THE GRAY NOTIDANUS. 25 



PL A GIOSTOMI. NOT J DA NID&. 



SQUALL 



THE GRAY NOTIDANUS. 



Notidanus griseus, JONATHAN COUCH, Zool. for 1846, p. 1337, fig. 

 Hexanchus ,, MULL, und HENLE, Plagiost. p. 80. 



,, ,, GRAY, Cat. of Chondropt. Brit. Mus. p. 67. 



NOTIDANID.E. Family Characters. Sharks with a single dorsal and an 

 anal fin. Head flat. A small three -cornered nasal lappet. Upper fold at 

 the corner of the mouth very large, the under one small. Nictitating mem- 

 brane wanting. Tongue adherent. Spout-holes small, perpendicular. Six 

 or seven stigmata, diminishing successively in length, and all before the pec- 

 toral fin. A mesial tooth on the mandible : the next five or six under-teeth 

 form a saw, by the projection of their conical cusps ; the fore or inner 

 borders of the mandibular teeth are either smooth or wholly and finely 

 serrated ; and the distal teeth of that jaw are small and flat. In the upper 

 jaw the teeth are longer, more slender and more pointed, and their first 

 denticle is much longer than the rest : the outer border of the upper teeth 

 is thick, the inner one finely serrated towards its base : the foremost are 

 hook-shaped, on a broad base, and are clustered : the next in succession 

 have exteriorly one or two lateral denticles ; and towards the corner of the 

 mouth, the upper teeth resemble the under ones. Lateral line distinct. The 

 single dorsal stands behind the ventrals, and partly before, partly over the 

 anal. The caudal has small under lobes, with a notch towards the end, 

 which is obliquely or directly docked. No caudal pits. Intestinal valve 

 screw-shaped. 



NOTIDANUS. The only genus, subdivided by Hafiinesque into Hexanchus 

 and Heptanchus, according as the gill-openings are six or seven. 



IN the year 1846 a specimen of this fish, caught by a 

 fisherman at Polperro, was brought to Jonathan Couch, 

 Esq., who immediately recognised it as the grey sex- 

 branchial Notidanus, and he soon afterwards published 

 an account of it with a figure in the Zoologist (1337). 



