EUTROPIL\^. 389 



Sub-fam. EUTROPIIN.E. 



Operculum ovate, with a thick, solid, smooth, cal- 

 careous coat. 



Shell ovately-oblong, porcellanous, polished, the last 

 whorl rounded and produced at the base ; aperture ovate. 



Genus EUTROPIA, Humphrey. 



Operculum stony, thick, ovate, smooth. 



Shell ovately-oblong ; spire elevated, whorls smooth, 

 poHshed ; aperture oval ; columella smooth, flattened ; 

 outer lip thin, simple, acute. 



Syn. Phasianus, Montf. Phasianella, Lam. Ortho- 

 pncea, Gistel. 



Ex. E. Tritonis, Chemnitz, pi. 42, fig. 5. Oper- 

 culum, E. Tritonis, fig. 5, a, 5, h. Shell, E. Tritonis, 

 fig. 5, c. 



When the animals of this genus crawl, the foot 

 appears to be divided longitudinally into halves which 

 advance alternately; when the right side moves, the 

 left remains stationary, and when this in turn is carried 

 forward, the other half serves as a point of support. 

 MM. Audouin and Milne Edwards have observed that 

 E. pullus eyihxhit?, the same mode of progression, which 

 they compare to the amble or canter of a horse. In 

 Eutropia proper the tentacles are ciliated, the head- 

 lobes fringed, and the sides of the foot furnished with 

 three cirrhi. In the smaller species, forming the Tri- 

 coUa of Ivisso, the head-lobes appear to be wanting. 



