Popis
Autor: Jan Delsing
Text ID: 85548
Text Type: 1
Page: 0
Založeno: 28.08.2016 12:00:45 - Uživatel Delsing Jan
Poslední změna: 28.08.2016 12:02:40 - Uživatel Delsing Jan
Language: EN
Odkazová funkce: [[t:596494,textblock=85548,elang=EN;Popis]]
Shell rather small, stout, solid, chalky under an olivaceous periostracum; the spire longer than the aperture; whorls at least eight in the adult but usually much eroded; summit of the spire apparently blunt, the whorls in the young short in their axial dimension, giving a "chunky" aspect to the shell; early whorls with two beaded spiral series or cordons, one at the posterior suture, and another, larger, near the anterior suture. Between them is the anal fasciole; as the shell grows the anterior beaded cordon becomes situated nearer the center of the exposed whorl and (on the fourth whorl about twenty) the nodulations represent the posterior terminations of narrow very protractive axial riblets, which on the fifth whorl fade out on the base; the anal fasciole is conspicuously marked with arcuate, close, fine ripples; in front of the shoulder in the young the whole base of the shell and canal are covered with close, fine, spiral threads, which, as the shell grows older, appear also on the anal fasciole; on the other hand, in the older shells the nodular band next the suture and that at the periphery become less prominently sculptured and the ribs almost obsolete; aperture and canal short and wide; pillar with little callus, straight, solid; outer lip produced, thin, sharp, simple; anal sulcus wide, shallow, in the older shells nearly reaching the suture. Length of shell, about 18; of last whorl, 11.5; of aperture, 8; maximum diameter, 7 mm. (Dall.)
NOT FIGURED
Source: Oldroyd, I.S. 1927 . The Marine Shells of the West Coast of North America. Volume IIa