1915.] Fauna of the Chilka Lake : Crustacea Decapoda. 283 



by the greater length of the carpus of the second peraeopods which, even in the 

 female, is as long or longer than the palm. 



In addition it differs notably from P. ensifrons and P. elegans in the form of the 

 antennal scale, which in those species is concave externally and terminates in a spine 

 which far outreaches the narrow apex of the lamella. P. danae, as identified and 

 figured by Borradaile, has three posterior rostral teeth situated on the carapace 

 and the ultimate segment of the outer maxillipedes (according to the figure) only about 

 half the length of the penultimate. In P. edwardsi two posterior rostral teeth are 

 placed on the carapace and the antennular peduncle is longer, reaching the apex 

 of the antennal scale. 



In the scheme of classification recently proposed by Borradaile l P. demani 

 apparently finds a place in the subgenus Fähiger. 



Periclimenes demani, when alive, is transparent, speckled with greenish-yellow 

 chromatophores. A dark brown stripe is conspicuous in lateral view on either side of 

 the mouth and another similar stripe in front of the first pair of legs. The rostrum, 

 antennules and antennae are transparent with occasional greenish-yellow chromato- 

 phores. The legs are entirely transparent, except for the fingers of the large claw 

 which are bluish, and for a suffusion of bright orange yellow at the junction of the 

 fingers and palm of the same limb. On the thoracic sternum is a broad transverse 

 maroon band which involves the basal segments of the third legs. The margins of 

 the abdominal pleura and uropods are mottled with maroon and the eggs are sage 

 green. 



The species is not uncommon in the Chilka Lake, though much less abundant 

 than Urocaris indica. Unlike the latter form it is entirely absent from the main area 

 of the lake. It has been found in numerous localities in the outer channel, living 

 among weeds in quite shallow water; it has been taken off Barnikuda I., in Serua- 

 naddi, at Satpara, near Mahosa, and, in the flood season, among submerged vegeta- 

 tion near Manikpatna. 



The species appeared to be equally abundant both in March, where the water 

 was of the same salinity as that of the sea outside the lake and in September when it 

 was quite fresh. In March the breeding season was just beginning, a few females 

 bearing eggs that were not eyed ; by September it was apparently almost over, or a 

 second breeding period was almost completed, for the eggs borne by the single oviger- 

 ous female that was then obtained were fully eyed and on the point of hatching. 



The specimens from the neighbourhood of Madras, where the species appears to 

 be commoner than in the Chilka Lake, are, as already noted, of a larger size than 

 those found in the Chilka Lake. They were obtained by Dr. Annandale in October 

 19 13, in the Adyar River in water that was almost fresh, and also in the Knnur back- 

 water in January 1915, in water of specific gravity varying from i-ooo to 1-0045. 

 On both occasions ovigerous females were taken. 



The type specimens bear the number 8981-4/10 in the Indian Museum register. 



1 Borradaile, Ann. Mag. Nat. Hist. (8), XV, p. 207 (1915). 



