ANCILLARIA. 5 
ANAS’TOMA, or Anostoma, Lam. (From Ava, ana, backwards; 
Sroua, stoma, mouth.) Fam. Colimacea, Lam. A genus of 
land shells, sonamed from the singular circumstance of the last 
whorl taking a sudden turn and reflecting the aperture upwards, 
so as to present it on the same plane with the spire, so that the 
animal must walk with the spire of its shell downwards, resting 
onits foot. In other respects the two-species forming this genus 
resemble the other Helices, and belong to De Ferusac’s division 
Helicodonta. 'TomocErvus is Montfort’s name for this genus. 
A. Depressum, fig. 271, 272. 
ANA’TIFER. Brug. Anatifera,Lam. This name which signifies 
“ Duck-bearing,” has been given to the shells commonly called 
Barnacles,on account of an absurd notion entertained among 
- the ancients, that they enclosed, in an embryo state, the young of 
the Barnacle Duck, the beautiful bunch of cilize, which serve the 
purpose of agitating the water so as to draw in the animalculi for 
food, being taken for the feathers of the future bird. For a 
description of these shells see Pentelasmis, and fig. 34. 
ANATINA. Lam. (That which belongs to a duck.) Fam. Myaria, 
Lam. Pyloridea. Bl. Deser. Thin, transparent, generally ine- 
quivalve, inequilateral, transverse, marine; hinge with a spoon- 
shaped process, containing the cartilage anda small, testaceous, 
moveable appendage connected with the interior of the hinge. 
By this appendage, and the thinness of the shells, this genus may 
be known from Mya. A. rostrata, fig. 69, resembles a duck’s 
bill in form. 
ANATINELLA. Sow. (Diminution of Anatina.) A genus 
so named from its resemblance to Anatina, from which 
it differs, in being destitute of the internal appendage, and 
having no sinus in the palleal impression. Only one species is 
known, which was brought from Ceylon by Dr. Sispaup. A. 
Sibbaldii, fig. 70. 
ANA’TOMUS. Montf. 2, pl. 279. A microscopic shell, appearing 
from the figure to be a Scissurella. 
ANCILLA’RIA. Lam. Ancilla, Lam. (from latin, ahandmaid.) Fam. 
Enroulées, Lam. Angyostomata, Bl. Deser. Smooth, oblong, 
subcylindrical, spire short, not canaliculated ; aperture elongated, 
effuse, emarginated anteriorly; columella tortuous, oblique, 
tumid, truncated. Obs. The Ancillariz are pretty shining shells, 
enveloped almost entirely in the foot of the animal. 
They resemble Oliva, from which they may be distin- 
guished by the sutures of the spire being filled up with 
the shelly enamel, which nearly covers the surface, the whorls in 
Oliva being separated by a distinct canal. Ancilaria may be 
known from Terebellwm, by the tumid varix at the base of the 
columella. The well known Ivory Shell (Hburna glabrata 
Lam.) belongs to this genus, of which a few fossils are 
