having rather acute but not backward-projecting beaks. Lateral areas raised, having 3 or 4 ribs, being primarily divided by a deep sulcus into two ribs, the posterior of which is again divided ; and sometimes the front rib also is split into two, especially on the second valve ; the interstices are coarsely pitted, and the posterior rib is ribbed across, dentating the sutures. The central areas have about 11 rather narrow but strong longitudinal riblets on each side of a wider dorsal rib ; the interstices nearly smooth. Head valve having 11 (or 13, by splitting) strong denticulate ribs. Tail valve narrower than the head-valve, not depressed, the mucro obtuse, post median ; posterior slope convex, having 11 radiating ribs. Interior pure white. Sutural plates narrow, separated by a square, slightly deticulate sinus, which is distinctly laminate and slightly notched at the corners. Anterior valve having 8, central valves 1, NUTTAI.MNA. 277 posterior valve 13 slits ; teHh blunt, finely and deeply pectinated out- side and at the edge. Eaves solid. < Girdle broad, compactly covered with shining, deeply sulcated scales, measuring about one-third of ;i mi Him. in breadth, and the terminal margin of each is smooth (fig. 13.) Length about 16, breadth 10 mill. ; divergence about 105°. Red Sea. This species has far fewer ribs on the terminal valves than C. adenensis Smith, although the lateral areas have more ribs. The girdle scales are coarser than in other species, and they have the peculiarity noted in C. shuttleworthianus, of being smooth at the distal end. I have seen no Chitons of other genera having this feature. The second valve has several slightly diverging riblets at the front of the dorsal area. The teeth are as deeply pectinated as in any species of typical Chiton or Acanthopleura ; and it is by no means impossible that the species belongs to the former genus. I have preferred to retain it in Callistochiton on account of the peculiar sculpture, and the relation in which the slits stand to the ribs. The type is in the collection of the Academy. Var. SAVIGNYI Pilsbry. PL 60, fig. 16. This form is known to me by Savigny's figures, which indicate a species closely resembling the last. The head valve has 11, the lateral areas two ribs ; the tail valve is smaller, having 9 ribs ; central areas with about 9 ribs on each side, and a rather wide smooth tract in the middle. Scales of the girdle sulcate, with .smooth outer edges. SAVIGNY, Descript. de FAegypte, Gasterop., t. 3, f. 8-1, 8-2, 8'3. Genus XXIV. NUTTALLINA Carpenter, 1879. =Nuttallina plus Middendorfia plus Beanella Cpr. Valves exposed, granulated, the lateral areas having 2, head yalve numerous low radiating ribs ; insertion-plates sharp, the slits corresponding in position to external ribs* Mucro behind the middle, the posterior teeth directed forward. Eaves and sinus very spongy. Girdle varying from spiny to scaly. This well-defined genus probably has the same apparently anomalous distribution as the coral-red Leptothyras ; species being found in the Mediterranean, the Japanese Seas, and the coast of Cali- 278 Nl-TTAI.l.INA. i'oniia. Xuttallina is divisible into two closely allied sections or sub- genera, as follow- : Siihuvniis Xn I'M. i. IN A .*. str. Side-slits two in each valve, the pos- terior one generally subobsolete, but indicated by a porous slit- ray. Teeth hardly or not thickened at the edges of the >lits ; girdle wnh minute, often chaffy spinelets and longer round spines. Sul .genus MIDDENDORFFIA Cpr. Side-slits single. Teeth more or -- thickened at the edges; girdle clothed with minute striated flattened scales and having a marginal row of flat striated bristles. Subgenus NUTVALLIXA Carpenter (restricted.) Xiitt'illina CPR., Table of Reg. Chitons, 1873.— DALL, (Amer. Journ. Conch, vii, p. 134), Proc. U. S. Nat. Mus. 1878, p. 333 (Feb. 14, 1879.) Valves exposed, granulated, having long smooth sharp teeth ; the slits of the median valves obsoletely doubled, 'those of the anterior valve corresponding in position to the external ribs, the teeth not thickened at the edges of the slits; mucro of posterior valve poste- rior, terminal but not marginal; teeth of posterior valve short, chisel-shaped, directed forward. Eaves and sinus spongy. Girdle bearing short, rigid spines. Gills extending the whole length of the foot. Type X. scabra Cpr.= CA. californiciis (Nutt.) Rve. The shell in this genus resembles that of typical Acanthophnrn (A. spinosa Brug.) in the elongated valves, double slitting of the median valves, and the spinose girdle. It differs in the smoothness of the sharp teeth and the spongy sinus, — characters of much greater importance than those first enumerated. The likeness of Nuttallina to Acanthopleura is, in fact, merely one of analogy, having no mean- ing deeper than that story of the development of different stocks along parallel lines, repeated so often in the history of Chitons. In its fundamental characters, Nuttallina agrees with Ceratozona ; but the more shelly texture of the girdle-spines, the spongy sinus, and propless teeth afford sufficient ground for generic distinction. Authors and collectors have gnu-rally recognized but one Cali- fornia species ; but there seem to be two. It is useless to try to .-tudy thnn without separating the valve?, as the specific characters are not very apparent in specimens preserved in the ordinary manner. 279 Tin- white -piiM-- are oftm ^trialed when JOUllg, as are the scale- •///•/. N.CAI ii /' "/•'/ nl>rn On., MS. and of BALL, Amer. Journ. Conch, vii, p. 184; Proc. U. S. Nat. Mus. 1878, p. 333.— AcauthofL-ura scabra OK., Ilrit. Asso. 1863, p. 649.— STEARNS, Proc. Calif. Acad. iii, p. 346.— Nutt'ill',,,,,., Mdbra Kr.r.r. West Coast Shells, p. 108, f. 96 (1887.) Not Chiton scnber Reeve. This is the form which has generally been called "JV. scabra." Reeve's figure is not good, being drawn from a short specimen abnormally shortened by contraction. It should be noted that the shortest specimen in the large suite before me is also one of those collected by Nut tall, who presented a complete set of iiis Califor- nian shells to the Academy. In this species the individual valves are longer than in the follow- ing form, but on account of their deep imbrication the difference is not in most cases noticeable until the shell is dissected. The girdle is much more densely clothed with spinelets. The areas of distribution seem to be separated, the true californica extending southward past Monterey Bay, — the southern out-post of so many species of the Columbian district, — to near S. Simeon, S. Luis Obispo Co. The other species, scabra, has not been noticed north of Sta. Barbara Island, and San Diego on the mainland. There is still a considerable stretch of coast from which we have no record, or at least no record in which the two forms are discrimin- ated. This coast should be searched for intermediate forms. Dall gives the following notes on the station of this form : This r-iniriilar species (not yet obtained from Alaska, but which will prob- ably be found there), like some Lilorinas, seems habitually to prefer positions where it can at most be reached by the spray in stornis, on -ed headlands, where the breeze comes in damp and cool from the sea. The pointed valves overlap each other so much that when the creature is curled up they project from the girdle, giving a pect- inated outline, unusual in Chitons. The valves are almost always eroded, even the prominent mucro is often hollowed out, and the sculpture can rarely be seen except in young specimens. The color i.- irrayMi «>r l>n>wni.-h. with whitish streaks; the girdle has the aspect of dead brownish-black moss, sometimes with ashy spots at the sutures. N. SCABRA Reeve. I 'I. :> J, figs. 21, 22 ; plate 56, figs. 19, 20. Shell similar to N. californiea, but having the individual valves much shorter in proportion to their width : the outer layer of the median valves produced at the sides anteriorly, curving broadly M i i \ i i 281 forward and literally Upon thfl sutural plat<--; flu- medi;m i and sulci inoiv or • !••. 'I ail valve -li'Ti.r, with less pos- terior macro, Oolor of yalvei li.irht vaiir-at.'d. Girdle rusty brown or alternately blacki-h and white ; rather spar-ely scattered white sj)ik«--lik<- -j.i • one or two at each suture. PI. ">J, fig. 21). length :>!», breadth L3 mill. Santa Barbara Is. ami XHH I>i»/()to between Soo/mn rn i'l . Chiton scaber h'u.vi:. Conch. Icon., t. 17, f. 106 (March, 1847).— Acanthopleura fluxa CPR., Suppl. Rep. Brit. Asso. 1863, p. 649; Proc. Cal. Acad. iii, {>. 211, (1865.) This species has hitherto been confused with the preceding by most collectors. Carpenter, however, distinguished it, and gave the name fliu-n. Although the individual valves are much shorter in this species than in N. californica, they overlap much less, so that the total length of the animal is about the same in the two species. The elevation is about equal also, but in californica the girdle is generally wider at the sides, especially in old specimens. In size, individuals of the northern species considerably exceed any of the southern I have seen, although the majority of specimens do not differ much. • N. ALTERNATA Sowerbj. PL 54, figs. 25, 26, 27. Shell elongated, subdepressed, very minutely granulated ; lightly keeled by a central rib ; lateral areas separated by a lateral rib. Anterior valve radiately ribbed ; posterior valve small. Girdle furnished with minute spines, alternately banded black and white. Length 15, breadth 8£ mill. Narrow, rather flat, minutely granulated; the first valve radiated •with slightly raised ribs, the intermediate have each three faint ribs, one dorsal, the other two lateral ; the la>t U very small, with a nearly terminal apex. The margin is covered with very minute spines, in alternate patches of black and white; general color, dark olive-green. (Sowb.) (Mus. ( 'inning). Chiton alternatus Sown., Mair. of Nat. Hist., IMn, p. 288 ; Conch. Illustr., f. 141. 282 \ I.I.I N A. This form has not been noticed by subsequent authors. It seems- to agree with the preceding species in the dorsal and lateral ribs, and also those upon the anterior valve ; but as the interior is unknown, its reference to Xntt., 1881, pp. 284, 287, type Chiton polii Phil, non Desh., (Jan. 20, 1882.) — Dawsonia CPR. 1873, preoc., same type. — Beania CPR. 3/5., not of Johnstone. — Beanella DALL, Proc. U. S. Nat. Mus. 1881, pp. 284, 287, type C.pseudorissoi CPR. ined., in Mus. Cuming no. 51. Valves exposed, rather square and short, granose outside with low ribs at lateral areas and on head- valve. Insertion plates rather sharp, not notably rugose, the teeth more or less thickened outside at the slit-edges; slits of head-valve corresponding in position to exter- nal ribs. Tail valve small with mucro behind the center, the teeth directed forward, eaves and sinus coarsely spongy. Girdle narrow, compactly covered with a pavement of minute striated scales and spinose at the edge. Gills extending forward over three-fourths the length of the foot. Type Ch. cinerem Poli, not Linn. This subgenus agrees with Nnttallina in the markedly porous or spongy texture of eaves and sinus, in the external sculpture, and in the forms of the insertion-teeth, except that in Middendvrffia these are thickened at the slit-edges. It differs from Nuttallina in the rather flattened scale-like, rather than spine-like girdle appendages but the younger spines of Nutallina scabra, when examined under a strong power are often seen to be striated, appearing like finely fluted ivory pillars ; and in some specimens of the same species there is a marked tendency to form a marginal fringe of longer spines. The differences between the West American and Med- iterranean forms are therefore not great, being confined to (a) the irinlle covering, which often varies as much in closely allied species, such as ItehnockUon r,tn*i>'n-im* and /.m-rior, or Chatopleuraperwri- l, ndorffia and fails as a generic charac- ter in Ceratozona and some other groups. It should be noted that in Middendorffia the true structure and especially the sculpturing of the girdle-scales often cannot be satis- factorily observed without a compound mici . nd a magnifi- cation of Iron i ."in to MM) diain«'trr- is neC€80ary to deHMMIttntfl it iii many N.CMVI :i:i :\ IMi. IM. 54, flg& 20 Shell oval, moderately elevated, not earinated, tin- ^ide slope* straight. Surtaee lii>t»-rl«s<, ur«'ii. -rally enerusted with ealrareous IT n> wths, gray or greenish blotched with Mack or dark green uitli some liirht marking or liirlit va! The median valves arc beaked when young, but eroded and hardly beaked when adult, the lateral i Itiftwo/inr iride rounded r/Ax with a shallow depression between them ; one rib diagonal, the other at the posterior border. Entire surface of all valves rrenh/ n>r> rcif> (ai in Kudoxochiton, p. 193.) Interior bluish in the middle, olive-greenish at the sides. $•' rather deep and amju/nr, t'trif jinnm* »/• .-•/"' ".'///• A more or less distinct laminate triangle extending from sinus to beak. Anterior valve having 8 or 9 slits corresponding in position to the external ribs ; the slits are very short, but are continued as grooves to the eaves outside ; median valves with 1 slit ; the anterior teeth nearly smooth, distinctly thickened or " propped" outside at the slits; pos- terior valve having slits, the teeth rather stumpy, short in the mid- dle behindj longer and directed forward at the sides. Eaves rather wide and coarsely spongy. Girdle narrow, alternately dark and light, compactly covered with small, subcircular or irregularly polygonal scales, striated on the convex outer surface, crowded together; the margin beset with a series of slightly flattened, striated translucent bristles, (figs. 31, 33). Length 14, breadth 8 mill. Length 20, breadth 12 mill. Entire Mediterranean and Adriatic Seas; Atlantic Ocean at Cadiz, Spain. Littoral zone. Chiton i-'niereus (+ Lophi/rn.^ nnlphlctensis) POLI, Test. utr. Sicil. i, multivalvia p. 4, t. ?>, f. 1-20, (1791). Not C. eta Linn. — C. capreann SCACCHI, Cat. Conch. Regni Neapolitan!, p. 9 (1836) teste Monts. — C. caprearum Scac., BUG., DAUTZ. and DOI.I.- FUS, Moll. Mar. Rouss. i, p. 492, t. 61, f. 7-9 ; t. 62, f. 1 (1886).— 284 NUTTAI.I.INA. Ch. polii PHIUI-IM, Knuni. Moll. Sicil. i, p. 106 (1836); ii, p. 83 (1844), and of most subsequent authors ; not Ch. polii Desh. 1832. — Ch. crenulatus LOCARD, Coq. Mar. des Cotes de France, p. 233. (1892), and perhaps C.erenulatusHiaQ Ear. Mend. p. 267. — Chiton TII-.KRI, Bull. Soc. Mai. Ital. iii, p. 141 (1877).— Chiton " Ki i :\ i: Conch. Icon., t. 28, f. 185 (1848). Distinguished from other Mediterranean species by the finely granose- scaly sculpture covering the entire surface, with two low ribs at the lateral areas and 8 or 9 on the head-valve. The girdle is composed of short striated scales crowded together, producing a " cobble-stone pavement " surface. The true nature of the scales appears only when highly magnified. The nomenclature of the species is peculiarly involved, like that of most Mediterranean Chi- tons. Poli believed it to be the cinereus of Linnaeus, but Philippi dis- tinguished it from that and gave the name Polii, which unfor- tunately had been some years before bestowed by Deshayes upon another species. Monterosato claims to have identified it with Ch. eapreftrum (" caprearm ") of Scacchi, by examination of a type in the Petit collection ; but the description given by Scacchi is inadequate. Scacchi says : " Chiton caprearm [sic] Nobis. Clypeis 8 tuberculatis virescentibus, fascia marginali squamoso~muri<-'if upward wave posteriorly. Girdle coriaceous (or perhaps better, pithy) and almost smooth. Length LSI, hivadth Hi mill. Calapan, Island of Mindoro, Philippines, in coarse sand among small stones, in 9 fms. (Guming.) Chiton laqueatus Sows., P. Z. S. 1841, p. 104.