6 MR. A. L. ADAMS ON THE OSTEOLOGY OF 
from fig. 6. It varies likewise in individual instances and in upper and lower molars, 
sometimes being scarcely apparent, as observed in fig. 7. The parallelism of the disks 
of fig. 7, and of all crowns like it almost worn to the enamel-reflections, is in consequence 
of the angle at which the ridges are placed, thus diminishing from above downwards 
the interval between them, which, as shown in fig. 6, is greatest towards the summits. 
Thus fig. 7 might represent a transverse section of a crown at a of fig. 6. From the 
curving of the lower molars these disks of wear show their horns directed somewhat 
forwards, the anterior macherides being slightly concave, whilst the posterior are slightly 
convex: see PI. IV. fig. 5. The outlines of the crown vary; the upper molar, however, 
is generally broad in front, narrowing rapidly towards its posterior; whilst the contour 
of the lower teeth displays discrepancies, which, in combination with other data, go to 
establish characters which will be pointed out in the sequel. 
The above are seemingly more or less common to all the Maltese fossil Elephants, to 
wit :—first, great height of plates, which differ in thickness of their ivory, cement, and 
enamel; second, mesial expansions and angulations of worn disks, with fine or faint 
crimping of the macherides. 
In some points they resemble the crown-patterns of the African Elephant and Z£. 
antiquus, only that the rhomb outline of the disk is by no means so pronounced as in 
the former; and whilst they assimilate in the height of ridges, mesial expansions, and 
angulations to E. antiquus, there is the absence of the great crimping of the enamel 
plates so generally characteristic of this species. 
As regards the numerical estimate of their ridges, collectively, they belong to Falconer’s 
subgenus Lowodon, and yield a formula almost analogous to that of Elephas meridionalis ; 
and whilst differing from one another, they equally, irrespective of the usual character of 
the milk- and true molars, display thick- and thin-plated varieties, which require careful 
study and comparison in order not to magnify or underrate their values. I therefore 
made it an object beforehand to collate all evidence on this head with respect to other 
known species of this genus. An excellent example is shown in the so-called Elephas 
priscus, which Falconer, deceived by the incompleteness of specimens and their thick 
plates, placed in the first instance in his subgenus Zoxodon ; but he subsequently regarded 
the condition as only a form of Elephas (Euelephas) antiquus'. Again, in the usually thin- 
plated molar of the Mammoth there are considerable discrepancies. Mr. Davies, of the 
British Museum, than whom yery few have had a greater experience in manipulating 
teeth of fossil Elephants, more especially of the above species, has furnished me with the 
following pertinent observations on the subject in question. ‘ From an examination of 
numerous molars of Elephas primigenius, found in England and elsewhere, I have long 
thought that there are two distinct varieties, which are easily recognized, the molars of 
one being formed of thin plates, separated by narrow intervening layers of cement, the 
other composed of thicker plates and having wider interspaces. This last form is more 
* Quart. Journ. Geol. Soc. vol. xiii. p. 319, and Palzont. Memoirs, vol. ii. p. 251. 
