1871.] MR. W. S. KENT ON NEW MADREPORES. 283 



of the polype-cells, and in miniature they bear a certain resemblance 

 to the nariform calices of various species of Madrepora ; their true 

 relationship, however, is probably identical with the many-patterned 

 intercalicinal developments peculiar to the genera Montipora and 

 Styloccenia. 



Subfamily Stylophorin^e. 

 Pentalophora, n. gen. 



Reussia, Michelotti, Mem. sur les Corall. des Antilles, p. 63, 1860. 



This new generic name is proposed in substitution for that of 

 Reussia, in consequence of the latter having been used by Presl in 

 1838 to distinguish a genus of fossil ferns. 



The single species referable to this genus, Reussia lamellosa 

 (Mich.), is remarkable for its septal system being composed of a 

 multiple of five, each calice being furnished with ten evenly developed 

 septa, which are united internally to the stylate columella. The 

 constant quintuple arrangement of the septal elements isolates this 

 form from all known Madreporaria ; in other respects it is closely 

 allied to the genus Stylopora. 



Family Astreid^e. 

 Tridacophyllia alcicornis, n. sp. (Plate XXIII. fig. 4.) 



Corallum slender, elevated ; margins of thecae produced into elk- 

 horn-like prolongations. Columella absent. Septa forming three or 

 four cycles, their internal edge dentate or lacinate, their lateral surfaces 

 granulate. Costas prominent, echinate. Epitheca rudimentary ; en- 

 dothecal dissepiments little developed. 



Hab. San Cristoval, Solomon Islands. B.M. 



This species differs from those previously described in the branch- 

 ing instead of foliaceous character of the walls of the thecae. 



Tridacophyllia echinata, n. sp. (Plate XXIII. fig. 3.) 



Corallum infundibuliform, foliaceous ; margins of thecse bidentate, 

 little elevated. Columella moderately developed, trabecular. Septa 

 forming four or five cycles ; the primaries and secondaries prominent 

 and equally developed, having their internal edge remarkably 

 thickened, coarsely tuberculate and echinate ; the remaining septa 

 little developed, denticulate or slightly echinate. Costae not pro- 

 minent, almost even, finely granulate. Epitheca moderately de- 

 veloped. Endothecal dissepiments of large size at the base of the 

 corallum. 



Hab. San Cristoval, Solomon Islands. B.M. 



This species is at once recognized by the anomalous character of 

 the primary and secondary septa. 



Oxypora*, gen. nov. 



This name is proposed in place of Trachypora of A. E. Verrill 



* 6£i's, sharp, cutting. 



