Mollusca of Great Britain. 359 



3. Revoluta. 

 Animal — 



Testa subventricosa, subattenuata, albida, glabra. Anfrac- 

 tus 5, sensim minores, sutur4 levi. Apertura suborbi- 

 cularis, extrinsecalis, edentula, nee uiarginata : peri- 

 stomio postic^ subreflexo. Umbilicus dilatatus, com- 

 pressus, foramine cylindrico. 



Long. 0.1. — Diam. 0.05. 



Among the rejectamenta of a small stream at Marino 

 near Swansea, where only one specimen has as yet occurred 

 to me. The umbilicus is much more flattened and open than 

 in the rest of the genus. 



4. Cylindrica. 

 Animal 



Testa attenuata, pellucida, striis argutis obliquis, pallid^ 



fusca. Anfractus 5, suturd profundi. Apertura ovata, 



extiis parilm marginata, edentula. Umbilicus angus- 



tatus. 



Long. 0.075.— Diam. 0.03. 



Pupa muscorum (a). Drop. Hist, des Moll. p. 59- 

 Vertigo cylindrica. Fir. Tab. des Moll. p. 64. 



Of this very beautiful little shell I found a single live 

 specimen on the imder side of a loose stone on Durdham 

 Downs near Bristol ; but I regret that J did not at the time 

 examine the animal. 



5. Vulgaris. 



Animal nigro-griseum, nitidulum. Tentacula nudo oculo 

 nequaquam discernenda, armato punctiformia viden- 

 tur. 

 VOL. XVI. 3 a Testa 



