323 PLANAXIN^. 



nid(B, but the presence of a siphon, and a distinct notch 

 at the fore part of the aperture, prevent their being asso- 

 ciated with that group. 



Sub-fam. PLANAXIN^. 



Sides of the foot and operculigerous lobe simple. 

 Operculum ovate, subspiral. 

 Littoral. 



Genus PLANAXIS, Lamarck. 



Shell solid, ovately conical ; spire acuminate ; aperture 

 oblong, with a distinct notch in front ; columellar lip flat- 

 tened, smooth, truncate anteriorly, with a wide callosity 

 at the hind part ; outer lip thickened, grooved internally. 



E.V. P. nigra. Lesson, pi. 34, fig. 2, Operculum, 

 P. sulcata. Born, fig. 2, a, 2, b. Shell, P. sulcata, fig. 

 2, c. 



The animals of this genus are marine and somewhat 

 amphibious in their habits, crawling on the stones near 

 the margins of pools left by the retiring tide ; some of the 

 species affect the vicinity of mangrove swamps, and may 

 be seen adhering to the roots above the surface of the 

 water. 



Species of Planaxis. 



acuta, Krauss. circinata, Less. 



areolata, Less. labiosa, A. Adams. 



atropurpurea, Recluz. lineata, Da Costa. 



brevis, Quoy. lineolata, Gould. 



buccinea, A. Adams. nigra, Lesson. 



buccinoides, Besh. , nigritella, Forbes. 



cingulata, A. Adams. nucleus. Lam. 



