ON THE DERMAL ARMOUR OF JACARE AND CAIMAN 309 
the median line. In the three hinder rows the inner scutes are longer. 
than the outer ones; and this is most markedly the case in the 
fifteenth row, whose innermost scute is half as long again as the 
‘corresponding one of the preceding row, and more than three times’ 
as long as the outermost of its own row. 
The sixteenth row differs from its predecessors and successors, and 
may be termed the axillary row. It is bent upon itself with an angle 
-open forwards, and is divided into two halves (each of which contains’ 
seven scutes) by the union of the middle scutes of the fifteenth sub- 
cervical with those of the first row of what may be termed the 
subdorsal scutes, or those which lie under the thorax and abdomen. 
Of subdorsal and subcaudal scutes there are, up to the broken-off end 
of the tail, thirty-seven rows, with the following numbers of scutes :— 
Rows. Scutes. Rows. Scutes. 
Vicerrawiiedd gatnn ao 6. 2 awncane <2 OD contains: sam acumen 18 
DB bisccs tha cis ean cR pentane Se fe) 23 22 
BA IG, ceacins. ae. aeaiemncwieind 12 DA criesctanerohnen tesneeaseceeaterernh 22 
G5 Fy By Onasnesnane qx 14 DG scteuidte. carmen nenamtvacatiatec 20 
103 sanatmuntee nies yancimeee 16 BOBS icasscang. —daarvanys 18 
VD. vesasacsecaus 14 ZO Bil sina csineamaainge. oh aheye 16 
12—I7 14 2H 34s sche. —seagernhye hae 14 
TS 20» pecan sees sem 12 DE nope nenoatuanente dameer oh 12 
SE. adhe Gust p.bem aceon 14 86537 tue ties amore cayenne 10 
It will be noticed that there are three more rows of ventral than 
of dorsal scutes. On endeavouring to ascertain how this came about, 
I observed that the first subdorsal was a good deal behind the first 
‘dorsal row, though the eighth to the twelfth dorsal corresponded 
exactly with the eighth to the twelfth ventral rows. In the anterior 
part of the body, therefore, there is a clear general correspondence 
between the segments of the dorsal and those of the ventral armour. 
In the caudal region, again, I found that the twenty-fourth ventral 
row, which is the first of the caudal rows not excavated by the vent, 
-corresponded exactly with the twenty-first dorsal row. It was clear, 
therefore, that three ventral rows were interpolated somewhere be- 
tween the twelfth and twenty-first dorsal rows ; and on close exami- 
nation I found this interpolation to arise from the doubling of the 
fourteenth, fifteenth, and sixteenth ventral rows. 
I have examined /acare fissipes and nigra, Caiman trigonatus, and 
.C. gibbiceps, in the British Museum ; and I find, in all, dorsal and 
ventral armour having the same essential arrangement as that just 
described. A specimen of Caiman palpebrosus about two feet long, 
the opportunity of examining which I owe to Dr. Grant, exhibits the 
dorsal and ventral shields (whose scutes are in the main similarly 
