02 KANSAS UNIVERSITY QUARTERLY. 



from ienuistriata, though on account of some of its similarities I 

 leave it here for the present. 



Pseudomonotis (?) robusta sp. (?) var. (?) nov. 



This shell difters from the preceding in being much more convex 

 and arcuate, in having a longer hinge, higher umbo, beak very; 

 much more compressed and scarcely distinct from the umbo, not 

 projecting very sensibly above the hinge. The striae are more 

 regular and much fainter, and either very indistinct or absent on at 

 least the upper third of the shell. Both concentric wrinkles and; 

 lamellae of growth are distinct. Measurements: length 48 mm., 

 convexity 18 mm., height 42 mm., length of hinge about 28 mm. 



In all the specimens we have of this and the preceding species, 

 or variety, the two are easily separated, even the young specimens,- 

 and, so far as I am aware it is confined to the lower half or two- 

 thirds of the Upper Coal Measures. Some of the young individuals 

 are more gibbous than the type. 



Turner, Wyandotte county, Kansas. Also a specimen collected 

 by the writer at Nebraska City, Nebraska, which is probably of 

 this form. 



Pseudomonotis ha-wni equistriata var. (?) sp., (?) nov. 



Shell of medium size, ovate in outline, moderately to quite 

 gibbous, a little oblique with respect to the hinge, beak moderately] 

 prominent, extending to or a little bej'ond the hinge which is about i 

 half the length of the shell and somewhat arcuate. Umbo quite 

 gibbous. Posterior ear very slightly developed, merging into and 

 forming a slight sinus in the posterior margin; ventral, antero- and 

 postero-ventral margins regularly rounded, anterior margin sinuate 

 in the upper portion on account of the anterior ear which is small 

 and round. The surface is marked by fine, somewhat regular, 

 rather wavy striae, which increase by interpolation, each fourth to 

 tenth being usually a little larger than the remainder, though not 

 very conspicuously so. Small lamellae of growth sometimes dis- 

 tinguishable. Some of the striae extended nearly to the beak. The 

 right valve is flat, or a little concave; otherwise unknown. Meas- 

 urement, two specimens: Height 31 mm., 34 mm., length 24 mm., 

 26 mm., convexity 7 mm., 13 mm., length of hinge 12 mm., 16 mm. 

 These two specimens represent the extremes of convexit}'. 



Upper Coal Measures; Turner, W3'andotte county, Kansas. 



In general outline this shell seems to be nearly the same as those 

 from the Kansas Permian. However, it differs from this as it 



