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((\() COMPARATIVE ZOOLOGY,

AT HARVARD COLLEGE, CAMBRIDGE, MASS.

Founded by private subscription, in 1861.

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No. J 434.

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Ae HMontreal :
PRINTED. ‘BY JOHN LOVELL, ST. NICHOLAS STREET.

1859.

GEOLOGICAL SURVEY OF CANADA.

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

FIGURES AND DESCRIPTIONS |

OF

CANADIAN ORGANIC REMAINS,

DECADE I.

HM*aontreal :
PRINTED BY JOHN LOVELL, ST. NICHOLAS STREET.

1859.
C

NOTICE.

In the preface to Decade III., already published, the reason has
been given why the present one, though second in time, is first in
number. In the same preface it has been stated that the present
Decade, confided for the descriptions to Mr. J. W. SALTER, palzon-
tologist to the Geological Survey of the United Kingdom, is intended
to illustrate a commingling of forms heretofore supposed to belong
to distinct epochs; that the drawings are by Mr. Bons, and the

engravings by Mr. SowrErsy, artists well known for their accuracy
and skill.

W. E. LOGAN.

Montr@aL, 11th April, 1859,

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PREFACE.

In describing the few generic types given in these pages, I am
acting as pioneer for my friend Mr. E. Billings, who wishes me to
share this portion of his task, and I very willingly join with him,
and with Professor James Hall, in commencing this series of
Decades. The drawings and plates have been executed for some
time past.

In a short memoir on the fossils collected in the limestone at
Pauquette’s Rapids, on the Ottawa River, which was presented to the
British Association in the year 1851, and appended to Sir William
Logan’s paper on the Rocks of Canada, it was stated, that the lime-
stone included fossils characteristic of all the lower divisions of the
New York system, from the Calciferous sandrock to the Trenton lime-
stone inclusive. With regard to the lowest of these strata, a correction
may be made, for, when more closely examined, the Euomphalus
uniangulatus of that rock appears to be somewhat different from the
Ottawa shell referred to it. The other limestones are certainly
represented ;—the Chazy by the peculiar genus Maclurea, and the
Birdseye and Black-river limestones by some identical corals and
shells. With the Trenton formation, as might be expected, the
affinity is greatest; and the beautifully preserved fossils, silicified
in a pure calcareous matrix, and weathered extensively, permit of
accurate comparison with the figures and descriptions of those from
the United States. ;

In this collection from a single calcareous band, we meet with
the Bellerophon sulcatinus and B. rotundatus of the Chazy limestone ;
Murchisonia ventricosa and the Stromatocerium from the Birdseye.

vis PREFACE.

There are Black-river limestone species, viz., Columnaria alveolata,
and the remarkable cephalopod, Gonioceras anceps, of Hall. Of
Trenton species, we have in abundance the Strophomena filitexta,
Pentamerus (atrypa) hemiplicatus and Atrypa inerebescens, Murchisonia
gracilis and M. bicincta, Cyrtoceras annulatum and C. lamellosum of Hall
(C. Billingsii of this Decade), Orthoceras areuoliratum, bilineatum and
laqueatum of Hall, together with Ormoceras tenuifilum, a fossil common
to both the Trenton and Black-river limestones. Schizocrinus nodosus
is the common Crinoid, and species of Petraca (Streptelasma), with
Favosites lycoperdon, go to swell the list of Trenton species. Lastly,
there is the characteristic Asaphus gigas, so that the parallel is
complete.

J. W. SALTER.

CANADIAN ORGANIC REMAINS.

MacturEeA Locant, Salter.
Decade I. Plate I.

Generic character —Maclurea, Lesueur. Mollusca Nucleobranchiata.
Family Atlantida? ‘Shell discoidal, few whorled, reversed*
(the apical whorls being brought down to the base and the
umbilicus flattened out); upper surface convex, deeply perfo-
rate instead of raised into a spire; outer side spirally grooved ;
operculum sinistrally sub-spiral, solid, with two internal pro-
jections for the attachment of muscles—one of them beneath the
nucleus, and very thick and rugose.”—-WoopWARD.

Synonyms.—M. Logani, Salter, in Rep. Brit. Assoc., 1851, Trans.
Sections, page 63; in Murchison’s “ Siluria,’”’ 3rd edit., 1859,
page 215, figure 1 (?) and 1a, operculum.

Diagnosis.—M. 33 uncias lata, paucispirata; anfractibus 4-5 (ultimo
m latitudine precedentem ter superante), subtus planissinis levigatis,
et ad latera multistriatis insuper, valde convexis, umbilico parvo.

This fine species, detected in great plenty by the officers of the
Survey in exploring the Ottawa river, was first noticed in Sir R. I.
Murchison’s paper on the Silurian Rocks of the South-west of Scot-
land, in the Quarterly Journal of the Geological Society, vol. vii.,
1851, page 176, and its name proposed in the British Association
Reports for the same year.

* The reader will please to bear in mind, that though drawn uppermost on the plate
(a position which shews the characters best), the flat spiral side of the whorls is really
to be considered the base, and the umbilicus the upper side. See Woodward’s Manual
of Shells, p, 202, where the shell is represented (fig. 106) in its normal position.

8 CANADIAN FOSSILS.

It is clearly distinct from, though closely allied to, the great
Maclurea magna of the Chazy limestone, which may be seen so often
in the paving-slabs and door-ways of New York, and which has been
well figured by James Hall.

The genus is by no means rare in the old deposits of the Silurian
seas, and apparently there were several very distinct species, some
of which are yet unpublished, and one, M. Peachii (Salter), which
has the operculum extravagantly elongated and curved, occurs in
plenty in a rock very like the Canadian limestone, and full of similar
types, in the north-west angle of Scotland. It has been figured,
and its locality described, by Sir R. I. Murchison, in the Quarterly
Journal Geological Society for 1858. Another is plentiful in the
Llandeilo limestones of the south of Scotland.

Description.—M. Logani, when perfect, is fully three and a half
inches wide, and is conspicuous for the great flatness of its lower or
whorled side, and the fewness of its whorls, for, if we except one or
two minute inner ones, there are but two or three distinct whorls,
which diminish so rapidly in breadth that the outer is at least thrice
the width of the preceding ones in succession, and greater than that
of all the inner whorls taken collectively: in M. magna it is greatly
less than these. The whorls are very gently convex between the
sutures, which are sharply marked though not deep, and are closely
striated by regular sharp-arched lines of growth. The sides of the
whorl are steep, pyramidal, the depth exceeding the width of the
whorl, and are furrowed by a number of deep grooves, sometimes
16 or 17, a few of which are interlined with smaller ones. Occa-
sionally seven or eight only are present, or a deep one (figure 3)
occurs at a short interval ; but this may be the result of injury.

The base itself is smooth, or with faint concentric striz only, and
the umbilicus* rather abrupt and very narrow, not above one third
the width of the whorl, and with a rounded edge. The shell is solid,
nearly a line thick.

The most singular part of the shell is its operculum, sometimes
fixed, as in figure 3, in its normal position, at other times drawn
within the shell. It is exceedingly solid, the successive layers are
subspirally arranged, tiling over one another, and are antiquated in |
growth. The nucleus is near the inner and lower angle of the mouth ;
in old shells it is pushed further out, and becomes the apex of a very
solid short cone, one face of which lies close upon the inner flat

* Used in a false sense, since it is the perforate spire.

CANADIAN FOSSILS. 9

surface of the whorl. Two curved furrows radiating from the nucleus
divide the surface into three areze, less distinct in the mature shell.
Inside, a thick compressed process (a) takes its rise beneath the
nucleus, retaining its place near the inner angle of the mouth, even
in the adult shell, when the nucleus itself has removed further out
(figure 6). The process is as broad as long, and on its oblique free
margin it is roughened and grooved for the attachment of muscles.
Another attachment, similar but much less prominent, exists at the
inner and upper angle (4), and a line of minute prominences partially
connects the two.

These processes have their analogues in the internal ridges of. the
operculum in Nerita and some other genera, and in that of the small
Pteropod shell, McGillivrayia (Forbes), but no recent shells are
known in which they are equally produced.

The view above expressed of the shell being a reversed one in
which the spire is deeply sunk, in the so-called umbilicus, and the
latter expanded and flattened so as to appear like the upper side in
ordinary Shells, will not appear unlikely, if comparison be made with
Ophileta (plate 3), in which there is a similar condition of the spire.

Moreover, this view has the advantage of rendering it unnecessary
to suppose an operculum arranged on a different plan to that of
ordinary univalves, since no case is known in which the nucleus is
placed at the upper angle of the mouth, though some few have it
external. The genus Atalanta however, says M. Woodward, has the
spire and the operculum both sinistral; hence it is possible that
Maclurea might be an opposite case, in which it is dextral in both.

The alliance of this heavy shell with the lighter and fragile
Nucleobranchs would seem much more unlikely, had we not such
solid forms as Bellerophon to compare it with. But there are no
other genera with which it can be better asseciated, since Euompha-
lus has quite a different operculum (multispiral), and no opercula are
known in Ophileta or Raphistoma, depressed forms resembling Maclur:a,
but which are probably, with Murchisonia, members of the families
Janthinide or Trochide (see plates 2, 3). Prof. Forbes believed there
was some affinity between Maclurca and McGillivrayia, above men-
tioned, a minute spiral Pteropod with the nucleus of the operculum
external, and with a process beneath it. But this affinity is not so close
as that suggested by Bellerophon with the Nucleobranchs, and we must
_ therefore leave it for the present where the judgment of Mr. Woodward
has placed it, and regard Maclurea as a Heteropod with a heavy shell,
and probably stationary or nearly so on the bottom, seeing that its

10 CANADIAN FOSSILS.

upper or convex side is constantly overgrown with sponge (Stromato-
cerium rugosum*), while the flat or lower side preserves the sharp lines
of growth, which would have been abraded had the animal been
endowed with much locomotion.

RAPHISTOMA, HELICOTOMA, AND OPHILETA.
Decade I. Plates II. and III.

Genus Scalites, Conrad. Mollusca Gasteropoda. Family Ianthinide.
Shell thin, turbinate or depressed, with angular whorls, flat
above ; aperture deeply notched, but without a band.

Sub-genus Scalites. Turbinate; whorls flat above, turrited, pro-
duced below; umbilicus none. ‘Form elongate.

Sub-genus Raphistoma, Hall. Depressed, often discoid; spire flat,
or only gently convex, with close sutures; whorls acute angu-
lar externally, and often with an angular edge to the moderate
umbilicus. Form lenticular.

Sub-genus Helicotoma, Salter. Depressed, discoid ; spire nearly flat ;
whorls obtusely angular externally, rounded below; umbilicus
broad. Form cirrhoid or helicoid.

Sub-genus Ophileta, Vanuxem. Discoidal; spire sunk above ;
umbilicus below perfectly open, and exposing the whorls all on
one plane; whorls numerous, truncate and biangular exteriorly ;
mouth trigonal. Forms with deeply concave spires.

On mature consideration I cannot find any reason for separating the
above series of forms, except as sub-genera. They pass into each
other by almost insensible degrees, some species of Eaphistoma, for
instance, being merely depressed Scalites, while others need but a little
more angularity below to become species of Ophileta. Helicotoma
is a new sub-generic form, which I have been obliged to institute in
order to express a middle term of the series, one in which the true
discoid form of Raphistoma is maimtained, without the extreme angu-
larity of that genus, yet with a spire almost as much sunk and an

* A fossil of the Chazy and Birdseye limestones of New York. The Maclurea may
thus be regarded as representing in this rich locality the Chazy limestone, which is still
farther illustrated by such species as Bellerophon sulcatinus and B. rotundatus. See
Preface.

CANADIAN FOSSILS. 11

umbilicus as greatly exposed as in Ophile‘a. All are Lower Silurian
forms, and from near the base of the system, and all, with the excep-
tion of Scalites proper, which does not occur in the Ottawa limestone,
are illustrated in plates 2 and 3.

