PRATICOLELLA. 67 



develop and hatch within the uterus, the young snails consume their 

 egg-shells, using the lime for shell-building; they attain a growth of 

 about two whorls or more before birth. In other species this pro- 

 longation of the antenatal period has not been established, and hard- 

 shelled eggs are brought forth. 



Species of Zaphysema. 



Z. macmurrayi C. B. Ad., v, 7. Z. tumida Pfr., v, 8. 

 Z. buddiaua C. B. Ad., v, 7. tmiicata C. B. Ad. 



Z. muuda C. B. Ad., v, 9. Z. tenerrima C. B. Ad., v, 8. 



Z. columellata C. B. Ad. v, 9. 



Genus PRATICOLELLA v. Martens, 1892. 



Praticola STREBEL & Pfeffer, Beitr. Mex. Land- und Su'ssw. 

 Conch, iv, p. 38, 1880, type P. ocampi. Not Praticola Swains., 

 1837.Praticolella v. MART., Biol. Centr. Arner., Moll., p. 138. Dor- 

 casia BINNEY, Terr. Moll, v, p. 346, not of Gray. See for anatomy, 

 W. G. BINNEY, I. c. ; SEMPER, Phil. Archip. p. 246 ; STREBEL & 

 PFEFFER, I. c. 



Shell of the ordinary Helix shape; narrowly umbilicated, globose, 

 shining, opaque white or yellowish with translucent corneous and 

 brownish spiral bands, the most constant band supraperipheral in 

 position. Aperture lunate-rounded, slightly oblique, lip narrowly 

 reflexed, dilated at the columellar insertion, sometimes thickened 

 within. Type P. ampla Pfr. (see pi. 20, figs. 26, 27, P. griseola ; pi. 



20, fig. 28, P. berlandieriana ; pi. 20, figs. 29, 30, 31, P. flavescens). 

 Mantle having both right and left body-lappets; sole indistinctly 



tripartite, the central area not sharply separated from the sides, but 

 darker colored (in spirit). 



Genitalia (pi. 21, figs. 1-4, P. ocampi=ampla) Female organs as 

 in Polygyra, without dart sack, mucus glands or other accessory organs ; 

 spermatheca oval, its duct simple and very short. Penis large, the 

 vas deferens inserted at its apex ; retractor trifid, one branch inserted 

 at apex and one at middle of penis, with a small branch to vas defer- 

 ens (fig. 2). Cavity of penis containing a tongue shaped papilla (pi. 



21, fig. 3), inserted near apex of cavity ; a fleshy 'ridge arising at the 

 insertion of the vas deferens runs nearly to the base of penis. At 

 the lower third of the penis is inserted a large, club-shaped appendix, 



