3 1054 The Materials of the Appalachians. [Dec. 
other places is not only directly disproved, but is quite unneces- 
sary in order to explain the sudden disappearance of the Great 
Northern Sea-Cow from the shores where it was first discovered. 
I think it will be admitted that we have succeeded in materially 
strengthening Sauer’s assertion, that the Rytina was exterminated 
in 1768, and that the above is a fair exposé of the causes which 
led to its final extirpation. It was simply due to man’s greed, 
and he accomplished it within the short time of twenty-seven 
years. 
THE MATERIALS OF THE APPALACHIANS. 
BY E. W. CLAYPOLE. 
(Concluded from page 962.) 
THE Four GREAT SANDSTONES OF PENNSYLVANIA. 
the former part of this paper I dwelt on the fact of the 
existence of several thick sandstones and quartz conglom- 
erates in the massive palzozoic deposits of Pennsylvania. I 
further showed that these rocks indicate a supply of quartz far 
greater than could be furnished from any existing source; aM 
thirdly, that the nature of this quartz is such that the ad 
known origin for it is the quartz-ledges of the South Mountains. 
Hence I inferred the former extension of these strata over å 
greater extent of country than at present. 
In this second part I propose to try and give a more 
shape to this conclusion, and to at least suggest where an 
this palzozoic land existed. 
definite 
dwhen 
to mention, the Potsdam Sandstone, there remain Tour er 
sheets of sandstone, more or less conglomeratic, rt 
mensely thick palæozoic deposits of the Eastern States, 
ale, cost MMM a ss cca venooe choos mend 
4 Sandstone and pebbles (Pottsville Conglomerate)....--- 
Shale (Manch Chaski... u.. serer aterrir E aa 
.. 
MEE a iaa 
