99 
distinct carine. From Retepora, again, Polypora will be distinguished solely by the fact that 
the branches in the latter genus are united by distinct poriferous or non-poriferous dissepi- 
ments, whilst in the former the branches simply anastomose or inosculate. 
McOoy states that no infundibuliform species of Polypora had come under his notice ; but 
I have seen such, and in these cases the cells are born by the inner faces of the branches. 
The following species of Polypora have come under my notice m the Corniferous Lime- 
stone of Western Ontario :— 
120. PoLYPoRA PULCHELLA (Nicholson). 
Polypora pulchella (Nicholson), Geological Magazine, April, 1874. 
Polyzoary infundibuliform or flabellate, often attaining a considerable size. Branches 
nearly straight, radiating from the base, and increasing in number by bifurcation at interyals 
of from two to four lines. About six branches in the space of a quarter of an inch, the diame- 
ter of the branches being about one-forty-fifth inch, the interspaces slightly narrower. Dis- 
sepiments on the same plane as the outer surface of the polyzoary, depressed below the inner 
surface, short, narrower than the branches, and placed at intervals of about half a line apart. 
Fenestrules regularly oval, half a line in length, and about a quarter of a line broad, four or 
five in the space of a quarter of an inch, alternate or sub-alternate in contiguous rows. The 
upper or inner surface of the branches carries the pores or cells, three rows of which occur 
on every branch, and sometimes four opposite the origin of the dissepiments. The cells are 
flask-shaped, sometimes slightly unequal in size ; their mouths round ; those of the central 
row alternating with the lateral rows. From six to eight pores in the space of a line, or 
three to four in the length of each fenestrule. The reverse face of the polyzoary is smooth or 
obscurely striated. 
P. pulchella belongs to that section of Polypora in which 
the dissepiments do not carry pores. The species to which it 
is most nearly allied is the P. Halliana of Prout, from the St. 
Louis group of Illinois. It is, however, readily distinguished 
by the greater development of the dissepiments, the greater pro- 
portionate and absolute width of the fenestrules, and the pos- 
session of three (instead of four) rows of cells on each branch. 
All my specimens are fragmentary, but the species must have 
attained a large size, the funnel-shaped polyzoary having in 
“Aes one example a diameter of three inches. 
ia is Locality and Formation.— Common in the Corniferous 
: Se fssey Limestone of Port Colborne, and Lot 6, Con. 1, Wainfleet. 
Fig. 35.—a. Fragment of Polypora 
pulchella (Nich.), natural size; 6. por- 
tion of the reverse of the same magni- 
fied ; c. fragment from which the ex- 
terior non-poriferous face has been strip- 
ped away, enlarged to show the cells; d. 
cast of the inner snrface, enlarged, show- 
ing the cell-mouths, From the Corni- 
ferous Limestone. 
121. Potypora Hatirana (Prout). 
Polypora Halliana (Prout), Proc. St. Louis Acad. Sci., Vol. I., p. 580. 
Polypora Halliana (Prout), Geology of Illinois, Vol. IL., plate XXI, Figs, 4-40, 
Polyzoary essentially similar in its characters to the preceding, but differing in its dimen- 
sions and the number of the rows of cells. Coencecium forming broad flattened expansions, the 
branches of which radiate from the base, increasing by bifurcation at intervals of from three 
lines to half an inch. The branches are round, nearly half a line in width, about four or five 
in the space of a quarter of an inch. issepiments small, depressed, not more than a fiftieth 
of an inch in width, often appearing to be little more than connecting points between the 
branches. Fenestrules long-oval, one line or nearly in length, and about half a line or less in 
width ; about three in a quarter of an inch measured longitudinally, and the same number in 
the space of two lines measured transversely. No pores upon the dissepiments. Cells arranged 
in four alternating rows upon the branches, their apertures rounded ; about four to the length 
