DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 7 



the Atlantic. Somnio.sus and Echinorhinns live cbiefly in mid ocean, tLe former nnques- 

 tionablj' breeding at considerable depth, though it is not certain that it descends below the 

 hundred-fathom line. They are more abundant in the eastern Atlantic. 



SCYMNORHINUS, Bonaparte. 



Scymuiis, CuviER, Regiie Animal, 1817, ii, 130. — MCllek anil Henle, S. B. Plag., 92. — GCnther, Cat. Fish. 

 Biit. Mus., VIII, 42(5. 



Two short dorsal fins without spine, the first at a considerable distance from the veu- 

 trals; no anal tin. Skin uniformly covered with minute scales. Mouth transverse, a deep, 

 straight groove at each angle of the moutli, Nostrils at the extremity of the snout. Upper 

 teeth small, pointed; lower much larger, dilated, erect, triangular, not very numerous. No 

 membrana nictitans. Spiracles wide. Gill openings narrow. (Giinther.) 



SCYMNOEHINUS LICHIA, Bo.naparte. (Figure 3.) 



Squalm lichia, Bonnatekre, Tiibl. Encycl. Ii^hth., 1788, 12. 



Sqiiale liche, LACKPfenE, Hist. Nat., 1, 279, pi. x. fig. 3. 



Scymnus Jichia, Bonapakte, Fauna Italica, in, fasc. xiv-xvi, 1836. — MCli-er and Henle, S. B. riag.,92.— 



DiM^KiL, Elasm., 452. — Boc.^^GE and Capello, I'eis. Plagiost., 34. — OCxthki!. Cat. Fish. Brit. ilus.. 



VIII, 425. — Collp;tt, Bull. Sue. ZodI. France, 219. 



A Seym mis with seventeen or nineteen erect teeth in the lower jaw, with the edges ser- 

 rated. Scales minute, with a median keel, and terminating in a point. The first dorsal flu 

 is nearer to the root of the pectorals than to that of the ventrals. 



This is the only species of the genus. It occurs in the western parts of the Mediterra- 

 nean and about Madeira. It should be sought for by the fishermen on the Halibut banks. 



SOMNIOSUS, Le Sueur. 



SomniOKiis, Le Sueur, Jour. Acad. Nat. Sci. Pliila., 1818, i, 222 (ty]ie, SomnioxiiH hrcriphimi. l.e Sueur). — 



Gill, Piop. Acad. Nat. Sci. I'hila., 1864, 264.— .Jordan, loc. oil., 14. 

 Liemai-gns, MCllei: and Hi.nle, S. B. Plag., 1838, 93. [Preoccupied in Crustacea Uy Kriiyer.] 

 Uhinoscymnus (=.'?0Hin/»8"s part). Gill, loc. cit. 



Scymnoid sharks with body elongate and two spineless dorsals; fins all very small, the 

 ventrals nearly opposite the second dorsal ; moutli transverse, with deep groove backward 

 from its angle; nostrils near the extremity of the snout; Jaws feeble; teeth in upper Jaw 

 in several rows, small, narrow, conical; teeth in h)wer Jaw numerous, in about six rows, the 

 point so much turned aside tliat the inner margin forms a cutting edge; spiracles moderate; 

 no nictitating membrane; gill openings narrow; skin uniformly covered with fine tubercles. 



Two species are knowu; one, S. rostriitus, recorded by Risso and Canestrini from the 

 Mediterranean, off Nice and Genoa, where, according to Canestrini, it lives at great depths 

 (Fauna d' Italia, Pcsci, p. 43); the other, S. mivrocephalus, from the North Atlantic. 



SOMXIOSFS M1CROCEPHAU:S,(Sciini:ii>hh), GcHini: and Bean. (FigureS.) 



Squaliin carchariiix, Muller, Zoologicic Dauic;b Prodroiuus, 1776. 38 (not Linincus). 



SqitahcH microceiihahi!!, Schneider in Blocb, Syst. Ichth, 1801. 135. 



Scjimnus minocephtiliii, Kroykr, Daninark's Fiske, in, 18.53, 914, tig. — Collktt, Xoigcs Fiske, 212. — M.VLM. 

 Fauna, 626. 



Somnionns microeephalds, GooDE and Bean, Bull. Essex lust., 1877, 31. — .Iouda.n and Gilbeut, Bull.xvi, U. S. 

 Nat. Mus., 1883, In. 



SomnioKitK breri])iiina, Lk Sui'.ur, .Journ. Aca<l. Nat. Si-i. Phila.. i, 1818, 122. — Storer, Rep. Fish. Mass., 189. 



Sciimniis hrc'vipiiDia, Dk Kay, Zo(51. N. Y., Fish., 361, \i\. lxi, fig. 202. — Storer, Mem. .\m. Acad. Sci., Bos- 

 ton, IX, 1867, 235, pi. xxxviii, fig. 2. 



Lwmarniis briviphnid, Du.meuil, Ichth., 4.51), pi. \-, ligs. 3-4. — Moueau, I'oiss. France, I, 361, tig. 63. 



Sqiiahi.'< borealin, .ScoRESBY, Arctic Regions, 1820, i. .5:i8, pi. xv, figs. 3-4. — .Iexyxs, .Man. Brit. Vert. Anim., 

 1835, 506. 



