Sue i, — ie cea ene Sec erat ne pe Sue VU Wy | WM vo v Av Wd Ne J jw ol ‘é Ne Ned Nd Wid, NUVI WWW Wy pints: ae WM wv MVS swe) J BRN ac NWN Sv yuve vi" TninatteN acc tada Sanaagegggue oe” ow Avie gh SFU V Oge oes yueey JU YY uy Ld \, | : | cc Mdw Will seo anyday hi ve i net cnet seal vat wena M Se cont sveyseestte Nery vou! Sere santa ea iN Wye V UEC ON) WL d\du\ peivigees anes paety jee MeN i? tise usaeunanseialies we ee oe vw win win Wich pease CAMO NaC UM eM sendin raitiyys onal aT iwi i Lieven | SRE Reena Wy vey Juteydee Sg : ATCT vant dAdhigaigs ace MN iieaiteeee it ude oueees Crea yy Wievever nae Neved") NY WWW “cht ee ttu ae ee ANAM) We Aste ue Wig Waiuse aN wae Wn jose At mM" nvrancte yy Wi wwe * ewe Sie dieneaieey wis VJ vie ee oe se Wey ASS we we: View) iv We V Us hh ue Wiis vy Aarne’ dd dye WOON aa nase es WSO wy eNOS N Busy ase SY vay yey Aid Wee error veCvN aes Ay de on iw" uy wi! “nn Maid Even Uva Wiad My w coy pe have 5 ed Y Y WV YOY, UU iy SoU UY Bey Ud vyeyey ewives es YUwUy Wi Wey Ph vv Www si Vv Work a As; ee Uyyy yey ITY wyyry" - USMS US Jy eh Jwyyuyed Core ae Fees, eA. Vic ches hea Giga IN) ONS Shee Piha as ‘coli cl | eh aad 4 tila Be, util 4 Jytgvon oY SUNY” Waitin eee JUy WW vas Weegee Wi raat Csi d swivel : a WM ves aa acu: | Nai : SONU | i Gu MAL Ma WS AW %, in © ie —— ce ermine i eee errata ney ner REPORT ON THE MARINE ISOPODA OF NEW ENGLAND AND ADJACENT WATERS. By OSCAR HARGER. {FROM THE REPORT OF THE UNITED STATES COMMISSIONER OF FISH AND FISHERIES, ParT VI, FOR 1878.] ois p rr? a AS heen 9 ale A > Od it ae igh # Rte XIV. REPORT ON THE MARINE ISOPODA OF NEW ENGLAND AND ADJACENT WATERS. By Oscar HARGER. The following paper includes the species of Isopoda at present known to inhabit the coast of New England and the adjacent regions, as far as Nova Scotia on the north and New Jersey on the south. These limits have been chosen from the fact that nearly all the marine collections of this order made by the Fish Commission have been from the New Eng- land coast, except those from the Nova Scotia coast in 1877, while the commission had its headquarters at Halifax. Previous to the work of the Fish Commission extensive collections had also been made, mostly by Professors A. E. Verrill and 8. I. Smith, of Yale College, in the Bay of Fundy and at other places along the coast as far south as Great Egg Har- bor, in the southern part of New Jersey. The collections thus obtained, and others in the museum of Yale College, have, through the kindness of Professor Verrill, been used in the preparation of this article. As there has not yet, been sufficient opportunity for the study of the Bopyrida, only a list of the known species of that family is included, and for this I am indebted to Professor 8. I. Smith. The species of the remaining fam- ilies are described at length, and nearly all figured in more or less detail in the plates accompanying the article. Throughout the article especial reference will be had to the Isopoda of our own coast, and many pecu- liarities of structure, not found in our genera, will be more or less com- pletely disregarded. As the Oniscide area terrestrial family, only a few species, found usually, or only, along the shore are here included. ISOPODA. This group is an order of Crustacea, so named from two Greek words, ?oos, equal, and zots, a foot, from the general similarity of the legs throughout, all being thoracic. The order belongs to the Tetradecapoda, “fourteen-footed,” called also Edriophthalma, or “‘ sessile-eyed” Crustacea. All of these terms, however, require modification when applied to the animals included in this order, since in the genus Astacilla the anterior pairs of legs are quite unlike the posterior, in Gnathia there are never more than twelve feet, or legs, in six pairs, and lastly in Tanais and its allies the eyes, when present, are not sessile, but articulated with the head, or stalked, as in the higher Crustacea. It may, however, be stated that 297 298 REPORT OF COMMISSIONER OF FISH AND FISHERIES. the relations of the Tanaide with the rest of the order are remote, and it is perhaps doubtful whether they should be retained among the Jsopoda, especially as this family differs from the rest of the order in its mode of respiration, as will be explained hereafter. Although this order is not a large one its representatives are perhaps more widely distributed than in any other order of Crustacea. Every one is familiar with ‘‘sow-bugs” or “pill-bugs,” which are found even in damp houses and in cellars, as well as under leaves in woods or under almost any pile of rubbish among decaying vegetable matter. These terrestrial species do, indeed, become rare in the colder parts of the world, but are found as far north as Greenland. Other species less familiar, but perhaps hardly less abundant, inhabit ponds and streams of fresh water, and others are found along the shores of all oceans; yet others abound among the marine vegetation of the shallow waters, or fix themselves upon the bodies, or within the mouths of fishes and other marine ani- mals. Species are found swimming free in the open ocean, and others are brought up from the greatest depths to which the dredge has yet penetrated. It will be convenient to give here a brief general account of the struc- ture of the animals composing this order, and an explanation of the terms used in their description. Most of our marine species have a greater or less number of the segments at the posterior end of the body coalescent, but in the genus Cirolana they are distinct; the animals are, moreover, of large size and very abundant in some localities; ref- erence will therefore be constantly made to the figures of Cirolana concharum, on plates LX and X, in illustration of the parts of the animal and of the terms used. A few specimens of this animal will help mate- rially in gaining a knowledge of the structure of the group ; or, if speci- mens of Cirolana cannot be obtained, a common “sow-bug” (Oniscus or Porcellio) may be substituted. é The body appears to consist of fourteen segments, of which the first is the head; the next seven form the thorax, or pereion of Spence Bate, and the last six the pleon, sometimes called the abdomen. Returning to the head we find, looking from above, a pair of eyes—each consisting of a group of ocelli—and two pairs of antennary organs. Of these the upper pair, or antennule (pl. X, fig. 60), consist on each side of three comparatively large basal segments, which, together, are called the peduncle, or peduncular segments, and support a more slender and taper- ing flagellum or lash, composed of a considerable number of short seg- ments, decreasing in diameter toward the tip, and each, usually, bearing a fascicle of seta, which are called by Fritz Miiller olfactory seta, from their supposed function. The antennule are very small and rudimentary in “sow-bugs” and their allies. Below the antennul are the antennz properly so called (pl. X, fig. 61 a), which are also composed of a peduncle and flagellum. The five basal segments constitute the peduncle, and the following, usually much shorter and smaller segments, are flagellar. COT se ee MARINE ISOPODA OF NEW ENGLAND, ETC. 299 Underneath, the mouth is seen to be protected by a pair of organs called maxillipeds (pl. X, fig. 62 a), with which, for convenience of dissec- tion, we shall commence the description of the parts of the mouth. The five terminal segments of the maxillipeds in Cirolana (numbered 1 to 5 in the figure) constitute the palpus, but this number varies in the different genera. They are articulated to the external surface of the large basal segment (m), usually proportionally much larger than in Cirolana, as in Idotea phosphorea (pl. V, fig. 28b,m), or in the “sow-bug” where the palpus is greatly reduced. The basal segment of the maxilliped is, in gen- eral, produced internally beyond the origin of the palpus, and furnished with strongly plumose or pectinated sete at the tip. Frequently along its inner margin one or more short styliform organs are attached, as in Jera albifrons (pl. I, fig. 5), while along its basal margin is a more or less distinct suture, indicating the epimeral segment of this organ, which will be further explained. The basal segments of the opposite max- illipeds meet along the median line, where their margins are nearly straight, and to the base of the outer margin is attached a more or less triangular external lamella (pl. X, fig. 62 a,1). The name ‘ maxilliped” is frequently used for the basal segment only, which is often, as in the “sow-bugs,” much larger than the rest of the organ and serves to cover and protect the other organs of the mouth. When the maxillipeds are removed we find two pairs of maxille, the outer and inner; of these the outer, or second pair (pl. X, fig. 61), are in general of a delicate texture, and three-lobed at the tip, the two outer lobes being articulated to the basal piece, and all three lobes cili- ated on their inner margins. The inner, or first pair of maxille are of a less delicate texture than the outer, and are hardly of the ordinary form in Cirolana (pl. X, fig. 61 ce); reference may, therefore, be made to Synidotea nodulosa (pl. VI, fig. 35 ¢), where the two unequal lobes are shown, the inner comparatively small, and supported on a slender pe- duncle, curved inward, truncated at the tip, and bearing stout, curved, pectinated sets; the outer much more robust and larger, similar in general outline to the inner, but armed with stout, curved, denticulated spines at the tip. The mandibles (pl. X, fig. 61 d) are usually toothed at the apex, the teeth being supported on a dentigerous lamella, which may be double on one mandible, usually the left, and receive the lamella of the oppo- site mandible between the two; below this lamella is often a comb of pectinate sete, and, generally, a molar process, as in Janira alta (pl. III, fig. 12 b, m). In many genera a three-jointed palpus (pl. X, fig. 61 d, p) is articulated to the external surface of the mandible, and, usually, the terminal segment of the palpus is more or less semicircular, or curved, and bears on its inner margin a very regular comb of sete (pl. ILI, fig. 12 b), apparently of service in cleansing the organs of the mouth. This comb may be continued or repeated on the second segment, as in Ciro- lana (pl. X, fig. 61 d, p). In the “sow-bug” and many other genera the 300 REPORT OF COMMISSIONER OF FISH AND FISHERIES. mandibles are destitute of palpi. The oral opening between the mandi- bles is defended by an upper and lower lip, or labrum and labium, which are, however, median, and not paired organs, like the other parts of the mouth. The seven thoracic segments are of firm texture above, but softer underneath. The dorsal surface is in general more or less rounded, and in Cirolana is continued well down at the sides, where, except in the first segment, it is crossed by a suture cutting off a quadrate, or somewhat triangular piece, called an epimeron, or, in the plural, the epimera. The epimera are well shown in the side view of Cirolana concharum (pl. IX, fig. 58). They belong to the legs, and form a portion of the large prox- imal segment called the coxa. Usually, however, the legs are figured as in pl. X, fig. 62 b, without this segment, which adheres strongly to the body; often, as in the first segment of Cirolana, the suture sep- arating it disappears. The remaining six segments of the legs are more slender, and are called respectively, beginning with the segment follow- ing the coxa, the basis, ischium, merus, carpus, propodus, and dactylus, the last being usually slender and curved, often bearing a curved spine or claw at the tip, and, especially in the first pair, capable of flexion on the propodus, so as to form a prehensile hand. In the Tanaide, as in many of the higher Crustacea, the propodus may be prolonged into a digital process, against which the dactylus closes, forming a chela (pl. XIII, fig. 85), or chelate hand, as in the lobster. In the dgid@ and the OCymothoide a greater or less number of the dactyli are strongly curved or hooked, for the purpose of retaining firm hold of the host, on which these parasitic species live. Legs thus constructed are called ancoral, as in Livoneca ovalis (pl. XI, fig. 67 d and e). Of the seven pairs of legs attached to the thorax or pereion, the first three have in general a resemblance to each other, and are often more or less prehensile, while, as in Chiridotea (pl. IV, figs. 16 and 20), the last four are more strictly locomotive organs; but to. this condition of things there are many exceptions, especially in the development of the first pair of legs, which are quite variable throughout the order, be- ing not even pediform in the males of the Gnathiide, but two-jointed, in our species, and lamelliform (pl. XI, fig. 76 d). Except in this family, however, no confusion arises from speaking of the thoracic appendages as the first to the seventh pair of legs, or thoracic legs, and in general these terms will be used except where it may be necessary to use the technical terms, gnathopods or gnathopoda and pereiopods or pereiopoda, for these organs, as proposed by Spence Bate, according to whose system the first and second pairs are called the first and second pairs of enathopoda* or gnathopods, and the remaining five pairs the first to the fifth pair of pereiopoda or pereiopods. When necessary these terms will be added as explanatory, having the merit of scientific accuracy as well as applicability to other groups of Crustacea, where a * See also Edwards, Ann. Sci. nat., IIS, tome xvi, p. 221-291. MARINE ISOPODA OF NEW ENGLAND, ETC. 301 marked distinction of structure and function frequently occurs between the organs homologous with the second and third pairs of legs in the Isopoda. In the adult females of this order there is commonly formed, on more or less of the under surface of the thorax, an incubatory pouch for the reception and development of the eggs. The outer surface of the pouch is usually formed by four pairs of lamellae attached just within the origins of the second, third, and fourth, together with the first or fifth _ pairs of legs, and in the females of many genera, Sphwroma and Asellus for instance, these lamellae may be observed in a rudimentary condition on the under surface of the thorax when not actually in use carrying eggs or young. In Asellus, and in some other genera, they are found upon the first to the fourth segments, instead of the second to the fifth. In Anthwra the incubatory pouch extends over only three seg- ments, the third, fourth, and fifth; and in Astacilla it is confined to a single segment, being composed of a single pair of elongated plates attached to the fourth segment. ‘tn TYanais a further remarkable va- riation occurs, and the eggs and young are carried in sacs attached to the under surface of the fifth thoracic segment, while in the closely allied genus Leptochelia the form of the ineubatory pouchis normal. Jn the Gnathiide and Anthuride, according to Spence Bate and Dohrn, the incubatory pouch is formed by the splitting of the integument of the inferior surface of the thoracic segments in the females, and for the dis- charge of the young the outer lamella thus formed further divides into scales, one pair for each segment of the pouch. In Jera, Hpelys, and. probably other genera, a similar mode of development seems to occur. The six segments of the pleon are smaller than those of the thorax, often much smaller, and frequently more or less united, sometimes consolidated into a single piece with scarcely any trace of division above, but the number of pairs of appendages is generally six, show- ing the composite nature of the apparently simple organ. Of these six pairs of appendages or pleopods, the first five are more or less con- cealed beneath the pleon, and consist on each side of a basal segment bearing two lamellz (pl. IV, fig. 19 c), of which the outer is the anterior when they overlap. These lamellie, at least the anterior pairs, are usually ciliated along more or less of their distal margins with long slender plumose setze. In the males of most of the genera, the inner jamella of the second pair bears, articulated near the base of its inner margin, a slender stylet (pl. IV, fig.19 b,s). This stylet seems to afford, in many cases, specific and even generic characters. The last segment, sometimes called the telson, has its pair of append- ages specially modified, and called the uropods (pl. X, fig. 63). They consist in general like the pleopods of a basal segment bearing two lamellz, or rami, not being always lamelliform, and in the Tanaide they are more or less segmented (pl. XIII, fig. 86). One of these rami may disappear, as in Sphwroma and in some of the Idoteide (pl. V, fig. 25 ¢), where a further modification takes place, and the uropods are so articu- 302 REPORT OF COMMISSIONER OF FISH AND FISHERIES. lated to the inferior surface of the pleon as to fold together like a pair of cupboard doors, forming an operculum for the protection of the more delicate pleopods. Except in the Tanaidea, respiration is carried on by means of the pleopods. In the Asellide, Idoteide, and some other families two or more of the segments of the pleon are united, so that, seen from above, the pleon, like the head, may appear to consist of a single segment, as in Jera albi- Jrons (pl. I, fig. 4), but the number of pairs of its appendages, usually Six, remains as evidence of this consolidation. In like manner the - head is to be regarded as composed of several segments united, and the number of such segments is indicated by the number of pairs of appen- dages. In the Tanaide and many of the higher Crustacea, the eyes, more or less distinctly stalked or articulated with the head, are seen to be of the nature of a pair of appendages, which may be regarded as be- longing to the first cephalic segment. The antennule and antenns represent, respectively, the second and third cephalic segments, and, in like manner, the mandibles and two pairs of maxillze represent the fourth, fifth, and sixth segments of the head. A seventh segment is indicated by the maxillipeds. This segment is regarded by Huxley as properly thoracic* instead of cephalic, but, for purposes of description, the segment and its appendages will be regarded as belonging to the head, and the next segment considered the first thoracic. This segment, like the following thoracic segments, is usually free, and has the dorsal region well developed, but in the adult Gnathia it is united with the head, and still more closely so in the Tanaide. The seventh thoracic segment is the last to develop, and in young Isopoda, taken from the incubatory pouch, only six pairs of legs are commonly found. In Gnathia this condition prevails through life, and in the adults the first pair of legs are also modified, especially in the males, so as to quite lose their pediform character, leaving apparently only five pairs of legs. Further modifications of structure will be described in the fam- ilies and genera in which they occur. The nomenclature adopted, as explained above, corresponds nearly with that proposed by Mr. C. Spence Bate in his Report on British Edriophthalma, and used by the authors of the British Sessile-eyed Crustacea. The length of an Isopod, in the present article, is given as the length of the body, exclusive of appendages, and is measured from the front of the head to the tip of the pleon. When, as in Janira, the head is produced medially into a “rostrum” (see pl. IT, figs. 9 and 10), the meas- urement is taken from the tip of the rostrum, which is a part of the head, and not properly an “appendage.” Among the Hdriophthalma or sessile-eyed Crustacea, the Isopoda may in general be characterized as follows: Body depressed rather than compressed; respiration carried on by means of the pleopods, of which the last pair only are modified into uropods. * TWnvlaw Anat Tnvw Am ead n WER MARINE ISOPODA OF NEW ENGLAND, ETC. 303 The body is said to be depressed, or flattened from above, in distinetion from the form usually seen in the Amphipoda, where it is in general flat- tened from side to side. An important exception to the ordinary mode of respiration occurs in the Tanaide, as has already been mentioned. In this family respiration takes place in two lateral cavities, situated beneath the integument of a large cephalothoracic shield, covering the head and first thoracic segment. In general, as the name of the order indicates, the legs are similar in structure and function throughout, as in the “ sow-bug,” but may differ considerably, as in the Arcturide, the Munnopside, and the Tanaide. The arrangement of the families in the present paper can only be re- garded as tentative, and no higher grouping will be attempted further than to indicate briefly the relationships of a few of the families to each other. The Oniscide may, on account of their aérial respiration, be regarded as Standing quite distinct from the remaining families, and should, per- haps, be further divided as proposed by Kinahan. As they do not, how- ever. come within the proper scope of this article, I have not attempted to subdivide the family. The Bopyride have been placed near the Onis- cide in deference to the opinions of Dr. Fritz Miiller. Having made no study of this family myself I do not express any opinion as to the pro- priety of separating it so widely from the Cymothoide, with which it has usually been associated. The Asellide and Munnopside are closely allied to each other. The Jdoteide and Arcturide form a group distinguished especially by their operculiform uropods. The above families correspond nearly with the ‘ marcheurs” or walking Isopoda of Edwards, and more nearly with the “‘ gehende Asseln” of Miiller. They usually have the antennulz much less developed than the antenne, and the uropods ter- minal or inferior, that is, attached to the end of the last segment, or in the last two families to its inferior surface. The Spheromide and Limnoriide are closely allied, and perhaps ought hardly to be kept separate as families. The Cirolanidw, Afgide, and Cymothoide form another group embracing a wide diversity of forms, from the active predatory Cirolana to the sedentary and distorted Livo- neca, and yet apparently connected by easy gradations. The remaining families are generally regarded as aberrant, and form the “ Isopoda aberrantia” of Bate and Westwood. They do not present any very evi- dent relationships with the preceding. Of these the Anthuride have usually been associated with the Idoteide or the Arcturide, or with both. Except an elongated form, however, they do not appear to have much in common with either of these families. According to Dohrn’s observations they are related to the Gnathiide in the structure of the incubatory pouch. The Gnathiide have the head united with the first thoracic segment, as in the Tanaide, but this last family is widely sep- arated from the others, and doubtless ought to be regarded as forming a distinct suborder, according to the views of Dr. Fritz Miiller. 304 REPORT OF COMMISSIONER OF FISH AND FISHERIES. The arrangement of the families adopted, and to a certain extent their affinities, are indicated in the subjoined table, in which, however, as throughout the article, special reference is had to the representatives of the order in New England waters, extralimital species, genera, and even higher groups, Apseudes and the Serolids, for example, being disre- garded. The arrangement will be seen to considerably resemble that of Dr. Fritz Miiller. I have placed the Tanaide at the other end of the order, partly, however, from the necessity of a lineal arrangement. SYNOPTICAL TABLE OF FAMILIES. I. Respiration pleonal; legs not furnished with a chelate hand. 1, Legs in seven pairs. @ Antennule small or rudimentary; antennze longer, often much elongated. t Uropods terminal, sometimes rudimentary, rami mostly styliform. Legs ambulatory; antennule rudimentary; respiration aerial. I. ONISCIDA, p. 305 Legs prehensile; sexes very unlike; adult forms degenerate; para- BIMIG 0222 cosine ee ssise Soseee Sclnds ccscts taeese seuees II. Bopyrip&, p. 311 Legs ambulatory or prehensile ; segments of pleon united ; antennz with a multiarticulate flagellum. =.....-2.-. «sce. seas III. ASELLIDA, p. 312 Last three pairs of legs natatory; segments of pleon united; antenne with a multiarticulate flagellum..-.-...-...-.------ IV. MUNNOPSID&, p. 328 tt Uropods inferior, operculiform. Legs prehensile or ambulatory, not ciliated...-...----. V. IDOTEIDA, p. 335 First four pairs of legs ciliated; last three pairs ambulatory. VI. ARCTURIDA, p. 361 b Antennule and antenne subequal; body not elongated. t Uropods lateral, with one ramus obsolete or subrudimentary. Antennulz and antenne well developed; pleon of two segments; uropods with one movable ramus ......--....--.------ VIL. SPHZROMIDZ, p. 367 Antennule and antenne short; pleon of six segments; outer ramus of uro- mods:smalll 5 jj. y5-bacs Geen Vet toa sesseee ees VIII. LimnoruD#, p. 371 tt Uropods lateral, distinctly biramous; rami mostly lamelliform. Mouth carnassial; legs not ancoral; antennulxw exposed in front; pleopods Cla adligas%s = tarscs Bees sence se ss sneee aee ecm sm IX. CIROLANIDA, p. 376 Mouth suctorial; first three pairs of legs ancoral; antennulze exposed in frontcstth, essed. de babesdeuiuae Ceaskes See eam se X. AGIDA, p. 382 Mouth suctorial ; legs all ancoral; antennulz concealed at base by the pro- jecting front; pleopods naked..............-.. XI. CYMOTHOID#, p. 390 ce Antennulx and antenne subequal, or antennulze much the largest in the males; body cylindrical, elongated. t Uropods lateral and superior. Legs ambulatory or prehensile..-.....---.-.---.- XII. ANTHURIDA, p. 396 2. Legs in the adult in six, apparently only five, pairs. Five pairs of legs ambulatory ; antennule and antennez subequal. XIII. GnaTuup#, p. 408 II. Respiration cephalothoracic; first pair of legs terminated by a chelate hand. Legs ambulatory and prehensile; head united with the first thoracic seg- ment; antennular flagellum single.......-.....-. XIV. TANAIDA, p. 413 . MARINE ISOPODA OF NEW ENGLAND, ETC. 305 I—ONISCIDA. Antennulz rudimentary ; legs ambulatory; pleon of six distinct seg- ments, of which the last is small; mandibles without palpi; uropods terminal.* This large and important group of Isopoda being terrestrial in habit, only afew species are mentioned in this paper. They inhabit moist situa- tions, and are commonly known as “‘sow-bugs,” “pill-bugs,” “ wood-lice,” &c. Several species may often be found under an old board or pile of rubbish. The genus Ligia Fabr. inhabits sea-shores, above tide-level, and a few other genera are found under heaps of seaweed, or burrowing in the sand along the shore. Three such species, belonging to as many genera, are here described and figured, but are less fully treated of than the marine species that follow in the other families. Other species, especially of the genus Porcellio, may be found in similar situations. The family may be at once recognized by the apparent possession of only a single pair of antenne. These are the antenne properly so ealled, the antennulx being minute and rudimentary. This is generally regarded as a character indicating a high degree of development, and causes them to somewhat resemble externally some of the shorter myrio- poda, which, like other insects, have but a single pair of antennary organs. The maxillipeds are large and operculiform in this family, with short and few-jointed palpi. The mandibles are destitute of palpi. The legs are rather weak and fitted only for walking, and usually more or less concealed by the projecting epimeral regions of the thoracic seg- ments. Thepleon, in our species, has its segments distinct and decreas- ing rapidly in size to the last, which bears the more or less exserted uro- pods. These organs may not, however, project beyond the general outline of the pleon, as they scarcely doin Actoniscus, while in Armadillo they assist in forming the very regular outline of that part of the body, which closes against the head when those animals, as is their habit, roll themselves into a ball on being alarmed. This family is placed by Bate and Westwood in a separate “division,” the “Airo-spirantia,” on account of their aérial respiration. The air, however, requires to be saturated with moisture, and in some of the genera the respiration is, in part at least, aquatic. On this subject the reader is referred to the publications of Duvernoy and Lereboullet and of Nicholas Wagner. Philoscia Latreille. Philoscia Latreille, Hist. nat. des Crust. et des Ins., tome vii, p. 43, ‘* 1804.” Head rounded in front, not lobed; antennz with its segments cylin- drical, flagellum three-jointed ; pleon suddenly narrower than the thorax; uropods exserted, basal segment broad, rami elongate. *The above diagnosis would not include the genera Tylus Latreille nor Helleria Ebner, which perhaps ought not to be regarded as belonging to this family, although closely allied to it. 3 °0 F 306 REPORT OF COMMISSIONER OF FISH AND FISHERIES. This genus may be recognized among our Oniscide by the rounded head without lobes, and the conspicuously narrowed pleon. Only a single species is as yet known from New England. Philoscia vittata Say. Philoscia vittata Say, Jour. Acad. Nat. Sci., vol. i, p. 429, 1818. Dekay, Zool. New York, Crust., p. 50, 1844. White, List Crust. Brit. Mus., p. 99, 1847. Harger, This Report, part i, p. 569 (275), 1874; Proc. U. 8. Nat. Mus., 1879, vol. ii, p. 157, 1879. PLATE I, Fie. 1. This species may be recognized, among our terrestrial Isopoda, by the absence of the usual antero-lateral processes on the head, in front of the eyes, and by the sudden contraction of the body at the base of the abdomen or pleon. Body oval, smooth; about twice as long as broad; head nearly twice as broad as long; eyes large, occupying the antero-lateral regions of the head. The antennule are minute and concealed from above. An- tennze minutely hirsute, especially on the last three, or flagellar, seg- ments, inserted below the inner margin of the eyes; first segment short; second about twice as long as the first; third equal in length to the see- ond, clavate; fourth longer cylindrical; fifth longest, slender, cylindrical, straight; flagellum slender, three-jointed, longer than the fifth or last peduncular segment; first flagellar segment about one-half longer than the second; third longer than the second, tapering, tipped with a short transparent filament. The first thoracic segment is longer than the following ones, which are of about equallength. The anterior angles of the first thoracic segment are somewhat produced at the sides around the head; the posterior angles are broadly rounded. The second and third segments have their pos- terior angles less broadly rounded, but not at all produced backward. In the fourth segment this angle is scarcely produced, but in the fifth, and still more in the sixth and seventh, it becomes produced and acute. The legs increase in size and length from the first to the seventh pair, and are well armed with spines, especially upon the inferior surfaces of the meral, carpal, and propodal segments. The spines on the latter seg- ment are, however, much smaller than those on the merus and carpus. The pleon is at the base about two-thirds as wide as the seventh thoracic segment. In the first two segments of the pleon the coxe, or lateral lamel- le, are short, small, and nearly concealed by the seventh thoracic segment, but in the third, fourth, and fifth segments they are evident and acute but not large. The sixth segment is acute but not prolonged behind, and ex- tends beyond the end of the basal segment of the uropod, which is broad and bears the two rami nearly on the same transverse line. The outer ra- mus, seen from above, is narrowly and obliquely lanceolate in outline, tapering to the tip, and surpasses by less than half its length the more slender, styliform inner ramus. The uropods, the legs and antenna, and thea caomante af tha nlann alanoe their marain. 9rea verv minntelv hirentea. a? fi OF ere ow Sete belli oe MARINE ISOPODA OF NEW ENGLAND, ETC. 307. The color of these animals is dull and somewhat variable, usually brownish or fuscous, with lighter margins and two broad dorsal vitte. Length 8™™, breadth 4™™. This species has been found under rubbish and stones from Great Egg Harbor,! N.J.,to Barnstable,! Mass. All the specimens that I have seen have been from the coast, although Say states that it is “very commen - under stones, wood, &c., in moist situations.” Specimens examined. %¢ 8 A - When col- ived fr 8 FI Dry. 2 Locality. Habitat. Neate Received from— | 5-3 | ayy, : ce z Be 1222 | Somers and Beesley’s Points, | Shore.......-...] —— —,1871| A. E. Verrill and Ale. N.J. Smith......-. 25 1911 | Stony Creek, Conn ...-....-. SC PEO SER OEE [Hane ME Se Cees ACES Vierriteess.|ist2s5 Ale. 2146 | Vineyard Sound, Mass...... SEA) a ences — —,1871| U.S. Fish Com....| 8 | Alc. 1910 | Barnstable, Mass --...--.-..-. Seni eeeiginc aoe se Aug. 30, 1875 |..-.-. CO seareee ean 3 | Alc. Scyphacella Smith. Seyphacella, Smith, This Report, part i, p. 567 (273), 1874. Antenna composed of eight distinct segments, with a geniculation at ‘the articulation of the fourth with the fifth segment; terminal portion, or flagellum, composed of three closely articulated segments besides a minute apical one; mandibles slender; exposed portion of the maxilli- peds formed of only two segments. The genus Scyphacella was founded by Professor S. I. Smith, in part I of this Report, for the reception of the following species, the only one yet known. In regard to the relations of the present genus with Scyphax Dana* Professor Smith says: “This genus differs from Scyphax most notably in the form of the maxillipeds, which in Scyphax have the ter- minal segment broad and serrately lobed, while in our genus it is elon- gated, tapering, and has entire margins. In Scyphaz, also, the posterior pair of thoracic legs are much smaller than the others, and weak; the last segment of the abdomen is truncated at the apex, and the articula- tions between the segments of the terminal portion of the antenne, are much more complete than in our species. The general form and appear- ance of the genera are the same, and the known species agree remark- ably in habits, the Scyphax, according to Dana, occurring on the beach of Parua Harbor, New Zealand, and found in the sand by turning it over for the depth of a few inches.” Scyphacella arenicola Smith. Scyphacella arenicola Smith, This Report, part i, p. 568 (274), 1874. Verrill, This Report, part i, p. 337 (43), 1874. Harger, Proc. U.S. Nat. Mus., 1879, vol. ii, p. 157, 1879. PuLatTe I, Fie. 2. The small size, nearly white color, and peculiarly roughened surface of this Isopod will in general serve for its recognition, and the presence *U. S. Exploring Expedition, Crustacea, p. 733, pl. 48, fig. 5. 308 REPORT OF COMMISSIONER OF FISH AND FISHERIES. of eyes will further distinguish it from Platyarthrus, which is often found inhabiting ants’ nests, but would hardly be likely to occur in the sand of the beach. Body elliptical, pleon not abruptly narrower than the thorax, dorsal surface roughened throughout with small depressed tubercles each giving rise to a minute spinule. Head transverse, not lobed; eyes prominent, round; antennz longer than the breadth of the body; with the first and second segments short; third, fourth, and fifth successively longer and of less diameter; flagellum shorter than the fifth segment, composed of three closely articulated, successively smaller segments, and a very short somewhat spiniform but obtuse terminal one; all the segments, except the minute terminal one, beset with small scattered spinules. First thoracic segment scarcely embracing the head at the sides; sec- ond, third, and fourth segments each about as long as the first, but in- creasing in breadth; fifth, sixth, and seventh diminishing in length and the last two also in breadth. Posterior lateral angles of the first three segments not at all produced, hardly perceptibly produced in the fourth segment; fifth, sixth, and seventh with the angles increasingly produced but not acute. Legs increasing somewhat in size posteriorly, armed, especially on the inferior surface of the meral, carpal, and propodal seg- ments, with short stout spines. , Segments of the pleon with the coxe but little developed. Ter- minal segment slightly rounded at the end, not attaining the end of the basal segment of the uropods, which are robust, with the basal segment spinulose, tapering to the base of the short, stout, outer ramus, and bearing the more slender inner ramus much nearer its base. The inner ramus is actually longer than the outer, but being inserted much lower down does not attain the tip of the outer ramus; both are tipped with sete. ** Color, in life, nearly white, with chalky white spots, and scattered, blackish dots arranged irregularly. Eyes black.” Length 3.4™™, This species was “found at Somers and Beesley’s Points, on Great Egg Harbor!, New Jersey, in April, 1871, burrowing in the sand of the beaches, just above ordinary high-water mark, in company with sey- eral species of Staphylinide,” and has also since been found by Pro- fessor Smith at Nobska Beach, Vineyard Sound !, Mass., in 1871, and by Mr. V. N. Edwards, on the beach at Nantucket Island!, December 6, 1877. It will doubtless be found at other points along the coast and toward the south. Specimens examined. Gy on ’ A 5 4 . When col- He D ; 4 Locality. Habitat. nected: Received from— a3 ALL 5 52. A ae Great Egg Harbor, N. J.-.--. Sandy beach .-.-.} Apr. —, 1871] S.I. Smith ........./-.---- Ale. 2136 | Nobska Beach, Mass ....-.--. o0a=G0 secne eee Aug. 18, 1871 ]|...--. d0...2 See eee 2 | Alc. Wantuckett. cjo-2-met esa inne 32320022 en sanceeee Dec. 6,1877| V.N. Edwards ..... 1 |-Alc, IC os ?