4 HYGROMIA STRIOLATA. 
After careful investigation, I have adopted the name Helix striolata of 
C. Pfeiffer for this species as the oldest which can be satisfactorily deter- 
mined by the original evidence. All anterior names—cltenuna, montana, 
circinuta, glubella, ete.—are subject to the gravest objections by the various 
authors who have treated of the species and differently apply the names. 
Diagnosis.—'l'he differences of //ygromia striolata from the closely- 
allied H/. hispida are really more testaceological than anatomical. 
he sHELL differs in its larger size, less compact and more depressed 
shape, and the absence of epidermal hairs in the adult. ‘he whorls are 
also usually angulate at the periphery, especially in the immature stage. 
INTERNALLY, the REPRODUCTIVE SYSTEM has not yet been shown to offer 
any constant difference from that of //. hispida, but the mandible in the 
specimens examined shows fewer riblets, while the teeth of the radula are 
noticeably laterally compressed and more elongate than in that species. 
Description of Animal.—The ANIMAL, though very variable in its pigmentation, 
usually has the BoDy of an ashy-grey, and is strongly and closely tuberculate, the 
summits of the tubercles appearing paler owing to an aggregation of minute whitish 
specks ; the DORSAL GROOVES are well marked and enclose a row of closely-arranged 
oblong tubercles ; the LATERAL GROOYES are also clearly defined ; MANTLE greyish. 
In the less-deeply pigmented animals the tentacular RETRACTORS show through the 
skin as broad blackish bands, extending from the tentacles along each side of the 
body. OMMATOPHORES long and not very slender, but finely granulate, with oval 
tips, eye specks black ; lower tentacles very short. Foor whitish-grey, somewhat 
short, blunt in front, and obtusely-pointed behind. 
Description of Shell.—'The SHELL is composed of 6-7 whorls, of a subglobosely 
depressed shape, perceptibly keeled or angulated at the periphery, which is some- 
times encircled by a pale peripheral zone, with an obtusely convex spire and 
channeled suture, especially in the earlier 
stages of growth ; the COLOUR is usually rufous- 
brown or a dusky-yellowish with darker shades 
or mottlings, somewhat irregularly striate, and 
usually destitute when adult of the periostracal 
hairs, which are frequently distinctly perceptible 
in the young stage, and may sometimes persist 
in the adult; the APEX is glossy, with delicate 
spiral seulpture. APERTURE obliquely lunate, 
and inflected ; Lip thin, and slightly expanded, 
with a milk-white submarginal RIB, which is 
most strongly developed basally, and differs from 
that of the true or typical Helices in being com- — _ E'G. 5.—Young shell of /. striolata 
are : .* : < 5, Grange, Mr. F. Booth, showing the 
paratively distant from the mouth margin at jicid epidermis (from photograph by 
the suture, though close toit basally. UMBILICUS Mr. W. Bagshaw). 
distinet and open, but not wide. 
Diam. 12 mill. ; alt. 7) mill. Average weight of British adult shells, 1 grain. 
The EPIPHRAGM is thin, vitreous, and nearly flush with the aperture of the shell. 
INTERNALLY, the NERVE-RING is fairly 
compact, the central opening small, but 
the fusion of the VISCERAL GANGLIA is not 
quite complete, and the position of the 
pleural centres is frequently shown by 
faint traces of their demareation. The 
paired PEDAL or locomotory ganglia are 
also compact, and show the OrocystTs on mete: Fic. 7. 
the posterior outside corners ; the LIVER or ic: G6 eruesiie’ Ok Dipeponti abate 
digestive gland is of a dark olive-brown to show the arrangement of the supra- and sub- 
colour, and the hepatic artery is of an — csophageal ganglia, highly magnified. 
inconspicuous greyish-white, while the Fic. 7.—Lower aspect of the subcesophageal 
KIDNEY or renal organ is of the usual ganglia, showing the otocysts, highly magnified. 
elongately triangular shape, and of a buff colour with dusky streaks. 
