52 THORACIC AND LUMBAR VERTEBRAE. [CHAP. 



throughout the series, rather slender, and sloping backwards 

 in the thoracic region ; broader (in the antero-posterior 

 direction) and more upright in the lumbar region, and pre- 

 senting but scarcely any indication of that convergence 

 towards a point in the posterior thoracic region so frequently 

 seen in other Mammals. They are generally simple and 

 slightly dilated at their ends ; but in the lumbar region, the 

 posterior edge is often more or less bifid. 



The zygapophyses are well developed throughout. In 

 the thoracic region they are oval, fiat facets, looking pretty 

 nearly directly upwards (the anterior) and downwards (the 

 posterior) : the anterior, developed on the top of the pedicle 

 and projecting forwards, being supported by the " oblique 

 process ; " the posterior is placed on the under-surface of the 

 hinder part of the lamina. In the lumbar region, their form 

 and position change, the anterior having their outer edges 

 turned upwards, and supported by a short rounded meta- 

 pophysis (inammillary process). The posterior ones have 

 undergone a corresponding change, so that their faces, instead 

 of looking downwards, are directed obliquely outwards ; they 

 are also much curved. 



The transverse processes project throughout the series 

 from the arch, near the junction of the pedicle with the 

 lamina. In the greater part of the thoracic region they are 

 tolerably long, project somewhat upwards and slightly for- 

 wards, and are dilated and tuberous at the extremities, on 

 the under-surface of which (except in the two last) they show 

 a smooth concave facet for the attachment of the tubercle of 

 the rib. In the posterior part of the thoracic region they 

 are shorter, and begin to resolve themselves into three dis- 

 tinct processes, generally conspicuous in the first lumbar. 

 One of these projects outwards, and, elongating in the second 

 and third lumbar, it forms the principal transverse process. 



