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Nl-t B ULLETIN

f /

OF THE

LABORATORIES

OF

DENISON UNIVERSITY,

/

EDITED BY

C. L. HERRICK, M. S.,

PROFESSOR OF GEOLOGY AND NATURAL HISTORY.

VOL. 1.

GRANVILLE, OHIO, DEC., 1885.

Downs & Kxjssma.ul,

PRINTERS,

Granville Ohio.

Univer-

5T>7.73

, tG3 i>y/

Bulletin of the Scientific Laboratories of Denison
siTY, Granville, Ohio.

EDITORIAL STATEMENT.

Every well conducted institution of learning should form a recog-
nized centre of scientific activity ; and legitimately concerns itself, not
only with the instruction of those who directly entrust themselves to
its charge, but with the dissemination and conservation of information
relating to the subjects taught. Moreover, in connection with the
laboratory drill, it often happens that facts of general scientific interest
are brought to light which the student may be ill prepared to appreciate
in all their bearings. Such facts, if preserved, may, at another time,
become very valuable, while, if not thus preserved, they would be lost.
Still again, instructors will, as a rule, be unable to instill enthusiasm if
they themselves do not come in contact with nature at first hands,
while the fragments of time, which are often frittered away, can be
made most useful to themselves and others by being applied to studies
in advance of the work required by the curriculum.

The present publication, which we are able to present through the
genenous co-operation of numerous friends, is a step toward filling a
need hinted at in the above paragraph. The bulletin is intended to
represent the life of the college in its scientific departments and may
incidentally serve to illustrate to distant friends the facilities for work
afforded, as well as needs still unsupplied. To the scientific students of
the country we confidently appeal for support and indulgence, since it
is hoped to devote an increasingly large portion of space in each number
to technical papers which have more interest to the student than to the
general public. To the teacher, with still greater confidence, we look
for encouragement, as it is entirely in the interest of better school work
that this bulletin is prepared. While limited means has, in this first
number, prevented the use of costly illustrations, it is hoped that the
generous patronage of this volume will enable us to extend to the con-
tributors to the following one more elegant, if not more perspicuous
graphic aids.

A considerable number of papers prepared for this number have
been necessarily delayed, on account of the limited space allotted, and
yet our limits have been extended. The lithographs were executed by
the editor and printed by a process making them cheaper than any other
available, and any failure to realize the ideal of such work will, no
doubt, be pardoned on this account.

For information relating to the departments here represented, the
reader is referred to the advertisement appearing elsewhere. The fact
that the chemical laboratory has afforded us no material for this num-
ber, may be attributed to the change in administration in that depart-
ment, occasioned by the death of the lamented Prof. Osbun.

I.

THE EVENING GROSBEAK — Hesperiphoita vespertina, Bonap.

[Plate I and Frontispiece.]

Among the rarities in the cabinet of most ornithological collectors
is the Evening Grosbeak, which excites interest as much by its- com-
parative rarity and exceeding capriciousness in distribution as on ac-
count of its odd note and eccentric behavior. First found by Mr.
Schoolcraft, in 1823, near Sault St. Marie, in Michigan, it was de-
scribed by Cooper. The indefatigable naturalist, Sir John Richard-
son, encountered it upon the Saskatchewan, where seems to be its nat-
ural home, and from whence it issues forth, guided by any whim, and
wanders far to the East and South, though seeming to avoid the coast.
The genus is Asiatic and our two species are obviously derived from
the Old World, via Alaska. In Europe there is a closely allied genus
(jocc()th7'austes^ which differs in the shape of the secondary wing feath-
ers. The genus is distinguished from all other finches of the United
States by the very large beak and the following points :

“ Feet short ; tarsus less than the middle toe ; lateral toes nearly equal, and
reaching to the base of the middle claw. Claws much curved, stout, compressed.
Wings very long and pointed, reaching beyond the middle of the tail. Primaries
much longer than the nearly equal secondaries and tertials ; outer two quills long-
est ; the others rapidly graduated. Tail slightly forked ; scarcely more than two
thirds the length of the wings, its coverts covering nearly three-fourths of its
extent. ” — Baird.

[In America we have the two species, H. vespertina (with its two
varieties), and H. abeillii., ScL, which lives in the mountainous por-
tions of Mexico, southward.]

In very few places in the United States does this bird appear with
sufficient constancy to be set down as more than an accidental visitor.
In this respect Minneapolis, Minn., is particularly favored for, during
a number of years, these grosbeaks have rarely failed to make a longer
or shorter winter visit, sometimes coming early in the Autumn and re-
maining until the trees are in full leaf, when, in a few cases, their much

6

BULLETIN OF THE LABORATORIES

mooted song has been heard. The most eastern point yet reached by
these birds seems to be Cleveland, Ohio, and isolated cases of their- oc-
currence in Wisconsin and Illinois are also known. The species is
highly gregarious and individuals are rarely or never met with singly.
Even the destructive inroads of the collector, before whom they are
absolutely defenseless, do not scatter or break up the flock. Unsus-
pecting and without fear, they continue to feed until the last individual
falls a victim. The migrating colony seems well satisfled with itself
and its temporary home and, while feeding, a constant chorus of an-
swering cries is kept up. The note is not loud but is remarkably
piercing, and yet not unmelodious. The early belief that these birds
are silent except at evening is entirely erroneous. In spring, upon the
approach of the breeding season, the males cultivate the muses in an
odd but not displeasing little song. This song consists of several suc-
cessive repetitions of a short warble, followed by a similar strain clos-
ing with a shrill cry, like the finale of a black-bird’s song. The phrase
which makes up the body of the song is musical, but is so abruptly ter-
minated (as though from lack of breath or of ability, ) that it is annoy-
ing when heard singly, for one is subjected to much the same nervous
expectancy felt in listening to a hen’s cackle when quite leisurely
“working up the agony” sufficiently to sound the final note. A
flock of a dozen or more singing together produce a very musical ef-
fect. The food almost entirely consists of the seeds of various trees,
among which the box elder, the maple, poplar, and pine are pre-emi-
nent. Buds of cherry and other trees are also eaten, and this regime
is varied by occasional insect larvae, etc.

O. R. Johnson, who mentions this grosbeak from the Williamette
valley, speaks of it as plentiful during migrations, and states that “ the
only note heard was a loud yeeip^’’ strikingly like the call of a lost
chicken.” Of the nest and eggs we as yet know nothing, and so of
the many interesting traits which make up the sum of its true home-
life we must be content to remain ignorant. From its inaccessable
summer home it continues to descend during the severe winter weather
and, almost under the very roofs of the factories of a busy city, con-
tentedly passes the short days, heedless of the noise and regardful only
of the oily kernels of the keys of the box elder, which it displays
a very awkward skill in plucking as it swings (head downwards or oth-
erwise) from the pendulous branches.

These brief remarks are designed simply as introductory to the

OF DENISON UNIVERSITY.

7

notes on the osteology appended. Before preceding to these the fol-
lowing description will suffice to make the bird recognizable.

Sj). cJiar. Bill, yellowi.sh green, dusky at base ; anterior half of body dusky
yellowish olive, shading into yellow to the rump above, and the under tail coverts
below. Outer scapulars, a broad frontal band continued on each side over the
eye, axillaries, and middle of under wing coverts, yellow. Feathers along the ex-
treme base of bill, the crown, tibiae, wings, upper tail coverts, and tail, black ; in-
ner greater wiug-coverts and tertiaries, white. Length, 7.30, wing, 4.30, tail, 2.75.
In the female the head and back is dull olivaceous brown. Below, the body is
pale yellowish ash. There is an obscure black line on either side the chin. There
is more white upon the wings and tail. (See p.late, which is intended to give
simply the tout msemble without strict accuracy as to color.) ' .

Osteology of Hesperiphona vespertina.

The anatomy of the Evening Grosbeak is of more than usual inter-
est, not only on account of the rarity of the bird and the air of mystery
wh)ch has associated itself with it, but because it stands at the head of
American Fringillidae^ by virtue of possessing the extreme develop-
ment of the finch type of structure. Our observations are based on
the study of three more or less perfect skeleta, wffiich, so far as we
know, are the first which have been studied.

The skitll. The most striking peculiarities of the skull are those
which are corelated with the extraordinary development of the beak.
The angle, for instance, formed by the quadratojugal-jugal bony pillar
with the lower margin of the maxilla is greater than usual, chiefly on
account of the great size of the quadrate bone. In this way a firm
support is afforded to the upper jaw. But we pass to a detailed de-
scription. As seen from above^ the skull is, in outline, a perfect trian-
gle, with a narrow rounded base. The apex of the triangle is formed
by the remarkably large and strong (though correspondingly very light)
beak. The bones entering the beak are cancellated within, forming a
firm but light organ. These bones are, first, the pt'-emaxilla^ which
makes up the bulk of the bony frame-work of the beak and is early
anchylosed with the maxillaries in the family under consideration.
Although we can not separate the parts, we may distinguish in the max-
illary bone a superior or nasal process which separates the opening of
the nares and unites with the nasal bbnes, two lateral or maxillary pro-
cesses, and two palatine processes which are within the mouth-opening-
The distance from the apex of the beak to the subcircular nares is .6
inches, the distance between them, .10. The nasals are inseparably

8

BULLETIN OF THE LABORATORIES

united and form a quadrate bone making an angle of 25° with the cul-
men or upper line of the beak, their combined width is .45, and they
form the posterior borders of the nares, being united laterally with the
maxillaries, anteriorally with the intermaxillary, below with the lachry-
mals, and posteriorly with the frontals. The distance from the angle
of the mandible to the top of the nasals is .40. Occupying the top
of the skull, and apparently restricted to the space between the orbits,
are the concave frontals. The distance between the orbits is about
.35. The remainder of the roof of the skull is formed by the con-
fluent parietals which occupy a larger area than usual on the top and
back of the skull. From above can be seen a small prominence be-
hind, which covers the cerebellum, and hence is called the cerebella}'
prominence,. The sides of the triangle are continued backward from
the ends of the maxillaries by a slender rod consisting of the qiiadra-
tojugal and the jugal which can be studied to advantage when the skull
is viewed front the side. In this position the skull is seen to present
the outline of two triangles, the smaller of which, forming the beak, is
set at an angle of 45° with the other. The cutting edges of the jaw
(tofnia), supported chiefly by the maxillary bones, are slightly curved.
The tomia are .80 long. The slender rod passing backward and
downward and forming the lower outline of the second triangle is, in
the young, composed of two bones, the jugal and quadratojugah
Their combined length is . 54, the posterior articulation being upon the
outermost process of the peculiar quadrate bone. This bone is con-
sidered the homologue of the little ear bone of mammals, known as
the malleus, but in birds has a very important function — that of giving
the necessary movability and yet stability to the beak. It is the point
of attachment of the two important supports of the facial part of the
skull. The form of the quadrate is very irregular, consisting of a
l3ody and six processes. The styloid process is the largest and is that
which connects the bone with the base of the skull ; it is a flattened
vertical pillar with a large articular surface; jutting out anteriorly is the
orbital process, about .30 long, which extends into the orbit. Just
below the orbital is the pterygoid process of rather small size. The
mandiblar end bears two curved processes, so situated that the glenoid
surfaces oppose the rami from within and behind, while the jaw is com-
pletely locked by the large articular process of the mandible. A more
complete articulation could scarcely be conceived. The malar pro-
cess extends out horizontally and offers an oblique surface to the head

OF DENISON UNIVERSITY,

9

of the quadrato-jugal. The lachry7nal bone is very large and hoe-
shaped, occupying the whole anterior aspect of the orbit. A very
slender curved process extends backward from its lower angle. The
lachrymo-nasal space between this and the maxillary permits the free
movement of the beak on the skull. The lachrymo-nasal foramen is
quadrate. The optic foramen occupies its usual position on the mar-
gin of the ali-spkenoid, which is inseparably united with the septum
inU'ao7'hitale and this with the ethmoid still farther forward. There
is a large irregular foramen above the optic. The greater part of the
side of the skull behind the orbit is formed by the squamosal^ which is
strongly ridged and forms, first, a strong flange-like process behind the
orbit and, second, a very long process projecting forward toward the
corresponding process of the lachrymal. The ot'bito-spheiioid was not
detected as a distinct bone, but irregular processes on the ali-sphenoid
may represent it. The sclerotals are membranous bones, which unite
to form a ring about the globe of the eye. As seen from below, sev-
eral new bones appear. At the back of the skull is the large foramen
subcordate and quadrate in form and about .20 in width.
Above, it is bounded by the supraoccipital^ laterally by the exoccipitals^
and below by the basioccipital. These bones are intimately united
and the sutures quite obliterated. There is an impressed line on
either side the' foramen. The single occipital condyle is a small knob-
like process. The basioccipital is quadrate and near its lateral mar-
gins are the foramina of the carotid and the seventh, ninth, tenth and
eleventh nerves. The squamosal expands into a large shield-like cov-
ering over the auditory meatus. Just inside of the quadrate bone can
be seen a bony sheath which indicates the former point of union of the
Meckel’s cartilage. Within the meatus the minute auditory ossicles
can be seen with a glass. The sphenoid is a pyramidal bone, soon be-
coming a vertical plate fusing with the ethmoid and inter-orbital sep-
tum. Here also the obliteration of sutures is complete. The vo7ner
is present but inconspicuous. The 7naxillaries form the sides of the
beak and, in connection with the premaxillary, form a continuous bony
ceiling to the roof of the mouth, which is covered with a thick horny
sheath, so thickened on the edges as to make the knife-like cutting
to77iia. The palatals are movably articulated to the edges of the max-
illaries by broad bases so that they nearly meet on the median line and
reach nearly to the jugal, externally. Posteriorly, the palatals extend
into forked processes, making the whole length .40 of an inch. From

lO

BULLETIN OF THE LABORATORIES

this process, which descends below the level of the jugal, a nearly ver-
tical plate extends upward to form a sliding sheath which clasps the
pres-phenoid and plays back and forward upon it. The flattened ends
of the long (.50) pterygoids are fused with these vertical plates by ex-
panded, overlapping plates. There are two curved flanges springing
from the point where the pterygoids unite with the palatals. The eth-
7no-turhmal plates are more or less ossifled and are seen on either side
of the rudiment of the vomer. The pterygoids are stout but very
unusually long and, on account of the size and position of the quad-
rate bones, are quite distant from the basis cranii. Near the point of
union of the pterygoid with the quadrate bone, a small hooked process,
about .12 long, extends upward from the former bone. What the use
or the homologies of these processes may be, we do not know, although
they occur in finches and in other birds.

At the posterior of the two mandiblar processes of the quadrate
bone is a bone as large as the head of a large pin, but of irregular
shape, which may be regarded as either a sesamoid contributing to lock
the jaw or an independent portion of the quadrate. There is also a
very minute sesamoid at the union of the quadrato-jugal and the quad-
rate. The lower jaw shows no evidence of its composite character.
The whole anterior half is enlarged and forms a simple trough of can-
cellous bone which may be assumed to consist of the dentary elements
of both rami. The surangular, angular and splenial elements of the
rami are not distinguishable. The articular portion consists of a huge
flange, extending inward and upward and is perforated at the middle of
its inner surface for the entrance of Meckel’s cartilage.

What corresponds to the surangular portion is a broad triangular
plate extending upward inside the jugal bones and serving to further
lock the jaw. Thus, as we have seen, the whole skull is modified in
harmony with the enormous rhinencephalic development.

The hyoid arch is well developed and consists of seven bones,
whose homologies, in the present state of our knowledge, cannot be
made out. The anterior pair are pointed before and behind, and at-
tached at the middle to each other and the end of the azygos bone
which next follows. The first mentioned bones are called entoglossal^
by Gegenbaur, by some American authors, ceratohyals, with no real
evidence that they are homologous with the bones so called in other ani-
mals, The following element may be called basihyal {^copula of
G^gQnbaiier,) and is flattened to form a vertical plate and bears on

OF DENISON UNIVERSITY.

II

either side, posteriorly, the cornua, which each consists of one straight
shaft, .50 long, and a shorter fusiform segment. Between these the
ttrohyal extends backward as a support to the trachea. The atlas
and axis are fused together more or less fully. There is no neural
spine on the atlas, but its dorsal surface is perfectly plane. The axis,
or second cervical vertebra, has a well developed spine and posterior
zygapophyses and also a very large haemal spine, which curves back-
ward. The third ce^'vical has a smaller neural spine and its poste-
rior zygapophyses project upward. Its haemal spine (hypapophysis)
curves forward. There is a slight inferior lamella of its transverse
process. The fourth cervical introduces a new type, having a low
spine, nearly horizontal posterior zygapophyses, and elongated styloid
inferior lamellae. It has a smaller haemal spine. The following cer-
vicals have no neural or haemal spines, the posterior zygapophyses de-
cline, and the styloid appendages are very long. The thirteenth and
fourteenth (last) cervicals have pleuropophyses (ribs), those of the
former being mere rudiments, while those of the latter are large but
have no connection with the sternum. These vertebrae, in common
with the first of the dorsals, have strong haemal spines. They also
have the capitula process well developed to receive the head of the
rib. The transverse process has its normal tubercular facet to sus-
tain the tubercle of the rib. There are six dorsal vertebrcE, which
are more or less firmly co-ossified. The transverse processes are

large and the spines of uniform size. The last dorsal is firmly united

with the following nine vertebrae, which form the vertebral framework
of the sacrum. Seven free vertebrae follow, forming the free caudal
series. Each of these has a strong transverse process and a more or
less perfect neural spine. Upon the last two there are also haemal
spines. The last bone or pygostyle is remarkable for the great devel-
opment of its neural spine.

The sternum is normal for the group and is 1.20 inches long. The
keel is well-developed, being .50 high. The mid-xiphoid process is
.40 wide at the end. The lateral xiphoids are separated by an excis-
ion one half as wide and rather more than .40 deep. The transverse
sternal angle (that between the two sides of the body of the sternum,)
is sharp and considerable. The costal processes are strong, while the
coracoid grooves are .25 in width. The manubrium is particularly
large and is bifid. Each of the six ribs, as well as the last cervi-
cal rib, has a well developed uncinate process.

12

BULLETIN OF THE LABORATORIES

The strongest bone in the shoulder girdle is the coracoid^ which
is expanded below and obliquely winged for a short distance, then
is cylindrical and then curves inward, throwing off a flange-like
process where the scapula is articulated, and ends in an articular
surface against which the flattened upper part of the clavicle is
pressed. From the lower angle of this surface a strong tendon
passes to the process of the manubrium on that side. The clavicles
are of the usual form, forming the merry-thought in connection with
the anchylosed interclavicle. The scapula is united to both clavicle
and coracoid and with the latter furnishes a glenoid surface for the
humerus. Between these three bones, at their union, is a cavity, fora-
men triosseum, permitting the passage of the tendon of the sub-cla-
vius muscle.

The anterior extremity is of moderate size. The humerus is
long and is much expanded proximally where it is .33 in breadth.
The radial crest is short and quite prominent. The ulnar tuberosity
is v6ry large and outwardly presents a large triangular surface and
within excludes two extensive fossae, divided by a strong septum, from
the end of which a strong process is developed. The opposite or
distal end of the humerus is less highly developed, but still shows a
high degree of perfection of the spinous appendages. The trochlea,
consisting of the radial and ulnar tubercles, are about as usual. The
radial condyle is a small prominence directed forward at the base of
the radius, while the ulnar condyle is a larger acute process, extending
in the opposite direction. The radius, the smaller bone of the arm,
is but slightly curved and measures 1.20 in length. The ulna curves
considerably, proximally, so that the sigmoid cavity is quite oblique to
the shaft, and the olecranon process is small and styloid. The carpus
contains two bones which have the usual positions. The ulnar e is
applied to the back side of the ulna and rotates upon its smooth articu-
lar surface. The radiate caps the ulnar and is overlapped by the ra-
dius in front. The three metacarpals are fused at the base. The
first one can not be distinguished and its phalanx measures but .20.
The second metacarpal is .65 long and is fused at both ends with the
slender third metacarpal. The second digit consists of two phalanges,
the first of which is .30 long and consists of two bars connected by a
thin plate of bone, the second being a triangular plate . 1 5 long. The
third digit consists of a styloid phalanx .20 long. (The two ossicles
described by Schufeldt, in certain birds, as the cimeiform and the pen-
tosteon, are not discoverable in any of the skeleta before me.

OF DENISON UNIVERSITY.

13

The pelvis is papery and yet very complete. The obturator fissure,
separating the ischiitm and piihic moiety of the pelvis is divided into an
elongated posterior and smaller circular anterior foramen. The ilio-
siatic foramen is quadrate, with rounded angles. The pubic bone is
produced into a slender curved process, as usual in this group. The
femur is .91 long and nearly straight and requires no description.

The tibia is a symmetrical straight bone, 1.30 long, while the fibula
is nearly free from it and is about half its length. In the skeleta of
adult birds, such as those before us, it is useless to attempt to distin-
guish the tarsal bones which unite with its epiphyses, thus forming the
tibio-tarsiLs ^ nor yet the composition of the succeeding segment of the
leg, the tars o-metatars ICS. The latter is .80 long and is furnished with
a strong process (“ calcaneal,’’) behind, which is at present causing so
much discussion. The subdivision at the distal extremity into the
four metatarsals is distinct. The first of these, the hallux, is provided
with a separate matatarsal, the accessorius, which is quite large and de-
scends to the level of the other united metatarsals. The phalanges
of the hallux are two in number, the first being very large, .32 long.
The claw borne by the following phalanx is the strongest on the foot.
The second toe has three phalanges, the third, four, and the shorter
fourth, five, as is the case in all of the present group of birds.

wSuch a bare description as is above given of points in the osteology
of a species of bird, is of little value, except as furnishing a basis for
comparison with others of its own and other groups. Such a com-
parative study we cannot at present attempt, but may, perhaps, profit-
ably note some points of difference between the present species and
others of its own family, FringiUidae. Quite at the other extreme
of the family may be found the genus Pipih, which is represented in
our region by the Chewink or Ground Robin, P. erythropthalmus,
a bird of singular appearance, in some points resembling the Orioles,
while mimicking the habits of the Brown Thrush. A comparison with
this species then may be expected to give us the limit of divergence in
structure within the family, and those points which are identical in
both may, with some probability, be assumed to be of family, ordinal
or class rank.

The skull is of very different form, but the differences are
chiefly those accompanying the reduction in the size of the beak,
which in the Chewink is slender, almost Icterine. This slender point-
ed beak does not extend backward so far as in the true Finches, but

14

BULLETIN OF THE LABORATORIES

the malar pillar is much longer and the angle of the beak and
the end of the tomia are forward from the orbit. The opening of the
nares is much larger and the lachrymo-nasal space is a very large tri-
angular opening. On this account the ascending process of the max-
illary is quite slender. As seen from above, the skull of Pipilo is
much narrower between the orbits and the facial portion of the skull
is easily distinguished from the cranial. The orbits are rather larger
and not nearly as well guarded. The lachrymal is of the same shape,
but lacks the long slender process directed backward, below. The
lachrymo-nasal foramen is small. The interorbital septum is very
poorly developed, two oblong foramina extending longitudinally leave
but a narrow bridge between them. The ethmoid is therefore greatly
reduced. The back of the skull is alike in both, but the opening of
the bullse is directed more forward. The palatal bones are quite sim-
ilar, but the posterior processes are not bifid. Two curved slender
rods, which seem at least partially ossified, pass from the palatal pro-
cesses of the maxillary to that part of the palatals farthest forward and
highest. The pterygoids are of the usual shape and are flattened an-
teriorly to slide over the sphenoids The quadrate is smaller and of
the same form, but has a rather longer orbital process, proportionally.
The quadrato-jugal has the same hamular process posteriorly as described
in the Grosbeak. The lower jaw is, like the upper, rather weak.
The various parts entering into each ramus are indicated by the pres-
ence of a large oval foramen separating the surangular, angular and
splenial, and the flange of the articular is large. The differences in
the shoulder and arm are slight and are such as might occur in species
of the same genus. The sacrum is relatively much stronger and the
spinous armature is greater, this corresponding to the greater demand
upon the muscles there finding origin. The foramina are of the same
number, but the lower one is more elongated to correspond to the
greater development of the pubic bone. The femur is of ordinary
form, but the tibiotarsal segment is greatly enlarged. The. fibula is
quite well developed and is anchylosed with the tibia about one half
an inch from the head, for a short distance, but is free above and be-
low. The head of the tibia develops two huge processes and there
is a small patella. The condyles are very large. The calcaneal”
process, strangely enough, is very small and poorly ossified. The
foot itself is not particularly enlarged.

The form of the sternum is very closely alike in these birds ; in

Bulletir) of the Laboratories of Denisorj University.

PLATE 1.

OF DENISON UNIVERSITY.

15

fact, the sternum is a valuable osteological index, for, not only is it
pretty constant in a given family, but it presents points of constant
difference between many families. The manubrium is larger, if any-
thing, than in the Grosbeak.

Such are some of the differences noted between these species and
they may be taken as indications of those points in the osseous struc-
ture most readily responding to changes in habit or habitation as in-
duced by changes in the environment. It is by the elimination of
the variable elements of different degrees of constancy that classifica-
tion can be placed upon a permanent and correct basis. The vari-
able points may be employed in distinguishing species, genera, etc., in
accordance with their relative permanence or value.

Plate I. Anatojny of Hesferiphona.

Fig. I. Lateral view of entire skeleton.

Fig. 2. Skull seen from below. Qj, quadratojugal ; PI, palatal ; pt, ptery-
goid ; sp, sphenoid ; e, condyle ; Fm, foramen magnum ; L, internal flange of
mandible.

Fig. 3. Transverse section of skull, V, vomer ; Q, quadrate bone ; Of,
optic foramen ; other references as above. ^A, diagram of bones of skull.

Fig. 4. Quadrate bone and articulations. Pt, pterygoid ; Qj, quadratoju-
gal ; a, accessory ossicles ; m c, sheath of Meckel’s cartilage.

Fig. 5. Hyoid arch.

Fig. 6. Superior surface of a cervical vertebra.

Fig. 7. Humerus.

Fig. 8. A dorsal vertebra, from behind.

Fig. 9. Muscles of the wing seen from above.

Fig. qA. Anterior part of wing from below.

Fig. 10. Skull denuded of skin and showing certain cervical muscles.

II.

METAMORPHOSIS AND MORPHOLOGY OF CERTAIN
PHYLLOPOD CRUSTACEA.

■ [Plates V— VIH and Plate X.]

The group Phyllopoda is one of the most remarkable among crusta-
ceans, on account of the peculiar form and life history of most of its
members. About the animals of this group there clings a certain air
of mystery which may lead one to regard them as almost uncanny.”
A pool by the wayside is suddenly formed by a shower and almost in-
stantly becomes populated with a swarm of animal life, which no one
ever saw there before and for the like of which we might search an
hundred miles in vain. In a few days the little tragedy is played and
the uncouth actors have disappeared, no one knows whither, having
sown the clay at the bottom of the now dry pool, with eggs which,
under favorable circumstances, may again put the play on the boards,
but only after being themselves thoroughly dried by the sun. In
short, in the study of these animals the unexpected is always appear-
ing and known laws, or at least theories, are again and again negatived.
We calmly institute a species when, lo ! the change in certain condi-
tions attending the development occasions the change to an entirely
different genus in our system.

(See V. Siebold, in Sitzungsberichte d. math.-phys. Classe zn Muenchen^ 18735 ^‘i^l
the paper by Schmankewitsch in the Zeitschrifi fuer Wissenchaftliche Zoologie, XXV
Suppl., 1S75.)

In spite of many able papers and works on American Phyllopods
(notably the monograph, by Prof. Packard, in The Geol. Siirv. Terj\^
1868, Part I ^ Sec. 2.) many points of deepest interest remain to be
cleared up, and particularly such as relate to the development history
and homologies of organs. In the present paper a few observations
made some years ago, are presented with no attempt to discuss their
bearing upon the questions in dispute. The student conversant with
the literature of this subject will observe, however, that these facts

OF DENISON UNIVERSITY.

17

make necessary a modification of views at present in vogue in several
important particulars. The work was arbitrarily closed by circum-
stances and the material was long suppressed, in the hope of continu-
ing a study which proved of absorbing interest ; but, as this hope is
now extinct and no motive remains for further delay, the observations
are presented in their necessarily fragmentary form, hoping to fill a
place in the life-history of these remarkable animals.

The Phyllopoda are extremely well adapted for use in biological
laboratories and the outline here given may make the process of de-
velopment plainer to the student who is fortunate enough to be sup-
plied with such material for study. The two animals described may
be found in early spring and late summer, in many temporary pools
throughout the eastern zoographical province of North America.

A. Larval Development of Limnetis gouldii, Bd.

Limnetis is a genus of the Family Limnadiad^ of Baird, which
includes crustaceans enclosed in a bivalved shell, within which is con-
cealed a body like that of a Water Flea, but havi^ng ten to twenty-
seven pairs of leaf-like swimming feet. The very large head projects
from between the valves in front and is flanked on either side by a
biramose second antenna, while the first pair of antennae is very small.
A figure of the adult of the present species will be found in the mono-
graph by Dr. Packard, and also in a paper by the present writer, in the
loth Annual of the Minnesota Geological Survey.

The earliest stage seen (Plate VI, Fig. 2.) was the simple nauplius-
form common to all this group of Crustacea, but so curiously modified
as to at first almost defy recognition. The animal, as viewed from
above, seems covered almost entirely by an oval shield, which is thickly
studded with spines arranged in anastomosing lines. The head ex-
tends into a frontal prominence, which is densely bearded. The pos-
terior part of the body forms a blunt prominence, bearing two spines.
The eye, occupying the front of the head, consists of a single pig-
ment fleck, with at first a single lense (?). The digestive tract is
simple and similar to that of other Phyllopod larv^. In the protu-
berance which represents the future abdomen, the muscles producing
the pumping action of the rectum are well developed and anal respi-
ration at once begins.

The appendages differ only in form from those of other larvse.
The antennules are long aud curved prolongations of the frontal region

1 8 BULLETIN OF THE LABORATORIES

and project laterally. They are covered with a spiny cuticle, like
the antennules of the nauplius of Chirocephalus^ but are less movable
and less obviously tactile organs. It has been denied that these are
really antennae, but the history of their further development makes it
clear that they are really representatives of those organs, though ob-
scured by their covering.

Although the nauplius of Limnetes is said by authors (Packard,
Monogr. Phyllopod Crust, etc.) to be distinguished from other nauplii
by the small size of the labrum, this is founded upon a mistake. The
labrum is really the most prominent of the larval organs. It is,
indeed, of monstrous form and is so enlarged as to become a valve
nearly as large as the shield-like expansion of the body above. The
larva resembles a small turtle, from the edge of whose shell protrude
two pairs of appendages.

The labrum is thorned, as is the whole body, and is slightly, if at
all, movable. In this respect it differs little from other young nauplii.
Like the first pair of antenna, the labrum is obscured by its larval
envelope, similar to that which extends the carapace of the body to
form a false shell. The second antennae are of the usual form among
Phyllopods, the anterior branch being five-, the lower one two-jointed.
The basal portion is furnished with a prominence bearing two heavy
claws. The palp of the mandible is of the usual form.

In the next stages slow changes accompany the increase in size-
A dorsal area is marked off over the maxillary and mandiblar seg-
ments, from which the shell develops under the larval covering. The
nauplius eye becomes associated with a pair of club-shaped sensory
hairs. A ventral swelling becomes distinct and proceeds to segment
itself and elaborate limbs. (Fig. i, Plate VII.) In figure ii of this
plate, which gives a semi-diagramatic under view of the abdomen, is
shown that, as in other Phyllopods, the appendiculate segments seem
to appear at once and the development goes on then from before back-
ward. Prior to the appearance of feet (stage of Fig. i.) the animal
is about 0.33 mm. long, but becomes over 0.50 mm., before the meta-
morphosis. In the last stage prior to assuming the characteristics of
the adult, the antennules seem smaller, the labrum has become cordate
and very wide, while a prominence appears below the eye. Rudi-
ments of the compound eye are visible and the sensory filaments over-
lying the pigment fleck are developed. The anterior part of the
digestive tract has bifurcated and its branches extend toward the labrum..

OF DENISON UNIVERSITY.

19

The accessory branch of the second antenna, with its forceps, has be-
come large. Now the hypodermic contents of the antennules with-
draw from its shell and compact themselves into the mature form, de-
veloping, at the same time, sensory rods in their substance. The con-
tents of the labrum fall away from the walls and gather into a lobe-like
body. Feet have formed, and a single-chambered heart is actively
pulsating. The future shell may now be seen under the larval cover-
ing, connected only with the back over the segments bearing gnathites,
and hanging free about the edges. When the moult is affected the
labrum falls within the valves, carrying with it the small tactile anten-
nules, which hang pendant by a slender stalk. The frontal promi-
nence, however, is elongated, forming the beak. The larva is now a
diminutive of the adult. In its future development the form elongates
and finally again becomes rounded and assumes the familiar appear-
ance. The branches from the stomach fill the front of the head with
so-called liver-lobes. The compound eye becomes perfected, while
the nauplius eye is covered by filaments charged with some unknown
sensory function. The heart becomes multi-chambered and the geni-
tal organs appear. For a figure of a young Limnetes, see Types of
Animal Life^ etc.^ by the author; for figures of the adult and a discus-
sion of relationships, see Packard’s “Monograph of the Phyllopod
Crustacea of America ” ; U. S. Geol. Surv. of Terr. 1878, Part /.

Farther details may be gathered from the plates. It is a matter of
regret that Grube’s work on the development of the European Lim-
netes hrachyura was not accessable to me during the period which was
covered by this paper. My recollection is, however, that the pro-
eesses are, in the main, identical, but that Grube fails to identify all
the organs of the embryo.

B. Post-embryonic Development of Chirocephalus.

The species studied is assumed to be the common C. holmani.^ Ryder,
although the oldest male seen differed in several particular from the
description of that species. One must imagine a fish-like, transparent
animal, about one-half inch long, balancing itself in the water by the
movement of eleven pairs of lamellate swimming feet. The colors
are brilliant and do not interfere with an almost perfect transparency of
the body.

The earliest stage seen is that figured on Plate V, Fig. i. The
animal is at that period .93 mm. long and the antenna measure about

20

BULLETIN OF THE LABORATORIES

.57 mm., the antennules .32 mm. The form is that of a nauplius
toward the end of its first phase. The antennules are much like
those of males of Moina, being curved abruptly near the middle.
They are clothed with a spiny larval integument, which disappears in
the next stage. The sensory ganglia in the end and the connecting
nerves are present; of the latter there seem to be two bundles having
a different course. The larval eye in the middle of the head is dis-
tinct and has two lenses, or, rather, crystalline bodies.

The antennas are of the form usual to larvae of this family, the
rami being unequal, the shorter being very indistinctly two-jointed, the
longer eighteen-] ointed. Near the base a small prominence bears long
spines, later to serve a temporary purpose in bringing food to the
mouth. The mandiblar palp is indistinctly 6-j ointed, the inner ramus
of this limb, or mandible proper, has a single spine.

The thoracic segments are already indicated and rudimentary limbs
lie under the larval skin. The abdomen bears two styles, and has a
set of muscles adapted to produce anal respiration in the rectum. The
stomach is simple and glandular. Although no heart could be distin-
guished, blood corpuscles crowd the antennae and other parts of the
body, (see figure 4.) Rudiments of the compound eyes are seen on
the sides of the head where pigment is collected.

In the next stage the animal may be .98 mm. long (Fig. 2.) and
several changes appear. A well marked scutum covers the mandib-
lar and maxillary segments. The antennules have lost their spiny
covering and the proportions of the antennae have changed. At the
base of the antennae certain organs develop, which present great re-
semblances to the branchial sacs of the other feet, but which become
the shell-glands of the adult. This is parallel to the like origin of
these organs in copepods, as we have demonstrated in Diaptomus. In
Limnetes it was impossible to follow the development of the shell-
gland. (See figure 6, 0, shell gland; mouth; A, labrum ; d/ff,
mandible; Mx, maxilla; A/x 2, second maxilla.) The brain lobes
or supra-oesophagal ganglia resemble those organs in cladocera, the
optic-lobes being apparently hollow, however. ' The posterior part of
the body is now considerably elongated. The segments of the thorax
seem to be all differentiated at once and the segmentation is obscured
by a false segmenting of the posterior part of that region or the appa-
rent absence of segments. The region about the rectum is open and
grossed by the muscles giving it motion. It frequently seemed to me

OF DENISON UNIVERSITY.

2t

that this chamber was that in which the blood-corpuscles (or, better,
lymph-cells) were formed. The rectum is covered with irregular
masses of cells of varying size, and I more than once thought to have
observed their change to lymph-cells. It was impossible, unfortu-
nately, in the time allotted to observe the development of the circu-
latory system, but it would seem that the heart differentiates from the
connective tissues between the stomach and the scutum.

(Fig. 3 illustrates not only the formation of the posterior appendic-
ular segments, but the rectal sinus with its muscles and lymph-cells.
A simple valvular apparatus separates the rectum from the anterior part
of the digestive tract. )

The next stage is illustrated on Plate VI, Fig, i. A change in
proportion and in size is all that requires notice. Figures 3-6, illus-
trate the growth of the appendages. Fig. 3 is the first foot of the
right side of an individual over 1.5 mm. long. Fig. 4 is the same of
a younger individual of which Fig. 5 is the sixth and Fig. 6, the ninth
foot. Fig. 7 shows how the matrices of the caudal spines are devel-
oped from enlarged cells as are the corresponding parts in Daphnia.

Fig 2, of Plate VII, illustrates the general characters of the animal
when about 2 mm. long. The maxilla have become larger and the
feet begin to assume their definitive form.

Fig. 3 shows the growth of the caudal stylets and the character of
the valve at the opening of the anus, as well as the prolonged matrix
at the setae. Fig. 4 illustrates the differentiation of the optic lobes
and of the anterior part of the stomach. The heart is by this time
well formed and whatever part the rectal cells may have played in
originating lymph-cells, is lost. The liver lobes grow out from the
stomach and the labrum becomes reduced. The antennae now un-
dergo a rapid and remarkable transformation. In the male the shorter
ramus becomes atrophied as shown in Fig. 10, and from the base an
epipodal body is formed just as in the case of the feet. At first this
pouch resembles homologous organs in the feet, but soon it alters and
becomes greatly modified. In the female the change is similar, save
that this branchial sac fails to develop (Fig. 9.) The palpus of the
mandible is likewise reduced to a mere rudiment (Fig. 8.)

The sexual organs of the female appear as lobed glands
(Fig. 12.) The caudal stylets are of considerable size. A
male, in the stage above mentioned, measures 3.5 mm. In the
following stages growth is rapid. The antennae modify rapidly.

BULLETIN OF THE LABORATORIES

Figs. 2 and 3, of Plate VIII, show the form of the antennae of the
female and male in this stage, the former being .78 mm., the latter
.79 mm. long. In the male the palp is gone and the appendage is
considerably developed, the longer ramus still showing its primitive
form. Fig. 4 figures the fourth foot of a male ^ inches long. Fig.
5 shows the abdomen of a larger male, and Fig. 6, the stylets when
they are . 78 mm. in length. Fig. i shows the form of the head of a
male some time prior to maturity, and Fig. 8 illustrates the external
genital organs of one side at the same period. The testis, only part
of which is shown, is a double chamber. The penis is paired and
each factor is spiny. A common muscle protrudes them both by lateral
pressure, while a muscle peculiar to each serves as a retractor. Fig.
7 illustrates the form of the male antenna, previous to the branching
of the so-called frontal organ. As to the homologies of the ‘‘frontal
organ,” there is no doubt that in Chirocephalus, as stated many years
ago, it is an appendage of the base of the antenna and the develop-
ment shows it related in position and formation to the branchial sacs of
the other limbs.

