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GEOLOGICAL SURVEY OF MICHIGAN

LOWER PENINSULA

PALEONTOLOGY

FOSSIL CORALS

BY

DR. Gv ROMINGER

STATE GEOLOGIST

(ADVA NCE COPY, UN REVISED BY THE AUTHOR)

NEW YORK

JULIUS BIEN
1876

c-

PALEONTOLOGY

GEOLOGICAL SURVEY OF MICHIGAN

LOWER PENINSULA

PAL^ONTOLOG

FOSSIL CORALS

15Y

DR. C. ROMINGER

STATE GEOLOGIST

(ADVANCE COPY, UNREVISED BY THE AV'IHOR)

NEW YORK

JULIUS BIEN
1876

PALEONTOLOGY.

The stratified rocks forming the surface ^crust of our globe are
very frequently found to contain petrified corals, shells of mollusks,
bones of vertebrates, vegetable remains, or impressions thereof.

The ancients were already well acquainted with this fact, but up
to the eighteenth century naturalists and philosophers were greatly
troubled in seeking for a satisfactory explanation of the origin of
these peculiar forms, so similar to living organisms, yet made of
stone.

One of the first theories on the subject was, that fossils were a
lusus nattirce, or play of nature — that is, an effort of nature to pro-
duce organic forms, a moulding of life shape from inanimate mate-
rial, without fully accomplishing the task to the final act of the in-
spiration of life. The Mosaic account of creation is in full accord
with such views, and it is not at all improbable that Moses,
or whoever was the writer of the biblical accounts of creation, de-
rived his first thoughts upon the process of creation from the ob-
servation of fossils and meditation concerning their origin. It no
doubt appeared to him more reasonable to accept them rather as
half-iinished work than as the remains of once living bodies, whose
position within the rock was inexplicable to him ; and in analogy
with this conception, he imagines man created by the double pro-
cess, first, of moulding his form from earth, and then of the divine
inspiration of life.

During the fourteenth century the hypothesis of the origin of
iossWshy lusus natures heg2in\.o lose credit, and it became generally
recognized that they were the veritable remains of once living or-
ganisms. This being acknowledged, the thought of ascribing the
origin of fossils to the scriptural deluge recommended itself as
plausible, and they were at once, without critical examination of

4 LOWER PENINSULA.

the correctness of this view, universally believed to be the remains
of the animals which perished during this catastrophe, which belief
was obstinately held up to the end of the eighteenth century. At
that time, with the progress made in natural history, so many facts
contradicting this theory had accumulated, that it could no longer be
held. It was clearly recognized that the deluge could not account
for fossils generally ; that there existed an immense difference in
the age of fossils, and that a large number of animal and vegetable
creations came and disappeared again, in ^long-continued succes-
sion, involving the lapse of spaces of time far exceeding former
conceptions of the age of the globe.

The study of the fossils and of the conditions under which they
were found threw an entirely new light on the earth's history.
Formerly the fossils were mere objects of curiosity ; now^ they be-
came important witnesses to a long series of progressive changes
which the earth must have undergone ages and ages before man
was created, and before the scriptural deluge could have occurred ;
of changes which were rarely sudden reversals of the existing condi-
tions, but which were from the beginning and are now in constant
quiet action — an endless, shifting motion; destroying here and build-
ing up there, with a slowness almost imperceptible, but, in the long
lapse of time, astounding in its effects. The attentive study of fos-
sils led to the discovery that, in the series of rock beds composing
the earth's crust, certain animal forms were confined to a certain
definite group of strata, which, in ascending to higher beds, disap-
peared gradually or abruptly, and were replaced by new forms ;
the same changes were noticed to occur frequently in ascending
higher and higher. It was further ascertained, on examination of
far remote localities, but built up by an equivalent succession of
rock beds, that, in the distribution of fossils throughout the strata,
the same order is found to exist — that is to say, the equivalent
strata contain in different places the same, or at least very similar
fossils. By deduction from this rule, we may infer that strata con-
taining the same fossils have the same relative age ; we have in the
fossils a standard criterion for the determination of a certain geolog-
ical horizon, irrespective of the character of the rock, which may
be widely different in remote equivalent beds, and independent of
direct observation of the succession of the beds, which may be
hidden from view, or be complicated by irregularities, either through

P ALTEON TOLOG V. 5

the absence of certain layers, or through the intercalation of new
ones not observ^ed in other localities under comparison. In the
fossils we have always an infallible guide, in cases where lithologi-
cal and stratigraphical characters would leave us in an inextricable
perplexity, regarding the position of certain strata.

The value of palaeontology, as fundamental to all our geologi-
cal knowledge, is at present generally understood. Such of the
States as have instituted a geological survey of their territory
have shown their appreciation of its importance by making liberal
provisions by law for a careful collection of fossils, and for the sub-
sequent description and delineation in their report of all new and
interesting forms.

During the progress of the geological survey of Michigan, a rich
harvest of fossils has been made, the class of corals in particular
being well represented in the collections. Our law provides that
due attention shall be paid to the description and figuring of new or
imperfectly known specimens. The number falling within this cat-
egory is so great that the limited compass allowed for the present
report will not admit of their being all described.

Being compelled, therefore, to make a selection out of the mass of
material, I proposed to the Geological Board to give a more elab-
orate treatise on the indigenous fossil corals, omitting all descrip-
tion of mollusks and other fossil remains treated of and so amply
illustrated in the repjorts of other States, while the corals have re-
ceived comparatively little attention, notwithstanding that they be-
long to the forms most significant of the age of strata. The Board
consented to this plan, and I hope the general reader as well as
the scientist will not be displeased at being offered a carefully
elaborated monograph of this class, instead of a superficial descrip-
tion of a great variety of species from all classes. These were the
alternatives, as the fixed limits of the volume, as already stated,
would not permit my entering upon a critical examination of the
whole field of palaeontology.

The species descriptions are illustrated by photographic figures,
printed by the new Albertotype process. The figures are necessa-
rily somewhat imperfect, because their convexity would not allow
their entire surface to be within the proper focus of the instrument.
Their absolute correctness in other respects, however, compensates
fully for these unavoidable imperfections.

6 LOWER PENINSULA.

The figures of the plates could not be numbered without great
inconvenience to the printer, on which account I have adopted a
rule applying to all, which I think will serve the purpose.

In all the text references the upper right-hand figure is i ; the
upper left-hand figure is 2 ; the lower left-hand figure is 3, and the
lower right-hand, 4. Some plates have several figures on each of
their two or four principal divisions. In these cases, to save the
reader from mistakes and confusion, I have been very explicit in
my descriptions, in indicating the particular figure referred to.

CORALS.

Corals are sea animals of low organization. The general struc-
ture of their body, in the simpler forms, is that of a membranaceous
bag, frequently plicated into radially arranged folds. This bag has
only one central opening, which serves both as mouth and anus,
and is surrounded by a variable number of retractile hollow ten-
tacles. In the compound forms the individuals are frequently so
intimately united, that the exact demarkation of one body from the
other is lost.

Circulation imperfect, not propelled by a heart. Nervous system
very rudimentary ; no special organs of senses. Propagation part-
Iv by eggs, forming in the plications within the bag, and ejected at
maturity through the central opening, partly by buds sprouting
from the surface, or by division and individualization of single parts
of the body. Some corals are entirely soft and fleshy ; others se-
crete a horny or stony basal skeleton or domjcil, into which the
fleshy parts can be partially retracted. All the fossil corals belong
to this latter tribe, and this stony Polyparium is the only portion
of them preserved. Soft corals, not capable of preservation, have
left no traces within the rocks, although, from analogy of present
conditions with former, we have a right to assume that they
were not missing in the ancient fauna.

The systematic arrangements under which corals have been de-
scribed by various naturalists are very different.

Milne-Edwards is one of the writers who has paid special atten-
tion to the fossil forms of corals. I consider it, therefore, for the

PAL.-EONTOLOG V.

present purpose, most appropriate to adopt his system as a basis.
It requires, however, important rectifications, which I will make as
I proceed with my descriptions.

CLASSIFICATION OF POLYPES.

1!V MILNE-EDWARDS.

I. Corallia.
11. Hydroida : soft, not represented in fossil condition.

The Corallia are divided into three orders:

1. Zoantharia.

2. Alcyonaria.

3. Podactinai'ia.

Of these, the first order includes the principal part of all the fossil
corals; the second is only represented by Graptolites, and the third
has no palaeozoic representative.

The Zoantharia are divided into seven sub-orders :

1. Malacodernia : soft, not fossil.

2. Apora : recent coralline forms.

Milne-Edwards placed the genus Palceocyclus with this sub-order,
but its afifinities are decidedly nearer to forms placed in another sub-
order, the Z. rugosa.

3. Perforata. — Abundantly represented in the mesozoic and re-
cent coralline fauna, but not in the palaeozoic. The genus Protaraea,
placed here by Milne-Edwards, belongs to the next following order,
the tabttlata, and the genus Plcurodictiiini, likewise enumerated
among the Zoanth. perforata, is created by simply mistaking the
casts of a Michelinia for a particular type of organization, very ap-
propriately connected with the specific by-name of ^'' problcmatiaiviy

4. Tabulata.

5. Rugosa.

These last two orders comprise nearly all palaeozoic corals, and
will form the special object of consideration in subsequent pages,

6. Tubjilosa. — An order formed to include the genus Aulopora
and Pyrgia, both of which genera are in intimate relationship with
certain types placed under the Zoanth. tabulata, with which I am
going to describe them.

8 LOWER PENINSULA.

7. ZoantJi. caiiliatla. — These have no representatives of paljeozoic
date.

ZoantJiaria tabiilata. — The corals comprehended under this sub-
order are composed of tubular polyp cells, septate by transverse
diaphragms, and radiated by vertical crests, which in some forms
are very well developed, in others remain in rudimentary condi-
tion, or are entirely obsolete in individuals. Two principal groups
of tabulata are distinguished :

I. Millcporida;. — Compound polyparia built up by two structural
elements ; of larger radiated tubes, forming the visceral cavities for
the animal, and of a ccenenchymatose tissue surrounding the tubes,
likewise either of tubular structure, or of a cellulose vesiculous
nature.

II. Favositid<B. — Compound polyparia formed of aggregated tu-
bules of equal structure, without intervention of any other tissue
element between the tube walls. The radiation of the tubes by
vertical crests is often more rudimentary in its development than
in the former order of Milleporids.

The palaeozoic forms of the ]\Iillcporidce are represented by the
genera : Heliolites, Lyellia, and Plasmopora, to which Milne-Edwards
adds Propora, Battersbyia, and Fistulipora. The latter genus has
only an external resemblance to the Milleporidae. It belongs to the
Bryozoa, as I have already demonstrated in an essay published in
1866, in the proceedings of the Academy of Natural Sciences, of
Philadelphia.

The genera Propora and Battersbyia, I was not able to recognize
among the American fossils, unless a form which I have provision-
. ally named Hoitghtonia should be identical with the Propora.

The second order of Zoanth. tab., the Favositidcc, is grouped by
Milne-Edwards into six sub-orders :

I. Favositinae. 2. Chaetetinae. 3. Halysitinae. 4. Pocilloporina;.
5. Seriatoporinae. 6. Thecideae. P'rom these the Chaetetinrt; have
to be eliminated as a type belonging to the Bryozoa.

The genera arranged under the Pocilloporinae, Seriatoporinae, and
Thecideae are in perfect conformity of structure with the Favosi-
tinae, and I see no reason for their separation from them — with one
exception, that of the genus Cohimnaria, which is a form of pecu-
liar type, exhibiting no great affinity with the genus Thecia, which
has been placed by Milne-Edwards in the same sub-order with it.

PALEONTOLOGY. g

The sub-order Halysitinae includes the genera Halysites, Syringo-
pora, Fletcheria, Thecostegites, and Chonostegites. The latter
two genera I place under the Favositinae as a form intimately
related in structure to Michelinia. The genus Thecostegites is only
created through mistaking compact, short-jointed specimens of
Syringopora tabulata for the type for a new genus, which assertion
I shall prove farther on by giving a detailed description of the
species. I have, in view of the above statements, reduced the six
sub-orders of Favositidae to three, namely, Favositince, Halysitimr,
and ColuninaricE, under which headings I will describe the genera
and species found in the State of Michigan, taking the liberty
sometimes of drawing into the descriptions specimens found in
the foreign territory of the neighboring States, Avhen I find it
necessary for a full illustration of a certain group of organisms,
of which the material found in the State is too imperfect. In the
production of photographic figures specially, I had frequently
to resort to specimens not found in Michigan localities — not that I
am without indigenous ones of the same order, but because these
are in a less perfect condition.

MILLEPORIDtE.

Genus HELIOLITES, Guettard.

Large visceral tubes, circular, scarcely or not at all projecting
above the general surface, radiated by twelve longitudinal crests,
not reaching the centre, and often being only low, spinulose carina:.
Numerous transverse diaphragms intersect their channels. Cce-
nenchym abundant, formed of much smaller, not radiated, poly-
gonal tubules, which, divided by regularly disposed, transverse
diaphragms, represent vertical rows of subquadratic cell spaces
filling the interstitial space between the larger circular tubes. No
lateral anastomosis betvv^een tubes or cell spaces.

Several species of Heliolites occur in the Niagara group of Michi-
gan. The specimens are all found in silicified condition, and the
more delicate surface characters have suffered partial obliteration
by the process of petrification.

lO LOWER PENINSULA.

HELIOLITES MEGASTOMA, McCoy.

Visceral tubes about two millimeters wide. Orifices crenulated
by a cycle of twelve low vertical crests. Diaphragms flat, closely
set. Coenenchym tubules about half a millimeter wide. Interstitial
spaces filled by them, subject to many variations in different speci-
mens ; in some the distance between the larger circular tubes is
smaller than their own diameter, in others it is larger. External
mode of growth convex, or in subplane expansions, covered by a
concentrically wrinkled epitheca on the impressed lower concave
side. It is a common species in the Niagara group of Drummond's
Island, Point Detour, and many other localities ; in the drift depos-
its of the Lower Peninsula it also frequently occurs. The Niagara
group of Indiana, Iowa, Kentucky, etc., and the Silurian strata of
Bohemia inclose forms perfectly identical with those of Michigan.

Plate I. — Fig. 3 represents a silicified specimen from Point
Detour, natural size, the structural details of which will all be seen
more distinctly by using a weak magnifier, when looking at the figure.

HELIOLITES PYRIFORMIS, Hall.

Tubes about one millimeter wide, radiated by a cycle of twelve
spinulose, vertical crests. Diaphragms flat, simple, or anchylosed
with the spinulose, vertical crests into an irregularly cellulose mass,
filling the tube cavities. Coenenchym of minutely tubular struc-
ture, divided by transverse septa. Interstitial spaces between the
larger tubes equal to or larger than one tube diameter. External
growth, subglobular.

The mode by which the specimens are preserved alters their ap-
pearance considerably. Some of the specimens, with simple trans-
verse diaphragms exposed to weathering, are apt to have the dia-
phragms of the larger tubes destroyed, and the channels of the
larger tubes are seen all open, surrounded by the well-preserved
mass of the smaller coenenchym tubules. In other specimens where
the vertical crests, intermingling with the diaphragms, give the larger
tubes more strength, the coenenchym is found destroyed and the
larger tubes are preserved, and present themselves as free cylindri-
cal, longitudinally carinated columns. Still other specimens are

PALA£ONTOLOGT. 1 1

found, in which, by incrustation of the wall substance, the tube
channels are narrowed, and the contrast between the larger and
smaller tubes is diminished ; these have a spongious aspect, and ap-
pear at first glance to be a fossil of totally different structure from
the more regularly formed specimens. It is sometimes dif^cult to
distinguish this species from the next described species, Hcliolitcs
intcrstinctus. This species is found in association with the former
kind at Drummond's Island, and in the other mentioned localities
in Michigan ; it is likewise common in the drift. The Niagara
group of Iowa and Wisconsin incloses the same form.

Plate I. — Fig. 2 represents two specimens from Drummond's
Island, in natural size.

HELIOLITES INTERSTINCTUS, Linn.

Visceral tubes from one to one and a half millimeter in width.
Vertical crests quite prominent, almost reaching the centre, and
composed of rows of spinules pointing obliquely upward with their
apices. Coenenchym composed of minute, polygonal, transversely
septate tubules. Interstitial spaces between the larger tubes usu-
ally much exceeding one tube diameter. Diaphragms rarely flat,
and simple, generally complicated into a cellulose network with the
spinulose, vertical crests, with a nodular projection in the centre,
formed by the converging apices of the spinules. No central col-
umella. In vertical sections the channels of the larger tubes are
scarcely distinguishable from the surrounding septate ccenenchym,
because the intersection of the spinules with the diaphragms divides
the interior of the larger tubes into small cell spaces similar to the
surrounding coenenchym tissue. The visceral tubes always resist.
decay better than the coenenchym, and are preserved as slender,
longitudinally carinated columns, held together by a portion of un-
destroyed ccenenchym. The mode of growth is in discoid, subplane
expansions, with a concentrically wrinkled epithecal crust on the.
lower side.

It is of rare occurrence in Michigan ; occasionally specimens
are found in the drift of the Lower Peninsula, but it is a very com-
mon species in the Niagara group of Indiana, Kentucky, Tennessee,
etc.

Plate I. — Fig. i is a specimen from Louisville, Ky., in calcified

12 LOWER PENINSULA.

condition. Specimens from the Silurian strata of Bohemia perfectly
correspond with the American form.

HELIOLITES SUBTUBULATUS (?) McCoy.

Visceral tubes only half a millimeter wide, with twelve delicate
marginal crenulations around the orifices. Coenenchym tubular,
very minute. Interstitial spaces between the larger tubes broad.
Transverse diaphragms simple, regular, disposed at close distances.

External growth in convex, rounded masses. I have identified
this form with McCoy's species on account of a general resemblance
to his figures, but had no opportunity to compare specimens. It
occurs in the Niagara group of Point Detour, Drummond's Island,
etc. ; also in Iowa, at Masonville.

Plate I. — Fig. 4, lower specimen found at Marblehead, of Drum-
mond's Island, natural size ; upper specimen from Masonville,
Iowa.

PLASMOPORA.

Milne-Edwards.

Visceral tubes circular, not projecting above the general sur-
face, radiated by twelve well-developed vertical rows of spinulose
projections. Coenenchym formed of stout vertical laminre, which
partly appear as the extraneous continuation of the radial crests
'of the tubes. They intersect each other in irregular manner, in-
closing tubular spaces between, which are transversely septate, like
the tubules of the coenenchym of Heliolites ; but while in the latter
they are actually closed tube channels, in the coenenchym of Plas-
mopora no closed tube walls seem to exist, ^but_oi'ily lac_uiise(in-
jttci^c^ i-n f^Sfi ..^ tersecting each othc^betwcen the vertical plates, Diaphragms of
~" visceral tubes numerous, flat, but usually complicated by intersec-

tion with the vertical rows of spinules almost reaching to the
centre.

The coenenchym usually resists weathering better than the
tubes — large, open channels being found to occupy the places of
the latter in such specimens.

J- f «»j

PALAEONTOLOGY. 1 3

Plasmopora and Heliolites are in structure so similar that it
often becomes difficult to make a distinction between the two
forms.

PLASMOPORA FOLLIS, Milne-Edwards.

Tubes from one to one and a half millimeter in diameter, separated
with their circular crenulated orifices by interstitial spaces equal to a
tube diameter or smaller. Vertical laminae of the coenenchym often
holding aposition toward the tubes as of external radii, and inclosing,
by mutual junction and intersection by transverse dissepiments, ver-
tical rows of cell spaces very similar to the coenenchym of Helio-
lites ; but the vertical walls of these septate pseudo tubules are
much stouter than the tubular walls in Heliolites, and comparative-
ly much stouter than the transverse septal laminae dividing them.
Grows in pyriform or subcylindrical, club-shaped masses of mod-
erate size, not often exceeding that of a man's fist ; the conical base
is attached and exhibits a rudimentary epithecal crust ; in the
subcylindrical specimens, the coenenchym cells and orifices on the
side faces of the stems are usually closed, and only those of the
convex terminal disk apert. Rarely found in the Niagara group
of Point Detour,_and sometimes in the drift of Michigan. It is a
very common species, however, in the Niagara group of Indiana,
Kentucky, and Tennessee.

Plate HI.— Fig. 2 represents two species of Plasmopora, arranged
in a group to economize space. The two upper figures are small
silicified specimens of Plasmopora follis ; the elongated one was
found at Paul's Station, Indiana ; the other, of rounded form, is
from Charleston Landing, Indiana.

PLASMOPORA ELEGANS, Hall.

Synon., Heliolites elegans, Hall.

Heliol. spinipora. Hall.
Plasmopora scita (?) Milne-Edwards.

Tubes a little over half a millimeter wide, radiated by twelve prom-
inent longitudinal rows of spinules obliquely directed upward, and
nearly reaching the centre. Diaphragms complicated and anchy-

14 LOWER PENINSULA.

losed with the spinulose projections. Coenenchym composed of
very stout vertical lamels, with delicate transverse leaflets intersect-
ing them. Intervals between the tubes about as large or larger
than a tube diameter. Growth pyriform or globular. Found in
the drift deposits of Michigan. Common in the Niagara group of
New York, Indiana, and Kentucky.

Plate III., Fig. 2. — The two lower specimens, both silicified, are
from Paul's Station, Indiana.

LYELLIA.

Milne Edwards.

Visceral tubes circular, with orifices projecting above the general
surface, radiated by twelve conspicuous vertical rows of spinules,
and transversely septate by subplane diaphragms.

Coenenchym abundant, formed of convex, vesiculous, horizontal
plates of unequal size, extending in interlacing layers across the
intertubular interstices, and inclosing blister-like cavities much
resembling the vesiculous tissue of a Cystiphyllum.

LYELLIA AMERICANA, Milne-Edwards.

Synon., Heliolites macrostylus, Hall.

Tubes 1 1 to 2 millimeters wide, radial crests almost extending
to the centre, and decurrent on the outer projecting part of the
orifices, but not prolongated across the interstices, which are
divided into a network of irregular angular cell spaces, or are, in
weathered specimens, of blistered aspect. Transverse diaphragms
subplane, often warped, closely set. Interstices between the tubes
larger than one tube diameter. Vesiculous plates of coenenchym of
irregular, coarser, or smaller size, frequently found partially de-
stroyed by decay, in which cases the tubes present themselves as
free, longitudinally carinated columns, held together by such of the
coenenchym as escaped destruction. Some of the specimens of
Sarcinula represented by Goldfuss are doubtless weathered speci-
mens of Lyellia. {Vide Sarcinula costata, Goldf. Tb. 24 f. 11.)

PAL.-EONTOLOGY. 1 5

Growth in large convex expansions, with an epithccal crust on the
lower, often concave side, or of lenticular or pyriform shape, with
conical basal side. Found abundantly on Drummond's Island,
Point Detour, and in other localities of Niagara exposures in Michi-
gan ; of frequent occurrence also in the drift of the Lower Peninsu-
la, and common in the Niagara group of Iowa.

Plate II. — Fig. i. Surface view of a silicified specimen from
Point Detour, Lake Huron. Fig. 2. Side view of a weathered
specimen presenting the tubes as partially free columns connected
by the remains of the coenenchym vesicles.

LYELLIA PAPILLATA, Nov. Spec.

Tubes circular, not projecting above the general surface, crenu-
lated at the margins by twelve spinulose vertical crests. Diameter
of tubes about i|^ millimeter. Interstitial spaces as wide as a tube
diameter, or narrower, obscurely radiated on the surface by arrange-
ment of the coenenchym vesicles in conformity with the radial
crests of the inside. Diaphragms convex, with deeply depressed
margin, projecting within the orifices as rounded monticules, deco-
rated with granules. In weathered specimens the tubes stand out
as free, longitudinally carinated columns, as in the former species.
Mode of growth convex hemispherical above, flat or concave at the
lower side, which' is covered by a concentrically wrinkled epitheca,
or sometimes incrusting other bodies. Found abundantly in the
Niagara group of Point Detour and at Drummond's Island.

Plate II. — Fig. 3 is a silicified specimen from Point Detour,
Lake Huron.

LYELLIA DECIPIENS, Nov. Spec.

Flat, undose expansions of laminated structure. Tubes one
millimeter wide, orifices not projecting, crenulated by twelve mar-
ginal crests. Diaphragms slightly convex. Interstitial spaces
usually larger than one tube diameter, their surface delicately
reticulated by circumscribed cell spaces, as in Heliolites, but in
vertical sections exhibiting a distinctly interlacing vesiculose struc-
ture, and not a tubular coenenchym. Found in the Niagara

1 6 LOWER PENINSULA.

group of Point Detour and Drummond's Island, Exteriorly it
fully resembles Heliolites interstinctus.

Plate III. — Fig. i represents a silicified specimen from Point De-
tour, Lake Huron.

LYELLIA PARVITUBA, Nov. Spec.

Tubes one millimeter wide, with projecting orificial rims, radi-
ated within by prominent spinulose crests, and on the surface
of the interstices by the converging arrangement of the coenen-
chym vesicles. Interstitial spaces about equal to a tube di-
ameter, vesicles rather coarse. Diaphragms subplane, granulose.
Growth explanate, discoid, with a concentrically wrinkled epi-
theca on the lower side. Rarely found in the Niagara group of
Drummond's Island. In the Niagara group of Indiana and Ken-
tucky this species is very common, and is partly found silicified,
partly in calcified specimens with finely preserved structure.

Plate II. — Fig. 4 is a calcified specimen from Louisville, Ky.

Various other forms described by Billings under the name of
Heliolites are by structure true Lyellias, as Heliolites affinis, Bil-
lings ; Heliolites speciosus, Billings ; Heliolites exigiius, Billings : all
found at Anticosti Island.

HOUGHTONIA.

N. Gen.

Tubes circular, with projecting rims ; cavity lined by twenty
or more longitudinal crests, and transversely septate by subplane
diaphragms. Coenenchym formed of irregularly lacunose cell spaces
anastomosing amongst themselves, and frequently by pores with
the tube channels. Intertubular interstices narrow — the tubes are
often in immediate contiguity, so that the intertubular coenenchym
becomes restricted to the corners left between the joining tubes.
No pore communication between the contiguous tube walls.

PAL.-EONTOLOG V. I 7

HOUGHTONIA HURONICA, Nov. Spec.

Globular masses, from the size of a man's fist to that of a foot in
diameter, with a basal scar of attachment. Tubes from two to
three millimeters in diameter. Interstitial spaces narrow, or tubes
in partial immediate contiguity without intervention of coenenchym
cells. Vertical crests spinulose. Diaphragms numerous, slightly
concave, and usually coincident with linear constrictions of the
tubes. By intersection of the vertical crests with these constricted
annular rims, the inner surface of the tubes becomes cancellated by
regular, square-shaped conical pits, the bottom of which is often,
but not always, perforated, and communicates with the cell spaces
of the surrounding coenenchym.

Occurs in the Hudson River group of Drummond's Island,
associated with Columnaria stellata. It is likewise found abun-
dantly in the upper part of the Cincinnati group at Madison,
Indiana ; more rarely in the lower strata of the same locality.

Plate III. — Fig. 3 is a lateral view of a specimen from Drum-
mond's Island, split open. Fig. 4 is a surface view of the same.
2

FAVOSITID^.

Sub-order, FAVOSITIN^.

Compound polyparia, formed of intimately connected elongato-
conical tubes, diverging from an imaginary axis, and frequently
originating from a single mother-tube by prolific lateral gemma-
tion, constantly repeating.

In some forms the tubes are in close connection in their whole
length ; in others the tubes become free at their ends. In contigu-
ity the tube channels are anastomosing by lateral pores. Trans-
verse diaphragms generally intersect the tube channels, but are
sometimes absent, either from being destroyed, or from non-devel-
opment, which latter is usually found to be the case in forms
with very stout thickened tube walls. The inner tube cavity is, in
the majority of Favositinae, radiated by a cycle of longitudinal
crests, or rows of spinules or squamiform horizontal leaflets pro-
jecting from the walls, which are separated by deep intervening
furrows. In other forms the crests are obsolete, the radial struc-
ture being indicated only by shallow longitudinal furrows, and in
others still the tube cavity is entirely destitute of crests or longi-
tudinal furrows.

The following genera are representing this sub-order: i. Favosi-
tes ; 2. Alveolites ; 3. Limaria ; 4. Cladopora ; 5. Striatopora ;
6. Dendropora ; 7. Thecia ; 8. Vermipora ; 9. Qucnstedtia ; 10.
Michelinia.

FAVOSITES.

Massive or dendroid polyparia, with polygonal or circular orifices,
not or rarely projecting above the general surface, and opening
almost rectangularly to it. Tubes intersected by transverse dia-

PAL^ONTOLOG V. I q

phragms, cither simple, or compound through the anchylosis of
several plates meeting at angles, or rendered imperfect by partial
plates not anchylosed. Tube cavity exhibiting twelve longitudinal
furrows, and having the band-like intermediate spaces frequently
decorated with one or several vertical rows of spinules, or with a
row of horizontal, squamiform leaflets. These characters of radi-
ation are, however, not in all species equally distinct, becoming in
some specimens nearly obsolete, while in others of the same kind
they may be exhibited in obvious development. The rows of
squamose projections, peculiar to certain Devonian forms, by com-
ing in contact and adhering together at their joined edges, form
compound, perfect, or incomplete diaphragms, interposed between
the regularly formed simple diaphragms, and in some specimens
these prevail to such an extent as to altogether exclude the regular
diaphragms.

Milne-Edwards proposed for Favosites of the above indicated
structure the name Einmoiisia, but the character of the dia-
phragms in the forms in question is so variable and inconstant,,
that one and the same specimen, or even the same identical tube
channels, may at a certain period of growth be intersected by com-,
pound complicated diaphragms, exhibiting at another only sim--
ple, straight diaphragms like other forms of Favosites, while in
the prolongation of the tubes they may be divided again by com-
pound or imperfect septa. A character so changeable and peculiar
to almost every one of the Devonian species of Favosites can not
be used as a generic distinction for those which have it in a more-
marked degree than the others. Milne-Edwards has also con-
fused with his Emmonsia a species which stands in no special rela-^
tionship to the other forrris ; his Emmonsia cylindrica is a true
typical form of a MicJiclinia,

The genus Favosites and the whole family of Favositoids had'
comparatively a very brief period of existence. The first forms-
appear in the upper Silurian deposits (Clinton group). During the-
Niagara period and the Devonian era, Favositoids abounded, and
were the prevailing representatives of coralline life. The carbon-
iferous strata inclose only a few of these forms, and in later depos-
its no representative of the genus is known. The Silurian forms
differ from the Devonian Favosites by invariably having simple dia-
phragms, and by the spinulose character of their radial crests. The

20 LOWER PENINSULA.

majority of the Devonian forms, instead of longitudinal rows of
teretiform spinules, have rows of horizontal squamulae, which, as
already mentioned, sometimes coalesce into transverse compound
laminae, taking the place of the regular diaphragms, which case
never occurs in a Niagara species.

FAVOSITES FAVOSUS, Goldfuss.

Synon., Calamopora favosa, Goldfuss.
Favosites Niagarensis, Hall, in part.

Tubes polygonal, of uniform size in the same specimens, but
in different specimens variable, from a diameter of six milli-
meters to that of two. Internal circumference of tubes longi-
tudinally striate by twelve furrows, with intermediate, broader,
band-like spaces, which are crowded with slender spinulose pro-
jections, either in irregularly dispersed position, or arranged in
longitudinal or transverse undulating rows, in accordance with
the undose, transverse wrinkles of growth visible on the out-
side of the well-preserved tube walls. Diaphragms convex or
flat, or even deeply concave, closely approximated or wide apart.
All these variations of structure are sometimes observable in one
and the same specimen, but usually the different variations of
form mentioned are represented by different specimens. The dia-
phragms are marked with concentric wrinkles of growth parallel
with the polygonal outlines of the tubes, and their entire surface is
ornamented by delicate granules or spinules similar to those pro-
jecting from the side walls of the tubes. The margins of the dia-
phragms at their junction with the side walls are deflected into
;siphon-like depressions, frequently twelve in number, and coinciding
with the twelve longitudinal furrows. In many specimens only
five or six such siphonal depressions are developed, while in the cir-
cumference of some of the very large tubes I counted twenty.
These latter are exceptions. In certain specimens the diaphragms
connect with the side walls without any perceptible depression.

Lateral pores connecting the tubes, of moderate size, surrounded
by a raised rim, forming on each side of the polygonal tubes,
according to its width, a single, or double, or triple row. The pores

PALJEONTOLOG Y. 2 I

are never much crowded, and hold no definite position in relation
to each other in the adjoining rows, sometimes found alternating,
sometimes opposite, or negligently disseminated.
\ External form of polyparia hemispherical, or discoid, lenticular,
with a concentrically wrinkled epithecal crust on the lower centrally
attached side.

Occurs abundantly in the Niagara group of Drummond's Island,
Point Detour, and all along the south shore of the Upper Penin-
sula of Michigan ; also common in the drift deposits, and in the
Niagara group of Wisconsin, Iowa, etc. The above species descrip-
tion comprises specimens so much differing in aspect, that it seems
strange to present them as belonging to one species. A Favosites
with tubes six millimeters wide and one with tubes measuring
only two are in great contrast. It may be said also that specimens
with convex diaphragms and rough spinulose tube walls bear little
resemblance to others having perfectly even diaphragms and almost
smooth tube cavities ; yet on careful examination of large collec-
tions of these forms, we find them all so much linked together by
intermediate gradations that no line can be drawn between one
and another.

Plate IV. represents four specimens, which I consider as varie-
ties of Favos. favosus. Fig. i is the fragment of a large silicified
specimen with tubes about four or five millimeters in width, flat
diaphragms with numerous marginal depressions, and with deli-
cately spinulose tube walls. Found at Drummond's Island. Fig. 2
is a specimen from Point Detour, with still larger tubes of simi-
lar structure. The edges of the cells are noticed in the figure to
be faintly crenulated by the twelve longitudinal furrows. Figs.
3 and 4 are specimens with convex diaphragms, of different tube
size, with well-developed marginal depressions ; surface of dia-
phragms and inner face of tube walls spinulose. Found associated
with the former.

Plate V. — Fig. 2 is a specimen fully agreeing with Fig. i , Plate IV.,
but of smaller tube size. Favosites Gothlandica, of Goldfuss, cor-
responds with this specimen ; Favosites Niagarensis, Hall, includes
forms of this kind also, but the name Gothlandica is applied to so
many entirely different forms of Favosites, that I totally abstain
from using it. The name Niagarensis, Hall, I have restricted to a
form with smaller tubes.

2 2 LOWER PENINSULA.

FAVOSITES NIAGARENSIS, Hall.

Tubes about one and a half millimeter wide, of equal size in
the same specimens, polygonal. Diaphragms flat, placed at vari-
ous distances, sometimes very close, sometimes more than one
tube diameter apart. Inner surface of tubes delicately spinulose.
Spinules in irregularly dispersed position. Pores situated in close
proximity to the angles of the tubes, not very numerous.

External growth in convex masses, with an epithecal crust on the
lower side. Occurs associated with Fav. favosus in the Niagara
group of Michigan, Iowa, Kentucky, etc. It differs from that
species principally in the position of the pores near the angles, and
in the small tube size ; is not connecting with the specimens, Fig.
2, on the same plate, by gradation, an obvious break existing be-
tween them.

Plate V. — Fig. i is a silicified specimen from Point Detour.

FAVOSITES HISPIDUS, Nov. Spec.

