162 



s. GOTO. 



curve in the lateral portions, corresponding to the circular or oval 

 outline of the worm. The same writer did not observe the diag-onal 

 fibres in OnchocoUjle appendiculata and Pseudocotyle squatinae ^'; but 

 since they are present in all the species 1 have examined, they were 

 probably overlooked by him. 



Internal to the diagonal muscle, and separated from it by a 

 greater or less amount of connective tissue, run the longitudinal 

 muscular fibres in parallel bundles of greater or less strength. 

 They are more strongly developed on the ventral than on the dorsal 

 side of the body, as is usual in most Trematodes, and cause a slight 

 curve of the body on the ventral side when the worm is killed with 

 hot sublimate. The fibres that constitute the bundles are but loosely 

 united together by connective tissue, and form by no means such 

 compact muscular bundles as we see in some other Trematodes. 

 Tliey appear in cross-section as dots, separated from one another by 

 a greater or less amount of connective tissue between. Some of the 

 fibres of a bundle often diverge from their previous course, and enter 

 into the formation of a neio^hborino^ bundle. Most of the lono;itudinal 

 fibres combine toward the posterior part of the body to form a certain 

 number of strong bundles, which proceed posteriorly, and are inserted 

 one to each sucker on the median chitinous piece of the posterior 

 wall (Fig. 5). 



The dorso-ventral muscles (dvm in Figs. 11, 13, 16. !24) 

 are well developed. Each muscle generally breaks up into a few 

 branches dorsally and ventrally before being inserted into the base- 

 ment membrane. They traverse the brain, vitelline body, and other 

 internal organs. In longitudinal (sagittal) sections of a specimen, in 

 which the vitelline body has not yet well developed, the dorso- 

 ventral muscles are seen to be placed at pretty regular intervals. In 



I) Tascheaberg — Weitere Beitrüge zur Keautaiss ectopar. mar. Treinatoclen. Halle, 1879. 



