^ ^ I IS >^i r'S'Copy. RECORDS of the INDIAN MUSEUM Vol. V, Part III, No. 17. Notes on Decdpoda in the Indidn Museum, I. J: By 5. KEMP. ^e. 33383^,,, C7VLCUTTA: SEPTEMBER, 1910. XVII. NOTES ON DECAPODA IN THE INDIAN M U S E Lm . I. — The Species of Gennadas. By STANI.EY Kemp, B.A., Assistant Superintendent, Indian Museum. (Plates xiii and xiv.) Among the vast collection of Decapods which has been made by the ' Investigator ' thirteen examples of the genus Gen- nadas occur and, although the majority of these specimens have already been mentioned by Alcock,' it has now become necessary to submit them to revision. In 1901, when Alcock wrote, the characters by which the many closeh'- allied species of this genus were determined had not been fully appreciated and our knowledge of the extra- Atlantic forms was limited almost entirel}^ to the wholly inadequate treatment which vSpence Bate accorded them in his ' Challenger' Report. Recently Bouvier has published a most valuable account* of the Atlantic species in which he draws attention to the importance of several characters which had previously been overlooked and, now that the * Challenger ' collections have been revised on the same lines ,^ the determination of the material preserved in the Indian ]\Iuseum presents a task of no great difficult5^ In the following descriptive notes all the more important characters suggested bj' Bouvier have been employed. It seems, however, that the Oriental species of the genus form a much more homogeneous group than those found in the Atlantic and, apart from the petasma and thelycum , little can be found which is of real systematic value. Useful indications are afforded by the antennular peduncle, the antennal scale and the second maxilla, but in other respects, such as the proportions of the mandibular palp and the respective lengths of the joints of the first three 1 Alcock, Desc. Cat. Ind. deep-sea Macrura, 1901, p. 45. ■?• Bouvier, Res. Camp. Sci. Monaco, fasc. xxxiii, 1908, p. 24. ■•> Kemp, Pyoc. Zool. Soc, 1909, p. 718. From the list of species of Gennadas given at the end of this paper (p. 728) two Pacific forms, G. clavicarpus and G. pasithea, are unfortunately omitted. Preliminary descriptions of these two species, which were obtained by the ' Siboga ' expedition, have been given by Dr. J. G. de Man (Xotcs Leyden Mns., xxix, 1907, p. 144). Both are, I believe, distinct from the ' Challenger 'species and from those here described, but, until figures of the petasmata and thelyca are published, it is impossible to be quite certain. 174 Records of the Indian Museinn, |Vol. V, pairs of peraeopods, a considerable amount of variation is some- times to be found. Three of the species in the collection are regarded as new, an interesting variation in the petasma of G. sciitatus, Bouvier, is noticed and a fresh description is given of G. carinatus, Smith, a remarkable form which combines in one species the characters both of Geiuiadas and of the allied genus Bcnthcsicynms. The number of specimens examined is unfortunatel}' small and this is doubtless due to the fact that the ' Investigator ' collections were made almost entireh^ by means of trawls fishing on the bottom. The species of Geiuiadas, as far as is at present known, are entirely pelagic in habit and their occasional appearance in bottom hauls is explained by the fact that they are sometimes caught while the net is being hauled to the surface. All the species mentioned in this paper possess podobranchs on the first three pairs of peraeopods and are in consequence members of the genus Gennadas, sensu stricto. The measurements given represent the total length, and were taken from the apex of the rostrum to the tip of the telson, with the animal extended as nearly as possible in a straight line. Gennadas alcocki, sp. nov. (Plate xiii, figs. 5—8.) St. III. — Bay of Bengal, 12° 50' N., 90° 52' E., 1,644 fathoms. One male, 36 mm. St. 103. — Bay of Bengal, 15° 14' N. , 81° 9' E., 1,260 fathoms. One female, about 25 mm. St. 108.— Off C. Comorin, 7° 4' N., 76° 34' 15" E-, 1,043 fath- oms. One male, 34 mm. St. 309. — Near the Andaman Islands, 10° 9' N., 93° 2' 15" E., 765 fathoms. One male, 34 mm. The rostrum is well elevated above the dorsal carina of the carapace and bears the usual small tubercle behind the dorsal tooth. The antennary and infra-antennary angles are acute and the branchiostegal spine is small but evident. The cervical and post-cervical grooves of the carapace are well marked; dorsally, the distance between them is only about one-fifth of the distance from the post-cervical groove to the hinder margin. The median carina is visible throughout the length of the carapace. The second joint of the antennular peduncle, measured dorsally, is fully two-thirds the length of the ultimate joint. The antennal scale (fig. 7) is a little more than three times as long as wide ; the outer margin is somewhat convex and termi- nates in a spine which extends be^'ond the narrow apex of the lamella. The ultimate joint of the mandibular palp varies in length, but is, in all cases, shorter than the greatest width of the basal joint. In the second maxilla the anterior lobe of the internal igio. 1 S. Kemp : Notes on Decapoda. 175 lacinia is slightly broader at the apex than at the base and is a little narrower than the adjacent lobe of the external lacinia. The apex of the endopod is narrow and bears from three to five spines on its external aspect. In the first maxillipede the third joint of the endopod is oval and very nearly twice the length of the second; the basal joint bears five stiff spines on its inner distal margin. The carpus of the first pair of peraeopods is shorter than . the chela and is only a little more than half the length of the merus. In the second pair the chela is seven-eighths the length of the carpus and the dactylus is equal to, or shorter than, the palm. In the third pair the merus and carpus are of the same length; the chela is half, or a little more than half, the length of the carpus and the dactylus is a trifle shorter than the palm. The sixth abdominal somite alone is dorsall}' carinate and all the median tubercles on the abdominal sterna with the exception of the first are blunt and inconspicuous. The apex of the telson is truncate and bears four or five pairs of plumose setae, of which the middle pair is the longest, between the stout marginal spines. The petasma (figs. 5, 6) bears some resemblance to that of Gcn- nadas parvus, but, judging by the dissimilarity which exists in re- gard to the other characters, more especially in the antennal scale and antennular peduncle, it does not seem likely that the two forms are allied to one another in any really close manner. The outstanding lobe on the anterior aspect varies considerably in shape ; it is sometimes pointed apically and reaches as far as the distal margin. I have associated this species with the name of Ivieut.-Colonel Alcock who has given a very accurate description of the thelj^cum {loc. cit., 1901, p. 47, suh '' G. parvus"). His account, which ma}^ be compared with fig. 8, runs as follows : — "The thelycum consists of a horizontal, subtriangular plate or tubercle, placed between the third pair of legs, followed by two transverse bars between the fourth and fifth pairs. The first of these bars is somewhat W-shaped with the posterior notch of the W filled by a tooth in the middle of the anterior border of the second bar." The specimen which Miss Rathbun ' has attributed to Gen- nadas parvus, remarking that the thelycum agrees exactly with Alcock's description, is certainl}?^ quite distinct from the species here described. The true female of Spence Bate's G. parvus, which I have recently discovered in a collection made by Dr. J. Stanley Gardiner, is, in respect of the thelycum, wholh* different both from the present species and from that figured by INIiss Rathbun. 1 Rathbun, Bull. U. S. Fish Comm. for 1903, 1906, p. 907. 176 Records of the Indian Musettni. [Vol. V, Gennadas praecox, sp. nov. (Plate xiii, figs, i — 4.) St. 320. — Off C. Comorin, 7° 23' N., 75° 44' E., 1,053 fathoms. One male, ^2^ mm. The rostral crest is much the same as m the two preceding species, but the dorsal spine is more slender. The antennary and infra-antennary angles are acute, but rather bluntly rounded at the apex ; the branchiostegal spine is minute. The cervical and post- cervical grooves of the carapace are deeply cut; they approach one another very closely in the mid-dorsal line, where the distance between them is scarcely one-sixth the distance from the post- cervical groove to the hinder margin. The mid-dorsal carina runs the whole length of the carapace, but is inconspicuous posteriorly. The second joint of the antennular peduncle, measured dor- sally, is about two-thirds the length of the ultimate segment. The antennal scale (fig. i) is three and a quarter times as long as broad; it is widest basall}- and its outer edge, which is nearh^ straight^ terminates in a small spine which falls far short of the narrow apex of the lamellar portion. The ultimate joint of the mandibular palp is about as long as the greatest width of the penultimate joint. In the second max- illa (fig. 4) the anterior lobe of the internal lacinia is strongly con- stricted behind the apex and is a trifle narrower than the adjacent and similarl^'-constricted lobe of the external lacinia. In the latter lacinia the anterior lobe is full}^ one and a half times the width of the posterior. The third joint of the endopod of the first max- illipede is fully twice the length of the second ; the fourth is ex- tremely minute. Two stift" curved spines are situated on the inner distal margin of the joint. The carpus of the first pair of peraeopods is about the same length as the chela and is two-thirds as long as the merus. In the second pair the chela is three-quarters the length of the carpus and the dactylus is shorter than the palm. The carpus of the third pair is about equal in length to the merus; the chela is onh' a little more than half the length of the carpus and the dactylus is fully as long as the palm. The median spines on the abdominal sterna are blunt and in- conspicuous; the sixth somite alone is dorsally carinate. The telson is squarely truncate at the apex and is furnished with spines and setae as in G. alcocki. The petasma (figs. 2, 3) is most peculiar and utterly unlike that of any species hitherto described. In what appears to be its natural position each of the two halves is roughly triangular in shape and is provided with two long and narrow processes, one on its distal and inferior aspect and one, curved and directed inwards, which arises close to the superior inner margin. In place of the numerous small pleats, which are usually found near the line of connection of the right and left halves, there is, in this instance, a igio.] S. Kemp : Notes on Decapoda. 177 single large fold involving nearly one-third of the whole plate. When this fold is opened out the structure presents the appearance shown in fig. 3. Gennadas sordidus, sp. nov. (Plate xiv, figs, i — 3.) St. 193.— North of the Laccadive Islands, 15° 11' N., 72° 28' 45" E., 931 fathoms. One male, about 20 mm. St. 194. — Off the Laccadive Islands, 13° 47' N., 72° 3' 45" E., 891 fathoms. One male, 24 mm. St. 198.— North-east of Ceylon, 8° 55' N., 81° 17' 30" E., 764 fathoms. One male, i8|^ mm. The rostral crest does not differ appreciably from that of the preceding species. The antennary and infra- antennary angles are acute, the former being bluntly rounded and the latter sharp ; the branchiostegal spine is very small. The distance between the cervical and post-cervical grooves, measured dorsall5^ is less than one-fifth the distance from the post-cervical groove to the hinder margin of the carapace. The mid-dorsal carina is inconspicuous behind the latter groove. The second joint of the antennular peduncle is very short ; measured dorsally, it is less than half the length of the ultimate joint. The antennal scale is widest at the base; it is three times as long as wide and the outer margin terminates in a very small spine which does not extend as far forwards as the lamellar portion. The ultimate joint of the mandibular palp is shorter than the greatest width of the basal joint. In the second maxilla (fig. 3) the anterior lobe of the internal lacinia is short, not wider at the apex than at the base, and is little, if at all, narrower than the adjacent lobe of the external lacinia. In the latter lacinia the anterior lobe is about one and a half times as broad as the poste- rior. The endopod is furnished with three curved spines near the narrow apex. The third joint of the endopod of the first maxillipede is about one and a half times the length of the second and the basal joint bears two or three stiff spines on the inner distal margin. In the first peraeopods the chela , which is about as long as the carpus, is about two-thirds the length of the merus. The chela of the second pair is two-thirds the length of the carpus and the dact5ius is equal to, or a trifle shorter than, the palm. In the third pair the carpus and merus are exactly the same length ; the dact3dus is as long as the ])alm, the whole chela being about half the length of the carpus. The median spines on the abdominal sterna are not prominent ; the sixth somite alone is dorsally carinate. The apex of the telson has much the same form as in G. alcocki. The petasma (figs, i, 2) is a rather complicated structure and is of much the same type as that of G. parvus, to which G. sordidus 178 Records of the Indian Museum. [Vol. V, is evidently very closely allied. The most distinctive character which it possesses is the spoon-shaped portion which is directed forwards from the middle of the distal margin of each lobe. Gennadas scutatus, Bouvier. (Plate xiii, figs. 9, 10.) Gennadas scutatus, Bouvier, Res. Camp. Sci. Monaco, xxxiii, 1908, p. 42, pi. viii. Gennadas scutatus, Kemp, Proc. Zool. Soc. , 1909, p. 727, pi. Ixxv, fig. 2. St. 108.— Off C. Comorin, 7° 4' N., 76° 34' 15" E., 1,043 fath- oms. One male, about 29 mm. St. 109.— Off C. Comorin, y° 1' N., 78° 21' E., 738 fathoms. One male, broken. With the exception of the petasma, these specimens agree closely with the example obtained by the ' Challenger ' in the N. Pacific (Kemp, loc. cit.). They differ from Bouvier's description and figures in the following particulars : — The ultimate joint of the mandibular palp is fulh' as long as the width of the basal joint. In the second maxilla (tig. 9) the anterior lobe of the internal lacinia, though not wider at the apex than at the base, is widety separated from the posterior lobe and is nar- rower than the adjacent lobe of the external lacinia. The third joint of the endopod of the second maxillipede is a trifle wider than in Bouvier's figure. The chelae of the third pair of peraeopods are longer ; in one specimen they are three-fifths the length of the carpus, while in the other they are a trifle shorter, but still con- siderably more than half the length of the carpus. The petasmata of the two specimens are as nearly as possible identical and, considering the great uniformit}^ of outline which these structures usually present, show a considerable amount of divergence from the type. The principal points of difference, as will be seen by comparing fig. 10 with Bouvier's text-figure,' con- cern the development of the large median distal lobe. This is truncate and furnished with a small pointed process on the out- ward side in the type, while in the present specimens it is sharply pointed and the .small process is entirely absent. Gennadas scutatus is now known from the Atlantic (Bouvier), from the Pacific ('Challenger') and from the two localities men- tioned above. When more extensive collections have been made, it will be possible to determine whether, in these widely distant localities, there really exist distinct races of this species, differ- ing from one another in the form of the petasma, or whether there is in this respect merely an exceptionally large range of variation. I Bouvier, BttlL Mas. OcSanog, Monaco, No. 80, 1906, p. 11, fig. 13. igio.] vS. Kemp: Notes on Decapoda. 179 Gennadas bouvieri, Kemp. Gcnnadas bouvieri, Kemp, Pyoc. Zool. Soc, 1909, p. 726, pi. Ixxiv, figs. I — 4; pi. Ixxv, figs. 6 and 7. St. 198.— North-east of Ceylon, 8=* 55' N., 81'' 17' 30" E., 764 fathoms. One female, about 25 mm. This specimen agrees closely with the description of the tj'pe. The only important difference lies in the proportional length of the joints of the third pair of peraeopods, where the merus is only very slightly shorter than the carpus. Except for the fact that no spermatophores are inserted, the thelycum is practically identical with that figured in 1909 (pi. Ixxv, fig. 6). G. bouvieri was found by the 'Challenger' west of Manila and north of New Guinea. Gcnnadas carinatus (vSmith). (Plate xiv, figs. 4 — 9.) Benthesicynius? carinatus, Smith, Rep. U. S. Fish Conun. for 1882, 1884, P- 396, ph X, figs. 6 and 7. Gennadas carinatus, Alcock, Desc. Cat. Ind. Macrura. 1901, p. 46. Gennadas carinatus?, McGilchrist, An)i. Mag. Nat. Hist., March, 1905, p. 236. St, 128.— Oft" C. Comorin, 6° 58' N., 77° 26' 50" E., 902 fathoms. One male, 130 mm. St. 306. — Oft" Travancore, 9° 20' N., 75° 24' E., 930 fathoms. One female, 148 mm. This large species is of great interest and, although the two specimens in the Indian Museum have already been recorded by Alcock and McGilchrist, a fresh description drawn up on the lines of Bouvier's recent work may be found useful. I have followed Alcock in placing the species in the genus Gennadas, though, in point of fact, it is almost exactly intermediate in character between that genus and BoitJiesicvmus. In habit, however, the two genera appear to be quite distinct, for Gennadas, as far as at present known, is entirely pelagic, whereas Benthesi- cynius lives on the bottom. Now in carinatus the joints of several of the appendages are greatly flattened and expanded and closely resemble those of the former genus, and this modification, which is doubtless correlated with a free-swimming existence, has induced me to retain the species in its present position. Alcock has, indeed, suggested that it might be best to regard Gennadas as a subgenus of Benthesicy^nus, but from a practical point of view this cannot be recommended. It must be remem- bered that it is only in the present case that anj^ diificulty arises in allocating the species to one or other genus. i8o Records of the Indian Museuin. [Vol. V, Although the two specimens, on which the following account is based, are very macerated, all the appendages are represented with the exception of the last three pairs of peraeopods. The rostral crest (lig. 4) is elevated well above the dorsal carina of the carapace and differs from that of all other known species of Gennadas in having the superior margin, between the apex and the small dorsal tooth, strongl}^ convex. This margin also appears to lack the usual fringe of setae which occurs in the other species. The antennar}' angle of the carapace is rectangular, but the infra-antennary, as in Bouvier's Gennadas alicei, is entirety absent. The branchiostegal spine is prominent. The cervical and post-cervical grooves are rather strongly marked. Dorsally they are widely separate, the distance between them being at least one half the distance from the post-cervical groove to the posterior margin. The mid-dorsal carina extends the whole length of the carapace but is blunt posteriorly. The e^^es are large and appear to have been deeply pigmented in life ; the conical process on the dorsal surface of the stalk is quite unusually small. The second joint of the antennular peduncle is, measured dorsallv, fully as long as the ultimate segment and is articulated to it by its entire margin and not merely by the inferior edge as in other species of the genus. The dilated portion at the base of the upper flagellum is as long as the two proximal joints of the ped- uncle. The antennal scale is unfortunately incomplete in every case. It was evident^ Httle more than twice as long as wide and the very broad apex of the lamella appears to have extended far bevond the spine which forms the termination of the convex outer margin. The ultimate joint of the mandibular palp (fig. 5) is longer than the greatest width of the basal joint. In the second maxilla (fig. 6) the anterior lobe of the internal lacinia is not wider at the truncate apex than at the base, and is not so broad as the adjacent lobe of the external lacinia. The endopod has almost exactly the same form as in Bcntlicsicymus and bears from ten to fourteen curved spines on its external aspect near the apex. In the first maxillipede (fig. 7) the exopod is provided with a terminal lash as in typical Bcnthcsicymus and the third joint of the endopod is about twice the length of the second. The merus of the second maxillipede (fig. 8) is twice as long as wide and its anterior prolongation (the part which extends forward beyond the insertion of the carpus) is less than one-fifth the entire length of the segment. The dactylus is provided with a single apical spine. In the first pair of peraeopods the carpus, which is about the same length as the chela, is two-thirds the length of the merus. In the second pair the carpus is as long as, or a little shorter than, the merus, the chela is only a trifle more than half the length of the carpus and the dactylus is about as long as the palm. igio.] S. Kemp: Notes on Decapoda. i8i The rudimentary exopods, mentioned by Smith, are visible only in the case of the female specimen. The merus of the second maxillipedes and the ischium and merus of the third maxillipedes and first three pairs of peraeopods are greatly expanded as in typical Gennadas. The third, fourth, fifth and sixth abdominal somites are dorsally carinate. The telson is much longer than in other species of Gennadas, being only a little shorter than the outer uropod. It bears four pairs of lateral spines in its distal third and is sharply pointed apically. The petasma (fig. 9) consists of a pair of simple leaves, as in Boithcsicyinns. The thelycum has been well described by McGilchrist in the following words : ' ' Between the bases of the fourth pair of legs a prominent central papilla stands. Towards this papilla a hairy process passes inwards and backwards from the base of each of the third pair of legs and from the base of each of the fourth pair of legs a tongue-shaped process projects inwards and backwards posterior to the papilla. The papilla thus stands in the centre iDetween the tips of these four processes." Apart from the type, only the two specimens mentioned above are known. Smith's example, which was found off the east coast of the United States, 39° 44' 30" N.. 71° 4' W., in 1,022 fathoms, measures only 74 mm. in length and is thus only about half the size of those from the Arabian Sea. EXPI.ANATION OF PLATE XIII. Gennadas praecox, sp. nov. Fig. I. — Antennal scale, X 8. J J 2. — Right-half of the petasma, folded naturally, X i6. ,, 3. — The same unfolded, X 16. ,, 4. — Second maxilla, X 16. Gennadas alcocki, sp. nov. Fig. 5. — Left-half of the petasma, X 16. ,j 6. — The apex seen from the other side, X 30. ,, 7. — Antennal scale, X 8. ,, 8. — Thelycum, X 16. Gennadas scutatus, Bouvier. Fig. 9. — Part of the second maxilla , X 70. 10. — Left-half of the petasma, X 30. Rec Ind.Mus.. Vol. V, 1910. Plate XIII. l-4.G-ennadas praecox. 5-8.Gennadas alcocki. 9 , 10. Gennadas scutatus. EXPLANATION OF PLATE XIV. Gcjuiadas sordidus, sp. nov. Fig. I. — Left-half of the petasma, X 22. ,, 2. — Apex of the petasma of another specimen, showing the lobes reflected in a different manner. 3. — Second maxilla , X 20. Fig. 4 ,, 5 „ 6 ,, 7 .. 8 Gennadas cari)iatiis (Smith). — The front part of a female specimen seen laterally, X li. — Mandibular palp, X 3. — Second maxilla, X 3|. — First maxillipede, X 3f . — Endopod of the second maxillipede, X 3f. — Right-half of the petasma , X 5^. Rec. Ind.Mus., Vol. V, 1910 l-3.Gennadas sordidus 4'-9. Genriadas carmatus. 'Aulbor's Copy. Cn*-|X— ^ RECORDS of the INDIAN MUSEUM Vol. VI, Part I, No. 2. Notes on Decapoda in the Indian Museum, 11. By 5. KEMP. CALCUTTA MARCH, I9FI. 11. NOTEvS ON DECAPODA IN THE INDIAN M U S E U M . II. — Descriptions of two new Crangonidae with Observa- tions ON THE AIUTUAE AFFINITIES OF THE GeNERA Pontophilus and Philocheras. By Stanley Kemp, B.A., Assistant Superintendent, Indian Museum. (Plate ii.) In the present paper two new species of Crangonidae, one' from New Zealand and the other from the Andaman Islands, are described from material in the Indian Museum. An examination of these species and of others which occur on the coasts of Australia and New Zealand has induced me to reconsider the generic status of Pontophilus and Philocheras, with the result that the distinctions between the two genera are found to be so trivial that the only possible course is to revert to the view expressed by Ortmann in 1895,^ and to classify all the various forms under PontophHus, though it will not be necessary to follow him in placing Aegeon in the same category. So far as I am aware, the sole distinction which can be relied upon for the separation of the two genera rests in the presence or absence of the appendix interna on the endopod of the last four pairs of pleopods, and this, in the two species found on the New Zealand coasts (P. australis, Thomson, and P. chiltoni, sp. nov.), is greatly reduced in size, rudimentary on the fourth pair and entirely missing from the fifth. Consequently, in the case of Crangonidae, the importance of this character seems small in any natural scheme of classification, though in other families of Decapoda, such as the Callianassidae, it affords indications of great systematic value. PONTOPHILUS, Leach. Pontophilus chiltoni,* sp. nov. (Plate ii, figs. 6 — 10.) Among a small sample oi Pontophilus labelled^' New Zealand," and received here many j^ears ago from the Canterbury Museum, two ovigerous females occur, which evidently represent a species 1 Ortmann, Proc. Ac. Nat. Sci. Philadelphia, xlvii, 1895, P- i^^. 2 I take pleasure in associating with this species the name of Dr. Chas. Chil- ton, whose valuable work on the Crustacea of New Zealand is known to every carcinologist. 6 Records of the Indian Museum. [Vol. VI, hitherto undescribed. The other specimens in the same bottle are to be referred to Pontophilus austraiis^^ and as this species is ex- tremel}^ closely allied to the new form, it wih be convenient to express the differences between the two in parallel colnmns— P. australis (Thomson). Rostrum narrow (fig. i). Two mid-dorsal spines of carapace situated close together in anterior third (fig. i). Antennal scale a trifle more than twice as long as wide (fig. 3). Propodus of first peraeopod not narrowed anteriorl}': i.e., as broad behind subchelate termination as at base (fig. 2). vSixth abdominal somite more than one and a half times length of fifth and bearing dorsally a pair of distinct but blunt longitudinal carinae (fig. 5). Apex of telson narrow.^ P. chiltoni, sp. nov Rostrum broad (fig. 6).^ Two mid-dorsal spines of carapace widely separate; pos- terior spine situated exactly in middle of carapace (fig. 6). Antennal scale considerably less than twice as long as wide (fig. 8). Propodus of first peraeopod evidently narrowed anteriorly : i.e., distinctly broader at base than behind subchelate termi- nation (fig. 7). Sixth abdominal somite less than one and a half times length of fifth, with a median longitudinal depression, but without distinct carinae (fig. 10). Apex of telson broader.^ In addition, P. chiltoni is a trifle stouter in build than P. australis, the terminal joint of the fourth pair of peraeopods is a little shorter and broader, and the spinous processes on the postero- inferior margin of the fifth abdominal somite are distinctly blunter. Two specimens, ovigerous fem.ales, 30 and 32 mm. in total length, from New Zealand. (P^egd. Nos. xoa_9z-_3o_) Pontophilus sabscchota,* sp. nov. (Plate ii, figs. 11 — 14.) The general form is short and stout. Measured dorsally, the carapace (including the rostrum) is longer than the first five abdo- minal somites, and its breadth is almost as great as its length. 1 Pontophilus australis (Thomson), Trans. Linn. Soc. London (2), viii, 1903, p. 434, pi. 27, figs. 1—5. 2 In the second specimen the rostrum is a trifle narrower than is shown in this figure, but is still very evidently broader than in P. australis. 3 The distinctions afforded by the comparative length of the telson and uropods, as seen in figs. 5 and 10, cannot be relied upon for differentiating the two species. 4 Hindustani, " sab se chota" : the smallest of all. iQii.] vS. Kemp : Notes on Dccapoda, II. 7 The rostrum is extremely broad and, in dorsal view (fig. 11), is constricted behind the squarely truncate apex ; its distal breadth is about one-third the total length of the carapace. The lateral margins are greatly elevated and form a sort of hood covering the bases of the eye-stalks. The carapace (figs. 11, 12) is sharply carinate in the median line, the carina terminating in a spine a little behind the rostral base. On either side there are three lateral carinae, all of which ate well- defined and are continued as far as the posterior margin. The first of these commences a short distance behind the orbital notch and runs downwards and backwards; it bears no rpines, but is abruptly notched near its middle point. The second lateral carina is more or less parallel with the first, and is continuous anteriorly with the acute orbital angle ; it bears a sharp spine, a trifle in advance of that in the median line, and further back, near the middle of the carapace, a notch similar to, but well in front of, that on the first lateral carina. The third consists of two distinct carinae^ of which the upper is sharp and runs from the apex of the branchio.stegal spine to the m.iddle of the carapace, while the lower, which is less prominent, starts beneath the posterior termination of the upper one and reaches to the hinder margin. The branchiostegal spine is very prominent, and extends a little beyond the apex of the rostrum. In the female the sternal plates of the last three thoracic somites are very broad and form thereof of a chamber, continuous w^ith that between the pleopods, which is used for the accommo- dation of eggs. From the anterior margin of the third thoracic sternum a sharp spine extends forwards as far as the base of the outer maxillipedes. The eyes are well pigmented. The lateral process from the basal joint of the antennular peduncle is rounded anteriorly. The antennal scale (fig. 14^ is broad, little more than one and a half times as long as wide, and its convex outer margin terminates in a minute spine, which does not exceed the apex of the lamella. The third maxillipedes extend beyond the distal end of the scale by the ultimate joint and about one-half of the antepenultimate. The first pair of peraeopods reaches about as far forwards as the third maxillipedes. The merus is very broad, and does not possess the small spine at the distal end of its upper margin^ which occurs in most of the allied species. The second pair is compara- tively stout, and reaches be5'ond the carpus of the first pair ; the ischium is unusually short, and the fingers of the chelae, which are not curved and meet throughout their length when the claw is closed, are twice the length of the palm. There are six gills on either side, as in the Atlantic species. The abdomen, as will be seen from figs. 11 and 12, is rather elaborately sculptured : the third, fourth and fifth somites are carinate, the sixth bicarinate. The endopod of the last four pairs of pleopods (fig. 13) does not possess an appendix interna; it is, however, remarkable for its length, being only a trifle shorter than the exopod. The telson Records of the Indian Musewii. [Vol. VI is sulcate above and very long, extending beyond the distal end of the outer uropods. In addition to two pairs of dorso-lateral spinules, there is another pair defining the outer angles of the narrow apex. Between the two latter spinules there are four long setae. The eggs measure about '51 X "33 mm. in longer and shorter diameter. The above description was drawn up from a single ovigerous female, only 9*3 mm. in length, which was obtained b}^ the Marine Survey at S. Sentinel Island, Andamans (Regd. No. '^V^.) Pontophilus sahsechota is one of the smallest Macrura known. It may easily be distinguished from all species hitherto described by the details of the carination and spinulation of the carapace. The mutual affinities of Poutopliiliis and PhilocJicras. The separation of the genera Pontophilus and Philocheras is almost an impossibility in the case of the species inhabiting Asiatic waters, and, as I have had an opportunity of examining a number of the species which occur in this region, the following notes bearing on the generic status of the forms concerned may be found useful. In addition to those preserved in Calcutta, I have been able, thanks to the good ofiices of Mr. R. Etheridge, Curator of the Australian Museum, to examine the types of three very interesting species described in 1902 by Messrs. Fulton and Grant, and I have also added a few notes, which were kindly supplied me by Dr. W. T. Caiman, concerning vSpence Bate's Crangon intermedins, the only known example of which is preserved in the British Museum. In the N. E. Atlantic the two genera may, with one important exception, be distinguished from one another b}' the use of the following characters : — Pontophilus. Basal process of antennular peduncle sharpl}" pointed dis- tally. First peraeopods with small exopod. Second peraeopods very short, not reaching to distal end of merus of first pair ; chela well-formed with palm of good length ; fingers concave in- ternally, meeting only at tips. Endopod of last four pairs of pleopods only a little shorter than exopod and with appen- dix interna at base. Philocheras. Basal process of antennular peduncle distally truncate or rounded. First peraeopods without exopod. Second peraeopods reaching at least as far as distal end of carpus of first pair ; chela weak with palm very .short; fingers parallel internally, meeting throughout their length. Endopod of last four pairs of pleopods little, if at all, more than half length of exopod and without appendix interna at base. igii.] S. Kemp : Note's on Decapod a, II. 9 According to my own observations, P. spinosiis (Iveach), norvegicus (M. Sars), brevirostris, Smith, gracilis, vSmith and abyssi , Alcock/ agree in possessing the characters of Pontophihts as here defined, while P. echinulaius (M. Sars), irispinosus (Hailstone), bispinosus (Hailstone and Westwood) and obliqwus, Fulton and Grant, are equally typical representatives^ of Philochcras. P. sabseclioia, sp. no v., resembles P/»7of/imrs, except that the endopod of the pleopods is long, only a trifle shorter than the exopod (fig. 13). Dr. Caiman has kindl}" supplied me with the following informa- tion concerning the type of vSpence Bate's Crangoii internicdius ,^ which was found on the coast of S. Australia. The lateral process of the basal joint of the antennular peduncle terminates in a small point at its antero-external angle. There is no exopod at the base of the first pair of peraeopods ; the second pair reaches to the end of the carpus of the first, and the dactylus is more than half the length of the propodus. The endopod of the last four pairs of pleopods does not exceed half the length of the exopod, and does not possess an appendix interna. From this it will be seen that the species is closely allied to typical examples of Philoclicras ; it differs from them only in the shape of the basal process of the antennule, and also, if vSpence Bate's figure is correct, in the form of the chela of the second peraeopods. In the two New Zealand species, P. aiistralis (Thomson) and P. chiltoni, sp. nov., the basal process of the antennular peduncle is sharply pointed anteriorly. There is no exopod on the first pair of peraeopods. The second pair is slender (fig. 9), and reaches to the end of the carpus of the first pair; the palm is of moderate length, but shorter than the fingers, and the latter are only very slightl}^ curved internally. The endopod of the last pair of pleopods is scarceh' half the length of the exopod, and bears a very small appendix interna (fig. 4), which is quite rudimentary on the fourth pair and entirely absent from the fifth. These two species appear to be exactly intermediate in character between the typical examples of Pontophilus and Philo- chcras occurring in European waters. P. victoricnsis, Fulton and Grant,* resembles the New Zealand species in most of the characters just mentioned, but the palm of 1 Alcock's statement (Desc. Cat. Indian Deep-sea Macrura, 1901, p. 114) that ao exopod exists at the base of the first peraeopods in P. gracilis and abyssi is, I think, due to an oversight. 5 1 have not at hand any examples of P. fasciahis (Bell); the characters of this species are, I believe, quite typical of Philocheras. 3 Crangon intermedins , Spence Bate (nee Stimpson), Proc. Zool. Soc. London, 1863, p, 503, pi. xli, fig. 6 = Crangon baiei, Kingsley, noin. nov.. Bull. Essex Inst., xiv, 1882, p. 129. 4 Fulton and Grant, Proc. Roy. Soc. Victoria (n.s.), xv, p. 65, pi. x, fig. 2. 10 R&cords of the Indian Museum. [Vol. VI, the second peraeopods is a trifle shorter, and the appendix interna is well-developed on all the last four pairs of pleopods. P. fiindersi, Fulton and Grant/ is closely similar to P. victori- ensis, but the palm of the second peraeopods is still shorter; the basal process of the antennule is, moreover, rounded anteriorly, and not pointed as in that species. Allied to the above is the Atlantic and Mediterranean species P. sciilptus (Bell), the characters of which are wrongly indicated in m}^ account of the Decapoda Natantia of the coasts of Ireland.* Though included under Philocheras, this species differs from the definition of the genus, as there given, in the possession of a well- developed appendix interna on the last four pairs of pleopods. In all other respects the species bears the closest resemblance to typical Philocheras ; it is the only form occurring in the N. E. Atlantic which shows any character of an intermediate nature. In the table on p. ii an attempt has been made to summarize the foregoing observations. From this it seems sufficiently clear that, failing the discovery of new characters, no basis remains for the retention of two separate genera. It is true that the species ma}' be separated into two groups, divided by the presence or absence of the exopod on the first pair of peraeopods and b}' the comparative length of the second pair, but the evidence afforded by these characters cannot be reconciled with that offered by the appendix interna. The latter character appears to hold such high importance in other groups that it is impossible to ignore it in the present instance. The genus Aegeon, Guerin-Meneville {^= Poufocaris, Spence Bate), which possesses seven C-shaped branchiae is, I believe, quite distinct from the group of species dealt with in this paper. AH the forms here considered appear to have only six gills j'"^ the inferior apices of which are directed backwards. Sixteen species belonging to the genus Pontophilus have been recorded from Asiatic waters. Nine of these have already been mentioned, and are included in the table on p. ii ; the remaining seven are — P. bidentatus (de Haan), in Siebold's Fauna Japonica, Crust., 1849, p. 183, pi. xlv, fig. 14. Japan. 1 Ibid., p. 67, pi. X, fig. 3, 2 Fisheries, Ireland, Sci. Invest., 1908, i [1910], pp. 144, 148. A feature of this species, to which I have drawn special attention, is the presence of a stout spine in the middle of the outer margin of the antennal scale. This is, I believe, found in all British specimens, but, curiously enough, is quite absent in an example from the Mediterranean preserved in the Indian Museum. I leave it to those better situated than myself as regards material to determine whether distinct species exist in these two localities. Both forms possess the appendix interna. o The gill-formula of P. in/ermedius is unknown and that of the three species described by Fulton and Grant could not be determined satisfactorily owing to the poor condition of the type specimens. igii.] S. Kemp : Notes on Decapoda, II. II § pq « w w Q N.E. Atlantic and Mediterranean. N.E. and N.W. Atlantic. N.W. Atlantic. N.W. Atlantic and B. of Bengal. N.W. Atlantic and B. of Bengal. Victoria. N.E. Atlantic and Mediterranean. * Victoria. New Zealand. New Zealand. South Australia. Andaman Islands. Victoria. N.E. Atlantic and Azores. N.E. Atlantic and Mediterranean. N.E. Atlantic. •juasqB Buaa^ui xipuaddy : ; ; • XXXXXX o it •:^joqs spod -03[d JO podopiig[ : : : : : .xxx xx xxxx •§not spodosBjad puooag : : : : :xxx xxxxxxxx < < •spodoaBjad :^sjg uo podoxa ox : : : : ixxxxxxxxxxx a a^Bo -unj:j JO papunoj ssaDOjd IBIn^u^:^uv : : : : : :xx . :xxxxx o < o . M to •^nasajd BnJ3:^ni xipuaddy xxxxx X X X s s :::::: 'Snot spod -oaid JO podopua: •;joits spodoaBjad puooag xxxxxx : : : : :x ■ ■ ■ ' Si!! xxxxx ::'.:::::'.: '. •spodoaBjad :jsig no podoxQ; xxxxx ::::::::::: O •pa^niod ssaoojd jBinnu9:^HV xxxx X X : :x xx : : : : : to ::::::::;::::::: iil;§-.|i|isll ii.il 12 Records of the Indian Museum. [Vol. VI, 191 1.] P. japonicus, Doflein^ Ahhandl. d. kon. hayer. Akad. Wiss., xxi 1902, p. 621, pi. iii; fig. 6, and text-fig., p. 622. Japan. P. carinicauda (Stimpson), Proc. Acad. Nat. Sci. Philadelphia, xii i860, p. 25. HongV P. challengeri , Ortmann, Decap. u. Schizop. -Plankton Exped., 1893 p. 49 = P. gracilis, Spence Bate {nee Smith), Rep. Voy H.M.S. "Challenger," xxiv, Crust. Macr.^ 1888, p. 487 pi. Ixxxvii. Altantic: Tristan da Cunha, Cape Verde Islands Pacific: New Zealand, near Torres Str., near Philippine Islands. P. profundus, Spence Bate, Rep. Voy. H.M.S. '• Challenger," xxiv Crust. Macr., 1888, p. 490, pi. Ixxxviii, fig. i. Off Sydney. P. junceus, Spence Bate, Rep. Voy. H.M.S. " Challenger," xxiv Crust. Macr.. 1888, p. 491, pi. Ixxxviii, figs. 2 — 4. Between Philippine Islands and Borneo. P. modumanuensis , Rathbun, Bull. U. S. Fish. Comm. for 1903 xxiii, pt. iii, 1906, p. 910, text-fig. 63. Hawaiian Islands. There is reason to believe that the last four of these species resemble P. spinosiis and the other typical representatives of the genus in their more important structural features. EXPLANATION OF PLATE II. Pontophilus australis (Thomson). Fig. I. — Carapace of an ovigerous female in dorsal view, X4. ,, 2. — Propodus and dact3^1us of first peraeopods, X8. ,, 3. — Antennal scale^ X 4. ,, 4. — Third pleopod, X8. ,, 5. — Last two abdominal somites and caudal appendages, X4i. Pontophilus cJiiltoni , sp. nov. Fig. 6. — Carapace of an ovigerous female in dorsal view, X 4. ,, 7. — Propodus and dactylus of first peraeopods, X 8. ,, 8. — Antennal scale, X4|^. J, 9. — First and second peraeopods, X4. ,, 10. — Last two abdominal somites and caudal appendages, X 4 J Pontopliilus sabsecJiota, sp. nov. Fig. II. — Dorsal view of the type specimen, X9. ,, 12.— Lateral view of the same, X9. ,, 13- — Third pleopod, X 30. ,, 14. — Antennal scale, X 12. Rec.Ind.Mus,Vol.V1.1911. Plate II. A.C. Chowdha-ry, del. et.Mh: l.-S.Pontophilus australis. S -10 , Pontophilus chiltoni Il-ll", Pontophilus s aLs echota.. Authors Copy. - -"^"fkor'o RECORDS of the INDIAN MUSEUM Vol. VI, Part V, No. 21. Notes on the Occurrence of Jlpus in Eastern Asia. By H. J. WALTON and STANLEY KEMP. C7\LCUTT7V: DECEMBER, 1911. XXI. NOTES ON THE OCCURRENCE OF APUS IN EASTERN ASIA. By Major H. J. Wai^ton, M.D., F.R.C.S., I. M.S., and Stani,ey Kemp. B.A., Assistant Superintendent, Indian Museum. I.— ON THE OCCURRENCE OF APUS, Latreii.i,e, IN THE UNITED PROVINCES OF INDIA. By Major H. J. Wai^ton, M.D., F.R.C.S., I. M.S. Dr. Annandale informs me that the only species of Apus known to occur in India is .4. hiinahyamts, described many years ago by Packard in his • Monograph of Phyllopod Crustacea. ' Vreden- burg records the occurrence of a species of this or an allied genus in Baluchistan, but has not identified the species (Journ. As. Soc. Bengal, 1905, p. 33). The geographical distribution of the genus Apus appears to be imperfectly known. Geoffrey Smith {Camh. Nat. Hist., Crustacea) only refers to species occurring in Europe, North Africa and Central Australia. As mentioned below, I feel confident that a species occurs in North China. It becomes, therefore, a matter of some interest to place on record the fact that an Apus occurs in the plains of India. On March 20th, 1911, the late Major C. J. Robertson Milne, I.M.S., and I found this Phyllopod to be tolerably numerous near the village of Banel, in the Bulandshahr District of the United Prov- inces. The animals occurred in three or four ver}^ small muddy pools formed by leakage from a ' • distributory ' ' of the Upper Ganges Canal. The pools were in fact scarcely more than puddles, the' largest not being more than a couple of yards in dia- meter. Our discovery of Apus was quite a coincidence. About half an hour previously, I had mentioned to Major Milne that I had seen what I believed to have been a species of Apus or Lepidurus at Pekin, about ten years ago; and I remarked that I believed that neither genus occurred in India. When we arrived at the pools we saw some moderately large animals moving about in the mud: on capturing one, I recognized Apus at once. With the aid of some boys we secured about three dozen specimens. The erratic distribution of Aptis has been commented on by several authors, and was borne out b}' the present experience. We only found the animals in a few pools; many adjoining, and appar- ently similar ones containing none. Subsequently for several daj's I searched unsuccessfully for more specimens in other parts of the Bulandshahr District, both in the Ganges Canal and in many pools in its neighbourhood. Considering the conspicuous size of 352 Records of the Indian Museum. [Voi.. VI, the animals, their active movements, and the fact that they occur in shallow pools, one is led to believe that they cannot be very widely distributed in India: otherwise, they would have been found before. Most natives to whom I have shown them do not recognize them at all ; but a few persons have told me that they have seen them before, but only during the " rains.' ' In colour the animals are chiefly a dull olive-green, wdth the shield mottled with dark spots. In life, the long filiform endites of the first thoracic limb and in some animals the abdominal seg- ments, have a decidedly rufous tinge. The average length of 31 specimens, measured from the anterior end of the cephalic shield to the posterior end of the abdomen (not including the f ureal styles) is 33 mm., that of the styles being 35 mm. The maximum measurements are respectively 40 mm. and 41 mm. A very large specimen measures 80 mm. from the anterior end of the shield to the extremities of the furcal styles. The average length of the shield in the mid-line (eleven specimens) is 24 mm. , and its breadth (not flattened out) is 18 mm. Dr. Keilhack (" Siisswasser fauna Deutschlands ") gives 10—30 mm. and 9 — 28 mm. for these latter measurements in German examples of Triops^ {Apus) cancriformis. I have dissected five specimens, all of which were females : this is in harmony with the fact that in Apus and allied genera males are of rare, possibl}^ seasonal, occurrence. The limbs and appendages of my specimens agree very closely with the admir- able description of those of A. cancriformis given by Professor Bourne {Comp. Anat. of Animals, vol. ii) ; and in most other respects of their external structure the animals appear to be quite similar. It is impossible to say without comparison of specimens (which are not available for me) whether this Indian Apus is a new species or not. For the determination of this point I am sending specimens to the Indian Museum. 1 The substitution of the name Triops for the universally known Apus, though it may be justified in the strict letter of the law, is much to be deprecated as being liable to lead to great confusion. — S. K. igii.] S. Kemp : The occurrence of Apus in Asia. 353 II.— NOTES ON MAJOR WALTON'S SPECIMENS AND ON OTHERS FROM KASHMIR WITH A LIST OF PRE- VIOUS RECORDS FROM EASTERN ASIA. By Stanley Kemp, B.A.. Assistant Superintendent, Indian Museum. In addition to the fine specimens of Apus sent to us by Major Walton a nnml^er have been obtained during the present year from Kashmir. For these we are indebted to Mr. T. Bainbrigge Fletcher of the Agricultural Research Institute, Pusa, who re- ceived them from the Settlement Commissioner of Jammu and Kashmir State. When forwarding the specimens the Commissioner remarks that they "occasionally do much damage to rice seedlings in the Banihal ilaka south of the Pir Panjal range at a height of about 6,000 ft. The damage occurs in the first few days of growth only, mainly where the irrigation water is particularly cold, and is greater in a year like the present, when the winter snow-fall is exceptionally heavy and melts late." He also remarks that as far as he is aware it does not occur in the extensive rice cultiva- tion of the Kashmir valley, a region separated from the Banihal district by the Pir Panjal range, in this part from 9,200 to 14,000 ft. in height ; nor does it seem to occur in the lower hills to the south. While the re-discovery of this genus in India in two widely separated localities after a lapse of forty years is of considerable interest, it coincides with our knowledge of its erratic occurrence in other countries. But the statement that Apus has become an agricultural pest in Kashmir calls for further investigation. No males occur in either collection, I have carefully examined Major Walton's specimens and also those from Kashmir and have reached the conclusion that all are specifically identical with the European A. cancriformis. It must however be confessed that this determination is made with no great confidence ; the taxonomy of the Notostraca stands in urgent need of revision and a stud}^ of the literature seems to indicate that the characters used for specific dift'erentiation are few in number and for the most part subject to much variation. There can be little doubt that when the group is monographed a considerable reduction in the numbers of known species will be^ effected. There are, indeed, noticeable distinctions between the speci- mens from Kashmir and those from Bulandshahr ; but it appears probable that these are due merely to differences in biological conditions correlated with altitude and , until the importance of 354 Records of the Indian Museum. [Vol. VI, this factor has been ascertained, it seems best to refrain from further additions to the nomenclature. The Bulandshahr specimens range from 30 to 40 mm. in length excluding the f ureal rami and according to Major Walton the average length of all obtained is 33 mm. In a perfect indivi- dual 30 mm. in length, the length of the shield in the middle line is 22 mm., that of the median carina 16 mm. and that -i the furcal rami 29 mm.^ The long ramus or fifth endite of the first trunk- limbs reaches well be3"ond the posterior extremity of the shield ; it measures 22 "5 mm. in length and is composed of about 58 segments. On comparison the appendages were found to agree very closely with those of specimens of A. cancriformis from Lombardy and with those figured by Lankester"^ from examples obtained at Munich. Prag and Padua. The segments of the first trunk-limbs, while distinctly longer than is indicated in Lankester's figure, are similar to those of the Italian specimens. As regards the number of these segments there again appears to be considerable varia- tion. Lankester gives the number as 80, but Packard^ states there are only 50 and points to the greater number (80) found in A. hi iua lay anus as an important feature of that species. In the Bulandshahr specimens, as mentioned above, the number does not seem to exceed 60 and in this respect direct comparison with the Italian examples in the Museum collection is unfortunately im- possible, for in them these appendages are all broken. In the specific determination of Apodidae great .significance has been attributed to the length of the body as shown by the number of segments uncovered dorsally behind the median notch of the carapace and ventrally behind the last pair of trunk- appendages. Perhaps too much stress has been laid on the former character, for, while it is true that in certain cases it affords a very obvious distinction between species, it seems that it is to some extent dependant on the amount of shrinkage that has taken I)lace during preservation, and a glance at Wolf's figures of Lepidurus viridis, vars. clongatus and setosus* 3delds convincing proof of the great variation of this character within the limits of a single species. In the Bulandshahr specimens from 8 — 11 seg- ments are exposed in dorsal view. The number of segments seen from below behind the last pair of trunk-limbs appears to constitute a more valuable feature ; five such segments are found in Major Walton's specimens and five also occur in the Italian examples of A. cancriformis. Accord- ing to Packard {loc. cit.) there are six in this species, while Braem^ found that in females from the neighbourhood of Breslau the number varied from five to seven. J See also the other niea.surcinents given by Walton, anlii, p. 352. ^ Q J. Micr. Sci (n, s.), xxi, p. 343, pi. xx (1881). 5 Ann. Mag. Nat. Hist. (4). viii, p. 335 (1871). * Wolf, Fauna Sifdwest A ustraliens, iii, If. 9, pp. 267 — 9, text-figs. 11, 13 6 Braein, Zeitschy. Wiss. Zool., Ivi. p. 183 (1893). igii.] S. Kemp : The occurrence of Apus in Asia. 355 The average diameter of the eggs is "49 mm. The Kashmir specimens appear to differ from those found at Bulandshahr only in two respects : — (i) The size is much smaller, the average length of the body in 20 specimens is 20-6 mm. (excluding the furcal rami), the extremes being 15 and 25 mm. (2) The surface of the carapace, when the moisture has been removed, is seen to be covered with fine and short irregular ridges, giving it a wrinkled and reticulate appearance which is specially well-marked in the neigh- bourhood of the shell-gland. In addition the spines on the posterior margin of the carapace appear relatively a trifle larger than in the examples from the United Provinces. Twenty specimens yield the following measurements (in mm.) : — Maximum. Minimum. Total length excluding furcal rami . Length of carapace in median line Int was divided b}' a neck of water extending across the region now occupied by vSumatra and Celebes and the land extension from Madagascar to vS. India reached north to the northern or Asiatic part of that continent. In I^ower and U])per Tertiar}- times New Zealand was completely isolated as it remains ^t the present day ; in the former period India was merely an island, an eastern sea-connection between the ' ^Mediterranean ' and Indo-Paciiic extending across Assam and Burma, while in the latter it approaches the shape which it at present bears. On these theories the explanation of the discontinuous distri- bution of X. C'urvirostris is possible, though it can hardly be said to be very convincing. We must assume that Xiphocaridina curviros- tris evolved from some unknown marine or freshwater ancestor in earl}" Cretaceous or pre-Cretaceous times and remained unchanged until the present da}-. In the Lower Cretaceous period it would have opportunities of spreading to New Zealand on the one hand and to lyower Burma on the other. Subsequently, while becoming isolated in New Zealand it must have persisted in Burma or in the country existing to the west of it until Assam reappeared during the Upper Tertiary period. The existence of Xiphocaridina compyessa both in China and Japan and in Australia seems to show that this species also^ according to Ortmann's theories, must have remained with- out sensible modification for almost as long a period. Every zoologist will readily call to mind other instances tending to a similar conclusion. Although no exactly parallel case of geographical distril)ution seems to be known among freshwater Crustacea, the ]\Iegascolecid Oligochaeta of the sub-family Octochaetiuae afford an instance of a closely similar nature. According to ^lichaelsen (1909) this sub- family is found onh^ in India and New Zealand ' and although no species appear to be common to the two, two genera, Octochactus and Hoplochaetclla, occur in both localities. Michaelsen holds that the only possible interpretation of these facts is that at one period a direct land connection existed be- tween India and New Zealand. He remarks (p. 203) : '' T need not explain to any zoo-geographer that the discontinuation of these two regions of distribution in the Octochaetinae is quite a com- mon matter in geographical distribution, the two regions, New Zealand and India, perhaps together with a third region, Mada- gascar, the home of Howascolex, representing the peripheral parts 1 Michaelsen mentions that another genus, Howascolex, known only from Madagascar, might perhaps also be regarded as a member of this sub-family. 120 Records of the Indian Museum. [Vol. VII, of a circular distril^ution, the internal parts of which have been obliterated by the mighty development of younger and stronger forms, in this case the vigorous genus Pheretima, which, from Burma to New Hebrides in one direction and Japan in another, has suppressed and partly exterminated all other genera of earth- worms, those of its own phylum or sub-family as well as those of other tribes," It is. however, difficult to bring the case of X. curvirostris in line with this view. There is no evidence that A', conipressa repre- sents a 3^oung and vigorous type which has exterminated its near ally in localities lying between Assam and New Zealand ; on the contrary it would rather seem that both species are archaic forms that must have arisen almost simultaneously' and, while it is by no means impossible that Caridina may have suppressed X. curvi- rostris in Eastern Asia, it is difficult to see why the same cause should not have effected its destruction in Assam. The genus Xiphocaridina is unquestionably a very primitive one and it may be predicted that such forms are less liable to evolve varieties, local races or other species than those exhibiting a greater degree of specialization.' That this is so is indeed self- evident, for a primitive form, if it be primitive, must necessarily have existed without considerable modification for a prolonged period and the mere fact that it has done this is an indication that it is less likely to adapt itself to any altered conditions of its environment than is a form which by its very specialization showed that in the past it had given a more ready response to such changes. The full significance of the unchanged condition of A", curvi- rostris is, indeed, only realized when the great range of variation in certain other Atyidae is considered. Caridina nilotica is a species of wide African and Asiatic distribution. Specimens found in Bengal differ in certain measurable features from the type which occurs in Egypt and Dr. de Man has distinguished them under the name of C. nilotica var. bengalensis. Among other varieties of the same species it agrees most nearly with var. gracilipes found in Celebes and Salayer Is. Even within the limits of India and Ceylon, however, the form exhibits a most remarkable tendency to split into races, and series of specimens from Calcutta, Madras, Tuticorin, Ceylon and the Andamans each seem to possess its own particular characteristics. I Pocock {1889) has described several species very closely allied to Xif^hocaris elongata ; but subsequent authors have preferred to regard them merely as varieties. I am, however, of the opinion that these forms are not deserving even of varietal recognition and believe that the suggestion which Pocock himself made, that they only represent stages in the growth of a single species, is likely to prove true. The rostra of large specimens of Xiphocaridina curvirostiis are as a rule relatively shorter than in smaller examples, and this is also the case with several species of Caridina. In the.se instances, however, the variation has not nearly so great a range as in X. elongata. On the other hand there appears to be some evidence that two distinct races of A', compressa exist on Norfolk Is. (see Thomson 1903, p. 449, and Grant and McCuUoch, 1907, p. 151). I9I2.J S. Kemp : Notes on Dccapoda. 121 REFERENCES. Bouvier, E. 'L,., 1905. — Observations nouvelles sur les Crevettes de la famille des Atyides. — Bull. Set. France et Bclgique, xxxix, p. 57. J, 1909a. — Sur I'origine et devolution des Crevettes d'eau douce de la famille des Atyides. — C. R. Acad. Sci., p. 1727. J, 19096. — Les Crevettes d'eau douce de la famille des Atyides qui se trouvent dans Tile de Cuba.— Bull. Miis. d'Hist. Nat , P- 329 Grant, F. E . and McCuUoch, A. R. , 1907. — Decapod Crustacea from Norfolk Island. — Proc. Linn. Soc. N. S. W., xxxii, p. 156. Hay, W. P., 1902. — Observations on the Crustacean Fauna of the region about Mammoth Cave, Ken- tucky.— Proc. U. S. Nat. Mus., xxv, p. 223. Heller, C, 1862. — Neue Crustaceean ges, d. R. R. fregatte ' Nov- ara'. — Verhandl. Zool.-Bot.^ Gesellsch. Wien, xii, p. 525. ,, 1865. — Reise der Oesterfregatte ' Novara.' Crustacea. p. 105. de Man, J. G. , 1908. — On Caridina nilotica (Roux) and its varie- • : ties. — Rec. Ind. Mas., II, p 255. Michaelsen, W., 1909. — The Oligochaeta of India, Nepal, Cejdon, Burma and the Andaman Islands. — Mem. Ind. Mits., I, p. 103. Miers, E. J., 1876. — Catalogue of the stalk- and sessile-eyed Crustacea of New Zealand (London), p. 78. Ortmann, A. E., 1895 — A study of the systematic and geogra- phical distribution of the Decapod family Atyidae, Kingsley. — Pro. Acad. Nat. Sci. Philad., 1894, p. 397. ,, 1902. — The geographical distribution of fresh- water Decapods and its bearing upon Ancient Geography. — Proc. Amer. Phil. Soc, xli, p. 267. Pocock, R. I., 1889. — Contributions to our knowledgt of the Crus- tacea of Dominica. — Ann. Mag. Nat. Hist. (6), iii, p. 6. Thomson, G. M., 1879. — New Zealand Crustacea, with descriptions of new species. — Trans. N.Z. Inst, for 1878, xi, p. 231. ,, 1903. — On the New Zealand Phyllobranchiate Crustacea-Macrura. — Trans. Linn. Soc. London (2) Zool., viii, p. 433. Author's Copy. RECORDS of the INDIAN MUSEUM Vol. VIII, Pari III, No. 20. ZOOLOGICAL RESULTS OF THE ABOR EXPEDITION, 1911-12. Crustacea Decapoda. By 5. W. KEMP. C7\LCUTT7\: SEPTEMBER, 1913. Vi'f'il m\n'^< XX. CRUSTACEA DECAPOD A. By Stanley Kemp, B.A., Assistant Superintendent, Indian Museum. (Plates xvii — xxi.) In the present report twelve different forms of Decapod Crus- taceans are recorded, viz. : — Potamon {Potamisciis) decourcyi, sp. nov. ,, aborense, sp. nov. ,, obliteratuin, sp. nov. [Geotelphusn) adiatretum, Alcock. ,, ,, var. lophocarpus , nov. ,, siiperciliosHin, sp. nov. {AcantJwtelphusa) feae, de Man. Paratelphiisa {Barytelphii^a) harpax, Alcock. Palacmon hendersoni, de Man. Caridina weberi, de Man, var. ,, excavata, sp. nov. ,, Jiodgarti, sp. nov. One of the species, Potamon {Potamiscus) obliteratuniy was found by Mr. F. H. Gravel^^ in the Dawna Hills on the Burmo- Siamese frontier, and is included here in order to render more com- plete the account of the subgenus to which it belongs. Of the remainder, six are to be regarded as true hill forms, having been found in the small mountain streams draining into the Dihang river, while five, Potamon (Acanthotelphnsa) feae, Paratelphiisa [Bary- telphiisa) harpax and the three species of Caridina were found at the base of the hills and in the Brahmaputra valley. No less than seven of the eleven Abor forms appear to have been undescribed hitherto, and the collection is, in consequence, of but little assistance in determining the geographical relation- ships of the fauna. The subgenus Potamiscus, as far as is at present known, extends from Rajputana, Nepal and Darjiling to Burma and has been found at Cachar in Assam, while Potamon {Gcotelphusa) adiatrctum has been recorded from the Dafla country, from the Khakyen Hills and from :\Ioulmein. Potamon {Acanihotelphusa) feae, described from the Upper Irrawaddy, seems to be not uncom- mon in Assam north of the Brahmaputra, and Paratelphusa {Barytelphiisa) harpax is a species of wide distribution in north- 290 Records of the Indian Museum. [Vol. \^III, east India. Palaemon hendersoni is known from Darjiling and the border of the Southern Shan States. Caridina weberi, which appears to have a very wide distribution in India, Burma and Malaysia, is represented in the Brahmaputra valley by a race which will in all probability prove to have a definite geographical signi- ficance. The collections in the Indian Museum indicate that Caridina hodgarti extends along the base of the Himalayas from the Tista and Mahananda rivers eastwards to the Abor country. Of the new forms which are described the most interesting appear to be Caridina excavata and C. hodgarti, which, in the reduced number of their epipods differ from all species of the genus in which such details have received attention. In a previ- ous paper ^ I have remarked on the presence of Xiphocaridina curvirostris , a primitive form hitherto known only from New Zea- land, in the Upper Brahmaputra valley, and the existence of these two aberrant species of Caridina suggests that the Atyid fauna of N.-E. India is likely to prove of exceptional interest. It need hardly be pointed out that the description of the crabs noticed in this paper would have been almost impossible had it not been for Alcock's comprehensive memoir on the Indian Potamonidae. On the species of Geotelphitsa obtained in the Abor country many examples of a Temnocephalid were found. These haVe been identified by Mr. F. H. Gravely as Temnocephala semperi, Weber (see p. 229 of this volume). Moreover, certain eggs found in the gill- chambers of Caridina, on comparison with those found in a simi- lar situation in other parts of India, afford evidence of the exist- ence of Caridinicola '^ in the Brahmaputra valley. For assistance in making collections both of Decapoda and of other groups I am under a great debt of gratitude to the Officers of the 32nd Sikh Pioneers. To them, and in particular to Capt. the Hon. M. de Courcy, I have to express my thanks. The type specimens of the new species are preserved in the Indian Museum Family POTAMONIDAE. Sub-family POT A MONINA E. Genus Potamon, Savign3\ Sub-genus Potamiscus, Alcock. The sub-genus Potamiscus was instituted by Alcock to receive those species of Potamon in which the flagellum of the exopod of the outer maxillipedes is absent or vestigial. It is probable that several species of Potamonidae already described really belong to this sub-genus, but the character has been overlooked by the majority of authors, and the confusion is increased bv the fact I Rec. Ind. Mus., Vlf, p. ixn, (iqia). ■^ Caridivicola: a genus belonging to the Temuocephaloid family .'^ciitaric!- lidae (see Aniuindale. Rec Ind. Mus., VTT, p. 24'^, 1912). igi3-] Stani,ey Kemp ; Crustacea Decapoda. 291 that it is only since the pubHcation of Alcock's memoir that it has been possible to separate the sub-families Potamoninae and Gecarcinucinae in a satisfactory manner. The classification of the great majority of the known species of the family will have to be revised in the light of Alcock's work. It might, indeed, be argued that the species allocated to Pota- misciis do not form a natural group and that the character used for distinguishing the sub-genus is one of doubtful value, more especially in view of the fact that the exopodite of the outer max- illipede shows varying stages of degeneration in Phricoteiphusa and GlobitelpIiHsa, sub-genera of the Gecarcinucinae, and that in one of the specimens of a new species of Potamiscus, described below, the lash of the exopod is well developed on both sides, though quite vestigial in the other six examples. Two undescribed species of Potamiscus were obtained in the Abor country and another very remarkable form, also hitherto unknown, has recently been found by Mr. F. H. Gravely in the Dawna Hills. Excluding P. tuniidulum , Alcock, concerning which additional information is still lacking, five representatives of the sub-genus are now known from India. These fall into two very distinct groups. One, which comprises P. annandalei and P. decoiircyi, shows clear afjfinities with Pota- mon, S.S., while the relationships of the three allied forms included in the second group are much less easy to trace. In course of time it may be necessary to restrict the sub-genus to this group, with P. sikkimense, Rathbun, as type, though it will then be very difficult to frame a satisfactory diagnosis which will exclude P. annandalei and its ally. For the present it is not proposed to make any alteration of the kind. Alcock's classification has at least the great merit of convenience, no small advantage in a group presenting such diffi- culties as do the Potamonidae, and until the extra-Indian species have been classified on the lines which he has advocated, such ques- tions as the mutual relationships of the different sub-genera are best left untouched. The five species may be tabulated as follows : — I. Post-orbital crests sharp-edged and undermined. a. Post-orbital crests not sepa- rated from epigastric crests and continued as a well-defin- ed ridge to the blunt epibran- chial tooth ; crenulate ante- rolateral margin of carapace not sharply pinched off from the general surface . . annandalei, Ale. h. Post-orbital crests separated from epigastric crests by a groove and broken into tuber- 292 Records of the Indian Museum. [Vol. VIII, cles in the vicinity of the small but acute epibranchial tooth ; crenulate antero-late- ral margin sharply pinched off from the general surface decourcyi, sp. nov. II. Post-orbital crests not sharp-edged or undermined, but merged to some extent in the large rugosities of the anterior part of the carapace. a. Carapace feebly convex fore and aft ; crenulate antero- lateral margin well defined, but not strongly curved inwards; a very small and inconspicuous gap in the margin anterior to the obso- lete epibranchial tooth b. Carapace strongly convex fore and aft; crenulate antero- lateral margin well defined and strongly curved in- wards; a deep gap in the margin anterior to the large blunt epibranchial tooth . . aborense, sp. nov. c. Carapace strongly convex fore and aft ; crenulate antero- lateral margin obsolete, de- fined merely by a few isola- ted tubercles behind the small but acute epibranchial tooth; a small nick in the margin anterior to the latter obliteratum, sp. nov. sikkimense, Rathbun. Potamon (Potamiscus) decourcyi, sp. nov. (Plate xvii, figs. 1-3.) The length of the carapace slightly exceeds three quarters of the breadth and its depth is rather less than half its breadth ; it is decidedly convex fore and aft and slightly so from side to side. The surface is pitted and a little roughened. The antero-lateral portions are strongly tuberculo-rugose, as are also, but to a less marked extent, the anterior regions behind the epigastric and post- orbital crests. On the side walls are fine oblique striae which pass across the postero-lateral border. The cervical groove is well marked, though not deeply graven, where it defines the mesogastric area ; but its lateral continuations towards the orbits are almost entirely or entirely suppressed. No trace of them exists in a very large male, but they are just percep- tible as very faint and extremely shallow depressions in the younger I9I3-] Stani^ey Kemp : Crustacea Decapoda. 293 examples. The fore lobe of the mesogastric areola is well defined and the median groove is continued, though not always very clearly, almost to the margin of the front. The epigastric and post-orbital crests are sharp and distinct. The epigastric crests are narrow and are separated from the post- orbitals b}' well-defined grooves ; though considerably in advance of the post-orbital crests in the middle line, they slope away on either side and in conjunction with these crests form a common curve across the anterior portion of the carapace. The post-orbital crest is sharply cut and trenchant up to the point where the cervical groove would cut it, if it were defined, but beyond this it is broken up into a number of sharp tubercles (fig. i). The front in adults is much less than one-third the breadth of the carapace ; in small individuals about one-third. Immediately behind and parallel with its edge it bears a bilobed eminence which in dorsal view almost or quite conceals the margin. In this respect the species resembles Potamon pealianum, but the eminences are not quite so pronounced. The edge is sometimes very feebly bilobed when seen from in front. In the smaller specimens there is only a faint indication of a gap between the upper and lower borders of the orbit ; this feature, however, is very strongly developed in the adult male. The antero- lateral borders are sharply pinched off from the carapace, strongly crenulate and well arched, and the epibranchial tooth is well deve- loped. In the abdomen of the adult male (fig. 3) the sixth segment is twice as broad as long and the seventh a little more than three quarters as long as broad. The mandibular palp is simple. The flagellum of the exopo- dite of the external maxillipedes is vestigial in six specimens (fig. 2), but moderately developed in the seventh (a small example). The merus of the endopod is nearly as long as broad. The chelipedes are almost or quite equal in all the specimens ex- amined. The external surfaces of the merus, carpus and propodus are squami-rugose ; the spine at the inner angle of the carpus is strong and sharp The fingers are as long as the palm, pitted in the large example, both pitted and fluted in the smaller individuals. The upper border of the propodus bears vesiculoas granules, some of which are also found at the base of the dactylus. The dact^di of the walking legs are longer than their propodi : in the two middle pairs the propodus is rather more than two and a half times as long as broad. In an adult male, the type specimen, the carapace is 63 mm. broad, 49 mm. long and 29 mm. deep. In the next largest speci- men, also a male, the breadth of the carapace is 26 mm., its length 20 mm. and its depth 11 '5 mm. The species which bear the closest resemblance to Potamon decourcyi appear to be Potamon [Potamon) pealianum, Wood-Mason, and Potamon {Potamiscus) annandalei, Alcock. From the former it differs in the total suppression of the cervical groove, in the 2QA Records of the Indian Museum. [Vol. VIII, marked separation of the epigastric and post-orbital crests and in the vestigial condition of the llagellum of the outer maxillipedes. From the latter it is distinguished by the much greater rugosity of the antero-lateral portions of the carapace, by the more strongly arched and better defined antero-lateral borders, by the narrower epigastric crests and by the deep groove which separates them from the postorbitals. In P. annandalei the post-orbital crests are continued sharply and uninterruptedly to the blunt epibranchial tooth, whereas in P. decourcyi they are broken up into tubercles external to the point where the cervical groove would, had it existed, have cut them. The epibranchial tooth is moreover much sharper in the present species. The large male specimen was obtained for me by Capt. the Hon. M. W. R. de Courcy (Regd. no. ~, type) in the Sirpo valley near Renging. The other examples were taken at Rotung (^), at a point a few miles south of Kebang (^'), and on the banks of the Siyom R. below Debuk Damda ('^). All were found under stones in small hill streams at altitudes of between looo and 1500 ft. Potamon (Potamiscus) aborense, sp. nov. (Plate xviii, figs. 4, 5.) This species differs conspicuously from the preceding and from P. annandalei in that the post-orbital crests are not sharply cut and prominent, but are merged to a great extent in the rugosi- ties of the carapace. Its nearest allies are P. sikkimense, Rathbun, and P. obliteratum , sp. nov. The length of the carapace is about five-sixths its greatest V)readth and the depth is about half the breadth. The carapace is much more convex fore and aft than in P. sikkimense and is slightly but decidedly convex from side to side. The anterior and antero-lateral parts of the carapace are very strongly rugose (fig. 4), the whole dorsal surface is pitted and there are well-marked oblique striae on the side-walls which pass across the postero- lateral borders. The cervical groove is distinct where it defines the mesogastric area, but thence onwards to the post-orbital crests is obsolete, its course being only discerned with the greatest difficulty. The epigastric and post-orbital crests, as in P. sikkimense, are not distinctly separated from one another and form a common curve. The crests are not sharp and salient but are to a great extent merged in the large and conspicuous rugosities of the an- terior part of the carapace, this is more particularly the case with the post-orbitals. The position of the epibranchial tooth is marked by a strong blunt angular lobe (fig, 4) of a far more evident nature than in P. sikkimense (fig. 8) — a lobe the prominence of which is greatly emphasized by the large gap which separates it from the outer orbital angle. In P. sikkitnense, moreover, the post- I9I3'] STANI.EY Kemp : Crustacea Decaf oda. 295 orbital crest near the lateral border is faint and the dorsal surface in these regions is, except for the rugosities, smoothly curved from the orbit backwards. In P. ahorense, however, the surface in the neighbourhood of the outer orbital angle is situated at a much lower level than the lateral portions behind the post-orbital crest, the latter being in this part precipitous and becoming steeper and more strongly emphasized the nearer it approaches the epibran- chial lobe. It is in the mutual relations of the surface of the cara- pace in the neighbourhood of the epibranchial lobe and the orbit that the readiest distinctions between the two species are to be found {cf. figs. 4 and 8). Behind the epibranchial lobe the antero-lateral margin is de- fined by a crenulate ridge which is relatively much shorter and curves inwards further and more abruptly than in P. sikkiniense. The front is deflexed, a trifle more than a third the breadth of the carapace, and the area between its margin and the epigas- tric crests is tuberculo-rugose. Posteriorly the whole carapace is more definitely narrowed than in the allied species, or rather, appears to be so, because the lateral parts of the dorsal surface slope downwards somewhat sharply , leaving only a trifle more than one-third of the actual breadth on the same level as the median horizontal line. The distinction in this respect between the present species and P. obliteratum is very marked. The antepenultimate abdominal segment of the male is shorter than the penultimate (fig. 5), and in this particular P. ahorense resembles the Nepalese examples of P. sikkiniense recorded by Alcock in his Catalogue as P. sikkiniense var. (fig. 6). In t^^pical P. sikkimense the antepenultimate segment is longer than the penultimate (fig. 7). The terminal segment of the mandibular palp is simple. The merus of the external maxillipedes is a trifle broader than long, and in no case is there a vestige of a flagellum on the exopod. The chelipedes are equal in the adult female, but markedly unequal in males of similar dimensions ; they are if anything slighth^ smoother than in the allied species. The spine at the inner angle of the carpus is sharp and the fingers are almost as long as the palm, pitted, but not fluted, and between them when the claw is closed there is no appreciable gap. In adult males the palm of the larger claw is strongly inflated, more so than in P. sikkhnense. The legs are decidedly more slender than in P. sikkiniense and the propodus of the penultimate pair is more than two and a half times as long as broad. The three specimens in the collection are of closely similar size. The breadth of the carapace varies from 17 to 18 mm., the length from 14 to 15 mm. and the depth from 8-5 to 9*5 mm. In life two of the examples were rather conspicuously mottled with deep brown on a pale brown or olivaceous ground, the colouring being particularly noticeable on the side walls of the carapace. The female ic ovigerous and carries a number of eggs, in life of a 296 Records of the Indian Museum. [Voi,. VIII, bright red colour, averaging 2*4 X 2 mm. in longer and shorter diameter. P. aborense appears to be rare in the Abor country, but as all the specimens were found under stones in dry situations it may be that the species has habits different from the majority of forms obtained in the country and this perhaps accounts for its apparent scarcity. All three type-specimens come from the vicinity of Rotung at altitudes of between 1000 and 1300 ft ; one Cu^) was found at no great distance from the Egar stream ; another, the ovigerous fe- male (^), was taken in March from a short burrow with a slightl}' enlarged terminal chamber behind a large stone on a steep hill- side; the remaining example was obtained by Capt. de Courcy when cutting a road between Rotung and the Sireng stream (^). Potamon (Potamiscus) obliteratum, sp. nov. (Plate xviii, figs. 9, 9a.) I take this opportunity of describing a very fine species of Potamiscus obtained recently by Mr. F. H. Gravely in the Dawna Hills. In most cases I would hesitate to give an account of a species of Potamonid represented, as in the present instance, only by a single individual ; but the specimen is in several respects highly peculiar and this fact, together with the circumstance that two other new species of the sub-genus are described in the present paper, may perhaps be held to justify its inclusion. The individual is a female with the carapace 19 mm. long, 23"5 mm. broad and 13 mm. deep; it is thus proportionately slightly deeper even than in P. aborense. The carapace (fig. 9) is strongly and evenly convex fore and aft and slighth' so across its greatest breadth, and everywhere on its dorsal surface it is rather coarsely pitted. Seen from above it is very noticeably quadrate in shape. The sides of the carapace are, indeed, less convergent posteriorly than in the allied species ; but the principal reason of its square appear- ance is that the postero-lateral portions do not slope away ob- liquely to the bases of the last two pairs of walking legs, as in P. sikkimense and aborense^ but are inflated and have the lateral walls abruptly declivous. The antero-lateral portions of the carapace are strongly rugose and a number of prominent ridges and tubercles obscure the post- orbital and epigastric crests. The frontal surface in advance of the latter is sharply tuberculous. The cervical groove is deeply cut where it defines the posterior part of the mesogastric lobe and with its lateral backward continu- ations forms a well-defined figure in the form of an H . The course of its anterior branches towards the post-orbital crests can onh' be traced with great diihculty. 1913' J Stanley Kemp : Crustacea Decapoda. 297 The epigastric crests are a little in advance of the post-orbitals and are separated from them b^^ a distinct furrow : both are ob- scured by large rugae. The post-orbital crests break into tubercles in the vicinity of the epibranchial tooth and, as in P. aborense, the surface in front of them is situated at a much lower level than that behind them. The front is square-cut, not very strongly deflexed and occu- pies about one-third of the greatest breadth of the carapace. The outer orbital angle is acute and beneath it there is no notch in the lower border. The epibranchial tooth is small, but acute, and is separated by a sharp nick from the margin in front of it. The antero-lateral margin is for the most part rounded oE ; the usual crest is obsolete and is represented merely by a few tubercles in the immediate neighbourhood of the epibranchial tooth (fig. 9). This peculiar feature at once distinguishes P. ohliteyaUwi from every other Indian species of the genus Potamon. The side walls of the carapace bear short oblique rows of tubercles which, posteriorly, take the form of ridges and pass across the border to the dorsal surface. The mandibular palp is simple. The outer maxillipedes along with the adjacent parts of the carapace and all the segments of the walking legs bear coarse, scanty, yellowish hairs. The ischium of the outer maxillipedes is, as usual, deeply grooved in a longitu- dinal direction. The merus is about as long as broad. The right exopod bears a short and rudimentary flagellum (fig. qa) ; but of this, on the other side no vestige can be found. The chelipedes in the single female specimen are slightl}^ unequal and are rather more strongly tuberculate than in the two allied species. The carpal spine is long and slender. The palm of the chela is somewhat inflated ; on its dorsal surface tubercles are conspicuous and a few of these extend on to the base of the dactylus. The fingers are grooved and pitted; when the claw is closed their tips are crossed and no appreciable gap remains between them. The walking legs are long and slender, those of the second pair, which are the longest, measuring 46 mm. The propodus of this limb is two and three quarter times as long as broad and the dactylus is as long as the propodus and half the carpus. Though the evidence afforded by the flagellum on the exopod of the outer maxillipedes is somewhat inconclusive, the affinities of this species are clearh^ with P. aborense and P. sikkimense from both of which, as from all other Indian species of the genus, it is readily distinguished by the obliteration of the antero-lateral crest of the carapace. The single type specimen was obtained by Mr. F. H. Gravely in November, 1911, at Sukh on the E. side of the Dawna Hills near the Burmo-Siamese frontier. It was found in a log of rotten wood lying by the roadside at an altitude of about 2100 ft. (Regd. no. 8147\ in /• 298 Records oj the Indian Museuni. [Vol,. \'III, Sub-genus Geotelphusa, vStiinpson. Potamon (Geotelphusa) adiatretum, Alcock. (Plate xviii, figs. 10-12.) 