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. 



