1395.] | Geology and Paleontology. 369 
while this group is widely represented in West Europe, Asia and 
America. 
(4) The close resemblance between the Mastodons of Eur-Asia and 
America confirms once more the connection which exists between the 
two continents during the Tertiary period. (Bull. Soc. des Naturl. 
Moscou, 1894, No. 2.) 
Geological News.—Paleozoic.—In a paper on the Potsdam 
and calciferous formations of Quebec and Eastern Ontario, Mr. R. W.. 
Ells submits evidence to show that the real line of division between 
the Cambrian and Cambro-Silurian systems should be placed at the 
close of the Georgia slate and red sandrock divisions, and that the ser- 
ies from the base of the typical Potsdam sandstone to the summit of the 
Utica and Hudson River formations should constitute the system known 
as the Cambrian-Silurian or Ordovician, in view of the fact that there 
is no stratigraphical break in the sequence of these formations, nor any 
want of harmony in the succession of organic life as furnished by the 
evidence of the contained fossils. (Trans. Roy.Soc. Canada, Section 
IV, 1894.) 
The report on the Insect Fauna of the Rhode Island Coal Field, by 
Dr. Scudder, is published as Bulletin No. 101 of the U. S. Geol. Sur- 
vey. The collection is an unusually interesting one, as all the species, 
without exception, are new to science and unknown elsewhere. They 
consist of Anthracomartus, the first discovered Arachnid in the Car- 
boniferous deposits in the eastern United States; a new genus of Neu- 
ropteroidea and one of Protophasmida allied to some from the Carbon- 
iferous beds of Commentry, in France ; and a number of cockroaches, 
represented only by their wings. These last show great variety of 
form. The two subfamilies of Palaeoblattariae are represented by ` 
three genera, including nearly a dozen species. 
Mesozoic.—Various offices have been attributed to the Aptychus, 
but the recent discovery of an Ammonite (Oppelia subradiata Sow.), 
from Dundry, now in the British Museum, with the Aptychus in situ 
closing the orifice, would seem to disclose the true nature of that body, 
viz. that of an operculum. In view of this fact, Professor E. H. L. 
Schwarz shows how all the theories against its use as an operculum can 
be met with equally plausible ones in favor of that view, and throws 
the weight of his opinion in favor of such use. (Geol. Mag., Oct., 1894.) 
A large Clypeastrid is reported from the Cretaceous formation near 
Colorado Springs, Colorado. Upon examination, Mr. F. W. Cragin 
