CAKCHARIID^. 
435 
47945. Two pieces of similar cartilage; Lower Chalk, Ilurham, 
Kent. Presented hj the Bon. Mohert Marslmm, 1877. 
49939. Smaller piece of similar cartilage ; Lower Chalk, Gljnde, 
Sussex. Caj>ron Coll. 
49940. Another specimen ; Chalk, Anindel, Sussex. Caprmi Coll. 
42981. Two elongated pieces of cartilage ; Maastricht Beds, Hol- 
Van Breda CoU. 
4188. “Fragment de Squelette ” (tesseras of calcified cartilage), 
figured by L. Agassiz, Poiss. Foss. vol. iii. pi. x.b. fig. 6; 
Chalk, Lewes. Bantell CoU. 
39062. Similar fossil figured by F. Dixon, Foss. Sussex, pi. xxxi. 
fig. 15 ; Chalk, Sussex. Bowerbardc Coll. 
42990. Smaller example ; Danian Beds, Maastricht, Holland. 
Van Breda CoU. 
Family CARCHARIID.E. 
Dorsal fins without spines, the first situated opposite to the space 
between the pectoral and pelvic fins. Eye with a nictitating mem- 
brane. Teeth hollow when completely formed, usually pointed. 
Genus CARCHARIAS, Cuvier. 
[Regne Animal, vol. ii. 1817, p. 125.] 
Syn. Careharinut, H. D. de Blainville, Bull. Soc. Philom. 1810, p. 121 
(in part). 
Snout produced forwards ; mouth crescent-shaped, the labial 
groove or fold being confined to, or not extending much beyond, 
the angle of the mouth. Spiracles absent. A pit at the root of 
the caudal fin, which has a distinct lower lobe. Teeth with a single 
sharp cusp, mostly compressed and triangular ; upper teeth usually 
difiering much from the lower teeth. 
According to the characters of the dentition, five subgenera are 
distinguished, as follow ; — 
A. Kone of the teeth serrated. 
i. Scdliodon, Muller & Henle (Syst. Beschreib. Plagiostom. 
1841, p. 27). 
Upper and lower teeth oblique, not swollen at the base, 
ii. Physodon, Muller «fe Henle {op. cit. p. 30). 
Lower teeth swollen at the base, points slender ; upper 
teeth compressed, triangular, oblique. 
2f2 
