23 
nearly to the centre of the coral, apparently forty-eight in number. LEpitheca thin, with a 
few shallow undulations of growth, but apparently destitute of coste. 
This species is closely allied to the preceding, but appears to be clearly distinct, though 
the above description is founded upon but a single specimen. It differs from Zaphrentis 
gigantea chiefly in the greater proportionate thickness and much smaller number of the septa, 
and the greater remoteness of the tabulee. The former of these characters, as well as the fact 
that the septa are equally developed, separates it from Z. prolifica. 
The tabulee of the circumference of the coral, where they bend downwards to meet the 
epitheca, seem to be clearly of the nature of dissepiments, as they are not placed at exactly 
the same level in contiguous interseptal loculi. The specific name is intended to commemo- 
rate the peculiar fenestrated appearance exhibited by portions of the coral from which the 
epitheca has been removed, when the interseptal loculi are seen to be crossed at intervals of from 
two to three lines, by the obliquely descending tabulze, producing a series of oblong fenestrules. 
Length‘ of the only specimen observed, five inches; diameter of summit, one and a half 
inches ; calice and fossette, unknown. ?, 
Locality and Formation.—Corniferous Limestone, Port Colborne. 
13. ZAPHRENTIS PROLIFICA (Billings). 
(Plate III., Figs. 2, 2a.) 
Zaphrentis prolifica (Billings), Canadian Journal, New Series, Vol. iv., p. 121. figs. 22, 
23. 
“Corallum simple, turbinate, curved, with a few broad, shallow, encircling folds. Sep- 
tal fossette of a pyriform shape, gradually enlarging from the margin towards, but not quite 
reaching, the centre; variable in its position in relation to the curvature of the fossil. Kadiat- 
ing septa in the adult specimens between sixty and seventy of the larger size, alternating with 
a like number of smaller ones ; the former, in some of the individuals, extending to the centre 
on the bottom of the cup, where they are spirally twisted or irregularly contorted ; in other 
specimens, not reaching the centre, which is then occupied by a smooth space, or often with 
a columella elongated in a direction from the septal fossette towards the opposite side. The 
septa are also sharp-edged for almost half the distance from the bottom of the cup to the 
margin, then become gradually less projecting, until at the edge of the cup they are reduced 
to mere flat rounded ridges. Length, from four to five inches, or a little more ; width of cup, 
- from two inches to two inches and a-half ; depth of cup, about one inch.” 
“ Very numerous specimens of young individuals of this species, one inch and a half and 
upwards in length, and with fifty or more principal radiating septa, occur with those fuil 
grown. ‘These smali ones might perhaps be regarded as constituting a distinct species, but 
when good specimens can be observed they all exhibit the characters which are persistent in 
the large individuals ” (Billings). 
Whilst having the impression that the small examples just alluded to are specifically dis- 
tinct from the larger ones with which they are united by Mr. Billings, I must freely admit 
that our collections are not sufficiently extensive for me to pronounce a decided opinion upon 
the subject. Large specimens, indeed, having the characters ascribed by Mr. Billings to 7 
prolificu, are far from common, and I have not come across more than four or five ; whilst the 
smaller examples are exceedingly abundant, 
The larger examplesare distinguished from Z. gigantea, by their smaller dimensions, their 
turbinate form, the shape of the fossule, and the much greater number of the septa and their 
rounded edges where they approach the margin of the cup. 
The smaller examples, as a rule, exhibit characters by which they can be readily distin- 
guished. They are most commonly about an inch and a half in length, but vary from three 
quarters or an inch up to three inches. The ealice is very deep, but is extremely oblique, its 
greatest height being on the side of the convex curvature of the coral. The septa are alter- 
nately large and small, and the primary septa are always more or less bent and contorted as 
they approach the centre. The tabulz are bent downwards on approaching the wall. The 
epitheca in perfect specimens exhibits a few broad and rounded undulations of growth, with 
obscurely marked costz corresponding with the septa within. More commonly the epitheca 
is denuded, being very thin, when the edges of the septa appear conspicuously on the surface of 
the coral. 
