152 



Specimens collected from a marly band in Blanche Point 

 Cliff, Aldinga, exhibit radial flashes of colour. 



Dimensions. — Length, l'l ; breadth, - 9 ; thickness, '45 inch. 



Observations. — This species has some external resemblance to 

 Terebratitla Aldinyce, but differs in its rounded outline, in the 

 shape of its beak, and in its smaller foramen. It varies in the 

 degree of convexity of the valves, the more depressed forms re- 

 calling the inflated variety of the Liassic W. mmismalis, but 

 without its circular shape and minute foramen. It also bears 

 a strikiug likeness to Terebratula Hilarionis, Meneghini, from 

 the Eocene of Italy (vide Geol. Mag., 1870, p. 401, t. 17, f. 4, 5). 



Locality and Horizon. — Glauconitic limestones, Aldinga Bay ; 

 upper part of chalk rock, Bunda Cliffs, Great Australian Bight 

 (R. T.) ; Upper Eocene, New Zealand, the identification 

 based on specimens kindly forwarded by Dr. Hector. 



Waldheimia grandis, T. Woods. PI. xi., figs. 3 and 4. 



Ref— Trans. Adelaide Phil. Soc, 1865, t. 2, fig. 1. 



Syn. — "W. Gainbierensis, Etheridge, jun., Annals and Mag. 

 Nat. Hist., vol. 17, p. 19, t. 2, fig. 4 (1876). 



" Shell smooth, very thick, elongated, convex ; ventral valve 

 subcarinated, margin with two obscure plaits in the older 

 specimens ; beak short, obtuse, obliquely truncated, with a 

 large circular cup-shaped thickened foramen. Loop two-thirds 

 as long as the dorsal valve ; lamellse slender, straight, reflec- 

 tion unknown ; septum, as long as loop, gradually tapering ; 

 crura? thick, semicircular. Length 22 inches, breadth l - 4 

 • inches. It is a very variable shell." — T. "Woods. 



Etheridge' s figure represents the adult form of the species, 

 though its dimensions are below the average of fully developed 

 examples. The Rev. J. E. Tenison "Woods' illustrations of this 

 species are of a large but somewhat immature specimen, in 

 which the biplicated front, characteristically shown in Mr. 

 Etheridge's drawings, is only commencing to be formed. There 

 cannot be a doubt of the relationship existing between the 

 two shells ; they, moreover, came from the same locality. 



Etheridge referred his species to Waldheimia, solely because 

 a mesial septum was indicated by an impressed line on the 

 brachial valve. Tenison "Woods, however, proceeds with more 

 caution, and states that he is not certain if it be probably 

 referred to that genus, though the unreflected portion of the 

 loop was alone unknown to him. Having been fortunate in 

 obtaining a full display of the interior, uncertainty as to the 

 generic position of the species is entirely removed. The loop 

 presents no character worthy of note. 



Mr. T. Davidson says : — " It approaches to the Italian 



