148 MEMOIRS OF THE CARNEGIE MUSEUM 
ransverse diameter Ol CONG YLe en sawcamece seman paisenccraementasisner oe ienenepts ese eases 5 mm. 5 mm. 
ILGHYAAN OL CHESTENIE  oonsoc osonsanbobp9opScocaDUaDORUBLAGED ScUBEODETCLSES sneacsscosseOsIbOCEeDIa09R: 16 uf 16 
Inferior Dentition. 
Length of incisor from alveolar border to cutting point..............22..10 0 cesses eee eeeees 25 uy 27 v7 
Antero posterior diameter Of inCiSOr..............0+c002 ceeecs eee eeeeeteeeeee et eteeetetaereeees Dey Hineewia: 
Mransversediam eters OfsinClSOl ese sreeeececsescreeeseetees i escece seks seeee ssa beres sear eeenee Ae Dia A Diets 
Antero posterior diameter of grinding series...... ...... jeaanebosapatOs stobesbobbe Gop0onD.030 16 uy 16 oF 
Antero-postenior diameter Of Piece... -ce nec er- cence sn esemslene eens ierineelerleleelsereseer ann AND Aig) 1S 
TORN TS GHETNETEP OE ]Dzpsboscsdoouscada9s: avoq90 seconddaTbOS oEeqcEdeAEs, ceapSceedoEsaoRea9B02900R0C 4 fe 4 Me 
Antero-posterior diameter Of myz...........-..-.0.cceecceeceeceer ere seepecceccnsecssereecessenners 4 oe 4 # 
Transverse Wiameter Of Mz...............c0+se-eeenercnuerreee-eeinwscreserescrseense snpgoDons095000 4 re ARI Ties 
Antero-posterior diameter, Of My....-..-....-- .-.--ceecereeeeer eer ecrmesnneernnes sermansannscess way 3H 
SU IGNSD: CHETNEUWEE (1? Tig s-0n5sa5ee00du005 500000 paSd5u0090n5006000 oop agoancabedasOReDenoaEsgoqO0R 4 os 4 & 
Antero-posterior diameter of m, 3 By 
ADAIR, GINAINGID® O12 Mises snqsccdosecebcoacbSnosecn candusn00 Sona GecoBSHo.EREODoB =D AADeADceDeG HOD ae Of BH 
VERTEBRAL FormuLaA. Plate XIX. 
There were found, with the type (No. 1217), twenty-six presacral vertebree, the 
sacrum, and eleven caudals. The vertebral column was not interlocked, vertebra 
with vertebra, when found, but it seems reasonable, that the following formula may 
be correct : seven cervicals, thirteen dorsals, six lumbars, five sacrals, and eighteen 
caudals, assuming that the last seven vertebree are lost from the type. There are 
probably not more than seven or eight missing, to judge from the gradual tapering 
of the anterior caudal vertebree, which were found in position and continuous with 
the posterior sacral vertebree. 
The Atlas. —'The antero-posterior diameter of the atlas is smaller than that of 
Aplodontia. ‘This is especially true of the superior arch. The inferior arch is a little 
heavier than in the latter genus. The articulation for the occipital condyle is very 
similar to that of Aplodontia; it is not very deep, and occupies, perhaps, more of the 
area of the anterior face of the atlas than is seen in Aplodontia. The foramen for the 
spinal nerve enters the superior arch internally, immediately above the cotylus, then 
pierces the arch to the superior face, and again reénters it in a postero-lateral direc- 
tion. There are two posterior openings, one at the base of the transverse process on 
the lower side, and the other in the deep fissure above the articulation for the axis 
and at the base of the transverse process on the upper side. The foramen is similar 
to that of Aplodontia, but relatively smaller. In the type, the transverse process is 
complete, and is remarkable for its short and heavy character. The general aspect 
of the whole bone is similar to that of Aplodontia. 
The Axis. — The axis is rather heavy, and is conspicuous on account of the high, 
strong, and antero-posteriorly broad neural spine, which overhangs the neural canal 
