'.»i', RECONNAISSANCE IX NORTHERN ALASKA IN 1901. 



long stretches of K>n\ shelving beach. The ice dill's appear merely to represent com- 

 pletely solidified bays, lagoons, lakelets, or perhaps other coastal bodies of ponded 

 water now raised into low anticlines and cut back by wave action. 



From Point Harrow to Gape Idsburne. — Southwest of Point Barrow the coast 

 line grows more marked. It is not .so low. flat, and shelving as on the north, and the 

 water is consequently less shoal. Here the long stretches of mud flats found on the 

 north are in the main wanting. The mainland bluffs at the edge of the tundra, 

 though still low. are not only higher than on the north but are almost continuous, 

 and are frequently composed of true bed rock (Mesozoic terranes); between the 

 base of these bluffs and tide water there is a narrow fringe of recent beach gravels 

 and sand, whose surface slopes steeply seaward. However, from Wainwright Inlet 

 to near Cape Beaufort there are extensive wave-built barrier beaches or bars of 

 recent marine gravels and sand (see PI. XVI, A), sheltering immense stretches of 

 brackish lagoons lying between the bars and the mainland. Toward Cape Lisburne, 

 the most bold and important promontory in this part of the northwest, the coast 

 becomes steep and rock bound (PL V) by the Mesozoics and Paleozoics that have 

 been described. 



RECENT FOSSILS FROM THE ARCTIC COAST. 



The following invertebrate fossils were collected along the Arctic coast between 

 Colville River and Cape Lisburne. The identifications are by Dr. W. H. Dall, of 

 the United states Geological Survey. 



Chrysodomus fornicatus Gray, 649,° 650, 654. 



C. despectus L., 639. 



Admete couthouyi Jay, 652. 



Margarites striatus Sowerby, 647. 



Tellina lutea Gray, 647. 



Macoma frigida Hanley, 636, 639, 647, 650. 



M. tenuis Leach, 639, 652. 



M. baltica var. inconspicua B. & S., 636. 



Astarte arctica Gray, 636, 639. 



A. borealis Schumacher, 636, 639, 650, 652, 654. 



Venericardia alaskana Dall, 652. 



Saxicava arctica L. , 650. 



Serripes gronlandicus Beck, 636, 654. 



Cyrtodaria kiirriana (M6rch) Dunker, 639, 650. 



Thraeia beringi Dall, 654. 



Mytilus edulis L., 650. 



Modiolaria nigra Gray, 650. 



Yoldia sp. fragm., 639. 



a The numbers refer to localities. 



