132 Trans. Acad. Sci. of St. Louis. 
Embryo of nearly five whorls, much higher than wide, more rapidly acumi - 
nate toward tip, the upper two or three small whorls smooth, the lower 
two with rather close-set and more or less oblique longitudinal riblets ; 
species much larger, with relatively less abbreviated whorls aud very 
distinct incised lines of growth, the peripheral carina only slightly 
below the middle of the spire WhOrIS..-++e css ececeerccecesecervesee & 
— The prominent subsutural carina separated from the still stronger per- 
ipheral carina by a concave space having several fine spiral threads, 
this surface being subequal to or only slightly shorter than the interval 
separating the subsutural carina from the peripheral carina of the 
whorl above; embryo large and conspicuous, the riblets strong. Length 
of aspecimen having 8 body whorls, 19 mm.; width, 6mm. Vicksburg 
Oligocene (upper and lower). (= supramirisica and tizis De Greg.) 
cochlearis Con. 
The strong and rather more acutely elevated subsutural carina separated 
from the coarser peripheral carina by a relatively much shorter concave 
space, which is always very much shorter than the interval between the 
subsutural carina and the peripheral keel of the whorl above; sculpture 
otherwise nearly similar, the embryo narrower and with more feebly 
elevated riblets; shell smaller in size and of slightly more slender form. 
Length of a specimen having 6 body whorls, 8.5 mm.; width, 2.7 mm. 
Red Bluff Eocene... 2.cc..e0 sesesscvecncccessvens ++» Subsimilis nu. sp. 
Group II. — Embryo small, obtuse and paucispiral. 
Embryo of nearly two whorls, very broad and obtuse at tip, the lower part 
gradually acquiring some feeble and irregular longitudinal riblets; 
shell moderately stout, attaining rather large size and thicker in sub- 
stance, the lines of growth being conspicuously excavated; spiral 
whorls each with a strong subsutural and a still stronger and 
thicker submedian spiral carina, the concavity between them gradually 
acquiring one or two fine spiral threads and the space below the subme- 
dian a fine raised line which on the larger whorls gradually becomes a 
carina equal in size to the subsutural. Length of a specimen of 
about 9 body whorls, 27 mm.; width, 7.5mm. Lower Miocene of Alum 
Bluff, Fla. 20020 ccce vecwicenescccacsescsee seonssccscess! DRETOUL GUppy 
Similar to the preceding, but much more slender in form and thinner in 
substance, the embryo still smaller but rather less obtuse, of scarcely 
more than a single whorl, the riblets not visible in specimens at hand. 
Length of a specimenof 11 body whorls, 23.5 mm.; width, 6 mm. Caloos- 
ahatchie Pliocene of Shell Creek, Fla.........eeeee++eeeee.albida Perry 
I have not seen the types of barretti and albida, but assume 
that the West Florida Miocene species, described above, is 
identical with the former, as it appears to pertain to the same 
geological horizon, and adopt Dr. Dall’s identification for 
albida. The latter author has recently (Trans. Wag. Inst., 
Vol. 3, p. 28) confused these two species with the widely dif- 
ferent cochlearis of Conrad. 
