200 THOMAS DWKiHT OX 



The spread of the lumbar transverse processes, counting these as ribs, increases steadily 

 to the 5tli, but the (htt'erence between the h)west four is slight, and in tlio 24tli they are 

 delicate. Tlio left costal element of the 2-')i[i vertebra projects dow uward from the trans- 

 verse process to join the sacrum, but does not touch the ilium; neither does the trans- 

 verse process. Tlie latter is normal on the right. The five sacral vertebrae are probably 

 normal, except tbat only two touch the ilium. The conjiKjata rem is at the od. There 

 is a deficiency on the left of the ■')\\\ that is probably the result of an injury in preparation. 

 The foiu" pieces of the coccyx are small. 



It seems that tliere is a pretty regular gain in tlic freedom of the 25th vertebra, 

 shown in the spines of this class. In two the sacralization was about eipial on both sides, 

 in one it was entirel}- on the right, in three it was entirely, and in one chiefly, on the left. 

 Were no other regions to be considered, the series of 2oth vertebrae in this class might 

 serve very well to illustr;ite Roseidjerg's theory. In other respects, however, this series 

 luis maii3' features that it is hard to group together. The 20th vertebra is by no means 

 always alike, now uioi-e thoracic and now more hnnliai-. The l-"!th pair of ribs varies 

 widel_y. In two cases (G-22 and 2) the 1st pair of ribs is under-developed. In the 

 former there is a concomitantly strong development of the l-!th pair which would implv a 

 moving downward of the thorax ; but in the latter there is only a slight development of 

 the loth pair. In one case the costal elements of the ntlas are wanting on both .sides, 

 and in one rudimentary on one side. In the former of these (again G-22) the costal 

 element of the 7th is wanting on one side. Spine X has an uncommon asvmmetrv of the 

 two sides. Altogether this class is a very confusing one. 



Class 111. 



This class comprises the spines in which there are more than 24 perfect praesacral 

 vertebrae. It is sul)divi(led into three groups. In A the extra praesacral is thoracic; in 

 B it is lumbar; in (J t\w f»/cr((/iK is the 27th, so that there are two extra praesacrals. In 

 the two cases of this anomaly one of the additional vertebi'ae is thoracic and the other 

 lumbar. In both the last hnnbar is sacrali/.ed on one side. The following spines are in 

 Class III. Group A: 54-5. A-4, 764, 504. A-18G, 578, 110. Group B: 403, Y, 381, 

 Gnmp C: 208, 2'.t7. 



