DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 7 



the Atlantic. Somnio.sus and Echinorhinus live cLietiy in mid ocean, tlie former unciues- 

 tionably breeding at considerable deptli, tbougli it is not certain that it descends below the 

 hundredfatbom line. They are more abundant in the eastern Atlantic. 



SCYMNORHINUS, Bonaparte. 



Scymima, Cuviee, Ri-gne Animal, 1.S17, ii, 130.— MfLLEi: .md Henle, 8. ]!. Flag., 92.— GuXTnER, Caf. Fisb. 

 Brit. Mus., VIII, 426. 



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

 trals; no anal fin. Skin uniformly covered witli minute scales. Mouth transverse, a deep, 

 straight groove at each angle of the mouth. Xostrils 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. (GUnther.) 



SCYMNORHINUS LICllIA, Bonaparte. (Figures.) 



Squalus lichia, Bonnateure, Tabl. Eueyel. Ichtli., 1788, 12. 



Squale livlie, LACi':pf;i>K, Hist. Nat., i, 279, pi. x, fig. 3. 



Scj/iiiniis lichifi, Bonaparte, Fauna Italica, in, fasc xiv-xvi, 1836. — MCllek and Hesle, S. B. nag;.,92. — 



DiMtiinL. El.asm., 452. — Bocagh and Capei.lo, I'eix. Plagiost., 34. — tiCNTiiEi;, Cat. Fish. Brit. Mns., 



\-in, 42.5. — COLLETT, Bull. Sue. Z()<il. Frauce, 219. 



A Scyninns 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 jioiut. The first dorsal fin 

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



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. 



Somniomis, Le Sueur, Jour. Acad. Nat. Sci. Pliila., 1818, i, 222 (tyjie, Sumniasus hriripiinia, Le Suinir). — 



Gill, Proc. Acad. Nat. Sci. Phila., 1864, 264.— .Jordan, lor. cit., 14. 

 Lasmargiis, Muller and Heni.e, S. B. Plag., 1838, 93. [Preoccupied in Crustacea Iiy Kriiyer.] 

 Rhiiioscymnus (^.s'omniosHs part), Gill, lor. ril. 



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

 veutrals nearly opposite tlie second dorsal; mouth 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 lower jaw numerous, in about six rows, the 

 point so much turned aside that the inner margin forms a cutting edge; s|)ii'acles moderate; 

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



Two species are known; one, S. rostratu.s, recorded by Itisso and Cauestrini from the 

 Mediterranean, otf Nice and Genoa, where, according to Cauestrini, it lives at great depths 

 (Fauna d' Italia, Pesci, p. 43) ; the other, 8. microcrpludMs. fnuu the North Atlantic. 



SOMNIOSUS MICROCEPHALl'.S, (S.MiNKii.Ei!), (i'xH'i; and I!ea\. (Figure 8.) 



Squalti.^ carcharia.'i, Muller, Zoologicm Dauicie Prodrouuis, 1776, 38 (not Linnanis). 



Sqitalim microeephaluti, Schneider in Blocb, Syst. Ichtb, 1801. 1.35. 



Scymnus mirroocphdhis, Kroyer, Danmark's Fiske, ni, 18.53, 914, tig. — Collktt, Xovgcs Fislcf. 212.— Malm. 

 Fauna, G26. 



Somniosui microrrphal lis, Goode and Bean, Hull. Essex Inst., 1877, 31,— .Iouhax and (Jilbkut, Bull. x\i. U. S. 

 Nat. Mus,, 1883, 15. 



Sonmioxii.'i brrripinna, Le Sueur, .lourn. Acad. Xat. Si-i. I'hilu., i, 1818, 122.— Storer, Rep. Fish. Mass,, 189. 



Scijmnus hrri-ijHiiiia, Dk Kay, Zool, N. Y., Fish,, 361, pi. i.xi, lig, 202,— Storki:, Jleui. Am. Arad. Sci., Bos- 

 ton, IX, 1867, 235, pi, xxwiii, lig. 2. 



L(F.mai-i/iis hrri-ipiiiiiu, Di'-Mei:il. Ichlli., 4.56, pi, v, tigs, 3-4. — Moueai', Poiss. France, i, 3(il, lig, 63, 



SqiKihiH borealis, SCORKSBY, Arctic Regions, 1820. i, 5.38, pi. xv, ligs. 3-4.— Jenyx.s, Man. Brit. \ert. .Auiin., 

 1835, 506. 