1910. Potamon {Geotelphusa) adiatretum, Alcock, Cat. Indian Decapod Crust., pt. I, fasc. ii, p. 59, pi. iii, fig. ii. This species has hitherto been known from four specimens only: the type, which is said to have come from Moulmein, an individual from the Khakyen Hills and two examples found by Col. Godwin-Austen in the Dafla country. On critical comparison the following differences are found between the Abor specimens and the type: — The surface of the carapace in the former is more distinctly pitted, the frontal and post- orbital regions are a little less strongly deflexed (fig. 10), the cervical groove where it defines the mesogastric area is wider and more deeply graven, the crenulate antero-lateral margin of the carapace is better defined and the spine at the inner angle of the carpal segment of the chelipede is shorter (fig. 12). In respect of the prominence of the antero-lateral margin , the specimens agree much more closely with the Dafla examples than with the type. In course of time it will perhaps be possible to separate one or more geographical races of the species, but this can only be done satisfactorily when a good series of Burmese specimens is available. In the collection, which comprises fourteen specimens, are several adult males. In these the chelipedes are markedly unequal and in the larger one the fingers are both very strongly curved and meet only at the tip, leaving a huge gap between them when the claw is closed. The number of teeth with which the fingers are armed is very variable. In the oldest specimens, in which the gape is widest, each finger bears as a rule a single tooth near the middle of its inner margin. In rather less well-developed individuals these teeth are also found, with, in addition, others between them and the apex of the claw (fig. 11). In full-grown males the last abdominal segment is a trifle wider than long, rounded at the apex, and as a rule with sinuous lateral margins. In the largest specimen the carapace is 2T mm. in breadth and 13 mm. in length. All the specimens were found under stones in small streams running into the Dihang river or its tributaries at altitudes of be- tween 900 and 2000 ft. The precise data are as follows: — Jan. 13th, 1912. Five specimens, 3d» and 2 9 (Regd. no. ^), from a stream on the left bank of the Dihang R. near Yembung. Jan. 17th, 1912. One male, with symbiotic Temnocephalidae, from the Yembung river (~^|'). I9I3-] StanIvEy Kemp : Crustacea Decapoda. 299 Feb. ist, 1912, Three specimens, i cf and 2 $ , with sym- biotic TemnocephaUdae, from a small stream flowing into the Siyom R. below Debuk Damda C^). Feb. 5th to loth, 1912. Five specimens, 3 cf and 2 9 , from a stream between Renging and Upper Renging, collected by Capt. de Courcy and Mr. I. Burn Murdoch C""—). Var. lophocarpus, nov. (Plate xviii, figs. 13, 14.) Thirty-five additional specimens of P. adiatrekiin are distin- guished from the preceding by characters of sufficient importance to merit varietal recognition. In general facies these examples bear an exceedingly close resemblance to the others. The form of the carapace is identical and differs in the features already noted from the type of P. adiatrc- tum. Examined with a lens, the same pitting is observed, but the surface is dull and does not present the polished appearance which characterizes the majority of the typical specimens. It is, however, in the structure of the chelipedes that the most distinctive varietal differences are to be found. In the var. lopho- carpus no trace whatever remains of the spine at the inner angle of the carpus (fig. 14) and, were it not that this spine is reduced in size in the Abor examples of P. adiatretnm (fig. 12), this charac- ter alone might be held sufficient for specific differentiation. In the variety also a tuft of coarse hairs, entirely absent in the case of the other specimens, springs from the antero-internal face of the carpus, i.e. the portion on which the palm of the chela abuts when the limb is flexed. In addition, short hairs of a simi- lar nature are to be found round the base of the dactylus and at the proximal end of the inner margins of both fingers (fig. 13). These hairs are scanty or, in rare instances, wholly missing in some of the largest individuals, but it may, I think, be assumed that their absence in these cases is due solely to mechanical agencies. The eggs of an ovigerous female were in life of a bright red colour. To specialized local races in which the geographical factor can be successfully demonstrated the term ' sub-species ' is perhaps more properly applicable; but as the term ' variety ' has frequently been used with a geographical significance in the case of fresh- water crabs, it should be noted that all the evidence available with reference to the var. lophocarpus negatives the view that it is a localized race. Although the two forms of the species were not actually found together, the localities in which one or other occur- red have no precise correlation with either horizontal or vertical distribution: the variety was found at a place exactly inter- mediate between others in which only the typical form was taken. The specimens were found in hill streams at an elevation of 600-2000 ft. above sea-level. 300 Records of the Indian Museum. [Voi.. VIII, Dec. 31st, 191 1. One male from Upper Rotung, collected by Capt. de Courcy (Regd. no. ^). Jan. 9th, 1912. Three specimens, one & and two 9 , from the Egar stream between Renging and Rotung (^--). Jan. loth, 1912. Three specimens, one & and two 9 , from the Lalek stream near Renging (^^). Feb. 6th-i2th, 19 12. Two males from the neighbourhood of Rotung, collected by Capt. de Courcy (^). Feb. nth, 1912. Sixteen specimens, nine & and seven 9 , some with symbiotic Temnocephalidae, in small streams between two and three miles S. of Yembung (^-^, types). March 21st, 1912. Six specimens, five & and one 9 , in the Sirpo valley between Janakmukh and Renging (^)- March 26th, 1912. Two males in a stream near Balek (^^). Potamon (Geotelphusa) superciliosum, sp. nov. (Plate xviii, figs. 15-18.) This species is allied to P. adiatretum but differs in the follow- ing particulars : — 1. The carapace has much the same proportions but the front is less deflexed and posteriorly the surface is slightly flatter, with the divergent branches of the cervical groove on either side of the mesogastric area more conspicuous. 2. The epigastric and post-orbital crests are well defined and separated in most cases by a rather definite groove. The post-orbital crests arc specially prominent and exist as a thin but salient ridge which disappears before reaching the lateral margin (fig. 15). 3. In young specimens the epigastric and post-orbital crests and the surface in the vicinity of the antero-lateral margin are finely rugose, and the oblique wrinkles on the side walls of the carapace are much more conspicuous. In very large examples the rugosity of the crests is diminished though traces of it are always found near the antero-lateral margin. 4. The epibranchial tooth, wholly absent in P. adiatretum, is represented by a small and inconspicuous nick in the finely crenulate antero-lateral ridge, the latter being sharper and better defined even than in the Abor specimens of the preceding species (fig. 16). 5. There is, as in P. adiairctuui, no trace of an external orbital tooth, but the lower border of the orbit does not run quite flush into the upper border, the two margins joining at slightly dift'erent levels. In young specimens the outer surfaces of the carpus and chela are strongly pitted, but statcely any trace of this remains in adult I9I3-] StanIvEy Kemp : Crustacea Decapoda. 301 males. The spine at the inner angle of the carpus is strong and sharp (fig. 18) and is much better developed than in the Abor ex- amples of P. adiatretum. The fingers of the chela are grooved. In adult males the chelipedes are very unequal and, as in P. adia- tretum, the fingers of the larger claw when closed leave between them a huge gap, meeting only at the tips (fig. 17). The teeth on the fingers appear to be very variable in number and position and the tufts of hairs found in P. adiatretum var. lophocarpus are en- tirely absent. The mandibular palp is simple. The merus of the outer maxillipedes is much broader than long and its anterior margin is rather deeply concave ; the exopod is provided with a long flagel- lum. This species appears to reach a much greater size than that described by Alcock, but the characteristic differences between the two forms are quite distinct even in the very smallest individuals. In a large male the carapace is 38 mm. broad, 27 mm. long and 16 mm. deep. It will be noticed that in the possession of a rudimentary epibranchial tooth and prominent post-orbital ridges P. supercili- osum departs somewhat from the definition of the sub-genus Geotel- phusa as laid down by Alcock. The affinities of the species with P. adiatretum are, however, clear. The twelve specimens obtained were found in hill streams between altitudes of 600 and 2000 ft. Jan. I3th-i7th, 1912. Six males, some with sj^mbiotic Tem- nocephalidae, in the Yembung river (Regd. no. ^^^). Jan. 19th, 1912. One male in the Egar stream between Reng- ing and Rotung (^'). Feb. 9th, 1912. Three males and one female, some with symbiotic Temnocephalidae, in the Yembung river (—"). March 26th, 1912. Four males, two very large, in a stream near Balek {^ , types). Sub-genus Acanthotelphusa, Ortmann. Potamon (Acanthotelphusa) feac, (de Man). 1898. Paratelphusa feae, de Man, Ann. Mus. Civ, Genova (2), XIX, p 393, Pl- iv,fig. 3- T910. Potamon {Acanthotelphusa) feae, Alcock, Cat. Indian Decapod Crust., pt. I, fasc. ii, p. 66, pi. xi, fig 51. The Abor specimens are all small , the carapace of the largest being only 17 mm. in breadth. The carapace is much less distinctly areolated than in the four larger specimens examined by Alcock ; the post-orbital crest does not form the definite tubercles found in those individuals, but exists as a very obscure and ill-defined eminence which 302 Records of the Indian Museum. [Vol. VIII, extends laterally almost to the longitude of the outer orbital tooth. In typical feae, also, a broad transverse ridge across the epi- branchial region in the neighbourhood of the posterior antero- lateral spine limits anterior and posterior depressions and of this, in the Abor examples, only the merest indication can be found. I have been able to examine a number of P. feae taken in December, 1910, in the Deshnoi river on the Assam-Bhutan frontier in the north-east of the Darrang district (Regd. no. ^) This series comprises both large and small specimens and the evidence they afford leads me to believe that it ma}' be necessary at some future date to recognize different races of this species. On comparing specimens of equal size, a slight but quite notice- able difference can be observed in the prominence of the transverse epibranchial ridges and in the character of the post-orbital crests. The more important features of P. feae are well shown in all the examples. This species was described b}' de Man from Bhamo and Teinzo in the Upper Irrawaddy and has been recorded by Alcock from Sadiya and the Dafla country. The specimens in the Abor collection were found at the following localities: — Nov. 26th, 1911. One very small example from the Dikrang river near Sadiya (Regd. no. -^'). Dec. I2th, 1911. Three very small examples from the Brahma- putra river at Kobo (^'). March 26th, 1912. Seven males and two females from a stream near Balek (^^). All were found on the plains between elevations of 400 and 600 ft. I am almost certain that the species does not exist in the hill streams at higher altitudes, though it was apparently in such situations that specimens were obtained in the Dafla country b}^ Col. Godwin-Austen. Sub-family GECARCINUCINAE. Genus Paratclphusa, Milne- Edwards. Sub-genus Barytelphusa, Alcock. Paratelphusa (Barytelphusa) harpax, Alcock. 1910. Paratelphusa (Barytelphusa) harpax, Alcock, Cat. Indian Decapod Crust., pt. I, fasc. ii, p. 95. A single small specimen with the carapace 14 mm. in breadth was found near Sadiya in the Dikrang river (Regd. no. —). The species appears to be widely distributed in Assam south of the Brahmaputra and is also recorded from the vicinity of Harmutti in the Dafla conntrv. I9I3'] Stanley Kemp : Crustacea Decapoda. 303 Family PALAEMONIDAE. Genus Palacmon, Fabricius. Palaemon hendersoni, de Man. (Plate xix, figs. 19-23.) 1907. Palaemon {Parapalaemon ?) hendersoni, de Man, Trans. Linn Soc, Zool. (2) IX, p. 446, pi. xxxiii, figs. 66-68. igro. Bithynis [Parapalaemon) hendersoni, Rathbun, Bull. Mus. Corap. Zool., Harvard, 1,11, p. 316, pi. v, fig. 3. The length of the carapace and rostrum is a little less than that of the abdomen, excluding the telson. The carapace, except on the walls covering the branchial chamber, is closely covered with very minute prickles which are easily removed by wear. The anterior margin is lobed at the base of the orbit and at the lower limit of this lobe there is a sharp antennal spine arising close behind the edge. The hepatic spine is small (figs. 19, 20). The rostrum commences as a blunt dorsal crest a little in front of the middle point of the carapace and extends beyond the end of the first segment of the antennular peduncle, sometimes as far as the junction of the second and third segments. Dorsally it bears from five to seven teeth, of which from one to three (usually two) are situated on the carapace behind the longitude of the posterior limit of the orbital notch. The teeth are more or less evenly spaced, but the posterior one is as a rule separated by a greater distance than the rest. Between the dorsal teeth are numerous hairs. On its ventral margin the rostrum bears one or two teeth near the apex. The eyes are deeply pigmented. In dorsal view a small ocellus is visible, imperfectly separated from the cornea. The basal segment of the antennular peduncle is considerably longer than the two following combined. The laminar plate, which forms the outer portion of the segment, terminates in a stout external tooth which reaches beyond the middle of the succeeding segment ; the lateral process consists of a sharp spine which extends as far forwards as the eyes. Anteriorly the inferior margin of the second segment is strongly produced. The two rami composing the upper (and outer) flagellum are fused basally for a distance scarcely greater than the extreme length of the last peduncular segment (fig. 20). The antennal scale is about two and a half times as long as broad, and the spine which terminates the shghtly convex external margin does not nearly reach the broadly rounded apex of the lamellar portion. The outer maxillipedes extend to the end of the antennular peduncle ; the ultimate segment, including the corneous terminal spine, is only a trifle shorter than the antepenultimate. The first peraeopods reach beyond the antennal scale by a little more than the length of the propodus. The proportional 304 Records of the Indian Museum. [Vol. VIII, lengths of the merus, carpus and chela are respectively as 13, 15 and 10. The dactylus is almost exactly equal in length to the palm. The second peraeopods may attain a monstrous size in males ; the two limbs may be equal in length or markedly unequal, but as a rule show varying degrees of inequality in large individuals. In very large specimens the greater of the two legs extends beyond the apex of the scale b}' the whole of the chela and carpus. The second peraeopods of eight large specimens yield the following measurements : — Measuremen ;s, mm. r^ 0 Proportional lengths of segments of chelipede to pr larger -i-> *j Dpodus -^ (U Larger chelipede r-t rQ (100). •c ja U-l .2 jA a, th 0 ipede 0 0 .13 7i th 0 aodus th 0 tylus. i CD £2 3 3 CuO'o; W)a; ^u M JT M b 2f J;! ' o^u'a 2 a +j 0 g-s 0 jH a ts 0! "d S *iJ « S CD H a ^ kT H? )— 1 ►-J PI4 S 1 a Q ^9 60 46-5 II 77 29-5 i6*o 1017 37-3 26-1 54-2 S7 57*5 53 II 8-5 29-0 i6'0 100-9 37-9 29*3 SS-2 S6 50 59 IO-5 7-3 30*0 i6-o 105-4 35-0 24-3 53'3 ^?> 49 42-5 87 67 24-0 I2-0 92-5 36-3 27-9 50*0 49 36-5 42 7-5 57 19-5 IO-3 857 1 38-5 29-2 52-8 49 40-5 44-5 8-5 5-5 21-5 1 1-5 90-8 39-5 25-6 53-5 46 44 40 8-0 6'0 20-5 IO-3 957 1 39-0 29-3 50-2 44 37 34 7-0 5-1 17-5 8-8 84-1 40-0 29-1 50-3 The whole limb (fig. 21) is closely covered with minute prickles and these become upstanding spinules on the inferior sur- faces of the ischium and merus. The palm is devoid of setae, but both fixed and movable fingers are strongly fluted and, in the hollows between the ridges, are numerous pits from which tufts of coarse hair arise (fig. 22). In living specimens these hairs always retain a quantity of fine mud. The grooving of the fingers is much more marked than in Palaemon dayanus, Henderson, and by this feature alone P. hendersoni is readily distinguished from its allies. The palm is flattened, the depth being scarcely more than three-quarters of the breadth. In large males the fingers are toothed and may gape considerably. The fixed finger usuall}' bears two teeth in its proximal half, while the dactylus also has two, situated distally of those on the opposite edge. The distal tooth of the fixed finger is frequently broad at the apex with two or more tubercles upon it. The third peraeopods reach a trifle be3^ond the apex of the antennal scale, the fourth almost to the end of the antennular peduncle and the fifth a little beyond the eye. All three pairs are beset with small prickles, most strongly developed on the posterior surfaces of the ischium and merus, and bear also scattered hairs. On the posterior and postero-internal aspects of the propodus are 1 9^3-] Stanley Kemp : Crustacea Decapoda. 305 a number of small movable spines arranged in two linear series. The dactylus bears a single terminal spine and numerous short hairs and is about two-sevenths the length of the propodus. The branchial formula is the same as in other species of the genus. The telson is broad with a triangular apex. It bears two pairs of dorsal spinules and two pairs at the apex (fig. 23). Of the latter, those of the outer pair are verj- small, while those of the inner are larger and extend a little beyond the apex. Between these spinules the margin is furnished with long plumose setae. There can,T think, be very little doubt that the specimens described above are correctly referred to de Man's P. hendersoni from Darjiling ; but it is strange that in the original description no mention is made of the characteristic grooving of the fingers of the large chelipede. In the Indian Museum are numerous examples of this species from the valley below Kurseong, a locality at no great distance from Darjiling, collected b}^ Dr. Annandale and Mr. F. H. Gravely, and in these specimens the grooves on the fingers are clearly shown. The Abor specimens agree with de Man's description and differ from the Kurseong examples and from most of those recorded by Miss Rathbun in having the fingers of the second peraeopod as long as, or a trifle longer than the palm. The species has hitherto been recorded only from Darjiling {dc Man) and from the Gokteik gorge on the border of the southern Shan States in Burma (Rathbun). Palaemon hendersoni was found plentifully in the Abor country in the Sirpo stream near Renging (Regd. nos, — j^J.^'j ^^^w^), and in the Egar stream between Renging and Rotung {-^i 'W')- Family ATYIDAF. Genus Caridina, H. Milne-Edwards. Caridina weberi, de Man, var. (Plate xix, figs. 24, 25 ; plate xx, figs. 26-28.) A Caridina which occurs in abundance in the Darrang district in tributaries of the Brahmaputra and has been found in the main river itself at Dibrugarh and Kobo appears to represent a race of C. weberi, de Man. This species was originally described from Flores and Celebes (de :\Ian, 1892) ' and a variety called suinatrensis is recorded from Sumatra (de ^lan, i892),'^ from Engano I., near Sumatra (Nobili, 1900)'' and from Cochin China, Siam and the environs of Bombay (Bouvier, 1905).* 1 In Max Weber's Zool. Ergebn. Reise niederl. Ost.-Ind., II, p. 371, pi. xxii, fig- -3- "^ Ibid , p. 37 i, pi. xxii, fig. 23g. 3 Ann. Mus. Civ. Genova (2), XX, p. 476. * Bull, Sci. France et Belg., XXXIX, p. 83. 3o6 Records of the Indian Museum. [Vol. VIII , I have compared specimens from the Brahmaputra system with examples from Bombay determined by Prof. Bouvier as var. sumatrensis and with others which appear to represent the same form from Medha, Yenna Valley, Satara district, collected by Mr. F. H. Gravely, and find a few differences which may ultimately prove of importance. The rostral teeth are less numerous. Those on the dorsal margin vary in number from lo to 17 (12 — 14 in 74% of the specimens examined) and of these 3 to 5 (usually 4) are situated on the carapace behind the orbital notch. On the ventral margin there are from i to 5 teeth {2 or 3 in 78% of" the specimens examined). The fact that a number of dorsal teeth are situated on the carapace behind the orbit (figs. 24, 25) shows that the Brahma- putra race is more closely allied to the var. sumatrensis than to the typical form. In the variety, however, the dorsal teeth are decidedly more numerous (16 — 20), and comparison with specimens from the Satara district seems to indicate that the Assamese individuals are more stoutly built with rather shorter and less slender limbs. In the chelae of the second peraeopods (fig. 27) the palmar portion is decidedly more than half the length of the dactylus, a feature noticed by Bouvier in examples of var. sumatrensis. C. weberi appears to be one of the commonest species of Caridina in India and Burma : a large collection of specimens from widely different localities awaits examination in the Museum. It will probably be possible to distinguish a number of local races, but to attempt to do so at the moment would be premature and beyond the scope of the present paper. The colour of living specimens is verj- variable. They may be uniformly dark, blotched or mottled. Frequentl}^ a broad whitish mid-dorsal stripe is found running the whole length of the animal and occasionally specimens are obtained which are verticall}^ barred on the sides. Specimens of the Brahmaputra race of C. weberi were found on the Abor expedition at Kobo (Regd. no. yjj") and at Dibru- garh (^f ). The form is also represented in the Museum collections by numerous examples from the Darrang district on the right bank of the Brahmaputra, — from the Dhansiri R. at Kowpati {—), from the Deshnoi and Rowta rivers on the frontiers of Assam and Bhutan (^f '), from Mazbat (^|") and Mangaldai {^"g). Caridina excavata, sp. nov. (Plate XX, figs. 32-35 ; plate xxi, figs. 36, 37.) The rostrum extends be3'ond the end of the antennular peduncle and in some examples reaches just to the apex of the antennal scale. In lateral view it is dor sally a little convex in the I9I3'] Stani^ey Kemp : Crustacea Decapoda. 307 neighbourhood of the orbit and a trifle concave towards the apex. In the proximal half of the upper margin it bears a series of 9 to 16 teeth (10 to 13 in 71% of the specimens examined). They are evenly spaced and movable and from o to 3 (usually i or 2) are situated on the carapace behind the orbital notch. The distal half of the rostrum is wholly unarmed dorsally, the small tooth found close behind the apex in C. nilotica and numerous other species being absent. On the ventral margin there are 2 to 8 fixed teeth (4 to 6 in 87% of the specimens examined). These teeth are placed in the distal half and the posterior one is, as a rule, situated immediately below the foremost of the dorsal series (fig. 36). The antero-lateral margin of the carapace is obtusely lobed below the orbital notch and immediately beneath this lobe there is a strong antennal spine. The orbital notch is excavated to a very unusual extent (fig. 37) ; the antero-lateral angles of the carapace are rounded. The eyes are well pigmented. The segments of the antennu- lar peduncle decrease progressively in length. The lateral process reaches beyond the eyes but does not extend to the end of the basal segment. The second segment is about one and two third times as long as wide. The antennal scale is about three times as long as broad and its straight outer margin terminates in a stout spine which is far exceeded by the rather narrowly rounded apex of the lamella. The third maxillipedes reach to the end of the second segment of the antennular peduncle. i\ll the peraeopods are unusuall}^ slender. In those of the first pair, which reach about to the extremity of the eyes, the carpus (fig. 32) is three times as long as wide and is only very slightly excavated anteriorly. The chela is longer than the carpus, the dactylus is one and a half times as long as the palm and the length of the propodus is about three and a half times its greatest breadth. The peraeopods of the second pair (fig. 33) reach a little beyond the end of the antennular peduncle. The carpus is slender, about five and a half times as long as wide and is equal in length to the chela. The dactylus is longer than the palm and the breadth of the palm is less than a quarter the length of the entire chela. The third peraeopods reach almost to the apex of the anten- nal scale and the fourth to the end of the antennular peduncle. The merus in each pair bears a single tooth in the middle of its posterior margin and one at the distal end ; a similar tooth is found at the end of the carpus. The dactylus bears from eight to ten small teeth on its margin exclusive of the spinous apex. In the fifth pair (fig. 34) the propodus is longer than in the fourth and the whole limb is consequently of greater length ; the merus and carpus are usually provided with teeth as in the preced- ing pairs. The slender dactylus is about one third the length of 3o8 Records of the Indian Museum. [Vor,. VIII, the propodus and is armed with from 40 to 50 close-set serrated spines (figs. 34, 35). The branchial formula is as follows : — Maxillipedes. Peraeopods. I 2 3 I 2 3 4 S Pleurobraucluae I I I I I Arthrobrauchiae . . . 2 I •• Podobranchiae ep. rud. I ep. 1 ep. 1 ep. f ep. •• The epipod on the third peraeopods is sometimes present, sometimes absent : more usually it is suppressed. The telson bears two pairs of dorso-lateral spinules ; there is a small spinule on either side of the apex and the margin between them is rounded and bears eight spines, the outermost slightly the largest. Large specimens reach a length of about 25 mm. In an ovigerous female (only one example obtained) the eggs average I'O mm. X '68 mm. in longer and shorter diameter. A characteristic feature in the colouration of living specimens is the presence of a broad vertical band of pigment on the side- walls of the carapace immediately over the pleurobranch at the base of the third peraeopods. In many species of Caridina the branchial formula is unknown ; but in all cases in which it has hitherto been examined epipods have been found at the bases of the first four pairs of peraeopods. The absence of these appendages from the fourth pair and their occasional absence from the third seems therefore to consti- tute a very important feature of C. excavata. Apart from this character its nearest ally appears to be C. aculirostris, Schenkel,^ from Celebes. A single example of C. excavata was found at Sadiya in the Dikrang river, while numerous other specimens were obtained in January, 191 r, in the Tezpur district on the Assam-Bhutan frontier. These were taken, for the most part, in a small back- water of the Rowta R. in the Brahmaputra drainage system (Regd. no. ^), and in this particular spot the species was found to the exclusion of C. weberi var. and C. hodgarti which were abundant in other parts of the district. A few specimens were found in the Rowta R. itself i^—-) and in irrigation channels at Mazbat in the same vicinity (-j^), but the species was for the most part decidedly rare. 1 Verhandl. naturf. Ges. Basel, XIII, 1902, p. 496, pi. viii, fig. 1913.] vStanley Kemp : Crustacea Decapoda. 309 The specimen from Sadiya has unfortunately been mislaid. Those from the backwater of the Rowta R. may be recognized as types of the species. Caridina hodgarti, sp, nov. (Plate XX, figs. 29-31 ; plate xxi, figs. ^^, 39.) The rostrum is slender and in well-grown specimens reaches well beyond the apex of the antennal scale. Its dorsal margin is slightly concave in lateral view and at the apex it is straight or trends a little upwards. In the proximal half of the upper margin there is a series of 8 to 16 rather close-set equidistant movable teeth. The number most commonly found is li ; 10 to 12 occur in 67% and 9 to 13 in 92% of the specimens examined. The posterior tooth is in rare cases situated on the carapace behind the orbital notch ; between each pair of teeth there is a single seta. Immediately behind the slender apex there is a single fixed tooth ; occasionally two are found in this position and in rare instances none at all. The ventral margin is furnished with from I to 7 stout fixed teeth, widely separated. The number most commonly found (48% of the specimens examined) is 4 . and 3 to 5 occur in 91% of the examples (fig. 38). The carapace is compressed, of greater proportional length than in most species of the genus, and the onh^ spine present is the antennal. The eyes are well pigmented. The lateral process of the basal segment of the antennular peduncle is sharply pointed and extends beyond the eyes. The second segment is twice as long as wide and is nearly twice the length of the third. The antennal scale is narrow, about four and a half times as long as wide ; its inner margin in the distal half is straight or even ver^^ slightly concave and the straight outer margin terminates in a sharp spine far behind the narrow apex of the lamella (fig. 39). The third maxillipedes and all the peraeopods are very short. The former scarcely reach the distal end of the second segment of the antennular peduncle. The first peraeopods only reach a trifle beyond the base of the antennal scale. The carpus (fig. 29) is one and a half times as long as broad ; it is scarcely at all excavate anteriorly and is three quarters the length of the chela. The palm is as long as broad and is shorter than the dactylus. The peraeopods of the second pair (fig. 30) reach a little beyond the eyes. The carpus is about three times as long as broad and is about equal in length to the chela. The palm is scarcely longer than broad and is a little shorter than the dactylus. The last three pairs of peraeopods bear spines on the meral and ischial segments much as in the preceding species. The third reach nearly to the end of the second segment and the fourth to the end of the first segment of the antennular peduncle, while the fifth reach as far forwards as the eyes. The dactyli of the third 310 Records of the Indian Museum. [Voiv. VIII, 1913-] and fourth pairs bear six or seven spines, that of the tilth (fig. 31) is comparatively broad, a little more than one third the length of the propodus, and bears about twenty-five spines The branchial formula resembles that of C. excavata, but epipods are invariably absent from both third and fourth peraeo- pods. The telson bears from four to six pairs of dorsal spinules and the round margin between the small spinule on either side of the apex bears two pairs of spines. Large specimens reach a length of 33 mm. The eggs, in the single ovigerous female examined, average "8 mm. by "4 mm. in longer and shorter diameter. Caridina hodgarti appears to find its nearest ally in vStimpson's C. grandirostris ^ from the Liu Chiu Is., but is easily distin- guished by the characters of the rostrum. The gill-formula of Stimpson's species is unknown. The pigmentation of living specimens is characteristic. The lower edge of the rostrum is deeply pigmented and there is a broad dark stripe, sometimes produced outwardly in the middle, along the inner margin of each antennal scale The inferior por- tions of all the abdominal pleura are dark and the telson is pig- mented in its distal three quarters. The inner uropod is pigment- ed throughout, except for a small pale area in the centre ; the outer uropods are transparent. The actual tint, as in all species of Caridina, is very variable; in C. hodgarti the dark patches are frequently claret-coloured. Caridina hodgarti is a common species in the Upper Brahma- putra valley. Specimens have been found at Kobo in the Abor country (Regd. no. ^^-, types), at Dibrugarh (^) and in the Darrang district on the right bank of the Brahmaputra in irriga- tion channels at Mazbat ("^^), in the Dhansiri R. at Kowpati fjf*), at Mangaldai (^jf') and in the Deshnoi R. on the frontiers of Bhutan (^)- The species has also been obtained in the Maha- nanda R. at Siliguri (^) and in the Tista R. at Jalpaiguri (^f^), both localities being near the base of the Sikhim Himalayas. The distribution, as far as it is known, ma^' therefore be said to extend along the base of the foot-hills from the Darjiling district to the Abor country. 1 Proc. Acad. Sci. Philadelphia, i860, p. 28. EXPLANATION OF PLATE XVII. Potamon {Poiamiscus) decourcyi, sp. nov. Fig. I. — Photograph of a large male, the type specimen, nat. size. ,, 2. — Third maxillipede of the same specimen. ,, 3. — Abdomen of the same specimen. Rec. Ind. Mus.,Vol. VIU, 1913. (AborExp.) Plate XVll. > o c d. w y u cr o u HI Q '(f) D O CO < h o a z o < h o a w EXPLANATION OF PLATE XVIII. Potamon (Potamiscus) aborense, sp. nov. Fig. 4. — Right half of the carapace in dorsal view, X 2\. J, 5. — Abdomen of the same specimen. Potamon {Potamiscus) sikkimense, Rathbun. ,, 6. — Abdomen of the variety described by Alcock from Nepal. ,, 7. — Abdomen of a typical specimen. ,, 8. — Left half of the carapace of a typical specimen in dorsal view, X 3. Potamon {Potamiscus) ohliteratum, sp. nov. 9. — Right half of the carapace in dorsal view, X 2. 9a.— Third maxillipede. Potamon {Geoteiphusa) adiatretum, Alcock. 10. — Left half of the carapace in front view, X 4. II. — Chela and carpus in lateral view. 12. — Carpus viewed dorso-laterally. Potamon {Geoteiphusa) adiatretum var. lophocarpus, nov. 13. — Chela and carpus in lateral view. 14. — Carpus viewed dorso-laterally. Potamon {Geoteiphusa) super ciliosum, sp. nov. 15. — Right half of the carapace in front view, X 2. 16. — Carapace in dorsal view, nat. size. 17. — Chela and carpus of the same specimen, a male, nat. size. 18. — Carpus viewed dorso-laterally, nat. size. Rec. Ind, Miis.,Vol. Vlll. 1913, (AborExp.) Plate XVIU. 8. 16. S. C. Mondial, ACChawShary, del. Semrose.CoIlo-, Derby. ABOR POTAMONiDAE. EXPLANATION OF PLATE XIX. Palaemon hendersoni, de Man. Fig. 19. — Anterior part of carapace, etc., in lateral view, X 2^. ,, 20. — Anterior part of carapace, etc., of another specimen, dorsal view, X 2. ,, 21. — Second peraeopod of adult male, X 1^. ,, 22. — Denuded fingers of the same limb, further enlarged. ,, 23. — Apex of telson. Caridina weberi, de Man, var. ,, 24. — Lateral view of a specimen of the race inhabiting the Brahmaputra river system. ,, 25. — Anterior part of carapace, etc., of the same specimen. Rec. Ind. Mus.,Vol. Vlll, 1913, (AborExp.) Plate ZIX. #ii CO Cv3 If:* DC liJ DO UJ < Z Q < u C 03 T5 Z o a: UJ Q z UJ z z o LU < < CL 00 O EXPLANATION OF PLATE XX. Caridina weheri, de Man, var. Fig. 26. — Part of first peraeopod of a specimen of the race in- habiting the Brahmaputra river system. ,, 27. — Part of second peraeopod of the same specimen. ,, 28. — Part of fifth peraeopod of the same specimen. Caridina hodgarti, sp. no v. ,, 29. — Part of first peraeopod. ,, 30. — Part of second peraeopod. ,, 31. — Part of fifth peraeopod. Caridina excavata^ sp. no v. ,, 32. — Part of first peraeopod. ,, 33. — Part of second peraeopod, ,, 34. — Part of fifth peraeopod. ,, 35. — Apex of dactylus of fifth peraeopod, further enlarged. Rec. Ind. M-us.,Vol. V1U,1913. (Abor Exp.) Plate XX. ACQicwdhsiT, del. APPENDAGES OF CARIDINA. Bcmrost. Co)i«^ Derby- EXPLANATION OF PLATE XXL Caridina excavata, sp. nov. Fig. 36. — Lateral view of one of the type specimens, j^ 37. — Anterior part of carapace etc. in dorsal view. Caridina hodgarti, sp. nov. ,, 38.— Lateral view of one of the type specimens. .J 39- — Anterior part of carapace etc. in dorsal view. Rec. Ind. Mus.,Vol. Vlll, 1913, (AborExp.) Plate XXL < o Q O I < z Q < opy RECORDS of the INDIAN MUSEUM Vol. X, Part II, No. 4. Notes on Crustdcca Decapoda in the Indian. Museum, V. Hippolytidae, By 5. KEMP. CALCUTT7\ T^PRIL, 1914. IV. NOTES ON CRUSTACEA DECAPODA IN THE INDIAN MUSEUM. V. — HiPPOLYTIDAE. By Stanley Kemp, B.A., Assistant Superintendent, Indian Museum. (Plates I- VII.) With the exception of a few more or less isolated records little has hitherto been wiitten on the Hippolytidae occurring in Indian waters. The family is well represented in the Indian Museum, but there can be no doubt that many new and unrecorded forms remain to be discovered. On a recent visit to the coasts of S. India in the vicinity of Rameswaram Island, made in company with Dr. J. R. Henderson of the Madras Museum, several species hitherto unknown from Indian coasts were obtained and there is little doubt that collec- tions from other localities would prove equally interesting. Hip- polytidae seem, for the most part, to prefer shallow water and a weedy bottom ; it was at any rate in such situations that all the species found in S. India were obtained. Our collection was made in February and at this season the majority of the females were found bearing eggs. The family Hippolytidae is one of somewhat unusual interest on account of the great diversit}^ of form found in the different genera and of the different modes in which the secondary sexual characters ma}^ find expression. Several genera such as Leontocaris , Cryptocheles, Tozeuma and Gelastocaris exhibit structural modifications of the most bizarre character ; this specialization is presumably correlated with some unusual form of livelihood, but the reasons for the peculiar adap- tations have not as yet been definitely ascertained. In many of the genera no conspicuous secondarj' sexual characters are developed, but in others they form a most notice- able feature. In some, such as Latreutes and to a less marked extent in Saron, the sexes may be distinguished b}^ the develop- ment of the upper antennular flagellum, that of the male being longer and stouter than that of the female. Young males of Saron in other respects bear a close resemblance to females, but in large individuals of the former sex the third maxillipedes and first peraeopods may attain a monstrous development, being often proportionately twice as long as those of the female. This condi- 82 Records of the Indian Museum. [Vol. X, tioii. which is also found in the genus Alope, has been discussed at length by Coutiere ; he considers it to be a case of ' dimorphism ' , but his application of the term to the phenomena found in these genera is open to question. In Thoy, on the other hand, it is the third peraeopods which are affected. In males of this genus the third leg is proportionately much longer than in the female and bears a different type of spinulation. If my results be accepted, the sexual modifications in one species of Latreutes {L. mucronatus) are of a very far-reaching nature, the whole form of the animal being different, while dis- tinctions of the most striking character are found in the form of the rostrum. The normal variation found in the species of certain genera is astonishingl}^ great, especially' as regards the form and armature of the rostrum, and it is unfortunate that almost implicit reliance was placed on this character by many of the older authors. As a consequence, a very large number of species stand in need of re- definition and considerable difficulties have been met with in identification, more particularly in the genera Latreutes and Hippolysmata. In examining the Indian forms I have described three new species and one variety, while two fresh genera are proposed, both based on forms already' described. Out of a total of twenty-two genera, the number now known from the Indo-pacific region' is fifteen, of which twelve have been found on the coasts of British India. A sound basis for the classification of the genera was outlined by Caiman in 1906^ on characters derived from the branchial formula and the development of the mandible. The Indo-pacific genera may be distinguished by the use of the following key, which is adapted and expanded from that given by Caiman. The genera Ogyris, Stimpson, and Pterocaris, Heller, are regarded as members of the Alpheidae and are not included therein. I have not seen examples of the genera Nauticaris, Ligur and Mimocaris. Key to the Indo-Pacific genera of Hippolytidae. A. Arthrobranchiae present at base of first four pairs of peraeo- pods [mandible with three -segmented palp; many seg- ments in carpus of second peraeopods j. I A movable tooth at base of uropods. A. Mandible with incisor-process ... . . Snroii. B. Mandible without incisor-process ... . Xuiiticuris. II. No movable tooth at base of uropods. A. Mandible with incisor-process ; last three peraeopods not abnormally slender ... ... ... Meriiippolyte. 1 Under this term 1 include the area extending from the Red Sea and Delagoa Bay to New Zealand, Oceania, the Hawaiian Is. and japan. ■i Caiman, Ann. Mag. Nat. llisl. (j), XVII, p. 2<). I9I4-] S. Kemp : Notes on Crustacea Decapod a. 8^ B. Mandible without incisor-process ; last three peraeo- pods abnormally slender ... ... ... Lig//r {= Pur- Iiippolyte }. B. No arthrobranchiae at base of peraeopods. I, Mandible with palp [carpus of second peraeopods com- posed of six to eight segments!. A. Mandibular palp three-segmenled ; supra-orbital spines of carapace very large [incisor-process of mandible present or absent] - ... ... ... Alope. B. Mandibular palp two-segmented ; supra-orbital spines of carapace, if present, not vcr\- large [mandible with incisor-process] ... ... ... ... Spt roiifucdns. II, Mandible without palp. A. Mandible with incisor-process. 1. Carpus of second peraeopods composed of six or seven segments ; ultimate segment of antennular peduncle with movable distal plate ... ,;: ... '1 hoy. ' II. Carpus of second peraeopods composedo! only three segments ; ultimate segment of antennular peduncle without movable plate (normal) ... HippoJytc. . B. Mandible without incisor-process. 1. Carpus of second peraeopods composed of three segments. a. No post-ocular spine on carapace ; carpus and chela of first peraeopods short and stout, dactvli of last three pairs normal. 1. Form of body stout; lateral process of basal antennular segment anteriorly rounded ; third maxillipede with exopod ; epipods at ^q base of first three or four peraeopods ... Lafrciites. p . /^ 2. Form of body very slender ; lateral process of basal anteiinular segment anteriorly point- ed ; third maxillipede without exopod ; no epipods at base of peraeopods ... ... Tozemiia. h. .\ post-ocular spine on carapace; carpus and chela of first peraeopods slender ; dact\-lus of last three pairs composed of a short basal portion bearing a cluster of large teeth [third maxillipede without exopod; epipods at base of first four peraeopods] ... ... Gelasfocaris. II. Carpus of second peraeopods composed of many segments. a. .\bdomen bearing argespines dorsally and veiU- rally ; carapace with 'longitudinal lateral cari- nae [exopod of third maxillipede present ?] ... Mimocaris. b. Abdomen without large spines ; carapace without lateral carinae. 1. Third maxillipede with exopod; epipods at base of first four peraeopods, ultimate seg- ment of antennal peduncle not abnormal m size. a. Cpper antennular fiagcllum unequjily i)H-.i- ^o mous,.. ... •■• ... Lysnitita. %-^y B. Upper antennular ilagellum uniramou.s ... JlippolysinaUi.t 2. Third maxillipede without exopod ; no epipods at base of first four peraeopods , ultimate segment of antennal peduncle abnormal in size ■•• •■■ -^^ci'^ii'^' As the literature dealing with the family is much scattered, I have given, at the end of this paper, a list of the Indo-pacific species with references. 84 Records of the Indian Museum. [Vol. X, Genus Saron, Thallwitz. Saron marmoratus (Olivier). i86y. Hippolytc kraiissi, Bianconi, Spec. Zool. Mossambic, X\'ll. in Mem. Acad. Sci. Bologna (2), IX, p. 209, pi. i, fig-. 2a. 1878. Hippolyte kraussi, Hilgendorf, Monatsb. Akad. \Viss. Berlin, p. 836. i8gS. Saron mavmoraius, Borradaile, Proc. Zool. Soc. I.ondon, p. 1009. 1902. Saron marmoratus, Borradaile, in W'illey's Zool. Results, p. 413. 1903. Saron gibberosiis, de Man, Abhandl. Senck. nat. Gas., XX\', p. 852, pi. xxvi, fig. 57. 1905. Naiiticaris grandirosfris, Pearson, Cevlon Pearl Oyster Rep., I\', p. 79, pi. i. fig. 6. 1906. Spirontocaris mavmorata, Rathbun, Bull. U.S. Fish. Conim. for 1903, p. 913. 1906. Saron gtbberostis, Nobili, Ann. Sci. nat. Zool. (9), IV, p. 40. 1906. Saron gibberosiis, Nobili, Bull. sci. F"rance et Belg., XL, p. 35. igio. Saron gibberosiis, Coutiere, Bull. Soc. philomath. Paris (lo"), II, p. 71, text-figs. Most of the earlier synonymy of this species is given in full by Borradaile {loc. cit., 1898). It should however be noticed that de Man {loc. cit., 1902) has referred Ortmann's Japanese speci- mens ' and some of those recorded by himself both in 1888 '^ and 1897 ^ to a new and very closely allied species, Saron neglectus, which is recorded in the present paper from the Andaman Is Among the male specimens of S. marmoratus preserved in the Indian Museum the variation in the proportional lengths of the third maxillipedes and first pair of peraeopods is enormous ; in twenty individuals of this sex from a single locality the third maxillipedes vary from 35 to yy% and the first peraeopods from 30 to 88% of the total length. It is this great variation that has led to the confusion that exists in the taxonomy and has induced earlier authors to describe the species under two separate names, marmoratus and gibberosiis Thanks to the work of Borradaile and de Man this confusion no longer exists, but there is still, I believe, a certain amount of misconception regarding the occur- rence of dimorphism in the genus. Borradaile, while including gibberosiis as a synonym of mar- moratus, notes that in his specimens " the males can be sharply divided into two groups having the marmoratus and gibberosus- characteristics respectively " and suggests the possibihty that the males of the species are dimorphic. This view is upheld by Coutiere in a most interesting paper entitled " I^es crevettes a males dimorphes du genre Saron" {loc. cit., 1910); but an exam- ination of the material at my disposal leads me to believe that this supposed dimorphism has no foundation in fact. The variation shown in the relative lengths of the third maxillipedes and first peraeopods is, as shown in the table on page 85, of enormous extent. In some males these two appendages } Zool. Jahrb., Syst., V, p. 497 (1890). ■^ Arch. f. Naturgesch., p. 533. 8 Zool. Jahrb., Syst, IX. p. 761. I9I4-] vS. Kemp : Notes on Crustacea Decapoda. 85 attain a monstrous size, while in others they are small and approximate more or less closely to those of the female. But this alone is, in my opinion, insufficient to prove the existence of dimorphism : it is essential that the specimens should fall into two well-delined groups and that their measurements, when plotted, should yield a bimodal curve. Measurements of our specimens show no indication of this. The greatest proportional size of the limbs is found in large specimens, but the figures, when plotted, give little other information of interest ; there is no trace of a bimodal curve and even on casual examination of the speci- mens, it is evident that for all practical purposes the series is a graded one. Measurements of mai.e Saron marmoratus. Percentage of Length of TOTAL LENGTH. Local itv. Total length. 1 1 3rd 1st 3.-d ist 1 mxpde. prpd. mxpde. prpd. i mm. mm. mm. 1 Karachi J.2 i6-5 14 39-3 33 '3 +.r5 i9'5 17-5 44- S 40-2 44 19 17 43*2 38-6 44 19 16-4 43" 2 37"3 i 46 - -' ? 21-5 48-9 467 48 25 25 52-1 52-1 49"5 -'3-5 22-3 47-5 45 49'5 23'5 22'5 47-5 45*4 ,Si 24-2 22 47-4 43" 1 53 -'5"5 24 48-1 \5?> 5.> 28 267 52-3 5«'4 5.^ 29 3«5-5 54-7 57'5 53'5 26-5 26-5 495 49'5 55 3*' 29^ 54-5 52-7 56 32 — 57-1 — 58 33 34'5 55"2 59"5 58 44-5 51 ' 767 87-9 61 37 42 i 6o-6 fi8-8 (.rS — 45-5 — 72-3 Andamans ... 3.^ 117 10 35-4 30-3 43 10 15'2 44*2 35 '3 Port Canning 41 15 12-8 i -,6-6 31-2 43-5 16 14 36-8 32*2 4«J 19 16-5 41 "3 35*9 49 1 21 i(yj 42-8 34' I 52 - 217 1 — ' 417 61-5 277 -'5-5 45 41 "5 In the measurements taken my specimens seem to agree with those examined by Coutiere who has nowhere stated that they can be sharply divided into two groups. They are, however, directly 86 Records of the Indian Museum. [Vol. X, at variance with the results obtained b}' Borradaile and for this I am unable to offer any adequate explanation. Judging from the Indian examples the variation in the males of Saron marmoratus is closely similar to that found in certain freshwater prawns of the family Palaemonidae. In a number of species of this family the second peraeopods of some males are found to hav^e attanied a huge size, while in other individuals of the same sex and species they resemble those of the female : if sufficiently large numbers are examined it is found that the speci- mens fall into a more or less well-graded series and that it is impossible to separate them into two or more groups, Coutiere considers that dimorphism also occurs in the Palaemonidae ; but his detailed study of its occurrence in Palaeinon [Eupalaejnon) lar ,^ although of great interest, does not convince me that this is the case.^ Smith defines high and low dimorphism in the following terms'*: — "It consists essentially in the existence among the males of any species of a graduated series, as regards size and the development of the secondary sexual characters, such that the smaller males have relatively poorly developed secondary sexual characters while the larger males attain to a much greater relative development of those characters. The smaller males are then termed ' low,' and the larger males "high": when there is a more or less abrupt transition in point of numbers from high to low males we may most properly speak of a high and low dimorphism existing in the males of that species, but we also apply the term more loosely to those cases in which no such abrupt transition is proved to occur." If the last sentence in this paragraph be accepted, the pheno- mena found in these Caridea may correctly be described as dimor- phism, but to do so would, in my opinion, only tend to obscure the real nature of the case. In Saron, Palaemon, and certain other genera it appears that the male may become sexually mature at a period when, in its secondary sexual characters, it shows but little external difference from the female; but that it gradually assumes the more striking features of its sex in the course of subsequent moults, just as the male parr in which the milt may be ripe gradually assumes the appearance of the adult milt salmon. In Caridea, therefore, the case is one of gradual transi- tion rather than of true dimorphism, by which is implied either a J CouliLM-e, Ann. Sci. nat. Zool. (8), XII, p. 292 (1901). Henderson and Matlhai in their account of the freshwater Palaemonidae of Southern India (Rcc. Ind. Mus., V, igio, p. 280) have advanced certain facts which seem to indicate that Palacmou scahriciilus. P. dolicho^hicfylus and P. (ill bins, belong in reality to a single species. This suggestion i"s a most interesting one and, if it be proved, trimorphism in the males of Palaemonidae will be established. The case, howcvei-, is on an entirely different fooling from that cited above, for the three forms, all founded on m'alcs of large size, differ from one another in well-marked characters drawn from the proporUonal length-, of the individual segments of the second peraeopods. 3 Smith, Miith. zool. Stat. Neapel, WII, p. -,12 (kjcOi. 1914-] S. Kemp : Notes on Crustacea Decapoda. 8y discontinuity in the development of the individual or a marked dichotomy of evolution within the limits of a species. Coutiere at the close of his paper on the males of the genus Saron gives an account of certain investigations which he has made on the condition of the testes in 5. marmoratus and neglectiis. In those specimens in which the third maxillipedes and first per- aeopods were very large he found that the testes were reduced. The suggestion that he makes to account for the condition of the individuals that he examined is a most interesting one, namely that the production of very large limbs is the result of senility. This suggestion should form the basis of further investigation, but the fact that Coutiere does not state whether all or any of his specimens, which came from widely separated localities, were killed during the breeding season, makes it impossible to accept his views without further evidence and this,- unfortunately, my own material does not provide. The specimens of Saron marinoratiis in the Indian Museum were obtained at the following localities: — ^V'^'- Queensland, Australia. OueenslanJ Museum. One, 44 nun. 10 0 103 . , , ( A. R. Anderson, t o- Anaaman Is. ^ j_ W'ood-Mason. > ^'^' ■^•^"^-' '^''"• Port Canning, Ganges J. Wood-Mason. Si.x, 4-i-<'i'5 mm- delta. ^^'J^ Kilakarai, Ramnad S. Keinjj. One, 41 mm. Dist , S India. From coral ree^. ,s_4.^5j-5 Pamban, Ramnad S. Kemj:). rweniy-tour, 1(^-43 . Dist., S. India. mm. Prom coral reeh 3i»fi- C Karachi, M. of R. Karachi Musjum. lu.rty-eight, 36-65 3il|rl7 3 Indus mm. Kubbar 1. ree;, Per- 'investigator.' 'i'wo, 34 and 59 mm. sian Gulf, ijjio Mauritius. (Purchased. 1 One. 50 mm. The Pamban specimens were collected in February, 19 13. All the larger individuals are ovigerous females and many of them bear coarse tufts of hairs on the rostrum, carapace and abdomen much as in Hippolyte varians form, jascigera. Saron marmoratus has been recorded from Australia (Milne- Edwards) from the Hawaiian Is. (Randall), and from many locali- ties in Oceania and in the Malay Archipelago (Dana, Heller, de Man, Borradaile etc.). It is also known from Ceylon (Pearson), Mozambique (Biaiiconi, Hilgendorf), Zanzibar (Ortmann), the Arabian coast (Nobilij, and from the Red .Sea (Heller, Nobili). Saron neglectus, de Man. 1888. Hippolyie gihberosa. dj Man, .Vrel;. f. Nalurgesch. I.III, 1. p. 533 [part 17)1). i8qo. Hippolyte gibberosa, Orlmann, Zt)ol. Jahrb., Sy.st., \ . p. 497 {nee. syii. I. 88 Records of the Indian Museum. [Vol. X, 1897. Hippolyte gibberosa, de .Man. Zool. Jahrb., S\si.. IX, ]). jOl {partim). igo2. Saro>i neglectiis, di: Msin, \h\\imd\. Senck. nalurf. (ies., XX\', p. 854, pi. xxvi, fig. 58. 1910. Sa:-on iieglectus, Coutiere, Bull. Soc. philonialh.. Paris (loi, II, p. 71, figs. pp. 73, 78. I have nothing to add to the excellent descriptions and figures given by de Man and Coutiere. There can be no doubt that the species is valid. --^- S. Senlinel I., Andamans. ' Investigator.' Two, 24 and 25 mm. ^ifj- Andamans. ' Investigator.' Two, 15 and 23 mm. The largest specimen is an ovigerous female. Saron neglectus is known from Kagoshima, Japan (Ortmann), New Caledonia (Coutiere), Ternate (de Man), Batavia (de Man), Djibouti, Red Sea (Coutiere) and Madagascar (Coutiere). Genus Nauticaris, Bate. 1906. Naiiticai'is, Caiman, Ann. Mag. Nat. Hist. 171. X\TI. p. 31. I have seen no Indian examples of this genus. Pearson ' has recorded three species from Ceylon. The first of these, N. grandi- rostris, is, as Dr. Pearson has kindly informed me, synonymous with Saron marmoratus, the second N. unirecedens, Bate, is a species of Hippolysmata, while the third N . futilirostris. Bate, was originally described from Japan. This last form may be a true N auticaris , but inasmuch as the branchial formula and mandibular palp have not been examined, it is impossible to come to an}' satisfactory conclusion regarding its generic status. Genus Merhippolyte, Bate. 1906. Merhippolyte, Caiman, Ann. Mag. Nat. Hist. 17 I, X\'II, p. 32. The identity of the forms recorded under the names Hippolyte spinifrons and Merhippolyte spinifrons is discussed on p. 90; that they have been incorrectly referred to the genus Merhippolyte can scarcely be doubted. Merhippolyte calmani, Kemp and Sewell. 1912. Merhippo/vfe cat /mini, Kemp and Scwcll, Rvc. ind. M\is., \T1, p. 20, pi. i, figs. 1-4.2 When describing this species Capt. Sewell and I remarked on its close external resemblance to Spirontocaris kanaiensis, Rath- bun,'^ from the Hawaiian Is. ; I have now, thanks to the kindness of Miss Rathbun, been able to examine a specimen and some dissected portions of individuals belonging to that species. 1 Ceylon Pearl Oyster Rep., IV, p. 81 i 1905). 2 It should be noted that in fig. 3 the incisor-process of the mandible is fore- shortened, the process is in reality etjual in length to the mandibular palp. i^ Bull. I'. S. I'"ish Comm. for 190;,, XXIII, p. S27 1 1906"). I9I4'] S- Kemp: Notes on Crustacea Decapoda. 89 Spirontocaris kauaiensis possesses arthrobranchs at the base of the peraeopods and a three-segmented mandibular palp, while there are 13 or 14 segments in the carpus of the second peraeo- pods. The species must, in consequence, be transferred to the genus Merhippolyte and is a very close ally of M. calmani. The two forms are, I believe, specifically distinct. M. calmani seems, on the whole, a slightly more slender form than M. kauaiensis with legs proportionatel}^ a trifle shorter. The branchio- stegal angle of the carapace is more abruptly rectangular and the eyes decidedly larger than in the specimen from the Hawaiian Is. ; the breadth of the cornea is about one-quarter the median length of the carapace in the former, whereas in the latter it is about one-fifth. In the eye of M . kauaiensis , moreover, there is a small ocellus, touching the cornea but quite distinct from it, and of this in the Indian species there is no trace. In M. kauaiensis the second peraeopods fail to reach the apex of the antennal scale by the whole length of the chela, whereas in M. calmani they extend by almost the same amount beyond the apex. The exopod on the third maxillipede is rather shorter in M. kauaiensis than in its ally and there are no epipods on the last three pairs of legs; in M. calmani only the epipod of the fifth leg is absent. Genus Alope, White. The generally accepted definition of this genus must be modi- fied in one important respect in order to include Alope ansiyalis. Baker, a species in which the incisor-process of the mandible is obsolete. In A. palpalis, White, the type and only other known representative of the genus, this process is considerably reduced, so that it is not altogether surprising to find that it is absent in the allied species. Alope still remains well defined, for among the Hippolytidae only two other genera, NatUicaris, Bate, and Ligur, »Sarato {= Pay hip poly tc, Borradaile) possess a mandible which is devoid of an incisor-process and at the same time furnished with a three- segmented palp and from both of these it is at once distinguished by the absence of arthrobranchs at the base of the peraeopods. Alope palpalis. White. (Plate I, figs. T, 2.) '.' i,S37. HippoJvtc spinifrons. H. Milne- Kdwards, Hist. nat. Crust., 11, p. 377. 1847. Alope palpalis, While, Ann. Mag. Nat. Hist. (21, I, p. 22b. 1S74. Alope palpalis, Miers, Zool. Voy. ' Krebus ' and ' Terror,' Crust., p. 4, pi. iv, fig. I. i87(). Alope palpalis, Miers., Cat. Crust. N. Zealand, p. 80, V 1876. liippolvte spiuifvotis, Miers., ibid., p. 80. 1886. Hippoiyte spiiiifroiis, Filhol, Mission de lile Campbell, HI, p. 431, pi, liii, fig. 13. 1886. Alope palpalis, Filhol, ibid., p. 433. 1899. Alope palpalis, Coutiere, Ann. Sci. nat. Zool. 181. I.\, p. 79, text-fig. p. 36. 90 Records of the Indian Museum. [Vol. X, 190,^. Alope palpalis, Thomson, Trans. Linn. Soc, Zool. 121, VTII, p. 440, pi. xxviii, figs. 3-12. 1903. Mei'liippolyfe spinifrons, Thomson, ibid., p. 444. 1909. Alope palpalis, McCulloch, Rcc. Australian Mus., \ II, p. 313, text-figs. 2, 3. 1906. Mei'liippolyfe spiiiifroiis = :' Alope polpnlis, Caiman, Ann. Mag. Nat. Hist. ( 7 I, X\T1, p. 32. Dr. Caiman has suggested that Hippolyte- spinifrons, Milne- Edwards, is probably a species of Alope and with this view I am in entire agreement. It seems likely that the phrase '' les epines suborbitaires " in Milne-Edwards' description is a clerical error for 'Mes epines supra- orb itaires " ; this hypothesis explains the italicization of the whole passage and appears to me more pro- bable than the view advanced by Bate ' that the words refer to the lateral process of the antennular peduncle. In other respects the description agrees well enough with Alope palpalis; but until the matter has been placed beyond all doubt it is, in my opinion, not advisable to change the name of this well-known form. Several subsequent authors have recorded both Alope palpalis and Hippolyte spinifrons from the New Zealand coast ; but it does not appear that any of them, with the possible exception of Filhol, examined both forms. Filhol's Hippolyte spinifrons, as is shown by the figure, is undoubtedly synonymous with White's Alope palpalis \ he refers to the supra-orbital spines as "epines sus-orbitaires ' ' following Milne-Edwards' mistake in terminology. He gives no description of \i\'& Alope palpalis and it is possible that he has supplied records of its occurrence without examining speci- mens ; his work, as a whole, is not such a? to inspire confidence. Thomson, under the name Merhippolyte spinifrons, merely quotes Filhol's account, and the examples subsequently recorded by Chilton * under this name from the Kermadec Is. are, as I have been able to determine by examination of specimens kindly sent me by the author, to be referred to the genus Lysmata (see p. no). It is, I believe, most improbable that Milne-Edwards' description was based on this species. Alope palpalis is represented in the Indian Museum by a single ovigerous female which differs rather markedly from Thomson's description and figures (/or. cit.). In the second pair of peraeopods the ischium and merus on the right side are composed of two segments and the carpus of seven (fig. 2). On the left side the ischium is two-, the merus three- and the carpus eight-segmented (fig. i). The processes on the thoracic sternum bear little resemblance to Thomson's figure and are closely similar in form to those of the allied species, A. australis (see pi. I, fig. 5). Thomson does not refer in any definite way to the great development of the third maxillipedes and first peraeopods in 1 Bate, Rep. 'Challenger' Macrura, pp. 621, 622 (1888). ■^ (hillon. Trans. N. /.c.il.-ind Insl., Xi.lii, p. 547 (i()ii). 1914-] S- Kemp : Notes on Crustacea Decapoda. 91 large males of this species, but from Mier's figure (1874, ^oc. cit.) it is evident that this is sometimes a conspicuous feature. ^~\T}^ New Zealand. C'anterburv Mas. exch. One, ,^9 mm. Alope palpalis appears to be restricted to the coasts of New Zealand and the neighbouring islands, the records of its occurrence in Australian waters refer to the following species. Alope australis, Baker. - (Plate 1, figs. 3-5.) 1882. A/opt- palpalis, Haswell, Cat. Australian C rust., p. iq,v 1898. Alope palpalis. Stead, Zoologist (4), II, p. 211. 101)4. Alope aiistralis. Baker, Trans. Ro}-. Soc. S. Australia, XXVIII, p. 154, pi. xx\, figs. 1-7. 1909. Alope aiistralis, McCulloch, Rcc. Australian Mus., \'tl, p. ;;i,^, text -fig. I. The chief distinctions between this species and A. palpalis, White, are as follows ; — A. aiistralis. A. palpalis. Rostrum not reaching as far Rostrum reaching as far for- forwards as basal segment of wards as basal segment of an- antennular peduncle. tennular peduncle. Supra- orbital spines reaching to tips of eyes. Supra-orbital spines scarcely reaching beyond base of eye- stalks. I/ateral process of basal seg- ; Lateral process of basal seg- ment of antennular peduncle ex- ment of antennular peduncle tending little, if at all. beyond extending far in advance of end of segment. basal segment. Mandible without incisor-pro- '■ Mandible with incisor-pro- cess. ; cess. The five Burmese specimens examined differ from Baker's description and figures in a few particulars. The antennular peduncle reaches beyond the middle of the antennal scale, the second segment is longer than the third and is longer than broad ; the lateral process of the basal segment extends at most to the distal end of the segment, usually falling far short of it (tig. 3). Baker states that A. australis differs from A. palpalis " in the less divided state of the second pereiopods— except the carpus" and in his figure the merus and ischium of this limb are not segmented. In four of the Indian examples the ischium and merus of this pair are each divided into two segments, while the carpus is composed of seven. In the fifth specimen, a large male, the left leg is similarly segmented, but the right, which is abnormally short, shows traces of subdivision into two and three segments in the ischium and merus and the carpus consists of ten segments, two of these, however, being only feebly indicated (fig. 4). 92 Records of the Indian Museum. [VOL. X, Three of the specimens examined possess five dorsal teeth on the rostrum ; in the other two there are only four. The mandible agrees closely- with Baker's figures; but the second segment of the palp is as broad as long. A small ridge at the base of the palp is all that remains of the incisor-process. The processes on the thoracic sternum of the large male (fig. 5) consist of (i) a sharp upstanding keel between the third and fourth pairs of peraeopods, (ii) a pair of acute backwardly directed teeth between the fourth and fifth pairs, and (iii) a con- spicuous plate, very deepl}^ bifurcated anteriorly, behind the base of the last pair. In small males and in an ovigerous female the processes are similar, but the anterior bifurcation in the plate behind the fifth peraeopods is much less pronounced. The endopod of the first pair of peraeopods is, in the male, unequally bifid at the apex ; in the female it is simple and ends acutely. In the large male example the third maxillipedes are as long as the entire length of the animal (measured from the tip of the rostrum to the apex of the telson), though in other males and in the female they are less than half the same proportional length. The five specimens yield the following measurements: — Sex. Total length. Length of 3rd mxpde. Ratio of 3rd mxpde. to total length. mm. m m . c? 22 t^-5 39 c? 25 II 44 c? 30 14 47 oi-_v Tlior fioi'iduinis. \'eri-ill, rivms. Conn. Acad., XI, p. 19. I9()^. Ilippolvie hasclialis, I.enz, .\bh. Senck. natun". (ies. I"r-ankfuri, XXVli, p. 382. 1905. Pascltocaris paschalis, Nobili, Bull. Mun. d'Hist. n.at.. Paris. P- 394-_ 190(1. Pasc/iocaris pasc/ia/is, Nobili, Ann. Sci. nat. Zool., Paris in), 1\", p. 38, pi. iii, fig. I. The SNaionjany shown above is given with confidence. Not onl}' is it at once evident from comparison betv^een Nobili's description of Paschocaris (1906) and that of Thor, as given by Miss Rathbun, that the two genera are identical, but I have been able to compare American examples, received under the name of Thor floridanus from the United States National Museum, with specimens from vS. India which unquestionably belong to the form described by Nobili as Paschocaris paschalis. The identit}^ of the two forms is complete, unless it be that any importance can be attributed to the slightly stouter and more gibbous form of the S. Indian specimens : microscopic examina- tion of the appendages fails to yield evidence for the recognition even of a subspecies in the case of the American form. The fact is one of considerable interest, for, among littoral Decapoda, it is most unusual to find a species inhabiting l)oth the Atlantic and the Pacific without exhibiting any distinct structural differences.' It is scarcely necessary to describe the species in detail for good accounts have already been given by Heller, de Man, Rathbun and Nobili. In the examples from S. India the rostrum is bifid at the apex (in one specimen trifid) and bears three or four (very rarely two) teeth oh its dorsal margin ; one of the dorsal teeth is usually situated on the carapace behind the orbital notch. In the American examples the apex is bifid in four specimens, trifid in a fifth, and there are four dorsal teeth. i Faxon (Mem. Mus. Comp. Zool. Harvard, 1895, XVII, p. 235, toolnotc 1 gives a list of Decapoda which ha\'e been recorded both from the Gulf of Panama and from the West Indian side of .'\merica : the identity of the species of .Mplwiis mentioned in this list is, as he remarks, doubtful. Excluding free-swimming forms such as Pasipliae sivado and those having a circumpol.ar distribution, the only littoral Decapoda Natantia that I can call to mind which inhabit both the .\tlantic and the Indo-pacific are Peiietis cnraniote, Sieiiopits Iiispidiis. Proccssn cannliciilata and Athaiias niiesceiis, and some of lhes(> cases re<]uire further investigation. I9I4'] S. Kemp : Notes on Crustacea Dccapoda. 95 The carpus of the second peraeopod is composed of six, less commonly of seven, segments. It is described by Miss Rathbun as " five annulate ", and six segments are distinct in the American examples which I have examined. The two proximal articula- tions are much less clearly marked than the remaining three, and the fact that in one specimen (fig. 9) there is a further subdivi- sion, making three short proximal segments, indicates that the character is subject to some variation. In the normal 6-seg- mented carpus the proportional lengths of the segments differ somewhat from Miss Rathbun's description, but agree closely with the account given by Nobili. Comparison of fig. 7, which repre- sents the carpus and chela of a specimen from Florida, with fig. 8, in which the same segments of a S. Indian individual are shown, will indicate the almost exact similarity in segmenta- tion. A feature of the species which seems to have escaped notice hitherto is the great development of the third peraeopod in the male. In the female (fig. 6) this limb is closely similar to those of the two succeeding pairs, but in males, both from Florida and from S. India, it is very much longer (fig. 10), reaching beyond the apex of the antennal scale by the dactylus and about one-half of the propodus. The propodus, moreover, is broadened towards its ultimate end and the inferior margin is, for rather more than its distal third, thickly beset with slender spines. The dactylar spines of the limb are also far more numerous. As regards the spinulation of the merus in the last three pairs of legs there is considerable variation. In one example (from America) it bears five spines, in others two, three, or none at all. The telson bears three pairs of dorsal spinules : in some specimens four on one side and three on the other. The spinulation of the apex of the telson agrees with Nobili 's description. The following specimens have been examined : — ~"Y(f " Kilakarai, Ramnad Dist., S. Kemp. Seventeen, 7-12 nun. S. India, ^^i Pamban, Ramnad Dist., S. Kemp. One, 12 mm. S. India. -^"^^ Punta Rassa, Morid.i. .Smiths. Insl. I'ive, 10-14 mm. The specimens from Kilakarai and Pamban were found among weeds in water only a few feet deep. They were caught in February, 1913, and all, with the exception of two, are ovigerous females. Thor paschalis has been recorded from Amboina (de Man), the Red Sea (Heller, Nobili) and from Zanzibar (I^enz). In the Atlantic it is known from the West Indies, the Bermudas, Florida, Yucatan and neighbouring localities (Kingsley, Rathbun, Verrill). Genus Hippolyte, Leach. i860. I'irlii/is, .Stimp.son, Proc. .Acad. .Nat. Sci. [Philadelphia, p. ;;5. 96 Records of the Indian Mitseu)ii. [Vol. X, Hippolyte ventricosus^ H. Milne-Edwards. Plate II, figs. 1-3. 1S37. Hippolyte ve/ify/cosiis, H. Milne- Kdwards, Hist. nat. Crust., 11, P-.37I- 1878. Vii'biiis mossamhicus, Hilgendorf, .Monalsb. Akad. \\ iss. Berlin, p. 836, pi. iv, fig. I. This species is very closely related to Hippolyte varians, L/each, and should perhaps be regarded merely as a subspecies. The two forms may be distinguished by the following charac- ters : — H . ventricosus. H. varians. Rostrum rather more slender ; armed with one or two dorsal teeth in its proximal third ; apex acuminate (fig. i). Antennal scale not more than three times as long as broad (fig- 2). Thoracic appendages propor- tionately stouter ; middle carpal segment of second peraeopods as broad as long (fig. 3). Sixth abdominal somite about one and a half times as deep as long. Size smaller, ovigerous fe- males not exceeding 20 mm. in lensth. Rostrum less slender, armed (usually) with only a single dorsal tooth in its basal third ; a small dorsal tooth nearly al- ways present close to apex, giving it a bidentate appear- ance. Antennal scale three and a quarter to three and a half tinies as long as broad (fig. 4). Thoracic appendages propor- tionately more slender ; middle carpal segment of second perae- opods nearly twice longer than broad (fig. 5). Sixth abdominal somite twice as deep as long. Size larger, ovigerous females sometimes 31 mm. in length. Apart from the characters afforded by the rostrum, which, owing to the enormous range of variation that exists in both species, must necessarily be somewhat inconclusive, the principal difference between the two forms rests in the stouter build of that found in the Indo-pacific region. Structural distinctions of this nature are found in almost every part of the body, but in most cases they are so slight that it is scarcely possible to demonstrate them mathematically. They are, however, clearly shown in the proportions of the last abdominal somite and carpal segments of the second peraeopods and find less well-marked expression in the form of the antennal scale. The three segments composing the carpus of the second peraeopods have the same longitudinal pro- portions as in H. varians. The mouth parts of the two species are in closest agreement (the mandibles are nearly identical in struc- ture) and no noteworthy differences are to be found in the I9I4-J S. Kemp : Notes on Crustacea Decapoda. 97 arrangement of the gills and epipods or in the spinulation of the telson-tip and of the dactyli of the last three pairs of peraeo- pods. Milne-Edwards' description of Hippolyte ventricosus is ex- tremely brief and runs as follows : — " Espece extremement voisine de I'H. variable, mais dont le rostre ne porte en dessus qu'une seule dent situee pres de sa base, et dont les prolongemens lateraux des trois premiers anneaux de I'abdomen presentent des dimensions tres-considerables. I^onguer environ 4 lignes.' ' " Trouvee par M. Dussumier dans les mers d'Asie. (C. M.) " The species does not seem to have been recorded — as H. ventricosus — ^since Milne-Edwards' time; but I believe that Virhkts mossambiciis , a name given by Hilgendorf in 1879 to a species found off the mouth of the Zambesi, is synonymous. Milne-Edwards' reference to the abdominal segments is per- plexing, for no definite differences are to be found in this respect between the Indian specimens and English examples of Hippolyte varians. The description of the rostrum seems, however, to leave little doubt of the identity of the species, more especially as, with the exception of V. mossambicus, no form closely resembling H. varians has yet been found in Asiatic waters. The species appears to be very nearly related to H. orientalis, Heller', and it is possible that this name must be included in the synonymy of H. ventricosus. South Indian specimens agree well with Heller's description except that it is extremely rare to find among them an example with four teeth on the inferior margin of the rostrum. Nobili ■•'■ considers Paulson's H. proteus ^ a synonym of Heller's H. orientalis; but according to Czerniavsky * Paulson has confounded under the former name several known species, viz. H. bridlei , Guerin, (■^=//. prideauxiana , Bell), H. gracilis, Heller, and H. leptocerus, Heller. Czerniavsky may be right, in part; but on general grounds it appears to me very unlikely that H. prideauxiana and H. gracilis occur in the Red Sea. It is probable that H. ventricosus does so, but it is impossible to speak with any certainty untii further information is available. Indian specimens of H. ventricosus differ from H. proteus, as figured by Paulson in the shorter antennular peduncle and in the carpal segmentation of the second peraeopods. The specimens of //. ventricosus in the Indian Museum are registered thus : — - ' Heller, Sitzber. math.-naUinv. Klasse d. Kais. .\cad. Wiss. Wien, XLHl, p. _>77 (1861). * Nobili, .\nn. Sci. nat. Zool. (()), IV, p. 33 (19061. s Paul.son, Red Sea Crustacea, Kiew, p. log, pi. \vi, figs. 2-s ; pi. .xviii. %•• I (1875); ■*• Czerniavsky, Crustacea Decapoda Pontica [Jlloralia, p. 13 ( 18S4). 98 Records of the Indian Museum. [Vol. X, '^-Tn"— Kilakaiai and Apal., Ramnad "^ Dist., S. India, 0-2 fnis. (c- i- \i S4(ii o 1 ij J T->- .^ c- r ->■ Kemp. iVlanv, 7-20 mm. ^^^- Pamban, Kamnad Dist., S. I ' -' ' India, 0-2 fms. ) The species was found in abundance at both the above localities, living among Zostera and other weeds inside the coral reef at depths ranging from low water to two fathoms. The speci- mens were obtained in an environment closely similar to that in which H. varians abounds on the English and Irish coasts and, at the time of capture, it was thought they must certainly belong to that species. In colour the majority were of a brilliant green ; but very many other types, each having its counterpart in home waters, were observed. The collection, which was made in February, 1913. contains a high proportion of ovigerous females. Hippolyte australicnsis (Stimpson). Plate II, fig. 6. i860. ]^irl>iiis ausfrnlie)isis Stimpson, Proc. Acad. Sci. Philadelphia, P; 35- 1882. Virbtus austrolieiisis, Haswell, Cat. Australian Crust., p. 186. Specimens of this species received in exchange from the Australian Museum differ from those of the preceding form in possessing no teeth on the dorsal margin of the rostrum and in having from four to six teeth (rarely three) ventrally. The ultimate segments of the antennular peduncle are shorter and broader, the second being broader than long, the antennal scale (in an ovigerous female) is three and a third times as long as broad and the last segment of the third maxillipede is scarcely twice the length of the penultimate. The proportions of the segments in the carpus of the second peraeopods are also different (fig. 6). The mJddle segment, as in H. varians and H. ventricosus, is much the shortest, but the third is decidedly longer than the first. The last three pairs of legs are stout. In an ovigerous female the propodus 01 the fifth pair is only five and a half times as long as broad and is little more than twice the length of the dactylus (spines included). * 7'i?_tr9 New South Wales Australian Mus. TweU'c, 13-22 Coast. exch. mm. Hippolyte australieiisis is known only from the Australian coast. Genus Latreutes, Stimpson. 1906. fAiti'eutes, Caiman, Ann. Mag. Nat. Hist. 17), X\'II. )). 33 [iibi Carapace without supra-orbital, but with antennal spine ; a series of small spines on antero-lateral margin. Basal process of antennular peduncle anteriorly rounded : upper antennular fiagellum uniramous. Mandible without incisor-process or pal]). 1914-] S. Kemp : Notes on Crustacea Decapoda. 99 Third maxillipede with exopod. No arthrobranchs at base of peraeopods ; epipods present on at least first three pairs. Carpus of second peraeopods composed of three segments. Nearly all the species of this genus stand in need of re-defini- tion. They are for the most part based on the character of the rostrum which, iti this genus, is subject to even greater variation than in Spirontocaris or Hippolvte. The three species known from the Indian coasts may be separated thus : — I. Dactyli of last three pairs of peraeopods with con- spicuous spines on margin. A. Form very slender, basal segment of antennular peduncle three times as long as wide, antennal scale more than six times as long as wide; legs short, second pair not reaching to end of eyes ... .. L. pvgniaeiis, B. Form stouter, basal segment of antennular peduncle twice as long as wide, antennal scale not more than four and a half times as long as wide (less in adults) ; legs longer, second pair reaching beyond end of antennular peduncle . Z. niiicronafus. II. Dactyli of last three pairs of peraeopods simple claws, without spines on margin ... ... L. anoplouyx. I have seen no specimens of the very curious Laireutes ceylon- ensis described by Pearson from the Ceylon pearl banks. ^ The species differs from all other members of the genus with which I am acquainted in the peculiar spinulation of the carapace and antennal scale and in the armature of the dactyli of the last three peraeopods. In many respects it appears to be allied to Nobili's Laireutes paronae which is here regarded as the type of a new genus, Gelastocaris. Latreutes pygmaeus, Nobili. Plate II, figs. 7, 8 ; Plate III, figs. 1-7. 1904. Latreutes pyg)naeits, Nobili, Bull. Mus. d'hist. Nat., Paris, p. 230. 1906. Latreutes pygmaeiis, Nobili, Bull. sci. France Belg., XL, p. 37, pi. iii, figs, 4, a-h. igoO. Latreutes pygruaeus, Nobili, Ann. Sci. nat. Zool. (9), IV, p. 41. Ivarge series of specimens obtained at Kilakarai and Paml^an in S. India ma}' undoubtedly be referred to[[this species, which is a very close ally of the Atlantic L. ensifer, Nobili's account ma}' be supplemented as follows : — The small dorsal spine on the carapace behind the orbit is movable, as in L. ensifer, and not fixed as in certain other species of the genus. The rostrum is sometimes wholly unarmed, but more usually bears from i to 3 dorsal teeth and i to 3 ventral teeth, all situated in the distal third. The apex may be acute or bluntly rounded (pi. II, figs. 7, 8 ; pi. Ill, figs. 1-3). Close to the cornea on the inner and superior aspect of the stalk the eye bears a small conical process similar to that described by Nobili in allied species. 1 Ceylon Pearl Oyster Rep., IV, p. 81, pi. ii, figs. 7, 7 a — e. 100 Records of the Indian Museum. [Vol.. X, The antennular peduncle reaches to less than half the length of the antennal scale. Its basal segment is elongate (pi. Ill, fig. 4), about three times as long as broad, and its lateral process is anteriorly rounded and feebly bilobed. The second segment is, in the female, longer than broad. The antennal scale (pi. Ill, fig. 5) is very sharply pointed anteriorly and is more than six times as long as broad. The third maxillipedes reach to the base of the antennal scale, the peraeopods of the second pair to the middle of the eye, those of the fifth pair extending scarcely further forwards. Of the three segments composing the carpus of the second peraeopods the middle one is the longest and the third the shortest. The middle segment is about one and a half times the length of the first and the first is one and a third, or rather more than one and a third times the length of the third : there is a little variation in the precise measurement of these segments. The dactyli of the last three peraeopods terminate in sharp curved spines : there are a few other spines on the po.sterior margin, the ultimate being large and placed close to the terminal spine, giving the apex a biunguiculate appearance (pi. Ill, fig. 6). Epipods are present at the base of the first four pairs of legs. The sixth abdominal somite is fully one and three quarters the length of the fifth. The telson in S. Indian specimens bears only two pairs of dorso-lateral spinules in addition to those at the apex, not three as Nobili has stated. The male is very different in appearance to the female. It is much more slender in build and the rostrum seldom bears more than one tooth on either margin near the apex. The antennular peduncle is shorter than in the other sex, but the upper flagellum is stouter and very much longer. In the female the flagellum does not nearly reach the apex of the antennal scale, whereas in the male it extends beyond that point by almost half its length. The colour of living specimens is ver}^ variable. As a rule the}^ are of a uniform dull green, but olive, brown and brownish red specimens are frequent. Latreutes pygmaeus has exceedingly close affinities with L. ensifer^ Milne Edwards, the type species of the genus. I have compared South Indian specimens of the former species with examples of the latter obtained in the Sargasso Sea. The Atlantic form is slightly more robust in build, the rostrum is more strongly concave above and the teeth are more closely restricted to the apex. The legs are a little longer, the second pair reach- ing the ends of the eyes, the antennal scale is proportionately a trifle broader and the sixth abdominal somite is shorter and a little less slender. The second segment of the antennular peduncle is about as broad as long in the female Probably the best distinc- tion between the two forms rests in the number of epipods at the base of the legs; in L. pygmaeus they are found on the first four pairs, while in L. ensifer thev occur onlv on the first three. 