139 



species in the London Clay; yet I must draw the attention to 

 the resemblance it has to the Portunites incerta Bell ^) ; accor- 

 ding to Bell's description the two species cannot be identical, 

 but in the first place the Portunites incerta (judging from Bell's 

 figures), seems to vary not a little, and secondly Bell's descrip- 

 tion is somewhat brief. In spite of all my exertions I have 

 unfortunately not succeeded in procuring any specimen of this 

 species for purposes of comparison with the Greenland one. 



If a closer comparison could be drawn between the Cyrena- 

 bed and the West-European Tertiary, it would presumably be 

 between the Sables de Cuise or the Bagshot beds, which deposits 

 are said to be partly contemporaneous. This supposition is 

 especially supported by the frequent occurrence of Cyrena 

 Gravesii Desh. at Кар Dalton. This species is also very 

 common at Cuise-la-Motte, where a like mixed fauna is 

 found as in the Cyrena-bed at Кар Dalton. Of other species 

 which I have found in the latter bed, I have already mentioned 

 Cryptodon cfr. unicarinatus Nyst. Like this species Mytilus 

 affinis J. Sow. also seems to indicate a higher horizon, while 

 the opposite is the case with Ästarte cfr. tenera Morris ; but 

 the occurrence of these species is not quite certain, and it is 

 not impossible that some species, in such a distant locality, 

 may have a somewhat different vertical extension than usual. 



As will be seen by the above description, the East-Green- 

 land Tertiary seems to be closely related to the West-European. 

 The resemblance is so great that we may certainly suppose, that at 

 the time when the above mentioned formations were deposited, 

 there must have been a connection between the two oceans. 

 However this connection presumably need not exclude the 

 possibility of a «land-bridge» between Western-Europe and 



Bell: A monograph of the fossil malacostracous Crustacea of Great 

 Britain. Part I. Crustacea of the London clay. London 1857. p. 21; 

 pi. 3, figs. 1—5. — The Palaeontogr. Society. 



