234 MICROTIN^ 



expanded in front, their median portions parallel. Auditory 

 bullae large, but of normal form. 



Cheek-teeth unusually large ; pattern normal ; 7)i^ usually 

 with third inner infold ; m^ with very short anterior loop. 



For external and cranial measurements, see tables at end of 

 volume. 



Remarks.- — This interesting insular representative of the 

 nageri group presents a very strong superficial resemblance to the 

 typical alpine form, but is readily distinguished by its darker 

 feet, shorter tail, and much larger and stronger skull and 

 teeth. 



9. Evotomys alstoni Barrett-Hamilton and Hinton. 



1913. Evotomys alstoni Barrett-Hamilton and Hinton, Abstr. Proc. 

 Zool. Soc, No. 119, p. 18, and P.Z.S., 1913, p. 827; Barrett- 

 Hamilton, Hist. Brit. Mamm., 1914, 2, p. 422. 



Tijpe.—^M., No. 14.1.30.4 ; old male, skin and skull, collected 

 by R. W. Sheppard, June 18, 1921. 



Type locality. — Island of Mull, Inner Hebrides, Scotland. 



Range. — Known only from the type locality. 



Characters. — Size rather large (hind-foot 18-19-5 mm.; 

 condylo-basal length of skull 24-1-25-3 mm.) ; with relatively 

 short ears and tail, long hind-feet, and peculiar skull. 



Colour similar to that of adults of the deeply tinted forms of 

 E. glareolus ; deep russet above ; under surface richly washed with 

 yellowish or buffy tints. 



Skull larger than in E. g. glareolus, agreeing in size with that 

 of E. n. norvegicus. As in the latter form, the jugals are heavy; 

 but the curvature of the zygomatic arches is as in E. g. glareolus. 

 Braincase very broad and smoothly convex, the temporal ridges 

 but faintly indicated even in aged skulls ; parietal region convex 

 instead of being flattened in dorsal profile, the highest point a 

 little behind the middle of the jaarietals ; these features impart 

 an appearance of relatively greater cranial capacity than is seen 

 in any of the other European species of the genus. Post-orbital 

 (squamosal) processes not conspicuous. Interorbital region 

 broad, with a wide shallow median sulcus. Nasals rounded or 

 slightly and narrowly emarginate behind, ending flush with or 

 slightly behind the ends of the premaxillse, slightly longer than 

 the diastema, exj^anded in front, their lateral borders slightly but 

 distinctly concave. Rostrum shallow, as in E. n. norvegicus, its 

 least depth behind the incisors not exceeding the anterior width. 

 Auditory bullae nearly as in E. n. norvegicus ; m^ with a third 

 inner fold and fourth inner salient angle, the latter usually well 

 develoj)ed. 



For external and cranial measurements, see tables at end of 

 volume. 



