248 BULLETIN : MUSEUM OF COMPAKATIVE ZOOLOGY. 



dissonema Haeckel, x\glaura prismatica Maas, Nausithoe punctata Kol- 

 liker, aud Diphyopsis appendiculata Agassiz and Mayer. These are 

 all forms of very genei'al distribution, and all either occur in the Atlantic 

 or ai"e represented there by exceedingly close allies. Of the thirteen 

 genera common to both regions, not one is peculiarly Pacific ; and the 

 most characteristic Pacific forms, the Rhizostomae, were not found at 

 all in the Maldives. This is of interest in view of their common occur- 

 rence in the Red Sea and the Persian Gulf, and off" Zanzibar. (Van- 

 hoffeu, E. Untersuch. liber Semaeostome und Rhizostome Medusen. 

 Bibl. Zool., bd. 1, heft 3, 51 ; and Chun, Beitrag. Zum. Kentniss ost 

 Afric. Medusen, etc., MittheiL Nat. Mas. Hamburg, jahrg. 13, p. 5, 

 1896.) 



If we turn now to the Tortugas in the tropical Atlantic (Mayer, A. G., 

 Bull. Mus. Comp. Zobl., vol. 37, no. 2), we find they have in common 

 with the Maldives the following fifteen genera : Aeginella, Aglaura, Bou- 

 gainvillia, Dipurena, Gonionemus, Liriope, Oceania, Aurelia, Nausithoe, 

 Diphyopsis, Physalia, Porpita, Beroe, Bolina, and Ocyroe. Of these, 

 however, four only are represented by identical or even by exceedingly 

 closely allied forms; these are Dipurena fragilis, Aeginella disso- 

 nema Haeckel, Aglaura hemistoma Haeckel, and Nausithoe punctata 

 KoUiker. 



A similar comparison with the Mediterranean shows twenty-one genera 

 in common, but only two species, Aeginella dissonema Haeckel and 

 Nausithoe punctata Kolliker ; with two more, Rhopalonema typicum 

 Maas and Aglaura prismatica Maas, represented by very closely allied 

 forms. With the exception of the new genus Timoides, every genus 

 found in the Maldives is well known in the Atlantic, and the following 

 typically Atlantic genera, not recorded from the Pacific, were taken in 

 the Maldives. These are Berenice, Turritopsis, and Ocyroe. 



General Conclusions. 



The Medusa fauna of the Maldives shows a very general resemblance 

 to that of the Tortugas in the Atlantic and Fiji in the Pacific, as shown 

 by the large number of genera which they possess in common. But the 

 fact that very few of these genera are represented by identical species, 

 and, still more important, that all such identical species are forms well 

 known to be of very wide distribution throughout the tropical waters 

 of the globe, is good evidence that this Maldive fauna has no recent rela- 

 tionship to either of the other areas. The general resemblance of the 



