MESOZOIC TIME TRIASSIC AND JURASSIC. 



771 



1253. 



1253-1257. 



1254. 



1258, 1259 ; an Ammonite, from tlie Keuper, is the Cladiscites tornatus Braun. 



The genus Choristoceras, of the Ammonite family, contains Triassic species 



that are like Cera?^Yes 

 in the partitions, but 

 the whorls of the 

 shell are not con- 

 tiguous, — a feature 

 here first presented 

 under the type ; and 

 Cochloceras of the 

 Trias has a turreted 

 shell like Turrilites 

 of the Cretaceous. 



2. Crustaceans, 

 Insects. — Ostra- 

 coids are common. 

 Estheria mi nut a 

 Goldf. (Fig. 1257) 

 abounds in a stra- 

 tum of the Lower 

 Trias, and has given 

 rise to the name Es- 

 theria shales. Macrurans, allied to the Crawfish or Lobsters, occur, one of 

 which is Pemphix Sueurii Desm., of the Muschelkalk (Fig. 1262). 



CRiNorD. — Fig-. 1253, Encrinus liliiformis. Lamellibranchs. — Fig. 1254, 

 Gervillia socialis ; 1255, Myophoria lineata ; 1256, Avicula contorta. Ostra- 

 coro. — Fig. 1257, Estheria minuta. Figs. 1253, 1257, D'Orbigny ; 1254, 

 Vogt ; 1255, LyeU ; 1256, Fortlock. 



1258. 



12.58-1261. 



1262. 



1261. 



1260. 







Cephalopods. — Fig. 125S, Ceratites nodosus ; 12.59, dorsal view of portion of 

 same, slio-\ving the dorsal lobes of the septa ; 1260, Cladiscites tornatus ; 

 1261, side view of same (xi). Figs. 1258, 1259, D'Orbigny; 1260, 1261, 

 from Vogt. 



Pemphix Sueurii, 

 from Naumann. 



Insects of the Trias are Cockroaches (Orthopters) of 

 both paleeic and modern type ; several true Neuropters ; and Beetles or 

 Coleopters of the Curculio (Weevil) family, as Curculionites prodromus Hear, 

 and of Chrysomelids and Buprestids, from the Lower Keuper. 



