the attaching disc there is a large pyramidal growth which is shed at the 

 same time as the shedding of the ciliary epithelium. The ciliary covering 

 is distributed along the sides of the body extending somewhat to the dorsal 

 and ventral surfaces. The cells of the ciliary epithelium lie in a con- 

 tinuous layer from the anterior to the posterior end including the pyra- 

 midal growth. Epithelial cells are flat, elongated and lie with their 

 posterior edges leaning slightly against the following cells. Often one or 

 two of the epithelial cells falls off considerably later than the others and 

 then their borders are even more visible. The anterior end of the larva 

 is equipped with cephalic glands. A large pigmented eye is located be- 

 tween the first and second fourths of the body. This eye does not have P- 1^8 

 regular contours and varies from a pyramidal to a tetrahedral shape. 

 Often the pigmented granules of the eye scatter around, so to speak, and 

 the eye gives the inripression of degenerating in the larva which has just 

 emerged from the egg. Below the eye is located a rounded pharynx, be- 

 yond which lies the metabolizing sac -shaped intestine of irregular shape 



having microgranular contents of 

 greenish color. The attaching disc 

 bears exactly the same armature 

 (Fig. Z25) as among the larvae of 

 -„, -,jA .)^ Mazocraes alosae Hermann. The 



sizes of the 5 pairs of edge hooks 

 "''''^^^ ^^^ ^ P=^ fluctuate around 0. 02 mm and of 



the larger pair--about 0.022 mm. 

 The gradual loss of the ciliary 

 Fig. 225. Octostoma scombri Kuhn, epithelium begins after the attach- 

 attaching armature of the free- ment of the larva. It starts from 



swimming larva. the middle of the body and continues 



progressively to both ends. The 

 posterior pyramidal growth falls off last; at that time the edge hooks 

 unfold and cut through. Further development proceeds just as among 

 Mazocraes alosae. We shall note that the middle hooks which are in- 

 cepted later reach considerable sizes among adult individuals, and take 

 an active part in attachment. 



The data of Gallien and Calvez basically coincide with ours; 

 however, the only difference is that they did not notice the differences in 

 sizes of the chitinous hooks which, it is true, are very insignificant. 



24. The development of Diclidophora Diesing ( = Dactycotyle 

 Beneden and Hesse, Dactylocotyle Marshall) 



The genus Diclidophora (Fig. 54) represents a large group of 

 marine monogenetic trematodes which are characterized by the presence 

 of 8 sucker-shaped clamps on the disc and by a system of chitinous plates 



215 



