Observation on the anatomy of the proboscis and of the ductus nasopalatinus and ductus vomeronasalis of Solenodon paradoxus Brandt, 1833.

Solenodon paradoxus possesses a proboscis-like, elongated rostrum which is very motile. The rhinarium is remarkable because of its distinctly developed sulci limitantes, sulcus medianus rhinarii, and postnarial hairless integumental pads topographically similar to the crenated folds found in Setifer and Echinops. Rhinarial glands are also present. The sulcus medianus proboscidis (rhinarii) is continuous with the vestibulum oris. Integumental folds affixing the upper lips to the gum are absent, as are the labial part of the sulcus rhinarii and the sulcus papillae palatinae. The anatomical condition of the proboscis and the anterior part of the palate cannot be considered primitive in a phylogenetic sense, because it is essentially different from the situation found in Didelphys, Tupaia, and the lemuriform primates. The vomeronasal organ is in direct communication with the nasal cavity; there is no communication with the ductus nasopalatinus or with the oral cavity. In contrast to Didelphys, Tupaia, and the prosimians so far studied, the nasal cavity opens directly through the nasopalatine duct into the oral cavity proper. These differences are likely to be of taxonomic and phylogenetic significance, although definite conclusions in this regard should not be drawn until the respective conditions of the other insectivores have been studied.