472 



T. 13. 



L.l. 



covered by a thin layer of cartilage; but in the other bones their 

 development is complete. 



All the caudal epiphyses left the centra during preparation ; the 

 first three presenting the projections to which attention has been called 

 in connection with the last three thoracic vertebrae (Fig. 1 *). It 

 should be remarked that, on the disappearance of this character, there 



is no longer the presence ot a similar 

 feature of the epiphysis in the middle 

 line, i. e. at the ventral end of Al- 

 brecht's Crista praeumbili- 

 calls. 



In the younger lion all the ce- 

 phalic epiphyses are also loose; but 

 in the older animal that of the last 

 vertebra has become joined laterally 

 by bone to the rest of the vertebra. 

 Even in lion No. 1 there is apparently 

 the commencement on fixation of the 

 right side. ' 



Sacrum. The three bones com- 

 posing the sacrum have joined so 

 completely by their transverse pro- 

 cesses that there is no line showing 

 where union has taken place. In 

 lion No. 2 the coalescence of the 

 contiguous arches has not advanced 

 very far. In lion No. 1 this may be 

 said also of the first and second 

 arches; but the fusion of the second and third is complete. The 

 cephalic epiphysis of the first vertebra is firmly united laterally; the 

 union here being so close that no trace of epiphysial line remains, 

 though it is very clear both dorsally and ventrally. 



The epiphyses between the first and second and between the 



L.2 



L.3 



Fig. 1. Ventral aspect of the last 

 thoracic and tlie first, second and thii'd 

 lumbar vertebra?. ce.e. cephalic epi- 

 physis, ca.e. caudal epiphysis. * thicken- 

 ing of the caudal epiphysis at the end 

 of Albrecht's Crista centro-neui'alis. 



groove. Naturally, the caudal articular processes of the first thoracic 

 vertebra are the counter-parts of the cephalic processes of the second. 

 This abnormality reminds one of the condition of the cephalic 

 articular processes of some of the thoracic vertebrae ofMyrmecophaga 

 jubata, as described by Rosenberg (Festschr. z. 70. Geburtstag v. C. 

 Oegenbaur, Bd. 2, Leipzig 1896), and of the Xenarthra in general. 

 It is possible, however, that it is a spontaneous variation having no 

 morphological significance. 



