Senores, i Perigrinos." Possibly at some period during the occupation of the City of Machu Picchu, only persons of high rank, by birth or through connection with the service of the Temple and the Acclahuasi, were accorded the privilege of interment on the Machu Picchu Mountain, and the individual whose remains were found in this cave, not being one of the elect, may have been forbidden burial in holy ground.

### Cave 105.

This cave was on the west side of Huayna Picchu, its location being recorded in the same words as that of Cave 94. The Indian collecors brought in no skeletal material whatever, the booty consisting of nothing more than a sherd from the base of an olla, a seed, and two pairs of bronze tweezers (M. P. Coll. 699, 670). I have searched in vain for any indication that this cave was the same as Cave 94.

### Cave 106.

From this cave, on the east side of Huayna Picchu, the following specimens were collected: "A few sherds of no account, three or four rotten pieces of bones, and a curious rounded piece of bronze with two small horn-like projections at one end." The bronze piece has been figured in the National Geographic Magazine for February 1915 as a "small bronze bell."

Cave 107.

This burial cave, the last one excavated at Machu Picchu, was situated "at the foot of the hill east of the city." By this, I understand that it was near the foot of Mr. Heald's trail, and on the Machu Picchu side of the river, not on the far side of the stream as was Cave 104. The foot of the mountain offers many of the same natural facilities for cave-burial as the higher slopes; and the subjects of the Incas, or their predecessors, were familiar with the locality, having, at some distant period, constructed an- denes along the riverside at this point. In fact the south- western bank is here protected from the torrent by an immense andean retaining wall, massively constructed of roughly shaped granite blocks.

Remains of three individuals were collected. One of them was a young man of highland ancestry (Ost. Coll. 3247) about twenty-one years of age, and perhaps not quite fully developed. His youth may therefore partly account for the somewhat effeminate appearance of the skull, which although of fair size, as shown by the measured cranial capacity of 1428 ccm, is still notably lacking in the development of those characters that usually indicate the male sex. Al- though the pelvic bones were not recovered, the size and proportions of the humeri and femora, and especially of

their proximal articular condyles, are such as to support the
sexual identification.

The second individual (Ost. Coll. 3248) was about
seventeen years of age, and is represented by various skel-
etal parts including a small, light, and essentially female
skull (Plate XXVIII) that exhibits an extreme degree of
Aymara deformation. A fragment of the pelvis, that for-
tunately has been saved, affords further evidence of the
female sex. The skull of this Indian girl furnishes an
excellent example of the type of deformation practiced by
the ancient inhabitants of the Eastern Cordillera and of
the Bolivian plateau. It differs fundamentally from the
"fronto-occipital flattening" of the coastal region, and
seems to have been produced by bandaging the heads of in-
fants tightly across the forehead, over the ears and under
the occiput, the bandage being perhaps held in position by
a sort of throat-latch. Cranial growth within the circum-
scribed area was greatly retarded, though not entirely
checked, with the result that the girth of an adult skull,
measured along the lines of constriction, may not exceed a
similar measurement taken from an undeformed five-year old
child of the same race. Compensatory growth could, of course,
take place only in an upward and backward direction. With
such favor was this style of cranial deformation regarded
by the Peruvian highlanders, if we may believe the older

writers, that the young woman, whose elongated skull was
found in this grave, was probably considered most attractive
by the Machu Picchuans. The profile of her skull should be
contrasted with that of the equally bizarre skull, showing
extreme deformation of the coastal type (Plate XXV, figures
4, 5 and 6), that was recovered from Cave 72. The two
skulls represent the most dissimilar ideals of beauty
imaginable. It is known that the Spanish Conquerors for-
bade the practice of cranial deformation; but with what im-
mediate success has not yet been learned. It would there-
fore be very wrong to assume that every deformed skull
dates from before the Conquest; but, on the other hand,
extreme voluntary cranial deformity, either of the coastal
or the Aymara type, furnishes satisfactory evidence that
the person whose head was thus distorted, was reared in a
part of the country essentially free and independent from
Spanish rule -- in other words, in a district where pre-
Columbian culture prevailed. By all accounts, the functions
of the brain were not seriously impaired by these deforma-
tions, which are supposed to have been inflicted, through
constant though not extremely severe pressure, at a very
early age, when bones are yielding and sutures patent.
Probably no part of the human skeleton can be artificially
deformed with less harmful results than the skull. In the
light of modern experience, it even seems possible that

distinct social advantages may have been enjoyed by the young
women possessing the most rigorously moulded heads. Minor
sufferings of childhood are usually forgotten in the hey-
day of youth; and "Il faut toujours souffrir pour être
belle." The modern feminine horror of being condemned for
life to an absolutely unchangeable fashion probably never
entered the minds of these aboriginal, though by no means
unsophisticated, American women. As for the men, some of
whom appear to have been subjected to like practices during
infancy, if their physical powers were likely to be greatly
impaired thereby, it is difficult to understand how the
practice came into vogue.

The third individual is represented by a few
badly decayed fragments of a small adult skeleton. Sex
and morphological type are alike unrecognizable. This
person seems to have been completely interred, for the
bones are all equally discolored by earth and affected by
decay, while the two other individuals appear to have been
placed in the contracted position on the floor of the cave.

Burial within the city does not appear to have
been an usual practise, at least during the later period
of occupation, from which alone it is probable that human
skeletal remains would be preserved. One stone-built
bottle-shaped grave was located, beneath the surface of
the ground, a few rods southeast of the Three-Window

Temple, in an area that Professor Bingham has named the Sacred Plaza. This grave may or may never have been occupied. There is nothing to show. When opened by our party, it contained no human remains. If formerly used for burial, the remains had long since been removed; but whether this was done by pious hands, or by ruthless treasure-hunters, we are unable to learn. Besides calling attention to the fact that the native treasure-hunter rarely burdens himself with bones, I may state here that an empty grave is not necessarily a plundered grave, as was most clearly proved to me, later in the season, when a closed and apparently finished stone chulpa, or tomb, at Choquequirau was carefully opened only to reveal its bottle-shaped interior bare as an empty purse -- and as disappointing.

Human remains were, however, found in two places near the Sacred Plaza, and in one place beneath the floor of an outlying building; and a report upon the skeletal material collected at Machu Picchu would be incomplete, did it fail to mention these localities.

A fragment of a small human femur was picked up on the surface of the ground outside and below the windows of the Three-Window Temple. Speculation as to how it got there among miscellaneous refuse would be useless.

While clearing away undergrowth and excavating all sorts of debris from an irregular plot of ground, a few rods

M. P. Coll. 60 Dish handle, crouched human figure
Small hammer stones (?)
Polishing Stones (?)
Small river pebbles.
Sherds.
Llama bones.

