Jordan and Evermann. Fishes of North America. 57 



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 veiitrals between the dorsal fins ; 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 2, of the Northern Seas. (Latin somniosus, sleepy.) 



76. SOMNIOSUS MICBOCEPHALUS, (Blocb). 



(SLEEPER SHARK; NURSE.) 



Body robust, rapidly tapering behind ; greatest depth a little more than 

 k the length; head somewhat less; mouth moderate, upper jaw with 5 

 rows of small sharp teeth, which are incurved and lancet-shaped ; lower 

 jaw with 2 rows of broad, quadrangular teeth, divided in their centers 

 by a perpendicular ridge and directed outward, about 26 teeth on each 

 side; fins small, the first dorsal about as large as the ventrals and larger 

 than the second dorsal ; pectorals short, caudal short and bluntish. L. 

 about 25 feet. Arctic Seas south to Cape Cod, Oregon and France; a 

 huge clumsy shark, not rare northward. An enemy to the whales, biting 

 out large masses of flesh from their bodies. (/uiKpoc, small ; KeQuhij, head.) 



(Eu.) 



S/iunlns microcephalus, BLOCK & SCHNEIDER, Syst. Ichth., 135, 1801, Northern Seas. 

 Somnioswbrevipinna, LE SUEUR, Jour. Ac. Nat. Sci. Phila., i, 122, 1818, Massachusetts. 

 Scymnns brei-iphma, STORER, Fishes Mass., 235, 1867. 



Squalm borealis, SCORESBY, Arct. Reg., i, pi. 15, figs. 3 and 4, 1820, 538, Arctic. 

 Lxmargus borealis, GUNTHER, Cat., viu, 426, 1870. 

 Squalu* (jlacialis, FABEK, Fische Is!., 23, 1829, Iceland. 

 Squalus norwegianus, BLAINVILLE, Faun. Fran^aise, 61, 1828, Norway. 

 Leiodon echinatum, WOOD, Proc. Bost. Soc. Nat. Hist., n, 174, 1847. 



Family XX. ECHINORHINID^. 



(THE BRAMBLE SHARKS.) 

 Characters of the family included below in those of the single genus. 



a. First dorsal opposite ventrals, both fins very small. Teeth equal in the two jaws, very 

 oblique; skin with scattered round tubercles, like the thorns of brambles. 



ECHINORHINUS, 42. 



42. ECHINORHINUS, Blainville. 



FrJiitiorlthim, BLAINVILLE, Bull. Sci. Philom., 1816, 121. (spinosus). 

 ''niintli^ AGASSIZ, Poissons Fossiles, in, 183, 1836, (spinosus). 



Two very small dorsal fins without spine, the first opposite the ven- 

 trals ; no anal fin ; skin with scattered, large, round tubercles, surmounted 

 by prickles like those on a bramble, and, like them, leaving a scar when 

 detached. Mouth crescent-shaped; a labial fold around the angle of the 

 mouth and the end of the snout. Teeth equal in both jaws, very oblique, 

 the point being turned outward; several strong denticulations on each 

 side of the principal point; no nictitating membrane; spiracles small; 

 gill openings of moderate width. A single species of the East Atlantic, 

 straying to our coast, (t^of, a hedgehog, or sea urchin; fiivrj, shark.) 



