340 Proceedings of the Txoyal Physical Society. 



in the Kirkland marl (5 aquatic and 5 terrestrial) ; another 

 point deserving notice is the comparatively large number of 

 species not truly aquatic, and the fact that three of these — 

 which are almost the only common ones in the material — are 

 confined to marshy ground helps to give us some idea of the 

 conditions under v^hich the deposit was formed. Another 

 point to be noted is, that though several truly aquatic species 

 have been obtained, they are all occasionally found in marshy 

 situations as well as in ponds or lochs ; moreover, the species 

 of Ostracoda referred to in the list are as frequently found in 

 marshes and pools as in more open water, if not more so. 

 Thus all the evidence we at present possess regarding the 

 physical conditions of the locality, when this deposit was 

 being formed, tends to indicate the existence of a more or 

 less extensive marsh, consisting of beds of aquatic vegetation, 

 and intervening but comparatively shallow open water, — 

 among the vegetation Succinea, Vertigo antivertigo, and 

 Carychium would find a suitable habitat; the more open 

 water would shelter Pisidium, Valvata, Planorhis, and 

 Limncea ; while the other terrestrial species might, during 

 dry seasons, readily wander within the limits of the marsh, 

 and their shells thus become intermingled with the others in 

 the gradually accumulating debris. 



With the information we at present possess to guide us, it 

 would be hazardous to attempt to make any statement as to 

 the approximate age of the deposit. Its organic remains con- 

 stitute no trustworthy guide, as they all belong to species 

 now living. But though that be the case, and though there 

 be no mass of overlying material, as is the case with the 

 Kirkland marl, to imply antiquity, yet the appearance of the 

 material seems to indicate the lapse of not a few generations 

 since the deposit was formed. 



The occurrence of Scottia hrowniana (Jones) in the Elie 

 material is of some interest, as the following brief history of 

 it will show. The species was first described by Professor T. 

 K. Jones in 1850 in the Annals and Magazine of Natural His- 

 tory as Cypris hrowniana, having been discovered in a fresh- 

 water deposit at Clacton in Essex by Mr John Brown, F.G.S., 

 of Stan way, Colchester. In 1875 Professor Prestwich recorded 



