98 GENUS XX. CONUS. 



placed. The first, tliose with the spire nearly tmncate, he 

 calls Truncati, the second Pyriformes, the third Elongati, 

 and the fourth Laxi. 



The animal is small in proportion to the size and weight of 

 the shell ; it is a kind of Snail, and, like all the water species, 

 has only two horns, which are cylindrical ; it has two eyes, 

 one on each horn, not at the tip, but on the exterior side, at 

 about one-sixth part of its length from the point ; it has a 

 breathing tube or windpipe, which projects beyond the shell in 

 length about one-fifth part of the length of the shell (see pi. 5. 

 /. 59); it has a thin horny operculum attached to its foot, with 

 which it closes a part of the aperture, and is of an oval figure; 

 its length is only equal to one-fifth of the length of the aper- 

 ture ; the breadth is about one-half the length (see Adanson, 

 p. 89). 



The terms longitudinal and transverse are too often used 

 indiscriminately in this geims. 



Linnaeus has described 35 species, Gmelin has added 36, and 

 Dr. Turton none. Total, 80. 



M. Adanson has not made any alteration in this genus, bvit 

 makes it the first Avith an operculum, and names it Rouleau. 



Lamarck has not made any alteration ; his description is 

 as follows : 



CoNus. Shell turbinated (like a cone reversed), rolled on 

 itself; the aperture longitudinal, straight, not toothed, 

 efluse at the base (see Conus marmoreus and Mercator, 

 f. 69 and 60). 



