256 Maw — Tufa Deposits in Flintshire. 



period, with tlie gravels of which. (?) they are partly occupied. On 

 the other hand, the great deposits of soft Tufa near Caerwys could 

 not have resisted the marine submergence, and their deposition 

 subsequently to the drift is also evident from their resting on 

 its eroded surface. 



The subterranean dissolution of the limestone commenced, there- 

 fore, some time before the submergence of several hundred feet that 

 filled the Cefn caves with gravel, and continued afterwards suffi- 

 ciently long to provide materials for the great masses of Tufa, near 

 Caerwys. 



It is worthy of observation that no evidence is to be found that 

 the calcareous deposition is still proceeding, and that with an ap- 

 parently similar condition of surface, the causes tending to the 

 formation of a Tufa have entirely ceased. 



nsroTiciES OIF uvEZE^vcoiies. 



, I. — On the Bhinoceros leptorhinus of Owen. 



By W. BoTD Dawkins, M.A., F.G.S. 

 [Abstract of a Paper read before the Eoyal Society, April 26tli, 1866.] 



THE fossil remains of the genus Eliinoceros, found in Pleistocene 

 deposits in Great Britain, indicate four well-defined sj)ecies. 

 Of these the B. tichorhinus, or the common fossil species, ranged 

 throughout France, Germany, and Northern Eussia, and like its 

 congener, the Mammoth, was defended from the intense winter cold 

 by a thick clothing of hair and wool. Its southern limit in the 

 Europseo- Asiatic Continent was a line passing through the Pyrenees, 

 the Alps, the northern shore of the Caspian, and the Altai moun- 

 tains. It has not yet been proved to have' existed in Europe anterior 

 to the deposit of the Boulder-clay. The second species, the B. 

 megarldnus^ of M. de Chi'istol, characterized by its slender limbs, 

 and the absence of the " cloison," has been determined by the 

 author among remains from the brick-earths occupying the lower 

 pai-t of the Thames Valley, and from the Pre-glacial Forest-bed 

 of Cromer. The species ranged from the Norfolk shore, south- 

 wards, through Central France, into Italy. In France and Italy it 

 characterizes the Pliocene deposits, being found in the former 

 country in association with Mastodon brevirostris, and Halitlierium 

 Serresii, in the latter with M. Arvernensis. From its southern range 

 we may infer that the megarhine species was fitted to inhabit the 

 warm and temperate zones of Europe, just as the tichorhine was 

 peculiarly fitted for the endm-ance of an Arctic winter. 



The third species is the B. etruscus of Dr. Falconer, confined to 



' For Paper on the Rhinoceros megarhiniis see Dawkins, Nat. Hist. Eevie-w, 1865. 

 p. 399. 



