264 MEMOIRS OF THE CARNEGIE MUSEUM. 
Antero-posterior diameter of anterior articulating surface of centrum.....................-...:- 50 
Transverse diameter of anterior articulating surface of centrum............................---- 45 
Transverse diameter of posterior face of centrum. . . : DE Re ONCROLUMC ce peinky rsa Le Seog oheue a Ges Aus ilo 65 
Supero-inferior diameter of posterion face of centrum] eee eee eee ee eee 70 
Vertical height of posterior end of centrum measured perpendicularly.....................-..-- 50 
Greatest height of keel of centrum below transverse processeS.............0-see cess cere ceeeeee 35 
Distance to neural canal from bottom of keel of centrum at middle.........................-..-- 45 
Mransyersediametenotneunalispinednitrontheean eee eernen hone een one nee rrre 1 
Transverse diameter of neural spine above origin of postzygapophyses.......,.........+.--+05- 40 
AMteLO=p OStELIOT) Ci aM Ebersole PM | yb OL Cae geste een wes eee teense 80 
Antero-posterior diameter of spine at upper extremity..............2.- cece ee cc eeet eee eeeeees 43 
Height of spine from origin« 22 55,8. svc..¢ feces oe © piktciee CR neue tem: cet oe eee ee Ee eee 45 
Antero-posterior diameter of outer margin of transverse processes................000e eee eeeeee 75 
Transverse diameter ohwertebrantenalicanalaes aes eee here eerie reer eter en ene roere error 8 
Supero-interion diameteriof vertebrartertalicanals =e eae eee eee eee eee eee 15 
The Fourth Cervical Vertebra. 
The fourth cervical vertebra of specimen No. 1604 is excellently preserved. 
It closely resembles in its general structure the third cervical, but is broader trans- 
versely. The anterior and posterior tubercles of the transverse processes are 
heavier and tend to assume a more vertical position in relation to each other than 
V7 
S 
S 
S 
= 
Fic. 33. Lateral view of fourth cervical of M. ela- Fic. 34. Ventral view of fourth cervical of WM. ela- 
tus (No. 1604). 3. tus (No. 1604). X#4 
is the case in the third cervical. The horizontal marginal sinus back of the trans- 
verse process is not as deep as in the preceding vertebra, and the neural spine is 
not as heavy on its upper margin. The protuberances on the lower margin of 
the posterior articulating face of the centrum marking the lateral boundaries of 
the widening keel are much enlarged and prominent. 
