338 University of California Publications in Zoology (Vou. 14 
This species was not found in the collections dredged by the 
““Albatross.’? Wood and Raymond (1891) reported it from San 
Francisco County. 
Range.—California to Alaska (Tryon). 
Thais emarginata (Deshayes) 
Purpura saxicola var. emarginata Deshayes, Carpenter (1863), p. 62: Wood 
and Raymond (1891), p. 57. 
Purpura emarginata, Tryon (1880), p. 175, pl. 53, fig. 156. 
Thais emarginata, Dall (1915a), p. 5. 
Description.—Tryon characterized this species as follows: 
““When the revolving ribs of saxicola or ostrina become broken up into 
nodules, the result is P. emarginata Desh., which is typically a very distinct 
looking shell, but connected by minute gradations with the smoothest ostrina.’’ 
Wood and Raymond recognized this species from this region. It 
was not obtained by the Survey. 
San Francisco to Santa Rosa, California. 
Range. 
Thais emarginata (Deshayes) var. ostrina (Gould) 
Plate 39, figures 2, 3, 4, and 5 
Purpura ostrina Gould (1853), p. 244; (1862), p. 225. 
Purpura saxicola yar. ostrina, Carpenter (1863), p. 662; Tryon (1880), p. 
174, pl. 53, fig. 154; Wood and Raymond (1891), p. 57. 
Thais emarginata var. ostrina, Dall (1915a), p. 570. 
Description.—Gould (1853) described this variety as follows: 
““Small shell, solid, broad-ovate, purplish, banded with brown lines, generally 
in pairs, faintly marked with the lines of growth, and sometimes with obtuse 
revolving ribs. Whorls four or five obtusely angular posteriorly, convex, the 
last comprising most of the shell, very smooth, simple; pillar broadly flattened, 
regularly arcuate, chestnut-colored; aperture livid chestnut, paler near lip.’’ 
Height, 8 to 20 mm. 
Occurrence.—At Presidio* (66), Bonita Point (24), and question- 
ably from stations D 5732, D 5786, D 5808, D 5809. 
This form has been recorded both by Carpenter and Wood and 
Raymond from the vicinity of San Francisco. Determinable speci- 
mens referable to this variety were obtained by the Survey only at the 
shore stations. Fragments that probably belong to this species were 
dredged within the Golden Gate and in the vicinity of the Farallon 
Islands. 
Range.—Tillamook, Oregon, the type locality, to Santa Barbara, 
California (Yates). 
