Mr. A. S. Woodward on Scapanorliynchus. 487 



of the sockets. The notches found in the species referred to 

 Saurodon show the earliest stages of this migration. 



The distinguished palaeo-ichthyologist, Mr. A. S. Wood- 

 ward, has recently kindly called my attention to a suggestion 

 made by Prof. E. D. Cope that the Saurocephalidse are 

 closely related to the Chirocentrida3, represented by the large 

 Chirocentrus dorab of the Chinese and Indian seas. I have 

 unfortunately had no opportunity to study a skeleton of 

 this fish; but, judging from the figures of the fish found 

 in Cuvier and Valenciennes, pi. 565, and in Day's c Fishes 

 of India,' pi. clxvi. fig. 3, its external appearance must be 

 much like that of the extinct Xiphactinus. Nevertheless, 

 we have no intimations that the teeth of Chirocentrus are 

 fixed to the jaws in any way different from those of ordinary 

 fishes. The fixation of the teeth in sockets is an unusual 

 thing among fishes; and this character alone, it appears to 

 me, is sufficient to remove Xiphactinus and its allies from 

 the ChirocentridaB, although not necessarily to a great 

 distance. I suspect that the Saurocephalidas will, when they 

 are better known, show distinctive characters in the vertebral 

 column also. 



LXVI. — Note on Scapanorliynchus, a Cretaceous Shark 

 apparently surviving in Japanese Seas. By A. Smith 

 Woodward, F.L.S. 



In his paper on the Cretaceous fishes from Mount Lebanon 

 published twelve years ago *, the late James W. Davis gave 

 an unsatisfactory description and figure of a remarkable i\q\v 

 shark under the preoccupied generic name of Rhinognathus. 

 He pointed out some of its principal characters, and, notwith- 

 standing the demonstrated presence of an anal tin, placed the 

 fish in the family Spinacidae. In 1889 f, after a detailed 

 study of the fine series of specimens in the British Museum, 

 the present writer published an amended definition of the 

 genus under the new name of Scapanorhynchus, placing it in 

 the family Lamnidse close to the well-known existing genus 

 Odontaspis. The dentition was shown to be identical with 

 that of the latter genus ; but other characters, such as the 

 slenderness of the fish, the peculiar elongation of the rostrum, 



* J. W. Davis, " On the Fossil Fishes of the Chalk of Mount Lebanon, 

 in Syria," Trans. Roy. Dublin Soc. [2] vol. iii. (1887;, p. 480, pi. xiv. 

 fig. 4. 



t A. S. Woodward, 'Catalogue of Fossil Fishes in the British 

 Museum,' part i. (1889), p. 351. 



