178 THE CHICAGO ACADEMY OF SCIENCES. 
Distribution: Europe and America. 
KEY TO SPECIES OF VITREA. 
A. Shell large, exceeding 10 mill. in diameter; widely umbili- 
cated; aperture much expanded.................draparnaldi 
B. Shell small, less than 10 mill. in diameter. 
a. : Shell umbilicated o.'> 4.4. cn a eee ene hans fy ee hammonis 
b. Shell imperforate, but indented about the umbilical re- 
1) (Peep Peter gem tnbrens  pe SW, 208, ol See ae So Nts” inden tata 
66. Vitrea draparnaldi Beck, pl. xxviii, fig. 5. 
flelix draparnaldi BECK, Index Moll., p. 6, 1837. 
Shell: Of good size, depressed, thin, but solid when adult, 
pellucid, umbilicated;surface smooth, polished, shining, marked 
by numerous very fine, oblique lines of growth; color greenish- — 
horn, sometimes lighter; periphery rounded; sutures very dee ply 
impressed; whorls five to fiveand one-half,rounded, convex very 
regularly increasing, the upper surface flatly convex; aperture 
a little oblique, transverse, not dilated, the transverse diameter 
much longer than the height; peristome simple, thickened, ter- 
minations widely separated; umbilicus round, broad, deep, ex- 
hibiting a few of the volutions; base of shell rounded, thick- 
ened within by a deposit of bluish-white testaceous matter. 
Greater diam., 15.50; lesser, 15.00; height, 8.00; umbilicus diam., 2.75 mill. 
(10108.) ' 
Greater diam., 7.00; lesser, 5.75; height, 3.00; umbilicus diam., 1.50 mill. 
(10148. ) 
Animal: With a long, narrow foot, long and slender eye- 
peduncles, and short tentacles; color slaty-blue, indigo-blue or 
blackish above, darker on head, eye-peduncles and neck; collar 
greenish; animal much lighter beneath; a locomotive disk pres- 
ent and pedal grooves meeting above the tail, much as de- 
scribed in V. fuliginosa. Heart situated as in Zonztoides arboreus, 
pulsations regular, numbering as follows: 46, 51, 52, 57, 61, 71, 
84. In some specimens the beats were quite irregular and 
may be represented by the following diagram (Fig 34) in which 
the dash represents the interval between each heart-beat: 
eccemeness 6 tenes © ape 8 eee Oe Oe 0 as OT SE OS Re ES 
Fic. 34, 
Diagram showing heart-beats of VITREA DRAPARNALDI Beck. 
The smallest number of beats is when the animal is con- 
tracted,and the largest when extended. pair of foot 25.50 
mill., width 3.00 when fully extended. 
