80 Dr. H. A. Nicholson on tioo new Oenera and 



2. The intermediate layer (together with the external layer, 

 as just remarked) is clearly formed by the coalescent branches. 

 When viewed from the outside, where the thin outer layer has 

 been stripped off, it exhibits shallow vertical grooves, marking 

 out the original branches, and it also shows in outline the 

 proximal ends of the cells below (fig. 1, E, Z*). _ 



3. Specimens which exhibit the hollow interior of the 

 funnel, from which the innermost membrane has been removed 

 in whole or in part (fig. 1, D), exhibit the mouths of the cells 

 as rounded pores placed on the inner aspect of the amalgamated 

 branches. The cells are arranged in double alternating roAVS 

 forming regularly bent or undulated lines, each of which corre- 

 sponds witli the inner surface of a branch, and wliicli, by their 

 inosculation, enclose oval spaces corresponding to fenestrules, 

 but occupied by short solid columns. 



4. Specimens which are broken across transversely (fig. 1, F) 

 show that, instead of fenestrules or perforations between the 

 anastomosing branches, we have a series of stout pillars, which 

 run perpendicularly inwards from the poriferous face, and have 

 tlieir internal ends connected together by a thin calcareous 

 membrane, which forms the innermost lining of the funnel- 

 shaped frond. There is thus formed a central space (c), which 

 is lined outwardly by the cells, and to which water can ap- 

 parently not have been admitted otherwise than by openings 

 in the margin of the funnel. 



5. Specimens which are casts of the interior of the frond, 

 to which the innermost membrane with the ends of the per- 

 pendicular columns still remain adherent, are not uncommon 

 (fig. 1, A & C). These show that the columns are so arranged 

 as to form beautifully regular diagonal lines ; and their inner 

 ends seem to have been convex, as they in many cases leave 

 concave or cupped scars of an oval or rhomboidal shape upon 

 the outside of the cast (fig. 1, B). 



6. One specimen exhibits a strong horizontal "footstalk, 

 from which the coenoecium grew up vertically (fig. 1, C). This 

 footstalk is branched at both ends ; its surface is covered in 

 parts with vermiculatcd stria3 ; and its structure seems to have 

 been minutely tubular or cellular. 



7. Lastly, some specimens show the extraordinary character 

 of a second frond, quite similar in structure to the first, in- 

 vaginated within the outer one, so as to give rise to an internal 

 cone closely applied to the external funnel. I am at present, 

 with the comparatively imperfect materials in my possession, 

 unable to offer any explanation of this remarkable feature. 



Locality and Formation. — Not uncommon, though always 

 more or less imperfect, in the Corniferous Limestone (Devo- 

 nian), Port Colborne and Lot 6, Con. 1, Wainfleet. 



