RACCOONS OF NORTH AND MIDDLE AMERICA 23 



EXPLANATIONS 



MEASUREIVIENTS 



All measurements of specimens are in millimeters. The weights 

 given are in pounds. Adult males usually exceed adult females in 

 dimensions, and the measurements are, therefore, presented according 

 to sex. In some cases so few nearly typical examples are available 

 that the measurements given may not represent the normal range 

 of individual variation, and too broad generalizations, therefore, 

 should not be based on them. 



The external measurements, unless otherwise stated, were taken 

 in the flesh by the collector, as follows: 



Toial length. — Nose to end of terminal tail vertebra. 



Tail vertebrae. — Upper base of tail to end of terminal vertebra. 



Hind foot. — Heel to end of longest claw. 



The following cranial measurements were taken with a vernier 

 caliper by the author: 



Greatest length. — Length from anterior tip of premaxillae to supra- 

 occipital in median line over foramen magnum. 



Condylobasal length. — Length from anterior tip of premaxillae to 

 posterior plane of occipital condyles. 



Zygomatic breadth. — Greatest distance across zygomata. 



Interorbital breadth. — Least distance between orbits. 



Least width of palatal shelf. — Width between outer sides of palate 

 at constriction behind posterior molars. 



Maxillary tooth row. — Distance fi'om front of canine to back of 

 posterior molar at alveolar border. 



Crown length oj upper carnassial. — Greatest length of crown of upper 

 carnassial along outer side. 



Crown, width of upper carnassial. — Greatest transverse diameter of 

 crown of upper carnassial. 



COLORS 



Owing to the banding of the individual hairs, raccoons present 

 coarsely blended colors difficult to segregate. For this reason very 

 limited use has been made, in quotation marks, of names of colors 

 from Ridgway's "Color Standards and Color Nomenclature, 1912." 

 In the description of colors generally understood, modifying or com- 

 parative terms have been employed in naming tones, many of which 

 are not well defined. 



SPECIMENS EXAMINED 



Specimens examined, unless otherwise indicated, are in the collec- 

 tions of the United States National Museum, including the Biological 

 Surveys collection. 



