68 jfirst annual deport 



SOME OF THE MOLLUSCA OF 

 LACUNA 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, I 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 3'2) 



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. 



