252 The American Geologist. Anrii, 1901 
Spirifer niacra Hall. 
This is the shell referred to by Dr. Ami and the writer 
as like 5". pemiatus^=S. mucronatus. The best specimens 
were collected by Mr. E. Ardley, and are now in the Red- 
path Museum. The shell differs from the long-hinged 
Marcellus variety of S. pennatus in having a wider ventral 
hinge area and no distinct bilobation of the ventral medial 
fold, characters in harmony with 5". macra. It is closely 
related to 6". pennatus, but more directly with 6^. macra, 
and is considerably removed from 6". cumherlandiae, of the 
Oriskanian. There is no shell in the Helderbergian with 
which it can be compared. 
Spirifer civ. granulosus {Conrad). 
Associated with S. macra, there is a more rotund spe- 
cies, with high, slightly incurved ventral area, angular 
sinus, and prominent dental plates. These are characters 
associated with 6". gramilosus. At present none of the 
specimens of this species are at hand, and no identification 
can be made. However, it undoubtedly belongs to a spe- 
cies in the Middle Devonic. 
CONCLUSION. 
The foregoing evidence shows clearly that two distinct 
faunas are represented on Saint Helen's island, — one, the Hel- 
derbergian, older than the agglomerate, and another, from a 
block in the agglomerate, of Middle Devonic age. 
The Helderbergian fauna is apparently related with that 
of New York, and belongs to the facies occurring on the west- 
em side of the Appalachian folds. The writer has collected 
this fauna at Dalhousie, New Brunswick, and from the Gaspe 
region, Quebec, and both are of another facies and belong to 
another basin. 
The presence of RhipidouicUa recalling R. iiiusculosa; Spiri- 
fer concinnus ; an early variety of 5. murchisoni; Spirifer n. sp., 
connecting phylogenetically 5. concinnus and S. arcnosus; 
Camarotocchid pleio pleura; Gypidula pseudogaleata, and 
Renssclacria acquiradiata, show that the Saint Helen's Island 
Helderbergian is not as old as the New Scotland zone. Spiri- 
fer concinnus, and especially G. pseudogaleata and R. acquira- 
diata, arc characteristic Becraft zonal species. However, the 
