THE FOSSIL OSMUNDACE^E. 



465 



The following table contains a list in chronological order of the species we have 

 described, with a synopsis of their most important anatomical features. It brings into 

 prominence the fact that the medullation of the stele and the subsequent breaking up 

 of the xylem ring takes place pari passu with the advance from the older to the 

 younger strata. 



Geological Distribution of the Fossil Osmundace.e — with their most important 



Anatomical Features. 







Localities of Species 







Potosp 



Name. 



Horizon. 



described in this 

 Memoir. 



Pith. 



Xylem. 



Layer. 



Osmundites Schemnitz 



Lower Pliocene, 



Ulia, near Schemnitz, 



Parenchyma- 



Separate strands. 



\ 



ensis, Pettko, sp. 



or Upper Mio- 

 cene. 



Hungary. 



tous. 







Osmundites Doivkeri, 



Lower Eocene. 



Heme Bay, Isle of 



Do. 



Do. 



1 



Carruthers. 





Wight. 









Osmundites Skidegat- 



Lower Creta- 



Alliford Bay, Skide- 



Do. 



Separate strands, 



Present. 



ensis, Penhallow. 



ceous. 



gate Inlet, Queen 

 Charlotte Islands, off 

 British Columbia. 





with internal 

 phloem. 





Osmundites Kolbei, 



Uitenhage Se- 



Herbertsdale, Cape 



Parenchyma, 



Separate strands. 



1 



Seward. 



ries, Wealden 

 (Upper Jur- 

 assic). 



Colony. 



mixed with 

 tracheae. 







Osmundites Gibbiana, 



Jurassic. 



Near Gore, Otago Dis- 



1 



Do. 



? 



K. and G.-V. 





trict, New Zealand. 









Osmundites Dunlopi, 



Do. 



Do. 



1, 



Continuous ring 



1 



K. and G.-V. 









of normal tra- 

 cheae. 





Zalessky a gracilis, Eich- 



Upper Permian. 



Kluczersky, District of 



Absent. 



Solid. Central 



Absent. 



wald, sp. 





Bjelebei, Government 

 of Orenburg, Russia. 





elements short 

 and thin-walled. 





Zalesskya diploxylon, 



Do. 



Believed to come from 



Do. 



Do. 



Do. 



K. and G.-V. 





Kluczersky, District 

 of Bjelebei, Govern- 

 ment of Orenburg, 

 Russia. 









Thamnopteris Schlech- 



Do. 



Near Bjelebei, Govern- 



Do. 



Do. 



Do. 



tendali, Eich. sp. 





ment of Orenburg, 

 Russia. 









Anomorrhoea Fischeri, 



Do. 



Copper Mines of Klou- 



1 



i 



? 



Eich. sp. 





tschewsk, District of 

 Bjelebei, Government 

 of Orenburg, Russia. 









Ba thypteris rhomboidea, 



Do. 



Mine, Kloutschewsk, 



<l 



1 



? 



Kutorga, sp. 





District of Bjelebei, 

 Government of Oren- 

 burg, Russia. 









