Annals of the Transvaal Museum 
75 
j Preliminary Key to the S. African species of the genus Acanthodon 
(= Ctenolophus Purcell + Gorgyrella Purcell) based on the characters of 
adult Males. 
1. Tibia I longer than metatarsus I. 
(a) Tibia of palp about twice as long as deep, the excavation with a more 
j or less continuous strip of short spines arranged in a single row in the middle. 
Band of spines on anterior surface of patella IV stretching the whole length 
of the segment but in the distal three-fifths there is only a single row and the 
l! distal spine is a good distance from its neighbour; III with about eighteen 
spinules anteriorly, including those on the distal edge. Ocular area extending 
over about one-third of the distance between the anterior margin of the 
carapace and the fovea: frontal eyes about one-quarter of a diameter apart or 
| a trifle more: posterior medians two diameters apart or slightly more and 
I diameters or a little less distant from the posterior laterals. Tibia I 4-25 mm. 
1 long, metatarsus I 3-75 mm. (loc.?). A. thorelli O. P. Cambr. 1 
(. b ) Frontal eyes one-sixth of a diameter apart. (For other characters see 
description.) [East London.] A. gracilipes sp. nov. 
2. Tibia I subequal to metatarsus I . 
A. With two pairs of sternal sigilla. 
(a 1 ) Tibia I only slightly incrassated, the distal tubercle bearing a short 
black pointed process: metatarsus I practically straight and not incrassated 
or bent at any point : tarsus I only weakly scopulate, without spines on either 
side or only one weak one posteriorly. Patella III with a band of about twenty 
spines on its anterior surface and a strip of six or seven weaker ones dorsally, 
apart from those on the distal edges; IV with short spines over J-f of the 
length of the segment. Coxa III with a band of stiffish. setae along its post- 
ventral border. Tibia of palp a trifle more than twice as long as deep, the 
excavation bordered by a continuous band of spinules : tarsus with a group of 
spines at the apex superiorly. Ocular area extending a little more than one- 
third of the distance from the anterior margin of the carapace to the fovea: 
frontal eyes about one-quarter of a diameter apart, larger than the anterior 
medians, the quadrangle formed by these four eyes being very slightly wider 
in front. Length of carapace 5-3 mm., of tibia I 5-15. (Grahams town.) 
A . microps Hewitt. 
(b 1 ) Similar to microps but smaller (length of carapace 4-5), and differing 
as follows: metatarsus I seen from the side is distinctly bowed, and the inner 
lateral surface carries a number of stout bristles or spiniform setae (wanting 
in microps ), only absent near the base of the segment: tarsus I strongly 
scopulate. (East London.) A. hirsutus sp. nov. 
(c 1 ) Metatarsus I very distinctly curved proximally when seen from the 
side, concave also internally at the base and slightly incrassated internally at 
the end of the basal fourth, the eminence bearing one short spine, and 3-4 
stout spiniform setae. Excavation of tibia of palp furnished with a broad 
semicircular band of short close-set spinules. Area formed by the frontal and 
anterior median eyes very slightly wider in front than behind. (Durban.) 
A. cregoei Purcell 2 . 
1 I have examined the type in the British Museum. 
2 Species unknown to me. 
