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 

 Cassiopoea 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 Cassiopoea. I have examined several 

 specimens of these medusae 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 Cassiopoea. A careful classification of 

 this form of medusas 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 Cubomedusas" (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 Cubomedusaa, 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 



