19 
In general form it resembles H. ligera, but may be distinguished 
by the absence of umbilicus, and, upon particular examination, by 
the teeth, which are situated far within the aperture. In the col- 
lection of the Academy. 
II. LIGERA. — Shell subglobose, pale yellowish horn color, 
polished ; body whorl pellucid, yellowish white, opahe beneath 
near the aperture ; volutions rather more than six, all except the 
apicial one, wrinkled across ; spire convex, a little elevated ; um- 
bilicus very small ; suture not deeply impressed ; labrum not 
reflected. 
Inhabits Missouri. Greatest length three-tenths, oblique length 
less than nine-twentieths, transverse diameter less than eleven- 
twentieths. 
Approaches nearest to H. glaphyra, but is readily distinguished 
by the greater convexity of the spire, and the smaller umbilicus. 
Rather common. In Lister’s Conch, on pi. 81 , fig. 82 , a shell is 
represented which may be intended for this species. 
H. soLiTARiA. — Shell subglobose, with two or three revolving, 
rufous lines ; spire conico-convex ; volutions five and a half, wrin- 
kled across and rounded ; suture rather deeply impressed ; aper- 
ture wide, embracing a rather small portion of the penultimate 
whorl ; labrum not reflected ; umbilicus large, distinctly exhibit- 
ing ail the volutions to the apex. 
Greatest transverse diameter nearly one and one-fifth of an inch. 
Inhabits lower Missouri. 
But a single specimen was found; it was a dead shell, destitute 
of its epidermis. It is a very distinct species. 
H. JEJUNA. — Shell subglobular, glabrous, pale reddish brown ; 
volutions five, slightly wrinkled, regularly rounded ; spire con- 
vex ; suture rather deeply impressed ; aperture dilate lunate ; 
labrum a little incrassated within, not reflected ; umbilicus open, 
small. 
Breadth rather more than one-fifth of an inch. Inhabits the 
Southern States. 
Animal — light reddish brown, with a granular surface, longer 
than the breadth of the shell ; oculiferous tentacula elongated, and 
rather darker than the body. 
This shell is very closely allied to AT. sericea of Southern 
Europe, but it differs from that species in being destitute of the 