There is a curious dimorphism among these animals, as in cope-
pods. The males, under , certain circumstances, become sexually
mature, while the antennae retain an undifferentiated character. The
antenna in this stage, has a short basal process and the remainder is
rather short and bifid at the tip, one of the branches bearing a sharp
spine. The frontal appendage is simple, coiled, and regularly crenu-
late in this stage. The next stage is characterized by the elongation
of one of the short branches at the end of the male antennae and the
modification of the frontal organs.

Explanation of Plates.

Plate V.

Fig. I. Young nauplius larva of Chirocephalus.

Fig. 2. The same in an advanced stage.

Fig. 3. End of body of individual of same age as figure i, showing cavity
about the rectum and its muscles, the cells springing from the walls of the rectum,
the blood corpuscles, the valve at the posterior end of the stomach, and the prim-
itive segments outlined in the cellular mass.

Fig. 4. End of the longer branch of the second antennce, with massed blood
corpuscles.

Fig. 5. Mandible and palpus.

OF DENISON UNIVERSITY.

23

jF/^\ 6. Lower view of anterior part of a larva, about the size of that shown
in figure 2, oc. nauplius eye ; Ai, antennse ; e, eye ; upper ganglion ; ^i, optic
lobe ; A 3, swimming antennge (base only shown); M, mouth opening, bordered on
either side by commissures passing to the infra-oesophagal ganglion ; L, labrum ;
Md, mandible and palp ; Mx, first maxilla ; Mx 2, second maxilla ; //, III, IV,

etc., feet in different stages of development.

Plate VI.

Fig. I. Chirocephalus larva in an advanced stage, seen from above.

Fig. 2. Limneies goiddii, early stage,

Fig. 3. First right swimming foot of Chirocephalus when 1,4 mm. long.

Figs. 4-6. First, sixth, and ninth feet of younger larva.

Fig. 7. Abdomen of same.

Plate VII.

Fig. I. Larva of Liumetes .33 mm. long. A, first antennae ; A 2, swimming
anteniiEe; Md, mandiblar palp, e, eye; /, lense ; L, liver, budding from anterior
part of stomach ; j-, sensory filament ; in, muscles of rectum.

Fig. 2. Larva of Chirocephalus, from below.

Fig. 3. Caudal stylet of same.

Fig. 4. Flead, showing organs of one side, L, liver.

Fig. 5- Muscles of swimming antennae.

Fig. 6. Maxilla. Fig. 7. End of abdomen of an older individual. Fig.
8. Mandible and palpus (/) in this stage. Fig. 9. Antennae of female. Fig.
10. Antenna of male ; /; inner ramus ; g, frontal organ.

Fig. II. Part of Limnetes older than figure i.

Fig. 12. First abdominal segment of female, seen from below.

Plate VIIL

Fig. I. Head of male approaching maturity.

Fig. 2. Antenna of female, (length of antenna .78 mm.)

Fig. 3. Antenna of male of about the same age, (length of antenna .79 mm.)

Fig. 4. Fourth foot of male ^ inches long.

Fig. 5. Abdomen of young male.

Fig. 6. Caudal stylets of same, (.78 mm. long.)

Fig. 7. Antenna of same.

Fig. 8. Copulatory organs of one side, m, muscle common to the sheaths of
both male organs ; p, penis or forceps ; t. testis.

Fig. 9. End of sensory antenna ; a, sensory rods, enlarged.

■Fig. 10, Yiqw Qf tliQ surface of the basal knob on the male antenna.

24

BULLETIN OF THE LABORATORIES

Fig. II. Larva of Limnetes when .5 mm. long, showing withdrawal of the
hypoderm and its contents from the walls of the antennules and labrum. A, an-
tennules inside the sheath formed by their old covering. Z, labrum inside its old
shell, Zi.

Plate X.

Fig. l. Head of male, nearly adult.

Fig. 2. A typical foot of the same.

Fig. 3. One of the swimming feet of Limnetes.

Fig. 4. Outline of the head of Limnetes, after the metamorphosis, showing
relation of labrum and antennules and also the position of the beak, eye and sen-
sory fleck.

Bullelirj of the Laboratories of Denisorj University.

PLATE Y.

Bulletiij of the Laboratories of Denisoij University.

PLATE VI.

Bulletiij of the Laboratories of Denisoij University, PLATE YII,

Bullelit) of ihe Laboratories of Denisoij University.

PLATE YIII.

III.

SUPERPOSED BUDS.

Plate XII.

BY A. F. FOERSTE. ,

Buds are usually produced singly in the axils of leaves. When
more than one bud is found in the same axil, the additional buds are
accessory and supernumerary . When they are placed at the side of
the one immediately in the axil, the buds are collateral, when placed
in a line vertically above the axillary bud, the additional buds are
superposed.

Accessory buds are not of the same age. In the case of collateral
buds, the one immediately in the axil is the oldest. Among super-
posed buds there are two methods of development. The axillary bud
first produced becomes visible, grows, and may reach some size before
any additional bud is apparent. After a time • another bud appears
immediately above the one already produced. A third or fourth bud
may appear above the one last formed. In the Tartarean honey-
suckle ( 7 ) four or five buds are occasionally found arranged in such a
series above the true axillary bud. This is called direct superposition
and is of rare occurrence both among woody and herbaceous plants.

Usually, however, the axillary bud first produced reaches a consid-
erable size before a second bud appears. This second bud is inserted
beneath the one first formed. If the second grows rapidly enough, a
third bud may appear beneath the second, and a fourth beneath the
third. This is inverted superposition and is very common indeed, both
in ligneous and herbaceous plants. In several species of the Juglan-
daceae and in Gyninocladus Canadensis (6) where the buds do not im-
mediately follow one another but are arranged at short intervals along
the internode, five or six buds are occasionally found superposed in
this manner. The upper buds here betray their earlier origin by their
greater size and development.

26

BULLETIN OF THE LABORATORIES

In both direct and indirect superposition the bud first formed is the
largest, the best developed, and the one most likely to grow and to form
a branch. If several buds produce branches, those from the later
buds are successively smaller. If the largest and earliest bud dies,
the next in age takes its place and produces the branch. Insects fre-
quently cause the death of branches ; early frosts may nip the tender
shoot ; birds, squirrels and other animals frequently feed upon the buds
themselves ; in all these cases the smaller, more undeveloped buds
may come into play and be called upon to continue the life and growth
of the plant. Superposed buds are thus a provision of nature to
remedy the loss of buds or branches, however occasioned. Buds are
usually formed a short time after the tissues of the leaves have become
differentiated from the stem, and the ordinary scaly buds of ligneous
plants can be seen in a rudimentary condition almost as soon as the
leaves can be distinguished by the naked eye. By the time the leaves
are fully developed the scaly buds have also reached a stage bordering
on maturity, and this generally before the middle of summer. Be-
tween this time and autumn they undergo a slow change and indura-
tion which prepares them for winter. Superposed buds of the same
axil originate at different times, but the bud first formed develops sub-
sequently to the formation (differentiation) of the subtending leaf.
The difference in time in the appearance of the several buds is some-
times very slight, so that they seem to originate almost simultaneously.
This is true of Gymnocladiis , in which, however, the difference in size
is well marked at an early period.

Superposed buds do not appear in all the axils of a plant ; it is
even uncertain whether they can be found in all individuals of any
single species. Nor do they always appear in equal numbers. The
existence of accessory buds is a sign of vigor ; the leaf-axil does more
than the normal amount of work whenever it produces more than one
bud. The period of greatest vigor and most rapid growth is not
when the plant is small and struggling for life, but when it has reached
some size and has abundant roots. Accessory buds in herbaceous
plants are usually found, therefore, in the upper axils of the plant, and,
if more than two buds be found in any of the axils, the greatest num-
ber will be found in the most vigorous axils. But these are not the
axils last produced, because at this time of a plant’s history the flowers
are being formed, a period just proceeding the plant’s maturity and de-
cay, when there is not much need for accessory buds, unless it be to con

OF DENISON UNIVERSITY.

27

tinue the inflorescence, as in species of Lactiica and Delphinium.
Besides, at this time the rapid production of blossom and fruit seems to
exhaust the vital powers of the plant. Hence, accessory buds are
usually found in greatest abundance above the middle of herbaceous
plants, but not at the very tips of the branches.

With ligneous plants it is different. Each year’s growth may be
said to repeat the life of the tree, and the twig takes the place of the
entire herbaceous plant. The period of greatest vigor in an ash twig
is not when the sap has begun to flow and the leaves have barely seen
the sunshine, but when most of the leaves have opened out their blades
and are in full operation. It is the time when the upper part of the
twig is developing. In the ash, where the terminal bud is already
produced in June, the leaves last formed subtend accessory buds, while
those formed earlier usually subtend only the single axillary bud. In
young, vigorous shoots of hickory and walnut, the axils first formed
contain a single bud ; those towards the middle of the branch, two
buds, one of them accessory ; the axils later formed, from three to four
buds ; and in very vigorous branches the last formed axils may contain
even five buds. Many trees which usually do not form accessory
buds (Draxinus Americana) (i) produce large and well developed ones
in all the upper axils, when the tree has been cut down and the strength
of all the roots is turned to the support of a few fresh shoots growing
out from the old stump.

The term superposed hnds was introduced to explain the existing state
of things in ligneous plants, where they were first studied. Here the
buds are really placed one above the other along the internodes of the
plant, and frequently by the lengthening of the internode during the
earlier part of its growth, the buds may be considerably removed from
one another and the uppermost bud may be about an inch above the
lowest, as in the Juglandaceae. In such cases the earlier and hence
upper buds, being separated while the twigs were growing most rapidly
are further removed from each other, than the lower buds, which grew
during the less vital period of the twig’s development.*

In Aristolochia Sipho (8) this superposition is less evident, for here
the buds are arranged at about the same height in the leaf axil, so that
superposition exists only hypothetically. Although evidently super-

separation of superposed buds, caused by the varying growth of the in-
ternodes, was noted several years ago by Mr. W. B. Werthner, who first called
my attention to it. A. F. F.

28

BULLETIN OF THE LABORATORIES

posed buds are occasionally found among herbaceous plants, in the far
greater number of cases they are inserted at about the same level and
superposition can only be morphologically asserted from the evident
origin and development of the buds. Ligneous and herbaceous
plants are almost directly opposed to one another as to the character of
their superposition.

Again, while in ligneous plants the superposed buds are usually
found during their first season as buds, in herbaceous plants one or
more buds are immediately developed into branches. Since the aerial
portion of herbs in our climate is destined to decay at the approach of
autumn, and sometimes even before that season arrives, buds do not
long remain in a rudimentary and inactive state, but grow rapidly and
form branches and flowers. The first formed bud in an herb is there-
fore unusually a well developed branch before the second bud in the
same axil becomes visible to any but the careful observer. In some
plants at this period the petiole of the subtending leaf must be care-
fully removed and the lower part of the developed branch closely ex-
amined in order to find the flattened bud lying closely against it.
Some of the small buds later in the season turn into branches and even
bear flowers, but most of them will never develop unless some accident
should befall the branch already formed.

Whenever the phyllotaxy of the branch bearing superposed buds is
that of decussating pairs of leaves, the lowest pair of bracts or leaves
of each axillary member is always placed transversely to the stem and
its subtending leaf. The lowest pair of leaves or bracts are there-
fore similarly inserted in all members found in the same axil. In
members which belong to plants having a spiral arrangement of
leaves, the lowest bract or leaf in all specimens examined was placed
towards the left or right of the subtending leaf, i. e. transversely, but
not always on the same side. Members of the same axil may have
an insertion which places the first bract or leaf always on the same
side of the stem, or they may be regularly opposed to one another, or
there may be no definite arrangement whatever in this respect. The
same thing may be said about corresponding members of different
axils.

A form of superposition occurs in some herbaceous plants which
seems to occupy a middle ground between superposed and collateral
buds. In Thalictrum dioicum, for instance, the oldest bud or branch
is nearly in the axil of the subtending leaf, then by means of inverted

OF DENISON UNIVERSITY.

29

superposition follow three or four other buds or branches, not in a
straight line, but placed alternately towards the right and left of such
a line. The insertion, therefore, is similar to the arrangement of the
uniparous scorpioid cyme. But, aside of mere appearances, there is
no reason for considering them as anything but cases of superposition
in which the different members of ithe same axil have alternately been
thrown towards opposite sides. It is worthy of notice that this form
of superposition is common among certain species of Lcguminosae
{Medicago), where the ordinary forms of superposition are also abun-
dant both among herbaceous and ligneous plants.

Another form of superposition is very common in species of Solan-
aceae, where the main axis ends in a flower or inflorescence, which is cast
to one side by the first formed axillary bud. This bud grows into a
branch and continues the main axis, taking an erect position and seem-
ing to be its direct continuation. 'fhe leaf which subtends this branch
usually contains a bud which is morphologically the second-formed bud
of the axil. Eichler figures in his “ Bluethendiagramme” two of
these accessory buds in the leaf axils of Atropa Belladona.

And, finally, since flowers, thorns, tendrils, and other organs are
frequently the morphological equivalents of buds, they will often be
mentioned in speaking of superposed buds.

In the following pages an enumeration will be made of such plants
as will illustrate the general remarks made above, and any details
not hitherto mentioned will be made under the particular species when
cited. In these notes most attention will be paid to herbaceous
plants, since less attention has been given to these, and they present
some variations not noted in ligneous plants.

I. INVERTED SUPERPOSITION.

A. Of Leaf -buds and Branches.

I. Buds. — The superposition of buds, none of which have devel-
oped into branches, occurs chiefly among ligneous plants. Fraxinus
sambucifolia., F. viridis., and vigorous specimens of F. Americana ( i )
have two buds in the same axil, placed close together, the lower about
half the size of the upper. Cercis Canadensis shows two or three,
the lowest of these often minute and somewhat covered by the petiole
scar. Ptelea trifoliata (14) has also two superposed buds. In
this case they are sunk into the .wood and almost inclosed by the cres-
cent- or almost V-shaped petiole-scar, so as not to be evident. Carya

30

BULLETIN OF THE LABORATORIES

alba {2), C. sulcata^ C. totnenfosa and C. porcina^ all have the upper one
of the two superposed buds so excessively developed, that the lower
remains quite insignificant, often obsolete. C. miavcarpa and Juglans
regia have the lower buds of larger size. Robinia Pseudacacia has
two superposed buds, both of which often develop, but the upper one
outgrows the other. In this species the buds are formed beneath the
surface of the petiole scar, so as to be invisible until growth begins in
spring. Sometimes three buds in one row are seen bursting through
the scar which has encased them all winter. Menispermmn Cana-
dense (17) has also two or three buds covered by the circular petiole
scar, through which they burst in spring. Two of three buds
often develop into branches. Gymnocladus Canadensis (6), which
has buds enclosed by circular pit-holes in the bark, frequently presents
four or five of these to one axil, the lowest being reduced to a mere
dot. The upper two are always quite a distance apart — the lower
ones less so. Sanibiicus, which is usually credited with the existence
of buds inversely superposed, presents a poor case in S, Canadensis^
in which the lower buds seem to develop from the upper, and not to
be independent of it.

Various species of Rubiis also show superposed buds having the
general aspect of those of Sambucus Canadensis. In some species
which usually produce three or more buds in the same axil, the upper-
most bud is greatly developed and often supported by a basal internode
one-eighth to one-half an inch in length. Carya olivaeforniis (3)
has two or three buds, the upper two well developed and some distance
apart. The support of the upper is small, often obsolete. C. am-
ara, with two or three buds placed closer together, has a support for
the upper bud, often one-third of an inch long. In Ptero-carya
Caiicasica (15,) we find the extreme in length of the support-one-half to
three-fourths of an inch. Three buds are normally produced in the
same axil. Liviodendron Tullpifera has three buds close together,
the upper with a support often half an inch long. These species offer
a sort of transition to those in which the upper bud develops immedi-
ately into a branch.

The only case among herbs, known to me, which would prop-
erly fall under this class, is that of Dicentra Cncidlaria (9). The
grains clustered about the roots of this plant are known to be
either the bases of aborted leaves, or the true bases of the leaves
themselves. Both kinds of grains, when sufficiently developed, will

OF DENISON UNIVERSITY.

31

show, on examination, a narrow slit along their upper surface. In
this are found one or two buds, of which the one nearest the stem is
the oldest and largest. They form an interesting means of compari-
son with the specimens already noted. Like these, the buds are des-
tined to outlive the winter and begin fresh growth with the opening
spring.

2. Buds and Branches. — Species in which the uppermost su-
perposed bud immediately develops into a branch, while lower ones
remain for a longer or shorter period in the bud state, are rare among
ligneous plants, while among herbs they comprise almost all known
cases. In Cornus stolonifeixi (4), a shrub or small tree with two buds
to the axil, the upper may develop into a branch some inches long be-
fore the season closes, or it may remain only a bud. In either case
the lower bud remains small.

The first formed bud in herbs is usually a well developed branch
before the second becomes visible. The petiole must often be care-
fully removed and the lower part of the developed branch closely ex-
amined in order to find the flattened bud lying closely against it.
This in the month of July is true of Bar bar ea vulgaris^ Sisymbrium
officinale, Oenothera fruticosa, Nesaea verticillata, Ambrosia ar-
te mis iaefolia, Scrophularia nodosa, Mimuhcs ringens, Gera'rdia purpu-
rea, RiLellia ciliosa, Verbena stricta (12), Verbena urticifolia, Fhryma
leptostachya, Lycopus sinuatus, Teucrium Canadense, Chenopodium
album and many others.

Some of these smaller buds later in the season turn into branches.
Even in July Ambrosia trijida has most of its upper axils filled with
two well developed branches. In Lactuca Canadensis the younger
branch already bears flower buds ; the older branch is in blossom.
Brassica nigra has the flowers of the older branch turned into seed,
while the younger one in the same axil is flowering. In Lysimachia
ciliata, the younger branches are partly in bud, partly in flower.

As examples of plants bearing more than two buds in the same
axil, may be mentioned Chelidonium majus (10), which occasionally
has three such buds, and Thalictrum diowum, which has four or five.
In Ch. majus, the base of the leaf and node swells and forms a pulvi-
nus or cushion, extending horizontally from the stem, and supporting
the buds and branches. Since these are borne on the same horizontal
plane the term superposed is correct only theoretically. T, dioicum
will be described later.

32

BULLETIN OF THE LABORATORIES

B. Oj Inflorescences and Flowers.

I. Inflorescences. — Lippia lanceolata. — A peduncle, bearing
a head of flowers, is superposed to a tiny bud, which, however, does
not always appear. Dianthera Americana presents the same features.
Delphiniiini consolida. — Both the flowers composing the terminal ra-
cemes and the upper branches may be found late in the season super-
posed to axillary buds. The buds found along the lower parts of the
racemes, and most of those in the leaf axils generally develop and
flower before the season closes. Lythrum alatuin. — Flowers said
by Gray (Man. 183) to be solitary in the axils of the upper leaves.
Occasionally, however, they are arranged in cymes of two or three
flowers each. In this case two cymes of an equal number of flowers
may be superposed to one another ; or the lower cyme may be reduced
to two or even one flower ; single flowers are also found superposed to
one another. The place of the lowest flower may even be supplied
by a leaf branch which then grows vigorously and bears flowers in its
turn — thus a small flower may be seen superposed to a vigorous branch.
Branches in this situation occur irregularly along the flower-bearing
axes of vigorous plants. Chelidoniiim niajiis (10). — The main
stem here frequently terminates in an umbel of flowers. The bud
first produced also develops into an umbel.. The next bud may de-
velop into a leafy branch and throw the two umbels to one side and
place itself in the continuation of the stem. The last bud, if formed,
usually remains small. Cassia Chamaecrista. — The raceme of
flowers is found at some distance, sometimes half an inch, above the
axil. Within the axil is frequently found a branch which may grow
and give rise to flowers in its turn. Penthoriim sedoides. — The lower
flowering branches are found in the axils of leaves, but become more
and more raised above the axils by adnation to the stem as we ap-
])roach the top of the plants. The uppermost branches, bearing the
immediate inflorescence, all become adnate to the stem, thus forming
a single compound inflorescence, the lower members of which are
raised far above the subtending leaves, while the upper members may
be referred to the axils of some of the tiny bracts, scattered about the
common peduncle, formed by the union of the flowering branches.
Some of the last members of a large inflorescence can not be referred
to the axils of either leaves or bracts with certainty. Immediately in
the axils of the leaves, whether containing branches in the very axil or
removed to a position above it by adnation, may be found a tiny bud.

OF DENISON UNIVERSITY.

33

which never, or at least rarely, develops into a branch. JLhtdera
Benzoin (5). — This shrub may have in the same axil either two
ordinary leaf-buds, or a leaf-bud and a tiny branch, or two tiny branch-
es. These branches bear a terminal leaf-bud and one or two axil-
lary flower buds just beneath it, subtended by bracts. Juglans cinerea
and J. 7iigra produce from two to five buds in the same axil, which in
the latter species are found closer together. In older trees one or
more of these buds develop into the sterile catkins.

2. Flowers. — Since flowers are also the morphological represen-
tatives of branches, and hence of ordinary leaf-buds, a few species
may be mentioned in this connection.

A sort of intermediate condition between flowering branches and
flowers are those in which the flower peduncle bears a single leaf-like
bract. Lilium bulbiferum, to be described later, is such a case.
Aristolochia Sipho (8) is another. The latter has three or four super-
posed buds, of which the upper are the strongest. They are during
the first season almost enclosed by the base of the petiole. The upper
bud, sometimes the two upper buds, are leaf-buds, the remainder being
flower- buds. All develop during the following season. The cases
of Delphinium and Lythrufn have already been described. Lin-
dera Benzoin sometimes belongs here. Lysimachia nummularia
frequently shows small buds just beneath the flower peduncles, which,
I suppose, occasionally develop into leaf-branches. Various foreign
species of Loranthaceae are known to contain one or more vertical
rows of superposed flowers in the axil of the same bract. The flow-
ers, however, are all sessile in these cases.

C. Other Morphological Equivalents of Branches or Buds.

1. Thorns. — Gleditschia triacanthos also bears a superposed bud,
developed in this case into a many spined branch or thorn. Each
spine of this thorn is subtended by a small scale, representing a leaf.
Below in the axil of the subtending leaf may be found three or more
buds, also in superposition. The thorn is usually found removed
quite a distance from the leaf axil to which it belongs. The place of
the scale in this thorn is often supplied by the leaves themselves.

2. Bulblets. — Lilium bulbiferum. — A peduncle, bearing a
leafy bract and a flower, is here superposed to a bulblet immediately
in the leaf axil. Thi^ bulb may have accessory collateral bulblets ou
either side.

34

BULLETIN OF THE LABORATORIES

D. Irregular Superposition.

I. Sympodial Growth, — Those species of plants, especially
common among Solanaceae, in which an axillary branch continues the
stem of the plant while another bud is formed in the axil of its sub-
tending leaf, have often been made the subject of special investigation
and can be studied in books especially devoted to this subject. The
Vitaceac among ligneous plants present cases in some respects similar
to these. They are all caused by sympodial growth.

II. Zig-zag Superposition. — Scarcely any other term will express
the arrangement of the superposed branches and buds of the plants
in question. In Thalictriim dioicum the branches will be found
thrown alternately towards the right and left of a true median line.
The superposed buds, both leaf- and flower-buds, of Aristolochia
Clematitis will be found arranged in a similar manner. Atriplex

patula shows the same manner of arrangement. (See Eichler, Blue-
thendiagramme, 11. , pp. 83, 533 and 159.) Various species of Leg-
uminosae present the same or similar features. In their case the in-
terest is so much greater, on account of the ordinary forms of super-
position common to both the ligneous and herbaceous plants of this
order. Thus, for example, in Melilotus alba the buds are thrown al-
ternately towards the right or left of a true median line, and even
where only two buds are found and where crowding is not so evident
the same features still present themselves. In closely related species
of Trifoliimi^ however, the. superposition is of the ordinary kind.

II. DIRECT SUPERPOSITION.

Lonicera Tartarica (7). Two to five buds are here superposed.
The one directly in the axil is formed first, and those above at success-
ively later periods. The lowest bud is the strongest and generally
produces the branch, but occasionally several of them develop. Among
flowering branches, the lowest buds produce the flowers, or flower-
clusters. Coreopsis tmctoria (16). — The upper leaf axils contain a
flowering branch, superposed to which is a small bud which later in the
season produces two or three leaves and a flower. C. tripteris has
larger and more developed superposed buds, the upper of which bears
leaves and two or three flowers. The superposed branch is inserted,
as in the first, directly between the axillary branch and the stem.
Fassiflora lutea. — Immediately in the axil is a tendril which represents

OF DENISON UNIVERSITY.

35

the first bud. At either side of the tendril, representing its branches,
.is a flower. Above the tendril is found a bud, the undeveloped su-
perposed branch.

(In a curious specimen of Ulnius fulva (n), found near Dayton,
there were two leaf scars, the places of attachment of two leaves,
which supported but one bud, the normal arrangement of the remain-
der of the branch being otherwise preserved. )

EXPLANATION OF PLATES.

Plate XII

Superposed Buds In —

Fig. I. Fraxinus Americana, L., from a one year old shoot growing out of
the stump of a tree cut down during the previous year.

Fig. 2. Cary a alba, Nutt., the tip of a branch.

• Fig. 3. Cary a olivaeformis, Nutt., section of a node taken from the upper
part of a twig.

Fig. 4. Cornus stolonifera, Michx., A, section of a node showing the con-
tents of only one leaf axil. Twig collected in autumn, showing one of the su-
perposed buds partly developed. B, diagram of buds as they appear in less
vigorous axils.

Fig. 5. Lindera Benzoin, Meisn., superposed branches composed in each
case of a terminal leaf-bud, and two lateral flower-buds.

Fig. 6. Gymnocladus Canadensis, Lam., buds enclosed in pit-holes.

Fig. 7. Lonicera Tartarica, L.

Fig. 8. Aristolochia Sipho, D Her., a regular leaf-branch represents the first
formed bud of last year ; the flower, the second bud. B, diagramatic section,
showing the buds still undeveloped.

Fig. 9. Dicentra Cucullaria, DC., A, section of a grain. B, slightly en-
larged portion of the same, both sections magnified.

Fig. 10. Chelidonium majus, L., A, the main axis is here turned into an
umbel of flowers, the first developed bud is in the same case, the second bud is a
leaf-branch, the third is still in the bud state. B and C, diagrams showing the
relative insertion of branches and leaves. D, a case of superposition with two of
the buds developed into leaf-branches.

Fig. II. ( Ulmus fulva, Michx. , a freak of nature, two leaves subtending one
bud.)

Fig. 12. By mistake marked 2 in the lower part of the plate. Verbena
stricta, Vent.

36

BULLETIN OF THE LABORATORIES

Fig. 13. Ambrosia artemisiaefolia., Z., the first bud has here developed into a
leaf-branch ; the second, into an inflorescence.

Fig, I4. Ptelea trifoliata., Z., A, a case of “ Uebergiphelung”. B, enlarged
section of a node of the same twig.

Fig. 15. Ptero-carya Caucasica.

Fig. 16. Coreopsis tinctoria., Nutt., the first bud developed into a flowering
branch ; the second, into a flower bud.

Fig. 17. Menispermum Canadense, Z., three buds bursting through the peti-
ole scar.

I, II, III, &c., the first, second, third, &c. oldest buds or their equiva-
lents; ps, the petiole scar; If, the petioles of leaves; S, stems of leaf-branches;
F, stems of flowering branches or peduncles of inflorescences. Figures are cited
in the text by their numbers.

Bulletitj of the Laboratories of Denisorj University.

PLATE XII.

IV.

MUD-INHABITING CRUSTACEA.

Plate IX.

Among the curiosities of pond life are certain minute crustaceans
which spend their entire life in the soft debris and mud forming the
superficial deposit at the bottom. The Canthocarnptus among cope-
pods is commonly found in such situations, but this is less surprising
than that members of the cladocera, or shelled entomostraca, with their
delicate organization and frail structure should have become adapted
to such a life. In many marine crustaceans (copepoda) the accomo-
dation to such a reclusive life is manifested in the retrograde devel-
opment of many of the organs — eyes, even, being absent in several
cases. The present paper is concerned only with a few cladocera,
which are peculiar to America or rare both here and elsewhere, and
which exhibit curious and instructive modifications as a result of such
a habitat. The reader who wishes to familiarize himself with the sys-
tematic classification of the group would do well to consult Die Clado-
ceren Boehmens^ by Hellich, Birge’s Notes on Cladocera, and the
writer’s Final Report 07t Crustacea of Minnesota, while, for a thor-
ough study of the physiology, Weisman’s Beitraege zur Naturgeschiclite
der Daphnoideii, is necessary. A special paper on the limicole or
mud-loving cladocera was published in the Zeitschrift fuer Wissenchaft-
liche Zoologie, in 1878, by Dr. Win. Kurz, and entitled Ueher limi-
cole cladoceven. Reference will be frequently made to this paper and
this must be understood in all cases of reference to Kurz, unless other-
wise specified. These mud-dwellers are happily called schniutz-pe-
terchen^^ cladocera, i. e. ‘‘Smut-Johnny,” or chimney-sweep water
fleas. In America the following species are pre-eminently worthy of
the name : Mofiospilus tenuirostris, Leydigia quadrangidaris, Alona
sanguinea, Alona quadra7igula, Pleuroxus procm'vus, and several other
members of the genera Alona and Pleuroxus. The typical cladocera

38

BULLETIN OF THE LABORATORIES

are graceful in movements and slender in form. Very generally they
are more or less boat-shaped and the polished shell is modeled like a
clipper, the head-shield forming the prow, while, in a few cases of the
best swimmers, (as Carnptocercus^ Acroperus^ and Alonopsis) there
is developed a sharp ridge upon the back which bears an unmistakable
resemblance to the keel of a boat and, since the animals swim upon
the back, may not impossibly serve a similar purpose.

In the mud-loving species, on the contrary, the body is clumsy and
approaches the spheroid in form, the antennae, which normally are oar-
like and long, bearing fringed setae, are short and are armed with claw-
like spines and smooth setae. The post-abdomen or tail, which in the
natatory species is reduced in size and subordinated in function, is here
enlarged and armed with numerous and considerable spines. The
front of the head is either reduced and pointed, or, if there be a long
beak, it is turned up out of the way. The meaning of all this is that
the animal no longer swims on its back, but creeps humbly and prone
and requires the efforts of post-abdomen and antennae, as pushing poles
to make its way through the debris in seach of food. The effect of
this manner of life is seen in several other ways, as in the structure of
the shell itself. In several of our species the shell, which is renewed
periodically, is not, as in other cladocera, moulted, but remains as a
sort of outgrown overcoat, after the new shell has become perfected.

The result of this is what might be expected from the sluggish na-
ture of the animal, the supply of clothing thus accumulated becomes
so onerous a burden that it no longer could swim if it desired and is
thus fettered to the life it early chose. While this is true of a few
only, yet in all the limicole cladocera the cuticle becomes indurated
and it follows that respiration, which normally takes place from the en-
tire surface of the body, becomes restricted to those membranes in
contact with the water within the valves of the shell. As a partial
offset to this disadvantage, the strictly respiratory appendages on the
feet are enlarged more than in most groups. The sensory organs are
modified in several ways. Kurz calls attention to the fact that the
antennules are movably joined to the body in the limicole cladocera ;
they are also, as a rule, rather large and well endowed with sensory
apparatus. The compound eye is small and, in one species, as we
shall see, fails to develop at all.

Monospilus dispar, Sars. is the most remarkable of all filth-dwel-
lers. This animal may probably lay claim to be called the rarest of

OF DENISON UNIVERSITY.

39

the family and has been seen but few times. First described and
figured by Fischer, from Russia, it next turns up in Scandinavia, where
Sars gives a full Latin description. Norman and Brady find it in
England, and Mueller in Denmark, and, finally, Hellich records it in
Bohemia. It was also reported from Minnesota, by the writer,
in 1884.

Unlike most other limicole cladocera, the body is narrow and high,
rather than globose, the head is much depressed and terminates in a
slender rounded beak, like the bill of a duck. The fornices or free
margins of the head-shield are narrow and flaring. The shell of an
old individual is a curious pile of overlapping valves, and is ornament-
ed with concentric series of depressions. The lower margin is nearly
straight and bears a row of long curved teeth (not free spines), back
of which are two small teeth. The antennae are short and the an-
tennules rather slender. In this respect our specimen seemed to dis-
agree with the figure given by Hellich. The labrum is of large size
and is produced into an acute appendage below, as in most Lynceids.
The compound eye is quite absent, but its function is subserved by the
larval organ, a quadrate and rather large fleck at the base of the an-
tennules. The intestine is coiled once and one-half times and opens
in about the middle of the flat, pentagonal post-abdomen. The latter
bears straight terminal claws, each with a single basal spine, a series of
rather small triangular teeth, posteriorly, and irregular areas of fine
spines upon the sides. The male is not known and many points of
interest remain to be made out.

The two species of Leydigia^ both of which occur in America, are
familiar enough and are sufficiently well described to render a repeti-
tion of the description needless. It is otherwise with the only species
of llyocriptus yet found in America.

Ilyocryptus setifer, Herrick. — The description given in my
“Final Report, etc.,” is very brief and no comparisons were there
instituted with the I. agilis of Kurz which is its nearest ally in
Europe. The paper by Kurz referred to gives detailed descriptions of
the three European species accompanied by elegant plates. We are
able, therefore, to draw up the following distinctive diagnosis of the
species, hoping thereby and by means of the figures to show the rela-
tions of the four species at present known. It is almost certain that
we have more than one species in America and the careful description
of the known form may make the detection of others easier.

40

BULLETIN OF THE LABORATORIES

The size varies greatly, a full grown female with eggs in the brood
cavity is nearly .90 mm. long and .70 high, while a smaller female
measures .65 mm. long by .44 high. The form of the shell is nearest
like that of I. acutifrons, the heighth being less than in /. sordidus,
and the angle between the ventral and posterior margins less than in
1. agilis. The entire length of the post-abdomen in the large female
is .56 mm. measured to the base of the caudal stylets, of which length
.168 mm. pertains to the claws. The width of the post- abdomen is
but. 14 mm. Thus it is evident that the proportions of the post-
abdomen differ greatly from any of the other species, it being very long
and narrow. The terminal claws are exactly as in /. agilis^ having
two small basal spines and a few sharp serrations near the apex, an-
teriorly. Near the base of the claw is a cluster of small spines of
two sizes, then begins a series of about sixteen lateral teeth averaging
.02 mm. in length and extending to the sides of the anus. Above
this point the contour of the margin is convex and is ornamented with
nine spines twice as long as the preceeding. Then follow the promi-
nences which bear the long and simple caudal setae. Besides the
above mentioned spines there are four spines on either side upon the
lower posterior angle of the post-abdomen which are four times as long
as those of the previously mentioned continuous series (/. e. . 08 mm. )
Above, the abdomen is hirsute or thorny as in /. agilis^ and the process
for closing the brood sac is similar. It will be seen that the post-
abdomen differs in armature as much as in form from other species.
From I. sordidus it differs in the following points : — the claws are not
pectinate behind but are serrate in front, the anal opening is higher
and the details of the spines vary ; from /. acutifrons it differs in that
the claws are not pectinate, neither is there a spine in front of the claws,
and the anus is not terminal ; from I. agilis it differs, in that the shape
is different, there are fewer enlarged spines, and the shape of the nine
spines above the anus is different. The head is convex, resembling
/. so7'didiis most nearly, but the antennules are much longer and more
slender than in any other known species. They are .17 long and about
.016 mm. wide, while the longest seta is .084 long. The antennae are
almost exactly as in /. so7'didiis. The labrum has the usual shape, as
have the jaws and other appendages. The margins of the shell are
ornamented with spines simply pectinate or barbed, as in /. agilis. In
/. sordidus these spines are variously branched and in that form alone
of the European species, according to Kurz, is there a failure to per-

OF ’DENISON UNIVERSITY.

41

feet the moult; in our species, which has simply pectinate setae, the old
coverings are all but uniformly retained. The spines of the lower
posterior margin are from .16 mm. to .20 mm. long.

Such are some of the chief peculiarities of the species, but, to make
the relation between the four species of this little-known genus even
clearer, if possible, the following comparative table is appended.

The shell moulted periodically —

/ /. agilis.

\ I. acutifrons.

The shell not moulted but retained —

J /. sordidus.

\ I. spinifer.

Antenules not more than eight times as long as broad—

f /. sordidus.

J /. agilis.

( I. acutifrons.

Antenules more than eight times as long as broad —

I. spinifer.

Claw of post. abdomen pectinate —

( /. sordidus .

\ /. acutifrons.

Claw of post-abdomen not pectinate —

/ I. agilis.

\ I. spinifer.

A strong spine in front of claw —

1. acutifrons.
f I. sordidus.

Fine bristles or none in front of claw

■< I. agilis.

( I. spinifer.

Anus opening near the claws —

I. acutifrons.
f I. sordidus.

Anus about midway of the posterior border —

J I. agilis.

( /. spinifer.

Marginal spines of shell much branched —

I. sordidus.

C I. agilis.

Marginal spines nowhere much branched —

) I. acutifrons.

( I. spinifer.

Elongated anal spines on either side, four or five, very long —

I. spinifer.
f I. agilis.

Elongated anal spines more numerous —

I. acutifrons .
f /. sordidus.

Upper Jone to three) spines of the supra-anal series modified
and enlarged —

Upper spines like the others —

J/. acutifrons.

\l. agilis.

{/. sordidus.

(P. spinifer.

42

BULLETIN OF THE LABORATORIES

Plate IX.

Fig. I, Ilyocryptiis spinifer. Her., female.

Fig. 2. Post-abdomen of same.

Fig. 3. Antenule of same.

Fzg. 4 A. Jaw of I. sordidns.

Fig. 4. Post-abdomen of same.

Fig. 5. Post-abdomen of I. agilis.

Fig. 6. Head of same, antennae being removed.

Fig. 7. Antenule of /. sordidiis.

Fig. 8. Spines on edge of shell of same.

Fig. 9. Post-abdomen of I. aciiiifrons.

Fig. 10. Monospilus dispar, female.

C.Z.

Plate IX,

V.

NOTES ON AMERICAN ROTIFERS.

BY C. L. HERRICK. .

\Plates II — IV^ and Plate H.]

Introduction. — -In the series of papers here begun, it is expected to
treat the subject in somewhat the following order : First, in an intro-

ductory section, an outline of the general characteristics will be given,
then we shall proceed to a description of species without attempting to
treat them in systematic order, finally, if permitted, space may be de-
voted to a review of the classification and a more detailed discussion
of anatomy and development. The present installment attempts
simply to describe a few of the common species of a number of
genera.

A rotifer may be described as a worm-like, bilateral, metazoan,
moving by means of a circum-oral trochal disc, and either adherent or
free-swimming. Many of the animals of this group are exceedingly
small and are greatly exceeded in size by certain Infusoria, and it was
this circumstance, as well as a certain outward similarity in appearance,
which led Ehrenberg to include both under the one head and to as-
cribe to Infusoria the same complicated structure he was able to make
out in rotifers. Living in all fresh waters, these animals are among
the most accessible objects for the microscope, yet, on account of the
care necessary in their study and the scattered literature, they have
been much neglected in America.

