978 THE PALEONTOLOGY OF MINNESOTA. 



[Lophosplra suiunerensis. 



LOPHOSPIRA SUMNERENSIS S 

 PLATE LXXIII, FIGS. 18-20. 



Mnrckisonia sumnerensis SAFFORD, 1869, Geol. of Tenn., pi. o., flgs. 1, a-/. (Not defined.) 



flight 18 to 42 mm., usually 25 to 30 mm.; apical angle 60 to 73, usually 64 

 or 65. Volutions four or five, the last very large, the upper surface deeply concave, 

 the sutural edge slightly thickened but never carinate, the peripheral angle not 

 very prominent; beneath it the sides are at first nearly vertical then broadly convex 

 to the umbilicus which is entirely closed by the curved inner lip; the latter is thick 

 and expanded; aperture unusually high, narrowly rounded below, more broadly 

 convex upon the columellar side. Surface markings somewhat irregular, moderately 

 distinct though never very sharp, curving strongly backward from both above and 

 below to the peripheral band. 



The unusual hight of the last volution and the absence of upper and lower 

 carinae are the principal peculiarities of this species. The species is probably not 

 far removed from L. elevata and L. peracuta, but all three forms seem to us to be 

 easily recognized. In the last the peripheral angle is much more prominent, the 

 last volution not nearly so high, and the upper surface much less concave. In the 

 second there is a well-marked broad concave band beneath the peripheral angle, 

 while the volutions are more exsert, the upper ones exposing more of their sides. 

 In L. multigruma (Miller) the apical angle is greater, the volutions not so high, the 

 upper surface nearly flat and the peripheral band more prominent. 



Formation arid locality. Upper beds of the Trenton group, Nashville, Tennessee, and Mercer and 

 Boyle counties in Kentucky. A single cast of the interior from the Fusispira bed at Wykoff, Minnesota, 

 probably belongs to this species. 



Collection. E. O. Ulrich. 



LOPHOSPIRA BKJIITIOIVPMA- Mrtter. 



PLATE LXXII, FIGS. 36-39. 



', " 



Murdwsonw. multigruma MILLER, 1878, Jour. Cin. Soc. Nat. Hist., vol. i, p. 104. 



~ 



Hight generally from 25 to 35 mm.; greatest width equalling from 75 to 

 80-100ths of the hight; apical angle 75 to 80. Volutions five, uniangular; base 

 produced, rounded; umbilicus closed; columellar lip thick and slightly twisted below. 

 Surface markings curved strongly backward to the peripheral band, coarse and 

 rather irregular on the base of the last whorl, much less distinct on the nearly flat 

 upper slope. When perfect the lines of growth are somewhat lamellose. 



This species is closely related to L. sumnerensis Safford, but is distinguished by 

 a wider apical angle, more prominent peripheral band, plane instead of concave 

 upper slopes, and more twisted and thicker colurnellar lip. Dr. Miller says further 



