of British Mollusca. 341 
274. Planorbis umbilicatus , Miill., = P. complanatus, Jeffr. 
(non Linn.). 
P . complanatus , L., is generally now regarded as P. nitidus , 
and not the present species, which, however, has been called 
complanata by Stein, Dupuy, Moquin-Tandon, Locard, 
Bourguignat, &c. 
275. Planorbis vortex (Linn.). 
276. Planorbis spirorbis (Linn.). 
\_Planorbis dilatatus , Gould. 
Planorbis dilatatus , Gfould, Invert. Mass. (1841), p. 210, fig*. 140 ; ibid, 
edit. Binney (1870), p. 498, fig. 748 ; Rogers, Journ. Conch, vol. i. 
(1874), p. 81. 
An accidentally introduced species, which appears to have 
established itself in the neighbourhood of Manchester in the 
Bolton Canal at Pendleton and Galton ( Thos . Rogers ) .] 
277. Planorbis glaber 7 Jeffreys. 
278. Planorbis albus 7 Muller. 
279. Planorbis nautileus (Linn.). 
280. Planorbis complanatus (Linn.) =P. nitidus 7 Gray = II. 
fontanus , Light foot. 
Genus 5. Segmentina, Fleming. 
281. Segmentina nitida (Mull.) = Planorbis lineatus (Walker), 
Jeffr. 
Judged out of his own work, by comparing what is said of 
Miiller’s Planorbis nitidus in vol. i. p. 80, and vol. v. p. 172, 
Jeffreys shows that that species is the present and not the last 
to which he referred it. 
Fam. 11. Physidse. 
Genus 1. Piiysa, Lamarck. 
282. Physa fontinalis (Linn.). 
Subgenus Aplexa, Fleming. 
283. Physa hypnorum (Linn.). 
[To be continued.] 
Ann. & Mag . N. Ilist . Ser. 6. Vol. vi. 
24 
