TEEMATODES 



177 



D. affinis (Linton). Body attenuate, spatulate; anterior portion 

 elliptical; posterior portion cylindrical; posterior suckers with long 

 stalks : length 12 to 40 mm. : in the mouth of the flounder. 



SUBFAMILY 3. MICEOCOTYLINAE. 



Paired anterior suckers present; posterior disc-like region elongate 

 and bearing numerous small suckers, which may be found only on one 

 side, making the animal asymmetrical: 4 genera. 



MlCROCOTYLE van Beneden and Hesse. Posterior 

 region bearing 10 to 120 pairs of minute sessile suckers : 

 on gills of marine fishes; many species. 



M. longicauda Goto. Sucker disc more than half 

 the length of the body; about 120 pairs of suckers pres- 

 ent; 7 mm. long; 2 mm. wide: on the gills of the weak- 

 fish; Newport. 



M. pogoniae MacCallum (Fig. 

 286). Sucker disc about a third of 

 the body ; length 12 mm. : on Pogonias 

 cromis, often very numerous. 



FAMILY 4. GYBODACTYLIDAE. 



Minute forms occurring on the 

 gills of fresh- water and marine fishes ; 

 body minute, usually without suck- 

 ers, but with 2 to 4 retractile ten- 7. 

 tacles at the forward end 

 and a disc at the hinder end 

 armed with numerous hooks: 

 about 9 genera. In the genus 

 Gyrodactylus a curious paedo- 



genesis often occurs. A young individual will come 

 to sexual maturity before it is born and while it is 

 still in the maternal uterus, and produce young in its 

 uterus. This last individual may also have young in 

 its uterus, and 4 generations may thus be found, one 

 inside of another. 



GYRODACTYLTTS Nordmann. Minute, elongated 



worms with 2 short anterior projections and a posterior disc bearing 



about 16 marginal hooks and 2 large central ones; no eyes present: 



4 species. 



G. elegans Nordmann (Fig. 287). Length 1 mm.; width .2 mm.: on 



the gills and skin of the carp and other fresh-water fishes. 



Fig. 286 Microcotyle 



pogoniae (MacCallum). 



References as in Fig. 278. 



Fig. 287Oyro- 

 dactylus elegans 

 (fromBronn). a. p., 

 anterior projec- 

 tion ; p.p., phar- 

 ynx. Other refer- 

 ences as in Fig. 

 278. 