1914.] S. Kemp : Notes on Crustacea Decapoda. loi ;^« Kilakarai Ramnad l),st., S. India. | g_ ^^ ^^ „^,^^_ H Pamban, Ramnad Dist., S. India. ) ' •' ^ Latreutes pygmaeus was common at both of the above locahties living among weeds in a few feet of water ; in Hfe the species bore a close general resemblance to the British Hippolyte pyideauxiana. The collection, made in the month of February, includes a large proportion of ovigerous females. The species has been recorded by Nobili from the S. E. coast of Arabia and the Red Sea. Latreutes mucronatus (Stimpson ). Plate III, figs. 8-15 ; plate IV, figs i, 2. 18O1). Rhyiiclwcvcliis iiiiuToiuifiis, Stimpson, Proc. Acad. Sci. Phila- delphia, p. 28. 1902. Latreutes viitcrouatiis, Doflein, Abhandl. bayerisch. Akad. Wiss.. XXI, p. 638, pi. V, fig. 6. 1904. Latreutes gravieri, Nobili, Bull. Mus. Hist, nat., p. 231. 1906. Latreutes gravieri, Nobili, Bull. sci. France et Belg., XL, p. ,^9, pi. iii, figs. 4-44. 1906. Latreutes gravieri, Nobili, Ann. Sci. nat. Zool. (9), IV, p. 41. igo6. Latreutes mucronatus var. niultidens. Nobili, ibuL p. 41, pi. ii, %■ ,v Examination of a series of specimens from S. India suggests that L. gravieri must be regarded as a synonym of L. mucronatus and that there is no foundation for the retention of the varietal name niultidens- The series comprises twenty-nine examples, and of these eighteen were immediately separated from the rest on account of their stout and gibbous form and more or less circular rostrum (pi. Ill, figs. 8,9; pi. IV, fig. I). They were at once referred to L. mucronattis and examination of their rostral formulae indicated that the type specimen of L. mucronatus with a formula of f and those referred by Nobili to his var. multidens, with formulae ranging from "g \^i\ are only terms in a series exhibiting con- tinuous variation. The formulae which the S. Indian specimens yield are as follows ' : — 1)15 1)13 i)iz i)ii 1)10 i)ii_i i)g i)7_ 1)12 i]9 15 13 13 12 II 9 ^ ^7 7 1)8 1J8 1)8 1)7 3)jo 3)Q i_)8_ 4j_i3 7 7 7 7 ^^ <^ 6 4 The remaining specimens characterized by their more slender form and narrower rostrum (pi. Ill, figs. 10, 11 ; pi. IV, fig. 2) afforded a more difficult problem. Not only did the rostrum exhibit a most remarkable diversity of form, but the proportions ' The figure on the left, separated by a bracket, represents the number of teeth on the carapace in the media-n line. 102 Records of the Indian Museum. [Vol. X of the antennal scale and the spinulation of the antero-lateral margin of the carapace also showed extensive variation. A single specimen, however, the onl}^ one which possessed two teeth on the carapace (pi. Ill, fig. n) was referred without difficulty to to L. gravieri, and by an attentive study of the remainder the conclusion that they also must belong to that species was reached. It was only when these preliminary results were obtained that it was noticed that all the examples referred to L. mucro- natus were female, while all referred to L. gravieri were male. The fact that both forms were found together at each of the two localities where specimens were obtained, suggested that the con- clusions derived from the form of the animal and the characters of the rostrum were fallacious and a renewed study of the proportional measurements of the appendages and comparison with the sexual distinctions found in L. pygniaeus led to the conclusions outlined in the above synonymy. In the female specimens (pi. IV, fig. i) the rostrum reaches almost to or a little beyond the end of the antennal scale. At its base it is inferiorly excavate for the accommodation of the eye and in lateral view the length from the back of the orbit to the apex is less than twice, often not more than one and a half times the greatest height. Anteriorly the rostrum is sometimes almost circular in outline, but more often it is distinctly pointed. The dorsal and ventral teeth are borne only in its distal half. The carapace is strongly arched dorsally. It is not carinate in the median line but bears, as a rule, a single stout fixed tooth behind the base of the rostrum: in rare instances three or four teeth (pi. Ill, fig. 8) are found in this position. There is a sharp- antennal tooth and a series of small spines, usually ii — 14, on the antero-lateral margin. The eyestalk is a trifle wider than the cornea and bears a conspicuous pointed process on its inner distal aspect. The antennular peduncle reaches a little beyond the middle of the antennal scale and has the proportions shown in pi. Ill, fig. 12. The antennal scale (pi. Ill, fig. 13) is about three times as long as wide. The outer maxillipede reaches a little beyond the antennal peduncle. The second peraeopods reach about to the apex of the rostrum. The carpus is divided into three segments, of which the first and third are approximately equal, each being about half the length of the middle segment. The palm is a little longer than the last carpal segment and is decidedly longer than the dactylus. The dactylus of the last three pairs of peraeopods, as in L. pygmaeus, terminates in two stout claws and bears three or four small spines on the posterior margin. In the fifth pair the carpus is a little more than two-thirds the length of the propodus. The dactylus is rather more than one-third the length of the propodus. jgi^.j S. Kemp : Notes on Crustacea Decapoda. 103 The last abdominal somite is about twice the length of the fifth. The telson bears two pairs of dorsal spinules and terminates in a narrow pointed process flanked by a pair of spines on either side. The innermost of these is more than twice the length of the outer and is often nearly twice as long as the median process. The outer uropod is shorter than the inner and is about three and a half times as long as broad. In the male the whole form of the animal is far more slender, as will be seen on comparing figs. 1 and 2, plate IV. The rostrum is longer and much narrower in lateral view; it extends well beyond the apex of the antennal scale and exhibits the follow- ing spine formulae — 1)7 1)7 1)7 1)8 1)5 £)5 1)4 i]4 1)5 J06 _2)5_ X ~^ 4 I o It seems that, as in L. pygniaeus, the teeth are on the whole less well-developed in males than in females ; some of the males ^ however, are of very small size and may not have developed the full complement. Seen laterally the greatest length of the rostrum from the back of the orbit to the apex varies from two and a half to four times its greatest height: proportions strikingly variable and different from those found in the female {cf. pi. Ill, figs. 10, II, pi. IV, fig. 2, and pi III, figs. 8, 9, pi. IV, fig. i). The carapace is not arched in lateral view. It bears a single dorsal fixed spine in ten of the specimens examined, while in the eleventh, which in this respect resembles the type of L. gravieri, there are two. It will be noticed that one, three, or four spines have been found in this situation in females. The differences in other respects between the two sexes are less striking. There may be only six or seven spines on the antero- lateral margin of the carapace. The upper antennular ramus is stouter and very considerably longer than in the female ; this feature affording the readiest distinction between the two sexes. The antennal scale may be four and a half times as long as broad ui young males (pi. Ill, fig. 14); in older specimens the length is usually about three and a half times the breadth. In one individual the outer margin is very definitely concave (pi. Ill, fig- 15)- The third maxillipede scarcely reaches beyond the antennular peduncle. The second peraeopods in large specimens reach beyond the middle of the antennal scale, but are shorter in small examples. They agree precisely with those of the female in the proportional length of the segments. The dactylus of the last three pairs agrees with that of the female and is a little more than one third the length of the propodus The propodus of the fifth leg is usually shorter than in the female and is not quite so long as the merus. I04 Records of the Indian Mtiseum. [Vol. X, According to Miss Rathbun' Stimpson's Rhynchocvclus mucronatus is synonymous with Latreutes planirostris (De Haan) : but no reasons are advanced for this view and Stinipson appears to have had both species before him when writing in t86o. The Indian specimens differ widely from L. planirostris as figured and described by De Haau.'^ "^o^ Kilakarai, Ramnad Dist., S. India. | ^ r- ( Twenty nine, ~fo" Pamban, Ramnad Dist., S. India. ^ " ' "^ '"*■ | 9-i3'5 mm. The specimens were obtained in February, 1913, among weeds in water only a few feet deep ; the females are ovigerous. Latreutes mucronatus has been recorded from Sagami Bay, Japan (Doflein), Hongkong (Stimpson), Java (Nobili, sub var. multideiis), the S. E. coast of Arabia and the Red Sea (Nobili, sub var. multidens and L. gravieri). Latreutes anoplonyx, sp. nov. Plate IV, figs. 3—5. This species, founded on a single adult female, is readily distinguished from the two preceding by the simple claw-like dactyli of the last three peraeopods. The specimen is robust in build. The carapace is not carinate mid-dorsally, but bears a sitigle prominent fixed tooth in the middle of its anterior third. The antennal spine is strong and there is a series of eleven small spines on either antero-lateral angle (fig. 3). The rostrum is triangular in .shape; it reaches beyond the apex of the antennal scale and is rather more than three-quarters the length of the carapace ; its greatest height in lateral view is rather more than one-third its extreme length from the back of the orbit. The dorsal margin is concave (the apex being directed obliquely upwards) and bears thirteen teeth in the distal two- thirds of its length ; the inferior margin is evenly curved and is furnished with nine teeth in its distal half. The extreme apex is broken off and on it one or two additional teeth may have been situated. On the eyestalk there is a lobe similar to that found in the preceding species, but much less conspicuous. The anteniiular peduncle is very short, reaching to little more than one-third the length of the antennal scale. The lateral process is rounded and the second segment is broader than long. The stout upper antennular ramus reaches (in the female) almost to the end of the scale. The antennal scale (fig. 4) is pointed anteriorly and is about four times as long as wide. i Proc. U.S. Nat. Mus., XXVI, p. 4(1 ( 1902). 2 In Siebold's Fauna Japonica, Crust., p. 175, and aila^, j)!. xU'. W^, 7 (1843-9,. I9I4-] S. Kemp : Notes on Crustacea Decapoda. 105 The oral appendages do not differ noticeably from those of the two preceding species. The third maxillipedes reach beyond the end of the antennular peduncle ; the ultimate segment is less than twice the length of the antepenultimate. In the chela of the first peraeopods the finger is about as long as the palm. The second peraeopod reaches to the middle of the rostrum. Of the three segments composing the carpus, the first is scarcely half the length of the second and is a little longer than the third ; the chela is as long as the middle segment and the dactylus is shorter than the palm. The third peraeopods reach forward a little beyond the end of the second and the fifth extend to the end of the eyes. The dactylus in each of the last three legs consists of a strong curved claw about one third the length of the propodus ; it may bear a few microscopic spinules, but is otherwise wholly unarmed. Large epipods are present at the base of the first four pairs of peraeopods. The sixth abdominal somite is more than one and a half times the length of the fifth. The outer uropod is two and two-thirds times as long as broad. The telson bears two pairs of dorsal spinules and terminates in a narrow apex composed of a short median process with two spines on either side ; the inner spine is longer than the median process and nearly twice the length of the outer (fig. 5). In the absence, in the majority of cases, of any information regarding the spinulation of the dactyli of the last three legs, it is difficult to make suggestions regarding the affinities of the species described above. It appears to be most nearly related to Ortmann's L. laminirostris , but differs from that, and apparently from all other known species of the genus, in the form of the rostrum. Bombay. Bombay Nat. Hist. Soc. One, ovigerous female, 39 mm. TYPE. For the opportunity of examining the single known example of this species i am indebted to the Secretary of the Bombay Natural History Society. Genus Tozeuma , vStimpson. i860. Tozemna, Stimpson, Pioc. Acad. Sci. Philadelphia, p. 26. 1863. Aiigiisiii, Bate, Proc. Zool. Soc. London, p. 408. Form extremely slender. Carapace without supra-orbital, but with antennal spine ; a single spine at antero-lateral (pterygostomian) angle. Lateral process of antennular peduncle sharply pointed anteriorly. Upper antennular flagellum uniramous. Mandible without incisor-process or palp. Third maxillipede without exopod. ^ Stimpson informs us thai this name is derived from the Greek To^ev/xa, but, if the spelling is emended, the name is preoccupied by Walker for a o-enus of Hymenoptera. iot> Records of the Indian Museum. [Vol. X, No arthrobranchs or epipods at base of peraeopods. Carpus of second peraeopods composed of three segments. Tozeuma armatum, Paulson. 1875. Tozeuma armatum, Paulson, Red Sea Crustacea, Kiew, p. cjy, pi. XV, figs. 2, a-o. 1893. Angasia sfimpsoni, Henderson, Trans. Linn. Soc, Zool., \', p. 437, pi. xl, figs. 18-20. 1906. Angasia armata, Nobili, Ann. Sci. nat. Zool., Paris (9), 1\', p. 42. The specimens agree well with the published descriptions and figures. In two perfect individuals there are respectively twenty and twenty-four teeth on the inferior margin of the rostrum. Of the segments composing the carpus of the second peraeopods the first is the longest and the second the shortest, the third being only a little longer than the second. The dactyli of the last three pairs of legs bear several spines much as in Paulson's figure, but in an ovigerous female only two are found in this position. All the examples bear a sharp inferior spine on either side of the sixth abdominal somite near its distal end. The lateral spine on the posterior edge of the fifth somite is present in all the specimens and in one individual there is a second large spine on this margin placed lower down : the difference is not correlated with sex. The only male individual is badly damaged, but in the proportions of the upper antennular liagellum does not diff'er from the female. ^~^^- Off Cinque I., Andamans, ' Investigator.' One, imperfect. 36 fms. -y^- S. E. of Ceylon ; 6° 2' 30" X., ' Investigator.' Three, the largest 81° 29' E., 52-68 fms. an ovigerous fe- male, 77 mm. Tozeuma armatum has been recorded from the Gulf of Martaban, Burma (Henderson) and from the Red Sea (Paulson and Nobili). Genus Gelastocaris, nov. Carapace without supra orbital spine and withoitt spine or spinules on antero-lateral margin. Post-orbital and antennal spines present, the latter strong and flanked by a well-marked carina. Rostrum triangular in dorsal viev/, forming eaves which conceal the eyestalks. Basal segment of antennule terminating in an upstanding process which protects the eyes anteriorly ; its lateral process large and subquadrate. Upper antennular flagellum uniramous. Outer margin of antennal scale furnished with spinules. Mandible without incisor-process or palp. Third maxillipede without exopod. Carpus and chela of first peraeopods elongate ; chela smaller than that of second peraeopods and furnished with peculiar interlocking spines at apex Carpus of second peraeopods composed of three segments. Dactylus of last I9I4-J S. Kemp : Notes on Crustacea Decapoda. 107 three pairs consisting of a very short basal portion bearing four large spines two of which are lateral in position. No arthro- branchs at base of peraeopods, epipods present on first four pairs. This genus is instituted to receive the very peculiar species described by Nobili under the name of Latrcutes paronae. In the absence of the exopod on the third maxillipede and in the presence of epipods at the base of the peraeopods the genus is intermediate fn position between Latreutes and Tozeutna^ but differs from both in the extraordinary structure of the first peraeopods and in several other characters mentioned in the above diagnosis ; it is most improbable that it has any close genetic relationship with either of these genera. The structure of the second maxillipede is peculiar ; the ultimate segment of the exopod articulates termin- ally with the penultimate^ resembling that found in the primitive families of Caridea. Gelastocaris, like several other genera of Hippoh^tidae, shows an extraordinary degree of specialization and, except for the fact that it belongs to the Latreutid section of the family, its affinities are obscure. Judging from its peculiar structure it seems probable that the genus is specially adapted to some unusual mode of life ; but inasmuch as only three specimens are known, regarding none of which are any biological data available, this must remain a matter of conjecture. Gelastocaris paronae (NobiH). Plate V, figs, i — ir. 1905. Latreutes paronae. Nobili, Boll. Mas. Torino. X.\, No. 506, p. 2, text-tig. The species is of a very robust build ; the carapace, rostrum and abdomen are beset with minute papillae, while on many of the appendages there are delicate featheiy setae. The^ carapace (fig i) is not definitely carinate above, but there is a rounded mid-dorsal prominence a little behind the middle and anteriorly, a huge blunt ridge which is highest above the orbital notch and thence rapidly declines to the smooth non-carinate surface of the rostrum. There is no supra-orbital spine, but the anterior margin is produced to a .sharp point defining the lower limit of the orbit and immediately below this point, above the insertion of the antennae, is a sharp outstand- ing post-orbital spine. The antennal spine is very .strong and is flanked by a sharp carina which extends backwards to the middle of the carapace. The antero-lateral portion beneath this carina is flexed inwards on either side, enclosing the first two pairs of maxillipedes. The antero-lateral angle is obtusely rounded ;^ it is not provided with a spine, or, as in Lati^eiitcs, with a series of spinules. In lateral view the inferior margin of the carapace is seen to be excavate posteriorly, leaving the apices of the last four pleurobranchs exposed. io8 Records of the Indian Museum. [Vol. X, The rostrum is triangular in dorsal view and its breadth at the base is fully two-thirds its length. In transverse section it would be T-shaped as in TozeiDim, for the inferior part of the blade is well developed, the dorsal part is flat or only a trifle convex, and there is a sharp ridge on either side running to the back of the orbit. This lateral ridge is produced in the vicinity of the eye and forms an eave which conceals the greater part of the eyestalk. In lateral view the dorsal line of the rostrum is straight and greatly depressed, forming an angle of nearly 45" with the mid-dorsal line of the carapace. The total length of the rostrum is about half that of the carapace; it extends a little beyond the apex of the antennal scale and terminates in a sharp upwardly directed point. On the dorsal surface, close behind the apex, there is a conspicuous movable spine. The greatest depth of the inferior blade is nearly one-half the total length. It is strongly curved in lateral view, excavated at the base for the accommodation of the eyes, and is devoid of spines. The corneal part of the eyes is well pigmented and is a little narrower than the stalk. The antennular peduncle is peculiar. The basal segment appears as if moulded round the eye ; in lateral view it is almost semicircular in shape and distally it projects upwards in front of the cornea in the form of a thin lamella. The lateral process is large, parallel-sided and apically truncate ; it projects outwards at right angles from the segment and its distal portion, which is somewhat reflected upwards, is pressed closely against the eyes. The second and third segments are extremely short. The upper ramus is thickened and (in the female) reaches a little beyond the apex of the rostrum ; the lower ramus is more slender and a trifle longer. The antennal scale (fig. 2) is about twice as long as broad and is very strongly narrowed apically. It terminates in a stout spine and on its outer margin there is a series of small movable spinules, twenty to twenty-two in number Its dorsal surface is covered with small papillae similar to those found on the carapace ; the ventral surface is beset with very long fineh^ plumose setae (fig. 3), a few occurring on the upper surface also. The mandible is furnished neither with incisor-process nor palp. The second maxillipedes (fig. 4) are peculiar in that the ultimate segment of the endopod is not applied as a strip along the whole length of the penultimate, as in the more typical Caridea, but is terminal in position resembling that found in the more primitive families, the Pasiphaeidae and Bresiliidae. The epipod is entire and not partially divided into branchial plumes as in many Hippolytidae. The third maxillipedes reach a little beyond the rostrum and possess an epipod but no exopod. The basal segments are very broad and the ultimate, which is about twice the length of the penultimate, bears a series of eight spines on its margins (fig. 5). 1914-] S.Kemp: Notes on Crustacea Decapoda. 109 The first peraeopods (fig. 6) differ from those found in most Hippolytidae in being slender ; they reach a little beyond the eyes. The ischium is short and the merus, which is rather strongly- curved, is one and a half times the length of the carpus. The carpus is four times, and the chela, which is a little longer, is four and a half times as long as broad. The length of the dactylus. excluding its spines, is contained nearly two and a half times in that of the palm. The armature of the chela is, I believe, unique. The fingers (fig. 7) bear no teeth on their inner margins, but the apex of each is truncate. At the end of the fixed finger there are three large blunt spines, curved near the tip, arranged side bv side in a transverse row ; the dactylus is similarly armed, but bears only two spines which, when the claw is closed, fit into the interstices between those of the opposing segment. All the spines are movable. At their base, on either side both of the dactylus and of the fixed finger, there is a tuft of long setae which are shortly plumose; two of these setae, situated alongside the dactylar spines but on a slightly lower level, are stouter than the rest and probabl}' assist in grasping. The second peraeopods (fig. 8) are more normal in structure. They reach to the apex of the rostrum and are stouter than those of the first pair. The merus, the middle of the three segments composing the carpus, and the chela are approximately equal in length. The first carpal segment is equal to the third and the two combined are a little longer than the median segment. The dactylus is about two- thirds the length of the palm. There are no teeth on the inner edges of the claw, but the fixed finger has an angulate prominence a little behind its middle point. The limb bears scattered plumose setae. The last three pairs of legs are similar ; the third reaches to the end of the antennal scale and the fifth to the anterior third of the carapace ; all are densely beset with long plumose setae. In the third pair (fig. 9) the merus is about four times as long as wide ; it bears a stout spine at the distal end of its inferior margin and movable spinules on its upper edge. The carpus is massive and the protuberance at the distal end, overhanging the articulation with the propodus (found in most Hippolytidae) is very strongly developed ; the total length of the carpus is nearly three-quarters that of the propodus. In the fifth leg the merus is much broader, about twice as long as wide, but the proportions of the other segments are much the same. The dactylus is very peculiar. In the third and fourth pairs it consists of a very short basal portion to which four large teeth are attached. Two of these lie in the same plane (the normal plane of the dactylus), while the others, which are a little smaller, are attached one on each side. In the fifth pair the arrangement is similar, but the lateral teeth are, in one specimen, reduced to small conical processes. The abdominal somites are obscureh- furrowed transversely and their inferior margins bear short spines. These are most no Records of the Indian Museum. [V^OL. X. strongly developed on the fourth and fifth somites, where there are in one specimen five and seven respectively. The sixth somite is only a very little longer than the fifth. The telson (fig. lo) is broad at the base and narrows rapidl}" towards the apex ; it bears two pairs of dorsal spinules. The apex (fig. ii) consists of a slender median tooth with a pair of spines on either side, the inner nearly twice the length of the outer. The outer uropod is less than twice as long as broad. The specimens examined are ovigerous females ; the eggs measure from -55 to '65 and from -45 to -55 mm. in longer and shorter diameter The specimens described above agree well with Nobili's brief account. In the type, however, the carina from the antennal spine extends backwards nearly to the posterior end of the carapace and the ultimate carpal segment of the second peraeopods is said to bear a spine at its distal end. There are two examples in the Indian Museum — ^*P 3 miles N.N.W. of Pt. Ped,-o, ) , , • , , ^ ^o -' ^ , } In\estipator . One, i -, mm. Ceylon. S ^ ^ ^j^- Ceylon Pearl banks. T. Southwell. One, 14 mm. The type was found in shallow water at Zanzibar. Genus Lysmata, Risso. Carapace without supra-orbital, but with antennal spine ; pterygostomian spine present or absent. Lateral process of anten- nular peduncle anteriorly pointed. Upper antennular flagellum biramous, the two rami fused at base. Third maxillipede with exopod. Epipods but no arthrobanchs at base of first four peraeopods. Carpus of second peraeopods composed of many segments. Lysmata chiltoni, sp, nov. Plate VI, fig. 1-4. 1911. Mei'hippolytcspiiiifi'(>)is, Chilton, Trans. N. Zealand Inst., XI. Ill, P- 549- Owing to the doubt that exists regarding the identity of Milne- Edwards' Hippolyte spi)iifrons , a species referred to the genus Merhippolyte by subsequent authors, I asked Dr. Chilton if he would permit me to examine the specimens which he recorded under this name in 191 1 from the Kermadec Is. He very kindly sent me two examples, which most unfortunately dried up in transit, and subsequently forwarded two others, all the material that remained at his disposal. The question of the identity of Milne-Edwards' H. spinijrons is discussed above and the conclusion I have reached is the same as that advanced by Caiman, namely that the species is in all pro- bability synonymous with A lope palpalis. Dr. Chilton's examples do not agree at all closely with Milne-Edwards' description. 1914. J S.Kemp: Notes on Crustacea Decahoda. in Examination shows tiiat the mandible lacks both incisor- process and palp, that there are no arthrobranchs at the base of the peraeopods and that the inner antennular fiagellum is conspicuously biramous. The species therefore belongs to the genus Lysmata and I believe has not hitherto been described. The rostrum (fig. i) commences as a median dorsal crest a little in front of the middle of the carapace ; it is straight and extends onl}^ a trifle beyond the eyes. On its upper margin it bears five teeth, two of which are situated on the carapace behind the orbital notch, while the third is placed almost immediately above that point ; the distance between the two posterior teeth is slightly greater than that between those placed further forwards. Iiiferiorly the rostrum bears two or three teeth very much smaller than those on the upper edge and placed close to the apex in advance of the anterior dorsal tooth. The only spine on the carapace is the antennal, the ptery- gostomian angle is obtuse but not spinous. The lateral process on the basal segment of the antennular peduncle (fig. 2) is sharply pointed anteriorl}^ and reaches to the end of the segment ; the second segment is about as broad as long. The inner antennular flagellum is biramous ; but the two branches are fused basally for a distance equal to half the length of the shorter ramus. The fused portion is composed of from nine to twelve segments. The antennal scale is a little less than three and a half times as long as wide and is not much narrowed distally. The outer margin is concave and terminates in a spine which scarcely extends beyond the lamellar portion. The third maxillipedes reach beyond the antennal scale by one-half the length of the ultimate segment. The exopod is conspicuous. The first peraeopods just fail to reach the apex of the scale. The carpus is a trifle shorter than the chela and the finger is about half the length of the palm. The second peraeopods, in the single perfect specimen examined, are a little unequal, the longer one extending beyond the antennal scale by the whole length of the carpus and chela. Both ischium and merus are annulate and there are 25 or 26 segments in the carpus. The last carpal seg- ment is about as long as the palm, and the dactyUis, which is decidedly longer than the fixed finger and bears two small teeth at its apex, is almost as long as the palm (fig. 4). The third peraeopods reach beyond the antennal scale by the dactyl us and three-quarters the length of the propodus ; the fifth scarcely reach the apex of the scale. There are no spines on the ischium and merus, but there are four large teeth, increasing in size distally, on the dactylus. The fifth abdominal somite, measured dorsally, is three quarters the length of the sixth and is about half as long as the telson. The telson is shorter than both inner and outer uropods. It bears two pairs of dorsal spinules and its convex lateral margins ri2 Records of the Indian Museum. [Vol. X, meet in a comparatively narrow setose apex, minutely pointed in the middle and with two pairs of spines on either side, the innermost much the longest. Lysntata chiltoni '■ differs in man}' respects from the well-known L. seticaudata, Risso, the chief points being the length and dentition of the rostrum, the form of the pterygostomian angle and antennal scale, the length of the fused portion of the rami of the upper antennular flagellum and the number of segments in the carpus of the second peraeopods. Lysmata intermedia (Kingsley) may be distinguished by the much greater length of the fused portion of the antennule and by the comparatively short dactylus of the first peraeopods. It is in Heller's Lysmata pusilla from the Red Sea that L. chiltoni seems to find its nearest ally ; but in that species the thicker ramus of the upper antennular flagellum is fused proxi- mally with its fellow for only one third its length, there are only four dorsal teeth on the rostrum and the two situated on the ventral margin are more widely spaced. In the antennal scale, moreover, the distal spine projects beyond the apex of the lamella. Four specimens were obtained at Meyer I. in the Kermadec group. The type specimen is 27 mm. in length and is preserved in the Canterbury Museum, New Zealand. Genus Hippolysmata, Stimpson. Carapace without supra-orbital, but with antennal spine : antero-lateral (pterygostomian) spine present, reduced, or absent. Lateral process of antennular peduncle anteriorly pointed. Upper antennular flagellum uniramous. Mandible without incisor- process or palp. Third maxillipede with exopod. Epipods (some- times rudimentary), but no arthrobranchs at base of first four peraeopods. Carpus of second peraeopods composed of many (more than 10) segments. The only difference between this genus and Risso's Lysmata is that in the latter the outer antennular flagellum is split and is composed of two unequal rami which are fused basally. In Hippoly- smata the flagellum is simple. The character does not seem a very important one, but in m}^ experience is reliable' ; it is, however, not improbable that further investigation will reveal such a degree of gradation that two distinct genera can no longer be recognized, and in this case all the species must take rank under Lysmata. In two West Indian species, 'Hippolysmala moorei, Rathbun^ and H. intermedia,^ Kingsley, the additional ramus is well developed and they mu.st in consequence be transferred to Risso's genus. Two new species are here described from material in the 1 I ha\e compared specimens with bot'n L. xehca/it/dfa and L. inter media. 2 In addition to the species mentioned in this paper ' have examined Lysmatu seficatidata, Kisso, Lysmata intermedia I Kingsley;, Hipj^olvsmntti californica. Stimpson, and HippolysDiata iviirdemainii (Gibbesl. ■^ Sec Rathlmn, Bull. T. S. l'"ish C'omm. for \qnn, X\, ii, pp. 115. \ih (i»)()_'). 1914] S. Kemp: Notes on Crustacea Dccapoda. 113 Indian Museum. One of these, H. eiisirostris, a peculiar form which shows but little afUnitv with any species hitherto known, is remarkable for its wide range of variation. It seems, indeed, that extensive variation exists throughout the genus in regard to the rostral armature, the proportional length of the legs and the number of segments in the carpus of the second pair ; in consequence it is not advisable to found species on these characters alone. In the case of the Indian species the armature of the dactylus of the last three peraeopods, the development of the epipods and of the antero-lateral spine of the carapace and the form of the telson have proved of considerable value in s\'stematic work. The colouration of at least some of the species is very striking and it is probable that they could be more easily recog- nized in the field than from preserved material. The Indian species of Hippolysmata may be determined bj' the following characters : — I. Rostrum shorter than carapace, without elevated basal crest ; pterygostomian spine, if present, smaller than antennal : lateral margins of telson convex, apex blunt with a pair of spines. .\. Rostrum not reaching' beyond second segment of an- tennular peduncle, inferior margin with 2-4 teeth ; dactylus of last three peraeopods terminating in two large claw-like spines. 1. A minute spine at antero-lateral angle of carapace ; fingers of first peraeopods, when closed, meeting only at tips. a. Second peraeopods symmetrical, carpus composed of 15-24 segments ... ... ... . . H.vittata. b. Second peraeopods asymmetrical, carpus composed of 28-32 segments. ... ... ... ... H. vittata, var. 2. No spine at antero-lateral angle of carapace ; fingers of first peraeopod, when closed, meeting throughout their length. ... ... ... ... H. kukenthali. B. Rostrum reaching be}'ond antennular peduncle, inferior margin armed with 6-7 spines ; dact\'lus of last three peraeopods simple. ... ... ... ... H. dentafa. II. Rostrum longer, usually very much longer than carapace, with an elevated dentate basal crest ; pterygostomian spine as large as antennal ; lateral margins of telson concave, apex acute and unarmed. A. Carapace smooth or sparsely punctate laterally, depres- sion between branchial and cardiac regions usually obscure; basal crest of rostrum with 7-12 teeth ; fifth peraeopods not extending beyond antennal scale. ... //. eusivostvis. .iuita vittatn, I,anchester, Proc. Zool.Soc, London, p. 563. 1906. Hippolysmata vittaf a, Nobili, Ann. Sci. nat. Zool. (9), IV, p. 46. 1907. Hippolysmata vittata, de Man, Trans, f.inn. Soc, Zool. (2), IX, p. 423, pi. xxxiii, hgs. 49, 50. Ii4 Records of the Indian Museum. [Vol. X, Under the last reference de Man quotes the earlier synon^-niy of this abundant species. To his detailed description I have little to add. I would, however, remark on the presence of a small (pterygostomian) spinule at the antero-lateral angles of the cara- pace (fig. 6) and to the gape at the base of the fingers of the chela of the first peraeopods when the claw is closed (fig. 7); it is only by attention to these seemingly trivial details that spirit specimens of Hippolysinafa vittata can be distinguished from the allied H . kukenthali. The rostrum in Indian examples of H. viltaia bears six to nine dorsal teeth; the hindmost is situated just in front of the middle of the carapace and is always separated by a considerable interval from the next of the series. On the inferior margin there are from two to four very small teeth The antennal scale, in adults, is a little less than three times as long as broad. The second peraeopods are symmetrical and the distal end of the merus, which may be annulated, reaches to about one- third the length of the antennal scale. The carpus is composed of I5~i9 segments. Stimpson in his original description gives 20, and subsequent authors 17 — 24. In the proportions of the last segment and of the chela the specimens agree closely with de Man's account. On the last three legs there are five or six dactylar spines which increase in size as thev approach the apex (fig- 8) The telson (fig. 9) has convex margins and a comparatively broad apex which is furnished with the two pairs of spines found in most members of the family. The colour of living specimens is very striking The whole animal is practically transparent with narrow longitudinal stripes and streaks on the carapace and abdomen. At the anterior end of the first abdominal somite there is a complete transverse band and another is distinct at the anterior end of the fourth somite. The latter stops half way down on either side where it meets the uppermost of the three complete longitudinal stripes of the abdomen. Tliere are other short longitudinal streaks on the cara- pace and abdomen, those on the anterior portion of the former being oblique. There is a median red stripe on the telson and on each inner uropod. The thoracic appendages are clear red and the eggs light green. The following specimens are preserved in the Indian IMu- seum : — Madras. J. R. Henderson. One, ,:;i mm. Kilakarai Ramnad Disi., S. W. Kemp. .Man\-, 14 — 27 mm. S. India, o — 2 tins. N. Cheval Paar, Ceylon. T. Southwell. One, ji mm. c, 1; 7 7 10 •IJJl-i 3.2i^^__Go ( Karachi. Karachi Museum. I'Orlv, 18^ — ,^0 mm. Persian Gulf, 28° 59' N., ' Investigator. ' Three, 24 — ^4 mm. 5o°3'H-, 25fm.s. 1914-] S. Kemp : Notes on Crustacea Decapoda. 115 The examples from Kilakarai were found among weeds in only a few feet of water; many of them are ovigerous females. The Persian Gulf specimens differ from others in the collec- tion in having the teeth on the inferior margin of the rostrum (4 or 5 in number) larger, though still smaller than those on the upper edge. The rostrum also is longer, reaching to the middle of the ultimate segment of the antennular peduncle (fig. 10). The form perhaps deserves nonienclatorial recognition. Hippolysmata vittata Las been recorded from the Inland Sea of Japan (de Man), Hongkong (Stimpson), Cebu (Thalhvitz), Penang (Lanchester) and the Red vSea (Nobili). H. vittata var. ? Two specimens in the collection differ from typical H. vittata in the development of the second pair of peraeopods. In the larger example the left merus of this pair of limbs reaches beyond the apex of the antennal scale by one- fifth of its length and the carpus, which is composed of 31 segments, is as long as the rostrum and carapace combined. In this specimen the right leg of the second pair is unfortunately missin.g. In the smaller example the right merus reaches to three- quarters the length of the antennal scale and the carpus, which is composed of 28 segments, is almost three-quarters the length of the carapace and rostrum. On the left side the ischium, merus and carpus are each almost exactly two-thirds the length of the same segments on the right; the carpus, however, is composed of the same number of segments The rostrum in each case bears seven teeth above and two below. The form is, in all probability, merely a variety of H. vittata in which the second peraeopods are unequal and with a greater number of segments in the carpus. In all other respects there appears to be the closest resemblance Ijetween the specimens and typical examples. The variation is similar to, though not as extensive as that found in Processa canaliculata on the Irish coast. ' The two specimens were found at the Andamans, in which locality typical H. vittata have not yet been found. ''f^^ East 1., Andamans. A.R.Anderson. Two, 14 and .'3 mm. Hippolysmata kiikcnthali (de Man). Plate VI, fig. II. 1892. Mei'Iiippolyte un'eiitatis, de Man \ ucr Bale), m Weber's Zuol. Krgebn. Raise in Niederland. Ost-Ind., 11, p. 4"7- 1902. Meyliippolyte orientalis Bate?, de Man, .\bhandl. Senck. nalurf. Ges. Frankfurt, XXV, p. 849, pi. xxvi, fig. 56. 1 Kemp, Fisheries Ireland, Sci. Invest, for i>)o8, p. 124 ( 1910). ii6 Records of the Indian Musenm. [Vol. X, IQ02. Hippolyte ki'tkentliali, de Man, ibid., \), '6^0. igtiS- Xdiiticaris iiiiirecedens, Pearson f;7er Bate ), (evlon Pe.irl Oyster Rep.. IV, p. 81. iqt)/. fl ippoh'SDKifa khkenfliiili. i.\i- Man, Trans. I .inn. Soc. Zool.iii, IX, p." 426. Along with an example of the preceding specie.s obtained by Mr. T. Southwell on the Ceylon pearl banks and forwarded to the Indian Museum pieserved in formalin are specimens of a very closely allied form which appears to be the same as that originally described b}' de Man under the name of Merhippolytc orientalis, Bate When received, the two forms were distinguished at once by their colouration, for the specimen of H . vittata was streaked longitudinally with narrow red stripes, as already described, while those of H. kUkenthali were broadly banded transversely, the colour of the bands being bright red in the preserved material. The species is so closely allied to H. vittata that had it not been for the colour distinction it is possible that the distinctions would have escaped detection ; the only important structural differences that I have been able to find are the following : — H. vittata. A minute spine at antero- lateral angles of carapace (fig. ^). Fingers of first peraeopods, when closed, meeting onl}^ at the tips (fig. 7). H. kiikenthali. No spine at antero-lateral angles of carapace Fingers of first peraeopods, when closed, meeting throughout their length (fig 11) These two characters seem to prevail with absolute constancy. The rostrum in H. kiikenthali is a trifle more bent downwards and is provided on an average with fewer teeth. On the dorsal margin there are from four to seven, usually five or six; the two hindmost, as in H vittata, are situated on the carapace and are separated by a considerable interval from the next of the series. On the inferior margin there are one or two. rarely three, small teeth. The lateral process of the antennular peduncle is a trifle longer than in the allied form and often reaches the distal end of the proximal segment. In the antennal scale, oral appendages, maxillipedes and peraeopods there appears to be the closest resemblance between the two forms, the only difference being that noticed above in the shape of the chelae of the first peraeopods, a feature not men- tioned by de Man. The carpus of the second peraeopod is divided into 19-21 segments, the proportions of the proximal segment and of the chela being as in H. vittata ; the spinulation of the dactyli of the last three pairs is the same as in that species. The epipod at the base of the fourth leg appears to be more deeply bifid apically than in H. vittata, otherwise the branchial formulae of the two forms are in agreement. No differences could be found in the structure of the male pleopods, in the I9I4'J S.Kemp: Notes on Crustacea Decapoda. 117 proportions of the abdominal somites, or in the characters of the telson and uropods. I believe I am correct in referring these specimens to H. kilkenthali (de Man) ; at any rate I am unable to point to any features in which they differ noticeably from his lengthy descrip- tions. The examples recorded by Pearson in 1905 from the Ceylon pearl banks under the name of Nauticaris iinirecedens, Bate, almost certainly belong to the same species. N. iinirecedens , Bate, as de Man has pointed out, is a synonym of H. vittata ; but Pearson notes that in his specimens the rostral teeth are less numerous than in those described in the ' Challenger ' Report. The specimens in the Indian Museum were caught during the months of January and February and many of the females bear eggs. _ si.^_^ 9 ^_ Cheval Paar, Ceylon, I". Southwell. Maiiv, 2()-,^2 mni. 6 fathoms. The species is recorded by de Man from Ternate and Flores. Hippolysmata dentata, sp. nov. Plate VI, fig. 5. This species differs from H. vittata in the following parti- culars : — The rostrum, which is only slightly shorter than the carapace, extends beyond the apex of the antennular peduncle (fig 5). Dorsally it is provided with seven or eight teeth, the hindmost of which, as in vittata, is situated just in front of the middle of the carapace and is separated by a considerable interval from the next of the series. On its inferior margin it is furnished with six or sever teeth which are as large as those above. The pterygostomian pine on the antero-lateral angle of the carapace is much more prominent than in H. vittata, but is not nearly as large as the antennal. The eyes are short and reach only to half the length of the basal segment of the antennular peduncle; the cornea is a little wider than the stalk. The antennular peduncle reaches almost or quite to the apex of the antennal scale and its lateral process scarcely extends as far as the eyes' The form of the antennal scale is similar to that of H. vittata but in the larger (type) specimen the apical spine reaches well beyond the lamellar part. The oral appendages, maxillipedes and first peraeopods resemble those of H. vittata; in the chelae of the first pair the fingers meet only at the tips when the claw is closed. In the second peraeopods the carpus is composed of from 20 to 22 ' In thj smaller of the two examples this process is considerably shorter than the eyes, which themselves reach well beyond the middle of the basal peduncular segment. ii8 Records of the Indian Museum. [\^ol. X, segments ; the merus in the larger example is divided into eight segments and there are traces of sub-division in the ischium. The last carpal segment, the palm and the dactylus are almost equal in length. The last three peraeopods are longer than in H. vittata or H. kiikenthali. Those of the third pair reach beyond the antennal scale by the whole length of the carpus, propodus and dactylus; the fourth reach beyond the same point by the length of the last two segments and the fifth by the dactylus and one-half of the propodus. The usual spines are found on the ischium and merus ; in the third peraeopod there are two or three on the former and four on the latter. The dactylus in all three pairs is slen- der and curved and nearly one-third the length of the propodus. It bears a few very slender spines close to the base, but other- wise is wholly unarmed, offering a striking contrast to the same appendage in H. vittata (cf. figs. 5 and 8). In the proportions of the abdominal somites and in the characters of the telson and uropods H. denlata does not present any noticeable difference from its allies. Two specimens are preserved in the Indian Museum : — i"3o Off M. of Irrawaddy R., is'20' ., ,• . • r^ . 'rvur 7 ^, o ; T- r ' Investiq-ator. One, ^; mm. 1 \ Pl^. N., 94 55 E., 20 fms. * --^ ajy-s False Point Harbour, Orissa, ,, .■ . • r\ ,0 r> r r, 1 ' Invest lo-ator One, 18 mm. Bay or Bengal. * The colour of the species in life, according to a note found in the bottle containing the sinaller specimen, is as follows: — '^' Cara- pace and abdomen striped pink. Antennae and antennules pink. Thoracic appendages light pink," Hippolysmata ensirostris, sp. nov. Plate VII, figs. 1—4. The carapace, measured dorsally from the back of the orbit to the posterior margin, is a little less than half the length of the abdomen, excluding the telson. The branchiostegal walls are smooth in some specimens, in others punctate, sometimes rather closely so. The pter5'gostomian spine is prominent and is as large as the antennal (fig. i). The rostrum (figs, i, 2) is always longer than the carapace and in some specimens (presumably those in which it has escaped fracture throughout the animal's existence) is fully twice the length. Dorsall}' it bears from 11 to 16 teeth, of which the posterior 7 to 12 form an elevated basal crest, extending on to the carapace. The teeth on this crest diminish in size from before backwards. In front of the crest there are scarcely ever more than five widely separated teeth on the upper edge of the blade. The inferior margin is armed with 7 to 16 stout teeth which are close-set proximally. The rostrum is a little depressed basalh' ; but, after passing the second segment of the antennular peduncle, 1914 J ^- Kemp; Notes on Crustacea Decapoda 119 is slightly ascendant and thence to the apex is quite straight or (rarely) a trifle upturned. The carapace is bluntly carinate mid-dorsally in its anterior half and bears one, less commonly two, minute spinules behind the basal crest of the rostrum. The corneal portion of the eyes is, in dorsal view, only very little wider than the stalk and is smaller than in the preceding species. The antennular peduncle hardly reaches to two- thirds the length of the antennal scale ; the second segment is longer than the third and the lateral process, though it extends beyond the eyes, fails to reach the distal end of the segment. The antennal scale is unusually variable in form and ranges from three to rather more than three and a half times as long as wide. The distal end of the lamella always extends well beyond the spine which terminates the straight or slightly concave outer margin, and the flagellum is nearly twice the entire length of the animal measured from the tip of the rostrum to the apex of the telson. The mandibular palp bears neither incisor-process nor palp and the oral appendages are closely similar to those of H. vittata. The third ma:iillipede falls short of the apex of the antennal scale, the exopods reaching to rather more than half the length of the antepenultimate segment. The carpus of the first peraeopods is a little shorter than the chela, the dactylus is scarcely two-thirds the length of the palm and the fingers, when the claw is closed, are in contact throughout their length. In the second peraeopods the merus is indistinctly divided into from 7 to 11 segments, while the carpus is composed of from 12 to 17. The palm of the chela is shorter than the last carpal segment and is a little longer than the fingers. The last three pairs of peraeopods are provided with a variable number of spines on the ventral aspect of the merus Those of the fifth pair extend to two-thirds or three-quarters the length of the antennal scale. The dactylus varies considerably in length ; it is usually one-quarter or one fifth the length of the propodus ; but occasionally in smaller examples is longer (two-sevenths the length of the propodus). The dactylus (fig. 4) is furnished with a few small spinules posteriorly ; in several ovigerous females a small spine is also found near the apex ; but this is never sufficiently large to give it the characteristic appearance seen in H . vitiata and H. kukenthali. The epipods at the base of the first four pairs of peraeopods are strikingl}^ different from those found in the preceding species. They are short and rudimentary and entirely concealed from view by the downward growth of the pleurobranchs. 'q% ''% The sixth abdominal somite is one-quarter longer than the fifth. The telson (fig. 3) is about twice the length of the sixth somite and bears two pairs of dorsal spinules. Its lateral margins are concave, setose towards the apex, and terminate in a very narrow and acute point which reaches almost to, or considerably 120 Records of the Indian Museum. [Vol. X, beyond, the distal end of the uropods. It differs widely in shape from that found in the preceding species and there is no trace of the usual terminal spines. This very variable and, as it appears, abinidant species of Hippolysmata seems to be rather an outstanding form, differing markedly from any species of the genus with which 1 am acquain- ted in the peculiar characters of the rostrum and telson and in the rudimentary condition of the epipods. The following specimens are in the Indian Museum : — ^^f=i Madras. ... Two, 51 and 54 mm. -fo" Pondicherry. J. Wood-Mason. One, 64 mm. ''\o^ Colombo. J. .\nderson. Six. 50-79 mm. TYPES. ^%- Akyab, Lower Burma. V. Stoliczka. P'our, 52-60 mm. ^f{P Bombay. H. P. Mesurier. Two, 35 and 63 mm. var. punctata, nov. Plate VII, figs. 5—7. The rostrum in this form is nearly always more upturned distally than in typical ensirosiris (figs. 5,6). It bears from 8 to 13 dorsal teeth of which the posterior 4 to 8 form a basal crest. On the carapace a groove above the oral region, barely distinguishable in the typical form, is comparatively well-marked and a depression between the branchial and cardiac regions is always definite (fig. 5). The cardiac regions are somewhat swollen on each side of the middle line, so that the posterior third of the carapace is nearly flat dorsally. The branchiostegal walls are covered with a rather coarse pitting, the pits being very close and often confluent (fig. 7). The antennal scale is hardly ever more than three times as long as wide. The third maxillipedes reach as far as, or a little beyond, the apex of the antennal scale. The carpus of the second pair of peraeopods is composed of 15 to 22 segments and the fifth pair reaches beyond the antennal scale by at least the whole of the propodus and sometimes by as much as one-half of the propodus as well. The dactylus of this pair is longer than in most typical examples of the species, the propodus being only three and a half times its length. After careful examination I have come to the conclusion that this form is nothing more than a variety of H. ensir sins, for the points of difference are entirely matters of degree. The variety punctata appears to be an extreme form of ensirostris in which the areolation and pitting of the carapace is more definite, the legs longer and more slender and the basal crest of the rostrum composed of a smaller number of teeth. a 13+— 5 10 (Heen I., .Amherst, ■ ln\esti.gator.' l'"itt\-t\\ 0, 35-60 mm. 10 .11 37-t7 7 'I'enasscrim, Tlions^wa, liurma. Sandhcads, (^lans^cs delta. 1. H. Burkill. .\. J. Milncr. Three, 51-63 mm. Twent\-tour, 37-60 mm I9I4'J S. Kemp : Notes on Crustacea Decapoda. 121 Genus Merguia, nov. Carapace without supra-orbital or antero-lateral (pterygosto- mian) spines ; antennal spine present. Upper antennular flagellum uniramous. Mandible without incisor-process or palp. Third maxillipede without exopod. Neither epipods nor arthrobranchs at base of first four peraeopods. Carpus of second peraeopods composed of many (24 or 25) segments. This genus is founded to receive de Man's Hippjlyte oligodon, of which species the type and only known example is preserved in the Indian Museum. Examination of the mandible shows that both incisor-process and palp are absent (pi. VTI, fig. 8) and that in the number of segments in the carpus of the second peraeopods and in the sup- pression of the arthrobranchs at the base of the first four thoracic limbs it approaches the genera Lvsmata and Hippolysiiiata. From both these it is easily distinguished by the absence of the exopod on the third maxillipede and of the epipods at the base of the peraeopods. «, In addition the species differs from other Hippolytidae in two very peculiar features. The first of these is the enormous development of the second segment of the antennal peduncle, which reaches beyond the apex of the antennal scale : this feature is well shown in de Man's figure The second is the undivided condition of the distal endite of the second maxilla (pi. VII, fig. 9). Except in the Pasiphaeidae in which both endites are suppressed, the distal endite is, in the Caridea, always divided. Merguia oligodon (de Man). Plate VII, figs. 8,9. iSSS. Hi hpolvtc oligodon. tie Man, Journ. l.lnn. Soc,. XXII, j). ..'7, pi. xviii, Hu-.s. I -6. ,1 To de Man's detailed description there is little to add except as regards the characters of the oral appendages, noted above, the absence of the exopod on the third maxillipede and the suppression of the epipods at the base of the peraeopods. The specimen, as de Man noted, is not in perfect condition ; the antennules are broken off shortly above the base of the peduncle, but enough remains to render it almost certain that no additional ramus is present on the upper flagellum The flagellum is, indeed, very different in appearance to that found in Hippoly- smata^ for it is round in section and without setae, whereas in the preceding genus it is more or less oval at the base, apparently formed by the fusion of two rami, and bears numerous setae, probably olfactory' in function, on its inferior aspect. "2.-'''' Klphinsionc 1., .Mei;<.;ir, ArchiiJclayo. |. Anderson. Oni-, 2S mm. 122 Records of the Indian Museum. [Vol. X, SYNONYMIC LIST OF THE IN 1)0-PACII'TC SPKCIKS OF HIPPOI.YTIDAF. Genus Saron, Tliallwitz. Saron marmoratus i Olivier). See p. 84. Saron neglectus, de M;in. See p. 87. (ieiius Nauticaris, Hale. Nauticaris marionis, Bate. 1S8S. Xaiificaris iiKirlonis, Bate, R.;'p. ' C'halL'ns^er ' Macriira, p. (103, pi. cviii, 1902. Mevhippolyte diisfra/is, Hodgson, Rep. ' Southern Cross ' Crust., p. 233, pl. xxix. iyo2. Nauticaris marionis, Lenz, Zool. Jahrb. Syst., suppl. Bd. V, p. 735. i()o6. Nauticaris marionis, Caiman, Ann. Mao-. Nat. Hist. (71, XX'U, Prince Fldward I., Falkland fs., Auckland 1., Cavancha. Nauticaris stewarti 1 Thomson ). 1888. Nippolvtc ste-ivarti, Thomson, Trans. N. '/.. Inst., XX(, p. 259, pl, xiii, fig. I . 1903. Nauticaris stewarti, Thomson, Tnrns. 1,'nn. Soc. (2), \TII, p. 445, pi. xxix, fig. I. New Zealand. Genus Merhippolyte, Ixite. Mcrhippolytc calmani, Rcmji and Sc^v.ell. See p. 88. ■ Merhippolyte kauaiensis ( Rathbun) (see pp. 88. 8<)). !()()(). Spiroiitocaris kauaiensis, Rathbun, Bull. L'. S. Fish Comm. for 1903, XXHI, iii, p. 913, pi. xxiv, fig. 5. FLiw.'iiian Is. Merhippolyte orientalis. Bate. 1888. Merliippol vte oriental is, I5ale, Rep. Challenger Macrura, p. Ci2i. 1907. Merliippoivte orientalis. de Man, 'J'rans. Finn. Soc, Zool. C21, l.X, p. 426. on New Cniinea. The original description is .ilmost A';ilueless and tlie t\'pe specimen (fide Caiman, see de Man, loc. cit.) is in hopelossK' bad condition. ( ienus Ligur, Saivito. 1^585. Lignr, Sarato, .Monileur des Ftrangers, i.X, annec. n. 222, p. 2, (Nice)'. 1902. Parhippolyte, Borradaile, in W'illey's Z(H)1. Results, ]). 414. 1903. Lignr, Senna, Bull. Soc. entom. Ilal., ann. XXXIV, p. 319. ' I have not been able to consult this publication. I9I4'] S. Kemp : Notes on Crustacea Decapoda. 123 Ligur uveae ( liorradaile). 191)-'. Pdvhippolvte uveae, Bo'Tadaile, in W'illey's Zool. Results, \). 414, pi. tig's. 1 1, a-g. Loyalty Is. Cienu^ Alope, \\ hiic. Alope palpalis. White. See p. 8g. Alope australis, Baker. See p. gr . (iemis Spirontocaris, Bate. Spirontocaris alcimede. dc Man. \i)u(). spirontocaris alcimede, de Man. Ann. Mag. Nat. Hist. ('71, XVII, p. 4<'4- . 1907. Spirontocaris propiig)iatrix. de Man, Trans. Linn. Soc, Zool. (2), IX, p. 416, pi. xxxii, figs. 42-^6. I a pan. Spirontocaris geniculata (Slimpsoni. 1860. Hippolvte geniculata, Stinipson , Proc. .\cad. Nat. Sci. Philadelphia, P- ,u" iSgo. Htppolyte getnculata. Ortirann. Zool. Jahrb., .S\'sl.. \', p. 50,3, pi. xx.wii, figs. 3, ,^(/-/. H)o2. Hippolyte geniculata, Doflein, .Vbh. .\kad. Wi-s. .Miinchcn, XXI, iii, p. 636. 1902. Spirontocaris geniculata. '\athhun, Proc. L'. .S. Xat. Mus., .XX\'I, p. 45, fig. ig. Japan. Spirontocaris gracilirostris Stimpsoni. i860. Hippolvte griicil irosti-is. Stimp-.iin, Proc. Acad. .Sci. PlTil.idelphi.i. P- ,U- Spirontocaris grebnitskii, Ralhbun. igo2. Spirontocaris grcbnitzkii. Rathbun, ProL'. I'. S .\at. .Mas., XX\T, p. 44, fig. 18. japan. Spirontocaris jordani, R.ithbun. [yo2. Spirontocaris jordani, Rathbun, Proc. V . S. Nat. .Mus., .\X\T, p. 44, fig. 17". Japan. Spirontocaris leptognatha 1 Slimi^son 1. i860. Hippolyte leptognatha. .Stinipson, Proc. .\c,id. .Sci. I'liiladelphia, p. ,>4. i87g. Hippolyte leptognatha. xaw. Mieis, Proc. Zool. .Soc, pp. 22, 56. J.apan. 124 Records of the Indian Museum. [V^ol. X, Spirontocaris mororani, Ralhbun. 1902, Spirontocaris niororm/i, Rathbun, Proc. W S. Nat. Mus., XX\'I, p. 43. fig. 1(1. Japan. Spirontocaris ochotcnsis ^ Brandt). 1851. Hippolyte ochoteiisis, Brandt, in MiddendortT's Reise Sibiriens, II, Zool., i, p. 120, pi. V, fig. 17. i860. Hippolyte oclioteiisis, Stimpson, Proc. Acad. Sci. Philadelphia, p. 34. 1910. Spirontocaris ochotei/sis, Rathbun, Harriman Alaska Kxped., X, Crust., p. 71, text-fig. 26. Bering Sea to Sitka, Kamchatka, Okhotsk Sea, Japan. Spirontocaris orientalis de Man). 1890. Hetairocaris orientalis, dc Man, Notes Leyden Mus., XII, p. 1J2, pi. vi, fig. 6. 1890. Hippolyte ponapensis, Ortmann, Zool. Jahrb., Syst., V, p. 502, pi. xxxvi, figs. 20, 2od. 1892. Hippolyte ponapensis, de Man, Notes l^eyden Mus., XI \', p. 263. Caroline Is. Spirontocaris pandaloides (Stimpson). See p. 93 Spirontocaris pcctinifcra (Stimpson). , i860. Hippolyte pecti)iifera, Stimpson, Proc. Acad. Sci. Philadelphia, \). 35. Japan. Spirontocaris profunda, Rathbun. 1906. Spirontocaris profunda, ii.'ilhbun. Bull. V. S. i" ish C'omm. for 1903, XXIII, iii, ]). 914, pi. wiv, fig. 10. Hawaiian is. Spirontocaris propugnatrix, de Man. 1906. Spirontocaris propugnatrix, de Man, Ann. Mag. Nat. Hist. (7 I, XVII, p. 404. 1907. Spirontocaris propngjnitrix, de Man. Tnins. I. inn. Soc, Zool. (2), IX, p. 414, pi. xxxii, figs. 35-41. Japan. Spirontocaris rcctirostris (Stimpson). i860. J/ippolvte rectirosfris, Stimpson, Proc. Acad. Nat. Sci. Philadelphia, P- ?>^y 1902. Hippolyte rectirosfris, Doflein, .\l)h. Ak.'id. W'iss. Miinchen, XXI, iii, p. 637, pi. iii, fig. 7. 1906. Spirontocaris rcctirostris, de .Man, Ann. Mag. N,it. Hist. (7), X\'II, P- 4'>3- 1907. Spirontocaris rectirostris. de M;m, Trans. Linn. Soc, Zool. (21, IX, p. 41 I, pi. Nxxii, figs. 31-34. Japan. Cienus Thor, Kingslcy. Thor paschalis (Heller). See p. 94. 1914-] ^"^^ Kemp : Notes on Crustacea Decapoda. 125 (lenus Hippolyte, I.Crnli. Hippolyte acuta (Stimpson). 1860. I'irbiiis (wnttis, Stimpson, Proc. Acad. \at. Sci. [Philadelphia, p. 35- lyoC). Hippohfe acuta, Rathbun, Bull. l'. S. hish Conini. for 1903, XXIII, iii, p. yi_', pi. xxiv, fig. :;. I. ill C hiu Is.; Hawaiian Is. Hippolyte australicnsis (Stimpson). See p. 98. Hippolyte bifidirostris, .Mieis. 1876. ]'ii-hiiis bifidirostris, Miers, Ann. Mag. Nat. Hist. (4J, XVII, p. 224. 1876. Virbitis bifidii-ostns, Miers, Cat. N. Z. Crust., p. 81, pi. .\i, fig. i. 1903. Hippolyte bifidirostris, Thomson, Trans. Linn. Soc, Zool. (2), VIII, p. 443, pi. xwiii, figs. 13-16. New Zealand. Hippolyte orientalis, Heller. See p. 97. 1861. Hippolyte orientalis, Heller, Sit/c-ber. .Akad. W'iss. Wien, XI. IV, p. 27"7. ? 1875. I trbiiis proteits, Paulson, Rech. Crust. Mer Rouge, p. 109, pi, x\iii, fig. I, pi. X, figs. 2-^. 1906. Virbiiis oriental is, Nobili, Ann. Sci. nat., Zool. (gj, IV, p. 1,1^. Red Sea. Hippolyte ventricosus, II. Milne- Kclwards, See p. i)(). (ienus Latreutes, Stimpson. Latreutes acicularis, Ortmann. 1890. Latreutes acicularis, Ortmann, Zool. Jahrb., S}'sl., \', 0. y)6, pi, xx\ii, figs. 6, 6 d-k, () n. 1002. Latreutes acicularis, DoHein, .\bh. Akad. W'iss. Miinchen .\XI p. 638. 1907, Latreutes acicularis, de Man, Trans. I inn. Soc, Zool. ,^21, I.\ p. 421. Japan . Latreutes anoplonyx, Kemp. -See p. i'>4. Latreutes (?) ceyloncnsis, Pearson 1 see p. 99), 1905. Latreutes ceyloueusis, Pearson, Ceylon Pearl Oyster Rep., IV, p. 8[, pi. ii, fig. 7. Ceylon. Latreutes compressus (Stimpson). i860. ^Rhynchocyclus compicssus, Stimjjson, Proc. .\cad. Nat. Sci. Philadel- phia, p. 28. Port Jackson, .Australia. 126 Records of ike Indian Museum. [\'ol. X, Latreutes dorsalis, Slinipson. 1860. Latreutes dorsalis. Stiinpson, }^roc. Acad. Nat. Sci. Philadelphia, p. -7. Hakodadi, |apan. Latreutes laminirostris. Ortmaiin. i8yu. Latreutes lanii iii rostris, Ortmann, Zool. Jahrh., Sysl. \', p, 506. 1907. Latreutes hiniini rvstris, c\e Man, Irans. I. inn. Soc, Zoohiii, IX, p. 422. Jaixm. Latreutes mucronatus (Stimpsoni. See p. loi. Latreutes phycologus, Xobili. 19()> Latreutes phycologus, Nobili, Bull. Mus. Hist, nat., p. 159. 190O. L^atreates phvco/ogiis, Nobili, Bull. sci. I"" ranee. Beig,, Xi,, p. 41. pi. ii, figs. 6, 6 d. Persian Chilf. Latreutes planirostris (l)e Haani. 1849. Cvclor/i viic/iiis plajiirostris, l)e riaan, hauna Japonica, ("rust., 'p. 175", pi. xlv, fig. 7. i80(). Rhviickocycliis planirostris, Slinipson, Proc. Acad. Nat. Sci. Phila- delphia, p. 27. 1879. Rhy)ic]iocyclus planirostris. Miers, Proc. Zool. Soc, p. 55. 1890. Latreutes planirostris, (Jrtmann, Zool. J.ihrb., Syst., \', p. 505, pi. xx.Kvii, figs. 4d-l, 4 n. 1902. Platyhema planirostre, Kathbun, Proc. l". S. N.it. Mus,, XXN'l, 1907. Latreutes planirostris, cle .M;in, 'frans. l.inn. Soc, Zool. (2), IX, p. 421. Japan. Latreutes pristis 1 Nobili 1. 1899. Platybema pristis, Nobili, Ann. Mus. ci\-. ( ienova (2 1, .X.X, p. 233 (p. 4 of reprint). Beagle Bay, New Guinea. Latreutes pygmaeus, Nobili. See p. 91). Genus Tozeuma, Slinipson. Tozeuma armatum, Paulson. See p. io(). Tozeuma clongatum (Baker:. 1904. Angasia elongata. Baker, Pnins. Koy. Soc S. .Vustrali.i, XX\ III, p. 147, pi. xxvii, figs. 1-4. Port X'iclor, S. Australi.i ; 15 fms. I9I4-] ^"^ Kemp: Notes on Crustacea Dccapoda. 127 Tozeuma crythraeum, Nobili. U)04. Tozciinid eryflirucKm, Nobili, Hull. Mus. Hist. nat. Paris, p. 2\\. 1906. Aiigasia eryftiraca, Xohili, Ann. Sci. nat., Zoo!, (qi, 1 \', p. 44. Rud Sea. Tozeuma kimbcri (Baker). 1904. Aiigusia kimberi. Baker, Trans. !^oy. .Soc. S. AiLStralia, XXN'III, p. !4(), pi. xxvii, fi-^-. s. Port W'illungvi, S. A'.jstr;ili,-i ; 4 fms. Tozcuma lanceolatum, Stimpson. 1860. Tozcii»ia laiiceoliitani, Stimpson, Proc. Acad. Nat. S( i. Pliiladeli^hia, . P- -7- 1879. Tozciinw Idiiccoldfinii. Kin(rslc\-. Proc. Acad. Nat. Sci. Philadelphia, P- 4i.^^- Hono'kong;. Tozeuma pavoninum (Bate). 1863. Ai/giisia pavoni)in, Bale, Proc. Zool. Soc, p. 4()8, pi. \l, ho-, i. St. \'inccnt's Gulf, Austr;ili<'i ; 4', fms. Tozeuma robustum 1 Baker). 1904. Aiigasia robiistu, liaker. Trans. Roy. Soc. S. .\ustrali.i. XW'IIl, p. 150, pi. x.xviii, hgs. 1-8. St. N'incent Gulf, S. .Australia, 10-12 fms. Tozeuma tomentosum (Baker). 1904. Aiigasia fomeiitosa, Baker, Irans. Roy. Soc. S. .\u4ralia. XW'IIl, p. 152, pi. xxix, figs. 1-4. S. .Australia ; 20 fms. Genus Gclastocaris, Kemp. Gelastocaris paronac i Nobili 1. See p. 107. Genuv Mimocaris, .Nobili. Mimocaris heterccarpoides, .^lobili. 1903. Mimocar-is /ieterocin-/>oii/i's, Nobili, Boll. Mus. Torino.. .X\'lll,no. 447, p. 6, fig. 2. Borneo. Genus Lysmata, l^'^^o. Lysmata scticaudata (Risso). 1816. Melicerfa seticaitdata, Risso, Hist. n.at. ("rust. Nice, p. 1 10, pi. ii, fig. I. 1825. LysTiiafa seticauda. Guerin, Knc}cl. method., X, p. t^2';>. 1826. f.ysiiiata seticaiidata, Risso, Hist. Nat. de TKurope Merid., V, p. 62. 1863. Lysmata seticauda. Heller, Crust, siidlich. Europa., p. 234, pi. viii, fig. I. 1902. Lysmata seticaiidafa , Senna, Bull. Soc. enlom. Ital., xxxiv, p. 326. Mediterranean ; Atlantic Coast of France .and .Spain ; Channel Is. W 8^8 Boo^, CrusT. NlW-.t. ^'^^/O'- '^- 128 Records of the Indian Museum. [Vol. X, var. ternatcnsis, de Man. '.' 1849. Lysniafa seticaiidata, l)c Haan. Fauna Japonica, Crust., p. i/f), pi. xlv, fig. 13. (f . deiitatiis on plate). 188S. Lysiuata seticaiidata, de Man, Arch. f. Nalurgesch., LIU, i, p. 492. ? 1890. Lysmata seticaiidata, Ortmann, Zool. Jahrb. Syst., \', p. 507 (partini). 1902. I.ysmata seticaiidata. deMan, Abhandl. Senck. naturf. Ges. Frankfurt, XX \', p. 846. Ternate ; Amboina. Japan ? Lysmata trisctacea (Heller). 1861. Hippolvte ti'isetacea. Heller, \'erhandl. /ool-bot. Ges. W'ien, XI, p. 29. 1861. Lvstnata piisilla. Heller, Sitz-ber. Akad. Wiss. W'ien, XIJV, p. 287, pi. ill, fig. 26. 1888. Lvsmata piisilla, de Man, Arch. f. Naturgesch., FHI, i. p. 49,^ Red Sea. Lysmata chiltoni, Kemp. See p. 1 10. Genus Hippolysmata, Slimpson. Hippolysmata amboinensis, de Man. 1881. Hippolysmata vittata \ar. a/uboiiiensis, de Man, Arch. f. Naturgesch., LHI.'i, p. 494. 1907. Hippolysmata a>iihoiiieusis, de Man, Trans. Linn. Soc, Zool. (2), IX, p. 426. Amboina. Hippolysmata acicula, Rathbun. 1906. Hippolysmata acicula, Rathbun, Bull. L^ S. Fish Comm. tor 1903, XXIII, iii, p. 912, pi. -xxiv, fig. 6. Hawaiian I3. Hippolysmata dentata, Kemp. See p. 117. Hippolysmata cnsirostris, Kemp. See p. 1 18. var. punctata, Kemp. See p. 120. Hippolysmata kiikcnthali, de Man. See p. 115. Hippolysmata multiscissa, .Vobili. 1906. Hippolysmata multiscissa. Nobili. .\nn. .Sci. nal. Zool., Paris ^()), I\'. p. 47; pi. ii, fig. 5. Red Sea. Hippolysmata paucidens, Rathbun. I9u(). JJippotysmata paucidens, Rathbun, I'lull. I'. S. I'ish Lomm. tor ii;o3, XXIII, iii, p. 91,^, pi. xxiv, fig. 4. Hawaiian Is. 1914-] S. Kemp : Notes on Crustacea Decapoda. 129 Hippolysmata vittata, Stimpson. See p. 1 13. Genus Merguia, Kemp. Merguia oligodon (de Man). See p. 121. Incertae sedis. 1888. Naiitican's futilirosti'is, Bate, Rep. Challenger Macrura, p. 6(i6, pi. cix, fig. I. igo^. Naiif lean's fiitiltrosfi'is, Pearson, Ceylon Pearl Oyster Rep., IV, p. 81, pl. ii.fig- 8. Japan, Ceylon. 18^9. Htppolyte gracilipes, Randall, Journ. .Acad. Nat. Sci. Philadelphia (i), VIII, p. 142. Hawaiian Is. 1871. Hippolvte gravi, Cunningham, Trans. Linn. Soc, XXVII, p. 49(1, pl. Hi, fig. 8." Port Otway. 1858. Hippolvte ignohilis. Kinahan, Journ. Roy. Dublin Soc, 1, p. 131. Port Philip, Victoria. 1830. Hippolyte leacliii. ducrin, Vow dc ' l.a Coquille', II, pt. 2, p. 37. Caroline group. 1904. Virbius {^) jactans, Nobili, Bull. Mus. d'Hist. nat., Paris, p. 2},'.). I9')(), Virbius {!')jacf(ius, Nobili, .\nn. Sci. nat., Zool., Paris (9), IV, p. 37, pl. ii, fig. 2. Red Sea. [888. Lafrenfey planus, Bate, Rep. Challenger Macrura, p. 584, pl. Ix.xix. fig"- 5- Philippine Is. 1837. Hippolyte qiiovaiii/s, H. Milne-Kdwards, Hist. nat. Cru.st., H, p. 37^, New Guinea. 1837. Hippolyte serrat/is. H. Milne-Kdwards, Hist. Nal. Crust., II, p. 377. " Baie de Jarvis. 1837. Hippolvte spiiiicaiid us, \\. Milne-Kdwards, Hist. nat. Crust., H,p. 37S. 1882. Hippolvte spinicaiuliis, Haswell, Cat. .\nstralian. Crust., p. 184. New Holland. 1888. Latreiites iiiudeiitatiis, l^ate. Rep. Challenger Macrura, p. 506, \y\. Ixxi.x, fig. (). Philippine is. EXPLANATION OF PLATE L Alope palpalis, White. Fig. I. — Left second peraeopod of a specimen in the Indian Museum : X 6. ,, 2. — Right second peraeopod of the same specimen : x 6. Alope australis, Baker. ,, 3. — Anterior part of a specimen from Burma ^ dorsal view :X3. ,, 4. — Right second peraeopod of a large male showing abnormal segmentation : X6. ,, 5. — The processes on the thoracic sternum of the same specimen : X 5. Tkor paschalis, Heller. 6. — An ovigerous female from S. India in lateral view : X 12. 7. — Carpus and chela of second pei 'opod of a specimen from Florida : X 16. 8. — Same segments of a specimen from S. India : X25. 9 —Same segments of another specimen from S. India showing abnormal segmentation : X 30. 10. — Third peraeopod of male : X 15. Rec. Ind. Mus., Vol X ,1914. Plate 1. D Sa^cm, & A.CbaTrdharv, del ALOPE. THOR. EXPLANATION OF PLATE II. Hippolyte ventricosus , Milne-Edwards. Fig I. — An ovigerous female from S. India in lateral view : X 6. ,, 2. — Antennal scale : X 20. ,, 3. — Carpus and chela of second peraeopod : X 30. Hippolyte varians, Leach. ,, 4 — Antennal scale : X 16. ,, 5. — Carpus and chela of second peraeopod : X20. Hippolyte australiensis (Stimpson). ,, 6. —Carpus and chela of second peraeopod : X 20. Latreutes pygmaeus, Nobili. ,, 7. — An ovigerous female from S. India in lateral view : X7^. ,, 8. — Rostrum, antennule, etc. of a male in lateral view : X 18. Rec. Ind. Mus, Vol-X, 1914. Plate 11. S. C Mon.d\il, & A.ChcnTdhary, djtd. HIPPOLYTE, LATREUTES. Be.nr05e.Cc.no, Derby. EXPLANATION OF PLATE III. Latr elites pvgtnaeus, Nobili. Fig. t. — Rostrum of a female : X 7. ,, 2. — Rostrum of another female with abnormallv deep blade : X 8. ,, 3. — Rostrum of a male : X 9. ,, 4. — Antennule of a female : X 22. ,, 5. — Antennal scale of a female : > io|. ,, 6. — Dactylus and part of propodus of fifth peraeopod : X 33. ,, 7. — Apex of telson ; X 24. Latreutes mucronatus (Stimpson). ,, 8. — Rostrum of a female with four dorsal spines on the carapace : X 13 ,, 9. — Rostrum of another female with an unusually large number of teeth : X 13. ,, 10. — Rostrum of a male : X 10^. ,, II. — Rostrum of another male with two dorsal spines on the carapace, resembling the type specimen of L. gravieri , Nobili : X 12. ,, 12. — Antennule of a female • X 20. ,, 13. — Antennal scale of a female : X 20. ,, 14. — Antennal scale of a male : X 20. ,, 15. — Antennal scale of another male : X 20. Rec. Ind. Mu£.,Vol.X, 1914. Plate 111. 11. 14. .S C Mondul * AChow-diiary, del. LATR EUTES. Bemrosv. CoHo., Dist by EXPLANATION OF PLATE IV. Latreutes mucronatus (Stimpson). Fig. I. — An ovigerous female in lateral view : X 9|. ,, 2. — A male in lateral view : X 9|-. Latreutes anoplonyx , sp. no v. ,, 3. — Type specimen, an ovigerous female, m lateral vnew : X 3. ,, 4. — Antennal scale : X 10. ,, 5. — Apex of telson ; highly magnified. Rec. Ind. Mus,YoIX, 1914. Plate IV A ChcfTrdfiarv dfil. LATREUTES. Bemrose. Collo, Derby EXPLANATION OF PLATE V. Gelastocnris paronae (Nobili). Fig. I. — An ovigerous female in lateral view : X 9^. 2. — Antennal scale : X 15. 3. — A portion of margin of antennal scale seen from below, showing plumose setae : X 75. 4. — Second maxillipede : X 15. 5. — Third maxillipede : X 15. 6. — First peraeopod : X 15. 7. — Qiela of first peraeopod, further enlarged. 8. — Second peraeopod : X 15. 9. — Third peraeopod : X 15. 10 — Last abdominal somite and telson in dorsal view : X 8. II. — Apex of telson, further enlarged : X 50. Rec. Ind. Mus,Vol.X, 1914. Plate V. A-Chandhary, dd. GELASTOCARIS. BefTirose.Collo, Derby EXPLANATION OF PLATE VI. Lysmata chilioni, sp. nov. Fig. r. — Rostrum, carapace, etc. of the type specimen : X 4. ,, 2. — Antennule of another specimen : X 8. ,, 3. — Antennal scale : X 12. ,, 4. — Last two carpal segments and chela of second peraeopod : X 40. Hippolysmata dentata, sp. nov. ,, 5. — Rostrum, carapace, thoracic appendages, etc. of the type specimen 1X5. Hippolysmata vittata, Stimpson. -Pterygostomian angle of carapace : X 34. 7 8 9 10 — Chela of first peraeopod : X 14. — Dact^dus of fifth peraeopod : X 34. — Telson : X 8. — Rostrum, carapace, etc. of a specimen from the Persian Gulf with unusually long rostrum : X 6. Hippolysmata kiikerithali , de Man. I I. — Chela of fir.st peraeopod ; X 14. Rec. Ind. Mus., Vol. X ,1914. Plate VI. D. Bagchi, & A Chowdhary, del. LYSMATA, HIPPOLYSMATA. EXPLANATION OF PLATE VI L Hippolysmata enstrosiris , sp. nov. -^' Fig, I. — An ovigerous female in lateral view : x 2. ,, 2. — Rostrum of another specimen : X 3. ,, 3.— Telson : X 5. ,, 4. — Dactylus and part of propodus of fifth peraeopod : X 16 Hippolysmata eiisirostris var, punctata, nov. ,, 5. — Carapace, rostrum and frontal appendages in lateral view ; X 3. ,, 6. — Rostrum of another specimen : X 4. ,, 7. — A portion of the carapace in the vicinity of the antennal spine, showing the pitting of the surface : X 16. Merguia oligodon (de Man). ,, 8.— Mandible : X 22. ,, 9. — Second maxilla : X 16. tc. Ind, Mu s, Vol. X, 1914 Plate Vll D. Ba^chi, & A Chowdhary, (M. ifose, CqUo., Derby HIPPOLYSMATA, MERGUIA. Author's Copy. RECORDS of tbc INDIAN MUSEUM (7\ JOURNTVL OF INDmN ZOOLOGY) Vol. XII, Part VIII. DECEMBER, 1916. Page „„. (Notes on Crustacea Decapoda in Ibe Indian Museum, VI, VII. 5. Kemp 355 Calcutta : PUBLISHED BY ORDER OF THE TRUSTEES OF THE INDIAN MUSEUM. PRINTED AT THE BAPTIST MISSION PRESS. 1916. XX. NOTES ON CRUSTACEA DECAPOD A IN THE INDIAN MUSEUM. VI. Indian Crangonidae. By Stanley Kemp, B.A., Superintendent^ Zoological Survey of India. (Plate VIII.) The number of Crangonidae known from Indian seas has been considerably increased by recent work in shallow water on various parts of the coast. In dealing with the additional material that has come to hand I have thought it useful to include references to all the known Indian forms and to construct keys to facilitate the identification of the species of Pontophihis and Aegeo7i. Six species hitherto unknown are described, all belonging to the genus Pontophilus, while, thanks to the assistance of Dr. W. T. Caiman, I have been able to rectify certain errors in the nomen- clature of two species of Aegeon. In a previous paper in this series ' I expressed the view that Philocheras, Stehhmg{ = Cher aphilus, Kinahan, partim) could not be sustained as a distinct genus, but must be merged in Pontophilus. In examining the new forms of this genus a point hitherto over- looked has come to light, namely, that in certain species there are considerable differences between the sexes in the form of the pleopods. The modifications of these appendages are not only of interest as evidence of the affinities of the different species, they also, as it appears to me, afford a valuable clue to the origin of the various genera of the family and point to lines of descent very different from those suggested by Ortmann in 1890. I have thought it best to discuss the structure of these appendages and the phylogenetic conclusions which may be derived from them under a separate heading at the end of the paper. In all eighteen species of Crangonidae are now known from Indian waters, ten belonging to the g^nns Pontophilus, six to Aegeon and one each to Prionocrangon and Crangon. Genus Pontophilus, lycach. The six undescribed Indian species of this genus were obtained, two from Kilakarai at the northern end of the Gulf of Mannar 1 Rec. Ind. Mms.,YI, p. 5 (19") 356 Records o/ the Indian Museujii. [Vol. XII. and four from Port Blair in the Andamans. One of the new forms, P. incisus, is a very close ally of the Atlantic and Mediterranean P. scuiptus, the remainder are sharply distinguished from all species previously described by well-marked characters found in the sculp- ture of the carapace and abdomen and in the form of the rostrum , lateral process of the antennule, antennal scale and first two pairs of legs. In some of the species there are considerable differences be- tween the sexes in the form of the last four pairs of pleopods, a feature discussed in detail on p 381, and other sexual distinctions of an unusual nature are met with in P. lowisi and P. candidus. In the former the antennal scale, which is remarkable for the possession in both male and female of a series of spinules on its outer margin, shows wide differences in form in the two sexes. In the latter a conspicuous spine in the mid-dorsal line of th3 carapace is present in the male and absent in the female, a remarkable distinction when the great constancy of the armature of the carapace in other spe- cies is remembered. The ten Indian species of Pontophilus may be distinguished thus : — I. — First peraeopods with rudimentary exopod ; second pe- raeopods verj' short, not reaching distal end of merus of first pair, ti.fir chela well formed with curved fingers ; lateral urocess of antennular peduncle styli- form, much longer than broad. A. Median carina of carapace with two spines ... gracilis. Smith. B. Median carina of carapace with three spines ... (T^v^^?. Smith. II. — First peraeopods without exopod ; second peraeopods longer, reaching beyond carpus of first pair, their chela ill-formed with parallel fingers; lateral process of an- tennular peduncle not styliform, usually subquadrate and broader than long. A. A median longitudinal carina on carapace and on 3rd, 4th and 5th abdominal somites [ros- trum bread distally, anterior margin squarely truncate or concave]. 1. Outer margin of antennal scale armed with a spine or a series of spinules in addition to a terminal spine. 'I. Carapace with five carinae bearing- spines; a single additional spine on outer margin of antennal scale, placed near base ; merus of first peraeopods with a single spine at distal end of outer margin ; first four abdominal somites with strong lateral sculpture b. Carapace without spines and without lateral carinae ; a series of spinules on outer margin of antennal scale ; merus of first peraeopods with three spines at distal end of outer mar- gin ; lateral sculpture of first four abdomi- nal somites feeble 2. Antennal scale without additional spines on outer margin ; [rarapace with spines and lateral carinae ; first four abdominal somites with strong lateral sculpture.] ... B. No median longitudinal carinae on carapace or abdomen. incisiis, sp. nov, lowisi, sp. nov, . nov. ii. Carapace not pubescent with only a single tooth in mid-dorsal line. a. Three pairs of lateral teeth on carapace ; lateral process of antennular peduncle anteriorly pointed; "thumb" of sub- chela formed of a single articulated tooth ... .. ... plebs, sp. nov. 18. No lateral teeth on carapace ; lateral pro- cess of antennular peduncle anteriorly- truncate; "thumb " of subchela formed of two teeth, closely juxtaposed and not articulated ... ... ... Iwiidersoiii. Kemp. b. Rostrum exceedingly small, eyes contiguous ; carapace without teeth in median line ; dactylus of second peraeopods very slende*- less "than half the breadth of fixed finger ... f^nrvirosfyis.%\~>. now Pontophilus gracilis^ Smith. 1901. Pontopliilits gracilis, Alcock, Cat. India)i deep-sea Crust. Macrura and Anomala, p. 115. 1005. Pontophilus gracilis, Stebbing, Marine Invest. S. Africa, IV, ]). 49, pi. XXV. Pontophilus abyssi, Smith. i<)Oi. Pontophilus abvssi, Alcock. Cat. Indian deep-sea Crust. Macrura and Anomala, p. 1 16. Pontophilus incisus, sp. iiov. (Plate viii, fig. i.) The rostrum is longitudinally channelled ; its sides are almost parallel and its distal border, in dorsal view, is strongly concave. The ac'-ual apex is rounded, but is abruptly deflexed at a right angle a^id can therefore be seen only from in front. The sides of the rostrum and the orbital margins are clothed with long hairs which partially conceal the eyes. On the carapace a shallow groove extends transversely across the base of the rostrum. In the mid-dorsal line there is a rather obscure interrupted carina composed of four short ridges. The first of these ridges ends anteriorly in a conspicuous tooth just behmd the trans- verse groove mentioned above; the second, which is very feebly developed, usually terminates in a minute denticle ; the third is 358 Records of the Indian Museum. [Vol. XII, well elevated and its margin in lateral view is a little uneven; the fourth is distinct and ends abruptly. The first lateral carinae are not parallel, but converge anteriorly. Each is composed of a num- ber of short ridges ending anteriorl}^ in denticles. The foremost ridge is short and terminates in a comparatively large tooth placed a little behind the first of those in the median line. The small teeth or denticles on the two ridges po.sterior to it are also well formed, while the remainder are minute and can only be seen with dilficult5^ At the posterior end of the carapace there are a few additional short ridges, some bearing denticles, between the median and the first lateral carinae. The second lateral carina is also Fig. I. — Poiifophiliis iiicisiis, sp. nov. a. Antennule. c. First peraeopod. b. Antennal scale. d. Second peraeopod. composed of interrupted ridges, the foremost ending in a stout hepatic tooth situated in advance of the primary median tooth. The ridge flanking the hepatic tooth is comparatively long and is succeeded by another, also of considerable length, which ends in a conspicuous tooth; the remaining ridges, three or four in number, are short and each may or may not bear a small denticle. There are sharp orbital and branchiostegal spines, the latter being the longer and extending beyond the level of the rostral apex. Except for the ridges, the entire carapace is covered with a fine pubescence and also, in many cases, bears several upstanding tufts of long setae. igi6.J S. Kemp : Notes on Crustacea Decapoda. 