HYGROMIA REVELATA. 4] 
I have, however, carefully collected such information as was available, 
and whether some of the more distinct forms may eventually be justly 
separated from /. revelata remains to be confirmed by demonstration of 
structural differences, but the testaceological divergences between the 
various forms seem to be usually slight. 
A variety from Oporto, named by Silva var. major, is described as a 
darker coloured form, with the last whorl somewhat more deflected, and 
having a diameter of 74 mill. and an altitude of 44 mill., but these dimen- 
sions do not apparently differ from the size of the type. 
VARIATIONS OF SHELL. 
Var. ptilota Bourguignat. 
Helix ptilota Bourg., Mal. Bretagne, 1860, p. 59. 
SHELL described by M. Bourguignat as small, 
and depressed in shape, equally convex above and 
below, thin, translucent, and of a pale, dull greenish- 
brown colour; apex smooth, of a rich black, without 
striations or hairs, rather strongly striate, and beset 
with numerous small and rigid white hairs, which are Coe 2) Cx) 
arranged in series in an inverse direction to the lines oe es 
of growth, which is incorrectly averred not to be the Fic. 55.—Helix ptilota Bourg., 
ease in H. occidentalis, in which also the hairs are — natural size and enlarged (after 
stated to be longer and more irregularly distributed. Bontetena): 
Whorls 4, rapidly increasing in size; suture deep; last whorl more dilated and 
slightly deflected at the mouth, which is roundly lunate; peristome simple and 
direct, but slightly reflected round the small and narrow umbilicus. 
Diam., 54 mill. ; alt., 4 mill. 
France—Rather rare in the hedges bordering the road between Vannes and 
Auray, about three kilometres from the former place, in the department of Morbihan. 
Var. coimbricensis Silva. 
Helix coimbrvicensis Silva, Journ. Soc. Math., Phys., e Nat., Lisboa, 1887. 
SHELL globosely depressed, with a blunt spire, thin, greenish horn colour, 
slightly striated, and beset with very short whitish hairs. Whorls 33, convex, 
rapidly increasing in size, the last very large and convex, and gradually descending 
in front. Aperture rounded, somewhat obliquely oblong. Peristome simple. 
Umbilicus perforate, and more or less covered by the reflection of the pillar lip. 
Diam., 6 mill. ; alt., 4 mill. 
Portugal—Coimbra and Bussaco, province of Beira (Westl., Binnence. , 1889, p. 61). 
Var. nevesiana Silva. 
Helix nevesiana Silva, Journ. Soc. Math., Phys., e Nat., Lisboa, 1887, p.1. 
SHELL depressed and umbilicated, opaque yellowish olive, with diffuse wrinkled 
striation, and irregularly covered with short hairs. Whorls 4, convex, rather 
quickly but irregularly increasing, the last large, very convex beneath, rapidly 
descending in front and deflected at the aperture; suture very deep. Aperture 
obliquely rounded and enlarged, but narrow interiorly. Peristome simple and 
direct, reflected only above, margins closely convergent. Diam., 6} mill. ; alt., 4 mill. 
J 
Portugal—Sernache das Alhos, Beira (Westl., Binnenc., 1889, p. 62). 
Var. platylasia Bourguignat. 
Helix platylasia (Bourg.) Silva, Journ. Conch. Math., Phys., e Nat., Lisboa, 1887. p. 5. 
SHELL very depressed and almost flat, but quite convex beneath, yellowish or 
greenish horn coloured, beset with small whitish and mostly recumbent hairs. 
Whorls increasing regularly in size, the last not expanded, but gradually descend- 
ing and strongly deflected at the aperture, which is oblique and moderately rounded 
with approximating margins. Umbilicus more open than in var. willula. 
Portugal and Algeria—(Westl., Binnenc., 1889, p. 62). 
