STUDIES OX THE ECTOPARASITIC TUEM.ITODES OF JAPAN. 217 



mach smaller than the others. Taschonberg,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, Diesing's statement on this point was 

 almost simultaneously confirmed by Mont icelli'-^) on the one hand and Par on a 

 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 s u1) cylindrical 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 p o s t e r i o r m ;i r g in, with their m a j o r a x e s d i r e c t e d at 

 rio-ht ano'les to the maroin : 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 t li an the others. W i t h t w o pairs o f h (3 o k s between 

 the i n n e r m o s t p a i r of suckers. With a single, dorsal, 

 median vai>'ina. Common li-enital open in o; ventral and 

 m e d i a n . 



1. Hcxacotijlc acuta, n. sp. 

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

 Bodij 11mm. or more in length, divisiljle into three portions 

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



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

 Xaturwissenscli., 52. Bd., 1879. p. 232-265. Cited on Braun's authority. 



2). Montlcelli — Xote elmintologiehe. Boll. d. Soc. d. Natur, in Napoli. Ann. IV, 1S90, 

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



3). Parona e Perugia — Intorno ad alcune Polystomoae e consideraziono sulla sistem. di 

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

 Estratto, p. 15, foot-note. 



