0.08 mm in length. The 1st pair of nniddle hooks has a weakly curved 



point and straight base, between which there is a small widening. This 



pair more closely resembles somewhat-altered edge hooks in its structure 



than middle hooks. The 2nd pair has a typical dactylogyrid shape with a 



powerful point and well-developed extensions. The length of the 1st pair 



is about 0. 0Z4 mm and the 2nd about 0. 022 mm. Further development 



has been poorly studied. The youngest individuals discovered on the host 



(Fig. 238) already have 6 pairs of formed attaching clamps and a small 



growth in which are located one pair 



of lateral hooks, and 2 pairs of middle 



hooks remain on the posterior end of 



the disc. The sex system begins to 



be incepted but the sex armature has 



not yet been formed. Suckers of the 



buccal cavity are incepted on the 



anterior end of the body along the 



sides of the pharynx. During further 



development a gradual increase in the 



number of pairs of attaching clamps 



OMlUM 



Fig. 240. Microcotyle mugilis Vogt, Fig. 241, Microcotyle pomatomi 



attaching armature (left half) of the Goto, adult worm from the gills of 



larva which was extracted from the Pomatomus saltatrix (L. ) from 



egg. the region of Sebastopol (Black Sea). 



takes place until it reaches the final size. The development of the interior 

 organs takes place simultaneously with this. The outgrowth which bears 

 the edge and miiddle hooks (of the "larval" attaching disc according to 

 Remley) is preserved until the development of 13 pairs of attaching clamps 

 (Fig. 239), but anaong the majority which have from 10 to 15 pairs it is 

 absent, just as among all older individuals. The sex armature is incepted 

 approximately toward the time of the disappearance of the "larval" attach- 

 ing disc or somewhat later. The testes are incepted earlier than the ovary. 



206 



224 



