62 ON THE GENUS SQJJALUS OF LINNE. 



shape of these parts : The generic characters 

 from the teeth, the position and form of the 

 mouth, and of the sacral fin. Two genera have 

 been formed from the Linnean genus, viz. Squa- 

 TINA and Squalus. To these I shall beg per- 

 mission to add two more, as in the following 

 Table : 



Familia Squalinid^e:. 



* Pinna anali 



1. Pinna caudalis lunata, - Squalus*. 



2. Pinna caudalis irregularis, - Gale us. 



• * Pinna anali nulld, 



3. Os ante oculos situm, - Squatina. 



4. Os pone oculos situm, - Acanthias. 



A more minute division, will, I have little 

 doubt, be hereafter found necessary ; but, in our 

 present state of knowledge, I should not consider 

 myself justified in proposing more genera. The 

 sexes of the genera Squalus and Galeus, may be 

 distinguished from the ventral fins being either 

 entire, divided, or furnished with a long process 

 beneath. 



* This genus may be subdivided froni the structure of the 

 teeth. 



