Wrighi — Xatrs mi Clrnnin/s. 



53 



" In muhlenbergi the same measurement gives for females 00-90 mm., 

 and for males 84-98. 



' With age, females of muhlenbergi show a gradual decrease in propor- 

 tional width. They are always proportionally higher than female 

 nuchalis. When small, female muhlenbergi are as broad as female 

 nuchalis, hut the adults are narrower. Thus, in females of muhlenbergi 

 the width forms 72.22 to 81.6 per cent of the length. The same ratio in 

 female nuchalis is 75.93 to 78.05 per cent. If, however, we omit the 

 smallest two muhlenbergi, leaving in our ratios only those forms over 

 79 nun., we have for muhlenbergi 72.22 to 75.08, and for nuchalis, 75.93 

 to 78.05. The height forms 44.11 to 46.66 per cent of the length in 

 female muhlenbergi, and 41.23 to 43.85 per cent in female nuchalis. The 

 height of female muhlenbergi does not seem to change with age as the 

 extremes of the above ratios are represented by the small ones. The ratio 

 of height to width for female muhlenbergi is 55.55 to 63.33 per cent, for 

 nuchalis 52.42 to 57.74 per cent, but omitting again the two small speci- 

 mens of muhlenbergi, we have for that species 59.25 to 63.33 per cent." 



The range in length of carapace of our females of C. muhlenbergi is 

 from S2-U3 mm., while in the males it is from 82-98.5 mm. In width the 

 males are from 58.5-09 mm., and the females, 01-08.5 mm. The width 

 forms 65.7-72.5 per cent of the length of our males, 73-70.7 per cent in 

 the females, and 83.8 per cent in a newly hatched young. In height the 

 males vary from 32-39 mm. and the females, from 37-39 mm. The height 

 forms 36.5-41.0 per cent of the length of our males, 39.7-47.0 per cent in 

 the females and 39.7 per cent in a newly hatched young. 



In the accompanying plate figures 1 and 2 are tracings from the original 

 description of C. nuchalis and the temporal spot appears in black in all 

 the figures. The illustrations from eleven specimens considered in this 

 paper show such variation that the shape or forking of the temporal spot 

 proves most uncertain in characterizing these forms. 



All in all it seems best to the writer to consider these North Carolinian 

 forms as C. muhlenbergi and to expect specimens in intermediate places 

 between Pennsylvania and North Carolina. The measurements of ten 

 C muhlenbergi follow: 



