780 



RODENTIA 



region obliquely truncate posterioi-ly, so that condyles are plainly 

 visible when skull is viewed from above, very low and wide in 

 posterior aspect ; postorbital ridges low but evident, slightly 

 angled ; temporal ridges continued back across frontal and 

 parietal to outer edge of interparietal, abruptly angled at middle 

 of parietal. Auditory bulhe very small and low, their greatest 

 diameter contained about four times in coudylobasal length of 

 skull (about 3 to 3h times in lusitanicus, marise, and pelandonius), 

 their surface rather smoothly inflated. Palate with well-defined 

 grooves asd rather shallow lateral pits exceeding in breadth 

 the flattened median ridge. 



Teeth. — The teeth show no peculiarities as compared with 

 those of other members of the group. 



Measuremenis. — Type (adult female) : head and body, 85 ; 

 tail, 25; hind foot, 13; ear, 8. Two adult females from the 

 type locality : head and body, 85 and 93 ; tail, 29 and 23 ; hind 

 foot, 14 and 14; ear, 7*5 and 8. For cranial measurements see 

 Table, p. 788. 



Spcchnens examined. — Thirteen, from the following localities in Spain : 

 La Granja, Segovia, 6 ; Rascafria, Madrid, 6 ; Villalba, Madrid, 1. 



6 al. La Granja, Segovia, Spain. M. de la Escalera (c). 8. 7. 30. 9-14. 

 ? & 5 al. Rascafria, Madrid. M. de la Escalera (c). 6. 11. 4. 10-15. 



(6. 11. 4. 15. Type of sj^ecies.) 

 9. ViUalba, Madrid. 0. Thomas (p). 8. 2. 9. 212. 



(N. Gonzalez). 



PITYMYS IBERICUS Gerbe. 

 (Synonymy under subspecies.) 



Geograioliical distribution. — Probably the entire Iberian Penin- 

 sula, though at present known only from central and southern 

 Spain. 



Diagnosis.- — Larger than Pitymys lusitanicus and its allies 

 (hind foot, 15 to 18-4 mm., condylobasal length of skull, 24 to 

 25 mm. or more), and adaptation to underground life more 

 complete ; skull with brain-case less evidently parallel-sided, its 

 outline in many individuals almost sub-orbicular ; upper incisors 

 long, conspicuously protruding, nearly their entire front face 

 visible when skull is viewed from above ; colour usually rather 

 pale, ranging from hair-brown to a light bufly drab. Habits 

 strictly subterranean. 



External characters. — General form diflfering rather con- 

 spicuously from that of Pityvms subferraneus and Microtus arvalis 

 in its much more evident adaptation to underground life, the 

 head large, with incisors noticeably protruding from mouth, 

 the neck short and thick ; eai's much reduced, almost hidden in 

 the fur ; feet strong and robust, the hind foot shortened and 

 broadened, the digits and claws of both front and hind feet 



