PLATE VII A— Coutinue.I. 

 SCENIDIUM HaLLI, Saftbld, VARIETY. 



Figs. 37, 38, 39. Three \-iews of a specimen ; sliowing- tiie great length of the hinge, the relatively low and 

 narrow cardinal areas and the somewhat coai-ser plications of the surface. X 6. 

 Trenton horizon. Cannon Falls, Minnesota. 



SCENIDIUM PYRAMIDALE, Hall. 



(See Plate VII, figs. 29, 30.) ■ . 



Fig. 40. A view of the pedicle-valve ; showing its elevation and the character of the surface plications. X S. 

 Fig. 41. A cardinal view of the same specimen ; showing the concave delthyrial plate or spondylium. X 5- 

 Fig. 42. A brachial valve of the same specimen. X 5. 

 Niagara gronp. Lockport, N. Y. 



SCENIDIUM AREOLA, QlieilSteclt. 



Fig. 43. A longitudinal section of the two valves ; showing the extension of the median plate into the cavity 

 of the pedicle-valve. (After Davidson.) 

 See for further information, Zeitschr. der deutsch. geolog. Gesellsch., vol. xxiii, plate viii ; and 

 Davidson, Devonian Brachiopoda, Suppl., plate iii, figs. 11-14. 



Genus ENTELETES, Fisher de Waldheim. 



Page -M. 



Enteletes hemiplicata, Hall. 



Fig. 44. An exterior view of a young individual in which the i-adial plications are rudimentary. 



Fig. 45. A similar view of a small example which bears a plication in the median sinus of the pedicle- 

 valve, with a cori-esponding fui-row on the fold of the opposite valve. 

 Upper Coal Measui-es. Kansas City, Missouri. 



Fig. 46. A similar view of a mature in<lividual ; showing the usual character of the sni-face. 

 Upper Coal Measures. Winterset, Iowa. 



Fig. 47. A cardinal view of an individual ; showing the area and delthyrium of the pedicle-valve and the 

 relative convexity of the two valves. 



Fig. 48. A profile of a very gibbous old individual. • 



Upper Coal Measures. Kansas City, Missouri. 



Fig. 49. A profile of the rosti-al portion of a pedicle-valve ; showing the great elevation of the median and 

 lateral septa, the edges of which are more or less broken. X 3. 



Fig. 50. A front view of the same specimen ; showing the piosition of the septa, of which the two outer 

 ones limit the area of muscular irLsertion. X 3. 



Fig. 51. The interior of the rostral portion of two valves in articulation. The median septum of the upper 

 or pedicle-valve is bi-oken oft", but the lateral septa are retained. In the brachial valve are seen 

 the high crural plates which are pi-oduced into strongly recurved crura. At ( j) is the small, 

 lobate cardinal process, and in the bottom of the valve a low median ridge. X 2. 



Fig. 52. A profile of the same specimen ; showing the articulation of the valves and elevation of the crura. 

 X 2. 



Upper Coal Measures. Winterset, Iowa. 



Enteletes Lamarcki, Fischer do Waklheim. 



Fig. 53. A cardinal view of an individual ; showing the area and delthyrium of the pedicle-valve. 

 Fig. 54. An enlargement of the fine striae of the sui-face, which are shown to be tubular, as in Rhipidomella 

 and ScHrzopHORiA. 



Upi^er Carboniferous limestone. Mjatschkowa, Rus.sia. 

 For further illustration of this genus, see Waagek, Salt-Range Fossils, vol. i, Y>t. 4 ; also, Meek, 

 U. S. Geological Survey, Final Report on Nebraska, pp. 177, 178, plates vi and viii. 