- MARINE ISOPODA OF NEW ENGLAND, ETC. 309 Actoniscus Harger. Actoniscus Harger, Am. Jour. Sci., III, vol. xv, p. 373, 1878. Eyes small; antenne geniculate at the third and fifth segments; fla- gellum four-jointed ; terminal segments of maxillipeds lamelliform, lobed; legs all alike; basal segment of uropods dilated and simulating the coxee of the preceding segments of the pleon; rami both styliform. This genus resembles Actewcia Dana* MSS., considered as the young of Scyphax ornatus, and found with it on the beach at New Zealand. Pro- fessor Kinahan,{ on the other hand, regarded the genus as indicating a distinct family. The present genus differs from the description and figures of Professor Dana as follows: The flagellum of the antennz con- sists of only four distinct segments instead of about six; the terminal segment of the maxillipeds is less distinctly lobed ; the inner ramus of the uropods surpasses the outer, instead of falling far short of it; the outer ramus is styliform instead of being enlarged and subequal to the produced and enlarged outer angle of the basal segment. Actoniscus ellipticus Harger. Actoniscus ellipticus Harger, Am. Jour. Sci., III, vol. xv, p. 373, 1878; Proc. U.S. Nat. Mus., 1879, vol. ii, p. 157, 1879. PLATE I, Fig. 3. This species may be at once recognized by the pleon, which appears to have four pairs of coxz produced at the sides instead of three, as in Oniscus and other genera of this family. The last pair are, however, the basal segments of the caudal stylets, which are of peculiar form in this genus. The body is ovalin outline. The head appears triangular as seen from above, and.is angularly produced in a median lobe, but the lateral lobes are also large and divergent, and broadly rounded. The eyes are small, oval, black, and prominent. They are situated at the sides of the me- dian triangular part of the head, and at the base of the lateral lobes. The antennule are minute and rudimentary. The antenne have the basal segment short; the second enlarged distally, especially on the inner side; the third forming an angle with the second, and clavate; the fourth flattened-cylindrical, longer than the third; fifth longest, slender, bent at base and forming an angle with the fourth; flagellum shorter than the last peduncular segment, tipped with sete and com- posed of four segments, of which the second and third are equal and longer than the first, while the last is the shortest, and presents indica- tions of another minute rudimentary terminal segment. The maxil- lipeds have the basal segment nearly twice as long as broad; the terminal segment elongate triangular, ciliated and somewhat lobed near the tip. *U. 8. Expl. Exped. Crust., part ii, p. 736, pl. 48, fig. 6 a-h. t Natural History Review, vol. iv, Proc. Soc., p. 274, 1857. 310 REPORT OF COMMISSIONER OF FISH AND FISHERIES. The first thoracic segment is excavated in front for the head, admitting it about to the eyes. The next five segments are each a little longer than the first, but the last thoracic segment is the shortest. The first segment is dilated at the sides to about twice its length on the median line. The second, and in an increasing degree the succeeding segments are produced backward at the sides. The legs are rather small and weak and of nearly equal size throughout. The first two segments of the pleon have their lateral processes, or cox, obsolete as usual in the family, but the third, fourth, and fifth segments are produced laterally into broad plates, which are close to- gether, and, at their extremities, continue the regular oval outline of the body with scarcely a perceptible break between the thorax and the pleon. This outline is further continued by the expanded basal seg- ments of the uropods, which are even larger than the adjacent cox of the fifth segment. At the extremity of the pleon both pairs of rami are visible, the inner springing from near the base of the basal segments below, the outer from a notch near the middle of the inner margin of the basal segment. The rami are tipped with sets, and the inner just surpass the outer, which, in turn, surpass the produced portion of the basal segments. Length 4™™, breadth 2™™. Color in life slaty gray. This species was collected by Professor Verrill, at Savin Rock, near New Haven!, and also at Stony Creek!, Long Island Sound, in company with Philoscia vittata Say. Specimens examined. | Pa | ~ e =] 3 Locality. Habitat. When col- | Received from— | 3.8 me i Be A A eee 2137 | Savin Rock, Conn...] Shore...----..----- Lakes ele Vices, eh TAs | EAD: Wom ll eee ee 2 | Alc. 2138 | Stony Creek, Conn..|-.- JINS# 65555, 555uGsepen0 | osc eS ER dO sexes amr 1 | Ale. The genus Ligia Fabricius* is recorded by Gouldt+ from the timbers of a wharf, sages, in Boston, and by Dr. Leidy,{ with some doubt, from Point Judith, R. L., and the characteristics of the genus are therefore here briefly inserted, as follows: Antenne with a inulaneicniate flagellum ; basal segment of uropods exserted bearing two elongated cylindrical Lae They are found usually in rocky places and under stones just above high-water mark. They are common on our southern coast, and are probably, at least occasionally, transported by accident within our lim- its. JI have seen no specimens from nearer than Fort Macon, N. C. * Suppl. Ent. Syst., p. 296, 1798. t Invert. Mass., p. 337, 1841. t Jour. Acad. Nat. Sci., II, vol. iii, p. 150, 1855. a, vee a os eRe MARINE ISOPODA OF NEW ENGLAND, ETC. 311 II.—BOPYRID i. This family has not been studied, and only a list of the species, fur- nished by Professor 8. I. Smith, is included. They are parasitic on Crus- tacea, and at maturity, the females especially, are generally much dis- torted and degenerate, often losing a great proportion of their appendages. ~The males are much smaller than the females, and of a more normal form, and they and the young forms must therefore be relied upon to indicate the affinities of this group to the rest of the order. According to Dr. Fritz Miiller these forms indicate a relationship to the Onscide, and especially to the genus Ligia, and in deference to his authority I have inserted them at this place. Beton distortus Leidy. Cepon distortus Leidy, Jour. Acad. Nat. Sci., II, vol. iii, p. 150, pl. xi, figs. 26-32, 1855. Harger, This Report, part i, p. 573 (279), 1874; Proc. U. S. Nat. Mus., 1879, vol. ii, p. 157, 1879. Leidya distorta Cornalia and Panceri, Mem. R. Accad. Sci. Torino, II, tom. xix, p- 114, 1861. “From the branchial cavity of Gelasimus pugilator, Atlantic City, New Jersey.” (Leidy.) Gyge Hippolytes Bate and Westwood (Kroyer). Bopyrus Hippolytes Kroyer, Grénlands Amfipoder, p. 306 (78), pl. iv, fig. 22, 1838; Monog. Fremst. Slegten Hippolyte’s nordiske Arter, p. 262, 1842; Voy. en Seand., Crust., pl. xxviii, fig. 2, 1849. Edwards, Hist. nat. des Crust., iii, p. 283, 1840. Stimpson, Proc. Acad. Nat. Sci. Philadelphia, 1863, p. 140. Gyge Hippolytes Bate and Westwood, Brit. Sess. Crust., vol. ii, p. 230,1868. Buchholz, Zweite deutsche Nordpolfahrt, p. 286, 1874. Metzger, Nordseefahrt der Pomm., p. 286, 1875. Miers, Ann. Mag. Nat. Hist., IV, vol. xx, p. 64, (14), 1877. Smith in Harger, Proc. U. 8. Nat. Mus., 1879, vol. ii, p. 157, 1879. Massachusetts Bay !, off Salem, on Hippolyte spinus, 30 fathoms, sand and mud, August 4, 1877; on H. Fabricii, 22 fathoms, gravel, August 4, 1877; on H. securifrons, 90 fathoms, soft mud, August 14, 1877, Casco Bay !, on H. polaris and H. pusiola, 1873. Bay of Fundy !, on H. spinus and H. pusiola, 1868, 1872. Off Halifax, Nova Scotia, 43 fathoms, Sep- tember 27, 1877. Gulf of Maine !, 40 miles east of Cape Ann, Massa- chusetts, on H. securifrons, 160 fathoms, soft mud, August 19, 1877; also neur Cashe’s Ledge, on H. spina, 27 and 40 fathoms, rocks and gravel. East side of Smith’s Strait, north latitude 78° 30’ (Stimpson). ‘ Dis- covery Bay,” north latitude 81° 44’, Greenland (Miers). British Islands (Bate & Westwood). Scandinavian coasts (Kroyer et al.). Spitzber- gen (Kroyer). 312 REPORT OF COMMISSIONER OF FISH AND FISHERIES. Phryxus abdominalis Liljeborg (Kréyer). Bopyrus abdominalis Kroyer, Nat. Tidsskr., vol. ii, pp. 102, 289, pls. i, ii, 1840; Monog. Fremst. Slegten Hippolyte’s nordiske Arter, p. 263, 1842; Voy. en Scand., Crust., pl. xxix, fig. 1, 1849. Phryxus Hippolytes Rathke, Fauna Norwegens, p. 40, pl. ii, figs. 1-10, 1843. Phryxus abdominalis Liljeborg, Gifvers. Kongl. Vet.-Akad. Férh., ix, p. 11, 1852. Steenstrup and Liitken, Vidensk. Meddelelser, 1861, p. 275 (9). Bate and Westwood, Brit. Sessile-eyed Crust., vol. ii, p. 234, 1868. Norman, Rep. Brit. Assoc., 1868, p. 288, 1869; Proc. Royal Soc., London, vol. xxv, p. 209, 1876. Buchholz, Zweite deutsche Nordpolfahrt, p. 287, 1874. Metzger, Nordseefahrt der Pomm., p. 286, 1875. Miers, Ann. Mag. Nat. Hist., IV, vol. xx, p. 65 (15), 1877. Smith in Harger, Proc. U. §. Nat. Mus., 1879, vol. ii, p. 158, 1879. Massachusetts Bay!, off Salem, on Pandalus borealis, Hippolyte spinus, and H. securifrons, 48-90 fathoms, soft mud, August 13 and 14, 1877; also, on Pandalus Montagui, 35 fathoms, mud and clay nodules, Au- gust 10, 1877. Cashe’s Ledge !, Gulf of Maine, on Hippolyte pusiola, 27 and 39 fathoms, rocky, September 5, 1874. Halifax !, Nova Scotia, on Hippolyte pusiola, 18 fathoms, fine sand, September 4, 1877; also, on H. spinus. About 30 miles south of Halifax !, on Hippolyte securifrons, 100 fathoms, fine sand, September 6, 1877. Grinnell Land, in north latitude 79° 29’; and “ Discovery Bay,” north. latitude 81° 44’ (Miers). Greenland (Kroyer et al.). British Islands (Norman e¢ al.). Scandinavian coast! (Liljeborg et al.). Spitzbergen (Miers). _Dajus Mysidis Kroyer. Dajus Mysidis Kroyer, Voy. en Seand., Crust., pl. xxviii, fig. 1, 1849. Liitken, Crustacea of Greenland, p. 150, 1875. ?G. 0. Sars, Arch. Math. Nat., B. ii, p. 354 [254], 1877 (‘‘D. Mysidis?”), Smith in Harger, Proc. U. 8. Nat. Mus., 1879, vol. ii, p. 158, 1879. Bopyrus Mysidum Packard, Mem. Bost. Soc. Nat. Hist., vol. i, p. 295, pl. viii, fig. 5, 1867. ? Leptophryxus Mysidis Buchholz, Zweite Deutsche Nordpolfahrt, p. 288, pl. ii, fig. 2, 1874. Labrador (Packard). Greenland (Kréyer, Buchholz). ? Off west coast of Norway (G. O. Sars). Bopyrus, species. Bopyrus Leidy, Proc. Acad. Nat. Sci., 1879, pt. ii, p. 198, 1879. ? Smith, Trans. Conn. Acad., vol. v, p. 37, 1879. A species of Bopyrus is mentioned by Dr. Leidy as ‘‘a parasite of the shrimp, Palemonetes vulgaris,” occuring in the summer of 1879, at Atlantic City, N. J. IIJ.—ASELLID AS. Antenne elongated with a multiarticulate flagellum; legs ambulatory or prehensile, not strictly natatory; pleon consolidated into a scutiform segment, bearing terminal uropods, which may be nearly obsolete. This family is represented on our coast by four species belonging to MARINE ISOPODA OF NEW ENGLAND, ETC. 3138 three genera, and a species of another genus (Asellus communis Say) is common in the fresh-water ponds and streams of New England. The genus Jimnoria Leach has been regarded by modern writers as be- longing to this family, but will be found in the present article in the Limnoriide (p. 79). There remain then to be considered the genera Asellus Geoftroy,* Jera Leach, Janira Leach, and Munna Kroyer, which, as represented in our waters, may be further characterized as follows: The head is well developed, and in Munna is of large size; the body is usually depressed or but slightly arched, except that the pleon is vaulted in Munna. The eyes are present in our species though not through- out the family. The antennule beyond the basal segment are slender and are always much shorter than the antennz, which are elongated and composed of a five-jointed peduncle and a slender multiarticulate flagellum. The first three peduncular segments are short; the last two elongated. The parts of the mouth are protected below by a pair of maxillipeds with large external lamellz and five-jointed palpi. Within the maxillipeds are two pairs of maxille of the ordinary form; the outer or second pair delicate and three-lobed at the tip; the inner lobe being formed by the projecting basal segment, while the two outer lobes are articulated; all three lobes are provided with curved spiniform sete. _ The inner, or first, pair of maxilla present two narrow lobes; the outer lobe broader and more robust than the inner, and armed with robust curved spines, while the inner is tipped with much weaker setz. The mandibles (see fig. 12 b, pl. ITI) are provided with one or two acute den- tigerous lamelle (d) at the tip, usually a comb of setz and a strong molar process below (m), and a triarticulate palpus (p). This latter organ is, however, wanting in the genus Mancasellus Hargert from the Great Lakes and other fresh-water localities of North America. The seven segments of the thorax are distinct from the head and from each other, and differ but little in general appearance throughout. The legs are mostly slender and elongated, except that the first pair may be more robust and better fitted for prehension. In our marine species the dactylus, at least behind the first pair of legs, is short and armed with two small claws or ungues, while the propodus is capable of con- siderable flexion on the carpus. The segments of the pleon are united into a single piece, which is seuti- form above, flattened or but little arched, except in Munna, and bears, at or near the tip, the biramous uropods, which are, however, nearly obsolete’ in Munna. The pleon often shows more or less trace of its compound character in imperfect transverse sutures on the dorsal surface near the base, and below it is excavated for the pleopods, the posterior pairs of which are delicate and branchial in their nature, while the anterior pairs * «Fist. des Ins. t. ii” (Edw.). For information in regard to the common European form of this genus the reader should consult the admirable work of G-.O. Sars, Hist. nat. des Crust. d’eau douce de Norvége. tAm. Jour. Sci., III. vol. xi, p. 304,1876. See, also, op. cit., vol. vii, p. 601, 1874, and This Report, part ii, p. 659, pl. i. fig. 3, 1874. 314 REPORT OF COMMISSIONER OF FISH AND FISHERIES. are variously modified in the different genera and in the sexes, so that much confusion has been introduced into the family by mistaking sexual for generic modifications of these organs. The branchial pleopods are usually protected by a thickened anterior pair, which, especially in the females of our marine species, may be consolidated into a single opercu- lar plate, as will be further described. The incubatory pouch in the fe- males does not appear to extend farther back than the fourth thoracic segment, and it may be confined to the second, third, and fourth seg- ments. In the last-mentioned, as well as in many other characters, this fam- ily is closely related to the next, and perhaps the Munnopsidw may yet require to be united with it. Our species of the two families are at once distinguished by the last three pairs of legs, which are ambulatory in the Asellide and natatory in the Munnopside. Our Munnopside are, moreover, like the other known species of that family, destitute of eyes, while the marine Asellide have evident or conspicuous eyes, but the fresh-water genus Cecidotea Packard* is blind, as are also certain foreign species referred to the present family. The relations of the Asellide with families other than the Munnopside are less evident. They were associated by Professor Danaf with his Armadillide and Onis- cide to form his subtribe Oniscoidea, and, Iimnoria being excluded, the group appears to be a natural one. Asellus communis Say, confined to fresh waters, and the only known New England representative of the genus, was described and figured by the present author, in Professor 8S. I. Smith’s ‘Crustacea of the Fresh Waters of the United States,” published in part II of this report (page 657, plate I, figure 4). Our marine representatives of the family may be most easily recognized by the consolidated pleon, ambulatory or pre- hensile legs, none of them natatory, and the slender, elongate antenne. The genera may be distinguished by means of the following table: flattened above; uropods § short, subrudimentary .---.-----.--------7------2----- JERA, p. 314 Pleon BY CUNY ClO POU ls 2 oneal ne ee ei =e eee ee ee JANIRA, p. 319 vanilted + thes ane eee easter eee tetera eae ee a lee ele alee ee pele tele etter Munna, p. 325 Jeera Leach. Jera Leach, Ed. Encyc., vol. vii, p. “6434” (Am. ed., p. 273), ‘£1813-14.” Antennule short, few-jointed; antennze moderately elongated; man- dibles with palpi; first pair of legs similar to the following pairs; lateral margins of the thoracic segments projecting over the bases of the legs; . uropods short, rami subrudimentary; pleon protected below in the fe- males by a subcircular plate. The short uropods and projecting lateral margins of the thoracic seg- ments serve to distinguish this genus from its allies, and other charac- ters of generic importance could doubtless be drawn from the pleon and its appendages, as well as from other parts of the structure, but, as it *American Naturalist, vol. v, p. 751, figs. 132, 133, 1871. +Am. Jour. Sci., II, vol. xiv, p. 301, 1862. wid pal MARINE ISOPODA OF NEW ENGLAND, ETC. 315 is représented in our limits by a single species, I have not been able to separate the generic from the specific characters with confidence, and have therefore described the species without attempting it. Jera albifrons Leach. * Oniscus albifrons Montague MSS.” (Leach). Jera albifrons Leach, Ed. Encyce., vol. vii, p. ‘‘ 434” (Am, ed., p. 273), ‘*1813-14” ; Trans. Linn. Soc., vol. xi, p. 373, 1815. Samouelle, Ent. Comp., p. 110, 1819. Desmarest, Dict. Sci. nat., tome xxviii, p. 381, 1823; Consid. Crust., p. 316, 1825. Latreille, Régne Anim., tome iv, p. 141, 1829. Edwards, Annot. de Lamarck, tome vy, p. 267, 1838; Hist. nat. des Crust,, tome ili, p. 150, 1840; Régne Anim., Crust., p. 204, 1849. Moore, Charlesworth’s Mag. Nat. Hist., n.s., vol. ili, p. 294, 1839. Thompson, Ann. Mag. Nat. Hist., vol. xx, p. 245, 1847. White, List Crust. Brit. Mus., p. 97, 1847; Brit. Crust. Brit. Mus., p. 69, 1850; Pop. Hist. Brit. Crust., p. 231, 1857. Lilljeborg, Ofvers. Vet-Akad. Forh., Arg. Vili, p. 23; 1851; ibid., Arg. ix. p. 11, 1852. Gosse, Man. Mar. Zool., vol. i, p. 136, fig. 243, 1855. M. Sars, Christ. Vid. Selsk. Forh., 1858, p. 153, 1859. Bate, Rep. Brit. Assoc., 1860, p. 225, 1861. G. O. Sars, Reise ved Kyst. af Christ., p. (29), 1866; Christ. Vid. Selsk. Forh., 1871, p. 272, 1872. Norman, Rep. Brit. Assoc., 1866, p. 197, 1867; ibid, 1868, p. 288, 1869. Bate and Westwood, Brit. Sess. Crust., vol. ii, p. 317, figure, 1868. Metzger, J. B. Naturhist. Ges. Hannover, xx, p. 32, 1871; Nordseefahrt der Pomm., 1872~3, p. 285, 1875. Parfitt, Trans. Devon. Assoc., 1873, p. (18), “£1873.” Stebbing, Jour. Linn. Soc., Zool., vol. xii, p. 149, 1874; Ann. Mag. Nat. Hist., IV, vol. xvii, p. 79, pl. v, figs. 5-6, 1876; Trans. Devon. Assoc., 1879 p. (7), 1879. Meinert, Crust. Isop. Amph. Dec. Dan., p. 80, ‘£1877.” (Jaira.) Harger, Proc. U.S. Nat. Mus., 1879, vol. ii, p. 158, 1879. Jera Kréyeri Zaddach, Syn. Crust. Pruss. Prod., p. 11, ‘*1844” (J. Kréyeri Ed- wards 2). Jera baltica Fried. Miiller, Arch. Naturg., Jahrg. xiv, p. 63, pl. iv, fig. 29, 1848, Jera copiosa Stimpson, Mar. Iny. G. Manan, p. 40, pl. iii, fig. 29, 1853. Packard, Canad. Nat. and Geol., vol. viii, p. 419, 1863. Verrill, Am. Jour. Sci., III, vol. vii, p. 131, 1874; Proc. Amer. Assoc., 1873, p. 369, 1874; This Report, part i, p. 315 (21), 1874. Harger, This Report, part i, p. 571 (277), 1874. Jera nivalis Packard, Mem. Bost. Soc. Nat. Hist., vol. i, p. 296, 1867. (J. nivalis Kroyer ?.) Asellus Grénlandicus Packard, loc. cit. (not of Kroyer). Jera marina Mobius, Wirbellos. Thiere der Ostsee, p. 122, 1873; Ann. Mag. Nat. Hist., IV, vol. xii, p. 85, 1873. (J. marina Fabricius ?.) Jera maculata Parfitt, Trans, Devon. Assoc., 1873, p, 253” (18), 1873.” Stebbing, Trans. Devon. Assoc., 1879, p. (7) 1879, (albifrons). PriaTeE I, Fies. 4-8. This species is at once distinguished from the other marine Isopoda of our coast by the short uropods, arising from a notch in the end of the 316 REPORT OF COMMISSIONER OF FISH AND FISHERIES. subcircular pleon. From the terrestrial forms, which it somewhat re- sembles, and in company with which it may sometimes be found, the above-mentioned character, joined with the multiarticulate flagellum of the antenne, will serve to distinguish it. The body is oval and flattened, a little more than twice as long as broad. : The head is transverse, broadly excavated on each side over the bases of the antennule, sparingly ciliated on the lateral margins, with short scat- tered spine-like unequal cilia or sets, which occur in a similar manner along the entire borders of the animal behind the front margin of the head. The eyes are prominent and black, situated near the posterior margin of the lateral regions of the head. The antennule are five-jointed, and do not surpass the fourth segment of the antenne; the basal segment is large and separated from its fellow of the opposite side by about twice its diameter; the second segment is about as long as the first, but of much less than half its diameter; third segment shorter thah the second, fourth still shorter, fifth tapering, tipped with sete. The first three segments of the antennz are short; the fourth is robust, and about as long as the first three together; the fifth is longest, and is fol- lowed by a slender elongated flagellum. The maxillipeds (pl. I, fig. 5) have the external lamella (1) short and broad, nearly straight on the inner margin, broadly rounded at the end, and somewhat swollen on - the external side; the palpus (p) is five-jointed; the first three segments flattened, first short; second dilated internally and ciliated; third ciliate in the inner margin and narrowed to the base of the fourth segment, which is cylindrical; fifth short, conical. The terminal lobe of the max- illiped bears two rows of cilia near the apex, and on the inner side a row of short styliform organs. The outer maxille (pl. I, fig. 6 a) consist of a semioval portion, broad and ciliated at the tip, bearing above the middle two articulated lobes, armed with strong curved setz at the tip. The inner maxill (pl. I, fig. 6 b) are armed with short stout spines, which are strongly spinulose on their inner curved side; inner lobe about half the diameter of the outer. Mandibles with a very much projecting molar process, a comb of pectinated setze, and a dentigerous lamella, or two of them on the left side. The first three thoracic segments are of about equal length along the median line, and are together nearly equal in length to the last four, which are also subequal along the median line, but the fifth segment appears shorter than the others on account of its short lateral margin, . which has both its anterior and posterior angles strongly rounded. The epimeral region of the segments projects at the sides so as to cover the bases of the legs, and is squarish in the first three segments, rounded in the fourth, and still more so in the fifth, and obtusely angulated behind in the sixth and seventh. The legs are similar in form throughout, but increase in length to the last pair. They have the basis rather robust; the ischium shorter and flexed on the basis; the merus subtriangular, and tipped with spines; the carpus and propodus cylindrical, subequal ——— MARINE ISOPODA OF NEW ENGLAND, ETC. d17 in length, but the carpus of larger diameter than the propodus; the dactylus short, cylindrical, and provided with two terminal hooklets. There are a few scattered spinules and setz on the segments, especially the merus, carpus, and propodus. In the males the merus and carpus of the sixth and seventh pairs of legs are provided on their inferior mar- gins with close-set slender curved hairs, which extend nearly the whole length of the carpus and over the distal half of the merus. The pleon is proportionally broader and shorter in the male (pl. I, fig. 8) than in the female (pl. I, fig. 7). It is broadly rounded behind, continuing the outline of the body without break, and is notched at the tip for the insertion of the uropods, which scarcely project beyond the general outline of the body, and consist on each side of a short, stumpy, cylindrical basal segment, a little oblique at the end where it bears two almost rudimentary rami, the inner about twice as large as the outer, and both tipped with a few short sete. The lateral margin of the pleon, like that of the body generally, is beset with short, scattered, unequal set or spinules. Underneath, the pleon is excavated for the branchial pleopods, which are covered and protected below in the females (pl. I, fig. 7) by a large subcircular plate, sparsely minutely ciliated on the margin. In the male (pl. I, fig. 8) the under surface of the pleon presents on each side a small oval plate, with its. inner margin overlapped by a median elongated plate, divided by a cen- tral suture, which is open distally. This plate is broad at the base, then narrows toward the middle, after which it expands much more rapidly into an outwardly curved and pointed lobe on each side, ciliated at the tip. Between these two lobes the plate is terminated by two transverse, subquadrate and elongated lobes, which are broadest internally where they are separated along the median line. They are excavated on the anterior margin and less so on the posterior margin, sparsely ciliated behind, and conspicuously so with divergent cilia at the outer short, Straight margin. In the females the incubatory pouch appears to be confined to the second, third, and fourth segments. In size as well as coloration this species varies greatly, females being often found with eggs when less than half the size of the specimen fig- ured. They attain a length of 5™™ and a breadth of 2™™, but the males are at least one-third smaller and somewhat narrower than the females, the sides being more nearly parallel. In color there is also much varia- tion. A common color is a dark, slaty gray, with dots or small blotches. of yellowish, this color prevailing along the anterior margin of the head. Very frequently darker or lighter shades of green occur, and the incu- batory pouch of the females is often bright green. Some specimens are very light colored or nearly white, often with two or more transverse dark bands, with considerable contrast in color; others are reddish brown throughout. Iam unable to separate the American form, Jera copiosa Stimpson, from the common English and European species, although they have 318 REPORT OF COMMISSIONER OF FISH AND FISHERIES. hitherto been regarded as distinct. I have had no males from any European locality, but through the kindness of the Rev. A. M. Norman I have had an opportunity of comparing females from Oban, Scot- land, with our species, and have found no specific differences. The description and figures given by Rey. T. R. R. Stebbing in the Annals and Magazine of Natural History, IV, vol. xvii, p. 79, pl. v, figs. 5 and 6, show a substantial correspondence iu the males also, so that I have regarded the species as common to both coasts. Whether the Green- land species J. nivalis Kroyer, and the Southern species J. Kréyeri Hd- wards, are also identical with J. albifrons or not, I am unable to deter- mine, in the absence of specimens for comparison. M. Sars says that he has seen specimens of J. albifrons Leach from Trieste, but regards the Greenland species as distinct. Mé6bius regards the species as iden- tical from Greenland to the Mediterranean, and unites them under the name J. marina. Metzger, following Bate and Westwood, is more con- servative, using the name J. albifrons Leach. Bate and Westwood re- gard J. nivalis Kréyer and Oniscus marinus O. Fabricius as doubtfully identical with J. albifrons, and J. Kréyeri Edwards as distinct. J. Kroéyeri Zaddach = J. baltica Friedrich Miiller appears to be, without doubt, identical with this species, as it is separated by that author from J. albifrons Leach only by the position of the eyes, which were incor- rectly described by Dr. Leach as close together. I have, therefore, re- ferred these two names to J. albifrons as synonyms, as has been done previously by Lilljeborg and others. J. maculata Parfitt, a species based almost wholly on color markings, I have referred to J. albifrons, follow- ing Stebbing, who believes that he is “in accord with the author of the species” in so doing. This species is common, and in suitable localities abundant, on the whole coast of New England!, and extends as far north as Labrador! at least, where it was collected by Dr. Packard, who regarded it as identi- cal with J. nivalis Kréyer. It is found among rocks, algze, and rubbish along the shore, often nearly up to high-water mark, where it may be associated with some of the Oniscide, to which it has a certain resem- blance in form. It occurs “probably” all around the coast of England (Bate and Westwood). Ihave examined specimens from Oban!, Scot- land. It extends to Finmark, on the coast of Norway (M. Sars), and is common on all the coasts of the North Sea (Metzger). It is recorded by Mobius in the Baltic among stones and alge down to a depth of 184 fathoms. According to M. Sars this species extends to Trieste on the Adriatic, but without specimens I have not attempted to decide in re- gard to the synonymy of the Mediterranean species. SS a ee — MARINE ISOPODA OF NEW ENGLAND, ETC. 319 Specimens examined. a a mens 3) : | When col- : Dry. F Locality. e Bottom. leateds Received from— Alo 8 , im é No. | Sex. MER EN GW TEA VONy WOM, on) a2 seen min|cnnacclcce veer ceuna May 1,1871 Pl Pe Ale 1917 | Stony Creek, ie oy 8 4 OR OCR SO el ea 8) steeee Ale 1916 Noank Harbor, COT ac «Sol aaa PO et (RS —, 1874 25 eae ae Ale 1915 | Vineyard Sound, Be eee ee Cie Oe oI feel Fay’ AO aa 1 Q | Ale. Mass. 1 eG 6 ee ee L. w. | Under stones — —, 1871 80) 15.5052 Ale 1920 Provincetown, WE CCN SE ee EEO Seceoee — —,1872 bOtssecce | Ale Eee settee dae aie |btaes aoe Shore. o-- oi =<. 00 — —, 1879 }.... 00 | & 2 | Alc. Oe Ty Ane Pepe Peer eer ASAI spose sesene Aug. 13, 1879 |.... 00) co 2 | Alc. SO i WR ee ial Bat a he ee Aug. 13, 1879 |.... 15 Ale. 228 SE eee ee eae ao re OTAsS. wees ‘Aug. 23) 1879 |.... Glo Ale. Gloucester, a State Me ee oe ae Shepton or — —, 1878 30 Q | Ale. UO 0S SSS ee ie Bee seer Tide pools .. Pasacoc cee ead ae 7\Q2o¢ Alc. Casco Iii Besosocbsel adeemced |aSae seen ee Aas seen tetera Bad |odssis- Ale. 1919 | Eastport, Me....-.-.-. L. w. | Under stones ---. 1868-1870 1G | peseoe Ale. 1918 aco ay Men Dap |ssecess- Tide pool ..-..--.- — —, 1872} U.S. ish Com, Bh sane- Ale. slan 1912 tee Peers eed ee aceines te semmiene aemiete seein < o0n a | osasine cle caet nee eee pee pee na cecee. D.C. Eaton. -.. 2 Ale. 1963 | Long Island Sound, 4 Sand 27222. coseee Aug. 3,1874| U.S. FishCom. 2 | Ale. oft Saybrook, Conn. 1964 | Off Stonington, Conn.. 5 Sand and gravel.| Aug. 14, 1874 |..-.do ........- 12 | Als. 1959 | Noank Harbor, Conn...|........ Surface ......... July 13,1874 !....do ......... 90 «| Ala oT a ae MARINE ISOPODA OF NEW ENGLAND, ETC. 347 Specimens examined—Continued. 3 a So a $ ; = When col- Received s = | Dry. a Locality. a Bottom. lected. from— g | Alo, 5 a g A eal Ae 1960 | Noank Harbor, Conn..|........ Eel-grass ......- Aug. 28, 1874 | U.S. FishCom. 3 Alo. UE eG SU eG Ga ee ee a Se — —,1874 MdO\s ccwtoee 8 Ale. MIP IUN UO ETE E dks Meow sles ecccs|Pocccoccavcecceces Oct. —, 1872 ‘D.C: Eaton. - 2 Alea, 1965 | Vineyard Sound Mass Ee ee etoeetis Soc naoe — —,1875/ U.S. Fish Com. 1 Alo. PUI SS aR SS SIGS ee A ee ee eee — —,1875]....do ...-...... 7) Alles 2153 PALO eee tats rete iat or elaine hs [eile seine heise cic a'n Oct. 24, Ut yA eas (yee 2 eee 00 Ale. 1968 | Provincetown, Mass...| L.w. |...-...---.------- —— —,1872| Smith & Harger 2 | Alo. SED See eS ee PINOLO eee ss cece Aug. —,1879| U.S. FishCom.} 00 Alo. AS a eee, eG Wral sean onacesacanmase Aug. —, 1879 |....do ......... 00 Ale. el Giastcawebececs tosen| tutte wade Eel-grass Anes — 1819): <5.d0 cesses see 00 Ale. 0 Ce eee She tle SS ae es a Sept. 4)0870,2 dO. anes. cae LO Pate 426 Beverly, hhh ee a se lie eeeb i Ee Sake Eh ap eere aie A. E. Verrill.. 8 Ale. Gloucester, Mass......|.....-.. Tide-pool — —, 1878) U.S. Fish Com. 2 Alo. Gloucester, Mass., | 7-10 Sauls red algw ..) —— —,1878]|....do ......... 00 Alo. Outer Harbor. Between Boon Island ;........|.......-.-----.-.- — —,1878 hg G.H. Mar- 5 | Alo. and Matinicus Rocks. SHRUOPEEN RED et en css). cle ate}/.| ons oneine te cassects — —,1873| U. ‘s Fish Com. 12) |RAdo: 1975 | Casco Bay, Ram I ..... TW odes see son cote = — —,1873|..-.do --.....-.. 4 Ale. 2150 | George’s Bank......... let, lest cosneese tases oe Sept. —, 1872 Smith & Harger 6 | Alo, 1977 | Bay of Handy; c.- 00 <- Ta nel RSA GR oe DISCO IOOr — —,1872/ U.S. FishCom. 2 Alo, sf. MPa OUMELAIUIAA: NG So \0cccc|esccaace| cosas sudecbeesass — —,1877}..--do......... 1 Alo, POON POV OCOUA —e--.22--| La We |i--cecceccesececs — —,1877 SAO Vase cae al Alo. PATNA CORSE LEP LAN; Lo.4- 2c) ..csessccmesupecec|ascdecnteeesac Rev. A. M.Nor- 4 | Alo. man. ie NEUE GL Ge Cee Re ioe Se Pe ee ee coe Jardin des 1 |Ale Plantes. | | | Idotea phosphorea Harger. Idotea phosphorea Harger, This Report, part i, p. 569 (275), 1874; Proc. U.S. Nat. Mus., 1879, vol. ii, p. 160, 1879. Verrill, Am. Jour. Sci., III, vol. vii, pp. 43, 45, 131, 1874; Proc. Amer. Assoc., 1873, pp. 362, 367, ay 1874; This Report, part i, p. 316 (22), 1874. Whiteaves, Am. Jour. Sci., III, vol. vii, p. 218, 1874; Further Deep-sea Dredging, Gulf of St. Lawrence, p. 15, ‘1874.” PuaTE V, Fies. 27-29. This species may be distinguished from the others on this coast by the pointed abdomen or pleon. Young individuals sometimes re- semble the young of J. irrorata, but may still be distinguished by the epimeral sutures of the second and third thoracic segments, which do not entirely cross the segment, but allow more or less of the poste- rior part of the edge of the segment to form a part of the margin of the animal as seen from above. From Synidotea nodulosa it may be distin- guished by the evident epimeral sutures and by the three acute teeth at the base of the pleon on each side, instead of a single obtuse tooth, as in that species. For characters separating it from the other Isopoda of the coast see at the close of the description of the genus. The body, especially of the young, is rough and tubercular along the median line and often also laterally. Older specimens are much smoother, losing their large median tubercles but never becoming as smooth as in the preceding species. The head is narrowed behind. The eyes are of mod- erate size. The flagellum of the antenne (pl. V, fig. 28 a) is shorter than 348 REPORT OF COMMISSIONER OF FISH AND FISHERIES. the peduncle, and consists of about ten to fourteen segments. The maxillipeds (pl. V, fig. 28 b) have the external lamella (/) broader than in the preceding species, with its inner margin straight and its outer mar- gin curving pretty regularly to a slightly attenuated tip. The epimera of the second, third, and fourth pairs are rounded behind, and those of the last three pairs are less acute than in J. irrorata. Pleon ovate, a little constricted near the middle and pointed, its three proximal segments rather less acute than in the preceding species. The basal plate of the operculum (pl. V, fig. 28 e) tapers toward the end, and the terminal plate is triangular, a little longer than broad. The stylet on the second pair of pleopods in the male (pl. V, fig. 29 s and s’) is slender, nearly straight, surpasses the lamella to which it is attached, and is obliquely truncate. Length 25""; breadth 7™™. The color is very varied, usually dark green or brownish, with patches of yellow or whitish, transversely or obliquely arranged. I have never observed a striped pattern of color- ation, so common in J. irrorata, and it must occur very rarely if at all. The color is usually darker than in that species. This species is found associated with the last among rocks and sea- weed along the entire coast of New England! and extends northward to Halifax!, Nova Scotia, and the Gulf of St. Lawrence!. It appears to be a more northern species than J. irrorata, as it is comparatively rare south of Cape Cod, while it is abundant in Casco Bay, Maine, and in the Bay of Fundy. Specimens examined. | Speci- a o Wh 1 mens. F Locality. § Bottom. legs a ~ |Receivedfrom— Ale. ~~ 3 : S Fi g No. | Sex. 1980"|'‘Southind; New Ha-)|.- 0. c2|-sceccenccce oc] Nov. —, 1874 | A. E. Verrill...|..--j------] Ala ven, Conn. 1981 Stony Creek iConne. |i 5 aa-2-|seesee aces anes eons Sept. 23, 1874 |..-.do --...---.]--.-|-..-.- Ale. 1983 | OffSaybrook,Conn .| 4 Sande oos.2-..--- Aug. 3, 1874 ‘U.S. FishCom.|.-..|-.-... Ale, 1984 | Long Island SORT Ill ein ns cE 9 a a Amo NLO 1674 oOo ne neces 3] y-. | Ale 1985 | South Fisher’s Isl- OF) fesetis< esewsceedecs Aug 21 1874)\.2.d0)t..-.s+ ieee aoe Alc. | and. 2087"! Vineyard ‘Siominid, i|itseoe. ce |te--sseese enone — + —, 1871 |2--2do 2-2-5 --t acs] --eete Alo, ' Mass. i 1986 GO sae: rennet [eps cel ae aS 23 eee) 1872 [222 dO! 5526. nc]- cae] eoeene | Alo. 2147 |....do. =| Pere gle as 5 Ne Se earl eae Seeger ryyde eee ee | Alc. 1990 | Off Nantucket ...... 15 PM eect eetenceeecss MON bh.) S, LOW. dO seo cee 1; y-. | Alo Cape Cod Bay......- |. "4 Green mud....-.. Sept. 15, 1879 U. ¢ etre eee lee | Ale, PPO 8 tee eenccencc: 7 fous yellow | Sept. 15, 1879 |....do ......... | 3) | eae | Alc. sand. | j | Paral abant, MARS: oe co lo x wcjoctd ano me ee eee eee | aoeeeenee tee A.E. Verrill...)' 3 |----<- Ale, Gloucester, Mass - 7-10 | Sand and alge ..;,—— —, 1878) U. . FishCom. 00 Id Yy-| Ale. | Ten Pound Island, ode saw elle er ee ee Seen at 1978 ||. Ole can lace Coe aleneeme Alo. Gloucester, Mass. i nal pegs Mass. - % (Ob eer — —,1878| A. Hyatt ...... Pl eee Ale. 1991 | Casco Bay, Me 5 :| Aug. 4,1873!U.S.FishCom.| 1] y. | Ale. Meemmedy eee tere |. ...dp 210 ask area | Alc. 1993 | Casco Bay, > oa bey ee ee 4 esnaed Alo. Island. 7904) | «Gav ot Man diy. <6] gaan kei Seok ace Sock ember eae de) 5) i 25 eral 1) 9) Ale Bay of Fundy, Whit- ee ad oboce 5 cee at Sy PA Tees 00 | ¢? | Ale. ing River. Off Halifax, N.S - Se “| sceeews concen ee 1ST Gh |e, 3200's oh accee ranlesses Alc, Egmont Bank, ST! PONE] ARRIGO” — -, Dien J.F.Whiteaves.| 1 |....