Casey — Notes on the Pleurotomidae. 141 
similar to that characterizing Scodinella, and the aperture, 
canal and embryo are of corresponding form, but the anal 
sinus is wholly different in form and position and the outer 
lip is not advanced and arcuately lobed. They have occurred 
thus far only in the Lower Claiborne Eocene of Texas, and 
those before me may be readily recognized as follows : — 
Broadly rhomboidal in outline, the spire evenly conical, the aperture and 
very short canal combined constituting nearly half the entire length; 
lyrae of the body whorl below the periphery very coarse and widely 
spaced, alternating with single fine raised lines; columellar folds two 
or three in number. Length of a specimen of 5 body whorls, 11.5 mm. ; 
width, 4 mm...........-4 = hod door Asobse seeeeee-+- Crassiplicata Gabb 
Narrower, the spire subventricose or narrowing more rapidly toward the 
apex; aperture very much less than half the entire length............ 2 
2— Larger species, with a nodulose subsutural spiral and a similar but 
broader duplex peripheral spiral, the two separated by a concave sur- 
face which is rather longer than the subsutural collar, and aaving a 
fine nodulose thread at its middle; another similar fine thread is very 
close to the lower margin of the large peripheral spiral, and, below 
this on the body whorl, the lyrae are equal, granose and moderately 
widely spaced, the lines of growth fine, deep and close-set, appearing 
between the lyrae but independent of the nodules; columellar folds 
about threeinnumber. Lengthof a specimen of 5 body whorls, 9 mm.; 
Width, 2.8 MM... .ccecrece cece cece cceecccccescoveess-COnradiana Ald. 
Smaller species, with numerous very close-set spirals of coarse nodules, 
the subsutural gradually splitting into two finer spirals on the larger 
whorls, the concave space below the collar short and with fine irregu- 
lar thread or threads; spirals below the peripheral alternating in size 
to the aperture, then equal and almost in mutual contact to the base of 
the shell; nodules in longitudinal lines from one lyra to the next, 
giving a closely costulate appearance which does not exist in the pre- 
ceding species; columella with two large rounded and very approximate 
folds at the middle, the lower more oblique than the upper; embryo of 
about four whorls, higher than wide; aperture and canal relatively 
longer than in conradiana. Length of a specimen of 3 body whorls, 
3.9 mm.; Width, 1.75 MM. ...ce see scccsesccecce voce secs parvula n. sp. 
These species are all well represented in the cabinet of Mr. 
Aldrich, to whom Iam indebted for the material at hand. 
Trypanotoma Coss. 
A very distinct genus, apparently confined to the middle 
Eocene faunas of the southern United States and character- 
ized by the comparatively small size and slender form of the 
