issg.] Geology and Paleontology. y 1 1 
Hall and Whitfield), as will be readily seen by a comparison of the 
descriptions of the two genera. This genus is named in honor of Mr. 
W. J. McGee, of the United States Geological Survey. 
Macgeea soUtaria, H. and W. — PachyphyUum solitarium H. and 
W., Twenty-third Annual Report of Board of Regents on New York 
State Cabinet, page 232. The specimens referred to this species are 
often quite available, and show several important features not men- 
tioned in the original description. The denticulate character of the 
rays and costas is most usually observed only in well-preserved speci- 
A critical examination of nearly two hundred specimens of this 
species reveals that the bottom of the calyx in well-preserved 
specimens is never occupied by a ' 
but, on the contrary, by a depressio 
of the above-mentioned Report. This feature is the result of 
weathering. 
Macgeea parva n. sp. — Coral single, very small, from five to 
six mm. in length, and from five to six mm. in greatest diameter ; 
sometimes scarcely, and at other times sharply curved ; subconical, 
but at times very strongly produced on the convex side of the cell, 
thus giving the calyx a distinct ovate marginal outline. 
Calyx contracted at the top, about as wide as deep ; outer wall of 
moderate thickness, bottom of the cup large. In the longitudinal section 
of a single specimen, the bottom was seen to be occupied by a very 
slight elevation ; but whether or not this is a constant feature can be 
ascertained only by securing a larger number of specimens for ex- 
amination than has as yet been obtained. 
Costse continuous with the lamellae over the margin of the cup 
and for some distance downward ; lower down covered by a 
smooth, perfect epithecal coat, sometimes annulated by fine striae, 
of growth ; lamellae and costae alternately large and small, some- 
times slightly denticulate on the edge (the occasional absence of 
this feature is apparently due to attrition) ; from thirty-five to forty-two 
in number. 
This species is closely related to M. solitaria of the Rockford 
shales, but differs from that species in its very small size, always con- 
tinuous, perfect, and much smoother epitheca ; the relatively thicker 
outer wall, as well as the strong constriction of the upper portion of 
the cell. 
Position and locality : Blue shales below the Devonian limestone. 
Independence, Iowa. 