The occurrence of two bronze mirrors and of two bronze knives, not to mention part of a third, suggests the possibility of more than one interment having been made in the cave; but no proof of this can be had from the extremely meager human remains that were recovered.

While excavating in a building at the south end of the fifth terrace below the semi-circular tower, Mr. Erdis came upon a few badly decayed fragments of a human skull and long bones, evidently belonging to a small, old individual of unknown sex. The only article recorded as having been found with these bones was a square piece of thin green chloritic schist about 10 cm x 7.5 cm in size; and it is possible that this interment had been already disturbed by treasure-hunters.

NEW MAMMALS FROM MACHU PICCHU.

*Abrocoma oblativa*, sp. nov.

Plate XXXVIII, figures 1, 2, 3, 4, 5.

Skeletal material, referable to a new species of
*Abrocoma*, was obtained from several of the burial caves,
whole bodies of the little rodents, or portions of them,
having been provided, in accordance with the custom of the
Indians, to satisfy the supposed requirements of the dead.

Two species of _Abrocoma_ were described by Water-
house in 1837 (Proc. Zool. Soc., London. Part V, 1837,
page 30) from specimens collected in the mountains of the
Province of Aconagua, Chile, by Darwin, during the historic
voyage of the Beagle. Until the present time, the genus
has not, to my knowledge, been reported from Peru; and its
occurrence at Machu Picchu, about 1200 miles from the
locality of the type specimens, collected by Darwin, adds
greatly to the interest the skeletal material, without the
pelt, would otherwise possess, and renders a careful com-
parison with the Chilean species desirable.

The specific definitions of _Abrocoma bennettii_
and _A. cuvieri_ in Waterhouse's Natural History of the
Mammalia include important measurements of the type
skulls, and are therefore preferable to his original

definitions. Several figures of the skull of *A. cuvieri* are
given in the Zoology of the Beagle, Part II; and the type
skull of *A. bennettii* is figures in the Natural History of
the Mammalia, from the lower or palatal view only. For-
tunately the Osteological Collection of the Peabody Museum
of Yale University affords for comparison an excellent
skull from Chile, whose original identification as *A. ben-
nettii* was facilitated through the skull being accompanied
by the pelt, so that reference could be had both to cranial
and external characters.

The measurements of the type skulls were given by
Waterhouse in inches and lines. I have taken the liberty
of translating these into the metric system, in order to
arrange them more conveniently, in parallel columns with
similar measurements of the three skulls of this genus that
are now in the Peabody Museum of Yale University, namely the
skull of _A. bennettii_ (Ost. Coll. 1240) and the two skulls
(Ost. Coll. 3318 and 3320) from Machu Picchu. No. 3320 is
designated as the type of the new species, for which I pro-
pose the name _Abrocoma oblativa_ in reference to the pious
use, by the Indians, of the flesh of these little animals.

From the accompanying table it is apparent that
the skull of the new species differs from those of
*A. ben-
nettii* and *A. cuvieri* not only in its much greater size,
but also in certain important proportions of the cranial
and facial bones. Comparison of the length-breadth in-
dices shows the Peruvian skull to be much narrower in form
than the others, with reference to the bizygomatic diameter.
At the same time the width of the interorbital space is
both actually and relatively greater than in *A. bennettii*.
The upper tooth rows in the new species are nearly parallel,
while in the other species, especially in *A. bennettii*, the
space between the anterior molars is much less than that
between the posterior molars. The basi-occipital, basi-
sphenoidal and pre-sphenoidal elements are relatively much
stouter than in *A. bennettii*. With the corresponding parts
of *A. cuvieri* they cannot be compared, as the type skull of
the latter species, figured in the Zoology of the Beagle,
is defective. The "single, tolerably large opening opposite
the second molar," thought by Waterhouse to be characteristic
of the genus, is here represented by a pair of small foramina
placed further forward, opposite to the contact between the
first and second molars. The width of the nasal bones an-
teriorly is greater in the new species; and the nasal portion
of the skull less compressed.

practically no hunting and trapping carried on in the region.
In fact general conditions are so favorable to the preserva-
tion of the smaller herbivorous mammals, that it may still be
possible to secure recent specimens both of this new rodent
and also of the new species next described.

<u>Agouti thomasi</u>, sp. nov.

Plate XXXIX, figures 1, 2, 3.

Bones of food animals, obtained from burial caves
and middens, include skeletal parts of eight rodents of the
genus _Agouti_. Some of the material is very fragmentary, as
might be expected considering the manner in which it was
preserved; and therefore, although it is quite possible
that all these animals represent the same species, I can-
not prove that to be the fact. It is evident, however,
that the largest and best specimen of the series, a fairly
well preserved adult (aged) skull, found in a small kitchen-
midden near the eastern limit of the city, is distinct from
all species that have yet been described under the genus
*Agouti*. I have therefore selected this skull (Ost. Coll.
3327) as the type of a new species, which I have the honor
to name *Agouti thomasi* after Mr. Oldfield Thomas of the
British Museum (Natural History).

7

I have no material of M. J. Stolzmann's *A. tac-
zanowskii* for comparison, but his excellent description
and illustrations, and the comprehensive table of measure-
ments which he compiled, show at once that the new type
skull does not belong to the species he described from
Equador (Proc. Zool. Soc., London, 1885, p. 161). The
new skull differs from *A. taczanowskii* principally in
the following details:

It is longer and has a much smaller zygomatic
breadth, while the greatest height of the zygoma is also
very much less. The flare of splay of the posterior
wings of the zygomata in the new skull is more pro-
nounced than in *A. taczanowskii*; and the maximum zygo-
matic breadth is conspicuously greater than the zygomatic
breadth taken opposite the second molar, while in *A. tac-
zanowskii* the difference between these two diameters is
insignificant, the latter species approaching, in this
respect, *A. paca*. I may add that a skull of *A. paca*
(Ost. Coll. 120) is actually wider opposite the second
molar than at the posterior angles of the zygomata --
a peculiarity of form that is correlated with the im-
mense size of the lateral oral capsules.

The surface is quite smooth, even the lower bor-
ders of the zygomata being entirely free from the corruga-

tions so characteristic of *A. paca* and *A. taczanowskii*.
This total lack of superficial corrugation on the new
type skull, which has somewhat thin inferior zygomatic
margins, leads me to suppose that it is female; for a
younger and slightly smaller skull (Ost. Coll. 3316),
Plate XXXVIII, figures 6, 7, from Cave 13, and also a
fragment of a still larger skull, from Cave 9, exhibit
moderately roughened surfaces near the lower borders of
the zygomata, and the inferior edges of these arches are
stouter than in the type skull. I can see no reason why
this last difference should not have here the same sexual
significance that it has in the case of human crania. As
no lower jaw was found with the type skull, an imperfect
mandible from Cave 99, presumably of the same species, is
shown in Plate XXXVIII, figure 8.

