EXPLORATION OF ALASKA. 217 
missura pedalia nearly as long as the diameter of the pedal ganglia ; 
the subcerebral lying rather close up to the pedal; the visceral quite 
free, much thinner. A very short-stalked smaller ganglion (fig. lc) 
connected with the under side of the right visceral ganglion, gives off 
a nerve that swells into a new ganglion, which sends out three nerves 
(N. genitalis). The olfactory ganglia short-stalked, spindle-shaped. 
The buccal (fig. 1d) and the gastro-cesophageal ganglia (fig. le), nearly 
as in the L. hystricina ; the commissure between the first extremely 
short, the gastro-cesophageal somewhat smaller. 
The nervi optici one to one and a-half times as long as the diameter 
of the cerebral ganglia; the eyes with black pigment, yellowish lens. 
The otocysts (fig. 1) lying rather backwards, a little smaller than the 
eyes; the otokonia of the usual form, in number about fifty. The 
leaves of the rhinophoria without spicula. In the skin were almost 
no spicula and no larger or calcified ones on the surface of the rigid 
papilla of the back, which thus were rather smooth. In the intersti- 
tial connective tissue small calcified cells, but no larger spicula. 
The mouth-tube as in the L. hystricina. The bulbus pharyngeus 
as in that species, but the sheath of the radula shorter and less 
prominent, bent upwards, sideways or down and forwards. On the 
interior part of the nearly colorless labial disk, the usual belt of 
(about twelve to fifteen) rows of small denticles. The tongue strong, 
rather long, with curved superior and nearly straight inferior margin. 
In the mature radula twelve to fourteen or sixteen rows of teeth, 
further backwards fifteen or sixteen to eighteen rows of developed, 
and three of partly developed teeth; the total number of rows thus 
thirty, thirty-one or thirty-five to thirty-seven. The median plates 
(fig. 14) of nearly the usual furm, in the under side rather excavated, 
with thickened margins. ‘The large lateral plates (fig. 13) formed 
nearly as in the L. hystricina, but larger, reaching a height of 0.12 
mm.; the denticulation of the interior margin of the hook stronger, 
with more (about twenty) denticles and reaching farther out towards 
the end of the hook. ‘The exterior plates nearly of the same form as 
in the last species, reaching to the height of about 0 6 mm. 
The sucking-crop quite as in the former species. 
The salivary glands much smaller than in the former species, re- 
duced to a large, scarcely lobed, whitish mass on each side of the 
root of the cesophagus. 
The csophagus somewhat spindle-shaped. The stomach included 
in the liver. The intestine issuing from the liver behind its middle. 
