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[From the Quarirrly Journal of the Geological SociEiir/oi- ^-^

Fehruarij 1879.] j

Oil a NEW Species of Loftusia from British Columbia. By
George M. Dawson, D.8., Assoc.ll.S.M., F.G.S., of the Geo-
logical Survey of Canada.

[Plate VL]

L\ 18G9, Dr. W. B. Carpenter and Mr. H. B. Brady described, iu the
'Transactions ' of the lloyol Society, two remarkable types of gigantic
arenaceous Foraminifera, under the generic names of ParJceria and
Loftusia. For the description of the latter form Mr. Brady is more
particularly responsible, and tot!-.. ;?enus then created by him I have
now to add another species, for which the name of Loftusia Colum-
biana is proposed.

The original specimens of Loftusia were obtained many years ago
by Mr. W. K. Loftus in Persia. They were referred to in "his paper
on the geology of the Turco-Persian frontier and districts adjoining,
published in the Quarterly Journal of the Geological Society in 1855,
but remain w'd undescribed till they came into Mr. Brady's hands.
From the geological descriptions by Mr. Loftus, and other forms of
Foraminifera found in the same stones, Mr. Brady believes the geo-
logical position of Loftusia persica to be in the oldest Tertiary rocks.
The specimens now to be described are from the interior of British
Columbia, and their ago is, I believe, Carboniferous. Examples of
the form were first collected by Mr. J. llichardson, of the Geological
Survey of Canada, in 1871, and are mentioned in the Eeport of
Progress for 1871-72. About a year ago, I examined Mr. Ilichard-
son's specimens with some care ; but during the past summer, having
opportunity to visit the locality from which they were procured, the
occasion was taken to collect a large number of additional specimens,
representing all varieties of appearance and preservation. Mr.
Thomas C. Weston has prepared from these and JMr. Richardson's
specimens a number of transparent sections, from which the accom-
panying descriptions and drawings have been made.

Most of the specimens are from Marble Caiion, a remarkable valley
which runs through from the banks of the Fraser Eiver to the bend
of Hat Creek, with a direction nearly transverse to that of the main
features of the country. For a distance over ten miles, the sides of
the vaUey are formed almost continuously of mountains of limestone
or marble. The first impression is that an immense thickness of
limestone is represented in the exposures; but, although the dips are too
obscure to allow the attitude of the beds to be worked out throughout
the length of the Canon, some small sections show that part at least
of the beds have been sharply folded and the whole series of folds
overturned. This being the case, it may be that a comparatively
thin limestone or series of limestones forming a succession of folds
superimposed on a broad anticlinal flexure account for the appear-
ance presented. That the limestones have a very considerable thick-

<U a. ii. DAWSON OS A Ni;\v 8i'i;cii;s uv

iiess, however, wouiil appear from the fact that about soventoon
miles to the north-west they are seen forming a range of mountains,
which rise to altitudes of over loUO feet al)ovc the level of the neigh-
bouring valleys, and run I'lom near Kelly's Lake to Canoe Creek,
The (.'lysical rehilions of the beds will, iiowever, bo described at
greater lengtli in the next ]{eport of the Geological Survey.

Though inclined to correlate tliese limestone beds, on stratigra-
phical and lithological evidence, with otliers from Avliich Carbonife-
rous forms have been ol)tained, no fossils more chariictcristic than
the joints of Crinoidal columns were for some time found iu associ-
ation Avith tlie Foraminil'er now desciibed. After some search, how-
ever, specimens of FKfii'liud were discovered, tlius 1)ringing these
into relation with the /<'»*'«///( a-bearing limestones found elsewhere
in the province, and also very widely over the western part of the
North-American continent .

^[any loose fragments and boulders of Loftasid-Vimvutonc were
also found at " The I'ouutain," on the surface of a high terrace, there
overlooking the Fraser, This place is about nine miles south-
westward from the nearest of the ilarble-Canon ex]>osures ; and the
specimens here may have been derived from a distinct outcrop not yet
discovered.

