108 Michael E. Seidel and William M. Palmer 



was noted. These identifications often agreed with specific assignments 

 in museum collections, although many specimens from coastal Virginia 

 and North Carolina are catalogued as "Pseudemys sp?" or only 

 tentatively assigned to species. 



Character states for 15 qualitative characters were recorded for 

 each turtle. Twenty-six shell characters were measured on each specimen 

 with calipers (Helios) or a goniometer (Jamar). Two head-neck stripes, 

 head width, and maxillary cusp length were also measured. These 30 

 measurements (Fig. 2-7) included all quantifiable external characters 

 that have been used to diagnose P. concinna, P. floridana, or P. 

 rubriventris, as well as additional characters suspected to have taxonomic 

 value: carapace length along midline (CL), carapace width at sulcus 

 between marginals V-VI (CW), carapace width at sulcus between 

 marginals VII-VIII (SW), plastron length along midline (PL), shell 

 height at sulcus between vertebrals II-III (CH), shell height at sulcus 

 between vertebrals III-IV (SH), cervical scute dorsal length (CS), cervical 

 scute dorsal posterior width (CD), cervical scute ventral length (CU), 

 cervical scute ventral posterior width (CV), marginal XII length (MH), 

 marginal XII anterior dorsal width (MA), marginal XII posterior 

 (ventral) width (MP), lateral angle of carapace formed by dorsal and 

 ventral surfaces of marginal VI (SA), posterior angle of carapace 

 formed by midline slope of vertebral V and midline sulcus of anal scutes 

 (PG), anal notch depth (AN), length of interfemoral sulcus (IL), shortest 

 distance between inguinal scute and pectoral-abdominal sulcus (IE), 

 anterior plastral lobe width (PW), posterior plastral lobe width (XW), 

 taper of anal scutes measured as the angle formed by posterior extension 

 of lines along the lateral edge of the anal scutes (AA), epiplastron 

 thickness at mid-humeral scute (ET), depth of epiplastral lip measured 

 as the distance between the anterior tip of the intergular sulcus and a 

 line formed by resting a straightedge across the dorsal epiplastral lip 

 (EP), cervical scute recession measured from anterior tip of cervical 

 scute to a straight line along the anterior tip of first pair of marginals 

 (NR), ventral extension of posterior carapace measured from posterior 

 tip of interanal sulcus to posterior edge of vertebral V (AV) and to 

 posterior tip of intermarginal XII sulcus (AP), head width at anterior 

 margin of tympanum (HW), length of cusps on upper tomium (LC), 

 greatest width of supratemporal stripe (SS), and width of post- 

 symphyseal (ventral) stripe at level of tympanum (GS). 



For multivariate analysis, only turtles with a midline carapace 

 length > 120 mm were included, and males and females were analyzed 

 separately. That reduced the effects of ontogenetic and sexually 

 dimorphic character variation, which may be pronounced in Pseudemys 

 (Iverson and Graham 1990). Principal components analysis (PCA-SAS; 



