636 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



angle of the basal article on the underside; it is about twice as long as 

 the outer branch, but does not extend beyond the extremity of the 

 outer branch. 



The legs are all similar in structure and ambulatory. 



In color it is a reddish brown with wavy lines 

 of a light yellow on either side of the median line. 

 About ten specimens were collected in Oak- 

 land, California, by Prof. Josua Lindahl. 



This species is ver}- similar to the type and 

 onl}^ described species of the genus, Actonhvus 

 elUptlcii>< Harger, but differs in having the sur- 

 face of the body covered with low tubercles; 

 in having the three lobes of the head anteriorly 

 truncate, while in A. ellipticus the median one 

 is acutely pointed, the lateral ones rounded; in 

 having the fourth and fifth articles of the 

 peduncle of the antenna^ subequal, and the sec- 

 ond article of the flagellum longest, the terminal 

 article not minute, but as long as the preceding 

 one; in having the post-lateral angles of the 

 first thoracic segment produced in acute proc- 

 esses, and in having the sixth or terminal segment of the abdomen 

 triangular rather than rounded. 



This species is named in honor of Prof. Josua Lindahl, from whom 

 the specimens were received. 



Fig. ri79.— Acton i.S(.:n 



DAHLI. ■ 13. 



Fig. 680.— ACTONISCUS LINDAHLI. (), M.\XILLIPED. X62. b, FIRST MAXILLA. X 62. r, SECOND MAX- 

 ILLA. X 62. rf, Mandible, x 62. e, Mandible, x 62. 



" The types are in the museum of the Cincinnati Societ}^ of Natural 

 History. Cat. No. 16365. 



IIB. Genus AC ANTHONISCUS (White) Kinahan. 



"Body somewhat glol)ose; head rounded; no true median or lateral 

 lobes; a pair of small spurious lateral lobes beneath or])its, arising 

 from production of antennar}^ ring; external antennae {'i)\ internal 

 antennae three-jointed. 



" Cephalothorax : coxte well marked. Abdomen: coxte of first and 

 second somite obsolete; third to fifth narrow. 



