C6C XBW YORK STATE MUSDUM 



l»assaj;i' out into a broad and dt'i'iKT j;ulf extt-uding to the iiortL- 

 i*ast continuously or disciuitinuously to boyond the coast of :]ie 

 niaritinu' provinces. In this dcejM-ned head of tlie j,Milf (he 

 Ilrhh'rbci-jrian fauna, t ravelin*,^ soutliward from a lon^ sojourn 

 in inchoalivc rcHulition in Hn' rcj^^ion of the (Inlf of St Lawrence, 

 achlin^' vitality and prolixity on its way (as shown at Dalliou^ie 

 N. It.). s('(pu'ster('d itself in dctjuning water and was fruitfully 

 multiplied to its climax. T\w llelderberfr fauna as a whole was 

 thus an invader from the northeast. The narrow bar whicli 

 sei>arated its first assession from the Appalachian «;ulf was in 

 a state of dej^M-adation so extensive that, at the earliest period 

 <»f its ]u-esence, t ransjiression over this barrier was rea<lily 

 etf(»cted, but not a transj^n-ession which extended far, as tlie 

 liarrier renmined an obstacle to free migration. 



The Tlelderbergian, liowover, did not gain possession (►f an 

 extensive area in New York during its earliest manifestations, 

 its species commingled in some measure with the frail Siluric 

 congeries on the ground of central and western New York 

 Avhich had endeavored to reinstate itself with the gradual fresh- 

 ening of the Salina sea, but in later stages of its existence the 

 reiutegration of the barrier shut out from the area of the Appal- 

 achian gulf all evidence of its tinal ]>iiases (liecraft, Kingston 

 i^Voyt Ewen) beds). The area of the IFelderberg in New York 

 was its fruitful center of dispersion, and thence its travels were 

 southward along the barrier, probably around its southeiu 

 t<'rmination, and from there into the Appalachian gulf in the 

 rrgioii of western Tennessee, Illinois and Indian Territory. 



Oriskany fauna 

 From the same direction and along the same thorouglifare 

 <ame the Oriskany, its center of variation and dispersion un- 

 (juestiouably being in the region of Uaspd bay, where now its 

 species are dispersed through 800 feet of limestone. Leaviu"" 

 behind it s])ecies wliicji m.-iy have survived in the Gasp(^ 

 sandstones to a later period of Devonic time, it followed in the 

 train of the Ilehh'rberg fauna, manifesting itself most jwrfectly 

 ill tin- silirinus liim'sloiies of Columbia and Ulster counties. 



