DISCUSSION OF SPECIES AND THEIK DISTRIBCTIOX. 21 



In the Mediterranean it is found at considerable dei)tlis. In .Tidy, 1S70, Prof. Gigljoli, 

 fishing- off Genoa with trawl lines, took ."iO individuals at depths of 400 to 500 fatliouis. 



PRISTIURUS ATLAXTICUS, Vaillant. (Figniv 20.) 

 rriiiliiinis (ithiiilicus, Vaim.an't, Exp. Scieut. Tniv. et Tal., 18S8, 39, pi. i, lij;. 1. 



A Pristitirm closely resembling P. meluMnmiix, Ilatiues(iue, but with its snout .some- 

 what more obtuse, its length from the extremity of the upper lip lieiug less than the dis- 

 tance between the labial commissures, while in tlie other species it is ecjual or greater. The 

 teeth ai-e somewhat stouter, less elongate, aud on tiieir sides are two dentiitulations instead 

 of the single one. They also appear to be more numerous— 31 on each side of the ui>per 

 jaw, in place of 28 in P. inelanosfoma.i. The cutaneous plates, although similar in character 

 and very like in form, have tlie margin proportionately narrower, and the middle rib more 

 narrow aud salient, the lateral teeth being less divergent. The branchial openings decrease 

 in width posteriorly, the last not more than half the height of the first; while in P. melanos- 

 tomtis it is at least three-fourths. 



The above description is a translation of the description by Vaillant, who, though 

 admitting that the differences taken singly are slight, considered tliat taken together they 

 impart to the animal a peculiar physiognomy, and that the com])arisou of a number of 

 specimens of tiie same size seemed to him to justify the establishment of a new species. 



Vaillant is of tlie opinion that possibly this form may be that described by Lowe from 

 Madeira, under the name PriMiurun melanostomm. 



A single female, 440 millimeters in length, was taken at a depth of 540 meters off ("ape 

 Spartel, from Station Vin of the French expedition. 



Family CETORHINID.^. 



CeAorhinidiv, Gill, Arr. Earn. Fish., 1872, 24. — .Jouuan ami Gilbkut, Bull, xvi, U. S. Nat. Muh., 1883, 30. 



Selachians with very wide gill openings in advance of pectorals, extending from the 

 back nearly to the middle line of the throat. Mouth moderate, the teeth small, numerous, con- 

 ical. Nictitating me:nbrane lacking. A small spiracle between eye aud first gill opening. 

 First dorsal large, above space between pectorals and veutrals; second dorsal and anal 

 small. Pectorals and ventrals large. Caudal flu lunate, a pit at its root, the upper lobe 

 considerably the larger. Sides of tail keeled. 



CETORHINUS, Blainville. 



Celorhinus, Blainville, Bull. Sop. Philom., 1811), 121. 

 Sdache, Cuvier, Rugue Aniuial, 1829, 390. 

 Polyprosopus, CoiiCH, Brit. Fi.sh.. i. 67-»i8, pi. xv. 



Eye <lestitute of membrana uictitans ; a small s[)iracle between the eye and the first 

 gill opening. Gill openings very large. Gills furnished with gill rakers for filtering i)ur- 

 poses, and consisting of an elastic apparatus of dentine. Teeth small, conical, without 

 dilated bases, and their sides smooth. First dorsal flu above the intersjiace between tiie 

 pectoral and ventral; second dorsal and anal small. Gaudal with a lower lobe and a pit at 

 its root; sides of the tail keeled. (T)ay.) 



CETORHINUS MAXIMUS, Gunner. (Figure 17.) 



Sqiialus maximus, Git.vner. Tiondhj. Selsk. Skrift.. 1705, iii. 33, pi. ii, iv, 14, pi. in.— LixxEis. S.vst. Nat., cd. 

 XII, 1766, 400. 



SeUiche maxima, CuviER. Rfegiie .\ninial, 1829, 391. — MiiLLER aud Henle, S. B. Plagiost., 71.— DrMKKU., 

 Elasm., 143.— GiiXTHER, Cat. Fish. Brit. Mus., viii, 394.— Bocaok aud Capello, Peix. Plagiost., II.— 

 Cetorhinus mnximus, Gooi>E aud Beax, Bull. E,ssex lust., XI, 29. — GKiLlon. Elfuco, 1883. 112.— JoiiiiAX 

 aud Gilbert, Bull, xvi, U. S. Nat. Mas., 31.— Day, Fisli. G. B. & Irelaud, u, 303, pi. cLViii, lig. 1. 



Squalus elephus, Le Sceur, Jouru. Acad. Nat. Sci. Phila., Ji, 343, tig. — De Kay, Zoiil. N. Y., Fish., 357, pi. 

 LXiii. fig. 208. 



