Q iffl BO1 



'.111 



-pfcimen figured seems to be complete. If thi-> i- the case, then we have 



another feature in which C. bflliil-i 'litler- from both of the species with which we 

 inpare.l it. Namely, ;i slit extending only ;il..ut a fourth, instead of half 

 around the circumference of the last turn. 



format** and locality. -Lower half of the Loralne group, Coving"", K. ntm-ky. 

 CMbctfM.-K. O. nn.-h. 



NRADBLLA BLBOANS Miller. 



i'i MI i AMI. i tat i;-i. 



CgrtoUla dyeri (pa l"73. Pil. Ohio, vol. I, p. M9, plat.' MM, tigs. 24, 2e. 



ottw tJrjuiw, MILLER, 1074, Cincinnati Quart. Jour Sol., vol. i, p. 310. 



This species is closely related to and about of the same size as C. dyeri Hall, 

 I. ut we cannot say that we ever found it difficult to distinguish. In the first place 

 the traii>\er.-e himrll.r are less crowded sometimes they are more than twice as 

 far apart as in that species; next the undulations or loops of each are not so deep 

 and fewer, there being only five or six to a side as against ten in C. dijtri; then it is 

 only in rare instances that even the most obscure appearance of revolving ridges is 

 observable: finally, the whorls are a trifle higher, while the slit-band bears distinct 

 and closely arranged lunulu 1 . The last is probably to be regarded as the most 

 important of the ditlerences mentioned. The C. triangularis of the Stones RIMT 

 group, though of a similar type, is readily distinguished by its larger size, rougher 

 MI i face, oftener and more deeply undulated lamella;, and angular umbilical edges. 

 C. ymntlis is perhaps nearer than any other, but it grows so much larger that there 

 is little danger of confusion between them. For comparisons with C. bellula see 

 that description. 



Formation md IntnHly As yet ilii* ptvtty shell IK known only from the shaly limestones of the 

 Loralne group, at Cincinnati, Ohio and lo<-;iim> - in the Immediate vicinity of that city. 



Cb(ieet*m.-X. O. Dlrich. 



VKAPKM.A IMBKICATA Meek and ll'orthen. 



I'l.ATK I. XVII. FIO. II. 



Cyrtoiilt* imbncatiu MEEK and WOIUIIKN, 1W, Geol. Surv. 111., vol. Ill, p. :u<. pi. iv, tig. u. 



A good figure of this species has not yet been published, and as it is an 

 interesting form and one that may l>e expected to occur in- Minnesota, we have 

 li-cided to illustrate a specimen that a careful comparison with the original type 

 proves to belong to the same species. This specimen is from the same locals 

 the type and differs from it only in being smaller. The greatest diameter of the 

 type is about *_'- mm.: in our specimen 15.5 mm. 