— REEVE, Conch. Icon., t. 20, f. 135. The above description is mainly compiled from details furnished by Mr. E. A. Smith of the British Museum, who also drew figures 42 -51 from one of the original specimens. The scale-like granules are said to be represented somewhat too small on the figures. Sowerby remarks that the four or five central valves in several specimens are nearly covered by a dark purple color, the two last patched with green, and the first nearly white, but subject to some variations. Slmttlcuorth describes the girdle " limbus corneus, minuti atperulus," but Smith says it is nearly smooth in the British Museum specimens, and the insertion plates are visible through it, as shown in fig. 42. Genus XXVI. A XGASIA Carpenter, 1882. Angasia CPR., Table Reg. Chitons 1873 ; and in DALL, Proc. U. S. Nat. MusM 1881, p. 283, 286, 289, 290 (Jan. 20, 1882).— Augasia SCUDDER, Nomencl. Zool. p. 38 (typog. err). Valves outwardly and within like those of Chwtopleura, but the eaves small ; girdle minutely scaly-pilose, and furnished with tufts of hairs at the sutures. Type A. tdrica Cpr. I have seen no specimen of this form, which I believe to be related to Oraspedochiton, Carpenter writes as follo\\ 287 "This genus difieif from c- in having the eaves nl. the ttvth straight 'th-Hi-h i'iv.|nent ly |.n.|.prd oiit.-id.', a- in f ». the mantle en.udrd with minute Imni; and furnished wit 1. lichen round tin- -utiir<-<. anterior valves is 5 slit, M in Aruntli"i-i,;t,--, hut that may be only a specific peculiarity. The 7A///A//./ variabiKt Ad. and Am'. I'. /.. 9 1-SI''I. p. 1!M, pn.hably belongs to this genus hut ha- not been dissected. Angasia is known at once from Hanlwja by the presence of insertion teeth ; and from /'/,/,-/'/, /io/v/ hythe regular articular i-.n of the tail plate. If the genera be grouped according to the raanth- poivs Ant/'i*I'i will n-pn-sont Chatto/,/*,!,-,/ in the tufted series, as Callistoplax represents (.'/,-*//v<. The posterior valve somewhat reseml>lrs an irregular M '•/ : the1 anterior valve is strictly Acanthochi- toid. Both of tlu-se an- flatt< m-d, while the ridge is sharp on the .il valves. (Cpr.) Yar. < AI.CULOSA Cpr. Shell externally very similar to . 1 . tetrica, but roseate ; jugal areas distinctly tricostate ; anterior valve distinctly five-angled; pebble- sculpture smoother. Interior: posterior valve normal, with 5 slits, t la- teeth all acute, but slightly roughened, hardly propped; sinus narrow, deep, smooth, flat. Bunches of spicules minute, inconspic- uous (Cpr.) J'/ti/ijijtitte* (Mus. Cuming no. 79, part.) An(/'i.«in (/ tetrica war.') <-nl<-ul<>sa CPR., MS. " The insertion plates of this shell offer a marked contrast to the Cingalese shell, being strictly like Ischnochiton (with shortened eaves) throughout. But one specimen, after an anterior fracture, has mended it with distinctly rugulose teeth, and made its posterior teeth propped and lobed, showing a close connexion between the tw<> forms. It is probable that Mr. Cuming''s specimens from the two localities had been intermixed. The tufts could scarcely be detected in shriveled specimens " (Cpr.} Genus X XVII. CALLISTOPLAX Carpenter, 1882. CPR., Table of Regular Chitons, 1873. — Dall, Proc. U. S. Nat. Mus. 1881, p. 283, 286 (Jan. 20, 1882).— TRYOX, Struct. and Syst. Conch, ii, p. 342. Valves outwardly and within as in Callistochiton. Girdle naked except for a series of bristle-bearing pores. The present genus is one of the very few which rest entirely upon characters of the girdle ; but so different is this from that of Callis- tnchiion. not only in the presence of pores, but in the entire absence of scales, that no course seems open but to treat the group as of generic value. C. RETUSUS Sowerl>y. PI. fll, figs. 17-26. Shell small, subeloniraU , -lightly elevated, the jugum acute; mucro median, vory obtuse, elevated in adult specimens. Jugal area smoothish, granulose, in the adult having a few acute longitu- CAM BTOPLAJL '2*'.l dinal linihe; central areas with about ID nigulo8e-gr:uio~e lit each side, perpendicular to tin- diagonal line, the iut«-i--tic»-.- »-IIH-»-|- lated. Lateral areas havini; two very strong rounded riln, the front one stronger, separated by a narrow sulc.us, and concentrically Wrinkle-graHOSe and very minutely ^ranulose; sutures \\ith a series of imbricating granules. Anterior valve having 7 ribs, of which the posterior ones (as in the median valves), bifurcate, and are imbricated along the sutures; posterior valve in the young shell having (I ribs, all of these bifurcate, and the anterior ones split twice, making 14 delicate, flattened ribs, which tend forward s what Interior: the posterior valve, in a young specimen has about 11 slits, the teeth curved in harmony with the external ribs, and directed radially outward ; in the adult there are about 12 slits, the teeth solid, directed somewhat forward, rugose-costate at the mar- gins, concave in the middle, the eaves very heavily callous. Ante- rior valve having 7-8 slits, situated in the middle of the ribs, the teeth following the curvature of the outer margin, acute. Central valves with 1 slit, teeth excurved, eaves wide, pectinated, spongy. Sinus narrow, deep, narrowly slit on each side of the lamina, and sometimes denticulated by the external sculpture. Girdle narrow, smooth, thin, having 40-53 bunches of long, cor- neous hairs around the margin, hardly sutural (figs. 23, 24). Length 14*, breadth 8 mill.; divergence 120°. Guacomayo and Puerto Portrero (Cuming) ; China Seas (Cum- ing.) Chiton retmus SOWB. P. Z. 8. 1832, p. 28, Conch. Illustr. f. 22.— REEVE, Conch. Icon., t. 17, f. W.—Plaxiphora retusa H. & A. Ad. Genera Rec. Moll, i, p. 481. — Callistoplax retusa CPR. MS. and in Dall, Proc. U. S. Nat. Mus. 1881, p. 286. The locality " China Seas " given by Cuming to Carpenter, is probably wrong, that originally given by Sowerby being much more worthy of confidence. The above description is from Carpenter's MS. Figures 17-23 represent a young specimen ; in the adult the ribs become more numerous and the tail-plate more " Acanthoid " in appearance (figs. 25, 26). 19 290 CERATOZONA. Genus X X VIII. CERATOZONA Dall, 1882. Ceratopltnrus ('PR., Table of Regular Chitons, 1873, type C. iiuililinyi Rve. Not of Diesing, 1850. — Ceratozona DALL, Proc.U. 8, \;it. Mus. 1881, p. 283, 286 (Jan. 20, 1882).— Newcombia CPR., V\. type C.setosus Sowb. Not Neivcombia Pfr., Malak. Bl. i, p. 117. 1854. Valves strong, exposed. Insertion plates of anterior valve long, sharp, rugose outside, thickened at the slits, which correspond in position to the external ribs ; median valves with similar propped teeth ; tail valve having the teeth thick, shorter, rugose, sinus solid. Girdle tough, bearing peculiar corneous spines, similar in substance to itself, generally sparsely bunched, at the sutures. The gills extend the entire length of the foot. Type C. guildingi Reeve = C. rugosa Sowb. Shuttleworth may readily be excused for grouping the type of this genus in Chcetopleura. Compared with Ch. hennahi it is seen that both have the teeth sharp, and rugose outside ; both have the eaves solid or occasionally with a row of minute pores along the outer bases of the teeth ; and finally both have horny spinelets on the girdle. But in Ceratozona the insertion teeth are thickened at the slits which correspond in position to the riblets of the exterior ; the valves are much more firmly held in the tough girdle, and the appendages of the latter are much more deeply inserted in its sub- stance. If we examine an alcoholic example of Chcetopleura h> n/i'iJti we find that the cuticle of the girdle peels off readily, bringing with it all the spinelets, which leave shallow pits in the fleshy sub- stance of the girdle; but in Ceratozona, only the smaller hairs are thus readily removed, the larger ones being deeply and very intimately attached. Moreover, in most specimens, a pair, or a small bunch of spines, may be detected near each of the sutures ; but this character is often obscure or even wholly obsolete. From Nuttallina this group differs in the solidity of the sinus, the less pos- terior mucro, generally rugose and " propped " teeth, and the peculiar girdle-spines. C. RUGOSA Sowerby. PI. 61, figs. 33-37, 41-45. Shell oblong, rather convex, the back broadly arched. Surface generally much eroded, green, olive or slate-blackish on the sides, the central areas whitish along the middle, flamed with blackish at the sides, or green there; tail valve having a broad pink ray behind. 291 valves are strong, and when not eroded they are somewhat 'beaked. Lateral area- hardly raised, but defined !,y a Strong rounded rih, sometime- with a lower wide rib behind; having a sculpture of irregular wavy wrinkles over ribs and interval, and also upon the >ides of the cent nil area-. Head-valve having about 11 low radiating ribs and superlieially waved concentrically. Tail valve rather depre^ed with a siibcentral, slightly projecting mucro, the area behind it obsoletely radiated. Interior blue-green, varying in intensity. Sutural plates moder- ate, separated by a rather wide smooth sinus. Anterior valve having 7-10 slits, the teeth long, acute, slightly rugose outside and denticulate at the edge, generally thickened or propped very strongly along the slits ; central valves with 1 slit, the teeth much thickened at the edges of the slit ; posterior valve having 8-10 slits, the teeth much shorter and blunter than in front, wedge-shaped, denticulate at the edge, not perceptibly propped or thickened along the slits, Eaves very narrow, having a single series of pores along the bases of the teeth. Girdle very tenacious, rather wide, yellowish, armed with numer- ous corneous, yellow rather long and pointed spines, most numerous around the edge, and in most specimens showing a bunch of several at each suture ; among these larger spines, slender flexible beards are scattered (fig. 35). Length 40, breadth 25 mill. ; generally smaller. Jupiter Inlet, east coast of Florida (G. TV. Webster et a/.) to Jamaica (C. B. Ad., Johnson & Fox) ; Porto Rico (Blauner) ; St. Vincent and Trinidad (Guilding). Chiton rugosus (Gray) SOWERBY, Conchol. Illustr. no. 6, fig. 49, (1841 ?).— REEVE, Conch. Icon., t. 18, f. 115 (April 1847).— Chiton (Chcetopleura) rugosa Sowb, SHUTTL., Bern. Mittheil. 1853, p. 78. — Chiton squalidiis C. B. Ad., Proc. Bost. Soc. Nat. Hist., ii, p. 8, (Jan. 1845). — Chiton gulldlngii REEVE, Conch. Icon., t. 21, f. 138 (May, 1847). — Cera^hoi'us guildingi CPR. — Ceratozona guildingi BALL, Catal. Mar. Moll., S. E. U. S. p. 172.— Ch. bicolor (C. B. Ad.) GRAY, P. Z. S. 1847, p. 67. This species is not likely to be confused with any except the next. The valves are rather strong and blue-green inside, sometimes very pale. The girdle is of a conspicuous horny yellow color when scrubbed as in most cabinet specimens, but is dull and dark in the natural condition. The horny, curved bristles are both fine and 292 CERATOZONA. coarse, but the more delicate ones are easily lost. The pore-bunches at the sutures are rarely conspicuous, and often cannot be made out without the aid of a lens and a lively imagination ; and this fact somewhat impairs their value as a generic character. Nearly all of the adult specimens I have seen are very much eroded. Some recent authors have used the name guildingi Reeve, for this species ; it is not easy to see why, for Sowerby and Adams both preceded the author of the Iconica. The original figure of guildingi is copied on my plate, fig. 37. The sculpture varies a good deal. Fig. 36 is drawn from one of the most strongly sculptured speci- mens I have seen, from Jupiter Inlet, Fla. Fig. 34 is from Sta. Cruz., of the Virgin group, being drawn from a specimen colored exactly like Sowerby's original figure of rugosus (fig. 33). In this shell the teeth are less propped and the eaves narrower than in the Florida examples. Fig. 35 is from a Jamaica specimen. I have seen no specimen with the mucro so posterior as it is shown in Carpenter's figure (fig. 41) ; all I have seen resemble fig. 39. C. SETOSA Sowerby. PI. 61, figs. 40, 38, 39. Shell oblong-oval, ashy-greenish, scabrous; front valve, lateral areas and posterior valve radially sulcate. Marginal ligament setose, the setae rather short and close. Length 32$, breadth 15 mill. (Sowb). Ouacomayoy Central America (Cuming). Chiton setosus SOWB., P. Z. S. 1832, p. 27 ; Conch. Illustr. f. 19.— REEVE, Conch. Icon., f. 100. Not C. setosus Beechey's Voy. ' Blossom ' t. 41. f. 17,=Mopalia. Not Ch. setosus Tiles, Mem. Ac. S. Pet. ix, p. 484(1824). This species is very distinct from C. setiger King, which it in some degree resembles. The bristles around the edge are much shorter, thicker and more closely set. (Sowb). Carpenter has had figures of the interior and tail valve prepared, and I have copied them in my figs. 38, 39. I h#ve seen no species of this sort from the Pacific side of the isthmus, and I am therefore not prepared to say what relation setosa sustains toward rugo*a, the West Indian form. Fig. 40 is a copy of Sowerby's original figure of setosus. MOl'AMII) I . 293 Family MOI'AIJ II>. K I'ilsbry. (part • and .1/oy^/o/',/, ,, (part) C'l Chitons in which the valves are divided in tin- normal manner into lateral and central areas; the teeth of insertion are not pectina- ted ; and the posterior valve has a posterior-median sinus, with one slit on each side or none. The girdle is more or less hairy, never scaly. (Jill row as long as the foot. The normal number of slits in the anterior valve is 8 ; but this is often increased or diminished by splitting or fusion of one or two teeth. The slits correspond in position to external ribs, as in the last subfamily. In certain forms (Placiphorella, Placophoropsis) the number of anterior slits is abnormally multiplied. The inter- mediate and posterior valves have not more than 1 well developed slit on each side, and even this is lacking in the tail valve of Plaxi- phora. The girdle clings more tenaciously to the teeth than in most chitons, being like that of Ceratozona. It is frequently provided with pores at the sutures, each pore generally bearing two or several bristles or hairs ; but the presence or absence of these pores is in no case of more than specific value, and in some cases I have found it to be a mutable feature among individuals of the same species. The present family is in no manner identical with that so named by Dall, or with Carpenter's division of similar name ; nor is it in any sense equal to the Placophoridce of Dall, Placiphoroidea Cpr. These Carpenterian divisions of the " Irregular Chitons " are very artificial, just as the primary division of the group into " Regular" and " Irregular " forms is artificial. The ancestors of Mopaliidce were Callistoplacince, probably not very different from the recent genus Ceratozona. Key to the genera of Mopaliidce. a. Posterior valve having a slit on each side of the median sinus. b. Shell oblong ; girdle narrower in front than at the sides, its hairs smooth ; teeth of insertion not lobed. MOPALIA. bb. Shell rounded-oval ; girdle expanded and broadest in front, its hairs scaly ; teeth of insertion more or less lobed. PLACIPHORELLA. r tices, the riblets finer and converging on the ridge of the last 6 valves, diverging on the second valve, or strongly diverging on the ridge of all valves, like a series of superimposed v's. Anterior valves having about 10 narrow radiating granose riblets, the intervals granose. Tail valve depressed with posterior mucro, the posterior slope very short, emarginate behind. Interior bluish-green, stained with lilac on the central callus. Anterior valve having 8, median 1 short slit, the teeth long, deeply striated outside and thickened or propped outside at the sides of the slits. Posterior valve having a rounded sinus behind, with one oblique slit on each side, the plate roughened outside near the slits. Sutural plates broad, the sinus extremely shallow and small. Girdle rather narrow, densely covered with round, curved or curled hairs. Gill row as long as the foot (pi. 64, fig. 74). Length 52, breadth 38 mill. Length 25-60, breadth 15-40 mill. ; divergence 120°-140°. Shumagin Is. (rare) to San Diego, California, between tide marks and at lowest water. Ch. muscoms GLD., Proc. Bost. Soc. N. H. ii, p. 145, July, 1846 ; Exped. Moll., p. 313, f. 436 ; Otia, p. 6.— Chiton dliatus REEVE Conch. Icon., t. 19, f. 124. — Mopalia ciliata H. & A. AD. Gen. Rec. Moll., i, p. 478.— DALL, Proc. U. S. Nat. Mus., 1878, p. 303 (syn- onymy and variation) ; p. 298, f. 35, 35a (dentition). NOT Ch. ciliatus Sowerby ! — Chiton setosus Sows, in Beechey's Voy. ' Blos- som' p. 150, t. 41, f. 17 (not C. setotus Sowb. 1832).