1868.] EOERTON LIASSrC FISHES. 490 



plates, and especially in the smaller size, and proportionately greater 

 number, of the apical digitations in the hindermost plate. 

 The dimensions as taken from the cast are as under: — 



inch. 



Length when entire, probably 7*4 



Greatest width (8th plate) 3-0 



Height (8th plate) 4-3 



Average thickness of plates on side ofl ^^^^ 



tooth J 



Ten plates are exposed by wear on the surface of the crown ; and 

 one, or it may be two more have been worn away in front, whilst a 

 small plate or talon has been broken off at the hinder end. The 

 disks of wear of the seven anterior plates are entire, the eighth 

 nearly so, whilst the ninth shows three oblong divisions, and the 

 tenth, as above said, exhibits traces of eleven or twelve, or more, 

 apical digitations just beginning to wear. The cast unfortunately 

 affords no clear indication of the sculpturing of the enamel-surface. 



The disks are very slightly arched transversely, and have no 

 tendency whatever to a median expansion. The sides are parallel 

 and the ends rounded, and not in the least retroflected. The enamel 

 is strongly crimped, and the crimping extends round the ends of the 

 disks. 



From the number of plates and the length of the tooth, I re- 

 gard ii, not as the penultimate, but as the antepenultimate upper left 

 molar. If met with in the recent condition, no one, I think, 

 would hesitate for a moment to refer it to K Indicus ; but when 

 regarded as a fossil, it is interesting and important to notice the 

 points in which it appears to differ from a corresponding tooth 

 of that species. These are : — (1) its considerable curvature ; (2) 

 its somewhat greater proportionate breadth, which in M 1 of E. In- 

 dicus, so far as I am aware, rarely, if ever, exceeds 2-5 or 2-6 inches ; 

 and (3) the greater thickness of the plates, which in the Indian 

 species averages about -48 inch, though it occasionally reaches -53 inch, 

 and in the lower molars very rarely as much as -6 inch. But these 

 differences do not appear to be of much importance, and there 

 seems to be every reason to believe that the Japanese fossil tooth 

 belonged to a form of E. Indicus, with teeth somewhat larger than 

 the average of the existing one. 



5. On the Charactees of some neiv Fossil Fish from the Lias of 

 Lyme Eegis. By Sir Philip Grey Egerton, Bart., M.P,, F.RS^, 

 F.G.S. 



Op all the noted localities for fossil remains in Great Britain not OBe 

 exceeds Lyme Regis for the number, variety, and interest of the 

 forms of ancient life which have been there discovered. Ever since the 

 earliest results of Miss Mary Anning's extraordinary success in col- 

 lecting remains of extinct animals were made known, scarcely a 



