76 THE NAUTILUS. 



They so closely resemble the spiral pattern on the adult shell 

 that the collector, looking down through the water, not unfrequently 

 stoops to pick up what he thinks is one of these little gasteropods 

 and finds a string of eggs in his fingers. 



I visited Portuguese Bend and learned that Purpura emarginata 

 Desh., which I found in quantity more than a year ago, is a resident 

 or a comer and a goer, for more than a dozen were collected this 

 summer. Its habitat is limited to a small mussel bed. 



Other localities so much like this mussel bed, that one would 

 consider them suitable dwelling places do not boast of a single Pur- 

 pura ; so that something besides collectors must disturb this usually 

 common species. 



I collected at San Pedro an abundance of Acvicea paleacea Gld- 

 on the eel grass. 



These close dingers love the grass on the outside of the island 

 that is swept by heavy swells and where the water scarcely leaves 

 them even in very low tides. 



Their more peaceful cousins Acincea, depida Gld. will j^robably be 

 found swaying with the grass in the stiller waters of the bay, for 

 dead shells have been frequently found in the drift. 



In the quiet bay quantities of drift material are washed up with 

 alg?e and eel grass during medium tides. 



This is rich in minute forms. It consists largely of broken shells 

 of molluscs and crustaceans, but there is a sufiicient quantity of 

 Pedipes, Siphodentalium, Tornatina, Ccecum, Truncatella, Mitromor- 

 pha, Turhonilla, Cerithiopsis, Triforis, Diala, Mumiola and other wee 

 bodies to amply repay any one for carrying away a few pounds of 

 the drift to be dried and sorted at home. 



The sifting and the sorting with a microscope takes so much time 

 and patience, that the new and rare species hidden in my bags of 

 drift must wait a more convenient season. 



The yearly extension of sand flats at San Pedro, must make 

 happy all sand loving species such as Bulla, Sigaretus, Natica, Oli- 

 vella and scores of bivalves. 



Besides these sandy stretches there are mud flats, rocky points, 

 brackish water, fresh water, smooth or rocky beaches enough to 

 make San Pedro an ideal collecting ground. 



Although nearly all the localities are easy of access for the Con- 

 chologist, or the collector who " makes shell flowers, " there are 

 changes enough taking place to insure a good supply of shells. 



