STUDIES ON THE ECTOPARASITIC TEEMATODES OF JAPAN. 209 



Oesophagus short ; anterior portion of the intestinal trunk destitute 

 of lateral branches, but the remaining portion sending out numer- 

 ous lateral bi'anches both inwards and outwards ; those of the 

 inner side posterior to the ovary uniting with those of the opposite 

 side and forming commissures. From the point of union of the two 

 intestinal trunks a single median trunk proceeds backwards ; this, 

 however, is very short and soon breaks up into a few secondary 

 branches. Common genital opening situated about ^ mm. behind 

 the mouth ; penis with six hooks of the usual shape in this genus. 

 Ovary situated in the median line, about the middle of the whole 

 length of the body, long, bent on itself by its middle, and the whole 

 curved, the long axis of the ovary roughly coinciding with that 

 of the body. Oviduct arising from the anterior end of the ovary on 

 the right side of the body, thence proceeding backwards and, curving 

 inwards toward the median line, is continued into the ootyp, which 

 is situated in the median line of the body just in front of the posterior 

 end of the ovary. From the ootyp the uterus proceeds straight 

 forwards. , Genito-intestinal canal rather short, opening into the 

 oviduct half as far from the beginning of the oviduct as from the 

 ootyp, thence proceeding towards the right, and finally opening 

 into the intestine. Vitellaria of the two sides distinct in front 

 but continuous behind. Paired yolh-ducts of the two sides 

 symmetrically disposed at right angles to the long axis of the 

 body, and uniting with each other in the median line. Unpaired 

 yolk-duct opening into the oviduct about hall as far from the ootyp 

 as from the opening of the genito-intestinal canal into the ovi- 

 duct. Testes numei'ous, all situated behind the ovary j vas de- 

 ferens running dorsal to the uterus and usually making some 

 convolutions. 



