TEl{TIA]iY A^EETEBEATA OF THE FAT^M. 
1^34 
l:irp;c ])ost(M'()-oxteriKil cusp. The talon is of inoderate size, and its outer border is high 
and forms a cutting-edge; it is separated from the much lower inner border by a 
slightly concave surface, which is homologous with the basin-shaped depression of the 
talon in the other species. On the antero-external angle of the tooth there is a well- 
marked tubercle (stylid) belonging to the cingulum, which is wanting round the rest 
of the crown. 
The dimensions of this specimen are : — Length, so far as preserved, 4'G cm. ; depth 
of ramus beneath in. ‘i, 1'6 cm. The lengths of the teeth are: — pm. 4:, 8 mm. ; 
rn. 1, (3’5 mm.; m.2, 8'5 mm. ; 3, 11 mm. 
M. 9260. Plaster cast of the above specimen. Made in the British Museum. 
Order CETACEA. 
Suborder ARC II ^OGETI. 
Earaily ZEUGLODONTIDvE. 
Facial region of skull greatly elongated ; external nares opening comparatively far 
forwards ; nasal canal prolonged backwards by the union of tlie maxillae, palatines, and 
])terygoids, so that the internal nares are far back; nasal bones elongated; frontals 
forming broad supraorbital processes. Parietal region of the skull very narrow, and 
temporal fossae very large. In the earliest forms (Protocetus) the normal eutherian 
dentition seems to have been present, and the teeth behind the second premolar 
have three roots. In the later forms [Zeuglodon) the dentition is reduced, probably 
by loss at the hinder end of the series ; the anterior premolars may have one or 
two roots, but the other teeth of the molar-premolar series are two-rooted, and have 
compressed crowns with sharp serrated edges. The iieAv genus Frozcuglodon described 
below is intermediate between these two types. 
The Zeuglodonts of the Fayum are especially interesting, because the first 
mammalian bones described from this region "were })arts of the skeleton of a member 
of this family. In 1879 Schweinfurth collected some vertebne, including an axis, 
from the island Geziret-el-Qorn in the lake l>irket-el-(.Iurun : the beds in which 
these remains were found belong to the Pirket-el-Qurnn series of Peadnell, forming 
the upper part of tlie Lower Mokattam beds. The s])ecimens were described by 
Dames*, by whom they were referred to three forms: — (1) a large species with 
*- 
Sitzun^sb. k. preuss. /Vkad. Wiss. vol. i. (ISSb) p. 121). 
