LOWER SILURIAN SYSTEM OF EASTERN MONTGOMERY CO. 459 



E^ Medium bedded in the lower layers, dark 

 blue, fine grained limestone becoming thin bedded 

 and shaly in the upper part. Contains large 

 numbers of Trinucleus concentricus 

 Eaton, and Monticulipora (Prasopora) 

 lycoperdon Say. i8'=i 10' 



E^ Soil filled with boulders. 30'= 92' 



E^ Thin warped layers of arenaceous limestone 

 weathering buflf. Calciferous sandrock. 7'= 62' 



E^ Heavy, very compact layer of sandy lime- 

 stone. 3'= 55' 



E^ Partly covered. Sandrock exposed in bed of 

 creek near railroad. 52'= 52' 



No. 3 of the above section is doubtless the thin bedded member 

 often occurring at the summit of the Calciferous stage. Perhaps 

 the 30 feet belong entirely to the Trenton stage. The thin layers 

 of no. 5 are excellently adapted to collecting fossils and contain the 

 two representative species of the upper Trenton of this region in 

 abundance. A short time was spent in collecting at this point with 

 the following result: 



1 Monticulipora (Prasopora) lycoperdon Say (c) 



2 Stictopora acuta Hall? (r) 



3 Rafinesquina alternata (Con.) Hall and Clarke (c) 



4 Orthis (Dalmanella) testudinaria Dalm. (c) 



5 Rhynchotrema capax (Con.) Hall and Clarke? (rr) 



6 Modiolopsis cf. arguta Ulrich (rr) 



See Geol. surv. Minn. v. 3, pt 2, pi. 36, fig. 6 



7 Asaphus platycephalus Stokes (c) 



8 Leperditia fabulites Conrad (r) 



9 Trinucleus concentricus Eaton (a) 



10 Raphistoma cf. lenticular e Emmons (rr) 



11 Crinoid segments 



Westward from this point the Calciferous is well exposed along 

 the railroad, and an excellent section from the Calciferous to the 

 Utica is aflForded by the small creek half way between Crane's vil- 

 lage and Port Jackson. The exposure of the Trenton in this sec- 