— Ch. collei REEVE, Conch. Icon., t. 21, f. 136 (1847). — Ch. wosnessen*kii MIDD. Mai. Ross, i, p. 101 (part of diagnosis). — Chiton nnnatua NUTT., JAY'S Catalogue, 1839, no. 2678 (not described) ; Ch. aren- atus NUTT., in Mus. Acad. Nat. Sci. Philadelphia. — C. ornatus NUTT. MS. CPR., P. Z. S. 1855, p. 232.— and C. consimilis NUTTALL, MS. in Brit. Mus. 296 MOPALIA. Iii its typical state (pi. 63, fig. 46), this species may lu- known by the stroug though variable sculpture, dull brown or blackish-olive color, the small sinus, the girdle being thickly set with round hairs varying from strong bristles to soft hairs. A variation in color is seen in some southern specimens (Tomales Bay) which are orange or scarlet (pi. 63, fig. 48), or yellowish maculated with orange and vermilion. Others from the same locality are vivid blue-green or green (pi. 63, fig. 47). In his work on the Chitons of Alaska, Dr. W. H. Dall discusses the synonymy and variation of this species, concluding that M. lignosa Gld. should be regarded as an extreme form, connected by intermediate examples with the typical muscosa. He writes as fol- lows: "This species can be distinguished from all varieties of wossnessenskli by its blackish and proportionately much narrower girdle, and by a sort of prolongation of the external layer of the shell forward under the apex of the next anterior valve in the median line, forming a sort of anterior false apex, which is hidden until the valves are separated. In wossne*«enskli this part is squared off, the girdle is yellowish (when alive), and the valves are much less transverse. It will be surprising if those who have only observed these animals by a few dry specimens in collections are willing to accept the synonymy above given, I confess that not long since I would have been unwilling to believe that the rough, bristly, typical muscosa and the dark, smooth hindsii could be properly com- bined under one name with each other or with the finely reticulated and painted lignosa ; but the study of a large multitude of speci- mens has convinced me no arbitrary line can be drawn anywhere in a fully representative series, beginning with coarsest ciliata [muscosa] and ending with a practically smooth hind*ii. The characters of girdle, sculpture and form are not only variable in themselves, but are found variably combined, except that it is rarer to find coarsest sculpture with a downy than with a bristly girdle. However, even this occurs. On the other hand, out of such a series a dozen forms might be selected which, if only the characters were constant, every one would acknowledge as good species. " Var. HINDSII (Sowb.) Reeve. PI. 62, figs. 99, 100; pi. 63, fig. 57. Shell elongated and much depressed, (the angle of divergence about 140°), the girdle encroaching at the suture*. External color a light or dark shade of olive. Surface smoother than in typical Morxi.i A. the grtfiote-oorrugation b or lenzig-xagorcriit- oi» tin- central arras, «il»li«jm-ly r..migated-grano8e on the lateral aivas. /ntr \rhil>\ "•/'//, «/ 304. The specimens described are from San Francisco Bay. The teg- mentum or outer layer of the valves projects forward somewhat at the sinus, as in typical nmscosa^ but this can be seen only in the detached valves. Var. PORIFERA Pilsbry. PI. 62, figs. 93, 94. Another form of muscosa, which if constant in its peculiar features would make an excellent new species of the section 0«teochiton, is before me from Boliuas Bay. It is perhaps deserving of a varietal name. The shell is rather small, thin and high, but not to as great an extent as M. acuta. It is sculptured as in M. hindsii, but the diagonal and sutural ribs are more prominent, and sculptured with strong, transverse beads exactly as in M. imporcata, the suture being dentated by them. Color of valves olivaceous, clouded obscurely with smoky, and having a black stripe each side of the dorsal lighter stripe. The posterior valve has a depressed mucro near the posterior margin, which is very slightly waved inward. Girdle firm and leathery, minutely and evenly papillose all over, blackish with spots of orange ; having a small pit or pore at each suture, with a series of pores alternating with these a little outside of the middle of the girdle (pi. 62, fig. 93). Sometimes some of the sutural pores bear large hairs, curling outward; and sometimes some or many of the pores are completely absent. Length 23, breadth 13* mill.; divergence 105-115°. The interior is a deep blue-green, or gray-blue \vith a purple-pink blush. Var. ACUTA Carpenter. PL 64, figs. 75-81. Shell rather small, strongly elevated, the dorsal ridge acute : valves thin ; sculpture minute and delicate, varying between a minute granulation and a fine pitting; the sutures delicately dentic- 298 MOPALIA. ulate ; diagonal riblets obsolete or delicately raised. Color oliva- ceous obscurely mottled with dusky, the tail valve having a light ray behind. Interior blue-green. Tail valve slightly waved upward in the middle behind, and having either a simple narrow caudal slit, or a slit with a small tooth set in its apex. Lateral slits of the tail valve generally double on one side. Girdle narrow, sparsely hairy. Length 22*, breadth 12$ mill.; divergence 105° (Carpenter's type). Length 22, breadth 13 mill. ; divergence 105° (San Diego spec.). Length 23, breadth 15 mill.; divergence 98° (Sta. Barbara spec). Santa Barbara (Canfield, Gabb.) ; San Diego (Hemphill). Chiton acutusCpn., P. Z. S. 1855, p. 232.— Mopalia acuta CPR., Brit. Asso. Rep. 1863, p. 648. — Mopalia plumosa and M. (f var.) fissaCpR., MS. (? Not Ch.plumosus Gld). The comparative tenuity of the highly angled valves, their deli- cate sculpturing over the whole surface, the fine denticulation of the sutures and the narrow, often toothed caudal sinus, all give an aspect of individuality to this form, and cause me to rank it with hind*ii and lignosa as a well-differentiated subspecies. Carpenter, working from very few specimens, made three species of the forms of this. The occasional bi-slitting of the tail plate on one side is found also in some specimens of the elevated variety of lignosa from Olympia, Wash. It seems to me to be a very variable and trifling character. The caudal sinus seems to be indifferently narrowly slit or with a little denticle in the apex of the slit, and this little denticle also occurs sometimes in M. lignosa. The posterior valve has a narrow light triangle behind in all the specimens I have seen. I have no hesitation in pronouncing plumosa and fissa absolute synonyms of acuta, but give here Carpenter's descriptions. M. plumosa. Carpenter. (PI. 64, figs. 80, 81.) Shell oval, regu- lar, thin, elevated, the dorsal ridge acute, mucro behind the middle, depressed. Valves subquadrate, slightly beaked behind, hardly so in front. Olivaceous-ashen maculated with darker; central areas (with the scarcely defined jugal tracts) reticulated-porous, being sculptured with interlacing riblets forming quincuncially arranged impressed pits. Lateral areas defined but hardly elevated, sculp- MOPAMA. turnl with plumr-likr radii, granose at the SUtun -, t h.- «ii;iLr"iial ribs and tin- radiating rililrts of the head-valve ; the grains elongated, siihspinose, elegantly strrntimj (fie sutures. Interior pule blue. Tail valve having the p«.~t< Ti-.r linoi hardly indicated externally, xinof/, »/•/'//» .. lignosa Gld., DALL, Proc. U. S. Nat. Mus. 1878, p. 304. Typically the M. lignosa is extremely unlike M. muscosa, but I am compelled to agree with Dall that there exist specimens completely uniting the two. A number of published names are above added to the long list of synonyms given by Dall (1. c.) ; and Ch. californicus (Nutt.) Reeve, which Dall includes, is removed, as it belongs to the genus Nuttallina. The typical lignosa (figs. 58, 59) is exactly equal to merckii, to montereyensi*, and to the unpublished insigni* Newc. (fig. 63). It differs from the following form in the even puncturing of the sur- face (obsolete on lateral areas), the peculiar painting, and white interior. The principal mutations of this type of Mopalia are (1). Toward still smoother forms entirely lacking pitted or reticulated sculpture, having only a few subobsolete longitudinal wrinkles on the ridge, the painting in concentric streaks (following growth marks) on each valve. This is shown in figs. 60, 61, of pi. 63, the specimen illus- trated being from Olympia, Washington. The C. vespertinti* of Gould is closely connected with this form, but is represented as typically much pitted (fig. 62). It is stained with crimson within. (2). Form elevata (pi. 64, figs. 82, 83). More elevated, acutely carinated, more or less pitted superficially, and either painted with the pattern of typical lignox on a white, creamy or green ground, or having concentric zig-zag blackish streaks (fig. 82). Divergence about 90°. The interior is bright green or blue. (3). Forms connecting with M. muscosa var. hi/iK! i ii Sehraick, I'l. ^2, figs. 88,89, 90,91,92. Shell elevated. Coloration: a broad whitish area along the mid- dle, with transverse flainniules and lines «»!' mi-brown "ii tin- rl at th.' lidei concentrically and longitudinally painted \\ith r»-d- brown and whitish. Median valves having the apex indistinct, the lateral JWM- «li- tinet. Kntire surface radially closely pitted, the pits very di.-tim-t over'the whole of the central areas, and in the middle of the lateral areas, but obsolete on the front and back edges of the latter. Anterior valve having 8 radiating riblets. Posterior valve slightly emarginate behind. Interior roseate in the middle ; lateral slits distinct ; sinus shal- low. Anterior valve having 8, central 1, posterior two slits. Girdle of moderate width, brown-red, setose, the setse irregularly and sparsely scattered, whitish, and about 3 mill, in length. Branchiae median, with about 36 branchial lamellae. Length 14 mill. ; divergence about 115°. Bay of Castries in 25 ft. Chiton middendorffii SCHRENCK, Bull, de 1'Acad. des Sci. St. Petersb. iv, p. 408 ; Mel. Biol. iv, p. 89 ; Reisen und Forsch. in Amur-Lande, ii, Zool., p. 278, t. 12, f. 1-8 (1867). A single specimen of this species was dredged by Schrenck, from whose account the above description is compiled. The sculpture strongly reminds one of some forms of Mopalia lignosa Gld., but the coloring differs markedly, and the habitats of the two are widely sundered. M. IMPORCATA Carpenter. PL 62, fig. 98. Shell small, oblong, strongly elevated and acutely carinated, the side-slopes straight. Buff-white, slightly stained ivith rust-brown. The median valves are acute at the umbo, but there is no project- ing beak ; lateral areas bounded by a strongly elevated, narrow, crennltted diagonal rib, and having a wider rib at the sutural mar- gin, also crenulated, thus denticulating the suture ; the space between the two lateral ribs being finely corrugated-granose. Cen- tral areas sculptured with strong, curved longitudinal ribs, which converge forward somewhat, toward the median keel ; the intervals between these ribs being closely and finely latticed across by MOPALIA. threads radiating from the beaks. Anterior valve having 8 strong, nan .1 ribs, with one wider rib at each sutural edge. Posterior valve depressed, the mucro situated at the posterior end. Interior white; sinus very small and shallow. Anterior valve having 8, median 1 slit; teeth but little thickened along the slits. Posterior valve having a rather wide moderately deep rounded tail sinu>. and a single slit on each side. Girdle leathery, dusty, with a hair-pore at each suture, and some scattered or alternating hairs. Length 10, breadth 6 mill. ; divergence 95°. J'lic/et Sound (Kennerley) ; Sta. Barbara (Cooper). imporcata CPR., Proc. Acad. Nat. Sci. Phila., 1865, p. 59. — Placiphorella imporcata CPR., in Dall, Proc. U. S. Nat. Mus. 1878, p. 306.— Osteochiton imporcatus DALL, 1. c. 1886, p. 211. This species closely resembles M. sinuata in size and sculpture. The two species differ in the following details : (a) M. imporcata is unicolored, while the other is elegantly marbled with blue and tawny; (6) imporcata has the sutural ribs more developed and very distinctly serrated, whilst in sinuata the serration is hardly appar- ent ; (c) imporcata has the longitudinal riblets of the central areas larger and the radiating threads which lattice their interstices much smaller and much closer ; and finally, (d) the tail valve in imporcata has an entirely posterior mucro, and a much shallower posterior sinus. The girdles are the same in both species, being leathery, generally " dusty " in appearance in dried specimens, although scales are quite absent. Thi> species might be considered a subspecies of M. muscosa were it not that it is smaller and more highly angled, of a uniform light color, and has the mucro farther to the rear. The girdle-pores at the sutures, and the entire sculpture are exactly like the pore-bear- ing variety of muscosa which I have above described from Bolinas Bay. It is very likely that the intervening links required to com- plete this chain of forms will he found. The description and figures are drawn from Carpenter's type specimen, now in the U. S. National Museum. The length is estimated in this and the following species, as the specimens are somewhat curled. MO r A i.i A. M. BIKUA1 \ Carpenter. IM. i\'2, BgS. 95, '."'•, 97. Shell oblong, elevated Mini -tn.iiLrlv rannat--.!, the .-id,— . Straight. Color whitish, rfnmh-il //•//// fl,-/fc,i(r liliir.-yrr' n iiml , lated ii'ith rich ///»/•//// />/•»•//•//. Median vulvos hardly braked, the lateral areas not raised, but strongly defined by an elevated diagonal rib; sculptured with two oblique series of fine riblets forming a latticed pattern. Central areas having a series of longitudinal curved rihlet.s eonveri:in'_r toward the median keel, crossed by curved radiating threads a little finer and less prominent (fig. 97). Anterior valve having 8 (not counting the posterior sutural borders) strong radiating ril is narrower than the latticed intervals. Posterior valve depressed, the •macro bcintj at the posterior third. Interior bluish-white. Sinus very small and narrow. Anterior valve having 8 slits, median 1 slit ; teeth thickened outside at the edges of the slits. Posterior valve (fig. 96) having a deep rounded infilinn shins behind (which is continued upward in a superficial ition to the mucro), and a single slit on each side. Girdle rather narrow, leathery, " dusty " bearing a few hairs, with a rounded pore at each suture (fig. 95). Length 11*, breadth 7 mill.; divergence 105°. Puget Sound (Keunerley) ; San Francisco Bay (Newcomb). f Mopalia sinuata CPR., Proc. Acad. Nat. Sci. Phila., 1865, p. 59. — Placiphorella sinuata CPR., MS. and in DALL, Proc. U. S. Nat. Mus. 1878, p. 303, 306—Osteochiton sinuatus DALL, I c. 1886, p. 211. This little species has the form and sculpture of the true Mopalias, but it differs from them in the posssesion of a bristle or hair-bearing pore at each of the sutures, the girdle elsewhere bearing sparsely scattered hairs on the leathery, minutely roughened surface. It resembles M. imporcata but is sufficiently different in sculpture. My description and figures are from Carpenter's type specimen, now in the Smithsonian collection. M. CILIATA Sowerby. PI. 64, figs. 64-73. Shell oblong, rather depressed, the dorsal ridge carinated (some- times rounded), side-slopes straight or somewhat convex. Surface lusterless, finely sculptured, variously colored, usually either (1, typical coloring) verdigris green maculated with black or black- brown, the girdle yellow (fig. 65) or (2) maculated with maroon and sometimes touched with rich chestnut on the ridge, or having 304 MOPALIA. some valves or parts of valves vivid scarlet (fig. 64), or scarlet mixed With olive and snow-white, or entirely white; or (3) light olive-buff with brownish girdle (fig. 67). Valves somewhat beaked, the lateral areas bounded by a riblet, rather coarsely granulated, with larger granules along the posterior margin. Central areas sculptured with longitudinal, curving rib- lets somewhat granulated, much closer and finer on the dorsal ridge. Anterior valve having granose narrow radii, the intervals granulated. Posterior valve small, with posterior mucro, broadly emarginate or waved at the hinder margin. Interior bluish-white or light blue-green. Sinus broad and rather rounded, -^pongy or roughened. Sutural plates arcuate. Anterior valve having 8 slits, median valves 1 slit. Posterior valve having a broad deep, rounded caudal sinus, and a single slit on each side. Girdle wide, yellow or brown, generally notched behind, more or less sparsely clothed with curling strap-like brown /m //•>-, which bear near their bases a bunch of minute, ivhite, acute spines (fig. 66; the line below is 1 mill. long). Length 46-50, breadth 25 mill.; divergence 125°. Unalaxhka, Aleutian Is. (small and rare) to Sitka, and tout I I to Monterey, California; low water to 20 fms. on stones and shells. Chiton d/lntus SOWERBY, Ann. and Mag. Nat. Hist. 1840, p. 289; Conch Illustr., f. 79 (1840). Not Chiton ciliatus Reeve, nor Moi»'li'i rilinta Dall. — Chiton wosnestemkii MIDD. Bull Acad. Imp. Sci. St.Pe"tersb. iv, p. 119, 1847.