ART. 26 REMAINS OF FOSSIL PORPOISES KELLOGG 25 



Measurements of fifth cervical vertebra 



mm. 

 Greatest depth (vertically) of vertebra (tip of neural spine to inferior 



face of centrmn) 73.6 



Greatest breadth of neural canal posteriorly 36. 8 



Height of anterior face of centrum 42. 4 



Breadth of anterior face of centrum 50. 2 



Height of posterior face of centrum 43. 2 



Breadth of posterior face of centrum 4S. 7 



Length of centrum 25. 6 



Distance across vertebra between tips of the diapophyses 67.2 



Distance across vertebra between tips of the transverse processes 



(parapophyses) 103. 2+ 



Distance across vertebra between tips of prezygapophyses 47. 6 



Distance across vertebra between outside margins of the postzygapo- 



physial facets 54. 3 



Distance between tip of left postzygapophysis and tip of left prezy- 



gapophysis 37. 1 



Minimum length of neurapophysis 11. l 



Anteroposterior length of neural spine in a horizontal line imme- 

 diately above the zygapophyses 10 



Vertical height of neural spine (distance between superior margin of 



neural canal and tip of spine) 11.5 



Maximum thickness of posterior epiphysis 5 



DORSAL VERTEBRAE 



Isolated vertebrae of fossil cetaceans are usually difficult to al- 

 locate when the full complement of the skeleton is unknown. 

 Abel ^^ has indicated the vertebral formula for Eurhinodelphis 

 and has published a restoration of the entire skeleton. It is not 

 known whether his observations were based on an associated skele- 

 ton, or whether a composite skeleton was constructed out of mis- 

 cellaneous vertebrae from deposits in the vicinity of Antwerp. 

 This formula in conjunction with the ribs found with the skull 

 have been used in allocating these vertebrae. 



From a study of recent types it might be argued that these seven 

 dorsals are sufficiently characteristic for definite allocation. This 

 is true so far as certain vertebrae are unquestionably anterior 

 and others posterior. The prezygapophysial facets on the anterior 

 dorsal of this porpoise are separated by a greater interval than any 

 of the succeeding ones. Hence the postzygapophysial articular 

 facets on each of the following dorsals tend to approximate one 

 another to a greater degree in accordance with their position in the 

 column. The centra of the dorsal and lumbar vertebrae increase 



'»Abel, O., Cetaceenstudien. I. Mftteilung: Das Skelett von Eurhinodelphls Coche- 

 teuxi aus dem Obermiozan von Antwerpen. Sitz.-ber. kais. Akad. Wiss., Wien, Mathem.- 

 naturw. Kl., vol. 118, Abt. 1, pp. 241-253, mit 1 pi., 1909. 



