Neotropical Mammals. 165 



Dimcnsiotis (taken on the skin) : — 



Head and body 21:5 mm.; tail 8G ; hind foot, s. u. 41, 

 c. u. 45. 



IJab. (Jampo of Province Sara, near Santa Cruz de la 

 Sierra, Bolivia. 



Type. Adult male. Collected by Mr. J. Steinbach. 



This striking species differs so widely in its coloration 

 from every known Ctenomijs that even in the absence of the 

 skull I have no hesitation in describing it as new. Its colour 

 above is extraordinarily like that of Zygoyeomys irichopus 

 and some other Geomyida^, which have a similar coppery- 

 brown tone, while all the hitiierto known Ctenomys are of 

 some fawn or buffy tint. 



A baby specimen of Ct. Steinhachi, only 100 mm. in 

 length, is of precisely the same colour as the adult. 



The Local Forms of Dasypus sexcinctus, Linn. 



While the extreme forms of the Dasypus sexcinctus group 

 are, as shown in a former paper *, so widely different in size 

 that it seems impossible for them to belong to the same 

 species, further material from intermediate localities tends to 

 fill up the gap between them, and I am now disposed to 

 regard them as forming but a single species with several 

 geographical races. 



These races may be briefly distinguished as follows : — 



1. Size smallest ; greatest skull-length 95 mm., 



cephalic shield in an average specimen 



87x05. Colom- brown. About 31-33 



scales in movable bands. Back thinly 



haired, the pelvic shield practically naked. [Linn. 



(l^ara.) D. sezcincius sexcinctus, 



2. Size medium ; greatest skull-length of adult 



114 mm., cephalic shield about 103x77. 

 Colour paler, more yellow. Hairs as in 

 sexcinctus. (Bahia.) D. s. setosus, Wied. 



3. Size largest ; greatest skuU-leugth attaining 



12(3 mm., cephalic shield 123 x 68. Colour 

 brown. Hairs as in sexcinctus, (Matto 

 Grosso, Paraguay, and South Brazil.) .... D. s. gilvipes, 111. 



4. Size rather less than in gilvipes ; cephalic 



shield 114x89 mm. Colour pale horny. 

 Movable bands with 3(5 scales. Back 

 scantily haired. Skull short and broad ; 



molars broad and rounded, (llohvia.) .... D. s. bolivicc, subsp. n. 

 6. Size as in bolivicc; cephalic shield 116x78 

 mm. Colour sandy. 36 scales in movable 

 banils. Back well haired, the pelvic shield 



with many white hairs. Nasals rather [subsp. u. 



peculiar in shape. (Tucuman.) D. s. ittciananus, 



* P. Z, S. 1903, ii. p. 212. 



