Brachiopoda from the Bokkcveld Beds. 173- 



or weakly concave. The surface of the casts shows radiating fine 

 ribs, 70-80 in number near the margin, increasing by bifurcation and 

 rarely by intercalation. The characteristic lines of punctae in the 

 grooves between them are most strongly marked near the margin. 



The interior of the pedicle valve shows strong triangular teeth, 

 and a thin low longitudinal septum extending about a third the 

 length of the valve. The brachial valve possesses a prominent, 

 strong grooved cardinal process and deep dental sockets, and the 

 impressions of the adductor muscles are well marked. The strong 

 punctae near the margin are conspicuous. 



Dimensions. — Pedicle valve, length 14 mm., width 18 mm. ;. 

 brachial valve, length 11 mm., width 16 mm. 



Afflnities. — It is probable that the specimens figured by Sharpe ''■'- 

 as "Chonetes sp. ind." from Warm Bokkeveld are identical with this 

 form. The description and figures given by Hall t of Conrad's 

 species Ch. coronatus agree very closely. 



Localities. — (No. 112) Boschluis Kloof, below 1st Sandstone. 

 (No. 118) ditto. ? (No. 215) Fossiliferous or 1st Sandstone, north 

 of homestead, Uitkomst. ? (No. 220) ditto. 



CHONETES cf. AECEI Ulrich. 

 (Plate XXL, fig. 3.) 



There is one cast (No. 129) of a brachial valve in a nodule from an 

 unknown locality which is identical with the specimens from Warm 

 Bokkeveld (now in the Museum of the Geological Society) mentioned 

 by Sharpe I as " the larger specimens of Chonetes ? " and occurring 

 in a ferruginous nodule. This specimen (No. 129) shows a flat 

 brachial valve of a transverse semi-elliptical shape ; the hinge-line 

 is equal to the greatest breadth, and the cardinal angles are 

 rectangular. The surface of the valve is ornamented by straight 

 low rounded ribs of somewhat irregular size increasing by bifurcation 

 and intercalation to the number of 70-80 round the margin. Between 

 them are regular rows of pustules, best preserved on the posterior 

 two-thirds of the shell. The valve seems to be slightly concave near 

 the middle, and to have traces of cardinal spines along the hinge-line. 



Ulrich's § species Ch. arcei from the Devonian of Bolivia appears 



* Sharpe, Trans. Geol. Soc, ser. 2, vol. vii., pi. xxvi., tig. 14 ( ? figs. 1-3, IG), 

 p. 209. 



t Hall, Palseont. N.Y., vol. iv., 1867, p. 1S3, pi. xxi., figs. 9-12. 



\ Sharpe, Trans. Geol. Soc, ser. 2, vol. vii., p. 210. 



§ Ulrich, Neues Jahrb. f. Min., Beil. Bd. viii., IH'.JS, p. 77, t. iv., figs. 35, 30. 



