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Michael E. Seidel and William M. Palmer 



(quantitative) means for identifying species of Pseudemys. Thirty 

 character ratios were constructed from 27 of the original 30 characters. 

 These included character ratios that have been reported to be useful in 

 discriminating between P. concinna, P. floridana, and P. rubriventris. 

 Sexes were again treated separately. Although several of these ratios are 

 somewhat redundant and therefore strongly correlated, each was 

 examined to allow direct comparisons with previously reported values 

 (e.g. Ward 1984). Despite the theoretical problems with using ratios in 

 statistical analyses, their effectiveness in taxonomic studies of turtles has 

 been clearly demonstrated (Iverson and Graham 1990). 



We also examined large series of hatchling and juvenile P. 

 rubriventris, P. floridana, and P. concinna. Young individuals were very 

 difficult to identify. Characters that we found to be diagnostic in adults 

 of these species were either impossible to resolve in young turtles or 

 extremely variable, even within a single brood of hatchlings. 





oo 



° * .8 o 



O 



PC II 



Fig. 8. Plot of individual adult male Pseudemys based on principal components 

 analysis (PC II) and discriminant function analysis (DF 1) of morphometric 

 characters (see text). Open circles represent P. rubriventris, closed circles 

 represent P. concinna, and triangles represent P. floridana. 



