OF DENISON UNIVERSITY. 87 



but are flat or even concave between the carinae, being evenly round- 

 ed below to the apparently small umbilicus. Aperture unseen, appa- 

 rently sub-circular. Height i6mm; width 14 mm; height of first 

 volution 9 mm, distance between the upper and median carince, 3 mm. 

 The condition of our specimens makes it difficult to distinguish them 

 from the Hamilton species quoted. Frequent in the upper parts of 

 the freestone. 



Since the above was written some very perfect specimens have 

 been secured from Moot's run (see Plate XH, Fig. 39.) The species 

 therefore mav be regarded as ranging upwards into the freestone and 

 not properly belonging there. From Cyclonema lyrata this form dif- 

 fers in lacking the revolving striae on the lower surface of the whorls. 

 Casts of the interior found in situ, show Fig. 15, of Plate I, to be such 

 a condition of the present species. 



Jfurrhisojiia quadricincfa, ^Vin. ? 

 (Plate n. Fig. 28.) 



The numerous specimens are all casts in poor preservation, hence 

 the reference is of the nature of a suggestion simply based on a gen- 

 eral resemblance. Prof. Wmchell informs me that the species has 

 hitherto been only identified in Iowa. 



Maticopsis'^ sp n. 



(Plate Xn, Fig. 37.) 



Lack of time prevents a study of this interesting species. It is 

 not certain that this is not a species of Strophostylus resembling S. va- 

 rians, but is probably nearer to Naticopsis comperta. 



Enornphahts latus, l^- ? 



(Cf. E obtusus, H.) 



(Plate XH, Fig. 26.) 



Our only specimen is very imperfect, making it impossible to as- 

 certain with certainty its characteristics. The upper surface of the 



