lANTHINIDiE. 35 



M. Lucaze-Duthiers made interesting observations upon the 

 secretion of tlie float by lanthinne in captivity (Ann. Sci. Nat., 

 iv, 329, 18(55 ; Ann. Mag. Nat. Hist., xvii, 278, IHGC); Mr. Arthur 

 Adams has also given notes on the habits of these animals (Ann. 

 Mag. N. Hist., 3 ser., x, 417). Dr. Ruschenberger, in his Vo^-age 

 around tlie World, p. 21, remarks that when captured, the 

 lanthijia emits about a teaspoonful of violet liquid, and he 

 supposes that this copious discharge, like the inlv of the cuttle- 

 fish, sei'ves to facilitate the escape of the mollusk from its 

 enemies. 



Genus RECLUZIA, Petit, 1853. 



Shell paludiniform, thin, white under a brown epidermis ; whorls 

 ventricose ; aperture obliquely ovate, slightl3' eflTused at the base, 

 ])eristome not continuous, the outer lip acute, entire, columella 

 oblique, somewhat sinuous. No operculum. 



Animal like lanthina, provided with a vesicular float. 



Tlie species inhabit the Arabian Gulf and Pacific Ocean. 



Genus SCALITES, Conrad, 1842. 



Shell turriculated, whorls flattened above, carinated at the 

 shoulder, and convex below; outer lip sinuous ; umbilicus none 

 or very small. S, angulatus, Conr. Silurian. United States. 

 (Struct, and Syst. Conch., t. 67, f. 51.) 



The systematic position given this fossil as well as its sub- 

 genera, is mere guess-work. 



Subgenus Raphistoma, Hall, 1847. 



Shell turbinated, more depressed, with carinated shoulder, and 

 convex below, as in the tj'pical group. S. staminea, Hall 

 (Struct, and Syst. Conch., t. 67, f. 52). 



Subgenus Holopea, Hall, 1847. 



Tliis palreozoic group is composed of incongruous elements; 

 its first species has been referred to Littorinidai, another evi- 

 dently belongs to Naticidoe, a third resembles lanthina. The 

 species are mostl}' casts, and there appears to be no good reason 

 for retaining the group. Cyclora, Hall, 1.845, has been con- 

 sidered s^monymous. 



