NEW YORK ACADEMY OF SCIENCES 595 



been prevented by the northward extension of the Siasconset 

 apron beach, so that the face of the bluff is now covered with 

 talus and overgrown with beach grass. 



The locality was visited during the summer of 1904, and 

 considerable work done in exposing the section and making a 

 collection of the fossils. 



This work resulted in the collection of eighty-one species, 

 twenty-one of which had never been reported from this point, 

 including Pandora crassidens Conrad, not previously found in 

 any horizon above the Miocene, and Serrepes laperousii Des- 

 hayes and Macoma incongrua von Martens, belonging to the 

 Arctic fauna of the Pacific coast and not heretofore reported 

 east of Point Barrow. 



A number of facts differing somewhat from those reported 

 by former observers were noticed, and have resulted in a some- 

 what different interpretation for the phenomena presented by 

 these deposits. 



The deposits are not of glacial origin, for — i. Numerous 

 delicate and unworn shells occur. 2. Bivalves such as Solen, 

 Venus, and Mya occur in the position in which they lived, with 

 both valves together, and in the case of Venus with the ligament 

 in place. 3. The faunas are not mixed as would be the case if 

 of glacial origin, the lower beds containing shoal water species 

 of a southern range, and the upper, deeper water species of a 

 northern and even Arctic type. 



The lower beds were deposited in a shallow inlet or lagoon, 

 as shown by such species as Mya, Osirea, and Venus and 

 especially by numerous mud crabs and the presence of our 

 edible crab, CalUnectes sapidus, while the upper beds were 

 deposited during a subsidence of the area contemporaneous 

 with the advance of the Wisconsin ice sheet, as shown by the 

 deeper water and more northern species. 



After the destruction and washing into the lagoon of the 

 protecting barrier beach, as shown by the overlying rounded 

 and pure white sands, the ice reached and passed this point, 

 eventually burying the beds under fifty feet or more of drift. 

 Later, a re-elevation took place, bringing the land to about its 

 present position. 



