404 “MOLLUSCA. 
GASTROPODA PROSOBRANCHIA*. 
AMPULLARIA. 
Ampullaria, Lamarck, Mém. Soc. d’Hist. Nat. 1799, p. 76; Hist. Nat. des Anim. sans Vert. ed. 1, 
vi. 2, p. 176; ed. 2, viii. p. 527; Philippi, in Martini & Chemnitz, Syst. Conch.-Cab. ed. 2, 
i. no. 20 (1851); Reeve, Conch. Icon. x. (1858); Fischer & Crosse, Miss. Scient. Mex., 
Mollusca, ii. p. 223. 
Shell more or less globose, with green or brown periostracum, spire short, last whorl 
rounded, swollen; umbilicus in most of the species open; aperture longer (higher) 
than broad, acutangular above, rounded beneath. Operculum concentrical, in all 
American species horny. 
A pair of very long, filiform, tapering feelers, the eyes on distinct prominences at 
their base externally; a second pair of shorter conical feelers in front of the projecting 
muzzle. On the left side a long feeler-like tube, leading the water to the gills (except 
in the subgenus Asolene). Close to the gill-cavity a distinct compartment adapted for 
air-breathing. This last-mentioned structure enables the animal to retain its vitality 
for months or even years in a dry state, which is very useful to it in the dry season, if 
the ponds are dried up f. 
Eggs round, with calcareous brightly-coloured shell, rose, scarlet, or green, deposited 
in clusters on aquatic plants. 
For further systematic and anatomical particulars, see Fischer and Crosse, loc. cit. 
Very young shells of various American species show spiral lines of fine hairs or 
scales; they are distinctly visible in the young shells collected at Vera Cruz by 
H. H. Smith (see Tab. XXII. fig. 11 a), which belong without doubt to A. flagellata, 
Say; Fischer and Crosse mention a similar character in A. belizensis. 
Geographical distribution circumtropical, being represented in Tropical Africa, in 
India, the Malay Archipelago as far east as the island of Celebes, and extending in 
America from Georgia, Florida, and Eastern Mexico (Papantla) to Argentina. They 
are wanting, however, in the central parts of Mexico, Guatemala, and Costa Rica. 
Tate’s note on the habits of A. (Pomus) pyrum (=hondurasensis, Reeve)—on the 
muddy bottom of still water, but also sometimes observed floating—is probably 
applicable to all the Mexican and Central-American species. 
In 1858 I tried to arrange the numerous American species in several groups, 
according to the general shape and aspect of the shell (Malakozoologische Blatter, iv. 
* As most of the genera here treated belong to a separate family, I prefer to characterize the genera only 
in this work. 
tT There are recorded instances of specimens having been preserved for several years in collections, and 
then reviving when placed in lukewarm water, but they always died soon afterwards, 
