1912] Ritter: The Marine Biological Station of San Diego — 209 
The particular thing brought out in this discussion is the applica- 
bility of V. W. Ekman’s theory of oceanic circulation to the facts 
observed. 
While this is all that has been published on hydrography as 
such, the extent and importance of the hydrographic work as an 
adjunct to the biological investigations are indicated by the use 
made of this data in the papers of Michael and Hsterly. 
The earlier data collected but not yet published should be 
referred to. During the summer of 1901 a series of temperature 
and density determinations were made by Professor W. J. 
Raymond of the Physics Department, University of California 
From 1903 to 1906 considerable work was done in this way, par- 
ticularly on the San Diego Bay and in-shore water by Mr. W. T. 
Skilling, teacher of physics and chemistry of the State Normal 
School at San Diego. Mr. Skilling also began work on the 
chemistry of the water. 
Under this head reference should be made to the modeled 
topographic map (pl. 24, fig. 10) of the continental shelf and 
adjacent land area of Southern California constructed in 1906 
by Professor R. S. Holway of the Department of Geography, 
University of California. This was constructed partly on the 
basis of soundings taken by the station’s boats, though more from 
the work of the United States Coast and Geodetic Survey and 
other departments of the national government. This map is very 
useful in several ways for the operations at sea. 
