531 



Orthis. 



Orthis plicatella, var. triplicatella Hall, Pal. Ohio, Vol. 1 



8a 



8 b 



SH- 



1873, page 109, plate 8, figs, S a i dorsal ventral, 8 o, hinge 

 view, to show thevery low area, as compared with the species 

 figs. 7 f and 6c; 8 6?, profile 8 6, magnified surface of shell. — 

 Cincinnati group ^ III, 



Orthis porcata, McCoy. Silurian Fossils ot Ireland, 1846. 



Trenton^ Hudson river and Mid- 

 dle Silurian, Geology of Canada, 

 1863, page 312, figs. 319 a, 5, dor- 

 sal and side views of a specimen 

 from the Medina- Clinton series of 

 j^w;/ West Canada. IV-V, 



Orthis porcia, Billings. Canad. Nat. & Geol. Vol. 4, 1859 

 II 7 ^ Geology of Canada, 1863, page 130, figs 



58 «, ventral valve ; 5, side view ; c, 

 magnified portion of surface of shell. 

 Chazy formation^ II h, 



Orthis punetostriata. Hall, Pal. N. Y. Vol. 2, 1852, Nia- 

 gara,^ F5.— Specimen 604-6 (00, p. 234) in collections of Fel- 

 lows & Genth, 1875, at Mansing's quarry, near Hazardville 

 Carbon Co., Pa., from what we Q2i\\Lovjer Helderherg leds^ F/.' 



Orthis quadricostata. See Rhynchonella quadricostata, 

 Vllle, 



Orthis resupinata. (Anomites resupinatus ; Spirifera 



Ceo L. Can . 



Vllf.cL. 



yui d 



H.92: 



resupinata ; Terebra- 

 tula resupinata; Or- 

 this tulliensis.) Hall, 

 page 215, fig. 92, 2. 

 Vanuxem, page 163, 

 fig. 41, 2. (Pal. Foss. 

 xxvii, f. 115.) (Martin, 

 Petrefact. Derb. Car- 



