586 MEDICAL ENTOMOLOGY 



the above key ; it is characterized as follows : Body round ; camerostome 

 visible from the dorsal surface ; tarsus I with two dorsal humps, the one 

 situated at the proximal end of the segment pointed and slightly turned 

 towards the extremity of the tarsus. Tarsus IV has only one hump at 

 its distal extremity. 



Ornithodoms savignyi, Audoin. Adult. (Plate LXXII, figs. 4 and 5.) 

 Body as broad in front as behind. Integument leathery and covered 

 with distinct non-contiguous mammillae, with numerous short hairs 

 interspersed. Supracoxal folds well marked, and with two eyes on each 

 side, the first pair between coxa I and II, and the second between coxa 

 II and III. Coxal folds less marked. Pre-anal groove distinct. Basis 

 capituli broader than long and shorter than the rest of the rostrum ; 

 hypostome with six principle rows of teeth, the external the stoutest. 

 Palps with first and second segments of equal length ; third segment the 

 shortest. Coxae contiguous; protarsus and tarsus of legs I, II and III 

 with three well marked humps ; the two proximal humps on tarsus of leg 

 IV are close to each other, while the third is separated by an interval 

 equal to about two and a half times the distance between the first and 

 second. Length 5 to 12 mm., width 4 to 8*5 mm. The male and female 

 resemble each other, except that the former is smaller, its genital orifice 

 being markedly smaller. In the female it is a broad transverse slit which 

 can be made to gape, and is guarded by two flap-like valves ; in the male 

 the orifice is oval and the valves are absent. 



This species is widely distributed, and is found in Arabia, Nubia, 

 Egypt, Somaliland, Abyssinia, German East Africa, Cape Colony, 



Rhodesia, Bechuanaland, and- Portuguese East Africa. 

 Geographical _ , . . . _, 



distribution India it is common in the Madras Presidency, in 



Gujarat and in many parts of the Bombay Presidency. 

 In Aden it is widely distributed throughout the Hinterland, where its 

 principle host is the camel. 



This tick often attacks man, and the senior author has seen extensive 

 ecchymosis following its bite, but never any constitutional symptoms. 



Bionomics: Relation ItS blte is PP ularl y believed to be the cause of the 

 to Disease Aden Sore, but there is no evidence to support this 



belief. Throughout the Aden Hinterland and in Somali- 

 land savignyi is abundant along all the camel caravan tracks, and all the 

 resting places literally swarm with the immature stages. The adults are 

 commonly seen attached around the anus of the camel. In South 

 India it is common in the sand under large trees, particularly in those 

 places where cattle rest ; the blood of these animals appears to be its 



