356 NASSIDiE. 



Genus II. COLUMBEL'LA^ Lamarck. PI. YI. f. 5. 



Body more extended than in the last genus : pallial tube 

 very long and flexible : tentacles short and cylindrical : eyes on 

 the outer base of the tentacles : foot long and thick, sometimes 

 cloven at the extremity, but without any caudal processes : 

 [odontopliore; rhachis crescentic, laminar, bent forward (?); 

 uncinus having a double hook at the point, and furnished with 

 a round wing-like lobe before the base. (Loven.)] 



Shell varying in thickness : mouth contracted and narrow : 

 outer lip slightly sinuated on the upper part : inyier lip not 

 expanded, nor thick : pillar having a single fold at the base : 

 canal deeply notched : operculum horny, roundish-oval, plain- 

 edged ; nucleus rounded, and obscurely concentric, placed near 

 the base. 



This connects the Nassida with the Pleurotomatidce. 

 "We have but one or two species of Columbella, although 

 several inhabit the coasts of North America. Two species 

 (C. rustica and C. minor) are Mediterranean. 



De Montfort capriciously changed the generic name 

 to Columbus. 



A. Outer Hp thickened and furrowed inside ; apex of the spire 

 regularly nipple- shaped. 



]. Columbella HALiyE'ETif, Jeffreys. 



Body whitish, delicately suffused with fleshcolour : pallial 

 tube cylindrical, broader and expanded at the orifice, which is 

 plain- edged ; when the animal crawls, this part projects in 

 front, and is straight, and nearly as long as the shell ; when 

 it is placed on its back the tube is coiled round and (as if un- 

 easily) twisted about from side to side : anus at the upper 

 corner of the mouth of the shell, on the outside ; I frequently 

 observed fa3cal pellets expelled from it : tentacles short, cylin- 

 drical, close together at their base, and diverging outwards ; 

 tips blunt : eijes small, black, and globular, at the outer base 



* Diminutive of cohtmba, a dove. 



t From the yacht ' Osprey,' by means of which tliis interesting species 

 was discovered. 



