DEVONIAN AND MISSISSIPPIAN FAUNAS 267 
Illinois and Indiana, as well as in a basal Kinderhook shale in Missouri. 
At the base of the formation a thin band occurs which is frequently 
crowded with the teeth of Péyctodus calceolus, the same species which 
is present in the State Quarry beds and one which also has a wide 
dis‘ribution at the very base of the Kinderhook formations. 
Following the Devonian of the Interior Continental Province to 
the northwest, it is next well exposed in Manitoba, and has been well 
described by Tyrrell.1| Approximately 510 feet of strata are recognized, 
the lower 100 feet not having afforded any fauna. The beds referred 
to the Middle Devonian (Winnipegosan) are characterized by the 
presence of Gypidula comis throughout, and by Séringocephalus 
burtoni in the upper portion. The last of these species does not occur 
in Iowa, but Gypidula comis is an abundant and characteristic member 
of the fauna of the upper beds of the Wapsipinicon stage, where it is 
associated with Rhynchonella intermedia Barris (Hy pothyris cuboides). 
In western Europe Stringocephalus burtoni is the index fossil of the 
Stringocephalus limestone at the summit of the Middle Devonian, and 
occurs immediately beneath the Cuboides zone. The Devonian beds 
superjacent to the Stringocephalus beds in Manitoba have been 
referred to the Upper Devonian by the Canadian geologists, a cor- 
relation which is doubtless correct, since the faunal succession is 
similar to that in Europe, where Séringocephalus burtonit marks a 
distinct horizon at the summit of the Middle Devonian. 
The Devonian fauna of the Mackenzie basin has been described 
by Whiteaves? and has been correlated with the Cuboides zone of 
Europe and New York, a correlation which seems to be based on 
substantial evidence. Seventy-six forms are specifically identified, 
twenty-nine of which are either present or are represented by close 
relatives in the European faunas of similar age, while twenty-two are 
identified with American Hamilton species, ten with Iowan and seven 
with Chemung forms. In the Mackenzie basin the Stringocephalus 
zone has not been so clearly recognized as in Manitoba, although it is 
indicated in at least one locality. The entire Devonian section in the 
Mackenzie Basin consists of 2,800 feet of strata, but a considerable 
part of the lower portion may be of greater age, and the entire fauna is 
t Geol. Surv. Canada, Ann. Rep., V, (N. S.), Pt. I, pp. 204-9 E. 
2 Cont. Can. Pal., I, 197-253, pls. 27-32. 
