Box 14, Folder 3: Coal 1861

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GENUS CYPRICARDITES, Conrad; CYRTODON AND VANUXEMIA, BILLINGS; PALAEARCA, HALL

CYPRICARDITES ROTUNDATUS, (n.s.) [vol1/38?]

Description. Shell sub-globose, height and width nearly equa and thickness about four-fifths as great as the height from beak to base; beaks slightly incurved, cardinal line curved, front rounded, surface smooth or marked by obscure concentric lines of growth. The interior of the hinge plates marked by two lateral teeth and about four oblique cardinal teeth, Anterior muscular impression of moderate size, distinct on the anterior end.

Length three-fourths to one inch; greatest height a little more than the length.

Geological Formation and Locality. Trenton group, (Buff limestone), Beloit, Wisconsin.

Prof Nason, Mr. E. Hobart, T.J Hale, James Hall.

CYPRICARDITES NIOTA. (n.s.) [vol1/38?]

Description. Shell broadly sub-ovate, broadest at the posterior end; umbones very gibbous; beaks incurved, little elevated, situated about one-fourth of the length of the shell from the anterior end. Cardinal line straight or little curved; anterior, posterior and basal margins rounded.

Anterior muscular impression situated near to the cardinal line, well defined; posterior imprint obscure. Surface of the shell marked by concentric lines of growth.

This species differs from C. rotundata in being more oblique, in the straighter cardinal line, and less ventricose form. It is intermediate between that species and C. venntricosa, from which it differs in the less obliquity and the greater length from beak to base.

Length one inch and a quarter, hight one inch.

Geological Formation and Locality. In Trenton limestone, (Buff limestone), Beloit and Chaupierre, Wisconsin.

Prof. Nason, Mr. Hobart, T.J. Hale, Jas. Hall.

CYPRICARDITES RECTIROSTRIS, (n.s.)

Description. Shell somewhat elongate-ovate, gibbous in old specimens, young individuals moderately convex; beaks elevated, distant, scarcely incurved; hinge line but little curved; anterior end short, posterior end forming the greatest length of the shell; basal margin [margin] making nearly a semicircular curve. In

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terior (as shown in casts,) with strongly marked muscular imprints; the anterior one having its cardinal margin excavated out of the hinge plate, not deeply seated, somewhat reniform; the posterior imprint situated at near half its diameter below, extremities of the lateral teeth irregularly oval; pallial impressions usually distinctly marked, sometimes bounded by an elevated ridge, in casts, showing a depression in the shell. Lateral teeth situated obliquely to the hinge line, four in number, cardinal teeth several, the precise number not determined. cavity of the beaks deep. External surface of shell unknown. Length from one and a quarter inches to two inches, height from summit of beaks to base greater than the length.

This species differs conspicuously from all others except P. rotundata in the highly elevated and nearly straight beaks; and from that species in the proportionally greater distance from the beaks to the base of the shell, and the less rounded outline. The beaks of that species are much more curved than in this.

Geological Formation and Locality. Trenton limestone group, (Buff limestone) ; at Janesville, Wisconsin, and near Dubuque Iowa.

Collectors Dr. Thomas Scott, T.J. Hale, James Hall.

GENUS MODIOLOPSIS, HALL.

MODIOLOPSIS PLANUS (n.s)

Description. Shell, small compressed, the length a little greater than the breadth, wider posteriorly. Cardinal line straight from the beaks to the posterior end, having a sub-alate appearance; somewhat narrowly rounded anteriorly, the basal margin straight, or but little curved, except at the anterior end. Posterior end obliquely truncate. Beaks small, but little or not at all incurved; umbonal slope moderately prominent, and sub-angular. In the casts, the anterior muscular impression is distinctly double, and well marked, the upper one situated close to the cardinal border; the posterior impression is larger and double, but less distinct, situated about two-thirds the distance from the beaks to the posterior margin; pallial line entire and somewhat distinctly marked.

Surface marked by strong concentric lines of growth. Length about three-fourths of an inch.

The species resembles the M. subspatulatus more than any other species known to me, but is much more oblique, has a proportionally longer hinge line, is more slate, and the umbonal slope continues to the junction of the basal and posterior

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margins. The truncation of the posterior end is a feature which will at once distinguish it from the species.

Geological Formation and Locality. In the Trenton limestone group (Buff limestone); at Beloit, Wisconsin.

MODIOLOPSIS? SUPERBUS, (n.s.)

Description. Shell large elongate, sub-elliptical in outline; cardinal line very slightly curving throughout its entire length, and reaching no more than half the distance from the beaks to the posterior extremity of the shell. The posterior margin from its junction with the hinge line, is but little curved till near the extremity of the shell, where it is abruptly rounded to the base line, which is gently arcuate throughout its entire length except a slight sinuosity caused by a gentle depression extending obliquely from the anterior side of the beaks to the to the basal margin a little behind the beaks, anterior and narrow and abruptly rounded. Beaks moderately elevated, gently incurved and approximate, situated about one-sixth of the entire length of the shell from the anterior end; a strong rounded or sub-angular umbonal ridge extends from the beaks to the postero-basal extremity of the shell, becoming more gently rounded as it recedes from the beaks.

