136 Records of the Indian Museum. [Vol. XXIV 



deeply cleft, with the free portion of the shorter ramus longer than 

 the fused basal part : in a third (P. lampes) the free portion is 

 slightly shorter than the fused part : in the fourth (P. alcocki) the 

 flagellum is scarcely cleft at all, the free portion of the shorter 

 ramus being less than one- third the length of the fused basal part. 



Urocaris and Ancylocaris are thus, in my opinion, to be re- 

 garded as synonyms of Periclimenes. 



As regards the subdivision of the large assemblage of forms 

 included in the genus, it will be observed that Borradaile in 1915 

 proposed four subgenera, Ensiger, Corniger, Cridiger and Falciger 

 and in 1916 added a fifth, Hamiger. Two of these terms are 

 preoccupied as genera, and Mr. Austin H. Clark, who does not 

 seem hitherto to have interested himself in carcinology, has felt it 

 necessarj 7 to substitute others. 



The subgenus Ensiger includes only Dana's Anchistia anran- 

 tiaca, a species of doubtful affinity which has not been examined 

 since 1852. From the original account it is not even certain that 

 the species belongs to the subfamily Pontoniinae, for the telson is 

 described as "a little hairy at tip, with two short spines." Any 

 decision as to the proper position of Ensiger must therefore be 

 postponed until the type-species has been rediscovered. 



Borradaile refers the great majority of the species which he 

 includes in Periclimenes to the subgenera Cristiger and Falciger. 

 He separates the two (loc cit., 1917, p. 360) by a number of features, 

 but it will be seen that the only absolute criterion for their discri- 

 mination lies in the form of the rostrum, which is stated to be 

 convex in the former and straight or concave in the latter. This 

 character is one of very little value> In determining the speci- 

 mens in the Indian Museum I have made every endeavour to 

 separate the species on the lines which Borradaile advocates, but 

 have been forced to the conclusion that the division he recom- 

 mends, even if it were possible in practice, tends only to obscure 

 the real affinities of the species. The two Mediterranean species, 

 P. amethysteus and P. scriptus, are so far as I am aware distin- 

 guished from one another only by colour, yet Borradaile refers the 

 former to the subgenus Falciger and the latter to Cristiger. 



The subgenus Hamiger is without doubt synonymous with 

 Periclimenaeus, the position of which is discussed below. 



To the curious little group of species in which the cornea is 

 conoidal and pointed anteriorly Borradaile has applied the sub- 

 generic name Corniger; but the character, though an interesting 

 one, does not in my opinion, possess the importance that he attri- 

 butes to it. In the collection on which this paper is based I have 

 found one specimen with a conoidal cornea; but though in this 

 respect it resembles the forms that Borradaile refers to Corniger, 

 it is otherwise very different, for it possesses neither hepatic noi 

 supra-orbital spines. It is unfortunately impossible to draw up a 

 specific description from this individual, as it is without locality 

 and is much damaged, possessing only the first pair of legs. The 

 existence of such a form seems, however, to indicate that the 



