REPORT ON THE REEF-CORALS. 187 
Genus 3. Synarea, Verrill. 
Synarexa, Verrill, Bull. Mus. Comp, Zo6l., Cambridge, U.S.A., i. p. 42. 
4 Duncan, Rey. Madrep., p. 187. 
A single species of this very interesting genus was obtained. 
Synarea convexa, Verrill. 
Synareza convexa, Verrill, Bull. Mus. Comp. Zodél., Cambridge, U.S.A., i. p. 43. 
The branches in this species are often coalescent throughout, leaving small, very 
irregular and unequal depressions on the upper surface, in which the cells are delicate 
and very closely placed. Several pieces of a large specimen were obtained. 
Locality.—Tahiti. 
Genus 4. Goniopora, Quoy and Gaimard. 
Goniopora, Quoy and Gaimard, Voy. de l’Astrol., Zooph., p. 218. 
* Milne-Edwards and Haime, Cor., iii. p. 189. 
r Duncan, Rev. Madrep., p. 189. 
A single specimen of the typical species of the genus was obtained. 
Gomopora pedunculata, Quoy and Gaimard. 
Goniopora pedunculata, Quoy and Gaimard, Voy. de JlAstrol., Zooph., p. 218, pl. xvi. 
figs. 9-11. 
x i Milne-Edwards and Haime, Cor., iii. p. 190, 
A small piece which evidently formed the outer portion of a specimen of this species 
was obtained. 
The depth of the calicles is generally slightly less than their width. The walls are 
irregularly thickened and perforated, and very nearly indistinguishable in a section of 
the corallum. The septa are somewhat thickened and narrow, with rather short teeth. 
Locality.—Mactan Island, Philippines. 
Genus 5. Rhodarxa, Milne-Edwards and Haime. 
Rhodarxa, Milne-Edwards and Haime, Cor., iii. p. 183. 
PF Duncan, Rev, Madrep., p. 188. 
Two species of this genus were obtained. 
