PHYLOGENY OF THE PALZOGNATHA AND NEOGNATHA. 273 
lumbar neural spines but little axially extended, but considerably 
extended dorso-ventrally and not subequal in height ; synsacrum with 
post-sacrals not at all raised dorsad of acetabula, but rather depressed 
ventrad ; post-sacrals perfectly ossified; sacral plainly distinct from 
post-sacral vertebre; no lumbo-sacral vertebre; pre-caudal vertebre 
ten; pygostyle a laterally compressed plate . 
f’. Total number of vertebre forty-nine; cervical vertebre fourteen; pre- 
axial articular dorsal surface of atlas with only a minute dorsal notch ; 
no hyperapophysis to atlas; hypapophysis of axis not very large; 
neural spine of axis not very high; hyperapophyses of axis well deve- 
loped; neural spines of cervical vertebr almost obsolete, those of 
fourth to seventh vertebre abort; 
sixteenth vertebre bifurcate laterally; hypapophyses developed from 
last cervical to second dorsal vertebra; hypapophyses narrow and 
pre-axially produced ; a conspicuous fossa on each side of pre-axial part 
of neural spines from twelfth to the fifteenth imclusive ; cervical ribs 
short and not styliform; free cervical ribs nine ; synsacrum with post- 
sacral vertebr raised quite dorsad of acetabula, also very imperfectly 
ossified and much reduced; sacral plainly distinct from post-sacral 
vertebre ; post-sacrals nine ; free caudal vertebre five; pygostyle small 
and cylindrical 
The vertebral formula is :— 
MC IELS DBO 0000 OAS Cy. 
(CUSTEATS * Sasecanne- Cy 
Struthio ...-.....-.- Cy. 
sh SRORC ED OTAnCGaC Cy. 
Apterya ...... Sonocn tne 
(A. a. mantelli.) 
Bile: 
14: 
15: 
Cy. 
Cy. 
Cy 
Cy. 
Cy. 
Th. 
Th. 
. Th. 
Th. 
Th. 
Struthio. 
neural spmes of thirteenth to 
cu peaatoy ee} Lhd Nuala Rhea. 
Synsac. ees 
— 
Th. 34+1+2: Lb.6: Lb.sc.2: Se. 2: Cd. 949=55. 
——4 —— 
6 18 
Synsae, 
Tas 
Th.54+1+8: Lb.5: Lb.sc.2: 8Se.2: Cd. 94+9=55, 
es MeY—4 
9 18 
Synsac. 
= 
Th.54+2: Lb. 8: Se.2: Cd. 8+10 =5d. 
———— ——— 
a 18 
Synsac. 
Th.3+2+1: Lb.3: Lb.se.4: Se. 2: Cd. 948=49. 
es ——s 
6 17 
Synsac. 
an a 
Th.44+3+4+1: Lb.4: Lb.se.4; Se. 2: Cd. 348=45, 
—— ee 
8 11 
