94 WEST COAST SHELLS 



reaching the water by its two small, red siphons. 

 The shell is smooth, flat and thin, rounded in front, 

 but narrowed and bent to one side behind. The hinge- 

 teeth are small, and in one valve the pallial sinus 

 reaches to the forward muscle-scar. The color of 

 the shell is white, and its common length is two 

 inches. 



Macoma inquinata^ Desh., the Polluted Macoma, 

 is a variable mollusk, resembling a degraded form of 

 the last species. It can be distinguished, however, 

 because the pallial sinus does not touch the forward 

 muscle-scar in either valve. The shell is white, and 

 it measures about an inch and a half in length. This 

 species ranges from the far north down to Monterey 

 on this side of the ocean, and to Japan on the eastern 

 border. 



Macoma balthica, Linn., var. in- 

 conspicua^ Brod. & Sby., the Little 

 Macoma, is well shown in Figure 73. 

 The little shell is thin, flat, and either 

 white or pink. The figure represents 

 a good-sized specimen, though it sometimes grows to 

 be still larger. It is a lover of cold water, and is 

 found on both sides of the Pacific Ocean, and also 

 in the Atlantic, particularly in the Baltic Sea. On 

 the California coast it reaches as far south as Mon- 

 terey. 



Macoma inflatula^ Dall, the Inflated Macoma, 

 resembles a young M. nasuta, but it is thin, rather 

 inflated, strongly bent, and has a pointed pos- 

 terior and a greenish epidermis. It is a northern 

 species, but is found in deep water farther to the 

 south. 



