POLYPORA. 175 



branches is peculiar, frequently being not by the divarication of a branch, but by 

 the addition of a new branch on the top of a fenestrule, in which case no dissepi- 

 ment occurs. Hence this species seems to stand midway between the types of the 

 two genera, and perhaps intimates that there is no true reason for the existence 

 of King's genus Phyllopora. 



It is rare that specimens preserve the minor structure, but in the largest 

 specimen in the Torquay Museum (PL XVIII, fig. 2) the arrangement and shape 

 of the cells seems to be in a fair state of natural preservation, and to exhibit the 

 above-mentioned features, while transparent sections made from some of my 

 specimens seem to show that the free part of the cells formed a kind of saw-edge 

 (in section), truncated above by the minute, thickened, circular foramina ; and a 

 small specimen, which was destroyed for the purpose of obtaining transparent 

 sections, retained one orifice which seemed to be perfect and to consist of a raised 

 circular foramen parallel to the branch. 



The second of the two specimens in the Torquay Museum seems very different 

 in its mode of growth from the rest. It has decidedly smaller and squarer 

 fenestrules, arranged in oblique rows instead of along radiating branches, and 

 numbering five fenestrules to 10 mm. either way across the diagonals, and seven 

 to 10 mm. either way across the sides of the squares. Thus it closely resembles 

 the specimen from Mudstone Bay in the Museum of Practical Geology which was 

 figured by Phillips 1 as Gorgonia ripisteria, Goldfuss, 2 except that its fenestration is 

 much smaller. Having carefully examined Phillips's fossil, I am strongly under the 

 impression that it is only an example of the present species, masked by the squeezing 

 and consequent sheering of the matrix, which has drawn out the fenestrules into 

 a lozenge-shape and confused them with the dissepiments. The fenestrules are 

 really little if at all larger than is usual in the Lummaton specimens, Phillips's 

 figure being slightly magnified and in other respects not very accurate. In 

 neither of these two specimens can I see any real signs of cells or foramina, so 

 that we can only presumptively identify them at present. The original G. ripis- 

 teria of Goldfuss resembles it in general form as far as may be judged from his 

 figure ; but, as he describes the non-poriferous face to be strongly striated, we may 

 conclude that his Carboniferous fossil is at least specifically distinct. 



It may be observed that, though our specimens show the form to have been more 

 or less infundibuliform, they do not show whether it was regularly cup-shaped or 

 more inclined to be frondescent. 



The original specimen from Barton, described by Phillips as Betepora prisca, 3 

 Goldfuss, is in the Lee Collection of the British Museum, and undoubtedly belongs 



1 1841, Phillips, 'Pal. Foss.,' p. 20, pi. xi, figs. 30 a, b. 



- 1827, Goldfuss, ' Petref. Germ.,' vol. i, p. 19, pi. vii, figs. 2 a, b. 



3 Ibid., vol. i, p. 103, pi. xxxvi, figs. 19 a, b, c. 



