166

ScientificIntelligence.

literature,* in which anomalous internal bast arises in a verydifferent way, being developed entirely secondarily, through t h eactivity of a cambium, gradually extending itself inward at t h enodes, and entering the pith through the gaps in the fibro-vascular ring, which are left by the outgoing leaf-trace bundles.
B. L. E.

5. Die Gattung Phyllostylon und Hire Beziehungen zu Samaroceltis.
(Oestr. bot. Zeitschr., D e c , 1890.) —Dr. P . FAUBEET,
the author of this short article, having been fortunate enough toobtain fruiting specimens of Phyllostylon Srasiliense
Capan,
finds that they correspond closely to plants upon which the new
genus Samaroceltis has recently been founded. The conclusion
is naturally drawn that the two genera must be united under theolder name Phyllostylon.
While studying these plants D r s .
Taubert and Urban have discovered a Cuban form of Phyllostylon
almost identical with a P a r a g u a y species. This is an additional
point in proving a relationship, which seems t o exist between theflora of the West Indies and the southern United States on the
one hand, and of P a r a g u a y and the Argentine Republic on theother, a peculiarity of botanical geography for which no adequate
explanation has as yet been offered.
B. L. E .
6. JSine Notiz iXber das Verhalten der Chlorophyllbdnderinden Zygoten

der . Spirogyraarten;

by VINCENTCHMIKLEVSKY.

(Bot. Zeit. 1890, viii, pp. 773-780).—Owing perhaps to the greater
importance ascribed to the cell-nucleus, the conduct of the chloroplaslids, during reproduction among the Conjugates, seems until
now to have received b u t little attention. I t has long been supposed that the chlorophyll-bodies of the t w o conjugating cells insome way unite, both contributing to the substance of the newchloroplastid of t h e zygospore.
In the interesting paper justnamed, the author shows that this idea is altogether unfounded.
In the species of Spirogyra studied by him, the chloroplastid o f
the zygospore develops directly from that of the conjugatingcell within which the spore is formed (female cell), while thechlorophyll of the other conjugating cell takes no part in thisprocess, but gradually loses its color, disintegrates, and after
remaining sometime in the spore as a minute mass of brownish
pigment, finally disappears altogether. These facts add, as theauthor concludes, a striking argument for the theory that hereditary traits are transmitted entirely by the agency of the nuclei,,the vegetative parts of the cells being, in this regard, entirely
neutral.
B. L. E .
* Cf. Armales du Jard. bot. de Buitenzorg, vol. viii, pp. 102-111.

Index

to Volumes

XXXI-XL.

An EXTRA NUMBER giving a full index to volumes X X X I - X L , .
and forming pp. 505-548 of volume X L , was issued in January.
Sent only to those who specially order it—price seventy-five cents..

APPENDIX.

A R T . X I X . — T h e giganticof NorthAmerica;*Geratopsidce,

or hornedb y O. C. M A R S H .

Dinosaurs,( W i t h Plates I - X . )inT w o years ago, at t h e B a t h meeting of t h e A s s o c i a t i o n , . . . ? ; < > t / I h a d t h e honor to present to this section a paper in _ which I - 'compared t h e principal k n o w n Dinosaurs of E u r o p e with those•, ;of America.f I n this communication, I referred to some| \peculiar reptilian remains from the Gosau formation of Austria,
a n d compared t h e m with certain Laramie fossils from America,
about which I hoped soon t o have more definite information.
A s ' an indication of t h e rapidity w i t h which knowledge of.ancient life is advancing, it may interest you t o know what
has been learned, in two years, concerning this single g r o u p oft h e remarkable reptiles k n o w n as Dinosauria.
This group, I
have t e r m e d t h e Ceratopsidas, and I shall speak e s p e c i a l l y ^ ,the forms I have recently investigated, a n d hope to describe
more fully later, u n d e r t h e auspices of t h e United States
Geological Survey.
T h e geological horizon of t h e Geratopsidce, in America, is adistinct one i n t h e upper Cretaceous, and has n o w been traced
nearly eight h u n d r e d miles along t h e eastern flank of t h e
Bock'y Mountains.
I t is marked almost everywhere b yremains of these reptiles, and hence I have called t h e strata
containing them, t h e Ceratops beds. T h e y are fresh-water orbrackish deposits, which form a part of t h e so-called Laramie,b u t are below the uppermost beds referred to that group.
* Read before Section C of the British Association for the Advancement of
Science, at the Leeds meeting, September 4, 1800. See also this Journal (3), vol.
xxxvi, p. 477, December, 1888; vol. xxxvii, p. 334, April, 1889; vol. xxxviii, p.
173, August, 1889, p. 501, December, 1889; and vol. xxxix, p. 81, January, 1890,
p. 418, May, 1890.
•(•Report of the British Association for the Advancement of Science for 1888,.p. 660. London, 1889. Abstract, this Journal (3), vol. xxxvii, p. 323, April, 1889.

