428 



MESOZOIC TIME. 



Characteristic Species. 



Fig. 754. 



1. Radiates. — Fig. 740, Encrinus liliiformis Schlot., from the European " Mus- 

 ■chelkalk." The limestone, in some places, is largely made up of Crinoidal remains. 

 Aspidura loricata Ag , is a Star fish related to the Ophiura. 



2. Mollusks. — («..) Brachiopods. — Terebratula vulgaris Schlot., Spirifer Miin- 

 *ri Dav., etc. (b.) Conchifers. — Fig. 741, Gervillia socialis Schlot. Fig. 742, Myo- 

 phwia lineata Mii.. of the Trigonia family; also Lima striata Desh., species of Avicula, 

 Pecten, etc. (c.) Cephaiopods. Fig. 744, Ceratites nodosus Schlot., related to the Am- 

 monites (p. 400); 745, view of back of shell, showing shape of pockets: Fig. 746, 

 Ammonites tornatus Braun, from the St. Cassian beds; 747, side view of same. Species 

 ■of Orthoceras have been described from the same beds. 



3. Articulates. — (a.) Crustaceans. — Ostracoids: Fig. 743, 

 Estheria (Posidonomya) minuta, Morris. — Macrourans: Fig. 754, 

 Pemphix Sueurii Mey., a species near the Crawfish (genus Asta- 

 cus). — (b.) Insects. — Species of Curculionites, Glaphyroptera, etc. 



4. Vertebrates. — ■ (a.) Fishes. —Among Hybodont Selachians, 

 Fig. 509, Hybodus pHcatilis Ag. ; Fig. 508, E. minor Ag. Among 

 Cestracionts, species of Acrodus, Ceratodus, etc. Ganoids, especially 

 of the genera Saurichthys, Gyrolepis, Amblypterus, and Pakeoniscus, 

 the last of the heterocercal species; and, of the Pycnodont division, 

 Pycnodus gigas Ag., etc. 



(b.) Amphibians of the Ldbyrinthodont tribe : Fig. 748, Mastodon- 

 saurus giganteus Jag., reduced to one twelfth the natural size; Fig. 

 749, one of the teeth, reduced one half; they have the Labyrinthine 

 structure, explained on p. 264 ; Fig. 750, prints of the fore and hind 

 feet of a Cheirotherium, one twelfth natural size, from Hildburg- 

 hausen, Saxony, supposed to be those of a Mastodonsaurus. 



The larger track in one was eight inches long, with a stride of four 

 inches; in another, twelve inches long. Similar tracks have been 

 found at Storton, England. Capitosaurus, Trematosaurus are names 

 Pemphix Sueurii. of othe] . great Lab yrinthodonts of Europe. 



(c. ) True Reptiles. — Enaliosaurs (or Sea-Saurians), of the genera Simosaur, Notho- 

 saur, Pistosaur, and Conchiosaur, occur, mostly in the Muschelkalk of Europe, and 

 especially at Luneville, Bayreuth, and in Upper Silesia. They differ from the Jurassic 

 Enaliosaurs in the extraordinarily large temporal, orbital, and nasal openings through the 

 ■cranium, which leave little bone. The Nothosaurus mirabilis Mii. was about seven feet 

 long. In the bone bed at the top of the Trias, in England, occur remains of two or 

 three Plesiosaurs of the Lias, as P. HawMnsii Ow. and P. costatus Ow., and of Ichthyo- 

 saurs, Sea-saurians of higher grade. 



Lacertians and other Siurians. — Most of the species of the Trias have biconcave 

 vertebra?, like the Thecodonts and Enaliosaurs (in this approximating to Fishes). A 

 species of the Permian genus Thecodontosaurus is found in the Trias at Leamington, 

 England. The turtle-headed Rhynchosnurs were among the most remarkable of Triassic 

 Saurians. 



Fig. 751, Telerpeton Elginense Mantell, a species found on the south side of the 

 Mora}' Frith, in a whitish sandstone supposed to be Devonian, but now thought by most 

 geologists to be Triassic. The animal is a Lacertian of modern type in most points, 

 according to Huxley (Q. Jour. G. Soc, xxiii); this superiority to known Permian and 

 Carboniferous Reptiles is partly the reason for making the beds Triassic. In the same 

 rock, there were thirty-four consecutive footprints of an Amphibian. The genus Belodon, 

 of Meyer, included carnivorous crocodile-like species. 



Turtles. — Tracks like Fig. 751, observed in Germany, have been referred to a Turtle, 

 the earliest representative of the tribe. The tracks form two distant parallel lines, as 

 they should for an animal having a broad shell-covered body and short legs. 



