OF SOUTHERN INDIA. 403 
doubt that it belongs to this family. It is much more probable that the shell 
is a Marinula (Avricurtpm), which only differs by usually having the posterior 
fold the strongest. That the shell occurs in marine beds in itself proves nothing, 
for most of the present “Auvrrovzrp# live on the sea-shore, often between tide 
marks, and the dead shells are found everywhere with truly marine species. I 
have myself dredged a dead shell of Pedipes in about six fathoms of water in the 
Aden harbour with living Ringicule, Ancille, Turritelle and others. 
10. Trochacteon, Meck, 1863 (Acte@onella, d’Orbigny and auctorum ex parte, 
Am. Journ. se. and arts, XX XV, p. 89). Shell turbinate, more or less involute, last 
whorl usually higher than the spire, with a narrow flattened and solid edge along 
the suture; aperture semi-effuse, anteriorly rounded, inner lip thickened, espe- 
cially in front, and provided with three oblique folds. 
It would no doubt have been preferable to retain the name Acteonella for 
those involute forms, the first of which, Act. Renauxiana, was figured and described 
by d’Orbigny under that genus, as stated in my revision of the Gosau-Gastropoda, 
published in 1865 (Sitz. Akad., Wien, LII, p. 515). When writing those notes 
in 1864 I was not in possession of the January 1863 number of the American 
Journal, and proposed consequently for the convolute forms, like Act. levis, for 
which Meek has retained d’Orbigny’s name <Act@onella, that of Volvulina (vide 
ibidem, p. 519) ; as, however, Meek’s proposition has priority before my own I have 
here accepted it. The sub-generic name Spiracteon, which Meek proposes for cer- 
tain species with a more conical spire, has, however, no foundation whatever. It 
will be seen from my notes on the Gosau-Gastropoda (loc. cit., p. 517) that the Act. 
obtusa, Zek., which Meek quotes as one of the species of Spiracte@on, is in reality 
only a variety of Act. gigantea, which he places in Trochacte@on, 
b. Sub-family,—APLUSTRIN A. 
The animals of this sub-family agree in general form and dentition with the 
former, but the frontal disk usually has large appendages, folded over the back 
of the shell; the mantle margin is also somewhat more developed, than in the 
ACTZONIN# ; an operculum is not known. 
The shells in general form, texture and ornamentation resemble those of the 
former sub-family; the spire is usually short, the last whorl inflated, the aperture 
anteriorly distinctly effuse, the columella somewhat thickened, rarely twisted, but 
always anteriorly truncated. 
The species are first known from the jurassic deposits, and continue in small 
number to be noticed through all the successive formations ; they appear to have 
been in former times rather rare shells, and the recent species are only found very 
locally distributed. 
11. Htalonia, Deshayes, 1864 (Paris foss., 2me. ed., p. 605). Shell ovate, 
attenuated on both ends, spire elevated; aperture narrow and high, anteriorly 
truneated, columella thick, twisted in the middle with an obscure fold. The two 
