CARCHARIID^. 295 



Genus IV — Mustelus, Guvier. 



Pleuracromylon, Gill. 



Memhrana nictitans present. Small spiracles hehind the eyes. Mouth crescentic, 

 with long labial folds. Teeth small, numerous, similar in hath jaws, pavement-like, 

 obtuse, or with indistinct cusps. The first dorsal fin, spineless, situated somewhat 

 behind the origin of the pectoral, or above the interspace between that fin and the 

 ventral : the second nearly as large as the first : caudal without a distinct lower 

 lobe, and no pit at the commencement of the fin. 



Two species of ttis genus are common off our coasts and inhabit the European 

 seas, the M. vulgaris, in- which the young are developed without any placenta ; 

 and the M. loevis, the embryo of which possesses a placenta attached to the walls of 

 the uterus. This latter form hjis not yet been observed on our shores, although 

 common in some of the Baropean seas So long ago as the times of Aristotle and 

 Rondeletius the distinctive marks between thess two species were recognized ; 

 but subsequent to the time of Gesner they became overlooked, and the two 

 species were classed as one. At the commencement of this century Risso, and 

 subsequently others, ascertained the correctness of the opinion held by Aristotle. 

 The dorsal fin is placed somewhat more forward in M. vulgaris than it is in 

 M. loevis. 



1. Mustelus vulgaris, Plate CLV. 



Galeus asterias. Rondel, p. 376. Mustelus Icevis, Salv. p. 137, pi. xliv ; 

 Willugh. Hist. Pise. lib. iii, c. xiii, p. 60, pi. B5, f. 2; Jonston, De Pise. p. 26, 

 t. viii, f. 6 ; Ray, Synopsis Piso. p. 22. Oaleus stellatus, Gesner, 1598, p. 77, c. fig. 

 Squalus, Artedi, Gen. p. Q&, Synom. p. 93. Smooth-hound or shark. Pennant, Brit. 

 Zool. (Ed. 1766) iii, p. 151, pi. xvi (Ed. 1812), iii, p. 151. 



Squalus mustelus, Bonnaterre, Enc. loh. p. 7, pi. vii, f . 21 ; Lacep. i, p. 242 ; 

 Gmel. Linn. p. 1492 ; Bl. Schn. p. 128 ; Risso, Ich. Nice, p. 33 ; Turton, Brit. 

 Fauna, p. 112 ; Jenyns, Brit. Vert. p. 502 ; Johnston, Berwick. N.. F. Club, 

 1838, i, p. 176 ; Schlegel, Dieren Neder. p. 190, pi. xviii, f. 2. 



? Mustelus stellatus, Risso, Eur. Merid.' iii, p. 126. 



Galeorhinus hinnulus, Blainv. Fauna France, Poiss. p. 83, pi. xx, f. 2. 



Mustelus Icevis, Flem. Brit. An. p. 166; Templeton, Mag. N. Hist. 1837 (2) 

 i, p. 413; Tarrell, Brit. Fishes (ed. 1) ii, p. 393, c. fig. (ed. 2) ii, p. 512; 

 Swainson, Fishes, ii, p. 316 ; Pamell, "Worn. Mem. vii, p. 416 ; Thompson, N. H, 

 Ireland, iv, p. 252. 



Oaleus mustelus. Leach, Wern. Mem. ii, p. 63, pi. ii, f . 3. 



Mustelus pl'ebejiiis, Bonap. Faun. Ital. Pesc. iii, p. 43, t. f . 1 ; Giglioli, Catal. 

 Peso. Ital. p. 51 ; Canestrini, Faun. Ital. Pesc. p. 49. 



Mustelus vulgaris, (pt.) Miiller and Henle, Plagiost. p. 190, pi. xxvii, f. 1 ; 

 Miiller, Abh. Ak. Wiss. Berlin, 1840, p. 187, pi. iii, f . 2 ; Tarrell, Brit. Fishes 

 (ed. 3) ii, p. 495, c. fig. ; Kroyer, Danm. Fisk. iii, p. 930 ; White, Catal. p. 127; 

 Dumeril, loh. i, p. 400, pi. iii, f. 1-3 (teeth) ; Bocage and Oapello, Peix. Plagiost. 

 p. 16 ; Giinther, Catal. viii, p. 386 ; Moreau, Poiss. de la France, i, p. 311. 



Smooth-hound, Couch, Fish. Brit. Isles, i, p. 47, pi. x. 



In form this fish considerably resembles the tope, Oaleus vulgaris, but the snout 

 is not so much produced. Uyes — rather large : oval. Nostrils one-third of the 

 distance between the anterior extremity of the mouth and the snout. Spiracles 

 small ; gill-openings rather short, the last three being over the base of the 

 pectoral. Teeth — pavement-like, small and numerous. Fins — the first dorsal 



