MOORE: HIRUDINEA OF SOUTHERN PATAGONIA. 673 



valves, which correspond in position to the preganglionic muscular sheets, 

 divide it into as many slight sacculations, the posterior ends of the last 

 of which are produced into a pair of quite rudimentary caeca, of such 

 small size and so closely embracing the intestine that they were entirely 

 overlooked upon the first examination. They scarcely extend beyond 

 the limits of the neural annulus of XIX. 



The intestine is somewhat distended with food, to which, in contrast to the 

 emptiness of the stomach, the somewhat greater diameter of the former is 

 probably due. Its walls are excessively thin and delicate and somewhat 

 regularly, but slightly, sacculated for the anterior half. It reaches to XXIV, 

 beyond which a short rectum extends to the anus. That this species is 

 not a habitual blood-sucker, but, like our common Hcemopis marmoratus, 

 subsists chiefly on small invertebrate animals and the organic contents of 

 mud, is shown by the contents of the intestine and stomach, which consist 

 of remains of tubificid worms, rhabdoccele planarians and diatoms. 



Reproductive Organs. The reproductive organs (Plate L, fig. 12), 

 while approaching in character most closely those of H<zmopis, yet exhibit, 

 if the single example dissected be entirely normal, a number of striking 

 peculiarities. The pairs of testes occupy the interganglionic intervals 

 from XIV/XV to XXII/XXIII ventrad of the alimentary canal. The 

 first pair presents the ordinary appearance, but the remaining eight are all 

 double, two closely appressed but perfectly distinct spheroidal testes with 

 separate efferent ducts occupying each interval. The actual number of 

 testes is, therefore, at least seventeen pairs and, as the vasa deferentia 

 extend some distance posterior to the last, it is probable that additional 

 material would permit of the demonstration of at least one more pair ; and 

 a pair may also occur at XIII/XIV. Both the vasa efferentia and vasa 

 deferentia are excessively slender, but the latter in particular are rendered 

 very conspicuous by a thick covering of pear-shaped groups of gland cells, 

 which are far more thickly clustered dorsally than ventrally. Anterior to 

 the testicular region the glands diminish in number and disappear alto- 

 gether in somite XII. At the same time the walls of the sperm duct 

 acquire greater firmness and it may be traced as a tortuous tube as far 

 forward as the position of the male pore, where it bends mesially in a 

 recurrent limb. 



In somites XIV and XV each vas deferens becomes converted into a 

 closely coiled, twisted and massed tube with thick walls and of irregular 