Mr. Oldfield Thomas' *Agouti sierrae* from Venezuela is the species that the new skull resembles most closely, as will appear from the accompanying table, in which are arranged, in parallel columns, measurements of *A. sierrae* given by him in The Annals and Magazine of Natural History, 1905, Vol. XV, 7th Ser., p. 589, and those of the new Peruvian species.

<table><thead><tr><th colspan="4">Measurements of Skulls in millimeters</th></tr><tr><th></th><th>A. sierrae</th><th></th><th>A. thomasi<br>(type)</th></tr></thead><tbody><tr><td>Greatest length</td><td>123.</td><td></td><td>129.</td></tr><tr><td>Basilar "</td><td>99.</td><td></td><td>116.</td></tr><tr><td>Zygomatic breadth</td><td>82.</td><td></td><td>81.</td></tr><tr><td>Nasals</td><td>41.x 22.5</td><td>47.x 24.</td><td></td></tr><tr><td>Interorbital breadth</td><td>35.</td><td></td><td>32.</td></tr><tr><td>Tip to tip of postorbital processes</td><td>49.</td><td></td><td>42.</td></tr><tr><td>Least breadth above auditory meatus</td><td>37.5</td><td></td><td>38.</td></tr><tr><td>Greatest posterior breadth</td><td>47.5</td><td></td><td>48.</td></tr><tr><td>Occipital height from basion</td><td>28.7</td><td></td><td>29.</td></tr><tr><td>Length of broadened surface of zygoma</td><td>64.</td><td></td><td>68.</td></tr><tr><td>Greatest height of zygoma</td><td>36.</td><td></td><td>37.</td></tr><tr><td>Zygomatic concavity in horizontal plane</td><td>34.x 18.</td><td>34.x 22.</td><td></td></tr><tr><td>Diastema</td><td>38.</td><td></td><td>42.</td></tr><tr><td>Postpalatal length</td><td>38.</td><td></td><td>40.</td></tr><tr><td>Length of upper tooth row (crowns)</td><td>28.</td><td>Approx. 27.</td><td></td></tr><tr><td>Antero-posterior diameter of bullae</td><td>14.</td><td></td><td>15.5</td></tr></tbody></table>

The great distance -- over a thousand miles -- separating the known habitat of *A. sierrae* from the locality where this new species was found, taken into consideration with the occurrence midway between of a form very different from either, naturally adds courage to my conviction that the Paca inhabiting the Peruvian Andes, centuries ago, was distinct from the species of *Agouti* hitherto described.

his fellows. If the Spaniards had set a like example as regards other vices, they would have been apostolic preachers of the gospel."

I have quoted freely from these two most conscientious writers, who were witnesses of many of the acts they described, in order to establish, at least a strong probability that the inhabitants of the magnificent city of Machu Picchu, following the practices of their race and times, visited the bodies of their dead at certain seasons and accorded them essentially the same formal honors as have been described in the scenes at Cuzco. Indeed as Machu Picchu is one of the few "chief places" that seem never to have escaped invasion by armed bands of the conquerors, it is altogether credible that some of the ancient mortuary customs should have persisted there long after their abandonment by those communities that fell completely under the Spanish power.

Now I come to a part of my argument that may not seem entirely dignified, and yet is advanced for a serious purpose. It must be apparent from the preceding quotations that great quantities of intoxicating liquor were consumed by the Indians at their religious feasts; and although neither Garcilaso nor Molina refer in detail to any disorderly conduct on the part of the people, no one who has witnessed the modern descendants of these same Indians during the celebra-

"Lorsqu'on souhaite la secheresse, on retire d'un
tombeau un crane et on le fiche sur une perche. Cette
curieuse coutume pourrait expliquer pourquoi Ten Kate a
trouvé chez les Colchaquis de l'Argentine tant de tombeaux
ou le crane faisait défaut. Si on veut rendre quelqu'un
malade, on place quelquesuns de ses cheveux ou un objectif lui
appartenant, dans un vieux tombeau."

The last sentence of the foregoing quotation also
deserves serious consideration; for in any region where
attempts were made to cause persons to fall ill, by placing
objects belonging to them in ancient graves, the human
remains and other objects, originally placed therein, would
be given a comparatively recent aspect that might, in some
instances, prove extremely deceptive, and even cause a pre-
Columbian grave to be wrongly assigned to the post-
Columbian period.

While in the Urubamba Valley I saw nothing that would
lead one to suppose that the modern Indians of that region
remove skulls from ancient graves in order to hasten the close
of the rainy season; and yet I did observe a wayside shrine
near Huadquina, and about five hours journey from Machu Picchu,
where two well bleached, and, to all appearances, old skulls
were placed on the pedestal of the crucifix, one at each side,
as shown in the accompanying text-figure. I was unable to

ascertain what the presence of the skulls actually signified.
Inquiries brought little response. Vestiges of ancient an-
cestor-worship, which are still to be noted among the modern
Indians, are most likely to be concerned in the true explana-
tion than are the teachings of the Church of Rome. I can
only state with certainty that a heavy downpour of rain, that
made it impossible to photograph the shrine, left serious
doubts regarding the magic power of the skulls to produce
and maintain a drought.

Taking into account all the human skeletal material
found in caves and graves at Machu Picchu, the total number
of individuals represented amounts to about one hundred and
sixty four. This assemblage may be conveniently regarded as
composed of the following groups:

<table><tr><td>Adult males</td><td>23</td></tr><tr><td>Adult females</td><td>103</td></tr><tr><td>Young males</td><td>4</td></tr><tr><td>Young females</td><td>7</td></tr><tr><td>Adults of unknown sex</td><td>17</td></tr><tr><td>Young persons of unknown sex</td><td>7</td></tr><tr><td>Infants</td><td>5</td></tr></table>

The skulls of determinable type and sex, while,
of course, less in number than this total of individuals,
offer the only means of getting at certain important facts
of the census; and as the errors that result from basing
calculations, in part, on skulls instead of on individual
skeletons, are trifling, there can be no serious objection
to making use of this convenient method of computation.

Of the adult males appear to be of
the coastal type, and of the highland type.
None of the male skulls of the coastal type exhibit
voluntary deformation; and only of the
skulls of men of highland ancestry show either typical or
variant Aymara deformation. Among the adult females those
of highland ancestry appear to have been more numerous, as
might be expected in view of the city's geographic situation,
skulls of this type having been found as
against of the coastal type. The adult
female skulls include showing Aymara de-
formation and showing the fronto-occipital,
or coastal, deformation.