— Chiton (Hamachiton, Platysenuis) wosnessenskii MIDD., Mai. Ross., i, p. 34, 101, t. 11, tl-2.—MopaKa «rleyi CPR., Suppl. Rep. Brit. Asso. Adv. Sci. 1863, p. 648 ; Proc. Acad. Nat. Sci. Phila., 1865, p. 59. — M. (kennerleyi rar.) Swannii CPR., Ann. Mag. N. H. xiv, p. 426, 1864 ; Suppl. Rep. B. A. p. 648. — Mopalia grayi CPR., I.e. p. 603 (name only). — Mop" /in wos8ne8*cn.*kn Midd., BALL, Proc. U. S. Nat. M us. 1878, p. 305 (1879). This species is distinguised from .17. IMUMOM and its immediate allies by its color; by the lack of that narrow anterior projection of the outer layer at the sinus, so conspicuous in the detached valves of the typical mu*cosa; by the encroachment of the wide gir- dle at the sutun-, the deeper caudal wave of the tail valve, and especially by the brom' ' it urn I plates. IM.\< ii-ir<»i:i;i i \. :;or> This last -or ins to be a constant character, and tin; prmliant the tail valve noticed above is also rcliahl.- ; l>nt i arhni.-nt of the girdle at the sutures is seen al-> in .!/. Kindrii : tin- la<-k anterior projection or " false beak "is characteristic of many varie- ties of HI a. .<•!, such as the elevated var. of injiingn found at Olyin- pia, Washington, and the var. acuta Cpr. from southern ( 'ulifornia. The girdle covering presents a peculiarity not hitherto not! near the base of each of the curled brown hairs, there is a bunch of tiny white thorns or spines. These are also numerous at the edge of the girdle, which is seen slightly rolled upward in fig. 66. Dr. Carpenter studied the specimens of" C. c/V////»/x " in ('inning's collection, and found them to be genuine w<< and therefore Ball in his report on the Chitons of Alaska, as well as other Ameri- can writers, accepted the name ciliata in place of muscwft. Unfor- tunately, the Cumingian specimens are not the true ciliatu* of Sowerby, although described and figured as such by Reeve. The original C. ciliatus is identical with the small, green black-mottled form of " wosnessenskii " found at Monterey, etc. An excessively rare monstrosity is shown in fig. 67, representing a seven-valved specimen, in which the reduced number is not due to injury or coalescence of valves, each valve being completely normal both outside and within. This figure, and figs. 64, 65, are drawn from Monterey Bay specimens. The sculpture (fig. 68) is stronger and sharper in typical ciliata than in the VB.T. wosnessenskii (fig. 72). Var. WOSNESSENSKII Midd. PI. 64, figs. 69-73. Shell elongated, the back roundly arched not carinated ; dull colored, varying from light olive or green to drab, generally with blackish patches on each side of the middle, and more or less mot- tled throughout with dusky. Sculpture much fainter than in ti/j)ic'ilin,even a constant specific character. The species are separated by rather slight characters and owing to the rarity of specimens in collections, we are not yet prepared to say to what extent the characters will hold good. P. VI.I.ATA Carpenter, n. sp. PL 66, figs. 6-12. - .ell roundly oval, broad, rather depressed, quite obtusely angled. Surface lusterless. Light colored along the middle, mainly oliva- ceous on the sides, especially the lateral areas; the central areas variou-ly streaked longitudinally with buff, blue, chestnut and pink. Median valves not beaked, marked by growth lines ; the lateral areas somewhat raised, having a rounded wide diagonal rib and another at thesutural margin, the space between them more or less excavated. Central areas having a " false beak " or narrow pro- jection fonvard at the dorsal ridge (only visible when the valve- an* separated.) Anterior valve crescent shaped, sculptured with liirht concentric growth-lines only. Posterior valve small, slightly waved inward behind, the mucr<> >vard, recurred and elevated, the slope in front of it concave in profile, unless the mucro is eroded. PLA< ii'H'.i:i : Interior white, slightly blur tinted. > sented by a very 8/t>il/> fi;i a /t/ittr irliirl, jill.< the .S////M II h- a key-st<>' vii to viii tin- Him- i- derper and more <\\<\ inct I y angular, valve having* slit-, th'1 teeth ohtuse, short, often l.ilohed or COD- spieuously rugose. Central valves having 1 slit, teeth wedge-shaped, thicker at the edges of the slit. Posterior valve having a very heavy callus supporting the short, rugose insert ion-plate, which i- i n ten- n pted posteriorly by a broad, shallow sinus, and ha- 1 -lit on each side (occasionally two on one side). Girdle very hroad in front, reddish, fading to yellow toward the outer edge, irregularly and sparsely beset with scaly hairs (fig. 13), of which one or two are generally to be seen in each suture ; a close fringe of short (broken) hairs adorns the girdle-edge. Length 50, breadth 38 mill. ; divergence 135°. Length 30, breadth 24 mill. ; divergence 130°. Humboldt Bay (Newcomb) and Monterey Bay (Canfield, Hemp- hill, et. al.), California; Todos Santos Bay, Lower California (Hemp- hill). Placiphorella velata CPR., MS.— DALL, Proc. U. S. Nat. MILS. 1878, p. 303, 307 (description of animal) ; p. 298, t. 2, f. 36, a (dentition). This species is distinguished from the the next by its differently formed posterior valve, by the connection of the sutural plates across the sinus, and the anterior projection of the tegmentum at the sinus. The largest specimens I have seen were collected by Hemphill at Todos Santos Bay. Fig. 12 represents the insertion-plates of an intermediate valve seen from their summits, showing the subtriangular form of the posterior insertion-tooth, the non-thickened edges of the slit, etc. P. STIMPSONII Gould. PI. 62, figs. 84, 85, 86, 87. Shell broadly oval, depressed, subangular, with straight side- slopes. Color whitish along the middle, the sides mottled and streaked with greenish-yellow, olive and blue, the colors so blended as to give a general effect of dark olivaceous. Valves not beaked, sculptured with unequal growth-lines. Lateral areas having a moderately prominent diagonal rib, with an inconspicuous wider, lower, sutural rib, the space between excavated. Anterior valve narrowly crescentic, concentrically striated, but 308 PLACIPHORELLA. lacking all radiating sculpture. Posterior valve (figs. 84, 85)- depressed, the mucro near the posterior margin, which is slightly and rather broadly waved inward. Interior delicately blue-green tinted. Sinus a rather shallow rounded wave in the earlier valves, becoming deeper, narrower and angular in the eighth valve. Anterior valve having 8 slits, median valves having 1 slit on each side ; the eaves narrow, tenaciously adhering to the girdle. Posterior valve small, its greatest width, including insertion and sutural-plates, measuring hardly more than one-half the width of the widest median valves ; the short posterior insertion-plate rising from a very heavy callous rim ; having one oblique slit on each side, and an almost imperceptible wave where the posterior sinus should be. Girdle rather narrow, brown, leathery, sparsely beset with spinu- les (the stumps only remaining in the specimen before me), of which there is one at each suture and a marginal fringe. Length 17, breadth 12* mill.; divergence 140°. Hakodadi Bay, Japan (Stimpson), in 25 fms. Chiton (Mopalia) stimpsoni GOULD, Proc. Bost. Soc. N. Hist., vii, p. 165 (1859) ; Otia Conch, p. 118.— Con/. DALL, U. S. Nat. Mus. 1886, p. 210. The above description is from the type in the U. S. National Museum (no. 1646). It will be seen that the species differs from P. borealis in the smooth, not radially sculptured anterior valve, in the strongly calloused interior of the posterior valve, its shallower tail sinus, etc. The P. velata Cpr. of California has the valves very- similar to this species in form ; both differing widely from P. bore- alls in the solid, not spongy, sinus, partly filled by a short lamina connecting the sutural plates ; in the more calloused interior of the posterior valve and its smaller size ; the non-radiated anterior valve, etc. Carpenter has given the following notes in his MS. on a fine specimen from Japan, in the Jeffreys collection. " As curled up and dried it measures, length 23, breadth 21 mill. ; divergence 120°. It is olivaceous and orange-ash variegated. Anterior valve smooth. Posterior valve having the mucro raised, at the posterior third, the sinus continued upward to it outside. Central valves with two obsolete but swollen ribs, one sutural, the other diagonal, with a broad depression between them. The girdle is very much shrivelled PI . \. i ni' i :joi» and the head rxpansion dotihled up, but tin- hair.- :in- very well preserved. Over the whol.- of tin- mar-innl p:t crowded deciduous whitish luiirs. Over the greater portion of the surface are scattered distant lar^e tnlndar, horny hair-, which seem to arise deep in the girdle. Th»>,- hairsan- not scaly an in I'. A///m- I'illti, l)Ut present when perfect the aspect of A«pr.nj HI" in i-'iyim'fcrum in miniature. I eann.it >ay with confidence that all the hairs are so sculptured, for some which look perfect do not show it. " A. sketch made by Dr. Carpenter from a hair of this specimen is •copied on pi. 62, fig. 86. The. hairs on Gould's type are broken to very short stumps, not long enough to show their structure. P. BOREALIS Pilsbry, n. sp. PI. 66, figs. 14, 15, 16, 17. • Shell similar in general characters to P. velata. Brown at the sides, light along the middle. Surface dull, showing growth- lines. Valves not beaked, having a slight forward bend in the middle at the sinus, but not " false beaked " there as P. velata is. Lateral areas more strongly 2 ribbed. Anterior valve sculptured with numer- ous very low, wide radiating riblets. Posterior valve having the mucro near the posterior margin, depressed, the slope in front of it rising, convex rather than concave ; posterior margin waved inward. Interior light blue-green. Sutural plates separated in all the valves by an angular, spongy sinus. Anterior valve having 11 slits, the teeth unequal, lobed or roughened. Median valves having one slit, the teeth being peculiar 1 1/ curbed outward at its edges. Posterior valve much less callous inside than that of P. velata, the insertion- plate uneven, roughened, but having a single well developed slit on each side ; the median tail-notch deep and wide. Eaves very spongy. Girdle unknown to me. Breadth of anterior valve 16, length of front slope, including teeth 4J mill. Breadth of a median valve 22, length from sinus to beak 4* mill. Breadth of posterior valve 15, length direct from sinus to sinus 5 mill. Divergence 135°. Measurements of breadth include the inser- tion-plates. Bering Island, Bering Sea (Grebritzki). Placiphorella stimpsoni DALL, (part), Proc.U.S. Nat.Mus. 1886 310 PLACIPHORELI.A. p. 210. > uld. This t'.»rm iskiiuwn to UK- liy tin1 valves of a single individual, no. uithsoniau register. It differs from P. vel-atn in the greater prominence of the lateral ribs, the curiously excurved teeth of the side insertion-plates (fig. 15), the less calloused interior of the posterior valve, and its very different form. Compare fig. 9 with riir. H>, the former representing the tail valve of P. velata, the latter that of P. borealis. Some other differences are indicated in the descriptions. In this specimen the slit on one side of the pos- terior valve is nearly obsolete. P. BLAINVII.LII Broderip. PL 66, figs. 26-32. Shell ovate, very broad, depressed ; variously clouded, streaked and maculated with rosaceous and olivaceous or red-brown, gener- al Iv tessellated at the sutures. Median valves hardly beaked. Jugal areas sometimes defined by an obsolete v-shaped sulcus. Central areas appearing a trifle and most minutely granulate under a lens, otherwise smooth and shining. Lateral areas slightly swollen, concentrically marked by ribs of growth ; margins of valves rounded, the sutures not very deep except in young specimens. Posterior valve having the mucro pos- terior, almost terminal ; the posterior sinus of the valve wide and shallow. Interior : anterior valve having 8 slits, the teeth rather short and roughened or crenulated outside. Posterior valve having a single slit on each side. Median valves with 1 slit; the sutural-plates rather straight and narrow, sinus a shallow wave. ( .irdle thin, very broadly expanded, in front, narrow and not sinuous behind. Surface having sparse, comparatively short hairs, which in drying become appressed on the girdle, each hair appearing scaly under the microscope, like a snake's skin (fig. 28). The hairs are not especially sutural in position, suture-pores being absent in adult examples ; nor do hairs occur in bunches anywhere. Besides these scaly hairs, there are scattered chaffy hairlets (which in one specimen more contracted than the rest are gathered into little bunches.) Length 50, breadth 36 mill. ; divergence 147°. Inner Lobos Island (Lobos de Tierra'), Peru, on stone in 17 fms. (Cuming.) Chiton blain>;>/;; BltOD., I'. Z. S. \W, p. 27.— SOWERBY, Conch. [PHOBB] i.\ PLAXIPH4 ••! 1 r. S. Ui i \ i . G uah. [oon., t, I, i'. i i/ GRAY, r. /.. U—Jfopafta ! J/\ MII.I in I) M.I,, Proa l'. 8, Nat. MUH. 1878, p. 303.— / hUnmllii DAM,, /. c. 1886, p. 210, 21 1. This lurm' sp.vir- i- nearly allied (.. /'. ,-. fi'ii<>i:<»rMs I'iMu-y, 1 893 (n. s.-g.) Shell short, ol.Mvatr. t lit- valves short and \\ !inns. ( iirdle enormously liroadeiied in front, narrow In-hind. This section is intcn liate between Placiphorella and P/'is!j>hora, •differing from both and from and all Mh < \ ll.aln..-s ', 1883.) Placoph AiiM-r. JotHI :ice xxiv, Nov., iw, p. :;•;.'» (fbotoot theC/oni mt A. -ad. -my O/ Natural >.-i.-n.-, ,. vi. p. 2 f. 1. hi, 1 A. ^ 1884).— Placophnrn Interior light blue ^reen. Sinus small and shallow. Sutural plates low. Anterior valve having 8, central valves 1 slit; the slits short, continued in grooves to the eaves; teeth long, irregularly striated outside, thickest along the slits, sharp edged. Posterior valve having the insertion-plate long and stout at the sides, inter- rupted l>y a rounded sinus in the middle behind; its edge smooth, unslit. Eaves very narrow and very spongy. Girdle rather wide, leathery, having at each suture a small pore bearing several long corneous bristles, and with one or two more or less irregular series of bristle-bearing pores on the surface of the girdle, and a more or less dense clothing of small soft hairs over its outer part. Length 50, breadth 35 mill.; divergence 125-135°. Chiton setiger KING, Zoological Journal v, p. 338 (1831). — Sow- ERBY, Conch. Illustr., f. 17 ; Zool. Beechey's Voy., pi. 40, f. 7 (bad). — REEVE, Conch. Icon. t. ix, f. 48a, t. xiv, f. 48c.