16 PROCEEDINGS OF THE AMERICAN ACADEMY 



Fam. P0LI0CHERID7E nov. fam. 



Cephalothorax quadrate, not much smaller than the abdomen. 

 Coxre radiating (apparently) from a median line. Abdomen rounded, 

 of equal breadth with the cephalothorax, with very indistinct or no 

 longitudinal sculpturing, and composed of only four segments, of 

 which the basal is very short. IS'o abdominal appendages. 



PoLiocnERA nov. gen. 



Cephalothorax scarcely longer than broad, slightly narrowing an- 

 teriorly, the front square. Legs stout, moderately long. Abdomen 

 full, at base as broad as the cephalothorax, broadening slightly behind, 

 fully rounded, the first segment about one third the length of the 

 others, which are equal. 



Poliocliera jmnctidnta nov. sp. Body minutely, deeply and uni- 

 formly punctate throughout, excepting on the narrow first abdominal 

 segment, which is smooth. Legs similarly punctate. Length 15 mm., 

 greatest breadth 7.5 mm. Mazon Creek, Illinois (R. D. Lacoe, No. 

 1845). A fuller description and figure will be given at another 

 time. 



Fam. ARCrilTARBOID.E Karsch. 



Cephalothorax of variable form, but at least half as large as the 

 abdomen. Coxa? radiating from a middle point or line, or from a tri- 

 angular sternal piece, its base on the abdominal margin. Abdomen 

 orbicular or oval, at base as broad or nearly as broad as the cephalo- 

 thorax, with a lateral ridge on each side converging toward the anus, 

 the surface moderately smooth ; segments seven to nine in number, 

 the basal ones visible below, though often extremely shortened in the 

 middle ; no abdominal appendages. 



Geraphrynus nov. gen. 



Cephalothorax fusiform, angulated in front, nearly as large as the 

 abdomen. Coxa? radiating from a median line. Palpi slenderer than 

 the legs, longer than the cephalothorax, springing from its extreme 

 front and of uniform size tiiroughout. Abdomen subfusiform, com- 

 posed of nine segments, rounded behind, with no constriction at the 

 base ; a large triangular post-thoracic plate, crowding the middle of 

 the first five short segments out of a straight transverse line. Readily 

 distinguished from Architarbus by its produced and angulate cephalo- 

 thorax. 



Geraphrynus carbonarius nov. sp. Cephalothorax faintly punctu- 



