PART II. 



LUCERXIN^. 329 



Discodoma Sw. Teeth none ; aperture angulated ; 

 the inner lip nearly obsolete, the outer only slightly 

 thickened ; margin carinated. 

 albilabris. Chem. 125,f. 1090, Gualteriana. Chem, 5. vig. 



1091. 44. a—c. 



inflata. lb. 126. f. 1 100, 1. marginata. lb. 102. f. 1095. 

 gigas. lb. f. 2044, 5. angistoma. lb. 125. f. 1092. 



Lucerna Humph. Outer lip with teeth, either mar- 

 ginal or internal ; the outer lip thick and reflected ; 

 circumference carinated. 

 acutissima. Zool. 111. ^ ii. fasciata Guild. Bow. Conch. 



pi. 96.* ' 7. f. 23. 



lanx. En. Meth. 462. f. 2. fulgurata Sow.\ 

 lychnuchus. Ch. 126. f. 1108. sinuata. Chem. 126. f. 1110 



— 1102. (Aberrant.) 



Anastoma Lam. Aperture turned upwards, furnished 

 with plaited teeth on both sides. 



A. depressa. Chem. 109. f. 919, 920. 



LucAdula Sw. Aperture transverse ; both lips much 

 thickened and united ; the outer with marginal obso- 

 lete teeth at the base ; umbilicus closed. 



' Barbadensis Lam. No. 49. p. 78. Fer. Moll. pi. 47. 2, 3, 4. 



LucERNELLA Sw. Teeth on both sides of the aper- 

 ture ; surface regularly and distinctly striated. Cir- 

 cumference convex.:}: 



Polydontes Montf. Aperture nearly circular, sur- 

 rounded with obtuse tubercular teeth. 

 P. imperator. Bowdich, Elem. of Conch, pi. 7. f. 21. 



Lyrostoma Sw. Aperture lyre-shaped, very contracted 

 near the body-whorl, widened beyond. 



L. labyrintha. Chem. pi. 208. f. 2048. Lam. p. 46. 



* The original figure of the shell and animal given in Zool. 111. is 

 copied by Feriissac, Guerin, and numerous others, but so badly, that the 

 shell appears to be a totally different species. 



f Mr. Sowerby has published a very beautiful detached plate of this 

 species, first described by himself. 



X Some slight variation has been made in the arrangement of this group 

 from that previously stated at p. 193. Cyclodoma is here united to Lucer- 

 nella, and the new sub-genus Lyriostoma proposed. 



