81 



i 

 IXODIDJE. 



The Ixodidse, or ticks, are rather large, flat, leathery-skinned 

 mites, which suck the blood of various animals. In the male the 

 dorsum of the body is nearly covered by a corneous shield, while in 

 the female this shield occupies only the anterior part of the body. 

 In the female the body swells to enormous proportions as she engurges 

 herself on the blood of the host. At the posterior margin of the body 

 there are in many forms a series of lobes or festoons. There is no 

 species of tick that is commonly found on rats, but four species that 

 normally infest other animals have been taken from them. 



FIG. 8. Mite (Lxlaps ecliidninus). 



1. On the venter is a groove in front of the anus and extending back each side; no 



festoons to posterior margin of body; palpi rather long Ixodes ritinus. 



On the venter there is no groove in front of the anus, but usually one behind; 

 festoons distinct in males and unengorged females 2 



2. Palpi very short with transverse ridges; shield of female narrowed hehind eyes; 



stigmal plate nearly round Margaropus annulatus. 



Palpi short, without transverse ridges; shield of female not narrowed behind eyes; 



stigmal plate comma shaped Rhipicephalus sanguineus. 



Palpi elongate, without ridges; shield of female broad; stigmal plate oval, 



Hyalomma aegypticum. 



Ixodes ricinus Linne. 



The shield of the female is elliptical, plainly longer than broad, 

 sides not suddenly narrowed behind, and there is no eye-spot at each 

 lateral corner. The coxa I has a long sharp spine. 



This is a common European tick found on sheep, cattle, dogs, etc., 

 and it has been taken a few times in this country. Neumann has 

 >rded its capture from Mus decumans. 



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