404 Amiah of the South African Museum. 



SCAPHIOCGELIA ? AFEICANA vav. nov. Elizabetha. 

 (PI. XLVIII., figs. 10-14.) 



A dark iron-stained sandstone from Eiet Kuil (div. of Uitenhage), 

 near Port Elizabeth, is crowded with the crushed and fragmentary 

 shells of a large Scaphiocoelia, not clearly separable from the species 

 which has been named Sc. africana. The specimens are all more 

 or less imperfect, and are in the condition either of internal casts or 

 impressions of the external surface. The shell is of large size, and 

 as far as can be ascertained generally measures from 50-70 mm. 

 in length. By piecing together the evidence from many specimens 

 a fairly complete diagnosis can be drawn up. 



Shell elongated-oval in shape ; brachial valve flattened or slightly 

 concave, with small inconspicuous beak ; pedicle-valve convex, with 

 high incurved prominent beak, acute and perforated at its apex. 

 Interior of brachial valve with very large swollen hinge-plate, divided 

 medially by deep groove or slit into two rounded subtriangular 

 prominent cushions more or less fused together below and each 

 produced anteriorly at its inner angle into a slender crural process 

 (of unknown length). Dental sockets deep. A low broad rounded 

 indefinite median ridge runs forward from the cardinal plate for a 

 short distance, dying out between the slightly impressed elongated 

 oval adductor scars, divisible into two overlapping pairs; the pos- 

 terior end of the scars is more deeply impressed than the anterior, 

 and where they abut against the anterior face of the cardinal plate 

 the latter is hollowed out into a deep pit on each side of the median 

 ridge. 



Interior of pedicle-valve shows a pair of strong triangular dental 

 plates, thickened and notched on their free anterior edges and 

 embracing on each side the cardinal plate of the opposite valve. 

 Between the dental plates the shell of the beak is somewhat 

 thickened internally (as in Sc. africana). A large concave pseudo- 

 area, vertical or steeply curved over, lies below the beak of the 

 pedicle-valve, and an internally thickened pseudo-deltidium covering 

 over the triangular delthyrium is probably indicated by a median 

 triangular groove in this pseudo-area. 



About 40 low radiating rounded ribs ornament the surface of the 

 pedicle-valve, and a rather smaller number can be counted on the 

 opposite valve. 



Remarks. — The narrow cleft, groove or pit in the middle of the 

 cardinal plate and the pits in its anterior face vary somewhat in 

 depth ; and it is these features which seem to separate this form 



