Ancillarina
"Testa angusta, perlonga: spira brevissima, detecta. - Anfractus ultimus perlongus, antice transverse et oblique uni-sulcatus. - Os postice angustum, antice dilatatum; labrum sinistrum ad sulcum transversum uni-dentatum (in illaesis); labrum dexterum ultra os parum et regulariter productum. postice callosum: canaliculus posticus oris latus, parum profundus, detectus, marginibus obtusis. - Columella laxe contorta, medio parum excavata, ab apice spirae ad apicem oris plicata et silicata: plicae quatuor, subaequales, axi testae valde obliquae; sulcus posticus latus, profundus et ipse valde obliquus.".
Type species by subsequent designation (Palmer, 1937): Ancilla canalifera Lamarck, 1803.
A group of species known from the Eocene to Miocene. The genus is documented from western Europe, Indonesia, Colombia, Peru and southern California, USA.
Although it usually is considered to belong to the Ancillariinae, its true affinities rather seem to be with the Agaroniinae.
Type species is Ancilla canalifera Lamarck, 1803, a common species in Eocene deposits of France and England.