CONTRIBUCION AL CONOCIMIENTO DE LOS NEMATODOS DE LAS AVES DE MEXICO. I

Resumen

A new species of the genus Contracaecum, Contracaecum hoffmanni, that is parasitic in a wild bird, Cochlearius cochlearius, is described in the present work. The characteres of the new species are the following; body thick, short, yellowish, posterior end conical; the esophagus of the female is 3.15 mm. long and the eggs, which are almost spherical, are 0.52 mm. long and 0.049 mm. wide. The male has 23 pairs of preanal papillae, 2 adanals and 7 postanals; the spicules are equal and measure 1.424 mm. in length; a gubernaculum is present but its pieces are little chitinized.