BRACHIOPODA. 
369 
which very gradually increase by implantation and become more numerous 
anteriorly. These plications are of slightly unequal size, which appears to be 
due to variation in the rate of their multiplication. In the umbonal regions 
the plications are obsolete. 
Niagara dolomites. Near Milwaukee, Wisconsin. 
CoNCHIDIUM CRASSIPLICA, Sp. nOV. 
PLATE LXVI, FIGS. 24, 25. 
Shell elongate, subelliptical in outline. Valves subequally convex, depressed 
above; cardinal slopes broad and abrupt on both. Umbo of the pedicle-valve 
erect, not prominent; surface slightly elevated medially. Umbo of brachial 
valve depressed, apex concealed; median region depressed anteriorly; surface 
of both valves bearing broad rounded plications, separated by deep grooves. 
Of these plications there are from eight to ten on each valve over the pallial 
region; by dichotomizing these become more numerous anteriorly. 
Niagara group. Near Louisville, Kentucky. 
CoNCHiDiuM Georgia, sp. nov. 
PLATE LXVr, FIGS. 18, 19. 
Pedicle-valve unknown; brachial valve trilobed by the development of a 
strong median fold which extends from apex to margin, and is sharply delim¬ 
ited by abrujjt lateral slopes. The sides of the valve are convex, rather narrow, 
and slope abruptly to the lateral margins. Umbo full and incurved. Surface 
covered with numerous duplicating plications, of which from fifteen to twenty 
may be counted on each side at the margins, and twelve to fourteen in the 
fold. 
Clinton group. Trenton, Georgia. 
Capellinia MIRA, sp. nov. 
PLATE LXX, FIGS. 6-14. 
(See pages 248, 249.) 
