68 first Annual Report 
SOME OF THE MOLLUSCA OF 
LAGUNA BEACH 
MABEL GUERNSEY 
Wishing to study the gross anatomy of the soft parts of some 
of the common mollusks of our Coast, and spending some time at 
Laguna in the pursuit of this object, | improved the opportunity to 
bring together all such species as came in my way to serve as the 
beginning of a faunal list of the local mollusks of the tidal zone. A 
set of most of the shells collected was sent to Dr.Dall, who very 
kindly gave us the determinations. Some of my anatomical work is 
not at all complete, but I am hoping to continue it another season. 
GASTEROPODA 
AMPHINEURA 
Ischnochiton clathratus Roe 
Ischnochiton magdalensis Mds. 
(Figure 32) 
Mopalia hindsii Gray 
Mopalia muscosa Gld. 
Nuttallina scabra Roe 
All of the above five chitons are found clinging to rocks between 
tides. The second species is by far the most common, while the last 
is quite rare. 
PROSOBRANCHIATA 
Acmaea scabra Roe 
(Figure 33) 
Common in tide-pools. 
Acmaea persona Esch. 
Common on rocks covered only by the highest tides. 
Acmaea spectrum Roe 
Distribution the same as Acmaea persona but much rarer. 
Acmaea asmi Midd. 
Found on other shells, usually of other limpets in tide-pools, and 
fairly common. 
Lottia gigantea Gray 
(Figure 34) 
Found in a few channels where there is constant and violent wave 
action, and fairly numerous where found. 