168

0. G. Marsh—The gigantic Ceratopsidce,

or homed. Dinosaurs, of North America.

The fossils associated with the Ceratopsidce are mainly
Dinosaurs, representing two or three orders, and several
families. Plesiosaurs, crocodiles and turtles of Cretaceous
types, and many smaller reptiles, have left their remains inthe same deposits. Numerous small mammals, also of ancient
types, a few birds, and many fishes, are likewise entombed inthis formation. Invertebrate fossils and plants are not uncommon in the same horizon.

connection with it. In front of the premaxillaries, there is alarge, massive bone not before seen in any vertebrate, which
I have called the rostral bone (os rostrale). It covers theanterior margin of the premaxillaries, and its sharp inferioredge is continuous with their lower border. This bone ismuch compressed, and its surface very rugose, showing that itwas covered with a strong, horny beak. It is a dermal ossification, and corresponds to the pre-dentary bone below.
The latter, in Triceratops, is also sharp and rugose, and likewise was protected by a strong, horny covering. The two
together closely resembles the beak of some of the turtles, and,as a whole, must have formed a most powerful weapon of
offense.
In one skull figured (Plate I, figures 1-2), the rostral bone
was free, and was not secured. This was also true of the
pre-dentary bone and the nasal horn-core. Hence, these parts
are represented in outline, taken from another specimen inwhich they are all present, and in good preservation. In
another skull represented (Plate I, figure 4, and Plate II,,
figures 1-3), the rostral bone and nasal horn-core are in
position, and firmly coossified with the adjoining elements.
The premaxillary bones are large, and much compressedtransversely. Their inner surfaces are flat, and meet eachother closely on the median line. In old specimens, they arefirmly coossified with each other and with the rostral bone.
Each sends upward a strong process to support the massive
nasals. Another process, long and slender, extends upwardand backward, forming a suture with the maxillary behind,and uniting in front with a_ descending branch of the nasal.
The premaxillaries are much excavated externally for thenarial aperture, and form its lower margin. They are entirely
edentulous.
The maxillaries are thick, massive bones of moderate size,and subtriangular in outline when seen from the side. Their
front margin is bounded mainly by the premaxillaries. They
meet the prefrontal and lachrymal above, and also the jugal.
The alveolar border is narrow, and the teeth small, with onlya single row in use at the same time.
The nasal bones are large and massive, and greatly thickened
anteriorly to support the nasal horn-core. In two of the skulls
figured, these bones are separate, but in older individuals, they
are firmly coossified with each other and with the frontals.
The nasal horn-core ossifies from a separate centre, but in
adult animals, it unites closely with the nasals, all traces of theconnection being lost. It varies much in form in different
species.

T H E SKULL.

