192 GEOLOGY OF OHIO. 
The insufficiency of the evidence upon which the conclusion is based 
that the Sandusky limestone belongs to the Hamilton group will be seen 
from the range of most of the fossils which form this evidence. For ex- 
ample, Cyrtia Hamiltonensis is found throughout the Corniferous, Hamil- 
ton,and Chemung. The same is true of Atrypa aspera. Atrypa reticularis 
ranges from the Clinton tothe Chemung. Althyris spiriferoides is found 
throughout the Corniferous and Hamilton groups. I should also say that 
Cyrtia Hamiltonensis occurs in abundance at Sylvania, at the very base 
of the Corniferous group, and I have well-marked specimens from that 
locality obtained by Mr. Gilbert in limestone that was somewhat inter- 
stratified with the Oriskany. 
This subject will be found discussed more at length in Vol. L., Part L, 
pp. 144-149, and the reader is also referred to the reports on Delaware and 
Paulding counties by Prof. N. H. Winchell, contained in this volume, and 
to that of Mr. S. K. Gilbert on Lucas county, Vol. I., Part I., p. 576. 
The fossil fishes of the Corniferous limestone have attracted more or 
less attention from geologists for many years. They are now chiefly ob- 
tained from the quarries on Kelly’s Island and Marblehead, in the 
Lower Corniferous limestone; in those of Sandusky and Delaware, from 
the upper member, or Sandusky limestone. My attention was first called 
to them by Dr. E. 8. Lane, of Sandusky, as early as 1850. Since then a 
great number of fine specimens have been obtained from the Sandusky 
quarries by Dr. Lane, Dr. A. H. Agard, and Mr. L. P. Wheelock. These 
represent quite a number of genera and species, which are figured and 
described in the paleontological portions of this and the preceding vol- 
ume. The following is a list of such fossil fishes as have been found at 
Sandusky and on the islands : 
MacropetalchthysiSulllivanticcsensscccecaseelestscoees cco setetstessteanscebeslossscc: Newb. 
(OSORIO OOCGUNSS, STFEATOVOS IC LEIS) cogoqn6d0 696500006 600009000 633000000 4118600 1105000005 000006 00000 :990.065 
IWIGYO) NE er es yer oN A MES} wOTEN (OLY Baceeg cas6d0000 edodss 650060800 600500000 430006008 600800000 603000000 
M. OST AKOLUURDSSS Gaadadauo OunonNGo0 668505006 dad0d0 640000 B40d0d000 Gond00 HGK060900 
M. BUILCALUS  cavacscse ccccconcsreesecccanecvceslectscleneccenoceumcmcedocnene neers 
Rb ynCHOdUs) PANSEUB es -.ccsesecosececeisoeserers scesesinecnetecelecnrelece ssa] eeeeledncternes 
R. SCCATAS IN. Ses caeehsceree recess odtivedcesiee steamer enoceese eecoem toate meee: 
R. (ChE ES acici0g pao uCogUOOCHELU BOSO0H), HOBCIO0G CONG00000 40000500 cbadae coLIDOsOON 
Alsterosteus) Sten Ccephalupics.ccdesccccstlovsdecceslecvensessieecnsreesicenesncentoousionee 
INGENOIA DENS} OS) ENEOTENIDIS) _G5c000 690000 600060000 030060000 650600 65000006 900000009 050000 Eod00000C 
JAG aN I ONE) SIE OWE O CSTE 55000 God000 039000000 000009000 400000 00002550000 540080 080000 CADI0 
Of these, the first two are the most common and conspicuous, and will 
be recognized from a few words of popular description by all who have 
seen collections of fossils taken from the Sandusky limestone. 
