164 



THE LIAS AMMONITES, 



TaUe shoioing the extension of the Upper Lias in the British Islands, Belgium, France, 

 Switzerland, Germany, Austria, and Italy, with indications of the Toarcian Ammonite^ 

 Zones found in some typical regions of the European area. 



Ammonite Zones 



of the 



Upper Lias. 



British 

 Islands. 



M 



France, 

 Depaetments of. 



Switzer- 

 land. 



<! 

 Pi 

 CS 



I 



< 



5 

 < 



EH 



1— 1 



B 

 a 



c 



-d 



•-a 

 c 



o 



ii) 



3 



s 



a 



o 



ci 

 > 



O 



P 



'73 



o 



c 

 a 





a 



c 

 o 



0) 



o 

 52 



3 





b'ii 



S 

 1 



a. 

 < 



'a 



a 



OPALINUM 



* 

 * 





* 



* 

 * 



* 

 * 

 * 

 * 



* 

 * 

 » 



* 

 * 



* 

 * 



* 

 * 



* 

 * 



* 

 * 



* 

 * 

 * 



? 



* 



* 



? 

 * 



* 

 * 

 * 

 * 



* 

 * 

 * 

 * 



* 

 * 

 * 



* 

 * 



JURENSE 



BIFRONS 



SERPENTINUM 



This table concludes our sketch of the Lias formation, so rich in new and varied forms 

 of animal life, which all became extinct with its close. In taking a retrospective glance 

 at this chapter of the Geological Record, probably the most complete of all the Mesozoic 

 formations, one is forcibly struck with the number of new, remarkable, and varied animal 

 forms it contains, of which we find neither traces of ancestry nor natural affinities in any 

 of the older strata. In its basement -bed the teeth of the oldest known Mammal, 

 Microlestes, were discovered, and in its different horizons the remains of Reptiles of the 

 most singular structure are found. The Enaliosaurians comprise in a single organism the 

 most diverse anatomical characters ; the vertebral column of a fish united to the body 

 of a lizard, having the skull, jaws, and teeth of a crocodile, with the paddles of Cetacea 

 articulated to the scapular arch of a Platypus. The Pterodactylians have affinities with 

 birds and bats through the mechanism of their anterior extremities, the phalanges of the 

 fifth finger being enlarged and elongated to form a rod for supporting a wide-spreading 

 membranous wing, whilst the rest of the hand retained the reptilian type. The Ganoid 

 Pishes belong to genera that are nearly all special to the Lias, and they are as remarkable 

 for the beauty and novelty of their forms as for the fine state of preservation in which 

 they are found. The MoUuscan Faunas are singularly characteristic of the different 

 zones ; and the Cephalopods, above all others, are the most important class, from the cer- 

 tainty with which these divisions of time are characterised by them, each new group 

 making its appearance in succession, and passing away to give place to other generic 

 forms destined to succeed it in time and space. 