The body of all rotifers exhibits a tendency to segmentation, which
is, however, mainly confined to the integument. The inner organs
are but slightly affected by the jointing, except the muscular system
which is, moreover, largely responsible for the number and arrange-
ment of the segments. Very generally the body terminates posteri-

44

BULLETIN OF THE LABORATORIES

orly in a several-jointed abdomen or “foot,” which bears two caudal
stylets and contains glands which secrete a gummy fluid used by the
animal in temporarily adhering to other objects. The form varies
from nearly spherical or round lense-shaped to terete and extended.
The cuticle is modifided in various ways, sometimes appearing like a
bivalve shell and thus hightening the resemblance to certain entomos-
traca and explaining why older naturalists classed the rotifers under
Crustacea. The cuticle may be smooth or beautifully ornamented and
produced into long spines or marked off into areas outlined by im-
pressed or raised lines. The cuticle is secreted by a hypodermic layer
which is often seen obviously to consist of cellular tissue. Notwith-
standing the protection afforded by a chitinous shell, some species
(as Melicerta ringens) build for themselves a tube composed of ma-
terials gathered from the water and apparently connected by a cement
secreted in a gland near the mouth. Such an envelope may be com-
pared to those swallows’ nests eaten in Asia, or the case of a caddis-fly.
Some of the species live in colonies, and when the colony is spherical,
as in Coitochilus, it is a veritable microcosm — a sphere of active, vora-
cious creatures whirling through aqueous space. In only one case is
it certainly known that a moult takes place, and facts seem to be un-
harmonizable with the theory that such a change of coats is affected.

The cilia of the trochal disc or “wheel” are arranged in the
greatest variety of ways in different genera. The attempt is made to
refer all these forms back to a fundamental form — i. e. a double circlet
of cilia, the outer of which is largest and serves as locomotory, while
the inner set is under the control of voluntary nerves and serves simply
to bring food within the pharynx. In many cases there is really no
indication of such a distribution and the cilia seem to be merely iso-
lated clusters of hairs scattered about the oral end of the body.
Several of the rotifers are parasitic and cling to the less exposed parts
of the body of certain Amphipods, or on Annelides, or are endopara-
sitic. The muscles are often very conspicuous and, when large, show
the striated structure well. The alimentary canal, maxtax, and the
contractile water vessel have muscular tissue af another sort.

The nervous system is most difflcult to study and little is certainly
known of its structure. Usually there can be made out a considera-
ble granular mass over the maxtax and in close proximity to 'the eyes,
this is assumed to be the principal ganglion. From the chief or cen-
tral ganglion fine nerves pass to the muscle and organs of sense.

OF DENISON UNIVERSITY.

45

The eyes are double or single and are sometimes supplied with a
lense ; they are always furnished with a dark red pigment and, very
generally, rest directly upon the ganglion. There are occelli at vari-
ous points in the trochal disc of some species. The sense of touch
is delicate, and there is often a special tactile tentacle, or palpus with
minute tactile rods. This may be reduced to a slight papilla or a pit,
with sensory hairs. No other sensory organs have been discovered, al-
though Huxley fancies that to be an octocyst, which the Germans call the
Kalk-beutel,” i. e. the lime-sac. This is a spheroidal sac, contain-
ing irregular grains of lime. The function is unknown, but it may
be simply a reserve supply to be used in preserving the rigidity of the
indurated parts of the body.

The mouth is more or less ventral, while the anus is dorsal. The
mouth leads by the pharynx into a roomy and expansible crop or
directly into the maxtax or masticatory organ, and this is armed with
chitinous appendages of the most various form, but referable to a sim-
ple type. Here there is a central anvil-like part called the incus and
two lateral mallei which consist of a handle (or manubriimi) and a
head {uncus) which beats upon the incus and reduces the hard parts
of the food. The maxtax opens into a narrow ciliated oesophagus
which, in turn, leads to the stomach proper.

The stomach is sometimes quite distinct from the succeeding parts
of the ^system, but sometimes can only be distinguished by the large
size and absorbtive character of its cells. Into the stomach is poured
the secretion of a pair of glands which may be compared to the so-
called salivary glands of insects or the liver and salivary glands of ver-
tebrates. The size of the glands is dependent on the diet of the ani-
mal. In carnivorous species the glands are small, while in others
they become quite conspicuous. The intestine is clothed with long
cilia and opens into the cloaca or common receptacle of the reproduc-
tive, water vascular, and alimentary systems. In some species, how-
ever, the stomach is a coecum and has no anus. Males uniformly
lack the alimentary system and are short-lived creatures of love. In
some cases evident messentaries support the digestive tract.

The excretory system consists of a pulsating bladder, opening into
the cloaca, and two lateral vessels of various form, upon which are
flagellate chambers which contribute to keep up a circulation between
the cavity of the body and this vascular system.

Respiratory and circulatory organs, in the received sense, are absent,

46

BULLETIN OF THE LABORATORIES

respiration taking place, as in many small entomostraca, through the
body surface, and circulation is affected by the rythmical movements
of the digestive tube and the ciliary action in the later vessels.

In mature females much of the body cavity is filled by the ovary
and the yolk masses or eggs. The ovary is disc-shaped, botryoidal
or variously contoured and in the grey substance exhibits hyaline spots
containing the nucleated ovule cells. A part of the ovary temporari-
ly secretes the yolk when the egg reaches maturity, so that the appear-
ance of the viscera differs greatly at different times. The egg, after
extrusion, is commonly carried about in a delicate external brood-sac
as in copepoda.

To add here the details of the development of the egg would lead
us too far. The male, as before said, has no functional digestive tract
and is not only much smaller than the female, but suffers a reduction in
many organs. The sensory organs are, however, well developed. The
testis is spindle-shaped or oval and opens in a papilla, which also con-
tains the opening of the water chamber or pulsating vessel. The
spermatozoa are rod-like or thread-like and motile.

The Rotifera are found in fresh and salt water over the entire globe.
Some species may be found in damp situations on land. They exceed
even the lower Crustacea in their great adaptability to changes in out-
ward surroundings. Not only is drought not destructive to the eggs,
but the animal itself endures a long period of dissication. Other
notes upon the habits must find their place under the special descrip-
tions.

Descriptive Part. — As above stated, the following descriptions are
given without attempt at orderly arrangement, with the expectation of
ultimately attempting a systematic review. In cases where lack of
literary aids make positive identification impossible, the description
alone will be given, awaiting future identification.

CxENUS FLOSCULARIA, Oken.

The head is margined by five oval processes bearing exceedingly long setae of
excessive fineness. The mouth is central, with a funnel-form opening. There is
a crop-like vestibule, separated by a partition from the phaiynx, except in the cen-
tre, which is perforate, the opening being margined by several pendulous cilia.
The adult is attached by a long, jointed foot, but the young is motile and possesses
eyes, which are aborted after the metamorphosis.

OF DENISON UNIVERSITY.

47

Floscularia ornata, Ehr.

is not a rare inhabitant of the pools of Minnesota. The very full de-
scriptions of this species, given by various authors, would seem to have
exhausted the subject, but we do not even yet feel sure that the so-
called species are not local or age variations. The other species are
F. appendiculata^ F. proboscidea^ F. complanata^ F. longiloba, and F.
trifoliiim.

Of Rotifer and Callidina we find a number of species, but reserve
the consideration of the group for another occasion.

Notoinmata furnishes several species which are very abundant and
striking, but a large number of works are necessary for their study.

GENUS EUCHLANIS, Ehr.

The lorica is oval and composed of an arched dorsal shield and a plane ven-
tral one. The lorica in front is broad and presents a large opening for the head.
The shell often has a carina above, while the dorsal shield is movable upon the
ventral. The trochal disc is strongly ciliate and bears two terminal sensory or-
gans with clumps of tactile hairs. There is a single cervical eye and the viscera
are highly differentiated. The foot has four short segments and two terminal
lanceolate claws.

Euchlanis (dilatata) hipposideros, Gosse.

Septate ///, Fig. 2.]

The identification of our species with the above is made in spite of
minor points of disagreement which may be looked upon as the result
of faults in the descriptions or slight variations in structure. Eckstein
gives the length at .45 mm., while Eyferth says .23 mm. Our spe-
cies varies only between .22 and .24 mm. and is quite uniform, so far
as observed. The form is oval, the lorica being excavated before and
behind, as shown in the figure, although it is not often seen as clearly
as drawn.

The trochal disc has two broken circlets of cilia, and on either side
the head is a pit densely ciliated within. The drawing given by Eck-
stein shows the arrangement well. Two curious sensory organs oc-
cupy the very front of the head. The ganglion is very large and
quadrate, the eye being near its anterior part and quite large. The
maxtax is quadrate, showing the component parts well. The stomach
is ob-pyriform and there are two accessory glands. The ovary has
very large nuclei and the egg is of great si^e. The contractile vessel

48

BULLETIN OF THE LABORATORIES

is clearly seen and all the details of the water vascular system may be
made out with ease. The lateral vessels are tortuous canals, while
upon them are seated beaker cells, the flask-shaped base of which, con-
nects directly, by means of a curved tube of less diameter, with the
main canal. The mouth of the flask is directed downwards and
has a small opening near which is the point of insertion of a long
cilium which extends upward into the flask, where it is constantly in
motion. There seems to be no reason to doubt that by means of
these beaker-cells the vascular system is in communication with the
perivisceral cavity. The foot is comparatively slender and has, aside
from distinctly cross-striate muscles, two large foot glands which open
in the ends of the rather long dagger-shaped claws. A pair of fine
bristles springs from the dorsal surface of the last segment of the foot.

The following measurements were taken ;

I. lorica .22

mm.

long.

No. 2. .22 No. 3.

.24

“ .14

mm.

wide.

.14

•15

foot .06

mm.

long.

.06

claws .07

mm.

long.

.07

.072

jaw capsule .06

mm.

long.

.06

.048

Found in Minnesota during the whole summer among water plants.

Euchlanis -ampuliformis, sp. n.

[Plate 77, Fig. 3.]

This species, which deviates toward Salpina, is smaller than the
above and, in outline, 'is somewhat flask-shaped. The back is cari-
nate and the flat ventral j^late is excavated posteriorly with a cordate
opening. The head is produced and densely hairy below. The
maxtax is small, but the cervical eye is very large. The nuclei of the
ovary are very conspicuous, although the egg is not as large in propor-
tion as in the above. The foot is four-jointed and the claws are elon-
gated and somewhat curved. The lorica is .16 mm. long, the claws
.08 mm. Another individual measured .20 mm. and the claws were
.12 mm. long. This species was seen but twice, June i8th, 1884,
in Minnesota.

POLYARTHRAEA.

The family includes the two genera, Triarthra and Polyarthra. In both
genera the foot is wanting and appendages of the sides of the body take its place.
The body is not segmented except anteriorly and the form is not definite. The
genus first mentioned has two lateral and a ventral appendage, while in Polyarthra
the appendages are collected in groups upon the opposite sides. In both genera,
the egg is carried about as in Amirecs^

OF DENISON UNIVERSITY.

49

GENUS POLYARTHRA, Ehr.

A single species has so far been encountered and I am able, with
the works at hand, to discover no reason to doubt its identity with P.
platyptera of Ehrenberg.

When swimming freely this animal seems to consist of two quad-
rilateral segments, the first, or head segment being considerable shorter
than wide in outline, while the body is a third longer than wide. The
trochal ciliation is slight. Two sensory organs are conspicuous upon
the front of the head and the eye occupies the middle of the first
segment near its posterior margin. The maxtax is very large and the
stomach is short, with a tubular intestine. There are two prominences
on either side of the body near the front, each bearing three lanceolate
spines. The egg is very large and is perhaps half as bulky as the
whole body. The contractile vessel is small and little could be seen
of the lateral vessels. The length is .10 mm. ; width, .08 mm, ; setae,
.088 mm. long. This species seems rare and was found among plauts
in standing water during June and July of 1884 and 1885 near Min-
neapolis.

The group of genera termed Macrodactylea or Longiseta includes
such animals as have a more or less elongate and frequently cylindrical
body, often strongly curved, and possess the following characters.
The cuticle is considerably indurated; the terminal segment of the foot
is long ; there is usually a lack of symmetry exhibited by the claws or
maxtax; and the cilia are sparse upon the trochal disc.

The following genera are at present included in the family :

Scaridium, Mojtura, Furadaria^ Disteinma^ AIonocerca,Mastigo-
cerca, Diurella^ Heterognathus ^ Rattulus.

GENUS DIURELLA, Bory de St. V.

The body is more or less perfectly cylindrical, and curved either ventrally or
dorsally. The claws are rather long and frequently seem united, and are curved
ventrally. The eye is cervical and single. There is a sensory tube upon the
upper (dorsal) part of the disc. Three species are described, although doubt ex-
ists as to the specific value of one of these; they are D. tigris, Ehr., D. Rattulus^
Eyferth, and D. stylata, Eyferth, to which a species is added below under the name
D. insignis. The common species in America is

Diurella TIGRIS, {EJiv. ) Bory.

The descriptions and figures of European authors vary remarkably
in this instance, but from them ah we are able to gather sufficient tO

50

BULLETIN OF THE LABORATORIES

make it reasonably sure that our species is really D. Tigris. It is
quite variable in size and form. The cylindrical body is strongly
curved ventrally. The head is distinctly set off from the body by a
suture as represented by Eyferth but not by Eckstein. The sides of
the neck extend into a sharp spine on either side, which, however, may
be easily overlooked. There is a sensory cylinder which forms a third
prominence upon the front. The foot consists of but a single evident
segment which is quite short. The appendages assume a variety of
appearances. Usually they seem to form a flattened triangular plate
curved in the same plane as the body. This appearance is figured by
Eckstein, though he describes the appendages as consisting of two pairs,
the outer half as long as the inner, both being united at the tips into
one plate. Eyferth says, on the other hand, that the foot bears two
unequal, bristle-like, curved claws, but his drawing shows two equal
claws. Our experience confirms Eyferth’s account. Like Rattulus,
this species moves in circles or arcs of circles when lashing its tail, but
has the power of moving in a straight line by the use of the cilia alone.
The maxtax is nearly as drawn by Eckstein. The chief organs are
two anchor -like indurated processes which are unlike in length and
form. The walls of the maxtax are furnished with ring-muscles.
The stomach is glandular and its cells contain large globules of fatty
matter. The intestine is pear-shaped and furnished with numer-
ous cilia. The contracting vessel is large but the lateral vessels
are not easily seen and I can add no details. The single cervical eye
is large and seated on a large elongate ganglion. The ovary is small
and the egg, when present, occupies the left side of the body on its
ventral aspect. The total length is about .20 mm. of which the body
forms .16 mm. The longer claw measures, in large specimens, .048
mm. and the shorter only .036 mm. Sometimes I fancied that I saw
two lateral spines as described by Eckstein. The width of the lorica
is about .65 mm. This species was encountered in Ohio and Minne-
sota in all situations and seasons.

Diurella insignis, sp. n.

[Plate 1 V. Fig. 6. )

A larger species than the above is found in Minnesota. The
length, exclusive of the claws, is from .17 to .20 mm. The claws
are .06 mm. long, one being much longer than the other. There are
spines in the cervical region sim.ilar to those described in in the above,

OF DENISON UNIVERSITY.

51

The body is much more slender, while the viscera do not differ essen-
tially from D. tigris.

GENUS MONOCERCA, Ehr.

This genus includes elongated, nearly cylindrical or conical forms, having a
single greatly elongated claw and more or fewer accessory spines on the last seg-
ment of the foot, The maxtax is elongate, with unequal indurated ridges. The
stomach is oval and the intestine cylindrical.

The only specimens of this genus as yet seen resemble very closely
M. rattus of Ehrenberg but are somewhat longer. The lorica is .30
mm. long while the claw is .22 mm. The foot consists of two seg-
ments, both of which are very short, while the last carries four or more
unequal spines. The pulsating vessel is elongate oval but the details
were not studied. This rotifer it quite rare.

GENUS DINOCHARIS, Ehr.

The lorica is cylindrical or prismatic, with a wide opening in front. The
head is distinct and feebly ciliated. The eye is cervical. The foot is long, rigid,
and three jointed. The claws are long and the foot bears, beside these, long
spines anteriorly and behind. The whole shell is densely covered with granula-
tions or spinules. *

Dinocharis Pocillum, Ehr.

(Plate II. Fig. I.)

The most abundant form of this genus in America varies so greatly
in both size and details of structure that one is tempted to identify it
with the most frequent species of Europe in spite of variations from
the descriptions of authors. The outline of the lorica is cup-shape
and its symmetry is broken by two ridges near the posterior edge, pass-
ing transversely. It is i 1-5 times as long as wide. The first segment
of the foot is short and bears two long curved spines above. The
middle joint is twice as long and nearly cylindrical. The third seg-
ment is about as long as the first and bears two curved claws four
times as long as the segment and also a short spine about as long as
the segment.

The whole body is about . 24 mm long, including the claws, which
measure . 08 mm. The eye is large and is seated on an ovoid ganglion.
The ovary is large and the nuclei are quite distinct. The egg is
obliquely placed and nearly as long as the width of the lorica. Two
curved elliptical glands lie in front of the stomach. The lateral ves-
sels of the vascular system are large. Encountered only in Minnesota.

52

BULLETIN OF THE LABORATORIES

A somewhat larger form, also found in Minnesota, has more slender
claws and seems to lack the spine on the last joint of the foot. The
shape is otherwise the same.

The cast-off shell of still a different form, in which there is an in-
dication of segmentation near the anterior of the lorica,was once seen.

GENUS SALPINA, Ehr.

Somewhat resembling Euchlanis, but having spines upon the front and posterior
margins of the laterally compressed lorica. There is a median area above, which
is less perfectly indurated than the sides, giving rise to two ridges. The foot is
short, three-jointed, and bears two lanceolate claws. The eye is single and the
ciliation of the trochal disc rather strong. The maxtax is large and the digestive
tract well differentiated. Water- vascular system with two or three beaker-cells on
either side. The egg is carried about with the parent after oxtrusion.

Salpina affinis, sp. n.

(Plate II. , Pig. 4-)

This species is so allied to S. muc7'onata^ Ehr. that it is with some
hesitation that a new name is proposed. While agreeing in most
characters, it differs from that species in having the upper pair of
anterior spines much longer than the lower and curved downward and
in having the lower pair of posterior spines much longer than the
single upper one and curved upward. S. nmcronata is said to
measure but .15 to .16 mm., while our form is .22 to .24 mm. long and
.10 mm. wide. The anterior spines measure .045, length of claws, .06
mm. The whole shell is granulated and there is a band in front, set
off by a distinct line. There is a sensory tube which bears a bundle
of cilia at its end, and which usually projects from between the two
dorsal spines of the lorica. The eye is lunate and seated on a very
large, almost spherical ganglion. The maxtax is very large and opens
into a slender oesophagus. The stomach is glandular and saccate.
The very large egg is ventral. No careful study was made of the
viscera. Minneapolis, May.

The species of the genus, aside from those mentioned, are S.
spinigera, Ehr., S. brevispina., Ehr., S. ventralis, Ehr., S. bica7'inata.,
Ehr, S. redunca., Ehr., S. dentatus., Duj., and S. polyodonta^ Schm.
There is reason to suppose that several of these are but varietal forms.

OF DENISON UNIVERSITY.

53

GENUS MONOSTYLA, Ehr.

Shell depressed, oval ; head opening large, notched before and behind. The
foot has two short basal segments and a long terminal one ending in a small spine,
hence appearing as though bearing one long spine. The eye is single and situ-
ated at the base of a large ganglion. The maxtax is large and quadrate. The
viscera are simple.

Monostyla (quadridentata, Ehr. ?)

Two species of Monostyla have been thus far encountered, one of '
which may be identical with M. quadridentata of Ehrenberg. The
body is bell-shaped or inverted pear-shaped, the oral margin being
produced into two sickle-shaped spines turned outward, which are dis-
tinct from the acute margins of the shell itself. The body is com-
posed of two segments or apparent segments, the second being small
and conical. The terminal joint of the foot is slender and elongate,
bearing a thorn-like spine. The ganglion is very large. The maxtax
is also large and opens into a sack-like alimentary canal not evidently
subdividedi The shell in this species is ornamented with granules.
Length of lorica, .15 mm., width, .11 mm., terminal caudal joint, with
spine, .08 mm. Found in June, in Minnesota.

A second species is smaller, measuring from .11 to .12 mm., foot
.04 to .08 mm., width, .11 mm. The shell is smooth and the curved
spines are absent.

The following species are known : —

Monostyla lunar is ^ Ehr., M. cornuta., Ehr., M, closterocerca^
Schm., M. oophthalma., Schm., and M. macrognatha, Schm.

GENUS DISTYLA, Eckstein.

Shell ovate conical, closed behind, except for the small opening admitting the
foot. In front, the opening is wide and guarded on either side by projecting an-
gles. The foot is one-jointed and bears two equal, divaricated spines. The
shell may be smooth or ornamented with raised lines and serrations. The eye is
single and seated upon a considerable ganglion. Two species are described by
Eckstein from Europe (jD, gissensis and D. ludwigii) and two additional ones occur
in America.

Distyla minnesotensis, sp. n.

This is a large species, .25 mm. long, with a pear-shaped body of
two segments, the first being .20 mm. long and of equal width. The
second segment is .05 mm. long and has an oval slit behind for the in-
sertion of the foot and permitting its free lateral motion. The claws

54

BULLETIN OF THE LABORATORIES

are . 13 long and slender, the terminal third being attenuated. The
ganglion is small and bears a single red eye. The trochal disc is
retracted by four powerful muscular bands. The stomach is globular
and glandular.. The short segment of the foot is moved by pairs of
evident muscles. This species was but once seen in July.

Distyla ohioensis, sp. n.

The lorica is .12 mm. long and its form is much as in the previous
species. Width of lorica .084 mm., length of claws .028 mm. The
sides of the lorica project in front to form a tooth on either side of the
head. The lorica is sculptured into regular areas upon the first seg-
ment. There is a quadrate plate projecting over the base of the
claws. The latter are attenuated toward the end. The details of struc-
ture are not known.

GENUS SQUAMELLA, Ehr.

The three genera Squaniella, Metopidia,‘3a\6. Lcpadella agree closely together, be-
ing characterized by the presence of four, two, or no eyes respectively. The or-
ganization is much as in Euchlanis. The lorica consists of an oval, arching, scale -
like shield above, and a flattened plate below. The foot consists of three short
joints terminating in two acute claws The head terminates above in an oval scale-
like appendage.

They only species belonging to this group as yet seen was hastily
identified with Squamella bractea and, in absence of further informa-
tion, we will simply give measurements in addition to the figure, in
which, by the way, but one pair of eyes is represented, leaving us to
infer that the animal is Metopidia rather than Squamella.

Length .08 mm. — .14 mm. Width (in the latter case) .12 mm.
Found several times in Minnesota.

GENUS STEPHANOPS, Ehr.

The lorica is depressed, and frequently extends into spines posteriorly Head
covered with a shield, which, when viewed from before or behind, is in shape like
a halo There are two eyes, occupying the extreme sides of the head. The
foot is three -jointed and ends in two lanceolate claws, between which springs an
awl-shaped spine.

Stephanops muticus, Ehr.

{Plate Af, Fig. 9.)

A specimen of this species was taken in July, I885. The lorica •
is oblong oval, seeming two-jointed behind. There is a slight crest

OF DENISON UNIVERSITY.

'55

above. Both segments extend dorsally into prominences which only
appear when the animal is viewed from the side. The head is cov-
ered by a thin semi-circular shield, which is slightly arched. The cilia
of the disc are feeble, but the sensory tube is distinctly seen. The
first joint of the foot is quadrate, the two following being of equal
length but different diameter. The claws are ovate lanceolate and
short. The accessory spine is awl-shaped and shorter than the claws.
The length is about .10 mm. Eckstein gives very good and accurate
figures of this species, his description of the viscera is also valuable.

The following species of this genus are known : S. lamellei'is^

Ehr. with three spines behind. S. cii^ratus^ Ehr. with two .spines
behind. S. longispinatus.T?^. S. ovalis,^c:\\m. S. tridcntatus^Yx.

GENUS BRACHIONUS, Ehr.

A large genus containing curiously armed and ornamented species. The body
is depressed, oval or quadrate in outline, presenting a very large anterior opening
always guarded by spines or teeth. Behind, the shell may be rounded or armed
with spines like those in front. There is only a small opening upon the ventral
aspect through which extends the foot. The ventral surface of the body is gener-
ally plane while the back is arched and may be set off into areas by elevated lines.
The maxtax is prismatic and complicated. The egg is carried about attached to
the body of the parent, as in A/iurcea. The males are said not to be rare in this
genus.

BrACHIONUS BAKERl, Ehr.

A single gathering taken in Granville, O., in September, contained
a species belonging in the section of this genus characterized by the
multiarticulate foot.

Our species is sub-quadrate in outline and more or less expanded
back of the middle. The whole length, including spines, is from .30
to .40 mm. for adult females. The oral margin, above, is produced
into six spines. The median pair are longest and curve decidedly
outward and may be from .05 to .08 mm. long ; between them is an
incision, through which ordinarily projects the sensory tube. The
outer pair of spines are half as long and also curve outward. Mid-
way between these pairs is a short spine or tooth. The ventral edge
is notched in the middle, but not toothed. The width of the body
is from .18 to .22 mm. The posterior portion of the shell extends
into two pairs of spines, of which the outermost are very long (.10-
. 14 mm. ) and project directly backward or slightly outward or are uni-
formly curved. / The inner pair of spines immediately border the

56

BULLETIN OF THE LABORATORIES

opening for the exit of the foot and are curved plates. The foot,
which can be almost wholly withdrawn within the lorica, is composed
of a closely ringed basal portion terminated by a short rigid joint,
bearing two conical claws and blunt processes. The claws are perfora-
ted by the ducts of large cement glands. The flexibility and extensi-
bility of the foot are truly wonderful. The whole shell is covered
above with fine granules, but is not otherwise marked. The eye is
large and is seated on the ventral side of a large ganglion. The max-
tax is very wide and short. The manubrium is a curved plate and
the uncus consists of several fused plates (see drawing). I have seen
the animal attempt to masticate a large diatom and, after failing to
crush it, reject it by reversing the usual movement of the jaws. The
pharynx is ciliated and funnel-form. The oesophagus is not ciliated,
but has ringed muscles which, when in motion, give the appearance of
a valvular arrangement. _ The stomach and intestine are strongly
curved upon each other, the former being glandular with fatty spheres
in its walls, while the latter is furnished with a dense coating of cilia.
The pulsating vessel is not large, but the lateral vessels with their beaker
cells are quite conspicuous. This species, which agrees with Br.
Bakeri closely, is common in Ohio, (September).

Another species, known only from a single gathering and imper-
fectly studied, differs from all known species in having a single pair of
spines before and behind and a foot which at the base is multiarticu-
late, but ends in the two long segments, the last with two quite long
claws. The shell is nearly smooth. This species may be called
Br. intermedins.^ as it partakes of the characters of both sections.

Brachionus militaris, Ehr.

( Plate X, Fig. 10. )

It is interesting to compare with the above a related species which
is quite common in the west and which belongs to that section of the
genus characterized by the absence of the ringed basal arrangement of
the foot. This form, which may not be properly Brachionus, resem-
bles decidedly the above in the form of the body. The anterior mar-
gin extends into ten teeth, of which the superior median are longest
and curve ventrally.^ All the other anterior teeth are doubly curved,
the points extending outward. The posterior part of the body bears
two pairs of spines, the relative position (and size) of which is not
constant, The outer pair are always longer and project outward and

OF DENISON UNIVERSITY.

57

backward. The foot consists of three slender joints, the last of which
bears two lanceolate appendages somewhat longer than the segment
preceeding. The whole shell is covered with minute points. The
trochal disc is broken up into five lobes and the cilia are of two sizes.
The measurements of one specimen are given as illustrating the pro-
portions. Length .20 mm. exclusive of foot, width .14 mm., termin-
al stylets .024, lateral, posterior spines .028 mm., anterior spines about
.04 mm.. From the side, the ventral surface (in outline) is seen to be
plane while the dorsal is composed of two inclined planes (or is
‘Tumped.’’) The foot is moved by two pairs of muscles. The con-
tracting vessel is unusually large. The maxtax and the position of the
viscera seem to be as in other species of Brachionus. The animal
seems most to resemble B. militaris, Ehr. of the European species.

Plcesoma lenticulare, gen. et sp. n.

(See figures facing Index.)

The animal for which the above generie name is proposed, was
several times seen in a gathering taken at the reservoir near Hebron,
Ohio, in November. The general form is very similar to that of
many minute bivalved Crustacea ( Chydorns), with which it was asso-
ciated. The lorica is composed of two ovate valves, which are par-
tially united below, so that the foot springs from the middle of the
ventral margin. The animal is laterally compressed. On the dor-
sal aspect of the lorica are several distinct ridges arranged about as
follows : A pair of short transverse markings occupy a point poste-

rior to the middle of the dorsal aspect; anterior to these, and begin-
ning at either end, spring diverging lines which lead to notches of the
anterior margin; behind, two ridges lie on either side the median line
and extend to the acute posterior end of the shell. Several lines
border the above described markings on either side and are approxi-
mately parallel to the axis of the body. Seen from the side, the lor-
ica is elliptical and is truncate in front and acute behind. The dorsal
line is a uniform curve, while the ventral is prominent near the middle
at a point some distance in front of the point of union of the valves.
Seen from above, the front half is quadrate, while the posterior half is
triangular. The lorica is lenticular, considered as a whole, and is
marked by minute hexagonal or irregular depressions.

The head is armed with two long sensory organs and has two sorts
of cilia. The outer series is quite feeble, but the ventral prominence

BULLETIN OF THE LABORATORIES

58

bears several elongated setae. The maxtax is oval and seems to be
but slightly armed. . It is furnished, however, with distinct annular
bands of muscles. The eye is cervical, and is seated on the under
side of a considerable ganglion. The foot is multiarticulate at the
base, as in Brachiomis. Two distinct joints follow this portion, the
last being longer and bearing two oval, appressed spines. Of the
internal organs little was seen. The stomach is glandular and the
egg of but moderate size. The vascular system was not seen.

Length, .24 mm., height, .15 mm., width, ,10 mm. Frontal pro-
cesses, .03 mm., spines of foot, .025 mm., last joint, .02 mm.

GENUS ANUR.EA, Ehr.

Closely related to Notens and Brachiomis is a genus of curious rotifers in
which the foot is entirely absent ,so far, at least, as can be seen. As in Brachio-
nus, the anterior opening is protected by spines or teeth, while there may or may
not be simtlar teeth behind. The lorica is usually distinctly separable into a
dorsal and ventral shield, and the dorsal scutum, is marked off into geometrical
figures by raised lines. There is a single cervical eye. Tbe egg very generally
remains attached to the body and may be mistaken for a part of 'it.

Anuria sp.

A species differing from all European forms is very common in the
West. The form is hexagonal in outline, the length being 1.4 times
the width (exclusive of spines). The anterior margin of the hexagon
is wider than the posterior. The dorsal scutum is produced into six
long spiny teeth, of which the middle pair are much the longest and
are strongly curved outwards and downwards. The remaining pairs
are sub-equal and project outwards like the horns of an altar. The
ventral part of the anterior margin is excavated in the middle and
bears a series of small sharp teeth. The whole shell is ornamented
with circular prominences, and, in addition to this, above there are
strongly raised lines blocking off the shell into thirteen regular areas
and leaving two other areas about the front. The character of these
ridges is best seen from a side view. The eye is cervical and the
trochal cilia are strong for the genus. There is also a sensory tube.

The following measurements, owing to an accident, may not be
accurate, but will give the proportions ; Length, .1 mm. , width, .054
mm,; longest spine, .024 mm.

OF DENISON UNIVERSITY.

59

GENUS PTERODINA, Ehr.

The lorica is flattened, round, or ovate in outline and flexible. Head funnel,
shaped, entirely withdrawn into the body when at rest, furnished with two lines of
cilia. Stomach sac-like with large cilia. The foot is ventral and consists of a
ringed basal portion and a short terminal joint which bears no claws. The intes-
tine is said to be continued through the tail having the anal opening at its end.

The Pterodina is a good subject for use in obtaining a knowledge
of the rotifers as the viscera are quite distinct, the cross striation of the
muscles and the ciliated or beaker-cells of the lateral vessels being
particularly distinct.

Pterodina patina, Ehr.

(Elafe I, Fig. III.)

The form is circular with a slight emargination in front for the
withdrawal of the head. The head is funnel-shaped and bears a*
double 'disc having good sized cilia. When extended, the eyes are
seen to occupy a position about one-third the width of the disc from its
sides. The pharynx is closely ciliated and leads into a comparatively
large maxtax in which a partial fusion of parts has taken place. The
stomach follows upon a very narrow oesophagus and is a curved sac
composed of large cells, each of which is filled with granular contents
and has fatty spheres within it. On either side the stomach is a strong
muscle passing from the sides of the head to the posterior third of the
body where it is fastened. When the head is withdrawn the muscles
are curved, but upon the protusion of the head become straight. On
either side the stomach is a large glandular mass composed of numer-
ous lobes made up of fused cells with large translucent flecks which
may be globules of the secretion. These glands open back of the
maxtax. While the stomach is curved to one side, the intestine lies
behind the tail and is curved upon itself, opening, as claimed by Eck-
stein, into a canal excavated in the tail. ' It is indeed certain that the
tail contains a canal and is ciliated at the distal extremity but we have
never been able to verify the statement referred to. The tail seems
to be more slender in our specimens than figured by European writers,
though it is exceedingly contractile. The contractile vessel seems to
be absent but two very distinct lateral canals are to be seen. The
breaker vessels are long and the cilia active. The ovary occupies one
side of the body, while the egg nearly fills the other when mature.
Large nuclei are discernible imbeded in a granular mass of yolk. The

6o

BULLETIN OF THE LABORATORIES

margin of the shell seems to be granulated and extends beyond the
body-cavity. The tail often is directed at right angles to the body and
is then overlooked. The lorica is about .20 mm. in longest diameter.
The tail measures over . 07 mm. The trochal disc, when expanded,
is .05 mm. wide. A small specimen, but fully adult was but. 17 mm.
long. Mr. Stokes mentions a species of this genus but does not iden-
tify it. There are two other species, viz. P. elliptica and P. clypeata^
Ehr. , which latter occurs as a parasite on species of Assellus. I have
a confused recollection of having seen such a rotifer parasitic upon
Gaimnarus. Ptej'odina complanata of Gosse is almost certainly identical
with Pt. patina.

FAMILY ASPLANCHN.T:A.

This family includes abberant rotifers, which lack the posterior
opening of the digestive organs and are considerably reduced in other
respects. The foot is sometimes almost entirely absent, its position
being marked in these cases by the glands simply. The body is sac-
like and often consists of a single segment in which the various inter-
nal organs are very readily seen. The head is broad and sparsely
ciliated. The maxtax is enlarged and to it is appended an extensible
crop, while the incus is not highly indurated and the mallei are modi-
fied to form a prehensile pair of nippers or pliers. The stomach may
be very extensible and a part is very highly glandular. The water-
vascular system is highly developed and there is generally an accessory
canal bearing the minute beaker cells, while the lateral vessels them-
selves are tortuous and elaborate. Most of the species are carnivor-
ous, while others live upon algae and like plants.

GENUS ASPLANCHN.TIA, Gosse.

The genus is characterized by the sac-like body and the large size
and well differentiated organism as compared with Ascomorpha. The
details mentioned under the family apply.

Asplanchna magnificus sp. n.

(Plate //, Fig. 2.)

This, the largest species of the genus, is most like A. Myrnieleo^ but
is considerably larger and appears to differ from it in several other par-
ticulars. The general form is a prolate spheroid truncated anteriorly
and slightly flattened ventrally. The oral end is furnished with six

OF DENISON UNIVERSITY.

6t

discrete clumps of cilia and two sensory processes. The crop is
large and distensible, the forceps are smooth and toothless. The
oesophagus is long and muscular. The stomach is composed of very
large cells and is held in place by bands of connective tissue. There
are accessory glands between the stomach and crop. The ovary is
pear-shaped (not ' horse-shoe-shaped, as in A. Myrmeleo), and can be
seen to be made up of an elongated ribband of cells folded upon itself.
The pulsating vessel is exceeding large and powerful, while the lateral
vessels are convoluted canals ; accessory to the latter, there are nearly
straight tubes bearing about twenty beaker-cells. The foot is two-
jointed and contains small glands. The muscular spstem is highly
developed and consists of strong bands passing backward from the
head and frequently branching before they are inserted upon the very
pliable external walk Two pedate cells lie upon the viscera and may
represent the visceral nervous system. The nervous system was oth-
erwise found to consist of ganglia upon the oral aspect, one of which
bears a single led eye, and which send nerve-fibers to all parts of the
body. The animal feeds upon species of minute Crustacea, especially
of the genus Chydorus. The greatest length is .9 mm., width, .66
mm., foot, .15 mm. This species was figured in the writer’s Final
Report on the Crustacea of Minnesota, where ?Jso may be found the
figure of

Asplanchna sp ?

This species, which seems to resemble A. Brightwelii of Gosse, is
purse-shaped, being constricted about the head. The jaws are bi-
dentate at the end and ribbed. The foot is entirely absent, but its
position is indicated by the orifice of small glands. The stomach of
the only individual of this species seen contained a number of the
lorica of what may be Aniircea lojigispina^ Kellicott.

Explanation of Plates.

Plate II.

Fig. 1. Dinacharis pocillum, Wax .1

Fig. 2. AsplancJma magnificus, sp. 11.

Fig. 3. EMchlanis ampuliformis, sp. n.

Fig. 4. Salpina affinis, sp. n.

Plate III.

Fig. I . Pterodina patina, Elir.

62

BULLETIN OF THE LABORATORIES

Fig, 2.

Euchlanis hipposideros Gosse.

Fig, 2.1

do portion of lateral vessel with beaker cell.

Fig, 3.

Undetermined.

4-

Amphileptiis gigas,, C. & L.

Plate. IV.

Fig, \,

Undetermined.

Fig. 2.

Squa7nella bractea, Ehr.

^'4^- 3-

Monostyla qiiadridentata^ Ehr, (?). The foot is somewhat too long in

the drawing.

Fig, 4.

Polyai'thra platyptei'a, Ehr.

^4"- 5-

Undetermined.

6.

Diin'ella insigfiis, sp. n.

Plate X.

Fig. 5.

Spirosiomum teres.

7^4^. 6.

Ophridiitm paradoxuni .

7^/^. 7.

Anunea sp.

^'4. 8.

Distyla Mimiesofensis, sp. n.

Fio_ 9.

Stephafiops miUictts, Ehr.

/v\>-. 10

Brachionus //liliaBis, Ehr.

'.Plate II

BnHetin of Demson University LalDratoriesVoI.I.

'--I

BnlletiiL of D emson University LabDratories.Vol . I .

Plate W.

CM.H.

Plate X.

L

Bulletin of Denison University Laboratories. V'ol.I

PlatG X.

'h! trfirvi4,{

VI.

THE CLINTON GROUP OF OHIO.

BY A. F. FOERSTE.

Pi^ospectus.