— GOULD, U. S. Expl. Exped., Moll., p. 330, f. 425. — Plaxiphora carmichaelis GRAY, P. Z. S. 1847, p. 68, and subsequent writings, probably not Chiton carmichaelis GRAY, Spic. Zool. 1828. — Plaxiphora carmichaelis HADDON, Challenger Report, Polyplac., p. 32. — H. & A. AD., Gen. Rec. Moll, i, p. 481 ; iii, t. 55, f. 3. — Chcetopleura savatieri ROCHE- BRUNE, Bull. Soc. Philomathique de Paris, 1880-1881, p. 119; Miss. Sci. du Cap Horn, Polyplacophores, p. 135, t. 9, f. 3a, 3b. — Chwtopleura frigida ROCHEBR., Miss. Sci. du Cap Horn, p. 137, t. 9, f. 5a, 5b. (young shell.) This is the only well-established species known to inhabit the extremity of South America. It will be readily recognized by the smoothness of the surface, strong diagonal rib, and generally well- defined sutural pores, each bearing several bristles. The variation in color is well-shown on the plate. The C. savatieri (pi. 67, figs. 41, 42), and C. frigida (pi. 67, figs. 39, 40) of Rochebrune are merely, it seems to me, individual mutations of setiger the last being a young shell. It will not escape the observant zoologist that the artist who drew the plate of Chitons illustrating Rochebrune's paper, did not see the lateral slits in the valves. One is likely to infer that the other characters may be equally erroneously represented. Some authors have given Gray's name carmichaelis to this species ; 318 1'i.AxiriroRA. hut this identification rests only upon the synonymy given in Gray's several lists. Waiving lor the moment the question as to the identity of the original mnnicJutelis with setiger, we notice that the rest of Gray's synonymy of this species is in several respects incor- rect. C. biramosut Quoy for instance, is not the same as *etiger ; and his list of Chitons shows a number of other errors of synonymy. It is not safe therefore to trust Gray's dictum in such matters ; and it may fairly he doubted whether the original cannirhaelis, which is described as being " scarcely keeled," one-half an inch long, etc., etc., is the same as the large, strongly carinated Ch. setiger. In any case, Gray's name should be ruled out on the score of faulty definition. The name setiger was acceptably defined ; the species correctly located by King; and it was sheer piracy on Gray's part to shift his name from some poor little half-inch Cape of Good Hope specimen to this fine large form from Cape Horn. The original description of carmichaelis is as follows: Chiton carmichaelis Gray. Shell oblong, convex, scarcely keeled, smooth, bluish-brown streaked and lined with white ; front valves with distant rather broad radiating nodulose ribs; front and back margins of the lateral areze of the middle valves with a single similar rib ; hinder valve smooth. Margin scabrous, brown. Length £ an inch, breadth |. Icon. Wood, Cat. Suppl., 1. 1, f. 10. Inhab. Cape of Good Hope. Capt. Carmichael, Brit. Mus. Chiton carmichaelis GRAY, Spicil. Zool. pt. 1, p. 6 (July 1, 1828). Not ritu-ijthnra carmichaelis GRAY, P. Z. S. 1847, pp. 68, 169.— P. carmichaelis GRAY, Guide Syst. Dist. Moll. B. M., p. 186. Var. FRKMKI.YI Broderip. PI. 67, figs. 37, 38. Shell oblong, flattened, olivaceous-brown, varied with whitish- green lines ; anterior valve with elevated subgranose rays ; inter- mediate valves angular at the sides, the lateral areas biradiate, rays subgranose, intervals longitudinally subsulcate. Girdle set with numerous short bristles. Length If, breadth 1 inch. (Brod.} Bay of Valparaiso (Cuming). Chiton frembleii BROD., P. Z. S. 1832, p. 28.— C. setiger var. fremblii SOWB., Conch. Illustr., p. 7, f. 4. — Chcetopleura huhni ROCHEBRUNE, Miss. Cap Horn, Polyplac., p. 136, t. 9, f. 4 (1889.) This differs from P. set'ibtusely carinated, violaceous-bluish, with spots and lines of brown irregularly distributed. Anterior valve rounded, with 10 radiating ribs. Posterior valve very small, elliptical, feebly beaked. Lateral areas of the median valves narrow, bounded by a beaded rib; central areas covered with deep concentric stria', and very minutely striated transversely. Girdle wide, brown, covered with tawny hairs. Length 48, breadth 35 mill. (Rochebrune.} P. BIRAMOSA Quoy & Gaimard. PL 68, figs. 51-54. Animal ovoid, elongated, flattened, valves very transverse, little elevated, forming a low arch, not carinated ; striated transversely in front. White or green with a circle of red-brown on each valve. The anterior valve has 9 teeth on its edge, the posterior valve none. The sutural laminre are not wide, and are separated only by a very obtuse sinus. The insertion plates are slit at the sides at usual. Inte- rior dull white. Girdle nude, vivid red-brown, having two spaced series of rough, sparse and bifurcating hairs, the inner series contiguous to the valves, the other near the periphery of the girdle, which is also hairy. (§.<£(?.) Length 45, breadth 31 mill. Chiton birnmosus Q. & G., Voy. de FAstrol. Zool. iii, p. 378, t. 74, f. 12-16. — Plaxiphora biramosa Q. & G., HUTTON, Man. N. Z. Moll. 1880, p. 116 (translation of Quoy's diagnosis). — Acanthochcetes lii-iimosus HUTTON, Trans. N. Z. List, iv, p. 181 (incorrect descrip- tion, from Deshayes). — Pladphora superba CPR. MS. The external form is noticeably different behind in the two individuals which we possess ; but the red color of this species and its two series of bifurcating spines will readily distinguish it. ( Q. & £.) I believe the form which Carpenter described in MS. as P. is the same as Quoy and Gaimard's C. biramosus. Carpenter's description is as follows : P. superba (pi. 68, figs. 55-61). Shell large, oval, elevated, the dorsal ridge acute ; mucro subposterior, little elevated. Reddish- olive, maculated with darker and paler. Valves nearly rectangular, 320 I'LAXIPIIORA. but well indented at the sutures, having a " false apex " in front. Lateral areas having indistinct, subobsolete radiating riblets. Ante- rior valve subangled by 8 radii, which slightly undulate the peripheral margin; otherwise nearly smooth except for growth- lines. Interior : posterior valve having the insertion-plate elevated, rounded, interrupted in the middle behind by a very narrow, deep sinus. Anterior valve having 8, central valves 1 slit; teeth long,. slightly striated and slightly thickened at the edges of the slits out- side. Sinus narrow, short. Sutural laminae continuous over the ante- rior false apex. Girdle (fig. 61) tough ; black, leathery, hardly sinuated behind, smooth, with a few bristles at the sutures and around the margin. Length 60, breadth 40 mill. ; divergence 110°. New Zealand (Mus. Cum., no. 2.) This very fine but unsculptured species was marked as new in Dr. Gould's collection, but not described by him. It is abnormal in the nearly smooth aspect of the tough girdle, in which however the binary pores (of which five surround the head valve) are distinctly marked. The shape of the valves is nearly as in Mopalia wosness- rnsk'd. (Cjpr.) Professor Hutton has considered his Tonicia corticata a synonym of biramosa, in his Manual of New Zealand Mollusca, 1880 ; but the description (copied below) would hardly lead me to the same conclusion, although Hutton's species is undoubtedly a Plaxiphora* In sculpture it must resemble P. terminalis. Tonicia corticata. Oval ; margin naked ; valves much depressed ; posterior margins slightly concave ; lateral areas bounded on each side by a flatly nodulose ridge, the space between being obliquely striated, the striae running outward and backward ; median areas rugose, without either distinct lines or granules. Length 1*25, breadth 1'13 inch. Color: margin black when dry; valves grey; inside white, covered over with white, coralline growth and small marine algse. Founded on a specimen in the Colonial Museum, locality not stated. (Hutton, in Trans. N. Z. Inst. iv, p. 180, May, 1872.) P. SIMPLEX Carpenter. PI. 67, figs. 43, 44, 45, 46. Shell similar to P. modesta, but more elevated, longer ; valves rude, maculated with brown-purple; dorsal ridge rounded; mucro posterior, flattened ; lateral areas scarcely defined ; valves rounded, i-i \\M-HMI; L with larjr -iitures. Entire .-m th, L'«'n- spoiiL,ry. Interior; j.n>t. rior valve with a Hindu ah-iy ••!<• insertion-plate, moderately Miniated behind. Anterior valv v.itli *, median valves 1 slit; teeth acute, scarcely thicken, d at the .-d^es of the slits. Kave> short, sj gy. Sinus very narrow, -niooth, straii'lit. Girdle spongy, having very close, small hairlrts, and loiiLr<'i hairs scattered and at the sutures. (Q?r.) Length 1-35, l>readth '7 inch, divergence 120°. Var. : length 1*1, breadth •<;."> inch, divergence 100°. Tristan Inland, Tristan da Cunha, on the shore, and off Nighten- gale Island, Tristan da, Cunha, 100-150 fms. ('Challenger.') Euplaciphora simplex CPU., J/N. — P/axiphora simplex CPR., in Haddon's Report on the Polyplacophora of the Challenger Expedi- tion, p. 33. Also described by HADDON, I.e., p. 34, t. 3, f. I-'!, 13a-c. This species I have not seen. The P. modesta alluded to by Car- penter is a form of P. petholata. Haddon describes P. simplex as follows : Shell smooth, simply marked with line of growth, flat sides meet- ing at a variable angle. Anterior valve small, surface smooth. Under surface with eight slits, teeth fairly long, smooth and sharp ; eaves short. Intermediate valve : Central area ; smooth, flat. Lateral areas inconspicuous, with two or three very faint radiating ridges. Under surface with a median horizontal rib-like swelling ; sutural laminae broad, but not deep ; jugal sinus wide and shallow ; one lateral slit ; eaves short. Posterior valve very small and flat, greatly corroded; umbo apparently flat and terminal; posterior border thickened. Under surface : sutural laminae as in intermediate valves, but the jugal sinus is comparatively narrow and deep ; slits and teeth absent ; posterior border much swollen. Girdle very thick and fleshy, upper surface having a spongy appearance, owing to being beset with very short horny spines, which are scarcely raised above the surface; there are tufts of longer spines, three to nine in each tuft, opposite the sutures of the valves; these have no definite position round the anterior valve. Situated outside these are numerous scattered similar tufts, usually somewhat smaller in size, which pass into an imperfect peripheral fringe of spines, (pi. 67, figs. 44, 46). Color: all the valves of a uniform dark brown, with a pale (lilac) narrow triangular band along the 21 322 PLAXIPHORA. juiriim of the intermediate valves (and anterior area of the posterior valve). Under surface of all the valves of a bluish-green color ; lamina? of insertion paler. Girdle, upper surface dark brown ; under surface dusky orange. Length 40, breadth 25, height 10 mill. ; angle of divergence 125° to 135° (two specimens from 100 to 150 fathoms.) Length 25 to 35, breadth 14 to 17, height 8 to 9 mill. ; angle 90° to 110° (two shore specimens.) Group of P. wahlbergi. No sculpture except some concentric lines; sinus deep, dentic- ulate ; girdle without sutural tufts. P. WAHLBERGI Krauss. PI. 55, figs. 17, 18. Shell ovate-oblong, slightly convex ; brown with a chestnut-brown median band and two yellowish longitudinal bands. Concentrically sulcate. Interior white, brownish-violet in the middle. Anterior valve semilunar ; posterior valve subtriangular, depressed ; inter- mediate valves subreniform, having distant concentric grooves on the front part of the central areas, and on the lateral areas. Girdle brown, leathery, velvety. Length 15, breadth 9 lines. This species has rather thick, little convex valves, rounded on their outer ends, and having the older or posterior half of each eroded, and deprived of color and sculpture. Lateral areas not differentiated. The forward part and the sides of each valve have 6 or 7 separated, sometimes finely granulated furrows, parallel with the margins. The posterior margin is eroded, probably beaked in the middle. The insertion-plates are narrow, roughened outside. Anterior valve excavated behind, having 8 slits. Posterior valve lacking teeth. The valves have in the middle a chestnut-brown shining band, 2 mill, wide, on each side of which a yellow streak of greater or lesser width generally lies ; but usually they are eroded and gray. (Krauss.) Table Bay, Cape of Good Hope. Chiton wahlbergi KRAUSS, Die Sudafrik. Moll., p. 36, t. 3, f. 1 (1848). — Eupladphora wahlbergi CPR., MS. May be known by the separated concentric grooves of lateral and central areas, parallel with the valve-margins, and also by the sinus, which is deep, narrow and denticulate, the last being an unusual character in this genus. The girdle has irregular setae. I'l. AMPHORA. Shell somewhat sculptured. (iinlh- covered with rri-p hair-, not forming bunches at tin- .-mures, nor having pores there. P. PETHOLATA Bowerby, 1M. 68, figs. l, th>- corrugation becoming fun. r toward the middle, and giving place to a microscopic pattern resembling a dense punctula- tion united with a minute zigzag or vermiculate wrinkling. Anterior valve having about 9 narrow radiating riblets, the intervals densely and finely zigzag-punctate. Posterior valve depressed, wide and short, the mucro at the posterior edge, slightly acute and a little elevated ; posterior area of the valve very narrow, ill-defined. Interior dark blue-green. Sinus deep, uide, angular, its edge light brown and very spongy. Anterior valve having 8 slits, correspond- ing to external riblets, central valves 1 slit ; the teeth acute, some- what thickened at the edges of the slits. Posterior valve having a rather blunt, smooth insertion plate, interrupted by a shallow sinus in the middle behind. Eaves very narrow, spongy. Girdle rather wide, black-brown and brown alternately, rather densely clothed with corneous or dark brown bristles, large and small, not in the least arranged in series or issuing from sutural pores. Length 40, breadth 27 mill.; divergence 125°. Length 32, breadth 18 mill. ; divergence 130°. Length 45, breadth 25 mill. Australia (Sowb.) ; Tasmania (Cuming.) Chiton petholatiis SOWB., Mag. of Nat. Hist. New Series, iv, p. 289 (May, 1840) ; Conchol. Illustr., f. b'4, 65, and var. porphi/ri,'*, f. 59. — REEVE, Conch. Icon., f. 74. — fctijilm'ijJtnra petholata CPR., MS. Not Plaxiphora petholata ANGAS, P. Z. S. 1865, p. 187 and 324 r i. AMPHORA. 1867, p. 224.— Eitptadpl'ora modesta CPR., MS. The sinus is squared, and the internal layer is bevelled off expos- ing the. very porous outer layer as in Nuttallina. Back of this porous area, the width of which varies, the surface shows transverse cuts or puncture-slits. The hairs of the girdle show no trace what- ever of arrangement in tufts or pores. The exterior is finely sculpt- ured with zigzag wrinkles, and the diagonal riblets on each valve, as well as the radii on the head valve, may be either nearly smooth or closely granose. The pattern of coloring is characteristic- but still quite variable. Var. CONSPERSA Adams & Angas. Shell oval, little elevated, with obtuse dorsal ridge. Ashy, with a few scattered clouds of dark and olivaceous. Valves squared, thin ; apices not conspicuous, jugal areas marked off by slight indentations which are slightly divergent; but other- wise finely sculptured like the rest of the middle part of the central areas ; pleura having about 20 irregularly roughened line on each side, the line mainly forming right angles with the diagonal rib, but branching and minutely undulating ; becoming very fine toward and upon the jugum ; interstices very small. Lateral areas with the diagonal rib much elevated, rendered nodulous by the wrinkles pass- ing over it ; the same sculpture extending across the lateral areas and becoming more nodulous at the suture. Anterior valve having 8 ribs, besides those at the sutures. Posterior valve having the mucro at the posterior fourth, and with two diagonal ribs. Interior : anterior valve having 8 slits, median valves 1 slit, corre- sponding to the external ribs ; the teeth slightly thickened at the edges of the slits. The posterior valve has well developed, sharp insertion-plates on each side. Girdle pale brown, maculated with black-brown ; bearing fine, sparsely scattered soft corneous hairs. Length 21-22, breadth 12-14 mill., divergence 117°. Port Lincoln, South Australia, under rocks (Angas.) Chcetopleura conspersa AD. & ANO., P. Z. S. 1864, p. 193. — ANGAS, P. Z. S. 1865, p. ISl.—l'laciphora conspersa CPR., J/\ I have seen no specimens of this form, which Carpenter believed to be a variety of P. petholata. The above description is from Car- penter's MS., and was drawn from Angas' type. i-i AXii-noi: v. P. CAI:I-I MI to lla.l.lon. I'l. o7, Bgl 8 Shell smooth, the lidef meeting al an angli . Ant- valve with riirht radiating ridges, not counting the swollen po-t Itonlrrs. Numerous n.n.vnt ri<- miii..r ridges cause these ridges to be rugose. Under iUrfftOQ \\ith nine slits, two 1 »• -ing very close toget eaves sliort. Intermediate valves: central area smooth, with tin.