OF TIIF WEALDEN. 
^249 
figured, occurs in the state of casts in tlie Tilgate 
grit, and is a well-marked, distinct species. I have 
named it in honour of Dr. Fitton. 
Melanopsis Several shells apparently of this 
genus are found in the beds of shale at Pounceford, 
with the cyclades ; they bear also considerable 
resemblance to melanin. 
Bulla. — Mr. Sowerby suiiposes that a small cast 
among some paludinm belongs to this genus. 
Succinea. — A cast of a small shell apparently 
of tills genus, was observed with a group of 
paludinae in the Tilgate grit ; it was not sufficiently 
defined to admit of its characters being positively 
ascertained. 
1. Cyclas menibranacea. 
2. media. 
3. Melanopsis, or Melania. 
Ci/clas. — On the shells of this genus from the 
shale of Pounceford, where entire beds are almost 
wholly composed of their broken remains, Dr. 
Fleming, the distinguished author of one of the most 
valuable works on zoology that has apjieared in this 