The title, as given above, does not correctly indicate the scope of
the papers here presented, but will very well serve to designate the
field which I have laid out before me, and which I expect to cover by
means of a series of articles, of which the present paper is the first.
Descriptions of all the important exposures in the state, sections of the
strata, analyses of rock, and paleontological features will be furnished
wherever practical. A collection of fossils, which already bids fair
to rival those at Waldron, Indiana, is expected to furnish the basis of
a description of the fossils of the group as presented in this State.
It is also intended to identify in an independent manner the true rela-
tions of the geological strata usually included by the name Clinton Group,
in our State and Indiana. Although it may be well to state at the outset
that present indications seem to favor a closer relationship to Niagara
strata, and especially those of the west, than is generally conceded ; nev-
ertheless this conclusion has not been hastily drawn, and is not irrevoca-
bly held. I shall only attempt to present the facts and state their
probable bearing, and then allow the reader to draw his own conclu-
sions. In order to determine more definitely the stratigraphical re-
lations of the group with corresponding formations of the west, espe-
cially those of Indiana, a series of sections taken at different
stations, from both Ohio and Indiana, will be undertaken at an early
date. Although the project in some respects may seem rather exten-
sive, the large amount of material already collected gives promise of
its ultimate accomplishment.

64

BULLETIN OF THE LABORATORIES

GEOLOGY.

In southwestern Ohio, immediately, above the Cincinnati Group,
lie a series of strata, formerly known, both scientifically and popularly,
as the Cliff Limestone. They are so designated, for instance, in the
second annual report of the Ohio Geological Survey, undertaken in
183S, by W. W. Mather. Many of the cliffs and cascades in this
part of the State owe their origin to the peculiar characteristics of this
formation. Later, however, a division into two groups was made,
and after a more extended study by Prof. Edward Orton the upper
section was identified with the Niagara Group, but the lower was called
the Clinton. In the reports for 1869 and 1870, these distinctions
were carefully made. At various times, however, ’authors have seen
fit to express doubt of the correctness of the name employed for these
strata, and Prof. James Hall, especially, has had occasion to do so in
the 12th annual report of the Indiana Survey. For our purpose it
will be well enough to retain the name, Clinton Group, at least for the
present, but it is expected that after a presentation of all the facts,
others, perhaps, will be ready to adopt some other term.

The Clinton is not a group of any great depth. For its western
exposures in Ohio, ten to fifteen feet would be a fair estimate. In its
eastern exposures in Highland and Adams counties ‘‘its average thick-
ness is somewhat increased, but probably never exceeds 40 feet, and
this thickness is sometimes attained in the northern district as a maxi-
mum, as for instance, at Yellow Springs, in Greene county.” (Italics my
own). A section of the geological series of Highland County gives
a thickness of 50 feet to the Clinton Limestone. (Geo. Surv. Ohio,
1870, page 298 and section at page 310.)

The Clinton Limestone rarely affords any extended surface expo-
sures, but is found like a narrow line separating the Cincinnati and
Niagara Groups of the State, and usually is seen in close connection
with both. A section of rock belonging to the Clinton age, there-
fore, generally also includes both the upper and lower strata.

The rocks of the Cincinnati Group, in Ohio, are quite level, show-
ing no marked local variations in their dip. At their junction with
the Clinton Group, however, they frequently become unfossiliferous,
and the rock is replaced by less solid shales and bluish clays. d‘he
surface of the group also becomes very undulating in character, fre-
(piently attaining a dip of four feet in forty. As a consequence the
superposed rocks of the Clinton Group are 4l§Q yer^ undulating.

OF DENISON UNIVERSITY.

65

They maintain, however, an average thickness, indicating that, what-
ever were the causes which had disturbed the bed of the Lower Silu-
rian sea, these had disappeared by the time the strata of the Clinton
Group were deposited.

In other words, at the close of the Lower Silurian age, the ocean
became shallow; large valleys and gullies were washed out from the
beds of the Cincinnati Group. The silt was deposited as a blue clay,
which terminates the strata referred to this age. On this uneven and
very undulating bed, the rocks of the Clinton Group were deposited.
At this time a portion of the Lower Silurian rocks must have
been exposed, as the researches of the last geological survey revealed
evident shore markings in several places, containing the pebble-washed
fragments of the Lower Silurian strata.

In fact, the very fragmentary condition of most of the fossils found
in this group indicates the action of shore waves upon the accumulated
deposits of this sea. The slight variation in the thickness of the
group may readily be explained by the conditions brought about by
its uneven bed. The washings of an otherwise shallow sea would
naturally be very unequally deposited near the shore line. At a dis-
tance from the land the fine silt would be almost equally deposited,
but near the shore the washings would accumulate most in- the depres-
sions of the ocean bed. And, although the inequality of deposition
would of course not be very great over any large extent of territory,
nevertheless it is sufficient to account for the variation observed. At
Soldiers’ Home, where there is a dip of seven feet in one hundred,
the rock increases one foot in thickness. This is the most marked
instance which has fallen under my observation.

The Clinton Group consists of a crystalline, crinoidal limestone of
variable color, sustaining a high polish, extremely fossiliferous in places,
differing in this particular from the Niagara strata immediately overly-
ing it.

Between it and the Niagara Group is a fine clayey or marly
bed, about nine inches thick, which in some places becomes quite hard,
and in others is replaced by a soft blue clay. In connection with the
Dayton limestone it usually attains the hardness of stone and is char-
acterized by a number of minute species, which, considering the
small attention hitherto paid to this course of stone, is unusually great.
For the present it will be called the Beavertown marl, on account of

66

BULLETIN OF THE LABORATORIES

its prominent development near that village, and will be considered as
a part of the Clinton Group.

The first, and by far the most important series of exposures to be
mentioned, are those included in the Soldiers’ Home district.

SOLDIERS’ HOME QUARRIES.

The Soldiers’ Home grounds, embracing about a square mile of
land, are situated two and a half miles west of Dayton, on a series of
hills overlooking the city. At their foot, exposures of the Lower Si-
lurian strata are frequent, but at their top, rocks of the Upper Silurian
age take their rise, and have a steady dip towards the west, bringing
up, one after the other, the formations of a higher age.

OF DENISON UNIVERSITY.

67

About half a mile from the Home, at the side of the Germantown
Pike, a well, driven for water, gave rise to a flow of gas, | lasting some
months. Owing to neglect or other causes, the supply has now ceased,
evertheless, the existence of inflammable gas in the Lower Silurian
rocks is’^of some interest.

A short distance westward, the pike runs upon a bed of rock be-
longing to the Clinton Group. North of the road a quarry has been
opened, which displays both the Niagara and Cincinnati Groups, nev-
ertheless a satisfactory section of the Clinton Group has as yet not been
attainable.

68

BULLETIN OF THE LABORATORIES

All measurements of the elevation of rocks in the various sections
are reckoned from the sidewalk at the Court House in Dayton.
These measurements are due to the kindness of Mr. A. Kiehl, who
aided me materially in this part of the work. The top of the Cincin-
nati Group is at 193.51 at the first station. In a section made near
by the Cincinnati layer was not exposed but the lowest point in the
Clinton was at 196.74; the top of the Clinton, 206.31; the top of the
Niagara exposed, 208.68. The thickness of the Niagara was therefore
2 ft. 4.5 in.; and that of the Clinton, considering that the dip from the
first named station, east of the section, was slight, but westward, a
thickness of twelve feet would be more than conjectural. The rock
is crystalline, consists of uneven “lenticular” layers, unequally fos-
siliferous, the fossils being found in ‘ ‘pockets” or special accumulations,
irregularly disposed throughout the group. Numerous fine heads of
Dalmanites Werthneri are quite abundant here, and for many things it
ranks with the Soldiers’ Home quarry itself in productiveness.

The Clinton ends in a top of blue clay containing large crinoid
beads, free specimens of Chaetetes, Rhinopoi^a^ &c. It is about five
or six inches thick. Only the blue clay referred to the Cincinnati
Group is exposed. The Niagara Group consists of a yellow lime-
stone, unfossiliferous as far as known, lying in uneven broken courses
from two to five inches thick. It has no commercial value, but the
Clinton stone is much used for academizing roads and streets, and is
profitable on a small scale, as a gain of $492 with^ an expenditure of
$426 in one instance will show. During this year, 1885, up to
August an expenditure of $356 realized a gain of $547, which is quite
profitable considering the small amount of time put upon the quarry.
The inferior quality of the Niagara limestone at this quarry is to be
especially mentioned as it is the exact equivalent of the Dayton lime-
stone and the succeeding quarries farther west gradually assume the
characteristics of the Dayton stone, thus forming a complete and in-
structive series for comparison.

SwartzhaiigN s Quarry. (^Section I.)

On the same pike within a few hundred feet from the south-east
corner of the Home grounds is a second quarry. It is placed behind
a farm-house, dipping northward into the hill near the barn. The
top of the Cincinnati Group is here represented by a bed of blue clay.
In the sections made, however, this bed was not reached. The hot-

OF DENISON UNIVERSITY.

69

tom of the Clinton Group as far as worked was at 198.21 ft.; the top,
at 208.04 ft.; but a conjectural thickness of twelve feet would not be
far from correct. The stone presents the usual characteristics, but
seems to be less fossiliferous than some of the neighboring quarries.
It is peculiar in showing fissures; extending east and west, distant from
each other about 9 feet, found at no other station in the Clinton Group.
In the southern part of the quarry there is a sudden dip to the south
and the stone is broken, as though the blue clay layer beneath had
given way and permitted the stone to sink. The fissures in the rock
are perhaps also explained in this manner.

The Niagara exposure is a little more than 15 feet in height. The
base of the series is composed of broken, irregular, yellow layers of
stone from two to five inches thick, making a total of 1.9 feet. Above
is a 9 inch course of blue flagging stone, which was at one time
quarried and sold in slabs for pavements. It resembles a fair quality
of Dayton limestone of which it is the stratigraphical equivalent.
Formerly when the Clinton stone was not exposed and the Cincinnati
Group was in plain sight along the hill below, and the great dip of the
rock had not yet been determined, the identity of this stone remained
for a long time a puzzle. Above the blue flagging is a series of shales
3 ft. thick, varying in character, sometimes represented by broken
courses of yellow limestone 2.5 ft. thick, composed of a nine inch layer
above and below, with the intermediate layers more or less shaly in
character. Sometimes the remainder also becomes somewhat shaly.
Last in the series is a 7 ft. layer of yellow^ Niagara stone, formed of
very broken, thin courses, from half an inch to two inches in thickness,
frequently becoming shaly. The top of the blue flag layer in the
southern part of the quarry is at 210.70; seventy-five feet north, at
204.10; fifty feet west, at 203.89. This would give a dip of 4 ft. 5
in. in fifty feet towards the north, and only 2.5 in. in the same distance,
towards the west; the last dip is reliable, owing to the very even stratifi-
cation of the blue flagging. At the same point the bottom of the
heavy Niagara stone is reached at 206.92; the top at 209.49.
Farther west the top is again reached at 207.87, and the summit of the
thin shaly courses at 214.85. All the Niagara stone here exposed is
unfossiliferous as far as known. In some parts of the quarry the
Niagara stone is all tumbled together, destroying its original stratifica-
tion. I presume that the action of ice during the glacial epoch could
readily account for this, since all the quarries round about, where the

70

BULLETIN OF THE LABORATORIES

Stone is hard enough, show evidence of this glacial action in the form
of grooves, scratches and the planed surfaces of the stone.

CaJTollton Pike Quarry. [Section IV.)

Along the Carrollton pike about half a mile from the Home Grounds,
on the east side of the road, a quarry was opened, which developed a
layer of Niagara flagging stone 5 or 6 inches thick. It was smoothed
above by glacial action, was found within two feet of the surface, and
hence was readily worked, and sold to advantage as a fair quality of
Dayton limestone. In several places in Dayton it was used without
extra preparation for side walk purposes. Beneath is a layer of thin-
ner stone and then limestone of the Clinton Group, of little or no com-
mercial value, and therefore, not quarried. Here specimens of
Orthis fausta were found. This species has also been found at Swartz-
baugh’s quarry, in the same position, namely at the very summit of the
Clinton Group.

Eaton Pike Quarry.

North-west of the Soldiers’ Home grounds. On the north side of the
Eaton pike the Clinton rock is quarried. Neither the top nor the bot-
tom of the series is exposed but the two levels taken register 211.92 ft.
and 205.50, which give a thickness of 6 ft. 5 in., but the real height of
the strata is no doubt much greater. Numerous bryozoans are found
here.

Tke Grotto.

East of the Soldiers’ Home along the railroad, a cut through rock of
the Cincinnati Group displays the characteristic fossils of this group.
South of the terminus of the railroad in the grounds are the socalled
grottoes. These were formerly the site of an old quarry, and belong
to rocks of the Clinton Group. Owing to the underlying bed of blue
clay the Clinton Group is usually a great water bearer. At Soldiers’
Home one of the grotto springs is fed in this way, and two springs of
the same nature in the quarry south of the grotto give forth a steady flow
of water all year. The grotto is now used for floral effects only.

Soldiers’ Home Quarries. [Section II.)

The Soldiers’ Home quarry is the finest exposure of the Clinton
Group in the State. Being constantly in operation, it has proved ^he
most productive place for fossil remains. Both the Niagara and Cin-

OF DENISON UNIVERSITY.

71

cinnati groups are shown in the same section, and the thickness of the
Clinton Group as here obtained is strictly accurate.

A' BCD E FG HIJ

Stations.

Top of Clinton Group.

1 Base of Clinton Group.

Stations.

Distances.

Height above Court
House Corner.

Dip for 100 feet.

Distances.

Height above Cotni
House Corner.

Dip for 100 feet.

A __

150

208 95

I 00

.67

G

B

30

198.94

■'"2. 08

■■■‘6.93

I

C —

35

201.02

3-44

9-8.3

D

75

207.95

138

1.84

75

197-58

1. 17

1.56

E __

75

206.57

2.46

3.28

75

196.41

2 70

3.60

F __

150

204. 1 1

3 19

2. 16

150

193 71

5-54

3-69

H__

75

200.92

4-54

6.05

188.17

T

196.38

j

J

Seam in Clinton.

i

|e

Ip in feet.

0

0

V

>7.^

i

198 08
194.79

3-29

1.88

*Dip towards the west.

' A section of the eastern half of the quarry, beginning at A near
Massachusetts Avenue, and extending to the eastern limit, is repre-
sented by the table and section just given. The distances are
reckoned to the next succeeding station on the line ; the height is cal-
culated from the level of the side walk at the Dayton Court House; the
first list of dips consists merely of differences of elevation between
consecutive stations ; in the second these are reduced to the standard
of 100 feet. The dip unless marked by an * is toward the east.

The difference in direction between the base and the top of the
Clinton Group is quite evident, and is owing to the effects of glacial
action which has planed off the stone without regard to its dip, or ele-
vation, as shown for instance at station C. This is still more evident
if the dip near the western end of the section be considered, where the
base of the Clinton is 4 ft. below the same 40 feet north. The entire
eastern half of the quarry shows glacial scratching, planing, and
grooving.

72

BULLETIN OF THE LABORATORIES

It is frequently supposed that the Clinton contains no regular seams,
separating the strata. Whereas this is true in a general sense, as
compared for instance with Cincinnati or Niagara formations, neyer-
theless quite regular seams are occasionally found also in the Clinton
group, especially in the section now under consideration. A long
seam, followed with comparative ease for 175 ft. showed a dip of 3.29
ft. in this distance. A comparison of this line with the base of the
group shows that the strata thicken in the depressions of the underly-
ing bed. This is also shown in the western half of the quarry, where
the group is 14.4 ft. thick at the spring, and 15.6 ft. at a point 150 ft.
north-west of the same, showing an increase of i ft. 2.5 in. The
elevations at the spring are : top of Cincinnati group 192.63 ; of Clin-
ton group, 207.01. Along the we.stern end of the quarry the eleva-
tions of the Clinton: are 202.73 the S. W. corner, 200.07
middle, 202,15 at the N. W. corner, 202.36 at a point east of the
latter. Here the top of the Niagara reached 204.26 showing a thick-
ness of 1.9 ft.; it is a yellow, somewhat shaly stone, becoming
frequently quite hard. Taking the Niagara stone as shown at the
Soldiers’ Home, Carrollton pike, and other quarries farther west, a
good idea of the variability of the base of this group can be formed.
In the western part of the quarry the base of the Clinton Group con-
sists of a greyish or almost white stone, composed of finely comminuted
organic remains, of which the structure has become more or less
obscure. Here many bryozoans have been found in a fine condition.
Clatlwapora Clintonensis and Reiepom angulata in fronds 2 feet and i
foot in. diameter respectively have been seen here. Other fossils,
however, are rather scanty in this stone. Most of the group, how-
ever, is composed of a bluish solid limestone, becoming pinkish or red
by oxidation, and abounding in fossil forms. The summit of the
group in the north-western part of the quarry is especially prolific
in various species of Orthis. dfiie summit of the Cincinnati Group is
composed of blue, clayey shales, several feet thick, and very undulating.
The notable fact is that these ’undulations are mostly local, the strata
taken as a whole, maintaining a comparatively even inclination, as will
be seen by a reference to the map.

In the rocks of the Clinton Group, at Soldiers’ Home, so many
species are found, and so much work has been done, that it would be
difficult to mention the prominent features. Bryozoans, found here
in numbers, are said to be still more common at the Eaton pike c^uarry.

OF DENISON UNIVERSITY.

73

Platyostoma Niagareiise is not unfrequent. Glabellae and pygidia of
two species of Illcenus, are abundant, as are also various shells, corals,
&c. The fossils are not equally distributed. Thin courses of rock
are not apt to be very productive. In the thicker interspersed layers,
however, which show external signs of fossils, considerable numbers
are frequently developed by breaking the stone. Throughout the
Clinton Group the fracture is irregular, and it is very difficult to ob-
tain entire specimens. It is rarer still to obtain specimens completely
loosened from the rock, as one or the other face is apt to be insepara-
bly connected with it.

DAYTON LIMESTONE QUARRIES.

South of Dayton a continuous series of quarries extends from
Beavertown to a poiht about a mile and a half northeast* of the Insane
Asylum. Some of these have been abandoned, but in those now in
operation the Dayton and overlying strata of the Niagara are shown
in section, and small exposures of the Clinton are not infrequent.
As a means of comparison with the district just described, a section of
one of these quarries is given.

Huffmaiis Quarry, {Section V.)

About three quarters of a mile towards the southeast of the Asylum
for the Insane, is a quarry, belonging to Mr. W. P. Huffman, of Day-
ton. A single section of the Clinton Group is said to have been ob-
tained here, while constructing a drain. The strata were 13 feet
thick ; the color is light pink, and its fossils are rather few. The Ni-
agara Group consists of the Dayton limestone, and a few layers of
“blue cap.” The Dayton limestone consists of a 20 in. course of
stone, surmounted by a 26 in. and a 7 in. course. The 20 in. course
separates into a 12 in. layer, succeeded by two 4 in. layers. The 26
in. course, even more readily, is divided into a 20 in. and a 6 in. layer.
The 20 in. layer is naturally the most profitable, and is quarried in
large slabs. The blue cap begins with a 10 in. course of poor quality,
followed by an 8 in. course, still more inferior and often broken.
Above this, iS in. or more of thin slabs, usually in small pieces, may
be found. The color of this blue cap is denoted by its name ; its
commercial value is destroyed by its poor weathering qualities and the
irregular and broken condition of the stone. The quarry, therefore,
presents four and a half feet of good Dayton limestone. The Ni-

74

BULLETIN OF THE LABORATORIES

agara cap is here unfossiliferous as far as known. The Dayton lime-
stone contains corals and orthocerites. Between the Clinton strata
and the Dayton limestone is a bed of blue marl, 9 in. thick, which is
referred to the Clinton Group. It contains large crinoid beads,
Orthis biforata^ var. lynx, and various minute forms not known else-
where in the series. The Clinton Group proper has furnished a py-
gydium referred, doubtfully perhaps, to IllcEnus Madisonianus . The
marl is in this paper called Beavertown marl.

CENTREVILLE QUARRIES.

Centreville, eight miles south of Dayton, is situated on an outlier
of stone, composed of rocks belonging to the Clinton and Niagara
groups. In some places that division of the Niagara Group known
as the Dayton limestone or “ marble” approaches within a few feet of
the surface of the ground, and hence gives rare opportunities for good
and readily worked quarries.

Alienas Qiiariy.

Several years ago, shortly after the construction of the Cincinnati
Northern railroad, a quarry was opened on the farm of John E. Allen,
about a half a mile east of Centreville, ^ This quarry is probably the
most easily worked and most accessible (for purposes of transportation)
in the county. The Clinton rock is here of a pinkish or often dirty
white color. It is exposed only by the removal of the overlying Ni-
agara stone, or by the cutting of ditches. Yet many and often rare
fossils have been found here. Orthis Daytonensis, with both valves
preserved, has been discovered. A thin seam of bluish clay, be-
tween the Clinton and Niagara stone, furnished the large Calymene, to
be described later. This clayey layer has not yet shown any of the
curious little fossils found in the marl at Huffman’s Quarry, although
apparently its stratigraphical equivalent.

Beginning with the base of the Niagara exposure, the courses of
Dayton stone run as follows: a 16, i8j^, 6, 3j4, 2^‘, 4, 4^,
and a in. course. Comparing these courses with those at Huff-
man’s Quarry, it will be noticed that the 16 in. course corresponds to
the 20 in. course of that quarry, and like it is divided into smaller
layers : in this case into a 4 in. layer below and a i ^ in. layer above, the
intermediate divisions, if any, not having been noted. The 18 j4 in*
and 6 in. layers also correspond very nicely to the equivalent divisions

OF DENISON UNIVERSITY.

75

of the 26 in. layer in the other quarry; and the 3^ in. and 2^ in.
layers might be combined so as to correspond to the 7 in. layer.
Above this point comparisons would perhaps prove treacherous.
Above the Dayton stone proper are found shaly layers, 50 in. and 9 in.
thick, which do not sufficiently approach the crystalline character of
the Dayton stone to be classed with it.

MISCELLANEOUS QUARRIES.

In addition to the quarries just mentioned, one or two others are
worthy of at least a slight reference in this paper.

Fauver's Quarry.

About two miles north of Dayton, some distance west of the Cov-
ington pike, is a quarry which displays both the Clinton and Niagara
groups. The quarry presents some peculiar features which will be
made a special object of investigation for the next paper. The Clin-
ton ends above in a layer of blue clay, succeeded by a number of
courses of Dayton limestone, none of which attain any great thickness.
The blue clay layer, besides the usual fossils of the Clinton Group,
has also furnished a specimen of Eichwaldia reticulata, Mr. E. M.
Thresher being the collector.

Fair Haven Quarry. -

In Preble county, half a mile north of the village of Fair Haven,
in a stream entering Four Mile Creek, a quarry has been opened, giv-
ing an exposure of the Clinton. Here there have been found numer-
ous corals so far not known elsewhere in this State, and also the usual
Clinton forms. Among others, a form of Clathropora Clintonensis ,
with unusually large oval openings (passing entirely through the bryo-
zoum and thus forming the branches of the reticulations, ) deserves spe-
cial mention. A species of Ptychophyllum, in a fine state of preser-
vation, occurs here; a similar, if not identical form, being found at
Allen’s Quarry. The exposure does not give a complete section,
but over four feet of the Clinton Group are exposed.

About two miles north, along Four Mile Creek, another quarry has
exposed the higher strata of the Niagara group. Its peculiar feature
is a seam of cherty limestone, about nine inches thick, containing
Atrypa reticularis in well preserved specimens. No other fossils have
so far been noticed.

76

BULLETIN OF THE LABORATORIES

PALEONTOLOGY.

The Clinton Limestone of Ohio is very fossiliferous. The fossils,
however, are often difficult to obtain on account of the hardness of
the rock and its irregular fracture, when submitted to the blows of a
geologist’s hammer. For the same reasons the identification of gas-
teropods becomes extremely difficult, since their apertures are scarcely
ever seen. In one form alone are they of common occurence, Cy~
donerna bilix ; this fossil is of rather frequent occurrence in the upper,
shaly part of the group, from which it sometimes weathers with the
neatness of Lower Silurian fossils in this State. Some forms of bra-
chiopods preserve their outlines very indistinctly. This is true of
Orthis flabella and the small form I have ventured to call O. elegantula,
var. parva. Others are found only as single valves firmly held by
the rock so that only one face, the external or internal, is presented.
On this account it is difficult to associate dorsal with ventral valves,
internal with external features. A few forms, however, occurring in
the higher, more shaly strata, are frequently found well preserved, with
both valves connected. Such are Orthis hyhrida^ O. eleganiula, and
Rhyiidionella scobina. O. biforata f. Clintonensis and Triplesia Ortoni
most frequently are found as fragments embracing that portion of the
valves surrounding the beaks ; these fragments show both t^e external
and internal features. They are also, although not as frequently,
found as entire shells, with both valves united. Eidiwaldia retic-
ulata, Orthis fausta, and Me7dstella umbonata, the last from the
middle of the formation, have all been found as entire shells. The
trilobites are usually found as fragments, the heads and tails being
disconnected. In Illcenus the movable cheeks and glabellae are thus
found separated. In only one specimen of Dahnanites Werthneii
the intermediate articulations of the thorax were discovered. The
association of glabellae and pygidia, therefore, is somewhat difficult.
Still with all these failings, the fossilized forms of the Clinton Group
deserve careful study, and to the careful and painstaking collector they
will form one of the most productive fields of labor in the State.

The fossils of the Clinton Group differ from the remains of the su-
perposed Niagara formations of the State in this important particular,
that, whereas the latter are most frequently found in the form of casts,
the former almost always present the external features. Hence they are
more readily determined and their structure can usually be easily studied
by means of microscopic sections. In the following pages a full ac-

OF DENISON UNIVERSITY.

77

count will be given of the Brachiopoda and Lamellibranchiata of the
group, as far as studied. To this are appended partial accounts of
the Gasteropoda and Trilohita of the same. The next paper will con-
tain a continuation of the account of the latter groups, with a study of
the bryozoans and corals of the group. The latter present a few
features of special importance in the identification of the stratigraphi-
cal relations of this group.

Great pains have been taken in the identification of specific forms,
and new species have been formed only with reluctance, and when there
seemed to be an absolute necessity for such a course. Nevertheless
quite a large number managed to creep in. Of these the most inter-
esting are the series of forms which have so far seemed characteristic
of that portion of the Clinton Group, here called the Beavertown marl.
They are to be specially noticed for their small size, being accompan-
ied with only a few larger species.

If the writer has anywhere been deceived in his judgment, he
would be glad to receive such information as would be useful in cor-
recting the same, since upon the correctness of the identification of
the fossil forms must depend the correctness of all discussions as to
the stratigraphical relations of the Clinton Group of Ohio.

In the description of . fossil forms the nomenclature used by Hall
and Meek has been adopted, and where species are identified with, or
described as closely related to forms already published by these or
other authors, the description of Ohio forms has been as far as possi-
ble adapted to the original description. However, no statement has
been repeated which is not fully vouched for by specimens on hand,
and conformity means only an acknowledgement of the excellence of
the descriptions taken as a model.

Most of the species described in this paper may be found in the
writer’s private collection. Valuable assistance, however, has been
afforded by numerous friends, both in the loan of specimens and books,
as well as in such general information as has proved valuable from time
to time. Among others, the writer feels specially indebted to Mr. E.
M. Thresher and Mr. Geo. Caswell, of Dayton — both active collect-
ors of the Clinton fossils near that city. He also wishes to express
his appreciation of the kindness and interest shown him by Prof. Ed-
ward Orton, of the Ohio Geological Survey, a man of eminent ability,
and whose careful, painstaking work has justly won him a place among
the most honored of i\.merican geologists.

78

BULLETIN OF THE LABORATORIES

I.

Brachiopoda.

Leptsena prolongata.

\

n. sp.

11.

Strophomena patenta.

Hall.

III.

— rhomboidalis.

Wilckens.

IV.

Orthis biforata, var. lynx. f. reversata.

V.

— biforata, var. lynx. f. Daytonensis.

VI.

— flabella, ....

Sowerby.

VII.

— hybrida.

Sowerby.

VIII.

— elegantula, ....

Dal man.

IX.

— elegantula, var. parva.

n. var.

X.

— fausta, ....

n. sp.

XL

— Daytonensis,

n. sp.

XIL

Meristella umbonata,

Billings.

XIII.

Triplesia Ortoni,

Meek.

XIV.

triplesiana, ....

. n. sp.

XV.

Rhynchonella scobina, . ,

Meek.

XVI.

Zygospira modesta.

Hall.

XVII.

Atrypa nodostriata.

Hall.

XVIII.

Eichwaldia reticulata.

Hall.

The Brachiopoda of the Clinton Group of Ohio seem to have their
nearest relatives in the Niagara formations of other States. Eichwal-
dia reticulata is characteristic of the Waldron beds of Indiana. Or-
tJiis hybrida and O. elegantida are widely distributed Niagara forms.
Orthis flabella and Atrypa 7iodostriata recall the Niagara fossils of New
York. Rhynchojiella scobina is closely related to R. iieglecta, a Niagara
fossil of considerable distribution. Leptcp.na prolongata recalls L.
traasversalis of New York. Orthis fausta finds its nearest relative,

perhaps, in O. JVisis, of Kentucky strata, equivalent to Niagara for-
mations. Meristella umbonata is found in the Middle Silurian of An-
ticosta. Strophomena pate^ita^ however, is found in New York, in
rocks undoubtedly Clinton. Three species, Strophomena rhomboidalis,
Orthis biforata var. lynx, and apparently also Zygospira 77iodesta extend
from the Lower Silurian into the Clinton rocks of Ohio.

Of these, St7'opho77ie7ia rho77iboidalis and 07ihis biforata, var. Iy7ix,
have a great range vertically. Stropho77ie7ia pate7ita differs from the
New York types of this species in the finer and more numerous radi-
ating striae. ZygospRa 77iodesta, as stated, has its relations in lower
strata. The testimony of the other fossils seems to be more or less
decidedly in favor of a relationship with Niagara forms.

OF DENISON UNIVERSITY.

79

GENUS LEPT^ENA, Dalman.

I. LePT^NA PROLONGATA, Sp. 11.

( Plate XIII, Pigs. ^ a, b.)

Shell of medium size, concavo-convex, semi-oval ; hinge line pro-
longed, exceeding the width of the shell, lateral extremities acutely
angular.

Ventral valve, alone known, very convex, highest elevation at about
one third the distance from the beak to the anterior margin, thence
curving rapidly towards the anterior margin, and far more so towards
the posterior margin or hinge line, which is inflected. There is a
tendency towards a slight mesial elevation.

Surface marked by fine, close striae, some of which are more prom-
inent, the spaces between being puncto-striate. Interior of shell also
striated in the same direction as the exterior surface, the reticulated
structure of L. transversalis not observed.

This species is closely related to L. transversalis , from which it dif-
fers in its larger size, the lateral prolongation of the shell, especially
along the hinge line, absence as far as known of reticulations among
the interior striae, and by the tendency towards a mesial fold. From
Z. sericea it can be distinguished by its great convexity from the ante-
rior towards the posterior regions. (The specific term is intended to
suggest the lateral prolongation of the shell.)

Length, 13 mm.; breadth, 25 mm.; convexity of the ventral valve,
5 to 6 mm.

Locality and position. Soldiers’ Home, Clinton Group.

genus STROPHOMENA. Rafinesque.

II. Stroppiomena patenta. Hall.

Shell described in Ohio Pal. Vol. II.

Locality and position. Soldiers’ Home Quarries, Clinton Group ;

common.

III. Strophomena RHOMBOiDALis, Wilckens (sp. ).

Described in Ohio Pal. Vol. IT; variable.

Locality and position. Soldiers’ Home and Huffman Quarries,

Clinton Group.

8o

BULLETIN OF THE LABORATORIES

GENUS ORTHIS, Dalman.

Orth IS bifora'ta, var. lynx, Von. Buck.

IV. forma reversata.

{Plate XIII, Fig. 7.)

Shell of the type known as var. lynx, especially those forms, which
show a greater number of plications on the mesial fold and in the
sinus. The name given to the form here described is expected to
have only a local use to distinguish it from the variety lynx, as de-
scribed and figured in the Ohio Geological Reports from the strata of
the Cincinnati formations. Typical specimens of the different varie-
ties of O. biforata from the I.ower Silurian formations of Ohio have
an odd number of plications in the mesial sinus, and an even number
on the mesial fold. Thus var. lynx has typically three in the sinus
and four on the fold. When more than this number appear, the
typical plications are the stronger. Typical specimens of O. biforata
var. lynx in the Upper Silurian formations (Clinton Group), in the
two forms known to me, have an even number of plications in the
mesial sinus, and an odd number on the mesial fold. In the form re-
versata the plications branch frequently, but the typical arrangement
remains clearly defined. Although these distinctions are not expected
to be of value elsewhere, they are too well defined and of too much
interest in our local formations, not to be noted.

Shell attaining a fair size, the dorsal valve a little larger; shell
wider than long, with a sub-graduate outline ; no very gibbous forms
have as yet been found ; hinge line less than the greatest breadth of
the valves; cardinal extremities obtusely angular; lateral margins
rather sinuous near the hinge line, rounding to the front, where it is
somewhat sinuously rounded at the junction of the mesial sinus and
fold. Beaks nearly equal, incurved and approximate, sometimes al-
most touching ; cardinal areas nearly equal.

Dorsal valve more convex than the ventral, its greatest convexity
being near the middle. Mesial fold rather rounded, arising near the
beak, becoming more prominent as it extends forward, with rounded
sides; beak projecting beyond the hinge margin, strongly incurved;
cardinal area directed backward, somewhat incurved. Foramen
broad, triangular and not closed by the cardinal process.

Ventral valve with a mesial sinus, beginning near the beak, ex-

OF DENISON UNIVERSITY.

8i

tending forward, terminating in a rounded projection which continues
the curvature of the shell and thus produces a sinuous outline for the
front edge of the shell. Surface of the valve rounded into the mod-
erately concave sinus. Beak less strongly incurved than that of the
dorsal valve. Cardinal area incurved and directed backward, less,
however, than that of the other valve. Foramen triangular, wider
than high; hinge teeth moderately prominent and trigonal; muscu-
lar cavity oblong, little more than one third the length of the shell,
lateral margins parallel, well defined by the dental ridges. On either
side of this cavity are a number of short stri^, which are arranged in
longitudinal lines following about the direction of the plications.

Surface of each valve with rounded, radiating plications, from 24
to 36 in number, of which four to six occupy the mesial sinus, and five
to seven (in one specimen ten or eleven) the mesial fold. In the
sinus two plications begin at the beak, two additional ones are imme-
diately added, and later one or two more at one third or one half the
length of the shell from the beak. On the mesial fold three plica-
tions originate at the beak, to which two more are added at one fourth
the length of the shell from the beak ; later two more appear and in
one specimen in hand ten or eleven plications are more or less distinct-
ly shown. The plications in the sinus and on the fold branch in all
specimens as described above; the lateral ones, 10-15 in number, are
almost always simple. Lines of growth not shown in the speci-
mens found. Well preserved specimens under the microscope
show numerous minute granules, arranged in regular rows across the
plications.

Length of the specimen figured, 24 mm.; breadth, 28 mm.; hinge
line, 21 mm.; convexity, 18 mm.; breadth of largest specimen, 37
mm. Comparing this description with that given by Meek, in Pal.
Ohio, Vol. I., it will be found to be about the same as that of var.
lynx. (The name of the form is intended to suggest the fact that the
odd and even number of mesial plications are found on valves oppo-
site to those on which they occur in Lower Silurian forms, as though
the shell had been tur7ied about. )

Locality and positmi. Throughout the Clinton Group. Found en-
tire in the Beavertown marl, generally in fragments in the rest of the
group. Soldiers’ Home, Centreville, Huffman’s Quarries.

It may be interesting to notice in this connection that all the forms
of Orthis biforata from the upper Niagara formations of Ohio, which I

82

BULLETIN OF THE LABORATORIES

have seen, belong to a smaller type of the var. lynx^ and are charac-
terized, like our Clinton specimens, by an even number of plications
in the sinus, and odd number on the mesial fold.

V. Forma Daytonefisis.

{Plate XIII, Fig. 8.)

This is another form belonging to the forms typified by the varie-
ties of O. biforata, found in the Cincinnati formations. They bear
considerable resemblance to the young of var. lynx, and in one case, hav-
ing the hinge line greater than the breadth of the shell, it varies somewhat
in the direction of var. acutilPata. The name is expected to have
only a local use for the Clinton forms which have two plications in the
mesial sinus, and three simple ones on the fold, all of which seem to
originate at about the same distance from the beak.

Shell of small’ size, wider than long, with a subquadrate outline,
hinge line usually shorter than or equaling the breadth of the valve, in
one specimen exceeding it in size. The shells have their outline indis-
tinctly preserved and are found only as single valves showing their
exteror surface.

Ventral and dorsal valves with sinus and fold rounded, the plica-
tions also more rounded than those of Lower Silurian formations,
simple.

These specimens could perhaps be considered as the young of the
form reversata, werCit not for the simple plications on both fold and
sinus, which remain simple where on the corresponding places of the
other form there would be several additional plications intercalated.

Length of medium sized specimen, 12 mm.; breadth, 18 mm.;
convexity, as well as can be determined by a comparison of different
single valves, 9 mm. Breadth of largest specimen, 24 mm. (The
name of the form is taken from the locality where it is most frequent.

locality and position. Soldiers’ Home, Clinton Group.

VI. Orthis flabella, Soiverby.

[Plate XIII, Figs. i3 a, b.)

Shell semi-oval ; hinge line equal to the breadth of the valve or
generally a little less. Shell wider than long, the dorsal valve much
more convex than the other, very variable.

OF DENISON UNIVERSITY. 83

Dorsal valve very convex, the greatest convexity being near the
beak ; beak much elevated, incurved.

Ventral valve flattened, with a shallow mesial sinus, more marked
along the posterior half of the shell, towards the beak ; beak but
slightly elevated.

Surface marked by twenty to twenty-four simple, strong, low,
rounded, almost straight plications, equal to the broad, flattish spaces
between them in width.

From the form as described above there are many variations.
The middle plication of the dorsal valve frequently manifests a tenden-
cy towards becoming more elevated and almost forming a low carina
towards the beak ; the other plications becoming more indistinct as they
approach this point. They may also become more angular, more
numerous, approaching thirty in number, and the spaces between them
may become even narrower than the plications. Again, in a few
specimens they divide dichotomously towards their extremities. The
shells also vary considerably in size, from 1 8 to 43 mm. in breadth.
Faint concentric striae may also appear in the depression between the
plications ; lines of growth are still more rare. The anterior and lat-
eral margins of the shell are rarely well defined in our specimens.

Length, 18 mm.; breadth, 26 mm.; convexity, as nearly as can be
determined by comparison of the separated valves, 8 to 9 mm., being
accounted for mainly by the great convexity of the dorsal valve.

The shell has been found only in the form of separated valves, the
exterior surface exposed, the cardinal area invisible ; however, the few
simple plications usually equaling the flat depressions between suffi-
ciently determine this species.

Locality and positio7t. Soldiers’ Home Quarries, Clinton Group ;
very common in places.

VII. Orthis hybrid a, Sowerby.

{Plate XIII, Figs. 10 a, b.)

Shell lenticular, greatest diameter at one third the length of the
shell from the beak, wider than long ; valves nearly equal, hinge line
about half the width of the shell.

Dorsal valve convex, evenly rounded, beak less elevated than that
of the ventral valve, cardinal area smaller, extending the length of the
hinge line.

BULLETIN OF THE LABORATORIES

84

V entral valve convex, with a broad, undefined depression extending
from near the centre to the anterior margin ; beak a little incurved,
cardinal area directed backwards, incurved. Owing to the depression
along the anterior portion of the ventral valve, the shell has a sinuous
outline in front.

