THE OSTEOLOGY OF ELOTHERIUM. 295 
other hand, increase in size and on the (?) fifth vertebra they curye toward each 
other, almost meeting and enclosing a canal, which continues as far back as the (?) eighth 
vertebra, behind which the hemapophyses are again reduced. The middle portion of 
the tail is composed of very long, cylindrical vertebree, which in shape strikingly 
resemble those of the great cats, and which are proportionately much longer, though 
apparently less numerous than those of Anoplotherium. At the anterior end of each 
vertebra are six prominent, nodular processes, the zygapophyses, transverse processes and 
hemapophyses respectively. Posteriorly the centra become more and more slender, but 
are not much diminished in length, for what appears to be the penultimate vertebra is 
nearly as long as those in the middle region. The various processes are, however, 
reduced to yery insignificant proportions. The last vertebra has its anterior portion 
shaped like that of its predecessor, but it rapidly tapers behind to a smooth, slender, 
compressed and subeylindrical rod, with a club-shaped thickening at the end. As I have 
seen but a single specimen of this curious vertebra, I cannot feel quite confident that its 
shape is a normal one and not due to some injury or morbid process. 
The tail of Hippopotamus is of about the same relative length as that of H/othe- 
rium, but the individual vertebree are very different, being all shorter and heavier, and 
diminishing in size more gradually to the end. In Sus the caudal vertebrae are somewhat 
more like those of Hlotherium, but none of them have such slender elongate centra. Little 
is known concerning the caudals of Anthracotherium. Kowaleysky says of them: ‘“ Von 
den Schwanzwirbeln liegt mir nur ein einziges yor. Obwohl seine Erhaltung sehr 
mangelhaft erscheint, kann man doch aus diesem kleinen Sttick den Schluss ziehen, dass 
der Schwanz bei den Anthracotherien kurz war und somit gar keine Aehnlichkeit mit 
dem sonderbar langen Schwanze der Anoplotherien hatte” (73, p. 333; Taf. x, Fig. 36). 
The vertebra described by Kowaleysky is an anterior caudal and is much smaller and in 
every way more reduced than the corresponding ones of Elotherium. Among existing 
artiodactyls, it is the giraffe which most resembles the White River genus in the peculiar 
character of its caudal vertebre. 
Measurements. 
ENE Sp TORE, copsascs coocconan soxsco Spo euESgONDNSSESOSOCOOIS OOSCOIUSOHODOSOND SenocasoosnosecONSeDcCeN CONOR boxeCes 0.160 
JNTES, ERGRTIESE TAGLUTR. .. cononeoconscecoenabaosbsanSodosesuSeCCESoONdAN=dos poSSoRHNSsHeanccOOSSCEGHSOAENSSUECHSAOOH J 270 
Axis, length GT GST TIT aces AOR Gn ECBO CCD NEC OOOH ERE EEE Boa nicsaaa2 Saccon OO pao Dodo SEER TSC IaA EAC ICRU eee Se 085 
ANSE), TGTIRUE ©? OOM OTT ococaconsosscospesgoSoSHESORCoceTRESeoO NcbSoOSHNSSSKOeOOIES SoEeoSSoecanOAbTSIoDIEONS! GOSH. 6 026 
Ata Sm anite nl OmMbread uhisascessonnesessncdnecct sec natacacsncscisercanceusenterte se netes seneaeoesemareesnecacaceeaaes -109 
JASSS,, POOSHSHIOW | TENN hens concd ccqsonaoadosSuaNsscn5 005095 coscDONSOnoHOSOSURsaSno SondES SsancosEpSRaNSccODONDSSoOOS 054 
Third cervical, length 
Seventinice nyaea lee en pstihveseetssesecenta reese neenanedee ca elene a eeeenertereneee eee nominee anne ea ter eenenee eens .056 
TRY TIRGREO KE, LIGLEVE Nace coccescosocteoncdecbe BO ACBOSBECEDABREDSECOATIASE C90: SOSCREEIE HONE EIRE TOSI COSEADOQUOOSES! & 051 
KD SSO, cade Wve 
