I)KEDE.| Carboniferous Invertebrates. 133 



Pseudomonotis kansasensis, nom. nov. Plate XIV, figs. 1-ld. 



Pseudomonotis tenuistriata sp.?var.? Beede, Kans. Univ. Quart, vin, 

 p. 81, pi. xvm, ff. 1-ld, (1899 . 8 



Shell large, ovate in outline, rather compressed ; beak moder- 

 ately prominent, projecting beyond the hinge, which is nearly 

 straight. Anterior ear small, rounded to meet the hinge, rather 

 Hat, the shell rising rather abruptly to the swell of the umbo. 

 Anterior margin slightly sinuate ; antero-ventral margin broadly 

 rounded to the ventral portion of the shell, where it becomes 

 nearly straight, then rounding more abruptly to the posterior 

 ear, which is also rounded to the hinge. Greatest convexity a 

 trifle below the beak, but it is very slight. The surface is 

 marked by many fine, wavy, radiating stride of uniform size, ex- 

 tending from the beak to the ventral margin ; occasionally one 

 striation will be a trifle larger than another on the central por- 

 tion of the shell, but it soon loses itself, and on old individuals 

 the striae on the ventral border are all about equal. They in- 

 crease by implantation and are rather sharply defined, sepa- 

 rated by troughs from one to three times their width, and are 

 generally crossed by fine concentric lines or laminae. Right 

 valve unknown. Height, 62 mm. ; length, 69 mm. ; 9 length of 

 hinge, 23 mm. ; convexity, 10 mm. 



Range and distribution : Upper Coal Measures ; Turner, To- 

 peka, Auburn (Shawnee county). This species differs from 

 P. hawni in always having small, regular strire and shorter 

 hinge in the large individuals, as well as being a larger species. 



Pseudomonotis? robusta. Plate XIV, figs. 2-2c. 



Pseudomonotis f robusta sp.? var.? Beede, Kans. Univ. Quart., vm, p. 

 82, pi. xvm, ff. 2-2c, ('" 



This shell differs from the preceding in being much more con- 

 vex and arcuate, in having a longer hinge, higher umbo, beak 

 very much more compressed and scarcely distinct from the 



8. Through the kindness of Mr. Charles Schuclmrt. my attention was called to the description 

 of a species of this genus under the name tenuistriata, by Mr. Bittner. The paper was pub- 

 lished in the Jahrbuch dor K. K. Qeolog. Keichsanstalt, xlix, hefts iii and iv, (1899). The species 

 is from the Triassic of central Asia. As the paper probably appeared before my article, the 

 name of the Kansas species will have to be changed. Kansas, nsil L8 proposed as the new namo 

 of the species. 



9. The specimen used as the tvpe is somewhat crushed on the posterior end, making the shell 

 appear longer than it really is. The length given here is that of the specimen in its crushed 

 condition. 



