Ptycho. 



832 



fossils in W. Canada, which Walcott (Amer. Jour. Sc. Sep., 

 1888) makes Middle Cambrian^ M, C. 



Ptchoparia {CrepMcephalus) haguei, Walcott, Bulletin 



^' * * plate 6. fig. 6, typical form of genus 

 ] Crephicephalus of Hall and Whit- 

 field. Middle Cambrian. M, C. 



Ptychoparia [housensis, Wal 

 cott. (Dec. 1888). Lower Cam 

 hrian^ L, C 



Ptychoparia {Crephicephalus) iowensis. Walcott, Bui- 



C. ^ 6* ^^^^^ ^^' ■^^' ^- ^- P^S® ^^' P^^^^ ^' ^^- ^' head, 

 without the loose cheeks; fig. 2 a, tail (pygi- 



dium). Middle Cambrian, Jf. C. 



Ptychoparia kingi. (Meek, sp.) Walcott 

 says (Dec. 1888) Lower Cambrian. L. C 



Ptychoparia miser. ( Conocephalites miser, Billings, 1861 , 



Geol. Vt. fig. 354; Geol. Oan. 1863, fig. 293; 

 Pal. Foss. I, plate 12, fig. 14.) Walcott, 

 Bull. No. 30, U. S. G. S. page 199, plate 27, 

 fig. 2, drawn from type specimen in collection 

 of Geol. Sur. Canada. Lower Cambrian on 

 the Straits of Belle Isle, similar to Georgian 

 rocks of Vermont. L. C 



Ptychoparia orestes, Hartt. ( Conocephalites halli, Hartt. 

 ^^ ^ Acad. Geol. Dawson, 3d ed. pp. 649, 654.) 

 * Walcott, Bulletin No.lO,U. S. G.S.page39, 

 plate 5, fig. 3, type specimen of Conoceph- 

 alites halli; fig. 3^, type of Conocephalites 

 oretes> Lower Cambrian (St. John) formation. L. C. 



