SOMNIOSUS MICROCEPHALUS. 241 



Body little compressed, head depressed. Middle of the total length below 

 the anterior portion of the first dorsal. Middle of the trunk, without the caudal, 

 at the end of the pectorals. Tail from the vent less than one third of the total 

 length. Snout hardly longer than width of mouth, blunt, rounded at the end; 

 nostrils much nearer to the end than to the eyes. The length of the snout about 

 equal to half the distance from the bases of the pectorals to the origin of the 

 first dorsal, or to half that between the two dorsals, and to a little more than that 

 between the base of the second dorsal and the caudal. Eye small, diameter 

 nearly one fifth the length of the snout, or more than half the distance from the 

 spiracle. Teeth in u rows; upper more compressed and broader than those of 

 S. microcephalus; lower, compared with those of the same species, a trifle narrow 

 with slender elongate roots, Plate 15, fig. 2, 5. Gill openings rather narrow, 

 upper edges on a level with the pectorals. Pectorals small, angles rounded, fin 

 reaching little more than half way from the base to the origin of the dorsal. Base 

 of first dorsal above the mid length of the total, or one length of the snout behind 

 the mid length of the trunk, excluding the caudal fins. Second dorsal origin 

 above the ends of the bases of the ventrals. Ventrals larger than the dorsals, 

 length of bases two thirds of their distance from the caudal. Caudal about 

 one fifth of the total length, depth nearly two thirds of the caudal length, margins 

 convex, except behind the subcaudal, which latter is deep anteriorly and is 

 separated from the terminal by a shallow notch. 



Blackish brown. 



Total length of specimen described 76, snout to caudal 60, snout to ventrals 

 46, snout to dorsal 36, length of pectoral 8, and length of caudal 16 inches. 



Sagami Sea, Japan. Alan Owston. 



SOMNIOSUS MICROCEPHALUS. 



Plate 15, fig. 4-6. 



Haa-skierding Gunner, 1763, Trondj. sels. selskr., 2, p. 330, pi. 10, 11. 

 Squalus carcharias Muller, 1776, Zool. Dan. Prodr., p. 38. 

 Squalus microcephalus Schneider, 1801, Bloch Ichth., p. 135. 

 Squalus borealis Scoresby, 1820, Arctic reg., 1, p. 528, pi. 15, f. 3, 4. 

 Scymnus rostratus Risso, 1826, Hist, nat., 3, Poissons, p. 138, pi. 3, f. 7. 

 Scymnus borealis Fleming, 1828, Brit, anim., p. 166. 

 Scyynnus gunneri Thienemann, 1828, Lehrb., 3, p. 409. 

 Scymnus glacialis F. Faber, 1829, Fische Islands, p. 23. 

 Squalus norvegianus Blainv., 1830, Poiss. Fr., p. 66. 



Greenland shark Yarrell, 1836, Brit, fishes, 2, p. 403; Couch, 1867, Brit, fishes, 1, p. 57, pi. 13. 

 Squalus {Scymnus) gunneri Richardson, 1836, Fauna Bor. Amer., 3, p. 313. 



Scymnus {Laemargus) borealis Muller & Henle, 1841, Plagios., p. 93; Gaimard, 1851, Isl., Poiss., pi. 

 22; DuMERiL, 1865, Elasm., p. 455, pi. 5, f. 1, 2. 