- linos of growth ; no distinct keel. Lateral areas prominent, concentrically rugose, with a beaded ridire aloiiLr tlic anterior border, and, to a less extent, along the posterior border. Under surface with a median hori- zontal rib-like swelling; sutural lamina broad, but not deep ; ju.iral sinus shallow ; one lateral slit ; eaves short. Posterior : valve anterior area so large as to reduce the posterior area to a minimum ; smooth ; umbo minute, nearly terminal. Posterior area merely forms a con- centrically grooved thickening of the posterior border of the valve- Under surface : sutural lamina? as before, but the jugal sinus is com- paratively narrow and deep ; slits and teeth absent ; the posterior border is greatly swollen. Girdle closely beset with very minute horny spines. The specimen had been dried when I received it, and none of the longer spines, characteristic of other species, are observable ; but I think I can discern traces of small sutural tufts. Color : anterior valve with a median triangular area, with the apex at the umbo, is of a kind of chocolate color, which is variegated with minute zigzag grey lines ; the lateral spaces are of a dark slate color. Intermediate valves: central area: jugum pink; greenish toward the umbo when worn down. Pleura dark greenish-brown, with irregular longitudinal green bands. Lateral areas madder brown, blotched with brown. Posterior valve : anterior area resem- bling the central areas ; posterior border pinkish. Under surface of all the valves pale bluish green ; lamina? of insertion white. Girdle reddish-brown. Length 14, breadth 9 mill. ; height 4 mill. (Haddon.) Tristan da Cuntm. Plaxiphora carpenteri HADDON, Challenger Rep. Polyplac., p. 34, t. l,f. 8; t. 3, f. 8«-hor« fernt in'. in M IH. ( 'inning. — f'liifnn ( Ttaxi- l»horn') trrminn/i* K. A. SMITH, \'.,y. Kn-biis and Terror, Moll., p. 4, t. 1, f. 13 (1874).— riajcljJiom t'TminnIi* Smith, HUTK-.V, Man. N. /. Moll. 1880, p. 116 (reprinted from Smith.) Smith lias described this species in detail, as follows: "Shell elongately »>\ate, rather elevated, roundly angled along the top of the valves, black or bluish-black, with a white wedge-shaped stripe with a black one within it down the centre of the valves, forming a continuous white stripe divided by the black one along the center of the shell, in some specimens with a few short white dashes diverg- ing from the radiating ridges. The intermediate valves mucronated, bisected on each side by one raised radiating rib, the posterior mar- gins sinuated and thickened by coarse concentric lamellae ; the entire surface is covered with minute striate-wrinkiing, those near the ridge being coarser than the rest and radiating from it like the webs from the shaft of a feather. The posterior terminal valve has the mucro quite terminal. The anterior valve radiately eight-ribbed (at times one or two additional minor ones are present) with diverging oblique striations on each side of them. Interior of valves greenish- blue ; valve lobes whitish, the sinus between them deep ; the hairs or bristles on the mantle-margin are short, few and horny, those arising from the nine pores being thicker than the rest. " Largest specimen (in a contracted state) 42 mill, long ; width of valves, 20 mill. ; an average specimen, length 25 mill.; width 11 mill. New Zealand (Col. Bolton and Capt. Stokes.) " Terminalis " appears to be but a manscript name attached to some specimens in the Cumingian collection. As I understand that Dr. P. P. Carpenter is engaged on a work on Chitonidcel retain the characteristic name he imposes. The central white stripe with the black one within it appears to be very constant." Carpenter gave the varietal name zigzag, (in MS.) to specimens in the Cuming collection (no. 31) having stronger sculpture, one more anterior riblet, etc. It seems to be, merely an individual variation. P. EXCURVATA Carpenter, n. sp. Shell elongated, elevated, the dorsal ridge rounded, valves angled at the sides, obtusely beaked, the sutures indented. Irregularly maculated with coppery green and black. Lateral areas defined by an obtuse curved rib ; toward the rib on 328 PLAXIPHORA. each side closely concentrically sulculate. Anterior valve having about 7 or 8 ribs, sometimes with some intercalated subobsolete riblets. Posterior valve small, the mucro subposterior, swollen. Interior blue. Anterior valve having 7-8, median valves 1 slit; teeth long, acute, scarcely thickened at edges of the slits. Posterior valve having an obtuse insertion plate, a little sinuated in the middle behind. Sinus broad, straight, spongy. Girdle wide, thin, hardly sinuated behind, tessellated with brown and ashy, beset all over with sparse, delicate, short setae, longer at Ihe sutures. Length 70, breadth 39 mill.; divergence about 110°. Australia? (Haines Coll., and Coll. McGill University, Mon- treal.) . Euplaciphora excurvata CPR., MS. This shell has a general external resemblance in size and shape to P. cuprea, from which it is known at once by the color and sculpture outside, by having no posterior slit in the girdle, and inside by the smoothness and sharpness of the insertion-plates. It also resembles P. superba, but is entirely destitute of sutural pores. P. CJKLATA Reeve. PI. 58, figs. 21, 22. Shell oblong-ovate, somewhat attenuated anteriorly, terminal valves (the posterior of which is small and slanting) and lateral areas of the rest broad-ribbed and neatly carved with close-set waved lamina? ; central areas very minutely reticulated. Beautifully orna- mented with green and pink. Ligament horny, here and there bristly. (Reeve.) New Zealand (Earl, Cuming.) Chiton ccelatu* Rv., Conch. Icon., t. 17, f. 101 (1847).— Strepto- chiton cupreiis CPR., MS., olim. — ? Tonicia zigzag HUTTON, Trans. N. Z. Inst. iv, p. 181 (1872.) The verdigris green and peculiar pink color-pattern is character- istic and singularly beautiful. Von Martens has stated that Tonicia zigzag Hutton is a synonym of " Acanthopleura " ccelata Rv. (Crit. Cat., p. 49) ; a conclusion accepted by Hutton (Man. N. Z. Moll., p. 115, 1880). As in other cases of alleged identity, the original type of zigzag should be re-examined. Button's description is as follows : Tonicia zigzag Hutton. Oblong; mantle slightly tomentose; valves slightly flattened on each side, but not keeled; posterior ri. \\irn margins >lopin«r harkwanU into a point, rrennlated on !. anterior valve with !' radiatim: rid -.:»•- >iie concc-i. zig-zag stria*; lateral areas with two, on <-:i< I ulges crossed by line zig-zag stria- ; pOtterioi and median ar«-;is with fine oblique stria- divrr-m'j- t'n.ni the dorsal line out ward ami tor Md by others divrririni: outward and buekward forniing an en-ine turned pattern. Length 88 inch. ; breadth .'51 inch. Color, mantle white; vakvs .irivyisli-blark with a white -tripe on each side of the dorsal line ; interior Lrreenish-Une. A single specimen is in the ( 'olonial Museum, locality Dot st:r (Button.) The following species probably belongs here, but I have seen no specimen, and it has not been figured. CHITON (CH.ETOPLEURA) PLUMOSUS Gould. Shell brown-ashy, valves concave scarcely beaked ; anterior valve ornamented with plumose radiating line; posterior valve small, the apex marginal and having a submarginal rib on each side. Central area large, ornamented with divaricating stria?, and lateral plumosely co-united striae. Lateral areas small, bounded by asutural rib, striae denticulated, interspaces clathrate. Girdle broad, leathery, furnished with (bristly?) tubules. Length I'D, breadth '75 inch. (Old.) Habit'tt tnil-n Allied to C. ccelatu* Kv., which is said to be highly ornamented with green and pink. (7. collei and C. mmcosus G. belong to the same group. (Old., in Proc. Bost. Soc. Nat. Hist, vii, p. 165.) Section Guildingia Cpr., 1893, n. sect. . Guildwyia CPR., MS., and in Dall, Proc. U. S. Nat. Mus. 1881, pp. 284, 288 (type G. obtecta Cpr. MS.) Shell and girdle like Plaxiphora, except that the valves are partly immersed by the encroachment of the girdle. This section, like Fannettia in the genus Toniria, rests upon a character of very little taxonomic value ; but as it is useful in break- ing up a large genus for convenience in identifying, it has been retained. 330 PLAXIPHORA. P. OBTECTA Carpenter, n. sp. Shell large, broad, partly covered. Valves smooth, most minutely punctulate angulate in front ; sutural sinus large, produced forward over the jugum ; lateral areas scarcely defined except by an angle at the forward outer margin of the valves ; dorsal ridge rounded. Intense olivaceous, paler on the dorsal ridge. Mucro of posterior valve terminal hardly produced. Interior : posterior valve with flattened insertion-plates. Anterior valve with 8, central valves 1 slit ; teeth very acute, long, smooth, a little thickened at the slit-edges ; eaves narrow, spongy. Sinus deep, very obtusely angular, with a spongy area. Sutural laminae long, separated. Girdle very broad, sinuated behind, with bundles of about three large, horn-like hairs at the sutures, and having smaller ones sparsely scattered all over more or less closely. ( Opr.} Length 50, breadth 32 mill.; divergence 120.° New Zealand (Mus. Cum., no. 45.) This very interesting shell differs from the typical Plaxiphorw as Fanneltia does from Tonicia. It is, however, simply an exaggera- tion of P. terminalis. Section Fremblya H. Adams, 1866. Frembleya H. AD., P. Z. S. 1866, p. 445. Type F. egregia H. AD.— Fremblya CPU., MS. and in Proc. U. S. Nat. Mus. 1881, p. 284. — Streptochiton CPR., MS. olim. Shell and girdle like Plaxiphora except that the former is short and broad, the tail valve very much reduced in size, strongly arched upward in the middle behind. Slits in intermediate valves poste- riorly situated. Girdle having more or less obvious sutural pores. The sculpture of these forms is like that of the more elaborately carved Plaxiphoras of the same regions; but the considerable modification in the general form of the tail valve may be held to be sufficient ground for the retention of Adams' generic name in a sec- tional sense. The organization throughout is otherwise very similar to that of Plaxiphora. Two species only are known : P. egrcgia, in which the shell is of a peculiar cg.ir shape, wider behind the middle, and the insertion plates are much thickened outside at the edges of the slits, and P. ovata, in which the shell is widest at the fourth valve, rapidly narrowing toward both ends. The following description of his new genus is given by H. Adams : i. \ \ i / • , jni. nov. Testa ovali-, convexa. Valv:i- tran.-\- cariiiata1; apex p..Mrrioris valva- terminal!-, produeta, : Limlms anirii>tiis, posticr H-sii-. srti- conn-is den-e ol».-itu-. The covering of the mantle, the form of the visible portions of the valves, and the peculiarity ot'tlie terminal valve, render thi- ftpecfol distinct from any form of Chitonidrc yet descril.ed. It lias the appearance ofa7,"nm with the mantle covered with long bristles instead of imbricate scales." There seems to be no reasonable objection to the correction of the etymology of Frembly's name, which in H. Adams' article was incorrectly spelled through inadvertence or typographical error. P. EGREGIA H. Adams. PI. 65, figs. 80, 81, 82. Shell ovate, a little narrower in front, green-brown, paler at the sides. Anterior valve radially ribbed, the ribs pustulose, interstices obliquely lirate ; posterior valve and median valves subcarinate, the dorsal areas densely longitudinally lirate; lateral areas radially rib- bed, the ribs pustulose. Girdle moderate, furnished with short, corneous spicules. (H. Ad.) Length 15, breadth 9 mill. "Habitat unknown" (Ad.); Newcastle, Australia (Dieffenbach, teste Cpr.) Frembleya egregia H. AD., P. Z. S. 1866, p. 445, t. 38, f. 9.— Streptochiton tortuosus CPR., MS., olim. Of this species I have seen a single mutilated specimen, no. 36,638 of the Smithsonian Institution register. It is yellowish along the middle and at the side margins of the valves, pale green on the side- slopes. The species differs from P. ovata in being widest behind the middle. Carpenter describes the type as follows : Shell olivaceous, maculated with more or less intense ; ovate, broad, elevated ; dorsal ridge rather acute, much elevated, the side-slopes straight. Valves strongly beaked, each one eroded in front from the attrition of the next valve forward. The central areas have about 16 line on each side, about equalling the interspaces in width. Lateral areas elevated, bicostate, the ribs strongly granose, granules larger at the sutures, intermediate space obliquely costate or v-costate. Anterior valve having 10 radiating ribs, the interstices sculptured with v-shaped sulci, the v'-s meeting over the ribs and rendering them somewhat nodulous. Posterior valve with posterior elevated mucro and a single posterior rib on each side ; posterior area very narrow 332 PLAXIPHORA. and smooth. The girdle has soft hairs, and a few larger, and there is some trace of pores. The posterior slit in the girdle mentioned by Adams seems to be an accidental tear ; H. Adams believes the same. Length 15, breadth 10 mill.; divergence 133°. P. OVATA Hutton. PI. 54, figs. 34-40. Shell short-oval, very wide in the middle, rapidly narrowing toward the ends ; moderately elevated, the dorsal ridge carinated, side slopes slightly convex. Surface lusterless, sculptured in "herring-bone1" pattern. Color buff along the ridge, pale olive-green on the side- slopes, with a small curved dark spot or two on each valve. Median valves broadly v-shaped, the apices of the valves elevated and acute. Lateral areas narrow, a little raised, the diagonal rib sculptured with a series of closely super-imposed v's, their apices directed toward the beak of the valve, one limb of each v direc- ted outward, curving, and forming the sculpture of the pleura, the other limb forming an oblique corrugation of the lateral area (fig. 40). Sutural margin of each lateral area obliquely, coarsely granose. Central areas having a nearly smooth band along the dorsal ridge, and numerous slightly curving and diverging riblets on each side. Anterior valve small, its width about that of one side- slope of the fourth valve, its apex elevated and slightly recurved ; surface having 8 strong ribs, besides those at the sutural margins, the anterior ribs strongest and wider apart; ribs nodose, intervals obliquely corrugated. Posterior valve (figs. 36-39) small, forming an extremely narrow crescent, strongly curved upward at the acute pos- terior mucro, the front (" central ") area narrow, concave ; viewed from behind (fig. 37) it presents the appearance of a wide inverted v. Interior bluish-white. Sinus exceedingly broad, rounded, the sutural-plates widely separated. Insertion plates long, having the slit near the posterior edge of the plate. Anterior valve having 8, median valves 1 slit. Posterior valve (fig. 39) having a keel-like insertion-plate without slits on each side, and a broad sinus in the middle behind. Girdle rather narrow, yellowish, bearing a pore-tuft of hyaline white bristles at each suture and a fringe of bristles at the edge. Length 15, breadth 13 mill.; divergence 112°. Cook Strait; Duwdhi, Xcw Zealand ; on seaweed. Acanthochcetes ovatus HUTTON, Trans. N. /. lust, iv, p. 182 (1872). ri. \\irii< ovotui Hi PTCW, Man. N. X. M"1I., p. 177 -1880.) This species differs from / a in contour Bivalve the widest, tin- .-ixth mueh n:irrnw.