14 
Systematic position. — From the general structure, especially from 
the presence of calcareous corpuscles, it is clear that both the Japan- 
ese and the Florida parasites are cestodes; the absence of suckers 
seems to place both forms in the old family Bothriocephalidse, now 
known as Dibothriocephalidse. Further than this, the exact sys- 
tematic position is not clear at present and can not well be deter- 
mined until the adult stage is known. 
So far as can be judged from the material thus far studied (prior 
to the meeting of the International Dermatological CongiTss in New 
York, September 9, 1907), the Florida form must be considered as 
very closely allied to, perhaps specifically identical with, the Japan- 
ese form. The only anatomical point of difference thus far brought 
out is a difference in size of the calcareous corpuscles; the only bio- 
logical difference known is the habitat — in two widely separated 
localities. 
Ijima points out the structural affinities between the Japanese form 
and the bothriocephalid larva] Sjyargmnnn of Diesing; he refers also 
to the similarity, between the Japanese form and ‘‘''Ligula mansoni ” 
{^Sfarganum m.ansoni). 
Sparganum is an artificial collective group of worms, distinctly 
proposed, not as a systematic unit, but as a collective group of larval 
bothriocephalid cestodes. Under the International Code of Nomen- 
clature (1907) such names may be proposed as a matter of conven- 
ience and may be used as if they were generic names ; they do not re- 
quire any type species and hence do not compete with generic names 
under the law of priority. 
Both the Japanese and the American parasite may be temporarily 
classified in Sparganum. 
The Japanese worm was originally published under the two names 
Plerocercoides prolifer and Plerocercus prolifer., but Ijima distinctl}^ 
states that he uses the names as a matter of convenience, namehq not 
in a taxonomic sense. Certain objections arise, ho^vever, to the use 
of the names Plerocercus and Plerocercoides in this connection, and 
on this account I transferred (1906a) the parasite to Spargana:m. 
The nomenclatural points involved are somewhat complex and it 
may be well to explain them in this place. 
Under the original international code, the names of larval cestodes 
and of certain other forms were, for special reasons, exempted from 
the law of priority. Later (1901), contrary to the judgment of hel- | 
minthologists, this exemption was done away with. 
To apply the law of priority consistently to all such larval names v 
would be almost an impossibility. There are, in fact, many names 
which have been proposed, not in a generic sense, but as names of 
admittedly artificial groups, which were used simply as a matter of uj 
