314 PLAGIOSTOMATA. 



Genus II — Peistiurus, Bonaparte. 



Spiracles present. Nostrils inferior, large, and covered hy a valve. Snout 

 elongated. Teeth small and tricuspid. Two spineless dorsal fins, the first above 

 the hind end of the ventral, and the second above the hind end of the anal. One or 

 two rows of small flat spines arranged like a saw, and reclining on each side of the 

 upper edge of the caudal fin. 



1. Pristiurus melanostomus, Plate CLX, fig. 1. 



Squalus catulus. Gunner, Trondtli. Selsk. Ski-ift. ii, p. 249. Haae-gjdle, Strom, 

 Sondm. i, p. 283. Biidhaae, Ascan. Ic. iv, p. 5, t. xxiviii. Squalus prionurus, 

 Otto, Conspect. p. 5. 



Galeus melastomus, Eafin. Caratt. p. 13. 



Scijllium artedi, Risso, Eur. Merid. iii, p. 117. 



Squalus annulatus, Nilss. Prod. p. 114. 



Scylliorhinus delarochianus, Blainv. Fauna France, p. 74, pi. xviii, f. 2. 



Scylliorhinus melanostomus, Bonap. Fasc. vii ; Blainv. 1. c. p. 75, pi. xviii, f. 3. 



Fristiurus melanostomus, Bonap. Fauna Ital. Peso. ; Miiller and Henle, Plagios. 

 p. 15, pi. vii; Yarrell, Brit. Pishes (ed. 1) ii, p. 375, c. fig. (ed. 2) ii, p. 495, 

 (ed. 3) ii, p. 479 ; Thompson, Nat. Hist. Ireland, iv, p. 250 ; Dumeril, lob. i, 

 p. 325 ; Giinther, Catal. viii, p. 406 ; Collett, Gorges Fiske, p. 211 ; Malm, Fauna, 

 p. 623 ; Winther, Prod. Dan. Mar. p. 58 ; Canestrini, Fauna d'ltalia, Pesc. p. 50 ; 

 Giglioli, Catal. Pesc. Ital. p. 52 ; Moreau, Poiss. de la France, i, p. 285, f. 37. 



Pristidurus melanostomus, Bonap. Selach. tab. Anal. p. 11 ; Gray, Cat. Cart. 

 Fish. p. 32 ; White, Catal. p. 124. 



Scyllium annulatum, Nilss. Skand. Fauna, iv, p. 713. 



Scyllium. melanostomum, Jenyns, Manual, p. 497; Kroyer, Danm. Fisk. iii, 

 p. 832, c. fig. 



Fristiurus a.rtedi, Socage and Capello, Peix. Plagiost. p. 11. 



Blach-mouthed dog-fish. Couch, Fish. Brit. Isles, i, p. 18, pi. iii. 



Body elongated, snout depressed and more than half the length of the head, 

 ■which is flat on its dorsal surface. Eye — large. Spiracle placed just behind the 

 orbit. Mouth arched, or rather angular, and situated below the eyes. A small labial 

 fold round the angles of the mouth. Nostrils placed one-half nearer the mouth 

 than to the end of the snout. Gill-openings rather narrow, the last close over the 

 base of the pectoral fin. Teeth — in adults with one central and two lateral cusps 

 on each side. Fins — pectoral large, its length equalling about that of the head, but 

 not quite reaching the ventrals. Dorsal fins situated as described generically, the 

 anterior being slightly longer than the posterior : anal rather long, commencing 

 beneath the hind end of the first dorsal fin and terminating close to the caudal ; 

 this latter fin is well developed. Skin — rough, on the hand being passed from 

 behind forwards. Oolours — grayish-brown, becoming white on the sides and 

 beneath. Three rows of elongated black spots, having a light outer edge, pass 

 from the head along the sides, decreasing in number to one below the first dorsal 

 fin ; posterior to this are a few black blotches continued on to the caudal fin. 



Navies. — Black-mouthed, or eyed-dog-fish, terms referring to its colours. 



Means of capture. — Couch refers to two examples taken on hooks. 



Breeding. — Embryo case (as figured by Yarrell) destitute of tendrils. 



Habitat. — Seas of Europe, being common in the Mediterranean. West coast 

 of Scotland (Malcolm), one of two examples from there having been sent to 

 Tarrell. Off Banfi Edward observes that he is led to believe that it occasionally 

 occurs. One specimen, 25f inches long, was taken at Polperro, in Cornwall, 

 February 8th, 1834. 



Ireland. — Two specimens were obtained at Portrush, by Captain Portlock. 



The figure in plate clx is from a m.ale specimen, 18| inches in length, in the 

 National Collection from Madeira ; that of the egg-case is reduced from Yarrcll's 

 "British Fishes." 



