602 ORDER CHONDROPTERYGII. 



besides having air-holes, like the latter, they are dis- 

 tinguished by small and rounded teeth. 



Our seas produce two, confounded under the name 

 of Sq. mustelus \ L. 



Notidanus 2 , Cuv., 



Differ from galeus only in the absence of the first 

 dorsal. 



Squalus grisens, L., ; Sq. vacca, Schn., Augustin 

 Scilla, pi. xvii. 3 Ash-coloured above, whitish un- 

 derneath ; is very remarkable for its six wide branchial 

 apertures, and its teeth, triangular above, serrated 

 below. Its muzzle is depressed and rounded, like 

 that of the shark. 



Squalus cinerens, Gm., has as many as seven 

 branchial apertures very wide. Its teeth are toler- 

 ably like the lower ones of the preceding. Its muzzle 

 is pointed like that of comubicus 4 . 



These two species live in the Mediterranean 5 . 



1 The Emissole commune, Rondel. 375; Salv. 136. f. 2. cop. 

 Will. pi. B. 5. fig. 1, and erroneously cited under galeus. The 

 Emissole tachetce de blanc, Rond, 376. Bel. 71. cop. Aid. 393. 



2 NwncSavoc, (dry back) the Greek name of some squalus in 

 Athenseus. 



3 The teeth are well represented in this figure, but the fish very 

 badly. It is the genus Hexanchus, Rafinesque. 



4 It is the genus Heptranchias of M. Rafinesque, who errone- 

 ously denies it air-holes. 



' Messrs. Quoy and Gaymard have discovered in the Indian 

 Ocean, a species of this subgenus, entirely spotted with black, and 

 with seven air-holes. 



