F. B. Meek on Acteonide. 87 
pointed and hooked or claw-shaped. Head depressed, subquad- 
rate, truncate and more or less emarginate anteriorly ; provided 
behind with two broad tentacular lobes, which are reflexed upon 
the fore part of the body-whorl when the animal walks. Eyes 
sessile near the middle of the head, at the anterior bases of the 
tentacular lobes. Mantle included within the shell. Branchial 
lume single. Foot oblong, truncated in front, and obtuse be- 
und. Operculum corneous, narrow, subovate and transverse, or 
(in Ringicula) (?) wanting... 
the genera embraced in this family, as above defined, are 
more or less readily divisible into two sub-families, distinguished, 
80 far as has been determined from the examination of the re- 
cent typical genera of each, by differences in the animal as well 
as shell. These differences, looking at the living species only, 
would seem to be quite strongly enough marked to separate these 
gtoups into two distinct families; but when we compare the 
shells of all the various extinct species, they are found to be ap- 
parently so blended together by intermediate forms as to indi- 
cate that they should rather be arranged in different sections of 
the same family, than as distinct families. 
{t seems to be impossible to adopt any linear arrangement of 
the various fossil and recent genera and subgenera of this family, 
that will bring together those most nearly allied. The following 
mode of grouping them, however, will probably as nearly express 
their affinities as can readily be 'g 
I. Subfamily ACTAONIN 2. 
Shell with lip not reflected, or thickened without, generally smooth 
Within ; surface smooth or spirally striate. Animal without peeee ten- 
€$} eyes sessile on the middle of the head at the base of the tentacu- 
lat lobes. Provided with an operculum. 
amt (a). Columella with plaits. Section (5). Columella without plaits. 
m8 Acton: Orbi 
Genus Ovlindeine (More Eiye)—__—-Genus Euconactaeon, (Meek). 
Gubgen, Goniocylindrites, (Meek) Subgen. Conactaon, (Meek 
nus cares (Con. Genus Globiconcha, (d’Orb.). 
‘eon, (Meek s Act«onina, (« "Orb.). 
Subgen. Spiractaon, (Mest) ubgen. Trochacteonina, (Meek). 
€nus  Tornatellea, (Con. ) 
Solidula, (Fischer). 
IL. Subfamily RINGICULINA. 
Shell with lip reflected and thickened without, surface spirally site 
and usuall i | Animal (in Ringicu 
A Y presenting a porcellanous lustre. Ain Feingre 
48 In Actewon, escaping run the lingual teeth are as in Philine and 
$ 3 
The lines drawn across between the names placed in the two columns of each 
etamily, are intended to indicate as near as can he done, the relations between 
Senera and subgenera falling within these two sections. 
