STUDIES OX THE ECTOPAEASITIC TREMATODES OF JAPAN'. 933 



IX. EriBDELLA, Blainville. 



Au excellent summary of the history of this genus up to 1801 is found in P. J, 

 V. Beueden's " Mémoire sur les vers intestinaux" (pp. 18-21), and I have nothing 

 to add to it. It has been already pointed out by B r a u n '> that D i e s i n g ' s genus -) 

 Benedenia is based without any sufficient ground on Ejnhddla sciaemie, P. J. v. Bene- 

 den. In 1881) a new species E. Tlciidortf'ii (^l'hi/Iliiie Tlcndorilu, hmHiov»^^)) was 

 described, so that tlie genus contains at present three species, vi::., the one just men- 

 tioned from the surface of the abdomen of Conjphaena hijijninis, K. hißjwglossi, 0. Fr. 

 Müller from the body surface of Vlcuroncctcs Idj^pofjlossus, and K. sciacnae, P. J. v, 

 Beneden from the body surface of Sciacnn aquila. 



P. J. V. Beneden*) gives the following diagnosis of the genus: "Corps de 

 forme ovale, mince et aplati ; tt'te pourvue do deux ventouses, une grande ventouse 

 eu arrii'ro armée do crochets et couverte en dedans de papilles régulièrement dis- 

 posées, avec le bord frangi ; les orifices sexuels situes sur le bord à droit près de la 

 ventouse buccale ; deux vésicules pulsatiles, s'ouvrant en avant, ù qnehj^ue distance 

 du bord. Ils vivent sur la peau des poissons " — a diagnosis which has been repro- 

 duced in essence by subsequent writers. I believe I can improve it as follows : 



Body flat, thin, more or less oval; witli a pair of el- 

 liptical or circular suckers at the anterior end of the 

 body on either side of tlie mouth, and with a circular or 

 elliptical sucker at the posterior end. The posterior 

 sucker destitute of any septa, and with tliree pairs of 

 hooks near its posterior border. Mouth suLterminal. 

 Common genital (opening ventral, on the left side of 

 the body, just l)ehind one of the anterior suckers, and 

 near the mar^-in of the body. Yao-inal oueninu' ventral, 

 on the same side as the common genital opening, and 



1). Brann — Würmer, p. 518. 



2). Diesing— Revision d. ]\ryzheluiiuthen, p. 3(!3. Xachtriige 11. Verbeper. z. Rev. cl. 

 Myzhelm., p. 19. 



3). Linstow— Beitrag z. Anat. v. Pliylliue Hondorffii. Archiv f. mile. Anat. Bd. 33, 1889. 

 pp. 153-180. 



4). P. J. V. Benedeu— Mémoire etc. p. 18. 