By these figures the fact is at once brought out
that the female interments far outnumber the male interments;
and this discrepancy in the balance of the sexes is so
striking as to call for some explanation.

I am strongly inclined to the opinion that during
the late pre-Columbian and early post-Columbian periods of
occupation, the Inca Empire maintained, at Machu Picchu, one
of those convent-like establishments, known as acolahuasi, and
that the female skeletons, found in such predominance, are
largely the remains of Virgins of the Sun and priestesses
engaged in the service of the temple. Another hypothesis is

Professor Hiram Bingham,
Yale University.

Dear Mr. Bingham: -

The results of my examination of the
osteological material from the vicinity of Cuzco, Peru,
submitted to me for identification on December 26, 1911,
are given in the following brief report:

Under the List of Genera and Species
are enumerated the specimens that are sufficiently char-
acteristic for identification. Each bone is numbered
in this List, so that by turning to the corresponding
numbers in the Description of Material, further informa-
tion may be found regarding the more important specimens.

Thanking you for the privilege of
making the first examination of your interesting and
valuable collection,

I remain,
Faithfully yours,

Yale University Museum,
March 4, 1912.

## - 2 -

Description of Material.

Homo sapiens.

The human remains comprise the following specimens:

1. An irregular fragment of a right parietal bone, measuring about 7.5 cm along the sagittal suture and 2.0 cm along the coronal suture. Posteriorly the fragment is about 6.0 cm wide. The sutures are moderately tortuous, and the bone, which is of fair but not remarkable thickness, is presumably from an adult skull. The outer and inner tables are firm and well preserved, the latter showing the Pacchionian depressions and the characteristic grooves made by the branches of the middle meningeal artery. It is, of course, useless to attempt to describe the particular type of cranium represented by such a small fragment further than to state that the sagittal and transverse curvatures are moderate rather than extreme, and present no indications whatever of pathological or artificial deformation. The fragment is too short to show the presence or absence of an interparietal bone, the so-called os Incae.

2. An incomplete right 5th thoracic rib.

3. The greater part of a right 9th thoracic rib of fairly robust character, though not of especially large size.

- 3 -

4. An incomplete right os innominatum in four fragments. Practically all that is preserved is the ilium, the pubis being lost, as well as nearly the whole of the ischium, with the exception of a little of the ischiatic portion of the acetabulum. The imperfect condition of this bone and the absence of the sacrum render it impossible to measure all the pelvic diameters and to calculate the conventional pelvic indices; but an approximate idea of the size of the pelvis may be obtained from the following linear measurements:

From the posterior superior spine to the anterior superior spine, 16.0 cm.

From the summit of the iliac crest to the nearest point on the acetabular rim, 12.0 cm.

This bone is of massive form throughout, with well-developed rugosities. That it is from a male skeleton is further shown by the absence of a prae-auricular sulcus. Possibly this pelvis belonged to the same individual as the bone next described.

5. A nearly complete right femur. The contours of the ends of this bone are massive in proportion to its length, and the shaft is also well developed, though not especially large. It is necessary to record here only a few of the measurements that have been taken of this femur, in order to indicate its essential form.

- 4 -

<table>
  <tbody>
    <tr>
      <td>(1) Physiological length, or length in oblique position,</td>
      <td>42.4 cm</td>
    </tr>
    <tr>
      <td>(2) Trochanteric length,</td>
      <td>41.1 cm</td>
    </tr>
    <tr>
      <td>(3) Transverse diameter at a point 3 cm distal to the most prominent part of the lesser trochanter,</td>
      <td>3.6 cm</td>
    </tr>
    <tr>
      <td>(4) Antero-posterior diameter at same point,</td>
      <td>2.6 cm</td>
    </tr>
    <tr>
      <td>(5) Index of superior platymeria = (4) x 100 / (3),</td>
      <td>72.2</td>
    </tr>
    <tr>
      <td colspan="2">(This is a ratio, not a metric length.)</td>
    </tr>
    <tr>
      <td>(6) Transverse diameter at middle of shaft,</td>
      <td>2.7 cm</td>
    </tr>
    <tr>
      <td>(7) Antero-posterior diameter at middle of shaft,</td>
      <td>2.9 cm</td>
    </tr>
    <tr>
      <td>(8) Proximal breadth, taken from the free surface of the head across the great trochanter,</td>
      <td>9.6 cm</td>
    </tr>
    <tr>
      <td>(9) Vertical diameter of head,</td>
      <td>4.8 cm</td>
    </tr>
    <tr>
      <td>(10) Transverse diameter of head,</td>
      <td>4.7 cm</td>
    </tr>
    <tr>
      <td>(11) Collo-diaphysial angle, approximately,</td>
      <td>119°</td>
    </tr>
    <tr>
      <td>(12) Maximum transverse diameter of distal epiphysis,</td>
      <td>8.8 cm</td>
    </tr>
  </tbody>
</table>

The distal end of the femur is also characterized by a wide inter-condylar notch. No comparison can be made of the antero-posterior lengths of the condyles, as the median condyle is imperfect. The curvature of the shaft is slight. The linea aspera is prominent, as indicated by the pilastric index of 107.7, obtained from the diameters at the middle of the shaft. The gluteal line is well developed, but there is no actual third trochanter. The anterior inter-trochanteric line is indistinctly marked, and the anterior surface of the shaft immediately below this line is slightly concave, while the external surface of the upper part of the shaft is bowed a little outward. The resulting platymeria, or femoral flattening, does not,

- 5. -

on the whole, afford any satisfactory racial indications.
Manouvrier attributes platymeria to excessive use of certain muscles of the leg in climbing steep slopes - a theory that is not ill-suited to the present case, the topography and geology of the region where the bone was found also favoring the supposition that we have to do with a hill-man or mountaineer.

The form and size of this femur, as recorded in the foregoing measurements and description, fall within the range of femoral variation in normal adult male Peruvians of the later Inca period. I have already stated that this femur may possibly have belonged to the same individual as the pelvic fragments, bone 4. The two bones are of compatible size and form, and would represent a thickset and muscular man about 5. feet and 4 inches (1.625 m) in height.

It is clear that no proof of great antiquity can be drawn from the characters of the human skeletal parts submitted to me, agreeing, as they do, in all essential respects with the bones of a recent people. Until additional skeletal material is obtained, showing characters more primitive than those already noted, the burden of proof of great antiquity must rest on geological and paleontological evidence.

