Bul. U. S. B. F. 1907 PLATE IV. 
FIG. 1. WATER GLASS DESIGNED BY THE WRITER TO BE USED FOR OBSERVATION OR 
PHOTOGRAPHY OF OBJECTS UNDER WATER 
The cover is shown at the left 
FIG. 2. TWO-FOOT WATER GLASS SUPPORTED ON FOUR LEGS At PROVIDEL 
WITH SCREEN, AS USED FOR STUDYING AND PHOTOGRAPHING LAMPREYS 
LAMPETRA WILDER 
