ANCILLIN.E, 147 



Sub-fam. ANCILLIN^. 



Head concealed ; eyes none ; tentacles rudimentary. 

 Mantle without a tapering lobe in front. Foot volumi- 

 nous, bifid behind, shield grooved on the upper surface, 

 side-lobes not much produced. 



Operculum smallj ovate, acute, sometimes entirely 

 wanting. 



Shell usually polished ; whorls smooth ; aperture efTuse? 

 with the front part of the columella variously grooved and 

 twisted. 



Genus DIPSACCUS, Klein. 



Shell fusiformly cylindrical, polished, solid, generally 

 deeply umbilicated; spire elevated, suture covered with 

 enamel ; aperture oval, elongated : inner lip tortuous ; 

 outer lip acute, with a slight tooth on the fore part. 



Ex. D. glabratus, Linnceus, pi. 15, fig. 6. 



In the Dipsaccus of Klein, as restricted, there are four 

 species, distinguished by the deep umbiUcus and chan- 

 nelled columella, which are owing to certain peculiarities 

 of the animal not yet known. Lamarck included the D. 

 glabratus among the species of his genus Eburna, which 

 belongs to another group. 



Species of Dipsaccus. 



balteatus, Sow. glabratus, Linn. 



ciugulatus, Sow, niveus, Swains. 



