part 4] or elePhas antIqvvs from clactox-o^-sSA. 625 



with which I have been able to make a direct comparison is an 

 imperfect jaw of an older and considerably larger individual from 

 llford. This specimen (B.M. 21310) has been figured and 

 described by Leith Adams 1 and is noticed by H. Falconer.- The 

 former author definitely determines it as being Elephas antiquus ; 

 while the latter expresses some uncertainty. Assuming that, as 

 seems probable, Leith Adams is right in his determination, this 

 specimen (apart from its considerably larger size) shows much 

 similarity to that now described. Thus, there is a distinct beak- 

 like rostrum which passes below into a rounded chin. The rostrum 

 is, however, much smaller in proportion to the remainder of the 

 jaw than in the specimen here described ; and the anterior milk- 

 molar was not only much larger, but possessed two distinct roots : 

 in this jaw M.m.3 is present and already, considerably worn. 

 When the wear-surface is placed horizontally, the posterior border 

 of the symphysis is nearly beneath the anterior root of M.m.3. 

 Perhaps, in a still more advanced state of wear, the direction of 

 the grinding surface would be somewhat different, so that, when 

 placed in a horizontal position, the symphysis would appear to 

 extend still farther back, as in an older and larger specimen figured 

 by Pohlig {op. cit. pi. iii, fig. 1 & pi. ix, fig. 1), in which it is 

 beneath the anterior half of M.m.3. In this specimen the rostrum 

 is wanting ; this may, however, be partly due to the incompleteness 

 of the jaw. Judging from the lateral view {op. cit. pi. ix, fig. 1), 

 not only has the rostrum, but also the rounded chin, undergone 

 reduction. It seems possible that the specimen here described 

 and those figured by Leith Adams and Pohlig respectively, form a 

 series ranging from a very small, perhaps foetal, individual to one 

 in which M.m.3 is considerably worn. If this be so, it is inter- 

 esting to note the gradual disappearance of the rostrum with 

 advancing age, the loss of the distinct chin, and the carrying- 

 backwards of the posterior border of the symphysis. The presence 

 of a marked rostrum is a primitive character reminiscent of the 

 longirostrine stage through which the ancestors of all Proboscidea 

 must have passed, and is tending to disappear with advancing life. 

 At the same time, it must be noted that in some adult mandibles 

 of the Mammoth (JElepJ/as privnigenius) the rostrum is very well 

 developed, so that the degree to which it persists is variable, as it 

 very often is in the case of structures which are undergoing 

 reduction. 



Some dimensions of this specimen (in millimetres) are : — 



Anteroposterior length in a straight line (so far as preserved) ... 105 



Greatest width 128 



Length of the symjiliysis 02 



1 Op. cit. p. 14 & pi. v, fig. 2. . 



2 • Palaeontological Memoirs ' vol. ii (1808) p. 178. 



