■64 Correspondence. 
number of large, flat, pavement teeth of type hitherto unrecognized, and 
(3) a number of slabs showing teeth and finrajs of cladodont fish. (4) A 
C/c««crtW^//«A' spine, associated with dermal ossicles; (5) coprolites, and (6) 
some nearly entire and one entire palaeoniscoid fish. All these are from 
the black base of the Cuyahoga shale (Berea shale of Orton) a bed that 
has hitherto yielded little besides Liugula and Disciiia. 
E. W. Claypole. 
Cleveland, Ohio, May /j", iSSS. 
Mr. J. S. Diller of the U. S. geological survey has kindly sent to me, 
for comparison with the Nebraska deposits described by Prof. Aughey, 
the following specimens: 
Slide No. i. — Volcanic dust from the eruption of Krakatoa, collected on 
Italian man-of-war Adriatico, 200 miles south of Java. 
Slide No. 2.— Dust collected bv Prof. J. E. Todd, Knox Co., Neb. 
Slide No. 3.— Dust collected by Prof. J. E. Todd, Seward Co., Neb. 
Slide No. 4. — Dust collected by Col. Sizer, Phillips Co., Kas. 
Slide No. 5. — Dust collected by J. A. Udden, Lindsberg, Kas. 
I find no important constant difference between the undoubted volcanic 
dust and the other slides 2, 3, 4, and 5. No. i is somewhat finer and con- 
tains more granular and fibrous particles mingled with the thin flakes 
which constitute the unique feature of all the specimens. 
An important point of resemblance is that these flakes, although so 
thin, have air-bubbles inclosed in them. These are spherical, oval, spindle- 
shaped, narrowly elongated, &c. I found them in all but the Lindsberg 
specimen. 
Nos. 3 and 5 contain diatoms. 
The presence of air-bubbles favors the theory of volcanic origin. How- 
•ever, I regard the question of origin as not absolutely settled until the 
stratigraphy of this dust stratum and the associated strata has been 
thoroughly Avorked out in the field. This stratum may prove to be an 
important datum plane for the correlation of other strata. 
L. E. Hicks. 
In the American Geologist for April, page 25S, in a notice of N. S. 
Shaler's preliminary report in sea-coast swamps of the eastern United 
States it seems to be inferred that the beaches along the southern shore 
of Long Island are the result of marine action. If so, this is far from 
being the fact, as the truth is, these so-called sea beaches are being worn 
.away by the waves rather than being formed by them, as the sea is 
yearly gaining on the land. Several years of careful study of the drift 
phenomena of Long Island by the writer, led to this conclusion that these 
beaches were formed by sub-glacial currents and not by the sea as has 
been supposed. Streams issuing from the front of the glacier laid down 
the stratified deposits of the south side of the island and it will be noticed 
that these southern projections of land, or beaches, are always the most 
prominent where the floods were the greatest. For instance at Fort 
