466 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.59. 



Male. — Jaws always dusky; plastron always distinctly concave 

 in the median line toward anterior margin of femorals; mandibular 

 stripe nearly or quite lacking (developed in one specimen) ; throat 

 sparsely or rarely densely speckled with yellow, the specks never 

 (except in one specimen) aggregated forward into a blotch; tail 

 averaging 36.8 mm. long, its preanal length averaging 12.7 mm.; 

 supra-auricular streak little developed (except in one specimen) ; 

 anterior portion of crown usually immaculate (with one or two spots 

 in one-third of the specimens) . 



Female. — Jaws always pale yellow; plastron never concave pos- 

 teriorly along midline, sometimes somewhat depressed transversely 

 in the region of the femorals; mandibular stripe always conspicuous; 

 throat always streaked and spotted with yellow, this developed 

 anteriorly into a blotch; tail averaging 29.6 mm. in length, its preanal 

 length averaging 5 mm.; supra-auricular line usually well developed; 

 anterior portion of crown with several yellow spots. 



The single specimen in the series of 60 adult or subadult specimens 

 examined which provides an exception to some of the more important 

 characters listed is a male (Cat. No. 51785, U.S.N.M.), collected in 

 Fairfax County, Virginia, June 29, 1914, and presented by Mrs. E. P. 

 Miller. In this specimen the characters of plastron, tail, jaw color, 

 and lack of spots on anterior portion of crown are normal for the 

 male. The throat markings and mandibular and supra-auricular 

 stripes, however, are those of the normal female. Dissection of the 

 specimen showed nothing abnormal in the genital organs, and the 

 cause of its peculiar coloration can onty be assumed to be due to 

 some abnormality in its embryonic history. 



Another apparent exception to the constancy of the characters 

 above described is furnished by the excellent colored plate 5 of this 

 species published in Babcock's memoir on the turtles of New Eng- 

 land. The colors of the carapace in this plate were taken from th< 

 shell of a Massachusetts specimen, while those of the soft parts, 

 which agree with those described above as characteristic of the 

 female, were copied by the artist, R. Deckert, from " a live male 

 captured in New York City." Doctor Babcock writes me with 

 regard to this illustration that he sent a fine shell in his possession 

 to the artist "with instructions to draw the soft parts from a male 

 as nearly the same size as possible. He evidently drew from a 

 female . . ." 



It is a curious fact that not one of the fairly conspicuous and con- 

 stant sexual differences in coloration of Clemmys guttata has pre- 

 viously been recorded, although sexual differences in the shape of the 

 plastron and position of the anal opening in this and other turtles 

 have long been familiar to herpetologists. Indeed, beyond the slight 



s Mem. Boston Soc. Nat. Hist., vol. 8, pi. 27, figs. 1, 2, 1919. 



