78 PALÉOZOOLOGIE ET PALÉOPHYTOLOGIE 



Reid, Eleanor-M., Two preglacial floras from Gastle Eden, Quart. 

 Journ. Geol. Soc, vol. LXXVI, pi, 2 — 1920 — pp. 104-144, pis. VII-X. 



Describes a small flora of 11 species, probably of late Pliocène, or early 

 Pleistocene âge, and a larger ilora of 114 species referred to the middle 

 Pliocène. The material from which both were derived, had been carried 

 by the Scandinavian ice in its advance, from some part of the area of the 

 North Sea, into fissures in the Magnesian limestone of the Durham Coast, 

 where it was later over-lain by Boulder Clay. The work shows that the 

 stucly of seeds can be used to détermine the stratigraphical position of de- 

 posits. A comparison with other Pliocène seed-collections led to the flora 

 being referred to the middle Pliocène. 



The habitat of the flora is discussed, and it is shown that it was probably 

 an upland flora, and that the land on which it grew must hâve stood at 

 least 500 ft. above the Pliocène seadevel. 



Espèces nouvelleSjïprobablement éteintes: Ranunciiliis edenensistrès com- 

 mune ; Spirsea erectistyla petit follicule oblong, Cralsegiis microcarpa 

 très voisin de C. spathulala Michaux, C. nodulosa (five carpels), Potenlilla 

 pliocseniea identifiée avec une espèce de Bidart près Biarritz, Bhus dunel- 

 mensis qui rappelle une espèce chinoise (R. Sinica R. et W.), Ilex oblonga 

 Genre très développé en Ghine, Melissa elegans analogue à M. parviflora de 

 l'Himalaya ; beaucoup d'autres formes — dénommées génériquement — 

 n'ont pas reçu de nom spécifique. 



E.-M. Reid. 



Reid, Eleanor-M., A comparative review of Pliocène floras, based 

 on the study of fossil seeds. Quart. Journ. Geol. Soc, vol. LXXVI, 

 part. 2 — 1920 — pp. 145-161. 



In orcler to détermine the stratigraphical position of the Gastle Eden 

 and Reuverian floras, a comparison was macle of the percentages of ail 

 exotics, and of exotics showing Chinese-North American affinities in five 

 floras — the Cromerian, Teglian, Castlc Eden, Reuverian, and Pont-de-Gail. 

 The percentages obtained were plotted ont, and were formel to lie upon a 

 smooth curve. The indication given by this curve, that the Teglian belonged 

 near the base of the Upper Pliocène, was in agreement with the conclusions 

 of paleoozoology. The curve was therefore regarded as reliable, and its 

 indications to be acceptée!. Thèse were : 1° That the Gastle Eden is Middle 

 Pliocène, and the Reuverian Lower Pliocène ; 2° That the Chinese — North 

 American flora first began to be exterminated and supplanted in West 

 Europe about the Middle Miocène, the period of the greatest uplift of the 

 trans-continental Eurasian mountain chains.; 3° That the in-coming flora, 

 which supplanted the Chinese-North American flora, first macle its appea- 

 rance in West Europe in the Middle Miocène. This flora is the pressent low- 

 land flora of west Europe. 



The study lends strong support to the suggestion of G. and E. M. Reid, 

 that the cause of extermination of thèse floras in West Europe, and their 

 survival in the Far East and North America, is the différence in trend of 

 the mountain chains in Eurasia and in the Far East and North America. 



