carinate ridges, of which two or three are visible on the upper volutions, and about five on the body-whorl; those on the upper side of the volution more distant than those on the lower side.

SURFACE marked by fine, closely arranged striæ of growth, which are sometimes crowded in fasciculi, giving gentle inequalities; these striæ are directed a little backward from the suture.

The larger specimens are about an inch in diameter, with a height about one-fourth greater. The prevailing forms are about three-fourths of an inch high.

Formations and localities. In the coarse sandy shales of the Hamilton group, in Chenango and Madison counties, N. Y.

CYCLONEMA MULTILIRA.

PLATE XII, FIGS. 30–33.

Cyclonema multilira, HALL. Descriptions of New Species of Fossils, etc., p. 20. 1861.

SHELL turbinate, ventricose. Volutions five or more; body-whorl very large and extremely ventricose, its surface marked by fine concentric striæ of growth, which are directed backwards from the suture toward the periphery, and pass to the lower side of the volution without deviation, except in the slight undulation at the crossing of the revolving carinæ. SURFACE of the volutions marked by strong, elevated, revolving lines or carinæ, of which there are about five or six upon the upper ones, and ten or twelve on the body-whorl; the space from the suture to the upper of these lines is greater than between the lines, those of the periphery being more closely arranged than those above or below.

This species is similar in form to C. lirata, with the last volution more ventricose, and all the volutions less angular; the revolving carinate lines are twice as numerous and not so strong. It is intermediate between the C. Ham

iltonia and C. lirata; being a little more ventricose than either, without the flattened or concave band on the upper side of the volution.

Formation and locality. In the coarse shales of the Hamilton group at Smyrna, Chenango county, N. Y.

CYCLONEMA HAMILTONIÆ.

PLATE XII, FIGS. 34-36.

Cyclonema Hamiltoniæ, HALL. Descriptions of New Species of Fossils, etc., p. 19. 1861.

66

66

66

66

66

66

Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 47, pl. 5, fig. 16 (not 15). 1862.
Illustrations of Devonian Fossils: Gasteropoda, pl. 12. 1876.

SHELL Subglobose-conical; height a little more than the width across the last volution. Volutions four or five; apex minute and gradually expanding to the body-whorl which is somewhat abruptly ventricose, flattened or a little concave for a short distance below the suture, and the space limited on the exterior side by a carina, which is the first of a series, marking the periphery of the volution.

SURFACE marked by extremely fine lamellose lines of growth, which are directed backwards from the suture without bending or curvature in passing the carinations. The volutions, except the narrow concave space above, are marked by strong revolving elevated carinate lines, of which there are from fourteen to eighteen on the body-whorl. These carinæ are usually simple and subequal, more or less distinctly defined, and sometimes alternately stronger and more subdued, or with two finer ones between the stronger. On each of the upper volutions there are three, four or five of these carinæ preserved, and they are distinctly crenulated by the passage of the concentric striæ, which are sometimes also bent forward on approaching the first carination.

This species has nearly the proportions of Pleurotomaria capillaria, except in the more abrupt ventricosity of the body-volution. The flat or concave belt on the upper side of the volution, which is without revolving striæ and marked

only by lines of growth, is a distinguishing feature; and also the absence of elevated concentric striæ and the band upon the periphery.

Formations and locality. In the shales of the Hamilton group, Cazenovia, N. Y.

CYCLONEMA OBSOLETA.

PLATE XII, FIG. 37.

Cyclonema obsoleta, HALL. Illustrations of Devonian Fossils: Gasteropoda, pl. 12. 1876. SHELL Subglobose-conical. Volutions five or more in the entire condition, becoming gradually expanded, and the last very ventricose; the upper volutions marked by fine revolving carinæ, of which there are six or seven on the volution above the last; the carinæ are distinctly crenulated by revolving striæ. The outer volution, so far as preserved, is marked only by fine revolving striæ.

