MUSEUM OF COMPARATIVE ZOOLOGY. 237 



been taken in the Atlantic or in the Mediterranean, with the exception of the 

 problematical P. sicula, Haeck., from Messina. 



In his original description Prof. Verrill suggests that Callinema is allied to 

 Hecccedecomma ambiguum, Brandt, of the North Pacific, but finds that the 

 Eastport species differs from the Pacific in the shape and character of the ten- 

 tacles, the marginal lobes, and ovaries, and that the figures of the Pacific form 

 have much more complicated mouth-folds. I agree with Professor Verrill in 

 his conclusions in regard to the differences between the two medusae, and find 

 his medusa specifically dift'erent, not only from the published figures of the 

 Pacific Phacellophora, but also from specimens themselves, some of which were 

 collected on my recent visit to the Pacific coast. It is also believed to be 

 generically different from Heccaedecomma. 



Haeckel* suggests that Callinema is a new species of Phacellophora There 

 are close likenesses between Callinema and Phacellophora, and also differ- 

 ences which seem great enough to give the name Callinema a generic worth. 

 Haeckel, however, regards these differences as specific only, and regards Calli- 

 nema as a new species of Phacellophora. In the same genus he places three 

 other species, camtschatica, Brandt, ambigua, Brandt, and sicula, Haeckel. I con- 

 sider, as stated above, that there is a generic difference between Callinema and 

 the first two species. Of the third species, from Messina, there are no special 

 lescriptions, and no figures of the medusa as a whole, and we are wholly in the 

 ilark in regard to the structure of the mouth parts. What is known from the 

 notices by the Hertwigs f — the figures are of a quadrant of the bell and an en- 

 larged sense body — would lead me to suppose that his medusa is very close to 

 Callinema. It would seem to be a species of Callinema allied to 0. ornata. 

 Until we know more of its general anatomy, we must remain in doubt whether 

 it is more closely allied to Phacellophora or Callinema. I can heartily agree 

 with Haeckel that an exact study of the structure of the medusa considered by 

 Hertwig is very desirable. The author believes that histological researches 

 lose some of their value if not preceded by an accurate specific identification 

 or specific description of the animal studied, if it is different from known 

 species. 



*.Das System der Medusen. Acraspeden, p. 643. 



t Nervensystem und Sinnesorganen der Medusen, pp. 113, 114, Taf. IX. Fig. 

 15, Taf. X. Fig. 16. 



Cambridge, October, 1887. 



