124 MERIST1C VARIATION. [part i. 



it. In this it is peculiar. Four specimens shewed the following 

 arrangements : — 



H. horridum No. 1. First caudal is the 36th vertebra (Troschel). 



ditto No. 2 37th (Baur). 



H. susjyectum No. 1 38th (Shufeldt). 



ditto No. 2 39th (Baur). 



Baur, G., J. of Moiyh. iv. 1891, p. 335. 



tF t~\ 



56. 



Batrachia. 1 



Rana temporaria. In the normal frog there are nine 

 separate vertebrae in addition to the nrostyle. A specimen is 

 described by Bourne having 10 free vertebrae (Fig. 11, III.). The 

 axis and third vertebra bore tubercles upon the transverse pro- 

 cesses, perhaps representing a partial bifurcation of the kind 

 described in No. 58. The ninth vertebra was abnormal in having 

 zygapophyses, and in that its centrum presented two concavities 



Figure 11. Vertebral columns of Frog (Rana temporaria), after Bourne. 



I. Specimen having transverse processes borne by the atlas, together with 

 other abnormalities described in text No. 58. 



II. Normal Vertebral Column. 



III. Specimen having ten free vertebras, described in text, No. 56. 



1 I regret that the paper bearing on this subject lately published by Adolphi, 

 Morph. Jalirb., 1892, xix. p. 313, appeared too late to permit me to incorporate 

 the valuable facts it contains. 



