1-r.pbo.plr. .pinion 



Tin- elegant secies is undoubtedly closely allied t< /.. /. but the persistence 

 and sharpness of its upper and lower keels serve readily in distinguishing it. The 

 lower extremity of the mouth also is more rounded, while the umbilicus is a trifle 



rand the umbilical fold, which is a well-marked leature in that species, is much 

 leas developed or quite unrecognizable. L. fmlcliella. which also we regard as closely 

 related, is a very much smaller shell. In /.. <nnf>la the apical angle is wider, the 

 upper ram ely as sharp, the lower carina unite obsolete, and the inner lip 



peculiarly twisted. 



and totality. Upper Trenton, near NMhvllle, Tennessee, where the seven si I let fled shells 

 up-.n which tli.- specie- I were collected by Prof. J. M. Safford. This gentleman Is not only an 



llluHlrl.i;- kindest anil r .us that It has been our good fortune to meet. We 



prlate that this shell, perhaps the handsomest ot the fossil gastro- 



pod* - i!- whlrh In- has no long and h.-n-irably served as state geologist, should be con- 



I with his naiii--. 



IX)PHO8PIRA 8PIRONKMA, M. tp. 



.3.44-17. 



Might 10 to 15 mm.; apical angle 53 to 62. Volutions five or six, angular; 

 periphery trilineate, very prominent, the surface on each side decidedly concave; 

 lower carina sharp and strong; upper carina thin but distinct, close to the suture. 

 Lines of growth very fine, not sharp, strongest near the suture, curving strongly 

 backward from both sides to the peripheral angle; entire surface with very delicate 

 revolving lines. 



This shell, in its general expression, is exceedingly like L. pulchclla, and we 

 doubt very much that abraded examples of the two could be separated. The eari mi- 

 may be somewhat sharper and the apical angle greater, but the only reliable and 

 important difference lies in the surface markings, that species having no spiral lines, 

 while its striae of growth are stronger. The next species, L. Unuistriata, approaches 

 closely but has sublamellose lines of growth, finer spiral lines, less prominent carinae 

 and different peripheral band. 



Ibrmo/ion axd locality. ,U bed of th<- lilack Uiv.-r k:r..iip, Chatfleld and near Cannon Falls, 



Minnesota. 



Collection. K h. (5sp-cimens.) 



I."I'HOS1>IRA TKM'I.STRIATA, M. p. (I'lfull.) 



i i \ : v I \\ll I 108. 4S-. 



Might 10 to 16 mm.; greatest width about 6'.)-l<K)ths of the hight; apical angle 

 about *i7 . \olutions six or seven, angular, with only moderately developed upper 

 and lower carina); central carina very prominent, thick, rounded, bordered on each 

 side by a delicate raised line; basal part of shell somewhat veutricose, gently 



