2 JOHNS HOPKINS UNIVERSITY MORPHOLOGICAL MONOGRAPHS. 
obtain them in abundance. His first physiological experiments were 
begun on August 4th and continued thereafter at intervals of several 
days until his departure from Jamaica on September 6th. 
Dr. Conant usually performed his experiments during the second 
half of the forenoon, after the animals had stood for a few hours in 
the laboratory. 
The building that was rented at Port Antonio for a laboratory 
had, in the basement, a photographer’s dark-room, which was of great 
service to Conant in his experiments. 
The experiments on Aurelia, in 1897, were also performed at 
Port Antonio, between August 6th and 9th. The experiments on 
Cassiopoeea were probably made at Port Antonio, where specimens 
were occasionally obtained. 
The notes on Aurelia and Polyclonia, in 1896, were taken at Port 
Henderson, between May 12th and June 27th. 
In his notes Conant speaks of Polyclonia and Cassiopoea. It is 
at present undetermined whether he really had both forms or whether 
he uses the two names for the same form. It seems likely that in 
1896 he thought the form to be Polyclonia, while for some reason, 
in 1897, he supposed it to be Cassiopaea. I have examined several 
specimens of these meduse brought from Port Antonio and find that 
they all have twelve marginal bodies and twenty-four radial canals, 
according to which (V, Haeckel’s System), they should be Polyclonia. 
Conant, however, speaks of removing sixteen marginal bodies, which 
seems to indicate that he had Cassiopewa. A careful classification of 
this form of meduse found about Jamaica seems to be a desideratum. 
I suppose, however, that for our purpose in this paper it will make 
little difference which name is used, the two forms being so similar 
in form and structure. I have, therefore, decided to retain both the 
names used by Conant. 
For the complete anatomy of Charybdea the reader is referred 
to Dr. Conant’s dissertation, “The Cubomeduse” (8b), or the Johns 
Hopkins University Circulars (8a), both published by the Johns 
Hopkins Press. But, for the convenience of those who may be less 
familiar with Cubomedusan anatomy, the following brief summary 
of the anatomy of Charybdea is given: 
The Cubomeduse, as the name implies, approximate cubes, with 
their tentacles (four in Charybdea) arranged at the four corners of 
the lower face of the cube. These tentacles are said to lie in the 