Tubes a little over one millimeter and a half wide, equal, poly-
gonal, radiated by long projecting spinules, almost reaching to the
centre. Spinules disposed in irregular longitudinal rows, unequal
in size, and more than twelve in number in the circumference of a
tube. Diaphragms flat, closely set. Pores very numerous, generally
forming two rows on each side. Of convex, discoidal growth, with
an epitheca below, as in the other forms. Occurs associated with the
preceding species in the Niagara group of Drummond's Island and
Point Detour.

Plate V. — Fig. 4 is a silicified fragment found at Point Detour.

FAVOSITES VENUSTUS, Hall.

Synon., AsTROCERiUM venustum, Hall.
FAVOSITES Hl^lNGERl, Milne-Edwards.

Tubules small, not over one millimeter wide, rounded-polygonal,
of equal size. Tubes radiated by long spinules, as in the former
species. Spinules in twelve distinct longitudinal rows. Diaphragms

PAL.EONTOLOG V.

23

flat, or gently convex, closely approximated. Pores in one, rarely
in two rows on each side.

Grows in large, massive expansions, with an epitheca on the lower
side.

Found abundantly in the Niagara group of Michigan, and loose
in the drift ; it likewise occurs in the Niagara strata of Iowa, In-
diana, Kentucky, and New York.

Plate V. — Fig. 3 is a silicified specimen from Drummond's Island.

FAVOSITES OBLIQUUS, Nov. Spec.

Tubes polygonal, compressed, like an Alveolites, and opening
oblique to the surface. Large diameter of tubes, three millimeters ;
small diameter variable according to the degree of compression.
In rare instances the tubes are not compressed, or only slightly so,
and open rectangularly to the surface. The inner circumference
of the tube walls is striate by twelve longitudinal furrows with in-
termediate band-like spaces, each of which bears several longitu-
dinal rows of spinules. Diaphragms subplane, with from eight to
twelve marginal depressions, which, together with the longitudinal
furrows and spinulose interstices, give the orifices a very decora-
tive, stelliform aspect. The surface of the diaphragms is covered
with delicate spinules, like the rest of the inner surface of the tubes.
Lateral pores form a single row on each side, wherein it differs from
Alveolites, which has larger pores, confined to the two lateral edges,
or to their vicinity.

Large, undose expansions, with an epithecal crust on the lower
side. Common in the Niagara group of Drummond's Island and
Point Detour ; also found in the drift of the Lower Peninsula
occurs likewise near Masonville, Iowa.

Plate XXVIII. — Fig. 2, silicified specimen from Point Detour.
The Niagara group of New York and Indiana contains a few
other species of Favosites, which are not found in the formation
of Michigan ; these are :

24 LOWER PENINSULA.

FAVOSITES PYRIFORMIS, Hall.

(ASTROCERIUM, Hall.)

It grows in globular or pyriform masses, with a narrow, conical
basal end, surrounded by an epithecal crust. Tubes rounded-
polygonal, unequal in the same specimens, and in different speci-
mens varying from one and a half to three millimeters in diameter.
Diaphragms flat, moderately close. Tube channels radiated by lon-
gitudinal rows of spinules. Pores not very numerous, in a single
or double row on each side. Not figured.

Another species, which I name Favositcs spongilla, is common in
the Niagara group at Paul's Station, Indiana. It is likewise of
pyriform, conical growth, with subramose excrescences from the
discoid upper surface, like some forms of bathing sponges. Tubes
small, not over one millimeter wide, with slightly dilating, sub-
rotund orifices. Diaphragms convex. Tube cavity surrounded by
rows of spinules. Pores not clearly visible in the small silicified
specimens, not larger than a walnut. I have not figured the latter
two species, as they are not found in Michigan, but have thought
it well to mention them as well-marked characteristic forms of the
Niagara group.

FAVOSITES HEMISPHERICUS, Yandell and Shumard.

Synon., FAVOSITES turbinatus, Billings.
Not Fay. hemispil, Milne-Edwards.

Through misapprehension, Milne-Edwards described, under the
name Emmonsia hemispherica, as synonymous with Yandell and
Shumard's species, a Favosites entirely different from the speci-
mens originally designated by that name. All the original speci-
mens of Fav. hemisph. kept in Mr, Yandell's collection are iden-
tical with Favositcs turbinatus of Billings. We have to restore,
therefore, the name hemisphericus to this species, for which it
originally was intended, and give to Milne-Edwards' species the
name Favosites Emmonsii, in place of Emmonsia hemispherica,
which genus, for reasons mentioned above, can not be accepted

PALMONTOLOG V.

25

Favosites hemisphericus is one of the best marked species of
Favosites ; it has a wide range of variations, but its peculiar mode
of growth makes it easily distinguishable from any other form.

The tubes of this form are about two millimeters in diameter, of
unequal size, rounded-polygonal ; tube cavity generally smooth,
intersected by simple flat diaphragms. It occurs rarely that the
diaphragms are compound and angular on the surface, formed by
anchylosis of lateral, squamiform projections. Lateral pores large,
usually in a single row on each side, and moderately distant.
Sometimes, however, two rows of pores may be observed on a side.
The mode of growth mentioned as the most characteristic feature
of this species is nevertheless quite variable. We find polyparia
of subspherical or of biconvex lenticular form, or in cylindrical,
irregularly flexuose, root-like masses, over a foot in length, or in
elongated horn-shape, all of which forms proceed from a single
proliferous mother-tube. At first the polyparium is attached by its
narrow and usually excentrical apex, but soon it becomes free, and
the apex is folded over by the spreading margins of the rapidly
enlarging corallum. The tubes diverge in graceful curves from an
imaginary central axis toward the periphery. Those ends, ter-
minating on the lateral faces of the corallum, have their walls
thickened in their peripheral portion, and their orifices are all
closed by opercula of concentric annular structure, with a central
opening while growing, which is finally closed by a solid nodular
piece. The margins of the opercula are frequently decorated by
twelve carinae converging from the margins toward the centre, but
not reaching it. In specimens with excessively thickened wall
substance, these radial carinae are very obscure, or entirely obliter-
ated. The orifices terminating on the convex disk of the corallum are
all open, more thin-walled than the others, and of more pronounced
polygonal form. It often happens that these centrally situated,
thinner-walled tubes have been destroyed by weathering, while the
exterior lateral tube ends, of massive structure, have resisted and
been preserved. The upper end of such specimens is deeply exca-
vated, and the lenticular forms are transmuted into concave, pa-
telliform dishes. The elongated, horn-shaped specimens termi-
nate in this case with a funnel-shaped excavation resembling the
calyx of a Cyathophyllum, which resemblance is augmented by
the exposure of the side faces of the septate tubes, arching from

26 LOWER PENINSULA.

the centre to the peripheiy, which bear a deceptive Hkeness to
the radial lamellae, with intermediate vesicular cell spaces of the
calyx of a Cyathophyllum.

This species is equally common in the upper part of the Helder-
berg group and in the Hamilton strata in Michigan, and in the
equivalent rock beds of other States east and west of it.

Plate VI. — Figs, i and 2 represent two silicified specimens of
cylindrical growth. A part of the orifices in Fig. i is closed by
opercula plainly exhibiting the twelve marginal radial carinations.
Fig. 2 shows near the left margin opened tube channels with dimly
visible lateral pores. The central part of the specimen is formed
by the casts of tlie tube channels, with deep incisions in the place
of the diaphragms, and papillose prominences represent the
lateral pores. Fig. 3 is a weathered specimen of lenticular form,
having a dish shape presenting opened silicified tube channels,
intersected by diaphragms, and perforated by lateral pores. On
the centre of the specimen I fastened artificially a small horn-
shaped specimen, resembling the calyx of a Cyathophyllum. Fig.
4 is a calcified specimen, in the shape of a Dutchman's nightcap,
found in the Hamilton group of Thunder Bay.

On Plate X., Fig. 2, a calcified specimen of similar growth to
that on Plate VI., Fig. 3, presents the angular tubes of a specimen
split open, with diaphragms and pores faintly indicated. The
latter belongs to the upper Helderberg limestone, and was found
in the drift of Ann Arbor. Specimen, Plate VI., Fig. i, is from
the corniferous limestone of Port Colborne. Fig. 2, Plate VI., is
found in the drift. Fig. 3, Plate VI., is from the Falls of the
Ohio. The small horn-shaped specimen in the centre is from the
drift of Ann Arbor.

FAVOSITES EMMONSII, N. Sp.

Synon., Emmonsia hemispherica, Milne-Edwards.
Favosites ALVEOLARIS, New York Reports.

Tubes unequal, rounded-polygonal, from one to one and a
half millimeter in diameter. Tube channels longitudinally striate
by a cycle of twelve furrows ; of the intermediate band-like spaces,
each one bears a vertical row of horizontal squamae, which are

PAL^ONTOLOG Y. 27

in 'alternating position in the adjoining rows. Diaphragms rarely
simple, straight, generally compound, of anchylosed, lateral squamae,
presenting an angular, substellate surface ; or the interlacing squama;
remain free, and constitute imperfect septa, instead of complete
transverse diaphragms. Pores large, forming in single or double,
or even triple rows on each side, according to its width, and in
places they are much more numerous than in others. It is often
noticeable that tubes, for a certain part of their length, are inter-
sected by simple, straight diaphragms, without complication by
lateral squamae, and again, both above and below, are found
divided by very irregularly interlacing compound septa. This form
grows in large convex masses, or in discoid expansions, with a con-
centrically wrinkled epitheca on the lower side. Found in the
upper Helderberg limestones of Mackinac, and in Monroe County,
in calcified condition. Silicified specimens, partly in the shape of
casts, are frequently found in the drift. The corniferous limestone
of Sandusky, Ohio ; of Port Colborne, Canada ; of the Falls of Ohio ;
of Charleston Landing, Indiana, and of a great number of other
localities, can be mentioned as abounding in specimens of this coral.
Plate VII. — Fig. i is the side-view of a calcified specimen, being a
fragment of a larger rnass, found at Charleston Landing, Indiana ;
lateral pores distinctly visible in the figure. Fig. 2 is a silicified
specimen from the drift of Ann Arbor. It shows the inequality in
the size of tubes (in some specimens in still greater contrast), by
which I was induced to consider these forms as a distinct species
(ot'^i? " American Journal of Science and Arts," November, 1862,
Favos. heliolitiformis), an opinion which I have since changed.
Other specimens are found in which the tubes have nearly all an
equal size.

FAVOSITES HAMILTONENSIS, N. Sp.

i Synon., FAVOSITES ALPENENSIS, Winchell.
FAVOSITES DUMOSUS, Winchell.

Tubes rounded-polygonal, unequal in the same specimens and
in different specimens, variable from one and a half to two and a
half millimeters. Walls stout. Diaphragms regular, simple, but
frequently with lateral squamae interposed, which occasionally be-

2 8 LOWER PENINSULA.

come anchylosed with them and disturb their regularity, but never
to the same degree as in the former species. Connecting pores
large, forming a single row on each side. Rows of lateral squamae,
in some specimens very \vell developed. Other specimens or por-
tions of specimens have smooth tube channels. Mode of growth
globular, or tuberose, or in coarse ramifications, often incrusting
other bodies with the basal portion. Abundantly found in the
Hamilton group of Thunder Bay and Little Traverse Bay, and in
the drift deposits.

Plate VII.— Fig. 3 is a specimen from Stony Point, Thunder Bay.
Fig. 4 is found in the limestone bluffs of Petosky, presenting a
vertical section through a specimen identical with Winchell's
Favositcs diunosiis, which is often found in more slender ramifica-
tions, but also in rounded, tuberose form, in no way differing from
the typical specimens of Hamiltonensis. Favositcs Billingsii I have
named a form nearly related to F. Hamiltonensis, which is the pre-
vailing species in the Hamilton strata of Widder, C. W., and in
the Hamilton group of New York. It grows in large lenticular
disks, sometimes three feet in diameter ; the lower side has a
central point of attachment and is covered by an epithecal crust.
Tubes rounded-polygonal, unequal, from two to three millimeters
wide. Diaphragms flat, with marginal, punctiform depressions,
similar to Favos. alveolaris, Goldfuss. Pores forming a single row
on each side. Lateral squamae rudimentary or absent. Not
figured.

FAVOSITES EPIDERMATUS, Rominger.

Vide " Silliman's Journal," November, 1862.

Tubes from two to three millimeters wide, subequal in the same
specimens, of obtusely polygonal outlines. Tube channels longitu-
dinally striate by a cycle of twelve well-marked furrows, each of
the intermediate band-like spaces bearing a row of horizontal
squama.', sometimes very prominent, and at others in rudimen-
tary condition and partially obsolete. Diaphragms simple, flat,
or warped by marginal depressions, more rarely of broken, angu-
lar surface through complication with the lateral squamae, as
in Favositcs hemisphcricus. Pores comparatively small, surrounded

PALEONTOLOGY. 29

by an elevated rim, in a single or double row on each side, never
very much crowded. Grows in discoid, subundose expansions,
with a delicately wrinkled epithecal crust on the lower side, having
a narrow conical centre serving as point of attachment. Found in
the upper limestones of Mackinac Island, and of frequent occur-
rence in the drift ; likewise common in the corniferous limestone
of Canada, New York, Indiana, and Kentucky. From the forms
with deeply furrowed, crenulated orifices,, and with irregular, com-
pound diaphragms, insensible transitions exist to specimens with
almost smooth, faintly furrowed tubes and with simple, straight
diaphragms. In the size of the tubes also a considerable variation
exists in different specimens.

Plate VIII. — Fig. i is a silicified specimen from Caledonia, N. Y.,
with beautifully crenulated orifices, exhibiting the longitudinal
furrows and intermediate squamose projections. Fig. 2 is a silici-
fied specimen found in the drift of Ann Arbor, seen from the
lower side. Fig. 3 is a specimen from Port Colborne, showing
the diaphragms with marginal depressions, and the general sur-
face aspect.

FAVOSITES CANADENSIS.

{Vide " Silliman's Journal," November, 1862.)

FisTULiPORA Canadensis, Billings.

Undose expansions, with an epithecal crust on the lower side,
sometimes of digitato-ramose or reticulated growth, with orifices
on all sides of the stems. Tubes of two strikingly different sizes.
The larger ones, about one millimeter wide, are circular, dispersed
at subregular intervals between amass of smaller subangular tubes
about one third the size of the circular tubes. The specimens have
a great resemblance to Heliolitesporosus, or, as Mr. Billings thinks,
to Fistulipora. The radiated structure of the tubes and the devel-
opment of lateral pores are sufificient to prove the Favosites type
of the species. The larger tubes are always lined with a cycle of
twelve rows of horizontal squamae ; the smaller tubes are usually
smooth, or exhibit only rudimentary squamae. The diaphragms
of the larger tubes are compound, by complication with the
squamae ; in the smaller tubes the diaphragms are simple ; all the

30 LOWER PENINSULA.

tubes are connected by abundant lateral pores disposed in longi-
tudinal rows. The orifices in certain spots of the surface are often
found closed by opercula.

Found in the upper Helderberg strata of Mackinac and in the
drift deposits of the Lower Peninsula ; also abundantly occurring in
the corniferous limestone of Canada, New York, Indiana, and
Kentucky.

Plate VIII. — Fig. '4 is ia silicified specimen from the drift of
Ann Arbor.

Plate XV. — Fig. 3 is a reticulated branching variety found at
the Falls of the Ohio, kindly lent to me by Mr. Knapp, of Louis-
ville.

I have from the same locality some subramose specimens of simi-
lar structure, but with larger tubes in contiguity and fewer in-
terstitial smaller ones. These form a transition link to another
species to be described hereafter (Favosites radiciformis).

FAVOSITES TUBEROSUS, N. Sp.

Compare Favosites Troostii, Milne-Edwards, and FAVOSITES
BA.SALTIFORMIS PARS, Goldfuss.

Tubes rounded-polygonal, unequal in size, variable, between two
and three millimeters in diameter, with larger tubes up to five
millimeters occasionally intermingled. A cycle of twelve longitu-
dinal rows of stout, horizontal squama lines the inner circumfer-
ence of the tubes. The squamce of the joining rows alternate in
position, are not separated by intermediate furrows, but often
slightly interlock with each other. Pores large and very numerous,
two or three rows on each side, surrounded by a small pit instead
of a projecting rim, and one of them is generally situated directly
beneath each of the squamae.

Diaphragms regular, complete, but often compound, angular on
the surface through intersection with the lateral squamae.

On the lateral surface of the subcylindrical polyparia, many
orifices are found closed by concave opercula of concentrically
wrinkled structure. Some of [them have a small opening in the
centre, which is finally closed up when the operculum is finished.

Found frequently in the drift of Michigan in silicified condi-

PAL/EONTOLOG Y. 3 I

tion, partly in hemispherical masses, with a flat under side cov-
ered by an epitheca, or in elongated, cylindrical or tuberose form.
Similar specimens occur in the corniferous limestone of Canada,
New York, and at the Falls of the Ohio. At the latter locality,
large convex masses are found, which are often erroneously iden-
tified with Favosites maximus, Troost. They are absolutely iden-
tical in structure with the described smaller forms.

Plate IX. — Fig. i is a representation of two small silicified
specimens from the corniferous limestone of Port Colborne. The
upper specimen seems to me identical with the American speci-
men of Favosites basaltica figured by Goldfuss. Its base and the
lower specimen exhibit orifices closed by concave opercula. Fig.
2 is a silicified specimen from the Falls of the Ohio, presenting
open tube channels intersected by diaphragms, and with the walls
perforated by very numerous pores. It shows at the same time
the divergence of the tubes from a basal centre. The rows of
lateral squamae are not as conspicuous in that specimen as in many
others.

FAVOSITES WINCH ELLI, Rominger.
Vide *' Silliman's Journal," November, 1862.

Massive convex polyparia, composed of rounded-polygonal tubes
from three to four millimeters in diameter. Diaphragms com-
plete, simple, warped and depressed at the margins into several
siphon-like pits, or the whole diaphragm is depressed into one deep
excentrical funnel. Tube walls striate by twelve well-marked lon-
gitudinal furrows, destitute of lateral squamae. Pores small, sur-
rounded by a projecting rim, in one or two rows on each side, and
somewhat remote in position.

Found frequently in the drift deposits of Michigan. Some
specimens are inclosed in a white sand rock, associated with Oris-
kany sandstone fossils ; others originate from the corniferous lime-
stone, and various specimens were collected by me from the
Hamilton group of Thunder Bay. It is not uncommon in the cor-
niferous limestone of Canada, New York, and at the Falls of the
Ohio.

Plate IX. — Fig. 3 is a silicified specimen from the Hamilton

32

LOWER PENINSULA.

group of Alpena. Fig. 4 is from the corniferous limestone at Port
Colborne, C. W.

FAVOSITES RADIATUS, N. Sp.

Tubes unequal, rounded-polygonal, one and a half to two and a
half millimeters in width, radiated by twelve prominent rows of
lateral squamae with intervening deep linear furrows. Diaphragms
simple, straight, or warped by marginal, siphon-like depressions ; the
pores are numerous, forming from one to three rows on a side. A
small pit surrounds each of them, as in Favosites tuberosus. The
tubes of some specimens exhibit the lateral rows of squams only
in rudimentary development, and are nearly smooth on the inside,
with flat, moderately distant diaphragms. In other specimens the
squamae project with their elongated linguiform apices nearly to
the centre of the tubes.

Grows in large convex masses. Found in the Hamilton group
of Thunder Bay, also at Eighteen-mile Creek, near Hamburg, N. Y.

Plate X. — Fig. i, surface view of a partly silicified fragment of a
larger convex mass, found in the Hamilton group of Alpena.

FAVOSITES NITELLA, Winchell.

Tubes rounded-polygonal, subequal, stout-walled, not fully one
millimeter in width. Tube channels smooth or beset with distant
lateral squamae. Diaphragms partially simple, regular, partially of
complicated, irregular form, through intersection with the lateral
squamae. Pores large, distant, in a single row on each side. Mode
of growth globular or pyriform or digitato-ramose. Resembles in
structure Favosites Hamiltonensis, differing from it only by much
smaller tube size.

Plate XI. — Fig. 4 represents specimens from the blue shales of
the Hamilton group of Little Traverse Bay. Similar specimens are
found in the Hamilton strata of Thunder Bay. .

FAVOSITES PLACENTA, N. Sp.

Tubes less than one millimeter wide, rounded-polygonal, sub-
equal or unequal, larger tubes and smaller tubes clustered to-
gether in separate spots, or single circular tubes dispersed between

PALAEONTOLOGY. 33

smaller subangular tubes, as in Favos. Canadensis. Diaphragms
partially straight, simple, partially complicated, with lateral hori-
zontal squamae. Pores large, distant, in a single row on each
side. Grows in discoid, undose expansions, with a concentric-
ally wrinkled epitheca covering the lower side. Transition forms,
of digitato-ramose form, connect this species most intimately with
the former species, Fav. nitella. The specimens with single cir-
cular tubes dispersed through the mass of smaller subangular
ones show a close affinity to Favosites Canadensis. Although
specimens from different localities exhibit numerous minor va-
riations, I consider this a well-marked species characteristic of
the Hamilton group, from its base to the highest beds. It
occurs in the upper strata of Partridge Point, in Thunder Bay, in
the next lower strata of Stony Point, in the massive limestones
forming the nucleus of the hillocks at Phelps' quarries, and at
Broadwell's and Trowbridge's mills on Thunder Bay River. In the
outcrops of Little Traverse Bay it is a frequently seen form ; the
drift deposits of the Lower Peninsula likewise contain many speci-
mens. The Hamilton strata of Bosanquet township in Canada
contain it in particularly regular, discoid specimens, which caused
me to name it Placenta. Similar forms are common in the Hamil-
ton group of New York.

Plate XL — Fig. i represents small specimens from Widder, C. W. ;
one presenting the upper surface with subequal tubes, the other the
under side covered by an epithecal crust. Fig. 2 gives specimens
from the same locality, with unequal tubes, approaching in structure
P^av. Canadensis. Fig. 3 is part of a large expansion from the
Hamilton strata at Broadwell's mill, on Thunder Bay River.

FAVOSITES RADICIFORMIS, N. Sp.

Cylindrical and apparently procumbent creeping stems of vari-
able thickness, from the diameter of a finger to that of a man's
wrist, and often several feet in length, with anastomosing or strad-
dling branches. Tubes of two sizes — the larger ones circular, from
one to one and a half millimeter wide, the smaller ones ancrular
filling the interstitial spaces between the larger tubes. Walls
stout. Diaphragms rarely regular, straight, usually complicated
with the rows of lateral squamai, as is the case in Favosites
3

34 LOWER PENINSULA.

J

Emmonsii. Pores large and moderately numerous. The ter-
minal parts of the stems are always formed of comparatively thin-
walled, regularly formed tube orifices. On the lateral faces of the
stems the orifices are often considerably narrowed and disfigured
by incrassation of the tube walls, while the lateral pore channels
retain their usual diameter, and become transformed into long
vermicular ducts of nearly equal size with the principal tube chan-
nels. Such specimens are very unlike, in external appearance,
those with normally formed tube orifices.

I have united within this species two forms, which differ from
each other in the size of the tubes and of the stems, but otherwise
correspond in structure. The form with larger stems and coarser
tubes is found in the upper Helderberg limestones of Michigan,
but particularly well preserved in the limestones of the Falls of the
Ohio, and at Charleston Landing, in Indiana. The smaller form
of more delicate structure is peculiar to the Hamilton group, and is
found at Thunder Bav, often also in the drift associated with other
Hamilton fossils.

Plate XH. — Fig. i represents a silicified specimen from the Falls
of the Ohio, with unusually well-preserved surface characters ; the
central figure in the second row of the plate is a similar specimen of
smaller size, and the two stems to the left of it are silicified speci-
mens of the smaller variety, found in the Hamilton strata of
Alpena. To the right of the central figure the upper fragment
represents a horizontal section through a specimen formed of tube
casts, narrowed by incrassation of the walls, and connected by radiaj
branches, which are the casts of the lateral pore channels. The
lower figure is a vertical section through a similar specimen, in the
peripheral parts likewise presenting the tube casts in a lateral
view ; the centre of the specimen presents not casts, but the actual
tube channels, intersected by transverse diaphragms, and in unal-
tered, not incrassatc condition. The outer lower stem is a speci-
men with abnormally incrassatc tube walls, to show the contrast in
external appearance of various modifications of the species.

FAVOSITES LIMITARIS, N. Spec.

Ramified and reticulated stems, from five to fifteen millimeters
in thickness, forming horizontally explanatc expansions or erect

PALA^IONTOLOG W 35

fruticose ramifications. Tubes very thick-walled, opening nearly
rectangularly to the surface, with circular orifices, the walls form-
ing either a solid, undefined interstitial mass, or, in another state
of preservation, the polygonal outlines of each tube are visible
on the surface of the interstices as delicate engraved lines. Sev-
eral varieties are observed, in regard to the mode of growth
and the size of tubes. The tube orifices rarely exceed the diam-
eter of one millimeter; often they are smaller, and in some forms
they are all equal in a specimen ; others have smaller and larger
orifices intermingled. A part of the orifices on the side faces of the
stems are often found closed by opercula, situated below the outer
edge of the channels ; in the interior parts of the tube channels
diaphragms are not regularly developed, and are of rare occurrence.
Pores large, distant, and irregularly dispersed. In older stems the
tube channels not unfrequently become considerably narrowed by
excessive incrassation of the tube walls, while the pore channels gain
in length and width, and appear on the surface as vermicular, trans-
verse channels connecting the tube channels, which latter are, in
their narrowed condition, hardly larger than the connecting pore
channels. In certain specimens the orifices are at a slightly oblique
angle to the surface, and surrounded at the lower external rim by-
a raised margin, which approximates this species to the forms of
Favositoids comprehended under the name Cladopora, in indication
of which similarity of structure I selected for it the name liinitaris,.
a ^^ joining, transitory fonnr

The different well-marked varieties, which I have considered as
constituting one species, are found in the corniferous limestone of
Michigan, Canada, New York, Indiana, and Kentucky, usually in
silicified condition ; finely preserved specimens are also found in the
drift deposits of Michigan.

Plate XIII. represents four varieties of the species. Fig. i is the
usual form found in the drift ; it is likewise the most common variety
in the corniferous strata of Canada West (Port Colborne) and
at Caledonia, N. Y. The faintly developed lips at the lower mar-
gins of the orifices are perceptible in the figures, and in one speci-
men the sharply defined polygonal outlines of each tube are also
plainly seen. Fig. 2 is found in the drift of Ann Arbor ; stems
erect, with fruticose ramification ; tubes smaller than in the former
variety. Fig. 3 grows in much stouter branches than the others ;

36 LOWER PENINSULA.

the stems are usually compressed, elliptical in circumference ; ori-
fices very unequal in size. The portrayed specimen is from the Falls
of the Ohio, but the same form is also found in the upper limestones
of Mackinac Island. Fig. 4 resembles closely form No. 3, and occurs
in association with it at the Falls of the Ohio ; its tubes and stems
are in all their proportions smaller. On Plate X. casts of this species
are represented (Fig. 3) as they occur in the drift. The conical, sub-
angular form of the tube channels, the almost total absence of dia-
phragms, the dispersed position of the pores, and the mode of
gemmation of one tube from the other, are plainly conspicuous in
the figures.

FAVOSITES CLAUSUS, N. Spec.

Clustered, rapidly branching and anastomosing flexuose stems,
varying from one half to one centimeter in thickness. Tubes
unequal, the larger ones circular, measuring in different specimens
from one half to one and a half millimeter in diameter ; the
smaller tubes filling the interstices between the larger ones are
subangular. Orifices at the ends of the branches all open ; on the
sides of the stems most of them are found closed by opercula.
Opercula flat or convex, some of them decorated with twelve
marginal carinas radiating toward the centre. Diaphragms partly
simple and regular, but largely intermingled with irregular partial
septa, formed by the development of lateral squamae analogous to
the vertical rows of leaflets in other species of Favosites. Pores
numerous. Under this species I comprehend several varieties
which closely resemble each other in general structure and mode
of growth, but which may possibly be distinct forms. They occur
in the Hamilton group and in the corniferous limestone.

Plate XIV. — Upper left-hand figure represents a silicified speci-
men from the Hamilton group of Thunder Bay River, near Broad-
well's mills. Similar ramifications arc found in the Hamilton strata
of Widder and Arcona, in Canada. The tubes of this form are
smaller than in the forms of the Helderbcrg group. The right-hand
specimen in the upper row of the plate is from the corniferous
limestone found in the drift of Ann Arbor ; its tubes are nearly all
of equal size and closed by opercula.

In the left-hand figure in the lower row, from the Falls of the Ohio,

PALAEONTOLOGY.

2>1

the large circular tubes are in great contrast with the smaller sub-
angular ones. The right-hand lower figures are single branches from
the usual variety occurring in the corniferous limestone of Michigan,
Canada, New York, and in the Western States. The specimens
selected are also from the Falls of the Ohio.

FAVOSITES INTERTEXTUS, N. Spec.

Irregularly reticulated masses of cylindrical or compressed
elliptical stems, from one to two centimeters in thickness. Tubes
quite unequal, stout-walled, the larger ones circular, the smaller
subangular, filling the interstitial space between the larger tubes.
Size of the larger tubes not much over half a millimeter. In the
centre of the stems the tube channels are regularly formed, with
moderately thick walls, and intersected by complete or incom-
plete squamiform diaphragms, and connected by distant pores.
In the peripheral portions of the stems, the tube channels, by
habitual thickening of the walls, have shrunk to filiform thin-
ness, while the lateral pores have become more profusely de-
veloped and equal in width to the shrunken tube channels. Here-
by a network of anastomosing ducts is formed, which can not
be properly observed in fully-preserved specimens ; in the drift,
however, weathered specimens frequently occur in which the
casts only of these reticulated ducts are preserved in silicified con-
dition, the wall substance having all decayed. No one would
likely recognize in these networks the casts of a Favosites if parts
of the fully-preserved coral were not found in immediate contiguity
to such networks. The contracted tube channels usually expand
again to their normal diameter in close proximity to the surface.
Found in the upper limestones of Mackinac and in the drift of the
Lower Peninsula.

Plate XV. — Fig. i represents reticulated tube casts with the central
portions of the stems formed by normally shaped tube channels.
The object is too minute in the specimen. On Plate X., Fig. 4,
similar casts of somewhat coarser stems are represented. On Plate
XV. the upper left-hand figure is a palmate branch found in the
drift of Ann Arbor ; some specimens have much stouter stems,
while others are only of the thickness of a lead-pencil, forming retic-
ulated clusters.

38 LOWER PEXIXSULA.

FAVOSITES DIGITATUS. X. Sp.

Cespitose masses of subparallel anastomosing stems of the thick-
ness of a finger, or single stems with more straddling branches.
Tube walls stout, joining under polygonal outlines, lined by a
cycle of vertical rows of horizontal squamae, usually fewer in num-
ber than the normal twelve. Diaphragms sometimes regular, fre-
quently incomplete, replaced by the lateral squamse. Pores large.
Tubes in different specimens variable, from one to one and a half
millimeter in diameter. The polygonal form of the orifices and the
generally well-developed squamae within the tube channels render
this form at once recognizable from other branching forms of
Favosites. which have their orifices always more rounded, nearly
circular.

It occurs in large clustered masses in the black, shaly lime-
stones of the Hamilton group, on the shore of Lake Huron, from
Thunder Bay Island, northward : similar masses are inclosed within
the limestones of Little Traverse Bay, in beds of various horizons,
and preser\'ed in calcified condition. On Thunder Bay River it is
found in silicified condition in the lower beds near Trowbridge's
mills ; in the drift of the Lower Peninsula, also, silicified specimens
associated with other characteristic Hamilton fossils can often be
picked up.

On Plate XV.. the six right-hand figures of the lower row are
silicified specimens, of various tube size. The two outer figures
and the lower central branch are from the drift of Ann Arbor :
the other three branches are from the north fork of Thunder Bay
River : the lower small branch has considerably thickened tube
walls, forming within the polygonal, truncate, disciform tube ends
a central proboscis-like prolongation. The cespitose specimens
from the dark limestones, from the shore of Lake Huron and from
Little Traverse Bay, can not be successfully represented by photog-
raphy on account of their sombre color.

ALVEOLITES, Lamark.

Massive convex or expanded laminar, rarely ramose, polyparia,
composed of intimately united, compressed tubules, intersected
by transverse diaphragms, connected by lateral pores, and longi-

PALAEONTOLOGY. 39

tudinally crested on the inside. The tubes in the massive or
laminar forms are prostrate, diverging from a central point, and
open obhquely to the surface ; in the ramose forms the tubes are
ascending and arching outward from an imaginary central axis, as
in branching forms of Favosites. Tube walls moderately stout
and not expanded at the orifices, the inner margin of which is
appressed to the body of the polyparium and lost in a common
interstitial surface ; the outer margin projects as a sharp lip. Cav-
ities of tubes lined with longitudinal crests or rows of spinulose
projections, which normally should be twelve in number, but it is
rarely the case that all of them are found developed. Usually two
or three of the crests, or crested rows of spinules, grow large and
conspicuous ; the others have a more rudimentar}' development.
or have sometimes become obsolete. Diaphragms comparatively
more distant and irregular than in Favosites. Pores x&ry large, sit-
uated on the two lateral edges of the compressed tubes, or at least
in close proximity to them. The genus Alveolites appears contem-
poraneously with Favosites, for the first time, in the upper Silurian
strata.

ALVEOLITES XL\GARENSIS, X. Sp.

Convex hemispherical masses of concentrically laminated structure,
covered by an epithecal crust on the lower concave side, or undose,
discoid expansions composed of superimposed layers of prostrate
tubes, diverging with a slight spiral twist from a central vertex, sev-
eral of which are sometimes observed on an expansion. The com-
pressed tubes are always more convex on the upper sides, with a
corresponding concavity of the lower sides, which rest on the con-
vexities of the subjacent tubes. The compression is sometimes
only moderate, and the outside of the oblique orifices is formed by
a projecting arched lip ; in other specimens the compression is
stronger, the orifices become narrow, lanceolate, or fissure-like,
with an appressed subplane lip on the outer side. The orifices of
the majority of specimens are surrounded by a cycle of denticules,
corresponding to longitudinal rows of spinules along the inner sur-
face of the tube walls. The rows are rarely fully twelve in num-
ber, and some of them are always more strongly developed than
others. In some specimens no denticulation of the orifices can be

40

LOWER PENINSULA.

observed, and the tube channels are found to be almost smooth ;
this is not in all cases owing to a want of development of the crests
or spinules ; these seem often to have been obliterated by im-
perfect preservation in the process of petrification.

Diaphragms somewhat distant and oblique. Pores large, margi-
nal, causing a pouch-like dilatation of the tube wall at the spot
•where situated. Diameter of tubes in the wider transverse direction
varies in different specimens, from a half to one millimeter, which
difference in size greatly alters their aspect. The degree of com-
pression of the tubes, their more erect or more prostrate position in
various specimens also cause numerous variations in their appear-
ance, but no tangible line between one and another of the forms
exists. I have, for this reason, considered all of them as repre-
senting the modifications of one and the same species. It occurs
in great abundance in the Niagara group of Drummond's Island,
at Point Detour, and in other localities. It is often found also in
the drift of the Lower Peninsula. The specimens are all silicified,
and in but few of them are the more delicate structural characters
well preserved. Certain specimens found in the drift exhibit prin-
cipally the silicified casts of the tube channels, which have the form
of flattened bands with rounded mamiform protrusions and inter-
mediate indentations of the lateral margins ; on the summit of each
protrusion a pore channel or its cast is situated.

