6 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62. 
that this form is quite unlike those specimens referred to the genus 
Neosqualodon. The general appearance of these small teeth, including 
the presence of coarse striae at the base of the enamel crown of the 
molar as well as the compressed crowns of the premolars, !° suggest a 
closer relationship with Squalodon than with Neosqualodon. Since it 
does not belong to any previously described genus, it may hereafter 
be known as Microcetus ambiguus (Meyer). 
SQUALODON ANTVERPIENSIS Van Beneden. 
Squalodon antverpiensis VAN BENEDEN, P. J., Bull. Acad. Roy. Sci., des Lettres 
et des Beaux-Arts, Bruxelles, ser. 2, vol. 12, No. 7, p. 28, 1861; Mém. Acad. 
Roy. Sci. Belgique, Bruxelles, vol. 35, pp. 14-43, pl. 1, 1865. 
Type specitmen.—Consists of the major portion of a fragmentary 
rostrum with teeth in situ—that is, three premolars and seven molars. 
This species has a long symphysis, as is shown by the two fragments 
of the mandible belonging to the type. Additional material provi- 
sionally assigned to the species includes several cervical vertebrae, a 
clavicle, humerus, cubitus, and phalanx. Type in the ‘‘ Musée Royal 
d’Histoire Naturelle de Belgique,”’ at Brussels, Belgium. 
Type locality.—Fort No. 4, at Vieux-Dieux, in the vicinity of 
Antwerp, Belgium. The type comes from the “Sables inferieurs 
d’Anvers” which according to Abel" are referable to the Bolderian 
or Upper Miocene. 
Subsequent allocation.—A few years later Van Beneden” described 
and figured a portion of the symphysial region of the lower jaws of 
a second squalodont derived from the deposits around Antwerp. 
This specimen possesses premolars exhibiting sawlike cutting edges 
and the enamel crowns of the teeth are fluted or ornamented with 
large coarse striae similar to the ornamentation on the incisors of 
the type specimen. On the whole there is considerable resemblance 
between the teeth of the two specimens, and Van Beneden was un- 
doubtedly right in referring them to the same species. 
The descriptions and figures of Van Beneden are probably inexact 
in many respects for several discrepancies are to be observed in the 
account as given by Abel and as drawn up by Van Beneden. 
NEOSQUALODON ASSENZAE Dal Piaz. 
Neosqualodon assenzae Dat Praz, G., Abhandl. Schweiz. Paliont. Ges. Geneve, 
vol. 31, No. 5, pp. 1-19, with 1 pl., figs. la, 1b, 2, 3a, 3b, 4a, 46, 5a, 5b, 6a, 6b, 
1904. 
Type speciomen.— Consists of a posterior fragment of the rostrum 
(the tip of rostrum and the brain case posterior to narial openings 
10Meyer, H. von, Beitrige zur Petrefacten-Kunde, vol. 3, pl. 7, figs. 4a, b; 5a,b, 1840. 
ll Abel, O., Mém. Mus. Roy. Hist. Nat. Belgique, Bruxelles, vol. 1, p. 42, 1901; vol. 3, p. 50, 1905. 
12Van Beneden, P. J.. Mém. Acad. Roy. Sci. Belgique, Bruxelles, vol. 37, pp. 1-13, pl.—, figs. 1-2, 
1868. 
13 Abel, O., Mém. Mus. Roy. Hist. Nat. Belgique, Bruxelles, vol. 3, pp. 47-50, 1905. 
