2*76 AMPULLARIID^. 



produced into two long tentacular processes ; tentacles extremely 

 elongated, slender. Dentition (xi, 22, 23). Inhabits lakes and 

 rivers throughout the warmer parts of the world, retiring deep 

 into the mud in the dry season, and capable of surviving a 

 drought, or removal from the water for several j^ears. In the 

 Lake Mareotis, and at the mouth of the Indus, Ampullarise are 

 abundant, mixed with marine shells. Their eggs are large, 

 enclosed in calcareous capsules, and aggregated in globular 

 masses around the stems of plants, etc. 



These fluviatile mollusks represent in the ponds and rivers of 

 the tropics, the Paludinae of more temperate climates.. Although 

 distinct gills exist, the respiratory cavity is very large and 

 partl}'^ closed, so as to enable these animals to live a long time 

 out of water ; in fact, they appear to be truly amphibious. 



Ampullaria, Lam. 



Apple-snail. Etym. — Ampulla^ a globular flask. 



Syn. — Pachj'labra, Swains. 



Distr. — 150 sp. Tropical, in fresh water. West Indies, Cen- 

 tral and South America, southern portion of the United States, 

 Africa, India, East Indies, A. ampullacea^ Linn. (Ixxiv, 15). 



Shell globular, with short spire ; epidermis green, polished, 

 sometimes banded or spotted ; usually umbilicated. 



'Typical. — Aperture slightly thickened within the margin. 

 Operculum with an inner calcareous layer. Oriental exclusively. 



SAULEA, Gray. Shell ovate, subglobose, very thin , parchment- 

 like, elastic, dark-colored, variegated, covered with a very thin, 

 hard, olive epidermis; upper whorls minutely keeled, others 

 rounded ; axis imperforate. Operculum thin, shelly, elastic. 

 Sierra Leone. A. vitrea, Gray. 



POMUS, Humphrey. Differs from Ampullaria in the absence 

 of a thickened internal ledge of the lip, and in the operculum 

 being entirely horny. American exclusively. A. canaliculata, 

 Lam. (Ixxiv, 16). 



POMELLA, Gray. Shell suboval, solid, not umbilicated ; whorls 

 striated, the:^ last very large ; spire ver}' short or depressed ; 

 aperture very large ; peristome thin, expanded. Operculum 

 horny. Soiith America. A. neritoides, d'Orb. (Ixxiv, 17). 



AsoLENE, d'Orb. 



Syn. — Ampulloidea, d'Orb. Ampullaroides, Gray. 



Distr. — South America. A. Platse^ d'Orb. (Ixxiv, 18). 



Shell subglobular, spire slightly elevated ; aperture oval ; the 

 inner lip somewhat thickened, forming a continuous peristome. 

 Operculum corneous, with an inner calcareous layer. Animal 

 without a long respiratory siphon. 



