ig 
THE SPECIFIC NOMENCLATURE OF SALPA. 13: 
many of the Hydroid Zoophytes (Hydromedusse) when 
their life-histories are more accurately known and their 
sexual and asexual forms have been co-related. The fixed 
Hydroid Zoophyte in many cases gives rise asexually by 
budding to the free-swimming medusoid gonophore, which 
in turn produces reproductive elements developing into 
the fixed Zoophyte. This life-history is comparable with 
that of Salpa. The’ solitary asexual Salpa corresponds to 
the fixed Zoophyte, and the aggregated sexual Salpa to 
the free-swimming medusoid gonophore. In the case of 
these Hydromedusee, as in that of the species of Salpa, 
the asexual and the sexual generations were in most cases 
discovered and named independently of one another, and 
were usually even given distinct generic names, so that 
the choice may have to be made not only between two 
specific names but also between the two genera. 
If the reform in nomenclature had to be made now, and 
“it was decided by zoologists that the two generations of 
the Hydromeduse were to be known by a single generic 
and specific designation, I have no doubt that in most 
cases the name of the fixed Hydroid Zoophyte would be 
chosen by the majority of working zoologists; and yet 
that is the asexual generation, corresponding to the solitary 
Salpa. If, on the other hand, the free-swimming sexual 
generation were chosen to give its name to the species, 
the result would be an almost complete change in the 
nomenclature of the group. The long established, well- 
known names of a large number of the Zoophytes would 
be swept out of use, and their places would be taken by 
the comparatively little known names of the short-lived 
inconspicuous medusoid gonophores. And yet this is the 
corresponding course to naming the species of Salpa from 
the sexual aggregated forms. 
Tn the case of the Hydromeduse, the life-histories are 
