68 CALIFORNIA ACADEMY OF SCIENCES. 



Genus Oncop>horus Rudow. (Plate xi.) (The generic 

 name Oncopliorus was proposed by Rudow for a species 

 which has since been transferred to another genus, Eurv- 

 mctopus, but Piaget, retaining the generic name, has 

 grouped under it a number of species presenting the 

 characters following. This genus " sert de transition 

 naturelle entre les genres Docophorus et Nirmus tf une 

 part et /es genres Goniodes et Lipeurus d 'autre part." ) 

 Usually small, 2 mm. being a maximum length among the 

 known species; varying from broad to slender; head 

 conical, clypeus with or without distinct suture, with or 

 without signature; antenna? differing in the sexes, the 

 male antenna longest, and the first three segments with 

 or without appendages ; prothorax but little shorter than 

 the metathorax: leg's short like those of Nirmus; color 

 generally dark brown. But few species (eleven) so far 

 described. 



Suborder AMBLYCERA. 



With the antenna? clavate or capitate, 4-segmented, and 

 with filiform 4-segmented labial palpi. 



Family Gyropid^e. 



Characters of single genus. 



Genus Gyropus Nitzsch. Infesting mammals, tarsi 

 with one claw; temples produced into angulated pro- 

 cesses; mouth parts on the frontal margin of the head; 

 size, small from .7 to 1.2 mm. 



Family Liotheid^e. 



Infesting birds (see Boopia! ); tarsi with two claws; 

 the 4-segmented antennae lying, when not outstretched, 

 in an excavation on the under side of the head. 



Genus Colpocephaluiu Nitzsch. (Plate xii.) Body 

 varying in size from very small (1 mm.) to large (3 mm.), 

 elongate, oval or elliptical; head usually wider than long 