Surface marked by fine, close, branching striae, which are arched
upwards along the postero-lateral margins ; radiating striae crossed by
several lines of growth. Concentric striae not distinguishable in the
specimens at hand.

Length, 17 mm.; breadth, 19 mm.; convexity, 8 mm.; hinge line,
10 mm.

Locality and positmi. Soldiers’ Home Quarry, in the upper, shaly
courses of the Clinton Group.

VIII. Orthis elegantula, Dalman.

{Plate XII Figs, ii a, h.)

Shell semi-oval ; hinge line shorter than the width of the shell,
exceeding the length of the cardinal area.

Dorsal valve almost flat, with a shallow depression extending from
the beak to the anterior margin ; more marked near the beak ; beak
not incurved.

Ventral valve convex, extremely elevated towards the beak; beak
much exceeding that of ventral valve in length, and incurved over
the cardinal area.

Surface marked by fine radiating striae, branching, curved upwards
along the lateral and posterior margins ; crossed by lines of growth, and
fainter concentric striae.

This species may be readily distinguished from O. hyhrida by the
flat dorsal valve, and shallow depression extending from the beak to
the anterior margin, also by the more quadrangular outline of the
shell.

Length, 16 mm.; breadth, 17 mm.; convexity, 4 mm.;' hinge line,
10 mm.

Locality and position. Soldiers’ Home and Centreville Quarries,
in the upper courses of the Clinton Group.

OF DENISON UNIVERSITY.

85

IX. var. parva, or young.

(^Plate XIII, Pigs. 17 a, b.)

Among the specimens of Orthis collected at the Soldiers’ Home
Quarries occur great numbers of a small form resembling O. elegantula.
The ventral valve is exceedingly convex and the surface is marked by
fine, numerous, indistinctly preserved striae, being plainest at the lat-
eral and anterior margins of the valve. The beak is very prominent
and incurved.

An ordinary sized specimen of the ventral valve measured gave a
length of 6 mm.; breadth, 7 mm.; convexity, 3 mm. The largest
specimen observed does not exceed 10 mm. in breadth.

The variety occurs frequently in the limestone of the Clinton Group,
whereas the species described above seems confined to the upper, shaly
courses. The main reasons for separating it from the species are its
smaller size, greater convexity, and different location. If not the
young of O. elegantula it is certainly a well marked variety. Its gen-
eral appearance is somewhat like that of O. pisa of New York strata,
but our shell does not have both valves connected and the presence of
an occasional dorsal valve having a low mesial depression, apparently
to be associated with the ventral forms, would preclude such a deter-
mination. For the present it may be considered a variety of O. ele-
gantula.

Locality and position. Widely distributed throughout the Soldiers’
Home Quarries, in all except the uppermost layers of the Clinton
Group.

X. Orthis fausta, sp. n.

{^Plate XIII, Figs. 15 b,c, d) and Figs. 16 a, b.)

Shell of medium size or often less, wider than long ; hinge line not
equaling the width of the shell ; lateral margins rounded in front, pos-
teriorly incurved, frequently expanding at the hinge line just enough to
leave the postero-lateral margins extend a slight distance beyond the
incurved portion of the same, like little ears. Convexity of the
valves almost equal, that of the ventral valve being slightly the
greater.

Dorsal valve convex, with a distinct mesial sinus extending from
the beak to a point about one third the distance from the anterior mar-
gin, where it vanishes ; the greatest convexity lies a little behind the

86

BULLETIN OF THE LABORATORIES

middle, on either side of the mesial sinus. Beak slightly elevated,
scarcely incurved ; foramen broad-triangular, width equal to twice the
height. Cardinal process small, laterally compressed, not filling the
foramen, in a line with the base of the cardinal area ; cardinal area
moderate, one third that of the ventral valve, equaling the hinge line,
directed backwards, arched. Postero-lateral regions of the valve
moderately compressed.

Ventral valve more convex, its greatest convexity about two-fifths
the distance from the beak, sloping regularly to the lateral and anterior
margins. Beak prominent, incurved, having two or three times the
elevation of the dorsal valve; cardinal area corresponding, directed
obliquely backwards, arched ; foramen triangular.

Surface marked by 40 to 50 radiating striae, which increase by fre-
quent intercalations, and are crossed by distinct concentric striae, giv-
ing the surface a beautifully ornate appearance, which will serve to
readily distinguish it from the other species of Orthis found here.
(Figs. 15 a, b, c, d.)

A form of this species occurs having the general shape and char-
acteristics of the typical specimens, but the plications are more angular,
sometimes almost acutely ridged, and crossed by concentric striae,
more closely arranged, and also much less distinct, not producing the
ornate appearance characteristic of the typical form. For this reason
I was once inclined to separate them under a different name, acuto-
pUcata^ but at present I am of the opinion that they are not sufficiently
distinct to be placed even under a varietal name. (Fig. 16 h.)

Length of a specimen, 17 mm.; breadth, 21 mm.; convexity, 9 mm.;
varying from this to specimens with a convexity of only 6 or 7 mm.

This species seems to be a form intermediate between Orthis in-
sciilpta and O. bella-rugosa of the Lower Silurian strata, and O. Nisis of
the Niagara group of Kentucky. It differs from the last in the much
smaller elevation of the ventral beak ; from the second, in the coarser
and broader appearance of its radiating striae, the absence of an in-
curved anterior margin, and by the greater curve of its ventral beak ;
from the first it is chiefly distinguished by greater size and more
numerous striae.

Locality and position. Soldiers’ Home Quarries, Clinton Group ;
the typical forms, in the upper part of the group ; the variety with
more acute plications, in the lower portions of the same.

OF DENISON UNIVERSITY.

87

XL Orthis Daytonensis, sp. n.

[Plate XIII, Figs. 13 a, b, c, d.; Figs. 20 a, b; and Fig. 21.)

Dorsal valve wider than long, very convex, greatest convexity
being just behind the middle, thence sloping almost equally on all
sides, except toward the postero-lateral regions, which are somewhat
compressed ; a faint mesial sinus towards the beak. Cardinal area
narrow, foramen broadly triangular, cardinal process narrow, com-
pressed laterally, and situated beyond a line connecting the lower
edges of the cardinal area, or on the line itself; not filling the foramen.

Ventral valve flattish, its greatest convexity one fourth the distance
from the beak or even closer; thence sloping towards the postero-
lateral extremities and the anterior margin, causing the anterior portion
of the valve to be depressed, and leaving that portion of the shell
extending from the beak to about the middle of the lateral margins
elevated above the other portions of the valve.

The interior of a ventral valve found will be sufficiently explained
by Fig. 20 b, of Plate XIII. A single specimen with both valves
united has been found presenting the characteristics of the valves just
described, and furnishes my authority for uniting them under the same
species. But as a curious matter of fact most of the ventral valves
have been found at Allen’s Quarry, and all the dorsal valves at the
Soldiers’ Home Quarries. The entire specimen is smaller in size than
most of the single valves found.

Surface marked by 60 to 90 fine, radiating striae ; the branching is
frequent and by intercalations. Concentric striae distant from each
other about the space between the radiating striae, or more, giving some-
times the appearance of quadrangular punctae between the striae ; con-
centric striae usually best preserved in the spaces between the radiating
striae, often not very plain on the striae themselves.

Length of a dorsal valve, 17 mm.; breadth, 21 mm.; convexity,
5 to 6 mm. Length of a ventral valve, 21mm.; breadth, 26 mm.;
convexity, 4 to 5 mm. Length of the only complete shell found, 18
mm,; breadth 23 mm.; convexity, 8 mm,; the relative elevation of the
beaks in this specimen may be understood by examining Fig. 21, of
Plate XIII.

Locality a7id position. Allen’s and Soldiers’ Home Quarries, Clinton
Group.

88

BULLETIN OF THE LABORATORIES

GENUS MERISTELLA, Hall.

XIL Meristella umbonata, Billings (sp.).

{Plate XIII, Figs. 2 a, hi)

Shell elongate ovate, the sides forming a continuous curve from the
umbo of the ventral valve to the front margin, with the exception of a
very slight inward curve at the hinge extremities, not at all resembling
those of the Ohio forms of M. cylindrica ; front margin rounded.

Dorsal valve convex, greatest elevation at one third the distance
from the beak, thence obtusely rounded towards the beak which is con-
cealed by that of the ventral valve.

Ventral valve strongly convex, forming a continuous curve from the
anterior margin to the beak, which is spirally incurved upon the beak
of the dorsal valve, which it more or less conceals. The ventral
valve considerably elevated above the beak of the dorsal, more so than
would be indicated by the figures accompanying this description.

' Surface smooth, the concentric striae indistinct.

Length of dorsal valve, 14 mm.; of ventral valve in the same
specimen, 17 mm.; breadth, 14 mm.; convexity, 12 mm. Length of
dorsal valve in a small specimen, 10 mm.; ventral valve, 12 mm.;
breadth, 8 mm.; convexity, 8 mm.

The first inclination was to place these specimens under Meristella
cylindrica, but several reasons will not permit this : the size of the
specimens is smaller, the elevation of the ventral valve is greater, the
length of the shell is relatively smaller as compared with its . breadth,
and considered as young of M. cylindrica, their convexity is too great.
On the other hand they are of the same size and outline as M. iiniho-
nata. Associated with the ordinary forms are also separated valves,
broadly ovate in outline and more nearly resembling those forms
described by Billings under the specific term Prinstana. Since the
writer is of the opinion that this species is only another form of M.
unibonata, its apparent occurrence in the same strata in Ohio with the
form just described, seems to him an additional proof of its identity.

Locality and position. Soldiers’ Home Quarry, Clinton Limestone.
Specimens from this locality were kindly loaned by Mr. George Cas-
well, of Dayton.

OF DENISON UNIVERSITY.

89

GENUS TRIPLESIA, Hall.

XIII. Triplesia Ortoni, Meek.

Described in Ohio Pal. Vol. 1.

Locality and position. Soldiers’ Home and Centreville Quarries,
Clinton Group; the upper ‘‘shovel ends” are frequent in the upper
shaly courses of the Group.

genus

XIV. triplesiana, sp. n.

{Plate XIV, Pigs. 13 k; and Fig. 14.)

The generic relations of the following shell I have been unable to
determine satisfactorily, although the specimens are in a moderately
good state of preservation. A specific name is merely suggested for
the local use of collectors, and a description appended to give notifica-
tion of at least the existence of such a shell. The specific name is
intended to suggest its similarity in appearance to certain very flat forms
of Triplesia Ortoni in which the cardinal area is not much developed.

Shell subquadrate, or rounded anteriorly and more oval in outline,
medium or larger in size; cardinal area scarcely developed, very
narrow, but apparently equalling the hinge line. Beaks approximate,
with about the same elevation, scarcely elevated above the hinge line,
not prominent.

One valve of the shell has a low mesial elevation of moderate
breadth, corresponding to a mesial sinus on the other valve, which is
shallow but equally distinct. The comparative breadth of the mesial
fold and sinus, considering the general contour of the shell, although
suggesting Triplesia Ortoni, is dissimilar. In other respects it suggests
to me a strophomenoid shell.

Surface marked by broad, radiating, scarcely evident folds, and
similar concentric elevations of growth, in addition to which, very fine,
fibrous, radiating stri^ are visible in the more or less silicified shell.
Lateral margin meeting the hinge line at little more than an angle of
ninety degrees, rounded anteriorly, slightly projecting at the middle.

Length, 27 mm.; breadth, 29 mm.; convexity, 12 mm. Length of
another individual, 28 mm.; breadth, 30 mm.

Locality and position. Soldiers’ Home Quarry, in the middle of the

Clinton Group.

90

BULLETIN OF THE LABORATORIES

GENUS RHYNCHONELLA, Fisher.

XV. Rhynchonella scobina, Meek.

Described in Ohio Pal. Vol. I and II.

Locality and position. Soldiers’ Home, Huffman, and Centreville
Quarries, Clinton Group; common.

genus ZYGOSPIRA, Hall.

XVI. Zygospira modesta, Say {sp.).

{Plate XIII, Fig. 6.)

Described in Ohio Pal. Vol. I., and mentioned as occurring in
the Clinton Group. I have seen no specimens which could be re-
ferred without doubt to this species unless it be a dorsal valve of the
following description.

Dorsal valve subquadrate orbicular; beak not elevated; marked by
about twenty simple plications; with a shallow mesial sinus, occupied
by three plications, the middle plication larger, the lateral ones
smaller than the plications immediately adjacent.

Length, 7 mm.; width scarcely larger.

Locality and position. Beavertown marl, Huffman’s Quarry, Clinton
Group.

genus ATRYPA, Dalman.

XVH. Atrypa nodostriata. Hall.

{Plate XIII, Fig. ().)

Shell described in Ohio Pal. Vol. H.

A small species of Atrypa referred here occurs sparingly, of the
following description.

Shell oval, marked by plications, branching near the middle of the
shell. Mesial sinus on the ventral valve plainly defined by the
bordering plication on each side, containing three to five plications.
Dorsal valve with mesial elevation, well defined by a more or less
sharp sinus on each side, which is more marked towards the beak.

Length, ii mm.; breadth, ii mm.; convexity, 6 mm.

Locality cind position. Soldiers’ Home, Clinton Group.

OF DENISON UNIVERSITY.

91

GENUS EICHWALDIA, Billings.

XVIII. Eichwaldia reticulata^ Hall.

{Plate XIII, Figs. ^ a, b.)

Shell broadly triangular ovate, gibbous, cardinal slopes flattened.

Ventral beak small, acute, flattened on the back, closely incurved,
the sinus extending from the beak to the anterior edge, broad, distinct.

Dorsal valve more convex, beak obtuse, strongly incurved, a low,
fairly defined mesial fold extending from the beak to the anterior
margin.

Surface covered by fine, hexagonal, reticulate markings, largest
along the antero-lateral slopes, and decreasing in size towards the sinus
and posterior regions. A small space near the ventral beak is destitute
of markings.

Length, 8 mm.; breadth, 8 mm.; convexity, 6 mm.

Locality and position. Fauvers’ Quarry north of Dayton, Clinton
Group. Collection of Mr. E. M. Thresher.

Lamellibranchiata.

I. Pterinea brisa, _ . . - Hall.

II. Grammysia Caswelli, _ _ _ n. sp.

III. Cypricardites ferrugineum - Hall and Whitfield.

IV. Nucula minima, - - - - - n. sp.

The Lamellibranchiata of the Clinton Group of Ohio are but few

both in the number of species and in the frequency of their occurrence.
Pterinea brisa, if correctly identified, adds another link connecting
this formation with the Niagara Group of the West. It occurs also at
Waldron, Indiana, and Bridgeport, Illinois.

GENUS PTERINEA, Goldfuss.

I. Pterinea brisa. Hall.

{Plate XIII. Figs. 14 <2, b.)

Left valve alone found. Body of the shell obliquely sub-ovate,
extremely inequilateral ; anterior wing moderately extended ; sinuate
at its junction with the body ; posterior wing acutely extended a little
beyond the posterior extremity of the shell ; umbo prominent, beak
rising a little above the hinge line, muscular impression in right valve
unknown from want of specimens.

92

BULLETIN OF THE LABORATORIES

Surface marked by strong, radiating striae, and less conspicuous
concentric striae.

The intercalation of radiating striae in some cases gives rise to an
appearance similar to the dentations and groovings figured in the
Indiana reports, but not identical with them. The concentric striae
also are not so prominent. The crystallized character of our speci-
mens will, perhaps, account in part for these discrepancies. Fig. 14 b
represents a specimen with fewer radiating striae, referred here.

Length, i6-i7mm.; height, lo-iimm.; convexity of the left valve,
about 2 mm.

Locality and position. Soldiers’ Home Quarries, Clinton Group.

GENUS GRAMMYSIA, De Verneuil.

II. Grammysia Caswelli, sp. n.

[Plate XIV, Figs. 12 a, b.)

Shell small, transversely sub-ovate; umbonal regions gibbous, an-
terior regions likewise ; height at the beaks equalling about five-eights
of the length. Anterior end sloping abruptly from the beaks above,
with a distinctly concave outline, to the lower end of the lunule, where
it is met by the rounding base, forming more or less an angle at their
junction; base forming a -broad semi-elliptic curve; posterior end
more compressed, the specimen ' at hand being too imperfect to de-
termine whether it gaps at this extremity, although it is presumed to
do so a little from the curvature of the better preserved valve ; pos-
terior end rounded, then curving upward and quite rapidly forward
almost merging into the hinge line.

Cardinal margin indistinctly preserved, judged to be nearly hori-
zontal, slightly concave in outline, and inflected along its entire length,
forming a well defined escutcheon; lunule distinct, with an ob-ovate
oudine, quite deep. Beaks prominent, strongly incurved, obliquely
to the hinge, directed a little forwards, posterior umbonal slopes prom-
inently, yet rather broadly rounded.

Surface ornamented in the cast by well-defined concentric ridges
and furrows, these in the specimen at hand crossed by fine parallel
lines, almost vertical, directed a little backwards, and which may be
accidental rather than a special feature of the shell. Ridges strongest

OF DENISON UNIVERSITY.

93

anteriorly, becoming less distinct posteriorly. A portion of the shell
where preserved shows the ridges far less defined than on the cast.

Length, 37 mm.; height, 25 mm.; convexity, 25 mm.

Locality and position. Soldiers’ Home, Clinton Group. Collection

of Mr. Geo. Caswell.

GENUS CYPRICARDITES, Conrad.

III. Cypricardites ferrugineum. Hall and Whitfield.

Species described in Ohio Pal. Vol. II.

Locality a7id position. , Wilmington, Clinton County, Ohio, Clinton
Group. To my knowledge not found elsewhere.

GENUS NUCULA, Lamarck.

IV. Nucula minima, sp. n.

{Plate XLV, Pigs. 8 a, b, c.)

Shell (presumably the cast) very small, ovoid, gibbous above the
middle towards the beaks, outline curving to the base and posterior
extremity, anteriorly curving more rapidly to the beaks above. Beaks,
near the anterior extremity of the shell, incurved and inclined for-
wards. Hinge line at one-third the distance from the beak to its pos-
terior extremity supplied on each side with a narrow fold, directed
backwards, making a small angle with the hinge line, and vanishing at
one-third the distance from the posterior extremity in the depressed re-
gions formed by the raised postero-umbonal regions.

Near the beak on each valve are three to four radiating grooves,
which are characteristic of this species and are evident under the mi-
croscope.

In addition to these grooves are three more or less clearly defined
pits, one being placed in the anterior groove near the beak, and the
two others in the second groove, one on each side, and at a greater
distance from the beak. Along the hinge line, anterior to the beaks,
are two or three more or less distinct crenulations, which appear a little
like plications originating in the lunule near the beak and becoming
more distinct at the hinge line.

Length, 2 mm.; height, 1.4 mm.; convexity, i mm.

Locality and position. Beavertown marl, Huffman’s Quarry; not
found elsewhere in the Clinton Group. Associated with many other

94

BULLETIN OF THE LABORATORIES

minute forms, apparently chiefly in the form of casts, among these a
number of gasteropoda.

Gasteropoda.

I.

Cyclonema bilix.

Conrad (sp.).

^ H.

Trochonema nana.

. n. sp.

III.

Raphistoma afhnis,

n. sp.

IV.

Pleurotomaria inexpectans.

Hall and Whitfield.

V.

Cyclora alta.

n. sp.

VI.

Strophostylus cyclostomus.

. Hall.

VH.

Platyostoma Niagarense,

Hall.

VIII.

Bucania exigua.

n. sp.

IX.

Bellerophon fistello-striatus,

n. sp.

The

Gasteropoda of the Clinton Group,

identified with previously

described forms, are too few to form any great basis of comparison,
stratigraphically. Cyclonema bilix ranges from the Lower Silurian into
the Upper. Stivphostyhis cyclostomus is found also at Waldron, Indi-
ana. Flatyostoma Niagarense differs in size and expansion at the ap-
erture from typical specimens, but its connection with them seems
undoubted. At any rate its deviation from the typical forms is far
less than the var. trigonostoma of Meek, and all these forms are typi-
cal of the Niagara.

genus cyclonema. Hall.

1. Cyclonema bilix, Conrad (sp. ).

Shell described from the Lower Silurian in Ohio Pal. Vol. 1.

Locality and position. Centreville and Soldiers’ Home Quarries,
frequent in the upper courses of the Clinton Group.

GENUS TROCHONEMA, Salter.

II. TrOCHONEMA NANA, Sp. 11.

{Plate XIF, Fig. i6.)

Shell oblong, the height about twice the breadth, in the specimen
figured the carina being a little more prominent than is there indicated.
Volutions about three, increasing rapidly in size, the last disproportion-
ately so, forming the larger bulk of the shell, almost equaling two-
thirds the height. Shell thin ; it is impossible to trace the suture line.

OF DENISON UNIVERSITY.

95

but there is a carina where the volutions may be supposed to meet, this
Carina is distinctly grooved along the latter half of the last volution
where it approaches the aperture of the shell ; above the carina is a
low shallow groove which in the last volution spreads so as to cover
the entire volution. Surface smooth. Shell probably in the form of
a cast.

Height, 3 mm.; breadth, 1.5 mm.; height of aperture, .9 mm. (?)
breadth of aperture, .35 mm. (?) above, narrowing to .23 mm. ( ?)
below. The measurements given for the aperture are liable to
error, although there seem to be slight grooves and elevations at the
close of the last volution, which look like an elongated aperture.

Locality and position. Beavertown marl, Huffman’s Quarry, Clin-
ton Group. (Name signifying dwarf. )

GENUS RAPHISTOMA, Hall.

HI. Raphistoma affinis, sp. n.

{Plate XIV, Fig. 18.)

Shell lenticular; breadth a little more than twice the height; con-
vexity moderate above, equally so below ; volutions varying from two
and a half to three and a half, with a moderate slope above, coinci-
dent with that of the spire ; the last volution sharply carinate around
the periphery, convex below, being more so at the umbilicus into
which the slope is abrupt ; suture distinct, forming a small groove
between the volutions ; umbilicus as wide as the outer volution ; the
last volution becoming transversely rhomboidal, the aperture itself not
being preserved, the breadth about three times the height. Surface
apparently smooth.

This species is almost in every respect identical with forms of P.
lenticularis as known to me from the Lower Silurian formations. It
is however a much smaller shell, with less numerous volutions, and
apparently a distinct form.

Breadth of largest specimen, 7 mm.; height, 3 mm.; breadth of
the end of the last volution, 3 mm.; height, 1.2 mm.; aperture not
preserved.

Locality a7id position. Beavertown, marl, Huffman’s Quarry, Clinton
Group. (Nafne signifying related, the shell being closely allied to the
well known species, R, lenticularis.)

I

96

BULLETIN OF THE LABORATORIES

GENUS PLEUROTOMARIA, De France.

IV. PLEUROTOMARIA INEXPECTANS, Hall and Whitfield.

Shell described in Ohio Pal. Vol. II.

Locality and positmi. Iron ore beds of Clinton County, Clinton
Group.

GENUS CYCLORA, Hall.

V. CyCLORA ALTA, sp. n.

{Plate XIV, Figs. 17 a, b.)

Shell very small, conoid subglobose; spire varying from two-thirds
to slightly more than the diameter of the last volution ; volutions three
or four, increasing in size rapidly, but evenly ; the last volution not so
disproportionate in size to the rest of the shell as compared with the
species so far described ; suture deep ; surface smooth ; umbilicus
small ; aperture circular.

Height of largest specimen seen, 4mm.; breadth, 3.5 mm. Height
of a specimen of the usual size, 2 mm.; breadth, 2.75 mm. From
this varying to specimens only 1 mm. broad.

This shell differs from the species of Cyclo7'a so far described in its
greater size, greater elevation of the spire, and the more regular in-
crease of its volutions. Its general form approaches that of the
closely related genus Holopea. Since the chief distinction, however,
of the first genus is its diminutive size, it may be safe to refer to it
also the specimens here described.

Locality and position. Beavertown marl, Huffman’s Quarry, Clinton
Group ; not scarce (Name intended to suggest the height of the
spire, as compared with other -species of this genus.)

GENUS STROPHOSTYLUS, Hall.

VI. Strophostylus cyclostomus. Hall.

{Plate XLV, Fig. 15.)

Shell transversely broad-oval. Spire moderately elevated ; volu-
tions in the specimen figured, three, a fourth having broken away;
the last volution by far the largest, ventricose. Aperture not fully
exposed, oblique to the axis, subcircular.

Surface marked by shallow, broad striae and closer, finer striations
crossing the volutions obliquely and in a direction opposed to them.

OF DENISON UNIVERSITY.

97

Diameter of volutions, measured in a plane vertical to the shell and
passing through the aperture, 6, 17, and 44 mm.; elevation of the
second and third volutions less than half the last.

The character and direction of the shell aperture, the relative size
and position of the volutions seem to leave no doubt as to the identity
of the specimen, and will at the same time serve to distinguish it from
any other species of gasteropod found in Ohio.

Locality and position. Soldiers’ Home Quarry, Clinton Group.

GENUS PLATYOSTOMA, Conrad.

VIL Platyostoma Niagarense, Hall.

( Plate XIII, Pigs. 22 a, b; and Figs. a, b.)

Shell ovoid, volutions three to four, the last much increased in
size, spire elevated above the plane of the outer volution, about one
sixth of the height of the shell.

Apex minute, expanding symmetrically as far as the outer volution,
which is ventricose, and somewhat straightened at the aperture, so as
not to maintain the curvature of the coil ; in one specimen marked on
the upper and lower side by a groove along which the striae are abrupt-
ly bent ; peristome undulated.

Surface marked by fine undulating striae of growth, cancellated by
finer revolving striae.

The specimens referred here are smaller in size than typical forms
of this species from western localities, and they differ from them in the
tendency for the last volution to lessen its rate of curvature and be-
come somewhat straightened as it approaches the aperture. This
straightened appearance is in part due to the slight expansion of the
lip at the aperture. Nevertheless these variances seem too slight to
give rise to any separation from the typical form under a new specific
name.

Height of shell, 21 mm.; elevation of the first three volutions
above the plane of the last, 3.2 mm.; greatest diameter (passing
through the aperture), 26 mm.; diameter vertical to the same, 17 mm.;
diameter of the second and third coils, 2.6 and 7 mm.

Locality and position. Brown’s Quarry, New Carlisle, Clinton
Group, kindly loaned from the collections of the Ohio State Universi-
ty, by Prof. Edward Orton.

In the Soldiers’ Home Quarries occur specimens which have usual-

98

BULLETIN OF THE LABORATORIES

iy been referred to Holopea, both by collectors and writers on geology.
They consist for the most part of the upper three, or three and a half
volutions of a shell which seems identical with the form just described.
The character of the volutions and surface striations are the same; the
last volution is also expanded at the aperture, giving greater distinct-
ness to the lip, and having the same straightening effect on the curva-
ture of the shell at this point.

In the New Carlisle specimens, however, the upper side of the last
third of the last volution is flattened above and quite evenly rounded
on the sides, forming in this way a line of elevation along the upper
side of the volution, where the gradual curvature of the sides meets
the flattened portion above. In the Soldiers’ Home specimen which
is best preserved, there is no flattening along the upper plane of this
last volution, but instead, there is an even curvature from the suture
to the lower side, an elevation being thus formed at the umbilicus into
which the side of the lower third of the volution bends abruptly.

The aperture of this specimen, therefore, is oblique to a ver-
tical diameter of the shell, whereas, in the New Carlisle speci-
mens the aperture seems to have its gieatest diameter vertical
to the shell. Other forms, however, occur at the Soldiers’ Home,
among which are some with deep sutures and less oblique apertures ;
some quite similar to the New Carlisle specimens, but much smaller;
a specimen with its coils arranged somewhat like P. plebium, but only
half its size ( Fig. 3 b. ); and a specimen varying to the opposite ex-
treme, with the last volution extremely ventricose, the upper vo-
lution only moderately raised, the part towards the aperture, however,
being lacking (Fig. 3a). All the forms from the Soldiers’ Home
differ from the New Carlisle specimens, however, in their smaller size,
the New Carlisle specimens differing in turn from the typical western
forms chiefly in their smaller size. All these Clinton forms differ
from the western in the slight expansion of the lip at the aperture and
the straightened appearance of the volutions at this point, the rate of
curvature decreasing.

Specimens last described, at Soldiers’ Home Quarries, Clinton
Group.

(The variations here indicated will be carefully hgured in the next
paper. )

OF DENISON UNIVERSITY.

99

GENUS BUCANIA, Hall.

VIII. BuCANIA EXIGUA, sp. 11.
{Plate XIII, Figs, a, b,

Number of volutions not known, the last alone visible, increasing
rapidly in size and expanding at the aperture; the exact character of
the aperture not known from want of preservation, but is presumed to
be similar to that of B. bilobatiis. The outer volution rounded on the
dorsum at its origin, a mesial carina gradually developing toward the
aperture near which it becomes quite distinct, in some individuals, de-
cidedly so. From this carina the sides slope evenly to the umbili-
cus, which they enter with a sudden curve, forming a low, indistinct,
lateral carina, by the increase of curvature. Umbilicus apparently
closed, the last volution alone being visible in the specimens examined.
Surface of the cast smooth, traces of the original shell, however, seem
to remain in a few spots, indicating a system of striae curving from the
mesial carina obliquely backwards, these apparently crossed by other
striations. The usual form of the cast, however, is smooth, the shell
being entirely removed.

Measurements, on account of the imperfect preservation of the shell
towards the aperture, are of little value, still the following will serve to
give a general idea of the proportions of the shell. Greatest diame-
ter of the typical specimen (Plate XIII, Figs, a, b. ), 9 mm.; diameter
at right angles to this, 6.2 mm.; diameter of last volution at the
point where it becomes visible, 3.5 mm.; broadest part of volution
preserved, 7 mm. From this they vary in size from specimens which
become almost minute to some having a greatest diameter of 22 mm.

locality and position. Beavertown marl, Huffman’s Quarry, Clin-
ton Group. (Name quite small.)

GENUS BELLEROPHON, Montfort.

IX. BeLLEROPHON FISCELLO-S'FRIATUS, sp. 11.
{Plate XIII, Figs. 19 b, c, d.)

Shell sub-discoid ; only the last volution known, increasing rapidly
in size, being almost four times as large at the aperture as at the point
where it first becomes visible ; the increase in size is quite regular, ex-
cept near the aperture where there is a moderate expansion of the vo-

lOO

BULLETIN OF THE LABORATORIES

lution ; aperture not distinctly preserved, but apparently the aperture
was dorsally sinuate, the sinuation being simple and broadly V-shaped :
this, however, can not be conclusively determined. Umbilicus quite
large, and deeply defined. Dorsally the curvature of the shell
toward each side is even and moderate, laterally the curvature is very
sudden, the curvature of the sides into the umbilicus equaling or even
exceeding the dorsal curvature of the shell ; by this means the umbili-
cus is deepened and the sides of the shell appear raised, 3,lmost cari-
nated towards the aperture.

Surface marked by fine longitudinal striae, of which thirteen may
be counted on each side of the carina as far as the beginning of the
umbilicus, these are increased by intercalations with the age of the
shell. Transverse striae in the direction of the lines of growth, the
striae on opposite sides of the carina having an angle to each other
equal to that which the sides of the sinus of the aperture seem to have.
A third, less distinct system of striae, originating at the carina, seems
to make about the same angle with the longitudinal striae as the trans-
verse striae just described. As a result of all these striations, the sur-
face of the shell is divided up into many minute, many-sided polygons
which give the shell a beautiful appearance. This is enhanced by a
low, distinct carina, slightly raised at the sides and thus becoming
grooved. Along the carina only afew, indistinct, longitudinal striae
are here and there visible, there are however many fine transverse
striae, bending backward into the groove of the carina.

Greatest diameter (extending through the aperture), ii mm.; di-
ameter transverse to this, 9 mm. Diameter of the last volution at its
beginning, 2.5 mm.; at the aperture, the diameter passingThrough the
dorsum is 5 mm.; the one transverse to this, 9 mm. The width of
the carina, .4 to .5 mm.

Locality and position. Stolz’s Quarry, Clinton Group.

Crustacea.

I.

Acidaspis ,

II.

Bathyurus, ,

III.

Illaenus Daytonensis,

. Hall and Whitfield.

IV.

— Madisonian us.

Whitfield.

V.

— ambiguus.

n. sp.

VI.

Calymene , .

.

OF DENISON UNIVERSITY.

lOI

VIL Calymene Bliimenbachii ? . . . Brongniart.

VIII. Lichas breviceps, ..... Hall.

IX. Arionelliis ? , .....

X. Dalmanites Werthneri, . . . . n. sp.

The trilobites so far studied seem to be either identical with, or
closely related to Niagara forms. Hall and Whitfield, in their de-
scription of Illcejius Daytonensis, say that “specimenshaving the same
features have been collected from the Niagara Group of Wisconsin and
Illinois.’’ I. Madisonianus is found in Wisconsin; however, I am
unwilling to consider this as good evidence, since the identification is
based upon one specimen, and that, the pygidium. /. ambiguus
finds a close relation in /. insignis, a typical, western Niagara fossil.
Lichas breviceps agrees quite closely in all important characteristics, es-
pecially those of the pygidium, with described forms of this species
from Waldron, Indiana. Dalmanites PVert/meri is closely related to
D. vigilans and D. verrucosus, also from the Niagara strata of Indiana.
Of the other species not much can be said in the present state of
knowledge concerning them.

GENUS ACIDASPIS, Murchison.

I. Acidaspis .

{Plate XIII, Fig. 23.)-

A fragment of a trilobite belonging to this genus has been found,
presenting chiefly the movable cheek, but also portions of the glabella.

Glabella poorly preserved; including the occipital regions its
breadth, as nearly as can be determined, is equal to about one third or
two fifths its length, the widest part being behind the middle, between
the eyes ; lateral lobes apparently three on each side, the middle and
posterior lateral lobes along one side of the glabella being distinctly
defined in the specimen, the third, anterior lobe, less plainly, on ac-
count of the imperfect preservation of the fossil at this point. Lat-
eral lobes of an almost oval outline, directed obliquely forward and
outward, the posterior one larger than the middle lobe, separated by a
distinct furrow from the cheeks and from themselves ; there is a broad
groove between the lateral lobes and the glabella proper, in addition to
which the furrow between the middle and posterior lateral lobes and the
occipital furrow rounding behind the posterior lateral lobe bend

102

BULLETIN OF THE LABORATORIES

towards one another between the posterior lateral lobe and the glabella,
which they seem to connect by means of the raised portion left be-
tween them; this connection is not altogether destroyed by the low
groove which separates them. The occipital regions curve strongly
downwards towards each side, behind and below the posterior
lateral lobe, then slightly outward and forward. On this account the
posterior margin of the glabella is considerably deflected on either side,
beginning a considerable distance beneath the surface of the lateral
lobe and fixed cheek, thence rising to almost the level of the glabella
and again descending on the other side, being gracefully undulated in
this way. The occipital furrow extends from the lower part of the pos-
terior lateral lobe, behind this lobe, as described above, reaching a lit-
tle more than one third the distance across the glabella. The slope
of the rear of the posterior lateral lobe to the occipital regions below
is almost vertical.

Fixed cheek divided from the movable cheek by a furrow, which
between the middle lateral lobe and the anterior lateral lobe ap-
proaches closely to the furrow dividing the lateral lobes from
the cheek ; thence the former is gradually separated from the
latter until it meets the inner margin of the eye, behind which
it seems to curve and then become indistinct. Anteriorly the
fixed cheek slopes rapidly downward and forward, posteriorly it
curves farpnore rapidly downwards, incurving a little below, so that a
distinct furrow seems to separate it from the occipital regions of the
glabella; another furrow, starting at the junction of the glabella and
fixed cheek, curves around behind the eye, separating the raised por-
tion of the cheek between the eye and the glabella, from the posterior
margin of the cheek.

Eye not preserved, judging from indications they were small, placed
in a line with the rear of the posterior lateral lobes.

Movable cheek grooved near the fixed cheek, the groove following
the direction of the furrow separating the cheeks ; that part of the
movable cheek between the groove and the furrow following the curva-
ture of the fixed cheek. From this groove there is a gradual down-
ward and outward curvature of the cheek, the same being true of the
portions at the side of the eye. Behind the eye, there is a more sudden
downward and backward curvature, the groove above mentioned extend-
ing behind the raised regions about the eye near the posterior margin of
the cheeks, spreading out and becoming indistinct towards the lateral

OF DENISON UNIVERSITY.

103

margin of the head. The posterior and lateral margins of the cheek
are distinctly raised so as to form a ridge around the cheek. From
the junction of the lateral and posterior ridge a long, sharp spine ex-
tends almost directly backward, and a little downward. Along the
lateral ridge of the cheek are arranged a number of short spines about
one third as long as the postero-lateral spine. The lateral spines
curve obliquely backwards. They are apparently almost equidis-
tant from each other and decrease in length anteriorly. There is a
lateral spine at the origin of the postero-lateral spine, from this point
to a point opposite to the groove between the middle and anterior dor-
sal furrow 10 spines may more or less distinctly be discerned.

The general curvature of the head is semi-circular from side to side,
the convexity from the anterior portion to the posterior of the head
being far less, although the exact amount can not be determined on
account of the imperfect preservation of the middle and anterior por-
tions of the glabella.

Surface, wherever preserved, distinctly pustulose.

Probable length of glabella, 14 mm.; breadth of the same, 19 mm.;
height of the middle part of the occipital margin above its lateral ex-
tremities, 5 mm.; length of the lateral spines, 2.5 mm.; length' of the
postero-lateral spine, 7 mm. Height of the preserved part of the
glabella above the margins of the head, lo-ii mm. Probable width
of the entire head, 25 mm.

Locality and position. John Brown’s Quarry, New Carlisle, Ohio,
from the collection of the Ohio State University, kindly loaned by Prof.
Edward Orton.

GENUS BATHYURUS, Billings.

II. Bathyurus .

(Plate XIV, Fig. 5.)

Only a single fragment known, whose relation to this genus is rather
conjectural.

Glabella conical, convex, distinctly defined anteriorly and laterally
by a continuous quite deep furrow. Posteriorly a small oval, almost
triangular tubercle is inserted between the occipital furrow and both
of the postero-lateral extremities of the glabella ; owing to these tubercles
the outline of this portion of the head (the regions of the glabella)
seems to broaden at their insertion and then to contract suddenly be-

104

BULLETIN OF THE LABORATORIES

hind them, meeting the occipital furrow at a considerable angle, within
a line directly behind the postero-lateral extremities of the glabella
proper. Dorsal furrow well defined, running behind the tubercles,
forward to a point almost even with the anterior margin of the tubercle,
then back again on the other side. Posterior margin of the regions
of the glabella an almost straight line running just behind the posterior
ends of the tubercles. Glabella proper indistinctly marked by
faint grooves. One of these grooves cuts off from the posterodateral
extremities of the glabella, parts somewhat larger than the tubercles.
A second groove (also directed obliquely forward, but at a smaller
angle) is placed a little anterior to the middle of the glabella, and ex-
tends about one third of the distance across the glabella. Anterior
to this are one or two additional grooves, more faint, and also directed
obliquely forwards, at a slightly greater angle than the last. All of
these grooves are visible only after careful examination.