-- Alc. of St. Lawrence. ee 2 eS eS 7 "> — i i MARINE ISOPODA OF NEW ENGLAND, ETC. 349 Idotea robusta Kroyer. ? Idotea metallica Bosc, Hist. nat. des Crust., tom. ii, p. 179, pl. 15, fig. 6, 1802. Idothea robusta Kréyer, Naturhist. Tidssk., II, B. ii, p. 108, 1846; Voy. en Seand.,. Crust., pl. 26, fig. 3, ‘‘1849.” Reinhardt, Grénlands Krebsdyr, p. 35, 1857. Stimpson, Proc. Acad. Nat. Sci., 1862, p. 133, 1862. Verrill, Am. Jour. Sci., III, vol. ii, p. 360, 1871; This Report, part i, p. 439 (145), 1874 (Idotea). Harger, This Report, part i, p. 569 (275), pl. v, fig. 24, 1874; Proc. U.S. Nat. Mus., 1879, vol. ii, p. 160, 1879 (Idotea). Liitken, Crustacea of Greenland, p. 150, note, 1875. PLATE VI, Fias. 30-32. This species is easily recognized within the genus by the pleon, which is broadly truncate at the apex and not at all pointed. The pleon is also. large and more swollen above than in the other species. For characters. separating it from other Isopoda, see near the close of the generic des- cription. The entire upper surface, except perhaps that of the pleon, is some- what rugose. The head is nearly square, with the eyes large and prom- inent. The antenne (pl. VI, fig. 31 a) have the second segment large, the- flagellum short, usually of less than ten articulations. Under a sufficient power these organs are seen to be clothed with a very fine close pubes- cence, which also occurs in a less degree upon thelegs. The maxillipeds. (pl. VI, fig. 32 a) have the external lamella (/) short and oval. The legs are robust and spiny. The epimera, projecting, give a ser- rated appearance to the sides of the thorax, as seen in figure 30, plate VI, and the dorsum is more convex than in the other species. The pleon is large and convex, its sides are nearly parallel beyond the- middle, and it is broadly truncate, or even somewhat emarginate, at the- apex. The basal plate of the operculum (pl. VI, fig. 31¢) is elongated, with parallel sides; the terminal plate less than one-fourth as long and nearly square, but tapering slightly and somewhat broader than long. The male stylet on the second pair of pleopods (pl. VI, fig. 32 ¢, s) reaches. the end of the lamella, to which it is attached, and is slightly curved and rounded at the tip. Length of male 28™™; female 22™™; breadth 9™™. Color bright blue or green above when alive, becoming darker and dull in alcohol, with- out the markings of the other species, but often with metallic reflections, when seen in the water, where it is commonly taken swimming free or among masses of floating sea-weed. It is thus found in mid-ocean, and was described by Kroyer from speci- mens taken in about 60° north latitude between Iceland and Greenland. It was taken in considerable abundance at Fire Island Beach!, on the south shore of Long Island, by Professor 8S. I. Smith in 1870; also by the U. S. Fish Commission at Vineyard Sound!, Mass., often in company with I. irrorata Edw.; at George’s Banks!, September, 1872, small specimens, 5™™ in length; between Boon Island and Matinicus Rocks, near the 350 REPORT OF COMMISSIONER OF FISH AND FISHERIES . Isles of Shoals!, by Capt. G. H. Martin, of the schooner ‘ Northern Eagle,’ in 1878, and at Halifax!, Nova Scotia, by the U. S. Fish Commission in 1877, whence it extends to at least 60° north latitude. The figure and description of Idotea metallica given by Bose corre- spond well with small specimens of this species such as were taken by Professor 8. I. Smith and the writer on George’s Banks, and the locality he gives, “the high seas,” corresponds also with the habit of this species, so that I am inclined to think that his name ought to be restored. I have, however, retained Kréyer’s name, since he so thoroughly described and so well figured the species as to leave no doubt of its identity. Specimens examined. Speci 3 mens a Locality. Habitat. Whenool: Receivedfrom—|__ eye E No.| Sex. 1080 | Fire Island Beach, Long Island ...| Surface....]—— —, 1870} S. I. Smith..... 46 | hQ | Alo 1998 | Vineyard Sound, Mass :2.21. 22.00! Surface....] —— —,1875| U.S. FishCom.| 1 |.-..---. C. The eee OE Eee Oe See Seer Soe 5 epee Surfaces--4|-be esto ses-cclaaee dor? 3.528 00| So | Ale. iB Aa ie ARB TOE Surface. ... July 1 AY ee) aes 7) {leecoci: Ale. AOD R se OO. 350 sbi Haake ph ane ease Sector Surface....| Oct. 24, 1875 | V. N. Edwards | 00 |...... Ale. ZOO SS MOY woe ee tn ace Sa titensctee ame me Surface....| Nov. 16, ayy ee ns Suse O0)| 222 eee Ale. 2000 George’ BS Bank. 5..s€patten meet kos Surface. ...| Sept. —, 1872 Smith & Harger 4) y. | Ale. 00K | Hinlttax, IN. S* eee. os ssemeecs o= = Surface....}—— —,1877} U.S. FishCom.| 1 |...... Ale. Synidotea Harger. Synidotea Harger, Am. Jour. Sci., III, vol. xv, p. 374, 1878. Antenne with an articulated flagellum; epimeral sutures not evident above; pleon apparently composed of two segments, united above but separated at the sides by short incisions; operculum with a single api- cal plate; palpus of maxillipeds three-jointed. Of the two species that I had referred to this genus I had been able to examine only the first when this paper was placed in the hands of the printer. Two specimens of the second species were collected during the summer of 1879, and an examination of their characters leaves no doubt of their generic affinity. Except in the particulars above specified the description already given of the genus Jdotea will in general apply also to the present, but the species are characterized by a firmer and more solid structure, the segments being more closely articulated and the integ- ument having a somewhat shelly appearance. The pleon is further con- solidated than in that genus, the only trace of its composite nature, as seen from above, being a slight incision on each side near the base and running up somewhat obliquely toward the dorsal surface. The well- developed and distinctly articulated flagellum of the antennz serves easily to distinguish the speciegfrom those of the following genera of the family. q ‘ « \ a MARINE ISOPODA OF NEW ENGLAND, ETC. 351 Synidotea nodulosa Harger (Kroyer). Idothea nodulosa Kroyer, Naturhist. Tidssk., II, B. ii, p.100, 1846; Voy. en Scand., Crust., pl. 26, fig. 2, 1849. Reinhardt, Gr@énlands Krebsdyr, p. 34, 1857. Liitken, Crust. Greenland, p. 150, ‘¢1875.” Synidotea nodulosa Harger, Am. Jour. Sci., III, vol. xv, p. 374, 1878; Proc. U.S: Nat. Mus., 1879, vol. ii, p. 160, 1879. PLATE VI, Fias. 33-35. This species may be recognized most easily by the pleon, which is en- tire, except for a slight incision near the base on each side, and tapers to a blunt but not at all bifid point. The articulated flagellum of the antenne distinguishes it from Prichsonia. The head and body are roughened and tubercular, having a prominent median row of tubercles and coarse rug along the sides of the thorax. The head has a median notch in front, and immediately above this a prominent tubercle directed forward, and succeeded on the median line by two less prominent tubercles. In front of each eye is a still larger tubercle, directed forward and projecting over the anterior margin of the head ; behind and within, there are two smaller oval tubercles. The eyes are large, convex, and very prominent. The peduncular segments of the antenne (pl. VI, fig. 340) increase gradually in length from the first and decrease in diameter from the second, which lacks the lateral in- cision seen in Jdotea. The flagellum is distinctly articulated, with about nine segments, of which the last two are very minute. The maxillipeds (pl. V1, fig. 35 a) have the external lamella (1) of an irregular shape, emargi- nate on the inner side and obtusely pointed. The outer maxille (pl. VI, fig. 35) are armed on their external lobe with strong, curved, pectinated sete, which become much elongated and stout at the tip of the lobe. The inner maxillz (pl. VI, fig. 35 ¢) resemble these organs in other mem- bers of the family. The first four thoracic segments have their external margins rounded. In the last three the margins are more nearly straight, but with rounded angles. The first pair of legs (pl. VI, fig. 34 ¢) are much shorter than the second, and the propodus in the first pair is bristly on what is, in the ordinary position, the upper side. The pleon is short, and tapers from the base. It is convex, bears two or three small tubercles on the median line near the base, and an im- pressed transverse line in continuation of the short lateral incisions. The basal plate of the operculum (pl. VI, fig. 34d) is oblique at the base with rounded angles, and is somewhat vaulted, with an oblique elevation extending from the articulation to the inner distal angle. The inner margin is straight, and the outer parallel with it to near the end. The terminal plate is slightly oblique at the base, and is elongated triangular, about twice aslong asbroad. ‘Che free margins are finely ciliated, except at and near the base, and the iimer margin of the basal plate bears also scattered stouter hairs. The stylet of the males on the second pair of pleopods (pl. VI, fig. 35 d, s) is longer and stouter than in any of our species 352 REFORT OF COMMISSIONER OF FISH AND FISHERIES. of Idotea. It is nearly twice the length of the lamella, to which it is attached, and of an elongated spatulate form tapering to an obtuse point. The lamellz are provided with but few cilia, which extend less than half the way from the end of the lamella to the end of the stylet. Length 10.5"".; breadth 3.5°". Females proportionally broader ; length 8.""; breadth 3™. Color in alcohol gray, often with brown- ish transverse markings. This species seems to agree with Idotea nodulosa Kroyer, from South- ern Greenland, as described and figured, except that the epimeral sutures are not evident above ; the lateral margins of the segments are, however, somewhat thickened and prominent with rug, as shown in his figure, and I have no doubt that it is the same as his species. It was dredged off Halifax! by the Fish Commission at several localities in the summer of 1877, in from 16 to 190 fathoms on sandy and rocky bottoms, with red algze at one locality. A specimen was brought from George’s Banks! by Mr. Joseph P. Schemelia, of the schooner ‘Wm. H. Raymond,’ in the summer of 1879, and Mr. J. F. Whiteaves has sent to the Museum for examination two specimens collected by Mr. G. M. Dawson, in 111 fathoms, Dixon Entrance!, north of Queen Charlotte Island, British Columbia. The range of the species would therefore be, as at present known, from George’s Banks to Greenland and the Arctic Seas, and southward on the Pacific coast as far as British Columbia... Specimens examined. Speci gC Q mens: ca) . g When col- A TY; F Locality. 5 Bottom. leaind: Received from—} ee jae: A & o.| Sex iron Entrance, Q. MM Wee ec cnecatecisecceshscctecscesecic¢ J. F. Whiteaves} 2 |.....- Ale. 2006 | Off Halifax, WaS.ces] 16 Shomes, sand, red | —— —,1877| U.S. FishCom.} 2 |...... Alc. alge 2007 | South of Halifax, 120 | 190 Gravel and peb- | Sept. 1,1877|....do ..--....- 1} Q | Ale. miles. es Halifax,outerharbor} 18 Sand, stones - Sept. 4,1877|..--do ......... 2 | acer Ale. 2008)| = ..00). eos nseeeceee 16 Rocks, nullipore Sept. 4, 1877 100) 45-55-55 a | pase Alc. George's Banks. -fcchicdie -tdlosaasnwasccce cscs — —,1879 J.P. Schemelial 1 Q | Ale. Synidotea bicuspida Harger (Owen). Idotea bicuspida Owen, Crustacea of the Blossom, p. 92, pl. xxvii, fig. 6, 1839. Streets and Kingsley, Proc. Essex Inst., vol. ix, p. 108, 1877. Idotea marmorata Packard, Mem. Bost. Soc. Nat. Hist., vol. i, p. 296, pl. viii, fig. 6, 1867. Whiteaves, Further Deep-sea Dredging in Gulf of St. Lawrence, p. 15, 1874. Idotea pulchra Lockington, Proc. Cal. Acad. Sci., vol vii, p. 45, 1877. Synidotea bicuspida Harger, Proc. U. 8. Nat. Mus., 1879, vol. ii, p. 160, 1879. This species may be most easily recognized among the known Isopoda of our coast by the form of the pleon, which is nearly triangular in shape, marked by a slight incision at each side near the base, and dis- tinctly bicuspid at the tip. MARINE ISOPODA OF NEW ENGLAND, ETC. 390 The body is rather more robust than in the last species, the length being only about two and a half times the breadth, and is peculiarly marked above by depressed and mostly curved lines, varying in length but mostly short, and confined principally to a region on each side of the median line and extending across the head but not the pleon. The head is broadly emarginate in front, with a median notch, and its antero-lateral angles are prominent. The eyes are at the widest part of the head, and are strongly convex. The posterior outline of the head is nearly in the form of three sides of a hexagon. The antennule attain about the middle of the fourth antennal segment. The antenne are about one-half as long as the body. The first two antennal segments are short and apparently articulated so as to admit of but little motion ; the third segment is a little longer than the first two taken together, and is the largest of the antennal segments in diameter; the fourth segment is somewhat longer than the third, and the fifth or last pedun- cular segment is the longest, and is followed by a flagellum, a little shorter than the peduncle and composed of about fourteen segments. The last three peduncular segments of the antennz are somewhat bristly hairy. The maxillipeds are nearly as in the preceding species. The outer maxille are destitute of the elongated, pectinate sets found in that species. The thoracic segments vary but little in length measured along the median line, but the fifth, sixth, and seventh are slightly shorter than the preceding ones, and this difference is still greater measured along the margins of the segments, where the first is longest, the next three _ about equal, and the last three shorter. The legs are robust, the first pair shortest, and all more or less bristly hairy. The lateral margins of the segments are much less rounded than in 8S. nodulosa. The pleon is short, the length being scarcely greater than the breadth at base; above, it is nearly smooth, the impressed lines, so conspicuous in the lateral region of the thorax, being continued for but a slight dis- tance upon its surface. The incision at each side near the base is con- tinued upward and forward by a depressed line on each side; the lateral Inargins are gently convex to near the tip, which is distinctly bicuspid. The basal plate of the operculum is traversed obliquely by a longi- tudinal ridge on the external surface, and is rounded in front, slightly narrowed behind, and bears a short, triangular, terminal plate, its length being but little greater than its breadth. Length 15.5""; breadth 6°". Color in alcohol grayish, with white cloudings. Lockington says: ‘‘ When recent, the coloration of this spe- cies is very beautiful, consisting of red cloudings on a lighter ground.” There seems to be no doubt in regard to the synonymy of this species as published by Streets and Kingsley, adopted by the writer in a previous publication, and given above. The only specimens that I have examined were two, brought from the Grand Banks!, in the summer of 1879, by Mr. Charles Ruckley, of the 23 ¥F 304 REPORT OF COMMISSIONER OF FISH AND FISHERIES. schooner ‘ Frederick Gerring, jr.’, Capt. Edwin Morris. Dr. Packard’s locality is “Sloop Harbor, Kynetarbuck Bay [Labrador], seven fathoms on a sandy bottom.” Whiteaves records the species from Orphan Bank, Gulf of Saint Lawrence. Lockington’s specimens were collected on the “west coast of Alaska, N. of Behring’s Strait, by W. J. Fisher, natu- ralist of the U. 8S. S. Tuscarora, Deep-Sea Sounding Expedition.” Owen’s locality is “‘ the Arctic Seas.” Erichsonia Dana. Erichsonia Dana, Am. Jour. Sci., II, vol. viii, p. 427, 1849. Antenne six-jointed, the terminal or flagellar segment not articulated, clavate; palpus of the maxillipeds four-jointed; legs all nearly alike, prehensile or sub-prehensile ; pleon with its segments consolidated into a single piece. This genus is represented within our limits by two well-marked spe- cies, which further agree in the following characters: The head is quad- rate, with the eyes lateral. The antennule are short, not surpassing the third segment of the antenne. The antennz are well developed, more than half as long as the body, with a very short basal segment articu- _ lated with little or no motion to the second segment, which is two or three times as long as, and of greater diameter than the first. It is, as usual in the family, incised at its distal end on the under surface. The next three segments are nearly cylindrical. The last or flagellar seg- ment is the longest, and is slightly clavate. The legs are all terminated by a prehensile or sub-prehensile hand, the dactylus being capable of considerable or complete flexion on the more or less swollen propodus. This flexion is most complete in the first pair. The first two pairs of legs arise near the anterior margin of the segments to which they belong. The place of attachment to the segment moves gradually backward in the following pairs until the last two pairs arise near the posterior margin of the last two segments. The epimera are more or less evident from above, at least in the last two segments. The pleon constitutes about one-third the length of the body, and is consolidated into a single piece; it bears a more or less evident tooth on each side near the base, and is dilated and obtusely triangular at the apex. The basal plate of the operculum is oblique at the anterior end and abruptly narrowed posteriorly, where it bears a densely plumose bristle, as in Idotea ; the terminal plate is triangular. The stylet on the second pair of pleopods in the males is well developed, surpassing the cilia; it is minutely denticulated or spinulose near the end and very acute. The two species found on our coast have but a slight external resem- blance to each other, and may be distinguished at a glance, as will be seen from the specific descriptions, and from the figures (pl. VI, fig. 36, and pl. VII, fig. 38). The long, clavate terminal segment of the antenna = MARINE ISOPODA OF NEW ENGLAND, ETC. 355 distinguishes them at once from young specimens of Idotea, especially I. phosphorea, which sometimes resemble LZ. filiformis. This character of the antenne serves, indeed, to distinguish the two unlike representa- tives of the present genus from all the other Isopoda of our coast. Erichsonia filiformis Harger (Say). Stenosoma filiformis Say, Jour. Acad. Nat. Sci., vol. i, p. 424, 1818. Edwards, Hist. nat. des Crust., tom. iii, p. 134, 1840. Dekay, Zool. New York, Crust., p. 44, 1844. Idotea filiformis White, List Crust. Brit. Mus., p. 95, 1847. Erichsonia filiformis Harger, This Report, part i, p. 570 (276), pl. vi, fig. 26, 1874; Proc. U. 8S. Nat. Mus., 1879, vol. ii, p. 160, 1879. Vertill, This Report, part i, p. 316 (22), 1874. PuaTE VII, Fias. 38-41. This species may be at once distinguished from the following by the strongly serrated outline of the sides, as seen from above. The clavate terminal segment of the antenne distinguishes it from the other known Isopoda of our coast. The body is slender and elongated, but less so than in the next spe- cies, the sides are nearly parallel and there is a median row of promi- nent tubercles, one, large and bifid, on the head, and one upon each thoracic segment. The eyes are prominent. The antennule (pl. VII, fig. 39 a) surpass the middle of the third antennal segment. The first segment of the antenne (pl. VII, fig. 39 b) is very short; the terminal segment is bristly hairy toward the apex. The external lamella of the maxillipeds (pl. VI, fig. 41 a) is emarginate on the outer side toward the apex. The thoracic segments each bear a prominent median tubercle near their posterior margins, and the first bears also a smaller tubercle near its anterior margin. In the first two segments the posterior external angles are salient and much elevated. The angulated epimera are evi- dent from above in front of these projections. In the third and fourth segments both lateral angles are salient but not elevated. In the last three segments, only the anterior angles are produced, but the epimera fill the places of the posterior angles. This arrangement gives the appearance of fourteen teeth upon each side of the thorax, and the prominent divergent tooth on the pleon makes, in all, fifteen. The operculum (pl. VII, fig. 39 d) is a little more vaulted than in the next species and shorter; the basal plate is less than three times as long as broad; the terminal plate is triangular. The stylet on the second pair of pleopods in the male (pl. VII, fig. 41 b, s) is slightly eurved, finely spinulose near the apex on the side toward the lamella, and minutely and sharply denticulate on the opposite side at the apex, as shown in the enlarged figure (s’) of the distal portion of the stylet. Length 11™™; breadth 3.4™". The color is a usually dull neutral tint without bright markings, but sometimes more or less variegated with brown or reddish, fading in alcohol. 356 REPORT OF COMMISSIONER OF FISH AND FISHERIES. This species was originally described from Great Egg Harbor, New Jersey, where Say found it in company with Idotea irrorata. It is not uncommon along the shores of Long Island Sound! and as far east as Vineyard Sound, Mass.! but has not yet been found north of Cape Cod. It is usually found in tide-pools or among eel-grass and alga, and has been taken from a depth of 7 fathoms. Specimens examined. ' ; | og B Fs When col- ; SH |D = Locality. g Bottom. | lected. |Receivedfrom— 2 3 ri B & =} A A” | 2010" | Longuisiand Sound a| (2. ose ca| sac oe cee neces so | Same e kei neemien toot seca mee eer 00 Ale. 2014))| ehhimbledslands onal. oo sel sees Sos seeee ese eel Se maceme neers A. E. Verrill. - | epee) dls, 2012 | Long Island Sound, 7 Sand and shells .| —— —, 1874 U.S. FishCom. 1 Ale. Fisher’s Island Sound. 2013 | Long Island Sound..| 43 Sand and gravel.| —— —, 1874 |....do ......--- 2 Ale. iE om G ett) pom sos ees 6 see loceadsna|laéadse goqhe Soc deb — —,1874|....do ........- 1 Ale. 2015 al hee ed O) aes so ase sae eerie sae] Seinelieem cine Seema Sept: 10i1874 |fe-sdOe os. eee 2 Ale. 2016) | Noam Kees se eset eeccecas Eel-grass ..-...- —— —,1874|....do .......-- 2 Ale 2017 | Vineyard Sound ..-..}.-----.-|....--------......| —— —, 1875 |....do -.......-. 2 Alc. Erichsonia attenuata Harger. Erichsonia attenuata Harger, This Report, part i, p. 570 (276), pl. vi, fig. 27, 1874; Proc. U. 8. Nat. Mus., 1879, vol. ii, p. 160, 1879. Verrill, This Report, part i, p. 370 (76), 1874. PuaTEs VI and VII, Fies. 36 and 37. This species is at once distinguished from the preceding by its slender form and regular outline; the clavate antennal flagellum distinguishes it from other Isopoda. The body is smooth throughout and about six times as long as broad, without prominent irregularities and narrowly linear in outline. The eyes are small and black. The antennule (pl. VII, fig. 37 a) are short, slightly surpassing the second antennal segment. The antenne (pl. VII, fig. 37 b) are stout and smoother than in the preceding species. The external lamella of the maxillipeds (pl. VII, fig. 37 ¢, 1) is oval and regularly rounded at the tip. The thoracic segments increase in size to the third, which is equal to the fourth, and the last three are of a gradually decreasing size. The epimera are nowhere conspicuous, but may usually be seen from above, pspecially in the posterior segments. The pleon presents only slight traces of a lateral tooth near its base wd is but little dilated toward the tip. The operculum (pl. VI, fig. d7 d) is longer than in the preceding species, the basal plate is more than three times as long as broad, the terminal plate elongated trian- gular and obtuse. The male stylet on the second pair of pleopods (pl. VII, fig. 37 e, s) is nearly straight, hardly surpasses the cilia, and is minutely denticulated near the acute apex. eee MARINE ISOPODA OF NEW ENGLAND, ETC. B57 Length 15™"; breadth 2.5™™. Alcoholic specimens are of a light grayish yellow, with minute black punctations. It was abundant in eel-grass at Great Egg Harbor, New Jersey! in April, 1871, and has also been found at Noank, Conn.! on eel-grass, but isnot common. It has not been found north of Cape Cod. Specimens examined. Speci a aD mens a) . Fs When col- P dil . F Locality. E Bottom. jected Receivedfrom alge Als A & o.| Sex 1226 ig Egg Harbor, |-.---.---- Eel-grass ....--- Apr. —, 1871 | S. I. Smith..... (00222252 Ale. 2018 Noank, Conn 3.27 foe. 44150 3 GOR easiest ras erent 1874 | U.S. FishCom.| 1 Q | Alc. Epelys Dana. Epelys Dana, Am. Jour. Sci., II, vol. viii, p. 426, 1849. Antenne shorter than the anntennule and with only a rudimentary flagellum; palpus of the maxillipeds three-jointed ; legs all terminated with prehensile hands; pleon consolidated into a single segment with a basal lobe on each side. Two small and closely allied species from this coast have been referred to this genus. They resemble each other very closely and may be at once recognized by their depressed ovate form, very short antenne, and generally dirty appearance. The form of the body and absence of power- ful mandibles distinguish them from the male Gnathia. The length of the body is between two and three times its width. It is marked by a de- pressed line on each side, running from the posterior part of the head, across the thoracic segments, nearer to their lateral margins than the median line, except perhaps in the last segment, thence continued to in- close a prominent hemispherical protuberance on the anterior part of the ' pleon, giving the animal somewhat the appearance of a trilobite. The body is slightly roughened under a lens, or sometimes minutely hirsute. The head is slightly dilated at the sides, with the anterior angles pro- duced, and bears a pair of broad, low, triangular tubercles on its anterior part, and acurved posterior depression. The eyes are lateral and prom- inent, the antennule are longer than the head, surpass the antenne, and have the basal segment but little enlarged. The antenne (pl. VIII, fig. 45 b) are shorter than the head, not surpassing the third antennular seg- ment, the segments increasing in length to the fourth; fifth as long as the fourth, but more slender, bearing a minute, slender rudiment of a flagellum, which is setose at the tip. The thoracic segments have thick evident margins; first segment smallest, somewhat embracing the head; third and fourth largest; 358 REPORT OF COMMISSIONER OF FISH AND FISHERIES. last segment curving around the base of the pleon. The epimera are not evident from above. The legs (pl. VIII, fig. 46 a) are slender and. all terminated by a slender prehensile hand, of which the finger, or dactylus, becomes almost acicular in some of the posterior pairs. All the legs are more or less hairy. The pleon bears on each side, near its base, a rounded lobe, which is separated from the large posterior portion by a more or less evident incision. Dorsally it is convex, and presents two hemispherical eleva- tions, the proximal more convex than, but only half as large as, the distal. They are separated by a broad and deep groove, and the distal convexity is continued upon the obtusely-pointed apex of the pleon. The operculum (pl. VITI, fig. 46 b) is vaulted; its basal plate is rounded. anteriorly, carinate near its inner margin, contracted externally for the distal third of its length and truncate at the tip, where it bears a stout elongated-triangular finely ciliated terminal piece. The basal plate is coarsely ciliated on its inner margin, and bears a few plumose hairs along its outer free margin. The stylet on the second pair of pleopods in the males is short and stout, surpasses the lamella but not the cilia, and is spinulose just below the blunt apex. Both species are of a dull neutral color, and commonly covered with particles of mud or other foreign matter. They occur on piles, or under stones, in muddy places, and are dredged on muddy bottoms. Bpelys trilobus Smith (Say). Idotea triloba Say, Jour. Acad. Nat. Sci. Phil., vol. i, p. 425, 1818. Edwards, Hist. nat. des Crust., tome iii, p. 134, 1840. Dekay, Zool. New York, Crust., p. 43, 1844. Leidy, Jour. Acad. Nat. Sci., II, vol. iii, p. 150, 1855. Jaera? triloba White, List Crust. Brit. Mus., p. 97, 1847. Epelys trilobus Smith, This Report, part i, p. 571 (277), pl. vi, fig. 28, 1874. Verrill, Am. Jour. Sci., III, vol. vii, p. 135, 1874; Proc. Amer. Assoc., 1873, p. 372, 1874; This Report, part i, p. 370 (76), 1874. Harger, Proc. U. 8. Nat. Mus., 1879, vol. ii, p. 160, 1879. PLATE VII, Fias. 42 and 43. This species may be recognized among our Isopoda by its appearance when seen from above, recalling the form of the trilobites, the flattened dorsal surface being marked, as in those animals, by two lateral longi- tudinal depressions. The pleon is consolidated into a single piece and the antennze have only a rudimentary flagellum. It closely resembles the next species, but is smaller and most readily distinguished by the lateral margin of the thorax, which is, especially in the anterior part, nearly even instead of zigzag from the projecting angular segments. The anterior angles of the head are also less produced. The pleon is shorter and broader, its breadth being to its length as six to ten. The deep transverse groove across the pleon is continued to the margin, with only, at the most, traces of a tubercle at each side. The stylet on the second pair of pleopods of the male (pl. VU, fig. 42 8, — MARINE ISOPODA OF NEW ENGLAND, ETC. 359 s, and s’), is a little less elongated than in the next species, not attain- ing the middle of the cilia. Length 6"; breadth 2.3°", The color is uniform, dull, usually obscured by the adhering particles of dirt. 4 . . . This species was described by Say from Egg Harbor!, New Jersey, where specimens were also collected by Professors Verrill and Smith, in April, 1871, among eel-grass. It has also been found at Savin Rock!, near New Haven, and Noank Harbor!, on piles and among eel-grass; at Vineyard Sound!; Mass., at Provincetown!, Mass., near Cape Cod in e : : ny 1879; sparingly near Gloucester! Mass., in 1878, and even as far north as Quahog Bay!, about thirty miles northeast of Portland, Me., where it _ was taken by the United States Fish Commission, in 1873, along with _ Venus mercenaria and other southern forms. Specimens examined. ! = | 8 Z When col gs 3 2 Locality. EB Bottom. lected. |Receivedfrom— 25 ay = ¥ oO : 5 3 Be A Fi | a2 1227 oe! Egg Harbor, |....-..-.- Eel-grass -..---- Apr. —, 1871 | S. I. Smith..... 7 Alc. 2019 Savin Roe Naw | Tiwi }.22)-52.0-0 248 1871-1872 | A.E.Verrill ..| 2 | Alo. aven. PERE AM OS caacs| enone lone nascecn cls cacmns Aug. 12, 1874| U.S. FishCom.} 12 Alc. MOM Cy eo nd BM ade oe tN oh July 13, 1874|....do ......-.- 7. | Ale. RY) | 2. Go aS ie | On piles) 5525. - July 27,1874 |.-..do -........ 1 Ale. 2024 it Se ee ee ees Eel-grass ...-..- — —, 1874|....do ....-.... 00 Alec. Mune 2 | VMAS te) O18 1 C0 5d Cae aE SS a en eee Apr. —, 1873 ‘A. E. Verrill.- + Alc 2025 Vineyard = SSE IP SL BO aes SR Pe a — —,1871/ U.S. Fish Com. 2 Alc SE ORE GO Ao aie, 8 a Re — —, 1871} sae Os same if Ale 2027 | eae ees Nee L. w. Sand. — —,1871|.-..do ........ 2 Ale Provincetown, Mass..| L. w. |----------- Aug. —, 1879 Uv. s Fish Gom 2 Alc PEON S {5 Soo -2 82's oeeb 2 3 Eel-grass —— —, 1879|....do .....-... 1 Alc. QO fae oes sn. all veers Shore a = 1879) | Ka eS aetna 9 Ale. | Gloucester, Mass ...-..|.--..--. Tide — —,1878}....do ........ 2 Alc. 2028 | Quahog Bay, Me...... L.w. | Mu — —,1873|....do -....-... 3 Alc. Epelys montosus Harger (Stimpson). Idotea montosa Stimpson, Mar. Iny. G. Manan, p. 40, 1853. Epelys montosus Harger, This Report, part i, p. 571 (277), 1874; Proc. U. S. Nat. Mus., 1879, vol. ii, p. 161, 1879. Verrill, Am. Jour. Sci., III, vol. vii, p. 45, 1874; Proc. Amer. Assoc., 187 3, p. 367, 1874; This Report, part i, p. 370 (76), 1874. Smith and Harger, reais Conn. Acad., vol. iii, p. 3, 1874. Whiteaves, Further Deep-sea ppoapitie Gulf St. Lawsdnies) p. 15, ‘°1874.” PLATE VIII, Frias. 44-47. This species closely resembles the preceding, and may be recognized among our Isopoda by the characters mentioned under the former spe- cies, from which it is distinguished by the following characters: The eyes are prominent; the anterior angles of the head salient. The tuber- cles on the head are more prominent than in the former species. The lateral margins of the thoracic segments, especially the second, third, and fourth, are angulated and salient. The pleon is more elongated 360 REPORT OF COMMISSIONER OF FISH AND FISHERIES. than in the last species, its breadth being to its length as 5.5 to 10, and the depression crossing it is partially interrupted at each side by a tuber- cle which often projects, as seen from above, just behind the basal lobe, forming a shoulder to the large terminal lobe. The stylet on the second pair of pleopods in the males (pl. VII, fig. 47, s and s’) attains about the middle of the cilia. Length 10°"; breadth 4™"; color, as in the preceding, dull, and usually much obscured by adhering dirt. A few specimens were collected in Whiting River, near Eastport, Maine, in 1872, which are much more decidedly hirsute than is usual, both on the upper surface and on the legs as well. In other respects they appear to be referable to this species, although the posterior thoracic segments are rather less angulated at the lateral margin. They may be worthy of a variety name hirsutus. Dr. Stimpson’s specimens were “taken in deep water on sandy and muddy bottoms” in the Bay of Fundy, and this species usually replaces the last in the northern localities. It has, however, been taken as far south as Block Island Sound!,near the eastern end of Long Island Sound, in 18 fathoms, sandy bottom, and in 29 fathoms Vineyard Sound !. North of Cape Cod it is more common. It was dredged in 25 fathoms on St. George’s Bank!, at Stellwagen’s Bank ! in 20 to 40 fathoms, rocky and sandy bottom; Casco Bay!, 16 to 17 fathoms mud; Bay of Fundy !, at many localities, usually on muddy bottoms, and in 16-18 fathoms mud and stones, off Halifax!, Nova Scotia, by the Fish Commission, and in 14 fathoms off Richibucto, in the Gulf of Saint Lawrence, by Mr. J. F. Whiteaves. The greatest depth positively recorded is 29 fathoms, but it may very likely have come also from a depth of 40 fathoms near Stellwagen’s Bank. Specimens examined. on oa A 4 When col 8 5 Dry. © . * n _ . oO . c Locality. s Bottom. lector: Received from— 28 Als: BR Ba A Fa mie 2029 | Vineyard Sound ....-. AO A eecieticte ere Ane ocak Sept. 14, 1871 | U.S. FishCom.} 8 Alec. 2030 | Block Island Sound. . SAAS ands sere. — —,1874|....do ......... | 1 Alc. Off Boston Harbor ..-. 16 Spepeled sand, | Sept.13, 1879 |.£..do ... ...-.-| 2 Ale. shells. Gloucester Harbor, N=Skl snc GO sweesee veee —— —,1878)|.-...do ..-.---.- | 30 Ale. ass. | 2032 | George’s Bank ....-..-. 25 ||| Peemoaclemertacetoe — —, 1872).--.......-..02- 2 Ale. 2031 | Stellwagen’s Bank ...-| 20-40 | Rocks and sand.| —— —, 1873| A. S. Packard.| 1 Alc. 2033 | Casco Bay ..-....--.-- 16) Mind Peston ee July 12,1873) U.S. FishCom-.| 00 Ale. AUNT acc 6 (ORS Seen aes aa LT? |. ses paneencem-s- FANT 30; 18%e i200 oaacucee 00 Ale. eed O) eocnPeca' costed cialis. o3e se! eee eee ee —— —, 1873 |....do .....::.. 00 Alc. B0sB. || bay of Hundy, Hast- |i.-.25-|sascesse sere e eee — —,1872)....do ......... 6 Ale. port. PEDO Were Olce 22 sais wae cence aa) jccnce EIR eee — —,1872|....do......... 2 Alc. 2040 | Bay at Fundy, Whit- 2° Mrad eo eee a — 1872 |. =. dose eee 6 Ale. ing R. 2041 | Seal. Cove, Grand| 8-10 |...........-..-.-- Bete 58 1879 L:. AOL. EEE 10 | Ale. Menan. 2042 | Off Halifax, N.S ...... 16 See sand, red | —— —, 1877 |....do ......... 4 Alec. 2. 2043 I EO Ober emacs sone 18 Mud fine sand ..| Sept. 15, 1877 |....do ......... 2 Ale. MARINE ISOPODA OF NEW ENGLAND, ETC. 361 VI.