564 



THE WONDERS OF GEOLOGY. Lect. V 



from the Permian deposits which have been accurately deter- 

 mined ; of these 148 are unknown in any other formation. 

 Plants, — The plants are referable to genera common in 

 the coal measures, but very rare or altogether wanting in 

 the formations above the Permian j for example, species 

 of Lepidodendron, Noggerathia, Odontopteris, &c. ; indi- 

 cating a continuation of vegetable life of the same nature 

 as that which prevailed during the carboniferous era. 



20. Invertebrata of the Permian. — The Radiaria, 

 Mollusca, and Articulata, are represented by the follow- 

 ing genera and species : — 



Fifteen species of Corals :* Crinoidea, so abundant in the Carboni- 

 ferous strata, are of excessive rarity. 



Thirty species of Brachiopodous shells, ten of which are common 

 to the Carboniferous ; the other twenty are new. 



There are six species of Productus, and eight species of Spirifer ; 

 both these genera appear for the last time. 



Of Orthis, one of the earliest forms of the family, and very cha- 

 racteristic of the Silurian, three species. 



Terebratulce with oblique and vertical septa, bearing a close 

 analogy to the Pentameri of the Devonian and Silurian : nine species. 



Species of Modiola and Axinus ; and of Avicula, eight species. 

 Posidonomya, a few species. 



Gasteropoda, fifteen species, of which twelve are new. 



Chiton, a few species have been found near Sunderland. 



Cephalopoda scarcely a vestige : only doubtful specimens of Nauti- 

 lus, or Cyrtoceras. 



Of the Trilobites, which in the Carboniferous system are reduced to 

 some few small species, there are no traces whatever. But there is a 

 large and peculiar species of Limulus (L. oculatus) ; and this genus 

 which first appears in the coal system has continued to the present 

 time.f 



21. Fishes of the Permian. — The fishes of this sys- 

 tem comprise between forty and fifty species, belonging to 



* The Retepora fiustracea is a very abundant and characteristic 

 coral of the Sunderland magnesian limestone. 



f This notice is principally taken from the Tabular list of the 

 animal remains of the Permian System, in Sir 1\. Murchison's " Geology 

 of Russia," vol. i. p. 221. 



