276 SPOLIA ZEYLANICA. 
Nevertheless, teeth are generally considered a fairly safe 
guide,* and the Japanese author above named does not 
hesitate to found a new species (HL. leptostylus) wpon some 
peculiarities of dental structure. 
Hikoshichiro Matsumoto says on page 2 of his paper :— 
“The Pliocene horses of the old world, such as H. stenosis, 
EB. quaggoides, and E. sivalensis, are characterized by the very 
small anterior inner pillar and the more or less Hipparion-like . 
plication of the enamel of the upper premolars and molars, while 
the majority of the large Pleistocene horses, such as H. speleus, 
E. ferus, E. mosbachensis, E. germanicus, HE. abeli, as well as 
“E. caballus foss.’ of auct., &c., are characterized by the large 
and long anterior inner pillar and the less complex plication of 
the enamel of the same. Between these two groups I distinguish 
two lines of intermediation. The first, being represented by £. 
plicidens and H. sussenbornensis, has the premolars and molars, 
of which the anterior inner pillar is large and short, and the 
plication of the enamel is very complex and rather Hipparion- 
like. The second, being represented by Boule’s ‘ EL. cf. stenosis °F 
and the present species, has premolars and molars of which the 
anterior inner pillar is small and short and the plication of the 
enamel is rather simple.” 
Let us examine the Wellawatta molar in the light of these 
remarks with a view to determining where it may be placed 
in the above scheme of classification. 
The tooth is one that belonged to a full-grown horse, and 
is well worn at the grinding surface. It is quite unmineralized, 
but has lost its organic content, as may be shown by its 
adhesiveness to a moistened surface—the tip ot one’s tongue, 
say. It is short and remarkably squarish in section ; its 
weight is 49°72 grammes. The canine, which calls for no 



* Speaking of the lakes (or crescents) observable in the teeth of the 
Equidz, Professor Flower says (‘‘ The Horse,’ London, 1891, p. 126): 
‘The sinuosities of their enamel margins, which are sometimes ex- 
tremely complex, present great variations in different species, as also 
do the indentation in the edges of the sinus which runs forward from 
the inner side of tooth between the two internal columns, the form of 
the folds at the bottom of which constitutes the only easily recognizable 
distinction between the molar teeth of the common horse and the ass.” 
This distinction which I have been able to observe through the kindness 
of Mr. J. D. Brown, C.C.S.—who in his interest in the matter procured 
for me the skull of a donkey—is as follows :—The spur which projects 
into the bay between the two inner pillars (internal columns) is hardly 
represented at all, while the inlet immediately posterior to the spur 
runs up to meet the anterior crescent, (Compare with this statement 
character 6 of the table and diagram.) 
{ Les Chevaux Fossiles de Grottes de Grimaldi. Ann. Pal., V.. 1910. 
p. 113, text fig. I. 