—ARCTURID 4 Form elongated; antennz large and strong; first four pairs of legs directed forward, ciliated, last three pairs ambulatory; segments of pleon more or less consolidated ; uropods opereuliform. This well marked family is as yet represented on our coast by a single species of the genus Astacilla Fleming, Leachia or Leacia of Johnston and other authors. The family can be easily recognized by the four anterior pairs of legs, which are directed forward and strongly ciliated on their inner margins with long slender hairs. The form of the body is elongate and may be very much so, as in our species the length of the body in the male is twenty times as great as its diameter at the middle; in the female eight times. The head is of moderate size and the eyes prominent. The four-jointed antennule have the basal segment large and swollen. The antenne are large and powerful organs, approaching or even surpassing the body in length, with the first two segments short, the second deeply incised below as in Idotea, the next three segments elongated, and the flagellum varying in the genera, being multiarticu- late in Arcturus, and composed of not more than four segments in Asta- cilla. The mouth parts resemble, in general, those of the [doteide. The fourth thoracic segment is more or less elongated. The last three pairs of legs are ambulatory, differing much from the first four pairs. The segments of the pleon are more or less united, and the uropods are mod- ified, as in the preceding family, to form an operculum for the more del- icate anterior pleopods. They are wholly inferior, and consist on each side of a large basal segment, straight on the median line, where it meets its fellow of the opposite side, and bearing, in our genus, two small ter- minal plates at the apex. This structure of the pleon and its appendages, together with the structure of the antennule, antennz, and the parts of the mouth, point to a close relationship between this family and the Idoteide. With the Anthuride, however, with which they have often been associated, they seem to have little in common, except, perhaps, the elongate form of body. Even this feature is approached also in the Idoteide, in Hrich- sonia, for example. Astacilla Fleming. Leacia (Leachia) Johnston, Ed. Phil. Jour., vol. xiii, p. 219, 1825 (non Lesueur). Astacilla Fleming, Encyc. Brit., 7th ed., vol. vii, p. 502. Johnston, Loud. Mag. Nat. Hist., vol. viii, p. 494, 1835. Antennal flagellum short, not more than four-jointed ; fourth thoracic segment elongated, and, in the females, bearing the incubatory pouch on its inferior surface. The characters given above seem sufficient to warrant the separation of this genus from Arcturus, notwithstanding the fact that the young of some species, and probably of all, have the fourth thoracic seg- 362 REPORT OF COMMISSIONER OF FISH AND FISHERIES. ment no longer than the others as noticed by Johnston*, and later by Stebbingt, who draws from the fact an argument against the validity of the genus. I fail to see, however, why the argument would not be equally valid against the use, among mammals, of characters drawn from the horns and teeth. Nothing is more common, in case of a genus or family possessing a special development of some organ or set of organs, than to find that the young of such a group resemble the adults of less specialized groups. If, however, as may be possible, a gradation can be established between forms which, like Arcturus Baffini, have the fourth thoracic segment large but only slightly elongated, and forms like Asta- cilla longicornis or A. granulata, in which this segment is much elongated, equaling or surpassing the other six in length, there would then be, per- haps, no sufficient reason for retaining both genera. For the present it seems desirable to keep them separate, and to the characters given above we may add the following: The head is produced at the sides around the bases of the antennula, and is united dorsally with the first thoracic segment, the sutures being evident only at the sides where the segment is produced around the hinder part of the head. The flagellum of the antenne consists of three, or sometimes only two, distinct segments and a terminal spine, which is perhaps to be regarded as a third or fourth segment. The maxillipeds (pl. IX, fig. 52 a) are robust and operculiform, with a thick external lamella and a five-jointed palpus, but little flattened. The mandibles are destitute of palpi. The first three thoracic segments are subequal and short; the fourth much elongated in both sexes; in the males it is slender and cylindrical ; in the females it is more robust, and bears on its inferior surface the incu- -batory pouch. This pouch is thus confined to a single segment, and is composed of a pair of elongated lamelle, attached along their outer mar- gins, and overlapping widely along the ventral surface. It occupies nearly the entire inferior surface of the segment. The last three thoracic segments are short and subequal, and the articulation at the posterior end of the fourth segment is capable of considerable motion, and, in our species, is usually flexed backward nearly at a rightangle. The first pair of legs (pl. VIII, fig. 49 b) have the basis directed backward and the re- maining segments ciliated and turned forward, and is more robust than the three succeeding pairs, which are slender, of nearly equal size, and con- sist of only five segments, which are turned forward from the basis and held beneath the head. They are strongly ciliated, especially on the last three segments. One of the fourth pair of legs is shown on plate VIII, figure 50. The last three pairs of legs are of entirely different structure, being robust and prehensile with strong short dactyli. The pleon is consolidated into a single segment, which, however, shows traces of its composite nature. It is vaulted above and excavated on *Loud. Mag. Nat. Hist., vol. ix, p. 81, fig. 15, 1836. tAnn. Mag. Nat. Hist., IV, vol. xv, p. 187, 1875., ee ee ee et een oe a uni MARINE ISOPODA OF NEW ENGLAND, ETC. 363 its inferior surface for the delicate pleopods, which are protected by the operculiform uropods. Both rami of the uropods are present in our species, but the outer is much the larger and conceals the delicate inner ramus in’ an exterior view. The outer ramus only is thickened and of functional importance as an operculum. The habits of these animals are described by Goodsir in the Edinburgh New Philosophical Journal, vol. xxxi, p. 311. He says, “With the dredge I have procured specimens * * * * alive, and have kept them in glass jars of sea-water with sand and corallines, and have thus been enabled to watch their habits closely. ‘* Under the circumstances just stated, each individual will select a branch of coralline, will keep that branch exclusively to itself, and will defend it with the greatest vigor against all intruders. It fixes itself to its resting-place by means of its true thoracic feet, and seldom uses these for progression. When it falls to the bottom of the vessel, it fixes its long pointed antenne firmly into the sand, and, with the assistance of the true feet, drags and pushes itself forward. This, however, may not be a natural mode of progression, but may be adopted in consequence of the artificial circumstances in which the animal is placed. “ Swimming is the natural mode of progression. It is amusing to see one of these animals resting, in an erect posture, on a branch of coralline, by means of its true thoracic feet, waving its body backwards and for- wards, throwing about its long inferior antenne, and ever and anon drawing them through its anterior fringed feet, for the purpose of clean- ing them. It frequently darts from its branch, with the rapidity of lightning, to seize with its long antenne some minute crustaceous ani- mal, and returns to its resting-place to devour its prey at pleasure. “In this manner the antenne are the only organs employed in seiz- ing and enclosing the prey, which they drag to the anterior thoracic feet, which hold it while it is being devoured.” Ihave discarded Johnston’s name Leachia, or according to his orthog- raphy Leacia, proposed in 1825, as being preoccupied by Lesueur * in the Molluseain 1821. Astacilla is used by Fleming in the 7th edition of the Encyclopedia Britannica; 1842 is given as the date in the copy of the seventh volume of the Encyclopzedia that I have seen, but Johnston re- fers to Fleming in 1835 as authority for the name, quoting the Encyclo- pedia. Fleming says in the Encyclopedia (vol. vii, p. 502): ‘The ge- nus was instituted by the Rev. Charles Cordiner of Banff in 1784 for the reception of a British species which has been denominated Astacilla lon- gicornis.” Ihave not been able to find whether Cordiner published the name at that early date or whether it was a manuscript name only. If actually published in 1784 it would have many years’ priority over Arcturus, and the author who would unite the genera should use the name Astacilla. Even if not published until 1835 it appears to have the best claim to recognition as the generic name of the type here treated of. * Jour. Acad. Nat. Sci. Phila., vol. ii, p. 89, 1821. 364 REPORT OF COMMISSIONER OF FISH AND FISHERIES. Astacilla granulata Harger (G. O. Sars). Leachia granulata G. O. Sars, Arch. Math. Nat., B. ii, p. 351 [251], 1877. Astacilla Americana Harger, Am. Jour. Sci., III, vol. xv, p. 374, 1878. Astacilla granulata Harger, Proc. U.S. Nat. Mus., 1879, vol. ii, p, 161, 1879 Puates VIII anv IX, FiGs. 48-52. The elongated fourth thoracic segment distinguishes this species at once from all the other Isopoda of our coast. The body is in the female eight times and in the male about twenty times as long as broad, the breadth being measured across the fourth thoracic segment. It is roughened and tuberculated throughout. The head is produced at the sides in front beyond the middle of the basal segment of the antennuls, and is tuberculated above and crossed by two transverse grooves, the first between, and the second behind the eyes, while a third similar groove evidently marks the place of the suture be- tween the head and the first thoracic segment. The eyes are lateral, prominent, round-ovate, broadest in front. The antennulz in the female slightly surpass the second segment of the antenne, in the male they nearly attain the middle of the third segment, the flagellar segment being elongated in the male, longer than the three peduncular segments together (pl. VIII, fig. 48 a). The second and third segments of the antennule are in both sexes short and slender. The antenne are fully three-fourths as long as the body; the first segment is shorter than that of the antennule, being surpassed at the sides by the lateral processes of the head and thus concealed in a lateral view; the second segment is large, scarcely longer than broad, and presents below a deep angular sinus in the distal margin, as in Idotea; third segment about as long as the head; fourth segment longest, slightly exceeding the fifth, which is equal to the first three taken together. The flagellum* (pl. VIII, fig. 49 a) is less than half the length of the last peduncular segment and usually consists of three distinct segments, of which the first is as long as the other two; the second is equal in length to the third, which is tipped with a terminal spine or claw, probably to be regarded as a fourth seg- ment. Sometimes, however, only two distinct segments exist in the flagellum besides the claw. The flagellar segments are finely and sharply denticulate along the margin which is inferior when the an-. tenn are straightened. The character of this denticulation is shown in figure 49 a’ on plate VIII, where a small section of the margin is shown enlarged 100 diameters. The maxillipeds (pl. LX, fig. 52 a) are robust and cover the other parts of the mouth; the external lamella (1) is ovate and in the figure is somewhat bent outward from its natural position. The palpus of the maxillipeds is five-jointed and but little flattened, strongly ciliated along the inner margin. The terminal lobe * The figure of the animal (pl. VIII, fig. 48,) was sent to the engraver before I had seen any specimens except the imperfect ones collected in 1877, and the flagellum of the antennze was dotted from the young specimens. Fig. 49 a@ on plate VIII was made from a specimen obtained in 1878. et ee as oe * he MARINE ISOPODA OF NEW ENGLAND, ETC. 565 (pl. TX, fig. 52 a, m’) is quadrate, scarcely ciliated at the apex, and distinctly articulated with the maxilliped. The outer maxille (pl. LX, fig. 52 b) are three-lobed and strongly ciliated. The inner maxille (pl. LX, fig. 52 ec) are two-lobed, the lobes robust and short, the outer armed with short spines at the apex, the inner with three slender curved sete. The thoracic segments are coarsely granulated or tuberculated; the first is produced at the sides around the head nearly to the eyes; the others have their anterior and posterior margins transverse. The fourth segment in the female is a little less than three times as long as broad, and is longer than the other six segments taken together, but is only four-fifths as long as the last three segments together with the pleon. It is tuberculated, especially above, but bears no prominent tubercles or spines, and is subeylindrical. In the male this segment (pl. VIII, fig. 48 b) is more elongate and much more slender, exceeding in length the three following segments with the pleon. In the ordinary position the thorax is geniculate at the posterior articulation of the fourth segment, forming nearly a right angle with the rest of the body. The last three segments have their epimeral regions angulated and salient. The first pair of legs (pl. VIII, fig. 49 b) are of moderate length and, beyond the basal seg- ment, flattened; the basal segment is directed backward but the leg is bent upon itself at the ischium and the remaining segments are directed forward and applied to the under surface of the head. The ischium and merus support but few cilia,and these mostly along their inner margins, but the carpus, propodus, and dactylus are not only ciliated on the in- ner margin with slender simple cilia, but also bear on the side toward the body stout scattered spinulose setz, which are specially abundant on the propodus. The opposite side of the leg is nearly smooth. The sec- ond, third, and fourth pairs of legs are five-jointed and similar to each other, except that the basal segments of the second and third are some- what shorter than in the fourth (pl. VIII, fig. 50). The second pair is shorter than the third, and the fourth is a little the longest. All these legs are directed strongly forward and habitually held nearly in the position shown in the figure, under the anterior surface of the body and the head. The last three segments are furnished with elongated sete along their inner margins. These sete are inserted in two rows and so placed as to diverge at anopen angle. The dactyli appear to be obsolete in these legs. _ The fifth, sixth, and seventh pairs of legs are of quite a different and more ordinary structure. They contain the full number of segments, and are terminated by robust, slightly curved dactyli. A young specimen obtained has only two pairs of legs of the ordinary form, the last or seventh pair being represented only by rounded tubercles, one on each side of the seventh segment. The pleon is elongate-ovate, narrower in the male (pl. VIII, fig. 48 c). Dorsally it is strongly convex, especially in front. It is two-thirds as long as the fourth thoracic segment in the female, and three-fifths as 866 REPORT OF COMMISSIONER OF FISH AND FISHERIES. long as that segment in the male. It is provided with rather coarse tubercles in front, which are arranged transversely in three rows, and behind the third row is a deep transverse groove, behind which the tu- bercles are less prominent and more of the character of granulations. On each side before the middle is a prominent, sub-acute tooth, directed outward and backward immediately above the articulation of the uropods. The tip of the pleon is not spiniform, but only slightly attenuated and obtuse. The pleopods are delicate in structure, and the anterior pairs are ciliated. The uropods or opercula are more than nine-tenths as long as the under surface of the pleon (pl. VIII, fig. 48 c), but cannot be seen from above. They consist on each side (pl. VIII, fig. 51) of an elongated, semi-oval, basal, lamellar segment, thickened and vaulted externally, with the anterior end rounded, and bearing a salient semi-circular process on the outer margin near the anterior end, for articulation with the pleon. Posteriorly this plate is tapering and it is broadly truncated at the tip, where it bears two lamelliform rami. Of these the external is thick, like the basal segment, and is of an elongate triangular form and com- pletes the operculum behind, while the inner ramus is a small and delicate oval plate, articulated to the basal segment near its inner distal angle, and completely covered and concealed by the outer ramus when the operculum is closed. The inner ramus is sparingly ciliated at the tip. The pleopods are very delicate, and the anterior pairs are ciliated In the females the lamellae forming the ineubatory pouch are thick- ened and tuberculated or granulated along the outer edge where they are attached to the segment. The thickened area is bounded by a lon- gitudinal ridge, beyond which the lamella is thin, smooth, and translu- cent, permitting the eggs to be seen through it, and the thin portion of the right lamella (in the specimen examined) overlaps its fellow of the opposite side so far as to bring its edge along the base of the ridge bound- ing the thickened portion of the opposite lamella. Near the anterior end and on the outer side is a rounded lobe in the margin of the lamella for articulation with the segment. fb Length of female 10™"; male 11™; diameter of fourth thoracic seg- ment, female 1.2"; male 0.52""; color in alcohol, nearly white. This species was described by the writer without having seen Sars’ description of Leachia granulata. The volume containing his description has since been obtained by the Yale College Library, and a careful com- parison of our specimens with his description leaves little doubt that the species is identical with his. His specimens were somewhat larger than ours, females measuring 14" and males 17". The females in A. longi- cornis Sowerby are much larger than the males, and the reverse rela- tion of size in this species appears to be unusui! in the genus. Specimens were first collected on this coast on Ceorge’s Bank !, in the summer of 1877, and the three then obtained were found adhering to Primnoa, and had been dried and somewhat broken. Better specimens were collected adhering to the cable of the schooner ‘Marion,’ at Ban- : ; ‘ f 0 emt Mas ball ete aor i a Se Ae MARINE ISOPODA OF NEW ENGLAND, ETC. 367 quereau!, by Capt. J. W. Collins, August 25, 1878, and a fine specimen was obtained in seven fathoms off Miquelon Island!, south of Newfound- land, by Capt. C. D. Murphy and crew of the schooner ‘Alice M. Will- iams,’ July 3,1879. Sars’ specimens were collected between Norway and Iceland at stations 18 and 48, of which the respective localities as given by him are latitude 62° 44.5’ north, longitude 1° 48’ east, in 412 fathoms, clayey bottom, and latitude 64° 36/ north, longitude 10° 21.5’ west, in 299 fathoms, clay and sand. Specimens examined. i Q | Specimens. Ee Locality. = Bottom. Wen sor Received from— == eke 2 é | No. | Sex. 2045 | George's Bank......|......-.|...-...0200---- ——~—, 1877 | U.S8.FishCom.| 2/9 y/ Ale. TSS CIDE EES RO | | eee oe — —, 1877 | ...do......... 1 3 | Alo. Banquereau, N. S..-| 250 | Rocky .--..... —— —, 1878 ore: J. W. Col- 3 Q | Alo. ins. Off Miquelon Island.| 7 |.........-...... July 3, 1879 | Capt.C.D.Mur- 1 Q | Alc. phy and crew. VIIL—SPH A ROMID A. Body short and convex; head transverse; antennule and antenns multiarticulate, with evident distinction into peduncle and flagellum; mandibles palpigerous; epimera united with the thoracic segments; anterior segments of the pleon short, united and articulated with the large terminal segment; uropods lateral with only one movable ramus. This family is sparingly represented on the eastern coast of the United States, and within our limits only a single species is found, belonging to the typical genus Sphewroma. The animals are usually of small size, and have the body short, broad, and convex. The head is transverse, and both pairs of antenne are inserted near together below its anterior margin. These organs are much better developed than in the following family. The epimera are faintly indicated in the thoracie segments by impressed lines. The anterior segment of the pleon is sim- ilarly marked with transverse sutures indicating the segments of which itis composed. The last segment is large, and one or more of the pos- terior segments may be notched, tuberculated, spiny, or variously modi- fied, as occursin many foreign genera. Below, the pleon is much exca- vated for the pleopods, which, as usual, are in five pairs, the anterior three ciliated. In the males aslender stylet is articulated near the base of the inner lamella of the second pair, and lies along its inner side, so that in the natural position they lie close together on opposite sides of the middle line of the body. These pleopods, though received into a cavity in the under surface of the pleon, are not protected by any oper- culum nor opercular plates, as in most of the preceding families, nor is the external pair thickened, as in the Anthuride. | 368 REPORT OF COMMISSIONER OF FISH AND FISHERIES. Sphzroma Latreille. Spheroma Latreille, Hist. nat. des Crust. et des Ins., tome vii, p. 11, 1804. Body contractile into a sphere; antennule and antenne short or of moderate length; maxillipeds with a five-jointed palpus; legs all ambu- latory; dactyli short and thick; uropods short, ramus and basal seg- ment subequal. The name of this genus is derived from the peculiar habit of many of the species of rolling themselves into a ball when alarmed. The body is so constructed as to facilitate this operation, the antennule and antennz being received into a groove at the side of the head; the epi- meral regions of the thoracic segments behind the first are narrowed nearly to a point and project well downward so as to meet very close together and still leave room for the included legs, while the uropods, shutting together like a pair of scissors, fold also partly under the large terminal segment of the pleon and fill the crevice between the pleon and the head. The maxillipeds:in this genus are provided with a long densely ciliated five-jointed palpus. The maxille are much as in the Idoteide, the outer pair three-lobed and strongly ciliated, the inner two-lobed with the inner lobe small and tipped with pectinate sete, the outer larger and armed with curved denticulated spines. The mandibles have a strong molar process, a dentigerous lamella armed with acute teeth, and a three-jointed palpus. The legs are rather weak and nearly alike throughout, all ambulatory. The pleon is searcely narrower than the segments of the thorax and ap- pears to consist of two* segments only, of which the first is much like the last thoracic segment, but more strongly produced at the sides than is that segment and marked with impressed lines. It is articulated with considerable motion to the large scutiform terminal segment, which, in this genus, is rounded and entire at the tip, and not strongly tubereu- lated nor spiny. Anteriorly, the angles of this segment are produced downward into a rounded lobe in front of the shoulder from which arise the uropods. These organs are not greatly elongated; the basal seg- ment is produced into a plate about equal in size to the single ramus. Sphezroma quadridentatum Say. Spheroma quadridentata Say, Jour. Acad. Nat. Sci. Phil., vol. i, p. 400, 1818. Dekay, Zool. New York, Crust., p. 44, 1844. White, List Crust. Brit. Mus., p. 102, 1847. Harger, Am. Jour. Sci., III, v., p. 314, 1873; This Report, part i, p. 569 (275), pl. v., fig. 21, 1874; Proc. U.S. Nat. Museum, 1879, vol. ii, p. 161, 1879. Verrill, This Report, part i, p. 315 (21), 1874. PLATE IX, Fra. 53. The outline of the body when extended is a pretty regular ellipse, but the animal, when disturbed, rolls itself into a ball with facility, and by * The pleon is inadvertently described by Bate and Westwood in the British Sessile- Bead Crnctarean val iit n ANT. as ‘Shavine all the seoments fused tocether.” ee eS eee MARINE ISOPODA OF NEW ENGLAND, ETC. 369 this habit may be distinguished from the other marine Isopods of our coast. The head is rounded in front with an elevated margin, and a slight me- dian projection between the bases of the antennule. The eyes are small and sub-triangular, widely separated. The antennule and the antenn are inserted on the inferior surface of the head, and, when the animal contracts, they are received into a groove along the margin of the head and anterior thoracic segment. The antennulee (pl. LX, fig. 54a) have the basal segment large, the second segment small and conical, the third slender, cylindrical; the flagellum about ten-jointed, ciliated, shorter than the peduncle. In the antenne (pl. IX, fig. 545) the peduncu- lar segments decrease but little in diameter, and increase in length from the first to the fifth, and are followed by a flagellum about as long as the peduncle, tapering from the base, with the basal segments strongly ciliated along their inner or anterior distal margins. The antenne are separated at the base by a triangular, somewhat projecting epistome, which also partly separates the bases of the antennule. The maxilli- peds have the basal segment short and somewhat triangular, with plu- mose sete at the acute apex, and a five-jointed palpus, of which the first segment is short and smooth, and the following segments strongly ciliated along more or less of their innermargins. The outer maxille are termi- nated by three ovate rather acute lobes, which are strongly ciliated. The inner maxille have the inner lobe tipped with four pectinated curved sete, and the outer armed with strong denticulated spines. The mand- _ibles are robust and bear on their external surface at the apex a dentig- erous lamella, or usually two such on the right mandible, receiving the lamella of the left between them; below the lamella is a strongly ciliated ridge supporting the dentigerous lamella and connecting it with the mo- lar process, which is large and strong. The mandibular palpi are slender, with the last segment sub-semicircular, bearing at its apex a few serrated spines, and below a comb of straight sets; the middle segment bears a similar comb with stouter spiny setz at the ends. The first thoracic segment is longer than the others, and much elon- gated at the sides,embracing the head as far as its anterior margin. Above this lateral expansion on each side the segment is excavated for a projecting lobe of the head behind the eye. The second, third, and fourth segments are somewhat shorter than the first and longer than the fifth, sixth, and seventh. The margin of the last segment bends slightly backward at the middle. In the thoracic segments behind the first the epimeral sutures are indicated by a faint depressed line, below which the lateral margin of the second segment tapers to an obtusely rounded point, the third is more acutely pointed, the fourth oblique and acute behind, the fifth and sixth also oblique but less acute, and the seventh rounded. The legs are weak, hairy, and much alike throughout, formed for walking, and none of them chelate. The dactylus in all is short and robust, armed with a stout curved spine or claw at the tip, and a smaller (24 F 370 REPORT OF COMMISSIONER OF FISH AND FISHERIES. ' straight spine below it. In the first pair of legs the carpus is short and triangular, the ischium and merus bear on their upper margin a row of long slender plumose hairs. In the second and third pairs of legs these hairs are also found, and the carpus is longer. The fourth pair of legs are robust, the following pairs more slender to the seventh. All are well provided with slender hairs, with a few stouter ones intermixed. The anterior segments of the pleon are consolidated into a single piece somewhat resembling the last thoracic segment, but marked at the sides by depressed lines, indicating sutures, as shown in pl. IX, fig. 53. At the sides this segment is broadly rounded and projects much below the seventh thoracic when the animal is contracted. The large terminal segment has a similar lobe in front of the bases of the uropods. At the insertion of the uropods the segment is considerably contracted laterally, but is rounded and strongly margined behind. Its anterior lobe, all the thoracic segments, and the head are also margined by an elevation run- ning completely around the animal except where it is interrupted by the uropods. The uropods extend nearly to the tip of the telson, and consist on each side of a basal segment continued backward into a nar- row oval plate with entire margins, flattened below, where a similarly- shaped ramus is articulated near its base, the two shutting together like the blades of a pair of scissors. The articulated plate bears four more or less acute serrations on its exterior margin, whence the specific name. The pleopods are ciliated, and the second pair (pl. IX, fig. 54¢) bears, in the male, on the inner lamella, a slender curved stylet, longer than the lamella, and articulated near its base. Length about 8"™", breadth 4"". The color, as usual in shore species, is variable; some are of a uniform slaty gray, many are marked on the dorsal surface with a whitish, cream color, or rosaceous patch, bordered more or less with dark or black. This patch has commonly a longitud- inal direction, and is usually symmetrical, and may be broad or much narrowed in the middle. On the dark or barnacle-covered rocks, where these animals are often found, the colors are evidently protective, but they are imperfectly preserved in alcohol. This species was described by Say, who “found these animals very numerous on the beach of Saint Catherine’s Island, Georgia, concealing themselves under the raised bark, and in the deserted holes of the Teredo, &c., of such dead trees as are periodically immersed.” He also gives East Florida as a locality, and there are specimens in the Yale Museum from Florida! It extends as far north as Provincetown, Mass.! near the extremity of Cape Cod. It is common on the southern shore of New England!, and is usually found among algz or rocks. MARINE ISOPODA OF NEW ENGLAND, ETC. 371 Specimens examined. ; s a 3 E When col $8 |p ‘ ts) - P » E Locality. 4 Bottom aah ae Received from— 28 rte S A cy my o SM UBTUENIEE Oat tits Steet eh cain al okt Gee cen ime swacine se belleup sce ena'cmi'sis Smithsonian Inst. canbe 0 | Ale. feet: | Great Kee Harbor, N. J. 2). 2.2.20). 2.sceseenescess April, 1871 Smith & Verrill siueea Alc. Ee PN awn av ens CON. ose ce sae sinae veneer cnmmeane ams|<9 2-0 serinnseme 8. I. Smith. - 5 Ale. avin hook, New Haven...) i. w. | Rocky 2.22.6) 0c- oo elec canteen cen ne 00 Ale. 2052 | Stony Creek, Cannes ee--<- 1b AEC? Sac eneee AER eeee Seereee enrar - laser = aes 00 | Ale. 2049 Wie ard Suand, Masa 2:..|.0265..-}.cces~cc-- sees — —, 1871 | U. 2 oe Com.| 3 | Alc. PERM Jew atidananeis maaaiss 1 ey Sa ce Gar Sane ae —— —, 1871 |...-do ......... Zi: Ale. SOM EPEP OR ae ae Seen conse atom en loan ea~ aansin nes —— —, 1875 vice dedaedees 5 | Ale. Provincetown, Mass ...... as Wr rete ale ciasd inte aa Aug.—, 1879 |....do ......... 00 | Ale. Shc ditt (3A EE RS Ee 4 Eel-grass......| Aug.—, 1879 |-...do .-......- 1 Ale. VIII.—LIMNORIID Ah. Body compressed; antennulz and antenne short, subequal; mandi- bles palpigerous, formed for gnawing; feet not prehensile, all similar, with short, robust dactyli; epimera united with the thoracic segments ; pleon of six distinct segments; pleopods similar in form throughout; uropods lateral, biramous. This family as constituted above contains the single genus Limnoria Leach, which appears also to contain but few, or perhaps a single, species* of wide distribution. This genus was placed in the tribe Asellotes homopodes with the Asellide by Edwards, without, however, having examined the animals himself. He has been generally followed in this arrangement by later authors. Previous authors had associated the genus, as it appears to me more justly, with Sphwroma and the Cymo- thoide in the wide signification of the latter term. White, in his List of British Crustacea, used the name Limnoriade to include this genus with the Asellide. I have preferred to constitute a new family for the genus, which has, however, evident relations with the Spheromide, and perhaps should yet be united with that family. Under the circumstances family characters can scarcely be separated with certainty from those of generic or even of specific value only, but for the purpose of comparison with other families certain important char- acters may be here stated. The body is somewhat depressed dorsally, but is also compressed at the sides, and when extended is subvermiform. It is nearly capable of being rolled into a ball, as in the genus Spheroma. The head is of moderate size and strongly rounded above, as in Sphe- roma, and the eyes are widely separated and on the sides of the head, a condition not usual in the Asellide. The antennule are short and stout and the basal segment is but little larger than the second; the flagellum *Tt is perhaps hardly necessary to remark that L. xylophaga Hesse, Ann. Sci. nat., tome x, p. 101, pl. ix, 1868, is not an Isopod. According to Prof, Smith it is Chelura terebrans Phillipi, a boring amphipod often found associated with Limnoria. See an article by that author in the Proceedings of the U. S. National Museum, 1879, vol. ii, pp. 232-235. 372 REPORT OF COMMISSIONER OF FISH AND FISHERIES. consists of a single, almost rudimentary segment. The antenne differ widely from any in the Asellide, since they are less robust than the anten- nul, and but little longer; the peduncular segments are all short, having almost the same proportion to each other as in Spheroma (see pl. TX, figs. 54b and 565), the last two being together about equal in length to the first three, instead of far surpassing them as in the Asellide; the flagel- lum is short and few-jointed, mostly made up of a tapering basal seg- ment, and not at all resembling the slender multiarticulate flagellum of the Asellide. The mandibles are adaptively modified in accordance with the boring habits of the species, but the other mouth parts do not seem to present characters from which comparisons need be drawn with other families. The legs are somewhat similar to those seen in many Asellide, being © furnished with short dactyli, each armed with a strong curved claw, and a Shorter spine below. A similar form of leg is, however, seen in Sphe- roma. ‘The epimera are united to the lateral margins of the thoracic segments almost precisely as in Spheroma, an arrangement that does not prevail in the Asellide. The pleon has all its six segments well developed and perfectly separated from each other, while in the Asellide they are united into a single scuti- form segment, or at most, the basal segment only is more or less distinct. The pleopods are of the normal number and similar in form and texture throughout; the anterior pairs are ciliated. Each pair of pleopods consists of a basal segment, bearing an inner narrow lamella and an outer oval one, which, except in the fifth pair, are well ciliated. In the male the inner la- mellaof the second pair bears, on its inner margin, astylet, as in Spheroma and many other genera of Isopoda. In the Asellide the branchial pleo- pods are in fewer than five pairs, and are protected in front by a simple or compound operculum of firmer texture than the other pleopods. Dr. Coldstream * fell into an error in describing the respiratory organs as con- sisting of “six pairs of scale-like bodies, pendant from the anterior seg- ments of the tail, * * arranged in three rows, in an imbricated man- ner, one of each kind (‘oval’ and ‘nearly quadrangular’) being articu- lated together on a common peduncle on either side.” He further describes, loc. cit., p. 324, ‘ two vesicular bodies of an oval form” behind the branchiz. These organs were without doubt the external lamelle of the fifth pair of pleopods, as shown by his figure. There are, how- ever, four instead of three ciliated pairs anterior to the last pair, one of which was overlooked by Dr. Coldstream, and in this error he has been followed by Bate and Westwood.t If the observations of Dr. Cold- stream had been correct, an affinity might have been indicated with the Asellide. The terminal segment is flattened and scutiform, in shape resembling that of Jwra, but the uropods are strictly lateral, being attached at the broadest part of the segment and in front of the middle. * Edinburgh New Phil. Journal, vol. xvi, p. 323. t Brit. Sessile-Eyed Crustacea, vol. ii, p. 350. MARINE ISOPODA OF NEW ENGLAND, ETC. 373 The relations of the present family with the Sphaeromide appear to be more close, but the structure of the mandibles and perhaps also that of the maxillipeds, the fully segmented pleon and the biramous uropods seem to be characters of family value, which, however, a fuller investi- gation of the boring Spheromide might go far to break down. Limnoria Leach. Limnoria Leach, Edinburgh Encye., vol. vii, p. 433” (Am. ed., p. 273), 1813-14.” Mandibles with a nearly even chisel-like cutting-edge at the tip and no molar process; maxillipeds elongate, with a well-developed external lamella and a five-jointed palpus; first thoracic segment large; uropods with the outer ramus very short and almost obsolete. genus from Cymothoa and the Spheromide, with which he associated it. Limunoria lignorum White (Rathke). ““Cymothoa lignorum Rathke, Skrivt. af Naturh. Selsk., v. 101, t. 3, f. 14, 1799” (White). Limnoria terebrans Leach, Ed. Encye., vol. vii, p. ‘433’ (Am. ed., p. 273), “¢1813-14”; Trans. Linn. Soe., vol. xi, p. 371, 1815; Dict. Sci. nat., tome xii, p. 353, 1818. Samouelle, Ent. Comp., p. 109, 1819. q Desmarest, Consid. Crust., p. 312, 1825. Latreille, Regne Anim., tome iv, p. 135, 1829. ; if ; The above characters differ from those by which Leach separated this > q Coldstream, Edinb. New Phil. Jour., vol. xvi, pp. 316-334, pl. vi, 1834. ‘Hope, Trans. Ent. Soc. Lond., vol. i, p. 119” (B. & W.). ; Thompson, Edinb. New Phil. Jour., vol. xviii, p. 127, 1835; Ann. Mag. Nat. Hist., vol. xx, p. 157, 1847. 1 Templeton, Loud. Mag. Nat. Hist., vol. ix, p. 12, 1836. ; Moore, Charlesworth’s Mag. Nat. Hist., n. s., vol. ii, p. 206, 1838; ibid., vol. iii, pp. 196, 293, 1839. Edwards, Annot de Lamarck, tom. v, p. 276, 1858; Hist. nat. des Crust., tom. iii, p. 145, 1840; Régne Anim. Crust., p. 197, pl. 67, f. 5, 1849. 1 Gould, Invert. Mass., pp. 338, 354, figure, 1840. | Fleming, Encye. Brit., 7 ed., vol. vii, p. 502, 1842. : Dekay, Zool. New York, Crust., p. 48, pl. ix, fig. 33, 1844. $ ‘Kirby and Spence, Int. Entom., 5th ed., p. 238; 6th ed., p. 203” (White.) | White, List Crust. Brit. Mus., p. 96, 1847; Brit. Crust. B. Mus., p. 68, 1850. Dalyell, Powers of the Creator, vol. i, p. 241, pl. Ixv, figs. 7-15, 1851. 7 Leidy, Jour. Acad. Nat. Sci. Phil., II, vol. iii, p. 150, 1855 | Gosse, Man. Mar. Zool., vol. i, p. 136, fig. 242, 1855. Steenstrup and Liitken, Vidensk. Meddel., II, vol. ii, p. 275, 1861. Hesse, Ann. Sci. nat., Zool., V, tome x, p. 113, 1868. Jones, Trans. Nova Scotian Inst. Nat. Sci., vol. ii, pt. iv, p. 99, 1870. Verrill, Proc. Am. Assoc., 1873, p. 367, 1874. Macdonald, Trans. Linn. Soc., II, Zool., vol. i, p. 67, 1875. Andrews, Q. Jour. Mic. Sci., I, vol. xv, p. 332, 1875. Timnoria lignorum White, Pop. Hist. Brit. Crust., p. the pl. 12, fig. 5, 1857. Bate, Rep. Brit. Assoc., 1860, p. 225, 1861. Bate and Westwood, Brit. Sess. Crust., vol. ii, p. 351, figure, 1868. 374 REPORT OF COMMISSIONER OF FISH AND FISHERIES. Limnoria lignorum—Continued. Norman, Rep. Brit. Assoc., 1868, p. 288, 1869. Mobius, Wirbellos. Thiere der Ostsee, p. 122, 1873. Parfitt, Fauna of Devon, Sess. Crust., p. (19), 1873. Verrill, Am. Jour. Sci., III, vol. vii, pp. 133, 185, 1874; Proc. Am. Assoc., 1873, p. 371, 1874; This Report, part i, p. 379 (85), 1874. Harger, This Report, part i, p. 571 (277), pl. vi, fig. 25, 1874; Proc. U. S. Nat. Mus., 1879, vol. ii, p. 161, 1879. M’Intosh, Ann. Mag. Nat. Hist., IV, vol. xiv, p. 273, 1874. Stebbing, Trans. Devon. Assoc., 1874, p. (8), 1874. Ann. Mag. Nat. Hist., IV, vol. xvii, p. 79, 1876. Whiteaves, Further Deep-Sea Dredging, Gulf St. Lawrence, p. 15, 1874,” Metzger, Nordseefahrt der Pomm.., p. 285, 1875. Meinert, Crust. Isop. Amph. Dec. Dani, p. 77, 1877. Smith, Proc. U. 8. Nat. Mus., 1879, vol. ii, p. 232, fig. 2, 1880. Timnoria uncinata Heller, Verh. k. k. Zool. bot. Ges. Wien, B. xvi, p. 734, 1866. Stalio, Cat. Crost. Adriatic, p. 211, 1877. PLATE IX, Frias. 