Plate XVI. — Fig. i represents a silicified specimen from the drift
of Ann Arbor, Fig. 2 is found at Drummond's Island. The latter
specimen exhibits the longitudinal rows of spinules very distinctly,
but the object is too small to be properly seen in the not magni-

fied figure.

PALjEONTOLOG Y. 4 1

ALVEOLITES SQUAMOSUS, Billing?.

Convex masses of irregular growth, covered by an epithecal crust
on the partially free, centrally attached under side, or sometimes
incrusting other marine bodies. Tubes in the broader, transverse
direction from one half to one millimeter in diameter, and in the
other direction quite variable, in accordance with the degree of
depression of the tubes, which are convex on the upper side and
concave on the lower. Orifices very oblique, with a sharp lip on
the outer margin. Tube channels longitudinally crested by twelve
well-developed rows of spinules, of which generally some are larger
than the others. Diaphragms not very close, and irregularly
oblique. Pores large, marginal, but not causing a pouch-like dilata-
tion of the tubes as in the Niagara species.

Found in the upper Helderberg limestones of Michigan, and in
the drift ; common also in the Helderberg limestones of Canada,
New York, Ohio, Louisville, etc.

On Plate XVL, Fig. 3 is a silicified specimen found in the drift,
giving a surface view ; Fig. 4, likewise found in the drift, is com-
posed of casts of the tubes. They are delicately punctured by im-
pressions of the longitudinal rows of spinules. They exhibit the
laterally situated pores and the distant, irregular diaphragms. The
figures are of natural size.

ALVEOLITES VALLORUM, Meek.

(Palaeontology of Mackenzie River.)

Specimens resembling the forms described by Mr. Meek, from
Mackenzie River, are frequently found among the drift pebbles of
Lake Superior. In some of them the tube walls are preserved ;
in others only the casts of the tube channels, which have the form
of narrow, flat bands, connected with each other by short marginal
bridges, representing the pore channels. The bands are longitudi-
nally striate by fine, punctiform impressions, and transversely inter-
sected by numerous closely approximated diaphragms. The width
of the tube casts is about one millimeter, and their thickness one
fourth of a millimeter.

42 LOWER PENINSULA.

Plate XVII. — Fig. 3 is a silicified specimen split in two, formed
of tube casts. Found on the shore of Lake Superior, at White-
fish Point. Among the pebbles of the same locality other speci-
mens of Alveolites are found, which agree with Alveolites squa-
mosus, Billings.

ALVEOLITES SUBRAMOSUS, N. Sp.

Incrusting expansions of irregular form, dependent from the in-
crusted object in the first stages of growth, subsequently of mamil-
late or digitato-ramose form. Orifices not over half a millimeter
wide, margined on the outer side with a convex projecting or a
flattened appressed lip ; denticulated by crests, one of which in the
median line of the inner body side of the tubes is much more promi-
nent than the others. Pores large, rather remote. Diaphragms
distant. Found in the Hamilton group of Thunder Bay, at Stony
Point, and other localities. In mode of growth it perfectly resem-
bles the branchlets from the Devonian strata of the Eifel, described
by Milne-Edwards under the name of Alveolites subequalis, but its
tubes are more minute and more strongly compressed than in that
form.

Plate XVIII. — Fig. 4 represents calcified specimens from Stony
Point, Thunder Bay, etc.

ALVEOLITES GOLDFUSSII, Billings.

Undose, discoid expansions, with an imperfectly developed epi-
theca on the lower side, exhibiting the prostrate tube walls diverg-
ing from a central point of attachment. Orifices oblique to the
surface, rarely denticulated at the margins, but interiorly, spinulose
longitudinal crests are found well developed in polished sections.
The tubes are seen in various degrees of compression in the same
specimens ; usually their transverse diameter is twice larger than
their height, but sometimes tubes nearly as wide in one direction as
in the other, and almost erect, as in an ordinary Favosites, can be
observed. The size of the. tubes is larger than in Alveolites squa-
mosus, measuring in the larger diameter from one and a half to two
millimeters.

PAL.^ONTOLOG V.

43

Pores large, situated on the lateral edges of the tubes. Diaphragms
well developed, irregularly oblique or straight transverse. Found
in the Hamilton strata, of Thunder Bay region, near Sunken Lake ;
more common in the Hamilton group of Widder, C. W., and in
the Hamilton strata of Iowa.

Plate XVn. — Fig. 2 gives a surface view of part of a specimen
from Widder, C. W.

LIMARIA STEININGER.
Synon,, Ccenites Eichwald.

«

Small branching stems or laminar expansions, composed of thick-
walled, conico-cylindrical tubules, with transversely compressed
orifices, opening obliquely to the surface, surrounded on the outer
side by an exsinuated lip, bearing two teeth projecting into the
cavity. From the median line of the inner side of the walls,
another tooth-like crest projects between the two outer ones. The
tubes are connected by lateral pores, and intersected by transverse
diaphragms. The diaphragms are regularly found in the thin-
walled tube portions, but are rarely developed in tubes with
thickened walls.

From Alveolitestiimaria iiss-differs only by more conical, stout-
walled tubes, of less compressed and more rounded form in the
central or basal parts of the polyparia. The number of longi-
tudinal crests is in Limaria more restricted than in Alveolites, and
rarely exceeds three. The three dentiform projections at the
orifices of Limaria are the only structural difference separating it
from the genus Cladopora, which has smooth, not crested tube
channels ; there are also, however, in species of Cladopora indi-
cations of crests, and the generic arrangement of many of the spe-
cies in question is more a matter of individual arbitration than based
upon any obvious typical difference.

LIMARIA RAMULOSA, Hall.

Found in the Niagara group of Lockport, etc. I have not been
able to find it in Michigan. Another form of ramulets, which, accord-
ing to the denticulated structure of their tube orifices, belong to the

44 LOWER PENINSULA.

genus Limaria, is Cladopo7'a vcrticillata of Winchell and Marcy.
It is of common occurrence in the Niagara group of Indiana, Wis-
consin, and Kentucky, but has not been met with in Michigan.

LIMARIA LAMINATA, Hall.

Thin, undose, laminar expansions covered by an epithecal crust
on the lower side. Tubes stout-walled, forming a massive inter-
stitial surface between the orifices, which is sometimes larger than
a tube diameter, other times less. Orifices, if well formed, crescent-
shaped and less than half a millimeter in diameter. The convex
side of the crescent forms a more or less projecting lip, with two
rather obscure, dentiform crests ; on the concave side of the cres-
cent another more conspicuous crest occupies the median line. The
specimens exhibit on their surface at various intervals certain
centres, around which the orifices are disposed in spirally twisted
rows ; the concave sides of the orifices are always directed toward
these imaginary central points. Of common occurrence in the Ni-
agara group of Drummond's Island, and at Point Detour, but many
of the specimens have by silicification lost the finer details of
structure.

Plate XVIII. — Fig. 2 lepresents a specimen from Point Detour,
of natural size.

LIMARIA CRASSA, N. Sp.

Grows in thick, laminar expansions, of undose surface, covered on
the lower side by an epitheca. Often several such laminae are su-
perimposed, and sometimes two leaves stick together at the epithe-
cal side, and a lamina with orifices on both sides is the result.
Orifices variable in the same specimens. If normally formed they
are kidney-shaped, separated by massive interstitial spaces formed
by the thick tube walls. They open obliquely to the surface, with a
lip on the outer margin. In other tubes the lip scarcely projects,
and the orifices appear as an unsymmetrically oval opening sur-
rounded by a massive interstitial surface. Often, also, the tubes are
joined, with nearly erect, subangular, less thick-walled orifices. On
the inner side of the walls a conspicuous crest projects from the
median line, and on the outer walls two others of smaller size fork

PALJEON TO LOG Y. 45

over the opposite one; by a great thickening of the walls, the crests
become obsolete. Pores are large and numerous. Diaphragms
developed in the thinner-walled tubes. Found in the Niagara
limestone of Point Detour, Drummond's Island, and in the expo-
sures of the Niagara group along the shore of Lake Michigan, in
the west part of the Upper Peninsula.

Plate XVIII. — Fig. i represents fragments from Point of Barques,
on Lake Michigan (southwest of the mouth of Manistic River).

CLADOPORA, Hall.

Ramose and anastomosing stems or laminar expansions, witli
orifices on one or both sides, composed of thick-walled, elongate,
conical tubules, opening obliquely to the surface, with dilated
orifices. Tubules laterally connected by pores. Diaphragms have
originally been denied by the author in his genus Cladopora, but
their occasional development is proved by many actual observa-
tions, although usually the tube channels, in specimens, are found
open throughout all their length.

The tube cavity of Cladopora is said to be destitute of longitu-
dinal furrows or crests, in distinction from Limaria and Striatopora,
but this is merely through habitual obsolescence of a character
which properly belongs to the entire Favositoid family, and which
in some of the most characteristic species of Cladopora has been
recognized in rudimentary development.

CLADOPORA LAOUEATA, N. Sp.

Large, reticulated, horizontal expansions, formed of round or com-
pressed elliptical stems, from two to four millimeters in diameter,
with narrow, intervening loops of elongate, lanceolate form. Tubes
very thick-walled. Orifices separated by broad interstitial spaces,
transversely oval, somewhat dilated, nearly one millimeter wide in
transverse direction, with a stout lip on the exterior margin ; the in-
terior margin impressed and confluent with the massive interstitial
surface. Pores plainly discernible. Diaphragms sometimes notice-
able, closing off the peripheral tube ends. By silicification the finer
surface details of the specimens are generally much impaired.

46 LOWER PENINSULA.

Occurs in the Niagara group of Point Detour, and all along the
exposures of the south shore of the Upper Peninsula.

Plate XVIII. — Fig. 3 represents a fragment of a large expansion
in silicified condition. Found near Seul Choix, on shore of Lake
Michigan. In mode of growth this species bears much resemblance
to Cladopora reticulata, Hall ; but the latter is a more delicately-
built species, with smaller, nearly circular tube orifices.

In the drift deposits of Michigan, specimens of Cladopora uiultipora,
Hall, are often met with.

CLADOPORA LICHENOIDES, N. Sp.

Irregularly undose, laminar expansions, covered by an epithecal
crust on the lower side, which is formed by prostrate, flattened
tubes, coalesced intimately and diverging horizontally from a cen-
tral apex. Toward their peripheral ends the tubes bend into a
suberect position and lose their flattened form, becoming rounded
and dilated near the orifices. These are sometimes nearly upright,
and join with acute margins, resembling an ordinary Favosites ; at
other times the obliquity of the orifices is more pronounced, and the
outer tube margins form an arched projecting lip, while the inner
margin merges into a narrow, common, interstitial surface. The
flattened tubes, forming the base of the expansions, connect by nu-
merous lateral pores situated on both edges ; the erect, more
rounded portions of the tubes have the pores irregularly dispersed
over their circumference.

Diaphragms sparingly developed at irregular, remote intervals,
often closing the peripheral tube ends, under the form of opercula.
The tube cavity is generally smooth, without crests or longitudinal
furrows, which induced me to place this species with Cladopora, and
not with Alveolites, under which it might otherwise be classed
with propriety. Found frequently in the drift of Michigan. It
occurs in place in the corniferous limestone of the Falls of the Ohio,
in Canada and New York, etc.

Plate XVII. — Fig. 1 gives a surface view of silicified specimens
from the Falls of the Ohio. P^ig. 4 is a specimen found in the drift
of Ann Arbor, exhibiting the casts of tubes seen from the basal side
of an expansion. The flattened form of the prostrate channels,
with numerous short marginal pore connections, the gemmation of

PAL.^EONTOLOG Y.

47

young tubes from older ones, the disposition of distant diaphragms,
the more rounded and dilating peripheral tube ends, bent into sub-
erect position — all can be studied in such casts to much better ad-
vantage than in the most perfectly preserved specimens.

CLADOPORA FISHERI, Billings.
Synon., ALVEOLITES Fisheri, Billings.

Palmate, laminar expansions, attached by a clumsy, massive root
portion to other bodies. Orifices on both sides of the leaves, open-
ing obliquely to the surface, with a sharp lip on the exterior side ;
the inner tube margin merges into a common interstitial surface, of
variably broader or narrower extent. The thickness of the tube
walls and the obliquity of the orifices vary much in different parts
of the specimens, and accordingly the surface characters are quite
changeable. On the terminal edges of the fronds the tubes
are thin-walled and the orifices join with sharp, crested outlines.
In the central and basal portions of the expansions, the walls
are thickened, and the oblique orifices separated by intervening
solid interstitial spaces, margined on the exterior side by a lip,
which surrounds a transversely oval, or often a nearly circular
mouth. Sometimes the orifices are not lipped, and form shallow,
undefined depressions in the massive wall substance, at the bot-
tom of which the narrower part of the tube channels begins. Again,
these superficial pits are circumscribed by polygonal, carinated out-
lines. A difference also exists in the upper and lower surfaces of
the fronds, v/hich seem to have grown in horizontally spreading
direction. The upper side is always marked by sharper, more pro-
jecting contour lines, while on the lower surface all the contours
are dull and rounded.

The orifices are about one half a millimeter wide, or somewhat
larger, oval or kidney-shaped on the external margin ; the inner tube
portions are round or subangular. Pore channels are large and
numerous. Diaphragms frequently developed under the form of
superficial opercula, frequently noticed also in the inner portions of
the tube channels, but in specimens with very stout-walled tubes
rarely observed. The original specimens described by Billings were
found in the Hamilton group of Widder, C. W., in calcified con-

48 LOWER PENINSULA,

dition ; identical, but silicified specimens occur in the Hamilton
group of Thunder Bay, and in boulders of the drift which inclose
other characteristic Hamilton fossils. Entirely similar specimens
are found in the corniferous limestone of the Falls of the Ohio, and
at Charleston Landing, Indiana.

Plate XIX. — Fig. i represents a silicified specimen from the drift
of Ann Arbor. Fig. 4 is a specimen from the Hamilton group of
Widder, C. W., the typical locality for Mr. Billings' specimens.

CLADOPORA CANADENSIS, N. Sp.

Palmate, laminar expansions, like the former species, with which
it is found associated and agreeing in general structure. Tubes
much smaller. Orifices at the ends of the fronds subrotund or trian-
gular, with a convex, centrally indented lip on the outer side. On
the stouter central and basal parts of the expansions, the lips are
appressed, opening, transversal, fissure-like, or the lips have, besides
the central indentation, two lateral ones, giving the orifices an arched,
semi-lunar form. On the under side of the fronds the orifices are
impressed into the massive interstitial wall substance, with a shal-
low depressed space surrounding them, which is defined by very
obtuse rounded, subpolygonal outlines. On the upper surface, all is
raised into stronger relief. Found in the Hamilton group of Wid-
der, C. W.

Plate XIX. — Fig. 3 is a representation of one of these speci-
mens.

CLADOPORA TURGIDA, N. Sp.

Stout laminar expansions, with orifices on both sides. Tubes
thick-walled, with a narrow cylindrical channel, which dilates near
the surface into transversely oval or kidney-shaped oblique orifices,
spreading, with the inner part of the margins, into a common inter-
stitial surface, on which, by slightly raised carinas, the polygonal out-
lines of each tube are defined. The outer margin projects as a
short lip sinuated on both sides, or simply straight. In well-pre-
served specimens, on the expanded part of the orifices, longitudinal
furrows are faintly developed, as in the genus Striatopora. A differ-
ence is noticeable between the upper and under side of the fronds.

PALAEONTOLOGY, 49

Pores well developed. Diaphragms rarely observed excepting as
opercula. Diameter of orifice a little over one millimeter ; internal
tube portions half a millimeter. Found in the Helderberg group
of Mackinac Island, at Port Colborne, C. W., and likewise in the
drift of Ann Arbor.

Plate XIX. — Fig. 2js a silicified fragment found in the drift Ot
Ann Arbor.

CLADOPORA CRYPTODENS, Billings.

Alveolites cryptodens, Billings.

Cylindrical polyp stems, from five to ten millimeters in diameter,
with distant, dichotomous, straddling ramification. Tubes opening
with oblique dilated orifices, w'hich either join with acute edges,
each of them being a circumscribed pit, or have the inner part of
the walls spread into an indefined, common interstitial surface, from
which the convex lips forming the front margin of the orifices pro-
ject like the teeth of a rasp. Tube size variable in different speci-
mens ; in the variety with larger tubes the transverse diameter of
the dilated orifices is about one and a half millimeter, the interior
cavity of the channels measuring about a half of one millimeter.
In the variety with smaller tubes the orifices measure about one
millimeter externally, and the internal channels one third of a milli-
meter. The tube cavities usually appear to be smooth, but in well-
preserved silicified specimens, cleared by acids of the surrounding
limestone, the tube channels exhibit three crests, two projecting
from the exterior side of the wall, and one intermediate between
the two, from the opposite inner wall side. These crests are not
noticeable on the dilated orificial part of the tubes, but are distinctly
seen in the neck of the channel, where .the narrower part begins.
Transverse diaphragms are rarely found developed. Pores arc
large and irregularly dispersed. The crested condition of the
tube channels would bring this species under the genus Limaria,
or perhaps under Alveolites, where Billings placed it, but, consider-
ing the general habitus of the specimens, I have placed them under
Cladopora, as being nearest related to the forms composing this
genus, which is only deprived of crests through the incomplete dc-
4

50 LOWER PENINSULA,

velopment of a character typical for the whole family to which it
belongs.

Found in the upper Helderberg limestones of Michigan, New
York, Canada, and in the Western States ; also common in the drift
deposits of Michigan.

Plate XX. — Fig. i represents several fragments of branches with
the larger tubes. Orifices somewhat variable in different branches.
Fig. 2 is the variety with smaller tubes, corresponding in all partic-
ulars with the larger tubed form. All the specimens figured are
selected from the Falls of the Ohio, as being better preserved than
those from any other locality.

CLADOPORA ROEMERI, Billings, i
Alveolites Roemeri, Billings.

Cylindrical or compressed branching stems of about five millime-
ters diameter. Orifices comparatively large, oblique to the surface,
and joining with their expanded margins in an indefined interstitial
surface, or under subangular, obtusely crested outlines, inclosing
shallow, obliquely funnel-shaped pits, the outer margins of which
project as arched lips ; the inner walls of the pits spread insensibly,
merging into the lips of the adjoining pits. External diameter of
orifices about one millimeter; interior tube channel one third of a
millimeter. The orifices are frequently closed by opercula situated
below the external margins. Diaphragms in most of the specimens
sparingly developed. Pores large and irregularly disposed.

Occurs in the Hamilton strata of Widder, Canada West, in cal-
cified condition. Silicified specimens are found in the corniferous
limestone and in boulders of that formation, mingled with the
drift of the Southern Peninsula.

Plate XX. — Fig. 3 represents specimens from the typical locality
of Widder, Canada West.

CLADOPORA ALPENENSIS, N. Sp.

Branching cylindrical stems, from five to ten millimeters in
diameter. Orifices slightly oblique, dilated, joining under [linear
polygonal outlines on an even, narrow, interstitial surface ; external

PAL^ONTOLOG V. 5 1

margins not projecting as a lip, excepting a small nodular projec-
tion in the centre of the outer margin, which gives the transversely-
widened, elliptical mouths a faint kidney shape. The inner expanded
margin of the orifices is very delicately striate in radial direction.
Diameter of orifices externally about one millimeter ; internal tube
cavity about half a millimeter wide. Diaphragms rarely noticed.
Pores large and irregularly dispersed.

Found in silicified condition in the upper strata of the Hamilton
group of Thunder Bay.

Plate XX. — Fig. 4 represents a few of the branchlets. The linear
polygonal outlines of the tubes are recognizable in the figures ; the
striation of the margins is too delicate to be seen on them.

CLADOPORA LABIOSA, Billings.

Alveolites labiosa, Billings.

Small, branching, reticulated stems, from two to five millimeters,
in diameter, growing from an attached, massive root portion in hori-
zontally spreading direction. Orifices oblique to the surface, sub--
circular, surrounded on the exterior side by a prominent convex
lip ; the interior part of the orificial tube walls spreads into an un-
defined, flat, interstitial surface. By wearing of the surface the lips,
often become deeply sinuated in the [centre, and then the orifices
are acutely triangular. In certain specimens considered to be a
variety of this species, the' closely crowded small orifices are sur-
rounded by small pits impressed in the thick wall substance and
open on the surface with less obliquity than in other specimens,,
and with only a small lip developed^ on the exterior margin. The
size of the tubes differs somewhat in the specimens, but a mioreob-
vious difference in appearance is caused by the variations in the
width of the interstitial spaces. In some specimens the orifices are
separated by interstices less than the diameter of a tube,, while in
others the interstitial space is two or three times as large. In
adult parts of stems the intervals between the orifices are always
greater than they are near the terminal branchlets. The diameter
of tubules at the orifices is about half of one millimeter ; internally
the channels are narrower. Within the cavity of some tubes, on
the outer side of the walls, two crests can be noticed by looking into

52

LOWER PENINSULA.

the orifices, but in others of equally well-preserved specimens no
crests are recognizable. Lateral pores well developed. Transverse
diaphragms have not been observed. The casts of tubes often
found in drift specimens are always uninterrupted, thread-like, lat-
erally connected by short transverse bars representing the pores, and
exhibiting the intercalation of new young tubules, connecting by a
perforation at the apex with their mother-tubes.

Found abundantly in the drift of Michigan, in a porous cherty
rock containing many other corniferous limestone fossils. In Canada
and New York it is common in the corniferous limestone ; occurs
also at the Falls of the Ohio.

Plate XXI. — Fig. 2 represents a number of branchlets of variable
form. The two lower figures on the left side are excepted ; they
are described under the name of Cladopora rimosa ; but in the lower
tier of this plate the smaller central specimen is considered as a
variety of Cladopoi'a labiosa.

CLADOPORA RIMOSA, N. Sp.

Reticulated expansions of small teretiform or elliptically com-
pressed stems, much resembling the former species. Orifice openings
very oblique to the surface, transversely compressed, fissure-like,
margined by a sharp closely-appressed lip on the outer side. Di-
ameter of orifices in transverse direction from one half to two thirds
of a millimeter ; interior tube channels cylindrical and much nar-
rower. Interstitial spaces large and flat. This form is the usual
associate of Cladopora labiosa, and may perhaps be only a variety
of that species ; but the two forms are so constant, not merging into
one another through transition forms, that I believe them to be dis-
tinct. Found in the drift of the Lower Peninsula.

Plate XXI. — Fig. 2, the two lower left-hand stems. The
larger forked specimen is broken off from a disciform basal expan-
sion incrusting the stem of a Cyathophyllum Hallii.

CLADOPORA PINGUIS, N. Sp.

Horizontally expanded, branching and anastomosing stems of
usually compressed elliptical form, but sometimes cylindrical. Di-
ameter of stems from five to ten millimeters. Orifices in the older

PAL.'EONTOLOG \\

53

stems subreniform shallow pits, impressed into a massive common
wall substance, composing broad interstitial spaces. The actual tube
opening, commencing at the bottom of these pits, is narrow, fissure-
like, and margined by a small lip which does not project above the pit.
In the ends of the branches the tube walls are less thickened, and the
orifices not surrounded by pits, subcircular, margined by a moder-
ately projecting convex lip. These terminal parts of the ramifica-
tions resemble the specimens figured as Clad, labiosa. The three
right-hand branchlets and future ^collections may demonstrate the
three last-described species to be only modifications of one ; but
for the present this direct affinity between them is not proved, where-
fore I point them out as specifically distinct. Found associated
with the other forms in the drift of the Lower Peninsula.

Plate XXI., Lower tier. — The two larger specimens were found
in the drift of Ann Arbor, in a porous cherty rock, originating from
decomposition of a siliceous limestone, of which sometimes an
unaltered nucleus forms the centre of the boulders. The specimen
in the centre below the two figures represents a variety of Clado-
pora labiosa.

CLADOPORA PULCHRA, N. Sp.

Small cylindrical stems, from three to five millimeters in thick-
ness, growing in reticulated ramifications, composed of thick-walled
conical tubules, diverging in a curve from an imaginary longitudi-
nal axis, opening almost at a rectangle to the surface, with circular
orifices separated by interstitial walls wider than a tube diameter.
The end of each tube either projects as a small monticulose protu-
berance above the general surface, and is defined from the adjoining
tubes by delicate linear furrows circumscribing polygons, or the
lower half only of each tube wall projects under the form of a low
semicircular lip. In other specimens the single ends of the tubes
do not project, and are not defined in their circumference, their
orifices opening on the massive surface as simple circular perfora-
tions, surrounded at the outside by a shallow'depressed area. Tube
diameter at the orifices one third to one half millimeter, near the
centre of the stems much narrower. Lateral pores numerous, in un-
equally dispersed position. Diaphragms sparingly developed. On
the casts of the tubes which frequently occur in weathered drift

54 LOWER PENINSULA.

specimens, a cycle of longitudinal carinations is faintly visible. In
its structure this elegant small species approaches Favosites limi-
taris, which could likewise be not inappropriately arranged under
the genus Cladopora. The thick-walled conical tubes, the greater
obliquity of the orifices to the surface, with a sometimes well-de-
veloped prominent lip, bring this form nearer to the Cladopora type
than to Favosites. Very common in the drift boulders of the cor-
niferous formation in Michigan ; it occurs in place in the Helderberg
limestones of Canada, and at the Falls of the Ohio, near Louisville.
Plate XXI. — Fig. i represents a number of variations, amongst
which are found stems with smaller tubes and with larger tubes,
with projecting monticulose orifices and with lipped mouths, or
with massive surface of the stems, with the orifices impressed as
shallow pits. Some of the stems represented exhibit also sharp,
linear, polygonal furrows circumscribing the tubes.

CLADOPORA ROBUSTA, N. Sp.

Palmato-ramose, occasionally reticulated stems, of round or com-
pressed elliptical form, growing in horizontal expansions, spreading
sometimes over the space of several square feet. Stems attaining a
thickness of from one to two centimeters. Tube openings oblique
to the surface, with gently dilating orifices, joining under subacute
margins, by which the surface is divided into a network of rhom-
boidal spaces with rounded corners. The lower angle of the rhom-
boids is formed by the projecting semicircular lips of the orifices,
which, by wearing off, become emarginated and acutely triangular
in shape. Transverse diameter of orifices about one millimeter,
in other varieties smaller. Diameter of tube channels below the pe-
ripheral surface one quarter to one half of a millimeter. Tube walls
stout, thickening near the periphery. Lateral pores distant. Dia-
phragms sometimes observed, but not developed in the majority of
the specimens. Several varieties, in manner of growth and size of
tubes, can be distinguished.

Found in the corniferous limestone and in the Hamilton group.
The Hamilton specimens occur in the vicinity of Alpena, on Thun-
der Bay ; the specimens of the corniferous strata are frequently
found in the drift of Michigan, but the P^alls of the Ohio is the lo-
cality where this species can be found in greatest perfection and in

PALAEONTOLOGY. 55

greatest abundance. The represented specimens are from that
locality.

Plate XXII. — Fig. i represents two silicified branches with larger
tubes. Fig. 2 is a branch of smaller tube size.

CLADOPORA IMBRICATA, N. Sp.

Cylindrical ramified stems, attaining a diameter of two centime-
ters, attached by a massive basal expansion. Tubes opening very
obliquely to the surface, with narrow, transversely compressed ori-
fices, joining under rhomboidal outlines. The sharp subarcuate
lips forming the exterior margin of the orifices are closely appressed
to the body of the stems, and arranged in an imbricating order like
the scales of a fish.

Transverse diameter of orifices two millimeters by a width of only
half a millimeter across the centre of the lanceolate mouths. Inter-
nally the tube cavity becomes nearly circular and much narrower,
not over half a millimeter in diameter. Pores distant. Dia-
phragms have not been observed. Some specimens found in the
drift of Michigan seem to belong to this species, which is not un-
common in the Helderberg limestones at the Falls of the Ohio.

On Plate XXII., lower row, the two outer stems on the right-
hand side are figures of silicified specimens found at the Falls of
the Ohio.

The next two species described, found in the Helderberg lime-
stones at the Falls of the Ohio, have not been recognized in the stra-
ta of Michigan, but in order to give the description of this tribe of
corals more completeness, I have allowed myself, in behalf of sci-
ence, to transgress a step beyond the prescribed limits. It is very
probable, however, that future collectors will find these forms in
Michigan.

'is*^

CLADOPORA ASPERA, N. Sp.

Cylindrical stems, from one to two centimeters in thickness, grow-
ing in horizontally spreading, reticulated ramifications, which are at-
tached by a massive basal expansion. The tubes composing the
basal part are prostrate, diverging toward the circumference of the
disk ; the orifices are compressed, fissure-like, covered by a scaly, fiat

56 LOWER PENINSULA.

lip, while the inner part of the walls forms an undefined, common
interstitial surface. The orifices of the stems are of quite different
shape ; their tubes diverge from an imaginary axal line in an
ascending curve toward the periphery of the stems, opening there
in various degrees of obliquity, under crested polygonal outlines
which inclose shallow conical pits, at the bottom of which the tube
channels open as narrow, transverse, more or less curved fissures,
about one millimeter wide in the longer direction, and one quarter
of a millimeter in the shorter. The body side of these pits is
formed of spreading walls, which help to form the front part of the
orifices next above. The outer half of the pits is formed by the
obliquely truncated ends of the extremely massive tube walls, and
projects under the form of a clumsy lip, giving the stems a very
rough appearance. The outer transverse diameter of the orificial
pits is nearly two millimeters ; the compressed, band-like tube chan-
nels become circular at short distance in from the peripheral ends,
and are about one third of a millimeter in width. Pore channels
distant. Diaphragms have not been noticed.

Plate XXII., Lower tier. — Upper third figure from the right
side represents a silicified fragment of a reticulated expansion, from
the Falls of the Ohio.

CLADOPORA EXPATIATA, N. Sp.

Reticulated expansions of cylindrical or compressed palmate
stems, of a diameter from one to two centimeters, attached by a
massive basal expansion. Tubes of the basal part diverging out-
ward, prostrate, and more compressed than those of the stems,
with a sharp scaly lip at the outer margin. Tube walls generally
very stout. Orifices of the stems variable in the same specimens.
Usually they open with no great obliquity to the surface, and join
under irregular, polygonal crested outlines inclosing deep conical
cell pits, narrowing into cylindrical tube channels. The dilated
margins are not converted on the outer side into a lip, but form a
uniform network, as in a Favosites. Often also, by incrassation of
the tube walls, the cell pits become partly filled, and shallower in
the expanded marginal portion, while the crests of their circumfer-
ence are rounded off. In other specimens the tubes open with great-
er obliquity to the surface, and do not join with crested margins encir-

PAL.-EONTOLOG Y.

57

cling orificial pits, but the body portion of the orificial walls spreads
into a common interstitial surface, and the front walls project as
sharp semicircular lips. Transitions from one of the surface characters
described into the other can be followed out in nearly every larger
specimen. The end branches generally differ somewhat from the
older stems, and the orifices of the upper surface of the prostrate
expansions are not quite alike to those of the under side. The di-
lated orificial pits are nearly always wider in the transverse direc-
tion of the stems than in the vertical ; their diameter is about one
and a half millimeter ; that of the inner tube channels about one
third to one half millimeter. Pores distant. Diaphragms sparingly
developed. From the former species, this one differs in having
smaller tubes, and less compressed, nearly circular orificial open-
ings ; but great similarity exists between them, and by reason of
the great variability in the surface structure of both, it is sometimes
hard to tell to which class certain specimens belong.

Plate XXII., Lower row. — The three left-hand figures are silici-
fied fragments from the Falls of the Ohio, representing a few of the
modifications in which the species occurs.

STRIATOPORA, Hall.

Ramose stems, composed of thick-walled conical tubes, opening
on the surface with oblique dilated orifices, in all particulars cor-
responding with the structure of Cladopora, from which they mainly
differ by a cycle of longitudinal furrows radiating across the ex-
panded tube margins, a difference which, as previously remarked, is
not at all peculiar to Striatopora, but belongs to the essential family
characters of all Favositoids, and happens to be more obviously
developed in the forms called Striatopora than in the next related
Cladopora. In addition to the longitudinal furrows, the inter-
mediate band-like spaces also sometimes bear rows of spinules ;
and as another peculiarity in Striatopora, the abundant develop-
ment of lateral pores may be mentioned.

STRIATOPORA HURONENSIS, N. Sp.

A single fragment of a stem eight millimeters in diameter is the
only specimen I have seen ; but as being one of the first representa-

58 LOWER PENINSULA.

lives of the genus, and positively differing from Striatopora flexuosa,
Hall, found in the same geological horizon, I thought it proper to
describe even a fragment when well characterized.

Orifices obliquely funnel-shaped, joining with edged margins.
The body side of the orificial walls is spreading and forms part of
the exterior walls of the orifices above ; the outer side of the
oblique orificial funnels is margined by an erect semicircular lip.
Diameter of orifices in transverse direction two millimeters ; in
longitudinal three millimeters. Twelve deep longitudinal furrows,
with intermediate obtuse crests, give the cells a star form. The
tubes are distinctly intersected by diaphragms with marginal de-
pressions. Pores are somewhat obscured by the rough silicified sur-
face of the specimen, but are recognizable. Found in the Niagara
group of Point Detour, Lake Huron.

Plate XXIV. — Fig.*!^ upper fragment, natural size. Striatopora
flexuosa, Hall, has not been observed among the fossils of the Ni-
agara group in Michigan.

STRIATOPORA RUGOSA, Hall.
Synon., CvATHOPHORA lowENSiS, Owen.

Stems with dichotomous branches, from five to ten millimeters in
diameter, composed of very thick-walled tubes opening obliquely
to the surface, with dilated mouths, bounded on the exterior side
by a prominent semicircular lip. The inner body side of the walls
of the orifices is flattened, spreading into a common, broad, interstitial
mass. Diameter of orifices two millimeters ; of interior channels one
millimeter. Pores large, distant. Diaphragms not observed. The
radial striai are, in all the numerous specimens which I have exam-
ined, totally obsolete, for which reason this form would have a more
appropriate place under the genus Cladopora.

Occurs frequently in the Hamilton strata of Thunder Bay, and
is found in the drift. L^J^/

Plate XXIV., Fig. -2*-^ — The sunt ml figure represents a stem from
Thunder Bay.

PALAEONTOLOGY. 59

STRIATOPORA CAVERNOSA, N. Si>.

Stunted ramifications of cylindrical or compressed stems, from one
to two centimeters in diameter. Tubes large, in comparison with
the size of the stems, and very unequal through the frequent inter-
calation of young tubes. Orifices oblique to the surface, rounded, or
of irregular shape, joining with obtusely edged stout walls. They
form gradually dilating, spacious, deep funnels, which are longitudi-
nally grooved by a cycle of twelve well-marked striae. A remarkable
abundance of large irregularly dispersed pores perforates the tube
walls within the orificial funnels, and even close to their external
edges. Diaphragms flat, well developed. Diameter of full-grown
tubes at the orificial ends from two to three millimeters ; internal
tube cavities one millimeter wide. Occurs in the drift of Michigan,
associated with corniferous limestone fossils, and is found in place
in the corniferous limestones of Port Colborne, Canada West ; rarely
also at the Falls of the Ohio.

On Plate XXIII., Fig. 3, are small silicified fragments found in
the drift of Ann Arbor.

STRIATOPORA LINN^ANA, Billings.

