132 Mr. M. A. C. llinton on 



Apodemus fridariensis grantii, subsp. n. 



Hub. Mid Yell, Shetland. " Caught on edge of stream 

 on hill; altitude 300' " {If. K. Ogilvie-Gmnt). 



Material examined and dimensions. L'ive adults (four males 

 and one female) : — 



External characters. This form is outwardly distinguished 

 from A. f. fridariensis by its slightly smaller size and rela- 

 tively shorter tail. In coloration it is practically identical 

 with the type-form, save that a small pectoral spot appears 

 to be present constantly, and the contrast between the upper 

 and lower surfaces of the tail is much less evident. The 

 line of demarcation is unusually distinct on the flanks. 



Cranial characters. The skull differs from that ol A. f. fri- 

 dariensis in its slightly smaller size ; it has the brain-case 

 shorter and rounder, more like that of sylvaticus in form ; 

 the auditory bullse are smaller ; the nasals slope more gently 

 forwards, and the dorsal profile appears throughout Hatter 

 and less convex. In A. f. fridariensis the infraorbital canal 

 has its outer wall * unusually powerfully developed and pro- 

 jecting far in front of its roof; in the present form the outer 

 wall is much smaller, and resembles that of sylvaticus or 

 jiavicollis. In the mandible the coronoid process is as short 

 as and even more slender than in A. f. fridariensis ; on the 

 other hand, tl e angular process is exceptionally long, a 

 feature which renders it very conspicuous when compared 

 with the mandibulse of the other forms of Western Europe. 



Remarks. Large specimens from Dunrossness, at the 

 southern end of mainland, suggest that a similar form may 

 occur on that island also. I have much pleasure in naming 

 this form after its discoverer, to whom I am indebted for 

 much kindness and material. 



* ="nmsset.eric plate." 



