336 SHELLS AND SHELL-FISH. PART II. 



Achatina Lam. Oblong ; body- whorl ventricose ; sur- 

 face smooth ; spire variable ; outer lip without any 

 lobe. (fig. 23. p. 170.) 



A. marginata Sw. Zool. 111. 1st Series, pi. 30. 



Achatinetta Sw. Small ; sub-trochiform ; spire obtuse ; 

 outer lip with a thickened internal margin. 

 A. pica. Zool. 111. ii. Series, pi. 99. 



LEUCOSTOMA Sw. General shape of the last, but the 

 upper lip has a thick pad at the top, and another 

 over the base ; affinities doubtful. 



L. variegata Sw. (fig. 24. p. 172.) 



CYCLOSTOMA. Aperture circular, and closed by an oper- 

 culum ; the margins of both lips united. 



Cyclophora Montf. Turbinate ; the spire very short, 

 and generally pointed ; umbilicus very large ; aper- 

 ture entire. 



unicarinata. En. M. 461.f. 1. involvula. Sow. Man. f. 304. 



volvula. Ib. f. 5. articulata. Griff. Cuv. 28. f.l. 



lincina. Ib. f. 2. pulchra. Ib. f. 3. 



pulchra. Sow. Gen. f. 2. Madagascariensis. Ib. f. 4. 



ligatum. Ib. f. 4. auricularis. Ib. f. 5. 



Cyclostoma Drap. Spiral ; spire sub-cylindrical and 

 obtuse ; pillar sometimes wanting ; umbilicus small, 

 or closed. 



C. labio. En. Meth. 461. f. 4. 



Cyclotus Guild. Nearly discoid ; pillar none ; spire 

 scarcely raised, and the tip obtuse ; a small siphon 

 at the top part of the aperture. 



planorbuhis. En. M. 461. f. 3. variegatus Sw. Sow. Gen. f. 1. 



Megalomastoma Guild. Cylindrical, resembling Pupa, 

 but has a horny operculum ; spire not thickened ; 

 teeth or fold on the pillar none. (fig. 97. g, h, i.) 



flavula Sw En. Meth. 461. f. 6. brunnea Guild. (fiff.93.g, A,t.) 



HELICINA Lam. Shell turbinate ; outer lip thickened, 

 and reflected ; inner lip thick, and spreading over 

 the umbilicus ; aperture semicircular, or lunate. 