In certain beds of tho limestones of ^larble Caiiion, the Loftiisiu
occurs almost to the exclusion of other forms, characterizing the
rock, and having been the agent in its production, just as Fufiulin<v.
occur in the best examples of Fasidiua-Wmc^ionc or QlohUjcrinoi in
tho Atlantic ooze. Other beds of a nearly white colour and almos^t
])orcellanous aspect on fracture— though purely calcareous— are
found on mierosco])ic examination to consist of the comminuted re-
mains of smtdler Foraminifcra, the mass resembling a thoroughly
Imrdened chalk. Through these a few more or less perfect Loftus'uK
may be scattered. FusuluHe appear to be very scarce in the Marble-
Caiion limestones ; they are much more abundant in those of other
parts of the country, composed principally of Crinoidal fragments.
They seem to have pi'cferred a bottom composed of the debris of tho
larger calcareous organisms to the fine oozy bed most congenial to
the Loftusid.

The typical and most abuncttait form of Zq/V^Mrt-limestono is a
pale or dark grey cryptocrystalline rock, in which tho more perfect
specimens of Loftasia appear thickly crowded together as paler spots,
generally pretty shar])ly defined. The limestone breaks freely in any
direction, the fiacture passing equally through the matrix and in-
cluded organisms, which it is impossible to separate from the stone.
Tho matrix generally seems to be composed in great part of granular
calcareous matter similar to that employed iu building i p the test
of the Loftusia, but more irregular in size of grain, and with an oc-
casional fragment of a Crinoid or example of some smaller Fora-
minifer. When a F((sidina is found, even on the same thin section
with a Lofhisia, it dift'ers totally from the latter in appearance. Tho
fine tabulation of the walls has not been preserved ; but the calcite
is homogeneous and almost milky in appearance, while tho frag-

LCfTUSIA FROM DRIIISH COLUMBIA. 71

mental character of the test of Loftmia is apparent even unde • a
low power, and it has a peculiar sparkling as]tect.

In form, the species bears a close resemblance to L. pcrsica, espe-
cially to the stouter variety represented in plate Ixxvii. fig. 3
of iiossi-8. Carpenter and lirady's memoir. I have not observed any
specimens to assume a form quite so mitch elongated in proportion
to the breadth as that given in figure 3 of the same plate. It is a
regular oval, with circular cross section, the ends varying from ob-
tusely rounded to bluntly spindle-shaped. The Marble-Canon form,
however, is very much smaller than L. persica, both in its external
dimensions and proportiv;nally in all its structures. By measure-
ment of a number of specimens, the average length of the shorter
axis appears to be from 10 to 20 hundredths of an inch, that of tho
longer axis about 30 hundredths ; one specimen measuring as much
as ^y^- in its lesser diameter has been found. Some may attain a
lengtli of y'mj or even j^^~ of an inch ; a remarkably long and nar-
no-w exiimplo measured j^'j of an inch by yt,'^t o*: ^'i inch. I have
not been able to observe any regular furrowing of the outer surface
of the test, though from the appearance in cross sections, it is pro-
bable that a tendency to such marking exists in some specimens.
Others must have l)ecome more or less rough and irregular in form,
from the acervuline mode of growth fre(|uently assumed in the larger
examples. !Maiiy specimens are, like those of the Persian form, more
or less oval or elliptical in the outline of tho cross section. As, how-
ever, in some specimens many exam])les may be found in different
stages of degradation towards absolute shapelessness, I believe, as
Sir. Brady does of the Persian form*, that this is abnormal, and the
result of changes after the dcatli of the animal. In some cases, spe-
cimens of irregular form are scattered among others of normal ap-
peal nee, and seem to have decayed or collapsed more or less com-
pletL _, before the consolidation of the sediment, in otlier layers,
the -whole rock has very evidently been compressed during metamor-
phism, all the Eoraminifera being flattened parallel to one plane.

