250 NEW YOEK STATE MUSEUM 



Summary. On earlier pages we have indicated the relations of these 

 Gaspe faunas to each other and to those of other regions. These may be 

 briefly restated : 



The St Alban beds present a congeries of 51 species of which fully 

 one half occurs in the typical Helderbergian faunas (Coeymans and New 

 Scotland) to the southwest. This very large community of species is evi- 

 dence of an open and free passage between the Gaspe basin and the New 

 York embayment of the Mississippian sea (Appalachian gulf). On a later 

 occasion we shall have means of pointing out in detail a very like commu- 

 nity of species in the Dalhousie beds of New Brunswick and the Helder- 

 berg of New York, but singularly, in the two cases, this agreement is based 

 on quite distinctive associations of species. There is not much in common 

 between the St Alban and the Dalhousie faunas, but between each of these 

 and the Helderberg fauna there is harmony in certain faunal associations 

 suggesting that the open channel of this date southwestward included the 

 Dalhousie region also ; that intimate commingling of the peculiar Dal- 

 housie and St Alban associations was prevented by a barrier of some kind 

 and, further, that dispersion was from the breeding ground of Gaspe, 

 southwestward, to where the several associations combined into one. 



The more profuse fauna of the Grande Greve limestones, rising to 

 about 150 recorded species, has a less proportion of community with the 

 Helderbergian but still a substantial number of species (21 identities and 

 14 close affines). With the Oriskany there is a larger community of species 

 (39 identities and 13 affines) and so commanding is this percentage and the 

 composition of the congeries itself, consisting as it does of the most typical 

 species of the Oriskany, that it compels this inference : The development 

 of this Oriskany fauna was synchronous with the prevalence of the Helder- 

 bergian fauna in this region and the differentiation of the two faunal 

 elements which we commonly recognize in the Appalachian regions as Hel- 

 derberg and Oriskany, was subsequent in date to the development of the 

 combined faunas together in Gaspe. Thus again we have evidence that the 



