NO. 1496. A NEW GREAT AXT-EATER— LYON. 571 



the middle of the root of the zygomatic process, in M. centralis the 

 same point is situated much more posteriorly. 



The differences in size between the two specimens figured is due to 

 age or to individual variation, as some Central American skulls are as 

 large as the South American skull figured, and some South American 

 skulls are as small as the Costa Rican skull figured. The interorbital 

 constriction seen in the Brazilian skull is probablv individual. 



Considerable variation is seen in various parts of the skulls of the 

 Great Ant-eaters, especially in the region of the lachrymal bone, the 

 antero-posterior diameter of which is relatively short in all the Central 

 American skulls, while in some of the South American skulls it is 

 much elongated, and in others it is short. It is possible that when 

 large series of specimens are obtained from definite localities, other 

 forms of the Great Ant-eater may be recognized. 



SKULLS EXAMINED. 



Myrmecojyhaga centralis 



Cat. No. 15963. U.S.N.M. Pacuare, Costa Rica, Type. 



Cat. No. UIOT. U.S.N.M. Talamanca, Costa Rica. 



Cat. No. 141.55. U.S.N.M. Talamanca, Costa Rica. 



Cat. No. 10095. Mus. Comp. Zool. (Bangs coll.), Divala, Panama. 



Myrmecophaga tridactyla."' 



Cat. No. 13001. U.S.N.M. Surinam. 



Cat. No. 143131. U.S.N.M. Surinam, 



Cat. No. 49597. U.S.N.M. San Sebastian, Marajo, Brazil. 



Cat.' No. 22986. U.S.N.M. (mounted skeleton). Locality unknown. 



Cat. No. 20753. U.S.N.M. (mounted skeleton). Localit}^ unknown. 



Cat. No. 8414. Mus. Comp. Zool. (Bangs coll.). Dibulla, Colombia. 



Cat. No. 194. Amer. Mus. Nat. Hist. Brazil. 



Cat. No. 16137. Amer. Mus. Nat. Hist. Ciudad Bolivar, Venezuela. 



Cat. No. 16924. Amer. Mus. Nat. Hist. Maripa. Venezuela. 



Cat. No. 4634. Acad. Nat. Sci. Phila. Brazil. 



. Cat. No. 4639. Acad. Nat. Sci, Phila. Brazil. 



EXPLANATION OF PLATE XIY. 



All figures about ^^^ natural size. 

 Figs. 1 and 3. Myrmecophaga centralis, No. 15963, Type from Paouare, Costa Eica. 

 Figs. 2 and 4. Mi/rmecophaga trklactyla, No. 49597, from San Sebastian, Marajo, Brazil. 



In both skulls the fronto-nasal sutures, and those about the squamosal and ali- 

 sphenoid have been intensified by the use of pigment before the photographs were 

 taken. 



«The skull represented in Flower's Osteology of the Mammalia, 1885, p. 230, fig. 

 69, belongs to the South American species. The locality is not given. Specimen 

 No. 115 from Surinam, represented in Elliot's Land and Sea Mammals of Middle 

 America and West Indies, 1904, p. 29, rig. 8, as judged from the illustration, also 

 belongs to this species. 



