Seidell ian Genus Corax. 453 



basal margin of the root. It is the inner surface of the tooth 

 which is exposed on the shib, and it is highly convex. The 

 anterior and posterior coronal margins are depressed and 

 flanged, and under magnification the edges are seen to be feebly 

 crenate. 



Dimensions. — Length of root, 5.5 mm. ; entire length of 

 crown, 6 mm. ; height of root, 2 mm. ; height of crown from 

 upjier limit of root, 1.25 mm. 



Remarks.- -The genus Corax is typically an Upper Cretaceous 

 fossil,' but one species, Corax antiquus, Deslong., has been 

 described from the Lower Oolite of Normandy.-' In its some- 

 what depressed form and inconspicuous serrated margins the 

 present example most nearly resembles C. affinis, Agassiz,^ from 

 the Upper Cretaceous (Danian and Upper Senonian) of Europe. 

 Agassiz's figures of C. appendiculatus* also closely resemble our 

 speci)uen, a form regarded by Smith Woodward as synonymous 

 either with C. prisfodontus, Ag.. or C. affinis, Ag.'' In C. affinis, 

 however, there is generally a broad posterior denticle near the 

 base of the coronal margin, which is entirely absent in the 

 Australian specimen. Upon these grounds it seems advisable 

 to keep the Australian form as a distinct species, also taking 

 into consideration the fact that it occurs in a rock of an older 

 division of the Cretaceous. It may therefore be referred to 

 under the name of Corax australis. 



Corax Australis, sp. nov. 

 Lower Cretaceous, Hamilt<jn River, Queensland. 



1 See Smith Woodward, Catalogue Foss Fishes (Brit. Mus.), 1889, pp. 422-429. 



2 Deslongrchamps, Le Jura Norniand, Mon. vi., 1877, p. 4, pi. i., figs. 4, 5. 



3 Agassiz, Poiss. Foss., vol. iii., 1843, p. 227, pi. xxvia, figs. 21-34. Smith Woodward, 

 op. cit., p. 427. Idem, Proc. Geol. Assoc, vol. xiii., 1895, p. 199, pi. vi., figs. 19-22. 



4 Agassiz, op. cit., pi. xxvia, figs. 16-20. 



5 Smith Woodward, op. cit., p 423 (footnote). 



