373] 



PSEUDOPHYLLIDEA FROM FISHES— COOPER 



85 



known form of trident (Figs. 15 to 16). While the latter and the scolex as seen 

 in surficial view agree in essentials with the descriptions and figures given by- 

 various authors, e.g., Rudolphi (1810:32, Tab. IX, Figs. 6-11), Wagener (1854: 

 26, Tab. 2, Figs. 17-21), Olsson (1893:20, Figs. 28-32) and Fuhrmann (1910:86, 

 Fig. 1), it cannot be said of the material studied that, as stated by the last 

 writer, " . . . chez T. nodulosus on ne pent voir aucune limite entre le scolex 

 et le cou du Bothriocephale. ..." For in lateral view (Fig. 16) the bothria 

 are distinctly separated from the beginning of the body, which is, as just men- 

 tioned, not nearly so apparent in surficial view. As shown in figure 15, the 

 middle hook of the trident scarcely protrudes thru the cuticula, since it is the 

 root for muscular attaclmient. The upper median hook (cf. Wagener) which 

 does protrude in the adult is evidently not yet developed (Figs. 17 and 18). 

 For a short distance behind the scolex the body is somewhat rectangular in 

 cross-section, the sides of the rectangle being, however, slightly convex and 

 not concave as in the rohustus t>'pe, and hence not so very different from the 

 cross-section of the body farther back. But the material contained in the 

 lot from the intestine of Esox masquinongy does not strictly answer this de- 

 scription since the body just behind the scolex is slightly concave on all sides. 

 Otherwise the specimens are distinctly of the 7iodulosus type. It should be 

 mentioned, too, that one of this lot showed a very short but distinct caudal 

 piece; but this with the general stout appearance of all of them may be account- 

 ed for by the possibility that they have reached the intestine of one of their 

 final hosts and continued their development. Likewise a few of the specimens 

 of the lots from the "white bass" and Stizostedion canadense were provided with 

 short caudal appendages. The smallest example of this type and of all the 

 material, for that matter, at hand was that from Micropterus dolomieu of the 

 accompanying table. Altho it is only a little over two and a half millimeters 

 in length, its posterior end shows that a portion, perhaps a caudal piece, has 

 been torn away. The following table gives measurements of a number of 

 specimens of the nodulosus type, similar to those given above for the robustus 

 type, with Fuhrmann's data for comparison: 



