76 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXXV. 



Fig. 5. — Haploniscus 

 nis. Abdomen of 

 (Dorsal view.) 



retrospi- 



FEMALE. 



Head wider than long, with the anterior margin slightly excavate 

 between the antero-lateral angles; the head is wider posteriorly than 



anteriorly. There are no eyes. The 

 first pair of antennas have the first arti% 

 cle of the peduncle short. The second 

 article is much longer; the flagellum is 

 composed of five articles and extends to 

 the end of the peduncle of the second 

 antennae. The first four articles of the 

 second antennae are short; the last two 

 are longer and subequal; the third arti- 

 cle of the peduncle is furnished with an 

 antennal scale ; the flagellum is composed 

 of eight articles. 



The first three segments of the thorax 

 are about equal in length; the fourth 

 segment is the longest and especially long in the middle region; the 

 fifth and sixth segments are about equal 

 in length, and are shorter than the 

 fourth; the last segment is shorter than 

 either of the two preceding segments; 

 the lateral margins of all the segments 

 are straight, the epimera occupying the 

 entire lateral part of the segment. 



The abdomen consists of a single seg- 

 ment, the lateral margins of which con- 

 verge gradually to the posterior extrem- 

 ity, which has a large rounded median lobe, on either side of which 



is an acute triangular process. The uro- 

 poda consist of a single small article, not 

 extending beyond the post-lateral tooth, and 

 placed between that and the median lobe. 



All the legs are ambulatory in charac- 

 ter, similar and with dactylus uni-ungui- 

 culate. They are alike in both sexes. 



Three specimens, two males and one fe- 

 male, come from Station 2572, U. S. Bu- 

 reau of Fisheries' steamer A Ibatross, south- 

 east of Georges Bank, taken at a depth of 

 1,760 fathoms. 



The type is in the U. S. National 



Fig. 6. — Haploniscus retrospi- 

 nis. (Second antenna.) 



Fig. 7. — Haploniscus retro- 

 spinis. Abdomen of male. 

 (Ventral view.) 



Museum, Cat. No. 38965. 



° Norwegian North-Atlantic Expedition, XIV, Zoology, Crustacea, I, 1885, pp. 

 122-125. 



