42 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxii. 



BB. Antennte differing in the two sexes. 



C. Species wide, with body elongate-oval to suborbicular. 



D. Temporal margins rounded ; last segment of abdomen roundly emar- 

 ginated ; antennae of male without appendage, third segment 



very long Eurymetopus Taschenberg. 



DD. Temporal margins usually angulated; last segment of abdomen 

 convex, rarely angularly emarginated, with two points. 

 E. First segment of antenna of male large, sometimes with an 

 appendage ; third segment always with an appendage. 



Goniocles Nitzsch. 

 EE. First segment of antenna of male enlarged, but always with- 

 out appendage; third segment without appendage; last 

 segment of abdomen always rounded behind. 



Goniocotea Nitzsch. 

 CC. Species elongate, narrow, sides subparallel. 



D. Third segment of antenna of male without an appendage. 



Ornithohius Denny. 

 DD. Third segment of antenna of male with an appendage. 



E. Front deeply angularly notched Bothriometopus Taschenberg. 



EE. Front not angularly notched. 



F. Antenna} and legs long ; a semicircular oral fossa. 



Lipeurus Nitzsch. 

 FF. Antennaj and legs short ; oral fossa narrow, elongate, extend- 

 ing as a furrow to the anterior margin of the head. 



Oncoiiliorus Endow. 



ANALYTICAL KEY TO GENERA OP THE SUBOKDER AMBLYCERA. 



A. Tarsi with one claw; infesting mammals (family G-yropidse) Gyropus Nitzsch. 



AA. Tarsi with two claws; infesting birds (excepting Boopia?) ; (family Liotheidaj). 

 B. Ocular euiargination distinct, more or less deep. 



C. Forehead rounded, without lateral swelling; antennae i^rojecting beyond 



border of the head Colpoceplialum Nitzsch. 



CC. Forehead without strong lateral swellings. 



D. Antennas projecting beyond border of the head; temporal angles 



projecting rectangularly ; eye large and simple .. -Boojjia Piaget. 



DD. Antennae concealed in groove on under side of the head; temporal 



angles rounded or slightly angular ; eye divided by an emargi- 



nation and fleck. 



E. Mesothorax separated from metathorax by a suture. 



Trinoton Nitzsch. 

 EE. Meso- and metathorax fused; no suture. 



Lwmohothrium Nitzsch. 

 BB. Ocular emargination absent or very slight. 



C. Sides of the head straight or slightly concave, with two small, laterally 



projecting labral lobes Physostomum Nitzsch. 



CC. Sides of the head sinuous ; forehead without labral lobes. 



D. Ocular emargination filled by a strong swelling; sternal markings 

 forming a quadrilateral without median blotches. 



NitzscJiia Denny. 



DD. Ocular emargination without swelling, hardly apparent or entirely 



lacking; median blotches on sternum. 



E. Very large; with two 2-pointed appendages on ventral aspect of 



hind head ; anterior coxae with very long lobelike appendages. 



Ancistrona Westwood. 

 EE. Small or medium ; without bipartite appendages of hind head. 



Menopon Nitzsch. 



