225 
ANCILLA, Delamarck. 
Voluta, Linn. 
ee — 
Gen. Cuar. Univalve, spiral, oblong, subeylin- 
drical; spire short, without a canal; aperture 
longitudinal, expanded, slightly emarginate at 
the base; a tumid appendage, or varix, round 
the base of the columella. 
EEE EE EE 
"Due last whorl is much larger than the others, whence the 
aperture is often equal in length to half the shell. The 
varix is frequently plaited, and the inner lip is, in several 
species, continued farther over the spire than the outer ; in 
some it even reaches oyer the line of separation of the whorl 
before it. 
After the Genus Oliva had been defined to have a canal 
between the whorl on the spire, it became necessary to se- 
parate such analogous shells as were destitute of that mark, 
into another Genus, but I fear there are intermediate ones, 
which will render that character ambiguous, such as my 
Ancilla turritella, which, although it has no canal, has a 
concave space approaching one. 
4 
ANCILLA aveniformis. 
TAB. XCIX.—Middle figures. 
Spec. Cuar. Oval, elongated, smooth; spire long, 
acute, varix with two plaits; extension of the 
imer lip short. Aperture little more than half 
the length of the shell; inner lip extended over 
about one-third of the exposed part of eacli 
whorl; surface shining. 
———eee 
Orxz of the few shells from Barton not figured by Brander; 
it differs from Delamarck’s A. buccinoides, in having a 
