Cope. } 84 [July 20, 
marginal sutures are of about equal length. The vertebrals are all longer 
than wide, and of the usual form, with truncate antero-lateral angles, ex- 
cepting the first. This one has both the sides and extremities convex, the 
latter being of subequal width. The costals are thick, and have parallel 
borders. The marginals are all higher than long, especially those of the 
bridge. 
The sutures of the plastron are fine and straight. The portion of the 
mesosternum enclosed by the episternal or clavicular bones has greater 
longitudinal extent than the part embraced by the hyosternals. The su- 
tures with the clavicular bone are nearly straight, and are parallel with the 
free border. The common suture of the hyosternals is a little longer than 
that of the hyposternals, and is a little shorter than that of the post- 
abdominals. The anterior suture of the latter has a slight posterior ob- 
liquity, and is abruptly turned backwards at the free borders of the lobe. 
The dermal sutures of the carapace are mostly obliterated. Enough re- 
mains to show that the second vertebral was wider than long, while the 
nuchal shield is considerably narrower than the nuchal bone. The mar- 
ginal scuta are much narrower than the marginal bones, and become nar- 
rower forwards. The region of the nuchal marginal is obscure. 
Measurements. M. 
Length of carapace to the posterior border of seventh 
COS oscars iach cu ate eloteges soko ate aay eie naels craton inners .250 
Depthvat third vertebral bones. oem ecriceier- se eereterere .150 
Length of second vertebral bone..............-. saa OS! 
Wacclthiayte FS ui ep Tereearhets lal aisle atakA ss vs 032 
Thickness s “ Cora te ree b ome ya) oy eiehers cs (ors ore -013 
Length of first marginal ers siete apa tease tte aers 035 
Wacdthie ° sf GOTTA Seuaitors Se 2 tase Chavens teens .033 
Genethiotirstido: oftheibnidiees eee ets eet .028 
Widthes:: a me bial Pye ES AMES = eat ev aera a ine .060 
Widthvof secondicostall yen eemee ieee teeer ater .033 
Thickness of ‘ Ha mero canoe Sosa Hoa oeu aes ouoac .012 
Greatest widthiof ‘carapaGese ease sere eee eee .182 
Henethxor plastrom|(@xdall) yee reer ald 
ye (anberorlobe (axial) atest teeter eter 073 
se £f MOStENIOR JOE ss say poeaasede Mowers: orate O70 
Width of base of anterior lobe........... PYAAR Le OA lalla) 
i a posterior: “4 Ae x frsenehcereiste chet rietecoiete .086 
henothvofibridee +5 0i2%, Avis ce ha ssteisiee oat eee eens .090 
e Shull eremsos oso ah aosacasdcumesooas .042 
Width “ WEEE OCG Ee AoC Ob at BAC nea Cane 046 
eenoth Of Clawicle iva. «cosine ersec ee Ce ae ere 051 
oy common suture of claviclesnee-e-enane = seer .014 
ie oe ay ECON CaaS Godordgooon Hl 
a a i Les Shi pOsvennailsiyrertereretae 047 
Width of postabdominals at anterior border........... £057 
The shell of this species is thicker than in any species of tortoise now 
living in North America, a peculiarity characteristic of most of the species 
of the Cretaceous period, and of many of those of the Eocene. Its size is 
about that of the Pseudemys serrata. 
