Jordan a?id Etoernt&nn. Pishes of North America. 39 



49. CARCHARHIXUS PLATYODON, (Poey). 



Body stout ; head very short, broad, depressed, and bluntly rounded ; 

 mouth twice as broad as long, its breadth about i more than length of 

 snout; upper teeth very broad, triangular, erect, coarsely serrate, not 

 notched ; lower teeth narrower, more finely serrate. First dorsal begin- 

 ning close behind pectoral, a little higher than long, not falcate, its base 

 2^ in interspace between dorsals; second dorsal very small, its base 5 

 in interspace ; caudal moderate, 2| in body ; anal a little longer than 

 second dorsal, and placed a little farther back ; pectorals rather small, 

 not falcate, 6 in total length, reaching a little past front of dorsal ; width 

 of pectoral nearly $ of its length. Slaty blue, white below; caudal 

 blackish, other fins with dark tips. L. 10 to 15 feet. Cuba to Texas; 

 abundant in the Gulf of Mexico; the specimen here described being from 

 Galveston. (7rAarvf, broad ; 6c5oi>f, tooth.) 



Squalus plalijodon, POEY, Memoriae, n, 331, 1861, Havana. 



Squalm obtusiis, POET, I. c., 337, Havana. 



Carcharias platyodon, JORDAN & GILBERT, Proc: U. S. Nat. Mus., 1882, 243; Synopsis, 872,1883. 



50. CABCHARHINUS FRONTO, (Jordan <fc Gilbert). 



(TlBURON.) 



Body short and stout; head very broad, depressed, broadly rounded 

 anteriorly, the front of snout parallel with cleft of mouth ; snout from 

 mouth i the distance between angles of mouth; and about equal to 

 distance from chin to the line connecting these angles ; interorbital 

 width twice length of snout to eyes. Teeth in both jaws narrowly trian- 

 gular, twice as high as broad, all nearly erect and scarcely notched on 

 outer margin. Free margins of fins concave ; insertion of first dorsal 

 nearer pectorals than ventrals ; length of base of first dorsal more than 

 its height, but less than iuterorbital width ; interspace between dorsals 

 2J times base of first, 3| times base of second ; tail 4 in body ; anal 

 smaller than second dorsal ; pectorals large, not acute, reaching a little 

 past front of dorsal. Slaty gray, the edges of fins brownish. L. 10 feet. 

 Pacific Coast of Mexico ; a large voracious shark remarkable for its broad 

 head, (fronto, having a wide forehead.) 



Carcharias fronto, JORDAN & GILBERT, Proc. U. S. Nat. Mus., 1882, 102, Mazatlan, Mexico. 

 (Type, No. 28167.) 



61. CARCHARHINUS NICARAGUENSIS, (Gill & Bransford). 



(TlGRONE.) 



Snout short, obtusely rounded ; distance from mouth to snout distance 

 between nostrils ; teeth ff ; upper teeth triangular, scarcely notched on 

 outer margin ; first dorsal commencing just behind axil of pectoral, its 

 height greater than length of its base ; second dorsal larger than anal, 

 its base 2| in that of first dorsal ; pectorals moderate, their length not 

 twice height of dorsal. L. 7 feet. Lake Nicaragua and its outlet, Rio 

 San Juan, abundant, confined so far as known to fresh waters, the only 

 strictly fresh water shark recorded. 



Eulamia nicaraguensis, GILL & BRANSFORD, Proc. Ac. Nat. Sci. Phila., 1877, 190, Lake Nica- 

 ragua, Nicaragua. 



