46malacozoa. gasteropoda, pulmobranchiata.terrestria, 



wrinkled, shining, transparent, yellowish-brown, with 

 the suture margin planulate, part of the last turn beneath 

 somewhat opaque and whitish, umbilicus rather large 

 and deep. Allium, garlic. Allidrius, smelling of 

 garlic. 



6. Zonites radidtulus. — Shell depressed, very slightly 

 convex above, regularly striate, transparent, glossy, pale 

 greenish-grey, of three-and-a-half whorls, which are flat- 

 tened at the suture margin, with the strise more distinct 

 there, umbilicus large and deep. Radidtulus, having 

 small rays. 



7. Zonites purus. — Shell flattened, somewhat convex 

 above, wrinkled or striate, transparent, moderately glossy, 

 greenish-white, of four whorls, which are a little convex 

 and incurved at the suture margin, umbilicus rather 

 large and deep. Purus, clean or clear. 



8. Zonites crystdllinus. — Shell flattened, very slightly 

 convex above, extremely thin, transparent, shining, green- 

 ish-white, of five or six whorls, which are slightly flat- 

 tened at the suture margin, and faintly striato-rugose, 

 umbilicus deep, of moderate width. Crystdllinus, clear 

 like crystal, or glass. 



9 . Zonites fuscus. — Shell rather convex, extremely thin, 

 flexible, the turns striato-sulcate. Fuscus, brown or 

 dusky. 



Genus 4. Vitrina. Animal with a linguiform process 

 extending backwards over the shell, on the right side. 

 Shell spiral, of few turns, semiorbicular, imperforate, 

 extremely thin, transparent ; the last turn disproportion- 

 ately large ; the aperture roundish, with the margin very 

 thin. Vitrum, glass. Draparnaud. 



1 . Vitrina pellucida. — Shell ovato-orbicular, consider- 

 ably depressed, very thin, brittle, glossy, pale apple-green, 

 or hyaline ; with the aperture very large, roundish, sub- 

 lunate. Pellucidus, permeable to light. 



Genus 5. Succinea. — Shell oval or oblong, imperforate, 

 very thin, with a short spire ; the aperture very large, 

 obovate or oblong, with the margin thin, and disunited 

 behind. Succinum, amber, Draparnaud, 



