198 DR. C. T. TRECILMAXX OX IXTER GLACIAL [vol, lxXV, 



The Castle-Eden iiora also contains species known so far only 

 from the Teglian and Reuverian, in some cases from the Eeuverian 

 alone. Unfortunately, some of these are Labiates the species of 

 which we were unable to determine, when examining the material 

 from those deposits, and the discovery of them at Castle Eden does 

 not throw light on the present-day affinities of the deposit. 



Such evidence of affinity, then, as is at present forthcoming 

 tends to associate the Castle-Eden tlora with the Teglian rather 

 than with the Cromerian. In the Cromerian almost the last trace 

 of the Chinese element had been exterminated by the ever-increasing 

 cold; and, unless it be in the small ITrtica, which occurs in the 

 Cromerian, Teglian, and Reuverian, and was doubtfully assigned in 

 the Eeuverian memoir to 77. dioica, there is no trace in the Cro- 

 merian of any of the peculiar Eeuverian species. 



Passing on to compare the assemblage of Castle-Eden plants 

 with those from the other three Pliocene deposits, we find at once a 

 great distinction. These, although differing in their component 

 ■elements, yet show one marked characteristic in common : the great 

 abundance, both in number of species and of individuals, of water- 

 plants and waterside plants. In the Castle-Eden assemblage the 

 case is quite different : instead of Trapa, Xajas, pond- weeds, 

 ■water-lilies, etc. occurring in the greatest profusion, at Castle 

 Eden Trapa does not occur, there are a few nuts of pond- weed, one 

 minute fragment of JVajas mi nor (the only representative of a 

 genus which in the other deposits occurs abundantly), and no 

 water-lilies at all. Instead of these, we have as the commonest 

 species Potent ilia argentea, essentially a plant of dry banks and 

 gravelly places. 



This distinction in the floras seems to point to a difference of 

 habitat, not of climate ; or more correctly, only to such difference 

 •of climate as would correspond with a difference of habitat. 



In the case of the Eeuverian, Teglian, and Cromerian deposits 

 there can be little doubt that they contain the debris of great rivers, 

 on the banks and in the quiet backwaters of which grew an 

 abundance of water-plants, and the courses of which lay through 

 a varied country, largely forest-land. The Castle-Eden deposit 

 points to other conditions : here the absence of plants inhabiting 

 slow mud-bottomed streams, or pools, shows that the stream which 

 deposited the debris probably ran clear over a rocky or pebbly 

 bed. The presence of rock-loving and bank-loving plants, such as 

 Co/oneaster, jPotent/'Ita arf/entea, and Oxatis corniculata, confirms 

 this interpretation. Probably the stream was an upland one flow- 

 ing through a rocky valley with pastures, having somewhat the 

 character of an Alpine valley. 



It follows that, in comparing the climates of Castle Eden and 

 Tegelen as shown by their fossil floras, we are comparing the 

 climate of an upland valley in the North of England with that of 

 the lowlands of Limburg. These would not, contemporaneously, 

 have the same character in the past any more than thej' have 

 to-day. That consideration necessitates a slight correction as to 