The skull of Triceratops, the best known genus of thefamily, has many remarkable features. First of all, its size,,in the largest individuals, exceeds that of any land animal
hitherto discovered, living or extinct, and is only surpassed bythat of some of the Cetaceans. The skull represented naturalsize in two of the diagrams was that of a comparatively young
animal, but is about six feet in length. The type specimen of
Triceratops horridus was an old individual, and the head,
when complete, must have been seven or eight feet in length.
Two other skulls, nearly perfect, represented by life-size
sketches, and several others from the same horizon, havealmost equal dimensions.*
Another striking feature of the skull is its armature. Thisconsisted of a sharp, cutting beak in front; a strong horn on
the nose; a pair of very large, pointed horns on the top of
the head; and a row of sharp projections around the marginof the posterior crest. All these had a horny covering ofgreat strength and power. For offense and defense, they formed
together an armor for the head as complete as any known.
This armature dominated the skull, and in a great measure,,,determined its form and structure. In some forms, the armature extended over portions of the body.
The skull itself is wedge-shaped in form, especially when
seen from above. The facial portion is very narrow, and muchprolonged in front. In the frontal region, the skull is massive
and greatly strengthened to support the large and lofty horncores which formed the central feature of the armature. The^huge, expanded, posterior crest, which overshadowed the back of
the skull and neck, was evidently of secondary growth, apractical necessity for the attachment of the powerful ligaments and muscles that supported the head (Plate I, figures
1-4).
The front part of the skull shows a very high degree of
specialization, and the lower jaws have been modified in* The large diagrams shown when this paper was read are most of them
represented by reduced figures in the accompanying Plates, I-X.

169

170

0. G Marsh—The gigantic Geratopsidw,

or homed Dinosaurs, of North America.

The frontal bones are quite short, and early unite with eachother and with the adjoining elements, especially those behindthem. The frontal or central region of the skull is thus
greatly strengthened to support the enormous horn-cores whichtower above. These elevations rest mainly on the postfrontalbones, but the supra-orbitals and the post-orbitals are also
absorbed to form a solid foundation for the horn-cores.
These horn-cores are hollow at the base (Plate I, figure 3),
and in general form, position, and external texture, agree withthe corresponding parts of the Bovidw.
They vary much inshape and size in different species. They 'were' evidently
covered with massive, pointed "horns, forming most powerfuland effective weapons.
The orbit is at the base of the horn-core, and is surrounded,
especially above, by a very thick margin. It is oval in outline,
and of moderate size (Plate I, figure 1, b).
The postfrontal bones are very large, and meet each otheron the median line. Posteriorly, they join the squamosals andthe parietals. At their union with the latter, there is a median
foramen (Plate I, figure 3, x) which apparently corresponds tothe so-called "parietal foramen."* In old individuals, it isnearly or quite closed. When open, it leads into a large sinus,
extending above the brain-case into the cavities of the horncores. This foramen has not before been observed in Dinosaurs.
The enormous posterior crest is formed mainly by theparietals, which meet the postfrontals immediately behind thehorn-cores. The posterior margin is protected by a series of
special ossifications, which, in life, had a thick horny covering.
These peculiar ossicles, which extend around the whole crest,
I have called the epoccipital bones (Plate I, figures 1-4, e).
In old animals, they are firmly coossified with the bones on
which they rest.
The lateral portions of the crest are formed by the squamosals,
which meet the parietals in an open suture. Anteriorly, theyjoin the postfrontal elements which form the base of thehorn-core, and laterally, they unite with the jugals. The
supra-temporal fossae lie between the squamosals and theparietals.
The base of, the skull has been modified in conformity with •its upper surface. The basi-occipital is especially massive, andstrong at every point. The occipital condyle is very large, andits articular face, nearly spherical, indicating great freedom of
motion. The basi-occipital processes are short and stout. The
basi-pterygoid processes are longer and less robust.

