332 The American Geoloijist. November. 1896. 
bly weighs 1,100 or 1,200 lbs. A large area of its upper or exposed sur- 
face is fairly vvell-siuoothed and striated. As at one place upon it there 
was a tendency to peel. I was able to knock off a small specimen, a part 
of which I have the pleasure to send you herewith. My reasons for be- 
lieving that this boulder is a genuine glacial-jjcriod one, and nearly in 
place, may be stated thus: 
1. In composition it is much like other erratics found north of the 
moraine as mapped by the Second Geological Survey of Pennsylvania. 
2. It is in just such a position as erratics occur and are commonly 
seen in typical boulder-areas. 
3. As above stated it bears marked evidence of glacial smoothing and 
scraping. 
4. It is similar to other boulders in shape and form, namely, rounded. 
5. Unlikely to have been derived from the bed of coal (the '"Pitts- 
burgh bed"), or its associated strata, which outcrop about 24 feet above 
the site at this place, and where there is a coal mine in operation : be- 
cause most erratics found in or in contact with coal are stained black on 
the outside, while this one is not. Moreover I have never heard of a 
granite boulder having been found in the coal measures of western 
Pennsylvania, though I have seen one of limestone in the 10-inch bed of 
fireclay dire(;tly overlying the workable portion of the ''Pittsburgh" 
bed at the Guffey mine about 20 miles to the south of Woodville ; and 
possess (me, of quartzite, that was taken out of the "Mammoth" bed 
of anthracite at Mount Carmel, Pa. 
6. Such boulders are never shipped (at least I never heard of such a 
thing) in freight or coal cars, especially to coal-mines located in the 
country. Such a stone as this one would be very awkward to handle 
into a car, and I can conceive of no purpose or object in shipping such 
a thing at all excepting possibly to a museum. 
The stones in the stream where this granite boulder was observed ap- 
peared to be all of coal-measure origin, namely, — limestone, sandstone, 
iron ore, grit, black slate, etc. The elevation of this boulder would be 
about 800 feet above tide level. The nearest erratic, (a small, smooth 
boulder composed of dark greenish, very hard, volcanic rock,) I have 
met with to the north of this red granite boulder, was on a hill side at 
New Brighton, Pa., a locality also several miles south of the line of the 
great moraine as mapped by the Penu. Geol. Survey. 
This boulder therefore shows that the southern margin of the glacial 
moraine, as mapped in southwestern Pennsylvania, should be extended 
some 25 miles south, in that region. W. S. Gresley. 
Erie, Pa., Sep. 30, 1896. 
Mr. Sardeson and Fossil Tabulates. In the July number of the 
American Geologist, Mr. Sardeson does me the honor to reply to a 
critique of his paper, " Ueber die Beziehungen der fossilen Tabulaten 
zu den Alcyonarien." The fact that he there adduces one misstate- 
ment made by me and alleges others, seems to call for some notice on 
my part. In general, I wish to assure Mr. Sardeson that the unnamed 
