204 THE CHICAGO ACADEMY OF SCIENCES. 



simple, or armed with folds or denticles; color horn, with vari- 

 ous zigzag, reddish flames. 



Animal: With a well-developed caudal mucus gland and 

 supra-pedal furrows. Genitalia lacking accessory appendages. 

 Jaw ribbed or striated. Central tooth quadrate, with side 

 cusps and distinct cutting points; lateral teeth similar; mar- 

 ginal teeth low, wide, crowded, with one or more cusps, "the 

 outer cusp never elevated on middle cusp."* 



Subfamily Endodontinae. 



"Jaw soldered into one piece." (Pilsbry.) 



GENUS PYRAMIDULA Fitzinger, 1833. 



Pyramidula FITZINGER, Syst. Verzeicb, 1833. 



Discus FITZINGER, Syst. Verzeich, 1833. 



Patula HELD, Isis, 1837. 



Anguispira MORSE, Journ. Port. Soc., Vol. I, p. 11, fig. 15, 1864. 



"Shell: Openly umbilicated, varying in contour from flat- 

 tened and disk-like to conoidal. Generally opaque, often rib- 

 striate. Unicolored, spirally banded or flammulate. Whorls 

 subcylindrical or keeled, the apex generally smooth. Aperture 

 rounded-lunate; lip simple and thin." 



"Animal: Having the sole undivided; lateral margin of the 

 foot with a distinct border bounded by a groove, the grooves meet- 

 ing above the tail. No caudal mucus pore. Eye-peduncles 

 long and slender. Genital system lacking accessory organs; 

 vas deferens and retractor muscle inserted near or at the apex 

 of the penis; duct of the spermatheca very long; hermaphro- 

 dite duct very long, but shortened by its extreme convolution. 

 Jaw arcuate, its component laminae generally compactly sol- 

 dered, and indicated only by fine striae which diverge slightly 

 from the middle. Radula (r) having only the mesocones de- 

 veloped upon central or inner lateral teeth, or (2) having the 

 centrals tricuspid, laterals bicuspid lacking the ectocones, mar- 

 ginal teeth similar but with short basal-plates; this being the 

 usual form. In some species the marginal teeth are multicus- 

 pid by the splitting of their ectocones." (Pilsbry.)f 



KEY TO SPECIES OF PYRAMIDULA AND HELICODISCUS. 



A. Shell large. 



a. Subglobose, periphery rounded, striae very fine, last 



whorls with two spiral, reddish bands solitaria 



*Pilsbry, The Nautilus, Vol. IX, p. no. 

 tGuide to Study of Helices, pp. 42, 48, 49. 