The genus must be regarded, in the present state of our knowledge,
as allied to Pleurotomaria and Murchisonia (which, with Scissurella, is
now considered* to belong to the Trochide), but differing from
them importantly in the want of the spiral band. It is probably
nearer to Janthina, some of the typical species of which are strongly
striate in the direction of the lines of growth, and deeply notched in
the middle of the mouth. These thin floating shells certainly seem
to offer the best affinity with Scalites and its various sub-genera ;
and inasmuch as Janthina is arranged as a family close to the Trochide
and Haliotide, the association of Scalites with the former would not
call in question its relationship to the latter. Both Janthina and
Scalites have but few whorls and a short spire (in the fossils with a
much greater tendency to a depressed shape) ; while the Trochidz
and Murchisonia are on the contrary elongate and many-whorled.

The total absence of opercula, while it rather strengthens this
view of the affinities of Scalites, throws some doubt on the propriety
of keeping Murchisonia among the Trochide. Professor E. Forbes
would have arranged all these thin-notched shells, with Platyschisma
(McCoy), and some other palaeozoic genera, alongside of Tanthina.

RAPHISTOMA.

I have altered but little the essential parts of Prof. Hall’s deserip-
tion of the genus. The main characters by which the sub-genus is
distinguished are pointed out by him, viz.: the close-fitting sutures
between the whorls, and the subtrigonal, not rounded, form of the
mouth, caused by the production of the outer angle.

There are two sections even of this sub-genus, one with flat spire
and the whorls convex below (R. striata, Hall), the other with spire
and base about equally convex, and a general lenticular form
(R. staminea, Hall, R. lenticularis, Sowerby, &c.). Tne two species
here described belong to the second sub-division.

* By Mr. Woodward, the author of the “ Rudimentary Treatise on Recent and Fossil
Shells.” John Weale, London, 1854. This excellent work contains in a condensed
form the fruits of much research, and is highly prized by European naturalists.

12 CANADIAN FOSSILS.

R. LAPICIDA, N. sp.
Plate II. Figures 1-3.

R. uncialis, discoidea, lenticularis, margine acutissimo : anfractibus 4 levi-
gatis, supra planis, atque suturis inconspicuis, subtus convexis ;
umbilico angusto rotundato ; ore ovato acutissimo. Diameter, 10
lines; alt., 54 lines.

This elegant shell a good deal resembles the R. staminea of Hall’s
work (Pal. New York, vol. i., pl. 6, fig. 4, 5), from which it is readily
distinguished by the less raised spire, flatter base, and larger umbili-
cus. It is altogether a flatter and smoother shell, the lines of growth
not sharp and regular, and on the upper surface there is no concentric
ridge to interrupt the backward course of the striz. And comparing
it with other American species, the R. (Maclurea) labiata, Emmons,
and the very similar R. (Pleurotomaria) lenticularis of the same author
(not of Sowerby), have both more convex bases, the outer face of
the whorl below being almost vertical in the former, and at least
convex in the latter, instead of first concave and then prominent.
The umbilicus in both is too large for ours.

The whorls of the spire slope regularly to the apex without inter-
ruption at the sutures, the last whorl excepted, which descends a
little beneath the margin of the preceding. The edge is very acute.
The under-side, only a little more prominent than the spire, is first
concave beneath the keel, then convex towards the deep narrow
umbilicus with its incurved sides. The striz of growth are more
conspicuous below than above. The rounded sides of the umbilicus
easily distinguish R. lapicida from the next described species. The
inner lip is prominent and a little reflexed. The angle of the ovate
mouth very acute, and the notch deep, but the lower margin does
not project greatly forward.

A general resemblance to Helix lapicida suggests the name.

Locality —Allumette Island.

R. APERTA, N. sp.
Plate II. Figure 4.

R. semiuncialis, anfractibus 4 insuper depressis, subtus perangulatis: umbi-
lico latissimo infundibulato ; ore rhomboideo. Diameter, 6 lines ;
alt., 3 lines.

The whorls are of about the same proportionate width as in the

CANADIAN FOSSILS. 13

last species, four of them in the diameter of half an inch; they are .
not quite flat above, but gently convex between the sutures. Below
they are strongly angular at about the middle of the volution, the
outer face being plane, and the umbilicus broad and conical, with
slightly curved sides; its width is fully half the entire diameter of
the shell.

The mouth is rhomboidal, as high as wide, the outer angle about
80°, its lower and inner margin defined by the angle and sloping
wall of the umbilicus ; the margin not reflexed.

This has a more convex base than the R. ( Pleurotomaria ) subtili-
striata (Hall*), which nevertheless appears to be of the same genus.
P. lenticularis, Emmons,t also resembles ours, but it is a larger shell,
and less angular below.

R. aperia is however so like R. (Euomphalus) qualteriata of Schlot-
heim from the Lower Silurian limestones of St. Petersburg, that but
for the greater size and less elevated spire, it might be taken for the
young of it. A. qualteriata however seems constantly to be more
depressed above, and the outer angle therefore of the mouth not so
equal-sided as ours; nor is the umbilicus quite so broad or so
decidedly angulated.

There are several other species of Raphistoma in the Canadian
limestone, one an inch and a half in diameter, slightly concave at the
sutures, and with large angular umbilicus.

Locality.—Allumette Island.

HELICOTOMA.

The characters are given above, and only four species are yet
known—one the H. (Euomphalus) uniangulata of Hall, from the
Calciferous sandrock of New York, and the three species here given.
H. planulata should stand for the type of the sub-genus, which. is less
regularly depressed than Raphistoma, and without the reversed umbi-
licus of Ophileta, though with a much larger one than the other
sub-genera.

* Paleontology of New York, vol. i., plate 37, figure 5.
t Geology Second District, New York, page 393 (not of Sowerby).

14 CANADIAN FUSSILS.
H. PLANULATA, N. sp.
Plate II. Figure 5-7, and Variety, figure 8.-

H. unciam lata, anfractibus 4 gradatis, concentricé sulcatis, supra planis ;
carina ad angulum externum elevaté ; basi tumido laté umbilicato.

Synonym.—[ Euomphalus uniangulatus, Hall, Paleontology of New
York, vol.i., plate 3, figure 17] Scalites uniangulatus, Salter, in
British Association Reports for 1851, Trans. Sect., p. 63.

Prof. Hall’s specimens of the very nearly allied Exomphalus unian-
gulatus are so depressed, that “ the spire scarcely rises so high as the
angular ridge on the upper and outer edge of the last whorl.’? Ours
are generally more elevated. His specimen too shews the umbilicus
entirely open, and the shell therefore truly discoidal, while in ours
at least half the whorl on the lower side is covered by the preceding
one. They are probably therefore distinct species.

The general form is depressed, the whorls being nearly flat above,
and rising a little above each other in a step-like manner, each whorl
nearly twice the breadth of the preceding. They are bluntly carinate
on their outer upper angle, and the carina is elevated (but is not a
‘true band), the distinct lines of growth being curved backwards to
it, and beneath it bent abruptly forwards. The whorl is concave
for a short space beneath the keel, and then tumid over the sides
and base. Concentric furrows occur on the margin to the number
of four or five, and are often duplicate, three of the intervening
ridges being more conspicuous than the rest.

The base is smooth, except the prominent lines of growth; the
umbilicus steep, nearly half of each whorl exposed in it, and its
edge is not angular, except in the young whorls.

The mouth is rounded, about as high as wide, and has the upper
margin retreating towards the deep notch, and the lower edge
brought forward. No reflection of the inner lip takes place in this
species, and the general aspect is that of Ewomphalus.

Variety Muricata. Figure 8.

Instead of the plain ridges round the outer border of the whorl,
there are three spinose or tuberculate ridges (like those of HL spinosa,
figs. 9, 10), but the tubercles are not strictly regular in position on
the ridges, though they occur all round the shell. They may be
extraneous, and so may those of the following species.

CANADIAN FOSSILS. 1b.

The upper surface of this variety is concave, not flat.
Locality—Allumette Island, in siliciferous limestone.

H. spinosa, N. sp.
Plate II. Figures 9, 10.

H. viz semiuncialis, anfractibus 4-5, paullo elevatis, extus carinatis, supra
planis seu sub-concavis tuberculisque cristatis sparsis, sublus convexis ;
umbilico angusto verticali ; ore sub-rotundo.

Whether the spinose ornament be considered structural or extra-
neous, this is certainly very distinct from all the varieties of the last
species, and more elegant in outline. The shape of the deep umbilicus,
with its vertical sides, is a good deal like that of H. larvata next
described, but the form of the shell is much more depressed.

The upper surface is rather thickly studded over with tubercles,
which are disposed in sub-concentric rows, one row of large com-
pressed crest-like tubercles along the outer carina, an imperfect row
within this on the upper concave surface, and several incomplete
rows of smaller size on the outer convex edge. All have an irregular
appearance, and it is more than probable are only the relics of a
papillate sponge, converted into silex, and having its projecting
portions determined in position by the ridges of the shell.

H. LARVATA, N. sp.
Plate II. Figure 11-14.

EI. semiuncialis, levigata, spira lenté elevaté ; anfractibus 5, supra sub-con-
cavis, subtus convexissimis ; umbilico verticals angusto: ore rotundato
margineque acuto valde sinuato.

This shell is covered so frequently with a coat of the sponge,
Stromatocerium rugosum, as to suggest the specific name. The upper
side or spire only is covered, just as the Halichondria panicea invests
the Buccinum and other common univalves of the British coasts.
(See Johnston’s “ British Zoophytes,” 1st edition.)

Some specimens however, which are free from the parasite, shew
the spire to be composed of five gradually increasing whorls, each
about one and a-half times the width of the preceding. The whorls
are slightly concave on the upper side, which is divided by an
angular ridge from the convex outer border. The base is regularly

16 CANADIAN FOSSILS.

convex, the umbilicus deep and rather narrow, bounded by a sharp
edge which cuts the lower angle of the mouth about its middle.

The mouth itself is rounded, very deeply notched at the upper
angle, and the edge then curves strongly forward and forms a pro-
jecting outer lip. The inner margin again retreats very considerably,
and has a sharp, almost cutting edge. The lines of growth in the
umbilicus follow the curve of the edge of the inner lip, which is
somewhat excavated, as in species of Natica, Littorina littorea, etc.,
by the reflection of the mantle’s edge.

The entire form is very compact, and the smooth lower surface
being convex, with small, deep, regular umbilicus, the shell has a
good deal the aspect of a land-snail, a resemblance at once contra-
dicted by the angular umbilicus, the sharp retreating inner lip, and
the notched and projecting outer one.

The last two species violate in some respects the character of the
sub-genus, having the small umbilicus of Raphistoma, with an angu-
lar edge. In truth they might be included with the former sub-genus,
and are retained here on account of the rounded, not triangular mouth.
Raphistoma is better typified by such species as have a flat or regularly |
conical spire, a triangular mouth, and a small umbilicus. It is
always difficult to define the limits of sub-genera, for they are mostly
convenient, rather than absolute, groups.

OPHILETA, Vanuxem.

The characters given by the author of the genus merely describe
its general appearance, and do not indicate its relations to Raphistoma
or the other allied sub-genera. It appears to be strictly confined
to the lowermost of the calcareous strata which lie upon the Potsdam
sandstone, and holds the same place in Scotland as it does on the
American continent.

O. compacta, Salter.
Plate III.

O. magna, sesquiuncialis, anfractibus 5-6, utrdque perangulatis, supra
profunde excavatis, infra planissimis; ore trapezoidal fere trigono,
facier interna angustissima externa biangulata,—verticalt.

So few species are known of this genus, that it is not necessary to
be minute in the specific character. This is by far the largest known.

CANADIAN FOSSILS. LT

Prof. Emmons’ O. complanata, as figured by Hall (Paleontology of
New York, vol.i., p. 11), is nearest in size, but is still greatly smaller,
and has even more whorls in ashell of half the diameter. O. levata
is a minute species. |

At first sight this shell, like the Maclurea (plate 1), appears to be
reversed or left-handed, the flatter side apparently being the spire,
as in'many Euomphali, and the concave one the wide umbilicus
(Euomphalus calyx, of the mountain limestone, in form greatly
resembles fig. 3). But when comparison is made with such forms
as that last describe1—Helicotoma (H. uniangulata, for instance)—the
real affinity is manifest ; although the evolution of the whorls is
extreme in the present case, the direction of the lines of growth is
decidedly similar in the two genera.

