EVOTOMYS 217 



shorter and broader generally. Braincase nearly square, in- 

 stead of oblong, noticeably more depressed. Interorbital region 

 broader and shorter, retaining in adult stages of growth some- 

 thing of the condition found in young E. (jlareolus. Nasals 

 slightly more steeply inclined anteriorly, relatively longer, 

 constricted posteriorly in much the same way as, but to a lesser 

 degree than in E. skoniereiisis and E. ccesarius. Palate relatively 

 broader. Incisors straighter and with shorter exserted portions 

 than in E. g. hritannicus. Cheek-teeth very light. Enamel 

 pattern of molars normal : m"^ short with three salient angles only 

 on each side. 



Mandible distinguished by its small size, rather large angular 

 processes, and very light cheek-teeth. 



For skull measurements, see table at end of volume. 



Remarks. — This fossil species is probably more closely related 

 to E. glareolus than to any other recent species ; but the broader 

 interorbital region, square and depressed braincase, and lighter 

 cheek-teeth are characters which seem to call for specific recogni- 

 tion. In the lightness of the cheek-teeth the fossil approaches 

 E. nttilus, but the m^ is simpler than in the latter and the skull 

 form is conspicuously diilerent. 



The species is named in honour of my old friend the late 

 Benjamin Harrison, the veteran geologist of Ightham. 



2. Evotomys glareolus Schreber. 

 (Synonymy under subspecies.) 



Range. — Through the wooded lowlands and uplands of boreal 

 and temperate Europe, exclusive of the Iberian Peninsula, from 

 Scotland, Scandinavia, and corresponding latitudes in Russia, 

 southwards to the Pyrenees, Alps, Rumania and probably to the 

 shores of the Black Sea. Eastwards it ranges from Wales and 

 Scotland at least to the Syansk Mountains, 100 miles west of Lake 

 Baikal, where it ascends to 1600 feet; but the details of its dis- 

 tribution in European and Asiatic Russia are still unknown. 



Characters. — Size small; hind-foot (15-19 mm.) usually less 

 than 18 mm. ; condylo-basal length of skull in adults, with well- 

 developed molar roots, rarely exceeding 24 mm. Colour of upper 

 parts, in most of the geographical races, brighter and redder as 

 a rule than in subspecies of E. nagcri. Skull small, lightly buUt, 

 short and broad, with short and wide mesopterygoid fossa; 

 post-orbital processes of squamosals usually distinct though 

 small. Cheek-teeth normal. 



Geographical differentiation. — Eight subspecies are at present 

 recognized, and of these seven are European and one Asiatic. 

 Probably other forms remain to be discovered in European and 

 Asiatic Russia. The subspecies differ very slightly from one 

 another, the plastic characters being those of size and proportion, 

 general colour, the greater or less development of the rufous 



V.I. Q 