6. An imperfect left femur of considerably smaller size than that designated as number 5. While of the same general type as the larger bone, it is a little less robust in its proportions. The proximal end is poorly preserved and the distal end is missing. A very crude calculation gives a physiological length of 38.0 cm (15 inches).

- 6 -

7. The proximal portion of a right femur of approximately the same size and form as number 6.

8. Several fragments from the shaft of a left femur of about the same size as number 6.

Canis sp.

9. The shaft of a left tibia. Although this bone is much battered, and both ends have been broken off, it is clearly from the skeleton of a wolf or wolf-like dog. It closely resembles the tibia of a small Gray Wolf, *Canis occidentalis*.

In this connection it is interesting to note that three distinct varieties or breeds of domestic dogs are known to have existed in Peru during the later Inca period. Dr. Nehring has described these as follows: (1) A small-sized breed of the bulldog or pugdog type, characterized by a short snout, with undershot jaw; (2) a small house-dog like a Dachshund, with slender snout; and (3) a larger slender-limbed dog, with wolf-like skull, originally described by Tschudi under the name *Canis ingae pecuarius*. According to Dr. Nehring, the two smaller breeds were derived from the larger wolf-like variety, which, he states, was itself derived from the American wolf. The presence of a tibia of a large wolf-like dog among the bones collected at Cuzco, while it offers no proof of great antiquity, certainly does not in any way render such a view untenable.

- 7 -

Bos sp.

10. The metatarsus, or "cannon bone," of the left hind leg. The length of the bone without the distal epiphysis, which was not preserved, is 19.0cm, or 7 1/2 inches. Subsequent to the loss of the epiphysis, and prior to deposition in the locality where found, the bone has been eroded to such an extent that the sharp edges of its modelling are destroyed.

11. A small fragment of a right radius.

12. A fragment of a 1st right thoracic rib.

Realizing the importance of determining whether these bovine remains belong to a feral or to a domestic race, I have endeavored to obtain all possible evidence on this difficult question. As these fragmentary bones (10, 11, and 12) are among the least characteristic parts of the skeleton, their exact specific identification is beset with almost insuperable difficulties. While it is a simple matter to distinguish the hind cannon bone of a slender-limbed dairy cow from that of an adult Bison, a careful study of a large series of specimens shows that metatarsi of an intermediate type exist, which bafe specific identification unless accompanied by other more characteristic skeletal parts. This is true of the cannon bone designated as bone 10. The fact that the epiphysis is missing warrants the supposition that the bone is from a young animal, and accordingly had not attained its full growth. The fragment of a radius (bone 11) is too meager to be of any assistance in the present search for specific characters. The

- 8 -

bovine specimen that is of greatest interest is the fragment of
a 1st rib, designated as bone 12. I have examined the 1st ribs
of the following Bison, *Bos americanus*: An adult male and an adult
female in the Yale University Museum; an adult male and a young
female in the U. S. National Museum; and an adult male and a
young female in the Museum of the Brooklyn Institute of Arts and
Sciences. In all these, the origin of the external intercostal
muscle is marked anteriorly by a well-defined ridge on the lower
near its posterior border,
third of the bone, and the external surface of the rib anterior
to this ridge is somewhat flat and approximately parallel to the
plane of the internal surface. As might be expected, the 1st
ribs of the females and of the younger animals of both sexes have
the ridge less strongly marked than is the case with the older
males. The 1st rib of the extinct Bison, *Bos occidentalis*, has
essentially the same typical form. I have also examined the 1st
ribs of a number of domestic cattle, the *Bos taurus* of zoologists,
including two dairy cows, three well-grown beef animals of uncer-
tain breed, and two fully adult Long-horned Texas Steers. In all
these examples of *Bos taurus*, the ridge that bounds the origin of
the external intercostal muscle is placed much further forward on
the lower end of the bone, and no such extensive flattened surface
appears in front of this ridge as was noted in the examples of *Bos
americanus*.

In respect to these apparently differential characters, the
fragmentary bovine rib from Cuzco, designated as bone 12, is of
the form that appears to be characteristic of the Bisons, and
differs from the form seen in all the domestic cattle that I have

[Eaton, G.F. - 1912]

In support of the claim that the scope of the
report entitled "Indian Graves at Machu Picchu" is just
and reasonable, the author submits the following:

(1) That a report on the dry bones alone, without
reference to other articles collected with them, and with-
out a statement of the author's views upon the special and
general aspect of the graves, would be inadequate and would
fail to do credit to the author and his colleagues of the
Peruvian Expedition of 1912.

(2) That many of the ethnological references in the
report are to objects that have already been figured and
described in widely circulated publications by Professor
Bingham; and that, according to custom, the objects may now
be fairly discussed by anyone interested. The author has
therefore felt free to state, in polite terms, his own views,
even when they have not coincided with those held by the
Director of the Expedition.

(3) That in many instances the author has been able,
through his close study of artifacts associated with human
remains, to add something to the interest in the personality
of the individuals whose bones were collected.

(4) That the determination of the age of the skeletal
material, or of the culture period to which it pertains,
rests largely on such a study of the garniture of the graves
as the author has laid before the reader.

- 2 -

(5) That Professor Bingham's original understanding of the scope of the report was the same as that of the author, is shown by:

(a) Professor Bingham's spoken words of approval, Feb. 11, 1915, of the author's proposal to illustrate in his report the entire contents of two or three graves as well as an indefinite number of pieces, from other graves, that in the author's judgment might seem of interest in connection with the study of the graves and bones, this being the first occasion when Professor Bingham and the author entered into any discussion of the scope of the report.

(b) Professor Bingham's gift to the author of the accompanying typewritten treatise on the nomenclature of potforms, in order that the author might use in his references to pottery the same terms adopted by Professor Bingham.

(c) Professor Bingham's cablegram from Peru with instructions to the author where to search for the modern bone bodkin presented by Morales, this message being in reply to the author's enquiry as to the whereabouts of the specimen which he wished to illustrate.

(6) That on Sept. 21, 1915 -- the date of the first meeting of Professor Bingham and the author after the former's return from Peru, the author called at Professor Bingham's office with all the illustrations for the report,

- 3 -

offered them to Professor Bingham's inspection, and received
not only high commendation for the quality of the illustra-
tions but also the request, which was gladly granted, to
permit Professor Bingham, later on, to use some of the same
excellent illustrations of artifacts in his own projected
work on Machu Picchu.

(7) That on this same occasion the author obtained
Professor Bingham's consent to the reference in a foot-
note of the report to an urn-burial discovered by the
Peruvian Expedition of 1914-1915 which the author desired
to comment on in connection with the urn-burial from
Cave 79.

