211 



Distinguishing Characters. — Lar<;'esize; robust and biil<2;- 

 iiig or gibbons character; moderately high, curved area of 

 the pedicle valve, which extends to the extremity of the 

 hinge line; similai*, but lower, area of the brachial valve; 

 mesial sinus, sub-angular above, broad rounded in front; 

 prominent rounded fold, with medial depression ; simple, 

 low, rounded plications; strongly pustulose or grannlose 

 surface. 



Found in the Encrinal limestone and the Demissa bed, at 

 Section 5, etc. (common) ; two feet below the Encrinal lime- 

 stone, at Section 6 (two specimens); shale below the 

 Trilobite beds, in Averv's Eavine, and on the Lake Shore 

 (rare) ; in the Calcareous bed, four feet below the Trilobite 

 beds; and the Pleurodictyum beds, in Avery's Ravine, and 

 on the Lake Shore (common); Nautilus bed, in Avery's 

 Ravine and Erie Cliff (rare) ; Strophalosia bed, Erie Cliff 

 (one specimen). 



Spirifek -GRANULOSUS, var. cLixTONi. Hall. (Fig. 118A.) 

 (Pal. N. Y., Vol. IT., p. 225, V\. XXXVIL ) 



Fig. 118A. Spirifer granulosa^, var. cUutuni. 

 Cfrom Hall). 



Dorsal. pri)flle, and ventral views 



Distinguishing Characters. — Sinus angular, cardinal ex- 

 tremities angular. 



Found in the Encrinal limestone. 



SpmiFEK AUDAGULUs. (Courad. ) (P^ig. 119.) (Pal. N. Y., 

 Vol. IV., p. 227, PI. XXXVIIL, S. medialis.) 



Distinguishing Characters. — Larger and more robust than 

 S. mucronatus, smaller than S. granulosus : valves ventri- 

 cose in old specimens ; hinge line commonly extended beyond 

 the width of the shell below; moderately, sometimes ex- 

 tremely, high concave area of pedicle valve ; incurved beak ; 