55-57. This species may in general be recognized by its habits, being usually found burrowing in submerged timber, to which, notwithstanding its insignificant appearance, it often proves very destructive. The body is subeylindrical, tapering slightly at each end and covered above with short hairs to which more or less dirt usually adheres. The head is narrower than the first thoracic segment. The eyes are lateral and consist of about eight ocelli, one central and the others around it. The antennule (pl. IX, fig. 56 a) are short and seem to arise from near the middle of the front of the head. The basal segment is the largest; the see- ond and third are of slightly decreasing size; the fourth or flagellar seg- ment is, much the smallest, and tipped with sete. The antennze (pl. IX, fig. 56 b) are more slender than the antennule, and arise just below their bases and a little farther apart. The first two segments are short; the third slightly longer; the fourth and fifth increasing somewhat in length; the flagellum is not longer than the last two peduncular segments, and consists of a tapering segment, followed by a few short terminal seg- ments provided with a terminal brush of sets. The maxillipeds (pl. LX, fig. 56 c) are slender; the external lamella is semi-ovate, with the inner margin nearly straight, acute, and ciliated at the tip; the palpus is five-jointed but short, with the segments flattened, and all but the first ciliated along their inner margins. The outer maxille (pl. LX, fig. 56 d) are slender, three-lobed, and ciliated at the tip. The inner maxille (pl. IX, fig. 56 e) are also slender, the inner lobe tipped with pectinate bristles, the outer with robust spines. The mandibles (pl. LX, fig. 56,7) are some- what elongate, but of a simple form, being curved inward, flattened and chisel-shaped at the tip; below there is a slight tubercle, apparently the rudiment of the molar process; externally, above the origin of the palpus, is a prominent tubercle ; the palpus is short, of three subequal segments, the last furnished with a rather imperfect comb of setz. The first thoracic segment is about twice as long as any that follow; itis crossed by a broad, shallow depression, and is rounded at the sides. , MARINE ISOPODA OF NEW ENGLAND, ETC. 375 The second and third segments are each about half the length of the first. The epimeral sutures are evident, and the epimera are rounded behind in the second segment, but a little more prominent in the third, becoming acute and increasing in size and extension backward to the seventh. The fourth segment is slightly shorter than the third, and per- haps a little broader; the last three are short, decreasing in length to the seventh, but maintaining about equal width. The legs are short and rather robust. The first pair have the carpus triangular, but this seg- ment becomes more elongate in the succeeding pairs. The dactyli are robust, and are armed with a strong curved spine or claw at the tip and a smaller one below it. The merus, and usually the ischium and carpus, bear a few spiniform tubercles on the lower surface except in the last pair, which are also more elongated and slender than the others. The pleon is scarcely narrower than the thorax, and tapers but little; the first four segments are of equal length; the fifth is longer with a median elevation and a transverse depression on each side. The last segment (pl. LX, fig.57a)is transversely oval or subcircular, broader than long, with the anterior margin raised, especially at the middle, where the elevation is continued a short distance on the segment, but posteriorly it is flattened. The posterior margin is ciliate with hairs of various lengths. The uropods (pl. [X, fig. 57b) are attached just in front of the middle of the segment at its widest part. They consist on each side of a somewhat wedge-shaped basal segment, ciliated and bluntly denticu- lated distally on the outer side, and supporting two rami, between which it is produced below into a strong tooth-like process. The outer ramus is very short and curved outward; the inner is not asiong as the basal seg- ment, and is ciliated externally and at the tip. Underneath, the pleon is much excavated for the pleopods, which are strongly ciliated. The first pair (pl. LX, fig. 57¢) consist on each side of a short basal segment bear- ing two lamelle; the inner lamella is almost four times as long as broad, with nearly parallel sides, ciliated at and near the tip; the outer, which is also in front of the inner, is sub-oval with the outer margin more convex than the inner, ciliated near the tip and along most of the outer margin, and inserted a little obliquely upon the basal segment. The next three pairs of pleopods are similar to the first pair on each side, except that in the males the second pair (pl. IX, fig. 57 d) bears a stylet (s) articulated to the inner margin of the inner lamella about the middle. The posterior pair of pleopods are smaller than the others and not ciliated. Length 4.5™"; breadth 1.5"; color light grayish. Much has been written upon the destructive habits of the Limnoria or “sribble” and the means of preventing its attacks on woodwork, for which the reader may consult especially the publications of Leach, Cold- stream, Hope, Thompson, Moore, Gould, Bate and Westwood, Verrill, and Andrews, who has observed it attacking the gutta-percha of submarine telegraph cables. 376 REPORT OF COMMISSIONER OF FISH AND FISHERIES. It is found boring in submerged wood along our coast from Florida! to Halifax!, N. S., and the Gulf of St. Lawrence. It occurs above low- water mark, but does not usually live far below that line; it has, however, been found by Professor Verrill at a depth of 10 fathoms in Casco Bay, and was dredged by the U.S. Fish Commission in a depth of 74 fathoms, Cape Cod Bay!, Mass., in the summer of 1879. It is abundant, according to European authors, in many localities on the coast of Great Britain and in the North Sea. ZL. wneinata Heller, from Verbosca, in the Island of Lesina, Adriatic Sea, appears to be the same species, as the differences pointed out by Heller do not really exist, but were doubtless suggested by the incorrect figures that have been published representing the uro- pods with rami composed of two or more segments. The form of these appendages, as shown on plate IX, fig. 57 b, corresponds well with Hel- ler’s description. It was found by Heller associated with Chelura tere- brans. Limnoria is said also to occur in the Pacific Ocean, and from its habits might be expected to have a wide distribution. Specimens examined. ‘sa J Bg E Locality. Habitat. pene Received from— ae rc A a 20480 |UMlorida)és-c-sse-=--es% = Boring in wood....|.--..----.-.- | Smithsonian Inst .- 6 Alc. Provincetown, Mass...-. ee nOO tec sc a meeenee Aug., 1879|U.S.FishCom..-.| 00 Alc. 2047 | Casco Bay .-..--1-...---: Scot daneaboocace — —, 1873 |....do ...........-- 30 Alc. Bay of Fundy ..--.- bestia [econ Owie a.nisaeicie eer — —, 1872 |...-do ......-.....- 00 Ale. Alibi tiN, 845.1 occ sce eetido 2st tietemees —— —, 1877 |....do ........-..-- 00 | Ale. IX.—CIROLANID 4. Front formed of the approximate basal segments of the antennule, which are not covered by an anterior projection of the head; antennulze and antennze presenting an evident distinction into peduncular and flagellar segments; maxillipeds with a five-jointed palpus; mandibles formed for biting, palpigerous; legs all terminated by nearly straight dactyli; epimera distinct behind the first thoracic segment; pleopods at least the anterior pairs, ciliated; uropods biramous, the rami flattened and ciliated. This family is represented on our coast by two closely allied species apparently belonging to the typical genus Cirolana, although approach- ing the allied genus Conilera, to which I formerly referred them. They have been hitherto usually referred to the following family, but the dif- ferences in the structure of the mouth parts, first pointed out by Schiddte, seem to warrant their separation as a distinct family. The mandibles are formed for biting, being armed with long and powerful teeth, which, closing together like the blades of scissors, are well adapted for lacerat- ing the flesh of fishes on which they feed. The first three pairs of legs are fitted for prehension, but they are destitute of the strongly curved MARINE ISOPODA OF NEW ENGLAND, ETC. 377 dactyli found in the Wgide, and still better developed in the Cymothoide, In the Cirolanide the propodus, in the first three pairs of legs, is some- what curved and the dactyli are nearly straight, so that while the first three pairs of legs are powerful organs of prehension, they are also eapable of letting go preparatory to the seizure of another victim. The posterior pairs of legs are ambulatory or fitted for swimming by their form and armature of bristly hairs. The ciliated pleopods are also powerful swimming organs, so that these animals are well fitted for the predatory life they lead. The epimera are well separated by sutures in all the thoracic segments behind the first. The pleon is scarcely nar- rower at base than the last thoracic segment, and is composed of six distinct segments, of which the last is much the longest, but not broader than the preceding segments, and tapers posteriorly. ‘The uropods are lateral, articulated near the base of the last segment and distinctly biramous. The mouth-organs of this and the two following families have been the object of special research by J. C. Schiddte, whose papers in the Natur- historisk Tidsskrift have been in part translated in the Annals and Magazine of Natural History. He regards Cirolana as representing “ the highest development of the crustacean type among the Isopoda,” and even hints that Cirolana and A?ga should be removed to opposite ends of the series of Isopoda. The same author would closely unite the Bopy- ride, Aiga, and the Cymothoide into a single group, the Cymothoe, while acknowledging that the young of Cymothoa estrum, “ according to the classification hitherto current, * * * would rather be allied to Cirolana than to Cymothoa.” His classification, however, appears to be based almost entirely upon the structure of the mouth, disregard- ing the totality of structure upon which alone morphological classi- fication can securely rest. In deference, however, to his views I have here regarded Cirolana as the type of a distinct family, which must still be considered as closely related with the two following families, on the principle that it is ‘more important that similarities should not be neg- lected than that differences should be overlooked.” Among the more important of the similarities by which these fami- lies seem to be united may be mentioned the following, as exemplified by our species. The segments of the thorax and pleon are all distinct from each other, so that the body, in the adults, appears to consist of thirteen segments behind the head, although in the genus Ourozeuktes Edwards* the segments of the pleon are consolidated. The epimera are distinct in all the segments behind the first thoravic. The pleon may or may not taper from the base, but it is terminated by a large scutiform segment, sometimes more or less sculptured, and bearing at the sides, near the base, a pair of uropods, in which the basal segment is more or less oblique distally and the rami lamelliform, though one of them may be narrowly so. The pleopods are unprotected by any form * Hist. nat. des Crust., tome iii, p. 275, 1840. 378 REPORT OF COMMISSIONER OF FISH AND FISHERIES. of operculum and the anterior pairs are ciliated in the young of all three families, but this ciliation, as well as that on the uropods, may be lost in the sedentary adults of the Cymothoide. In all our species the dorsal surface is smooth throughout, or minutely punctate under a lens, but destitute of distinct roughness, tuberculation or sculpture, except that the telson may be faintly grooved or sculptured, and in some foreign species more distinctly so. Cirolana Leach. Cirolana Leach, Dict. des Sci. nat., tome xii, p. 347, 1818. Thoracic segments subequal; eyes small, well separated; mandibles armed with strong acute teeth; dactyli straight, or but slightly curved; pleon of six distinct segments; basal segment of uropods with the inner angle produced. Two closely allied species are found on this coast, which I formerly referred to the genus Conilera Leach. Further consideration induces me to refer them rather to the present genus, although they have some features which point toward Conilera, and are perhaps between that genus and the typical forms of Cirolana.. From Conilera, as described by Bate and Westwood, our species differ principally in the more robust four posterior pairs of legs, in the produced angle of the basal segment of the uropods, and in the structure of the first pair of pleopods, which are not operculiform either in size or texture. Of these two species one is abundant and is described at length. The description will, however, apply almost equally well to the other except in the few points mentioned in the appropriate place. The characters given, though slight, appear to be constant, and I have therefore retained the two specific names. This genus differs from_dZga in the structure of the legs, and was placed by Professor Dana in a separate subfamily. In Cirolana the first three pairs of legs are strong, and armed with minute spine-like claws at the tip of the nearly straight dactyli; the propodi in these legs are robust, spiny, and somewhat curved, and some of the preceding segments are also armed with spines. These legs thus form powerful organs for seiz- ing living prey, and are not, as in the Cymothoide, and, in a less degree, in Aga, merely fitted by their curved dactyli to retain the hold of the animal upon its host in a parasitic existence. The last four pairs of legs are well ciliated and capable of use either for walking or swim- ming, and these animals are thus fitted for their active and predaceous life. Cirolana concharum Harger (Stimpson). Aga concharum Stimpson, Mar. Inv. G. Manan, p. 42, 1853. Liitken, Vidensk. Meddel., 1859, p. 77, 1860. Conilera concharum Harger, This Report, part i, p. 572 (278), 1874. Verrill, This Report, part i, p. 459 (165), 1874. Cirolana concharum Harger, Proc. U.S. Nat. Mus., 1879, vol. ii, p. 161, 1879. - — MARINE ISOPODA OF NEW ENGLAND, ETC. 379 PLATES IX AND X, F1as. 58-63. This species may be most readily recognized among our Isopoda by the distinct thoracic and abdominal segments, the small lateral eyes, and the evident distinction, in both antennule and antenne, of pedun- ele and flagellum. From the next species it is distinguished by the tip of the telson, which is truncated, or slighty emarginate, and grooved on the median line above near the end. The body is, when extended, about three times as long as broad, and is smooth and polished throughout. The head is quadrate, a little broader in front than behind, and embraced at the sides by the first thoracic segment. The eyes are triangular, with the angles rounded, and are often partially covered below by the projecting anterior lobes of the first thoracic segment. They are separated by about three times their long- est diameter. The antennule (pl. X, fig. 60) are robust, with their basal segments in contact; the first segment is short and sub-spherical ; the second also short; the third cylindrical and as long as the first two taken together and followed by a robust, but short, tapering flagellum, © consisting of about fifteen segments, of which the second is as long as any other two, but the rest are all short. The flagellar segments beyond the first are provided each with a tuft of “ olfactory sete.” The antenns (pl. X, fig. 61a) are longer and more slender than the antennule, and are separated at their bases. The first four peduncular segments are robust; the first two short; the third and fourth each about twice as long as the first or second, and the fifth or last peduncular segment slightly the longest and much the most slender. The fourth and fifth ‘ segments bear along the distal portion of their outer margins long | ee tee) bristle-form hairs. The flagellum is slender and composed of from 15 to 18 segments, each bearing a few short bristles. The maxillipeds (pl. X, fig. 62a) are elongated and almost pediform but flattened; the external lamella is small and subtriangular, rounded and hairy at the tip; the palpus is five-jointed, with the last four segments broad, flattened, and well ciliated; the tip of the maxilliped, nearly concealed by the large palpus, is provided with very densely plumose bristles. The outer maxill (pl. X, fig. 61b) are short and robust; the two articu- lated lobes narrow ovate, rounded at the tip, armed, especially the inner one, with spines and plumose or pectinated bristles. The inner maxille (pl. X, fig. 61 ¢) are robust, with the outer lobe armed with strong smooth spines; the inner lobe rounded at the end and bearing three straight rather blunt spines, densely covered toward the tip with soft hairs. The mandibles (pl. X, figs. 61 d) are robust and horny at the tip, armed with one strong acute tooth, and in the right mandible with one acute and one obtuse tooth along a cutting edge, while the left mandible has three less acute teeth along this edge. Each mandible is, moreover, provided with a molar process or area (m), on its inner surface set along its interior and upper margin with spines. A narrowly lanceolate leaf- like appendage is attached just below the molar area. This appendage 4 380 REPORT OF COMMISSIONER OF FISH AND FISHERIES. ‘is furnished with a few bristles near the base, and its upper edge is armed with minute denticles; it is movable and ordinarily concealed behind the mandible. On the external surface, just above the origin of the palpus, each mandible bears two elevated, conical, obtuse tuber- cles. The palpi are slender, the second segment longest and hairy on the margin beyond the middle, the last segment slender and curved, with the usual hairs or slender bristles along the inner curvature. The second and third thoracic segments are a little shorter than the others, which are of about equal length. The fourth and fifth segments are widest. The first segment is produced at the sides around the head so as to very nearly attain the anterior lateral angles of the head, and often so as to obscure the lower margin of the eyes. The epimeral su- tures are scarcely distinguishable in this segment, but evident in the following segments. The epimera are rounded behind as far as the fourth, but the fifth is slightly angulated, and the sixth and seventh acute and produced backward beyond the margin of the corresponding segment. The first pair of legs are short and stout, and well armed with spines and bristles; the basis is of the ordinary form ; the ischium is nearly triangular, having the upper margin much produced in the distal portion and bristly ; the merus is expanded in a somewhat similar manner, but the angle is bent forward beyond the short carpus over the base of the propodus; the opposite or lower margin of the merus is armed with short stout spines; the carpus is short and small and possesses but little motion on the propodus, which is robust, somewhat curved, and bears a strong short dactylus. The second and third pairs of legs resemble the first pair, but the carpus increases somewhat in . size, and there is more motion in its articulation with the propodus. They are directed forward, while the remaining pairs are usually directed backward and are more flattened. The fourth pair of legs are short like the first three (pl. X, fig. 62 b), but, except in size, resem- ble the following pairs. They are well provided with bristles in tufts, and along the margins of the segments, and especially the merus and two adjacent segments, are armed with long stout spines. The pro- podus is straight and much more slender than the carpus. The fifth and sixth pairs of legs increase in size, and the propodus especially be- comes more elongated, but the seventh pair are a little smaller than the sixth. The pleon is scarcely narrower at base than the last thoracic segment, and the first segment is often nearly concealed by the last thoracic. The fifth segment is longer on the back but shorter at the sides than the preceding segments. The last segment, or telson, is triangular with the ciliated apex truncated and emarginate or notched at the end of a short median furrow at the tip. The uropods (pl. X, fig. 63) slightly surpass the telson and are strongly ciliated; the inner ramus bears also a few spines near the tip; the basal segment has the inner angle produced along the margin of the inner ramus, which is broad and expanded - = MARINE ISOPODA OF NEW ENGLAND, ETC. o8l . distally, with a notch at the external angle; the outer ramus is slender ’ = aided and tapering, slightly surpassing the inner. Length of large specimens 32™, breadth 10™", but usually smaller; 22™™Jong, 7™™ broad. The ground color in life is yellowish, with reddish brown on the anterior margin of the head and on the posterior margins of the segments, especially in the dorsal region, where the segments are also marked with black dots. In life the body is somewhat translucent in the thinner parts. In alcohol the translucence disappears and the color fades to a nearly uniform yellowish or buff with black dots. This species was described by Stimpson from Charleston, S. C. Most of the specimens in the collection are from Vineyard Sound !, where it occurs sometimes in great abundance, and is common especially during the winter. It is found swimming about in shallow water, and may be taken in a scoop-net, and is found also in lobster-pots. It was dredged in 45 fathoms off Block Island!, near the eastern end of Long Island Sound, in 1874, but has not yet been found north of Cape Cod. ; Specimens examined. al on rs Z When col. & g Dry. i Bottom. ~ |Receivedfrom—| & a Z Locality E ‘ottom looted. eceived from. 25 Ain A Fi Bo Bel WO Hishers Wsland: -6.<2..5|2s5-scne|essseos--- === -- May —, 1875 | J. H. Latham..| 100+) Alc. Pir eV MGVALC SOUNG: - 32. .25225|s—55-nce|omscereamnan=-=- Mar. —, 1874 V.N.Edwards| 10 | Alc. velit | 506 60 (eee ee ea She) Alene eS eee Aug. 25, 1875 | U.S. FishCom.| 1 | Ale. 2062 | Eel-pond, Wood’s Holl ....|....---. Muddy. ..---. Sly 23) TBS eae Oee saat 100+} Ale. male) CHL NOW SHOLONAMD |5- cb o|oo<-coo+| a cccencccasne = Aug. 19, 1874)... 2-d0\.-5-.252. 1 | Ale. 2064 | Off Martha’s Vineyard....| 18 Sandy .......- Sept. 20, 1875 |....do ........- 1 | Alc. Cirolana polita Harger (Stimpson. ) 4iga polita Stimpson, Mar. Inv. Grand Manan, p. 41, 1853. Liitken, Vidensk. Meddel., 1859, p. 77, 1860. Verrill, Am. Jour. Sci., III, vol. v, p. 16, 1873. Conilera polita Harger in Smith and Harger, Trans. Conn. Acad., vol. iii, pp. 3, 22, 1874. Verrill, Am. Jour. Sci., III, vol. vii, p. 411, 1874. Cirolana polita Harger, Proc. U.S. Nat. Mus., 1879, vol. ii, p. 161, 1879. This species so closely resembles the preceding, that a full description would be little else than a repetition of that given above. It appears, however, to differ constantly from the form already described, by its somewhat more elongated and cylindrical body; in the eyes, which are “ elongate trapezoidal in shape, narrowest anteriorly,” and in the tip of the telson, which is regularly rounded or slightly pointed at the tip with- out any truncation, much less any emargination, and is not at all grooved above. Length 25™™, breadth 6.5"; color much as in the preceding species. Dr. Stimpson’s specimens were “found on the fine sands at low-water mark on High Duck Island,” in the Bay of Fundy, and the specimens that I have examined are from Cape Cod Bay!; from near Salem!, Mass. ; 382 REPORT OF COMMISSIONER OF FISH AND FISHERIES. ‘George’s Banks!, and east of Banquereau!, or Quereau, latitude 40° 367 north, longitude 57° 12’ west, where seven fine specimens were taken from a halibut (Hippoglossus), June 2, 1879, by Capt. J. W. Collins. It appears to replace the preceding species at the north. Specimens examined. ra om 5 : Z } When col- 5 3 D Fi Locality. g Bottom. lected. [Received from— 2s ‘Ale Z es easy Cape Cod Bay.....-....--- 7 Aearae, yellow | Sept. 15, 1879| U.S. FishCom.| 2 | Ale. sand. 1314 sae hs Bank, ee 41° 40/ 25 | SAMs te. cic ———, 1872 |SmithandHar-|} 1 | Ale. -, lon. 68° 10’ W. ger. 1399 eorece poy se 42° 11’ 150 | Soft, —— dy | ———, 1872 ali are and 1 | Ale. Y., lon. 679 71/ W. mud. ooke. Salen: WMIRAS. Cara lick coo kon| cnee ee te] eee nneeeeemiee — —, 1878 | J.H.Emerton.|} 1 | Ale. East Quereau ......--. Bee ec! el eee eee aa ee June 2, 1879 Capt. J.W.Col-| 7 | Ale. 8. X.—AHGIDA. Front formed of the approximate basal segments of the antennulz, which are not covered by an anterior projection of the head; antennule and antenne presenting an evident distinction into peduncular and flagellar segments; maxillipeds operculiform; mandibles formed for piercing, palpigerous, mouth suctorial; first three pairs of legs ancoral, last four ambulatory ; epimera distinct behind the first thoracic segment; uropods lateral, biramous, ciliated, and flattened. This family was represented within our limits by a single species of the typical genus until the summer of 1879, when a single specimen was collected of a second genus belonging to the Agide, but having evident relations with the next family, and in many characters intermediate be- tween d7ga and the Cymothoide. The two genera by which the family is at present represented on our coast may be further characterized as follows: Both the antennule and the antenne are directed laterally, the former arising near together on the anterior margin of the head and forming part of the outline of the animal as seen from above. They, as well as the antenne, present an evident distinction into peduncular and flagellar segments. The maxillipeds are operculiform, and have the palpus armed with short hooks for adhesion to the surface of the fish on which they may be feeding. The mandibles are armed with a horny point, but not toothed as in the Cirolanida, and, while fitted for piercing, are not capable of lacerating and biting off pieces of flesh as in that family. The first three pairs of legs are ancoral, or armed with strong curved dactyli, which, once implanted in the body of a victim, retain their hold without effort—a structure which attains its fullest development in the. ¢ — eS ae ee ee ee oe ee EEE ST ee ee eee ee eee a MARINE ISOPODA OF NEW ENGLAND, ETC. 383 following family. The remaining pairs of legs are fitted for walking. The thoracic segments are subequal in length and have the epimera well separated, except in the first segment. The pleon may or may not be suddenly narrower than the last thoracic segment, and, in our species, is composed of six distinct segments, of which the last is large and secutiform. The uropods are composed of a basal segment, oblique at the apex with the inner angle more or less produced, and bearing two flattened, ciliated rami; they are distinctly lateral, being inserted high up on the sides of the last segment. This family contains our largest Isopod, Aga psora, and to it should probably be referred the huge Bathynomus giganteus A. Edwards, from the Gulf of Mexico, measuring more than eleven inches in length. It has usually been regarded as embracing the Cirolanide. I have already given my reasons for separating them, but have to regret my inability to examine many types of genera apparently more or less intermediate in position between ga and, on the one hand Cirolana, and on the other Cymothoa and Livoneca. I have therefore retained the old classification rather than to unite the following genera with the Cymothoida. Our two genera are most easily distinguished as follows: Eyes large and approximate, diga, p. 89; eyes wanting, Syscenus, p. 93. : OO Se ee ee ga Leach. diga Leach, Trans. Linn. Soce., vol. xi, p. 369, 1815. Byes large; palpus of maxillipeds five-jointed ; three anterior pairs of legs terminated by strong curved claws; posterior pairs slender, with slender nearly straight dactyli; pleon not suddenly narrower than the thorax; pleopods ciliated. This genus is represented within our limits by a single species, which may be easily distinguished by its large approximate eyes. The basal segments of the antennule are flattened and the flagellum is compara- tively slender. The maxillipeds have a five-jointed palpus, which is short and flattened and bent around the oral opening, and the inner margins of the three terminal segments are provided with a row of strong hooked spines, which are also found upon the outer maxille, thus forming two rows of short hooks on each side of the mouth, by means of which the opening of the mouth can be closely applied to the fish on which these animals prey. The inner maxille are slender and styliform and armed with sharp curved spines at the apex, and the mandibles are also acute and fitted for piercing. The body is moderately convex, and the last four pairs of legs are nearly alike ambulatory and of moderate length, the last pair, when extended, scarcely surpassing the telson. The pleon is composed of six distinct segments, and the basal segment of the uropods is strongly produced at its inner angle, as usual in the family. The pleopods are ciliated in the adults as well as in the young. 384 REPORT OF COMMISSIONER OF FISH AND FISHERIES. #Gga psora Kroyer (Linné). Oniscus psora ‘‘Linné, Fauna suecica, ed. ii, 1761”; Syst. Nat., ed. xii, tom. i, p. 1060, 1767. “Pennant, Brit. Zool., vol. iv, pl. 18, fig. 1, 1777 (certe)” (B. & W.). O. Fabricius, Fauna Greenlandica, p. 249, 1730. Mohr, Islandisk Naturhistorie,.p. 110, 1786. Aiga emarginata Leach, Trans. Linn. Soc., vol. xi, p. 370, 1815; Dict. Sci. nat., tome xii, p. 349, 1818. Samouelle, Ent. Comp., p. 109, 1819. Desmarest, Consid. Crust., p. 305, pl. 47, figs. 4, 5, 1825. Griffith and Pidgeon, Nat. Hist. Crust., p. 218, pl. viii., fig. 3, 1833. Edwards, Hist. nat. des Crust., tome iii, p. 240, 1840; Regne Anim., Crust., pl. iv, fig. 4, and pl. Ixvii, fig. 1, 1849. Gould, ? Rep. Geol. Mass., p. 549, 1835; Invert. Mass., p. 338, 1841. Gosse., Man. Mar. Zool., vol. i, p. 134, 185%. Alga (Oniscus psora) Kroyer, Grénlands Amfipoder, p. 318, 1838, Aga psora Lilljeborg, Ofvers, Vet.-Acad. Férh., 1850, p. 84, and 1851, p. 24. Liitken, Vidensk. Meddel., 1858, pp. 65, 179, 1859; ibid., 1860, p. 181 (7) 1861; Crustacea of Greenland, p. 150, 1875. Schiddte, Ann. Mag. Nat. Hist., IV, vol. i, p. 12, 1868. Bate & Westwood, Brit. Sess. Crust., vol. ii, p. 283, figure, 1868, M. Sars, Chr. Vid. Selsk. Forh., 1868, p. 261, 1869. G. O. Sars, Hard. Fauna, Crust., p. 275 [32], 1872. Verrill, Am. Jour. Sci., III, vol. v, p. 16, 1873. Smith and Harger, Trans. Conn. Acad., vol. iii, p. 22, 1874. Whiteaves, Further Deep-Sea Dredging, Gulf St. Lawrence, p. 15, 1874.” Metzger, Nordseefahrt der Pomm., p. 285, 1875. Meinert, Crust. Isop. Amph. Dec. Danie, p. 89, ‘¢1877.” Miers, Ann. Mag. Nat. Hist., IV, vol. xix, p. 134, 1877. Harger, Proc. U. 8. Nat. Mus., 1879, vol. ii, p. 161, 1879. Aiga ertaillée Latreille, Regne Anim., tome iv, p. 134, 1829. PLATE X, Fig. 64. The present species is the largest Isopod, and indeed the largest Tetradecapod known on the New England coast, reaching a length of nearly or quite two inches and a breadth of one inch, and has even at- tained to the dignity of a popular name, “salve-bug”, by which it is known among fishermen. It may be further distinguished by its large approximate eyes, covering a large proportion of the upper surface of the head, and by the possession of ancoral legs in three pairs only, the last four pairs of legs being fitted for walking. The body is oval, broadest at the fourth and fifth thoracic segments, where the breadth is about half the length. The dorsal surface is moderately convex and smooth except for minute and rather scat- tered punctations, which occur also on the legs, especially on the basal segments, on the antennule, the uropods, and even the pleopods. The head is transverse and sub-triangular, salient in front between the bases of the antennule. Much of the upper surface of the head is covered by the large oval or somewhat reniform eyes, which do not quite meet on the median line. The antennulze when bent backward nearly or quite attain the anterior margin of the first thoracic segment, and a “MARINE ISOPODA OF NEW ENGLAND, ETC. 385 have their first two segments large and flattened, and wedge-shaped in front; of these the basal segment is quadrate in outline, as seen from above, and nearly as broad as long; it closely approaches its fellow of the opposite side in front, but is separated from it behind by a median process of the head ; the second segment is triangular in outline, as seen from above, with the apex of the triangle extending beyond the origin of the third slender cylindrical segment, which is followed by a tapering flagellum of about a dozen segments. The antenne when reflexed extend beyond the first thoracic segment and have the first two seg- ments short and compressed, the third somewhat longer, the fourth and fifth longer and nearly cylindrical, followed by a tapering flagellum about as long as the peduncle and composed of fifteen to twenty seg- ments. The mavxillipeds have a short triangular external lamella and a five-jointed palpus, of which the first segment is short and transverse; the second is triangular and bears, on its inner apex, a few slender hooked spines; the third segment is broad and flattened, with the inner margin short, and armed with about three robust hooked spines; the fourth segment is flattened and transverse and armed along its inner margin with about six similar spines; while the fifth segment is small, sub-oval, and armed with much more slender curved spines. The outer maxillz are provided with curved spines at the apex much like those of the maxillipeds. The inner maxille are rod-like and terminate in sharp somewhat curved spines placed close together. The mandibles support a'slender palpus of three segments, of which the middle one is much the longest, and the last is robust and sickle-shaped, with a comb of short spines along the inner curve. This segment lies, in the ordinary posi- tion, just at the base of the antenna of the same side. The first thoracic segment is, at its anterior margin, scarcely broader than the head, but expands rapidly backward. It is excavated in front for the eyes, which project somewhat beyond the posterior margin of the head. The second, third, and fourth thoracic segments are each a little shorter than the first; the fifth and sixth are somewhat longer; the seventh is shorter than the sixth. The epimera of the first thoracic seg- ment are not separated by suture, but in the second and following seg- ments they are so separated, and, especially on the anterior segments, marked with two oblique depressed lines. The epimera of the second, third, and fourth segments are rounded or truncate behind, but in the posterior segments they become acute and extend beyond the angles of the segments to which they are attached. The first three pairs of legs are short and armed with strong hooked dactyli. The propodal seg- ments are also curved, and the carpus is short in the first pair but somewhat longer in the second and third pairs. The merus is almost crescent-shaped in the first pair of legs, its horns embracing the carpus above and below, but it becomes more elongated in the succeeding pairs; in all three pairs its inferior margin is armed with a few short, stout spines. The fourth and succeeding pairs of legs are of quite a different 25 F 386 REPORT OF COMMISSIONER OF FISH AND FISHERIES > “type from the first three. The four segments following the first or basal one are straight, cylindrical, or slightly compressed, armed with short spines, especially below and at the distal end, subequal in length but decreasing in diameter to the propodus, which bears in each pair a short, slightly curved and comparatively weak dactylus. The seventh pair is only imperfectly developed in the young specimen figured, but never quite attains the size of the sixth pair, which is the largest. The pleon is scarcely narrower than the last thoracic segment and tapers but little to the fifth segment. The last segment is triangular, with the sides but little dilated, and is pointed at the tip without grooves or carinations. The uropods searcely surpass the telson; the basal seg- ment has its inner angle long and spiniform, extending the whole length of the inner margin of the inner ramus and ciliated toward the tip; the rami are flattened, the outer elongate ovate, obtuse; the inner with the inner margin straight, the outer curved and emarginate near the tip. Both rami and the posterior part of the telson are ciliated. Length 16-50", breadth 7-25™"; color in paleohol light brown, darker toward the head; eyes black. Linné’s oneapaiin of Oniscus psora is too indefinite to be certainly recognizable, and in using his trivial name I have followed the au- thority of Liitken and others. Our specimens agree well with the de- seription of O. psora by O. Fabricius, and are undoubtedly identical with that species, which he describes as infesting the cod. They appear to correspond also with Bate and Westwood’s figure and descriptions, al- though those authors make no mention of Fabricius under 4. psora. As Kroyer referred the species to its proper genus, I have adopted his name as authority for the combination. The specimen figured was dredged in the summer of 1872, a little to the northeast of St. George’s Bank !, in latitude 42° 11/ north, longitude 67° 17’ west, in 150 fathoms, soft sandy mud with a few pebbles, and is young, as shown by its size and imperfectly developed seventh pair of legs. Adults may surpass the size of the figure, but the specimen drawn was enlarged three diameters. Adult specimens were obtained from the Provincial Museum, Halifax, Nova Scotia, labeled as found on the cod, and were probably from the fishing banks of that region, or from the Banks of Newfoundland. During the summer of 1879 a considerable number of specimens were received by the Fish Commission through the Gloucester fisheries, of which only a few are included in the table of specimens examined. These specimens were parasitic on the cod (Gadus morrhua),; and on the halibut (Hippoglossus). Specimens have also been obtained from the skate (Raia). Whiteaves records this species from a halibut, on the north shore of the Gulf of St. Lawrence. Fine speci- mens were obtained by Mr. N. P. Scudder from off Holsteinborg, Greenland, in Davis’ Straits!, parasitic on the halibut, and collected in July and August, 1879. It extends to Iceland (Edw. e¢ al.); the British Isles (B. and W.); the North Sea (Metzger); Finmark (Sars), and Spitz- bergen (Miers). a MARINE ISOPODA OF NEW ENGLAND, ETC. 387 Specimens examined. ml . = n : : 58 F Locality. : Parasitic on— ba oi Received from— me rid 3 BS A ce i 1398 toe s Bank, lat. HOO} [eatece sented —— —, 1872} PackardandCooke| 1 | Ale. OntT N., lon. 67° i W. OED | 3. ok SSE eB EE, To ERE BeRenn ie rote Seed Soc rar ao De mee Giants Mus.,Hal-| 2 | Ale. lax. George's Bank. ......2|-<2-0---|-s20-0/.--5.<-46- —— —, 1878| Schooner Alice G.| 3 | Ale. ‘Wonson. a AG ion seeectes eee en|-sese=2- | GOs -... 3.) May 8),1879)| 0.) Shemelisy =.=. 3 | Ale. 2oeae eee me cecelecn ee cles GO} secs 6s | May £5, 1879 pet J.Q.Getchell| 9 | Ale. N. E. George’s Bank. . 47 B00 Reece Nov. 29, 1878 Shemelia. ....| 3 | Ale aoz | Gult or Maine. .-...5--].-2-.2<- “Skate (Raia) ..| —— —, 1878| U.S. Fish Com’n..| 20 | Ale. 2156 | Banquereau...........|.-....-- Halibut....... —— —, 1878| Schooner Marion..| 1 | Ale. Cig | Se ee he a 40-50 | Codfish ....--.. —— —, 1878| Schooner Rebecca} 1 | Ale Bartlett. 2158 | Grand Menan Bank... JO) |Secacscs ants codes —— —, 1878 yard Peter D. 3 | Ale mith. 2155 |.----- Gaeiceeen cian aaa a eee eee eee —— —, 1878| U.S. Fish Com’n..| 1 | Ale. Brown's Bank. ...-.---. 52 | Codfish :...... Dee. 19,1878} Mr. Isaac Butler - 2 | Alec. ena OG) see oteenacnen ae|asoees <-(oeesOO 55. 225-5| HOD. 13, 1879 Capt. J. Q. Getchell 2 | Ale. oe OG Sse SII 3. S050 222 L 0.2 | Miay 1, 1879.|.0..do siocas occu les|) (82 feAiles Lat. 48° 25’ N., Lon. 180 | Halibut ...... Aug. 21, 1879 Capt. S. W. Smith |...... Alc. 60° W. and crew. TDS VIS’S SEPAIUS< 60 30 ccehtinwesiens|acus OO! a sccsenan —— —, 1879) Mr. N.P.Scudder.