196 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



the antennw. The eyes are large, oval, composite, and not contigu- 

 ous, but separated in front by two high, conspicuous carinas, each carina 

 extending- along the anterior edge of the eye, being somewhat diver- 

 gent and divided ))y a median longitudinal depression. The anterior 

 margin of the head ))etween the eyes is three-lol)ed, the median lobe 

 being slightly anterior to the other two. The first pair of antenna? have 

 the basal article short and almost inconspicuous; the second article is 

 almost twice as long as the first; the third is twice as long as the sec- 

 ond. The flagellum is composed of seven articles. The first antenna? 

 extend to the middle of the hfth article of the peduncle of the second 

 pair of antenna?. The first two articles of the second pair of antenniB 

 are short, the second one shorter than the first; the third and fourth 

 are about equal in length and twice as long as the first; the fifth arti- 

 cle is a little longer than the fourth. The Hagellum 

 is composed of hfteen articles. The second antennte 

 extend to the middle of the third thoracic segment. 

 The frontal lamina is small and almost inconspicuous; 

 it is rhomboid-shaped and ventrally placed. The max- 

 illiped has a palp of two articles. 



The fourth, fifth, and sixth thoracic segments are a 

 little longer than an}^ of the others. The epimera in 

 all the segments from the second to the seventh inclu- 

 sive are distinct and have the posterior extremities 

 very acute, the angle being sharper in the last four. 

 In the last three segments the epimeron is produced 

 beyond the posterior margin of the segments. A 

 carina extends o])li(|uely across all the epimera. 

 The first segment of the abdomen is almost entirel}' 

 covered by the seventh thoracic segment except at the sides. The 

 lateral parts are not separated from the dorsal portion of the segments. 

 The sixth or terminal segment is narrowly rounded at the extremity; 

 its posterior margin is furnished with spines. The uropoda extend to 

 the tip of the a})domen. The branches are equal in width, but the 

 inner one is a little longer than the outer one. Both are furnished 

 with spines. The peduncle extends as far as the extremity of the 

 outer branch. 



The first three pairs of legs are prehensile, the last four pairs ambu- 

 latory. In the three anterior pairs, the propodus is armed with four 

 spines, the carpus with one, and the raerus with three. The ambulatory 

 legs are furnished with numei'ous spines. 



Fig. 182.— Rocinela 



DUMERILII. Leg OK 

 SECOND PAIK. X 91. 



