STUDIES ON THE ECTOPAEASITIC TEEMA.TODES OF JAPAN 239 



more or less behind the common genital opening or the 

 male and female openings. 



1. Tristomwn sinuatum, n. sp. 

 (Pis. XX, XXI, XXII.) 

 Body ovato-oval, about 8 mm. long by 7 mm. broad, anterior 

 border concave, with a deep, acute notch at the posterior end, with 

 numerous uniformly scattered, small papillae on the dorsal .side, 

 ventrally smooth; lateral margins sinuate and with a minute crown- 

 shaped chitinous body'^ at the top of each wave (PI. XX, fig. 3). 

 Anterior suckers elliptical, of moderate size, attached to the body at the 

 apices of deep indentations that divide the anterior from the lateral 

 margins of the body. Posterior sucker circular, small, only about twice 

 as large as the anterior sucker, at the apex of the posterior notch, 

 much in front of the posterior end of the body; central area forming a 

 regular heptagon with one of its sides perpendicular to the long axis 

 of the body, with an isosceles -trapezoidal peripheral area corresponding 

 to each of its sides; the two equal sides of the hindmost peripheral 

 area bifurcating towards their outer ends and thus giving rise to a 

 small accessory, triangular area on each side. Hooks present in a 

 single pair, stout, solid, slightly curved, and with free end curved 

 like the claw of a cat (PI. XX, fig. 2), 0.195 mm. long, situated 

 at the ends of the posterior border of the central heptagon. Mouth 

 small, at the plane of the beginning of the hindmost third 

 of the anterior suckers. Plianjnx simple, short, cylindrical. 

 Oesophagus exceedingly short. Intestinal trunks continuous behind, 

 describing some distance in front of the posterior sucker an arc 

 with its convexity turned forwards ; with numerous repeatedly bifur- 



1). In one specimen I have counted fifty-eight of these bodies on eaxjli side. 



