PLATE LXX. 
(Figures 1, 2, 4-14 by E. Emmons ; 3, copy.) 
Genus PENTAMERUS, Soweeby. 
I*age 236. 
Pentamekus oblongus, Sowerby. 
See plales Ixviii, Ixix. 
Dorsal view of ati internal cast of a broadly ovate shell, with evenly convex valves. 
Niagai'a dolomites. Near Milwaukee, Wisconsin. 
A natural longitudinal section through both valves ; showing the comparatively short median sep¬ 
tum and septal i^lates, the projecting spondylium and crural processes. 
Clinton erroup. Rochester, New Ym’k. 
A copy of the original figure of this species given by Murchison in “Silurian System,” plate xix, 
figure 10. 
Dorsal view of a large, elongate-subovate shell, with trilobed surface, broadly shouldered um- 
bones and closely incurved and depressed ventral beak. 
Clinton group. Rochester, New Ycn'k. 
Pentamekus oblongus, var. subrectus, var. nov. 
See plates Ixviii, Ixix. 
Fig. 5. A somewhat weathered specimen in which the valves have been displaced from their normal posi¬ 
tion, exposing the sjiondylium of the pedicle-valve, and, by the removal of the rock, also show¬ 
ing a part of the united septal jilates of the brachial valve. This spondylioid condition of 
these plates is a normal feature of this variety. 
Niagara beds. Jones county, Iowa. 
Genus CAPELLINIA, gen. nov. 
Page 248. 
CaPELLINIA MIRA, Sp. BOV. 
Figs. 6, 7. Ventral and cardinal views of an average specimen ; showing the predominant convexity of the 
brachial valve, the smooth surface and the position and extent of the internal xilates. 
Fig. 8. Cardinal view of another example in which the convexity anil umbonal incurvature of the brachial 
valve are still more conspicuously developed. 
Fig. 9. Cardinal view of a pedicle-valve ; showing the inconspicuous, suberect beak and wide delthyrium. 
Fig. 10. Ventral view of the same specimen ; showing the length of the median septum. 
Fig. 11. Profile view of a normal individual; showing the relations of the valves. 
Figs. 12, 13. Ventral and profile views of anotner example in which the umbo of the pedicle-valve is ab¬ 
ruptly depressed. 
Fig. 14. A brachial valve, showing- the length of the septal plates and a low radial plication over the um¬ 
bonal i-egion. 
Niagara dolomites. Near Milwaukee, Wisconsin. 
Fig. 1. 
Fig. 2. 
Fig. 3. 
Fig. 4. 