Dichotomously branching stems, from a few millimeters to one
centimeter in diameter. Orifices moderately oblique to the sur-
face, joining under acute polygonal margins, which inclose funnel-
shaped orifices, and project on their outer margin as prominent lips.
Tubes very unequal in size, through the frequent intercalation of
young tubes. Orificial margins grooved by a cycle of twelve deep
furrows, and the interstitial, band-like spaces are decorated with
longitudinal rows of spinules, which in the narrower neck portion
of the tube channels project as stelliform radii. Pores large and
very abundant, perforating also the expanded parts of the orificial
walls. Diaphragms well developed in some of the specimens.
Diameter of the peripheral tube margins about two millimeters ;
of interior parts one millimeter or less.

Occurs in the Hamilton group of Thunder Bay in silicified condi-
tion, and at Widder, in Canada West, in calcified form.

6o LOWER PENINSULA.

Plate XXIII., Fig. 5.— The three upper specimens were found
at Thunder Bay, near Alpena ; the three lower specimens are
from Widder, Canada West. Fig. 6 of the same plate represents a
larger form, found in the corniferous limestone of the Falls of the
Ohio, which does not seem to differ much from the Hamilton form,
except by a more robust growth, and by less definitely circumscribed
orifices.

DENDROPORA, Michelin.

The corals, one of [which is described by Michelin under the
name of Dendropora, have been placed by Milne-Edwards with the
sub-order Seriatoporinae, through misapprehension of their struc-
ture, attributing to them a central columella which does not exist.
Their structure is in all essential points identical with the Favo-
sitinae. Milne-Edwards divides these forms into three genera :
Dendropora, Rhabdopora, and Trachypora, according to certain
surface characters which I have not considered important enough
to justify the separation. In the following pages, therefore, I use
the name Dendropora for all of them, and give the subjoined defi-
nition of the term Dendropora :

Branching and frequently reticulated stems, variable in diame-
ter from one millimeter to more than one inch. The stems are at-
tached to other bodies by an incrusting basal expansion ; they are
composed of very thick-walled, intimately united conical tubules,
diverging from an imaginary axal centre in ascending curves. The
tube channels are laterally connected by pore channels and trans-
versely septate by diaphragms. The interior tube ends' are only
moderately thick-walled, but in approaching the periphery the walls
thicken very much by the addition of concentric layers within the
expanding channels, and constitute by their intimate union a
broad interstitial surface separating the orifices. In some forms
this interstitial surface is covered by spinulose ridges and granula-
tions ; in others by flexuose longitudinal rugae, or by a combination
of both granules and rugae, with intermediate punctiform or short
fissure-like porosities, which are not cell spaces of an independent
tissue element, but are merely superficial punctations and engrav-
ings of the substance of the tube walls. The orifices usually pro-
ject with their margins above j^the general surface, but sometimes

PA L.EONTOLOG V. 6 1

they appear as impressed pits, or have at least no projecting rim.
Their form is either circular or elongate elliptical. Sometimes
they are disposed in regular longitudinal rows on the stems, but
are also often irregularly dispersed. The obliquity of the tube
mouths to the surface is variable, and in some species they open
almost rectangularly to it. In a part of the species the tube chan-
nels are [^longitudinally striate, as in Striatopora, but usually this
striation is obscure.

DENDROPORA ORNATA, N. Sp.

Circular stems, from one to two centimeters in diameter, with
dichotomous ramification. Orifices circular or oval, rising above
the surface by a monticulose circumvallation, or nearly even with
it, of unequal size and irregularly dispersed over the massive inter-
stitial surface of the stems, which is usually wider than a tube diam-
eter, with exception of the ends of the stems, where the orifices are
separated by comparatively narrow intermediate walls. The inter-
stitial surface is decorated by granules and short ridges disposed in
loose radial order around the circumference of the orifices. Periph-
eral diameter of orifices about one and a half millimeter ; within
they gradually contract to a diameter of not more than half a milli-
meter. The terminal ends of the branches have somewhat larger
orifices with thinner walls, greater obliquity to the surface, and are
surrounded by a more or less projecting lip on the exterior side, as in
the case of specimens of Cladopora or Striatopora, from which these
parts differ only by the granulated edges of the interstitial walls.
In polished vertical sections, through calcified stems, the tubes are
found to be decorated with a cycle of longitudinal rows of spinules,
and the development of distant transverse diaphragms and of large
connecting pores can likewise be ascertained. Found rarely in the
Hamilton group of Thunder Bay, but very common in the Hamil-
ton strata of New York, at Darien, Eighteen-Mile Creek, Seneca
Lake, etc. ; at Widder, in Canada, italso sparingly occurs.

Plate XXIII. — Fig. i represents specimens from Darien, in calci-
fied condition. /^a-i«j.-e*

Plate XXIV., Fig. 2.-7'TMgure to the right is a young silicified
branchlet found at Alpena, Mich. It exhibits a scar of attach-
ment at the lower end. The ends of the branches are formed

62 LOWER PENINSULA.

of thin-walled tubes with nearly contiguous orifices. The granu-
losa decorations of the interstitial surface are obscure in this spec-
imen.

DENDROPORA NEGLECTA, N. Sp.

(Compare Farwsiies polymorp/ia, Billings, Canad. Journ., 1859, p. in, Fig.
12, with exclusion of the other figures.)

Stems from five millimeters to two centimeters in diameter, with
irregularly straddling branches. Orifices very unequal, circular or
oval, narrow, funnel-shaped, oblique, or almost rectangular to the
surface, surrounded by a prominent rim, or nearly even with the
interstitial surface, which is quite spacious and decorated with
ridges and granulations as in the former species. Many of the
stems, however, are nearly smooth on the surface, either through
the wearing off of the decorations or through original want of
their development. Older stems are sometimes found with nearly
solid surface, the orifices having become narrowed to minute
punctiform openings by excessive incrassation of the tube walls.
The central portions of the stems are always formed by thinner-
walled tubes or tube ends, with subangular outlines and of regu-
lar Favosites structure, having connecting pores, transverse dia-
phragms, and being longitudinally striate by faint spinulose ridges.

Found in the drift of Michigan, associated with other fossils of the
corniferous limestone formation. It is found in place at Port Col-
borne, Canada, at Caledonia, N. Y., and at the F'alls of the Ohio.
At the latter place some large stems, over one inch in diameter, are
found, which are usually much altered by silicification ; but most
of these specimens have, on small circumscribed spots of the stems,
the surface characters finely preserved, and exhibit longitudinally
oval, funnel-shaped orifices of equal size, two millimeters in length
and one and a half in transverse direction. The broad interstitial
surface is cither smooth or decorated with obtuse papilli. Lateral
pores and transverse diaphragms distinctly observable. These
may constitute a different species from the former.

Plate XXIII. — Fig. 4 represents silicified stems of the usual form
found in the drift in Michigan, and in the corniferous limestone of
Port Colborne ; the outer stem on the right side is altered by thick-

PALA£ON TO LOG Y. 63

ening of the tube walls, but in other specimens the alteration
reaches a still higher degree.

DENDROPORA ELEGANTULA, Billings.
Synon., Trachypora Elegantula, Billings.

Small ramified stems, from two to five millimeters in diameter.
Orifices longitudinally oval, oblique, effuse above, the remainder
of the circumference being edged by a projecting rim ; they are
arranged in four longitudinal rows on the stems, but often the
regularity of the rows is disturbed by interposition of single orifices
in the intervals between. Interstitial spaces broad, decorated
with flexuose and interlacing rugae, covered by delicate granules,
and rendered minutely porous by a superficial punctiform and fis-
sure-like perforation "of the wall substance. On the surface the
walls of the single tubes are quite undefined, while in the centre of
the stems the walls are much thinner, and are well defined from
one another, exhibiting lateral connecting pores and transverse
diaphragms. The bottom of the conically dilating orifices is gener-
ally formed of a stout obliquely situated diaphragm. Diameter of
orifices in transverse direction one millimeter ; in longitudinal one
and a half millimeter ; internal tube cavity much narrower.

Occurs rarely in the Hamilton group of Thunder Bay, near
Broadwell's mills, where it is associated with several other species
of Dendropora. The specimens represented on Plate XXIII., Fig.
2, are from the Hamilton group of Widder, C. W., the locality from
which Billings described his original specimens.

DENDROPORA ALTERNANS.

Stems of about four millimeters in diameter, with remote oval
orifices in quincuncial position, forming about five loose, alternating,
longitudinal rows in the circumference of a stem. Diameter of orifices
lengthwise from one and a half to two millimeters, and one milli-
meter in transverse direction. Margins raised into an obtuse cir-
cumvallation. Surface minutely punctate by acutely pointed gran-
ules, but not ornamented with longitudinal rugae. Occurs associated

64 LOWER PENINSULA.

with the former species in the Hamilton group of Thunder Bay
River, near Broadwell's mills.

Plate XXIV., Fig. i. — The two larger stems on the upper rock-
piece are representations of this form in natural size.

In the upper right-hand corner of the same piece a small, flat, basal
expansion and a stem of another smaller species of Dendropora are
represented. The tubes of these are arranged in distant, irregularly
quincuncial order ; the interstitial surface exhibits the same orna-
mentations by rugae as Dendropora elegantula, but the species is,
on the whole, smaller, and the arrangement of the tubes is different.

The material at my command is not sufficient to enable me to
give full characteristics of the latter kind, but I think it is specifi-
cally a distinct form.

DENDROPORA PROBOSCIDALIS, N. Sp.

Small reticulated branchlets, not much over one millimeter in
diameter. Orifices forming proboscidal, spoon-like projections,
disposed in five or six longitudinal alternating rows on the circum-
ference of the stems, or of more irregularly dispersed position.
Interstitial surface longitudinally rugose, and dotted by punctiform
and fissure-like porosities. Diameter of orifices about one third of
a millimeter. Occurs with the former at Broadwell's mills ; rarely
also at Partridge Point, Thunder Bay, in the highest beds of the
formation. / ^„

Plate XXIV., Fig. 4. — The wpp»r group of stems, oncopt the
trrn nn *^^" ^""^f ^-'^^ gives a magnified view of the branchlets.
Enlargement two diameters.

DENDROPORA (?) RETICULATA, N. Sr.

With doubt I arranged, under the genus Dcndropora,the coral of
which a description follows : Reticulated horizontal expansions of
small cylindrical stems about two millimeters in diameter, composed
of moderately thick-walled conical tubules, the outlines of which in
their longitudinal extension can be distinctly seen. Orifices erect,
circular, with free margins. Stems similar to Aulopora spicata (;f

PAL.'EONTOLOG V. 6 5

Goldfuss, in external structure, but more minute, the diameter of
the tubes being only one third to one half millimeter. Interstitial
surface smooth, neither rugose nor granulose. Found in the upper
strata of the Hamilton group at Partridge Point, and in the lower
beds on Thunder Bay River, at Broadwell's mills.

Plate XXIV., Fig. i. — The lower piece represents a reticulated
expansion from Partridge Point, Thunder Bay. On the same plate,
Fig. 4, the lewcr row of stems nnnl fl^" two atemj on l^ft .'jiek uJ
^10 uppor rmw aro magnified fragments (two diameters) of the
same kind, found at Broadwell's mills, on Thunder Bay River.

THECIA, Milne-Edwards.

Massive or rarely dendroid polyparia with the general structure of
Favosites. Tube walls very thick, forming, by their junction under
defined polygonal outlines, solid interstitial spaces as wide or even
wider than a tube diameter ; sometimes, however, the walls do not
exceed in thickness those of an ordinary Favosites, and the dilated
tube margins join with edged polygonal margins. Tubes radiated by
twelve spinulose, longitudinal crests almost extending to the centre,
with intermediate, narrow, linear furrows. The internal crests of the
orifices are sometimes prolongated externally, and extend as low
radial rugse across the surface of the interstitial spaces from one
tube into the other ; or the interstices, if large, are irregularly granu.
lose on the surface. Transverse diaphragms well developed, flat or
convex, projecting within the orifices as a central boss and covered
with spinules or granules like the other surface of the tube cavity.
Lateral pores large and abundant. Tubes frequently subject to in-
crassation at the expense of the lumen of the tube cavities, while
the pore channels retain their original diameter and become longer.
The external appearance of such specimens becomes thereby con-
siderably altered, and in silicified specimens, in which the silex is
deposited in the peculiar concentric, annular dots so often noticed,
the structure becomes so much obscured that it would be impos-
sible to recognize their true nature if it were not that other, better
preserved specimens, only partially altered in this way, can be
found amongst them. The genus Protaraea of Mihie-Edwards,

5

66 LOWER PENINSULA,

placed by him with the Zoantharia perforata, is intimately related
to Thecia. It is composed of short conical tubules, communicat-
ing by lateral pores, radiated by twelve granuloso-spinulose
crests, and intersected by convex diaphragms of spinulose
surface. The tubules are incrusting and never attain any great
length.

THECIA MAJOR, N. Sp.
(Compare Favosites Forbesii. Roemer, Silur. Fauna of Tennessee.)

Discoid, lenticular expansions, covered on the lower side by a con-
centrically wrinkled epitheca, with diverging striae, indicating the
outlines of procumbent tubes, which bend into an erect position
before they open on the upper surface of the disks. Diameter of
tubes two millimeters, joining under well-marked, obtusely crested,
polygonal margins, which inclose dilated orificial pits. Walls
stout, but variable in thickness in different portions of the same
specimens. Twelve radial crests extend half way to the centre ;
their edges are decorated with two rows of granulose spinules. Di-
aphragms numerous, partially flat, partially convex, forming a mon-
ticulose projection with spinulose or granulose surface. Pores large
and abundant. Occurs in the Niagara group of Drummond's Island,
Point Detour, and in many other localities on the south shore of
the Upper Peninsula. Found also in abundance at Charleston
Landing, Indiana ; at Louisville, Ky., and in many Niagara out-
crops of the West.

Plate XXV. — Fig. i, specimens in calcified condition seen from
the upper and lower side, both from Charleston Landing, Indiana.
Fig. 2 represents a silicified specimen found at Point of Barques, on
Lake Michigan. The upper end of the specimen exhibits well-
preserved tube orifices with radial crests, convex diaphragms, spinu-
lose surface decorations, etc. ; the lower portion is formed of tube
casts with flat diaphragms, crcnulated at the circumference by the
indentations made by the radial crests of the walls ; the perfect
correspondence of the structure of Thecia with Favosites is most
beautifully to be seen in the represented specimen.

PALAEONTOLOGY, 67

THECIA MINOR, N. Sp.
{Vule Roemer, Silur. Fauna of Tennessee, Tb. 2, Fig. 4.)

Thecia Swinderiana,

General structure perfectly conformable with the former species.
Discoid expansions covered on the lower side by an epitheca, con-
centrically wrinkled, and exhibiting the prostrate tube channels
diverging from the centre. The main difference between the two
forms lies only in the size of their tubes, which in this latter form is
only one millimeter instead of two, as in the former. The speci-
mens vary considerably in their surface characters. Some have
only moderately stout tube walls, and join with gently dilating
mouths under edged polygonal margins. With the increase of the
thickness of the walls the orifices lose their circumscribed form, and
the thickened walls combine into a common, broad,. interstitial sur-
face impressed with small, circular, radiated cell pits. The radial
crests often extend across the interstitial spaces from one orifice
into the other as superficial rugae, mingling with additional irregu-
lar rugae and granulations by which the interstitial surface is deco-
rated. By a still greater degree of incrassation of the tube walls
the orifices become almost closed, punctiform, while the lateral pore
channels remain as large as ever, and prolongate in proportion to
the thickening of the wall substance. Such specimens appear as
massive expansions, perforated by horizontal vermicular channels,
of stelliform arrangement around the narrow, punctiform, central
tube channels in vertical position, and their identity with the other
well-formed specimens would scarcely be supposed, if all possible
gradations from normally formed ones to the disfigured altered;
specimenswerenotplentifully found associated with them. Found •
at Point Detour, Drummond's Island, and in other Niagara out.
crops, in association with the former species ; occurs also in the
drift of the Lower Peninsula, and in the Niagara group of Indiana
and Kentucky.

Plate XXV. — Fig. 3 represents a calcified specimen found at
Louisville, Ky. ; the Michigan specimens are all silicified, with not
nearly so well-preserved surface characters.

68 LOWER PENINSULA.

THECIA RAMOSA, N. Sr.

Stout, branching, and sometimes reticulated, anastomosing stems,
from half an inch to two inches in diameter, composed of thick-
walled, conico-cylindrical tubes ascending and diverging from a
central imaginary axis. Orifices unequal, of polygonal form, from
one to two millimeters wide at the edges of the dilating margins,
radiated by twelve prominent spinulose crests, extending through
the Avhole length of the channels. Transverse diaphragms partly
simple and complete, partly incomplete, represented by lateral
squamiform, horizontal leaflets. Pores large and very numerous.
Older stems are often much altered in appearance by excessive
thickening of their tube walls, and contraction of the tube channels,
with obliteration of the radial crests. It is sometimes difficult to
distinguish them from similarly altered stems of Favosites radici-
formis, with which they are found associated. Occurs in the upper
Helderberg strata of Mackinac Island, and is not uncommon in
drift boulders on the Southern Peninsula of Michigan. It is found
in great perfection and frequency in the Helderberg limestones of
the Falls of the Ohio. The silicified specimens represented on
Plate XXV., Pig. 4, are from the latter mentioned locality.

VERMIPORA, Hall.
(Twenty-sixth Annual Report of the State Cabinet.)

Ramified twigs, composed of contiguous, subparallel cylindrical
tubules, multiplying by lateral gemmation, slowly diverging in their
parallel ascending course from a central imaginary axis, and be-
coming disjunct near their peripheral ends, which project on the
surface as single proboscidal siphuncules. Tubes intersected by
remote transverse diaphragms, and connected by lateral pores.
Vertical radiating crests not observed.

Mr. Hall places these forms with the Bryozoa, and gives of their
structure a description different from mine. He has overlooked

'PALAEONTOLOGY.. 69

the principal Favositoid characters of the tubes, diaphragms, and
lateral pores, but I think these organs can be found in his speci-
mens as well as in those I have under consideration.

VERMIPORA NIAGARENSIS, N. Sp.

Short club-shaped branchlets about one centimeter in thickness.
Tubules half a millimeter wide, slowly diverging from an imagi-
nary central axis in a curve. The outer free end of the tubes is
more abruptly bent, and opens rectangularly to the surface of the
stems. In the interior of the stems the tubes are polygonal by
mutual pressure ; the free ends are perfectly circular, annulated by
delicate wrinkles of growth, and in some a faint longitudinal stria-
tion is observable. Transverse diaphragms flat and distant. Pores
large, irregularly dispersed. Found in the Niagara group of Point
Detour, Lake Huron, and in Iowa, near Masonville.

Plate XXIV., Fig. 3. — Lower figures are specimens from the
Niagara group of Masonville, Iowa, magnified about two diameters.

VERMIPORA FASCICULATA, N. Sp.

Small branching stems, from two to five millimeters in diameter;
tubules one half millimeter wide, ascending in almost parallel fasci-
cules in the stems, until their ends, with an abrupt bend outward,
become free. Diaphragms, intersecting the tubes and connecting
pores, are plainly observable, as well as the intercalation of new
tubes by lateral gemmation.

Found in the Hamilton group of Thunder Bay, and frequently
in boulders of the drift, which, according to the rock character and
associated fossils, belong to the corniferous limestone formation.

Plate XXIV., Fig. 3. — The upper specimens artificially crowded
together. A part of them represents specimens of the corniferous
limestone found in the drift ; the outer specimen on the right-hand
side and the slender central stem are from the Hamilton group of
Alpena. Magnified two diameters.

/O LOWER PENINSULA.

QUENSTEDTIA, N. Gen.

Single cylindrical tubules, multiplying by lateral gemmation of
either single tubes, or many at once, surrounding the mother-tube
in a verticil, and remaining for a while in close contact with it, and
amongst themselves. After some distance the young tubes bend
outward with their ends, which separate and become free diverg-
ing branches, which, in their turn, again become mother-tubes by
renewed gemmation. The tubes are intersected by remote trans-
verse diaphragms. In places of contiguity they connect by lateral
pore channels, and in well-preserved specimens longitudinal rows
of spinulose crests project from the inner side of the tube walls.

QUENSTEDTIA UMBELLIFERA.

Synon,, Aulopora umbellifera, Billings.
AULOPORA CORXUTA, Billings.

Tubules about two millimeters in diameter, delicately annulated
by wrinkles of growth. At variable intervals, single tubes, or from
six to twelve in a verticil, sprout from their sides and remain closely
attached to them and to one another for the length of about five
millimeters, when they bend outward and separate, radially diverg-
ing as free branches, which themselves soon throw out new verticils.
The central tube always grows straight on, at intervals, continuing
to gemmate. Loose stems with a verticil of branches at the end have
remote resemblance to a small Crinoid head on its stem. Within the
circle of branch tubes the central tube is generally dilated by a bulbi-
form inflation. The basal apices of the young tubes do not communi-
cate with the older tube by simply opening into it, but by a narrow
circular pore, narrower than the entire width of the channels. Besides
these connections with the basis, the young tubes connect by lateral
pore channels with the old tube, and laterally also among them-
selves. Diaphragms are quite distant, and not always observable ; the
longitudinal rows of spinules also are only noticed in very favorably
preserved specimens but are sometimes very well developed. By

PAL^ONTOLOG V.

71

examination of larger clusters it can be ascertained that the same
stems which usually send forth verticillate branches often also give
off single or only two or three branches. Mr. Billings considers
these as a different species, and names them Aulopora cornuta, but
frequently both forms are often seen as parts of one and the same
colony of stems.

Found in the drift of Michigan, associated with fossils of the
corniferous limestone. It is common in the corniferous limestone
of Port Colborne, C. W. I also discovered several specimens fully
identical with the form of the corniferous limestone, in the Hamil-
ton group of Thunder Bay.

Plate XXXIII., Fig. 3. — The upper figures grouped together are
specimens from the drift, natural size.

QUENSTEDTIA NIAGARENSIS.

Tubes fully two millimeters in diameter, branching from a mother-
tube in irregular clusters, and diverging after a short space of con-
tiguity with production of new lateral tubes. Lateral pores are large
and surrounded by a projecting rim. Longitudinal crests, or rather
rows of spinules, distinctly seen. Diaphragms are not preserved in
the specimens from Michigan ; others found in Iowa exhibit them.
Found in the Niagara group of Point Detour, Lake Huron, and at
Masonville, Iowa.

Plate XXXIII., Fig. 3, — Lower solitary specimen, found at Point
Detour.

MICHELINIA, De Koninck.

Including Chonostegites, Milne-Edwards.

Compound polyparia formed of elongate, conical tubes, intimate-
ly connected in their whole length, or in rare instances with the con-
tiguity interrupted at intervals by constrictions. The tube channels
are in places of contiguity connected by lateral pores ; their cavity is
intersected by a succession of diaphragms of compound, irregularly
vesiculose structure, and the sides of the tubes are longitudinally
striate by numerous linear furrows, with intermediate rows of spinu-

72 LOWER PENINSULA.

lose prominences. This structure is in general conformity with the
structure of Favosites, from which it differs in the vesiculose nature
of the diaphragms, and in having a much greater number of longi-
tudinal furrows. In Favosites these never exceed the number 12, but
in Michelinia they are more than double that number. The tubes
of Michelinia are usually also of much larger size than in Favosites.
The genus Michelinia appears nearly contemporaneous with Favo-
sites in the upper Silurian strata. A small nummiform species,
which to my knowledge has not yet been described, occurs in the
Niagara group of Tennessee. Another somewhat larger but very
similar form is found in the lower Helderberg strata of Schoharie
County, N. Y., which is described by Mr. Hall under the name of
Michelinia lenticularis. None of these have been found in Michi-
gan. The Devonian formation contains a variety of forms, nearly
all of which are represented in Michigan. Formerly the casts of
small specimens of Michelinia were through misapprehension classed
under the name of Pleurodictyum problematicum, as being a fossil
of peculiar organization. I have exposed this error in an article
published in 1862 in Silliviaii s Joiirnal.

MICHELINIA CONVEXA, D'Orbignv.

Hemispherical masses, with a depressed, turbinate, discoid under
side, covered by a concentrically wrinkled epitheca, formed of di-
verging, large, conical tubes of unequal size and of rounded-poly-
gonal outlines, the larger ones attaining a diameter of one centi-
meter ; walls stout. Transverse diaphragms globoso-convex, com-
posed of larger and smaller irregularly interlacing vesiculose plates.
Vertical furrows in the circumference of a tube about forty, with
intermediate rows of short, spinulose projections. The surface of
the diaphragms is generally smooth ; in rare instances they are cov-
ered with granular prominences. Pore openings small, surrounded
by a projecting rim, irregularly dispersed, and in some parts much
more crowded than in others. Found in the drift, associated with
corniferous limestone fossils in silicificd condition. Very common
in the corniferous limestone of Port Colborne, C. W.

Plate XXVI. — P^ig. i, view from above ; P^ig. 2, view of the lower
side of silicified specimens from Port Colborne.

PA L.EONTOLOG Y. 73

MICHELINIA CYLINDRICA, Milne-Edwards.

Synon., Emmonsia CYLINDRICA, Milne-Edwards.

MiCHELlNIA INTERMITTENS, Billings in parte.

Synon., Favosites Maximus, Troost.

Large, convex masses, formed of slowly diverging, subparallel,
obtusely polygonal, sometimes circular tubes of unequal size, from
five to seven millimeters in diameter. The tubes have either
straight walls, or are at regular, short intervals constricted by ring-
like carinas projecting into the tube cavity. The carinse, caused
by constriction of the walls, correspond with each other in the adja-
cent tubes, but the contiguity of the tubes is usually not inter-
rupted by them. The tubes with straight walls are polygonal in
outlines; those with constrictions are circular ; transitions from one
form into the other are noticeable, sometimes in the same speci-
mens. Inner surface of tubes longitudinally striate and densely
covered with irregularly dispersed, spinulose projections, which also
spread over the surface of the diaphragms. Diaphragms com-
pound, of interlaced, vesiculose plates, not near so convex as in the
former species, and in close approximation. Lateral pores very
irregular, and of different sizes ; in the specimens with constricted
tubes they are confined to the dilated parts, interstitial between
the annular, projecting carinse. Occurs with the other species in
the drift deposits of Michigan ; it is the most common species of
the genus at the Falls of the Ohio, and is found in many localities
of Ohio and Indiana,

Plate XXVI. — Fig. 3 gives a side view of a silicified specimen
from the Falls of the Ohio. Fig. 4 is a surface view of a large, con-
vex mass from the same locality.

MICHELINIA FAVOSITOIDEA, Billings.

Convex masses of diverging, intimately united, polygonal tubes, of
unequal size, from three to five millimeters in diameter. Basal part

74 LOWER PENINSULA.

broadly attached with the centre ; marginal parts free and covered by
an epitheca. Diaphragms nearly flat, often simple, and scarcely
vesiculose, closely approximated ; other times the vesiculose char-
acter is more pronounced. Pores small, irregularly distributed.
Longitudinal stri?e and spinulose rows much more delicate and
minute than in the other species.

Found in the drift of Michigan, and in the corniferous lime-
stone of Canada and New York.

Plate XXVII. — Fig. 4 represents a silicified specimen found in
the drift of Ann Arbor.

MICHELINIA INSIGNIS, N. Sp.

Lenticular convex disks of large size, formed of diverging tubes,
prostrate on the lower side, and composing by their united walls an
epithecal crust with diverging, radial ruga^, and with annular, con-
centric wrinkles of growth. Diameter of tubes from two to three
millimeters. Tubes sometimes moderately stout-walled and join-
ing with acute margins of polygonal outlines ; at other times the
walls are thickened, somewhat dilated at the orifices, with obtuse
rounded interstitial margins. In the same specimens elsewhere,
the orifices of the tubes may be projecting, with raised circular mar-
gins, and the sides of the tubes may be found only in loose lateral
contiguity with teretiform walls, and annulated by fine wrinkles of
growth, with faintly indicated longitudinal striation. The tube
cavity is lined by from thirty to forty longitudinal rows of spinules
or spinulose ridges, which project nearly to the centre of the tubes
as radiations. Diaphragms closely set, concave, simple or com-
pound, of vesiculose plates. Pores numerous, small, irregularly
dispersed. Found silicified in the Hamilton group near Alpena,
also in the Hamilton group of Darien, N. Y., in calcified condition;
likewise in the Helderberg group of the Falls of the Ohio, and in
several other localities of Kentucky, Crab Orchard, etc.

Plate XXVII. — Fig. i is a fragment of a large mass in calcified
condition, found at the P'alls of the Ohio, presenting a vertical sec-
tion. Fig. 2 is a silicified specimen from Alpena, Thunder Bay, seen
from the under side. Fig. 3 is the same, seen from above.

PALEONTOLOGY. 75

MICHELINIA TROCHISCUS, N. Sp.
Synon., AsTR.'EA stylophora, Eaton.

Small hemispherical masses, not often exceeding the diameter of
two inches, usually smaller. The depressed conical or flat basal side
is covered by a concentrically wrinkled epitheca, and is attached by
a broad central scar to other marine bodies, to Gasteropod shells,
Crinoid stems, and very frequently to the surface of Fistulipora.
(See Worth. Geol. of Illin., Vol. III., PL 9, Fig. i/;.) Tubes very un-
equal, rounded-polygonal, from four to seven millimeters wide.
Cavity longitudinally striate by numerous spinulose crests. Dia-
phragms irregular and not much crowded. Pores dispersed without
order.

Occurs in the Hamilton group of Thunder Bay, and is very
common in the Hamilton group of New York. The small specimens
found in the upper Helderberg limestones of Michigan, Ohio, and
Indiana, which are the forms to which Pleurodictyum problema-
ticum has principally to be referred, are almost the same, if not an
identical form, with Michelinia trochiscus. I have not figured this
species.

MICHELINIA CLAPPII.

Synon., Chonostegites Clappii, Milne-Edwards.
Michelinia intermittens, pars, Billings.

Convex or discoid masses, formed of tubular, closely aggregated,
subparallel or diverging polyp stems, from five to eight millimeters
diameter, multiplying by marginal buds. Tubes annulated by
alternate constrictions and dilatations into an urn shape of the in-
termediate segments, having horizontally spreading margins, which
unite with those of the adjoining tubes, forming continuous laminar
floors, whereby the otherwise free tubes are held together and com-
municate with each other by transverse channels crossing the laminae.

76 LOWER PENINSULA.

In some specimens the constrictions are not so deep as in others, and
the tubes then come in more intimate contact with their sides, which
in such case communicate by lateral pores, and fully resemble the
tubes of an ordinary form of Michelinia. The tubes are transversely
intersected by interlacing vesiculose diaphragms of compound
structure ; the channel walls longitudinally striate by furrows and
rows of spinules, conformable with the structure of Michelinia.

Occurs frequently in the drift of Michigan, and is common in the
corniferous limestone of Canada and New York ; it is rarely seen at
the Falls of the Ohio, where Michelinia cylindrica, a closely related
form., is abundant.

Plate XXVIII. — Figs. 3 and 4 represent aside view and a surface
view of silicified specimens.

HALYSITIN.E.

Colonies of tubular polyp cells, multiplying by lateral gemmation,
radiated by a cycle of twelve longitudinal crests or rows of spinules,
and transversely septate by diaphragms of variable form, straight
or funnel-shaped. The tubes are either free, loosely attached to
each other, or laterally connected into laminar rows, or again dis-
tant and connected by short transverse branches, sometimes in-
discriminately anchylosed into irregular conglomerated masses.
The subordinate genera are Halysites, Syringopora, Cannapora, and
Aulopora.

HALYSITES, Fischer.
Catenipora, Lamark.

Elliptical tubes, intimately connected at their lateral edges into
chain-like single rows, which form erect laminar expansions, bent
into tortuous curves, and composing, by the mutual junction and
intersection of the laminae, a network of irregular loops. Tubes
radiated by twelve longitudinal crests, and transversely septate by
closely set flat diaphragms. No lateral connection between the
tubes by pores.

PAL^ONTOLOG V.

77

HALYSITES CATENULATA, Linn.

Synon., Halysites esharoides.
Catenipora labyrinthica, Goldfuss, etc.

A great variety of forms of the chain coral are found which in gen-
eral structure are perfectly alike, but differ widely in the size of the
tubes, in the shape of the orifices, and in the mode of reticulated
connection between the catenate laminae. Some specimens have
elongate, lanceolate orifices, in others the form is oval, and in
others still nearly circular. In those with large elliptical orifices
the longer diameter is often fiv^e millimeters, and the shorter in the
transverse direction three millimeters ; in others the proportions
of the diameters of the orifices are two and a half millimeters by
two millimeters. In the smallest built specimens they measure one
millimeter only in the long direction, and one half in the shorter.
The loops of the laminae are in some forms narrow, in one direction
nearly as wide as in the other ; in other specimens the loops are
large, or the flexuose laminre may for long distances run in close
proximity, parallel with each other, before they make occasional
connection by short transverse branches. The contrast between
these various forms is very great, and it is evident that various
specific forms exist ; but while attempting to define them, I found
so endless a series of transitory connecting forms that I desist from
making a distinction, and use here the collective name of H. cate-
nulata for all. Found in the Niagara group of Michigan, as one of
the most widely distributed characteristic fossils ; likewise common
in the Niagara group of other States east and west. The first speci-
mens of the chain coral are found in the upper beds of the Hudson
River group, in the west portion of the Upper Peninsula of Michi-
gan, but their preservation is so imperfect that it is impossible to
determine whether these oldest specimens represent another species
or not.

Plate XXIX, — Figs, i, 2 and 4 represent three of the many varie-
ties in which the coral is found associated in the strata of Drum-

78 LOWER PENINSULA.

mond's Island and of Point Detour, all in silicified condition-
Fig. 3 of the safne plate I considered sufificiently characteristic to
be described as a distinct species.

HALYSITES COMPACTUS, N. Sp.

Tubes oval, in chain-like, lateral conjunction, but these laminae are
so closely approximated, that no retiform loops are formed by them ;
they come in contiguity with each other from all sides, and leave
only small, angular, lacunose interstices in the corners of their inter-
section, which are not larger than the tube orifices themselves. By
this close approximation of the tubes on all sides many of them
become pressed into a polygonal form and resemble a Favosites,
from which they differ, however, in the absence of lateral pores.
The diaphragms of the tubes are closely approximated, flat, con-
cave or convex in the same specimens. Their diameter is about
one and a half millimeter. Found in the Niagara group along the
outcrops of the Upper Peninsula, at the shore of Lake Michigan.

Plate XXIX. — Fig. 3 represents a lateral section and a surface
view of a specimen found at Epoufette Point. In a stratum of an
outcrop at the mouth of Manistique River this species is quite
common.

SYRINGOPORA, Goldfuss.
Synon., Thecostegites, Milne-Edwards.

Aggregated, sub-parallel, tubular polyp'stems, multiplying by lat-
eral budding, and at irregular intervals connected with each other
by short, transverse, tubular branchlets. The tubes are intersected
by numerous irregularly funnel-shaped diaphragms, and radiated by
twelve longitudinal rows of spinules, which arc sometimes obsolete.
The colonies of erect stems are at the base formed of horizontally
prostrate and attached ends, very much resembling the creeping
expansions of Aulopora, from which the young colonies are often
hard to be distinguished.

PALAEONTOLOGY

79

SYRINGOPORA VERTICILLATA, GOLDFUSS.

