OF PLANORBIS AT STEINHEIM. 95 



Formation "xl," East Pit. 

 This formation occurred in a pocket of limited extent. 



Formation " m," East Pit. 



The lower part of this formation was divided by a layer of broken pieces of limestone. 

 Both parts consisted of clay. Specimens of PI. trochiformis, PL "■''Z'^/""^ var. rever- 

 tens, and PI. oxystomus, PL crescens, PL tenuis, PL minutus and PL costatus var. major 

 were also found. The upper part contained the same forms with the exception of 

 PL costatus and PL trochiformis in one ii])ot, while in anotlier, almost adjoining, these 

 were also found. 



Formation -'n," East Pit. 



This consisted also of two parts. The lower of an argillaceous shell-sand, and the 

 upper of an exceedingly fine sand filled in the border with nodules of the same material, 

 but of lithographic fineness, and very soft. The lower portion alone contained fossils. 



PL trochiformis, PL crescens, PL '"'■fe'Z"'^ var. reverteris, and PL costatus var. major 

 occurred, but none very abundantly. 



Formation "o," East Pit. 



This consisted of clay more or less permeated by reticulated veinings of limestone, 

 arising from percolation from above, giving the whole a loose tufaceous aspect, reminding 

 one of the limestone on the surface of the hill. Only a few specimens were found. PL 

 oxystomus var. revertens, PL oxystomus, PL crescens, and PL costatus var. major. 



Formation "x3," East Pit. 



This appeared to be similar in character to what was found in the Old Pit, but con- 

 tained PL oxystomus in considerable abundance. 



East Pit, Section 2. 



It is not necessary to describe in detail the formations shown in this section. It 

 is taken from an excavation in the centre of the Pit. Three such excavations were 

 examined, and an attempt made to sink this one deeper, which was unsuccessful on 

 account of the influx of water. It is evident, however, here, that the strata are apt 

 to become thicker, as we progress outwards from the hill. The fossils were about the same 

 as in the corresponding formations of Section 3. 



Cloister Pit, Section 1. 



This pit, which had become filled with debris, was reopened to a depth sufficient to 

 uncover the beds containing abundance of the PL discoideus and trochformis. None of 

 these formations compare very closely with those of the other pits, and it is to be regret- 

 ted that I did not continue the excavations to the base. 



