ART. 20 TAXONOMY OP BITING LICE DEWING S 



abdominal sternites. He also notes that in the development of the 

 mesothorax and the shape of the head these four genera have much 

 in common. His diagnosis of the genus is good, but a restudy of the 

 species, and also those of Eureuni necessitates new definitions for 

 the old characters and the addition of new characters. The genua 

 Dennyus is redescribed as follows: 



Antennal fossae partly roofed over above by an expansion of the 

 head; eyes double, the two conreas of one side being partly fused; 

 esophageal sclerite small or wanting; temporal lobes pronounced, 

 quadrangular. 



Prothorax rather narrow, but pronotum expanded laterally into a 

 pair of spine-bearing lobes; prosternal plate well developed, with 

 heavy chitinous borders. Mesothorax small but usually distinct 

 and spearated from metathorax by a dorsal suture. 



Abdomen long; pleurites each typically with a marginal row of 

 spines and a small tuft of long hairlike setae; tergites bare except 

 for a posterior marginal row of setae. Some of the abdominal 

 sternites with patches of setae of about the same size as those cloth- 

 ing the body. 



Genital armature of male symmetrical, with long, narrow basal 

 plate ; parameres not united, free, clasperlike ; endomeres short, never 

 clasperlike; penis not developed. 



Legs of the first pair short, others long; first femora very short, 

 frequently as broad as long ; last femora very long, each with a patch 

 of setae below. All tibiae with an indistinct pseudarticulation some- 

 what beyond the middle. 



Subgenus Dennyus Neumann 



The most important characters of the typical subgenus of Dennyus 

 have been given in the key. It should be added, however, that the 

 species composing this subgenus are remarkably alike, not only in 

 their subgeneric characters but also in their specific characters. 

 Hence there has been and is yet great confusion in regard to the 

 synonjnmy of the species. Neither Harrison nor Ferris was able 

 entirely to clear up the synonymy of the species. It had been the 

 hope of the present writer to make a definite contribution along this 

 line, but the inability to get hold of the types has prevented. All 

 of the lots of specimens of the subgenus Dennyus examined by the 

 writer belong to three species, of which two are new. They are sep- 

 arated by the following key. 



KEX TO SPECIES OF SUBGENUS DENNYUS DESCRIBED IN THIS PAPER 



1.* Setae on central hyaline area of prosternal plate short and spikelike and 



about 10 in number D. richmondi, new species. 



Setae on central hyaline area of prosternal plate long, setiform and much 

 less than 10 in number 2. 