Large aggregations of parallel or diverging tubular stems, from
two to three millimeters in diameter, keeping a distance of from two
to five millimeters apart, across which they connect at various not
very close intervals by narrow, transverse, branch tubules, of which
two or three are always sent off at nearly the same height, but
not in true verticillate position. The tubes are filled by invaginated,
irregularly funnel-shaped diaphragms, attenuated at the lower ends
into long siphons. The longitudinal rows of spinules are rarely
well preserved in the tubes of the specimens, which are all found in
silicified condition. The colonies of stems are often large, several
feet in diameter ; their basal portions, composed of prostrate, irregu-
larly reticulated expansions of stems, differ considerably from the
erect parts, and among the specimens of colonies a great many
variations occur as regards the size of the tubes or their mode of
growth. In some the stems are distant, in others near ; in some
perfectly straight, in others flexuose or geniculated, with regular,
verticillate side connections, or with dispersed side arms branching
off at remote intervals or in closer proximity. These associated
forms, sufficiently contrasting in the extreme, I have not attempted
to divide into several species, but consider as variations of Syringo-
pora verticillata, whose enumerated specific characters can not of
course retain the limited form, applying only to a single variety,
which accidentally fell into the hands of Goldfuss, the first de-
scriber of this species. Found abundantly in the Niagara limestone
of Drummond's Island, Point Detour, and in nearly all other fossil-
iferous outcrops of the formation in the western part of the Upper
Peninsula.

Plate XXX. — Fig. i represents a silicified specimen from Drum-
mond's Island, closely similar to the specimen figured by Goldfuss.
Fig. 2 has somewhat smaller tubes, with less regularly disposed,
transverse branch channels and more flexuose stems than the other.
With the above-described specimens others are found, which seem
to agree with Syringopora canccllata of Milne-Edwards. They are
composed of flexuose tubes about one and a half millimeter wide,

8o LOWER PENINSULA.

in loose, irregularly reticulated colonies, with the curved stems alter-
nately contiguous and diverging. Transverse connecting channels
remote, short, and clumsy. Longitudinal rows of spinules and fun-
nel-shaped diaphragms, quite plainly exhibited in some of the
specimens. I have not figured this form for want of space.

SYRINGOPORA ANNULATA, N. Sp.

Small colonies of closely approximated, tubular stems of jointed
aspect, with sharply projecting rings of growth, and with numerous
verticillate, transverse tubules connecting the stems at short inter-
vals. Diameter of tubes about one and a half millimeter. Dia-
phragms of the elongated, funnel-shaped form peculiar to the genus.
Found at Point Detour in the Niagara limestone, and in the drift
deposits of the Lower Peninsula.

Plate XXXIL, Lower tier. — The two left figures represent silici-
fied specimens found in the drift of Ann Arbor.

SYRINGOPORA TENELLA, N. Sr.

Irregularly reticulated colonies of tubules, one millimeter in width,
or less. The tubules branch in the same manner as Aulopora, and
directly connect with each other by approximation, without the in-
tervention of narrower, transverse channels, as in other species of
Syringopora. The tubules exhibit a faint longitudinal striation on
the outside wall, and the cavity is lined by a cycle of twelve spinu-
lose crests. Diaphragms funnel-shaped, but not always developed ;
the channels are often found open throughout.

Eound in the Niagara group of Point Detour, Drummond's Island,
and in the drift. Occurs also in Indiana and Kentucky.

Plate XXX. — Fig. 4 represents a small specimen found in the
drift, seen from the basal side, with creeping, prostrate tubules.
On the upper side of the s])ecimcn the tubules are bent into an
erect position.

PALEONTOLOGY. gl

SYRINGOPORA FIBRATA, N. Sp.

Large convex colonies, with closely approximated subparallel
or diverging tubules half a millimeter in diameter, laterally con-
nected by numerous short transverse channels, branching off at
close intervals from the circumference of the thread-like stems.
The distance separating the stems is variable — sometimes less, some-
times more than one tube diameter. Radial crests long, very distinct,
twelve in number. Diaphragms direct transverse, not funnel-shaped.
This species very frequently grows up in intimate connection with
expansions of Stromatopora. The tissue of the Stromatopora fills
out all the interstices left between the tubules, which in such speci-
mens are usually further apart than in those growing solitary. Both
hold in their growth an equal passus, and the addition of new
layers to the Stromatopora coincides with the growth of the
tubules. It resembles Syringopora compacta, Billings, found in
the strata of Anticosti, but in that species the tubules are in almost
perfe'ct contiguity, and their diaphragms are distinctly funnel-
shaped.

Common in the Niagara group of Point Detour, Drummond's
Island, and frequently found in the drift. It occurs also in the
Niagara group of Indiana, Kentucky, and Iowa.

Plate XXX. — Fig, 3 gives a surface view of a silicified specimen
from Drummond's Island.

SYRINGOPORA PERELEGANS, Billings.

Colonies of tubular stems, from one and a half to two millimeters
in diameter, formed at the base of prostrate tubes, multiplying by
bi- or tri-partite ramification, in the same manner as Aulopora, by
production of one or two young tubes sprouting from the basal por-
tion of their flanks, which creep on for some distance, while the
mother-tube bends its orifice into an erect position, after having
given off the branches. The spreading, prostrate, basal tubes, flat-
tened on the lower side, come in multiple contact with their sides
6

S2 LOWER PENINSULA.

and grow together [into an open, reticulated expansion, or are so
densely crowded as to form an uninterrupted basal leaf, from
which the tubes singly ascend into a vertical, subparallel position,
and then grow up with remarkably straight stems, if not disturbed
by accidental impediments.

The stems in the erect growing parts of the colonies are remote
from each other about the width of a tube diameter, or more, and
are connected by slender, transverse tubules at intervals of from one
half to one centimeter. The tubes are annulated by delicate
wrinkles of growth, with periodical, sharper offsets, causing an ar-
ticulated appearance. Internal structure longitudinally striate by
spinulose crests, and intersected by funnel-shaped, irregular dia-
phragms prolongated with the lower apex into long siphons.

Occurs in the upper Helderberg limestones of Mackinac ; fre-
quently also in the drift, associated with corniferous limestone fossils,
and in the corniferous limestones of Canada, New York, and of
the Falls of the Ohio.

Plate XXXI., Fig. 2. — The small specimen attached to the lower
left-hand corner of the other specimen represents a fragment of a
laminar, basal expansion with erect, circular orifices found in the
drift. Figs. 3 and 4 are silicified specimens from the Falls of the
Ohio — the one with larger sub-flexuose tubes, the other with more
slender and straighter tubes.

SYRINGOPORA MACLUREI, Billings.

Tubes about three millimeters wide, flexuose, occasionally touch-
ing each other, and then diverging again, or at other times of more
regular, subparallel growth, with interstitial intervals usually larger
than a tube diameter, and with remote, slender, transverse tubules of
connection. This coral resembles the former species, differing from
it only in having a larger tube size, and a more irregular mode of
growth, but in many instances it becomes difficult to decide
whether a specimen belongs to one or the other form.

Plate XXXI. — Fig. i represents a fragment found in the drift of
Ann Arbor, exhibiting the terminal portion of a colony. In Fig.
2 the large specimen is another drift specimen, seen from the basal

PAL^ONTOLOG V. S^

side, with the prostrate, creeping, reticulated tube portions. The
basal expansions of the former species, represented in the same
figure, do not always grow in uninterrupted leaves, as in the frag-
ment represented, but often in an open network like that in the
larger figure. In some specimens the tubules are more nearly ap-
proximated than they are seen to be in Fig. i.

SYRINGOPORA TABULATA, Milne-Edwards.

Synon., Thecostegites BOUCHARDI, Milne-Edwards.

Large, convex colonies of diverging, subparallel, straight tubules,
forming incrustations of other marine bodies, with their creeping,
Aulopora-like, basal ends, which subsequently continue to grow
in an erect position. Tubules about one millimeter wide, closely
approximated, with intervals narrower than a tube diameter ; the
transverse connecting tubules branch off in subregular, verticillate
position, and correspond in all tubes in certain levels, by the
lateral anchylosis of which almost uninterrupted laminar floors
are formed ; this is, however, not an invariable structure. The
same specimens often exhibit portions in which the trans-
verse branchlets are not verticillate, but in irregularly dispersed
position, and in which no laminar floors intersecting the colonies
are perceptible. The tubules are distinctly radiated by twelve
spinulose crests, and on the surface of the tubules a dull, longitu-
dinal striation is usually noticed. Diaphragms funnel-shaped, with
tubular invaginated ends. The floors of connecting processes are in
some specimens moderately distant, as in the specimen represented
on Plate XXXIL, upper specimen to the right. These are the
typical form of Milne-Edwards' Syr. tabulata. In other specimens,
particularly those of smaller size, forming incrustations of shells,
etc., these floors are in close approximation, and form a series of
superimposed laminse, separated by small vesiculose interstices.
Milne-Edwards, misapprehending their structure, described them as
the type form of a new genus, Thecostegites ; but a little more
careful examination would necessarily have shown him the specific
identity of tiis Syringopora tabulata with his Thecostegites Bou-
chardi, both described as occurring at the Falls of the Ohio, from

84 LOWER PENINSULA.

which locality the specimens represented on Plate XXXII. come.
The upper convex specimen on the left side of the plate is the
form corresponding with Milne-Edwards' Thecostegites. He has
described similar other forms under the names of Syringopora
Vernaiilli, Syr. Clcviana, and Mr. Billings describes a form under
the name of Syringopora Hisingcri, all of which arc distinguished
from one another by trifling modifications in their manner of
o-rowth. I consider them as mere varieties of one and the same
species for which I retain Billings' name.

SYRINGOPORA HISINGERI.

It differs from Syringopora tabulata by its more distant, some-
what flexuose tubules, with side connections in dispersed position,
and not in verticils. The tubules vary in size from half a milli-
meter to one millimeter. The three lower specimens in the upper
row of Plate XXXII. represent various fragments of this form,
found in the drift. Other specimens are found in which the tubules
are still further apart. The last-mentioned forms are all found asso-
ciated in the corniferous limestone of Michigan, Canada, Ohio, New
York, Indiana, Kentucky, etc.

SYRINGOPORA NOBILIS, Billings.

Colonies of large tubes, from five to eight millimeters in diameter.
In some the tubes are quite remote from each other, and connected
by distant, transverse branch channels ; others have the tubes
more closely clustered and of smaller size. I am not positive of the
specific identity of these forms, but provisionally arranged them
under Billings' name, intended for the form with large, remote stems.
Found in the corniferous limestone, and in the Hamilton group of
Michigan and Canada ; similar forms occur in the Hamilton group
of Iowa.

On Plate XXXII., lower row, right-side figure, is represented a
specimen found in the drift of Ann Arbor, associated with cornifer-
ous limestone fossils ; the adjoining central specimen is a young

PALEONTOLOGY. 85

specimen with closely clustered tubes, found in the Hamilton group
of Alpena.

CANNAPORA, Hall.

{Compare Fletcheria, Mihie-Edivards.)

Colonies of closely approximated, erect tubules with stout walls,
sprouting from an incrusting basal expansion formed of prostrate
tubules growing and multiplying in the same manner as an Au-
lopora. The erect ends of the tubules are annulated by wrinkles
of growth and by sharp-edged, periodical offsets marking an inter-
ruption and renewed growth from the inner circumference of the
old orifices. The sides of the tubes are partly connected by hori-
zontal expansions of the walls, partly in direct contiguity, in which
latter case the otherwise circular tubes are pressed into a polygonal
shape, and connect in the contiguous parts by lateral pores. The
orifices are slightly dilated at the margins, radiated by twelve
spinulose projections, rows of which extend through the whole
length of the tubes. Diaphragms are not often developed, direct
transverse, and not funnel-shaped as in Syringopora. Consider-
able affinity exists between Cannapora and Aulopora.

CANNAPORA JUNCIFORMIS, Hall.

Tubules from one to one and a half millimeters in diameter,
forming large colonies of convex growth, with regular, subparallel
stems in the larger masses ; but in smaller specimens, representing
incrusting basal portions, the tubes are sometimes agglomerated in
irregular manner. Structure in conformity with the above given
general generic description. Found in the Niagara group of Drum-
mond's Island, and sometimes in the drift. In New York State it
is found in somewhat lower position in calcareous layers of the
Clinton group. The tubes of the New York specimens are some-
what smaller than those of the specimens from Drummond's Island.

Plate XXXIII., F'ig. 4. — Lower specimen on left-hand side is
a silicified young colony from Drummond's Island ; the lower figure
on the right-hand side is a fragment of a specimen from the Clinton
group of Brockport, N. Y.

86 LOWER PENINSULA.

AULOPORA, GOLDFUSS.

Colonies of prostrate, stout-walled tubes, attached with their
lower flattened side, multiplying by latero-basal gemmation. One
or two young tubes sprout from the lateral edges of the base of the
creeping tubes near the orifices, which then rise from the prostrate
into an erect position, while the new branches creep on, until they
again send off branches in the same manner, which latter, by coming
in contact in their spreading growth, adhere together and form retic-
ulated loops, or, if closely crowded, continuous laminar expansions.
Other species grow, by union of their tubes, into compact, thicker
masses. It; is rarely the case that they compose ramified branches.
The tubes nearly always exhibit a faint, longitudinal striation and
longitudinal rows of spinules encircling the inner cavity in more or
less rudimentary development. Remote, isolated diaphragms are
sometimes observed, but usually the tube cavities are open through-
out their entire length. Lateral pores connecting the contiguous
tubes channels do not seem to exist. The orifices project with
free circular margins ; occasionally, through being closely crowded,
the orifices of a limited spot may become polygonal from mutual
pressure. Certain minute Bryozoa, in manner of growth resembling
an Aulopora, have been confounded with this genus ; one of them
is Aulopora araclinoidca, Hall ; these have no affinity with Aulo-
pora, their structure being the same as in the Jurassic and cretaceous
genera Proboscina, Berenicea, or Stromatopora, whose utriculous
walls are perforated by numerous microscopical pores, comparable
to the minute punctations of the shell of a Terebratula. These
punctations can be distinctly seen in well-preserved specimens of
Aulopora arachnoidea, collected at Richmond, Indiana.

AULOPORA SERPENS (?) Goldfuss.

Prostrate expansions of conical tubules, one sprouting in a linear
row from the basal part of the orificial end of the other ; or at
ti mcs two of them fork off, and meeting others in the course of their

PALyEON TO LOG V. 8 7

growth, unite laterally with them and inclose irregular loop^-.
All the tube ends, after the departure of a branch tube, bend into
an erect position and usually grow no further. The width of the
tubes of different specimens varies from one to two millimeters.
The identification of this species with the European form, described
by Goldfuss, is made with some hesitation, and is intended rather to
express their great resemblance than a full identity. Found in the
Hamilton group of Thunder Bay and Little Traverse Bay, incrust-
ing other corals.

Plate XXXIII. — Fig. 2 represents a specimen from Little Trav-
erse Bay incrusting a Stromatopora.

AULOPORA CONFERTA, Winchell.

Incrusting, reticulated, or continuous laminar expansions formed
of laterally anchylosed conical tubules, arranged in fan-like, spread-
ing order by emanation from the prolific gemmation of a single
mother-tube according to the bilateral, forking mode of growth ex-
hibited in the generic description. The club-shaped tubules are
about one millimeter wide across the thickest part ; the channels
of the erect, circular orifices measure about half of a millimeter.
Found abundantly as incrustation of other corals in the blue fos-
siliferous shales of Little Traverse Bay.

Plate XXXIII. — Fig. i represents a solid incrustation of the sur-
face of a Stromatopora by this species of Aulopora.

AULOPORA ERECTA, N. Sp.

Massive, incrusting expansions formed of very stout-walled tubes,
about two or two and a half millimeters in diameter. On the basal
side of the expansions, broke loose from the incrusted body, the
prostrate, flattened tubes are noticeable,- grown into a dense agglo-
meration by repeated rapid gemmation. From this basal sheet the
tubules bend into a vertical position, and continue to grow in this
direction for some length parallel with each other, and producing
no more side branches at the rapid rate of the prostrate portions-

88 LOWER PENINSULA.

These erect tubes are circular, closelyjapproximated, or sometimes
in intimate, mutual contiguity, pressing each other into a sub-
polygonal shape. The orifices exhibit a cycle of longitudinal fur-
rows and intermediate rows of spinulose projections in rudimentary
development. Diaphragms are generally not developed. Occurs
in the Hamilton group at Stony Point, Thunder Bay.
Plate XXXIII. — Fig. ^upper specimen.

COLUMNAR!^.

Consisting of the single genus Columnaria.
COLUMNARIA, Goldfuss.

Goldfuss at first included within this genus several corals which
have a different structure ; he acknowledges, in the appendix to
his work, however, that the coral called by him Columnaria sulcata
is only a weathered specimen of Cyathophyllum quadrigeminum.
Columnaria Isevis is also, in all probability, generically different from
his Columnaria alveolaris, which alone is at present considered the
typical representative of the genus. In Goldfuss's characteristics is
expressly stated the absence of transverse diaphragms in the tubes,
although in his figures]the diaphragms of the tubes are so distinctly
delineated that I can not conceive how they escaped his observa-
tion. I define 'the genus as follows :

Convex colonies of contiguous, polygonal, or rarely of free circu-
lar tubes, growing from a few attached mother-tubes by rapidly
multiplying lateral gemmation. Tubes radiated by vertical lamella;
of alternately larger and smaller size, the larger ones in some
soecies reaching- to the centre, or not. Number of lamellae from
twenty to forty.

Transverse diaphragms simple, flat, moderately close in position.
Walls not perforated by pores, thin, and inseparably united in the
forms with polygonal tubes, appearing to be formed of simple lam-
inae dividing the adjoining cavities, but in favorably preserved speci-
mens the duplicity of the walls is positively observed.

FALCON TOLOG Y.

COLUMNARIA ALVEOLATA, Goldfuss.

89

Convex, large colonies, sometimes attaining a diameter of several
feet, composed of intimately connected tubes diverging from a
basal centre. Lower side covered by a concentrically wrinkled
epitheca ; central part attached. Tubes quite unequal in the same
specimens and in different specimens. In some they vary from
two to five millimeters ; in others, tubes one centimeter in width, and
smaller ones of only two and three millimeters, are intermingled.
Radial lamellae from twenty to forty, according to the size of the
tubes, not reaching to the centre. Transverse diaphragms flat, close-
ly set, usually smooth in the centre, and only at the outer circumfer-
ence intersected by the radial crests. It is rarely the case that the
lamellae extend as low carinations over the surface of the diaphragms
to the centre. The figures of Goldfuss exhibit the radii as alter-
nately reaching the centre ; this is, as already stated, very unusual
with specimens from the Trenton group, while it is regularly seen
in the specimens from the Hudson River group and Niagara group.
Milne-Edwards considers both forms as one species, but I think
they differ sufficiently to be set down as two species. To the
Trenton form Goldfuss's name, Alveolata, is applied by most of the
palaeontologists ; for the Hudson River group species, Hall's name,
Columnaria (Favistella) stellata, is adopted, although it is not per-
fectly certain whether Goldfuss had not also a Hudson River
group specimen under consideration.

The Trenton strata of the Escanaba River and of St. Joseph
Island, in Lake Huron, contain an abundance of this coral, but the
specimens are not very well preserved, being transformed into
dolomite spar, which is a very unfavorable material for the pres-
ervation of the finer structural details. This cora) is also fre-
quently found in the Trenton group of Illinois, at Dixon, and in
the lead-bearing strata of Wisconsin and Iowa, where it is often
found in silicified condition, and finely preserved.

Plate XXXIV. — Fig. i is the surface view of a specimen from
the Trenton group of St. Joseph Island. Fig. 2 is a fractured
surface exhibiting a vertical section of a specimen from Escanaba
River. Fig. 4 is a specimen with very large and unequal tubes,
found in the Trentoa group, at Dixon, Illinois.

go [LOWER PENINSULA.

COLUMNARIA STELLATA, Hall.
Synon., Favistella stellata, Hall.

Convex masses of similar structure with the former species ; the
tubes are somewhat less unequal in the same specimens, varying
in size between three and six millimeters. Radial lamellae from
twenty to thirty, alternately larger and smaller, the larger ones
extending to the centre. Diaphragms flat, closely set, intersected
by the radial lamellae, which only in the peripheral circumference
form continuous vertical leaves. The crests continued to the centre
of the diaphragms are merely superficial. Found abundantly on
the north side of Drummond's Island, in the shales of the Hudson
River group. The equivalent exposures in Bay de Noquets, oppo-
site Escanaba, do not contain any. It is likewise found in the up-
per part of the Hudson River, or Cincinnati group, near Madison,
Indiana, and in other localities along the Ohio River.

During the 'progress of the surv^ey, I found specimens which I
consider as identical with this species in the Niagara group of
Point Detour, in which formation it was not' known to occur.

Plate XXXIV. — Fig. 3 gives a surface view of a specimen from
Drummond's Island (Hudson River group).

Plate XXVIII. — Fig. i is a silicified specimen from the Niagara
group of Point Detour.

COLUMNARIA HERZERI, N. Sp.

Colonies of tubes, partially in close contiguity, of polygonal form,
and intimately united with their walls ; partially free, circular,
laterally joining into chain-like rows, not unlike Halysites, or open-
ing singly on the surface. Diameter of tubes three millimeters.
Structure otherwise entirely corresponding with the associated
form, Columnaria stellata.

The specimens were found by Mr. Herzer, of Louisville, in the
Cincinnati group of Kentucky. It may only be a modification in
the growth of the usual form C. stellata. Not figured. The
specimens are too imperfect for photographic delineation.

PALEONTOLOGY. 9 1

ZOANTHARIA RUGOSA, Milne-Edwards.

So called in allusion to the radial rugae or plications of the stony,
calcareous polyp cells, which are the only part of these animals that
has been preserved. The Zoantharia apora of a similar structure
are distinguished from these by a difference in the arrangement of
the radial plications. Milne-Edwards assumes four primary plica-
tions in the cycle of radii in the Zoantharia rugosa, and six primary
plications in the Zoantharia apora, and deduces therefrom, in an
elaborate essay, a law of symmetry, according to which the mul-
tiplication of the radii in the cycles takes place, and by which he
endeavors to demonstrate that in case a new plication or lamella is
formed in the interstice between two older plications of a certain
value in the cyclical order, in all interstices, limited by plications
of the same value, the intercalation of a new lamella takes place
simultaneously, and this law he supposed to be governing the
growth of Zoantharia rugosa, as well as of the Zoantharia apora.
In the latter order this rule seems to be in force, but it does not
apply to the growth of the Zoantharia rugosa.

The radial plications of the Zoantharia rugosa are arranged in
four primary fascicles, separated from each other by more or less
conspicuous gaps. These fascicles, apparently segments of a cycle
of rays, are in reality bilaterally situated in symmetrical position
on an axal line, dividing the apparent cycle in two halves. The
two fascicles on one side are equivalent to those of the opposite
side, but differ from one another. For better illustration, we may
compare the circumference of a polyp cell to a horseshoe with nar-
row, almost closed aperture. Opposite this aperture, in the centre
of the curve, two fascicles meet with their equivalent sides, leaving
an obscure, narrow gap between them, the centre of which often
exhibits a solitary, independent plication. This gap may, in distinc-
tion from the other gaps, be designated by the name of central gap.
At the ends of these fascicles, remote from the central gap, and
directed toward the aperture of the horseshoe, the plications be-
come gradually shorter, and, seen from the peripheral surface of the
polyp cells, do not extend to the apex of the conical polyparium,
but terminate above, nearer the calycinal margins. Another gap

92

LOWER PENINSULA.

separates these shorter plications on each side from the joining
fascicles of plications, which extend to the ends of the arms of the
horseshoe. This pair of gaps are the lateral gaps. The further ends
of this second pair of fascicles approach each other again, in the
aperture of the horseshoe, leaving another larger gap between
themselves than the other fascicles, which may be termed apcrtural
gap ; its centre is, like the opposite obscure gap, occupied by a
solitary plication. The plications of this second pair of fascicles
are longest and extend to the apex of the polyparium on their end
joining the lateral gaps, and shortest at the apertural gap. This
is the order in the structure of all the polyp cells of the Zoantharia
rugosa. If, during the progress of growth, new'plications are added
to the cycle of existing ones, the new ones are only inserted at
those ends of the four fascicles which are directed toward the
apertural gap, while the already existing plications are never dis-
turbed by interposition of new ones, excepting, as indicated at the
four ends of the fascicles, directed to the apertural gap ; further-
more, the addition of new plications at the four ends of the fascicles
^snot always contemporaneous in all, or in the opposite correspond-
ing ones, for otherwise the lamellae in each equivalent bundle should
be equal in number, which is not always the case. This bilateral
structure of the polyp cells of the Zoantharia rugosa has been
observed by several palaeontologists, and been mentioned by them
as a peculiarity of certain species ; but the late Dr. Kunth, of Berlin,
was the first to demonstrate this bilaterality to be an essential char-
acter of all the Zoantharia rugosa, and to exhibit with clearness the
peculiar mode of multiplication of the lamellae in this order. If we
examine a Streptelasma or a Zaphrentis, we find the outer surface
of the polyp cells longitudinally striate, by broad, convex bands or
ribs, and by intermediate, narrow, linear furrows. The furrows cor-
respond to the crest-like plications on the inside of the calyces, the
ribs to the interstitial spaces between them. Three of such longi-
tudinal furrows are, on each of the polyp cells, more conspicuous
than the others ; they correspond to the gaps between the bundles
of lamellae. In the furrow corresponding to the apertural gap, the
other furrows from both sides converge at acute angles, like the
barbs of a plume, to its keel, gradually becoming shorter as they
approach the margins of the calyx. The two other obvious fur-
rows, corresponding with the lateral gaps, arc, on the side nearest

PALJ£ONTOLOG V.

93

to the apertural gap, joined by similar parallel furrows extending
into the apex ; on the other side the furrows abut against it at an
acute angle, and decrease in length as they ascend. The central
gap is not indicated on the outside, because the furrows on both
its sides are parallel with it, as new plications are never intercalated
in this place.

The annexed sketches will cause the descriptions to be under-
stood at a glance. We perceive, by looking at the figures, that

APERTURAL GAP.

CENTRAL GAP.

LATERAL GAP.

in the apertural gap the striae must have a pinnate position,
because on both of its sides new plications are constantly added
to the ends of the fascicles ; for the same reason we see them on
the lateral gap on one side pinnate and on the other parallel,
because no new plications are ever inserted there, and in the cen-
tral they are all parallel because no implantation occurs on any of
its sides.

All Zoantharia rugosa have this structure, but the four principal
septal divisions do not present themselves in all with equal con-
spicuousness. In some the cycle of plications in the calyces is
almost uninterrupted, and they appear as if of truly radial structure j
in others the division lines between the fascicles are well marked
by gaps, which on the bottom of the end-cells dilate into depres-
sions called septal fovcce. The apertural fovea is always the largest,
and an indication of it is noticeable in all forms of this order, while
the two lateral gaps rarely become so distinct as to dilate into
septal foveae. The central'gap is almost in every instance obscure,
scarcely noticeable. Mr. Kunth, in speaking of the position and the

94 LOWER PENINSULA.

development of these foveae, justly remarks that if only one of the
four foveae is well developed, it is always the apertural fovea which
he QaWs principal fovea ; but he is in error when he adds, " only in rare
instances the opposite fovea is best developed." This case never
happens ; in symmetrically curved, horn-shaped polyp cells the aper-
tural fovea is either in the median line of the convexity of the
curve or on the concave side. Not unfrequently the largest fovea
is found in a lateral position with respect to the curvature of the
polyp cells. But even if we find the largest fovea in such lateral
position, it does not follow that one of the lateral fovese has been
developed in preference to the others ; on close examination, it
will always be found that the septal striae on the surface converge
from both sides toward the median line of that fovea, which un-
mistakably proves it to be the apertural fovea ; if it were the late-
ral fovea the striae would converge toward it only from one side,
or if the central, they would be all parallel, which is never observed.

Milne-Edwards divides the Zoantharia rugosa into four families:
the Stauridae, Cyathaxonidae, Cyathophyllidae, and Cystiphyllidae.
These sub-divisions, however, are artificial, not being based on
important differences in the plan of structure,

StaiiridcB are described as polyp cells with well-developed, radial
lamellae, which intersect the whole length of the corallum as unin-
terrupted, vertical leaves, which are at intervals connected by short,
interstitial, transverse leaflets. The lamellae are grouped in four
fascicles, which have their limits'marked by very obvious septal gaps
visible within the'cells under the form of a four-armed cross. The
enumerated genera of Stauridae are : Stauria, a Silurian coral ;
Metriophyllum, a Devonian form ; Polyccelia, of Permian age.
No coral which could be identified as belonging to one of these
genera has been found in Michigan.

Cyathaxonidce are described as single polyp cells, with well-de-
veloped radial lamellae, extending as uninterrupted leaves through
the whole length of the corallum, and uniting in the centre into a
cristiform columella. The interstices between the lamellae are
said to be open throughout without diaphragms or transverse, inter-
stitial leaflets. This family characteristic is based on imperfect
observation. The lamellae do not unite in the centre into a cristi-
form columella, and their interstices are not open all their length,
but have transverse leaves intersecting them, the conically protrud-

PAL^ONTOLOG Y.

95

ing centres of which leaves, one invaginated into the other, form
the cristiform cokimella, and not the united central ends of the
vertical lamella?, which do not perfectly reach the centre under the
form of uninterrupted vertical leaves ; their inner termination is
only a superficial carination on the conical centres of the dia-
phragms. This structure does not materially differ from the
structure of many genera of the Cyathophylloids, particularly of
some forms of Zaphrentis and Trochophyllum. The latter genus
may be said to differ from Cyathaxonia only in the inverted direc-
tion of their invaginated diaphragms. In Trochophyllum the dia-
phragms form deep, funnel-shaped depressions in the centre of the
cells, which, in their invaginated condition, likewise compose a solid
central axis, tuined inward instead of projecting. Cyathaxonia
is not found in the strata of Michigan. The specimens described
from the upper coal measures as Lophophyllum proliferum, Mc-
Chesney, is a genuine form of Cyathaxonia, entirely corresponding
in structure with the forms of Cyathaxonia, described by Milne-
Edwards, from the sub-carboniferous strata of Kentucky. Palaeon-
tologists examining these well-preserved specimens observed at
once the existence of transverse leaves across the radiated inter-
stices of the calyces, and hesitated on that account to identify
them with Cyathaxonia ; had Milne-Edwards examined his type
specimens somewhat more carefully, he would have noticed in
them the same transversal leaves.

CYATHOPHYLLID^.

Simple or compound polyparia formed of cell cups margined by
a cycle of plications of an apparently "radial position toward the
centre of the cells, but actually disposed according to the bilateral
plan peculiar to the whole order of the Zoantharia rugosa.

The polyparia are built up by a successive series of such cups,
one invaginated into the other, with'gradually increased size. In
some forms the cups are clearly defined in their superposition
by a more or less distinct lamination in the structure of the poly-
paria ; in others the union of the cups is more intimate. The pli-
cations of the incased cups corresponding, and clasped over one
another, grow together and form continuous vertical lamina;, while

ge LOWER PENINSULA.

the side walls of the cups unite into a common external wall of
more massive structure ; only the bottoms of the cups escape the
general agglutination of the parts and remain free laminae separated
by an interstice from the adjacent cup bottoms. These laminar cup
bottoms are, in the description of Cyathophylloid corals, considered
under the name of diaphragms. In a portion of the Cyathophylloid
family the interstices between the crest-like plications of the end
cups are free and op?fi ; in other generic groups the interstices are
up to the margins of the calyces traversed and filled with vesic-
ulose plates, which divide them into small cell spaces.

The family of Cyathophylloids is represented by numerous
modifications of its type, which will be specially considered [in
the generic descriptions. Milne-Edwards has adopted thirty-five
genera of Cyathophylloids, and a large number of additional gen-
eric names, partly synonymous with the above, are used in the works
of palaeontologists. A careful study of the various forms has con-
vinced me that a large proportion of the promulgated genera have
been negligently established upon an examination of insuf^cient
material and with incorrect appreciation of structural characters,
individual peculiarities being often mistaken for important generic
differences. In passing the genera in review, I will have frequent
occasion for rectifications and changes in the arrangement by which
the number of the genera will be greatly reduced.

CystipJiyllidcE are pointed out as the fourth family of the Zoan-
tharia rugosa, composed of the single genus Cystiphyllum. These
corals differ from the true Cyathophyllum merely in having but a
rudimentary development of the plications, which never compose
continuous vertical leaves. The plications of Cystiphyllum are
low crests much obscured by the blistered surface of the calycinal
walls, which are entirely composed of vesiculose plates. In vertical
sections the polyparia appear to be built up by a superiniposed
succession of layers of vesicles, disposed in accordance with the
shape of the end cups.

An uninterrupted chain of transition forms between Cystiphyllum
and the corals of the Cyathophylloid family exists, and the rela-
tions of Cyathophyllum proper and Cystiphyllum are so close that
I think it unnatural to separate this genus from it as representing
a different family type.

The formations of Michigan inclose a great many corals of the

PALEONTOLOGY. 97

Cyathophylloid family. The frequent fragmentary condition of
the specimens and the altering effects of petrification prevent, in
many instances, an exact identification of all the collected speci-
mens, for which reason I have restricted myself to the description
of those forms only of which I had satisfactory material for exami-
nation.

The genus Cyathophyllum, which gave the name to the entire
large family, is not the primitive type fornTj which its first rep-
resentatives appeared ; the oldest forms of the Cyathophyllides
Avere of the less complicated structure of Streptelasma and of .
Zaphrentis, which existed already in the lowest strata of the
Trenton period. Cyathophyllum and many other diversifications
of the type commence to appear in the upper Silurian beds. The
Devonian period was the time of their greatest development, and
after the carboniferous period we find the whole family extermi-
nated, leaving no representative in the periods subsequent to the
Permian strata.

CYATHOPHYLLUM, Goldfuss.

Simple or compound polyparia, each polyp cell surrounded by its
own perfect wall. Vertical lamellae well developed, forming con-
tinuous leaves through the whole length of the corallum, and ex-
tending to the centre, or near to it. The interstices between the
lamella; in the peripheral area (formed by the ascending walls of
the calyces) are divided into small vesiculose cell spaces by short,
transverse leaflets extending from one lamella to the other, and
filling the calycinal interstices up to the outer margins. The cen-
tral area (formed by the bottoms of the cell cups) is transversely sep-
tate by continuous simple diaphragms, or by compound plates
formed of several convex, anchylosed pieces ; these diaphragms
are also intersected by the radial lamellae reaching to the centre,
or gradually vanishing in the middle. Surface of vertical lamellae
either smooth or granulose, with entire or with denticulated edges.
Many species of Cyathophyllum have the side faces of their
lamellae decorated by low, equidistant carinae, ascending in a curve
from below and outward to the upper and inner edges, where they
terminate as acute denticulations, or have the form of transverse
trabeculae, the carinae of both sides of the leaves being coincident.
7

q8 lower peninsula.

This carination is very obvious in a certain species first described
in the geological reports of New York under the name of Strom-
bodes helianthoides, which subsequently has been selected as the
type form of the genus HcliopJiylluin (Heliophyllum Hallii), whose
only distinguishing character from Cyathophyllum rests in the
carinated surface of its lamellae. If this distinction had been
carried out strictly, and had all the forms agreeing in structure
with Cyathophyllum, and at the same time having the surface of
the lamellae decorated by carinae, been placed under the genus
Heliophyllum, little objection could be urged against the arrange-
ment, but no attempt has been made to do so. Milne-Edwards,
the founder of the genus, while he describes one form as Helio-
phyllum Hallii, comes out with another equally characteristic Helio-
phyllum under the designation Zaphrentis cornicula, simply be-
cause that species has a somewhat large septal fovea, its only
structural similarity to Zaphrentis. Other forms with the Helio-
phyllum character well developed he continues to consider as Cya-
thophylla, as, for instance, Cyathophyllum helianthoides, Cyath.
hexagonum, Cyath. rugosum, etc.

