Natural History of New York ...: pt.i-viD. Appleton & Company and Wiley & Putnam, 1884 |
Otras ediciones - Ver todas
Natural History of New York ...: pt.i-vi New York (State). Natural History Survey Vista completa - 1885 |
Natural History of New York ...: pt.i-vi New York (State). Natural History Survey Vista completa - 1883 |
Términos y frases comunes
abruptly recurved acute angle Alleghany county angular basal margin beak byssal depression byssal sinus Canandaigua lake cardinal line Cattaraugus county Cayuga lake Chemung group concentric striæ convex curving defined directed forward elevated extended extremity acute fasciculate FLABELLA form and surface Formation and locality Fultonham gibbous HALL Hamilton group height hinge Hinge-line straight imperfect left valve Interior unknown joining the body lamellæ lamellose large left valve left valve showing less ligamental area LYRIOPECTEN margin concave margin oblique margins regularly rounded muscular impression MYTILARCA N. Y. AVICULOPECTEN N. Y. Fig N. Y. LEPTODESMA N. Y. PTERINOPECTEN narrow pallial line Plates and Explanations post-basal posterior ear posterior extremity posterior margin prominent PTERINEA PTYCHOPTERIA radii rays Right valve unknown rounded rays Schoharie shales showing the form Skaneateles lake slope small left valve striæ of growth sub-rhomboidal subtending an acute sulcus surface characters surface markings Tioga county triangular umbo undulations
Pasajes populares
Página 174 - of small or medium size, sub-rhomboidal; body ovate, very oblique; length greater than the height; anterior and basal margins broadly rounded; posterior margin extended and abruptly recurved. Valves equally convex above. Right valve somewhat depressed below, comparatively higher than the left. Hinge-line straight, longer than the length of the shell. Beaks sub-anterior, obtuse, nearly erect, prominent. Umbonal region
Página 174 - large, triangular, joining the body of the valve near the posterior extremity, defined by the crowding and curving of the concentric striae ; margin nearly straight for five-sixths of its extent, then acutely recurving; extremity prolonged into a mucronate spine which extends beyond the posterior limit of the valve. In the right valve the wing is less deeply sinuate. Test thin, marked by closely arranged concentric
Página 175 - which at irregular intervals are crowded into fascicles, producing a gently undulated surface. On the wing the striae are closely arranged, and just below the hinge-line are turned backward along the
Página 257 - SHELL large ; body ovate, erect, wide posteriorly and acute above ; length about one-fifth greater than the height; ventral margin for nearly half the length of the shell nearly direct,
Página 174 - oblique. The anterior extremity is scarcely alate or auriculate, consisting of a rounded extension, straight above and slightly sinuate at the base. Wing
Página 2 - .and the absence of strong radiating lines of ornamentation. Test thin, marked by numerous regular alternating rays, which increase in number by interstitial additions, and become broader and stronger towards the margins. These radiating ribs are crossed by very fine, sharp
Página 112 - which (in good specimens) are produced into subtubular, spiniform extensions upon the rays. Lines of growth are seen between the
Página 152 - Posterior muscular impression situated near the middle of the posterior slope, and marked by irregular vascular striae ; from the lower anterior side of this impression the pallia! line extends slightly downward, curving forward, and continuing in a line nearly parallel to the margin it terminates in a small muscular impression within the rostral cavity. The
Página 249 - the right valve is usually more closely and less strongly marked by them than the left. The radii are crossed and crenulated by elevated, lamellose, concentric striae, which are more distant and conspicuous on the right valve. In the young shells, the radii are conspicuous on the wing; they are a little more distant
Página 93 - SHELL large; broad or narrow ovate, oblique, rarely erect; length from twothirds to nearly equal the height; and in some extravagant forms the height is about double the length; the greatest length below the middle; anterior and basal margins regularly curved; the posterior margin from a little above the base, follows a nearly straight line to the beak. Left valve more or less convex, often gibbous and arcuate. Right valve