184 Annals of the South African Museum. 



SPIEIFEE CEEES sp. nov. 

 (Plate XXII., figs. 6, 1 ; Plate XXII., fig. 1.) 



There is one type of Spirifer (Nos. 148, 144, 141, 145, 143) which 

 differs from any hitherto described, and appears referable to a new 

 species. The description of this form is as follows : — 



Shape transversely elliptical, biconvex ; cardinal angles rounded. 

 Pedicle valve with large prominent beak ; high and vertical hinge- 

 area ; large, deep, slightly angulated median sinus, with 4-6 large 

 slightly angulated prominent ribs on each side, straight and strong 

 near sinus but slightly curved and weaker near cardinal region. 

 Interpleural grooves as strong, deep and wide as ribs. 



Brachial valve with narrow hinge-area, median rounded prominent 

 fold increasing in width rather rapidly towards front, and 4-6 ribs 

 similar to those on pedicle valve on each side of it. 



Interior of pedicle valve shows pair of stout teeth and strong 

 muscular impressions. 



Fold of brachial valve shows trace of low median septum extend- 

 ing about two-thirds its length. 



Dimensions. — Length 45-60 mm. ; w^idth 80-100 mm. 



Ajfinities.—lA-ie&e large specimens differ from Sio. orbignyi in their 

 shape and in the smaller number and the angulation of the ribs. Sp. 

 hawkinsi '^'- appears to be too transverse and mucronate. The most 

 closely allied species seem to be Sj). (Delthyris) raricosta Conrad, f 

 and Sj). duodenarius Hall,j both of which occur in the Upper 

 Helderberg of North America. .S^j. macrothyris Hall,^ from the 

 same beds, has much less prominent ribs. 



The name Sp. ceres is proposed for this new form. 



Loccdities. — (Nos. 148, 144) South-east of Triangle, just below 2nd 

 Sandstone. (Nos. 141, 145) Slang Fontein, Ceres. (No. 143) North- 

 west of Lady Grey, near Worcester. 



SPIEIFEE sp. a. 



(Plate XXIIL, figs. 2, 3.) 



There is a form of Spirifer from Gamka Poort (No. 146) which is 

 closely allied to that which I have compared with Sp. pedroanus 



* Morris and Sharpe, Quart. Journ. Geol. Soc, vol. ii., 1846, p. '27G, pi. xi., 

 fig. 1. 



t Hall, Palteont. N.Y., vol. iv., 1807, p. 192, pi. xxvii., figs. 80-34. 

 : Ibid., p. 189, pi. xxvii., figs. 13-1(5; pi. xxviii. figs. 24-33. 

 § Ibid., p. 202, pi. XXX., figs. 10-20. 



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