The anterior margin of the head curves quite rapidly downwards,
so that the general shape of the preserved parts of the head is even
more convex anteriorly than laterally or posteriorly. Anterior mar-
gin separated from the rim by a sort of furrow, from which the narrow
rim rises up at an angle of about 45 degrees. The rim lies in a broad
curve, passing within a short distance of the groove defining the ante-
rior portion of the glabella. The facial sutures begin at the rim on a
line about even with the lateral margins of the tubercles, thence ex-
tending inwards with a slow curvature, approaching within a very short
distance of glabella behind its middle, and then apparently extending
outwards where the outline is lost from want of preservation of the
fossil. The antero-lateral extremities of the margin are therefore
almost’rectangularly pointed.

Length of the glabella to the occipital furrow, 7 mm.; to the pos-
terior margin, 8.2 mm.; from the posterior margin to the anterior rim,
10 mm. Breadth of the glabella at its middle, 6.2 mm.; at its poste-
rior, 6.9 mm.; across the tubercles, 7.4 mm. Distance between the
tubercles, 4 mm. Length of the anterior rim, about 7.8 mm.

Locality and position. Soldiers’ Home Quarry, Clinton Group.

GENUS ILLyLNUS, Dalman.

III. iLLa^NUS Daytonensis, Hall and Whitfield.

{Plate XIV, Pigs. 4 a, b; Fig. 6; Figs. 7 a, b, c)

Species described by Hall and Whitfield in Ohio Pal. Vol. H.

OF DENISON UNIVERSITY.

105

Fixed cheeks one-third as wide as the space between the dorsal
furrows. Palpebral lobes not coming to as sharp a point as figured
in the Ohio report, but apparently a little rounded at their ends.
Postero-lateral limb of the glabella beginning with a small groove at the
base of the dorsal farrow which gradually widens towards the suture
line, where it extends from the palpebral lobe to the occipital margin.
Posterior portion of the facial suture curves outward from the posterior
of the palpebral lobe, cutting the occipital margin at, or slightly
beyond a line vertical to it and drawn from the most prominent part of
the palpebral lobe.

Anterior margin of the pygidium trilobate, the middle lobe project-
ing a little, the lateral ones slightly curved at first, almost straight,
then bending strongly and obliquely backwards, more or less angular
at this point; then curving around and after a slightly angular deflec-
tion coalescing with the lateral margin. Antero-lateral angles never
so prominent as those figured in the Ohio Report, although somewhat
approaching them in this feature.

Movable cheeks small, greatest elevation at the upper posterior
margin, making a large sweeping curve as it passes from the posterior
to the lower or lateral margin. The facial suture before the eye mak-
ing an angle of 30 degrees with the lateral line. Since this suture
line agrees with the corresponding part of the glabella, these separated
cheeks have been referred here.

Glabellae, pygidia, and movable cheeks so far not found in con-
nection. The association of the glabellae and pygidia may be con-
sidered certain from their relative frequency and similarity to nearly
related species. The cheeks are more conjectural in their relationship,
although tolerably certain from their form.

Smallest glabella, 9x11 mm. One of larger size, 40 mm broad at
the palpebral lobes, 30 mm. long, 13 mm, high. Smallest pygidium,
4x5 mm. One of larger size, 34 mm. broad, 25 mm. long, 5 mm.
high. Movable cheeks 7-8 mm. broad, 12 mm. long to the point
where it disappears beneath the glabella. Eyes two mm. long in the
small specimens found.

Locality and position. Soldiers’ Home, Fair Haven, Preble county,

Clinton Group, abundant.

io6

BULLETIN OF THE LABORATORIES

IV. ILL.ENUS Madisonianus, Whitfield.

{Plate XIV, Pigs, i a, b; Figs. 2 a, b.)

Pygidium paraboloid in outline, its anterior margin arching strongly
forward in the middle, and its surface very convex. Lateral margin
spreading, forming a broad shallow furrow around the sides and behind,
just within the edge; anteriorly this furrow extends up the articulating
slope or facett of the pygidium, leaving it at about half the distance
from the top of the anterior margin. Anterior margin with a rounded
ungrooved edge, its corners just without the lateral furrows deflected
downwards and forwards. A narrow faint ridge running from the
posterior edge, half way up the pygidium. Entire surface minutely
punctate with small pits . i mm. in diameter, these interspersed with
others of still smaller size.

Length, 30 mm.; breadth, 38 mm,; height 14 mm.; extension of the
anterior margin forward beyond a line connecting the antero-lateral
extremities, 9 mm. At the middle of this line is found the greatest
elevation of the pygidium.

Our specimen is le.ss abrupt at the sides than the one figured by
Whitfield and has a smaller elevation along its posterior portion, but
the general characters agree very closely with the published description
and figures of the original. The recurved spreading margin seems to
distinguish it from I. insignis of Hall, the nearest related species.

Locality and position. Clinton Group, Huffman’s Quarry.

Another individual from the Soldiers’ Home Quarries is propor-
tionately broader, more depressed, less extended anteriorly, and pro-
vided at the anterior margin with a groove. Otherwise it agrees
closely with the above form,

V. Illh^nus ambiguus, sp. n.

{Plate XIV, Figs. 9 a, b; Figs. \o a, b, c; Fig. ii.)

Glabella regularly arcuate from front to base ; anterior border with
the margin neatly rounded. Occipital furrow well defined, with a
faint upward extension at its middle, barely visible, within which is a
minute granule, which can readily be recognized on wetting the speci-
mens. Extending towards the anterior margin from this part is an
indistinct ridge, which can be recognized only with difficulty, except
in an occasional specimen where it may become moderately distinct.

OF DENISON UNIVERSITY.

107

This corresponds to a much more evident (although narrow) ridge, on
the pygidium associated with these glabellae. In the occipital furrow
at about two-thirds the distance of its postero-lateral margin from the
granule is a deep, very distinct pit becoming shallow in older
specimens.

From this the dorsal furrow extends inwards as a deep groove
forming a broad, oval depression opposite the palpebral lobe, thence it
extends as a shallow groove, rapidly becoming indistinct, in an out-
ward direction, terminating in a small pit, which can be easily recog-
nized even in specimens which do not show the connecting part of the
groove distinctly, as is usually the case. This pit contains a minute
granule. It is situated at two-thirds the distance of the anterior
margin from the palpebral lobe. Half way between this pit and the
anterior margin is a minute granule, easily visible on wetting the speci-
men. Widest part of the glabella lies between the palpebral lobes,
anterior to which it becomes narrower and again widens reaching
almost the same width at a point just behind the junction of the facial
suture with the anterior margin. Facial suture extending from the
edge with a distinct outward curvature to a point opposite the terminal
pit of the dorsal furrow where it makes a rapid curve inwards to its
junction with the anterior margin, in which the facial suture seems to
terminate without any break. Palpebral lobe rounded. Facial suture
behind the palpebral lobe starts from the posterior incurved extremity
of each eye, and curves rapidly outward, cutting the margin directly
behind or a slight distance beyond a vertical line drawn from the most
prominent part of the palpebral lobe to the occipital line. Greatest
elevation of the glabella lies between the palpebral lobes.

Pygidium semi-circular in outline, becoming slightly paraboloid in
larger specimens, with a narrow more or less strongly marked ridge.
Ridge extending from the posterior margin upwards, usually not
reaching the middle of the pygidium. It can always be recognized.
Along the anterior margin lies a groove, which is somewhat straight
along its middle third, a small inward curvature near the middle, being
very slight, aids in this appearance. At either side the groove makes
a short curve inwards, and then outwards, approaching the lateral
margin, along which it extends for a short distance, rapidly becoming
obsolete. The deflection of the antero-lateral border causes a raised,
ridge-like eminence to remain between it and the antero-lateral portion
of the marginal groove. Pygidium flattish along the upper anterior

Io8 BULLETIN OF THE LABORATORIES

surface; greatest elevation at one-third the distance from the posterior
margin, from this point rapidly curving downwards to the posterior
margin, less rapidly towards the side and anterior portion.

Movable cheeks broadest at the posterior end of the eyes, with a
deep-rounded furrow around the base of the eye. In large specimens
rounded above. The facial suture inclining at an angle of sixty
degrees to the lateral margin in front and meeting it at an angle behind
which might be called a right angle, with the vertex rounded. It has
also quite a sharp edge along its posterior margin, where the cheek
makes a curve beneath the glabella. Since the angle made by the fa-
cial suture anterior to the eye corresponds to that made by the suture
anterior to the palpebral lobe in the glabella, the cheeks are associated
with this species. Eyes placed almost parallel with the upper part
of the movable cheeks, lunate, forming about one-third of a circle.
Lenses minute, about 17 to a millimeter. In the specimen examined
they were only fairly preserved but there were about 20 in the vertical
rows and perhaps 125 in the horizontal ones.

Glabellae, pygidia and movable cheeks so far not found in connec-
tion. The association of the glabellae and pygidia may be considered
tolerably certain from the great abundance of both as compared with
those of I. Daytonensis^ the only other species found here in abundance.
The association of the movable cheeks with these forms is more con-
jectural.

Smallest glabella, 8x10 mm. Ordinary sized specimen, 38 mm.
broad across the palpebral lobes; 35 mm. across the anterior pits of the
dorsal furrows. Direct length of glabella from anterior to occipital
margins, 23 mm.; from anterior margin to a line drawn from the occipital
margin perpendicular to the plane of the lateral margin, 20 mm.; height,
14 mm. A few large forms have been found which I refer to this
species. The largest and most perfect of these is in the collection of
Ira Crawford. It measures 60 mm. across the palpebral lobes and
54 mm. in a direct line from the anterior to the occipital margin ;
height, 30 njm. Smallest pygidium 10x13 mm. Ordinary sized speci-
men, 29 mm. broad at the antero-lateral margins; 24 mm. from pos-
terior to articulating margin ; 8 mm. high. A single large pygidmm
referred here measures 52 mm. in width; 44 mm. in length; 16 mm.
in height. Movable cheeks, large specimen, length, 31 mm.;
breadth, 20 mm.; length of eye, 7 mm. Smaller specimens propor-
tionate.

OF DENISON UNIVERSITY. I09

Usually in the form of casts, surface where preserved apparently
striated concentrically, at least around the edges, and dotted with small,
shallow pits.

Locality and position. Soldiers’ Home and vicinity. Clinton Group.
Abundant.

GENUS CALYMENE, Brongniart.

VI. Calymene . •

I^Plate XIII, Fig. 24.)

Portions only of the head found, as fragments ; the figure partly a
restoration effected by a comparison of numerous fragmentary speci-
mens. A fuller description will be given in the next paper if better
material be found.

Glabella more prominent than the cheeks, very strongly defined
from them by a deep, flat, longitudinal depression, which extends from
the tip of the middle lateral lobe forward, forming an almost straight
line along the line of separation from the fixed cheek, and terminating
near the anterior end of the glabella, the side towards the fixed cheek
being somewhat pointed. A similar depression behind the middle
lateral lobes separates the posterior lobes from the surrounding portions
of the head, its curvature being about that of the margins of the pos-
terior lobes. The anterior border of the head is broad and flat, and
directed upwards, with no arching along the middle as in specimens of
Calymene Niagarensis. The anterior rim of this border has a slow
curvature, appearing more like a straight line in some specimens than
any species I am acquainted with. In other specimens, however,
there is a somewhat greater curvature to the anterior rim. The fa-
cial sutures beginning with a slight outward curve for a small distance
become almost parallel to each other as far as the eyes (which I now
believe are incorrectly indicated in the drawing). Occipital furrow
and as much of the fixed cheeks as is preserved, seem similar to the
corresponding regions of C. Niagarensis.

Measurements are not given, on account of the unsatisfactory con-
dition of the specimens. The figure is based upon a specimen pre-
serving the glabella, anterior border and portions of the fixed cheeks,
(all of the cheek anterior to the middle lateral lobe on one side of the
glabella.) The rest of the figure is the result of comparison. The
description is given mainly to note the existence of a form which has

I lO

BULLETIN OF THE LABORATORIES

a broad ^ flat^ anterior border^ with no arching in the middle^ and with al-
most parallel facial sutm'es anterior to the eyes. It will be made the ob-
ject of future study.

Locality and position. Soldiers’ Home Quarries, Clinton Group ;
not rare.

VII. Calymene Blumenbachii ? Brongniart.

{Plate XIII, Fig. 25.)

General form broadly oblong.

Cephalic shield short and broad, the width twice as great as the
length. Glabella quite prominent, projecting above the rest of the
head; its general form, including the lateral lobes, conical, widest across
the posterior lobes, the width at this point slightly more than its length
excluding the occipital ring, and only four-fifths its length including
the same. Glabella supplied with three more or less distinct lobes
laterally, the posterior lobes large and prominent, equal in elevation to
the glabella between them, although they seem to rise above, it, on ac-
count of its downward slope posteriorly; the middle pair of lobes
about half their size, the anterior pair small, indistinct. The middle
and posterior pairs of lobes separated from themselves by deep grooves,
from the glabella by grooves becoming shallow at the point of union
of the lobes with the glabella, and from the cheeks by grooves of less
depth, becoming shallow at the middle lobe ; a slight groove anterior
to the occipital furrow connects the deepened grooves extending along
the anterior edge of the posterior lobes. The anterior part of the
glabella quite regularly rounded. The curvature of the glabella
towards each side much larger than along its length, the latter being
almost regular along the middle of the glabella. Occipital furrow
very distinct, arched forward along the centre, curving forward also
at each side, around the posterior lobe ; the posterior edge following
about the direction of the occipital furrow. Anterior border of the
head forming a broad and even curve about the head, the border fair-
ly broad, flat, turned a little upward, not arched in the middle, somewhat
like the species last described. Facial suture beginning with a slight
outward curvature at its very origin, then a gradual inward curvature
as far as the eye, then it curves around the eye, and posteriorly to it
takes an almost lateral direction as far as the edge of the ele-
vated regions of the head, along this edge it is directed to the

OF DENISON UNIVERSITY.

Ill

postero-lateral edge of the head. Palpebral lobe fairly prom-
inent. Fixed cheeks provided with a very deep and broad fur-
row close to the posterior margin, following its direction. Movable
cheeks with thick, rounded lateral margins, defined by a distinct,
rounded, lateral furrow, above which the remaining portion of the
cheek is decidedly elevated. The curvature of the anterior and lat-
eral margins of the head is quite regular, with the exception of a slight
more or less evident inward curvature just behind the origin of the fa-
cial suture.

Thorax not entirely preserved, the number of articulations not
known. Central lobe of the articulations elevated above the lateral
lobes, more arched than the lateral lobes, separated from them by a dis-
tinct longitudinal furrow. Segment of the middle lobe arched forward
along the middle, also bent a little forward at the sides, where they
show a low, nodal thickening. The grooves separating the segments
deeper at the sides, leaving a sort of axis along the centre of the middle
lobe. The articulations of the lateral lobes extend laterally for a short
distance and then are deflected posteriorly to their ends. A longitudi-
nal furrow extends along each articulation dividing off its anterior part
by a deeper and broader furrow than that which separates the articu-
lations from each other.

Width of the head, about 64 mm.; length, 30 mm. Width of the
glabella across the posterior lobes, 21 mm.; length, not including the
neck segment, 19 mm.; including the same, 24 mm. Distance be-
tween the points of union of the facial sutures and the lateral margins,
19 mm.; forward extension of the anterior border, 6.5 mm. Proba-
ble length of the entire specimen, 105 mm.

Locality and position. Allen’s Quarry, Clinton Group, in the up-
per shaly course. The specimen crumbled partially away on re-
moval.

Fragments of glabellae and surrounding portions belonging to this
species are found at the Soldiers’ Home Quarries, also near the top of
the group, in the upper shaly courses. Associated with these are
pygidia, which seem to belong to this species, the connection is, how-
ever, rather conjectural than otherwise.

Pygidium wider than long, the posterior edge making a very broad
curve, almost straight along the middle. The anterior and lateral
margins as far as preserved having an almost semi-circular outline.
Middle lobe rapidly tapering posteriorly, segments about eight, the tip

1 12

BULLETIN OF THE LABORATORIES

of the lobe (for an extent corresponding to about two segments) not
divided, rounded posteriorly, the segments nearest the thorax similar
to the segments there found. The more posterior segments have their
ends curved decidedly backward, so as to follow the general semi-
circular arrangement of the articulations of the lateral lobes. Lateral
lobes divided from the mesial lobe by a distinct, quite deep furrow,
broadening posteriorly. Articulations about six.^ The anterior
articulations together with the segments of the mesial lobe forming a
semi-circular curve. The posterior articulations become less curved
and take a more decidedly backward direction. The last pair of ar-
ticulations in this way become almost parallel to one another and
together with the posterior edge of the pygidium form a sort of box
into which the unsegmented portion of the mesial lobe enters from
above. The articulations of the lateral lobes are furrowed above
along the middle, the furrows extending almost to the edge of the
pygidiT_.m.

Surface of the pygidia, and the head and thorax described above,
finely granulated.

Width of pygidium, 37 mm.; length, 25 mm.; width ofthe anterior end
of the mesial lobe, 15 mm.; width at the beginning of the unseg-
mented posterior portion, 6 mm.

Locality a?td position. Allen’s and Soldiers’ Home Quarries, in the
upper, shaly courses of the Clinton Group.

GENUS LICHAS, Dalman.

VIII. Lichas breviceps. Hall.

{Hate XIII, -Figs. 26 a, t, c, d.)

Glabella (Fig. 26 b) of one specimen convex. The middle lobe
rounded in front, on each side suddenly and deeply incurved by the in-
troduction of two lateral lobes, the sides almost parallel for a short
distance posteriorly, then curving for a short distance outwards so as to
meet the occipital furrow; at the point where the last curvature begins
the posterior part of the lobe is 2.5 mm. broad, along the occipital fur-
row, 5 mm.; the width of the lobe is exactly equal to its length.
Lateral lobes sub-reniform, almost twice as long as wide, separated
from the middle lobe by sharp grooves evenly curved except at the
posterior end where 'the expansion of the posterior end of the middle
lobe causes a slight irregularity of curvature; anteriorly the lateral

OF DENISON UNIVERSITY.

II3

edges of the lateral lobes continue the curvature of the anterior edge
of the middle lobe, then they make a slow broad inward curvature, the
posterior edge of the lobes being bounded by a groove continuing that
part of the occipital furrow extending beneath the middle lobe.
Within the inw'ard curve of each reniform lateral lobe lies another
lobe which I shall here call the postero -lateral lobe. Postero-lateral
lobe separated from the lateral lobe by a sharp groove, its posterior
edge is defined by a continuation of the groove behind the lateral
lobes, directed a little backwards, however ; from the palpebral lobe it
is separated by a distinct groove curved outward and then inward, the
curve disposed to be angular at its middle. Palpebral lobe preserved
only anteriorly, its outer lateral edge elevated above the inner, the
whole palpebral lobe having evidently been elevated along its outer
surface. Postero-lateral tubercles transversely oblong lanceolate, in-
serted beneath the lateral and postero-lateral lobes, posteriorly they are
bounded by the occipital furr./W which bends somewhat backwards
from the postero-lateral edges of the middle lobe so as to define
the edges of the tubercles. The posterior edge of the neck segment
has a very slight forward curvature towards the"! middle. Anterior
margin of the head narrow. Surface irregularly pustulose.

Width across the widest part of the middle lobes, 8.6 mm.; across
the lateral lobes, 9.5 mm.; across the postero-lateral lobes, 11.5 mm.;
across the postero-lateral tubercles, 8 mm. Distance between the
tubercles, 4 mm. Length of the middle lobe, 8. 6 ; including the neck
segment, 10 mm. Stolz’s quarry.

Another glabella shows only middle, lateral, postero-lateral and
palpebral lobes, with only a little of the neck segment nearest to the
occipital lobe. It agrees with the foregoing specimen in all particulars
as far as can be seen, except in the existence of alow groove across the
posterior end of the middle lobe where it begins to take an outward
curvature. This groove is parallel with the occipital furrow just
behind it. The palpebral lobe is also better preserved and shows a
regularly rounded outer edge, the surface elevated along the outer
margin. Surface of the glabella irregularly pustulose. John Browm’s
Quarry, New Carlisle. Specimen almost twice the size of the last.

A third specimen (Fig. 26 a) differs widely from the two above in
some things. It is far more convex, and proportionately wider.
The grooves about the glabella and the lobes into which it is divided
also differ materially, more so than the figure intimates, b4t a fuUei:

BULLETIN OF THE LABORATORIES

II4

description will be deferred until more and better material is at hand
for accurate description. Stolz’s Quarry.

Pygidium, general form semi-elliptical, quite straight along the
anterior border, rapidly curved at its antero-lateral extremities! Axial
lobe broad and strong, very prominent in the anterior part, rapidly
narrowing and becoming low in the middle, and again widening pos-
teriorly, but not equaling its anterior width ; its width at the anterior
margin one third the width of the pygidium ; one distinct anterior
annulation, with apparently a faint indication of a second. Lateral
lobe with three segments on each side, and each marked by a distinct,
longitudinal furrow along its middle. At their posterior side the two
anterior lobes project a little beyond the margin of the pygidium, the
rest of the outline being regularly rounded. The two anterior seg-
ments directed backwards, the posterior segment bent first a little out-
ward then backward, filling up the outline along the contracted middle
of the axial lobe. Under the exterior crust of the pygidium are a
series of lamellose striations following the posterior and lateral outline
of the pygidium and reaching about one-third the length of the pygi-
dium towards the centre. Surface pustulose as in the first described
glabella; having been found in the same piece of rock, it is supposed to
be the pygidium of this species.

Length of the pygidium, 17 mm.; width, 24 mm. Width of the
axial lobe anteriorly, 8 mm.; along the contracted portion, 4 mm.; at
its greatest expansion posteriorly, about 6.5 mm. Stolz’s Quarry.
Other pygidia presenting the same features found here.

Locality and position. Stolz’s Quarry, both glabellae and pygidia;
John Brown’s Quarry, New Carlisle, a glabella, kindly loaned from
the collection of the Ohio State University, by Prof. Edward Orton.
Clinton Group.

(;enus ARIONELI.US, Barrande..

rx. Arionet.lus .

[Plate XIV, Fig. 3. )

It would be difficult to tell why the species here described should
])e })1aced under the geneiic name above mentioned, differing, as it does.

OF DENISON UNIVERSITY.

in almost every important characteristic ; nevertheless in some respects
it seemed to me to be as closely related to this genus as to any other,
and until further study may lead me to a more definite result, I con-
cluded to leave it here.-

Glabella very convex towards the anterior margin, which is rounded ;
less convex laterally ; separated from the cheeks by almost straight fur-
rows, converging behind to about four sevenths the width of the gla-
bella at its broadest part. At about half the length of the glabella,
on each side, are two grooves. The middle pair are broadly crescent
shaped, the points directed downward, distant from one another about
two fifths the width of the glabella at that point, their general direction
being lateral; they do not quite reach the lateral margins, however.
From the ends of these, a second pair of crescent shaped grooves ex-
tend forward and laterally, reaching the furrows which define the later-
al sides of the glabella. The second pair does not merge into the
first at their adjacent extremities. Behind these grooves a third pair,
distant from each other about two fifths the width of the glabella at
that point, cut off about one third of the lower half of the glabella;
they are directed obliquely backwards, at an angle of about sixty de-
grees with a line extending lengthwise along the glabella; their curva-
ture is first a little backwards, then more laterally, then a little back-
wards again, making a gracefully undulated curve which does not quite
reach the lateral margin of the glabella ; a fourth pair of grooves, cut-
ting off the last third of the lower half of the glabella, is similar to this pair.
The occipital furrow is scarcely preserved but seems to have been regu-
larly curved, the middle of the curve being directed forward.

Fixed cheeks, at least as far as preserved, highest anteriorly, where
their convexity is also the greatest. The front margin beginning just
behind the first pair of grooves on the glabella is curved postero-later-
ally, then backward and slightly inward, lastly, again postero-laterally
to the postero- lateral corner of the cheek. The occipital furrow ex-
tends laterally along the posterior border of the cheek near the mar-
gin as a deep furrow. Surface smooth.

Length of the glabella, 4. i mm. ; width at the broadest part, 4. i
mm.; at the narrowed posterior extremity, 2.4 mm.; width of that
part of the head included between the postero-lateral corners of the
fixed cheeks, 5.4 mm.; length of the fixed cheeks, 2.2 mm.

Locality and position. Soldiers’ Flome Quarry, Clinton Group.

BULLETIN OF THE LABORATORIES

Il6

GENUS DALMANITES, Emmrich.

X. Dalmanites Werthneri, sp. n.

^ General form of the body elongate-ovate, greatest breadth across the
posterior part of the cephalic shield.

Head convex, semi-circular, breadth about five-thirds as great as
the length; border extended in front into a semi-circular process,
which varies from forms in which it is scarcely evident, to those in
which it equals about two-fifths of the breadth of the anterior border
in its projection beyond the curve of the border itself, never as distinct
as in D. vigilans ; base about one-fourth as broad as the greatest width
of the glabella, or even less ; lateral borders broad, separated from the
cheeks by a distinct groove, produced posteriorly into rather long and
slender curving spines, which continue the curvature of the lateral
borders of the glabella.

Glabella large, depressed convex, widening in front to almost twice
its width at the posterior margin, divided into lobes by three pairs of
transverse furrows in addition to the occipital furrow, which is distinct
and continuous. All three furrows distinct at the sides, not
extending entirely across the glabella except in some specimens as
a faint depression. Anterior furrows deeper, situated a little anteri-
or to the eyes, giving to the frontal lobe a transversely elliptical out-
line; occipital ring narrow, without a spine as far as known. Eyes
very prominent, short reniform, containing obout thirty- five vertical
ranges of lenses, the middle ranges having six to seven each ; palpe-
bral lobe depressed, giving great prominence to the rim of the eyes.
Cheeks small, anteriorly quite prominent, posteriorly marked by a
deep, bordering groove, the continuation of the occipital furrow, mar-
gin flat.

Thorax with the axial lobe convex, widest at the sixth segment, its
greatest width about two-thirds that of the lateral lobe, or a little lar-
ger. The articulations curve forward a little near the middle and at
their junction with the lateral lobes ; articulations of the lateral lobes
traversed by a deep longitudinal furrow extending from the junction of
the anterior margin with the axil lobe, backwards along the anterior
margin of the articulation, at about one third the width of the articu-
lation, leaving it towards the extremities. From the imperfect preser-
vation, the exact method of leaving can not be determined.

OF DENISON UNIVERSITY.

II7

Pygidiiim broadly ovate-triangular, the lateral borders flattened, axial
lobe regularly tapering posteriorly, marked by about thirteen annula-
tions, which gradually decrease in size posteriorly and end in a spinose
elevation. This spinose elevation is often accompanied by an upward
deflection of the border posteriorly and terminates in a minute point at
the end of the border. Although the pygidia are very abundant no
spinose projection beyond the border has so far been observed. An-
tero-lateral margin of pygidium rounded, lateral articulations
about ten in number, all, except the last three, grooved like the ar-
ticulations of the thorax, becoming indistinct on the margin of the
pygidium.

Head irregularly pustulate (pustules small) except the anterior and
lateral borders of the head, which are minutely granular. Remain-
der of the body irregularly pustulate, pustules small, a single pustule
slightly larger in size on each segment of the'axial lobe of the pygid-
ium, inconspicuous.

Small specimen, length of body, about 25 mm.; breadth, 16 mm.;
length of head, 9 mm., breadth, 15 mm. Head (of usual propor-
tions), length, 12 mm.; breadth, 20 mm.; convexity, 4 mm.; breadth
of anterior lobe of the glabella, 10 mm.; of the posterior lobe, 5^
mm. Pygidium, length, 17 mm.; breadth, 22 mm.; breadth of
axial lobe anteriorly, 6 mm.

The furrows across the axial lobe are much more distinct at the
sides than at the middle, especially in the pygidium. The anterior
lobe of the glabella has near its posterior extremity a distinct, elongated
pit, which seems to be characteristic of this species.

Locality and position. Soldiers’ Home Quarries. Clinton Group.
(Named in honor of Mr. W. B. Werthner, who was present at the first
discovery of this species. Abundant in some localities.)

In connection with the minute forms described above from the
Beavertown marl, the following will be of interest :

GENUS ORTHOCERAS, Breynius.

Orthoceras inceptum, sp. n.

{Plate XIII, Pigs, i a, b, c.)

Shell very small and slender, enlarging from below upwards gradu-
ally, in one specimen from 4 to 5 mm. in a length of 10 mm., in others
more slowly. Transverse section almost circular, one diameter slight-

BULLETIN OF THE LABORATORIES

Il8

ly longer, or more elliptical ; length of the outer chamber not deter-
mined. Septa concave — six chambers occupying a length of lo mm.
in the specimen above mentioned. Siphuncle eccentric, nearer to
the centre than to the margin, narrow at the septa, expanding within
the chambers.

Surface apparently not preserved, specimens in the form of casts.
There are indications of longitudinal striae, preserved with various de-
grees of distinctness, in some worn specimens looking like rows of
small pits. Along one side of the shell, nearest the position of the
siphuncle is a narrow, raised, longitudinal line, laterally defined by
grooves which more or less coalesce anteriorly towards the annular rings
(septa), and thus produce interruptions along the line. The distinct-
ness of this longitudinal line is extremely variable, or perhaps is due to
the removal of some of the surface matter, because some of the best
preserved specimens are smooth, whereas those which are worn are apt
to present these features. ( Cf. O. jDuseri, Hall and Whitfield. )

Locality and position. Beavertown marl, Clinton Group. A speci-
men in the Ohio State collection, from Wilmington, Ohio, I refer to
this species.

Expt.anation of Plates.

Plate XIII.

Fig. I. Orthoceros inceptuni, n. sp ; a, lateral views b, views showing the
position of the siphuncle ; c, vertical section through the siphuncle.

Fig. 2. Aleristella iimbonata, Billings (sp ); a, lateral view; b. dorsal valve.

Fig. 3. Flatyostonia Niagarense. Hall; a, b, specimens referred to the Ohio
forms considered identical with the Indiana species, having the aspect of Holopea.

Fig. 4. Eichwaldia reticulata. Hall; a, dorsal valve ; b, ventral valve.

Fig. v Leptccna prolongata, n sp.; a, ventral valve; b, lateral view, outline.

Fig. 6. Zygospira inodesta, Say (sp ); dorsal valve.

Fig. 7. Ortliis biforata, var. lynx ( Von Buck), forma reversata; ventral
valve.

Fig. 8. Orthis biforata, var. lynx ( IPn Bitch), forma Daytoncnsis; ventral
valve.

Fig. 9. Atrypa nodostriata. Hall; ventral valve.

Ing. 10. Ortliis hybrida, So^ivcrby; a, dorsal valve ; b, lateral view, drawn for
the outline only.

Fig. II. Orthis elegantula,_ Dalinan; a, dorsal view; b, lateral view, drawn
for the outline only.

Fig. 12. Orthis fiabella, Sowcrby; a, ventral valve; b, dorsal valve.

Fig. 13. Orthis Daytoncnsis, n. sp.; a, dorsal valve ; b, lateral view, drawn for

OF DENISON UNIVERSITY.

II9

outline only ; c, a few of the radiating stride ; d, occasional appearance of the sur-
face characters.

Fig. 14. Pterinca brisa, Hall; a, b, views of different left valves referred to
this species ; b, taken from a cast.

' Fig. ic;. Orthis fausta, n. sp ; a, dorsal valve; b, ventral valve ; c. lateral
view ;^^d, a few of the striae.

P'ig. 16. Orthis fatisla, n. sp.; a, dorsal valve ; b, some of the striae of the
form aciito-plicata .

Fig. 17. Orthis elegant ula. var. parva. ii var.; a, ventral valve; b, lateral

view of the same. .'W. 2:^

P'ig. 18. Biicania exigiia, n. sp.; a, view from above ; b, lateral view, the
expansion of the aperture not well brought out ; c, lateral view of another speci-
men ; d, another view of the same.

Fig. 19. Bcllei'ophon Jiscello-striatiis. n. sp ; a, lateral view ; b, c, d, views of
.the same ; e, a part of the carina, with a few of the nearest striae.

P'ig. 20. Orthis Day tonensis., n. sp.; a, ventral view; b, interior view of the
same.

P'ig 21. Orthis Daytonensis, n. sp ; lateral view of a specimen presenting
both valves.

P'ig. 22. Platyostoma Niagarensc, Hall; a, lateral view ; b, view from above.

P'ig. 23. Acidaspis; part of the head.

P'ig. 24. Calymene; part of the head, partially restored.

P'ig., 23. Calymene Blitmenbachii? Brongniart; head with a few of the
thoracic articulations attached.

Fig. 26. Lichas breviceps, Hall; a, glabella, not typical ; b, typical glabella
of Ohio form ; c, surface of the latter, variously magnified ; d, pygidium ; e, gla-
bella of a specimen from New Carlisle.

Plate XIV.

Fig. I. Ilhenus Madiso/iianus, Whitpeld ; a, view of a pygidium from above;
b, lateral view of the sam.e.

P'ig. 2. Ilhemis ; a, view of pygidium similar in some respects to that of
/. Madisoniamis ; b, lateral view of the same.

P'ig. 3. Arionellus ? ; view of the glabella and fixed cheeks.

p'ig. 4. Plhoiiis Daytonensis, Hall and Whitfield ; a, view of a pygidium ;
b, lateral view of the same.

Fig. 5. Bathyw'tis ; view of a glabella, the curvature of the rim of the an-
terior border not represented.

Fig. 6. Ilhemis Daytonensis, H. and IF.; movable cheek, view obliquely
from below.

P'ig. 7. Illtcnns Daytonensis, H. and W.; a, lateral view of a head, the asso-
ciated movable cheek figured ; b, view of the glabella from above ; c, view of the
same from behind.

P'ig. 8. Nucula minima, n. sp.: a, view of the anterior regions; b, lateral

120

BULLETIN OF THE LABORATORIES

view ; c, view of the regions posterior to the beaks ; all views magnified six diam-
ters,

F^'g. 9. Illccniis ambigtms, n. sp.; a, view of a pygidium seen from above ; b,
lateral view of the same.

Fig. 10. Illmius ambigiius, n. sp.; a, lateral view of a head, the associated
movable cheek figured ; b, posterior view of the glabella ; c, view ot the same
from above.

Fig. II. lllccmis ambigims, n. sp.; movable cheek of unusually large propor-
tions.

Fig. 12. Gmmmysia Caswelli, n. sp.; a, lateral view of the shell, anterior
definition too sharp ; b, view of the same from above.

Fig. 13. triplesiajius, n. sp.; a, view of one of the valves; b, lat-

eral view of the same shell.

Fig. 14. triplesianus, n. sp.; view of the other valve from a different

specimen.

Fig. 15. Strophostyhis cyclostomus, Hall; lateral view of a specimen.

Fig. 16. Trochoncnia nana, n. sp.; two views, magnified to eight-thirds and
four-thirds of the original size respectively.

Fig. 17. Cyclo7'a alia, n. sp.; a, lateral views of specimens showing variations
in the elevation of the spire ; b, view of the umbilicus of a specimen ; all views
magnified two diameters.

, Fig. 18. Raphisioma affijtis, n. sp ; view from above, and also a lateral view,
the umbilicus being directed upwards.

Bullelii] of the Laboratories of Denisoij University. •

PLATE Xlll.

Bulletifj of the Laboratories of Denisoq University,

PLATE XIY.

VII.

A COMPEND OF LABORATORY MANIPULATION.

It is the design of the series of papers, of which this is the first, to
present in concise form the methods of investigation which have proven
themselves of greatest service in the laboratories of this country and
Europe. No attempt at originality or completeness is made, but only
such methods as have been experimentally proven useful will be admit-
ted, while free use will be made of the modern text-books of Fol and
Hussak.

• It is acknowledged by all students that the proper method of re-
search is the first essential to the prosecution of any line of investiga-
tion, and it is often stated that he who spends but half the time allotted
to a given study in experimentally learning the best manipulation to
employ, need not regret the time so spent.

The present paper deals with lithological appliances and methods
and is supplemented by a condensed translation and adaptation of Hus-
sak’s Einleitung.” No apology is necessary for reducing the for-
mulae to the system in vogue in this country nor for giving i^rominence
to the subject of lithology, in view of its rising importance and increas-
ing recognition.

CHAPTER I.

Lithological Manipulation.

A. Rock Sections.

In no department of geology has there been so great an advance
of late in this country as in the study of the intimate structure of rocks
by means of thin sections. The science of lithology is rapidly
evolving from a chaotic condition and assuming the similitude of a sys-
tem. Although the pursuit of this study has been confined to a limit-
ed circle and it has scarcely appeared in our literature, much may be
expected in the near future.

122

BULLETIN OF THE LABORATORIES

The impetus given years 2igo hy Zirkle, in his ‘‘Microscopic Pe-
trography,” has slowly become apparent. Hawes, in his work upon
New Hampshire lithology, contributed substantial material to the same
science, while the more recent reports of the Wisconsin geological
survey afford evidence that the work is going on. Several of the
State geological surveys are now in the midst of investigations in this
direction the results of which may be looked for with great interest.
The United States surveys are not behind in cultivating the promising
field.

Great as is the promise of research in this direction, we are equally
interested to observe that the introduction of the new method of study
of rocks is to a degree revolutionizing the study of geology. The
same methods which have so greatly augmented the disciplinary value
of biology by connecting histological and laboratory practice with its
study, are introduced into the courses in geology and the student is
taught to see th7mtgh^ as well as to look at, rocks and minerals.

The study of a rock or mineral involves, first, the investigation of
the origin, age, and relations of the rock, which invoke respectively
the sciences of geotechnical, historical, and stratigraphical geology;
second, the study of the rock itself, which may be carried on by means
of chemical and physical tests. Under the latter head come crystal-
lography and physical mineralogy. The chemical examination in-
volves the application of heat, as in blow-pipe analysis, or of chemical
reagents in the wet way.

The physical examination of minerals may be conducted micro-
scopically or macroscopically, depending upon the employment or non-
employment of aids to ordinary vision. Ordinary physical mineralo-
gy is occupied with such of the optical or other characters of minerals
as oan be made out with the unassisted eye.

In order to prepare a mineral or rock for microscopic examination
it must, in most cases, be reduced to a transparent condition in order
that it may be studied by transmitted light. The facts which can be
obtained by the microscopic examination of opaque masses in reflected
light, are few and unimportant:

A rock may be reduced to a powder and mounted in a transparent
medium and many of its elements detected by microscopic examina-
tion of the angles and surfaces of the fragments. In this 'way parti-
cles too small for measurement by the ordinary goniometer may be de-
termined, Such of the resulting particles as are transparent may

OF DENISON UNIVERSITY.

123

be optically examined, though there are many opportunities for error.
It is recommended that rocks of a rather finely granular structure be
examined in this way with reference also to the specific gravity. A
fragment of suitable size is reduced to a powder, the fineness of which
may vary with the size of the granular elements in the sample. The
powder is then assorted under water by agitating repeatedly in a bottle
and hastily pouring off the fluid, leaving the part first to settle and re-
peating the process as often as any separation is possible. Denser
fluids (See Hussak Anleitung, p. 51,) may be used wdth advan-
tage in some cases. By mounting different parts of the powder
thus sorted separately or under separate covers upon a single glass
slip, interesting qualitative and even approximate quantitative results
may be obtained.

Comparatively few minerals or aggregates are sufficiently transpa-
rent to permit of optical examination by transmitted light. A few of
these, as mica, gypsum, calcite, dolomite, etc., are adapted for study
without other preparation in any way. In cases where the cleavage
is irregular and does not permit the breaking out of tabular plates it
becomes necessary to mount the irregular fragments in a highly refrac-
tive medium, such as balsam, between glass slips, and thus to elimi-
nate as far as possible the dispersion and irregular refraction. Even
then the results are often unsatisfactory. Sands and other fragment-
ary rocks may be examined by the following method, suggested by
Thoulet.

