17. KINOSTERNID^ 



ous. Captive specimens ate meat voraciously, under water. 

 The Tucson specimens were caught with hook and line baited 

 with meat. 



223. Kinosternon flavescens (Agassiz) 

 Yellow-necked Mud Turtle 



Platythyra flavescens Agassiz, Contributions Nat. Hist. U. S., Vol. I, 



1857, p. 430 (part) (type localities, Texas, Arizona), Vol. II, 



pi. V, figs. 12-15. 

 Cinosternum flavescens Copf, Bull. U. S. Nat. Mus., No. i, 1875, p. 52 



(part); Coues, Surv. W. looth Merid., Vol. V, 1875, p. 590, pi. 



XVII; True, Bull. U. S. Nat. Mus., No. 24, 1883, p. 31 (part); 



BouLENGER, Cat. CheloH. Brit. Mus., 1889, p. 40; Cope, Proc. 



Acad. Nat. Sci. Phila., 1893, p. 386; Brown, Proc. Acad. Nat. Sci. 



Phila., 1903, p. 543; SiEBENROCK, SB. Akad. Wiss. Wien, Vol. 



CXVI, 1907, p. 568, fig. 6; DiTM.\RS, Reptile Book, 1907, p. 25, 



pi. XI; SiEBENROCK, Zool. Jahrb., Suppl. 10, Heft 3, 1909, p. 443; 



Strecker, Baylor Bulletin, Vol. XVIII, No. 4, 1915, p. 10. 

 Kinosternum flavescens Cope, Proc. Acad. Nat. Sci. Phila., 1892, p. 22?,- 

 Kinosternon flavescens Stone, Proc. Acad. Nat. Sci. Phila., 1903, p. 540; 



Ellis & Henderson, Univ. Colorado Studies, Vol. X, No. 2, 1913, 



p. 1 14; Stejneger & Barbour, Check List N. Amer. Amph. Rept., 



1917, p. III. 



Description. — Shell rather narrow, elongate, somewhat 

 depressed, smooth. Vertebrals five, usually longer than 

 broad. Costals four, first longest, second and third highest, 

 last smallest. Nuchal narrow. Marginals 1 1 on each side, 

 ninth with superior border much elevated anteriorly, supra- 

 caudals not united. Plastron large, extending forward about 

 as far as carapace, its central region covered by the abdominal 

 plates united to carapace by a strong bridge. Anterior por- 

 tion of plastron hinged, capable of closing shell when head 

 and limbs are redrawn. Gulars partly or completely united 

 into a single plate. Pectoral median suture short. Abdomi- 

 nal and anal sutures longest. Axillary and inguinal plates 

 elongate, separating abdominal from marginals. Head rather 



