1870. | AXIAL SKELETON OF THE URODELA, 265 

Dorsal view of four trunk-vertebra of Stren (No. 5768 in Museum of College 
of Surgeons). 
e, Capitular process. ¢. Tubercular process. 7. Interzygapophysial ridge. 

Lateral view of four trunk-vertebrae of Siren (No. 5768 in Museum of College 
of Surgeons). 
ce. Capitular process. ¢. Tubercular process. 7. Interzygapophysial ridge. 
tebree of Siren (figs. 3 & 8), Amphiuma (fig. 4), Pleurodeles, Triton 
palmatus, and some other forms. Very often the neural ridges of 
the caudal vertebree are lofty in species which have the neural ridge 
of their trunk-vertebree quite inconspicuous. This is the case, e. 7., 
in Triton cristatus, Chioglossa, &c. Processes from the margins of 

Side view of 28rd, 24th, 25th, and 26th vertebre of Amphiuma (No. 5794 
in College of Surgeons’ Museum). 
H. Hyperapophysis. ¢. Capitular process. ¢. Tubercular process. 
the posterior median notch of the neural arches of the trunk-verte- 
bree often project backwards and more or less conspicuously upwards, 
preeminently so in Proteus (in spite of the low neural crest of that 
form), also in Amphiuma (figs. 5 & 17, H) (where the processes are 
very distinct though short) and Spelerpes rubra, and more or less so in 
Triton palmatus, Pleurodeles waltlii, &c. This condition is always 
still more marked in the caudal region, where in Spelerpes rubra 
