36 Notices of Memoirs — A. C. Seward* s Jurassic Flora. 



outer crystalline layer. In some cases, however, the entire mass- 

 has undergone a complete subsequent change into a crystalline- 

 structure. 



5. Peai'l-spar (crystals of the combined carbonates) is seldom met 

 with. I failed to find any. 



6. In the Fulwell beds there are very few fossils, and where met 

 with, as at Mai'sden, concretionary action is seldom traceable near them. 



7. The specimens at Fulwell which arouse the most interest 

 are coralloid masses (' honeycomb ' of the quarrymen). They are 

 confined, so far as I could discover, to a stratum, about 1^ foot thick, 

 above the marl bed, and lie in close juxtaposition to each other, 

 which accounts for their peculiar external shape. 



In conclusion I would point out the close resemblance which exists- 

 between the ' lines ' and ' planes ' in these concretionary beds, and 

 the ' lines ' which shoot across congealing water. In some respects- 

 the architecture of the magnesian beds compares with the ice- 

 decorations seen on our window-panes in frosty weather. 



V. — The Jurassic Flora of East Yorkshire.^ By A. C. 

 Seward, F.R.S. 



THE plant-beds exposed in the cliff sections of the Yorkshire 

 coast have afforded unusually rich data towards a restoration 

 of the characteristics and composition of a certain facies of Mesozoic 

 vegetation. Eich collections of plants from Gristhorpe Bay and 

 other well-known localities are found in the British Museum (Natural 

 History), also in the Museums of Scarborough, Whitby, Cambridge, 

 Oxford, Manchester, York, Newcastle, Leeds, and elsewhere. Th& 

 Natural History Museum, Paris, contains several important York- 

 shire plants, some of which have been described by Brongniart and 

 Saporta. The following species have been recognized from the East 

 Yorkshire area : — 



MarcJiantites erectiis (Leek., ex Bean MS.) ; Equisetites columnaris,. 

 Brongn. ; Equisetites Beani (Bunb.) ; Lycopodites falcatus, L. & H. - 

 Cladophlebis denticidata (Brongn.) ; C. haiburnensis (L. & H.) ; C lohi- 

 folia (Phill.) : Coniopteris arguta (L. & H.) ; C. hjmenophylloides 

 (Brongn.) ; G. quinqueloha (Phill.) ; Dictyophi/llum rugosum, L. & H. ; 

 Klulcia exilis (Phill.) ; Laccopteris polypodioides (Brongn.) ; L. Wood- 

 wardi (Leek.) ; Matonidium Goepperti (Ett.) ; Pacliypteris lanceolata, 

 Brongn. ; Biiffordia Goepperti (Dunk.) ; Sagenopteris PhilUpsi 

 (Brongn.) ; Sphenopteris Mtirrayana (Brongn.) ; S. Williamsoni, 

 Brongn. ; Tceniopteris major, L. & H. ; T. vittata, Brongn. ; Todites- 

 Williamsoni (Brongn.); Anomozamites Nilssoni (Phill.) ; Araucarites 

 Phillipsi, Carr ; Baiera gracilis, Jimib. ; B. Lindleyana (Schimp.) ;. 

 £. Phillipsi, Nath. ; Beania gracilis, Carr ; Brachypliyllum mammillare, 

 Brongn. ; Cheirolepis setosus (Phill.) ; Cryptomerites divaricatus, 

 Bunb. ; Ctenis falcata, L. & H. ; Czehanoioslcia Murrayana (L. & H.) ; 

 Dioonites Nathorsti, sp. nov. ; Ginkgo digitata (Brongn.) ; G. ichithi- 

 ensis, Nath. ; Nageiopsis anglica, sp. nov. ; Nilssonia compta (Phill.) ; 



1 Eead before the British Association, Section C (Geology), Bradford, Sept., 1900.- 



