7)^ [March, 



The species of this genus are numerous in the Palaearctic and 

 Ethiopian regions, a few being found in America. 



27. Ctenophthalmus agyrtes Heller (1896). 

 (Figs. 57, 58, 59). 



^ . Clasper divided by a sinus into two pi-ocesses (fig. 58) ; upper 

 process pointed, bearing two vej-y long and one or more short bristles ; 

 lower process truncate with the apex sinuate, one slender bristle on the 

 under side. Finger almost pear-shaped, and much larger than the 

 ventral process of the clasper. 



$ . Seventh sternite (fig. 59) with a broad rounded lateral lobe, 

 beneath which there is a more or less distinct short narrow lobe 

 Head of receptaculum seminis twice as long as it is broad, and longer 

 than the tail. 



Perhaps the commonest species in England and Scotland, also 

 received from Ireland. It occurs on the brown rat (Epimys norvegicus) , 

 and the house mouse {Mtis muscnhcs) living in fields, and on the bank 

 Vole {Evotonij/s glareolus), the common shrew {Sorex araneus), and 

 others. 



C. agyrtes exhibits in the British Islands great variation, especially 

 in the shape of the seventh sternite of the ? . 



Ct. agyrtes ab. nobilis Roths. (1898). 



Specimens from the water rat {Arvicola amjphibius) occasionally 

 lose a spine of the genal comb on one or both sides. 



28. Ctenophthalmus bisoctodentatus Kolen. (1863). 

 (Figs. 60, 61, 68). 



(J . Both processes of the clasper (fig. 60) much broader than in 

 agyrtes. The upper one with a larger number of bristles, the lower one 

 truncate, not sinuate, with the upper and lower angles acute. Finger 

 not reaching further upwards than the clasper, broader than in agyrtes 

 and less narrowing towards the apex. 



$ . Seventh sternite broadly rounded (fig. 61). 



Not common in England and Scotland, and unrecorded from 

 Ireland. Occurs on, and in the nests of, the mole {Talpa europaea). 

 Very rarely examples are found on the weasel (Mustela nivalis), and 

 the polecat {Putorius putorins) . 



