211 



Ft. In. 



■25 — Limestone. Dalmanella (aa) Bryozoa. Fragments of Rafinesquina 1 3 



24 — Shale with thin layers of Bryozoal limestone 4 



23 — Bryozoal limestone with some shale 4 4 



22-Shale 2 2 



21 — Limestone with Bryozoa and Zi/gospira 5 



20— Shale 1 2 



19 — Bryozoal limestone 4 



18— Shale 10 



17 —Thin layers of Bryozoal limestone 1 9 



t6-Shale 1 6 



15 — Two four-inch layers of Bryozoal limestone 8 



14-Blue shale 5 4 



13 — Bryozoal limestone 6 



12 — Mostly compact Bryozoal limestone 5 



11 — Coarse crystalline Bryozoal limestone 10 



10 — Covered, probably shale 5 6 



9 — Limestone and shale. Dalmanella 2 6 



8 — Layers of limestone with Dalmanella Bryozoa, etc 1 



7 — Covered, probably shale 2 2 



6 — Compact limestone with Dalmandla. Lower part consisting of 



sandstone 8 



5 — Covered 5 6 



4 — Limestone with Rafinesquina (aa) 6 to 8 



3 — Shale 5 (5 



2 — Dalmanella layer 



1 — Covered to river level 140 



Total section 385 



The Platystrophia beds are to be seen about Mt. Sterling and in the banks of the 

 east branch of Indian Creek. They reach the bed of the creek two miles north- 

 west of the former place. In the bed of the creek just west of Mt. Sterling the 

 zone of Dabnanella is exposed and extends up the creek for a mile and a half. 

 Here it is succeeded by the Rafinesquina zone and then by the P/ati/sfropliia zone, as 

 stated. One mile northwest of Bennington along the road the zone of Rhijncho- 

 trema capax is exposed, and between the latter place and the Piulyslrophia zone are 

 abundant exposures of the upper zone of Rafinesquina. Large collections were 

 obtained from all of these zones and await description in another pa])er. 



The Ordovician and Silurian rocks of Madison, .Jefferson County, Indiana, 

 have for many years been the subject of more or less detailed study by geologists 

 and paleontologists. The sections of the Madison hill in tlie railroad cut as 

 given by Owen and Borden* are certainly far from being accurate. Tiie writer 



■■'Geol. surv. Intl., 1874, E. T. Cox; pp. 164-16(i. 



