1 1 8 Book-lice and Bark-lice ; Biting Bird-lice 



becula, triangular membranous processes projecting laterally from the head and situated 

 one in front of each antenna; temples, the hinder lateral parts of the head; ocular emar- 

 gination, a bending in of the lateral margins of the head just in front of the eyes; labral 

 lobes, short blunt membranous processes projecting laterally from near the front angles 

 of the head; sternal markings, blackish markings, bars or spots, on the ventral aspect of 

 the thorax. 



KEY TO SUBORDERS OF MALLOPHAGA. 



With short slender 3- or 5 -segmented, exposed antennae; no palpi; mandibles 



vertical ISCHNOCERA. 



With short clavate or capitate, 4-segmented antennae concealed in shallow cavities 

 on under side of head; 4-segmented palpi; mandibles horizontal. 



AMBLYCERA. 



KEY TO GENERA OF THE SUBORDER ISCHNOCERA. 

 A. With 3-segmented antennas; tarsi with one claw; infesting mammals only (family 



TrichodectidcE) TRICHODECTES. 



AA. With 5 -segmented antennae; tarsi with two claws; infesting birds only (family 

 Philopterida) . 

 B. Antennae alike in both sexes. 



C. Front deeply angularly notched AKIDOPROCTUS. 



CC. Front convex, truncate, and rarely with a curving emargination, but never 

 angularly notched. 

 D. Body broad and short; head with large movable trabeculae. 



E. Forehead with a broad, transverse membranous flap, project- 

 ing beyond lateral margins of the head in the male, barely 



projecting in the female GIEBELIA. 



EE. Without such membranous flap DOCOPHORUS. 



DD. Body elongate, narrow; head with very small or no trabeculae. 



NIRMUS. 

 BB. Antennae differing in the two sexes. 



C. Body wide, elongate oval to suborbicular. 



D. Temples rounded; tip of abdomen with shallow, curving emargina- 

 tion; antennae with no appendage; third segment unusually long. 



EURYMETOPUS. 



DD. Temples usually angulated; tip of abdomen convex, rarely angularly 

 emarginated with two points. 



E. First antennal segment of male large, and sometimes with 

 an appendage; third segment always with appendage. 



GONIODES. 



EE. First antennal segment of male large, but always without 

 appendage; third segment without appendage. .GONIOCOTES. 

 CC. Body elongate, narrow, sides subparallel. 



D. Antennae and legs long; a semicircular depression in front of 



mouth LIPEURUS. 



DD. Antennas and legs short; depression in front of mouth narrow and 

 elongate, extending as a furrow to the anterior margin of the head. 



ONCOPHORUS. 

 KEY TO GENERA OF THE SUBORDER AMBLYCERA. 



A. Tarsi with one claw; infesting mammals only (family Gyropidce) GYROPUS. 



AA. Tarsi with two claws; infesting birds only (family Liotheidce). 

 B. Ocular emargination distinct, more or less deep. 



