242 
TERTIAllY VERTEBKATA OF THE FATCtM. 
next tootli ijim. 3) is separated l)y an interval of about 6 cm, : it is likewise two-rooted, 
and is niiicli larger than 'pm- 2 ; it can be seen that the posterior border of the crown 
had a t least three accessory denticles, of which the uppermost is the largest ; the summit 
of the crown is broken away ; the antero-posterior width is (j'2 cm. The next tooth 
(/uu. 4) is almost in contact with jmi. 3, to which it is closely similar in form; its 
antero-posterior diameter is G‘2 cm. Immediately behind ]>m. 4 come three closely 
crowded molars, which differ from the premolars in having no accessory denticles 
on the anterior border and only one or two on the posterior. These teeth increase 
in size from before backwards, the last having an antero-posterior width of 4‘5 cm. ; 
they are so closely crowded that the hinder border of the penultimate fits into a groove 
on the front of the last. Beneath the molars the depth of the mandible increases very 
rapidl}", so that they are arranged in a steeply slojiing line. 
Mr. Beadnell records the discovery in beds of Birket-el-Qurun age, and associated 
with remains of Prozeuglodon, of a large nearly complete skull measuring 116 cm. 
in length. This may belong to either Fraas’s species Kocetus schweinfurtln or to the 
jiresent form ; but, judging only from a rough photograph by ]\Ir. Beadnell of the 
occipital surface of this skull, it seems that the former alternative is the more likely, 
since the breadth of the supraoccipital region a})pears to be greater than in Zevglodon 
projier. 
The following specimens are provisionally referred to this species : — 
C. 10019. A number of posterior lumbar and anterior caudal vertebra} of large size. Of these, two 
are from the lumbar region (see text-fig. 79) and are closely similar fo those of Z. macro- 
xjioiidjlus, figured by J. M tiller * on his pi. xv. The ends of the centrum are oval in 
outline, and in each case the epi])hysis has been lost. The ventral surfiice is convex from 
side to side, i)articularly near the posterior end; in the middle is a depression into which 
a pair of vascular foramina open. The transverse processes are fairly large and project 
forwards and downwards; they are strongly flattened from above dowmwards ; on their 
upper surface is a ridge which gives them the a}>pearance of consisting of outer and 
inner elements, thoutih in section this is found not to be the case. Above the base of 
the transverse processes the side of the centrum is concave. The neural arch, which 
occnjiies al)out half the total length of the centrum, is situated towards its anterior 
end ; it is very low, and the floor of the neural canal is concave both from side to side 
and from before backwards ; at the bottom of the concavity there is a, large vascular 
foramen. Anteriorly the arch bears a pair of large quadrate metapophysial processc's, 
but neither the anterior nor the posterior zygapojihyses are devclopeil ; the j)ost(n'ior 
]iart of the arch beai’s a low neural spine and is ])roduc(Hl back in the middle line 
inio a blunt ])oint overhanging the ]) 0 .sterior o|iening of the neural canal. In another 
specimen, apparently a little iurther back in the s('ri(‘s, there is a deep notch lor tlu' 
))assage of a vessel on the anterior border of the ti'ansverse process. Furtlu'r back 
still In the caudal region this notcdi is converte<l into a foramen ])erl orating the base of 
the |)rocoss. In the caudal region the metajiophyses become very large and massive 
* ‘ Ueber die fossilen Eeste der ZeUj;loduuteii von Nordamerica ’ (Berlin, 184'J). 