The foramen magnum is very small, scarcely one-half_ the•diameter of the occipital condyle. The brain-cavity is especiallydiminutive, smaller in proportion to the skull than in any
other known reptile.
The exoccipitals are also robust, and firmly coossified withthe basi-occipital. They form about three-fourths of theoccipital condyle, as in some of the Chameleons. _ The supra•occipital is very small, and its external surface is excavatedinto deep cavities. It is coossified late with the parietals
above, and with, the exoccipitals on the sides (Plate I,
figure 2).
The quadrate is robust, and its head much compressed. The
latter is held firmly in a deep groove of the squamosal. The
anterior wing of the quadrate is large and thin, and closely
united with the broad blade of the pterygoid.
The quadrato-jugal is a solid, compressed bone, uniting the•quadrate with the large descending process of the jugal. In
the genus Trioeratops, the quadrato-jugal does not unite withthe squamosal. In Gemtops, which includes some of thesmaller, less specialized forms of the family, the squamosal isfirmly united to the quadrato-jugal by suture.
The quadrato-jugal arch in this group is strong, and curves
upward, the jugal uniting with the maxillary, not at its
posterior extremity, but at its upper surface (Plate I, figure 1).
This greatly strengthens the centre of the skull which supports
the horn-cores, and also tends to modify materially the elementsof the palate below. The pterygoids, in addition to theiristrong union with the quadrate, send outward a branch, whichcurves around the end of the maxillary.
The palatine bones are much smaller than the pterygoids.
'They are vertical, curved plates, outside and in front of thepterygoids, and uniting firmly with the maxillaries. The
vomers join the pterygoids in front, where they appear as thinhones, closely applied to each other.
The transverse bones give some support to the maxillaries,
which are' further strengthened by close union with thepterygoids. They meet the pterygoids behind, and the palatines in front.
The lower jaw shows no specialization of great importance,with the exception of the pre-dentary bone already described.
'There is, however, a very massive coronoid process rising fromthe posterior part of the dentary (Plate I, figure 1). The
articular, angular, and surangular bones, are all short and strong,but the splenial is very long and slender, extending to thepre-dentary. The angle of the lower jaw projects but little
behind the quadrate.

* The name usually applied to this aperture is misleading, as in Chameleo andgome other reptiles, the foramen is not in or near the parietal bones. It may
more properly be called the " pineal foramen."

171

172

0. G. Marsh—The

gigantic

Ceratopsidw,

T H E BRAIN.

The brain of Triceratops appears to have been smaller in.
proportion to the entire skull, than in any known vertebrate.
The position of the brain in the skull does not correspondto the axis of the latter, the front being elevated at an angle ofabout thirty degrees (Plate II, figure 7).
The brain-case is well ossified in front, and in old animals,
there is a strong septum separating the olfactory lobes.
T E E T H OF TRICERATOPS.

The teeth of Triceratops and its near allies are very remarkable in having two distinct roots. This is true of both theupper and lower series. These roots are placed transversely inthe jaw, and there is a separate cavity, more or less distinct,
for each of them. One of these teeth from the upper jaw,
represented by enlarged figures (Plate II, figures 8-11), andanother tooth here exhibited, are typical of the group.
The teeth form a single series only in each jaw. The upperand lower teeth are similar, but the grinding' face is reversed,
being on the inner side of the upper series, and on the outerside of the lower series. The sculptured surface in each series
is on the opposite side from that in use.
The teeth are not displaced vertically by their successors,,
but from the side. The crown of the young tooth, also with
two strong roots, cuts its way between the alveolar margin andthe adjacent root of the old tooth,eometimes advancing between,
the two roots, as might be expected..
The teeth in this family are entirely confined to themaxillary and dentary bones. The rostral bone, the premaxillaries, and the pre-dentary, are entirely edentulous.
CERVICAL AND DORSAL V E R T E B R A .

The atlas and axis of Triceratops are coossified with eachother, and at least one other vertebra is firmly united withthem. These form a solid mass, well adapted to support theenormous head (Plate III, figure 1). The cup for the occipital
condyle is nearly round, and very deep. The rib of the second
vertebra is coosified with it, but the third is usually free. The
centrum of the fourth vertebra is free, and the remaining
cervicals are of the same general form, all having their articularfaces nearly flat (Plate I I I , figure 2).
/
The anterior dorsal vertebrae have very short centra, withflat articular ends, and resemble somewhat those of Stegosaurus,
especially in the neural arch (Plate I I I , figures. 3-4).
The posterior trunk vertebras have also short, flat centra,,but the diapophyses have faces for both the head and tubercle.

or homed Dinosaurs, of North America.

