2U7 



8 — DinoTthis subqiiadrata (a). 



7 — Heberteila occidentalis (a). 



6 — Raiinesquina, Streptelasma, Plal)/s(iophia, L(pt(f'na. 



5 — R'lfinesquina, Monticulipora. 



4 — Dalmanella (shaly limestone). 



3 — Rapnesquina. 



2 — Asaphus, calymene. Rafinesquina. 



1 — Rapnesquina. 



Rafinesquina remains the dominant fossil for some distance farther down the 

 ■creek, where its place is taken by the several varieties of platys'rophia biforata. 



No good sections of the Ordovician are to be found in the vicinity of Rising 

 Sun. Numerous exposures of the various members may, however, be seen at a 

 number of points. These exposures show that the lower members are, as in the 

 other localities already studied, characterized by the great abundance of Dalma- 

 nella and Pleclambomtes. These fossils are succeeded in the beds next above by a 

 number of species of Trepostomata, which in places completely fill the rocks. 



.\bove the Bryozoa beds Rafinesquina alternata becomes abundant, though 

 of course occurring in limited numbers at almost every level. Next fol- 

 lows the zone of Platystrophia biforata and its varieties. This is in turn succeeded 

 in the tops of the hills by a zone in which a varietal form of Rafinesquina alter- 

 nata is abundant, to the exclusion in places of almost every other fossil. The 

 higher zones are not pre^ent in the vicinity of Rising Sun. 



Vevay, in Switzerland county, is one of the best localities in the State for 

 the collection of Ordovician fossils, and especially of the various forms of Platys- 

 trophia. Two detailed sections were measured at this place. These are desig- 

 nated A and B. Section A begins at the head of Main Cross street and extends 

 up the little gully just east of the Orphan A.«ylum. 



This section (A) is as follows (i; 1, 38 A.) : 



Ft. In. 



87— Covered to the top of the hill 80 



86 — Limestone with Flatystrophin and Heberteila 6 



85 — Yellowish argillaceous sandstone 4 



84 — Thin-bedded limestone containing P/a<i/s<?'opA(« and Heberteila.... 12 



83 — Platystrophia biforata 6 



82 — Yellow sandstone 4 



81— Covered 3 3 



80 — Argillaceous arenaceous limestone 4 



79 — Some covered, mostly thin layers with Rafinesquina 14 



78 — Limestone with Rafinesquina and Bryozoa. 5 



77— Covered 3 8 



76 — Compact limestone with Rafinesquina 4 



