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VY. { AT HARVARD COLLEGE, CAMBRIDGE, MASS.

Founded by private subscription, in 1861.

RNADEARARAA ANN

No. IGS4,

FIGURES AND DESCRIPTIONS OF CANADIAN
ORGANIC REMAINS.

|

A Wa aaa I.—FOSSILS from the base of the Trenton Group. By J. W. Sanam, bk
Palzontologist of the Geological Survey of the United Kingdom. if: Sk

= IL—GRAPTOLITIDE# from ihe Lower Silurian. By Professor Tasces ts
Hatt, Paleontologist of the State of New York.

“ TIL—CYSTIDE and ASTERIDEA. By E. Bituines. Genus CYCLO- Pe
CYSTOIDES. By H. Brtines and J. W. Sautmr. Paleozoic ae
Bivalve ENTOMOSTRACA. By T. R. Jones, Esq.,F.G.8.

“ TV.—CRINOIDE from the Lower Silurian. By E. Biturnes.

Decades I. and III. are published. Decade IV. will be published on the Ist of J une, ;
and Penne II. in about six months.

FOR SALE BY ie

B. DAWSON & SON, 22 Great St. James Street, Montreal; A. H. ARMOUR & oe yt
Toronto; JOHN WILEY, New York; HECTOR BOSSANGE & SON, Paris, Franters
SAMPSON, LOW, SON & Co. Psuden, England.

Montreal, Ist May, 1859.

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Pibrary of the Museum
COMPARATIVE ZOOLOGY,

AT HARVARD COLLEGE, CAMBRIDGE, MASS.

Founded by private subscription, in 1861.

No. J G38,
UY

GEOLOGICAL SURVEY OF CANADA.

SIR W. EH. LOGAN, F.R.S., DIRECTOR.

FIGURES AND DESCRIPTIONS

OF

CANADIAN ORGANIC REMAINS.

DECADE II.

GRAPTOLITES OF THE QUEBEC GROUP.

BY

JAS MOR Ss OH Ant

MONTREAL: DAWSON BROTHERS.
LONDON, NEW YORK, AND PARIS: BALLIERE.

1865.

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Reine FA OC i.

The Graptolites of the Quebec group, which are the subject of the
present Decade, were first discovered at Point Lévis in 1854, and were
then confided for investigation and description to Professor JAMES Haut of
Albany, the distinguished Palzeontologist of the Geological Survey of the
State of New York. This was prior tu the appointment of Mr. E.
BILiines as Palzeontologist to the Canadian Survey, in 1856. After a
preliminary notice communicated by Professor Haut in 1855, extensive
additions were made to the collection of Canadian Graptolites, which
were placed in his hands; and in 1858 descriptions by him of nearly
all the species here figured were published in the Report of Progress
of the Geological Survey of Canada for 1857, but without illustrations.
Figures of one of the species were however published in the Canadian
Naturalist for June 1858; but various accidental difficulties having
occurred in the preparation and engraving of the plates, the publication
of the Decade has been delayed until the present time. |

It is to be remarked that although the name of Decade, under which
Parts I, I11,,and Iv were published, is still retained, this monograph is
illustrated by not less than twenty-three plates. These are all from
excellent drawings by Mr. R. P. Wurrrietp of Albany. ‘Twenty-one of
them were engraved on steel by Mr. James Dutuim of New York, and
the remaining two were lithographed by Mr. F. J. Swinton of Albany.

W. EH. LOGAN.
GEOLOGICAL Survey OFFICE,
Montreal, December 1864.

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TABLE OF CONTENTS.

CHAPTER I.
INTRODUCTION.

§ I. Nature and form of Graptolites; formerly known only in fragments; regarded by
early writers as of vegetable origin; their reference to Cephalopoda by Wahlen-
berg, Schlotheim, Geinitz, and Quenstedt, page 5.—Their first reference to Poly-
piaria; the supposed affinity of Graptolites to the larve of Echinoderms, 6.—The
name Graptolithus first established, 7—What forms are properly referable to the
genus Graptolithus, 7-8.—Dendrograptus, its mode of growth, and gradations
through Callograptus to Dictyonema, 10-12.—Forms of some Graptolites similar
to the recent genus Crisia, 13.—Forms with diverging stipes, 14.—Doubly serrate
forms (Diplograptus), 15.—Phyllograptus, Retiograptus, Retiolites, Rastrites, 16.
Thamnograptus ; Inocaulis, and its affinities to Graptolites, 18.

§ II. The central or basal portions of Graptolites, 19.—The radicle or initial point, 19.
—The funicle, 19.—The central disc, 20.

§ III. Nature and parts of the stipe, 21.—The solid axis, 21—The common canal, 23.
—The cells, cellules, or calycles ; their form and mode of development, 24.—Their
similarity to the recent genera of Hydroide, 25.—Cell-walls, their double appear-
ance and structure, 27.—EHxcavated cells, 27.—Their internal structure, 28.—Cells
in Retiolites. Apertures of cells in some species of Graptolites; in Dendrograp-
tus, 29.—The cells of Dictyonema, 29, 30.—Ornaments of the test in different
genera and species, 30, 32.

§ IV. Mode of reproduction and development in Graptolites, when first made known,
32.—Different forms of germs, and their reference to species, 34.—Reasons for sup-
posing that the diprionidian forms always existed as simple stipes, 36.—Develop-
ment of cells in different genera, 37.

§ V. Mode of existence, 38.—Simple or compound forms; floating or fixed forms, 39.

§ VI. General characters of the Graptolitide, 40.—The condition of specimens heretofore
described. Genera and sub-genera proposed : reasons for and against retaining these,
40 —43.—Diplograptus, to what forms the term is properly applied, 44.—Peculiar
characters of D. putillus, 44.—Biserrate forms which are properly separable from
Diplograptus, 45.—The genus Retiolites, 46.—Differences observed between Huro-
pean and American specimens, 47.—Retiograptus and other genera considered,
47-50.—Synopsis of the genera of Graptolitide, 50.

§ VII. Geological and geographical distribution of the Graptolitide in the rocks of
Canada and the United States. Equivalency of the American graptolitic beds with
those of Europe, 51.—Mr. Barrande’s opinion of the age of the graptolitic schists in
Northern Europe and in Bohemia, The graptolitic beds in New York. Discovery

iV

TABLE OF CONTENTS.

of a Graptolite in the Potsdam sandstone. The graptolitic beds of Canada, 52

Graptolites of the Utica slate and the Hudson-River formation, 53—54.—Table
showing the vertical distribution of the genera of the family of Graptolitide, 55.—
Table showing the geological distribution of the species of Graptolitide in Canada

and the United States, 56-58.

§ VIII. Historical notice of the genus Graptolithus, 59 - 64.

CHAPTER II.

§ I. Synopsis of the species of Graptolitide from the Quebec group, described in this

Memoir, 65 - 68.

§ Il. Descriptions of the species of Graptolitide illustrated in this Memoir, under the

following genera:

GRAPTOLMEHUS .«e\e!ajs\k.c/s cles sis/aie sieve ue here mis Geka aust toveiterenrie ale tevelsy«' ais (leis(e(e[staie aes
TET OGRA DUS tors jciscoxey els 010) cjereiercle clove a ayeeroRete RAG Hes. Anwae sae » o.eieieere tee
CLIMACOGRAPTUS ....... ehicreleteierodete ae Apusiere ale deeystee © aie ete aie Se Lit
IEA NO TAT rn) as, 0) 016) o's, nile, s\e}/oia' ei eedetors Bisteteravarslekere ais 4 c aa acie sie 's omni ltcs
EURO EURIAIP TTS cle fo\fello] oat ctellsiia ays) ets wb ohayayeter onsleneteltors Salad aes ei sitoyseatnnes Soke Srarerctage 115
PAVTHOGRAPTUS) «\0jcis «ie /s\e\e/s) « aVn vais ralohotainiolalelcfeieiavcisieiavets, cetstelone MeeesHaoas Ll
DENDR.O GRABINUA ttc mysimicraieielerclesielcrielele Arete lens ole leneta aie tiaras catatralstorens SionekS - 126
CATTOGRAP TUS). cic.0 sciceicie ste wets e ateastehacels ois tofe siete tele vciavers ots SU Sisieiewiate eels
DT OMMONE MWA <psie!s:c10oredeteseiei ina stess.sieie sieeve : my lisriva:tureteretarete e eieiate ec efalarotammlents
DIG OGRAP TUBS. ie citisleeisafoieiere = o's sveresejasvaustos SAR Ashen stearelbusls ae cee St
KIMPAMNOGRIAE TUSiertater-.clevele ere es ule teretarevetnie etarclalate ciate: ateraycharcvaloh otevereneroraiteitelaletenmel 0

SUPPLEMENT.

Descriptions of Graptolites from the Utica slate, introduced for comparison and illus-

tration, 143-147.

RINTDTI Ne tisic is Osrows love iaceteiniovel ofatevaleleve/ave laleneliaga tenes rates ateletempetereieiuietale ala\tesajetufarmials (ere etalereteterets

149

APPIMAVINEISS “(ola cs a's roreieh casera vejulotalaye tare fevereltiloleveleilein iaieha‘oteve feratavelaie,slavarereieicis cteiterelere reve sranaratn ts tate mL Ene

ERRATA.

Page 146, 6th line from bottom, and page 147, 4th line from bottom, for Rurxo-
GRAPTUS read RETIOGRAPTUS.

Page 147, second line from bottom, read “ The frond four times enlarged.”

GRAPTOLITES OF THE QUEBEC GROUP.

CHAPTER I.

INTRODUCTION.
§ I.—NATURE AND FORM OF GRAPTOLITES.

Until recently the graptolites were, with two or three exceptions, known
only as simple, straight, or slightly curving linear stipes or stems, usually
lying in the same plane upon the slaty lammee in which they were imbedded.
Nearly all these were evidently fragmentary, and, though varying some-
what in their proportions, rarely exhibited anything that could be regarded
as the commencement or termination of their growth or development.
These bodies, in their flattened condition, present a range of serratures
either on one or on both sides of the stipe; and seldom preserve more
of their substance than a carbonaceous or corneous film or test of extreme
tenuity. Under more favorable circumstances, these serratures are dis-
covered to indicate the apertures of cellules, symmetrically arranged in
reference to each other, and to the axis of the linear stipe. Others show
parallel entire margins, with transverse indentations across the central
portion of the stipe. This appearance we now know to be due to the
direction of the pressure upon the body exerted at right angles to the
cellules, and which will be explained in the sequel.

The earliest opinion regarding these fossils was that they were of vege-
table origin; and they have been thus considered by some authors even
at a very late period. Subsequently, they were referred by Wahlenberg,
and after him by Schlotheim, to the Cephalopoda, being regarded as
extremely slender orthoceratites.. This opinion may have received sup-
port from specimens in such condition as G. sealaris, where the indentations
are limited on each side by a continuous margin; but in such as present
a single or double series of marginal serratures, the analogy seems very
remote. Professors Geinitz and Quenstedt advocated the same view at
a much later date; though it has since been abandoned by these authors,
from more extended investigations. |

A

6 CANADIAN FOSSILS.

Professor Nilsson first suggested that graptolites were Polypiaria, belong-
ing to the family Ceratophyta. Dr. Beck of Copenhagen regarded them
as belonging to the group Pennatulide, of which the Linnean Virgularia
is the most nearly allied existing form. Sir Roderick Murchison has adopted
this view of the relations of the graptolites, in his Silurian System.*
General Portlock has fully recognized the graptolites as zoophytes,
and has pointed out their analogy with Sertularia and Plumularia.

The relations of graptolites with the Cephalopoda had already been
fully disproved by M. Barrande (in the first chapter of his “ Graptolites
de Bohéme’’), before the abundant materials for the refutation were dis-
covered in the graptolites of the Quebec group ; and most naturalists were
already agreed in referring these bodies to the class of Polypi, to which
they doubtless belong.

More recently, Mr. McCrady, of South Osea has published a paper
on the ‘ Zoological Affinities of Graptolites,”’} in which he has endeavored
to show the similarity of the graptolitic forms with the Echinoderm larva,
as illustrated by Miiller. There is certainly much resemblance between
the enlarged figures of that author, and some forms of graptolites in the
shales of the Hudson River valley; while some of the figures with central
discs have a more remote analogy with certain forms from the Quebec
group. Some of the toothed rods of the Echinoderm larvee likewise bear
a resemblance to the graptolites figured by Mr. Suess ;$ and there are still
farther analogies pointed out by Mr. McCrady, which, however, may not
be regarded as of equal value by the greater number of naturalists.

For my own part, although admitting the similarity of form and of some
of the characteristics which were very kindly pointed out to me by Mr.
McCrady, long before his publication, I cannot recognize the analogy
sought to be demonstrated. The establishment of the fact that these
toothlets or serratures are the extensions of true cellules, each one having
an independent aperture, and communicating with a common canal, should
offer convincing argument against these bodies being other than polyp-
bearing skeletons. But, in following the extensive series of forms now
presented to us, we have much evidence to show that some of these were
attached to the bed of the ocean, or to other bodies; while the greater
proportion of the species and genera appear to have never been attached
to the sea-bottom.

It may not be easy to determine precisely the family to which these

* Silurian System, page 694; and letter of Dr. Beck, pp. 695-6.

+ “Remarks on the Zoological Affinities of the Graptolites, by John McCrady, made
before the Eliot Society of Natural History of Charleston, S. C., at the meeting of July
15, 1857.” [Extract from the Proceedings, vol. i.]

t Naturwissenschaftliche Abhandlungen. Vierter Band. Tab. viii and ix.

GRAPTOLITES. i

graptolitic forms should be referred ; nor is it certain that the extensive
series now presented can all properly be referred to a single family.
General Portlock has suggested that these bodies may constitute ‘“ several
genera belonging even to more than one order.”’* That they are true
Polypi, I believe we shall be able to show, both from analogies already
established by various authors, and also from their mode of development
or reproduction as exhibited in some of the species.

The specimens which have usually been observed or represented are
simple disconnected stipes, doubtless the dismembered or fragmentary
portions of fronds, which, presenting in the different species great varieties
of form and aspect when entire, are nevertheless composed of parts so
similar that these fragments, though indicating specific differences, offer
little clue to a knowledge of the entire form.

The name Graptolithus was established by Linnezeus in the first edition
of his ** Systema Nature,” 1736, and applied by him to the straight or
curved forms which are serrated (celluliferous) upon one side only, of
which G. sagittarius has been regarded as the type.t The propriety of
this term is more readily perceived in its application to the fragments of
the stipes of monoprionidian forms than to the central portions of the
body of the same. In the spirally-enrolled forms, or those with four or
more stipes uniting in a central disc, as well as in the variously-branching
forms, the analogy is not so perceptible.

Taking those species which, in the form of their cellules and in the
separated fragments of the frond, would be referred to Graptolites proper,
and tracing them, as we are now able to do in many species, to their
perfect condition, we find a great variety of form and mode of growth.
In the simplest of these we have two stipes diverging from a radicle, or
initial point; and the parts remain so complete as to admit of no doubt

Fig. 1.

ECO DDL»

GRAPTOLITHUS PENNATULUS.

that this is the entire skeleton of the animal. ‘The cellules near the base
of the stipe are not so fully developed ; while also those near the extremi-
ties have not reached their full dimensions, and the last one is sometimes
barely perceptible, or just assuming its form from the common body. These
characteristics are perceptible in the figures upon plates i, 11, and i.

In the next stage we have four simple stipes diverging from an initial
point, and all evidently entire, as shown in the development of the cellules.

* Geological Report on Londonderry, &c., p. 318.
} I shall elsewhere endeavor to show that G. scalaris is a diprionidian form exhibit-
ing only one margin.

8 CANADIAN FOSSILS.

Fig. 2.

GRAPTOLITHUS BRYONOIDES.

In some species of this mode of growth, the bases of the stipes are
united in a more or less expanded dise or cup of the same substance as the
body of the graptolite. The form of this dise is shown on plates v, vi,
Vii, vill, and ix, and also in the accompanying figure of Graptolithus Headi.

Fig, 4. Fig. 3.

GRAPTOLITHUS. OCTOBRACHIATUS,

In a farther development in the same direction, we have fronds with
eight simple stipes, which may or may not be united in a central disc, as
in the accompanying figure.

‘GRAPTOLITES. 9g

In Graptolithus Loganit we have numerous simple ‘stipes united in a
central disc or cup; while in some specimens otherwise precisely similar,
we have no remains of the disc. © In all these species the parts are disposed
in a symmetrical and bilateral arrangement.

Figs. 5 and 6.

-GRraPtoLitaus Locant.

The stipes of this species do not bifurcate beyond the disc, and there

10 CANADIAN FOSSILS.

are no cellules below the last bifurcation. The number of stipes in different
individuals varies from sixteen to twenty-five, so that this charactercannot
be made of specific importance. In another similar species without a central
disc, from the Hudson River formation, we have above forty stipes, which do
not bifurcate, so far as known, beyond the commencement of the cellules.

Fig. 7.

GRAPTOLITHUS MULTIFASCIATUS.

The separated and broken stipes referred by me to Graptolithus sagit-
tarius* are probably of this species, occurring as they do in great numbers
in the same beds in which this was found.

In other species with a similar general arrangement of parts, the main
stipes are frequently bifurcated ; the bifurcations beginning near the base,
and continuing as far as the parts can be traced in the stone (fig. 8).
In some of the species of this character the cellules begin near the base
of the stipes, while in one species they are not known to exist except
on the outer branchlets.

Thus far we trace these forms through what appear to be very natural
stages in the progress of development of the parts, which are all constructed
upon the same plan, presenting only natural, and we may almost say con-
sequent modifications.

The character of stipes and cellules in all these is such that the sepa-
rated fragments would afford no means of indicating whether the part
belonged to a two, four, or eight-stiped species, or to those with numerous
simple stipes, or with branching stipes, unless the fragment retained a
bifurcation.

A variety of form is exhibited in the division termed Dendrograptus,
in which we may conceive of the numerous stipes near the base becoming

* Paleontology of New York, vol. i, page 272, pl. 74, fig. 1.

GRAPTOLITES. 11

Fig. 8.

GRAPTOLITHUS FLEXILIS:

with a portion enlarged.

conjoined into one strong stem, with the bifurcating branchlets spreading
above, and this stem probably fixed in the soil. We then have a represen-
tation of the typical forms of this genus, as in the accompanying figure,
and as illustrated on plate xvii, figs. 8 and 9, of this memoir.

Fig. 9.

DENDROGRAPTUS HALLIANUS.

In this species, as shown in the enlargements of the branchlets, we have

12 CANADIAN FOSSILS.

a form of cellule similar to that in observed fragments of the ordinary
species of graptolites. The cellules are very minute, and, from the
frequent ramifications, this would probably always be recognized as a
branching species.

Some of the forms of Dendrograptus have slender spreading branches,
and less rigid stems than the typical species, but still retain the angular
cellules, as in figs. 1 and 2 of plate xvii. From these we pass almost
imperceptibly to the slender spreading forms which I have termed Callo-
graptus, plate xix, in which there is, apparently, some slight modification
in the form of the cellule ; and on the other hand, there is an almost insen-
sible gradation to the Dictyonema, plate xx, in which the branches are
connected by lateral bars, and the whole developed in a flabelliform or
funnel-shaped. frond, with angular cellules on the inner margins of the
branches. (Fig, 10, plate A.)

DICTYONEMA RETIFORMIS.

There are certain forms of graptolites, which, though possessing linear
straight or slightly curving stipes and angular cellules, like the typical
species, have yet a different aspect, and do not so naturally fall into the
series. Among these we find Graptolithus divergens (fig. 11), where the
bilateral relation of the parts is still shown, but the celluliferous stipes or
branches are arranged on the two sides of a slender stipe or rachis, and
diverge on each side from what appears to be the centre or initial point.

Different specimens show some slight variations of these characters, but
not any essential differences.

GRAPTOLITES. 13

GRAPTOLITHUS DIVERGENS.

Another form, which we know only in small individuals, is illustrated in
the following figures, which remind one of some forms of the recent genus
Crista.

Fig. 12. Fig. 13. Fig. 14. Fig. 15.

(These figures are enlarged to twice their natural size.)

Tn another form with similar angular cellules, we have the following illus-
trations of the mode of occurrence of the species.

Fig. 16,

GRAPTOLITHUS GRACILIS.

14 CANADIAN FOSSILS.

Fig. 17. Fig. 18.

$e we

GRAPTOLITHUS GRACILIS.*

We have still another group, presenting some differences, more particu-
larly in the development and form of cellules, than in their general form ;
and seeming in some species to unite the characters of those having a
single range, with those having a double range of cellules. The simpler
forms of this type are similar to the two-stiped forms of the first series ;
but in all those, whether of two, four, or more stipes, the cellules are
developed on the upper side, or that side opposite to the initial point. In
species like G. sextans, G. divaricatus, and others of this type, the
cellules are on the lower, or same side with the radicle.

Fig. 19.

GRAPTOLITHUS DIVARICATUS:

and enlargement of cellules.

In the accompanying figure of G. divaricatus, the frond consists of two
simple uniserrate stipes ; and the same is true of Gf. sextans, except that

* The fig. 18 was theoretically constructed, but has since been verified by the discovery
of a specimen having the same form and arrangement of parts.

GRAPTOLITES. 15

it is united at the base for the length of a single cellule. In G. furcatus
the stipes are conjoined for a distance of two or three cellules above
the base.

In G. ramosus, a8 shown in the following figure, the lower part of the
stipe, for a considerable distance, has a range of cellules on each side,
parallel with the axis ; and becoming bifurcate above, it presents two stipes
or branches, each with a single range of cellules. All the species of
this group have a peculiarity in the form of the cellules, which will be
noticed hereafter.

Fig. 20.

Y

GRAPTOLITHUS RAMOSUS.

These species, in their mode of growth alone, present forms which
might be regarded as intermediate between the mowoprionidian and
diprionidian groups; though the typical forms, G. pristis and allied
species, never show any tendency to a division of the parts of the stipe ;
and we shall observe, as we progress, that these forms are connected with
other differences of structure.

Fig. 21.

GRAPTOLITHUS PRISTIS.

The species of this type (Diprion or Diplograptus) are simple linear or

é

16 ; CANADIAN FOSSILS.

sub-linear stipes, bearmg a range of cellules on each side, often showing
an initial pomt orradicle at the base, and an extension of the slender axis
above and beyond the celluliferous portion.

From these forms witha double series of cellules, we pass to the broad
foluform stipes, which are apparently composed of four semi-elliptical
parts conjoimed along their straight sides, and thus present four ranges of
cellules. These forms (Phyllograptus) are, in some species, broad and
short, while others are elongate, with sub-parallel sides, as shown in the
accompanying figures.

[See also plates xv and xvi. ]

Fig. 22.

PHYLLOGRAPTUS AUGUSTIFOLIUS. PHYLLOGRAPTUS TYPUS.:

(See illustrations under generic descrip- a group of separated stipes as they lie upon
tion, and plates xv and xvi.) the surface of the shale.

From the occurrence of a large number of these leaf-like stipes, some-
times crowded together in a small space, I have inferred that they may
have grown as Retiograptus. (Plate xiv, fig. 9.)

Following the forms with a double series of cellules, are those of similar
general form, the Retiolites, which are known only as simple stipes.
(Plate xiv, figs. 1-5.)

In the Retiograptus we have simple elongate stipes; and in one form
(plate xiv, fig. 9) we have the stipes united by slender basal extensions
in a spreading frond, in a manner not unlike some of the graptolites
proper, with the parts in bilateral arrangement.

In the genus Rastrites of Barrande we find a departure from all of
the preceding forms in the slender stipes with delicate ‘slender tubular

GRAPTOLITES. . 17

cellules.* The species of this genus, so far as known, have the cellules
developed on one side only of the:stipes or branches ; though there seems
no reason why we should not have species with cellules upon the two
sides of the axis.

The species for which I have proposed the name Zhamnograptus con-
sist of slender cylindrical stipes and branches, some of them very similar
in general aspect to Rastrites, but the alternating branches are long and
slender, and we have found no appearance of cellules on any part of the
specimens known.

Tn the accompanying illustration the branchlets are given off alternately
on the opposite sides of a stipe or rachis, and the slender solid axis can
be traced from the main stipe into and along the centre of the branchlets.
The analogy between these forms and the celluliferous graptolites of the
preceding illustrations does not appear to be very intimate, but they
occur in the same beds, and the fossil has the same texture and substance.

Fig. 24.

THAMNOGRAPTUS TYPUS.

In the genus Ptilograptus (plate xxi) we have a somewhat analogous
mode of growth, but there is always an aspect or expression of the fossil
which distinguishes it from Zhamnograptus. In one species of Pizlo-
graptus moreover, cell-apertures have been detected on one side of the
branches or pinnulee.

In the Buthograptus we have a form bearing some analogies with the

* See illustration of Rastrites Barrandi under section iii, p. 26, of this introduction,

18 CANADIAN FOSSILS.

preceding, but the rachis is flexible, and is not known to be branched,
while the slender alternating pinnule are flat and simple, as they have
been observed in numerous individuals. ‘The specimen represented is even
less curved than the usual condition of this species in the slaty Trenton
limestone of Wisconsin.

a

Fig. 25.

BUTHOGRAPTUS LAXUS:

enlarged.

Still more obscure, and perhaps remote in its analogies with graptolites,
is the genus Jnocaulis, consisting of flattened scabrous stems, associated
with Dictyonema in the shale of the Niagara formation, which, from their
carbonaceous substance and apparent graptolitic texture, I have referred

to the Graptolitide.

Fig. 26. °

INOCAULIS PLUMULOSA.

GRAPTOLITES. 19

§ I].—THE CENTRAL OR BASAL PORTIONS OF THE GRAPTOLITE.

1. The radicle, or initial point.
2. The funicle, or non-celluliferous connecting portions of the stipe.
3. The central disc.

~ 1. The Radicle, or Initial Point.—In the most simple forms, or those
with two stipes, as shown in all the figures on plate 1, there is a slender
initial process, which I have termed the radicle. This presents a greater
or less development in the different species ; in some being reduced to a
mere pustule, or scarcely perteptible point, while in others it attains
a quarter of an inch or more in length. Although in none of the species
with a single range of cellules does this part show absolute evidence of
having been attached to any other substance at the maturity of the fronds,
yet it is possible that in the earlier period of its growth, the body may
have been temporarily attached at this point to the sea-bottom or to some
object ; though all the evidence is opposed to this view.

In some of the bi-celluliferous forms, and probably in all of them, there
is a somewhat similar extension below the base of the celluliferous portion
of the stipe, though it is usually more slender; but whether this is always
the true initial pomt of the whole body, or whether it is only the broken
point of attachment to a frond, may sometimes admit of doubt. It is con-
spicuous in Phyllograptus typus; and we observe this feature also in
Retiograptus ; but in one species of this we learn that it is only a broken
process of attachment of the individual stipe, which existed as one of the
members of the entire frond, the true initial point of which would be in the
centre of the whole. (Pl. xiv, fig. 9.)

In all the forms of Graptolitidee which appear to have been free, the
initial pomt or radicle is in fact the commencement of the solid avis,
which will be noticed farther on. In those graptolites with two simple
stipes, the little radicle-like process enlarges above, and the stipes,
diverging in opposite directions, are closely united at their bases, and the
cellules begin almost in the axil between the two. (Plate i, figs. 1, 3, 7,
9, and 10.)

2. The Funicle—In the graptolites with four stipes, the condition
appears like that of two individuals of the two-stiped forms, conjomed by
a straight connecting process of greater or less extent, with the radicle
point in the centre, though often obscurely marked. This connecting
process is always destitute of cellules ; and this, with its divisions, I have
termed the funicle. .

In those forms with eight stipes the funicle is twice divided at its two
extremities; and where there is a greater number of simple stipes, it is

20 CANADIAN FOSSILS.

correspondingly subdivided. Neither the central portion, nor any of its
subdivisions, becomes celluliferous ; and these parts are not termed stipes
or branches, according to the views I have entertained. It is only beyond
the last subdivisions of this part of the body, as in G. Logant, that the
celluliferous parts, or the true stipes, commence.

In one of the proper branching forms, however, the cellules begin
immediately beyond the first subdivisions of the funicle, as in the four-
stiped species. (Fig. 27.)

GRapPtoLtitaus Minzsi.

These barren, or non-celluliferous portions of the graptolitie body, are
not otherwise essentially different from other parts of the stipe. In the
absence of cellules they are consequently more cylindrical, and apparently
more solid, asif the test were thicker, and the common canal less developed
than in the other parts of its extent.

3. The Central Dise.—In several of the species having four simple
stipes, in one species with eight, and in another with a larger number of
simple stipes proceeding from a common centre, we find their bases
united by a thickened corneous expansion of the same substance as the
body of the graptolite. This appears to be composed of two laminz,
which, at least in the central portions, are not conjoined, and the space-is
probably occupied by some softer portion of the animal body. (Plates v-ix.)

The substance of the disc sometimes extends along the margins of the
stipes, producing an alation, as in G. alatus. (Pl. vi, fig. 9.)

This arrangement of the parts of the body seems obviously adapted to
give strength and support to the bases of the stipes ; but: beyond this it
probably serves other purposes of the animal economy. In several
specimens of G. bicornis there is a disc or bulb at the base of the stipe,
which, spreading between the two oblique curving processes, envelopes, in
the compressed condition of the specimens, some of the celluliferous part

GRAPTOLITES. - Al

of the stipe at its base. In other specimens we have a crescent-shaped
extension, as if the disc were in process of development, or perhaps of
absorption. Much the larger proportion of the specimens of this species,
however, are destitute of disc or bulb, and have every appearance of
being complete without this appendage.

These aspects of the species are shown on plate A, figs. 18, 15, 16,
and 17.

How far the bulb-like appearance at the base of some of the species of
Dendrograptus may correspond to the disc of G. bicornis, I have not at
this time the means of satisfactory determination.

§ III.—tTHE NATURE AND PARTS OF THE STIPE PROPER.

1. The solid axis.

2. The common canal,

3. The calycles or cellules.

4, Nature and ornaments of the test.

1. The Solid Avis.—All the graptolites proper have been found to be
provided with a slender solid axis,* while this feature has not been satis-
factorily proved in regard to Dictyonema, and to some other forms.

In those species having a single series of cellules, this axis is upon the
back of the stipe, or on the side opposite to the celluliferous margin; and
in the branching forms it follows all the ramifications. In all the speci-
mens where it has been observed, it is a slender cylindrical or flattened
filiform solid body. In some extremely compressed specimens, this axis
appears as a slender elevated ridge along the back of the stipe; and
where the substance of the body has been removed, it leaves a narrow
groove along the margin of the impression.

In the examination of large numbers of specimens of the monoprionidian
species, we have never found the axis prolonged beyond, or denuded of,
the cellules; as shown in G. colonus, by Barrande, in his Graptolites of
Bohemia. (Plate ii, fig. 5, of that memoir.)

In all the specimens where the extremities of the stipes are entire, as
represented in plates i, ii, and iii of this memoir, there is never any
extension of the axis beyond the last partially developed cellule; and
the number of specimens in this condition is considerable.

Tn the graptolites with two series of cellules, the solid axis is very

* In those species with a single series of cellules, M. Barrande has ascertained that
this axis is solid and cylindrical, its diameter not exceeding 4 millimetre, and its struc-
ture apparently fibrous. (Graptolites de Bohéme, page 4.)

B

23 CANADIAN FOSSILS.

frequently seen extending beyond the celluliferous portion of the stipe at
_its outer extremity ; while the radicle appears like the continuation of the
same below the base. ‘The axis thus appears to be the foundation on which
the other parts are erected. In those specimens, however, which present
so great an extension of the solid axis beyond the stipe, the cellules may
have been removed by subsequent causes.

I am able to corroborate to some extent the observations of M. Barrande
in regard to the apparent double character of this axis. In some ex-
tremely compressed specimens it is marked by a longitudinal groove or
line of division ;* while in others, a double impression has been left by
the removal of the substance.

In some specimens, particularly the younger ones, the solid axis has
been seen extending beyond the base of the stipe, as a duplicate process,
exhibiting a character as of a double radicle. In some solid specimens of
one species, where the tube had been filled with calcareous mud, I am
able to detect only a single round point; and a longitudinal section of the
same species presents a slender filiform axis. It may be, however, that
the parts are so minute and so closely united, as to render them undis-
tinguishable.

In another species, with two rows of cellules, and in which the latter
are of very different form from the preceding, the solid axis is a thin flat
apparently double plate, extending across the entire transverse diameter
of the tube, which is more than two-thirds as great as its longer diameter.
The place of the axis is marked by a longitudinal groove on each side,
not in a direct line, but slightly undulating to correspond with the cellules.
M. Barrande conceives that the joining of the two plates of this axis may
leave a very flat intermediate tube ; and in our specimen, there is appa-
rently an extremely narrow space between the two. He farther supposes
that each of these plates, composing the double axis, is separable, by
decomposition, into two lamine, as illustrated in plate ii, fig. 3, of the
work already cited.

The entire appearance of the species (plate A, fig. 10) is that of
two monoprionidian stipes joined together at the back, the line of junction
being indicated by the groove.

In one species of fetiolites there is a strong excentric or sub-exterior
axis, which is nearly direct ; and in the same individual there is another
undulating axis, to which the cell-divisions of one side are attached. In
the Retiolites of the Quebec group, one side of the stipe shows a very
distinct axis, while upon the other side it is very obscure.

In Retiograptus we have a very distinct central axis projecting below

* The aspect presented by the axis, when marked by a longitudinal groove, is pre-
cisely that which a hollow cylindrical body would have if extremely compressed.

GRAPTOLITES. 23

the celluliferous portion of the stipe, and, in one species, uniting in a
funicle, and forming part of a compound form. In another species, the
simple stipes present similar features, showing at one extremity the
duplicate character of the axis.

In Phyllograptus, the central axis is apparently composed of four
slender flat lamin ; but we have had no means of examining this part
of the body in a satisfactory manner.

2. The Common Canal.—lIn all graptolites with a single series of
cellules, there is, between the bases of these cellules proper and the solid
axis on the back of the stipe, a continuous sub-cylindrical space or canal,
which has been occupied by the body of the polyp, from which the buds,
with their calycles forming the cellules, take their origin, and are thrown off
at regular intervals. :

All the specimens which I have examined confirm this view; and in
some of the species where the extremities are apparently entire, we observe
the incipient development of the young cell from the common body. In
those specimens filled or partially filled with the substance of the surround-
ing rock, this canal is easily distinguished ; while in compressed specimens
there is always a flattened space between the bases of the cell-partitions
and the solid axis.

Tn those graptolites with two ranges of cellules, we have apparently a
duplication of those with the single series, the two solid axes being jomed
together, leaving a common canal or body on each side at the base of
each series of cellules. If however the common body were thus divided,
it would be by the solid axis becoming a flattened plate. This appears to
be true of some species (as for example, plate A, fig. 10), while in others
there is only a simple filiform axis visible. In this case, of course, there
is not an entire division in the common canal after the manner of the
other species. ‘This will appear farther on, under the illustrations of the
structure of these bodies.

In Retiolites, the common body occupies the central portion of the stipe,
giving origin to a series of buds on each side, while it is not divided by a
central axis.

In some species the common body seems likewise to have more extensive
functions ; for in such forms as G. divergens and G. gracilis, there is a
long slender rachis, or tubular body, destitute of cellules except at its two
extremities, and apparently consisting of a solid axis and a common canal,
from which originate, at regular intervals, simple small stipes with solid
axis, common canal, and cellules.

This appears to be one step farther in our knowledge of the origin or
mode of development ; but it shows that a stipe or main axis may produce
in one part celluliferous stipes, and in its extremities develop only cellules,
as we see in the continuation of the main axis of G. gracilis and

24 CANADIAN FOSSILS.

G. divergens, where the continuation of this common rachis is marked by
marginal cellules of the same character as those of the lateral stipes.

The common body therefore appears to perform the double function of
developing the buds which elongate into stipes with cellules, and also of
simple cellules; or we may consider the celluliferous extremity of the
rachis, or main axis, as the termination of the reproductive process, or
as analogous to one of the lateral celluliferous stipes. In the Sertula-
rians we have something analogous to this mode of development. Some
of the species have cellules along the common or main trunk, and produce
at intervals branches or branchlets in place of cellules; others have a
common body, or main stem, entirely destitute of cellules, but producing
branches on each side (opposite or alternate, as the case may be), which
branches produce cellules only.

So long as this rachis gives off only celluliferous stipes, it is analogous
to those parts of the simple graptolites which I have termed the funicle,
having within itself the sources of this development of the several parts.
The mode of development differs from that of the branching forms, inas-
much as the branches proper arise from a division of a cell-bearing stipe
or branch, and of course a division of the solid axis and common body.

In Retiograptus, some specimens show the cell-divisions reaching nearly
to the axis, leaving room on each side for a narrow common body or canal ;
while in a species from the Utica slate, which presents one side of an
entire frond, the cell-divisions of the exterior side all reach to the axis,
leaving the common body on the inner or upper side. In a species from
Norman’s Kill, near Albany, there are three parallel ranges of reticu-
lations, with apparently two filiform solid axes, forming the divisions
between the three meshes. This structure probably occupies one side of
the stipe, while the common body may occupy the other side.

In Phyllograptus, the cell-partitions reach very far towards the centre,
and the space left for the common canal is very small. We infer from
the better-preserved specimens that there is a slender common canal at the
base of each range of cellules. These several canals may or may not
communicate with each other.

3. The Calycles or Cellules: their form and mode of development.—
Since a large proportion of the specimens of graptolites which come under
our observation for the purposes of study or otherwise, are fragmentary,
it becomes of much importance to know the general characters of form and
mode of development of the cellules.

In the preceding section it has been shown that the cellules, or the
inhabitants of these cellules, are not independent, but all have their origin
in a common body, which fills the longitudinal canal, and that they remain
in constant connection with the same throughout their existence.

The calycle or cellule is formed by budding from one side of the com-

GRAPTOLITES. a5

mon body, not unlike many of the Sertularians, except that the cellules
are generally close together at their origin.* They are usually more or
less oblique to the direction of the axis, as is clearly indicated by the cell-
partitions ; and the degree of obliquity often indicates specific distinction.
The cellules are for the most part contiguous at their origin, and they
sometimes remain in contact throughout their entire length ; but in the
greater number of species there is a small portion of each one free on one
side towards the aperture. This character is shown in numerous examples.
(Plates i, 11, and i.)

In some forms the cellules are contiguous in their lower portions, while
the entire upper or outer part becomes free, as seen in Gt. Clintonensis
(plate B, figs. 1, 2, and 3); while in one of the bi-celluliferous species _
from Iowa, the cellules are distant from each other at their origin, and the
upper extremity of one scarcely reaches to the base of the next in advance
(plate A, fig. 10) ; and they are therefore not properly in contact in any
part of their length. The same is more emphatically true of Rastrites,
(fig. 27), where there is a large interval between the bases of the cellules,
which are often nearly rectangular to the axis.

Although we regard the cellule as limited by the cell-partitions, yet in
well-preserved specimens there is sometimes a swelling of the test of the
common body below the cellule, indicating an enlargement of the parts at
the bases of the buds. In one species there is an evident undulation of the

axis, corresponding to this enlargement of the parts in the common body.
(Figs. 10 and 11, plate A.)

* The mode of budding and the form and arrangement of the cellules in the Sertula-
rians are shown in the accompanying figures of two species of Sertularia (figs. 1 and 2)
from our own coast. Fig. 3, with a range of cellules on one side only, is a Plumularia.

Fig. 1. Fig. 3.- Fig. 2.

26 CANADIAN FOSSILS.

|

RAstTRITES BARRANDI:

Fig. 28.

natural size, with a portion enlarged. The cellules consist of long slender tubes.

In the diprionidian species, the cellules on the two sides of the stipe
are alternating, so that the bases or the apertures are opposite the space
between two others. This is more especially shown in the enlarged figures
10 and 12, plate A.

In much the larger proportion of species, the body of the graptolite and
the cellules are so extremely compressed, that they appear only as serra-
tures along the margin, with distinct impressed lines marking the cell-
divisions. The exterior margin of these serratures indicates in an approx-
imate degree the outline of the aperture ; and the frequently occurring
mucronate extension at the extremity of the cellule is produced by the
continuation of the cell-partition, or sometimes by an outgrowth from the
margin of the stipe above or below the aperture.

Were the cellules isolated, their prevailing form would be that of an
elliptical tube or sac, the length of which is greater than either of the two
diameters. When they are in juxtaposition, however, the contiguous sides
are flattened, while the lateral or external surfaces are usually more or less
curved, particularly near the aperture. In a larger proportion of the
species, the calycle becomes slightly expanded towards the aperture ; but in
a few examples there is a distinct contraction above the middle, and the
aperture is smaller than the base. Generally, however, the smaller
diameter is just at the junction with the common body, or at the junction
of the cell-walls with the walls of the common canal.

In asingle diprionidian species, where the specimens are not distorted by
pressure, a longitudinal section of the stipe in the direction of its greatest
diameter (plate A, fig. 12), shows the cellules scarcely narrowed at their
origin with the common body; while in a lateral view of the specimen,

GRAPTOLITES. YH

the base of the cellule is seen to be much wider than the orifice. (Plate
A, fig. 10.) :

In many of the species a transverse section of the cellule near the base is
quadrangular, becoming more rounded towards the aperture; and when the
upper part of the cellule is free, the aperture is round or elliptical, and in
some specimens the calycle is elliptical or cylindrical throughout its
entire length: We have examples of the quadrangular cellules in G.
extensus (plate ii, fig. 16) and G. octobrachiatus (plate vii, figs. 5 and
7); as well as in two species of Phyllograptus (plates xv and xv).
Where the cellules are more nearly isolated, they approach more and
more to the cylindrical form. As examples of cellules contracted towards
the aperture, we have Graptolithus priodon, Barrande, and G. Clinton-
ensis, Hall. (Plate B, figs. 1, 2, and 3.)

M. Barrande has remarked that from the circumstance of the partial
or complete isolation of the successive alveoles of the same series, we may
easily conceive that the walls of contact in contiguous cellules should be
double. This fact he has ascertained from decomposing specimens of G.
priodon ; and we have the same evidence in some of our species. In the
cellules of the ordinary mode of development, each one is an independant part
of the organization, and is provided with its individual body and c¢ell-walls,
as if each cellule were isolated. Whenever two of these are in contact,
the cell-walls coalesce as far as the contact continues ; but when becoming
free, the cellule assumes its normal condition. In some specimens of
Phyllograptus we find this evidence of double walls in the cell-partitions.

In G. putillus, illustrated on plate A, figs. 10, 11, and 12, the cell-
walls, although contiguous to and adjoming the walls of the body (and
not free), do not coalesce, but are readily separable without fracturing
their substance.

There are cellules however where the production of the calycle by
budding from the common body is not so obvious. These forms are
like G. bicornis and G. antennarius, where the orifice is a simple trans-
versely-oval aperture in the side of the stipe. In the flattened speci-
men it appears like a rectangular or slightly oblique, semi-oval notch in
the margin. Its true form is perceived only when the cavities of the polyp
have been filled with mineral matter, or when the stipes are flattened ver-
tically agamst the apertures: they then give the form which has been
described as G. scalaris. This form of cellules is shown on plate A, figs.
1 and 2, which are enlarged from a specimen retaining nearly its original
proportions. Just within the limits of the cellules, and extending the entire
length of the stipe, there is a longitudinal depressed line; and along this
line, and running thence almost rectangularly to the outer limits of the
stipe just above the aperture, the cell-partitions join the exterior test, and

project in an extended border or flange.

28 CANADIAN FOSSILS.

In specimens stripped of the test, where the interior has been filled with
stony matter, the cell-partitions present the appearance shown in fig. 3,
plate A; while there is a large central space apparently occupied by the
common body, but without the appearance of a central axis on the exterior
surface. When the surface is ground down to a plane intermediate between
the exterior and the centre, it presents the aspect of fig. 4 ; and when the
cutting is carried to the centre, it gives the characters of fig. 5, the cell-
divisions apparently reaching to the axis.

The general form of this stipe in section (fig. 6) approaches that of
Retiolites, as shown by Barrande and Geinitz; and in the arrangement of
the common body and axis there is a departure from the typical diprioni-
dian forms of Graptolithus. In this transverse section we have a some-
what concavo-convex form, which is narrower on the concave side. There
is a central or sub-central point indicating the filiform solid axis; and on
each side of this are the divisional cell-walls, which produce a shght con-
traction of the exterior walls of the stipe at the inner limit of their attach-
ment. Another section, fig. 7, shows the same features, together with the
remains of two other cell-divisions, neither of which reach to the exterior
walls of the graptolite; and the one on the right hand shows the narrow
extremity just before joining the axis.

