~<—_ 
326 MONOGRAPH OF BRITISH LAND AND FRESHWATER MOLLUSCA. 
Helix hortensis Miiller. 
1758 Helix nemoralis L., (pars) Syst. Nat., ed. x., vol. i., p. 773, no. 604. 
1774 Helix hortensis Miiller, Verm. Hist., Wey os 32, no. 247. 
180L = =— = hybrida and fusca Poiret, Coq. Aisne, p. 71. 
1821 — mutabilis var. a Hartmann, Neue Alpina, i., p. 242. 
1837. —_ subglobosa Binney, Boston Journ. Nat. Hist., 1. , p. 485, pl. *xvi., Pye 
1862. — nemoralis var. hortensis Jettreys, Brit. Conch. silos A 186. 
1778 Cochlea fasciata DaCosta, Test. Brit., p. 76, pl. v., f. 4-6 
1836 Acavus hortensis Kryn., Hel. Ross., ix., p. 162. 
1837 Helicogena hortensis and hybrida Beck, Index Moll., p. 39. 
1837 Cepwea hortensis Held, Isis, p. 910. 
1852 Tachea hortensis Leach, Synopsis, p. 62. 
ISTORY. — Helix hortensis (hortensis, 
living in gardens) was included with H. 
nemoralis by Linné and for more than a 
century this view was almost universally 
accepted, but its specific status 1s now 
firmly established by the differences de- 
moustrated to exist in its organization. 
Dr. Gray has accredited to Dr. Martin 
Lister the introduction of this species to 
the British fauna, and Mr. E. A. Smith 
informs me that pl. 57, f. 54, of Lister’s 
“Historie sive synopsis methodic con- 
chyliorum,” published in 1685, depicts 
six shells collectively indicated by the 
term Cochlea interdum unicolor, interdum 
uariegauta, ttem uarijs fasiys depicta, of 
which one undoubtedly represents a 
i white-lipped shell, while the remaining 
. five are clearly the darker-lipped form 
known as Helix nemoralis. 
Dr. Amos Binney, thinking it probable that the American specimens were 
distinct from the European species, applied the name swhglobosa to them. 
his species is dedicated to Otto F. Miiller, the celebrated Danish 
naturalist, who first differentiated it from Helix nemoralis, with which 
species it was combined by Linné and most subsequent authors. 
Diagnosis.—//. hortensis is distinguished from Hl. nemoralis by its 
smaller size, more globose shape, white aperture, and thinner and more 
glossy shell; moreover there is much less band variation, there is a larger 
proportion of bandless and 5-banded shells, and the commonness or rarity 
of the band formule is quite different in the two species. 
INTERNALLY, the differences are striking, the chief divergence being the 
structure of the gypsobelum or “‘love-dart,” which, in place of presenting 
the four simple longitudinal blades with connecting crescentic films, as in 
H. nemoralis, has the four blades deeply cleft and widely reflected along 
their entire length, forming thus eight sharp divaricating blades ; there are 
also no crescentic films between the blades, which terminate abruptly at the 
base, and not gradually, as in //. nemoralis ; the vaginal mucus glands are 
also usually more branched than in nemoralis, and instead of being simply 
and uniformly digitate, are swollen or sacculate at the extremities. 
