AltT. 19 



A MIOCENE PORPOISE FROM MARYLAND — KELLOGG 



37 



than those of the third cervical. The superior transverse processes 

 are thin, projecting obliquely downward and outward, and enclosing 

 a small vertebrarterial canal. 



Fifth cervical. — As regards thiclaiess, the centra of the fourth 

 and fifth cervicals are about equal. The neural arches are slightly 

 thicker than those of the fourth and are inclined very slightly back- 

 ward, but the zygapophyses are similar to the preceding. The infe- 

 rior transverse processes (pi. 14, no. 22) are considerably shorter than 

 those of the fourth and are also thicker. Most of the superior trans- 

 verse process on the right side is missing, but enough remains to show 

 that the vertebrarterial canal is much larger than any of the pre- 

 ceding. 



Sixth cervical. — The centrum is slightl}^ thicker than the preced- 

 ing. Probably the most characteristic feature of this cervical (pi. 

 14, no. 23) is the direction of the inferior transverse processes. These 

 processes are similar in proportions to those of Delpkinodon divi- 

 dum^ but are directed almost straight downward, while in D. divi- 

 dum they are directed as much outward as downward. The distance 

 between the extremities of the inferior transverse processes is 35.5 

 mm. (outside measurement). The neurapophyses are essentially 

 vertical. The superior transverse processes are bladelike plates 

 Avhich are inclined forward. The neural spine is very short. 



Seventh cervical. — In contrast to the preceding cervical, the thin 

 blade-like superior transverse processes are directed forward and the 

 inferior ones are vestigial. The centrum (pi. 14, no. 24) also is 

 slightly thicker than the sixth, and the neurapophyses curve upward 

 and forward. There is an articular facet for the capitulum of the 

 first rib on tlie posterosuperior angle of the centrum. The greatest 

 anteroposterior diameter (14.1 mm.) of the combined zygapophyses 

 is considerably greater than that of the preceding A^ertebra (10 

 mm.). Both epiphj'^ses are missing. 



Measurements of the cervical vertebrae {in jniUimeters) 



' Both epiphyses missing. 



