. The Conchologists' exchange. Mollusks. 102 THE NAUTILUS. radial costae ; near the deep radial sulcus the crenulations are want- ing, and beyond the sulcus are merely concentric undulations or growth lines, callum smooth, line of attachment rounded, cordate ; protoplax arrow-shaped with a medial depression and oblique strise. Length, Fig. 1. Fig. 2. Fig. 3. Connecticut to the West Indies. Near New Haven, Ct., in oyster shells (Perkins); Holly Beach, N. J. (Ford); Oceanus, Fla. (White), and found by the writer at St. Augustine. Subgenus Diplothyra Tryon, 1862. The protoplax and also the
. The Conchologists' exchange. Mollusks. 102 THE NAUTILUS. radial costae ; near the deep radial sulcus the crenulations are want- ing, and beyond the sulcus are merely concentric undulations or growth lines, callum smooth, line of attachment rounded, cordate ; protoplax arrow-shaped with a medial depression and oblique strise. Length, Fig. 1. Fig. 2. Fig. 3. Connecticut to the West Indies. Near New Haven, Ct., in oyster shells (Perkins); Holly Beach, N. J. (Ford); Oceanus, Fla. (White), and found by the writer at St. Augustine. Subgenus Diplothyra Tryon, 1862. The protoplax and also the metaplax are bordered by an elevated callous margin ; in the former case obliterating the deep depression in front of the umbones. Metaplax and hypoplax divaricating. Tryon considered the sculptured and smooth portions of the protoplax as a " double accessory valve," and on that character founded the genus Diplothyra. The above characters seem to separate it subgenerically from the typical Mai^tesia. Martesia (Diplothyra) carib^a (Orbigny). Fig. 3. Pholas caribcBa Orb., Historia, etc., p. 281, pi. 25, f. 20-21, 1845. French edition, p. 211, t. 25, f. 20-21, 1853. Diplothyra Smithii Tryon, Proc. Acad. Nat, Sci. 1862, p. 450; Mon. Pholadacea, etc., p. 126, pi. —, f. 2, 1862. Shell broadly wedge-siiaped, inflated anteriorly and tapering ab- ruptly towards the posterior ; the anterior half with fine wavy lines forming slight radial costae, radial sulcus quite prominent, [losterior half marked only by small concentric undulations and growth lines;. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Averell, William D. Philadelphia, Wm. D. Averell
Size: 2458px × 1017px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectmollusks, bookyear188