Surface marked by strong concentric undulations, parallel to the lines of growth.

This is a large and fine species, equaling the M. modiolaris in size, but possessing some peculiarities which makes the propriety of its reference to the genus doubtful.

Geological Formation and Locality. In limestone of the age of the Trenton limestone (Buff limestone), Beloit, Wisconsin.

GENUS AMBONYCHIS, HALL.

AMBONYCHIA IAMELLOSA, (n.s.)

Description. Shell obliquely sub-ovate in outline, with ventricose valves, becoming compressed and attenuate towards the extremity of the hinge line. Beaks slender, pointed and directed forwards. Hinge line straight, a little less than the greatest width of the shell. Anterior margin rather deeply impressed in the upper part, and in some specimens showing a shallow sinus, making what appears to have been a byssal opening, the lower part is regularly rounded into the basal margin. The posterior end is somewhat squarely truncate from the extremity of the hinge line and gradually curving below.

Surface marked by numerous strong concentric flattened

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lamellose ridges, without visible radiating striæ in the partially exfoliated shell.

On casts, the large muscular impression is of a circular form, and is situated on the posterior side of the shell at about half its diameter below the hinge line, leaving a distinct depression reaching nearly to the beak, from its advancing with the growth of the shell.

This species is easily distinguished from any other known to me, by its form and lemellose surface, which is not strongly ridged as in the A. undata of the Trenton limestone in New York.

Geological Formation and Locality. In the Trenton limestone group at Mineral Point, and opposite to Dubuque, in Wisconsin. Collector. T. J. Hale, James Hall.

AMBONYCHIA PLANISTRIATA, (n. s.)

Description. Shell obliquely sub-ovate, with moderately convex valves, most convex a little anterior to the centre; the anterior side full and rounded, less ventricose posteriorly. Hinge line straight, less than the greatest width of the shell. Anterior and posterior margins broadly rounded. Beaks strong, projecting above the hinge and slightly incurved.

Surface marked by distant concentric undulations, any by moderately fine radiating striæ, which are flattened and have very narrow interspaces.

This species differs from the preceding in the less obliquity of the valves in the shorter hinge line and in the radiating striæ. It is more nearly related to A. orbicularis, of the New York rocks, but it is a little more oblique, less extended anteriorly, not so ventricose and the radiating striæ are stronger.

Geological Formation and Locality. In limestone of the age of the Trenton limestone of New York, at Mineral Point and Beloit, Wisconsin.

Collector. Prof. Daniels, T. J. Hale.

AMBONYCHIA ERECTA, (n. s.)

Description. Shell sub-quadrangular in outline with convex valves, hinge line straight, as long as the greatest width of the shell, forming a little less than a right angle with the anterior border. Posterior slope nearly parallel with the anterior. Basil margin strongly rounded. Beaks in the casts, small, abruptly attenuate, projecting little above the hinge line.

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Surface (as indicated in casts,) marked by concentric undulations only.

This species differs from the preceding in the more quandrangular form and erect position of the beaks.

Geological Formation and Locality. In rocks of the age of the Trenton limestone of New York, at Beloit, Wisconsin.

AMBONYCHIA ATTENUATA, (n.s.)

Description. Shell elongate-ovate, widest below the middle; width a little more than two-thirds the length; attenuate at the beaks; ventricose in the middle, regularly arcuate from the beak to the base; hinge line straight, a little more than onethird as long as the greatest length of the shell, and very obtusely pointed and incurved at their extremity. Surface character unknown, except a few undefined concentric undulations upon the casts.

This species, in form, is somewhat like A. bellastriata of the Trenton limestone in New York; but the shell is proportionately more elongated, the anterior side straighter and the umbones and beaks less curved forward.

Geological Formation and Locality. In the Buff limestone, age of Trenton limestone of New York, at Beloit, Wisconsin. Collector. T.J. Hale.

GASTEROPODA

GENUS PLEUROTOMARIA, DE FRANC.

PLEUROTAMARIA NIOTA. (n.s.)

Description. Shell large, broadly sub-conical, the diameter through the last volution equal to about four-fifths of the height, consisting of six volutions, which are flattened on the periphery, with a very slightly concave space upon the upper side, extending to the suture; lower side rounded into the moderately large umbilicus. the last volution large and ventricose.

Surface character unknown, except a few undefined undulation near the extremity of the last volution, which are more distinct below than above.

This species is intermediate in form, between P. subconica and P. bicincta; resembles the first very closely in general outline, except that the volutions are a little too convex above the centre, and the flattening of the periphery is much greater than the narrow carina of the species; and in casts there

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