173;of the ribs, as in. Crocodiles, a feature not before seen in
Dinosaurs (Plate I I I , figures 5-6).
T H E SACRUM.

The sacrum was strengthened by union of several vertebrae,,ten being coossified in one specimen of Triceratops (Plate I V ) .
The middle or true sacral vertebras have double transverse
processes, diapophyses being present, and aiding in supporting
the ilium. This' character has been seen hitherto, in the
JDinosauria, only in Oeratosaurus and some other Theropoda.
The main support of the pelvis was borne by four vertebras,
which evidently constituted the original sacrum. In front ofthese, two others have only simple processes, and apparently
were once dorsals or lumb'ars. Three vertebrae next behind
the true sacrum have also single processes, and the fourth, orlast of the series, has the rib process weak, and not reaching
the ilium (Plate IY). Seen from the side, the sacrum is mucharched upward, and the neural spines of the true sacrum arefirmly coossified. In the median region, the sacral vertebrae
have their centra much compressed, but the last of the series
are widely expanded transversely. The whole appearance ofthe sacrum is remarkably avian. The neural canal of thesacral vertebrae has no special enlargement, thus differing
widely from that in Stegosaurus.
T H E CAUDAL YERTEBR^:.

The caudal vertebras are short, and the tail was of moderate:
length. The first caudal has the anterior face of the centrum
concave vertically, but flat transversely, and a short, massive
neural spine with expanded summit (Plate V, figures 1-3).
In the median caudals, the centra have biconcave articular faces,.
and weak neural spines. The distal caudals are longer thanwide, with the ends nearly round, and concave.
T H E SCAPULAR A R C H AND FORE LIMBS.

The scapula is massive, especially below. The shaft is longand narrow, with a thin edge in front, and a thick posterior
margin above the glenoid fossa. The distal portion has a.
median external ridge, and a thick end (Plate VI, figure 1, so).
The coracoid is rather small, and in old individuals may
become united to the scapula. It is sub-rhombic in outline, andis perforated by a large and well-defined foramen. ISTo indications of a sternum have yet been found in this group.
The humerus is large and robust, and similar in form to thatof Stegosaurus. It is nearly as long as the femur in ona

174

O. C. Marsh—The

gigantic Ceratqpsidce,

individual, proving that the animal walked on all four feet.
The radius and ulna are comparatively short and stout, and thelatter has a very large olecranon process.
There were five well-developed digits in the manus. The
metacarpals are short and stout, with rugose extremities. The
distal phalanges are broad and hoof-like, showing that the fore
feet were distinctly ungulate (Plate IX, figures 1-6).
T H E PELVIS.

The pelvis in this group is very characteristic, and the threebones, ilium, ischium, and pubis, all take a prominent part informing the acetabulum. The relative size and position ofthese are shown in the diagram (Plate V I I , figure 1), which
represents the pelvic elements as nearly in the same plane as
their form will allow, while retaining essentially their relative position in life.
The ilium is much elongated, and differs widely from that inany of the known groups of the Dinosauria.
The portion in
front of the acetabulum forms a broad, horizontal plate, whichis continued backward over the acetabulum, and narrowed in
the elongated, posterior extension. Seen from above, the ilium,
as a whole, appears as a nearly horizontal, sigmoid plate. From
the outside, as shown in the diagram, the edge of this broad
plate is seen.
The protuberance for the support of the pubis is comparatively small, and elongated. The face for the ischium ismuch larger, and but little produced. The acetabular face of
the ilium is quite narrow.
The pubis is massive, much compressed transversely, withits distal end widely expanded, as shown in the figure (Plate
VII). There is no post-pubis. The pubis itself projects forward, outward, and downward. Its union with the ilium is
not a strong one, and is similar to that seen in the pubis of•Stegosaurus.
The ischium is smaller than the pubis, but more elongate.
Its shaft is much curved downward and inward, and in thisrespect, it resembles somewhat the corresponding part of thepubis of the ostrich. There is no indication that the two
ischia met closely at their distal ends, and they were probably
united only by cartilage.
A comparison of this pelvis with that of Stegosaurus showssome points of resemblance, but a wide difference in each of
the elements. The pubis corresponds, in its essential features,to the pre-pubis of /Stegosaurus, but the post-pubis is wanting.** One pubis recently discovered, and represented in Plate VII, has a short,splint-like process, which may, perhaps, be a remnant of a post-pubic element,
although it does not have the position of the post-pubic bone in other Dinosaurs.

