- . ro a 
266 THE CHICAGO ACADEMY OF SCIENCES. 
inflated; color light or dark horn; surface shining, covered 
with numerous crowded, fine lines of growth, which can 
scarcely be discerned on the apex; whorls five, somewhat 
shouldered in some forms, the shoulder being near the suture; 
the last whorl is very large, half the length of the entire shell; 
each whorl is double the size of the one preceding; spire 
sharply-conical; sutures very deeply indented; aperture elon- 
gately ovate, somewhat expanded; peristome thin, acute; col- 
umella thickened by a testaceous deposit, and bearing a heavy 
plait across the middle; the columella is reflected at the lower 
end, the reflection almost covering the umbilicus, which is 
narrowly open; the umbilical region is somewhat indented. 
The surface is sometimes broken up by coarse, spiral semi- 
ridges into facets, forming a somewhat reticulated surface. 
Length, 12.00; dicate 6.00; aperture length, 6.00; width, 3.00 wali (8457.) 
“12.00; 5.25; 6.00; “ 3,50 (8457.) 
“ 40.00; “ 400; « “ 550; “ 250 “ (8457.) 
« 975; « 500; « “ 450; 29.50 “  (8457.) 
«1300; “ 5.95; “750; “ 400 “ (8468) 
Animal (Fig. 84): With a very small, more or less oblong 
foot, when viewed from the base, the anterior and posterior 
borders rounded; color dark gray or blackish, lighter below; 
Fie. 84. 
Animal of LIMN2ZA DESIDIOSA Say. (Binney, Fig. 25.) 
the whole surface is dotted with whitish, which is specially 
noticeable about the eyes; tentacles triangular, flat, short, more 
or less transparent; the black eyes are placed on prominences 
at the inner base of the tentacles; respiratory orifice on the 
right side, near the angle of the peristome and body whorl. 
Length of foot 5.00, width 3.00 mill. The heart is situated near 
the umbilicus and the pulsations are very rapid; the writer 
counted one hundred and fifty to one hundred and fifty-five 
per minute. 
Jaw: Asusual. 
Radula formula: 32+3+4+1+4+3+2° (46—1—46); cen- 
tral tooth as usual; lateral teeth with a subquadrate base of 
attachment, the reflection very broad, bicuspid, the inner cusp 
Ma hs eee ee 
