168 Trans. Acad. Sci. of St. Louis. 
sculpture, having the aperture oblique, narrowly oval, nearly 
half as long as the shell and completely undifferentiated from 
the extremely short canal. The anal sinus is small but distinct 
and abruptly formed; it is but slightly everted from the axial 
line of the aperture, though separated from the suture by a 
thickened callus. The outer lip is not dilated and is non- 
plicate. Columella with about twojbroadly tumid oblique and 
approximate folds at the middle. The spire is half as long as 
the shell, with its outline even in profile from whorl to whorl, 
and without break due to individual convexity of the whorls, 
the side profile of each whorl very feebly arcuate, the sutural 
breaks in the curve of profile narrow; each whorl with about 
three very broad approximate spiral lyrae, forming moderately 
elevated tubercles or nodules on the numerous approximate 
ribs; pillar not differentiated, the base of the shell obconic. 
The embryo is smooth, of between one and two whorls, very 
broadly and obliquely obtuse at apex in profile, the summit 
concave, the nucleus extremely small. Body whorls three to 
four in number. The two species in my cabinet are the 
following: — 
Shell white, variegated irregularly with dark brown; longitudinal ribs 
separated by much less than, their own widths and very numerous, 
some twenty in number. Length, 4.0 mm.; width, 1.6 mm. 
multigranosa Smith 
Shell still smaller, clear and pale straw color throughout, the ribs separated 
by fully their own widths and about fifteen in number, much more nearly 
obliterated between the strong spirals than the latter are between the 
ribs. Length of a specimen of 3 body whorls, 2.9 mm.; width, 1.8 mm. 
insolens n. sp. 
The general outline of the shell in this genus is not unre- 
mindful of Mitromorpha, but it differs in having a distinct 
anal sinus. Probably many other species will be discovered, 
hitherto overlooked because of their minute size. 
TARANINI. 
This tribe, though very limited in scope, is altogether iso- 
lated and differs from the preceding not only in facies, but 
in some important structural features, the most important 
