4 
MUSEUM BULLETIN NO. 20. 
than any of the other species and the fauna in the limestone 
immediately above the eurypterid beds contains a number of 
brachiopods of which two genera are in common with the fauna 
of the Eramosa beds. The Kokomo contains Whitfieldella erecta 
Foerste and Anoplotheca congregate, Kindle; the Eramosa, W. 
nitida Hall, and Anoplotheca ? sp. 
Leaving out of account the eurypterids, the Eramosa 
fauna is related as follows: Orthis near tenuidens suggests 
Clinton affinities; Whitfieldella nitida and Conularia niagarensis 
are Rochester species ; Lichenalia concentrica and Spirifer 
radiatus are characteristic of the Rochester and lower Lockport; 
and Camarotoechia whitei is a true Lockport species: Monomorella 
orbicularis , with which I have compared the Eramosa species, is 
typically Guelph. 
Summing up, in the Eramosa shale beds at the top of the 
Lockport, there is a recurrence of a part of the fauna character- 
istic of the Rochester shale, with even a suggestion of a Clinton 
type, these hold-overs being mingled with more typical Lockport 
species and one forerunner of the characteristic Guelph fauna. 
Thus, we have very good palaeontological evidence of the con- 
formable relations of the Niagara and Guelph formations. The 
coral reef, occurring in the Eramosa beds, as already described 
above, contains additional evidence in its mingled Lockport 
and Guelph species that the eurypterid fauna lived at a period 
of transition between Lockport and Guelph time. The pre- 
ponderance of the earlier elements, however, makes it seem 
advisable to class the Eramosa beds, as has formerly been done, 
with the Lockport rather than the Guelph. 
Discussion has formerly arisen as to the habitat of the 
eurypterids and examples are rare where eurypterids and 
well established marine species occur in the same beds. That 
in this case the eurypterids lived in an entirely marine 
habitat is shown by the associated fauna. 
