74 



MATTOX 



The area studied lies off the north eastern shore of Santa Catalina 

 Island between the region of Long Point and the north west end of the 

 island (Fig. 1), located geographically approximately from 33°22' to 

 33°28' north latitude and 118°22' to 118°38' west longitude. The entire 

 area along the eastern shore of Catalina has been well sampled during 

 the past twenty years so that the general habitat in which living brachio- 

 pods occur can be indicated. Brachiopods have been found here mainly 



Fig. 1. Outline map of Santa Catalina Island, "x" indicates locations 

 of collections containing brachiopods. The contour lines rep- 

 resent the 50 and 100 fathom depths. 



at depths of from 30 to 80 fathoms on the rather steeply sloping shelf 

 of the island, but in some instances as deep as 120 fathoms. The sub- 

 stratum here is in general solid, with many rocky and pebble areas as 

 well as sand and some sandy mud bottoms. 



The available temperature records for this area indicate seasonal 

 surface variations from 14 to 22° C. At the 50 fathom depth the annual 

 variation is little more than one degree from the average of 10° C. 

 Periodic upwellings of cool waters have been recorded along the northern 

 limits of this shore, providing for a circulation of water and a cooling 



