i8o Ulrich on Corre!ati07i of the Lczver Siluriafi. 
the rains wash out the chert and fossils. The hitter arc in a 
beautiful state of preservation and belong to numerous species,, 
the Gasteropoda being the best represented. 
The best exposure of this horizon seen was found in a cut 
along the Cincinnati Southern R. R. at a point about one mile 
and a half south of Burgin, Ky. Several good exposures were 
also met with in the vicinity of Lexington, Ky. 
The following is a list of the principal fossils: 
Buthotrcpliisf succuJetis Hall. Miirr/iisoi/id fulc/ira McCoy. 
Styomatoceriiiui -pitstulosum Safford. '' stimuerciisis Safford. 
Phylloporiua granistriata Ul. Holopra ohliqua Hall. 
Off his /(s/ucliii(iria{\'e\-y thin form) Cyclora dcpycssd ? Ulrich. 
Zygospira recurvirostris Hall. " minuta Hall. 
Rliynchonella increbescens Hall. " par-'ula Hall. 
Belleropho)! troosti Safford (Rare.) Aiiihoiiyc/iia iutcrmcdia M. and W. 
" socialis n. sp. l^fllinomya sp. closely related to T. 
" lindshyi Safford. lursuta Hall, but larger and 
" acuta Sowerby. higher. 
(yt/olittrs oritatus Conrad. Cypricardifcs -vorllicvi n. sp.' 
Mctoptoma !C)i<ri<la n. sp. " liaynina Safford. 
Pleurotoinaria {Raphtftoma) suhtili- Mathcria tetter Bill. 
striata Hall. Alodiolopsis iiais Bill. 
Pleurotoiiiuria n. sp. a. Cotiocardiutii iitiiiiaturnitt Bill. 
Murchisotiia gyrogouiit McCoy. Dahttatiites callicephalus Green. 
Beds X. To these Mr. Linney has applied the provisional 
name "Upper Birds-eye beds." They have a maximum thick- 
ness in Mercer and Boyle counties of about t\venty-fivc feet, 
and consist mainly of firm, light or dark dove-colored limestones, 
in from one to two feet layers, with some of them separated by 
thin seams of shale. Toward the top the layers are hmipy and 
change in color into gray and then bluish, showing also signs 
of slight disturbances. The uj^permost layer is generally dis- 
tinguished by the large masses of StroiuatoccriitDi ( FLabcc/tia) 
piistulosuni Safford, which abound in it, while the two or three 
feet below it contain numerous compressed valves and com- 
plete shells of Orthis borcalis Billings, and RhyiicJuynella in- 
crebescens Hall. The dove-colored layers, in their comjoact 
textin-e and "Birdseye" structure, closely resemble those de- 
scribed in this paper as beds III.- Some of them, the darker 
ones in particular, hold large numbers of Leperditio and Jsoch- 
' This name is proposed for the shell of which an internal cast is figured 
and described in vol. iii. of the 111. Geol. Sur^-. p. 311, plate 3, figs 9«- 
()d. .Several fine specimens have been obtained from these beds. 