The structure of this form is in most respects strikingly similar
to that of Lnffii.tia prrsica, and, like it, extremely complicated. With-
out Mr. Brady's elaborate and lucid description of tho former, it
would have been a matter of no small difficulty to make out tlie plan
of growth of this smaller species, which it is possible to examine in
thin sections only.

In describing the structure, tho same terms made use of in the
memoir already severnl times referred to will be employed. I would
also call attention to the diagrammatic representation of the plan of
the test of Loftn.sid on page 743 of the memoir.

No central primordl.il chamber, or se^-ics of chambers, like that of
Parheria has been found. The nucleus of the test appears to be, as
in L. perska., a loose-textured granulated mass, nearly circular in
cross section. It has not been observed, however, to become so di-
stinctly cancellated as appears to be the case in L, persica.

In theory, this test may be said to consist, like that of tho original

* Op. cif. p. 742,

72 0. M. DAWSON OS A NEW SPECIES OF

spocios, " primarily of a continuous lamina coilod upon itself, like a
scroll coustrictcd at the ends. The space enclosed by this ' primary
lamina ' is divided into chambers by longiludinal septa. The septa
are of ' secondary ' growth ; that is to say, they are not continuous
with the principal wall or ' spiral lamina,' but are rather otfshoots
from it"*. As seen in a transverse section of the test, these septa
are not perpendicular to the spiral lamina, but very oblique to it ; and
on further examination they are found to lie nearly parallel to the
surfaces of a supposed second scroll, concentric with the first, but
not, like it, constricted at the ends. Tlie lines of intersection of the
" secondary " septa and " jjrimary "' lamina make, therefore, curved
or oblicjue outlines on the surfaces of the latter. The 8e|)ta sliow,
however, as straight or nearly straight lines in longitudinal and tan-
gential sections.

A series of " tertiary " ingrowths further pass between the opposed
surfaces of the " i^rimary " lamina and those and the "secondary"
septa. These processes are in the form of pillars, and are arranged
in rows, longitudinally and transversely, appearing most regidar
in a longitudinal section. They are at right angles, or nearly so,
to the "primary" lamina. The structure is further complicated by
the fact that the " tertiary " columns, where they attach tliemselves
to the spiral lamina; at their distal extremities, expand into a more
or less regular cross-shaped form, the arms of whicli, uniting with
those from the neighbouring pillars, form a reticulated framework.
This, owing to the regularity of position of the columns, may almost
be considered as forming a system of crossed rafters supporting the
" roof " of the space contained between each two consecutive folds of
the " primary ' " lamina, while the columns do not show any such ex-
pansion on the " floor." The spaces between the expansions or
rafters, constituting a series of imperfect chambers, are further tilled
with a loose cancellated growth, which sometimes depends more than
halfway to the " floor." This represents the system of " irregular
anastomosing tubes " and " parallel columnar or tubular processes "
occupying a like position in L. pcrsica ; but in the form now under
consideration, probably owing to the greater size of the calcareous
particles in proportion to that of the test, and its consequent rougher
construction, no distinct tubulation is recognizable.

The greatest number of convolutions of the " primary " lamina
actually observed is seventeen. Ten is a very common number in
average-sized specimens. The average breadth of the space enclosed
between two successive convolutions of the lamina is one hundredth
of an inch ; and this is maintained with considerable regularity,
though in young specimens the first two or three whorls are much
less. The " tertiary " processes or pillars, and the bars of the reti-
culated framework connected with them, are generally in diameter
from one four-hundredth t(> one three-hundredth of an iuch, very
rarely as much as one hundredth.

The " primary " lamina, as in L. perslca, is a thin and definite
wall, generally appearing in microscopic sections as a well-defined,

# Op. cif. p. 743.

LOFTTJSIA FROM DRlTISn COLrMIlIA. 73

thou<i:h often somcwliiit flexuons dark lino. Tho "tertiary" in-
p;vowths, or juUars, are composed of comparatively larp^c ])!irtioles,
though these Hcarcoly ever attain a si^^c of one thousandth of an ineli.
Thouf^li rough in outline when examined under a high power, they
are well defined and compact-looking at their proximal extremities ;
where tlicy arc involved in the spongy growth from tlie roof, they
become less definite and occasionally ajjpear almost to vanish before
uniting with tlie lamina.

