DISCUSSION OF SPECIES AM) THEIR DISTRIBUTION. 15 



Dr. E. Percival Wright reixirted to Dr. tUiiitlier that he had seen the Portuguese fish- 

 ermen capturing this form at a depth of -100 or ."iOO fatlioms, witli hand lines 2AW) feet in 

 lengtli, and that they eamefrom tlie same di'pth witli iri/iiloninui. 



Centrosci/mniiK ohxriinis, \^aiilant (Voy. Travaillenr et TaHsman, 07, pi. ii, tig. 1'), is 

 doubtfully assigned to this genus, having close affinities also with Ccntroplioru.s. It was 

 taken oft' Soudan in I'OO fathoms and below. 



OXYNOTUS, Rafinesque. 



Oxynotus, Rafiuesqiie, Imlice, ISIO, i.'i. 



Cenlriiia, Covier, R^gne Aniuial, cil. 1, 1S17, ii, VAO. 



Sl)inacoid sharks, with elevated, trihedral trunk, and with a fold of skin along each 

 abdominal edge, and upon dorsal ridges between the fins; two dorsal fins, each with strong 

 spine; no anal. Mouth narrow, with deep lateral grooves. Lower teeth small, erect, trian- 

 gular, serrated; upper teeth slender, conical, grouped in front of jaw. Si)iracles wide, im- 

 mediately behind eye. Brauchial openings narrow. Xo nictitating membrane. 



Mediterranean and adjacent parts of Atlantic. 



OXYNOTUS CENTRIXA,(Liiiii.), Rafinksqik. (Figure 21.) 



Squalus ceiitrina, LlNN.BUS, Syst. Nat., ed. x, 17.")IS, 1. L',3:5 (from Mediterranean, liaseil on dcacriptious of 



Rondelet and Salviani). 

 Oxyiiotm centrina, Rafine^^QUi:. Iml. d' Itliologia Siriliana, ISIO, -t.), (JO. — (iii.i., Ann. Lye. Nat. Hist. \. V., 



VII, 405. 

 8<[imlu8 (Acanthorhinus) centrina, Hi.Aixvn.LK. l*'anue Franfaiso, 61, pi. xv, fig. 1. 



Centrina Snlriani, Risso. Hist. Nat. Eur. Merid., I'oiss., Ill, 13.'>. — Boxaparte, Icon. Fanu. Ital., Pesei, CXLI, 

 fig. 2.— Jlt'LLER and Hexi.e, S. B. Flag., 87.— BocACEand Capei.i.o, Peixes Plagiost.,32.— C'apello, Jorn. 

 ,\cad. Sci. Li.sboa, ii, 142, fig. of teeth. — Glxther, Cat. Fish. Brit. Mus., viii, 417. — Canestkixi, Fesci 

 d' Italia, 41.— Guichenot, Explor. Sei. d' Algeria, Poissons,126.— Day, Fi.sh. 6. B. & Ireland, ii, 318.— 

 GiGLiOLi, Elenco, 1883, 112. 



Centrina oxynotus, SwAixsox, Fishes, ii, 36.5. 



Centrina valpecula, Moreau, Poiss. de la France, i, 3.5.5, lig. til. 



The Centrina, called in Italy '• pesce-porco,''^ '•pttrrco,'' and •■ ponrr-marin" in Por- 

 tugal "j>f/.(¥/>(»>Y'0„" in France •• Iiiiinontin," is not unusual in the .McditeiTanean, and indi- 

 viduals have been taken at considerable depths ou the Setubal banks, by Portuguese natural- 

 ists, while Moreau records a straggler from the mouth of the Loire. In 1877 one was taken 

 in 26 fathoms oft' the coast of Cornwall, and in ])ast years the species a])pears to have strayed 

 as far north as Cornwall. 



Its claim to a position among the deep-.sea fishes is doubtful, but in the npinion of some 

 ichthyologists it is an iuhal)itant of .great ilejiths. 



It has never been found outside of the northwest Atlantic. 



Family SCYLLIORHINIDvE. 



Scylliidw, GCixther, Cat. Fish. Brit. Mas., viii, 1870, 400. — Gll.i., Fain. Fishes. 21. — Da v. Fishes Gt. Britain 

 & Ireland. II, 309. 



A family of sharks distiuguislicd l>y the position of their dorsal fins and their laying 

 eggs like those of the rays. The body is more elongated than in the sharks generally; the 

 scales developed as tine shagrt'en ; th(» head d('i>ressed and oval : f he nostrils with large flaps ; 

 the mouth inferior and arched ; the teetii small (several scries being in us(> at the same time), 

 compressed, and cuspidate ; branchial apertures five, the jiosteiior i>f whidi are abuxe tin! 

 pectorals; sjjiracles behind the eyes well developed; dorsal fins two, the anterior above or 

 behind the ventrals; anal fin present, variable in j)osition; caudal fin extended toward the 

 end of the tail, and with the lower lobe little produceil downward at its front margin : pec- 

 torals moderately developed and with rounded angles. 



