Personal and Scientiiic News. 121 
to produce the same product from rocks originally the most diverse in 
origin and structure. Illustrated by maps, diagrams and specimens, 
both macroscopic and microscopic. The subject was discussed by 
Newberry, Emerson, Lawson, Gilbert and G. H. Williams. Professor 
Emerson stated that the so-called Munson granite, extensively used 
for building, everywhere contains some pebbles. It stretches across 
the state of Massachusetts and wraps around the Archfean nuclei. ■ 
Mr. C. D. White read a paper on "Cretaceous plants from Martha's 
Vineyard." A very good collection having been obtained, they seemed 
clearly to establish the Cretaceous age of the formation. Dr. Newberry 
thought them of nearly the same age as the plants of the Amboy clay, 
which are middle Cretaceous. Concurrent views were expressed by 
Ward, F. J. H. Merrill and Heilprin. 
Mr. J. S. Diller made a communication on "The Sandstone Dikes of 
the Forks of Cottonwood creek in Tehama and Shasta counties, Cali- 
fornia." This was well illustrated by diagrams on a large screen. 
The dikes do not generally reach the sui'face. They are transversely 
bedded, and in other features of their mode of occur ranee, not less 
than in their petrographic character, difier from proper dikes. The 
author suggested that the fissures were the result of seismic move- 
ments, and that the sand was squeezed in from below. 
Mr. A. S. Bickmore, superintendent of the Museum, presented on 
the screen some "Illustrations of the glaciers in the Selkirk mountains 
and Alaska." These were magnificeut and novel views. 
Dr. Alexander AVinchel! preseiited a condensed oral abstract of a 
memoir on "Some results of Archa'au Studies." The district to which 
attention was chiefly directed was northern Minnesota and contiguous 
regions in Canada, but he brought to bear on the discussion, the re- 
sults of studies in the original Huronian region of Canada, in Michi- 
gan and in Wisconsin. He recognized four series of older rocks in 
chronological succession. 1. The granitoid rocks. 2. The gneissoid 
rocks (only less altered than the granitoid). 3. The crvstalline schists 
("Vermilian series). 4. The semi-crystaline schists (Kewatin series). 
5. The uncrystalline schists (Anim'ike). The Archaean regions de- 
scribed are divided into oval or elongated granitoid areas bounded by 
quaquaversally dipping schists of the various ages, synclinally folded 
along the belts separating the areas. AccomT)anied by numerous il- 
lustrations. Discussed by Van Hise and A. Winchell. 
Professor C. H. Hitchcock made a conmiunication on the "Signifi- 
cance of granitoid areas in the Laurentian," in which he described 
several occurrences in New England quite similar to tliose described 
from Minnesota and Canada, and seemed to convey the idea that these 
rocks presented only a case of greater or less degrees of metamorphism. 
Professor G. H. Williams stated that the same facts produced an oppo- 
site impression on his mind. The granites and gneisses seemed 
unquestionably eruptive. 
Professor B.'K. p] in er son made a communication on "Porphyritic 
Granite," and Dr. Lawson one on "Tlie internal relations and taxono- 
my of the Archtean of central Canada." He recognized two great 
systems in the Archa>an. The Lower (or Laurentian) is composed of 
plutonic, igneous rocks; the Tapper, of indubitably normal surface 
rocks, variously altered. The lower he regarded as of younger age. 
A memoir by Sir William Dawson andD. P. Penhallow, of Canada, was 
read in condensed abstract, "On the Pleistocene Flora of Canada," and 
Mr. W. Upham read a paper "On the fiords and great lake basins of 
North America considered as evidences of preglacial continental eleva- 
tions and of depression during the glacial period;" and Dr. James 
Hall made a communication "On the genus Spirifera and its inter- 
relations with the genera Sinriferina, Syringothyris, Cyrtia and Cyrtina. 
