INVERTEBRATE PALEONTOLOGY. . 5'J9 



man! that, if he would send me brief descriptions with the names ol his 

 new species, I would adopt them. He then informed me that he had called 

 this one L. Meekiana in his manuscript, which I believe he never published. 

 Locality and position. — Pinots' Creek, upper part of the White River 

 group. 



I . i in n eb a S li ii in a rdi, Meek. 

 Plate 45, 6gs. C, a,b. 



Shell rhombic-subovate ; spire less than half the entire length, very 

 acute at the apex; volutions five and a half, convex, last one not ventricose, 

 rather oblique; suture moderately well defined; surface marked by distinct 

 lines of growth, and sometimes having, on the upper part of the body-whorl, 

 a few broad, obscure, vertical or oblique folds; aperture ovate, rounded 

 below, and angular above. 



Length, 0.81 inch; breadth, 0.51 inch; length of aperture, 0.49 inch ; 

 breadth of same, 0.26 inch ; apical angle nearly regular, divergence 54°. 



It is possible that this may not be distinct from the last, though I have 

 not yet seen intermediate gradations between these forms. The shell here 

 under consideration differs from the preceding in being smaller and propor- 

 tionally more slender; while its body-whorl is much less ventricose and 

 more oblique. It also differs in sometimes showing a tendency to form 

 obscure folds on the upper part of the last volution. It is named in honor of 

 the late Dr. B. F. Shumard, formerly State geologist of Texas. 



Locality and position. — Same as last. 



Genus PLANORBIS, Miiller (see page 534). 

 Plan or bis Leidyi, M. & H 



Plate 45, li{;s. 3, a, b, c, rf. 



Planoibis Leidyi, Meek and Hayden (18(50), Proceed. Acad. Nat. Sci. Philad., IX, 175.— Meek (1804), 

 Smithsonian Check-List N. Am. Tertiary Fossils, 13. 



Shell small, subdiscoidal ; spire flat, or a little concave; volutions 

 scarcely three, increasing rather rapidly in size, not embracing on the upper 

 side; inner ones almost entirely hidden by the last turn below, all convex 

 above, rather narrowly rounded on the upper outer side, and ventricose and 

 rounded below ; suture well defined ; umbilicus small, or less than half the 

 breadth of the outer whorl, deep, ar.d scarcely permitting the inner volutions 

 to be counted. Surface marked by fine, delicate lines of growth; aperture 