These sections, together with numerous other longitudinal, transverse
and oblique sections, compel us to conclude that this graptolite possesses
a filiform central or sub-central apparently solid axis ; and that the cell-
partitions originate from, or are joined to this axis. ‘These cell-partitions
appear to consist of triangular plates, which have an unequally arching or
convex upper surface, and a concave lower surface. ‘This form of cell-
partitions would Jeave the alveoles to communicate at their bases with the
common body on each side.*

In some forms having cellules of this character, as in G. bicornis proper,
there is, in the flattened stipes, an external ridge, as if indicating the june-
tion of the axis with the external walls. But in examples where this axis
extends beyond the celluliferous portion of the stipe, it is compressed,
having the aspect of a flattened cylindrical filiform body. It has no
appearance of haying been flat, or laterally extended within the body of
the stipe.

In the ordinary forms of graptolites the orifice of communication between
the cellules and the common body is eal round, oval, or quadrangular ;

* The cell-partitions in this form of graptolites are represented as they appear to exist
in the solid specimens examined, on plate A, fig. 9; where, curving gently downwards
on their exterior margins from the upper edge of the orifice, they turn more abruptly
towards the axis, while the central portion extends obliquely to the axis, leaving a
broad arch above, which gradually becomes angular as it approaches the axis.

GRAPTOLITES. 29

and this appears to be true of all the species with a single range of cellules,
and also of the ordinary forms of those with two ranges of cellules, where
the common body. is divided by a longitudinal axis.

In Rettolites, where there is no well-marked division limiting the com-
mon body, the union of the cellules with it is not so well defined; nor
does there appear to be in these forms a continuous cell-partition: the
cellules open in a quadrangular aperture, which is a little oblique to the
transverse diameter.

In those graptolites with the simple transversely-oval orifices in the test,
as G. bicornis, the arrangement of the common body and the communica-
tion of the cellules differ from all the other forms. ‘There is an apparent
double communication with the common body, giving not only the usual
bilateral arrangement of the parts generally, but a bilateral arrangement
of the parts in the individual alveoles.

The external orifice of the cellule in graptolites is extremely variable in
form, and in its relative direction to the body of the cellule, and to that of the
general axis. In a large proportion of the species, the aperture is oblique
to the axis of the cellule, a little expanded, and thickened at the margin.
The lower or posterior edge is often prolonged into a mucronate point or
expansion. ‘This feature, combined with the various degrees of curvature
at or near the aperture, produces a great diversity of external expression
in the orifice.

In G. nitidus, plate i, and in G. similis and G'. extensus, plate ii, the
plane of the orifice is nearly rectangular to the axis of the cellule; while
in G. bifidus, G. pennatulus, and others, the margin is produced into a
strong mucronate extension. In G. octobrachiatus the line of the cell-
margin makes an angle of more than 90° with the axis of the cellule.

In mature individuals of G. Clintonensis the upper part of the cellule is
re-curved, and the orifice opens downward nearly at right angles to the
general axis, having a slight spreading and thickening of the border. In
less mature individuals the orifice is apparently angular, and opens upward,
while the plane of the aperture makes less than a right angle with the
direction of the general axis. It would appear that in the progress of
growth the cell-walls are continued, gradually contracting above, and, after
becoming free from the adjacent cellule, form a slender, gradually cury-
ing tube, which in mature individuals has its orifice directed backward.

In Dendrograptus, the form of the orifice and outline of the aperture
present variations similar to those of the simple uniserrate graptolites ;
but some species show modifications in the form of the cellule which do not
accord with the more simple forms. In Dictyonema, the cellules are not
fully known ; the orifices are marked by a prominent mucronate extension,
and apparently simulate the more common forms of graptolites. (Fig. 5,
plate B.)

30 CANADIAN FOSSILS.

In the bi-celluliferous species the compressed specimens present the
plane of the orifice, sometimes rectangular to the general axis, sometimes
with the outer margin a little advanced, makmg an acute angle with the
axis of the cellule, while sometimes the plane of the margin of the aperture
is rectangular to the axis of the cellule, or rarely makes with it an obtuse
angle. ‘The cellules of Retiograptus, which have not yet afforded means
of satisfactory examination, apparently have their orifices nearly rectan-
gular to the general axis of the stipe.

In one of the forms of the bi-celluliferous graptohtes the cellules are
sub-elliptical tubes, with an orifice of corresponding form, without extension
beyond a slight thickening or callosity at the margin of the orifice. The
plane of the cell-aperture in this one makes an obtuse angle with the
direction of the general axis.

In forms like . dicornis the external orifice is transversely oval, with
or without a projection and thickening of the test from the cell-partition
above the orifice, or extension of the test.

4. Ornaments of the Test.—The compressed condition in which the
graptolites usually occur is unfavorable to the preservation of any minute
surface-markings, or ornaments of the test.

In many of the species, fine striz, parallel to the margins of the cell-
apertures, are perceptible, and in the larger number of species this mark-
ing is all that is preserved. There is sometimes a granular appearance
of the surface, but I have not been able to satisfy myself that this is the
actual surface-texture ; it may be a condition induced by mineralization.
In a few examples there is a row of minute pustules at the base of, and
corresponding to the cellules.

The stems and branches of Dendrograptus, Callograptus, and Dietyo-
nema are irregularly striated. In typical species of Retzolites the test
is finely reticulate ; while in the species from the Quebec group, this
texture, if existing, is so fine as not to be readily resolved by an ordinary
lens. The surface however has not the appearance of entire smoothness,
as in most of the ordinary graptolites.

The chief ornaments of these bodies are the mucronate extensions of
the test, usually from the lower margins of the cellules, but sometimes
from the upper margins. In ordinary forms of the species, with single,
and with double ranges of cellules, the mucronate or setiform extensions
are usually from the lower extremity of the cell-aperture, as illustrated in
fig. 29.

In all those forms of which G. bicornis may be regarded as the type,
these processes, when existing, are extensions of the test above the aper-
ture, so far as observed (pl. A, figs. 1, 8, 9); or as in species of the
character of fig. 20, plate A.

In some species, as G. quadrimucronatus (plate xii), there is a

GRAPTOLITES. » a

Fig. 29.

ppt pa tt tbl TALE od
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GRaApPToLitHus WHITFIELDI:

twice enlarged.

mucronate pomt extending from each angle of the cellule ; as also in
G. testis of Barrande ; except that in the eBecuae species these appen-
dages are more rigid.

In Phyllograptus typus and P. ilicifolius, these processes are apparently
the extension of the angles of the cell-partition.

The cellules of Dendrograptus, Callograptus, and Dictyonema some-
times show mucronate extensions from their outer margins. In Retiolites
the cellules sometimes terminate in a plain margin, and in one species the
divisions are extended in short strong mucronate points. (Plate B,
figs. 5 and 21, and plate xvii, fig. 6.)

All the species of Retiograptus have the margins of the stipes gar-
nished with slender mucronate points, corresponding to the cellules, and
extending almost rectangularly to the axis. (Plate xiv, figs. 6-9.)

These ornaments are not always uniformly developed in the same
species, or even in the same individual. In the larger proportion of
specimens of G. ramosus, the margins of the cellules are apparently
plain; but in the cellules of the simple part of the stipe we sometimes
find a rigid mucronate point, prolonged from the upper margin or limit of
the cell-aperture. (Plate A, fig. 20.) In G. seztans, the mucronate
point is half-way between the two cell-apertures.

In specimens of G. sextans, and in some allied forms from the Hudson

3) ile CANADIAN FOSSILS.

——s

River formation at Marsouin, Canada, the stipes and cellules are less -
fully developed than in those of the same species from Norman’s Kill near
Albany, while the mucronate extensions from the cell-apertures are more
conspicuous.

Besides these ornaments, there is on each side of the radicle or initial
point at the base of most of the diprionidian species of graptolites, a
small process, varying in length, and usually directed downwards. These
processes are usually short, but often considerably extended; in some spe-
cies they are very slender, while in others they are strong and rigid.
In G. pristis they are frequently seen as short slender processes; while
in G. bicornis they are rigid, strong, and slightly curving. In G. anten-
narius, a congener of the latter, they are long and slender setiform
appendages. In one species of Retiograptus they are slender setiform
processes, directed downwards.

In no species of Phyllograptus have such appendages been observed ;
nor have they been seen at the bases of the stipes of etiolites.

§ IV.—MODE OF REPRODUCTION AND DEVELOPMENT IN THE GRAPTOLITIDA.

As already remarked, the graptolites proper are now generally referred
by authors to the Radiata; while some forms which I include in the
family have been heretofore regarded as reticulate bryozoans, or as gor-
gonians. ‘The nearest analogues in the recent fauna appear to be among
the group Pennatulide, or in the Sertularide ; but in all these there is
no absolute identity in the mode of development or character of cellules,
so far as my observation has extended.

In nearly all the true bryozoan forms among fossils, we have the means
of tracing the relations and analogies, both in manner of growth and
reproduction, throughout all the successive geological periods, and in the
present fauna. It becomes therefore more difficult to discover such
analogies for the Graptolitide, since the graptolites proper disappear
from existence in the Silurian period; and the latest form of Graptolitidee
(Dictyonema) is not found, so far as now known to me, in American
strata, at a later period than the Hamilton formation or Middle Devonian.
From this cause, the mode of growth and development are not so readily
understood as in those families which can be traced throughout the geo-
logical series, and still find their analogues in the present seas.

In 1858, I laid before the American Association for the Advancement
of Science a notice, with some illustrations of graptolite stipes, bearing
what I then regarded, and do still regard, as the reproductive cells or
ovarian vesicles. These cells first appear as small ovate buds upon the

GRAPTOLITES. 3s

margins, projecting but little beyond the regular cellules, and, becoming
enlarged, form elongated sacs with swollen extremities, which are finally
dehiscent; and then, as I suppose, discharging the ovules or germs, are
gradually absorbed or dissipated.

Although these sacs are distinctly defined, they have scarcely any
apparent substance, except along the lateral margins, which are limited
by a filiform extension resembling the solid axis of a graptolite. There
are likewise numerous fibres of this kind traversing the sacs; and these
sometimes remain attached to the original stipe after the other parts are
separated. In one example, we have conclusive evidence that they are
connected with the solid axis of the parent stipe. The gradations of
development in these sacs may be studied in the figures 6-9, plate B.

In the specimen fig.10 of the same plate the ordinary cellules are removed,
and the fibres are still seen jomed to the axis, showing the origin of the
reproductive sacs. In most specimens bearing these sacs, the cellules of
the stipe are so obscure that the species cannot be determined ; but in
fig. 9 we find them attached to a well-marked stipe of G. Whitfieldi.

This mode of reproduction in the graptolites shows much analogy with
the Hydroidea, and would indicate the sertularians as their nearest
analogues.*

Upon the surfaces of the slate where these bodies occur, there are
numerous graptolitic germs, or young graptolites of extremely minute
proportions, ranging from those where the first indications of their form
can be discovered, through successive stages of development till they
have assumed the determinate characters of the species.

In several examples, these minute germs have been detected near to
and in contact with the reproductive sac ; and in one case, there is but a
hair’s-breadth between one of the fibres of the sac and one of the oblique
processes at the base of the germ. It cannot be said that we have
detected the germ actually within the sac; but the numerous young
individuals lying near them, and upon the surfaces of the same laminz,
offer very good arguments for supposing that they have been thus derived.

The earliest defined form which we observe in the’ young graptolites

*In the recent Sertularia and Campanularia we find ovarian vesicles, in which a
number of ovules may be enclosed in acommon envelope. These vesicles are developed
along the side of a stipe or branch, and the ovules are often arranged along a central
axis, each one communicating with the common axis of the zoophyte. [Jas. J. Lister,
Philosophical Transactions, 1834, pp. 365-388, pl. ix. Cited also by Dana, “ Structure
und Classification of Zoophytes.”]

Prof. McCoy kas stated (British Paleozoic Fossils, p. 4) that he has found near the
base of the cellules of graptolites, a transverse partition or diaphragm, similar to what
may be observed in some sertularians, and which he regards as proving similar rela-
tions; but I have not discovered in any American specimens evidence of such cell-
diaphragms.

34. CANADIAN FOSSILS.

consists of the initial point or radicle; a diverging process of similar
character on each side, but not quite opposite; a longitudinal axis of
greater or less extent; and a sac-like covering, or thin pellicle of grapto-
litic test, which has scarcely assumed the form of cellules, but which is
most extended in the direction of the common body along the solid axis.
This little sac contains the germ of the zoophyte, which, extending itself
as the common body in its canal along the axis, gives origin to the budding
which develops the successive cellules and the gradual building up of the
stipe.

The earliest condition of development is illustrated in fig. 12 of plate B.*
Ata farther stage of development we have the form better defined, as
in fig. 13, where the germ has assumed the general aspect of G. pristis,
the slender lateral processes being rectangular to the axis.

On the left hand of fig. 8, and at the third reproductive sac below the ~
top, there are two germs visible, close to the sac, where the connection
between one of these and the fibre is nearly complete. The same is shown
in the enlarged fig. 11.

In figure 14 we have the germ of another form, which is unequally
developed on the two sides. Figure 15 (represented of the natural
size) appears to be of the same species, having reached a more definite
form. Figure 16 is an oval disc, of which several more or less defined
specimens have been found among the young graptolites, but I have not
been able to trace it to any known mature form.

The specimens figs. 17 and 18 appear to be the young of G. dicornis,
or of a similar form. In one the body is narrow, without marks of cellules,
and the solid axis is not extended above the common body, being prob-
ably broken off. In the other there is a greater expansion of the
common body, but no cellules are visible, and the central portion of the
substance is more dense, while towards the margin it is extremely thin;
the solid axis is extended beyond the stipe, and the lateral oblique pro-
cesses are quite perfect. This germ, with its axis and common body, had
not begun to develop the cell-apertures on its margins, which may be
seen at a later period.

In nearly all the young graptolites there is an extension of the common
body along the axis above the incipient cellules. This is observed in the
figures referred to and in the young of G. ramosus, shown six times
enlarged on plate A, fig. 21.

Although I have found none of the monoprionidian forms with repro-
ductive sacs attached, I have nevertheless observed what appear to be the
young of some of these species, having an aspect similar to the others,

_

* All the specimens of germs or young graptolites are six times enlarged, except
figs. 11 and 17.

GRAPTOLITES. 35

except in carrying the development upon one side only of the solid axis.
An illustration of one of these forms is given in fig. 19, plate B, showing
the base irregularly divided. These forms cannot be referred to any
known mature species.

This mode of development, illustrated in numerous specimens, can be
readily understood in the simple stipes whether of the monoprionidian or
diprionidian character. Admitting that the examples given furnish
‘evidence of the mode of reproduction of the diprionidian forms, or those
of the sub-genus Diplograptus, where we have a range of cellules on each
side of a solid axis, it is easy to perceive how the germ of an analogous
form may develop from its initial point two series of cellules upon a stipe,
where the parts diverge im opposite directions from the common origin or
initial pot. One step farther in this direction will give us the four-stiped
forms, where the germ of the common body, with its additional elements
of subdivision, produces the quadripartite frond; and so onwards, until
we have the numerously-branched fronds and the branching stipes.

Tn all these, the germ in its incipient development will differ very little.
It may consist of the radicle or initial point, with the solid axis, and the
common body, separated into two, four, eight, or an indefinite number of
divisions, each one bearing its solid axis and common canal. These sub-
divisions sometimes all take place near the origin, which is always central ;
and the divisions continue simple throughout, or do not bifurcate after
they commence to develop cellules.

In others the stipes are again divided, and this subdivision is only
limited by the extent of the frond. In all these fronds the parts are always
arranged symmetrically or bilaterally on the two sides of the initial point ;
as has been illustrated in the preceding pages.

Throughout all the monoprionidian forms, or those illustrated on the
first twelve plates of this memoir, we have only modifications of the
simplest form of development shown in the species of plates i and ii. Where
the divisions at the base become more numerous, (and indeed in the four-
stiped species, ) we find a thick corneous test, of the same substance as the
other parts of the graptolite, uniting the bases of the stipes and continuing
along their margins. This plate has a greater or less development, not
always corresponding to the size or extent of the stipes. It is sometimes
absent, apparently from accident, and some of the four-stiped species are
not known to possess it; while it has never been observed in any of the
species where the stipes are properly branched, or divided in the celluli-
ferous parts of their length.

The interior of this corneous disc, previously described as apparently
composed of two plates of the test, has probably been occupied by some
softer substance, which may have been an extension of the common body, or
have had in some degree the character of the common body of the stipe.

386 CANADIAN FOSSILS.

The development of the diprionidian forms, as deduced from the young
graptolites which we find associated with the reproductive cell-bearing
stipes, would show that these forms of graptolites exist as single and
simple independent stipes from the commencement of their growth.
Nevertheless I conceive that both Retiolites and Retiograptus may have
existed in compound fronds, having their origin from a central point not
unlike in the commencement to Graptolithus Logani, but without the
central disc. These fronds were probably concavo-convex, as were the
individual stipes. The solid axis, instead of being central, is placed exter-
nally along the centre of the convex or outer side ; and the cell-divisions
on that side reach to and join it; while on the upper or concave side the
cell-divisions do not reach the centre, leaving a space for the common
body, which has been shown by Barrande and Geinitz to produce a central
longitudinal prominence.

In these forms the mode of development has been similar to that already
explained, the modification being chiefly in the external position of the
axis and the joining of cell-divisions with the axis on one side; leaving
the common body in a somewhat triangular form, from which the alveoles
are developed on either side.

Fig. 30. Fig 31.

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GRAPTOLITHUS PRISTIS:

enlarged. enlarged.

GRAPTOLITES. on

Whether the Phyllograptus existed as simple stipes with four ranges of
cellules, or in a compound arrangement as in Retiograptus, the mode of
development has been similar: either the germ with its initial point
developed a single stipe with four ranges of cellules, or the same elements
first subdivided, and each division gave origin to its stipe through the
common body.

In regard to the development of the cellules in the different parts of
the graptolite, we observe, as a uniform feature, their lesser development
towards the base of the stipe. In all the monoprionidian forms this char-
acter is particularly observable ; and in a few species the earlier cellules
are raised in a scarcely perceptible elevation above the general surface of
the common envelope. Indeed in a few instances it is impossible to ascer-
tain satisfactorily whether these earlier prominences are expanded into
open cellules. As the stipe is extended, they become gradually more and
more prominent, until towards the middle, or oftener perhaps nearer the
distal extremity, their greatest degree of development is reached. In some
species this takes place near the base, and in the more elongated stipes
there is no sensible increase throughout a great part of their length, and
the two margins of the stipe are essentially parallel. ‘Towards the distal
extremity there is a gradual, or often a more abrupt, diminution in the size
of the cellules, and a few of the last ones are much smaller, until the ter-
minal cellule is sometimes seen in a partially developed condition between
the common body and the partition of the preceding cellule.

The same condition of development in the cellules is true of the diprio-
nidian forms, as is shown in some degree in G. pristiniformis, plate xiii,
but more especially in the accompanying figures of G. pristis and G.
Whitfieldi, the last of which shows the higher cellules diminished, so as to
contract the width of the stipe above (figs. 30 and 31, p. 86).

In fetiolites and Retiograptus, the full development of the cellules
takes place below the middle of the length of the stipe, while they are
less developed towards either extremity. In some species of fetiolites,
including one from the Clinton formation, the cellules acquire their greatest
development near the base, and the margins are essentially parallel for the
greater part of their length.

In Phyllograptus, the lesser development of the cellules at the base of
the stipe is a marked feature. They increase rapidly towards the middle ;
and their greatest development is sometimes above and sometimes below the
middle, but im all cases becomes rapidly less towards the apex.

In Dendrograptus, where we have a stout stem without cellules, the
branches usually begin at some distance above the base: and in their
lower part they have scarcely the appearance of being celluliferous ; in
the middle of their extent the cellules become more distinct, and so far as
can be observed they are less developed towards the extremities.

C

(di)
ee)

CANADIAN FOSSILS.

§ V.—MODE OF EXISTENCE.

he numerous individuals of entire or nearly entire fronds illustrated
in this memoir, as well as Jarge numbers of others examined, serve to give
a pretty clear idea of the general form of the true Graptolites, as well
as of their congeners of the same family. Notwithstanding the presence
of the radicle or initial point observable in so many species, it does not
afford evidence of attachment to the sea-bottom or to some other sub-
stance, at least in the mature condition. In all the monoprionidian forms,
however much or little extended the radicle may be, it is always smooth,
and tapering to a pomt. In many of these, and more especially in those
with a central disc, this radicle is reduced to a minute protuberance, and
is often scarcely or not at all perceptible.

The same is essentially true of the greater number of diprionidian
forms examined. In these the solid axis is sometimes extended beyond
the base of the stipe, and terminated as if broken off abruptly ; while
there is often a slender oblique process on each side of the base.

In Retiograptus and Phylloyraptus there is not the same evidence of
completeness at the base of the radicle. The lower termination, when it
can be fully examined, is broken, as if there had been a further continua-
tion of this part, though it exhibits no enlargement. I have inferred that
all these, like the example of Retiograptus eucharis (fig. 9, pl. xiv),
have constituted parts of a similar compound body, and are bué the separ
rated stipes of the frond. If this be true, their mode of existence is not
unlike the other species with compound fronds and a central disc.

In G. bicornis the extension of the solid axis below the base of the stipe
is not always preserved ; but when it is entire, we find two strong, diverging
and slightly curving processes or spines from the base, having smooth
terminations. Sometimes a dise or bulb, of the same substance as the stipe,
extends between these spines, and in the compressed condition envelopes
a few of the lower cellules, as shown in fig. 17, plate A. Some of the
phases presented by the basal extremities of this species are shown in
figs. 18, 15, 16, and 17 of the same plate.

The expansion at the base of this species has the same general appear-
ance as the central dise of G. Logani, G. Headi, and others ; showing that
this sort of development of the substance is not alone characteristic of
those forms having several stipes united at the base. In other examples
this basal expansion is contracted in such a manner as to give a crescent-
form to the lower extremity ; but in all these gradations, the margins of
this part are entire and unbroken.

We have seen that the youngest forms of the diprionidian graptolites,
those which we may suppose had but recently escaped from the reproduc-

GRAPTOLITES. 39

tive sac, are furnished with the minute radicle-like appendage or extension
of the solid axis, as well as the oblique lateral processes like tentacula ;
and the condition of these parts does not seem to have been essentially
changed during any subsequent period of their growth. While the
extension of this slender solid axis does not seem of sufficient strength to
have formed the base of attachment to the sea-bottom, it may have been
sufficient to maintain connection with other parts of a compound frond.

For all those species with a single range of cellules, as well as for some
with a double range, including Retiohtes, Retiograptus, and Phyllograptus,
I conceive that we have already shown a similar plan of development and
a uniform mode of existence; and we are constrained to believe that all
these forms, in their mature condition, were free floating bodies in the
Silurian seas.

In regard to another group including Dendrograptus, Callograptus,
and Dictyonema, as well as one or two other forms, we have some evidence
indicative of a different mode of existence. The stems of Dendrograptus
are enlarged towards their base, and sometimes present a sudden expansion
or bulb, which I have inferred may be the base or root, once attached to
another substance or imbedded in the mud. The general form of the
species conduces to the belief that they were fixed to the sea-bottom,
though possibly this basal expansion may have resembled that of Graptol-
thus bicornis. In most of the species described, the lower a is
imperfect, and its termination unknown.

Tn those which I have termed Callograptus, the bases of the fronds are
imperfect, but indicate, according to analogy, a radicle or point of attach-
ment like Dendrograptus. In the more nearly entire forms of Dictyonema
known, we have not been able to observe the base; but from their simi-
larity in form and mode of growth to Fenestella and Retepora, we have
inferred their attachment either to the sea-bottom or to foreign bodies.

Nearly all these forms occur in rocks where there are few of the larger
fossils of any kind except the graptolites; so that there is little chance
of finding their bases attached to shells and corals, as we do those of the
bryozoans, even if they had thus existed, The Dictyoneme of the
Niagara, Upper Helderberg, and. Hamilton groups do occur in strata which
contain large numbers of other fossils ;. but we have no evidence of their
having been attached. It is only from their general form therefore, and
from their analogy with other bodies, that we infer that these genera may
have been attached to the sea-bottom or to some objects during their
growth.

_ We admit therefore that the family of Graptolitidz, as now dstertioal
may include both free and fixed forms.

40 CANADIAN FOSSILS.

§ VI.—GENERAL CHARACTERS OF THE FAMILY OF GRAPTOLITIDH; WITH
REFERENCE TO THE DISTINCTIVE FEATURES OF THE GENERA, AS KNOWN
IN THE GEOLOGICAL FORMATIONS OF CANADA AND THE UNITED
STATES.

In the first section of this memoir, I have remarked upon the nature
and general form of the graptolites proper, and the allied genera which I
regard as belonging to the same family. The large accession to the
number of species, and the great variety of new forms added to those
formerly known, require an extension of the characters heretofore given.

The numerous graptolites described by Nilsson, Hisinger, Bronn,
Murchison, Hichwald, Portlock, Geinitz, Barrande, Suess, McCoy, Salter,
Harkness, Nicol, Meneghini, myself, and others, were for the most part ina
fragmentary condition, affording knowledge only of the simple stipe, the
structure of its parts, and the arrangement of the cellules. From these
fragments however we have derived the generic characters; while the modi-
fications in form, and the order and relations of cellules, have furnished
means of specific distinction in the greater proportion of those described.

In maintaining the generic term Graptolithus for the forms which have
the nearest relations with those to which the term was originally applied
by Linnzus, M. Barrande has proposed two sub-genera, characterized
by the presence of a single series, or of two parallel series of cellules,
under the names of Monoprion and Diprion. The latter term haying
been applied to a genus of insects, the name Diplograptus* of McCoy has
generally been adopted.

The distinction indicated would at one time have expressed a character
perfectly trenchant ; but the discovery of such forms as G. ramosus ¢ and
G. furcatus, shows the occurrence of both a single and a double series of
cellules upon the same stipe, or, more properly, shows the basal portion
consisting of a stipe, with two parallel ranges of cellules. The stipe, dividmg
at some distance above its origin, is continued as two simple stipes, each
with a single range of cellules. These cellules are on the outer margin,
and are a continuation without interruption from those of the lower part
of the stipe. Including these therefore in the same group with G. pristis,
the subdivision indicated would have less value for the purposes of study ;
but I believe these latter forms may be separated on other grounds, as will
be shown farther on; so that with our present knowledge we may still

* In the genera proposed by myself, I have chosen the termination grapius instead of
grapsus, since the latter termination is in use in the nomenclature of crustacea.

+ The subdivision of this species beyond the first bifurcation, represented in the Pale-
ontology of New York, vol. i, pl. Ixxiii, fig. 3, is erroneous; the specimen consists
of two individuals, the base of one being placed directly in the axil of the other.

GRAPTOLITES. 41

recognize Diprion, = Diplograptus, as a well-marked and clearly-defined
sub-generic group of the Graptolithus proper, having such forms as
G. pristis among the typical species.

Mr. Geinitz has more recently proposed the name Monograptus to
include Monoprion and Rastrites of Barrande ; placing under this genus,
as his typical species, G. sagittarius of Hisinger, which is the typical form
of Graptolithus of Linneeus.

The genus Cladograptus* is also proposed by Mr. Geinitz, to include
the species G. ramosus and G. furcatus, Hall, G. Murchisoni, Beck,
G. serra, Brong., G. Forchhammeri, Geinitz, and G. sextans and G.. serra-
tulus, Hall. At the same time the British paleeontologists, adopting the
name Didymograptus, McCoy, place under that genus G. Murchisoni,
Beck, G. caduceus, Salter, G. sextans, Hall, G. geminus, Hisinger,
G. hirundo, Salter, and other similar forms. Those which are made the
typical forms of the genus by Geinitz are the “species gemelle” of
Bronn, who included under that term the G. geminus, Hisinger, and
G. Murchisoni, Beck, which are by no means nearly related to G. ramosus
or G. furcatus. The first-named two species, which were the earliest
known of that character, and regarded as the typical forms of Didymo-
graptus, are similar to G. bifidus and G. extenuatus of this memoir,
which differ from the other species on plates i, ii, and ii, only in the
lesser divergence of the stipes.

Very recently Mr. Salter has proposed a further subdivision of the
graptolites under the name Jetragraptus, ‘a kind of double Didymograp-
tus,’ of which G. bryonoides is made the typical species ; and G. quad-
ribrachiatus is referred to the same genus. He also proposes Dichograp-
tus for those having the “fronds repeatedly dichotomous from a short
basal stipe mto eight, sixteen, twenty-four, or more branches, each with
a single row of cells.”’ “ But the main character which distinguishes
Dichograptus is the presence of a corneous plate | which envelopes
all the lower part of the branches, and which is not known in any other
genus of the group; it has not indeed been seen in more than two or
three species of Dichograptus, but it may not in all cases have been pre-
served.’

These subdivisions may be of some value when the entire frond and all
its appendages are preserved, but unfortunately this is rarely so; and
when we have but fragments of the stipes or branches, there is no force

* CuapoGRApsus, Geinitz. Syn. Graptolithus auctorum ; species gemelle, Bronn. (Die
Versteinerungen der Grauwacken formation in Sachsen, etc. Heft. i, Graptolithen, p.29.)
Monocrapsvs, id., ibid., p. 42. Syn. Monoprion et Rastrites, Barrande; Graptolithus,
Suess.

{ First discovered in the graptolites of the Quebec group at Point Lévis.

t Quarterly Journal of the Geological Society, vol. xix, p. 136.

42 CANADIAN FOSSILS.

or value in the application of these terms: we are thus reduced to the
necessity of adopting the old term Graptolithus. Again, the value of
Didymograptus I conceive to be pretty well illustrated in the case of
G. caduceus, the original of which is cited from Lauzon, Canada.* After
studying the large collections of graptolites made by the Canadian Geo-
logical Survey, I am compelled to believe that the G. caduceus was
founded upon such forms as I have represented on plate xvi, figs. 22, 23,
and 24 ; for we have no two-stiped species or forms of “‘ Didymograptus”’
with a pedicle or radicle so long as that represented in the figures of
Mr. Salter, nor any one so abruptly recurved; and I regard the apparent
radicle in the two examples figured as simply one of the four stipes
imbedded in the shale, and exhibiting its non-celluliferous margin and a
small portion of its width, as I have shown in the figures cited.

Other varieties of this form show only the two simple stipes, with a
slight process in the centre. We have therefore a “‘ Zetragraptus” na
condition undistinguishable from a ‘* Didymograptus’’; and the same may
happen in G. bryonoides, as shown in plate iv, fig. 5, where the quadri-
partite stipe is separated into two; and in the separated stipes it is mpos-
sible to know if there have been two, four, or eight in the entire indi-
‘idual. With regard to those fronds which are repeatedly dichotomous,
forming the genus Dichograptus, of which the distinguishing character is
the central ‘‘ corneous plate which envelopes all the lower part of the
branches,’ we may remark, that we have three or four species of the
four-stiped form, or “* Zetragraptus” with the central corneous plate ; while
we have four species which are not known to possess it. Of the two
eight-stiped species known, one has the central corneous plate or dise,
and the other was probably destitute of such an appendage. In
G. Logani, with its numerous simple stipes, the central corneous plate
is usually present, though not in all examples; while G. multefasciatus,
with more numerous simple stipes than G. Logani, is not known to
have a central corneous disc, and, from its mode of growth, probably
never possessed such an appendage. From the irregularity of growth in
the G. abnormis, I infer that there was no central plate.

In all the properly-branching species where the initial point is known,
as in G. flexilis, G. rigidus, and G. Milesi, no such central plate has
ever been seen; nor has it been shown in any European species, so far as
I know. The frequently-bifurcating stipes, similar to the one originally
proposed by Mr. Salter}t as the type of Dichograptus, are not known to
possess the central corneous disc.

Although entirely willing to accept and adopt such subdivisions of the
graptolites as will aid in determining their zoological character and

‘

* Graptolithus caduceus, Salter; Quarterly Journal of the Geol. Society, vol. ix.
} Geologist, vol. iv, p. 74, 1861.

GRAPTOLITES. | AS

relations, their geological value, or indications of differences in mode of
development, I do not appreciate at the present time the force and value
of the proposed generic subdivisions for the two, four, and eight-stiped
species, or the presence or absence of a central corneous disc as indicating
generic distinctions; since it is impossible to obtaim any aid from such
designations for the references of the numerous fragments which are the
ordinary form and condition in which we find the graptolites, and in which
they must generally be studied.

The form, mode of growth, and arrangement of cellules im all these
several proposed genera, are so identical in plan as to afford no means for
generic separation ; and although the same is true of the properly-ramose
forms, yet I conceive it might have been convenient to adopt a term
(Dichograptus or Cladograptus) indicating the ramose character of the
stipes, regarding as true branches only the subdivisions which take place
after the commencement of the cellules.

The genus Wereograptus* of Geinitz, proposed by that author to include
such forms as Wereites, Myrianites, and Nemertites of Murchison, and
Nemapodia of Emmons, etc., can scarcely be admitted mto the family of
Graptolitidse, since all the American species referred to the first three
named genera have no texture or structure like graptolites, and (as I
have elsewhere shown) appear to be referable to the tracks or trails of
some marine worms or other animals upon the sea-bottom ; while MVema-
podia is simply the trail of an existing slug upon the slightly lichen-covered
surfaces of the slates.+

The genus Glossograptus of Emmons is founded upon a species of
Diplograptus with ciliate appendages on the cell-margins ; and no char-
acters are given to show its generic distinction. The typical species
of Nemagraptus (NV. elegans) is apparently a part of an individual of
Graptolithus gracilis, or of some similar species; while the relations of
the second species of the genus (JV. capzllaris), an elongate, flexuous,
filiform body with afew branches at irregular intervals, can scarcely be
determined from the figure given.

The typical and only species of Staurograptus t of the same author is
a very remarkable form of extremely minute proportions. Its mode of
growth and subdivision of stipes, if accurately represented in the figure,
are unlike anything known among this family of fossils, and it merits
generic distinction.

* Nereograpsus: Die Verstein. Grauwacken formation, etc., Graptolithen, p. 27.

+ These markings can be easily removed from the surface of the laminee by washing with
water; and they can be traced over the exposed surfaces of the edges of the successive
lamine.

t Glossograpsus, Staurograpsus, Nemagrapsus: Emmons, American Geology, part ii,
pages 108 and 109,

44 CANADIAN FOSSILS.

The term Diplograptus is properly applied to such forms as Graptoli-
thus pristis, Hismger, G. palmeus, Barrande (excepting figs. 5 and 6),
G. foliaceus, Murchison, and G. pristiniformis of this memoir; where the
cellules are disposed in parallel ranges on the two sides of the central
axis, and are of the same or similar form and arrangement with those of
monoprionidian form G. sagzttarius, and with others of that type, in which
we include all the species of the first nine plates of this memoir ; the reason
for the proposed separation being in the double range of cellules only.

In the ordinary forms of Diplograptus (plate xiii, figs. 15-17), as in the
ordinary monoprionidian types, the cellules are usually closely arranged,
and overlapping each other for a part of their length. In a single species
CG. putillus, from the Hudson River formation in Iowa), which has
come under my observation in some well-preserved fragments, we have
so far a modification of the general arrangement of the cellules that
the apex of one barely reaches the base of the next succecding. The
stipe is a strong elliptical tube with a flattened central solid axis, the
line of which is marked on the exterior by a longitudinal undulating
groove (fig. 10, pl. A). The surface is strongly striated transversely,
and the sides studded with tubular cellules, which are alternately arranged.
These cellules are sub-oval, flattened on the side adjoming the body
of the graptolite, curving on the exterior free portion, and obliquely flat-
tened at the base just above the aperture of the cellule next below, as
shown in the profile view (fig. 11, plate A). The exterior test of the
common body is swollen in oblique undulations in the direction of the base
of the cellules, or where the individual buds take their origin; and the
axis is curved towards the opposite side, as shown in fig. 10, plate A.

The transverse diameter of the stipe is about two-thirds as great as the
longer diameter. The celluliferous face of the stipe shows broad elliptical
depressions ; the lower side, for little more than half the height, being the sub-
oval cell-aperture ; while the upper part is the semi-oval flattened area at
the base of the next succeeding cellule, as shown in fig. 11, plate A. In
this case the cellules are shown to be separate and distinct tubes, closely
pressed against the lateral walls of the stipe on one side, and communica-
ting with the common canal by a slightly narrowed passage, as shown in
figure 12, plate A, which represents a longitudinal section of the body.
In a transverse direction the base of the cellule is wider than the aperture
Cig: dd, spl. A):

Specimens of this character, on becoming flattened, would present a form
where the cellules, though inclined against the common body, would not
overlap each other, and where the margin of the cellule is directed
backward instead of forward. Were these cellules to be prolonged, they
would overlap the next in advance, presenting in this condition but a slight
modification of the usual forms of Diplograptus. These deviations from

GRAPTOLITES. 45

typical forms are so slight as to offer no sufficient ground for generic
separation.

There are however a few examples, where the stipe is marked by a
range of cellules upon each side of the central axis, which appear to be
properly separated from Diplograptus, on account of the form and structure
of the cellules. These are apparently quite unlike those of G. pristis, and
others of that sub-genus. The Graptolithus bicornis, and two or three
allied forms, when flattened in the shale, show, as already described, a
simple semi-elliptical notch in the margin of the stipe, nearly rectangular
to the axis. This is well shown in fig. 3, plate vi, of M. Rarrande’s
memoir, and also in Mr. Salter’s illustrations of Graptolithus teretiusculus
of Hisinger.* It is represented, less perfectly, in the figures of Prof.
Harkness,j and in most of my own figures on plate lxxii of the first
volume of the Paleontology of New-York. When compressed rectangularly
to the cellules, the apertures are transversely oblong-oval ; and the same
form is shown when looking upon the celluliferous margin of an uncom-
pressed stipe.

The structure of these stipes and their cellules has already been
described in a preceding section, with reference to the figures illustrating
the same. The G. bicornis, renin im New-York and Canada, may be
considered the type cf a group of species of which we have two in the
shales of Norman’s Kill near Albany, one in Ohio, and a similar or identical
form in the Utica slate at Collingwood in Canada West. I would include
in the same group figs. 5 and 6 of plate iii, as well as figs. 7, 8, and 15,
plate 11 of M. Barrande’s Memoir; Graptolithus teretiusculus of Hisinger ;
and those referred to the same species by Salter.t The Diplograptus
rectangularis of McCoy |] is of the same type, as also figs. 1, 5, 10,
11, 12, etc., tab. ii, of Geinitz (Graptolithen) ; and I conceive that

many, if not all of the scalariform specimens, belong to species of this
character.

The Graptolithus ramosus has usually been arranged by authors under
Diplograptus ; the lower part of the stipe having a double range of
cellules, while it is bifurcated above, with the cellules on the outer margin
of each division, as already described; and a simple explanation of this
condition has been offered by supposing that the solid axis has been
separated after the death of the zoophyte. This however will scarcely
afford a satisfactory argument when we find that all the specimens are in
the same condition ; that usually the division begins at a uniform distance
from the base ; and that, when entire, the divided portion much exceeds the

* Quarterly Journal of the Geol. Society of London, vol. viii, pl. xxi, figs. 3 and 4.
{ Id. Ibid., vol. vii, pl. i, fig. 11.

ft Quarterly Journal of the Geological Society, vol. viii, pl. xxi.

|| British Paleeozoic Fossils, page 8, pl. xiii, figs. 8, 9, and 10.

46 CANADIAN FOSSILS.

simple undivided part of the stipe. Moreover, the species is recognized
in this condition m the Hudson River formation in Canada, and has like-
wise been recognized in Great Britain ; while a similar or identical form
has-been shown by Prof. McCoy to occur in Australia. We must there-
fore seek some other than an accidental cause for the explanation of this
uniform bifurcation of the stipes of that species. In the meantime, it
appears to me highly proper to suggest its separation from Diplograptus.

On farther comparison, we shall find that G'. ramosus is not quite alone
in its peculiar characters. In G. furcatus there are a few cellules at the
base of a simple stipe below its bifurcation ; and in G. sextans, the lower
part of the stipe is simple, the division taking place above the first cellule ;
but in entire individuals the division is never from the initial point, as we
see it in G. bifidus and G. nitidus of this memoir.

Now these first-named species, as well as G. ramosus, have cellules of a
peculiar form ; and looking still farther, we find a similar form of cellule in
G. Lorchhammert, Geinitz, and G. divaricatus, Hall, two species which are
divided from the base, having a single range of cellules upon the outer
sides of the stipe. I believe it will be found, moreover, that all the
graptolites with cellules on the lower side of the stipes (in reference to
the initial point or radicle) have these parts of the same form as G. ramosus,
and very unlike the G. pristis and allied species. Nor are the cellules
on the simple or divided portions of the same stipe, or on those which are
entirely divided and upon the lower side, at all like the cellules of G. priodon, -
G. geminus, G. Murchison, or any of the allied forms illustrated in this
memoir, to which the term Didymograptus has been applied ; nor can they
be properly united with them. ‘The form of the cellules is always suffi-
ciently distinctive even in fragments of the stipes; and this feature, together
with the mode of development or growth, seems to me sufficient to sustam a
generic distinction.

The genus /tetiolites is described by M. Barrande as having no central
solid axis, but with a single internal canal occupying the median portion
of the polyp. The prevailing form of the stipe is somewhat concayvo-
convex, with the centre of the concave side prominent; the entire surface.
is covered by a net-work of corneous substance, and the cell-apertures
are quadrangular.

Prof. Geinitz has given some further illustrations, showing more em-
phatically a longitudinal axis on the convex side, to which are joined the
ceell-partitions ; while he regards the common body as occupying the
prominent central portion of the concave face of the stipe, and shows
the cell-partitions terminating before reaching the centre, leaving a space
occupied by the width of the common body. This he represents as covered
by a net-work of slightly different texture from that of the other portions
of the substance.

GRAPTOLITES. 47

The Canadian specimens which I have referred to this genus are so
extremely attenuated that it is impossible to determine the details of
structure, and the surface-characters are obscure. ‘Thus far we have
no American specimens in a condition to afford the means of elucidating
some obscurities which seem to me still to exist in regard to the intimate
structure of this genus. The species of the Clinton formation is extremely
compressed ; and while some specimens show the cell-divisions termmating
at a distance from the centre, yet, after protracted and repeated exami-
nations, my most critical observations result in showing only the struc-
ture which is illustrated on plate B, figs. 20 and 21.

On one side we have an external, cylindrical, solid axis, to which the

cell-divisions are joied; but these latter show only filiform cylindroid -
processes, extending from the axis to the cell-margin, and projecting a
little beyond the margin of the stipe. The only other aspect which we
observe in this species is that of an undulating or zigzag filiform axis on
the opposite side, to which the cell-partitions are joined, as in fig. 21,
plate B. We know this to be on the opposite side or within the stipe, as
it is sometimes seen overlying the straight axis and cell-partitions.
_ At the junction of the cell-divisions with the zigzag axis there are other
processes of similar character, projecting upward and outward from the
‘axis, all of nearly equal length, but apparently broken at their extremi-
ties. J have not been able to determine any connection between these
and other parts of the skeleton, but we have the two structures very
clearly represented in the figures referred to. I have supposed that
similar processes may have extended to the opposite side, from the junc-
tion of the cell-partitions with this undulating axis, either joining the
cell-divisions or the straight axis; but after long mvestigation I have been
unable to find satisfactory evidence of such connection. The cell-apertures
are surrounded by thickened margins, and the only appearances of cell-
partitions are the sub-external cylindrical extensions from the aperture to
the axis. Neither the species of the Quebec group nor that of the Clinton
formation, in any of the specimens seen, are in a condition to show
evidence of the concavo-convex character of the stipe represented by
M. Barrande and Prof. Geinitz.

The species of Retograptus, while having some characters in common
with Ketiolites, do not possess the reticulated structure of the test in either
of the described species. There yet remains some obscurity in regard
to the internal structure of this genus, which can only be satisfactorily
explained by the examination of better-preserved specimens. Neverthe-
less, in its general form, structure, and mode of growth, it is shown to be
quite distinct from other graptolitic genera. The three species referred
to this genus present differences which can only be reconciled by supposing
that the two sides of the stipe are very unlike each other in form and
external characters, as in [etiolites. -

48 CANADIAN FOSSILS.

The species for which I have proposed the genus Phyllograptus, pre-
sent close analogies with the typical form of Diplograptus in the character
of test and form of cellules. These, in their aperture and form, are nearly
quadrangular; and the cell-partitions are apparently continuous between
the cellules, and reach nearly to the central axis ; characters which we find
in Diplograptus. These forms, in their great lateral extension, depart
widely from their analogues; but they differ more essentially in their
cruciform mode of growth, presenting an arrangement of parts, as if four
simple stipes (like those of G. bryonoides or G. Bigsbyi) were joined
together by the coalescing of the solid axes. In this latter respect, and
in their great development in width, they differ most essentially from
all the other genera of this family of fossils. ‘These forms are fully
illustrated on plates xv and xvi of this memoir.

