332 The Philippine Journal of Science ish 



antennal scale of the second antenna. A glance at Table I shows 

 that the tip of the peduncle varies in position with reference to 

 the teeth on the lower border of the rostrum. In the smallest 

 males and females it extends to the third or fourth tooth, while 

 in the largest males with the small legs and in the largest 

 females it extends to the fifth, sixth, or seventh" tooth. In the 

 large males with the enormously developed chelipeds the tip 

 of the peduncle reaches almost to the end of the rostrum. 



First pair of legs. — The length of the first pair of legs with 

 reference to the length of the antennal scale does not seem to 

 vary much. In young males and females usually the propodus 

 of the first leg extends beyond the tip of the antennal scale, 

 while in the largest males the propodus and as much as one- 

 fourth or one-half of the carpus may be seen beyond the tip of 

 the scale. 



Chelipeds. — The chelipeds are much shorter in young males 

 and females than the length of the body from the tip of the 

 rostrum to the tip of the telson. Even in the adult and largest 

 females these fail to equal the body length. Also, males under 

 240 millimeters in length with weakly developed legs have the 

 chelipeds shorter than the body, but males over 250 millimeters 

 in length have the chelipeds longer than the body. The chel- 

 ipeds of the largest male in our collection (body length, 320 

 millimeters) measure 486 millimeters (ischium, merus, carpus, 

 and propodus), and they extend with one-half of the merus 

 beyond the tip of the antennal scale. As a rule, in young males 

 and females the palm and fingers are nearly of the same length, 

 but as the animals grow older the palm increases in length more 

 rapidly than the fingers, so that the proportion may be as much as 

 1 : 1.43. In Table I it will be seen that the smallest male in 

 the collection shows a proportion of 1 : 1.33. Only one cheliped 

 is present in this case, and I believe the proportion is unusual. 

 A similar proportional increase in the length of the palm is 

 seen in the female, but it is not so striking. In all of our speci- 

 mens, male and female, the carpus is shorter than the propodus. 

 The difference is not so great in the young specimens, and 

 I think it probable that younger specimens than we have might 

 show the carpus to be longer than the propodus, a condition 

 which de Man has observed in the young of the Indian form. 



The fingers of young specimens (100 millimeters) show no 

 toothing, but at 115 to 120 millimeters the teeth begin to make 

 their appearance. The mobile finger is armed along its cutting 

 edge with 2 acute teeth. The distal tooth is situated at a point 

 one-third of the distance or a little more from the articulation 



