THOMAS DWKiHT ON 



bars, the first with a free costal element, and 5 sacral vertebrae, counting as such the 

 asymmetrical 2ijth, while on the left it looks more like 13 thoracic, 5 lumbar and 4 sacral, 

 with 4 coccygeals. The fact, however, that even on the riglit the 25th is not the fulcralis, , 

 shows that the notation of the left should be adopted for both sides. 



G-22. Cat. !)o79-12. 



Female, black, age prol)ably from 20 to 30. The figure was remarkal)lv good. C. 7, 

 T. 13, L. 5, S. 5, C. 4. 



In this spine the 25th vertebra is neai'ly free; but on the left its lateral mass, whicli 

 shows distinctly a costal and a transverse element, has the latter close to the ilium, to which 

 it is bound by ligament, but taking no pai-t in the formation of the auricular surface. The 

 right transverse process is very nearly normal and is distinctly separated from the ilium. 

 There are 13 pairs of ril)s. The first are not typical first ones, but narrower and somewhat 

 like second ribs, though showing the scalene tubercle. The 13th pair are typical last ribs. 

 The length along the anterior curve is 8.3 cm. for the right, and 3 mm. less for the left. 

 The costal elements of the atlas on both sides are either undeveloped or lost. The former 

 is more likely, for there is a small point at its usual jjlace of origin and another jutting 

 inward from the ti'ansverse process, so that the foramen is indicated, though open in front. 

 (According to Macalister ('93) tliis occurs on both sides in .2%, and one side in 1.6%). 

 The costal element of the 7th cervical vertebra is wanting on the right. There is no sign of 

 a facet. The change in the articular processes occurs below the 20th vertebra, but its supe- 

 rior left process is somewhat transitional. The spinous process of this vertebra is distinctly 

 lumbar. The spread of tlie lumljar transverse processes increases to the 3d. The next 

 (24th) is a penultimate. It is doubtful if the 3d sacral touches the ilium. It has the 

 cnnjugata vera. 



Probably the most significant feature of tliis spine is the presence of 13 pairs of ribs, 

 of which the lowest are typical last ones and the first not t_ypical first ones. This would 

 seem to be the first step of a moving of the thorax downward. It is to be remembered, 

 however, that the riglit costal element of the 7th \ertebra is wanting. Were there any 

 signs of its having had a head and tubercle, this spine might possibly be correctly described 

 as an archaic one. In their absence it may be that tlie freedom of this costal element, like 

 that of those of the atlas, is .simply accidental. The fact that the 24th has the characters 

 of a penultimate lumljar in this class, is worth noting. It shall be returned to. 