In the typical species of Dendrograptus, as illustrated under the generic
description, and in some of the species on plate xvii, we have a wide
departure from the typical forms of Graptholithus, as developed in the
characteristic species of the genus (plates i-ix). The strong stem or
trunk, which is free from cellules, and which has apparently been fixed
at the base; the irregular branching, which has no bilateral, and apparently
no definite arrangement, such as observed in all the forms of tree Grap-
tolithus, are strong points of dissimilarity, and furnish characters for
generic distinction. The stem and branches are unequally striated longi-
tudinally, but the form of the celluliferous branches and of the cellules
offers no important difference (except in the smaller dimensions) from
those of the stipes or branches of the usual form of graptolites with a
single series of cellules. In one species referred to this genus (the
D. gracilis) there is some departure from the typical form of cellules,
and the body of the stipe is contracted at intervals, while the form of
cellule and cell-aperture is not unlike some of the Sertularians.

The genus Callograptus offers forms which are intermediate between
true Dendrograptus and Dictyonema. In these species, the forms of the
cellules have not been fully determined. ‘They are marked in one species
by slight oval pustules, or oval depressions, upon the extremely compressed
surface of the stipe; but it cannot be satisfactorily shown that this appear-
ance indicates the normal condition of the cellule or the aperture. If the
true form be in reality so far different from the usual character of the
Graptolitidee as these appearances indicate, it may be found necessary to
separate them from this family.

The genus Dictyonema is restricted to such forms as have the numerous
stipes and branches connected by a transverse process, and the whole
united in a flabelliform or funnel-shaped frond, without elongate stem or
trunk. The stipes and branches are irregularly striated externally, con-
sisting of a corneous envelope, as in ordinary graptolites; but I have not

GRAPTOLITES. 49

been able to determine clearly the existence of a solid axis. The cellules
are indicated by angular processes or cell-denticles on the inner side of
the branches ; as shown in fig. 5 of plate B.

In the genus Rastrites of Barrande the distinguishing features are the
slender cylindrical stipes or branches, with distant slender tubular cellules.

The few species of Zhamnograptus known consist of cylindrical or sub-
cylindrical stipes, with slender elongate alternating pinnulz or branchlets.
No evidence of cellules has been observed in any a the specimens.

The peculiar forms for which I have proposed the name Ptilograptus,
consist of branching stems, which, in all their divisions, are studded on
each side, in alternating order, with narrow pinnule. These are some-
times extremely slender, or even capillary in their dimensions. In one
species I have detected elliptical spots upon one face of the pinnule,
which are slightly flattened, and I infer that these are the cell-apertures.
The substance of the test is corneous, and there is an internal solid axis.
Although I have placed these forms under the Graptolitide with some
hesitation, the form of cellules may perhaps render a separation desirable ;
but with only our present information, such a separation cannot at this
time be made.

The genus Jnocaulis was proposed for some flattened stipes with a scab-
rous surface, which have the appearance of denticles upon the margins.
These stipes grow in close groups or tufts, and are bifurcating or branched
in their upper portions. No positive evidence of cellules has been observed.
The presence of denticles, together with a corneous or carbonaceous sub-
stance, have induced me to place this fossil among the Graptolitide.

There is still another form known, which may be doubtfully classed
among the Graptolitide. It consists of a slender flexible median rachis,
on each side of which are placed, in alternating order, slender flattened
pinnulz, which are of nearly equal width inomeboe and are themselves
flexuous. Upon one side of the rachis are minute points or dots, which
have apparently been the cell-apertures. The test is a black corneous
or carbonaceous substance, but there is no evidence of a solid central axis.
These bodies are numerous in some shaly beds of the age of the Trenton
limestone, at Plattville, Wisconsin. For these I have proposed the name
of Buthograptus.*

Associated with the preceding forms, there are some stems of corneous
or carbonaceous texture, frequently branched, the branches again dividing,
and sometimes, if not always, in whorls; in one of which six divisions
were counted. The general form of the body is not unlike that of Den-
drograptus, but the branches are more slender, and ramify in a different
manner, while there are no visible cellules. ‘Without farther knowledge,

* Report of Progress of the Geological Survey of Wisconsin for 1860, p. 19; commu-
nicated January Ist, 1861.

50 CANADIAN FOSSILS.

I refer these fossils, with hesitation, to the genus Oldhamia ( O. fruticosa,

Hall).

The variety of form and mode of development among the graptolites
is shown, by these collections from the Quebec group, to be much greater
than had ever before been supposed. ‘The number of species which have
been traced to their origin, and whose mode of growth has been verified,
is probably larger than in all the collections heretofore made ; and, together
with those before known, enables us to give a very full exposition of the
characters of this family of fossils.

SYNOPSIS OF THE GENERA OF GRAPTOLITIDA.

Te

Species consisting of stipes or fronds, with a bilateral arrangement of the parts ;
a solid axis, with a common canal extending along each series of cellules,

1. The successive buds developed in tubular cellules,
which are usually in contact for a greater or less pro-
portion of their length, and inclined towards the axis.

a. Cellules in single series along one side of a com-
mon solid axis. Stipes, two or more, from a com-
mon’ origin, with or without a central disc. Sub-
genera Monoprion,* Didymograptus, Monograptus,
Tetragraptus, ete.

. Cellules on one side of slender branches, which
are developed on one or two sides of a long slender
axis or rachis, the free. extremities of which are
likewise celluliferous. Hx. G. gracilis and G. diver-
gens. |

c. Cellules developed in aie arrangement on two |

ao

GRAPTOLITHUS, Linneus.

sides of a common solid axis. Stipes narrow elon-
gate. Sub-genus Diprion, = Diplograptus.

d. Cellules developed in a cruciform arrangement on
the four sides of a common or coalescent axis.
Stipes elliptical or sub-elliptical.

Puytiograptus, Hall,

2. Cell-apertures excavated in the margins of the stipes,
without tubular or cup-form extension; the cell-
apertures upon one or both sides of the stipe.
Graptolithus bicornis and others.

Cumacograptus, Hall.

3. Solid axis eccentric or sub-exterior, with cellules de-
veloped in parallel ranges on opposite sides of the
stipe, and in contact throughout their entire length.

a. Known only as separate stipes, with reticulate
test.

b. Occurring as simple stipes, and as compound
fronds; test smooth.

} Retiotites, Barrande.
} Retiogrartvus, Hall.
* Should it be proved that there exist simple stipes with a single range of cellules,

the definition of this section will require to be modified, or a new sub-section made to
include such forms.

GRAPTOLITES. 51

Il.

Species having a common trunk or stem, or growing in sessile groups of stipes from

a common origin, without distinct bilateral arrangement of the parts. Cellules in single
series on one side of the stipes or branches, and arranged along a common canal or axis.
1. Branches free (i. e. not connected by transverse bars;)

cellules in contact or closely arranged. } Denprograptus, Hall.

bo

. Branches unfrequently and irregularly connected by

CALLOGR ph
transverse processes. } craptus, Halé

OO

. Stipes and branches more or less regularly united in a

reticulate frond, without elongate stem. | Dictyonema, Hall.

4, Stipes round or flattened, growing in groups, and bifur-
cating above; margins denticulate; surface rough or

: Inocautis, Hall.
scaly. [The relations of this genus are not fully deter- om ,

mined. |
III.
Slender cylindrical branches, with tubular cellules arranged in single (or in double 1)
series. Cellules not in contact in any part of their length. Rastrites, Barrande.
Iv.
Species having a common axis or rachis, with slender lateral alternating branchlets,
Cellules unknown. THAMNOGRAPTUS, Hall,
Vie

Species having a common axis, more or less frequently bifurcating, with pinnule
closely and alternately arranged on the opposite sides; cell-apertures on one face of
the pinnule. Prinograptus, Hall.

VI.

A simple flexuous rachis, with slender flexuous flattened pinnule arranged in alter-

nating order at close and regular intervals on the two sides. Cell-apertures unknown,

or circular. Burnoeraptus, Hall. ,
VII.
Strong stems, which are numerously branched. Branches and branchlets slender,
arranged in whorls. Cellules undetermined. OupHamia [7], Forbes.

§ VII.— GEOLOGICAL AND GEOGRAPHICAL DISTRIBUTION OF THE GRAPTO-
LITES IN THE ROCKS OF CANADA AND THE UNITED STATES.

Until the remarkable discovery of the graptolites of Point Lévis in
1854, the chief repository of these fossils known in American rocks was
in the shales of the Hudson River valley.

The position assigned to the rocks of the-udson River valley was the
superior part of the lower division of the Silurian system. In this respect,
the horizon of the Graptolite beds corresponded with those of Ireland,
from which these fossils had been described by General Portlock ;* and
with the position assigned to those in Sweden, as well as with those of the

* Geological Report on Londonderry, etc., page 317-322.

52 CANADIAN FOSSILS.

Llandeilo and Caradoc formations of Great Britain. The graptolites of
Bohemia are from strata referred by M. Barrande to the base of the
superior division of the Silurian system; and those of Saxony were
regarded as from the same horizon.

In 1850, M. Barrande expressed the opinion that the epoch of the
graptolites was posterior to that of the “ Faune Primordiale”’ in Bohe-
mia and Scandinavia; while their association with primordial fossils in
the Malvern Hills and at Snowdon, indicated the earlier appearance of
these zoophytes in Great Britam. A comparison of all the published
information on the subject at that time induced M. Barrande to conclude,
as a general fact, that the graptolites had made their earliest appearance
in the regions of the northwest; and that their highest development in
central Europe had only been reached at a later period, or at the base of
the upper division of the Silurian system.

The investigations in the Geological Survey of New-York had proved
in a pretty satisfactory manner that no graptolites proper occurred above
the horizon of the Clinton group, though Dictyonema (supposed to belong
to the same family) had been found in the Niagara formation. The species
at that time known ranged from the higher strata of the Lower Silurian,
to the lower beds of the Upper Silurian division; and both in Europe and
America, these fossils were regarded as of eminently Silurian character,
and unknown in any later geological periods.

The discovery of a graptolitic species in the Potsdam sandstone of the
St. Croix River valley, by Dr. H. A. Prout, in 1850, was the first indica-
tion of the occurrence of this family of fossils at a lower horizon than that
of the Hudson River and Trenton formations.

Before the discovery of graptolites in the shales of Point Lévis, these
rocks were supposed to belong to the age of the Hudson River formation ;
and although it was shown that the graptolites were all of different species
from those previously described, yet they appeared to offer only corrobo-
rative evidence in support of the previously entertained opinion regarding
the age of the strata. It was only at a later period, and from the dis-
covery of numerous other fossils in the same formation, some of them
having a primordial aspect, that its higher antiquity was suspected.

The shales of Point Lévis, with their associated limestones and sand-
stones, since termed the Quebec group, are now regarded as embracing
the period from the Calciferous sandstone to the Chazy limestone, inclusive.
This epoch therefore is entirely anterior to that of the Hudson River
formation, and a careful comparison of all the species of graptolites has
shown that no identical species occur in the two series of rocks.

In the present state of our knowledge, we recognize the Graptolitidee
as beginning their existence at the period of the Potsdam sandstone.
The greatest development of the family, both in genera and species, is

GRAPTOLITES. 53

found to be at the epoch of the Quebec group. Several genera and a
few species are known in the Trenton formation; and a greater develop-
ment, embracing most of the genera and many species, occurs at the
period of the Hudson River formation in Canada and the United States.
In the Clinton strata we have a single species of Graptolithus, and a Retio-
lites ; while Dictyonema and Jnocaulis occur in the Niagara beds. In
all the subsequent geological formations we have found no true graptolites,
and the only representatives of the family consist of fragments of Dictyo-
nema, belonging to a few species. ‘These occur in the Upper Helderberg
and Hamilton formations, above which we do not yet know a species of
any genus referable to this family of fossils. The genus Graptolithus
has its upper limit in the shales of the Clinton formation, and all others of
the family, except Dictyonema, are restricted to the Silurian system. —

The geographical distribution of the Graptolitide is not in all respects
coincident with the extent of the geological formations. Dendrograptus
occurs in the Potsdam sandstone of the St. Croix valley; but neither
this nor any other graptolite is known in other localities of the sand-
stone, so far as I am-aware. ‘The species of the Quebec group, number-
ing more than all the other formations together, have been identified
for a longitudinal extent of about 900 miles; Point Lévis, Orleans Island,
St. Anne’s River (Gaspé), and the western part of Newfoundland, being the
principal localities. But although the Quebec group is known to extend
into Vermont and along the eastern counties of New-York, I am not
aware that graptolites have been found in any authentic localities of that
formation.* Thus far, therefore, these fossils of the group are known
only in Canada and Newfoundland.

The Trenton limestone, while furnishing two species of Graptolithus in
New-York, gives at the west no specimens of the genus proper; but we
have one Dictyonema, a Buthograptus, and an Oldhamia?t im the same
formation in Wisconsin, though not elsewhere known.

The Utica slate at Utica abounds in the remains of graptolites, and
these fossils are of frequent occurrence at Oxtungo Creek, in the valley
of the Mohawk. It is probable that some of the localities referred to the
Hudson River formation, may be in the Utica slate, which, owing to the
disturbed condition of the strata, is not separable from the succeeding
slates.

In the Hudson River formation, the characteristic graptolites, of numerous
species, have been found, in greater numbers than elsewhere, at Norman’s
Kill near Albany ; but they occur at Stuyvesant’s Landing, and at the

* A single branching form, the G. Milesi, has been published in the Geological Re-
port of Vermont. The specimen was found in a boulder of slate, but it is probably of
the Quebec group. [

D

54 CANADIAN FOSSILS.

city of Hudson; while some species have been found near Baker’s Falls
on the Hudson River,‘and at Ballston and Saratoga, New-York. Grap-
tolites of species identical and similar to those of the Hudson River for-
mation have been found by Dr. Emmons in the shales of Augusta
County, Virginia, and also in Tennessee.

The more characteristic species of the formation, G. pristis, G. bicornis,
G. ramosus, G. sextans, G. divaricatus, and G. gracilis, have been
recognized among the collections of the Canada Geological Survey, from
the Hudson River formation in the valley of the St. Lawrence. In the
extension of this formation westward, a few species only have been found in
central and western New-York ; among these, G. pristis is the most com-
mon, while G. d¢cecrnis is more rarely seen. In Ohio, we have no more
than two species from rocks of this formation ; while extensive collections
from the same formation in Wisconsin and Iowa have afforded only three
species (all unlike those from Cincinnati), and one of these has been
found in beds of the same age in Illinois. In the catalogue of fossils
appended to the Geological Report of Missouri, no mention is made of the
occurrence of Graptolitidze in any of the formations.

The great accumulation of materials at the epoch of the Hudson River
formation has been in the direction from northeast to southwest ; and along
this line the black and dark colored graptolite schists, alternating with
coarser beds, have collected in much greater mass than in any other part
of its extent. In the northwestern counties of New-York, Jefferson and
Oswego, where the formation has a thickness of more than a thousand feet,
the graptolites are comparatively few in species, and not of common occur-
rence. The gradual attenuation of the rocks of this formation towards
the west is marked by the extreme paucity of graptolitic forms.

The graptolites of the Clinton strata have not, to my knowledge, been
found beyond the limits of western New-York ; and both their horizontal
and vertical range is very restricted. The graptolitic forms of the
Niagara formation (Dictyonema and Inocaulis) are very limited in their
geographical extent.

The Dietyonema of the Upper Helderberg and Hamilton formations are
known to occur in New-York and in Ohio; and in the northwest a species
has been found in the Upper Helderberg limestone on Mackinac Island.

This distribution of the Graptolitidze, as well as their general association
with other fossils, together with the nature of the sediments, would indi-

cate the proximity of the coast-line as their habitat, and as the zone of
their greatest development.

GRAPTOLITES. 55

TABLE SHOWING THE VERTICAL DISTRIBUTION OF THE GENERA OF THE FAMILY OF
GRAPTOLITIDE.

R)
2
oO o0| ap
4 5 ale
oS 2|\2 :
man ae oa
oI 8 \o |S al epl.©
BIE Idlgl/slalsia=imisis|s
Si So tas] Hig ~lislid
ols Ble S g/2 SS } a eI g [o)
naloNSlg N).5 = 6o| 2 o ie)
ia & © |S | ).8 aio E ei vile
OSA Hl S| OS |slo a) s/o)
BIOOIB (DS lO le Ol4 |p lq |O|o
ah eee Sub-genus Monoprion .......-[..| x |a|sl.-|x a '
RAPTOLITHUS, 9 Sub-genus Diplograptus...-../..| x |x| iC ve
GIIMAGOGRARTUS*scceiete dscns coe plelc tenes SSSR Shale lise salle. RE a
I evAHEA GU RINPNUTS Seoteretctetaroteteleltiei che: eletiorer si ciecereyausye creultorerl MSee ithe Mine lle: cillesesfeveilfaveillecallarsiiis ail eyaclre

FUENEEONTMMSe eaeretat leveled sieiotets sels ete sivtuigerensreree secratonott Sets WD a Ve wilese Ivele alee Meiiace loetiee
AERC) CAMELS tetalalefale) sustelelale) ate ele)leiricrsiare/e =)s/e) sfelsiel|ieve | 5 i

DENDROGRAPTUS .-.+-sees med apetelcate eta n ave rataxtes cues eral Spe See Pavel le ces d fore aes fay l tee Pare fares easel ails
QATTOERAPINUR) 4oHo coo OUdd DUDDDOOOU DOUDIAO DC nial lmcon isla| ees or pele
IDiOT WON. jn cagoopon bouoT Good oDdonddoEoodS Bila? #

PTH OELAPTUTEL A ocac bo domoooodanonod Goddocdallnalyce
EPAWENOG HAUT US) s\alsabel elieleba le siniele)oiaele/ aia =| e's/elele) ee live | SC. Illa 01|/5%

Schoo) Sale| sales |B
RASTRITES ...+.0. Rast teletatardital settee Secee a aes Bocabitect He

IDROHABTRESS God pOb a0 CODD DOO COBO OC COUCIOCIOOIGG nai lacie areal aa
ESUIBENGAIE LS tateveatel are falc’ shereleveletoleevan's evsie eveie elise ae at ae illo s
QD nAITIN ? sions pacino COU MON O Gite Cite OCECCR COE RCI ieaen (-teymn ioal ope

The pre-eminence of the Quebec group, as the period of the greatest
development in the Graptolitidee, is shown in the above table. Of the
fifteen genera and one sub-genus here enumerated, eleven are known in
this period ; while four genera, viz., Phyllograptus, Dendrograptus, Callo-
graptus, and Ptilograptus, are not at present known in any higher position
than the Quebec group, though one of them occurs in the Potsdam Sand-
stone. All those genera having the nearest relations with Graptolithus
proper occur in this group, and the species of that genus found in it are
more numerous than in all the subsequent formations, so far as at present
known.

In addition to circumstances originally favorable to their development
and growth, the subsequent conditions presented during the period of the
Quebec group in Canada seem to have been equally favorable to the
preservation of graptolites, and in no other formation have they been
found with all their parts so entire.

* Under this genus, in the following table I have introduced a sub-genus, Dicrano-
graptus.

56

CANADIAN FOSSILS.

TABLE SHOWING THE GEOLOGICAL DISTRIBUTION OF THE SPECIES OF GRAPTOLITIDA
IN CANADA AND THE UNITED STATES.

Genus Grapro.ituus, Linnzeus.
(Sub-genus Monoprion, Barrande.)
G. abnormis,

GENERA AND SPECIES.

alatus,
arcuatus,
bifidus,
Bigsbyi,
bryonoides,
Clintonensis,
constrictus,
crucifer,
denticulatus,
divergens,
extensus,
extenuatus,
flaccidus, f
flexilis,
fruticosus,
gracilis,
Headi,
indentus,
Logani,
Logani, var.,
Milesi,t
multifasciatus,
nitidus,
octobrachiatus,
octonarius,
patulus,
pennatulus,
quadribrachiatus,
ramulus,
Richardsoni,
rigidus,
sagittarius,
serratulus,
similis,
tenuis,

angustifolius,
ciliatus,
inutilis,
marcidus,
mucronatus,
peosta,
pristis,
pristiniformis,
putillus, n.s.,

Hee See eee eee eee

| Potsdam.

seee rece eee esreseles

CC oe]

swPeeereeeeesseeveies

ee rece eeceneseneeies

eeeeeneesroeeteseseles

seeeseeesece eeecelies

seer eeeesceseesseles

eee esas cease eoenios

ee ee |

seoeeeee cece eeasiae

ee eeeeeeeseeseeries

SHCHIG TE) s easy s aye |'oe

HCE A eis eecel

FY bd bd bt tad bt

see eeeeecece

(Sub-genus Diptocraptus, McCoy.)
G. amplexicaulis,

MEE es- cael.

, Quebec.

Calciferous,
Chazy,

ate cle ate cle ale als
a ee Om Oe

. Ov dals tatae®
ate ste ate
es . eS

ste ate
Ed

se oe te ee
wa ES A FT

ale
as
~

al al al a) at al a) dk °*
BKK RR eR KK,

%

Hudson River.

seles
salee
selee
wales
Pa i
sealer

x
o-| x
eeoles
wale
aelee

eel %

%
eel %
Hie.
oe | %
ol %

*
aol %
ae | %
oe | %

Niagara.

| Onondaga,

eeleclecion

eeleclee

£0} tip
o|®
£I8
a =
Via
Sls
2 ||] eo
Simlola
pul etl ales
Viola!
Elalala
oe ee
4|p |B \o

eeleslerlee
seleosles|ee
saleeleetes
weleclerlee
celeclec|ae
seleclerlen
8 elerlee
saleclentes

| Carboniferous.

t Utica slate.

t From a boulder.

GRAPTOLITES. ot

TABLE SHOWING THE GEOLOGICAL DISTRIBUTION OF THE SPECIES OF GRAPTOLITIDR
IN CanaDiA AND THE UNITED StTatges.—(Continued.)

S)

2

= =|

CS : els C

ewe Sant =| a 2]

GENERA AND SPECIES. a £ isle 5

g/2 clclelala(@F lees
SIS s[slolslelsltelslels|2|s
elo Slel2fslelalsle|els|ais
SlSslflslSislelsie/Zisisls
MOO|s |e [=O l4 lola ie loo

(Sub-genus Diptograptus, McCoy.)—(Con’d.)

Gi. (UAC RiMUGHOMNIMS TT le onocadooosadaDolool Go \lballPallecilbolled|lesieallaai[s allpalic
secalinus, HBCON we. cs sicin loin aiailiem| em |en |= >| ete ls [a «lisse lore llerellle
spinulosus, Bl So ances has Sune locas. (acl |e2solealaolleeltolsalsallsa.c
Whitfieldi, Blococbo sooo scaboteall a6 |lsclle|ooloalloalac|bella ollacloulls
(unnamed,) n. s. Sodb dab 5060 oUn6Ool|Dol| Gn lool|e8iad}icolloalloaliadios|iouiiaails

Genus Crimacocraprtus, Hall.

C. antennarius, Bl oagowoncdabooncallsoll $3" lloalloclloolballoallboleo|sollaoficallc
bicornis, lsboo 6060 dogs saablloolli oo lloolS3lloalsclealloaliMolloallo cia ole
parvus, n. s., lelSSooandouodd OD aolool) So jool(eelloollociasié allele slocllosiioc
typicalis, n. s., lel condo soon deddollooll’ao |loalS|loollas|eollslloalidolloailooh ©

(Sub-genus Dicranograptus, Hall.)

_ C. divaricatus, 31a Hd Bac COOO CUED) Oc)| ec eal Gol oa) (aclolacle leis laelc
furcatus, BI Gn cceS PeMmnOercalacr Sse onions icici aaalleallc
ramosus, Bisse hastooneccraclog) Gs lseles)suSellecltulosiicn|aallsaic
sextans, Tie leisjeiaie etn s slates [of aia) fale fates silmial anil atell tell <beletnl ede

Genus Puyiiograptus, Hall.

P. angustifolius, FELIS Sohn vel so aula efuis eet -se}|iW 2 8 f=/ai| ¢te\} «| eyo)|-1~1| veltavel| ell allisrallsie
Anna, ihm OOO ROEU See Oa es joolaalonieolacldalealleiclioaleaioe
ilicifolius, [elepcioe BpeEDe Sonal |Ool| call ecllod (calle ellarliacoe]oe)|eciion
typus, lBleonnogooOUEHbo cel eolie2 salicc as Ise sHlacdiselloollediios

Genus Rertrouitrss, Barrande.

R. ensiformis, Milos Chao momen Den olocd lee o /AclGolne| Celie Mel lant ea itetel eel leee

venosus, Eos dob co done Gono od aS, Uldolloe nol eelladlealigetoulkalle cles
Genus Retrograptus, Hall.

R. eucharis,t HEME javateh cYuties eve eiohcyaveoy| rei] are cen aol Sel etltes fay sitint afl anes faa) he eel oe
Geintzianus, 15 ROME ROS DOUeM Oe CEO] ol larmn malic lok Eni plcelealiesl ine onl ec
tentaculatus, PEL ite; o) sins at ohh Yao afetctai| o6i\) bee Hieve He icvedl aayl/< oilebel evened spa evel ae

Genus Drenprocraptous, Hall.

D. diffusus, LaLa oly Siac Cee ool | a |fie zed lolol easel eset oi ered lore are Cec se fo
divergens, HE Teteresaleayoisercel cy ove ve avosen {iach SCRE Ite tovei| AIM lleva Theses ansillaves lleva erellbvcll ee
erectus, TEL ees CCRT CCR NSS en eee Sal bam [ete at [| hae Pol tae
flexuosus, DE pepeyen er creiiacm stay erates |utaql Sean tate feces [cue fiery Imeedl ites Latte alfeve [ae eas
fruticosus, Tyran jatelaifeolerasiciers [ovat lave [lavelltve lacie: alloo|jsollon
gracilis, MTree oticnsy evaiiaseva evar eecss | fare i Sek lleva eve raved Rete [revel Srasltorcelbeesd Patel le al lave
Hallianus, IPO, GooDaoOO Rone oolloall eallaullsedaoloslaalleolicclanilca
striatus, ME Heyeea pete a} vena af aoh-avoyeted (rss a: seine ates tava, ep lhoeesl eucal nuedleeat lees! eveell see I ee

Genus CaLuocraptus, Hall.
C. elegans, MEV ere he a fohe sever ehey se aye eter fea SEM ar separ exes Pa (Ue Pay) US 2 ai te

Salteri, AE LWapekeveyevstiay a atch avasayesey ai Peis ae Sete [ Sao | evar Seal tceastlsiell Geer eaitieeal eSeSLES

+ Utica slate. f Utica slate, Lake St. John.

58 CANADIAN FOSSILS.

TABLE SHOWING THE GEOLOGICAL DISTRIBUTION OF THE SPECIES OF GRAPTOLITIDAR
In CANADA AND THE Unitep Stares.—(Continued.)

)

o

2

o

=}

oS
IN

GENERA AND SPECIES. cy
a ke)
Els on

Threag

2/2

o|;s a
(OO

Genus Dictyonema, Hall.

D. cadens, n.s., Pivots bis dae sinicemece aol 4
fenestrata, Breiee etd erate ie leteveialaeif sail) tet
gracilis, Ui ReGsnt Ob aebocsery Kgl boc
amino aniBsy (Ek cicie seicicin mre inievelels iafel] ate
irregularis, ELichaia\ > aretatorera siaverrierel| sta] ae
Murrayi, EL taie Cratelntes thoi a ioretall teil Ae
Neenah, Ub Gopae ogacco 2aa6lboll oo
quadrangularis, EDs areter foto aterctonetcroter hel ese
retiformis, lls cone do goNoaee|lool|-oc
Websteri,t EL yeraintatciere tereretarctete leh ets

Genus Pritrocrartus, Hall.

P. Geinitzianus, TD. cierto ce ses) aeiaraia wiaredl mee ge
plumosus, latroanaduoodocecpalool! &

Genus THamnocraptvs, Hall.

T. Anna, 13ieaeriocoodocomaas| oll <3

capillaris, Elistars siactesiticlers

typus, TH hin saistcinga Siler

Genus Rastrites, Barrande.

R. Barrandi, BD in exaidaateistsietaiaietadl a's Nice

Genus Burnoerartus, Hall.

B. laxus, Te. dew swteetretararetattne f ior

Genus Inocautis, Hall.

I. plumulosa, Ts oe ate maajeiayosarsisieiiaell Mave

Genus OxpHamia [?], Forbes.
QO. MEULICOSS, Unis, beta tells tesa as wes p

Tt Nova Scotia.

EP bo
Slo

a 2i6 .

os lie mn

a o|% 3

> Ts io}

a Iolo . |

fam acl | O | ge | 00/2
. sil esilies Seq olehs
& S sf S/£1s ~ =|
fo} o|B io] a] ee 5 5
eS Slslslelols slg
c |. ao] & o (Q
Siroja|s|MolEla 8) ole
| S| OD lo es |S) O a2 c\o)/a
HIS (0 lZ lO Pp GO|
eefeolorlealactes|erlee| Hleeles
eolecleetecls | He leelecles
eolecleclee| Hleefeslecleeiselee
oe . eel Klecles
alee . eejyecles
efectos eelee eeleelos
% i. . ealeslee
ee ejee ee ef oe
. ae a esleclee
se . .| 4 oe eeleew
eles soles eoleclee
peleelecleeler elecleslecies
ele electee eleeleel|selee
ol Klee alee eleslecleciee
eel Hele elewlee wolecleslee
oo| % . eolesleclecien
Wiese oe eeleeleuwlealee
eelee eleel eofaeleeleasee
He leeleelewleefevleclaclerleelec

GRAPTOLITES. 59

§ VIII.—HISTORICAL NOTICE* OF THE GENUS GRAPTOLITHUS.

Folia GRAMINEUM. .-..Bromel.
{ Linnzeus, Wahlenberg, Beck, Quenstedt, Mur-

GRAPTOLITHUS.++«-- chison, Portlock, De Verneuil, Keyserling,
Mather, Vanuxem, Emmons, Barrande, D’Or-

GRAPTOLITES ..2+--- bigny, Geinitz, Suess, Meneghini, McCoy,

Richter, Salter, Nicol, Harkness, Hall.

PRIODON «ee+.ee «.«e- Nilsson.

ORTHOCERATITES....... Wahlenberg, Schlotheim, Quenstedt, Geinitz.

LOMATOCERAS -....+- Bronn, Hichwald.

PRIONOTUS. «24 eeeess- Nilsson, Hisinger.

FUCOIDES--.....05 ...Brongniart, Eaton, Emmons, Conrad.

PETALOLITHUS.-.+.+-- Suess.

Diprion (sub-genus) .. Barrande.

DipymoGRAPTUS ...---McCoy, Salter, and others.

DIPLOGRAPTUS.... +++. McCoy, Salter, Harkness, etc.

Monoprion (s.-gen.) .. Barrande.

MoNOGRAPTUS «...+-- ey
Geinitz, Emmons.

CLADOGRAPTUS ..-.-
GLOSSOGRAPTUS.....
NEMAGRAPTUS,..2+0- | Hmmons.
TETRAGRAPTUS.-....
DICHOGRAPTUS .-.... | satter.

A. D. 1727. The graptolites of Sweden were observed by Bromel,
who regarded them as leaves of grasses. (Act. Upsal.)

1736. Linneus established the genus Grraptolithus in the first edition
of his Systema Nature; and some years later, in the twelfth edition,
introduced specific names, (@. scalaris being the type of the genus.
This form has been regarded by Wahlenberg, Geinitz, and Barrande
as the G. sagittarius, compressed in a direction rectangular to the
cellules. The G. sagittarius, Linn., is therefore regarded by the latter
author as the veritable historical prototype of the genus Graptolithus
and of the family of graptolites. For my own part, I consider the
G. scalaris, so far as illustrations of that form have come under my
observation, as a distinct type of the graptolite family.

1821. Wahlenberg considered the graptolites of Sweden as very slender
orthoceratites. (Nova Acta. Soc. Scien. Upsal, vol. viii, pp. 92 and 93.)

1822. Schlotheim, participating in the opinion of Wahlenberg, described
and figured a species under the name Orthoceratites serratus. (Petrefak-
enkunde, p. 56, pl. viil, fig. 3.)

* From the earliest notice of the genus Graptolithus to the year 1850, I have added
but little to that which has already been published by M. Barrande in his Graptolites
of Bohemia.

60 - CANADIAN FOSSILS.

1828. Ad. Brongniart described two species of graptolites from the
Transition formation at ‘* Pomte Lévi prés Québec dans le Canada,” as
Fucoides dentatus and /. serra.* (Histoire des Végétaux Fossiles, pp. 10
and 71, pl. vi, fig. 7-12.)

1829 [18317]. F. Holl republished the description of Orthoceratites.
serratus of Schlothem. (Handbuch die Petrefacten., vol. 1, p. 234.)

18—? Prof. Nilsson recognized the graptolites as polyps belonging
to the ceratophydians. He proposed to substitute the pre-occupied name
of Priodon for that of Graptolithus. (See Dr. Beck, in Murchison’s
Silurian System, p. 696.)

1835. Prof. Bronn, adopting the opinion of Prof. Nilsson regarding
the nature of graptolites, gave the name Lomatoceras (Lethea Geognos-
tica, vol. i, p. 50, pl. 1, fig. 13, L. priodon), at the same time arranging
the species with the orthoceratites, etc.

1857. Hismger described five species of graptolites from the rocks
of Sweden, adopting the generic name Prionotus, created by Prof.
Nilsson. Among these are two species of Linnzus, P. sagittarius and
P. scalaris ; to which he added the new species P. pristis, P. foliwm, and
P. convolutus. (Leth. Suecia, p. 118, pl. 85.) In the second supple-
ment to that work, published in 1840, two other species are added, under
the names P. geminus and P. teretiusculus; the latter being of the type
of G. scalaris. (Supp. ui, p. 5, pl. 88.)

1839. Sir Roderick Murchison described and figured in the: Silurian
System three species of graptolites, G. Ludensis, G. Murchisoni, and
G. foliaceus. (Sil. System, p. 695.)

1840. Prof. Hichwald published a description of Zomatoceras distichus,
a graptolite from the Silurian formation of Esthonia. (Stl. Syst. im
Esthiand, p. 101.)

1840. Prof. Quenstedt sought to re-establish the opinion that the grap-
tolites are true orthoceratites. (WV. Jahrb. f. Min., p. 275.)

1842. Prof. Geinitz described and figured five species of graptolites
under the names G. foliaceus, Murchison, G. priodon, Bronn, G. La-
densis, Murchison, G. serratus, Schloth., G. scalaris, Linn., and G.
spiralis, Geinitz; regarding them as belonging to the Cephalopoda.
(NV. Jahrb. f. Min., p. 697.)

1842. Vanuxem identified a graptolite of the Utica slate with the
Fucoides dentatus of Brongniart. Graptolithus dentatus, Vanuxem,
G. pristis, Hall, His.? (Geol. Rep. 38d Dist. N. Y., p. 57, fig. 2.)

1843. Gen. Portlock, in his Geological Report, discussed the nature

* These species are probably identical with those which I have heretofore described
as G. pristiniformis and G. bryonoides.

GRAPTOLITES. 61

of the graptolites, recognizing them as true zoophytes, and indicating
their analogy with Sertularia and Plumularia. He suggested that the
species may form several genera, belonging perhaps to different orders.
The species described and enumerated by this author are indicated under
the names G. Sedgwicki, G. distans, G. tenuis, Portlock; G. convolutus,
G. sagittarius, G. pristis, and G. folium, Hisiagee: G. scalaris, Linn.,
G.foliaceus, Lons. (Geol. Rep. on Londonderry, Tyrone, and Fermanagh,
pp. 317-321, pls. xix and xx.) The species described by this author as
Gorgonia, probably belong to Dictyonema.

1843. W. W. Mather and EH. Emmons recognized Graptolithus dentatus
as characterizing the Utica slate. (Geol. Rep. 1st Dist. N. Y., p. 390,
and Geol. 2nd Dist. N. Y., p. 279.)

1843. J. Hall described Graptolithus Clintonensis, from the shales of
the Clinton group in the Upper Silurian. (Geol. Rep. 4th Dist. NV. Y.,
p- (2, fig. 12.)

1845. Sir R. I. Murchison, De Verneuil, and Count Keyserling enu-
merated G. sagittarius, Hisinger, and G. distichus, Hichwald, as charac-
terizing the Silurian formations of Russia. (Geol. of Russia and the Ural
Mts., vol. ii, p. 882.)

1846. Prof. Geinitz repeats the opinion expressed by himself in 1842,
regarding the nature of the graptolites; and divides them into two sec-
tions, the straight and the spiral forms. In the first section he de-
scribes four species: 1. G. foliaceus, Murchison, (with which he identifies
G. pristis and G. folium, Hisinger, and G. dentatus, Vanuxem); 2. G.
priodon, Bronn, (under which he includes G. Ludensis, Murchison, and
G. teretiusculus, Hismger); 3. G. sagittarius and G. scalaris, Linn.
(which he regards as varieties of the same species), Hwcordes serra, Brong.,
and G. Murchisoni, Beck; 4. G. serratus, Schlot. (Grundriss der Ver-
stein, p. 310, pl. x.)

1846. EH. Emmons published Fucoides simplex [= Graptolithus' seca-
linus|, from the roofing-slates of Hoosic. (Natural History of New-
York, Agriculture, vol. i, pl. xvii, fig. 1.)

1847. J. Hall described and figured fifteen species of graptolites,
mostly new, from the Lower Silurian strata, placing them among zoophytes.
(Pal. NV. York, vol. i, p. 265, pls. lxxii, lxxiii, and Ixxiv.)

1848. Rev. Prof. Sedgwick announced the occurrence of Graptolithus
sagittarius, His., and G. latus, McCoy, in the Skiddaw slates. (Quarterly
Jour. Geol. oe vol. iv, p. 293, )

1848. J. W. aie described G. folium, G. pristis, Hisinger, G. pristis,
var. foliaceus, Portlock, G. ramosus, Hall, G. Tenia, Sowerby and Salter,
G. tenuis, Portlock, and G. sextans, Hall, from the slates of Loch Ryan,
etc. (Quart. Jour. Geol. Soc., vol. v, pp. 15-1T.)

1848. Prof. Philips enumerated the G. Ludensis, G. Murchisoni, and

62 CANADIAN FOSSILS.

three other species in the Builth, Llandeilo, and Haverford-west districts.
(Memoirs of the Geol. Survey, vol. ii, part 1, p. 308.)

1849. James Nicol enumerated ant Toshiba Graptolithus Griestonensis,
G. convolutus, G. Ludensis, and G. lacus. (Quarterly Jour. Geol. Soc.,
vol. vi, pp. 63 and 64.)

1849. J. Hall stated the occurrence of twenty species of graptolites
in the Lower Silurian rocks; two other species having been found in the
Clinton formation.* (Proceedings of the Amer. Assoc. for the Advance-
ment of Science, 1849, p. 351.)

1850. J. Barrande published a memoir upon the graptolites of Bohemia,
describing seventeen species of Graptolithus, of which fifteen were new 3
anew genus, Rastrites, with four species; and the genus etiolites, with
one species. These are all placed among the Polypi. All of these species,
except one, are found in the Upper Silurian; four of them occur in the
colonies of the inferior division, and pass upward to the superior beds;
while one species is restricted to the lower division. M. Barrande has
given in this memvir a resumé of the geographical and geological distri-
bution of the graptolites in the different countries of the globe.

1850. Prof. McCoy described three species of graptolites, proposing
the name Diplograpsus for those with a double series of cellules. He
proposed also the generic name Protovirgularia for a zoophyte which he
refers to the Gorgoniadx, but which may perhaps belong to the Grap-
tolitide. (Annals and Magazine of Nat. Hist., vol. vi, 2nd series,
pp. 270-272.)

1850. Prof. Harkness described the graptolites found in the black
shales of Dumfries-shire, recognizing two species of Rastrites and ten
species of Graptolites. (Quar. Jour. Geol. Soc., vol. vii, pp. 59-65, pl. i.)

1851. Prof. McCoy published descriptions and figures of graptolites
from British paleeozoic rocks, adopting the name Diplograpsus for the
Species with two ranges of cellules. Of fifteen species which he described,
eleven are identified as those of preceding authors, and three of these
are recognized as American species. (British Paleozoic Fossils, pp.
3-9, pl. 1 B.)

1851. Dr. H. A. Prout described a graptolite, G. Hallianus [= Den-
drograptus|, from the Potsdam sandstone of the St. Croix River. (Am.
Journal Science [2], vol. ix, p. 187.)

1851. Edward Suess published descriptions of Bohemian graptolites,
reproducing nearly all of those described by Barrande, recognizing several
other known species, and describing nine new species. He proposed the
name Petalolithus as a substitute for Diprion, = Diplograptus. (Watur-

* This number of twenty species included some forms known, but not at that time
described.

GRAPTOLITES. 63

wissenschaftliche Abhandlungen, vierter Band, pp. 88-134, pls. vi,
vill, and ix.)

1851. J. W. Salter described G. tenuis, Portlock, and G. bullatus, =
G. pristis?, from the Silurian rocks of Scotland. (Murchison, Silurian
Rocks of Scotland, Quart. Jour. Geol. Soc., vol. vil, pp. 173 and 174.)

1851. Boeck; Bemarkinger Angaaende Graptolithen Christiania (cited
by Geinitz; the work not seen by the writer).

1851. Scharenberg, iéiber Graptolithen (cited by Geinitz; work not seen
by the writer).

1852. Prof. Geinitz described the graptolites of Saxony, placing them
among zoophytes, and proposing the genera Monograpsus and Cladograpsus
for certain forms of graptolites, and the genus Mereograpsus to include
Myrianites, Nerettes, ete. He enumerates and describes fifty species of
graptolites of his own, or of preceding authors; and one species of
Retiolites, R. Geinitzianus. (Die Versteinerungen der Grauwacken-forma-
tion, heft 1, Die Graptolithen.)

1852. J.W. Salter described some graptolites from the south of Scotland,
recognizing three species. (Quar. Jour. Geol. Soc., vol. vill, pp. 388-
391, pl. xxi.)

1852. J. Hall reproduced the Graptolithus Clintonensis, and described
G. venosus, = Retiolites venosus. He also described the genus Dictyo-
nema, suggesting its relations with Graptolithus, and likewise the genus
Inocaulis. (Paleontology of New-York, vol. ii, pp. 89 and 40, pl. xvii,
and pp. 174-176, plates xl F, and xl @.)

1853. J. W. Salter. A new species of graptolite (Didymograptus
caduceus, Salter), “from the Lauzon Precipice, Hudson River Group.”
(Quarterly Jour. Geol. Soc., vol. ix, p. 87.)

1855. Dr. Emmons described several new species of Graptolites, and
proposed the generic names of Wemagrapsus, Glossograpsus, and Stauro-
grapsus. (American Geology, vol. i.)

1857. Prof. Meneghini, from collections made by General De la Mar-
mora, described ten species of graptolites from the Silurian rocks of the
Island of Sardinia, of which eight species were new. (Palcontologie de
PLle de Sardaigne.)

1857. J. Hall communicated to Sir William EH. Logan descriptions of
twenty-one new species of graptolites from the Lower Silurian rocks of
Point Lévis (Lauzon seigniory) near Quebec, (many of the species having
compound forms not before known among this family of fossils,) and
proposed several new genera. (Report of Progress, Geol. Survey of
Canada, 1857. See also the Canadian Naturalist and Geologist, vol. iii.)

1859. J. Hall published Motes upon the genus Graptolithus, with. an
enumeration of the Canadian species ; a notice of graptolite-stipes with
reproductive cells, together with descriptions of two new species. (Zwelfth
Report on the State Cabinet, Albany, pp. 45 and 58, 1859.)

64 CANADIAN FOSSILS.

1859. The preceding notes were reproduced, with descriptions of five
additional species of Graptolithus, one Retiograptus, the genus Thamno-
graptus with two species, and one species of Rastrites. (Paleontology
NV. Y., vol. iti, pp. 495 and 522.)

1860. J. Hall, in continuation of the paper from the Twelfth Report
on the State Cabinet (from Paleontology of New-York, vol. iii, Supp.),
described additional species of Graptolithus, Retiograptus, Thamnograp-
tus, and Rastrites as above. (Thirteenth Report of the State Cabinet,
pp. 50-64, 1860.)

1861. J. W. Salter in “ New Fossils from the Skiddaw Slates,” noticed
the occurrence of several species of Graptolithus, and the discovery of a
branching form similar to those which Sir William H. Logan first brought
to light i Canada, which he proposed to term Dichograptus. (Geologist,
vol. i, p. 74.)

1861. Prof. McCoy sent to the writer a proof of a plate of graptolites
from the ‘‘ Paleontology of Victoria.’ Among the figures are species closely
resembling or identical with G. ramosus, G. furcatus, and G. gracilis ;
while others resemble G. pristis, G. sagittarius, &c. The descriptions or
farther illustrations have not come under our notice.