} 10 | Ale. Syscenus* gen. nov. Eyes wanting; palpus of maxillipeds two-jointed; sixth and seventh pairs of legs elongated; pleon suddenly narrower than the thorax; pleopods naked. This genus is unfortunately represented in the collection by a single specimen. It differs from Aga by characters that point toward the Cymothoide, as in the reduction of the segments of the palpus of the maxillipeds, the sudden constriction at the base of the pleon, and the naked pleopods. The absence of eyes, although a conspicuous charac- ter can hardly be regarded as of great taxonomic value. It is separated from the Cymothoide by the form of the head, which is not produced over the bases of the antennule but merely projects slightly between them. The antennulz moreover are composed of three peduncular seg- ments and a flagellum; the basal segments are much smaller than in Afga and less flattened, but still form a part of the anterior outline when seen vertically. The last four pairs of legs differ from the first three, and are more or less elongated and fitted for crawling. The uropods are distinctly ciliated. Syscenus infelix sp. noy. This species may be recognized among our Isopoda by the possession of the full number of segments, the ciliated uropods, naked pleopods, and the absence of eyes. * Yhoxnvoc, a messmate. 388 REPORT OF COMMISSIONER OF FISH AND FISHERIES. The body is more than twice as long as broad and only moderately convex. The head is small and as seen from above is transversely somewhat diamond-shaped with rounded angles. It presents in front a slight prolongation between the antennulz, and on each side of the short median process its outline is excavated above the bases of the antennule. The posterior margin is curved, but near each end is a faint indication of a lobe, projecting backward like the ocular lobes in Afga, but the eyes are wanting. The antennule arise near together on each side of the front and are short, extending when reflexed but little beyond the lateral margins of the head and only slightly surpassing the fourth antennal segment. They are readily distinguishable into pe- duncular and flagellar segments, the first three segments being of com- paratively large size and about equal length; the second segment much flattened below against the antennz; third more slender than the first two and followed by a short, tapering six-jointed flagellum. The anten- nule are in their natural position reflexed, the second segment being articulated at an angle with the first. The antennez are considerably longer than the antennule and, when reflexed, slightly surpass the pos- terior border of the third thoracic segment. They are inserted below and a little outside of the antennule. The first segment is short and flattened below; the second is also short, the two together being hardly longer than the basal antennular segment; the third segment is about as long as the first two together, and the fourth is a little longer than the third, but of slightly less diameter; the fifth is more than one-half longer than the fourth, but is more slender and is followed by a slender, tapering flagellum of about twenty-four segments. The last two pe- duncular segments bear a row of elongate bristly hairs along the margin which, when reflexed, is brought next the body, and the row is continued, though with shorter hairs, along the flagellum. The palpus of the maxil- lipeds is composed of two segments of which the first is nearly square and armed at the inner distal angle with a minute hook; the second is bluntly triangular and armed at the apex, which is directed inward, with three hooklets. The external lamella is small and subcireular. The outer maxille are armed with short hooks at the tip; the inner with minute denticles. The mandibles are flattened and denticulate at the tip and bear a three-jointed palpus of which the three segments decrease in size to the last. The first thoracic segment is twice as long as the second; its anterior margin is adapted to the head; its posterior margin is nearly straight above and rounded at the sides until the epimeral region is reached, when a short, pointed projection juts backward, being the tip of the epimeron on each side, here united with the segment. The next three —second, third and fourth—thoracie segments are of about equal length, and each a little over half the length of the first segment; their pos- terior margins are nearly straight above and rounded at the sides; the third segment is broadest. The fifth and sixth segments are each a- ——— MARINE ISOPODA OF NEW ENGLAND, ETC. 389 little longer than the second; the seventh about as long as the second. The last segment, and in a less degree the sixth and fifth segments, have their posterior margins excavated along the back; .all have their lateral angles rounded, although the angles of the seventh segment are but slightly so. The epimera are short and pointed; those belonging to the second and third segments are larger than the following ones, and are applied directly to the lateral margin of the segments; the posterior four pairs of epimera are shorter and smaller, and are separated from the lateral borders of the segment by a fold of the integument cutting off a portion of the anterior lateral angle and increasing in size to the last segment. The first three pairs of legs are alike, distinctly ancoral and directed ferward. In each the basis is much the longest segment; the ischium ' is strongly flexed upon it; the merus is expanded distally around the base of the carpus and bears a few bristles at the outer angle; the carpus is short, less than half as long as the propodus, and the dae- tylus is strong and curved. The fourth pair of legs, like those that follow, is directed backward; the basis is the longest segment and the ischium is strongly flexed upon it and of more than half its length; the merus, carpus and propodus are each about two-thirds as long as the ischium, and all four segments are armed distally with a whorl of spines around the articulation with the succeeding segment; the dactylus is slender, sharp and curved. The fifth pair of legs is longer than the fourth by a little more than the length of the dactylus, the elongation being in the segments from the ischium to the propodus inclusive. The sixth pair is the longest, being, when extended, as long as the thorax and pleon together. This elongation is confined also to the four seg- ments above indicated, and of these the ischium is about as long as the basis; the merus falls a little short of the ischium in length; the carpus and propodus are of equal length, and are as long as the ischium; all these segments are slender and slightly curved, and are armed distally and along their inner side with short spinules. The dactylus is slender and curved. The seventh pair of legs resembles the sixth but is shorter by about half the length of the propodus. The fifth pair does not attain the middle of the carpus of the sixth. The pleon is of less diameter than the last thoracic segment and about as long as the last five thoracic segments. Its transverse diame- ter increases slightly to the base of the last segment, where it is broad- est; the fifth segment is a little longer than the preceding one, and the last segment is of a broad ovate form, acuminate and ciliated at the tip, truncated at the base and smooth above, except for a faint trans- verse impression on each side near the base, and a still more faint im- pressed median line toward the tip. The uropods attain the tip of the telson but do not surpass it; they have the basal segment oblique but | not produced at the inner angle, and bearing two elongate-elliptical yr 390 REPORT OF COMMISSIONER OF FISH AND FISHERIES. © rami, tapering at the base and ciliated, the inner about one-third longer than the outer. The pleopods are quite naked and destitute of cilia. Length 23"™; breadth, 9™™; breadth of pleon 4™™; length of head 3"™; breadth 4.2™" ’ A single specimen of this species was dredged by the U. 8S. Fish Commission, about fifteen miles northeast of Cape Cod!, in 130 fathoms brown mud, September 10, 1879. . XI.—CYMOTHOID i. Head produced anteriorly over the bases of the antennule ; maxillipeds few-jointed, operculiform; mandibles palpigerous; mouth suctorial; legs armed with strong curved dactyli; epimera distinct behind the first thoracic segment; telson large and flattened; pleopods not ciliated; uropods articulated near the antero-lateral angles of the last segment, and composed of a more or less flattened basal segment bearing two flattened rami; habit parasitic; body often unsymmetrical by distortion in the adults. This family is represented within our limits by three genera and as many species. They are parasitic in habit, usually on fish, and fix them- selves by their strongly-curved claws to their host, often within the mouth, or about the branchial cavity, and frequently become distorted when fully grown. Im all our species the head is small, and has the anterior margin produced, concealing the bases of the antennule and the antenne. The head is three-lobed behind, and the first thoracic segment is adapted to it. The antennule and antenne are both short and tapering, without very evident distinction into peduncular and flagellar segments. This distinction is, however, usually more or less evident on examination. The epimera are well separated, except in the first segment, and may be projecting and conspicuous. The legs are of nearly the same form throughout, but increase in length and become more slender posteriorly.* The basal segments are in some genera enlarged and flattened, but not in ours; the joint between the basis and ischium is strongly flexed, and the segments, at least beyond the ischium, to the dactylus, are short and capable of but little motion on each other. The dactylus is strongly curved and admirably fitted for firm attachment to the host on which the animal may be living. In our species the legs, in the natural position, are concealed in a dorsal view beneath the body of the animal, to the under surface of which they are appressed, the first three pairs being directed forward, and the last three backward, as represented in plate X, fig. 66. The pleon in our species is not suddenly narrower than the thorax, as it is, however, at least in the adults, in some genera belonging to this family. The segments of the pleon are distinct, the last one scutiform “In ArtystoneSchiddte the seventh pair of legs ‘‘reach to the extremity of the tail and are slender, compressed crawling legs, with a small, almost rudimentary, straight claw.” MARINE ISOPODA OF NEW ENGLAND, ETC. 391 and of moderate size, not being greatly enlarged. The pleopods are destitute of cilia in the adults. This family is evidently closely related to the preceding and may yet have to be united with it, or even be extended so as to include also the Cirolanide. Our representatives of the three families are so few that T have had little opportunity to study the genera, and as before stated, I have separated the Cirolanide principally in deference to the opinions of Schiddte. Alitropus Edwards, Syscenus Harger, and Afgathoa Dana may be mentioned as genera pointing toward a transition between the Aigide and Cymothoide, and it is evident that the latter family is made up of forms degraded by parasitism. They have thus exchanged the ambulatory legs of the Agide for strictly ancoral legs, for the most part in seven pairs, and have lost the natatory cilia of the pleopods. Their antennary organs are also much less perfect than in that family. All these modifications are in the line of the sedentary life of a parasite. The interesting observations of Mr. J. F. Bullar have shown that in certain genera of the Cymothoide (Cymothoa, Nerocila, Anilocra) a peculiar form of hermaphroditism occurs, the young at a certain stage of devel- opment being males with well developed testes and external organs, but possessing at the same time ovaries with the oviduct ending blindly. As development proceeds the male organs are lost by molting, the ovi- duct obtains an external opening, the incubatory pouch is developed, and the animal becomes a female. Mr. Bullar’s statements provoked considerable discussion, but they have recently been verified by Mayer, who has, however, shown that self-fertilization does not occur. Three genera of Cymothoide are represented within our limits by as many species, and a fourth species, Cymothoa pregustator Say* (La- trobe) may yet be found, being not a rare parasite in the mouth of the menhaden (Brevoortia menhaden Gill) in southern waters. The projec- tion of the front of the head over the bases of the antennary organs, and the strongly hooked or ancoral legs are characteristic of the family, and the genera may be distinguished by means of the following table: ciliated, eyes large conspicuous, Aigathoa, p. 393 . Uropods) ales heads { symmetrical ; posterior epimera elongated, Nerocila, p. 391 unsymmetrical; epimera short, Livoneca, p. 394 Nerocila Leach. Nerocila Leach, Dict. Sci. nat., tom. xii, p. 351, 1818. Body oval; head small; eyes of moderate size; posterior thoracic seg- ments and epimera angulated or spiniform, giving a sharply serrated or dentated outline to the thorax; first two “abdominal epimera” also spiniform; pleon of six distinct segments. Our species of Nerocila has the characters of the genus much less pro- nounced than some foreign ones, as the posterior epimera are nearly * Jour. Acad. Nat. Sci. Phila., vol. i, p. 395, 1818. 392. REPORT OF COMMISSIONER OF FISH AND FISHERIES. - or quite concealed from above by the projecting angles of the segments, and the “abdominal epimera” are mostly concealed beneath the pleon. These organs are the much elongated inferior angles of the segments, which in allied genera, as -Agathoa, are short and not produced. Ina lateral view they considerably resemble the posterior epimera, giving the appearance of two additional pairs. The specimen first described is smaller than others that have since been obtained. Nerocila munda Harger. Nerocila munda Harger, This Report, part 1, p. 571 (277), 1874; Proc. U. S. Nat. Mus., 1879, vol. ii, p. 161, 1879. Verrill, This Report, part i, p. 459 (165), 1874. PLATE: X, Fre. 65: This species may be recognized among our Isopoda by the projecting posterior epimera, and the two pairs of spiniform “abdominal epimera” beneath the pleon. The body is oval, twice as long as broad, smooth, polished, and mod- erately convex. The head is flattened, broader than long, narrowing anteriorly, broadly rounded or subtruncate in front, three-lobed behind, with the middle lobe largest. The eyes are black and consist of an irregularly rounded patch of small indistinct ocelli, and are visible both above and below. The antennule are about as long as the head, and composed of eight segments, of which the first is short, the second is the longest, and the remaining six decrease pretty regularly in size to the last.. The antenne are a little longer and more slender than the antennul and have the first segment short, the second subglobose, the third, fourth, and fifth cylindrical, and a little larger than the segments of the flagellum, which areabout fiveinnumber. The mandibular palpi are longer than any three segments of the antenne, and the first seg- ment is large, the second elongate conical, the third shorter, cylindrical. The first thoracic segment is much longer than the succeeding ones and adapted to the head in front. It is slightly produced at its lateral angles behind, or rather appears so from the union of the epimera, which really constitute the projecting angles to the segment. In the second, third, and fourth segments the posterior angles are. but little produced, and are equaled or slightly surpassed by the epimera, but in the last three segments the posterior angles are acutely produced much beyond the epimera of the corresponding segments, the angle of the sixth segment nearly attaining the end of the seventh epimeron. In a lateral view, only the last two epimera are decidedly acute, while those of the second and third segments are obtuse and rounded behind. Seen from below, the posterior angles of the epimera are acute throughout. The first pair of legs are slightly more robust than the second and third ; the last four pairs are still more slender, the last pair longest, and the last two pairs armed with a few short spinules. The pleon is shorter than the thorax and much narrower, though \ MARINE ISOPODA OF NEW ENGLAND, ETC. 393 not suddenly so and tapers but little posteriorly; the telson is flat- tened, and regularly rounded behind. The ‘ abdominal epimera” are acute, the second smaller and more slender than the first, but their ex- tension backward varies with the state of contraction of the pleon. The uropods (pl. X, fig. 65 a) surpass the telson, and have the inner angle of the basal segment sharply produced. The rami are flattened; the ex- ternal one twice the length of the basal segment, narrowly ovate or lan- ceolate, sometimes slightly curved, and surpassing the telson by half its length. The inner ramus is narrowly oval, obliquely truncate behind and about three-fourths as long as the outer. The length of the specimen figured, which was the one first described, is 15™™, breadth 7™™, but specimens measuring 25"™ in length have since ise collected ; ales brown or greenish, with two narrow dorsal bands of lighter ies, most evident at the extremities. The original specimen was obtained on the dorsal fin of Ceratocanthus aurantiacus at Wood’s Holl!, Vineyard Sound, in 1871, and two more specimens of larger size (oie since been obiained, also from Vineyard Sound!, Mass. #igathoa Dana. Aigathoa Dana, Am. Jour. Sci., II, vol. xiv, p. 304, 1852. Body elongate oval; pleon not suddenly narrower than the thorax ; head large, subtriangular; eyes large; legs nearly alike throughout, with strong curved dactyli; epimera of moderate size or small; pleon long and large, composed of six distinct segments; pleopods not cili- ated; uropods more or less distinctly ciliated, rami subequal. This genus is represented in our fauna by a species parasitic in the mouth of a squid. The large, granulated eyes remind one of Aga, and the ciliated uropods also indicate the approximation of this genus to the preceding family. The ciliation is, however, nearly rudimentary in our species, and is present, at least in the young, of other members of the Cymothoide. égathoa loliginea Harger. Aigathoa loliginea Harger, Am. Jour. Sci., III, vol. xv, p. 376, 1878; Proc. U. 8. Nat. Mus., 1879, vol. ii, p. 161, 1879. PLATE X, FIG. 66. The legs all armed with strong curved claws, the large conspicuous eyes and the slightly ciliated uropods serve to distinguish the present species from the other ISopoda of our coast. Body elongate oval in outline, nearly four times as long as broad, slightly dilated near the posterior end. Head broadly rounded in front, subequally, but not deeply, trilobed behind. Eyes large, with evident facets, lateral, semi-hexagonal, visible from below, covering nearly half the area of the head above, projecting posteriorly beyond the middle 394 REPORT OF COMMISSIONER OF FISH AND FISHERIES. lobe of the head. Exteriorly they form about two-thirds of the lateral margin of the head. Their interior boundary is in the form of three sides of a hexagon, separated at their nearest points by a little more than the transverse diameter of the eye. The antennulz are about as long as the head, composed of eight segments and separated at the base. The first segment is short and stout; the next two a little longer, but scarcely distinguishable from the following five flagellar segments, which decrease in size to the last. The antenne are composed of ten segments. They are more slender than the antennule, and surpass them by about two segments. The first two segments are broader than the following three, which are also somewhat larger than the five flagellar segments. The first thoracic segment is shorter than the head, but much longer than any of the succeeding segments, which to the sixth are of equal length, each about one-third shorter than the first. The seventh segment is about one-third shorter than the sixth. The fifth and sixth are broadest, each being about one-third broader than the first. The epimera do not project behind the angles of the segments to which they are attached. The legs differ but little throughout. The first pair are shortest, and the first three pairs are somewhat stronger than the last four, which are armed with a few scattered short spinules. The seventh pair are the longest. The pleon is a little longer than the seven thoracic segments. The fifth segment is broader behind than in front, and the last segment is as broad at the insertion of the uropods as the third segment, and is rounded behind. Anterior pleopods with the basal segment nearly square. The uropods are unlike on the opposite sides in the specimen figured. The normal form is probably seen in the right uropod, which surpasses the telson by less than half the length of the outer ramus. This ramus is longer than the inner, narrow, with nearly parallel sides and is obliquely truncated at the tip. The inner ramus is somewhat diamond-shaped. The ciliation is nearly rudimentary and might be overlooked. The basal segment is alike on the two sides and has the inner distal angle acute and but slightly produced. Length 13", breadth 3.6"; color in alcohol yellowish, with minute black specks most abundant on the pleon; eyes black, conspicuous. The specimen was obtained June 1, 1874, by Mr. S. F. Clark, at Savin Rock!, near New Haven, from the mouth of a squid (Lokigo Pealit), whence the specific name. Two specimens “ parasitic on young mullet” are in the Yale College Museum, collected at Fort Macon!, N. C., by Dr. H. C. Yarrow, which appear to belong to this species, showing that it is not confined to the squid. Livoneca Leach. Livoneca Leach, Dict. Sci. nat., tome xii, p. 351, 1818. Head small, projecting in front over the bases of the antennule, which, like the antenne, are short; legs all alike and armed with strong curved dactyli; body broad, oval, often obliquely distorted. . MARINE ISOPODA OF NEW ENGLAND, ETC. 395 - This genus is represented by a single species, in which the body is of a broadly oval form and depressed. All the legs are short and armed with strongly curved dactyli, and, in the natural position, are closely appressed to the ventral surface, which, however, is more or less exposed below along the middle. Livoneca ovalis White (Say). Cymothoa ovalis Say, Jour. Acad. Nat. Sci. Phil., vol. i, p. 394, 1818. Dekay, Zool. New York, Crust., p. 48, 1844, Livoneca ovalis White, Cat. Crust. Brit. Mus., p. 109, 1847. (Lironeca). Harger, This Report, part i, p. 572 (278), pl. vi, fig. 29, 1874; Proc. U.S. Nat. Mus., 1879, vol. ii, p. 162, 1879. - PLATE XI, F1G. 67. this Isopod serves to distinguish it from any other species yet recog- nized within our limits. Body broad, oval, usually oblique, and not, as represented in part I of this report, pl. VI, fig. 29, with the sides of equal length. The legs, moreover, in that figure are in an unnatural position, as they are, dur- ing life, concealed beneath the body of the animal and appressed to the ventral surface, the first three pairs directed forwards and the last four pairs backward. The dorsal surface is moderately convex. The head is small, rounded in front, trilobed behind, the middle lobe much the larg- est, the two lateral lobes extending beyond the eyes, which are not con- spicuous, small and broadly separated. Antennule (pl. XI, fig. 67a) widely separated at the base, with the first segment short and stout; the second longer and somewhat tapering; the third about as long as the first. These peduncular segments are somewhat flattened. The flagel- : lum is longer than the peduncle, tapering and five-jointed, curved back- ward in the natural position, each segment bearing a row of short blunt The broadly oval, more or less distorted and unsymmetrical form of seta, near the distal end, on the inner curve. The antenne (pl. XI, fig. 67b) are about as long as the antennule, with the first two segments short and stout, the next three more slender; flagellum three or four jointed, with the last segment imperfectly divided and tipped with a few short sete. The maxillipeds are narrow, with the outer lamella partially united to the basal segment and the palpus tapering and two- jointed, tipped with a few short curved sete, at least in young individ- uals. The mandibles are pointed; their palpi (pl. XI, fig. 67 c) tapering from the base and composed of three segments of about equal length, the first subquadrate, the second tapering, the third nearly cylindrical. The first thoracic segment is longest; the next three a little shorter and about equal; the fifth and sixth still shorter; the seventh shortest measured along the median line, which is usually a curved line except ‘in young specimens. The anterior margin of the first thoracic seg- ment is adapted to the posterior margin of the head and presents three sinuses, the middle one largest, for the median lobe of the head, and two smaller ones for the ocular lobes. The posterior margin of this segment is strongly convex backward throughout. In the succeeding segments 396 REPORT OF COMMISSIONER OF FISH AND FISHERIES, this convexity rapidly diminishes so that the fourth has nearly a trans- verse margin and the last three segments become coneave behind in an increasing degree. The epimera are narrow and obtusely pointed behind, and do not surpass the posterior angle of the segment to which they are at- tached except in the last two segments. The first pair of legs (pl. XI, fig, 67d) are short and stout, the basal segment large but short; the next three segments short and with little motion on each other; the propodus stout and somewhat curved; the dactylus long, curved, and strong. The second and third pair of legs are much like the first, as are the four suc- ceeding pairs, but somewhat larger and longer. The seventh pair (pl. XI, fig. 67 e) have the basal segment about twice as long as in the first pair, and the succeeding segments are also proportionally longer than in the first pair, except the dactylus, which is slightly weaker and not longer than in the first pair. The pleon tapers rapidly at the sides; its first five segments are sub: equal in length; the last segment forms about half its length, and is flat and broadly rounded behind. Uropods (pl. XJ, fig. 67/) surpassing the telson with the basal segment, about as long as the rami and but little produced at its inner angle; outer ramus linear oblong, rounded at the end; inner ramus shorter and broader, oblique at the tip. Length 17-22™™, breadth 10-12™™. These animals when preserved in alcohol are of a leaden color, with the posterior margins lighter. They are often parasitic on the blue-fish (Pomatomus saltatrix Gill). The details figured on plate XI are from small specimens collected on young blue-fish at New Haven!, by Mr. F.8. Smith. Other localities are Thimble Islands!, Long Island Sound; Vineyard Sound!, Fish Commis- sion 1871, one specimen among scup (Stenotomus argyrops Gill). A specimen was sent to the Museum in 1878, collected by Dr. T. H. Bean, from the gill of Micropogon undulatus caught at Norfolk!, Va., July 9,1878. Specimens examined. 3 Oo H | Bo eeeai| Locality. Parasitic on— pes Received from— | ~ 8 Pee g . Sg : zi | Z 3eueee ANOLIOLES Viaecac-tcme Cocca ee rab Sc ae July 9,1878| T. H.Bean.....-.| 1 | Alc. 2071.| New Haven.......-.-c-..2.-- Bites H Sek Eu eS Soe E.S. Smith Shey! hs 15 | Alc. 2072 See SOUNG). + -caseecorsee pe dO see ented —— —, 1871} U.S. FishCom. - 1 | Ale 21S Pee a ee ee SMe so o8 a Seup Pa Satties oe Aug. 17, ASIEN Jo:do' ss 4te tase 1 | Alc. 1 OEE ea eee ee eee | (A one Oe ae eI eee See me eee Te Cc. 2075 | Vineyard Sound .............. Blue-fish........ Sept. 2,1871| U.S. FishCom.-...| 1 | Ale. ZU ASAE eee Sees te cobain eee coe sects pie en cimwnin ell aia mm efeaima nie min F. H. Bradley..... 1 | Ale. XIT.—ANTHURID i. Body elongate, cylindrical; mouth suctorial; legs ambulatory and pre- hensile, the first pair enlarged; first pair of pleopods thickened and crustaceous, protecting the following pairs; uropods articulated at the sides of the last segment, standing in a more or less vertical position and forming with the telson a sort of cup or flower at the end of the body. : | ‘MARINE ISOPODA OF NEW ENGLAND, ETC. 397 ing to as many genera, which, in addition to the characters given above, agree further in the following particulars: The body is elongated and vermiform, often more than ten times as long as broad, and of nearly uniform size throughout. The head and thoracic segments are all dis- tinetly separated from each other, and the head and last thoracic seg- ment are shorter than the intervening segments, which are subequal. Both pairs of antenne are approximate at their bases, and the lower pair or true antenn are short, not greatly surpassing the head in length. These organs have the basal segment short, the second segment flat- tened internally and adapted to its fellow of the opposite side, while above and externally it is excavated for the basal segment of the anten- nule. The mandibles are palpigerous, and the mouth parts are fitted for piercing and for suction. In the first pair of legs the first, second, and penultimate segments are enlarged and thickened; the two intervening segments, merus and car- pus, are short; the dactylus forms a curved finger tipped with a stout spine and capable of complete flexion on the robust propodus. In one — or two of the succeeding pairs of legs the propodus may be slightly en- larged. The first three pairs of legs have the carpus, or antepenulti- mate segment, triangular, and their basal segments are directed strongly backward. In the last four pairs the carpus may be short, but is not triangular, and always distinctly separates the merus from the propodus ; they are so articulated to the body that their basal segments are directed. forward. The first three pairs of legs are articulated to the anterior part of the segment to which they belong, the next three near the middle of the corresponding segments, and the last pair near the posterior margin of the last segment. The pleon is short, with the segments more or less consolidated, and the pleopods are of the normal number and form. The “ operculum” is not formed as in the Idoteide and Arcturide of the uropods, but is nothing more than the enlarged and thickened first pair of pleopods, the greater part of it being formed of the external lamella, while the uropods have an entirely different and peculiar structure. They are biramous, and con- sist'on each side of a more or less elongated, flattened, basal segment, so articulated as to lie alongside the telson, and bearing at the apex a terminal plate, the inner ramus, in the same plane with itself, while, on its upper side near the base, stands a more or less perpendicular, oval plate, the outerramus. The telson is directed obliquely downward, and, with the uropods, forms a ciliated cup-like or flower-like termination of the cylindrical body, whence the name Anthura, from the Greek aos, a flower, and odpd, a tail. The structure of the mouth in this family has been investigated by Prof. J. C. Schiddte, to whose original papers in the Naturhistorisk Tidsskrift I have not had access. The paper on Anthura is translated and partly condensed in the Annals and Magazine of Natural History, | This family is represented within our limits by three species belong- 398 REPORT OF COMMISSIONER OF FISH AND FISHERIES. where that author states that “next the Cymothoide, though as a type of a separate family, the genus Anthura must be placed.” The species of this family may be at once recognized by the peculiar cup-like termination of the body. This cup or “flower” is formed by the telson below, and the uropods at the sides and above; the outer rami of the latter organs being placed nearly vertically, and approach- ing each other on the median line above, where, however, the “flower” is more or less imperfect. Our three genera may be distinguished as follows: First five segments of pleon consolidated above, Anthura (p. 104) ; segments of pleon distinct, antenne and antennul subequal, Paranthura (p. 108); segments of pleon distinct, antennule greatly enlarged in th male, Ptilanthura (p. 111). y Anthura Leach. Anthura Leach, Ed. Encye., vol. vii, p. “404” (Am. ed., p. 243), “181314.” Antennule and antennze short, subequal; thoracic segments not separated by constrictions; pleon with the five anterior segments con- solidated above and resembling the last thoracic segment. Our species of Anthura appears to agree in all generic characters with A. gracilis Leach upon which the genus was founded. In A. polita, how- ever, the consolidated portion of the pleon is seen at the lower part of the sides to be composed of five consolidated segments, and bears the normal number of pairs of pleopods, while Bate and Westwood * say that “the four anterior segments are soldered closely together” in A. gracilis, and that “the pleopoda consist of, at least, four pairs of oval plates, strongly ciliated, on each side of the ventral surface of the basal seg- ments of the tail” They had not, however, fresh specimens of the spe- cies, which is evidently closely related to ours. The ineubatory pouch of the females in the genus is confined to the third, fourth, and fifth segments, and is composed of three pairs of Jamellz, which overlap from behind forward, while the anterior margins of the first pair are united to the anterior part of the third segment. Anthura polita Stimpson. ? Anthura gracilis Dekay, Zool. New York, Crust., p. 44, pl. ix, fig. 34, 1844 (not of Montagu and Leach). Anthura polita Stimpson, Proc. Acad. Nat. Sci. Phil., vol. vii, p. 393, 1856. Harger, Proc. U. 8. Nat. Mus., 1879, vol. ii, p. 162, 1879. Anthura brunnea Harger, This Report, part i, p. 572 (278), 1874. Verrill, This Report, part i, p. 426 (182), 1874. PLATE XI, Fias. 68 and 69. This species is distinguished among its allies on our coast by the nearly complete union of the basal segments of the pleon, which have together the appearance of an eighth thoracic segment. The cup or “flower” at the end of the body serves to distinguish it from other Isopoda. * British Sessile-Eyed Crustacea, pp. 157 and 160, — MARINE ISOPODA OF NEW ENGLAND, ETC. 399 The body is smooth, shining and flattened above and broadly keeled in the males below. The head is a little broader than long, deeply ex- cavated on each side of the front for the bases of the antennule, and produced at the sides. The eyes are small and lateral but distinct, and are placed on the outer side of the anterior prolongations of the head, about on a line with the bases of the antennule. They are too indistinct in the figure, and the eye was even omitted on the right side by the en- graver. The antennul (pl. XI, fig. 68 a) consist of a tapering three- jointed peduncle and avery short flagellum. The first peduncular seg- ment is the largest, and is flattened above and on the inner side; the second segment is smaller, cylindrical, and provided with a comb of hair- like sete along its outer side; the third is smaller and shorter than the second; the flagellum consists of a single very small segment, with indications of a rudimentary second segment at the end, where it is also tipped with setz. The antenne (pl. XI, fig. 68d) consist of a five-jointed peduncle, and a short flagellum much like that of the antennule. The basal segment of the peduncle is short; the second segment is the largest and is of peculiar shape, being excavated on the outer side to adapt it to the antennula, which lies in the groove thus formed, while the segment is bent upward and inward, and exposes a slender triangu- lar area with the point backward, between, and on a level with, the an- tennule; the next three segments are sub-cylindrical and diminish in _ size, and are followed by one or two small flagellar segments tipped with | sete. The maxillipeds (pl. XI, fig. 69a) are thick and strong, and are com- posed of a basal quadrate segment, a little longer than broad, with its proximal external angle elided for the short, sub-triangular external : lamella, and bearing two segments representing the palpus. Of these . SE —— segments the first is but little smaller than the basal segment and is sub-quadrate, tapering a little at the sides beyond the middle. The terminal segment is straight at its articulation with the preceding, and nearly so along the inner side, then rounded in the remainder of the out- line. The segments of the palpus are finely ciliated along their margins, except along the external margin of the first segment, where the cilia- tion nearly disappears; they are also provided with coarse sete, a few of which occur on the maxilliped, near the outer distalangle. The inner maxilla (pl. XI, figs, 69b and b’) is rather robust, and terminated by astrong tooth or spine, below which, on the inner side, is a row of smaller curved teeth. The mandibles are terminated by a horny tooth, below which is a serrulated lobe; the mandibular palpus is robust; the second segment much the longest and provided with stout setz; the last segment with a comb of rather short sete. The maxillipeds are of much firmer texture than the other parts of the mouth. The first thoracic segment is the longest, and is closely adapted to the head behind so as to allow but little motion. The second segment is shorter but somewhat broader than the first, and is rather freely — a a he ee “ 400 REPORT OF COMMISSIONER OF FISH AND FISHERIES. articulated with it, and still more freely with the third; it is car- inated below, but its articulations are much less free than in the next genus. The third, fourth and fifth segments are each about the length of the second; the sixth and seventh are progressively shorter. The first pair of legs (pl. XI, fig. 68) are quite robust and have but little free- dom of motion, being directed forward under the head and hardly capa- ble of further lateral extension than is shown in the figure of the animal. The basis and ischium are large and articulated so as to form a curve, bringing the legs forward; the merus is short; the carpus is triangular and extends along the side of the thickened propodus for about half its length, projecting like a tooth at the end; the propodus is ovate, much thickened and armed with a tooth near the middle of the palmar margin, along which it is ciliated, as is also the carpus; the dactylus is short and stout and tipped with a slender, curved, chitinous claw about as long as the dactylus itself. The figure (pl. XI, fig. 68 c) represents the inner surface of the leg, the merus being much less conspicuous on the outer side. The second and third pairs of legs are nearly alike and much more slender than the first pair. Oneof the third pair is represented on plate XI, fig. 68d. In both these pairs of legs the carpus is small and triangular and wedged in between the merus and propodus, which meet: above; the merus is a little larger in the second than in the third pair, and in both pairs it is provided with a few sete at the upper distal angle and along the opposite or palmar side, where the carpus is also armed with set; the dactylus bears a few very short set. The re- maining pairs of legs are rather more slender than the second and third, and the merus is separated from the propodus above by the carpus, which is, however, short. These legs are somewhat hairy, like the pre- ceding pairs. The anterior part of the pleon (pl. XI, fig. 68 g), consisting of the first. five segments consolidated, appears much like an eighth thoraci¢ seg- ment a little longer than the seventh; traces of the sutures between the: segments can be seen at the sides. The last segment is distinctly articulated, a little elevated dorsally, where it is also somewhat hairy ;; at the lower part of the sides it is covered by a slightly projecting lobe of the preceding segment, which extends over the proximal part of the basal segment of the uropods. Distally the terminal segment is depressed at a steep angle, and is in the form of a plate, ovate and ciliated at and near the tip, where it is obtuse; the sides are nearly parallel, and it is surpassed by the uropods, which consist, on each side, of a large basal segment, carinated on the outer side and toothed at the articulation with the outer ramus, obliquely truncated at the end, where it bears a short, obtusely-triangular, ciliated, inner ramus, or lamella, in the same plane as the basal segment. The outer ramus, or lamella, forms nearly a right angle with the basal segment, and stands upon its superior outer margin. This ramus is elongate reniform in out- line, being notched below for the tooth on the basal segment, and is. | : | MARINE ISOPODA OF NEW ENGLAND, ETC. 401 ciliated along its free superior margin. The first pair of pleopods (pl. XI, fig. 68e) are composed on each side of a short, quadrate basal segment supporting two rami, of which the outer is, like the basal seg- ment, of firm texture, and acts as an operculum; in shape it is semi- oval, with the inner margin nearly straight, and is ciliated distally, and along the outer margin. The inner ramus is much smaller than the outer and of delicate texture, and, in the natural position, is covered and concealed by the outer ramus; it is slender, with nearly parallel sides, rounded at the tip, and not ciliated. In the males the second pair of pleopods (pl. XI, fig. 68 /) bears, near the middle of the inner margin of the inner ramus, a slender stylet, slightly surpassing the lamella to which it is attached. The lamelle forming the incubatory pouch of the females are of con- siderable antero-posterior dimensions, and the posterior widely overlap the anterior ones, while the anterior border of the first lamella is united with the third thoracic segment, to which the lamella belongs. Length 15-18™"; breadth 1.8-2™™. The color is brownish above, mottled with yellowish or honey eolor, lighter underneath. This species was described as new by the present author in the first part of this report under the name A. brunnea, but there appears to be no sufficient reason for regarding it as distinct from Dr. Stimp- son’s A. polita. It is apparently closely related to A. gracilis Leach, although sufficiently distinct according to Bate and Westwood’s* de- scription and figures. Those authors, however, seem to have had but very poor and imperfect material on which to base their work. They figure and describe the telson and uropods as truncated and crenulated, and Montagu;,t in his original description of the species, says: that “the body is terminated by five large caudal appendages truncated. at their -ends.” ‘Kréyer’st deseriptions and figures of A. carinata:approach much more closely to the-present species. His figure of the antennula considerably resembles. ours, but-in his description he gives as the relative lengths of the four segments composing it 11, 4, 3,5. In our species the last or flagellar segment is much the ‘shortest, as may be seen by the figure, ‘plate XI, fig. 68a. He further speaks of the telson as crenulated, while it is entire in A. polita, and his figure (Voy. en Seand., pl. 27, fig. 3.n‘) shows no tooth-like projection or angle on the basal segment of ‘the uropods, as seen in a lateral view, and the corresponding margin.of the outer or superior plate is destitute of the notch shown in the lateral view of these organs on plate XI, fig. 68g. The inner ramus or lamella of the first pair of pleopods is also figured as much larger and more expanded distally than in our species, for which see plate XI, fig. 68 e. Unfortunately I have had no European specimens for comparison. * Brit. Sess. Crust., vol. ii, p. 160, 1868. tTrans. Linn. Soce., vol. ix, p. 103, pl. v, f. 6, 1808. t Naturhist. Tidssk., II, B. ii, p. 402, and Voy. en Scand., Crust., pl. xxvii, fig. 3 a-o, 1849, 26 F 402 REPORT OF COMMISSIONER OF FISH AND FISHERIES. This species was described by Dr. Stimpson from specimens taken at Norfolk, Va., and has since been collected by Professors Smith and Ver- — rill at Great Egg Harbor!, N. J., in 14 fathoms shells and mud; by the U. S. Fish Commission in Long Island Sound!, especially at Noank Harbor !, among eel-grass (Zostera marina) and mud; off Block Island! in 17 to 194 fathoms sand, mud, and stones; at Vineyard Sound!, atlow water and in sand, and in 1878 at Gloucester !, Mass., in mud and among alge. Specimens examined. Gets oa a ye 3 Locality 8 Bottom. yen va Receivedfrom— 25 ped ei RB Ba a FA A”? Great Egg Harbor, N.J. 14 | Shells ani mud....