17:5 



The antenimlar scale is narrow and acute : there are two spinclets at the- 

 outer angle of the basal joint of the autennular peduncle. 



The antennal scale is narrow and does not reach the end of the antenna! 

 peduncle. 



The 1st pair of thoracic legs are a little shorter than the body: the upper 

 border of the merus is spinose and the lower border spinulose, the upper border 

 ot the carpus is spinulose and both borders of the palm are serrated: the usual 

 spine or tooth is found at the far end of the upper border of the merus and palm 

 and of both borders of the carpus: the whole hand is a little longer than the 

 merus, and the palm is about as long as the wrist, the fingers being about one- 

 third longer. 



In the female all five pairs of thoracic legs are perfectly chelate, but in the 

 male the oth pair are nearly simple. 



The epipodites of the external maxillipeds are short and little setose : those 

 of the thoracic legs are of moderate length. 



Colour in life, pink. 



In the largest female the length of the carapace in the middle line is \'-\ 

 millim., of the abdomen 54 millim., that of the large chelipeds 89 millim. 



Andaman Sea 188 to 220 fathoms; Arabian Sea, 224 to 284 and 71 ( > 

 fathoms. 



. 67fi7-6770 /m ,. ,, N 8794 343.S 



Kegd. Nos. (Types of the species) : : . 



101. Pentacheles yibbus, Alcock. 



Pentncheles gibbus, Alcock, Ann. May. Nut. Hist., March 1894, p. 234. 



ILLUSTRATIONS OF TBE ZOOLOGY OF TIIK INVKSTIUATOR, CRUSTACEA, PLATE VIII. FIG. 4. 



The carapace, although its outlines are quite normal, is decidedly convex 

 dorsally in the adult and very strongly so in the young, its surface when 

 denuded is granular with some scattered spinules. Its frontal border is con- 

 cave with no spines except the rostral pair and a scrobiculate spine at the 

 frontal end of the impacted eye-stalk. The orbital sinuses are triangular 

 and shallow. The lateral borders of the carapace are slightly convergent 

 anteriorly and are armed with about l2"> spines, namely. "> or l> + 3 in front of the 

 cervical groove, and about 17 of diminishing size behind it. The median dorsal 

 carina is granular and irregularly spiny and more or less distinctly double, in all 

 its course. The posterior border of the carapace is perfectly smooth. Theiv 

 are some spinules on the ridge that bounds the cervical groove, but no othe?- 

 definitely placed spines; and there is no ridge running parallel with the poster. - 

 lateral borders on either side, or only traces of one. 



