HYGROMIA REVELATA. onl 
The description of H. occidentalis given by Dr. L. Pfeiffer and based on 
specimens in the Cuming collection would seem to refer to H. ponentina as 
described by Morelet or may be allied to or identical with Helix montivaga 
Westl., to which the H. lisbonensis Pfr. probably also conforms. 
A study of the original figures and description of Helia ponentina Morelet 
leads, however, to the view that possibly two species are confused together, 
the one to which the figures and the greater part of the description applies 
being evidently not the British HZ. revelata, but a globose spirally-banded 
shell with a thick, white and reflected lip, closely related to H. montivaga, 
a species described by Dr. Westerlund from specimens he found intermixed 
with a number of shells sent to him as H. ponentina by M. Morelet. 
I therefore separate Helix ponentina Morelet, H. occidentalis Recluz, 
and HH. lisbonensis Pfr. from Hygromia revelata, but tentatively admit 
H. occidentalis Moq., pending confirmation or otherwise of the published 
anatomical differences. 
In 1827 Capt. Thomas Brown in 
his Illustrations of British Conch- 
ology described a Vitrina mem- s 
branacea based upon specimens Fic. 41.—Helix fusca Mont., figured as Helix 
found on the Lomond Hills, Fife- = 7©”¢/4¢# by Capt. Brown (after Brown). 
shire, and which in the later editions of his work he regarded as identical 
with H. revelata, but authors now more correctly refer it to H. fusca. 
he honour of adding this species to the British fauna has been very 
generally accorded to Prof. E. Forbes, who found specimens on the Island 
of Guernsey, but that honour probably really belongs to Mr. J. C. Bellamy, 
who found specimens at Mevagissey, in Cornwall, and published under the 
name of Helix subvirescens a description and figure in 1839, and mentions 
that a Mr. Colley had previously found two dead shells, which he had 
referred to Helia subrufescens, a synonym of H. fusca Montagu. 
Diagnosis.— Hygromia revelata differs from H. hispida in its smaller 
size, more globose shape, greenish colour, rounder mouth, and the number 
and length of the periostracal hairs. 
From H. fusca it is separated by its smaller shell, the distinctly hairy 
investment, and the much more open umbilicus. 
INTERNALLY, it 1s separated from H. hispida by the vestigial dart sacs, 
the swollen vagina, and the enlarged median part of the penis sheath. 
H. fusca differs by having only a single dart sac and accessory gland, 
by the long whip-like flagellum, and by the very elongate spermatheca. 
Original Description.— Helix (Helicella) revelata De Feér., Prod. page 44, no. 273. 
Coquille: Orbiculaire, presque globuleuse, légerement striée, perforée, trés-mince 
et légére, diaphane, luisante, d’un vert-pale, hispide, poils rares, courts et 
jetés irréguligremente sur l’épiderme ; cinq tours convexes, le dernier plus 
grand relativement aux autres; ouver- 
ture ronde ; péristome simple et tran- CS) (y 
chant; sommet mameloné. Hauteur 13 X €& 
ane pees: ES 2 He te ¢ Fic. 45.—H. revelata Mich. (after Michaud). 
Cette coquille trés-voisine de helix sericea ‘2 
Drap. s’en distingue par sa taille plus petite, Pouverture de son ombilic qui est 
plus large, par sa couleur plus fonecée, son ouverture plus arrondie. Notre espéce 
est plus transparente, sa spire est moins élevée et sa suture plus profonde ; la dis- 
position, le nombre et la longueur de ses poils sert surtout a faire reconnaitre 
Pespece de Draparnaud. 
Habite : (les environs de Paris et d’Angers, De Férussac). Les valons des Alpes. 
Elle est rare (Mon Cabinet).—MiIcHAuUD, Complement, 1831, p. 27. 