(8) That further justification of the scope of the
report is to be had from the accompanying typewritten
sheet, received from Professor Bingham's own hand, Nov.
18, 1915, wherein the title "Indian Graves at Machu Picchu"
is adopted by Professor Bingham without criticism, and
wherein, Bingham *loquente*, the author's thanks are express-
ed for the kind interest that "made possible the archaelog-
ical work."

The author confidently hopes that the same broad
view which prompted these words of acknowledgment will also
approve of the scope of the report.

Vertebrate Fossils from Ayusbamba, Peru.

While engaged upon the field-work of the Yale Peruvian Expedition of 1912, I had the pleasure of accompanying Dr. Albert Giesecke, President of the University of Cuzco, on a hasty visit to a locality near Ayusbamba, among the mountains about thirty miles south of Cuzco, where he had previously obtained some fragmentary vertebrate fossils. On this occasion a few hours only could be spent in the field; but as it seemed probable that by going over the ground carefully, further material might be secured, Professor Bingham, the Director of the Expedition, gave his consent to my making another visit to the locality, this time in company with Professor Gregory, the Geologist, and Mr. Heald, Assistant Topographer of the Expedition. Although other important work caused the postponement of this trip until the middle of November when the rainy season, unfavorable to fossil-hunting in the mountains, had set in, we were able to obtain material of considerable value during the three days our party was in the field.

To Sr. Emeterio Calvo, the master of the delightful Hacienda Ayusbamba, I owe my sincere thanks, not only for permission to collect upon his land, but also for the generous hospitality extended to our party.

The fossils that form the subject of these notes occurred at an altitude of about 12400 feet, in gravel and clay beds and in surface-wash along the southern margin of a small lake, the original contours of which are partially indicated in the map (Plate 1) accompanying the preceding article by Professor Gregory.

An excellent view, looking southerly across the fossil grounds, appears as figure 6 of Professor Gregory's report. Very nearly the reverse view (N. 50° E. Mag.) taken from the south rim of the basin, is shown in text-figure 1 of the present article. After taking this photograph the camera was turned a little to the right (N. 30. E.) and the view shown in text-figure 2 was taken. These two views together cover practically all of the fossil grounds. Almost at the exact center of Professor Gregory's.

Mastodon's report.

2.

Figure 6, a mastodon's blade bone was found. The nearer view of this spot (text-figure 3) is equally characteristic of several other places where fossils occurred. In this photograph, taken while waiting for the protective jacket of burlap and plaster to dry, appears one of our faithful arrieros whose interest in collecting fossils made him very helpful.

With few exceptions fractured and dissociated material only was found. This indicates clearly that, in most cases, the bones of animals, perishing near the borders of this ancient lake, were widely scattered before being finally covered by alluvium from the neighboring heights. It is possible that some of this material may have been originally embedded at a higher level and in a slightly older formation. I see no reason, however, to question the contemporaneity of the extinct species of animals represented in this collection.

No vertebrate fossils had been previously described from this part of the Cordillera. Therefore every recognizable specimen, that might add to our knowledge of the extinct Fauna of the region, was collected, without regard to its perfection and availability for exhibition. Nearly all of this material has now been identified, and it is found that specimens can be referred to five mammalian families, the Camilidae, Cervidae, Equidae, Elephantidae, and Mylodontidae. No fossil remains of Rodents and Carnivors were observed. The material may be assigned to the following genera:

### Lama sp.

The fifth lumbar vertebra and portions of the right ilium and ischium. The specimens compare closely with the corresponding skeletal parts of a medium-sized animal of the recent species, Lama huanachus. It is, of course, impossible to assign the present specimens definitely to any one of the several species of this genus that have been described from the Pliocene and Pleistocene of Argentina and Brazil.

### Odocoileus brachyceros

The material from Ayusbamba referable to this genus and species

4.

largest bones is not more than three-quarters as great as that of the medium-sized example of *Mammut americanum*, whose mounted skeleton is exhibited in the Peabody Museum of Yale University. The height of this animal, taken at the shoulder, is about 8 feet and 3 inches.

Of the six South American species of *Mastodon* described by Ameghino (Mamiferos Fosiles de la Republica Argentina) the two most generally recognized are *Mandium*, Cuv. and *M. humboldti*, Cuv. According to Pompeckj, there are two other valid species, namely *M. bolivianus* Philippi and *M. chilensis* Philippi (emend. Pompeckj). While Pompeckj does not adopt Cope's separation of *Dibelodon* and *Tetrabelodon* from *Mastodon*, it should be understood that both *M. bolivianus* and *M. chilensis* as well as *M. andium* and *M. humboldti* belong to the Dibelodont division of the original genus.

Most of the mastodon bones found at Ayusbamba present no characters that can be utilized in the identification of the species. As might be expected it is best to rely principally upon the form and structure of the teeth. Two specimens have therefore been selected to illustrate the type of dentition. From the piece of a right (upper) tusk shown in Plate I, figures 1 and 2, the following measurements have been taken:

<table><tr><td>Circumference of proximal end</td><td>354 mm</td></tr><tr><td>Breadth of enamel band</td><td>90</td></tr><tr><td>Maximum diameter at proximal end</td><td>117</td></tr><tr><td>Minimum diameter at proximal end</td><td>104</td></tr><tr><td>Angle of torsion</td><td>12°</td></tr></table>

The last of these measurements requires a few words of explanation. A mastodon's tusk upon which the enamel band, or other line of *Mastodon Resti* aus dem inter-andinen Hochland von Bolivia. Paleontographica, vol. 52, 1905

5

growth, describes a helix, presents a certain analogy to a screw; and the torsion of such a tusk may properly be regarded as a pitch angle. The angle of torsion, used here, is defined as the angle that a tangent to the spiral enamel band, at any point, makes with the adjacent axial line of the tusk. This measurement is easily taken. It has the further advantage of being independent of length, diameter and circumference; and may prove to be of considerable taxonomic value. The mere statement that an enamel band makes one revolution, or one-half revolution, about the axis, without any record of length and diameter, does not adequately describe the torsion.

The form of the tusk of M. bolivianus is described by Pompeckj* as follows: "Der Querschnitt is vollkommen elliptisch; die Durchmesser sind an der hinteren Bruchfläche 8.9:6.2 cm, an der vordere 6.2:4.7 cm. Das z.T abgefallene Schmelzband hat vorne eine Breite von 5.65 cm." In another place† he compares this tusk with that of M. andium: "Die schlanken, sehr wenig gekrümmten, in Schraubenspirale von ungefähr 1/2 Windung gedrehten Stosszähne haben bei Mastodon bolivianus stark komprimierten elliptischen Querschnitt, nicht den kreisrunden der Zähne von Mastodon Andium."

