4<)2 Records of the Indian Museum. [Voi,. XXIV, 



broad triangular plate, rather broader than long, apex bluntly 

 rounded and entire; telson quite unarmed. 



Inner and outer uropods short broad plates, equal in size, 

 furnished with long setae on both margins, inner uropod without 

 spines on its lower margin, statocyst large. 



First, second, third and fifth pleopods of the male simple 

 small unjointed plates, fourth pair with the endopod of normal 

 shape, consisting of a small unjointed plate with terminal setae and 

 a well marked side lobe, imperfectly marked off from the basal joint, 

 exopod consisting of a single long linear joint terminated by a single 

 stout seta, annulose at its tip, the whole exopod extending to the 

 tip of the uropods or slightly beyond. I,ength of the only speci- 

 men, an adult male, 4 mm. 



Remarks. — This species shows no very great affinities with 

 any described form. The form of the pleopods of the male clearly 

 shows its place in the tribe Mysini, but the shape of the antennal 

 scale and the very short unarmed telson are quite unlike any 

 member of that tribe. I hope that female specimens will be 

 forthcoming some day so that the sexual differences may be des- 

 cribed. It is the most interesting and distinctive species in this 

 collection. 



Genus Lycomysis Hansen. 



Lycomysis spinicauda Hansen » 



Text-figs. 2$a-c. 



Lycomysis spinicauda, Hansen, 1910, p. 77, pi. xi, figs. 3a-/", pi. xii, figs. 

 2a-li. 

 ,, ,, Colosi, 1916, p. 194, text-figs. la-d. 



,. ,, Colosi, 1918, p. 10. 



,, ,, Colosi, 1920, p. 251, pi. xx., figs, loa-g. 



,, pusilla, Zimmer, 1915, p. 175, figs. 30-37. 



Locality — Port Blair, Andaman Isles. , 

 St. 19. One male, 4*5 mm. 



Remarks. — I have no doubt as to the identity of this speci- 

 men with the species described by Zimmer. The agreement is, in 

 all points, complete. But I am somewhat puzzled as to the relation 

 of L. pusilla to L. spinicauda and, after due consideration, I have 

 reached the conclusion that the two species are identical, the sup- 

 posed differences being due to a difference of interpretation of 

 the structure of the male pleopods, the only character separating 

 the two forms. 



Hansen (1910) describing L. spinicauda from, an immature male 

 says (p. 76), "Pleopods in the male immature specimens small, 

 biramous, with the exopod [endopod] increasing in length back- 

 wards, being on the anterior pairs shorter, on the fourth pair some- 

 what longer, than the exopod, on the fifth pair twice as long as the 

 exopod, but very far from developed " and later (p. 77) ." unfor- 

 tunately the male pleopods are so imperfectly developed in my 

 specimens, that they cannot afford any real help for deciding the 

 systematic position of Lycomysis, yet it may be stated that they 