359 The corneal portion of the eye is reniform in outUne. The basal segment of the antennular peduncle (text-fig. la) is longitud- inally keeled below and usually bears a small tooth near its prox- imal end. Its lateral process is transversely oblong with the outer distal angle somewhat drawn out and projecting forwards. The second and third segments of the peduncle are extremely short, the two combined being scarcely half the length of the first. The antennal scale (text-fig. ih) is broadest near the base and is narrowed strongly towards the apex. It is about three times as long as broad and the short spine which terminates its outer margin extends by almost its whole length beyond the apex of the lamella. On the outer margin, at the end of the proximal quarter is a single stout tooth, recalling that found in P. sculptus , but placed much nearer the base. The margin behind this tooth is strongly convex and that in front of it slightly concave. The outer maxillipedes reach beyond the tip of the antennal scale by almost the entire length of the ultimate segment. The first peraeopods (text-fig. ic) are a little shorter than ihe outer maxillipedes and do not possess exopods. The spine on the outer margin of the merus is strong and, as in P. sculptus, is terminal in position. On the distal margin of the carpus there are two external spines. The propodus is nearly three and a half times as long as wide and the "thumb" of the subchela is ex- ceptionally large and strong. At their base the first peraeopods are separated, in both sexes, by a sharp forwardly directed sternal tooth. The second peraeopods (text fig. id) are clothed with long hairs and reach beyond the end of the carpus of the first pair by almost the entire length of the chela. The carpus is about one fifth shorter than the merus and nearly one fifth longer than the chela. The chela, as in allied species, is weakly constructed, without incurved claws at the apex. The fingers are of equal breadth and length and the palm is exceptionally short, occupying only about one fifth the length of the chela. The slender third peraeopods reach beyond the tip of the antennal scale by the two terminal segments and by one third the length of the carpus. The latter segment is nearly one and a half times the length of the merus, twice the length of the ischium and one and a half times the length of the propodus and dactylus combined. The propodus is equal in length with the ischium and is two and. a half times as long as the dactylus. In the last two peraeopods, which are similar, the tour distal segments are practically glabrous ; those of the fourth pair reach beyond the antennal scale by the length of the dactylus. The merus in this pair is a trifle longer than the dactylus, four fifths the length of the propodus and nearly twice as long as the carpus. The dactylus is almost three quarters the length of the propodus. The abdominal segments are deeply grooved and incised, much as in P. sculptus, the depressed portions being pubescent and the raised portions glabrous. On the first five somites the sculpture is 360 Records of the Indian M itseuvi. [Vol. XII, transverse for the most part ; but there is a sharp longitudinal mid- dorsal carina in the posterior three quarters of the third somite, a pair of juxtaposed carinae, fused posteriorly, in the same position on the fourth somite and a similar pair of carinae, slightly diver-" gent posteriorly, on the fifth. On the sixth somite the only sculp- ture consists of a pair of longitudinal carinae separated by a broad flat interspace. The pleura of the first four somites are pointed below, bluntly in the female, rather more sharply in the male. The pleopods show marked sexual differences. In the male the endopod of the last four pairs is comparatively well developed and possesses an appendix interna. In the female the endopod is reduced in size and is extremely small in the case of the last pleo- pod : the appendix interna is present in the second pair, but is much smaller than in the male : in the third and fourth pairs it is quite rudimentar}' and from the fifth it is entirely absent. The outer uropod is shorter than the inner and is very slender, nearly four times as long as broad. The telson is scarcely longer than the inner uropod and is also very slender. It is sulcate above and bears two pairs of small dorso-lateral spinules. The lower edges are fringed with long setae and distally it terminates in a sharp point, flanked by a pair of short spinules and bearing two pairs of long finely plumose setae. Large females reach a length of 18 mm.; the males are smaller, not exceeding 15 mm., and are apparently much less abundant. The eggs are about o"4XO'3 mm. in longer and shorter diameter. Pontophilus incisus is a remarkably close ally of P. sculptus, Bell, a species known from the Mediterranean and from the French and British coasts.' In all conspicuous characters there is a very close similarity between the two forms, but differences in detail are sufficiently numerous to justify their specific separation. In P. incisus there is only one strong tooth in the mid-dorsal line of the carapace, whereas in P. sculptus there are almost invariably two. In P. incisiis, also, the antennal scale is narrower and the tooth on its outer margin is placed near the base instead of in the mid- dle. In both species the spine on the outer margin of the merus of the first peraeopods is terminal and not sub-terminal as in some other species of the genus ; in P. incisus, however, the anterior edge of the merus between this spine and the articulation of the Carpus is entire, bearing only a few hairs, whereas in P. sctdptus two or three additional spines are found in this position. In P. incisus, moreover, the lateral process of the antennular peduncle is more pointed distally, the subchela is more slender, the palm of the second peraeopods shorter and the dactyli of the last two peraeopods comparatively longer. In a previous paper* I have remarked on the presence of the appendix interna in P. sculptus ; but I failed to notice that in the ' I have compared the Indian species with specimens of P. sculptus from the Irish Sea, ■^ Kemp, Rec. lud. Mus., VI, ]). m f loi i i 1916.] S. Kemp: Notes on Crustacea Decapoda. 361 development of this appendage there were marked sexual differ- ences. The condition in P. sculptus is, in fact, precisely the same as has been described above in the case of the related Indian form. As regards the characteristic tooth on the outer edge of the antennal scale, I noted, in the paper cited above, that it was apparently absent in a single Mediterranean example of P. sculp- tus preserved in the Indian Museum. Further examination of this individual shows that the tooth is indeed present, but situated at the proximal end of the scale. The specimen is, in fact, in all points identical with the types of P. incisus and differs from P. scz^Z/'iJws in the characters noted above. It is labelled "Mediter- ranean" without more precise localit}' and is said to have been received from E. Cornalia, from whom Wood-Mason obtained a large number of Mediterranean Decapoda. From Heller's descrip- tion,* however, it seems clear that the true P. sculptus occurs in the Mediterranean, for in his description of the antennal scale he says "am Seitenrande ausser dem endstandigen stachel mit einem zweiten beilaufig in der Mitte." It is probable therefore that some mistake has arisen and that the specimen, said to have been found in the Mediterranean, was in reality obtained in Indian waters. In life Pontophilus mcisus is closely mottled with dark grey and brown, the colouration being apparentl}^ protective. All the specimens in the collection are from the Andaman Is. — —-^^ Andamans, 20 fms. 'Investigator.' i, 10 mm. -9-°-fg^^^ Port Blair, Andamans, S. Kemp. 41, 7-18 mm. 2-12 fms. The specimens from Port Blair, among which the types of the species (9070/ ro) are included, were obtained in the channel off Ross I. on a rough bottom composed of sand, stones, shells and coral. Pontophilus lowisi, sp. nov. (Plate viii, fig. 2.) The rostrum is longitudinally channelled above ; its lateral margins are curved and strongly divergent distally. The anterior margin is very broad and, in dorsal view, a little concave. The true apex is sharply deflexed ; it has a rounded margin and is visible only froin in front. On the carapace there is no trace of the transverse groove be- hind the rostrum which occurs in most species. In the mid- dorsal line there is a longitudinal carina which extends close up to the base of the rostrum. Throughout the greater part of its length this carina is obscure; but for a short distance just behind the middle of the carapace it is sharp and well defined and owing to its greater elevation is distinct in lateral view. A feeble groove runs obliquely forwards and downwards on either side of the cara- Heller, Crust, si'td/icli. Eiiropa, p. 228 ('1863'). 362 Records of the Indian Museum. [Vol. XII, pace terminating just above the sharp branchiostegal spine. Thi^ spine reaches to the level of the rostral apex and extends far in advance of that which defines the outer orbital angle. Except for those on its frontal margin the carapace is entirely devoid of spines and, except for that in the mid-dorsal line, it is without carinae. The carapace does not appear to be pubescent. The basal segment of the antennular peduncle is about one and a half times the length of the second and third combined; its lateral process is oval (text-fig. 2a). The antennal scale differs notably in the two sexes In the female (text-fig. 2h') it is scarcely more than twice as long as broad Fig. 2. — Puiitophiliis lo-ivisi, s.p. no\'. Auteiinule. b'. Antennal scale of female. Antennal scale of male. c. First peraeopod. d. Second peraeopod. and the lamella, though narrowed, is of considerable breadth at its distal end. In the male (text-fig. 26), it is almost three times as long as broad and the lamella slopes sharply away from the base of the distal tooth. The outer margin in both sexes bears numerous spines, in this respect differing from all known species of the genus. In the female the margin is straight or very shghtly concave and bears some 12 or 13 spines which increase in size from behind forwards. In the male the margin is strongly sinuous, convex in the middle and concave towards the distal end. It bears from 9 to 11 spines, similar to those of the female, but they are restricted to the basal convex portion of the margin and do not extend on to the concave part nearer the apex. igi6.] S. Kemp : Notes on Crustacea Decapoda. 363 The third maxillipedes reach ahnost or quite to the end of the antennal scale. The combined length of the two subequal distal segments is not greater than that oi the antepenultimate. The latter segment bears a few small spinules at the distal end of its lower margin and the exopod, when naturally flexed, reaches but little beyond the middle of its length. The first peraeopods (text-fig. 2c) reach a little further than the third maxillipedes. The merus at its outer distal angle bears three stout curved spines and there is a single external spine near the distal end of the carpus. The subchela is a little more than three times as long as broad; the "thumb" is large and sharp as in P. incisiis. The first legs are separated at their base by a large forwardly directed sternal tooth. The second peraeopods (text- fig. 2d) are clothed with long hairs and reach beyond the carpus of the first pair; the merus is as long as the carpus and chela combined, the carpus is one and a third times the length of the chela and the fingers are a little less than one and a half times as long as the palm. Each finger bears a slender spine at its apex, but the spines are not curved and the claw IS apparently without cutting edges. The fixed finger is a little broader than the dactylus. The third peraeopods reach beyond the antennal scale bj^ the length of the two ultimate segments. The proportions are much the same as in P. incisus, but the propodus and dactylus are com- paratively a trifle longer, their combined lengths being almost three quarters that of the carpus. The fourth and fifth pairs bear scattered setae on the propo- dus. The fifth reach beyond the scale by about half the length of the dactylus. The propodus in this limb is two and a half times the length of the carpus and is a quarter longer than the subequal merus and dactylus. Seen under a high power of the microscope the anterior margins of the merus and carpus have a roughened appearance, as though they were studded with small tubercles. The abdomen in a dried specimen shows faint indications of sculpture, very shallow transverse grooves and elevations being visible on the first four segments. In the posterior half of the second somite and over the greater part of the third and fourth there are sharp longitudinal mid-dorsal carinae. Those on the second and third somites are simple, but that on the fourth is longitudinally grooved in the middle and thus has the appearance of a double carina fused at either end. There are two short dorsal carinae on the fifth somite and a pair of similar widely-separated carinae, which are exceedingly obscure, on the sixth. The pleura are not pointed inferiorly. The pleopods of the male resemble those of P. incisus, the endopod of the last four pairs is well developed and carries an appendix interna. In the female, as in P. incisus and P. sculptus, the endopod is greatly reduced and the appendix interna^ found in those species in a rudimentary condition on the second, third and fourth pairs, is entirely suppressed. 364 Records of the Indian Miisenin. [Vol. XII, The outer uropod is a little shorter than the inner and bears long setae on its outer, as well as on its inner margin; it is a little more than three times as long as broad. The telson reaches about to the apex of the inner uropod ; it is deeply sulcate above with two pairs of dorso-lateral spinules and in the form of its apex. resembles P. incisus. This species is, I believe, the smallest known Macruran. It is smaller even than P. sahsechota, Kemp, the largest individual in the collection, an ovigerous female, being slightly less than 7" 5 mm. in total length. The eggs are comparatively large for such a small species; when not eyed and to all appearances freshly extruded they are about 0*3 4X0*27 mm. in longer and shorter diameter; when fully eyed and ready to hatch they measure about 0-48 X 0*36 mm. Pontophilus lowisi is perhaps distantly related to P. hidentatus , de Haan ', and P. japonicus, Doflein*, but from both these species it differs conspicuous!}' in the form of the carapace and in the presence of a series of spines on the outer edge of the antennal scale. The colouring of the species differed considerably in specimens from different localities. Individuals found on a muddy bottom were for the most part densely pigmented with grey and brown, t^'e last abdominal somite and tail-fan being colourless except for a dark transverse band on the latter. Specimens from sandy ground were much lighter in colour, often quite pale and sometimes with one or two transverse brown bands. In one example from this type of bottom the pigmentation is very peculiar, the carapace being deep amber brown, the abdomen white with transverse bars of brown on the fifth somite and tail-fan and the antennules bright red. "'""10"'^'" Port Blair, Andamans, 3-12 im.s. S. Kemp. 69, 4'5-7'5 mm. Specimens were found off' Ross I. and in various other parts of the harbour, but were most abundant at the inner end on a muddy bottom. The types of the species are numbered 9074/10 in the Indian Museum register. With this species I have associated the name of Mr, R. F. Lowis, Deputy Superintendent of Port Blair, to whom I am much indebted for assistance during my visit to the Andamans. Pontophilus sabscchota, Kemp. 191 1. Foiitopliil Ks sabsecliotd. Kemp, AVr. /// in the middle of the posterior half. Behind the antennal spine, which reaches almost as far for- ward as the rostrum, there are two small teeth placed one behind the other in the latitude of the first tooth of the mid-dorsal series. Below these there is a stout hepatic tooth which overhangs a deep sulcus — the lateral continuation of the transverse post-rostral 368 'Records of the Indian. Museum. [Vol. XII, groove, especially well marked in this portion of the carapace. The branchiostegal spine is strong and extends forwards be^'-ond the level of the eyestalks. Behind it is another small tooth, placed further forward than any others of the dorsal series. Exclusive of the spines on its frontal margin, there are in all eleven teeth on the carapace: none of these teeth form the terminations of carinae. In the male each of the last three thoracic sterna bears a median keel, which ends anteriorly in a small tooth : these keels are absent in the female. The first and second pairs of legs are adjacent at the base in the male and are not separated by the antrorse spine found in P. hendersoni. Fig. 4. — Ponfophiliis pilosiis, sp. nov. a. Antennule. c. First peraeopod. b. Autennal scale. d. Second peraeopod. The eyes are stout and short. In both sexes the distal mar- gin of the stalk, on its upper and inner side, is produced beyond the cornea to a small but conspicuous papilla. The basal segment of the antennular peduncle (text-fig. 4a) bears a stout ventral spine and another at the distal end of its outer margin. The lateral process is peculiar in form. It is fully as long as broad and is furnished anteriorly with two spines, the outermost the largest and the inner bearing a small internal spinule. The outer flagellutn does not appear to be appreciably stouter in the male than in the female and is shorter than the peduncle. The antennal scale (text- fig. 46) is broad, its breadth in a large female being more than half its length. The outer margin is con- vex and terminates in a spine which does not reach as far forward as the lamella and is separated from it by a broad U-shaped gap. 1916.J vS. Kemp : Notes on Crustacea Decapoda. 369 The outer maxillipedes are clothed with long setae and reach beyond the end of the antennal scale by almost the entire length of the ultimate segment. The first peraeopods (text-fig. 4c) are a little shorter than the outer maxillipedes and are not provided with exopods. The spine on the outer margin of the merus is terminal and on the anterior margin between it and the articulation of the carpus there is another smaller spine. The carpus is short ; the inner margin is lobed and bears coarse setae, while on the outer margin are two spines. The breadth of the hand, measured near its base, is about one third its entire length. The second peraeopods (text-fig. 4^) reach to the carpus of the first pair. The carpus is two thirds the length of the merus and is as Ions: as the palm and half the length of the fingers. In the chela, which as in the preceding species is weakly constructed and with- out cutting margins or terminal claws, the palm is about one seventh longer than the dactylus. The fixed finger is noticeably shorter than the dactylus and both fingers bear long setae. The slender third peraeopods reach beyond the antennal scale by about the length of the two ultimate segments. The merus is a little shorter than the ischium and a little longer than the pro- podus. The carpus is one and two thirds the length of the merus and is one fifth longer than the propodus and dactylus combined. The fourth and fifth legs are rather densely clothed with hairs. The merus, carpus and propodus are subequal and the dactylus is a little more than half their length. The abdominal somites are quite smooth and are covered with a fine pubescence similar to that on the carapace ; the margins of the pleura are rounded. The inner ramus of the last four pairs of pleopods is comparatively well developed in the male and carries an appendix interna ; in the female it is reduced and no trace of this appendage is to be found. The outer uropod is shorter than the inner and is nearly three times as long as broad. The telson is one and a half times the length of the last abdominal somite; it is provided with two pairs of dorso lateral spinules and its lower margins are ciliated. The apex is similar to that of P. parvirostris. Pontophilus pilosus is sometimes conspicuously banded in life with dark brown. In examples from very shallow water there is a narrow transverse band at the posterior end of the carapace and others, rather broader, on the second and fourth abdominal somites and across the middle of the telson and uropods. Individuals obtained at a depth of two fathoms were marbled with brown pig- ment mixed with a certain amount of pure white, the carapace being sometimes of a dull reddish-brown. In all the specimens there was a dark spot at the distal end of the subchela. The specimens were obtained at the northern end of the Gulf of Mannar. — -fo" Kilakarai, Ramnad S. Kemp. 2 juv., 3 (^, 4 ?, dist., S. India. S'5-I3 """''''• Type.s. 170 Records of the Indian Museum. [Vol. XII, Pontophilus plebs, sp. nov, (Plate viii, fig. 5.) The rostrum is longitudinally channelled; its lateral margins are convergent and meet in a narrowly rounded apex. The cara- pace is devoid of pubescence and is not carinated. It bears seven teeth, one situated mid-dorsally, close behind the rostrum and separated from it b^' a shallow transverse groove, and three pairs on either side. The latter comprise a stout hepatic tooth, on a level with that in the middle line, and two small teeth, both in advance of the hepatic, placed close together behind the sharp spinous branchiostegal angle. In the anterior half of the carapace there are obscure longitudinal furrows above and below the hepa- tic tooth. The basal segment of the antennular peduncle (text-fig 5^) is longer than the two following combined, externalh^ the distal Fig. 5. — Pontophilus plebs, sp. nov. a. Antennule. c. First peraeopod. b. Antennal scale. d. Second peraeopod. margin is produced to an acute tooth. The lateral process is more or less oval in shape, longer than broad, and is anteriorly pointed The second and third segments are broader than long. The an- tennal scale (text-fig. 56) is only twice as long as broad ; the outer margin is straight and terminates in a tooth which is far exceeded by the distal end of the lamella. The third maxillipedes reach beyond the scale by about half the length of the ultimate segment. The first peraeopods (text- fig. 5c) are scarcely shorter. The outer edge of the merus termin- ates in a large tooth and the margin between this tooth and the articulation of the carpus is unarmed. The carpus bears a stout external tooth. The hand is about two and a half times as long as wide and the single tooth which forms the ' thumb' of the sub- iQr6.] S, Kemp : Notes on Crustacea Decapoda. 371 chela is articulated, as in P. candidits, and not fixed as in most species of the genus. The second peraeopods (text-fig. ^d) reach little beyond the end of the merus of the first pair. The merus is one third longer than the ischium and more than twice the length of the carpus. The dact3dus is longer than the palm and conspicuously longer than the fixed finger, the fingers are of equal breadth and each bears a single stout seta at its apex. The whole limb is rather thickly clothed with hairs. The slender third peraeopods reach beyond the end of the antennal scale. The carpus is a little longer than the merus and as long as the propodus and dactylus combined. The fourth and fifth peraeopods are shorter than the third. In the fifth pair the dactylus and propodus are subequal ; the carpus is a little longer than the propodus and a little shorter than the merus. In the male the last three segments of the thoracic sternum are carinate, the carina of each ending anteriorly in a small tooth. These carinae and teeth do not appear to exist in the female and in neither sex is there a sternal spine extending between the bases of the third legs. The abdominal somites are smooth, without sculpture or pubescence; their pleura are rounded inferiorly. In the male the endopod of each of the last four pairs of pleopods is comparatively well developed and possesses an appendix interna. In the female there is no appendix interna and the endopod is very small in the second and third pairs, quite rudimentary on the fourth and absent from the fifth. The telson, including the terminal spines, reaches a little be- yond the end of the inner uropod. It is not sulcate above and bears two pairs of lateral, spinules between which are two rows of exceedingly minute denticles. These denticles can only be seen if the telson is viewed obliquely from the side under a microscope ; they extend from the base almost to the distal end and may be as many as sixteen in number. The apex is closely similar to that of P, incisiis. The outer uropod is shorter than the inner. It bears setae on its external margin and is fully three and a half times as long as broad. The largest of the nine specimens obtained is only 6 mm. in length. No ovigerous females were found and it is possible, there- fore, that all are immature. The characters are, however, quite distinctive and experience with other species leads me to believe that they would not change appreciably with further growth. The specimens were pale in life with sparse black dendritic chromato- phores. ^%-- Po't Blair, Andamans, 2 fms. S. Kemp. 9, 45-6 mm. Types. The specimens were all found together in Phoenix Bay on a bottom of muddv sand. 372 Records of the Indian Museum. [Vol. XII, Pontophilus hendersoni, Kemp, 1915. Pontophilus hendersoni. Kemp, Mem. Ind. Mns., V. p. 261, pi. xiii, fig. 8. The characters given in the key on pp. 356 and 357 will suffice to distinguish this species from all other Indian representatives of the genus. P. hendersoni is very closely allied to P. megalocheir (Stebbing) ', obtained at depths of 25 and 37 fathoms on the coast of S. Africa. The African form agrees in nearly all respects with that from the Indian coast; in particular, there is (as shown in Stebbing's figures) an almost complete identity of form in the structure of the subchela, the 'thumb ' being composed of two closely juxtaposed spines in- stead of the single one found in all other species of the genus. There are, however, certain discrepancies between Stebbing's account and my own, which, if substantiated, are sufficient to justify the separation of the two forms. The apex of the lamella of the antennal scale is, for instance, much more acute in P. megalo- cheir than in P. hendersoni , extending much further beyond the apex of the spine that terminates the outer margin (c/. Stebbing's pi. Ixxix, fig. a.i. and my text-fig, 25a). Stebbing also has made no mention of the small tubercle found in P. hendersoni on the dor- sum of the third abdominal somite and the armature of the telson is totally different. In P. megalocheir the telson is furnished at its apex with a long and slender tooth, flanked by a pair of plu- mose setae {v. Stebbing, pi. Ixxix, fig. T). In P. hendersoni the apex consists of a triangular plate with a minute spinule on either side and with two pairs of plumose setae arising from beneath it {v. Kemp, text-figs. 25 g, g'). Since the original account of P. hendersoni was published, additional specimens have been taken in the open sea on the Orissa Coast, a circumstance which tends to confirm the view that the occurrence of the species in the outer channel of the Chilka Lake was purely accidental and that it is not normally an inhabitant of brackish water. 8|Sfi Puri, Orissa coast, 4-4! fms. S. Kemp. 3, 6^-9 mm. Pontophilus parvirostris, sp nov. (Plate viii, fig. 6.) The rostrum is extremely small, far less conspicuous than in any other species of the genus. It recalls that found in many Pagurids and consists merel}' of a small flat triangular prolonga- tion of the median part of the carapace. The apex is acute and does not reach further than to one third the length of the eyestalks. The antennal spine is sharp and extends far be^^ond the level of the rostral apex ; the branchiostegal spine is long and reaches 1 Philocheras megalocheir, Stebbing, Ann. S. African Mus., XV, p. 71, pi. Ixxix (1015). This work was not received in Calcutta in sufficient time to enable me to refer to it in my account of the Decapods of the Chilka l.aki-. I9i6.] vS. Kemp : Notes on Crustacea Decapoda. 373 almost as far forwards as the ends of the eyestalks. The latter spine is flanked by a short carina which runs obliquely downwards and backwards and, above its posterior termination, in the anterior quarter of the carapace, there is another well marked spine. Ex- cept for this spine and for the carina mentioned above the entire surface of the carapace is smooth, save for a feeble transverse depression behind the frontal margin. On the sides of the carapace, most numerous below the branchiostegal carina, are some long silky hairs. The thoracic sterna of the female are not carinate. The eyes are elongate and their inner margins are contiguous ; the cornea is well pigmented and its length in dorsal view is about equal to that of the stalk. The basal segment of the antennular peduncle (text-fig. 6a) bears two stout teeth, one situated ventrally and one externally Fig. 6. — Poiifophilus parvirosti'is, sp. no\'. a. Antennule. c. First peraeopod. b. Antennal scale. d. Second peraeopod. at its distal end. The lateral process is elongate oval and is fur- nished with a minute point anteriorly. The second and third seg- ments are about equal in length and the outer flagellum in the female is about as long as the peduncle. The antennal scale (text-fig. 66) is about one and two thirds as long as broad; the outer margin is very slightly convex and terminates in a stout tooth which does not reach nearly as far for- wards as the apex of the lamella. The outer maxillipedes reach beyond the apex of the scale by more than half the length of the ultimate segment. The first peraeopods (text-fig. 6c) reach as far forwards as the third maxillipedes and do not possess exopods. The merus bears a terminal (not sub-terminal) spine at the distal end of its outer margin. On the outer and inferior aspect of the carpus there is a sharp spine ; the inner angle is produced and is provided with a 374 Records of the Indian Museum. [Vol. XII, tuft of coarse setae. The basal breadth of the hand is little more than one third its entire length. The "thumb" of the subchela is stout and strongly deflected outwards. On the inner surface near the base of the propodus there is the usual tuft of coarse setae. The second peraeopods (text-fig. 6d) reach about to the end of the merus of the first pair. The chela is a trifle longer than the carpus and is remarkable in that the dactylus is extremel}'- slender, less than half the thickness of the fixed finger. As in allied forms the chela is ver^^ weakl}' constructed and is without terminal claws or definite cutting edges. The palm is about two thirds the length of the fingers and the propodus on its outer margin is densely fringed with long setae. The slender third peraeopods reach beyond the scale by the whole length of the two ultimate segments. The merus is a little longer than the ischium and a little shorter than the propodus and dactylus combined. The carpus is twice the length of the ischium. The fourth and fifth peraeopods are similar and stouter than the third. The merus is a little longer than the subequal carpus and propodus and about three times the length of the dactylus. The segments are rather densely clothed with hairs. The abdominal somites are quite smooth, without carinae or grooves, and the margins of the pleura are rounded below. The sixth somite is about equal in length with the telson. The inner ramus of the last four pairs of pleopods is very short and does not possess an appendix interna. The uropods are half as long again as the telson and the exopod is nearly four times as long as broad. The telson is rather broad at the base, but much narrowed at the apex. The margins are setose and there are two pairs of dorso- lateral spinules. The tip is triangular and sharply acute ; beneath it three pairs of spinules arise, the innermost two thirds the length of the intermediate pair and two and a half times as long as the outer. The colour in life of Pontophilns parvirostris was pale, mottled and spotted with dark umber, tending to maroon at the sides and on the appendages and forming distinct blotches on the pleura of the first, fourth and sixth abdominal somites. The specimens are registered thus, — «a«_Q Kilakarai, Ramnad dist., S. India. S. Kemp. 4?, 9-14 mm. Types. Genus Aegeon, Guerin Meneville. 1888. Ponfocaiis, Bate, Rep. ' Challenger' Macriira, p. 495. 1900. Aegeon, Stebbing, Marine Invest. S. Africa, I, p. 50. 1901. Aegeon, Alcock, Cat. Indian deep-sea Crttst. Macnira and AnoDiala, p. 117 (including subgenus Farapontocaris p. 120). All the described forms of this genus are represented in the collection of the Indian Museum. Three of them, Aegeon orien- talis, Henderson, A. haheren, Doflein.and A. lacazei, Gourret, are intermediate in character between the more typical species of the geuus and those which Alcock referred to the subgenus Parapon- T916.] vS. Kemp : Notes on Crustacea Decapoda. 375 tocaris; the latter term should therefore lapse. Aegeon orientalis agrees with Parapotitocaris in the complete absence of the hepatic groove and in the arrangement of the carinae on the first and second abdominal somites and resembles typical Aegeon in the very broad antennal scale and in the possession of strong median spines on the abdominal sterna. Aegeon habereri and lacazei are closely allied forms ; in most respects they agree closely with typical species of the genus, but they resemble Parapontocaris in the sculpture of the first two abdominal somites and in the elongate form of the anten- nal scale. In all six species of Aegeon are known from Indian waters; they may be distinguished by the following key : — I. Second lateral carina of carap.ice interrupted anteri- orly by a well defined hepatic groove; lateral parts of ist and 2nd abdominal somites irregularly lobecl, with- ciut sharp longitudinal keels continuous with those on carapace. A. Median carina of carapace with 4 teeth ; two or three tubercles, forming an oblique transverse row, between median and ist lateral carinae ... cafaphractits (Olivi). B. Median carina of carapace with 8 or g teeth or serrations ; surface between carinae of cara- pace smooth, withotit tubercles. 1. Marginal carina of carapace smooth ; two lobules separated by a \ertical fur- row on either side of median carina of 2nd abdominal somite ... ... pcjuiata. Bate. 2. Marginal carina of carapace serrulate; a sinuous longitudinal ridge, entire and not divided by a furrow, on either side of median carin.'i of ?nd abdominal somite ... ... ... pi'opeiisalata, Bate. II. Second lateral carina of carapace not interrupted, hep- atic groove absent ; lateral parts of ist and 2nd ab- dominal somites with sharp longitudinal keels conti- nuous with those on carapace. A. 1st and 2nd lateral carinae of carapace with 7 teeth, marginal with 7 to 9 ; antennal scale as broad as long ... ... .._ orientalis, Henderson. B. ist lateral carina of caiapace with 4 teeth, 2nd lateral with 3 to 6, marginal with 2 or 3 ; antennal scale much longer than broad. 1. 2nd lateral carina of carapace with 5 or 6 teeth, marginal with 3 ; median carina of 2nd abdominal tergum bispinous ... aiidaDKniensc (\\'ood-Mason). 2. 2nd lateral carina of carapace with 3 teeth, marginal with 2 ; median carina of 2nd abdominal tergum unispinous ... heiigalense I Wood -Mason). Aegeon cataphractus (Olivi). 1900. Aegean catuplwactus, Stebbing. Mmi/ie Invest. S. Africa, I, p. 50 {^itbi syi!.'). 1905. Aj.egeon cataphractus, Pearson, Ceylo)i Pearl Oyster Fish., Macriira p. 89. 376 Records of the Indian Museum. [Vol. XII, Except that the teeth on the carapace are blunter and that the abdominal sculpture is a little less sharply defined, I can find no difference between the two Indian specimens and others of similar size from the Mediterranean. Characteristic of A. calaphractus are the supernumerary tu- bercles between the longitudinal carinae of the carapace. Between the median and uppermost carinae are two or three tubercles arranged to form an oblique transverse row, which commences in the middle of the carapace and extends forwards and outwards on either side. Between the first and second lateral carinae there is a single tubercle placed on the posterior edge of the hepatic groove. Though both the Indian examples are small these tubercles are clearly visible. The occurrence of this species in India is interesting, for very few sub-littoral Decapoda are common to the Mediterranean and to Indian waters. Miers, however, states that the species prob- ably occurs at Senegambia, while vStebbing records it from the Cape of Good Hope, so that there is reason to believe that the distribu- tion is continuous round the x^frican coasts. In Indian waters A. cataphractus appears to be very scarce. Pearson has recorded it from the Ceylon Pearl Banks and there are two specimens in the Indian Museum, both obtained on the west coast of the peninsula : — Anjii 26 mi. W. S. W. of Honawar, N. ' Inxestigator. ' i?. 15111111. Kanara dist., Bombay Pres., 28 fins. Karachi. W. T. Blaiifcord. i^J, 23 mm. )i 3 1 Aegeon pennata (Bate). 1888. Po)itocni'i.s pennata, Bate, Rep. ' Challenger ' Ma crura, p. 44.9, pi. xci. 1895. Pontocaris pennata, Ortm.-iiin, Proc. Acad. Sci. Pliiladelphia, P- 175- 1 901. Aegeon affi)ie, Alcock, Cat. Indian deep-sea Crust. Macritra and Anomala, p. 188, and Illiist. Zool. 'Investigator,^ pi. li, figs. 3, 4. 1914. Aegeon obsoletum, Balss, Ahh. math.-pJiys. Klasse Baver. Akad. iViss. Mfinc/ien. Suppl. Bd. II, p. 70, pi. i, figs. 3. Alcock, when describing Aegeon affine, suggested that the species might prove to be identical with Bate's Pontocaris pennata. The description and figures of the latter species being inadequate, the point could only be determined by actual comparison of speci- mens. In order to settle the question I sent co-types of A. affine to Dr. Caiman, who, with his usual kindness, readily undertook to give me an opinion. He informs me that Alcock's suggestion is correct and that there is no doubt that the two forms are specific- ally identical. An example of Aegeon obsoletum^ determined by Balss, has been received in exchange from the Munich Museum ; it was ob- tained in vSagami Bay, Japan, at a depth of 50-100 m The in- dividual agrees precisely with Indian specimens of A. pennata. In addition to the characters noted by Alcock for the separa- tion of this species from A . medium { = A . propensalata. Bate), igi6.] S. Kemp : Notes on Crustacea Decapoda. 377 there is a marked difference between the two in the sculpture of the second abdominal somite. In A. propensalata, on either side of the middle line, there is a broad sinuous ridge which extends obliquely throughout the length of the somite. In A. pennata this ridge is broken in two by a deep vertical furrow. Dr. Caiman has kindly sent me the following notes regarding the types obtained by the ' Challenger ' — " The three specimens of P. pennata differ among themselves in the form of the rostrum and other characters. In two specimens the rostrum is relatively short, bifid at tip, and with the lateral spines as large as in ^. medium. In the third specimen the rostrum is longer, sharp-point- ed, and with very small lateral spines. In this last specimen also there is a tendency towards a softening of the inequalities of the general surface, i.e. the keels and ridges are not so prominent. In particular the two lobules on either side of the median carina of the second abdominal somite are not sharply defined, although the vertical furrow separating them is distinct." The following records of occurrence in Indian waters may be added to those given by Alcock : — 4_a_ti Persian Gulf, 26°2o'3o" N.. ^4°52'3o" E., 35 fms. ... ... ... 'Investigator' Five. ^%^ Persian Gulf. 26°33' N.. 52°23' E., 40 fms. ... .. ... .. One. i-Vo-^ Arabian Sea, 24°26'5o" N.. 66°35'5o" E., 35 fms. ... ... ... ,, Seven. ^-\^^ Coromandel coast, i4°25' N., 8o°i5'45" E., 12 fms. ... ... ... ,. Two. liOL-_S. 2037-9 j 2 3 9.T-4.oj.. Vls_7-92_ 1 Ganjam coast, 26-93 fms. " Twenty-two. W-S 28 rai.^S.W. of Puri. Orissa, 25 fms. ... ,, Three ^V-^' Off Gangetic delta, 2o°i8' N., 90=50' E., 65 fms. ... ... . . ,, One. ^y^j" Off Tennasserim coast, i3°27'3o" N., 97°37' E , 50 fms. ... ... ,, Two. iLU'o Off Cheduba. Arakan coast, 20 fms. . .. One. According to the labels the individual from the neighbourhood of the Gangetic delta was '• grey, touched with dark brown and green marks", while some of those from the Ganjam coast were irregularly banded with lichen green and mottled pink. On the Indian coasts A . pennata is evidently common ; it has been found at depths ranging from 12 to 93 fathoms. The type specimens were obtained by the ' Challenger ' in the Arafura Sea, south of New Guinea, 8° 56' S., 136° 5' E., at a depth of 49 fathoms. Balss, under the name A. obsoletum, records numerous specimens from Japan from depths of 80 to 150 metres. The species is ap- parently one of wide Indo-pacific distribution. Aegeon propensalata (Bate). 1888. Pontocaris prupejisalata. Bate, Rep ' Challenger ' Macfiini, p. 46;, pi. xc, figs. 2, 3 ; pi. l.xx.w, fig. 5. 1895. Pontocaris propensalata, Ortmann, Proc. Acad. Sci. Philadelpliia. P- 175 ^y8 Records of the Indian Musewn. [Vol. XII, i8yo. Poiitocaris mcifici, Alcock and .XndL'fson, .lini. Mug. Xaf. Hist. (7), III, p. 282. 1900. Poiitocaris propensalafa. Whiieleiige, Mem. Aiisfni/ian Miis.. \\ . p. 198. 1901. Aegeoi/ inediiiiii, Alcock, Cat. Indian deep-sea Crust. Macriira and Anouiala, p. 120, and I/lust. Zool, ' Investigator,' pi. xli, Hg. 6. In this case also I am indebted to Dr. Caiman for the elucida- tion of the synonymy. Dr. Caiman has kindly compared co-t3'pes of A. medium with the type of Bate's P. propensalata and has sent me the following note on the subject. — " 1 cannot find any differ- ence between the type of P. propensalata and A. medium. The sculpturing of the abdominal somites is less sharp in the former and the serration of the supramarginal carina of the carapace is very obscure — as it tends to be in the smaller of the two speci- mens of A. medium that I have examined." The only specimens in the Indian Museum are those described by Alcock from the Andaman Sea, 55-66 fathoms. Bate's type specimen was obtained off the Ki Is., south of New Guinea, 5°49' 15" S., 132° 14' 15" E., at a depth of 140 fathoms, and Whitelegge has recorded the species from 50 fathoms in Botany Bay. Aegeon orientalis, Henderson. 1893. Aegean orientalis, Henderson, Trans. Linu . Sac , Zool. (2), V, p. 446, pi. xl, figs. 16, 17. Three specimens in rather poor condition from the Persian Gulf and the Andamans evidently belong to this species, which does not appear to have been recognised since it was first described more than twenty years ago. The spinulation of the carapace agrees exactl}^ with Hender- son's description except that the serrations on the marginal carina vary in number from 7 to 9. The abdominal sculpture also agrees with the original description ; but there are two longitudinal carinae on either side of the second abdominal somite, and the five carinae on the first somite, as well as the median carina on the second, end anteriorly in sharp spines. These spines were perhaps worn away in the type, which is larger than any of the three specimens here recorded. Although, as Henderson has remarked, the species bears a rather marked resemblance to A. caiaphr actus, it is not in reality a very close ally of that species. As has already been pointed out it is intermediate in character between the more typical species and those that Alcock referred to the subgenus Parapontocaris. Pearson's suggestion that A. orientalis is merely an extreme -v^iri^t.- tion oi A . cataphractus ^ is certainly incorrect. A. orientalis may readily be distinguished (i) by the complete absence of the hepatic groove, (ii) by the smaller number of serrations on the marginal carina of the carapace, (iii) by the sharp longitudinal lateral carinae of the first two abdominal somites and (iv) b}^ the presence of only a ' Pearson, Ceylon Pearl Oyster Fisheries, Macriira, p. 89 (1905). 1916,] S. Kemp : Notes on Cviistacea Dccapoda. 379 single retrorse spine behind the middle point of each of the sub- median carinae of the last abdominal somite. The spines on the first two abdominal somites, if their presence proves to be con- stant, will also serve to distinguish the two forms. I think it improbable that the specimens from deep water off the Hawaiian Is., recorded by Miss Rathbun as Egeon orientalis ', are correctly referred to this species. In the examples in the Indian Museum the middle tooth of the median carina of the cara- pace is not smaller than the rest and the denticulation of the second lateral and marginal carinae is also different. Moreover, the third and fourth abdominal somites though strongly sculptured, only bear a single lateral longitudinal carina. These carinae, which are submedian in position and are clearly shown in Henderson's figure, are sinuous and towards the hinder end of the somite are directed oblir|uely outwards; that on the third is entire, while that on the fourth is interrupted in the middle. There are certainly not two lateral carinae on the third and three on the fourth as in Miss Rathbun 's description. The specimens examined are registered as follows: — ii^-L Persian Gulf, 26°22' N., 56°i(/ E., 'Investigator.' (i (^ , 18 mm.' 48-49 fms. I I $ , 15 mm. ~'-}o^^ Port Blair, Andamans. J. Wood-Mason. i (^ . 14 mm. The type and only other known example of the species is re- corded by Henderson from the Gulf of Martaban. Aegeon andamanense (Wood-Mason). 1901. Aegean {Parapoiifocaris) (Uidainiiiieiise. Alcock, Cat. Indian deep- sea Crust. Macriiva and Anomala. p. 121, and lUusf. Zool . ' Investi- gator,' Crust., pi. ix, fig". 2. Aegeon bengalense (Wood-Mason). 1901. Aegean (Parapontocaris) bengalense, .VK'ock, Cat. Indian deep-sea Crust. Macrura ami A)iomala, p. 122, and Illust. Zoal. ' Investi- gator,' Crust., pi. ix, fiq-. I. 1912. Aegeon {Parapontocaris) ijeuga/ense, Kemp and Scwell, Rec. Ind. Mus., VII, p. 22. Genus Prionocrangon, Wood-Mason. Prionocrangon ommatostercs, Wood-Mason. 1901, Prionocrango)! a»unatosteres, .\lcock. Cat. Indian deep-sea Crust. Macrura and Anoinala, p. 12,^, and lllust. Zool. 'Investigator,' Crust., pi. ix, fig. 4. Genus Crangon, Fabricius. Crangon crangon (Linnaeus). I have compared the Indian specimens with examples from Plymouth and the only appreciable distinctions that I can find are ' Rathbun, Bull. U.S. Fish Coniin. for 11)03, p. ()ii (1906). 380 Records of the Indian Museum. [Vol. XII, that in the Indian form the rostrum is narrower and distinctly- longer, reaching almost to the end of the eyes {cf. text-figs, ya, b) and that the sixth abdominal somite is less distinctly grooved in- feriorly. There is the closest resemblance between the two groups of specimens in the form of the subchela and antennal scale. The characters yielded by the rostrum and last abdominal somite may ultimately afford grounds for the recognition of the Indian form as a distinct subspecies, but in my opinion are insuffi- cient for specific distinction. A number of forms very closely allied to the common European species have been recorded from Japan; Miss Rathbun ', indeed, has reported the presence of C. crangon itself at Rikuoku (Rikuchu) and Hokkaido. Balss', the most recent author to discuss the Japanese forms, notes that Brashnikow ■'' (writin:; in Russian) has established the fact that C. crangon crangon does not occur in A A CL'. Fig. 7. — Ci'diigo)! crcuigoii (I. inn.). Anterior portion of carapace, rostrum and eyes-; (a) of an Indian specimen : (ft) of a specimen from Plymouth. Japanese waters. He, however, gives a summary of the characters of C. affinis, de Haan, C. propinquus , Stimpson, C. hakodatei, Rathbun, C. consohrinns, de Man, and C. cassiope, de Man, and remarks that in the collections that he himself has examined these characters are inconstant, even in specimens from a single gather- ing. He regards the last four of the names just mentioned as synonyms of C. affinis, a form which he apparently considers to be merely a subspecies of C. crangon. If Balss is correct, the retention of a distinct subspecific name for the Japanese form seems to have little to recommend it. The characters of C. crangon, if tabulated on Balss's plan, will evidently fall within the raage of variation of the single Japanese ' Rathbun, Proc. U.S. Nat. Miis., XX\'f, p. 42 ( 1902). 2 Pjalss, AbJiamil. matli.-pJiys. Khissc K. Bayer. Akad . Wiss. Mi'tiiclicn, Suppl.-Bd. II, p. 62 (1914). •5- Brashnikow, Meiii. Acad. hup. Sci. Nat. St. Fctcrsbiirg. (8), X.\, p. S4 ( 1907). 1916.] S. Kemp : Noks on Crustacea Decapoda. 381 race that he recognises, the difference between the European and Japanese races consisting solely in the greater variability exhibited by the latter. The Indian specimens do not show any marked variation, but the series is small. And even should their form prove constant, it is useless to speculate on the precise status of the different races until some general consensus of opinion on the Japanese forms has been reached. Crangon crangon appears to be very rare on the Indian coasts ; the only specimens in the Museum are the following ; — -'--^^" Akyab, Arakan coast. F. SloHczka. 5. ,3-52 "ini. The Structure of the Pleopods in Pontophilus. The recognition of the fact that in certain species of Pontophilus there are often marked differences between the sexes in the form of the pleopods, and that the species themselves also differ to a great extent in the development of these appendages, has led me to re-examine the material available in the Museum collection. In the Indian Museum twenty-one species of the genus are represented, a very considerable proportion of those that are known ; but , un- fortunateh^, in the case of thirteen only do we possess examples of both sexes. x-llthough iti the development of the pleopods there is a certain amount of intergradation, it is possible roughly to classify the species according to the development of these appendages into five groups : — Group I. P. norvegicus, M. Sars ( ^ ^ndopod of last four pairs of P oyacilis Smith ' pleopods well developed m both P. trevhostrls. Smith ) '^f '' '""'^^ conspicuous appendix ' interna. P. spinosus, lycach, P. abyssi, Smith, and P. occidentalis, Faxon, represented in the collection by female specimens onl}^ doubtless also belong to this group. Group II. Endopod of last four pairs of pleopods comparatively well deve- loped in male, reduced in female. P. sculpi'us (Bell) ] Appendix interna present in male on all four pairs, but somewhat rudimentary on the last ; in female present on 2nd and 3rd pairs, rudi- mentary on 4th and absent from 5th. P. incisus, sp. nov P. australis, Thomson P. chiltoni, Kemp, known from female specimens only, also in all probability belongs to this group. 382 Records of the Indian Muscnin. [Voi<. XII, Group III. P. lowisi, sp. nov. i Endopod of last four pairs of pleo- P. pUosus, sp. nov. 1 P°^' comparatively well developed P. candidus,sp. nov. ) 'l'. ^^.^^ ^^^^^^^^ "! ^^"^^l^^, ^^PP^."" P Uebs sp nov . ^^^^^"^^ present on all four pairs ■^ '■ ■ I in male, but entirely absent in female. Group IV. Endopod of last four pairs of pleo- pods large and well developed in P. sabsechota, Kemp <| female, quite rudimentar}" in male. Appendix interna absent in both sexes. Group V. r, 1 ■ .- TT -1 j_ i Endopod of last four pairs of P. bisptnosus, Hailstone i . / , ij-u.Lt. J IT' 1 J ? pleopods much reduced m both and westwood. a j- • ^ 1 7-, , . ,• TT -1 .>_ i sexes. Aopendix interna absent '^ ' m both sexes. P. echimilatus (M. Sars), P. vicionensis, Fulton and Grant, P. heiidersoni, Kemp, and P. parvirostris , sp. nov., represented in the Museum collection by examples of one sex only, also in all prob- abilit}^ belong to this group. In Group I the appendix interna is usually tipped^ with a series of small coupling hooks, which are ill-developed or absent in other groups that possess this appendage, In Group V the separation of a distinct segment at the base of the endopod is clearh- marked, whereas in Group I the division is obscurely indicated.^ P. sabsechota, the sole .species comprised in Group IV, is appa- rently an abnormal form, the distinction between the sexes in the size of the endopod being the reverse of that found in any other species which in this respect exhibits sexual differences. The re- maining groups clearly form a morphological series characterised by the progressive reduction of the endopod and b}' the reduction and suppression of the appendix interna. Group I in which the pleopods have retained their full development is clearly the most primitive, while Group \' in which they are more reduced than in any other is the most specialised. It is noteworthy that Group I includes all the deep-water forms in the collection. The facts are not only of interest in the light they throw on the development of the species within the genus; they also, as it appears to me, form a valuable clue to the evolution of the family as a whole, for the other genera can be divided into two sections agreeing, respectively, in the development of their pleopods with ' Cf. \\ ollcback, Hcygens Museums Aarbog, 1008, no. 12, p. 44, icxl- 1916.] S. Kemp : Notes on Crustacea Decapoda. 3S3 Groups I and V of Poniophilus. Ortmann ' in i8go published a genealogical tree of the five genera known to him ; but the evidence afforded by the pleopods leads to results directl}^ at variance with those which he obtained and it will be well therefore to discuss the matter briefly. The two most primitive groups of species in the family are in all probability Aegean and Pontophilus, Group I. The}'' possess — most of them at an^^ rate — a rudimentary exopod on the first legs, the number of branchiae is at least as great as that in an}' other genus and the endopod of the last four pairs of pleopods is well developed and possesses an appendix interna. In Aegean the seconcf leg is larger than in Pontophilus, Group I, agreeing more nearly with that of Group V, and the former genus also possesses a rather larger number of branchiae than the latter. In this last feature it appears to be the more primitive of the two^ but in the curious C-shaped form of its gills it presents a character not known in any other genus of Caridea. Aegean, in my opinion, must be regarded as an offshoot of the original stock from which tlie other genera are descended. The evolution of the remaining genera of Crangonidae can, I think, be traced back to Pontophilus, from which there have been tvi'o main lines of descent, originating respectively in Group I and in Group V. In Group I of Pontophilus, as lias already been noted, the second leg is shorter than in the other groups and it is not difficult to understand how Sabinea, Ou-en, and Paracrangon, Dana, have arisen from it b}' successive steps. In Sabinea the pleopods are as well developed as in any species of Group I and possess a con- spicuous appendix interna ; the second leg has, however, under- gone further reduction ; it is smaller than in any species of Ponto- philus and terminates simph", the chela being altogether sup- pressed. Paracrangon is apparenth' a further development on the same line. The second legs are entirely absent and the endoi^od in the last four pairs of pleopods, though large and well- formed, is without appendix interna. The other line of development has apparently arisen through forms similar to those of Group Y and terminates in four branches, rejjresenting respectiveh' the genera Crangan, ly., Sclerocrangon, Sars, Argis, Kroyer {=Nectocrangon, Brandt) and Prionocrangon, Wood-Mason. In all these genera the endopod of the last four pleopods is greatly reduced, possesses a well marked basal segment, and is devoid of appendix interna. The evidence aft'orded by the development of the second leg is, in this case, rather difficult to interpret. In all the four genera named above it has a proportionately greater length than in any species of Pontophilus', in Prionocrangon, evidently a very highly specialised form, it terminates simply, while in the other three it is chelate. But it must be presumed that all Crangonidae have I Ortmann, Zool. Jalirh., Syst., V, p. 530 (1890). 384 Records of the Indian Museum. [Vol. XII, igi6.] primarily arisen from a form in which this limb was well developed and a priori it was not to be expected that the four genera had passed through a stage in which it was to some extent reduced. It is, however, difficult to see how it could have been other- wise. Crangon and its allied genera might, indeed, have arisen independently from an ancestor of Pontophilus, that is to say from a form differing from Group I of that genus only in the possession of long second legs. In this case the pleopods must have evolved separately in the two instances ; with the result that their identity of structure, as we see it to-day in Crangon and the related genera on the one hand and in Pontophilus, Group V, on the other, is an example of convergence. I am inclined to think that this conclusion is erroneous. The tendency that clearly exists towards the reduction or suppression of the second pair of legs shows that these appendages are un- usually plastic in Crangonidae : the monodactNdous condition of these limbs in Sahinea and Prianocrangon is evidently an instance of convergence and affords no evidence of real affinity. The struc- ture of the pleopods is more likely to yield a trustworthy estimate of relationship. Of the genera F^rco/^, Baker \ and Coralliocrangon, Nobili*, I have seen no examples. In the former, according to a sketch kindly sent me by Mr. Baker, the endopod of the last four pleo- pods is comparatively large, but without appendix interna. The genus has perhaps arisen separately from forms similar to those in Group III of Pontophilus ; it differs from all species of the latter in the monodactylous character of the second legs. Owing to lack of information regarding the pleopods ^ it is impossible to make an}^ suggestion regarding the relationships of Coralliocrangon. This is particularly unfortunate, for the persistence in the genus of the linea thalassinica points to its being a survival of some very primi- tive form. 1 Baker, Trans. Rov. Soc. S. Australia, XXVIII, p. 158 (i904». 2 Nobili, Ann. Set'. Nat. Zool. Paris, (g), IV, p. 82 ( 1006). EXPLANATION OF PLATE VIII. Fig. I. — Pontophiliis incisus, sp. nov, 2. — Pontophilus lowisi, sp. nov. 3. — Pontophihis candidus, sp. nov. 4. — Pontophilus pilosus, sp. nov. 5. — Pontophilus plebs, sp. nov. 6. — Pontophilus parvirostris, sp. nov. Rec. Ind. Mus..Vol.Xn. 1916. Plate VIII 2. 4. A-CChciwdhary, dfil Bemrose.CoMo. Derby NEW INDIAN SPECIES OF PONTOPHILUS. XXI. NOTES ON CRUSTACEA D E C A P O D A IN THE INDIAN MUSEUM. VII. Further Notes on Hippolytidae. By vStanley Kemp, B.A., Superintendent, Zoological Survey of India. (Plate XXXVI). Although onl}' two years have elapsed since my previous paper on the Indian Hippolytidae was published, a number of interest ing forms have come to light, obtained partly during the recent cruises of the 'Investigator' by Capt. R. B. Seymour Sewell, I. M.S., partly by Dr. Annandale in Japan, and partly by myself during a short visit to Port Blair in the Andamans. The Hippolytid fauna of Port Blair is one of great richness. During three weeks' collecting, fully half the known Indian species of the family were met with, enabling me to obtain notes on the natural colouration of several forms hitherto unknown in this respect. In addition, three forms were found that had not pre- viously been recognised, one representing a new generic type. Of these, Thor discosomatis is of particular interest owing to the fact that it lives commensally with a large anemone of the genus Discosoma, and is most peculiar in its colouration ; the species of Phycocaris, gen. nov. , is extremely grotesque in appearance and closely mimics the weed among which it lives. Borradaile, in a recent paper,' has briefly described a genus and three new species of Hippolytidae from the Maldives, the Seychelles and other localities. If my identification is correct, two of these, Thor maldivcnsis and Lysmatella prima (the latter the type of the new genus), occur in the Andamans; but I am inclined to think that Lysmatella should at most be distinguished only subgenerically from the closely allied Hippolysmata. Ex- Jiippolysniata , recently proposed by Stebbing"^ to include Hippolys- mata ensirostris and a nearly related form from S. Africa, does not appear to differ sufficiently to warrant either generic or subgeneric separation. Genus Saron, Thallwitz. Saron marmoratus (Olivier). 1 914. Saron viavnioratiis, Kemp, Rec. hid. Mus., X, p. 84. A number of specimens of this well-known species were ob- tained at Port Blair ; the majority were found under stones left ' Borradaile, Ann. Mag. Nat. Hist., (8), XV, pp. 206, 208 (1915). . '^ Stebbing, Ann. S. African Mus., XV, p. 94 (1915)- 386 Records 0/ the Indian Museum. [\'OL. XII, bare at low water, but one individual was dredged at a depth of two fathoms. There are tufts of setae on the carapace and abdomen of all the specimens; the males are small and do not possess the enlarged third maxillipedes and first peraeopods characteristic of well-grown examples of their sex. On close inspection the colouration of living specimens is very wonderful, resembling that of a rich Turke}^ carpet. At a casual glance, however, the animal is dull in tone and it is clear that the vivid tints blend and cause it to harmonise with its sur- roundings, just in the same way that the splashes of bright colour on gun-mountings are effective in rendering them inconspicuous. On the carapace and abdomen are numerous large ocellar spots of an irregular shape ; in the centre these spots are bufii, dotted with red and circumscribed with white and reddish orange. Between the spots are patches, irregularly lobulate in form, but symmetrical on either side of the animal. They are of a deep red- dish brown colour with numerous large bright blue spots. Each patch is sharply defined, its sinuous margin being outlined with black and pale grey. At the antero-lateral angle of the carapace there is a dull red spot. The rostrum, antennules and antennal scales are pale bull', barred with dark brown, the brown bearing numerous white flecks. The anterior two pairs of legs are reddish at the base ; their distal segments and all segments of the last three pairs are pale yellowish green broadly barred with black. The tail-fan is obscurely mottled with brown and buflf. The largest specimen, an ovigerous female, is only 36 mm. in total length. "fo° Po'"'^ Blair, Andamans. S. Kemp. Kle\cn. Genus Spirontocaris, Bate. Spirontocaris pandaloidcs (Stimpson). 1907. Spiroiifocan's paudaloides, de Man, Trniis. Li)!)!. Soc, Zoo!..- (2), IX, p. 418, pi. xxxii, figs. 47, 48. A number of examples of this species were obtained by Dr Annandale during his recent visit to Japan from Mr. Kuma Aoki. The teeth on the rostrum vary from 8 to 10 on the upper border and from 10 to 13 on the lower. -\xr Misaki, japan. Kuma Aoki. Fourteen, 46-49 mm. Spirontocaris rectirostris (Stimpson). 1907. Spirontocaris rectirostris, de Man, Trn,:'- Li)in. Soc, Zoo/.. (2), IX, p. 411, pi. xx.xii, figs. 31-34. Two fine specimens in Dr. Annandale's Japanese collection (presented by Dr. S. Yoshida) agree very closely with de Man's description of the male of this species. Both individuals have only 5 teeth on the upper border of the rostrum; on the lower iQi6. J ,S. Kemp : Notes on Crustacea Decapoda. 387 border there are 2 in one specimen and 3 in the other. The telson in one case bears four pairs of dorsal spinules, in the other five. De Man has drawn attention to the great development of the third maxilHpedes and first peraeopods in the male. In the two specimens obtained by Dr. Annandale this character is well shown, the proportions of the limbs agreeing precisel}^ with de Man's des- cription. The enlargement of these appendages in the adult male is a feature of considerable interest, for though apparently rare in the genus Spirontocans, an almost precisely similar phenomenon is met with in the genera Alope and Saron. "'Yjf- Tanabe, Kii prov., Japan. S. Voshida. Two, 34, 36 mm. The third maxilHpedes in the larger specimen are 30 mm. in length ; in the smaller they are 26 mm. Genus Thor, Kingsley. The definition of this genus requires modification in order to include T. maldivensis, Borradaile, in which supraorbital spines are found on the carapace. In addition to the greater number of segments in the carpus of the second peraeopods and the presence of a movable plate at the distal end of the antennular peduncle — characters by which the genus is readily distinguished from Hippo- lyte — the outer antennular fiagellum, in Thor, is greatly swollen in both sexes. An interesting species, hitherto undescribed, was obtained at Port Blair ; it lives commensally with giant sea-anemones of the genus Discosoina and is very peculiar in its pigmentation. The three known species of Thor, all of which have been found in the Andamans, may be distinguished as follows : — I. Rostrum with two or more dorsal teeth; supraorbital spines absent. A. Apex of rostrum bifid ; lateral process of antennule without a tooth at its proximal end ... ... T. paschdlis (HeWev). B. Apex of rostrum simpl)- pointed ; lateral process of antennule with a small upstanding- tooth at its prox- imal end ... ... ... T. cfiscosoDiiifis, sp.nov. II. Rostriun with only a single dorsal tooth; supraorbital spines present ... ... T. niatdiveiisis, Borra- daile. Thor paschalis (Heller). 1914. Tlwr pasclialis, Kemp, Rec. hid. Mas., X, p. 94, pi. i, fio-s. 6-10. Additional specimens are from Singapore and from Port Blair in the Andamans, The species was found on several occasions in the latter locality, living among weeds at depths of from 2 to 5 fathoms in .^e neighbourhood of Ross I. The specimens are smaller than the majority of those obtained in the Gulf of Manaar ; the largest is only 8 mm. in length and ovigerous females some- times do not exceed 6-5 mm. The single individual from Singa- pore, a male, was obtained at low water under a block of coral. 388 Records of the Indian Miiscitui. [Vol. XII, Port Blair, Andamans. Tanah Merah Besar, Singapore I. S. Kemp. N. .\nnandale. Ten. One. Thor discosomatis, sp. nov. (Plate xxxvi, fig. i). Thor discosomatis is a very close ally of T. paschalis and agrees with that species in the great majority of its structural features. It differs, however, in the following points: — Fig. I. — 'f/ior Antennule. Antennal scale. First peraeopod. Second peraeopod (^iscosoiiiat/s. sp. no\'. e. Third peraeopod. /. Second pleopod of male. g. Telson. /;. Apex of telson. The rostrum is a little shorter ; at its apex it is sharply point- ed, not bifid, and on its upper margin it bears only two or three teeth. These teeth are larger and all of th.-m are situated on the rostrum in front of the hinder limit of the orbit. The basal seg- ment of the antennular peduncle (text-fig. la) bears a spine on its infero-internal aspect, as in T. paschalis; but the lateral pro- cess, though variable in length, is usually longer than in that species, often reaching the end of the third segment. The process bears, near the proximal end of its outer margin, a sharp upstand- ing tooth of which no trace exists in the allied species. 1916.] S, Kemp : Notes on Crustacea Decapoda. 389 The peraeopods closely resemble those of T. paschalis. The car- pus of the second pair (text-fig. id) is composed of six sub-segments the proportional lengths of which are much the same as in T. pas- chalis, except that the third is comparatively a little shorter. There is practically no difference between males and females in the length of the third pair of legs (text-fig. le). On the lower border of the merus of the third and fourth pairs there is a small subterminal spine. This spine is present on all the last three pairs in T. paschalis} whereas in T. discosomatis it is absent from the last pair. On the telson (text-fig. ig) as in T. paschalis there are three or four pairs of dorso-lateral spinules. At the apex, however, there are four pairs of spines, the outermost the shortest, the second the longest and the two inner pairs sub-equal (text-fig. ih). In T. paschalis there are only three pairs of terminal spines. In the shape of the antennal scale (text-fig. 16) and in all other features, T. discosomatis seems to bear the closest resem- blance to T. paschalis. The largest specimen obtained, an ovigerous female, is 13 mm. in length. The colouration of living specimens was ver}'- remarkable, the animal being of a deep reddish brown tint, semitraasparent, with very large spots and patches of pale greenish yellow. On the carapace are two such spots, round and confluent in the mid- dorsal line ; there is one on either side of the second abdominal somite, a broad transverse band on the fourth somite with a small spot on each side below it, a ventral transverse bar on the fifth somite and a patch, forming a complete ring, on the sixth somite. Each of these spots or patches is ver}^ pale green in the centre, with a broad margin of bright yellow, the whole being narrowly circumscribed by blue. The central portions are traversed by streaks of yellow extending inwards from the margin. The apex of the telson is greenish yellow and there is a circumscribed spot in the middle of each uropod. On the upper side of the eyestalk there is a greenish yellow patch ; all the other appendages are reddish brown. The specimens of Thor discosomatis were found along with a Palaemonid in the immediate vicinity of large anemones of the genus Discosoma. Two very small individuals were obtained in the dredge, but it is probable that on this occasion the net was drawn over an anemone in the course of its passage along the bottom. The Palaemonid has been described by Nobili under the name Ancylocaris aherrans,^ and of this species Miss Rathbun's Pericli- menes hermitensis^ is apparently a synonym. Coutiere,* who ^ These spines are omitted in the figure given in pi. i, fig. 6, op. cit., 1914. ^ Nobili, Bull. sci. France Belgiqiie, XL, p. 52, pi. iv, figs. 9-96 (igof)). 3 Rathbun, Proc. Zool. Soc. Loudon, 1914, p. 655, pi. i, figs. 1-3. + Couticre, Bull. Mns. d'Hisf. iiat., Paris. 1\', p. 19S (1S98). 390 Records of the Indian Museum. [Vol. XII, refers to the same form as a species of Bithynis, has given the following account of its habits. — " Un Palemonide du genre Bithv- nis Dana merite une mention speciale par son habitat et sa colora- tion. II est absolument transparent, mais se signale par quelques anneaux d'un violet pale sur les appendices et 1' abdomen, et sur- tout par des taches d'un blanc nacre eclatant, occupant la region stomacale tout entiere, le coude de 1' abdomen, I'extremite des rames caudales et les epimeres du deuxieme segment. Ce magni- fique Crustace se tient obstinement dans la zone de protection que circonscrit une grande Actinic assez commune dans les flaques profondes qui separent les Madrepores. Btale sur le sable, le disque oral de 1' Actinic de couleur blanchatre, arme d'un tres grand nombre de courts tentacules urticants, atteint souvent o m. 30 de diametre. Bithynis se tient dans ce cercle, nageant a peu de dis- tance au-dessus, souvent par couples, et se laisse assez aisement capturer a I'aide d'uiie eprouvette pleine d'eau que Ton descend doucement sur ranimal." The anemone at Port Blair was one with greenish tentacles, not whitish as in Coutiere's description. It was not uncommon at low water on the foreshore at " Aberdeen" and was sometimes left high and dry by the tide. On anemones from which the water had completely retreated we failed to find any shrimps, even though the whole specimen was dug up and most carefully ex- amined. On the other hand the shrimps were seldom absent from anemones living in a few inches of water, and were easily caught in a tube full of water as described by Coutiere. The A ncylocaris ' was found swimming and crawling on the column of the anemone beneath the fringe of tentacles and wandering occasionally on to the disc. Thor discosomatis had similar habits, but seemed to wander further afield and rarely ventured among the tentacles. The curious feature of the shrimps is that in both species the pigmentation takes the form of very large spots almost pure white in colour. This, too, is a characteristic of certain fish, Amphiprion percula (Lacep.) and Tetradrachmum trimaculatum (Riipp.),"^ which also appear to live commensally with the Discosonia ; the latter was found beneath the fringe of tentacles and was black with a broad transverse band of white at the back of the head, extending down- wards to the eye, and a large white spot below the dorsal fin ; the former, which was commonly found swimming among the ten- tacles, was bright orange with three broad bands of white tinged with green and narrowly margined with black. The presence of white patches in all four commensal species is a most curious ' Coutiere, in this brief description, has scarcelv done justice to the marvel- lous colouration oi Aiicylocai'is aberrans \ the large white patches are frequent 1}- circumscribed by red or orange pigment and on the tail-fan are eye-spots with reddish centres. A complete account of the colouration of this Palaemonid would be out of place in the present paper, but it may be mentioned that the pigmenta- tion varies somewhat in the two sexes and alters considerably with age. The colouration of Thor (fiscosoiiiafis, on the other hand, is apparimtls' constant throughout life. ^ 1 .im indebted to Dr. B. I., (haudhuii lor llicse deterniin.-ition--. 1916.] S. Kemp : Notes on Crustacea Decapoda. 391 feature and one of which it is impossible to offer an explana- tion. S. Kemp. Fourteen. The types bear the number 9261/10. Thor maldivensis, Borradaile, igi5. Tlwr jiialdivcnsis. Borraihiilc, Ann. Mag. Xat. Hist.. (8), X\', p. 2()8. A single ovigerous female, about 9 mm. in length, doubtless belongs to this species. It differs, however, from Borradaile's brief description in possessing six distinct segments in the carpus of the second peraeopods. The presence of strong supraorbital spines and the very short rostrum, armed with only a single dor- sal tooth are characters which readily distinguish it from the two preceding species. According to Borradaile the first leg is enlarged in adult males. ■'I,';' Port Blair, Andainans. S. Kemp. One. The specimen was found at low water on the coral reef in North Bay and was, when living, rather conspicuously mottled. Thor maldivensis was described from Minikoi, the Maldives and Salomon Atoh. Genus Hippolyte, Leach. Hippolyte ventricosus, Milne-Edwards. .1014. llippolvtc vci/fricosi/s. Kemp, Rec. I ud . M/ts., X, p. ()6, p|. ii, fi,?s. 1-3. This species is not very abundant in Port Blair harbour. The majority of the specimens obtained were taken at Corbyn's Cove North, not far from the entrance to the harbour, living in a fucoid weed washed by the waves. All the individuals taken in this situation were of a dull olive-brown colour closely resembling that of the sea- weed. The collection includes many ovigerous females, an unusually large specimen being 21 mm. in length. 'fo^ Port Blair, Andamans. S. Kemp. Many. Genus Phycocaris, nov. Carapace with supraorbital and antennal spines; antero- lateral (pterygostomian) spine absent. Lateral process of anten- nular peduncle spiniform ; upper flagellum uniramous. Mandible with incisor-process, but without palp. Third maxillipede with exopod. Neither epipods nor arthrobranchs at base of first four peraeopods. Carpus of second peraeopods composed of two seg- ments. Endopods of second to fifth pleopods very large in female, small and slender in male. Type and onh' species, P/iycocaris sinmlans, sp. nov. 392 Records of the Indian Museum. [Vol XII, This genus is formed for the reception of a small and peculiar Hippolytid of the most grotesque appearance, that lives on weeds in the vicinity of Port Blair. On its appendages, including the eyestalks, are long straggling hairs and these, in conjunction with its colour and the unusual attitude it adopts, combine to give it a most extraordinarily close resemblance to small tufts of algae. In most of the characters mentioned above the genus agrees with Caiman's Trachycaris,^ though in outward appearance there is the widest possible difference between them. The type and only known species of Tr achy car is''- is that described by vSpence Bate from the West Indies under the name Platyhema rugoswn. It agrees with Phycocaris in having only two segments in the carpus of the second peraeopods and in the great size of the endopods of the second to fifth pairs of pleopods. The latter character, though given without qualification in Caiman's diagnosis, is probably found only in females. Phycocaris differs from Trachycaris in the absence of the antero- lateral spine of the carapace and in the presence of an incisor-pro- cess on the mandible.^ The latter feature is of considerable importance and indicates that the genus is in reality allied to Thor and Hippolyte rather than to Trachvcaris and other genera of the Latreutid section of the family. From Thar , Hippolvte and the peculiar N. Atlantic genus Cryptocheles, it is easily distinguished by the number of segments in the second legs. Phycocaris simulans, sp. nov. (Plate xxxvi, fig. 2). The carapace is arched above and is produced anteriorly to a short and simple rostrum that reaches only a little beyond the end of the basal antennular segment. On the frontal margin above the eye there is, on either side, a short and stout supraorbital spine. The antero- lateral (pterygostomian) spine is absent, but there is a small spine at the base of the antenna; the antero- inferior angle is rounded. The carapace is not carinate in the middle line and bears a few long scattered hairs. The eyes are comparatively long and slender. In dorsal view the cornea is not broader than the stalk and is about half its length. There is no ocellus ; but at the junction of the cornea and stalk there is a circlet of long hairs, a remarkable feature not known in any other Hippolytid. The basal segment of the antennular peduncle (text fig. 2a) is fully as long as the two following combined; its lateral process is I Caiman, A/in. Mag. Nat. Hist., (7), XVII, p. 33 {igob). '^ Platybema pristis, Nobili, \ Ann. Miis. civ. Genova, (2). XX, p. 233 (1S09) should doubtless be referred lo the grenus Lntreittes. 'i The statement that the mandible in Tracliycaris is wiliiout incisor-process i^ i>i\cn by Caiman on the authority ot" Spence Bate. I have examined a specimen J nigosiis and am able to confirm the accuracy of the observation. 1916.] S. Kemp : Notes on Crusiacea Decapod a. 393 slender, incurved and spine-like, extending a little beyond the end of the segment and bearing a few hairs externally. The second and third segments are nearly equal in length, each bearing near its distal end one or two very long plumose setae. The outer flagellum is longer and stouter in the male than in the female. In the former sex the thickened portion is composed of some seven segments and is longer than the peduncle ; in the latter it is shorter than the peduncle and consists only of five more slender segments. Autennule. Autenual scale. Mandible. Third maxillipede, the distal segment seen obliquely. Distal segment of third maxilli- pede. First peraeopod. Phvcocarix xi nitila its. gen. cl sp. nov. g. Chela of first peraeopod. h. Second peraeopod. i. Third peraeopod. /. Dactylus of third peraeopod. k. Second pleopod of female. /. Telson. ;/. Apex of telson. The inner flagellum is short and is usually carried reflected back- wards. The antennal scale (text- fig. 26), which reaches a little beyond the antennular peduncle, is broadest near the base and is less than twice as long as wide ; the outer margin is convex, terminating in a spine that reaches as far forwards as the apex of the lamella. The peduncular segments bear long setae similar to those on the antennule. 394 Records of the hidian Museum. [Vol. XII^ The mandible resembles that found in the genus Thor ; the incisor-process is well developed and is furnished with about seven teeth at the apex. The palp is entirely absent and the molar pro- cess is cleft and furnished with slender spines, many of which are serrate. The second maxilla is normall}' developed ; the distal endite of the endopod is divided into two parts of equal breadth. The first and second maxillipedes possess epipods, that of the former being emarginate distally, while that of the latter is deeply bilobed. The ultimate segment of the endopod of the second maxillipede is placed terminally at the end of that which precedes it and is not applied as a strip along the outer margin of the latter as in the great majority of the Caridea. The third maxillipede (text-fig. 2d) does not possess an epipod ; the exopod is small but foliaceous, reaching about to the middle of the antepenultimate segment. The ultimate segment (text-fig. 2e) is less than twice the length of the penultimate and is not three times as long as broad ; in addition to numerous hairs it bears a series of nine or ten sharp spinules in its distal half. The first peraeopods (text-fig. 2/) are stout, but very short ; the ischium and merus and carpus are sub-equal, a little shorter than the chela. The segments bear long setae but are otherwise unarmed. The chela (text-fig. 2g). is rather more than twice as long as broad and the fmgers are distinctly longer than the palm. On the interna] surface of the chela the fingers are deepl}' hollowed or spooned near the cutting margin, while externalh^ each forms a thin blade with a saw-like edge, the two meeting throughout their length when the claw is closed. At the extreme tip each finger is provided with three large teeth. The second peraeopods (text-fig. 2h) are much longer, reach- ing nearh^ to the tip of the antennal scale. The carpus is almost as long as the ischium and merus combined and consists of two segments, the second a little shorter than the first and about twice as long as broad. The chela is almost two-thirds the length of the carpus and nearly two and a half times as long as wide, the fingers being about one-third shorter than the palm. When the claw is closed the fingers meet only at the tips where they cross each other. The last three pairs of peraeopods (text-fig. 2i) are similar and show no sexual differences. The carpus is scarcely shorter than the merus and is a trifle longer than the propodus. The propodus is armed beneath with five or six spines, two pairs towards the distal end and one or two others, which are smaller, near the mid- dle. When the dactylus is folded inwards it lies between the two spines constituting the distal pair and thus forms a poorl}^ de- veloped grasping organ. The dactylus (text-fig. 2/) is short, spines included about two-fifths the length of the propodus : on its in- ferior edge it bears a series of "seven or eight spinules which in- crease in size distally, the two terminal ones being large spines. All the legs bear very long plumose setae, especially conspicuous on the ischium, merus and carpus. 1916.] S. Kemp : Notes on Crustacea Decapoda. 395 The abdominal somites are not carinate dorsally. The third is very strongly humped and the sixth, which is but little longer than the fifth, is produced to a rounded prominence in the middle of its posterior margin. The endopod of the last four pairs of pleopods bears an appendix interna and is enormously expanded in the female (text-fig. 2k) ; in the male it is not broader than the exopod. The margins of l^oth rami bear long setae. The telson (text-fig. 2/) is nearly twice the length of the sixth somite and is feebh^ sulcate above. It bears two or three pairs of small dorso-lateral spines and terminates in a broad, almost trun- cate apex (text-fig. 2in) armed with three pairs of spines, the innermost the longest, about equal to the breadth of the apex, and the outermost m.uch the shortest. Between the innermost pair of spines are two minute splnules, while a similar spinule occurs on either side between the bases of these spines and those of the intermediate pair. The outer uropods do not reach the apex of the telson ; they are shorter than those of the inner pairs and are rather more than two and a half times as long as wide. The long setae that have been described above as plumose differ considerably from those to which this term is generally ap- plied, for the plumes have not the form of ver^^ fine microscopic hairs, but are comparatively short and blunt processes from the main axis of the seta. The largest specimen obtained, an egg-bearing female, is barely 9 mm. in total length; other ovigerous individuals do not exceed 7 mm. This curious little species was found at Port Blair near Ross I., living among weeds in water from 2 to 4 fathoms in depth. We found it impossible to obtain specimens at all freely by the usual methods, but if the contents of the net were immediately transferred to a bucket of sea-water, individuals were sometimes found swimming at the surface and alighting on floating fragments of weed. The illustration on Plate xxxvi, which is based on sketches made from living specimens, will give an idea of the peculiar atti- tude that the species adopts. The abdomen is strongly flexed near its junction with the cephalothorax, so much so that the third segment as a rule almost touches the carapace, and the antennules are bent upwards and backwards. In this attitude, and with the help of the long plumose setae that the species possesses,' Phyco- caris bears the most extraordinarily close resemblance to small tufts of algae that are plentiful on the weeds : it was only after considerable experience that we were able to distinguish the one from the other. The resemblance, which is undoubtedly protec- tive, is further enhanced by the colour. The tufts of algae vary in shade and are sometimes dull olive-yellow and sometimes almost black. Two colour varieties of the prawn, corresponding ^ These setae are very easily broken off in preserved specimens and are in lite more numerous and longer than is shown in the figure. 3Q6 Records of the Indian Museum. [Vol. XII, exactly with these tints, were obtained and a few specimens of a bright red tone were also caught on occasions in which much red alga was Vjrought up in the net. ''"VJ"" Port Blair, Andamans. S. Kemp. Twenty-four. The type specimens bear the numbers 9255-6/10 in the Indian Museum register. Genus Latreutes, Stimpson. Latreutes pygmaeus, Nobili. 