122 DEPARTMEXT OF THE yiVAL SERTIOE 



6 GEORGE V, A. 1916 



Isopods are not so numerous in species but are by no means lacking in number of 

 individuals. As to molluscs, Taylor's papers' will indicate very well the number of 

 species and Thompson's-^ papers indicate the extent of the beds of some of the edible 

 forms. If echinoderms serve as toothsome morsels, the lobster may feast at will along 

 this coast. Starfish are so numerous as to be almost a plague; two species of sea- 

 urchins are present in abundance, and, if it will only tackle the holothurians, SticJwpus 

 calif ornicus shoiild supply him with trepang for many days in the year. The abund- 

 ance of hydroids in indicated by some of my own papers, particularly the most recent.* 

 In many places the sea-bottom is carpeted with them, while around the rocks, piles, 

 etc., at and below low-tide they appear in great quantities. If the lobster enjoys a 

 meal of these as the crab evidently does, it may have them for dessert as often as it 

 wishes. Eel-grass, fucus and kelp are everywhere abundant if it chooses to turn 

 vegetarian. As far as food material is concerned, therefore, there need be no lack. 



T. Temperature Conditions in British Columbla. Waters. 



Another condition on which considerable stress has been laid is the temperature 

 of the water. Although that is the case, there has really been very little ground on 

 which to base a comparison. Eathbun (cf. p. 454) makes the statement: "The con- 

 tinuous temperature observations in the possession of the Fish Commission relate 

 mainly to the surface waters, but in the shallow areas where they were taken there is 

 generally not much difference in this respect between the surface and the bottom." 

 That may be true at the points referred to and yet in the temi^erature charts for the 

 vicinity of Woods Hole,^ a difference of 4 degrees or even more is shown in some 

 instances in the very shallow water of Buzzards bay. At present we have not very 

 many readings at various depths for this district but the few we have indicate that it 

 is not safe to make such a statement. As an instance, at a point in Departure bay, 

 which is nowhere much mOre than 2.5 fathoms deep, the following readings were taken 

 on July 15, 1914 :— 



C.3-l° F. 

 61-0° P. 

 60-4" F. 

 59-5° F. 

 ST-a" F. 

 56-3'' F. 

 53-8° F. 

 51-4° F. 

 50-7= F. 



A more sudden change was shown on October 14, 1914, when the following read-, 

 ings were obtained: — 



Surface ' 52*9° F. 



1 fathom 49-73° F. 



2 " 49-46° F. 



3 " 49-19° F. 



4 " 49-01° F. 



5 " 48-83° F. 



10 " 48-65° F. 



20 " 48-49° F. 



1 Taylor, G. W., B.C. Decaod Crustaceans, Contributions to Canadian Biology, 1906-1910, 

 pp. 187-214. 



2 Taylor, G. W., Prelimimry Catalogue of the Marine Mollusca of the Pacific Coast of 

 Canada. Trans. Royal Soc. of Canada, Sec. iv, 1895, pp. 17-100. 



Notes on the Maiine Mollusca of the Pacific Coast of Canada, Trans. Royal Soc, Sec. iv, 

 1899, pp. 233-250. 



3 Thompson, W. F., Report of the Commissioner of Fisheries for B.C., 1912, pp. 17-156; 



1913, pp. R 103-R13n. 



4 Hydroids of Vancouver Island Region. Trans, of the Royal Society of Canada, Sec. iv, 



1914, pp. 99-216. 



•■• .'^umner, Osburn and Cole, A Biological Survey of the Waters of Woods Hole and Vicinity. 

 Bull. U. S. Bureau of Fisheries, vol. XXXI, 1913, pp. 429-432. 



