]() 'lili; ICK .\(ii; IN ( A.NAhA. 



roasts wniiM raisi' the ti'iiipcrni mi' nf tlicii' watcrx. Any 

 t'liiiii^c lluit wniiM iilldw ilir ('(iiiiiidii;!! cin'reiit III |iiirsii(' 

 its ('((iirsc tliriiii;4li to the I'iicilic or almii; the ureal inland 

 vallt'V III' N'ni'lli Anirrira, wmilil rriliHc tlir l'>rilisli seas !(► 

 a liin'ral ('ninliiinii. 



"'I'lir liiiiililrr t'liruial imi anil ils uNrriyinL!, I'lissiJitcriins 

 IumIs |iruv(', as I have in prcxions papers cntleaNniired lu 

 explain willi re'^aiil to ('anada, and as has Keen sIiunsii liy 

 ot lier ^I'lilii'jisi -; ill I lie ease ul' nt lirr ri"j,ii»iis, thai t he land 

 (if the iiniiherii hemisphere iiiiilerwcnl ill I he later 

 lerl iary periiid a ureal and uradiiai ilfpression and then 

 an eipially u'l-idiial ele\al imi. M\erysiep nf this prnecss 

 wonld liriii'4 iis nioditieatiniis of elimate, and when the 

 dcpressimi had attained its iiia\iiiiniii there prnliahly was 

 as little land in the teinperale re,niiins nf the mirtlieni 

 lieniisjiliere as in the sinithern miw [while that which 

 remained ah(.\(' water was liiuh and ninnntainnnsl.* This 

 windd ,ui\(' a lnw mean temperature and an extension to 

 the sotith of elaeiers, more especially if at the same time 

 a considerahle arctic continent remained aho\-e the waters 

 [as a uatherin^ uronnd|, as seems to he indicated hy tho 

 otl'ccts of extreme niaiiiie glacial action on the ro(d\S 

 under the Itoiilder clay. These condit ions, act ually imli- 

 ealed hy the ])lienomeiia tliemsel\-es,iij»pi'a-r (piite sutlicient 

 to account hir the <'oldness of the seas of the jiei'iod, and 

 tlu! wide diri'iision of the unlf stream caused liy tho 

 suhsideiice of American land, or its csntire diversion into 

 the i'acilic hasin .+ would L,n\(' that assimilation of the 



* The important (luestioii of ditt'erentiiil elevation has been solved in 

 great part since this was written, and woidd mnch strengthen the 

 argnnient. 



t Tiiis is often excluded from cDnsideration, owing to the fact that 

 the nuirint! fauna of tiie gulf of Mexico ditl'ers so much from that of tho 