The powder or sand is mixed with about ten times its volume of
zinc oxide, then silicate of potassium is stirred in till the whole assumes
the consistency of a stiff broth. This, while still soft, may be pressed
into a mold, formed from a section of a glass tube glued to a slip.
When set, the resulting cylinder is removed and fastened to a slip of
thick glass and ground in the way described beyond for compact
rocks.

When a rock or mineral is not transparent and does not admit of
breaking into sections of suitable thinness with the hammer, it becomes
necessary to cut or grind a section of sufficient transparency and then
mount it between glass in Canada balsam. Before beginning this
somewhat tedious process the student should provide himself with the
following outfit : ( i ) A number of thick squares of plate glass about

one half inch thick and two inches square, these being ground on the
edges in order to avoid cutting the fingers ; (2) several dozen slips of

124

BULLETIN OF THE LABORATORIES

thin perfect glass for mounting the sections, the size preferred being
45 by 25 mm. and is furnished by any dealer in microscopes; (3) a
corresponding number of covers of thin glass, square in shape and
large enough to extend nearly across the slip; (4) ajar of balsam nearly
solid or of the consistency of honey and lumps of solid balsam, (the
balsam thould be in a wide-mouthed bottle covered with a protecting
shield or glass stopper, through which extends a dipping rod); (5) sev-
eral grades of emery powder, it being convenient to hd:ve numbers o,
and I, and emery flour, as well as a small quantity of emery slime. ^
This last is not kept by ordinary dealers and is made by decanting off
the finest impalpable powder during the grinding of other grades. It
may be secured of Julien, of New York, or through Bausch & Lomb,
of Rochester; (6) an alcohol or gas lamp; (7) a heating table or tri-
pod with brass plate, for heating the slides ; (8) a number of spring
clothes pins, with the lips filed flat, to hold the cover glasses while the
balsam drys ; (9) a bottle of solution for cleansing the glasses, which
is prepared from sulphuric acid and chromate of potash ; (10) a contri-
vance of some sort for grinding or sectioning the rock. The simplest
way is, after breaking as thin a fragment as possible from an unweathered
sample, to grind one side of the fragment upon a smooth iron surface with
coarse emery and water until a plane surface is secured as large as a quar-
ter or larger. The surface is then ground with emery flour upon a large,
smooth plate of glass, after which a polish is secured by long rubbing
on a second plate with emery slime. The surface thus prepared is
glued to one of the squares of plate glass with balsam. The best
results are secured by using balsam which is quite hard but not yet
brittle ; it should yield to the nail with difficulty, but should not shiver
into fragments. A small piece is placed on the cleaned surface of the
square and set on the brass plate of the tripod over the flame of the
lamp. The chip of rock is also heated at the same time. When
the balsam has become thoroughly fluid, but before bubbles appear,
the section is pressed firmly down upon the balsam and as much of it
pressed out as possible. Care should be taken that no bubbles or im-
purities find their way between the section and the glass. A weight
or spring may, in some cases be necessary to prevent the slightest ele-
vation of one side of the chip from the glass square. The balsam
will set very quickly and, if the heating has been slow enough, will
have become tough — it should no longer yield to the nail. The older
lithologists advise the use of soft balsam, which is heated until it ac-

OF DENISON UNIVERSITY.

125

quires the proper consistency before each mounting, in a spoon, but
there are many objections besides the tedious process involved. When
any number of slides are to be made there is economy in having bal-
sam of the proper sort at hand and if some becomes brittle it may be
melted with some which is yet too fluid. It is desirable also to per-
form the same part of the process with a number — say a dozen — sam-
ples at once, as it saves time and the chances of accident are fewer,
provided care be taken to avoid loosing the identity of the specimens.
After the chip has been glued to the glass square the former is ground
carefully with coarse emory of various grades until the section shows
signs of falling to pieces, it is then put upon the flour and slime plates
in succession. Great care must be used to prevent the accidental
mixture of coarse emery or gritty grains with the emery flour or slime,
as one grain of coarse grit may suffice to destroy the section just when
completed. When the section is judged thin enough, it is proved
by cleaning the square and laying it over print which should be clearly
seen through the section. The superfluous and soiled balsam is care-
fully cleaned away from the section and it is placed on the heating
table on which are also laid the slip and cover glasses. When the bal-
sam is fluid, a small fragment of somewhat more fluid balsam than that
previously used is placed on the glass slip and the thin section is
pushed off the plate glass square with a blunt needle, the cool needle
adheres to the section and the latter is removed to the now perfectly
fluid balsam on the glass slip. The warm cover glass is now quickly
placed over the section which has been completely immersed in the
medium. Care must be taken that a sufflcient quantity of balsam is
used to completely fill the space between the slip and the cover and
also that no bubbles arise to obscure the field. If all has been suc-
cessful the spring clips are applied and the slide is placed aside to dry
without attempting to clean away the superfluous balsam. In a day
or two this will be hard enough to be readily removed with a knife and
the slide may be cleaned with a soft cloth wetted with alcohol, care
being taken that the balsam under the cover is not attacked by the al-
cohol. The slide is then ready to label in any convenient way, the
number of the corresponding hand sample being in every case attached
to the slide.

The process above described is less tedious than might be supposed
but can be materially shortened by the use of a lithological lathe pro-
vided with lead and iron horizontal laps. The accompanying wood

126

BULLETIN OF THE LABORATORIES

cut illustrates the form of lathe used for this purpose in our own labo-
ratory. It was manufactured at the suggestion of this department
and is not only more convenient and elegant, but less expensive than
any other lathe at present in the market. It is constructed by W. F.
and John Barnes Co., of Rockford, 111.

In the study of the section thus prepared a microscope is used
which is especially arranged for this purpose. The appearance of
such an instrument is illustrated by the accompanying figure which

OF DENISON UNIVERSITY.

127

represents the polarizing microscope prepared by Bausch and Lomb,
Rochester, N. Y. , while figure i. of plate XI gives a diagram of the
optical parts, etc., of the Fuess-Rosenbusch stand in use in Germany.

The rotating stage is centered and graduated to record the angular
position of the slide. The polarizer (rr) is placed below the stage
and consists of a Nicols’ prism set in a. rotating cylinder. Above it is

128

BULLETIN OF THE LABORATORIES

a condensing lense for making the rays convergent. The light is
polarized in one plane by the polarizer and (the condenser being re-
moved) passes through the section placed over the aperture in the stage.
The resulting image is now magnified by the microscope in. the usual
way. Above the ocular is placed the analyser, consisting of a
Nicol’s prism set in a revolving cylinder with a graduated limb. This
prism serves to cut off all the rays polarized in one plane by the lower
Nicol when its axis is at right angles to that prism. If, however, the
interposed mineral section is double refractive and rotates the plane of
polarization of the light, this fact is indicated by the fact that the field
does not appear dark when the Nicols are at right angles, but at some
other angle which enables us to ascertain the amount of rotation pro-
duced by the mineral in question. A quartz plate (zz) is inserted
above the objective and serves to discover the slightest double refrac-
tion. An artificial calcite twin, known as the Calderon plate, is in-
serted in one of the oculars. If the mineral examined be not isotro-
pous the two parts will be unequally dark, thus enabling us to distin-
guish the optical characters by a most sensitive test. A plate of cal-
cite, set in a cork ring, is also used between the ocular and analyzer.
The interference figure produced by the calcite now is superposed upon
the mineral section and may or may not be distorted by the action of
the latter, affording another criterion by which to determine the min-
erals.

B. Micro-chemical Methods.

In the application of chemistry beneath the microscope, tests of
prime importance are derived from the solubility of the various parts
of a section and the forms of crystals formed from an evaporated pre-
cipitate after a reaction is accomplished.

In order that the tests, may be applied to but a single crystal of a
section, it is necessary to perforate the cover glass with a minute open-
ing, thus preventing the uncertainty otherwise unavoidable. An or-
dinary cover glass is coated with wax and a minute perforation is made
with a needle, exposing the glass, which is then subjected to the action
of hydrofluoric acid until the glass is eaten through by a perforation
less than a millimeter in diameter. The section is then covered and
the opening is brought directly above the crystal to be studied. The
balsam is removed by alcohol and the surface of the crystal is thus ex-
posed to the action. In the case of reagents giving off corrosive

OF DENISON UNIVERSITY.

129

fumes, the objective may be protected by a thin glass cover tempora-
rily fastened to the end by glycerine.

As an example of the micro-chemical process we may mention the
process of distinguishing apatite from nephelin. If the grain of
apatite can be isolated it is dissolved in a concentric nitric acid solution
of molybdate of ammonia. As the solution is slowly affected, a
multitude of yellow octahedrons of 10 Mo O3 + PO4 (NH4)3 appear
about t^ie edges. This detects the phosphoric acid. The lime may
be demonstrated by dissolving the grain in nitric acid, to which is then
added a drop of sulphuric acid producing small crystals of gypsum.

In case the questionable grain is in a section the acids may be
applied with a glass rod and then removed by a pipette to a glass slip
and there evaporated.

Nephelin fails to produce the reactions described but its solution
in concentric hydrochloric acid affords, on evaporation, minute cubes
of common salt which are very readily recognized.

Boricky has applied Fluo-silicic acid in the micro-chemical analysis of
many minerals. The reagent must be chemically pure and about
13 per cent, strong. It cannot, of course, be preserved in glass
vessels. Its availability arises from the fact that nearly all rock-
forming minerals are attacked by it and the resulting compounds afford
characteristic crystals.

A slide is covered with a thin protecting layer of balsam and upon
this the particles to be examined are placed. When the substance is
very slowly affected the best results are obtained by applying the
reagent to the section itself If the mineral is easily dissolved the
various components appear approximately in their relative proportion
in crystals of various form. In cases where the mineral is but slightly
attacked, some of its components may first separate and thus make
necessary a repetition of the process, or it may be faciliated by first
dissolving these soluble substances in fluoric acid. The fluo-silicates
crystallize most perfectly when evaporated and the watery solution
permitted to again evaporate on a second slide.

1. Fluo-silicate of postassium crystallizes in the isometric system,
usually in i-i in skeleton groups, also in i, and I. The reaction is
masked by presence of sodium, when apparently rhombic crystals i-n . m-i
are formed.

2. Fluo-silicates of sodium give short hexagonal columns with *0,

130

BULLETIN OF THE LABORATORIES

I, and i-2. Incomplete crystals are barrel-shaped, presence pf cal-
cium increases the size.

3. Fliw-silicate of calcium occurs in peculiar, long lanceolate
crystals, often in rosettes. The angles and edges are not sharp.
Monoclinic, easily soluble in water.

4. Fluo-silicaie of magnesium appears in rhombohedrons the angles
of which are truncated by oR, and in combinations of R . i-2 or
R. i-2 . oR. It often appears in rhombohedrons deformed in one angle
or in cruciate or pectinate forms.

Ferric and maganesic compounds can hardly be distinguished from
magnesium fluo-silicate, and strontium compounds resemble fluo-
silicate of calcium.

5. Lithia compounds appear in obtuse hexagonal pyramids, while
fluo-silicate of barium occurs in excessively minute needles.

The fluorides of iron, magnesium, and maganese may be dis-
tinguished by subjecting - them to the action of chlorine gas, which
changes the color of the iron compound to citron yellow, of the
manganese to reddish, while the fluoride of magnesia remains colorless.

Behrens gives the following method which, when carefully followed,
is exceedingly delicate : —

The sample to be studied is isolated and pulverized and is placed in
a covered platinum capsule not more than i cm. in diameter into which
a few drops of fluoric acid, fluoride of ammonium, and concentrated
hydrochloric acid have been placed, evaporate, and, if necessary,
repeat the operation. The dried mass resulting is evaporated with
sulphuric acid nearly to dryness, when gray fumes are formed. Add
water and again evaporate so that for each milligram of the powder a
centigram of fluid is produced. A drop of this fluid is now placed
on the slide with a capillary pij^ette and, after protecting the objective,
is examined for calcium. If calcium is presant, evaporation produces
crystals of gypsum (I . i-f ; i .) On the margin of the drop charac-
teristic swallow-tail twins may be found. .0005 mg. of lime can be
detected in this way.

A drop of platinum chloride is now added and, if potassium was
present, strongly refractive octahedrons or trillings or quadrillings
appear.

Sodium is detected by cerium sulphate, a saturated solution of which
is placed on the slide near the drop to be examined and connected
with it by a capillary glass thread. In the drop of the reagent there

OF DENISON UNIVERSITY.

I3I

appear desmid-like aggregates of cerium sulphate and on the margin a
brown cloudy zone of double salt of soda. Excess of sulphuric acid
prevents'the reaction.

Magnesium is detected by salt of phosphorus. The drop, before
tested for possium or aluminum, is neutralized with ammonia and in a
drop of water placed at a distance of about i cm. is placed a grain of
salt of phosphorus and the two drops connected as before. The re-
sult is the production of double, forked crystalloids similar to those
found in natural glasses or well developed hemimorphic twins of
ammoniated magnesium phosphate.

Aluminum is detected by touching the drop with a platinum wire
dipped in caesium chloride. Translucent octahedrons of caesium
alumn are formed, or more rarely i . Ti. If the solution of the
mineral is concentrated, dendritic forms simply are formed and water
must be added.

Similar tests are proposed for the detection of other elements but
the above are of most general application.

C. Use of the Polarizing Microscope.

Ordinary polarized light is produced by placing the analyzer above the eye-
piece in such a position that its Nicol’s prism stands at right angles to that in the
polarizer below the stage. The field now appears totally dark, inasmuch as the
only rays permitted to pass through the polarizer are extinguished by the analyzer.

All minerals are either simply or doubly refractive, and the former may be rec-
ognized as amorphous (like glass) or belonging to the isometj'ic crystal system. lir-
as much as the elasticity of the ether in either case will be the same in any direction
in such minerals, they do not interfere with the rays which pass through them, hence
between crossed Nichols any section of such minerals remains constantly dark,
even though the section be passed through a complete revolution by rotating the
stage — in other words, the mineral is isotropous. Double refractive minerals, in
sections taken in some directions, become colored in certain positions between
crossed Nicols. Such sections become perfectly dark twice in one complete rev-
olution. These colors are due to interference of the rays brought about by the
double refraction.

Optical uniaxial crystals are those falling in either the tetragonal or hexagonal
systems. In such crystals there is but one direction in which there is no double
refraction, i. e. that parallel to the vertical axis c, which, in this case, corresponds
to the optical axis. The elasticity of the ether contained in the crystal is differ-
ent in directions parallel and at right angles to the main axis. a= the a,xis of the
greatest elacticity and c— the axis of least elasticity. exponent of refraction

in the ordinary ray (that is, the one passing parallel to the optical axis and vibrat-
ing at right angles to the fundamental section. e= exponent of extraordinary ray

132

BULLETIN OF THE LABORATORIES

(/. e. that passing at right angle to the optical axis and vibrating in the principal
section. If the axis c coincides with the optical axis a and e the mineral is neg-
atively double refractive, while if c= c and wc^e, the mineral is positively double
refractive. A thin section of a crystal of either the tetragonal or hexagonal sys-
tem, if ^ basal, (£ e. parallel to O) acts as though isotropous and remains dark in
all positions between crossed Nicols. On the other hand, sections taken vertical
to O, or parallel to one of the prismatic faces, are dark fwice in a revolution and
these points occur when the sides of the section are parallel to the principal section
of the NicoPs prisms. In such a cas^e the extinction is said to be perpendicular
or parallel to the crystallographic axis. Sections inclined to the vertical axis or
such as are parallel to a pyramidal face are extinguisned parallel to the vertical
axis, but not necessarily to all the sides. Whether the mineral proven to be uni-
axial is hexagonal or tetragonal can only be discovered by ascertaining the num-
ber of sides of a section transverse to the vertical axis.

In biaxial minerals there are two directions without double refraction. Three
axes are assumed, each of which is at right angles to the others and has a differ-
ent amount of elasticity of the ether. These elasticity axes are lettered a, h and
C, in order of elasticity. Two of the optical axes do not correspond with the
crystallographic axes, but the two sets of axes form with each other larger or
sm iller angles. The line which bisects the acute angle = acule bisectrix, that
which bisects the obtuse angle = obtuse bisectrix. The optical axes and both the
acute and obtuse bisectrix lie in the same plane, called the optical plane, perpen-
dicular to which is the optic normal. The axis of intermediate elasticity (6) co-
incides with the optic normal, while the axes of least and greatest elasticity may
coincide with either bisectrix. If a coincides with the acute bisectrix, then c co-
incides with the obtuse bisectrix and the mineral is negative. If, on the other
hand, c coincides with the acute bisectrix and a with the obtuse, it is positively
double refractive. a, /3, y are the indices of refraction corresponding to the three
axes of elasticity.

In the case of minerals of the Orthohombic system the three axes of elasticity
a>&>-C correspond with the crystallographic axes a, b, and c, but not necessarily
in such a way that a always corresponds to a, etc. a and c are always bisectrices
and the optical plane is always parallel to one of the three pinacoids.

The following are possible i

If Opt. plane = O, a=a, b-=c I / y.

a=c, b=a ) “

If Opt. plane =i-i,c^=a, a=c 1 i y,

C^=c, a=a /

If Opt. plane = i-L c'=a, b=c 1 .. y-

c'=c,b=a}‘‘=^

Sections parallel to one of the three pinacoid surfaces (usually rectangular) extin-
guish perpendicularly, i. e. become dark between crossed Nicols when one side of the
rectangle or one of the pinacoid cleavage lines is parallel to the main section of the
Nicol. Distinguished from isometric minerals by the fact that basal sections (par-
allel O) are not isotropous Only such sections are isotropous as are exactly verti-
cal to the one or the other of the optical axes, which would be the case, accord-

OF DENISON UNIVERSITY.

133

ing to the position of the optical plane, in the plane l-I, i-i or a prismatic surface.
Hence isotropous sections are more rare and less regular than in isometric minerals.
Sections parallel to the vertical axis in the zone i-I, i-i extinguish perpendicularly.

In monoclinic minerals only the ortho- diagonal {b) coincides with one of the
axes of elasticity, the other axes of elasticity form angles with a^ and of . The op-
tical plane is either parallel or at right angles to the plane of symmetry i-i.

If optic plane = i-I the acute bisectrix = C) ^
or “ “ = a i

then c and a are inclined toward C and a.

If optic plane is at right angles to i-i.
the acute bisectrix = b=a

“ “ =b=C '

or the obtuse “ = b=a

“ ‘‘ “ = b=c

then h and c or b and a are inclined toward c^ and a^.

As a result of the inclination of the axes of elasticity to the crystallographic
axes certain of the longitudinal sections are not extinguished when the crystallo-
graphic axes coincide with the principal plane of the Nicol’s prism. Sections in
the zone O. i-i, all are extinguished perpendicularly, for in this case the orthodi-
agonal coincides with an axis of elasticity.

In Triclinic minerals none of the three axes of elasticity coincides 'with the
crystallographic axes. All sections parallel to the three pinacoid surfaces, there-
fore, are obliquely extinguished. The angle of extinction in the planes O and
i-i is known for most triclinic minerals and forms a ready means of determining
these minerals. In thin sections the shape of the section will generally make it
clear whether it is or is not parallel to a pinacoid. Accurate measurements of the
angle of extinction must be made in cleavage plates parallel to i-i and O.

Twinning Phenomena.

Twins in the regular system cannot be recognized by the polarizer. Twins in
the tetragonal and hexagonal systems cannot be recognized unless the axes of the
twins are inclined toward each other. If one individual, in such a case, appears
dark between crossed Nicols the other may appear colored.

In some cases a crystal individual is made up of alternate lamellae of the same
mineral in different position relative to the axis. Such aggregates are called poly-
synthetic twins. In plagioclase feldspar, calcite and disthene this frequently oc-
curs. In such minerals the adjacent lamellae will not be extinguished simultane-
ously under polarized light.

In the rhombic system the twinning plane is usually one surface of a brachy-
dome, a pyramid or a prism. Pleochroism in colored minerals assists in deter-
mining the relation of twinned crystals.

In the monoclinic system the plane is often i-P.

In the tr-iclinic system the polysynthetic form appears very frequently. In
plagioclase the twinning plane is generally i-i (albite type). Sections at right
angles to this plane in the zone O. i— i always exhibit the banded colors in polarized
light. Twins of this type are impossible in the monoclinic system, because the

134

BULLETIN OF THE LABORATORIES

plane corresponding to i-i = i-K and coincides with a symmetiy plane, hence coal-
escence in this way would not produce twins. A second type is the pericline type
in which the twinning plane is at right angles to the zone O, i-I.

Pleochroism.

Double refracting minerals have the property of affording different colors when
looked through in different directions corresponding to the axes of elasticity. In
optically uni-axial crystals there are two such directions {i. e. the minerals are di-
chroic) and the color afforded by looking through in the direction parallel to the
vertical axis is called the basis color, that appearing when looked through at right
angles to this the axial color. A section of a uniaxial crystal will show no
change of color when rotated above the polarizer (analyzer being removed) if the
section is parallel to the vertical axis.

In tetragonal and hexagonal minerals, therefore, the directions where greatest
change of color occur coincide with the two axes of elasticity, in the orthorhombic
system they coincide with the three crystallographic axes as wel', but in the mono-
clinic and tnclinic this coincidence seems not to occur.

Use of convergent Polarized Light.

The occular is removed and a condensing lense is placed above the polarizer,
between it and the object. Interference figures of a nature varying with the
character of the mineral now appear. In regular and amorphous minerals no
such figures are produced. The same is true of sections parallel to the vertical
axis of the hexagonal and tetragonal minerals. In the transverse (isotropous)
sections of tetragonal and hexagonal minerals an invariable dark interference cross
lies in the centre of the field. If the sections is oblique, the cross falls at one
side of the centre but is not otherwise altered. A rotation of thesta^e causes the
cross to apparently revolve in the same direction. If the section is so oblique
as to fall outside the field a rotation will bring first one limb and then the other
into view.

A section of biaxial crystals taken perpendicularly to the bisectrices and
placed so that the optical plane coincides with the principal section of the Nicols
shows two closed curves enclosing the axial points. These curves are bordered
by other curves and crossed by a dark cross. The smaller limb of the cross
passes through the axial points and indicates the position of the optical axis
plane. The broader limb of the cross is at right angles to it. When the
stage is revolved the cross does not remain invariable but is altered to form two
hyperbolas which move about the aixial points and again form a cross after a
revolution of go°.

The above account, condensed, in the main, from Hussak, will serve to in-
troduce the tables, while the student may be referred for more full explanations to
the works of Rosenbusch, Zirkle, Fouque^ and Levy, Cohen and especially
Hussak’s “ Anleitung zum bestimmen der gesteinbildenden Mineralien,”

D. Recapitulation of civiracters of the various crystal systetns.

I. Amorphous and regular minerals are distinguished from all others by re-
maining dark in all positions between crossed Nicols, while the later may be

OF DENISON UNIVERSITY.

135

distinguished from the former, even in sections, by the regular contour and
cleavage.

2. The remainder of mineral species are anisotropous. Tetragonal and
hexagonal minerals have different elasticity in directions parallel and perpendicular
to vertical axis c. Rectangular or hexagonal longitudinal sections are extingui.shed
perpendicularly. In convergent polarized light transverse sections exhibit a
fixed axial cross, while in longitudinal sections no interference figures appear.
Sections obique to the axis show lateral displacement of the optic axis. . The
fixed axial cross appears to move- in the same direction as the stage when revolved.
Hexagonal are distinguished from the tetragonal forms by the hexagonal and
twelve-sided transverse sections.

3. The remaining minerals are optically bi- axial, and in those sections which
are isotropous a black band appears in convergent polarized light, which appears
to move in a direction opposite to the stage. The axial point may lie within or
out of the field (depending on the inclination of the section.) If the band
(hyperbola) is bordered with red on the convex side and blue on the concave the
dispersion of the axes—py>v, if the reverse p<y.

Orthorhombic minerals have both optic axes in a plane parallel a pinacoid.
In sections at right angles to the vertical axis extinction takes place parallel and
perpendicular to the sides. In sections parallel to the vertical axis extinction is
also perpendicular. No interference figure in the third pinacoid section in con-
vergent polarized light.

In Monoclinic minerals one axis of elasticity coincides with the orthodiagonal,
the others in the symetry plane i-i or perpendicular to it. Sections perpendicular
to the vertical axis are perpendicularly extinguished. Sections parallel to the
vertical axis if in the zone O . i-F are extinguished perpendicularly, sections
parallel to i-i^are obliquely extinguished. If the optical axial plane is parallel to
i-i none of the pinacoid sections exhibits perpendicular displacement of a bisectrix,
but the interference figure is displaced toward the vertical axis.

In Triclinic minerals neither of the axes of elasticity coincides with the crys-
tallographic axes. The optical axial plane is not perpendicular to pinacoid sur-
faces. No pinacoid section is perpendicularly extinguished and none of these
sections exhibits perpendicular displacement of the bisectrix.

Explanation of Plate XI.

Fig. I., Diagramatic section of Lithological Microscope as manufactured by
Fuess of Berlin. [See text.]

Fig. 2. Reflecting goniometer of Wollaston, for measuring angles of macro-
scopic crystals.

Fig. 3. Polysynthetic twins of plagioclase ; section parallel i-I. (From
Hussak.)

Fig. 4. Plagioclase twinned according to both the albite and pericline type ;
section parallel i-I. (From Hussak.)

Fig. 5. Diagram illustrating relation of the optical axes etc., in twins.
(In A X = Normal.) It may be more clearly illustrated as follows : — A thin
plate of gypsum is taken parallel the principal clinodiagonal, Out of this a

136

BULLETIN OF THE LABORATORIES

rhombic piece is obtained by using the conchoidal fracture parallel the ortho-
pinacoid and the satiny cleavage parallel to the -)- hemipyramid. The obtuse
angle =113° 46^ and the acute = 65° 14''. In as much as the optical axes in
gypsum lie in the clinodiagonal terminal plane, the surfaces of the plate may be
taken as the plane of the optical axes. The conchoidal fracture corresponds with
the main axis, and the optical axes above and anteriorly form angles of 23° and
83°. These are represented. By bisecting the acute and obtuse angles we may
secure the bisectrix (axis of least elasticity) and the optical normal (axis of
greatest elasticity) respectively. The bisectrix iorms an angle with the longer
diagonal of the plate of nearly exactly 20°. Every ray entering the plate per-
pendicularly is polarized, forming one ray vibrating in the plane of the bisectrix
and another in the plane of the optical normal. In a drawing of the exact shape
of the plate these lines are drawn and, in addition, the whole area checked into
squares by lines parallel to the bisectrix and the normal (on both sides.) The
plate is laid upon the drawing and both are bisected parallel the main axis and
one piece is revolved 180° and united by its other edge with the second. The
result is an artifical twin of gypsum with the optical determinants all indicated in
each (Rosenbusch.) The same method may be applied to illvistrate other twins.

6 A. Orthoclase twins of Carlsbad type.

B “ Banover type.

7. Polysynthetic twins of calcite in marble.

8. Section of augite parallel to i—i, showing zonary structure. (Hussak.)

9. Micro- crystals of gypsum (twinned.)

10. Inclusions showing Auction structure.

II Hornblende crystal with opaque altered margin. (Hussak.)

12. Diagrams of interference Agures in convergent polarized light.
(Adapted from Fouque^.)

The polarizer and conden.s.or are used, but the occular is removed and the
Nicols are crossed. In regular and amorphic minerals no Agure is seen. In
uniaxial crystals in isotropous sections there appears a Axed axial cross with more
or fewer concentric colored rings. These latter vary with the thickness of the
section. If the section is not exactly at right angles to the main axis the inter-
section lies out of the centre and revolves with the motion of the section. If
the inclination is still greater the intersection falls beyond the held and aTevolu-
tion of 90° brings Arst one and then the other limb of the cross into view,
I A= a section slightly oblique, I B is the same section revolved 45°, and I C is
revolved °90. Biaxial crystals, if taken perpendicular to bisectrix or normal,
and if so placed that the opical axis plane coincides with the principal section of
the Nicols, show an interference Agure consisting of two separate systems of curves
whose foci correspond with the two axes. These curves are surrounded each
by a lemniscus and a black cross appears with a narrow arm passing through the
foci and a broader band between them (II A.) The slender band represents the
position of the optical axis plane. When the section is revolved the cross alters
its form and at 45° becomes an hyperbola passing about each focus while at 90° the
cross reappears but in a position transverse to that formerly occupied.

Bulletiij of the Laboratories of Denisoij University.

PLATE XI.

TABLES FOR THE DETERMINATION OF THE PRINCIPAL

ROCK- FORMING MINERALS,
Ti'anslated and Modified fi^vm HussaR s
Tabellen zur Bestimmung der Mineralien.
By C. L. Herrick.

Table of Abbreviations.

c = vertical crystallographic axis.

a = brachydiagonal in orthorhombic and triclinic systems.

R clinodiagonal in monoclinic system,
a, b. C, == axes of elasticity.

w = exponent of refraction in ordinary ray. } In uniaxial

f =

‘ in extraordinary ray. (|

crystals.

“ “ “ in intermediate axis, "j

p =

“ '' in red light. 1

- In biaxial crystals,

V =

in violet light, J

1

Disp. =

dispersion of axial points.

Symbols of planes essentially as in Dana’s Text-book of Mineralogy.

A. Minerals opaque

N^aine.

die in Comp . and
reactions.

Specif.

Gray.

Crys-

tal

Cleav-

age.

Usual combina-
tions and form of
Sections.

Tioins.

I. Mag-
netite.

Fe.. 0^ =
Fe’0-F[Fe,J 0,.
soluble in FI Cl.

4.9-

5-

I

In the
plane

I.

Granular and
I. Quadratic and
Triangular.

In the
plane i.

i

i

2. Titan-
ic Magne ■
tite.

leu pj

Only distinguish-
able by chem.
analysis.

4.8-

5-1

I

I and granu’ar.

as above

3. Pyrite.

Fe S2

Soluble in nitric
acid separating
sulphur.

4.9-

5-2-

I

H

[i-2j

Regular hexa-
gons and penta-
gons.

Interpene-

trating

twins

[i-2.]

4. Titan-
ic Iron.

Fe Ti 0.. +
-KFe2

Soluble in H Cl
with dif. With
salt of phosph.
gives reaction for
Ti.

4. qb-
5-21

Hex.

R and
OR.

con-

choi-

dal

frac-

ture.

Tabular R.oR
also R, - 2 R

and granular
grains elongate
rather than
rounded.

Sections chiefly
hexag. elongate.
In zic-zack ed or
reticulated forms.

iAxes par-
allel, Poly-
synthetic
twins in

R.

1

5 . Graph
ite

(and Bitu-
men.)

C.

Bitumenous
black rocks, be-
coming gray on
heating.

1.9-

2-3

Flex.

0

Very rare, in
thin hexagonal
plates and irreg-
ular scales.

6. Pyrr-
hotitc.

See also
Cliro-'] b
mite, e

Pleo- I y
nast, 0

Spec • 1 n
ular 1 d
Iron. J

Fe S ,
n n T I

4-54

4.64

Hex.

•

Irregularly gran-
ular.

even in thinest sections.

TABLE 1.

Color and
. histi'c.

Structure.

Association.

Alterations.

Occuri'ence, etc. !

Iron black,
b 1 u e-b lack
metallic lustre

Often in
beautiful cru-
ciate aggre-
gates, or, as
result of alte
ration, about
a mineral or
in its cleavage
lines.

With nearly
all rock -form-
ing minerals,
parti cularly
a u g i t e , oli-
vine, plagio-
close, nephe-
lin. and leu-
cite.

Very often
into limonite,
forming a red-
ish brown
band about
the crystal of
magnetite.

1. As primary ne-
cessary component of
basic eruptive rocks
and accessory in near-
ly all crystallines.

2. As result of al-
teration of olivine,
augite, hornblende
and biotite.

-

Into titanite
a n cl limonite
(Forms the
transition t o
titanic iron.)

Pi imary, in basalts
and crystalline slates.

In reflected
light yellow,
metallic lustre

Into limon-
nite.

Rarely as accessory
secondary component
of altered basic erup-
tives and (also pri-
mary) in crystalline
slates. •

1

Blackish
brown, metal-
lic lustre. If
altered, gray
in reflected

light.

With plagi-
oclase, augite,
horn blende,
and olivine.

Into titanite
and rutile with
specular iron.

In basic eruptives,
(particularly granu-
lar diabases, gabbros,
basalt, pikrit) ; also
in crystalline slates.
[Distinguished from
magnetite by form of
sections and altera-
tions.]

Iron black
with metallic
lustre.

Rarely in cryst.
slates, clay- and clay-
mica-slates, gneiss,
limestone; and as in-
clusions in staurolite,
andalusite, chiasto-
lite, dipyre, etc.

Bronze yel
low. Metallic
lustre.

i

i

Very rare in cryst-
alline slates and con-
tact slates

Ea.sily distinguished
from pyrite in re-
flected light by the
lustre.

'

*

B. Minerals transpa-

1. Minerals crystallizing in the Isomet7'ic System.

Name.

Chemical comp and
reactions.

Specific

Gravity.

Cleav-

age.

Unsual combi-
nations Cfform
of sections.

Trains .

Color and
amount of
7'e fraction.

I. Hauyn
Group.
a. Socialite

3 (Na, [Al,] Si,
Og)-f 2 Na Cl. Cl
reaction. Easily

soluble in H Cl.
leaving a gelatin-
ous residue of Li
0.,. On evapora-
tion, cubes of salt.

2.13-2.2C;

i

Granular and
i (rarely i. H)
sections cpiad-
ratic and hex-
agonal. !

Inter-
pen’tra
ting
twins
in a tri-
gonal-
secon-
dary
axis.

i

Colorless,
red from
presence 01
Fe-i O3,
greenish or
bluish, blue.

1

b. Hauyn

i ,

and

i

ic. Nosean. ;

1

1

i

2, (Na, Ca) (Al,)
Si, Og-t-(Na,, Ca'i
SO^. Reacts for Ca
and H, SO^.

3 Na, (Al',) Si,
Og-f-Na, SO^.

Reacts for H, SO^
Koth are soluble
in HCl with sepa-
ration of gCiatinous
Li 0,

2.4-2. 5

1.279-

2.390.

i

1

j

Crystals i and
I as the above

'Crystals usu-
ally corroded.

1

Twins

ini&as

above

1

Colorless,
blue, black.

Colorless,
brown black

1

[2. Garnel
! Group.
a Alma
nacline.

1

Fe,^ (AI2 ) Si^ O12.

1

1

1

i

3.78
^3 1-4

Imper.

in

i

j

i

i, 2-2 and
granular. Sec-
tions quadrat-
ic, hexagonal
or octagonal.

Red, in very
thin secti’ns
nearly color-
1.772.

b. Pyrope.

'(Ca 0, Mg 0, Fe
c) Mn O) Al, O3
3Si 0-2 containing
chromium.

3-7-3-S

1 Imper

I i

' Granular.

1 Blood red.

TABLE II.

rent in thin Sections.

{Sec also amorphous-minerals^ Opal and Hyalinamorph)

Strticture.

Association.

Inclusions.

Alteraiio7is .

Occurre7tce.

Remarks.

Intimately
united
with feld
spar and
hornblend
often with
a colorless
nucleus
and red
cortical
part closed
by oxides
of iron.

With micro-
din e augite,
and mica in
syenites, with
sanidin and
augite in
Trachytes.

Fluid inclu-
sions, gas
pores.

Glassy inclu-
sions, needles
of augite.

Becomes tur-
bid from al-
teration into
zeolites.

As primary
constituent in
syenites and
rarely in au
gite-trachytes
as secondary
product in
cavities of the
latter.

These three
minerals can
only be dis-
tinguished
with certainty
by microche-
mical qualita-
tive analysis.
Hauyn may
be distin-
guished from
sodalite by
the presence
of the charac-
teristic need
les of gypsum
on evapora-
tion of the ni-
tric acid solu-
tion. Sodal-
ite is charac-
ized by its
chlorine.
Hauyn and
Nosean are
chemically
difficult to dis-
tinguish and
mineralogical-
ly may be
united.

Garnet may
be easily dis-
tinguished
from Hauyn
by the color
and insolu-
bility in acids

Very often
with a cor-
tical part
colorecl dif
ferently
from the
centre
which may
be darker.

opaque.
Often col-
ored by
iron in the
fissures

Chiefly with
leucite, nephe
line and au-
gite.

1

Innumerable
gas pores and
glass inclu-
sions ar-
ranged in
bands, minute
black grains
and needles,
often regulai-
ly distributed,
tables of spec-
ular iron.

Alters into an
aggregate of
double re-
fracting need-
les and fibres
of zeolite and
cal cite produ-
cing a destruc-
tion of the col-
or, and by sec
ondary colora-
tion by iron,
a change to
yellow.

As primary
constituent of
later eruptive
rocks (those
containing
sanidin as
well as -those
bearing plagi-
oclase) such as
trachyte(rare-
ly) phonolite,
leucitophyre,
tephrite and
nephelin and
leucite-basalts
Occurs also
frequently in
volcanic tra-
chyte.

Primary con-
stituent in
many slaty
rocks, fre-
quently in
granite, rarely
in trachitic
rocks

Primary con-
stituent of ser-
pentines.

Often uni-
ted with
quartz or
feldspar
in micro-
pegmatite.

i

Usually with|
quartz, ortho-
clase, biotite,
and horn-
blende.

Cavities hav-
ing the form
of the garnet
crystal (nega-
tive crystals)
Fluid inclu-
sions, quartz
grains, rutile
grains ; often
in zonary
jbands.

Changes on
the surface
and in crevi-
ces to plates
of chlorite, or
(more rarely)
into fibrous
hornblende or
augite.

with olivine
and augite.

1

1 Very poor,

1

j

Very charac-
teristic are
zones of au-
gite fibres ar-
ranged in
groups per-
pendicular to
the surface.

!

Na?iie.

Chemical Comp,
and reactions.

Specif.

Grav.

Cleaz'

age.

Usual combi-
natiotis and
form of Seds.

Twins.

Color and
and amt.
of refract

Structure.

c. Mel
anite

Ca3 (Fe.jSigOj,

•

1

^ J

3-0-4-3

Incom-.

plete.

i

Crystals

Black, in
sections
dark
brown,
quite
opaque.

Often with
beautiful
zonary struc-
ture, then
often double
refracting.

3. Spinel
Group.

' a. Chro
mite.

b. Pico-
tite.

c. Pleo-
nast.

d. Her-
cynite.

Fe 0 Cr2 O3

MgOrAl.,031
Fe 0101403/

FeO [A1.^ O3/
MgO\Fe, O3I

Fe 0. AI2 0..

Insoluble in
acids and unaf-!
fected by H FI. j

4.4-4. 6

4S

Over

3.6s

(3.8-4. 1)

Incom-

plete.

I .

Granular
and I.

I.

Very minute
grains.

I.

Twins
in I.

Reddish
brown,
metalic
lustre
Becomes
transpar-
ent with
difficulty

Isolated
grains often
found in
basalts with
a broad sub-
opaque
bqrcler.

Dark

green

Frequ'nt
with
quartz,
ortho
clase,
and mica

Often
double re
fractive and
with a dis-
tinct zonary
structure
gf nerally
cloudy, com-
bined with
plagioclase

4. Anal-
cite.

Na2(Al2) 1

Soluble in H
Cl vdth sep of
Si 0-2 jelly.

i

2. 1-2.28

Incom-

plete.

(Ac-

cord-

ing

to

Tsch-

ermak

H.)

