42 BRUCE F. CUMMINGS — NONDESCRIPT AXOPLURA AND MALLOPHAGA. 



Genus Laemobothrium, Nitzsch. 



Laemobothrium opisthocomi, sp. nov. (fig. 5). 



This well characterised species from the Hoatzin, of British Guiana, is 

 distinguished by a pronounced sexual dimorphism, the frontal margin of the 

 head in the c? being excavated, as in the genus Akidoproctus, while in the Q it 

 is only concave. The mandibles of the c? are also longer and narrower than 

 those of the Q . Abdomen of the Q long, lanceolate at the end ; of the <$ , 

 shorter and abruptly rounded apical! y. Upper surface smooth and shining, of: 

 an almost uniform brown colour, bare, except at the lateral margins. 



u 



Fig. 5. — Lacinoboihriam opiathocoiui, Cummings, $ ; a, heud and pronotum of $ ; 6, the 



underside of the terminal segments of 9 • 



Head elongate, very narrow in front, broadening out before the antennae ; 

 antennal fossae circular, deep ; temples much produced behind so as to embrace 

 the anterior narrower area of the prothorax. On each promontory of the bay 

 on the frontal margin is a group of about five thick blunt bristles, with three or 

 four finer hairs ; the bay bare of hairs ; on the exterior or lateral margin of each 

 of the promontories, two long hairs and a short one a little further back ; a group 

 of long hairs on each side behind the maxillae, three of which are much longer 

 than the rest ; on the temples the usual series of rows of short hairs, ridges and 



