566 Oil the Occurrence of Aconiys in Cyprus. 



" wood-brown," wliicli also continues for a short distance 

 along- the edges of their distal ends. Intermixed with and 

 projecting beyond these are a few long fine hairs. The 

 spines, which extend over the hinder half of the back, re- 

 semble those of A. dimidiafus in being cylindrical at the 

 base, then suddenly expanding they become laminate and 

 taper to a point. Seen in section the edges are found to be 

 folded downwards and inwards ; thus the ventral aspect of 

 the spine is deeply grooved, whilst the upper surface is very 

 slightly rounded. The roots of the spines appear as a dark 

 patch on the inner surface of the skin, which elsewhere is 

 very white. The tail, which is thicker for its length than 

 that of the above-mentioned species, is pale below, " mouse- 

 grey " on the upperside, scantily covered with short stiff 

 hairs, and has a terminal tuft of finer ones. 



The skull is slightly more robust than that of A. dimidiatus, 

 its greatest length being 32*5 to 33 millim. and its extreme 

 width 14 millim. 



The following measurements, in millimetres, of the adult 

 specimens were taken in the flesh : — 



Head and 



body. Tail. Hind foot. Ear. 



No. 153 ( 2 ) 13b 93 22 20 



No. 155 ( 2 ) Ill 72 20 21 



No. 156 ( c? , type) ..119 71 18 19 



No. 158 (c?).' 109 .. 19 19-5 



No. 159 (J) 110 .. 19 20 



No. 160 ( $ ) 106 . . 20 19 



The young differ from the adult in their upper parts being 

 entirely " moii?e-grey," with the exception of white hands 

 and feet, and in tlieir tails being comparatively longer. The 

 young of A. dlmidiatus seem to develop the speckled 

 appearance of the mature animal much earlier than those of 

 A. nesiotes ; a half-grown specimen of the former in the 

 collection of the British Museum is already changing colour, 

 while a full-grown young of the Cypriote form is still an 

 almost uniform " mouse-grey " above, shading off into " drab- 

 grey " on the flanks. 



As in other members of this group — A. cahi'rinus, for 

 instance, — the tail is exceedingly brittle, it, or its skin, be- 

 coming detached on very slight provocation, though less 

 easily in the case of the young. Tiiis also happens when 

 the mouse is in a wild state, for several tail-less specimens 

 were brought to me which had evidently lost this appendage 

 some time ])reviously. No doubt this peculiarity, as in the 



