200 



PALEOZOIC TIME. 



nella groups, — the same families that were represented in the early 

 Calciferous epoch. The genera Rhynchonella, which began in the era 



Figs. 326-340. 



Brachiopods — Figs. 326, 327, Orthis lynx; 328, 0. oecidentalis ; 329, 0. testudinaria ; 330,0. 

 tricenaria; 331, Leptasna sericea; 332, Strophoniena (Leptaena) wwjesa-; 333, Stroph. alternata; 

 334, 335, 336, Rhynchonella capax ; 337, 338, Rhynchonella (?)bisulcata; 339, Obolus filosus ; 340, 

 Lingula quadrata. 



of the Quebec group, and Crania (Fig. 242), of the Trenton, have 

 representatives in modern seas. 



Orthocerata (Figs. 353-355), of the tribe of Cephalopods, were 

 very numerous, and some were ten to fifteen feet long. Fig. 353 rep- 

 Figs. 341-343. 



Lamellibranchs. — Fig. 341, Ayicula(?) Trentonensis ; 342, Ambonychia bellistriata; 343, Telli- 



nomya nasuta. 



resents a portion of one of these long conical (or straight horn- 

 shaped, as the name signifies, p. 187) shells, and exhibits the parti- 

 tions dividing it interiorly into chambers ; and, in Fig. 353 a, one of 



