:8G 



Anxals of the Teaxsvaal Museum. 



OENITHODOEOS SAYIGNYI, var. CAECTTS, {NEUMANN.) 

 0. sacignyi (Auclouin)^ var. coecus, NeTimaiin (1901). 

 Plate I, figures a to e; Plate III, figurevS g, 



Tliis variety differs from tlie type in the following points : Tlie 

 l)ody is generally more swollen; tlie eyes are absent. 



The females are 9 to 11.5 mm. long by 6.5 to 8.5 mm. wide; 

 males, 8.5 to 9 mm. long by 6.5 to 7 mm. wide. The genital opening 

 ^of the female is long and narrow, opposite the posterior edge of 

 coxae I, that of the male is short and wide, and opposite coxae II. 



Nymph resembles the adnlt in all respects regarding shape, 

 integument, and grooves. The colour is light yellow when first 

 transformed from the larva ; later, deep bluish after feeding ; legs 

 translucent; length when first transformed 1 to 1.5 mm., width 0.75 

 to 1 mm. Genital pore lacking. Rostrum, as in adult, projects some- 

 what beyond anterior edge of body. Mandibles as in male and female ; 

 hypostome (//, /) in young nymph bears five transverse rows of two 

 teeth each on each half, with numerous crenulations, posterior teeth 

 •extending furthest along the outer margin. Stigmata as in adult; 

 anus circular, one large spine on each valve near its anterior end. 

 Legs as in adult. 



Larva. — When first hatched, nearly circular in outline, sides 

 slightly depressed and parallel, 1 mm. long and half as thick as long; 

 later, it expands slightly, becomes thinner, and, when ready to 

 transform to nymph, is 1 to 1.5 mm. long by 0.75 to 1 mm. wide. 

 Colour light brownish yellow; legs translucent. Integument without 

 papillae, but possessing fine transverse striations ; no grooves and no 

 hairs; sexual groove lacking. Rostrum projects beyond anterior edge 

 nearly its whole length ; mandibles often cannot be made out plainly, 

 but bear same characters as adults; hypostome (//, e) small, deeply 

 divided at tip, small denticles at tip, then four rows of teeth, four 

 teeth each to inner rows, but only three teeth in outer rows ; two 

 large spines at base. Palpi thick, cylindrical ; articles all short and 

 thick, a few stout spines near distal portions of articles. No 

 indications of stigmata. Anus always concealed by a mass of white 

 secretions in rectum. Legii stout; no tubercles present as in adults. 

 Becomes whitish before moulting time. 



Eggs nearly spherical in .shape, 0.9 mm. long by 0.8 mm. wide; 

 dark reddish brown in colour; surface smooth and shiny. 



Hosts. — Man, fowls, sheep, goats, cattle, and other animals. 



Habitat. — Eastern Africa, including German East Africa, 

 Mocanibique, Angola, German South- West Africa, Upper Zambesi, 

 Congo, TransA^aal, Natal, Cape Colony, Nubia, Abyssinia, Egypt, 

 Southern Basin of Lake Tchad. Besides being found in sand in 

 desert-like places, it is very common in native huts, where it attacks 

 the inhabitants. 



This tick was originally given the name of Tamvan by 

 Livingstone, being the name employed by certain native tribes along 

 the Zambesi. In Sesuto it is known as MaJxarulu . It occurs in the 

 warmer parts of the Transvaal, where it of fen becomes a serious 

 nuisance at outspans and. in native huts, and occasionally in houses of 

 Avhites. The life history is much like that of Argas persicdis, i.e. 



