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170 MONOGRAPH OF BRITISH LAND AND FRESHWATER MOLLUSCA. 
Pyramidula rupeStris (Draparnaud). 
1801 Helix rupestris Draparnaud, Tabl. Moll., p. 71, no. 4. 
1801 — pusilla Vallot, Exerc. d’Hist. Nat., p. 5. 
1803. — wmbilicata Montagu, Test., Brit: p: 434, ple is, i. 2: 
1821 — _ sazxatilis Hartmann, Syst. Gast., p. 52. 
1841 — adliena Ziegl., Pfeitfer’s Symb., De Its ai) 
1841 — spirula Villa, Disp. Syst. Conch. , Dp. 56. 
1855 (Hygromane) rupestris Moq.-Tand., Hist. Nat.,ii., p. 192, pl. xv., ff. 10-13. 
1826 Helicella rupestris Risso, Hist. Nat. Eur. Mer. 5 Wen 10 69. 
1833 Pyramidula rupestris Fitzing yer, Syst. Verz., p. oe 
1833 Turbo myrmecidis Seacchi, Osserv, LOO lee as 
1837 Patula rupestris Held, Isis, p. 916. 
1837 Euryomphala wnbilicata Beck, Ind. Moll., p. 9. 
1840 Delomphalus saxatilis Hartmann, Gast. i., p. 122, pl. 37, ff. 4-6. 
1840 Zonites umbilicatus Gray’s Turton, Brit. Shells, p. 166, pl. 5, f. 4-5. 
1852 — rupestris Leach, Syn. Moll., p. 74. 
ISTORY.— Pyramidulu ru- 
pestris (rupestris, rock- 
loving) 1s a very distinct species, 
and was first discriminated by 
Studer, who applied to it the 
name of Helix rupestris, in the 
Fauna Helvetica, published in 
1789 as an Appendix to ‘Coxe’s 
'ravels in Switzerland,’ but he 
gave no description or figure. 
Draparnaud described the same 
species in 1801, adopting Studer’s 
name, thus antedating Colonel 
Montagu, who in 1805 applied 
the name of Helix umbilicata to 
the British specimens of the 
same shell. 
This little rupicolous species 
is here associated with the Rey. 
Prof. H. M. Gwatkin, M.A., D.D., 
of Cambridge University, who has 
devoted his attention to a study 
of the molluscan radula, of which 
he possesses one of the finest and 
most complete collections in exist- 
ence. No one is more intimately 
identified with the progress of our 
knowledge of the dental structure 
of our British species, and it is from his exquisite preparations of the 
mandible and radula of the present species that the illustrations of these 
organs have been drawn. 
Diagnosis.—'Ihough having much of the aspect of P. pygmaum, this 
species is readily distinguished by its much larger size, more elevated spire, 
and uniform and more opaque dark-brown colouring. From the young of 
P. rotundata it differs in its uniform dark colouring and more risen spire; 
the latter species being very flat above, with transverse rib-like strie and 
caripate periphery. 
