1044 THE PALEONTOLOGY OF MINNESOTA. 
[Trochonematide. 
these Mr. Ulrich proposes to establish and add two new genera which he regards as 
related to Cyclonema. The first of these he names Dyrrta, in memory of the late 
C. B. Dyer, a former well-known collector at Cincinnati; the other Bucanospira, in 
allusion to the trumpet-like expansion of the aperture. Both of these genera may 
prove to have closer relations to Platyceras than we now believe.* 
Fic. 8.—T wo views of a large specimen of Dyeria costata James sp. from the upper half of the Lor- 
raine group at Cincinnati, Ohio. Collection of E. O. Ulrich. 
Dyeria is founded on a Cincinnati fossil originally described by Mr. U. P. James, as Cyrtolites costatus,7 
but since 1875 known to collectors as Bucania costata. Heretofore it was supposed that its whorls were 
co‘led in the same plane, but, as may be seen from the accompanying illustrations of a full-grown speci- 
men, this is not the case. Still, the coiling of the whorls may be more nearly in one plane than in the 
figured specimen—indeed, in one case before us the last whorl turns upward instead of downward 
According to our opinion Dyeria costata, as it should now be called, is in no wise related to any member of 
the Bellerophontacea, but on the contrary is not far removed from Cyclonema. The surface sculpture is of 
a type pertaining quite generally to that genus, even to the matter of the transverse wrinkles or undula- 
tions on the last whorl of old examples. It is true the margin of the lip and, therefore, the lines of 
growth, take a more undulating course in circling the whorls than in any Cyclonema known to us, but 
when a sinus does occur in the lip of a Cyclonema it is in a corresponding region or regions. However, 
Dyeria differs widely from that genus in the depres-ed—almost involute—form of its shell, in having a 
considerable part of the last whorl vagrant and nearly straight, and in the simple unthickened character 
of the inner lip. It remains to beseen whether the vagrant character of the last whorl is essential or 
not. If it is not then the genus may justly include forms like Lindstrém’s Huomphalus tuba. 
a“ c F b 
Fie. 9.— Bucanospira expansa, n. gen. et sp. (Ulrich), Niagara group, Wayne county, Tennessee. a 
and b, slightly restored views, XZ, of a silicified shell, showing the expanded aperture, remains of preced- 
ing expansions (at a and 0 on fig. a), and surface markings; c, under side of the interior cast of a larger 
specimen with indications of numerous successive apertural expansions. The umbilicus is relatively 
larger and the spire lower in this specimen than in the first. Collection of E. O. Ulrich. 
Bucanospira is based on an undescribed Upper Silurian shell from western Tennessee, for which we 
*The Platyceride are greatly in need of revision. While the majority are doubtless referable to the capulids, many 
others belong near Cyclonema and Dyeria among thedrochonematide, Or, if that arrangement is not acceptable, then the latter 
family will have to be restricted to Trochonema and Cyclonema, and Slrophostylus (which we extend so that it includes shells 
commonly arranged under Cyclonema), together with Holopea, Dyeria and Bucanospira removed to the Calyptrw@ide; or a new 
intermediate family must be instituted for their reception. 
+ Amer. Jour, Sel. and Arts, 3d ser., vol. iii, p. 26, 1872; see also Meek, 1873, Pal. Ohio, vol, i, p. 150, pl. XIII, figs. la,te. 