Carinated lamellae are also regularly observed in the genera Diphy-
phyllum, Acervularia, Phillipsastraea, and in others. Another con-
sideration depreciating the value of the carinations of the lamellae
as a generic mark is their frequent total obsolescence in specimens
which by all other characters belong to a certain carinated species.
Having the alternative before me then, either to adopt Heliophyllum
and to substitute that name for a great man}' others well established,
or to restore a few species now named so to their nearest relatives,
the Cyathophylla, many of which participate in the same character
of carination, I felt inclined to take the latter course as the simplest
and most satisfactory.

CYATHOPHYLLUM HALLH, Milne-Edwards.

Synon., HELiorHVLLUM Hallii, Milne-Edwards.

Simple turbinate polyp cells, attached by the small basal apex, and
frequently by additional root-like prolongations from a part of the
side-walls. The conical shape of the cells varies considerably in

PALEONTOLOGY, 99

different specimens, and changes during the progress of growth. A
specimen may begin with a narrow cylindrical base, and then sud-
denly spread its end cell into an expanded dish form, or another
may very regularly and gradually dilate into curved, horn-shaped
cells, or the conical calyces of the base, after attaining a certain
diameter, may stop to dilate and continue to grow on, maintain-
ing the same size, into long, cylindrical stems, straight, or curved,
or geniculated by interruptions in the growth, with constrictions
and deflexions. In regularly formed specimens the calyces are
shallow, bell-shaped, with broadly spread margins ; other speci-
mens have deeper calyces, with nearly erect margins. The radial
lamellae are alternately shorter and longer, but equal in size near
the calyx margins, forming a uniform, uninterrupted cycle, with ex-
ception always of a faintly indicated apertural gap and septal
fovea. The longer lamellae extend as somewhat flexuose crests to
the centre. Often a lamella continues across the calyx from the
centre of the apertural gap to the opposite side, and the other
lamellae abut against it from both sides in symmetrical order. The
bottoms of the end cells are usually raised into obtusely rounded
monticulose protrusions, on which the lamellae unite with interlaced!,,
twisted ends ; or sometimes the lamellar crests fade away befQire-
reaching the centre, which then is formed by a smooth, naked spQfc
of narrow extent. The most obvious character of this species are-
the arched carinas extending across the lateral faces of the lamellae
from the outer peripheral side and below, to the upper and inner
edges of the lamellae ; the carinations correspond on both- faces,
and project on the edges of the lamellae as obtuse, transverse bars;
or as acute dentations. The carinas of different specimens vary
considerably in degree of approximation ; in some about eight
carinae are in the space of one centimeter, while others may have
as many as fifteen within the same space. The radiallamellae are
acute, linear, and the interstices between them are completely filled
by vesiculose, transverse plates arranged in imbricated superposi-
tion, in arched rows, ascending from within and below, upward and
outward, diagonally to the direction of the carinae. In the central
area the polyparia are intersected by diaphragmatic, transverse
plates, usually compound, of several pieces, inclosing larger vesicu-
lose, interstitial cavities, which, by intersection with the vertical
lamellae, are divided into cellulose spaces of a much coarser kind

lOO LOWER PENINSULA.

than the interstitial cell spaces of the peripheral area. Associated
with the specimens exhibiting plainly the carinated character of the
lamellce, others entirely similar to them are found with very obscure
carinations. The calyces of the largest specimens attain a diameter
of about six centimeters. The average number of lamellae, in the
circumference of calyces four centimeters wide, is from seventy-five
to eighty-five. The external mode of growth is subject to a great
many variations, from the short, broadly turbinate cell to long, cylin-
drical stems, with all sorts of irregularities by constrictions, flex-
ions, etc. Occurs in the upper Helderberg group, and in the
Hamilton group of Michigan, Canada, New York, Ohio, and in the
Western States. The specimens of different localities and of differ-
ent strata show some differences, but not in a degree to justify
their separation into several species.

Plate XXXV., Upper row. — The three left-hand figures are
medium-sized specimens, found in the Hamilton group of Widder,
C. W. ; the two outer calyces are short, turbinate ; the adjoining
specimen exhibits an irregularly distorted cylindrical growth.
The third upper figure from the left is found in the Hamilton
group of Thunder Bay ; the lamellae on one side of the calyx are
plainly carinated, while on the other side scarcely any traces of
carination can be observed.

CYATHOPHYLLUM JUVENIS, N. Sp.

A very constant form found in association with the preceding
species, resembling it in all particulars, but in all proportions
smaller. The arched carinae are closely approximated, twenty-four
on the space of a centimeter. Number of lamellae from sixty to
seventy in the circumference of calyces two and one quarter centi-
meters wide, which is about the largest size observed. Found in
the Hamilton group of Thunder Bay, Little Traverse Bay, at Wid-
der, C. W. ; also in the upper Helderberg strata of New York,
Ohio, Kentucky, etc.

Plate XXXV., Upper row. — The three smaller specimens on
the right side of the plate ; the longer cylindrical specimen is of
larger size than usual.

PAL^ON TOL OGY. i o I

CYATHOPHYLLUM CORNICULA.
Zaphrentis CORNICULA, Miliie-Edwards.

Single, conical, symmetrically curved polyparia, annulated by
fine wrinkles of growth, and by distant, shallow, rounded constric-
tions ; delicately striate in longitudinal direction by septal furrows ;
apex pointed ; calyx deep, with suberect margins gently spreading
near the edges. Bottom of calyces variable ; there are specimens
in which the calyx gradually narrows into an obtuse pit ; in others
the bottom is reflected into a moderately convex protrusion, on
which the lamellar crests unite ; or this protrusion of the reflected
bottom is of annular form, with a depression in the centre, which is
confluent with a well-developed septal fovea situated on the convex
side of the curvature of the horn-shaped polyp cells. The lamellae
are alternately large and small, denticulated on the edges and
carinated on the side faces ; from sixteen to eighteen carinae on the
space of one centimeter's length. Number of lamellae in calyces
of two centimeters diameter, from seventy to eighty. Lamellar
interstices of the peripheral area filled with vesiculose, transverse
plates up. to the margins of the end cups, but the edges of the
lamellae remain free to some extent, more so than in the former
species. The central area is intersected by well-developed trans-
verse diaphragms, of somewhat irregular compound structure, join-
ing the outer vesiculose area with depressed margins. The largest
sized specimen sare about six centimeters long, by a diameter of four
centimeters at the calycinal margins ; but the majority of specimens
are much smaller. It occurs in the upper Helderberg strata of
Michigan, Ohio, Canada, New York, and in the Western States, a5
one of the most abundant and characteristic fossils of that horizon.

Plate XXXV., Lower row. — The t^-Iiand group of specimens
represents different variations of the kind found in the drift of Ann
Arbor, all in silicified condition, with exception of the upper
largest specimen, which is calcified ; the other specimens are from
the Falls of the Ohio, and from Columbus, Ohio.

I02 LOWER PENINSULA.

CYATHOPHYLLUM SCYPHUS, N. Sp.

Conical polyp cells, symmetrically curved, or irregularly constrict-
ed and geniculated, pointed, or with a broad scar of attachment.
Calyx deep, spacious, with erect margins ; bottom narrowing into
an obtuse point, or somewhat flattened. Lamellae linear, equal
near the margins, but unequal in length, the larger ones uniting in
the centre. The two lateral and the apertural gaps always plainly
indicated ; particularly distinct is the apertural gap, which has no
determined position with regard to the curvature of the polyp cells.
The surface of the lamellae is smooth ; their interstices filled with
vesiculose plates. The central area is transversely septate, by
compound vesiculose diaphragms. Number of lamellae in calyces
three and a half centimeters wide, 125 to 130. Polyp cells of larger
size, measuring about two inches across the calyx and about three
inches in length. Surface longitudinally ribbed by septal furrows,
and intermediate rounded carinae. Found in great numbers in
silicified condition in the lower beds of the Hamilton group, at Long
Lake, north of Alpena. LtU—^

Plate XXXV., Lower row. — The two fight-hand specimens.
One exhibits a view of the calyx, with distinctly visible indication
of the apertural and the two lateral gaps ; the other gives a side
view of a polyp cell.

CYATHOPHYLLUM GENICULATUM, N. Sr.

Large conical polyp cells of much interrupted growth by smaller
constrictions and by deeper abrupt truncations of the old calyces,
and renewed growth from their centre of a new calyx in consider-
ably deflected direction, often making a perfect right angle with
the old cell, which interruptions, frequently repeated, result in the
production of distorted, geniculated, conico-cylindrical polyp stems.
The basal portion of these stems exhibits sometimes a small scar
of attachment at the pointed end ; at other times broad scars, ex-
tending some distance upward along the sides, are noticed on the
lowest cell with truncate base. The latter more permanently at-
tached stems are usually of a more regular, straight, conico-cylin-

PAL.-EONTOLOGY. lox

drical form ; the others, feebly attached stems, by breaking loose
and falling into any accidental position, were obliged to alter the
direction of their calyces, and if by subsequent currents or other
causes their position was changed, they had to accommodate them-
selves again to the new position, and this, I suppose, is the true
reason of their distorted growth. The calyces of the polyp cells are
deep, gradually tapering, with inclined suberect margins. Lamellre
delicate, linear, subequal near the margin, crenulated at the edges,
and obtusely carinated on the side faces. Apertural gap well
marked. Interlamellar interstices of the peripheral area filled with
vesiculose plates. Central area traversed by compound vesiculose
diaphragms, which are much intersected by the vertical lamellae.
Diameter of large calyces from five to six centimeters. Number of
lamellae in calyces four centimeters wide, 112. Found in the upper
shaly strata of the Hamilton group, at Partridge Point, Thunder
Bay.

Plate XXXVI. — Lower figure represents the peculiar mode of
growth of the polyp cells. Some specimens found at Widder, C. W.,
in the Hamilton group, are of entirely similar growth, but these
evidently are only a modified form of Cyathophyllum Hallii, with
obscure lateral carinae.

CYATHOPHYLLUM HOUGHTONI, N. Sp.

Erect, conico-cylindrical polyp cells, with a strong latero-basal at-
tachment. Surface obtusely wrinkled, rarely interrupted by acute
annulations. Calyx deep, with steep side walls, and erect, slightly
dilating edges. Bottom of cells about one third as wide as their
outer margin, subplane or gently convex, with depressed circum-
ference, crossed by the lamellae, of which three or four are always
much stouter than the others and coalesce in the centre. Some-
times the centre of the cell bottoms is depressed, with a ring-like
elevation surrounding the depression, of smooth surface. Lamellae
alternately larger and smaller, linear near the bottom of the calyces,
roof-shaped on the ascending walls, and frequently explanate into a
blistered plicated membrane near the margins. The surface and the

I04 LOWER PENINSULA.

edges of the lamellae within the calyces are covered with granula-
tions and by short, interrupted, transverse carinations or rugosities.
The transformation of the linear radial crests into roof-shaped plica-
tions on the ascending side walls of the calyces alters the structure
of the peripheral area considerably. There are no small, vesiculose,
interstitial plates developed in the interstices between the radial
crests, as in the outer area of other Cyathophylla ; the lamellae
themselves open in two diverging leaves,which join in the interstices
into a continuous calycinal membrane of a blistered structure.
The calycinal surface represents a complete laminar bag folded
into plications, with the acute edges of the folds directed inward,
and the rounded curve turned outward. The coral is formed by
invagination of a series of such bags, which have elongated, blister-
like intervals between them, but are in intimate connection by the
edges of their crested plications, which correspond to each other
and combine into vertical laminar dissepiments extending through
the whole length of the corallum. In the marginal portions of the
calyces, however, the crests are often interrupted in their vertical
continuity by the extension of the blister-like interstices between the
calycinal bags across several of the plications which have lost their
edged crest form through spreading into a tent-shape. This struc-
ture frequently causes an exfoliation of the surface of the speci-
mens, with exposure of the outer blistered surface of the bags, by
which even small fragments can be identified as belonging to this
species. The central area is septate by transverse diaphragmatic
plates of much regularity. The vertical lamellae intersect them as
continuous leaves nearly to the centre. Occurs as the prevailing
species in the Hamilton group of Thunder Bay and of Little Tra-
verse Bay. A coral described by Hall under the name of Chono-
phyllum ellipticum, from the Hamilton group of Iowa, agrees in
structure with the described form, but not with Chonophyllum. A
similarly built species is found in the upper Helderberg strata of
Kentucky, but both of these, according to their mode of growth,
seem to differ specifically from our form.

Plate XXXVI. — In the upper row of figures are views of dif-
ferent specimens found at Little Traverse Bay. The central larger
specimen presents a polished section.

PALEONTOLOGY.

105

CYATHOPHYLLUM RUGOSUM, Milne-Edwards.
Synon., AstR/EA RUGOSA, Hall.

Astraeiform colonies of polygonal, intimately united stems of
a diameter from one to one and .a half centimeter, which in some
specimens of a certain state of preservation are separable, and
present longitudinally ribbed polygonal stems, annulated by trans-
verse wrinkles of growth. Calyces joining, with gradually ascend-
ing side walls, inclosing conical cell pits ; or the end cells are formed
by an abrupt, narrow, central pit, with horizontally expanded, dis-
coid margins. The bottom of the cells is sometimes formed by dia-
phragms with a smooth central spot ; usually the lamellae reach to
the centre and intermingle there, forming a twisted knot. Number
of lamellae in the circumference of the calyces from 35 to 45 ; their
edges are crenulated, the side faces traversed by arched carinae,which
in some specimens are almost obsolete, in others very distinct. In-
terlamellar interstices traversed by small vesicles filling them to
the margins of the calyces. The centre of the stems is transversely
septate by diaphragms, intersected in their outer circumference by
continuous vertical lamellae ; centrally their continuity is inter-
rupted, and the ends are merely carinations on the upper face of the
diaphragms.

Milne-Edwards describes paliform lobes and the development of a
rudimentary columella in this species, but neither one nor the other
structure can be recognized. The centre of the calyces in some
weathered specimens protrudes with a degree of convexity exhibit-
ing the twisted ends of the radial lamellae, but no paliform lobes,
much less a columella. Found in the Helderberg limestones of
Mackinac Island, and in the drift of the Lower Peninsula. It is
also common at the Falls of the Ohio, at Sandusky, and in many
other localities.

Plate XXXVII. — The upper row represents a polished, horizontal
section, and a lateral view of another specimen with stems separable
from each other.

I06 LOWER PENINSULA.

CYATHOPHYLLUM DAVIDSONI.

Synon., AcERVULARiA DAVIDSONI, Milne-Edwards.
ACERVULARIA PROFUNDA, Hall.

The corals described under the name Acervularia Davidson! and
Acerv. profunda, which latter I consider merely as a variety of the
former, are in structure identical with Cyathoph. rugosum. The
genus Acervularia is represented as having its central portion of the
polyp cells surrounded by an internal wall, but neither the above-
mentioned corals nor the typical forms of the genus Acervularia
(Cyath. pentagonum and Cyath. ananas of Goldfuss) exhibit an in-
ternal wall. In the circumference of the abrupt inner cell-pits of
all these forms a sort of annular demarkation is conspicuous in
transverse sections, because the shorter ones of the alternately
larger and smaller radial lamellae terminate there with somewhat
thickened edges, but they never combine into a closed, ring-like
wall.

The specimens described by Milne-Edwards are from the Helder-
berg limestones of the Falls of the Ohio ; the Michigan forms
identified with it in the subsequent description are found in the
Hamilton group.

Growth in large, convex masses, or in lenticular, discoid expan-
sions, covered in the lower depressed, conical, and centrally at-
tached side with a concentrically wrinkled epithecal crust. Stems
multiplying by marginal and central gemmation from the calyces ;
sometimes single stems are free and circular ; usually the growth
is astra^iform, with intimately connected polygonal calyces, sur-
rounded by acute linear crested edges. The margins of the calyces
are usually broadly explanate, discoid, rarely gradually descending
into the more abrupt, bell-shaped, central excavation proper to
all forms, on the rounded bottom of which the lamelhi; unite, or
which, in rarer instances, exhibits a narrow diaphragm sparsely
intersected by lamellar crests. Diameter of calyces about one
centimeter, but quite variable. Lamellae long and short, in alter-
nation, but equal in size near the calyx margins, crenulated at the

PAL^ONTOLOG V. I O 7

edges, and decorated by arched carinse crossing their flanks ; from
thirty-six to forty lamelLx in the circumference of a calyx. In-
terlamellar interstices filled with delicate, transverse, vesiculose
plates. The central area is distinctly septate by diaphragms,
which are not much intersected by vertical crests ; on the circum-
ference of the central area, in polished transverse sections, a
more compact ring is visible, formed by a thickening of the longer
lamellae, and by the abrupt termination of the alternating shorter
ones within this circle, but not a trace of an actual inner wall is
developed. By comparing specimens from different strata and
different localities, a number of minor variations may be observed,
but I do not consider them important enough to make specific dis-
tinctions. This form approaches also so near to Cyathophyllum
rugosum of the upper Helderberg group, that a strict distinction
between them is almost impossible.

Occurs abundantly in the Hamilton strata of Thunder Bay, and
of Little Traverse Bay ; is also a common form in the Hamilton
strata of Iowa.

Plate XXXVH., Fig. 4.

CYATHOPHYLLUM CRISTATUM, N. Sp.

Astraeiform calyces, bell-shaped, joining with polygonal, suberect
margins ; diameter of cells about two centimeters ; about thirty-six
alternately large and small stout lamella in the circumference, with
crenulated edges and lateral carinations ; the larger lamellae ex-
tend over the bottom of the cells to the centre ; interlamellar inter-
stices large, filled with coarse, transverse, vesiculose plates. Central
area irregularly septate by vesiculose compound diaphragms. Oc-
curs rarely in the Hamilton strata of Little Traverse Bay ; its
structure is much coarser than in Cyathophyllum Davidsoni, with
which it is associated.

The specimens were not sufficiently perfect for photographic
delineation.

CYATHOPHYLLUM COALITUM, N. Sp.

Astraeiform masses of very large, polygonal polyp cells measuring
about four centimeters in diameter, each one surrounded by its

I08 LOWER PENINSULA.

own complete wall. Surface of calyces expanded, discoid, with an
abrupt but shallow central pit, the reversed bottom of which con-
ically projects, covered by the central ends of the radial crests.
Lamellae linear, subequal, from sixty to seventy in the circum-
ference of a calyx, crenulated by transverse trabeculae (bars), which
are the ends of lateral, arched carinae decorating the side faces ;
about fourteen carinae on the length of one centimeter. Inter-
stitial spaces filled with vesicles arranged in arched rows run-
ning diagonally across the carinations. Central area traversed by
transverse, larger plates, which are much intersected by the ver-
tical lamellae. The structure of this coral is identical with Cyatho-
phyllum Hallii, from which it differs principally in its cespitose,
compound growth. Found frequently in silicified condition in the
drift, connected with fossils of the corniferous limestone.

Plate XXXVIII.' — Fig. 4 represents a fragmentary specimen
from the drift of Ann Arbor.

CYATHOPHYLLUM RADICULA, N. Sp.

Small single polyp stems, about one centimeter in diameter, coni-
cal at the base, cylindrical in their prolongation, annulated by
numerous sharp constrictions caused by periodical interruptions in
the growth of the cells, which commences again with contracted
base from the centre of the old cells. The bases of the stems are
strongly attached to other bodies, and the attachment is often
strengthened by excrescences from the sides of the stems. Calyces
not as deep as wide, with erect, ascending sides, slightly expanded
near the margins, and. surrounded by about sixty alternately larger
and smaller crenulated lamellae. Bottom of cells flat, formed of
a smooth or faintly carinated or granulose transverse diaphragm ;
in some other specimens the lamellae extend to the centre, and the
bottoms of the cells are more rounded, concave. A septal fovea
is rarely indicated. Found in the Niagara group of Drummond's
Island, at Point Detour, and in the Niagara group of Iowa.

Plate XXXIX., Fig. 3. — The left-hand, outer vertical row of
specimens is from Point Detour ; the central row represents speci-
mens from Masonville, Iowa ; the right-hand row may be a different
species. It occurs in the Niagara group of Louisville, and of Charles-

PALAEONTOLOGY. IO9

ton, Indiana ; the stems are of longer cylindrical growth, often
curved and geniculated ; their calyces rarely exhibit a naked dia-
phragm in the bottom, and the crenulated lamellae generally reach
to the centre. The surface of the stems is in both kinds longitu-
dinally ribbed by septal striae.

CLISIOPHYLLUM, Dana.

Simple conical polyp cells with the general structure of Cyatho-
phyllum, differing from it in the shape of the calycinal bottom.
Radial lamellae linear, with prominent free edges within the end
cells ; the interstices between the lamellae are traversed by trans-
verse, vesiculose plates, but these do not fill the interstices up to
the margins of the lamellae, as is usual in Cyathophyllum, and the
inclosed vesiculose spaces are somewhat larger. The broad central
area of the polyp cells is formed of high, projecting, conical dia-
phragms, one incasing the other, and crested on the surface by the
central ends of the radial lamellae. The apertural septal fovea
well developed,

CLISIOPHYLLUM ONEIDAENSE, Billings.

Conico-cylindrical, sometimes elliptically compressed polyparia,
annulated by numerous transverse wrinkles and intermediate linear
constrictions. The stems are frequently flexuose ; their width is
from three to five centimeters, by a length of sometimes over one
foot in cylindrical specimens ; the conical cells are shorter, by a
diameter equal to that of the former. The basal ends of the larger
stems often, for some length, grow in the form of narrow cylindrical
pedicles, the surface of which is ornamented with numerous stout
spinulose projections, which also extend, but rarely, for some dis-
tance higher over the upper, more dilating portions of the stems.
The calyces are spacious, with steep side walls, terminating with
erect or only slightly expatiated margins. Lamellae near the
calycinal margins of alternately larger and smaller size ; further
down the sides the lamellae are all of one size ; the smaller inter-
calated ones remain confined to the outer margin. A conspicuous
septal fovea interrupts the cycle of the lamellar crests, causing a

no LOWER PENINSULA.

deep, siphonal depression in the peripheral circumference of the
cell bottoms, which are broad, rising into a strong cone carinated
by the radial lamellae uniting on its apex in somewhat twisted
manner. Number of lamellae in specimens of four centimeters
calyx diameter, from 85 to 90, and at the margins of the calyces an
equal number of small rudimentary folds are intercalated.

Found in the upper Helderberg strata of Mackinac, at the Falls
of the Ohio, at Port Colborne, in Canada, and frequently in the
drift deposits.

Plate XL. — The upper row represents various silicified specimens
found in the drift, left-hand and lower central specimen ; the other
two are from the Falls of the Ohio. The right-hand specimen exhib-
its the invaginated, conical diaphragms almost extending across the
whole width of the stems, surrounded only by a narrow peripheral
area.

LITHOSTROTION, Flemming.

Compound polyparia, formed of cylindrical stems, enveloped by a
perfect epithecal wall, and either loosely approximated, with cir-
cular orifices, or intimately united, and joining under polygonal
outlines by mutual pressure. Structure very similar to Clisio-
phyllum. The outer area is divided into small cellulose spaces
by the interposition of vesiculose, transverse plates between the
vertical lamellae ; the inner area, which is not defined from the outer
area by an intervening wall, is formed by diaphragms reflected into
large protruding cones, carinated by the radial crests uniting on
them and invaginating into one another. The laterally compressed,
crest-like apices of the invaginated cones grow together and form
a continuous, thin axal lamina pervading the whole length of the
corallum.

LITHOSTROTION MAMILLARE, Edwards & Haime.

LITHOSTROTION PROLIFERUM, Hall.

Large colonies of remote, cylindrical stems, from one to two and
a half centimeters in diameter, multiplying by gemmation from
the margins of the cal)xinal disks, or astraeiform masses of inti-

PAL^ONTOLOG V. Ill

mately united, polygonal stems of similarly variable sizes, and
unequal in the same specimens through the intermixture of fre-
quent young cells. Calyces moderately deep, obliquely spreading
in the margins, and more abruptly excavated in the inner circumfer-
ence. Bottom of cups reflected into a large, conical protuberance,
carinated on the sides by the converging ends of the radial lamellne,
and terminating with a laterally compressed cristiform edge.
From thirty to forty lamella in the circumference of a calyx ; and
sometimes indications of rudimentary, intermediate plications are
noticeable. The clusters of singly growing stems cover sometimes
spaces of large extent, and not a specimen with astraeiform, poly-
gonal calyces is found among them ; in other localities the astrsei-
form colonies are the prevailing form ; this seems to indicate a
difference between the two forms, but specimens are found, and
that not rarely, in which one part of the stems is free, circular, and
another intimately united, pressing each other into the polygonal
form. As no difference in the structure can be observed in the
two forms, I am inclined to consider them modifications of one
species, whose difference in mode of growth is perhaps only de
pendent upon local conditions existing at one and another place.
Occurs in the carboniferous limestone of Wildfowl Bay, and at
Bellevue and Grand Rapids, Michigan.

Plate LV.^ — The upper row represents two specimens from the
carboniferous limestone of Wildfowl Bay — one with astraeiform,
polygonal calyces, the other with partial free circular stems.

The specimen lying across the bottom of the lower row in the
same plate is a singly grown stem of the same species.

BLOTHROPHYLLUM, Billings.

Conico-cylindrical polyparia, single, or in cespitose clusters, pro-
duced by prolific calycinal gemmation of a few parent cells. The
structure of the stems, as being built of a series of invaginated
cups, is particularly obvious. The bottom of these cups has the
shape of transverse diaphragms, smooth in the centre, or super-
ficially carinated by the central ends of the radial, crest-like folds,
into which the side walls of the cups are plicated. These crests of
the superimposed cups unite into continuous vertical laminae within

112 LOWER PENINSULA.

a narrow circle intermediate between the central and the peripheral
areas, but are interrupted in their continuity outside or inside of it.
Inside, on the diaphragms, the plications fade away as superficial,
low carinations ; in the outer peripheral area their continuity is in-
terrupted for other reasons ; the margins of the incased plicated
cell cups dissolve connection and begin to diverge ; gradually widen-
ing gaps open between the laminar cup margins, which at first
continue to repose on each other's crests, but finally also these
become disjunct, and they remain so until at the periphera
surface the edges of the cup membranes join again into a com-
mon epithecal wall, which closes off from the outside the cavern-
ous gaps between them. Some of the forms have a well-developed
septal fovea ; in others it is not very distinct.

BLOTHROPHYLLUM DECORTICATUM, Billings.

Large polyp stems, conical at the base, cylindrical and flexuose
above, attaining a diameter of over two inches and a length exceed-
ing one foot. Surface, if perfect, covered by a continuous epithecal
crust, longitudinally striate by septal furrows and annulated by
deep wrinkles and constrictions. The conical basal part is deco-
rated with strong nodular spinulosities, as the polyp cells of the
associated Clisiophyllum, with which it stands in structural rela-
tionship. Calyces moderately deep, with steep sides, explanate
margins, and broad bottoms, in the form of irregularly concave
diaphragms, smooth in the centre, and on one side depressed into
a deep septal fovea. The lamelhc are acute, very prominent
linear crests on the ascending side walls of the calyces, but become
lower and almost obsolete near the expanded peripheral margins ;
in the broad marginal interstices between them smaller plications
are regularly intercalated.

The peripheral part of the polyparia formed by the expanded
laminar cup margins, with large gaps between them, and supported
only by their ends, united in an epithecal cuticle, is very fragile
and rarely found in good preservation. The plurality of speci-
mens have lost their epitheca, and the laminar margins stand out
free, surrounding the stems like broad collars ; or they have been
destroyed, and only the central cores arc found, presenting an ex-

PAL.-EONTOLOG V. I I 3

foliated surface, and consisting of a cycle of stout vertical lamella,*,
which incloses the central series of diaphragms. Occurs in the
drift of Michigan, and is found in place at the Falls of the Ohio,
and in the corniferous strata of Canada.

Plate XLI. — Silicified specimens from the Falls of the Ohio. The
right-hand weathered specimen exhibits the centre of a polyp
stem intersected by diaphragms. The left-hand specimen has at
the conical base preserved its continuous epithecal wall ; above
it the surface is exfoliated and shows the coarse, blister-like cavi-
ties intermediate between the invaginated series of renewed cell
cups.

BLOTHROPHYLLUM C^SPITOSUM, N. Sp.

Aggregated, conico-cylindrical polyp cells of a much interrupted,
articulated growth, by constantly repeating constrictions and dilata-
tions of the cell cups. The constrictions of the stems are acute
angular, without interruption of the continuity of the surface walls ;
in other instances the continuity is interrupted, and a more or less
broad, expanded rim of the older cell cup projects with free edge at
the places of constriction. The polyparia multiply by gemm.ation
of many young cells at once from the end cups of the older stems,
The clustered stems become attached to each other by their acute,
annular edges ; the joints of the obliquely diverging stems are gen-
erally oblique to each other in proportion to the inclination of the
stems — one joint, so to say, being pushed sideways over the other in
this direction. The calyces are shallow, with obliquely spreading
side walls. Radial crests not very high, linear, and projecting most
on the more vertical portions of the cup walls, dilating into tent form
on the marginal, expanded portions of the calyces. Edges of the pli-
cations denticulate and surface granulose. At the margins of the
calyces smaller, rudimentary plications are alternately interposed
between the larger ones. Diaphragm.s forming the bottom of the
cups flat, w^ith several siphonal depressions in their circumference,
but with no distinct septal fovea ; their centre usually smooth,
sometimes carinated by the ends of the lamelL-e. By the united
linear, crest-like portion of the plications a cycle of vertical lamella;
is formed around the central diaphragms ; the area exterior to this
cycle is formed by superimposed, plicate, sometimes blistered,
8

114 LOWER PENINSULA.

laminar cup-walls, partially connected by the edges of the lamelL-e,
otherwise separated by irregular, blister-like cavities, but uniting
again in the peripheral wall. Diameter of stems from two to three
centimeters. Found in the Niagara group of Drummond's Island,
at Point Detour, etc., in silicified, generally much decayed and
altered condition.

Plate XLII. — Surface view and lateral view of specimens from
Point Detour.

CHONOPHYLLUM, Milne-Edwards.

Single turbinate polyparia, composed of invaginated, radially
plicated cell cups, which are intimately united within the central
area, and form with their linear plications continuous vertical
crests, extending through the whole length of the corallum, and
uniting in the centre into a somewhat twisted fascicle, but without
composing a solid central axis. The interlamellar interstices of
this central fascicle or core are traversed by transverse vesiculose
plates, but no larger transverse diaphragmatic septa are observable.
In the peripheral area the structure is entirely different. The con-
nection between the invaginated cups becomes more loose, the
linear plications open themselves and spread horizontally, forming
gradually widening and moderately convex, band-like folds of the
expanded laminar cup walls, which are superimposed in well-defined,
membraniform layers, one reposing on the granulose prominences
of the surface of another, and more intimately connecting in the
linear furrows between the plications, which correspond to the
interlamellar spaces of other Zoantharia rugosa, but were confused
by Billings with the lamella;. In his description of Chonophyllum
magnificum, Mr. Billings remarks : " The grooves on the floor of the
cup indicate the position of the septa, and the ridges are the equiv-
alent of the interseptal spaces." This is an evident error. It can
be directly observed in the specimens how the linear vertical crests
of the central area gradually open in two diverging leaves, spread-
ing horizontally into flattened, band-like folds, and at the same
time how the spacious interlamellar interstices of the central circle
become outwardly angustated in the same measure as the plications
widen. In the median line of these linear interstitial spaces, con-
founded with the lamclLx, the rows of vesiculose transverse plates,

P ALTEON TO LOG V. I I 5

characterizing them as true interstitial spaces, are, in all the well
preserved specimens, plainly demonstrable, anatomical facts.

CHONOPHYLLUM MAGNIFICUM, Billings.

Conical polyparia, attaining a calyx diameter of nine inches in
larger specimens ; some grow in short, broadly expanded polypdoms,
increasing but little in length ; others proportionately elongate
their stems with the widening of their calyces. The pointed ends
of the polyparia are attached by a small scar. The outer wall is
annulated by concentric wrinkles of growth and longitudinally
ribbed by septal striae. Calyces broad, explanate, dish-shaped.
Plications equal, linear, crest-like in the central parts of the calyces,
but changing into tent-shape on the spreading neck part, and open-
ing into broad bands near their peripheral circumference. The
surface of the plications is densely covered with decorative granu-
lations or papilli, visible as well on the horizontal, band-like surface
as on the side faces of the linear, crest-like portions. In calyces of
three inches diameter about ninety plications are counted in the
circumference. In the bottom of the calyces the lamellae become
very delicately linear and twisted, or irregularly interlacing into a
central fascicle. No indication of a septal fovea. Occurs in the
upper strata of Mackinac Island and in the drift of the Lower Pen-
insula, and is common at the Falls of the Ohio, at Charleston
Landing, Indiana, and in other exposures of the upper Helderberg
group.

Plate XLIIL, Upper row. — The right-hand specimen is a silicified
fragment of a large calyx exhibiting the band-like form of the
lamellae toward the outer margin, and their crested linear form
near the central cavity ; the papillose surface is likewise well seen
in the figure. The other specimen gives a side view of a specimen
showing the general mode of growth, and the laminated structure
of the polyparia. The right-hand figure in the lower row is a calyx
seen from above. All the specimens represented are from the Falls
of the Ohio ; the Michigan specimens were not so well adapted for
delineation.

Il6 LOWER PENINSULA.

CHONOPHYLLUM PONDEROSUM, N. Sp.

Patellate, depressed, conical polyparia of irregular, unsymmetrical,
clumsy growth, with gemmation from the centre of the calyces, of
single new cells, or, in rare instances, of from two to four confluent
or imperfectly defined calyces. End cells shallow, explanate at the
margins, more abruptly depressed in the centre, which is surrounded
by a cycle of low linear crests uniting in it with twisted ends.
Expanded marginal part radiated by flat, broad, band-like plica-
tions of papillose Kurfa ce. The' specimens are all formed of a heavy,
compact mass of amorphous, white, ivory-like carbonate of lime, or
partially silicified, and with scarcely a trace of the organic structure
preserved ; only in a few specimens could enough of it be seen by
which to recognize the generic relations of the specimens and their
correspondence with Chonophyllum. It does not seem to be the
mode of petrification which obscures the structure, as we find this
coral in many different localities associated with other corals ex-
hibiting the finest details of structure, while they everywhere pre-
sent the same massive, compact condition. The coral appears to
have, during the progress of its growth, filled out all its cellulose
cavities as soon as the fleshy parts of the animal abandoned them.

It occurs rarely in the upper Helderberg limestones, but is abun-
dant in certain layers of the Hamilton group of Thunder Bay, and
is also found in Little Traverse Bay.

Plate XLIII., Lower row. — The left-hand figure is a specimen
found in the lower limestones of Phelps' quarries, near Alpena.

OMPHYMA RAFINESOUE, PTYCHOPHYLLUM IN
PART E, M I LNE-El ) WA R I )S.