Diameter, about one inch and a half, and height of outer whorl
about six lines.

General form thick-discoidal, the upper side shewing five or six
whorls, rather slowly increasing in size, steeply concave from the
outer margin, so as to form a hemispheric cup. The whorls have
each a sharp keel outside, which rises prominently above the general
concave surface (in the cast making deep impressed furrows, fig. 1),
and the lines of growth are turned considerably backward, from the
suture to the prominent upper keel, a. On the outer vertical face
they make a bold curve forwards, retreating again, fig. 4, to the
lower angle, 6.

The umbilical face, fig. 2, makes nearly a right angle with the
vertical outer margin. We are unacquainted with the course of the
lines of growth over this. The mouth, fig. 1 ab, is trapezoidal, the
inner side, c, vertical like the outer, and parallel to it, but not above
half the length. Fig. 1 being reversed, the lower or square angle of
the mouth is indicated at c. The upper side, fig. 3.ad, takes of course
the same slope as the spire generally, and forms with the (en face
an angle of less than 45°.

The species has been quoted by me from the Lower Silurian rocks
of N. W. Sutherlandshire, where it occurs in a thick cher ty limestone
overlying quartz rock.* A fresh comparison shews only very trifling
differences. The English fossil is not quite so large, and has rathet
more whorls in a given space ; but these proportions vary, and the
form is exact. The O. (Maelurea) sordida appears to accompany it
in Sutherlandshire as it does in Canada and New York.
poe Ne SN 2 AEE Wag 0 he er A RCA

* See Sir R. I. Murchison’s Memoir on the Rocks aF the N. W. of Scotland. Quar-
terly Geological Journal, vol. 14, ined.

B

18 CANADIAN FOSSILS.

Locality.—F ound in a hard, brownish, calcareous sandstone (Cal-
ciferous Sandrock) at Beauharnois, near Montreal, associated with
the Ophileta (Maclurea) sordida of Hall. The latter species has
much fewer and more rounded whorls, but it is probably of the same
sub-genus, as there are intermediate forms connecting this sub-genus
with Raphistoma.

Murcuisonta, D’Archiac and DeVerneuil.

Generic characters ——Murchisonia, DeVerneuil and D’Archiac. Mol-
lusca Gasteropoda. Family, Trochide (see Woodward, 1858).
Shell elongated, many-whorled; whorls variously sculptured,
and zoned like Pleurotomaria by a spiral band; outer lip
deeply notched ; aperture slightly channeled in front.

Section 1.—Murchisonia, proper. Turbinate shells, with angulated
and variously ornamented whorls, the band generally most
prominent; mouth ovate, produced below.

Section 2.—Hormotoma. Elongate, beaded, with round whorls having
a distinct band and notch, as in the other Murchisonia ; mouth
rounded, not effuse.

The shells which the above distinguished authors separated under
this name, were long classed with Plewrotomaria, with which they
are closely allied. They bear the same relation to the Pleurotomarie
of the Paleozoic rocks that Pleurotoma does to Conus; indeed there
seems to be an almost perfect gradation between them. If the
spire of a Plewrotomaria be lengthened, it becomes a Murchisoma;
and, in like manner, if the produced mouth and spire of Murchisoma
be shortened, the Trochoid forms so common in the Carboniferous
limestone are again produced.

Probably both these genera are allied to Scissurella, which is not
a pearly shell, rather than to the true Pleurotomarie of the Oolitic
rocks, which are nacreous, and clearly allied to T'rochus. But we
have not the means, in the absence of the operculum, to establish
this point.

Prof. E. Forbes thought the whole group of these thin palzozoic
shells with notched apertures were related to the Ianthinide. And
it is probable this is a correct view, though these could scarcely be
pelagic forms, associated as they are with numerous other types of
molluscs, annelides, crustacea, etc., and frequently found gregarious

CANADIAN FOSSILS. 19

in sandstones and conglomerates which must have been formed in a
shallow sea. They appear to have inhabited however every kind of
sea-bed (though more abundant in those of a sandy character), and
are common throughout the limestones of the New York —
Canadian series.

It is probable that the angular-whorled and_ strongly-striated
species belong to a different genus from the elongate, beaded forms.
But they are at present kept together under one name, as sub-genera.

M. sicincra, Hall.
Plate IV. Figures 5, 6 (and 7 junior).

Specific characters—M. pyramidata, biuncialis, anfractibus 6-7, acuti-
angulatis (valde distinctis), levigata—carind primarid crassa trili-
neatd supra medium anfractiis—secondrid obtusd ad suturam positis ;
umbilico parvo ; ore ovato effuso.

Synonym.—M. bicincta, Hall, Paleontology of New York, vol. i
plate 38, fig.5. [M. perangulata, ib., plate 10, fig. 4, junior.]

The shape of this common and fine species is rather abruptly but
regularly pyramidal, the spire composed of six or seven whorls, each
sharply angulated in the middle, or rather beneath the middle in the
whorls of the spire, but considerably above it on the body-whorl:
The keel is thick and prominent, ornamented with three faint-raised
threads, one along the middle.

Beneath the principal carina a second, much less prominent a
obtuse, abuts against the suture (in the spire), and occupies a position
rather below the middle of the body-whorl. The slope of the whorl
above the principal keel is nearly straight, not concave; between
the principal keel and the lower one a little concave, and beneath
the last the whorl is convex as far as the small umbilicus. The
mouth is ovate, gently effuse at base, and the columellar lip snupet
and reflected, but apparently not closing the umbilicus.

The surface, unlike that of most of the accompanying species, is
smooth; the lines of growth obscure, but a good deal bent back,
The triple keel is not serrated or even decussated by them, but quite
even-edged.

M. perangulata, Hall, has a more elongate spire, but does not
appear to differ specifically from young specimens of M. bicincta.
Those from Canada are more like what Prof. Hall has figured from

20 CANADIAN FOSSILS.

the Birdseye limestone; that in the Trenton limestone (pl. 38, fig. 7)
seems a more elongate species. Our specimens may however be
distinct, as the author does not mention the small carina round the
sutural edge of the whorl, conspicuous in M. becincta when young,
but much fainter when full-grown. The base too is less convex and
the umbilicus more distinct. But these are minute differences, and
from examination of a series, I am much disposed to unite the two
species.

Locality.—Allumette Island. There is another species associated
with these, and differing chiefly by having strong upper and lower
keels; and there are several new Pleurotomaria, distinguished by
their shortened form from the present genus.

M. SERRATA, N. sp.

Fig. 1.

5

M. laté conica, spird brevi ; anfractibus 4 acuticarinatis, carinis 4 serratis,
spaluis intermediis concavis et striis conspicuis ; busi convero, ore rotun-

dato.

The spire is less produced than in the preceding, forming an angle
of fully 55° or 60°, and composed of four acutely carinate whorls,
deeply separated at the sutures. The body-whorl is furnished with
four keels—the principal one very prominent about the middle of the
body-whorl ; one keel above it, near the suture; another at an equal
distance below; on the convex base there is a fourth, which surrounds
at some distance a rather large umbilicus, the sides of which are
very convex. The keels are all more or less serrate, the principal
one especially so (and not so much undulated as our figure shews) ;
and the spaces between them are deeply concave—that between the
upper keel and the suture nearly horizontal, but still hollowed out.
The lines of growth are sharp and equidistant, decussating the keels
to produce the serrate edges, and bending back considerably to the
central prominent one, which is SO narrow as not to shew a distinct
band.

This beautiful species is more sharply keeled than any other
Silurian species known to me, and reminds one of some of the
Carboniferous forms.

Locality Allumette Islands.

CANADIAN FOSSILS. 21

M. HELICTERES, N. sp.
Plate IV. Fig. 2-4.

M. turrita, biuncialis, anfractibus 5 sxb-rotundatis, tricarinatis antiquatis,
ultimo vago: carinis omnibus obtusis, mediand (cingulo) latd ; stris
crebris asperis.

This shewy species is not more remarkable for the irregular uncoil-
ing of the last whorl (resembling in this respect certain varieties of
the common snail, Helix aspersa*), than for the rough striation and
antiquated appearance of the whorls.

The band or principal keel is broad and flat, the upper and lower
edges being prominent, and the middle only a little convex; the
rounded notch is rather deep. The upper and lower keels are obtuse,
and equally distant from the band, the upper placed about half-way
towards the suture, which is not at all channeled ; its edge on the
free whorl shews as an obtuse ridge. See figure 3s.

The spire is pyramidal, but the separate whorls are rounded; the
upper ones have the inferior carina covered by the suture, but it
is exposed in the lower one by the divergence of the last whorlt
figure 2, which afterwards becomes quite free, figures 3, 4.

Tne striation is very rough and coarse ; the lines of growth cross-
ing the ridges, give these an antiquated appearance. The mouth is
round; the shell thickened, especially on its inner side.

In the thick, obtuse whorls, coarse striation, and broad band, this
species a good deal resembles M. semirotundata, McCoy, from the
Caradoc formation of N. Ireland, but that species is destitute of the
upper keel, besides having much rounder and more ventricose whorls.

M. tricarinata, Hall, (Pal. New York, vol. i., plate 38, fig. 6,) is a
Trenton species much more resembling our shell; but his specimens
are too imperfect to identify with, particularly as he mentions
nothing of the tendency to uncoil, and distinctly says there is no
umbilicus; the carinze, too, are represented as sharper than those of
our species. Moreover, the mouth is said to be “acutely” produced
below. It has, however, similar sharp prominent strize, and is pro-
bably very nearly allied.

Locality —Common at Allumette Islands.

* See Gray’s edition of ‘‘ Turton’s Manual of British Shells.” (Vignette.)

22 CANADIAN FOSSILS.
Section HORMOTOMA.

Elongate, beaded forms, like Holopella, but with a distinct band
and notch, as in the other Murchisonia. Mouth rounded, not effuse.

M. GRAciiis, Hall.
Plate V. Figure 1.

M. elongata, biuncialis, anfractibus 10-13, ventricosis, rotundatis (supra
viz planulatis ), cingulo central lato, etiam quariam partem anfractés
e@quante.

Synonym.—Hall, Paleontology of New York, volume i., plate 39
figure 4; page 181.

This gracefully-formed species belongs to a group of Murchisonie,
which doubtless ought to be separated generically from the more
typical angulated forms. They resemble Holopella, McCoy (the
so-called Turritelle of the Silurian rocks), in the elongate, beaded
form, and round, instead of oblong and effuse, aperture. The band
however effectually distinguishes them. The inner lip, too, is
reflected on the columella, which is probably not the case with
Holopella.

M. gracilis is a fine species, full two inches long, and very gradu-
ally tapering; of about twelve or thirteen round whorls, which are
only very slightly flattened on the upper side, above the band.
The latter is broad, equal to about one-fourth the whole width of
the whorl, and placed centrally or a very little below the centre.
(On the centre,” Hall.) The striz, which are close but not
_ prominent, curve sharply backward to this band, and forward again
beneath it.

The slight angularity of the whorls is alluded to by Prof. Hall,
who compares it in this respect with the larger species, M. bellieincta,
of the same limestone. This slight angle does not however detract
from the general roundness of the volutions, as represented in the
figures above referred to. It is an exceedingly plentiful species.

Our figured specimen has the outer portion of the last whorl bro-
ken away so much that the inner lip (a) looks far more conspicuous
than it is in reality. It is slightly reflected over the columella.

Locality— Abundant in the slabs of limestone at Pauquette’s
rapids, etc.

CANADIAN FOSSILS. 23

M. venrricosa, Hall.
Plate V. Figures 2, 3.

M. turrita, anfractibus rotundatis ventricosis levigatis, superné subangula-
tis, et cingulo lato marginato prope suturam posito ; ore rotundato.

Synonym.—M. ventricosa, Hall, Paleontology of New York, vol. i.,
plate 10, figure 3.