1861. HE. Billings “ On the occurrence of Graptolites in the base of
the Lower Silurian.’ The paper contained a review of the work of Freid-
rich Schmidt, and a comparison of the graptolitic zones in Europe and
America, with a view to show that the graptolite-schists of Norman’s
Kill near Albany are not in the upper part of the Lower Silurian division.
(Canadian Naturalist and Geologist, vol. vi, pp. 844 and 548.)

1863. Sir William H. Logan recognized the occurrence of Graptolithus
bicornis, G. ramosus, G. mucronatus, and G. pristis, characteristic spe-
cies of the shales of Norman’s Kill, in the Utica and Hudson River forma-
tions of Canada. (Geology of Canada, p. 200, and Catalogue of Fossils,
p- 942. Idem, Graptolites of the Quebec group, pp. 226 and 228.)

1863. J. W. Salter (Note on Skiddaw-Slate Fossils) noticed some
new species of graptolites, proposing the new genus Zetragraptus, and
describing the genus Dichograptus previcusly proposed and cited above.
(Quarterly Journal of the Geological Society, vol. xix, pp. 185-140,
with illustrations. )

.*, The Graptolithus from the Hoosic slate-quarries was named by
Prof. Eaton Fucotdes secalinus, and the specimens were thus labelled in
the cabinet of the Rensselaer School at Albany, as known to the writer
from 1832 to 1836; but we have been unable to find any published
description.

(Oil is ol cece Nol Olds a iil Ud Uh

J.—SYNOPSIS OF THE SPECIES OF GRAPTOLITIDA OF THE QUEBEC GROUP,

DESCRIBED IN THIS MEMOIR.

A. SPECIES HAVING A BILATERAL ARRANGEMENT OF PARTS.
Barrande; Monograptus, Geinitz.)

(Sub-genus Monoprion,

Genus GraPTOLiTHus, Linneeus.

a. Species consisting of two stipes from a single axis.

tus, McCoy ; Cladograptus, Geinitz in part.)

Plate.

(Gio MGS) GGadoodolbonpedooO DOD CoonddoDS
ATUL USM are, Cot stat wtatad Shes er dieotatetel alcehetctadet
DUT HUSM Herat eatctctetaatetatatcern sce intemetetts ealee
HOUTA Prarie evarclcierciciacvelcctetatetetstats et tctahas
ATU GL@NGUIS) 2 mial ofieiascicicletatutete tala tatcteictecatetatete ele
EXAMS etaters/sersicrcieareleleistetctes ciercisie ree
GORTUWAGIES a5 doedtoocodcdoncodosadood

SIMA U Sweretevatareraretarctelcietsls ctor sieeve er elerete
ALCU MUS Maletal wine! arelereleietaraiersre/<leisre’iclwisisiel ols
EXILES USM velatielintateferepoyaleyaitelsfareterersieretcis/erels
PEMA NUIE o6 nonbodobocsoocoSaodudne =

ow DD PH eB eS ee

EWMRHUIOS sosuoocesaoounedoaucsOnade

(Didymograp-

Figure.
1- 9
10-15
16-18
9-10
20
21-22
23-27
1- 5
6-10
11-16
1- 8

6. Species consisting of four simple stipes from a single axis, with or
without a central disc. (TZetragraptus, Salter. Dichograptus,

Salter, in part. )

Plate.

GU PU ONGIMes seis aitoisieiels eiaisysisisjeeresieisleeh ic
PE YOH Oltbe smerctatertlele's/eis siaicisi= coisa lelalseiere’e
OIVOUOIMEREgitecie sc cesrce eer acess wtels
Gemticulaseyentstcielslatestclovsievelee cise crete
QUITE AGIA DUG wtls:ccc\c'e ds nisi sini ons
Qa GTO TA CHA TS alesse cline 's6.0.<:2.0.'s 0'elaials
ELUGL COS US) epefeterateyelsidis’sje/sicieleisicic sivic'eeeie ©
HAULS coodocoucgousocgasudueddat
CLUCICI staetatetaietelcietelerereurelaye a stanciere cheers
He adit repeveleelatemstefapatcheysielevs totais sie SuoseC'S
el VTUSH svetctateved af sievoictefapeliaicrareisis)v aie) eel e/sieye
BAGS ily crates eeleleletsfel sisi nialei|sietoisisisieiieieisihO

AvAAMAAHAAD AE HD SP

Figure.
11-12
1-11
a
12-16
1-5

6
6- 8
3

22-30

66 CANADIAN FOSSILS.

ce. Species consisting of eight simple stipes proceeding from a single
axis, with or without a central disc. (Dichograptus, Salter, in

part.)
Plate. Figure.
G. octobrachiatus ...... ah alate stevelaecinye naar (0. nic 1-7
OCLODEACHIADNS ereretelelsistolale’-leies(si0\ ajeia ceva tarevete 1-4
OCtONATIUS. wecceecsceccsssscecens Hoon) ago | 5

d. Species consisting of more than eight simple stipes proceeding from
a single axis, with a distinct broad corneous disc. (Dichograptus,
Salter, in part.)

Plate. Figure.
GAO GANTT ereinte 0101+ «ics wlsieielei=,sivi cle cisleisisniviele 9 eeee 1-9
DUO GAAS WEE leone bnlietes scabs cadniceiceeeRl, senaat t

e. Species with the stipes proceeding from a single axis, and more or less
frequently branched during their entire length; not known to
have a central disc.

Plate. Figure.
(Cp aierallic) o6 cae ago booocdaDOdoS coonbn Gogo) GAsn » See
TIPLAMS 1c vice sie veces enss sie neonoscdooaall Maga4 le
BPNOLMS ee cine /a/eustere pongoDoce ponocosooodll aesr 6
Richardsoni ..... nisfones stelslereletete tains Sodouc IPA h55 1-8
TAMULUS «0. ceeeeee efalexeternreteratels(ejete eesceelZ coen 9,10

B. Species (so far as known) CONSISTING OF SIMPLE STIPES WHICH ARE CELLULIF-
EROUS ON TWO SIDES.

a. Cellules tubular, inclined to the axis, aperture subquadrangular.

Plate. Figure.
G. (Diplograptus) pristiniformis......... 13 .... 15-17
oe rhelty nba agin Sysinieicieverarats WSF iajers ee

6. Cellules short and square, aperture transversely-elliptical, appar-
ently excavated in the margin of the stipe.

Genus CLIMAcogRapPtus, Hall.

Plate. Figure. —
OC PAnteNNATiWs c/s terece cre Aalalee eieletee vee nieins 13 eeee 11-13

Genus Rerioiitss, Barrande.

Plate. Figure.
R. GNSILOPMIS Lek vinci aroisierctaels ars lave lola eis. b dia 14 eeee 1-5

GRAPTOLITES. 67

C. SPECIES WITH NUMEROUS SIMPLE STIPES FROM A SINGLE AXIS, IN BILATERAL
ARRANGEMENT. (Other species known only as simple stipes.) (Sub-genus
Diprion, Barrande; Diplograptus, McCoy.)

Genus RETIOGRAPTUS, Hall.

Plate. Figure.
R. tentaculatus eeeereeeoeseeesaseose8e 00080 14 eoese 6-8

D. SIMPLE STIPES WITH QUADRILATERAL ARRANGEMENT OF PARTS.

Genus Puytiograptus, Hall.

Plate. Figure.

Eeatiy PLS matetel siefalel oie el/ajinlelaials\ aha) eheteferelaletstayete LOreis/a/c'ohtoy 11
NCOs oabondeooadoneapoosouGo0HO NS noon EKO)
ANNE 55 00 0000 cond dogoonoCoaDdnooDcoDO®) Unoon | IEG
ANGUStIfOlIUS weeacecscceeccccceceeseelG «se- LI-21

EK. SPECIES HAVING STEM-LIKE AXES WITH NUMEROUS IRREGULAR RAMIFICATIONS.

Genus Denprograptus, Hall.

Plate. Figure.

PME EUG SSH cveiessicrsiovoyapabenerern miaraielerotatelorevslen Tad weirsie) 012

ALE RCLO SUS! Ai stctaraicielv rene tars cusavereveiersterersraiate eel | rejictey Maa:
CINE ERG bob ConU a gOo Bob panodbe coo nciel ilemgcor ars)

SIMI UILS hose roiee never felisveieies fevetolesreialeiwiatsiolerel efor ommlnkiuencfetaye 5
CROCUNS DUOC ROO OOOO CLO ODEO Oe Ione OG 2 Ll mS cna |

EMULE OSS orale slolcteelseie sieleselers eiaisielaren Lite acer | 1y (O569
GHEMCWES, co SgnoouncD NG oe 1
5

LACTIC aelaieieysrelefsyelerelorelsles

eeoeeeoeeve eee eo 18 OOO

eeoeesenrteaoed 18 eecne

F, SPECIES WITH FLABELLATE OR FUNNEL-SHAPED FRONDS, THE BRANCHES OF WHICH
ARE CONNECTED BY REGULAR DISSEPIMENTS GIVING A FENESTRATE STRUC-
TURE, OR BY UNFREQUENT AND IRREGULAR TRANSVERSE BARS, AND SOME-
TIMES BY AN ANASTOMOSING OF THE ADJACENT PARTS OF THE BRANCHES.

Genus CaLLoeraptus, Hall.

Plate. Figure.
OSele oan aiiatratatatera acces olsjale sicwalaaleteiaars 19 eooo 1-4
Saliterimmyyverteyterctsiciecesaavs avercveudiareunerees 19 eoee 5-8

Genus Dicryonema, Hall. (Grapropora, Salter.)

Plate. Figure.

PD) Innes ular iseyreatlaeiieeiens =< sisie\aretemeinicis U2 Oi seit, lolooe
HOWE, ooootodgsoudoboocodsdGdounED ZO) “cea5) Be
QuadrangUlarigncsiaccvecsccs erences 20

eeoeseo 5
Murrey. jtelattatetsteistare iaiets shatayateleraiel selo/cteho 6

68 CANADIAN FOSSILS.

G. SPECIES CONSISTING OF BRANCHES WITH SUB-CYLINDRICAL OR ROUNDED AXES; THE
ULTIMATE PINNULA ELONGATE, SETIFORM, OR PLUMOSE, AND ALTERNATELY
ARRANGED ON THE TWO SIDES OF THE AXIS OR LARGER RAMUS.

Genus Prinoeraptus, Hall.

Plate. Figure.
up UMYOS US terrae veraretonelclataltstelals sielelo\(ela/slele/a/elelelera ntl ametatets 1-4
GIMitZ anise peveror siete ayaa) oveia.'s wie: e.ete.e ece/everevelere 21 econo 5-8

Genus THAMNOGRAPTUS, Hall.

MME MOAN Ao Gao ooGddObosDFOORGODODODS 2b Gogg ©

SPECIES INTRODUCED FROM THE UTICA SLATE OF LAKE ST. JOHN, FOR COMPARISON
AND ILLUSTRATION.

GRAPTOLITHUS.
Plate: Figure.
G. (= Monoprion = Didymograptus) flaccidus..... 2 .... 17-19
G. (= Diplograptus) quadrimucronatus...... Gonos opoa ae
RETIOGRAPTUS.
Plate. Figure.
Retiopraptos CuCharis js,s,e0c0ce ee pra aciele seus sce'ee) LAT) tle nls 9

§ I[.—DESCRIPTIONS OF THE SPECIES OF GRAPTOLITIDH FIGURED
IN THIS MEMOIR.

Genus GRAPTOLITHUS, Linneus.

Generic Characters.—Polypidom or frond consisting of slender elongated
stipes or stems, which are flattened and quadrangular, and may be simple
or compound, and sometimes bifurcating. The cellules take their origin
from a common body or canal, which is parallel to a slender axis.

Some of the species have the cellules in single series, and others have
them in two series, arranged on opposite sides of the stipe.

Those species with the single series of cellules (Monoprion, = Mono-
graptus) have the axis marginal; while those with the two series of
cellules (Diprion, = Diplograptus) have each series entirely independant
of the other and separated by a double solid axis, leaving no communi-

GRAPTOLITES. 69

cation between the series, each of which has its common body or canal,
as in those with the single series of cellules. This character is clearly
shown in some of the bi-celluliferous species, which subdivide above the
base by the dehiscence of the axes.

The species having a single series of cellules are developed in a bilateral
arrangement of the parts on the two sides of a central point or radicle.
The simplest forms known consist of two single elongate stipes ; others
have four, eight, or more simple stipes ; while in other species the stipes
are variously bifurcated ; but in all they are symmetrically and bilaterally
arranged upon the two sides of the specimen. Many of these compound
forms have the bases of the stipes united in a central corneous dise or cup,
which is of the same substance as the stipes, thickened in the middle, and
attenuate at the margins, and which in the living condition was probably
of a concayo-convex form.

The centre of these dises on the exterior side often presents a small
prominence or point, which however does not bear evidence of having
been attached, at least during the later periods of the animal’s life.

The species under this genus may for convenience be distributed in
two sections with several subordinate divisions, as shown on pp. 65 and 66.

1. GRAPTOLITHUS NITIDUS, Hall.
Plate I, figures 1-9.
(G. nitipus, Hall: Geological Survey of Canada, Report for 1857, page 129.)

Description.—Frond composed of two simple stipes proceeding from
a small radicle, and diverging at an angle of about 175°. Stipes narrower
at the base, and gradually widening towards the extremities, which in
perfect specimens are somewhat rounded from the partial development of
two or three of the terminal cellules. Radicle short, abruptly tapering to
a slender point. The stipes in their greatest width are from six to
ten hundredths of an inch, while near the base they are often not
more than five hundredths of an inch in, width. The proportion of the
stipe occupied by the common body is about one sixth, or less than one
sixth of the entire width. In the broader stipes, the limits marked by the
pustuliform elevations indicate the bases of the cellules. In some spect-
mens, one fourth of the width is occupied by the common body.

Cellules long and narrow, from thirty-two to thirty-four in the space
of an inch, curving slightly upwards, nearly twice as large at the

E

70 CANADIAN FOSSILS.

aperture as at the base, and about three times as long as their greatest width
when the stipe is flattened ; inclined to the axis at an angle of from 35° to
45° ; division-walls of cellules in contact, or united for three fourths of their
entire length ; margin of the aperture straight, or slightly curved near the
anterior edge, making an angle of 110° or 112° with the axis ; the anterior »
margin, in the broader stipes, lies over the base of the third cellule in
advance. The limits of the cellules are strongly marked by a line imdi-
cating the place of the partition or divisional cell-wall, which on one side
often terminates below in a pustule.

This beautiful little species differs very distinctly from all others of the
genus which I have studied; and it bears little relation to any of the
European forms described, so far as they have come under my observa-
tion. The substance of the stipe is usually thickened, brownish-black in
color, smooth or slightly wrinkled from desiccation, and rarely marked
with distinct striz parallel to the cell-margins. The strize apparently
indicate the successive stages of growth or development of the cell-walls.
The divisions between the cellules are strongly marked by what usually
appears to be a distinct groove produced by the folding of one cell over the
other at the lme of junction, this line indicating the place of the cell-partition.
The sheath or common body of this species is usually partially filled
with stony matter, and a section presents an extremely elongated oval
form. This condition may be partly due to the original character of
the body, or to the nature of the matrix; which is less finely lammated
than some of the graptolitic slates, but preserves the fossil in a very beau-
tiful manner. The imprints are stamed by oxide of iron, and the striz
marking the divisions of the cellules are often well preserved. The trans-
verse strize parallel to the apertures of the cells are often distinctly seen in
casts of the interior.

The minute tubercles marking one side of the stipe are rarely shown
on the two sides, and sometimes on neither side. ‘The conditions of
pressure may have had some influence in causing this appearance ; since
the pomt of the abrupt bending of the partition between the two cellules
may have resisted more than the other parts, and thus produced the
promimence observed. The proportions of parts are subject to slight
variations, dependent mainly on the degree of stipe-development. In
the narrower forms, the-cell-aperture often lies vertically above the base of
the second cellule in advance,,instead of above that of the third as in the
wider forms. In the relations of the cellules to each other, they appear .
as if the pressure had been exerted obliquely to the direction of the axis;
the cellules being slightly en échélon. 'There are however many indica-
tions pointing to such an arrangement as being the original disposition of
the cellules on the axis, not only in this but in other species.

The impressions of G. bryonoides resemble those of this species; but

GRAPTOLITES. 71

the stipes are broader, the striz less rigid and distinct, and the tubercles
and coarser denticles of G. nitidus are absent. In mode of growth and
general aspect, this species resembles G. serratulus of the Hudson River
group (Pal. N. Y., vol. 1, p. 274, pl. Ixxiv, fig. 5 a, 6); but in the latter
the denticles are coarser and more oblique, the lower side bemg much the
longer, and the stipes are more distinctly lmear; while in G. nitidus the
stipes become gradually wider from the base, and are very distinctly striate
and pustulose in well-preserved specimens.

EXPLANATIONS oF FiguRES OF GRAPTOLITHUS NiITIDUS, Hall.
Puate I.

1. A young individual preserving the radicle and the two stipes.

2. The extremity of a stipe enlarged, showing the partially-developed cellules.

3. A larger specimen of similar character to fig. 1, showing the pustules at the
base of the cellules. The extremities are not quite entire.

4. A part of the left side of fig. 3 enlarged, showing the pustuliform elevations.

5. An enlargement from another specimen, with the cellules obliquely compressed,
and the pustules obscurely shown.

6. Two smaller individuals, which, from juxtaposition, similarity of size, etc., seem
as if they may have originated from a common base.

7. An impression of a more extended form, which is proportionally narrower than
fig. 3.

8. A still narrower form of stipe, diverging almost rectangularly from the direc-
tion of the radicle.

9. A well-preserved small individual, enlarged three diameters.

Formation and Locality.—Shales of the Quebec group; Point Lévis.

2. GRAPTOLITHUS PATULUS, Hall.

Plate I, figures 10-15.
(G. patuLus, Hall: Geological Survey of Canada, Report for 1857, page 131.)

Description.—Frond composed of two simple stipes diverging almost
rectangularly from a small radicle. Stipes long, linear, widening very
gradually from the base to the extremities, which are somewhat rounded
from the immaturity of the later cellules. Width from base of serratures
to the back of the stipe, from one sixteenth to one twelfth of an inch.
Surface strongly striate in the direction of the cellules; strize curving.
Radicle minute. The proportion of the stipe occupied by the common
body varies from a perceptible line to one fifth of the entire width, and is
dependent partly or entirely on the direction of the pressure.

72 CANADIAN FOSSILS.

Cellules distinctly limited by the partition-walls, about from twenty-four
to twenty-six in the space of an inch ; rather wide, making an angle of about
60° with the direction of the axis, and slightly curving upwards; their pro-
portions vary according to the width of the stipe, bemg from three to four
times as long as wide. Outline of the aperture curved, concave, making an
angle with the axis of about 130°; on the lower or posterior side produced
into mucronate points which curve gently forward: walls of the cellules
distinctly striated parallel to their margins, for one half the depth. The
anterior margin of each cellule is vertically above the base of the second
cellule in advance.

Fragments of this species are numerous upon some slabs of greenish or
blackish-green slate where other species occur. ‘The remains of single
stipes are sometimes four or five inches in length, showing in different
individuals little variation in width after becoming perfectly developed,
which occurs within an inch of the radicle. Sometimes the stipes are
compressed vertically, and present the smooth limear base or exterior,
which is less in width than when compressed laterally. The lateral faces
of the stipes exhibit some variety of surface, dependent on the degree of
compression, or in some instances, on the replacement or filling of the inte-
rior by iron pyrites. In these cases, or when the branch is not flattened,
the surface is deeply striated or wrinkled obliquely. Sometimes when
extremely compressed, the surface has an appearance of vesicular struc-
ture, which is probably due to influences attending the mineralization of
the fossil, or the fillmg up of the original canal.

This species is palpably different from the last in the greater extent of
the stipes, and in their almost perfectly linear character. The form of the
denticles, and their angle with the axis, as well as their proportional dis-
tance, are distinctive characters. The G. virgulatus of Beck (Geinitz’s
Graptolithen, page 387, pl. v, fig. 86) bears some resemblance to this
species in the figure of natural size; but our species does not correspond
with the enlarged figures.

EXPLANATIONS OF FiguRES OF GRAPTOLITHUS PATULUS, Hall.
Puate I,

10. A specimen preserving the radicle, and a stipe on one side two and a half
inches in length.

11. The distal extremity of a larger stipe. Some of the cells are filled with
iron pyrites.

12. A short stipe broken off near the radicle, showing the narrow form near the
base, and a greater width beyond, exceeding that of the ordinary forms.

13. A part of fig. 12 enlarged.

14. A part still further enlarged to show the striz parallel to the cell- -apertures.

15. An enlargement from fig. 11, where some cells are filled with iron pyrites,
showing their extension almost to the back of the stipe.

GRAPTOLITES. 73

Formation and Locality.—Shales of the Quebec group; from loose
masses below the village of Point Lévis.

8. GRAPTOLITHUS BIFIDUS, Hall. (un. s.)

Plate I, figures 16-18 ; Plate III, figures 9, 10.

Description.—Frond two-stiped: stipes diverging from the small short
radicle, and curving slightly imward, and thence extending in right lines
including an angle of from 15° to 20°, varied by growth or accident. Stipes
very narrow, rounded at the base, and gradually expanding above, attain-
ing their greatest width at about two thirds of the distance from the base,
from which they are gradually narrowed to the extremity; they curve on
the celluliferous margin, and are essentially straight on the back. The
cellules continuing to increase in length as the stipe is extended to
the pomt of greatest width, give the peculiar curving outline to the
celluliferous margin. In the stipes of ordinary width, about one sixth
of the space is occupied by the common body ; though this proportion
varies with the development of the stipe. Test thin, nearly smooth,
or with faint striz parallel to the cell-margins: divisions between
the cellules strongly marked, and frequently termimating below in
a minute pustule. The width of stipe varies from one fifteenth of an
inch at the base, to one eighth or even one fourth of an inch in the widest
portions. Cellules long and slender, except afew at the base, and some
partially developed near the apex: the length of the cellules is from three
to four and a half times their width, according to the degree of develop-
ment, and they incline to the axis at an angle of 48° near the lower part,
curving more directly upwards in the middle, or more fully developed part
of the stipe. Near the base of the stipe the angle of the cellules is greater,
and towards the apex it is less, until the last few are inclined at a very low
angle. The cellules are free for from one fourth to one third of their length.
The apex is extended in a sub-mucronate point. The curving of the cell-
margin forms an angle of about 120° with the axis in the widest part of well-
developed stipes.

This species is very peculiar, differing from all others described in this
memoir (except G. pennatulus) in the great inequality of width in the
stipe, and the apparently continuous increase of width from the extension
of the cellules; while the younger cellules near the apex seem to be
slowly developed. The stipe at the base is nearly round. Of the earlier
cellules usually four or five and sometimes six or seven do not attain

74 CANADIAN FOSSILS.

the full proportions. In several specimens (and indeed in all those upon
which the species was originally founded), the stipes diverge from the
radicle at an angle of 15° or 20° with the celluliferous faces on the inner
or approximate margins. A later examination of other collections shows
some specimens where the divergence is greater, and the development of
parts more excessive.

Three individuals of this species from the shales at Point Lévis preserve
very constant characters in the mode of growth and structural details. One,
a single stipe much longer than the others from the same locality, pre-
sents some departure from the prevailing characters, and is referred with
hesitation to this species. Another specimen among later collections from
above the river St. Anne, has more divergent stipes and a stronger form
than those first described. In the imperfect condition of preservation of
these specimens, it is not easy to determine what extent of variation in
individuals of this form may be due to the mode of growth and to other
causes.

EXPLANATIONS OF FiGURES OF GRAPTOLITHUS BIFIDUS, Hall.
Puate I.

6. A small specimen from the same fragment of slate with fig. 17.
17. An individual of ordinary size.
8. An enlargement of the upper part of one stipe of fig. 17.

Puate III.
9. An individual of this species, having a greater divergence of the stipes than is
usually observed.

10. An enlargement from one of the stipes of the preceding, showing the form of
serratures, and the minute pustules at the base of the cell-divisions.

Formation and Localities.—Shales of the Quebec group ; Point Lévis,
and three miles above the river St. Anne.

4, GRAPTOLITHUS INDENTUS, Hall.

Plate I, figure 20.

(GRAPTOLITHUS INDENTUS, Hall: Geological Survey of Canada, Report for 1857, page 128.)

Description.—Frond consisting of two simple stipes, diverging at the
base from a slender radicle, and making an angle between the two of 50°
for the first quarter of an inch, and above this continuing in a nearly par-

GRAPTOLITES. ‘ 75

allel direction. Test somewhat rough : width of stipe about six hundredths
of an inch; the back marked by a strong axis, and a scarcely appreciable
portion occupied by the common body. Cellules narrow, distant, about
twenty in the space of an mch; each one having a length of about three
times its width, half of the length being free ; inclined at an angle of.
about 35° to the axis: aperture at right angles to the axis; the apex
acute and pointed.

This species bears a resemblance to G. extenwatus in the width of stipe
and proportional distance of cellules; but the angle of inclmation of the
cellules and the form of aperture are quite different ; the absence of
pustules at the base of the cell-divisions is also a very distinctive character.
The stipes of this species bear a very close resemblance to those of G.
quadribrachiatus ; but the individual figured, in which the base is pre-
served, shows in its peculiar curving and smaller serratures near the base, a
feature which belongs only to the two-stiped forms. The cellules also
appear to be narrower, and are slightly closer in their arrangement ;
stipes of the same size of the two species, showing respectively eighteen
and twenty cellules in equal spaces.

EXPLANATION or Ficure or GRAPTOLITHUS INDENTUS, Hall.
Puate I.

20. An individual of the natural size, the continuation of the stipes having been
broken off.

Formation and Locality.—Shales of the Quebec group; Pomt Lévis.

}. GRAPTOLITHUS EXTENUATUS, Hall. (n. s.)
Plate I, figures 21, 22.

Description. —Stipe slender, linear, straight ; substance smooth, except
the striz mdicating the cell-partitions ; width a little less than one
twentieth of an mch, the common body occupying a little more than one
quarter of the width. The back of the stipe is marked by a strong marginal
axis. Radicle unknown.

Cellules narrow, very gradually expanding from the base, length about
three and a half times the width ; making an angle with the axis of nearly
20°, and curved near the base. Apertures truncate, slightly curved to-
wards the anterior margin, and nearly at right angles with the axis; free

for about two fifths of their length ; about twenty-four in the space of an

76 CANADIAN FOSSILS.

inch. The apex of the cell-denticle or aperture is a little forward of the
tubercle marking the base of the second cell in advance. ‘The cell-
partitions or septa are not strongly marked, but distinct under a lens, and
terminate below in a minute rounded process or pustule.

(The specimen on which this description is founded is a fragment
of two and a half inches long. Other fragments on the same piece of
weathered shale appear to be identical with it, but are too obscure for
satisfactory determination. It is supposed to be a bibrachiate form.)

This species bears considerable resemblance to the figure of G. tenuis
of Portlock, as given by McCoy (Brit. Paleozoic Fossils, pl.i. B, fig. 4 a,
b); but the stipe of that one shows no pustule at the base of the cell-division.
The original figures of Portlock do not however correspond so nearly with
our species in its cellules, while the axis is not so strongly developed.
Compared with any of the Canadian forms, except G. extensus, it is
proportionally narrower ; with that one it corresponds in the number of
serratures in the same space ; but the angle made by the cellules with
the axis is very different, and the presence of pustules is a distinguishing
feature. From all other analogous forms, this one varies in the form,
proportional number, and inclination of the cellules.

EXPLANATIONS OF Figures oF GRAPTOLITHUS EXTENUATUS, Hall.

Prats I,

21. A fragment of the stipe, natural size.
22. A portion of the lower extremity enlarged ; a part of the specimen retaining
the substance of the fossil, and a part being an impression in the slate.

Formation and Locality.—Shales of the Quebec group; Point Lévis.

6. GRAPTOLITHUS consTRIcTUS, Hall. (n. s.)
Plate I, figures 23-27.

Description—Frond composed of two slender stipes, which diverge
almost rectangularly from a minute radicle, or are usually bent a little back-
wards, a feature which is more conspicuous in young individuals. The
stipes attain their full dimensions near the radicle, maintaining nearly an
equal width throughout their length : the extremities are somewhat rounded
from the partial development of some of the terminal cellules. The stipes
in their greatest width are about nine hundredths of an inch, and vary

GRAPTOLITES. vi

from five to nine hundredths in their different stages of growth and devel-
opment. .The common body occupies a very small proportion of the
entire width, and its limits are not distinctly defined. Surface of stipes
quite smooth ; test very thin, and cell-walls usually obscurely marked.

Cellules of moderate length, from twenty-four to twenty-six m the
space of an inch, and inclined to the axis at an angle of about 32°, as
indicated by the lines of the cell-partitions : line of the aperture truncate,
or very slightly convex, making an angle of 120° with the axis, and
nearly rectangular to the direction of the cellule. The cellules, in their
lower part, and for two thirds of their length, are straight, and scarcely
wider throughout than at their origin: at this point, just before becoming
free, they are abruptly expanded on the posterior side, and this margin
of the free extremity makes a larger angle with the direction of the axis.
This expansion of the cellule is perhaps as properly a sudden constric-
tion just below the orifice, or at the base of the cell-denticle. The cell-
denticles, under a strong lens, are seen to be finely striated parallel to
the line of the aperture.

This species in its mode of growth and general form resembles G. patulus,
but in its development it earlier attains the full width of the stipe. It
is always smoother on the exterior surface, and the cell-walls rarely make
distinct strize, as in that species, though this character is visible under a
lens. The form of the denticles is however very characteristic; and
this at once distinguishes it not only from G. patulus, but also from every
other species of this group. It is associated in the same slates with
G. patulus and G. quadribrachiatus.

A specimen in the shales of Gros Maule, preserving all the essential
features of this species, has apparently a thicker test, and the interior is
partially filled with stony matter, so that the parts are more clearly seen.
In this one the cells show a very gradual expansion towards the aperture,
and a slight curvature of the cell-partitions near the base, while the con-
striction below the cell-mouths is more strongly pronounced.

EXPLANATIONS oF Figures or GRAPTOLITHUS consTRICTUS, Hall.
PuateE I.

23. A young individual of the natural size.

24, An older specimen.

25. A part of a much more extended stipe, but which is not wider than fig. 23.

26. A part of a stipe from Gros Maule.

27. An enlargement showing the form of cells, the cell-denticles or apertures, and
the characteristic apparent constriction. '

Formation and Localities.—Shales of the Quebec group; from some
loose masses below the village of Point Lévis, and from Gros Maule.

78 CANADIAN FOSSILS.

7. GRAPTOLITHUS SIMILIS, Hall. (n. s.)
Plate II, figures 1-5.

Description.—Frond consisting of two narrow sublinear elongate stipes,
proceeding from a small pointed radicle, from which they diverge almost
rectangularly : stipe acquiring its full width near the radicle, having a
short space near the base without cellules ; extremities somewhat rounded,
from the partial development of the cellules. The stipe varies from five
to ten hundredths of an inch in width: the cell-partitions, when visible,
extend nearly to the back of the stipe, leaving a narrow space occupied by
the common body. Surface nearly smooth : cell-partitions seldom seen, and
not distinetly visible ; the specimens extremely compressed.

Cellules somewhat short and broad, little curved, about twenty-one
in the space of an inch, inclined at an angle of 23° to the axis. The
cellules are from two to three times longer than wide, this depending
on the width of stipe: margin of aperture truncate, making an angle
with the axis of from 118° to 180°; the cell-walls show obscure striae
parallel to the aperture. The apex of the denticle is vertically above the
posterior basal edge of the second cellule in advance.

The nearest affinities of this with any American species are with those
designated by me as G. sagittarius and G'. serratulus from the shales
at Norman’s Kill, near Albany ; but the cellules make a much less
angle with the axis of the stipe, and the whole body is less robust than
the larger specimens of Gt. sagittarius. It bears a remote resemblance
to the figures of G. nuntius of Barrande, as given both by Barrande
and Geimitz; approaching more nearly to the figures of G. sagittarius
of Hisinger, as given by Geinitz, than to any of the others; though these
figures give a higher angle between the axis and the direction of the
cellules. The angle made by the cellules of: G. nuntius with the axis,
as given by Barrande, is 45°, which corresponds with our Norman’s
Kill specimens ; but they differ in other respects. The present species
differs from most of the other Canadian species in the straightness of its
stipe ; and in the low angle made by the cellules, from all others, except
G. indentus.

The specimens are replaced by pyrites in a dark or nearly black slate,
and associated with other forms too imperfect to be identified ; one of them
resembling G. guadribrachiatus, and another G. bryonoides.

GRAPTOLITES. 79

EXPLANATIONS oF Figures OF GRAPTOLITHUS sIMILIs, Hall.

Puate II.

1. A very young individual of this species.

2. An individual somewhat more matured.
3, An enlargement showing the form of the radicle, and the cells near their origin,

with a non-celluliferous space between.
4. A fragment of a longer stipe, which is imperfect at both extremities.

5. An enlargement of fig. 4.

Formation and Locality —Shales of the Quebec group; three miles
above the river St. Anne.

8, GRAPTOLITHUS ARCUATUS, Hall. (n. s.)
Plate II, figures 6-10.

Description —Frond consisting of two simple widely divergent stipes
proceeding from a small radicle, and bent backwards or downwards, mak-
ing on the upper side nearly or more than a right angle with the direction
of this radicle, and then curved gently upwards; presenting a broadly
arcuate stipe gradually expanding in width from the base to the extremity,
and celluliferous throughout its entire length. A single denticle, or
similar process, appears above the rootlet. Radicle short, obtusely
pointed. The stipe is from four to ten hundredths of an inch in width.
The cellules reach nearly to the back of the stipe, leaving a narrow space
to be occupied by the common body. ‘Test extremely compressed in the
specimens examined, and towards the extremity of the cellules almost
transparent. The whole has a white or silvery lustre (probably due to
iron pyrites), and no lines or striz are visible except those marking the
separation of the cellules.

Cellules narrow and very little expanded towards the aperture, about
twenty in the space of an inch, slightly curving upwards, and inclined to
the axis at an angle of about 30°, varying a little with the curvature and
development of the stipe ; from three and a half to four times as long as
broad. Cell-apertures slightly curved, nearly vertical towards the poste-
rior side and arching towards the anterior side. The apex of the denticle,
or posterior side of the aperture, is vertically above the base of the third
cellule in advance of it.

In some specimens the radicle is broken off, and there is a process on
the opposite side, giving the appearance of a radicle on the celluliferous

80 CANADIAN FOSSILS.

side of the specimen, as if the cellules had been turned downwards ; but }
this appearance is fallacious. In examples where the radicle is broken from
the margin of the stipe, the question is suggested whether it may have been
a quadribrachiate species; but the pointed radicle in others is opposed
to the supposition. In the specimens from which this description is drawn,
there are several examples of two individuals lying with the celluliferous
margins nearly or quite in juxtaposition ; while the stipes crossing each
other at a distant point may give an erroneous impression regarding their
mode of growth.

On a cursory examination of the specimens before us, this species is
readily identified by the peculiar curving of the stipes; differing in this
respect from all the bibrachiate forms which have been observed. In the
form of the denticles, or free portions of the cellules, this species approaches
G. patulus ; but these parts are less mucronate, and the angle between the
axis and the cellules in that species is much greater, and the cellules are
narrower. The general form of stipe, except in its peculiar curvature,
does not differ essentially from some others previously described ; but a
comparison of the form of the cellules, their proportionate dimensions, and
angle of inclination, will suffice to show its distinctive character.

EXPLANATIONS OF FiguRES OF GRAPTOLITHUS ARCUATUS, Hall.
Puate II.

6. A stipe of a small individual, more than usually curved.

7. A stipe having a process just above and opposite the radicle.

8. A larger stipe, the cellules very clearly preserved.

9. A specimen showing the stipes on both sides of the radicle, and preserving their
peculiar curvature very perfectly.

10. An enlargement of a portion of one of the stipes.

Formation and Locality.—Shales of the Quebec group ; Point Lévis.

9. GRAPTOLITHUS EXTENSUS, Hall.

Plate II, figures 11-16.
(G. extensus, Hall: Geological Survey of Canada, Report for 1857, page 132.)

Description.—Frond consisting of two simple linear very slender
stipes, which diverge at right angles to the direction of the minute radicle,
and lie in the same plane. Stipe near the radicle one fiftieth of an inch
in diameter, and at a distance of four inches from the radicle, one tenth of

GRAPTOLITES. 81

an inch in diameter. Fragments of single stipes have been observed,
having a length of six or seven inches, with a width not exceeding that given
above. Surface usually smooth; the strize formed by the cell-partitions
sometimes visible ; the back of the stipe somewhat thickened, and about
one fourth of the width occupied by the common body.

Cellules short and comparatively broad, very slightly curved ; about
twenty-four in the space of an inch, and making with the axis an angle
of about 40°. Margins of the aperture truncate, making an angle of
98° with the axis: one third or more of the cellule is free; and near the
radicle, one half of the length of the cellule is free. The partitions are
distinctly visible in well-preserved specimens; but in most instances they
are obscure.

In this collection, the specimens are mostly upon weathered surfaces of
the slate ; the substance is often partially removed, and no good impressions
are preserved. This species is most nearly allied to G. s¢mzlzs, but is always
more slender near the base: the serratures are more distinct in smaller
stipes, and the angle of the cellules with the axis is much greater ; while the
angle formed by the cell-aperture with the axis is much less than in that
one. Ji differs equally from the allied Kuropean forms, in some respects
approaching the G. sagittarius as represented by Geinitz (Graptolithen,
-ete., pl. u, fig. 4); but it has more the aspect of G. Wilssoni (fig. 17
of same plate). It differs essentially however from G. WVilssoni as repre-
sented by Barrande (Graptolites de Bohéme, pl. 1, figs. 16 and 17),
and from the figs. 19 and 31 of Geinitz, which our species never
approaches in any stage of growth. In our specimens we see the con-
nexion of the stipes with the radicle, and trace them continuously for four
or five inches; and in separated fragments, we have specimens six or seven
inches long. None of these offer an approximation in variations of form
and proportional distance of cellules, to those represented by Geinitz
as different phases of G. Milssont. We may add, that if such differences
exist in the same species, we have then no means of fixing the limits of
specific variation, or of determining the species among graptolites of this
character, from the separated fragments. The comparatively large number
of specimens in the Canadian collection affords good means of specific deter-
mination for many of the forms; and unless we could find upon the same
stipe, evidences of such variation, we should hesitate to consider the
different varieties as one species.

The G. Nilssont, as figured by Harkness (Quart. Jour. Geol. Soc., vol.
. vil, p. 62, pl. i), differs from our species, and more nearly resembles the

figures of Barrande.
a

82 CANADIAN FOSSILS.

EXPLANATIONS OF Figures or GRAPTOLITHUS EXTENSUS, Hall.
Puate II.

11. A single stipe more than four inches long, with the radicle and part of the

opposite stipe.
12. A fragment showing a part of the stipe on each side of the radicle, natural size.
13. The radicle and adjacent cellules, enlarged from fig. 12.
14. An enlargement of fig. 12 at a point about two inches from the radicle.
15. A fragment of a stipe where the cellules are distended by iron pyTiies: This
fragment may belong to a different species.
16. An enlargement from fig. 15.

Formation and Locality.—Shales of the Quebec group ; Point Lévis.

10. GRAPTOLITHUS PENNATULUS, Hall. (a. s.)
Plate III, figures 1-8 ; and Plate V, figure 9.

Description—Frond consisting of two stipes, which diverge rectangu-
larly, or are more or less ascending from a small radicle. Stipes narrow
at the base, gradually or rapidly increasing in width for about two thirds of
their length. At the base they measure not more than three or four hun-
dredths of an inch, and increase to one tenth of an inch in the narrower indi-
viduals ; while the widest observed is three tenths of an inch at one third of
the length from the base, beyond which point it is somewhat narrower. They
are all more or less contracted towards the distal extremity, curved on the
celluliferous side, and nearly straight on the back: the terminal cellules are
developed in a line nearly parallel with the axis. The proportion of the
stipe occupied by the common body is from one seventh to one fourth of
the entire width. The test is apparently smooth ; that of the back of the
stipe and partitions of the cells seems to be considerably thicker than the
outer walls of the cellules.

The cellules, when fully developed, are long, narrow, and curved up-
wards, making an angle with the axis of from 30° to 45° im different indi-
viduals at the base of the cellules, and as high as 70° on the outer part of
some of them; while the average angle, taking a line from the base to the point
of the cellule, is from 50° to 57°. The line of the aperture is curved : the
pellicle forming the cell-walls extends along the posterior side of the cell-
partition next in advance, the line of aperture making an angle with the
axis of from 110° to 120°; while the extremity of the denticle is
mucronate. ‘The fully-developed cellules have a length of eight times

GRAPTOLITES. 83

- their width; and in the narrower stipes, the length of the cellule is
about five times the width. There are from twenty-four to thirty-two
cellules in the space of an inch: (the specimen having thirty-two in
an inch is a young individual, in which the cellules are more crowded,
and not fully developed.) The apex of the denticle is vertically above
the base of the fourth or fifth cellule in advance, varying in the narrower
stipes to the third cellule in advance.

This species differs from all the others described, except G@. bifidus ;
and this it very much resembles in the young individuals. There is an
absence of pustules at the base of the cell-partitions, with a greater thick-
ening of these partitions, and the denticles are usually more mucronate.
If uniformity im the divergence of the stipes can be relied upon, this char-
acter will aid in distinguishing the species ; but this feature may vary from
accident, as In one specimen figured, which appears to have been broken in
one of the stipes. This species is remarkable for the great development
in the width of the stipes, which, in their extremely compressed condition,
have the appearance of feathers mbedded in the shale.

The specimens from which these figures have been drawn, present the
fossil in a very unsatisfactory condition; and farther collections may show
the necessity of separating some of the narrower forms under another
specific designation.

EXPLANATIONS OF Figures oF GRAPTOLITHUS PENNATULUS, Hall.
Puate III.

1, A young specimen with the minute radicle, the stipes diverging almost horizon-
tally, or rectangularly to the radicle.

2, A young specimen with one stipe entire, and a part of the other, less divergent
than fig. 1.

3. A single imperfect stipe of a young or half-grown individual, which is narrower
than usual.

4. A larger stipe, which is entire from the base to the apex.

5. A large or full-grown single stipe, which is nearly entire.

6. An enlargement to three diameters from fig. 4, showing the form and proportion
of the cellules, and cell-denticles.

7. An enlargement to the same degree as the preceding, from fig. 5.

8. A young specimen where the stipes are twisted near the base, giving an appearance
as if the serrations were on the outer or lower side in relation to the direction
of the radicle.

PLate V.

9. A single stipe of this species? The specimen is a large stipe, somewhat obscurely
preserved upon the surface of a slab of slate, with G. extensus, G. bryun-
oides, and Phyllograptus ilicifolius. It is from the same locality with
G. bifidus at Point Lévis. In the form of the stipe, and its gradual diminu-
tion towards the distal extremity, as well as in the absence of visible pus-
tules at the base of the cellules, it has the habit of G. pennatulus. Being
the only individual observed from this locality, and the resemblance to

G. bifidus being very close, I haye referred it with much hesitation to
G. pennatulus.

84 CANADIAN FOSSILS.

Formation and Localities—Shales of the Quebec group ; three miles
above river St. Anne, and at Pomt Lévis.

11. GRAPTOLITHUS BRYONOIDES,* Hall.
Plate IV, figures 1-11; Pl. III, figs. 11, 12 (2); Pl. VI, fig. 4 (?).

(G. srronorpss, Hall: Geological Survey of Canada, Report for 1857, page 126. Fucoides
serra, Brongniart, Végétaux Fossiles, vol. i, page 71, 1828.)

Description.—Frond consisting of four simple stipes, united in pairs at
their bases, and connected by a short funicle of variable length, from the
centre of which proceeds a minute pointed radicle. The stipes diverge at
various angles (dependent probably on distortion from pressure) ; narrow
at their origin, and abruptly expanding above, they acquire their full width
within the distance of three or four cellules, and maintain the same through-
out their length to near the distal extremity, which is somewhat abruptly
rounded and occupied by the partially-developed cellules. The full width
of the stipes in young individuals is often not more than one twelfth of an
inch, and in mature specimens about one seventh of an inch; the base
having a diameter of not more than two or three hundredths of an inch.
The common body occupies avery narrow space, and the solid axis is strongly
defined in the flattened specimens. The substance of the stipe or pellicle
is quite thin and apparently smooth, the only markings visible being the
oblique strize made by the cell-partitions.

