254 



PALEOZOIC TIME — UPPER SILURIAN. 



J\ 





2. Molllisks. — 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 singularis; 427, Merista? 

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



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

 424, 425, P. pseudo-galeatus, of the Upper Pentamerus ; 426, Eatonia singularis, 

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

 varica, of the Catskill shaly; 429, Spirifer niacropleurus, ihid. ; 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 Tentaculitcs 

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



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



others of the genera Calymene, Cheirvrus, Asaphus. (b.) Other Entomostracans. — 

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

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