The position of the band easily distinguishes this fine species from
the M. bellicincta, Hall, with which its size and general shape would
lead us at first sight to identify it. It has the same proportions of
spire, and convexity of the whorls, and the pillar-lip is straight, as
described by Hall, though his figures do not clearly shew this
character.* But the band, instead of being nearly central and rather
narrow, is broad, flat, and placed so high up as to be less than its
own breadth from the suture; while the lower margin forms the
prominent angle seen above the middle of the whorl. The lines of
growth curve back much in the way figured in the M. bellicincta,
and far less sharply than in M. gracilis, tending back to the broad
band, in which they are much curved, and then forward again, leay-
ing an open angle of about 100°.

Any comparison with other allied species seems unnecessary, as,
except M. bellicincta, there is no American species likely to be
confounded with it. Pleurotomaria inflata, McCoy, Silurian fossils,
Ireland, is a kindred species, but quite distinct.

It is found in tolerable plenty associated in the same slabs with
the M. bicincta, Orthoceras arcuoliratum, Cyrtoceras Billings, and
Strophomena planumbona, at Allumette Islands. Hall’s specimens
were found at the junction of the Birdseye and Trenton limestones
in the Mohawk valley.

CYCLONEMA, TROCHONEMA, EUNEMA.
Decade I. Plate VI.
CYCLONEMA, Hall.

Cyclonema, Hall. Mollusca Gasteropoda. Family Litorinide.
Turbinate, thin, of few ventricose whorls, with concentric striz

* It is with some doubt this is referred to Hall’s very imperfect figured specimen.
His description however agrees accurately, and it is useless to multiply names.

24 CANADIAN FOSSILS.

or ridges, crossed by oblique, straight (or very slightly sinuous)
lines of growth. No umbilicus. The mouth rounded, and with
an imperfect peritreme. Inner lip thin, closely reflected, and
a little concave.

TROCHONEMA, Salter.

Trochonema.—Mollusea Gasteropoda. Family Litorinide. Turbi-
nate, thin, of few angular whorls, marked by strong concentric
ridges, and crossed by very oblique lines of growth. Umbilicus
wide, open. Inner lip thin, scarcely reflected; peritreme com-
plete.

Eunema, Salter.

Eunema.—Mollusca Gasteropoda. Family Litorinide. Turbinate
thin, of few angular whorls, marked by strong concentric ridges,
and crossed by strongly sinuate, prominent, and thread-like lines
of growth. Inner lip not reflected; peritreme simple; mouth
rather effuse below ; no umbilicus.

Loxonema, Phillips.

Lozxonema.—Mollusca Gasteropoda. Family Pyramidellida. Elon-
gated, many-whorled; aperture simple, attenuated above, effuse
below; lines of growth (marking the form of the outer lip)
sigmoidal ; no umbilicus.

The characters of these four genera which have been figured
together are here given in order to shew in what points they differ,
and what analogy and gradation of form subsists between them.

Taking Trochonema as the most depressed and widely umbilicate
form, or with simple and very oblique lines of growth, the next
step would appear to be Cyclonema or Holopea, in which the umbili-
cus is closed, and the lines of growth a little sigmoid, or at least
sinuate, below. Evunema is still more elongate, and the lines of
growth decidedly sigmoid; while it is difficult to say if E. pagoda
more properly belongs to this genus or to Lozonema, in which the
edge of the outer lip, indicated by the lines of growth, is sigmoid,
and the entire form elongated.

CANADIAN FOSSILS. 25 ©

Yet notwithstanding this apparent passage established by such
forms as Eunema, it is probable that Lozonema belongs to an entirely
different family (the Pyramidellide), and that the rest are thin-shelled
forms of Litorinide, with an evident tendency towards the fragile
Tanthina, with which the rudimentary sinus in the outer lip also
helps to connect them.

Professor Forbes thought Holopea (and therefore Cyclonema, which
is closely allied,) much like Litiopa, a pelagic form of the Litorinda,
and they both have the concave inner lip of Litorina. There is
some difficulty in determining the nearest recent analogue of
Trochonema. It may be compared with Skenea (Lutorinide) or with
Adeorbis (i. e., Cyclostrema), which differs from the other Trochide
in its non-nacreous shell. Eunema, it is true, has the sinus of the
outer lip so much increased as to separate it from any recent forms
of Litorinide, while it much resembles Janthina or the allied genera
Recluzia, which has an an extremely simple, paludiniform shell.
It has a much thicker shell, however, than these, and its affinities
are with the fossil genera above described, from which the elongate
form and sinuous outer lip effectually distinguish it.

The fossil shells under consideration appear to be all too solid for
comparison with floating shells, and the tendency they exhibit to
form projecting and irregular apertures in old age indicates rather a
ground-feeding and ultimately sedentary habit.

CYCLONEMA.

With regard to the limits between Holopea and Cyclonema, not
much that is satisfactory can be said. The form is similar, and the
strize or ribs are not always present in the one or absent in the other.
The possession of a concave reflected inner lip, if it could be estab-
lished for Cyclonema, would be a good character, yet certain species
in the Canadian collection which are quite smooth, and have the
general character of Holopea, resemble Cyclonema in this, though they
want the characteristic sculpture. Holopea seems to be sometimes
(H. obliqua, Hall,) umbilicate, and sometimes not so. Cyclonema is
never umbilicate, and the inner lip is concave in the type species.

If accepted as a genus, Cyclonema should include all those Silurian
species hitherto referred to Turbo, Ewomphalus, etc., which have
concentric ridges and oblique lines of growth. Although this is only _
a superficial character, it is found in so many species, that, combined —
with the thin shell, it may be taken into account. ;

26 CANADIAN FOSSILS.

Euomphalus granulatus and E. lineatus, Portlock, Turbo crebristria,
McCoy*, and T. sulcifer of Eichwald, in addition to those described
by Hall, will certainly fall into it. These, with numerous concentric
ribs, none of which are specially prominent, lead the way easily to
such forms as 7’. rupestris, Eichwald, in which most of the ridges are
suppressed, and a few large ones only remain. The bands of color
follow the direction of the ridges in the last named elegant species.

T. trimarginatus, Eichwald, is another similar form. It is difficult,
if not impossible, to draw the line between such species as these and
the several gradations which lead back to C. bilix or the fossil here
figured. The group appears to range into the Devonian rocks, as
we learn from the figures of the MM. Sandberger of Nassau.

C. Haryana, N. sp.
Plate VI. Figure 1.

C. turbinata, ventricosa, anfractibus 5 rotundatis, supra paullulum plana-
tis,—ultimo ad basin gibboso, striis que concentricis undulatis cincto 5
basi subangulaté levi; ore rotundo.

It is not difficult to distinguish this from the C. bilix ( Pleurotomaria
bilix, Conrad), for the whorls are much rounder and the spire conse-
quently not nearly so conical; the striae only cover a part of the
whorl, and the pillar-lip is not so straight or so much reflected.
The species are however very closely allied.

The whorls are rounded, and even rather gibbous toward the lower
part, but there is a decided flattening above, and the base too is a
little flattened (not nearly so much as in C. bilix). The lines of
growth are oblique backwards, as far as the basal angle, if it may
be so termed, and thence tur forward, making a slight sinus.
[This character is even more decided in the C. biliz, and is greatly
exaggerated in the genus Ewnema.]

The suture is well pronounced, the upper part of the whorl free
from concentric striz, which occur only on the sides; the base also
is smooth. The mouth is roundish, a little prominent only beneath
the columellar lip, which is not quite vertical, nor is the inner lip
much reflected or more than slightly concave.

Locality.— Pauquette’s Rapids.

* Paleozoic Fossils, Woodwardian Museum, Cambridge, Plate 1 L, figure 22.

CANADIAN FOSSILS. 27
C. SEMICARINATA, N. sp.
Figure 2.

C. semiuncralis, spird regularier conicd, nist suturis horizontalibus insecté ;
strus obscuris; anfractibus 4—5 supra brangulatis, infra 6—carinatis,
caring secundd maxima mediand, quartd prominuld ; ore rotundo.

Of this well-marked form there are only two or three specimens,
the largest not above half an inch in height. They were first taken
for Pleurotomaria percarinata, Hall, which, as it shews nothing of the
characteristic band or notch, may very probably belong to Cyclonema.
But in that species the sutural space is not horizontal, and the
conical spire seems therefore blunt instead of deeply incised, while
the keels below the chief ridge are mostly equal.

There are two or three other species in the Ottawa limestone, one
beautifully ornamented, and like a Plewrotomaria in everything except
the notch.

Locality.—Allumette Islands. Holopea obliqua, Hall, accompanies
it.

TROCHONEMA.

Under this proposed name will fail several Upper and Lower
Silurian species, such as the Turbo trochleatus of McCoy, and Euom-
phalus tricinctus of the same author; only those however with the
strong concentric ridges possess a wide umbilicus. Inachus angulatus,
Hisinger, is probably an extreme form of the group, with a greatly
depressed spire. Pleurotomaria umbilicata, Hall, is the one here
described, and the type of the genus.

T. UMBILICATA, Hall.
Plate VI. Figure 3.

Troch. unciam lata, depressa ; anfractibus perangulatis, facie externd latd
verticalr ; umbilico latissimo, tumido, carind obtusd permarginato.

Prof. Hall, Palenotology of New York, vol. i., plate 10, fig. 9, and
pl. 38, fig. 1; p. 43-175.

Turbinate, depressed, the last whorl often free; the spire short, truly
conical, interrupted only by the vertical faces of the whorls and the
hollow sutural edge. Volutions, 4 or 5, with 4 carinze, of which two

28 CANADIAN FOSSILS.

on the middle of the whorl are strong. prominent angles, enclosing
a broad, vertical, slightly concave space (the upper angle rather the
more prom‘nent); one close to the deeply canaliculated suture; the
fourth only visible on the base, margining a very broad umbilicus.

The space between the upper and second carina is more concave
than that below the latter, while between the third and fourth the
space is a little convex, not quite flat. The umbilicus is first concave
and then tumid; it exposes the second and part of the third whorl.
The mouth is round-ovate—the obliquity from above outwards—
and thickened at the basal angle formed by the lowest keel.

Hall’s specimens are afl more or less distorted and compressed ;
hence his description, though accurate, does not fully agree in all
points. The character of the angular volutions, with the concave
spaces between short depressed spire and wide umbilicus, enables us
to recognize the species ; and I am further assured by Mr. E. Billings
that there is no doubt of their identity. But the species must be
more variable than the Canadian specimens shew, since Hall figures
and describes forms (plate 38, figure 1g) more elevated, and others
(plate 38, figure Le, and plate 10, figure 94) more depressed than any
of ours. The base of none of his specimens is ventricose, and I think
that must be due to oblique pressure in his specimens or to their
being mostly internal casts.

The description, by Prof. McCoy, of his Turbo trochleatus* agrees
well with ours, except in the rounded base and small umbilicus ; it
has a less deep suture, as his figure shews, and the space between
the two bands on the whorl is decidedly narrower. These differences
are here noted particularly, as I had provisionally referred the
Canadian shell (see Reports British Association, preface) to the T.
trochleatus, McCoy. Now that we know the position of the Galway
rocks as Middle Silurian, it is the less likely that any species should
be in common with those of the lowest formations of Canada.

Pleurotomaria latifusciata, of the same author, is another species so
like ours, that it seems hardly distinguishable, except by the longer
spire.

Locality —T. umbilicata is a common species occurring in nearly
all the slabs from Pauquette’s Rapids. It ranges from the Birdseye
to the Trenton limestones, in New York.

* Silurian Fossils, Ireland, plate i., figure 9.

CANADIAN FOSSILS. 29

EUNEMA.

The typical species may be considered E. strigillata, which has an
elongate form, and the strize bent forwards below the sinus; while
there are others with the lines of growth vertical below, or searcely
at all brought forward. These latter connect it with the Cyclonema,
but have still the produced mouth and more turrited form, which
gives them the aspect of Murchasonia. >

E. STRIGILLATA, N. sp.
Plate VI. Figure 4.

E. turbinata, elongata, anfractibus 6 obliquis, sepe vagis: carinis tribus
equidistantibus, superior ad suturam, secunda supra medium positas ;
cunctis &@ striis asperis dichotomisque decussatis ; ore ovato.

