176 Annals of the South African Museum. 



large slab (No. 221) from Gamka Poort which must be referred to 

 a species of Bliynchonella {Gamarotcecliia). It is convex from back 

 to front with a strong incurved beak and only a very faintly indicated 

 median sinus. The surface is ornamented with about 18 simple low 

 ribs of which four lie in the sinus. The muscular impressions in 

 the beak are strongly developed, and the teeth are rather widely 

 separated. 



Dimensions. — Length 8 mm. ; width 11 mm. 



Affinities. — This form may be allied to Bh. implexa Sow.* from the 

 Middle Devonian of England, and there are some American species 

 {Bh. horsfordi Hall, and Bh. sappho Hall) f from the Upper Helder- 

 berg and Hamilton Groups which seem to bear some resemblance 

 to it. 



Localitii.—{^o. 221) Gamka Poort. 



Family CENTKONELLID^. 



EENSSELiEEIA sp. «. 

 (Plate XXL, fig. 8.) 



On one block of sandstone (No. 149) there are the internal casts- 

 of two brachial valves of a species of a large plicated brachiopod 

 which must be referred to BcnssclcBria or some allied genus. The 

 valves are rather imperfect along their anterior margins, but are 

 apparently of suborbicular shape ; they are gently convex, the 

 greatest convexity being just in front of the small inconspicuous 

 beak, the hinge-line is regularly curved, and the surface of the shell 

 is ornamented with 30-40 simple, straight, radiating, low, rounded 

 and equal ribs separated by narrower grooves. There is a thick 

 elevated hinge-plate, notched anteriorly and swollen and bilobed 

 posteriorly; a broad rounded ridge continued forwards into a thin 

 vertical septum lies in front of it, extending about one-fourth the 

 length of the valve. The bases of the crura are seen, but their 

 course and length cannot be determined. 



Dimensions. — Length about 30 mm. ; width about 32 mm. 



Affinities. — As far as the structure of the hinge-apparatus and 

 interior can be made out it agrees with that of Bensselceria, the 

 bilobation of the hinge-plate being well- shown in some North 



* Davidson, Brit. Foss. Biach., vol. iii., p. 67, pi. xiv., figs. 7-10. 

 t Hall, PaliBont. N.Y., vol. iv., 1867, pp. 339, 340, pi. liv. 



