248 ANNUAL RECOED OF SCIENCE AND INDUSTRY. 



reef, which is laid down on the charts as extending from 

 Boorosloff to Umnak. No such reef exists. 



The groups of the Davidoff Islands and Four Craters were 

 found to he very erroneously delineated on all maps. 



Incidentally, collections of natural history of considerable 

 interest were obtained, illustrating the geographical distri- 

 bution of the fauna and flora, which, so far from exhibiting 

 any admixture of Asiatic forms, excej)t one or two sporadic 

 species, grew more and more meagre and arctic in character 

 as the western end of the chain was approached, and the 

 fauna of Attn was found to be purely arctic, so far a? the in- 

 vertebrates are concerned. 



Particular attention was also given to remains of prehis- 

 toric man ; and thirty-six crania, and more than two hundred 

 bone and stone implements, besides several hundred wood 

 carvings, were obtained from ancient village sites, burial 

 places, and caves. The Amaknak and Unga caves, explored 

 last year, were this year thoroughly emptied of their con- 

 tents, and every thing of value carried away. 



A cyclone, which reached the Shumagins in four days from 

 latitude 45 N., wrecked the trading schooner WiUia7n Ire- 

 land on the rocky coast of Unga, the passengers and crew 

 being brought back to civilization by the Yiikon. 



Mr. Dall states that during the past winter of 1872-3, al- 

 though one of the coldest recorded, the thermometer of TJna- 

 lashka did not fall below +10 Fahr., but that the season of 

 spring was fully a month behind the usual time, and that even 

 as late as the 20th of May the field-ice in the Behring Sea en- 

 tirely surrounded the fur-seal islands, and reached within one 

 hundred and thirty miles of Unalashka, a state of things nn- 

 paralleled since 1851. 



Among other incidents of the passage to the North, Dall 

 reports that about the lYth of May the waters to the south 

 of Unalashka were found to be swarming with the eggs of 

 cod-fish, floating like little pearls, about six inches below the 

 surface of the water. 



DE. HAYDEN's geological EXPLOEATIONS IN" 1873. 



The labors of Professor Hay den, of the United States Geo- 

 logical Survey of the Territories, and his party, have been 

 prosecuted during the year 1873, and the field work brought 



