BULIMULUS. 



Genus BULIMULUS Leach (Continued). 



DIVISION II. Bulimuli with the nepionic whorls sculptured with 

 waved, zig-zag or irregular subvertical wrinkles, or with the wrinkles 

 dislocated and broken more or less into granules or a netted pattern. 



This group, the second of three defined on p. 127, Volume X of 

 this work, is characteristic of tropical and temperate South America, 

 but numerously represented in Central America, with species ex- 

 tending as far north as Yucatan and Vera Cruz, and also in the 

 West Indian Islands, where it is mainly developed in the Carribean 

 chain. 



Aside from the above-mentioned features of the antenatal shell, 

 there are no definite shell characters special to the group holding 

 throughout its several members. The peristome, while generally 

 simple, is in some forms expanded or reflexed; and one-colored, 

 banded and elaborately spotted species occur. In one rather numer- 

 ous group of species the apical sculpture is extremely shallow and 

 often hardly perceptible in adult specimens. 



Four subgenera are distinguishable, although only the first of 

 them stands conspicuously apart. 



1. Subgenus PLECTOSTYLUS Beck. Shell imperforate, ovate or ob- 



long, somewhat Succinea-shaped ; aperture ovate, large, the 

 peristome simple and unexpanded, columella with a long fold 

 or concave. Generally conspicuously speckled or streaked. 

 Distribution, Chili and Peru, along the Pacific. (Page 2.). 



2. Subgenus SCUTALUS Albers. Shell perforate or umbilicate, ovate- 



conic ; aperture ovate, the peristome either expanded, thick- 

 ened, or simple. Columella not distinctly folded, its edge re- 

 flexed ; mainly opaque and rather solid shells, with banded, 

 streaked or spotted coloration. Distribution, Andean plateau, 

 from Argentina to Ecuador. (Page 12.). 



3. Subgenus BULIMULUS Leach. Shell perforate or umbilicate, 



ovate-conic or oblong, the aperture ovate, peristome thin and 

 simple, or (rarely) thickened within or slightly expanded. Col- 

 umellar lip reflexed. Mainly rather thin shells of corneous tex- 

 ture, a minimum amount of lime, and brown or few-banded 

 coloring. Distribution, Central America, northern and east- 

 ern South America, and the West Indies. (Page 35.). 



4. Subgenus RHINUS Albers. Shell umbilicate, ovate or oblong, 



thin or solid, the peristome narrowly expanded or reflexed, 

 1 



