E. M. Kindle — Criteria of Continental Deposits. 229 



can shell was obtained. At Cape Prince of Wales, however, 

 which is 100 miles northwest of Nome, the writer collected in 

 two hours 45 species. Although the coastal waters at Cape 

 Prince of Wales and various points to the northeastward sup- 

 port a rich and varied fauna, the nearly barren zone begins 

 immediately south of the cape and continues unbroken, save by 

 very rare examples of sea shells, for more than 100 miles along 

 the southwest coast of the Seward peninsula. 



On the northwest coast of Greenland the writer has used a 

 dredge where on one side of a peninsula every haul brought up 

 numbers of shells while on the opposite side not a single mol- 

 lusk was secured. 



Such facts as these, although they appear to be unfamiliar 

 to some paleontologists, are in no wise exceptional or unusual, 

 as will be seen from the following quotation from Godwin- 

 Austen :* 



"There is a zone of clean sand in advance of most lines of coast 

 which comes within the range of the tidal and wave disturbance 

 of the water, where deposits are being formed, which, after a 

 while, are broken up again, and which may be called the drift- 

 sand zone. This is wholly unfitted for marine life, and the only 

 organic forms it ever contains consist in the fragmentary shells 

 and tests of other zones. I have dredged along a band of this 

 kind for thirty miles on our own coast without finding a single 

 living form." 



The exploration of the sea bottom off the west coast of 

 America by the Albatross in 1904 and 1905, although in much 

 deeper waters than we are concerned with in epicontinental 

 seas, has shown in a remarkable manner the effectiveness of an 

 ocean current in controlling the distribution of marine life. 

 This expedition, which was in charge of Alexander Agassiz, 

 found that the bottom under the Humboldt current is crowded 

 with organisms, whereas there is a sparsely inhabited submarine 

 desert to the westward of the western edge of the current. 



In view of the examples of synchronous barren and richly 

 tenanted zones which have been cited in the seas of the present, 

 it seems apparent that absence of fossils from any part of a 

 formation can not be accepted as evidence of nonmarine origin. 

 Since both barren beds and cross-bedding are occasional char- 

 acteristics of both marine and nonmarine beds, it seems evident 

 that neither of these features can be cited as evidence of either 

 kind of origin. Cross-bedding affords decisive evidence of 

 current or wave action, but it does not indicate whether the 

 action occurred in marine or continental waters. 



In the present stage of development of the criteria of conti- 

 nental deposits it will be wise to use with extreme caution any 

 * Natural History of the European Seas, p. 233. 



