NOTES ON THE CAUTDJE OF THE WHITE RIVER OLIGOCENE. 339 



behind the arch, and between each transverse pair is a deep notch which greatly reduces 

 the antero-posterior length of the bony arch in the median line. When the vertebrae are 

 placed in position, the openings between the successive arches, on the dorsal side, are 

 very large and are longer antero-posteriorly than broad transversely. In these peculiari- 

 ties of the cervical vertebras of Daplumus we find no approximation to the structure of 

 the cats or the viverrines. 



The neural spines are also quite differently developed from those of the recent dogs. 

 The third cervical has no spine, merely a very faintly marked keel, the overhanging 

 spine of the axis leaving no room for the development of one on the third vertebra. 

 The fourth cervical has a very low spine, and on each successive vertebra the spine 

 becomes higher and more pointed ; that of the seventh is very high and slender, very 

 much more prominent than in Canis, being almost as high, though not nearly so stout, 

 as the spine of the first thoracic vertebra in the modern genus. The length of the spines 

 in the neck constitutes another similarity to the structure of the felines. 



Thoracic Vertebrce. — The number of trunk vertebras characteristic of Daphcenus 

 cannot as yet be definitely determined for any of the species, for no specimen has been 

 found with complete backbone. In one specimen of D. vetus are preserved twelve 

 thoracic and five lumbar vertebra? and the type of D. felinus contains six lumbars. It is 

 altogether probable that the extinct genus agreed with the existing dogs in having 

 thirteen thoracics and seven lumbars. The first thoracic has a broad, very much 

 depressed centrum, with anterior face convex and posterior face deeply concave. The 

 prezygapophyses project forward very strongly and, as in the cervicals, the notch between 

 them is very deeply incised, invading the base of the spine, a very different arrangement 

 from that seen in Canis; these processes are relatively larger and more concave in 

 D. vetus than in D. hartshornianus. The postzygapophyses are much smaller, but 

 j^roject prominently from the hinder end of the neural arch, extending both laterally 

 and posteriorly ; the articular faces are somewhat convex transversely and have an 

 oblique position, presenting outward rather more than downward. The neural spine is 

 high and compressed, shaped very much as in Canis, but somewhat more slender. The 

 transverse processes are very long, prominent and heavy, especially in the large species, 

 D. felinvs ; at the distal end of the process is a large and deeply concave facet for the 

 tubercle of the first rib. 



The second thoracic very much resembles the first, but has a smaller, narrower, 

 lighter, and much less depressed centrum ; the prezygapophyses are smaller, less concave 

 and less widely separated, while the postzygapophyses are larger and present downward, 

 instead of obliquely outward, as they do on the first. The transverse processes are much 

 smaller in every dimension than those of the first thoracic, and spring from the neural 