1914. Latreutes pygmaeus, Kemp, Rt'c Iini. Miis.. X, ]). gy, pi. ii, fi^s. 7, 8 ; pi. iii, figs. 1-7. The species was very common in the vicinity of Ross I., living among weeds. Most of the females were ovigerous. s.^L&. Port Blair, Andamans. S. Kemp. Man\-. Latreutes planirostris (de Haan). 1907. Latreutes planirostris, dc Man. Trans. Liuu. Soc, ZooL. (2). IX, p. 421. 1914. Latreutes planirostris, Balss, Abliafidl. math.-plivs. Klasse K. Bayer. Akad. Wiss., Suppl, Bd. II, abh. 10, p. 46. This species is represented in the Museum collection by two female specimens, in both of which, as in those examined by Miss Rathbun,' the median spine in the posterior third of the carapace, figured by de Haan, is obsolete. Miss Rathbun cites L. mucronaUis as a synonym of L. plani- rostris, but this view is not held by Balss. L. planirostris is a larger species, with even more perfectly orbicular rostrum than in any examples of L. mucronatus that I have seen; the carapace, moreover, is carinate in the mid-dorsal line almost up to the pos- terior margin. -f^ Sagami Bay, Japan. Munich Mus. One, 25 mm. "fo" Misaki, Japan. Kuma Aoki. One, 28 mm. Latreutes mucronatus (Stimpson). 1914. Latreutes viucrouatus, Kemp, Rec. Ind. Mus., X, p. lui, pi. iii, figs. 8-15 ; pi. iv, figs. I, 2. 1914. Latreutes mucronatus. Balss, Abliandl. tnatli.-pliys. Klasse A. Bayer. Akad. Wiss., Suppl. Bd. II, abh. lu, p. 47, fig. 27. The additional specimens agree with those recorded from Kila- karai and Pamban in vS. India, but are rather smaller ; the largest is only I0"5 mm. long and one of the five ovigerous females is less than 8 mm. in length. The remarkable sexual differences noted in the case of the S. Indian specimens are clearly shown in the Andaman series, the females have the carapace more strongly arched and the rostrum more orbicular than in the males. Out of a total of thirty individuals only five, all males, possess more than a single tooth on the carapace behind the orbit ; in three specimens Rathbun, Proc. U.S. Nat. Mus., XX\'I, p. 46 (i9;)2). iQi6.] S. Kemp : Notes on Crustacea Decapoda. 397 there are 2 teeth and in two specimens 3 teeth in this position. In no case is there a tooth in the posterior third of the carapace as in de Haan's figure of L. planirostris. The teeth on the upper edge of the rostrum in the male may be as many as 10. Living specimens were as a rule inconspicuously mottled ; two examples were, however, found in which the carapace and the greater part of the abdomen were of a uniform rich red-brown, the tail-fan and the posterior half of the last abdominal somite being pure white. Balss, who has recently recorded this species {I.e. supra) from Sagami Bay in Japan, from the Gulf of Siam and from Chemulpo in Korea, notes that the specimens recorded by Doflein in IQ02 as L. inucronatus are in reality examples of L. planirostris, de Haan. ^Y§~ Port Blair, Andainans, 2-6 fms. S. Kemp. Thirty. Most of the specimens were obtained among weeds in the channel off Ross I. ; a few were found in Brigade Creek. Latreutes porcinus, sp. nov. (Plate xxxvi, fig. 3). In general form there is very little difference between the sexes; in both the carapace is sharply carinate dorsally, the carina being very high and abruptly declivous in its anterior third. The carina is armed with rather irregular procurved teeth, 6 to 12 in number (usually 9 to 11 in large specimens). The series begins behind the middle point of the carapace and the foremost 3 or 4 are usually in advance of the orbit, though separated, in the ma- jority of the specimens, by an unarmed interval from the teeth on the rostrum proper. The antennal spine is present and there are 7 or 8 spinules on the antero-lateral margin. The rostrum resembles that found in female L. mucronatus , being semiorbicular and rounded anteriorly or broadly lanceolate and more or less pointed at the apex. The teeth are on the whole less numerous than in the allied species; the dorsal series consists of from 4 to 8 and the ventral of from 3 to 8 ; in most specimens there are from 5 to 7 on each margin. In two out of the fifteen specimens examined there are three minute teeth in the interval between the upper rostral teeth and the series on the carapace. The antennule (text-fig. 3a) is more slender than in L. mucro- natus ; the antennal scale (text-fig. 36) is closely similar in form. The second peraeopods (text-fig. ^e) are a trifle more slender and of the three segments of which the carpus is composed the second is proportionately longer, exceeding the length of the first and third combined. The last three peraeopods are similar to those of L. mucronatus , but the terminal spine of the dactylus is usually more slender than the next of the series. In a few individuals two spines are to be found at the distal end of the lower margin of the merus of the third pair (text-fig. 3/); in most cases, however, as in L. mucronatus , single spines occur in this position. 398 Records of the Indian Museum. [Vol. XII, The third abdominal somite is distinctly carinate in its pos- terior half. The telson and uropods (text-figs. 3g, h) are not greatly dissimilar from those of L. mucronatus. The largest specimen., an ovigerous female, is about I5'5 mm. in length. In general appearance this species bears some resemblance to Trachycaris rugosus, a West Indian form with which it has, of course, no real affinity. From all species of Latreutes hitherto Fig. 3. — Patreiifcx poiciiius, sp. nov. a. Antennule. e. Second peraeopod. b. Antennal scale. /. Third peraeopod. c. Third maxillipede. i,'. Telson. d. First peraeopod. /;. Apex of telson. known it is at once distinguished by the great number of teeth on the carapace. Living specimens were variously banded and mottled, some- times with pure white on a ground colour of reddish brown ; one individual was pale pink throughout. °'7;" Port Rlair, Andamans. S. Kemp. Fifteen. The specimens were all obtained oft" the jett}' on Ross I., liv- ing among weed in company with Lalreutes pygmaeus, L. mucro- natus and Tozeuma armatiim. The types bear the number 9269/10. 1916.] S. Kemp : Notes on Crustacea Dec a pod a. 399 Latreutes anoplonyx, Kemp. 1914. Latreutes anoplonyx, Kemp, Rec. Ind. Miis.. X, p. 11)4, pi. iv, figs- 3-5- Numerous additional specimens of this species have recently been obtained by the ' Investigator ' off the Burma coast ; they agree closely with the type. The rostrum is rather unusually con- stant in form, being always narrowly triangular in shape and extending, in all except extremely young specimens, well beyond the apex of the antennal scale. The dorsal margin is, however, straight in some examples, markedly concave in others. The number of teeth is variable ; there are from 7 to 15 on the upper margin and from 6 to 11 on the lower. As was pointed out in the original description, L. anoplonyx differs from all other Indian species of the genus in that the dactyli of the last three legs are unarmed except for a few microscopic spinules. The largest individual, an ovigerous female, is only 28 mm. in length, and is thus considerably smaller than the type. 335 Bombay. H. P. le Mesurier. One. ^'^W '^ Burma coast, 7-8-^- fms, ' Investio-ator.' Many. The only other known example was found at Bombay. When describing this species I remarked that its nearest ally appeared to be Ortmann's L. laminirostris. It is perhaps at least as nearly related to L. imidentatus , Bate,^ imperfectly described from a single specimen only 5-5 mm. in length obtained off Sara- boangan in the Philippine Is. Very young examples of L. ano- plonyx do not differ greatly from Bate's figure; but in the descrip- tion it is stated that the last three legs agree with those of L. planus in which, according to the figure, the dactylus is biunguiculate. Neither L. planus nor L. imidentatus have been recognised since they were first described and it seems likely that their identifica- tion will remain uncertain until the Hippolytid fauna of the Philip- pine Is. is investigated in detail ; it is not even certain that they are correctly referred to the genus Latreutes. Genus Tozeuma, Stimpson. Tozeuma armatum, Paulson. 1914. Tozeii»ia arniatKm, Kemp, Rec. Ind. Mus., X, p. 106. 1914. Aiigo.sia. armatn, Balss, Ahhandl. math.-phys. Klasse K. Baycv. Akad. Wiss., Suppl. Bd. II, abh. 10, p. 48. The additional specimens of this species, though a number of them are ovigerous females, are much smaller than those previ- ously recorded from the Indian coast, a feature correlated perhaps with the shallower water in which they were obtained. The lar- gest individual is only 43 mm. in length. The number of teeth on the lower margin of the rostrum is variable and in one example is as high as 39. This specimen, obtained by Mr. Hornell in S. India, also possesses the additional i Bate, Rep. Cliallenger Macrura, p. 5S4, pi. Ixxix, Hg. 5. 400 Records of the Indian Museum. I Vol XII, spine near the postero-inferior angle of the fifth abdominal somite, noticed in one of the examples previously recorded. In the latter, however, the number of rostral teeth is not abnormal. A remarkable larval Carid found by the 'Investigator' in the Mergui Archipelago almost certainly belongs to this species (text- fig. 4) Although the rostral apex is broken the specimen is no less than 31 mm. in length. On the carapace are two large supra- orbital spines (which are absent in the adult) and the spines on the lower edge of the rostrum are represented merely by fine spinules. The legs are imperfectly formed, the first being chelate and the second simple with unsegmented carpus; attached to the first three pairs are long exopods. The hook-like projection on the dorsum of the third abdominal somite, a characteristic feature of adults of this species of Tozeuma, is represented by an enor- mously long, flattened, outstanding process, the tip of which is sickle-shaped and curved forwards. The sixth abdominal somite is proportionately much longer than in adults, while the telson Fi,^'. 4. — Tozeiima amnatuDi, Paulson. Late larval stage. exceeds the tips of the uropods and is deeply bifurcate at its apex. Apart from its structure this post-larval specimen is remarkable for its great size. It is probable that (as is known to be the case with some other Caridea) there is an actual shrinkage in length at the final moult of the larval metamorphosis ; other specimens in the collection, possessing all the adult characters, are i or 2 mm. shorter than the post-larval individual. The colouration of living individuals, as observed in the Andamans, is peculiar. The specimens were deeply mottled with closely aggregated dark red chromatophores, slightly paler dor- sally and especially dark on the lower portion of the rostrum which was fringed with bright red hairs. On the second and fifth ab- dominal pleura there were large eye-spots, each being deep blue in the centre, surrounded with concentric rings of black, pale yellow and red, in the order named. Just beyond its middle each of the inner uropods bore half a similar eye-spot, the two uropods, when juxtaposed, presenting a single perfect spot when seen from below. In dorsal view the spot is partially covered by the telson which is iqi6.] S. Kemp : Notes on Crustacea Decapoda. 401 not marked correspondingly. The inferior portions of the sixth somite were tinged with blue and there were pale pink chroraato- phores on the hook-like process on the third somite. The outer maxillipede was dark red, the first legs tinged with red and the remainder transparent. Not infrequently specimens of a uniform bright green colour were met with. In these the rostral setae were also bright red, but the eye-spots were merel}' of a darker green surrounded by narrow bands of black and white. In the weed among which it is found T. armatum is very inconspicuous, extending its body almost perfectly straight and holding tightly to the stem. -^%- Mandapam, Ramnad Dist., J. Hornell. One. S. India, 3 fms. -^- Port Blair, Andamans, S. Kemp. Nineteen. 2-5 fins. 5|-g- Burma coast, 8 fms. ' Investigator.' One, larval. Balss {loc. cit. supra) has recently recorded this species from Japan, thereby making a considerable increase in its known geo- graphical range. Genus Gelastocaris, Kemp. Gelastocaris paronac (Nobili). 1914. Gelastocaris paro)iae, Kemp, Rec. Ind. M/is.. X, p. 107, pi. v, figs. I-I I. An additional specimen of this curious species was obtained at Port Blair. It was dredged in 5 fathoms of water along with the sponge Petrosia testudinaria, Lamarck.' When alive the indivi- dual was remarkable for its strangely depressed form, the carapace and abdomen being so much flattened that it resembled an Isopod of the genus Idotea. In colour the specimen was pale pink through- out with a speckling of darker pink chromatophores on the anten- nal scale and tail-fan and at the sides of the carapace and abdo- men. The Petrosia was of a similar pink shade and the coloura- tion is doubtless protective. The specimen is a male, about 10 mm. in length, and, except for the thickened outer antennular flagellum, differs little from the two females previously recorded; in lateral view, however, the carapace is less strongly arched anteriorly. ~fo^ Port Blair, Andamans, 5 fms. S. Kemp. One. Genus Hippolysmata, Stimpson. 1914. Hippolysmata, Kemp, Rec. Iiid. Mas., X, p. 112. 1915. ExJiippolysmata, Stebbing, Ann. S. African Mtis., XV, p. 94. Stebbing has recently proposed to separate Hippolysmata ensirostris, along with a closely allied S. African form, as a distinct genus under the name Exhippolysmata. The characters employed 1 I am indebted to Dr. Annandale for this determination. Mr. Southwell informs me that the specimen from the Ceylon Pearl banks, recorded in the paper cited abo\e, was also found on this sponge. 102 Records of the Indian Musenin. {Yoh. XII, are those made use of in my key to the Indian species {loc. cit., p. 113): the rostrum is longer than in other species of the genus and is provided with an elevated dentate basal crest ; the telson is lanceolate, with the apex acute and unarmed. These characters appear to me to be altogether unsuitable for generic definition and are clearly of far less morphological value than those hitherto employed in the generic subdivision of the family. In young spechnens of H. ensirostris there is a pair of long spines at the tip of the telson, reaching far beyond the pro- duced median point and these may still be seen in a reduced con- dition, even in individuals 40 mm. in length. Stebbing also, when describing Exhippolysmata tugelae, notes the presence of a very small spine on either side of the telson tip. The claims of Exhip- polysmata to generic rank rest therefore on the rostral characters and in the fact that the telson has a median point instead of being rounded. If it be retained, its recognition requires to be balanced b}^ the institution of a considerable number of other " new genera," a procedure which seems unlikely to serve any useful purpose, while tending to confuse the natural afitinities of the component species of the family. Lysmatella, recentl}'' instituted by Borradaile for a species from the Maldives, is based on surer structural differences, but is none the less very closely allied to Hippolysmata. In the very brief preliminary diagnosis that Borradaile has given,' it is merely described as " related to Lysmata, but without mastigobranchs on the legs." The type species of the genus, Lysmatella prima, is described in the same paper. Three specimens, recently obtained in the Andanians, agree in every particular with the generic and specific descriptions that Borradaile has given ; but, unfortunatel}^, the information is so meagre that it is impossible to be certain of their identity. The Andaman specimens are, however, clearly related in a ver^^ close manner with the species of Hippolysmata belonging to the vittata group, the afifinity being shown not only by the almost exact correspondence in all structural details (except for the absence of epipods), but also in colour, the specimens when alive exhibiting the brilliant longitudinal red streaks that characterise H. vittata and H. dentata. If my identification of the Andaman specimens is correct it appears to me unwise, in the present state of our knowledge, to recognise Lysmatella in full generic significance. The presence or absence of epipods is in many cases a valuable aid to generic diagnosis in the Hippolytidae, but the number of these structures is variable in the genera Spirontocaris and Latreutes and in Hip- polysmata ensirostris the entire series is rudimentary. In many species referred to Hippolysmata the epipods have not been ex- amined and, on analogy with other genera, it would occasion no surprise if some were found to possess a reduced number. 1 Borradaile, Ann. Mag. Nat. Hist., (8), XV, p. 206 (1915). 1916.] S. Kemp : Notes on Crustacea Decapoda. 403 Hippolysmata ensirostris, Kemp. 1914. Hippolysmata eitsirosfris, Kemp, Rec. Ind. Mus., X, p. 118, pi. vii.figs. 1-4. A number of very interesting larval and post-larval specimens belonging to this species have recently been found off the Orissa coast. The post-larval specimens are about 14 to 16 mm. in length and in most of their characters agree closely with adults. The rostrum, however, is much shorter, usually not reaching the end of the antennal scale and the peraeopods, though well-formed, with perfect chelae, and with apparently the full number of sub- segments in the carpus of the second, possess rudimentary exopods on all pairs except the last. The apex of the telson is compara- FiG. 5. — Hippolysmata ensirostris, Kemp. I/ate larval stage. tively broad, with a pair of long spines that extend beyond the small median point by more than half their length. These spines appear to dwindle slowly in the course of further development and, though not mentioned in my original description, traces of them may still be found in specimens 40 mm. in length Judging by the number of teeth on the basal crest of the rostrum, these post-larval specimens belong to H. eiisirostris rather than to its variety punctata. Other specimens, found with the above, almost certainly represent the same species in its last larval stage, but show re- markable differences in structure (text-fig. 5). The rostrum is short, dorsally convex and bears teeth onl}^ on its dorsal margin and that on the carapace, which is deeply grooved oa either side 404 Records of the Indian Museum. [Voi., XII, of the mid-dorsal line, is large and procurved. The eye is exceed- ingly long, reaching beyond the end of the antennular peduncle; it is composed of two distinct segments, the proximal and more slender of the two bearing a conspicuous dorsal spine. The anten- nules and antennae are normally developed, except that the lateral process on the basal segment of the former is rudimentary. The third maxillipedes and all the peraeopods except the last bear very long exopods. The chelae of the first and second pairs are more rudimentary. The full series of gills appears to be present but there is no trace of epipods. The pleopods and uropods are well formed and the apex of the telson resembles that of the post- larval specimens, but possesses a pair of setae near the middle. So far as I am able to discover the larva differs from that of all other Carids hitherto described in the possession of a large spine on the eyestalk. oi|_|J: Off Puri, Orissa coast, S.Kemp. I'ourleen, posi-larval 4-4-^ fms. five, larval. Hippolysmata (LysmatcIIa) prima (Borradaile). 1915. Lysniotella prima. Borradaile, Ann. Mag. Naf. H/'sf.. {Si. W . p. 2og. Borradaile 's description of this species runs as follows : — " Rostrum "^.y , straight but upcurved at end, outreaching anten- nular stalk. Third maxilliped as stout as first leg, in which hand and arm are subequal, wrist a little shorter. Second wrist has 20-22 joints, the last the longest. Maldive Is." The Andaman specimens agree well with this description as far as it goes. The rostrum reaches beyond the end of the anten- nular peduncle and is almost or quite as long as the carapace ; it is furnished with 9 or 10 teeth above and with 5, 6 or 7 below. The posterior tooth of the dorsal series is situated a little in front of the middle of the carapace arid is separated by a marked interval from the rest; the latter are rather crowded posteriorly but more distantly spaced on the rostral blade; two of them (that is to say three teeth in all) are situated on the carapace behind the orbital notch. The teeth on the lower margin are as large as those on the upper. Thei e is a large antennal spine on the carapace and another, which is smaller, at the pterygostomian angle. The lateral process of the basal segment of the antennular peduncle is short, not reaching to half the length of the segment; its outer margin is strongly convex. The outer antennular flagel- lum is thickened at the base, but is devoid of the accessory ranms found in species oiLysmata. The antennal scale is narrow, scarcely broader behind than in front, and four times as long as wide. The outer margin is conspicuously concave and terminates in a sharp spine that reaches beyond the distal end of the lamella. The mouth-parts closely resemble those of H. vittata. All three maxillipedes bear epipods ; the exopod of the last pair reaches beyond the middle of the antepenultimate segment 1916.J S. Kemp : Notes on Crustacea Decapoda. 405 The first peraeopods are as described by Borradaile ; the chela resembles that of H. vittata, the fingers being shorter than the palm and meeting only at the tips when the claw is closed. The second legs are very slender, reaching beyond the antennal scale by nearly two-thirds the length of the carpus ; the merus is in- distinctly divided into 13 or more segments, while the carpus is composed of from 21 to 24 segments. The last carpal segment is the longest, about equal in length with the palm and one and a half times as long as the fingers. Of the remaining pairs of the peraeopods the third is the long- est reaching beyond the antennal scale by almost the entire length of the propodus. In each pair the merus bears conspicuous teeth externally near the lower border: 5 in the third pair, 5 or 6 in the fourth and 3 or 4 in the fifth. The posterior edge of the propodus is set with fine setae and some seven or eight very slender spinules The toothing of the dactylus is characteristic. As in H. vittata it bears 3 or 4 teeth on its posterior margin which increase in size distally ; the actual apex of the dactylus does not, however, take the form of a tooth, comparable to the others, but is extremely slender and, at the base, less than half the breadth of the adjacent tooth of the marginal series. The abdomen, telson and uropods do not appear to dift'er in any marked degree from those of H. vittata. The three specimens obtained are all ovigerous females; the largest is about 21 mm. in length. The colouration of living specimens is striking, the entire carapace and abdomen being marked with longitudinal stripes composed of small bright red chromatophores. On the carapace at the base of the rostrum the first three pairs of lateral stripes meet in the middle line. The three succeeding pairs are strictly longitudinal, but beneath them the striping on the carapace is oblique. In the middle of the abdomen there are about twenty longitudinal stripes. The eyestalks are heavily blotched with red ; the antennules and antennae are transparent with a faint yellow- ish tinge; the third maxillipedes and all the legs, except the second pair, are conspicuously banded with red. The tail-fan is dotted with red and the eggs are sage green. In colour, therefore, the species bears a striking resemblance to Hippolysmata vittata and H. dentata, but lacks the transverse bands on the abdomen that are found in the former of these species. -"^^q"'' Port Blair, Andamans, 8 fms. S. Kemp. Lliree. The three specimens were all obtained in a single haul of the net on rough ground in the southern entrance to the channel ofi' Ross I. EXPLANATION OF PLATE XXXVL Fig. I. — Thor discosoinafis , sp. nov., X 8^. ,, 2. — Phycocaris simnlans, gen. et sp. nov., X ii. ,, 3. — Latreutes porcinus, sp. nov., X 8|. Rec.Ind.Mus.. VoL.XIl. 1916. PLATE XXXVI. A.C.rhowdha,rv. Del. Phr.to^ra^7iu«-Sui-vejr.jfrndiB. Offices, Calcutta.. 1916. INDIAN HIPPOLYTIDAE. bor's Copy. RECORDS of tb( INDIAN MUSEUM Vol. XIII, Part II, No. 7. Notes on Crustaccd Decapodd in the Indidn Museum, VIII. 5. KEMP. C 7\ L C U I T A : MAY. 1917. VII. NOTES ON CRUSTACEA DECAPODA IN THE INDIAN MUSEUM. VIII. The genus Acetes, Milne-Edwards. By Stanley Kemp, B.A., Superintendent, Zoological Survey of India. In attempting to determine a large collection of Decapod Crus- tacea recently made by Dr, Annandale in J apan, China and Lower Siam, I found it impossible to come to a satisfactory decision regarding the identity of a species of Acetes, and it was only after examining the series of unidentified specimens in the Indian Museum that any definite conclusion was reached. It is with the results of this examination that the present short paper is con- cerned. In the first of his classical memoirs on the genus Sergestes Dr. Hansen remarked,^ ''Of Acetes 2 species are known (one of which has not been examined since 1837), ^^^ we possess 6 species, the distinctive characters of which are ver}- curious ; it is, however, impossible to give a good idea of the species. . . . without a consider- able number of figures." Twenty years have elapsed since this statement was made, but Dr. Hansen has unfortunately not made any further contribution to the subject. Although two additional species have been described, their characters are very imperfecth^ known and no fresh account of A. indicus, the species tor which Milne-Edwards founded the genus Acetes, has appeared. Acetes indicus has indeed been several times recorded from various locali- ties, but it is, I believe, quite impossible to recognize the species from the original description : all definite specific records are therefore open to doubt. The collection in the Indian Museum is not so rich as that in the University of Copenhagen, but comprises four distinct forms; three of these — all occurring in Indian waters — are in my opinion to be referred to known species, to A. indicus, Milne-Edwards, A. japonicus, Kishinouye, and A. ery thraeus, '^ohili; the fourth, obtained in Borneo, is undescribed. One described species, A. americanus , Ortmann.* is not represented in the collection. The four forms examined show the closest affinity with one another and all agree in the complete suppression of the last two pairs of peraeopods — the character on which Milne-Edwards estab- lished the genus, ' Hansen, Proc. Zool. Soc. London, 1896, p. 937. ■^ Ortmann, Decap. ScJiizop. Plankton- Exped., p. 39, pi. ii, fig. -' (1893). 44 Records of the Indian Museum. [Vol. XIII, In distinguishing the species the most important indications are those derived from adult males. The form of the petasma is a most reliable and satisfactory guide and, according to my ob- servations, an absolute criterion of specific identity, while good characters are also to be obtained from the sexual modifications of the external fiagellum of the antennule. In three of the four species the ultimate segment of the antennular peduncle of the male is always elongated to a very remarkable degree, a great contrast existing in this respect between the two sexes. It is curious that this very striking feature has not hitherto been noticed. In the fourth species {A. erythraeiis) the ultimate peduncular segment, in the vast majority of specimens examined, is short in both sexes; but in four males of small size from the vicinity of Penang, it is elongated as in the other species. The specific identity of these individuals is proved beyond doubt by the structure of the petasma. It seems, therefore, that in A. erythraeus the males are dimorphic; but it is very strange that no males with a long peduncle occur among several hundreds of specimens from other localities. The sexual characters of the female are more difficult to observe, but the third thoracic sternite offers distinctive charac- ters in each species; in A. japonicus its structure differs widely from that of any of the allied forms. The species may also be distinguished by characters other than sexual, and these, though for the most part less convenient, are useful in the determination of females and young individuals.^ Such characters are to be found in the proportions of the eye, in the form of the second segment of the antennular peduncle, in the ultimate segment of the third maxillipede, in the presence or ab- sence of a tooth on the inner margin of the basis of the third peraeopods, in the external border of the outer uropod and in the telson. It is evident from the collection in the Indian Museum that two species are often found together. In such cases, and when the specimens are numerous, identification is a tedious process, for each individual must be separately and carefully examined. Kishinouye was mistaken in supposing that the species can be determined by the number of teeth on the rostrum ; in the forms I have examined the rostrum is almost identical in struc- ture. This is also true of the toothing and sculpture of the carapace. The proportionate lengths of the segments of the third maxillipedes and legs aftord only very slight differences, and I have not been able to find any distinctions in the number or size of the branchiae. The species of Aceles are usually found gregariously, swim- ming in great numbers in mid- water or near the surface. They are apparently only met with in coastal waters; they occur near ' The petasma is, however, sufficiently developed for accurate identification in specimens less than half the maximum length attained by the species. igi;-] vS. Kemp : Note'x on Crustacea Decapoda. 45 the shore in the open sea, and are frequently common in estuaries and backwaters. They are often found where the water is of low salinity, and occasionally in places where it is quite fresh, but penetrate little if at all beyond the reach of tidal influence. The species are fished commercially both in India and Japan, the small size of the individuals being evidently compensated by the great abundance in which they are taken. In life the greater part of the body is probably transparent in all the species, but the cornea is black, and in one species at least there are red markings on the uropods. The precise distribution of the red pigment is perhaps different in different species, but on this point nothing precise is known. The only notes I possess on the colouration of living examples relate to specimens of A. japoni- cus collected in Mormugao Bay in Portuguese India, my description agreeing exactly with that given by Kishinouye. Dr. Annandale's notes on individuals caught in the Tale Sap in Lower Siam indi- cate an almost precisely similar colouration, but his collection contains both A. indicus and A. japoniciis, and it is not clear to which of the two species the description refers. The four species may be recognised by the following charac- ters : — I. Ciliated and non-ciliated portions of external border of outer uropod separated by a small but distinct tooth ; terminal segment of 3rd maxillipede not divided into sub-segments ; 3rd thoracic sternite of female not pro- duced backwards as a large plate. A. Telson reaching beyond middle of inner uropod, its apex pointed, without spinules ; a single clasping spine on external antennular flagellum of male. I. A tooth at distal end of inner margin of basis of 3rd peraeopods ; 2nd segment of antennular peduncle fully three times as long as broad; petasma without mem- branous coupling folds, its internal lobe strongly expanded at its proximal end, the distal portion terminating simply 2. No tooth on basis of 3rd peraeopods ; 2nd segment of antennular peduncle of female not more than two and a half times as long as broad ; petasma with a pair of folded coupling membranes armed with hooks, internal lobe little expanded proximally, its distal portion terminating in two large pointed processes B, Telson not reaching beyond middle of inner uropod, its apex truncate with a spinule on either side ; two clasping spines on external antennular flagellum of male [petasma without membran- ous coupling folds, its internal lobe very strongly expanded and conspicuously emarginate proxi- mally, the distal portion terminating simply] Ciliated and non -ciliated portions of external border of outer uropod not separated by a tooth ; terminal segment of 3rd maxillipede divided into three sub-seg- indiciis, Milne- Edwards. eiythraetis, Nobili. >y W\n tf d7tn5f insiilaris, sp, nov. ,u)ol L e 5errvy /^tv5 Wj 46 Records of the Indian Museum . [Vol. XIII, ments ; 3rd thoracic sternite of female produced back- wards as a large plate, the posterior edge of which is free and emarginate [external antennular flagellum of male with two clasping spines ; petasma without mem- branous coupling folds, its internal lobe not expanded proximally, the distal portion with bulbous termination and with a large process on its outer side] ... jnponicus, '' V: Kishinouye. In A. erythraeus , as already noted, the males are dimorphic, a form with a short antennular peduncle, resembling that of the female, being apparently by far the more abundant of the two. In the other three species only one type of male — a form with the ultimate segment of the peduncle greatly elongated — is known to occur. The four species agree in the following particulars : — The rostrum is exceedingly short and projects very little beyond the frontal margin of the carapace. It is, however, rather strongly elevated and terminates in a sharp point, behind which are two teeth, the foremost much the smallest. The anterior margin is almost vertical and is sinuous or concave. The carapace is as long as, or rather longer than the first two and a half abdominal somites; it bears conspicuous post-orbital and hepatic spines. The cervical groove is obsolete and no trace of it exists on the dorsum of the carapace. The upper limit of the branchial region is defined posteriorly by a blunt longitudinal ridge. The inner antennular flagellum is verj^ long and in both sexes shows the curious flexure described in detail by Kishinouye. The antennal scale is broadest at the base and is from 3*6 to nearly 4 times as long as wide. The outer margin is rather strongly convex and terminates in a small tooth that reaches almost to or a trifle beyond the distal end of the lamella. The mandibular palp consists of three segments, the basal one being exceedingly small and inconspicuous. The propodus of the second maxillipedes is a trifle longer than the merus ; the carpus is from two-thirds to three quarters its length and is fully three times the length of the dactjdus. The third, fourth and fifth segments of the third maxillipedes are more or less equal in lengthy while the fifth is from V2$ to 14 times as long as the sixth.' The first three peraeopods increase successively in length, the third pair reaching almost or quite as far as the third maxillipedes. In the first pair the merus is about as long as the chela ; the latter segment being from 1*2 to i'4 times the length of the carpus. In this pair of limbs, at the distal end of the carpus and at the I The proportionate lengths of the segments appear to show minor specific characters. \n A. japonicits, A. eiyfliraeiis and A. iiisiilaris the third segment is almost equal to, or a little longer than the fifth, whereas in A. indictis the former . is decidedly shorter than the latter. In ^. eiytliraeiis the third and fourth seg- ments, taken together, are i'3 times the len.gth of the fifth and sixth, in A. i)isularis and A. japonicits \'2 times and in A. indiciis '94 to it times. I9I7.] S. Kemp : l^otes on Crustacea Decapoda. 47 proximal end of the propodus, there is (in both sexes and in all four species) a patch of short barbed spinules, which, when the segments are flexed, forms a sort of grasping organ. The merus and carpus of the second pair are about equal in length' ; the carpus is from it to 1*3 times as long as the chela. In the third peraeopods the merus is a little shorter than the carpus and a little longer than the chela. The carpus is from i"3 to I "4 times the length of the chela. In the male, in the position normally occupied by the fourth pair of legs, there are two bluntly pointed and forwardly directed processes. The branchiae resemble those found in the genus Sergestes and do not appear to afford any specific differences in the four forms under consideration. The formula is: — vii viii ix X xi xii xiii xiv Podobranchiae ep. i-fep. ... Arthrobranchiae Pleurobranchiae I I I I I This formula agrees with that given by Ortmann* except that a small podobranch is present at the base of the second maxilli- pede. This branchia is perhaps absent in the Atlantic species that Ortmann examined. Arranged according to length, the order of the abdominal somites is 6, 4, i, 3, 5, 2 ; the sixth is about twice the length of the fifth and its greatest breadth is from i'6 to 2'0 times its length. The sixth somite is provided with a single very small spinule, placed dorsally on the posterior margin. The telson is sulcate above and is much shorter than the inner uropod. Genus Acetes, Milne-Edwards. 1830. Acetes, Milne-Edwards, Ann. Sci. nat., Pan's, XIX, p. 350. 1837. Acetes, Milne-Edwards, Hist. nat. Crust., II, p. 429. Acetes indicus, Milne- Edwards. (Text-figs. ia,b, 2(7, 3«, 4a, 5c, ja.) iSt,o. Acetes indicus, Milni-Edwards, Ann. Sci. nat., Paris, XIX, p. 351, pi. xi, figs. 1-9. 1837. Acetes indicus, Milne-Edwards, Hist. nat. Crust., II, p. 430. ? 1852. Acetes indicus, Dana, U.S. Explor. Exped., Crust., I, p. 608. ? 1890. Acetes indicus. Walker, jfourn. Linn. Soc, Zool., XX, p. 112. ? 1893. Acetes indicus, Henderson, Trans. Linn. Soc, Zool. (2), V, p. 452. ? 1905. Acetes indicus, Pearson, Ceylon Pearl Oyster Rep., IV, p. 75. i The merus is a shade longer than the carpus in A. japonicus and .4. erythraeus, a trifle shorter than the carpus in A. indicus and A. insularis. 2 Ortmann, Decap. Schizop. Plankton. Exped., p. 39 (1893J. 48 Records of the Indian Museum. [Vol. XIII, Except for the fact that fig. 9 of his ilhistrations shows a tooth on the outer margin of the external uropod — a character which indicates that the species is not the same as Kishinouye's A. japoni- cus — there is nothing in Milne-Edwards' description to indicate the precise identity of the form he examined. His material was, however, obtained from the mouth of the Ganges, in which, so far as I am aware, only one species exists, though three occur in the Bay of Bengal. The principal specific characters are as follows : — The eye is longer than in the other species and is a little more than one-third the length of the carapace. The stalk is rather more slender than usual and its length, in proportion to that of the cornea, is greater. Fig. I. — Riglit .intennular peduncle in dorsal \ie\v. a. Acetes indicus, a". /. Acetes insularis, rf". b. „ .. ?. g. „ „ ?. c. Acetes erythraeus, "low" cT . h. Acetes japonictis, d" • d. „ ,, ? i. „ „ ?. e. ,, ,, " high" (/. The basal segment of the antennular peduncle in the female is about the same length as that of the two distal segments com- bined; the second segment is from 3 to ■^^ times, and the third segment from 6 to 6| times as long as broad (text-fig. ih). In the male the second segment is sometimes more slender than in females, but the ultimate segment is always greatly elongated, much longer than the first, and from 10 to 14 times as long as broad (text-fig. la). The outer antennular flagellum of the male bears a single large clasping spine, with finel}'' serrate inner margin ; on the segment opposite the tip of this spine there is a group of 5 to 7 close-set spinules. The two basal segments of the flagellum are unusually long (text-fig. 2a). I9I7-] S. Kemp : Notes on Crustacea Decapoda. 49 The third maxillipedes, when extended forwards, reach a little beyond the tips of the third peraeopods and^ in the female, much beyond the end of the antennular peduncle. The ultimate segment is not divided into sub-segments. The basal segments of the third maxillipedes and peraeopods are proportionately stouter than in V-J CO. d. Fig. 2. — Outer .'intenmilar flagelluni of male. a. Acetes indicus. c. Acetes insularis. h. Acetes erythraeiis. d. Acetes japonicus. other species, and the setae with which the limbs are clothed are longer and more numerous. The basis of the third peraeopod bears a large tooth on its inner margin close to the insertion of the ischium (text-fig. 3(7), a character not found in any of the other three species. The third thoracic sternite of the female is very deeply chan- nelled longitudinally, the channel being continued backwards on 50 Records of (he Indian Mnseiwi. [\'ol. XIII, to the anterior portion of the fourth sternite. The anterior margin of the third sternite is deeply sunk and transverse or slightly con- cave. Behind the inner angles of the coxae of the third legs there is, on either side, a conspicuous tubercle (text- fig. 3a). Between the bases of the first pleopods, both in males and females, there is a large procurved tooth. The outer lobe of each half of the petasma (that is to say the portion nearest the pleopod) is more or less crescentic in shape with the antero-external border strongly thickened ; the shape of this portion is similar in all four species. The internal lobe is characteristic in form. At its proximal end it is truncate, much expanded externally and with a small process at its inner angle. Its distal portion is without any large processes, such as are found in certain allied species, and appears to consist of a central style surrounded by a thick coating, rather uneven in outline; its sur- face has a sort of honey-combed appearance, due to the presence of numerous small pits, each of which contains a modified booklet (text-fig. 4a). The telson reaches well beyond the middle of the inner uropod and is rather sharply pointed at the apex (text-fig. 5c). The angu- lar termination of the lobe at the proximal end of the infero- lateral margin is placed decidedlv nearer the base than the apex.' The ciliated and non-ciliated portions of the external border of the outer uropods are separated by a prominent tooth. In adults the proximal non-ciliated part is from I'l to r'3 times the length of the ciliated part (text-fig. ja) : in young individuals the proportionate length of the former is rather greater. Acetes indicus is the largest of the four species; full grown females, measured from the tip of the rostrum to the tip of the telson, reach a length of about 40 mm. The specimens examined are from the following localities: — "^^'^ Panvel Creek, Bombay ^Y~ Market at Ennur, near Madras ^^'^^-''^ Coconada, Madras Pres. ^\1^' Pratapnagore, Lower Bengal ^4-1^ ' Near Mud Point, R. Hugli, delta ^^ Matla R., Gangetic delta 10 ' » "["^ Bassein R. estuary, Burma ^^ Haingyi I., off Bassein R. ^^ S. of Purian Pt., Burma To^ Mouth of Rangoon R., Burma ^*^" Green I., Amherst, Tennasserim ^^ Mergui Archipelago, ii°28'N., 98°36' E. ej_ii Mergui Archipelago, i2°o' N., 98°2o' ^\J^^ Tale Sap, Gulf of Siam ^ As in A. eryf/i nietis. toxt-hg. ^a. J . Gaunter. Many. N. Annandale. Several. G. W. Wicks. Two. Mus. Collr. Few. Gangetic T. Southwell. Few. J. T. jLMikins. Two. n ' Investigator.' ^Lnny. (3nc. Many. Several, Many. 98°36' E. )i Few. 38°2o' E. ,, Several N. Annandale. Several, 1917.] S- Kemp : Notes on Crustacea Decapoda. 51 In several of these localities the species was undoubtedly obtained in brackish water, the lowest specific gravity of which I have a definite record being i'ooi5 (corrected) in the case of certain specimens from the Tale Sap. On the other hand the records from Coconada, Green I. and the Mergui Archipelago indi- cate that the species also occurs in the open sea near land. A. indicus was found in company with A. japonicus in the Tale Sap and in the I\tergui Archipelago, and with A erythraeus at Ennur. The distribution of the species^ as far as at present known, may be summarised as, — Bombay, Bay of Bengal and Gulf of Siam. The characters mentioned by Milne-Edwards being insuffi- cient to determine the species with any exactitude, the records by Dana, Walker, Henderson and Pearson are open to doubt. Even if accepted, they would not indicate any marked increase in our knowledge of the distribution of the species. Acetes erythraeus, Nobili. (Text-figs, jc-e, 2b, 3b, 4b, $a,d, yb.) igos- Aceies erytliraeus, Nobili, Bull. Miis. d' Hist, naf., Pcifi's, p. T,g4, te\t- fig. I. igo6. Acetes erytJiraeus. Nobili, Ann. Sci . imf.. Paris (9), IV, p. 23, p!. i, figs. 5^ 5«-/- The eyes are not quite so long as in /I. indicus, being only about one-third the length of the carapace ; the stalk is also stouter and, proportionately to the length of the cornea, rather shorter. The basal segment of the antennular peduncle of the female is about 1-3 times the length of the two terminal segments combined ; the second segment is decidedly stouter than in A . indicus, the length being not more than 2^ times the greatest breadth ; the third segment is from 4 to 4^ times as long as wide (text-fig. i^). In males a well- marked dimorphism appears to exist in respect of the proportions of the peduncular segments. In four small males from Penang, other- wise practically indistinguishable from the rest of the specimens in the collection, the ultimate segment is greatly elongated, precisely as in A. indicus. The second segment in these examples is about 3 times as long as broad, while the third is longer than the first and about 9J times as long as broad (text-fig. le). All the other males in the collection dift'er widely from the Penang individuals and from the males of any of the other three species, the antennular peduncle bearing a close resemblance to that of the female. In such specimens the basal segment is from it to i"3 times the length of the two following, the second segment is from 2 to 2^ times and the third from 4 to nearly 5 times as long as broad (text-fig. ic). The outer antennular flagellum of the male closely resemble that of A. indicus, and possesses only one clasping spine; the two basal segments are, however, shorter. In the males from Penang 52 Records ol the Indian Miiseitm. [Vol. XIII, the tip of the large spine is opposed by a group of 5 spinules, exactly as in A. indicus; in the others, as shown in text-fig. 26, only 2 or 3 spinules occur in this position. The segment immediately in front of that bearing the clasping spine bears an angular lobule. The third maxillipedes, when stretched forwards, reach about as far as the third peraeopods, and extend to the end of the an- tennular peduncle. There is no tooth on the inner border of the basis of the third peraeopods. Fig. c -Tliird thoracic slernite and basal se^"ment.s of third peraeopods of female. a. Acetes indicus. c. Acetes insular is. - j j. V l—L h. Acetes erythraeus. d. Acetes japoniciis. [ pl^-if oT . M"A>^ii€*ii> C\hj\f vw<- Tlie third and fourth thoracic sternites of the female show only faint traces of the deep longitudinal channel found in A. indicus and the former does not possess the pair of tuberculiform eminences present in that species. The third sternite is broadly triangular in shape; its anterior margin is elevated and is con- cave in the middle with a small rounded lobe on either side (text- fig- 3&). t^ if I9I7-] S. Kemp : Notes on Crustacea Decapoda. 53 As in A . indicus there is in both sexes a large hooked tooth between the bases of the first pleopods. The petasma differs from that of any other species examined in the possession of a pair of folded membranes on the anterior surface. The free edge of each is furnished with a series of minute hooks, by means of which the two halves of the petasma are coupled. The internal lobe is truncate and slightly concave at its proximal end, but is not broadly expanded as in A. indicus. The distal portion of the same lobe terminates in two large pointed processes with their apices directed obliquely outwards. The inner of these processes is larger and broader than the other and bears on its anterior surface two large falcate spines (text- fig. 46). ii\ Fig. 4. — Right half of petasma, seen from in front. a. Acetes indicus. c. Acetes insularis. b. Acetes eyythyaens. d. Acetes faponicus. Ha .^sc t^ The telson resembles that of A. indicus, but the tip is not quite so sharply pointed (text-figs. 5«, d). The ciliated and non-ciliated portions of the external border of the outer uropod are separated by a small tooth. The non- ciliated portion in adults is from 1-5 to 17 times the length of the ciliated part (text-fig. yh), a proportion differring considerably from that found in A . indicus. This species is smaller than A. indicus, large females being not more than 28 mm. in length. The males from Penang are only 14 mm. in length, whereas those from other localities may reach 20 mm. The occurrence of dimorphic males in this species is a feature of considerable interest, but further information is necessary before the phenomenon can be profitably discussed : it is unfortu- nate that such a small number of specimens are available from Penang. The case does not appear to be one of seasonal sexual dimorphism, for the males from Penang, all of which are of the 54 Records of the Indian Museum. [Vol. XIII, "high" form, were caught in the month of February, whereas those of the "low" form, exclusively obtained in other localities were obtained in the months of January, February, March and April. Acetes erythraeus was described by Nobili from the Red Sea; the specimens in the Indian Museum are from the following localities : — 96 9 5 10 96 96 Market at Ennur, near Madras .. . N. Annanclale. Few. Backwater at \'izagapatam, Mad- ras Pres. ... ... S. Kemp. Many. c!ot. Zool. Jnpoii., V, p. 163, text- figs. The eyes resemble those of the two preceding species but are rather shorter, a little less than one-third the length of the carapace. The basal segment of the antennular peduncle of the female is about i^ times the length of the second and third segments combined ; the second segment is fully 3 times and the third 5^ times as long as broad (text-fig. \i). In the male the propor- tions of the second segment are about the same ; the third segment is greatly lengthened as in A. indicus and A. in- sularis : it is longer than the basal seg- ment and at least 10 times as long as broad (text-fig. ih). The outer antennular flagellum of the female resembles that of A. insularis in the possession of two clasping spines, but does not bear the additional appa- ratus found in that species. One of the two clasping spines is very much longer than the other and is feebly serrate on its inner margin near the apex. The segments opposite the tips of the clasping spines each bear a small blunt process at the proximal end and one or two short spinules distally (text-fig. 2d}. Fig. 6. — Acetes japoiiivus. Terminal segment of outer maxillipede. I9I7] S. Kemp : Notes on Crustacea Decapoda. 57 The external maxillipedes do not reach quite so far forwards as the third peraeopods and extend to, or a little beyond the apex of the .antennal scale. The terminal segment of the external maxillipede differs from that of all the other species in being divided into three sub-segments; of these the middle one is the shortest and the last the longest (text-fig. 6). There is no tooth on the inner margin of the basis of the third peraeopods. The third thoracic sternite of the female is altogether peculiar ; it projects backwards from the base of the third legs in the form of a large plate, posteriorly overlying the fourth sternite. It is slightly depressed in the middle line, its lateral edges are posteriorly convergent and its distal margin, which is free, and in consequence easily visible in lateral view, is conspicuously emarginate (text- fig. 3^). Oy. Fig. 7. — Outer uropod, with portion of external maroin more highly magnified. a. Acetes indicus. c. Acetes insular is. b. Acetes erythraeus. d. Acetes japonicus. The large-hooked tooth found in A. indicus and A. erythraeus between the bases of the first pleopods is replaced, as in A. insularis, by a small pointed process. The internal lobe of the petasma is truncate at its proximal end and scarcely at all expanded. The distal portion is bulbous at the tip and set with numerous mmute booklets; on its outer side it bears a large process usually terminating in a long and very fine point (text-fig. ^d). The length of this pointed process is variable ; sometimes it reaches to the end of the lobe to which it is attached, while occasionally it terminates abruptly with a blunted apex. The sixth abdominal somite, in lateral view, is a little more slender than in the other species, its length being usually twice its greatest depth. 58 Records of the Indian Museum. [Vol. XIII, 1917.] The telson resembles that of .4. erythraeus and A. indicus, but the tip is rounded rather than pointed (text-fig. 5/). I have not been able to detect the pair of small teeth mentioned by Kishinouye , but the outer corners of the apex are sometimes a little angular. The external border of the outer uropod differs from that of all the other three species in the complete absence of the tooth between the ciliated and non-ciliated portions. In adults, more- over, the latter part is a little longer than the former, the reverse being the case in the other forms (text-fig. 'jd). In very young specimens the proportions are rather different, the non-ciliated part being equal to, or even a trifle longer than the ciliated part. Large specimens reach a length of about 26 mm. Acetes japoniciis was described by Kishinouye from the Inland Sea of Japan and from Korea. Specimens in the Indian Museum are from the following localities : — ^"^p"''^ Mormugao Bay, Portuguese India ... S. Kemp. Many. ^-|^ Kilakarai, Ramnad dist., S. India ... ,, Three. 2-69_* Ennur backwater, near Madras ... N. Annandale. Three. 9JLSi:9 Mergui Archipelago, n°i7'— 11'^28'N., 98°29'— 98°36' E ... ... 'Investigator.' Several. Patani R., below town of Patani, Siamese Malay States ... ... ... N. Annandale. Six. Tale Sap, near Singgora, G. of Siam ... ,, Many. From market, Osaka, Japan ... ,, Many. Niigata, Japan ... ... ... ? Several. 1 o 96 9 1 10 9692 9693 1 O In the Patani river the species was found in fresh water, but in a situation subject to tidal influence; in Mormugao Bay it was taken in water of specific gravity i"or65 (corrected), while at Kilakarai it was obtained in pure sea water in the vicinit}" of a coral reef. The species was found in the Mergui. Archipelago and in the Tale Sap in company with A. indicus, and in the Patani river with A . erythraeus. The known distribution may be summarised as, — W. and S. coasts of India, lower parts of Bay of Bengal, Gulf of Siam, Korea, Japan. or's Copy. RECORDS of the INDIAN MUSEUM Vol. XIII, Part V, Nos. 15, 17. Notes on Crustdcea Decapodd in the Indian Museum, X, XI. By 5. KEMP. C7\LCU1T?\: SEPTEMBER, 1917. XV. NOTES ON CRUSTACEA DECAPODA IN THE INDIAN :\iUSEUM. X . H YMENOSOMA TIDAE. By StanIvEy Kemp, B.A., Superintendent, Zoological Survey of India. The small crabs belonging; to the famil}^ Hymenosomatidae are singularly unobtrusive in habit and unless very abundant are liable to escape notice. A few species are found in salt water of no great depth, and are not infrequently taken on coral reefs or living under stones between tide-raarks ; but the majority (at any rate on the Indian coast) appear to inhabit estuaries or lagoons where the water is of low or variable salinity. Two species of the family have, indeed, succeeded in establishing themselves in pure fresh water and one has been taken in lakes 3,000 ft. above sea level. ^ Most of the species prefer a bottom composed of mud, which, when matted with the fine hairs on their bodies, doubtless assists them in escaping detection. In many instances the mud forms such a dense coating on the carapace and appendages that it is almost impossible to remove it without injury to the specimen. The legs are very brittle ; some species appear to throw them off almost without provocation, and this so constanth^ occurs with Elamena [Trigonoplax) ungiiiforiiiis that it is almost impossible to preserve a perfect example. Among the crabs recently collected on the Indian coasts several species of Hymenosomatidae are represented. Alcock in his memoir on the Indian Catometopes* was able to give an account of five species and two more have since been recorded. Six others, all of which have not hitherto been described, are here added, bringing the total number of known Indian forms up to thirteen. The new Indian species were all obtained in brackish water. Four were found by myself in Portuguese India, one being a very abundant spec" which has also been collected by Dr. F. H. Gravely in the Cochin oackwaters. The other two were taken by Dr. Annandale and myself in the vicinity of Calcutta. Both these species exhibit very peculiar structure and one of them, obtained on the banks of the River Hughli, cannot be included in any of the genera hitherto described. There can be no doubt that numbers 1 Halicarciniis laciistris (Chilton i [see p. J47, footnote] and Rhviichoplox iiitroversiis, sp. nov. ■2 Altock, Jonni. Asiat. Soc. Bengal, LXIX, p. 3S5 (iqoo). 244 Records of the Indian Museum. \\Oh. XIII, of additional species yet remain to be discovered on the Indian coasts. I have included descriptions of two new forms obtained by Dr. Annandale during his recent tour in the Far East. One of these is from the Tai Hu in the Kiangsu province of China, a lake which is fresh at all times of the year; the other was found in brackish water in the Tale Sap in Lower Siam. We are at present very far from possessing a clear knowledge of the species referred to this family. The descriptions and figures of many of the older authors are a constant source of difficult^' and the identity of numerous species described in the earlier half of the nineteenth century still remains obscure. The confusion is accentuated by differences of opinion regarding the genera. Many authors appear to have distributed their species almost at random and Haswell,' who places all the Australian forms in the genus Hymenosoma, has expressed the opinion that '' the subdivision. . . . I'IG. I. — Hymenosoma oybiciilare, Desmare.sl. Anterior part of carapace, seen from below. into the genera Hymenosoma , Hynienicus and Halicarcinus appears to be unnecessary and based on extremely slight points of distinc- tion." This view finds no support from subsequent writers, and it is evident that its author was unaware of the characters of the true Hymenosoma ; nevertheless, as explained below, I believe him to have been right in uniting Hynienicus and Halicarcinus. The following notes on the genera are based on the material in the Indian Museum, which contains in addition to twelve Indian species, a number of specimens from China, Australia, New Zealand , S. Africa and the Falkland Is., all the known genera with one exception being represented. Hymenosoma was described by Desmarest in 1825,* the type species being H. orhiculare from the Cape of Good Hope. It is one of the most clearly defined of the genera comprised in the famil}^ differring widely from all others in the complete absence of the epistome (text-fig. i). The external maxillipedes almost encroach ' Haswt'll, Cat. Australian Crust., p. 114 (1882). '^ Desmarest, Consid, gen. Crust., Paris, p. 163 (1825), igi7'] S- Kemp : Notes on Crustacea Decapoda. 245 on the bases of the antennules and the buccal cavern is not limited anteriorly by a ridge. The ischium of the external maxillipedes is a little longer than the merus ; both segments are slender and, when normally folded, gape in the middle line, the underlying appendages being partially visible. In the abdomen of the male the sutures of all the segments are distinct. The regions of the carapace, as in most genera of the family, are defined by fine-cut grooves. Numerous species have from time to time been placed in Hymenosoma, but in the majority of instances the reference is erroneous and it is now practically certain that the genus is mono- typic. Stimpson's H. geometricum^ is synonymous with H. orbicu- lare and Guerin Meneville's H. gandichaudii ,^ though included in the genus by Milne-Edwards,* is evidently a species of Halicarcinus. Halicarcinus was established by White in 1846,* the type Fig. 2. — Halicarcinus plaiiatus (Fabr.). Anterior part of carapace, seen from below. species being Fabricius' Leucosia planata^ from Tierra del Fuego. In this genus the epistome"is a conspicuous plate, and the buccal cavern is bounded anteriorly by a transverse ridge (text- fig. 2). The ischium and merus of the external maxillipedes are of similar size and are broad segments, completely or almost completel}' clos- ing the buccal cavern. As in Hymenosoma the grooves on the upper surface of the carapace are clean cut and, in the abdomen 1 Stimpson, Proc. Acad. Sci. Philadelphia, X, p. 108 [54] (1858) and Smiths. Misc. Coll., XLIX, p. 144 (1907). Stebbing-, in Marine Invest. S. Africa, IV, p. 50 (1905) and Ann. S. African Miis., VI, p. 332 (1910), retains H. geometricum as a distinct species, but has since agreed that it is synonymous with H. orbiculare [see Trans. Roy. Soc. Edinburgh, L, ii, p. 270 (1914)]. ^ Guerin Meneville, Voy.de la ' Coquille' , II, ii, l'"« div., p. 21 and Atlas. Crust., pi. ii, figs. 12-18. 'A Mihic-Edwards, Ann. Sci. nat., Zool., Paris (3), XX, p. 222 (1853). + White, Ann. Mag. Nat. Hist, (i), XVIII, p. 178 (1846). 6 For references see Stebbing, Proc. Zool. Soc. London, 1900, p. 524; Doflein and Balss, Mitth. natiirhist. Mas. Hamburg, XXIX., p. ^5 (1912) and Chilton. Subantarctic Is. of New Zealand, p. 609 (1910). 246 Records of the Indian Museum. [Vol. XIII, of the male, the sutures of all the segments are distinct. In m\' interpretation of its limits, Halicafcinus comprises species with simple rostra as well as those in which it is trilobate or tridentate. Lucas's Homhronia,^ suggested as a generic name for Jac- quinot's Hymenosoma depressa''' from the Auckland Is, and Nico- let's Liriopea,^ based on two species from Chili, are generally regarded as synonyms of Halicarcinus, and Dana's Hymenictis* is separated by such slight distinctions that it cannot in my opinion be retained as a separate genus. In describing Hymenicus Dana says : " In this genus the front has not the three teeth of Halicar- cinus (between which the flexed first antennae are seen), but a simple rounded or trilobate prominence forms the front, and the first antennae are covered. The feet are much longer and more slender than in any of the species of Halicarcinus, seen by the author." On comparing H. varius, the type species of Hymeni- cus, with Halicarcinus planatiis, the points to which Dana has drawn attention are readily appreciated. The difference, however, is in reality of very slight morphological importance and is entirely due to the greater development of the front in H. varius, the dis- position and structure of the related parts being as nearly as possible identical. Examination of allied forms shows that a wide variation exists in the form of the front and affords conclusive evidence that the character is of specific rather than generic value. The comparatively great length of the legs in H. varius — the only other point mentioned by Dana — is clearly insufficient as a generic criterion; the external maxillipedes are almost identical in struc- ture with those of H. planatus and, as in that species, the sutures of all the segments of the male abdomen are distinct. But though Dana's Hymenicus must, through the characters of its type species, be placed in the synonymy of Halicarcinus, it does not follow that all the species hitherto referred to Hymenicus must be transferred to White's genus. The two Indian species described by Alcock,^ together with four others dealt with below, appear to offer distinctive characters. In most particulars they agree with Halicarcinus, but the external maxillipedes are much more slender, with the ischium conspicuously smaller than the merus ; when normally folded they gape widely in the middle line, leaving parts of the underlying appendages exposed (see text-fig. 7, p. 259). In the abdomen of the male, moreover, the 3rd, 4th and 5th segments are fused, with complete obliteration of the sutures (see text-fig. 9, p. 259). The rostrum is variable in form, but is normally tridentate or trilobate. ' Lucas, in Hombron and Jacquinot's Voy. an Pole Siid, Zool., Ill, Crust. p. 62 (1853). ■^ Jacquinol, Alias to above, Cnisf., pi. v, fig-.s, 34-39 ( 1S42-53I ; Chilton, Ann. Mag. Nat. Hist. ' 7 ), XIX, p. 146, pi. v (1907). It is perhaps doubtful whether this species really belongs to Halicarcinus as here defined, for the grooves on the upper surface of the carapace are not shown in either of the figures. 3 Nicolet, in Gay's Hist, fisicay politica tie Chile, Zool., Ill, p. 158 ('184c)). + Dana, U. S. Explor. Exped., Crust., I, p. 3S7 (1852). ■' .Alcock, Jonrn. Asiat. Soc. Bengal, LXIX, p. 388 (1900). 1917-] vS. Kemp : Notes on Crustacea Decapoda. 247 As a generic name for this group of species I have emplo\^ed Stimpson's Rhynchoplax,^ though unfortunately I cannot be al- together certain that its application is correct. Stimpson does not state that any parts of the male abdomen are fused and his reference to the external maxillipedes is decidedly confusing, his only remark being " ischium-joint. . . .scarcely longer than meros/' a description that applies if anything better to Halicarcinns than to the group of Indian species. On the other hand Rhynchoplax messor, the type species of the genus from Simoda in Japan, ap- pears specifically to be an exceedingly close relative of Alcock's '^ Hymeniciis'" wood-masoni , both species, apart from other resem- blances, possessing a series of teeth on the upper border of the merus of the chelipede. The question cannot finally be settled until further specimens of Rhynchoplax messor are examined. The types were, I understand, destroyed by fire in 187 1 and the species has not been recorded since Stimpson's time. To distribute the numerous described species correctly beween the genera Halicarcinus and Rhynchoplax, as here defined, is a matter of very great difficulty, but from the figures and descriptions which have been published I conclude that the following species may safely be referred to the genus Halicarcinus,'^ — Hyinenosoma gaudichaudii, Guerin Meneville,^ Halicarcinus pubescens, Dana,* Hymenicus puhescens, Dana,^ Hymenicus varius, Dana," Halicar- cinus ovatus, Stimpson,'' Hymenosoma tridentata, Jacquinot,^ Hy- menosoma rostratuni, Has well, ^ Elamene pilosa, A. Milne-Edwards,''' Hymenosoma laeve, Targioni-Tozzetti,'^ Hymenicus marmoratus, Chilton.^* and Hymenosoma lacustris, Chilton.'^ i Stimpson, Pioc. Acad. Sci. Philadelphia. X, p. loQ [55] (1858) and Smiths. Misc. Coll., XLIX, p. 147 (1907). ■^ In addition to the type species of the genus I have seen specimens ot H. ovatus, H. varius, H. rostratus and a species from the .Vustralian coast whicli is perhaps undescribed. •^ Guerin Meneville, loc. cit. supra p. 245. * Dana, U. S. E.xploi'. Exped., Crust.. I, p. ,^86, pi. wiv, hg. 8. *> Dana, ibid., p. 388, pi. xxiv, figs. 11 a-c. "^ Dana, ibid., p. 387, pi. xxiv, fig. 9. '' Stimpson, Proc. Acad. Nat. Sci, Philadelphia, X, p. 109 [55] UiS58) and Smiths. Misc. Coll., XI, IX, p. 146 (1907); Stebbing, Proc. Zool. Soc. Loudou, 1900, p. 525, pi. xxxvi A. Chilton, in Suhantarctic Is. Neiv Zealand, p. 609 (1910) suggests that H. ovatus is synonymous with Jacquinot's H. tridentata.. ^ Jacquinot, in Hombron and Jacquinot's Voy. an Pole Slid, ZooL, Atlas, Crust., pi. V, figs. 27-33. L^sually regarded as a synonym of H. planatus. Chil- ton, loc. cit., igio, p. 609, suggests its retention at least in a subspecific significance. 9 Haswell, Proc. Linn.Soc. N. S. Wales, W, p. 550 (1882) and Cat. Austral- ian Crust., p. 116 (1882) ; Baker, Trans. Roy. Soc. S. Australia, XXX, p. 114, pi. iii, figs. 2, 2a,b ( 1906). '" A. Milne- Edwards, Noiiv. Arch. Mas. Paris, IX. p. 7,22, pi. wiii, figs. 6, ba-e (1873). il Targioni To/zetti, Crost. \'iaggio ' .Magenta,' p. 179, pi. \i. figs, yi-e (1877)- '■2 ( hilton. Trans. A'. Zealand Inst., XI \ , p. 172, pi. viii, figs. \a-c (i88l). 1'^ C'hilton, Trans. N. Zealand Inst.. XIV, p. 172 (1881) [as Elamenal laciistris']; ibid., XI, IV, p. 128 (1912); ibid., XI, VII, p. 316, fig. I (1915) ; Fulton and Grant, Proc. Roy. Soc. Victoria, XV, p. 59, pi. viii (1902) ; Grant and McCulloch. Proc. Linn. Soc. X. S. Wales, XX.Xil, p. 153 {1907). 248 Records of the Indian Museum. [\'ol. XIII, The generic position of a number of other species is doubtful, but I think it will eventually be found that all those from southern latitudes hitherto referred to the genera Hymenicus and Hymeno- sonia ' belong in reality to Halicarcinus. H. planatus, if the records are to be trusted, is circumpolar in distribution and the species listed above are without exception from southern latitudes. The forms that can be referred to Rhynchoplax are, on the other hand, all found on the Asiatic coasts, from which no representative of Halicarcinus has yet been obtained. The genus Rhynchoplax, in my estimation, comprises Stimp- son's two species, R. messor from Japan and R. setirostris from Hong Kong, de Man's Elamene filholi^ from near Batavia, Alcock's Hymenicus wood-masoni and H. inachoides from India and six other species described below. It probably includes also Miss Rathbun's R. coralicola^ from Singapore. A species of H3mienosomatidae found on the banks of the R. Hughli, near Calcutta, does not appear to be admissible into any of the genera hitherto recognized ; it is described below under the name Hymenicoides carteri. In its structure this species shows a high degree of specialization and generically is related to Halicar- cinus and Rhynchoplax. It agrees with the former of these genera in having the sutures of all the segments of the male abdomen dis- tinct and with the latter in the slender form of the basal segments of the third maxillipedes : it differs from both in the remarkably elongate dactylus of the latter appendages and in the entire absence of a rostrum (see text-fig. 16, p. 267). In Hymenicoides the antennule is completely exposed in dorsal view. This character has frequently been used as a generic criterion, but in my opinion is of specific importance only, being due almost entirely to the extent to which the rostrum is reduced. In Rhynchoplax the rostrum is normally trilobate and well de- veloped, but in R. nasalis, sp, nov., the lateral portions are sup- pressed, with the result that the antennules, just as in Hymeni- coides carteri, are visible from above. The genus Elamena was established by Milne-Edwards in 1837,* the type species being Desmarest's Hymenosoma mathaei^ from the lie de France. Haswell's suggestion that this species is merely the young of Halicarcinus planatus'^ has been contested by Stebbing and is certainly incorrect. That Riippell's identifica- tion'' of Desmarest's species is correct may be assumed from the ' Kxcepl, of course, Nviiu'iiosoiitu orbiciilnre and the synonymous //. geo»iet- I'lcnm. 2 De Man, Ai-cli.f. Natiii-gesch., LIII, i, p. ;,N6, pi. xvii, fig. 3 (1887;. ' Hathbun, K. Danske Vid. Sehk. Skviff. i;), iiatiirviiL og'math., V. p. 316, lexl-fig. 5 ( 1910). * Milne-Edwards. Hist. iiat. Cnisf., II, p. 3;, ( 1837J. 6 Desmarest, Cousiif. gen. Crnsf.. Paris, p. 163 (1825I. 1 have not seen this species. 6 Haswell, Cat. Australian Crust., p. 114 (1882). ' Riippell. Beschveih. .Ahhild. 24 Arteii Krnhheii. Frankfurt, p. .'i. pi. v, fig. I (1S301. 1917-] S. Kemp : Notes on Crusiacea Decapoda. 249 fact that his description and figure is quoted by Milne-Edwards, who, as Stebbing has remarked, probably had Desmarest's speci- men before him when he wrote. Paulson's figure* differs consid- erably from that given by Riippell ; the carapace is of much greater proportionate length and bears grooves on its upper sur- face much as in Halicarcinns and Rhynchoplax. Stebbing has pointed out {loc. cit.) that Milne-Edwards' subsequent reference to the species in 1853'^ is almost certainly erroneous; the genus is here credited with a tridentate rostrum, a character not found in Desmarest's species In Elamena, as represented by the species in the Indian Museum, the carapace is very greatly depressed, sometimes of wafer-like thinness, and the regions of its upper surface are not defined by the fine-cut grooves found in the other genera. The epistome is conspicuous and sometimes of great length. The ex- ternal maxillipedes completely close the buccal cavern and the ischium, though somewhat variable in size, is always longer than the merus (see text-fig. 25, p. 276). As in Rhynchoplax the 3rd, 4th and 5th segments of the male abdomen are fused, and the sutures between them obliterated. The front, or rostrum, is simple, never trilobate, I agree with Alcock^ that Trigonoplax is, at most, only a subgenus of Elamena. It was described by Milne-Edwards in 1853/ the type species being de Haan's E. unguiformis.^ As has been pointed out above, Milne-Edwards when writing in 1853 ap- pears to have misunderstood the characters of his own genus Elamena, and the foundation of Trigonoplax seems to have been a direct result of this mistake The only constant differences that I am able to find between Elamena and Trigonoplax do not appear to be important and it is probable that when the characters of the species are better understood, the latter will come to be regarded as a synonym of the former. Six species of Elamena have been found on the Indian coasts and are referred to below ; of these three (perhaps four) belong to the subgenus Trigonoplax. Other representatives of the genus are E. mathaei (Desmarest),^ the type species, found at Reunion and in the Red Sea, E. producta, Kirk'' (with which E. kirki, Filhol,^ is I Paulson, Crust. Red Sea. Kiciv, p. 71, pi. ix, figs. 3, yi,b (1871 i. ■i Milne-Rdwards, Ann. Set. iiaf.. Zoo}.. Paris (},^. X.X, p. 223, pi. xi, figs. 4. \a (1853). i Alcock, Jotirn. Asiat. Sac. Bengal. l.Xi.X, p. 38(1 (lyooi. * Milne-Edwards, Ann. Sci. naf.. Zool., Paris (3), XX, p. 224 (1853). * De Haan. in Siebold's Fauna 'Japonica, Crust., p. 75, pi. xxix, fig. i. pi. H (1839). * For references see p. 248, tooLnotes 4. 5. FAamene truncata, Lenz (not .\. M,-Ed\v.), Ahhandl. Senckenherg. Natnrforscli. Ces. Frankfurt. XXVII, i, p. 367, pi. xlviii, figs. isa,b (1902) is apparently synonymous. ■^ Kirk, Trans. N. Zealand Inst.. XI, p. 395 ( 1878) ; Filhol, Recueil de Mem. Inst. France, Miss, a I'tle Campbell, Zool., p. 404, pi. I, figs, i, 2 (1885) : Chil- ton, Rec. Canterbury Mas., I, p. 294 (1911). ' F'ilhol, loc. cit. supra, p. 405, pi. xlvii, tigs. 0, 8 (1885). 250 Records of the Indian Museum. [Voi,. XIII, apparently synonymous) and E. longirostris, Filhol/ both from New Zealand. The position of E. quoyi, Milne-Edwards,"^ E. mexi- cana, Milne-Edwards^ and E. ivhitei, Miers,* is doubtful. E. pilosa, A. Milne-Edwards, as already pointed out, is probabl}^ a species of Halicarcinus, while E. filholi, de Man, appears to belong to Rhynchopiax. E. miniUa, A. Milne-Edwards," whatever it may be, is certainly not an Elamena. Elamenopsis was established by A. Milne-Edwards in 1873 for E. lineatus,'^ a species found in New Caledonia I have seen no specimens of the genus and have not been able to satisfy myself regarding its position in the family. It is said to form a link be- tween the Hymenosomatidae and Pinnotheridae. From the des- cription it appears to be related to Rhynchopiax , but the walking legs are much shorter and stouter than in any species of that genus that I have seen. The principal characters of the other five genera ma}' be summarised in the following way : — 1. There is no epistome. [The external maxillipedes are slender and do not nearly close the buccal cavern. In the abdomen of the male the sutures of ail the seg- ments are distinct] ... ... ... Hynieiiosonia, Desmarest. II. The epistome is well defined and frequenth- very long. .-1. The regions of the carapace are defined by sharp- cut grooves. The ischium of the external maxilli- pedes is not longer, frequently much shorter than the merus. 1. A rostrum is present and is frequently trilo- bate or tridentate. The dactylus of the ex- ternal maxillipedes is short (normal). a. The external maxillipedes are broad and completely, or almost completely, close the buccal cavern. In the abdomen of the male the sutures of all the segments are distinct ... ... ... Hnlicarciniis. White {=zHyni- b. The external maxillipedes are slender and eiiiciis. Dana), do not nearly close the buccal cavern. The 3rd, 4th and 5th segments of the male abdomen are fused and the sutures obliterated ... ... .. RJiyiicliopla.w 2. The rostrum is altogether absent. Ihe dac- Stimpson. tylus of the external maxillipedes is abnor- mally long, reaching the hinder limit of the buccal cavern. [The external maxillipedes are very slender and do not nearly close the buccal cavern. In the abdomen of the male the sutures of all the segments are distinct]... llynienicoides, <>en. nov. i Filhol, loc. cit. siipi'd, p. 403, pi. xlvi, fig. 7 (1S85). 2 Milne-Edwards, Ann. Sci. nat., ZooL, Pan's iT,), XX, p. jjt,. pi. \i. fig. :; 873). " A. Milne-hdwards, ibtd.. p. 324, pi. xviii, fig. 4. I9I7'] ^'^^ Kemp : Notes on Crustacea Decapoda. 251 B. The surface of the canipace is smooth, rarely uneven ; its regions are never dehmited by sharp- cut grooves. The ischium of the external maxiili- pedes is longer than the merus. [The rostrum, when present, is simple. The external maxilli- pcdes are broad and completely close the buccal cavern. The 3rd, 4th and 5th segments of the abdomen of the male are fused and the sutures obliterated] ... ... . ... Elameua, Milne- Kd wards. Of these genera only the last three are found on the Indian coasts. Genus Rhynchoplax, Stimpson. 1S5S. Rlivaclwplax, Stimpson, Proc. Acad. Sci. Philadelphia, .\. p. 1119 t55], 1900. Hy)nemcjts, .\lcock (not of Dana), Jouvii. Asiat. Sac. Bengal, LXIX, P- 387- Hjoy. Rhynchoplax, Stimpson, .Smiths. Misc. Coll., XI, IX, p. 147. The carapace is circular, ovate or polygonal in outline and is depressed ; the upper surface is sunken with the usual grooves sharply defined and the margin upturned. The rostrum is triden- tate or trilobate, the lateral processes very rarely absent. The epistome is of good length and the buccal cavern is bounded an- teriorly by a sharp ridge. The external maxillipedes are compara- tively slender and, when normally folded, gape widely in the middle line ; the merus is longer than the ischium and the dactylus is, as usual, short. The chelipedes in both sexes are stouter than the walking legs. In the abdomen of the male the 3rd, 4th and 5th segments are fused and the sutures between them completely obliterated. This genus is very closely related to Halicarciims, but is dis- tinguished by the more slender merus and ischium of the external maxillipedes and by the fact that certain segments of the male abdomen are fused. The six Indian species of Rhynchoplax together with the two obtained by Dr. Annandale in Siam and China may be distinguished in the following manner: — I. .\ large forwardly directed tooth or process on either side of carapace above base of ist walking legs [ros- trum tridentate ; a sharp post-ocular tooth visible in dorsal view]. A. Carapace subcircular, its antero-laleral border armed with one or two blunt teeth ; merus of cheli- pede armed with several strong teeth on its upper border ; dactyli of last three legs armed with a series of small teeth. I . Two teeth on antero-lateral border of carapace ; chela of adult male more than twice as long as high, palm rounded below, fingers not gaping and armed with regular teeth ... ... R. ivood-inasoin J. Only one tooth on antero-lateral border of ( Alcock). carapace ; chela of adult male much le.ss than twice as long as high, palm keeled below, fingers widely gaping and with irregularly disposed teeth ... ... ... A", alcocki, sp. nov. 252 Records of the Indian Museum. [Vol. XIII, B. Carapace octagonal ; its antero-lateral border without teeth ; inerus of chehpede without teeth on its upper border ; dactyh of last three legs with a single large tooth near apex II. No tooth on side of carapace above base of ist walking legs [no teeth on antero-lateral border of carapace]. A. Rostrum trilobate or tridentate ; basal segment of antennular peduncle not visible in dorsal view ; penultimate piece of abdomen of male longer than broad, without tubercle. I. Rostrum composed of three very broad lobes ; post-ocular tooth not visible from abo\e ; legs stout, dactyli without teeth 2. Rostrum composed of three narrow lobes or teeth ; post -ocular tooth visible from above ; legs slender, dactyli with teeth. a. Carapace not longer than broad ; rostrum composed of three lobes ; 2nd walking legs not more than 2i times length of carapace. i. Postero-lateral border of carapace nor- mal ; dactyli of walking legs very strongl)' curved and with very large teeth ; terminal segment of male abdo- men broader than long ii. Side-walls of branchial region of cara- pace reflected upwards, forming a crest outside the true postero-lateral border ; dactyli of walking legs moderately curved, with small teeth ; terminal seg- ment of male abdomen much longer than broad b. Carapace much longer than broad, rostrum composed of three long teeth ; 2nd walking- legs more than 3 times length of carapace [dactyli of walking legs moderately curved, with small teeth ; terminal segment of male abdomen as long as broad] B. Rostrum composed of a single tooth-like process ; basal segment of antennular peduncle completeK visible in dorsal view ; penultimate piece of abdo- men of male broader than long, with a large tubercle at distal end [no post-ocular tooth ; dactyli of last three legs with a single tooth] R. octagonalis, sp. nov. R. c/eineloi, sp. no\ R. e.xigmis, sp. nov, A', introverstis, sp. nov. A'. inacIioides, Alcock. A*, luisolis, sp. nov. Rhynchoplax wood-masoni (Alcock). igoo. Nymein'ciis ivooif-iiiaso)/!, Alcock, yoin-i/. Asinf. Spc. Bengal, LXIX, p. 388, and (1902) Illiist. Zoo/. Investigntoy,' \A. Ixiv, fig. 4. A few particulars regarding the structure of this species, some of which are additions to Alcock's description, are given below in the course of a comparison with the closely allied R. alcocki. Stimpson's Rhynchoplax messor from Simoda appears also to be a related form, agreeing in the presence of a series of teeth on the upper aspect of the carpus of the chelipede. In the Japanese 1917. S. Kemp : Notes on Crnstacea Decapoda. 253 species, however, the carapace is stated to be triangular, with only two teeth on the lateral border, and the median tooth of the rostrum points obliquely upwards, instead of being depressed as in R. wjood-masoni. The carpus of the chelipedes bears on its upper surface three or four small teeth; in adult males of R. wood- ntasoni one such tooth is sometimes found near the meral articula- tion, but it is frequently absent. Stimpson states that each joint of the ambulatory feet, except the dactyli, is " dentigerous in the middle," a character not found in R. i&ood-masoni or in any other species of the genus that I have seen. The only specimens of this species in the Indian Museum are those described b}^ Alcock from the Andamans and from Port Canning near Calcutta. Fig. -Rlivncliopldx alcocki. sp. nov. Rhynchoplax alcocki, sp. nov. The carapace is subcircular, a little produced anteriorly and with its sides slightly flattened and nearly parallel. Its breadth is almost equal to its length, excluding the rostrum. The surface is hairy and sunken and the usual grooves are well defined. The entire margin is upturned and is continuous from side to side across the base of the rostrum. A sharp post-ocular tooth is vis- ible in dorsal view and behind it, on the margin itself, there is a blunt tooth corresponding to the foremost of those found in R. wood- masoni (text-fig. 4^). Below the margin near the base of the first pair of walking legs there is a huge tooth-like process directed for- wards, upwards and outwards. 254 Records of the Indian Museum. [Vol. XIII, The rostrum is composed of three narrow lobes with rounded extremities ; the median lobe is longer than the two others, and its apex is situated on a lower level. The antennules, when folded, are concealed beneath the rostrum ; at their base they are separated by a prominent septum. The epistome is of moderate length. As in R. wood-masoni the external maxillipedes are slender and do not nearly close the Fig. 4. — a-c, Rliy>icl!oplax ivood-masoni (Alcock). li-g, Rhynchoplax alcocki, sp. nov. a, d. — Rostrum, eye and antero-lateral margin of carapace. b, e.— Chela of male (denuded). c, f. — Abdomen of male. g. — Terminal part of dactylus of penultimate leg. buccal cavern. The ischium is produced at its inner distal angle and the merus is expanded antero-externally, partially concealing the exognath. The chelipedes in both sexes are stouter than the walking legs, the chelae of the adult male being particularly large. In the male the merus bears a conical tooth near the end of its lower margin and a series of some five large blunt teeth superiorl}'. igi/.] S. Kemp : Notes on Crustacea Decapoda. 