IN THE RED SANDSTONE OF POTTSVILLE. 
13 
subglobular forms, which may possibly be the ejectamenta or coprolites of some of the 
animals that passed over the shores of these waters. 
Another of the specimens which I obtained at the same time, contains the remains of 
a portion of an organic form, which I cannot with any satisfaction make out. It is pro¬ 
bably a very small portion of the whole organism, as it forms only a short, curved, ser¬ 
rated line of an inch and half in length. (Fig. 1.) I cannot compare this serrated line to 
any like form, but that of the serrated edge on the side of the Olenus asaphoides , of Hall’s 
Palaeontology, (part 4, pi. 67, fig. 2,) and Asaphus Buchii, in the Llandeilo Flags, (Silurian 
Syst., pi. 25, fig. 2,) in which the serrations are, however, more pointed. Mr. Hall’s speci¬ 
men is from the Hudson River Group, Formation No. 3, of the Pennsylvania Report, a 
period far removed and earlier than Formation 11, inwdiich this specimen was found, 
near to Pottsville. The serrated edge of Ellipsocephalus Hoffii , Zenker, in Burmeister’s 
“ Organization of Trilobites,” (p. 74, pi. 1, fig. 8,) approximates very closely, in outline, to 
our figure. 
In 1834, Mr. Taylor communicated to the Geological society of Pennsylvania that he 
had observed “ at least two nondescript species of Fucoides in the Old Red Sandstone of 
Tioga county, Pennsylvania.” (Transactions, vol. 1, p. 175.) And he subsequently ob¬ 
served obscure impressions of plants in the same formation, near to Pottsville, at Tum¬ 
bling Run Dam. This obscure vegetation has been observed also by others, and there 
are now specimens in the collection of the Academy of Natural Sciences of this city. 
The red sandstone rocks of this period present frequent and marked instances of cracks 
caused by dessication of the mud which opens into irregular fissures, which, on return of 
the tide, were probably filled up by sand, thus sometimes furnishing a tissue of meshes of 
various sizes, the interspaces being sometimes as great as three feet. A very remarka¬ 
ble one of this kind may be seen at Dauphin, near the Susquehanna, above Harrisburg, 
in this red sandstone, underlying the coal measures of that part of the same basin. The 
surface of the rock exposed there with these sun-dried sand-cracks, must be quite thirty 
feet, and some of the cracks were nearly a foot across. 
