308 PLAGIOSTOMATA. 



Family III— NOTIDANID^. 



Spiracles small and on the side of the neck. No membrana nictitans. 

 Gill-openings, six or seven. A single spineless dorsal fin, placed nearly- 

 opposite the anal. Lower caudal lobe present. No pit at the root of the 

 caudal fin. 



Genus I — Notidanus, Guvier. 



Hexanchus and Heptanchus, Rafin. : Mcmopterhinus, pt. Blain. : Notorhynchus, 

 Ay res. 



Spiracles small. Mouth crescentic, without any labial fold. Teeth in the upper 

 jaw consisting of one or tvjo aivl-shaped pairs, followed by six broader ones, which 

 have one strong and several smaller cusps. In the lower jaw six large comb-like ones 

 on either side, followed by some smaller lateral ones. 



Geographical distribution. — Seas of temperate and tropical regions. 



1. Notidanus griseus, Plate CLVIII, fig. 2. 



Piscis vacca, Scilla, De Corp. Marin. Lap. t. i, xxvii, xxviii. Le Griset, Bi'ouss. 

 Ac. Sc. 1780, p. 663. 



Squalus griseus, Grael. Linn. p. 1495 ; Lacep. i, p. 269 ; Bl. Schn. p. 129 ; 

 Risso, Ich. Nice, p. 37. 



Squalus vacca, Bl. Schn. p. 138. 



Monopterhinus griseus, Blainv. Faun. France, p. 77. 



Notidanus griseus, Cnv. Regne Anim. ; Bonap. Faun. Ital. Pesc. pi. cxxxvii, 

 f. 1 ; Couch, Zool. 1846, iv, p. 1337, c. fig. and Fish. Brit. Isles, i, p. 21, pi. iv ; 

 Yarrell, Brit. Fish. (ed. 3) ii, p. 515 ; Bocage and Capello, Peix. Plagios. p. 15 ; 

 Giinther, Catal. viii, p. 397 ; Canestrini, Faun. Ital. p. 42. 



Notidanus monge, Risso, Eur. Merid. iii, p. 129. 



Hexanchus griseus, Rafin. Caratt. p. 14 ; Muller and Henle, Plagios. p. 80 ; 

 Gray, Cat. Cart. Fish. p. 67, and Ann. and Mag. Nat. Hist. 1868 (4) i, p. 76 ; 

 White, Catal. p. 130; Dumeril, Ich. i, p. 431, pi. iv, f. 9-12 (teeth); Moreau, 

 Poiss. de la France, i, p. 336, c. fig. 55, 56 ; Giglioli, Catal. Pesc. Ital. p. 52. 



Snout rounded ; head flattened. Eyes — rather large. Nostrils nearer snout 

 than to the angle of the mouth. The spiracle small and intermediate between 

 the hind edge of the eye and the first gill-opening, or somewhat nearer to the 

 latter. Teeth — no single median pointed tooth in the upper jaw. In the 

 succeeding serrated teeth the first cusp the largest, as it is also in the lower 

 jaw, although not much larger than the succeeding ones. Central tooth in 

 lower jaw serrated at its edges. Gill-openings wide, the anterior one the highest. 

 Fins — dorsal situated behind the ventral, than which it is rather smaller, and 

 extending to slightly above the anal. Pectoral somewhat quadrangular, its corners 

 being rounded. Upper caudal lobe long and notched near its extremity. Skin 

 rough, the scales being small and leaf-shaped, with a central keel that extends 

 to the sharp end. Colours — of the Banff specimen olive-iron or reddish-gx-ay, 

 inclining to a leaden hue along the abdomen. It is a savage and voracious species. 



Names. — Six-gilled shark, brown or Mediterranean shark. Le Griset, French. 



Breeding. — Producing living young several times during the year. 



As food. — Rejected, and those who have tried of it find it a strong purgative. 



Habitat. — From the British coasts to the Mediterranean, where it is common. 

 A large one was captured at Banff in December, 1857, and placed in the Museum. 

 November, 1845, a female nearly 11 feet long was .secured off the Isle of Wight. 

 In May, 1873, one 2£ feet long was. taken by a bait three miles off shore at 

 Mevagissey (Dunn). February 19th, 1846, one 26 feet 5 inches in length 

 captured at Polperro, in Cornwall. Another 6 feet long was taken at the same 

 place, and is in the National Collection, it is the one figured. It is said to grow 

 to a large size. 



