HYALINIA PURA. 83 
The REPRODUCTIVE ORGANS, according to Lehmann, exhibit a small, yellowish, 
and granular OVOTESTIS ; the HERMAPHRODITE DUCT is sinuous and filiform; 
ALBUMEN GLAND linguiform, small, and yellowish ; 
the OVIDUCT or matrix is distinctly sacculate ; the es 
PROSTATE or sperm-duet is ribbon-like and = con- x, 
tinued below as a very delicate, thread-like, and 
comparatively short VAS DEFERENS, which enters 
the penis-sheath terminally ; PENIS-SHEATH com- 
paratively long and eylindrical, the lower region is 
glandular and swollen, and the distal end is also 
ehy 
thickened and distinctly clavate, but separated \ 
from the basal portion by a distinct constriction, \ 
apparently indicating the division of the true penial des ) 
and epiphallial regions, the former organ having a AV: yy 
lateral muscle; the slender terminal RETRACTOR 
MUSCLE is regarded by Lehmann as a flagellum ; 
FREE OVIDUCY short and direct; SPERMATHECA 
ovaliform, borne on a stout and bottle-shaped stem, Fic. 123.—Reproductive organs 
which is distinetly constricted at its junction with of //va@ima pura Alder (greatly 
the vesicle enlarged) after Lehmann. 
The LINGUAL RIBBON resembles that of H. nitidula in the comparatively large 
number of the aculeate marginal teeth. It is of the usual shape, and according 
to Schepmann, the Bavarian specimen examined by him had a formula of 
30 + 1+ 30, while Rev. E. Wake Bowell states that the formula of a Huntsham 
22 2 
speciinen is 42+ $+4+$+22, and Herr Clessin cites a specimen from the Island 
of Wollin as #°+2+4+2+42. The median tooth exhibits the character of the 
sub-genus Polita, to which this species belongs, in being fully as large or larger 
than the adjacent laterals ; it is tricuspidate, the middle cusp being especially 
strong and the side points well defined; the laterals are three in number, dis- 
tinctly and strongly bifid, but also show a blunt and obsolete endocone. Heer 
Schepmann figures the fourth tooth as a bifid marginal and clearly transitional, 
while the true marginals apparently vary in number from twenty-one to thirty on 
each side, and decrease regularly in size to the outer margin of the membrane, 
where the outermost tooth is little more than a basal plate. 
Le 1. 2. 3. 4. ete fot eee 
809 
Fic. 124.—Representative denticles from half a transverse row of the teeth of //yalinia pura, 
from Dinkelscherben, in Suabia x 600, illustrating the median, the laterals, and some of the marginal 
teeth (after Schepmann), The formula is given as 30+1+430. 
Food and Habits.—Hyalinia pura is at times not very uncommon 
among moss, decaying leaves, etc., living together in little colonies, at the 
roots of trees in woods and hedgerows or even in pastures, generally 
preferring a moist situation, and even living at times in company with 
H. nitida beneath stones in boggy places and entirely submerged, 
although Mr. Petch remarks upon it as a species characteristic of the 
elevated lands in East Yorkshire. According to Westerlund, it is really 
a lowland species, and in Scandinavia is especially characteristic of the 
region of the beech, though found more or less sporadically throughout 
the oak region, to the northern limits of the maple, lime, ash, elm, ete. 
In the Tyrol it has been found on the margin of the Schwarzenstein 
Glacier, is sub-alpine in habit in the Sudetic Mountains, living where 
no trees or only Pinus pumilio grows. In Switzerland, it attains an 
altitude of 3,500 feet at Sierre, in the Canton of Valais, while Dr. Bottger 
affirms its existence at a altitude of 7,000 feet in the Alps. 
It carries its shell almost horizontally, and is a very shy and timid 
though irritable animal, slow and lethargic in movement, and reluctant 
to crawl, differing thus from H. radiatula, which is bold, active, and 
