7o6 



ARTHROFODA 



It is common in Africa, India, and Aden, and perhaps else- 

 where. 



Morphology. — Ornithodoros, with two pairs of eyes appearing as 

 circular, smooth, convex elevations, situated on the supracoxal fold 

 above the bases of the first pair of legs, and between those of the 

 second and third pairs. Body oval, constricted slightly between the 

 third and fourth pairs of legs, yellow in colour when young, and 

 blackish-brown when old. Integument covered with irregular hemi- 

 spherical prominences pointed at their summits, between which are 

 narrow depressions with hairs. Capitulum embedded in an infundi- 

 buliform camerostome, from which it is separated by a deep groove, 

 in the dorsal portion of which can be seen the opening of the cephalic 

 gland. Mandibles with a simple claw-like internal apophysis, and 

 without middle apophysis. Teeth of the hypostome arranged in 

 three longitudinal parallel rows. Two spines at the base of the 

 hyposome, which is large. 



Dorsum of the body marked by two transverse furrows, one just 

 in front of the posterior border, and the other situate farther 

 forward, marking off a median elevation with a central depression, 

 and seven similar depressions, each of which becomes a deep sulcus 

 posteriorly. 



The ventral surface shows a well-marked pre-anal furrow, which 

 laterally meets the supracoxal sulcus, which runs round the anterior 

 aspect of the body as a well-marked groove, defining the supra- 

 coxal fold, on which the eyes are situate. Behind the anus are 

 three symmetrical longitudinal grooves, while a short V-shaped 

 depression abuts on the anus. The genital papiUa is well marked, 

 and surrounds the wide transverse opening. 



The fourth pair of legs is one and a half times as long as the first. 

 The coxae are contiguous, and diminish in size from the first to 

 the fourth, and the first has the opening of the coxal gland. 

 Christophers has observed that the fluid from this gland is alkaline 

 and prevents coagulation of the blood. The stigmata are placed 

 behind and above the supracoxal folds. The fifth joints of the 

 first three pairs of legs v/ith three teeth, the two proximal quad- 

 rangular, and the distal conical. 



This tick is very hardy, and is said to be able to live for many 

 months without food or moisture. It attacks human beings, and 

 is found in Africa and India. 



Pathogenicity.— Not known. 



Ornithodoros moubata Murray, 1877. 



Synonyms. — Argas moubata Murray, 1877 ; Ixodes moubata Cobbold, 

 1882; Ornithodoros savignyi var. cceca Neumann, 1901. 



0. moubata of importance as the spreader of Spiroschaudinnia 

 duttoni, the cause of Dutton's relapsing fever, or African tick fever. 

 The tick is distributed widely in Africa, where it is called bibo in 

 Uganda, moubata in Angola, and tampan in Zambesi. Christy has 

 described a similar tick in Brazil. 



