132 
This species, from a different locality and probably a different horizon 
from the preceding, is readily distinguished from them and from all others 
known by its marked ovoid contour, and extremely small column facet, 
which indicates a considerably different type of column from that of the 
genus as generally found. The tendency is usually to a broad base. None 
of the Belgian species is at all similar to this except in asymmetry. 
There are three well-defined specimens in which the characters are thor- 
oughly constant. 
Horizon and Locality. From beds at least 300 feet above the Simpson 
shale, and thought to be somewhat higher than the M. borealis horizon 
of Hay river, Upper Devonian. Trout river, about 15 miles above its 
confluence with the Mackenzie, North West Territories, Canada. Collector, 
E. J. Whittaker. There is some reason to believe that the horizon of this 
species may be close to, if not identical with, the upper horizon of the Hay 
River crinoids, from which the fragmentary M. canadensis was derived. 
Imperfect specimens among the present material strongly suggest the 
form of that species. The specific name is given in recognition of the 
discoverer, Mr. E. J. Whittaker, whose careful observations have greatly 
facilitated the study of the fine material collected by him at both the Hay 
River and the Trout River localities. 
Hexacrinus humei n. sp. 
Plate XXIV, figures 18, 19 
A very small species, founded upon a single specimen from which the 
base is partly removed by fracture. The calyx is 10 mm. high above tho 
base, 8 to 10 mm. wide at the level of the arm bases, and 5 mm. wide at 
the edge of the fractured base. From analogy of related species, the base 
presumably was low, with a projecting rim. Plates of the cup are smooth, 
and not convex. Tegmen, as usual in the genus, consisting mainly of 
large orals and modified ambulacrals, which are all more or less acuminate. 
Anal opening strongly excentric, and directed laterally. 
This species, one of the smallest yet described, is associated with 
Melocrinus kindlei and M. mackenzie, and like them bears a remarkable 
resemblance to the Upper Devonian forms of Belgium. Its habitus is 
widely different from that of the well-known species from the Eifel lime- 
stone, but in the characters by which it differs most from them it approaches 
Hexacrinus verrucosus and H. minor of Dewalque in Fraipont 1 from the 
Frasnian at Senzielle. The latter is similarly minute, but differs in the 
strong gibbosity of the cup plates. The former is much larger and more 
robust. Our species differs from both in the lateral direction of the anal 
opening. 
Horizon and Locality. Upper Devonian, Leiorhynchus zone. Root 
river, North West Territories, Canada. Collector, G. S. Hume, in whose 
honour I have named the species, which is of especial interest, not only 
for the emphatic way in which it confirms the correlation of this fauna, 
but also for the extremely 7 rare occurrence of the genus in America, 
i Annates de la See, geol. de Belg. t. XI, 1884, pp. 108-110, FI. 1, figa, 3, 4. 
