8 Descriptions of Preparations. 



backwards from it towards the sacrum. Well-marked and distinct 

 anapophyses and metapophyses are developed on the anticlinal 

 vertebra, and are to be seen on the succeeding vertebrae nearly or 

 quite up to the sacrum. The direction of its spine relatively to those 

 of the other vertebrae in front of and behind it causes it to be the 

 point of greatest mobility in the trunk. Points of less striking 

 proportions, but more or less distinctive of, and universal in, the 

 order are presented in the skull by the presence of an interparietal 

 bone; by a vacuity in the skull walls for the blood to pass out 

 from the lateral sinus, either as here by a conjugate foramen 

 between the squamosal and the periotic, or by a foramen in the 

 squamosal itself, the so-called ^canalis temporalis/ by the develop- 

 ment of the post-auditory process of the squamosal into a lamina 

 of bone, which may reach as far back as the occipital, but serves 

 always to keep the tympano-periotic, with which it never anchy- 

 loses, in place ; and, finally, by the smallness of the angle formed by 

 a line drawn from the posterior edge of the supraoccipital on to the 

 basicranial line. The depth of the symphysis pubis, and the oblique 

 forward direction of the transverse processes in the lumbar region, 

 are points probably correlated functionally with the strength of the 

 hind limbs. The large size of the abdominal relatively to the 

 thoracic cavity may be connected with the multiparous character 

 of the order generally. The spine of the second dorsal vertebrae 

 has a small ossicle articulated to its apex, and pointing forward, 

 much as in the long-necked grazing mammals the ligamentum 

 nuchae is placed along the dorsal and cervical regions. The two first 

 cervical vertebrae are, as is usual in mammals, much the largest in 

 the series, and they contrast with the other cervical vertebrae, as 

 also with all the rest of the moveable vertebrae, in having, when 

 adult, the centre of the first fused with that of the second, and 

 in being connected with each other and the skull by cartilages 

 and synovial membranes without fibro-cartilaginous discs. The 

 first rib has its head articulated to the bodies, and its tubercle 

 to the transverse processes of both the last cervical and the first 

 dorsal vertebra. There are two lateral episternal bones between 

 the first of the six sternal bones, the so-called ' manubrium' and the 

 clavicle, one on each side, but there is no central episternum. 



In the carpus there are the same number of bones as in that of 

 man, for though the scaphoid and lunar are fused into one bone, the 



