NO. 1324. F.LASMOBRANCHIATE FISHES— JORDAN AND FOWLER. 629 



b. Upper teeth simple, without smaller cusps at base, 

 c. Teeth alike in both jaws, subquadrate, each witli a nearly horizontal 



oblique cutting edge and a point directed outward ..Sfjii(thi.% 23. 



cc. Teeth unequal; upper teeth erect, with a single cusp; lower teeth more 

 or less oblique, iwints directed outward; dorsal spines not hidden. 

 d. Scales leaf-shaped, with a strong midrib, and sometimes a lateral rib on 

 each side, attached Ijy a peduncle; dorsal spines strong. 



LejiidoHilniis, 24. 

 del. Scales not leaf-shaped and not pedunclate at l)ase. 



(-. Scales not imbricate, each of three or four radiating spinule.s; dorsal 



spines strong Deania, 25. 



ee. Scales imbricate, each with three or more strong ri])S, eacli ending in 



a spine, the nuddle strongest; dorsal spines short Zameus, 26. 



bb. Upi^er teeth each witii 1 or 2 small cusps at Ijase on each side. 

 /. Teeth unequal, upper erect and tricuspid, lower oblique. 



Etmoplerus, 27. 

 Jj. Teetli e(iual, very small, and tricusj)i(l in Ijoth ]ii\VH . Co ilroscyllium, 28. 



23. SQUALUS Linnseus. 



Sijivdnti LiNN.EUS, Syst. Nat., X, 1758, p. 238 {acnnthiax, first species named; 



includes all sharks) . 

 Squalus Rafinesque, Caratteri di Alcuni Generi, 1810, p. 13 (*/^r^»//((V^saIld vynto; 



first restriction of th(^ name Squalus to species with spiracles and without 



anal fin). 

 AranihoHtinun BL\isyiLi,K, Journal de Physique, 1816, p. 263 (acanthias) . 

 AcanlJiia^ Risso, Hist. Nat. Eur. :\r('rid.. Ill, 1826, p. 131 {acnntldas). 

 Ent<jj-i/i-}driis Gill, Proc. Ac. Nat. Sci. Phila., 1862, p. 496 {uyato). 



Body rather slender. Mouth little arched, with a long-, straight, 

 deep, ol)li<(ue g'roove on each .side; no labial fold. Teeth rather small, 

 all simple, equal in the two jaws, their points so much turned aside 

 that the inner margin forms the cutting edge. Spiracles rather wide, 

 just behind the (\ye. Fins moderate!}" developed, the first dorsal larger 

 than the second, much in advance of the ventral tins, which are behind 

 the middle of the body, although in advance of the second dorsal. 

 Dorsal spines strong, not grooved. Tail scarcely bent upward. Small 

 sharks, abounding in the temperate seas. 



{sqi(ah(i<, shark, a word cognate to the Greek yaXt'f.) 



25. SQUALUS MITSUKURII Jordan and Snyder, new species. 



TSUN(JZA]\IP: (horn shark); TSUNOGE (HORNY I'TSH). 



Squalus mllsukura Jordan and Snyder, Check List, 1901, p. 129 ; Misaki, 

 name onlj-. 



Head al)out 41 in body; width of head 1\ in its length; snout 2f, 

 interorbital space 'l:, width of mouth 2^; tip of snout to mouth 2; &ye, 

 2| in interorbital space. 



Body moderately elongate, tail tapering moderately Ijchind. Head 

 broad, depressed, flattened above; snout pointed in profile, when viewed 

 from above angular, tip rather broadly rounded, and upper surface 

 flattened; eyes rather large, lateral, a little nearer tip of snout than 



