38 PROCEEDINGS OF THE NATIONAL MUSEUM. von. 62. 
SQUALODON ZITTELI Paquier. 
Squalodon zitteli PaquieR, V., Mém. Soc. Geol. de France, Paris, Paleontologie, 
vol. 4, Memoire No. 12, pp.15-16, 1894 [based upon Squalodon bariensis Zittel, 
K. von (not Jourdan), Palaeontographica, Stuttgart, vol. 24, pp. 233-248, 
pl. 35, 1876-77]. 
Type specimen.—Consists of an incomplete skull and the anterior 
portions of the two lower jaws. The rostrum is in an excellent state 
of preservation with three incisors, one canine, five premolars, and 
three molars in place on the left side. Four additional molars were 
present originally as is attested by the alveolae, some of which still 
contain fragments of the roots. 
Both lower jaws are represented by the entire symphysial region 
and considerably more than the anterior half of either Jaw. The 
left mandible possesses three incisors, one canine, four premolars, 
four molars, and the anterior root of the fifth. The symphysial re- 
gion represents more than one-third the total length of either lower 
jaw. The basioccipital, exoccipitals, squamosals, jugals, and a con- 
siderable portion of both postorbital processes of the frontals are 
missing. The bones forming the vertex and the superior wall of the 
cranium are sufficiently well preserved to indicate their relations to 
one another. The type is in the ‘“ Palaeontologische Sammlung”’ at 
Munich, Germany. 
Type locality.—In the neighborhood of the village of Bleichenbach 
upon the Rott River, 2 kilometers from Birnbach, lower Bavaria, 
Germany. The specimen was obtained during the excavation of a 
high sand hill, and was found about 12 feet below the surface. 
Middle Miocene. 
GENERAL DISCUSSION. 
The squalodonts according to our present knowledge scarcely 
attained a length of 20 feet. This, however, is only an estimate 
based upon isolated vertebrae as very little is known concerning the 
skeletons of the several forms previously described. 
[t is premature in the light of available data to consider the valid- 
ity of the various genera into which the squalodonts have been di- 
vided by previous writers; this task will await the acquisition of 
more complete material. Cetologists are, however, quite aware that 
the genus Squalodon is made up of forms differing greatly in appear- 
ance, and that it is much in need of revision. 
The following key is based essentially upon data obtained from a 
careful perusal of descriptions and an extensive comparison of the 
figures of various authors. Necessarily the possibility for error is 
considerable, because in fossil cetaceans genera and species have been 
founded upon totally different parts of the skeleton, which do not 
permit comparison with one another. This renders it difficult to 
decide how many of the described forms really represent valid or 
distinct species. In the case of the shark-toothed cetaceans or 
