202 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



large, oval, composite, separated in front by a distance nearly equal 

 to the width of one eye. Basal article of the first pair of antenna* 

 short and nearly concealed by the. front of the head; second article 

 twice as long as the basal article; third article twice as long as the 

 second one. Flagellum is composed of six articles. The first antennae 

 extend to the end of the peduncle of the second pair of antenna* or to 

 the antero-lateral angle of the first thoracic segment. The first two 



articles of the second pair of antenna? 

 are short, the second shorter than the 

 first; the third is twice as long as the 

 first; the fourth is equal in length to 

 the third; the fifth is one and a half 

 times longer than the fourth. The 

 flagelluni is composed of fourteen to 

 fifteen articles. The second antenna? 

 extend to the posterior margin of the 

 second thoracic segment. The frontal 

 lamina is small, almost inconspicuous, 

 rhomboid-shaped at the base, which is 

 ventrally placed. The maxilliped has 

 a palp of two articles. 



The first segment of the thorax is a 

 little longer than the others. The 

 epimera are distinct from the seg- 

 ments in all but the first segment; 

 they are narrow plates with the pos- 

 terior extremity very acute in the last 

 four. The epimeron of the seventh 

 segment is produced beyond the pos- 

 terior margin of the segment. A 

 distinct carina obliquely crosses all 

 the epimera. 



The first segment of the abdomen 

 is almost entirely concealed by the 

 seventh thoracic segment. The lat- 

 eral parts of the abdominal segments 

 are not separated off from the dorsal 

 portion. The sixth or terminal seg- 

 ment is rounded posteriorly. The 

 inner branch of the uropoda is longer than the outer branch and a 

 little wider. It does not extend beyond the extremit}^ of the terminal 

 abdominal segment. The peduncle extends as far as the tip of the 

 outer branch. Both branches are rounded posteriori} 7 . Uropoda and 

 terminal abdominal segment furnished with spines along the margins. 



FlG. 195. R.OCINELA AMERICANA (AFTER 



HARGER). a, DORSAL VIEW OF FEMALE. 

 x 2. b, VENTRAL VIEW OF FEMALE, x 2. 

 c, HEAD AND FIRST THORACIC SEGMENT OF 

 MALE, x 2. d, LEG OF SIXTH PAIR, x 6|. 

 e, LEG OF FIRST PAIR, x 6|. 



