STUDIES OX THE BCTOPARA.SITIC TREMA.T0DE3 OF JAP AX. 217 



much smaller than the others. Taschenberg,i) on the other hand, in a paper 

 published in 1879, repeated the incorrect statements of the earlier writers as to the 

 number of suckers. In 1890, however, Biasing's statement on this point was 

 almost simultaneously confirmed by M o n t i c e 1 1 i^) on the one hand and Parona 

 and Perugia') on the other. So far as I know our knowledge of this genus 

 has after all been very incomplete. The generic diagnosis I give is as follows : 



Body flattened, elongated, broad in the middle 

 portion, slender and subcylindrical in front, acutely 

 pointed at the anterior end, broad and expanded be- 

 hind; posterior margin forming two sides of an isosceles 

 triangle, with a notch at the apex. With a pair of ex- 

 ceedingly small, spheroidal anterior suckers within the 

 mouth. Posterior suckers elliptical ; in four pairs close 

 to the posterior margin, with their major axes directed at 

 right angles to the margin ; each with three chitinous 

 supporting pieces arranged in a line on the major axis of 

 the sucker; the innermost pair of suckers very much 

 smaller than the others. With two pairs of hooks between 

 the innermost pair of suckers. With a single, dorsal, 

 median vagina. Common genital opening ventral and 

 median. 



1. Hexacotyle acuta, n. sp. 

 (PI. XII, figs. 5-7 ; PI. XIII, figs. 1-3 ; PI. XIV, figs. 1-5.) 

 Body 11mm. or more in length, divisible into three portions 

 separated from each other by two broad constrictions, an anterior slender 



1). Taschenberg — Zur Systematik der monogen. Trematoden. Zeitschr. f. d. gesamm. 

 Katurwissensoh., 52. Bd., 1879. p. 232-365. Cited ou Braun's authority. 



2). Montioelli — Note elmintologiche. Boll. d. Soo. d. Natur. in Napoli. Ann. IV, 1890, 

 fasc. II. p. 195. Cited ou Braun's authority. 



3). Parona e Perugia — Intoruo ad aloune Polystomeae e considerazione sulla sistem. di 

 questa famiglia. Atti del. Soc. Ligust. d. Scienz. Natur. e Geogr. Vol. I, fasc. Ill, 1890. 

 Estratto, p. 15, foot-note. 



