22 CONTKIBUnONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
1S.-CARCHARI]VUS Blainville, 1816. 
Blue Sharhs. 
{CynovephaJus Klein, Gill.) 
(Carcharias Cuvier, not of Ralinesqne.) 
{Prionvdon Miiller & Henle.) 
{Phdamia Gill.) 
(Blainville 1816 : tyjte Canhariiius cuinmcrsoni Blainville. ) 
Large sharks, without si)iracles, with the teeth in both jaws strongly 
serrated in the a<lult, those in the upper jaw broad, those below nar- 
rower, straight, and claviforni 5 first dorsal large 5 second dorsal much 
smaller, usually not larger than the anal. Si)ecies numerous in the 
tropical seas. {%dp-/apo~^ rough ; /hvij, shark ; abbreviated from Garcha- 
rorltium.) 
* Body and head slender; dorsal fm inserted midway between pectorals and ven- 
trals {Carchannus). 
25. C. (L.) .Jew. & Gilb. — Great Blue Sharl\ 
“ Snout very long, nostrils rather nearer to the mouth than to the 
extremity of the snout ; no labial fold except a groove at the angle of 
the mouth ; teeth of the upper jaw oblique, scarcely constricted near the 
base ; lower teeth slender, triangular in young examples, lanceolate, with 
a broad base, in old ones. Pectoral tin long, falciform, extending to the 
dorsal, which is nearer the ventrals than the root of the pectorals.” {Giin- 
ther.) A large shark of the Avarm seas, occasionally taken on our 
coast. 
{Squalus ylaucus L. Syst. Nat. ; Carcharias ylaiwtis Gunther, viii, 364.) 
** Body and head stout ; dorsal tin placed close behind the root of the pectorals 
(JCttlamia Gill). 
26. C. obsciirsis (Le Sueur) J. & G. — Dusky Shark. 
Dark clear blue aboA^e, white below; head rather iiointed, flattened 
aboA^e and below ; tirst dorsal rather large ; second smaller than the 
anal, and considerably produced behind ; pectorals large, falciform. A 
large shark, reaching a length of nine or ten feet, inhabiting the North 
Atlantic and freiiueutly taken on our coast. 
(Squatus ohscurus Lc Sueur, .Touni. Ac. Nat. Sci. Phila. 1818, i, *223; Carcharias 
obscurus Giinther, viii, 366.) 
27. C. iiiilbcrti (Miiller & Henh*) Jor. & Gilb. — Blue Shark. 
This species is represented as having the snout shorter, blunter, and 