255 The carpus is smooth. The chela is very greatly compressed and in adult males is little more than one and a half times as long as high. The palm in lateral view is nearly circular in outline (text- fig. 4^) and is slightly hollowed both internally and externally near the strongly compressed upper border. The lower border is convex and is keeled. The fingers gape very widely and meet only at their tips. The dactylus is almost twice the length of the upper border of the palm and bears in its basal third a single large tooth, in front of which a second smaller tooth is occasionally found. The fixed finger bears two large teeth in advance of those on the dactylus and one or two others, which are smaller, near the base. Near the apex, where they meet, the fingers are provided with four or five small interlocking teeth. In the female the teeth on the merus are obscure or altogether wanting and the chela is much narrower, fully twice as long as high; the fingers meet throughout their length and are armed with regularly spaced teeth. The walking legs are very slender ; those of the second pair are slightly the longest and are about two and a quarter times the length of the carapace and rostrum. The anterior border of the merus ends in a very obscure tooth. The dactyli are very slender and are curved ; close to the apex each is armed with a large recurved tooth (text-fig. 4g) and in front of this, in the last three pairs, there is a series of 8 to 11 smaller teeth, also recurved and extending over practically the whole length of the posterior margin. The chelipedes and legs are clothed with hair, which is particu- larly long and thick on the chela of the male. The sternum and abdomen are densely clothed with hair. The abdomen of the male resembles that of R. wood-masoni , but is slightly narrower. The terminal segment is scarcely longer than broad and is rounded at the apex (text-fig. 4/) ; the preceding por- tion is longer than broad, parallel-sided at the base and from the middle point onwards strongly narrowed. A large male is only 4*8 mm. in length from the tip of the rostrum to the posterior margin of the carapace. Ovigerous females are smaller, sometimes not more than 4 mm. long. The carapace of living specimens, when brushed clean, was of a dull purplish brown colour with groups of small whitish spots. R. alcocki is very closely allied to R. wood-masoni , Alcock, there being an almost exact resemblance between the two in the teeth on the merus of the male chelipede Apart from size, R. wood-masoni being much the larger form, the species may be distinguished by the following characters {cf. text-figs, ^a-c and 4d-f) :- R. wood-masoni , Alcock. R. alcocki, sp. nov. Carapace longer, its length Carapace shorter, its length excluding rostrum about one- 1 excluding rostrum scarcely great- tenth greater than its breadth. Two teeth on antero-lateral margin of carapace. er than its breadth. Only one tooth on antero- lateral margin of carapace. 256 Records of the Indian Museum. [Vol. XIII, Rostral teeth slender. Rostral teeth less slender. Cornea of eye proportionately Cornea of eye proportionately smaller. larger. Chela of adult male not great- Chela of adult male very great- ly compressed, more than twice ly compressed, much less than as long as high, lower edge of twice as long as high, lower palm rounded. edge of palm keeled. Fingers of chela of adult male Fingers of chela of adult male not gaping at base, armed with widely gaping at base, armed a regular series of teeth. with a very irregular series of teeth. Terminal segment of abdomen Terminal segment of abdo- of male apically pointed. men of male apically rounded. There are altogether about 100 specimens of this species in the Indian Museum. The greater number were found in Portu- guese India in September 1916 and were obtained in the Rachol river at the head of Mormugao Bay above Cortalim Point and in the Mandavi river at Nova Goa. Some of the specimens were dredged on a muddy bottom in water from i\ to 4I fathoms in depth, while others were found at Betim Point opposite Nova Goa, living on the posts of a jetty densely covered with Hydroid. All the specimens were found in brackish water, the specific gravity (corrected) varying from about looio to i'oo6o. There are also in the Museum a few specimens found by Dr. F. H. Gravely in Sep- tember 19 1 4 in the Cochin backwaters near Ernakulam. The types are from Portuguese India and bear the number 9735/10 Zool. Surv. Ind.^ Rhynchoplax octagonalis, sp. nov. The carapace, rostrum excluded, is a trifle broader than long and is distinctly octagonal in outline. The surface, in an oviger- ous female, is very little sunken; it is rather closely covered with short hairs and the usual grooves are well defined. The margin is continuous from side to side across the base of the rostrum and is entire, the blunt teeth found on the antero-lateral borders in the two preceding species being absent. On the side wall above the base of the first pair of walking legs there is a large and sharp procurved tooth (text-fig. 5). The rostrum in dorsal view is seen to consist of three sharp isolated spines, the lateral ones a little shorter than the median and directed obliquely outwards and upwards. The greater part of the eye can be seen from above, together with a small but sharp post-ocular tooth. The antennules when folded are not visible in dorsal view ; they are separated by a well-marked septum. The external max- illipedes resemble those of the preceding species. The chelipedes of the female are stouter than the legs. The merus does not bear any distinct teeth. The chela is not com- I9I7-] vS. Kemp : Notes on Crustacea Decapoda. 257 pressed and the fingers, which are longer than the palm, meet throughout their length when the claw is closed and hear a regular series of 5 or 6 teeth on their inner margins. The walking legs are not very slender ; those of the second pair are about twice the length of the carapace and rostrum. The anterior border of the merus in each pair ends in a prominent tooth. The dactylus of the first walking legs is unarmed; that of the three following pairs is provided with a stout recurved tooth close to the apex. The chelipedes bear scattered hairs; these also occur on the walking legs, which are, moreover, densely fringed on their posterior margins. F"iG. 5. — Rliynchoplax octagonalis, sp. now The species is described from a single ovigerous female, with carapace about 3'9 mm. in length. De Man's Elarnene filholi ^, from Noordwachter I. near Batavia, is without doubt a species of Rliynchoplax and resembles R. octag- onalis in the structure of the dactyli of the walking legs and in the position of the single tooth found on the lateral margin of the carapace. In the Javanese species, however, the eye is altogether concealed from above, the carapace and rostrum are quite differ- ent in form and the legs are much more slender. Miss Rathbun's R. coralicola''' from Singapore also possesses a single tooth at the 1 De Man, Archiv.f. Naturgesck., IJII, i, p. 386, pi. xvii, fig. 3 (1S87). •^ Rathbun, K.Danske Vid.Selsk, Skrift. (7), natiirvid. og math., V, p. 316, text -fig-. 5 (1910). ^:)< Records of the Indian Museum. [Vol. XIII, side of the carapace, but it is said to be antero-lateral in position In this species the dactyli are spinulous, thus differing conspicu- ously from those of R. filholi and R. octagonalis. The specimen was obtained at low water under stones among mangroves on Vareeg Islet in Mormugao Bay, Portuguese India, It bears the number 9740/10 ZooL Siirv. Ind. Rhynchoplax demeloi, sp. nov. The carapace is nearly circular; the breadth of its upper sur- face is about equal to its length, including the median rostral lobe. Fig. ().—Rhyi!clioplax demeloi, sp. no\'. The surface is greatly sunken and is covered with fine hairs that retain a quantity of mud; the usual grooves are deeply cut. The lateral border is entire, upturned, and continuous anteriorly across the base of the three rostral prominences ; it is obscurel}' angulate a short distance behind the eye. The tooth found in the three preceding species on the side wall of the carapace is absent. The three rostral prominences are exceedingly short. The median one is almost square, a little longer than broad, and is abruptly deflexed ; the other two are rounded, very much broader than long, and project straight forwards. The greater part of the cornea of the eye is visible in dorsal view. rgi;-] vS. Kemp : Notes on Crustacea Decapoda. 259 When viewed from below the median rostral lobe is seen to be longitudinally carinate and behind the eye there is a small post-ocular tooth which is altogether invis- ible from above (text-fig. 7). The antennules when folded are completel^^ con- cealed beneath the front; they are separated at their base by a strong septum. The epistorae is rather short. The external maxilli- , , . ^ 1 • -1 i. i.1 c Fig. 7. — Rhy nchoplax demeloi, ST>. nov. pedes are snnilar to those of >- i^- /. i^ j ^ i t- P alcocki Anterior part of carapace, seen from below. The chelipedes in both sexes are stouter than the walking legs and the chelae are much larger in the male than in the female. The merus and carpus are without teeth. The chela of the adult male (text-fig. 8) is about twice as long as high and is not carinate on its upper or lower margins. Except for a gap close to the base the fingers meet throughout their length; they are armed on their inner margins with 5 or 6 broad interlocking teeth that diminish in size from behind for- wards. The dactylus is nearly twice the length of the upper border of the palm. The chela of the female is similar, but more slender. In both sexes the chelipedes are covered with fine hairs ; on the outer surface of the palm of the male they are very long and dense, each retaining a quantity of mud. The second walking legs are slightly the longest and are a little more than two and a half times the length of the carapace. All the segments are exceptionally broad and the anterior border of the merus in each pair ends in a blunt tooth. The dactyli are quite flat, very broad, and only slightly curved; that of the last pair is only about four times as long as wide. The posterior margin is without any of the usual recurved teeth, in this respect differing from all other Indian species of the genus. The walking legs like all other parts of the body are covered with fine hairs which form a short but dense fringe ^^deiii7loi!'^s'p'^nov.^^ on the posterior borders of the last four seg- Abdomen of male. ments. The abdomen of the male is similar to that of R. alcocki and R. wood-masoni , but is narrower. The ultimate segment is bluntly Fig. 8. — Rhynchoplax demeloi, sp. nov. Chela of male (denuded). 26o Records of the Indian Museum. |Vol. XIII, pointed and is much longer than broad; the preceding portion, which, as in the other species, appears to comprise three fused segments, is obscurely grooved in the middle line ; its lateral margin is angulate near the middle and in front of this point is distinctly concave. The carapace of the largest specimen, an adult male, is about 4*4 mm. in length. The species is described from fourteen specimens, including a number of ovigerous females, obtained on the shores of the Mandavi river at Nova Goa in Portuguese India. They were found at low water under stones on a muddy bank. At the time they were taken the water in the river was brackish, the specific gravity being about I'ooio. With this species I have associated the name of Capt. Froilano de Melo, Director of the Bacteriological Laboratory of the Insti- tuto de Analises e Vacina at Nova Goa. I am greatly indebted to Capt. de Melo for the assistance he gave me during my visit to Portuguese India, especially for facilities for the investigation of the very interesting fauna of the Mandavi river. The types bear the number 9741/10 Zool. Surv. Ind. Rhynchoplax exiguus, sp. nov. The carapace is ovate and is widest a little behind the middle point; its upper surface, rostrum included, is a little longer than broad. In an adult female (text-fig. 10) the portions of the cara- pace above the bases of the first two pairs of walking legs are swollen, covered with stiff hairs and project beyond the upturned lateral margin of the carapace ; in males these parts are not vis- ible in dorsal view. There is no tooth or process above the base of the first walking legs or on the antero-lateral margin. The upper surface is a little sunken, covered with fine hairs, and with the usual grooves sharply defined. The rostrum is composed of three lobes set with stiff setae. The median lobe is depressed and longer than the other two ; in the adult female it is narrow and parallel- sided, in males broader at the base and triangular. The eye is unusually large; the entire cornea and a portion of the stalk is visible from above, together with a large and very conspicuous post-ocular tooth. The antennules when folded are completely concealed beneath the front : at their base they are separated by a well-marked septum. The epistome is comparatively long. The buccal cavern is of the usual form and is not nearly closed by the external maxilli- pedes. The merus in the latter appendage is a little longer than the ischium and expanded antero-externally, partially concealing the exopod The stalk of the exopod, as in R. naso, is long and projects a little beyond the endopod when the segments are nor- mally flexed. The chelipedes of male specimens (which are perhaps not full grown) resemble those of the female, the chela being only a little I9I7- S. Kemp : Noles on Crustacea Decapoda. 261 stouter than the walking legs. The merus is without teeth and the chela, though the palm is somewhat swollen, is comparatively long and slender. The fingers when closed meet throughout their length and are armed from base to apex with a regular series of 5 or 6 teeth. The walking legs are slender ; those of the second pair are about twice the length of the carapace and rostrum. The merus in each pair ends bluntly. The dactylus is long, slender and very strong!}'' curved ; the apex is finely pointed and on the posterior margin there are a number of exceptionally large recurved teeth. In the adult female there are 8 or 9 such teeth, distributed iG. 10. — Rliy)!clwpln.x exigiiiis, sp. nov. along the whole length of the dactylus; in smaller specimens they are less numerous — sometimes only 3 — and occur only in the distal half. The abdomen of the male is similar to that of R. demeloi. The 3rd, 4th and 5th segments form a single piece; the ultimate segment is triangular and a little broader than long. The species is described from ten specimens, most of which are exceedingly small. The adult female, which appears to have been captured soon after the eggs were discharged, is onh" 34 mm. in length from the tip of the rostrum to the hinder part of the carapace. The largest male, similarly measured, is only 28 mm. in length. 262 Records of the Indian Museum. [Vol. XIII, Rhynchoplax exiguus appears to be related to R. inachoides (Alcock), but is distinguished by the broader carapace, shorter rostral lobes, much shorter walking legs and larger dactylar teeth. The specimens were obtained by Dr. Annandale in the Tale Sap in Peninsular Siam. They were found on the mainland oppo- site the western end of Koh Yaw, living in lumps of turf that had fallen into the lake owing to the undermining of the bank. The water in the vicinity was brackish, the specific gravity being about 1*00625 (corrected). The types bear the number 9743/10 Zool. Surv. Ind. Rhynchoplax introvcrsus, sp. nov. The carapace is ovate and is widest behind its middle point; its greatest breadth slightly exceeds its length, rostrum included. The upper surface is much sunken ; in addition to the usual grooves, which are sharply demarcated, the branchial regions are traversed by a fine oblique line. There is an obscure anguktion on the anterolateral margin midway between the eye and the chelipedes, but there are no teeth in this position and no tooth or process above the base of the first walking legs. At first sight the antero-lateral and postero-lateral borders on each side appear to be discontinuous (tex-fig. iia). This, however, is due to the fact that the lateral walls of the branchial chamber project on either side and are reflected upwards, so as to form a crest which is actually higher than the true postero lateral border. This border is continued as a low ridge within and parallel to the branchial crest. The posterior margin is short, with a slight emargination on either side opposite the last leg. The rostrum is composed of three blunt processes, the median horizontal, parallel-sided and about twice as long as broad, the two others shorter, and project- ing obliquely upwards. Almost the whole of the eye is visible from above, together with a small post-ocular tooth. The antennules fold beneath the front and are separated at the base by a blunt longitudinal ridge. The epistome is long. The external maxillipedes are of the usual form; they gape widely in the middle line and the merus is a little longer than the ischium. The exognath is almost entirely exposed (text-fig. lib). The chelipedes are stout and clothed with fine hairs. The merus is without teeth. The chela is stout in the male, about two and a half times as long as broad, with the palm slightly swollen. The fingers are fully one and a half times as long as the upper border of the palm ; they meet throughout their length when the claw is closed and their inner margins bear five or six interlocking teeth. The walking legs are slender ; the second pair is about two and a third times as long as the carapace and rostrum. The merus in all four pairs bears a small tooth at the distal end of the upper border. The dactylus is moderately curved and is armed 1917.3 S. Kemp : Notes on Crustacea Decapoda. 263 S a '' 111 "^ ^ (U C <^ o 1 £ 13 CO ■'^^^:3^ 264 Records of the Indian Museum. [Vol, XIII, with 6 to 8 small rather widely separated teeth that occupy the greater part of the length of the posterior border. In the abdomen of the male (text-fig. ric) the penultimate piece is of the usual form, but is very strongly narrowed distally. The terminal segment is exceptionally' long, its length being nearly twice its basal breadth. The species is described from two males, in one of which — much the larger of the two — the carapace is 5*4 mm. in length. In most respects R. introversus is intermediate between R. exiguus and R. inachoides , but differs from both in the form of the postero-lateral border of the carapace. It resembles R. inachoides in the character of the dactyli of the walking legs, but the legs themselves are shorter, the rostral lobes shorter and blunter and the carapace broader. The specimens were found by Dr. Annandale in the Tai Hu Lake in the Kiangsu Province of China. The larger individual was found off the mouth of the Tong Dong Ding Creek and the smaller at the mouth of the Moo Too Creek. Both were dredged in water about 2 metres in depth. Dr. Annandale noted that the speci- mens were pale buff in colour with brown markings on the cara- pace somewhat like a fleur-de-lys. The species is remarkable in that it was obtained in pure fresh water far beyond the reach of tidal influence. A consider- able number of Hymenosomatidae have been found in localities where the salinity is low and some appear to be able to exist in water that is quite fresh during a portion of the year. But the only species hitherto recorded from permanently fresh water is Halicarcinus lacustris (Chilton),' which has even been found 3,000 ft. above sea-level. The type specimen, the larger of the two individuals, bears the number 9730/10 Zool. Surv. Ind. Rhynchoplax inachoides (Alcock). lyod. Hymenicus inachoides Alcock, 'Joitrn. Asiat, Soc. Bengal. I. XIX, p. 388, and (1902) Illnsf. Zool. ' hivcstigator.' pi. Ixix, fig", i. I have little to add to Alcock's description of this species. The post-ocular denticle is clearly visible in dorsal view ; the fingers of the chela of the male meet throughout their length and are armed with a regular series of teeth ; the abdomen in the same sex is narrow and similar to that of R. demeloi. The only known specimen is the male described by Alcock and found by Wood- Mason, along with R. wood-tnasoni , at Port Canning near Calcutta On a recent tour in this locality I tried to obtain further specimens but was unable to find either species. ' ['"or references see p. 247. I9I7-] S. Kp:mp : Notes on Crustacea Decapoda. 265 Rhynchoplax nasalis, sp. nov. The carapace is almost exactly circular and is nearly or quite as broad as long, excluding the rostrum. The surface is sunken, covered with hair, and with the grooves sharply defined. The border is entire, upturned, and is continuous from side to side across the base of the rostrum. The rostrum differs from that of all other species in the genus in the suppression of the lateral processes; it consists merely of a single horizontal plate, more than twice as long as wide, pointed at the apex and bordered with hairs (text-fig. 12). hi(.. I-'. Rhviuhoplax iiasal/'s. sp. nov The basal segment of the antennular peduncle and the whole of the eye are visible in dorsal view. There is no post-ocular tooth and no trace of an inter-antennular septum. The epistome is of moderate length. The external maxillipedes are similar to those of the preceding species, -but the merus is larger in proportion to the ischium and, when normally folded, the stalk of the exognath extends much beyond the distal end of the merus. The chelae are swollen in both sexes and are much stouter than the walking legs ; they are only a trifle larger in the male than in the female. The distal end of the lower border of the merus ends in a stout tooth, but the segment is not otherwise 266 Records of Ihe Indian Museum. [Vol. XIII, armed. The carpus is smooth. Fig. 1,3. — Rhynciwplax nasalis, sp. nov Chela of male (denuded). The chela is not greatly com- pressed and is not cari- nate either above or be- low. In the male it is little more than twice as long as deep, the dactyl- us being about one and a half times the length of the upper border of the palm. When the claw is closed the fingers meet throughout their length ; they are armed with a regular series of six blunt behind forwards (text-fig. V\G. 14. — Rhvncltoplax nasal is, sp. nov. Tip of dactylus of penult- imate walking leg. teeth which diminish in size from 13). The second pair of walking legs is about two and a half times the length of the carapace and rostrum, the last pair about twice the length. All the segments are very slender and there is no tooth at the end of the upper border of the merus. The dactyli are curved ; that of the first pair is simple, while in the remaining three pairs there is a single small recurved tooth situated some distance behind the apex (text fig. 14). The abdomen of the male (text-fig. 15) is abnormally broad, the length of the two ultimate pieces being equal to the breadth of the penultimate. The lateral margin of the latter is abruptly narrowed anteriorly and bears a large and curiously formed tubercle near its distal end. The ultimate segment is broader than long, broadly rounded apically and with ele- vated lateral margins. In the female the abdomen is broad, but the ultimate segment is ra- ther more triangular than in other species. The entire animal is covered with hairs, which are compara- tively long on the chelipedes and legs. The specimens when caught were covered with a dense coating of mud which was only removed with great difficulty. When denuded the crabs were ivory white in colour, the eggs of the female being reddish orange. The length of the carapace and rostrum in an adult male is 4'4 mm., an ovigerous female is exactly the same size. rWi. 15. — RlryncJiopla.x nasali^ sp. nov. Ab-^.omen of male. I9I7.J S. Kemp : Notes on Crustacea Decapoda. 267 The species is described from fifteen specimens, most of which are exceedingly small. They were dredged in the Bidyadhari river near Chingrighatta on the outskirts of Calcutta in October and December 1914. They were found in very foul water which gave specific gravities of i"0045 and i-oo6o on the two occasions on which the locality was visited. The types bear the number 9744/10 ZooL Surv. Ind. Genus Hymcnicoides, nov. The carapace is nearly circular in outline, sunken, with the usual grooves sharply defined and the lateral margins upturned. The rostrum is altogether absent. The epistome is of moderate length and the buccal cavern is bounded anteriorly by a sharp ridge. The external maxillipedes are slender, gaping widely in the middle line and leaving visible parts of the underlying appendages. Fig. 16. • — Hymenicoides carteri, gen. et sp. nov. Anterior part of carapace, seen from below. The nierus is much longer than the ischium and is more than two and a half times as long as wide ; the dactylus is styliform and of abnormal length, reaching the posterior limit of the buccal cavern when normally flexed (text-fig. 16). The chelipedes in both sexes are stouter than the legs. In the abdomen of the male the terminal segment is trilobate and the sutures of all the segments are distinct. This genus is related to Rliynchoplax and Halicarcimis, but differs from both in the absence of the rostrum and in the great length of the dactylus of the external maxillipedes. It resembles Rhynchoplax in the slenderness of the basal segments of the exter- nal maxillipedes and Halicarcinus in having all the segments of the male abdomen distinct. Type and only known species, — Hymenicoides carteri, sp. nov. 268 Records of the Indian Museum. [Vol. XIII, Hymenicoides carteri, sp. nov. The carapace is almost circular, emarginate at the base of the last legs and with the posterior border short; it is broader than long in the proportion of 21 to 20. The upper surface is greatly depressed, with the grooves well defined, and is closely covered with minute hairs. The margin is entire and upturned; anter- iorly and antero-laterally it forms an even curve and bears in the middle of the front a small tuft of hairs. The rostrum is entirely absent. The basal segment of the antennule and the greater part of the eve are visible in dorsal view. Ki(i. \-/ .—- Hviiit'i/icoK^i'i' I'lf'^d't ■ "^]>- "(i\' At their bases the antennules are separated by a sharp for- wardly directed tooth : there is no post-ocular tooth. The epis- tome is of moderate length. The buccal cavern is somewhat nar- rowed anteriorly; its lateral borders are rather strongly curved and, as in the genus Rhynchoplax , its anterior and posterior edges are curved inwards (text-fig. 16). On the sternum behind the bases of the external maxillipedes there is a semicircular ridge, concave anteriorly, which bears a fringe of long hairs. The curious struc- ture of the external maxillipedes has been referred to in the generic description. There are long hairs on the inner borders and outer surface of the ischium and merus and on both inner and outer borders of the dactylus. The exognath bears a long fiagellum and, I9I7-I vS. Kemp : Notes on Crustacea Decapoda. 269 I'll.. i>S. — J/ \'/iici//coi(/cs ciirferi. ^p. no\ Chela of large male, external view. except for a small portion at the base of the stalk, is entirely con« cealed from view. The chelipedes are greatly swollen in both sexes ; the chelae of the male are much larger than those of the female. The outer border of the merus bears a conspicuous tooth in front of its middle point. On the inner side of the carpus there is a longitudinal vtdge which is furnished with a fringe of long hairs. The chela of the male (text-fig. 18) is less than one and a half times as long as high. There are sharp keels on both upper and lower borders of the palm, the latter being continued to the tip of the immobile finger. These keels like that on the carpus are fringed with long hairs. The inner surface of the palm is con- vex and the outer face bears a huge protuberance (text- fig. 19), only well developed in very large males, which culminates in a short crest not far form the finger cleft. The fingers are stout and in large individuals meet only at the tips. The dactylus bears two large blunt teeth in its basal half and the fixed finger two smaller ones placed just behind them; nearer the tip each finger bears four or five teeth. The dactylus is fully one and a half times the length of the upper border of the palm and is obscurely ridged dorsally. The chela of the female is similar to that of the male, but is more slender and shows practically no trace of the large protuberance on the palm. Except for the fringes of hair already mentioned the chelipede bears only a few fine and scattered setae. The second walking legs are a little longer than the first and third and are about three times the length of the carapace; the last pair is only two-thirds the length of the second. The anterior border of the merus in all four l-)airs terminates in a hhint tooth. The dactyli are slender and Kkt. \().— Hv i.ieiiuiiiiles cartci-i, s|j. Chela of large male, dorsal view. i'K.. 211, — Hvnienicoides carteri, sp. now Dactylu.s of peuultiuiate walking leg. 270 Records of the I ndiaii Museum. [Vol. XIII, curved. Close to the apex each bears a large recurved tooth, behind which a number of smaller teeth are usually found. On the first pair of legs there are generally not more than one or two such teeth; on the other legs they are more numerous (text- fig. 20) and often extend from the base to the large subterminal tooth; the maximum number observed is eleven. There are fine hairs on all the segments and a fringe on the posterior margins of the propodus and dactylus. In large males the hairs on the propodus and dactylus of the first legs are very long and numerous, forming dense tufts that retain a great quantity of mud. The sternum and abdomen are thickly beset with hairs. In the abdomen of the male (text-fig. 21) all the sutures are distinct. The lateral margins are markedly sinu- ous, the widest point being at the junction of the fourth and fifth segments; the ultimate segment is trilobed terminally and is much broader than the distal width of the sixth. The carapace of the largest speci- men, a male, is 57 mm. in length. The species is described from twenty-two specimens found on the banks of the R. Hughli at Sibpur, near Calcutta, in January 1917, by Dr. Annandale and myself. They were obtained in timber bored by Teredo {Xylotria dunlopi) lying be- tween tide-marks. The water at the time they were found was almost or quite fresh at all states of the tide, but is doubtless brackish later in the 3^ear. There are also in the collection two specimens, both small, collected by Mr, T. Southwell near Khulna in the Gangetic delta in August 1915. With this species I have associated the name of Dr. H. G. Carter, Officiating Director of the Botanical Survey of India, to whom I am indebted for facilities for collecting at Sibpur. The types, which are from this locality, bear the number 9746/10 Zool. Surv. Ind. Genus Elamena, Milne-Edwards. 1837. Elamena, Milne- Edwards, Hist. nat. Crust., II, p. 33. [Not Elamene, Milne- Edwards, Ann. Sci. nat., Zool. (3), XX, p. 223 (1853); nor Elamene, A. Milne-Edwards, Nouv. Arch. Mus. Paris, IX, p. 321 (1873^-] 1900. Elamena, Alcock, Journ. Asiat. Soc. Bengal, LXIX, p. 385 (not the synonymy). The carapace is oval, triangular or polygonal, greatly de - pressed, and sometimes lamellar. The upper surface is flat or con- cave, without the usual sharp-cut grooves, and the lateral margins Fig. 21. — Hymenicoides carteri, sp. nov. Abdomen of male. 1 917'] S. Kemp : Notes on Crustacea Decapoda. 271 may or may not be upturned. The rostrum is broadly truncate or triangular, never tridentate or trilobate. The epistome is long, sometimes very long and is separated by a ridge from the floor of the buccal cavern. The external maxillipedes are broad and completely close the buccal cavern; the ischium is longer, some- times much longer than the raerus, and the dactylus is, as usual, short. The chelipedes of the male may or may not be' stouter than the walking legs. In the abdomen of the male the 3rd, 4th and 5th segments are fused and the sutures between them ob- literated. Judging from the Indian species, this genus, here described sensu lato, dififers from all other Hymenosomatidae in the absence of the customary grooves on the upper surface of the carapace. In the character of the male abdomen it resembles Rhynchoplax , but differs from that genus in the form of the rostrum and ex- ternal maxillipedes. Milne-Edwards' Trigonoflax is, at most, a sub- genus of Elamena [v. infra, p. 274). Six species of Elamena, s.l. are now known from the Indian coasts, all being represented in the Indian Museum with the ex- ception of E. gracilis, Borradaile. I have not been able to satisfy myself regarding the position of this species and have, in con- sequence, omitted it from the following key. It is perhaps inter- mediate between Elamena, s.s. and Trigonoplax. I. Margin of carapace upturned; rostrum with a vertical keel on its lower surface and in frontal view T-shaped; chelipedes of male greatly swollen, much stouter than legs [dactylus of walking legs apically triunguicu- late] = Elamena s.s, A. Carapace as broad or broader than long ' ; rostrum broad and squarely truncate ; a small post-ocular tooth present, but not visible from above ... ... ... ... E. truncata B. Carapace longer than broad ' ; rostrum prom- inent, triangular ; no post-ocular tooth ... E. sindensis, (Stimpson). sinden Alcock. II. Margin of carapace not upturned; rostrum at most with a small tooth at base of lower surface, not T -shaped in frontal view ; chelipedes of male slender, not stouter than walking legs. = subgen. Trigono- plax. A. Rostrum parallel-sided at base ; a strong post- ocular tooth visible in dorsal view ; dactj'li of walking legs armed in their distal third with a series of small teeth [carapace about as long as broad] ... ... ... ... E. (T.) cimex, B. Rostrum strictly triangular, its sides convergent from base to apex ; no post-ocular tooth visible in dorsal view ; dactyli of walking legs triungui- culate at apex. I. Carapace longer than broad,' its antero- lateral margins curved and not longer than postero-latsral ; rostrum fiat above; a post-ocular tooth visible only from K cmp. ' Rostrinn included. 272 Records of the Indian Museum. Vol. XIII, below ; 2nd walking legs less than 2A times length of carapace I ... Carapace broader than long, ' its antero- lateral margins straight and very much longer than postero-lateral , rostrum hollowed above ; no post-ocular tooth ; 2nd walking legs more than t, times length of carapace ' Elatnena truncata (Stimpson). A". (7".> xaviert, sp. nov. E. ( T. ) It iigu iforni ■ is, de Haan. 1.S58. Trigonoplax tyitncata, Stimpson, Proc. Aaiif. .Vat. Set. Pliiliidelt^liia. X, , P- 109 [55]. 1873. hlamene tvtmcata, A. Milne-Kdwards, Nouv. Arch. Miis. Paris, IX, P- 323- 1893. Elamene truncata, Henderson, Trails, l.inn. Soc, Zool. (2), V, p. 395. 1900. Elaniena truncata, Alcock, Joiirn. Asiat. Soc. Bengal, LXIX, p. 386. 1906. Elamena truncata, Baker, Trans. Roy. .Soc. S. Atistralia, XXX, p. i \2, pi. li, figs. 2, 2a-d. 1907. Trigonoplax truncata, Stimpson, Smiths. Misc. Coll., XLIX, p. 14(1. There does not appear to be any reason to doubt that the descriptions given by vStimpson and A. Milne-Edwards refer to the biG. 22. — Elamena truncata (Stimpson) ?. same species, though the specimens examined are from widely distant localities. \. Milne-Edwards, however, seems to have Koslrum included. igiy-] S. Kemp : Notes on Crustacea Decapoda. 273 been unaware of the existence of Stimpson's account, for he makes no reference to it and his description is headed ' ' Elamene truncata (nov. sp.)." That both authors have used the same specific name is presumably due to a remarkable coincidence. Alcock was able to examine only a single example of this species, but two others have since been obtained ; unfortunately all three specimens are females. Both Stimpson and A. Milne- Edwards note that the chelae of the male are inflated and there is consequently little doubt that the species belongs to Elamena, sensu stricto. As in E, sindensis, the margins of the carapace are up- turned and the front, or rostrum, bears on its underside a deep vertical keel, giving it a T-shaped appearance in facial view The abdomen of the male, according to Baker's description and figure, consists of five pieces, whereas only four are to be found in all the males of other species of Elamena and Trigonoplax that I have seen. From the figure it looks as if only the 3rd and 4th segments were fused in E. truncata, in place of the 3rd, 4th and 5th. A fresh examination of males is desirable, In the Indian specimens the carapace is proportionately broader than in those described by Baker, the breadth being decidedly greater than the length. The front, or rostrum is squarely truncate, not rounded as described by Henderson. Be- hind the base of the swollen eyestalk there is a small post-ocular tooth (not shown in Baker's figure) which is altogether invis- ible in dorsal view. The chela of the female is little stouter than the walking legs ; the fingers gape slisrhtly when closed and are ,,- ,. 7^;; \-, , , arm.ed on their inner margins ^ (Stimpson). with minute teeth and short Terminal segment of abdomen of hairs. The dactylus in all four female, pairs of walking legs is triungui- culate at the apex. The anterior border of the ultimate segment of the abdomen of the female is strongly sinuous (text-fig. 23). Alcock examined a single individual of this species, obtained at the Nicobars. The two additional specimens were found at Port Blair in the Andamans under a block of coral exposed at low water; the carapace of the larger is 4-8 mm. in lengtli. When alive the carapace was brown in colour with four cream-coloured marks' as described by Stimpson. There is also in the Indian Museum a female specimen of E. truncata, unfortunately with all the legs missing, received manj^ years ago from the Godeffroy Museum under the name Elamena qtioyi. It bears the label " Samoa and Viti Is." The species appears to be one of wide Indo-pacific distribution. In addition to the above records it is known from the Ceylon coast (Henderson), the Loo Choo Is. (Stimpson), New Caledonia (A. Milne- ' Shown by dotted lines in text-fie;-, 22. 2^4 Records of the Indian Museum. [Vol. XIII, Edwards) and S. Australia (Baker). Lenz's record from Zanzibar ' is erroneous, the specimens described belonging in all probability to Desmarest's E. mathaei. Elamena sindensis, Alcock. iQGO. Elamena sindeiisis, Alcock, Journ. Asiat. Soc. Bengal, LXIX, p. 386 and (:902) /llusf. Zool. 'Investigator,' pi. Ixiv, fig. 3. This species is still represented in the Indian Museum only by the specimens described by Alcock from Karachi. In addition to particulars noted by Alcock, it may be mentioned that the dactylus of the male chela bears a low blunt tooth near the base, the margin of both fingers being otherwise finely serrate. The dactylus of the walking legs is apically triunguiculate. The abdomen of the male is rather broadly triangular, its sides being lightly sinuous, with the 3rd, 4th and 5th somites fused. The terminal segment of the abdomen of the female resembles that of E. truncata. Subgenus Trigonoplax, Milne- Edwards. 1853. Trigonoplax, Milne- Edwards, A>in. Set. nat., Zool. (3), XX, p. 224. 1900. Trigonoplax (subgenus of Elamena), Alcock, 'Journ, Asiat. Soc. Ben- gal, LXIX, p. 386. I agree with Alcock that Trigonoplax can only be regarded as a subgenus of Elamena. E. {Trigonoplax) xavieri, which is des- cribed below, still further emphasizes the close relation between the two groups, the inter-antennular septum being a prominent plate, exactly as in Elamena, s.s. In the subgenus the carapace is flatter than in Elamena, with its margins scarcely at all upturned, and the chelipedes are similar in the two sexes and not appreciably stouter than the walking legs. In the two species of Elamena that I have seen, the ros- trum is T-shaped when viewed from in front, owing to the presence of a large vertical plate on its lower side ; this structure, which is quite distinct from the septum between the bases of the anten- nules, is either absent in Trigonoplax or is represented by a tooth situated far behind the anterior margin. These distinctions are slight and Trigonoplax in course of time will probably find a place in the synonymy of Elamena. Borra- daile's E. gracilis appears from the description and figure to be intermediate between the two groups here recognised. Elamena (Trigonoplax) cimcx, Kemp. 1915. Elamena {Trigonoplax) cimex, Kemp, Mem. Ind. Miis., V, p. 216, text-figs. 4, 5, pi. xii, fig. 3. The species differs from all related forms in the areolation of the carapace; the gastric, cardiac and hepatic regions are each 1 Lenz, Ahhandl. Senck. naturf. Ges. Frankfurt. XXVI I, p. 367, pi. xlviii, figs. 15 a,b { IQ02'). igiy.] S. Kemp : Notes on Crustacea Decapoda. 275 slightly tumid and are separated by broad and shallow furrows. In this respect there is perhaps some approach to the condition found in Halicarcinus and Rhynchoplax , but there is no trace of the finely cut grooves that are conspicuous in those genera. The tooth on the lower surface of the rostrum, which is well marked in E. (T.) xavieri and slightly indicated in E. (T.) tinguif omits , is in this species altogether absent. The dactyli of the walking legs bear a series of small teeth and are not apically triunguiculate as in all other Indian species of Elamena. Elamena (Trigonoplax) cimex has hitherto been found only in the Chilka Lake, on the Orissa coast of the Bay of Bengal. The specimens were dredged in fresh water, but in a situation subject to great seasonal variation in salinity. Fig. 24. — ElameiKi {Trigunoplax) xavieri. sp. nov. Elamena (Trigonoplax) xavieri, sp. nov. The carapace closely resembles that of E.{T.) cimex in outline, but the antero-lateral borders are more strongly arched ; its length is to its breadth as 13 to 12. There are shallow emarginations opposite the bases of the last two legs. The surface is quite flat, the regions not being defined in any way, and is altogether devoid of hairs; the margins are not upturned. The rostrum is a large triangular plate and is flat above ; its margins are slightly convex and converge regularly from the base to the apex; they are not parallel at the proximal end as in E (T.) cimex. On the under side, 276 Records of the Indian Museum. [Vol. XIII, near the base, the rostrum bears a sharp forwardly directed tooth (text-fig. 25). The eyes and a small portion of the eyestalks extend beyond the carapace. A small post- ocular tooth may be seen when the carapace is viewed from beneath, but in dorsal view is altogether invisible. The antennules are separated at the base by a well-defined septum, much more distinct than in E. (T.) unguiformis. Theepistomeislong. The anterior border of the buccal cavern is convex on either side of the mid- dle line. In the outer maxillipedes the ischium is much longer than the merus and is separated from it by a very oblique suture. The exognath bears a long flagellum and its basal part, though largely overlapped by the endopod, is visible throughout its length. The chelipedes are alike in the two sexes and are not appreci- ably stouter than the walking legs ; they are about as long as the carapace and rostrum. The merus is without teeth and the merus, carpus and palm are slightly roughened and bear very fine and exceedingly short hairs. The chela is about four and a half times as long as high and the fingers are equal in length with the palm. Towards their apices the fingers are slightly inturned and on the nmer face of the chela are somewhat hollowed longitudinally. When the claw is closed the fingers meet throughout their length ; Fig. 2^.—Elamena (T.) xavieri, sp. nov. Anterior part of carapace seen from below. Pig. 26. — Elameiia {Trigonoplax) xavieri, sp. nov, Chela of male. each being provided with a series of small recurved teeth extend- ing from the base to the apex (text-fig. 26). The second pair of walking legs is slightly longer than the first or third, about two and a third times the length of the carapace ; the fourth is much the shortest, about one and three quarter times the length of the carapace. All the segments except the dactylus 1917-] S. Kemp : Notes on Crustacea Decapoda. 277 are roughened like the cheUpedes and are thinly clothed with very fine hairs. In all four pairs the merus and carpus end in a strong tooth. The dactyli are slender and curved; the inner margin is densely fringed with hair and bears near the apex two stout recurved teeth, as in E. (T.) unguiformis (text- fig. 27). The ultimate segment of the abdomen of the male is triangular, a little broader than long and with a pair of rather conspicuous p^^ 2i~^^^^EUnnena pits near its base; proximally it is a little {T. )'. \ av'i e r i, ■~,-^. no\-. wider than the contracted distal end of the Tip of dactylus of last preceding portion. The distal margin of the walking leg. abdomen of the female is slightly sinuous, as in E. (T.) unguiformis ; in E. (T.) cimex it is more convex. The carapace of a large female is 9°2 mm. in length ; males are smaller, not exceeding 7*5 mm. In living specimens the carapace is dark brown or slate- coloured, with pale antero-lateral margins and, as in E. truncata, a pair of elongated pale blotches project inwards and forwards from the bases of the last two pairs of legs. In general appearance this species bears much resemblance to E. (T.) cimex: but it is in reality more closely allied to E. (T.) nn- giiiformis. This is clearly shown by the presence of the inter- antennular septum and the tooth on the lower surface of the rostrum (both of which are in fact better defined than in E. [T .) un- guiformis) . and it is also evident in the structure of the dactylus of the walking legs. The species is described from three males and three females obtained in the Mandavi river, opposite the town of Nova Goa in Portuguese India, They were dredged at a depth of about ro feet on a muddy bottom in places where the current ran swiftly. The specific gravity of the water in which they were taken was very low, about I'ooio (corrected). In the specific name allusion is made to St, Francis Xavier, whose remains lie interred at Goa, not far from the place where the specimens were obtained. The types bear the number 9750/10 Zool. Surv. Ind. Elamena (Trigonoplax) unguiformis, de Haan. 1839. Ocypode {Elamene) unguiformis, de Haan, in Siebold's Fauna 'ifapo- iiica, Crust., p. 75, pi. xxix, fig. i ; pi. H. igoo. Elamena {Trigonoplax) unguiformis, Alcock, fourn. Asiat. Soc. Ben- |-a/, LXIX, p. 357. 1907. Trigonoplax unguiformis, de Man, Trans. Linn. Soc, Zool. (2), IX, p. 396. 191=;. Trigonoplax unguiformis, Parisi, Atti Soc. Ital. Set. )\ai., l.IV, p. 281. Other references are given by Alcock. This well-known species differs conspicuously from the two preceding forms in the shape of the carapace, the antero-lateral 278 Records of the Indian Museum. VOL. XIII, borders being proportionately very much longer and quite straight (text-fig. 28). The rostrum is hollowed above and bears near the proximal end of its lower surface a low ridge in place of the tooth found in E. {T.) xavieri. The epistome is extremely large, almost as long as the external maxillipedes. The fingers of the chelae are P^IG. 28. — Elamena [Trigonoplax) uuguifov) Outline of carapace. dc Haan. furnished with minute teeth and the dactylus of the walking legs is triunguiculate. The abdomen of the male is broad at the base and narrow at the apex, the lateral margms being concave ; the 3rd, 4th and 5th segments are fused. McCuUoch ' appears to be right in regarding his South Australian speci- mens as a distinct variety of this spe- cies. In Indian specimens the ros- trum is not nearly so long, nor the dactyli of the walking legs so broad as shown in his illustration. I give here, for comparison, outline figures of the carapace and dactylus of the first leg. The species is not uncommon at Port Blair in the Andamans, living among weeds in pure sea water at depths of 2 to 8 fathoms. In life, specimens are of a dull semitransparent brownish or greenish tint, without any conspicuous markings. The species is known from the Gulf of Martaban (Henderson) and from numerous localities in Japan (de Haan, Ortmann, de Man, Parisi). KiG, 29. — Elamena {T!) iDigni- furmis, de Haan. Dactylus of first walking leg. i TrigouopLax iiiiguiformis var. longii-ostris, McCulloch, Rec. AKstraliaii Mus., VII, p. 5Q, pi. xii. fig. 3 (1908). I9I7-] S. Kemp : Notes on Crustacea Decapoda. 279 Elamena gracilis, Borradaile. 1906. Elamena gracilis. Borradaile, in Gardiner's Faun. Geog. Mahiive and Laccadive AvchipeL, II, p. 6S4, text-fig. 122 a, b. 191 1. Elamena gracilis, Rathbun, Yrans. Linn. Soc. Zool . (21, Xl\', p. 242. I have seen no specimens of this species and do not know whether it should be referred to Elamena, s.s., or to Trigonoplax. Judging from the figtire the lateral margins of the carapace are up- turned ; but the chelae are described as slender and apparently do not show ail}' sexual differences. There is no mention of a vertical keel on the lower face of the rostrum. In the form of the carapace E. gracilis differs conspicuously from any Indian species of the genus that I have seen. It was described by Borradaile from Minikoi and Male Atoll and has since been recorded bv Miss Rathbun from Coetivy. XVII. NOTES ON CRUSTACEA DECAPODA IN THE INDIAN MUSEUM. XI. Atyidae of the genus Paratya {=Xiphocaridina). By Stanley Kemp, B.A., Superintendent, Zoological Survey of India. Bouvier has shown that the West Indian Xiphocaris elongata (Guerin) differs in several important structural characters from the species, previously referred to the same genus , found in Eastern Asia, Australia and New Zealand and has proposed for the latter the generic n?ira.Q Xiphocaridina. But Miers in 1882, when recording certain Japanese Atyids as Atyephyra? coinpressa, noted that the species was probably to be distinguished generically from Brito- Capello's Atyaephyra by the presence of exopods on all five thoracic legs '; and he suggested for the Japanese form the generic name Paratya. There can be no doubt that Miers' specimens are generically identical with those on which Bouvier based his Xipho- caridina with the result that the latter name, by far the more ap- propriate of the two, must lapse. Genus Paratya, Miers. 1868. .4tye/}hyra, von Martens, Arch./. Natiirgesch., XXXIV, p. 51 (in part : not Atyaephyra, Brito-Capello). 1880. Miersia, Kingsley, Proc. Acad. Sci. Philadelpliia, 1879, p. 416 (in part). 2 1882. Paratya, Miers, Ann. Mag. Nat. Hist. (5) IX, p. 194. 1895. Xiphocaris, Ortmann, Proc. Acad. Sci. Philadelpliia, 1894, p. 400 (in part). 1905. Xiphocaris, Bouvier, Ann. Sci. France Belgiqne, XXXIX, p. 60 (in 1909. Xiphocaridina, Bouvier, Comptes Rendiis Acad. Sci., Paris, p. 1729. 1912. Xiphocaridina, Kemp, Rec. hid. Mus., VII, p. 113. Only two species which can be referred to the genus Paratya have hitherto been recognised, viz. Paratya compressa (de Haan), described from Japan and since recorded from Korea, Flores, Aus- tralia and Norfolk I. and P. ciirvirostris (Heller) from New Zea- land, Chatham I, and Upper Assam. 1 Miers was evidently unaware that von Martens in 1872 {Arcli.f. Natiir- gesch., XXXVIII, i, p. 139) had founded the genus Xiphocaris on this very character. Xiphocaris, however, was based on specimens from the West Indies and, as Bouvier has shown, is distinjj^uished from the Pacific genus by the greater number of branchiae and other important characters. ^ The type of this genus is Risso's Ephyra pelagica, probably a Hoplophorid. 294 Recofds of the Indian Museum. [Vol. XIII, In the collection recently made by Dr. Aiinandale in the Far East there are series of P. compressa from several localities in Japan. On examination, the specimens were found to fall into two well-marked races, one inhabiting the north-eastern portions of the main island, while the other is apparently restricted to the south-western parts, the upper limit of its distribution being Lake Biwa and its vicinity. This rather unexpected discovery led me to make an examination of all the Paratya preserved in the In- dian Museum, and I find as a result that there has been a great deal of misapprehension regarding the taxonomy and distribution of the species. The Indian Museum is fortunately well supplied with material; including Dr. Annandale's collection, specimens are available from seven localities in Japan, from Sydney in New South Wales, from lyake Torrens in S. Australia (as well as a sample from ''S. Australian waters"), from both east and west sides of Norfolk I., from two localities in New Zealand and from two in Upper Assam. Examination of this extensive material leads me to conclude (i) that the true Paratya compressa is restricted to Japan, possibl}'' extending into Korea ; in the main island of the former country it is represented by two well-marked races; (ii) that the Aus- tralian form is to be distingusihed specifically from the Japanese and is represented in Norfolk I. by a race which differs from it in characters of at least subspecific value; and (iii) that the form recorded from New Zealand and Upper Assam is distinct from any of the others. The five forms examined may be distinguished by the follow- ing characteristics : — Key to the species and subspecies of Paratya. I. Propodus of 3rd and 5th peraeopods, in both sexes, less than three times as long as dactylus,' dactylus of 3rd pair with 19 to 30 spines,"^ the number very rarely falling to 18 [propodus of 3rd and 4th pairs ex- panded distally in male, the dilated portion bearing numerous spines]. A. Rostrum with 16 to 25 dorsal teeth ; hindmost tooth situated on carapace or immediately above orbital notch ... ... ..P. conipyessa Cde Haan). B. Rostrum with 7 to iS dorsal teeth; proximal part of rostrum unarmed, -no tooth on carapace or above orbital notch ... ... F. compressa, subsp. improvisa, nov. II. Propodus of 3rd and 5th peraeopods, in females,'' more than three times as long as dactylus ; dactylus of 3rd pair usually with 6 to 13 spines, the number occasionally rising, in males only, to 18. ' The extreme length of the dactylus, terminal spine included. ■^ Including the terminal spine. 2 The character is also valid for males of P. ausfralie/isis and its subspecies ; in males of P. cttrvirostris the proportion occasionally falls as low as 2"5. 1917-] S. Kemp : Notes on Crustacea Decapoda. 295 A. Upper border of rostrum with 10 to 17 irregu- larly disposed teeth, forming at least three distinct groups ; propodus of 3rd and 4th legs expanded distally in males, the dilated portion bearing numerous spines ... ... P. ciirvirostyis (Heller). B. L'pper border of rostrum with 19 to 32 teeth, forming an uninterrupted series ; 3rd and 4th legs of male not modified. 1. Carpus of ist peraeopods twice or more than twice as long as broad ; propodus of 5th peraeopods less than four times as long as dactylus ; dactyli of 3rd and 5th peiaeopods at least three times as long as broad,' dactylus of 3rd per- aeopod with 9 to 13 spines ... P. aiistraliensis, sp. nov. 2. Carpus of 1st peraeopods less than twice as long as broad ; propodus of 5th per- aeopods, at least in females, more than four times as long as dactylus ; dactyli of 3rd and 5th peraeopods less than three times as long as broad ; dactylus of 3rd peraeopod with 6 to 8, rarely 9 spines ... ... ... P. aiistniliensis, subsp. norfolk- eiisis, now It is probable that the size of the eggs will afford a valuable criterion in specific and subspecific differentiation ; but unfortu- nately the collection contains ovigerous females only of P. curviros- tris and of P. compressa subsp. improvisa. It will be noticed that in three of the five recognised forms the third and fourth peraeopods of the male are modified, the propodus being conspicuously dilated towards its distal end and armed on the posterior margin of the expanded part with a great number of short spines. Very similar sexual differences are met with in Atyaephyra, a genus that has a circum-Mediterranean distribution and is also one of the more primitive genera of the family. In males of Atyaephyra desmaresti, as Barrois has shown,* the third and fourth legs are modified on precisely the same lines as in Paratya; but, strangely enough, the segment concerned is not the propodus, but the merus. That sexual modifications of the third and fourth legs should be entirely absent in the forms of Paratya from Australia and Norfolk I. is very curious. Males are unfortunately scarce in ray material from these localities and examination of further speci- mens is therefore desirable. In no case, however, have I found the slightest trace of modification, though the character is well marked in much smaller specimens from Japan. Caiman* has noticed sexual differences in the length of the spines on the third and fourth legs in Limnocaridina siimlis and L. socius from Lake Tanganyika, while in other species of the same I Excluding all spines, both terminal and lateral. ^ Barrois, Rev. Biol. Nord. France, V, p. 124, fig. 2 (1892). 3 Caiman, Proc. Zool. Soc. London. 1906, p. 195. 296 Records of the Indian Museum. [Vol. XIII, genus no such distinction was to be found. It seems probable, therefore, that in this genus, as in Paratya, the existence of sexual modifications in the thoracic legs is a specific character. In Xipho- caris, the most primitive of all the Atyidae, these sexual differ- ences do not exist.' Bouvier,* in his account of the races of Atyaephyra desmaresti, found that distinctive characters were afforded by the structure of the endopodite of the first pleopod of the male. In the genus Paratya the appendage is similar in outline in all the forms and the differences that exist in the spinulation appear to be of less im- portance than those derived from other parts. All the species and subspecies examined agree in the posses- sion of a supraorbital spine. The carpus of the first peraeopod is deeply excavate in front, that of the second pair less markedly so. Exopods are found on all the thoracic legs, but there are no arthrobranchs above the bases of any of these limbs. The outer uropod agrees with that of Xiphocaris in bearing only a single movable spinule in place of the series found in most genera of the family. The telson bears two, less commonly three pairs of dorsal spines and is provided at the apex with eight or ten spinules A synopsis of the numbers of rostral teeth in the different forms is given on p. 297. In the descriptions which follow I have referred only to the characters that show racial or specific differences. Paratya compressa (de Haan) sensu stricto. 1849. '^- EpJiyra compressa, de Haan, in Siebold's Faiiiin Japouica, Crust., p. 186, pi. xlvi, fig. 7. 1880. Miersia compressa, Kingsle}', Proc. Acad. Sci. Philadelphia, 1879, p. 416. 1902. Xiphocaris compressa, Rathbun, Proc. U.S. Nat. Mtis., XXVI, p. 49 (? part only). 1905. Xiphocaris compressa, Bouvier, Bull. Sci. France Belgique, XXXIX, p. 62 (part only ; not fig. 1, p. 61). 1914. Xiphocaridina compressa, Balss., Abliaiidl. matb.-phys. Klassc K. Bayer. Akad. Wiss., Suppi. Bd. II, Abt. 10, p. 23 (part only). In this form the rostrum always reaches beyond the anten- nular peduncle, extending almost to, or a little beyond the apex of the antennal scale. On its upper border it is armed with 16 to 25 (usually 17 to 24) teeth, forming an uninterrupted series from the base to the apex. The hindmost dorsal tooth is either situated on the carapace or is placed immediately above the posterior limit of the orbit ; in a few cases two posterior teeth are on the carapace. The lower border bears in the middle of its length from i to 6 teeth, most commonl}'^ i to 3. The lateral process of the antennular peduncle extends a little beyond the end of the basal segment. ' This statement is based on an examination of a few specimens from Havana in Cuba, preserved in tlie Indian Museum ' Bouvier, Bull. Mus. d'/fisf. iiat. Paris, 1913, p. 65. igij-l S. Kemp : Notes on Crustacea Decapoda. Dorsal teeth. 297 Number NUxVIBER OF SPECIMENS. of P. compressa. P. atistraliensis. 1 teeth. typical subsp. ciirvirosti'is. typical subsp. form. impvovisa. form. norfolkensis. 7 \ 8 5 9 4 10 5 2 II 1 [ 5 12 1 8 i^i U) >; U 3 2 15 3 T 16 2 2 ■? 17 .T I 18 6 1 19 14 I 20 7 2[ 19 22 8 ,1 , — 24 2 2 -5 I 2 26 1 7 -/ 28 I 29 4 3'» 3 0 ,•) ' ~ 32 I 2 Ventrai. teeth. Number of teeth. Number of specimens. P. compyessa. P. ciiyvii'ostris. P. australiensis. typical form. subsp. improvisa. typical form . subsp. norfolkensis. I 13 3 2 3 4 5 6 "7 21 2 2 4 3 3 25 14 4 5 17 7 I I 3 2 1 8 I I 9 10 II 12 1 13 14 298 Records of the Indian Museum. [Vol. XIIL In the first peraeopods (text fig. la) the carpus is compara- tively slender, from 2*2 to 2-5 times as long as its greatest breadth ; rarely in young specimens the proportion falls as low as i-8. The chela is about a third longer than the carpus and its length is usual- ly about one-third the width of the palm. The carpus of the second pair (text fig. 16) is from 6"o to yi times as long as broad. The dactylus of the third peraeopods (text-figs, ic, d) is long and slender; the propodus is only from 2"-i to 2"5 times its length. Excluding the spines its length is from 37 to 4"5 times its breadth. The dactylar spines vary in number from 19 to 22, very rarely 18. In the fifth peraeopods (text figs, le, /) the propodus is also from 21 to 2 "5 times as long as the dact3dus ; the latter segment bears from 43 to 69 spinules, excluding which it is from 4-2 to 4-8 times as long as broad. In the male the propodus of the third and fourth peraeopods is a little dilated towards the distal end and the terminal third of Fici. I. — I'di-afya compressa ( de Haap). a. First peraeopod. d. Dactylus of third peraeopod. /). Second peraeopod. e. Fifth peraeopod. c. Third peraeopod of male. /. Dactylus of fifth peraeopod. the posterior margin is armed with numerous close-set spines (text- fig, ic). In the specimens I have seen these sexual modifications are much less conspicuous than in the larger individuals belonging to the subsp improvisa. None of the specimens examined bear eggs ; the largest is 23 mm. in total length, De Haan's figure of this species is unusuall}^ poor, but except for the fact that the carpus of the second legs is stated to be in- distinctly annulate, the description agrees very well with the speci- mens I have examined. According to de Haan there are 20 to 24 teeth on the upper border of the rostrum. The typical form of P. compressa is represented in the Indian Museum by a great number of specimens collected by Dr. Annan- dale in Komatsu Lake near the eastern shore of Lake Biwa and from the Ogura and Yodo ponds near Kyoto : there are also a few examples from L. Biwa itself. All specimens from localities situ- I9I7-] S. Kemp : Notes on Crustacea Decapoda. 299 ated further to the north-east belong to the subspecies improvisa and it appears, therefore, that the northern distributional limit of the typical form is somewhere in the vicinity of Lake Biwa. The specimens recorded by Miss Rathbun from the latter locality un- doubtedly belong to the t^^pical form and this is perhaps also the case with the solitary individuals which she examined from Tsus- hima I. and from Fusan in Korea. If m}^ views on the distribu- tion are correct, Balss' examples from Koitogawa in Kadzuza prov. are to be referred to the subsp. improvisa, while those recorded from Okayama belong to the typical race. Balss notes that in the latter individuals the eggs are 0'63 mm. in length and 0-40 mm. in breadth. Dr. Annandale noted that the species was abundant among weeds or dense vegetation at Komatsu and in pools and back- waters round Lake Biwa ; in the lake itself it was much scarcer. Living specimens showed no definite markings, but were dotted more or less profusely with small pigment cells. The fingers of the chelae were tinged with orange brown. The Temnocephaloid worm Caridinicola was present in the gill-chambers of a large pro- portion of the individuals examined at Komatsu. subsp. improvisa, nov 1868. Atyephyi'u conipressa, von Martens, Arch. f. Nafurgescli., XXXIV, i, p. 51, pi. i, figs. 4a-c. 1882. Atyepliyi'a ? compi-essa, Miers, Ann. Mag. Nat. Hist. (5,, IX, p. 193. ? iSgo. Miersia conipressa, Ortmann, Zool. Jahrb., Syst., V, p. 464. ? 1902. Xiphocaris conipressa, Doflein, AbhandL niath.-pliys. Klasse K. Bayer. Akad. Wiss., XXI, p. 632. This subspecies is distinguished from the typical form almost entirely by the dentition of the rostrum. The rostrum reaches to. h\(i. 2. — Paratva conipressa subsp. improvisa now d. Dactylus of third peraeopod of female. )erae<)nod. n. First peraeopod. b. Second peraeopod. c. Third peraeopod of female. <;. Fifth peraeopod. /. Dactylus of fifth peraeopod. or a little beyond the antennal scale and bears on its upper margin an uninterrupted series of 7 to 18 (usually 8 to 15) teeth. The 300 Records of the Indian Museum. [Vol. XIII, proximal part of the rostrum is altogether unarmed ; the hind- most tooth of the series is placed above the cornea, when the eye is directed straight forwards, or is in advance of this point. On the lower border there are from i to 4 teeth, usually 2 or 3. The proportionate measurements of the legs are much the same as in the typical form. In the first pair (text-fig. 2a) the carpus is from 2T to 27 times as long as broad and in the second (text-fig. 2b) from 56 to 6-3 times. The propodus of the third pair (text-figs. 2c, d) is from 2*4 to 2"j times the length of the dactylus, the length of the latter segment, spines excluded, being from 3-3 to 40 times its breadth. In the fifth pair (text-figs. 2e, /) the propodus is from 2*4 to (in one instance only) 2"9 times as long as the dactylus, the latter segment, spines excluded, being from 4*o to 47 times as long as broad. The dactylar spines seem to be rather more numerous than in the typical form ; in tlie third pair there are from 24 to 30 and in the fifth from 71 to 92. In large males the third and fourth peraeopods show an extreme degree of sexual modification (text-fig. 3). The propodus is very strongly expanded distal- ly, so much so that the seg- ment is less than 5 times as long as broad, whereas it is nearly 9 times as long as broad in females. The anterior mar- gin is concave, while the poste- rior is convex and is furnished with numerous spinules in the distal two thirds of its length. The, dactylus is also modified ; it is more than 5 times as long as wide and is widest near the distal end; the spines are dis- tinctly recurved and the termi- nal one is not larger than the others. The subspecies appears to be rather larger than the typical form, reaching a maximum length of 36 mm. The eggs vary from 063 to 070 mm. in length and from 0-43 to 0*46 mm. in breadth. In this case I believe that the character of the rostrum affords a valid basis for racial distinction ; among fifty specimens of the subspecies I have not been able to find a single individual that resembles the typical form. The specimens examined are from the lagoon Kasumi-ga-ura in Hikachi province, collected by Dr. N. Annandale; from Tokio, collected by Hilgendorf (Berlin Mus.) ; from Lake Haruna, near Ikao, at an altitude of about 3000 ft., collected by Dr. K. Nakazawa and from Lake Suwa, in the Shinano province, at an altitude of 2660 ft,, collected by Dr. T. Kawamura. FiCx. 3. ^ubsp. -Paratya compressn proviso, nov. Third peraeopod of adult male with dacty- lus further enlarged. 1917-] S. Kemp : Notes on Crustacea Decapoda. 301 The specimens from Yokohama described by von Martens be- long, as is clearly shown by the figure, to the subspecies impro- visa and this is also true of those from Tokio examined by Miers, the rostrum bearing only from 7 to 14 dorsal teeth. From these facts it may be concluded that the subspecies is found only in the north-eastern parts of the main island of Japan and, if this is true, the specimens recorded by Ortmann from Tokio, by Doflein from Yokohama and by Balss from Koitcgawa in Kadzuza province are probably to be referred to the subspecies. This is no doubt also the case with the material used by Ishikawa in his account of the development of the species.* The types are from Lake Haruna and bear the number 9679/10 in the register of the Zoological Survey of India. Paratya curvirostris (Heller). 1862. Caridi)ia curvirostris, Heller, \'erhaiidl. sool.-hot. Ges. IF/V«, XII, P- 525- 1865. Caridiua curvirostris, Heller, \^oy. ' Novara,' Crust., p. 105. 1876. Caridiua curvirostris, Miers, Cat. N. Zealand Crust., p. 78. 187U. Leander fluviatilis, Thomson, Trans. N.Z. hist. XI, 187S, p. 2,^1, pi. X, fig. A 2. 1903. Xipliocaris curvirostris, Thomson, Trans. Linn. Soc, Zool. (2), VIH, y. 447- pl- xxix, figs. 2-13. 1906. Xiphocaris curvirostris, Chilton, Proc. Zool. .Soc. London, p. 703. 1909. Xiplwcaridina fluviatilis, Honw'ier, Cojnptes rendus Acad. .Sci. Paris, p. 1728. 1912. Xiplwcaridina curvirostris, Kemp, Rec. Ind. Mus , \TI, p. 113. In this species'' the rostrum reaches to or a little beyond the apex of the antennal scale and is armed above with from 10 to 17 teeth. These teeth do not form an uninterrupted series, as in all other species of Paratya, but are separated, usually quite dis- tinctly, into three groups. The hindmost group consists of 2 or 3 teeth, all of which are on the carapace behind the orbital notch; the second group is composed of 4 to 8 teeth, situated in the basal half of the rostral length; the third group is placed just behind the apex and comprises 3 to 7 teeth. In most cases i or 2 solitary teeth are to be found between the second and third groups. On the lower margin there are from 3 to 8 teeth, usually 4 to 6. The teeth are larger than is customary and are rather widely separated, extending on to the distal third of the rostral length. The lateral process of the antennular peduncle reaches to the middle of the second segment. The carpus of the first peraeopods (text-fig. 4a) is from 17 to 2"4 times as long as broad; it is decidedly more slender in males than in females. That of the second peraeopods (text-fig. 46) is from 5*0 to 67 times as long as broad. The propodus of the third peraeopods (text-figs. 4c, /) is from 2*5 to 3*9 times the length of C^f 1 Ishikawa, Quart. Journ. Microsc. Sci., XXV, p. 391 (1885). ^ The information here given is mostly abstracted from my paper of 1912, supplemented by a number of fresh observations. 302 Records of the Indian Museum. [Vol. XIII, the dactylus, the former segment being proportionately shorter in males. Excluding the spines the dactylus is 3'4 or 3'5 times as long as broad in females, rather narrower in males. In females the spines (the terminal one included) are from 9 to ri in number, very rarely 8; in males they are more numerous, from 13 to 17, rarely 18. In the fifth peraeopods (text-figs. 4g, h) the propodus is from 3*1 to 37 times the length of the dact3dus. The latter segment bears from 46 to 71 spinules, excluding which it is from 3"2 to 3*7 times as long as broad. In males the propodus of the third and fourth peraeopods is modified much as in P. compressa (text-figs. 45, /). The dactylus is slightly abnormal in form, but is without recurved spines and the propodus does not seem to attain as extreme a development as in large males of P. compressa subsp. improvisa. In very old females additional spinules are sometimes found on the propodi of Fig. 4. — Paratya ciirvirostn's (Heller). a. First peraeopod. e. Third peraeopod of adult male. b. Second peraeopod. /. Dactylus further enlarged. c. Third peraeopod of old female. g. Fifth peraeopod. d. Dactylus further enlarged. h. Dactylus further enlarged. the third and fourth peraeopods (text-fig. 4c), thus resembling adult males. The eggs are from 0'40 to o'45 mm. in length and from o'25 to 0*26 mm. in breadth. Large specimens reach a total length of 42 mm. P. curvirostris is known from both north and south islands of New Zealand and from Upper Assam. It has been recorded by Chilton from the Chatham Is. In the Indian Museum it is repre- sented b}' a number of specimens from the River Avon at Christ- church (Chas. Chilton coll.) and by one from the Shag River (Paris Mus.), both localities being in the southern island. There are also twenty- four specimens from Tezpur, in the Darrang district of Assam, and three from the Manipur Hills, all collected by Col. H. H. Godwin-Austen. The views here advanced on the taxonomy of the species of Paratya, make it more than ever difficult to offer any explanation of the curious distribution of this species ; the new observations I9I7J S. Kemp : Notes on Crustacea Decapoda. 303 indicate that the methods I adopted in 1912, in comparing the specimens from Assam with those from New Zealand were reliable and that had specific differences existed they would infallibly have been detected. If the record from Assam were based on speci- mens from one locality I would have rejected it as untrustworthy, but the fact that samples exist from two distinct places renders it improbable that any mistake can have arisen. Paratya australicnsis, sp. nov. iSg.].. Miersia compressa, Ortmann, Jenaische Denkschvift, VIII (=:Semon"s Zool. Forscliniigsreis. in Anstvalien etc., V), p. lo. 1903. Xiphocaris compressa, Thomson, Trans. Linn. Soc. Zool. (2) V^III, p. 449 (part). 1905. Xiphocaris compressa, Bouvier, Ann. Sci. France Belgique, XXXIX. fig. 1, p. 61. Hitherto the Australian representative of the genus Paratya has been considered to be specifically identical with that from Fig. 5. a. First peraeopod. b. Second peraeopod. c. Third peraeopod. -Parafya aitstraliensis, sp. nov. d. Dactylus of third peraeopod. e. Fifth peraeopod. /. Dactylus of fifth peraeopod. Japan, but judging from the specimens in the Indian Museum it is undoubtedly distinct. Three samples of Australian specimens have been examined, all of which differ in certain well-marked features from the Japanese examples. They also differ rather considerably inter se and it appears not unlikely that recognisable races exist in different parts of the Australian continent. As types of P. australiensis 1 have selected a number of specimens from Clyde, near Sydney in New South Wales. The rostrum in P. australiensis varies considerably in length, extending to the end of the antennular peduncle or far beyond the apex of the antennal scale, sometimes (in specimens from Sydney) reaching beyond the latter point by as much as one quarter its length. On its upper border it bears an uninterrupted series of 304 Records of the Indian Museum. |Vol. XIII, ig to 32 teeth' (usually 22 to 31) of which i or 2, rarely 3, are placed on the carapace behind the orbital notch. On the lower border there are from i to 14 teeth (usually 2 to 9) ; the distal third of the lower margin is in most cases unar med. The lateral process of the antennular peduncle sometimes reaches only to the end of the basal segment, in other cases to about one-third the length of the second segment. The carpus of the first peraeopods is comparatively slender, from 2"o (Lake Torrens) to 2*9 times as long as broad and is some- times, as shown in text- fig, 5^, much less deeply excavate than in other species. The carpus of the second pair (text-fig. 56) is from 5*8 to 7"5 times as long as broad. The propodus of the third pair (text-fig. 5c) is from 3*5 to 4*0^ times as long as the dactylus (ter- minal spine included). The dactylus (text-fig. 5^) bears from 9 to 13 spines, usually 9 to ir; excluding these its length is from 3*0 to 3*6 times its breadth. In the fifth peraeopods (text-figs. $e, f) the propodus is from 30 to (rarely) 3-8 times the length of the dactylus. The latter segment, spinules excluded, is ver^^ variable in form, from 3*3 to nearly 5 ^ times as long as wide. The spinules vary in number from 28 to 82.* The third and fourth legs of the male show no signs of sexual modification. No ovigerous females are present in the material examined. The largest of the vSydney specimens is 27 mm. in length ; an in- dividual from "S. Australian waters" is rather larger, about 31 mm. The specimens examined are from Clj^'de, near Sj^dney, from Lake Torrens in S. Australia and from " S. Australian waters." The first of these samples includes the type specimens ^ which bear the number 7590-2/10 in the Zoological Survey register. The specimens recorded by Ortmann from Burnett in Queensland, by Bouvier from Melbourne and by Thomson from Victoria and New South Wales are presumably to be referred to this species. The identit}^ of von Martens' examples from Adenare near Flores is quite uncertain. The material I have examined shows an unusually great range of variation and it is possible, as noted above, that more than one definable race of the species exists in Australia ; the specimens in my hands are, however, not sufficiently numerous to afford evi- dence that this is really the case. ^ The rostral formulae in the three samples are as follows : — In 12 specs, from Sydney "^.1! ■ in 6 specs, from I ,ake Torrens ?^^^ : in 5 specs, from " S. Austra- ian waters " ' j"^- . 2 In a female from Lake Torrens. 3 3-3 to 4'o in most cases. The specimen with a proportion of nearly- 5 is perhaps an abnormality. * From 28 to 65 in the Sydney specimens. 6 Owing to a very unfortunate accident the types have baen destroyed since the description was drawn up. The only portions of them that remain are cer- tain appendages mounted on slides for microscopic examination. igiy.] S. Kemp : Notes on Crustacea Decapoda. 305 subsp. norfolkensis, nov. 1903. Xiphocai-is coiiipressa. Thomson, Trans, l^iiin. Soc. Zool. (2) V'lII, p. 4+9 (part). 1907. Xipliocaris coiiipressa, Cirant and M cC uUoch, Proc. Linn. Soc. .V.^.H ., XXXII, p. 156. Specimens from both sides of Norfolk I., collected b}'' Messrs. Laing, are in the Indian Museum. Examples from the east side of the island are smaller than those from the west, but do not appear to be distinguished by any other constant character. The material examined does not bear out Grant and McCulloch's state- ment that the rostrum is proportionately shorter in specimens from the east side. The rostrum varies greatly in length and is frequently very Fio. 0. — Paratya (Uisfral ieiisis subsp. norfolkensis, nov. a. First peraeopod. d. Dactylus of third peraeopod. b. Second peraeopod. Third peraeopod. e. Fifth peraeopod. /. Dactyhis of fifth perasopod. much shorter than in any other race of Paratya. In specimens from the west side it reaches, in one instance, only to the end of the second antennular segment, in others almost or quite to the end of the peduncle and in one individual a little beyond the apex of the scale. Among those from the east side the rostrum in one case reaches barely beyond the end of the first antennular seg- ment, in others to the end of the second segment, to the end of the peduncle or a trifle beyond the apex of the scale. The upper border bears from 21 to 32 teeth,' forming an uninterrupted series from the base to the apex. The hindmost 2 to 5 teeth * are placed on the carapace. On the lower border there are from 3 to S teeth ' which almost always extend on to the distal third of the rostral length and not infrequently reach almost to the apex. ^ According to Thomson's observations liie leelh vary from 17 lo 34 above and from 2 to 9 below. '^ 2 or 3, rarely 4, in specimens from tlie east side ; 4, rarely 5, in those from the west. 3o6 Records of the Indian Museum. [Vol. XIII, 1917.] The lateral process of the antennular peduncle reaches to the end of the basal segment, or as far as the middle of the second segment. The carpus of the first peraeopods (text-fig. da) is much broader than in any other race or species of Paratya that I have seen ; in females it is only from i'3 to i*6 times as long as broad and in males from vy to 1*9 times. It is very deeply excavate anteriorly. The carpus of the second peraeopods (text-fig. 6h) is from 4-2 to 4*9 times as long as broad. In the third peraeopods (text-figs. 6c, d) the propodus, in females, is from 4*3 to 5*2 times as long as the dactylus, from 37 to 3*9 times in males. Excluding the spines the dactylus is only from 2*i to 2*7 times as long as broad, being rather more slender in males than in females. The spines are less nu- merous than in the typical form; they vary from 6 to 8, the number occasionally rising to 9 in males. In the fifth peraeopods (text-figs. 6gj /) the propodus is from 4' 2 to 4*4 times as long as the dactylus, the proportion in males rarely falling to 3*9. The dact}'- lus, excluding the spinules, is from 2*4 to 2'8 times as long as broad. The spinules are from 35 to 43 in number and differ con- spicuously from those of the typical form in one particular. In the Australian race, as in all other members of the genus save the present one, the spinules towards the apex increase successively in size by even gradations. In the Norfolk I. form the spinules are fine and regular throughout the greater part of the dactylar length, but close behind the tip there is a sudden break in con- tinuity, the three, less commonly two terminal teeth being vastly larger than the adjacent members of the series (text-fig. 6/). As in the typical form the third and fourth legs of the male show no signs of sexual modification. There are no ovigerous females among the specimens examined. Examples from the west side of the island reach a length of 32 mm. ; those from the east side do not exceed 18 mm. It appears to me not improbable that the Norfolk I. form deserves rank as a full species, but further work on the Australian races is necessary before its precise position can be determined. The types are from the west side of the island and bear the number 8500/10 in the register of the Zoological Survey of India. Author's Copy, RECORDS of the INDIAN MUSEUM Vol. XIV. FAUNA OF THE INLE LAKE. Crustacea Decapoda of the Inle Lake Basin. By STANLEY KEMP. CALCUTTA JUNE 1918, CRUSTACEA DECAPODA OF THE INLE LAKE BASIN. By Stanley Kemp, B.A., Superintendent, Zooloijical Survr/j of India. Plates XXIV, XXV. The collection of Decapod Crustacea made by Dr. Amiandale and Dr. F. H. Gravely in and near the Tnle Lake in the Southern Shan States comprises representatives of the following seven species : — PoTA^rONIDAE. Potawon {Pofawon) hrowneanuw, sj). nov. Potamon [Potamon] acanthicum, sp. nov. Potawon {Potamon) cartohafes, sp. nov. Palaemonidae. Palaemon naso, sp. nov. Palaemon Jiendersoni, de Man. Atyidae. Caridina annandalei\ sp. nov. Caridina weberi. prox. var. siDnatrensis, de Man. That five of these species should prove to be undescribed is remark- able, and particularly that three of the nev; forms should be Potamoni- dae, for the Indian sjiecies of this family have been described by Alcock from a great abundance of material, including the late Dr. John Ander- son's collection from Upper Burma. The general results derived from an examination of the Decapod fauna of the district agree with those obtained in other groups, especially the Fishes and the Mollusca : — the fauna is in a large measure endemic and, in consideration of the past history of the region (see the introduct- ion to this volume, p. 6), must be regarded as including a large proportion of peculiar species some of which once spread over a much greater area. Like other groups of aquatic animals the Decapods of the district appear for the most part to be specialized rather than primitive. Of the two prawns hitherto known, Palaemon Jiendersoni has a range extending from the Darjiling district along the Eastern Himalayas to Burma ; it is also abundant in the hills of Assam, south of the Brahma- putra. The Burmese specimens differ slightly from those found in the Himalayan regions and in Assam and possibly represent a distinct race. De Man's Caridina weheri, described from Flores, Celebes and Saleyer is represented in the Shan States by a form similar in some respects to the var. snmatrensis from the east coast of Sumatra, but in all j:>rob- ability subspecificallv distinct. Races of this speci(>s. sonu^ of which undoubtedly deserve nominal recognition, occur over the whole of the Indian Empire, but until it ha.s been ])ossible to make a detailed study I 82 Records of ilie Indian Museum. [Yol. XIV, of material from mariy different localities, it seems best to postpone further consideration of the point. The affinities of the undescribed species are with Burmese and Assam- ese forms. To this there is, however, one exception, viz., Ptdacmon naso, a species which perhaps differs from the others in being primitive. The relationships of this prawn are by no means clear ; the unusually weak development of the second legs suggests alliance with such forms as P. lamarrei, Milne-Edwards, and P. lanchesferi, de Man, both of which are found in coastal districts. Caridina annandalei seems to be the representative in the Salween watershed of a curious little group of species in which the number of epipods is diminished. The only other two species of this group at present known inhabit streams at the base of the Eastern Himalayas. Of the Potamonidae P. broumeanum is allied to P. andersonianum (Wood-Mason), a species of wide distribution in the mountains of Burma and Yunnan. P. curtohates is related to P. pealianum (Wood-Mason), hitherto known only from N. E. Assam and from the Kakhyen Hills on the frontiers of Burma and China. Potamon acanthicum is a very remarkable form, quite unlike any other Burmese species. It appears, however, to be a highly specialized offshoot of the same stock as P. (mdcrsonianum. The species is interest- ing in its approximation to the subgenus Acanthotelphusa. According to the observations made by Dr. Annandale Decapod Crustacea are of greater economic importance in the Shan States than in most inland parts of India. All the species mentioned in this paper are used as food. In the State of Yawngwhe, in which the Inle Lake is situated, the Potamonidae are caught by the hill tribes and brought down into the village bazaars, in which Palaemon naso is sometimes also on sale. The former are sold roasted, the latter raw and often alive. The Atyidae, however, in spite of their small size, are of greater con- sequence, for very large quantities are collected both for local consump- tion and for export to other parts of Burma and even, it is said, to Siam. They are captured, chiefly as the water sinks in autumn, in small traps of basket-Avork and in flat baskets inserted under floating vegetation ; dried in the sun on bamboo mats and packed in large deep baskets, each of which is two men's load. They are carried by porters over the He-Ho pass to the railway and on pack mules inland to the Siamese frontier. One of the baskets used in their capture is figured on Plate vii. fig. 1 of this volume, while one of those in which they are stored and transjiorted is shown in the photograph reproduced as fig. 3, pi. xliii, in vol. Y of the Memoirs of the Asiatic Society of Bengal. Family POTAMONIDAE. Potamon (Potamon) browneanum, sp. nov. Plate xxiv. figs. 1, 2. This species is closely allied to Potamon (P.) andersonianum (Wood- Mason), but differs fiom it and from all its varieties in a number of well- marked features. 