JTJEASSIC PLANTS FEOM KAGA, HIDA, AND ECHIZEN. 13 



Shimamura. Okamigö has 8 species in common with Shimamuni and 



3 with Ozô and Hakogase. Ushimaru up to this time has given only 



4 well determinable species, of which 2 are also found in Ozö, so it is 

 probably referable to the same geological horizon as the latter. 



Thus we see that the floras of the seven localities of Kaga, Hida 

 and Echizen are so closely related to one another, that they may be 

 considered as forming one great flora that has flourished during the 

 Jurassic period in Central Japan. In giving a general survey of 

 this flora, we have at least five orders of plants to distinguish, viz., 



1. Filiees. Represented by at least 8 genera and 19 species, 

 14 of which are Polypodiaceae. All of them except one belong to the 

 well known Jurassic genera Dicksonia, Thyrsopteris, Asplenium, and 

 Adiantites, the first with 4 species and the rest each with 3 species. 

 The most interesting species of the first genus is Dicksonia nephroearpa, 

 first found in England, and afterwards in Siberia. The species has 

 been founded on a fertile frond of a fern which strongly resembles that 

 of the recent Dicksonia culcita UHerit. To this are to be added three 

 other Siberian forms, D. acutiloba, D. gracilis and D. cfr. Glchniana. 

 Thyrsopteris is at least represented by two already known species, Tli. 

 Murraijana and Th. prisca ; the former originally described from 

 Yorkshire, the latter from Kamenka, but both found in Siberia. Very 

 interesting is the discovery of Aspleniums which all belong to 

 forms already described. Foremost of these is A. Whitbiense, which 

 is the fossil of the Jurassic period. No less important are the two 

 others, namely, A, argutulum and A. distants, both of which are 

 European as well as Asiatic. Adiantites are all new; one of them — A. 

 Heerianus — showing a fructification like that of A . capilliis-veneris L. 

 of recent times. The most interesting, however, of all the Polypodia- 

 ceae is Oni/chiopsis elongata, a new form of fern with elongated sori 

 strongly suggestive of the recent genera of Onycliiuin and Crypto- 



