IÓ6 



in the female a little shorter, slightly grooved longitudinally and there are 4 pairs of dorso- 

 lateral spinules besides those at the tip. 



The two pairs of antennae also apparently agree with those of Heteroc. tricarinatus. 

 In the female the stylocerite reaches just beyond the distal extremity of 2 nd antennular article, 

 in the male it is a little shorter than this article. Scaphocerite (Fig. 40^) in the female 15,6111111. 

 long, 5 mm. broad, in the male these numbers are 16,5 mm. and 5,6 mm., the scaphocerite 

 being half as long as the carapace and 3-times as long as wide; it has the same form as in 

 Heteroc. tricarinatus, but the outer margin is more regularly curved, while in tricarinatus it is 

 anteriorly slightly concave. 



The external maxillipeds, that bear a well-developed exopodite, extend in the female by 

 two-thirds, in the male only by one-third of their terminal joint beyond the tip of the scaphocerite. 



The thoracic legs also resemble those of Heteroc. tricarinatus, as regards their relative 

 proportions, except the dactyli, which in Heteroc. lepidus, like in Heteroc. lacvigatus, are 

 considerably shorter and show a different form. The propodus and dactylus of 3 rd 

 legs (Fig. 40^, 40^) are respectively 20 mm. and 2,5 mm. long in the female from Stat. 215% 

 16 mm. and 2,5 mm. in the male from Stat. 262, the dactylus measuring in the male one- 

 sixth, in the female one-eighth of the propodus; in the adult male of Heteroc. tricarinatus 

 from Stat. 208, however, the propodus of 3 rd leg is 15 mm. long, the dactylus 5 mm., the latter 

 one-third of the propodus. The dactylus (Plate XIII, Fig. 38e/) of Heteroc. tricarinatus 

 shows the same s 1 e n d e r form as in Heteroc. gibbosus Bate, while its form in this new species 

 is the same as in Heteroc. laevigatus Bate, namely short and stout. 



In the female the peraeopods of the 3 rd pair project by the dactylus, the propodus and 

 three-fifths of the carpus beyond the antennal scale, in the male by the dactylus, the 

 propodus and one-fifth of the carpus ; those of the 4 th pair in the female by the dactylus, 

 propodus and one-fourth of the carpus, in the male these legs are partly broken ; those of the 

 5 th pair, finally, in the female by the dactylus and two-thirds of the propodus, in the male by 

 the dactylus and half the propodus. 



Three other species, all from the Atlantic, are also more or less related to Heteroc. 

 lepidus. Both in Heteroc. laevis A. M.-Edw. from Martinique and in Heteroc. Alexandri A. M.- 

 Edw. from Havannah the i st tooth of the gastric carina stands anterior to the middle of the 

 carapace, n e a r e r to the orbital than to the posterior margin ; in Heteroc. laevis the lateral 

 carinae of the carapace are apparently wanting and the carpi of the three posterior legs are 

 of a less slender shape, in Heteroc. Alexandri the postantennal carina seems to be wanting 

 at all, the 6 th somite of the abdomen is more than twice as long as the 5" 1 , the scapho- 

 cerite does not narrow anteriorly, the dactyli, finally, of the three posterior legs are slender 

 and elongate, all according to the figures of these species in the "Recueil de Figures de 

 Crustacés nouveaux ou peu connus", published by A. Milne-Edwards in 1883. 



Heteroc. Gri/ualdii A. M.-Edw. and Bouv. from the Azores differs by the postantennal 

 carina reaching almost to the posterior margin of the carapace and by the dorsal carina of the 

 3 rd abdominal tergum terminating posteriorly into "une pointe saillante" (Buil. Soc. Zool. de 

 France, T. XXV, 1900, p. 58). 



