MICBOTDS 703 



as a normal character. Upper incisors short, directed downward 

 and slightly backward, concealed by nasals when skull is viewed 

 from above. 



Measurements. — External measurements of type : head and 

 body, 107; tail, 34; hind foot, 22; ear from meatus, 12. For 

 cranial measurements see Table, p. 707. 



Specimens examined. — Two, the type, from near Bascafria, in the Sierra 

 do Guadarrama, Madrid, Spain, and a second specimen without definite 

 locality. 



6. Raseafria, Sierra de Guadarrama, M. de la Escalera (c). 6. 11. 4. 9. 



Spain. (Type of species ) 



sk. Spain. Purchased (Parzudaki). 53. 12. 6. 81. 



MICROTUS DENTATUS Miller. 



1910. Microtus cabrerse Cabrera, Asoc. Espan. Progr. Cien., Oongr. Zara- 



gosa, 1908, p. 49, June, 1910 (part). 

 1910. Microtus dentatus Miller, Ann. and Mag. Nat. Hist., 8th ser., vi, 



p. 459, November, 1910. Type in Madrid Museum. 



Type locality. — Molinicos, Sierra de Segura, Albacete, Spain. 



Geographical distribution. — Known only from the Sierra de 

 Segura. 



Diagnosis. — Similar to Microtus cabrerse of the Sierra de 

 Guadarrama, but larger, the skull about 30 mm. in condylobasal 

 length ; teeth excessively heavy, the molars larger than in any 

 other known European Microtus, the length of maxillary tooth- 

 row 8 mm. ; m 3 with a completely closed triangle on outer side. 



Colour. — Like that of M. cabrerse, but noticeably less buff, 

 the ground colour of back and sides not so yellow as the cream- 

 buff of Ridgway, the general effect a peculiar buffy grey much 

 paler than the olive or bister of cabrerse ; underparts light grey 

 scarcely tinged with buff ; no evident line of demarcation along 

 sides. 



Skull. — The only known skull is imperfect, lacking the auditory 

 bullae and base of brain-case. It is that of an individual slightly 

 older than the type of Microtus cabrerse, but of about the same 

 age as the fragmentary skull of No. 55. 12. 6. 31. Size conspicu- 

 ously greater than in either of these ; general form the same, 

 but dorsal profile less concave than in the type, especially over 

 posterior half of brain-case ; rostrum much heavier than in 

 M. cabrerse, the incisive foramina fully 1 J times as wide though 

 of about the same length ; relative lengths of nasal and diastema, 

 and form and position of posterior border of nasals as in 

 M. cabrerse ; interorbital region longer and narrower, but lateral 

 ridges and median groove not peculiar. Mandible as in M. 

 cabrerse, the base of articular process scarcely thickened by 

 upward extension of incisor root, the dental foramen lying almost 

 at extreme posterior edge. 



Teeth. — -In general the teeth are like those of Microtus cabrerse, 



