162 PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol.. xxx. 



BAIRDIA BEEDEI ABRUPTA, new variety. 

 Plate XI, figs. 21, 22. 



Length 1.28 mm, height 0.72 mm, thickness 0.47 mm. 



Longer than the typical form of the species, but with a more 

 abruptly tapering and therefore blunter and relatively shorter pos- 

 terior end. Although the dorsal and ventral parts are nearly the 

 same in the two varieties, the outlines of their respective smaller 

 (right) \'alves seem to difi'er, the height at the post-cardinal angle 

 being proportionally greater in the variety ahnipta than in the typical 

 variet}'. The last difference possibly may be, in part at least, 

 accounted for by individual differences in the amount of dorsal 

 overlap. 



Though still too short and with blunter extremities, this variety 

 nevertheless is much nearer B. pJshela McCoy than is the typical form 

 of the species. At the same time it is farther from B. cc>itri«'»><!,s 

 ririch. 



Formation and locality. — Associated with typical B. hecde! and 

 many other ostracods in the Cottonwood shales, 2 miles east of Cotton- 

 wood Falls, Kansas. 



IIoIott/p.'.—C'At. No. 35635, U.S.N.M. 



Family CYPRIDINID.E. 



Genus CYPRIDINA Milne Edwards. 



CYPRIDINA SUBOVATA, new species. 



Plate XI. fig. 23-2(i. 



Length of an average example 3.8 mm., height 2.9 nmi., thickness 

 2.1 mm. 



Carapace compressed subglobular, l)roadly oval in outline, generally 

 wider behind than anteriorly, and deeply notched in front, with a 

 sharp l)eak a))o\'e and a well-marked angulation below. Valves 

 slightly mie(iual, the outline of the left being somewhat produced in 

 the post-cardinal portion and thei'efore less regularly curved than in 

 the right valve. In end and edge views this portion of the left valve 

 also projcH'ts ])eyond the plane of the remaining portions of the edge 

 and pi'()t)ably overlaps the corresponding part of the edge of the right 

 valve. Surface of valves smooth, moderately convex, the convexity 

 not (juite synnnetrical, t)eing greater in the dorsal part than in the cen- 

 tral and ventral portions. Partially exfoliated shells expose the 

 muscle spot. This is ovate, radiall}' striated, and smaller and farther 

 removed from the center of the valves than usual. Dividing the 

 valve into four e(jual parts, the whole of the scar line lies within tiie 

 antero- ventral fourth. 



The slight overlap of the post-dorsal edge of the left valve possibly 

 allies this species to lintonioconc/ms^ in which the same valve overlaps 



