94 AMERICAN MIDLAND NATURALIST 



and always exposed to sun and air; consequently warmer than 

 pools below the tide-line; sometimes reaching 7o°F. At this and 

 the previous place, III., temperatures were taken; they ranged 

 from 53°F to 63°F. Thus, allowing lo ft. between low and high 

 (it is nearly 12 ft.) there is an average difference of 1° for each 

 ft. of altitude. 



V. Argyle Bay. This is really the outlet to a large pond or 

 basin that is drained almost completely when tides are lowest. 

 The flood comes in over an expanse of w^arm gravel and the pool 

 is shallow so the water may reach at times a temperature of 60° 

 to 7o°F. At the outlet the water is constantly flowing either in 

 or out with considerable current, thus renewing the air and food 

 supplies. 



Nos. I and 2 are not found here as the banks are loose gravel 

 instead of soHd rock; and the quiet water conditions of other places 

 do not exist. 



No. 4, however, is found attached to large pebbles on the 

 bottom and attaining great size; fronds over a foot in length and 

 over an inch in width. 



No. 5, also in great abundance fastened to pebbles. 



Nos. 6, 7 and 8, though present are rare and not important, 

 but No. 9, Entermorpha linza finds this a most congenial place. 



VI. Roche Harbor, Henry Island and Ship Island. These 

 show nothing new and are of interest only in so far as they confirm 

 the conclusions already reached in the study of Prioniiis and its 

 variations elsewhere. 



VII. "Gull Rocks," just off west side of Waldron Island. 

 Excellent pools, varying in size and altitude, but containing almost 

 nothing of interest except Prioniiis. The conditions as to altitude, 

 temperature, etc., are similar to those described under iV. 



VIII. Kanaka Bay, also known as False Bay, south end of 

 San Juan Island, drains completely at extreme low tide, when 

 study was made east side of entrance. 



This afforded a number of small pools and one larger than 

 any found elsewhere; especially good. Although there is a great 

 variety of material in this region there was nothing new in tide- 

 pool conditions, except 10, Soranthcra sp. Prioniiis shows a greater 

 variety of size and form here than possibly in any other place 

 examined. It is doubtful whether it could all be classed under 

 the two species, 3 and 4. Possibly it should all be classed as one 



