ORDER ACARINA : THE TICKS 279 



have been made regarding the intrinsic danger of their bite 

 but there is plenty of evidence that it may be very painful, 

 and that it often causes severe and prolonged irritation, and 

 even spreading inflammation and suppuration, so much so 

 as to support the belief that the saliva is toxic. Several 

 species are, however, known to be the ordinary agents in 

 spreading the infection of certain dangerous or fatal 

 spirochaetous diseases of man and birds, which, of course, 

 is a much more serious matter. 



Neumann as well as Nuttall and his colleagues recognise 

 two genera of this subfamily. 



Synopsis of Genera of Argantinae. 



1. Body in ordinary circumstances flat with a thin striated edge which 



is defined by a distinct suture Argas. 



2. Body with a blunt edge which is not in any special way differenti- 



ated or demarcated Omithodorus. 



Argas, Latreille (Gr. apya? = shining). 



The body as a rule is flat and more or less oval, with 

 a thin sharp striated margin, which is defined by a 

 conspicuous suture. General integument finely wrinkled 

 and beset with small chitinous platelets more or less distinctly 

 arranged in radial lines. Capitulum as a rule entirely inferior 

 in adult and nymph. Coxal folds often inconspicuous. 

 Eyes absent. 



Neumann recognises eight species, two of which, namely, 

 A. persicus and A. reflexus, are notorious malefactors. 



Synopsis of Species of Argas (after Neumann). 



(Body elliptical (sides curved) = 2. 



Body oblong (sides straight), culminating anteriorly in a 

 point = 7- 



{Body transversely oval 

 A. vespertilionis (on bats in Europe and Africa). 

 Body elongate oval = 3. 



/Margin of body finely striated = 4- 



\Margin of body formed by quadrangular areolae = A. persicus. 

 r Body flat; wrinkling of integument very plain = 5. 



I Body tumid, elongate ; wrinkling of integument very fine ; coxae 

 of fourth legs near the anterior third of the body 



A. hermanii (Egypt and Abyssinia). 