1918.] Stanlfa' Kemp : Decapoda of the Inle Lake. 83 The length of the carapace is about four-fifths its greatest breadth, its outline in dorsal view bein,u' much the same as in P. andersonianiim ; it is, however, much deeper, the depth beinti almost or quite three-fifths of the length. The greater depth is, in the main, due to the fact that the u})per surface between the epigastric crests and the posterior margin is decidedly convex, whereas it is Cjuite flat in typical P. andersonianum and almost flat in the var. ramioonense of that species (pi. xxiv, figs. 1, 2). The areolation of the upper surface is faint. The mesogastric areola is defined anteriorly by the bifurcation of the frontal groove and post- eriorly by the cervical groove ; its antero-lateral boundaries are al- together invisible. The cervical groove is deeply graven posteriorly and is distinct where it cuts the post-orbital crests, but between these two limits is very broad and shallow. Traces also exist of a groove (very distinct in P. andersonianum) on the epibranchial region, more or less parallel with the cervical groove. The greater part of the upper surface of the carapace is smooth, but in some specimens fine rugae are visible behind the epigastric and post-orbital crests. The epibranchial regions are strongly tuberculous, the tubercles being fewer, larger and sharper than in the related species. The side-walls bear oblique rugae which extend over the postero-lateral border and are visible from above. The epigastric and post-orbital crests are similar to those of P. ander- sonianum ; the former are obliquely truncate anteriorly and extend forwards in advance of a line joining the posterior borders of the orbits. The post-orbital crests are straight, undermined and irregularly crenulate. The surface of the front is coarsely granular ; its margin, like the upper border of the orbit, is crenulate and in dorsal view is very deeply Fig. 1. — Potanion (Potamon) browneunum, sp. nov. a. Outline of left side of carapace. b. Third maxillipede. c. Abdomen of male. bilobed. This last character will at once distinguish it from P. ander- sonianum or any of its varieties. The external orbital tooth is sharp and is separated from the serrate lower border of the orbit by a deep notch. I 2 84 Records: of I lie Intlian Miiseuvi. [YoL. XIV, The antpro-latoi'al liordor (toxt-fi!i\ ^a) is sharper and nuich more strontily reflected u])\vards tlian in P. andersonianum. It is separated from the coarsely oranular e])ibraneliial reoion by a deep smooth croove and its margin, instead of being serrulate, is spiniilose. At the posterior end of the border the sj)inules are small and closely packed ; anteriorly they are larger and more widely spaced ; the foremost is a large epi- branchial tooth which frequently beai's one or more granules on its edges. The antennular fossae and epistome are much as in the relat(»d form. The ischium of the outer maxillipedes (text-fig. \h) bears the usual groove ; the merus is as long as broad and is rounded in outline, rather than irregularly hexagonal as in typical specimens of P. ander- sonianum. The chelae are more or less of a size. The merus is similar to that of P. andersonianum, but the granulation is much crisper, the serrated margin being spinulose and the tooth near the distal end of the inner face becoming a sharp spine with accessory spinules at the base. The carpus is smoother above and is not, or not appreciably, umbilicate. On the upper surface of the palm there are some small and inconspicuous tubercles which extend a little way down the outer face ; the lower half of the outer surface is quite smooth. The fingers are more compressed than in the allied species and the teeth on their inner margins are much larger. The dactylus is grooved in the usual way and bears some sharp tubercles at the base of its upper surface. The Avalking legs are rather more slender than in P. andersonianum, but the anterior margin of the projiodus, as in hat species, is double- edged. The propodus of the penultimate leg is two and a half times, and that of the last leg twice as long as broad. In the abdomen of the male (text-fig. Ic) the length of the sixth segment is rather more than half its greatest breadth ; the seventh is a little broader than long. The carapace in six specimens yields the following measurements (in mm.). Sex s (? s s ? ? Length 41-8 .38-.5 30-2 30-5 38-7 33-0 Breadth .'52-.3 49-3 40-.'^ 38-2 49-2 4o0 Depth 25-3 235 21-0 17-7 220 18-0 The eggs borne by an ovigerous female are very large, about 3 mm. in diameter. Potamon hroumeanum may be distinguished from P. andersonianum (i) by its more convex upper surface, (ii) by the incompletely circum- scribed mesogastric areola, (iii) by the deeply bilobed front, (iv) by the granulation, which, except on the chelae, is everywhere crisper — parti- cularly on the antero-lateral borders of the carapace, the lower borders of the orbits and the merus of the chelipedes, (v) by the smooth outer surface of the chelae and larger dactylar teeth and (vi) by the more slender propodus of the walking legs. From P. pealianum (Wood- Mason), which it resembles in the convexity of the upper surface of the carapace, P. hroumeanum is distinguished by the stronger curve and sharj)er spinulation of the antero-lateral borders, by the more deeply bilol)"d front and the nnich less conspicuous frontal eminences. 1918.] Stanley Kemp: Decapodd of the Inle Lake. 85 Dr. Aiuiandale has uivoii iiic the foUowiiiu notes on the cohjuration of living specimens of this species. " Dorsal surface dark ohve ; upper surface of walking legs marbled with a paler shade. Tips of fingers of large claw and of large spine on same a2Jpendages white. Frontal and orbital margins reddish brown. Ventral surface of body yellowish white."' The species,' which is named after Mr. C. E. Browne, Political Adviser in the Yawnghwe State, is ap2)arently not unconnnon in the vicinity of the Inle Lake, but was not found in the lake itself. The specimens are from the He-Ho stream, 3800 ft., from the Hsin Dawng stream, near Yawnghwe, 3300 ft., and from the neighbourhood of the Ngot bat cave, 4000 ft. They were found in February and March 1917, under stones at the edge of running water and in holes in the banks of small streams. The type specimens are from the He-Ho stream and bear the number 9763/10, Zoo/. Surv. Ind. Potamon (Potamon) acanthicum, sp. nov. Plate xxiv, hgs. 3, 4. The carapace is short and broad, the length being a little less than three-c|uarters the greatest depth. The distance in the middle line between the cervical groove and the posterior border is conspicuously less than the distance between the cervical groove and the epigastric crests. The upper surface is strongly convex in both directions, the depth being about half the greatest breadth (pi. xxiv, figs. 3, 4). The areolation of the carapace is incomplete. The cervical groove is visible only iu the posterior jjart of its course and at the point where it cuts the post-orbital crests ; between these limits it is altogether indistinguishable in adults, though sometimes obscurely defined in young specimens. As in F. browiieanuHi the antero-lateral boundaries of the mesogastric areola are wanting. In the middle line behind the cervical groove a pair of small lobules are distinguishable and behind these again are faint lateral grooves partially defining a cardiac areola. There is no trace of an ej)ibrancliial groove. The surface is for the juost part free from any granulation, but is sparsely and coarsely pitted. As a rule a pair of large and shallow pits are conspicuous on either side, placed in a transverse line in front of the posterior portion of the cervical groove. Close to the antero-lateral margin in the vicinity of the epibranchial tooth there is a small number (usually not more than half a dozen) of rather large tubercles. On the side-walls of the cai'apace there are inconspicuous oblique rugae which pass over the postero-lateral margins and are usually visible fioni aljove. The epigastric and post-orbital crests are well dcliiicd and together form a connnon curve ; the former extend latlier fai' forwards and would touch a line joining the posteii(»r limits of the orbits. The edges of the crests are coarsely pitted and have a rugose aj)peai'ance ; they are not undermined. The cervical ^I'oove cuts the post-orbital crests at an exceptionally oblitpie angle. The fissures between the epigastric and post-orbital crests are deep. 86 Records of the Indian Museum. [Yol. XIY, The frontal and post-orbital ret-ions are smooth, save for a larue and deep pit on the latter behind the cornea of the eye. There are two low eminences on the front which do not conceal the margin when the cara- pace is viewed from above. The front, in a true dorsal view, is seen to be deeply and widely emarginate in the middle, with the outer angles a trifle produced ; it is thus very obscurely quadrilobate. The upper orbital border is smooth ; the outer orbital angle is large and rectangular and is separated from the obscurely crenulated lower border by a wide notch. The antero-lateral border is strongly curved and very much shorter than the postero-lateral, and is characteristic in structure. In the pos- terior part of its course the border is defined as a ridge bearing serrations which gradually assume the form of spinules from behind forwards. In front of these serrations the margin is not defined as a crest, but its position is indicated by a variable number of very sharp isolated spines, the foremost being the largest. As a rule there are three of these spines, less commonly two or four (text-fig. 2a, h) ; they vary considerably in relative size and position and some of them occasionally bear a subsidiary denticle. The median tooth on the lower edge of the epistome is rather narrower than usual. The surface of the epistome, together wdth a small portion of the carapace on the outer side of each efferent branchial opening, bears some coarse hairs. The ischium of the external maxillipedes is grooved as usual and the nierus is rounded in outline and as long as broad (text-fig. 2c). On both ischium and merus there are some short hairs. The chelae are unequal in both sexes. The two lower margins of the merus are tubercular and the customary tooth is present on the lower surface near the carpal articulation ; on tlie upper surface there are some transverse rugae. The carpus is very coarsely and irregularly pitted above and there is usually a distinct depression or umbilication near the chela. The inner margin of the upper surface, above the large carpal spine is defined anteriorly by a blunt ridge and posteriorly by a row of four to six tubercles. In old females ^ tlie larger chela is deep, little more than twice as long as broad in lateral view, the lower border is sinuous, being emarginate at the distal end of the palm, the fixed finger is strongly curved with its lower edge convex and the fingers gape very widely at the base (text-fig. 2d). In young examples of both sexes, and in the smaller chelae of large females, the length of the chela is more than two and a half times its breadth, the lower border is nearly straight and the fingers gape but little when the claw is closed. The palm bears some ti'ansverse rugae on its upper surface, but is otherwise smooth both within and without, except for scanty pitting. On the outer side of the palm near the upper 'oorder there is a longitudinal dej)ression. There are longitudinal lows of ])its on the fingers but no distinct grooves. The teeth on the inner margins are conspicuous in small specimens and in the smaller chelae of large individuals. In the larger chelae of well grown examples they tend to become obsolete at the base. The pits on all the segments of the chela are sometimes found ^ 1 have not examined any large males. 1918.] Stanley Kemp: Dccapoda of the InJe Lal' legs is a little less than twice the length of the carapace. The jjropodites show only indistinct traces of the double anterior margin found in P. andersonianum and other species ; those of the penultimate pair vary from 2.^ to about 2| times as long as broad. The posterior margin of each propodus is armed with from two to four spinules and ends in a sharp spine. Fig. 2. — Potninon (Potamon) actnithicum, sp. nov, rt, b. Outline of left .side of carapace. c. Third inaxillipede. d. Chela of old female. e. Abdomen of male. In a male (not perhaps fully adult) the sixth abdominal somite is half as long as broad at the base, while the seventh, which is triangular is a little broader than long (text-fig. 2c). The measurements (in nun.) of the carapace in eight specimens are as follows : — Sex Length Breadth Depth Potamon acanthicum may be distinguished at a glance fi'om all other Indian Potamonidae by the character of the antero-lateral border of the carapace. The sharp isolated spines with which the anterior part of this border is provided apjiear to be an extreme modification of the serrate or cremdate margin seen in most s})ecies of the sul)genus Potamon ; they differ widely in character from the large flat teeth found in Indian species of Acanthotelphai^a. In Potamon niJoficuin,''- however, the type species of the subgenus Jcan/hotelphusa (and in a few other species all found in Africa or Madagascar) the teeth are small, conical and irregular, 1 Potninon {Paratdphiimi) niloticiis (M.-Ed\v.), Rathbuii, Xoar. Arch. Mus. Purin (4), VII, p. 26 3, pi. xii, fig. 15 (HJ05). o o 0 0 9 o ? 2 ■2-21 I!)-.-) 2.3-4 250 24-9 2:5-5 21-7 19-2 :5(l-4 L'(i(i .•5.-)-) :55-7 :54s :52-:! .•{0-2 25-5 l.->5 l.is l(i-7 l(i!) l(i-4 15-5 14-1 12-5 88 Records of the Indian ^l ii.seii in. [Voj,. XlV, much resemblinu those of P. acanthicum, whilst among accepted species of the subgenus Potamon, Miss Rathbun's P. shensiense,^ from China, may be cited as an instance of a form in which the crenulations of the antero-lateral margin have become spiniform, though not to the saine extent as in the species from the Shan States. The species seems then, so far as the antero-lateral Ijorder of the carapace is concerned, to have undergone modification on the same lines as P. {Potamon) shensiense and P. {AcantJwtelphusa) ndoticuin and its allies, though it is, in my opinion, clear that it is not closely related to either. Except iii the matter of the antero-lateral border P. shensiense shows the closest affinity with P. denticulatum (Milne- Edwards) ; it differs widely from P. acanthicum in the form of the epi- gastric and post-orbital crests. In P. niloticum the longitudinal groove on the ischium of the third maxillipedes (found in P. acanthicum and most Potamonidae) is absent, and there are great differences in the form of the carapace and its areolation. P. acanthicum must. I think, be regarded as a highly specialized offshoot of the ancestral stock that gave rise to P. andersoniamim and its allies. So far as I can discover no closely related forms are known to exist, and the evidence obtained by Dr. Annandale regarding the other elements of the fauna of the Inle system points to the conclusion that it evolved in the locality in which it is now found. The develop- ment of spines in place of serrations on the antero-lateral border of the carapace appears to have originated independently in P. acanthicum, P. shensiense and P. niloticum, and is thus aii instance of convergence.'-^ The colouration of living specimens of P. acanthicum is very striking : Dr. Annandale has kindly supplied me with the following note. " The dorsal surface is black or very dark green, except that the deep groove running across behind the orbits is pale greenish yellow with a blackish margin in front. The upper half of the chelae, including the v.'hole of the movable finger, is densely marbled with pale olive and greenish black ; the lower half, including the immovable finger, is pale yellowish. This particoloured character extends to the whole appendage. The articular membrane at the base of the claw is scarlet. The walking legs 1 Rathbun, Nouv. Arcli. Mus. Paris (4), VI, p. 2(J2, pi. ix, fig. 8 (1904). 2 There is one other point, not perhaps altogether disassociated from a discussion of the affinities of P. acantliicuin, to which I would like to refer. It conc-erns the .status of Acanttwtelplmsa as doiined by Alcock. That the meniber.s of this subgenus have been evolved from Potamon, s. s., will I think be generally admitted, but I am not convinced that the dividing line between the two subgenera is rightly j)laued. Tlie characters of AcantJioldplmsa given by Alcock are two, — " that the antero-lateral borders of the cara- pace are cut into large "teeth or sjiincs, and that the uj)per border of the merus of the chehpeds bears a subterminal spine." This description is in jjerfect agreenuMit with the Indian species, but ap])lies less well to PulaiHon inlulicuiii, tiie type of tlie subgenus. In th(> Egyptian species the teeth of the antero-lateral border, as has already been pointed out. are small and irregular in their disposition and the subterminal spine on the upper border of the merus of the chelipedes is, in females at any rate, non-existent. On the other hand the groove on the surface of the ischium of the third maxillipedes is absent in P. niloticum, as it is in certain of the Indian species, and this is a rare character in Potamonidae. Judging from the limited material at my disposal I am inclined to think that the Indian si^ecies referred by Alcock to Acanthoieljtlmsa differ more widely from P. niloticuin. than the latter does from typical sjjccies of Potamon, s. s. If this proves to be the case, Acanthoteljitiusa must once more revert to the synonymy of Potamon, while a new subgeneric name will be necessary for the Indian species and their allies. {See Postscriptum, p. 101.) 1918.] Stanley Kemp: Dccapiuhi of flic Iiilc Lake. 89 aro dull olivaceous speckled with black. The veutral surface is yellow- ish and the mouth-parts are stained with dull olive. Individuals from the Inle Lake are usually more brightly coloured than those from streams in the same district." This is apparently the only cral) that makes its way into the central region of the Inle Lake, on the Ijottom of \\liich it is occasionally found. It is more abundant among the roots of the floating islands at the edge of the lake, and also frequents small liill-streams. The Sjiecimens in the collection are from Yawn gh we State ; from the Inle Lake, 3U00 ft., and from He-Ho stream, 3800 ft. The types, which are from the former locality, bear the number 9771/10, Zool. Surv. Ind. Potamon (Potamon) curtobates, sp. nov. Plate xxiv, tigs. 5, (J. This species is allied to P. abbold. Ratlibuii. /-'. nioniatioti, Rathbun, and P. pealianum (Wood-Mason), but differs from all in tlie extreme depth and convexity of the carapace. The length of the carapace is a trifle less than three quarters its greatest breadth ; it is thus comparatively short and broad. The depth is always conspicuouslv more than half the greatest breadth (pi. xxiv, figs. 5, v.. The cervical groove is well defined posteriorly and the point where it cuts the post-orbital crests is usually clear ; in the intermediate part of its course it is exceedingly obscure. The mesogastric areola is remark- ably broad, its greatest breadth being almost or quite equal to one-third ¥\v,. 3. — I'otiuiKiii {pohnnon) curlobates, sp. nov. (I. OutliiK- of left side of carapace. b. "J'tiiid niaxillipctk'. c. AbcloiiR'ii of nuilc. the breadth of the carajiace. (in P. pcdltiniuiii it is oiiK- one (piarter the breadth.) The antei'o-latei'al boundaries of the ai'eola are usually obsolete in specimens of mediuu) size, but are visil)le in a very old male. The two small lobules behind the posterior limit of the cervical groove are not as a rule comj)letely tleflned. The upj)er suiface of the carapace is very strongly convex fore and aft and slightly so from side to side ; 90 Records of the Indian Museum. [YoL. XIY, it is for the most jjart smooth and shiiiiti,^ with a very fine microscopic •iranulatioii. Near the antei'o-lateral l)()rders it is conspicuously tuber- cular, the tubercles takin 7.0 7!) 01 .5-2 .5 1 (i? .•U;") l(i-4 ;{i 5-7 (V7 8-1 4-7 4-3 6" (>(i -.u-i i(i:5 ;>•! 5!) (i-8 8-2 4-7 4-4 S ns-f) i'S-7 l.SS 28 5o 6-3 7'2 4-2 41 ? r>7 l'7-4 V.Vi 2() 5 1 5-3 6-2 3-4 3-3 9 M iM-f) 12-.5 24 4-S ,5-5 (M 3-3 31 c? :«•") 1.5-8 7-8 irv.5 3-0 3-(3 4-2 2-3 2-0 1 As tabulated l.y ("outiere, Ann. Sci. Nat.. Zool. (8), Xll, p. 270 (18!)1). 94 Records of the Indian Muaeum. [Vol. XIV, In a series of several hundred specimens, which inchides many males with the appendix masculina fully devel()])ed, the second peraeopods are slender and invariably short, not exceeding half the total length ; it may be assumed, I think, that they never attain any greater develop- ment. In this respect the species appeals to be primitive and resembles such forms as PaJaemon Imnarrei,^ Milne-Edwards, and P. lanchesferi,^ de Man. With these it has perhaps some real affinity, but it is readily distinguished from both by the characters of the rostrum and by the proportions of the different segments of the legs. The development of the rostrum is unusual and should probably l)e taken as evidence of specialization. The single male, 66 mm. in length, described by de Man from Holl- andia in North New Guinea as Palaemon (Eupalaemon) sp.^ appears to be closely related to P. naso. The rostrum, with 11 teeth above and I) below, is similar, except that it is not quite so deep in lateral view. The second peraeopods are short ; but the proportionate lengths of the different segments are rather different (merus 7-5, carpus 10, palm 4-5. fingers 6-5), the fingers being nearly one and a half times the length of the palm. The fifth legs are much longer, reaching beyond the anten- nal scale by the dactylus and the distal third of the propodus.* Palaemon midtidens,^ Coutiere, from Madagascar, differs in its shorter rostrum with more nimrerous dorsal teeth and fewer ventral teeth. The second peraeopods are proportionately much longer and the palm is shorter than the fingers. The fifth legs reach beyond the apex of the rostrum. De Man's P. singiangensis,^ from Borneo, differs widely in the form of the rostrum and the second peraeopods are greatly developed in adults, their length equalling that of the body in males only 57 mm. in length. The segments bear spinules in adults and in their proportionate lengths differ somewhat from those of P. naso ; there are some small teeth on. the inner edges of the fingers. Dr. Annandale has given me the following note on the colouration of living specimens of P. naso. " General colour greyish. Rostrum dark grey. Antennae and antennules reddish. Fingers of chelae tinged with red ; a reddish ring on each joint of the large claw-legs. Dorsum of thorax clouded with grey ; a small grey spot at each side near the upper limits of the lateral surface on a level with the base of the rost- rum. An irregular grey bar sloping backwards and downwards from the lower orbital margin ; another, still more irregidar and broader, parallel to it a short distance posteriorly ; a backwardly directed lunate mark of the same shade about the same distance behind the second bar. and finally a third irregular bar directed straight downwards partly within the lunate mark, a short distance in front of the posterior margin 1 De Man, Rec. Ind. 71/».s., II, p. 222, pi. xix, fig. 4 (1908). 2 De Man, Notes Leyden Mus., XXXIII, p. 204 (1911) ; noin. nov. for P. paucidens, Lanohester, Pror. Znol. Sor. London, 1901, p. .")G8, pi. xxxiii, fia;. 4. » De Man, Zool. .Jalirh. Si/.st., p. 427, jil. xxix, figs. 10-12 (191.5). * The word " carpus " in the last line of de Man's desoii])tion is cnidently a misprint for " propodus." « Coutiere, Ann. Sci. Nat. Zool. (S), Xll, ]). :527, j)!. xiv. figs. 40, 40a (1901). 6 De Man, Notes Leyden iU«.y., XX, p. i:}8, pi. vi (1898). 1918.] Stanley Kemp : Vecapoda of the Inle Lahe. 95 of the thorax. A oreyish spot on each side of the posterior margin of each abdominal segment and above it a bar of the same cok)ur extend- ing across the dorsal surface. Telson irregularly cross-barred ; uropods mottled or clouded." " The Intha fishermen deny that they are acquainted with any prawns of larmier size and state that these aie never found in the lake, only in streams and rivers. They say that in cold weather prawns are attracted in large numbers to spots where hot springs flow^ into the river, but it is uncertain whether their statement refers to this or to the succeed- ing species." The larger specimens in the collection, several hundred in number, were obtained alive in the market at Nan-Pan. They were said to have come from Sizon in the Tang-do circle of Yawnghwe State in the river that runs south from the Inle Lake. A small specimen was obtained in a spring of slightly warm water close to Fort Stedman, within about half a mile of the lake. The tvpes bear the number 9777/10, T^ool. Suro. Ind. Palaemon hendersoni, de Man. 1007. Pithicriuiu (Piira iKihiciiKni .') Jicii(J('rs(ini, dv Man. Trans. Linn. Sor. Zaol. (■2). IX. ]>. 44(i. ])1. xxxiii. fitrs. (ili-GS. litld. Bi/ln/iiiv (I'ltni paldiiiion) heiKhrsoiti. I'athbmi. BiiU. M uk. Cotirp. ZooL, Barrdrd, Lit, p. 31(). pi. v, tig. ."5. lOl."). Pdhif'Hion hender-idin. Kemp, Bee. Ind. Mnv.. VIIT, ji. .'>(i:'., ))l. xix. tigs. 19-23. Four specimens of this species were obtained by Dr. Annandale in the He-Ho stream, Yawngwhe State, at an altitude of 3800 ft. The largest individual is a full grown male 65 mm. in total length and with carapace 19 mm. in length. The rostrum is longer than in typical specimens from the Darjiling district, reaching a little beyond the end of the antennular peduncle. It bears from 9 to 11 dorsal teeth, of which 3 (in one case only 2) are on the carapace. There are in each case 3 ventral teeth. In the large male the longer chelipede of the second pair is about 60 mm. in length, extending beyond the apex of the antennal scale by the chela and one half of the carpus. The ischium is 10 mm. in length, the merus 11 mm., the carpus 9 mm., the palm 16-7 mm. and the fingers 15-4 mm. The carpus is 4-4 mm. broad at the distal end and the palm 6-0 mm. in breadth and 4-9 mm. m thickness. In this individual, as well as in a smaller example only 10 mm. in total length, the fluting of the fingers of the second peraeopod is clearly shown. In the length, number and position of the rostral teeth the Inle specimens difTer slightly from those described by de Man and from those recorded from the Abor country, and examination of series from the Darjiling district, the Abor country, the Garo Hills and the Swa Reserve Forest in Burma seems to indicate that in respect of the rostrum there is a small but constant diiTerence between Burmese specimens and those from Assam and the Eastern Himalayas. I defer further discussion of this point until I have had the ojjportunity of examining in detail the large accunndation of unnamed Palaemonidae in the Indian Museum. Palaenio'}) hevdersoni is usually of an olivaceous colour in life, with or without darker markings. The colouration of specimens from the Dar- 96 Records of the hulian Musetuti . [YoL. XIV, jiling district is doseril)ed by Dr. Aiinaiidale thus. — '' Pale ti'auslucent yollowisli olive. A dark brown vertical bar on each side of the first abdominal segment and a mid-dorsal streak of the same colour on the first three abdominal segments." The smaller specimens frojn the He-Ho stream were " of a imiform dark greyish olive/' but the large male was strikingly different. Dr. Annamlale notes that " it was dark blue like a lobster, except for pale bars on the walking legs, pale edges to the outer uropods, pale tips to all the uropods and the telson and the pale fingers of the chelae, the tips of which were reddish. Dr. Annan- dale's observations on P. hendersoni in the Darjiling district and my own in the Abor country and in the Garo Hills indicate that the deep blue colour seen in this individual does not occur even in the largest males found in Assam and the Eastern Himalayas. Palaemon sp. A number of small specimens of Palaemon were found among weeds in a small spring of warm water near Fort Stedman, together with mimer- ous examples of Caridina weberi prox. var. sumatrensis and one young individual of Palaemon naso. The specimens, the largest of which is a male 30 mm. in length with the appendix masculina to all appearances fully developed, agree in general appearance with P. hendersoni. The rostrum is similar with 9 to 11 teeth above (2 or 3 of which are on the carapace) and with 3, 4 or 5 below. The carpus of the second peraeo- pods is, however, of nuich greater proportionate length, being in every instance considerably longer than the palm. In the male 30 mm. in length the second peraeopods are well developed reaching beyond the antennal scale by the chela and a portion of the carpus. At present our knowledge of the Burmese species of Palaemonidae is very scanty and I am unable to say Avhether these specimens belong to a small species of Palaemon, hitherto undescribed, or whether they represent a dwarfed race of some known form. Family ATYIDAE. Caridina annandalei, sp. nov. Plate XXV, figs. 6-15. The rostrum usually reaches about to the end of the second segment of the antennular ])eduncle ; in young individuals it is shorter, sometimes extending only to the end of the first segment, while in very large speci- mens it may reach beyond the middle of the ultimate segment. In lateral view the rostrum is rather strongly depressed, but the tip is fre- qaently a little upturned (fig. (')). On the upper border, which is strongly convex, there arc from 11 to 26 teeth (usually 14 to 23)^; in mf)st in- stances these teeth stretch uninterrui:)tedly from l)ase to ajX'x. but not 1 Of one hundiod specimens two have 1 1 dorsal teetli. one lias 12. five have 14, seven have 1.5, eight have !(>, fointeen have 17, eleven have IS, fourteen have 111, lifteen liave 20, five have 21, six have 22, five iiav(> 2.'>, two have 24, two have 25 and three have 26. J918.] Stanley Kemp: Decapod a of the Inle Lahe. 97 infrequently the distal sixth or seventh of the rostrum is unarmed. The teeth in the middle of the series are the most crowded and the posterior 2 to 4 (usually 3) are situated on the carapace behind the orbit. The lower maruin of the rostrum bears from 2 to 6 small teeth (usually 2 to 5, very rarely 1),^ situated in the distal third of its length. At the lower angle of the orbit there is a narrow projecting lobe, furnished with setae, and immediately below a sharp antennal spine. The antero-inferior angle of the carapace is rounded. The eyes are normal. The antennular somite is not dorsally carinate. The antennular peduncle (fig. 7) reaches to, or a little beyond the tip of the spine on the antennal scale. The lateral process does not nearly reach the end of the basal segment. The second segment' is long and slender ; in dorsal view its length is quite two and a half times its basal breadth. The antennal scale (fig. 8) is slender, from three and a half to rather more than four times as long as broad ; its outer margin is distinctly concave. The epipod of the third maxillipedes is short and pointed. The carpus of the first peraeopods (fig. 9) is from 3-0 to 3-1 times as long as its distal breadth ; rarely it is stouter, sometimes only 2-4: times as long as broad. The segment is remarkable for the entire absence of the excavation at the distal end. The second peraeopods (fig. 10) are slender and reach a little beyond the middle of the second segment of the antennular peduncle. The carpus is from 1\ to more than 8 times as long as its distal breadth ; the chela is from 4| to 5 times as long as wide with the fingers from 1| to 1| times the length of the palm. In the third peraeopods which reach about to the end of the anten- nular peduncle, the propodus is from 2-7 to 3-2 times the length of the dactyms (fig. 11). The latter segment is slender and bears from 8 to 12 spines (fig. 12). The fifth peraeopods are about the same length as the third, but the dactylus is proportionately longer, the propodus being from 2-2 to 2-5 times its length (fig. 13). The spinules on the dactylus vary in number from 44 to 66 (fig. 14) and appear to be least numerous in males. There are as usual eight branchiae aiul, in addition, the distal end of the epipod of the second maxillipede is divided into a small numbei' of plumes which doubtless have the function of gills. The ej)ipods on the first two peraeopods are fully formed ; that on the thiid ])air is small and rudimentary and that of the fourth paii' is entirely absent. The form of the endopod of the first pleopod of the male is shown in fig. 15. The telson is a little longer than the sixth somite ; its a])ex is broadly truncate and bears 6, 7 or 8 slender spines between the small spinules at its lateral angles. In addition there are from 3 to o {)airs of dorso- lateral spinides. The spinules on the outer uropod vary in numbei' from 9 to 13. The eggs are verv large ; when freshly extrudecl they are about 0-9 mm. in length and 0-55 mm. in breadth. When about to hatch ^ Of one hundred specimens one has only 1 ventral tooth, fourteen have 2 teelli, thirty-one have 3, thirty-two have 4, fifteen have o and seven have (3. 98 Records of flu: liiilion Mitsctun. fVoL. XIV, they are about l-O mm. by ()•() mm. Oviiierous females carry only from 15 to 25 eggs. Large specimens reach a total length of about 17 mm. Caridina annandalei is allied to C. excavata, Kemp,^ and C. hodyarti, Kemp,- from Assam, the three species differing so far as is known from all other members of the genus in the absence of the epipod at the base of the fourth legs. In other respects also they show signs of close affinity. Classified according to the scheme outlined by Bouvier in 1913 ^ all three would take a position near Caridina nilotica, from which, however, they differ in a number of conspicuous features. In addition to the absence of the epipod on the fourth legs the species resemble each other in their slender build, in the comparatively great proportionate length of the antennular peduncle, in the slightly marked or non-existent excavation at the distal end of the carpus of the hrst pair of legs and in the possession of large eggs. The species may be distinguished thus : — I. Rostrum long, extending at least beyond end of anten- nular peduncle, the distal part of its upper margin without teeth ; 2nd segment of antennular peduncle not more than twice as long as its basal breadth ; carpus of 1st peraeopod slightly excavate distally, that of 2nd peraeopod less than 6 times as long as broad ; dactylus of 5th leg about one-third the length of projjodus. A. Rostrum reaching beyond antennal scale, with a small sid)terniinal tooth on upper border ; orbital notch not unusually deeply excavated ; antennal scale 4-i times as long as broad ; carpus of 1st jjcraeopods about \\ times, that of 2nd about 3 times as long as broad ; dactylus of 3rd peraeo- pod with 0 or 7 teeth, that of .')th with about 25 teeth ; eggs 0-8 mm. in length ... ... C hnrlgarti. B. Rostrum not reaching beyond antennal scale, with- out a subterminal dorsal tooth ; orbital notch very deeply excavated ; antennal scale about 3 times as long as broad ; carpus of 1 st peraeopod about 3 times, that of 2nd about 51 times as long as broad ; dactylus of 3rd peraeopod with 8-10 teeth, that of 5th with 40-50 teeth ; eggs about 1 mm. in length ... ... ... C. excavata IT. Rostrum short, not reaching end of antennular pe- duncle, with teeth throughout the length of its upper border ; 2nd segment of antennular peduncle 2i times as long as its basal breadth ; carpus of 1st peraeopod not excavate distally, 3 to 3.V times as long as broad, that of 2nd more than 7 timers as long as broad ; dactylus of 5th leg less than one third the length of propodus. [Antennal scale 3 to 31 times as long as broad ; dactylus of 3rd peraeopod with 8-12 teeth, that of 5th pesraeopod with 44-0() teeth ; eggs 0-9-1 -0 mm. in length] ... C untianddlei. Caridina annandalei is very abundant among green weeds in ail parts of the Inle Lake * and is also common in flooded rice-fields and waterways in the Yawngwhe plain. In these localities it occurs at an altitude of 3000 ft. It was also found, though less |)lei\ti fully in the 1 Kemp, Rec. Ind. Mus., VIII, p. 300, pi. xx, figs. 32-35, pi. xxi, figs. 36, 37 (1913). •- Kemp, ibid., p. 309, pi. xx, figs. 29-31, pi. xxi, figs. 38, 39 (1913). 3 Bouvier, Trans. Linn. Soc. (2), Zool., XV, p. 4G2 (1913). ' Ovigerous females were found onlv in tiie lake. J91S.J Stanley Kemp : Dcconoda of the InJe Lale. 99 He-Ho rivor, at 380!) ft., amoiiL!,' the roots of trees and under ffoatin«; leaves and twi,us. Dr. Annandale has supplied me with the followinii, notes on the cohiuration of hvino speeimens. — '" Individuals from the open part of the lake were translucent but speckled luore or less densely with dark olive yreen arul shininc; white. On the sides of the thorax the dark specks tended to conoreoate in three broad vertical bars, but in this respect the colouration was variable. In darker individuals somewhat indefinite cross bars could also be detected on the |)()sterior margin of each abdominal segment. Individuals from the black w^ater of the He-Ho river were speckled with black or very dark purple, and had no white specks. There was a slanting dark bar a little behind the middle of the thorax and usually another, less distinct, in front of it. There was also a^n irregular dark mark near the posterior margin of the carapace. A dark spot w^as always present at the base of each pleopod and there was sometimes a round dark spot at each side of each abdominal seg- ment near the dorsal surface. The aberrant Trematode Cdridinicohi is usually to be found in the gill-chambers of individuals from the lake, and the Protozoon Colhurnia is abundant on their uropods and other appendages." In addition to the specimens from the 8han ))lateau, there are in the Indian Museum five specimens (two of which are ovigerous) obtained by Wof)d-Mason from " Upper Tenasserim," and two (one of which is ovigerous) found by Dr. Annandale in a swampy lake at Kawkareik, in level country in the interior of the Amherst district, Tenasserim, in March, 1908. The types, which are from the Inle Lake, bear the number 9783/10, Zool. Surv. Ind. Caridina weberi, de Man. IS!I2. Ciin'ill/Ki irpljeri. dc Man, in Wchcr.'-i Zool. Ertii'bn. /ie.i.^f Xied Osl.-lml. II, p. .'571, |)l. xxii. till. 2;>. prox. var. suraatrensis, de Man. 1892. C'lriiliiin ireberi var. .' to specimens from Deli in Sumatra, preserved in the Indian Museum) in typical var. snmalrensis. The character is an unusual one in Caridina and in some species {C. denh'cidafa, de Haan, for instance) appears to be of considerable specific importance. In the specimens from the Shan States the tooth is invariably present, but in samples of very closely related forms from other parts of India it is inconstant in its development."^ For the present, at least, I am not able to regard the character as having specific value in the C. weheri group. The second segment of the antennular prdujicle is short and stout, intermediate in form between de Man's figs. 23 and 23/ {he. cit.). The antennal scale is about two and three-quarter times as long as broad. The carpus of the first pair of peraeopods is deeply excavate and from 1-6 to 1-75 times as long as broad ; that of the second pair is from 4-5 to 5-5 times as long as broad. The fingers in the second pair are scarcely one and a half times as long as the palm. The propodus of the third peraeopods is from 3-2 to 3-8 times as long as the dactylus (rarely shorter : 2-8 times), the latter segment bearing 6 or 7 teeth. In the fifth peraeopods the propodus is from 2-9 to 3-2 times the length of the dactylus, the dactylus bearing from 27 to 33 spinules. There are from 13 to 18 movable spines on the outer uropod. Exceptionally large specimens reach a length of 19 mm. ; the majority of those in the collection are smaller, not exceeding 15 mm. The eggs are very large, about 1-1 mm. by 0-7 mm. in longer and shorter diameter. Ovigerous females carry very few eggs, the numbers in two instances in which they were removed and counted being 19 and 2G. This form differs from C. weheri var. sumatrensis in a number of par- ticulars which are apparently of subspecific importance : (/) both dorsal and ventral teeth of the rostrum are rather less numerous, {ii) the antero-inferior angle of the carapace is toothed, {Hi) the fingers of the second peraeopod are ])roportionately shorter in relation to the palm and the propodus of the third peraeopod shorter in relation to the dac- tylus and {iv) the eggs are very much larger. Dr. Annandale found a number of specimens in small streams running into the Inle Lake at an altitude of 3000 ft., and in those on the He-Ho plain at 3800 ft. It Avas occasionally found in the lake itself, near the edge, but never in the central region. The colouration of living sj)ecimens is described by Dr. Annandale as follows : — " In individuals from amonu' ureen Meeds in a small stream 1 Of one liundred specimen.^ two have no ventral teeth, twenty-four have 1 tontl), forty-tl\ro(! have 2 teeth, twenty-three have 3, .six have 4 and two have .'). 2 Thu.s in a Imndred s])ecimen.s of a form elosely allied to that obtained hy Dr. Annan- dale, fount! at 'riiHie\'elly in South India, Ihe antero-latci'al .'mule hears an aeute toofli in 18 ])er cent, of the sjjeciniens, is rectann) curfolxites, sp. nov. Figs. 5. 6. — Dorsal and frontal views of a male 44- S nnn. in breadth. Rec. Ind. MuS-.Vol.X1V. 1918. PLATE XKI\'. S. C. Moudul.photc Photogravurfs-Sui-vtvof Iiul in. Office;:. CnlPiitta.lSlB DECAPODA FP.OM THE S. SHAN STATES. EXPLANATION OF PLATE XXV. Palaemon naso, sp. no v. Fig. 1. — Lateral view of an adult male, enlarged. „ 2. — Kostrum of another specimen. ., 3. — Second peraeopod. ,, 4. — End of propodus and dactylus of third peraeopod. ,, 5. — Apex of telson. Caridina annandalei, sp. nov. Fig. 6. — Carapace, rostrum, etc., in lateral view, enlarged. 7. — Antennule in dorsal view. 8. — Antennal scale. 9. — First peraeopod. 10. — Second peraeopod. 11. — Propodus and dactylus of third peraeopod, 12. — Dactylus of third peraeopod, further enlarged. 13. — Propodus and dactylus of fifth peraeopod. 14. — Dactylus of fifth peraeopod, further enlarged. 1.5. — Endopod of first pleopod of male. REC. INI). Mi;S.. VOL. XIV, I'Jl^s. Platk XXV, A. C. Chowtihary del. Decapoda from the S. ."^han Statks. f RECORDS ol the 'NDIAN MUSEUM Vol. XVI, Pari V, No. 22. Notes on Crustacea Decapoda in ^u , .,- By 5. KEMP. C7\LCUTT7\ JULY, J9/9. XXII. NOTES ON CRUSTACEA DEC A POD A IN THE INDIAN MUSEUM. XII. SCOPIMERINAE. By Stanley Kemp, B. A., Supcrintoident , Zoological Survey of India. Plates XII, XIII. This subfamilv of Ocypodidae comprises a number of very small crabs found on the sea shore or in estuaries and backwaters. Eour genera have hitherto been recognised : — Scopimera, de Haan^ Dotilla, vStimpson (= Doto, de Haan), //yo />/(7 a;, Stimpson and Tym- panomerus , Rathbun (= Dioxippc, de Man). A fifth is here desctibed under the name Dotillopsis. The range of the subfamil}' extends from the southern and western coasts of Africa and the Retl Sea to the Banda Sea, the Philippine Is. and Japan. Its headquarters appear to be on the Indian coasts on which all tlie genera except th^ problematical Ilyoplax occur. Including the new forms here described thirty species of Scopimciiiae are now known: of these I have seen twent^^-one. Eighteen species are known from the Indian coasts and of these I have seen all but one and the types or paratypes of thirteen. The Scopimerine crabs are of small size as compared with the Oc3'podinae. They are all littoral or estuarine and strictly amphi- bious in habits. Unlike Ocypoda the coastal species live only in sheltered bays o\\ the shores of which surf never breaks. The species of Dotilla and Scopimcra burrow in damp sand between tide-marks and different forms are as a rule restricted to different levels on the beach. For example, both in Mormugao Bay on the west coast of India and at Tuticorin on the south-east coast Scop- iniera proxima and Dotilla myctiroides occur, the former inhabiting the zone near high-water mark, while the latter is to be found near low-water mark. Tympanonierus burrows in rather stiff clay ,or muddy sand, while Dotillopsis affects estuarine mud of ths/ softest consistency. All the species construct small oblique burrows, from 'which they remove the sand or mud in little pellets. This is done as often as the tide sinks and exposes the area in which they are living. In nearly all cases the pellets are disposed with some care, in such a way that one or more pathways are left clear on the surface round the mouth of the burrow. The path wa\'s themselves are smoothed and apparently hollowed out by the crab. The 3o6 Records of the Indian Museum. [Vol. XVI, arrangement of the pellets gives the burrow a very characteristic appearance, enabling it to be distinguished at a glance from that of young OcyPoda and other forms of similar habits. The crabs are gregarious and sometimes occur in very large numbers. Beaches occupied by them can occasionally be recognised at a considerable distance by their freshly raked surface. Little is known as to what occurs in these communities at high tide, but as they are very seldom obtained in nets hauled on suitable ground near the shore it is probable that they remain in their burrows. When the tide is out they may often be seen sitting at the mouths of the burrows or in the pathways leading to them, but seldom if ever wander further afield. Each crab or pair of crabs keeps rigidly to its burrow. The habits of the Indian species of Dotillopsis seem to be somewhat different from those of the other genera because the mud in which it burrows is too soft to retain a definite impression. It is often impossible to distinguish its holes, though it appears to excavate them in the same way. The dense tomentum on the walking legs in this genus and in certain species of Tympanomerus is probably an adaptation to life on muddy ground. Most of the species of Dotilla and Scopimera live on the sea- shore. A few make their way into backwaters, where the water is brackish or of very variable salinity, but the environment in such situations is as a rule unfavourable. The crabs usuall}^ fail to reach their normal size, and in species in which there are marked structural differences between the sexes, the males seem unable to attain their full development. Most species of Tympanomerus are found in estuaries, often near or even beyond the extreme limit of tidal influence. Both species of Dotillopsis are essentially estuarine, but the Indian form has been found in a small backwater near the open sea as well as a considerable way up the Gangetic delta. No species has been found at any great distance from the coast, but T deschampsi and T. stapietoni are able to live on the banks of large rivers at places wheie the water is always fresh. T. stapietoni is said to have destroyed a dynasty of kings in Eastern Bengal by burrowing through the embankments their people had constructed and so letting brackish water in to the rice-fields. In examining the Indian species of Scopimerinae I have met with instances of dimorphic forms in the female as well as in the male sex. In Dotilla intermedia two perfectly distinct types of adult male exist which dift'er conspicuously in the structure of the first segment of the abdominal sternum and chela and in the form of the copulator}^ appendage. Scopimera proxima presents still more interesting features, for it exhibits dimorphism of the female — a phenomenon not, I think, hitherto noticed in Decapod Crustacea. The dimorphism in this instance is to be found in the form of the abdomen and is very peculiar in that the scarcer and more aberrant form of female has characters approximating closely to those of the male. The remarkable point is that in this form the sides of igig.] vS. Kemp: Notes on Cnistacea Decapoda. 307 the abdomen are constricted as in tlie other sex. We have thus a female possessing a male character that can hardly be called secondary, for it can be demonstrated without difficulty that the purpose of the constriction in the male abdomen is that of per- mitting the copulatory appendages to remain exserted, while the abdomen is folded against the carapace This paper was almost completed before I became acquainted with Dr. Tesch's report on the Catometope crabs obtained by the ' Siboga ' Expedition, published in 19 18. In this report (pp. 40 et seq.) will be found a summary of the characters of the genera and species of the Scopimerinae and full descriptions of certain forms. My own work thus to a great extent covers the same ground as that traversed by Tesch, but there are considerable differences in our treatment, and, apart from the new species I have to intro- duce, an independent consideration of the subfamily will, I believe, have its uses. Tesch gives to the subfamity the name Mictyrinae and includes in it Latreille's Mictyris, usually placed in a separate family. This view is not supported by any discussion and, having examined both the species belonging to Latreille's genus, I am unable to give my adherence to it. Mictyris dift'ers from the members of all other Catometope families in a number of very important features. Apart from the absence of defined orbits and the extraordinary disposition of the third maxilhpeds, the mouth-parts differ widely from those of all genera of Ocypodidae with which I am acquainted, while in the possession of an unpaired accessory ]:)ranchial orifice at the extreme posterior end of the carapace the genus is unique among Decapoda.' 1 In ne.^rly all Brachyrhynchous crabs water is normally drawn into the branchial chamber through an aperture at the base of the chelipeds and is ex- pelled through the buccal cavern between the endostome and the distal ends of the outer maxilhpeds. In Mictyris and in certain Ocypodid genera, all of which are amphibious in habit, accessory passages to the branchial cavity are to be found. The external orifices of these passages are rendered conspicuous by reason of a thick fringe of short hairs which doubtless serves to prex'ent the intrusion of particles of sand. In Ocypoda ;und Getasimiis the orifice of the passage takes the form of a hairy-edged pouch situated between the bases of the 2nd and 3rd walking legs. From this pouch a channel passes upwards to the branchial cavity either through a gap between the upturned margins of the coxae (ver}' conspicuous in O. cerafop/it/iatiiia) or through an aperture behind their fused edges. In Heloecius similar pouches exist between both the ist and 2nd and between the 2nd and 3rd walking legs. Of Scopimerine genera Scopiinera possesses an accessory branchial passage with the orifice placed between the bases of the ist and 2nd legs, and similar passages also exist in certain species of Tympa)ionieriis, the orifices being found between the bases of the ist and 2nd, 2nd and 3rd and (sometimes) the 3rd and 4th walking legs. The unusual structure of the branchial opt.'ning at the base of the chelipeds in Mictyris has been described by .-Xlcock, who does not, however, refer to the accessory passage also found in this genus. The orifice of this passage differs from that of all the Ocypodid genera referred to .above in being impaired. It is situated at the extreme hinder end of the animal and is bounded dorsally by the short posterior margin of the carapace and ventrally by a strong transverse ridge on the first abdominal segment, bolh upper and lower borders being heavily 3o8 Records of the Indian Museum. [Vol. XVI, I am of the opinion that the resemblances between Mictyris and the Scopimerinae are convergent rather than genetic and I cannot beheve that the two have had a common origin distinct from that of the Ocypodinae and Macrophthahninae. Apart from the position of Mictyris I differ from Dr. Tesch on a number of points <}f lesser importance.' With more material before me than was at his disposal I believe that I have been able to discover generic characters of more constant value than those utilised by him on p. 41 of his report. In the possession of tympana, curious membranous areas found on the meral segments of the legs and sometimes on the thoracic sterna, the Scopimerinae differ from all other Decapoda ; in some of the genera, however, they are ill-defined and in certain species of Tympanomcrus they are altogether absent. The sub- family may be distinguished from the Oc^^podinae by the presence Text-fig. i. Endopod of second maxilliped. a. Scopimera globosa, de Haan. b. Tympanomerus gangeticus , sp. nov. of a fully formed pleurobranch above the base of the second walking legs and from the Macrophthalminae by the more oblique position and rudimentary character of the antennules and by the greater breadth of the interantennular septum. fringed with short hairs. From the slit-Hke opening thus formed a narrow channel passes forwards on either side to the branchial ca\ity, On placing a living specimen of Gelasimiis nciifus in a bowl of water and introducing a little coloured fluid at the base of the chelipeds I found that the fluid was immediately drawn in and expelled in the ordinary way through the upper part of the buccal cavern. I failed, however, to demonstrate that the accessory openings were similarly used in submerged individuals, e\cn though an attempt was made to inject the fluid into the pouch, and think it probable that they are employed only for taking in air. The presence of the fringe of hairs suggests that they are inhalent rather than exhalent. ' Kor instance I regard Dotilla sisrilloritm as a species of Scupiiiieni, D. clepsydi'odactylus as a synonym of D. intermedia and Cleistostoma liiigiitatuni as a species of Tympanomerus. igiQ-] S. Kemp : Notes on Crustacea Decapoda, 309 In recent years a large number of specimens of vScopimerinae have been added to the collection of the Zoological Surve^^ of India. We are indebted to Lt.-Col. C. R. Stevens, I.M.S., for a most valuable series from Karachi, comprising examples of several new and scarce forms. Lt.-Col. H. J. Walton, I. M.S., has contributed further specimens of Dotilla blanjordi, hitherto known only from the types, and Mr. J. Hornell, a smaU but interesting collection from Tuticorin. I have to thank Dr. F. H. Gravely for a very long series of Dotilla intermedia from the Orissa coast, material which has enabled me to demonstrate the existence of dimorphism among the males. Dr. J. G. de Man has kindly sent me examples of Tyuipanomerus pusillus, Dr. Nakazawa and Dr. Bruno Parisi specimens of Scopimera globosa. Excluding Ilyoplax, which cannot be recognised with certainty until the type species has been rediscovered, the genera of Scopi- merinae may be distinguished by the following characters : — I. Penultimate segment of 2nd maxilliped greatly ex- panded, with ultimate seyment applied to it laterally as a narrow strip (text-fig. i(/). A. A conspicuous brush of hairs, indicating the posi- tion of the accessory branchial orifice, between bases of ist and 2nd walking legs ; 4th segment of abdomen not overlapping 5th, nor with a brush of hair at its distal end ; abdomen of male with 4th or 5th segments constricted, the 5th occa- sionally linear. [Lateral walls of carapace usually without conspicuous sculpture] ... Scopimera. p. ,^n), B. No brush of hairs between bases of walking legs; 4th segment of abdomen o\'erlapping 5th and with a thick brush of hair at its distal end in both sexes ; abdomen of male not constricted. [Lateral wal.ls of carapace with deep convolute sculpture' ... .. ... ... Dofil/n. p- :-,2-^. IL Penultimate segment of 2nd maxillipL-d not expanded, with ultimate segment attached terminally (text-fig. ih). [4th segment of abdomen not overlapping 5th, nor with a brush of hair at its distal end.] A. Lateral walls of carapace with deep con\'olute sculpture: upper surface strongly sculptured; 4th segment of abdomen of mate remarkably expanded, nearly 3 times as broad as fifth . DotiUops'.s, p. 334- B. I'pper surface and lateral walls of carapace not conspicuously sculptured ; 4th segment of abdo- men of male not remarkabh- expanded though it may be broader than 5th ... ... TvDipaiionicnis, The tympana are well-defined and usually conspicuous in Scopimera and Dotilla, ill-defined in Dotillopsis and ill-defined or absent in Tympanomerus. The merus of the third maxilliped is longer than the ischium in Dotilla and Dotillopsis and longer than or equal to the ischium in Tympanomerus ; in some but not all the species of Scopimera the ischium is longer than the merus. A dense tomentum is found on the first three walking legs in Dotillopsis and similar but less extensive patches of hair are found in certain species of Tympanomerus. 310 Records of the Indian Museum. [Vol. XVI, The genera exhibit rather complex inter-relations. In the form of the abdomen and in the possession of hairy-edged pouches indicating openings into the branchial cavity Scopiniera is related to Tvnipanomerus , while Dotilla and Dotillopsis agree in the deep sculpture of the upper surface and side-walls of the carapace. On the other hand Scopiniera and Dotilla resemble each other and differ widely from Dotillopsis and Tympanomerus in the structure of the ultimate segments of the second maxilliped. The genus Ilvoplnx, which was described in 1858,' is based on a single species, /. ienella, " found at Whampoa, China, along the banks of the Canton River (brackish water), living in holes in the mud, exposed at low water. ' ' The fact that the meral segments of the legs possess tympana indicates that the genus must be referred to the Scopimerinae. Stimpson compares it with M acrophthalmus and remarks that it forms "'' a connecting link between the ^lacro- phthalmidae and the Dotillidae." To my mind it is unquestionably a very close ally of Tympanomerus and I strongly suspect that it will prove to be synonymous with that genus. This, however, cannot be accurately determined until /. tenella has been re- discovered. Genus Scopimcra, de Haan. 1833. Ocypode, subgen. Scopiniera. de Haan, in Siebold's Faun. 'Japan.. Crust., pp. 5, 24. 1852. Scopiniera, Milne- Fldwards. Ann. Sci. nat.. Zool., (3) XN'III, P; 153- igoo. Scopiniera, Alcock, 'jfourn. Asiaf. Soc. Bengal LXIX, p. 369. 1918. Scopiniera, Tesch, Decap. Brachyur. ' Sibog/i ' Exped. I, pp 41, 45. The species may be distinguished by the following charac- ters : — I. Ischium of third maxiiliprds iongXT than merus. A. Mid-dorsal surface of carapace with large symmetri- cal puckers or \'esicles ; chela with strong carina near inferior border ; last three segments of abdomen of male racket-shaped, the 5th lineiir, \er\' much nar- rower than 6th or 7th ... ... ... S. crabricauda. B. Micl-dorsa! surf.ace of carapace not conspicuously puc- kered ; chela with inferior border rounded ; 5th seg- ment of abdomen of male not linear, little if at all narrower than 6th and 7th. 1. Tympana on meral segments of walking legs not divided b}' a ridge. a. Lateral border of carapace defined by a crest throughout its length ; upper surface strongl)' granular; chelipeds of adult male little more than twice length of carapace ... .. S.globosa. "> b. Lateral border of carapace defined b)' a crest only in its anterior half ; upper surface feebly granular; chelipeds of adult male usually quite three times length of carapace. ... . S. piliila. 2. Tympana on meral segments of walking legs (except for that on upper surface of last leg) divided longitudinally by a narrow ridge. 1 Stimp.son, Proc. Acad. i\'af.Sci. Pliiladelpliia X, p. 08(1858) and Sniithson. Misc. Coll. XLIX, p. 100 (1907). IQIQ-] S. Kemp: Notes on Crustacea Decapoda. 311 a. Antero-lateral portions of carapace much in- flated and separated bj- an abrupt declivity from outer orbital angles ; 4th segment of male abdomen anleriorly emarginatc, not constricted, 5th longitudinally channelled ; abdomen of female with convex lateral margins . S. investigatoris. b. Antero-lateral portions of carapace not greatly intlated, sloping gently to outer orbital angles ; 4th seg'ment of male abdomen much constricted anteriorly, ^ih not channelled ; abdomen of female with concave lateral margins S. fyroxiiiin. II. Ischium of third maxillipeds shorter than merus. [Chela with strong- carina or row of granules near inferior border.] A. Ischium and merus of outer maxilliped studded with coarse tubercles. [Merus about twice as long as ischimn ; carpus of malecheliped without tooth at inner angle.] ... ... ... S. koc/ii. b. Ischium and merus of outer m.'ixilliped smooth, or nearh' so. 1. I'pper surface of carapaci- sculptured ; merus of third maxilliped three times as long as ischium ; carpus of male cheliped '.' . ... ... A', sigilloi'iim. 2. Upper surface of carapace without e\'id(_'nt sculp- ture ; merus of third maxilliped onl\' ,'i little longer than ischium ; carpus of male cheliped with a tooth at inner angle ,. S. iiiflafa. The species fall into four groups. Firstly the very highly specialized 5. crabncauda which differs widely in the form of the male abdomen from au}^ other species of the genus. Secondly 5. glohosa and 5. piiula which are normal forms. Thirdly S. investigatoris atid 5. proximn , allied to the foregoing but distin- guished by the presence of a ridge which bisects the lympana on the walking legs, and fourthly S. kochi, S. sigillormn and S. inflata which, though true Scopinieras, show affinity with Dot ilia in the proportions of the merus and ischium of the third maxillipeds and in the presence of a certain amount of sculpture on the lateral walls of the carapace. The Inrush of hairs between the bases of the first and second walking legs is very conspicuous in all the species of the genus that I have seen. A similar character is sometimes found in Tympanoiiienis, but occurs between the bases of other legs as well and is always much less easih' detected. 5. crahricauda, S. pihda , S. investigatoris and 5. proxiuia are Indian species. Scopimera crabricauda, Alcock. 1900. Scopiiuera crabyicaiutd, .\lcock, jourii. Asiaf. Soc .l-lciigal l,.\i.\, p. 370, and Illiisfr. Zool. R.I. M.S. ' Iiivesfigafor.' Crust , pi. Ixiii, In addition to the particulars given by Alcock it may be noted that in both sexes on the inner face of the chela there is a large blunt ridge, dorsally convex, extending from the base of the fixed finger to the carpal articulation. There are three finely serrate carinae on the fixed finger; the outer and inner reach only a short 312 Records of the Indian Museum. [Voiv. XVI, distance on to the palm, but the median traverses its whole length, running externally a little above the lower border. Two additional males of this scarce species, recentl}^ obtained by Lieut.-Col C. R. Stevens, I. M.S., are considerably smaller than the large male examined by Alcock ; the carapace of the larger is only 5 mm. in length and 83 mm. in greatest breadth. i.Lsji Karachi. A. O. Hume and Two. rvPF-s. F. Dav. ^i'■i- Karachi. C. R. Stevens. Two. Only these four specimens are known. Scopimera globosa, de Haan. Plate XII, fig. 2. 1835. Ocypode {Sropimei'u) globosa, de Haan, in Siebold's Faun, yapon.. Crust., p. 53, pi. .\i, figs. 3, 3 a, h. 1852. Scopimera globosa, Mihie-Edwards, Ann. Sci. nat., Zool. (3) X\'H[, p. I.S3- 1858. Scopimera fuberciilata. Slimpson, Proc. Acad. Sci. Pliiladelpliia X, p. 98. 1894. Scopimera globosa, Ortmann, Zool. Jalirb., Syst., VH, p. 747 1898. Scopimera globosa, Koelbel, in Wiss. Ei'gebn. Reise Grafen Bi'la, Szeclienyi in Osfasien, p. 57-?. 1902. Scopimera globosa, Dofljin, Abli. K. Raver. Akad . Wiss. XXI, p. 668. 1907. Scopimera tiiberctilata, Stimpson, Soiit/is. Misc. Coll. XLIX, p. loj. 1918. Scopimera globosa. Tesch, Decap. Brachvur. ' Siboga' Exped. I, p. 46, pi. iii, fig. 3. 1918. Scopjmera globosa, Parisi, .4ffi .S'oc Ital. Sci. .Yaf. LVTI, p. c)] . text- fig. 2. The carapace is more than one and a half times as broad as long and its depth is shghth' greater than its length. The upper surface is widest posteriorly, but the lateral walls slope outwards as well as downwards, the widest point being between the bases of the second pair of walking legs. The distance between the outer orbital angles is a little greater than the length. The upper surface is covered with a ve.y regular microscopic pitting, which gives it a dull appearance, and bears numerous smooth and shiny tubercles. The tubercles are most distinct on the lateral parts of the, upper surface and on the branchial regions they tend to form transverse and oblique rugae; above the base of the last leg there is a clearl}' marked curved and serrulate ridge. On either side of the gastric region there is a conspicuous indenta- tion from w4iich shallow puckers or grooves radi;ite forwards, out- wards and backwards. The gastric and cardiac regions are partialis'' separated from one another by a very inconspicuous transverse furrow; their lateral boundaries are sharply defined. The front is bluntly pointed and narrow, its breadth between the bases of the eyestalks being little more than a fifth the extra- orbital width. The edges of the front are raised and on each side there is a low granular ridge which curves inwards proximally, the iQiQ-] S. Kemp: Notes on Crustacea Decapoda. 313 two almost meeting between the bases of the eyestalks. The central portion is depressed and smooth with a low longitudinal ridge or elevation. The orbits have a strong dorsal inclination, the greater part of the cavity being visible in dorsal view. The upper border is sinuous and slopes obliquely backwards ; it has a smooth raised rim and terminates in a blunt extra-orbital tooth. The lower border is sharply denticulate and strongly curved. On the floor of the orbit there is a fine beaded ridge which runs outwards from the base of the eyestalks and meets the lower border in the outer third of its length. The lateral margin of the carapace is defined as a sharp crest extending from the orbital tooth to the base of the last legs ; it is finely crenulate throughout and fringed with short setae. Both above and below the crest there is a smooth longitudinal groove. The side-walls of the carapace are finely granular and setose. The endostomial margin almo'^t touches the ]:)asal segments of the antennules and antennae, the epistome consisting merely of a median triangular plate bearing a sharp transverse carina. The expanded penultimate segment of the second maxilliped (text-fig. la, p. 308) is not covered with long hairs as in S. pilula. The third maxillipeds bulge strong!}-. The ischium is longer than the merus and its breadth is a little greater than its length. The merus is nearh^ twice as broad as long and the suture between it and the ischium is decidedly oblique. The ischium is smooth except for some obscure granules postero-externally and for a raised line fringed with setae near the antero- lateral angle. There is a deep groo\e on the merus near its lateral border and on the inner side of the groove some low granules. A short blunt ridge runs to the articulation of the carpus. Antero-internally the surface of the merus is smooth and concave, with the margin reflected upwards. The chelipeds of the male, if straightened, would be rather more than twice the length of the carapace. The merus has a tympanum on its outer side, in breadth about half that of the seg- ment, and another, larger and less well defined on its inner surface ; except for the t^^mpana the segment is closely granular. The carpus is also granular and its upper surface is less than twice as long as broad in males. The three edges of the merus and the inner and outer edges of the carpus are rounded, not crested as in 5. pilula. The chela is a little longer than the carapace and is nearly three times as long as high ; its height near the carpal articulation is fulh- three quarters its greatest height. Both upper and lower borders of the palm are rounded and the entire surface, both within and without, is closely covered with scjuamiform granulation. The fingers are longer than the upper border of the palm, but shorter than its total length ; each is glabrous wdth four longitudinal, finely serrate carinae. Except near the tip the prehensile edges of the fingers bear small teeth, a group on the dactylus a little behind its middle point being rather larger than the others. 314 Records of the Indian Museum. [Vol. XVI, The first and second walking legs are nearly three times the length of the carapace ; the fourth pair is little more than two- thirds their length. The meri are expanded and bear ver^^ large tympana on both upper and lower surfaces. The dactyli in all four pairs are dorsally flattened ; in the first three pairs they are a little longer than, in the last pair nearly one and a half times as long as the propodus. Except for the dact^^li all the segments of the walking legs are finely granular and bear long scattered black bristles. In the abdomen of the male (text-fig. 2) the first three segments are short and broad. The fourth and fifth segments, taken together, are about as long as broad at base ; in their proximal half the^^ are deeply constricted, the least breadth being about half the length of the two combined. The suture between the fourth and fifth segments is deficient, not meeting the lateral margin on either side; it may be seen as a fine, anteriorly concave groove crossing the narrowest part of the constric- tion. The sixth and seventh segments are each broader than long. The carapace of a large male is about 87 mm. in length and 14 mm. in greatest breadth. I have not examined any females. I agree with Koelbel that Stimpson's 5. tuberculata is synony- mous with 5. globosa. Miiller's record from Trincomali ' is almost certainly erroneous and probably refers to 5. pilula. Text-fig. 2. — Scopimeya globosa, de Haan. Abdomen of male. '^f§i Kisara/u, Tok)-. Bay. -^T-Tf" Yokohama. I\.. Nakazawa. Four. .Mas. iMilano (B. Parisi). Five. De Haan gives no precise locality for the specimens he des- cribed. Other records are vSagami Bay (Ortmann, Doflein), Naga- saki (Ortmann), Smioda (Stimpson) and Hongkong (Koelbel). Scopimera pilula, sp. nov. Plate XII, fig. I. '.' 1S87. Scopiiueni globosn, Miiller \ iwc de Haan), ]'erli. Ges. Basel WW, P- 475- This species is very closely allied to S. globosa, differing only in the following particulars. The carapace is similar in shape to that of S. globosa and exhibits a shallow depression on either side of the gastric region. The puckers radiating from this depression are, however, much less I Miiller, IV/-//, Ges. Basel \II1, p. 475 (188; igiQ-] S. Kemp : Notes on Crustacea Decapoda. 315 conspicuous and the entire upper surface more smooth. There are tubercles, most evident laterally, but all are smaller than in S. globosa and they do not tend to form transverse rugae. There is, however, a granular elevation near the extra-orbital angle and a protuberance near the base of the last pair of legs. The lateral border, detined in S. glohosa as a sharp crest running the whole length of the carapace, is deficient. It is visible for a short distance behind the orbital angle and the side-walls beneath it are longitudinally grooved, but further back it is altogether wanting, the side- walls in the posterior half of the carapace meeting the upper surface without interruption. The front is slightly broader than in the allied species and is minutely nicked at the apex. The distal edge is thickened and behind it there is a large circular and completely circumscribed depression. There is a beaded ridge on the floor of the orbit as in S. glohosa, but it is shorter and meets the lower orbital border at about its middle point. The basal segments of the second maxillipeds bear very long wooll}^ hairs which entirely conceal the distal segments when the appendage is normally flexed. The outer maxillipeds closely resemble those of S. glohosa, but the merus is without granules and its sculpture is much less conspicuous. The chelipeds of the adult male are very much longer than in 5. globosa; in adults they are fully three times the length of the carapace. The edges both of the merus and carpus are crested. The carpus is proportionately much longer than in the allied species, the upper surface being more than two and a . half times as long as broad. The seg-^ Text-iio. r,.Scopimeni pilula. sp. nov. ment is transversely rugu-* chela of male, lose above, notsimph' granu- lar. The length of the chela (text-fig. 3) is distinctly greater than that of the carapace and differs in shape from that of 5. globosa ; the greatest height of the palm is about twice its height at the carpal articulation. The length of the dactylus is only about two-thirds that of the upper border of the palm. On both outer and inner sui faces the palm is covered with very fine granules which are arranged round small interspaces so as to give a reticulated ap- pearance. The ridges on the fingers are similar to those of -S. glohosa, but the cluster of enlarged teeth near the middle of the inner margin of the dactylus is much more conspicuous. In the female the cheliped is only about twice the length of the carapace ; the carpus is proportionately much shorter and the chela shorter, with fingers longer than the upper border of the palm The limb in consequence bears a close resemblance to that of male 5. globosa, but the borders of the merus and carpus are crested. 3i6 Records of the Indian Museum. [Vol. XVI, The first and second walking legs are about two and a half times the length of the carapace and are thus a little shorter than in S. globosa. In other respects the legs show little difference ; the merus is expanded, of similar proportions and bears large tympana. The abdomen of the male (text-fig. 4a) is similar to that of the allied species but the fourth and fifth segments are a little longer than their basal breadth and are less deeply constricted ; the breadth at the narrowest point is a little more than half the length. The sixth segment is about two- thirds as long as broad and the seventh nearly twice as broad as long. In the female (text-fig. 46) the segments from the first to the fifth increase regularly in length ; the fifth is about twice as V^road as long and a shade wider than the fourth. The lateral margins of the abdomen are very slightly concave. In all the females the pleopods are covered with a thick felted growth which under low magnification resembles colonies of small Polyzoa and is usually extruded in bunches between the ab- domen and the sternum. The growth in reality consists of stalks and broken shells of eggs from which the young crabs have escaped . In large males the carapace is about yo mm. in length and I0'6 mm. in greatest breadth. The females are a little smaller. In a young male from the vicinity of Tuticorin with carapace 37 mm. in length the chelipeds do not show the characteristic sexual development, though they are normally developed in an individual from the Burma coast with'carapace 4-0 mm. in length. The Tuticorin specimen appears to be abnormal and the collection of further specimens in the same locality might prove of interest. There can be little doubt that Miiller's record of S. globosa from Trincomali refers to this species. S. Kemp, l^'cb. 1913. Text-fig. 4. — Scopiniera piltda, sp. nov. a. Abdomen of male. b. Abdomen cf female. Backwater at Pamban, Ramnad dist., S. India. Small lagoon near Tuti- corin, S. India. Paway ( Pawe) 1., Mergui Archipelago. J. Hornell, Feb. 1918. .Many. One. Investigator 1914. I'cb The types are from Pamban and bear the number 9850/10, Zool. Surv. Ind. Scopimera invcstigatoris, Alcock. I goo. ScopiDiera investigatoHs, Alcock, 'Joiini. Asiat. Soc. Bengal LXIX, p. 369, and llliistf. Zool. ' hivesfigaior,' Cnisf., pi. Ixiii, tigs. 4. 4«. />■ I9I9-] S. Kemp : Notes on Crustacea Decapoda. 317 This species and S. proxima diiJer from all other members of the genus by the fact that the tympana on the meral segments of the walking legs, except for that on the upper surface of the last pair, are longitudinally div- ided by a narrow ridge; the tympana on the merus of the cheliped do not share this character. The two species may be con- trasted with S. mflata and 5. kochi, in which the tym- pana of the walking legs are normal, while that on the inner face of the merus of the cheliped is bisected. I give a fresh figure of the abdomen in this species for com- parison with that of the closely allied S. proxima. The specimens of S. investigatoris described by Alcock are from Burma. Additional examples are from the western side of the Bay of Bengal : — IVPES. Text- FIG. 5. — Scopinieyu investigatoris, .\ I cock. a. Abdomen of male. b. Abdomen of female. Diamond I., off C. ' Investigator." Ele\en. 1 Negrais, Burma. False Point, Orissa. ' Investigator." One (juv.) Chandipur, Baiasore, Orissa. F. H. Gravely, May, iyi6. Three. At Chandipur the species was found in company with Dotilla intermedia, de Man. Scopimera proxima, sp. nov. Plate XII, fig. 3. This species is an extremely close ally of S. investigatoris , but may be distinguished by its smoother carapace, less inflated antero-laterally and, in particular, by the different form of the abdomen. The carapace is of similar proportions to that of the allied species and is about one and a half times as broad as long, with its depth about equal to its length. In S. investigatoris a characteristic feature of the upper sur- face is the presence of an inflated and conspicuously granular area on each side near the antero-lateral angles. This area rises high above the orbital margin and is sharply defined anteriorly and externally by the steep and almost vertical declivity of its frontal and lateral borders, its separation from the outer orbital angle being conspicuous ; posteriorly and internally it merges gradually into the general surface of the carapace. The granules of 3i8 Records of the Indian Museum. [Vol. XVI, this elevated area are continued backwards in irregular fashion, terminating in a cluster near the base of the last pair of legs. There are also scattered granules on other parts of the carap- ace, the gastric and cardiac regions excepted, and a few on cither side of the basal part of the front near the insertion of the eye- stalks In S. proxima the condition is different. The antero-lateral portions of the carapace are only a little swollen, the surface sloping gently upwards and backwards from the orbital border without any indication of the abrupt declivity seen in the allied species. The granules are fewer and much less conspicuous, though they may sometimes be traced back- wards to the base of the last pair of legs. The other parts of the carapace are quite smooth and there are no tuber- cles at the base of the front. When the carapace is viewed from in front the lower orbital border appears more strongly sinuous than in the allied '''7;;vS.'-;,f?ov""" ^Pe^ies and the facet at its inner end Endopod of second maxilli- ™ore sharply defined. ped. The third maxillipeds closely resemble those of S. investigatoris ; they do not, however, show any trace of the obscure granules often seen in large specimens of the latter species and there is merely a shallow furrow parallel with the outer border of the merus, in place of an incised groove. The chelipeds are short in both species and otherwise resemble each other very closely. In S. proxima all three edges of the merus are sharp and serrate, whereas in S. investigatoris the upper edge, though compressed, is distinctly rounded. In the latter species the inner limit of the upper surface of the carpus is defined proximally by a short crest which is wanting in S. proxima. The upper and lower borders of the palm are rounded in both species and there is little difference in the shape of the chela ; the granu- lation is, however, a little coarser in S. proxima and the teeth on the prehensile edges of the fingers are larger and sharper. I have not found any distinctions in the walking legs. The abdomen of the male of S. investigatoris has been figured by Alcock, but the form of the fourth segment is not quite correct, the distal angles being a little more produced than he has shown. I give a fresh figure of the male and female abdomen (text-fig. 5) for comparison with those of 5. proxima (text-fig. 7). In 5. in- vestigatoris the fourth segment in the male is broad distally with produced outer angles, the fifth narrow, constricted at the base and deeply channelled, the sixth longer than broad with parallel sides. In 5. proxima there is a very deep constriction at the junc- tion of the fourth and fifth segments, the anterior end of the I9I9-1 S. Kemp : Notes on Crustacea Decapoda. 319 former being exceedingly narrow ' ; the fifth segment is not chan- nelled and the sixth is a little broader than long with straight, slightly divergent sides. In the abdomen of the female the differences are less marked. In S. invcstigatoris (text-fig. 56) it is rather broad, with slightly convex sides and with the seventh segment narrow ; in S. proxi- ma (text-fig. yc) it is proportionately narrower, with the sides a trifle concave and the seventh segment broader. Among a large number of specimens of 5. proxima I have found ten in which the abdomen does not correspond with the normal type of either sex. In general outline (text-fig. yb) the abdomen is similar to that of the normal male, but the constric- tion at the junction of the fourth and fifth segments is less deep, the fifth segment is proportionately broader and shorter and the sixth broader with convex lateral margins. On raising the abdo- men four pairs of pleopods are found as in normal females. Text-fig. 7. — Scophnera proxima, sp. nox- a. Abdomen of male. b. Abdomen of abnormal female. c. Abdomen of normal female. At first it seemed probable that these specimens were males, infected by some parasite which had castrated them and rendered abortive the normal development of the secondary male characters. No parasite could, however, be discovered and on dissection ovarian eggs were found which differed in no respect from those obtained by the same method from normal females. There is, in consequence, very little doubt that the specimens are females and capable of breeding. That very aged females occasionally assume some of the secondary sexual characters of the male is well known, but it does not seem probable that this will aft'ord an explanation of the abnormal females in 5, proxima. None of them is at all excep- i The sides of the constricted portion are bevelled, so that the seij^inents would appear broader if viewed from beneath. 320 Records of the Indian Museum [Vol. XVI, tional in size and the presence of ovarian eggs indicates that they are capable of breeding and not, therefore, senile. The instance appears to be one of female sexual dimorphism, a phenomenon not, I believe, hitherto noticed among Decapod Crustacea. It is very remarkable that the abdomen should be constricted in the abnormal females. In males the copulatory appendages can be exserted through the notches formed by the constriction and can remain in this position with the abdomen folded against the sternum: at the time of their capture many males of S. proxi- ma were found with the appendages exposed. The modification of the abdomen seems thus to have a definite function in the male; in the female it is difificult to see how it can serve any useful purpose. Of 87 specimens of 5. proxima collected in Mormugao Bay in Portuguese India 50 are males, 31 normal females (2 ovigerous) and 6 abnormal females. Of 14 specimens from the neighbourhood of Tuticorin in S. India 9 are males, 4 normal females (i ovigerous) and I an abnormal female. Of 16 specimens from Ennur back- water, near Madras, 6 are males, 7 normal females and 3 abnormal females. In large males the carapace is about 4*4 mm. in length and 7 mm. in breadth. 9^i.|-4 Vasco da Gania Bay, S- KcMiip ; .\ug-., Sept., Seventy-one. Mormugao Bay, Portu- 19 16. guese India. s-^^zn Donna Paula Bay, Mor- i»icia inflata, A. Milne- Kdwards, Joiirii. Mits. Gudeffi-oy, Heft IV, p. 83. ' - - In the collection of the Zoological vSurvey is preserved a single individual bearing the label ' ' 1423. Scopiviera inflata , A. M.