250 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [BuU. 



1905. Actoniscus ellipticus, Richardson, Bull. U. S. Nat. 

 Mus., No. 54, p. 634. 



Body rather broadly oval and depressed, twice as long as 

 wide. Head broader in front than behind with antero-lateral 

 angles produced in broad, diverging, rounded lobes, angularly 

 produced in middle line beyond lateral lobes. Eyes small, black, 

 oval, situated at sides of median triangular process. 



Antennse with first joint short; second joint enlarged distally, 

 especially on inner side; third joint scarcely as long as second, 

 clavate, and articulated at an angle with the preceding one ; 

 fourth joint longer than third; fifth still longer, slender, sHghtly 

 bent at the base and so forming an angle with the fourth ; flagel- 

 lum shorter than last joint of peduncle, composed of four joints 

 of which the second and the third are longer than the first which 

 in turn is longer than the fourth ; terminal segment showing 

 indications of another rudimentary segment and tipped with 

 setae. 



First thoracic segment excavated in front for the accommoda- 

 tion of the head ; succeeding segments subequal to the seventh 

 which is the shortest; first segment prolonged laterally to about 

 twice its length on the mid-dorsal line ; the second and in an 

 increasing degree, the succeeding segments, produced backwards 

 at the sides. Legs rather small and weak and of uniform size, 

 ambulatory. 



Abdomen with first two segments having their lateral lamellae 

 obsolete and concealed by the seventh thoracic segment; third, 

 fourth, and fifth segments produced laterally into broad plates 

 which are curved backwards, and whose margins continue the 

 even contour of the thorax ; last segment not as long as wide, 

 rounded posteriorly. Uropods terminal with peduncles which are 

 expanded so that they continue the contour of the body and are 

 larger than the expansions of the fifth segment ; ramus stylif orm 

 and tipped with setse; inner pair arising from near the base of 

 the peduncles and extending very slightly beyond the outer ones 

 which arise from a notch near the middle of the inner margin 

 of the peduncle and surpass slightly the expanded lobe of the 

 peduncle. 



Color, slaty gray. 



Length 4 mm. 



