Annals of the Transvaal Museum. 



109 



middle of tlie length, cervical emargiiiatioii shallow, cervical grooves 

 superficial and diverging, postero-lateral margins straight, posterior 

 angle truncate; a few hairs and pits present. Dorsal surface (1 /, 

 with three longitudinal grooves, the median longest ; a few long 

 whitish hairs on the surface, each in a deep pit ; constrictions opposite 

 each of the coxae. Ventral surface like the dorsal; anus a little 

 posterior of the middle of the length ; three long spines on each valve, 

 two posterior and one anterior ; no anal groove ; ano-marginal groove 

 long, genital grooves deep and only slightly divergent, reach almost 

 to the posterior margin ; stigniatic plates large and almost circular ; 

 no caudal festoon, l^osfnim short, base wide and narrow on dorsal 

 surface, with sharp lateral projections; ventral surface nearly semi- 

 circular; hypostome narrower than in adult, with three rows of teeth 

 on each half; mandibles (17, ^7) as in male; palpi short, cylindrical, 

 with numerous stout hairs. Legs short and thick; coxae rectangular, 

 except coxae I, which are triangular; no teeth on coxae; tarsi short 

 and thick, no spurs present. 



Larca. — Bochj OA^al (when unengorged), a little narrowed in 

 front, broadly rounded behind; length 0.3 mm., width 0.3 mm.; 

 when engorged 1.1 mm. to 1.3 mm. long, by 0.9 mm. wide; colour 

 yellowish, with shield darker. Dorsal sliield thin, covering more 

 than half of the dorsal surface, almost as Avide as long ; widely 

 rounded behind ; cervical emargination shallow ; cervical grooves 

 short and deep. ]5otli dorsal and ventral surfaces {VI, n, o) with 

 numerous fine short whitish hairs; aiius large, near posterior quarter; 

 one large spine on posterior part of each valve; stigniatic openings in 

 four pairs, one behind eacli i)air of coxae, and a posterior pair further 

 back; a pair of large spines on the median ventral area opposite I 

 and II intercoxal intervals and opposite coxae III caudal festoons 

 present. Rostrum as wide as long, base an elongate rectangle 

 on dorsal surface, semi-circular on ventral surface; mandibles as in 

 female; hypostome narrow, spatulate, with two rows of six or more 

 teeth on each half; palpi with articles cylindrical, without lateral 

 projections, provided with long hairs ; article IV relatively large, 

 inserted obliquely within and liehind on article III. J-C(js relatiA^ely 

 strong; coxae large and triangular, no teeth present; varsi short and 

 thick, terminating in curves, without spurs; caruncle one-third the 

 length of the claAvs. 



Hosts. — Cattle, mules, horses, donkeys, sheep, goats, and dogs, 

 although cattle are its chief hosts. 



Dr^tnhution . — In South Africa generally, Cape Colony, Orange 

 Eiver Colony, Transvaal, Natal, Ehodesia, German South-West 

 Africa, Madagascar, Mauritius, Congo, Cganda, German East Africa, 

 Mocaniluque, Cape Verde Islands. 



This is one of our commonest ticks in South Africa, and is 

 found nearly everyAvhere. There are Iavo or three generations in 

 each year. It is the transmitter of redAvater of cattle, or Texas fever 

 as it is knoAvn in America, Avhere the type 31. annulatus transmits 

 this disease. In South xlmerica and Australia th? sam- disease 'm4 

 transmitted by other varieties of the same species of tick. 