| Apr. —, 1871 | Smith & Verrill].-..-.- Ale. 2077 | Noank Harbor, Gonnts-lst48-3 Eel-grass.....----- Aug. 28, 1874| U.S.FishCom.| 2 | Alc. DOTS Sie dO Meese telece cess lee eeesce Mud Baa eel-grass. rene 29,1874 |....d0 .-.c:-500 2 | Ale. 2079))|5-- dO Sera sess Seek ioalaae coe Wal A shesacseacas . 28, 1874;|...d0 Jouceeky 2 | Alc. 2080 Vineyard Sound .-..... GSW. sand c.ces scenes Sort 8, 189i |22 dol sese eee 2 | Alc. Squan Estuary, Glou- |.....-.-- Mud cisco seata sae — —, 1878 |....do ......... 2 | Alc. cester, Mass. Gloucester, Mass ......|..--.--. Mud and algaw..... — —,1878|....do ........- 1 | Alc. Paranthura Bate and Westwood. Paranthura Bate and Westwood, Brit. Sess. Crust., vol. ii, p. 163, 1866. Pleon articulated, composed of six segments; thorax deeply con- stricted at each end of the second segment; antennulz and antennz subequal; palpus of maxillipeds three-jointed; inner maxille acicular. The first character given above is the only one given by Bate and West- wood, who, however, mention that the pleon bears the normal number of pleopods; a character that would not distinguish our species from the other genera. The distinctly articulated flagellum of the antennule is provided with a partial whorl of bristles, which, however, forms only the most rudimentary approach toward the structure of those organs in the males of the following genus. The segmentation of the pleon is indis- tinct in the dorsal region, but is apparent at the sides when seen from above, and the pleon does not at all resemble an additional thoracic segment as in Anthura. Both pairs of antenne are provided in our species with a distinctly articulated flagellum, and are of nearly equal length. Paranthura brachiata Harger (Stimpson). Anthura brachiata Stimpson, Mar. Iny. G. Manan, p. 43, 1853. Verrill, Am. Jour. Sci., III, vol. v, p. 101, 1873; ibid., vol. vii, pp. 42, 411, 502, 1874; Proc. Am. Assoe., 1873, pp. 350, 357, 1874; This Report, parti, p. 511 (217), 1874. Whiteaves, Am. Jour. Sci., III, vol. vii, p. 213, 1874; Further Deep-sea Dredging, Gulf of St. Lawrence, p. 15, ‘‘1874.” Harger, This Report, part i, p. 573 (279), 1874. Smith and Harger, Trans. Conn. Acad., vol. iii, p. 16, 1874. Paranthura brachiata Harger, Proc. U. S. Nat. Mus., 1879, vol. ii, p. 162, 1879. sl ll a = . an MARINE ISOPODA OF NEW ENGLAND, ETC. 403 PLATE XI, Fie. 70. The deep constrictions, by which the second thoracic segment is sepa- rated from the first and third, serve to distinguish this species from the allied forms on our coast, and the “ flower” at the end of the pleon dis- tinguishes it from other Tyas. Body moniliform, with evident segments; head narrower than, and about half as long as, the first thoracic segment, flattened and quadrate above, with a groove behind a raised anterior border, wedge-shaped below, deeply emarginate on each side of the projecting front above for the bases of the antennule; eyes lateral, not conspicuous, extending behind the emarginations. Antennule (pl. XI, fig. 70a) with the first segment large but longer than broad, flattened above; second and third segments cylindrical; flagellum of twelve or more segments in adult specimens, with the first segment short, second twice as long and the longest segment of the flagellum, which tapers from the second segment and bears on the distal end of each segment an imperfect whorl of hairs. The antenne (pl. XI, fig. 70 b) slightly surpass the antennule. They have the first segment short; the second flattened on the inner side, where it is usually in contact with its fellow of the opposite side, and excavated on the outer side above to accommodate the basal segment of the anten- nule; the third segment is short; the fourth and fifth longer and cylin- drical. The flagellum consists of about twelve segments, tapers from the base, and is somewhat hairy. Both the antenne and antennule are a little less developed and have one or two less segments in the females. The maxillipeds (pl. XI, fig. 70 ¢) are elongated, with a short, oval external lamella, and a two-jointed palpus. The large basal seg- ment of the maxilliped projects on the inner side nearly to the end of the first segment of the palpus. The palpus has its segments of about equal length and provided with a few scattered bristles. The inner maxille (pl. XI, figs. 70d and d’) are evident at the tip in an under view of the head; they are elongate and acicular, and minutely and sharply retro-serrate toward the tip. The three-jointed palpus of the mandibles is also conspicuous below; all three of its segments are short, and the last, which lies ordinarily between the bases of the an- tenn, is flattened, oval, and provided with the usual comb of setze. The thorax is somewhat flattened above, carinate anteriorly below, and has the last segment much the shortest. The first segment is wider than the head and about twice its length, and is more closely united with it than are any of the thoracic segments with each other; it is strongly carinate below, especially on its anterior part, where the carina ends in a prominent tubercle; a much more slender carina bounds the flattened dorsal portion laterally. The second segment is separated from the first by a deep constriction, and is articulated so as to allow considerable motion, especially in a vertical plane; its antero-lateral angles are prominent in the form of low, rounded tubercles, and be- 404 REPORT OF COMMISSIONER OF FISH AND FISHERIES. tween them are two less evident tubercles on the front margin of the segment; the dorsal surface tapers behind, and is bounded laterally by carinee; below, the segment is wedge-shaped, but not carinated ; behind, it is separated from the third segment by a constriction not quite as pronounced as that in front. ‘The third segment presents two rather more evident median tubercles in front on the dorsal surface, which is defined laterally by carinz, fading away at about the middle of the segment; below, it is wedge-shaped and carinate in the males, but membranous along the median line in the females, as are the remaining segments more widely in that sex. In the males they are hard and chitinous throughout, rounded and scarcely wedge-shaped. The fourth segment is slightly longer than any of the others, and bears, near the anterior end of its dorsal surface, an oval depression with slight elongated elevations at each side. A similar structure occurs on the fifth and sixth segments, which are of decreasing length. The seventh is much the shortest thoracic segment, not being longer on the median line than the head; it is somewhat produced laterally. The first pair of legs (pl. XI, fig. 70 e) are not as stout as in Anthura polita, and are more flexible; the carpus is the shortest segment, and is triangular, broader than long; the preceding segment, or merus, - shows but little in an external view, but is more evident in an inner view, as shown in the figure, and is much broader than long; the pro- podus is much swollen proximally on its anterior or upper side; im- mediately in front of the end of the carpus it bears a stout tooth; the dactylus is strong, and tipped with a curved claw. In the second and third pairs of legs the carpus is triangular, but in the posterior pairs it is more elongated so as to distinctly separate the merus from the . propodus. The pleon is short, the telson triangular, acute at the apex. Uropods with the basal segment strongly carinate externally, terminal plate acutely triangular, proximal superior plate oval, curved and attached by its side, nearly meeting its fellow of the opposite side above. First pair of pleopods (pl. XI, fig. 707) with the external ramus semi-oval; internal ramus less firm in texture, ligulate, ciliated distally. Second pair of pleopods in the males (pl. XI, fig. 70g) furnished with a slender stylet articulated at about the middle of the inner, posterior, lamella, ind extending beyond its end. Both the lamelle are crossed by a trans- verse suture just beyond their middle, at the point where the stylet is ittached to the inner one. Length 28"; breadth 2.2"; females about one-third smaller. The olor is usually light yellowish brown, or sometimes somewhat darker, but not as pronounced as in the other members of the family, and nearly che same throughout. From P. norvegica G. O. Sars* our species is distinguished by the eyes, which, though inconspicuous, are present. It lacks the tubercle de- * Chr, Vid. Selsk. Forh., 1872, p. 88, 1873. es = ~F rr 405 scribed and figured by Heller on the head of P. arctica,t and the flagel- lar segments of both pairs of antenne distinguish it from P. costana Bate and Westwood.t This species was dredged by Dr. Stimpson ‘on a shelly and some- what muddy bottom in twenty fathoms off the northern point of Duck Island,” Bay of Fundy. It is rare south of Cape Cod, but was taken in Vineyard Sound! by the Fish Commission in 1871; alsoonSt. George’s Bank!, in 110 fathoms, mud and sand; Gulf of Maine!, down to 115 fathoms; Bay of Fundy!, down to 80 fathoms on muddy, shelly, and sandy bottoms; and off Nova Scotia!, 59 fathoms, pebbles, sand and rocks, and at other localities as detailed below. It was dredged by Mr. Whiteaves in 200 fathoms in the Gulf of Saint Lawrence, between Anticosti and the mainland of Gaspé. MARINE ISOPODA OF NEW ENGLAND, ETC. Specimens examined. ae : Z When col rl : D ) Locality. g Bottom. leat Received from— ad 5 iph 3 Ae a Fy a” Mano vonde oun 2.4225) |ic sata desst was ee cee de= acs — —,1871| U.S.FishCom.|...-... Ale. 2081 | Gulfof Maine, east from | 115 | Gravel........-.- —— —,1877| -..do.-....... 2 | Alc. Cape Ann 140 miles. Gulf of Maine, southeast 53 Mud and stones.| —— —, 1878 |....do .......-. 1 | Alo. 2 east from Cape Ann 13 miles. 2082 | Gulf of Maine, near 82 Rocks and bar- | —— —, 1877|.--.do.......-. 2 | Alc. Brown's Bank. nacles. 1365 | George’s Bank ...-...-.. 110 | Brown mud....-. — —,1872 reckons and 2 | Alo. ooke. 2083 | Gulf of Maine, off Ports- | 80-92 | Soft mud... .... —— —,1874| U.S.FishCom.| 3 | Alo. mouth 22 to 28 miles. 2084 | Gulf of Maine ...--...-.. 65 Mud, pend, and | —— —,1874|.-...do ......... 2 | Alc. gravel. 2087 | Casco Bay, 20 miles 68 UG ef ee Pa es Anigs IZ $878, |s22 Ot nce cce 1 | Alo. southeast of Cape Elizabeth. 2088 | Gulf of Maine, 27 miles DO Wee aeee cccaee asics Aug. 26, 1878, |.--.do ..... 1 | Alo. off Portland. OPP A525 7) a ore [ore geht nal See, fa —— —,1873]....do......... 10 | Alc. 2086 | Gulf of Maine, 17 miles 72 Brown mud...-- — —, 1873 |..-.do......... 3 | Alc. southeast of Monhegan Island. Pe an TDORE AMO 22s: = s|ewaseeo.[ecds-nesseeeacane —— —,1870| A. E. Verrill..| 1 | Alc. 2097 |.-.--. GivereamGuesaraenosmclidecwa ssl Saeeernaeee cartes. — —, 1872] U.S. sicaiias 4 | Alc. 2091 | Bay of Fundy, between 60 WG. sto —t a. oe = Aug. 16, 1872|....do . 8 | Alc. Head Harbor and Wolves. 2092 | Off Head Harbor ......-. 75-80 | Sand and shells. —— —,1872|..-.do......... 8 | Alc. 2093 | Bay e ‘ecard 6 Song Ee Pi 2" eA ae 4 oe ie es — —, 1872 dow oanones 1 | Ale. Bie asa ae Us cs = aaa neawes oo ac Ci ha Shee le ee Aug. 16, 1872 |. : 00! Jisaranae 1 | Alc. 2096 | Bay of DTC Ea ee ee |e oe ee a |———_ —, 1870 A. E. Verrill..| 3. | Ale. Menan, New Bruns- wick. 2098 | Southeast from Cape | 56-59 | Sand, gravel,and|—— —,1877| U.S.FishCom.| 2 | Ale. Sable 18 to 22 miles. stones. Ptilanthura Harger. Ptilanthura Harger, Am. Jour. Sci., III, vol. xv, p. 376, 1878. Antennule with the flagellum remarkably developed in the male, multiarticulate; second and succeeding antennular segments provided t Denkschrift, Acad. Wiss. Wien., B. xxxv, p. [14] 38, pl. iv, figs. 9-12, 1875. t Brit. Sess. Crust., vol. ii, p. 165, 1866. 406 REPORT OF COMMISSIONER OF FISH AND FISHERIES. with an incomplete, very dense whorl of fine slender hairs; pleon seg- mented, elongated; palpus of maxillipeds one-jointed. The most important character of this genus is doubtless found in the structure of the antennule in the male sex. In the females the anten- nul are small, and the flagellum consists of a few slender rapidly tapering segments. They thus bear considerable resemblance to young specimens of Anthura polita, and being collected with them, were at first mistaken for them. They are distinguished by the larger and more conspicuous eyes, and by the more elongated and distinctly segmented pleon. In the presence of eyes our species differs from a form described by G. O. Sars, Paranthura tenuis, from near Stavanger, Norway, in which the males have a well-developed, eight-jointed and densely hairy or setiferous flagellum on the antennule. Ptilanthura tenuis Harger. Pitilanthura tenuis Harger, Am. Jour. Sci., III, vol. xv, p. 377, 1878; Proc. U.S. Nat. Mus., 1879, vol. ii, p. 162, 1879. Puates XI and XII, Fires. 71-74. Males of this species are at once recognized by the greatly developed antennule, resembling miniature bottle-brushes; females may be dis- tinguished from the young of the other species by the conspicuous eyes; they are much smaller than the adults of the other species. The body is smooth, flattened above, narrow at the middle, broadest at the base of the pleon. Head broader than the first thoracic segment and nearly as long, on the median line; longer than broad, narrowing to a point in front and much less acutely behind. The eyes are promi- nent, black, situated within the margin of the head and visible both above and below. The antennule in the males (pl. XII, fig. 74a), when reflexed, attain the third thoracic segment; the first segment is large, but not longer than the second; the third is shorter than the second and followed by a short, subtriangular segment, which must be regarded as the first segment of the flagellum, although resembling the last peduncular segment much more than it does the succeeding or second flagellar segment; this segment is small at its base, but expands rapidly above and below and on the side which is next the body in the ordinary reflexed position of the antennula, and on these sides it bears, at its dis- tal end, a fine and dense fringe of long slender hairs, which attain, when appressed, about the fifth following segment. Similar segments, to the number, in some specimens, of eighteen or twenty follow, forming an organ resembling a minute bottle brush or plume, whence the generic name. On one side, however, of the organ, which corresponds nearly with the outer or anterior side, according as the antennula is more or less reflexed, the whorl of hairs is interrupted. In the females (pl. XI, fig. 73) the antennule are shorter than the antenne, with a short flagel- lum consisting of a small basal segment and a minute terminal one tipped with a few sete. The antenne (pl. XII, fig. 740) are short, OO ' - MARINE ISOPODA OF NEW ENGLAND, ETC. A407 _ differing little in the sexes, hardly surpassing the peduncle of the anten- . - nule in the males, with a short three or four jointed flagellum bear- ing a few hairs near the tip. The maxillipeds (pl. XI, fig. 71b) have a quadrate basal segment, somewhat emarginate externally for the subtriangular external lamella, and bearing a single suboval terminal segment, or palpus, somewhat truncate and ciliated at the tip. The inner maxille (pl. XI, fig. 71c) are five-toothed, one tooth being strong and terminal and the other four lateral. The mandibles bear a single- jointed palpus. ' ‘The thoracic segments are subequal in length except the last, which is but little over half as long as the others, though broader behind than any of them. They are slightly narrower than the head and margined laterally with a somewhat raised ridge. The third, fourth, and fifth have an elongate oval depression on the median line near the anterior margin. The first pair of legs (pl. XI, fig. 72) have the segments well separated, the carpus nearly equilaterally triangular, the propodus moderately thick- ened, and the dactylus strong and tipped with a stout claw; the carpus and propodus are bristly on their palmar margins. The remaining pairs of legs are slender and nearly equal in size. The pleon is about as long to the tip as the last three thoracic seg- ments. The first five segments are consolidated along the dorsum, but distinct at the sides. Each segment rises into a low broad tubercle on each side of the median line. The last segment is about as long as the preceding five, and is elongate-ovate, and obtusely pointed behind. The basal plate of the uropods is about half as long as the telson; the terminal or inner lamella is triangular-ovate, and about equals the telson. The proximal or superior lamella is narrowly semi-ovate, with an emargination on the upper side near the tip. The first pair of pleopods (pl. XI, fig. 71d) are shorter than the abdomen, and have the outer plate semi-obovate and the inner shorter, with nearly parallel sides. The second pair of pleopods (pl. XI, fig. 7le) bear, in the males, a slender straight stylet, articulated below the middle of the inner lamella and slightly surpassing it. The outer lamella is imperfectly articulated near the middle. Length 11""; breadth 0.9""; females about one-third smaller; color brownish and more or less mottled above, lighter beneath, margined with translucent at the sides, extending on the sides of the head as far as the eyes. This species is rare on the coast. It has been taken by the United States Fish Commission, on muddy bottom, in Noank Harbor, Long Island Sound!; off Watch Hill!, R. I., in 18 fathoms, sand; and off Block Island!, in 17 to 194 fathoms, sand, mud, and stones; at Waquoit, Vineyard Sound!, in sand, at low water, September 8, 1871; in Casco Bay!, sand and mud, from 9 fathoms, in 1873, and by Prof. A. E. Verrill, at Grand Menan, in the Bay of Fundy! in 1870. It is nearly related to and doubtless congeneric with Paranthura A408 REPORT OF COMMISSIONER OF FISH AND FISITDRIES. tenuis G. O. Sars,* but is at once distinguished by the presence of eyes, from which character, as distinctive, the name P. oculata might be applied to our species if a new trivial name should be thought necessary. Specimens examined. Speci u a mens. ® . | When col- P Dry. E Locality. E Bottom. lected, Receivedfrom—!___| ag 5 é No.| Sex. 2099 | Noank Harbor, Conn]. .-...-.. 2 U keer — —,1874| U.S.FishCom |} 1] o | Ale. BMPMILE Cdote linet sisi irae l eta Mts seeks kkoe se Peas ae Pee eee 1| 9 | Ale. 2100 | Off Watch Hill, R.I.] 18 San@eevass wee aac July 31, cee g PRG gee De Qh rates 2105 | Off Block Island .... 17-194 | Sand, mud, and | —— —,.1874]|.-..do...-.----| 1] 2 | Ale. stones. 2103 Li aaa Sound, } L. w. | Sand...-........ Sept. 8) 187i). --:dos Warsdog snorydryjo snosmojoy epoormere eypoovydsog iidiipeakss tsa *~ BIUHTA wposoTy ? WAIOSINO 28 F a caeaaaataa eae ee —— ——————————<—_ = ie 7 nt Sa eee a a , , 027 ‘pau ‘ssvi3-[ooy seen seesiscvolseeesisoss|seesiseasieeosboeesisons | eens 1 sees 1 j ++ sees Lig 0 ser eeeoeseweseeeuses saenaes ejjod simnqjuy ?WalgnHINy ce OF AST OD SME V9 Teal Suen] ene| fore [oede|eucltegelaneslae a> [te ebl ange betel t zee] | Weluaeal, to [lee Leekgel eceed] en cecseinnes axon aRkane swat EegnTieh ee I “ysy-o[y Wo orptseacg [oen-|-eee|eeee [eee |eree|eeee|eeee fer ee|eeee|ereeleree|enee] po [esee|eceelseee|ecee|ere-|enneee|eeeene|eres see seeeseceeeeeeeesee + -@pUNUl BfIOOION | ? WAIOHLOWAD Z Be eeerores poo'ams wo Cee ee ep foe ae toler eleeeedd Pecrclesesleoesle=eghiceelesselieecltcoallCe: (IGE. TC acoseersnetvexcatrsraner ela tare [s 1 wallow B Taser oag ac ooh nese se (tela c dace eal focal touslngealsezal ates toecl del ad eq ffs lee | le aes (acme eae pasacecsessecaressezee- naa EET i :WaINVIOUID a ‘JoquIy} pos1eumqnes uy Suplog | + | + fon "|r| aS HLYeatP fam] enl Gemeal | aucel ete ete | aca | Ved Sama Ba 1 OL. (Os! apaasesekerseetoce *****gUIMLIOUST BLOuUYT e: : HW OUYONAT'T fo) ‘029 ‘s[ood-opry ‘exo |rees|sees|seee [eee e|see cfr esse e|eeee[eeee|eeeeleees ol kcrcestes ok [ebehg lee lesseesleeaeneeeeeranse wnyeUeprpenb wuoreqdg = : WaINONWHAg A ‘o7 ‘powulng UO |***-|""*" op |ovee[enee|==e- af oa kee g. [Rett birer|tees| desl tnarlssaelasnsiazes OM oe a a Ca eyeuUEIs STTOU TY B iwaIUnLory = gu10}30q Appa puw Ayooy, [ores |o0r-|trreferesfit staf 1 toh slieteol ils | 5| ali elie [gana ee AB eee OF: -2| Broce tapsenctorescssssscsesseKs snsoyuou = Fe A eB i a bet lel Bed EA relied eed AD Ip floater Coen | eS ae a ee = ‘o2p ‘BTTOUS ‘Ssuas-[omy |o<<«|oe iron c[om efor nfm ee[ewnelnneelewe steers et cnneiacne bfeeeet ple [eter isese L 0 oer eeeewencccnnecncnes STULIOJTTY BMOSyOL IG : "ponuyyu0j—w aIaLOgT 5 PEI Slele sie slelsle/Sleleleieielel & | & a 3 s|a|3/ 6 m, 3 E “+ g Bebe lili oo 8 = e SH 435 “2eT oSed oste cog §=‘oovy.ms “fe f9r0ys “s £197BM AOT SOPIUSIS “a ‘ SUOT yey UL OATS Ore SyYdop ONT, “Pes SI 4T YORA Jopun mae oT} 98 M990 07 SIOqINe 1oqY0 Aq pres St Soroeds vB 4vqy SeZOUep -+ UsI8 OFF, -pouva Agr[va0] OY} Ye PUNO; Uo9q SvT{ Sofoods B 4YVq} YMOMIOZEIS OG} LOF LOYJNB oY} JO AyyIqisuodsea oy} ATUS1s 07 posn SI JULOd UOTyeUIE[OXe UL O[qv} OAOGE OY} U[—"ALON ‘Avg s}osupoussepL Jo S}TUMT] ON UTGITAL ATQO1I}8 Jou o10yoI0 TY pus ‘uy odey jo qJA0U ‘tUeNDsTUTW 4B Po}oT]OO Svar andns nY9Yy90}da'T 9 1eQ ‘oospouvag Ug Ivou ‘ULedDGO OYLOV OY} UL 1000 O}F PIES ST PUL Bog OCLIPY OY} UL OSTE pUNoF SI UWNLOUBY DLLOWWT g “RIG MINOD YS 0} OSTR SpudzxXo YSOINpOU vozopLUliy’ y “PUL[IIT PUR PULTWIIIH WoIAdyod ‘OPNAYLT YILOU oY WLOIF SIG AG POqLIOSOP SUA 1}87G04 VI}OPT g “Bog UBIdseD OY} ULIN990 0} Pres WAP ST puL ‘SvEg Youl_ OG} ‘OYVIUpy oy} ‘WeoUBLIOPI PET Ot} ‘OVA Ol} 0} OSTV SPU9}X9 PDL0L2 POOPT s a “4g JO JID OY} UL SMLONYe 0ZZ MoI SoavOTIM “TC “IL Aq pourezqo sea ynq ‘syrorT[ IMO UTGFTAL Apung jo Leg oy} ut sur0yzeF 09 Ut ATUO posporp useq seq nndhy sisdowuwnyy 1 MARINE ISOPODA OF NEW ENGLAND, ETC. Sepeate Crs (Py 08 Gv a Vas IAN Fas st) ISR |e edb |= Vey | | Sa Pea sy px PSs "Sa ee STN EN 11) .°801)09 DUpPWsSY BUOULY,, |*~-"|"-7 |r af [ates [Le o= ape ssh be aids moe eae Bas eee eae | 0% 0g. \tcrtress assess wes eeneees wunyy RRR ToO moe anya (cc. les aewomince s\n 2 aiaerc ee ago ai ae l wome|eoec|ecna|scwnlsoee[sene|ooca|-secwslsccnaaiocesconenscacccuccesss: o xUdUr FROIONT OMA DDLLIAG |= ote een ee eee eee eee ea atl taee Fe ON SS OCIS I Dat SB aa gP Ope [er se ae ah ek ee, BLOC ROaT WHBIs- 100 PUB Gay, (=== |p aco" siroaa| cen | eos cease a slp cen coos POMC poealat Mc cc les clues Ir 0 segs Fae "= BIOOLSTR BlpoTo0ydory “BOLO PUB BSL Y. | = Naf irs aleo sale eats hee sine eae coal ll ame | Wale: eee ciee 1! 0 Fes seatseseea ce os os Soro wera spent ?WaIvNviL “qs UO orpIsvavd Sunod ‘pnur pur syooy sace|ecwcloccclocnelaces| 2 jennal 1 | I Fe fee S| 2 | a cd Fae 9 2k 022 Or seen emcees erensecccensnens=- BUTI GITVEUL) : 2 CUHLYNYD APOME UM AUER lower lok les sie onl eel ee tk I 1 tee "ire te OE 0 veoapecesoosencecssre’*” STAUS} SINGIUE TY *sui0}j0q Appuu pus ‘Ayjoys ‘A007 ees ees Oe ee oa j 1 l I wwwelewne i eer ee ee SIL 0z soeccecccccccuvcsoos Mau OBId BINIQUBIEG Se — . ‘ ‘ . . ‘ . . . . . . EE ———— 436 REPORT OF COMMISSIONER OF FISH AND FISHERIES. LIST OF AUTHORITIES. The present list includes only such works and articles, relating wholly or in part to Crustacea, as have been quoted, or otherwise used, in the preparation of the preceding paper, and is chiefly intended to aid in consultation of the authorities quoted. A fewof the titles are necessa- rily given at second hand, as indicated by quotation marks in the list. The references to these works occurring throughout the article are also inclosed in quotation marks, usually with an accompanying mention of the author from whom they are taken. In all other cases the references have been made directly from the works quoted. A considerable num- ber of authorities have not been referred to, and are omitted from the list, because at present inaccessible, and, for many of the most import- ant works that I have been able to consult, I am indebted to the liber- ality of Professor 8S. I. Smith, who has given me the free use of his library and afforded other material aid in the preparation of the article. Ihave also had free access to the libraries of Professors Verrill, Marsh and Dana. In this list, as throughout the article, the number of the series of various scientific publications is indicated by Roman numerals in cap- itals. As far as possible references have been made to the original paging, sometimes with that of the separata added in a parenthesis, and, in the following list, a parenthesis is used to denote that the paging is, or is supposed to be, that of the separata. Agassiz, Alexander. Letter to C. P. Patterson, Superintendent Coast Survey, on the dredging operations of the U. 8. Coast Survey steamer “Blake” during parts of January and February 1878. < Bulletinof the Museum of Comparative Magee: vol. v, pp. 1-9. Cambridge, 1878. Andrews, A. [Limnoriaterebrans attacking telegraph cable.] < Quarterly Journal of Microscopical Science, II, vol. xv, p. 332. London, 1875. Audouin, Jean Victor, and Edwards, Henri Milne. ‘‘ Résumé d’Entomologie, ou @Histoire naturelle des animaux articulés, complété par une iconographie de 48 planches. [2 vols.] Paris, 1828-29.” Audouin, Jean Victor, and Edwards, Henri Milne. Précis d’Entomologie ou d’His- toire naturelle des animaux articulés. Premiére division, Histoire naturelle des annélides, crustacés, arachnides et myriapodes, complété par une iconographie. [8vo, 70 pages, 48 plates.] Paris, 1829. Audouin, Jean Victor. Description de Egypte ou recueil des observations, et des recherches qui ont 6té faites en Egypte pendant l’expedition de ’armée Frangaise. Explication sommaire des planches de crustacés de ’Bgypte et de la Syrie. Pub- liées par J. C. Savigny. Histoire naturelle, tome i, pt. 4, pp. 77-98. Paris, ‘‘ 1830.” Bate, C. Spence. On the British Edriophthalma. < Report of the British Associa- tion for the Advaneement of Science, 1855, Reports on the state of science, pp. 18-62, pl. xii-xxii. London, 1856. Bate, C. Spence. On Praniza and Anceus and their affinity to each other. < An- nals and Magazine of Natural History, III, vol. ii, pp. 165-172, pl. vi-vii. Lon- don, Sept., 1858. Bate, C.Spence. Crustacea. [In] List of the British marine invertebrate fauna. By Robert McAndrew. < Report of the British Association for the Advancement of Scejence. 1860. Reports on state of science. pvp. 217-236. London, 1861. r) Se oS re eo. 7) — - —— , ee ee ae MARINE ISOPODA OF NEW ENGLAND, ETC. 437 Bate, C. Spence. Carcinological gleanings, No. ii. < Annals and Magazine of Na- tural History, III, vol. xvii, pp. 24-31, pl. ii. London, 1866. Bate, C. Spence, and Westwood, John Obadiah. A History of the British sessile- eyed Crustacea. [2 vols. 8vo.] London, 1861-1868. | Beneden. See Van Beneden. Nederland en zijne Kusten. [8vo., 100 pages, 2 plates.] Groningen, 1874. _ Bosc, Louis Augustin Guillaume. Histoire naturelle des Crustacés, contenant leur description et leurs meers; avec figures dessinées d’aprés nature. [12mo., vol. ii, 296 pages, 18 plates.] Paris, An x (1802). Buchholz, Reinhold. Zweite Deutsche Nordpolfahrt ‘‘in den Jahren 1869 und 1870, unter Fiihrung des Kapitiin Koldewey.” B. ii, Part viii, Crustaceen, pp. 262-399. Bos, Jan Ritzema. Bijdrage tot de kennis van de Crustacea hedriophthalmata van | pl. i-xv. Leipzig, 1874. Buchholz, Reinhold. Mittheilungen naturwiss. Vereins v. Neu-Vorpom. u Riigen, i, pp. 1-40. See Miinter, Julius. Bullar, John Follett. The generative organs of the parasitic Isopoda. < Journalof ; Anatomy and Physiology, vol. xi, pp. 118-123, pl.iv. London and Cambridge, 1876, Bullar, John Follett. Hermaphroditism among the parasitic Isopoda; reply to Mr. Moseley’s remarks on the generative organs of the parasitic Isopoda. < Annals and Magazine of Natural History, IV, vol. xix, pp. 254-256. London, 1877. Catta, J.D. Note sur quelques Crustacés erratiques. < Annales des Sciences natur- elles, Zoologie, VI, tome iii, pp. 1-33, pl. i-ii. Paris, 1876. Coldstream, John. On the structure and habits of the Limnoria terebrans, a minute crustaceous animal destructive to marine wooden erections, as piers, ete. < Edin- burgh New Philosophical Journal, vol. xvi, pp. 316-334, pl. vi, 1834. Cornalia, Emilio, and Panceri, Paolo. Osservazioni zoologico ed anatomische sopra un nuovo genre di Isopodi sedentari (Gyge branchialis). <( Memorie della Reale Accademia delle Scienze di Torino, II, tom. xix, pp. 85-118, pli-ii. Turin, 1861. Cuvier, Georges. Le Régne Animal. See Edwards, Henri Milne, and Latreille, Pierre Andre. Czeyniavski, Voldemar. Materialia ad Zoographiam Ponticam comparatam. “Transactions of the first meeting of Russian Naturalists at St. Petersburg, 1868.” pp. 19-136, pl. i-viii. ‘ 1870.” _ Dalyell, John Graham. The Powers of the Creator displayed in the Creation. [3 vols., 4to, 145 plates.] London, 1851-1858. Dana, James Dwight. Conspectus Crustaceorum, &c. Conspectus of the Crustacea of the Exploring Expedition * * continued. Crustacea Isopoda. < American Journal of Science and Arts, II, vol. viii, pp. 424-428. New Haven, 1849. - Dana, James Dwight. On the classification of the Crustacea choristopoda or tetra- decapoda. <( American Journal of Science and Arts, II, vol. xiv, pp. 297-316. New Haven, 1852. _ Dana, James Dwight. Report on the Crustacea of the United States Exploring Ex- pedition, under the command of Charles Wilkes, U. S. N., 1838-42. Washington, Text [4to, two parts, 1618 pages], 1853. Atlas [folio, 96 plates], 1855. Dekay, James E. Zoology of New York or the New York Fauna. Part iv, Crus- tacea. [4to, 70 pages, 13 plates.] Albany, 1844. 438 REPORT OF COMMISSIONER OF FISH AND FISHERIES. Desmarest, Ansleme Gaetan. Malacostracés. < Dictionnaire des Sciences natur- — elles, tome xxviii, pp. 138-425 [56 plates]. Paris, 1823. Desmarest, Ansleme Gaetan. Considerations générales sur la classe des Crustacés, [8vo, 446 pages, 56 plates.] Paris, 1825, Dohrn, Anton. Untersuchungen iiber Bau und Entwicklung der Arthropoden. 4. Entwicklung und Organisation von Praniza (Anceus) maxillaris. < Zeit- schrift fiir wissenschaftliche Zoologie, Band xx, pp. 55-80, taf. vi-vili.—5. Zur Kentniss des Baues von Paranthura Costana. ou do: . ae | fA Bowe 2 3 EXPLANATION OF THE PLATES. PLATE I. FiGguRE 1.—Philoscia vittata Say (p. 306); dorsal view, enlarged six diameters; natural size indicated by cross at the right. 2.—Scyphacella arenicola Smith (p. 307); dorsal view, enlarged about twelve diameters; natural size indicated by cross at the right. 3.—Actoniscus ellipticus Harger (p. 309); dorsal view, enlarged ten diame- ters; natural size indicated by line at the right. 4,—Jera albifrons Leach (p. 315); female; dorsal view, enlarged about ten diameters. 5.—The same; maxilliped from the left side, exterior view, enlarged twenty- five diameters; P, palpus; 1, external lamella. 6.—The same; maxillx, enlarged twenty-five diameters; a, outer, or second, pair of maxillx; b, inner, or first, pair of maxille; %, inner, e, outer lobe. 7.—The same ; inferior surface of the pleon of a female. 8.—The same; inferior surface of the pleon of a male. (All the figures were drawn from nature by O. Harger.) PLATE II. FIGURE 9.—Janira alta Harger (p. 321); dorsal view, enlarged five diameters; natural size indicated by line at the right. 10.—Janira spinosa Harger (p.323); dorsal view of female, enlarged six diameters. 11.—Munnopsis typica M. Sars (p. 330); dorsal view of male, enlarged about two diameters; 0, maxillipeds; m, basal segment; J, external lamella; 2 and 3, second and third segments of palpus of maxillipeds; ¢, outer maxille; d, inner maxille; e, one of the second pair of legs of the male; f, one of the natatory legs; g, abdominal operculum of the female, external view. (Figures 9 and 10 were drawn from nature by O. Harger; figure 11 is copied from M. Sars, drawn by G. O. Sars.) PATH TEE: FIGURE 12.—Janira alta (p. 321); a, maxilliped; P, palpus of maxilliped; 1, external lamella; b, mandible; P, palpus of mandible; d, dentigerous lamella; m, molar process, enlarged twenty-five diameters. 13.—The same ; inferior surface of the pleon, a in the female, } in the male, enlarged ten diameters; a, single opercular plate in the female; b, external; c, median plate of operculum of male. 14.—Munna Fabricii Kroyer (p. 325); female; dorsal view, enlarged about twenty diameters; natural size indicated by line at the right. 15.—Eurycope robusta Harger (p. 332); female; dorsal view, enlarged six diameters; natural size indicated by line at the right; a, antennula, enlarged twenty diameters; b, maxilliped; c, mandible; d, one of the first pair of legs, each enlarged twenty diameters; d’, propodus and dactylus of the first pair of legs, enlarged about thirty-eight diameters; e, propodus and dactylus of the second pair of legs, enlarged twenty 453 454 REPORT OF COMMISSIONER OF FISH AND FISHERIES. diameters; f, one of the sixth pair of legs; g, uropod, each enlarged twenty diameters. (Figure 14 was drawn from nature by Mr. J. H. Emerton, the others by O. Harger.) PLATE IV. FIGURE 16.—Chiridotea ceca Harger (p. 338); dorsal view, enlarged nearly four diameters; natural size indicated by the line at the right. 17.—The same; a, antennula; b, antenna; each enlarged twelve diameters. 18.—The same; a, maxilliped from the right side, external view; J, external lamella; m, maxilliped proper; 1, 2, 3, first, second, and third segments of the palpus of the maxilliped, enlarged twenty diameters; }, one of the first pair of legs, magnified twelve diameters; c, uropod from the left side, inner view, showing the two rami articulated near the tip. 19.—The same; pleopods of second pair from the right side, anterior views, enlarged ten diameters; a, common form in males; }, rarer form in male; s, elongated stylet, articulated near the base of the inner lamella; c, form in the female. 20.