MIOCENE MOLLUSCA AND CRUSTACEA. ets) 
Genus STROMBINA Morch. 
STROMBINA (AMYCLA) LAVIS, 0. Sp. 
Plate xx, Figs. 1-4. 
Shell rather less than a medium size for the genus, consisting of eight 
volutions; spire elevated, apical angle about 30 degrees; volutions slightly 
convex between sutures and smooth, except for the fine lines of growth, 
the last one subangular at the middle and constricted below, to form the 
short beak; aperture narrow, a little oblique, rather more than half as long 
as the entire body whorl as seen on the front; outer lip thickened exter- 
nally, forming a distinct, promiaent ridge on the outside, inside slightly 
thickened, denticulate, having six or eight internal ridges; inner lip slightly 
callous at the upper angle of the aperture; lower channel or canal distinct, 
deep, slightly reflected on the outer basal rim; beak strong, and marked 
externally by from twelve to fifteen close, rounded, spiral ridges. Under 
a magnifier the surface of the volutions show irregular contorted spiral 
lines which are neither quite parallel to the sutures nor to each other, but 
which appear like fine threads placed somewhat irregularly, and broken, 
beneath the enamel of the surface. 
This species does not quite meet the requirements of the genus Strom- 
bina, but still is more distant from those of Amycla, while presenting the 
prevailing features of both genera. The only entire individual seen, the 
one figured, barely exceeds half an inch in total length, and shows a mam- 
illar apex; and is a very neat and beautiful shell; but so far as I can learn 
it has never before been noticed. Another imperfect individual has been 
about five-eighths of an inch long. 
Formation and locality: In the gray micaceous Miocene marls at Jeri-' 
cho, and a single one from Shiloh, N. J. From the collections of the 
National Museum, and a single individual has also been recognized among 
collections from South Carolina in the American Museum of Natural His- 
tory. 
