127 
UPPER DEVONIAN CRINOIDS FROM THE MACKENZIE RIVER 
VALLEY 
By Frank Springer 
Contents Page 
Introduction 127 
Description of the new species 129 
Illustrations 
Plate XXIV. Illustrations of fossils 181 
INTRODUCTION 
In September, 1921, 1 I gave an account of some crinoids belonging 
to the genus Melocrinus , derived from a locality on Hay river, Great Slave 
Lake region. They are of a type different from that prevailing in the 
Eifel limestone of Europe, where the genus has hitherto been chiefly 
known, but are closely related to species occurring in the upper Mississippi 
valley, in strata formerly classed as Hamilton, but which later investi- 
gations have tended to place higher. The Hay River crinoid-bearing 
strata have been referred by E. M. Kindle 2 to the Upper Devonian, 
and lie above the Simpson shale in which he finds a characteristic Portage 
fauna. 
Mr. Kindle has recently placed in my hands for investigation some 
further crinoidal material, from new localities in the Mackenzie River 
valley to the northwest of the Hay River occurrences. One of these, 
found by the late E. J. Whittaker, is on Trout river, about 150 miles 
distant, and the other by G. S. Hume, about 175 miles farther north, on a 
small confluent of the Mackenzie, called Root river. 
Both of these later finds are assigned by their discoverers to horizons 
above that of the Simpson shale, but their relation to one another has not 
been closely determined. Their crinoidfauna,withasingleexception, belongs 
entirely to the genus Melocrinus , as in the Hay River locality, but the 
species from the three localities are so different, and present such striking 
modifications of one generic type, that they are of much interest both 
from a biological and a stratigraphical aspect. Whereas the Melocrinus 
borealis of Hay river is closely related to the species of Iowa, Missouri, and 
Wisconsin, those of the new localities are not only thoroughly distinct 
from that, but also from each other. And the interesting thing about them, 
from a geological point of view, is that in the characters by which they 
differ so completely from all other known American species, the three new 
species exhibit a tendency to an asymmetrical construction of the calyx 
which is not observed among the abundant species of the Eifel limestone of 
the Middle Devonian, but which developed in certain species belonging 
to the Frasnian (or lower) member of the Upper Devonian in Belgium. 
Not only so, but the single specimen in the new collections which is 
not a Melocrinus , but belongs to Hexacrinus , another very prevalent Middle 
Devonian genus in the Eifel, but very rare in America, is of a type com- 
pletely different from that of the Eifel, but which is also represented in 
the Upper Devonian rocks of Belgium. 
1 Geol. Suit., Call., Bull. 33, pp. 15-18. 
*Geol. Surv., Can., Bull. 29, 1619, p. 4. 
