104 PISCES. 



teeth were similarly serrated when perfect. One or two teeth from 

 the Red Crag Nodule-bed of Woodbridge and Fellxstow, contained 

 in the same Museum, are more elongated and approach the form of 

 C. angustidens, Ag. (Poiss. Foss., Vol. III., pi. 28, f. 20). Garcha- 

 rodon megalodon has been recorded from the Nodtde-bed below the 

 Coralline Crag at Sutton by Prof Prestwich (Quart. .Toum. Geol. 

 Soc, Vol. XXVIL, p. 118. and 132, 1871) but most of the specimens 

 have been found in the Nodule-bed below the Red Crag, at various 

 localities throughout Suffolk, and examples are to be seen in all 

 collections from this deposit. The species has been noticed from 

 the Belgian Pliocene by Le Hon (Prelim. Mem. Poiss. Tert. 

 Belg., p. 7, 1871) ; from the same horizon at Montpellier and in 

 Italy by Gervais (Zool. Pal. Fr. ed. 2, p. 520, pi. 74, 1859) and 

 E. Lawley (Studi Comp. Pesci. p. 35, 1881). Its occurrence in 

 Miocene strata at Malta and in North America has already been 

 alluded to ; and if certain of the North American phosphatic 

 deposits are correctly referred to the Eocene, then the species 

 must have existed at that period also. 



Large teeth similar to these fossils were dredged by the officers 

 of the " Challenger " expedition from the depths of the Pacific, in 

 a condition leading to the supposition that the species was living 

 at a comparatively recent period. 



CaECHARODON EoNUELETI, MULLEE & BENLE. 



[Great Blue Shark.) 

 Plate IX., Figs. 4a, b. 



To this living species are referred the shark's teeth from the 

 Suffolk Cragj which are smaller and proportionately more elonga- 

 ted than those of C. megalodon, they have strongly serrated edges 

 when unworn, and are sometimes longitudinally grooved, the 

 largest of them being about one inch and a half in length. Teeth 

 of this character were described by Agassiz (Poiss. Foss., Vol. III., 

 p. 254, pi. 30a, figs. 3-7) and named C. middens, E.. Lawley has 

 described (Studi. Comp. Pesci, Carcharodon, &c., p. l7, 1881) 

 a number of teeth from the Italian Pliocenes which he demon- 

 strated to be the same as the C. sulcidens of Agassiz, but which he 

 named C. etruscus, and it is not easy to understand why the new 

 name was given. Lawley also noticed the close agreement between 

 his Italian Pliocene specimens and the recent C. Rondeleti, but 

 hesitated to refer them to the living form. I see no reason for 

 thinking that C. sulcidens, and C. etruscus, are specifically distinct 

 from C. Rondeleti, and have for some time regarded them as the 

 same species ; and this view is taken by Mr. A. Smith Woodward 

 (Oat. Foss. Fishes, B. M., Part i, p. 420, 1889). 



Teeth of Carcharodon Rondeleti are to be seen in most collec- 

 tions of English Crag fossils, but comparatively few show the 

 serrated edge. The British Museum has a well preserved 



