120 THE AMERICAN MIDLAND NATURALIST 



length, collected June 4, 1933, gave birth to 12 young September 13, 1933. 

 These ranged from 7% to 8^/2 inches in length. Both females refused all 

 food in captivity and both died a few days after the birth of the young. The 

 appearance of the juveniles in each litter was such as to indicate that they 

 were probably born a bit prematurely. Ditmars (1936, 370) gives the num- 

 ber in a brood as from 7 to 12 and the dates of birth as from September 6 

 to 18 inclusive. 



Sternotherus odoratus (Latreille) 



Musk Turtlc 



Description. — A small turtle attaining a carapace length of 5 inches or 

 more. Largest adult Ohio specimen {$), had a shell 5 inches in length; 

 smallest juvenile (probably recently hatched), % inch. Carapace rigid and 

 covered with horny plates. Shell relatively long and narrow and considerably 

 arched, the highest point lying from 459f to 659r of the length back from the 

 anterior margin. No outward flare of the shell at the edges of the carapace. 

 Scutes smooth and slightly imbricate in the young. Juveniles with a promi- 

 nent middorsal keel which gradually disappears with age. Nuchal small, occa- 

 sionally much reduced and even wanting in one specimen. Costals and verte- 

 brals normal. Marginals, including the nuchal, usually 23 (25 in a specimen 

 from Hocking County and 22 and 21 respectively in two specimens from 

 Athens County) . 



Plastron small and not nearly filling the opening of the carapace; rounded 

 anteriorly and emarginate posteriorly. Posterior lobe rigid, anterior lobe mov- 

 able on a hinge located between the pectoral and abdominal plates; hinge 

 undeveloped in young. Plastral scutes of adults and many juveniles separated 

 by areas of skin which are widest in adult males. 



Head large, snout conical, tip of upper jaw not developed into a beak. 

 Tail short and terminated by a blunt horny nail in adult males and with or 

 without a sharp horny nail in females. Skin soft and covered with fleshy 

 papillae; two to four elongate ones on the chin and two on the throat. Sev- 

 eral long curved scales on the feet. Adult males with two^-ough patches of 

 scales on the inner side of the hind legs near the knee and so arranged that 

 the two patches on the same leg lie against each other when the legs are flexed. 



Carapace some shade of dark brown, grey, olive brown or black and in the 

 lighter specimens showing streaks or spots of a darker shade more or less 

 irregularly arranged. Plastron yellowish brown, the borders of the scutes 

 darker. Soft parts grey or olive grey mottled with yellowish. Two more or 

 less well defined yellowish lines extending backward from the snout, one pass- 

 ing directly above the eye, the other below it. Lower margin of lower jaw 

 bordered with yellow. Juveniles pigmented similarly to adults but usually 

 darker and with the head markings more prominent. 



Specimens are sometimes so overgrown with algae as to have the upper 

 shell completely obscured, but when the skin of the scutes are shed this 

 growth is lost with them. 



