OF PLANORBIS AT STEINHEIM. 89 



found in other formations, and I cannot see why it should be necessarily considered as 

 entirely composed of transported materials, as described by Hilgendorf 



PI. dlscoideus, PI. trocUformis, and one well-preserved specimen of PI. oxystomus 

 were obtained. • 



Formation " 1. " (Uncertain.) 



The absence of the upper or clayey formations from " m" upwards, in the Old 

 Pit, had attracted my attention from the first. 



In order to ascertain whether this had been due to denudation, I ordered a hole 

 to be dug on the top of the hill at some distance from the Old Pit, and a little 

 to the north of a line connecting the Old Pit and the East Pit. This was sunk 

 about eight feet ; the first two feet or so through a bed of rubble, containing 

 large specimens of Lyrana^a ; the remaining five feet, through a bed corresponding 

 more to Formation I of the Old Pit, than to any other. PI. trochiformis of the same 

 varieties as those figured on plate 2, lines r, s, were very abundant, but distinguished 

 by the almost invariable absence of the carination on the lower side. 



PI. costatus and minutus were also quite abundant, especially the latter ; in both 

 also the specimens were large, and the ribs in the latter very coarse and prominent, as in 

 the variety 'major Hilgend. Var. Kraussii was also found, but of rare occurrence. 



The bed could not be said to be continuous with I in the Old Pit, although in all 

 probability it was synchronous, and bed x was entirely absent, its place being occupied by 

 the rul^ble, which occurs frequently just under the surface soil on the hill, and appears 

 to be composed of drift from the Cloister-ridge rocks. 



This result was interesting, in so far as it confirmed the conclusions attained 

 elsewhere, that the beds often differ so essentially, although but a short distance 

 removed from each other, that it is not possible to determine whether they are 

 exactly synchronous. One fact is worthy of special remark. The rubble had also 

 occurred at the very highest point known, the top of the Cloister Pit, Section 1, but the 

 oxystomus layers were absent, and the rubble on the north side of the hill rested directly 

 on the trochiformis beds, which agree in their fossils with formation I of the Old Pit 

 more than with the higher beds x ; which, however, have similar fossils. 



New Pit, Section 8, South side. 



This section was made on the south side of the New Pit, where the formation diflFered 

 somewhat from those on the east side, as shown in Section 7. It would have been 

 idle to repeat the figures of the usual PL discoideus and trochiformis shells of the 

 Old Pit, and other species which have been already so fully given. These occurred 

 abundantly in some of the strata, and more rarely in others, until in Formation m, they 

 gave way to the usual fauna of the oxystomus zone. I have accordingly only figured 

 those forms which were not previously found at what have been considered as 

 corresponding levels in the Old Pit, or which seemed to require special consideration. 