- Edvv. Indian Ocean. Purchased." This specimen is one of very considerable interest and, though its history is not altogether free from doubt, there is every reason to believe that it is one of the original examples determined by A. Milne-Edwards. The register of the Crustacean collections contains under No. 1423 no information additional to that on the label, except that it is noted that only one specimen of the species was obtained. On the same page, however, are entries of a number of other Crus- tacea, also acquired by purchase and all apparently forming a single consignment, from Upolu, Samoa and the Viti Is. The entries were evidently made in 1875 or 1876. In the Annual Report of the Trustees of the Indian Museum for 1874-75 there is a statement that a collection of Crustacea "mostly from Southern Seas" was purchased from the Godeffroy Museum, while in the issue for 1875-76 it is noted that over 100 species of Crustacea (evidently a second consignment) were obtained from the same source, Mr. J. Wood-Mason, who came to Calcutta in 1869 as assistant Curator of the Indian Museum, devoted a great deal of time to the acquisition of a representative collection of named Crus- tacea— of this the registers and annual reports from 1873 and on- wards contain abundant proof. He evidently took steps to obtain a set of duplicates^rom the Godeffroy Museum as soon as Milne-Ed- wards' paper appeared, and there can hardly be a doubt that the example of 5. inflata was one of the specimens then acquired. It will be observed that in the original description the only note regarding locality is '' Habite la mer des Indes." The specimen is an adult female and is unfortunately in poor condition; the carapace is partiall}^ detached and the only legs remaining are those of the hrst two pairs. It is not possible to measure the carapace satisfactorily, but there can be no doubt that it is proportionately much broader than in other species of the genus. The length appears to have been 6*5 mm. or a little more, and the breadth at the orbital angles nearh^ 10 mm., the greatest breadth apparently exceeding 12 mm. These figures do not agree with those given b}' Milne-Edwards, who gives the length as 10 mm. and the breadth as 13 mm.; the former mea- surem.ent perhaps represents the total length and not, as stated, that of the carapace only. The upper surface of the carapace is very strongly convex antero-posteriorl}', but in transverse direction is almost flat over the greater part of its breadth, sloping abruptly downwards on either side. Antero-laterally the surface is very greatly inflated, bulging upwards and forwards to such an extent that in a true dorsal view the upper orbital border is, in the middle of its length, 322 Records of the Indian Museum. [Vol. XVI, Text-fig. 8. — Scopimera in- fata, A. Milne-Edwards. Third maxilliped. altogether concealed. The gastric and cardiac regions are smooth, but laterally the tubercles mentioned in the original description can be made out; apart from these the upper surface appears to be without evident sculpture. The side- walls are finely granular and seem to show traces of a rather deep sculpture, the grooves apparently forming a pattern somewhat similar to those found in Dotilla mydiroides ; it is, however, difficult to be certain about this point owing to the poor condition of the specimen. The epistome is very broad and exceptionally short. The penultimate segment of the second maxilliped is broader and the last segment more parallel-sided and proportionate!}' longer and narrower than in other species of Scopimera. The third maxillipeds are also unusu- ally broad and differ from normal spe- cies of the genus in having the ischium shorter than the merus (text-fig. 8). The ischium has a rather thick patch of hairs near its postero-lateral angle and the suture between it and the merus is nearly transverse. The me- rus is one third broader than long and decidedly longer than the ischi- um ; it is very little narrowed distally and is angled antero-internally. The anterior margin is reflected upwards, a short ridge runs backwards from the carpal articulation and there is a deep groove parallel with the lateral margin. The chelipeds are about 15 mm. in length. There is a large tympanum on the inner face of the merus, subdivided longitudin- ally by a ridge as in Roux's S. kochi. The tympanum on the outer face is without this ridge and is a Httle smaller, though broad and in length about half that of the segment. Except for the tympana the entire segment is finely granular. A. Milne-Edwards in his description says " avant-bras allonge et arme d'une epine a son angle interne." This statement refers to the male. In the female there is no tooth, but the inner margin is concave and sharp- edged anteriorly and is obtusely angled in front of its middle point : in this respect there is a great difference between S. inflata and S. globosa. The carpus of the female is not elongate ; its upper surface is about one and a half times as long as broad and is closely covered with granules. The chela is about 8 mm. in length and its greatest height, which is about twice that at the articulation of the carpus, is 3*7 mm. The whole palm is strongly compressed and the entire outer surface is conspicuously granular. The upper border is not carinate. On the outer side near the lower border there is a sharply defined beaded carina which extends from the proximal end to the distal third of the fixed finger ; on the inner side a simi- lar, but even more strongly marked, carina reaches from the carpal articulation to the middle of the inner side of the fixed finger. 1919.I S. Kemp : Notes on Cyustacea Decapoda. 323 The lower surface of the palm, bounded by these two crests, is only slightly convex ; it bears rather large scattered granules, some of which towards the distal end are arranged in a single row and thus form a low ridge which extends to the middle of the finger. The fingers themselves are nearly twice the length of the upper border of the palm. On the prehensile edge of the fixed finger there is, in the basal two thirds, a series of small inconspicuous teeth ; the same margin of the dactylus is similarly armed, but some of the teeth at the proximal end are situated on a low convex crest, the counterpart it would seem of the large triangular tooth found in tills position in the male. On the upper and outer borders of the dactylus are longitudinal rows of granules. In the first pair of walking legs, which alone remains in the specimen examined, the merus is a little more than twice as long as broad ; it bears large tympana on both sides, not divided by a longitudinal ridge. The propodus is stout, a trifle more than twice as long as broad, and bears on its anterior face a strong longitudinal ridge The dact3'lus is one and a half times as long as the propodus. The abdomen is very broad covering practically the whole of the sternum. Scopimera infiala is allied to 5. kochi, Roux, and S. sigillo- rum (Rathbun). The three species resemble Dotilla and differ from normal members of the genus in two points,— (i) the merus of the outer maxillipeds is longer than the ischium and (ii) the side-walls of the carapace are to some extent sculptured. In S. inflata and S. kochi the tympanum on the inner face of the merus of the cheUped is divided longitudinally by a narrow ridge and the same character, though not mentioned in the description, is perhaps also to be found in S. sigillorum. In other species of Scopimera the tympana on the chelipeds are not bisected ; but those on the walking legs are divided in an exactly similar manner in 5. investigaioris and 5. proxima. There can be little doubt that S. inflata is correctly referred to the genus Scopimera. In the female I have examined the accessory branchial orifice is situated between the bases of the first and second walking legs and is thickly fringed witli hair, while the abdomen does not possess the peculiar form invariably met with in Dotilla. The abdomen of the male, as described by Milne-Edwards, is similar to that of S. glohosa. Scopimera kochi, judging from Roux's excellent description, is a closely related form, differring in the sculpture of the upper surface of the carapace, in the form and coarse tuberculation of the outer maxillipeds and in the absence of a tooth at the inner angle of the carpus of the cheliped in the male. S. sigillorum, described by Miss Rathbun as a species of Dotilla, is unfortunately known only from a single female speci- men. The statement that the abdomen is subcircular indicates that it cannot be included in the genus Dotilla as here defined. In most respects the species appears to be very closely related to S. inflata, but the carapace is more distinctly areolated and 324 Records of the Indian Museum. [Vol. XVI, the merus of the outer maxiUiped is proportionately much longer, being three times the length of the ischium. The brush of hair between the bases of the first two walking legs is not mentioned either by Roux or by Miss Rathbun. Scopimera kochi, Roux. 191 7. Scopimera kochi, Roux, in Nova Guinea: Resiiltafs Exped. Sci. Neerl. NoiiveUe-Guinea V, Zool., p. 610, pi. xxvii, figs. 21-24. Merauke, New Guinea. Scopimera sigillorum (Rathbun). IQ14. Dotilla sigillorum, Rathbun, Proc. U.S. Nat. Miis. XIA'II, p. S,V Sandakan Bav, Borneo. I have not seen examples of either of these species. As noted above they ippear to be related to S. infiata. Genus Dotilla, Stimpson. 1835. Doto, de Haan, in Siebold's Faun. Japon.. Crust., p. 24. 1852. Doto, Milne-Edwards, Ann. Sci. nat., Zool., (3) XVIll, p. 152 ( nom. praeocc. ). 1858, Dotilla, Stimpson, Proc. Acad. Sci. Philadelphia, p. 98. 1900. Dotilla, Alcock, Jouru. Asiat. Soc. Bengal LXIX, p. 363 (/;; part). 1918. Dotilla, Tesch, Decap. Brachyur. Siboga' Exped. I. pp. 41, 43 (//; part). From this genus I have separated two species, D. brevitarsis, de Man and D. profuga, NobiU, and have placed them in a new^ genus to which I have given the name DoHllopsis. The remain- ing species — in my opinion only eight in number — form a very homogeneous group, distinguishable at a glance from anj^- other genus of crabs by the curious formation of the abdomen. The fourth segment overlaps the fifth and is furnished at its distal end with a conspicuous brush of hair. Many authors have remarked that they have seen no female Dotilla, but it does net appear that females are really scarce. The sexes, however, resemble each other so closely in the form of the abdomen that it is next to impossible to distinguish them without examination of the pleopods. The genus shows affinity with Scopimera in the form of the distal segments of the second maxilliped, but lacks the accessor}' branchial passage found in that genus. In the deep convolute sculpture of the side- walls of the carapace it resembles DoHllopsis and, less markedly perhaps, the species of the inflata-group of Scopimera. As regards the species, I have already referred Miss Rathbun's D. sigillorum to the genus Scopimera and, as noted above, two other species are placed in Dotillopsis. I agree with Nobili and Laurie that Alcock's D. affims is synonymous with D. sulcata, iqig. .'>. Kemp : Notes on Crustacea Decapoda. 325 Forskal. D. clepsydrodactylus, Alcock, appears to me to be nothing more than a fully developed form of D. intermedia, de Man, while Stebbing's D. clepsydra does not seem to be distinguishable from Hilgendorf's D. ienestrata. The mutual affinities of the species are best understood by a stud}' of the grooves of the carapace. In text-fig. q will be found illustrations of the carapace of six species, the figures represent- ing all the known types of sculpture. Two species I have not seen, — D. jenestrata, in which the sculpture is almost identical with that of D. sulcata, and D. m%laharica, which in this respect bears a close resemblance to D. pertinax. Tf.xp-i'ig. (). — Carapace sculpiurr in Dotilla. a. D. myctiroides (Milne-Edwards). d. D. wiclimanni, de Man. b. D. sulcata (Forskil). e. D. blanfordi, Alcock. c. D. pertinax, Kemp. /. D. intermedia, de Man. The species are often difficult to determine, partly owing to the fact that the grooves of the carapace are not easy to observe and partly because samples from a particular locality frequently consist only of comparatively small individuals, to the exclusion of large males with well developed secondary sexual characters. I have already remarked (p. 306) that the absence of full grown males is, in certain cases at any rate, to be attributed to an unfavourable environment. Males of D. intermedia are subject to a well-marked dimorphism. With the exception of D. jenestrata all the known species of Dotitla have been found on the Indian coast. They may be dis- tinguished thus : — 326 Records of the Indian Museum. [Vol. XVI, I. Carapace as long as broad, except for the lateral grooves practically dc\oid of sculpture ; chelipeds at least three times length of carapace. [Tympana on all segments of sternum]'... ... ' .. ... ... D. invctiroides/ II. Carapace broader than longv its surface strongly sculp- tured ; chelipedes at most little more than twice length of carapace. A. Groove parallel to lateral margin of carapace anteri- orly bifurcated or Y-shaped. 1. Two long parallel A -shaped grooves on dorsum of carapace, the lower enclosing a large triangular plane area with b.-ise occupying the whole of the posterior margin. a. Tympana present on 2nd and ;>rd segments of sternum ; fingers of chela longer than palm, each in the adult male with a large tooth on its inner edge ... ... ... ■•• D. ft- nest rata. - b. No tvmpana on sternum ; fingers of chela not longer than palm and without large teeth ... D. siilaffa..^ 2. No parallel A -shaped grooves on dorsum of carapace; a cardio-intestinal area (much narrow- er than posterior margin ) defined by lateral grooves. a. Gastric area triangular ; a faint transverse groove near posterior margin ; dactylus of last leg not 1 1 times as long as propodus ... D. pert max. b. Gastric area pentagonal ; no posterior trans- verse groove ; dactylus of last leg 2ee as long as propodus ... ... D. malabarica. B. Groove parallel to lateral margin of carapace simple, not bifurcated anteriorly. 1. Gastric and cardiac areas entire, not divided by a median longitudinal groove ; tran.sverse groove near posterior margin incomplete in the iniddle; no lobules isolated by grooves on gastric region; adult male with a tooth below orbital angle and a strong compressed tubercle on inner and proxi- mal aspect of carpus of cheliped ; tympana on all segments of sternum ... ... ... D. ivicliDiaiini. ■* 2. A deep mid-dorsal groox'e extending from front to posterior margin ; transverse posterior groove complete; 4 (or ;^) small lobules on gastric re- gion isolated by groo\'es ; no tooth below orbit.al angle and no tubercle on carpus ot chelii^cd ; no tympana on sternum. a. Only a single oblicjue groo\e running from side of cardiac region towards postero- lateral angle ; lower surface of palm not carinatc ... D. blanfonli . b. Two oblique grooves running- from side of cardiac region towards posterf)-lateral angle ; lower surface of palm strongly carinate ... D. intermedia. Dotilla myctiroides (Milne-Edwards). 1900. Dotilla mvctiroides, .\lcock, 'Joitrii. Asiat. Soc. Bengal LXIX, p. 368.' igoo, Scoptmera myctiroides, Manchester, Proc. Zool . Soc. London, p. 760, pi. xlvii, fig. 14. 1907. Dotilla myctiroides, Stimpson, S/nitlisoii. Misc. Coll. XLIX, p. loi. 1907. Dotilla myctiroides, Willey, Spolia Zeylanica \', p. 38. 1915. Dotilla myctiroides, Kemp, Mem. Ind. Miis. V, p. 227, fig. 8. ' Sternal tympana otherwise occur onlv in D. fenestrata and D. ivichmanni. 1919-] ^- Kemp : Notes on Crustacea Decapoda. 327 References prior to 1900 are given by Alcock, who records the species from the Andamans and the Coromandel coast. Addi- tional specimens are from the following localities : — '•■yl^i Vasco da (iama Bay, Mor- S. Kemp ; Aug., Sept.. 'l'liiri\. niugao Bay, Portuguese iyi6. India -»f^5 Bay i\. \V. of Nazareth Ft., i/o. Six. Mormugao Bay, Portu- guese India. -j%~ Tuticorin, S. India. J. Hornell ; h\\>., n^iS. I'wenty-four. ~fo^ Pamban baikwatcr, Kainnad S. Kemp ; l*"fb , IQI,^. Sc\en. dist., S. India. -yj^- Knnur backwater, nr. Madras. N. Ann.indaifc ; Oct.. One (ovig,). 1913- m,^ Outer channel of thilk.i Lake, Chilka Survey, March, One. Orissa. IQI-I-- ^To~ Maungma-gan, TaxoN-, Bur- |. Coggin Browti. Five. ma. ~io^ Pawa\- I Pa we ) I., Mergui ' Inxestigator.' I^'cIj., I'Our. Archipelago. 1914- »f^' Port Blair, .Xnd.imans. K. P. .Mullins ; June. Seven. I g I S . In the first of these localities the species was exceedingly abundant on sandy ground with a small admixture of mud. The colonies occupied extensive tracts near low-water mark ; the bur- rows were very closely packed together and the whole surface of the sand was covered with pellets to a depth of nearly an inch. It is perhaps due to this overcrowding that the specimens are decidedly smaller than usual, none exceeding 6'5 mm. in length of carapace. With the species, but in isolated burrows near high-water mark, was found Scopimera proxima and Mr. Hornell found the two forms associated in the same way at Tuticorin Dotilla myciiroides is frequently found in places where the water is brackish. Dr. Annandale found an ovigerous female in such a situation at Ennur and, at the time specimens were taken, the specific gravity of the water in Vasco da Gama Bay was i'Oi65 (corrected). The species has been recorded from Mahe (Milne-Edwards),' Rameswaram I., Tuticorin and Ennur (Henderson), Singapore (Walker, Lanchester), Java (Brit. Mus., fide Henderson), Caspar Straits (Stimpson) and Billiton I. and Mindanao (Aurivillius). Henderson gives " Seychelles (Miers)," but I have not succeeded in tracing the record. Dotilla fencstrata, Hilgendorf. 184;,. Doto siilcatiis, Kraus.:, Sndafnk. -Crust., p. 39 (Stuttgart). i86y. Dotilla fenestnita. Hilgendorf, in von der Decken's Reiseii Ost.- Afi-ika III, p 85, pi. iii, iigs. 5, ^Ihc. i87(). Dotilla feiiestiuita, Hilgendorf, Mouatsb. K. Preiiss. Akad. Wiss., 1878, p. 806. 1884. Dotilla feuestrata, Miers, Zool. H.M.S. 'Alert; p. 543. 1893. Dotilla fenestvata, \\x\-\\W\\\xi. '^'ov. Act. Reg. Sac. Sci. Upsala, ser. Ill, p. 12, pi. i, tigs. 14, 15. ' FresuinabK' the Mahe on the Malabar coast. 328 Records of the Indian Museum. [Vol. XVI, 1894. Dotilla feiiestrafa, Ortniann, Zuol. 'Jalirh, Cyxt., \'ll, p. 748. iQo^. Dotilla feiiestrafa, I.enz, Abh. Seiick. Natttrf. Ges. Frankfurt XXV II, p. 367. 1917. Dntilla clepsydra, Stebbing-, Ami. Durban Mas. II, p. 18, pi. v. Stebbing records D. clepsydra from Durban Ba}' and compares it with Alcock's D. clepsydrvdactylus [=D. intermedia, de Man), which it resembles in the structure of the chela of the adult male. Apparently, however, he has failed to notice that D. fenesfrata, which also inhabits the S. African coast, possesses a chela of precisely this type. I have little doubt that the two are synonymous. Judging from the very rough figure the sculpture of the carapace is of the type found in D. fcr.estrata and in the figure of the under surface there appears to be an indication of a tympanum on the second segment of the abdominal sternum, the third segment not being represented. The only discrepancy is that D. clepsydra possesses a tooth at the proximal end of the lower surface of the merus of the €heliped. In males of D sulcata this tooth may be present or absent, but its existence is not meiiiioned in an}^ description of D. fenestrata. Of this species, which is restricted to the southern and eastern coasts of Africa, I have seen no specimens. It has been recorded from Zanzibar (Aurivillius, Lenz), Ibo (Hilgendorf), Mozambique (Hilgendorf, Miers), Inhambane (Hilgendorf), Durban Bay (Steb- bing) and the Cape of Good Hope (Ortmann). Dotilla sulcata (Forskal). 1775. Cancer siilcatiis. For^-kal, Descript Aiiitn., p. 92 (Hauniaei. i.S()(>. Myctiris stilcatas, Audouin, Descript. de VEgypte, Hist. Nat., 1, Bxplic. soiuniaire des planches, p. 8l; Sa\igny, ibid., Planclies. Crust., pi. I, figs. 3, i-i\- (1817). 1829-44. Myctiris sulcatus, Giierir,, Icon. Regne Aiiiiii., Crust., pi. i\-, Hg.s. 5, ^a-b. '.' Myctiris sulcatus, Milne- Kdwards, in C'lnier's Regiie Aiiini.. Atlas. pi. xviii, figs. 3, 3fl. b. I'^.l.v Ocypode (Doto) sulcata, de ^iaan, in Siebold's faun, 'fapon.. Crust.. p. 24. 1837. Doto sulcatus, Milne- Kdwards, Hist. nat. Crust. 11, p. 92. 1850. Doto sulcatus, Lucas, Hist. \nt. .Inii/i. Artie, Crust, p. 6i,pl.ii, fig. I. i86i. Doto sulcatus. Heller, Fif^. Kais. Akad. Wiss. Wicn XLIII, p. 361. 1888. Dotilla sulcata, de Man, Jourii. Linn. Soc , Zool. XXII, p. 130. 1889. Doto sulcatus, Cano, Boll. Soc. Nat. Napoli III, p. 249. 1892. Dotilla sulcata, de Man, in Weber's Zool. Ergebii. Reise Nied. Ost- Iiid. 1 1, pp. 309-13. 1900. Dotilla affiiiis, .\lcock, Jourii. Asiat. Soc. Bengal 1..XIX, p. 365, and niustr. Zool. 'Investigator,' Crust., pi. Ixiii, figs, i, \a, b. 1906. Dotilla sulcata, Nobili, Ann. Sci. nat., Zool , (9) IV, p. 315. H)i5. Dotilla sulcata, Laurie, Journ. Linn. Soc, Zool. XXXI, p." 467. I agree with Nobili and Laurie that D. affinis is synonymous with D. sulcata. The tooth at the proximal end of the lower surface of the male cheliped is well developed only in large in- dividuals ; the types of Alcock's species are all small, but the tooth 1919-] ^^- Kemp : Notes on Crustacea Dccapoda. 329 is present in a rudimentary condition in the two largest males. In a series of five specimens recently obtained by Capt. R. B. Seymoui Sewell, I. M.S., in the Gulf of Suez, the tympanum on the upper surface of the last leg is present in two very small specim.ens and in a female of medium size; in a small male and large female it is altogether absent. The specimens examined are: — i-V-^ Red Sea. Ik-rlin Mus. Three. - V - Aden and Mekran coast. ' Inve.stigator.' Tvi^Es l'\)ur. of D.'affiiiis, .Mc. ''^«-' A'm Miisa, ChilF of Sue/. R. B. Seymour Sewell. f^ve. Other precisely localized records of D. sulcata are, — Suez (Forskal, Laurie), Tor (Heller), Aden (Nobili) and Djibouti (Nobili) Dotilla pertinax, Kemp. 1915. Dotilla perliiKix, Kemp, Mem. hid. Mus. \', p. 222, pi. xii, fig. 4. Examination of further specimens shows that, as in D. sulcata^ the tympanum on the upper surface of the last pair of legs may be present or absent. This character, therefore, will not serve to distinguish the species from Nobili's D. iiialabarica, to which in the pattern of the grooves on the carapace it is clearly related. '^■-fp'^ Outer channel of Chilka Chilka Survey, March, Many (incUul- Lake, Orissa. Oct., 1914. ing Types i. ^i^'' Puri, Orissa. S. Kemp ; March, Seventeen. 1916. The specimens obtained at Puri were found at the edge of a small pool of brackish water separated by a sandbank from the open sea. At exceptional tides sea-water made its way into the pool. Dotilla malabarica, Nobili. 190^. Dotilla u/alabarica, Sub\\\. Boll. .U/is. Torino Will, .\o. 4^.', p. Jo. fig. 6. I have not seen this species, which is evideiitl}^ closely related to D. pertinax. It differs in the sharply p;mtagonal form of the gas- tric area — clearly shown in Nobili's figures, in the generally deeper sculpture of the carapace and in the absence of a trans- verse groove near the posterior border. The fingers also appear to be much shorter in relation to the palm and the dactylus of the last leg longer, twice the length of the propodus. On actual com- parison of specimens other distinctions will probably be dis- covered. Dotilla malabarica is known only from the original examples obtained at Mahe on the Malabar Coast (E. Deschamps coll.). I have endeavoured without success to obtain further specimens. Dotilla wichmanni, de Man. 1S9J. Dotilla wichmanni . de Man, in \Veber'.s Zool. Ei'gehn. Reise Nied. ()st.-I)!d. II, p. ;,oS, pi. xviii. fig. 8. 1S95. Dotilla rviclimanni, de .Man. Zool. Jalirb.. .Sy.^t.. \'III. p. 577- 330 Records of the Indian Museum. [Vol. XVI, 19IC). Dotilla iviclinunmi, Kathbun, Daiisk. Vid.Selsk.Skrift. (7), iiaturvi'd. og viatli., V, p. 324. IQ18. Dotilla wic/imanni, Tesch, Decap. Bracliyiir. 'Siboga' Exped. I, P- 45- ^ . ' IQ18. Dotilla wiclniiaiiin, Kemp, Mem. Asuit, Sac. Bengal \ I, p. 227, le\t-fig. 1. In the last-quoted paper I have given an account of a series of very large specimens obtained by Dr. Annandale in Ivower Siam. Large males from this locality exhibit strong secondary sexual characters in the presence of certain angular projections on the sides of the carapace, the most conspicuous being spinose in cha- racter and situated beneath the outer orbital angle. There is also in the fully developed male a prominent compressed tubercle on the inner face of the carpus close to the meral articulation. Tesch notes the presence of two tympana on the outer face of the merus of the chelipeds ; both are distinct in the specimens I have seen and a similar character is frequently, but not always, met with in D. intermedia. In the conformation of the grooves on the carapace D. wich- manni differs markedly from any other species of the genus. In the form of the lateral grooves it shows affinity with D. blanfordi and D. intermedia but otherwise there are few points of resem- blance. Apart from D. mydiroides it is the only species which pos- sesses tympana on all the segments of the abdominal sternum.' ~\^~ Kaw Deng, near Singgora, N. Annandale; J^n.. Thirty-one. Gulf of Siam. 19 16. «iAi Corbyn's Cove South, Port S. Kemp ; March, 1915. Sixty-five. Blair, Andamans. The specimens from Port Blair are all small and thesecondai}^ sexual characters of the males are not developed. One of Dr. Annandale's specimens is ovigerous. The species has been recorded from Celebes, Makassar and Atjeh in Sumatra (de Man), the Talaut Is. (Tesch) and from Koh Kong in the Gulf of Siam (Rathbun). Dotilla blanfordi, Alcock. I9()(). Dotilla blanfordi, Alcock, 'Journ. Asiat. Sac. Bengal l.WSi, p. 366, and lllitstr. Zoo/. 'Investigator.' Crust., pi. Ixiii, figs. 3, 3^?. We are indebted to Lieut.-Col. H. J. Walton, I. M.S., for further examples of this species, which like most other Scopimc- rinae appears to be local rather than rare. The additional speci- mens are considerably smaller than the types ; the carapace of the largest male is only 4*2 mm. in length and that of the single ovi- gerous female only 3*0 mm. In the sculpture of the carapace this species shows affinity with D. intermedia, a form which appears to be restricted to the Bay of Bengal. ' For my observations on this point see the paper cited above. iQig.J vS. Kemp : Nu/es on Crustacea Decapoda. 331 i-^:ji'-^ 7 Bombay and Karachi. A. O. Hume, F. Day and Four, Tvhes. afga j " W. T. Blanford. af§'' Orau I., Bomb.ay. H.J. Walton ; April. May, Thirty. eiyht. i(.)iS. Not known from an}^ other locality. Dotilla intermedia, de Man. 1888. Dotilla infeniiedi/i, de Man, Joiii'ii. LiiDi. Soc. ZooL, XXH, p. [^5. pi. ix, figs. 4.-6. 1900. Dotilla clepsydrodactyhts. Alcock, Joittni. Asiaf. Soc. Bengal I, XIX, p. 367, and Illitstr. Zool. Investigator, Crust., pi. Ixiii, figs. 2, 2a. 1915. Dotilla clepsvdrodactylns, Kemp, Mem. Ind. Miis. \' , p. 226. Examination of a very fine series of specimens, recently col- lected by Dr. F. H. Gravely at Chandipur inOrissa, has convinced me that D. clepsydrodaciylus is synonymous with D. intermedia. I have seen the types of both forms and find that the configura- tion of the grooves of the carapace is identical. D. intermedia was described by de Man from a number of small specimens ^ in which the characters of the adult male chela were not developed. Altogether I have examined 316 specimens of this species, of which 235 (148 males and 87 females) were obtained by Dr. Gravely at Chandipur on the Orissa coast. Among the males from this locality two very distinct dimorphic forms occur, which may be termed ' high " and '' low." In the " high " male, which is the type described by Alcock, the first abdominal sternum bears a sharp transverse ridge on either side of the trough formed to receive the terminal segment of the abdomen and well behind its anterior limit. The fingers of the chela each bear a large lobe or tooth near the middle of their prehensile edge. The copulatory appendage is blunt at the tip and furnished with numerous setae. In the " low " male the first abdominal sternum bears ante- riorly a pair of large outstanding triangular teeth ; these are in advance of the anterior limit of the abdominal trough and are thus placed considerably further forwards than the ridges in the " high" male. The dactylus of the chela bears a low rounded lobe near the base of its prehensile edge (further back than in the " high" male) and there is no lobe or large tooth on the fixed finger. The copulatory appendage is more slender, strongly sinu- ous, and terminates in a fine point which is turned inwards and does not bear conspicuous setae. That these two types of male belong to the same species is, I believe, incontestable. In the form and areolation of the carapace they resemble each other exactly and they were, moreover, all found in the same locality. ' De Man described the species from 32 specimens, "all males." Of these 14 are in the collection of the Zoological Survey of India, labelled •' types " in de Man's handwriting. De Man was mistaken as lo the sex ot his specimens, for 7 of those examined are females. 332 Records of the Indian Museum. [Vol. XVI, All well-grown males can be referred without the least hesita- tion to one or other dimorphic form ; the " high " males reach a larger size, the carapace being sometimes as much as 5"5 mm. in length, whereas the ' low " males rarely exceed 45 mm. In speci- mens of medium size the characters of the sternum and cheln are less well developed, though as a rule perceptible, but in very small in- dividuals, from 2"0 to 3'0 mm. in length, it is usually not possible to detect them. The form of the copulatory appendage appears, Text-fig. 10. — Dofilla intermedia, tie Man. a. Chela of " high " male. d. Copulatory appendage of "high" h. Chela of " low " male. male. c. Copulatory appendage of "low" e. Abdominal sternum of "high" male. male. /. Abdominal sternum of " low " male. however to be quite constant ; I have examined it in all the speci- mens and have never once been in doubt. At Chandipur Dr. Gravely collected specimens on three occa- sions, the numbers being as follows : — " Hi^-h" males. " l.ow" males. b\Mnales. June, 1915. ' 17 ^ 15 (I ovig.) May. 1916. 46 18 -39(1/ ov'g.) May, 191 7. 41 20 33 (3 ovig.) 104 44 87 IQIQ-I ^^- Kemp : Notes on Crustacea Decapoda. 333 It seems therefore that "high" males are very much com- moner than " low" males, and that males (both forms included) are nearly twice as abundant as females.' I am not at all certain as to the meaning of the dimorphism in this species. Of both types of male there is a series ranging from very small to full-grown specimens, a fact which perhaps discounts the possibility that they represent breeding and non- breeding phases. On the other hand it is very improbable that more than one type of copulatory appendage can be employed in the sexual process. In other species of Dotilla the appendage is gen- erally blunt at the tip, resembling that of the '" high " male, a cir- cumstance which points to the conclusion that the '' low" males do not breed. The examples of D intermedia that I have seen from other localities are mostly of small size and (determined mainly by the form of the copulatory appendage) consist entirely of "■ high " males and females. Several observations indicate that environment has a great influence on species of Dotilla, its effects being shown both in the size of the specimens and in the degree of development of the secondary sexual characters of the male. Thus the individuals of D. intermedia that we obtained in the outer channel of the Chilka Lake in Orissa were all small and it was onh' with difficulty that a few specimens were obtained which showed in an imperfect degree the peculiar character of the '' high " male chela. In this locality with its extreme seasonal changes in salinity, there can be little doubt that the environment is unfavourable. A somewhat similar instance has been noticed in D. wichmanni (see p. 330). At Chandipur it is clear that the environment is peculiarh' {■SiYOVLXohle iox D. intermedia and that "low" males were found here and not in any other place in which the species has been collected, is perhaps in some way correlated with this fact. The following specirnens have been examined : — Sullivan I., Meroui Ar- Mas. Collr. Foiuleen. chipelago. 'I'VPES. ±38j:i;5 False Point. Orissa. ' Investigator.' Types of D. clepsydi'oihic- fyliis, .Ale. Se\cn. S93i) 1 0 Outer Channel, Chilka Chilka Survey; March. Thirty-five, Lake, Orissa. 1914. 9 19 1 10 Eimur backwater, nr. Madras. N. .\nnandale. Twenty (]u\'.). 9 1 9 2-3 1 0 Chandipur, Bala so re. F. H. (iravely : June Two hundred Orissa. IQ15 ; Ma}-, 1016; and thirt\ - Ma\-, 191 7. five. 9.S (i(i 10 Maungma-gan. Tavo\-, Burma. j. Coggin Brown. Fi\e. The species has not been recorded from any other locality. 1 The abdomen in the genus Dotilla shows little difference in outline in males and females. In determining the sex it is therefore necessary to examine the pleopods, unless the specimens are ovigerous or with the male secondary characters strongly developed. 334 Records of the I ndiaii M useitin. [Vol. XVI, Genus Dotillopsis, nov. Text-fig. ii.— Dotillopsis hre^'. farsis (de Man). Endopod of second maxilliped. This genus, which is established for Dotilla brevitarsis, de Man and D. p}ofuga, Nobili, may be recognised b3' tlie following com- bination of characters : — The carapace is cuboidal rather than globose and deeply grooved above. The side- walls possess the deep convolute sculpture seen in Dotilla. The penultimate segment of the second maxilliped is but little expanded and the ulti- mate segment is terminal in posi- tion. The merus of the outer maxilliped is longer than the ischi- um and IS gyrous-sulcate. The meral segments of the legs bear ill-defined tympana. In the first three pairs of walking legs the me- rus, carpus and propodus are dense- ly tomentose inferiorly. The ab- domen consists of seven distinct segments ; the fourth segment does not overlap the fifth and does not bear a brush of hairs at its distal end. In the male the fifth, sixth and seventh segments are narrow, the fifth not deeply constricted ; the fourth segment is greatly expanded and produced on either side, its breadth being nearly three times that of the fifth. In the female the abdomen is broadly oval. Type. — Dotilla brevitarsis, de Man. The genus is in some respects intermediate between Dotilla and Tympanomerus : it agrees with the former in the deep sculpture of the upper surface and lateral walls of the carapace and with the latter in the structure of the ultimate segments of the second maxilliped. The abdomen differs altogether from the very characteristic type found in Dotilla ; in the male it shows signs of considerable specialization and has little resemblance to that found in any other genus of the subfamily. The presence of a dense tomentum on the first three walking legs, a character also found in a few species of Tympanomerus , is almost certainly an adaptation to environment ; the species of Dotilla are in my experience always found burrowing in clean firm sand, whereas Dotillopsis brevitarsis lives in the softest mud. Nobili's D. profuga, which I have not seen, probably also lives in mud, being described from the Upper Sadong River in Borneo. The two species of the genus may be distinguished thus ; — Sculpture of carapace .sharp ; frontal groove continued almost to posterior margin ; palm with conspicuous longitudinal carinae on its lower and inner aspects Sculpture of carapace indistinct ; frontal groove reaching only to gastric region ; palm without longitudinal 1. II /). brevitarsis. D. profiign. igig.J ,S. Kemp : Notes on Crust acea Dccapoda. 335 Dotillopsis brcvitarsis (de Man). iS8S. Dofillii hrevltarsis, de Man, yourii. Linn. Soc, Zoo!.. XXII, p. 1,^0, pi. ix. tigs. 1-3. K)o(). Dotilla bi-cvitai'sis. Aicock, ^7""''"- Asiat. Soc. Bengal l.XIX, ]). 367. Plate XIII, fig. I. A number of additional specimens of this species have recent- ly been obtained in the Gangetic Delta. The species was found at Port Canning and near the junction of the Matlah and Biddah rivers, living between tide-marks on a bank of exceedingly soft mud. The crab appears to have habits similar to those of the species of Dotilla] but, owing to the semiliquid consistency of the mud, the burrows do not retain their form and the pellets brought to the surface rapidly disappear. On one of the occasions on which specimens were obtained, in December 1916, the water was brackish, its specific gravity (corrected) being about i'oro5. I have nothing to add to de Man's excellent description, but Text-fig. 12. — Dotillopsis brevitarsis (de .Man). Abdomeu of male (left), of female (right). give a fresh figure of the animal (pi. xiii, fig. i) and outline drawings of the second maxilliped (text-fig. 11) and of the abdo- men in each sex (text-fig. 12). In adult males the carapace is grey, white above the bases of the legs and on the outer maxillipeds. The chelipeds are entirely bright orange red except for the upper surface of the carpus, which is grey. The walking legs are grey at the base, with the two terminal segments pure white. In the first three pairs there is a large red or orange-red patch on the anterior sur- face of the merus and, in the first two pairs, a similar patch on the posterior surface of the same segment. Adult females are similarly coloured, but frequently with orange instead of red or orange-red pigment and with the colour less pronounced on the walking legs. The eggs are deep reddish-purple, turning 3^ellow in spirit. In the largest specimen obtained the carapace is about 8 mm. in length and iO"5 mm. in breadth. 336 Records of the Indian Museum. [Vol. XVI, —^^-- McroLii Archipelago. Mus. C'ollr. Three (frag- mentary). 2.5_7.s Diamond I., off ('. Negrais, ' Investigator.' One. Burma. 9«oi-.5. Kaikal Maree, nr. junction S. Kemp; Dec, iai6. Kightw. of Matlah and Biddah Rs., Gangetjc Deha. 9S09 Matlah R., opposite Port Bengal Fish. Dept. (B. Seven. Canning, Gangetic Delta. Prashad) ; March, 191 8. The species is not known from any other locaUt^^ The fragmentary specimens from the Mergui Archipelago appear to be paratypes. Dotillopsis profuga (Nobili). 1903. Dotilla profitga, Nobili, Boll. Mits. Torino XVUI, Xo. 447, p. 22. Upper Sadong R., Borneo. Genus Tympanomerus, Rathbun. 1835. Cleistostoma, de Haan, in Siebold's Faun. Ja^on., Crust., p. 26. 1888. Dioxippe, de Man, 'Journ. Linn. Soc, Zool., XXII, p. 137 (noiii. praeocc). 1897. Tympanomenis, Rathbun, Proc. Biol. Soc. Washington XI, p. 164. 1900. Tympanomerus, Alcock, Journ. Asiat. Soc. Bengal LXIX, p. 371. 1918. Tjmpano}nerns, Tesch, Decap. Brachyiir. ' Siboga' Exped. I, p. 48. This genus shows signs of affinity with Scopimera in the form of the abdomen and in the presence of accessory branchial passages between the bases of the walking legs. It differs, however, from both Scopimera and Dotilla and resembles Dotillopsis in the form of the ultimate segments of the second maxilliped From Dotil- lopsis it is readily distinguisl'jed by the absence of convolute grooves on the side- walls of the carapace, by the much less strongly sculptured dorsal surface and by the less broadly expanded fourth segment of the male abdomen. Tympana, which are uniformly found in all other Scopimerinae, are sometimes absent in species of this genus ; when present, they are usually ill-defined and difficult to observe. Tesch has drawn attention to the presence of hairy-edged pouches or orifices of accessory branchial passages in species of this genus. In both T. ceratophora and T. integer he found two pairs, situated between the bases of the first and second and the second and third walking legs. I have found these pouches in T. pusillus, T. Imgulatus and T. stapletoni, — in the last-named species they occur between the third and fourth legs also. In five other forms that I have examined the tufts of hair are absent or very poorly developed and I am not satisfied that accessor}^ branchial passages exist. Stimpson's genus Ilyoplax, which cannot be identified with certainty until the type species has been rediscovered (see p. 310), is evidently related to Tympanomerus and it seems very probable that the two will prove to be synonymous. Should this happen IQIQ-J v'^. Kemp: Notes on Crustacea Decapoda. 337 the unfortunate term Tympanomerus will disappear from nomen- clature, for Ilyoplax has long priority. The species may be distinguished thus : — I. Eyestalk without projecting- terminal style. A. Carpus of cheliped without a tooth on its inner aspect. [Carpus short, its upper surface about i^ times ns long- as broad.] 1. Carapace pentagonal, the orbits being decidedly oblique; outer surface of palm granular or with squamiform rugosities. a. Lateral border of carapace notched behind outer orbital angle; male abdomen with all segments distinct, distal angles of 4th segment not pro- duced. i. Granules on outer surface of palm arranged in a reticulate manner ; a strong- crenulate carina on outer side of both fingers; fixed finger horizontal in relation to pah-n ; meri of walking legs with large tympana on underside ... ..." .. T. piisillus. ii. Ciranules on outer surface of palm not ar- ranged in a reticulate manner ; no carinae on outer sides of fingers; fixed finger bent downwards in relation to palm ; meri of walking legs without tympana . T. pliilippineiisis. b. No notch on lateral border of carapace behind outer orbital angles ; 4th and 5th segments of male abdomen fused, distal angles of 4th .seg- ment produced and acute. [No carinae on outer sides of fingers ; meri of walking legs with conspicuous tympana] ... ... T. integer. 2. Carapace quadrilateral, the orbits being- almost or quite transverse ; outer surface of palm quite smooth or with very inconspicuous microscopic granules near lower border. a. Front narrow, less than one fifth anterior breadth of carapace; a well-defined groove on side-walls of carapace extending from anterior angles of buccal cavern to base of penultimate legs; abdomen of male with 5th segment only a little constricted, 7th broader than long. [Lower surface of palm flattened and bordered by carinae.] i. Front not more than one eleventh anterior breadth of carapace; upper surface of cara- pace not wider at the middle than anteriorl)'; chela of adult male weak, similar to that of female ; male with a patch of tonientum on carpus and propodus of 2nd walking legs T, sfevensi. ii. Front not less than one seventh anterior breadth of carapace; upper surface of cara- pace wider at the middle than anteriorlv : chela of adult male strong, dissimilar to that of female ; male without tomentum on 2nd walking legs .. ... ... 7'. /■'rater. />, hront broader, more than one quarter anterior breadth of carapace; groove on side-walls of carapace visible only near angles of buccal cavern ; abdomen of male with 5th segment deeply constricted, 7th at least as long as broad, i. -Anterior breadth of carapnce less than lA times its length; front angular at sides; crest defining lateral border of carapace discon- 33^ Rccoyds of /he huiian Muscuni. [Vol. XVI, tiiiuous posteriorly ; outer surface ot" palm without a carina, its upper border rounded 7". stupletuiii. ii. Anterior breadth of carapace more than li limes its leno;th ; front rounded ; crest defin- ing lateral border of carapace continuous throughout its length ; outer surface of palm with a fine carina running to tip of fixed finger, its upper border crested ... T. desclmnipsi. B, Carpu.-, of cheliped with a tooth on its inner aspect. ^Front not less than one quarter anterior breadth of carapace ; male abdomen with 5th segment very slightly constricted.] [. Surface of carapace with numerous small furry patches ; carpus of cheliped short, its upper surface about 1 5 times as long as broad ; palm without carinae on Icwer surface ; fingers with large teeth in male ... .. ... T. /in^ii/afus. 2. Surface of carapace without furry patches ; carpus of cheliped elongate, its upper surface twice as long as broad; lower surface of palm bounded by fine carinae ; fingers without large teeth. a. Lower border of orbit with a large projecting lobe near its outer end ; lateral margin ot carapace sinuous ... ... . . T. orientatis. l>. Lower border of orbit without a projecting lobe ; lateral margin of carapace regularly convex . T. gaiigeticus. II. Kye.stalk with a long terminal style projecting far beyond cornea. [ Front about one fifth anterior breadth of carapace ; orbits oblique; lateral border concave; carpus of cheli- ped elongate I ... ... ... ... T. ceratopliora. Koelbel has suggested that T. ceratophora should be placed in a separate subgenus, T. methypocoelis , but I do not think this necessary. Of the eleven species I have seen all but T. philippinensis, T. integer and T. ceratophora. T. stevensi, T. jrater, T. stapletoni, T. orientalis, T. gaiigeticus and T. lingulatus are Indian species. Tympanomerus pusillus (de Haan). 1S35. Ocypode {Cleistosfoina') piisilla, de Haan. in Siebold's Faun. Jnpoii.. Crust., p. 56, pi. xvi, fig. i. 1852. Cleistostoma piisilla, Milne-F.dwards, Arm. Sci, nat.. ZooL, (3) XVIII, p. 160. 1888. Dioxippe pusilla, de Man, Joui'ii. Linn. Soc, ZooL, XXII, p. 137. [88g. Dioxippe piisitla, de Man, ZooL Jalirb., Syst., IV, p. 447. ig()2. Cleistostoma pnsiliinn, Doflein, Ahh. math.-phys. Classe K. Baver ylA-^rt'. Wiss. XXI, p. 667. "To' Japan. |. Anderson (/)('?' J. G. de Man). Two. Tympanomerus philippinensis, Rathbun. 1OI4. Tympanorne 'US philippinensis, Rathbun. Proc. U.S. Xat. Mas., XLVII.p. 84. Guijulugan, Negros, Philippine Is. Tympanomerus integer, Tesch. 1918. Ty?npniiomerus integer, Tesch, Decap. Brachyur. ' Siboga' Exped. I, p. 54, pi. iii, fig. I. Kur I.J west of Kei Is., Banda Sea. I9I9-J •^- Kkmp : Notes on Crustacea Decapoda. 339 Tytnpanomerus stcvcnsi, sp. nov. Plate XIII, fig. 2. The carapace is transversely oblong; the anterior breadth is about one and a half times the length and the depth about half the breadth. The upper surface is slightly convex in both direc- tions and is vcrv feebly sculptured. A broad and inconspicuous median furrow extends backwards from the base of the rostrum, disappearing before it reaches the middle of the gastric region and there is a shallow transverse depression on either side some distance behind the orbital border. The posterior limit of the gastric region is defined by a well-marked transverse groove about one third the breadth of the carapace. On the branchial regions there are a few minute tubercles, bearing short setae, arranged in three oblique rows. The two anterior rows are exceedingly short and indistinct and frequently consist of onl^^ one or two tubercles each. The most posterior of them is longer and more conspicuous ; in direction the row is as much longitudinal as transverse, and if it were continued forwards the line so formed would pass through the front. In this respect a marked difference exists between T. slevensi and the closely allied T. jrater. Posteriorly the carapace is traversed by a sharp and perfectlv straight transverse ridge, situated nearer the hinder margin than in T. stapletoni and T. deschampsi. The front is obliquely deflexed and at the apex is broadly rounded or with a very obtuse median point ; its lateral borders are slightly but distinctly constricted near the base. The breadth of the front is only one eleventh or one twelfth the breadth of the anterior border of the carapace and is thus much narrower than in any other species of the genus. The orbits are very slightly oblique, much less so than in T. pusillus, but not strictly transverse as in T. stapletoni. The upper orbital border is microscopically beaded ; it is excavate near the base of the front, but in its outer half is almost perfectly straight. The lower border is a little sinuous in dorsal view and is finely crenulate. On the floor of the orbit there is a crest that extends throughout nearly the whole of its length ; it runs close to the lower border and the space between the two is hollowed. The outer orbital angle consists of a small acute tooth directed out- wards. The lateral margins of the carapace are ver}^ slightly conver- gent posteriorly and are straight, not convex ; the breadth of the upper surface in the middle is thus a little less than its anterior breadth. There is a small emargination or notch behind the outer orbital angles and further back a series of minute denticles. Throughout its length the margin is defined as a sharp crest bearing short setae. At the extreme posterior end, as in T. pusillus , it is bifurcated, one branch running to the margin at the base of the penultimate legs, while the other — the more conspicuous of 340 Rccoyds of the Indian Museum. [Vol. XVI, the two — trends inwards in a sinuous cuive and terminates in a small angular lobule bearing a tuft of setae, immediately above the base of the last pair of legs. There are minute tubercles, sparsely distributed, on the anterior part of the side-walls of the carapace. A conspicuous groove runs from the anterior angles of the buccal cavern to the base of the penultimate legs.' The antennules and antennae do not differ appreciably from those of T. pusillus, but the epistome is shorter and the broadly triangular median tooth that separates the distal ends of the outer maxillipeds in other species is here exceedingly narrow. The buccal cavern is nearly one and a half times as broad as long and is completely closed by the external maxillipeds (text- fig. 13). The ischium of the latter appendages is subquadrate with a setose line extending obliquely across it near the anterior border. The merus is a trifle shorter than the ischium and is broader than long. It bears a a -shaped furrow anteriorly as in T. stapletoni; it is, however, grooved near its inner edge, with the margin reflected upwards and in the proximal half there is a shallow median furrow which runs forward between the termina- tions of the A . The surface of the merus is smooth and shining. The exopod is entirely concealed and is furnished with a long slender flagellum. The chelipeds of the male are weak, very little stouter than those of the female, and decidedly less than twice the length of the carapace. The merus is trigonal with microscopically beaded edges ; it bears a tympanum internally and sometimes, but not always, another of larger size externally. The carpus is short and smooth without a tooth on its inner aspect; the inner margin of the upper surface is crested and beneath it there is a tuft of very long hairs. The chela (text-fig. 14) is slender, nearly three times as long as the greatest height of the palm and the fingers are more than one and a half times the length of the upper border of the palm. The latter bor- der is crested and microscopically crenulate; parallel with it on the inner face there is a longitu- dinal row of setae. From the tip of the fixed finger four finely beaded carinae run backwards on to the palm. The two median ridges are parallel and disappear before reaching the middle of the lower surface ; the innermost curves obliquely upwards J EXT-FiG. 13. — Tyuipanonienis stevensi, sp. nov. Third maxilliped. ^ In thi.s rt'spectthe species resembles T. f rater. In T. pusillus, T. stapletoni, T. deschampsi, T. gangeticus and T. orientalis llie i^rooxc is inconspicuous and is visible onl\' in the anterior part of its course. IQIQ.] vS. Kemp: Notes on Crustacea Decapoda. 341 across the inner face, while the outermost runs along the lower part of the outer surface and extends to the proximal end of the palm. Between these ridges there are a few extremely minute tubercles ; the re- maining portions of the palm, including almost the whole of the outer surface, are quite smooth. The fingers meet only in their distal third when the claw is closed ; their tips are curved a little inwards and are shghtly spatulate. The fixed finger is without teeth; the dactylus is ridged above and bears a low crest of minute teeth in the proximal half of its prehensile edge. I'f.xt-fiCt. 14. Tvmpai!0)iu')'iis steveiisi , sp, nov. Chela of male. I'ext-fig. 15. — Tynipaiioiiu'i-iis stevciisi, sp. nov. Abdomen of male (left), of female (right). In females the chelipeds are a little more slender and the fingers are full}'- twice the length of the upper border of the palm. The palm is crested above with the row of setae on the inner face as in the male ; but on the lower side there are only two carinae, enclosing a flattened lower surface, and each of these carinae bears long setae. The fingers are more distinctly spatulate than in the male ; they gape widely at the base and there is no denticulate crest on the dactylus. The third or penultimate pair of walking legs is the longest, nearl}' two and a half times the length of the carapace. There are well defined tympana on the upper and lower surfaces of the meri of the first two pairs and on the lower surface of the last two. In the proximal half of the merus of the two intermediate pairs, on the dorsal surface, there is a finely crenulate ridge run- ning parallel to the upper border. The edges of the meri are finely spinulose, a feature specially well marked on the posterior borders of the second and third pairs. In the.se two pairs the carpus 342 Records of the Indian Museum. [Vol. XVI, and propodus each bear two carinae on their superior faces ; the dactyli are flattened and in every instance shorter than the propodi. In large males there is a dense patch of tomentum on the second walking legs, extending from the middle of the carpus to the distal third of the propodus ; in 3'oung males and females no trace of this tomentum can be found. The basal segments of the legs bear long plumose setae which retain fine particles of mud. The second segment of the abdomen of the male (text-fig. 15) is narrower than the first. The third and fourth are sepa- rately rounded at the sides and about as broad as the first, the fourth being a little the longer. The fifth segment is rather more than half the breadth of the fourth and is only slightly constricted near its proximal end ; at its narrowest point it is broader than long. The sixth segment is twice as broad as long and is a little wider than the fifth ; the seventh is triangular, broader than long and rounded distally. The abdomen of the female (text-fig. 15) is much broader than that of the male but is comparatively nar- row at the base ; the fourth segment is the broadest ; the seventh is triangular in shape and variable in its dimensions. In the largest male the anterior breadth of the carapace is 77 mm., its breadth 5'i mm. and the breadth of the front about o"65 mm. In a large female these measurements are respectively 7*0, 4*7 and o"6 mm. The specimens are of a bluish-grey colour in spirit. "'-i-n-- Ivarachi. C. R. Stevens ; March. Twenty-eight. May, 1917. One of the females is ovigerous. The types bear the number 9796/10, Zool. Surv. Ind. Tympanomerus frater, sj). nov. This species is very closely allied to the preceding and differs from it onl3" in the following particulars: — (i) The carapace (text-fig. 16) ^^ / is in most respects closely simi- \ ^ ^ lar to that of T. stevensi ; but ^j^^^^^^^^j^j55-^>^^ ^j_^^ lateral borders are slightly ^0^ ^^^^ ^'^d evenly convex, with the re- 1^-"-/^ ^•^f'; suit that the breadth across the 1 ^ I middle is decidedly greater than , : \. that between the outer orbital ^N^ ; - v .y angles. V _ . .^^^ .>" (ii) The front is very much ^^"^ broader, between one sixth and Text-fig. 16.— Tjmpdi/nmerus One seventh the anterior breadth; frater, sp. no\ . its lateral borders are a little Carapace convergent anteriorly, not con- stricted as in T. stevensi. (iii) The upper orbital border is decidedly sinuous and is conspicuously concave in its outer half. 1919-] ^- Kemp: Notes on Crustacea Decapoda. 343 (iv) The oblique rows of tubercles on the branchial region are better developed than in the allied form and the most posterior of them is more transverse than longitudinal ; if the line formed by this row were continued forwards it would cut the outer end of the orbital border on the opposite side. (v) The chelae of the male (text-fig. 17) are strongl}- developed, much deeper and longer than '^'f.^y-vw.. \].—Tymtyanomerus f rater, s^.nov. those of the female. Chela of male. (vi) In addition to those mentioned in the description of T. stevensi there is a large tympanum on the upper surface of the merus of the penultimate walking legs. (vii) The borders of the meral segments of the walking legs are microscopically beaded, not spinulose as in the allied species. (viii) There is no tomentum on the carpus and propodus of the second walking legs of the male. (ix) A fringe of dark brown bristles, not found in the preceding species, occurs on the edge of the sternum between each pair of walking legs. (x) The abdomen of the male closely resembles that of T. stevensi, but the fifth segment is proportionately a little longer and its sides are more sinuous. In all other respects the species are in the closest agreement ; notably in the presence of a groove extending from the edges of the buccal cavern to the base of the penultimate legs, in the cari- nation of the palm and subspatulate form of the fingers, and in the dorsal carinae on the two intermediate pairs of legs. The two species were, moreover, found together I was at first of the opinion that two forms of a single species were represented ; but the differences, though many of them are small, are too numerous to admit of this possil^ilit}'. I have been able to separate even the youngest specimens without any great difficulty and have seen adult males and females of both species. In an adult male of T. frater the anterior breadth of the cara- pace is 5-6 mm., its length 4-0 mm. and the breadth of the front about 0'9 mm. In a female these measurements are respectively 5-0, 3*6 and 0'8 mm. and in another female, which is ovigerous, 5-0, 3-5 and 075 mm. The specimens are of a bluish- grey colour in spirit, sometimes rather darker than T . stevensi. ^m;- Karachi. (. K. Slewivs ; March, May, njij. Twcniy-six. Four of the females are ovigerous. The types bear the num- ber 9861/ 10, Zool. Surv. Ind. 344 Records of the Indian Museum. [Vol. XVI, Tympanomcrus stapletoni, de Man. igo8. Tympanoincvus stapletoni, de Man, Rec. hid. Miis. II, p. 212, pi. xviii, figs. I , \a-e. This species has been found at a number of additional locali- ties in Bengal and is quite common on the banks of the Hughli river at Calcutta. It is evidently an estuarine form and seems to occur only in places near or a little beyond the limit of tidal in- fluence. At Calcutta the water of the Hughli is frequently quite fresh, but under favourable conditions a slight admixture of salt is to be found up to a point some little distance above the town. The colour of living specimens agrees in general with de Man's description, but the carapace is frequently of a grey or dull gre}^- green colour and in the male the fingers of the chelae are orange and the last abdominal segment white. The species is known only from the Gangetic delta : — ■'^^ '( Jhalakati, Backergunj dist., H. P.. Stapleloii. Many, includ- ■if^i ] Bengal. ing Types. i "i"o~ Kanaigunj, Backergunj dist., ,, Six. Bengal . ^\%^ Banks of Passur R., Khulna, l^engal Fish. Depl. (B. Forty. Bengal. Prashad) and S. Kemp; Oct., 1917 ; July, 1918. §|§^ Banks of Hugfili R., near S. Kemp. " Many. Calcutta. (Sibpur, .Shali- mar, Budge-Budge and Takta Ghat.) All the specimens are from small burrows in the mud between tide-marks. Tympanomcrus deschampsi, Rathbun. 1913. Tynipaiionienie ih's< hampsi , Ratbbun. Proc. i'.S. .\nf. M/is. XIAT, p. 356, pi. xxxii, pi. xxxiii. fig. 1. IQ18. Tympauoiiiei'us deschainpsiy Kemp, Mem. .Isiuf. Soc. Bengal \ , p. 228. ^yfy~ Banks of W'hangpoo R.. 5-10 miles .\. .Xnn.indale. One. below Shanghai. Described by Miss Rathbun from Shanghai. Tympanomcrus lingulatus (Rathbun). 1909. Cleistosfoina lintruldtiini. Rathbun, i'roc. Biol. Soc. Wasliingfon XXII, p. 108. 1910. Cleistostoina lingiilafii/n , Rathbun, k'. Danske \'idensk. Sehk. Skriff. I J), natuivid. ogmafli., V, p. 323, t(>xt-tigs. 7, 8. This species was described by Miss Rathbun from an imma- ture female found in the Gulf of Siam ; two adult males and an ovigerous female have since been obtained by the R.I. M.S. ' Investigator' in the Mergui Archipelago. There is. I think, no doubt that the species must be transferred to the genus Tvinpanomenis. The antennular flagella are minute I There seems to ha\e bec-n a mistake about the precise locality of these specimens ; on the label sent with them to de Man " Dacca " was certainly written, but information subsequently supplied by the collector showed this to be incorrect. iqig.] S. Kkmp : Notes on Cyustacca Decapoda. 345 and rudimentary, lying in small oblique pits close to the edge of the front and separated by a comparatively broad septum, as in Tympanomerns pusillus and other Scopimerinae. In the Macrophth alminae, to which the genus Cleistostoma belongs, the antennules are well developed, fold quite transversely, and the septum between them is very narrow. These characters constitute, so far as I am aware, the only really valid distinction between the subfamilies Macrophthalminae and Scopimerinae, for the tvmpana found in most species of the latter subfamily are ill-defined and occasionally absent in Tympanomerus. On comparing T. lingula- ius with Alcock's Cleistostoma dotillijonne the differences in the antennules are quite evident. The Mergui specimens of T. linguLatus agree very closely with Miss Rathbun's description, but her figure does not altogether succeed in conveying the characteristic appearance of the upper surface of the carapace. In the individuals I have seen the majority of the fine granules are aggregated into small clusters, varying a little in size and arrangement and each set with short dark brown bristles retaining mud. The carapace in specimens which have not been cleaned overmuch is, in consequence, seen to be covered with small furry patches, rather than with isolated granules as in Miss Rathbun's figure. The angle on the lateral margin of the carapace in front of its middle point is in reality more obtuse than in the figure, but it bears a setiferous patch which makes it look more prominent. The oval cavities above the edge of the front are very evident, the species differing in this character from any other known species of Tympanomerus. The prominent median tooth on the epistome is paralleled in T. slevensi and T. fraler. The chelipeds of the male are short. The carpus bears a strong tooth on its inner side as in T. gangeticus and T. orientalis ; it is, however, much shorter than in those species, its upper surface being only about one and a half times as long as broad. Above the tooth on the inner side there are some long setae, while on the upper surface there are some short brown bristles. The palm is swollen and its height is fully as great as the I'fxi-fig. 18. — 'Fympannmerui^ length of the upper border (text-fig. liu^rulatiis (Raihbun). 18). The outer side is smooth and Chela of male, convex ; inferiorly it is rounded, without any traces of the longitudinal keels found in many species of the genus. The upper surface is finely granular with scattered setae. On the inner side there is a huge blunt ridge which com- mences near the posterior end of the upper border and curves downwards and forwards to the l^ase of the fixed finger. The summit of the ridge is irregularly tuberculate and, in the area between it and the finger-cleft, there is a patch of long hairs. 346 Records of the Indian Mnseuin. [Vol. XVI, The fingers are longer than the upper border of the palm and meet only at the apices where they are provided with corneous tips and some setae. The dactylus is strongly curved ; it bears a large tooth close to the base and another, not quite so large, near the apex; between the two there are some smaller teeth. The dentition of the fixed finger is similar, the teeth being in advance of those on the dactylus ; the proximal tooth is very large and conical. In the ovigerous female the chelipeds are as shown in Miss Rathbun's figure; the carpus, however, bears a small acute tooth on its inner side. The meral segments of the walking legs bear thickly setose patches, resembling tubercles, as described by Miss Rathbun. In addition, the upper surfaces of the meri, carpi and propodi are rather closely covered with brownish hair in males, while in the same sex on the underside of each merus there is a thickly felted patch. In the abdomen of the male (text-fig. 19) the suture between the third and fourth segments is exceedingly fine and inconspicu- ous, suggesting that the segments are not separabl}^ movable. The first and second segments are very short, and, though broad, do not nearly fill all the space between the last two pairs of legs. The second and third segments taken together are a little longer than broad with gently curved sides that converge strongly anteriorly. The fifth segment is about as long as its distal breadth, much narrower than the base of the third, and is very inconspicuously contracted at its proximal end. The sixth is broad- er than long and the seventh about as long as broad, with a broadly rounded apex. In the larger of the two males the greatest breadth of the carapace is 5-4 mm., its anterior breadth 4-8 mm. and its length about 40 mm. In the ovigerous female the greatest breadth is 5-2 mm. T. lingulatus appears to find its nearest allies in T. orientalis (de Man) and T. gangeticus, sp. no v., agreeing with these species in the possession of a strong tooth at the inner angle of the wrist. Text-fig. 10. — Tympanomerus lingulatus (Rathbun). Abdomen of male. Trotter 1., Mergui Archipclaoo. Jack and Una Is., Mergui Archipclaoo. ' Investigator." Two males. One female. The specimens were found in November 19 13 on a shore composed of mud and sand with larger boulders. That described 19^9-1 S. Kp:mp : Notes on Crustacea Decapoda. 347 by Miss Rathbun is from a mangrove swamp at Lem Ngob in the Gulf of vSiam. Tympanomcrus orientalis (de Man). 1888. Dioxippe oi'ientalis. de Man. 'Jonr/i. f.iiin. Soc. Zool.. XXI I. ]>. i v"^. pi. ix, figs. 8-10. iQiio. Tvnip/ii/oments orientalis. Alcock, Jouvii. Astai. Soc. Beiio,,/ I.XFX, P- 371. ^Li^ .Mergui Archipdago. iMus. C:ollr. Seven. P\K\rwF.s. Not known from any other localit}'. Tympanomcrus gangeticus, sp. nov. Plate XIII, tig. 3. This species, which is represented only by two specimens one of which is imperfect, is very closely allied to de Man's Tympano- merns orientalis, resembling that species in the possession of a strong tooth on the inner face of the carpus of the chelipedes. T. gangeticus differs from T. orientalis in only two conspicuous features : — (i) the lower border of the orbit shows no trace of the large obtuse lobe found near the outer end in de Man's species ; (ii) the crest defining the lateral borders of the upper surface of the carapace is regularly convex behind the small anterior ex- cavation, the upper surface being widest in front of the middle point. In T. orien- talis the crest takes a sinu- ous course ; it is distinctly concave anteriorly and is obtusely angled behind the middle, ^ the upper surface y^^.y,,^, ^o.-Tvmpanomerus ^rangeficus. being widest at this point. sp. nov. In other respects the dif- Chela of male, ferences are small The front is a httle broader, with its lateral angles more broadly rounded and its sides more oblique ; its apex does not possess a median point. The median groove on the upper surface is deeper and the front when viewed from above is more conspicuously emarginate distally There are numerous scattered setae on the lateral parts of the upper surface of the carapace. The buccal cavern is broader and the merus of the external maxillipeds is as broad as long (in T. orientalis it is longer than broad). The surface of the merus bears numerous very ^hoxt setae. The chelipeds are a little shorter : the length of the chela is considerably less than the anterior breadth of the carapace. The upper surface of the carpus is finely roughened and bears numerous minute granules antero-externally. The walking legs are a little shorter and stouter ; the merus of the penultimate pair is less than two and three quarter times as long as wide, whereas in specimens 348 Records of the Indian Museum. [\Oh. XVI, iqig.] of T. orientalis of similar size it is rather more than three times. The carpi and propodi of the first two walking legs are thickly coated with short woolly hair. The excavation in the lateral margin of the fifth abdominal seg- ment of the male (text-fig. 2i) is a little shallower and the distal parts of the same margin are less conver- gent anteriorly than in T . orienta- lis. The carapace of the type male is 4'0 mm. in length and 3"3 mm. in anterior breadth. In life it was uniformly grey in colour, with white lingers to the chelae and with dark spots on the merus, carpus and propodus of the walking legs. S. Kemp ; Dec igi6. Text- fic;. 21. — Tympauomcn/s gaiigcticiis, sp. iiov. Abdomen of male. l\;iikal Marce, near junc- tion of Matlah and Biddah Ks., Gang'etic delta. Matlah R., opposite Port ( anniny, Cianyetic delta. Benu-al |«ish. Dept. (B. Prashadi; March, 191 S. (^ne. TVPK. One. The water in both these localities probably contains some admixture of salt at all seasons. The specimens were found on banks of soft mud between tide-marks and the specific gravity of the water in the locality where the type specimen was taken was i'oio5 (corrected). Tympanomerus ceratophora (Koelbel). iSi}S. Dioxippe ceratoplwi'ii. Koelbel, in Wiss. Ergebn. Reise dnifeii beta Sz-L'clienyi in Osfnsien II, p. 573, pi. i, figs. 8-12. ii;i,S. '/'v/npai/ovients cerafopliora, Tesch, Decap. Rracliviir. 'Siboga' E.x- ped. I, p. 50, pi. 2, fit^-. 2. Hongkong (Koelbel) ; River near Pidjot, Lombok (Tesch). EXPLANATION OF PI.ATE XII. Fig. I. — Scopiviera pilula, sp. nov. Dorsal view of a male with carapace about lo^ mm. in breadth. ,, 2. — Scopimera globosa, de Haan. Dorsal view of a male with carapace about 14 mm. in breadth. ,, 3. — Scopimera proxima, sp nov. Dorsal view of a male with carapace about 7 mm. in breadth. Rec. Ind. Mus-.Vol.XVI. 1919. PLATE lUJ. s e.MoiuiiJ niwii,i.Ttauulu«..l£>lJi ■Author's Copy. RECORDS of the INDIAN MUSEUM Vol. XVI, Pari V, No. 25. Notes on Crustacea Decapoda in the Indian Mviseum. XIII. The Indian species of Macrophthalmus, By 5. KEMP. C7\LCUTT7\ JULY, 1919. XXV. NOTEvS ON CRUSTACEA DEC A POD A IN THE INDIAN MUSEUM. XIII. The Indian speciks of Macrophthalmus. By Stanley Kemp, B.A., Superintendent^ Zoological Survey of India. Plate XXIV. Since Alcock published his account of the Indian species of Macroplithalmus in 1900 ' a considerable amount of additional material has been obtained from various sources. A number of species not hitherto known from Indian waters have been added to the list, while several which were known to Alcock only by name have been rediscovered. In determining the species I have derived great assistance from Dr. Tesch's recent monograph of the genus.* This work contains a most valuable key to twenty-five species, critical notes on their characters and synonymy and a great number of figures. I have found myself in complete agreement with Tesch as regards the species recognised by him, but I differ from him, and from other recent authorities also, in my views on the position of the species usually termed Euphx bosci. The genus Euplax was established l^y Milne-Edwards for the reception of certain species which he found to differ from typical Macrophthalmus in the squarer outline of their carapace, in their shorter eyestalks and in the shortness of the chelipeds in both sexes. During the sixty years that have intervened since Milne-Edwards wrote, numbers of additional species have been described, referred for the most part to Macrophthalmus, and nowadays it is no longer possible to form two distinct groups on the characters on which he based his generic distinction. Tesch, in his account of the Grapsoid crabs collected by the ' Siboga' ex]3edition ^, distinguishes Euplax from Macrophthalmus by other characters : by the extent of the gape between the external maxillipeds and by the proportions of the merus of those appen- dages. In these respects, however, the difference is sometimes so very slight that it is clear that they do not afford a basis for generic differentiation. 1 .-Xlcock, Joiiru. Asiat. Soc. Bengal, I. XIX, p. 375 (igooi. •2 Tesch, Zool. Medcd. Rijlas Miis. Xaf. Ilisf. Leiden, 1, pp. 149-204, pis. v- ix (1915). 'i Tesch, Derap. Brachvnr. 'SUmga' E.xped.. XX.XIXc, p. 57 (l()lM. 384 Records of the Indian Museum. [Vol. XVI, Unfortunately it is not at present possible to include Euplax definitely in the synonymy of Macrof)hlhalmus, for E. hptophthalma from Chili, the type species of the former genus, has never been re-examined since Milne-Edwards described it ; there is thus a possibility that it may possess characters, hitherto overlooked, which entitle it to generic recognition. There is, however, very little doubt that E. &osc/ must be regarded as a species of Macrophthalmus, to which genus both Audouin and Krauss referred it. In his notes on the species Tesch remarks ' that the proportional length of the merus of the outer maxillipeds in relation to the ischium is vari- able. This variation also extends to the relative length and breadth of the merus ; the segment is sometimes nearly as long as broad, sometimes as much as one sixth broader than long. In this respect it is not possible to draw a distinction between E. hosci and such species as Macrophthalmus erato and M. pacificus. E. hosci, moreover, as Tesch has noted*, is so very closely related to Macrophthalmus crinitus, Rathbun, that the two forms can only with difficulty be distinguished from one another (see p. 391). There can be no possible doubt that the two species are congeneric, yet no one has suggested that M. crinitus should be referred to Euplax. In both species the gape of the outer maxil- lipeds is a little wider than in normal M acrophthalmus and the front proportionately broader. But the former distinction is a trivial one and the difference, on comparison with M . pacificus, is very small ; in the latter the species merely takes a place at one end of an evenly graded series. The position of the Australian species, described by Milne- Edwards as Cleistostoma tridentatum and recently referred to the genus Euplax by Miss Rathbun and Tesch, seems to require further investigation. On comparison with Hemiplax hirtipes from New Zealand I find mam^ points of resemblance. The two species agree with one another and differ from all normal species of Macroph- thalmus in three characters : — (i) the front is extremely broad, its breadth between the eyestalks being considerably more than one third that of the carapace, (ii) the sides of the front are strongh^ convergent anteriorly, and (iii) there are no enlarged teeth on the fingers of the male cheliped. It appears to me therefore that C. tridentatum should be referred to Heller's Hemiplax; but the dis- tinctions between this genus and Macrophthalmus are by no means convincing and it will perhaps be better to regard the former merely as a subgenus of the latter. At the present moment two broad-fronted Australian species of M acrophthalmus , M. punctulatus , Miers and M./a^z^'/raws, Has well, are known to us only from the original descriptions. When these have been rediscovered we shall probably be better able to decide on the position of C. tridentatum and on the validity of Hemi- plax. I Tesch, loc.cit., t()i8, p. 6n. "' Tesch, loc. cit., 1915, p- IQ2. 1919-] S. Kemp : Notes on Crustacea Decapoda. 385 Excluding three species altogether unrecognisable from the published descriptions, Tesch recognised twenty-six species of Mac- yophthaliniis in his monograph ; to these may be added M. bosci , Sav. & Aud., M. sandakani, Rathbun, M. gastrodes, Kemp and M. teschi described in this paper. The total number of species, includ- ing the somewhat doubtful M. latifrons, Haswell and M . punctu- latus, Miers, is consequently thirty. Alcock in his account of the Indian Catometopes described seven species of the genus and mentioned the names of four others which were said to occur in Indian seas. The total tmmber of Indian forms now stands at fifteen. The species are : — Species. Synonyms. .1/. peciinipes, Guerin. M. simpiicipes, Gucrin. M. transversus (I/atreille). M. compressipes, Randall. M. telescopicus (Owen). i M. podophthalmus, Souleyet. iivi . con M. poc M. ver M . latyeillei, Desmarest. )errauxi, Milne-Edwards. M. latipes, Borradaile. M. sulcatus, Milne-Edwards. M. brevis (Herbst). M. carinimanus, Milne-Edwards. M. convexus, vStimpson. M. inermis, A. Milne-Edwards. M. erato, de Man. M. desmaresti, IvUcas. M. serratus, Gray. M. polleni, Hofmann. M. lanigey, Ortmann. M. pacificus, Dana. M. bicarinatus, Heller. M. tomentosus, Souleyet. M. depressus, Riippell. M. affinis, Guerin. M. teschi, sp. nov. M. gastrodes, Kemp. M. crinitus, Rathbun. Of these I have seen all but M. latipes and M. latreillci. Macrophthalmus pectinipes, Guerin. 1900. MacrophtJialmiis pecti)iipes, Alcock, Joiirn. Asiat. Soc. Bengal, LXIX. P- 377- 1915. Macrophthalmus pectinipes, Fesch, Zool. Meded. Miis. Leiaeii, I, p. 156. I agree with Tesch that Guerin' s M. simpiicipes is probably founded on a young varietal form of this species. No additions have been made to the specimens examined by Alcock. The record from Orissa is based on a large male labelled " Cuttack. Dr. F. Stoliczka." This appears to l)e an error, for the original label, also found with the specimen, clearly reads ''Kutch." M. pectinipes is otherwi.se known only from Sind (Henderson), Karachi (Alcock), Bombay (Guerin) and Penang (Henderson). 386 Records of the Indian Museum. [Vol. XVI, Macrophthalmus transvcrsus (lyatreille). (Plate xxiv, fig. i.) 191=5. Macroplithnlnius traiisversiis, Ifsch, Zool . Meded. Miis. I.cidoi, i, p. 158, pi. V, hg. I {iihi /if.). This species is not mentioned by Alcock in his account of the Indian species; it was, however, recorded from Pondicherry b}' Milne-Edwards and has recently been found in great abundance by Dr. F. H. Gravely on the coast of Orissa The specimens agree well with the excellent figures published by Milne-Edwards in Cuvier's Regne Animal' and also, in most respects, with Tesch's figures and detailed description. The eyes are variable in length ; sometimes they reach beyond the tip of the orbital tooth by only half the length of the cornea, sometimes by fully twice its length. In none of the specimens I have seen are they quite so long as shown in Tesch's figure. The differences noted by Tesch in the granulation of the carapace are undoubtedly sexual ; in females the greater part of the surface is smooth and glossy, whereas in males it is closely covered with small granules. In his description of the male cheliped Tesch notes that the lower surface of the palm is bordered by two parallel serrated crests, but only one is visible in the specimens I have seen. The palm as a whole (fig. i) is more slender than in the figure and the fingers more strongly deflexed : when the claw is closed the dacty- lus is at right angles to the main axis of the palm. Tesch remarks that a part of the palm at the insertion of the movable finger '' seems to be detached, so as to form a separate joint, but the suture separating this part from the rest of the palm is not con- tinued on the inner surface." I think the appearance of a separate segment must be due to a partial fracture ; I can find nothing resembling it in any of the specimens I have examined. The dactylus differs from the description in bearing a large molar tooth near the base*, directed sHghtly backwards, and another which is much smaller in the distal third, fitting close behind the foremost tooth on the fixed finger. Between these larger teeth there is a series of denticles. The specimens are smaller than those seen by Tesch. In the largest male the carapace is 9*4 mm. in length and 22 mm. in breadth, the length of the chela being 15 mm. ^"fo^^" Chandipur, near Balasore, Orissa. F. H. Gravely. .Many. M. transversus has been recorded from Massouah (Cano). Pondicherry (Milne-Edwards) and Sumatra (de Man, Tesch). ' PI. xvi, fiss. 2, 2a-d. ' Obscurely shown on the left-hand chela in iVIilne-Edvvards' figure. igiQ-] S. Kemp : Notes on Crustacea Decapoda. 387 Macrophthalmus telescopicus (Owen). (Plate xxiv, figs. 10, 11.) igoo. Maci'upliflialmus verrniixi. Alcock, Jouvu. Asiat. Soc. Beii^a/. LXIX, P- 377- K)I5. Macroplitlutlmiis felescopiciis, I'esch. Zool. Meded. Mii^. Leiden. I. p. 161, pi. V, fig. 2. I accept Tesch's views on the synonymy of this species as a temporary measure, but further work is necessary before his con- chisions can be accepted as final. The species, as understood by Tesch, is one of extremel}^ wide distribution and it is quite pos- sible that two or more allied forms may be confounded. Com- parison of specimens from Australia, the Hawaiian Is. and the Red Sea is a necessary step to further progress. The material at my disposal is very limited, but the three males in which the chelipeds are extant differ considerably from one another. In a male from Port Blair in the Andamans (one of those examined bj' Alcock), with carapace 4*2 mm. in length and 6-y mm. in breadth, the fine keel on the outer face of the palm (fig. 11) near its lower border is decidedl}' sinuous and the fingers, as in Miss Rathbun's figure', gape very widely at the base. There is a small molariform tooth at the proximal end of the dactylus and another, in the form of a crest truncated anteriorly, near the tip of the fixed finger. The teeth on the lateral margin of the cara- pace behind the orbital tooth are blunt. In a larger male, also from Port Blair, with carapace 15 mm. in breadth and 9 mm. in length, the chela is of the same type, but the keel on the outer face of the palm is a little straighter. The lateral teeth of the carapace, behind the orbital angle, are sharp and the meral segments of the first walking legs (which have been lost in the smaller specimen) bear a dense patch of fur on the underside. i\ male from the northern end of the Gulf of Manaar, with carapace yd) mm. in length and I2'4 mm. in breadth, has sharp lateral teeth on the carapace and no furry patch on the lower side of the merus of the first walking legs. The keel on the outer face of the palm is much less sinuous in this specimen (fig. 10), the fingers do not gape, the tooth on the fixed finger is longer and a little more remote from the apex, while the molariform tooth on the dactylus is longer and broader and situated more nearly in the middle of the finger length. In this individual the terminal seg- ment of the abdomen is proportionately broader than in those from Port Blair. From the material at m}- disposal I am not able to decide whether the differences in these males are specific or merely a matter of variation. 1 K. Danske Vidensk. Selsk. Skrift. (7), itafurvid. ogmatli., V. p. 322, text- fig. 6(1910). 388 Records of the Indian Museum. [Vol. XVI, In none of the specimens I have seen is the propodus of the last leg dilated as in Borradaile's M. latipcs.^ Alcock recorded this species from the Andamans and Mergui ; additional specimens are from the following localities : — ^^0 Tor, Sinaitic Peninsula, Red Sea. R. B. S. Sewell. One?. -\%- Backwater at Pamban, Ramnad Dist., G. of Manaar. ... S. Kemp. One ^. ^-|^fl Fisher Bay, Port Owen, Tavoy I. ' Investigator.' Two ? (damaged). Macrophthalmus sulcatus, Milne-Edwards. (Plate xxiv, figs. 3-5). 1900. Maci'OplitJiahnus snlcatas, Wcoc\<., jfourn. Asiat. Soc. Bengal, I. XIX, P-379- 1915. Macrophthaltmis sulcafas. Tesch, Zool. Meded. Afus. Leiden, I, p. 165. The only specimens in the collection are the male and female examined by Alcock. They differ rather conspicuously in the form of the orbital and antero-lateral teeth. In the female the orbital tooth is shorter than in the male and is separated from the first lateral tooth by a comparatively wide gap (fig. 4). In the male the orbital tooth is curved backwards and upwards, slightly over- lapping the margin of the first lateral tooth (fig. 5). The form of the male chela is shown in fig. 3. I have compared these specimens with an example of the ver}' closely allied M. grandidteri , A. Milne-Edwards, from the Red Sea. The differences between the two species have been tabulated by Lenz.* Alcock by a lapsus calami states that the Indian examples of this species were obtained in the Andaman Is, They are in reality from Kutch. The species is otherw^ise only known from Mauritius (Milne-Edwards) and Australia (Ortmann) ; the latter localit}' is almost certainl)^ erroneous. Macrophthalmus brevis (Herbst). Macrophthalmus cariiiimaiuis, aiict. 1915. Macrophthalmus brevis, Tesch, Zool. Meded. Miis. I.eideii, 1, p. 169, pi. vi, fig. 5 (/(/;/. lit.). Tesch has shown that the name M. brevis must be emploj'ed for the species hitherto known as M. carininianus . It was recorded by Milne-Edwards under the latter name from Pondicherry, but it is only within the last few 3^ears that it has again been found in Indian waters. ^f§- Paway 1., .Mergui Archipelago. ' Investigator.' Five. The species is known from Mauritius (Milne-Edwards), Pondi- cherry (Milne-Edwards), Singapore (Gray), Halmaheira (de iNIan) and (Celebes (de Man). ' Faun. Geogr. Maldives Laccadives, I, p. 433, fig. 114 (1903). 2 Lenz, Abhandl. Senckenb. Ges. Frankfurt, X.XVU. p. 366 (1905). I9I9-] S. Kemp : Notes on Crustacea Decapoda. 389 Macrophthalmus convexus, Stimpson. (Plate xxiv, fig. 2.) 1900. Macyoplitluil imis ri>/n