Cellules elongate, of medium width, somewhat curved, and in the fully-
developed condition about four times as long as wide, making an angle
of from 40° to 50° with the axis; free for about one fourth of their length ;
about from twenty to twenty-four in the space of an inch, varying in differ-
ent individuals and in different stages of growth. Aperture curved,
making an angle of about 110° with the axis; the cell-denticles pointed,

* T have little doubt that this species is identical with Fucoides serra of Brongniart
(Vég. Fossiles, p..70, 1828). The locality of that species is “‘ Pointe Levi prés Quebec,”
which is the same with that of G. bryonoides: and the figures of Brongniart correspond
with figs. 9 and 10 of plate 4 of this memoir. The Fucotdes dentatus of the same
author is also probably identical with G. pristiniformis of this memoir, being from the
same locality. It is only since these descriptions have been in print, and published
references made to them, that I have discovered this identity, or I would have pro-
posed to substitute the specific names of Brongniart for those given by me in 1857.
I take the first opportunity of making the correction.

GRAPTOLITES. 85

and slightly curved forward: cell-partitions usually well marked, and
near the base, making a much less angle with the axis than towards the
aperture.

When the funicle is broken, this species sometimes occurs like the bi-
brachiate forms, as in fig. 5 of plate iv, and in that condition bears some
resemblance to G. nitidus ; but its stipes are wider, its habit more robust,
the cellules more curved, making a greater angle with the axis; the den-
ticles coarser and more equilateral, and usually mucronate or sub-mucro-
nate. No pustules at the base of the cell-partitions, as in G. nitedus,
have been observed in this species. There is also a resemblance between
G. patulus and this species ; but in that one the stipes are usually more
slender, the denticles more mucronate, the curve of the aperture much
greater, and the cells make a much greater angle with the axis.

This species is associated in the same shales with Gt. nitidus, G. exten-
sus, G. constrictus, and Phyllograptus tlicifolius. I have united with
this species the specimen represented in figs. 9 and 10, of plate iv, though
it presents variations in some of itscharacters. A small portion of one of the
stipes near the base of this shows a number of cellules or serratures equal
to twenty-six in the space of an inch. Its affinities are more nearly with
G. bryonoides than with any other; and having but this individual, I refer
it for the present to that species.

EXPLANATIONS OF FIGURES OF GRAPTOLITHUS BRYONOIDES, Hall.

Pirate IV.

1, 2, 3. Young individuals of this species.

4, An older individual.

5. A young specimen preserving two of the stipes, the funicle having been broken.

6. An enlargement from fig. 1, showing the radicle, funicle, and origin of the four
stipes, with a few of the earlier cellules.

7. An older and larger specimen.

8 An enlargement showing the character and proportions of the cellules.

9. A small individual, preserving the four stipes in part, which are somewhat more
slender than the usual forms of this species.

10. An enlargement of the base of the specimen, showing the cell-denticles on one
of the stipes, and a proportionally longer funicle than in fig. 8.

11. An extremely elongated stipe, the lower end showing the commencement of
growth; the distal extremity is broken.

Puate III.

11. A fragment of a stipe from the rough shales, with Phyllograptus ilicifolius. In the
character of the cell-denticles it resembles the specimen pl. iv, fig. 9, and
with that one may constitute a distinct species.

12, An enlargement of a part of the specimen fig. 11.

F

86 CANADIAN FOSSILS.

Puate VI.

4, A frond in which three of the stipes, and the base of the fourth, are preserved. The
specimen shows some peculiarity in the union of the parts by the slender
funicle.

Formation and Localities—Shales of the Quebec group ; Pomt Lévis,
Grds Maule, and river St. Anne.

12. GraptotitHus Bieaszyti, Hall.

Plate XVI, figures 22-30.

(PHYLLOGRAPTUS SIMILIS, Hall: Geological Survey of Canada, Report for 1857, page 140,
Compare Didymograptus caduceus, Salter: Quarterly Journal of the Geol. Society,
vol. ix, p. 87.)

Description.—Frond broadly oval or sub-oval, consisting of four some-
what semi-elliptical stipes, which are nearly straight or slightly curved on
the non-celluliferous margin, and broadly curved on the celluliferous side ;
all closely united at the base in a radicle (?), and from which they are
abruptly recurved. These stipes are more frequently distinct at the
apex, While in some individuals they are in contact or apparently
united at that pomt, but always separated in the centre for a dis-
tance of three fourths their length. Entire length of specimens from
four to six tenths of an inch, and width three tenths of an inch, exclu-
sive of the denticles. The individual stipes, in the centre of their length,
are twelve hundredths of an inch wide. Radicle undetermined. Cellules
from thirty-two to thirty-six in the space of an inch, narrow at the base,
gradually ascending and curving outwards, except those near the base,
which are recurved: cell-margins curved, and extended in mucronate points,
which are the continuation of the cell-partitions. Test thin and smooth,
with the exception of the cell-partitions.

This species presents a great variety of aspects, and the most critical
examination has left some doubt as to its original mode of growth. The
more perfect specimens are broadly oval, the diameters about as three to
four; and where the stipes are apparently conjoined, at the two extremi-
ties, there is a vacant space in the centre (extending about three fourths of
the length, and from six to eight hundredths of an inch in width), except
that some portions of one or both the other stipes are visible. In one or
two individuals, there is a linear body extending longitudinally through this
space, which may have been originally the axis; but its relations cannot

GRAPTOLITES. 87

be determined. Examinations have failed to exhibit any satisfactory
evidences of the existence of a radicle. In most of the specimens the
stipes are united at one extremity and free at the other; while their curva-
ture is such, that if continued, they would meet. In these specimens the
four stipes are often distinctly seen, two usually showing the non-celluli-
ferous margins; while sometimes three, and rarely the four stipes show the
celluliferous margins.

The individuals are extremely numerous, but in almost all instances the
characters are more or less obscured by the stipes being slightly separated
by intervening lamin of slate, or by the weathering of the surface. On
a single piece of slate of about a foot long by six inches wide, there are
more than one hundred individuals ; but nearly all of these are so obscured
by weathering, that they afford little means of determining the characters or
mode of growth. In the whole collection, there are not more than one or
two species of which the individuals are more numerous than of this, and
in no other are the characters so indistinct.

From the deep curving cellules and broad stipes, which are often appa-
rently conjoined at the apex, I have supposed that they may, at some period
of growth, have been jomed along the non-celluliferous side for the entire
length. On this account, I had originally referred the species to the
genus Phyllograptus.

In some of the specimens, where two of the stipes are spreading, and
show the celluliferous margins, the non-celluliferous face of a third stipe
often stands vertically between them, like a stem. These forms resemble
the Graptolithus caduceus of Salter, which was obtained by Dr. Bigsby
from ‘‘ the Lauzon Precipice,” * and I have hesitated in regard to making
of these a new species. The name of Phyllograptus similis was applied to
such forms as figs. 26, 29, and 30; but when it became apparent that all the
other varieties of form must be referred to the same, it was necessary to
remove it from that genus; and since I had already named another spe-
cies Graptolithus similis, I take great pleasure in dedicating this to Dr.
J.J. Bigsby, who early explored the geology of the northern portion of
our continent, and who, in later years, has never ceased to interest himself
in American geology, and to aid in its progress.

EXPLANATIONS oF Figures or Graprouiruus Biessyi, Hall.
Prats XVI.

22,23, and 24 illustrate a common condition of this species, where two of the
divisions show the lateral faces, while the non-celluliferous edge of a

* This locality is probably the same with that which has furnished the greater part
of the graptolites here described; the precipitous heights of Point Lévis being in the
seigniory of Lauzon.

88 CANADIAN FOSSILS.

third division is seen lying nearly vertically in relation to these. The
fourth division has been broken off in the separated film of slate.

25. A specimen showing the lateral faces of two divisions. Below these, in the
shale, are seen the non-celluliferous edges of the two other divisions.

29 and 30 show a still closer arrangement of the parts, and the contiguity of
the non-celluliferous edges at the apices, which are scarcely perceptibly
separated in the shale.

26. An individual where the apices of the divisions are in contact, either conjoined,
or accidentally so placed, with a narrow space in the centre. In obscure
specimens it is difficult to separate such forms from Phyllograptus.

27. An individual where the divisions are equally spreading: one of them presery-
ing only the base of the stipe.

28. The same enlarged.

Formation and Locality.—Shales of the Quebec group; Point Lévis.

13. GRAPTOLITHUS DENTICULATUS, Hall.

Plate IV, figures 12-16.

(G. DENTICULATUS : Geological Survey of Canada, Report for 1857, page 132.)

Description.—Frond consisting of four simple stipes proceeding from a
simple radicle. Stipes slightly ascending at their origin, but immediately
and strongly recurved, again bending gently upwards from the middle to-
wards the extremities ; slender at the origin, and gradually expanding to a
width of from nine to twelve hundredths of an inch (exclusive of the den-
ticles), which it almost uniformly maintains. Substance of the stipe ex-
tremely thin, and marked on each margin by a linear filiform ridge, like the
ordinary solid axes of these bodies. In the impressions left on the removal
of the substance, each margin shows a continuous filiform groove in the
place of the thickened or solid margin of the stipe; the groove on the
celluliferous or denticulate side being much stronger than that on the back
of the stipe. Surface apparently smooth throughout. Cellules consisting
of small mucronate equilateral denticles, placed vertically on the margin
of the stipe, and rising immediately from the thickened solid edge: den-
ticles spreading below, slightly curving, and united at their bases by a thin
pellicle ; varying in their distance on different parts of the stipe, and
apparently in different stages of growth ; sometimes twenty-four in the space
of an inch, near their origin, while elsewhere the average number is from
eighteen to twenty ; the lower numbermarking the strongest stipes measured.

This species is very peculiar, differing not only from the associated
species, but from all others in the arrangement of its denticles.

GRAPTOLITES. 89

The specimen originally described under this name is a fragment (pl. iv,
fig. 14), consisting mainly of an imprint in the shale, the substance
of the fossil being preserved in some parts. ‘The solid axis on the
denticulate margin is clearly defined in the impression, and in some
places the substance remains, and is expanded at each denticle on the upper
side so as to occupy the base of each depression. The cellules terminate
in so minute a point that no aperture is visible ; but in a longitudinal divi-
sion of some of them, they appear to have been hollow tubes. The back of
the stipe is clearly marked (as is usual in the graptolites) by the presence
of a distinct solid axis, which in no respect differs from the ridge on the
opposite margin, except that the latter extends into the base of the cellules.

A further study of the collection has shown that some obscure imprints
in weathered shale are of the same species. ‘These imprints, at a few points,
retain portions of the pellicle, and the form of the cellules is well preserved ;
they reveal moreover the mode of growth, as shown in figs. 12 and 13
of pl. iv; thus indicating. their relation im this respect to G. bryonoides
andG. quadribrachiatus. The recurved position of the stipes is a feature
of G. bryonoides, but less extreme than in this one. This species may be
readily identified by the pointed cellules, vertical to the axis, which appear
to be entirely separated from the common body, except in well-preserved
portions, where in a few examples they are shown to be connected at the
base by a continuation of the cell-wall above the solid axis.

EXPLANATIONS OF FIGURES OF GRAPTOLITHUS DENTICULATUS, Hall.
Puate IV.

12. A small imperfect specimen, preserving three of the stipes.

13. A larger and more nearly entire specimen, showing the four stipes. Their junction
at the base is not quite satisfactorily shown.

14. A part of a single stipe, in which the cellules are well shown on one part; while
they are compressed and nearly obliterated on the left of the curve.

15. An impresssion of a part of a stipe which is nearly straight; the imprint of the
axes or thickened margins is not defined.

16. An enlargement from figure 14, showing the form of the cell-denticles, and the

strong marginal axes ; one portion represented with the substance remaining,
and the other as an imprint.

Formation and Locality.—Shales of the Quebec group; Point Lévis.

90 CANADIAN FOSSILS.

14. GRAPTOLITHUS FRUTICOSUS, Hall.

Plate V, figures 6-8; and Plate VI, figures 1-3.
(G. FruTicosus : Geological Survey of Canada, Report for 1857, page 128.)

Description.—Frond consisting of two pairs of ascending and slightly
curved stipes arising from the two sides of a long slender radicle, which is
divided above: the stipes are celluliferous on the inner or adjacent mar-
gins, little divergent at the bifurcation, and continuing for a half or two
thirds of theirlength nearly straight ; above this they curve gently outwards,
presenting, when not distorted, a very beautiful and symmetrical form. The
stipes gradually increase in width from their origin, being at the base one
fiftieth of an inch, and in the widest part one twelfth of an inch, exclusive
of the denticle. The proportion of the stipe occupied by the common body
is extremely narrow.

Surface smooth, or with scarcely visible striz: at the lines of the cell-
partitions: axis very slender; test thin and fragile. Radicle half an inch
in length. Cellules short and broad, making an angle with the axis of
about 38°; the length from two to three times the diameter, and free from
a third to a half of the entire length, according to their development ;
variably curving in different parts of the stipe. Aperture wide, apex pointed,
scarcely mucronate, and sometimes acutelyrounded. About fifteen cellules
in the space of an inch, varying slightly in different parts of the stipe: near
the base the serrature or length of the denticle is equal to the width of the
stipe, while in the wider portions it is less than half the width of the stipe.

This species, in all the examples that have been observed, is a very
distinct and easily recognized form. Wherever the radicle is preserved,
it is longer than in any of the other species: this part bifurcates above,
and the divisions, moderately diverging, represent what I have termed the
funicle in the quadribrachiate forms; from each extremity of this, the
stipes originate. All the divisions are little divergent, and the frond grows
upwards like a small shrub. The form of the cellules differs from other
species here described, except perhaps G. indentus, which is readily dis-
tinguished in its mode of growth, as well as by other characteristics.

EXPLANATIONS OF FiguRES OF GRAPTOLITHUS FRUTICOSUS, Hall.
PuaTe V.

6. A small individual with the radicle and extremities of the stipes broken off.

7, Anenlargement from fig. 6. The serratures are either imperfect or shrunken,
and do not present the characters seen in better-preserved specimens.

8. An individual nearly entire, but badly preserved in the outline of its parts.

GRAPTOLITES. 91

Puate VI.

1. A fragment showing two of the stipes entire, and the bases of two others ; the
radicle extending to the margin of the specimen.

2. A specimen preserving three of the stipes, one of them entire, and showing some
irregularities in the bifurcation where the one is broken off.

3. Anenlargement of the right-hand stipe of the specimen fig. 1.

Formation and Localities.—Shales of the Quebec group; at the upper
end of Orleans Island, and three miles above river St. Anne.

15. GRAPTOLITHUS QUADRIBRACHIATUS, Hall.
Plate V, figures 1-5; and Plate VI, figures 5, 6.

(G. quapripracHtatus, Hall: Geological Survey of Canada, Report for 1857, page 125.)

Description.—Frond composed of four simple undivided stipes arranged
bilaterally, or two proceeding from each extremity of the funicle. Stipes
slender, very gradually increasing in width from their origin, as far as traced ;
usually straight, sometimes slightly curved ; width from two to four hun-
dredths of an inch at the base, and im the most perfect examples, nine
hundredths of an inch at the widest part. The back of the stipe is marked
by a filiform axis, and there is scarcely more space occupied by the common
body. ‘Test thin, though well preserved in the finer shales. Surface of
cell-walls distinctly striated parallel to the apertures, and the cell-partitions
visible nearly to the back of the stipe.

Cellules narrow, scarcely curving, and slightly expanding towards the
aperture, making an angle with the axis of about 38°; the length equal
to about four diameters, the free portion being from one third to two
fifths their entire length. The margin of the aperture is nearly straight,
or very slightly curved, making an angle of from 95° to 100° with the
axis. The number of cellules in the space of an inch is from twenty-two to
twenty-four, dependent on the distance from the origin of the stipe, and on the
degree of development. The apex of the denticle, or posterior point of the
aperture, is a little below the base of the second cellule in advance. Cell-
partitions thin, and usually not well preserved.

This species, when entire, is readily distinguished from G*. bryonotdes
by its straight and more slender branches, and by the general aspect and
expression of the fossil; it has only a remote similarity with the other
quadribrachiate forms. In separated or double stipes it bears some

92 CANADIAN FOSSILS.

resemblance to G. arcuatus, except that it is less curved, and the form of
the cellules is distinctive. From the other bibrachiate forms, it is very
readily distinguished on comparing the form of the cellules.

I had heretofore regarded this species as possessing a disc, like G.
crucifer and others ; but on examination of all the specimens which can
be satisfactorily identified with it, not one has showna disc. The discs with
four stipes, which are broken off so close that no serratures are visible,
cannot be satisfactorily identified with this or any other species, and are
therefore left in doubt at this time. They may be regarded as belonging
to G. crucifer, or to the young of G. Headi.

EXPLANATIONS OF FIGURES OF GRAPTOLITHUS QUADRIBRACHIATUS, Hall.
PLATE V.

1. A large specimen with stipes vertically compressed.

A young specimen in which one of the stipes appears to be subdivided.

8. An individual with stipes a little curved, the back of the stipe visible, and showing
no serratures.

4. A frond with one of the stipes broken off; one showing the cellules and distinct
striz parallel to the cell-partitions, while the other two are turned so as to
obscure the cellules.

5. An enlargement from fig. 1: the stipe has been vertically compressed, causing
the cellules to show a less angle with the stipe than in the normal condition.

PuaTeE VI.

5. A frond preserving one stipe partially entire, and others broken off: the funicle
and radicle-point are well preserved.

6. An enlargement from the specimen fig. 5, showing the form and proportion of

cellules in their more perfect preservation, with the striz parallel to the cell-
margins well preserved.

Formation and Locality.—Shales of the Quebec group; Point Lévis.

16. GRAPTOLITHUS CRUCIFER, Hall.
Plate V, figure 10.
(G. crucirer: Geological Survey of Canada, Report for 1857, page 125.)

Description.—Frond composed of four simple, strong stipes, united at
their base by a small thickened disc. Stipes strong at the base ; the two
pairs connected by a short funicle, which is without a visible radicle.

GRAPTOLITES. . 93

The specimen lies with the celluliferous face downwards, and the stipes
near their origin present only the back, which shows them to be strong,
and of considerable substance, and measuring at that point five hundredths
of an inch in width. Extending from the disc, the stipes are gradually
turned on one side, and in their greatest width measure seventeen hun-
dredths of an inch in diameter, including the denticles. Cell-denticles
sub-mucronate, rising above the margin almost vertically; about twenty-
two in the space of an inch.

This species preserves the general form of G. quadribrachiatus; but
is more robust, and the stipes are united in a central disc. The specimen
is upon a weathered surface, and very obscure; the characters being
drawn from the general form and proportions. The cell-denticles are
visible on a part of three of the stipes, but we are unable to trace the
direction or existence of any cell-partitions. The denticles in their
prominence resemble those of G. denticulatus ; and broad stipes of G.
bifidus have likewise some analogy with this species; but as our only
specimen is imperfect, no minute comparisons can be made. It is a
smaller species than G. Headi, but with a comparatively broader stipe,
and more erect cell-denticles. In G. crucifer the disc is quadrilateral,
with concave sides, and is somewhat oblong; while in G. Headi the disc
is larger and essentially square, the margins being very nearly straight.

In the specimen described, the disc is without markings, as are also some
other discs which may belong to this species; while a single specimen
shows concentric strize parallel to the margins.

EXPLANATIONS OF Figures OF GRAPTOLITHUS CRUCIFER, Hall.
PuatTE VY.

10. View of the specimen from which the description is drawn.
13. The dise of a young individual probably of this species.

Formation and Locality—Shales of the Quebec group; Point Lévis.

17. GRAPTOLITHUS ALATUS, Hall.
Plate VI, figure 9.

(G. auaTus: Geological Survey of Canada, Report for 1857, page 127.)

Description.—Frond consisting of four stipes (probably simple) ; their
bases united in a thickened disc, the central portion of which is about seven

tenths of an inch in extent, and uniting to the stipes continues along their

94. CANADIAN FOSSILS.

margins for an inch and a quarter, giving an extremely alate appearance.
Stipes strong, angular on the back or non-celluliferous margin: test
thick: cellules unknown.

The only specimen known consists of the dise and parts of three of the
stipes ; the longest one extending a little beyond the limits of the dise, or
so far that the alation produced by the disc is not distinguishable. The
lower or non-celluliferous side is presented to view, and we know nothing
of the extension of the stipes, nor of the cellules. It is probably one of
the simple-stiped species, and of rare occurrence, since no other specimens
are known which can be identified with it.

EXPLANATION OF FiGuRE OF GRAPTOLITHUS ALATUS, Hall.
Pirate VI.

9. The specimen represented as it occurs on a fragment of slate. The back of the
stipes shows faint indentations, but they are made too strong in the
engraving.

Formation and Locality.—Limestone of the Quebec group; Point
Lévis.

18. Grapronitnus Heapr, Hall.

Plate VI, figure 8.

(G. Hzant, Hall: Geological Survey of Canada, Report for 1857, page 127.)

Description.—Frond robust, four-stiped ; the stipes in pairs, jomed by
a short funicle at the base, and united in a broad thickened quadran-
gular disc. Stipes strong, somewhat alate near the base from the exten-
sion of the substance of the disc for a short distance along their margins,
extremely elongate, and extending in a nearly direct line towards their
extremities ; celluliferous on one side. The width in a transverse direc-
tion, at the junction with the disc, is six hundredths of an inch; and m
the widest portion, fourteen hundredths of an inch. Disc quadrangular,
nearly square, slightly extended along the stipes, with straight margins in
the spaces between; measuring in the specimen examined, one inch and
one eighth in each diameter across the centre.

Cellules elongate, distinctly curved, making with the axis an angle of
about 50°; length four or from four to five times the diameter at the
aperture: denticles sub-mucronate, sub-erect, about twenty-four in the
space of an inch. The margin of the aperture is apparently curved ; its

GRAPTOLITES. 95

angle with the axis cannot be satisfactorily determined from the specimen.
Cell-partitions strong.

The specimen from which this description is drawn, consists of the dise
and a part of two stipes, the other two being broken off just beyond the
disc ; one of the stipes measures nearly seven inches from the centre.
When the disc is preserved, this species can be readily distinguished. Sepa-
ated stipes bear a near resemblance to G. bryoncides; but the abrupt,
narrowing at the base of the stipes, and the shorter denticles, character-
ize G. bryonoides. In the specimen described, we have little more than
an impression of the stipe, and this is ina coarse material ; so that there still
remains some obscurity regarding the surface of the test, and the exact
form of the cellules and their apertures.

EXPLANATION OF Figure or GrapTouitHus Heapt, Hall.
Puate VI.

8. A representation of the specimen of the natural size, and as it occurs on the
surface of the stone. (The upper separated portion of the stipe is placed
a little lower in the figure than it is on the stone, in order to bring it
within the dimensions of the plate.)

Formation and Locality—Shales of the Quebec group ; Point Lévis.

19. GRAPTOLITHUS OcTONARIUS, Hall.

Plate X, figures 1, 2.

(G. octonarius, Hall: Geological Survey of Canada, Report for 1857, page 124.)

Description.—Frond consisting of eight stipes uniting in pairs at the
base, and each pair again united in a similar manner, making one half the
frond ; the two parts are joined by a funicle, in the centre of which is a small
rootlet. The two sides are equal and symmetrical, giving a bilateral arrang-
ment to the whole. Stipes narrow and rounded at the base, having a diam-
eter of from two to four hundredths of an inch below the bifurcations ; in the
figured specimen, at a distance of from one half to three fourths of an
inch from the base, they are eleven hundredths of an inch wide.

Solid axis distinct, the common body occupying a very small proportion
of the whole width. Cellules elongate, distinctly curved, expanding ; making
an angle of from 30° to 35° with the axis; the aperture is twice as wide as

96 CANADIAN FOSSILS.

the base; the free portion is a little more than one third of the entire
length. Margin of aperture slightly curved in the mature cell, and more
distinctly in the young, making in the former an angle of 120° with the
axis. ‘The denticles are pointed, scarcely sub-mucronate, twenty-four in
the space of an inch. Cell-partitions strongly marked, the line of sepa-
ration extending nearly to the back of the stipe.

In this species the stipes resemble those of G. bryonotdes in their width,
form, and proportion of cellules and cell-denticles ; but the number of
stipes in entire specimens is a characteristic feature. In single stipes or
in pairs of G. octonarius, there is, as shown in the figures, a longer space
at the base without cellules, and in the double or quadruple stipes the differ-
ence of character is obvious. In the union of the two stipes in G. bryonoides,
the funicle proceeds from the back of the stipes, or the non-celluliferous
side; while in the union of two stipes in G. octonarius, the continuation below,
uniting with the adjacent pair, is not from the back of the stipes alone, but
the two appear to be united laterally and diverge at a different angle ; as
will be seen on comparing the figures of the two species. Fragments of
G. patulus bear some resemblance to this species, but a comparison shows
important differences.

EXPLANATIONS OF FIGURES OF GRAPTOLITHUS OcTONARIUS, Hall.
PuatTe X.
1, A specimen of natural size, much broken and distorted from pressure.

2. An enlargement from the preceding figure.

Formation and Locality.—Shales of the Quebec group; Grds Maule.

20. GRAPTOLITHUS OCTOBRACHIATUS, Hall.

Plate VII, figures 1-7; and Plate VIII, figures 1-4.

(G. ocrosracuiatus, Hall: Geological Survey of Canada, Report for 1857, page 122.)

Description.—Frond consisting of eight simple stipes, which are united
in pairs at their bases: these have their origin from a short funicle,
which proceeds from a radicle in the centre. Each extremity of the funicle
is divided, and these divisions are again bifurcated, giving origin to the
four stipes on each side, which are thus bilaterally arranged. The funicle
and bases of the stipes are united in a broad thickened disc, composed of
the same substance as the other parts of the fossil: disc octagonal, the

GRAPTOLITES. 97

sides concave between the stipes, and the angles extended upon the mar-
gin of the stipes. Stipes robust, equal, linear, elongate, proceeding in
right lines from the centre.

Within the disc or near it the stipes measure five hundredths of an
inch in width; and beyond this the width, including the serrature, is thir-
teen hundredths of an inch. Test thick: the common body occupies
sometimes about one third of the entire width. Cellules long, strongly
curved, the breadth at the aperture three or four times as great as at the
base ; length a little more than three times the width at the aperture ;
making an angle with the axis of 20° near the base of the cell, and from
52° to 50° near the aperture. Margin of the aperture nearly straight,
making an angle with the axis of 105°; and sometimes, when compressed,
still greater. Denticles obtuse, about nineteen or twenty in the space of
an inch.

This species is remarkable for its extremely elongate stipes and strong
central disc. Some of the largest individuals, with the stipes expanded,
have extended over an area of at least sixteen inches in diameter. The
stipes are extremely robust, and in their original state appear to have
been quadrangular ; the measurement across the back of the stipe, when
flattened, being seven ninths as great as the lateral measurement of the
flattened stipe below the cell-denticles. The size of the stipes is not
greater than in G. Headi; but these have a more rigid aspect, and are
readily distinguishable when the cellules or cell-denticles can be seen.

All the specimens, with one exception, present the exterior or non-cel-
luliferous side at the base; the disc and stipes adhering to the stone on the
celluliferous face; so that it is only towards the extremities of the
branches, where they are turned on one side, that the full width or form of
the cellules can be seen. An impression of ashort fragment of the cellulifer-
ous surface of one of the stipes shows strong deep indentations. The cel-
lules vary but little in their distance or approximation, from seventeen to
twenty in the space of an inch being the extremes of variation observed.
The disc is not uniform in its proportions, nor regular in form, nor does it
always appear to bear the same proportion to the strength of the stipes; it
has sometimes a very symmetrical octagonal form: its substance is often con-
siderably thickened and striated parallel to the margins, which are thinner,
attenuating from the centre. The cellules are subject to variation from
the direction in which the stipes have been compressed, and in this respect
show a greater variety of appearances than any other species in the col-
lection.

This species exhibits some differences in its mode of growth, and the num-
ber of stipes is not invariable. One specimen presents but seven stipes ; the
centre, funicle, and divisions on one side being of the normal character,
while on the other, one division of the funicle does not bifurcate, but

98 CANADIAN FOSSILS.

continues as a single stipe, giving seven as the entire number of stipes,
with a small seven-sided dise. In another individual we have five stipes only ;
the funicle and disc exist as in the others, but the subdivisions have taken
place only on one side, while on the opposite the stipe continues simple.
The presence or absence of the central disc, however, cannot be reli2d upon
for specific or other distinction, sce both im this species and G. Logant
we have specimens of the same species, preserving their characters in all
respects, except the disc. In the specimen fig. 2, plate viii, we have the
central portion of an individual in which there is no evidence of the dise
having existed. In its form and mode of division it corresponds in all
respects with those specimens possessing the discs; and as it occurs in the
same association, we cannot suppose it otherwise different.

In its long linear stipes, this species resembles G. sagittarius (Hall,
Pal. New York, vol. i, plate 74, fig. 1; perhaps not the European spe-
cies of that name); but the branches are stronger and the serrations
coarser ; it is moreover associated with a group of species, all of which are
quite distinct from the New-York species with which G. sagittarius occurs.

EXPLANATIONS OF FIGURES OF GRAPTOLITHUS OCTOBRACHIATUS, Hall.
Prats VII.

i. A large individual preserving two of the stipes to the length of eight inches, and
another to nearly the same extent, while the rest are broken off at less
distances from the disc. The flexibility of their substance is well shown in
the recurved stipe at the left-hand side of the figures. Although this speci-
men preserves the most extended stipes of ‘any in the collection, the dise
is smaller than in several of the other specimens.

2. The exterior of a large disc of this species, with the stipes broken off a little
beyond its margin. The two longer portions are so turned as to show the
cellules.

A portion of a large disc, showing the exterior or non-celluliferous face of the
frond, and preserving portions of four of the stipes.

4. A frond with the stipes broken off at different distances from the centre. The
substance of the disc or cup is imperfect,—a condition which apparently
existed while the body was in a living state.

5. An enlargement from one of the stipes at c, looking upon the apertures of the
cellules, which are somewhat compressed.

6. An enlargement from the same at 6, where the substance is laterally compressed.

7. An enlargement from the same, where the substance is obliquely compressed at a.

Figs. 5 & 7 are taken from casts made in the impressions left by removal of the sub-
stance of the graptolite.

(oN)

Priate VIII.

1. A symmetrical frond preserving parts of all the stipes, two of them apparently
almost entire; several of them had been abruptly bent before being im-

bedded in the stone.
2. A frond preserving eight stipes, but without a disc. The specimen does not afford

any evidence that a disc has ever existed.

GRAPTOLITES. 99

3. <A frond with small disc and somewhat slender stipes. One side preserves the
usual character of four stipes, while the other has but three.

4. A frond which is abnormally developed; one side preserving the four stipes with
the disc, while on the other side the funicle is apparently extended in a single
stipe only.

Formation and Locality.—Shales of the Quebec group; Point Lévis.

The G. Logani is the only species with numerous unbranched stipes
which we know of at this time in the Quebec group. All the other species
with more than eight stipes, have them branched beyond the commence-
ment of the cellules. In the Hudson River formation, however, we have
a single analogous species, the G. multifasciatus. In that one the stipes
are forty or more in number, and are apparently simpler after they
become celluliferous.

In the progress of development of the graptolites of this type, we have
traced them through the two, four, and eight-stiped forms. Those with
two stipes have never shown the cup or disc ; while some of the latter
two forms have discs, and others apparently never possessed this appen-
dage. ‘The subdivision into stipes appears to go on by a regular duplication
of the parts; and the stipes in perfect forms are bilaterally arranged,
beginning with those having two; which proceed, one on each side, from a
rootlet. With the exception of G. fruticosus, the four-stiped forms origi-
nate from a minute radicle; while on each side of this centre, the body
extends a short distance in the funicle, which is not celluliferous ; and then
subdivides equally, no cellules occurring below the division. In the next
form, the funicle is divided at cach extremity as before, and again divided
or bifurcated below the origin of any cellules. Were this mode of sub-
division to continue, the next step in the development would give us sixteen
stipes ; but we have no form of this kind in the collections.

Tn the next form, with simple stipes, we find the G. Loganz, which pre-
sents a wide variation in the number of stipes; so varied indeed that the
two extremes might, if examined separately and without the intermediate
forms, be regarded as two distinct species. ‘The variation in the number of
stipes in this species extends from eighteen to twenty-five : some divisions
of the funicle are equally, and others unequally developed in the number
of stipes which proceed therefrom.

100 CANADIAN FOSSILS.

21. Graprotitaus Loeant, Hall.

Plate IX, figures 1-9; and Plate XI, figure 7.
(G. Logant: Geological Survey of Canada, Report for 1857, page 115.)

Description.—Frond composed of numerous slender simple stipes, sub-
equally disposed on the two sides of their origin, or of the minute point mdica-
ting the radicle. All these, in their perfect condition, have their bases
embraced within a broad disc. Radicle sometimes well marked: funicle
short, simple for about three sixteenths of an inch, when it is divided at each
extremity, the divisions diverging at an angle of 150° or more. Each division
is again subdivided with more or less regularity, and always near the base,
until there are from eighteen to twenty-five simple stipes radiating from the
central disc. ‘There are rarely more than three bifurcations after the first
division of the funicle, and these all take place within the limits of the
disc. No cellules are visible on the stipes below the last bifurcation,
though they do occur within the limits of the disc. On the inner or
celluliferous side of the disc, the divisions of the funicle, and the bases of
the stipes beyond, are grooved along the centre. The disc is from one to
nearly two inches in diameter in different individuals, and with sides cor-
responding to the number of stipes, between which the margin is concave.
The substance of the disc is corneous like that of the stipes, extremely
thin, though composed of double walls; somewhat thickened near the
centre, and forming only a thin translucent pellicle towards the margin.
The surface is usually and perhaps always smooth in the centre; while
towards the margin, and parallel with it, are fine strize of growth.

The transverse diameter of the stipes, within the limits of the dise, is
from two hundredths of an inch at the base to four hundredths of an inch
at its outer margin. The vertical diameter, including the cell-denticles, is
six hundredths of an inch. The stipe is thickened on the back, and about
one fifth the width is occupied by the common body. The full width of
the stipe is attained at about two inches from its origin. Some of the
stipes have been traced for seven and a half inches from the centre of the
disc, and their extremities are still imperfect. The cellules are short narrow
and straight, making an angle with the axis of about 35°, and free for about
two fifths of theirlength, which is less than three times the diameter of the
aperture. The margin of the aperture makes an angle of from 90° to 95°
with the axis: denticles acute, from twenty-two to twenty-six in the space
of an inch; the prevailing number being twenty-four. Partition-walls
thin, and obscurely marked on the surface of the stipe.

This species, when the form is entire, is readily recognized by its numer-
ous simple elongated stipes. The separated central portions, whether

GRAPTOLITES. 101

with or without the dise, may be known by the short funicle, and the numerous
subdivisions near the centre. The stipes differ from those of any other species
in their proportions, and the form of the cellules and denticles. In these
separated parts there is some resemblance to G. arcuatus; but that
species has the stipes more curved, with a different form of cell-denticle, and
is moreover marked by the frequent occurrence of the minute radicle
attached to the separated stipes, as well as by the presence of cellules
nearer to the origin of the latter.

The great variation in the number of stipes shown to occur in G.
Logant, as well as what occurs in a lesser degree in G. octobrachiatus, is
sufficient evidence that strict specific characters cannot be founded on this
feature alone, im species where the stipes are numerous. From what we
are able to observe, it would appear that the disc of G. octobrachiatus
extends itself with the age of the individual ; though in G. Logani there
is no perceptible difference in the width of the stipes near the base, whether
the discs are larger or smaller. In those specimens of this species which
are without the central disc, or where this part may have been removed,
the stipes are always more slender towards the base than when they are
embraced within the central disc.

The margins of the disc are slender, and sometimes found broken between
some of the stipes, without injury to the rest of the body. The parts so
broken assume the same outline as if entire, and may probably have been
afterwards extended to correspond with the other portions. This feature is
seen in plate IX, fig. 4, where a specimen preserving half of the disc
shows that in three spaces between the stipes the disc had been partially
broken away, and appears to have been in process of reproduction.

In specimens showing the inner side of the frond, we find a distinct groove
marking the centre, the funicle, and the bases of the stipes: this is seen
whether the disc is preserved or not, and appears to be an organic feature.
This groove, corresponding to the central axis, likewise extends for some
distance along the celluliferous portion of the stipe; and the indentation,
being thus interrupted along the centre, is shown more strongly on each
margin, appearing like a double indentation or serrature.

On the opposite side of the frond, when well preserved, the stipes near
their bases, often appear to have a double axis, or an elevation on each
side. This feature seems to be due to pressure, or to the filling of the
tube on the two sides, while the centre has been contracted. It is clearly
an accidental feature, probably dependent on the nature of the surrounding
material, at least in part, smce some specimens from their origin are full
and round on the back of the stipes.

G

102

CANADIAN FOSSILS.

EXPLANATIONS OF Ficurss oF GrapToLitaus Loeant, Hall.
Puate IX.

A specimen of slate, preserving portions of three individuals, (two only given
in the illustration.) The disc had probably been removed by maceration
before they were imbedded, but the stipes are preserved to a length of
more than seven inches. It does not appear that this exhibits the entire
skeleton : the stipes were originally longer. The serrated margins are not
always shown at equal distances from the centre; but this is due to
accidental position, some stipes showing the exterior surface for some distance,
and then gradually turning and becoming flattened laterally.

A specimen showing the disc almost entire.

An individual showing the exterior surface ; the central portions entire, with the
impression of the connecting disc, some portions of which remain attached
to the stipes. The extent and outline of the disc are distinctly seen.
The appearance of serratures is due to exfoliation, which shows the impres-
sion of the celluliferous side of the stipe upon the stone.

A specimen exhibiting the half of an individual, with the dise unequally ex-
tended between the rays. The margins are all apparently entire, and this
inequality, to whatever accident due, existed in the living animal.

Exterior view of an individual showing some remaining portions of the disc; the
stipes are all broken off beyond the bifurcations.

Another individual showing the inner side, with the commencement of the cells,
which appear in some places as if in double series ; the substance of the
disc is removed.

Enlargement of the exterior surface of the central portion of the specimen fig. 5.

Enlargement of the inner surface of the specimen fig. 6, giving the appearance
of a double series of cells separated by a depressed line in the substance of
the stipe. Sometimes this separation appears to be actual, while else-
where the apparent division is due to the depression along the centre.

Enlargement of a fragment of a stipe, showing the form and proportions of
the cellules.

Puate XI.

The central part of an individual without disc, showing five stipes on one side
and four on the other. This is supposed to be an abnormal form of G.
Logani.

Formation and Locality.— Quebec group; Point Lévis.

GRAPTOLITES. 103

GRAPTOLITHUS FLEXILIS, Hall.
Plate X, figures 3-9.

(G. rurxinis, Hall: Geological Survey of Canada, Report for 1857, page 119.)

Description.—Frond multibrachiate, composed of numerous slender
branching stipes, which are bilaterally disposed on the two sides of their
origin. Radicle minute: funicle short, being little more than one tenth of
an inch in length, dividing at the two extremities, the parts diverging at an
angle of about 105°; each one of these again divides within the space of
a tenth of an inch, making eight principal stipes, which are again several
times bifurcated. Cellules commencing above the third bifurcation, perhaps
above the second. Stipes slender flexuous, the branches diverging at a lesser
angle at each successive bifurcation: stipes and branches filiform at base,
and measuring in their full width, where the cellules are distinct, from
four to seven hundredths of an inch, (a very small proportion of the width
being occupied by the common body) ; curving from the base, and slightly
arcuate in their entire length. ‘The cellules are usually on the inner side
of the curve. In the entire length from the first division of the funicle,
four bifurcations may be counted, and these branches again divide. The
subdivisions give about sixty-four branchlets in the entire frond, subject to
some variation from the inconstancy of the subdivisions.

Cellules short straight narrow, inclined to the axis at an angle of about
30°; nearly one half the length of each cellule being free: length of
cellules equal to about four times their diameter; the denticles acute, or
acutely rounded, varyimg in the same stipe from about twenty-six to
twenty-eight in the space of an inch ; apertures making an angle with the
axis of about 90° ; cell-partitions obscurely marked, and traceable nearly
to the back of the stipe. At the base of the branches the cellules are less
developed, and sometimes appear as simple undulations of the margin.

This species is very distinctive in its features, both as to mode of growth
and manner of bifurcation, as well as in the form and character of cell-denti-
cles. In the first subdivision of the funicle and stipes, it might be mis-
taken on cursory examination for G. Logani; but the divergence of the
first division is always less, and the second subdivisions always diverge at
a different angle, while the branching of the stipes forms a very distinctive
feature. The specimens examined show no evidence of ever having
possessed a central disc. The substance of the stipe has an appearance of
being more flexible than in any other species, though this character may
be varied with the condition of preservation or the nature of the imbedding
material. Under a lens, the axis and principal branches are rounded, with

_a thin corneous expansion or alation on each side, representing 1 in a figeaee
the central corneous cup or disc of other species.

104 CANADIAN FOSSILS.

In this species, the branches are sometimes compressed vertically (or in
the direction from the celluliferous face to the back of the stipe), to such
a degree as to give an apparent double serrature, or a celluliferous face.
on each side. In this condition, the cell-apertures are at right angles to
the direction of the axis, or sloping a little backwards, with the ex-
tremities somewhat rounded. When the celluliferous side, thus com-
pressed in the direction of the cellules, is uppermost on the surface of
the shale, a lme may sometimes be traced across the branch, joming the
upper edges of the serratures, and being in fact the continuation of the
cell-margins flattened against the stipe, while the extremities project on
either side.

In this way we have a great variety of aspects: the smooth surface of
the branch, with minute striations upon the outer side; the inner side,
when not compressed, having cellules showing as indented lines across the
surface (1); the double serration produced by a greater pressure in the same
direction, or with the back of the stipe uppermost (2) ; again, as the branch
is gradually turned around, these serratures disappear from one side,
and become more prominent upon the other (3), finally showing their full
breadth as the branch is compressed in its transverse or lateral direction.*

My 2 3

eee Gage Se

The specimens examined are in a finely laminated greenish-black shale.

EXPLANATIONS OF FIGURES OF GRAPTOLITHUS FLEXILIS, Hall.
Puate X.

3. A fragment of slate preserving more than half of a frond, and showing the
folding and crossing of some of the branches.

4, A fragment preserving parts of three individuals, the extremities of the branches
all broken off.

5. The central portion of the frond of another individual.

6. Separated branches preserving the cellules in unusual perfection.

7. An enlargement of the centre of the frond, showing the short radicle and the
usual mode of branching. The central part of the axis is rounded, with a
narrow corneous alation at the sides.

8. A bifurcated fragment enlarged: the cellules have been flattened vertically,
causing them to be visible in slight indentations on both sides of the axis.

9. <A portion of a branchlet enlarged, showing one part compressed laterally,
with the cellules fully expanded, while the other, on the right hand, is
gradually twisted so as to show only the back of the branchlet.

Formation and Locality.—Quebec group ; Point Lévis.

* These illustrations of the effects of pressure upon the cellules were given in the
Report of the Geological Survey of Canada for 1857.

GRAPTOLITES. 105

GRAPTOLITHUS RIGIDUS, Hall.

Plate XI, figures 1-5.

(G. rieipus, Hall: Geological Survey of Canada, Report for 1857, page 121.)

Description.—Frond multibrachiate, composed of numerous slender
branching stipes, equally disposed on the two sides of their origin. Radicle
minute : funicle short, being a little more than one tenth of an inch in length,
dividing at the two extremities, the divisions diverging at an angle of 115°;
each stipe again bifurcating at least five times, following the principal axis,
and occasionally six times in mature individuals ; the principal branches
again bifurcate twice or three times before reaching their termination.

In the first bifurcation of the stipe, (or second from the radicle, ) the angle
of divergence is about 78°, and in the second about 60° ; while the succeeding
divisions diverge at a less angle, and become somewhat curved. In one
of the stipes beyond the first division (making one eighth of the entire
frond) we are able to count fifteen bifurcations ; giving eighteen branchlets
to a secondary division of the stipe; or 18 x 8, = 144 in an entire frond,
if uniformly branched as in the one examined.

Stipes and branches slender, cylindroid exteriorly, rigid, nearly uniform
in width to the third bifurcation ; all the measurements from the base giving
about four hundredths of an inch diameter upon the outer side or back of
the branches. A single specimen, which is apparently the upper side of
the stipe, is nearly twice as wide as the above, and preserves a part of the
solid axis: this is replaced by iron pyrites. |

None of the specimens exhibit well-defined cellules below the last bifur-
cation, though some of the branches are obscurely undulating or denticu-
late on one side ; but the specimens examimed do not admit of a satisfac-
tory determination of these characters.

The impossibility of tracing any evidence of cellules upon any part of
the frond below the last bifurcations, suggests the possibility that this
Species was not celluliferous except'at the extremities of the stipes or
branches. In most of the specimens examined, these celluliferous parts
have probably been broken off; since it is evident that the whole frond
has been subjected to maceration, and even the stronger parts are often
broken. The regularity of bifurcation is a remarkable feature, and fur-
nishes a character by which even fragments of the species can be readily
distinguished; smaller fragments may be known by their rigid wiry
appearance.

