GASTEROPODA. HELICID®. 89 
Animal cinereous, passing into sooty black. Tentacula 
sooty-black, or black, passing into sooty-black. Under aspect 
of the upper tentacula, and the extremities of the under ones, 
hyaline, or somewhat pellucid. The foot is sometimes of a very 
obscure sooty-black colour. 
Peritreme slightly tinted with rose-red, or flesh colour ; teeth 
and lamellee of the aperture whitish. 
This elegant shell, which has been unknown to Concholo- 
gists for several years, was lately discovered near the entrance 
of a wood at Amersham, in Bucks, by my learned friend, the 
Provost of Eton, who most kindly supplied me with the living 
specimens, from which the figures have been executed. 
As it is not the species referred to by English Conchologists, 
and as it has more than three teeth, I have named it after Dr. 
W. G. Maton, one of the authors of that elaborate historical 
Account of Testaceological Writers, which graces the seventh 
volume of the Transactions of the Linnzan Society of London. 
STIRPS IX. 
The genera of this Stirps have all an obtusely turrited shell, 
the aperture of which has a margined peritreme on its lateral 
and anterior aspects, and a rudimentary peritreme in its pos- 
terior aspect. The umbilicus is perforated. 
Synopsis Generum. 
Testa cylindrica, acuminato-turrita, ad apicem 
obtusiuscula. Tentacula superiora medio- 
pete) iitetiota, DreVid., 0... =... ho se Doe ABIDA: 
Testa obtusé turrita, ad apicem abrupté ob- 
tusa. Tentacula superiora mediocria: in- 
PERIENCE 9 oe oo ns ae 3, 0 Oe, PUPIEE AS 
Testa obtusé turrita, ad apicem subgradatim 
obtusa. Tentacula superiora mediocria : in- 
feriora brevissima, obsoleta............ 40. VERTIGO. 
