Synhimantus ( Synhimantus ) magnipapillatus n . sp . ( Nematoda , Acuarioidea ) from the Yellow-crowned Night-heron , Nyctanassa violacea cayennensis ( Gmelin ) ( Aves , Ardeidae )

Twenty-eight samples of nematodes recovered from Nyctanassa violacea cayennensis (Gmelin), between 1918 and 1949 in the State of Rio de Janeiro, Brazil, were studied. The samples were deposited in the Helminthological Collection of the Oswaldo Cruz Institute (CHIOC), preserved in vials with Railliet & Henry’s solution (0.85% NaCl solution: 93 ml; formaldehyde: 5 ml; glacial acetic acid: 2 ml) and were processed for study as described elsewhere (Vicente et al. 1993). Preparation of “en face” mounts was in accordance to the method of Anderson (1958). Illustrations were performed with a drawing tube connected to an Olympus light microscope. Measurements are in micrometers, unless otherwise indicated. Classification of the nematodes regarding generic and subgeneric diagnoses follow Chabaud (1975) and confirmation of the taxonomic status of the host was based on Sick (1984).

The report of the new species proposed herein, is part of an investigation of avian nematodes that has been undertaken , 1994, 1995 aiming the obtainment of new data on the helminth parasites of Brazilian birds.

MATERIALS AND METHODS
Twenty-eight samples of nematodes recovered from Nyctanassa violacea cayennensis (Gmelin), between 1918 and 1949 in the State of Rio de Janeiro, Brazil, were studied.
The samples were deposited in the Helminthological Collection of the Oswaldo Cruz Institute (CHIOC), preserved in vials with Railliet & Henry's solution (0.85% NaCl solution: 93 ml; formaldehyde: 5 ml; glacial acetic acid: 2 ml) and were processed for study as described elsewhere .
Preparation of "en face" mounts was in accordance to the method of Anderson (1958). Illustrations were performed with a drawing tube connected to an Olympus light microscope. Measurements are in micrometers, unless otherwise indicated.

REMARKS
Synhimantus (Synhimantus) magnipapillatus n. sp. is, undoubtedly, a very remarkable species in the genus and only can be compared to Synhimantus (Synhimantus) laticeps (Rudolphi, 1819) Stiles & Hassal, 1920, which is the type of the genus and was redescribed by Cram (1927) and Smogorzhevskaya (1990), considering the peculiar structure of the left spicule, with alate free portion and tip slightly dilated and divided in two lateral lobes (Figs 1d, e, 2b).
It is worthwhile to emphasize the great dimensions of the cervical papillae, commonly observed in species of the genus Desportesius Chabaud & Campana, 1949, that is distinguished from Synhimantus Railliet, Henry & Sisoff, 1912, mainly by the localization of the vulvar aperture, which lies very near the anus in females of the former genus, while is approximately median located in those of the latter.
Synhimantus (S.) magnipapillatus n. sp. differs from S. (S.) laticeps by (a) bigger size of the trifurcate cervical papillae (60-70 long in the new species, compared to 34 in S. (S.) laticeps); (b) very delicate and thin cephalic cordons of slight recurrence, reaching, at the most, the nerve ring level in the new species; (c) smaller length of the eggs (10-18, compared to 38-42); (d) absence of papillae in the tail of the females (Fig. 1a-c).