Page images

outer lip, nor the ridge on the inner, that is exhibited by A. suborbi. cularis ; while A. squamosa, although possessing the ridge, does not seem to have the groove ; and besides, the cells are in general linear, instead of sub-oval or sub-polygonal.

Locality and formation. Township of Cayuga. Corniferous Limestone.

Collector.-J. De Cew.


Canadian Journal, Vol. IV. page 115. March, 1859.

Not S. tubiporoides (Yandell and Shumard), nor of M. Edwards and J. Haime. Polypiers fossiles des terrains palæozoiques, p. 292.

Since the publication of this species in the Canadian Journal in March last, Professor Dana, of New Haven, has informed me that the true S. tubiporoides is a much larger form, and is supposed to be an Eridophyllum. I thought I could identify ours by the description given in the work of Edwards and Haime, but it now appears quite certain that it is not the same'; and also that their fossil cannot be the S. tubiporoides of Yandell and Shumard. In order, therefore, to avoid confusion, I propose to change the name of this species to S. Maclurei.

In my description, the corallites are said to have a diameter of about one line and a half; but, after examining other specimens, I find that in the greater number it is more nearly one line. In some of the colonies, many of the tubes are full one line and one-third in thickness, and it was upon these my first statement was founded.

Sometimes the groups are exceedingly irregular, the corallites widely separated and straggling through the rock.

FAVOSITES TURBINATA. FAVOBITES TURBINATA (Billings.) Canadian Journal, March, 1859.

The description of this species was published in the Canadian Journal for March, 1859. At that time the only specimens I had seen were from the Corniferous Limestone, but we have now several from the Hamilton Group. The species differs from all other Favo. sites known, in its peculiar mode of growth. The form resembles that of a large cyathophylloid coral,--turbinate, the base or smaller

pointed extremity usually curved, but occasionally straight; more or less rapidly expanding upwards ; sometimes so much elongated as to become irregularly cylindrical ; several inches in diameter, and (though rarely) two feet in length. The more common length is from two to six inches. But the most remarkable character is, that

[graphic][merged small][merged small][merged small]

the whole surface, except the larger end, is covered with a thick epitheca, which completely closes all the tubes. In general, the substance of the epitheca only fills the mouth of the tube, but leaves the walls so far visible that the polygonal form of the cells can be distinctly seen. In such specimens, the disc which closes the mouth of the corallites sometimes retains the impressions of the radiating septa, and thus presents an obscurely stellate appearance. There are some with an epitheca so thick, that it not only fills the cells but also entirely conceals the walls, so that the whole mass exhibits an uniformly smooth surfrace.

In the original description, the corallites are said to be usually somewhat less than a line in width.” In one of the specimens from the Hamilton Group, the cells are, upon an average, full one line in diameter, with here and there one nearly a line and a half wide ; and no doubt others will be found still larger, for in all the species of Favosites this character is somewhat variable. The description, therefore, should state that the cells are about one line in width, a little more or less. This species is now known to occur in the Oriskany Sandstone, the Corniferous Limestone, and in the Hamilton Shales. I have ascertained that there are one, two, or three rows of pores ; usually two.

F. GOTHLANDICA and F. HEMISPHERICA. Both of these species occur in the Hamilton Group, at Bosanquet; the former in dome-shaped masses, from three inches to a yard in diameter, with cells about one line and a half wide: the latter in somewhat flat, undulating expansions, from three inches to one foot or more in width, and from less than one to three inches in thickness. In some specimens of the latter, the cells are half a line wide, or thereabouts, and of an uniform size all over the whole surface ; but in others there are numerous spots where the cells are only one-fourth of a line in width. In this respect the specimens from the Hamilton Group agree exactly with those of the Corniferous Limestone.

[merged small][graphic][merged small][merged small]

Description.—Corallum forming large masses of parallel nearly straight cylindrical stems, in contact with each other, or nearly so, and which, when full grown, are from six to eight lines in diameter. The young stems are added by lateral or marginal gemmation, and are at first two or three lines in diameter, their adult size being attained at the length of two or three inches. At the diameter of four or five lines, there are between thirty and thirty-five radiating septa ; at six or eight lines, usually about fifty ; but occasionally in those of the larger size, from seventy-five to eighty may be seen.

Fifty appears to be the common number. There are two or three transverse diaphragms in one line. In most of the corallites there is a central area, one line or a little less in diameter, into which the radiating septa do not penetrate. Others in the same mass seem to be without this central area. Surface with a somewhat thick epitheca, which, where perfectly preserved, is beautifully ornamented with fine crowded, encircling striæ, from fifteen to twenty in the width of one line. In addition to these fine striæ, there are numerous usually sharp-edged annulations, varying from less than one. fourth of a line in width and depth, to one or two lines. Some of the corallites exhibit sudden constrictions of growth, which give to them the appearance of a series of short turbinate stems inserted into each other.

The epitheca is often entirely or partially worn away, and the fine striæ can only be seen when the surface is in a very perfect state of preservation.

It is probable this coral occurs simple as well as aggregate.

Variety.--A fragment from Lot No. 2, Con. 4, Townsend, three inches and a half in length and seven lines in diameter, and with about fifty radiating septa, appears to belong to this species, but differs in having the surface with only five encircling striæ to one line. Resembles Cyathophyllum cespitosum (Goldfuss); but that is a smoother species, and, according to McCoy, only four or five lines in diameter;

Locality and formation.--Lot 25, Con. 5, Bosanquet. Hamilton Shales.

Collectors.--A, Murray, J. Richardson.



Fig. 10. Fig. 9. Heliophyllum exiguum.-Side view. Fig. 10. The same. View of the cup.

Description.--Small, turbinate, more or less curved, often flattened on the side of the convex curvature, radiating septa between sixty and eighty ; about six obscure arched striæ to one line on their flat sides, and the same number of spines on their edges. The depth of

the cup is equal to one-fourth or one-third of the whole length of the coral. In small specimens, the margin of the cup is thin and sharp; but in the large ones rounded, and one line or a little more in thickness. About one-half of the radiating septa reach the centre, and form a small rounded elevation on the bottom of the cup. There is a septal fossette on one side, which, in all the specimens I have seen, reaches the centre. The surface exhibits a few sharp constrictions of growth, with rounded annulations between them, the latter often abruptly terminated on their upper sides. In very perfect specimens, fine encircling striæ of variable size, apparently from eight to fifteen in the width of one line. The horizontal striæ, which indicate the number of the septa, are distinctly visible, but not strongly marked. The position of the septal fossette is indicated on the outside of the cup by two septal ridges, which extend the whole length of the coral, and constitute one of the lines along which the younger septa were added from time to time.

The greater number of the specimens are from six to nine lines in length, but some are full one inch. The width of the cup is always a little less than the length of the entire fossil. The most common number of septa is sixty. The arched striæ and spines are not often preserved.

Locality and formation.-Rama's Farm, near Port Colborne. Corniferous Limestone. Collector.-E. Billings.



Fig. 11. Fig. 11. Cyathophyllum Zenkeri.-Side view of a large specimen. Description.—Corallum simple, turbinate, strongly curved at the pointed base, gently and uniformly arched above, gradually enlarging

« EelmineJätka »