34<6 



SHELLS AND SHELL-FISH. PART II. 



Naticaria Sw.* Oval ; convex above ; 



umbilicus small, open, placed very 



near the top of the aperture ; inner 



lip reflected^ small, {^fig. 107.) 



N. melanostoma. Mart, 189. f. 1926, 1927. 

 cancellata Sw. lb. 189. f. 1939. 

 bifasciata. GrifF. Cuv. 1. f. 2. 



Lacuna Turton. Turbinate ; thin ; spire very small, 

 of two whorls ; the general shape 

 is like JVatica, but the base is 

 contracted; umbilicus close to 

 the top of the aperture, with a 

 groove running on the margin of the pillar, which is 

 oblique ; operculum horny ; aperture effuse, semicir- 

 cular. (Jig. 108.) 



L. ^aWidula Turton. (fig. 108.) 



Leucotis Sw. Form of the shell intermediate between 

 Sigaretus and Lacuna ; but there is no pillar ; umbi- 

 licus large,, pervious ; inner lip thin^ slightly reflected 

 at the top I surface sculptured. 



Sigaretus cancellatus. Lam. Sys. vi. 2. p. 207. Chem. 

 165. f. 1596. 1597, 



SuB-FAM. ? NERITINiE. Nerits. 



Globose ; spire very small ; pillar oblique ; inner lip 

 very broad, depressed, more or less flattened, and gene- 

 rally toothed ; aperture semicircular. 



Nerita Linn, Shell solid ; inner lip toothed or gra- 

 nulated. 



N. peloronta. Mart. 192. f. pollta. Mart. 193. f. 2002, 

 1977—1981. 2003. 



Neritopsis Gray. Aperture sub-orbicular ; pillar lip 

 thickened above and below, with a wide notch in the 

 middle, f 



N. granosa. Sow. Man. f. 331. 



♦ These are probably aberrant species, connecting Sigaretus with Ma- 

 millaria; but, until the whole are better understood, I think it advisable 

 they should be kept distinct. 



t Apparently related, by the shell, to Leucotis. 



