1876.] Proceedings of Societies. 189 
shell-heaps of the Aleutian Islands. He showed that they were sep- 
arated into three successive periods, indicated by the remains of food 
contained in the shell-heaps, namely, lower or Echinus layer (Littoral 
Period), composed of the remains of Echini and mollusk-shells; middle 
or fish-bone layer (Fishing Period), composed principally of the remains 
of fish; and lastly, the mammalian layer (Hunting Period), composed 
principally of bones of sea animals and birds. Above all this came the 
remains of the more modern village sites. 
The first period might have extended over a thousand years ; the length 
of the others there is no means of approximating. The first layer con- 
tained few and very rude implements, and a gradual progression was 
observed in the variety and finish of the implements and weapons of the 
succeeding layers. Only toward the last were there any signs of the use 
of houses, fire, or ornamentation of tools or other articles, The charac- 
ter of the latter showed that the early inhabitants formed their tools and 
weapons after’ the Eskimo patterns, but these gradually became differ- 
entiated into a type peculiar to the islands. Mr. Dall considered it 
probable that the first inhabitants were Eskimo of*a low type, who took 
to the islands for protection, coming from America, and in their re- 
stricted surroundings in the course of ages developed into a special type, 
without entirely effacing the links which connect them with the Eskimo 
in language, physique, and fabrications. 
Dr. Bessels read a paper on the hygrometric properties of the atmos- 
phere in the Arctic regions. 
Boston Socrery or NATURAL History.— January 19th. Mr. T.T. 
Bouvé read a paper on the origin of porphyry, in which it was claimed 
that the rock was an altered conglomerate. Professor Hyatt exhibited 
4 geological map of Marblehead Neck. The conglomeritic character of 
the porphyries of this locality were particularly dwelt upon, and a large 
series of specimens exhibited. A paper by Mr. L. S. Burbank on the 
conglomerates of Harvard, Mass., and their relations to the crystalline 
rocks, followed. 
February 2d. Dr. W. K. Brooks read a paper on the development of 
Astyris (Columbella) /unata. This is the first siphonated gasteropod 
whose embryological history has been followed. Some general views on 
the molluscan pedigree were added. Mr. S. H. Scudder read a paper 
on the way in which cockroaches and earwigs fold their wings. 
ACADEMY or NATURAL Sciences, Philadelphia. — February 4th. 
The collections of the academy are being arranged as rapidly as possible 
m the new building, and it is hoped that the museum will be thrown 
*pen for the inspection of the public early in the coming spring. — 
Professor Cope exhibited a fragment of a leg-bone of a fossil bird dis- 
covered by him during the explorations in New Mexico conducted by 
Lieutenant Wheeler. It resembles in many points those of the ostrich 
and the extinct Dinornis of New Zealand, and its sizé indicates a species 
