I'LATE VllA— CoutiiuiUil. 



ScENiDiUM Halli, SaH'onl, vakiety. 



Figs. 37, 38, 39. Three views of a specimen ; showing the great length of the hinge, the reliitively low and 

 narrow cardinal areas and the somewhat coarser iilications of the surface. X 0. 

 Trenton horizon. Camwn Falls, Minnesota. 



SCENIDIUM PVUAMIDALK, ll.lll. 



(See Plate VII, Hgs. 29, 30.) 

 Fig. 40. A view of the pedicle-valve ; showing its elev.ition and the character of the surface plications. X •'). 

 Fig. 41. A cardinal view of the same specimen ; showing the concave delthyrial plate or spondylium. X •'>. 

 Fig. 42. A brachial valve of the same spe<-imen. X ^^ 

 Niagara group. Lockport, N. Y. 



SCENIDIUM AREOLA, Queilslcdl. 



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, fig.s. 11-14. 



Genus ENTELKTES, Fishek de VValdheim. 



Page 2U. 



Enteletes hemiplicata, Hall. 



Fig. 44. An exterior view of a young individual in which the radial plications are rudimentai-y. 



Fig. 4,1. A similar view of a small example which bears a plication in the median sinus of the jiedicle- 



valve, with a corresponding furrow on the fold of the opposite valve. 

 Upper Coal Measures, Kansas City, Missoari. 

 Fig. 46. A similar view of a mature inilividual ; showing the usual character of the surface. 



Upper Coal Measures. IVintei-sel, Iowa. 

 Fig. 47. A cai'dinal view of an individual ; showing the areii and delthyriinn of the pedicle-valve and the 



relative convexity of the two valves. 

 Fig. 48. A profile of a very gibbous old indivi<lual. 



Upper Coal Measures. Kansas City, Miisoiiri. 

 Fig. 49. A pi'ofile of the rostral portion of a pedicle- v.alve ; showing the great elevation of the median and 



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

 Fig. .'JO. A front view of the same specimen ; showing the position of the septa, of which the two outer 



ones limit tlie area of muscular insertion. X 3. 

 Fig, 51, The interior of the rostral [lortion of two valves in articulation. The median septum of the upper 



or pedicle-valve is liroken otf, but the latei'al septa are retained. In the br.achial valve are seen 



the high crural plates whi('h are produced into strongly recurved ci'ura. At ( j) is the small, 



lobate cardinal process, and in the Inittom 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. Wiiitersct. loiea. 



Enteletes Lamaucki, Fisclicr de W'alilliciin, 



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

 Fig. 54. An enlargement of the fine strife of the surface, which are shown to be tubular, as in Rhipidomella 

 and ScHizopHORiA. 



Upper Carboniferous limestone. MJaXsclikowa. Russia. 

 For further illustration of this genus, .see Waaoen, Salt-Range Fo.ssils, vol, i, pt. 4 ; also. Meek, 

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



