SHARKS AND RAYS OF BEAUFORT, NORTH CAROLINA. 



253 



rounded, posterior lobe acute-angled; second dorsal small, over anal, posterior lobe elongate, distal 

 margin straight; pectorals larger than first dorsal, inner angle reaching beyond vertical from origin of 

 first dorsal, distal margin slightly concave; ventrals truncate; anal slightly larger than second dorsal, 

 distal margin incised, posterior lobe acute; caudal long, 3.63 in total length; subcaudal lobe deep, 

 rounded, terminal lobe distinct, deep. This rare species, according to Jordan and Evermann, has 

 been recorded from New York, Virginia, and Cuba. 



Fig. 10. — Denticles. A prionodcn iwdon, 50.8 cm. long, ia Beaufort collections. 



Genus HYPOPRION MUller and Henle. 

 10. Hypoprion brevirostris Poey. Sand shark. 



Carckarhinus obscurus, Linton, 1905. p. 339 (in part); Smith. 1907. p. 33 (after Linton). 

 Hypoprion brevirostris, Raddiffe. 1913, p. 396; Coles. 1914. p. 90. 



Teeth. — Teeth in i2zM rows, suberect, subulate, narrow-cusped, broad-based, two-rooted; cusps 

 29-31 



of lateral teeth in upper jaw slightly inclined toward angles; teeth near angles with a distinct notch; 



cusps smooth, shoulders distinctly serrate; lower teeth slenderer, without serrations on cusps or 



shoulders, cusps more nearly erect; three rows of small teeth at symphysis of each jaw. Three rows 



of teeth at angles of mouth resembling the teeth of Scoliodon ternx-noves. 



Denticles. — The denticles are large, being about 0.4 to 0.62 mm. long by 0.4 to 0.6 mm. wide in a 

 shark 248.9 cm. in length, heavy, normally five-keeled (three to five), unequal, imbricated; median 

 keel very heavy, interspaces rather deeply concave; keels parallel; apical margin usually five-lobed 

 (three to five), median lobe strongest, with a deep incision on each side; basal margin rotmded; pedicel 

 reduced to a very short, heavy neck, resting on a large stellate basal plate. 



Three large males were caught with a shark hook baited with butterfly rays and toadfish floated out 

 from first jetty on Fivers Island so that the bait hung about 2 feet below surface, as follows: A specimen 

 (no. i) 228.6 cm. (7>^ feet) long, August 31, 1912; one (no. 2) 205.7 cm. (6)4 feet) long, September i, 

 19 12; and one (no. 3) 248.9 cm. (8V6 feet) long, August 12, 1913. In each case these were hooked during 

 the night. 



97867°— vol 34—16 17 



