Fishes. 1339 



ture of the skin rough, when felt against the grain. Colour blackish 

 brown on the back, and pectoral, dorsal, and caudal fins ; reddish 

 gray on the sides, white beneath. Lateral line pale, bent suddenly 

 down at the falcate portion of the tail. Conjunctiva of the eye bluish 

 white, the pupil large and black. A male ; the claspers small. It 

 was taken with a line, at the distance of about three miles from land ; 

 and seemed at the time to be feeding on pilchards. 



This species appears to have been unknown to the older naturalists, 

 since I have sought for it in vain in the works of Rondeletius, Ges- 

 ner, Ray, and Ruysch ; and it is not included in the tenth edition of 

 Linnaeus's System of Nature, though it is recognized in Turton's 

 translation of Gmelin's edition of the same work, under the name of 

 Squalus griseus. It is there represented as growing to the length of 

 2j feet ; but though this differs so little from the size of the Cornish 

 specimen, it is clear, from the additional teeth specified by Turton, 

 that the latter must be decidedly a younger individual. A specimen, 

 the first, and only other that has been taken in Britain, was caught 

 with a line, off Ventnor, in the Isle of Wight, in November of 

 last year ; which measured little less than 1 1 feet in length ; and 

 Risso (Ichthyologie de Nice) describes the fish in terms which can 

 signify nothing less than these full proportions. In the specimen re- 

 ferred to by Turton, there was only one row of teeth in the upper jaw, 

 but there were " many rows " in the lower ; and therefore we may 

 judge that it is about this period of its growth that the evolution of 

 dentition begins to show itself, and first in the lower jaw. I could 

 discern no more than one row in each jaw, in the specimen I have 

 described. Risso assigns three rows of triangular sharp-pointed teeth 

 to the upper jaw, and to the lower five ; and he adds, that the central 

 inferior teeth are sharp and conical ; by which I understand him to 

 say, that at the symphysis, between the lateral arrangements of 

 flat serrated teeth, he made out two or more of what I had supposed 

 to be a single bifid tooth. It is probable he is correct ; but they are 

 pressed closely together, and erect; so that in my specimen their 

 true nature could not have been ascertained without some degree of 

 mutilation. By Rafinesque, and subsequently by Muller and Henle, 

 this species has been constituted the type of a separate genus, under 

 the name of Hexanchus : one of the chief marks of which is, that 

 contrary to by far the largest number of the family of sharks, it is fur- 

 nished with six branchial orifices, and of which genus it is the only 

 known species. 



By Cuvier it is named Notidanus; and he classes in the same 



