GASTROPODA. 983 
Lophospira spironema.] 
This elegant species is undoubtedly closely allied to L. owent, 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 
larger and the umbilical fold, which is a well-marked feature in that species, is much 
less developed or quite unrecognizable. L. pulchella, which also we regard as closely 
related, is a very much smaller shell. In L. ampla the apical angle is wider, the 
upper carina scarcely as sharp, the lower carina quite obsolete, and the inner lip 
peculiarly twisted. 
Formation and locality—Upper Trenton, near Nashville, Tennessee, where the seven silicified shells 
upon which the species is founded were collected by Prof. J. M. Safford. This gentleman is not only an 
illustrious geologist, but the kindest and most generous that it has been our good fortune to meet. We 
consider it, therefore, peculiarly appropriate that this shell, perhaps the handsomest ot the fossil gastro- 
pods occurring in the state which he has so long and, honorably served as state geologist, should be con- 
nected with his name. 
LOPHOSPIRA SPIRONEMA, ”. Sp. 
PLATE LXXII, FIGS. 4447. 
Hight 10 to 15 mm.; apical angle 58° 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. pulchella, and we 
doubt very much that abraded examples of the two could be separated. The carinz 
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 striz of growth are stronger. The next species, L. tenuistriata, approaches 
closely but has sublamellose lines of growth, finer spiral lines, less prominent carinz 
and different peripheral band. 
Formation and locality.—Ctenodonta bed of the Black River group, Chatfield and near Cannon Falls, 
Minnesota. 
Collection.—E. O. Ulrich. (5specimens.) 
LoPHOSPIRA TENUISTRIATA, 7. sp. (Ulrich.) 
PLATE LXXII, FIGS. 48—50. 
Hight 10 to 16 mm.; greatest width about 69-100ths of the hight; apical angle 
about 57°. Volutions six or seven, angular, with only moderately developed upper 
and lower carinz; central carina very prominent, thick, rounded, bordered on each 
side by a delicate raised line; basal part of shell somewhat ventricose, gently 
