PALEONTOLOGY. 277 



Maypo in Chili), and D'Orbigny lias "described Ammonites 

 and Gryphites from the Himalaya and the Indian plains of 

 Cutch, these remains being identical with those found in the 

 old Jurassic sea of Germany and France. 



The strata which are distinguished by definite kinds of pet- 

 rifactions, or by the fragments contained within them, form 

 a geognostic horizon, by which the inquirer may guide his 

 steps, and arrive at certain conclusions regarding the identity 

 or relative age of the formations, the periodic recurrence of 

 certain strata, their parallelism, or their total suppression. If 

 we classify the type of the sedimentary structures in the sim- 

 plest mode of generalization, we arrive at the following series 

 in proceeding from below upward : 



1. The so-called tra7isitmn rocks, in the two divisions of 

 upper and lower graywacke (silurian and devonian systems), 

 the latter being formerly designated as old red sandstone. 



2. The lower trias* comprising mountain limestone, coal- 

 measures, together with the lower new red sandstone (Todt- 

 liegende and Zechstein).t 



3. The upper trias, including variegated sandstone, t mu* 

 chelkalk, and keuper. 



4. Jura limestone (lias and oolite). 



5. Green sandstone, the quader sanstein, upper and lower 

 chalk, terminating the secondary formations, which begin with 

 limestone. 



6. Tertiary forynations in three divisions, distinguished as 

 granular limestone, the lignites, and the sub-Apennine gravei 

 of Italy. 



Then follow, in the alluvial beds, the colossal bones of the 

 mammalia of the primitive world, as the mastodon, dinothe- 



* Queustedt, Flotzgebirge Wurtembergs, 1843, s. 13. 



t IMurchison makes two divisions of the hunter sandstone, the upper 

 being the same as the trias of Alberti, while of the lower division, to 

 which the Vosges sandstone of Elie de Beaumont belongs — the zeck' 

 stein and the todtliegende — he forms his Permian system. He makes 

 the secondary formations commence with the upper trias, that is to say, 

 with the upper division of our (German) bunter sandstone, w hile the 

 Permian system, the carboniferous or mountain limestone, and the 

 devonian and silurian sti'ata, constitute his palaeozoic formations. Ac- 

 cording to these views, the chalk and Jura constitute the upper, and 

 the keuper, the muschelkalk, and the hunter sandstone the lower sec- 

 ondary formations, while the Permian system and the carboniferous 

 limestone are the upper, and the devonian and silurian strata are the 

 lower palaeozoic fonnation. The fundamental principles of this general 

 classification are developed in the great work in which this indefaliga« 

 ble British geologist purposes to describe the geology of a large part of 

 Eastern Europe. 



