346 MR. F. W. HAEMEE ON THE LENHAM BEDS [Aug. 1 898, 



forms are so rare in the Coralline Crag that, if it were possible to 

 count specimens rather than species, the southern would outnumber 

 the northern by many hundreds, possibly by many thousands, to 

 one.^ 



'No ice reaches our shores at the present day either from Scan- 

 dinavia or Eelgium, and the winter temperature of Northern 

 Europe would have to fall considerably before such a condition could 

 arise. As to Scandinavia, the almost entire absence of boreal or 

 arctic shells from the Coralline Crag makes it probable either that the 

 Crag basin was then closed, or at least less open to the north than 

 it is at present (see also p. 350), or that the temperature of Scandi- 

 navian seas was affected, as it now is, but to a greater extent, by the 

 warm currents of the Gulf Stream ; while, as to Belgium, no similar 

 ice-borne debris occur in the Diestien beds of that country. It 

 should be noticed, moreover, that the block of porphyry in question 

 was not found in the Coralline Crag, but at its base, in abed full 

 of extraneous fossils and debris, having no distinctive character of 

 their own, forming a medley and heterogeneous group, derived 

 from various Mesozoic as well as Tertiary formations. It seems to 

 me more than probable that the block of porphyry also was derived 

 from some older formation, and that therefore it has no bearing on 

 the question of climate. A similar argument may be applied to the 

 occurrence of those mammalian remains which have been supposed 

 to indicate the character of the land-fauna of the Coralline Crag 

 period. Such fossils, however, occur at the base of the Eed Crag 

 also, and this point may be perhaps more conveniently discussed 

 when dealing with that formation. 



I entirely agree with those who think that the climate of 

 the Coralline Crag period was warmer and not colder than that 

 of Great Britain at the present day, resembling rather that of 

 the Mediterranean, or even the Azores, and I see no reason for 

 admitting the probability of great climatic changes during any part 

 of it. 



^ Prestwich, however (Quart. Journ. Geol. Soc. vol. xxvii, 1871, p. 135), 

 following Gwyn Jeffreys, who considered them to be identical with the well- 

 known Crag species, tabulated the undermentioned as northern forms of the 

 Coralline Crag : — 



Astarte undata{A.TciQT\Qa,n),(jco\AA=-A. Omalii. "I Extinct species according to 



Grlycimeris siliqua,]CheBi. = GL angusta. J S. V". Wood, 



(^A. Omalii and Gl. angusta are both found in the Miocene of Belgium, and 

 therefore can be hardly considered as boreal species.) 



Tellina calcarea, Ohem.= T'. ohliqua, 



{Tellina calcarea \latd\ is, I consider, an entirely distinct form, specially 

 chai-acterizing, moreover, one of the later horizons of the Upper Crag. It is 

 unknown in the Coralline Crag.) 



Several other species are mentioned by Prestwich, but either they are rare in 

 the Coralline Crag, or are also found in the Mediterranean or the Lusitanian 

 areas. 



Two species of foraminifera are mentioned as northern : — Lagena globosa and 

 L. ornata. The former is said, by the authors of ' The Foraminifera of the 

 Crag,' to be found in all seas, and to have existed since the Silurian period 

 (p. 177). The latter is unknown from the Coralline Crag. It is found, but 

 rarely, at St. Erth (p. 380) and in the Pliocene of Sicily. 