The expansions of the pillars against the roof, or rafters as they
have been called, are much deeper than m ide, and thougli definite
and clearly seen in tangential sections of tlie lamina, are generally
not distinguishable from the spongy ingrowth in transverse or lon-
gitudinal sections. ]}oth the rafters and cancellated ingrowth appear
to diher much in texture from, and to be much more transparent
than, tho columns. The secondary ingrowths, or septa, are of
similar material, and in many cases are scarcely to be distinguished
but for tho expansion of tlie pillars upon them.

Tho separation of tho primary lamina from the subsidiary
cancellated growth, said to be common in L. 'persim^ and re])re-
sented in plate Ixxix. fig. 2 {op. cit.), has not been observed in any
of these specimens, a circumstance probably in connexion witli
their smaller size and less complex structure. Many specimens show
externally a layer of variable thickness of acervulinO or irregular
groAvth. This appears to occur chiefly in those examples which
may bo supposed to have attained maturity, and to have fornnd a
stronger protecting crust round the delicate fabric of the tost, i'ig, 2
(PI. VI.) represents this feature, which does not appear to be found
in L. iHrslca. A layer of chambers without any definite external
lamina appears to bo formed, and these chambers communicate out-
ward, with still less regular openings, and degenerate eventually into
a cancellated or spongy mass of calcareous particles, which is gene-
rally limited by a firmer and darker outer layer. Smaller Forami-
nifera arc occasionally included in the substance of the test of the
Loftusia, though much larger than anv of the granular fragments
usually composing it.

In the matrix of some of the specimens are a few examples of a
form which, though seen onh* in transparent section, from its pre-
cise resemblance in size and shape to that figured by Mr. Brady as
Climacammeria antu/xa* in his memoir on Carboniferous and Per-
mian Foraminifera, I have no hesitation in referring to this species.

Mr. Brady says of the genus Loftusia that it would " seem to find
a natural place a^ the head of the Arenaceous series of Foraminifera,
a position corresponding to AlvcoJina in the Porcellanous group, and
FusuUna among the Vitreous forms." It is indeed remarkable to
find the Palaeozoic forerunner of the more gigantic Tertiary Loftusia
agreeing with it so preciselj^ even in many of the more minute points
of structure. The case is analogous to that of the discovery by Mr.
Brady in Carboniferous rocks of A^unimulina pristim, which in tho

Monogr. Palajontograpliicul Society, vol. xxx. p. G8, plate ii. fig. 8.

74 0. M. DAWSON ON A NEW 8ri;CIE9 OF

Bamo way corrospoiids very closely -with tho Tertiary and modern
Nuramiilitcs.

In the arranj?ciTiont of tho ])illars uniting,' tho folds of the lamina,
the sponj?y inp;rowtli fiUin*; the chamhers, and in otlier points, this
LoffiisiahciiTH a strikiiifij rescmhlanco to some forms of f^fromatijmm.
It differs, however, in its regnlarly spiral cliaraeter, and in the fact
that no pores have been observed to traverse tho "primary" lamina.
It is scarcely probable, however, that tho orj^anie connexion between
tho different parts of tho Loftima was maintained only in directions
parallel to tho circuitous course of the lamina.

Genus Lofiusia, Brady.

LOPTUSIA COLUXniANA, sp. uov.

Test oval ; circular in transverse section ; the ends rounded or
very obtusely spindlo-sha])cd ; cliambers man), narrow; septa very
oblique, more nearly parallel to tho sides of a cylinder tlian is the
primary lamina ; primary lamina and septa, or '• secondary " in-
fi;rowths, supported by pillars or '' tertiary " ingrowtlis ; j)illars nu-
merous, arranged in parallel linos transversely and longitudinally,
expanding laterally at their distal extremities to form imperfect cham-
bers, which are tilled with a loose, granular, cancellated growth.
Exterior of test frequently becoming irregular and acervuline.
Length of test about y-'j/Jy of an inch, width of test about y^yL of an
inch ; intervals between successive folds of tho adult primary lamina
about Y^,T of an inch.