or horned Dinosaurs, of North America.

175

T H E POSTERIOR LIMBS.

The femur is short, with the great trochanter well developed.
The shaft is comparatively slender, and the distal end much
expanded. The third trochanter is wanting, or represented
only by a rugosity (Plate V I I I , figure 1).
The tibia is of moderate length, and resembles that of
Stegosaurus.
The shaft is slender, but the ends are much
expanded. The fibula is very slender, and the distal end wasclosely applied to the front of the tibia (Plate V I I I , figures2-3). In adult individuals, the astragalus is firmly coossified
with the distal end of the tibia, as in Stegosaurus.
The metatarsal bones which were functional are rather long,,but massive. Their phalanges are stout, and the distal ones,.
broad and rugose, indicating that the digits were terminatedby very strong hoofs (Plate IX, figures 7-12).
All the limb bones and vertebrae in Triceratops, and thenearly allied genera, are solid.
T H E DERMAL ARMOR.

Beside the armature of the skull, the body also in theGeratopsidm was protected. The nature and position of the
defensive parts in the different forms cannot yet be determinedwith certainty, but various spines, bosses, and plates havebeen found, that clearly pertain to the dermal covering ofTriceratops, or nearly allied genera. Several of these ossifications were probably placed on the back, behind the crest of
the skull (Plate X), and some of the smaller ones may havedefended the throat, as in Stegosaurus.
The remarkable extinct reptiles here briefly described present many characters which separate them widely from allother known Dinosaurs. Some of these characters are evidently the result of a high degree of specialization, but there
are others that cannot be thus explained. The specialization
evidently began in the skull,-and there reached its greatest;development. The peculiar armature of the skull has a partial
parallel in the genus Phrynosoma among the recent lizards,
and Meiolania among the extinct turtles. A suggestion of
the parietal crest may be seen in the existing Ghameleo, which
offers other points of resemblance in its skull and skeleton.
These features, however, indicate only a very remote affinity,
and it is among the Dinosaurs alone that this group can beplaced, as a distinct family, in the order Omithopoda.
The main characters which separate the Oeratopsidce from allother known families of the Dinosauria are as follows :176

