22 College of Forestry 



inches (400 square cm.) would be an improvement, since with 

 it the larger clams could be collected and included in the 

 general estimate. 



The deeper water (6-18 feet) was examined with a large 

 dredge, the rectangular metal framework being 16 inches wide 

 (fig. 2, no. 2). For estimating the number of clams in shallow 

 water (1-3 feet), a square metal frame eight inches square 

 (20 cm. square) was made and found effective for this pur- 

 pose as well as for measuring the density of plant growth 

 (see fig. 2, no. 3). It is regretted that apparatus for taking 

 temperatures and for indicating the degree of transparency 

 were not available. Thermometers intended for this purpose 

 were found to be imperfect when used. The photographs were 

 made with a 5 x 7 view camera. The photographs of the con- 

 tents of certain unit areas figured in the bulletin were obtained 

 by placing the camera upon a frame in a vertical position, 

 pointing downward. The material was sorted in large white 

 crockery plates and the photograph taken with the material 

 under water. 



Methods. All collecting was done from the row boat 

 previously mentioned. Each dredging was made by the writer 

 and the material placed in a suitable vial by an assistant, who 

 also recorded, by dictation, depth, distance from shore, charac- 

 ter of bottom, and the general characteristics of the vegetation 

 of the habitat. On boulder bottoms, where the bottom sampler 

 could not be used, a number of boulders were collected and 

 measured and the life contained on each was carefully removed 

 and placed in vials for examination. On gravel bottoms it 

 was usually possible to use the bottom sampler. In a few 

 cases but one sample was taken from each habitat, but in the 

 majority of habitats examined several samples were obtained, 

 giving a better average in the general results. All material 

 was first preserved in a 5 per cent solution of formaldehyde. 

 It was subsequently found, however, that this preservative had 

 a dissolving effect on such animals as mollusks, causing the 

 shells to disintegrate or become very soft. Later the entire 

 collections were transferred to 80 per cent alcohol. 



