615 



Pemphi. 



Pemphigaspis buUata. (Hall, 16th An. Rt. N. Y. State 



Cab. p. 221.) Walcott, Bull. 30, 

 p. 154, remarks that if this be a 

 species of Microdiscus^ it is the only 

 one known from the Upper Cam- 

 brian (Potsdam) formation. Note. 

 If so, all the Microdisci become 

 Pemphigaspes ; for, Emmons' orig- 

 inal Microdiscus was a Trinucleus. ( W.) 



Pentacrinites Jiamptoni. See Crinoid. Illh, 

 Pentamerella arata {Pentamerus aratus ; Atrypa arata ; 



Mill a 



Atrypa octocostata ; Conrad, An. Rt. N. Y. 1841.) Hall, Pal. 

 N. Y., Vol. 4, 1867. Figure taken from Geol. Canada, 1863, 

 page 370, fig. 389, a, b, ventral and dorsal valves of a small 

 specimen ; c, d, dorsal and side views of a large one. — Scho- 

 harie grit diwdi Upper Helderherg, Vllh^ Villa. 



Pentamerella micula. Hall, Pal. N. Y., Vol. 4,1867, Ham- 

 ilton. Found in Pennsylvania, Blair Co. Bell's Mills, collec- 

 tions. Spec. 805-15, in Hamilton shale. VIII c. 



Pentamerus barrandi, Billings. Canada Rt. of Pros., 



1857, 



Geol. 



Can. 



1863, 



page 316, 



f.327(X,J. 



IV-V. 



12 



^eo 



