HANNIBAL' — TERTIABY SIRENIANS 
239 
with seven columns and second and third molars with eight or nine 
columns^ but the collection includes a milk molar with seven or more 
columns and two milk incisors, slender unicolumnar teeth. Fragments 
of two tusks having a length exceeding twelve inches and a diameter 
of an inch and an inch and a half, respectively, were obtained. They 
were found together and it is believed that they came from a lower 
jaw that may have held four tusks. 
A second species of Desmostylus is found in Japan. In 1902, Yoshi- 
wari and Iwasak? described and figured a skull from the Miocene of 
Togari, province of Mino, which was subsequently named Desmostylus 
watasei Hay.^ It differs from Desmostylus hesperus chiefly in the 
small anterior columns and heavier enamel of the molar teeth. 
A third species occurs in the Oligocene of California and Oregon. 
In 1906 and 1911 Merriam^ announced the find of teeth and tusk frag- 
ments of an unnamed Desmostylus in southern California, the San 
Joaquin Valley, and Yaquina Bay, Oregon. He figures (1911, p. 407, 
fig. la-lb) a molar tooth from the Monterey formation north of Coal- 
inga (nw. J sec. 29, T. 18 S., B. 15 E.) which belongs to the same sec- 
tion of the genus as Desmostylus watasei. Recently Hay^ has figured 
as Desmostylus hesperus a skull and teeth from the mouth of Spencer 
Creek,®' Yaquina Bay, Oregon. The molar teeth are characterized 
by heavy enamel, small dentine cores, and slender anterior columns 
as in Desmostylus watasei but the Yaquina skull is only about half the 
size of the Japanese skull with five columns instead of eight to the first 
upper molars and a corresponding reduction in other teeth. 
Since the species is unnamed I propose to call it Desmostylus 
cymatias Hannibal, n.sp., from Cape Foulweather near where the 
Yaquina skull was obtained. . 
2 Yoshiwara, S. and Iwasaki, J.; Jour. Coll. Sci. Imp. Univ. Tokyo, XVI (6), 
pp. 1-13, pis. I--III, four text figs., 1902. 
3 Hay, O. P.; Proc. U. S. Nat. Mus., XLIX, p. 396, 1916. 
^ Merriam, J. C.; Science, XXIV, pp. 161-152, 1906; Univ. Calif. Publ.Geol., 
VI, pp. 403-412, 11 text figs., 1911. 
6 Hay, O. P.; Proc. U. S. Nat. Mus., XLIX, no. 2113, pp. 381-397, pis. 56-58, 
1916. 
® I am unable to locate Spencer Creek no available maps but it cuts an area 
of Seattle shale and Monterey sandstone which are of Oligocene and Oligocene- 
Mioceneage. Cf. Arnold, R. and Hannibal, H.; Proc. Am. Phil. Soc., LII, no. 
212, pp. 582, 587, pi. XXXVIJl, 1913. 
