104 
Annals of the Transvaal Museum 
Ceratogyrus dolichocephalus sp. nov. (PI. I, fig. d and PI. II, fig. a). 
The types are two female specimens from Victoria, S. Rhodesia, collected 
by Miss S. E. A. Ambrose and Master R. H. Ambrose. 
Colour. The general colour of body and appendages dorsally is brown. The 
long hairs have a rufous tinge : this is very marked on the upper surface of the 
abdomen in its hinder half. The carapace has conspicuous thin pale radial 
stripes. Ventrally, the sternum and coxae of legs and palps are blackish brown : 
the femora of the first two pairs of legs and of the palps are also very dark, the 
patellae and tibiae being brown. The ventral surface of the abdomen, in- 
cluding the lung opercula, is dark brown but the genital sternite is yellow. 
Carapace longer than the tibia and metatarsus of the first leg and sub- 
equal to the tibia and metatarsus of the fourth leg. The horn of the fovea is 
not separated off from the rest of the carapace by a continuous groove all 
round its base, for the limiting groove is U-shaped, and the horn thus appears 
to be a backward extension of the head region: the head region from the 
ocular tubercle to the horn is fairly well raised from the rest of the carapace, 
and in side view the outline of this region is practically a straight line from 
the hind margin of the ocular tubercle to the end of the horn, the latter being 
only a trifle raised above that line. The apex of the horn is obtuse, and pos- 
teriorly descends suddenly so that the horn presents practically no free ventral 
portion. 
Legs. The tibia of the first leg is decidedly longer than the metatarsus of 
that leg, and just a trifle longer than the tibia of the fourth leg. 
Measurements. Length of carapace 20-9, breadth of carapace 16-1, distance 
from anterior margin of carapace to apex of the foveal horn 16-8, distance from 
anterior margin of carapace to the U-shaped groove margining the tubercle 
12-5, distance from base of tubercle to hind margin of the carapace, measured 
along the median line 3-9, length of tibia I 10, of tibia IV 9*6, of metatarsus I 9, 
of metatarsus IV 11-5, breadth of foveal horn 4, length of apical segment of 
posterior spinners 3-1, breadth of ocular tubercle 2-65. 
The Albany Museum has a specimen of this form from Salisbury, collected 
by Mr C. von Hirschberg. 
The species is of particular interest as it seems to be primitive with regard 
to the characters of the foveal horn, and connects the more typical species of 
Ceratogyrus with those of Pterinochilus . It clearly points to the conclusion 
that the genus Ceratogyrus originated from a Pterinochilus-like ancestor which 
had a strongly procurved fovea. The characters of a male, which presumably 
belongs to this species, afford almost convincing evidence of this, for the 
adult male is quite devoid of a tubercle as such, this organ being represented 
by the undifferentiated portion of the cephalothorax which is included within 
the U-shaped groove of the strongly procurved fovea. 
Male. 
Mr C. von Hirschberg has collected what seems to be the male of this species 
at Salisbury. But for the fact that it was taken in the same neighbourhood as 
a large female of dolichocephalus , I would have hesitated to refer it to this 
species or even to the genus Ceratogyrus. However, it may prove to be identical 
with C. marshalli Pocock, also taken at Salisbury ( Proc . Zool. Soc. 1897, p. 754* 
PI. XLIII, figs. 2-2 h), but according to Pocock’s description and figure that 
species has a distinct, but small, foveal tubercle. 
