HISTORY OF THE FISHES OF MASSACHUSETTS. 



219 



a specimen taken in Long Island Sound, on the north shore of Brook haven. It 

 common in our waters. 



Massachusetts, Storer. Connecticut, Ayres. 



Carcharias obscurus, Storer. 



The Dusky Shark 



(Plate XXXVI. Fig. 2.) 



Squalus obscurus, Dusky Shark, Lesueur, Acad. Nat. Science 1, p. 223, pi. 9. 



Storer, Report, p. 184. 



a 



Carcharias obscurus \ " 



Ci 



(C 



it 



f« 



a 



Bost. Journ. Nat. Hist., n. p. 558. 

 Dekay, Report, p. 350, pi. 61, fig. 201. 

 Storer, Synopsis. 



Color. Above, a dark yet vivid blue, somewhat banded by lateral lines, yet gradually 



passing into the pure white of 



abdomen; this tinge of the back extends low upon 



the sides. Upper part and sides of head, as well as caudal and most of dorsal fins, of e 

 delicate steel color with coppery reflections. Pectorals above, very dark green ; beneath 



Pupil? 



dull white. Posterior border of dorsals covered with a black mucous slime 



dark brown, irides golden 



Descript 



Body tapering gently posteriorly 



o 



depth, midway b 



the pectorals and the first dorsal fin, equal to a little more than one seventh the entire 

 length. Head elongated, sharp, flattened above and below. Snout throughout studded 

 with mucous pores arranged in lines or at random, some of which are very large. The 

 length of the head is < 



qual to little more 



- 



greatest depth is about 



third 



length, and 



qual 



of the bodv 



greatest 



w 



lth 



Ey 



6 



their longest diameter, the longitudinal, equals about one quarter the dis- 



between them. Nostrils situated on the outer edge of the lower surfa 



of 



head, not quite midway between the eyes and end of the snout, nearer the eye, doul 



the 



and 



downwards and 



ds; the posterior. 



nearly circular. Mouth not very large ; the outer edge of the upper jaw just beneath 

 the centre of the eye j its outer angle about one third the distance between the eye and 

 pectorals. Both jaws armed with short, triangular, and serrated teeth j those in the 

 upper jaw curved backwards ; in each jaw a single row behind, a double row in front. 

 Branchial apertures, five, comparatively small ; the posterior two just above the anterior 

 margin of the pectorals. 



