BULIMULIN.fi. 



d 2 . Perforate, rimate or umbilicate, smaller ; plain, 

 streaked or banded. 



Bulimulus, division II, xi, p. 1. 

 c 1 . Australasian genera. 



d. Aurieuloid, the lip thickened, expanded or re- 

 flexed. Placostylus, xiii, 19. 

 d 1 . Bulimulus-like, the lip simple. 



Bolhrienibryon, xiii, 1. 

 a 4 . Apical whorls spirally striate ; aperture toothed. 



Macrodontes, xiv, 29. 



* 



Subfamily I. BULIMULINVE. 



The numerous genera of this subfamily may be classified pro- 

 visionally thus : 



1. Radula loith teeth of the normal or unspecialized Helicid type.. 



(American genera.) 

 a. Shell rather large, ovate or oblong. 



b. Lip conspicuously calloused or with a callous flange, or 

 having the aperture distorted. Auris. 



b. 1 Aperture ovate, the lip without calluses. 



c. Ovate, the shell dappled, maculate or zigzag striped, 



Plekocheilus. 



c 1 . Oblong, streaked or with a few wide bands; nepionic 



shell rather large and sculptured. Thaumastus. 



a 1 . Shell much depressed, with crater-like umbilicus, subhorizontal 



aperture and continuous flaring peristome. Xenothauma. 



a 2 . Shell ovate, pillar-shaped or Helicoid, plain, banded or streaked, 



the aperture with simple or expanded peristome. Bulimulus. 



(Australasian genera.) 



a. Shell rather thin, Bulimulus-like, the peristome simple. Duct of 



the spermatheca long. Bothriembryon. 



a. Shell auriculoid, the peristome reflexed or expanded, generally 



much thickened and bright colored. Duct of the spermatheca 



short. Placostylus. 



2. Radula with variously specialized teeth, unlike the ordinary 

 Helicid type. Jaw very thin and flexible. (All American.) 



a. Shell ovate or oblong, usually with a peculiar color-pattern of 

 oblique streaks ; the apical whorls sculptured with vertical riblets 

 and finer, lower, spiral striae, sometimes smooth. Rows of teeth 



