H. GOYIER SEELEY ON MAUISATTRTTS GARDNERI. 543 



of the base of the centrum external to the ribs is 2-£ inches. The bases 

 of the ribs are strong, elevated, and directed chiefly downward. The 

 sides of the centrum are smooth, concave from front to back, and 

 moderately convex from above downward, and extend vertically for 



1 inch above the ribs ; the neural arch is confluent with the cen- 

 trum, and unites with it by a large compressed squamose base, which 

 fits into an impressed concave area. 



The fourth specimen is 3| inches long ; and the whole centrum is 

 somewhat larger, with flatter articular faces and deeper excavations 

 on the base of the centrum. The fifth, a trifle longer, shows the neural 

 canal as a deep channel, concave from front to back, and at least an 

 inch wide. The articulation for the rib is nearer towards the 

 anterior margin of the centrum, where the process is thicker than 

 posteriorly ; as fractured it is 1-Z- inch long. The seventh centrum 

 is 4 inches deep and about | inch wider ; so that the articular face 

 has become more circular. This surface is much flatter, but now 

 has a shallow central concavity an inch in diameter. The centrum 

 is 4| inches long ; its basal excavations are more elongated, and the 

 upper part of the centrum is more compressed. The eighth centrum 

 is larger in the articular faces. The neurapophyses are remarkably 

 extended from front to back, and greatly compressed, each being 

 less than | inch thick. On the base, separated by the rounded 

 median ridge, are two large oval nutritive foramina about f inch 

 apart. The bases of the ribs grow stronger and are i inch in depth. 

 The tenth centrum is 4| inches long, with the articular face as deep 

 and 5g inches wide, though the width over the articulations for the 

 ribs is somewhat less. In the eleventh the base for the rib has 

 become more ovate and larger, and the base of the neural canal has 

 increased with the size of the vertebra, the neural arch being 



2 inches wide externally behind. 



The thirteenth vertebra has the neural arch well preserved (PI. 

 XXIII. fig. 2). The centrum is 4 inches in antero-posterior length. 

 Its anterior face is 5f inches wide and about 4§ inches deep. It has 

 a central depression 2 inches broad, margined by an elevated rounded 

 rim, between which and the circumference is a second concave area 

 in the form of a ring, but less deep. The posterior articulation is 6 

 inches broad and 4^- inches deep ; it has the transversely oval central 

 area shallow, but without the elevated rim. The base of the centrum 

 is 4| inches long ; it is convex from side to side, with an obtuse median 

 ridge. The distance between the articulations for the ribs is 

 5| inches. The articular surface for the rib is subcircular, l|inch 

 deep, and near]y 1 J inch from front to back ; this area is j inch from 

 the posterior margin and more than 1^ inch from the anterior 

 margin of the centrum. The lateral area above the articulation for 

 the rib is flattened, concave from side to side, and scarcely concave 

 in depth. And the neural arch rises steadily from the side of the 

 centrum without any break to a height of 10J inches, being im- 

 perfect superiorly. The neural arch is much compressed from side 

 to side. The posterior zygapophyses hang entirely behind the 

 posterior articular face of the centrum ; they are close together, being 



