4 University of Michigan 



Circoniscus, new genus. 



Description: First pair of antennae very small, incon- 

 spicuous, with three segments. Second pair of antennae short ; 

 flagellum with two segments. Eyes small, with about fift4_i. 

 ocelli. Clypeus straight ; epistome flat ; anterior margin of head 

 forming a thin projecting lamella. 



First segment of thorax wath epimera posteriorly cleft. 

 Terminal segment of abdomen broader than long, triangular. 

 Outer branch of all pleopoda with tracheae. Uropoda ex- 

 tending beyond the terminal abdominal segment; basal seg- 

 ment large, rectangular, flat ; outer ramus conical ; inner ramus 

 long, pointed, slightly flattened. 



This genus belongs in the Family Armadillididae. It is 

 closely allied to Sphaeroniscus Gerstaecker, but differs in hav- 

 ing only two segments in the flagellum of the second antenna. 



Type: Circoniscus gaigci Pearse. 



Circoniscus gaigei, new species. 



Description : Body oblong, very convex, contractile into 

 a ball. Color slaty above, creamy below, a pair of mottled 

 white areas on the dorsal surface of each thoracic segment. 

 Head set in first thoracic segment; front straight, with a re- 

 flected lamellar margin; epistome forming a triangular shield. 

 Kyes small, with fifteen facets. Flagellum of second antenna 

 with three segments. 



First thoracic segment thrice as long as head, longer than 

 any succeeding segment; epimera cleft on lateral margins one- 

 fourth distance from posterior angles; a slight indication of 

 distinct coxopodites just anterior to the clefts. 



First two abdominal segments with the lateral parts con- 

 cealed, the three following segments continuing the outline of 