Carboniferous Limestone, Marble Canon, British Columbia*

DESCRIPTION OP PLATE TI.

Fig. 1 reprcponls portion of a tran?pnrpnt section, nearly at right angles to
the longer axis of iho Foraniinifcr. Tlio test is represented by the
darker wliading. wliile more transparent calcite fills the. cliambers. The
primary lamina is designated by a, and is seen to bo thickened by the
spongy ingrowth, h designates one of the more perfect secondary
growtiis or septa. IVIany of the tertiary ingrowths end proximally
before reaching the inner lamina ; this may arise in some cases from
the sliglit obliquity of the ))lane of section to the direction of their
axes. I'hat the section is not truly through tho centre of the form is
seen at d, where it becomes tangential to tho inner layer, and exhibits
a portion of the ni'imary lamina in pbm. (X 2.").)

Fig. 2 is a portion of a longitudinal section of the outer part of the te.st. o
designates the primnry Inmina ; c tho tertiary processes or pillars, e, /,
& J refer to tho acervuline or irregular exterior portion, wellde\e-
loped in this specimen. At e an irregular tier of chambers has been
formed, which pass outwards in some pbices almost imperceptibly into
d, a spongy or cancellated mass, which is generally limited exter-
nally by a more or less definite wall, g. The secondary growths, or
septa, are not seen in this section, and this is very frequently the case
ill longitudinal sections. It arises partly from the greater transpa-
rency of these as compared with tiie thickened floors and the pillars, and
apparently partly also from the circumstance that they are in reality
more fragile. (X 2o.)

Fig. 3 represents a portion of a longitudinal tangential section, which is very
instnictive, as showing nearly all parts of the test. This may profi-

LOI'TCSIA FROM ItRITlSU COLUMIIIA. 75

tiibly bo compared with that given on plute Ixxix. fig. 1 of Messrs.
Carpenter and IJrady's rnoinoir, a indicates a part of the primary
hiruina, which is thickened, as before described, and may consequently
be seen as a series of ratlier broad dark zones, indefinite oti tlieir inner
edges, and runniii!,' parallel to each olher. i points out one of the
beeondiiry gnnvtlis or sejtta; these maybe seen running parallel to the
longiludinal axis of the form. They ai)pear wi(U', from being cut ob-
licinely, but also, in many cases, from the identilii^alion with them of the
htngitiidinal rods or rafters formed by the ex])ansi()n of the pillars.
At right angles to these, at /, are seen rods formed by the nni(m, trans-
verse, to the axis, of the distal ends of the pillars. At c the section
becomes nearly radial, and the pillars are seen as in figure 2. At d
part uf the thiekened primary laiiiiiui is shown in plan. (X-o.)

Fig. 4 is nearly longitudinal and radial, representing part of three folds of the
jn-iniary lamina (ri) and the pillars uniting them (c). The irrcmla-
rities of tiii'se are shown, and the cancellated growth from the inner
side of the lamina is indicated by //. (x T.'i.)

Fig, 0. Portion of tlu^ thickened primary lamina shown in plan. At c/ the
greater part of the spimgy thickening has been removed in grinding
down the section. The rafter-like thickenings from the intersections
of which the colunnis 8i)ring are here clearly .seen. The darker zone
sun- )iMuiiiig this part represents tiie primary lamina and its thicken-
ing (//) ohli(|ucly cut. Where, at the edges, the section becomes more
nearly at right angles to the curved lamina, the piUars may be seen
running out. (x 75.)

Fig. 0. Transverse section through the nucleus of a very young specimen, show-
ing the first convolutions. (X 4.'>.)

Fig. 7 represents the external form of the organism of actual size. The figure
on the right is of au unusually long variety.

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