a new Species o/'Eligmodontia. 483 



Eligmodontia marica, sp. n. 



Size smaller than in other species. Fur soft and fine, hairs 

 of buck about 7 rain, in length. General colour above pale 

 sandy buff, darker along the back, paler on the sides where it 

 is nearly "pinkish buff." Whole of under surface pure 

 sharply defined white, all the hairs, even laterally, white to 

 their bases. Middle of face and crown darker buffy like 

 the back, area between eyes and ears, and a patch above each 

 eye paler like- the sides. Ears large, the usual piebald 

 {ii-'.-angeinent of their colour strongly marked; a whitish patch 

 at base of proectote, middle part of proectote nearly black, 

 terminal part and whole of metentote greyish buffy, the line 

 haiis along the edge while. Limbs wholly while, the buffy 

 body-colour not or scarcely encroaching on the white of the 

 Upper arms; palms and soles with the structure characteristic 

 of Eligmodontia, but the hairy covering quite thinly spread. 

 Tail longer than head and body, dull buffy above, whitish 

 below, the contrast not so marked as it is in the southern 

 species. 



Skull markedly smaller than that of the other species, 

 especially as compared with that of the forms geographically 

 nearest. 



Dimensions of the type (measured in the flesh) : — 



Head and body 65 mm.; tail 93; hind foot 20; 

 ear 15. 



JSkull : greatest length 21'4 ; zygomatic breadth 12 ; 

 nasals 8; interorbital breadth 3*8; breadth of brain-case 11 ; 

 palatdar length 9*3 ; palatal foramina 4'8 ; upper molar 

 series 3'5. 



Hab. Chumbicha, Catamarca. Alt. 600 m. 



T,,pe. Young adult male. B.M. no. 18. 11. 11. 1. Original 

 number 311. Collected 30lh July, 1918. Presented by 

 Old held Thomas. 



This beautiful little mouse is the smallest species of the 

 genus and is readily distinguishable by size from E. hirtipes 

 and morenij occurring north and south of it respectively. 

 E. fypi's, with which the Bahia Blahca elegant is always 

 assumed to be synonymous, is also larger, and the belly-hairs 

 are broadly slaty at base. The more southern E. morgani has 

 a proportionally shorter tail. 



fch\. Budin says of E. marica: — "This pretty mouse has 

 been the one which has most pleased and interested me of all 

 the rodents. It was caught among the prickly pears 

 [' peneas '] in one place only, in a space some 40 square 



35* 



