558 Notices of Memoirs — Cretaceous Plnnts, Japan. 



Mesozoic period. They have had the good |ortune to find excellently 

 preserved material from the Cretaceous of JSIorthern Japan. 



In the present paper they describe eighteen plants from this 

 material, which is extraordinarily rich. As hitherto there has been 

 very little known from anatomical material of plants of this age, the 

 present paper is by no means final, but is in the nature of a pioneer 

 chart of the ground. 



The petrifaction of the cells of the plants is often extremely good, 

 though the fragments are not so complete as could be desired. The 

 plant-structures include stems, roots, leaves, cones, fern sporangia, 

 and even an Angiospermic flower, the first petrifaction of a flower to 

 be described. The debris lie together in the nodules in much the 

 same way that the debris lie in the Coal-balls of the Palaeozoic, 

 though they are mixed with fragments of shells. The latter are 

 largely Ammonites, and serve to determine the age of the petri- 

 factions. 



The flora as a whole represents an interesting mixed flora such as 

 has not hitherto come to light among petrifactions. 



Roughly spcu, •^..g, the flora seems to have consisted of about one- 

 third Angiosperms, slightly more than one-third Gymnosperms, and 

 the rest of ferns and lower plants. The anatomy of the early 

 Angiosperms being such a desideratum in botany, their presence in 

 the petrifactions renders them doubly interesting, and particularly 

 when they are found in so evenly balanced a mixed flora. 



All the specimens described in this paper were cut in Tokio in the 

 botanical department by the authors. 



The plants described are as follows : — 



PetrospJmria japonioa, gen. et sp. nov, A fungus which has 



numerous microsclerotia, in the periderm of one of the 



Angiosperms, Saururopsis. 

 Schizceopteris Tansleii, gen. et sp. nov. The sorus and sporangia 



of a Schizseaceous fern. 

 Fasciostelopteris mesowica, gen. et sp. nov. The stem and petiole 



of a fern with a dictyostelic anatomy. Probably allied to the 



Dicksoniacece. 

 Pern rootlets, in excellent state of preservation, showing the diarch 



stele of the leptosporangiate ferns. 

 Niponophyllum cordaitiforme, gen. et sp. nov. The leaf of what 



appears to be some plant of Cycadean affinity, the anatomy 



bearing considerable resemblance to that of Cordaites. 

 Tezonia vulgaris, gen. et sp. nov. A Gymnosperm, of which 



stems, unthickened twigs, leafy axes, are all very plentiful. 



It is the commonest plant in the material, and at the same 



time the most unique. In the anatomy of both main axis and 



foliage it is not like any known type. 

 Yezostrobus Oliverii, gen. et sp. nov. The fructification of a 



Gymnosperm, the cone bearing simple scales with seeds, one 



on each, which are like those of Cycads in some respects, but 



have a nucellus standing up entirely free from the integument 



with a well-marked epidermis between. 



