64 ANALOGOUS. 



bers by numerous transverse septa, which embrace each other with 

 reflected margins. It occurs in the Dublin limestone, and re- 

 sembles a coral or madrepore. 



AMPLEXUS. A generic name proposed by Captain Brown for 

 Helix pulchella, Drap. 112, tab. 107-134. Zurama, Leach. 



AMPULLARIA. Auct. {Ampulla, a rounded vessel). Fam. < k Peris- 

 toiniens," Lam. Ellipsostomata, Bl. — Descr. Spiral, globular, some- 

 times discoidal, frequently umbilicated, covered with a rounded, 

 horny epidermis ; spire short ; whorls rapidly enlarging ; aper- 

 ture elliptical, rounded anteriorly ; peristome nearly or quite 

 entire, thickened and slightly reflected ; operculum, testaceous, 

 annular, with a subcentral nucleus.— Obs. This genus of fresh- 

 water shells of which a few fossil species occur, is easily distin- 

 guished from other genera, by obvious characters, particularly by 

 a thick, horny, greenish-brown epidermis, and the rotundity in 

 form. One species, the A. Cornu-arietis 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 Ampul- 

 laria is longer than wide, and in Planorbis the contrary. Lanistes, 

 Montf. is described from a reversed species of Ampullaria. The 

 Ampullaria is vulgarly called the Idol Shell, and is said to be held 

 in great veneration by the South American Savages. The animal 

 has a large bag, opening beneath, placed on the side of the res- 

 piratory cavity. It is supposed 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. They have been brought as far as from 

 Egypt to Paris alive, packed in saw-dust. Ex. fig. 318. East 

 and West Indies, North Africa, South America, &c. 



AMPULLAMNA ? A genus formed for the reception of 



Ampullaria avellana. Fig. 538. From Australia. 



AMPULLINA ? Part of the genus Helicina, Auct. 



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

 which present a certain degree of resemblance to recent species; 

 but which are not sufficiently similar to warrant the use of the 

 term * identical,' or any other implying that they are of the same 

 species. 



