EDENTATA OF THE SANTA CRUZ BEDS. 149 



Very little is known of the skeleton, but the parts which have been 

 found differ little, save in size, from those of the other contemporary 

 glyptodonts. In the collection of the American Museum is a nearly 

 complete "dorsal tube," which from its size is probably referable to this 

 genus. Like that of Propalceohoplophomts, this tube is composed of seven 

 vertebrae, doubtless the last six thoracics and the first lumbar, and it dis- 

 plays a number of interesting differences from the last-named genus. As 

 a whole, the tube has a stronger curvature and the bony ridge which con- 

 nects the successive transverse processes is considerably heavier ; the first 

 vertebra of the mass (? sixth thoracic) is more completely fused with the 

 succeeding one, and is somewhat shorter ; at the anterior end the neural 

 canal is small and almost circular, but changes its shape posteriorly, be- 

 coming larger and of a vertically oval cross-section. 



Three species of this genus may be distinguished, E. petestatus Ame- 

 ghino, E. complicatus Brown, and E. crassus, sp. nov. 



EUCINEPELTUS PETESTATUS Ameghino. 



(Plate XXI, Fig. 4; XXIV, Figs. 10, II.) 



Eucinepeltits petestatus Amegh.; Rev. Argent, de Hist Nat, T. I, 1891, 



p. 326. 

 Propalczohoplophoriis patagonicus Mercerat ; Rev. del Mus. de La Plata, 



T. II, 1891, p. 40. 

 Propalceohoplophorus australis Lydekker, in part; Anales del Mus. de La 



Plata, T. Ill, 1894, p. 48. 



Ameghino has described the cephalic shield (Plate XXI, fig. 4) of this 

 species as consisting of nine plates, two in the anterior row, three in the 

 middle, and four in the hinder row. It is, however, almost certain that 

 the two very large posterior median plates are themselves compound and 

 that the actual number is eleven, arranged in four transverse rows, which, 

 beginning anteriorly, have the following number of plates : two, three, four, 

 two. The sutures are raised into ridges of only moderate height and all 

 the plates have the median pit, except the anterior pair, in which the pit 

 is replaced by a low elevation. As a whole, the shield is of irregularly 

 circular shape, narrowing forward, and there is no marked constriction of 

 the borders between the first and second rows of plates. 



The carapace is known only in connection with this species and the 

 account of it, already given, need not be repeated here. 



