166 Memoirs of the Indian Museum. [Vo.. 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 Lanchester’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 Iam not 
convinced that this is so. ‘The examples of the form sfimosus 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 :— 
7497-8 
1) 
S038 
10 
N. Cheval Paar, Ceylon. ‘T. Southwell. 20,16, 16°5 mm. 
Pearl Banks, Ceylon (from Spongodes). ‘T. Southwell. 30,32, 18-22 mm. 
G. demani var. spinosus has been recorded from the Maldives (Lanchester), the 
Red Sea (Nobili) and from Mauritius (Bigelow). 
var. espinosus, Borradaile. 
1898. Gonodactylus espinosus, Borradaile, Proc. Zool. Soc., p. 35, pl. v, fig. 5, 54, 0. 
1903. Gonodactylus chiragra var. espinosus, Tanchester, Faun. and Geog. Maldives and Lacca- 
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. 
