1. In each specimen of L. c. curti the length of the ear measured from the notch when the animal was in the flesh was eight millimeters more than in the dried skin.

"Basilar length" is basilar length of Hensel and the anterior point probably was the posterior border of the alveolus of incisor two. There is some evidence of lack of consistency with respect to the anterior control point.

"Length of nasals" is the overall length, of the two nasal bones, but in Romerolagus the shorter (right) nasal alone seems to have been measured.

"Breadth of rostrum above premolars" is easily duplicated in Lepus but in Sylvilagus the control points are difficult to find. Two other persons and I obtained three different measurements, all different from Nelson's measurements, and we thought that Nelson would have obtained different measurements by measuring the same specimen of Sylvilagus at different times.

"Depth of rostrum in front of premolars" seems to have been taken perpendicular to the inferior longitudinal line of the rostrum, approximately one-half millimeter anterior to the alveolus of the anteriormost cheek tooth.

"Interorbital breadth" was taken across the supraorbital processes, at the narrowest place, but not from the notches medial to the antorbital projections of the supraorbital processes.

"Parietal breadth" is the breadth, across the braincase, taken approximately half way between the squamosal root of the zygoma and the external auditory meatus, where there is a lateral bulge in the squamosal bone. On each side of the skull, the calipers rest on the squamosal bone, not on the parietal bone.

"Diameter of bullae" excludes the paroccipital process and was taken from the anteriormost part of a tympanic bulla, posterolaterally to the part of that same bulla, that is exposed at the lateral side of the base of the paroccipital process.