290 University of California Publications in Zoology [Vol. 23 



Coe said (1910, p. 118) : 



There can be no doubt that future collections will add materially to the 

 number of... [nemerteans] , whose range extends at least as far southward as 

 Monterey Bay or even to Point Conception. And while this is a considerable 

 range geographically, yet the environmental conditions of marine forms are not 

 greatly different between Monterey Bay, Puget Sound, Sitka and the Eastern 

 Aleutian Islands. The temperature of the water is but a few degrees different 

 and in some seasons of the year is actually warmer on the coast in portions of 

 Alaska than it is in Puget Sound, or even in the deeper water off the California 

 coast. 



Furthermore, although his faunal districts do not seem to have 



been founded on any such basis, Verrill said of his west coast starfishes 



(1914, p. 19) : 



The limits of distribution on that coast seem to be determined entirely by the 

 temperature of the water, especially in the breeding season, due probably to the 

 greater sensitiveness of the free-swimming larval forms. The adults can regulate 

 their temperatures by migrating into deeper or shallower water as occasions 

 require. 



As Ortmann anticipated, and Torrey and Coe more or less suc- 

 cessfully demonstrated, there exists a comparative uniformity of 

 temperature along a considerable part of the west coast, which permits 

 the great latitudinal and intricately overlapping distribution of the 

 marine organisms with which we are here concerned, and which is 

 necessary to the establishment of our faunal area. 



North of California to the Aleutians is a vast stretch of coast 

 which with the exception of isolated glacier fed bays is warmed much 

 above the temperature normal to such latitudes by the Kuro Siwo, the 

 Japan current. This strikes the American coast in the neighborhood 

 of Sitka where it separates into two streams, a northern, running up 

 into the Gulf of Alaska and thence southeastward along the Alaska 

 Peninsula into the eastern Aleutians, and a southern one which 

 "broadens out and drifts slowly toward the equator, curving away 

 from the coast. ' ' 



South of Puget Sound to about Magdalena Bay is a region of 

 almost equal extent which is cooled by an upwelling of cold abyssal 

 water to a degree considerably below the normal expectation for its 

 latitude. 4 The surface water along this section of the coast also 

 exhibits a southward drift, and though it is known as the California 



* "Between the latitudes 45° ... and 25° . . . the mean annual surface tempera- 

 ture is progressively lower as the coast is approached. This fall in mean annual 

 temperature is clearly indicated at every depth from 250 fathoms up to the 

 surface, where there is an inshore temperature averaging 5° less than that found 

 1,000 miles off-shore. . . . The [appended] tables show that the off-shore surface 

 temperatures at latitude 30° are much below the normal (the temperature given 

 in the first column), while those at latitude 40° are somewhat greater, at least in 