Single conical polyp cells of Cyathophylloid structure, composed
of invaginated calycinal cups, the bottoms of which have the form
of spacious diaphragms, either smooth or crested by the radial
lamella," uniting in the centre. The ascending side walls of the
cups are encircled by linear, crest-like plications, Avhich connect into
uninterrupted vertical laminae, within this intermediate area. At
the peripheral cup margins the plications become tent-shaped, cm-

I PAL^ONTOLOG Y. I i 7

bracing one another in their superposition, but not always com-
bining with their edges into uninterrupted vertical leaves. The
interlamellar interstices are traversed by transverse plates, and
divided into cellulose spaces, but the dissepiments are not inde-
pendent vesiculose leaflets ; they make part of the tent-shaped folds
of the invaginatcd series of cell cups, and represent the rounded,
outwardly directed flexion of the plicated cup walls, while the in-
wardly turned folds are sharply crested. Root-like, cylindrical ex-
crescences from the side walls of the polyparia, by which they are
attached to other bodies, are a peculiarity of the different species of
Omphyma, which, however, are not exclusively so to them, but are
also noticed in other forms of the Cyathophylloid family. As
another distinctive character of Omphyma, the development of four
septal foveae is mentioned by Milne-Edwards, but they are generally
not all equally distinct, while very frequently only one of them is
obvious, the others being almost obsolete. The genus Ptycho-
phyllum, described by Milne-Edwards as being organized like
Chonophyllum, differing from it in the twisted converging ends of
the radial lamellae, forming a central false columella, is likewise in
close structural relationship with Omphyma, and in the special
case of Ptychophyllum Stockesii. I found its afifinity with Om-
phyma verrucosa so great that I altered the name of the first from
Ptychophyllum to Omphyma.

OMPHYMA VERRUCOSA, Milne-Edwards.

Conical polyparia, attaining in larger specimens the length of
one decimeter by a calyx diameter of from seven to eight centi-
meters. Surface of the silicified specimens generally exfoliated ; if
perfect, it is covered by an epithecal wall with annular wrinkles of
growth, and longitudinally striate by septal furrows. From the
sides of the conical walls numerous cylindrical, root-like prolon-
gations grow out, serving for attachment of the coral to other
bodies ; these appendices were not distributed equally over the sur-
face, but seemed to form only on those sides where a chance for
attachment was offered by close proximity of an object. Calyces
spacious, with steeply ascending sides and a gently expanded mar-
gin ; bottom broad, convex, with depressed circumference, flat or
somewhat concave in the centre, which may be almost smooth, or

Il8 LOWER PENINSULA.

the lamellae may extend over it as carinations, becoming twisted in
the centre. On the ascending sides of the calyx the lamellae have
the form of acute linear laminae alternating in size, a smaller and a
larger one near the bottom of the calyx always vmited into pairs.
In the marginal portions of the calyces, the two plates forming the
linear crests diverge at the base, and open into a tent-shape. The
four septal foveaeare scarcely ever distinct — two of them, or it may
be only one, being plainly developed.

The centre of the polyparia is, in vertical sections, seen regularly
intersected by large transverse plates, and the continuity of the
vertical crests is interrupted. Number of lamellae in calyces of six
or seven centimeters diameter from one hundred to one hundred
and ten. Associated with the elongated type form already de-
scribed, which is represented on Plate XLIV., lower row, right- and
left-hand specimens, are shorter conical specimens, w^ith broad, ex-
panded calyx margins, and generally with a very prominent bot-
tom, covered by twisted radial crests, seeming to be a mere variety
of the former kind. The central figure between the two repre-
sents one of them. Occurs in the Niagara group of Drummond's
Island, etc.

OMPHYMA STOCKESII.

Synon., Ptychophyllum Stockesii, Milne-Edwards.

Conical polyp cells very similar to the former species, in structure
and mode of growth. Calyces spacious, rather shallow, with ex-
panded margins ; bottom of cells always raised into a monticule,
on vv'hich the lamellae unite in twisted manner. Two of the septal
foveae distinct, the other two obscure. Lamellae united into pairs
of a larger and a smaller one ; of more delicate structure than in
the former kind, and with narrower interstices. Their vertical con-
tinuity is complete in an inner intermediate cycle ; interrupted in
the central part, occupied by transverse diaphragms, and in the
marginal parts, in which the horizontally expanded cup membranes
are bent into zigzag lines, and superimposed in layers. Number of
lamelljE somewhat larger than in the former species in specimens
of the same size. External surface covered with root-like ex-
crescences as in the other. The description given by Edwards of

PAL^EONTOLOG V.

119

Ptychophyllum Stockesii says nothing about such excrescences,
but otherwise it applies exactly to the specimens now considered,
which were found in the same locality as his, at Drummond's
Island, associated with the other form. Other forms of Ptycho-
phyllum, found at Louisville, in the Niagara group, and resembling
PtycJwpJiylhun patcllatiun from Gothland, have these root-like ap
pendices also well developed. It is sometimes difificult to draw a
line of distinction between specimens of these two species.

Plate XLIV., upper row, gives various silicified specimens from
the Niagara group of Drummond's Island.

A very common species in the Niagara group of Iowa, described
by D. Dale Owen, under the name of CyatJiophyUiini iindnlatiivi ct
midtiplicatuni, has a structure entirely conformable with the two
species of Omphyma of Drummond's Island, and must therefore be
arranged with them in the same generic group*

DIPHYPHYLLUM, Lonsdale.

Synon., Eridophvllum, Milne-Edwards.

DiPLOPHVLLUM, Hall.

' Colonies of aggregated cylindrical polyp cells, multiplying by caly-
cinal gemmation, but not by fissiparous mode of propagation, as
Lonsdale asserts. The stems are rarely in intimate contact so as
to form astraeiform masses ; usually some interval remains between
them, and they are mutually connected by rugose or radiciform
lateral prolongations of the walls, or by floors formed by periodical
horizontal expansions of the calyx margins until they join at their
edges. Structure of cells biareal. The outer area is formed by the
external epithecal wall with a cycle of stout vertical lamellae having
crenulated edges and arched carinre decorating their flanks. The
interlamellar interstices are filled with small transverse plates, divid-
ing them into narrow cellulose spaces. These transverse plates are
disposed in arched rows, crossing the arched carinae diagonally
from within and below, upwardly and outwardly. The inner area
is principally composed of flat, transverse diaphragms, which are
only in their circumference intersected by the radial lamellae ; their
centre is free of the crests, or the crests extend only on their upper

120 LOWER PENINSULA.

surface to the centre. There are three different modifications in
the structure. In one the demarkation of an inner and an outer
area is very obscure ; the vertical lamellae reach to the centre of
the diaphragms as superficial carinae. These are exclusively
Silurian forms, which might be distinguished as a peculiar generic
type, but as their general mode of growth is so similar to the other
biareal forms of Diphyphyllum, I prefer to leave them together.
A second modification has a very broad central area, formed almost
exclusively by transverse diaphragms, while the vertical lamellae
are confined to a narrow peripheral cycle ; but the inner and outer
cycle is not defined by an intermediate internal vertical wall. The
third modification, which is generally of stouter growth than the
second form, has the inner area defined from the outer by a dis-
tinct vertical wall of horseshoe shape, open on the side of the
apertural fovea. The lamellae in this latter form never transgress
the inner wall, and the central part within is exclusively formed
by a superimposed series of transverse diaphragmatic plates.

DIPHYPHYLLUM HURONICUM, N. Sp.

Aggregated, cylindrical, flexuose stems of a diameter of from one
to two centimeters, annulated by delicate striae of growth, and by
deeper wrinkles and constrictions ; longitudinally ribbed by septal
furrows. The stems are laterally connected by stout rugose prolong-
ations from their walls, which in all the stems of a colony are uni-
formly directed to one side. Calyces moderately deep, dish-shaped,
with explanate margins, radiated by about sixty linear lamella:,
which unite in a central fascicle ; their margins are faintly cren-
ulated, or not so at all. Interstices filled with vesiculose plates,
which in the central part are larger and inclose somewhat coarser
cell spaces, but no distinct large plates, properly deserving the
name of diaphragms, are developed, and the outer and inner area
are not well defined. The stems multipl}' by gemmation from the
centre and the margins of the end cells, the marginal gemma; re-
maining for a good while of a more slender, smaller size than the
contemporaneous new cells sprouting from the centre. Found in
the Niagara group of Drummond's Island and Point Detour.

Plate XLV. — P'ig. i represents a side view of a cluster of stems
found at Point Detour.

PALJZONTOLOG V. i 2 1

DIPHYPHYLLUM RUGOSUM, Milne-Edwards.
Eridophyllum RUGOSUM, Milne-Edwards.

Of v^ery similar sructure to the former, but its stems are smaller,
less than one centimeter in thickness ; the g-emmation from the
calyces is very prolific ; from four to six gemma; grow at once from
an end cup ; the stems are tortuous, geniculated, annulated by
sub-regularly repeating constrictions, and by delicate linear strise of
growth ; the lateral processes, for mutual attachment of the stems,
are acanthiform, quite numerous. Calyces forming rounded,
moderately deep excavations with slanting sides and erect margins.
Lamellae crenulated, from forty to fifty in the circumference of a
calyx, and extending nearly to its centre, which is generally formed
by a very narrow diaphragm, not transgressed by the lamellae, but
not separated from the outer area hy an internal wall.

This species is not found in Michigan, but is a very common form
in the Niagara group of Indiana and Kentucky, and because of its
close afifinity to the former species, I have considered it of interest
to describe and represent it in this place.

Plate XLV. — Fig. 2 gives a side view of a silicified specimen from
the vicinity of Louisville ; the stems are of somewhat larger size
than the specimens usually have.

DIPHYPHYLLUM MULTICAULE, Hall.

Syringopora multicaulis, Hall.

Flexuose cylindrical stems, from three to four millimeters in di-
meter, distant from each other about one tube diameter, connected
by narrow, remote spurs resembling the transverse tubules of a
Syringopora. Surface faintly ribbed by septal striae, and encircled
by wrinkles of growth. Calyces deep, with almost vertically erect
walls, radiated by about thirty crenulated lamellae, of which half the
number are marginal ; the others reach to the centre. Interstitial
spaces filled with vesiculose plates. Diaphragms generally obscured
by frequent intersection with the lamellae ; more rarely the central

122 LOWER PENINSULA.

area is occupied by a flat diaphragm free of crests. I was at first
inclined to consider the latter form "as a separate species, but I
found later that these differences constitute only individual vari-
ations of the same form.

Found in the Niagara group of Point Detour, Scul Choix, on
Lake Michigan, and in the drift boulders of the Lower Peninsula.

Plate XLV. —Fig. 3 is a specimen with plainly developed trans-
verse diaphragms ; in Fig. 4 the lamellae extend to the centre,
and the diaphragms are obscure. Both specimens are found in the
drift of Ann Arbor.

DIPHYPHYLLUM SIMCOENSE, Billings.
Synon., Eridophyllum Simcoense, Billings.

DIPHYPHYLLUM STRAMINEUM, Billings.

Colonies of cylindrical, subparallel, straight or flexuose stems,
closely aggregated or more distant from each other, varying in
different specimens in diameter from three to six millimeters.
Surface longitudinally ribbed and annulated by wrinkles of growth.
The stems laterally connect by slender transverse processes, similar
to the transverse tubules of Syringopora— not, however, making
communication between the visceral cavities, as in those, but
merely fastening externally to the walls for mutual support, ac-
cording to the necessity ; in some places these are numerous
and crowded, in others considerably distant. Calyces deep, with
erect sides and slightly dilating margins, surrounded by about
forty crenulated lamellae of equal size near the margins, but alter-
nately longer and shorter in the bottom part of the calyces. In
some specimens these are almost totally restricted to a narrow
marginal cycle, and the centre is occupied by flat, broad dia-
phragms with depressed circumference ; in other specimens the
larger lamellre extend nearly or completely to the centre, and in-
tersect the diaphragms as continuous vertical leaves. The same
specimens often exhibit tubes with both variations of structure,
plainly demonstrating how little importance can be placed in some
cases on the degree in development and extension of the vertical

PALEONTOLOGY. 1 23

crests. The intcrlamellar interstices of the peripheral area arc
traversed by vesiculose plates ; the central area, principally formed
by transverse diaphragms, is not defined from the peripheral cycle
by an internal wall. Gemmation calycinal, producing single forked
branches or a number of young calyces sprouting at once from the
end cells. Occurs in the upper Helderberg limestone of Mackinac,
and in the corniferous strata of Canada, New York, Ohio, and in
the Western States ; likewise found frequently in the drift of the
Lower Peninsula.

Plate XLVI., Upper row. — The left-hand figure represents a
specimen found in the drift, with tubes smaller than usual ; it is in
all probability identical \N\ih. Diphyphylluni stra7nincuin, Billings. The
two lower figures are different views of one specimen with larger
tubes, agreeing with the type form of Eridophyllum Simcoense,
described by Billings. It was found in the corniferous limestone
of Caledonia, N. Y.

DIPHYPHYLLUM RECTISEPTATUM, N. Sp.

Cylindrical, closely aggregated, subflexuose stems, from five to
seven millimeters in diameter. Calyces with erect, vertically ascend-
ing side walls, and a broad bottom formed by flat diaphragms de-
pressed in their circumference and smooth in the centre. Lamellae
stout, alternating in size, not crenulated, about thirty-six in the
circumference of a calyx ; the larger ones extend over the marginal
parts of the diaphragms. Diaphragms remarkably regular, extend-
ing nearly across the entire width of the stems, meeting near the
outer walls with a very narrow peripheral cycle of more minutely
cellulose structure, formed by intersection of the intcrlamellar
spaces with ascending rows of small, transverse, vesiculose plates.
The species has much resemblance to Diphyphyllum latiseptatum
of McCoy. Occurs in the lowest horizon of the Hamilton group,
near Craford's quarry, at Middle Island, Presque Isle Lighthouse,
etc. Not figured.

124 LOWER PENINSULA.

DIPHYPHYLLUM PANICUM.
Synon,, Cvathophyllum panicum, Winchell.

Large colonies of diverging, partially contiguous cylindrical stems
of about one centimeter in diameter, multiplying by prolific caly-
cinal gemmation. Stems longitudinally striate and transversely
wrinkled by lines of growth, and, periodically, by deeper incid-
ing constrictions. Calyces deep, with steep side walls and slightly
expanded margins. Bottom of calyces occupying about one third
of the diameter of the stems, formed of vesiculose compound dia-
phragms, which are only in their peripheral circumference intersect-
ed by vertical lamellae. Lamellae crenulated at the edges and deco-
rated on the sides with arched carinas, from forty to fifty in the
circumference of a calyx. Peripheral area filled with small inter-
lamellar vesicles ; the two areas are not defined from each other
by an intervening wall. Found in the upper part of the Hamilton
group, in the lime quarries near Petosky, and on Little Traverse
Bay.

Plate XLVIL, Fig. 3. — Two fragments, one exhibiting a vertical
section through the stems, the other giving the exterior surface
of the stems.

DIPHYPHYLLUM GIGAS, N. Sp.

Large cylindrical stems, sometimes over one inch in diameter,
growing in cespitose colonies, and multiplying by prolific calycinal
gemmation of the stems. Surface covered with annular wrinkles, by
which the stems attach themselves to one another. Longitudinal
septal strirc very distinct. Calyces deep, with steep side walls and
gently expanded margins, surrounded by about eighty subequal
lamellae crenulated at the edges by the development of arched
lateral carinae. Interlamellar interstices of the outer area filled
with small, transverse, vesiculose plates. Bottom of calyces formed
by flat diaphragms, smooth in the centre, and intersected in the
circumference by the vertical lamellae ; no defining walls between

PALyEONTOLOG V.

125

the outer and inner area. Found [in association with fossils of
the corniferous limestone, in the drift 'deposits of Michigan.

Plate XLVL, Upper row, right-hand figure. — Diphyphyllum
(Eridophyllum) Verneuilli, a species with stems intermediate in
size between this form and Diphyphyllum Simcoense, is likewise
not uncommon in the drift boulders belonging to the corniferous
limestone formation. Its central area, formed of smooth transverse
diaphragms, is defined from the peripheral cycle by an internal wall,
more or less distinctly developed. Not figured.

DIPHYPHYLLUM ARCHIACI, Billings.

Synon., Eridophyllum strictum (?) Milne-Edwards.

Cylindrical stems, multiplying by calycinal gemmation, with a
diameter of from one to two centimeters, transversely wrinkled by
fine striae of growth and longitudinally ribbed by septal rugse ; in
some specimens the stems are articulated by abrupt constrictions,
and moderately distant ; in others the growth is more uniform
and the stems are in closer approximation, partly touching with
their sides. Calyces generally bell-shaped, with steep sides and
gently dilating margins ; sometimes more shallow and of ex-
panded form. Lamellae crenulated by the ends of the arched
carinas decorating their sides, fifty to sixty in the circumference of
a calyx, subequal near the margins, but alternately longer and
shorter ; the longer ones abut against a narrow inner wall formed
like a horseshoe, which incloses fiat transverse diaphragms ; the
aperture of' the horseshoe is coincident with the principal septal
gap. The interstices of the peripheral cycle of lamellae are divided
into small cellulose spaces by transverse vesiculose plates. Occurs
in the upper Helderberg limestones of Michigan and Ohio, and in
the Hamilton group of Thunder Bay ; likewise in Bosanquet town-
ship, Canada. The specimens from different localities vary some-
what, but agree in general so well that a specific distinction can not
be made with propriety. The Helderberg form, which I have identi-
fied with this species, is probably the same with Eridophyllum
strictum, Milne-Edwards.

Plate XLVIL, Upper row. — The left-hand figure is a polished

126 LOWER PENINSULA.

transverse section through a specimen from the upper Helderberg
group, exhibiting the narrow horseshoe-shaped inner walls. The
right-hand specimen, found in the same locality, exhibits a side
view of the stems, interrupted by constrictions. The vertically
intersected central stems have the narrow central area and the
lateral carinations of the lamellse well exposed. The right-hand
figure in the lower row of the same plate represents a cluster of
stems found in the Hamilton group of Alpena, with well-preserved
end cells.

DIPHYPHYLLUM COLLIGATUM.

HELIOPHYLLUM COLLIGATUM, Billings.

Colonies of subparallel stems of the structure of Diphyphyllum,
with an internal narrow wall separating the outer finely cellulose
from an inner transversely septate area. The growth of these
colonies is entirely peculiar; the stems are regularly articulated
by deep constrictions, in which constricted parts they are free. In
alternation with these constrictions, the calyces become broadly
expanded at certain levels, coincident in all the tubes of the colony,
and join ^^■ith their margins under polygonal outlines in a contin-
uous floor of astraeiform aspect. At a subsequent period the sur-
face of the expanded calyces becomes covered up by an epithecal
crust, and from the centre of each of the old calyces a new calyx
grows with a contracted base, rapidly dilating above, in order to
meet the others again in a common floor, which contractions and
expansions follow each other in constant succession. The calyces
are radiated by about fifty crenulated lamellae, equal near the
margins, but alternately longer and shorter on the sides of the
calyces ; the longer ones abut against the narrow inner wall.
Found in the upper Helderberg limestones of Michigan, Canada,
and at the Falls of the Ohio.

Plate XXXVIU — P^ig. 3 represents a side view of two silicificd
fragments from the drift of Ann Arbor.

PAL.^ONTOLOG V. 127

PHILLIPSASTR/EA, D'Orbignv.
Synon., Smithia, Milne-Edwards.

Compound astraeiform polyparia, with confluent calyces, destitute
of intervening walls, but enveloped at the base of the colony by a
common epithecal crust. Calyces horizontally expanded in their
margins, excavated by an abrupt central pit, which is usually sur-
rounded by an elevated monticulose rim. Radial lamellae linear,
carinated on the sides, and crenulated at the edges by the ends of
the same carinations. Cycle of the lamellae composed of alternately
longer and shorter ones ; the longer lamellae unite in the centre,
and form a pseudo-columellar, nodular protuberance, but do not
connect into a continuous vertical axis. The shorter lamellae ter-
minate on the monticulose rim surrounding the central crateriform
cell pit. Interlamellar interstices filled with transverse vesiculose
plates, arranged in the peripheral area in arched rows crossing
diagonally the direction of the lateral carinas. The transverse septa
of the centre are so much intersected by the centrally converging
vertical lamellae that the contrast in the structure of the outer area
from that of the inner is very much weakened ; the inclosed vesi-
culose interstitial cell spaces of the centre are somewhat coarser
than the peripheral ones, but it is seldom that larger plates, com-
parable with continuous diaphragms, can be noticed. By the
greater conspicuousness of these transverse plates in the centre, the
genus Pachyphyllum is distinguished from Phillipsastr<ea ; there are,
however, so many gradations of transition between the two modi-
fications of the otherwise perfectly identical types, that I consider
their separation artificial and inappropriate.

PHILLIPSASTR.^A VERNEUILLI, Milne-Edwards.

Size of corallites very different in various specimens. Distance
from centre to centre of cell pits from one to one and a half centi-
meter. Diameter of the central pits varying from three to five
millimeters. Number of lamellae in the circumference of a cell from

128 LOWER PENINSULA.

thirty-six to forty. Lamellae linear within the inner cycle, and tent-
shaped on the expanded peripheral portions of the calycinal conflu-
ent disks. Such tent-form is evidently not caused by any divergence
of the two leaves composing the crests, but by the oblique lateral
attachment of the interstitial vesicles to them. The crenulations
of the edges of the lamellae have the form of linear crossbars. The
centre of the calyx bottom is raised into a columellar knot, and in
vertical sections of calcified specimens a central string of greater
density can be observed, but it is not a solid axal column ; in some
specimens no indication of a columella is perceptible.

Grows in large discoid or convex masses, and is found frequently
in the drift deposits of Michigan, associated with fossils of the cor-
niferous limestone.

Plate XXXVIII. — Fig. 2 represents two silicified fragments
found in the drift of Ann Arbor.

PHILLIPSASTR.'EA GIGAS (?) Owen.
PHILLIPSASTR^A GIGAS, Billings.

Large lenticular masses covered by an epitheca on the lower
side ; upper side formed by large confluent star cells perfectly
resembling the smaller form, Pliillipsast¥^]^crnciiilli. The polyp cells
are unequal, owing to the frequent intercalation of young calyces.
The cells are not perfectly confluent with their horizontally ex-
planate margins ; an obscure polygonal defining line indicates the
extent of every individual calyx, but an intermediate wall is not
developed. Diameter of the larger calyces over two centimeters ;
diameter of inner cell pit not quite one centimeter. The cir-
cumference of the inner cell pit is raised into a rounded monticulose
rim. Bottom of inner cell pit reversed into a small central boss, on
which the lamelhe unite with a spiral twist. Circumference of cells
radiated by from fifty to sixty crenulated lamellae.

P'ound in the upper strata of the Island of Mackinac.

Plate XXX VIL, Lower row. — The left-hand figure presents a
surface view of a calcified specimen from Mackinac. This form is
in all particulars, except in the size of the calyces, similar to

PAL^ONTOLOG Y.] I 2 9

Phillipsastrasa VerneuilH, but the two forms arc not found associated
on Mackinac Island. It is doubtful to me whether Owen's species
is identical with this form ; the figures and descriptions given by
him are insufficient to determine the question positively. Another
large form of Phillipsastrsea, for which I propose the name of
PJiillipsastrcca Yandclli, is found in the Helderberg limestones of the
Falls of the Ohio, and in silicified condition, often loose, in the drift
of that vicinity. It differs from the described form in having
much more spacious central cell pits, not surrounded by a raised
rim. The bottom of the cells is formed by a large convex pro-
tuberance on which the lamellae unite ; diameter of cells from three
to four centimeters ; inner cell pit one and a half to two millimeters
wide ; exterior outlines of calyces obscurely defined. Not repre-
sented for want of space.

. STROMBODES, Schweigger.

Compound polyparia, formed of radiated polyp cells united, with-
out defining walls. The cells are either confluent, without any
peripheral demarkation, or they join under obtusely crested poly-
gonal outlines, which inclose shallow calycinal depressions with an
abrupt central pit. The surface impressed with these pits forms a
continuous laminar expansion, and the growth of the polyparia
consists in a constantly repeated production of such laminae ; where-
fore we find them formed of a superimposed series of such layers.
The walls of the abrupt central depressions of the 'calyces, which
correspond in the layers, combine by invagination into cylindrical
central cores, extending, without interruption, through the whole
length of the corallum ; the crest-like plications in the circum-
ference of the inner cell pits form a cycle of vertical lamellae, which
intersect this central core. The horizontally spreading marginal
portions of the superimposed calyces are not in immediate con-
tiguity ; between each layer an interstice exists, which is filled
with unequally interlaced, blister-like vesicles. This indicates a
periodicity in the growth of the polyparia by which at one time
fully finished, radially plicated, continuous laminar calyces were
formed, and in time for the abandonment of the old cells and prc-

9

130 LOWER PENINSULA.

paratory to the formation of a new layer, the old surface was
covered by a coating of vesicles to serve as an under structure for
the support of the new, carefully finished, calycinal flloor. The
radial plications of the calyces generally unite in the centre into a
papillose projection ; in rare cases they die out before reaching the
centre and leave a small naked spot within. The arrangement of
the lamellae into four fascicles and the development of a small
septal fovea are not unfrequently noticeable in the bottom of the
cells ; the steeply ascending sides of the inner pit arc surrounded
by crest-like plications, which grow stouter as they bend over upon
the expanded marginal parts, and, in their course to the margin,
repeatedly divide into narrow rounded ruga?, often five or six
times more numerous than the crests of the cell pit from which they
emanate. The division in this case is not conformable with the
rule of intercalation of new lamellae set forth in the introductory
pages, but takes place apparently without any strict order. The
plications of this expanded peripheral area are mere superficial
rugae, and do not combine into vertical lamellae. In several species
on each side of a radial ruga of the expanded calycinal surface, a
row of punctiform, closely approximated pores opens, which are in
alternating position on the two sides ; in perfectly intact surfaces
these pores seem to be closed ; it is onl)- in slightly worn speci-
mens that they are open circular orifices.

STROMBODES PENTAGONUS, Goldfuss.
Strombodes striatus, D'Orbigny,

Large discoid expansions covered on the lower side with a con-
centrically wrinkled epitheca, and attached at the central apex.
Surface of disks composed of irregularly polygonal, shallow calyces
with an abrupt central depression. Diameter of the calyces very
variable in different specimens, ranging from one to four centi-
meters. The steep walls of the inner cell pit are surrounded by
about thirty stout, crest-like plications, which, reduced to a smaller
number by coalescence, unite in the centre, and form there a styli-
form protuberance ; or the bottom of the cell remains even while

PALEONTOLOGY.

131

crossed by the carinae. On the expanded marginal portion of the
calyces the plications lose their crest form and arc reduced to
rounded rugae, which, through division or through the implantation
of new ones between them, multiply to three or four times their
original number, and have then the form of equal, narrow, linear
stripes. On both sides of each of these stripes a row of circular
pores opens with closely crowded orifices alternating in position
on the opposite sides. In some specimens the inner cell pits are
surrounded by a monticulose raised rim ; in others the surface of
the calyces is roughened by blisters without a distinct radial stria-
tion ; these conditions represent the different stages in the growth
of the coral which it undergoes previous to the deposition of a new
well-finished calycinal floor. The great difference in the size of
the calyces of some specimens has induced D'Orbigny to dis-
tinguish the larger-celled form, as Stronibodcs striatiis, from the
smaller-celled Stronibodcs pciitagoniis of Goldfuss, but it is impossible
to draw a dividing line between them ; all gradations of sizes, from
the large to the small forms, can be found associated in the
same localities, and in structure not the least difference exists be-
tween them.

Occurs very abundantly in the Niagara group of Point Detour,
Drummond's Island, etc., and frequently found in the drift.

Plate XLVIII. — Fig. i is a silicified specimen corresponding with
Strombodes striatus, D'Orbigny. Fig. 2 represents the typical form
of Goldfuss's species, Strombodes pentagonus.

The Niagara group of Kentucky and Indiana incloses an abun-
dance of specimens, which appear to be in eveiy respect identical
with the above-described species, but I observe that the interstitial
layers of vesicles in the specimens from Michigan are always of
much coarser structure than in the specimens found at Louisville,,
etc.

STROMBODES PYGM^US, N. Sp.

Calyces not defined, composing laminar surfaces dotted with
abrupt cell pits, about two millimeters in width, and distant from
each other six or eight millimeters. The broad interstitial surface
is striate by the diverging radial rugae of the cell cups, which meet

1^2 LOWER PENINSULA.

and intermingle with those of the adjoining cells. The radial
striae are bordered on both sides by a row of circular pores as in
the former species. In the centre of the pits the uniting radial
crests form a small styliform projection.

Found in association with the other species in the Niagara group
of Drummond's Island and of Point Detour.

Plate XLVIII. — Fig. 3, silicified specimen from Point Detour,
Lake Huron.

STROMBODES MAMILLATUS, D. Dale Owen.

Centre of calyces rising from a common interstitial surface as
high, mamiform cones, excavated at the top by a crater-like, ra-
diated pit. The radial rugae extend over the surface of the cones
and across the interstitial surface from one cell into the other,
as narrow, equal-sized bands of granulose surface. In the interstices
between these bands distant depressions can be noticed, but noth-
ing similar to the rows of circular pores bordering the rugae of the
other species. The centre of the cell pits is formed by a small
styliform projection. General structure as in the other species;
composed of alternating layers of well-finished cup membranes,
and of strata of vesicles. The size of the mamiform cones and
their relative distance differ in various specimens. Width of cell
pits from four to five millimeters. Distance from centre to centre
from one to two centimeters. Found in the Niagara group of
Drummond's Island ; it is also common in the same formation in
Iowa, Kentucky, Indiana, etc.

Plate XLVIII. — Fig. 4, silicified specimen form Point Detour.

STROMBODES ALPENENSIS, N. Sp.

Massive horizontal expansions, co\crcd on the lower side by an
epithecal crust. Surface formed of shallow calyces, deepening in
the centre into a more abrupt pit. The calyces are confluent, or
imperfectly defined from each other by tent-shaped, obtuse ridges

PAL.-EONTOLOG Y, I 3 3

circumscribing irregularly polygonal spaces. Radial plications from
thirty to forty, linear, crest-like in the circumference of the inner
pits, and uniting in the centre into a twisted knot or without form-
ing any protuberance. The crest-like plications, while diverging
across the expanded peripheral cup margins, gradually widen into
convex bands, separated by narrow linear furrows ; their surface is
ornamented with densely crowded granulations. The diameter of
the calyces is very unequal in the same specimens ; some of them
are three centimeters wide, others only one. The internal struc-
ture of the specimens I could never distinctly observe ; all the
specimens are transformed into a solid white amorphous mass of
carbonate of lime, resembling ivory or porcelain in a fracture,
while other corals associated with them had their most delicate
details of structure perfectly preserved, excepting one other here-
tofore described (Chonophyllum ponderosum), which is found in
similarly solidified condition.

It is found in the light-colored limestones of the Hamilton
group, forming the lowest beds in the quarries of Phelps' lime-
kilns, near Alpena, and in a similar rock near Broadwell's mills, on
Thunder Bay River.

Plate XXXVIII. — Fig. i is a calcified specimen from Broadwell's
mills, in natural size.

In the Hamilton group of Rockford, Iowa, a coral is found
which bears an almost perfect similarity to the form just described,
exhibiting a well-preserved structure, consisting of membraniform
layers of confluent radiated cell cups, interlaminated with strata of
coarse, blister-like vesicles, entirely conformable witli the structure
of a Strombodes from the Niagara group. The lamellae unite in
the depressed central pits in a low obtuse boss. Mr. Hall has
described this coral under the name of Smithia Johnnai, and
another similarly built form as Smithia multiradiata, but they
differ altogether in structure from the genus Smithia, or, what
I consider as the same thing, from Phillipsastrasa. The latter
genus has the structure of the usual forms of the compound
Cyathophylla, differing from them only by the absence of walls
separating the single cell cups, while the specimens under consider-
ation are built according to the plan of Strombodes ; and, guided
by perfect external similarity, I also identify the structureless
specimens found in Michigan, with Strombodes.

134 LOWER PENINSULA.

VESICULARIA, N. Genus.

Compound polyparia formed of a superimposed series of calycinal
cups, of coarsely blistered surface, which in vertical sections appear
as a uniform succession of layers of large, unequal, vesiculose
plates, perfectly resembling a vertical section through a Cysti-
phyllum. These blistered calycinal membranous layers are radiated
by plications, which are linear low crests in the circumference of
an inner, broad, shallow cell pit, the bottom of which is occupied by
a flat diaphragm, over which the crests converge toward the centre,
gradually vanishing. The margins of the cells are broad, expanded,
and confluent with each other, without demarkation. The radial
plications lose, in their divergence across them, the crested form,
and expand into flattened, gradually widening bands, as in Chono-
phyllum.

The crest-like portion of the plications in the circumference of
the inner cell pit forms, by combination with the invaginated series
of cups, a narrow cycle of vertical crests surrounding an inner core
formed of diaphragms. In the outer area no trace of continuous
vertical leaves is noticeable. Vesicularia is closely related with
Strombodes ; it differs from it in its broad calycinal bottoms having
the shape of diaphragms, and in a prevailing disposition of all the
calycinal layers to a vesiculose blistered structure, which in the
other genus is only periodically so, and alternates with homogene-
ously formed laminar layers of more highly finished surface. From
Chonophyllum it is likewise distinguished by the vesiculose struc-
ture of the superimposed cup walls ; from Cystiphyllum it only
differs in having a compound mode of growth with confluent cells.

VESICULARIA MAJOR, N. Sr.

Discoid expansions formed of large confluent polyp cells. Calyces
shallow,'explanate, with a broad, dish-shaped central pit, the bot-
tom of which is formed by a flat diaphragm. Radial plications

PALAEONTOLOGY.

135

linear, crest-shaped in the circumference of the inner pit, and ex-
tending over the surface of the diaphragms, gradually vanishing
near the centre. In their divergence across the expanded margi-
nal parts, the plications lose the crest form and dilate into low,
rounded, gradually widening rugae with intermediate linear fur-
rows. The surface of the expanded parts of the calyces is raised
into blisters, locally densely crowded, and obscuring the radial folds ;
in other parts singly dispersed. The central diaphragms are sim-
ple and not blistered. In vertical sections the polyparia fully re-
semble a Cystiphyllum, being composed of layers of coarse, un-
equal, interlaced vesicles. The calyces attain in some specimens a
diameter of from three to four inches. Found in the Niagara
group, at Point Detour, and on Drummond's Island.

Plate XLIX., right-hand figure, upper row. — In the Niagara
group of Masonville, Iowa, another species of more minutely vesic-
ulose structure occurs, which I have named Vesiailaria minor, and
represented, for sake of comparison, on the same plate with the
other. The plications are very delicate, ornamented with spinulose
projections ; the cell pits, scarcely depressed, are only perceptible
by the convergence of the plications toward certain centres. Un-
der side of the expansions covered by a concentrically wrinkled
epitheca, with radiciform excrescences for attachment to foreign
bodies. Associated with these compound specimens are single
polyp cells of the same vesiculose structure, which connect the
compound forms so closely with Cystiphyllum, that it would have
been more appropriate, perhaps, instead of establishing a new sub-
genus Vesiciilaria, to change Milne-Edwards' original definition of
Cystiphyllum so as to include the compound forms with con-
fluent cell cups.

VESICULARIA VARIOLOSA, N. Sp.

Confluent calyces forming mamiform monticules, truncate by
abrupt but shallow cell pits, the bottoms of which are formed by
flat diaphragms with marginal depressions indicating the principal
septal fascicles. Distance from centre to centre of the monticuloise
calyces about two centimeters ; diameter of terminal cell pits about
five millimeters. Calyces surrounded by about thirty plications,

136 LOWER PENINSULA.

having the form of low crests in the inner circumference of the pits,
but of rounded rugose form in their extension across the interstices,
and on the sloping sides of the monticules. The surface of the
polyparia is generally raised into irregular large blisters, which
impair the distinctness and continuity of the radial plications. In
vertical sections layers of interlaced coarse vesicles are found to
constitute the whole polyparium.