That the enamel band is very broad in M. bolivianus is evident from Pompeckj's measurements of the anterior portion of a tusk and also from his illustration of a basal fragment‡‡, where the enamel appears to cover one-third of the circumference. The band is a trifle narrower in the fragment of tusk from Ayusbamba, which differs also from M. bolivianus in the ratio of the maximum

* op. cit. p.38

†op. cit. p.44

‡‡op. cit. Taf. IV fig.56.

6

and minimum diameters. To comply with the diametric ratio (8.9:6.2) obtained from *M. bolivianus*, the Ayusbamba specimen having a maximum diameter of 117 mm, would require a minimum diameter of only 82 mm, instead of 104 mm, as recorded. Yet its section, as shown in figure 5, is still very far from circular, and cannot be described by the same terms that Pompeckj uses in reference to the tusks of *M. andium*. The tusk of the latter species, figured by Ameghino*, greatly exceeds the Ayusbamba specimen in diameter, and possesses an enamel band relatively much narrower. Its curvature and the angle of torsion of the enamel band are approximately the same as those of the Ayusbamba specimen. The torsion of the tusk of *M. bolivianus* is not recorded in such a way as to be available for comparison.

Views of the grinding and labial surfaces of an unworn molar from Ayusbamba are shown in Plate I, figures 2 and 3. This tooth, imperfect anteriorly, is presumably an upper molar of the left side. Large accessory tubercles rest like butresses against the inner columns, but the tubercles that flank the outer columns, and those that lie in the depths of the outer valleys, are so small as to be almost hidden beneath the thin layer of cement. As a result of this arrangement, the tooth would be characterized, during early stages of wear, by the presence of trefoils on the inner columns only, while the outer valleys would remain open. Although this tooth agrees, in the foregoing characters, with the specific definitions of *M. andium* given by Lydekker† and by Ameghino in his work already cited, the correspondence fails entirely when the contours of the outer columns are considered. Lydekker states that "The form of the dentine-

*Mam. Fos. de la Repub. Argent. p.640.

†Cat. Foss. Mam. Brit. Mus. 1886.

7.

#59

disk on the columns which do not bear trefoils in pear-shaped, with the apex directed toward the adjacent column." The outer columns of the Ayusbamba molar are stouter where they approach the median cleft than at their labial borders, and would not, at any stage of wear, assume a pear-shaped outline. In view of this essential difference, I do not think that the *Ayusbamba* molar should be referred to *M. andium*. It compares much more closely with the lower molar of *M. bolivianus* figured by Pompeckj.*

The small accessory tubercles, that flank the inner columns and line the inner valleys of this tooth find their counterparts half-concealed beneath the cement layer of the *Ayusbamba* molar. The transverse measurements of the tooth of *M. bolivianus*, taken at the base of the crown, viz. for the 1st cross cusp 7.4 cm, for the 2nd 7.75 cm, for the 3rd 8.0 cm, for the 4th 7.8, for the 5th 7.4 cm, correspond very nearly with the following transverse measurements taken in the same way from the *Ayusbamba* molar: for the 1st cross cusp 7.3 cm, for the 2nd 7.4 cm, for the 3rd 7.2 cm. Taking into consideration the characters of this molar tooth and also those of the fragment of tusk, previously described, I am confident that both of these specimens should be referred to *Mastodon bolivianus* Phil. (emend Pompeckj), or *Dibelodon bolivianus*, as it is best to use the generic name proposed by Cope.

It is not surprising that remains of this species should be found at Ayusbamba; for Ulloma, where the type material of *D. bolivianus* was obtained is less than 350 miles distant, being situated at an altitude of about 3800 meters, in the high Bolivian table-land south of Lake Titicaca. There seems to be no reason

*op. cit. Taf.III, fig.la.*

8

to doubt that the same climatic conditions prevailed in these
two localities during the early Pleistocene.

Mylodon sp.

The Gravigrade Edentates hold such an important place in the
Pleistocene fauna of South America, and have been so closely
associated, in their distribution, with the *Elephantidae* and
*Equidae*, that one might expect to find the group represented in
the collection from Ayusbamba. Vertebrae, pieces of the ribs,
including an ossified sternal section with its characteristic
double articulation, and an ungual phalanx, from this locality,
should be referred provisionally to the genus *Mylodon*, so
closely do they resemble the corresponding parts of the mounted
skeletons of *M. robustus* and *M. myloides* in the American Museum
of Natural History. I have no means of determining the species.
In this connection may be mentioned a humerus of *Mylodon* that
was found, not at Ayusbamba, but within two miles of Cuzco,
where the road to Ayusbamba ascends from the Huancaro Valley.
The location of the bone beneath well-defined beds of fine and
coarse alluvium, about 28 feet in thickness, is marked in text -
figure 4 by the point of an arrow. This humerus, shown in Plate
I, figures 5 and 6, differs from the humeri of *M. robustus* and
*M. myloides* at the American Museum in not having so prominent a
deltoidal tract. The outer tuberosity is also smaller, and the
posterior outline, immediately below the head, is more deeply
concave. These differences, while slight, are sufficient to
indicate that some species of *Mylodon* other than *M. robustus* and
*M. myloides* occurred in this part of the Cordillera. Potsherds
and bones of llamas were observed at a depth of 2 1/2 feet in the

9

#59

surface stratum at the top of the bank where this humerus was found; but no objects were seen in the lower strata that could, in any way, associate the *Mylodon* bone with the period of human in-habitation.

## *Parahipparion.*

Equine remains collected at Ayusbamba include several teeth, a fragmentary skull and a portion of the distal end of a femur. The teeth were all surface specimens, and there was nothing about the manner of their occurrence to prove that any of them belonged to the same individual as the skull. Two of them, however, may be from one individual, not necessarily because they were picked up within a few rods of each other, but because they show equiva-lent structure, size and stage of wear. These two teeth, first and second functional lower cheek teeth (p 2 and p 3) are accord-ingly represented together in text-figure 5. Owing to their imperfection exact measurements cannot be taken; but the length and width of their crowns appear to have been approximately as follows: p2 length 29 mm, width 14.2 mm; p3 length 27 mm, width 16 mm. These dimensions and the pattern of the enamel foldings show that the teeth cannot be referred either to *EQUUS CURVIDENS* or to any of the three species of *Hippidium* whose teeth have been minutely described and figured by Sefve*. Their affinity lies rather with the genus *Parahipparion*. In view of the difficulties that beset the study of isolated equine teeth, especially those of the lower series, it would perhaps be unwise to attempt the specific identification of these two lower premolars; but it is

*Die Fossilien Pferde Süd Americas; Kungl. Svenska Vet. Hand., 1912, Band 48, No.6.

