378 — Prof. F. M‘Coy on new Species of Fossil Volutes 
Voluta antiscalaris (M‘Coy). 
Ovate, moderately ventricose, rather abruptly attenuated to- 
wards the front ; spire moderately acute, apical angle 65° to 70°, 
of four to five whorls, and a rounded, swollen, smooth, oblique 
nucleus at the tip, of one turn and a half; body-whorl with 
about sixteen to twenty-four angular, slightly sigmoid longitu- 
dinal ribs extending rather less than halfway to the front, narrow 
and sharp in the young, wider and more obtusely angular in 
adults, becoming gradually obsolete im front, each ending in a 
sharp conical tubercle crowning the obtusely angulated shoulder; 
a second row of smaller, pointed, conical tubercles surmounts the 
larger on each whorl; the space between the two rows is deeply 
concave and rather wider than the interval between the correspond- 
ing larger tubercles; the space between the upper row and the 
suture is flattened, nearly horizontal, and about half as wide as 
the space between the two rows, both spaces marked only by the 
coarse lines of growth ; whorls, anterior to the tubercles, crossed 
by deep, narrow, spiral sulci having flat spaces between them 
about equal to half the distance of the longitudinal ribs from 
each other; usually about three of these spiral strize visible on 
each of the whorls of the spire, crossing the longitudinal ridges. 
Pillar-folds slender, widely separated, oblique, three or four, the 
third (or fourth, where it exists) posterior, abruptly smaller than 
the two anterior plaits; outer lip thin, smooth. Length of large 
specimens 2 inches; length of body-whorl 5485, penultimate 
whorl 51,2; ; greatest width 4°, to =3,%. A specimen 8 lines long 
gives all the same proportional measurements. 
A careful comparison of specimens of the true V. scalaris 
(Sow.), from the Middle Eocene beds of the Isle of Wight and 
Barton, will show (what none of the existing figures or descrip- 
tions would) that our species, which I have named V. antiscalaris, 
is not identical, but a most remarkable instance of a representa- 
tive form, distinguished with apparent doubtfulness by a slightly 
longer spire, less ventricose body, and the ribs less twisted at 
their anterior end, but with perfect certamty by the spire, which 
in the European species is sharply pointed (in accordance with 
the genus Volutilites, Swa.) and of eight or nme gradually and 
regularly tapering whorls, the apical two or three smooth ; while 
in the Victorian species it terminates in an obtusely rounded, 
smooth, swollen nucleus or “pullus” of one turn and a half, 
below which are only five sculptured whorls in adult individuals. 
In accordance with the slightly more slender form, the pillar is 
less curved than in the English species, and the plaits slightly 
thinner and more oblique; the number of ribs in a whorl is 
greater (being about fourteen or fifteen in the English species) ; 
