24 
species has always a white base, being immaculate beneath the 
inferior baud. 
H. INORNATA. — Shell subglobose, pale yellowish horn color, 
polished; whorls five, rounded, wrin^cled; spire convex; suture 
not deeply impressed ; umbilicus small, profound ; aperture wide, 
at the junction of the labia with the penultimate whorl shorter 
than the width of the mouth ; labrum simple. 
Inhabits Pennsylvania. Greatest width less than seven-tenths 
of an inch. 
This species has a strong resemblance to H. ligera, but in addi- 
tion to its superior magnitude, its aperture is proportionally wider, 
a character which of course gives the whorls a greater breadth ; 
the whorls are also fewer in number, and the distance between the 
terminations of the lips is very perceptibly less than the width of 
the aperture, the reverse of which obtains in the ligera. 
IT. INDENTATA. — Shell depressed, pellucid, highly polished ; 
whorls four, with regular, distant, subequidistant, impressed lines 
across, of which there are about twenty-eight to the body whorl, 
all extending to the base; suture not deeply indented; aperture 
rather large ; labrum simple, terminating at its inferior extremity 
at the centre of the base of the shell; umbilicus none, but the. 
umbilical region is deeply indented. 
Greatest breadth one-fifth of an inch. Animal blued-black, 
immaculate. 
My cabinet and that of Mr. Wm. Hyde. Several specimens 
occurred at Harrigate, the country residence of my friend Mr. 
Jacob Gilliams, adhering to stones and logs in moist places. Mr. 
Hyde obtained many individuals in New Jei’sey. It may readily 
be mistaken for H. arborea, but it is destitute of the umbilicus, 
instead of which there is an indented centre to the base, in which 
the labrum terminates. The spire is very much depressed, and 
the surface prettily radiated by distant impressed lines, the inter- 
stices being perfectly smooth. 
H. LINEATA. — (Yol. i., p. 18.) On examination of several in- 
dividuals of this species, I have ascertained that a character exists 
in this species that was altogether wanting in the specimen from 
which I drew out the description published in the first volume of 
this work. As the shell is somewhat translucent, two pairs of 
white teeth, remote from each other, may be observed through the 