106 CANADIAN FOSSILS.

EXPLANATIONS OF FIGURES OF GRAPTOLITHUS RIGIDUS, Hall.

PuLatE XI.

1. A fragment preserving the centre and principal branches.

2. <A larger specimen, showing the principal ramifications of the branches. This
and the preceding specimen show only what appears to be the non-cellu-
liferous portion of the frond.

3.

The extreme parts of some branchlets laterally compressed, showing the cellu-
liferous parts of the frond.

4. An enlargement of one of the branchlets of fig. 3.

A strong branch with part of the branchlets, showing the lower side or non-
celluliferous portion of the frond.

Formation and Locality—Quebec group ; Point Lévis.

GRAPTOLITHUS ABNORMIS, Hall.

Plate XI, figure 6.

(G. aBnormis, Hall: Geological Survey of Canada, Report for 1857, page 117.)

Description—Frond consisting of numerous slender bifurcating stipes,
bilaterally arranged. Radicle minute; funicle long, bifurcating on each
side ; distance between the bifurcations one third of an inch; the divisions
diverging at a little less than a right angle, while the inner subdivisions (or
those adjacent to the radicle ), after the second subdivision, diverge at right
angles to the funicle. Stipes branching several times, one division showing
four bifurcations beyond that of the funicle, giving ten branches for the
quarter, or forty for the whole frond : stipes and subdivisions sub-cylindrical,
being rounded on the lower side, grooved in the centre upon the upper side,
and curving at the bifurcations : the width from one to two hundredths
of an inch; free from cellules to the fourth division, counting that of the
funicle as the first division. The stipes and branches maintain nearly the
same dimensions throughout their entire length. Outer divisions appa-
rently celluliferous. Cellules obscure, marked only by undulations upon
the margin of the branches.

This species, in its general aspect, resembles G. Logani and G. flezilis ;
but differs in important particulars. The funicle is more slender, and
nearly twice as long as in either of those species; the divisions of the
funicle makes a lesser angle, and the divisions of the stipe near the base

GRAPTOLITES. 107

are quite different. In the outer subdivisions it approaches in some degree
to G. flexilis, the stipe being always more curved in its divergence at
the bifurcation. The absence of cellules on all of the lower divisions of
the stipe distinguishes this from any other species known to me at the
present time, except G. rigidus; from which it differs in the manner of
bifurcation and in the long slender funicle.

In the specimen before me there is a slight dissimilarity in the mode of
branching on the two sides; but this relates only to details, and the speci-
men is imperfect, showing one of the main divisions, and only a small part
of the other.

EXPLANATION OF FIGURE OF GRAPTOLITHUS ABNORMIS, Hall.
Puate XI.

6. A fragment of slate preserving the centre and the branches on one side to
beyond the first bifurcation. The other side is imperfect, and apparently
less developed.

Formation and Locality. Quebec group ; Point Lévis.

GRAPTOLITHUS RicHARDSONI, Hall. (n. s.)
Plate XII, figures 1-8.

Description.—Frond consisting of strong sub-linear branching stipes, the
number from their origin unknown ; branchlets diverging at an angle of about
15°, and measuring in their transverse diameter about five hundredths of an
inch ; the vertical diameter from ten to fifteen hundredths of an inch. The
test appears thick and somewhat striated ; the cell-partitions often strongly
marked ; the common body occupying less than one fourth the width of
the stipe. Cellules long and narrow, curving upwards, making an angle
with the axis of from 25° to 35°; from four to six times as long as the
width of the aperture, one fourth of the length or less bemg free: the
angle of the aperture with the axis is about 140° ; cell-denticles obtuse or
obtusely poimted, eighteen or nineteen in the space of an inch.

The separated stipes of the species, when not branched, resemble those
of G. octobrachiatus, but the cellules are more inclined, making a less
angle with the axis, while the angle of the aperture is much greater. In
the branching specimens, we have a character which distinguishes it from
any other species.

108 CANADIAN FOSSILS.

The specimens examined have the cellules partially or entirely filled with
iron pyrites, or other mineral matter, giving a nodose appearance upon the
surface ; while the back of the specimens, when vertically compressed, is
likewise nodose. We are not able to associate this form with the others
according to the rule which we have adopted of commencing with the two-
stiped forms, and thence going on successively to the more complex, or
subdivided forms. It is probable however that this one, in its normal
condition, had a form and mode of growth similar to G. flevilis and G.
rigidus, but was of much stronger habit in all its parts.

EXPLANATIONS OF Figures or GRapTouitaus Ricwarpson1, Hall.
Prats XII.

1. A fragment of slate, preserving a stipe, with six branches in its apparent con-
tinuation, and impressions of two others in the intermediate space ; two of
“these again bifurcating.
2. A fragment preserving several branchlets, which are compressed in different
directions, showing the sides and apertures of the cellules.
3. An impression of a bifurcating fragment, the cellules of which were filled with
mineral matter and vertically compressed.
4, <A fragment of a branch laterally compressed.
5. The impression of a bifurcating branch where the cellules are somewhat obliquely
compressed, and partially filled with mineral matter.
6. A fragment enlarged, giving a lateral view of the cellules.
7. An enlargement from an impression of a branchlet which was obliquely com-
pressed, having the cellules filled with mineral matter.
8. Enlargement of a fragment where the cellules are filled with mineral matter and
vertically compressed.

Formation and Locality—In the shales of the Quebec group; three
miles above the river Ste. Anne.

GRAPTOLITHUS RAMULUS, Hall. (a. s.)
Plate XII, figures 9, 10.

Description.—The specimen described consists of a small branch show-
ing two bifurcations: the substance is extremely thin and much compressed
in soft finely laminated shale.

Stipe and branches slender, test thin, greatest width about four hun-
dredths of an inch ; width of branches half as great. The common body
occupies nearly one half the entire width of the stipe: branches diverging
at an angle of 40° to 50°.

GRAPTOLITES. 109

Cellules short and comparatively broad, inclined at an angle of about
25°, free for more than one half their length; the length of cellules about
two and a half times that of the aperture : margin of the aperture making
an angle of about 140° with the axis: denticles or cell-extremities short
and obtuse ; about twenty-eight in the space of an inch.

This species, in its mode of branching, form, and proportion of cell-
denticles, differs from any other examined. It has a slight resemblance to

G. flexilis.
EXPLANATIONS OF Figures OF DENDROGRAPTUS RAMULUS, Hall.

Puiate XII.

9. <A small bifurcating branch.
10. An enlargement of fig. 9, showing the form and extent of the cellules.

Formation and Locality.—Quebec Group ; Pomt Lévis, below the
village, in a loose mass of shale.

Genus DIPLOGRAPTUS, McCoy.
Diprion, Barrande ; Petalolithus, Suess.

Characters—Frond simple (or compound ?). Stipes simple, flattened
or quadrangular; sides parallel or sub-parallel. Cellules arranged in a
single series on the two sides of a double central axis: cellules oblique
to the axis, the cell-apertures opening towards the apex; cell-denticles
prominent, often mucronate.

These forms are known only as simple stipes, which are supposed to
have grown from a fixed root. From analogy with those which I have
designated Ketiograptus, I conceive they may have grown also in a com-
pound form, proceeding from a central axis.

The genera Retiolites, Retiograptus, and Phyllograptus are, in some
of these characters, similar to Diplograptus ; and some of the latter
have been included under this designation. The mode of imcrease and
arrangement of the cellules in those genera presents important differences ;
and I would propose to restrict the term Diplograptus to such forms as
are included ia the above description, or those where the arrangement and
growth of cellules are similar to those of G. pristis, G. palmeus, and
G. pristiniformas.

The paucity of species and of individuals of this type is a remarkable
feature in the collections from the Quebec group. It has scarcely been
- possible to find specimens for a proper illustration of the spec es.

110 CANADIAN FOSSILS.

DIPLOGRAPTUS PRISTINIFORMIS,* Hall.

Plate XIII, figures 15-17.

(GRAPTOLITHUS PRISTINIFoRMIS, Hall: Geological Survey of Canada, Report for 1857,

page 133; Geology of Canada, 1863, page 955. FucompEs DENTATUS: Brongniart,
Histoire des Végétaux Fossiles, vol. 1, p. 70, 1828.

Description.—Stipe flattened simple sub-linear, celluliferous on the two
sides, narrower at the base, obtuse, showing an extended slender radicle,
gradually expanding above and obtaining its full width (about eight
hundredths of an inch) within half an inch from the base. Cellules
narrow, Closely arranged; the free extremity sometimes acute, some-
times obtusely rounded ; inclined to the axis at an angle of less than
20° ; from six to eight times as long as wide, a little more than one third of
their length free: angle of the aperture with the axis very variable, de-
pending on the direction of the compression. About twenty-eight cellules
in the space of an inch. Axis strong, often extending considerably beyond
the celluliferous portion of the stipe, and sometimes marked by a groove
indicating a line of separation.

This species bears some general resemblance to G. pristis (Pal. N. Y.,
vol. i, p. 265, pl. 72, fig. 1); but the stipe is narrower, and the cellules
narrower and more closely arranged. In general form it resembles G.
“angustifolius ; but in that species the margin is more deeply indented, the
cell-denticles are always rounded, and the cellules inclined at a higher
angle to the axis.

EXPLANATIONS OF Figures oF DiPLOGRAPTUS PRISTINIFORMIS, Hall.
Puate XIII.

15. A fragment of a stipe, showing the usual form and proportions of the best-
preserved specimens.

16. A smaller individual, with the mid-rib or axis extending beyond the body of
the stipe.

17, An enlargement from fig. 16, showing more distinctly the form of the cellules.

Formation and Locality.—Quebec group ; Point Lévis.

* This species is probably identical with Fucoides dentatus, Brongniart, ut cit. See
note under G, bryonoides, page 84,

GRAPTOLITES. 111

DIPLOGRAPTUS INUTILIS, Hall. (n. 8.)
Plate XIII, fig. 14.

Description.—Stipes, small and obscure, cellules angular, the free por-
tions extending almost rectangularly to the axis, and produced into sub-
mucronate points. The cell-divisions cannot be traced beyond the serra-
tures. The solid axis is slender, and extended beyond the celluliferous
portion of the stipe.

These specimens occur as short stipes which preserve an extension of
the solid axis, sometimes as great as the celluliferous portion. The
distinguishing features are the angular extensions of the cellules, which
are nearly equilateral, and sometimes slightly mucronate at their ex-
tremities.

This species occurs with Climacograptus antennarius and Retrograptus
ensiformis, and has been observed in only a few specimens.

Formation and Locality.—Quebec group ; Point Lévis.

Genus CLIMACOGRAPTUS, Hall. (n. g.)

Simple stipes with sub-parallel margins, having a range of cellules on
each side; axis filiform; cellules short and square ; apertures apparently
excavated in the margin of the stipe, and transversely oval or sub-
quadrate ; cell-denticles or appendages, if present, usually on the upper
side of the aperture.

Several species of this type at present known are simple stipes with
nearly parallel sides, marked by transversely-oval or quadrangular cell-
apertures, which, when compressed against the body of the stipe, give the
appearance of those forms described by Linnzeus and subsequent authors
as Graptolithus scalaris. In one species, where the stipe apparently
preserves its natural proportions, the shorter diameter is about three fifths
the longer diameter, and the axis is slender and filiform. In several
of the species the axis is seen extending below the base of the
cellules; while there is often a more or less extended oblique process
from each side at the base, as shown in C. antennarius and C. bicornis.
(Pl. xxii, figs. 11,13; and pl. A, figs. 13, 15, 16, and 17.)

These species are separated from such forms as G. pristzs on account
of the difference in form of cellules, or rather of cell-apertures, since the
limit between the cellule and the body of the stipe is not easily observed in

112 CANADIAN FOSSILS.

flattened specimens. The species Graptolithus (Climacograptus) bicornis
may be considered as the type of the genus; and I conceive that most of
those described as G. sealaris are veritable species of this genus; among
these I would cite pl. i, figs. 5 and 6, and pl. i, figs. 14, 15, and also
figs. 7 and 8, Barrande, Graptolites de Bohéme. In the latter figure
the axis lies obliquely across the cell-apertures, a feature similar to that
shown in plate A, fig. 14, of this memoir. Graptolithus teretiusculus,
Hisinger, G. rectangularis, McCoy, and many of the figures on tab. i
and tab. i of Geinitz’s Graptolithen, belong to this type.

In suggesting a generic name, I have recognized the original specific
designation of Linneus, G. scalaris.

The form of cellules in the peculiar group of which G. ramosus may be
considered the type, is very similar to G. bécornis, and should be separa-
ted from Graptolithus proper for the same reason, forming a sub-generi¢
group, for which I suggest the name of Dicranograptus.

CLIMACOGRAPTUS ANTENNARIUS, Hall.

Plate XIII, figures 11-13.

(GRAPTOLITHUS ANTENNARIUS, Hall: Geology of Canada, 1863, page 955.)

Description.——Stipes small, simple, quadrangular, flattened, slightly
narrowed towards the base. In their natural condition they have been
slender sub-quadrangular tubes, celluliferous on two sides, and having a
width when flattened, including the denticles, of thirteen hundredths of an
inch. Axis strong, extending beyond the upper extremity of the stipe,
and sometimes marked by a longitudinal groove : base obtusely pointed, and
having the axis slightly extended in the middle with two setiform processes,
one from each side, diverging at an angle of about 60° with the axis,
and slightly curved, the two including an angle of from 120° to 125°.
Cellules short, nearly twice as wide as long; cell-denticles nearly rec-
tangular to the axis, and frequently inclmed; from about twenty-four
to twenty-eight in the space of an inch. Surface smooth, and the test
extremely thin.

Under this species I have included individuals having the same habit
and form, but varying in the distance of the cellules, and presenting much
variety of aspect from the different directions in which the stipe has been
compressed. In some examples, the margins of the stipes present rec-
tangularly-projecting processes or spinules, which vary from being barely

/ GRAPTOLITES. 113

visible to having sometimes a length equal to one third the width of the
stipe. Sometimes the margins of the stipes are entirely smooth and
straight, and the flattened surface shows indentations produced by the
cellules. Often the surfaces are so nearly smooth that these indenta-
tions may be readily overlooked. In those flattened stipes where the
margins are straight, or where only minute points are visible on the margin,
the width varies from nine to eleven hundredths of an inch.

In all well-preserved specimens, whatever the aspect of the cellules, the
basal processes or radicles are nearly constant in presence and direction ;
and the solid axis always projects beyond the upper end of the stipe, and
sometimes to the extent of an inch beyond the celluliferous portion. In
the extension of the cell-denticles upon the margins of the stipe, in the
condition represented in fig. 12, the specimens bear some resemblance to
Letiograptus.

EXPLANATIONS OF FIGURES OF CLIMACOGRAPTUS ANTENNARIUS, Hall.
Puate XIII.

11. A young individual, compressed in such & manner that the cell-apertures are
not shown upon the margin.

12. A flattened stipe, presenting only the mucronate terminations of the cell-
apertures beyond the margin.

13. An older individual, showing the margins of the stipe extending beyond the
cell-apertures, while the cellules are visible in the substance of the stipes
as darker areas.

Formation and Locality — Quebec group ; Point Lévis.

Genus RETIOLITES, Barrande.

Generic characters.—Stipes thin, flat, elongate, triangular, composed of
two series. of cellules symmetrically arranged in regard to the axis of the
figure. The cellules arise from a single internal canal which occupies the
central portion of the stipe. The cell-orifices are disposed upon the sides
of the triangle, making an acute angle with the axis, and leave no space
between themselves.

The above is essentially the description of this genus given by Mr.
Barrande.

The species from the Clinton group, which I have referred to this genus
is extremely flattened, and it is not possible to determine that it has a tri-
angular form. It possesses a very distinct axis and cell-divisions, which
however may sometimes be concealed by the reticulate covering. In the

114 CANADIAN FOSSILS.

Canadian species I have not been able to discover a reticulate structure
similar to the European species, nor like that from the Clinton group of New
York ; but there is sometimes an apparent punctate texture, and the test
is thickened. Although the axis and cell-divisions are usually distinctly
visible, they have not the characters of Diplograptus.

The R. Geinitzianus of Barrande is found in Bohemia and Saxony at the
base of the Upper Silurian, and probably not far from the same horizon as
the American species ft. venosus.

The R. ensiformis of the Quebec group holds a much lower geo-
logical position, which, together with the difference of structure, leads me
to suppose that it may ultimately be separated as a distinct genus.

RETIOLITES ENSIFORMIS, Hall.

Plate XIV, figures 1-5.

(GRAPTOLITHUS ENSIFORMIS, Hall: Geological Survey of Canada, Report for 1850, p. 133.)

Description.—Stipe simple, sub-ensiform or elongate-lanceolate, usually
broader in the middle and narrower towards the extremities: axis central,
with strongly-marked obliquely ascending striz reaching to the margins.
Cellules obscure, apparently corresponding to the striz ; margin usually
well defined. Width of stipe, in the largest individuals, sixteen hundredths
of an inch ; length nearly two and a half inches. Other specimens have a
width of one twentieth of an inch, with a length of half an inch. Cellules
about twenty-eight in the space of an inch, inclined to the axis at an angle
of about 50°, and without any appreciable portion being free. The solid
axis is slightly undulating, and the cell-partitions alternate on the two sides
of it, thus separating the cellules from each other. In some specimens the
base is rounded and obtuse; others show a continuation of the axis, or a
central straight radicle. Substance of the test punctate.

All the specimens are extremely flattened, and it is very difficult to
distinguish any difference in the opposite sides of individuals. In the best-
defined specimen there is a distinct axis with alternate diverging filaments
or cell-divisions, which reach to the outer margin, the substance being nearly
all removed except this skeleton. In a single specimen, the axis is not
strictly defined, and is broader, while the diverging partitions are less
strongly marked. This one affords the only evidence that we have of the
difference in the two sides of the species, a difference shown in the
R. Geinitzianus of Barrande.

GRAPTOLITES. 115

In the punctate test and undulating axis, we have the characteristics of
Retiolites, which, as illustrated by Geinitz, shows on one side the cell-
partitions reaching to the well-defined axis. The same feature of Hetio-
lites is shown im a still stronger degree in the figures of Edward
Suess.*

EXPLANATIONS OF Figures OF RETIOLITES ENSIFORMIS, Hall.
Puate XIV.

1, 2, 3. Individuals showing gradations in growth, and slight differences in their

proportions.
4, A nearly entire stipe of the largest size observed.
5. An enlargement from the specimen fig. 4.

Formation and Locality Quebec group ; near Point Lévis.

Genus RETIOGRAPTUS,} Hall.

Generic characters.—Frond simple ? or compound, consisting of numer-
ous simple stipes in bilateral arrangement, proceeding from an axis or
radicle, (or of single stipes growing from their own radicles ?) Stipes elon-
gate-oval, or lanceolate, with longitudinal axis and reticulate structure;
margins ornamented with mucronate points. The axis often extends beyond
the substance of the stipe in a mucronate tip, and in one species there are
long setze extending from what appears to be the base of the stipes.

I had originally referred the Retcograptus tentaculatus to the genus
Retiolites of Barrande (describing it under the genus Graptolithus). A
farther examination of its structure, together with that of a species from
the shales of Norman’s Kill near Albany, induced me to separate them from
Retiolites, and propose the name of etiograptus. Subsequently an exam-
ination of some specimens from the Utica formation from Lake St. John in
Canada, revealed a minute compound form which is illustrated in fig. 9 of
pl. xiv. Although presenting some slight differences from the other two
known species, I conceive it not to be generically separable from them.
The specimen is extremely interesting for its illustration of a mode of growth

*Ueber Boémischen Graptolithen, von Edward Suess. Naturwissenschaftliche Abe
handlungen, IV Band, IV Abth. Tab. VII, 1851.

} A species of this genus has been describe din the third volume of the Palzon-
tology of New-York, Supplement, p. 518; and in the Thirteenth Report on the State
Cabinet of Natural History ; but no generic description was given.

116 CANADIAN FOSSILS.

not before known in forms of this kind, and suggests the possibility, if not
the probability, that some others of the bi-celluliferous or diprionidian forms
may have grown with this compound arrangement of the parts.

The stipes of the specimen figure 9, if separated, present an aspect very
analogous to those of Diplograptus and Retiolites, and would not be sup-
posed to have had any different mode of growth. ‘The setiform processes
at the base of some of the species may be regarded as an objection to the ©
compound mode of growth; but this feature would offer a still greater
objection to regarding those stipes as simple, and as having grown from an
independent radix. The three species of the genus now known to me,
present some important points of difference one from the other, and there
still remains some obscurity regarding the arrangement of the cellules.

These forms are nearly related to the Retiolites of Barrande ; but the
-texture of the specimens examined, and the arrangement of the parts,
differ so much from authentic specimens of A. Geinitzianus, that I have
separated them under the above designation.

RETIOGRAPTUS TENTACULATUS, Hall.
Plate XIV, figures 6-8.

(GRAPTOLITHUS TENTACULATUS : (Genus Retiolites, Barrande) Geological Survey of Canada,
Report for 1857, p. 134.)

Description.—Original form of the entire frond unknown. Stipes simple,
narrow, very elongate-elliptical when entire, narrower at the base, and
gradually expanding above to the middle of their length; where they attam
the greatest width, and become gradually narrower above, with the apex
obtuse or rounded.

Central axis strong and well defined, extending beyond the stipe a dis-
tance equal to half its length: base furnished with two elongate diverging
sete, which extending from the outer edges, gradually curve down-
wards, and finally assume a direction nearly parallel to the axis. Within
these long outer processes, and proceeding from the centre of the base of
the stipe, there is an extension of the filiform axis, which sometimes appears
in its duplicate character.

Exterior margins reticulate, furnished with a row of hexagonal meshes,
separated by slender processes extending from the substance of the stipe,
which unite in a continuous filiform border; from this proceed, at about
every second reticulation, short setiform spines, which in the middle of
the length of the stipe are rectangular to the axis, while nearer to the base

GRAPTOLITES. ING

and to the apex they are inclined towards the axis in opposite directions.
These spines are sometimes on the outer margin of each mesh, and some-
times visible only on every third one. With these rows of meshes, when
preserved, the stipe has the appearance of a flattened corneous film with a
central axis, which is divided into cellules as in other forms of Graptolitide ;
and when the outer meshes are broken off, these cell-divisions project as
mucronate points beyond the margin of the stipe. These marginal meshes
correspond to the divisions of the stipe marked by the cell-partitions, and
might be regarded as showing the limits of the cell-apertures, which have
opened obliquely tc the transverse direction of the stipe. These meshes
or cellules are arranged in the proportion of about twenty-eight im the space
of an inch, the stipes bemg usually nearly three fourths of an mch (the
longest one eighty-three hundredths) in length.

We have no evidence that the test is punctate, and it has all the ap-
pearance of the ordmary graptolites. The greatest width observed in any
stipe, exclusive of the marginal meshes, is seventeen hundredths of an inch.
In one specimen the extreme length of the stipe, exclusive of the radicles
and extended axis, is seventy hundredths of an inch; and the width,
exclusive of the meshes, is fifteen hundredths, and including the meshes,
twenty hundredths of an inch.

The specimens examined are all extremely compressed, so that it is im-
possible to determine any points of structure beyond those presented upon
the surface. Ido not suppose that the original form has been that of a
flattened stipe, but rather of a quadrangular or fusiform sac, perhaps even
convex on one side and flat or concave on the other. The cell-divisions
are traceable almost to the central axis ; and itis the continuations of these
that form the reticulation of the margin, and are again produced in seti-
form spines. It is impossible to reconcile a structure like this with any
thing previously described among the Giraptolitide ; and though our views
of their structure may be somewhat modified by an examination of better
preserved specimens, they cannot be united with the ordmary forms;
so that while Jetioltes is separated from Graptolithus proper, we may
regard this form as equally entitled to generic designation.

EXPLANATIONS OF FigurES OF RETIOGRAPTUS TENTACULATUS, Hall.

PLaTE XIV.
6. Anindividual of the natural size, with the marginal reticulations nearly entire. —
7. The preceding specimen enlarged.

8. An enlargement of another individual, where the marginal reticulations are
but partially preserved.

9. An illustration of a compound form of Retiograpius (R. eucharis), from the

Utica formation of Lake St. John. (For a description of this species, see
Appendix.)

Formation and Locality— Quebec group ; Point Lévis.
H

118 CANADIAN FOSSILS.

Genus PHYLLOGRAPTUS, Hall.

Gr. Svarov, folium, and ypadw, scribo.

(Puytiogrartus: Geological Survey of Canada, Report for 1857, page 135.)

Generic characters.—Frond consisting of simple or compound foliiform
stipes, which are celluliferous upon the two opposite sides, the margins
having a mucronate extension from each cellule: or consisting of ‘similar
forms united rectangularly to each other by their longitudinal axes, and
furnished on their outer margins with similar cellules ; the whole supported
on a slender radicle, or combined in groups.

These forms are analogous in structure to Diplograptus ; but instead
of two simple stipes united by their solid axes,'we have in the examples
illustrated, four stipes united in a similar manner, giving four separate and
independant sets of cellules. The cellules have hkewise a proportionally
greater development, giving a broader form to the stipes than in typical
species of Diplograptus. ‘These bodies, which usually appear upon the
stone as simple leaf-like expansions, may have been attached in groups to
some other support ; but the forms of most of them, and the character of
the projecting radicle ‘at the base, give the same indication of the entire-
ness of the frond that we have in ordmary forms of Diplograptus.

Of all the Graptolitide, these forms furnish perhaps the best illustration
of the lesser development of the cells at the base of the axis, and of their
eradual expansion above, as far as the middle or upper part of the stipe.
Many of them diminish from the centre upwards, and rarely the cells are
more developed above the centre, reversing the usual mode, and leaving
the narrower part at the base.

‘When bodies of this form were thrown down upon a muddy sea-bottom,
they would become imbedded mainly in two positions. The most common
position appears tobe that in which the parts retain a vertical and a horizon-
tal direction, as in fig. 1; the lower division or folium d would thus become
first imbedded ; while the folia 6, ¢ would lie in the plane of deposition, and a
would be the last imbedded. ‘The slaty lamine separate along the line J, ¢,
either above or below the folia 6, ¢; leaving on one side the folia and on the
other their impression. If the separation takes place above, then the bases
of the cellules of a remain; these are directed obliquely downwards to-
wards the base of the stipe. If the separation takes place below the folia
b, c, the cellules of folium d are seen directed upwards, or towards the apex
of the stipe. ‘These modes of separation ‘would present appearances like
figs. 4 and 8, pl. xv; fig. 4, pl. xvi; and figs: 5-and 15, pl. xvi.

The other direction of imbedding would be when the specimens were
so deposited that the laminze rested obliquely to the plane ‘of stratifica-

GRAPTOLITES. 119

tion, as in fig. 2. In-this way, from the accumulation of the sediment,
they would become compressed, as in fig. 3, until the parts 4, d,and a,
e would approach each other, or come in contact. Lying thus, with
the slaty laminze separating above or below them, they would present the
aspects of figs. 6 and 9, pl..xv ; and of fig. 8, plate xvi.

2 3

1
; a
d) d
ec
‘ ad e
d

When the parts 6, are removed, the parts d, ¢ remain, showing the
base of the cellules, as in figs. 4 and 5, pl.-xv, and figs. 3 and7, pl. xvi;
while in the examples where the margins only are removed, we have
appearances like fig. 9, pl. xvi.

PHYLLOGRAPTUS TyPuUS, Hall.

Plate XV, figures 1-12.
(PHYLLogRApTus TyPUS: Geological Survey of Canada, Report for 1857, page 137.)

Description.—Stipes robust, composed of four semi-elliptical parts joined
by their straight sides. As preserved upon the shale, these bodies are
elongate-ovate or lanceolate, broad oval or obovate : cellules about twenty-
four, rarely twenty-two, and sometimes twenty-six in the space ofan inch,
usually obscure at the margin ;.axis. or mid-rib broad, often-crenulate or
serrate ; radicle usually short; im some specimens about half an inch in
length being preserved.

The stipe origimates from.a slender-pointed. radicle. The cellules near
the base are short, coming out almost rectangularly to the axis, or slightly
ascending and gradually increasmg in width, curving backwards or down-
wards, and having the aperture sometimes nearly at right angles to the
axis : the curvature lessens towards the middle of the stipe, and the line of
aperture is parallel to the axis ; while above this they are inclined towards
the axis, and near the summit they are again nearly at right angles to the
axis, but opening in a direction opposite,.to. those, near the base. « Cell-

120 CANADIAN FOSSILS.

apertures mucronate by the continuation of the cell-partitions, the mucro-
nate appendages sometimes appearing to be double, as if each angle of
the aperture had been thus ornamented.* Central axis linear, from half a
line to nearly a line in width. In some examples there is an apparently
greater width, which is probably due to a slipping of the test. This
central axis is often crenulate from the bases or impressions of cellules of
the other division, which is rectangular to that part of the frond pre-
served.

This species assumes a variety of forms, and, from an examination of
specimens of the extremes, they might be regarded as distinct species.
After examining several hundred specimens however, I am not able to
find constant characters to establish specific differences. The individuals
figured represent the principal varieties. I have not thus far observed
forms intermediate between the short broad and the elongate-oval ones,
but they may be found im larger collections. The number of cellules in
entire fronds varies in different individuals from twenty-five to fifty on
each side, according to the size and form of the specimen.

The specimens are all compressed, and the rectangular arrangement of
the parts of the frond, as seen in P. dlicifolius, cannot be seen in these;
the evidence of this character being the serratures along the central axis,
which are transverse to those of the two sides. The proportions of length
and breadth vary extremely ; one of the broad forms has a width of five
tenths of an inch, with a length of eight tenths of an inch, while a long form
is two and an eighth inches in length and six tenths of an inch wide m
the widest part.

In a single fragment of the shale containing this species, the number of
individual stipes within a small space is so great as to suggest the proba-
bility that these have originated from a common axis, as in Ltetiograptus,
and have been separated but a little distance from their centre of attach-
ment. With one exception, all these are of small size, and present no greater
variation than is observed in the stipes of a single frond of etograptus,
fig. 9, plate xiv.

EXPLANATIONS OF FIGURES OF PHYLLOGRAPTUS TyPUS, Hall.
Puate XV.

1. An extremely short and broad form of this species, with the axis broad, and
showing some remains of the cellules at the base of the separated division.

2. An elongate-ovate form of stipe, with a broad axis, which does not show
remains of cellules. Some of the cellules in the upper part of the stipe are
filled with iron pyrites.

> _________

* This feature may possibly be sometimes due to the overlapping of two adjacent
folia, so as to bring the cell-partitions and cell-denticles near to and parallel with
each other, showing a denticle from each one.

GRAPTOLITES. 135)

3. A form similar to the preceding, showing remains of cellules on the upper
part of the axis.

4, An elliptical form of stipe, where two of the divisions have been separated,
leaving the bases of two sets of cellules.

5. <A broadly-elliptical form, from which two of the divisions and the axis have
been removed ; showing the bases of the cellules of the folia remaining in
the slate.

6. A stipe compressed in the same direction as fig. 3 of the generic illustrations,
page 119 ; with a part of one of the folia removed, but not reaching to the
axis. Thelines of the cell-partitions appear as if continued across the
axis.

7. An elongate-lanceolate form of stipe, which does not show cellules in the
line of the axis.

8. An elongate-elliptical and very symmetrical specimen, showing the marks of
cellules along the axis, which is unusually narrow.

9. <A part of a stipe folded in the manner of fig. 6, the upper portion of one side
preserving only the impression of the substance. In the lower part, the
cell-markings on the axis should be shown more distinctly.

10. A group of small stipes upon the surface of a piece of shale. These are given
in their natural size and in their actual relations to each other.

11. An enlargement of a part of an impression of a stipe which has been flattened
in the direction of figs. 6 and 9. A portion of the substance remains, as
shown on the left hand; the cellules filled with iron pyrites.

12, An enlarged portion from'a stipe, showing the double cell-denticles and
corresponding cell-partitions. The narrow spaces on the surface of the
figure are more elevated than the wider ones, with a greater thickness
of the substance; which I suppose may have been caused by the cell-
partitions, which are obliquely compressed, thus showing the cell-denticles.
These elevated spaces become gradually narrower towards the axis, in
accordance with the form of the cells, as shown in the theoretical figure 10,
plate xvi.

Formation and Locality.—Quebec group; Point Lévis.

PHYLLOGRAPTUS ILICIFOLIUS, Hall.

Plate XVI, figures 1-10.
(PH. ILICIFOLIUS : Geological Survey of Canada, Report for 1857, page 139.)

Description.—Frond broadly oval or ovate: axis broad; radicle short ;
cellules from twenty-eight to thirty-two in the space of an inch, varying
slightly with the proportionate length of the frond.

The radicle is rarely visible in the specimens examined. The cellules
from the base are at first slightly ascending, and gradually curve outwards
and downwards, so that the line of aperture is nearly rectangular to the

122 CANADIAN: FOSSILS.

axis. This curvature becomes less in the higher! cellules'; those of the
middle open nearly parallel to the axis, and finally at the summit open
in a direction opposite to those of the base. Cell-apertures mucronate,
by the extension of the cell-partitions beyond the opening, in nearly their
full width ; but seen upon the edge, they appear as setiform processes. The
test is striated parallel to the cell-apertures, which have a concave outline.

As the specimens lie upon the surface of the shale, the central portion,
for about half a line in width, is usually rough, and the broken cellules
are clearly distinguishable ; while on each side are the semi-oval divisions
of the frond, with the cellules spreading from the central axis.

The entire frond in reality consists of four semi-oval or semi-ovate
folia, which are jomed rectangularly by their longitudinal axes, and in a
transverse section present a regular cruciform figure. The expansions
of the two sides, when laterally compressed, show distinct cellules with
projecting mucronate extensions: those which are vertically compressed
have the outer portions broken off in the separated lamine of slate,
and present the bases of the cells; which have been sometimes filled with
mineral matter, and distended before being imbedded. In a few instances
the cells of the lateral portions are filled in the same manner, appearing
as curving conical tubes with the broader extremities outwards.

When the bases of the cellules of the upper or nearest of the folia
remain, they are seen'to be directed obliquely downwards to the axis; but —
sometimes in the process of separation these bases are removed wholly or
in part, and the bases of the opposite folium are seen below the plane of
the two lateral folia, or their impressions, which are spread out on the sur-
face of the slaty lamina: these cellules are then clearly observed to be
directed upwards, as we see them from below.

It not unfrequently happens that this broad celluliferous axis is reduced
to an undulating line, which results from compression in a direction oblique
to the rectangularly-arranged folia, as in fig. 2, page 119, so that the two
adjacent parts are spread out, and consequently no central line of cellules
would be seen. When these have been divided longitudinally a little
on one side of the centre, two sets of cellules are often seen penetrating
the stone in oblique directions to the lamine of shale.

The condition of preservation in several specimens examined is such as
to render unavoidable the conclusion which I have given above, as to their
mode of growth, however anomalous it may seem.

This species differs from P. typus in its thicker substance, propor-
tionally shorter and broader form, and more closely-arranged cellules.

GRAPTOLITES: #23

EXpPLANATIONS-OF Figures oF PHYLLoGRapPTUS ILIcIFoLIUs, Hall.
Pratt XVI.

1. An individual of the natural size, where the folia 6, a* are broken entirely
away beyond the axis, leaving the bases of the cellules of two adjacent
folia visible except at the upper part of the figure, where two or three of
the bases of the other cellules remain.

2. A similar specimen, showing the bases of a set of cellules on each side of the
centre, with two or three of those belonging to the broken folium at the
base of the figure.

3. An enlargement of fig. 2, showing more distinctly the cellules on each side
of the central line, and the small remaining portion at the base.

4. A specimen of the natural size, where one folium is broken away not quite
so far as the axis, leaving the bases of its cellules visible.

5. An enlarged figure from a specimen which has been imbedded transversely.
Three of the divisions have been broken away, leaving impressions of the
lateral ones only, and of the cell-bases, and cell-partitions of the fourth
division, which are directed obliquely upwards from the axis and point of
view. The lower part of the specimen preserves a portion of the lateral
folia, with the bases of the cells of the outer division a*, which are directed
towards the axis.

6. An enlargement of a specimen which is imbedded obliquely, or in a direc-
tion as if the theoretical figure 10 were vertically compressed, leaving
no visible axis. In the lower half of the specimen, the fossil has been
separated in the opposite slaty lamina, leaving only the impression of the
opposite side, which also shows no axis. Inthe upper half of the specimen,
the cellules are well preserved, and on the left-hand side the apertures are
conspicuous. Enlarged to three diameters.

It will be observed that the impression is not quite in the same direction
as the outline in theupper portion of the figure, owing to the obliquely-
compressed folia.

7. A specimen compressed in the same manner.as fig..6; the upper folia have
however been separated, except the bases. of a few of the cellules in the
upper part of the figure, leaving the other two folia imbedded in the shale,
and showing the bases of their cellules ascending from the axis. Enlarged
to three diameters, as in fig. 6.

$. Anenlarged figure of a specimen compressed in the direction first described,
without any separation of the. parts; from which cause there is no proper
axis visible. In this condition, thespecimensresemble Graptolithus folium
of Hisinger, or G. ovatus of Barrande.

9. An enlargement of a specimen. compressed as in fig. 8, but with the cellules
filled, and the margins of the upper two folia broken, showing the cell-
Openings. (8 and 9 are enlarged to twice their natural size.)

10. A restoration of the form of P. ilicifolius, showing the four divisions; which
are represented as cut through transversely, exhibiting the cell-cavities.

Formation and Locality.—Quebec group ; Point Lévis.

* These letters refer to the illustrative figures on page 119.

124 CANADIAN FOSSILS.

PuyLiocraptus Anna, Hall. (a. s.)
Plate XVI, figures 11-16.

Description.—Consisting of flattened elliptical stipes, which are some-
times broader above. Radicle mmute: margins celluliferous, the cell-aper-
tures furnished with long mucronate extensions. Cellules rising from the
axis, expanding in width, and curving outwards and downwards; the curvature
diminishing in the middle, while the upper ones are but slightly curved :
margins of the apertures regularly concave between the extensions of the cell-
partitions, distinctly striated upon the sides parallel to the margins. Axis
celluliferous, its width five hundredths of an inch in a specimen of forty-
three hundredths of an inch in length, the entire width of the specimen
being twenty hundredths of an inch: cellules in the proportion of from
thirty-six to thirty-eight in the space of an inch.

This species is shorter in proportion to its length than either of the
others ; the individuals rarely or never reach the length of half an inch,
and vary from one eighth to seven sixteenths of aninch. The test appears
to be thicker, and the cellules more distinctly marked than in P. angustt-
folius ; while its smaller size and more closely-arranged cellules distin-
guish it from the other species.

EXPLANATIONS OF Figures oF Puyitiocraptus Anna, Hall.

Puate XVI.

11. A specimen with the folia obliquely compressed.

12, 13,14. Individuals showing some varieties of form.. The specimens have all
been so imbedded that one of the folia has been torn away in the separated
lamine of shale, leaving an axis marked by the bases of its cellules.

15. An enlargement of a specimen which has one of the laminew vertically im-
bedded, and shows the bases of the cells as they recede from the axis. The
markings at the sides are from the impressions of the folia, except a small
fragment of one remaining on the left-hand side of the figure.

16. An enlargement from a specimen where the two lateral folia remain, showing
the bases of the cells of the folium which has been broken off, in the
separated laminz of slate. The surface is distinctly striated.

Formation and Locality—Quebee group ; three miles above the river
Ste. Anne.

GRAPTOLITES. 125

PHYLLOGRAPTUS ANGUSTIFOLIUS, Hall.

Plate XVI, figures 17-21.
(Pu. anaustirorivs, Hall: Geological Survey of Canada, Report for 1857, page 139.)

Description.—The stipes, as seen on the slaty lamine, are elongato-ellip-
tical or elongato-lanceolate, being usually a little broader near the base.
Radicle scarcely visible: margins celluliferous ; cellules about twenty-four
in the space of an inch (rarely twenty-six, while one short broad form
shows twenty-eight) ; cell-apertures with an elongate triangular denticle,
which is mucronate at the extremity: the denticle is once and a half as
long as the width of the cell. Central axis from three to four hundredths

‘of an inch in width, obscurely indented by the cellules of the other divisions
of the frond.

This species differs from either of the preceding in its narrow and elon-
gate form. The specimens are numerous, but being for the most part on
slaty laminze which are extremely compressed, they preserve scarcely any
substance ; a mere outline, with a more brilliant surface than the rest of
the rock, being almost the only remaining characterby which they are
recognized. In a few individuals the test is better preserved, showing a
moderate thickness. The cell-margins on the upper side are less extended
on the cell-partitions than in the preceding species ; while on the lower side
they are equally or more extended, giving a form of aperture different
from that of the other species, and a different denticle.

EXPLANATIONS OF Figures oF PHYLLOGRAPTUS AUGUSTIFOLIUS, Hall.
PiatTe XVI.

17.. A small and comparatively wide specimen, with a distinct linear axis, but
without evidence of cellules.

18. A more elongate specimen, with distinct axis, with a darker line in the centre.

19, 20, 21. Varieties of form and proportion. The specimen fig. 21 is the largest
observed. .

This species is placed under Phyllograptus from its similarity in form to
others of the genus, although evidenee of the quadruple division has not
been established. The want of parallelism of the margins, and the sub-
elliptical form would, I conceive, be sufficient to remove it from the genus
Diplograptus.

Formation and Locality— Quebec group; Point Lévis.

126 CANADIAN: FOSSILS.

Genus. DENDROGRAPTUS,, Hall.

Gr. Sevdpov, arbor, and ypadpw, scribo.

Cole) to)
footstalk, which is sometimes furnished below with a distinct root: or. root-

like bulb, and above is variously ramified, and subdivided into numerous
branches and branchlets, which are but slightly divergent ; the whole pro-
ducing a broad spreading shrub-like frond : (fronds sometimes flabellate ?).
Branches celluliferous on one side: cellules appearing sometimes as simple
indentations on the surface, and sometimes distinctly angular, with the
denticles conspicuous, In some specimens the cellules are indicated by
prominent pustule-like elevations, arranged along the centre, or in sub-
alternate order on one face of the branch. Substance of the stipe and
branches corneous, solid or tubular: surface striated.

These bodies present specific distinctions in the strength of the stipe or
stem, in the mode of bifurcation and number of branches, in the character
of the surface, and in the general form of the frond. ‘The celluliferous
side usually adheres to the stone, and we perceive only some simple undu-
lations or unequal thickening of the back of the branches. Often the
branches have an alation on one side, like a thin pellicle flattened and
extended along the more solid axis. ‘The radix or radicle consists of an
expansion of the footstalk, and in one species appears like a flattened bulb
or disc, of irregular form. ‘The footstalks, when well preserved, are
marked by interrupted longitudinal striz, and the non-celluliferous faces of
the branches are variously striated, the striz in most instances being
unequal or interrupted in their course.

In the study of the fossils of this general character, I have indicated
the species from the Potsdam sandstone of the Mississippi valley as the
typical form of the genus. In this one, the cell-denticles are quite con-
spicuous and distinctly angular ; while in some of the species from the
Quebec group, the form of the cell-denticles is obscure, and in others it is
shown. only as a round or elliptical pit or pustule, depending on the con-
dition of preservation. hese differences. in the form of the cellule lead
me to suppose that a farther subdivision of this group may become neces-
sary ;, but im the condition of the specimens in the collection before me, I
do not feel justified in attempting to do this at the present time.

There is likewise a gradation in the mode of growth among the species,
by which there is an apparent transition from the form of Dendrograptus
proper, to those similar to Dictyonema. I have thought it necessary to
separate two forms of the latter type under another designation.

The following figures, already published in the Geological Report of
Wisconsin, illustrate the character of the species of ‘this genus from the
Potsdam sandstone.

Generie characters.—-Fronds simple or aggregate, consisting of a strong

GRAPTOLITES: - Led

Denprocraptus Haniianvs, Prout.

a. A portion of the frond, of the natural size.

b. An enlargement of one of the branchlets, showing the cellules.

c. The main stipe and some of the principal branchlets, natural size. There is an
expansion or protuberance at the base or radicle, one side of which is broken off.

DENDROGRAPTUS. FLEXUOSUS, Hall. (a. s.)
Plate XVII, figures 1, 2.

Description.—Frond broadly expanding. Stipe short, flexuous, branch-
ing near the base: branches somewhat regularly bifurcating, the divisions
sub-equal in strength and equally diverging. Stipe and branches flatten-
ed, (round in their original form,) very gradually diminishing towards their
extremities, flexuous, the margins of the lower ones scarcely undulating ;
the upper ones more distinctly undulating, and sometimes showing the cell-
denticles when viewed upon the non-celluliferous side. Cellules long,
narrow, extremities free: cell-denticles angular, about thirty-three in the
space of an inch.

