372 PALEOZOIC TIME. 



Characteristic Species. 



1. Radiates. — (&.) Polyps. — Cyathophylloid Corals, (b.) Acalephs. — Corals of 

 the genus Stenqpora. (c.) Echinoderms. — Crinoids near Cyathocrinus ; Eehinoids of 

 the genus Eocidaris, near the Paleozoic Archceocidaris. 



2. Mollusks. — (a.) Bryozoans. — Eenestella retiformis Vera., found in the Per- 

 mian of Russia, England, and Germany, besides a dozen other related species. 



{b.) Brachiopods. — Spirifer alatus Schloth., from England, Lower Zechstein in Sax- 

 ony, — some specimens 2| in. broad; Spiriferina cristata Dav;, from the Zechstein, 

 Germany; Productus horridus Sow., from England and Germany, characteristic par- 

 ticularly of the Lower Zechstein, and occurring also in the Kupferschiefer; Strophahsia 

 excavata Gein , England, Germany; the species of the genera Productus and Stropha- 

 hsia are exceedingly abundant in individuals ; Camarophoria Schlotheimi Von Buch, 

 from Russia, Germany, and England; the genus is related to Terebratula and Pen- 

 tamerus, and is peculiar to the Carboniferous and Permian; Camarophoria superstes, 

 Russia. 



(c.) LameUibranchs. — Pseudomonotis speluncarin Beyr., England, Russia, and Ger- 

 many in the Lower Zechstein; CUdophorus Pallasi Gein., Russia and Germany; Mya- 

 lina squamosa Sedg., Russia, England; Avicula KazanensisVem., Russia; Bdkewellia 

 antiqua King, England, Russia, Germany; Schizodus dubius M., a very common species 

 in England, German}-, and Russia; Schizodus Schlotheimii Gein., S. obscurus Sow., and 

 S. truncatus King. The genus Schizodus is of the same family with Trigonia, a charac- 

 teristic genus in the Reptilian age: it commenced in the Devonian. 



(d. ) Gasteropoda are rare fossils in the Permian. There arc a few species of Murchi- 

 sonia and Straparollus, Paleozoic genera, besides some others. 



(e. ) Pteropods of the genera Theca and Conularia. 



{f.) Cephalopods existed, and among them two or three species of Orthoceras. 



3. Articulates. — No Trilobites are known. Ostracoids are common. Under 

 Tetradecapods, occurs here the Amphipod, Prosoponiscus problematicus, from the Per- 

 mian of Durham, England, first described by Schlotheim, but recently explained by 

 Bates. Decapods of the order of Macrourans appear to have commenced in the Coal 

 formation. But the first of the Brachyurans is announced from the Permian by Von 

 Schauroth, who names it Hemitrochiscus paradoxus. It is an eighth of an inch long. 

 Geinitz regards it as related to the Pinnotheres family. 



4. Vertebrates. — («.) Fishes. — Fig 696, Palceoniscus Freieslebeni Agassiz, one- 

 third the natural size; common in the Kupferschiefer, and also found in the Coal- 

 measures in England, at Ardwick. Over forty species of fishes have been described. 

 The more characteristic genera are Palceoniscus, Platysomus, Acrolepis, Pygopterus, and 

 Xenacanthus, but they are also all Carboniferous. Besides the above, the species include 

 Palceoniscus elegans Sedgw., P. comptus Ag., Platysomus macrurus Ag., PL gibbosus BI., 

 Acroleins Sedgwickii Ag., Pygopterus mandibulars Ag., Ccelacanthus granulatus Ag., etc. 

 lanassa bituminosa Miinst. and Wodniha striatida Miinst. are species of Cestraciont 

 sharks from the Kupferschiefer. Menaspis armata Ewald, from the Kupferschiefer, 

 has been regarded as a Cephalaspid related to Pteraspis, but also as the head or tail 

 shield of a Crustacean. 



(b.) Rej>tiles. — A number of species have been described, belonging to the tribes of 

 Labyrinthodonts and Thecodonts. Fig. 697, Proterosaurus Speneri Me3 r er, regarded as 

 a Thecodont. It was 3h feet long, and is from the copper-slate (Kupferschiefer) of Ger- 

 many and Saxony. Two species of the same genus have been found in the marl-slate 

 of Durham, England, along with others of Labyrinthodonts. Dasyceps Bucklandi Hux- 

 ley is a Labyrinthodont, from Kenihvorth, England, the only specimen a cranium 10 

 inches long and 9 J broad. 



These Permian Reptiles had biconcave vertebrce, like the inferior swimming reptiles, 

 but the socket-teeth of the Crocodiles. The teeth were flattened, and crenulate at the 



