A monograph of the molluscan fauna of the Orthaulax pugnax zone of the Oligocene of Tampa, Florida

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Govt. Print. Off., 1915 - Mollusks, Fossil - 173 pages
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Page 227 - The date of publication is printed on each paper, and these dates are also recorded in the table of contents of the volumes. The Bulletins, the first of which was issued in 1875, consist of a series of separate publications comprising chiefly monographs of large zoological groups and other general systematic treatises (occasionally in several volumes), faunal works, reports of expeditions, and catalogues of type-specimens, special collections, etc. The majority of the volumes are octavos, but a quarto...
Page 195 - ... to the axial ribs the whorls are marked by four equal and equally spaced slender spiral cords, which are a little less strong than the ribs, and render the junction with these nodulous. Sutures channeled; periphery and base of the last whorl well rounded, the latter marked by six equal spiral cords, which are about as wide as the spaces that separate them. The impressed grooves are crossed by numerous slender axial threads. Aperture ovate; posterior angle obtuse; outer lip thin, pinched in in...
Page 84 - Nuclear whorls, at least two, deeply, obliquely immersed in the first of the succeeding turns, above which the tilted edge of the last volution projects.
Page 161 - ... parietal wall covered with a thick callus, which renders the peritreme complete. The type and another specimen, Cat.
Page 125 - Base of the last whorl well rounded, marked by five spiral cords, which grow successively a little weaker from the periphery to the umbilical area. The spaces between these cords are marked by slender spiral threads, which correspond to the ribs on the spire. Aperture oval, posterior angle...
Page 125 - Shell elongate-come, white. Nuclear whorls two, well rounded, smooth. Postnuclear whorls well rounded, marked by almost vertical narrow axial ribs which are about one-half as wide as the spaces that separate them. Of these ribs 12 occur upon the first, 18 upon the second to fourth, 20 upon the fifth, 22 upon the sixth, and 26 upon the penultimate whorl. In addition to the axial ribs the whorls are marked by equal and equally spaced spiral cords which are almost as strong on the ribs, the junctions...
Page 71 - ... anterior portion. The spaces between the spiral cords on spire and base are marked by slender axial threads. Aperture oval, effuse anteriorly; posterior angle acute; outer lip thin, showing the external sculpture within, rendered wavy by the keels; columella stout, reflected, reenforced by the base, provided with a weak fold at its insertion; parietal wall glazed with a faint callus. The type (Cat. no. 161625, USNM) was collected at Cape St. Lucas, Lower California. It has eight post-nuclear...
Page 70 - ... little distance posterior to the summit of the succeeding whorl, thus leaving a rather broad, plain band above the suture in each turn. Sutures strongly constricted. Periphery of the last whorl well rounded. Base short, well rounded. Entire surface of spire and base marked by very fine, closely spaced, spiral striations. Aperture subquadrate. Posterior angle obtuse, outer lip thin, showing the external markings within, columella slender, well curved and slightly revolute.
Page 73 - Suture strongly constricted. Periphery of the last whorl well rounded. Base moderately long, well rounded, marked by seven equally spaced spiral threads, of which the seventh immediately behind the inner lip is feeble.
Page 122 - ALFREDENSIS, new species. Plate 21, fig. 8. Shell elongate-conic, white. The nucleus consists of a single turn which appears to be smooth. The succeeding turn is well rounded, the next, strongly shouldered on the middle, while the last is slightly concave immediately below the suture, and the rest well rounded. The second whorl is marked with six slender spiral cords, which are about as wide as the spaces that separate them. On the following turn a broad cord appears at the appressed summit and four...

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