304 F. R. Cowper Reed— The Bokkeveld Beds, S. Africa. 



rounded ; posterior end narrowed, truncated above, somewhat pointed 

 below. Cardinal margins of valves strongly thickened internally 

 as far forward as anterior adductor scars, with traces of 3-4 small 

 elongated pits in hinge -plate between and in front of beaks. 

 Adductor scars deeply impressed, oval, obliquely placed close below 

 beaks and on anterior lateral margin. Surface of shell marked with 

 a few strong oblique concentric growth-ridges. 



Dimensions : 



Length ... ... ... 25 mm. 



Height 15 ,, 



Thickness 14 ,, 



Locality. — Zwartberg Pass. 



Bemarks. — This shell appears to be identical with Nyussa arguto, 

 Hall,^ from the Hamilton Group of North Anierica. It is only in 

 the matter of the teeth (which probably are absent in our specimen 

 owing to its condition of preservation) that any diiference is 

 noticeable. Beushausen '^ identifies Go\dfnss' Sangiiinolaria dorsatd 

 from the Upper Calceola Beds and the Stringocephalus Limestone 

 with the American species. I am doubtful if Sharpe's SanguinoUtes (?) 

 cornujdtus^ from the Bokkeveld Beds is identical with our specimen, 

 Sharpe's type being merely the impression of one pair of valves. 



Sanguinolitks NIGER, sp. nov. (PI. XVI, Figs, 4, 4rt.) 



Two examples of another lamellibranch from the Zwartberg Pass 

 likewise consist of internal casts, one of which is nearly perfect, but 

 the other has the posterior end broken off. From the former 

 the following description is drawn up: — Shell oblong, upper and 

 lower margins nearly parallel ; posterior and anterior ends broadly 

 rounded, the former rather broader and more obtuse. Cardinal 

 margin behind beaks straight and horizontal ; inferior margin 

 indented with wide, shallow sinuation in middle, and curving up 

 more gradually in front than behind. Beaks subanterior, broad, 

 obtuse, low, scarcely rising above hinge-line, and directed forwards , 

 broad, undefined umbonal ridge runs down with decreasing strength 

 to posterior third of inferior margin, and has a weak, shallow 

 depression in front of it corresponding to marginal sinus. Valve.-< 

 moderately convex, most so on umbonal ridge, flattened and 

 compressed behind. Anterior adductor scars deep, oval, situated 

 just below beaks, close to anterior margin. Posterior adductor.s 

 indistinct. Cardinal and anterior margins thickened internally, 

 with elongated, lanceolate, ligamental area behind beaks, and one or 

 two elongated pits between beaks parallel to hinge-line. No teeth 

 present. 



Dimensions : 



Length 24-5 mm. 



Height 14-5 ,, 



Thickness 11-5 ,, 



' Hall: Pala'ont. N.Y., vol. v, pt. 1 (1883), pi. liii, tigs. 9-20. 

 * Beushansen: op. eit, , p. 31, pi. iii, tigs. 7-9. 

 2 Sharpe : op. cit., p. 212, pi. x.wii, tig. 8. 



