Mr. D. Sharpe on Secondary Fossils from South Africa. 199 



Avicula Bainii, Sharpe. PI. XXVIII. fig. 10. 



A. testa subrhomboidali, obliqua, laevigata, medio gibbosa ; antice abbreviata, turaidiuscula ; 

 postice alata, depressa. 



Shell somewhat rhomboidal, oblique, nearly smooth ; gibbous in the middle ; an- 

 terior portion short and tumid ; posterior expanded into a broad fiat wing. 

 Length ^th of an inch ; breadth the same. 

 Found in the lowest strata of the Zwartkop crag. 

 Only one imperfect specimen of the left valve has been seen. 



Modiola Atherstoni, Sharpe. PI. XXVIII. fig. 11. 



M. testa transversim oblonga, gibbosa, concentrice striata, antice obtusa, postice rotundata 

 expansa. 



Shell transversely oblong, gibbous, concentrically striated, short and obtuse in 

 front, widened and rounded posteriorly. 



Length j^th of an inch ; breadth ^^th of an inch. 

 Abundant in the lowest strata of the Zwartkop crag. 



Sanguinolaria ? Africana, Sharpe. PI. XXVIII. fig. 12. 



S. ? testa transversim oblonga, depressa, antice abbreviata rotundata, postice expansa, con- 

 centrice rugosa striataque. 



Shell thin, transversely oblong, depressed ; umbos near the anterior end, which 

 is short and rounded ; posterior end broad and somewhat flattened, with a shallow 

 furrow near the dorsal margin : ornamented with eight or ten broad concentric 

 folds, which are visible in the cast, between which are fine concentric striae. 



Length -njths of an inch ; breadth iijth of an inch. 



Found in the lowest strata of the Zwartkop crag. 



Cyrena ? Bainii, Sharpe. PI. XXVIII. fig. 13. 



C. ? testa transversim ovata, gibbosa, concentrice striata ; umbonibus prominentibus sub- 

 raedianis. 



Shell transversely ovate, gibbous, slightly inequilateral, concentrically wrinkled ; 

 umbos large, a little in advance of the middle. 

 Length f ths of an inch ; breadth ^ an inch. 

 Found in the lowest strata of the Zwartkop crag. 



Trochus Bainii, Sharpe. PI. XXVIII. fig. 14. 



T. testa minuta, pyramidali, imperforata; anfractibus angulatis, longitudinaliter undato- 

 striatis ; infra transversim rugosa : apertura subquadrata : angulo spirali 50°. 



Shell minute, pyramidal, imperforate, with four angular whorls which are 



VOL. VII. — SECOND SERIES. 2 E 



