14 



Genus Argas 



The integument, in this and all other species of Argas, is of a uniform 

 pale yellow colour, and the darker tints generally observable are 

 entirely due to the ingested blood. Thus the partially fed living 

 specimen appears of a leaden colour, with yellow margin, pale legs and 

 capitulum. Further feeding increases the darkened area and deepens 

 its hue to a blackish tint which may appear more or less red in preserved 

 specimens. The radiating series of discs (seen in Figs. 3, 4, 22, 23) 

 correspond to intervals between the digestive caeca, and serve for the 

 attachment of muscles. 



Fig. 5. 



Fig. 6. 



Fig. 7. 



Fig. 5. A. persicus. Portion of integument from posterior dorsal border of female, 



x 44. Original N. 

 Fig. 6. A. persicius. A disc ("fossette") of medium size, x 110 (Nn. 1896, fig. 17: 



A. sanchezi). 

 Fig. 7. A. persicus. Detail of integument showing a disc and irregular smooth areas bearing 



hairs. From dorsum of adult, highly magnified. Original N. and W. 



Fig. 8. 



Fig. 9. 



* *»• "• r lg. ». 



Fig. 8. A. perticus. Integumental hair, x 500. N. 

 Fig. 9. A. persicus. Anus, x 95 (Nn. 1896, fig. 8, of A. americanus), 



