Morphology of the premolar canal in extant leporids and ochotonids.

<p>A. <i>Sylvilagus palustris hefneri</i> (AMNH 256404), right maxilla and palatine in lingual view; wire shows an inclined course of the canal. B. The same, note large dorsal opening of the premolar canal in the infraorbital groove (arrow). C. Dorsal entrance to the premolar canal in <i>Ochotona princeps saxatilis</i> (AMNH 32717), note relatively small diameter of the canal.