0, C. Marsh—The

gigantic Ceratopsidce,(1) A rostral bone, forming a sharp, cutting beak.
(2) The skull surmounted by massive horn-cores.
(3) The expanded parietal crest with its marginal jarmature.
(4) The teeth with two distinct roots.
(5) The anterior cervical vertebrae coossified with each other.
(6) The posterior dorsal vertebrae supporting, on the diapophysis, both the head and tubercle of the rib.
The Ceratopsidce resemble,, in various points, the Stegosauriaof the Jurassic, especially in the vertebrae, limbs, and feet.
The greatest difference is seen in the skull, but the pelvic arch,also, shows a wide divergence. In the Ceratopsidce, there isno marked enlargement of the spinal cavity in the sacrum, andthere is no post-pubis.
. The characters above given are based upon fossils which I
have personally investigated, including the type specimensof Ceratops and Triceratops, on which, mainly, the family
Ceratopsidce was established. The material now at my command includes the remains of many individuals, among which
are portions of about twenty different skulls, and some of these
are nearly perfect. In the memoir now in preparation, I shallfully describe and illustrate all the more important of these
specimens, and likewise discuss their relations to allied forms.
The generic names, Agathaumas, Cratceomus, Monoclonius,and one or two others, have been given to fragmentary fossils,
which may belong to this group, but these remains, so far as
made known, appear quite distinct from those here described.
In conclusion, let me say a word as to how the discoveries
here recorded have been accomplished. The main credit for
the work justly belongs to my able assistant, Mr. J. JB. Hatcher,
who has done so much to bring to light the ancient life of the
Rocky mountain region. I can only claim to have shared a
few of the dangers and hardships with him, but without his
skill and energy, little would have been accomplished. If you
will bear in mind that two of the skulls, represented in the
diagrams before you, weighed • nearly two tons each, whenpartially freed from their matrix, and ready for shipment, in a
deep, desert canon, fifty miles from a railway, you willappreciate one of the mechanical difficulties overcome. WhenI add that some of the most interesting discoveries weremade in the hunting grounds of the hostile Sioux Indians,
who regard such explorations with superstitious dread, you will
understand another phase of the problem. I might speakof even greater difficulties and dangers, but the results attained
repay all past efforts, and I hope at no distant day to havesomething more of interest to lay before you.

or horned Dinosaurs, of Worth America.
EXPLANATION177

OF PLATES.

PLATE I.

FIGURE 1.—Skull of Triceratops ftabellatus, Marsh; seen from the left side.
a, nasal opening; 6, orbit; c, supra-temporal fossa; e, epoccipital;h, horn-core; h', nasal horn-core; p, pre-dentary; q, quadrate;r, rostral bone.
FIGURE 2.—The same skull; seen from behind.
d, dentary; p, parietal; pd, pre-dentary; s, squamosal.
FIGURE 3.—Skull of Triceratops serratus. Marsh; diagram; seen from above.
d, epijugal bone; /, frontal; fp, postfrontal; /, jugal; m, maxillary;n, nasal; pf, prefrontal; pm, premaxillary; a, pineal foramen.
FIGURE 4.—Skull of Triceratops prorsus, Marsh; seen from the front.
All the figures are one-twentieth natural size.
PLATE II.

.FIGURE 1.—Anterior.part of skull of Triceratdps prorsus, Marsh; side view; oneeighth natural size.
FIGURE 2.—Front view of same.
FIGURE 3.—The same; seen from below.
V, nasal horn-core; n, nasal; na, narial aperture; pm, premaxillary;r, rostral bone.
FIGURE 4.—Pre-dentary of same individual; side view; one-eighth natural size.
FIGURE 5.—Top view of same specimen.
FIGURE 6.—Bottom view.
a, anterior end; 6, upper border; d, groove for dentary; s, symphysis.
FIGURE 7.—Oast of brain-cavity of Triceratdps serratus, Marsh; side view; onehalf natural size.
c, cerebral hemispheres; cb, cerebellum; m, medulla; ol, olfactory
lobe; on. optic nerve; p, pituitary, body.
FIGURE 8.—Maxillary tooth of Triceratops serratus; outer view; natural size.
FIGURE 9.—The same tooth ; side view.
FIGURE 10.—The same tooth; inner view.
FIGURE 11.—The same tooth; seen from below.
PLATE

III.

FIGURE 1.—Anterior cervical vertebra? of Triceratops prorsus, Marsh; side view.
FIGURE 2.—Fourth cervical vertebra of same series; back view.
a, anterior face of atlas; d, diapophysis; n, neural canal; p, posterior face of fourth vertebra; r, rib; s, neural spine of axis;s', neural spine of third vertebra; s", neural spine of fourthvertebra; %', posterior zygapophysis.
FIGURE 3.—Anterior dorsal vertebra of same species; side view.
FIGURE 4.—The same vertebra•; front view.
FIGURE 5.—Posterior dorsal vertebra of same species; side view.
FIGURE 6.—The same vertebra; front view.
a, anterior face of centrum; h, facet for head of rib; p, posterior faceof centrum; s, neural spine; t, facet for tubercle of rib; *, anterior
zygapophysis.
All the figures are one-eighth natural size.
PLATE

IV.

