ISOrODS OF NORTH AMERICA. 



421 



wiflo but sliort, uiul (\\t(MKliiiti; to the end of the second iirticlo of tlio 

 })eduiu'le of the second ])iiii' of aiitciinie; the second ai'ticle is one and 

 a half times lono'er than the first article; the third article is three- 

 fourths as lono- as the second. The flagelluni is c()nii)osed of fourteen 

 articles, and extends to the end of the peduncle of the second pair of 

 antennse. The second pair of antennae have the first three articles 

 short and su])equal; the fourth article is as lon<^- as the first three 

 taken together; the fifth is one and two-thirds times longer than the 

 fourth. The flagellum is composed of about ninety articles, and 

 extends to the ])()sterior margin of the fifth thoi-acic segment, and is 

 10 nnn. long. The maxilli])eds have a pal}) of ti\(^ articles. The palp 



of the niandil>les is composed of 

 /v^;;2^°°''""'"°°°***^ three articles. 



The first segment of the thorax 

 is slightly longer than any of the 

 others, which are subequal. be- 



FlG. 472. — ASELLCS COMMUNIS (AFTER SMITH). 



Fir;. 173.— ASELLUS coMMrxis. 

 u, First leg of male, x 



Hi. /), uropod. X Us- 



ing each 1 nnn. in length. The first segment is Ih^ nnn. long. All 

 the segments, including the first, have small (^i)iinera situated at the 

 antero-lateral angles of the segments. 



The abdomen is composed of two short segments, visible only in 

 th(» middle of the dorsal surface, and a large terminal segment, 5 mm. 

 wide and 4^ nmi. long, with the post-lateral angles i-ounded and the 

 posterior margin produced in a broad triangular process between the 

 uropoda. The uropoda are about as long as the terminal abdominal 

 segment, being 4 mm. long. The peduncle is 2 nnn. in length and is 

 1 mm. wide. The imier branch of the uropoda is l)road and tapers to 

 a narrow, acute extremity. The outer branch is half as wide and is 

 about two-thirds the length of the inner branch; it is also produced 

 to a narrow and pointed extremity. In the female the first pleopoda 

 are attached close together. 



The first pair of legs are prehensile and have the propodus greatly 

 expanded, and the inferior margin produced in one long and one short 

 triangular process. All the other legs are aml)ulatory. 



