types, and therefore are dependent upon the existence of 

 essentially littoral conditions. 



Though it is conceivable that the species of Fl&r&metra might 

 have attained their present distribution by slowly spreading 

 along the stagant water bordering the abysses, still it is not 

 possible to imagine such a perfect continuity of physiological, 

 economic and physical conditions in the water at the depths 

 at which Florometra lives without at the same time (taking into 

 consideration what we know in regard to the distribution of 

 littoral organisms and the effect of the surface currents) enter- 

 taining the supposition that a continuous, though slow, flow of 

 water along these levels serves to preserve this uniformity. 



From the progressive increase in the bathymétrie and 

 thermal range of the species of this genus northward, westward 

 and southward we should infer that such a flow originated in 

 the antarctic, and was continued, with gradually decreasing 

 velocity, north to Alaska, west to Attu Island, and thence 

 south by some undetermined channel to Japan, eventually 

 reaching Tokyo and Sagami Bays. 



It is not necessary to suppose that the water in which these 

 species live is at all points entirely derived from the antarctic 

 regions. At first all of it is, but, during the passage of this 

 antarctic stream northward along the western coast of South 

 America, the rotation of the earth turns much of it seaward ; 

 this very action, however, brings to the surface further in-shore 

 abyssal water, indistinguishable from it, which continues the 

 northerly course. Probably before the antarctic water reaches 

 the equator a considerable amount of it is lost ; but no matter 

 how much may be lost off shore, it will all be replenished by 

 exactly the same quality of w T ater, brought up from the deeps. 



Off the west coast of South America we find the powerful 

 South Pacific, Peruvian or Humbolt current, flowing northward. 

 This, on approaching the equator, at the surface becomes 

 more and more deflected toward the west, chiefly through the 

 action of the winds, but also to some extent by the action of the 

 rotation of the earth, and disappears as a surface current at 

 about the latitude of the equator. But the identical species 

 of crinoid peculiarly characteristic of the Magellanic region 