—Chiridotea Tuftsii Harger (p. 340); female; dorsal view, enlarged five diameters; natural size indicated by the line at the right. 21.—The same; left maxilliped, enlarged twenty-five diameters; e, external lamella; m, basal segment; 1, 2, 3, segments of palpus. 22.—The same; pleopod of the second pair, from a male, enlarged twenty diameters; s, elongated stylet, articulated near the base of the inner lamella. (All the figures were drawn from nature by O. Harger.) PLATE V- FIGURE 23.—Chiridotea Tuftsii Harger (p. 340); a, aniennula; 6, antenna; ¢, leg of the first pair; d, leg of the fourth pair; all enlarged twelve diameters; e, left uropod, or opercular valve, inner view, enlarged ten diameters. 24.—Idotea irrorata Edwards (p. 343); dorsal view, enlarged two diameters ; natural size shown by the line on the left. 25.—The same; a, antennula; 6, antenna; c, left uropod or opercular valve, external view; all enlarged six diameters. 26.—The same; a, right maxilliped, enlarged twelve diameters, 1, external lamella; m, basal segment; 1, 2,3, 4, segments of palpus of maxilliped ; b, pleopod of the second pair froma male, enlarged eight diameters, show- ing stylet, s, articulated near the base of the inner lamella. 27.—Idotea phosphorea Harger (p. 347); dorsal view, enlarged about two diameters; natural size shown by the line on the right. 28.—The same; a, antenna, enlarged six diameters; b, maxilliped, enlarged twelve diameters, showing, /, external lamella ; m, basal segments; 1, 2, 3, 4, segments of the palpus of maxilliped; c, leg of the first pair; d, leg of the second pair, both enlarged six diameters; e, right uropod, or opercular valve, inner view, enlarged six diameters. 29.—The same ; pleopod of the second pair from a male, enlarged eight diam- eters; s, stylet articulated near the base of the inner lamella; s’, distal end of stylet reversed and enlarged thirty diameters. (Figure 24 was drawn by Mr. J. H. Emerton, the others by O. Harger.) PLATE VI. FIGURE 30.—Idotea robusta Kréyer (p. 349); dorsal view, enlarged two diameters ; natural size shown by the line at the right. 31.—The same; a, antenna; b, leg of the first pair, each enlarged six diam- eters; c, left uropod, or opercular valve, inner view, enlarged four - diameters. TP” EXPLANATION OF THE PLATES. 455 Figure 32.—The same; a, maxilliped, enlarged twelve diameters ; 1, external lamella; 1, 2, 3, 4, segments of palpus; b, maxilla of the outer or second pair; c, pleopod of the second pair from a male, enlarged six diameters ; 8, stylet articulated near the base of the inner lamella. 33.—Synidotea nodulosa Harger (p. 351); dorsal view, enlarged four diam- eters; natural size indicated by the line at the right. 34.—The same; a, antennula; f, flagellar segment; b, antenna; ¢, leg of the first pair from the right side; d, right uropod, or opercular valve, all enlarged ten diameters. 35.—The same; a, maxilliped from the right side, showing, J, external lamella; m, basal segment; 1, 2, 3, segments of palpus, enlarged twenty diameters; b, maxilla of the outer or second pair; c, maxilla of the inner or first pair, both enlarged twenty diameters; d, pleopod of the second pair from a male, enlarged twelve diameters; s, stylet articulated near the base of the inner lamella. 36.—Erichsonia attenuata Harger (p. 356) ; dorsal view, enlarged three diam- eters, natural size indicated by the line at the right. (Figures 30 and 36 were drawn by Mr. J. H. Emerton, the others by O. Harger.) PLATE Vil. Figure 37.—Erichsonia attenuata Harger (p. 356); @, antennula; b, antenna, each enlarged twelve diameters; c, maxilliped, showing, J, external lamella, enlarged thirty diameters; d, uropod, or opercular valve, enlarged twelve diameters; e, pleopod of the second pair from a male, enlarged fifteen diameters; s, stylet, articulated near the base of the inner la- mella; s’, distal end of stylet, enlarged fifty diameters. 38.—Erichsonia filiformis Harger (p. 355); dorsal view, enlarged five diam- eters, natural size indicated by the line at the right. 39.—The same; a, antennula; }, antenna; ¢, leg of the first pair; d, uropod, or opercular valve, each enlarged twelve diameters. 40.—The same; a, maxilla of outer or second pair; }, maxilla of inner or first pair; c, mandible, showing molar process, m, and dentigerous lamella, d, all enlarged thirty diameters. 41,—The same; a, maxilliped, showing, /, external lamella; m, basal segment, and 1, 2,3, 4, segments of palpus, enlarged thirty diameters ; b, pleopod of the second pair from a male, enlarged fifteen diameters ; 8, stylet, ar- ticulated near the base of the inner lamella; s’, distal end of stylet, enlarged fifty diameters. 42,—Epelys trilobus Smith (p. 358); dorsal view, enlarged ten diameters; natural size indicated by the line at the right. 43,—The same; a, maxilliped from the left side, enlarged twenty diameters ; 1, external lamella; m, basal segment; 1, 2, 3, segments of palpus of maxilliped; b, pleopod of second pair from a male, enlarged twenty diameters; s, stylet, articulated near the base of the inner lamella; s', end of stylet, enlarged fifty diameters. (All the figures were drawn from nature by O. Harger.) PLATE VIII. Figure 44.—Epelys montosus Harger (p. 359); dorsal view, enlarged six diameters, natural size indicated by the line at the right. 45.—The same; a, antennula; f, flagellar segment; b, antenna; ¢, maxilliped from the left side; 1, external lamella; m, basal segment; 1,2, 3, seg- ments of palpus; all the figures enlarged twenty diameters. 46.—The same; a, leg of the first pair, enlarged twenty diameters ; b, right uropod or opercular valve, enlarged fifteen diameters. 456 REPORT OF COMMISSIONER OF FISH AND FISHERIES. _ Figure 47.—The same; pleopod of the second pair, from a male, enlarged twenty di- — ameters; 8, stylet, articulated near the base of the inner lamella; ¢’, distal end of stylet, enlarged sixty-six diameters. 48.—Astacilla granulata Harger (p. 364); female; dorsal view, enlarged four diameters, natural size indicated by the line at the right; a, antennula of male; b, fourth thoracic segment of male; ¢, inferior surface of pleon of a male, showing opercular valves; all the figures enlarged four diameters. 49.—The same; a, flagellum of antenna, enlarged twenty diameters; a’, por- tion of inner margin of the same, enlarged one hundred diameters; b, one of the first pair of legs, upper surface, enlarged twenty diameters. 50.—The same; one of the fourth pair of legs, enlarged twenty diameters. 51.—The same; inner surface of left opercular plate, or uropod, from a female, enlarged twenty diameters. (All the figures were drawn from nature by O. Harger.) PPA PAUARY lke Figure 52.—Astacilla granulata Harger (p. 364); a, maxilliped; m, basal segment; l, external lamella; b, outer maxilla; c, inner maxilla; all enlarged twenty diameters. 53.—Spheroma quadridentatum Say (p. 368); dorsal view, enlarged five diameters; natural size indicated by the line at the right. 54.—The same; a, antennula; b, antenna; c, pleopod of the second pair, from a male, showing stylet, s, articulated near the base of the inner lamella; all the figures enlarged ten diameters. 55.—Limnoria lignorum White (p. 373); dorsal view, enlarged ten diameters ; natural size indicated by the line at the right. 56.—The same; a, antennula;-b, antenna; c, maxilliped; d, maxilla of the outer or second pair; e, maxilla of the inner or first pair; f, mandible, all enlarged twenty-five diameters; e’, distal end of outer lobe of first pair of maxillz, enlarged sixty-six diameters. 57.—The same; a, last segment of pleon, with attached uropods; dorsal view, enlarged ten diameters; b, uropod with dotted adjacent outline of last segment of pleon, enlarged thirty diameters; ¢, first pair of pleopods; d, pleopod of the second pair, from a male, showing stylet, s, articu- lated to the inner lamella; both figures enlarged twenty diameters. 58.—Cirolana concharum Harger, (p. 378); lateral view, enlarged about three diameters. (Figure 53 was drawn by Mr. J. H. Emerton, 55 by Prof. §. I. Smith, 58 by Mr. J. H. Blake, and the others by O. Harger.) PLATE X. Figure 59.—Cirolana concharum Harger (p. 378); dorsal view, enlarged about three diameters. The natural size is shown by the line at the right. 60.—The same; antennula, enlarged ten diameters. 61.—The same; a, antenna enlarged ten diameters; b, maxilla of the outer or second pair; c, maxilla of the inner or first pair; d, mandible from the right side, inner view; p, palpus; m, molar area; the last three figures enlarged five diameters. 62.—The same; a, maxilliped from the right side, exterior view, showing, l, external lamella; m, basal segment; 1, 2, 3, 4, 5, segments of the palpus; b, leg of the fourth pair; both the figures enlarged five diameters. 63.—The same; uropod from the right side; inferior view, enlarged five di- ameters. 64.—Aga psora Kréyer (p. 384); a, dorsal and 6 ventral views of a young indi- vidual. . The central line.indicates the length of:the specimen, natural . | | EEE EXPLANATION OF THE- PLATES, 457 size» which is here enlarged three diameters. Adults attain about’ the size of the figure. Figure 65.—Nerocila munda Harger (p. 392); dorsal view of the type specimen, en- larged about four diameters. The natural size is shown by the cross on the right; a, uropod, enlarged six diameters. 66.—Zigathoa loliginea Harger (p. 393); type specimen; a, dorsal, and b, ven- tral view, enlarged four diameters. Its natural size is shown by the line between the figures. (Figure 59 was drawn by Mr. J. H. Blake, the others by O. Harger.) PLATE XI. FIGURE 67.—Livoneca ovalis White (p. 395); a, antennula; b, antenna; c, mandibular palpus; each enlarged twenty diameters; d, one of the first pair of legs; e, one of the seventh pair of legs; /, uropod; each enlarged ten diam- eters. 68.—Anthura polita Stimpson (p. 398); dorsal view, enlarged four diameters. The natural size is shown by the line at the right; a, antennula; 3B, antenna, each enlarged ten diameters; c, leg of the first pair; d, leg of the third pair; e, right pleopod of the first pair, interior view, showing inner ramus without cilia; f, pleopod of the second pair from a male, showing stylet articulated to inner lamella; each of the figures c to f enlarged eight diameters; g, lateral view of pleon, enlarged six diam- eters. 69.—The same; a, maxilliped, enlarged twenty diameters; b, maxilla, enlarged twenty-five diameters; b’, distal end of the same, enlarged sixty diam- eters. 70.—Paranthura brachiata Harger (p. 402); dorsal view, enlarged about three diameters ; natural size shown by the line at the right; a, antennula; b, antenna, enlarged eight diameters; c, right maxilliped, enlarged six- teen diameters; d, maxilla, enlarged sixteen diameters; d’, distal end of the same, enlarged fifty diameters; e, leg of the first pair; f, first pleopod from the right side, inner view, showing ciliated inner lamella}; g, pleopod of the second pair from a male, showing stylet articulated to the inner lamella; figures e to g enlarged eight diameters. 71.—Ptilanthura tenuis Harger (p. 406); male; dorsal view, enlarged about four diameters; a, inferior view of the head and first thoracic segment, enlarged eight diameters; the flagellum of the antennule omitted; b, maxilliped; c, maxilla, each enlarged fifty diameters ; d, first right ple- opod, seen from within, showing ciliated inner lamella; e, second left pleopod, showing stylet s articulated to the inner lamella in the males. 72.—The same; one of the first pair of legs of a male, enlarged sixteen diam- eters. 73.—The same; female; dorsal view of the head, enlarged twenty-five diam- eters. (Figure 71, excepting b-d, was drawn by Mr. J. H. Emerton, the others by O. Harger.) PLATE XII. FIGURE 74.—Ptilanthura tenuis Harger (p. 406); a, antennula; b, antenna; each enlarged twenty diameters, from a male. 75.—Gnathia cerina Harger (p. 410); male; dorsal view, enlarged ten diame- ters. 76.—The same; a, antennula; b, antenna, each enlarged thirty-eight diame- ters; c, mandibles (1, left, r, right), enlarged thirty-eight diameters ; d, first leg or first gnathopod from the right side, enlarged twenty-five diameters; all the figures from the male sex. 77.—The same (p. 411); female; dorsal view, enlarged:ten diameters. 458 REPORT OF COMMISSIONER OF FISH AND FISHERIES. ‘FIGURE 78.—The same; a, one of the first pair of legs or first gnathopod of a female, enlarged thirty-eight diameters; 6, one of the first pair of legs in a young, parasitic individual, enlarged sixty diameters; c, pleon, with the last and part of the penultimate thoracic segments of a female, dorsal view, enlarged twenty diameters; d, pleopod of a young, pari- sitic individual, enlarged sixty diameters; e, pleopod of an adult male, enlarged sixty diameters. 79.—The same; young male; dorsal view, enlarged twenty diameters. 80.—Leptochelia algicola Harger (p. 421); male; lateral view, enlarged twenty diameters; natural size indicated by the line above. (All the figures were drawn from nature by O. Harger.) PLATE XIII. FIGURE 81.—Tanais vittatus Lilljeborg (p. 418); dorsal view, enlarged eight diame- ters. The transverse bands of hairs on the pleon are not sufficiently distinct. 82.—The same; one of the first pair of pleopods, enlarged thirty diameters. 83.—Leptochelia algicola Harger (p. 421); female; dorsal view, enlarged twenty diameters; natural size indicated by the line at the right. 84.—The same; ¢, antennula; b, one of the first pair of legs; both from a female specimen and enlarged twenty-five diameters. 85.—The same; hand, or propodus and dactylus of the first pair of legs, enlarged forty-eight diameters, showing the comb of sete on the pro- podus. 86.—The same; uropods of a male, enlarged seventy diameters; b, basal seg- ment; i, inner six-jointed ramus; 0, outer ramus. 87.—Leptochelia limicola Harger (p. 424); female; dorsal view, enlarged twenty diameters; natural size shown by the line at the right. 88.—The same; a, antennula; 6, antenna; c, leg of the first pair; d, leg of the second pair; all from the female sex and enlarged twenty-five diameters. 89.—Leptochelia rapax Harger (p. 424); male; dorsal view, enlarged about twelve diameters. 90.—The same; hand, or propodus and dactylus of male, enlarged sixteen diameters. 91.—Leptochelia coeca Harger (p. 427); type specimen, female; a, antennula; b, leg of the first, pair; c, uropod; each enlarged fifty diameters. (All the figures were drawn from nature by O. Harger.) PLATE I FIGURE 1.—Philoscia vittata Say (p. 306); dorsal view, enlarged six diameters; natural size indicated by cross at the right. 2.—Scyphacella arenicola Smith (p. 307); dorsal view, enlarged about twelve diameters; natural size indicated by cross at the right. 3.—Actoniscus ellipticus Harger (p. 309); dorsal view, enlarged ten diame- ters; natural size indicated by line at the right. 4.—Jera albifrons Leach (p. 315); female; dorsal view, enlarged about ten diameters. 5.—The same; maxilliped from the left side, exterior view, enlarged twenty- five diameters; P, palpus; /, external lamella. 6.—The same; maxillx, enlarged twenty-five diameters; a, outer, or second, pair of maxille; b, inner, or first, pair of maxille; t, inner, ¢, outer lobe. 7.—The same; inferior surface of the pleon of a female. 8.—The same; inferior surface of the pleon of a male. (All the figures were drawn from nature by O. Harger.) Plate I. Report U. S. F. C. 1878.—Harger. Marine Isopods. ¥ atteie Dowia: ‘ Ahuwiael, ian% eemeatst | OD SPORE GS P65, 5 ese suid i rs are TERS fe Fast Stuns D PLATE II. FicurE 9.—Janira alta Harger (p. 321); dorsal view, enlarged five diameters; natural size indicated by line at the right. 10.—Janira spinosa Harger (p.323); dorsal view of female, enlarged six diameters. 11.—Munnopsis typica M. Sars (p. 330); dorsal view of male, enlarged about . two diameters; 6, maxillipeds; m, basal segment; J, external lamella; 2 and 3, second and third segments of palpus of maxillipeds; c, outer maxille; d, inner maxillx; e, one of the second pair of legs of the male; Jf, one of the natatory legs; g, abdominal operculum of the female, external view. (Figures 9 and 10 were drawn from nature by O. Harger; figure 11 is copied from M. Sars, drawn by G. O. Sars.) F Report U. S. F. C. 1878.—Harger. Marine Isopods per eh ol alle m, “i ‘ v9 = ye 4 hs ' mt id sek 7 ‘| ‘aad 7 peed hy ered ; M a. 4 ons ‘ a D rt ‘ wo . = ‘ \ L ‘ / j , * ‘ - a he oa jit A oa ' i YW é ¥- } ‘ : ( . ” ' "Ss ‘ D a - Ps y ‘ a Mee a 7 ‘Dix 2 a re - Li ayes ‘ t ae] ’ 4 7 ‘ 4. ’ ve 7 + A . i we N A 7 , i f ai r ; te J r, = oe PLATE-Ifl. FIGURE 12.—Janira alta (p. 321); a, maxilliped; Pp, palpus of maxilliped; 1, external lamella; 6, mandible; P, palpus of mandible; d, dentigerous lamella; m, molar process, enlarged twenty-five diameters. 13.—The same; inferior surface of the pleon, a in the female, 6 in the male, enlarged ten diameters; a@, single opercular plate in the female; b, external; c, median plate of operculum of male. 14,—Munna Fabricii Kroyer (p. 325); female; dorsal view, enlarged about twenty diameters; natural size indicated by line at the right. 15.—Eurycope robusta Harger (p. 332); female; dorsal view, enlarged six diameters; natural size indicated by line at the right; a, antennula, enlarged twenty diameters; b, maxilliped; c, mandible; d, one of the first pair of legs, each enlarged twenty diameters; d’, propodus and dactylus of the first pair of legs, enlarged about thirty-eight diameters; €, propodus and dactylus of the second pair of legs, enlarged twenty diameters; jf, one of the sixth pair of legs; g, uropod, each enlarged twenty diameters. (Figure 14 was drawn from nature by Mr. J. H. Emerton, the others by O. Harger.) Report U. 8. F. C. 1878.—Harger. Marine Isopods. ~ Plate ITI. A a \\I e ‘4 a x J th att : A AY ni } fas Ae aT ¢ a eae hy er A v7 ‘ ‘ I My: ry iT Aone 4 fwar® i . TK wtp Re ete ats Be | ¢ Net 3 i : 4 hy mt - sea Baul Pel af f Ny ote ye a i ae ee) p wr? ) 7 " Bee oka o i 0 i A Re VS ; ive y 1 = at f | ite \ { { * i y > { La i , i | * " rf yA i w \ \ 1 a vs rs J Af ¥ ot Mid ‘ey .y } : f ; He ‘ 7 ) s ( af a : ab) 7% ey a H, bat BN A ie - mY ‘a 7 ts \ aa ‘ Dy A th A) ‘76 ‘ ul ‘ ob : 1) pe i" Mi) / 2 , * , ? ' | ator st 4 on UD Te, a Lowe S, f 1 ‘ee BS Suis, . Josue PLATE IV. FIGURE 16.—Chiridotea ceca Harger (p. 338); dorsal view, enlarged nearly four diameters ; natural size indicated by the line at the right. 17.—The same; a, antennula; 6, antenna; each enlarged twelve diameters. 18.—The same; a, maxilliped from the right side, external view ; 1, external lamella; m, maxilliped proper; 1, 2, 3, first, second, and third segments ef the palpus of the maxilliped, enlarged twenty diameters; b, one of the first pair of legs, magnified twelve diameters; e, uropod from the . left side, inner view, showing the two rami articulated near the tip. 19.—The same ; pleopods of second pair from the right side, anterior views, enlarged ten diameters; @, common form in males; }b, rarer form in male; s, elongated stylet, articulated near the base of the inner lamella; ¢, form in the female. 20.—Chiridotea Tuftsii Harger (p. 340); female; dorsal view, enlarged five diameters; natural size indicated by the line at the right. 21.—The same; left maxilliped, enlarged twenty-five diameters; e, external lamella; m, basal segment; 1, 2, 3, segments of palpus. 22.—The same; pleopod of the second pair, from a male, enlarged twenty diameters; 8, elongated stylet, articulated near the base of the inner lamella. (All the figures were drawn from nature by O..Harger.) Report U. S. F. C. 1878.—Harger. Marine Isopods. Plate IV. i) ea © 6) Zan “f 4 10K ww ia 4 N i - . y er 1 or ; ote ee Seer pr re at et mp: eet mete eee ly ‘+70 ah I : wee ih ais VN ay) ‘ ' - a | tt: ae) wane ‘ ML re al it I vie . : rs : Sia a) Yrs CiSh as to aN Ps ae ~ PLATE V. FicuReE 23.—Chiridotea Tuftsii Harger (p. 340); a, antennula; b, antenna; ¢, leg of the first pair; d, leg of the fourth pair; all enlarged twelve diameters; e, left uropod, or opercular valve, inner view, enlarged ten diameters. 24.—Idotea irrorata Edwards (p. 343); dorsal view, enlarged two diameters ;. natural size shown by the line on the left. 25.—The same; a, antennula; 6, antenna; c, left uropod or opercular valve, external view; all enlarged six diameters. 26.—The same; a, right maxilliped, enlarged twelve diameters, J, external lamella; m, basal segment; 1, 2,3, 4, segments of palpus of maxilliped ; b, pleopod of the second pair from a male, enlarged eight diameters, show- ing stylet, s, articulated near the base of the inner lamella. 27.—Idotea phosphorea Harger (p. 347); dorsal view, enlarged about two diameters; natural size shown by the line on the right. 28.—The same; a, antenna, enlarged six diameters; b, maxilliped, enlarged twelve diameters, showing, /, external lamella ; m, basal segments; 1, 2, 3, 4, segments of the palpus of maxilliped ; c, leg of the first pair; d, leg of the second pair, both enlarged six diameters; e, right uropod, or opercular valve, inner view, enlarged six diameters. 29.—The same ; pleopod of the second pair from a male, enlarged eight diam- eters; s, stylet articulated near the base of the inner lamella; 8’, distal end of stylet reversed and enlarged thirty diameters. (Figure 24 was drawn by Mr. J. H. Emerton, the others by O. Harger.) Report U. S. F. C. 1878.—Harger. Marine Isopods. Plate V. No.958. Ie: MAUR «ASO kd eA Ae Ne eae ‘ | Mi inte al x ii agit ] om P re Samarra nent ae mn nanan mene neon he ae Pe Hew Bo . iv / y* J \ is ‘ : ‘ > ‘J if F q ~~ * & ae eee ae > is Ys i@e __ 4 \ ‘ \ - is has , f ¥ ney . 4 u i ‘ 4 a “a oe } ‘ s ' . ‘ ‘ * j a ' i y ~ | , 1 ( | ~ 7 aes " L } t - . — 1 inf ws ‘ i -- ~ | - ¢ : hina ‘ | ¥ A \ 4 F = - af if / teu ; i é ’ i st - r _ & a als - d 44 tig : + 7 an \ we? a) \ ‘ as vr ~ a ' \ ; i on i } wi rs Ee yf ‘ ike r ; ? r ; — Pm > 6 a ‘ i ; Z d * ¢, { Pe S en ‘ 4 a P A hy es ; ' ‘ ear ¥ 4 7 APD te { - ] ‘ AL % : 4 ii : _ . , 4 J Be 4 ca =, : Z ' 4 : a? Pig NG * AS ji js } , - ‘ , ; # y - 7 ‘ has 7 ¥ ‘ i> Gog 6. aor ae io . | PONE See wareMe eh | ‘ ' &*s \ , : b} 2 ‘ Wi ger “E> es, } hel : , ef i! << | \ pe aes, Ce ee Hi ’ ain Sia dhe a a" H . f mi or by f Sau! I \ ° {A 4 : ' 4 f & { A i % rl j . a x ‘ bs “ ' R =r Le 7 , Al Milos is v neil 5 * s] b ae j , he Pd ry a . A 4 m Fe.) a | ' } J a ¥ te \ is y ’ \ ‘ ‘ , i ‘ig 4 * } T ‘ \ Ve 1 i i | a a? | Te Awan) can ERSTE ELE bra sy a Cea ’ rs PEI LET»! StS Wor Pye ay Aa De ba Oe eter 7 Ue pes Geile. GIL — roe i eer? je Ent tlle 3 op PO SIGUMO Gag fovisite a =" PLATE VI. FIGURE 30.—Idotea robusta Kroyer (p. 349); dorsal view, enlarged two diameters ; natural size shown by the line at the right. 31.—The same; a, antenna; b, leg of the first pair, each enlarged six diam- eters; c, left uropod, or opercular valve, inner view, enlarged four diameters. FIGURE 32.—The same; a, maxilliped, enlarged twelve diameters; J, external lamella; 1, 2, 3, 4, segments of palpus; 6, maxilla of the outer or second pair; c, pleopod of the second pair from a male, enlarged six diameters; s, stylet articulated near the base of the inner lamella. 33.—Synidotea nodulosa Harger (p. 351); dorsal view, enlarged four diam- eters; natural size indicated by the line at the right. 34.—The same; a, antennula; f, flagellar segment; b, antenna; ¢, leg of the first pair from the right side; d, right uropod, or opercular valve, all enlarged ten diameters. 35.—The same; a, maxilliped from the right side, showing, J, external lamella; m, basal segment; 1, 2, 3, segments of palpus, enlarged twenty diameters; 6, maxilla of the outer or second pair; c, maxilla of the inner or first pair, both enlarged twenty diameters; d, pleopod of the second pair from a male, enlarged twelve diameters; 8, stylet articulated near the base of the inner lamella. 36.—Erichsonia attenuata Harger (p. 356) ; dorsal view, enlarged three diam- eters, natural size indicated by the line at the right. (Figures 30 and 36 were drawn by Mr. J. H. Emerton, the others by O. Harger.) ee ee ee ee __ pin . a Sa ee ee PLATE Vit: ee eS FIGURE 37.—Erichsonia attenuata Harger (p. 356); a, antennula; b, antenna, each enlarged twelve diameters; c, maxilliped, showing, J, external lamella, | enlarged thirty diameters; d, uropod, or opercular valve, enlarged . twelve diameters; e, pleopod of the second pair from a male, enlarged fifteen diameters; s, stylet, articulated near the base of the inner la- mella; s’, distal end of stylet, enlarged fifty diameters. 38.—Erichsonia filiformis Harger (p. 355); dorsal view, enlarged five diam- eters, natural size indicated by the line at the right. 39.—The same ; a, antennula; 6b, antenna; ¢, leg of the first pair; d, uropod, or opercular valve, each enlarged twelve diameters. 40.—The same; a, maxilla of outer or second pair; b, maxilla of inner or first pair; ¢, mandible! showing molar process, bo and dentigerous lamella, d, all enlarged thirty diameters. 41.—The same; a, maxilliped, showing, !, external lamella; m, basal segment, and 1,2, 3, 4,segments of palpus, enlarged thirty diameters; b, pleopod of the second pair from a male, enlarged fifteen diameters ; s, stylet, ar- ticulated near the base of the inner lamella; s’, distal end of stylet, enlarged fifty diameters. 42.—Epelys trilobus Smith (p. 358); dorsal view, enlarged ten diameters; natural size indicated by the line at the right. 43.-~The same; a, maxilliped from the left side, enlarged twenty diameters; 1, external lamella; m, basal segment; 1, 2, 3, segments of palpus of maxilliped; b, pleopod of second pair from a male, enlarged twenty diameters; 8, stylet, articulated near the base of the inner lamella; s’, end of stylet, enlarged fifty diameters. (All the figures were drawn from nature by O. Harger.) Plate VII. Report U. S. F. C. 1878.—Harger. Marine Isopods. r ee ~ —_ ; . _— Cea.) oe 7) PLATE XIII. FiGurE 81.—Tanais vittatus Lilljeborg (p. 418); dorsal view, enlarged eight diame- ters. The transverse bands of hairs on the pleon are not sufficiently distinct. 82.—The same; one of the first pair of pleopods, enlarged thirty diameters. 83.—Leptochelia algicola Harger (p. 421); female; dorsal view, enlarged twenty diameters; natural size indicated by the line at the right. 84.—The same; a, antennula; b, one of the first pair of legs; both from a female specimen and enlarged twenty-five diameters. | 85.—The same; hand, or propodus and dactylus of the first pair of legs, enlarged forty-eight diameters, showing the comb of sets on the pro- podus. 86.—The same; uropods of a male, enlarged seventy diameters; 6b, basal seg- ment; i, inner six-jointed ramus; 0, outer ramus. 87.—Leptochelia limicola Harger (p. 424); female; dorsal view, enlarged twenty diameters; natural size shown by the line at the right. 88.—The same; a, antennula; b, antenna; c, leg of the first pair; d, leg of the second pair; all from the female sex and enlarged twenty-five diameters. 89.—Leptochelia rapax Harger (p. 424); male; dorsal view, enlarged about twelve diameters. 90.—The same; hand, or propodus and dactylus of male, enlarged sixteen diameters. 91.—Leptochelia coeca Harger (p. 427); type specimen, female; a, antennula; b, leg of the first pair; c, uropod; each enlarged fifty diameters. (All the figures were drawn from nature by O. Harger.) = -- FF °° ~ Report U. S. F. C. 1878.—Harger. Marine Isopods. Plate XIII. No.917. rth. Otek: { ‘ —* > i 4 - s i } i 7 P a 3 e ae | ty i ei of rh i “ at | meee NT ee ALPHABETICAL INDEX TO THE REPORT ON THE MARINE ISOPODA OF NEW ENGLAND AND ADJACENT WATERS. [In the following index the first reference for the names of the families, genera, and species here de- scribed is to the page on which such descriptionis made. The list of authorities, being alphabetically arranged, is not indexed.] Abdomen, 298. Actzcta, 309. Actoniscus, 309, 305. ellipticus, 309, 428, 433. Bga, 383, 377, 378, 387, 431. concharum, 378. emarginata, 384. entaillée, 384. polita, 381. psora, 384, 429, 430, 434, Aigathoa, 393, 391. loliginea, 393, 428, 434. RMgide, 382, 300, 303, 377, 430, 431. Z£ro-spirantia, 305. Alitropus, 391. Anceus, 409, 410. americanus, 410, 411. elongatus, 412. Ancoral legs, 300. Andrews, A, on Limnoria, 375. Anilocra, 391. mediterranea, 430. Anisocheirus, 416. Antenne, 298. Antennulz, 298. Anthura, 398, 301, 397, 431. brunnea, 398, 401. earinata, 401. gracilis, 398, 401. polita, 398, 406, 429, 434. Anthuride, 396, 301, 303, 361, 431. Apseudes, 304, 414, 416, 431. Arcturide, 361, 303, 397, 430, 431. Arcturus, 361, 363. Bafiini, 362. Armadillida, 314. Armadillo, 305. Armida bimarginata, 343. Artystone, 390. Asellida, 312, 303, 314, 371, 372, 430, 431. _ Asellodes, 319. alta, 319, 321. Asellotes homopodes, 371. Asellus, 301, 313, 415. communis, 314. Grénlandicus, 315, 319. Astacilla, 361, 297, 301, 363, 431. Americana, 364. granulata, 364, 362, 429, 434. longicornis, 362, 363, 366. Basis, 300. Bate, C.Spence, on the incubatory pouch, 302. Bate, C. Spence, on terminology of crustacea, 300, Bate and Westwood, on Z®ro-spirantia, 305. (802. Anceus, 409. Anthura, 398. Anthura gracilis, 401. British Isopoda, 429. Idotea tricuspidata, 345. Jeera albifrons, 318. Limnoria, 372. Paranthura, 402. Tannis, 416. Tanais Edwardsii, 422. Bathynomus giganteus, 383. Bopyrid, 311, 377, 429, 431. Bopyrus, 312, 431. abdominalis, 312. Hippolytes, 311. Mysidum, 312. species, 312, 428, 433. Brevoortia menhaden, 391. Bullar, J. F., hermaphroditism in Cymothoida, 391. Cancer maxillaris, 410. Carpus, 300. Cepon distortus, 311, 428, 433. Ceratacanthus, 393. Chaetilia, 336. Chela, 300. Chelura terebrans, 371, 376, 419, 423. Chiridotea, 337, 300, 335, 336. ceca, 338, 335, 340, 429, 433, entomon, 337. Tuftsii, 340, 429, 433. Cirolana, 378, 376, 383, 431. concharum, 378, 298, 428, 484. polita, 381, 429, 434. truncata, 430. Cirolanid, 376, 303, 382, 430, 431. Cleantis, 336. Ceecidotea, 314. Coldstream, J., on Limnoria, 372, Conilera, 376, 378. concharnm, 378. polita, 381. Cordiner, C., on Astacilla, 363. Coxa, 300. Crossurus, 416. vittatus, 416, 418, Cuma, 41 PRIS. 383, 391. cestrum, 377. ovalis, 395. TR, ator, 391. a TeKe 459 460 REPORT OF COMMISSIONER: OF FISH AND FISHERIES: Cymothow, 377. Cymothoide, 390,300, 303, 371, 382, 430, 431. Dactylus, 300. Dajus Mysidis, 312, 429, 433. Dana, J. D., on Asellidax, 314. Desmarest, A. G., on Idotea tricuspidata, 345. Digital process, 300. Dohrn, A., on Anceus, 409. the incubatory pouch, 301, 303. Tanaide, 415. Edriophthalma, 297. Edwards, H., on Idotea tricuspidata, 345. Limnoria, 371. Tanais, 416. Epelys, 357, 301, 337. montosus, 359, 429, 434. var. hirsutus, 360. trilobus, 358, 429, 434. Epimera, 300. abdominal, 392. Erichsonia, 354, 337, 361. attenuata, 356, 335, 428, 434. filiformis, 355, 428, 434. Eurycope, 332, 329. cornuta, 333. robusta, 332, 429, 433. Flagellum, 298. Fleming, J., on Astacilla, 363, Gadus, 386. Gammarus Dulongii, 416. Gegenbaur, C., on Tanaida, 415. Gelasimus pugilator, 311. Geographical distribution, 428. Gnathia, 410, 297, 302, 357, 431. cerina, 410, 429, 435. termitoides, 410. Gnathiida, 408, 300, 301, 303, 431. Gnathium, 410. Gnathopods, 300. Goodsir, H. D.S., on Astacilla, 363. Gribble, 375. Gyge, 431. Gyge Hippolytes, 311, 429, 433. Helleria, 305. Henopomus tricornis, 322. Hesse, E., on Anceus and Praniza, 409. Hippoglossus, 382, 386. Hippolyte Fabricii, 311. polaris, 311. pusiola, 311, 312. securifrons, 311, 312. spinus, 311, 312. Huxley, T. H., distinction of cephalic and thoracic Ideotea marina, 344. [segments, 302: Idotea, 341, 337, 431. acuminata, 344. Basteri, 343. bicuspida, 352. coca, 338, entomon, 345. filiformis, 355. irrorata, 343, 342, 348, 429, 430, 483. marina, 344. marmorata, 352. metallica, 349, 350. montosa, 359. Idotea nodulosa, 352. pelagica, 343, 345, 346. phosphorea, 347, 342, 346, 429, 438. pulchra, 352. robusta, 349, 342, 429, 433. tricuspidata, 343, 345, 346. tricuspis, 344. tridentata, 344, 345. Tuftsii, 340. variegata, 343. Idoteide, 335, 301, 303, 361, 397, 430, 431 Idothea balthica, 344, 346. nodulosa, 351. pelagica, 344. robusta, 349. Tyarachna, 334, 329, 335, 429, 433. Incubatory pouch, 301. Ischium, 300. Isopod, length of, 302. Isopoda, 297. aberrantia, 303. Jeera, 314, 301, 313, 430, 431. albifrons, 315, 318, 429, 480, 483, Baltica, 315, 318. copiosa, 315. Kroyeri, 315, 318. maculata, 315, 318. marina, 315, 318. nivalis, 315, 318. triloba, 358. Janira, 319, 313, 430, 431. alta, 321, 299, 429, 433. laciniata, 324. maculosa, 319, 322. spinosa, 328, 429, 433. Johnston, G., on Astacilla, 362. Kinahan, J. R., on Actzcia, 309. Kroyer, H., on Anthura carinata, 401, Munna, 325. Tanais Edwardsii, 422. Labium, 300. Labrum, 300. Lamella, external of maxillipeds, 299. Latreille, P. A., on Idotea tricuspidata, 345, Leachia, 361, 363. granulata, 364, 366. Leach, W. E., on Gnathia, 410. Leacia, 361, 363. Legs, 300. Leidya distorta, 311. Leidy, J., on Bopyrus species, 312. Cepon distortus, 311. Leptochelia, 420, 301, 414, 415, 431. algicola, 421, 429, 435. cmca, 427, 429, 435. Edwardsii, 416, 421, 422, 423. filum, 426, 429, 435. limicola, 424, 429, 435. minuta, 416. rapax, 424, 423, 429, 435. Leptophryxus Mysidis, 312. Ligia, 305, 310, 311, 415. Lilljeborg, W., on Jeera albifrons, 318, Limnoria, 373, 313, 371, 419, 480, 431. lignorum, 373, 423, 429, 480, 434. terebrans, 373. , Va ee er ALPHABETICAL INDEX. 461 Limnoria uncinata, 374, 376. Paratanais limicola, 424, 427. xylophaga, 371. Peduncle, 298. Limnoriade, 371. Pereion, 298, 300. Limnoriide, 371, 303, 43L Pereiopods, 300. Lironeca, 395. Pleon, 298, 301. Livoneca, 394, 383. Pleopods, 301. ovalis, 395, 300, 428, 434. Philoscia, 305. Lockington, W.N., on color of ldotea pulchra, 353. vittata, 306, 429, 433. Loligo Pealii, 394. Phryxus, 431. Macdonald, J. D., on Tanais vittatus, 417, 419. Phryxus abdominalis, 312, 429, 488. Mancasellus, 313. Hippolytes, 312, Mandibles, 299. Pill-bug, 298, 305. Maxille, 299. _ Platyarthrus, 308. Maxillipeds, 299. Pomatomus saltatrix, 396. Mayer, P., Hermaphroditism in Cymothoids, 391, | Porcellio, 305. Meinert, F., on Idotea tricuspidata, 846. Praniza, 409, 410. Merus, 300. cerina, 410, 412. Mesostenus, 334. ceruleata, 410. Metzger, A., on Jers albifrons, 318. Reinhardi, 413. Micropogon undulatus, 396. Propodus, 300. Mobius, K., on Jera marina, 318. Ptilanthura, 405, 398. Molar process, 299. oculata, 408. Montagu, G., on Oniscus gracilis, 401. tenuis, 406, 429, 435. Miller, F., on Bopyrids, 30%, 311. Raia, 386. Leptochelia and Paratanais, 420. Rathke, H., on Crossurus, 416, 417. olfactory sets, 298. Respiration, 302, 303. Tanaide, 303, 415. Rostrum, 302. Tanais Edwardsii, 423. Salve-bug, 384. Mullet, 394. Sars, G. O., on Eurycope, 332. Munna, 325, 313, 430, 431. Tlyarachna, 334. Boeckii, 325, 328. Munnopside, 329. Fabricii, 325, 429, 433. Munnopsis, 331. Munnopside, 328, 303, 314, 430. Sars, M., on Idotea tricuspidata, 346. Munnopsis, 329. Jeera albifrons, 318. typica, 330, 334, 429, 433. Munnopside, 329. Nerocila, 391. Munnopsis, 331. munda, 392, 428, 434. . Schiédte, J. C., on Anthura, 397. Norman, A. M., British Cymothoida, 430. Artystone, 390. Ocelli, 298. Cymothow, 377. Olfactory setz, 298. Scyphacella, 307. Oniscids, 305, 303, 311, 314. arenicola, 307, 428, 433. Oniscoidea, 314. Scyphax, 307. Oniscus albifrons, 315. ornatus, 309. Balthicus, 344, Serolids, 304. ceeruleatus, 410. Smith, S. L., list of Bopyride, 311. entomon, 344, Limnoria xylophaga, 371. gracilis, 401. Scyphacella, 307. marinus, 318. Sow-bug, 298, 299, 305. praegustator, 391. Spheroma, 368, 301, 367, 372, 430, 431. psora, 384, 386. quadridentatum, 368, 429, 434. Operculum, 302, 336. serratum, 430, Ourozeuktes, 377. Spheromida, 367, 303, 431. Palemonetes vulgaris, 312. Stebbing, T. R. R., on Astacilla, 362. Palpus, 299. f British Arcturida, 430. Pandalus borealis, 312. Dynamene rubra and vyiri- Montagui, 312. dis, 430. Paranthura, 402, 398, 431. j Tanais vittatus, 417,419. arctica, 405. - Stenosoma filiformis, 355. brachiata, 402, 429, 435. irrorata, 343. costana, 405. Stenotomus argyrops, 396. norvegica, 404, Stimpson, W., on Anceus americanus, 410, 413. tenuis, 406, 407. } Asellodes, 319. Paratanais, 416, 420, 431. H Cirolana concharum, 381, algicola, 419, 421. } Cirolana polita, 381.. cca, 427. f Praniza cerina, 412, 413. forcipatus, 423. Tanais filum, 426. 462 REPORT OF COMMISSIONER OF FISH AND FISHERIES. Synidotea, 350, 337. bicuspida, 352, 429, 433. nodulosa, 351, 299, 347, 429, 438. Syscenus, 387, 383, 391. infelix, 387, 429, 434. Tanaida, 415. Tanaide, 413, 298, 300, 302, 303, 304, 431. Tanais, 416, 297, 301, 414, 415, 431. Cavolinii, 416, 419. Dulongii, 416. Edwardsii, 416, 421, 423. filam, 420, 421, 423, 426. hirticaudatus, 418. islandicus, 428. Savignyi, 423. Tanais, tomentosus 418, 419. Telson, 301. Templeton, R., on Zeuxo, 416. Tetradecapoda, 297. Thorax, 298, 300. Tylus, 305. Uropods, 301. Verrill, A. E., on Chiridotea Tuftsii, 341 Venus mercenaria, 359. “Westwood, J. O.,on Anisocheirus, 416. White, A., on Limnoriada, 371. Willemoes-Suhm, R. v., on Tanais, 418 Wood-lice, 305. Zeuxo Westwoodiana, 416, vittatus, 418, 417, 420, 428, 429, 431, 435. 7 PSeeon x Pri na via ot phir eal Ae 2 Ai 4) i eee ne [Report of the United States Commissioner of Fish and Fisheries, Part vi. For_1878 Opposite page 462. ] ERRATA. Page 3138, line 5, for 79 read 371. Fao, 22, * 938 $8o: e « 93 40 “ 384. geposor 2 (20h V89r 383: pee SS OS FS. SRT Bmeete or ORS LOd <. SOR8) Me cee ee ee OS i 4.09: ere ss leer Mei iS AB Guess) ORs ee LAA AT GE pee 1866 tS S26 “< .420) eee ae, SON “" 1455: Cs 0 a C13 “435, lastline,*“* 1387 ‘* 431. In partial explanation of the above list of incorrect references, the author has to say that he had no opportunity of seeing a correctly paged proof of the article during the year that it was in press at the Government Printing Office. Or Ee pre — 76a? NA Na tlh i mia) i aye : ¢ 4 3 ; : Aaa Deis ARES RGU RSS an aWa s = 21227 aN RA AAA INRAR AMAA ACG = e RRR ARIVAIIAIN 3 AaAA AnanNn AAA nnn PAA An al Al A ial ny Anan tment ae NW : aan ' AANA Di era Ran sAGAeR AO saa aang aan 7 ARP AGAR REE AARAAAA fi 4 i % nepaper a nanny mM annua clues | , SR ABASK A AAI AAD n - wenn ARAMA Aaa APO MUARBPR Gahan cece tt RAR ran AR A nA aus NAAR EAA AR AARC Aa A RAS nanannnne intr Val Aan narra Tan vt i pn Q nnarennnnt | stent not npr enema tN Rae anoannean ne Ne s Wann aE nals | | ae MAAN a, cert Anan st pass Aaa, menenan aT ARAMA PRAT: ait Sane a stata nate ON “ annnatMAaahagh My Ro ‘anon o paar aA AannaAnan | A AAA Neca As aheaasaret NANA AA a hn wenn nanannnnran Aanhanana An ahaa Aang arvewnne sannnnann ! "HAAN sesewepttt AAA NwahnnAnanal a wannnn’ Annan anthnaatns’ BM vananynn tha Dkk LRA aan annnny aanantnny AA. maARhAee >. Vv iS, Vv Swivel Wu" we GY Vv vis v ¢ Ny vy Wd Wid ‘WY ay V WW ven Ne NW Ne Ves Md i WO W YUU ride vey hd: 4 yt Wig ¥ ly Vv) y aes ho Fy v WW y Wule ou Wav Viv MV WY” ew Owyr iy Wily vy Wy) Wy i Vi y Vey UISY y WV My Ww yy Vv did wan Vy vw vw WW VAIS, Wig vill Ww Aj Aj ot sal | 3 9088 oe