160 



Observations. — This species is with some difficulty to he dis- 

 tinguished from T. Seebachi, Schloenbach, from the Upper 

 Chalk of Hauover and Oligocene of Saxony, as it resembles it 

 in shape and ormentation. T. lenticularis differs, however, in 

 its arched hinge line, smaller and obtuse beak, and in the 

 limited development of the deltidium. 



Locality and Horizon. — Abundant in the glauconitic lime- 

 stones, north of Blanche Point, Aldinga Cliffs (Tate), and in 

 the yellow clays at Muloowurtie, Yorke's Peninsula (Tepper). 



Terebratulina triangularis, spec. nov. Plate viii., figs, la— Id. 



Shell triangularly ovate, a little longer than wide ; widest 

 at about the anterior — third ; front and sides rounded. Sur- 

 face ornamented with acute ribs, bifurcating ; interspaces 

 linear, fimbriated by imbricating lines of growth. Brachial 

 valve ftattish, slightly convex in the posterior part, with a faint 

 median depression towards the anterior, which produces a 

 faintly sinuous front margin. Peduncular valve regularly 

 convex. Beak prominent, acute ; hinge line narrow and 

 straight ; foramen longitudinal, large, and triangular. 



Dimensions. — Length, "35 inch ; breadth, - 3 inch ; depth, \15 

 inch. 



Locality and Horizon. — In the marls at Blanche Point, 

 Aldinga Cliffs, and in the chalky limestone, Bunda Cliffs, Great 

 Australian Bight. 



Terebratella Tepperi, spec. nov. Plate ix., figs. 8a — 8c. 



Hounded, moderately inflated, smooth, with concentric lines 

 of growth. Front margin plane. 



Brachial valve regularly and moderately convex to nearly 

 flat. Peduncular valve inflated and medially subangulated. 

 Beak broad, blunt, foramen large, deltidia small, separate. 



Loop imperfectly known ; but so much as remains in the 

 sole specimen which has been found to afford internal charac- 

 ters is clearly that of Terebratella. The medial septum is 

 remarkably short, being less than one-third the length of the 

 valve. 



This species belongs to the group typified by the recent JSTew 

 Zealand T. rubicunda, Solander, for which it cannot be mis- 

 taken. 



Dimensions. — Length, "85 ; breadth, "8 ; thickness, "45 of an 

 inch. 



Locality and Horizon. — " Muloowurtie Clays," near Ardros- 

 san, Yorke's Peninsula (five examples). Collected by Mr. 

 Tepper, to whom the species is dedicated. For an account of 

 the geology of the Muloowurtie Cliffs see his paper Trans, of 

 this Society, vol. ii., p. 74. 



