145 



about the anterior third ; straight or slightly indented in front. 

 Yalves moderately convex, the brachial valve more depressed. 

 Surface marked with inequi distant concentric imbricate 

 lamellae of growth. Punctations of test not visible under a 

 pocket lens, except in thin sections when viewed by trans- 

 mitted light ; punctations minute, widely separated. Beak 

 small incurved and obliquely truncated by a small oval 

 foramen, separated from the umbo of the brachial valve by a 

 small triangular deeply impressed deltidial plate (elements 

 not distinguishable) . Interior without a medial septum ; of 

 the loop the part posterior to the crura only known. These 

 portions are longer, more slender, and less divergent than in 

 T. vitreoides. 



Dimensions. — Length, - 9 ; breadth, "75 ; thickness, 45 inch. 



Obs. — Young examples of this terebratulatid and Terebra- 

 tella furculifera closely resemble each other, but the latter is 

 at once known by its densely punctated shell structure and 

 foramen. Prom Terebratula vitreoides it differs especially in 

 its nearly flat brachial valve and pentagonal shape. 



Locality and Horizon. — In the glauconitic limestones, north 

 side of Blanche Point, Aldinga Bay. (Twelve examples). 



Terebratula (?) subcarnea, spec. nov. Plate ix., figs, la — lb. 



The interior of this species is not known, and the external 

 characters which belong to Waldheimia are not presented by it. 

 It so closely resembles T. carnea of the European Cretaceous 

 rocks, that it is only after very careful comparison with many 

 specimens of that species that differences are found to exist. 

 T. subcarnea has a larger, though small, foramen ; the brachial 

 valve is not so gibbous ; and its greatest breadth is nearly 

 medial. These characters partly serve to separate it from 

 T. cameoides* Gruppy, of the Antillian Miocene, to which must 

 be added that the front margin of our shell is either straight 

 or slightly depressed. 



Dimensions of a large specimen : — Length, If- inches nearly ; 

 breadth, 1^ inches ; thickness, 1 inch nearly. 



Locality and Horizon. — In the top-bed of chalk, Bunda Cliffs, 

 Great Australian Bight. (Por the geology of, see vol. ii. p. 

 104, of this Society's Transactions). 



Terebratula (?) bulbosa, spec. nov. Plate vii., figs. 5a— b. 



Shell ovate, longer than wide, rounded laterally and 

 attenuated towards the narrow, nearly straight, slightly 

 crenulated front. 



Brachial valve very convex, slightly depressed near the 



* Quart. Journ. Geol. Soc, London, vol. xxi., t. 19, fig. 3, p. 296, 1866 ; 

 and Davidson, Geol. Mag., 1874, t. 8, fig. 11, p. 158. 



