SYSTEMATIC CATALOGUE OF FISHES. 33 



very common at Cape Lookout from fall to April or May, when it departs, going 

 north as the fishermen believe. Many are caught there in the sink nets; and 

 they are often quite annoying and destructive, eating the fish in the nets and 

 chewing the twine. Commander Robert Piatt, U. S. N., states that the fish is at 

 times abundant off Cape Fear. Lawson's account of the fishes of North Caro- 

 lina contains this reference: 



The dog-fish are a small sort of the shark kind; ami are caught with hook ami line, fishing 

 for drums. They say, they are good meat; but we have so many other sorts of delicate fish, 

 that I shall hardly ever make tryal what they are. 



The eggs of the dog-fish are fertiUzed internally, and the young are about 1 

 foot long when born. From 4 to 12 fish are produced at one time. 



The abundance of this species, the facility with which it may be caught, and 

 the quality of its flesh warrant the belief that before long it will become the 

 object of a special fishery in North Carolina as in other states. Its non-utilization 

 in America up to this time depends on ignorance of its value and prejudice be- 

 cause of its name and relationship. 



Genus CARCHARHINUS Blainville. Flat-headed Sharks. 



This genus includes numerous species of medium and large sized sharks, of 

 voracious habits, found in all oceans. First dorsal fin placed anteriorly, nearer 

 to pectorals than to ventrals; no spiracles; all teeth in adults with serrate edges; 

 no groove from angles of mouth along jaws. Two species are known from North 

 Carolina, but several others undoubtedly occur, judging from their general range 

 and from incomplete descriptions of examples caught by anglers at Beaufort; 

 the recorded species (with others that may be looked for) are thus distinguished : 



t. Teeth in upper jaw broad, in lower jaw narrower. 



a. Pectoral fins very long and falcate, reaching beyond base of first dorsal; snout obtuse. 



obscurus. 

 aa. Pectoral fins shorter, not reaching to base of first dorsal. 



h. Length of snout anterior to mouth equal to width of mouth; fins not dark-tipped. 



milberti. 

 bb. Length of snout anterior to mouth equal .66 width of mouth; fins dark-tipped. 



platyodon. 

 ii. Teeth in both jaws narrow and constricted at base; length of snout equal to width of mouth; 

 pectoral fins falcate, extending beyond base of first dorsal; all fins black-tipped. 



limbatus. 



(Carcharhinus, jagged shark.) 



6. CARCHARHINUS OBSCURUS (LeSueur). 



Dusky Shark. 



Squalus obscurus LeSueur, Journal Academy Natural Sciences, Philadelphia, 1818, 223; New York. 

 Carcharhinus obscurus, Jordan & Evermann, 1896, 35. Linton, 1905, 339; Beaufort. 



Diagnosis. — -Head broad, flat; snout broad and rounded; teeth in upper jaw with a deep 

 notch on outer edge; second dorsal fin smaller than anal and considerably produced posteriorly; 

 pectorals long and falcate, their length 3 times breadth. Color: dusky blue above, white 

 below, {obscurus , dusky .) 



Along the east coast of the United States this shark is common and well 

 known. It reaches a length of 14 feet. Prof. Edwin Linton examined a number 

 taken at Beaufort, North Carolina, in July and August 1901 and 1902; the 



