1918 ] Packard: Molluscan Fauna from San Francisco Bay 263 
Lon. of shell 7.0; of rostrum 2.5; alt. of shell 3.6; diam. 2.75 mm. Color yellowish 
white; ossicle as usual; buttress present in the right valve.’’ 
Length, 7 to 15 mm. 
Occurrence.—At station D 5789 (6, 3). 
This form was dredged by the Survey at a_ single station outside 
the Golden Gate from a depth of 68 fathoms. 
Range.—Puget Sound to San Diego, California (Dall). 
CHAMACEA 
CHAMIDEA 
Chama Linnaeus 
Chama pellucida (Broderip) 
Chama spinosa, var., pellucida Broderip (1834), p. 150. 
Chama pellucida, Carpenter (1863), p. 641; Cooper (1870a), p. 53; Arnold, 
R. (1908), p. 180; Keep (1911), p. 70. 
Description.—The following is Arnold’s (1903) description of this species: 
“«Shell of medium size; right valve (attached), exceedingly ventriose, rather 
thin; left valve nearly flat, thicker; surface of attached valve sculptured with 
numerous prominent, spiny frills; surface of upper valve with more numerous, 
small frills, which are sometimes spiny near the margin of the valve; hinge- 
teeth and muscle-impressions as in C. exogyra.’’ 
Carpenter (1863, p. 641) reports this species from San Francisco 
and Cooper (1870a, p. 53) lists it from the Farallon Islands. It is 
not found among the Survey collections. Outside the Golden Gate 
it has been found within intertidal areas, both north and south of 
San Francisco. 
Range.—Oregon to Chile (Dall). 
LUCINACEA 
LUCINIDAE 
Phacoides (Blainville) Gray 
Phacoides annulatus (Reeve) 
Plate 19, figures 5a and 5b 
Lucina annulatus Reeve (1851), pl. 4, fig. 17. 
Lucina borealis, Carpenter (1863), p. 643. 
Lucina acutilineata Conrad, Arnold, R. (1903), p. 131. 
Phacoides annulatus, Dall (1901b), p. 828; Dall (19038a), p. 1379. 
Description.—Arnold described this species as follows: 
““Shell large, orbicular, only slightly convex, rather thin; umbones depressed, 
central; surface ornamented by numerous equal, equidistant, sharp, raised, con- 
centric lines; interspaces show lines of growth; lunule small, but deeply 
impressed and distinct; two sharp cardinal teeth in eacn valve; lateral teeth 
nearly obsolete; anterior muscle impression much elongated.’’ 
Length, 14 to 65 mm. 
