104 
4, Specimens which are casts of the interior of the frond, to which the innermost mem- 
brane with the ends of the perpendicular columns still remain attached, are not uncommon 
(Fig. 40 4 & C). These show that the columns are arranged in beautifully regular diagonal 
lines ; and their inner ends seem to have been convex, as they leave in many cases concave or 
cupped scars, of an oval or rhomboidal shape, upon the outside of the cast (Fig. 40 B). 
5. One specimen exhibits a strong horizontal foot-stalk, from which the frond grew up 
vertically (Fig. 40 C’). This foot-stalk is branched at both ends, its surface is covered in 
parts with vermicular striz, and its structure appears to have been minutely tubular or cellular. 
6. Lastly, some specimens appear to show the extraordinary character of a second frond, 
quite similar in structure to the first, invaginated within the outer one, so as to give rise to an 
internal cone closely applied to the internal surface of the external funnel. It is possible, 
however, that this appearance may admit of some other interpretation. 
I have treated this species at some length on account of its very remarkable and compli- 
cated structure ; but there are still several points connected with it which I have been unable 
to make out with my present materials. Specimens are by no means particularly rare, but I 
have seen none which are not fragmentary. 
Locality and Formation.—Corniferous Limestone of Port Colborne and Lot 6, Con. 1, 
Wainfleet. 
Genus FENESTELLA (Lonsdale). 
Polyzoary forming a calcareous, flattened or infundibuliform expansion, composed of sub- 
parallel branches, which radiate from the base, and are united laterally by cross-bars or disse- 
piments, so as to form a network, the meshes of which are in general more or less oblong or 
sub-quadrate. One surface of the branches (in the infundibuliform species the inner surface) 
is rounded and covered by a dense, striated or minutely porous layer. The opposite surface 
of the branches (in the infundibuliform species the outer surface) is furnished with two rows of 
short tubular cells, the mouths of which are separated by a more or less prominent carina or 
keel. The dissepiments. are usually without cells. Occasionally a row of small cells upon 
the mesial keel (the Fenestrellina of D’Orbigny). 
Fenestella differs from Letepora in possessing distinct dissepiments, and in not having 
the fenestrules formed simply by the coalescence of the branches ; whilst the cells are separated 
by a distinct keel. From Polypora (McCoy), Fenestella is separated by having only two 
principal r5ws of cells, and usually only these two, the third row if present being very minute, 
whilst the lines of cells are separated by a carina. 
The following species of Fenestel/a occur in the Corniferous Limestone and the Hamilton 
group of Western Ontario ; though there are others which cannot be determined until more 
complete materials shall have been collected. 
127. FENESTELLA MAGNIFICA (Nicholson): 
Polyzoary forming a flattened expansion of unknown but apparently considerable size. 
Branches almost perfectly straight, bifurcating at intervals of from one quarter of an inch to 
one inch, nearly parallel, united by straight transverse 
\ =! = dissepiments, sub-angular or obtusely carinated and closely 
| striated on the non-celluliferous side. About four branches 
\ in the space of a quarter of an inch measured across the 
frond. Dissepiments about the same in diameter as the 
branches, usually placed at intervals of from one line to a 
) ‘a tenth of an inch apart. Fenestrules oblong, rectangular, 
Zz» 2 nearly equal, from one line to one-tenth of an inch in 
| a length by two-thirds of a line in width, nine in one inch 
measured vertically, and twelve in the same space mea- 
j —J ® sured diagonally, placed nearly but not quite at the same 
y 
f | level in contiguous rows. Celluliferous face unknown. 
i This species (Fig. 41) is most nearly allied to Men- 
Fig. 41. estella lava (Phillips), from the Carboniferous and De- 
a, Portion of the polyzoary of Fenestella yonian Rocks of Britain; but it is readily distinguished 
magnifica (Nich.), natural size ; b. a fragment A ° 
of the same enlarged. From the Corniferous by the regular dimensions of the fenestrules, their rectan- 
Phish cular shape, and their much smaller size. (The fenestrules 
