ALLEN — FOSSIL CETACEANS FROM FLORIDA 
155 
with well developed, functional teeth in the upper as well as in the 
lower jaw. On a subsequent page of the same paper, Lydekker, evi- 
dently through inadvertence, calls the genus Paracetus, but Hypocetus 
has page priority. This paper, though bearing date 1893, was actually 
issued in April, 1894, and is, therefore, later than a paper by Ameghino 
dated February, 1894, in which the generic term Diaphorocetus is ' 
proposed for the same specimen and thus has priority (see Palmer, 
Index Gen. Mamm., 1904, p. 341). A further difficulty in the specific 
reference lies in the fact that it is not clear whether Copers species 
mediatlanticus really differs from Moreno’s poucheti. The type of the 
latter is a fairly well preserved skull lacking the jaw, from Bahia Nueva, 
Chubut Territory, Patagonia, found in a formation which Ameghino 
believed to be of Eocene age, but which is now considered to be lower 
Miocene (True, 1910, p. 31). Cope’s type of mediatlanticus is a large 
fragment consisting of the base of the rostrum with the alveoli of the 
proximal seven or eight pairs of maxillary teeth, and parts of the in- 
termaxillaries, vomer, and adjacent bones. It is from the St. Mary’s 
formation at Drum Point, Maryland, now regarded (Cushman, 1920, 
table opp. p. 40) as of upper Miocene age. Cope attempts no compari- 
son of his specimen with Moreno’s poucheti, beyond the statement that 
the two are ^‘not distantly related.” From Case’s figure of the type, 
however, it appears that the alveolar row extended back only to the 
level of the middle of the vomer, whereas, in Moreno’s figure (1892, 
pi. 10) of poucheti, indications of alveoli seem to continue considerably 
posterior to the vomer. A slight difference in the outlines of the pala- 
tal bones is also seen, but how far these differences are individual 
rather than specific must await the discovery of additional specimens. 
It therefore seems best to retain Cope’s name mediatlanticus for the 
present and to refer the Florida fragments provisionally to it. A 
description of these follows. 
(1) The finest specimen of all is the fragment of rostrum figured by Sellards 
(1915, p. 103, fig. 32), as the ‘‘side view of upper and lower jaw of another ceta- 
cean.’’ It is shown at about one-half natural size and was 300 mm. long, compris- 
ing a portion of both jaws broken from slightly in advance of the symphysis. It 
obviously includes some of the posteriormost of the teeth. Its upper profile 
is, nearly plane with a line parallel to it marking the suture between maxillary 
and intermaxillary. The ventral outline of the lower jaw shows the distinct 
angle at the beginning of the symphysis so characteristic of the sperm whales. 
Posteriorly from this angle the teeth of both jaws at once show a successive dimi- 
nution in size, while in advance of it they are all of a nearly uniform size and 
