TRIASSIC PERIOD. 



435 



Fig. 654. 



Lily Encrinite, Encrinus liliiformis. Mollusks are numerous, and 

 among them are the first of the Ammonites. The Articulates are 

 confined to Crustaceans and Worms. 



Among Vertebrates, the Fishes are all 

 Ganoids or Selachians. 



The Reptiles include the gigantic Labyrin- 

 thodon, a scale-covered animal of a Batrachian 

 form, the skull of which was three or four 

 feet long, and the teeth three inches, — mag- 

 nitude enough for the Otozoum of the Con- 

 necticut valley. The tracks referred to a 

 genus named Chirotherium (because of a re- 

 semblance in form to the human hand) are 

 supposed to be those of a Labyrinthodon. 

 The rocks also contain remains of Swimming 

 Saurians (Enaliosaurs) and Lacertian Reptiles. 

 Remains of 12 species of Labyrinthodonts, 16 

 of Enaliosaurs, and 12 to 15 of other Saurians, 

 have been found. 



The species of Mammal, Microlestes antiquus 

 (fig. 663 A), is closely related to that of North 

 Carolina. 



Encrinus liliiformis. 



Characteristic Species.- 



1. Radiates. — Fig. 654, Encrinus liliiformis, from the European "Muschel- 

 kalk." The limestone in some places is mostly made of Crinoidal remains. 

 Aspidura loricata is a Star-fish related to the Ophiurag. 



2. Mollusks. — (a.) Brachiopods. — Terebratula vulgaris, Spirifer uncinatus, 

 etc. (b.) Conchifers. — Fig. 655, Avicula? socialis. Fig. 657, Myophoria lineata, of 

 the Trigonia family; also species of Gervillia, Avicula, Pecten, etc. (c.) Cep>halopods. 



Figs. 655-657. 



Conchifers.— Fig. 655, Avicula? socialis; 656, Estheria minuta; 657, Myophoria lineata. 



— Fig. 658, Ceratites nodosus, related to the Ammonites, but differing in the 

 greater simplicity of the lobes of the septa. Fig. 659, Ammonites tomatus, from 



