193 
PERSONAL AND SCIENTIFIC NEWS. 
The Geological Society op America held its summer ses- 
sion at Rochester, N. Y. , on Monday and Tuesday, Aug. 15 and 
16, 1892. The president, Mr. Gr. K. Gilbert, presided. The 
first paper, by Mr. Lawrence Johnson, treated of the phosphate 
beds of Florida and their geological historj'. In his opinion 
Florida began by the rise of a number of small islands of P]ocene 
rocks in a shallow Miocene sea, and on these rocky islands, guano 
was deposited by birds, while marl beds were at the same time 
formed in the narrow channels. He attributed the origin of the 
"pebble phosphate'' to the disintegration of these Miocene marl 
beds after elevation. After alluding to the vast erosion which these 
rocks have suffered, the author divided the phosphate beds into 
four groups, successively formed : 
(o) "Compact Rock," phosphate, 
(b) passing into "Laminated Rock, " 
(c) then into "Plate Rock," and 
id) lastly into "Soft-Phosphate." 
In the absence of the author little discussion was possible, but 
some objection was raised against the origin attributed to the 
phosphates, inasmuch as the fossil remains indicate marine con- 
dition and exuviae rather than terrestrial. 
The next paper. Prof. E. W. Claypole's, on the Dentition 
of Titanichthys and its allies, after paying a high tribute to the 
skill and pains of Dr. Newberry in so ably interpreting the first 
remains of the kind that came to light from the Ohio Devonian 
strata, and expressing the regret of the society that ill-health de- 
tained him from the meeting and from the prosecution of the 
work, described the detention of the Dinichthyidie as already 
known, pointing out the peculiarities of the teeth of the different 
genera, and then brought forward some recent discoveries by Dr. 
Clark of Berea, which led to the belief that at least two interman- 
dibular plates or teeth existed in some or in all the forms, and 
whose presence explained or removed several difficulties that pre- 
viously presented themselves. One intermaxillary, scalpri-form 
tooth was also present in the upper jaw, between the two great 
"pre-maxillaries" of Newberry, which apparently worked against 
the two alread}' mentioned, in the lower jaw. These additions 
considerably simplify the mechanics of the jaws of these monsters. 
Prof. C. H. Hitchcock followed with a paper on the Connecti- 
cut valley glacier. He quoted several cases in which striae from 
the north crossed others previously made from 30° west of north, 
and stated that the latter, in such cases, occupied a slight hollow 
at the bottom of a basin or trough. He thought that this indi- 
cated a change in the direction of the ice and that during the 
greatest extension of the glacier, when drainage was almost im- 
