SAND BAR SHARK
[Bigelow and Schroeder, 1948, p. 368.]
[Garman, 1913, pl. 3, figs. 4-6 (as Carcharinus platyodon).]
The brown shark differs from the dusky (only member of its genus that seems actually to have been taken within the Gulf) in the more forward position and larger size of its first dorsal fin, in its broader pectorals, and in its stouter trunk, heaviest forward (compare specimens in figure 14). Also, the anterior edge of its nostril is expanded as a low but definite triangular lobe, which is not the case in the dusky shark. Other characters (in combination) that mark it off from other members of this genus that might stray to the Gulf are: Mid-line of the back with a low ridge between the two dorsal fins; snout forward of a line connecting the front margins of the nostrils, considerably shorter than the distance between the nostrils; point of origin of second dorsal fin about over origin of anal fin, its free rear corner only a little longer than the height of the fin; apex of first dorsal fin angular; length of pectorals along anterior margin about as great as distance from tip of snout to level of second pair of gill openings; distance from rear tips of pelvic fins to origin of anal fin as long as base of anal fin, or longer, fifth gill openings longer than horizontal diameter of eye.
The teeth resemble closely those of the dusky shark (see figure 14).
Upper surface slate gray to brown; lower surface a paler tint of the same hue, or white; fins without any conspicuous black markings. When alive some of the dermal denticles are bright blue, at least on some specimens.
Sexual maturity is reached at a length of about 6 feet; maximum length about eight feet.
Southern Brazil, Louisiana, both coasts of Florida, and northward along the Atlantic coast of the United States to southern New England; also the tropical-subtropical belt of the eastern Atlantic, and the Mediterranean, or represented there by an extremely close relative.
Next to the sand shark, this is the most numerous of the larger sharks along the coasts of New Jersey and of New York. Some visit the vicinity of Woods Hole, though so few that the number taken there in most summers probably is not greater than six or seven. It has not been reported as yet from [page 44] within the limits of our Gulf, but is included here on the chance that a stray specimen may be taken, either on the outer coast of Cape Cod, on Nantucket Shoals, or on Georges Bank.
 Seven feet 10 inches is the greatest measured length that we have found recorded, with convincing evidence that the specimen actually was one of this species.
 If the eastern Atlantic-Mediterranean form is actually identical with the American, as seems to be the case, the specific name milberti of Muller and Henle, 1941, must be replaced by plumbeus proposed by Nardo in 1827 for the brown shark of the Adriatic.