23S Goldman — New Mammals from Central and South America. 



direct comparison. It is well marked externally by the greater extension 

 of the black orbital areas. The type, and only known specimen is in 

 a much worn pelage, and would doubtless lie brighter colored in the fresh 

 coat. 



Marmosa zeledoni * sp. nov. 



Type from Navarro, Costa Rica. No. ifftf> c? adult, U. S. National 

 Museum, collected by Juan Cooper, for Jose C. Zeledon, March 1, 1878. 



General characters.- — Allied to mexicana, but color darker, more rufes- 

 cent, the line of demarcation between whitish under parts and huffy sides 

 very sharp; interparietal narrower. Somewhat similar to mitis, but color 

 decidedly darker, and skull quite different. 



Color. — Upper parts cinnamon-rufous, becoming lighter on middle of 

 face, and paling to ochraceous huff on cheeks, sides of neck, and flanks, 

 the latter color encroaching on under parts along sides of belly where the 

 fur is basally plumbeous; throat, chest, median line of belly, inguinal 

 region, and inner sides of limbs yellowish white, the hairs whitish to 

 roots; ears brown; orbital area black; fore feet brownish; hind feet 

 soiled white; tail light brownish. 



Skull. — Similar to that of mexicana, but interparietal narrower, less 

 extended laterally along lambdoid crest. Somewhat like that of mitis, 

 but braincase larger; interorbital region broader; supraorbital and 

 temporal ridges more widely separated. 



Measurements. — Type (dry skin): Total length, 345; tail, 168; hind 

 foot, 23. Skull (type): Greatest length, 36; zygomatic breadth, 19.2; 

 nasals, 16.2 x 4.4; interorbital breadth, 6.5; palatal length, lS.-_'; three 

 anterior molariform teeth, 5.2. 



Remarks. — This form is probably most closely allied to mexicana, but 

 is readily distinguished by richer color. The supraorbital and temporal 

 ridges in mexicana and zeledoni are widely separated, and especially in 

 the latter, extend backward across the parietals in nearly parallel lines. 



Specimens examined. — Five, from localities as follows: Costa Rica, Na- 

 varro (type locality), 2; Nicaragua, Escondido River, 3. 



Proechimys steereit sp. nov. 



Type from Rio Purus, a southern tributary of the Amazon, in north- 

 western Brazil. No. 105,535, cT adult, U. S. National Museum, collected 

 by J. B. Steere, in 1901. 



General characters. — Size medium ; color dark and rich ; ankles dusky 

 all around; tail rather short, thinly haired; skull without temporal 

 ridges. Closely resembling semispinosus in color, and in arrangement 

 and stiffness of dorsal spines, but skull more like that of trinitaiis. 



Color. — Upper parts between orange rufous and ferruginous, lined with 

 black, the color richest and darkest along median line of back, fading to 

 huffy grayish or brownish on cheeks, flanks, and outer sides of limbs; 

 under parts and inner sides of limbs pure white, abruptly interrupted at 



* Named for Mr. Jos6 C. Zeledon, the well-known Costa Rican naturalist. 

 + Named for Dr. J. B. Steere, the naturalist and traveler. 



