STUDIES OX THE ECTOPARASITIC TREMATODES OE JAPAX. 237 



conspicuous, egg-shaped, hollow, with a thick wall, and communicat- 

 ing with the penis hy means of a short, slender duct. 



Habitat — Gill of Authias Schlegelii (Jap. Akasngi). 



Locality — Misaki. 



Date— August 1891. 



X. Tristomum, Cuvier. 



This genus was created by Cuvier'> in 1817 for a worm found on the gill of 

 various species of fish and named by him T. coccineinn, a species which was afterwards 

 examined and described more minutely by Taschenberg. Previous to C u v i e r ' s 

 erection of the genus, however, a worm of the same genus had been described (1786) 

 by La Martini ere-', the T, maciilatum of Eudolphi. In 1836 a second species 

 was described by D i e s i n g and was named by him 2'. papillosum, a species which 

 was afterwards made the object of a more minute study by Kbllicker'^ and 

 Taschenberg'''; in 1847 two new species {T. sqnali ani T. inolae) were described 

 by Blanch ard^'; in 1878 T. pelamydis was described by Taschenberg^' and 

 was afterwards redescribed somewhat more at length by Par ona and Perugia''', 

 and more clearly distinguished from the other species ; in 1889 a seventh species, 



1). Cuvier — Regne animal, 1817, t. IV, p. 42. Prom the quotation in Braun's " Wiirmer" 

 (p. 528) it appears that Cuvier at first mistook the anterior end for the posterior, but in 

 a later edition the mistake is corrected (cf. Eegne animal, t. Ill, Paris, 1830. p. 265). 



2). Martiniere — Journ. d. physiqvie, 1787, p. 207. Also in " Voyage de Laperouse," 1798, 

 t. IV, p. 79. Cited on the combined authority of Dujardin, J)iesing, and St.-Remy. 



3). KoUicker — Ueber Tristomum papillosum Dies. Berichte von d. konigl. zoot. Anstalt 

 z. Wiirzburg, II. Ber. f. d. Schuljahr 18i7/48. 1849. pp. 21-27. Cited on Braun's authority. 

 4). Taschenberg — Beitriige z. Kenntniss mar. ectopar. Trematoden, 1879. 



5). Blanohard — Recherches sur I'organisation des vers. Annales d. sciences natur., 3. ser., 

 VIII, 1847. Cited on the combined authority of Braun and St.-Remy. 



6). Taschenberg— Helminthologisches. Zeitsch. f. d. gesamm. Naturwiss., 1878. p. 562-577 

 Cited on the combined authority of Braun and St.-Remy. 



7). Parona e Perugia — Di alcuni trematodi ectoparassiti di pesci adriatici. Op. cit., 

 ser. 2, vol. IX, 1890. Estratto p. 3-5. 



