254 



PALEOZOIC TIME — UPPER SILURIAN. 



2. Mollusks. — Brachiopods. — Fig. 419, Strophomena radiata Vanuxem, 

 of the Catskill shaly limestone; 420, 421, Rhynchonella ventricosa, of the 



Figs. 419-430. 



Brachiopods.— Fig. 419, Strophomena radiata; 420, 421, Rhynchonella ventricosa; 422, 423, 

 Pentamerus galeatus; 424, 425, P. pseudo-galeatus ; 426, Eatonia singnlaris; 427,Merista? 

 sulcata; 428, Orthis varica; 429, Spirifer macropleurus ; 430, Merista levis. 



Upper Pentamerus ; 422, 423, Pentamerus galeatus, of the Lower Pentamerus ; 

 424, 425, P. j^seudo-galeatus, of the Upper Pentamerus; 426, Eatonia singxdaris, 

 of the Catskill shaly ; 427, Merista f sulcata, of the Water-lime ; 428, Orthis 

 varica, of the Catskill shaly; 429, Spirifer macropleurus, ibid.; 430, Merista 

 levis, ibid. 



There are also Conchifers of the genus Avicula and others related; Gastero- 

 pods of the genera Platyceras, Platyostoma, etc. Also the Pteropod Tentacxdites 

 ornatus (figs. 431, 432, the latter natural size). 



3. Articulates (a.) Trilobites. — Fig. 244 C, Dalmania pleuroptyx ; 



others of the genera Galymene, Gheirurus, Asaphus. (b.) Other Entomostracans. — 

 Fig. 433, Eurypterus remipes, of the Water-lime, natural size, from a small speci- 

 men from the cabinet of E. Jewett : specimens from Buffalo, N.Y., are some- 



