Antals of the Transvaal Museum. 
109 
middle of the length, cervical emargination shallow, cervical grooves 
superficial and diverging, postero-lateral margins straight, posterior 
angle truncate; a few hairs and pits present. Dorsal surface (17, m) 
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 ; stigmatic plates large and almost circular; 
no caudal festoon. Rostrum 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, jj) 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. 
Larva. — Body oval (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. w T ide ; colour 
yellowish, with shield darker. Dorsal shield thin, covering more 
than half of the dorsal surface, almost as wide as long ; widely 
xounded behind; cervical emargination shallow; cervical grooves 
short and deep. Both dorsal and ventral surfaces (17, n, o) with 
numerous fine short whitish hairs ; anus large, near posterior quarter ; 
one large spine on posterior part of each valve ; stigmatic openings in 
four pairs, one behind each pair 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 a,s 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 IY relatively large, 
inserted obliquely within and behind on article III. Legs relatively 
strong ; coxae large and triangular, no teeth present ; tarsi short and 
thick, terminating in curves, without spurs; caruncle one-third the 
length of the claws. 
Hosts. — Cattle, mules, horses, donkeys, sheep, goats, and dogs, 
although cattle are its chief hosts. 
Distribution. — In South Africa generally, Cape Colony, Orange 
River Colony, Transvaal, Natal, Rhodesia, German South-West 
Africa, Madagascar, Mauritius, Congo, Uganda, German East Africa, 
Mocambique, Cape Yerde Islands. 
This is one of our commonest ticks in South Africa, and is 
found nearly everywhere. There are two or three generations in 
each year. It is the transmitter of redwater of cattle, or Texas fever 
as it is known in America, where the type M. annul atus transmits 
this disease. In South America and Australia the same disease G- 
■transmitted by other varieties of the same species of tick. 
