l62 



First pair of legs distinctly shorter than the external maxillipeds, though still reaching 

 beyond the antennal scale. Of the 2"'^ peraeopods the shorter and stouter one is situated on 

 the right side; the carpus is 7-jointed, the P' or proximal joint, the longest of all, is almost 

 half as long as the carpus, the 5 following are very short and subequal, the last half as long 

 as the first; of the chela, which is but little shorter than the carpus, the palm appears distinctly 

 broader than the distal joint of the latter and hardly longer than the fingers. The fingers of 

 the other slender leg are as long as the palm. The legs of the 3'^<' pair (Fig. 38^, 2>^d) project 

 by their dactylus and propodus beyond the antennal scale, those of the 4"* by their dactylus 

 and three-fourths of the propodus, the much shorter legs of the s'*" pair, finally, by little more 

 than the dactylus; the dactyli measure one-third of the propodi and the spines with which these 

 legs are armed on the lower border, are arranged in the t,"^ and 4'*^ pair in two rows, in the 

 5'*" pair only in one. 



The young specimen is about 58 mm. long, the rostrum is as long as the carapace, 

 not shorter, both together a little shorter than the abdomen, which is 30 mm. long; the upper 

 margin of the rostrum is armed with 15 teeth, 6 of which are on the carapace, the lower 

 with 10. The depressions on each side of the middle of the 3'''' tergum are already distinct, like 

 on the 4'^ and $^^. The stylocerite reaches a little beyond the middle of 2°'* antennular article, 

 scaphocerite half as long as carapace. The external maxillipeds extend, like in the adult, about 

 by half their terminal joint beyond the antennal scale, but the legs of the i^' pair reach 

 also by half their terminal joint beyond this appendage, being hardly shorter than the outer 

 foot-jaws. Peraeopods of the 2"<^ pair as in the adult. The three following legs also like in the 

 adult male, but the dactyli are a little longer than one-third of the propodi and the legs of 

 the 5''' pair project by their dactyli and three-fifths of their propodi beyond the antennal scale. 



The specimen from .Stat. 211 is but little larger than the preceding, the carapace being 

 17 mm. long from the orbital to the posterior margin; the rostrum is broken oft a little beyond 

 the antennal scale, 5 teeth stand on the carapace, the 6'^ just before the orbital margin. 

 Abdomen and legs like in the young female from Stat. 208. .Stylocerite not yet reaching the 

 far end of 2"*^ antennular article. 



The nearest allied species is probably Heteroc. Alexandri A. M.-Edw. from Havannah, 

 which according to Miss R.vtiirun occurs also off the Hawaiian Islands (M. J. R.vthbun', in : 

 U.S. Fish Commission Bull, for 1903, Part III, Wash. 1906, p. 918). This rare Heterocarpus 

 is only known by the figure in the "Recueil de Figures de Crustaces nouveaux ou peu connus", 

 published by A. Milne-Edwards in 1883, so that it is much to be regretted that no description 

 at all was given by ]Miss R.\thbun of the specimen, that she had the occasion to study. In 

 this species, however, only four teeth of the rostral carina are placed on the carapace and the 

 posterior tooth stands a little before the middle, in Heteroc. tricarinahts, however, constantly 

 behind the middle. The postantennal carina has completely disappeared. The 6'^ abdominal 

 somite is more than twice as long as the 5'*^ and but little shorter than the telson, the scapho- 

 cerite, finally, has a difterent shape, appearing distally just as broad as at base. 



A closely allied form is no doubt also Heteroc. vicarius Faxon from the Gulf of Panama. 

 In this species, however, the inferior lateral carina of the carapace reaches almost to the posterior 



