IM.ATh; V A— ConCinacil. 



OiiTUis POUCATA, McCoy. 



Figs. 20, 21. Brachial and jsiofile views of an average example; showing the rotundity of the brachial valve 

 and the resupiiialion of the opposite beak. 



Middle Silurian. Junction Cliff, Anticosti. 

 Foi- further illustration, see Davidson, Silurian Brachiopoda, plate xxxii, figs. 12-20. 



OKTHOSTROPHIA, Hall. 



Page 199. 



Orthis Halli. Siirtbrd (? = 0. s()-op/iome7ioicle.s, Hull). 



Fig. 22. A view of the pedicle-valve. 



Fig. 23. A cardinal view of the conjoined valves of the same sjiociinen. 

 Lower Ilelderberg group. P&rry county, Tennessee. 



OUTHIS STKOPHOMENOIDES, Hall. 

 See Plate VI, figs. 32-34. 



Fig. 24. The exterior of a brachial valve. 



Fig. 25. A cardinal view of the same specimen ; showing greatei' convexity than the preceeding species. 



(The relative position of the valves as representeil in the figures 23 and 25 is revei-sed.) 

 Fig. 26. The interior of a brachial valve ; showing the character of the cardinal process, muscular area, 



ovarian and vasculai' markings. 

 Fi". 27. The interior of the opposite valve. The muscular area is greatly thickened and is divisible into 

 the adductor ami diductoi' elements; the vascular sinuses are also very distinct. 

 Lower Helderberg group JVear Clarksville, N. T. 

 For further illusti'ation, see Palseontology of New Tork, Volume III, jilate xxiii, fig. 7. 



PL^SIOMYS, NOM. NOV. 



Page 196. 



Oethis deflecta. Conrad. 



Pigs. 28, 29. The exterior of the brachial and pedicle-valves. 



Fig. 30. A cardinal view of the same sjiecimen ; showing the elevation of the area, the convex deltidium, 

 and the convexity of the brachial valve. 



Trenton horizon. Dixun, Illinois. 

 For further illustration, see Palseontology of New Yoi-k, Volume I, plate xxxiB, fig. 5. 



Orthis loricula, sp. iiov. 



Fig. 31. The cardinal area of the pedicle-valve ; showing the deltidium. 



Fig. 32. The exterior of the pedicle-valve. 



Fig. 33. The interior of the V)rachial valve. The delthyrinm is filled by a callosity which also supports 



the crural plates and the linear cardinal pi'ocess ; the deltidium is also present in an incipient 



condition. 

 Fig. 34. The interior of the pedicle-valve ; showing the character of the muscular area, ovarian markings, 



etc. 



Galena limestone. Fountain, Mmne.iota, 



Ortiiis HoLSTOxr, Safford. 



Fig. 35. Profile of the type specimen. 



Fig. 3t). Cai-dinal view of the same ; showing the wide delthyrinm and elevated area of the pedicle-valve. 



Fig. 37. A view of the brachial valve of the same specimen. 



Trenton horizon. Near Knoxville, Ttnnesee. 



Orthis Saffordi, sp. nov. 



Figs. 38, 39, 40. 'ITiree views of the exteiior of a specimen ; showing its general foi-m and the character of 

 its surface markings. 



Trenton horizon. Near Knoxville, Tennessee. 



