30 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



LEPTOCHELIA RAPAX Harger.« 



Leptochelia rapa.i Harger, Proc. U. S. Nat. Mus., II, 1879, p. 163; Report 

 U. S. Commissioner of Fish and Fisheries, 1880, Pt. 6, pp. 424-426, pi. xiii, 

 figs. 89, 90.— Sars, Archiv. for Math, og Naturvid., 1882, p. 28.— Richard- 

 son, American Naturalist, XXXIY, 1900, p. 212; Proc. U. S. Nat. Mus., 

 XXIII, 1901, p. 503; Trans. Conn. Acad. Sciences, XI, 1902, p. 279. 



Localities. — Annisquam, Massachusetts; and the Bermudas. 

 Depth, — 3 ft. on mudd^' bottom; \ fathom. Lives in tubes. 

 Body narrow, elongate, about four times as long as wide, 1 mm. : 

 4 mm. 



Head as wide as long, 1 mm. :1 mm., with the anterior margin 

 between the eyes triangularly produced. The eyes are small, round, 

 composite, and situated on the produced antero- 

 lateral angles of the head. The tirst pair of antennae 

 are extremely long in the male; the first article is 

 1^ mm. long, or longer than the head; the second 

 article is one-half as long as the first; the third is 

 one-half as long as the second. The tlagellum is 

 composed of seven articles. The second pair of 

 antennae are very short and feeble as compared with 

 the tirst antennas, and extend only half the length 

 of the first article of the second antennae The 

 first article of the second antenna? is about equal in 

 length to the second; the third is a little shorter 

 than the second, and is furnished with hairs at the tip. 

 The first segment of the thorax is coalesced with 

 the head. The six following free segments are 

 about equal in length, with the exception of the 

 first, which is a little shorter than any of the others. 

 The abdomen is composed of six segments, sub- 

 equal in length, the last segment not having the 

 lateral parts developed as in the five preceding segments. The urop- 

 oda are double branched. The inner branch is composed of five arti- 

 cles. The outer branch is composed of only one article. The peduncle 

 of the uropoda is about as long as wide. There are five pairs of well 

 developed pleopoda attached to the first five segments of the abdomen. 

 Between the uropoda and arising from the ventral side is a long narrow 

 plate, probably attached to the fifth abdominal segment; it terminates 

 in a rounded extremity. 



The first pair of legs in the male are very much elongated and extend 

 a great distance in front of the head. The carpus is about half the 

 length of the entire body; the propodus is as long as the carpus, the 

 digital process being more than half the length of the carpus, and 

 armed on the inner side near the base with a small triangular process 



Fig. 30.— Leptochelia 

 EAPAx (After Hak- 

 GER). Male, x 12. 



« See Harger for more detailed description of this species. 