-r. whilst in t species the fifth and sixth valves are as wide as tin- fourth : i <»\-er the side teeth of ovafa do IK.I ieen to l)c thickened at the edges of the slits as they an- in f///vv//'./. The specimen described and figured was sent by Professor Iluttoii. ERRATA. Page 75, dele the word ISCHNOCHITON, in 8th line. Page 97, 1. CURTISIANUS is not an Ischnochiton but a Liolophura, see p. 242. Page 110, For "7. regulatw" read " J. rugulatiu." Page 133, " I. PUSIO" is probably not an Ischnochiton, but a true Chiton, and it is likely to prove identical with Chiton murrayi Haddon, described on p. 161. Page 151, line 11, for " indentification" read "identification." Page 182, last line, remove " C. scytoderma " from the synonymy of C. rubicundus. Page 191. The authority for C. SULCATUS should be " Wood," not " Sowerby." Page 204, line 14, for "indentification" read "identification." Page 206, fifth line from bottom ; the reference to Savijrny should read " t. 3, f. 6, 1-2," instead of" f. 4." Page 329. " Chiton (Acanthopleura') piceolus" Shuttlew., included under Acanthopleura granulata as a doubtful synonym, is probably referable to the genus NUTTALLINA, s. g. Middendorffia, and it should be compared with JV. rlnerea Poli, p. 283. NOTE. The Index to Chitons will accompany the conclusion of the mono- graph, to be contained in the next part of the MANUAL. EXPLANATION OF PLATES. NOTE. — The drawings credited to Foord, Smith and Emerton were prepared under the supervision of Dr. Carpenter, and were loaned by the Smithsonian Institution, for reproduction in the MANUAL. PLATE 1. FIGURE. PAGE. 1-13. Lepidopleurus benthus Haddon. Challenger, . . 9 14-22. Lepidopleurus belknapi Dall. Challenger, . . 7 PLATE 2. 23-31. Lepidopleurus alveolus Sars. Moll. Arct. Norv., 6 39, 40. Lepidopleurus pagenstecheri Pffr. Moll. S. Georg., 12 41, 43-46. Lepidopleurus cajetanus Poli. Ross del., . 15 42. Lepidopleurus cajetanus Poli. Conch. Icon., . . 15 47-50. Lepidopleurus grauoliratus Cpr. Pilsbry del., . 14 51-53. Lepidopleurus granoliratus Cpr. Foord del, . 14 PLATE 3. 54-57. Lepidopleurus cancellatus Sowb. Moll. Reg. Arct., . 3 58. Lepidopleurus cancellatus Sowb. Ross del., ... 3 59-63. Lepidopleurus arcticus Sars. Moll. Reg. Arct., . 5 64-66. Lepidopleurus asellus Speng. Ross del., . .13 67-70. Lepidopleurus rugatus Cpr. Pilsbry del., . . .11 71-79. Hanleya hanleyi Bean. Moll. Reg. Arct., . . 17 PLATE 4. 74-77. Hanleya hanleyi var. abyssorum Sars. Moll. Reg. Arct 18 |78-81. Lepidopleurus curvatus Cpr. Emerton del., . .16 82-84, 85. Hanleya mendicaria M. & A. Emerton del., . 18 83. Hanleya mendicaria M. & A. Inv. Mass., . . .18 86. Lepidopleurus rarinotus Jeffr. P. Z. S., . See Appendix. 87. Lepidopleurus catillus Rv. Conch. Icon., . . .10 88. Lepidopleurus fuliginatus Ad. & Rv. Conch. Icon., . 10 PLATE 5. 89-100. Hemiarthrum setulosum Cpr. Challenger Rep., . 20 (334) i \i-i \- - 335 1 :;. iromiarthnini srtulosuni Cpr. Moll. > ' . . 20 4-8. Qemiarthrom wtolotum Q>r, Kmrrton id, . 35 59. Chsetopleura janeirensis Gray. Conch. 111., . . .37 60. Chsetopleura janeirensia Gray. Pilsbry del., . . .37 61,62. Chiton segmentatus Rv. Conch. Icon.(=Chsetopleura janeirensis), ... .... 37 63, 64. Chsetopleura spinulosa Gray. Conch. Icon., . . 38 65, 66. Chsetopleura dieffenbachi Rve. Conch. Icon., 67, 68. Chsetopleura sowerbyana Rve. Conch. Icon, . . 39 69, 70. Chsetopleura gemmea Cpr. Emerton del., . . 31 71-74. Chsetopleura gemmea Cpr. Ross del., . . .31 i \ri.\\ \ i [OX Of i'i \ PLATE i i. 80. Chaetopleura Dobilis Rve. ( ouch. Icon., 81. Cyanoplax hart uviri < '|>r. Original, . . . .45 82,83. Cyanoplax hart wriri < '|>r. Kiin-rton del., . . . 1-0 84,85. Cyanoplax bartwegi Cpr. Ross del., . . . l."» 86-81*. Ischii.,rliit«.n acrior Cpr. Ross del., . . . «:i 90, Cyanoplax hipunrtatus Sowb. Conch. 111., . . .46 PLATE 15. 91, 93. Ischnochiton conspicuus Cpr. Ross del., . . . J63 92, 96. Ischnochiton conspicnus Cpr. Piisbry del., . . 63 94, 95. Ischnochiton conspicuus Cpr. Emerton del., . . 63 97. Ischnochiton conspicuus var. solidus Cpr. Emerton del., 64 98, 100. Ischnochiton magdalenensis Hds. Ross del., . . 62 PLATE 16. 1, 2. Ischnochiton alatus Sowb. Emerton del., . . .60 3, 4. Ischnochiton alatus Sowb. Piisbry del., . . .60 5. Ischnochiton alatus Sowb. Ross del., . . .60 6-8. Ischnochiton juloides Ad. P. Z. S., .... 55 9, 10. Ischnochiton limaciformis Sowb. Ross del., . . 57 11, 12. Chiton productus Rv. (=1. limaciformis). Conch. Icon 57 13, 14. Chiton sanguineus Rv. (=1. limaciformis). Conch. Icon., 57 15, 16. Ischnochiton limaciformis Sow. Conch. Icon., . . 57 17, 18. Ischnochiton fallax Cpr. Emerton del., . . .59 PLATE 17. 19, 20. Ischnochiton floridanus Pils. Ross del., . . .58 21, 22. Ischnochiton floridanus Pils. Piisbry del., . . 58 23, 23. Ischnochiton purpurascens Ad. Ross del., . . 58 24. Ischnochiton purpurascens Ad. Emerton del., . . 58 25 26. Ischnochiton pectinatus Sowb. Ross del., . . .64 27, 28. Ischnochiton pectinatus Sowb. Emerton del., . . 64 29. Ischnochiton pectinatus Sowb. Piisbry del., . . .64 30. Chiton acutiliratus Rv. (— I. pectinatus Sowb.). Conch. Icon., . 64, 65 32, 33. Ischnochiton viridulus Couth. U. S. Exped., . . 141 39. Chsetopleura hennahi Gray. Piisbry del., . . . 29 PLATE 18. 35-39. Ischnochiton tridentatus Piisbry. Piisbry del., . 140 40. Ischnochiton trifidus Cpr. Cpr. del. (see appendix), . 141 41-46. Ischnochiton regulari^ Cpr. Emerton del., . .142 22 338 EXPLANATION OF PLATES. 47,48. Ischnochiton dispar Sowb. Conch. Icon., . . .111 4'.), 50. Ischnochiton inquinatiu Rve. Conch. Icon., . . 90 51-55. Ischuochiton adamsii Cpr. Pilsbry del., . . .111 56, 57, 59. Ischnochiton australis Sow. Pilsbry del., . .144 58. Ischnochiton australis Sow. Conch. Icon., . . .144 PLATE 19. 60, 61. Ischnochiton tigrinus Krauss. Siidafrik. Moll., . 143 62, 63. Ischnochiton tigrinus var. unicolor Pils. Pilsbry del., . . 143, 144 64-66. Ischnochiton hakodadensis Cpr. Pilsbry del., . 147 67. Ischnochiton novoehollandiit Gray. Pilsbry del., . . 145 68. Ischnochiton noviehollandite Gray. Ross del., . . 145 69. Ischuochitou novBedollandirc Gray. Conch. Icon., . . 145 70-74. Ischnochiton albrechti Schrenck. Amurl. Moll., . 147 PLATE 20. 1-4. Ischnochiton rissoi Payr. Bull. S. Mai. ItaL, . .102 5-7. Ischnochiton rissoi Payr. (young). Bull. S. Mai. Ital., 102 8-10. Ischnochiton rissoi var. meneghinii. Journ. Conch., . 103 11. Ischnochiton yerburyi Smith. P. Z. S., . . . . 101 12, 3, 14, 15. Ischnochiton oniscus Kr. Siidaf. Moll, . 100 16, 17. Ischnochiton reticulatus Rv. Conch. Icon., . . 101 18, 19. Ischnochiton pertusus Rv. Conch. Icon., . . . 103 20. Ischnochiton striolatus Gray. Conch. Icon., . . . 105 21-24. Ischnochiton striolatus Gray. Ross del., . . . 105 25, 26. Ischnochiton caribreorum (Cpr.) Smith (=1. striola- tus). J. Linn. Soc., 107 PLATE 21. 27, 28. Ischnochiton pruinosus Gld. U. S. Expl. Exped., . 109 29-34. Ischnochiton imitator Smith. P. Z. S., 116 35, 38. Ischnochiton punctulatissimus Sowb. Conch. 111., . 115 36, 37. Ischnochiton punctulatissimus Sowb. Pilsbry del., .115 39. Ischnochiton interstinctus Gld. Pilsbry del., . .119 40, 41. Ischnochiton papillosus Ad. Ross del., ... . 114 42-46. Callistochiton shuttleworthianus Pils. Pilsbry del., . 273 47, 48. Ischnochiton catenulatus Sowb. Conch. Illust., . 110 49. Ischnochiton roseus Sowb. Conch. Icon., . . .113 50. Ischnochiton roseus Sowb. Conch. Illustr., . . .113 51. 52. Ischuochiton colubrifer Rve. Conch. Icon., . . 95 •r> •'). Ischnochiton rugulatus Sowb. Beechey's Voy., . .110 54-56. Ischnochiton rugulatus Sowb. Couch 111., . .110 57. Ischnochiton rugulatus Sowb. Conch. Icon., . . .110 i. \I-I\N \ i [OH OF PLJ I'I.M i: 22. 58, [sohnochiton loDgioymba Q. db Q, K'"- del., . . 87 [•chnochiton loDgicymba Q. <& G. A-tn.l.. . . .87 <;o-i;»;. Isrimorhit.m longicjmbfl o. A GK I'iUi.rv del., . 87 Kshnoohiton huddoni I'ik I'ilsb.-y del., . 88 68,70,71. C. longicrmba Sow. ( I. haddoni I'ik;. Conch. 111.. . . ... 69. C. loiiLrirymhu live. (=1. haddoni I'ils.). Conch. Icon., . 74. Ischnochiton divi-ri^'ns Rve. Pilsbry del., . . .90 75,76. Ischnochiton divergens Rve. Ross del., 77. Ischnochiton divergens Rve. Conch. Icon., . . .90 PLATE 23. 78. 80. Ischnochiton fruticosus Old. U. S. Ex. Exped., . 91 79. Ischnochiton fruticosus Gld. Pilsbry del., . . .91 81, 82. Ischnochiton contractus Rve. Conch. Icon., . . 93 83, 84. Ischnochiton decussatus Rve. (=contractus). Conch. Icon.. ......... 93, 94 85. Ischnochiton exiguus Sowb. Conch. Illustr., . . .98 86. Ischnochiton exiguus Sowb. Conch. Icon., . . .98 87. 88. Ischnochiton castus (—contractus). Conch. Icon., 93, 94 89, 90. Ischnochiton sculptus Sowb. Conch. Illustr. . . 92 91. Ischnochiton pallidus Rve. Conch. Icon., . . .89 92,93. Ischnochiton petaloides Gld. U. S. Exped., . .118 94, 95. Ischnochiton carinulatus Rv. Conch. Icon., . . 96 96, 97. Ischnochitou pallidulus Rv. Couch. Icon., . . 95 PLATE 24. 98, 99. Ischnochiton crispus Rve. Conch. Icon., . . .89 100, 1-4. Ischnochiton ustulatus Rve. Emerton del., . . 96 o. Chiton granulosus Frembly. Zool. Journ., . Appendix. 6. Liolophura curtisiana Smith. ' Alert ' Zool., . . . '24- 7, 8. Ischnochiton adelaidensis Rve. Conch. Icon., . .136 9, 10. Ischnochiton muscarius Rve. Conch. Icon., . .132 11, 12. Ischnochiton ustulatus Rve. Conch. Icon., . . 96 13-15. Ischnochiton tessellatus Q. & G. Astrol., 16, 17. Ischnochiton arbutum Rve. Conch. Icon., . .139 18, 19. Ischnochiton milleri Gray. Conch. Icon., . . . 137 20-22. Ischnochiton cariosus Cpr. var. subcariosus Pils. Pilsbry del., ....... 65, 67 23. Ischnochiton cariosus Cpr. typical. Emertou del., . . 65 PLATE 25. 1-10. Ischnochiton dalli Haddon. Chall. Rep ..... 133 11-19. Ischnochiton dorsuosus Haddon. Chall. Rep., . . 135 340 i:\l-LANATION OF PLATES. PLATE 26. 20, 21. Ischnochiton mertensii Midd. Ross del., . . . 125 22, 24-26. Ischnochiton mertensii Midd. Pilsbry del., . 125 23. Ischnochiton mertensii Midd. Emerton, . . .125 27. Ischnochitou cooperi Cpr. Ross del., . . . .127 28-30. Ischnochiton cooperi Cpr. Pilsbry del., . . . 127 31-33. Ischnochiton clathratus Rve. Pilsbry del, . . 128 34. Ischnochiton clathratus Rve. Emerton del., . . . 128 PLATE 27. 35-39. Ischnochiton lindholmi Schr. Amurl. Moll., . . 85 40-43. Ischnochiton cyaneopunctatus Kr. (=lentiginosus Sowb.) 8uda£Moll., 135 44. Ischnochiton lentiginosus Sowb. Conch. 111., . . . 135 45, 46. Ischuochiton versicolor Sowb. Conch. Illustr., Appendix. 47, 48. Ischnochiton pulcherrimus Sowb. Conch. Icon., . 130 49. Ischnochiton constant! Velain. Arch. Z. Expe>., Appendix. 50. Ischnochiton coreanicus A. & R. Conch. Icon., . .129 51. Ischnochiton bergoti Velain. Arch. Z. Expe*r., Appendix. 52-54. Ischnochiton inca Orb. Voy. Amer. M£rid., Appendix. PLATE 28. 1-4. Chiton sulcatus Wood. Ross, del., . . . .191 5-8. Chiton goodalli Brod. Ross, del., . . . .191 PLATE 29. 9. Chiton goodalli Brod. Conch. Icon., .... 191 10. Chiton barnesi Sowb. Conch Icon., .... 190 11,12. Chiton barnesi Sowb. Pilsbry del., , . .190 13, 14. Chiton (?) dimorphus Rochebr. Miss. Cap Horn. (See appendix). 15-21. Chiton murrayi Haddon (?— C. pusio Sowb., p. 133). Chall. Rep., . .161 PLATE 30. 23. Chiton magnificus Desh. Ross del., . . . .160 24. Chiton magnificus Desh. Emerton del., . . . .160 25. Chiton stokesii Desh. Conch. Icon., .... 165 2(>. Chiton stokesii Desh. Original, 165 27. Chiton granosus Frenab. Pilsbry del., . . . .167 28. Chiton granosus Fremb. Zool. Journ., .... 167 29. 31. Chiton cumingi Fremb. Conch. Icon., . . .164 30. Chiton cumingi Fremb. Ross del., .... 164 i MM. \N \ i IMS .,i i-i • :;il PLATE 81, !. Chiton PUftidU D.'-h. Moll. K.'iiri., . . 186 8, ( 'liiton lyratns Sowb. C-.nch. Iron 184 37, 38. Chiton anguttiooftatai Q. v -1 187 :;•.», in. Chiton mftorititnafl Voy, Voy. Astro].. . . 188 II, I'J. Chiton oaptMisis Gray (— nigroviivns I>lv.). Conch. Icon., ...... . 43. Chiton cymbiola So\\l>. ( tulipa (,).). Conch. Icon., 44, 46, 47. Chiton tulip* Quoy. KOSH del., . . . .185 46. Chiton tulipa Quov. Voy. Astrol. 185 48, 49. Chiton cymbiola Sowb. (^tulipa Q.) ... 185 PLATE 32. 50. Chiton patulus Brod. (—stokesii Brod.). Conch. Icon., !•;."> 51-52. Chiton stokesii Brod. Pilsbry del., . . . . I'M 53. Chiton stokesii Brod. (1 sq. mm. of girdle indicated), I'.lsbrydel., 165 54. Chiton virgulatus Sowb. Conch. Icon., .... IHO 55. 56. Chiton virgulatus Sowb. Pilsbry del., . . . 166 57. Chiton albolineatus Sowb. Conch. Illustr., . . . 160 PLATE 33. 58, 59, 60. Chiton tuberculatus L. Ross del., . . .153 61. Chiton tuberculatus var. assimilis Rv. Conch. Icon., . !">"> 62. Chiton tuberculatus var. assimilis Rv. Ross del., . . 155 63. Chiton tuberculatus var. assimilis form ater. Ross del., 155 64. Chiton foveolatus Sowb.) (•— viridis Spengl.). Conch. Icon., . . . 156 65. Chiton viridis Spengl. Ross del., !•">»> 66 67. Chiton viridis Spengl. Pilsbry del., .... 156 PLATE 34. 68. Chiton lievigatus var. arfciculatus Sowb., ventral view. Emerton del., 1">9 69. Chiton laevigatus var. articulatus Sowb. Conch. Icon., . 159 70. Chiton Isevigatus var. articulatus Sowb. interior. Pilsbry del., . . . . . . . . . 169 71. Chiton Isevigatus Sowb., typical. Conch. Icon., . . 159 72. 74. Chiton marmoratus Gmel. Ross del., . . .158 73. Chiton marmoratus Gmel. Conch. Illustr., . . . l.~>s 75. Chiton marmoratus Gmel., interior. Pilsbry del., . . 1">* 76. Chiton marmoratus Gmel. Conch. Icon., . . . 158 77-79. Chiton canariensis Orb. Moll. Canar., . . .184 PLATE 35. 80. Chiton marmoreus Rv. (=squamosus L.). Conch. Icon., 155 81. Chiton s«iuamosus L., one-half valve. Pilsbry del., . !">"> 342 i:\ri.\NATIONOFPLATE8. 82. Chiton squaruosus L. Ross del., 155 83,84. Chiton insularis Rochebr. Nouv. Arch., . . . 183 85, 86. Chiton hamyi Hochebr. Nouv. Arch., . . .183 87, 88, 90. Chiton o'livaceus Speng. Pilsbry del., . . 180 89, 91,92. Chiton olivaceus Speng. Ross del., . . .180 93. Chiton affinis Issel. Savigny, 181 PLATE 36. 91. Chiton jugosus Gould. U. S. Exped., . . . .178 92. 94, 95. Chiton jugosus Gould. Pilsbry del., . . . 17K 93. Chiton jugosus Gould. Ross del., 178 96, 97. Chiton jereus Rve. Conch. Icon., . . . .179 98, 99. Chiton marquesanus Pils. Pilsbry del., . . . 170 100. Chiton marquesanus Pils. Ross del., . . . .170 1. Chiton sinclairi Gray. Erebus & Terror, . . . 174 2, 3. Chiton sinclairi Gray. Pilsbry del., . . . .174 4,6. Chiton canaliculatus Q. Pilsbry del., . . .177 5. Chiton insculptus Ad. (—canaliculatus Q.). P. Z. S., . 177 PLATE 37. 6. Chiton quoyi Desh. (color var.). Ross del., . . .172 7. Chiton quoyi Desh. (sculpture) Pilsbry del., . . . 172 8. Chiton quoyi Desh. Conch. Icon., . * . . . . 172 9. 10. Chiton caliginosus Rve. Conch. Icon., . Appendix. 11. Chiton dissimilis Rve. Conch. Icon., .... 184 12, 13. Chiton muricatus Ad. P. Z. S., . . . .175 14, 15. Chiton pellisserpentis Q. Ross del., . . .173 16. Chiton pellisserpentis Q. Astrol., . . . .173 17. Chiton pellisserpentis Q. (1 sq. mill, of the girdle indicated). Pilsbry del 173 18. Chiton pellisserpentis Q. Emertou del., . .173 PLATE 38. 19. Chiton subfuscus Sowb. typical. Conch. Icon., . 162, 163 20. Chiton subfuscus var. mesoglyptus Pils. Conch. 111., . 164 22. Chiton subfuscus var. mesoglyptus Pils. Ross del., . 164 21. Chiton subfuscus var. mesoglyptus, valve of same specimen as fig. 22. Pilsbry del. 164 23. Chiton bowenii King. Conch. Illustr., . . . .164 •J4-26. Ischnochiton sulcatus Q. & G. Voy. Astrol., . . 138 27, 28. Chiton tenuistriatu* Sowb. Conch. 111., . . . 188 29, 30. Chiton cingillatus Rve. Conch. Icon., . Appendix. 31, 32. Chiton luzonicus Rve. Conch. Icon., . Appendix. 33,34. Chiton aquatilis live. Conch. Icon., . 169 PLATE 39. 35. Tonicia disjunct:! Fremb. Conch. Icon.. . . . 212 \ N \ TIMS 01 PI LTBB. 36—11. Tonicia disjunct* I-'n-mh. Kmcrton n l:i<| uc;it u> Sli ul (. Kinrrtoii del., 52. [iohnooniton ragulatui Sowb var, Condi. Iron., . . no PLATE 40. 1,2. Tonieia truncate Sowb. Condi. Icon., . . . LMI .3,4. Tonioia fortilirate Sowb. Condi. Icon., . . . _<>7 5,6. Tonirin j»ii'ta So\vh. Conch. Icon., . . . .211 7. Tonicia carpenteri Angas. P. Z. S., .... iio.s 8-11. Tonicia lamellosa Q. & G. Voy. Astrol., . . ,209 12. Tonicia /sdumi I'flr. Moll. S. Georg., . . . ,204 13-15. Tonieia tehuelchus Orb. Voy. Ame>. Me*rid., . . 205 16, 17. Tonieia suezensis Rve. Conch. Icon., . . . 206 PLATE 41. 19. Tonieia chilensis Fremb. Pilsbry del., . . . . l'.»7 20. Tonieia chilensis Fremb. Conch. Icon., . . . .197 21. Tonicia fastigiata Sowb. Pilsbry del, . . . .199 22. Tonieia elegans Fremb. Pilsbry del., . . . .196 Betw. 22 and 24. Touicia elegans Fremb. (color-pattern only). Pilsbry del., ........ . ]S6 24. Tonieia elegans Fremb. (second valve). Pilsbry del., . 196 25. Tonieia lineolata Fremb. Conch. Icon., . . . .198 26. Tonieia lineolata Fremb. Zool. Journ., .... 198 27. Tonieia lineolata (var. connecting with elegans). Ross del., .......... 198 28. Tonieia atrata Sowb. Conch. 111., . . . .201 29. 