us THE LEECHES OF MINNESOTA 



life the body is soft and limp and possesses a great facility for con- 

 traction and elongation and other changes of form. 



While large, the mouth is more contracted than in II. plumb cits 

 and the lip narrower and more prolonged. The five pairs of eyes have 

 the arrangement usual in the family ; they are all of relatively small 

 size and the fourth and fifth pairs quite inconspicuous. 



The clitellum is a thick and prominent glandular girdle extending 

 over fifteen annuli from X bj to XIII bs } often rather within the latter 

 but apparently never as far as its middle. The female orifice is similar 

 but drawn out laterally to a slit-like form and usually well within an- 

 nulus XII bj, sometimes as far back as its middle or so far forward 

 as to lie in the furrow XII a^/bj. 



Seventeen pairs of nephridiopores can be readily distinguished 

 on the posterior margins of the first annulus (ai) of VIII and the 

 second annulus (&.?) of somites IX to XXIV inclusive. They, to- 

 gether with the metameric sensillae, have the positions usual in the 

 genus and the marginal sensillae show the same tendency to become 

 subdivided. There are no cutaneous papilla?, the skin being smooth. 

 However, the short shallow wrinkles seen in many large leeches are 

 remarkably conspicuous in preserved specimens of this species and give 

 to the interannular furrows a peculiar zigzag course which is especially 

 pronounced toward the ends of the body. The usual non-metameric 

 sense organs are present in abundance and are especially numerous 

 on the lips. The annulation differs in no essential feature from that 

 already described for Haemopis mariuoratis. 



While retaining all of the characteristics of the genus the repro- 

 ductive organs differ considerably in the proportions of the several 

 regions of the complicated ducts from all of the other species found 

 in Minnesota. The epididymis is remarkably massive and lies chiefly 

 caudad of the corresponding sperm sac which is consequently not so 

 largely enclosed in its coils as in /7. lateralis. The sperm sac is re- 

 markably large, being much wider than and about half as long as the 

 atrium when fully distended, as in the specimen figured. Its anterior 

 end is just behind ganglion XII and tapers into the ductus ejaculatori- 

 us which is noteworthy for its shortness. In almost every instance the 

 allium is doubled on itself at about the middle, so that the two limbs 

 are approximately equal and the blind glandular end is usually a little 

 anterior to the male pore. Either the right or left ductus ejactilatorius 

 may pass beneath the nerve cord. 



The ovaries are situated in the anterior part of XITT immediately 



