224 



PALEOZOIC TIME. 



shaped Lingulella, L. cuneata (Fig. 399). Two of the Lamellibranchs 

 of the same beds are represented in Figs. 400, 401, and two Gastero- 

 pods in Figs. 402, 403. A considerable number of the Medina species 

 are identical with the Clinton. 



The following figures represent fossils of the Clinton group, — 



Figs. 405-409. 

 406 ^aumrnm^. (0^ 



Radiates. — Figs. 405, 406, Zaphrentis bilateralis ; 407, 407, Palasocyclus rotuloides ; 408, a, Chae- 

 tetes ; 409, a, Graptolithus Clintonensis. 



Figs. 405, 406, one of the common corals, a cup coral or Cyatho- 

 phylloid, of the genus Zaphrentis ; 407, a small Echinoid ; 408, a fine- 



Figs. 410-422 



Mollusks. —Figs. 410, a, Fenestella (?) prisca; 411, Pentamerus oblongus ; 412, 413, part of casts 

 of the interior; 414, 415, Atrypa reticularis; 416, 417, Athyris (formerly Atrypa) congesta ; 

 418, Chonetes cornuta ; 419, Avicula rhomboidea ; 420, Cyclonema cancellation ; 421, track of a 

 Lamellibranch (X}j) ; 422, track of an Aunelid ? ( X}£)- 



columnar coral, of the genus Chcetetes ; 409, a Graptolite ; 410, a 

 delicate reticulated Bryozoan coral ; 411 to 418, some of the Brachio- 



