SHELLS OF LAKES AND STREAMS 317 



The young are born alive as in the Sph^eridie instead 

 ot developing from eggs. 



Vivipara inallcatiis^ Reeve, the Four-lined \'ivi- 

 para, or Japanese Rice-snail, PL III, Fig. 8, is a 

 large species which has been planted for food, 

 at many places where there are Asiatic settlements 

 on the Coast. Its flourishing progeny are by birth 

 American citizens, and so we must consider them. 

 The shell has green or brown inflated whorls, marked 

 by tour revolving lines of minute punctures, two 

 above, one at, and one below the suture. In juvenile 

 specimens the whorls are carinate but in adults they 

 are rounded. It is known so tar in ditches and 

 streams in the Coast Range System but has been 

 reported from the markets of Victoria, B. C. Japan. 



FALSE SHELLS 



Among the material gathered by young collectors 

 are often small bivalve Crustacea, Phyllopods and 

 Copepods which when dead greatly resemble Sphseri- 

 dse. To see them swimming around when alive will 

 soon convince one they are not mollusks. The shells 

 are very thin and made of chitin which will burn 

 readily. This is a simple way to distinguish them. 

 Caddice-fly larva? often make spiral nests of sand 

 grains. The great Doctor Lea once described one 

 of these as Valvata arenlfera. 



This closer the descriptions of the most puzzling 

 of our West American shells. To some they may 

 not be of interest because they are so plain, so vari- 

 able, so near at hand, and so little known; but to 



