A NEAKLY COMPLETE SHELL OF THE EXTINCT TURTLE, 

 TRACHEMYS SCULPTA 



By Charles W. Gilmore 

 Curator of Vertebrate Paleontology, United States National Museum 



INTRODUCTION 



A nearly complete articulated carapace and plastron of an Emjdd 

 turtle, discovered in 1928 by Dr. J. W. Gidley in Pleistocene deposits 

 in the vicinity of Melbourne ("Golf Course locality"), Brevard 

 County, Florida, appears to be referable to the little known Trache- 

 mys sculpta Hay. In being the most perfectly preserved specimen yet 

 found of this species, it contributes much to a better understanding of 

 the skeletal anatomy and is, therefore worthy of the detailed descrip- 

 tion that follows. 



TRACHEMYS SCULPTA Har 



Plates 1, 2, and 3 



The type specimen upon which the above species was established 

 consists of a complete nuchal bone, from the Pleistocene of HUlsboro 

 County, Florida, 



In the original description ^ Hay provisionally associated with 

 the t3^pe specimen certain other parts of the carapace, none of which 

 is known to pertain to the same individual. Subsequently other 

 scattered bones of the carapace were described ^ by the same 

 authority. It is obvious, therefore, that it is the nuchal bone alone 

 that must be relied upon to furnish the characters which distinguish 

 Trachemys sculpta from the other species of the genus. 



The identification of the present specimen (Cat. No. 11839, U. S. 

 N. M.) as belonging to T. sculpta rests upon the similarity in size, 

 proportions and other features of the nuchal bone with the type. 

 The broad rounded carina within the area of the first vertebral; the 

 long narrow nuchal scute that is raised into a strong ridge; deeply 

 sunken sulci and similarity in the sculpture of their dorsal surfaces 

 these two bones are in full accord. 



I am aware of the fact that some herpetologists no longer regard 

 Trachemys as a valid genus but include its species under the genus 



'Hay, 0. P., Fossil Turtles of North America, Carnegie Institution of Washington, 1908, p. 351, pi. 54, 

 figs. 4-9. 

 2 Eighth Ann. Rept. Geol. Surv. of Florida, 1916, pp. 68-70, pi. 7, figs. 8-10. 



NO. 2833.— Proceedings U. S. National Museum, Vol. 77, Art. 10 



93847—30 I 



