Geology and Mineralogy. 471 
that the above facts may have an important bearing upon some 
evident geological phenomena, but does not discuss the matter 
further. A series of concluding tables shows in detail the behav- 
ior of a large number of minerals with citric acid alone and with 
reagents, 
II. GroLtoGy AND AMimeancoee. 
a On Pot-holes on the edge of a bluff at Aes cle 9. Connecti- 
;_by Professor B. F, Koons. (Communicated.)—Last Novem- 
e I discovered an interesting group of pot-holes ccs the edge 
of a bluff at Gurleyville, Conn., on the east side of the Fenton 
River, four miles above its mouth, 
Recently, i in company with Professor Washburn, F have oo 
the one perfect one of ‘its water and stones, and found it to be 
six feet seven inches in depth, three feet nine Teas in its 
Shorter diameter at the top, and four feet three inches in its 
longer diameter. 
About two feet above’ the bottom the diameter is reduced to 
about thirty inches, and then widens again below a point, leav- 
ing a horizontal ring at the narr ow place. What can have been 
the cause of the forming o the ring at this point is pe entirely 
evident. If the rock were horizontal it. would seem that a hard 
hi in the rather uniform gneiss would account for it ; but since 
the rock dips at an angle e of about 30°, and this projecting ring 
is pl and only a couple of in nches thick, I find myself 
ata 2 for an entirely satisfactory an 
ot-hole is near the edge of ste lift and the remnants of 
3 Agricultural School, Mansfield, Conn., pee 2st, 188 
Sain Ah of Pike and Monroe C sat Pennsyloania 
by. - Warre; and Special eg of the Delaware con 
Lehigh Water Gio, by H. M. Cuance.—The publication of t 
volume of the Geological sage ‘of Pennsylvania is anuodnoed 
on page 310 of this volume. and Monroe Counties are on 
a 
treats of many points of great interest, with a full supply of facts 
from his careful observations. 
front or eastern edge of the great plateau of the two 
