32 . NATURAL SCIENCE. Jan.. 



May we accordingly venture to suggest to the authorities of 

 the Royal College of Surgeons that the specimen in their 

 Museum thus anomalously restored might now be advantageously 

 dismounted, since in its present state it merely tends to perpetuate 

 an accidental error ? Marvellous as are all the Glyptodonts, the 

 most astounding monster in the whole series is undoubtedly the 

 one denominated Dcedicurus. The total length of this monstrous 

 skeleton, as it is now mounted, is upwards of ii feet 8 inches 

 measured in a straight line, while the carapace measures lo feet 

 4 inches across the highest part of the back, and the length of the 

 massive club-like terminal tube of the caudal sheath is upwards of 

 3 feet II inches. Since, so far as I am aware, there is nothing 

 approaching to a complete skeleton of this strange creature in any 

 European Museum, my readers will probably pardon me if I enter 

 into a few details of its structure. It will be observed, in the first 

 place, that the carapace is remarkable for its curiously hump-backed 

 contour, in which respect it differs very markedly from the regularly 

 egg-shaped shell of Glypiodon ; while it is further distinguished by 

 the absence of the bold conical bosses with which the periphery of the 

 latter is ornamented. Then, again, there is a marked difference in 

 regard to the structure of the individual plates of which the carapace 

 is composed ; for whereas in Glyptodoii these are polygonal, with a 

 rosette-shaped pattern formed by the impressions of the edges of the 

 overlying horny shields, in the present form they are oblong plates of 

 bone, with a smooth external surface, devoid of the impressions of 

 horny shields, but severally perforated by from one to five large 

 circular holes, through which quill-like bristles were doubtless pro- 

 truded during life. The tail was protected for the first third of its 

 length by eleven enormous bony hoops, each formed by a single ring 

 of plates similar to those of the carapace, but two of which not 

 unfrequently coalesce, the circumference of these hoops rapidly ' 

 decreasing from the base of the tail towards its extremity. The 

 terminal two-thirds of the tail are formed by the well-known club-like 

 tube so frequently exhibited in European Museums. At its flattened 

 and expanded extremity, this tremendous club bears a number of 

 roughened, depressed, disc-like facets of an oval contour, which 

 during life must evidently have given support to huge horny spines, 

 probably not unlike the horns of a rhinoceros. The whole animal 

 must accordingly have bristled with horns and quills, looking not 

 unlike some giant porcupine. In the somewhat smaller species from 

 Monte Hermoso, theie are more of the disc-like surfaces on the tube 

 of the tail, which also differs from that of the Pampean species by 

 being less expanded at the end and by the presence of a number of 

 flat oval plates on the upper surface. The two imperfect specimens 

 of the carapace of the species of this genus from Monte Hermoso in 

 the collection of the Museum are remarkable for having a crater-like 

 elevation with a central perforation immediately over the point of 



