HELICINID. 291 
animals of the Cyclophoride, but are considerably more loco- 
motive and lively ; in common with some other mollusks, as the 
Neritide and Ellobiidz, they possess the faculty of removing 
the inner septa and columella of the shell. 
Heticina, Lam. 
Syn.—Ampullina, Blainv. Pitonillus, Montf. 
Distr.—350 sp. West Indies, tropical America, Pacific 
Islands, Australian Islands, Philippines. H. variegata, Orb. 
(xxvii, 28). 
Shell globose, depressed or keeled, callous beneath ; aperture 
squarish or semilunar; columella flattened; peristome simple, 
expanded. Operculum shelly or membranous, squarish or semi- 
ovate, lamellar. 
OLIGYRA, Say. Shell subglobular or conic, spire and last whorl 
of about equal height, peristome expanded. H. occulta, Say. 
United States. 
PACHYSTOMA, Swainson. Shell conically depressed, carinated. 
H agglutinans, Sowb. (xxvii, 29, 30). 
p@NIA, H. and A. Adams. Peristome subdentate interiorly. 
H. depressa, Gray (Ixxvii, 31). 
IDESA, H. and A. Adams. Peristome simple,sharp. H. rotunda, 
Orb. (Ixxvii, 32). 
EMODA, H. and A. Adams. Peristome simple, thick, obtuse. 
H. festiva, Sowb. (1xxvii, 33). 
PERENNA, Guppy, 1867. Shell depressed, whorls lirate and 
carinate. Operculum thin, suboval, concentrically striate, 
nucleus subeentral. H. lamellosa, Guppy. Isl. Trinidad. 
DAWSONELLA, Bradley. Aperture small, lip thickened within, 
columella with a wide-spreading linguiform callus covering the 
axis. Carboniferous; United States. H. Meeki, Bradley 
(Ixxvii, 34). 
TROCHATELLA, Swainson. 
Distr.—34 sp. West Indies. 7. constellata, Morel. (1xxvii, 35). 
Shell trochiform or globular-conic; aperture subtriangular ; 
peristome simple, expanded ; base not callous. 
vianA, H. and A. Adams. (Rhynchocheila, Shutt. Hapata, 
Gray.) Shell subearinated; lip with a superior sinus. 7. regina, 
Morel. (Ixxvii, 36). 
ScHAZICHEILA, Shuttleworth. 
Distr.—5 sp. West Indies, Central America. S. alata, Menke 
(Ixxvii, 37, 38). 
Shell with spiral epidermal fringes; peristome profoundly 
incised at the suture. Operculum thin, testaceous, with an intra- 
marginal rib. 
