Hinidinea. 
173 
The vascular system shows exactly the same structure as in other Glossiphonids. 
The dorsal vessel has the usual fifteen thick-walled chambers, each provided with a 
valve-like cellular mass just in front of the constriction separating it from the next 
one. As already stated, it is dilated posteriorly into a spaceous sac to enclose the 
whole intestine with its coeca. The number and course of the lateral branches, by 
which the dorsal vessel communicates with the ventral, are the same as in Glossi- 
phonia ; namely, four pairs in the anterior and seven pairs in the anal region. There 
is also an anterior median branch which enters the proboscis at its posterior end and, 
after passing through its entire length, bifurcates near the tip and then joins again 
to form the ventral median branch opening into the ventral vessel. In sections both 
the dorsal and ventral vessels appear very conspicuous on account of their unusually 
large size, the diameter attaining in some places nearly one-fifth of the breadth of the 
body. 
As in other Rhynchobdellids, the coelome appears as a system of complicated 
sinuses. There are a dorsal, a ventral, and two lateral sinuses which communicate 
with each other by segmentally arranged transverse canals. The lateral sinuses are 
well developed throughout the whole length, but they have no muscular walls, such 
as are always present in Ichthyobdellids ; nor could any pulsating vesicles be found, 
which are characteristic of a number of genera in this family. Judging from their 
size the lateral sinuses seem to play an important part in the respiratory function, 
making the development of other apparatus superfluous. 
There are only eight pairs of nephridia belonging to somites XVI-XXIII. This 
is by far the least number of nephridia found among the Hirudinea, the Gnathobdel- 
lids having 16-17, the Glossiphonids usually 13-16, and some Ichthyobdellids 11 
pairs. Each organ is quite independent of its neighbours, as is the rule in the Glos- 
siphonidae ; its shape and position, too, are exactly the same as in other members of 
the family. I have paid special attention to the study of these organs in sections, 
but nowhere could I find a communication between two neighbouring organs which 
would indicate the formation of plectonephridia resembling those of certain Ichthyob- 
dellids. The nephridial canal opens, without forming a special bladder, into a small 
invagination of the integument near the posterior margin of the first annulus. At 
the inner extremity of each nephridium is a capsule with ciliated funnel projecting 
into the ventral sinus. Their position is indicated by minute rings in pi. vii, fig. 12; 
as a rule, they are placed at each side of the nervous ganglion of the somite to which 
they belong. In every case the capsule lies in direct contact with the innermost per- 
forated cell of the nephridium, so that it seems hardly credible that these two struc- 
tures are independent in function, as maintained by many authors. 
The nervous S3^stem differs from that of other Glossiphonids in so far as the 
anterior and posterior ganglionic masses contain each a ganglion more than usual. 
To compensate this, there are between these masses only nineteen separate ganglia 
instead of twenty-one. As shown by a careful analysis, the cephalic ganglionic mass 
is composed of seven, and the anal of eight ganglia. Each ganglion contains, as 
usual, six packets of nerve-cells, and the boundary between two ganglia is indicated 
