96 PALEONTOLOGY 



emnites, Acanthoteuthis, Helicerus, Conoteuthis, Cocco- 

 teuthis, Belosepia, Spirliurostra, Beloptera, Beleinnosis. 



Province IV.— VERTEBRATA. 



There is an enormous series of subaqueous sediment, 

 originally composed of mud, sand, or pebbles, the successive 

 bottoms of a former sea, derived from pre-existing rocks, 

 which has not undergone any change from heat, and in which 

 no trace of organic life has yet been detected. These non- 

 fossiliferous, non-crystalline, sedimentary beds form, in all 

 countries where they have yet been examined, the base-rocks 

 on which the Cambrian or oldest Silurian strata rest. 



Whether they be significative of ocean abysses never 

 reached by the remains of coeval living beings, or whether 

 they truly indicate the period antecedent to the beginning of 

 life on tliis planet, are questions of the deepest significance, 

 and demanding much farther observation before they can be 

 authoritatively answered. 



It has been shown that every type of invertebrate animal 

 is represented in the superimposed stratified deposits called 

 Cambrian and lower Silurian. 



An important work,* embodying the labours of the 

 accomplished naturalist and acute observer, Dr. Christian H. 

 Pander, has recently been published by the Russian govern- 

 ment, descriptive of the fossil fishes of the Silurian formations 

 of that empire. Of some hundred fossils described and 

 beautifully figured in this work, and referred to different 

 genera and species of fishes, from lower Silurian rocks, the 

 writer, after the closest comparison and consideration of the 

 evidence, is disposed to regard only those referred by Pander 

 to the genera Ctcnognatlms, Cordylodus, and Gnathodus, as 



* Monographic der Fossilen Fische (Untersilv/rische Fische Conodonhn. 

 etc.), 4to, Petcrsburgh, 185(3. 



