156 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Acmaea rosacea Carpenter, 1866 
American Journal of Conchology, 2:341. Tryon and Pilsbry, Manual of Conchology, 
13: PI. 7, figs. 71-73. 
A. t. parva, conica, tenui, laevi; t. jun. pallide rosacea, elegantissime 
maculis albis et fuscis subradiantim sparsis; t. adulta strigis fusco-rosaceis 
et albidis picta; apice elevato, parum antico; intus rosacea. Long., .2; lat., 
.16; alt., .08 poll. (Carpenter.) 
Shell small, conical, thin, smooth or with very obsolete ribs. The young 
are pale roseate, with few white and brown subradiating spots; the adults 
have rosy brown and whitish streaks or are dotted with pale rose. Apex 
elevated, a little anterior; inside white or rosy. (Tryon and Pilsbry, Man¬ 
ual of Conchology.) 
Type in ? Type locality, San Diego, California. 
Range. Neah Bay, Washington, to Acapulco, Mexico. 
Acmaea instabilis Gould, 1846 
Plate 94, figs. 1, 2 
Proceedings of the Boston Society of Natural History, 2 : 150 . Tryon and Pilsbry, 
Manual of Conchology, 13: PI. 6, figs. 32, 33. 
Testa olivaceo-cervina, elongata, elevata, ad latera compressa, creber- 
rime radiatim striata, apice sub-centrali, obtusa, castanea: apertura ob- 
longo-elliptica; margine integro: facies interna lactea. (Gould.) 
Shell narrow and oblong, the basal margin elevated at the ends; tex¬ 
ture thin ; slopes convex or bulging. Surface finely radiately striated; dark 
brown or black. Inside white or bluish, with or without a faint brown 
spot in the cavity. Largest specimen measures V/ 2 inches in length by % 
in breadth. (Tryon and Pilsbry, Manual of Conchology.) 
Type in State Museum, Albany, No. 6356. Type locality, Neah Bay, 
Washington. 
Range. Kodiak Island to San Pedro, California. 
Described as Patella instabilis. 
Acmaea incessa Hinds, 1842 
Annals and Magazine of Natural History, 10:82; PI. 6, fig. 3. 
Testa conica, ovali, fusca, tenue transversim striata, intus alba; apice 
maculis albis ornato. 
A small, horny, brown shell, remarkable for the white markings on the 
apex, usually three, but sometimes four in number, the central being rather 
the larger. It was always found imbedded in the fronds of a Laminaria, 
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