Description
Author: Jan Delsing
Text ID: 127772
Text Type: 1
Page: 0
Created: 2023-08-22 14:42:03 - User Delsing Jan
Language: EN
Text function: [[t:587835,textblock=127772,elang=EN;Description]]
As Turritella stimpsoni Bartsch, 1915:
Shell very elongate-conic, yellowish white, streaked at irregular intervals with light brown. Nuclear whorls 1,75 well rounded, smooth. Postnuclear whorls appressed at the summit, halving two very strong spiral cords, the first of which is on the middle of the whorl, while the second is half way between this and the suture. A third slender thread is situated half way between the two cords and the suture. The portion of the shell between the summit and the first spiral keel forms a slightly concave shoulder, while the space between the two keels forms a deep, broad, concave channel, the space between the second keel and the suture being likewise somewhat concave. In addition to the above sculpture, the entire surface of the spire is marked with fine incremental lines and very fine, closely spaced, spiral striations. Periphery of the last whorl well angulated by a spiral cord which is a little less strong than those occurring on the spire. Base short, almost flattened, marked with lines of growth and exceedingly fine, spiral striations. Aperture irregular, subquadrate, somewhat effuse at the junction of the basal wall with the outer lip; posterior angle obtuse; outer lip very thin, rendered sinuous by the external sculpture, which is shown within by transmitted light; columella very slender, decidedly curved, and slightly reflected over and appressed to the base; parietal wall covered with a thin callus.
The typo and seven additional specimens, Cat. No. 193, U.S.N.M., were collected by William Stimpson on the North Pacific Exploring Expedition at Simons Bay. The type has 14,5 whorls, and measures: Length, 20.5 mm.; diameter, 5.8 mm.
Bartsch, P., 1915. Report on the Turton Collection of South African marine mollusks, with additional notes on other South African shells contained in the United States National Museum.