292 MEMOIRS OF THE CARNEGIE MUSEUM. 
look much more strongly forward than in specimen No. 1713 and specimen No. 
1731. This forward aspect of the prezygapophyses is characteristic not only of 
this vertebra, but of all the succeeding vertebre of the dorsal series in specimen 
No. 1604, and though it might be interpreted as a possible result of age in this 
large specimen, the writer is inclined to regard it as indicating with other things a 
specific difference. It is at all events a strongly marked and constant feature. 
The postzygapophyses in specimen No. 1604, look backward and downward, 
almost imperceptibly inward; but more strongly inward in specimen No. 1713. 
The transverse process in the tenth dorsal indicates modifications in form which 
are noticeable. The articulating surface for the tuberculum of the rib is separated 
from the mass of the transverse process by a narrow sulcus which is deeper below 
than above. The mammillary process is elevated and extended forward as a sharp 
anterior projection overhanging the prezygapophyses. ‘The articulating faces 
for the heads of the ribs are widely separated and the superior margin of the pos- 
terior articulating surface for the head of the rib is strongly bent upward as a lip- 
like projection, forming a large portion of the posterior margin of the intervertebral 
foramen. In specimen No. 1713 a small posterior projection from the back of the 
lamina above is sent forth to meet this lip-like projection, so that a very large 
portion of the intervertebral foramen is enclosed within the bone of the vertebra. 
MEASUREMENTS OF TENTH DorsAL VERTEBRA.* 
mm mm. mm 
Greatest height from base of centrum to top of spine..............-.....+-+-+--+:s- 223 208 
Greatest transverse diameter measured across transverse processes. ..............0-0+ 123 109 
Greatest antero-posterior diameter measured from front of prezygapophyses to back of 
POStZYPaApPOPMYSES - oN Pe etek aust ayse eee teed Oe peRe aE IOS ne a Oe nee 84 a 
kenethyokicentrumealongsioorlofemeuralicanal laren ee eee ee ee ee 52 46 56 
enetholscentrumayalongsimienrior suite Cesena aera 48 40 52 
Vertical diametenot antertorniace) oliCentrunaess seers wre eee ee eee 48 48 52 
Mransverseidiameten om antenortace/olcenthum — eee ee rete eae 58 52 65 
Venticalidiameterotpostenonmtace ocent rune ie iere etree er er eee 60 48 56 
Transverse diameter of posterior face of centrum including faces for heads of ribs...... 93 83 92 
Vertical’ diameter’ of neural canals: 2) sas. ae eee ete ee eee 25 22 23 
Mransverseidiameter of meuralicanalit i. shes pee ie eae ree 25 22 23 
Antero-posterior diameter of prezygapophyses...........-.-----ssesesee sects eee eee 26 28 27 
‘Transverse: diameteriob prezyeapophyses sa. ee eee ae eee 16 15 17 
Distance) acrossiprezygapophysess +). -14.- 21 eee ee ce One ee eee 54 54 60 
Antero-posterior diameter of postzygapophyses.-..-+---5e.+.+..- 4-5 4s sees eee 32 27 
Dransyerserdiame ferrol pOSstzye a0) Iy.SCS eee teri nen meee pene ee 15 7 
Distance across postzygapophyses..45 0. sua ee eee enc ae 50 50 
% Higures in italics denote approximate measurements, 
