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NOTE onthe SPECIFIC NOMENCLATURE of SALPA. 
By W. A. Herpman, D.Sc., F.L.S., 
PROFESSOR OF NATURAL HISTORY IN UNIVERSITY COLLEGE, LIVERPOOL. 
[Read 11th February, 1888.] 
Ir is well known that the life-history of Salpa is an 
example of alternation of generations. Each species has 
two forms, the solitary or asexual (proles solitaria) and 
the aggregated or sexual (proles gregata). The solitary 
Salpa has no reproductive organs, but it produces an out- 
growth or stolon, which segments into a double series of 
young aggregated S Ipw united together to form a chain. 
After remaining in the chain condition for a time these 
aggregated Salpw separate from one another, and each 
then has in its interior one or two embryos produced 
sexually: these embryos become solitary Salpw. So, in 
short, the solitary Salpa produces asexually a chain of 
aggregated Salpw, and each aggregated Salpa produces 
sexually a solitary Salpa—the two generations and the 
two methods of reproduction alternating regularly. 
This condition of the life-history, and the fact that in 
some species the two forms had been found separately and 
described before their relationship to one another was 
discovered, has led to the application of two specific names 
to such species—not as synonyms, but the one name 
applicable to the solitary generation and the other to the 
aggregated. Thus in the case of a very common and well- 
known species the solitary form is named Salpa runcinata, 
Chamisso, and the aggregated form Salpa fusiforms, 
Cuvier, and it has become customary when writing of the 
species as a whole to use both names and both authorities, 
thus :—Salpa runcinata-fusiformis, Cham,-Cuy. 
