Dr. O. J. Hinde — Western Australian Fossils. 195 



Distribution. — Devonian (?). Opposite Mount Krauss, Kimberley 

 District. Also from the Gascoyne Paver. 



Cyathophyllum depeesstoi, Hinde, sp.n. Plate VIII. Figs. 2a, 2b. 



Corallum compound, consisting of several subcylindrical corallites 

 growing from a simple base : tbe individuals are for tbe most part 

 free ; when full-grown, about 17 mm. in diameter. There are about 

 58 septa, alternately large and small ; some of the larger extend to 

 the centre of the calice, and slightly curve round. The parietal 

 margins of the septa are very thick, and there is an outer zone of thick 

 dissepiments. The wall and septa of the same character as in the 

 preceding species, from which it is distinguished by its mode of 

 growth, the larger size of the corallites, and the stouter septa. 



Distribution. — Devonian? Opposite Mount Krauss, Kimberley 

 District. Another fragmentary specimen, partly incrnsted by 

 Stromatoporella Eifeliensis, Nicholson, is labelled from the Gascoyne 

 Kiver. 



Genus Plekophyllum, 1 Hinde, gen. nov. 



Syn. (?) Pentaphyllum, 2 De Koninck, 1872, preoccupied in 1821 for 

 a genus of Coleoptera. 



Generic Characters. — Simple, conical, turbinate or subcylindrical 

 corals, with deep calices. There are usually five prominently 

 developed septa (in some species only four), which reach nearly to 

 the centre of the calice ; the other septa are subequal. In the species 

 with five prominent septa, the cardinal septum is small and is 

 bounded on either side by a large septum, and the remaining three 

 large septa represent the counter and alar septa. Where only four 

 prominent septa are developed, one of them constitutes the cardinal 

 septum. Both large and small septa exhibit a distinct opaque 

 median lamina, which begins within the substance of the wall, and 

 is inclosed by successive layers of stereoplasm, so that in the lower 

 portion of the coral the septa are laterally in contact, and the inter- 

 locular and central areas are filled up with solid tissue. The wall 

 of the coral is thick, and consists apparently of the coalesced parietal 

 margins of the septa with an outer epithecal layer. The outer 

 surface exhibits either shallow annulations of growth with fine 

 concentric striee, or longitudinal rugas, or, more rarely, spinous 

 projections. 



I had at first placed the Australian Corals on which this genus is 

 based in Pentaphyllum, De Kon., but it appears that this term had 

 been previously employed, and as, moreover, some doubt 3 rested on 

 the characters of the Belgian types, it seemed preferable to prepare 



1 T\\4\pi\$, full, in allusion to the way in which the corallum is filled up by 

 stereoplasm. 



2 Nouvelles Recherches sur les Animaux fossiles du terrain Carbonifere de la 

 Belgique, p. 58. 



3 For example, the main characteristic of Pentaphi/llum is stated to be the 

 possession of five prominent septa, but in the figure of the unique .typical species, 

 P. armatum {I.e. pi. iv. fig. 8«.), six are clearly shown; whilst in the only specimen of 

 the othe'r species included by De Koninck in this genus, P. caryophyllatum, there 

 are but four prominent septa {I.e. pi. iv. fig. 9). 