Occurs in the Niagara group of Point Detour, and also in Iowa
localities. This form is easily mistaken for Strombodes mamillatus,
Owen, which occurs in its association. The well-developed flat
diaphragms and entirely vesiculosa structure distinguish it, how-
ever, from the latter.

Plate XLIX. — P'ig. 4 represents a surface view of a silicified spec-
imen from Point Detour.

CYSTIPHYLLUM, Milne-Edwards.

Simple or loosely aggregated polyp cells, of conical or cylindrical
form, enveloped by an epithecal wall, composed of an invaginated
series of cell cups of compound vesiculose structure, and radi-
ated by plications. The plications are either crest-like within the
ascending part of the calyces, and dilating into flattened broader
rugae toward the peripheral margins, or are represented merely by
superficial linear striae or rows of spinules ; they often become totally
obsolete, and the surface of the calyces appears simply blistered,
without any visible radiation ; in no case do the plications com-
bine into vertical laminae pervading the whole length of the coral-
lum. The arrangement of the plications into four principal fas-
cicles is in some of the specimens very distinct. The inner area
of the polyp cells is rarely intersected by transverse diaphragms ;
generally the central vesicles are somewhat coarser than the
peripheral ones, but without demarkation between the bottom part
of the calyces and the sides as in Cyathophyllum. The exterior
epithecal wall is in many specimens longitudinally ribbed by well-
pronounced septal striae, while the vesiculose internal surface of
the calyces may exhibit but very indistinct radial plications.

PAL.^EONTOLOG 1 '. I 3 7

CYSTIPHYLLUM NIAGARENSE.

CONOPHYLLUM NIAGARENSE, Hall.

~ Conical polyp cells attached to other bodies at the base, and by
additional root-like prolongations from the sides. Stems elongated,
subcylindrical, or shorter turbinate, annulated by superficial con-
strictions with tortuous flexions, or by periodical total interruptions
in the growth of a calyx, and the formation of a new cell from
within. The calyces are moderately deep, uniformly spreading
from an obtusely angustated bottom ; margins erect : their surface
is blistered, and is radially striate by spinulose crests, developed in
some specimens with more distinctness than in others. The sur-
face of the polyp stems in well-preserved condition is longitudinally
ribbed by septal stria;, but it often happens that the outer walls
are destroyed, and that the stems are of rough exfoliated aspect,
exhibiting the concave side of the blisters composing the cell cups,
and the free edges of the single invaginated cups composing the
stems.

Found in the Niagara group of Drummond's Island, at Point
Detour ; likewise in the Niagara group of Kentucky, Iowa, and
Indiana.

Plate XLIX. — Fig. 3 represents several silicified specimens of
shorter turbinate and of more elongate tortuous form. The upper
right-hand and the lower left-hand specimens are found at Drum-
mond's Island ; the other two at Masonville, Iowa.

CYSTIPHYLLUM AMERICANUM, Milne-Edwards.

Single polyparia, surrounded by a perfect, concentrically wrinkled
epithecal wall, of conical, or, in the progress of growth, of horn-
shaped, curved, or straight cylindrical form. Dimensions of stems
very variable, from one to two inches in diameter, and in specimens
of cylindrical growth not unfrequently over one foot in length ;
other specimens have a much shorter turbinate form. Calyces
moderately deep, with explanate margins, equally tapering toward
the bottom, which is generally occupied by a few irregular blis-

138

LOWER PENINSULA.

ters. The ascending calyx walls are sometimes only slightly blis-
tered, and folded into stout radial rug^. In other specimens the
rugse are obsolete and the blisters principally obvious. A great
many variations in mode of growth, in the relative size of the
vesicles, and in distinctness of plications, can be observed among
the numerous specimens found in the Helderberg group and in
the Hamilton strata, which, upon closer investigation, may require
to be separated into different species, but for the present I have
not discovered any well-established characters upon which such a
division could be based.

It occurs nearly in every stratum of the upper Helderberg group
and of the Hamilton group in Michigan, Canada, New York, and
in the Western States.

Plate L., Upper row. — The outer left-hand specimen is from the
Hamilton group near Broadwell's mills, on Thunder Bay River ;
the two other specimens are from the Hamilton group of Widder,
C. W. The right-hand figure in the lower row represents silicified
specimens from the corniferous limestone found in the drift.

CYSTIPHYLLUM AGGREGATUM, Billings.

Conico-cylindrical polyparia, closely aggregated, and attached
to each other by the wrinkles of their surface, multiplying by
calycinal gemmation. Diameter of stems from two to three centi-
meters. Structure conformable with Cystiphyllum ; vesicles coarse ;
end cups moderately excavated, blistered, with faint, spinulose,
radiating striae. Epithecal walls likewise faintly ribbed by septal
rugae. Found in large clusters in the Hamilton group of Thunder
Bay. Not figured.

CYSTIPHYLLUM SULCATUM, Billings.

•Symmetrically curved, conical polyparia with a pointed apex.
Surface gently annulated by obtuse wrinkles of growth. Calyces
spacious, oblique to the axis, with erect acute margins. The sur-
face of the calyces generally forms a continuous laminar bag with-
out a blistered surface ; the marginal part of the cups is radiated
by rounded ruga.% broadest near the edges of the cups, narrowing

PAL^ONTOLOG Y.

139

and almost vanishing near the bottom. The arrangement of the
plications into four fascicles with intermediate gaps is in this
species particularly plain, and the apertural gap situated in the
centre of the large curvature of the horn-shaped cells is the largest.
In vertical sections the structure is found to be perfectly con-
formable with Cystiphyllum, composed of incased vesiculose cups.
There are two varieties : in one the plications expand toward the
margin of the cups into broad bands decorated with granulations ;
in the other form the plicae split toward the margin into narrower
fine striae. The latter variety, which has also less obliquely erect
cups, is found in the upper Helderberg limestones of the Falls of
the Ohio ; the other is found in the drift of Ann Arbor, on Mackinac
Island, and in the corniferous limestone of Port Colborne, in
Canada,

Plate L., Lower row. — The |^left-hand figure represents silicified
specimens from Port Colborne. Various other forms of the genus
Cystiphyllum occur at the Falls of the Ohio, and at Columbus,
Ohio, which I omit to describe, as not found in Michigan.

ZAPHRENTIS, Rafinesque.

Inclusive of Streptelasma, Hall, as a sub-generic fonn.

Simple conical polyparia, composed of a series of invaginated,
radially plicated cell cups. The superimposed cell cups are with
their side walls so intimately united, that no interstice is left be-
tween them, and all combine into one simple compact wall folded
into laminar plications. The interstices between the plications
are, within the terminal cups, free and open throughout. The
plications of all the incased cups are connected into continuous,
strong vertical leaves intersecting the whole length of the corallum.
The bottom part of each cup remains free, and is separated from
the subjacent one by a small interstice. It appears in vertical sec-
tions through the corallum as a transverse laminar diaphragm.
These superimposed diaphragms extend from wall to wall ; their
peripheral margins are deflected and connect with the outer wall at
an acute, downwardly directed angle. The interlamellar interstices,
which are open in the end cell, become, below its bottom, in-

140 LOWER PENINSULA.

tersected by the diaphragms, and are divided into coarse cellulose
chambers, which must not be confused with the smaller interstitial
cell spaces of the outer area in a Cyathophyllum. The latter are
formed by rows of small vesiculose plates traversing the inter-
stices in arches, ascending from the inner circumference of the dia-
phragms to the outer walls of the polyparium, within the end cup
as well as below it. The transverse interstitial plates which make
part of the diaphragms invariably approach the outer walls in a
downwardly instead of an upwardly directed curve. The arrange-
ment of the lamellae into four fascicles is, in Zaphrentis, generally
well marked, and a largely developed septal fovea in the interstice
between the two apertural fascicles is considered as the leading dis-
tinctive character of the genus Zaphrentis.

The importance of the development of a septal fovea in Cyatho-
phylloid corals has been unreasonably overestimated by Milne-
Edwards. In his work on palaeozoic corals, he describes twenty-
nine species of Zaphrentis, simply guided by the presence of a large
septal fovea, in disregard of other structural peculiarities. Fully
half of these forms, named Zaphrentis, have not the structure of
Zaphrentis, and belong to the true Cyathophylla, by reason of the
development of transverse vesiculose plates in the interlamellar
interstices of the end cups, which, as has been stated before, never
occur in the interstices of the lamellae of a Zaphrentis. As ex-
amples of Cyathophylla, so misplaced, I mention Zaphrentis
cornicula, Zaphr. Guerangeri, Zaphr. excavata, Zaphr. Michelini,
etc. The genus Streptelasvia, of Hall, and his Polydilasma, which
1 consider as the same thing, differ from Zaphrentis- merely in hav-
ing a less conspicuous, or, sometimes, almost obsolete develop-
ment of a septal fovea, and in the irregular entanglement of its
radial lamellae in the centre, constituting, in combination with the
intersected diaphragms, a spongioso-cellulose pseudo-columella ; or,
at least, the regularity of the diaphragms in the centre is obscured
by their multiple labyrinthical intersection with the vertical leaves.
A strict distinction of the two genera is not possible ; some forms
of this group could with the same propriety be placed in one as
in the other.

The Cyathophylloid corals of the lower Silurian strata generally
have the structure of Streptelasma, and, considering Streptelasma

PAL^ONTOLOG V.

141

as a subgenus of Zaphrentis, I begin with the description of its
species first as being the oldest ones of the type, and let those of
Zaphrentis follow them.

STREPTELASMA CORNICULUM, Hall.

The original specimens represented and described by Hall, from
the Trenton strata of New York, are too imperfect to allow much
more than recognition of the general structure. Similar and no
better preserved specimens are found in the Trenton strata of
Escanaba River, and on St. Joseph's Island and Sulphur Island,
situated north of the other. I have represented them on Plate LI.,
the four left-hand figures in the upper row ; the upper larger
specimen is from the lower Trenton strata of Escanaba ; the three
lower specimens are from somewhat higher beds on Sulphur Island.

It is doubtful whether the specimens described under the same
name by Milne-Edwards, from the Hudson River group, belong to
the same species ; they are found in much better preservation,
and can therefore be more specifically described. Elongate conical,
symmetrically curved, horn-shaped corals ; middle-sized specimens
have a diameter of about three centimeters at the calyx margin by
a length of from seven to eight centimeters, but the proportion
between length and width of the specimens differs ; some are more
elongated, others are shorter than the indicated proportions. The
surface of the polyparia is covered by a perfect epithecal crust,
with transverse fine wrinkles of growth, and longitudinally striate
by septal rugse and intermediate furrows. Milne-Edwards asserts
the cells to be covered by an imperfectly developed epithecal crust,
but this is an error. Calyces moderately deep, with erect acute
margins, steeply inclined side walls, and a variably formed bottom,
sometimes narrowed into a blunt end ; at other times broader,
rounded, convex in the middle. Lamellae linear, stout, alternately
larger and smaller, from 120 to 130 in the circumference of calyces,
three centimeters wide. Their surface is decorated by minute
granulose rugae, crossing the side faces in an ascending direction
from the inside toward the periphery. The radial crests become
labyrinthically entangled in the centre of the cells, and usually form
a broad convex protuberance. A small septal fovea is always

142 LOWER PENINSULA.

noticeable, and sometimes also the lateral septal gaps are well
marked. In vertical sections the centre of the polyparia is found
to be intersected by well-developed transverse diaphragms ; the
vertical crests intersecting them divide the interstices between
them into irregular cell spaces. The apices of the polyparia are
pointed, and rarely exhibit a small scar of attachment. Sometimes
twin cells are found, but this is abnormal.

Plate LI., Upper row. — The largest specimen is from the Hudson
River group of Drummond's Island ; the other six smaller speci-
mens were found at Richmond, Indiana, and at Madison. The
right-hand calyces have broad convex cup bottoms with irregularly
entangled lamellae ; the two upper figures to the left of the larger
have a well-developed septal fovea, and a narrow, styliform, central
protuberance. The lower left-hand specimen is a twin-cell.

STREPTELASMA PATULA, N. Sp.

POLYDILASMA, Hall.

Short conical polyparia, about two centimeters wide at the ex-
panded calyx margins, by a length of only one or one and a half
centimeter. Calyx variable in depth in accordance with the more
elongate or shortened external form of the polyp cells, surrounded
by from twenty-five to thirty stout lamellar crests, with as many
smaller intermediate ones, confined only to the marginal portions
of the calyces. The sides of the lamellae are transversely striate,
and their edges crenulated. By the convergence of the lamellae
in the centre, a narrow columellar axis of spongiose structure is
formed, which on one side is deeply exsinuated by a septal fovea ;
in very young specimens this axis is a horseshoe-formed erect leaf,
against the circumference of which the converging lamella; abut ;
the centre of the horseshoe sinus is occupied by a strong lamella.

Found in the Niagara group of Drummond's Island and Point
Detour; also in the Niagara limestones of Iowa, at Masonvillc.

Plate XXXIX. — Fig. i represents a number of silicificd speci-
mens found at Drummond's Island.

PAL^EONTOLOG V. 1 43

STREPTELASMA CONULUS, N. Sp.

Straight, conical, small-sized polyparia ; the larger ones attain a
diameter of one centimeter by one and a half in length ; surface
faintly annulated by lines of growth, not ribbed longitudinally as
in the similar form Streptelasma calycula. Calyces deep, with erect
margins surrounded by from twenty to twenty-five denticulated
lamellar crests of larger size, and by as many intermediate rudi-
mentary ones with likewise dentate edges ; the sides of the lamellae
are ornamented with transverse rugae. The larger lamellae unite
in the centre, as in the former species, into a horseshoe-formed
cycle which incloses a narrow core of lacunose, irregularly anasto-
mosing cell spaces ; the aperture of the horseshoe corresponds
with the principal septal fovea.

Found associated with the former in the Niagara group of Drum-
mond's Island, etc.

Plate XXXIX. — Fig. 4 represents a number of silicified specimens
from the above-named locality.

STREPTELASMA SPONGAXIS, N. Sp.

POLYDILASMA, Hall.

Small, conical, horn-shaped polyparia, about two centimeters
wide by three in length in middle-sized specimens. Calyces mod-
erately deep, with slanting sides and slightly expanding margins,
surrounded by about thirty stout crests alternating with as many
intermediate smaller ones. Surface of lamellae decorated with gran-
ules and transverse rugae. The lamellae unite in the centre into a
spongiose axal core, resembling the tissue of a macerated porous
bone. Septal fovea obscure. The apices of the cells exhibit
generally a strong sublateral scar of attachment.

Found associated with the other forms in the Niagara group of
Drummond's Island, and at Point Detour ; also found at Mason-
ville, Iowa.

Plate XXXIX., Fig. 2. — All the smaller specimens represent the
usual form as it occurs at Point Detour. The larger specimen is
from the Niagara group of Paul's Station, Indiana ; it does not

144

LOWER PENINSULA.

seem to differ much from the smaller ^specimens except by a cen-
tral compressed cristiform projection similar to the columella of
Cyathaxonia, which is broken in the represented specimen, but is
distinctly developed in other specimens found there and at Louis-
ville. I hesitate ^therefore to identify the larger specimen with
the smaller form. The subsequently described species have all a
well-developed septal fovea, and are considered to represent the
genus Zaphrnitis proper.

ZAPHRENTIS STOCKESII, Milne-Edwards.

Symmetrically curved conical polyparia, sometimes elliptical in
outlines by a compression in a direction transverse to the curva-
ture. Length of cones about twice the diameter of the calyces,
which in middle-sized specimens is about four centimeters. Ca-
lyces moderately deep, wath erect margins and a spacious subcon-
vex bottom, on which the lamellae unite in an irregularly twisted,
interlacing manner as low carinae. Lamellae linear, stout ; sixty
to sixty-five larger ones alternating with as many small rudimentary
crests may be counted in the circumference of calyces four centi-
meters wide. A large septal fovea is situated in the median line
of the convex side of the curved polyparia. Transverse diaphragms
well developed ; the crests on the upper side do not connect into
continuous vertical leaves with those of the succumbent cups ;
the lower side of the diaphragms is generally smooth, not crested.
The external walls of the specimens are rarely preserved in the
silicified condition, and the excoriated surface is longitudinally
ribbed by the exposed vertical plications. In some specimens,
however, the superficial epithecal crust is perfectly preserved.
Found in the Niagara group of Drummond's Island, Point Detour,
and in the same formation at Masonville, Iowa.

Plate LI., Lower row — The two largest specimens. The upper
one, on the left-hand side, is a side view of an excoriated specimen
from Point Detour. The one on the right-hand side of the plate
exhibits the bottom of a calyx and the position of the septal
fovea ; the erect marginal parts are broken off. The second figure
from the left, in the lower row, is also a young specimen of this
kind.

PALAZONTOLOG Y. 145

ZAPHRENTIS UMBONATA, N. Sp.

Conical, horn-shaped polyparia resembh'ng Zaphr. Stockesii, at-
taining in some larger specimens a calyx diameter of eight centi-
meters by twice that in length ; the usual size of the specimens
found is smaller. Calyces spacious, with erect acute margins and
abroad bottom, which is reversed into a large, laterally compressed,
prominent cone. The circumference of the larger calyces is sur-
rounded by about eighty large lamellae, with as many intermediate
smaller ones ; the larger ones unite on the central cone, ascending
its sides directly or with a spiral twist. A large septal fovea is
developed in the median line of the larger curved side. In vertical
sections the invaginated, reversed, conical cell bottoms are observed
to have grown together with their apices and to form a cellulose,
pscudo-columella. Found associated with Zaphr. Stockesii in the
Niagara group of Point Detour and Drummond's Island. Casts
of a similar species are common in the Niagara limestones of
Milwaukee. At Louisville, also, this coral occurs.

Plate LI., Lower row. — The upper figure in the centre is one of
the smaller-sized specimens found on Drummond's Island ; another
small specimen is represented in the lower right-hand corner of the
plate. The central cone is in some specimens much more prom-
inent than in those given here. In the lower row of the same
plate the first outer specimen on the left-hand side and the third
one represent other calyces of a Zaphrentis, conformable in some
respects with the heretofore described associated forms, but differ-
ing in the shape of the cell bottom, which in one is formed by a
large rounded protuberance, exsinuated on one side by a septal
fovea, while in the other, evidently only an individual modification
of the former, it is a horseshoe-formed elevated ring with a deeply
depressed, smooth, central excavation. This form seems to con-
stitute a different species from the others, but I leave the question
open for further decision.

ZAPHRENTIS GIGANTEA, Lesueur.

Conico-cylindrical, horn-shaped polyparia, attaining in some speci-
mens a size of two and a half feet in length, by a diameter of three
10

146 LOWER PENINSULA.

inches. Some enlarge their diameter rapidly to a certain thickness,
and then grow on in a uniformly cylindrical shape ; others are in
the young state, slender, flexuose, and irregularly constricted stems,
and grow gradually to larger diameters. The surface of the poly-
paria is covered by an epitheca with shallow annular wrinkles of
growth and longitudinally ribbed by septal strije, which, however,
are not in all specimens equally distinct. Calyces spacious, with
erect walls, and acute, wedge-like margins ; bottom broad, marginally
depressed and flat in the centre. In one place of the circumference
the diaphragms are more deeply depressed by a septal fovea.
Radial lamellae stout, linear, alternately long and short, but ap-
pearing nearly equal on the margins of the calyces, where the sharp
crested leaves of the inside expand into low rounded rugae. The
extension of the radial crests toward the centre is subject to varia-
tions ; in some the central part of the diaphragms remains smooth,
and the crests are confined to their peripheral circumference ;
in others the crests reach as low carinas to the centre and 'become
irregularly entangled in their convergence, but these central por-
tions of the crests are merely superficial, and do not intersect the
diaphragms to form continuous vertical leaves. The number of
lamelltC in calyces of about two and a half inches diameter is
150 to 160, half of which are of the smaller size. Found in the
upper Helderberg limestones of Michigan, Canada, Ohio, and in
the Western States.

Plate LII. represents specimens of smaller size, found at the
Falls of the Ohio.

ZAPHRENTIS PROLIFICA, Billings.

Conical, irregularly curved polyp cells, obtusely wrinkled by annu-
lar rugce. Middle-sized specimens about three or four centimeters
wide at the calyx margin, by a length of from seven to eight centi-
meters. Calyces deep, spacious, with erect margins. Bottom, of
cells variable ; most frequently its centre is reversed into a laterally
compressed, more or less prominent cristiform projection, whose
sides are carinated by the centrally uniting radial crests ; in others
the bottom is uniformly depressed convex, covered by the en-
tangled converging ends of the lamella; ; sometimes also a flat
smooth spot is left in the centre of the cell bottom, which merges

PAL^ONTOLOG Y. 1 4 -

into a large septal fovea. The septal fovea is, in its position, in-
dependent from the curvature of the polyp cells, but always repre-
sents the apertural fovea, whether it be in the median line of the
curved cells or in lateral position. Lamellte about 120 in the cir-
cumference of calyces three or four centimeters wide, alternately
large and small. Near the calyx margin the plications have the
form of low rounded rugcC with granulose surface ; further inside
of the calyces the rugse transform into acute, stout, linear crests.
In vertical sections the superimposed bottoms of the incased cell
cups appear as large transverse diaphragms joining the outer walls
with deeply deflected margins. Occurs frequently in the upper
Helderberg limestones of Michigan, and in the neighboring States
to the east and west ; is also common in the drift boulders bclontr-
ing -to the corniferous limestone formation.

Plate LIII. — The upper row represents various silicified speci-
mens, partly found in the drift of Ann Arbor, partly from the corni-
ferous limestone of Port Colborne, C. W.

ZAPHRENTIS NODULOSA, N. Sp.

Curved elongato-conical polyparia of somewhat flexuose growth,
annulated by shallow constrictions and finer transverse wrinkles ;
vertically striate by septal furrows. The apicical portion of the
polyp cells is decorated by densely crowded, stout, spinulose projec-
tions, which gradually vanish on the upper parts of the cells.
Calyces deep, with erect margins ; bottom formed by a narrow,
almost smooth diaphragm deflected on one side into a large septal
fovea. The lamellae are sharp linear crests within the calyx ; near
the margins they become low rounded rugae ; about seventy in the
circumference of calyces one inch in diameter, alternately of larger
and smaller size. The sides of the lamellce are decorated by
irregular transverse rugge and granulations.

Not uncommon in the drift of Michigan, in association with
corniferous limestone fossils ; also found in the corniferous strata
of Canada.

Plate LV. — The right-hand side small specimen, in the lower
row, represents a rather small calyx found in the drift of Ann
Arbor ; other larger specimens dilate more rapidly, and resemble
in mode of growth Zaphr. prolifica.

148 LOWER PENINSULA.

ZAPHRENTIS GREGARIA, N. Sp.

Short turbinate, somewhat curved polyp cells, of about two inches
calyx diameter by a length of from one and a half to two and a
half inches. Surface annulated by sharp transverse wrinkles and
distinctly ribbed by longitudinal septal furrows. Calyces spacious,
with broad subplane bottoms, over which the lamellce extend to the
centres. A large septal fovea generally on the convex curved side.
Side walls of calyces suberect with acute edges. Found in large
numbers in the black shaly limestone strata of the lower part of
the Hamilton group, on the shore of Lake Huron, north of Thunder
Bay. Not represented.

Another form of Zaphrentis found in the Hamilton group of
Arcona, C. W., may be mentioned here. Some of the specimens
perfectly resemble Zaphrentis prolifica of the Helderberg group ;
other larger specimens, externally identical with them, have the
bottoms of the calyces formed by broad, perfectly naked, flat, or
somewhat concave diaphragms. They seem to be mere individual
variations of one and the same type^ first represented under the
form of Zaphr. prolifica.

ZAPHRENTIS CONIGERA, N. Sp.

Compare AULOPHYLLUM, Milne-Edwards.

Long, horn-shaped, conico-cylindrical polyparia, with obtusely
annulated rugose surface, attaining a size of one foot in length by a
diameter of one and a half inch. Calyx deep, with erect side
walls and acute margins, surrounded by about 120 alternately larger
and smaller lamellce ; sharp linear crests in the inside of the calyces,
lowered into rounded rugce on the margins. The bottom of the
calyces is reflected and forms a large pointed cone with broad base,
on which the central ends of the radial crests ascend with a spiral
twist. Septal fovea comparatively small, irregular in position re-
garding the curvature of the horn-shaped stems. The central cones
are the analogon of the transverse diaphragms, which are invagi-
nated into one another, and become superficially attached by
their crests, but do not combine into a continuous axal column.
From an observation of the figures of Clisioph. prolapsum.

PAL.^EONTOLOG Y.

149

McCoy, called Aulophyllum by Milne-Edwards, I would suggest
that a great similarity exists between them and the species under
consideration ; but Milne-Edwards asserts the development of an
internal wall separating the inner area from the outer, of which in
our specimens not the least trace can be observed. Found in the
upper Helderberg limestones of Mackinac Island, and at the Falls
of the Ohio.

Plate XL., Lower row. — The central, shorter, conical specimen
is from Mackinac Island. The other specimens are from the Falls
of the Ohio. The latter are silicified ; the first is in calcified
condition.

ZAPHRENTIS EXIGUA.
Synon., Heliophyllum exiguum, Billings.

Small, conical, oblique polyp cells, encircled by linear constrictions
and intermediate broader rugae. The curved conules are flattened
on the longer side and quite convex on the shorter side of the
curvature. Diameter of calyces one and a half centimeter in
medium-sized specimens, two and a half in the largest ones ; their
length is about equal to their width, or a little longer. Calyces
moderately deep, surrounded by about seventy alternately large
and small lamellae, denticulated at the edges and transversely
carinated on the sides by granulose ridges. The lamellae are very
stout, protruding with the convexity of their edges above the
margin of the outer peripheral walls of the cells. In the median
line of the flattened longer side of the cells a conspicuous septal
gap is developed, which extends to the centre, dilating into a small
horseshoe-formed sinus around which the lamellae are grouped. The
centre of the septal gap is occupied by a single lamella, which
directly connects with another coming from the opposite side.
The lamellse on both sides of the septal gap unite at their central
ends in semi-pennate fascicles.

The interlamellar interstices are all free and open, whereby this
form proves itself positively distinct from Cyathophyllum or
Heliophyllum, under wiiich name it has been described by Billings.

Occurs in the upper Helderberg limestones of Mackinac, and in
the drift, associated with corniferous limestone fossils ; it is also

150 LOWER PENINSULA.

found in rare cases in the Hamilton group, at Broadwell's mills, on
Thunder Bay River, while in the corniferous limestone of Canada,
and at the Falls of the Ohio, it is quite common.

Plate LI 1 1., Lower row. — The six specimens in two vertical rows
on the left side of the plate, and the lower one in the central
row. The middle specimen in the second row is a calcified speci-
men from Mackinac ; the next specimen below and the one in the
central row are specimens from Crab Orchard, Kentucky. Of the
remainder of the group, the two large specimens are found in the
drift of Ann Arbor; the two smaller ones are from the Falls of
the Ohio.

ZAPHRENTIS UNGULA, N. Sp.

Conical, transversely compressed, and, in the direction of the
^-^mpression, curved polyp cells, more flattened on the convex
side of the curvature than on the opposite. Surface annulated by
linear constrictions, with intermediate, broad, rounded rugae ; apex
of polyparia pointed. Calyces moderately deep, gently expanded
near the margins, gradually narrowing into an obtuse, transverse,
central pit, which is joined by a septal fovea, situated in the me-
dian line of the flattened broader side. Lamellae stout, subequal
near the margins, but alternately long and short ; the longer ones
extend nearly to the centre ; the bottom of the small central pit is
usually free of crests. Dimensions of polyparia from two to three
centimeters in transverse calyx diameter by a little more than half
that measure in the opposite direction, and in length exceeding the
greater width by about one fourth. Number of lamellae in medium-
sized specimens, about 90 ; in larger ones, 100. I'ound in the upper
Helderberg group, at the Falls of the Ohio, and rarely in the
drift of Michigan in silicified condition.

Plate LIII., Lower row. — The two right-hand specimens; the
lower one is about the largest size found.

't>^

ZAPIIRENTLS COMPRESSA, N. Sp.

Conical compressed polyp cells, straight, or cur\ed in the direc-
tion of the narrow side. Large specimens have a calyx diameter
of about eight centimeters in one direction, and four in the other,

PALAZONTOLOG Y. I 5 I

by a length of one decimeter. Calyces of that size are surrounded
by 170 or 180 alternately small and large lamellae, which are, within
the cups, sharp linear crests, but become lower rounded rug^ on
the margins of the cup walls. End cups deep, with erect, acute
margins, of the shape of elongated troughs, gradually diminishing
into a narrow bottom, one side of which is deeply depressed by a
septal fovea situated on the median line of the longer diameter of
the compressed calyces. The degree of compression is not in all
specimens equally strong ; some are very nearly flattened on the
compressed sides, while others have a convex oval circumference.
The surface of the polyparia is annulated by irregular rounded rugae.

Found in the upper Helderberg limestones of the Falls of the
Ohio. It resembles the former species, but is much larger, and is
easily distinguished by the position of its septal fovea, which is on
the narrow side, while that of the previous form is in the centre of
the broader side.

Plate LI 1 1., Lower row. — The upper second figure from the
right-hand side. I consider it desirable to give a figure and descrip-
tion of this form, not found in Michigan up to the present date,
but in all probability to be discovered some day by industrious
collectors.

Various other species of Zaphrentis, partly already known and
described (Zaphrentis Rafinesqut, Milne-Edwards), partly new
forms, are omitted from this report, as not found within the bound-
aries of the State of Michigan.

ZAPHRENTIS SPINULOSA (?) Milne-Edwards.

Symmetrically curved, conical polyp cells, attaining a length of six
centimeters by a calyx diameter of three centimeters. Calyces
deep, with erect margins, surrounded by about forty-five stout
lamellse, and as many rudimentary intermediate folds near the
margins of the calyces. A large septal fovea is developed on the
concave side of the horn-shaped cells, and besides the two lateral sep-
tal gaps, are generally well marked in the specimens. The surface
of the polyp cells is annulated by rings of growth, and the basal
portion is decorated by stout spinules similar to those of Zaphr.
spinulosa, Milne-Edwards. I have not seen any of the Western
specimens with sufficiently well-preserved open calyces to enable

15:

LOWER PENINSULA.

me to establish their exact identification with the Michigan speci-
mens.

Occurs in the carboniferous limestones of Saginaw Bay, on Point
aux Grees, and on Charity Islands ; likewise in the limestones of
Bellevue, Eaton Co.

Plate LV., Lower row. — The upper four central figures and the
larger calyx to the left of them represent specimens found at
Bellevue, Michigan.

AMPLEXUS, SowERBY.

I can not find an appreciable difference between the genera
Amplexus and Zaphrentis ; both have the same general structure.
The radial plications in Amplexus are said to be confined to the
marginal parts of the polyp stems, and not to extend far across the
central area, principally built up of transverse diaphragms. But it is
not uncommon to see, in so-called specimens of Amplexus, the
radial crests extending to the centre of the diaphragms, under the
form of low superficial carina. On the other hand, it is equally
common to notice genuine Zaphrentis forms in which the radial
crests are confined to a peripheral c>'cle, and do not reach to the
centre.

Amplexus generally grows in elongate cylindrical stems, while
Zaphrentis has more of a conical mode of growth, but this is also
a very vague difference ; Zaphrentis frequently grows likewise in
cylindrical stems, and among the associated forms of Zaphrentis
gigantea, Zaphr. Rafinesque, and Amplexus Yandelli, such a simi-
larity in stj^ucture exists that fragments of stems of the three species
are never distinguishable from each other with perfect security
from mistakes. In some forms of Amplexus the septal fovea
becomes obsolete, and in polyp stems where a septal fovea exists
it is not as well marked in one part as in another. The genus
Calophyllum, Dana, has been created to include these forms de-
prived of a septal fov^ea, but I consider such distinction superfluous.

AMPLEXUS SHUMARDI.
Synon., CvATHOi'ii, Siiumardi, Milne-Edwards.
Articulated cylindrical pol)'p stems, composed of a succession of

PAL^ONTOLOG V. 1 5 3

subconical segments, formed by periodical interruptions in i^ the
growth of the calyces, resulting in the closure of the marginal parts
of the old cells by a continuation of the epithecal wall, and a re-
newed growth of a cell, having a narrower basis, from the inner
circumference of the old one, until after a wdiile a new contraction
occurs. The surface of the stems is delicately cancellated by the
intersection of the longitudinal septal rug^e with annular striae of
growth. The basal joint of the stems is of conical growth and ex-
hibits a strong scar for attachment at the apex. The stems are
composed of a cycle of vertical crests projecting from the wall into
the cavity, and of a series of superimposed diaphragms intersecting
the cavity of the stems and extending from wall to wall, joining it
with strongly deflected margins, and only intersected by the vertical
crests in the outer circumference. The end cells, which are gen-
erally only preserved in small young specimens, are of a dilated fun-
nel shape, surrounded by from sixty to seventy alternately large
and small lamellae, with granulose surface and denticulated edges.
The bottom of the calyces is generally formed by a smooth dia-
phragm, but sometimes the crests of the circumference extend over
their surface to the centre as low superficial carinas. The lamellse
lose their linear crested form on the edges of the calyces, where
they expand into low rounded rugse. On one side of the calyx the
diaphragms are deeply depressed by a septal fovea, but the latter
is not in all parts of the stems equally distinct, and becomes not
unfrequently obsolete for a while. The average diameter of the
stems is from two to three centimeters ; the length of the joints
varies from one to two centimeters.

Found in the Niagara group of Point Detour and Drummond's
Island ; at Masonville, Iowa ; in Perry Co., Tennessee, etc.

Plate LIV., Upper row. — The outer figure on the right-hand side
of the plate is a stem from the original locality, from which the
species was first described (Perry Co., Tennessee) ; the three next
fragments to the left of it are from the Niagara group of Drum-
mond's Island ; the other figures on the left are specimens from
Masonville, Iowa. I find it strange that Milne-Edwards should
connect this form with the genus Cyathophyllum, which has the
most characteristic structure of an Amplexus.

154 LOWER PENINSULA.

AMPLEXUS YANDELLI, Milne-Edwards.

Conico-cylindrical flexuose stems, from two to four centimeters
in diameter, annulated by fine wrinkles of growth with intermediate
coarser rugce, and frequently of a jointed structure through peri-
odical constrictions of the calyces and continued growth of the
stem without interruption of the continuity of the epithecal wall.
Calyces deep, with erect margins, surrounded by about sixty alter-
nately large and small vertical crests. The bottom of the calyces is
formed by flat or warped diaphragms, depressed on one side by a
deep septal fovea. The lamellas are restricted to the outer circum-
ference of the diaphragms, but sometimes they extend to the
centre as superficial ridges.

Occurs in the corniferous limestone of Indiana, Kentucky, Canada,
and is found in the drift deposits of Michigan. Some cylindrical
stems, which evidently belong to the juvenile specimens of Za-
phrentis gigantea, are so closely resembling Ampl. Yandelli, that
I always find difficulty in distinguishing them.

Plate LIV., Lower row. — The right-hand specimen is found in
the drift of Ann Arbor; the others are from the Falls of the Ohio.
The outer specimen on the left-hand side of the plate resembles
considerably the basal portion of Zaphrentis gigantea. See Plate
LIL, base of large specimen.

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