CLASS GASTROPODA 
53 
twist; aperture circular, often with a series of internal concentric lamellae 
as if the animal had attempted to contract the opening by secreting a 
succession of smaller tubes within it; sculpture irregular; apart from 
incremental lines, there is a longitudinal, irregular, but tolerably smooth 
ridge on the middle of the exposed whorl with strong wrinkles at right 
angles to it on each side but not crossing it. At resting stages there are 
sometimes angular projections of the margin of the temporary aperture; 
the wrinkles are sometimes reticulated by longitudinal subequal threads, 
which may be entirely wanting on other parts of the same individual; the 
erect portion is nearly smooth except for lines of growth; the color is a 
pale, ferruginous brown. Length of the coiled portion may be about 16; 
of the erect part, 27; the tube with a diameter at the aperture of 2.3 mm. 
There is one internal basal lamella and a smaller one projecting from the 
axial wall at about right angles to and a little above the former. (Dali.) 
Type in United States National Museum, No. 123035. Type locality, 
U.S.S. “Albatross” Station 3368, near Cocos Island. 
Range. Puget Sound to Panama. 
Petaloconchus montereyensis Dali, 1919 
Proceedings of the Biological Society of Washington, 32:250. 
Shell yellowish white, closely irregularly loosely coiled, occurring in 
masses, the sculpture of crowded concentric wrinkles with, on the earlier 
part of the shell, an occasional obscure longitudinal ridge; the internal 
lamellae occur only in the earlier coils, the later portion shows no traces 
of them. Maximum diameter at the aperture, 2 mm. (Dali.) 
Type in United States National Museum, No. 334650. Type locality, 
Monterey, California. 
Range. Known only from type locality. 
Family TURRITELLIDAE 
Genus TURRITELLA Lamarck, 1799 
Shell elongated, many-whorled, whorls rounded with revolving striae; 
aperture rounded. Operculum many-whorled, with a fimbriated margin. 
The shells are usually brown, with red-brown spots or flames. (Tryon, 
Structural and Systematic Conchology.) 
Type. Turritella terebra Linnaeus. 
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