XXXVl 



Hitclim Hill, just east of the town, was then visited. The high 

 ground here is covered by a sheet of glacial drift extending right 

 into Hitchin, and of considerable interest. In one pit it was seen 

 to consist of an upper bed of clay and a lower bed of gravel and 

 sand, well stratified, and showing current-bedding here and there. 

 The gravel is composed chiefly of flints from the Chalk, and con- 

 tains a great number of fossils which appear to have come from the 

 north, many quartzites, and pebbles of white chalk. 



The celebrated Hitchin Lake Bed at "The Folly" was next 

 examined. It is a light-coloured, brown or whitish, soft calcareous 

 loamy deposit, passing down in places into a dark-grey or almost 

 black loam, and is below the brick-earth, which is the highest 

 alluvial deposit here, and above a bed of gravel of which no one 

 knows anything, not even whether it is of marine or fresh-water 

 origin. Somewhat similar examples of ancient lake beds have 

 been described in Ly ell's ' Antiquity of Man ' at Hoxne in Suffolk 

 (p. 219, 4th ed.) and at Mundesley on the coast near Cromer 

 (p. 267), and at Bedford there is a similar deposit resting on 

 Oolitic strata. The Hitchin Lake Bed has ali'eady been described 

 in our ' Transactions ' (Vol. VIII, part 4, p. xxxvii). The 

 following is a list of fossils found in it, from the ' Proceedings 

 of the Geologists' Association' (vol. xiv, p. 417). 



Mammalia : — Ursus, Cervus elaphus, Rhinoceros. 



Mollitsca: — Bytkinia tentacidata, Limnaia aurictilaria, L. peregra, 

 Planorhis carinatus, P. complanatus, P. spirorhis, Valvata cristata, 

 V. piscinalis, Veletia {Ancylus) lacustris, Anodonfa cygnma (?), 

 &plicermm corneum. 



Osteacoda: — Candona Candida, Cypris Broivniana, C. incongruens, 

 C. reptans. 



Plants : — Chara (stems and fruit). 



Cypris Broivniana, which is found abundantly in this lake bed, 

 is supposed to have become extinct. 



The following derived fossils were found on the present occasion 

 in the gravel which underlies the lake bed: — Cardinia concinna 

 (from the Lias), Pleuromya costata and P. crassa (Lower Lias), 

 Serpula tetragona ? (Cornbrash), and Gryplma bilohata (Kelloway 

 Rock). 



Many shells were found in the lake bed, but they proved to be 

 too fragile to be carried away. 



Before leaving the brickfields at "The Folly," other sections 

 were examined, and in a bed of gravel were found a Sternberg in, 

 a plant from the Coal-measures, and Avicula incequivalvis, a shell 

 from the Kelloway Bock. 



The party then walked back to Hitchin, the members of the 

 Geologists' Association having tea at the Sun Hotel before leaving 

 for London, and the members of the Hertfordshire Society returning 

 to St. Albans, etc., by an earlier train. 



