1871.] WHITAKER TERTIARY CLIPE-SECTIONS. 263 



form, furnished with short recurved spines (fig. 2) arranged in pairs 

 upon each seg-ment, doubtless referable to the same species. I have 

 proposed to name this form Eurypterus Brodiei, after its dis- 

 coverer*. 



Discussion. 



Mr. Dtjitcan inquired vs^hether any metamorphoses had been re- 

 cognized among the Eurypteridae, and, if so, whether the variation 

 in the thoracic plates mentioned by Mr. Woodward might be con- 

 nected with them. 



Mr. Woodward, in reply, remarked on the difficulty of distinguish- 

 ing even the sexes in Eurypteridae. The thoracic plate in the fossils 

 resembled that of Limulus ; and the variety might be connected with 

 sex. In some Slimonice from Lesmahago the only diiference to be 

 found was in the thoracic plate ; and it had been suggested that this 

 was due to dijfferenee of sex. He had already suggested that the 

 small Pterygotus and the great SIhnonia might be only the male 

 and female forms of the same species. On fragmentary remains, 

 however, it was unsafe to attempt to base species ; but he thought 

 Euryjpterus Brodiei was a weU-marked species. 



Rev. H. H. WnsrwooD inquired whether there was any evidence as 

 to Eurypterus being freshwater or marine. 



The Chairman (Prof. Morris) observed that the seeds from the pas- 

 sage-beds did not appear to him other than those of land-plants, and 

 had been previously described by Dr. Hooker as spore-cases of Lyco- 

 podiacese. 



3. On tlie Clipf-sections of the Tertiary beds West of Dieppe in 

 Normandy, and at Newhaven in Sussex. By William Whit- 

 aker, B.A. (Lond.), F.G.S., of the Geological Survey of England. 



The notes from which this paper is made were taken in the summer 

 of 1866. The two sections described are interesting as showing the 

 spread of beds that, but for them, would be thought to occur only in 

 the south-eastern part of the London Basin ; and I believe that no 

 detailed description of the French one has been published, whilst the 

 English one has been enlarged since the time of its latest descrip- 

 tion. 



1. Dieppe. 



The section near Dieppe is noticed by Passyf, in whose time 

 however, the divisions of the "Lower London Tertiaries" were not 

 understood, and various superficial deposits were included with them, 

 the whole being massed under the not very satisfactory name of 

 '' Plastic Clay." 



Mr. Prestwich has referred to this coast in his paper " On the 

 Woolwich and Beading Series " X ; and to him is owing the most im- 



* See British Association Eeports, Liverpool, 1870, p. 91. 



t Descrip. G6ol. du Dep. de la Seine Inferieure, 4to : Eouen, 1832. 



\ Quart. Journ. Geol. Soc. vol. x. p. 129, 1854, 



