240 
JOUENAL OF MAMMALOGY 
The stratigraphic range of the three species is shown in the following 
table. 
CALIFORNIA 
OREGON 
JAPAN 
Middle Miocene 
Oligocene-Miocene 
D. hesperus in San 
Pablo formation 
of Monument 
Peak near San 
Jose 
D. cymatias in Mon- 
terey formation 
north of Coa- 
linga 
D. cymatias in 
Monterey or 
Seattle forma- 
tion at Yaquina 
Bay 
D. watasei in Mio- 
cene of Togari, 
province of Mino 
EXPLANATION OF PLATES 
Plate 11 
Desmostylus cymatias Hannibal, n. sp.; Yaquina Bay, Oregon (after Hay, Proc. 
U. S. Nat. Mus., XLIX, pi. 58). 
Fig. 1. Skull from left side. Xf . Explanation of numerals: 1, supraoccipital; 
2, parietal; 3, frontal; 5, premaxillary; 6, maxillary; 7, lachrymal; 8, squamosal; 
9, zygoma; 10, jugal; 11, capsule for second molar; 13, exoccipital condyle; 
17, mastoid, 18, palatine; 27, tympanic cavity; 28, infraorbital foramen; 29, 
exoccipital. 
Fig. 2. Skull from rear. Xf. 
Fig. 3, 4. Supposed second molar. XI. * 
Fig. 5, 6. Supposed fourth premolar. XI. 
^ , Plate 12 
Desmostylus hesperus Marsh, XI; Monument Peak, San Jose, California. 
^ — Fig. 7. Fragment of a little-wom molar comparing closely to Marsh’s type. 
S'/ / ^ Fig. 8, 9. Worn second or third molar. 
'- Fig. 10. Partly-worn second or third molar from another part of mouth. 
5"/ 2. 1 —Fig. 11. Partly-worn first molar. 
S'/ -2.^. " Fig. 12. Fragment of an unworn milk molar which originally had seven or more 
columns. 
Fig. ( 13, 14. Fragments of unw'orn unicolumnar teeth, probably milk incisors. 
Stanford University ^ California. 
