24 BULLETIN : MUSEUM OF COMPAKATIVE ZOOLOGY. 



Comparison of the Bahama-Tortugas Fauna with that of the 

 Fiji Islands and Tropical Pacific. 



In 1897, A. Agassiz and the author made a study of the Acalephiau 

 fauna of the Fiji Islands, South Pacific, in 18° S. Lat,, 178° E. Long, 

 from Greenwich. The results of our investigations have been published 

 in the Bulletin of the Museum of Comparative Zoology at Harvard Col- 

 lege, 1899, and we there show that the Hydromedusse and Siphonophorse 

 of the Fiji Islands are very closely related to those of the Tortugas, 

 Florida. All of the Hydromedusae and Siphonophorse found by us in 

 the Fiji Islands belong to well-known Atlantic genera. In the case of 

 the Hydromedusae 4 Fijian species are so closely related to forms fouud 

 at the Tortugas that we are unable to distinguish any specific diflfer- 

 ence between them, and therefore we venture to assert that they may 

 be identical species. These forms are ^Eginella dissonema, Halitiara for- 

 mosa, Paudea violacea, and ^quorea floridana. It will be observed that 

 only one of these identical species belong to the Trachylina (i. e. A. 

 dissonema), the other three being Leptoliua forms. In addition to the 

 species already mentioned, the following genera of Hydiomedusa; are 

 represented both in the Fiji Islauds and in the Tortugas by very 

 closely allied, although distinct species, — Aglaura, Eutima, Laodicea, 

 Oceania, Epenthesis, and Tiaropsis. 



Among the Siphouophorge (Abyla quincunx, Aglaisraa quincunx) and 

 Agalma Pourtalesii are found both at the Tortugas and Fiji Islands. 

 Sphperonectes KoUikeri of the Fiji Islands and Tropical Pacific is cer- 

 tainly very closely allied to Sphaeronectes gracilis of the Tortugas and 

 Tropical Atlantic ; and the two species may eventually prove to be 

 identical, and the same may be said of Nectophysa Wyvellei. 



The ScyphomedusEG of the Fiji Islauds are with two exceptions 

 quite distinct from those of the Tortugas, for there are a number of 

 characteristic Rhizostomata in the Si)uth Pacific that have no near 

 allies in the Atlantic Ocean. We find, however, in the Fiji Islands a 

 variety of Nausithoe punctata that may prove to be specifically identi- 

 cal with the form found at the Tortugas and in the Mediterranean. 

 Another form, Linerges aquila, of Fiji is closely allied to, although 

 distinct from, L. mercurius of the West Indies. 



Among the Ctenophorae of Fiji, Eucharis grandiformis is a species that 

 bears quite a close resemblance to E. multicornis of the Atlantic and 

 Mediterranean, although it is certainly specifically distinct. 



We must conclude, then, tliat the Acale])hiau fainia of the Fiji Islauds 

 is almost as closely related to that of the Tortugas as tlic latter is to 



