638 piinrEEDiNGs; of the national museum. 



much turned aside that the inner margin forms a cutting edge, which 

 is entire; spiracles moderate; no nictitating membrane; gill-openings 

 narrow; fins all very small, the ventrals between the dorsal lins; skin 

 uniformly covered with minute tubercles. Tail short, much bent 

 upward. Eggs large, soft, globular, without shell, dropped in the 

 ooze on the sea bottom. Species of the northern seas. 

 {som n ios us, sleepy . ) 



32. SOMNIOSUS MICROCEPHALUS Bloch and Schneider. 



iScjualus mirrocepJidluH Bloch and Sciineidei:, Syst. Ichtli., 1801, p. 135, northern 

 seas. 



Somniosus rnicrocephdhin JonDAN and Evermann, Fish Nortli and ^Middle Anier., 

 I, 1896, p. 57. 



S()mmos^^s brevipivmi Le Sueur, Jour. Ac. Nat. Rci. Phila., I, 1818, j). 122; Massa- 

 chxisetts. 



Sq/mnuK hrevipmna Storer, Fishes Mass., 1867, p. 2;]5. 



Squalus borealis Scoresby, Arct. Reg., I, 1820, p. 588, pi. xv, figs. 3 and 4; Arctic 

 Ocean. 



Litrnargus borenlisXiiiiiTUiEB., Cat. Fish., VIII, 1870, p. 426. 



Squalus glacicdiH Faber, Fische IsL, 1829, p. 23; Iceland. 



Sqnalus norve(jiannsBL,Ai^yiLi.v:, Fauna Fran(;aise, 1828, p. 61; Norway. 



Leiodo7i erkinafum^Vocm, Proc. Best. Sac. Nat. Hist., II, 1847, p. 174. Massa- 

 chusetts. J^; 



Body robust, rapidly tapering behind; greatest depth little more 

 than one-Hfth length; head somewhat less; mouth moderate, upper 

 jaw Avith 5 rows of small, sharp teeth, which are incurved, lancet- 

 shaped; lower jaw wntli 2 rows of broad, ((uadrangular teeth, divided 

 in their centers by perpendicular ridge, directed outward, about 26 

 teeth on each side; fins small, first dorsal about as large as ventrals, 

 largiu- than second dorsal; pectorals short, caudal short, l)luntish. 

 Ijcngth al)out 2.5 feet. Arctic seas south to Cape Cod, Oregon, France, 

 and Japan. 



A huge, clumsy shark, not rare northward; an enemy to the whales, 

 biting out Lirge masses of Hesh from their l)odies. 



The only Japanese record is that of a large example, seen by Jordan 

 and Snyder in the market of Tok3'o, in June, 1900. Specimens from 

 the Pacific have never been compared with those from the Atlantic, 

 and may Ix'long to different species. , 



(/tu/cpo?, small; KecbaXy^ head.) 



Family XV. PRISTIOPHORID^. 



SAW SHARKS. 



Body elongate, covered with fine, smoothish scales, forming shagreen; 

 snout produced in a long, flat blade, with sharp teeth on each side pro- 

 jecting at right angles, these of unecpial lengths; a pair of barbels on 



