i66 Memoirs of the Indian Museum. [Vol. IV, 



marginal teeth. In other respects its characters are closely paralleled by certain ex- 

 treme forms of typical G. demani. In some of the examples in the Indian Museum 

 the lateral and intermediate teeth of the telson are slightly better developed than is 

 indicated in Manchester's figure (see fig. 112). 



Nobili (1906 (a), p. 330), when recording comparatively large specimens that appear 

 to a great extent intermediate between G. demani and var. spinosus, considers it probable 

 that the lateral and intermediate telson teeth develop with age. 



The colouring of two of the Indian specimens, examined in weak formalin shortly 

 after capture, was peculiar. The general tone was straw or lemon yellow marbled with 

 a paler shade, and a few isolated jet-black chromatophores were placed in transverse 

 rows on the posterior third of the carapace and on most of the abdominal somites, 

 each chromatophore being set in the middle of a pale spot. The yellow colouring 

 ceased abruptly at a distinct olivaceous brown line on the last abdominal somite, and 

 behind this there was a broad band of pure white involving the ends of all the carinae. 

 The telson was mottled with white, olivaceous brown and yellow, and the antennal and 

 antennular peduncles were faintly banded with dull red. 



Mr. Patience regards G. spinosus merely as a synonym of G. demani, but I am not 

 convinced that this is so. The examples of the form spinosus which I have been able 

 to examine were all found on the Ceylon Pearl Banks, on which, so far as I am aware, 

 no specimen of the typical G. demani has yet been obtained. 



The largest specimen known is 33 mm. in length (Nobili). Eight specimens have 

 been examined : — 



^p N. Cheval Paar, Ceylon. T. Southwell. 2 c? , 16, 16-5 mm. 



~ Pearl Banks, Ceylon (from Spongodes). T.Southwell. 3 & , 3 9 , 18-22 mm. 



G. demani var. spinosus has been recorded from the Maldives (Manchester), the 

 Red Sea (Nobili) and from Mauritius (Bigelow). 



var. espinosus, Borradaile. 



1898. Gonodactylus espinosus, Borradaile, Proc. Zool. Soc, p. 35, pi. v, fig. 5, $a, b. 

 1903. Gonodactylus chiragra var. espinosus, T y anchester, Faun, and Geog. Maldives and I,acca- 

 dives, I, p. 455. 



The telson is as broad as, or perhaps a trifle broader than long, the intermediate 

 and marginal teeth are obsolete, and on the dorsal surface the customary spinules are 

 entirely absent. 



This form seems to be nothing more than a variety of G. demani, and it may ulti- 

 mately appear that it is merely an extreme form in a series exhibiting continuous 

 variation and, as such, does not deserve recognition under a separate name. As far as 

 I am aware it differs from G. demani only in the total absence of the spinules on the 

 telson, and in the reduction of the intermediate and lateral teeth of the margin and, 

 both in the size of these teeth and in the number of dorsal spinules, G. demani is 

 extremely variable. From the var. spinosus it is distinguished by the absence of 

 spinules and by the slightly broader form of the telson. 



