450 ~ Mr. J. L. Bonhote on 
two am in no position to give a definite opinion; they are 
merely included to show in what relationship they stand to 
the group as a whole, and in order that any future worker 
may bear them in mind when studying this group. On this 
last race, however, I feel compelled to make a few remarks, 
Mr. Miller starts his description by giving as its distinctive 
characters, ‘‘ Skull with more slender rostrum and smaller, less 
inflated audital bulle,” both characters being comparative. 
In the study of comparative characters one naturally looks at 
the dimensions, in order to get some idea of the amount of 
the difference between the two forms; and in this case we are 
met with the announcement that “ The skull is so nearly 
alike that of S. anambensis in size, that it is unnecessary to 
give detailed cranial measurements.’ In other words, were 
it not for a description of the audital bulle we should have a 
species characterized by comparative features of size alone, 
which are incapable of being demonstrated on paper by 
measurements. It will, perhaps, make my meaning clearer 
if I quote Mr. Miller’s description in full:—‘ Skull much 
like that of S. anambensis in size and general form. ‘The 
rostrum is more slender, particularly when viewed from 
below, and the audital bullee are noticeably different in 
form. ‘The bulle are so flattened that when viewed from 
behind (the skull held upside down) they appear to rise 
scarcely above the level of tips of hamulars. Hach is con- 
stricted near the middle by a groove extending from just 
behind the lateral process of basioccipital over the ventral 
ridge of the bulla and disappearing on the outer side. ‘This 
groove, faintly indicated in the related species, is here so 
greatly developed as strongly to affect the shape of the bulla, 
articularly when viewed from the side.” 
The distinction of the groove on the bulla, although more 
pronounced in Mr. Miller’s specimens, is, judging trom the 
analogy of the skulls of other races of S. vittatus, a very 
variable feature, two skulls from the same locality in Borneo 
showing varying degrees of constriction. The only charac- 
teristic of this species left, therefore, is that the bulls are so 
flattened that ‘‘when viewed from behind (the skull held 
upside down) they appear to rise scarcely above the level of 
tips of hamulars.” | 
T should be the last to maintain that such small differences 
where they exist should be disregarded, and, in fact, the less 
obvious they are the more interesting are they likely to prove 
in future ages, as showing what may be the first incipient 
beginnings of a definite species; but when these differences 
are so minute as to be incapable of being definitely expressed, 
