170 GEOLOGICAL SURVEY OF THE WERRITORIES. 
dias by the decisions of such a system, as the condition just referred to 
is found to be present in both of these birds. 
There is no distinct manubrium in the sterna of the Cathartide, as we | 
findin Neophron and among the Hawks; this feature being supplanted 
by a massive and tuberous promontory in the median line, over which 
the broad concave coracoidal grooves meet at the middle point above, 
to be produced shallower, narrower, and less distinct to the deep pneu- 
matic fosse that are found on either side, just below the facet of the first 
sternal rib in the costal border, in all of these Vultures. The body of 
the sternum is oblong and deeply concave, being wider behind than it 
is anteriorly, and longer for its width in Catharista than any other. 
The general internal surface is very smooth, and so evenly distributed 
is the concavity that marks it that no distinct furrow defines the po- 
sition of the carina below, as in so many other birds. All of the bor- 
ders are sharp and thin, except the anterior moieties of the lateral 
ones, that are more (Pseudogryphus) or less (Cathartes) occupied by the 
facets for the sternal ribs. These are small parallelograms, varying in 
size according to the rib they support, placed transversely and tipped 
slightly outwards, being separated from each other by subelliptical de- 
pressions that show the pneumatic openings at their bases. Beneath, 
the body is likewise smooth, and presents for examination the prominent 
pectoral ridges on either side, originating in eminences in the middle 
of the costal borders to be produced backwards and terminate just an- 
terior to the mid-xiphoidal process, at the base of the keel. This lat- 
ter is very deep and strong in all of the Cathartide ; commencing be- 
low and within the manubrial prominence, it is carried out, mesiad, to 
the very posterior end of the bone; its anterior margin is always thick- 
ened, but in the Condors and Gyparchus the entire inferior rim is found 
to be very much more so; in this latter Vulture, too, we observe that the 
anterior carinal margin is wider above and scooped out throughout its 
extent, having the fine median line passing down from the manubrial 
eminence to the carinal angle, that is present in all of these birds. A 
well-marked muscular line is found on either side of the keel, a few mil- 
limeters within its inferior boundary, extending from the carinal angle 
to be gradually lost before arriving at the posterior termination of this 
plate. It is less distinct in Gyparchus and the Condors. 
_ There seems to be no exception among the Cathartide as to the fact 
that the xiphoidal end of the sternum exhibits many patterns for the 
same species; a circumstance that may be due to slight differences in 
age, but which certainly robs this bone in this family and in others 
where it may occur of a great share of its importance as possessing 
distinctive character inthisrespect. Itis not strange, then, that scarcely 
two drawings agree as presented us by divers authors and ornithologists, 
much less any two verbal descriptions, so that, as far as these Vultures 
are concerned, a question of accuracy has arisen on many occasions, on 
the part of one observer examining the work of another, when, perhaps, 
a mistake very rarely occurs with any of us in one description of the con- 
dition in which we found the notches or foramina at the xiphoidal end 
of the sternum in any of these American vultures. 
One pattern is shown for C. aura in Plate XXIII, fig. 122, from a 
Specimen secured in Wyoming by the author, and we will give a few out- 
line sketches here as the best means of showing the wonderful diversity 
that may exist, not only for the bird we have just mentioned, but for 
all, and even this characteristic is extended to the Old World Vt ltures 
(Neophron). 
