CLASS GASTROPODA 
183 
dum intensiorbus, et livido, varie nebulosa et punctata; anfractu primo 
nucleoso diaphano, granuloso, apice mamillato; dein iv. normalibus, sub- 
tabulatis; primo costibus spiralibus ii. acutis, valde expressis, altera parva 
suturali; anfr. penult, costis iii. quarum media extantior, superior sub- 
granulosa; anfr. ult. aliis intercalantibus, supra peripheriam v. quarum 
tertia magis extans; interstitiis a lineis incrementi vix decussatis; costa 
circa peripheriam angulatam conspicua; basi costulis rotundatis, haud 
extantibus, peripheriam et axim versus conspicuis, medio saepe obsoletis; 
basi nitida, subplanata; apertura subquadrata, intus carneo-nacrea, valde 
splendente: operculo tenuissimo, levissimo, pallido, diaphano, concavo; 
anfr. circ. x. crebris, parum definitis. Long., 0.23; long, spir., 0.15; lat., 
0.24 poll. ( Carpenter.) 
Type in State Collection, Species 530a. Type locality, Monterey, Cali¬ 
fornia. 
Range. Monterey to San Diego, California. 
Calliostoma costatum Martyn, 1784 
Plate 97, figs. 8, 10 
Universal Conchology, Table 1, PI. 34. Tryon and Pilsbry, Manual of Conchology, 
11:362; PI. 16, figs. 6, 9; PI. 18, fig. 16. 
Martyn figured and named but did not describe. 
Shell conical, rounded at periphery, base flattened; imperforate; solid; 
dark chestnut colored, the spiral riblets lighter, apex dark, usually purple. 
Surface encircled by numerous spiral smooth riblets, their interstices 
closely finely obliquely striate; riblets usually seven to nine on the penulti¬ 
mate whorl, about nine on the base. Spire conic; apex acute; sutures 
impressed. Whorls about seven, convex, the last rounded (or a trifle 
angled) around the lower part, slightly convex beneath; aperture rounded, 
oblique, outer lip fluted within, with a beveled opaque white submargin; 
throat pearly, iridescent; columella simple, arcuate. Alt., 20; diam., 18 mm. 
TyrEin? Type locality ? 
Range. Sitka, Alaska, to San Diego, California. Fossil: Pleistocene, 
San Pedro to San Diego; Pliocene, San Fernando, Los Angeles County, 
California. 
Described as Trochus costatus Martyn. 
Calliostoma costatum caeruleum Dali, 1919 
Proceedings of the United States National Museum, 56:359. 
Shell resembling the ordinary typical form except that the apex and 
part of the whorls in front of the suture are colored with bands of a 
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