GIANT GROUND SLOTHS — GAZIN • 345 



Our second season at El Hatillo was made particularly difficult by 

 the continuous battle against water seeping from the spring. Evi- 

 dently the dry season, which lasts from January to about April or 

 May, was this year preceded by more rainfall than the year before. 

 The situation greatly jeopardized our use of plaster of paris, but 

 by diligent bailing it was possible to keep the partially prepared 

 blocks of bone and matrix free of excess water sufficiently long for the 

 plaster of paris and burlap bandages to set (pi. 7, fig. 1). The col- 

 lection which included over 100 plaster-encased blocks, filled 13 large 

 boxes and was found to have an aggregate weight of about 3y 2 tons. 

 Again with the help of the U. S. Air Force, our collection (pi. 8, fig. 1) 

 was transported to the pier at Balboa. 



The success of our second expedition may be measured by the fact 

 that the additional materials obtained made it possible to select two 

 composite skeletons, based largely on the remains of single individuals, 

 representing mature animals rather near the upper (pi. 2) and lower 

 limits of size. There still remained a rather impressive surplus of 

 skeletal material which has been restored and returned to Panama to 

 join the Ocu collection in the museum at Panama City. 



TAXONOMIC HISTORY 



There would seem to be little or no doubt but that the correct name 

 for the giant Panamanian sloth is Eremotherium rusconii. The tax- 

 onomic history of this form is rather involved and makes an interest- 

 ing story in itself. The species was first described by the Swiss 

 paleontologist Schaub in 1935 from the province of Lara in Venezuela. 

 He referred it to Cuvier's (1796) genus Megatherium, so well known 

 in the Pleistocene of Argentina, but questioned the possibility of its 

 representing Paramegatherium as a subgenus. Without reference to 

 Schaub's work on the Venezuelan material, Spillmann in 1948 de- 

 scribed a skull and other material from Pleistocene deposits on the 

 peninsula of Santa Elena in Ecuador as the new genus and species 

 Eremotherium carolinense. Shortly afterward (1949), but evidently 

 without knowledge of Spillmann's publication, 1 Hoffstetter, working 

 in Ecuador, described additional material from the Santa Elena penin- 

 sula which he referred to Schaub's species M. rusconii, but gave it the 

 new generic name Schaubia, At the same time he described somewhat 

 smaller material as the new species Schaubia elenense. Discovering 

 later that the term Schaubia was preoccupied for a genus in the cat 

 family, he substituted (1950) the name Schaubitherium. Following 



1 Spillmann's paper, published in Vienna, though bearing the date 1948 on the 

 cover is described in a preface as ready for printing in 1945 but held up owing to 

 war conditions. However, it was not received in the library of the U. S. Geologi- 

 cal Survey until 1951 ; hence some question might arise as to the actual date of 

 publication. 



