Dipetalonema (Acanthocheilonema) didelphis sp. n. (Nematoda: Filarioidea) from opossums, with a redescription of D. (A.) pricei (Vaz and Pereira 1934).

Dipetalonema (Acanthocheilonema) didelphis sp. n. recovered from the subcutaneous and periesophageal connective tissues of Didelphis virginiana from several localities in the United States and of D. marsupialis from Colombia is described. Dipetalonema didelphis sp. n. resembles D reconditum and D. mansonbahri in size, in lacking a two-segmented buccal capsule, and in the female having a long, digitiform tail. Dipetalonema reconditum, however, has a much longer glandular esophagus and D. mansonbahri has a rounded cephalic extremity delimited by a necklike region. The male of D. didelphis sp. n. differs from both in the structural details of the spicules and in having a higher spicular ratio. The microfilaria is much shorter than that of either D. reconditum or D. mansonbahri. Dipetalonema (A.) pricei adults are redescribed from the paratype specimens, and the microfilaria is also described. Dipetalonema pricei most closely resembles D. dracunculoides in size and in the presence of a well-developed, two-segmented buccal capsule, but the latter species has a much longer glandular esophagus. These two species also differ in the appearance of the spicules.