58 Memoirs of the Indian Museum. [Voi,. IV, 



would otherwise have been impossible and has proved of inestimable value in checking 

 and correcting the preliminary results arrived at from a study of the material in the 

 Indian Museum. Moreover, coming as they do from many widely distant localities, 

 I have been able to obtain a very good estimate of the distribution of the various forms. 

 In all nearly 800 -specimens have been examined. 



To many, the characters of the species which I have described below will appear 

 extremely trivial, and it must be admitted that much more work is necessary before 

 their exact relations can be decided in a really satisfactory manner. The point, how- 

 ever, which I specially desire to emphasize, which has been more and more impressed 

 upon me as additional collections came under examination, is that in Indian waters 

 there exist seven perfectly distinct forms that may always be separated from one 

 another with the greatest facility. Four of these, which I have called 5. oratorio, 

 var. perpensa, S. interrupta, S. wood-masoni and 5. massavensis , are very close allies 

 of 5. oratoria, s.S., a species which does not seem to occur in its typical form westwards 

 of the Philippines. Some will perhaps be inclined to regard them as varieties or sub- 

 species, but this is a point of little moment so long as their structure and distribution 

 are understood. 



It is only with great difficulty that young specimens (sometimes as much as 

 40 mm. in length) can be determined. In several cases I have been obliged to defer 

 any attempt at precise identification, but I do not doubt that if sufficiently extensive 

 series were available it would be possible to separate the different forms in a satis- 

 factory manner at all stages. 



I have found myself unable to determine the precise position of the form which 

 Nobili recognized under the name Squilla ajfinis var. intermedia} The original speci- 

 mens were obtained at Nias and Singapore and, on comparing them with ' 5. ajfinis '~ 

 from the latter locality, Nobili notes that the external margin of the raptorial dactylus 

 is more strongly sinuous and the eyes a little smaller. The dorsal carina of the carpus 

 of the raptorial claw is without tubercles. It is possible, and even probable, that the 

 form will prove identical with one of those described in this paper, :> but without 

 knowledge of the characters afforded by the median carina of the carapace, by the 

 lateral lobes of the free thoracic somites, and by the basal process of the uropods, no 

 satisfactory conclusions can be reached. I have tried to obtain a loan of the original 

 specimens, but have been unable to discover where they are preserved. 



21. Squilla foveolata, Wood-Mason. 

 Plate IV, fig. 48. 



1895. Squilla foveolata, Wood-Mason, Figs, and Desc. of nine Squillidae, p. 2. pi. ii, fig. 1. 

 The dorsal surface of the carapace and abdomen is very coarsely and deeply 

 impressed. This is specially marked on the antero-lateral parts of the carapace and 



1 Nobili, Boll. Mus. Torino, XVIII, 1903, No. 455, p. 39. 



2 These specimens are perhaps Squilla oratoria var. perpensa and S. interrupta. 



8 As a specific name intermedia is preoccupied by Bigelow's S. intermedia from the American Coast. 



