302 Memoirs of the Indian Museum. [Vol. V, 



the fingers of the small chela gape l and in the detailed description it is stated that 

 their inner margins are unarmed. In typical malabaricus the fingers are parallel and 

 meet throughout their length when the claw is closed (there is a slight gape in 

 one specimen) and at the base of the dactylus, as described by Henderson, there 

 is a large tooth. 



In 3^oung specimens the spine which terminates the outer margin of the antennal 

 scale frequently reaches forwards beyond the apex of the lamella as in var. dolichogna- 

 thus ; in large individuals, as in var. hptopus, it does not exceed this point. 



It may hereafter be found that the two varieties cannot be maintained, though, 

 in the present state of our knowledge, the three forms may be distinguished by the 

 parallel or gaping fingers of the small chela, by the presence or absence of a proximal 

 tooth on inner margin of the dactylus and by the relative proportions of the segments 

 of the last three pairs of legs. 



The largest specimen in the collection has a length of 29 mm. In this example 

 the length of the large chela is 17 mm. 



The colour of living specimens is very striking. The entire animal is semi- 

 transparent with chromatophores of bright red or reddish-brown pigment arranged in 

 transverse bars on the carapace and abdomen. The gastric and hepatic organs 

 show through the carapace as blackish and greenish masses. Each of the transverse 

 bars of chromatophores is broadest in the middle, narrowed and directed forwards 

 on either side. On the carapace are four such bars, the posterior much the broadest, 

 while on the abdomen there are seven, the last extremely narrow. There are also 

 red chromatophores at the base of the telson and in the centre of the uropods, while 

 the tips of these segments and of the telson are heavily blotched with deep blue. 

 The antennules and antennae are almost colourless. The chelae of the first legs are 

 dull sage green, dotted with reddish-brown, the tips of the fingers in the larger claw 

 being fawn-coloured or pink. The second legs are transparent, dotted with red 

 distally, and the last three pairs are transparent with the mero-carpal and carpo- 

 propodal joints bright yellow. The eggs borne by ovigerous females are dull yellow. 



Alpheus malabaricus is not uncommon in the outer channel of the Chilka Lake, 

 but has not been found in the main area. It was taken off Satpara and in the 

 vicinity of Barhampur I. at depths varying from 6 to 12 ft. living on a bottom of 

 soft mud. Its habits are thus strikingly different from those of A. crassimanus, 

 which occurs only on rough ground, — on oyster-beds or under stones. The species 

 was found both in March, when the water was as salt as that of the Bay of Bengal near 

 the lake-mouth, and in September when it was quite fresh. The only ovigerous 

 female in the collection was obtained in March . 



Dr. Annandale found examples of this species, also 011 muddy ground, in the 

 Ennur backwater near Madras m January 1915. The species occurred in water of 

 specific gravity i - oo2 and one individual was bearing eggs. 



1 The reference to this point in the full description of var. lepiopus is obscure, for the fingers are 

 described as having " their inner margins shutting together." 



