An examination

Joseph Williams Williams, Land and fresh-water shells : an introduction to the study of conchology , Londres, Swan Sonnenschein, 1907, p.9.

An examination of caddis-cases will also often give a large number of water specimen. In a review of the book from whence the above rules have been extracted, which appeared in one of our Natural History « Monthlies », the reviewer in touching upon these points expressed himself to the affect thart when an individual is observed to be faithfullly