GASTR' 



ampU ) 



The tir>t convexity beneath the peripheral band represents the lower 

 ia of /.. perntHjultit'i an-l other species, and in young shells it is sharp enough to 



be calle'i a carina. but as growth proceeds it becomes more and more obtuse. 



Aperture straight at the inner margin, and somewhat narrowly produced at the 

 r aii^le. Suif.Kf markings rarely preserved; win-never preserved they consist 



of rather distant. delicate. -iiblamellose stria, with very fine lines between them, all 



curving backward strongly to the peripheral hand. 



This is a much larger shell than L. peran<julata t yet has about the same number 



of \olut i. .11 v The apical angle also is greater, while both the under and upper sides 



of the volutions are obviously ditlerentin several respects. L. cent raits never has 



so strong a subsutural swelling, its peripheral band is less prominent, and the under 



side of the whorls more ventricose. 



Formation and locality. Ears in the Stones River group at High Bridge, Kentucky; not uncommon 



.ruup, especially in the Ctenodonta bed, at St. Paul, Minneapolis, Cannon Kail-, 



Chat Held and Fountain, In Minnesota; also In Mercer county. Kentucky. Asyet It Is not known to occur 



in thr Trvnt<ui |>rup.-r. buta smaller yet otherwise Indistinguishable form reappears In the Utlca group at 



tmatl, Ohio, and localities In that vicinity. About 60 specimens. 



CMtecfton*. Geological and Natural History Surrey of Minnesota; E. O. Dlrlch; W. H. Scofleld. 

 m Remitter, No*. 7521, 6865. 



LOPHOSPIRA AMI-LA, n. sp. (I'lrirh.) 



PLATE LXXI1I. PIGS. 



. of Loraine group specimens, 20 to 32 mm., of Richmond group specimens, 

 50 mm.; apical angle 70 to SO . Volutions about six, the last equalling about 

 two-thirds of the total hight. Upper carina thick, near the suture, present on all 

 volutions; lower carina nearly obsolete, represented by a broad swelling or low 

 riilgp, above which to the prominent peripheral band the surface is more or less 

 concave. Inner lip very thick, almost or entirely covering the minute umbilicus, 

 very broad and turned obliquely downward anl forward in the basal half. Surface 

 markings very strongly curved, unequal, on the whole not sharply defined. 



~ely related to L. otceni, yet ea-ily 'li-tiiitfiiished by the greatly thickened, 

 broad ami obliquely extended inner lip. The apical angle also is greater, and the 

 lines of growth are more curved, especially at the base, while the upper carina does 

 not fade away on the last volutions as in that species. The presence of this carina 

 listinguishes it from the associated and otherwise similar /,. mulliyniHia Miller. 

 /,-. nif'liuli.i. which is usually much smaller, with the same number of volutions, a 

 smaller apical angle and more distinct umbilicus, also has no such sutural carina. 



Formation and iooaJtfy. Cincinnati | up. Cincinnati, uhi... an<l Covlngt-.n, K-n- 



t rk > "! group, Klchnn.ini. Indiana, and at sev.-ral localiti. and I.n .ritles, 



Kentucky. 



CoUtetio* .-K. O. flrirh. ( 17 speclmeiM.) 