This beautiful shell is quite abundant at Pauquette’s Rapids, and
many finely-weithered specimens shew the characters well. It is a
thin shell, and the striations of the surface are remarkably sharp,
prominent, and regular.

Shell elongate, turbinate, of about six rather oblique whorls, the
last sometimes free. There are three prominent ridges on each
whorl, the principal one placed much above the middle of the body-
whorl, the upper one near the suture, the lower at an equal distance
below the median keel. All are crossed by equal, sharp, close,
thread-like ridges of growth, which tend about 60° backward to the
principal keel, where they are sharply bent, and proceed a little
forwards over the sides and base; the open angle of the notch so
formed is about 130°. They bifurcate regularly between the upper
and middle keel, and re-unite in pairs upon the base, which is
produced. The mouth is oval, a little pointed above, and below
somewhat effuse. There is no umbilicus, and the inner lip is not
reflected or pressed closely against the columellar base, which has
a slight angle upon it.

Locality.— Pauquette’s Rapids.

30 CANADIAN FOSSILS.

E? pacopa, N. sp.
Plate VIX Figure 5.

E. turrita, elongatissima, anfractibus 10-11 depressis tricarinatis ; carind
superiore remotd minima, suturam profundam approximatéd ; mediand
inferiorique fere equalibus, eminentibus : cunctis crenulatis, striis
obscuris (retrorsis? ).

A much elongated, turrited shell, of about ten or eleven very convex
beaded whorls, very gradually increasing in size, and furnished each
with two prominent keels, besides a smaller one along the sutural
edge. Of the principal keels the upper is rather the more prominent,
and placed about the middle of the whorls in the spire, but above it
on the body-whorl. _ The space above it is a regular slope, between
it and the third keel concave, and below the third also concave for a
somewhat greater space as far as a fourth, which only shews on the
base of the body-whorl, being covered by the suture in the spire
Mouth, unknown.

The keels are all more or less crenulated, evidently by the lines of
growth, but these are so obscure that it is impossible to say whether
they are oblique backwards, as in Eunema, or arched forward, as in
true Loxonema. The species might be referred to either of the two
genera, but as yet we know of no Loxonema with strong spiral keels,
while they are characteristic of Eunema; it is therefore safest to leave
it in the present genus, especially as there are other smaller species
not described here, of quite as elongate a form, in which the course
of the lines of growth is not doubtful.

Locality—F requent on slabs of limestone, in company with many
of the foregoing species, at Pauquette’s Rapids. Another new spe-
cies resembles a small Cerithiwm, and might be termed E. cerithioides.

Loxonema, Phillips.

The species of this genus are but rare in Lower Silurian rocks,
One is introduced here to compare with the most extreme forms of
Eunema. The inner lip is still more incomplete, and the curve of

the strize more sigmoidal.

CANADIAN FOSSILS. 31
L. Murrayana, N. sp.

Plate VI. Figure 6.

DL. 23 uncias longa, anfractibus regulariter convexis etiam inflatis, ne
supra planulatis, (ad suturam vallo angusto notatis,) striis concentricis
obscuris, striis incrementt conspicuis, antrorsum arcuatis: umbilico
nullo; ore obovato.

The length of this species must have been full two and a half
inches, and the diameter of the lower whorl not less than three
quarters of aninch. The whorls are very convex, almost inflated, and
have no special prominence in any part ; their base isa little produced.
The sutural edge is a fine raised thread, and beneath it occurs a
narrow flattened space (with a raised border on the lowest whor)).
There are a few faint concentric striz, but the lines of growth are
the only prominent ones; they are strong, sigmoid, the backward
curve short, the lower forward one a broad arch, reaching further
forward than their origin at the suture. There is only a minute
umbilical depression, with no bounding ridge, and the inner lip is
incomplete, its edge simple, not reflected.

A single specimen only has occurred of this fine shell, and I have
pleasure in naming it after Mr. Alexander Murray, who has labored
so long in the Canadian Survey.

Locality.—Pauquette’s Rapids. Murchisonia (Loxonema ?) subfusi-
ormis, Hall, appears also to occur in this limestone.

Cyrtoceras, Goldfuss.

Generic characters.—Cyrtoceras, Goldfuss. Shell curved or partially
involute, sometimes with the transverse, at others the longitu-
dinal, diameter the greater. Aperture often contracted (in the
smooth forms). Siphuncle subinternal, central, or external.
(Barrande.)

Section Cyrtoceras—Curved ; siphuncle variable in position, simple,

Gyroceras:—Involute ; siphon internal or subcentral, solid,
radiated.

It is not easy, in the absence of a perfect structure in the siphuncle,
to separate Cyrtoceras from Gyroceras, the principal difference being
the more regularly involute form and ornamented surface in the
latter (just as in the case of Tozoceras and Crioceras among the
genera with foliated septa).

32 CANADIAN FOSSILS.

Indeed it is much to be wished that a name so ill applied as
Gyroceras should be abolished altogether. Originally given by
Meyer to the Spirula compressa of Von Buch, which has since proved
to be a Goniatites, M. d’Orbigny had no warrant for applying the
name to a totally different form. And as the position of the siphon
will not distinguish the two genera, there remains but the somewhat
obscure character of its more solid radiated structure to separate the
two genera. It would be better to reunite them, and when the
value of this character is better known, to complete the classification.

We are fortunately able to present two extreme forms of the genus
in one plate: the one smooth on the surface and much laterally
compressed, as in the several Silurian forms; the other ornamented
with large, frill-like varices of growth, and with a wide section, like
those of the Devonian species. Some of these latter (referred to
Cyrtoceras by Goldfuss and Pbillips,) are as much involute as a
Tutuites, and are wide in section, the fore and aft diameter, so to
speak, being less than the tranverse measure.

CYRTOCERAS FALX.
Decade I. Plate VII. Figure 1-4.

Synonym.—C. fulz, Billings. Report of Progress, Geological Survey
of Canada, 1857, p. 314.

A smooth shell, or with very faint and nearly direct lines of
growth. It is strongly curved, and somewhat compressed, about
two inches long, rapidly tapering from ten lines broad to two and
a half, and in some specimens more quickly. Aperture oval, ten
lines broad by eight thick. Siphon nearly close to the peripheral
margin. Septa close, concave from back to front.

I have Mr. Billings’ own authority for identifying this shell with the
species described by him, else E should have regarded it as rather
belonging to the other allied species (from the same locality) which
he has termed C. szmpler. As the specimen figured—and others
still more perfect—are in the Canadian Museum—I beg to refer to
his description in the Report of Progress of the Geological Survey,
published 1857, pp. 313, 314,) for the specific characters. It might
be compared with C. macrostomum, C. arcuatum, and C.camurum, Hall,
but all have more distant septa.

Locality.—Pauquette’s Rapids.

CANADIAN FOSSILS. 33

C. BILLINGSIL.
Plate VII. Figures 5, 6.

C. 2-3 unciale, in guventute subcylindricum involutum, in etate depresso-
ovale, rectius ; annulis remotioribus elevatis undulatis in dorso sinuatis ;
septis approximatis planis, suphunculo externo; suum diametrum a
margine remoto.

Synonym.—C. lamellosum, Hall, Paleontology of New York, vol. i.,
plate 41, figure 2 (not of DeVerneuil and D’Archiac).

Prof. Hall’s description, taken from a young and very imperfect
specimen, is clearly applicable; but this species must receive a new
name, since the C. lamellosum, a nearly allied species from the Eifel
limestone, differs both in the less rate of increase in the whorl, and
the lamellz are much closer. The curve of the tube is also more
gentle. But for these proportional characters, which however are
quite sufficient in this genus, it would be difficult to separate the
Devonian species, which the Professor seems to have overlooked, as
he describes his fossil as new. I adopt such parts of his description
as are applicable to the adult form.

Subcylindrical when young, at a diameter of seven lines (and
regularly involute?), but soon attaining a more open curve and
becoming laterally expanded, the dorso-ventral diameter being to the
lateral as nine lines to thirteen, when this diameter is attained. The
tapering is more rapid in the young than in the adult portions.

The lamellae are rather coarse and somewhat irregular in distance.
(C. lamellosum has them very close and regular.) In figure 6 they are
not more than a third of a line apart in the young portion (a), and
less than a line distant in the older portion (6), while in figure 5
they are fully two lines apart in the same diameter, and become
closer again in the adult portion (b), where the distance is again not
more than a line or a line anda half.* Their course is direct over
the sides and inner margin, but on the outer (ventral) surface they
turn rapidly backward, forming a distinct sinus. They are rudely
fimbriated, with ‘transverse, undulating, squamose lamellz, abruptly
bent backwards on the dorsal line,” and several obscure, longitudinal
furrows cross them. ‘‘ The spaces between the lamelle are marked

_ * Such a change in the ornament is not unfrequent in the Cephalopoda, and indicates
probably a more vigorous growth in middle age.

Cc

34 CANADIAN FOSSILS.

by fine transverse striz.” Septa close (Hall), very flat. Siphunew —
small, its own diameter distant from the outer or ventral* border.

Of this elegant species only two examples have as yet occurred,
both of which are figured.

Locality—Allumette Islands. C. annulatum, Hall, is more rare.
Orthoceras arcuoliratum, O. bilineatum, and O. laqueatum, are also found,
the first very common indeed; and the Gonioceras anceps of the
Black-river limestone occurs with these. (See Preface.)

CTENODONTA, Salter.

Ctenodonta, Salter, 1851. Mollusca Lamellibranchiata. Family,
Arcacide. Nearly equilateral, generally transverse, anterior
side largest ; beaks, approximate, not prominent; hinge-line
with a double series of bent teeth, connected by smaller ones
beneath the beak; ligament posterior, external, on a fulerum:
no striated area or cartilage pit; muscular impressions strong
(with supplementary scars), not bounded by elevated ridges;
pallial line simple.

I was not aware, when I proposed the above generic term for a group
of palzozoic Nucule?, that the principal species had been previously
published under the name of Tellinomya by Prof. Hall. His recent
descriptions{ shew this to have been the case, and if the name did
not convey an entirely erroneous view of the affinities, I should have
been glad to restore it. But the chief characters of the genus reside
in the hinge and teeth, which are neither figured nor described by
him, casts only of the interior and the external surface having been
given in the plates of his excellent work, nor was the external
ligament observed.

Mr. S. P. Woodward, in his most able treatise on the Mollusca, has
included my proposed genus under fsoarca of Munster, a group of
nuculoid shells which have the peculiarity of Ctenodonta so far as the
external ligament is concerned. But in Isoarca there is a ligamental
area, aS in Arca and Cucull@a, and the tumid beaks are remote,

* The outer margin is often called dorsal, but there is an objection to using terms in
direct contradiction to the anatomical structure.

} Reports British Association, 1851. Trans. Sect., p. 63.

} Descriptions of New Paleozoic Fossils; extracted from the Reports of the Regents
of the University, Albany, 1856, p. 142.

CANADIAN FOSSILS. 35

subspiral, and in the typical species (I. cordiformis, Schibler, and
I. subspirata, Munster,) quite toward one side. It may be doubtful
if such species as I. lineata of Munster and Nucula elliptica of Goldfuss;
which have subcentral beaks, do not belong to Ctenodonta ; they are
smooth, or with a concentric lineation only, while Isoarca is often
cancellate.

Solenella, Sowerby, has an external ligament like Ctenodonta, but a
notched pallial line.

The genus has been referred to in the third edition of “ Siluria,”
p- 213, 859. It will include, as I believe, all the Silurian Nucule,
and a considerable number of the other Palaeozoic species. It pro-
bably extends, as above stated, into the Tvvas.

C. NASUTA.

Plate VIII: Figures 1, 2.

C. biuncialis et ultra, transverso-ovata, levis, nisi anticé rugis concentricis ;
latere antico rotundato, postico subcontracto elongato, haud carinato ;
umbonibus depressis.

Synonym.— Tellinomya nasuta, Hall, Paleontology New York, vol. i.,
plate 34, figure 3. Ctenodonta Logani, Salter, in British Asso-
ciation Reports, 1851. Trans. Sect., page 63. Isoarca Logani,
Woodward, Manual Shells, page 269. Tellinomya nasuta, Hall,
Report of the Regents of the University, Albany, 1857, p- 148,
fig. 1-3.

