114 THE NAUTILUS. 
A.—Apex irregularly wrinkled or wrinkles dislocated, broken into 
granules. Subgenus BuLIMULYs s. str. 
All the species are South American and West Indian. 
Bulimulus s. str., type B. exilis = guadeloupensis. 
Leptomerus Alb., type B. limneeoides. 
Rhinus Alb., type B. heterotrichus. 
Plectostylus Beck, type B. peruvianus. 
Scutalus Beck, type B. proteus. 
Nesiotes Alb., type B. nux. 
£.—Apex with vertical regular riblets. Subgenus ORTHOTOMIUM. 
Species of Lower California and Northern Mexico, extending 
into U.S. . 
Sonorina Pils., type B. spirifer (Leptobyrsus C. & F., 1875, not 
Leptobyrsa Stal., 1873). 
Orthotomium C. & F., type B. sufflatus (Rabdotus part, Alb., 
not Rabdota Dej., 1833; Globulinus C. & F., 1875, not Globu- | 
lina Orb., 1826. Thawmastus Auct. not Alb.) 
Plicolumna Coop., type B ramentosa. 
C.—Apex smooth, rather mamillar. Subgenus Bosrryx. 
Species South American, mainly of Ecuador, Peru and Chili. 
Lissoaeme Pils., type B. erythrostomus. 
Ataxus Alb., type B. umbilicaris. 
Bostryx Trosch., type B. solutus. 
Peroneus Alb., type B. pupiformis. 
Geopyrgus Pils., type B. turritus (Pyrgus Alb. not Htibner). 
The only group of Bulimulus extending into the United States is 
Orthotomium. This includes schiedeanus, dealbatus, baileyi, monte- 
zuma, sufflatus, pilula, alternatus and their allies. It is very char- 
acteristic of the Sonoran life-area, as originally limited by Merriam. 
It is somewhat remarkable that in each of the three subgenera of 
Bulimulus, narrow, pupiform species have been independently de- 
veloped. 
Genus Drymeus Alb., 1850. 
= Goniognathmus Cr. & Fisch. ; Otostomus Martens). 
Arboreal snails, never found on the ground when living. Apical 
sculpture an extremely fine grating formed of vertical and spiral 
striz intersecting at right angles. Radula peculiar. 
