THE YOUNG NATURALIST. 



809 



Oblong'a. — This species has a smaller 

 shell, transparent and yellowish, with 

 rounded whorls, and smaller aperture. It 

 has only been found in a few localities, 

 generally near the seaside. It buries itself 

 in the sand during the winter. 



Genus, Zonites. 



All the shells of this genus are thin, horny 

 or glassy in appearance, without colored 

 stripes or markings ; in form they are more 

 or less flat and button-shaped ; the spire is 

 very little raised, and the umbilicus distinct. 

 The species are Cellar ius, Alliarius, Nitiiulus, 

 Purus, Radiatulus, Nitidus, Excavatus, and 

 Crystal! in us. 



CellarillS.— This shell is the largest of 

 the genu.-., it measures about half-an-inch 

 across. It is very fiat, pale yellowish, smooth 

 and bright, with rounded whorls, and the 

 umbilicus rather small. It inhabits drains 

 and cellars. 



AlliarillS — This is smaller than the pre- 

 ceding, the shell not quite so flat ; smooth, 

 horny, and transparent, with small umbilicus. 

 It is. found in gardens. 



NitidulUS — This is nearly as large a 

 shell as cellar ius, it is not so glossy, being dull 

 yellowish brown on the upper side, and 

 opaque white beneath, it has a rather large 

 umbilicus. It is found under stones and 

 moss. 



PurilS. — This shell is small, being less 

 than a quarter of an inch across, it is white 

 and transparent, with large umbilicus. The 

 animal is white with two black lines. It is 

 found in woods. 



Radiatulus. — This is very similar in 

 appearance to the last, but the umbilicus is 

 smaller, and the shell is regularly ribbed or 

 striated ; the animal moreover is black. It is 

 found among moss and under stones. 



Nitidus. — The shell is small, though 

 larger than either of the last two, it is bright j 

 and glossy, reddish brown, and with umbilicus 

 rather large. 



Excavatus. — This resembles the last, j 



but the umbilicus is larger, opening out in a 

 | spiral manner. It is a local species, occurring 

 in various parts of Britain, about decayed 

 j timber. 



CrystaliiriUS.— This is the smallest of 

 the genus. The shell is fiat, transparent, 

 j greenish white, and shining ; the umbilicus 

 ' is very small ; the animal is white. It is 

 j common throughout the country, under 

 j stones, among moss, &c. 



Genus, Helix. 

 Many of the shells in this genus are very 

 similar in form to those of the preceding, but 

 they are not generally so fiat, the typical 

 form being almost globular, and while the 

 i shells of Zonites have all, more or less, a 

 | bright and glossy surface, this is not the case 

 with these ; they are often prettily colored, 

 with darker bands and markings ; most of 

 them have an umbilicus. The animal has 

 four tentacles, the upper pair being much 

 longer than the lower. The species are 

 Aspersa, Potnatia, Arbustorum, Nemordlis, Can- 

 tiana, Carthusians, Pisana, Virgata, Fasciohita, 

 Ericeto; 'inn, Obvoluta, Lapicula , Rupescois , His- 

 pida, Scricea, Revelata, Fusca, Fulva, Lamellata, 

 Aculeata, Pulchella, Rotundata, Rupcstris, and 

 Pygiitaa : — in all twenty-four species. 



Aspersa — This is the common garden 

 snail, and is one of the largest land shells we 

 have, H. pomatia only, exceeding it in size. 

 A full grown specimen measures about one 

 and a half inches across. The shell is 

 generally brownish yellow, with dark brown 

 markings, forming interrupted bands, follow- 

 ing the direction of the whorls, but it is very 

 variable, sometimes there are four of these 

 bands, the first, third, and fourth being 

 narrow, and the second broader, sometimes 

 only two broad bands of brown blotches, 

 some specimens have the whole of the surface 

 mottled with dark brown, while again there 

 are others pale yellowish, without any dark 

 band or markings ; these bands and blotches 

 are discernible on the inside of the shell, but 

 not so well defined, the lip is white, and 