A beautiful species, not unlike in shape to some species of Anatina
or Thracia, and, from the subcentral position of the beaks, very
unlike the usual appearance of Nucula.

It is the largest known species of the genus, full two and a half
inches wide, by one inch and a quarter long, measuring from the
slightly prominent beaks, which are much nearer the anterior than
the siphonal end. The depth of the valves, united, comprises three
fourths of an inch.

The general contour is transversely ovate. The anterior side
perfectly rounded and marked with concentric ruge, which are
strongest on the upper portion. The posterior side narrows consi-
derably, and is a little contracted at the posterior third; its surface
is smooth and gradually less convex towards the subtruncated end ;

36 CANADIAN FOSSILS.

the posterior slope or ridge only excepted, which is convex, but not
at all carinate. There is a slight groove below the straight cardinal
border.

The ligament fulcrum extends to full half an inch from the beak,
and the ligament itself (often perfectly preserved in the silex) is
convex, and rather conspicuous. The teeth are straight, vertical, and
set on a moderately broad edge; there are about eleven or twelve on
each side, arranged nearly in a direct line; the hinge-plate which
bears them is narrowest on the anterior side, and beneath the beak
much contracted in depth. (In the next species it is considerably
broader. ‘

Locality. Allumetite Islands. A new species of Lyrodesma occurs
with it, distinct from L. plana of the Trenton limestone.

C. Logant.
Plate VIII. Figure 3.

C. uncialis, convera, anticé rotundata fere gibba, posticé subtruncata obtusi-
carinata; umbone subcentrali eminente; dentibus anticis 7, posticis 9
curvatis.

Synonym.— Tellinomya dubia, Hall, Report Regents University, pl. c,
figures 4,5 (not of Pal. New York, plate 34, vol. tee

An elegant species, which might, till closely examined, pass for a
variety of the last. It is much more convex, and almost gibbous
anteriorly: the posterior side more decidedly contracted and sub-
carinate above. The beak is rounded, but elevated and placed
centrally, or rather nearer to the subtruncate posterior end than the
other. There is no lunette.

The teeth are placed on a gently curved hinge-plate, which is not
indented by so prominent a ligament fulcrum as in the other species.
Those on the anterior side are straight, prominent, and simple; the
posterior ones are bent towards the centre, and those beneath the
beak crowded, no space being left between the anterior and posterior
sets.

The anterior shews that the adductor impressions were not so deep
as in the next described and smaller species.

As the larger fossil above described cannot bear the name I had
originally proposed, and as the name Ctenodonta Logani has appeared

CANADIAN FOSSILS. 37

in print, I wish to apply it to this fine species. Professor Hall has
figured it under the name dubia, but the figures given in his
Paleontology of New York, plate 34, shew that species to have been
smaller and wider, the “length almost twice the height.” It is
much more gibbous too, according to his figures, the edge being
turned quite abruptly inward. Mr. Billings, who has seen specimens
of the C. dubia, assures me they are distinct.

Locality—With the last. Rare.

C. CONTRACTA.
Plate VIII. Figures 4, 5.

C. parvula, tres partes unci@ lata, trigonula, subequilatera, anticé rotundata,
posticé cuneata carinata contracta, umbonibus elevatis pre medium
positis ; lunulé distinctd ; cardine dentibus majoribus.

Synonym.— Tellinomya cuneata, Hall, Report, |. c., figures 6, 7.

A common but pretty little species, which well illustrates the
character of the genus as distinct from Nucula or Leda, to either of
which it bears a strong resemblance. Instead of two rows of teeth
separated by a spoon-shaped process to carry the ligament, the two
rows run into each other, with only a slight angular notch to
separate them, and the ligament is clearly seen outside, set on its
prominent fulcrum.

The form is that of a wide triangle, with the gently elevated beak
rather nearer the anterior end. This is rounded into the ventral
border, which has its greatest convexity in advance of the line of the
beak. The shell too is most convex here, and a depressed line
separates the elevated and carinate siphonal ridge. The posterior
cardinal slope is flat in some specimens, and nearly so in all; the
ligament fulcra marked out on it asa long oval lunette extending
half-way along it. A similar lunette, more deeply sunken, marks the
anterior side. The ligament itself is but small.

Teeth about six or seven on each side; beneath the beak a few
crowded ones occur; they are straight, or nearly so, and set obliquely
inwards on both sides of the broad, bent hinge-plate. The beak
considerably overhangs the hinge (fig. 5a).

The shell is thick, the impressions of the adductor muscles deep,
and close under the hinge-line. A small accessory scar occurs above

38 CANADIAN FOSSILS.

each impression. A thickened ridge lies on the inner side of each,
strongest behind the straight-edged anterior impression.

Fig. 4 shews the variety with the flat or vertical posterior slope ;
fig. 5 has it slightly convex.

Locality.—Plentiful in the Allumette limestones.

C. GIBBERULA, N. sp.
Plate VIII. Figure 6.

C. subtrigona, rudis, 9 lineas lata, margine antico cardinali gibbo ; latere
antico magno, convexo, lunuld nulla ; postico brevi subcarinato ; cardine
dentibus modicis.

Differs from the last by characters not very obvious at first sight,
but these grow more evident by study, and it seems to bear the same
relation to C. contracta that the C. obtusa does to C. Logani. The form
is trapezoidal rather than triangular, and of unequal sides; the
posterior bluntly pointed and small; the anterior large, gibbous and -
rounded ; the ventral margin almost straight. The beak is conside-
rably nearer the posterior side. It is not very prominent, the valves
being most convex all along the anterior slope which overhangs the
hinge-margin all along; the sinus which separates the somewhat
pointed posterior side falls under the beak, and consequently near to
that margin; and the posterior slope is bluntly carinate, and so short
as to be not far from vertical. The ligament fulcra are marked out
by a narrow lunette, which the beak overhangs.

The hinge-plate is bent at an obtuse angle, and bears about ten
teeth on each side, which are set obliquely, as in the last species.
The shell is thick, but the muscular impressions are scarcely visible
in our specimens. A few antiquated lines of growth near the margin
shew that our specimen is full-grown.

Notwithstanding the above important differences, there is much
similarity to the last species in habit, the distinction being chiefly
due to the exaggerated development of the anterior side.

Lo-cality.—Not uncommon in the Allumette limestone.

CANADIAN FOSSILS. 39
C. ASTARTEZFORMIS, N. sp.

Plate VIII. Figure 7.

C. crassa, viz semipollicaris, trigona, nate curvo, excelso : margine postico
lente concavo, reliquis convexis ; superficie liners crebrissimis rugisque
concentricis ornatd: dentibus pluribus, fractis.

A small, thick shell, higher than wide, triangular, with a greatly
elevated and somewhat curved beak, and the surface covered with
fine equal concentric striz, besides four or five rugz or varices of
growth. The posterior side (at least we must suppose this to be the
posterior side from analogy with other species of Nucula,—the beak
is however extravagantly raised ;) is gently concave without a dis-
tinct lunette, the posterior and ventral margins arched; the whole
figure is triangular.

The interior shews a flat hinge-plate, broadest beneath the beak;
but with no cavity for a ligament, which must therefore have been
external, though no fulcra are visible. The teeth are numerous and
V-shaped, extending far down the posterior hinge-plate, and half-way
down the anterior side. They are either absent or very small imme-
diately under the beak.

This beautiful species exactly resembles at first sight one common
in the Lower Silurian rocks of Wales, the C. (Nuc.) varicosa, Salter,
and it is difficult to say how they differ. But while the Canadian
fossil is a solid shell, the British species is a very thin one, and it is
the interior cast of the one that resembles the outside of the other.

Locality.—Allumette Islands.

ORTHIS TRICENARIA, Conrad.
Decade I. Plate 9.

Genus Orthis, Dalman. Mollusca Brachiopoda. Family Orthide.
Shell punctate, squarish, rounded, or transversely oblong (the
hinge-line generally narrower than the shell), radiately striated
or plaited, convex in one or both valves; hinge-line with a
fissure open in both valves*; dorsal valve with divergent short
teeth, and a simple cardinal process between them; muscular
impressions roundish, and circumscribed in the dorsal valve.

* In Orthisina and Streptorhynchus the fissures are closed. These are regarded as
subgenera of Orthis by some authors.

40 CANADIAN FOSSILS.

Specific character.—O. rotundata pollicaris, valvd dorsali pland, ventral
gibbd cardine, in latitudine testam @quante ; ared magna subcurvé ;
foramine angustissimo. Coste radiantes convexe, circiter 30, interstitris
angustissimis in valvd dorsali scepe filiferis ; strus transversis incon-
spicuis.

Synonym.— O. tricenaria, Conrad, 1843. Proc. Acad. Nat. Hist. Soc.,
vol. i., p. 333. Hall’s Pal. New York, vol. i., p. 121, plate 32,
figure &.

There could scarcely be better examples of specific character, as
distinguished from mere variability, than are exhibited by four shells,
two American and two British, among the large plaited Orthides of
the Lower Silurian rocks. Of these, Orthis tricenaria, the subject of our
plate, is precisely analogous to the English form, O. actonie, Sowerby,
while O. pectinella, of Conrad, another American species, with nume-
rous varieties, equally well represents the O. flabellulum of Snowdon.

Yet while all these species so much resemble one another that they
might easily be confounded, each is distinguished by characters as neat
as they are constant. O. Actonia, Siluria, 3d edition, p. 209, fig. 32,
has few strong angular plaits, frequently bi- or tri-furcate at their
ends, and the ventral or receiving valve is the convex one, the dorsal
being concave. In O. flabell/ulum the reverse takes place, or the larger
ventral valve, although prominent at the beak, being much flattened
and actually concave, while the convex valve is the dorsal one.
This difference is constant, while the fewness of the ribs in both
distinguish them from the variable O. calligramma of Dalman, which _
has both valves gently and equally convex.

The same relative differences are observable in the two American
species above quoted. O. tricenaria has the ventral valve the large
one, and the other flat or even concave, while O. pectinella possesses
a well-defined convex dorsal valve and a concave ventral valve, the
beak of which is nevertheless prominent, as it is in O. flabellulum.
Both again are distinct from the O. plicatella, which represents in
America the O. calligramma of Europe, and, like it, has both valves
convex.

O. tricenaria is of a semi-oval or even subtrigonal form when
young, and in age is subquadrate, from the greater extension of the
front than the sides, with length and breadth very nearly equal.
Dorsal valve (fig 1), flat, concave at the beak, its hinge-line straight,
produced into very short ears; ventral valve (fig. 2), strongly convex,
even gibbous, its beak much elevated, but not at all incurved ;

CANADIAN FOSSILS. 41

area oblique, broad-triangular (about 140°); foramen almost linear,
continued quite to the apex.

Surface of both valves closely radiated by about thirty convex;
rod-like ribs, with narrower interstices, the ribs quite simple in the
ventral valve, but interlined in the upper or dorsal valve by fine
regular threads. All are crossed by delicate, inconspicuous striz of
growth. Old specimens are antiquated near the margin. The shell is
thin; the interior is deeply scored, for some distance from the margin,
by conspicuous furrows between the ribs; each rib is impressed by
a median groove.

The space for the muscular impressions in the ventral valve
(fig. 3a), is moderately large, rhomboidal, bilobed at the base, cir-
cumseribed by external blunt ridges, and divided by a very slight
median one. The hinge-plates are very short, and diverge at about
80°. The ovarian spaces (}) are well marked.

The interior of the dorsal valve (fig. 4), with the muscular impres-
sions very strongly marked (8, c), shews them divided by a broad,
rounded ridge. The brachial processes or hinge-teeth (a) are very
short, diverging at 50°, and with a linear central tooth (cardinal
process), which bisects the narrow foramen, and bends backward
with the area. The ribs shew very strongly in the interior, fully
half-way up the shell.

The area in the dorsal valve is flat, and forms an angle of 50° with
the valve itself: that of the ventral valve is inclined at about 70° ;
it is very little curved. The two areze meet at about 120° in the
young shell, and about 90° to 100° in the adult.

