Giles: Multivariate Analysis of Pleistocene and Recent Coyotes 379 



unsexed specimens added to a group of known composition was kept within the 

 95 per cent limits, assuming the extreme case that the unknowns were all of one 

 sex. Such a procedure kept all the Recent samples comparable to the samples from 

 Rancho La Brea. 



MEASUREMENTS 

 Following experimentation, and consideration of the observations of Jackson 

 (Young and Jackson, 1951) and Merriam (1912), eight measurements on the 

 cranium were chosen for analysis. The mandibles were examined with two objec- 

 tives in mind: to utilize measurements that are readily available in most paleonto- 

 logical series, and to perform the analysis on the basis of as few dimensions as 

 possible, thus reducing statistical manipulation. Only five measurements were 

 taken on the lower jaw. The total number of measurements was 3,500. 



For uniformity all measurements were taken to .10 mm. It is not presumed, 

 however, that all measurements are significant to this degree. A complete list of 

 measurements and a fuller account of the statistical procedure have been de- 

 posited in the Library of the University of California, Berkeley (Giles, 1956b). 



The following measurements were used: 



Palate-occipital condyle length (POc). — From the posterior border of the 

 palate to the most posterior surface of the occipital condyles parallel to the mid- 

 line. 



Length of the maxillary tooth row (MxT). — From the premaxillary-maxillary 

 suture on the labial edge of the alveolar border to the posterior edge of the bony 

 tooth row behind M-. 



Least breadth of the rostrum (LBR).— Breadth of rostrum taken at its least 

 dimension, usually between P 1 and P-. 



Bizygomatic breadth (BzB). — Greatest width of the zygomatic arches. 



Interorbital breadth (InB). — Least breadth between the orbits anterior to the 

 postorbital processes. 



Frontal height, anterior (FHA). — Measured from the surface of the palate to 

 the juncture between the nasal bones and the frontals in the mid-line, and per- 

 pendicular to the long axis of the skull. 



Frontal height, posterior (FHP). — Measured from the frontoparietal suture 

 (avoiding any sagittal crest) to the ventral surface of the postsphenoid, perpen- 

 dicular to the long axis of the skull. 



Fourth upper premolar length (P 4 L) . — Length of carnassial blade on the labial 

 side of the tooth, including the cingulum. 



First lower molar length (M T L). — Taken from the anterior edge of the carnas- 

 sial blade to the cingulum posterior to the hypoconid. 



First lower molar breadth (M^B). — Breadth taken just anterior to the meta- 

 conid. 



Mandibular tooth row (MnT). — The length of the mandibular tooth row meas- 

 ured from the posterior edge of the M3 alveolus to the anterior edge of the canine 

 alveolus. 



Horizontal-ramus depth (HRD). — Measured from the anterior part of the 

 lateral edge of the M T alveolus to the inferior surface of the mandible, perpen- 

 dicular to the axis of the horizontal ramus. 



