822 WINTERTON C. CURTIS : 
younger than the one here shown. In such a young condition it 
lives in the intestine of its teleost host, moving freely about and 
attaching itself by means of its four suckers. The slightly older 
stage which these figures represent and which was used in my 
experiments, is found in the cystic duct of some of these fishes, 
notably the squeteague and the common flounder. ‘The speci- 
mens which I used for infection purposes all came from the first | 
of these two hosts. 
The name Scolex polymorphus originated with Rudolphi (08) 
and has since been frequently applied to such larval forms taken 
from many different fishes, and by Van Beneden (’50) from crabs of 
the genera Carcinus and Eupagurus. Zschokke (’86), discussing 
such forms, showed that the mono-, bi- and triloculate types of 
bothria (figs. 2, 12 and 13 of the present paper), which can be dis- 
covered when any considerable number of individuals are exam- 
ined, are only developmental stages of the same form, and his 
results indicated that the 8. polymorphus with which he worked 
was the young of the genus Calliobothrium, and not of-Oncho- 
bothrium as had been previously suggested. These authors of 
course studied specimens from European waters. 
Monticelli (’88) in an extensive paper upon the S. polymorphus 
of the region about Naples, showed that the larvae, which he 
found in a large number of fishes, though most common in the 
flounders, were the young of Calliobothrium filicolle. This 
conclusion was based upon the close anatomical resemblances 
between the more advanced larvae and young specimens of C. 
filicolle and upon experiments in which a species of Torpedo, 
after being freed of all parasites by starving (a method which his 
experience and that of the collectors at the Naples station had 
shown to be effective), was then fed for a time upon specimens 
of Arnoglossus known to contain the 8. polymorphus. As a 
result of this, young specimens of the C. filicolle were obtained 
from the torpedoes so treated, and this taken with the anatomical 
resemblances seemed conclusive evidence. Monticelli has re- 
viewed the literature exhaustively and he gives (p. 89) a list of 
thirty-six cases in which authors have appended various specific 
names to the term scolex and made as many different species 