This species is less robust than D. fruticosus, the stipe more flexu-
ous, the branches proportionally broader, their divergence more equal and
at a greater angle, giving a wider expansion to the frond. ‘The branches

128 CANADIAN FOSSILS.

are not so distinctly undulated by the projection of the cells, and whenever
these are visible, the form of the aperture or cell-denticle is a distinguish-
ing feature.

In a specimen of coarse greenish or olive shale, which contains this
species, we find also a few fragments of graptolites, among which we
recognize G. bryonoides ; and in another specimen of coarse brown shale,
we find it associated with Phyllograptus typus and Dendrograptus
Sruticosus.

EXPLANATIONS OF Figures or DENDROGRAPTUS FLEXUOSUS, Hall.

Puate XVII.

1. A small frond of the natural size.
2. A part ofa larger frond.

The characters of the cellules and denticles referred to in the deserip-
tion, are derived from some branchlets of the specimen figure 2, which show
these features in a very satisfactory manner. ‘The illustration was unin-
tentionally omitted from the plate, and is given in the accompanying figure.

3. An enlargement of some of the branchlets of Dendrograptus flexuosus,

Formation and Locality—Quebec group; Point Lévis.

GRAPTOLITES. 129

DENDROGRAPTUS DIVERGENS, Hall. (u.s.)
Plate XVII, figures 3, 4.

Description—A fragment of a frond of this species shows a flexuous
stipe of moderate strength, with slender bifurcating branches, the divisions
numerous and widely diverging: cellules arranged in alternating order on
the opposite margins of one face of the stipe ; non-celluliferous face very
obscurely striated.

This species differs from all the others in its regular bifurcation, and in
the wide divergence of the branches. The specimen.is extremely com-
pressed, and the cellules are only determined by indentations in the shale.
Tt occurs in the same shales with D. erectus, Graptolithus Logani, G.
quadribrachiatus, G. denticulatus, G. arcuatus, G. Bigsbyt, and others.

EXPLANATION OF FiguRES oF DENDROGRAPTUS DIVERGENS, Hall.
Puate XVII.

3,4. A specimen of natural size, and an enlargement of the same.

Formation and Locality.—Quebec group; Point Lévis.

DENDROGRAPTUS STRIATUS, Hall. (un. s.)

Plate XVII, figures 5-6.

Description.—Frond numerously branched, spreading. Stipe below the
branches unknown. Branches cylindrical, tubular, substance thick and
strong: branches and branchlets moderately diverging ; non-celluliferous
side finely striated longitudinally ; striz continuous, gently undulating.
Celluliferous face striated : cellules minute, arranged in an alternating series,
or in an undulating line, upon one face of the branches. The indenta-
tions left in the shale give an appearance as of a single linear range of
cellules. Cellules in the proportion of thirty-six to an inch.

This species is readily distinguished by its striated surface. In mode
of branching it resembles D. erectus; but differs in the strize, and in having

cellules on the lower part of the branches. The specimen is in a greenish-
_ olive shale.

130 CANADIAN FOSSILS.

EXPLANATIONS OF Figures or DENDROGRAPTUS STRIATUS, Hall.
Puate XVII.

5. A fragment of a frond, preserving the bases of some of the branches.
6. A portion of the non-celluliferous surface enlarged.

Formation and Locality.—Quebec group ;. Point Léyis.

DENDROGRAPTUS ERECTUS, Hall.: (n. s-)
Plate XVII, figure.7.

Description.—Stipe strong, elongated, erect, nearly straight. Branches
alternate, ascending, and causing at their offset a slight bending or diver-
gence of the stipe: branches bifurcating, branchlets alternating; all very
slightly spreading, the stipe maintaining a greater diameter than the branches
as far as the eighth bifurcation (in the specimen), beyond which it is broken
off. Cellules visible on the branchlets only as slight expansions, causing an
undulation on the margins, and in the impressions causing slight identa-
tions on the surface of the matrix. Surface of the stipe and lower part of
the branches entirely smooth under an ordinary lens.

This species differs from all others of the collection in the elongated and
nearly straight stipe, which maintains its distinction from the branches for
a long distance above the base. It differs from the strong stipes of D.
Fruticosus in the almost regularly alternating branches, which are distantly
and somewhat equally bifurcated. The stipe appears to have been a
strong cylindrical tube of dense corneous texture, and the lower part of
the branches have the same character. ‘The compressed specimen is
marked along the middle of both sides by»a longitudinal groove, which"
appears to have been produced by the flattening of the stipe. The total
absence of strize, and apparently of cellules, on the stipe and lower part of
branches, together with the very slight divergence of the’ branches,
are features peculiar to this species. - It occurs in the same: association as
D.. divergens.

EXPLANATION OF FicurE oF DENDROGRAPTUS ERECTUS, Hall.
Prate XVII.

7. The principal stipe, and bases of some of the branches, of the natural size.

Formation and Locality.— Quebec group ; Point Lévis.

GRAPTOLITES. 131

DENDROGRAPTUS FRUTICOSUS, Hall. (n.s.)
Plate XVII, figures 8, 9.

Description.—Frond robust. Stipe strong, rounded below, and sometimes
terminating in a root-like expansion, flattened above, and irregularly bifur-
cating; the branches frequently subdivided, the bifurcations continuing
almost to the extremities. Branches and branchlets somewhat rounded and
undulating or zigzag in direction, smooth or indistinctly striated on the non-
celluliferous side. Cellules in alternating series on the opposite margins of
the celluliferous side, and distant about twice the width of the branch ;
from about thirty-three to thirty-six in the space of an inch; swelling
out towards the apertures, and giving the undulating appearance to the
branches. Cell-denticles angular or sub-angular, twice as long on the
lower slope as on the upper or aperture side. ‘The cellules make an
angle with the axis of apparently between 25° and 35°.

This species is abundant in the coarse shales which contain Phyllograp-
tus typus. The-general aspect is that of a delicate plant, and it requires
careful observation to detect the celluliferous character of the branches ;
the celluliferous side also more frequently adheres to the stone. In the
impressions thus léft after the removal of the substance of the branch, as
well as upon the branches themselves, we see the cellules arranged on the
margins in alternating series, but with the apertures opening on the same
side.

Whenever the pressure has been upon the non-celluliferous side, and that
side is exposed, the evidence of cellules consists of little more than
enlargements of the sides of the branches. When a stipe is turned alittle
on one side, a row of cellules becomes visible ; and a further turning of the
branch discloses the two series, or the alternating ranges of cellules. The
form of the cell-denticle is much influenced by the direction of the pressure
upon the branches, and also by the character of the surrounding matrix.
The root-hke expansion at the base does not appear to.have been more solid

than the stipe above, and is in appearance not unlike the central discs of
the uniserrate graptolites.

EXPLANATIONS OF Figures or DeNDROGRAPTUS FRUTICOSUS, Hall.
“Pirate XVII.

g. <A frond which is apparently nearly entire. :
9. A more diffuse form of the same species, with some of the branches broken off.-

Formation and Locality. Quebec group; Point Lévis.

132 CANADIAN FOSSILS.

DENDROGRAPTUS ? (CALLOGRAPTUS ?) DIFFUSUS, Hall. (n.s.)
Plate XVIII, figures 1-3.

Description.—Stipe strong, rigid, gradually decreasing in width at each
bifurcation : bifurcations numerous, irregular, the stipe slightly bending at
each division, and the branches and branchiets strongly diverging. Sub-
stance of the fossil extremely compressed, obscurely corrugated ; cellulifer-
ous face flattened. Cellules apparently arranged ina single series along the
longitudinal centre of the branches in the form of minute indentations,
and leaving similar minute pustuliform marks in the impressions of the
branches ; cellules about thirty-six in the space of an inch.

This species differs from D. erectus in the more rigid and more widely
diverging branches. It occurs in a dark colored or nearly black shale,
associated with Graptolithus extenuatus, Climacograptus antennarius,
Retiograptus tentaculatus and Retiolites ensiformis.

EXPLANATIONS OF Figures oF DENDROGRAPTUS? (CALLOGRAPTUS ?) DIFFUSUS, Hall.
Puate XVIII.

1. A portion ofa broken frond from near the base. The test is removed in some
parts, showing celluliferous markings.

2. A fragment of another specimen with similar cell-markings.

3. An enlargement, showing the cell-apertures. The specimens are extremely
compressed.

Formation and Locality— Quebec group ; Point Lévis.

DENDROGRAPTUS GRACILIS, Hall. (n. s.)

Plate XVIII, figures 5, 6.

Description.—Frond diffuse, numerously branched. Branches very
slender, extremely elongate and sub-pendulous, celluliferous on one side ; :
the cells are arranged in an apparently sub-alternate order, or have assumed
this order during the compression of the specimen. Surface striated: cel-
lules deeply indenting the margin of the branchlet, and the outer margin
furnished with a mucronate extension.

GRAPTOLITES. 133

This species is well marked by its extremely slender branches, which
are distinctly serrated, while one side is strongly striated, and the deep
indentations give a semi-articulate character to the branches.

Several fragments of this species have been found associated with
Callograptus elegans and C. Salteri, but none more nearly entire than the
specimen figured.

EXPLANATIONS OF Figures oF DENDROGRAPTUS GRACILIS, Hall.

Prats XVIII.

5. Two of the larger branches with their sub-divisions, of the natural size.
6. An enlargement from one of the branchlets, showing the striate surface and
the deep indentation of the cellules.

Formation and Locality.—Shales of the Quebec group; Point Lévis.

Genus CALLOGRAPTUS, Hall. (m. g.)

Gr. Kaddos, pulcher, and ypapw, scribo.

Generic characters.—Flabellate fronds, with numerous slender bifur-
cating branches proceeding from a strong stem or axis. Branches and
divisions celluliferous on one side, the opposite side striate ; sometimes dis-
tantly and irregularly united by transverse dissepiments. The non-
celluliferous side sometimes presents a semi-reticulate appearance.

The aspect of these fronds is intermediate between Dictyonema and
some forms of Dendrograptus ; but they have not the regular reticulate
structure of the former, while the sub-divisions of the branches are quite
similar to some of the species of that genus. In the mode of branching
and the form of cell-apertures, the present genus is quite different from
the typical species of Dendrograptus.

The slender branches and minute points which indicate the cell-apertures
render it impossible, with the specimens in my possession, to determine
satisfactorily the characters of the latter: they appear as simple oval
impressions upon the surface of the compressed branches.

It is possible that some of the species of this genus may have grown in
funnel-shaped fronds, as Dictyonema.

134 CANADIAN FOSSILS.

CALLOGRAPTUS ELEGANS, Hall. (n. s.)
Plate XIX, figures 1-4; and Plate XVIII, figure 4.

Description.—Frond broadly flabelliform. Stipe short, flexuous, swelling
at the base or root. Branches originating near the root, becommg numer-
ously subdivided, the divisions slghtly divergmg or nearly parallel, while
the whole expands to a somewhst semi-circular form when entire. After
the second or third bifurcation the branches become very slender, and con-
tinue of nearly equal width. Non-celluliferous face strongly striated,
slightly swelling at the cellules: celluliferous face striated; the cellules
arranged alternately on the opposite margins, parallel or slightly diverg-
ing, and opening in a projecting process or cell-denticle, of undetermined
form.

This species differs from Dendrograptus fruticosus in its more regu-
larly-branching habit, less divergence of branches in mature specimens,
shorter stipe, and more regular flabellate form. It differs from D. flex-
wosus in the more numerous, more slender, and less diverging branches
and branchlets. From both it differs in the form of the cells, and in the
strongly-striated non-celluliferous face of the frond. In young individuals
the branches are often much more divergent, but the striated surface and
the arrangement of the cellules correspond in all.

The specimens of this species occur in a fine grayish slate, associated
with Graptolithus nitidus, G. constrictus, G. bryoncides, and G. octobra-

chiatus.
EXPLANATIONS OF FIGURES oF CALLOGRAPTUS ELEGANS, Hall.
PuatTe XIX.

1. A fragment ofa frond, natural size.

A nearly entire flabelliform frond. The two shaded lines running nearly ver-
tically through the figure, are due to faults or slips in the slate, causing a
slight overlapping of the laminz, and an interruption of the continuity of
the frond.

3. Anenlargement, showing the lateral connection of the branches at irregular
intervals.

4. A further enlargement of the non-celluliferous side of a bifurcating branchlet,
showing the striated surface and a semi-articulate structure.

Puats XVIII.

4, A fragment which is more lax and spreading, with shorter branchlets
than the ordinary specimens, but having similar strie, and a similar arrange-
ment of cellules.

Formation and Locality.—Quebec group ; Gros Maule.

GRAPTOLITES. 135

CALLOGRAPTUS SALTERI, Hall. (a. s.)
Plate XIX, figures 5-8.

Description.—Frond spreading or flabelliform above. Stipe below the
branches and base, unknown. Branches numerous, undulating, bifurcat-
ing: divisions very little diverging ; branches closely arranged, the space
between them being usually less than the width of the branch. Non-
celluliferous face smooth, or obscurely and interruptedly striate ; cellu-
liferous face with the cellules alternately on opposite margins, producing
swellings of the branch at these points, and an undulating or tortuous
direction. A few of the branches astomose, or an are sometimes con-
nected by a short transverse bar of the same width as the branch. This
does not appear to be a constant character.

This species has the same general form as C’ elegans ; but the branches
are wider and less diverging, and obscurely or not at all striated. The
zig-zag direction of the branches forms also a distinguishing feature. The
stipe, which is not preserved in the specimens examined, was probably
short, branching from near the base. ‘This species occurs with C. aleg Jans
and its associated graptolites mentioned above.

EXPLANATIONS OF Figures or CaLLoGraptus Sauter, Hall.
Puate XIX.

5,6. Fragments of two distinct fronds; one showing the celluliferous side, and
the other the non-celluliferous side.

ue An enlargement from the non-celluliferous side, showing a few transverse dis-
sepiments at irregular intervals. The figure has the same degree of
enlargement as fig. 3 of C. elegans.

8. A farther enlargement of a bifurcating branchlet, showing the cell-apertures.

formation and Locality.—Quebee group ; Gros Maule.

136 CANADIAN. FOSSILS.

Grenus DICTYONEMA, Hall..

Gr. Sixrvoy, rete, and ynua, filum.

(Dictyonema, Pal. N. Y., vol. ii, p. 174, 1852, and Geol. Survey of Canada, Report for
1857, p. 142. Grapropora, Salter, Proc. Amer. Assoc.; Montreal, 1857.)

Generic characters.—Fronds consisting of flabelliform or funnel-shaped
expansions (circular from compression), composed of slender radiating
branches, which frequently bifurcate as they recede from the base.
Branches and subdivisions united laterally by fine transverse dissepiments ;
exterior of branches strongly striated and often deeply indented; inner
surface celluliferous or serrate, as in Graptolithus.

The general aspect of the species of this genus is like that of Fenestella,
both in the form of the fronds and bifurcation of the branches. . Some of
the species have heretofore been referred to that genus, and others to
Gorgonia. They may be known from either of these genera by the striated
and serrated corneous skeleton, and by the absence of round cellules ; which
latter character, with a calcareous frond, marks /enestella.

oe

DICTYONEMA IRREGULARIS, Hall. (a. s.)
Plate XX, figures 1, 2.

Deseription.—Frond spreading, diffuse. Branches lax, frequently bifur-
cating; bifurcations unequal ; branches equal to one half the usual width of
the interspaces, or a little less ; connecting filaments generally slender, ex-
panding at their junction with the branches. Fenestrules extremely irregular
in form and proportions, varying from a width greater than the length, to
a length three or four times as great as the width; those with a length and
breadth nearly equal, often appear hexagonal. Near the base of the frond,
the fenestrules are sometimes elongate and triangular. Cellules unde-
termined. Surface without distinct organic markmgs. Branches arranged
in the proportion of from twenty-five to twenty-eight in the space of an
inch.

This species is much smaller than either of the others, scarcely equalling
in dimensions the D. gracilis of the Niagara group, from which it differs
in its more irregular form and diffuse habit. In one specimen there
appear to be some identations upon the stone, indicating minute cellules,
but they are too obscure for satisfactory determination. This species has
been seen only in small fragments: the entire frond is unknown.

GRAPTOLITES. 137

EXPLANATIONS oF Figures or DicTYONEMA IRREGULARIS, Hall.
Prats XX.

1. A fragment from near the base of a frond.
2. <A fragment from the outer portion of the frond.

Formation and Locality.— Quebec group ; Point Lévis.

DicTYoNEMA ROBUSTA, Hall. (. s.)
Plate XX, figures 3, 4.

Description.—Frond large, spreading, extremely robust. Branches wide,
strong, bifurcating: bifurcations shghtly diverging, the interspaces about
the same width as the branches. Fenestrules large, elongated; the length
from seven to nine tenths of an inch, and the breadth from one twelfth to
one seventh of an imch. The transverse connecting filaments compara-
tively slender: cellules not determined. Surface smooth or obscurely
striate.

The specimens of this species before me do not admit of a more complete
diagnosis than that above given. It differs from any other species known
to me in the great strength of the branches, and in the very elongate
fenestrules; while the dissepiments or connecting filaments are usually
comparatively slender. The divisions of the branches diverge but little, and
the frond does not appear to have been abruptly expanded. It occurs on
the hard shales with Graptolithus rigidus.

EXPLANATION or Ficures or DictyonemA RozgusTA, Hall.
PuaTe XX.

3,4. Fragments of two different fronds. In some parts of the specimen fig. 3, and
in all of fig. 4, the branches are extremely flattened and attenuate.

formation and Locality.—Quebec group : Point Lévis.

138 CANADIAN FOSSILS.

DICTYONEMA QUADRANGULARIS, Hall. (n.s.)
Plate XX, figure 5.

Description.—Frond large, robust. Branches lmear, nearly parallel,
rarely bifurcating: branches about five hundredths of an inch in width, the
interspaces having an average width of eight hundredths of an mch. Fen-
estrules quadrangular, length and breadth usually nearly equal: con-
necting filaments nearly as wide as the branches, expanded at their
junction with the latter, so as to give an apparent sub-hexagonal form to
the fenestrule. Cellules not determined. Surface free from any charac-
teristic markings.

This species is very distinct from the two preceding, and from nearly all
other species, by the almost parallel direction of the branches. A fragment
an inch and a quarter wide by three inches long, shows not more
than four or five bifurcations. The apparently hexagonal form of the
fenestrules may be due m part, or entirely, to the breaking or wearing away
of the margins of the stipes, or of the connecting filaments, or of both.
The short equilateral fenestrules form the most promiment and charac-
teristic feature. It occurs with the other species just described, and with
Graptolithus rigidus, in the same hard shales.

EXPLANATION OF Figure or DICTYONEMA QUADRANGULARIS, Hall.

PLATE XX.

5. <A fragment of a frond, of natural size.

‘

Formation and Locality Quebec group; Point Lévis.

DictyonEMA Murravi, Hall. (a. 8.)
Plate XX, figures 6, T.

Description.—Frond very large, gradually spreading from its origin.
Branches strong, width from five to eight hundredths of an inch, infre-
quently bifurcating; divisions little diverging, the interspaces being little
wider than the branches. The fenestrules have a width of eight by a length
of eleven hundredths of an inch. The connecting filaments are wide at

GRAPTOLITES. 139

their origin or union with the branch, and slender in the middle; from
about one third to one half as wide as the branches. Cellules undeter-
mined. Surface smooth.

This species is associated with D. robusta. It is a less robust form,
the branches are not more than one half as wide, and the fenestrules not
more than one third the length of those in that species, while the connecting
filaments are quite as strong. ‘The specimens are extremely compressed,
and the character of the cellules cannot be determined.

While the preceding species all have the characteristics of true
Dictyonema, in none of them has the base been discovered, and the entire
form of the frond is therefore unknown. From the strong growth of all of
them, and the nearly parallel direction of the branches, we must presume
them to be fragments of very large fronds.

ExpLANATION oF Figures or DictyonemA Morrayi, Hall.
PuatE XX.

6, 7. Fragments of two fronds ; the figures of the natural size.

Formation and Locality.— Quebec group; Point Lévis.

Genus PTILOGRAPTUS, Hall. a. g.)

Gr. rriAov, pluma, and ypadw, scribo.

Generic characters.—Frond plant-like, rooted ? simple or branching.
Branches and branchlets plumose, the pinnules rising alternately on opposite
sides of the branches ; celluliferous on one face only: branches cylindrical. ,
or flattened. Substance corneous, dense ; apparently smooth exteriorly, or
corrugated by compression, or during fossilization.

In general habit this genus resembles the modern Plumularia, and
its mode of growth was probably similar. We know at the present time
two species, one a slender and delicate form, the other more strong
and coarse, and differing in its irregular mode of branching; while
at the same time the smaller branches and pmnule resemble the other
species. The cellules are distinctly confined to one face of the pinnulee ; but
whether arranged in a single linear series, or in alternating order, cannot
be satisfactorily determined. Both species are in soft shales, associated
with Graptohthus Logant, G. quadribrachiatus, G. arcuatus, G. Bigsbyi,
and others.

140 CANADIAN FOSSILS.

PTILOGRAPTUS PLUMOsUS, Hall. (n. s.)
Plate XXI, figures 1-4.

Description.—F ond bi-pimnate, branching. Branches slender, plumose ;
the axis round and smooth on the non-celluliferous side, and grooved on the
opposite side. Pinnules simple or rarely divided, alternate, long and
slender, flexuose, rising at an angle of 40° to the axis. Cellules minute,
arranged upon one face of the pinnules.

The entire form of this species is unknown : the branches appear to have
been rounded, solid, and very gradually tapering. The pinnule are slender,
linear, maintaining their width to the obtuse extremities: they have
sometimes a length of about five eighths of an inch. Near the base they
are solid ; beyond this they are flattened and slightly rugose (as if from
contraction), and preserve very little substance. _ It has not yet been satis-
factorily determmed whether the cellules are arranged in a single linear
series on one side of the pinnule, or in a double alternating series.

EXPLANATIONS OF Figures or PTILOGRAPTUS PLUMOSUS, Hall.
PiatTe XXI.

A fragment which is three times branched.

A slender simple branch.

An enlargement from the specimen fig. 1.

A further enlargement of a portion of the same; some of the branches showing
markings like cell-apertures.

moo bo et

Formation and Locality—Shales of the Quebec group; Point Lévis.

PTILOGRAPTUS GEINITZIANUS, Hall. (n. s.)
Plate X XI, figures 5-8.

Description.—Frond numerously and irregularly branched. Branches
thick and strong, irregularly bifurcating. Pinnule broad and strong,
closely alternating on opposite sides of the branches. Cellules large,
arranged on one face of the pmnule: non-celluliferous side smooth, or
corrugated from compression.

This species differs from the preceding in its stronger and coarser habit,
its more frequent and irregular branching, in the broad flattened branches
and the broader pinnulze, of which there are about six in the space occupied
by nine in the other species. The cellules are stronger, and apparently
more distant.

GRAPTOLITES. 141

EXPLANATIONS OF Figures or Prinograptus GeErniTzianus, Hall.
Puate XXI,

A branching fragment showing the celluliferous side.

A fragment which is irregularly branched, showing the non-celluliferous side.
A single branchlet of the same species.

An enlargement from fig. 5, showing the cell-apertures.

DTD %

Formation and Locality —Shales of the Quebec group; Point Lévis.

Genus THAMNOGRAPTUS, Hall.

Gr. Oauvos, frutex, and ypadw, scribo.

(THamnocraptvs, Pal. N. Y., Vol. III, p. 519,* 1859.)

Generic characters —Fronds consisting of straight or flexuous stipes
(growing singly, or conjoined in groups at the base ?), with alternating or
widely diverging branches: branches long, simple or ramose, in the same
manner as the stipe. Substance fibrous or striate; the main stipe and
branches marked by a central longitudinal, depressed line, indicating the
axis. Cellules or serratures unknown.

THAMNOGRAPTUS ANNA, Hall. (n. s.)
Plate X XI, figure 9.

Déescription.—Stipes slender, linear, undulating. Branches filiform, long,
flexuous, regularly alternating on opposite sides: the distance between the
branches on the same side is about fifteen hundredths of an inch, giving half
that distance on the main stipe between the origin of the branches. At
the base of each branch, the stipe diverges in the opposite direction,
making an angle of 30° with its previous direction. The angle between
the stipe and the branch measured on the lower side is about 130°, and on
the upper side 80°, showing a divergence of 30° in the direction of the
stipe. .

* A description of this genus, with other graptolitic genera, was read before the
American Association for the Advancement of Science, at Baltimore in 1858; but the
paper was not sent infor publication, and only a newspaper report of it was given.

142 CANADIAN FOSSILS.

The branches are flexuous, filiform, and as far as traced, simple ; rounded
or somewhat flattened as they occur in the stone. The substance of the
stipe or branches does not show cellules ; and the markings are groove-Jike
depressions in the stipe for a short distance below the base of the branches.
The test is corneous, black and shining.

This species differs from JZ. typus of New-York, in its less rigid
appearance, flexuous stipe, and more diverging branches.

EXPLANATION OF Ficure oF THAMNoGRaPTUS ANNA, Hall.
Puate XXI.

9. A fragment of the species, of the natural size.

Formation and Locality.— Quebec group ; three miles above the mouth
of the river Ste. Anne.

SUPPLEMENT.

DESCRIPTIONS OF SPECIES FROM THE UTICA SLATE, INTRODUCED
FOR COMPARISON AND ILLUSTRATION.

GRAPTOLITHUS FLACCIDUS, Hall. (a. s.)
Plate II, figures 17-19.

Description.—Frond consisting of two slender linear flexuous stipes,
which are widely divergent from a small short obtuse radicle. The stipes
at their origin are gently ascending, and then curve broadly backwards
or downwards, and maintain throughout their entire length a curvilinear
direction ; stipes cylindrical near the base, and flattened in their exten-
sion. Surface smooth, or with striz: so fine as to be invisible under an
ordinary lens. The diameter of the stipe varies from two hundredths near
its origin, to four hundredths of an inch in the fully-developed parts, main-
taining this width to the extremity: more than one half of the width is
occupied by the common body. ‘Test comparatively thick. Cellules nar-
row ; from twenty-eight to thirty and near the base sometimes thirty-two
in the space of an inch; inclined at an angle of 20° or less to the direc-
tion of the axis. Point of the denticle or aperture obtusely rounded,
very rarely angular: cellules free throughout their entire length.

This is a very distinct and well-marked species, with slender lax stipes
extending four or five inches or more from the radicle. It occurs in large

144 CANADIAN FOSSILS.

numbers, the stipes lying intertwined among themselves upon the surface

of the shale. The cell-denticles are very minute; and near the base of

the stipe the surface appears as if marked by small punctured or indented

pustules. This pustuliform aspect seems to be due to the strong partition-

walls of the cellules, which resist the pressure, and retain nearly their

original form, while the adjacent parts become flattened. Farther from

the origin of the stipe the whole substance is extremely compressed, and

the cellules are only indicated by undulations in the margin of the stipe, |
which show obscurely the rounded cell-denticle. The cellules are almost

always upon the convex side of the curve of the stipe.

The proportions of the stipe are about the same as in G. tenuis, Hall,
(not Portlock) ; but that species has the stipes straight and extremely
flattened in all the specimens seen. In both species the cell-denticles are
rounded, or appear only as slight undulations of the margin; but in
G. tenuis, the number in the space of an inch is from twenty-two to
twenty-four. These, with the other differences, are very distinctive.

EXPLANATIONS OF FiGuRES oF GRAPTOLITHUS FLACCIDUS, Hall.

Prats II.

17. A portion of a large fragment of slate, with parts of several individuals upon the
surface, and showing the origin of eight individuals in the minute radicles.
Some of these are indicated by asterisks on the engraving.

18. An enlargement to three diameters of the radicle and stipe-bases, with the cellules.
From the point @ on fig. 17. }

19. A farther enlargement of a portion to show the form of the cellules, and the pustu-
liform appearances at the base of the divisions between the cellules.

formation and Locality.—Shales of the Utica formation; Lake St.
John, east from Blue Point.

GRAPTOLITHUS QUADRIMUCRONATUS, Hall. (a. s.)
Plate XIII, figs. 1-10.

Stipes consisting of simple quadrilateral tubes, which are celluliferous
on the two opposite sides ; the plain and the celluliferous sides being of
equal width im the middle, or half-way from the base to the apex, where
the stipe attams its greatest dimensions; celluliferous sides of the stipe

GRAPTOLITES. 145

gently mereasing in width from the base, with the sides parallel
above. ‘The base is narrow and somewhat obtusely pointed below. In
what appear to be mature stipes the greatest length is two and a half
inches ; the width, when flattened and showing two of the four sides, is a
little more than one eighth of an inch, exclusive of the cell-denticles.
Test corneous, comparatively thick, and without visible strie. A slender
axis marks the centre of the stipe, and rarely extends beyond the apex.
The cellules consist of simple notches or transverse slits in the opposite
sides, which are slightly dented in the non-celluliferous face, and each
angle or sinus produced into a slender, mucronate spine, making a range
of spines upon each angle, or four ranges of spines marking the entire
length of the stipe; about twenty-two cellules in the space of an inch,
the margin or lip slightly projecting.

The specimens of this species occur in great numbers upon the weathered
and fresh surfaces of some specimens of the Utica slate. Some are ina
well-preserved condition, others are partially preserved, and others con-
sist of moulds or impressions of the stipes. The specimens have been
compressed in every possible direction, sometimes parallel to the cellulrf-
erous face, giving the more natural expression, or that which is regarded
as the more characteristic of the graptolite (fig. 1); others are com-
pressed vertically to the celluliferous sides, so that the plain faces are
pressed beyond the margins of the cellules, giving the scalariform char-
acter (fig.3). In other specimens the pressure has been directed against
the angles of the stipe, showing one of the plain, and one of the cellulift
erous sides (fig. 2). The cellules in such examples extend half way across
the width of the stipe, and show the spines upon the outer margin; while
the spmes marking the inner margin are either compressed or broken off
Cig. 8), leaving their bases visible along the centre of the stipe. On
the opposite margin the mucronate spinules, marking the inner angle of
the opposite cellules, are shown, extending outward as far as those on the
opposite side, though that half of the stipe is entirely plain with an undu-
lating margin between the spinules. Sometimes on this side the spinules
may be folded beneath, and the stipe presents a continuous margin, and
has the appearance of a uniserrate graptolite, both characters being some-
times seen in the same individual (fig. 2).

In specimens which are compressed vertically to the non-celluliferous
face, the mid-rib or axis is distinctly marked, often throughout the entire
length of the individual, as a slender filiform body. The cell-partitions in
some specimens are well marked, but in the greater number are obscure ;
this condition probably arising from the thick outer test of the specimen.
The spinules originate in the smus or angle at the intersection of the lip
of the aperture with the body of the stipe.

146 CANADIAN FOSSILS.

Some other species besides this have grown as quadrilateraltubes. Those
specimens which show an undulated margin with projecting mucronate
points or spinules can be of no other form than that which is here described:
we have good reason to suppose all those with inequilateral stipes to
belong to the same‘form; and those with deep indentations on one side and
without cell-markings, except simple undulations on the other side, are
only another phase, depending upon the direction and degree of pressure.

The species under consideration, in its various aspects, illustrates more
fully than any other which we have seen, the effects of pressure in differ-
ent directions. The cellules, in form and in manner of opening upon the
surface, differ from such as Graptolithus pristis, and appear to be inter-
mediate between those of G. bicornis, = Climacograptus, and those of
G. ramosus.

EXPLANATIONS OF FIGURES OF GRAPTOLITHUS QUADRIMUCRONATUS, Hall.
Puate XIII.

Fig. 1. Part of a stipe compressed in a slightly oblique direction, still showing the
cellules'on the two sides.

Fig. 2. A stipe compressed more obliquely, so as nearly to obscure the cellules on
one side.

Fig. 3. A specimen compressed vertically to the celluliferous side of the stipe. !
Figs. 4,5, and 6. Enlargements from specimens, figs. 1, 2, and 3 respectively.

Fig. 7. Enlargement from a specimen where the solid axis lies near to one side.
Fig. 8. A specimen obliquely compressed, so that the mucronate points at one angle

of the cellules of the left side, are pressed through the test, and show on
the surface as a range of pustules. The axis is displaced, and seen on one
side of the centre.

Fig, 9. A diagram representing a theoretical longitudinal section.

Fig. 10. A transverse section of a stipe with the mucronate extensions of the cell-
margins.

Formation and Locality—Utica slate formation; Lake St. John, east
from Blue Point.

RETEOGRAPTUS EUCHARIS, Hall. (a. s.)
Plate XIV, fig. 9.

Frond spreading, nearly flat, consisting of numerous narrow lanceolate
elliptical stipes, attached to a common initial point-or axis, and bilaterally
arranged on two sides of a short funicle, which is four or five times bifur-
cated on each side.

GRAPTOLITES. 147

Stipes varying in proportions, the length being from three to five times
the width ; axis very distinct, undulating, and its continuation traced from
the radicle to the distal extremity, beyond which it extends in a mucronate
point. Cell-partitions distinct, alternating, essentially rectangular to the
axis, the cellules having their greatest development about the middle of
the length of the stipe. Margins of the stipe ornamented by short
mucronate points which alternate with the cell-partitions.

Surface of the test smooth or granulose.

EXPLANATION OF Figure or ReTeoGraPtus HucHARIS, Hall.
Puate XIV.

Fig. 9. The frond three times enlarged.

Pormation and Locality.—Utica slate ; Blue Point, Lake St. John.

PAGE.
RES ES or orifice of cells,.-....... 29 |
in G. nitidus, G.similis,ete. 29
oe in Dictyonema and Dendro-
STraptus, ~. .2-=5.--..--- 29
ue OQRIT MEMS Otsooagnnooe sac 30
ANE, soso n0g0ca00900 009000R8 19, 21, 46

Barrande, 6, 16, 21, 22, 27, 28, 40, 45, 46,

47, 62, 63, 78, 81
aes (RISES) hooes pp goun Oe nOoOOe 6, 60, 63
JESUITES) 5. OOD A OOOO ODES DISCOm 64
Isa, Sa Solnemcean posdoonousosos= 59
SEOTOR MATa nvelelolereisl(eie s\0) «/==\s) « ells] s!a\n.=\= 60
IBrOmipederisiiiila eo cs + = sie « csocoaoeslh (HU
BUTHOGRAPTUS, ..... s06n80 000000 Salli, 2
B. IARIGS, SOaddooobg obobe Goo On 18
CALLOGRAPTUS, ..... 12, 30, 31, 39, 48, 133
Ce (Dendrograptus) diffusus.... 132
C. el€gans,. oo 1.6.05 = 133, 134, 135
C. Spilieitkas soeogedse conc lBR} Us
Campanularia,........... 33
Cells, their form and mode of develop-
TTA C TA lisjatlotterate ta) © = =) <.-1s) «51 = 24, 43, 45
cay species of Graptolithus,..... 27
FO TORO AUOCTAPLUS, «6.262 se. » ace, ahs
4 itr ID BMGROaTEy TE} onlooobo aObe 29
ELM TCUYONCM A raicve ce 0 ole . 29
EMO NEWOLLAD CUS, «51016 «10 <.5) 5 . 29
“« ornaments of the margins of,. 30
Cells, cellules or calycles,.......... “21, 30:
Weplialopoday acts ccc 2+ cir ccs sas 6 556
Ceratophytay cents cic s 2 sss « Sone 6
CLADOGRAPTUS,...... Sag obpooco oe celle 233
CrIWACOGRAPTUS. 25 scsc0 5 as <= oc 111, 146
C. antennarius,......- 111, 112, 132
C. bicornis, 20, 21, 27, 28, 49, 57, 111,
112
C. SHIA soedbcabcoodagaEe 56. HU
Cr typicalis, ..... se6eseacoes enigtD
Common bodys aclercjasenieels eis ele 29 oe
Common canal,......... ethene! 21 2S
@RISIA; «ac lsetesioeterers sobode sodeodse 13
IDE GUE Socso cpcsa5ugeo denn oe 33

DenprocraPtus, 10, 12, 21, 29, 30, 31, 37,

39, 48, 49, 126, 133
D. GUUS, Gaossacecss ac 129, 130
D. erectus. i: sa eee 129, 130, 132
D. HexMOSUS ater eee 127, 134
D. fruticosus, 127, 128, 130, 131, 134
D. fee Moga oodavcusaaue 132
D. all ianush cirri Gaeiboe E 11, 127
D. SEStHa tus, isc cee eRe 129
D. (Callograptus ?) diffusus,... 132

PAGE.

DICHOGRAPTUS,-.++-+-+e+s6: veee 41, 42, 43
DICRANOGRAPTUS, ..-++-esees-0e es Says Tha
D. CIGMEM IE Ss ooo nocoboceons 57
Dz. UPCTMNS po uo osoncccjDac oS 57
D. TAMOSUS, 2.0 ee en ae cine nee 57
D. ACME soso Goan bocasazocs 57
DictyonEMA, 12, 18, 21, 23, 30, 31, 32, 39,
48, 126, 133, 136, 139

D. PARA AIS os ao Soon ac scdas 136
D. GACH, San0cdocooedeboooe 136
D. MER Ao aonsdssooa dace 138
D. ane ete Bictever apepctoterers 138
D. peop: Sig snack ane. 12
D. TObUStA, .....eeeeee---s 137, 139
DIDYMOGRAPTUSS « «<.3)< jects mecis= 41, 42, 46
D. GATIMOSNEE sooo Se ado sda: Sods 86
DipnLoGRaPtus, 15, 35, 40, 41, 44, 45, 46, 48,
109, 116, 118, 125

D. PRUUCILAS) fo ofotepel-f tally soca “Alii
D. pristiniformis, ......-..---- 110
D. rectangularis, .......- ewes) 40
DIBRION retis/oe aie ssisiete teins 15, 40, 41, 109
Disc (central), ......+ .e- alesis = « 20, 42
LPENO, dosanodcopDpe Sos abo>seacdsse 64
Buchwald ssjeye eleie wo «ele, -\nial=inlejoid= <= 40, 60
ID AMADIS sooo SG OcbdbOaDE Sb oo noZkl ail, he
FENESTELLA, -.+. 4-0. 586500909505 39, 136
INMACIE Se nanesscococdae oo sogéoa 6: 19
Fucoipes dentatus,.........+-+ .--84, 110
F. S€CALiINUS,.... 2 s,c0e- ee eesees 64
F. Sand, s-Beode cooepoosaoeadc 84
Geinitz, 5, 28, 40, 41, 46, 47, 60, 61, 63, 78,
81

Germs of Graptolites, ........2.4-- 33, 34
GHOSSOGRAP TUS) = 0s. jlalseciie ele =iaei=y= 41, 43
GORGONTAD 2 eet eer rustic 136
GRaPTOLITHUS, 7, 28, 40, 42, 48, 68, 115,
117, 136

G. abnormis,........ Sen 320855 106
G. HEMI galce cond soo oS On aT 20, 93
G. SANCUSO MUS ne ie eta 110

G. antennarius (Climacograp-

UNS) Rom yownmeoa soos oSd 32, 112

G. armatus,....79, 92, 101, 129, 139
G. bicornis (Climacograptus),.. 20,
21, 21, 28, 29, 30, 32, 34, 38, 39,

45, 112, 146

G: pinduss. 2 ssqg= 29, 41, 73, 83, 93
G. Bigslylneeieeeaes 48, 86, 129, 139
G. bryonoides, 8, 41, 42, 48, 70, 78,
83, 84, 85, 89, 95, 96, 128, 134

G CAdUCeUS Hp ieiie a eter 41, 42, 87
G. Clintonensis, ..-.....- 25,27, 28
iG. constrictus,.....-- ~» (6, 85, 134

150 INDEX.
PAGE. PAGE.
GRAPTOLITHUS ColonuS,.......+++.+-. 21 Graproritip#, Geological and geogra-
CLUCITET or ele oar lels sleet: 92, 93 phical distribution
G. denticulatus, ........ 88, 93, 129 OG srena co Sdoao.5¢ 51
G. divaricatus,........-...-- 14, 46 a: Historical notice of the
G. divergens,.....«- -- 12, 13, 23, 24 genus Graptolithus,59-64
G GUD, : 5's wale ww sere ace a Mode of existence of,.. 38
G extensus,....27, 29, 76, 80, 83, 85 ns Nature and form of,.. 5
G. extenuatus,...+...+++.--> 75, 132 a Nature and ornaments
G MaCCIMNE enchaeertneietee ire 143 of the test of, 21, 30, 32
G. flexilis, 11, 42, 103, 106, 107, 108, a Reproduction ia the,.. 32
109 ue Synopsis of the genera
G. foliaceus, ........ ese s cence 44 OAecgenocds od soc: 50
G. LOM Pearcleitateletaleteteeyelsielets ite 2c ce Synopsis of the species
a. Forchhammeri,........-..- 41, 46 of, in the di
G fruticosus, ...... Anon eawdd 205 SE PROM ates once 65
G. furcatus,.. ie 1G, 40, 41, 46 a Table showing the ver-
G. creme eavclsiee sasha eclw'= ss Al tical distribution of
G. QEMINUS, «eee eeeeeeeeee 41, 46 the genera of,..... - 55
G. PTAC. eote es ces 13, 14, 23, 43 us Table showing the geo-
G. Plea dieere ate rele 8, 38, 92, 93, 94, i; logical distribution
G. hirundOwcerestecmieetyste cia «6 of the species of,... 56
G. imdentusye. life's = = > 78, 79, A a Zoological affinities of, 6
G. Logani, 9, 20, 36, 38, 42, 98, 99, | GRAPTOPORA,..-.-++-.eee seer scenes 136
100, 101, 103, 106, 129, 139
G. Malesijs. cota ntien ess ; 42, 53 | Halles te see cece scene eee 61, 62, 63, 64
G. multifasciatus, ........++- TOS99: | Harknessterce srr settee itera 40, 62, 81
G. Murchisomi;..- 0225.2. .:.-. Al, 46 | Historical notice of the genus Grapto-
G. INGSSOMT, 58 aft Scions wires wos 81 HGhW6)! pi. osc cote oe 59, 62
G. NitidUs; i oe. a 29, 69, 71, 85, 134 | Hisinger, .....000s.00 ceeeeece wees 40, 60
G. octobrachiatus, 8, 27, 29, 96, 101, | Hall (B.).....--- eee ces eee cere ee eeee 60
107, 134 | Hydroidea, analogy with graptolites, . 33
G. octonarius, ......-+.s6--- 95, 96
G. OVAUUE RE ec sdcicn eacds aes L2SMl elmantrale POUNt terieereletsersie|tielaleters Sonos,» Je)
G. MIRED ood AOtoO OUCRIE 44,109 | INocAULIS, ---.----- Srctaferd) fe aetna 18, 49
G. [YAU od cone ily CR tO asker eAS ip Ie plumosus,....-.... ofe oisuiniele 18
G. pennatulus,..... 1, 29, 73, 82, 83
G. PIU. hah ee sss ess 27; 46" | Mimnheus ths vaae See ee eee Pe Pye NS
G. pristis (Diplograptus), 15, 32, 34, | Logan,......++++++.sseeee rmapdcoios (ee!
36, 37, 40, 44, 45, 46, 109, 110, 146
G. putillus (Diplograptus), 27,44, 75 | Marmora, General de la,.....+..+++- 63
G. pristiniformis,....37, 84, 109, 110 | Mather,......0... 02+ -seeeeeee caylee
G. quadribrachiatus, 30, 41, 71, 77, | McCoy,......---. 33, 40, 45, 46, 62, 64, me
G8, 89,°91,:93; 129, 139 || McCrady;nrcia-'o'are's'stetetetate ate B
G. quadrimucronatus,.......--- 144°) Meneohimi Sets ls eee velelen ole "40, 63
Be ramosus (Dicranograptus), 15, 31, | MonoGRapTus,.-..- Bhs mis cole efahaielistvtets 4, 65
34, 40, 41, 45, 46, 112, 146 | MonopRioN,......+...004- veee e+ 40,41, 65
G. ramulus,..... Sdo dood co0dobe HUA BUEN oon Goanomc hole ale cree ss fatale 6
G rectangularis,.......+..+-.+ 112 | Murchison, Sir R. mis oe es 6, 40, 60, 61
G. Richardsoni,.....0.0++++es- LOW | My rianitesy sc. ctes. scteninints o wie eine eno
G. rigidus, 42, 105, 107, 108, 137, 138
G scalaris,..... ..eee5, 27,111,112 | Nature and form of graptolites,...... 5
G. SGiad PpaecoOoO Gnd 2.0000 Foe 41’ | NEMAGRAP TUR. ( 2 5: ott tacel see eater 43
G. serratulligyac.c' wet st ml 1, 78°} IN Capillaris;.%%% ne oe 0 eae ee
G. sagittarius, 7,10, 41,44, 78, 81,98 | N. CLEMATIS, S26 ef eee cel sie eid tare ee
G SEOMLANG: <1 0 15 sisi es F 1, 41, 46 | Nemapodia,....... sjaebe Gaels eyajatatales eames
G BEAUTE eg eign on peaeeos (8, ci | Nemertitesss..ttrselta. ale siete ela teVelarelapete aaece
G tentaculatum,......-.....--- 116 | Nereites,..... sogge aod ac Pe meiccyAor 2
G FENMIG; «3's 3% cioee ate .--.- 76, 144 | NEREOGRAPTUS,.......- = sda el TS oa
a. teretinsculns,......+e.+++45, 112 | Nicol,..-.ssseeeeesse- eee aseecees 40, 62
G HESTISS iacai eretare Gee eects ar youll) Nilssonns,tavestclectars eters stars Societe: 6, 60
G WIT SUIAtOS, © ais © x ter oleic 72 | Notice, historical, of the genus Grap-
G. IWihittiel di, <-%,ate claus 81, 33, 36, 37 tolithus,.........sse- COO aie:
GraProLitipa, Analogy of, to 'Ceph-
BLO POUR ys. 2 melee = ele Cin} (OMDHAMIO Eph sietctelevelsie Sieyaleie)e"s winlsislely MON
“ Development in the, .. 32 | QO. fruticosa,.......... vases) OG
ee General characters of,, 40 | Ornaments of graptolites,..........30, 32

INDEX. 151
PAGE. PAGE
Pennatulide, .ccceces cencecnas oes .6, 32 | Sacs, reproductive,...... areal ercvaheve ais 32, 33
IRSHMIOMMIES 6 Gado DgdGogsHe Couns. oo00G 109) | Salter,.<.... 40, 41, 42, 46, 61, 63, 64, 136
elaWUbishocoalouc a faticteherseclatonetsiels) evel GIS | Scharenberg\ carotid eee eee 63
PHYLLOGRAPTUS, 16, 23, Heb Eerh Giijsish d| SOTO Nal eRe mona Gambon oohwdocar 5, 59
39, 48, 87, 88, 109, 118 SSA Snes a Sdh0bnoo0 acd dO 61
P. angustifolius, jadcene 16, 124, As) || Sectinleywecooocacs oe 24, 25, 32, 33
BP. AMT) cogoas Keo ode oooo aD ES 124 | Sertularide,...... Sig086 0 Raia lomoe 6% 32
Bs ilicifolins, 31, 83, 85, 120, 121, 123 | SrauRograpTus,............ doubsose 23
1. SUMMING eeugertercyaacis: <\stcye-e. o/nlotn 86, 87 | Stipe, its nature and form,........... 21
P. Gennseen vera, 119; 129198, 197.) Suess,-<00..2..6...0 cae hoe 6, 62
Plumularia,...... dobdotoves ne 25, 32, 139 Synopsis of the genera of Crain:
Poxtlock-su-r sosdoossscoonr 6, i, 40, o Obed cecdmoon toma dee sdscbad be on 50
Polypiaria, 20O00, -ocoouddnobOBHbOGeD Synopsis of the spec from the Que-
Pmowiiy De Jel, UA coaolgseoeubupGuoGD 52, 62 DECLELOMPs jah oferelereievorervarbersete 65, 68
EP TMEOGRAPMUS seis) ofele cic!) 6101<\«)- 5495139
Ptilograptus Geinitzianus,........ -- 140! Table showing the geological distribu-
RB: plumosus, ..... anovg00 DOOD 140 tion of graptolites in Canada
and the United States,......... 56, 58
Quenstedt, .......seeeeee seen. ---5, 60 | Table showing the vertical distribution
‘ of the genera of the family Grap-
Radiata, Graptolites referred to,..... 32 tolitide: Mesum awning ae 55
Radicle or initial point in graptolites,. 19 | Test of graptolites, its nature and
RASTRITES, «++... 16, 17, 25, 26, 43, 42 CHINN, GoboonasooG0 edd 21, 30, 32
. Barrandi,....... pte e eee es LGC ERAGE AP PUNT nihsin'uie see naiy ioe oi 41, 42
Reproduction in Graptolites,.. 32 | 'THAMNOGRAPTUS,..++2+0000000- 17, 49, 141
LSTEIDOIRE. 05 d ooo oo O Og O ebb Uoor 39 | p. AIT ge coco pe psn a ee iS aay
Reriogrartus, 16, 19, 22, 24, 30, 31, 32, | p, WME Geoéauccooconcduaeus.: ill
36, 37, 38, 39, 47, 109, 113, 115, 120
R. GWG IME cogadnor 38, 68, 117, 146
R, tentaculatus,......... 67, 115, 116, 132 Bi aay i UE apne Rane oe e
ReTIOLITES, 16, 22, 23, 28, 29, 30, ah 32, & DS aise y ban eet bse nai
Boy STG Be) 46, 47, 109, 113, Ii 5, 116, THe
R ensiformis, un eC 111, 114, TSG || Maeno Coop obo hdndbonoodoouc 5, 59
R. Geinitzianus,..... .....114, 116
R VENOSUS, --+.eneessee-eee-+ 114 | Zoological affinities of graptolites,... 6

ae Te

bh tyil ae)

419) snl
MienR eS, SAM

PLATES.

