STUDIES OX THE ECTOPARASITIC TREMATODES OF JAPAN. 259 



long ; antoi-ior snclvors elliptical ; posterior 



sucker with a pair of notches on its anterior 



and posterior borders E. ovata. p. 235. 



•2 Internal surface of the posterior sucker divided 



into a central and seven peripheral areas TRISTOMUM. p. 238. 



§iBody broadly ovate, about 8 mm. by 7 



mm.; anterior border concave, lateral 



margin finely sinuate, with about 58 



chitinous corpuscles; posterior sucker 



small, not reaching the posterior end of 



the body proper, with the central area 



regularly heptagonal and with a small 



triangular accessory area on each side of 



the hindmost peripheral area T. sinuatum. p. 239. 



§2 Body broadly oval, about 13 mm. by 12 



mm. or larger; anterior border convex; 



lateral margin entire, without any 



cJjitinous corpuscle ; posterior sucker 



large, with a diameter equal to about i 



the length of the body proper and pro- 

 jecting beyond it by one-third of its 

 diameter, with the central area 9-sided... T. ovale, p. 241. 

 §^Body oval, about 11.5 mm. by 18 mm., 

 with the breadth greater than the length ; 

 anterior border concave ; lateral margin 

 entire, with numerous transverse series 

 of chitinous corpuscles, each series con- 

 sisting at most of five corpuscles ; posterior 

 sucker small, barely reaching the posterior 

 end of the body proper ; with the central 

 area regularly heptagonal and raised a 



little above the peripheral areas T. rotundum. p. 245. 



§^ Body elongated and slightly ovate, about 

 G mm. by 8 mm.; anterior border 

 -shaped; lateral margin entire and 



