262 BULLETIN UNlVpmSITY OF MONTANA 



opening, as also by its recurring in a given manner. Observe whether 

 the break is haphazard or shows evidence of careful selection as to place. 

 Geographical Distribution. Having found the name of the specimen 

 in the snailery, it may be possible to find how extensively it is distributed 

 over the state, over the United States, or over the world. This informa- 

 tion may be had by consulting a library with conchological literature, or 

 by inquiry of friends versed in knowledge of shells. In any event, 

 whether the information is found or not, suggestions may be thrown out 

 as to ways by which the species may be scattered, reasons for dispersal, 

 and barriers which may prevent it. 



