Fossih from Magnesian Limestone. — Calvin. 147 
and consists of about six volutions in specimens having a diam- 
eter of one inch. The periphery is sharply angulated and the 
umbilicus wide when compared with other species of the genus. 
Compare R. trochiscum Meek, in U. S. Exploration of the For- 
tieth Parallel, Vol. iv, p. 19. 
Raphistoma multivolvatum, n. sp. Shell moderately large, 
more than an inch and a quarter in diameter; spire depressed; 
whorls five or more in number, increasing gradually in size, each 
about one and a half times as large as the preceding; each whorl 
bears an obtuse angular carina near the suture; suture somewhat 
deeply impressed; upper surface of each whorl concave; outer 
margin marked by a sharp angle from which the convex lower 
surface of the last whorl slopes downward and inward to the 
angle that bounds the umbilicus. 
Raphistoma paucivolvatum. n. sp. This is a small lenticular 
species having from two to two and a half very rapidly expand- 
ing whorls. 
HoLOPEA TURGiDA Hall. There are a number of specimens in- 
distinguishal)le from this species as it is described and figured by 
Hall, Billings and Whitfield. See Paleontology of N. Y., Vol. 
I, p. 12, plate III, figs. 9 and 10; and Lake Champlain Fossils, 
by Whitfield, p. 50, plate ix, figs. 3-7. 
MuRCHisoNiA, Sp. There are a few specimens referable to this 
genus. They are characterized by an elongate spire with many 
sharply angular volutions. 
Orthoceras primigenium Vanuxem. This species is well repre- 
sented by two or three specimens, all showing the characteristics 
by which it maybe readily distinguished. See works of Hall and 
W^hitfield already cited. 
Cyrtoceras luthei, n. sp. Shell. rather small, elliptical in 
transverse section, only moderately curved; length of an aver- 
age specimen from two and a half to three inches, greatest diam- 
eter of body chamber three-fourths of an inch; septa very num- 
erous, ten cham])ers occup3-ing the space of half an inch ; septa 
oblique to the axis, rising highest on the convex side, the obliq- 
uity increasing as the septa approach the chamber of habitation ; 
siphuncle large for the genus, situated close to the inner or con- 
cave margin, tapering more rapidly in proportion to size than the 
shell, and expanding to a trifling extent between the septa. Outer 
chamber long; margin of aperture and surface markings un- 