30. Tonieia atrata Sowb. Conch., Icon., . . .201 PLATE 42. 31. Tonieia elegans Fremb. Ross del., . . . .196 32. Tonieia elegans Fremb. var. Conch. Icon., . . .196 33. 34, 35. Tonieia elegans Fremb. (not typical). Emerton, del., ....... . . .196 36-39. Tonieia fastigiata Gray. Conch. Icon, . . .199 40. Tonieia chilcensis (=fastigiata). Conch. Icon., . .199 PLATE 43. 41. Tonieia swainsoni Sowb. Conch. Icon., .... 201 42. Tonieia swainsoni Sowb. Pilsbry del., .... 201 4.'>. Tonieia swainsoni Sowb. Ross del., .... 201 44, 45. Tonieia granifera Sowb. Conch. Icon., . . . 200 46, 47. Tonieia grayi Sowb. Conch. Icon., .... 200 48, 49. Tonieia (?) martieli Rochebr. Moll. Cap Horn, . 203 50, 51. Tonieia horniana Rochebr. Moll. Cap Horn, . . 203 52, 53. Tonieia lebruni Rochebr. Moll. Cap. Horn, . . 203 344 EXPLANATION OF PLATES. 54,55. Tonicia sch ram mi Shuttle w. Pilsbry del., . . 205 56, Tonicia schrammi Shuttlew. Journ de Conch., . . 205 PLATE 44. 57, 60. Chaetopleura watsoni Sowb. Conch. Icon., See appendix. 58, 59. Chsetopleura watsoni Sowb. Conch. 111., See appendix. 61. Chaetopleura castanea Q. Voy. Astrol., . See appendix. 62. Chaetopleura fulva Wood. Ross, del., . . See appendix. 63. Chsetopleura fulva Wood. Conch. Icon., . See appendix. 64. Chaetopleura fulva Wood. Pilsbry del., . . See appendix. 65. 67. Tonicia rubridens Pils. Pilsbry del., . . .202 66. Tonicia rubridens Pils. Ross del., 202 68. Craspedochiton laqueatus Sowb. Conch. Icon., . . 285 PLATE 45. 69, 70. Tonicia crenulata Sowb. Conch. Icon., . . 195 71, 72. Tonicia crenulata Sowb. Ross del., . . . 195 73. Chiton rubicundus Costa. Catal., .... 182 74, 75. Chiton pulchellus Phil. (=rubicundus Costa). Enum. 182 76, 77. Acanthopleura borbonica Dh. Pilsbry del., . 230 78, 79. Acanthopleura borbonica Dh. Moll. Reun., . 230 80, 81, 83, 84. Acanthopleura spinosa Brug. (valves i, ii, viii) Emerton del., 220 82, 87. Acanthopleura spinosa Brug. (valve iv). Pilsbry del., 220 85. Acanthopleura spinosa Brug. Conch. Icon., . . . 220 86. Acanthopleura spiuosa Brug. (girdle spines). Emerton del., .... 220 PLATE 46. 88. Eudoxochiton nobilis Gray (type). Erebus & Terror, . 193 89, 90. Eudoxochiton nobilis Gray (valve vii). Pilsbry del., 193 91. Eudoxochiton nobilis Gray (interior). Emprton del., . 193 92-94. Eudoxochiton nobilis Gray (valve viii). Pilsbry del., 193 95. Eudoxochiton nobilis Gray. Pilsbry del., ; . .193 96, 100. Eudoxochiton huttoni Pils. (valve vii). Pilsbry del., 194 97. Eudoxochiton huttoni Pils. Ross del., .... 194 98, 99. Eudoxochiton huttoni Pils. (valve viii). Pilsbry del., 194 1-5. Chiton miles Cpr. Emerton del., . . . 188 PLATE 47. 6-9, 11-14. Acanthopleura echinatum Barnes. Emerton del., 218 10. Acanthopleura echinatum Barnes. Zool. Journ., . . 218 15-17. Acanthopleura echinatum (young). Emerton del., . 218 18-20. Acanthopleura brevi>pin<»>:i >|)l(Mira spiniger Sowb. (Interior, and posterior valv,-). 1'ilsbry del., . .221 27. Acanthoploiira spiniger Sowb. Conch. Icon., . .221 28. Acanthopleura spiniger var. granata Rv. Pilsbry del., 224, [225 29. 30. Acanthopleura spiniger var. granata Rv. Conch. Icon., . . . . . . . . . 224, 225 31. Acanthopleura spiniger var. (Viti Is.) Ross del., . . 223 32. Acanthopleura spiniger var. (Viti Is.). Pilsbry del., . 223 PLATE 49. 33,34. Acaiithopleura spiniger var. cunninghami Rve. Conch. Icon 225 35, 36. Chiton linter (Chemn.) Rve. Conch. Icon., (See appendix.) 37, 38. Chiton piceus Rv. not Linn. (=A. spiniger var. obesa Shuttl.) . .226 PLATE 50. 39. Acanthopleura granulata Gmel. (St. Thomas). Ross del., 227 40, 41. Acanthopleura granulata Gmel. (group of white and of dark spines). Pilsbry del., 227 42. Acanthopleura granulata Gmel. (occidentalis Reeve). Conch. Icon., 227 43. Acanthopleura granulata (Key Vaccas, Fla.). Ross del., 227 44-47. Acanthopleura granulata Gmel. (St. Domingo). Pilsbry del., 227 48. Acanthopleura granulata Gmel. (St. Thomas). Ross del., 227 49. Acanthopleura granulata Gmel. Emerton del., . . 227 PLATE 51. 1. Schizochiton incisus Sowb. 235 2. Schizochiton incisus Sowb. (half of head valve). O. J. M. S., . 235 3. Schizochiton incisus Sowb. (eye, x 200). Q, J. M. S., . 235 4-5. Schizochiton incisus Sowb. (valves i and ii). Emerton del., 235 6-8. Schizochiton incisus Sowb. (valve viii, ventral, profile and posterior views). Emerton del., .... 235 9-12. Lorica angasi Ad. & Ang. Emerton del., . . . 238 346 I : X I -LANATION OF PLATES. PLATE 52. 14. Lorica cimolea Rv. (=volvox Rve.). Conch. Icon., . 237 15. Lorica volvox Rve. Ross del., 237 16. Lorica volvox Rv. (1 sq. mill, of girdle). Pilsbry del., . 237 17. 18. Lorica volvox Rv. (posterior valve). Pilsbry del., . 237 19, Lorica volvox Rv. (anterior valve). Pilsbry del., . . 237 20, 21. Lorica volvox Rv. (intermediate valve). Pilsbry del., 237 22, 23. Enoplochiton niger Barnes (posterior valve). Emer- ton del., 252 24, 25. Enoplochiton niger Barnes (intermediate valve). Pilsbry del., . . . . .252 26. Enoplochiton niger Barnes. Ross del., .... 252 27. Enoplochiton niger (surface). Q. J. M. 6., . . . 252 28. Enoplochiton niger (surface). Q. J. M. S., . . 252 29. Enoplochiton niger (girdle of a young specimen). Emer- ton del., 252 PLATE 53. 30. Liolophura iucanaGld.(=L. gaimardi Blv.). U. S. Expl. Exped., 240 31. Liolophura gaimardi Blv. (girdle spines). Pilsbry del., . 240 32. Liolophura gaimardi Blv. Ross del., .... 240 33-35. Liolophura gaimardi Blv. Pilsbry del., . . .240 36-40. Liolophura georgiana Q. & G. Voy. Astrol., . . 241 41. Liolophura japonica Lisch. (Girdle spines). Pilsbry del., 242 42. Liolophura japonica Lisch. Ross del., .... 242 43. 44. Liolophura japonica Lisch. Jap. Meeres-Conch., .242 45. Liolophura japonica var. tessellata Pils. Ross del., 46. Liolophura japonica var. tessellata Pils. Pilsbry del., . 243 PLATE 54. 21, 22. Nuttallina scabra Rv. Pilsbry del., . . . .280 •2 :;, 24. Nuttallina californica Nutt. Pilsbry del., . . 279 25-27. Nuttallina alternataSowb. Conch. 111., . . .281 28-30. Nuttallina cinerea Poli. Emerton del., . . . 283 31. Nuttallina cinerea Poli (edge of girdle x 100). Pilsbry del., 283 32. Nuttallina cinerea Poli. Test. Utr. Sic., . . . .283 33. Nuttallina cinerea Poli (girdle x 50 ca.) Pilsbry del., . 283 34. 35. Plaxiphora ovata Hutt. Pilsbry del., . ' . .332 36-39. Plaxiphora ovata Hutt. (profile, posterior, dorsal and ventral views of posterior valve). Pilsbry del., . . 332 40. Plaxiphora ovata Hutt. (sculpture of intermediate valves). I'ilsbrydel., 332 41-45. O. caliginosus Cpr. (=Liolophura japonica Lisch.) Emerton del., . 244 46. Onithochiton amicorum Bd. Voy. Curacoa, . . .249 i \I-I.\N M i«. N MI- PLJ * l'l.\ I ! 1. Onjthocbiton lyellii 8owb. ('..ndi. IIIu*tr 247 2. Onitbocbiton lyelli) Sowb. Condi. Icon., . . . LM? 3-7. Onitbocbiton lyellii 8owb, Bmerton del., . . .247 8,9. Onithodiiton iiidi IIv. ( lydlii S.»w!).). Conch. Icon., 248 10, 11. Onithudiitoii srmisnrlptus Pils. Koss del., . ,247 12, 13. Onithudiitoii <|iirrdmis(;l7 12-16. Nuttallina californica Nutt. Emerton del., . . 279 17, 18. Nuttallina californica Nutt. Ross del., . . .279 19, 20. Nuttallina scabra Rve. Ross del., . . . .280 PLATE 57. 21. Dinoplax gigas Gmel. Conch. Icon., .... 255 22. 27-31. Dinoplax gigas Gmel. Emerton del., . . . 255 23-26. Dinoplax gigas Gmel. (young). Siidafrik. Moll., . 255 32. Dinoplax gigas Gmel. (young). Ross del., . . . 255 33. 35. Tonicia confossa Gld. Pilsbry del., . . . .210 34. Tonicia confossa Gld. U. S. Expl. Exped., . . .210 PLATE 58. 1, 2. Callistochiton crassicostatus Pils. Emerton del., . . 264 3-6. Callistochiton crassicostatus Pils. Pilsbry del., . . 264 Fig. below 1, and 7, 8. Callistochiton palmulatus Cpr. Emerton del., . . . . . . . . . .262 9-11. Callistochiton palmulatus var. mirabilis Pils. Pilsbry del., 263 12. Callistochiton palmulatus (typical). Pilsbry del., . . 262 13-16. Callistochiton palmulatus (typical). Emerton del., . 262 17. Callistochiton decoratus Cpr. Ross del., . . . 269 18-20. Callistochiton decoratus Cpr. Pilsbry del., . . 269 21, 22. Plaxiphora ccelata Rve. Conch. Icon., . . .328 PLATE 59 21-26. Callistochiton pulchrior Cpr. (=pulchellus Gray). Foord del., . . 272 348 EXPLANATION OF PLATES. 27, 28. Callistochiton elenensis Sowb. Conch. 111., . . 267 29, 34. Callistochiton antiquus Rv. Pilsbry del, . . . 274 30-32. Callistochiton antiquus Rv. Emerton del., . . 274 35. Callistochiton antiquus Rv. Conch. Icon., . . . 274 36. Callistochiton coppingeri Sm. ' A'lert ' Zool., . . . 275 •".7-42. Callistochiton infortunatus Pils. Foord, del., . . 266 43, 44. Callistochiton bicostatus Orb. (=pulchellus Gray). V,,y. Am. Mrr., 272 45. Callistochiton adenensis Smith. P. Z. S., . . .278 PLATE 60. 1. Callistochiton pulchellus Gray. Spicil. Zool., . . . 271 2. Callistochiton pulchellus Gray. Conch. Icon., . . 271 3-6. Callistochiton pulchellus Gray. Pilsbry del., . .271 7-10. Callistochiton gabbi Pils. Pilsbry del., . . ,270 11-15. Callistochiton (?) heterodon Pils., . . ... 276 16. Callistochiton (?) heterodon var. savignyi Pils. Savig. ^Egypt, . 277 PLATE 61. 17-22. Callistoplax retusus Sowb. Emerton del., . . 288 23, 24. Callistoplax retusus Sowb. Emerton del., . . . 288 25. Callistoplax retusus Sowb. Conch. Illustr., . . . 288 26. Callistoplax retusus Sowb. Conch. Icon., . . . 288 27-32. Angasia tetrica Cpr. Emerton del., .... 287 33. Ceratozona rugosa Sowb. Conch. 111., .... 290 34. Ceratozona rugosa Sowb. (Santa Cruz). Pilsbry del., . 290 35. Ceratozona rugosa Sowb. Pilsbry del., . . . . 290 36. Ceratozona rugosa Sowb. (Jupiter Inlet). Pilsbry del, . 290 37. Ceratozona guildingii Rv. (r=rugosa Sowb.) Conch. Icon., 290 38. 39. Ceratozoua setosa Sowb. Emerton del., . . .292 40. Ceratozona setosa Sowb. Conch. 111., . , ... 292 41-45. Ceratozoua rugosa Sowb. Emerton del., . . . 290 PLATE 62. 84, 85. Placiphorella stimpsoni Gld. (tail valve). Pilsbry del. 307 86. I'hiriphon-lhistimpsoiii Gld. (girdle- hair). Carpenter del. 307 87. Placiphorella stimpsoni Gld. Ross del., . . 307 88-92. Mopalia middendorffii Schr. Amurl. Moll., . 301 93. Mopalia mii.-c<>-a var. porifera Pils. Pilsbry del., . 297 94. Mopalia muscosa var. porifera Pils. Ross del., . 297 95. Mopalia sinuata Cpr. (girdle). Emerton del., . 303 96 (upper fig.). Mopalia sinuata Cpr. Ross del., . 303 96 (lower three figs.'. M"|»;ilia sinuata Cpr. (tail valve) Emerton del 303 i AIM \v \ i [OH OF I'LVTES. 349 97. M«»pali:i >imint:i < 'pr. < intrnin-di:it»- v;,lvr ). I'iUbry d«-l . J».S. Mopalia imporcata ('pr. (intermediate valve). i'ilsbrv del ... 99. Mopalia muscosa var. liindsii I'.d. I'iUhry del., 100. Mopalia muscosa var. liindsii P,d. Ro.ss del., . . . li'.MI PLATE 63. 46. Mopalia musi-osa ( ild. (typical). U. S. Expl. Exped., . 47,48. Mopalia museosa Gld. Ross del., .... 295 49-50. Mopalia muscosa Old. Emerton del., . . . 295 57. Mopalia muscosa var. hindsii Bd. Conch. Icon., . . 296 58, 59. Mopalia lignosa Gld. Ross del., .... 299 60. Mopalia lignosa smooth form. Ross del., . . . 300 61. Mopalia lignosa smooth form. Pilsbry del., . . . 300 62. Mopalia lignosa (vespertina Gld.). U. S. Ex. Exped., . 300 63. Mopalia insignis Newc. (=lignosa Gld.) 300 PLATE 64. 64-68. Mopalia ciliata Sowb. (Monterey Bay). Ross & Pilsbry del., . . . . . . . .303 69,70,71. Mopalia ciliata var. wosnessenkiiMidd. Mai. Ross. 305 72. Mopalia ciliata var. wosnessenskii Midd. Pilsbry del., . 305 73. Mopalia ciliata var. wosnessenskii Midd. Ross del., . 305 , 74. Mopalia muscosa Gld. Emerton del., .... 295 75. Mopalia acuta Cpr. Ross del., 297 76-79. Mopalia acuta Cpr. (tail valves). Pilsbry del., . . 297 80, 81. Mopalia plumosa Cpr. (=racuta Cpr.). Foord del., . 298 82, 83. Mopalia lignosa form elevata. Ross del., . . . 300 PLATE 65. 73-75. Plaxiphora atlantica V. (tail valve). Pilsbry del., . 313 7H. Plaxiphora setiger King. Conch. Icon., . . .316 77, 78, 79. Plaxiphora setiger King. Emerton & Ross del., 316 80-82. Plaxiphora egregia Ad. P. Z. S., ... 331 PLATE 66. 6, 7. Placiphorella velata Cpr. Emerton del., . . . 306 8-10. Placiphorella velata Cpr. (posterior valve). Pilsbry del., .... ..... 306 11. Placiphorella velata Cpr. (intermediate valve). Pilsbry del., 306 12. Placiphorella velata (Insertion-plate, seen from end of valve). Pilsbry del., 306 13. Placiphorella velata (girdle-hair). Pilsbry del., . . 306 14. Placiphorella borealis Pils. (intermed. valve). Pilsbry del., 309 .0>.")n i:\ri.\NATION OF PLATES. 1 .", Placiphorella borealis Pils. (Insertion-plate seen from end of valve). Pilsbry del, 309 16, 17. Placiphorella borealis Pils. (posterior valve). Pilsbry del, 309 18-24. Placophoropsis atlantica V. Tr. Conn. Acad., . . 313 25. Placiphorella petasus Rv. Conch. Icon., . . .311 26, 27. Placiphorella blainvillii Sowb. Conch. Icon., . . 310 28-32. Placiphorella blainvillii Sowb. Emerton del., . .310 PLATE 67. 33-36. Plaxiphora carpenteri Had. Chall. Rep., . . 325 S8. Cha-topleura hahni Rochebr. (=Plaxiphora fremblyi) B. Cap Horn, 39, 40. Chietopleura frigida Rochebr. (=Plaxiphora setiger, young). Miss. Cap Horn, 317 41, 42. Chietopleura savatieri Rochebr. (= Plaxiphora setiger) Miss. Cap Horn, 317 43-46. Plaxiphora simplex Cpr. Chall. Rep., PLATE 68. .">l-54. Plaxiphora biramosa Q. & G., Voy. AstroL, . . 319 55-61 . Plaxiphora superba Cpr. (=biramosa Q.). Emerton del. 319 62, 64. Plaxiphora petholata Sowb. Pilsbry del., . . 323 63, 66. Plaxiphora petholata Sowb. Emerton del., . . 323 65. Plaxiphora petholata Sowb. Ross, del., . . . 323 67. Plaxiphora petholata Sowb. Conch. Illustr., . . . 323 68-72. Plaxiphora glauca Q. & G. Voy. AstroL, . . 326 NOTE.— The Parts of Vol. XIV of the MANUAL were issued to subscribers upon the following dates : Part 53, including pp. 1- 64, plates 1-15, July 25, 1892, Part 54, " " 65-128, " 16-30, Nov. 25, 1892. Part 55, " "129-208, " 31-40, Feb. 25, 1893. Part 56, " " 209-350, " 41-68, June, 1893. The Title page, Preface and Introduction to Polyplacophora, accompany Part tffl. J"^ & END OF VOL. XIV. POLYPLACOPHORA. PLATE 1 o'o k> t>t»"\ , >>>* o j > :J: J J ,*** io»>««~r'1" »***> ^J 90 <*""* POLYPLACOPHORA. PLATE 2 POLYPLACOPHORA. PLATE 3 POLYPLACOPHORA. PLATE 4 POLYPLACOPHORA. PLATE 5 POLYPLACOPHORA. PLATE 6 POLYPLACOPHORA. PLATE 7 POLYPLACOPHORA. PLATE 8 84 POLYPLACOPHORA. PLATE 9 91 POLYPLACOPHORA. PLATE 1O POLYPLACOPHORA. PLATE 11 POLYPLACOPHORA. PLATE 12 POLYPLACOPHORA. PLATE 13 POLYPLACOPHORA. PLATE 14 86 POLYPLACOPHORA. PLATE 15 POLYPLACOPHORA. PLATE 16 POLYPLACOPHORA. PLATE 17 19 POLYPLACOPHORA. PLATE 18 POLYPJLACOPHORA. PLATE 19 1 63 POLYPLACOPHORA. PLATE 20 .;] 24- POLYPLACOPHORA. PLATE 21 POLYPLACOPHORA. PLATE 22 74- POLYPLACOPHORA. PLATE 23 PLATE 24 POLYPLACOPHORA. I POLYPLACOPHORA. PLATE 25 POLYPLACOPHORA. PLATE 26 I 34 POLYPLACOPHORA. PL. ATE 27 POLYPLACOPHORA. PLATE 28 POLYPLACOPHORA. PLATK Ib POLYPLACOPHORA. 4^1 PLATE 3O POLYPL.ACOPHORA. PLATE 3! POLYPLACOPHORA. PLATE 32 56 POLYPLACOPHORA. PLATE 33 63 67 POLYPLACOPHORA. PLATE 34 74 POLYPLACOPHORA. PLATE 35 POLYPLACOPHORA. PLATE 36 91 POLYPLACOPHORA. PLATE 37 POLYPLACOPHORA, PLATE 38 33 POLYPLACOPHORA. PLATE 39 POL.YPLACOPHORA. PLATE 40 •JkJ^JLi-.m^* 14 POLYPLACOPHORA. PLATE 41 ...••• • - .. ..-•-• . POLYPLACOPHORA. PLATE 42 J3J 5R» 34 37 POLYPLACOPHORA. PLATE 43 POLYPLACOPHORA. PLATE 44 63 POLYPLACOPHORA. PLATE 45 |P POLYPLACOPHORA. PLATE 46 POLYPLACOPHORA. PI-ATE 47 POLYPLACOPHORA. PLATE 48 POLYPLACOPHORA. PLATE 49 37 POLYPLACOPHORA. PLATE 5O 48 POLYPLACOPHORA. PLATE 51 POLYPLACOPHORA. '-:'i.:i:j. 28 POLYPLACOPHORA. PLATE 53 1mm POLYPLACOPHORA. I - PLATE 54 .! Imin POLYPLACOPHORA. PLATE 55 POLYPLACOPHORA. PLATE 56 POLYPLACOPHORA. POLYPLACOPHORA. PLATE 58 u ^ POLYPLACOPHORA. 1 mm * i 31 3E PLATE 50 26 /27 i lia POLYPLACOPHORA PLATE 6O '* 1mm. POLYPLACOPHORA. PLATE 61 PLATE 62 POLYPLACOPHORA. F 96 N & ^flf POLYPLACOPHORA. PLATE 63 POLYPLACOPHORA. PLATE 64 POLYPLACOPHORA. PLATE 65 78 POLYPLACOPHORA. PLATE 66 ?.(T POLYPLACOPHORA. PLATE 67 K - •:! 44 45 41 J 46 ^U POLYPLACOPHORA ^^w^**.. . 58': 59", 60 51 68 61 • PLATE 68 54- •• g • o rH O * O Z5 CH University of Toronto 0 i-t N rH O Library fc — < H ( )/ *• r2* f/ 10 DO NOT G* « »- / / co aj // H >; J REMOVE j 14 H*^ I THE // o •a! r^ CARD « d (tf A \ 0 FROM \\ ^i 6 \\ o \\ THIS 6 \ C H a s POCKET u « ^ 4 •r «-> — Acme Library Card Pocket Under Pat. "Ref. Index File" Made by LIBRARY BUREAU