TREMATODES EROM FISHES — LINTON 153 



ments were mounted in balsam but the slide does not appear to have 

 either of the heads. 



From rudderfish (fig. 314) : Twelve (U.S.N.M. No. 8391), collected 

 September 12, 1928. Slender distomes firmly attached to the mucous 

 membrane of the stomach ; there was some inflammation at the point 

 of attachment. Many fragments were obtained and mounted in 

 balsam. Maximum diameter, 0.25 mm. In addition to folds of the 

 uterus crowded with ova there are remnants of tubular vitellaria. 

 The ova are rather elongate, more or less collapsed, from 0.024 by 

 0.010 to 0.027 by 0.012 mm. 



Genus WEDLIA Cobbold, 1860 



WEDLIA BIPARTITA (Wedl) 



Plate 23, Figures 315-317 ; Plate 24, Figure 318 



Wedlia hipartita (Wedl), Odhne:k, "Zoologisclie Studieu" tillagnade Prof. T. 

 Tullberg, pp. 323-392, pi. figs. 12, 13; text figs. 3-6, 1907.— Fuhemann, 

 Handb. Zool., Kiikenthal-Krumbach, vol. 2, pp. 64, 65, 73-75, figs. So, 97, 1928. 



KoelUkeria {Didi/mosoon} thynni Taschenberg, G. A. and W. G. MacCallum, 

 Zool. Jahrb., vol. 39, p. 144, 1916. 



For the older literature see Stiles and Hassall, Hygienic Lab. Bull. No. 37, 

 1908: Didymocystis wedlei Ariola, p. 152; Didymozoon thynni Taschenberg, 

 p. 153; Monostomum Mpartitum Wedl, p. 310; Wedlia Mpartita (Wedl, 

 1844), p. 383. 



Following are brief notes on encysted trematodes from the horse 

 mackerel {Thunnits secundodorsalis) : 



Record of collections. — Thirty or more (U.S.N.M. No, 8392), col- 

 lected July 31, 1914. These were first noted as small yellow spots 

 among the intestinal villi. Later three larger cysts were found 

 among the pyloric caeca. The egg-filled portion of one of these 

 trematodes which was removed from its cyst measured 1.45 mm. in 

 length and 1.71 mm. in breadth. A protruding anterior end meas- 

 ured 0.45 mm. in length; breadth, anterior, 0.30 mm., posterior, 0.03 

 mm.; oral sucker, length, 0.15 mm., breadth, 0.12 mm.; no pharynx 

 noted. Ova, 0.021 by 0.014 mm. 



Another, an immature specimen, was somewhat dumbell shaped. 

 Measurements: Length, 1.24 mm., breadth of anterior potrion, 0.30 

 mm., of middle portion 0.04 to 0.07 mm., posterior portion, 0.48 mm. ; 

 oral sucker, length, 0.10 mm., breadth, 0.09 mm.; pharynx, length, 

 0.04 mm., breadth, 0.02 mm. 



Among the numerous specimens in the collection mounted in 

 balsam is one in which the anterior ends of two trematodes protrude 

 side by side from the oblong massive portion in which only folds of 

 the uterus, crowded with ova, and a few portions of the tubular 

 vitellaria can be made out. In one of these the uterus, and in the 

 other the ejaculatory duct can be seen, each opening at the posterior 



