408 Alhany Muspum Records. 



yellowish-bro^vn areola : plastron black and yellow ; length, 

 9.3 cm. darling i. 



4. Postei'ior margin of carapace serrated ; a very large conical 

 tubercle on thigh : forehead covered with numerous small and 

 irregular shields ; shell yellow, shaded with brown on the plas- 

 tron, elegantly freckled and radiated with blackish brown on 

 the carapace ; length, 10 cm. f^ignatus. 



5. Posterior margin of carapace not or but feebly serrated ; 

 a large conical tubercle on thigh : a pair of prefrontal scales ; 

 beak strongly hooked ; colour nearly uniformly dark-reddish or 

 yellowish brown above, plastral shields nearly uniformly dark 

 yellow or brown ; length, 10. o cm. houlengeri. 



II. 6. Carapace very convex, gibbose behind, posterior margin 

 not serrated ; inguinal shield large, in contact with the femoral ; 

 fore limb with four claws; a pair of large prefrontal scales, followed 

 by a smaller frontal ; no enlarged femoral tubercles ; dorsal shields 

 reddish brown, yellowish green in centre ; plastron yellowish 

 with reddish-brown spots ; length, 13.5 cm. nogueyi. 



From the synopsis it will be seen that Homopus houlengeri is 

 a well defined species, perhaps most nearly related to H. signatus; 

 but the latter is conspicuously separated from the other species of 

 Homopus by its freckled carapace, a type of colouration not hinted 

 at elsewhere in the genus. Allowing for slight variations, the 

 characters of the scales on the forehead (prefrontal and frontal) 

 seem to constitute reliable specific distinctions in the genus, and 

 those of four species are represented on the accompanying plate. 

 A strongly marked concavity in the hinder part of the plastron of 

 the male H. houlengeri distinguishes the species from others of the 

 present genus, though common enough elsewhere ; the shell of 

 the male is also flatter than that of the female. In one specimen 4 

 nails where present on one hind liml), and 5 on the other. Though 

 large, the femoral tubercle is not so strongly developed as in 

 H.fe/iioralis : in one specimen, a male, the tubercles are altogether 

 wanting. 



From present indications the species seems to have a very 

 restricted distrilmtion in South Africa, being as yet known from 

 only the adjacent districts of Willowmore, Beaufort West, and 