A great advance was made in the classification of the Brachiopoda
by Dalman, when he established the genera Orthis and Lepteena for
the numerous Silurian species he was acquainted with. And little
has since been done for the family of the Orthide, except the sub-
division of the former genus, and the separation from both of the
flat, semicircular forms now known under the name of Strophomena.
The three genera are clearly separable, if account be taken of the
general habit, as well as of the characters of the hinge and muscular
impressions, for while Leptena has the valves involute, and the
muscular impressions of the entering valve greatly elongated,
Strophomena and Orthis have these four impressions subquadrate and
arranged in a circumscribed group, Strophomena being further distin-
guished from Orthis no less by its expanded flat form, than by the
large bilobed cardinal process between the teeth in the dorsal valve.
In Orthis the process is simple, often linear, and the two teeth

42 CANADIAN FOSSILS.

divergent at a much less angle. The hinge-line of Orthis is variable
in width, often considerably less than that of the shell. In Stro-
phomena it is always as wide as the widest part of it. Orthis has
generally one, sometimes both valves convex. Strophomena has
both valves flattened, and generally one bent over the other. And
while the impressions of the blood-vessels in the mantle of Orthzs are
radiating and but little curved upwards on the sides, those of
Strophomena take a wide upward bend, and quite encircle the ovarian
spaces.

The range of the three genera, thus defined, is somewhat different.
Orthis is the earliest, beginning in the period of the Lingula flags,
and reaching upwards by one or other of its subgenera to the
Permian rocks. Leptena began not quite so early, in the Llandeilo
flags, but maintained its position till the Oolitic period; while
Strophomena, more restricted than either, commenced apparently at
the same period with Leptena, but is not known later than the
Devonian epoch. Some authors of repute (M‘Coy, Woodward, etc.,)
regard Strophomena and Leptena as mere subgenera, but I prefer,
as Mr. Thomas Davidson has done, to give them each generic rank.

The separation of the four subgenera,—Orthis (Dalman), Orthisina
(D’Orbigny), Streptorhynchus and Platystrophia of King, is quite
convenient, and of geological value. The range of the true Orthis
is the most extensive, and the possession of an open triangular
foramen in one or both valves, distinguishes it from Orthisina, a
Lower Silurian form. In this both valves have a closed deltidium,
a small circular hole only being left in the apex of the larger valve.
Platystrophia, which has the form of a Spirifer, and an open foramen
in both valves, is Silurian only, while Streptorhynchus, (which, in the
form of the teeth and hinge-plates) is most like Orthisena, has a wide
area, and is attached by the twisted beak. It is an irregular form,
characteristic of the Carboniferous and Permian strata.

Locality.—Pauquette’s Rapids, in tolerable plenty, with Stropho-
mena planumbona and S. filitexta (S. alternata seems to be absent),
Rhynchonella increbescens and Pentamerus (atrypa) hemiplicatus of Hall
are here. They are both Trenton fossils, and there are one or two
other species of Rhynchonella and of Orthis, of smaller size.

CANADIAN FOSSILS. 43

RECEPTACULITES.
Decade I. Plate 10.

Generic character.—Receptaculites, Defrance. Sub-kingdom Protozoa.
- Order Foraminifera. Family Orbitolitide. An infundibuli-
form disk, composed of vertical cells in a single series, having
rhomboidal thickened apices at each extremity: the casts of
these cells within are thick cylindrical columns (of sarcode)
connected by transverse stolons at their upper and lower ends ;
and by smaller ones in the middle of the columns.

The clearing up of the affinities of a single doubtful fossil is never
barren of good results, since it may tend to throw light on other
forms as little understood, as well as upon the conditions under
which the organisms lived and were imbedded. And if, as in the
present instance, it should be rendered probable that an extinct
form was of much greater size and importance than its living conge-
ners, the excessive development in earlier times of a type now
existing, is a fact quite as significant in its bearing on the history of
organic life on the globe as the absolute replacement of one group by
another in geological time.

The genus Receptaculites has long been known, having been
described and figured by Defrance so early as 1827, and quoted by
De Blainville from the Devonian rocks of Belgium. It is known in
the Silurian strata of Australia and in the northern parts of the
American continent, but has not yet been detected in strata of that
age in Britain. .

It has been referred to plants, and doubtfully to corals, but still
remains where it was first placed, among the group of ‘“ Incertz Sedis.”
It does not seem to have occurred to naturalists* that a form fre-
quently five inches in diameter and not less than an inch in thickness
could be referable to the group of Foraminifera, and be allied not
very distantly to the genus Oréctolites. But the excellent figures and
elaborate descriptions by Dr. Carpenter of this group of the Forami-
nifera, and especially of some large species from Australia and the

* Except my friend Mr. T. R. Jones, who, some years back, perceived the analogy
in form, but neither he nor myself at that time took any further notice of it. I had
forgotten his observation when Dr. Carpenter’s memoir appeared. It is due to him to
recall it.

44 CANADIAN FOSSILS.

South Sea Islands, shew a great resemblance to our fossils, which
on closer study becomes more striking; and I am induced, notwith-
standing slight differences of structure, to regard Receptaculites as
belonging to the same family, and as having a greater resemblance
to the complex than to the more simple forms of the Orbitolitide.

Tt will be desirable first to shew what is the structure of Orbito-
lites, as given by Dr. Carpenter in his memoir, ‘Trans. Phil. Soc.,”
voiume for 1856. If the enlarged figure with vertical and horizontal
sections in his plate 5, fig. 6, be taken, as he intends them, to shew
the general structure of a compound Orbitolite, it will be seen that
the greater part of a vertical section through a disk is occupied by
the simple columnar cells which form the basis of the whole struc-
ture, and which are produced in successive rings around the globular
central chamber. The cells of one ring alternate with those of
the next, and form, when the superficial layer is removed, or as seen
in horizontal section, a quincunx arrangement of circular cavities.
Each ring of cells is connected with the next by small perforations
giving passage to the minute stolons of sarcode, and of these there
1s only one to each cell in the simple forms, but they are numerous
in the more complex varieties. Besides these small connecting stolons
which link together the cells of one circle with those of the next,
there are others, concentric ones of large size, which connect the
cells laterally, there being in the complex form an upper and a lower
great concentric stolon running along the top and the bottom of all
the columns. It is from these stolons that the superficial segments
take their rise, and not directly from the crown of the large cell itself.
In the simpler type there is no distinction into superficial and median
cells, nor any great concentric stolons above or below, the connect-
ing pores being placed about the middle of the large cells, which
are often bent in shape. (See figures 4, 5, 7, in plate 5 of Dr. Car-
penter’s paper.)

In the Orbitolites of the Paris basin there is not that clear separa-
tion of the superficial from the columnar cells which exists in the
other form ;—the upper or outer cells being in fact the upward or
downward continuation of the columns themselves, and only sepa-
rated from them by the large stolons before described. (See his
plate 6, figs. 10, 11.)

Receptaculites—In the possession of great columnar cells, with
large connecting stolons above and below, and with several smaller
ones on the sides of the columnar cells, our fossil agrees with the
complex forms described by Dr. Carpenter, but (as in the Parisian

CANADIAN FOSSILS. 45

Orbitolites), there are no superficial cells proper, although the cavity
has swelled out and been extended at the terminations of the columns
above and below, so as to give the appearance of a superficial stra-
tum. It will be seen by the description that this form most nearly
illustrates our fossil.

R. OCCIDENTALIS, N. sp.
Plate X. Figs. 1-7.

Synonym.—R. Neptunu? Hall, Paleontology of New York, vol. i.,
page 68, plate 24, figure 3.

Specific character.—R. magnus, 5-6, pollicaris, vix infundibulatus, crassus,
cellulis verticalibus rectis cylindricis, apicibus supra rotundatis convezis,
subter plams, rhombordeis granulatis.

Discoid, from four to six inches broad, and from half an inch to an’
inch in thickness; the limb gently convex above, but rather sud-
denly indented and cup-shaped in the middle, from which the rows
of cells radiate in curved lines, crossing like the engine-turned orna™
ment of a watch. The thickness of the disk near the centre is but
little, but this increases rapidly towards the margin, becoming in
some cases half an inch thick at twice that distance from the centre,
The cavities of the cells themselves (in the fossil filled up with silex)
are not above a line and a half broad in the largest specimens.
They are rhomboidal on the lower surface (figure 5); on the upper
(figure 3) they terminate in a convex boss and have wide openings
between, but are connected by four lateral processes with the
adjoining cells.

A cross section, as in the right-hand portion of fig. 1 (fig. 6c) shews
the columns round (a) and with interstices nearly equal to their own
diameter, and a lateral view (figure 6) shews the columns with their
bases (a) expanded, so as to leave but narrow linear interstices on
the lower surface*. Ata short distance above this they give birth
to four connecting processes or stolons (c), as above described.
The columns are thence cylindrical, and nearly their own diameter
apart. In one of the specimens there are several intermediate small
connecting stolons along the columns (figure 4a), and this is impor-
tant in comparing the fossil with the recent Orbitolites.

* Figures 1, 4, 5, 6, 7, are reversed, being placed upside down on the plate. Figures
2, 3, shew the upper surface of the cup.

46 CANADIAN FOSSILS.

The upper terminavion of the cells (fig. 6c) again expands, so as
to form broad and closely placed tesserze, with only small cavities:
between them. These were of course, if the fossil be a Foraminifer,
filled up with solid calcareous matter, now removed.

One character in particular which serves to connect the fossil
with its living analogue is the very considerable space occupied by
the animal matter—now solid spaces filled with silex—both on the
upper and lower surfaces.

It forms, as above noted, rhomboidal plates on the Jower surfaces,
which plates are somewhat imbricated; and the concavities within
them (not distinct cells, as in compound Orbitolites,) communicate
with each other at one or more of the angles (figure 7) very much in
the way shewn by a section of Orbitolites (see Carpenter, 1. ¢.,
plate 6, figs. 1, 2), while the intervening calcareous walls are linear
and thin. (Sometimes, as in R. australis, figs. 8, 9, these basal plates
are lobed.)

If, instead of comparing Receptaculites with the Orbitolites, we
should suppose it related to any of the millepore corals, or still more
probably to such a form as that of the purple organ-coral (Tubipora
musica), the reverse of all this would be the case. There should be
a calcareous plate or epitheca on the lower surface, from which the
tubular corallites would spring, and the walls of these latter, however
thin, ought to be visible in the transverse section, which we do not
find to be the case in slices of the columns viewed by transmitted
light. Again, the upper extremity of the tubes should be open, not
closed by convex plates as in the fossil, since such could only be the
case when the walls of the coral-cells were so greatly thickened as
nearly to close the mouth, while we have seen that in the fossil the
corresponding part expands, and is covered over by a definite and
often lobed plate, to all appearance continuous with the walls of
the cells.

If any analogy be suspected between Receptaculites and such
Palzeozoic corals as Halysites (the chain-coral), or with Syringopora,
there should, besides the characters above mentioned, be indications
of transverse plates which have never yet appeared.

I believe all this applies equally to the Receptaculites Neptuni of
the Devonian rocks of Belgium, but there is some appearance of a
thin investment of the columns in transverse sections of that species
which requires further investigation. And as it is of a deeply
infundibuliform shape, there is of course a possibility that it and the
other Receptaculites may be very regularly formed sponges; but I

CANADIAN FOSSILS. AT

have the greater satisfaction in the above view of the affinity,
because, on explaining the specimens to Dr. Carpenter, I found that
he entirely agreed in it. After pointing out several objections that
might be made, he shewed me that there was in nearly every point
a close coincidence in essential structure between Receptaculites |
and Orbitolites, the difference being only in the giant size of the
cells in this the most ancient of Foraminifera.

Locality—Plentiful in the limestone of Pauquette’s rapids. The
Corals and Crinoidea which accompany it are: Petraia (2 species),
Favosites lycopodites (?) or lycoperdon, with the Crinoid Schizocrinus
nodosus, and a species of Glyptocystites, the latter more rarely.

R. AUSTRALIS, N. sp.
Plate X. Figure 8-10.

Specific character.—R. magnus, expansus, cellulis verticalibus subcylindri-
cis incrassatis, apicibus subter convexis, lobulatis.

