138 Mr. R. Templeton on Aulastoma heluo. 
little bit of the bounding-line, extending over two rings, is 
quite straight and parallel to its fellow of the opposite side ; 
then follows a curved portion, a nearly semicircular arch, 
engaging three rings, the concavity of those of opposite sides 
directed towards each other. The recurrence of this peculiar 
conformation every five rings gives a very pretty appearance 
to the back of the leech. The two next, or intermediate 
longitudinal lines, conform in a degree to this curved character 
of the innermost line; not so the outermost, which, very near 
the margin, adapts itself toit. This line seems made up of 
a continuous series of minute patchy triangles, the bases 
towards the edge, the apices directed inwards. The narrow 
ledge left between the bases of these triangles and the extreme 
margin of the body isin some specimens tawny yellow, never, 
however, distinctly marked. ‘The belly is dashed with patchy 
markings scattered joosely along the sides. 
The eyes (ten in number) are disposed in a quasiparabolic 
curve conforming closely to the outline of the head and but a 
short distance from the margin of the head ; they are arranged 
in pairs upon the rings. ‘The first pair, side by side on the first 
ring, are much the largest, and are a diameter and half of 
either eye, asunder. The second pair of eyes, of lesser size 
than the preceding, appear to form with them a gentle curve ; 
they are placed somewhat to the rear of the second ring. 
The third pair, lesser still, the eyes decreasing in size gradually 
from front to rear, are on the third ring, aslight degree behind 
the middle. A ring is now skipped, the fourth pair being 
rather in front on the fifth ring. Another ring is skipped, the 
fifth, last, and smallest being very minute and close to the 
front of the seventh ring. : 
The anal sucker, not large, quite round, looking downwards 
and backwards, gives an oblique appearance to that end of 
the body. 
The upper lip projects over the mouth; this latter is quite 
oval, and opens into the gullet, which is capable of great 
expansion. The folds which are described and figured by 
M. Moquin Tandon in the cross section of the head cannot 
be readily made out in the vertical section. At the extre- 
mities of the three largest of these folds is the site of three 
whitish caruncles ; and in front of each of these, he states, is a 
small jaw bearing fourteen teeth ; I have searched for these 
in vain. Some specimens were sent to my friend Dr. Carte, 
the able superintendent of the Natural-History Department of 
the Museum of Art and Science in Dublin ; he could find them 
no more than myself. He found the three whitish tubercles, 
but nothing bearing the slightest resemblance to jaws or teeth. 
