I9 T 5-] Fauna of the Chilka Lake ; Crustacea Decapoda. 297 



greatly enlarged chela ; on its inner edge is a series of small teeth, varying in size, but 

 for the most part ill-developed. The carpus is very short, about two-sevenths the 

 length of the merus, and its breadth is about half its length. The chela is about 

 four times as long as broad ; the palm is 27 times as long as broad and about twice 

 the length of the dactylus. In front of its middle point, on the antero-internal 

 aspect, there are usually one or two small tubercles. The fingers are without teeth on 

 their cutting edges; the dactylus is strongly curved and longer than the fixed finger, 

 which is nearly straight and bluntly pointed apically. 



In males of Form II (text-fig. 31c) the first peraeopods are symmetrical, or 

 nearly so, each being similar to the large limb of Form I. The merus in the speci- 

 mens of this form is a little longer than the chela and is less expanded than in Form I, 

 being 5-4 times as long as broad. The carpus is longer, fully half the length of the 

 merus, while the chela has much the same proportions, but is a little broader, about 

 three and one third times as long as wide. A tubercle is sometimes seen on the 

 antero-internal aspect of the palm and there are a few spines on the inferior margin 

 of the merus. 



In Form III (text-fig. 31^) the legs of the first pair are asymmetrical, though 

 both are much enlarged. In both limbs the spines on the border of the merus are 

 more numerous and better developed than in Forms I and II and there may also be 

 small tubercles on the carpus and a series on the inner face of the palm. The smaller 

 limb bears a close resemblance to those found in Form II. The merus is 47 times as 

 long as wide, the carpus is a little less than half its length and is about twice as long 

 as broad. The chela is about three times as long as broad and the dactylus is more 

 than half the length of the palm. In the larger limb the merus is similar, 4*6 times 

 as long as wide, while the carpus is distinctly shorter, about one-third the length of 

 the merus. The chela is a little shorter than the merus and about three times as long 

 as broad. The fixed finger differs conspicuously from that borne by the leg on the 

 other side of the animal in the possession of a large rounded tooth or lobe near the 

 middle of its inner margin. 



The second peraeopods (text-fig. 32^) are folded like those of the first pair, 

 being flexed at the mero-carpal articulation . The merus is a little longer than the 

 ischium ; the carpus is almost one and a half times the length of the merus and is 

 fully three times as long as the chela. The carpus in a'l except two individuals is 

 composed of five sub-segments: the first is much the longest, almost three times the 

 length of the fifth, and the second, third and fourth are subequal and but little longer 

 than broad, each being about half the length of the fifth. The dactylus is a little 

 longer than the palm. As noted above (p. 295) the carpus in one male belonging to 

 Form I is, on one side only, composed of four sub- segments, while in one of the 

 females each limb of this pair has a similar development. The reduction in number 

 is apparently brought about, in these abnormal individuals, by the fusion of the 

 two proximal segments (text-fig. 32e). 



The last three pairs of peraeopods are similar ; their segments are devoid of 

 spines and their dactyli are simple, not biunguiculate as in certain other species of 



