DESCRIPTIONS OF NEW SPECIES OF MOLLUSKS FROM 
THE PACIFIC COAST OF THE UNITED STATES, 
WITH NOTES ON OTHER MOLLUSKS FROM THE 
SAME REGION. 
By Winuiam Heatry Dat, 
Curator Division of Mollusks, U. S. National Museum. 
The generosity and interest of correspondents on the Pacific coast, 
especially in Southern California, through small but continuous con- 
tributions, have greatly enriched the series of mollusks from the 
Pacific States in the collection of the U. S. National Museum. Not 
only has the wider geographical range of known species thus been 
made evident, but new species or varieties are constantly coming in 
as the fruit of their researches. It is probable that this may con- 
tinue for some time to come, as experience has shown that the rarities 
of one season become commonplace residents during another, as was 
shown in the summer of 1907, when Calliostoma supragranosum 
Carpenter, previously known by half a dozen specimens collected 
during the last forty-five years, swarmed on the new Government 
breakwater at San Pedro, to the surprise and delight of collectors. 
While the hoped-for manual of west.coast shells is in process of 
preparation it becomes necessary, for the convenience of collectors, to 
assign names to the treasures they discover, and in order that manu- 
script names may not pester the bibliographer, these names must 
from time to time be published. The present paper is one of several 
by the writer which owe their existence to these conditions and record 
our indebtedness to the energetic amateur students of the mollusca of 
the region mentioned. 
No region out of the Tropics appears to be richer in interesting 
mollusks than the Californian coast. On the Atlantic we have to pro- 
ceed to the Floridian peninsula for a parallel, and even then the dis- 
crepancy in favor of California remains great. Perhaps nowhere in 
the world may those seeking rest or recuperation find a more con- 
genial and comfortable opportunity, at any season of the year, for 
occupying themselves with what the old- French conchologists called 
PROCEEDINGS U. S. NATIONAL MUSEUM, VOL. XXXIV—No. 1610. 
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