FIGURE 1.—Sacrum of Triceratops prorsus, Marsh; seen from below; one-eighth
natural size.
a, anterior face of first sacral vertebra; p, posterior face of last sacralvertebra; s, neural spine of last vertebra; z,. anterior zygapophysis
of first vertebra; 1-10, transverse processes, left side.

178

0. C. Marsh—The gigantic Ceratopsiclce.
PLATE V.

FIGURE 1.—First caudal vertebra of Triceratops prorsus, Marsh; side view.
FIGURES 2-3.—Front and back views of same vertebra.
FIGURE 4.—Median caudal of same species; side view.
FIGURES 5-6.—Front and back views of same vertebra.
FIGURE T.—More distal caudal of same species; side view.
FIGURES 8-9.—Front and bottom views of same vertebra.
FIGURES 10-12.—Distal caudal of same species; side, front, and bottom views.
a, anterior face of centrum; c, face for chevron; n, neural canal •;,p, posterior face of centrum; r, rib; s, neural spine; z, anterior
zygapophysia; '/, posterior zygapophysis.
All the figures are one-eighth natural size.
PLATE

VI.

FIGURE 1.—Right scapula and coracoid of Triceratops prorsus, Marsh; side viewFIGURE 2.—Right humerus of same species; front view.
FIGURE 3.—Left ulna of same species; front view.
cr, coracoid; g, glenoid fossa ; h, head; o, olecranon; r, radial crest;:r', face for radius; s, suture ; sc, scapula.
All the figures are one-eighth natural size.
PLATE

VII.

FIGURE 1.—Pelvis of Triceratops flabellatus, Marsh; side view; one-twelfth,
natural size.
a, acetabulum; il. ilium ; is, ischium; p, pubis.
FIGURE 2.—Pubis of Triceratops prorsus, Marsh; side view; one-eighth natural size..
FIGURE 3.—The same pubis; top view.
FIGURE 4.—The same; side view.
a, proximal end; b, face for ilium; c, pubic process; d, distal end.
PLATE T i l l .
FIGURE 1.
FIGURE 2.
FIGURE 3

Left femur of Triceratops prorsus, Marsh; front view.
Left tibia of same species; front view.
The same tibia; distal end; back view.
a, astragalus; c, inner condyle; c', cnemial crest; /, face for fibula;;h, head; t, great trochanter.
All the figures are one-eighth natural size.
PLATE

IX.

FIGURE 1.—Metacarpal of Triceratops prorsus, Marsh; front view; one-eighth
natural size.
FIGURES 2-3.—The same; side and back views.
FIGURE 4.—Terminal phalanx of manus of Triceratops flabellatus, Marsh; front,
view; one-fourth natural size.
FIGURES 5-6.—Side and back views of same.
FIGURE 1.—Metatarsal of Triceratops prorsus; side view; one-eighth natural size..
FIGURES 8-9.—Front'and side views of same.
FIGURE 10.—Ungual phalanx of Triceratops horridus, Marsh; front view; onefourth natural size.
FIGURE 11.—The same; side view.
FIGURE 12.—The same; posterior view.
PLATE X.

FIGURE 1.—Dermal spine of Triceratops; side view; one-eighth natural size.
FIGURES 2-3.—Front and top views of same.
FIGURE 4.—Dermal plate of Triceratops; top view ; one-eighth natural size.
FIGURE 5.—Bottom view of same.
FIGURES 6-7.—Side and end views of same.
FIGURES 8-10.—Dermal plate of Triceratops; top, bottom, and side views; oneeighth natural size.
• •FIGURE 11.—Dermal ossification of Triceratops; side view; one-half natural size,
EiGURE 12.—Front view of same.

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