TWO NEW LICE. 



257 



The basal plate is longer than broad, with the lateral margins 

 gracefully biconcave. 



There are no separate paramera. Probably the deep band-like 

 pieces (Par) represent modified paramera. At their anterior 

 extremity there is a joint between them and the lower angles of 

 the basal plate. At their posterior extremity they curve inwards 

 and become fused with a remarkable penis consisting of two 

 limbs like a finger and thumb — the longer "finger" (f) being 

 ventral and the "thumb" (t) being dorsal. There is another 

 chitinous piece (JIa) which consists of two limbs that arise from 

 a single small median splint lying in the middle between the two 

 lateral bars of the basal plate, dorsal to the basal plate and about 

 half-way down its length. Each limb runs downwards and 

 outwards so as to underlie the parts named paramera for as 

 far as the penis. The strange form of the latter is probably 

 correlated with some modification of the genitalia of the female. 



Text-figure 8. 



RT 



Polyplax oxyrrliynchus. Mouth-parts. X 252. 

 RT. Rostral teeth. F. Fultura?. P. Pharynx. M. Mandible. T. Tendon. 



In regard to the male copulatory apparatus P. brachyrrhynchus 

 and P. oxyrrliynchus are much nearer to one another than they 

 are to P. spinulosa. 



An attempt a,t homologising these parts with those in the two 

 new species is made in the legend to the figure. 



Mouth-parts. (Text-fig. 8.)— The figure shows the shape of 

 the chitinised fore-part of the alimentary canal, i. e. pharynx 



