976 THE PALEONTOLOGY OF MINNESOTA. 



[Lophospira conoldea . 



This species, considering that it is a close ally of L. perangulata and L. elevata, 

 and therefore an undoubted Lophospira, is remarkable for the great elevation of 

 the spire. It reminds decidedly of L. bowdeni Safford sp., but has a larger umbilicus, 

 more angular volutions and a well developed lower carina, a feature that is scarcely 

 distinguishable in that species. In our opinion L. producta has been developed from 

 L. perangulata, while L. boicdeni probably had its origin in L. oweni. 



Formation and locality. Upper Trenton, Nashville, Tennessee. 

 Collection. E. O. Ulrich. 



LOPHOSPIRA CONOIDEA, n. sp. (Ulrich.) 



PLATE LXXII1. PIG. 22. 



Hight about 40 mm.; apical angle 42. Volutions about six, somewhat loosely 

 coiled. Peripheral carina prominent, situated very low for the genus, just above 

 the deep suture, the edge thick and flat rather than round. An angulation about 

 the middle of the under side of the last whorl surrounds a slight depression which 

 farther inward sinks rather suddenly into a deep umbilicus. Upper slope slightly 

 concave in the lower half, convex in the upper. Lines of growth sweeping strongly 

 backward to the peripheral band, consisting without regularity of stronger and 

 weaker striae. 



This species is remarkable for the low position of the peripheral band. In this 

 it has gone a step farther than L. producta, which we believe connects it with L. 

 decursa and through that with L. perangulata. 



Formation and locality. The type specimen was found by Prof. J. M. Safford in the Trenton group 

 at Nashville, Tennessee. 



LOPHOSPIRA PERAOUTA, n. sp. 



PLATE LXXIII. FIGS. 15-17. 



Hight 25 to 40 mm.; apical angle 58. Volutions five or six; peripheral band 

 rather sharp and very prominent; upper surface of volutions gently concave to the 

 suture, without a trace of the carina; lower carina wanting; umbilicus small, 

 aperture rounded below and upon the inner side; surface markings obscure, curving 

 backward strongly. 



In this species the peripheral angle is sharper and more prominent than in any 

 other known to us. The mouth is shorter and rounder upon the inner side and the 

 volutions project over each other in a greater degree than in L. oweni. The shell 

 is much larger, and the peripheral angle more prominent than in L. perangulata. 

 That species diners further in having a lower carina. L. ampla has a wider apical 

 angle, a subsutural carina, and a differently shaped aperture. In L. sumnerensis 



