62 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



Description of laroa. — Bod}^ obloiig--ovatc, three times as long as 

 wide, \\ mm. : 4^ mm. 



Head small, about \ mm. long and \ mm. wide at the base, with the 

 front produced in a small truncated lobe. The eyes are large, round, 



composite, situated at the sides of the head 

 and occupying almost the whole of the lateral 

 margin. The tirst and second antennae are 

 about as in the male. 



The first segment of the thorax is rudimen- 

 tary and consolidated with the head. The 

 second and third segments of the thorax are 

 short and subequal; the fourth and fifth seg- 

 ments are united into one extremely long- 

 segment, which is also wider than the two 

 preceding segments. The sixth segment is 

 short and gradually decreases in width, at its 

 anterior extremity being almost as wide as 

 the preceding elongated segment, but at its 

 posterior extremity being almost as narrow 

 as the abdomen. The seventh segment is 

 similar to the abdominal segments. 

 The abdomen is about \ mm. wide. The first five segments are sub- 

 equal. The sixth or terminal segment and the uropoda are as in the 

 male. 



There are apparently but five pairs of legs. The first pair of legs 

 are small and surround the mouth; the}'^ are composed of six articles. 

 The seventh pair is wanting. 



The mouth parts project conspicuously in front of the head. 



Fig. 46.— Gnathia 

 (After Haeger). 



Family IV. ANTHURIDJi:.« 



Body long and narrow, nearly cylindrical in form. Head compara- 

 tively small. Segments of thorax well defined and without distinct 

 epimera. Abdomen comparatively short, with the anterior segments 

 sometimes completely or partially fused. ^louth parts modified for 

 suction. First pair of legs larger and stronger than the others and 

 subchelate; the two following pairs also subchelate, but smaller and 

 more feeble; the four posterior pairs ambulatory. First pair of pleo- 

 poda large and expanded, more or less covering the others, especially 

 in female. Uropoda with the outer or superior branch arching over 

 the base of the telson. 



«See Sars, Crust, of Norwa.y, pp. 43-44, and Norman and Stebbing, Trans. Zool. 

 Soc. Lend., XII, 1886, Ft. 4, pp. 119-120, for characters of family. 



