THE GEOGRAPHIC TURTLES. 83 
PLATE II. 
EXl'I-ANATION OF TIIK I'lGURKS. 
Fig. 1. — Outline showing slope of carapace iu youug M. lesucuri. 
Fig. 2. — Same of young M. geographicus. 
Fig. 3. — Same of adult 31. lesueuri. 
Fig. i. — Same of adult M. geographicus. 
Fig. 5. — Ventral side of skull of M. geographicus ; mx, maxilla; v, 
vomer; jil, palatine bone. 
Fig. 6. — Ventral side of skull of M. lesueuri with same bones out- 
lined. 
Fig. 7. — Ventral side of skull of rseiulemys elegans, for comparison 
with Figs. 5 and G. 
Fig. 8. — Right side of skull of M. lesueuri, dorsal view; vix, max- 
illa; ns, naso-prefroutal ; fr, frontal; pfr, post-frontal; p, 
parietal. 
Fig. 9.— Same of 31. geographicus, showing diflereuce, especially Ite- 
tween the frontal bones. 
Fig. 10. — Right ramus of mandible of an adult 31. geographicus. 
Fig. 11. — Same of an adult 31. lesueuri. 
Note. — The observations of which the above is the result were 
made at odd times Avhilc connected with the Illinois State Laboratory 
of Natural History and are based chiefly on material collected by the 
writer in the Mississippi and Ohio rivers and their Illinois tributa- 
ries, but partly also on specimens collected or examined elsewliere in 
the United States. 
