66 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Juiie 14, 



marked within their area, reminding the ohserver of the network 

 progressively formed within the excurrent channels of corneous 

 sponges. In one of the thin slices which were obtained, the cavities 

 had a partial tendency to an elongated form, in consequence of a more 

 vertical intersection, but the range was in no case sufficient to assist 

 in determining the inward characters of the channels. 



Dark waved lines in one section proved that accidentally-destroyed 

 surfaces had been covered by lateral extensions from adjacent living 

 portions. 



The second fossil to be considered is apparently the Heteropora 

 of the published lists *, specimens procured for the describer from 

 the Council of the Geological Society, by Dr. Fitton, having that 

 generic name on their tablet ; but this coral is not the one previously 

 believed to have been assigned to the genus. In the collection with 

 which the author was first favoured, no specimen of the present fos- 

 sil was included ; and it was inferred, that another without a label 

 was the Heteropora of the lists {op. cit. p. 327*,Chis)na furciUafmn) . 



The coral to be examined is branched (PI. IV. fig. 5) ; and the 

 whole surface is beset with two varieties of pores (fig. 5*) — one, well- 

 defined and circular, and surrounded, when perfect, by a projecting 

 margin ; the other smaller, and variable in form, margin not raised : 

 internally (fig. 6) the coral consists of tubes more or less distant and 

 divergent, being continuations of the circular surface-apertures ; and 

 they are crossed at unequal distances by transverse laminae (6*): be- 

 tween the tubes is a cellular structure, represented on the surface by 

 the minor pores, and disposed in layers, which may be separated me- 

 chanicallv (fig. 7, 8), and are rendered \isible in weathered surfaces 

 (fig. 5).^ 



Heteropora was proposed by M. de Blainvillef for three Maestri cht 

 fossils which M. Goldfuss had included in his genus Ceriopora^. 

 The essential characters given by its proposer consist in the surface 

 having *' cellules de deux sortes, les unes bien plus grands que les 

 autres ;" and the lobes or branches are stated to be composed " de 

 couches enveloppantes." (loc. cit.) M. de Blainville however says, 

 that he had never examined a species in detail (analyse). Milne- 

 Edwards §, in his remarks on the genus, considers the minor pores not 

 to be the apertures of cells, but " des pores pratiques dans les parois 

 des cellules, dont les grands trous seraient les ouvertures ovales, struc- 

 ture dont on voit beaucoup d'exemples parmi les Eschares," &c. 

 He nevertheless adopted the genus, and removed to it the Millepora 

 clumetosa and M. conifera of Lamouroux || . Many other authorities 

 have retained the genus, with two sorts of cells or pores as the essen- 

 tial character. 



* Quarterly Journal Geological Society, vol. iii. No. for August 1847, p. 296, 

 " Heteropora ? " p. 302, " Heteropora." 



t Manuel d'Actinologie, p. 417, 1830-1834. 



X Petrefacten, C. cryptopora, p. 33. pi. 10. fig. 3 ; C. anomalopora, p. 33. pi. 10. 

 fig. 5 ; and C. dichotoma, p. 34. pi. 10. fig. 9. 



§ Lamarck, 2nd edit, tome ii. p. 317, 1836. 



II Exposition Methodique, p. 87. pi. 82. fig. 7, 8 ; and pi. 83. fig. 6, 7. 



