Merriam. — Keto Pocket Mice from Mexico. 43 



Heteromys annectens sp. nov. 



Type from Pluma, Oaxaca, Mexico. No. 71,510 $ ad., U. S. National 

 Museum, Biological Survey Collection. Collected March 18, 1895 by E. 

 W. Nelson and E. A. Goldman. Original No. 7G74. 



Characters.— Size medium; tail long, slightly exceeding head and body; 

 color dark; lateral line conspicuous; sole of hind foot hairy posteriorly, 

 6-tuberculate. 



Color. — Upperparts blackish brown (nose, top of head and back mainly 

 black; face and sides mainly brown, grizzled with black); lateral line 

 bright fulvous, continuous from cheeks to thigh (in males continued on 

 sides of scrotum); underparts and feet white, the hind feet sometimes 

 clouded; tail indistinctly bicolor, dusky above, whitish beneath except 

 terminal part which is dark all round. 



Cranial cJiaracters. — Skull rather large and broad with rather spread- 

 ing zygomata and narrow rostrum. In general similar to gauvieri but 

 smaller, narrower interorbitally, with more abruptly spreading zygo- 

 mata and smaller interparietal. 



Measurements. — Type specimen: total length 300; tail vertebrae 165; 

 hind foot 33. 



Subgenus Xylomys nob. • 



Type, Heteromys (Xylomys) nelsoni sp. nov. 



Pelage soft (without stiff bristles); inner side of foreleg (between 

 wrist and elbow), and of hind leg, dark; skull light; braincase high and 

 rounded; supraorbital beads small and faint; wp^jer surface of maxillary 

 root of zygomata large, Jieavy aiid rectangular; frontals much elongated, 

 pushing nasals and premaxillte far forward; under jaw broad, without 

 trace of tubercle over root of incisor, and with angle very slightly everted. 

 Dentition heavy. Posterior prism of last upper molar more or less com- 

 pletely double, the crown of the tooth presenting two complete trans- 

 verse loops and a more or less perfect posterior loop. 



Heteromys (Xylomys) nelsoni sp. nov. 



Type from Pinabete, Chiapas, Mexico. No. 77,920 $ ad., U. S. Na- 

 tional Museum, Biological Survey Collection. Collected February 11, 

 1896 by E. W. Nelson and E. A. Goldman. Original No. 9281. 



Characters.— S\zQ very large; ears large; tail very long, much exceed- 

 ing head and body and nearly naked; color grayish dusky; sole of hind 

 foot naked, 6-tuberculate. 



Color. — Upperparts, including fore and hind legs (except basal part of 

 underside of foreleg and indistinct streak on hind leg), mouse gray, 

 darkening to dusky on top of head and along middle of body; under- 

 parts including upper lip, fore feet, basal part of inner side of fore leg, 



