new Subspecies of Spalax monticola. 315 
groove. Of the faint coste found frequently in turcicus by 
Méhely I can see no trace in thermaizcus. 
Cheek-teeth.—In adult stages of wear the patterns of the 
cheek-teeth are exactly similar to those of turcicus. The 
anterior sulcus separating the two tubercles of which the 
front lobe of ™-! is originally composed (¢/. Méhely, Mamm. 
p. 296, fig. 9) is always ephemeral in thermaicus, though 
sometimes persistent in turcicus. In thermaicus the young 
m-2 ig quite like ™1, having three re-entrant enamel folds on 
the labial side instead of the single ‘“‘ zweibuchtige”’ fo'd 
found in turcicus; the posterior or third labial fold is very 
small, it is quickly reduced to an islet, which, in turn, 
speedily disappears: ™:1 and ™? have each to begin with 
three lingual re-entrant folds (in addition to the labial fold) ; 
but the posterior labial ‘‘ fold” commences as an islet in the 
posterior lobe of the tooth ; the two anterior labial folds have 
2 common mouth on the side of the tooth and are separated 
from each other internally by a small saliency formed by the 
posterior horn of the half-moon-shaped anterior moiety of the 
young tooth. In the za of my youngest specimen this 
saliency appears as a separate tubercle uot yet united with 
the main mass of the tooth. 
Molar roots and the alveolii—The molar roots tend to be 
reduced by fusion in thermaicus, while they remain free and 
distinct in ture/eus. In the latter ™1!, according to Méhely, 
is always distinctly three-rooted, having two labial roots and 
a lingual root, which tends to be forked ; correspondingly 
the alveolus has three distinct cells, that for the lingual root 
showing two depressions. In thermaicus the anterior labial 
root is very short and it is completely fused with the lingual 
root, being separated from the latter merely by a faint 
crease ; a furrow also divides superficially the large lingual 
root into two parts; the posterior labial root is completely 
free, though short. The alveolus hasa special cell with com- 
plete walls only for the posterior labial root ; its remainder 
shows three depressions—a shallow one for the anterior root 
and two deeper ones for the lingual root. In thermaicus ™? 
is similar to “1 as regards roots and the alveolus; but the 
division of the lingual root only becomes perceptible towards 
the tip, and in the alveolus the septum dividing the cell for 
the posterior labial root from the remainder of the alveolus is 
lower and thinner. In ¢urcicus this tooth has three distinet 
roots, of which the linguai is always more or less distinetly 
forked, while the alveolus is correspondingly four-celled. In 
turcicus ™:3 also is provided with three completely free roots, 
