ANALOGOUS. 65 



cliambers by numerous transverse septa, which embrace each 

 other with reflected margins. It occurs in the Dublin lime- 

 stone, and resembles a coral or madrepore. PI. xxi. fig. 463. 



AMPLEXUS. A generic name proposed by Captain Brown for 

 Helix pdchella. Drap. 112, tab. 107-134 ; and other similar 

 species. Zurama, Leach. 



AMPULLAEIA. Lamarck, 1801. (Ampulla, a, rowaded Yessel.) 

 Fam. "Peristomiens," Lam. Ellipsostomata, Bl. — Descr. Spiral, 

 globular, sometimes discoidal, frequently umbilicated, covered 

 with a rounded, horny epidermis ; spire short ; whorls rapidly 

 enlarging ; aperture elliptical, rounded anteriorly ; peristome 

 nearly or quite entire, thickened, and slightly reflected ; opercu- 

 lum, testaceous, annidar, with a sub-central nucleus. — Obs. 

 This genus of fresh-water shells of which a few fossil species 

 occur, is easily distinguished from other genera by obvious 

 characters, particularly by a thick, horny, greenish-brown 

 epidermis, and the rotundity in form. One species (fig. 320) 

 the A. Cornu-arietis, {Genus, Maeisa, Grray,) which forms the 

 type of Lamarck's genus Planorbis, requires notice on account 

 of its flatness, but may be known by the aperture which in the 

 Ampullaria is longer than wide, and in Planorbis the contrary. 

 Lanistes, Montf. is described from a reversed species of Ampul- 

 laria, fig. 319. The AmpuUaria is vulgarly called the Idol 

 Shell, and is said to be held in high veneration by the South 

 American savages. The animal has a large bag, opening be- 

 neath, placed on the side of the respiratory cavity. It is sup- 

 posed that the animal has the power of filling this bag with 

 water, and that it is thus enabled to live a long time out 

 of water. AmpuUarise have been brought as far as from Egypt 

 to Paris alive, packed in sawdust. East and "West Indies, North 

 Africa, South America, &e. PI. xiv. fig. 318. 



AMPTJLLINA. BlainviUe, 1825. Part of the genus Helicina, 

 Auct. 



AMUSIUM. Megerle, 1811. A generic name for species of 

 Pecten, which are flat and smooth outside. Pecten Pleuronectes, 



ANALOGOUS. A term applied to certain species of fossil shells, 



