Evietria? Osacensis, Swallow. 
Fig. 7. A dorsal view*of an"imperfect example. 
Fig. 9. A portion of the exterior of the shell, enlarged. The lower part of the 
figure represents the punctations of the outer surface where it has 
been exposed and somewhat weathered ; above is the surface of one 
of the inner layers covered with fine pustules. x 5. 
Choteau limestone. Pike county, Missouri. 
Eumetria verA, Hall. 
Fig. 8. The umbonal ‘portion of a specimen which has been broken longitudi- 
nally nearly in the median axis. On the upper portion is exposed 
the surface of the more distant of the two crural plates, flattened 
below by the transverse concave plate and the upward extension of 
the nearer of the crural plates. The outer gash is retained about 
the beak of the pedicle-valve. 
Fig. 12. The umbonal portion of an old shell enlarged to show the thickening 
of the deltaria, which have become conspicuously protuberant. 
This thickening has been accompanied by a similar growth on the 
cardinal expansions of the brachial valve.  X 2. 
Chester limestone. Crittenden county, Kentucky. 
HUSTEDIA, Hatt. 
Page 797. 
Hustrp1a Mormonti, Marcou. 
Figs. 13, 14, 15. Dorsal, profile and anterior views of a normal specimen. 
Figs. 16, 17. Enlarged views of a similar exemple.  X 2. 
Fig. 18. An enlargement of the umbonal region; showing the coalesced 
deltaria. x 5. 
Fig, 19. A preparation of the hinge-plate; showing the elevation of the large 
recurved central part, the crural lobes and the projection of the 
anterior ligulate process. » 5. 
Fig. 20. The same viewed in profile. 
Coal measures. Near Kansas City, Missouri. 
ACAMBONA, Wuirr. 
Page 797. 
Acampona PRIMA, White. 
Figs. 21, 22. Dorsal and profile views of an incomplete specimen which is 
regarded as belonging to this species. 
Burlington limestone. Burlington, Iowa. 
UNCINELLA, Waacen. 
Page 794. 
UNcINELLA Typica, Waagen. 
Figs. 23, 24, 25. Dorsal, profile and ventral views of a typical example, 
(WAAGEN). 
Permo-carboniferous. Salt Range, India. 
227 
