258 



Rather striking, also, is the restriction of the faunules in 

 the several beds and the appearance of different species in 

 these beds. This tendency, the limitation of and difference 

 in the faunules in successive beds, is believed to be due to 

 varying biotic conditions. 



Several species are common to the lower and upper members 

 of the Windsor, among them Productus cf . arseneaui, Produc- 

 tus laevicosius, Pugnax dawsonianus, and Dielasma sacculus. 



One species only has been found common to the Point 

 Edward formation and the Windsor series, the ostracod 

 here called Beyrichiopsis granulata var, which is so strikingly 

 distinct as to be easily recognized. It occurs in several 

 beds of the Windsor, ranging from the basal bed of the 

 lower member into the middle of the middle member. 



In the whole Windsor series of this section, there is only 

 one bed and one locality, so far observed, where fossils 

 are abundant. This is in the upper member. Usually 

 they are scarce, and not infrequently they are to be 

 obtained only after a long and patient search. 



Following is a list of the species obtained in the lower 

 member at the Point Edward Post Office locality. The 

 numbers at the top of the columns are the ones used to 

 designate the beds in the detailed section already given. 



Serpulites annulatus Dawson 



0] .J 



I 



li 



I 

 X 



6 



7 



9 



14 



15 



Spirorbis sp 











X 





Productus cf. arseneaui Beede. . . . 







X 



X 





X 



Productus auriculispinus Beede... . 

 Productus dawsoni acadicus Beede. 



X 













X 











Productus laevicostus White 



X 









Productus tenuicostiformis Beede.. 









X 



X 



X 



Productus sp.. 





X 

 X 

 X 









Pugnax dawsonianus Davidson. ... 

 'Dielasma sacculus Martin' 





















X 



Aviculopecten sp 



X 











Aviculopecten cf. debertianus Daw- 

 son 









X 







Leptodesma sp 







X 



X 







Leiopteria dawsoni Beede.. 







X 







Gastropod gen. et sp. (a) 









X 



X 



X 



Gastropod gen. et sp. (&)... 







X 

 X 

 X 

 X 





Orthoceras sp. . . 







X 









Endolobus avonensis Dawson 













Ostracods 



X 

 X 





X 





X 



X 



Beyrichiopsis granulata J. and K. 

 var. . . 



















