GASTEROPODA. LIMNADZ. 115 
Planorbis marginatus, Drap. Hist. des Moll. 45. pl. 2. figs. 
PP 123-15. 
Planorbis complanatus, Flem. Edinb. Encycl. vii. 69. 
Animal olivaceo-nigrum. Tentacula lateraliter et ad basin 
rufa aut rufo-citrma. Oculi atri. 
Habitat in stagnis et paludibus vulgatissima. 
Shell horny, fuscous, slightly pellucid, distinctly flatter on 
the left side ; the whorls transversely striated, the left side of 
the dorsal aspect of the whorls carinated. Diameter six-eighths 
of an inch; sometimes greater. 
Animal olive-black. Tentacula with their sides and their 
base rufous, or reddish orange-coloured. Eyes black. 
This very common species is found in all parts of Britain, 
inhabiting ditches and ponds. 
5. PLANORBIS SHEPPARDI. 
P. testa nitida, diaphana, ad sinistram planiuscula ; anfractibus 
transversim striolatis, ad sinistram dorsi carinatis. 
Helix complanata, Linn. Syst. Nat. 1242; Fn. Sv. 2177. 
Habitat in fluvio Ore dicto, in provincia Soffolciensi. 
Shell glossy, diaphanous, its left side nearly flat. Whorls 
very finely striolated transversely ; the left side of their dorsal 
aspect carinated. 
I am indebted to the Rev. Revett Sheppard for this elegant 
species of P/anorbis, which he found in the river Ore, in Suf- 
folk, and communicated to me as the true Helix complanata of 
Linné ; and it agrees so well with the character given in Fauna 
Suecica, as to leave no doubt on my mind. 
The longitudinal diameter of the specimens received from 
Mr. Sheppard does not exceed a quarter of an inch; but Mr. 
Sheppard informs me, that he has larger ones in his own cabi- 
net, from near Blaxhall, in the same county. 
6. PLANORBIS IMBRICATUS. 
P. testa ad dextram planiuscula ; anfractuum epidermide trans- 
versim eleyata, carina obsoleta, tuberculata. 
Planorbis imbricatus, Mill. Verm. Hist. 165; Drap. Hist. des 
Moll. 44, pl. 1. figs. 49, 50, 51? 
