OF THE UPPER HELDERBERG BRYOZOANS OF THE UPPER HAMILTON GROUPS. BY JAMES HALL, LL.D. [Read, by title, before the Albany Institute, March 29, 1881.] AND The present paper is chiefly devoted to the Bryozoans of the Upper Helderberg and Hamilton Groups.* The descriptions in full were communicated in the Thirty-third Report upon the State Museum of Natural History, in January, 1880, but that document has not yet been printed. The present paper is an abstract of the original, with the descriptions abbreviated to conform to the space at my disposal. The number of species has been greatly increased by a series of specimens from the Falls of the Ohio river, very kindly communicated to me by Victor W. Lyon, Esq., of Jeffersonville, Indiana; and many of the forms cited from that locality are due to him. In this collection we have not only the expanded celluliferous parts, but the bases or radical portions of the fronds, in a great number of examples ; and these serve not only to aid in the determination, but to confirm the specific distinctions adopted. Although unwilling to increase the number of specific designations, the examination of numerous specimens of nearly all the species has left no alternative but to follow the course here adopted. We have within a few years discovered the existence of a silico-calcareous band at the base of the corniferous limestone in western New York and Canada West. This horizon corresponds with that of the Schoharie grit in eastern New York, but the material appears to have been in solution before deposition; the sea-bed, in this condition, affording a most favorable soil for the growth of Bryozoans; the rock now being largely composed of the broken and comminuted fragments, and of larger and more complete portions of these organisms. In the weathered portions of this rock, the original substance of the Bryozoan has been dissolved, leaving a sharp, clean impression preserving the most delicate and minute characters of the fossil. I have here included a few forms of CHATETES, which, from their structure, can scarcely be separated from the FAVOSITIDÆ, while the difference between this genus and TREMATOPORA is hardly determinable by any well marked characters. Under the FENESTELLIDÆ I have not adopted the genus POLYPORA, though describing species with from two to four ranges of cells on the branches. The numerous examples of this variation have rendered the distinction between the genera obsolete; but the question will be more fully discussed in the Report on the State Museum of Natural History. Many of the species known in New York likewise occur in Canada; and further collections will doubtless show that nearly all are common to the two regions. In the more calcareous portions of the formation, the determination of specific characters is attended with great difficulty, and many still remain for future study and decision. The Hamilton Group, in nearly its entire extent, has furnished numerous Bryozoans of varied and interesting forms; which will be given in full in the State Museum Reports; the space allotted to this communication admitting only such as have been studied and arranged to precede the FENESTELLIDE. The descriptions of the latter are however completed, and in the hands of the printer. In the determination of all these forms, as well as in their illustration in numerous excellent figures, I have been greatly indebted to Mr. George B. Simpson, except for whose zeal in the study and careful discrimination of the specific forms, I should, amidst other duties, have left, for the present at least, many of them undetermined and undescribed. CHÆTETES, Fischer. CHETETES CREBRIRAMA, n. sp. Coral ramose, solid; branches frequent, bifurcating, occasionally trifurcating; cells tubular, polygonal, gradually diverging till within .75 mm. of the surface, when they turn more abruptly, opening slightly oblique, diameter at aperture .25 mm., in the interior walls thin, at the surface thickened, the thickness of the walls frequently equal to the diameter of an aperture; tubes septate; septa very thin and fragile, occurring at irregular intervals; on the surface are maculæ distant. from each other from 2.5 mm. to 3 mm., which are sometimes elevated. The maculæ form a prominent feature of the branches. Locality-Falls of the Ohio river, near Louisville, Ky. CHETETES EQUIDISTANS, n. sp. Ramose, solid; branches infrequent, diameter 5 mm.; cells tubular, polygonal, septate; septa strong, near the surface there are four in the space of one mm., in the remaining portion from eleven to thirteen, equidistant; cell-tubes 8 mm. in length, apertures oval, length 5 mm., with spinules at the angles, surface with maculæ of large cell-apertures. Locality-New York. CHETETES EGENUS, n. sp. Ramose; branches infrequent, diameter 5 mm.; cells tubular polygonal, non-septate, walls very thin; apertures very irregular in size and form, frequently hexagonal, length from equal to three times the width, which is usually about 35 mm.; at the angles are frequently strong obtuse spines. Locality-Onondaga Valley, N. Y. CHETETES? (TREMATAPORA ?) INTERNASCENS, n. sp. Ramose, solid; diameter 8 mm. ; cells tubular, polygonal, arising from the center of the Branch, gradually diverging till within one mm. of the surface, when they turn more abruptly outward, frequently ten mm. in length, nearly the entire length angular; apertures circular or oval, diameter .33 mm., contiguous, oblique, subimbricating; on one side of the aperture the cell-wall projects above the surface .17 mm.; maculæ at irregular distances, centers noncelluliferous; tubes septate; exterior of cell-wall transversely corrugated. Locality - Falls of the Ohio river. TREMATAPORA, Hall. TREMATOPORA