ISURUS NASUS. 35 



Squalus pennanti Walbaum, 1792, Artedi, p. 517. 



LeSquale long-nez Lac^p^de, 1798, Poissons, 1, p. 216, pi. 2, f. 3. 



Squalus monensis Shaw, 1804, Zool., 5, pt. 2, p. 350; Cuv., 1817, Reg. anim., 2, p. 127. 



Squalus selanonus Leach. 1814, Mem. Wern. soo., 2, p. 64, pi. 2, f. 2. 



Carcharinus cornuhicus Blainv., 1816, Bull. Soo. philom., p. 121. 



Lamna cornubica Cuv., 1817, Reg. anim., 2, p. 127; Fleming, 1828, Brit, anim., p. ICS; Parxell, 1838, 

 Mem. Wern. soc, 7, p. 413; Muller & Henle, 1841, Plagios., p. 67; Bonaparte, 1841, Icon. 

 Fauna Ital., Pesci; Agass., 1843, Rech. poiss. foss., 3, p. 287, pi. G, f. 3; Schlegel, 1850, Jap. 

 Pisces, p. 304; Thompson, 1856, Nat. hist. Ireland, 4, p. 251; Kroyer, 1853, Danm. fiske, 3, 

 p. 852; Nilsson, 1855, Fisk. Skand., 4, p. 718; Dum^ril, 1865, Elasm., p. 405; Bocage & Capello, 

 1866, Plagios., p. 12; Gunther, 1870, Cat. fishes Brit, mus., 8, p. 389; Gerv. & Boul., 1876, 

 Poiss. Fr., 3, p. 180, pi. 168; Moreau, 1881, Poiss, France, 1, p. 296; Doderlein, 1881, Man. 

 ittiol. Medit., 2, p. 60; Day, 1884, Brit, fishes, 2, p. 297, pi. 156; Jensen, 1907, Dan. fiske, p. 296, 

 pi. 27, f. 2. 



Selanonius walkeri Fleming, 1828, Brit anim., p. 169. 



Squalus (Carcharinus) lamia Blain., 1830, Poiss. Fr., p. 88. 



Squalus (Carcharinus) cornuhicus Blain., 1830, Poiss. Fr., p. 96, pi. 14, f. 2. 



Isurus cornuhicus Gray, 1851, Chondropterj'^gii, p. 58. 



Body subfusiform, more massive anteriorly, slender, depressed, and with a 

 prominent keel at each side in the caudal peduncle, from the second dorsal 

 backward. Snout conical, longer than the mouth. Eye large, above the middle 

 of the mouth. Nostrils small, in the hindmost third of the snout. Mouth large, 

 nnich arched in front. Teeth with broad two-rooted base and slender lanceolate 

 cusp at the base of each side of which in the larger specimens there is a sharp 

 denticle, in if rows, third upper tooth at each side of the symphysis much smaller. 

 Outlines of the teeth as seen from the sides less waved than those of 7. punciatus 

 and other species; the teeth are more compressed and the edges are sharper. 

 Spiracles minute, nearly midway from the eye to the gill opening, or absent. 

 Gill openings large, width rather more than the length of the snout. Pectorals 

 subfalciform, pointed, outer margin about four times the length of the inner. 

 Origin of the first dorsal above the ends of the bases of the pectorals, length of 

 base about equal to height of fin, upper angle sharp, end far from the origins of 

 the ventrals, basal length nearly two fifths of the distance from the second dorsal. 

 Ventrals midway between the dorsals. Second dorsal very small, above the 

 anal, which latter it nearly equals in size. Vertebral axis of the caudal much 

 raised from the horizontal; a notch behind the subcaudal fin; subcaudal lobe 

 much produced; lateral keels prominent. Specimens are said to reach a length 

 of m.ore than ten feet. 



Greyish brown above; white below; young with white edges on some of the 

 fins. 



Jensen, 1907, pubhshes a fair representation of this species and of its denti- 

 tion. 



Reported from the British Isles, the Mediterranean, the Western Atlantic, 

 and from Japan. 



