STUDIES 0\ THE ECTOPARASITIC TKEMATODES OF JAPAN. 257 



arranged in a Iiorse-shoe shape ; penis with 



10 hooks D. tetroJonis. p. 213. 



i^ Body always symmetrical ; with a pair of exceedingly 

 small spheroidal suckers within the mouth, and with 

 four pairs of semi-ellipsoidal suckers at the posterior 

 end of the body, the innermost pair of which is 

 considerably smaller than the others ; with two pairs 

 of hooks between the innermost pair of posterior 



suckers HEXACOTYLE. p. 217. 



*iBody acutely pointed in front, broad in the 

 middle portion as well as at the posterior end, 

 about 11 mm. long; with the outer pair of 

 hooks at the posterior end solid, about 0.09 

 mm. long ; vagina armed with chitiuous teeth.H. acuta, p. 217. 

 "'•■-Body with a lateral swelling ou each side close 

 to the front end, w'ith the anterior portion 

 slender, broad in the middle part as well as at 

 the posterior cud, about 18 mm. long; with the 

 outer pair of hooks hollow and about 0.125 mm. 

 long; vagina armed with chitiuous teeth ...II. grossa. p. 220. 

 I^Body always symmetrical, elongated and slender; 

 with an ellipsoidal sucker around the mouth-cavity ; 

 with three pairs of hemispherical suckers at the 

 posterior end of the body, each with a semicircular 

 chitiuous rod with a claw at one end ; with a sub- 

 cylindrical appendage projecting from between the 



foremost pair of suckers ONCHOCOTYLE. p. 223. 



'"^Posterior suckers arranged in a horse-shoo 

 shape ; appendage bifid at the extremity, with 

 a pair of small suckers at the bifid end, and a 



pair of hooks between them 0. spinacis. p. 22i. 



f ^ Body always symmetrical, flat, heart-shaped ; with 

 a rudimentary sucker arouud the mouth; with 

 a circular posterior sucker, the internal surface of 

 which is divided into a subceutral and seveu peri- 



