MONOGRAPH OF BRITISH LAND AND FRESHWATER MOLLUSCA, 67 
Sus-GEeNnus Politw Held. 
Hyalinia nitidula (Draparnaud). 
1805 Helix nitidula Draparnand, Hist. Moll. France, p. 117. 
1831 — nitens Michaud, Compl., p. 44, pl. xv., f. 1-3. 
1837 — helmii Gilbertson Ms., Alder, Mag. Zool. and Bot., p. 107. 
1833 Oxychelus nitidulus Fitz., Syst. Verz., p. 100. 
1837 Helicella nitidula Beck, Index Moll., p. 6. 
1837 Polita nitidula Held in Isis, p. 916. 
1840 Zonites nitidulus Gray, Turton’s Manual, p. 172, pl. xii., f. 136. 
1869 — subnitens Bourenignat, Not. sur Zonites. 
1876 Hyalina nitidula Weinland, Weichth. Schwab. Alb., p. 35. 
1871 — (Euhyalina) nitidula WKobelt, Catal. Eur. Binnenconch., p. 5. 
1877 Hyalinia nitiduda Westerlund, Faun. Eur. Moll. Extram., p. 24. 
1891 Vitrea (Polita) nitidula Smith, Journ. of Conch., vi., p. 339. 
ISTORY.—AHyalinia nitidula (nitidula, 
not very glossy) is the type of the section 
Politu of Held, and is distinguished ex- 
ternally from Huhyalinia by the com- 
paratively dull and lustreless surface of 
the shell as well as by the obsolete dorsal 
and lateral body grooves of the animal. 
Internally, the odontophore shows a 
distinct central area of approximately 
equal-sized teeth, and a greatly increased 
number of marginal teeth, with an ab- 
sence of the medial expansion of the vas 
deferens which is so conspicuous a feature 
in the Huhyalinic. 
The present species is here associated 
with Heer M. M. Schepmann, of Rhoon, 
near Rotterdam, who has so thoroughly 
studied the dentition of the present and 
allied species. 
H. nitidula was first properly differen- 
EE tiated by Draparnaud, whose 
5 : ae description is especially applic- 
a able to the form with the less 
expanded aperture, which is 
regarded by many continental conchologists as merely the young and 
incomplete state of the Helix nitens of Michaud, which name they 
therefore propose to substitute for the prior one of Draparnaud; other 
authors, on the contrary, regard the two forms as distinct species. 
Diagnosis.—The shell of Hyalinia nitidula may be distinguished 
from those of 17. cellaria and H. helvetica by its smaller size, by possessing 
one whorl jess, and a much wider umbilicus, as well as by its dull and 
waxy appearance, and the marked expansion of the last whorl as it 
approaches the aperture. 
The ANIMAL is remarkable for the indistinct or deficient dorsal and 
lateral grooves, the strong dorsal tuberculation, and thicker tentacles. 
INTERNALLY, this species may be separated from all the preceding species 
by the absence of the medial enlargement of the vas deferens and vaginal 
glands, as well as by the much greater number of the marginal teeth, 
