Correspondence — J. E. Marr. 47 



preference to Bennettifes, although in many respects the Portland stem 

 IS identical with Bennettites Gibsoniamis. Externally, the surface is 

 covered with rhomboidal areas separated from one another by a pro- 

 jecting framework consisting of the silicified ramental tissue, which 

 thickly clothed the bases of the petioles. The peripheral portion of the 

 stem afforded thin sections from which it was possible to investio-ate 

 the anatomical structure of the leaf-bases and ramental scales. 

 Internally, the wood- and pith-tissues have been entirely replaced by 

 inorganic material. The author calls attention to the preservation 

 ot a prominent apical bud covered with narrow bud-scales and 

 capped by a mass of ramenta. No indication is found of a lateral 

 inflorescence such as characterizes Bennettites Gibsoninnus, and the 

 negative evidence suggests the occurrence of terminal reproductive 

 structures. A comparison of this fossil with recent Cycads and Ferns 

 brings out many points of close agreement with the former- and as 

 regards the structure of the ramenta, evidence is afforded of an 

 interesting survival of the closer resemblance which formerly existed 

 between Cycadean and Fern-like plants. The stem is named 

 tycadeoidea gigantea. 



-D ^V.''^''^ ^^"'^^ °^ ^^^ Keisley Limestone.— Part 11. Conclusion " 

 By F. R. C. Eeed, Esq., M.A., F.G.S. 



The author describes the Ostracoda, Brachiopoda, Mollusca, Echino- 

 dermata, and Actinozoa of the Keisley Limestone. He gives a list of 

 fossils from the Limestone, and indicates those species which occur 

 in the Limestone of Kildare, the iejotejza-Limestone of Sweden, and 

 btage F of the East Baltic provinces. As a result of his researches 

 he concludes that the fauna has a thoroughly Ordovician facies • 

 that It IS closely comparable with that of the Limestone of the Chair 

 ot Kildare, and of the Ze/jtewa-Limestone, and less closely with 

 tliat ot btage F, of the East Baltic provinces ; that its paleeontoloo-ical 

 teatures point to its stratigraphical position being at the base of the 

 Upper Bala, and that it must be regarded as the locally thickened 

 development ot a bed which is elsewhere in Great Britain very thin 

 or entirely absent, or represented by beds having different litho- 

 logical characters and a different fauna; and that the fauna has 

 certain unique characters which mark it off from all other known 

 assemblages of fossils in Great Britain. 



ooiai^:Es:F>oj^nDS2<roE. 



LIFE-ZOXES IN THE BRITISH CAEBONIFEROUS EOCKS. 

 Sir,— In the November Number of the Geological Magazine 

 the Eeport of the Committee appointed by the British Association 

 to study the Life-zones of the British Carboniferous rocks, contains 

 a list of the Committee, from which the name of Dr. R. H. Traquair 

 who has kindly undertaken to report on Carboniferous fish is 

 omitted. As our Report is likely to become known to workers 

 largely through the medium of the Magazine, I should be ^n-eatlv 

 obliged if you would kindly insert this correction. *^ 



Cambridge, December 5, 1896. JoHN E. Mark. 



