— 23 - 



surface, with which it coninuinicates hy means of two slender separate 

 siphons and, like Macoma, its presence is made known by pairs of holes 

 at the surface (see figiire 22). 



A tiny nearly smooth species of Cardiiim. is found at the surface with 

 Chione, but the edible cockle (Cardium corfois) was not seen here though 

 it occupies similar locations farther to the north. 



The piles of the railroad and w^agon bridges crossing the outlet 

 furnish attachment for a limited number of sea mussels which are 

 used locally as bait. In shallow Avater along the sloughs the native 

 oyster is found wherever old shells or similar objects afford attach- 

 ment. The two fonns just mentioned represent, in this locality, the 

 group of fixed mollusks. 



The census of the inlet aside from species too small to be edible is 

 completed by the scallop, Pecten circidaris. At low tide it may be seen 

 lying on its right side on the surface of the bare flats or in shallow 

 water on a variety of l)ottom though not on the steep slopes of the 

 spit or near the entrance. The fact that the scallop is less sharply 

 restricted to a particular kind of bottom than are the other species 

 just considered is due to its active habits, for this form is, as already 

 stated, practically unique among bivalves in being able to swim througli 

 the water by clapping its valves together. In this way it moves about 

 or turns over if placed wrong side up. Though it can not "swim" 

 in the purposive manner of a fish, its movements serve to keep it in 

 the proper feeding position, to keep off silt which would tend to 

 bury it and to enable it t^j escape some of its enemies. 



Practically all the species treated in the present paper are thus found 

 in the waters of, or adjacent to, Anaheim Creek, and their relation to 

 the physical conditions are illustrated in its main features. This may 

 serve as a point of departure for those wishing to learn more of their 

 habits or, if the principles are applied to other bays, the amateur 

 clam digger may readily judge where to dig for his dinner. 



