112 PROCEEDINGS OP THZ JTKW HAYEX MKKT1 



Bowling Green limestone. Xoix oolite and Channahan limestone are considered 

 members of tbe Edgewood limestone, representing local facies of this forma- 

 tion. The several formations are unconformable among themselves, bnt their 

 faunas are closely allied. They are thought to hare been deposited in an 

 oscillating sea that advanced successively from the south, the sediments of each 

 succeeding advance overlapping those of the preceding. The basin in which 

 they were deposited was a rather narrow extension of the Gulf of Mexico 

 embayment toward the north and northeast. During Edgewood time this de- 

 pression was deepest near the west side, having a longer and more gentle slope 

 toward the east. The name Thebes Basin is proposed for this general area of 

 sedimentation during Alexandrian time. 



The faunas of the Girardeau and Edgewood limestone are figured and 



The next paper was read from manuscript: 10 niin::- I - -s^d by 

 Rudolph Buedeniann. Eliott Blackwelder. E. S. Moore, Ghestei 

 Beeds, Gilbert Van Ingen, and G. B. Wieland. 



WOTES OX THE ORIGLX OF CERTAIX UPPER CAJIBBIAX AXD LOWER 

 ORDOTICIAX SEDIMEX7 7 7ESTEM 7 77 _I1 ^TLTAXIA 



BT THOMAS C, B»: 



Atstrwct) 



In the central part of Center County, north and weal : ^:ate College. Penn- 

 sylvania, are exposed a series of Paleozoic sediments of Upper Cambrian and 

 Lower Ordovician age. They consist of two series of limestones separated by 

 a few hundred feet of sandstone. The limestones are in part oolitic and in 

 part composed of pebble-like structures, to which the name "'Edgewise eon- 

 glomerate" has been applied. Chert bands are numerous, and many of the 

 oolitic layers have been almost completely replaced by silica. The sandstone 

 consists of extremely well rounded sand grains, which indicate a peculiar 

 origin. 



In certain of the limestone layers are peculiar disk like structu res which 

 in their section show a banded or concentric structure and which were prob- 

 ably produced by calcareous algae. Their position in certain beds proves that 

 they could not have been produced as clastic structures. Tbe structures of 

 the sandstone and the nature of the component grains indicate a wind-blown 

 origin. 



The following paper was read by title : 



SPIRIFEROLD8 OF THE LAKE MTXXEWACKA BECTIOX. ALBERTA 

 BT H. W. SHTME* 



strict) 



Fossils are extremely abundant in this area. Brachiopods are especially 

 conspicuous, and of these the spiriferoids exceed all others in number of indi- 



* Introduced by R. S. Bassler. 



