FOOTMARKS IN THE SANDSTONES OF CUMMINGSTONE IOI 
the disposition of the dermal armour, as will be shown below, is very 
different. The most numerous scutes are on the ventral surface of 
the thorax and abdomen, where they form six longitudinal, and as 
many as twenty transverse rows. In the dorsal region, on the other 
hand, no distinct nuchal and cervical scutes have as yet been dis- 
covered; and in the dorso-caudal regions, the scutes, which are 
occasionally very large, and are usually broad in proportion to their 
length, never form more than two longitudinal rows, the scutes of 
each row being suturally united in the middle line, and free at their 
outer edges. There is no evidence of the existence of any scattered 
small scutes, or that anything but soft parts united the dorsal with 
the ventral shield. 
Such are the chief modes in which the dermal armour of the 
Crocodiza is disposed. With respect to the form and mode of union 
of the component scutes, it does not appear that many general rules 
can be laid down. The scutes are, however, always disposed sym- 
metrically with regard to the median planes of the back and belly, in 
such a manner that the middle line answers to the interval or suture 
between two longitudinal rows of scutes. 
The dorsal scutes almost always present a more or less marked 
longitudinal ridge externally, while the ventral scutes, when they 
exist, have either flat and smooth, or evenly curved external 
surfaces. 
In some proccelian recent Crocodilia, such as Crocodilus acutus, 
there are no ventral osseous scutes. The dorsal scutes, on the other 
hand, are well developed; they are either square, pentagonal, or 
hexagonal, and their lateral edges are very irregular and jagged. I 
cannot find in any case, however, that they interlock so as to unite 
suturally,—a greater or less portion of the dermis being in all cases 
interposed between their edges. The scutes nowhere overlap, and, as 
might be expected, they exhibit no articular facets. 
Each scute presents externally a strong longitudinal ridge, which 
lies on the outer side of the median line, and cuts the hinder margin 
of the scute posteriorly, while anteriorly it subsides into the general 
not aware that there is any evidence to show whether these scutes were dorsal or ventral, or 
in what manner they were arranged. Their sculpture consists of distinct pits; but the peri- 
pheral pits are not particularly elongated, and hence there is no marked appearance of a 
radial arrangement. 
1 The only exceptions to this rule that I am acquainted with are offered by the scutes of 
the median caudal crest, and by a small extent of the dorsal region of the tail, just in front 
.of the point of convergence of the lateral crests, Here there is a variable number of scutes, 
which lie one behind the other, gradually diminishing in size, in single series, so that their 
centres correspond with the median line. 
