582 MEDICAL ENTOMOLOGY 



marked with numerous discs arranged in groups as shown in the figure. 

 The margin is formed of short rectangular festoons, each enclosing a 

 circular pit. Spiracles small and crescentic in shape, equal to about 

 half the width of the anal ring. Basis capituli broader than long ; 

 hypostome as long as the base, and armed with four principal rows of 

 teeth. Palps about twice as long as hypostome, second segment the 

 longest. Coxa I in female distinctly separated from coxa II. Tarsi with 

 a dorsal protuberance. The sexes are much alike, but the male is smaller 

 and narrower than the female, its genital orifice is inconspicuous and more 

 posterior in position, and is surrounded by an anal ring. The genital 

 orifice in the female is large and slit-like. Length 4 to 10 mm. ; width 

 2'5 to 6 mm. 



Argas persicus can always be distinguished from reflexus by its shape, 

 the latter being much narrower anteriorly ; the integument is not so 

 finely wrinkled in the former, and coxa I is distinctly separated from 

 coxa II, the other three being contiguous. In reflexus all the coxae are 

 contiguous. Neumann recognizes a variety miniatus in which the integu- 

 mentary folds are covered with three to five series of discs, some distance 

 from the margin, and more marked posteriorly ; the festoons of the 

 border are as a rule contiguous. 



This species is found throughout the world, and is always associated 



with the fowl. In Persia and Egypt it is said to attack man and to inflict 



a dangerous bite ; there is however no definite proof 



Geographical t j lat j t carr i es anv disease germ to man. In the case 



Distribution: r , . . . . 



Relation to Disease ot tne towl !t 1S a senous P est > killing the birds not 

 only by massive infection but by infecting them with 

 Spirochaetae marchoitxi, Nuttall. This spirochaetosis of fowls was first 

 discovered in Brazil by Marchoux and Salimbene ; it is a fatal disease, 

 and in many parts of the world seriously interferes with poultry farming. 

 Spirochaetosis in geese has been recorded from the Trans-Caucasus, and is 

 probably transmitted by Argas reflexus. 



Argas vespertilionis, Latr. Male. (Plate LXXIV, fig. 5.) Flat and 

 broadly oval, with a marked convexity towards the middle third ; uniform- 

 ly brown with a reddish brown margin. Surface marked with fine 

 granulations, and longitudinally radiating discs arranged in about twenty- 

 two lines on the dorsal surface and twenty-eight on the ventral. Anterior 

 end of the body pointed but without any hood. Supracoxal fold moder- 

 ately marked and extending to a little beyond coxa IV ; coxal fold 

 distinct, extending from coxa I to the lower border of coxa IV. Anus 

 situated about the centre of the body, with a well marked transverse fold 



