Status of Geomys cumberlandius 143 



colonus has been shown by Laerm et al. (in press) and Williams and 

 Genoways (1980), on the basis of morphometries, electrophoresis, 

 karyology, and mitochondrial DNA sequence relatedness, to be syn- 

 onymous with G. pinetis. Twenty-one body and cranial measurements 

 were taken to the nearest 0.01 mm with dial calipers. These included: (1) 

 total body length, (2) tail length, (3) hind foot length, (4) condylobasilar 

 length, (5) zygomatic breadth, (6) mastoid breadth, (7) palatal length, 

 (8) palatal depth, (9) rostral breadth, (10) maxillary tooth row length, 

 (11) least interorbital constriction, (12) braincase breadth, (13) nasal 

 length, (14) greatest anterior nasal breadth, (15) breadth of nasals at 

 narrowest point, (16) greatest posterior nasal breadth, (17) interptery- 

 goid fossa length, (18) auditory bulla length, (19) breadth of ascending 

 ramus of maxillary, (20) anterior palatal breadth, and (21) posterior 

 palatal breadth. All measurements except variable 20 were made using 

 the methods of Williams and Genoways (1977) and DeBlase and Martin 

 (1974). Variable 20 was measured across the greatest width of the 

 ascending arm of the maxillary. 



It has been well established that body and cranial measurements 

 change during the growth of an individual, but usually not at a constant 

 rate. It is, therefore, frequently desirable to compensate for size varia- 

 tion due to sex and age before comparisons are made. This is particu- 

 larly true in cases where small sample sizes limit the value of assigning 

 each individual to separate sex and age classes as in the present case. 

 This has commonly been done with proportions or transformation of 

 proportions; however, controversy has recently arisen over the use of 

 these techniques (Atchley et al. 1976; Albrecht 1978; Atchley and An- 

 derson 1978; Dodson 1978; Hill 1978). Fortunately, a number of statis- 

 tical techniques are available that permit compensation for the effects of 

 size without using proportions. We chose Analysis of Covariance using 

 SAS procedures (Barr et al. 1976) to determine if significant differences 

 could be detected between G. cumberlandius and widely separated pop- 

 ulations of G. pinetis. Males and females were treated separately 

 because of obvious sexual dimorphism. A Multiple Discriminant Func- 

 tion Analysis (SAS) was performed on raw data, separated into male 

 and female groups to obtain generalized distances between populations. 

 These were then clustered by UPGMA (Sokal and Sneath 1973) into 

 distance phenograms to graphically illustrate phenetic distances between 

 populations. 



RESULTS 



Initial tests of equal slope in the Analysis of Covariance used the 

 following model: 



V4 (condylobasilar length) 



population 



V4 X population. 



