Khyn. 



884 



3b 



3d 



furnace, Orbisonia (000, p. 205, spec. 602-3). But, in Tioga 

 Co. Sherwood's spec. 854-10, was got from Upper Chemung 

 strata^ and assigned to this species by 0. B. Simpson, 1889. 

 If this determination be correct, then this species in Pennsyl- 

 vania ranges from Lower Helderierg up to Chemung. VI to 

 Vlllg, 



Rhynchonella anticostiensis, Billings, Pal. Foss. Vol. 1, 



Ui A.CC h^^Ak ^ jUl^^^ ^^^^- Geol. Canada, IS'-S, page 



211, fig. 212, a^ dorsal valve; 5, 

 side view; c^ ventral valve. Hud- 

 son river (Loraine) formation in 



the Gulf of St. Lawrence. /// 5. 



Rhynchonella bidens ? Terehratula Udentata^ Dalman, 

 y/ CL, Clinton, -i^ 



Hisinger, etc. ; T. decemplicata, MnrGhison^ Si\. Syst. ; Atripa 

 hidens, Hall. Pal. N. Y. Vol. 2, 1852, page 69, plate 23, figs, 

 a, J, ventral valve of two specimens of diff'erent age ; c, dj front 

 and profile of the larger one ; from the Clinton at Lockport, 

 N. Y. This species closely resembles the much older Trenton 

 species Atrypa dentata^ differing from it in having a shallower 

 sinus, less raised in front, and in having 5 or more folds on each 

 side, instead of 4. ' '' They may readily be confounded on casual 

 examination." (Hall.) In Pennsylvania, doubtfully recog- 

 nized by O. E. Hall, among his collections at McKee's fossil 

 ore bank, Ferguson Valley, Mifflin Co., in shales over the ore 

 bed. (000, p. 104, spec. 501-37.) Va. 



Rhynchonella brevirostris, Hall. {Terehratula Irevi- 

 yj, 324 rostris^ Sowerby, 1839.) Pentamerushrevirostris^ 

 Sowerby, 1839, S. A. Miller.) Geol. Canada, 1863, 

 page 315, fig. 324. Niagara limestone. Vh. 



Rhynchonella camura, Hall. Figure given in Geology of 

 V 322 . Canada, 1863, page 315, fig. 322, as from the'strata 

 beneath the Niagara limestone of Upper Canada. 

 Clinton. V a. 



