16 NEW ZEALAND PALAEONTOLOGY. 



branclied forms with compact coenencliyma, smooth or slightly 

 costate near the cells^ which are of moderate size^ more or less 

 filled up belov/. Septa 12 to 48 or more^ iu several unequal 

 cycles^ the edge of the principal ones entire. The learned Pro- 

 fessor has shown also that the species of Oculina, when young, 

 are encrusting and bud like Astrangice, some of them always 

 remaining nearly in this condition. It will be understood, how- 

 ever, that this is a very different state from the permanently- 

 spreading form of the genus now erected, in which all the cells 

 are of equal height, and forming with the coenenchyma a per- 

 fectly level surface. 



Platyhelia distans, n. s. Corallum with a very compact 

 tissue. Calices quite immersed, with faint radiating costa, 

 corresponding to all the septa, either extending a short distance 

 or as far as a faint hexagonal margin which bounds some of 

 the coraliites. Septa thick, granular, in six systems of four 

 cycles, the fourth incomplete in some systems. Pali round, 

 tubercular, before the two first cycles only. Columella a single 

 tubercle rather larger than the pali. No endotheca. Dermic 

 tissue very dense, hard, white, compact, like ivory. Calices 

 about four millim. in diameter, and the depth of the encrusting 

 mass about the same. The appearance of this coral is a good 

 deal like some of our existing Plesiastnea. App. Off. Cat., p. 38, 

 No. 45. Awamoa beds, Oamaru, Otago ; IV. Fig. 16. 



Genus — Amphihelia. M. -Edwards and Haime, 1849. 



Branched corals without pali ; coraliites with entire septa, 

 alternate and separated by an abundant compact coenenchyma. 



This was until lately a genus with only two known species, 

 one of which was Australian, and one belonged to the Mediter- 

 ranean. Deep-sea dredging has revealed a good many more, 

 and three fossil forms have been found in the Australian ter- 

 tiaries. It appears to have been well represented in the New 

 Zealand Tertiary seas. 



Amphihelia intricata, n. s. This is a worn specimen, in 

 which the cylindrical stems send off branches at right angles, 

 to unite with parallel stems, forming an intricate tuft. There 

 are no costa, but the whole surface is granular, hispid, or 

 verrucose. No perfect caiice visible. In a few of the broken 

 ones the septa are represented by mere grooves. The species 

 may be distinguished by its hispid, granular surface. App. 



