34 NATURAL SCIENCE. Jan., 



example of the entire skeleton, is very different from that of all the 

 allied genera, its chief peculiarity being the curiously-incurved form 

 of the nasal bones, and the consequent involution of the nostrils. The 

 head-shield was long, curved, and smooth, with the largest plates 

 posteriorly. Three specimens of the carapace of this genus are 

 mounted in the gallery ; one of these being associated with the head- 

 shield and tail-sheath. The species of this genus from the Monte 

 Hermoso beds appear to have been fully as large as their Pampean 

 representative. 



Although I have at present had no opportunity of going into the 

 question of the number of species of Glyptodonts represented in 

 the Pampean formation, I have not the least hesitation in saying that 

 a large proportion of those named on the evidence of specimens of 

 the terminal tail-tube or fragments of the carapace will be found 

 invalid. The same is doubtless true with regard to several of the 

 so-called genera founded on remains from the older formations of 

 southern iVrgentina. Although it is not my intention to enter here 

 into the consideration of the Glyptodonts of the Santa Cruz beds of 

 Patagonia, I may mention that one of the greatest treasures of 

 the Museum is the entire skeleton and greater portion of the carapace 

 of the dwarf Propalahoplophonis, to which incidental allusion has 

 already been made. As shown both by the conformation of the skull 

 and tail-sheath, these dwarf Glyptodonts were much more nearly 

 allied to Glyptodon than to either of the other Pampean genera, all the 

 latter being probably, therefore, more specialised types of later origin. 



Although in the Pampean formation the short-snouted Glypto- 

 donts appear to have been the dominant types of the Loricate Eden- 

 tates, it must not be inferred that the long-snouted Armadillos were 

 absent. While some of these forms found in the deposits in question 

 were more or less closely allied to, or even identical with, their living 

 cousins, others, like Eutatus, were of much larger size, and differed by 

 having the whole carapace formed of movable bands. Still larger 

 was a recently-discovered armadillo, for which the name Dasypothevmm 

 has been proposed ; the skull of this giant measuring upwards of 

 xo^ inches in length. Remains of the existing genus Dasypus are not 

 uncommon in the Pampean, and the Museum possesses some beautiful 

 •examples from Monte Hermoso, one of which shows both the skull 

 and carapace. I may mention here that a species oiDasypus allied to the 

 existing D. minimus (which it has been recently proposed to separate 

 generically as Zaedius) occur in the Santa Cruz beds ; a fact which 

 has an important bearing on the geological age of the latter. 



Before leaving the mammals of the Pampean beds, I must not 

 omit to mention the fine series of equine remains contained in the 

 Museum ; although in regard to one or two species, the La Plata 

 collection is inferior to that of the Buenos Aires Museum. x\mong 

 the more notable specimens, I may refer to a skeleton of an Equus, 

 which has been assigned by Sehor Arneghino to a so-called species 



