Brachiopoda jrom the Bokkeveld Beds. 177 



American forms. The shape is rather more subcircular than usual 

 in members of the genus, but the young of B. ovoides (Eaton) from 

 the Oriskany Sandstone* have such a form. The simple radial 

 ornamentation of the surface is met with in several allied genera of 

 this family {Bensselaria, Beachia); and externally the shell much 

 resembles Beachia siiessana Hall,-f but the infolding of the margins 

 is not visible. 



Locality.— {l<io. 149) Assegai Bosch, Eoode Berg, Ladismith. 



EENSSEL^RIA sp. /5. 

 (Plate XXI., fig. 9.) 



A nearly perfect cast of the interior of both valves of another 

 species of Bensselaria (No. 156) comes from Gydo Pass, Ceres. 

 This shell has an elongated oval shape, is biconvex, with the 

 pedicle valve rather deeper than the brachial and furnished with 

 a prominent incurved beak, and there is a trace of a faint narrow 

 median depression along it. The teeth are strong and supported 

 by short dental plates ; the diductor muscular impressions are 

 narrow, elongated and slightly divergent. The surface is marked 

 by 20-24 low weak ribs, strongest near the margins, and the two 

 bordering the weak sinus are continued with equal strength to the 

 beak and have three shorter ribs between them. The brachial valve 

 has no median fold or sinus, and the ribs are uniform. The dental 

 sockets are deep ; the hinge-plate is elevated and cleft down the 

 middle into ti-iangular halves, and slender crura are attached to 

 the inner angles. The marks of the adductors are closely placed 

 and lie just in front of the hinge-plate, and there is a short low 

 septum anterior to them. 



Dimensions. — Length 16 mm. ; width 12 mm. 



Affinities. — This brachiopod externally somewhat resembles Tere- 

 bratula oliviani De Yern.l from the European Devonian, but the 

 internal structure shows it belongs to Bensselceria, and it appears to 

 be similar to B. cumhcrlandus Hall,|; from the Oriskany Sandstone 

 •of North America. 



Locality. — (No. 156) Gydo Pass, Ceres. 



* Hall, PalfEont. N.Y., vol. iii., 1859, p. 4-56, pi. civ., figs. 1-4, pi. ev., ligs. 1-6. 



t Ibid., p. 459, pi. cvii., figs. 1-15. 



\ De Veineuil, Bull. Soc. Geol. France, ii., 1845, p. 470, pi. xiv., lig. 10 a-d. 



I Hall, Palffiont. N.Y., vol. iii., 18.59, p. 464, pi. cviii., fig. 1. 



