98 



PLEISTOCENE MAMMALIA. 



With the eighth vertebra the neural canal ceases, and is represented on the rest of the 

 vertebrse by a shallow groove on the dorsal surface of the centrum, the sides of the groove 

 passing into diverging metapopliysial and united postzygapophysial tubercles, which do 

 not in any case project over the epiphyses. The centra of these vertebrse are more 

 or less cylindrical, the strong di-an-apophysial ridges on the sides, the neurapo- 

 physial on the dorsal and the muscular ridges on the ventral surface, making them 

 more or less angular at various points. The ninth is generally the stoutest (PI. XVI, 

 fig. 5), and the tenth (fig, 6) and sometimes the eleventh (figs. 7, T, 7") is the 

 longest of these vertebrse, which diminish in size rather rapidly to the end of the tail. The 

 last vertebra appears sometimes to be cartilaginous in the recent Eeles. The epiphyses are 

 anteriorly nearly circular, and distally more or less quadrangular and highly convex. The 

 metapophyses are flat plates subsiding into rounded tubercles distally, diverging and 

 pointing slightly forwards on the ninth, but becoming more upright distally. The diapo- 

 physes and anapophyses have been described above, the hypapophysial tubercles are dis- 

 tinct throughout the series. The position of the vertebrae can be only fixed by comparison 

 with a known series, and the variations of proportion of the parts are such that this comparison 

 cannot produce absolute certainty, and the uncertainty is made greater by the great varia- 

 tion in size, which may be estimated from our figures of the tenth and eleventh vertebrse, the 

 tenth being taken from the series above mentioned, which is slightly larger than that of the 

 average lion, and the eleventh from another series of much more gigantic proportions. Prom 

 the smaller series we have figured the ninth, tenth, twelfth, thirteenth, and fourteenth (PI. 

 XVI, figs. 5 — 10). We have also a series of large size from the ninth to the thirteenth, one 

 other ninth and an eleventh besides a fifteenth, a sixteenth, a seventeenth, an eighteenth, and 

 a small vertebra near the extremity of the tail. These determinations of place are, of course, 

 subject to the uncertainty above expressed. The general description applies equally to all. 

 The only difference he can see between them and those of the Lion is, that the metapophyses 

 appear to be somewhat less divergent, but this appears to be variable, not only in Lion, but 

 also in Felis spelaa. The proportions also are somewhat longer than in the Lion in most 

 cases, but some vertebrse of the position, of which we have no doubt whatever, appear to 

 be somewhat shorter. 



Measurements of Atlas. (In Inches.) 



1. Minimum height of neural arch 



2. Width of neural arch at tubercles for transverse ligament 



3. Zygapophysial length 



4. Maximum width of prezygapopliysis (e.xternal) 



5. Width of the same at the edge of the glenoid articulation 



6. Width of the postzygapophyses 



7. Minimum proximo-distalleugth of neurapophyses 



Felis spelaa. 

 Sandford Hill 



1.27 

 1.15 

 .3.32 

 3.26 

 2.54 

 3.40 

 1.59 



Felis leo. 



1.00 

 0.98 

 2.75 

 2.58 

 2.20 

 2.70 

 1.30 



