Reports, Volume 5 |
Other editions - View all
Common terms and phrases
13th Ann Actinocrinus Allorisma aperture Athyris Aviculopecten Batocrinus beak Bellerophon Burlington limestone Capulus carbonarius cardinal Chonetes Conularia convex Cooper county costæ crinoid Dorsal valve Dorycrinus Dyas in Nebraska Edmondia Fenestella figs flattened gasteropod Geinitz genus Geology Iowa Hall Henry county hinge-line Horizon and localities Horizon and localities.-Lower Horizon and localities.-Upper Illinois incurved Indiana John & Worthen Jour Kansas City Kaskaskia Kaskaskia limestone Keokuk limestone Kinderhook lines of growth localities.-Lower Carboniferous localities.-Upper Carboniferous Louis Acad Lower Carboniferous margin McChesney Meek & Worthen mesial Missouri missouriensis Myalina Naticopsis Nautilus Nebraska Norwood & Pratten occidentalis Orthis Orthoceras Phila Plate Platyceras Pleurotomaria Polypora posterior Proc Productus prominent radiating Rhynchonella ridge rounded Saint Louis limestone Shell small Shumard Silurian sinus Soleniscus species specimens spire Spirifer Spirifera Straparollus striæ Surface marked Swallow Terebratula Trans U. S. Geol Ulrich Upper Coal Measures Ventral valve VIII volutions White whorls
Popular passages
Page 61 - ... scarcely equaling that of the other valve, arched at the apex, but not strongly incurved ; area about twice as high as that of the other valve, well defined, tapering rather rapidly toward the lateral extremities, arched with the beak, and directed backward and downward at decidedly less than a right angle to that of the other valve ; foramen broad-triangular, and partly occupied by the cardinal process of the other valve. Interior with muscular scars occupying a rather deep, bilobate impression...
Page 59 - ... appearance to the central and umbonal regions ; beak small, projecting somewhat beyond that of the other valve ; abruptly pointed and rather distinctly arched, but not strongly incurved; area about twice as high as that of the other valve, and with its sharply defined edges sloping to the lateral extremities of the hinge, directed and arched obliquely backward with the beak ; foramen having...
Page 72 - Surface of both valves ornamented by numerous radiating striae, that increase in number, on the ventral valve, mainly by intercalation, and are usually arranged with one to six or eight smaller and shorter ones between each two larger and more prominent ones, the largest one of which often occupies the mesial line; while on the dorsal valve they more frequently increase by division, and are generally of more uniform small size. On well preserved specimens all the radiating lines are crossed by numerous...
Page 120 - ... backward to the faintly sinuous part of the base ; cardinal area unknown ; posterior linear teeth about three; surface ornamented with distinct marks of growth crossed by radiating markings, which on the compressed posterior dorsal region form rather well-defined radiating lines; anteriorly, however, these diminish in size so as to become very minute or scarcely visible, crowded, obsolescent striae. Length, 0.75 inch; height, 0.31 inch; convexity, about 0.30 inch. Professor Geinitz has identified...
Page 71 - Meek 1873, Paleontology of Ohio, Vol. I, page 881. " Shell attaining a large size, semi-oval, the breadth being nearly always greater than the length, but varying from about equal to the latter to the proportions of near nine to seven ; hinge line as long as the breadth of the valves at any point farther forward, or somewhat longer ; lateral extremities rectangular, or a little more or less than rectangular; sometimes compressed and moderately deflected ; lateral margins straight, a little convex,...
Page 98 - ... abruptly pointed, projecting beyond that of the other valve, and rather distinctly arched; but not so closely incurved as to conceal the small fissure, which seems to be closed below by a deltidium, that leaves a minute aperture above, just under, or extending to, the apex ; margin on each side of beak carinated, so as to give the appearance of a kind of false cardinal area. " Surface of each valve ornamented by about 16 to 18 small, simple, radiating plications, of which about three to five...
Page 60 - ... medium size, rather distinctly resupinate, somewhat wider than long, subquadrate in general outline ; moderately convex; cardinal margin shorter than the breadth of the valves, and rounding abruptly at the extremities into the lateral margins, which round and converge forward; front a little sinuous or straightened at the middle. Dorsal valve more convex than the other, its most prominent part being near the middle ; mesial sinus small, and rather shallow, sometimes continued back nearly to the...
Page 115 - Pinna ; cardinal and ventral margins generally nearly straight (the latter being more convex in outline) and converging gradually from behind to the rather obtusely pointed anterior extremity ; posterior side truncated, rounding into the base, and intersecting the posterior extremity of the hinge very nearly at right angles — a little sinuous just below the extremity of the hinge.
Page 58 - Shell small, plano-convex, rather depressed, transversely truncato-suboval, the length being about five sixths its breadth ; hinge line, perhaps, always a little shorter than the greatest breadth of the valves; lateral margins generally rounding to the hinge, most prominent at, or a little behind, the middle, and rounding to the front, which is usually somewhat straightened, or very faintly sinuous at the middle ; or, presents a regular semi-circular outline. "Dorsal valve nearly flat, or slightly...
Page 72 - ... nearly or quite closed by the dental process and pseudo-deltidium of the other valve. Interior with cardinal margin somewhat carinate within ; hinge teeth moderately prominent, remote, and widely divergent ; dental ridges obscure, and extending obliquely outward and forward, but not produced or curving to surround a saucer-shaped cavity for the muscular scars ; scars of adductor muscles narrow, long and closely approximated, or almost in contact ; those of cardinal muscles on each side very large,...