This species has the general aspect of the C. Hamiltonia, and may be only a variety of that species, in which the carinæ have become obsolete on the outer volution. The volution above the body-whorl shows six carinate lines, and partially a seventh. There is a faint indication of the flattened band upon the upper side of the last volution, which, in this specimen, is limited below by a depression or line of fracture.

Formation and locality. In sandstone of the Chemung group, from Southern New York, the particular locality unknown.

Cyclonema concinna, HALL.

CYCLONEMA CONCINNA.

PLATE XII, FIGS. 38-40.

Illustrations of Devonian Fossils: Gasteropoda, pl. 12. 1876.

SHELL subglobose below, conical above; spire rapidly tapering; volutions gradually increasing in size to the last one, which is very ventricose.

The figures are from gutta-percha impressions of the exterior mould left in sandstone. The upper volutions present a double carina on the periphery like

PLEUROTOMARIA. This feature is not observed on the last volution, which is marked on one specimen by a faint carination near the upper part; on the lower side of the volution are four or five revolving carinate bands.

The features preserved are altogether like those of CYCLONEMA, and in the absence of other evidence, it is thus referred.

Formation and locality. In a calcareous band of the Chemung group at Nichols, Tioga county, N. Y.

LOXONEMA, PHILLIPS.

In the Schoharie grit, and in the limestones above this rock, there are numerous casts of spiral univalves, which, though evidently belonging to forms like LOXONEMA or MURCHISONIA, cannot readily be distinguished in the absence of surface markings. Several species of these genera have been described (Fourteenth Report on the N. Y. State Cabinet Nat. Hist.) from specimens. retaining the external characters. There are other forms still, which, although we have no examples with the shells preserved, nevertheless differ so widely in their form and proportions from those already described as to be distinguished by these characters alone.

One of these from the Schoharie grit has nearly the form and proportions of L. attenuata of the Upper Pentamerus limestone, and in the casts no positive means exist of pointing out characters which will distinguish the one from the other. Specimens resembling the L. compacta, of the same geological formation, upon a careful comparison, show the volutions to be more rotund, and the spire more rapidly ascending. The determination of species in this condition is attended with many difficulties, and in the end there must still remain some doubt, when the differences of form and proportions may have been disguised by pressure or accident. Under these circumstances, I have characterized several species among the specimens which are only known in the condition of casts; leaving a more satisfactory determination to the future, and a collection of better specimens.

LOXONEMA? SUBATTENUATA.

PLATE XIII, FIGS. 1-6.

Loxonema? subattenuata, HALL. Descriptions of New Species of Fossils, etc., p. 24. 1861.

SHELL turretiform, elongate; spire somewhat rapidly ascending. Volutions six or more, moderately convex, gradually expanding from the apex, the last one somewhat ventricose towards the aperture.

SURFACE unknown.

A cast of a species having proportions nearly similar to Murchisonia Maia occurs in the Schoharie grit; but the shell has tapered somewhat more rapidly, the volutions are more ascending and less convex, and the form of the aperture is subovate and narrowed below. In one specimen the length from base of aperture to top of the sixth volution is one inch and three-fourths, and the diameter of the last volution is about five-eighths of an inch. A larger individual, referred to the same species, has a length of two and a quarter inches. In this species the volutions are less rapidly ascending, and the spire less attenuate than in L. attenuata of the Lower Helderberg group, which in many respects it resembles.

Formation and locality. In the Schoharie grit at Schoharie, N. Y.

LOXONEMA RObusta.

PLATE XIII, FIGS. 4, 5, 6.

Loxonema robusta, HALL. Descriptions of New Species of Fossils, etc., p. 24. 1861.

SHELL robust, terebriform; spire rapidly ascending. Volutions moderately convex, the last slightly more ventricose, with a diameter of nearly an inch. The length from the base of the aperture to the summit of the fourth volution, in a specimen which has been compressed, is three inches, and in a more rotund specimen the same number of volutions measure a little less than three inches; above this there have probably been three or four volutions to the summit, adding to the length about three-fourths of an inch.