to a half inch in length. The Professor told us that these small clanis 

 live plentifully in pools, ponds, ditches, and streams. 



In about an hour we reached Lake M- , and walked along the 

 shore for some distance in search of molluscan life, but met with little 

 success as far as living species were concerned. In the line of debris 

 which had been thrown up by the waves, we found a large number of 

 very small snails and clams and a host 

 of insects belonging to the beetle order. 

 George managed to find several large clams 

 like those which were so plentiful in Lake 

 C- , but with very much heavier shells. 

 We asked Professor Parker if they be- 

 longed to the same species and he said 

 they did. He told us that the reason 



Calyculina transversa, with its 

 long, narrow foot and two short si- 

 phons extended. (Prime's Mono- 

 graph.) 



they were so heavy was because the waters 



of a lare lake like Lake M - were very rough, and that the shells 





were subject to a great deal of rolling about, while the waters of the 

 smaller lakes were comparatively calm, and the shells, being allowed 

 to remain quiet, were consequently more delicate. We also learned 

 that the Anodontas, which have thin shells, are generally found hi still 

 bodies of water on muddy bottoms, while the Unios, which have very 

 thick, solid shells, prefer, as a rule, the bed of running streams. 



We reached home late that night, footsore and weary and desper- 

 ately hungry, but with our bottles, pockets, and baskets filled with 

 shells, and our minds fresh with the memory of a joyful day spent in 

 communion with Mother Nature. 



