172 ZOOLOGY OF THE FAR EAST. 
importance in the life of our animal as in the case of permanently parasitic forms. 
The anal opening is situated on the dorsal side of the sucker immediately behind the 
last ring. 
Internal Anatomy. What is most striking about the alimentar}' tract of this 
leech is the extraordinary length of the proboscis. In the specimen no. 2, which was 
studied in sections, it was about 7-5 mm. long, i.e. nearly half as long as the body 
itself. When we consider that in the Glossiphonidae the proboscis measures, as a rule, 
less than one-sixth of the body-length, this must surely be regarded as an exception. 
Moreover, it is of a perfectly cylindrical shape through the greater part of the length, 
even the distal extremity showing no marked diminution in thickness. As regards 
the internal structure, it exhibits no point of difference compared with that of other 
Glossiphonids. In it are seen the usual circular and longitudinal muscle fibres traversed 
by the ducts of unicellular glands which lie dispersed in the anterior region of the 
body. At the root of proboscis they form a thick bundle on each side, reducing the 
lumen to a narrow longitudinal slit. 
The stomach lies chiefly in somites XVI — XX, and is produced laterally into six 
pairs of simple diverticula, the last of which extends backwards as far as somite 
XXIII. The intestine has likewise four pairs of lateral pouches, two of which are 
directed anteriorly and two posteriorly. The six gastric coeca belong probably to 
somites XV — XX, and the four intestinal to XXI — XXIV. As in the case of all 
other Rhynchobdellids the latter are completely enclosed in the sac-like dilatation of 
the dorsal blood-vessel. The rectum is slightly curved in the shape of an S, and 
passes to the dorsally situated anus. 
The specimen which was studied in sections contained in the stomach only a small 
quantity of diatom-shells, fragments of vegetable tissue, etc., but not a trace of 
blood. If we regard these contents as normal, the species should be looked upon as 
vegetarian in diet — no doubt, a very rare case among the Hirudinea. We know of 
certain species of Gnathobdellids which occasionally subsist on the organic contents 
of mud, but this does not seem likely for a Rhynchobdellid, whose slender tube-like 
proboscis is apparently better adapted for sucking than for swallowing solid particles. 
The question can only be settled by the direct observation of living specimens. 
The genital organs are constructed on Glossiphonid type, but exhibit certain 
peculiarities in detail. The male apparatus consists of five pairs of testes which lie 
in somites XVI -XX; the first pair is a little smaller and the last considerably larger 
than the rest. The testes on each side are connected by short vasa efferentia with a 
dorsally situated vas deferens which runs forwards and, after forming several coils in 
somites XIV-XVII, opens in common with its fellow at the posterior margin of 
somite XII. Each testis lies behind and partly beneath the gastric pouch of that 
somite. The female organ resembles that of an ordinary Glossiphonia in almost every 
respect. The ovaries are rather long and extend backwards into somite XVII ; each 
narrows to form an oviduct in somite XV and passes forward in an undulating course 
to the female opening in the anterior part of somite XIII. No special organs for 
copulation are developed. 
