INTRODUCTION. 



According to the views of the American geologists, the Devonian formation in the State 

 of New York admits of subdivision into the following minor groups, in ascending order: 



I. ORISKANY SANDSTONE. This group consists essentially of coarse siliceous sand- 

 stones and sands, sometimes more or less calcareous, sometimes argillaceous, and often con- 

 taining nodules, layers and seams of chert. In its greatest development in the State of New 

 York, the Oriskany Sandstone has a thickness of no more than thirty feet ; and it is highly 

 fossiliferous. According to Sir William Logan (Gwl'Hiy of ( p. 360,) the Oriskany 



Sandstone enters Canada at Waterloo, on the Niagara River, and can be traced westward as 

 far as the Town-hip nf \Vindharn. It does not differ much from the Oriskany Sandstone of 

 the State of Xew York in its litliological characters, except that it is u-ually more highly cal 

 c ireous. and in pla* . genuine though impure limestone. Its usual tliick.ni' i-.>nly :il>out 



MX feet, though sometimes attaining to as much as twenty-live feet; andit is often altogether 

 wanting, when the Corniferous Limestone reposes directly upon the underlying Lower Helder- 

 berg formation. 



The exact age of the Oriskany Sandstone cannot be said to be altogether tree from doubt. 

 No mechanical break separates the Oriskany and Lower lleMerber.: deposits, and the differ- 

 ence which i.i observable in the faun;-- ot' tin- two <_Toups is not -renter than might IK- well 

 accounted for by tin- litholo^ieal ehaii'_ r e from the highly oalcareoos aooamulationB of die latter 

 to tip- ; meats of the former period nn the other hand, the <>n-km\ Saml 



Htone iu tip- St-ii- of New York i- . led above by an alimt DOD-foasiliferoajB dej-iisit, the 

 80-callnl ( '.iiiila-l'Jalli lirit," whieh -radiia'.-- in-enM'bl\ into, and form- tlie -eolo-ieal I 

 of. tin- lo-ilif'Toii- Srboharie (u-it." l'|.cm the wh>le. BO tar U tlie State of N, w V^rk. \* 

 eone.-rn.-d. tln-r.- can tic little he-it at ion in aeeepting tip' \ i- \s - ..!' 1 'rot'. --M-r. I a IIP-- 1 1 all, who would 

 ml tin- < >ri-kanv Saml>tm- rather as tin- Mimmit lie.l ol'thi- Silurian li-. 1 ba>e 



iii'-nt !"'! of tl. I 1 . .'lian. Qpon this subjeot, the above-named distingaiehed >t thus 



-Xj ini-'-lf \Vhatr\iT may be t IP- ultimate decision relative to the HIM- <' "ion 



b'-twc. n tin,- Silurian and I>rvoiiiai) BJfltemB, ilir lia-i- o!' the Seholiarir ( irit otlVr- a niueh more 

 :'l.-il liiiiilation b.-l-.w, tlian doefl ill" 1 < ri~kany Saipl-toni-. Tlir n.-w 1'iuna bear- le-.- rel:\ 

 lion in the pi-'-eeiliiiL', ami in anv of tin- IP-W typOfl are of a .-trikiiiu'ly li>tmet eliaraeter In 

 tin- ( iri-kany Sanl.-tione, w.- have a emi-i'l. rahle numb, r ><!' -| A iiieh !ir>t appear in th- 



l.owr lli-1'lerber- (Iroiip , ami the "'inin-etii.ii b.-lwe. n the-. |', ,i mat i"ii- is mueh IIPT.' intin 

 than b. twi-.-n tin- ( )ri-kan \ Saml-toiie an. I the Selmharie (I 

 I'ol. II 



With p'-anl to ihe -.. ealled " ( Iri-k.ois Saml-t.m.- o| 'I'ana.la, the , .'inewhat 



JitFerent. Tlie abnmlant t'.mua ulii<-h it conl.nn-i i- bin -li-hl,, i totliat ..I' tin- 



