231 



Camarotcechia dotis. Hall. (Fig. 141.) (Pal. X. V.. 

 Vol. IV., p. 344, PL LI V.) 



Distinguishing Characters. — Sub-triangula i-ly ovate out- 

 line; rounded or .semi-truncate front; 

 shallow sinus and moderate fold ; plica- 

 tions rounded or sub-angular, about 

 eighteen in number (in full-grown speci- 

 mens), those of the gibbous brachial 

 valve abruptly curved down to the pedi- 

 cle valve; plications, commonly three or J£; 1 %STSSS "tf* I 



,..,-,. . n j. ,i characteristic specimen. 



tour in the sinus and tour or five on the from the Nautilus bed. x j. 



,. , ^ (Original.) 



told. 



Found in the Encrinal limestone, at Section 5 (rare) ; Nau- 

 tilus bed, in Avery's Creek and north shore sections (abun- 

 dant) ; Strophalosia bed (?), in Erie Cliff. 



Camarotcechia congregata. (Conrad.) (Fig. 141 A.) 

 (Pal. N. Y, Vol. IV., p. 341, PL LIV.) 



Distinguishing Characters. — Robust character; abrupt 

 curvature of sides; moderate fold and sinus; conspicuous 



Fig. 141 A. Camarotcechia congregata. Profile, cardinal, front, dorsal, and ventral 

 views of an individual (from Hall.) 



character of sinus at the front ; three or four plications in 

 sinus and four or five on mesial fold. 



Found in a Calcareous band in the Hamilton group, at 

 Alden, Erie Co. (Hall); and at Eighteen Mile Creek. (Coll. 

 Am. Mus. Nat. Hist. Xew York.) 



