114 THE NAUTILUS. 



A. Apex irregularly wrinkled or wrinkles dislocated, broken into 

 granules. Subgeuus BULIMULUS s. sir. 

 All the species are South American and West Indian. 

 Bulimulm s. str., type B. exilis guadeloupensis. 

 Lejitomerus Alb., type B. limnseoides. 

 Rhi)ius Alb., type B. heterotrichus. 

 Plectostylus Beck, type B. peruvianus. 

 Sffutalm Beck, type B. proteus. 

 Nesiotes Alb., type B. nux. 



B. 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., 1 873). 



Ortliotomiitm C. & F., type B. sufflatus (Rabdotitg part, Alb., 

 not Rnbdota Dej., 1833 ;" Glohilimts C. & F., 1875, not Olobu- 



tiiw Orb., 1826. Thaumastus Auct. not Alb.) 

 Plicolumna Coop., type B rameutosa. 

 C. Apex smooth, rather mamillar. Subgenus BOSTRYX. 

 Species South American, mainly of Ecuador, Peru and Chili. 

 Lissoacme Pils., type B. erythrostomus. 

 Ataxiis Alb., type B. umbilicaris. 

 Hostryx Trosch., type B. solutus. 

 PeroncRUS Alb., type B. pupiformis. 



Geopyrgus Pils., type B. turritus (Pyrgus Alb. not Hubner). 

 The only group of Bulimulus extending into the United States is 

 Orthotomium. This includes schiedeanus, dealbatus, baileyi, monte- 

 -mini, sufflahis, pihtla, alternates 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 

 Jiiilimulus, narrow, pupiform species have been independently de- 

 veloped. 



( iemis Drymanis Alb., 1850. 



(= Goniognalhmus Cr. &. FUch. ; Otostomus Martens). 



Arboreal snails, never found on the ground when living. Apical 

 sculpture an extremely fine grating formed of vertical and spiral 

 strue intersecting at right angles. Radula peculiar. 



