68 SYSTEM OF NATURE. 
Thus we have seven groups in each class indicated as 
parallels and equivalents, so that it would seem that this 
branch of the enquiry, concerning which my own informa¬ 
tion and knowledge are utterly at fault, is not likely to pre¬ 
sent any insuperable obstacle to those who combine a 
competent knowledge of ichthyology with a desire to cor¬ 
roborate these views of the System of Nature : it is therefore 
quite needless to occupy space in defending a division 
which must be almost unanimously admitted. 
