156 



is, however, distinguishable from the Mannum fossil by its- 

 broad front and the tripartite division of the peduncular 

 valve. W. Taylori, TV. Corioensis, and W. sufflata, which are of 

 about equal size, are among the largest species of the genus. 



Waldheimia Corioensis, McCoy. Plate ix., figs 4 and 7 ; plate x., fig. 4. 



Ref. — Palaeontology of Victoria, Decade v., tab. 43, figs. 1 — 3, 



1877. 



Shell sub-ovate, greatest width about the middle, margin of 

 .sides convex in the middle. Pedunculated valve very convex 

 or very obtusely carinated along the middle, sides flattened, 

 very slightly convex, becoming slightly concave near the 

 lateral margins ; in profile it is much arched near the large 

 incurved beak, becoming tangentially straight towards the 

 front, which is elevated at the margin into a deep sinus 

 (bisinuate when old). Brachial valve flattened in the 

 umbonal half, with lateral margins abruptly deflected at right 

 angles towards the other valve, becoming gradually depressed 

 in the middle towards the narrowed front ; in old specimens 

 the mesial depression is divided by a wide slight convexity. 



Eoramen moderate, deltidium tripartite, the narrow middle 

 portion convex ; beak ridges moderate, angulated. 



Surface smooth, with moderate lines of growth. Mesial 

 septum about one-half rhe length of the shell. Length, 2-§ 

 inches. (Abridged from the original diagnosis.) 



A few large terebratulids obtained at Mannum seem to agree 

 generally with the example of W. Corioensis, represented by 

 the woodcut on p. 11. The least imperfect of them is shown 

 by fig. 4, pi. x. 



A fragment of the umbonal half of a large brachial valve 

 shows some peculiarities of the rostral boss. The hinge plate 

 is broad and deeply concave, the cardinal process is deeply 

 tripartite , the central lobe erect, thick, and compressed, the 

 laterals are divaricate, lamellar, and confluent with the crura?. 

 (PI. ix., fig. 7.) 



A single specimen of another large terebratulid (fig. 4, pi. 

 ix.), though differing greatly in its wide and deep mesial 

 depression, is provisionally referred to this species. 



Locality and Horizon. — Lower Murravian, rare in raggy lime- 

 stones at Mannum (Tate). 



Miocene Tertiary, Corio Bay, Geelong ; Jan Juc (abundant), 

 more rare at Muddy Creek (McCoy). 



Dimensions of the specimen, fig. 4, pi. x : — Length, 2'65 

 inches ; breadth, 1*8 inch ; thickness, 1"6 inch. Of the variety, 

 fig. 4, p. ix) : — Length, 22 ; breadth, 2 • thickness, 1*2 inches. 



