44 Preble — Neiv Lemmiii;/ Mouse froiii ]Vhitc 3Ionnt(iiits. 



General dKivacli'Vi^. — l^arger than aS'. Itiimilns, with larger skull and lonj^er 

 hind foot and tail. 



Color of Ujpe. — U])i)er parts sepia brown, quite thickly interspersed with 

 black-tipped hairs, the fur basally blackish slate; each side gland 

 marked with white ; under parts grayish white ; inside of ears slightly 

 darker than general color of upper parts ; a few hairs at base of ears and 

 on sides of cheeks, light chestnut ; tail quite sharply bicolored, the upper 

 and lower sides concolor with body. 



Cranial chnrncters. — Compai'ed with the type of Syiiaptomys innuUus, 

 which is approximately of the same age, the skull. of 8. spJiagnicola is 

 much larger and longer ; interorbital constriction considerably longer and 

 narrower; rostrum longer and stouter; braincase more lengthened pos- 

 teriorly ; posterior production of zygomata straighter ; incisive foramina 



much lai-ger and slightly longer 

 proportionally ; post -palatal 

 pits deeper and median i-idge 

 correspondingly conspicuous ; 

 audital bullre longer and more 

 rounded ; pterygoids more di- 

 verging ; mandible larger and 

 stouter, with condylar pro- 

 cesses broader proportionally. 

 Denial cJiaracters. — Com pared 

 with *S'. mnuitus, the molars are 

 heavier and molar series consid- 

 erably longer ; enamel pattern 

 of molars not essentially differ- 

 ent, though the posterior prism 

 Fig. 3.-a, Type «kiill of Sijnaptomijs (Miciomij^) of the last upper molar is more 



sphngnicola; b, type .skull of Synaptomys [Micto- ti-jj^ng^j^r. Inner faceS of tlie 

 iiiys) innuitus. X IJ^- . . , 



upper incisors much exca- 

 vated medially, with the edges 

 exterior to the sulci about one millimeter longer than remaining portion 

 of the teeth, and ending in sharp points. Enamel faces of incisoi's i)aler 

 orange than in the type of 6'. innuitus. 



Measurements.— Type of S. spJiagnicola {in Hesh) : total length 132; tail 

 vei'tebree 24; hind foot 20. Type of aS'. innuitus (in alcohol) : total length 

 115; tail vertebrpe 17; hind foot 17.5. 



Cranial measurements of tijpe. — Occipito-nasal length 27.5; basilar length 

 26; zygomatic breadth 16; mastoid breadth 12; interorbital constric- 

 tion 28 ; length of nasals H ; length of incisive foramina 5.5 ; upper molar 

 series, 7. Ty])e skull of »S'. innuitus (No. 24729, U. S.. Nat. Mus.) : occipito- 

 nasal length li).6; basilar length 18.3; zygomatic breadth 15; mastoid 

 breadth 11.5; interorbital constriction 3.1; length of nasals 6.3; length 

 of incisive foramina 4.8; upper molar series 6.5. 



Gcner((l remarks. — The discovery of a sj)ecies of Midomys in the White 

 Mountains, within the limits of the Canadian Zone, and at a compara- 

 tively low altitude (al^out 1 ,600 feet) is one of the many surprises that mod- 



