372 HYDROID^. Part IV. 



M Family. Abylid.e A(/. — Diijhyiclte Axct. 



Abyla Q. and G., Esch. (p. p.). — Amphirhoa LeS. — Cymba Q. and G. — 

 Enneagonum Q. and G. — Microdiphyes Less. (p. p.). — Hetero- 

 diphyes Less. (p. p.). 



A. trigona Q. and G., Ann. Sc. Nat., Vol. X. PI. 2, B ; Vogt. PI. 



20, figs. 4-7 ; Geucnh., Neue Beitr., Pis. 27 and 28, figs. 9-12.— 

 Diphyes Abyla Q. and G., Zool. Astr., PL 4, figs. 12-17.— 

 Salpa polymorpha Q. and C, Zool. Uran., PI. 73, figs. 4 and 

 5. — Ilediierranean (Quoy and Gaimard). 



Calpe Q. and G. — Abyla Lsch. (p. p.). — Eudoxia Esch. (p. p.). — 

 Cuboides Q. and G. — Aglaisma Esch. — Aglaismoides IIiul. — 

 Tetragonum Q. and G. — Pyramis Otto. 

 C. pentagona Q. and G. — Abyla pentagona Esch. ; LciicJc, Zool. 

 Unters., PI. 3, figs. 1-10, Arch. Nat., 1854, PI. 11, 1-10 ; /fo//., 

 PI. 10; Gegent)., Neue Beitr., PI. 29, figs. 17 and 18; Huxi., 

 PI. 2, fig. 2. — Mediterranean (Quoy and Gaimard). 



Bassia Q. and G. — Calpe Less. (p. p.). — Splienia IIuxl. — Sphenoides Hu.xl. 



B. quadrilatera Q. and G., in DeBl. Actin. — Diphyes bassensis Q. 



and G., Zool. Astr., PI. 4, figs. 18-20; LIml., PI. 2, fig. 1.— 

 Bass Straits (Quoy and Gaimard.) 

 B. perforata Jig. — Abyla perforata Gegenh., Neue Beitr., PI. 31, figs. 

 20 and 21 — Coast of Guinea (Gegcnbaur). 



SECTION II. 



GEOGRAPHICAL DISTRIBUTION OF THE HYDROID.i:. 



Our knowledge of these Acalephs is limited to those of so small areas of 

 the surface of our globe, that it is impossible to characterize the faunte into which 

 they may be divided; nevertheless, from the fragmentary information on hand, it 

 already appears that these Hydroids are locahzed within narrow boundaries, with 

 as much precision as the higher orders of the class. The Diphyidaj alone seem 

 to make an exception; but I suspect that in this family, closely allied represent- 

 ative species have been mistaken as identical. There are in the Museum of Com- 

 parative Zoology at Cambridge, a great many undescribed Hydroids from various 

 parts of the world, which, when published, may lead to some general results respect- 

 ing the mode of association of these animals with the higher Acalephs, and the 

 representatives of other classes in their respective zoological provinces. 