ARBOREA, 2. sp. Ramose, solid; branches frequent, diameter 2.50 mm.; cells tubular, polygonal; apertures oval; cells septate; septa occurring at irregular intervals; length of apertures .22 mm., width two-thirds the length, usually irregularly arranged, but sometimes occurring in transverse oblique rows, distance variable; the margins of apertures and intervening space have numerous minute spines, from six to eight, sur. rounding an aperture; no maculæ. Locality Falls of the Ohio river. TREMATOPORA? ANNULATA, n. sp. Ramose, solid; branches occurring at intervals of from 4 to 15 mm., diverging at an angle of 45°; diameter three mm.; cells tubular, regularly curving to the surface, diameter at aperture 25 mm., polygonal, walls thin, sometimes thickening at the surface constricting the cellapertures; cells septate; septa closely arranged; sometimes angular pits occupy the intercellular space of the surface, apertures irregularly arranged, with small spines at the angles, giving to the surface an aculeate appearance; at intervals of two mm. occur elongated elevations at right angles to the branch, two or more elevations being on a line and giving to the branch an annulated appearance; a narrow space along the middle of the elevations without apertures, but frequently with small pits. This species can be easily distinguished by its strong annulations. Locality-Falls of the Ohio river. TREMATOPORA ANNULATA, VAR. PRONASPINA, n. var. Ramose; branches infrequent, diameter two mm.; cells tubular, polygonal, gradually diverging, diameter of aperture .25 mm. ; cell-walls of the interior thin, thickened at the surface; cells septate; septa occurring at irregular intervals; width of aperture greater than the length, subimbricating; at the base of each aperture a strong oblique spine, which feature distinguishes it from the ordinary forms of T. annulata. Locality-Falls of the Ohio river. TREMATOPORA ALTERNATA, n. sp. Ramose, solid; branches infrequent, diameter slightly more than one mm.; cells tubular, cylindrical, opening directly outward; apertures oval, length .38 mm. width two-thirds the length, margins thin, scarcely elevated, arranged in longitudinal parallel rows; fifteen in the space of five mm., five or six rows on a branch, apertures alternating, forming oblique, transverse longitudinal rows, separated by strong granulose ridges; at the base of each aperture is a strong conical node. The most prominent feature of the surface is the longitudinal ridges alternating with the rows of nodes. Locality-Onondaga Valley, N. Y. TREMATOPORA RECTILINEA, n. sp. Ramose, solid; diameter 1.20 mm.; cells tubular, cylindrical, apertures oval, arranged in parallel longitudinal rows, fourteen rows on a branch, alternating-forming equally prominent oblique rows; space between apertures equal to width of aperture; space between longitudinal rows elevated or striated, granulose; at the base of each aperture there is a strong conical node. Locality-Onondaga Valley, N. Y. TREMATOPORA SCUTULATA, n. sp. Ramose, solid; branches occurring at intervals of from 5 to 12 mm., diameter one mm.; cells tubular, apertures rhombiform, length .33, width 25 mm., closely arranged in oblique parallel rows at an angle of 45° to the axis of the branch, separated only by the cell-walls; the margins are minutely granulose, and at each angle is a strong node. Locality-New York. CALLOPORA, Hall. 1 CALLOPORA IRREGULARIS, n. sp. Ramose, hollow; diameter of branch three mm., thickness of the bryozoum .55 mm.; inner surface a wrinkled epitheca; cells tubular, opening directly outward; apertures circular, diameter from .25 to .33 mm., irregularly disposed; the surface has maculæ destitute of apertures, from 1 to 1.5 mm. in diameter; apertures nearest the maculæ slightly larger than the others, margins strongly and equally elevated, intermediate space sometimes with shallow angular pits. Locality-New York. CALLOPORA ACULEOLATA, n. sp. Ramose; diameter of branches two mm.; cells opening directly outward; apertures circular or nearly circular, length .45 mm., distance between varying from contiguity to .25 mm.; margins strong and distinctly elevated, and having from one to three comparatively strong nodes; intermediate space occupied by minute angular pits, usually one or two series between two adjacent apertures. CALLOPORA MULTISERIATA, n. sp. Ramose, solid; branches diverging at an angle of 80°, diameter two mm.; cells tubular, cylindrical; apertures oval, length .33 mm., irregularly disposed; margins thin, not elevated, intermediate space with. minute angular pits arranged in longitudinal rows giving a striated appearance to the surface; from 5 to 10 series between adjacent aper tures. Locality-Warner's Quarry, south of Leroy, Genesee county, N. Y. LICHENALIA, Hall. LICHENALIA SUBSTELLATA, n. sp. Lamellose expansions, free or encrusting, or forming masses by superimposition; each layer usually one mm. in thickness: cells tubular, varying in length from .25 to 4 mm.; apertures usually circular, diameter .28 mm., closely and irregularly arranged; surface with maculæ, usually elevated, the centers with out apertures; cells radiating from maculæ larger and more oblique than the others; apertures variable, sometimes opening directly outward, margins equally elevated, but usually oblique; margins unequally elevated, occasionally very oblique and imbricating, the most strongly elevated portion produced and spiniform, sometimes bidenticulated; cell-tubes septate, eight septa in space of one mm.; frequently contorted. Locality Falls of the Ohio river. LICHENALIA DENTICULATA, n. sp. Lamellose expansions, or massive by superimposition of layers; cells tubular, diameter .23 mm., one-half of the margin is very |