Under this name a curious species of the genus is figured, for
the sake of comparison, from the Silurian limestones of New South ©
Wales. Communicated by the Rey. W. B. Clarke.

It is remarkable as having the expanded apices of the columns on
the lower surface lobulated in larger or smaller divisions, which all
seem to radiate from a central boss. And this arrangement is quite
different from the merely granulated surface observable in the
R. occidentalis (figure 6).

The upper surface too (figured as the lower in the plate, figure 8),
is curiously lobed beneath the surface. Figure 10 represents a
portion of two columns, broken off near the base, and viewed from
within.

Locality —Upper Silurian limestone of Yarradong, between the
, Yass plains and the Murrumbidgee river, New South Wales, a
locality rich in Upper Silurian forms, Tentaculites, Favosites,
Pentamerus, Ormoceras, Trochonema, Rhynchonella, Se.

J. W. SALTER.

February 28th, 1859.

DECADE 1.P1.1
GEOLOGICAL SUIRVIEY OF CANADA. LOWER SILURIAN.
(Chazy )

W. Sowerby sct

yea as
Maclurea LOGaRt. Falter

PLATE 1.

MacuurEA Loeant (page 7).

Figure 1. Maclurea Logani. Natural size. Lower or umbilical surface.

“ 2. <A younger specimen, with the operculum in place.

“¢ 3. Upper view of same specimen, shewing the false umbilicus or
concealed spire. This specimen has suffered some injury, and
has a deep concentric furrow.

“4,5, 6. Exterior, inside and lateral views of an old operculum, with the

apophyses for muscular attachments, a, b.

DECADE I. Pl. 2.
CARTAMA, LOWER SILURIAN
(Trenton)

Fg 3H planulata var murLcata.

Li Y. L- es Haph ust, Oma ds PH a 21a ee |
ceed - — aperia da | _ 9. WH.? spinosa. oe
|. UH4H. larvaia. 2
C_R.Bone del* ; panache

. 3-7. Helicotoma planulata. sd

PLATE Ii.

RAPHISTOMA LAPICIDA (page 12).

Figure 1. Raphistoma lapicida. Side view, with mouth.
Loan 2. — ——. Spire of ditto.

(ou 3 — ——. Base of ditto.

RAPHISTOMA APERTA (page 12).

‘¢ 4. Raphistoma aperta. Upper, lower and side view.

HELICOTOMA PLANULATA (page 14).

Helicotoma planulata. View of the spire.

Same specimen ; under view.

— —. Do. side view.

Dao x

— —. Var. muricata.

HELICOTOMA? SPINOSA (page 15).

“ 9, Helicotoma? spinosa. Slightly magnified; the natural size is indicated
by the cross lines.

* 10. Under view of the same, also magnified.

HELICOTOMA LARVATA (page 15).

‘© 11-13. Helicotoma? larvata. Upper, under and side views.

Oe 14.

The same species, encrusted by a sponge

(Stromatocerium rugosum).

DECADE 1. Pivs.
LOWER SILURIAN,
(Calciferous Sand Rock)

Ophileta compacta, Halter:

W. Sowerby sc*

C.R.Bone delt

PLATE ITI.

OPHILETA COMPACTA (page 16).

Figure 1. Ophileta compacta. Internal sandstone cast; only a portion of one
whorl is left. Internal cast, sandstone, reversed, and shewing the
flat or umbilical surface. c, the inner basal angle; 6, the outer
basal angle; a, the upper angle or keel. The convex dome-like
cast of the deep cup-shaped spire shews distinctly, as the whorls
are broken away.

“¢ 2. Cast of lower or umbilical surface.
“« 3. Exterior of upper or concave side. a, the outer angle or keel;
d, the inner upper angle. A gutta-percha mould, taken from a

cast of the upper surface, representing therefore the true shell.

DEIGAND eee ease
SILURIAN.
( Trenton.)

CEOLOGICAL SURVEY OF CANADA. LOWER

1. Murchisonia serrulata. Patter
2-4 M, helicteres,

5, 6M. bicincta. Hate.

7 M.___, var perangulata.

C.R.Bone delt W. Sowerby sct

PLATE IV.

MURCHISONIA SERRULATA (page 20).
(Not serrata, as in page 20.)

Figure 1. Murchisonia serrulata. Natural size; 1*, a portion magnified.

MURCHISONIA HELICTERES (page 21).

“2. Murchisonia helicteres. A normal specimen.
“ 3,344. —< ——. The same species, irregularly uncoiled. The

sutural edge on the uncoiled whorl is indicated at s.

MURCHISONIA BICINCTA (page 19).

“ 5,6. Murchisonia bicincta, Hall. Ordinary large variety.
Sede — —, —. Variety with more angular whorls, and

without the upper keel. (Var. perangulata, Hall.)

. :
.
Hi Siy A
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;

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ane hei my ,
eat oo <b OS rai ‘at b ryt i

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IF, wy f ‘ : yA Hy ;
oh 6 nit a Ua VER R'E. | he VA iy iy aie it ry)

qj f gt ' : 5 : ree | : ei ia)
fe j : wit SOV ae ayy aide ey * Ty ekedeiee di elimene a a di res .
ea 4 2, b ’ _—_~

it ard, # ‘

y \ Prt DA Pur lee Ni

UR ay ct ae cial ane biel

hit FRE fi Pe

| lige oe i ws ee te
f bal,

pan _ DECADE 1. PL. 5
SUWIRWIEW OIF CAVINAIDA . LOWER SILURIAN
( Trenton. )

Git OiLOGicall

lig Murchisonia gracilis, Hall.

2 2 eae Lees
ae VEMATLEOSA a

C.R.Bone delt , W. Sowerby sct

PLATE F.

MURCHISONIA GRACILIS (page 22).

Figure 1. Murchisonia gracilis, Hall. The cast or body-whorl a good deal
broken away, and shewing the inner reflected lip.
«la, An enlarged whorl, to shew the lines of growth and the smooth

band.

MURCHISONIA VENTRICOSA (page 23).

“2. M. ventricosa, Hall. Of large size. The body-whorl here is also
broken away; hence the pillar-lip, p, and the base of the
whorl, 6, are more prominent and curved than they should be.
At sa slight ridge, just above the suture, is sometimes visible.

«« 2a. Shews the moderately arched lines of growth.

“3. <A smaller specimen, less elongate than usual. The position of the
band high up, near the sutures, is contrasted in this species

with that of M. gracilis, figure 1.

DECADE 1. PIL6
LOWER SILURIAN
(Trenton )

LOGICAL SURVEY OF

2D

fig. 1, Cyclonema Halliana. Latter.) Fig. 4. Eunema singillata Seal torr

SEMI TUTE ed. fi 2 Vagode th

3, Trochonema umbiliata. All 6. Larvonema Murravana. a

PLATE VI.

CYcLONEMA HALLIANA (page 26).

Figure 1. Cyclonema Halliana. Natural size.

“

tt

CYCLONEMA SEMICARINATA (page 27).

2. Cyclonema semicarinata.

Natural size ; 2a, 26, front and back

views, more enlarged.

TROCHONEMA UMBILICATA (page 27).

3. Trochonema (Pleurotomaria) umbilicata, Hall. Three views of one

specimen.

EUNEMA STRIGILLATA (page 29).

4, Eunema strigillata. Two specimens, natural size; 4a, upper part

of whorl, magnified to shew the dichotomous striz.

KUNEMA? PAGODA (page 30).

5. FE? Pagoda. Natural size.

LoxonEMA MuRRAYANA (page 31).

6. Loxconema Murrayana.

An unique specimen, imbedded in limestone.

¥

f DECADE 1.P1.7
GEOLOGICAIL SUIRVIEY OF CANADA LOWER SILURIAN

(Trenton )

Fig. 1-4. Cyrioceras talz, -Bdlinge
& 6. 2 BGs. eee

C.R Bone del . W. Sowerby sc*

PLATE VII.

CYRTOCERAS FALX (page 32).

Figure 1. Cyrtoceras falx, Billings. Side view and section of the larger end,
the siphon on the outer (ventral) side of the curve.

« 2. Section (with siphuncle) of a more compressed form, the compres-
sion partly due to pressure. The tube becomes more and more
cylindrical in age.

« 3, 3a. A younger specimen, from the Ottawa limestone.

«4. A worn specimen, shewing the close septa.

CYRTOCERAS BILuinesir (page 33).

“5. Cyrtoceras Billingsii (C. lamellosum, Hall). Side view. 5* is the

section at the larger end; 5** of the smaller cylindrical end—
the siphon external.

“6. A younger specimen, with closer lamelle of growth.

DECADE 1.P1.8
LOWER SILURIAN.

(Trenton. )

OF CAINAIDA.

GEOLOGICAL SUIRWIEY

SS

Lig 4 5 C contracta. ctaler.
6. grhberula. 2
7. C? astartatormis «od.

lig l. 2. Ctenodonia nasuta. Hal. ap
e Logant. alter.

C. R.Bone delt W Sowerby sct

Figure 1.
ce On

“ce 3

PLATE VIII,

CTENODONTA NASUTA (page 35).

Ctenodonta nasuta, Hall. Natural size.

, —- Large specimen, with external ligament

and hinge-teeth.

CreNOoDONTA LoGant (page 36).

Ctenodonta Logani. Interior of left valve. 3a, the hinge enlarged.

CTENODONTA CONTRACTA (page 37).

Ctenodonta contracta. Var. with posterior sinus well marked.

4a, enlarged, to shew ligament.
— The same, with the sinus obsolete. 5a, the hinge enlarged,

the muscular impressions deep.

CTENODONTA GIBBERULA (page 38).

Ctenodonta gibberula. Interior and exterior of the left valve.

CTENODONTA ASTARTHFORMIS (page 39).

Ctenodonta? astarteformis, Left valve, outside and interior. ‘a,
the hinge-line magnified.

ares.

a oe

—

at
oA

Gib OLOGICAIL

SUWIRWIEw OIF CADNAUDA

Orthis tricenarca.

Ne

Di CAMS Lies
LOWER SILURIAN
(Trenton)

W. Sowerby sc*

es

Figure 1.

vs

2.

PLATE IX.

ORTHIS TRICENARIA (page 39).

Orthis tricenaria, Conrad. Both valves closed. Dorsal view.

The same specimen; ventral view.

Interior of the ventral valve, shewing the muscular impressions (a),

and the ovarian spaces (0).

Interior of the dorsal valve. a, the teeth or brachial processes—

the small linear cardinal process is seen between them. 5, c,

the quadruple muscular impressions

CEOLOGICAL SURVEY OF CANADA

LLL

DECADE Pug
LOWER SILURIAN
(Trenton.)

L_7. Leeceptaculites occidentalis,
Sale Fe australts,

tah

W.Sowerby sc*

=

PLATE X.

RECEPTACULITES OCCIDENTALIS (page 45).

Figure 1. Receptaculites occidentalis. Upper view of a fragment of a large
specimen. At a, a rubbed portion exposes sections of the

cylindrical columns.

A more weathered specimen, upper side shewing the convex ends

bo

of the columns.

“ 3. upped central part of a specimen.

“ 4,5. Detached fragments reversed, the upper side downwards, shewing
the rhomboidal bases to the columns. 4a ditto., shewing the
connecting stolons. 4b, the same magnified.

‘¢ 6. One or two columns magnified, reversed. a, the rhomboidal. gran-
ulated space; b, the connecting basal stolons; c, the apices of
the columns; d, the interstices between them; 6* is the base
of one of the columns, more highly magnified.

“ 7. Shews a portion of the lower surface polished. Some of the
rhomboidal spaces are connected by the stolons with each

other.

RECEPTACULITES AUSTRALIS (page 47).

“ 8. Receptaculites australis, Salter. A new Australian species, intro-
duced for comparison. Lower surface, with the lobed bases of
the columns.

“9. Some of the columns magnified. The stolons are not clearly seen
in this specimen.

*“ 10. View from the inner surface of these lobed bases, shewing the
ramifications of the sarcode highly magnified.

SIA yaks
pA a say

ON RRS