THE MALTESE FOSSIL ELEPHANTS. 3) 
constant, whilst also, as seen in the same figure, instead of being erect, several of the 
last plates and posterior talon are reclinate, a condition common enough in the last true 
molars of other species. ‘The external surface of a plate when denuded of cement, 
presents, as seen in Plate II. figs. 3 & 5, perpendicular ridges more or less parallel, 
and always situated towards the middle of the plate, their number varying in plates of 
the same molar ; however, as seen in fig. 3, they are more or less concurrent with the 
central digitations. Their outline varies considerably, being either rounded or sub- 
angular; but there is usually one much larger than the others, with its inner surface 
hollow and triangular, so as to form “the angulation,” which is a prominent feature of 
the disk when ground down below the digitations. 
Besides these prominent ridges there are numerous small and finely defined ribs 
separated by inosculating channellings, which converge and become faint towards the 
digitations, as seen in fig. 5. Again the outer surface of the enamel is marked by 
transverse wrinkling or wavy puckerings, which are extremely fine in germ molars ; 
whilst in teeth in wear they become rough and granulated, in order that the cement 
may be firmly attached to their surfaces. The figs. 4 & 4a display the interior surface 
of a plate, against which the ivory is packed. Here the only feature on the enamel is a 
series of vertical strie like the external channellings, with the above-mentioned ‘angular 
expansion” forming a furrow with abrupt sides, sometimes extending up and down 
in an unbroken or an irregular manner. It is situated, in upper molars, about the 
middle; and in lower, from the arcuation of their crowns, it is usually ex-central. Its 
abutment on the macherides of the enamel not only increases the triturating capabilities 
of the crown-surface, but, as just remarked, it forms a conspicuous feature on all well- 
worn disks. 
These channellings, puckerings, and angular expansions vary considerably ; the latter, 
however, are always present at some time or other during the attrition of a plate, their 
absence being usually noticed in newly invaded crowns, which, when half worn, often 
display the “angulation” in a pronounced degree. ‘The transverse section, as in fig. 7, 
shows a granulated outline on the cement side of the enamel, which is caused by the 
above-mentioned rugous channellings and wavy lines. These, in descriptions of the disks, 
are named by Falconer “ false or spurious crimping.” I shall allude to the condition 
frequently, using the expressions “false” or “faint” crimping according to the nicety 
or obscurity of the appearance. 
It is evident therefore that the irregularities of the macherides of worn disks are 
owing to the above conditions, whilst the digitations and their obliquity, together with 
their intervening sulci, furnish the irregular and often excessive festooning of newly 
invaded crowns. Whenever the enamel is very thick its surface-roughness is not so 
well developed ; and even in thin-plated molars it is not always pronounced. 
Besides these characters there is, especially in lower molars, a central expansion of 
the disk, which increases when the wedge is being ground down to a@, as may be supposed 
