94 Proceedings of the Biological Society of Washington. 



Melasmothrix naso, sp. nov. 



Type from Rano Rano, Middle Celebes. Skin and skull of old d^ (teeth 

 much worn); No. 219,752, U. S. National Museum; collected January 2, 

 1918, by H. C. Raven; original number 3368. 



Characters. — Size, color, quality of fur and general appearance apart 

 from the long fore claws much as in the South American Melauomyx 

 caliginosus. General coloration a rich blackish-bay; hairs with underfiu- 

 broadly slate color and tips of golden brown; mixed throughout are some 

 slightly longer hairs wholly of glossy black. Underparts scarcely differing 

 from back and sides, glossy like upperparts but slightly less dark. Hands, 

 feet, ears, and tail brownish black. 



Skull. — In general form the skull resembles that of Echiothrix leucura, 

 but the braincase is relatively larger, the rostrum less elongate, and the 

 contours are all smoother and more rounded. The anterior border of the 

 zygomatic plate is scarcely visible when the skull is viewed from above, 

 while in Echiothrix it is a conspicuous feature. The dorsal surface of the 

 nasals, essentially flat in Echiothrix, is noticeably concave at a level slightly 

 behind that of the incisors. Glenoid surface not carried forward as a 

 distinct shelf projecting into posterior region of the temporal fossa, and 

 posterior zygomatic root not standing abruptly out from side of braincase. 

 Auditory bullae relatively larger than in Echiothrix, their form broad and low 

 rather than narrow and high. Mandible resembling that of Echiothrix 

 but with coronoid process more posterior in position relatively to angular 

 process, and masseteric ridge crossing jaw obliquely and terminating 

 beneath middle of toothrow, the position of the ridge obviously correlated 

 with that of the zygomatic plate. » 



Measurements. — Type: Head and body, 124; tail, 90; hind foot (dry), 

 28; hind foot without claws, 26; middle hind claw, 2; middle fore claw, 5. 

 Skull: Condylobasal length, 31.0; condyloincisive length, 28.6; zygomatic 

 breadth, 12.4; interorbital constriction, 6.2; breadth of braincase, 14.2; 

 depth of braincase at middle, 8.6; nasal, 12.5; diastema, 7.8; width of 

 palate at middle of m^, 2.8; width of palate at middle of m^ 3.8; mandible, 

 17.2; maxillary toothrow (alveoli), 5.0; greatest width of m', l.S; greatest 

 width of m', 1.0; mandibular toothrow (alveoli), 4.6. 



Specimen examined. — One, the type. 



Remarks. — Mr. Raven's field catalogue states that this specimen was 

 caught in a trap set under rotten, moss-covered logs. The sujierficial 

 resemblance in the structure of the head to Echiothrix was noted by him. 



Eropeplus, gen. nov. (Murinae). 



Type. — Eropeplus canus sp. nov. 



Characters. — Like Lenomys but cheekteeth distinctly hypsodont (the 

 crown of m' about as high as wide), f»nd enamel pattern simplified in the 

 direction of separate transverse plates ; tubercles at outer side of maxillary 

 teeth reduced in size and not sufficiently elevated to form a longitudinal 

 groove between the outer and middle series; m^ with only two tubercles on 

 outer side; m^ without trace of x-cusp, the two inner tubercles tending to 

 become isolated from the median tubercles. 