10.

significant that among all the teeth with which they have been
compared, they most nearly find their counterparts in the first
and second lower deciduous molars, and the first molar, of
Perahipparion peruanum from Tirapata, Peru, figured by Sefve*.

The united length of the first two milk molars of this last
mentioned specimen amounts to approximately 56 mm; and this
measurement exceeds the restored united length of the two teeth
under discussion by 2 mm, which is very nearly the difference
in length that one might expect to find between the first and
second lower deciduous teeth and their permanent successors.
So many variable and uncertain factors enter into these measure-
ments that the comparison should not be carried too far.

In another lower cheek-tooth (p2) from Ayusbamba the forms
of the inner valleys (text-figure 6) are simpler than in the teeth
last described, the contrast in this respect being almost too
marked to be readily accounted for the fact that the teeth present
different stages of wear. It should be noted that the teeth
shown in text-figures 5 and 6, possess, in common, a very deep
outer valley that penetrates between the inner valleys and nearly
traverses the crown. The deepening of the outer valley, according
to Sefve's observation, characterizes *P. devillei* and *P. peruanum*,
and distinguishes them from *P. saldiasi*. The premolar of text-
figure 6 measures, on the crown, 29 mm x 14 mm. In its enamel
pattern, as well as in its size, it is remarkably like the p2 of
*P. devillei*, which has a length of 28 mm and a width of 13 mm.
Although the species of the Ayusbamba specimen is not determined
by the above comparison, there is no doubt that it belongs under

* Hyperhippidium; Mungl.Svenska Vet.Hand.1910,Band 46,No.2,Taf.2,fig.4

+ The united length of overlapping teeth is less than the sum of
their individual lengths.

‡Sefve,1912; Taf.2,fig.21.

11.

the genus *Parahipparion*.

Examination of an upper molar (text-figure 7) leads to about the same conclusions as were obtained from the study of the lower teeth already described. This tooth appears to be either the first or the second upper molar of the right side. Probably it is the first. The length is 21.5 mm and the width 22 mm. The depth of the crown is greatly reduced, only about 30 mm of the prism being left. In fact it is so low as to present an almost senile stage of wear. Under these circumstances not only would the pattern of the enamel foldings be simplified, as compared with the condition at four or five years of age, but the anteroposterior diameter or length of the crown would be considerably reduced. The width of the crown has probably been a little reduced also, but judging from the very slight convergence of the labial and lingual sides of the prism, this transverse reduction is very small, probably not exceeding 1 mm. Making due allowance for advanced stage of wear and for individual variation, it is conceivable that the enamel pattern of this tooth might have been derived from the pattern exhibited by the first upper molar of any one of the species of *Parahipparion* in which the true molars have been observed. These teeth have not been observed in *P. peruanum*, the species that from its occurrence at Tirapata would seem most likely to be found in Pleistocene formations at Ayusbamba. On the whole it appears that very little progress toward the specific identification of the upper molar of text-figure 7 is to be made through the study of its enamel pattern alone. Much better results can be obtained by comparing its dimensions with those of the various species of *Parahipparion*. Accordingly the length and width of the upper true molars of *P. saldiasi*, *P. bolivi*—

13

The width of the crown of the upper molar from Ayusbamba, viz. 22 mm, is less than that recorded, in the table, for m' of any species of *Parahipparion*. *P. devillei* comes nearest with a width of 25 mm for m', while *P. saldiasi* and *P. bolivianum* are much farther removed. A direct comparison with the first molar of *P. peruanum* is impossible, the permanent upper molars of that species being unknown; but as far as any inference can be drawn from the transverse dimensions of the deciduous teeth, I should expect to find the width of m' of *P. peruanum* about equal to that of *P. saldiasi*. Whether this inference is correct or not, the isolated upper molar from Ayusbamba is evidently from some small-sized species of *Parahipparion*.

The posterior portion of the skull of *Parahipparion* has never been described, although five species of the genus have been recognized. The only cranial parts, besides the teeth, that have previously been collected, are the maxillary, premaxillary and palatine elements, and the mandible. Therefore the Yale Expedition was fortunate in securing at Ayusbamba a skull apparently belonging to this genus. This specimen, though far from complete, is composed largely of parts regarding which we have had no definite knowledge. A careful search was made along the bottom and sides of a small ravine where this specimen occurred, but the rest of the skull was not found.

There was, in the possession of Dr. Romuãdo Aguilar of Cuaco, a fragment of a small equine skull with several teeth, that came from very near this same place. Although I have had no opportunity to examine this specimen closely, its general

14

appearance and the circumstances under which it was collected, lead me to believe that it may be from the same skull as the portion taken later by the Yale Expedition. I trust that Dr. Aguilar will soon publish views and a description of his specimen.

The posterior part of the skull is shown in Plate II, figure 1, together with two disconnected but important pieces of the nasal and premaxillary bones that are placed, as nearly as possible, in their true relative positions. Compared with the view of the skull of *Onohippidium compressidens* (figure 2) it is at once seen that the skull from Ayusbamba was characterized by slender, freely projecting nasal bones, very similar to those of *Onohippidium* and *Hippidium bonaerense*. A conspicuous cheek-groove, beneath the elongated ascending process of the premaxilla, corresponds in part to the anterior chamber of the "fossa lacrymalis" of *Onohippidium*. It is the latter genus that this skull approaches most nearly in the form of the nasal bones, in the cheek-grooves of the maxillae, and in the depth of the alveolar portions of the maxillae below the facial crests. In the shape of the zygomata and in the narrower preorbital breadth of the skull, as seen in figure 3, the resemblance is rather with *Hippidium bonaerense*. The form of the foramen magnum and the occipital condyles may be seen in figures 4 and 5. The skull, while indicated by the sutures to be that of a full-grown animal, is smaller in nearly every dimension than that of *Hippidium bonaerense*, especially in the transverse measurements. The contrast in size with the skull of *Onohippidium* is even greater. To compare the skull from

16

Although the skull from Ayusbamba and that of *Onohippidium compressidens* differ greatly in actual size, their proportions are so nearly alike that their generic separation by cranial characters alone, irrespective of size, would be difficult and unsatisfactory. In referring the Ayusbamba skull provisionally to *Parahipparion*, I am influenced not only by the slight differences in cranial form, but also by what is known of the geographic distribution of the genera *Parahipparion* and *Onohippidium*.

The fossil horses that have been found in the mountains of Peru and Bolivia apparently belong to small short-legged species of *Parahipparion*, while *Onohippidium compressidens*, an animal with larger head and longer limbs, has been found only in the pampas formation of the Province of Buenos Ayres.