864 H. H. NEWMAN AND J. THOMAS PATTERSON 
This whole complex will be, for purposes of brevity, designated 
the ‘scute,’ because the scute is the index of all of the elements 
entering into the complex. 
It has been suggested above that the bands have evolved from 
a more primitive condition of the integument—one in which the 
bony elements were not necessarily arranged into definite rows. 
This becomes obvious when one studies such adjacent parts as 
the scapular and pelvic shields. In each of these regions the 
general arrangement is much the same, but the transitional con- 
dition is more clearly brought out in the pelvic shield, and we shall 
therefore confine our account to this part. 
In the central part of the pelvic shield the bony plates are hex- 
agonal in outline, and are so closely crowded together thata 
solid bony structure is formed (fig. 16). At best the plates can 
only be said to be imperfectly arranged into rows. Toward the 
anterior margin of the shield, however, the serial arrangement into 
rows becomes more evident, and all of the plates show a distinct 
tendency to elongate in the antero-posterior direction. In the 
extreme anterior margin of the shield, or the part corresponding 
to a tenth band, they become distinctly oblong and greatly 
resemble those of the true bands. In many of them, however, 
one can still detect their hexagonal shape, although the anterior 
and posterior ends show but faint indications of their double- 
sided nature. Even in the last of the true bands, the ninth, the 
yosterior end of many of the plates is still in the form of an obtuse 
angle. 
On the upper surface of this same region of the armor the 
scutes show corresponding transitional conditions. The primary 
scutes are here slightly elevated above the more numerous second- 
aries and have their posterior ends capped with small white or 
unpigmented areas, giving to the entire pelvic shield a distinctly 
pebbled effect (fig. 21). As one passes forward on the shield 
there is noted a gradual change in the primaries from small poly- 
gonal areas to those with characteristic wedge-shaped outlines. 
This is particularly noticeable on the lateral aspects of the shield. 
In the typical regions of the pelvic shield the secondary scutes 
are more numerous than in the bands. In place of the single 
