232 Notices of Memoirs — C. Reid — PalcBolithic Deposits, Hitchin. 



Velletia lacustris, Linn. ; Vahata piscinnlis, Miiller : Valvata cristata, 

 Miiller; Bythinia Leachii, Shepp. ; Bythinia tentacuJata, Linn.; Fisl- 

 dium pusillum, Gniel. ; SplicBrium corneum, Linn. ; Anodonta. 



Floweking Plants. — Bnnuncuhis aqiiatilis, Linn. ; Ranunculus 

 sceleratus, Linn. ; Ranunculus repens, Linn. ; Ilontia fontana, Linn. ; 

 Primus spinosa, Linn. ; Poterimn officinale, Hook, f. ; Pyrus torminalis ? 

 Ehrh. (identical with seeds found at Hoxne) ; Mippuris vulgaris, 

 Linn. ; Myriophyllum ; Cornus sanguinea, Linn. ; Sambucus nigra, 

 Linn. ; Eupatorium cannabinum, Linn. ; Fraxinus excelsior, Linn. ; 

 Menyanthes trifoUata, Linn. ; Lycopus Europaius. Linn. : Ajuga reptans, 

 Linn. ; Alnns glutinosa, Linn. ; Quercus robur, Linn. ; Ceratophyllum, 

 • demersum, Linn. ; Sparganium ; Potamogeton crispus, Linn. ; Fota- 

 mogeton, sp. ; Potamogeton, sp. ; Naias marina, Linn. ; Scirpus 

 lacustris, Linn. ; Scirpus, sp. ; Carex. 



Mosses. — Antitrichia curtipendrda, Brid. ; HomalotJiecium sericeum, 

 Bry. Europ. ; Hyocomium hrevirostrel Bry. Europ. ; Isothecium? ; 

 Neckera complanata, Bry. Europ. ; Stereodon cupressiformis, Brid. ; 

 Zygodon ? 



CHARACiE. — Several species indet. 



Sucli trees as the oak, ash, sloe, cornel, elder, and alder point 

 unmistakably to a temperate climate, and the fauna and flora as 

 a whole suggest climatic conditions not differing greatly from those 

 we now enjoj'. Mr. Mitten writes of the mosses, that " all these 

 are inhabitants of a sylvan temperate region .... and none 

 point to a different environment from that now existing ; they are 

 not Arctic." The occurrence of Naias marina, now only found in 

 Britain in two of the Norfolk Broads, is singular, although the plant 

 was evidently more common in former times than at the present 

 day. It has now been discovered in the Pre-Glacial deposits of 

 Norfolk and Suffolk, beneath Palgeolithic remains at Hitchin, and 

 in a submerged land-surface of Neolithic date at Barry Docks, in 

 South Wales. 



The resemblance of the Hitchin Palgeolithic brickearth to the 

 Palfeolithic brickearth of Hoxne, and the similarity of the old alluvia 

 beneath, both in fossil contents and in the physical changes they 

 suggest, are so striking that one is compelled to con-elate them bed 

 by bed. If, however, this correlation be correct, it is evident that 

 the intermediate deposit full of leaves of Arctic willows, so con- 

 spicuous over part of the area at Hoxne, is missing at Hitchin. At 

 each locality the same story is told. Some time after the passing 

 away of the ice the land stood higher than now, so that the streams 

 had a greater fall and valley's were cut to a somewhat greater depth. 

 Then the land sank and the valleys became silted up with layer after 

 layer of alluvium, to a depth of at least 30 feet, the climate remaining 

 temperate. The next stage, when an Arctic flora reappeared, is 

 only represented at Hoxne. The third stage in the infilling of the 

 valleys is shown in the curious unstratified decalcified brickearth 

 with scattered stones and Palseolithic implements, identical in 

 character at Hitchin, Hoxne, Fisherton, and other localities, which 

 irresistibly suggest a mingling of wind-transported material and 

 raiuwash. 



