1900.] Allen, New American Marsupials. . 197 



on the fore neck and throat ; ears (in dry skin) pale brown ; outer surface of 

 fore and hind limbs like the sides of the body but much less fulvous and tinged 

 with gray ; fore and hind feet brown with a tinge of grayish fulvous, the toes 

 lighter and very thinly haired ; tail blackish brown above at the extreme base, 

 gradually becoming lighter, the lower surface throughout and the apical two 

 fifths whitish ; it is clothed with thick fur like that of the body for about one 

 inch at the base. 



Measurements. Total length, 606 mm. ; head and body, 296; tail, 310; 

 hind foot, with claws, 45, without claws, 41. 



Skull, total length, 59 ; basal length, 53 ; length of nasals, 27.5 ; palatal 

 length, 31 ; zygomatic breadth, 29; mastoid breadth, 18. 2; least interorbital 

 breadth, 9.3. 



Differs from M. nudicaudatus (type locality Cayenne) in its 

 darker coloration and somewhat larger size. 



Marmosa chapmani, sp. nov. 



Didelphis (Micoureus] murina ALLEN & CHAPMAN, Bull. Am. Mus. Nat. 

 Hist. V, 1893, 230. Not of Linnaeus and later authors. 



Type, No. fgff, $ ad., Caura, Trinidad, April 7, 1894; coll. Frank M. 

 Chapman. 



Very much larger than M. murina and much darker colored. Above dark 

 yellowish brown ; below pale buffy white ; black ocular spot large, extending 

 from the base of the whiskers posteriorly nearly to the ear, restricted below the 

 eye to a narrow line, expanded above the eye to a width of 3 to 4 mm., and 

 behind the eye 7 to 9 mm. ; nose patch buff, much lighter than the top of the 

 head ; ears large, pale brown ; feet yellowish, much lighter than the general 

 color above ; tail dull brown above, much paler below, hence indistinctly 

 bicolor. 



Measurements. Total length (of type), 376 mm. ; head and body, 175 ; tail, 

 201 ; hind foot, 25 ; ear from notch, 32, from crown (dry skin), i8,by 17 in 

 width. " Sixteen adult males, measured before skinning, range in size as 

 follows: Total length, 361 (340-395) mm.; head and body, 171 (155-189); 

 tail, 190 (175-218) ; hind foot, 24.4 (20-28); ear, 25 (22-29). Four females 

 measure as follows : Total length, 324 (302-365) ; head and body, 148 (132- 

 168) ; tail, 176 (163-197) ; hind foot, 22 (20-24) ; ear, 22 (20-23)." Allen & 

 Chapman, /. c. 



Skull broad, the zygomatic arches much expanded, the supraorbital bead 

 heavy, expanded at the middle in old skulls into a slight postorbital process. 

 Total length (of type), 41 ; basal length, 37 ; nasals, 15 ; palate, 21 ; zygomatic 

 breadth, 23 ; mastoid breadth, 15 ; interorbital breadth, 8.5. 



Since Mr. Chapman and I referred the Trinidad species of 

 Marmosa to M. murina, the Museum has received examples of 

 true M. murina from Brazil and Venezuela. These show that 



