THE NAUTILUS. . 65 
Semele decisa, Saxidomus nuttalli and other bivalves were 
equally abundant, but now nearly exterminated. A list of the 
mollusca from this bed would be extremely interesting, but now 
hopeless of ever being written, as it is no longer the ideal home 
for mollusks that it once was. Over 100 Cypraea spadicea were 
found there in one day, and an equal number of Ranella cali- 
fornica were yielded by the adjacent sandy beaches. While the 
shells from this lagoon do not properly belong with the La Jolla 
list, yet fragments or dead specimens of all noted by Mr. Smith 
may occasionally be found at La Jolla. 
Tagelus californianus.—This is extremely abundant in False 
Bay and is gathered in quantities for bait by fishermen, and 
thus the shells are scattered freely all along the La Jolla shores. 
Pedipes unisulcata.—Smith reports many of the dead shells 
attached to sea anemones, but I found it years ago in company 
with Truncatella stmpsont on round water-washed boulders in 
caves near La Jolla. 
Pedipes liratus.—This was also found at La Jolla in early 
days and later by Prof. Kelsey. 
Milnerea minima.—Abundant. Attached to the under side 
of stones. Usually reported as living on the shells of Haliotis. 
Mytilus adamsianus.—This was long called M. bifurcatus, later 
known as WM. stearnsi. Smith and Bailey, like many other col- 
lectors, seem to have overlooked it, probably mistaking it for 
the young of Septifer bifurcatus which it nearly resembles, except 
for the absence of the septum. It is equally abundant. 
Mytilus denticulatus.—This is similar to the last but much 
smaller. It is Modiolaria denticulata of former lists, and might 
easily be overlooked, but is apparently not rare on our rocks. 
Adula diegensis.—North of the Scripps Biological Station 
about a mile north of La Jolla is a rocky beach at the base of 
high cliffs. Much of the rock is a soft clay stone, and perfor- 
ated by millions of pholads. In places this species has entire 
possession, and often they have made their cells so close to- 
gether that no partitions of rock are left to separate the shells. 
Pholas pacifica.—This is one of the pholads found at the 
above station with others already noted. 
Petricola denticulata.—This is extremely abundant in the 
