592 Mr. Jurrreys’s Supplement to the ** Synopsis of 
Not the Planorbis lutescens of Lamarck, as I had supposed. 
P. Draparnaldi, p. 386. 
P. albus «. Pfeiffer, 3. 64? 
In the Honourable Lady E. Finch's collection of British 
shells, mixed with the P. albus. 
The Helix rhombea of Turton’s Conchological Dictionary 
should be referred to a variety of the Planorbis umbilicatus, and 
not this species. My error arose from having seen in the late 
Mr. Miller's cabinet, specimens of the above, which Dr. Turton 
had named “ Pl. rhombeus.” 
P. albus, p. 387. 
P. reticulatus. Risso. 
P. nitidus, p. 388. 
Abundantly in a pool on Wandsworth Common near London ; 
and more sparingly in Battersea marshes and other parts of the 
neighbourhood. The shells are frequently infested by the ova 
of a small aquatic insect. | 
Var. a. dupló minor, subtüs laté umbilicata. 
This was given to me by the Provost of Eton, who received at 
from Mr. Bean of Scarborough, and may possibly be a distinct 
species. Its form is intermediate between the Pl. nitidus and 
lineatus. | 
P. lineatus, p. 389. 
P. clausulatus. Férussac, Concordance 4c. 
ANCYLUS. 
This genus, as M. Rauq remarks, has not ceased from being 
bandied about from one family to another; and even now, its 
proper position among the Scutibranchous (for it is quite certain 
they do not belong to the Pulmonobranchous) Mollusca, is far 
from 
