Neiv Fossils frovi the Bokkeveld Beds. 389 



more pointed, the beaks are rather lower and less swollen ; and the 

 clavicular ridge is rather shorter and decidedly stouter and straighter 

 than in the typical N. hranneri. The specimens which I have for 

 examination are all in the condition of internal casts, as are Ulrich's 

 figured specimens of N. beneckei. Fi'om the latter ours seem to 

 differ only by the slightly shorter anterior end of the shell, and by 

 the clavicular ridge being vertical or even a little curved forwards as 

 in N. africanus, in which, however, this feature is much more pro- 

 nounced and the shell is more elongate. Imperfect internal casts 

 of the Bokkeveld form referred to N. hranneri are often difficult to 

 distinguish from this variety of N. beneckei. 



The dimensions of the best preserved example are as follows : 

 Length 45 mm. ; height 31 mm. ; thickness 20 mm. 



Locality. — Zwartberg Pass. 



NUCULITES BEANNEEI Clarke, var. nov. obtusiis. 



There are some specimens from the Bokkeveld Beds (Nos. 796, 797, 

 locality unknown) which must be considered identical with N. bran- 

 neri Clarke ; but the majority of the specimens from Zwartberg Pass 

 and Gamka Poort (including the one figured by me as N. hranneri in 

 Ann. S. Afr. Mus., vol. iv., pt. vi., No. 11, p. 257, pi. xxxi., figs. 8, 8a) 

 have rather broader, more obtuse and subtruncate posterior ends, 

 with a less obliquely sloping dorsal margin, and are altogether of an 

 oblong rather than a subelliptical shape ; the clavicular ridge is also 

 stouter. It seems undesirable to separate these forms specifically 

 from N. hranneri, which they otherwise closely resemble, and they 

 may be regarded as a variety under the name obtusus. 



NUCULITES MAETIALIS Reed. 



(PI. XLVII., fig. 10.) 



One internal cast of the species described by the author as N. mar- 

 tialisr by showing both valves in apposition enables me to add a few 

 more particulars to the description of its characters. The beaks are 

 subcentral, being more than one-third the length of the shell distant 

 from the anterior end. The posterior margin is not " obliquely trun- 

 cate at the upper angle," but is regularly rounded, the whole shell 

 being subcircular or, rather, broadly elliptical in shape ; the height is 

 26 mm. and the length 31 mm. The hinge-line is short and arcuate ; 



* Reed, Ann. S. Afr. Mus., vol. iv., pt. (5, No. 11, p. 260, pi. xxxii., fig. 2. 



