Aj^nals of the Tkansvaal Museum. 



85 



coxae contiguous, decreasing in size from the first to the fourth pair,, 

 striated on the ventral surface, granular on the dorsal and posterior 

 surfaces, with a transverse granular pad at the distal extremity ; the 

 second article wider than long in the first two pairs of legs, longer 

 than wide in the other two pairs ; dentate on distal edge, with a 

 distal granular pad; third article wider at the distal extremity; fourth 

 article short in the first three pairs of legs, twice as long in the 

 fourth pair ; fifth article provided on its dorsal border, in the first 

 three pairs, with three successive teeth, the two proximal quadrangular,, 

 the distal conical ; on the fourth pair only tw o conical teeth ; tarsi 

 provided on their dorsal border with three teeth, one basal (on the 

 proximal pseudo-article of the last three pairs of legs), the second 

 close to the first (])oth quadrangular), the third conical near the distal 

 extremity; swollen or blunt hairs fairly numerous, and a few spines 

 on all the articles except the coxae. 



Hosts. — Man, goats, sheep, and other mammals. 



Hahifat. — Sonialiland, Kilimanjaro, Congo, Egypt, South-East 

 Africa, India. It is also said to occur in (jermau 8outh-West 

 Africa. It is usually found in loose soil in the shade of trees 

 and rocks in desert tracts, places chosen by animals for rest. 



There has been consideral)le confusion l)etween this tick, its variety 

 caecus, and 0. )no//hat(f. I have seen only specimens of O. sarifjuyi 

 caecus, but after a careful study of the pu])lished descrii)tions and 

 illustrations of the other two, I have come to the conclusion that if 

 mouhdia can be considered as separate from sarigu}/i\ it must l)e only 

 as a variety of the latter species. The main difference between these 

 two seems to be that niouhnfd lacks the eye spots, which are present 

 in sdvigniji, and that the inner apophysis of the mandil>les are 

 bidentatc, while in sarigniji they are uni-denUite . Movlxita cannot 

 be considered as identical with savignyi caecus, although both forms 

 lack eyes, because caecus agrees with savignyi in having the inner 

 apophysis of the mandibles mii-dentafe . The form of the last two 

 articles of the legs of these three forms, which is a character considered 

 in other species, seems to differ in no essential detail. 



A study of the life history of luouhata and caecus shows that they 

 agree in all but one point. Button and Todd (1905) state that the 

 larva of uujuJjata sheds the egg-shell and moults to the nymphal 

 octopod stage at the same time. Such is not the case with caecus. 

 The larva liatches as a true larva with six legs. It crawls about for 

 a short time, but does not feed ; then it becomes motionless, the outer 

 skin dries, and, after a time, the octopod nymph emerges. 



Taking all these points into consideration, it seems that we must 

 consider these three forms as distinct, l)ut the differences do not seem 

 to me to be of importance enough to consider them as distinct species. 

 My opinion is that both caeci/s and mouhata are merely varieties of 

 savignyi, and should be known as 0. savignyi caecus and 0. savignyi 

 mouJjata. 



