NEOTROPICAL MONOGENOIDEA .28. ANCYROCEPHALINAE (DACTYLOGYRIDAE) OF PIRANHA AND THEIR RELATIVES (TELEOSTEI, SERRASALMIDAE) FROM BRAZIL AND FRENCH-GUIANA - SPECIES OF NOTOZOTHECIUM BOEGER AND KRITSKY, 1988, AND MYMAROTHECIUM GEN-N

Seven species (5 new) of Notozothecium and 4 new species of Mymarothec ium are described and/or reported from the gills of 13 species of Serr asalmidae from the Brazilian Amazon and 1 serrasalmid from French Guia na: N. bethae sp. n. from Myleus pacu and M. rhomboidalis; N. euzeti s p. n. from Acnodon normani; N. foliolum sp. n. from Pristobrycon sp.; N. minor from Pygocentrus nattereri, Serrasalmus elongatus, S. rhombeu s, S. spilopleura, and Serrasalmus sp. (2n = 58); N. penetrarum from P ygocentrus nattereri; N. robustum sp. n. from Pristobrycon striolatus; N. teinodendrum sp. n. from Pristobrycon eigenmanni, Pristobrycon sp. , Serrasalmus elongatus, S. gouldingi, S. manuelli, S. rhombeus, and S errasalmus sp. (2 of Jegu); Mymarothecium dactylotum sp. n. from Prist obrycon sp., Serrasalmus rhombeus, Serrasalmus sp. (2 of Jegu), and Se rrasalmus sp. (2n = 58); M. galeolum sp. n. from Pristobrycon eigenman ni, Pristobrycon sp., Pygocentrus nattereri, Serrasalmus gouldingi, an d S. rhombeus; M. perplanum sp. n. from S. spilopleura; and M. whittin gtoni sp. n. from Serrasalmus rhombeus, S. spilopleura, and Serrasalmu s sp. (2n = 58). The generic diagnosis of Notozothecium is emended, an d Mymarothecium gen. n. is proposed for species with an expanded nonsc lerotized vagina opening on the right side of the trunk, an anteromedi al projection on the ventral bar, and a hooked termination of the arti culation process of the accessory piece.