66 GENERA OF SHELLS. 



B. ovatus, hsemastomus, gallina, sultana, zigzag, undataSy 

 Richii, inversus, citrinus, sultanus, Pythogaster, ovoideus, 

 interruptus, Peruvianus, Favannii, Kanibeul, calcareus, 

 decollatus, Lyonetianus, inflatus, radiatus, fragilis, Guadalup- 

 ensis, Mexicanus, multifasciatus, Bengalensis, Caribaeo- 

 rum, octonus, terebraster, articulatus, acutus, ventricosus, 

 montanus, Iiordaceus, lubricus, — multilatus, multilineatus. 



AcHATiNA. Shell ovate or oblong ; aper- 

 ture entire, longer than broad ; lip sharp, 

 never reflected. Columella smooth, truncated 

 at base. 



This genus is well distinguished from the fornner by 

 the right margin being never reflected, and by wanting 

 that on the left ; the columella being always naked, 

 very smooth, and truncated at the base. 



(a.) Last 2chorl ventricose, not depressed. 



A. perdrix, zebra, immaculata, purpurea, acuta, bicarinata, 

 mauritiana, castanea, ustulata, vexiilum, virginea, Priamus. 



(b.) Last ivhorl depressed or attenuated towards the base. 



A. glans. Peruviana, albo-lineata, fusco-lineala, fulminea, 

 folliculus, acicula — solida, 



SucciNEA. Shell ovate or ovate conic ; aper- 

 ture ample, entire, longer than broad; lip 

 acute, not reflexed, uniting inferiorly with the 

 smooth, thin, sharp columella. No operculum. 



The succinese live habitually on land, near water, 

 which they occasionally frequent. They are distin- 

 guished from the bulimus by the right margin being 

 never reflected, and from the lymnaea by their colu- 

 mella being free from folds. 



S. cucullata, amphibia, oblonga — ovalis, campestris. 