Plates A and B illustrate the structure of the Grapto-
litidee as referred to in the Introduction, Chapter I.

Plates I to XXI illustrate the species of Graptolitidze
described in Chapter II and Supplement.

ik i,

‘ i) (
‘ ey a

EXPLANATIONS OF PLATE A.

CLIMACOGRAPTUS TYPICALIS, page 57.

See observations on C. (G.) bicornis, etc., pages 27, 28, 30, 45, and 111.

Figures 1—8 are enlarged to six diameters.

Fig. 1. A lateral view of the concave side, with the surface entire, showing the form of
‘the cell-apertures. ‘

«2. A lateral view of the same, showing the entire form of the cell-apertures.

“¢ 3. Lateral view of a fragment where the surface is exfoliated, showing the cell-

partitions extending downwards towards the centre.

“ 4, A longitudinal section made a little below the exterior surface, showing the cell-
partitions extending further towards the interior than in fig. 3.

“ 5, A longitudinal section through the centre, showing the cell-partitions reaching
to the central axis.

“« 6. A transverse section, showing the cell-partitions just within the aperture, and
the minute central axis.

“¢ 7. A transverse section made a little lower than in fig. 6, showing the cell-partitions
extending across the stipe on one side, and on the other side showing the
narrow triangular point near the centre.

“ 8. A section made diagonally across a crushed stipe, showing the folding (from
pressure) of two cell-divisions on each side of the centre.

““ 9. An ideal longitudinal section, showing the form and direction of the cell-parti-
tions and the central axis, (enlarged to twelve diameters).

GRAPTOLITHUS PUTILLUS, pages 27 and 44,

Enlarged to twelve diameters.

Fig. 10. A fragment of a stipe, showing the two ranges of cellules, their form, mode of
growth, and the unfolding of the exterior test along the line of the central
axis.

‘ 11. A lateral view of the same fragment, showing the cell-apertures and the flat-
tening of the exterior of the base of the next cellules in advance, and the
greater breadth of the cellules at the bases.

“ 12. A longitudinal section through the centre of the stipe, showing the double
cell-partitions and the double central axis.

“ 12 a. A transverse section cutting one cellule near the aperture and the other near

the base.

CLIMACOGRAPTUS BICORNIS, pages 20, 21.

(Graptolithus bicornis, Paleontology of New York, vol. i, page 268, and Geology of
Canada, page 200.)

Fig. 13. The lower part of a stipe enlarged to two diameters, showing the bifurcating
process and a central node or radicle.

“ 14, An enlargement to six diameters of a fragment which preserves in a very per-
fect manner the bozder of the cellules, and shows an undulating central
axis as well as the median ridge.

«15. The base of a specimen showing three spine-like processes, (two diameters).

“ 16. The lower extremity of a specimen showing a partially developed corneous
disc, (two diameters).

11. The lower extremity of another specimen, showing a more complete disc or
bulb at the base, (two diameters).

EXPLANATIONS OF PLATE A, continued.

Cuimacogrartus (sub-genus DicRANOGRAPTUS) RAMOSUS, pages 15, 31, 45, 46, and 112.

(Graptolithus ramosus, Paleontology of New York, vol. i, page 27, and Geology
of Canada, page 200.)

Fig. 18. The lower part of a frond in which the base is entire, with the bifurcation
above, (natural size).

‘¢ 19. The bifurcating portion, with a part of the simple stipe, showing the cells on
one side as they are usually seen when flattened in the slate. On one por-
tion of this there are oval pustules, which is a feature sometimes observed.
The opposite side gives the appearance of the cellules when flattened and
compressed partially against the aperture, (six diameters).

“20. An enlargement from below the bifurcation, showing the more perfect form of
the aperture, with the spines proceeding from the exterior surface above
the aperture, (enlarged to six diameters) ; see page 31.

21, A young individual or germ, supposed to be of this species, showing the basal
processes and the partially developed cellules at the upper part. See
page 34.

Geolegieal Survey of Canada,

Sir W. ff. Logan, Director. j
Decade 2. eas WOE Rieger a Plate 4
Graptclitide.

cer cece NETTIE TET TN DIET RES

R.P Whitfield Delt

James Hall Descrip?

cae UE lak par

By ee, per eee (Pre a

EXPLANATIONS OF PLATE B.

GRAPTOLITHUS CLINTONENSIS, pages 25, 27, 29.

(Paleontology of New York, vol. ii, page 39.)

Figures 1, 2, and 4 are enlarged to six diameters, and figure 3 to nine diameters.

Fig. 1. A fragment from near the base of a stipe, where the cellules are less developed

6c

19

than in other specimens. The cellules are partially filled with mineral
matter and have an angular form.

2. A lateral view of a part of a mature stipe, showing the form of the cellules, and
the recurved extremities causing the apertures to open downwards. The
specimen is filled with mineral matter.

3. A front view of a part of the same stipe, showing the lateral extent of the cell-
bases and the expansion at the aperture.

4, A dorsal view of the same, showing a groove which indicates the place of the
solid axis.

5. A branch of DicryonEMA GRACILIS (page 29), showing the serrated margin indi-
cating cell-apertures; (enlarged six diameters).

GRAPTOLITHUS WHITFIELDI, pages 32, 33, and 36.

Figures 6-10 are of natural size; figure 11 is enlarged to two diameters.

Fig. 6. A stipe showing serratures, with a few partially developed reproductive sacs in

the upper part.

7. A stipe where the sacs are more fully developed.

8. A stipe with numerous reproductive sacs, some of which have apparently be-
come dehiscent, and exhibit numerous extremely slender fibres.

(In connection with one of these sacs there are two minute germs, one of them
lying beneath the sac, and the other just beyond its outer margin and barely
separated from its fibres. See fig. 11.)

9. A stipe with a few of the sacs remaining, and the bases of some others which
have apparently been broken off. One of these sacs appears to be attached
to the axis above the cellules and lying beneath the axis.

10. A stipe from which the reproductive sacs have been removed (by maceration),
showing only the marginal fibres by which they were attached to the axis
of the parent stipe. Some of these remain connected with the axis in
its extension beyond the cellules.

“ Il. An enlargement of a single sac, from fig. 8, showing the position of the two

germs.

EXPLANATIONS OF PLATE B, continued.

GERMS OF GRAPTOLITES.

Figures 12, 13, 14, 16, 17, 18, 19, are germs of Graptolites enlarged to six diame-
ters. (See pages 33 and 34.)

Fig. 12. A germ of a biserrate form, before the cellules have assumed distinctive shape.
The axis is extended, and the common body spreads on both sides in the
lower part, the cellules embracing the lateral processes, which are seen at
the base of most of the diprionidian forms, and extending along one side of
the axis above.

“ 13. A form similar to fig. 12, a little farther advanced, where the lower cellules
have begun to assume their proper form.

“14, Another form of germ resembling G. ciliatus; the ciliated processes are visible
beyond the limits of the sac, but the cellules appear not to have assumed
definite form.

“15. A young individual of G. ciliatus, (natural size).

“* 16. A discoid germ. This may be the central disc of a compound form of Grap-
tolithus.

“* 17. A germ showing the common body extended on the two sides of the axis, but
without any visible or apparent cellules.

“¢ 18. A germ where the common body or sac is much expanded on the two sides of
the axis, and the central portion is apparently becoming more solid.

“ 19. A germ where the solid axis is on one side; the species probably belongs to
the monoprionidian type.

RETIOLITES VENOSUS, pages 22, 47, 113, and 114.

(Palzontology of New York, vol. ii, page 40.)

The figures are enlarged to nine diameters.

Fig. 20. The exterior of the convex (?) side, showing the external axis and cell-parti-
tions, with the intermediate reticulate texture.

‘¢ 21. Another view, apparently from the interior (see page 47), showing an undulat-
ing or zig-zag axis, with cylindrical processes extending to the margins,
and short, apparently broken processes directed obliquely upwards. The
reticulate structure is not essentially different from that of the other side.

rarer,

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18.

20.

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23.
24,
25.
26.
27.

EXPLANATIONS OF PLATE I.
GRAPTOLITHUS NITIDUS, page 69.

A young individual with the radicle and the two stipes.

. The extremity of a stipe enlarged, showing the partially-developed cellules.
. A larger specimen similar in character to fig. 1, showing the pustules at the

base of the cellules. The extremities are not quite entire.

. A part of the left side of fig. 3 enlarged, showing the pustuliform elevations.
. An enlargement from fig. 8, with the cellules obliquely compressed and the

pustules obscure.

. Two smaller individuals, which, from juxtaposition and similarity, seem as if

they may have originated from a common base.

. An impression of a more extended form, proportionally narrower than fig. 3.
. A still narrower stipe, diverging almost rectangularly from the direction of

the radicle.

. A well-preserved small individual, enlarged three diameters.

GRAPTOLITHUS PATULUS, page 71.

. A specimen preserving the radicle, and a stipe on one side two and a half

inches in length.

. The distal extremity of a larger stipe. Some of the cells are filled with pyrites.
. A short stipe broken off near the radicle, showing the narrow form near the

base, and a width beyond greater than in ordinary forms.

. A part of fig. 12 enlarged.
. A part still further enlarged to show the strie parallel to the cell-apertures.
. An enlargement from fig. 11, where some of the cells are filled with iron

pyrites showing their extension almost to the back of the stipe.
GRAPTOLITHUS BIFIDUS, page 73.

A small specimen from the same fragment of slate with fig. 17.
An individual of ordinary size.
An enlargement of the upper part of one stipe of fig. 17.

GRAPTOLITHUS INDENTUS, page 74,

An individual of the natural size, the continuation of the stipes having been
broken off on ode side.

GRAPTOLITHUS EXTENUATUS, page 75.

A fragment of the stipe, natural size.
A portion of the lower extremity enlarged ; a part of the specimen retaining
the substance of the fossil, and a part being an impression in the slate.

GRAPTOLITHUS CONSTRICTUS, page 76.

A young individual, natural size.

An older specimen, the stipe broken off on one side.

A part of a much more extended stipe, but which is not wider than fig. 23.

A part of a stipe from Gros Maule.

An enlargement of the last, showing the form of cells, the cell-denticles or
apertures, and the characteristic apparent constriction.

Canada.

Shee Sir W. hogan, Director.
LIECAME F. ss 1 te
Graptolitidee.

Geological Survey of

Lewer

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ULM

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James Hall, Descrpt James Duthie, Sc.

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EXPLANATIONS OF PLATE II.
GRAPTOLITHUS SIMILIS, page 78.

Fig. 1. A very young individual of this species.
“9. An individual somewhat more mature.
“ 3. An enlargement showing the form of the radicle, and the cells near their
origin, with a non-celluliferous space between.
“ 4, A fragment of a longer stipe, which is imperfect at both extremities.
“ 5, An enlargement of fig. 4.

GEAPTOLITHUS ARCUATUS, page 179.

Fig. 6. A stipe of a small individual, more than usually curved.
“ 7, A stipe having a process just above and opposite the radicle.
“ g. A larger stipe, the cellules very clearly preserved.
“ 9, A specimen showing the stipes on both sides of the radicle, and preserving
their peculiar curvature very perfectly.
‘10. An enlargement of a portion from figure 8.

GRAPTOLITHUS EXTENSUS, page 80.

Fig. 11. A single stipe more than four inches long, with the radicle and base of the
opposite stipe.
“ 12. A fragment showing a part of the stipe on each side of the radicle, natural size.
“ 13. The radicle and adjacent cellules, enlarged from fig. 12.
“ 14, An enlargement of fig. 12 at a point about two inches from the radicle.
15. A fragment of a stipe where the cellules are distended by iron pyrites.
16. An enlargement from fig. 15.

GRAPTOLITHUS FLACCIDUS, page 143.

Fig. 17. A portion of a large fragment of slate, with parts of several individuals upon
the surface; and showing the origin of eight individuals in the minute
radicles. Some of these are indicated by asterisks on the engraving.

‘© 18, An enlargement to three diameters of the radicle and stipe-bases, with the
cellules. From the point a on fig. 17.

‘ 19, A farther enlargement of a portion to show the form of the collabess and the
pustuliform appearances at the base of the divisions between them.

Geologterl Survev ot Canada.
oir W. &. Logan, Director.

R Graptolitades

DPecade 7. Plate 2.

Lower Stluriaw. Guehee Group,

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EXPLANATIONS OF PLATE III.
GRAPTOLITHUS PENNATULUS, page 82.

Fig. 1. A young specimen with the minute radicle, the stipes diverging almost

horizontally, or rectangularly to the radicle.

“© 9, A young specimen with one stipe entire, and a part of the other, less diverg-
ing than fig. 1.

“© 3. A single imperfect stipe of a young or half-grown individual, which is nar-
rower than usual.

“ 4, A larger stipe, which is entire from the base to the apex.

“5. A large or full-grown single stipe, which is nearly entire.

6, Anenlargement to three diameters from fig. 4, showing the form and propor-
tion of the cellules, and cell-denticles.

«© 4, An enlargement to the same degree as the preceding, from fig. 5.

“© g, A young specimen where the stipes are twisted near the base, giving an appear-
ance as if the serrations were on the outer or lower side in relation to the
direction of the radicle.

GRAPTOLITHUS BIFIDUS, page 73.
Fig. 9. An individual from the river St. Anne, showing a greater divergence of the
stipes, which are wider than those from Point Lévis. (See plate i.)
« 10, An enlargement from one of the stipes of the preceding, showing the form
of serratures, and the minute pustules at the base of the cell-divisions.

GRAPTOLITHUS BRYONOIDES, page 84.

Fig. 11. A fragment of a stipe from the rough shales containing Phyllograptus ilicifolius.
In the character of the cell-denticles it resembles the specimen pl. iv, fig. 9
and with that one may constitute a distinct species.

« 12, An enlargement of a part of the specimen fig. 11.

Geological Survey of Canada.

Sir WE. Logan, Divecter.
Decade 2. : ay ieee ae Plate 3 |
Suseuehr e. Quebec Group.

Lower Siluzian.

RR. P Whitfield.Delt James Hall, Deserp+* James Wuthie,Se. .

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EXPLANATIONS OF PLATE IY.
GRAPTOLITHUS BRYONOIDES, page 84.

Figs. 1, 2, 3. Young individuals of this species.

4, An older individual.

“© 5, A young specimen preserving two of the stipes, the funicle having been broken.

6. An enlargement from fig. 1, showing the radicle, funicle, and origin of the
four stipes, with a few of the earlier cellules.
. An older and larger specimen.
. An enlargement from fig. 7 showing the character and proportions of the
cellules.

9, A small individual, preserving the four stipes in part, which are somewhat
more slender than the usual forms of this species.

“ 10. An enlargement of the base of the specimen, showing the cell-denticles on
one of the stipes, and a proportionally longer funicle than in fig. 8.

« 11, An extremely elongated stipe, the lower end showing the commencement of
growth; the distal extremity is broken.

oO -T

«*, Figs. 9 and 10 may possibly prove to be distinct species. (See pl. iii, figs. 11, 12.)

GRAPTOLITHUS DENTICULATUS, page 88.

Fig. 12. A small imperfect specimen, preserving three of the stipes.

«© 13, A larger and more nearly entire specimen, showing the four stipes. Their junc-
tion at the base is not quite satisfactorily shown.

“© 14, A part of a single stipe, in which the cellules are well shown on one part;
while they are compressed and nearly obliterated on the left of the curve.

© 15, An impression of a part of a stipe which is nearly straight; the imprint of
the axis or thickened margin is not defined.

“© 16, An enlargement from figure 14, showing the form of the cell-denticles, and
the strong marginal axes; one portion represented with the substance
remaining, and the other as an imprint.

Geologterl Suevey of Canada.

Sir W. &.. Logan, Director. :
Say sat abate b hea 17 W, By L Oxe I C L Pike ma
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EXPLANATIONS OF PLATE V.

GRAPTOLITHUS QUADRIBRACHIATUS, page 91.

. A large specimen with stipes vertically compressed.
. A young specimen in which one of the stipes appears to be subdivided.
. An individual with stipes a little curved, the back of the stipe visible, and

showing no serratures.

. A frond with one of the stipes broken off; one showing the cellules and dis-

tinct strie parallel to the cell-partitions, while the other two are turned so
as to obscure the cellules.

. An enlargement from fig. 1: the stipe has been vertically compressed, causing

the cellules to show a less angle with the stipe than in the normal condition.

GRAPTOLITHUS FRUTICOSUS, page 90.

. A small individual with the extremities of the radicle and stipes broken off.
. An enlargement from fig. 6. The serratures are either imperfect or shrunken,

and do not present the characters seen in better-preserved specimens.

. An individual nearly entire, with an extremely long and slender radicle, but

imperfectly preserved in the outline of its parts.

GRAPTOLITHUS PENNATULUS, page 82.

Fig. 9. Asingle stipe of this species? The specimen isa large stipe, somewhat obscurely

preserved upon the surface of a slab of slate, with G. extensus, G. bryon-
oides, and Phyllograptus ilicifolius. It is from the same locality with
G. bifidus at Point Lévis. In the form of the stipe, and its gradual diminu-
tion towards the distal extremity, as well as in the absence of visible pus-
tules at the base of the cellules, it has the habit of G. pennatulus. Being
the only individual observed from this locality, and the resemblance to
G. bifidus being very close, I have referred it with much hesitation to
G. pennatulus.

GRAPTOLITHUS CRUCIFER, page 92.

Fig. 10. View of the specimen from which the description is drawn.

“ce

13. The dise of a young individual probably of this species.

GraprTouitHus Hzapi(?) page 94.

Figs. 11 and 12. The central discs of two individuals which may belong to G. Headi.

Sk ee Ed ‘y bt

- Geologteal Survey of Canada,
Sir W. EF. Logan Director.

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Fig. 5.

Fig. 7.

Fig. 8.

Fig. 9.

EXPLANATIONS OF PLATE VI.
GRAPTOLITHUS FRUTICOSUS, page 90.

A fragment showing two of the stipes entire, and the bases of two others; the
radicle extending to the margin of the specimen.

. Aspecimen preserving three of the stipes, one of them entire, and showing

some irregularities in the bifurcation where the one is broken off.

. An enlargement of the right-hand stipe of the specimen fig. 1.

GRAPTOLITHUS BRYONOIDES, page 84.
A frond in which three of the stipes, and the base of the fourth, are preserved.

The specimen shows some peculiarity in the union of the parts by the
slender funicle. From the river Ste. Anne.

GRAPTOLITHUS QUADRIBRACHIATUS, page 91.

A frond preserving one stipe partially entire, and others broken off: the funicle
and radicle-point are well preserved.

. An enlargement from the specimen fig. 5, showing the form and proportions of

cellules in their more perfect preservation, with the striz parallel to the cell-
margins well preserved.

GRAPTOLITHUS CRUCIFER? page 92.

A central dise of G. crucifer, with the bases of the branches.

Graprotiraus Hwan, page 94.

A representation of the specimen of the natural size, and as it occurs on the
surface of the stone. (The upper separated portion of the stipe is placed
a little lower in the figure than it is on the stone, in order to bring it
within the dimensions of the plate.)

GRAPTOLITHUS ALATUS, page 93.

The specimen represented as it occurs on a fragment of slate. The back of the
stipes shows faint indentations, but they are made too strong in the
engraving.

Geological Survey of Canada.

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EXPLANATIONS OF PLATE VII.
GRAPTOLITHUS OCTOBRACHIATUS, page 96.

A large individual preserving two of the stipes to the length of eight inches, and
another to nearly the same extent, while the rest are broken off at less
distances from the disc. The flexibility of their substance is well shown in
the recurved stipe at the left-hand side of the figures. Although this speci-
men preserves the most extended stipes of any in the collection, the disc
is smaller than in several of the other specimens.

. The exterior ofa large disc of this species, with the stipes broken off a little

beyond its margin. The two longer portions are so turned as to show the
cellules.

. A portion of a large disc, showing the exterior or non-celluliferous face of the

frond, and preserving portions of four of the stipes.

. A frond with the stipes broken off at different distances from the centre. The

substance of the disc or cup is imperfect,—a condition which apparently
existed while the body was in a living state.

. An enlargement from one of the stipes of fig. 1, at c, looking upon the apertures

of the cellules, which are somewhat compressed.
An enlargement from the same at b, where the substance is laterally compressed.
An enlargement from the same, where the substance is obliquely compressed at a.

Figs. 5 and 7 are taken from casts made in the impressions left by removal of the
substance of the graptolite.

Decate Z.
Lower Silurian.

Geological Survey ot Canada,
Sir W, E.. Logan, Director
‘ Grap tolitide,

© BE, Whithela Del

James Duthie

4
EXPLANATIONS OF PLATE VIII.

GRAPTOLITHUS OCTOBRACHIATUS, page 96.

Fig. 1. A symmetrical frond preserving parts of all the stipes, two of them apparently
almost entire ; several of them had been abruptly bent before being im-
bedded in the stone.

2. A frond preserving eight stipes, but without a disc. The specimen does not afford
any evidence that a disc has ever existed.
“ 3. A frond with small disc and somewhat slender stipes. One side preserves the
usual character of four stipes, while the other has but three.
“ 4, A frond which is abnormally developed ; one side exhibiting the four stipes with
the disc, while on the other side the funicle is apparently extended in a single
stipe only.

GOeologwal Survey ot Canada,

; Sir W, E.Loéan, Director .
Decade 7. . ee fate 8.
Graptolitide.

Lower Silurian. Quebec Group.

: all
B.P. Whitfied Delt James Hall, Descrp James Duthie,Sc.

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EXPLANATIONS OF PLATE IX.

GrapToLitaus Logani, page 100.

Fig. 1. A specimen of slate, preserving portions of three individuals (two only given

“
a“

in the illustration). The disc had probably been removed by maceration
before they were imbedded, but the stipes are preserved to a length of
more than seven inches. It does not appear that this exhibits the entire
skeleton : the stipes were originally longer. The serrated margins are not
always shown at equal distances from the centre; but this is due to acci-
dental position, some stipes showing the exterior surface for some distance,
and then gradually turning and becoming flattened laterally.

. A specimen showing the disc almost entire.
. An individual showing the exterior surface the central portions entire, with the

impression of the connecting disc, some portions of which remain attached
to the stipes. The extent and outline of the disc are distinctly seen.
The appearance of serratures is due to exfoliation, which shows the impres-
sion of the celluliferous side of the stipe upon the stone.

. A specimen exhibiting the half of an individual, with the disc unequally ex-

tended between the rays. The margins are all apparently entire, and this
inequality, to whatever accident due, existed in the living animal.

. Exterior view of an individual showing some remaining portions of the disc; the

stipes are all broken off beyond the bifurcations.

- Another individual showing the inner side, with the commencement of the cells,

which appear in some places in double series. The substance of the dise
is removed.

. Enlargement of the exterior surface of the central portion of the specimen fig. 5.
. Enlargement of the inner surface of the specimen fig. 6, giving the appearance

of a double series of cells separated by a depressed line in the substance of
the stipe. Sometimes this separation appears to be actual, while else-
where the apparent division is due to the depression along the centre.

. Enlargement of a fragment of a stipe, showing the form and proportions of

the cellules.

Grologteal Surven of Canada,

Sir W. E. Logan. Director.

cade 2 Graptolitids

—

a _ ” Famne Dushie Se.

EXPLANATIONS OF PLATE X.
GRAPTOLITHUS OCTONARIUS, page 95.

Fig. 1. A specimen of natural size, much broken and distorted from pressure.
‘“¢ 2. An enlargement from the preceding figure.

GRAPTOLITHUS FLEXILIS, page 103.

Fig. 3. A fragment of slate preserving more than half of a frond, and showing the
folding and crossing of some of the branches.
“« 4, A fragment preserving parts of three individuals, the extremities of the branches
all broken off.
“ 5. The central portion of the frond of another individual.

. Separated branches preserving the cellules in unusual perfection.

“ 7. An enlargement of the centre of the frond, fig. 5, showing the short radicle
and the usual mode of branching. The central part of the axis is rounded,
with a narrow corneous alation at the sides.

“ 8. A bifurcated fragment enlarged, from fig. 4: the cellules have been flattened
vertically, causing them to be visible in slight indentations on both sides of
the axis.

9. A portion of a branchlet enlarged from fig. 6, showing one part compressed
laterally, with the cellules fully expanded, while the other, on the right
hand, is gradually twisted so as to show only the back of the branchlet.

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Fig. 7.

EXPLANATIONS OF PLATE XI.

GRAPTOLITHUS RIGIDUS, page 105.

. A fragment preserving the centre and principal branches.
. A larger specimen, showing the principal ramifications of the branches. This

and the preceding specimen show only what appears to be the non-cellu-
liferous portion of the frond.

. The extreme parts of some branchlets laterally compressed, showing the cellu-

liferous parts of the frond.

. An enlargement of one of the branchlets of fig. 3.
. A strong branch with part of the branchlets, showing the lower side or non-

celluliferous portion of the frond.

GRAPTOLITHUS ABNORMIS, page 106.

. A fragment of slate preserving the centre and the branches on one side to

beyond the first bifurcation. The other side is imperfect, and apparently
less developed.

GraprTouitaus Loeant, page 100.

The central part of an individual without disc, showing five stipes on one side
and four on the other. This is supposed to be an abnormal form of G,
Logani.

Director

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EXPLANATIONS OF PLATE XII.

GRAPTOLITHUS RICHARDSONI, page 107.

. A fragment of slate, preserving a stipe, with six branches in its apparent con-
tinuation, and impressions of two others in the intermediate space ; two of
these again bifurcating.

. A fragment preserving several branchlets, which are compressed in different
directions, showing the sides and apertures of the cellules.

. An impression of a bifurcating fragment, the cellules of which were filled with
mineral matter and vertically compressed.

4, A fragment of a branch laterally compressed.

. The impression of a bifurcating branch where the cellules are somewhat
obliquely compressed, and partially filled with mineral matter.

6. A fragment enlarged, giving a lateral view of the cellules.
7. An enlargement from an impression of a branchlet, from fig. 5, which is

obliquely compressed, having the cellules filled with mineral matter.
. Enlargement of a fragment, from fig. 1, where the cellules are filled with min-
eral matter and vertically compressed.

GRAPTOLITHUS RAMULUS, page 108.

9. A small bifurcating branch.

10. An enlargement of fig. 9, showing the form and extent of the cellules.

Geologterl Survey of Canada.

Sir W. E..Logan,Director.

Decade 2:
Lower Stluzian.

Graptolitida

A. P, Whitheld Delt James Hall,Deserpt

Jamies Duthie, Se.

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EXPLANATIONS OF PLATE XIII.

GRAPTOLITHUS QUADRIMUCRONATUS, page 144.

Fig. 1. Part of a stipe compressed in a slightly oblique direction, still showing the
cellules on the two sides.

2. A stipe compressed more obliquely, so as nearly to obscure the cellules on
one side.

3. A specimen compressed vertically to the celluliferous side of the stipe.

4,5, and 6. Enlargements from specimens, figs. 1, 2, and 3 respectively.

7. Enlargement from a specimen where the solid axis lies near to one side.

8. A specimen obliquely compressed, so that the mucronate points at one angle
of the cellules of the left side, are pressed through the test, and show on

the surface as a range of pustules. The axis is displaced, and seen on one
side of the centre.

9. A diagram representing a theoretical longitudinal section.

10. A transverse section of a stipe with the mucronate extensions of the cell-
margins.

(73

“

CLIMACOGRAPTUS ANTENNARIUS, page 112.

Fig. 11. A young individual, compressed in such a manner that the cell-apertures are
not shown upon the margin.

12. A flattened stipe, presenting only the mucronate terminations of the cell-
apertures beyond the margin.

13. An older individual, showing the margins of the stipe extending beyond the

cell-apertures, while the cellules are visible in the substance of the stipes
as darker areas.

DIPLOGRAPTUS INUTILIS, page 111.

Fig. 14. A piece of slate preserving fragments of two individuals.

DIPLOGRAPTUS PRISTINIFORMIS, page 110.

Fig. 15. A fragment of a stipe, showing the usual form and proportions of the best-
preserved specimens.

16. A smaller individual, with the mid-rib or axis extending beyond the body of
the stipe.

17. An enlargement from fig. 16, showing more distinctly the form of the cellules.

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EXPLANATIONS OF PLATE XIV.

RETIOLITES ENSIFORMIS, page 114.

Figs. 1, 2, 3. Individuals showing gradations in growth, and slight differences in their
proportions.

4. A nearly entire stipe of the largest size observed.
5. An enlargement from the specimen fig. 2.

a
“ce

RETIOGRAPTUS TENTACULATUS, page 116.

Fig. 6. An individual of the natural size, with the marginal reticulations nearly entire.
“ 7, The preceding specimen enlarged.

8. An enlargement of another individual, where the marginal reticulations are
but partially preserved.

ce

RETIOGRAPTUS EUCHARIS, page 146.

Fig. 9. An illustration of a compound form of the genus, enlarged to four diameters.

Decade 2.

Lower Silurian .

(Ib ci

Logierl Suemey of Canad.
“Sit W. Bi. Logan, Director.

Graptolitide:.

Plate 14

Quebec Group.

Wi

FUP. Whitfield Delt

James Hall, Descrp ©

James Tuthie,Sc

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EXPLANATIONS OF PLATE XV.

PHYLLOGRAPTUS TYPUS, page 119.

An extremely short and broad form of this species, with the axis broad, and
showing some remains of the cellules at the base of the separated division.

An elongate-ovate form of stipe, with a broad axis, which does not show
remains of cellules. Some of the cellules in the upper part of the stipe are
filled with iron pyrites.

. A form similar to the preceding, showing remains of cellules on the upper

part of the axis.

. An elliptical form of stipe, where two of the divisions have been separated

leaving the bases of two sets of cellules.

. A broadly elliptical form, from which two of the divisions and the axis have

been removed; showing the bases of the cellules of the folia which remain
in the slate.

. A stipe compressed in the same direction as fig. 3 of the generic illustrations

page 119; with a part of one of the folia removed, but not reaching to the
axis. The lines of the cell-partitions appear as if continued across the
axis.

. An elongate-lanceolate form of stipe, which does not show cellules in the

line of the axis.

. An elongate-elliptical and very symmetrical specimen, showing the marks of

cellules along the axis, which is unusually narrow.

. A part of a stipe folded in the manner of fig. 6, the upper portion of one side

preserving only the impression of the substance. In the lower part, the
cell-markings on the axis should be shown more distinctly.

. A group of small stipes upon the surface of a piece of shale. These are given

in their natural size and in their actual relations to each other.

. An enlargement of a part of an impression of a stipe which has been flattened

in the direction of figs. 6 and 9. A portion of the substance remains, as
shown on the left hand; the cellules filled with iron pyrites.

An enlarged portion from a stipe, showing the double cell-denticles and
corresponding cell-partitions. The narrow spaces on the surface of the
figure are more elevated than the wider ones, with a greater thickness
of the substance; which I suppose may have been caused by the cell-
partitions, which are obliquely compressed, thus showing the cell-denticles.
These elevated spaces become gradually narrower towards the axis, in
accordance with the form of the cells, as shown in the theoretical figure 10
plate xvi.

©

Fi, Logan, Director:

Sun: WwW,

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Decade 2.
Lower Silirian.

Quebee Group,

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EXPLANATIONS OF PLATE XVI.

e
PHYLLOGRAPTUS ILICIFOLIUS, page 121.

Fig. 1. An individual of the natural size, where the folia 6, a* are broken entirely

away beyond the axis, leaving the bases of the cellules of two adjacent
folia visible, except at the upper part of the figure, where two or three of
the bases of the other cellules remain.

2. A similar specimen, showing the bases of a set of cellules on each side of the

centre, with two or three of those belonging to the broken folium at the
base of the figure. ;

“ 3. An enlargement of fig. 2, showing more distinctly the cellules on each side

£4

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ef the central line, and the small remaining portion at the base.

4, A specimen of the natural size, where one folium is broken away not quite

so far as the axis, leaving the bases of its cellules visible.

5. An enlarged figure from a specimen which has been imbedded transversely.

Three of the divisions have been broken away, leaving impressions of the
lateral ones only, and of the cell-bases and cell-partitions of the fourth
division, which are directed obliquely upwards from the axis and point of
view. The lower part of the specimen preserves a portion of the lateral
folia, with the bases of the cells of the outer division a*, which are directed
towards the axis.

6. An enlargement of a specimen which is imbedded obliquely, or in a direc-

tion as if the theoretical figure 10 were vertically compressed, leaving
no visible axis. In the lower half of the specimen, the fossil has been
separated in the opposite slaty laminz, leaving only the impression of that
side, which also shows no axis. In the upper half of the specimen, the cel-
lules are well preserved, and on the left-hand side the apertures are con-
spicuous. Enlarged to three diameters.

It will be observed that the impression is not quite in the same direction

as the outline in the upper portion of the figure, owing to the obliquely-
compressed folia.

7. A specimen compressed in the same manner as fig. 6; the upper folia have

however been separated, except the bases of a few of the cellules in the
upper part of the figure, leaving the other two folia imbedded in the shale,
and showing the bases of their cellules ascending from the axis. Enlarged
to three diameters, as in fig. 6.

8. An enlarged figure of a specimen compressed in the direction first described,

without any separation of the parts; from which cause there is no proper
axis visible. In this condition, thespecimens resemble Graptolithus folium
of Hisinger, or G. ovatus of Barrande.

9. An enlargement of a specimen compressed as in fig. 8, but with the cellules

filled, and the margins of the upper two folia broken, showing the cell-
openings. (8 and 9 are enlarged to twice their natural size.)

10. A restoration of the form of P. ilicifolius, showing the four divisions ; which

are represented as cut through transversely, exhibiting the cell-cavities.

* These letters refer to the illustrative figures, page 119.

EXPLANATIONS OF PLATE XVI, continued.

PuyLiograPtTus ANNA, page 124.

Fig. 11. A specimen with the folia obliquely compressed.

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12, 13, 14. Individuals showing some varieties of form. The specimens have all
been so imbedded that one of the folia has been torn away in the separated
lamine of shale, leaving an axis marked by the bases of its cellules.

15. An enlargement of a specimen which has one of the lamin vertically im-
bedded, and shows the bases of the cells as they recede from the axis. The
markings at the sides are from the impressions of the folia, except a small
fragment of one remaining on the left-hand side of the figure.

16. An enlargement from a specimen where the two lateral folia remain, showing
the bases of the cells of the folium which has been broken off, in the
separated lamine of slate. The surface is distinctly striated.

PHYLLOGRAPTUS ANGUSTIFOLIUS, page 125.

Fig. 17. A small and comparatively wide specimen, with a distinct linear axis, but

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without evidence of cellules.
18. A more elongate specimen, with distinct axis, with a darker line in the centre.
19, 20, 21. Varieties of form and proportion. The specimen fig. 21 is the largest
observed.

This species is placed under Phyllograptus from its similarity in form to
others of the genus, although evidence of the quadruple division has not
been established. The want of parallelism of the margins, and the sub-
elliptical form would, I conceive, be sufficient to remove it from the genus
Diplograptus.

GRAPTOLITHUS BiesByI, page 86.

Figs. 22, 23, and 24 illustrate a common condition of this species, where two of the

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divisions show the lateral faces, while the non-celluliferous edge of a
third division is seen lying nearly vertically in relation to these. The
fourth division has been broken off in the separated film of slate.

25. A specimen showing the lateral faces of two divisions. Below these, in the
shale, are seen the non-celluliferous edges of the two other divisions.

29 and 30 show a still closer arrangement of the parts, and the contiguity of
the non-celluliferous edges at the apices, which are scarcely perceptibly
separated in the shale.

26. An individual where the apices of the divisions are in contact, either conjoined,
or accidentally so placed, with a narrow space in the centre. In obscure
specimens it is difficult to separate such forms from Phyllograptus.

27. An individual where the divisions are equally spreading: one of them pre-
serving only the base of the stipe.

28. The same enlarged.

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EXPLANATIONS OF PLATE XVII,

DENDROGRAPTUS FLEXUOSUS, page 127.

Fig. 1. A small frond of the natural size.
2. A part of a larger frond.

DENDROGRAPTUS DIVERGENS, page 129.

Figs. 3, 4. A specimen of natural size, and an enlargement of the same.

DENDROGRAPTUS STRIATUS, page 129.

Fig. 5. A fragment of a frond, preserving the bases of some of the branches.
“ 6. A portion of the non-celluliferous surface enlarged.

DENDROGRAPTUS ERECTUS, page 130.

Fig. 7. The principal stipe, and bases of some of the branches, of the natural size.

DENDROGRAPTUS FRUTICOSUS, page 131.

Fig. 8. A frond which is apparently nearly entire.
«“ 9. A more diffuse form of the same species, with some of the branches broken off.

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EXPLANATIONS OF PLATE XVIII.

DENDROGRAPTUS? (CALLOGRAPTUS ?) DIFFUSUS, page 132.

Fig. 1. A portion of a broken frond from near the base. The test is removed in some
parts, showing celluliferous markings.
2. A fragment of another specimen with similar cell-markings.
“ 3. An enlargement, showing the cell-apertures. The specimens are extremely
compressed.

CALLOGRAPTUS ELEGANS, page 134.
Fig. 4. A fragment which is more lax and spreading, with shorter branchlets

than the ordinary specimens, but having similar strie, and a similar arrange-
ment of cellules.

DENDROGRAPTUS GRACILIS, page 132.

Fig. 5. Two of the larger branches with their sub-divisions, of the natural size.
‘ 6. An enlargement from one of the branchlets, showing the striate surface and
the deep indentation of the cellules.

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EXPLANATIONS OF PLATE XIX.

CALLOGRAPTUS ELEGANS, page 134.

Fig. 1. A fragment of a frond, natural size.

«2. A nearly entire fiabelliform frond. The two shaded lines running nearly ver-
tically through the figure, are due to faults or slips in the slate, causing a
slight overlapping of the laminugw, and an interruption of the continuity of
the frond.

“ 3. An enlargement, showing the lateral connection of the branches at irregular
intervals.

“ 4, A further enlargement of the non-celluliferous side of a bifurcating branchlet,
showing the striated surface and a semi-articulate structure.

CaLLograptus SALTERI, page 135.

Figs. 5, 6. Fragments of two distinct fronds; one showing the celluliferous side, and
the other the non-celluliferous side.

“ 4, An enlargement from the non-celluliferous side, showing a few transverse dis-
sepiments at irregular intervals. The figure has the same degree of
enlargement as fig. 3 of C. elegans.

“ 8. A farther enlargement of a bifurcating branchlet, showing the cell-apertures.

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EXPLANATIONS OF PLATE XxX.
DICTYONEMA IRREGULARIS, page 136.

Fig. 1. A fragment from near the base of a frond.
“ 2. A fragment from the outer portion of the frond.

DICTYONEMA ROBUSTA, page 137.

Figs. 3, 4. Fragments of two different fronds. In some parts of the specimen fig. 3, and
in all of fig. 4, the branches are extremely flattened and attenuate.

DICTYONEMA QUADRANGULARIS, page 138.

Fig. 5. A fragment of a frond, of the natural size.

DicryonemA Murrayi, page 138.

Figs. 6, 7. Fragments of two fronds ; the figures of the natural size.

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EXPLANATIONS OF PLATE XXI.

PTILOGRAPTUS PLUMOSUS, page 140.

Fig. 1. A fragment which is three times branched.

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3. An enlargement from the specimen fig. 1.
4.

A further enlargement of a portion of the same; some of the branches showing
markings like cell-apertures.

PTILOGRAPTUS GEINITZIANUS, page 140.

A branching fragment showing the celluliferous side.

. A fragment which is irregularly branched, showing the non-celluliferous side.
. A single branchlet of the same species.
. An enlargement from fig. 5, showing the cell-apertures.

THAMNOGRAPTUS ANNA, page 141.

A fragment of the species, of the natural size.

Geologtaxl Surven ot Canada,

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