130 Mr. M. A. C. Hinton on 



Jura. 



Three, collected bv Mr. Sheppard between IGtli and 18tli 

 May, 1912 :— 



Tail, 

 Head without 

 & body. hairs. 



Average 9""6 78*5 



Maximum 100 (84) 



In this series the back is heavily clouded with black and 

 the flanks are dark ; line of demarcation straiolit and very 

 sharply defined; ventral surface clear silver, with very feeble 

 trace of the pectoral spot. In the skull the zygomatic and 

 cranial widths are relatively greater, the brain-case slightly 

 deeper, the postmolar region longer, though the bullae are no 

 larger; the nasals and diastema are shorter; the incisive 

 foramina aud masseteric plate are broader. In some of 

 these respects, as the dimensions show, there is an approach 

 towards h. hebridensis. 



I SLAY. 



Eight, 'collected by Mr. Sheppard (3rd to 9th May and 

 7th to 8th Augustj 1912)^ and two in the Royal Scottish 

 Museum : — 



Tail, Hind foot, 

 Head without without 

 & body, hairs. claws. Ear. C.-b. 1. 



Average of 9 adults., ^'ii Sl'G 22-5 14 (of 5j 22-98 



Maximum 101 85 (90) 22 (23-5) 14-5 (15) 241 



This animal is much like the ]\Iull form in external 

 appearance ; it is, however, smaller, with smaller feet, rela- 

 tively longer tail, and longer ear. The skull is distinguished 

 by its greater zygomatic and interorbital widths, broader 

 and deeper brain-case, rather larger bullse, shorter nasals 

 and diastema, and broader rostrum and masseteric plate. 

 In most of these features it makes a nearer approach to 

 h. hebridensis than do the mice of Jura and jNIuII. 



A young specimen (no. 167, female, 8th August, 1912) 

 differs remarkably from the young of h. Iiebridensis in having 

 the whole ventral surface from lip to anus of a beautiful 

 clear white ; the flanks are but slightly lighter than the 

 back, the general dorsal colour being like that of the adults ; 

 the line of demarcation is quite straight and most sharply 

 defined. The dimensions (65-04?-! 7-8) suggest that this 

 interesting pelage is an earlier one than that represented in 



