48 PROCEEDINGS OF THE NATIONAL MUSEUM vol. GO 



mm. in front of the posterior margin of the neural arch is a small 

 foramen which leads from the neural canal and opens into a broad 

 groove which extends downward across the lateral face of the 

 centrum to the superior orifice of the lateral vertebrarterial canal 

 at the base of the vestigial transverse process. The metapophyses 

 project forward beyond the anterior epiphysis. The minimum an- 

 teroposterior diameter of the neural spine (13.7 mm.) is slightly 

 more than one-half of the minimum diameter of the neural arch 

 (21 mm.). The height of the neural canal posteriorly is 3.5 mm. 



Thirteenth caudal. — It (pi. 13, fig. 3) is characterized by a very 

 small neural spine, which is longer than high, small but distinct 

 metapophyses, and a pair of thick platelike descending processes 

 which extend the length of the inferior face of the centrum, with 

 facets for chevrons at both ends. Each of these descending processes 

 is pierced mesially by a small foramen which opens on the lateral 

 face of the centrum into a short deep groove, that in turn leads to 

 the lateral vertebrarterial canal. Above the dorsal orifice of this 

 vertebrarterial canal is a short groove which, however, does not 

 extend upward as far as the posterior margin of the neural arch. 

 The distance between the dorsal and ventral orifices of the lateral 

 vertebrarterial canal is 9 mm. The neural canal is very small. The 

 centruln is pierced dorsoventrally near the middle by a pair of 

 minute canals. The anterior epiphysis is missing. 



Fourteenth caudal. — The posterior epiphysis (pi. 13, fig. 4) and the 

 neural spine are missing, but otherwise the vertebra is complete. 

 The centrum is as deep as long. Thick platelike descending proc- 

 esses bearing facets at the anterior and the posterior ends for chev- 

 rons extend the full length of the inferior surface of the centrum. 

 They are separated mesially by the usual longitudinal excavation and 

 are pierced behind the middle by a small foramen. The distance 

 between the dorsal and ventral orifices of the vertebrarterial canal is 

 12.3 mm. This caudal apparently had a small neural spine, but it 

 has been destroyed. The small neural canal is open, but the meta- 

 pophyses are vestigial. 



Terminal caudal. — This caudal measures 16.7 mm. in width, 6+mm. 

 in thickness, and 9.5 mm. in depth. One face of the centruta was 

 destroyed by the pick of the collector. The centrum is pierced 

 dorsoventrally by a pair of large canals, the dorsal orifices of which 

 are at least 5.8 mm. apart ; the dorsal and ventral surfaces are con- 

 vex from side to side. The side which appears to be the anterior face 

 is convex. A pair of blunt processes are developed on each side at 

 the dorsal and ventral angles by the mesial side to side constriction of 

 the centrum, and in direction they are oblique to the transverse axis 

 of the centrum. 



