168 Memotrs of the Indian Museum. [Vou. IV, 
immediately behind the median there is a pair of small tubercles. The lateral 
marginal teeth are frequently rather more distinct than in G. chiragra. 
5. On the inner side of the external spine of the basal process of the uropods there 
is a small tooth or lobe placed quite near the base. 
The keels on the sixth somite like those of G. chivagra may be swollen or narrow, 
and may or may not terminate in spines. Between the submedians an additional 
narrow longitudinal keel is occasionally found. Except for the usual L-shaped ridge 
along the lateral and antero-lateral margins and for the small pit mentioned above, the 
first five abdominal somites are quite smooth. ‘The five keels in the middle of the 
dorsal surface of the telson may be swollen without distinct interspaces, or narrow and 
well separated ; the three median frequently end in spines. ‘The central keel never, 
or very rarely, assumes the shape of an anchor, but is sometimes subdivided into 
three very short branches at its distal end (see Lanchester, pl. xxiii, fig. 8). In respect 
of the above modifications the species unquestionably exhibits continuous variation, 
but among the Ceylon specimens, which form the vast majority of those examined, a 
spineless form with moderately or greatly swollen keels seems to predominate. 
The Ceylon examples were preserved in formalin, and when examined, not long 
after capture, showed a most remarkable range of colour variation. The commonest 
shade was a uniform olivaceous yellow, while other examples were dull purple, deep 
purplish green profusely mottled, dark olive, olive brown with paler marbling, brick 
red or dull orange. On the last abdominal segment a pair of very small black spots 
were constantly found close to the anterior margin, situated one on either side between 
the submedian and intermediate keels. The keels on this somite and on the telson were 
in most cases defined by a darker tone. 
The specimens of G. glabrous in the Indian Museum are registered as follows :— 
ms Mergui Archipelago. ‘ Investigator.’ SF ae 
*  Nicobars. F. Stoliczka. 1? , 35 mm. 
ue Port Blair, Andamans. I. A. de Roepstorff. 1?,98 mm. 
a“ Andamans. “ Investigator.’ id , 23 mm. 
os Galle, Ceylon. J. Anderson. 22,34, 38 mm. 
ue Cheval Paar, Ceylon. ‘l. Southwell. 223,569, 14°5-61 mm. 
uss Pearl Banks, Ceylon (from Spongodes). ‘T. Southwell. 13,32, 41-64 mm. 
a) Bombay. ; Bombay Nat. Hist. Soc. I¢,33 mm. 
825 Tho Archipelago, Portuguese E. Africa.! J. J. Simpson. Id ,29,50-68 mm. 
In addition the following specimens have been lent me for examination :— 
Ceylon. Colombo Museum. Id ,12, 33,35 mm. 
Bombay. Bombay Nat. Hist. Soc. 2, 33, 40 mm. 
Gonodactylus glabrous appears to be a common species, but perhaps frequents 
! For these examples 1 am indebted to Mr. Patience. 
