IANTHINID.E. 35 



M. Lucaze-Duthiers made interesting observations upon the 

 secretion of the float by lanthinse in captivity (Ann. Sci. Nat., 

 iv, 329, 1865 ; Ann. Mag. Nat. Hist., xvii, 278, 1866); 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 Voyage 

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

 lanthina emits about a teaspoonful of violet liquid, and he 

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

 fish, serves 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, slightly effused at the base, 

 peristome not continuous, the outer lip acute, entire, columella 

 oblique, somewhat sinuous. No operculum. 



Animal like lanthina, provided with a vesicular float. 



The 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 typical group. S. STAMINEA, Hall 

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



Subgenus HOLOPEA, Hall, 1847. 



This palaeozoic group is composed of incongruous elements ; 

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

 dently belongs to Naticidse, a third resembles lanthina. The 

 species are mostly casts, and there appears to be no good reason 

 for retaining the group. Cyclora, Hall, 1845, has been con- 

 sidered synonymous. 



