136 LIVERPOOL BIOLOGICAL SOCIETY. 
perhaps not yet sufficiently known to justify the general 
adoption of any change in specific nomenclature; but 
there is no such excuse for delay in regard to the Salpe— 
the question can probably be settled as easily and con- 
veniently now as at any future time. In the case of a few 
species where the solitary and aggregated forms were 
found at the same time and their relationship was known 
when they were first described—as for example, Salpa 
affinis, Chamisso—only one specific name was given, and in 
these cases of course there is no need for any change; but 
in a number of the species, where the two generations 
have become well known under distinct names, I believe 
it will lead to least confusion and trouble with synonymy 
in the future if the double or compound names which I 
have explained above be systematically adopted. 
