of the genus are readily recognized by their thin epitheca, the presence of tabule extending 
quite across the theca as unbroken partitions, the extension of the septa to or near to the 
centre of the theca, the absence of a columella, and the generally open and uninterrupted 
condition of the interseptal loculi, except for their being partitioned off by the, tabule. In 
some of the forms of the genus, however, the continuity of the interseptal loculi is interfered 
with, not only by the tabula, but by vesicular dissepiments whiclf appear to be independent 
of the tabule ; so that there is a central tabulate area, and an external vesicular area. There 
is also evidence that the tabulze, though extending quite to the epitheca, are, in their exterior 
portion at any rate, of the nature of dissepiments placed nearly at the same level in successive 
interseptal loculi. According to Mr. Billings, also, a well developed or rudimentary columella 
may be present in Z. prolifica, this structure being otherwise unknown in the genus. 
Three species of Zaphrentis, viz.: Z. gigantea (Lesueur), Z. prolifica (Billings), and 
Z. spatiosa (Billings), have been already recorded from the Corniferous Limestone of Western 
Ontario, all of which have come under my notice, whilst I have to record an apparently un- 
described form. I have also a small cylindrical, spinulose form, allied to Z. spinulosa (Edw. 
& H.), or to Z. spinulifera (Hall), though apparently distinct, which, in the absence of specimens: 
showing the internal structure, I shall leave undescribed. 
11. ZAPHRENTIS GIGANTEA (Lesueur). 
(Plate III. Figs. 1, 1a). 
Caryophyllia gigantea -(Lesueur). 
Zaphrentis gigantea (Edwards & Haime). Pol. Foss. des Terrs. Pal. Pl. 1V., Fig. 1. 
Zaphrentis gigantea (Billings). Canadian Journal, New Series, Vol. IV., p. 121. 
Corallum simple, cylindro-conic, varying from a few inches up to two feet or more in 
length, and from one and a half to three inches in diameter, usually more or less curved. 
Cavity of the theca partitioned off by a well developed series of tabule, which are more or 
less flexuous centrally and are bent downwards as they approach the epitheca. Septa from 
seventy to one hundred or more in number, unequally developed, or alternately large and small, 
extending upon the upper surface of the tabulee nearly to the centre, where they are usually 
more or less flexuous. A single well marked septal fossette upon one side, extending nearly to 
the centre. Epitheca with numerous shallow encircling ridges and annulations of growth, which 
vary in size but are not sharp-edged ; and also with costa corresponding with the septa within, 
According to Mr. Billings, the septa in this species vary in number from seventy to 
eighty. In the examples which I have seen, however, the septa are alternately large and 
small and, counting in those of both sizes, attain to the number of one hundred or more, 
They thus come to resemble large specimens of the form described by Mr. Billings, under 
the name of Z. prolifica, from which they may be distinguished by the fact that the latter 
species is not said to attain a length of over five inches, or a little more, whilst the radiating 
septa reach the number of one hundred and twenty, or one hundred and fifty. Our specimens, 
on the other hand, must have attwined a length of from nine to twelve inches or more, and do not 
appear to have more than one hundred and ten septa at the utmost, whilst their form is eylin- 
drical, or cylindro-conical, and not turbinate. TI am notsatisfied, however, that all the examples 
which I have here included under Z. gigantea, are really referrible to this species, nor that the 
large and small forms of Z. prolifica (Billings), can be retained under a single specific title. 
Zaphrentis gigantea (Lesueur) must not be confounded with the large Carboniferous species 
described by Michelin and McCoy, under thé name of Caninia (Zaphrentis) gigantea, and by 
Edwards and Haime, under the name of Zaphiemtis cylindrica. : 
Locality and Formation.—Corniferous Limestone of Ridgeway, Port Colborne, Walpole, 
and numerous other localities in Western Ontario. 
12. ZAPHRENTIS FENESTRATA (Nicholson). ' 
(Plate IV. Fig. 1.) 
Zaphrentis fenestrata, (Nicholson), Canadian Naturalist, Vol. vii., No. 3, 1873. 
Corallum simple, cylindro-conical, curved. Tabula well-developed, remote, bending 
downwards as they approach the outer wall. Sepia strong, equally developed, extending 