Chiefly
compact
granular,
in cavities

Colorless

white,

np=

1.4874

[

Penetrating
feldspar.and
irregularly
distributed
in the
magma.

5. Fluor-
ite.

Ca FI 2 .
Decomposed by
concentrated
H2 SO^ with
liberation of
H FL

3.1-32

( lom-
plete

I.

1

Occurs in
rocks only in
the form of
Iminute an-
gular grains.

Blue,

colorless.

! very
strongly
refrac-
tive.

Characteris-
tic is the
rough sur-
face of a sec-
tion . Group-
ed as inclu-
•sions in mel-
iliie or oli-
vine. Often
exhibiting
double re-
fraction.
Colors of
polarization
not bright.

6. Pe-

rowskite.

Ca Ti 0.3 .
Decomposed in
H2 SO^ but not
M Cl.

4.0-4. 1

H.

! In irregu-
lar branch-
ing and an-
gular forms,
generally in
distinct oc-
tahedrons.

Very

rare.

In ter-
pen e-
tra ting
twins.

Violet
gray,’’
reddish
gi-ay
brown.
In strong
relief.

i

i

i

Mineral appearing regular

TABLE III.

Association.

Inclusions.

Alterations.

Occurrence.

Remarks.

With augite
saiiidine,
nephelinCj
hauyn, and
leucite.

Very poor,
augite and
apatite needles,
glass inclusions.

Primary component
of phonolite, leuci-
tophyr, and volcanic
products.

Compare Chromite.

With olivine
and augite.

Most rarely
with olivine
and augite.

Primary accessory
component. In oli-
vine rocks, serpen-
tine and basalts.

Picotite often as in-
clusions in olivine.

As above but rarely,
more often in granu-
lites and in metamor-
phic (contact) rocks.

Very similar to
melanite; when in
grains only chemi-
cally distinguish-
able.

Melanite is, how-
ever, almost al-
ways crystallized,
and so easily dis-
tinguishable,
a and b can only be
distinguished
chemically.

The spinels maybe
distinguished irom
magnetite by
transparency (in
very thin sections.)
and by the insolu-
ability, 3 c and 3 d
can only be distin-
guished chem-
cally.

With plagio-
clase augite or
hornblende.

Poor in inclu-
sions. Fluid
inclusions,
needles of
apatite.

Rare in later basic
eruptives (either pri-
mary or as product of
alteration of nephe-
line). In cavities in
phonolites, trachyte
andesites, basalt, as
alteration product.

With quartz,
orthoclase and
biotite.

Fluid

inclusions.

Very rare ; second-
ary in quartz
porphyry.

With nephi-
line, melilite,
augite and
olivine.

Very poor.

In nepheline-
leucite— and mele-
lite-basalts.

Distinguished
easily from spinel
by color and opti-
cal anomalies, and
from garnet by its
crystalline form.

--= Leucite. See below.

II. Double-refractive minerals.

A. U^iiaxial optically.

I. Tetragonal system, a. Double refraction positive.

Name.

Chemical
comp, and
reactions.

Specific

graviiy.

Cleavage.

Usual combi-
Jiations and
form o f sec's.

Twins.

Character cena
amount ofdou
ble refraction.

Polariza-
tion col ■
ors.

I . Leucitc

K, (Al,)
Si, 0,.,.

2 45-2-5

Incom-
plete pris
matic i-i
and 0.

Grains and
(generally)
crystals i.
4-2. Sec

tions octa-
gons fre
quently with
rounded an
gles, more
rarely hex-
agons.

2-i, polysyn-
thetic twin
striations in
these planes,
crossing at
right or
oblique an -
gles.

Small individ-
uals without
twin-striations
appear 'isotro-
pous. In con
verg. pol.
light no evi-
dent axis fig-
ure. Double
refraction fee-
ble, positive.

Not bril-
liant, blu-
ish gray.

2. Rutile
(Nigrine
Sage-
nite.)

Ti 0^.
7"z-reac-
tion with
phosphor-
ous bead.
Insoluble
in acids.

4- 2-4-3

(4-277)

1

I

and

i-i

i

I. i-i,

I

granular;
generally,
however, in
'minute elon-
gate needles
and crystals.
The prisms
are striate
j parallel to
'axis c.

1

i

Very frec|uent
and character-
istic in the
plane i-i;
‘knee shaped’
with an angle
ot ii_4°-2 5";
also tissue of
fine needles
which cut
each other at

1 an angle of
about 60°
(sagenite)., also
cordate twins
in 3-i, fre-
quent.

Crystals usu-
ally too small
for determi-
nation with
condenser.
Double re-
fraction
strong, posi-
tive.

None par-
ticularly
brilliant.

3. Zircon

Si 0,

H2 SO,
decompo-
ses; other
acids with-
out effect.

1

i

1

1

4-4-4- 7

i

i

j Incom-
plete I

1 and I.

j

i

I, i-i,

3-3 ;

numerous
combina-
i tions; al-
imost solely
i in minute
ibut sharply
■ defined crys-
‘tals.

!

i

Very rare

I-i.

Positive,
very strong.

Very bril-
liant,
emerald-
green, hya-
cinth-red
and irrid-
escent.

II. Double-refractive minerals.

A. Uniaxial optically.

I. Tetragonal system, a. Double refraction positive.

TABLE IV.

Color and
amount of
refraction.

Pleochro-

ism.

Structure.

Association

/nclusions.

Alterations

Occurrence.

Remarks.

Colorless,

0=1.508

f:=i.50cj

Aggregate of
spherical crys-
tals to form a
large crystal.
Zonal and ra-
diating ar-
rangement of
the inclusions.
Large corro-
ded crystals of
the first order,
and minute
sharply de-
fined crystals
of second or-
der, the latter
often pene-
trating augite

With aug-
ite.olivine.

plagio-
clase. and
sanidine.

Inclusions
zonary or ra
diating, or
collected in
a central ag-
gregate.con-
sisting of
minute
glassy parti-
cles, gas
pores, augite
needles, etc
as well as of
Hauyn, au-
gite, apatite
and mela-
ite.

Into an
aggregate
of color-
less or yel-
lowish,
finely radi-
ating fi-
bres or
grains of
zeolites,
rarely
pseudo -
morphs of
analcite af-
ter leucite.

Primary, es-
sential const!
tu'nt with san-
idine etc. in
leucitophyres,
leucite-teph-
rites, and ba-
salts, also with
nepheline and
plagiolase.
Only found in
later basic
eruptives.

The foregoing
characters
make it easily
recognizable
unless It oc-
curs in very j
minute grains
in the magma,
when it may
be difficult to
distinguish it
from inter- |
spersed color-
less areas of
the glassy ba-
sis. In this
case to be rec’j
ognized microj
chemically. |

Hon’y yel-
low to red-
dish
brown,
grains oft-
en opacjue
or merely
transluc’nt
( Nigrine) ,
in which
case with
(incom-
plete) me-
tallic lus-
tre.

Not par-
ticularly
noticeable

i

: 1

In biotite fre-
quently very
regular com-
pounded into
“sagenite”
forms, also
united to ti-
tanic iron.
Often as an
inclusion in
the accom-
panying min-
erals, particu-
larly garnet
and ompha-
cite.

With

quartz, pot
ash feld-
spar, gar-
net, horn-
blende,
omphacite

Very poor.

i

As primary ac-
cessory com-
ponent abun-
dant in near-
ly all crystal-
line slates, par-,
ticularly those
bearing horn-
blende and
augite, as am-
phibolites and
eklogit’s. Also
as secondary
dec'mposition
product of ti-
tanic iron,
frequent in
clay slates.

Easily distin-j
guished from;
zircon by the|
polarization !
colors, color j
and tendency!
to twin. j

i

j

Colorless,
wine yel-
low. Re-
fraction
strong,
hence
dark con-
toured (by
total reflec
tion).

1 .92
£=1.97

j Not no-
i ticeable.

1

Like rutile,
one of the first
formed com-
ponents of
rocks and
therefore fre-
quent as in-
clusions in the
others.

With

quartz, or-
thoclase,
biotile,
horn-
blende,
augite.

Fluid inclu-
sions, nee-
dle-shaped
cavities, and
long uniden-
tified nee-
dles.

-

Primary ac-
cesory compo-
nent of gran-
ite, syenite,
quartz -por-
phyry, trach-
ytes and many
other eruptive
rocks.but rare.
More frequ’nt
in crystalline
slates with
rutile.

Well charac-
terized by the
crystalline
form, polar-
ization colors,!

and strong j
double refrac-j
tion. ;

1

i

1

I

b. Double refraction

A'ame.

CJiem. Comp, and
reactions.

Specif.

Grav.

Cleav-

age.

Usual combi-
nafs and forin
of the Sections.

Tzvins.

Char, and
amp of the
dpi. refract

Polar-

ization

Colors.

Color and
Amount of
refraction.

4. Ana-
tase.

i

1

As in rutile.

3-83-

3-93

0 and

I .

Apex I.

As in
rutile.

Like

rutile.

Dark,

lavender

blue.

5. Ale-
Jonite

g'P-

a Mejo-
nite.

b. Sea-
polite.

Ca,; (Al„) Si;,

R3 (Ag Si,; 0,1
(R=Ca.Mg No,)
Soluble in H Cl
separating pulver-
ent Si 0.,

2-734-

2-737-

2.63-

2-79

Com-

plete.

i-i

Crystals I. i-i.
I and large
grains or long
columnar in-
dividuals.

1 _

Double .
refraction
negative,
rather
strong.

1.594-
I 597
1.558-
1.561
Colorless,
white.
w^i.566
£==1-545

i

c. Cou-

sera-

nite

and

Dipyre

Similar to scapo-
lite; rich in alka-
lies, H., 0 .
Unaffected or but
little affected by
acids.

2.69-2.76

(2.bi3)

2. 62-2. 68

i-i.

frac-
ture in

0.

Long columns^
I. i-i.
rounded or
frayed out at
the end.

1

1

1

i

As in
scapolite,
rather
strong.

Rather

bril-

liant.

Bluish, in
sections,
colorless,
pelucid;
becomes
black from
inclusions
6^=1.558
£=i-,543

d. Me-
[ lilite.

(Ca, Mg. Na,) „
(AI2 Fe2 )2

Si;, 0;j„

easily soluble in
H Cl with sepa-
ration of gelati-
nous silica.

2.90-2.95

I

j

Paral-
: lei
iO and

1 I-

■

i

Almost always
in crystals;
thin plates
predominat-
ingly 0 . I .
i -i

Irregular
grains. Sec-
tions mostly
linear, rect-
angular or
rarely
rounded.

Rarely

inter-

pene-

trating

twins

with

the

princi-

pal

axes at
right
angles.

Feeble.

Not
very
bril-
liant, if
jyellov\-
and fi-
brous it
affords
the col-
oration
of an
aggre-
ate, if
color-
less the
polari-
zation
colors
are
bluish
gray.

Usually
citron yel-
low, honey
yellow
colorless,
to yellow-
ish white.

negative. table v.

Pleo-

chro-

ism.

St r tut lire.

Associ-

ation.

Tuclusions

Alterafns

Occurrence.

Reniarks.

Like

rutile.

With

quartz,

ortho-

clase,

biotite.

Very rare in
granite, quartz
-porphyry,
and crystal-
line slates.

Scapolite
seems to fre-
quently re-
place plagio-
claseand to be
formed by its
decompositi’n

With
sanidine
sodalite,
and
augite.
With
quartz,
plagio-
clase.
calcite.
augite.
garnet,
rutile, &
titanite.

Poor.
Fluid in-
clusions.

Rutile
occurs in
scapolite.

Confused

fibrous;

changed

into

calcite.

Primary ac-
cessory com-
ponent, rarely
in trachytic
rocks.

Rare, in crys-
talline slaties,
with plagio-
clase as a
(secondary?)

accessory

component.

S capolite is easily
distinguished from
orthoclase and cal-
cite by its optical
peculiarities and

cleavage.

Mejonite is recog-
nized by its crystal
form.

Rect-

angu-

lar

longi-
tudinal
sect’ns
show a
very
feeble
dichro.
ism.

Crystals in
limestone,
often very rich
in inclusions

With
calcite,
actinolite
and mica.

Very
rich, pai-
ticles of
carbon,
quartz
grains, «&
plates of
musco-
vite, ir-
regularly
distribf’d

Fibrous
decompo-
sition
with for-
mation of
calcite in
the

crevices.

As contact
mineral in
metamorphic
limestone,
very rare.

Easily distingui.shed
from andalusite, op-
tically, and from
chiastolite by its
structure.

Rectangular
longitudinal
sections show
striations and
hbrous struc-
ture parallel to
the shorter
side (i. e. axis
c); these are
very fine spin-
dle-shaped
cavities which
appear as min-
ute circles
when cut at
right angles to
the axis c, (so-
called ‘‘spile
structure”)
Coalesced
with leucite
or pentrating
it.

With

1 nephe-
line,
leucite,

! augite
and

olivine.

1

i

The
fibrous
structure
is due to
change
into
zeolitic
substan-
ces.

As primary
ingredient of
the nepheline
-and leucite-
basalts re-
placing neph-
eline, often
very abun-
dant.

Easily recognized
by the crystal lorm
and fibrous structure.
Easily confused with
nepheline if color-
less, but does not
show hexagonal iso-
tropous sections. Of-
ten only disting-
uished from serpen-
tine by the light yel-
low color and the
absence of remains
of olivine. Erom bi-
otite distinguished
by the lighter color
and absence of
strongly dichroic
longitudinal sections.

Poor.

!

2. Minet'als crystallizing iti

a. Double refrac-

Na??ie.

Chemical
comp . and
reactions.

Specific

Gravity.

Cleavage.

IJnsual combi-
nations Cfform
of sections.

Tuvins.

Char, and
amount of
did. refract

I . Quartz.

Si 0.,.
Insoluble
except in
H FI.

!

i

2.65. 1

!

1

i

Incom-
plete in R.
Sections
full of
cracks due
to coil’

; choidal
dracture.

Oranular or
crystals R.— R
or iR. R.-.R.

Usually in
larger indi.
viduals. Sec-
tions are reg-
ular hexagons
iwith two par-
1 allel sides

With parallel
axes. Rarely
twinned when
forming a
component of
rocks.

i

!

Feeble.

i

1

i

j longer than
ithe others, or
■ in rhombs,
never as mi
croliths.

I . Tridy
mite.

As above.

2.282

2.326.

jlnc’mpl’te

iil O.

In very mi'
nute thin
plates O and

I.

Frequent.
Twinning
plane a sur>
face of ^ and

Ve.iv fee-
ble. '

On account of the minute size of the
crystals found in rocks accurate deter
mination is usually impossible. Micro
jscopic tridymite behaves in parallel
[polarized light as though hexagonal.

TABLE VL

the Hexagonal System.

tion positive.

1

[

Occtirrence.

Remarks.

Structure.

Often

ored

col

by

iFe^ O3 in
crevices,
or render-
ed con-
fused by
inclusions.
Quartz in
eruptives
often cor
roded. Co-
alesces
with or-
thoclase to
form mi-
cropegma-
tite fre-
quently in-
granites.
In porphy-|
ritic erup
tives also
sphaero-
litic.

Association.

With ortho

clase (and san
idine) more
rarely with
plagioclase,
biotite, horn-
blende, and
augite. Never
occurs in au
gitic oliv-
ine-bearing
rocks or in ne-
pheline-or
leucite bear
ing rocks as a
primary con-
stituent. With
muscovite and
biotite.

Usually in
aggre-
gates of
minute
thin hex
agonal or
irregular
superim-
posed
plates.
Often in
the vicini-
ty of the
feldspar or
in large
masses in
the mag-
ma.

With quartz,
sanidine, pla-
gioclase, au-
gite, biotite,
and horn-
blende. Sec-
ondary with
opal and chal-
cedony.

Inclusions. ' Alterations.

Poor in min
eral inclusions
Apatite- col-
umns. In
the fragment
al states and
granites rich
in fluid inclu-
sions and long
brownish or
blackish curv-
ed needles.
In eruptives
rich in glass
inclusions and
gas pores.

There are
none^although
changes due
to molten
magma are
not rare in
quartz from
eruptive rocks
See corrosion
and seconda-
ry glass inclu-
sions.

Fluid inclu
sions.

constituent.

(a) In erupt
ive rocks as
component of
the first order,
as macroscop-

lar, often de
ceptively like
sanidine, but
easily distin-
guished from
isotropic sec-

ic fragments j tions of it.
in grains and|Distinguished

crystals in
granite with
fluid cavities
and in quartz
-porphyry

from nephe-
line and apa-
tite by insolu-
bility ; from
corundum by

Occurrence.

Primary com
ponent and
secondary in
rhyolites, tra-
chytes, horn-
blende-and
augite-ander-
ites. In gen-
eral, moie fre
quent in later,
acid erupt-
ives and more
rare in older
basic erupt-
ives. Second-
ary in cavi-
ties of these
rocks and, in
that case, usu-
ally in large
plates.

and trachytes character of
with glassy jdouble refrac-
inclusion, anddion, from cal-
also as acces-jcite by cleav-
sory in manyjage and twin-
other erupt- ming.
ives. As con-'
stituent of the!
second order!
in the magma
of these rocks !

(bj In nearly!

all^ crystallinei Microscopic
itridymite may

slates.

II. Secondary
product by
alteration of
silicates ; in
diabase in
granular ag-
gregates, and
in veins of
many rocks.

III. In water
worn grains
in many clas-
tic rocks.

IV. Forming
a simple rock,

as quartzite
etc.

be recognized
by the form of
its aggergates,
while for the
larger masses
the optical
characters
serve to iden-
tifv it.

b. Double refraction

Name.

Chemical
Comp, and
reactions

Specif.

Gravity.

Cleav-

age.

Usual Combina-
tions and form of
the Sections.

Char, and
Amt. of dbl.
refraction.

Colors of
Polarization

Color and
Amount of
refraction.

I . Cal -

cite.

Ca CO3 .
soluble with
effervescence
with H Cl. In
acetic acid
soluble.

2. 6-2. 8
(2.72)

Incom-

plete.

R.

Only in irregu-
lar grains and
crystal aggre-
gates.

Polysynthetic
twin marking

in- >4 R .

i

Very con
siderable,
negative.

Generally
not intense,
gray, but
brilliantly
irridescent
like tale
epecially
when in
small grains.

Colorless,
white to
gray.

1-6543

£= I ••4833
( Absorb-
tion
feeble.)

2. Dolo-
mite .

(Ca Mg) CO,
I^ess easily
soluble.

2.85-

2.95

As

above.

Grains and R.

As above.

As above.

3. Mag-
nesite.

Mg CO3 .
still less
soluble.

2.9-3. 1

As

above.

As above.

As above.

As above.

4. Side-
rite.

Fe CO, easily
soluble with
effervescence.

3- 7-3- 9

As

above.

As above.

As above.

Yellowish

brown.

5. Nepli
elincG' p.
a. Elae-
olite.

fNa K)2 (Al,)
Si2 Og Soluble
easily in 11 Cl

2.65

(2.591)

Incom

plete

large

fissures

Only in large
grains.

Double

Chiefly
bluish green
not brilliant.

Green,
reddish
brown,
oily lustre
in sections
colorless.

b. Neph-
eline.

with separa-
tion of gela-
tinous silica,
on evaporat'n
cubes of salt.

(2.58-

2.65)

Incom-
plete.
0 andl

Hexagonal and
rectagonal ! In
minute crystals
I . 0 short CO
lumnar and
minute irregu-
lar grains.

refraction

feeble.

Similar to
fieldspar
strips in very
thin sections

Colorless,
trans-
parent
0=1.539-
1.542
e= 1.534

I- 537-

c. Can-
crinite.

Soluble with
effervescence
separating
gelatinous
silica.

2.448

-2.454

Incom-

plete

I

Large irregular
grains.

Rather

'brilliant.

Aggregate

polarization

Citron
yellow, al-
most
colorless
insections.

d. Lieb-
enerite.

Incompletely
dissolved by
H Cl.

2.799

-2.814

Very
Incom-
plete I.

Very dis-
tinct aggre
gate polar-
zation.

Oil green,
in sections
colorle.ss,
white.

Nepheline differs from apatite in its incomplete cleavage, microchemical reactions and
crystal form, since apatite often exhibits, besides I and O, the plane i, and occurs in long
columns Quartz never occurs in so minute crystals. Feldspar bands are long and twinned.
Melilite has no hexagonal sections.

negative. table vii.

Structure.

Association.

Inclusions.

Alterations.

Occurrence. .

Remarks.

Usually in
granular ag-
gregates in
cavities, in
bands or veins.
Also in irreg-
ular grains &
simple indi
viduals be-
tween the
constituents.

In nearly all
rocks which
bear augite,
hornblende,
biotite and
plagioclase.

Fluid in-
clusions,
very poor
in mineral
inclusions.

None.

Primary and sole
component of
limestone, etc.
Not known cer-
tainly from erup
tives except as
secondary pro-
duct, particularly
of bisilicates and
mica. In crystal-
line slates as both
primary and
secondary.

Well character-
ized by rhombo-
hedral cleavage
and twin-lamel-
lation. When in
small grains not
easily determined
Reliance must be
pu t upon the sol-
ubility and colors
of polarization.

As above.

Without the
polysynthetic
lamellation.

As above.

With

serpentine.

With olivine and
serpentine as pro-
duct of alteration.

Magnesite ^ and
siderite only
chemically dis-
tinguishable from
calcite.

As above.

As calcite.

In concentric
shells and radiat
ing spheres in an-
decite. etc., as
product of alter’n

Irregular
grains coales-
ced with the
other constit-
uents.

With so-
dalite micro-
cline, horn-
blende, and
titanite.

Poor, fre-
quently
colored
green by
particles
of horn-
blende.

Fibrous transition
into zeolites.

Easily recognized
macroscopically.
solubility and Na
reaction forming
good characteris-
tics.

Primary essential
component of
older eruptives, in
elaeolite-syenites.

In crystals or
aggregates of
minute irregu-
lar grains.

Withleucite.
augite, or
with sani-
dine and au-
gite, or with
hornblende
and titanite.

Frequent-
ly augite-
microlites
arranged
parallel to
the sur-
faces.

Usually unaltered
in phonolites or
polarizing like an
aggregate and
cloudy, showing
passage to zeolites

Primary compo
nent of later
eruptives, nephe-
linites, nepheline
-and leucite-ba-
salts, phonolites
and teph rites.

See below.

P

Fibrous, coa-
lesced with
nepheline and
orthoclase.

As in
eiaeolite.

Poor, iron
oxide
flakes, as
in eiaeo-
lite.

Fibrous decompo-
sition forming cal-
cite. (Cancrinite
seems to be but
an alteration af-
ter nepheline.)

As eiaeolite,
rare.

Distinguished
from eiaeolite
only macroscop-
ically by amt. of
Ca CO3

Only as fiag-
ments in
macroscopic
crystals.

With flesh
colored orth-
oclase and
mica.

Apparently only a
total alteration of
nephelin(?)'or cor-
dierite(?), largely
consists of minute
muscovite scales.

Rare in orthoclase
porphyry.

Easily recognized
by crystal form |
and alteration.

Zeolites usually show their secondary character. Tridymite has no such short rectangu-
lar longitudinal sections. When nepheline appears as an aggregate of minute grains it can
be distinguished from colorless glass-masses or quartz or othoclase aggregates by micro-
chemical methods.

Name.

Chemical
comp, ana
reactions.

Specific

gravity.

Cleavage.

Usual combi-
nations and
form of see's.

Twins

Char. (End
amount of
d'bl refract

Polariza
tion
colors .

6. Apatite

^3 ^12

Cl Ca^ P3
0,, FI.
Dissolves
in acids,
gives phos-
phoric
acid reac-
tion.

3 16-3.22

Crystals,,
more rare
ly granu-
lar. Paral-
lel 0 and
I, incom-
plete.
Fracture

II 0 very
perfect,
hence the
needles
are found
broken in-
to sections

I, I and more
rarely 0, gen-
erally long
columns.

Not strong

Usually
not bril-
liant, as in
nepheline.

\

i i

(Al,) O3
Insoluble.

3-9-4

R and oR.

!

i-2.oR. Rand
grains. Hex
agons and
rectangles
which are
truncated at
the angles by
R.

Rare

in

rocks.

Strong.

Very bril
liant.

i

1

I

8. Toiir-
maline.

Complica-
ted. Boric
acid reac
tion Not
attacked
by acids.

3-059

1

Incom-
plete R
and i-2. i
■Very com-
plete frac-
ture 1 oR.

1

Almost alw’ys
crystalline R

i-2.X (i-R-) -

transverse sec
tions triangles,
hexagons non-
agons. Often
hemimorphic
parallel to
main axis, oR
below, R
above.

Strong.

Rather
brilliant
between
red and
brown.

9. Specular
Irott

Fe, O3
Easily sol
able in
HCl.

5-19-

5.28.

1

1

i

R.oR.
Not char-
l^acteristic
in micro-
scopic in-
dividuals.

1

Tabular plates
oR. i-2 and
irregular
plates.

1

i

i

1

With

axes
paral-
lel!. In-
terpen 1
etra-
tion
twins
with

re en-
tering
angles.

Not defin-
able on
account of

occur-

rence.

Very fee-
ble.

Minerals seeming to crystallize in the Hexagonal System.

2 I SeeM onoclinic System-

TABLE VIII.

Color and
amount of
refraction.

Colorless,
white, red
dish, green
black
through
numerous
inclusions
not trans
parent , as
nepheline
n— 1*657

Colorless,
sky blue,
spotted, al-
so brown
through in
elusions.
Stands out
well in sec-
tions be-
ing strong-
ly refract-
ive.

*1=1.768

£=1.760

Chiefly
bluish
gray,
brown.
w= 1 . 64
£=1.62

Pleochro-

ism.

If colored,
with evi-
dent di-
chroism.

When col-
ored, very
strong
(<i=sky
blue
£=.sea
green.

Structure.

In irregular
grains or long
often slender
columns, fre-
quently , bro
ken into joints
by basal frac
ture. Inclu
sions. Only as
accessory com
ponent. As in
elusions par
ticularly fre
quent in bisil
icates, horn
blende and
biotite.

Surface of sec
tions rough.

In round
grains or short
columns. Zo
nary struct’re,
blue nucleus
and colorless
cortical layer.

Association

Known to oc-
cur in nearly
all rocks.

Inclusions.

Iron black
with me
tallic lus
tre. In
thin plates
blood red,
also yel-
lowish red
and brown
violet.

Very
strong di
chroism.

w=dark

blue,

brown to
black. ^
£=light
blue to
brown.

Macroscopic
and very 77ii
nute crystals,
rarely in
grains, as in
certain meta
morphic rocks
In granites co-
alesced with
quartz in
grains Large
individuals of-
ten frayed out
in a radiating
manner at the
end.

Only in
plates in crev-
ices of miner
als by infiltra-
tion. Second-
ary except per
haps in ba-
salts.

With quartz,
orthoclase and
biotite, Pleon-
ast, and anda^
lusite.

Glass inclu-
sions, gas
pores Very
characteris
tic are black
or brown
needles, or
minute
grains filling
the entire
crystal, giv
ing the cross
section par-
ticularly a
remblance
to hauyns.
Central in
elusion of
glass etc. of-
ten assum-
ing the
shape of the
crystal.

With ortho-
clase and mus-
covite in gran-
ite. With
quartz, ortho-
clase, mica
and other ac-
cessory miner-
als, such as
staurolite and
garnet.

Very poor,
fluid and
glass inclu-
sions; zir-
I con; dusty
brown inclu-
. sions (in
j “common
corun-
dum.”)

In nearly all
rocks particu-
larly with de-
composed bio-
tite, horn-
blende, au-
gite, magne-
tite, of which
it is a product
of decomposi-
tion.

A Iter a-
tions.

Al-

ways

un-

chang

ed.

Occm'rence.

Accessory in
I nearly all
jrocks. One of
'the first min
lerals to sepa-
rate from the
’magma.

Very rare.
Contact min’
jeral in meta-
morphic slates
and trachytic
ejections.

Very poor.
Fluid inclu-
sions.

Into
pulver-
ent li-
monite

Remarks.

Distinguish-
able from
hauyn in the
longitudinal
section and
basal fracture;
from olivine
by optical pe-
culiarities and
fracture.

If granular;
similar to ap
atite yet rec-
ognized by
colors of po-
larization.

Primary com
ponent, fre-
quent. Gran
ular, accessory
in many crys-
talline slates
and in clastic
rocks. Char,
acteristic in
contact with
eruptive rocks

(See under as-
sociation )

Easily recog-
nized by crys-
tal form and
plcochroism.
Distinguished
from horn-
blende by op-
tical charac-
ters.

Easily recog-
nized.

II. Biaxial minerals.

I. Rhombic System.

a. Sections parallel O without interference figures.

Name.

Chemical
comp . and
reactions.

Specipc

Gravity.

Cleavage.

Unsual co7nbi-
naiions Crform
of sections.

Twins.

Optical deter
minants.

Double re-
-frcition.

I . Olivine

(Crysolite)

Si 0.
+ Fe,,SiO,'
Rather
easily solu-
ble in HCl
with sepa-
ration of
gelatinous
silica.

3-2-3-4

Complete
in i-i, in
complete-
in i-I, con
choidal
fracture.
In sections
usually
curved
crevices.

i

1

Tabular crys-
tals I. I-i.
i-i, hexagonal
sections.

I=i39°2^
[-4^76° 54C
or large roun-
ded grains.

i

1

1

Very rare
I-i and in-
terpene-
trating.

Acute bisec-
trix at right
angles to i-i.
a=c

b=a p<ov.
c^=&

Positive,

strong.

(3. sections parallel 0 with interference
aa. disappearance of positive

I . Sillima-
nite .

Al, SiO^.
Insoluble.

I

3-23-3-24

Parallel
i-i ; frac-
ture of
thin nee-
dles in 0.

Columnar.

1= iii° :

Optical axis
plane !| i-i.
acute bisec-
trix at right
angles to 0;
c^=C
b=a

Strong,

positive.

2. Stauro-
lite.

H2 R3

(Al2)g Sig
034-

R=3Fe+

Mg.

Insoluble.

3-34-

3-37

i-i com-
plete;

I

incom-
plete; frac-
ture in 0.

Rarely in ir-
regular
grains, crys-
tals I. i-i. 0
1=128° 42^.

Interpene-
trating
twins, ver
tical axes
inclined or
. vertical,
rarely mi
croscopic.

As above,
(dispersion
feeble p'P>v).

As above.
Pleochro-
ism strong
C=dark
brown
a=b=
light yel-
low.

3. Ensta-
1 tile.

Mg Si Og
Soluble
very
slightly.

3I-3-29
(3- 153)-

I

complete ;
i-i i-i lon-
gitudinal
sections
seem fib-
rous frac-
ture. 0.

Long column-
ar I. i-i. i-i.
m-i, 8 -sided
cross sections
with two pairs
of longer
sides, like mo-
noclinic au-
gite.

When 1=^92°
in front the
optical axis
plane=i-i
acute bisec-
trix at right
angles to O,
c^=C b=b
a=a.

Positive
rather
strong,
feebler
than iu
monoclin-
ic augite.

TABLE IX.

Colors of
polarisa-
tion

Color and
inex of
fraction .

Structure.

Association

Inclusions.

Alterations

Occurrence

Remarks.

More bril-
liant than
augite.

In sections
colorless,
rarely
green.
Strongly in
relief.

,1^^1.678.

Surface of sec
tions rough,
changes in the
crevices to red
dish, brown-
ish, or green-
ish serpentine
and has pico
tite inclusions.

Either well
defined crys
tals or frag-
ments or ir-
regular grains.

With oliv-
ine, plagi-
oclase, ne-
pheline,
leucite,
horn -
blende,
and bio tite
Almost
never with
primary
quartz or
orlhoclase

Rather
poor, aside
from mi
nute pico
tile octa-
hedrons,
glass and,
more rare-
ly, fluid in-
clusions,
magnetite

Usually
into ser-
pentine,
also into a
brown, fi-
brous ag
gregate.
Pseudo -
morphs of
calcite af
ter olivine
in picrite.
Formation
of limon-
ite.

As prima-
ry essen
tial compo
nent o( all
basic rock.
In olivine
stone and
picrite,
melapyre,
olivine-
gabbro, ol-
ivine no
rite, oliv-
ine di’base
Also in cer
tain mica
ceous por
phyries.

Distinguished
Irom quartz in
isotropous
sections, from
zoisite by crys-
talline form
(not in nee-
dles) and col-
ors of polari-
zation, from
augite by
cleavage, from
sanidine by
rough surface
and brilliant
colors of po-
larization.

figureSs double refractive positive,
bisectrix (-]-) in 0.

Very bril-
liant

About as
in musco
vite.

1

1

Light or
dark yel-
lowish
brown,
strong re-
lief.

I. ,66.

In exceeding
ly slender
long needles-
often numer
ous or lelted
in parallel
masses in
quartz, cor
dierite. etc.

With
quartz or
thoclase,
biotite,
and mus-
covite.

Very poor;
fluid in-
clusions.

As prima-
ry, acces-
sory com
ponent of
crystalline
slates; rare

Distinguished
from zoisite
by double re-
fraction and
])olarization
colors, from
andalusite by
double refrac-
tion and
cleavage.

Primary
accessory
in crystal-
line slates,
particular-
ly mica
schist

As above.

Light or
dark
brown.
(3p=
1,7526.

Large and
small crystals,
characterized
by many in-
clusions.

With

quartz, or-
thoclase,
mica, and
garnet.

Minute
quartz
grains, bi-
tumen,
specular
iron.

Easily distin-
guished by
pleochroism.

in basic
p’rphyritic
erup lives
as essential
and acces
sory. With
olivine
stone.
Rarely in
quartz -
bearing
rocks, as
quartz por
phyry,dia-
ba.'-e por-
phyry. also
in gabbro
and norite.

Distinguished
from olivine
by fibrous
structure par-
allel to c. It
does not occur
in minute nee-
dles as si lima-
nite. Diflers
from the fal-
lowing only in
absence of
iron.

Very bril-
liant.

Colorless
to green,
strong re-
lief.

In irregular
long columns.
Often coalesc-
ed parallel to
c with mono-
clinic augite.

With pla-
^ioclase,
olivine,
and mono-
clinic au-
gite.

Very poor.

Into ser-
pentine
with for-
mation ot
talc. Into
basite.

Natne.

Chem.
Comp and
Reactions

Specif.

Grav.

Cleav-

age.

Usual combi
nations and
form ofseds.

Twins.

Optical
detemninants .

Double

refraction.

4. Bronz-
ite.

m (Mg Si
O3)

-|- n [Fe Si
O3]

Insoluble.

3-3-5

(3-12-3.25)

Com-

plete-

I

and
partial
in i-i.

Long col-
umnar

I . i-i .
i-i prevail-
ing.

very similar
to mono
clinic augite

Repeated
twinning in
giving the
cleavage
plates in i-i a
wavy appear-
ance. ‘'Knee”-
shaped twins
in m-i in
stellate groups
occur rarely in
porphyritic
eruptives.

As in
enstatite.

Positive.

Sections
paralel to 0.
& i-i sho w
simply an
open cross
with traces
of Lemnisci.

Sections
perpendic-
ular to an
optical axis
show one
ring or none

5. Antho-
phyllite.

n Mg Si Oo
4-FeSi O3
Insoluble.

3-187-

3-325

i-I

I

i-b

incom-

plete.

In foli-

aceous

masses rare-
ly in crys-
tals. Sec-
tions as in
monoclinic
hornblende.

Optical axial
plane parallel
i-i acute bisec-
trix at right
angles to 0
c^=C
b=h
a=a

Positive,

strong.

bb.

Disappearance of obtuse

1. Hyp
ersthe7te.

2 . Proto-
basite

and

basite.

(See

below.)

As in
Bronzite
but with
more iron.

3-3-3-4

I

com-

plete

i-i

con-
choidal
frac-
ture i-i
incom-
plete
1==
about
92°

Large irreg-
ular grains
and minute
columns
with the
combinati’n

I . i-i. i-i,
oXsoyi-l. 2-1
3-2-3-2-

Knee-shaped
twins as in
bronzite.

Opt axis plane
parallel i-i
obtuse bisec-
trix at right
angles to O
acutebisectrix
at right
angles to
i-i
c^=c
b=b
a=a

Large axial
angle.

Parallel to
0 positive,
to i-i neg-
ative, fee
bier than in
mono- clinic
augite.

Protohasite (diaclasite) and basite have the same composition as bronzite -f- H2 O. In
sharply defined crystals, columnar grains and irregular scales. Cleavage i-i and 1. Opt. axis
plane || i-i. obtuse bisectrix at right angles to O , the acute bisectrix to i-i. Specif, grav. of
protobasite 3 054, of basite 2. 6-2. 8; the former is is light yellow, with rather brilliant polari-
zation. In gabbro and porph. augite-bearing plagioclase rocks, changes to basite which is
dirty light green, and is always a product of decay of rhombic augite.

TABLE X.

Colors

ofpolar-

izatioii.

Color
and Re-
fraction.

Striiclure.

Associa-

tion.

Inclusions.

Altej'a-

tlons.

Occurrence.

Remarks.

In ter -
ferance
colors
not
nearly
as bril-
liant as
in mon-
oclinic
augite.

1.639

Dark

brown.

Slight

pleochroism

Partly in
large ir-
regular
grains in
coarsely
granular
rocks part-
ly in sharp-
ly defined
crystals in
porphyrit-
ic erup-
tives.

\

With
olivine,
plagio-
clase,
mono •

clinic
augite,
magne-
tite. as
enstatite

Inclusions ot
brown rect-
angular plates
or opaque
needles paral-
lel to i-i.

\

Into a

1 green
fibrous
i aggre-
gate as
basite
with sep-
aration of
Fe.^ or

Fe; 0, .

As enstatite.
01 ten replac-
ing nionoclin-
ic augite as es-
sential. Also
in later basic
eruptives and
coarsely gran-
ular older
rocks.

Distinguished
from augite
only by study
of transverse
section and
perpendicular
extinction in
longit. sec-
tions from
hypersthene
by pleochro-
ism and d’ble,
refract., from
hornblende
and biotite by
absence of
strong pleo-
chroism.

Bril-
i liant.

Dark brown
/3p=i.636,
relief faint
strongly
pleocroic.
Parallel to
c greenish
yellow, at
right angles
reddish
brown.

Inclusions
as in
bronzite,
longit sec-
tions seem-
ing fibrous
on account
of cleav-
age.

With
olivine,
plagio- ,
clase,
augite,
and
horn-
blende.

Minute brown
and green
regularly ar-
ranged scales
like mica.
Otherwise
poor in inclu-
sions, magne-
tite.

V ery rare,
accessory as
secondary
product of de-
composition of
olivine in
gabbro and
olivine stone.

Distinguisha-
ble from bio-
tite by cleav-
age amt, of
pleochroism
and size of
axial angle.

bisectrix (-|-) in 0. j

Rather

bril-

liant.

cf.

Bronz-

ite.

Light 01
dark brown,
black by
inclusions.
/3= 1.639
Pleochroism
strong. Axial
colors a=
hyacinth red
b=reddish
brown.
C=grayish
green.
c^>a>b ,

In large
irregular
grains in
granular
older
rocks, in
small crys-
tals in
later

porphyrit-
ic erup-
tives.

With

plagio-

clase,

olivine,

and

mono-

clinic

augite.

In the granu-
lar varieties •
innumerable
broun or vio-
let rectangu-
lar scales in
the cleavage
lines parallel
i-i. In crys-
tals regularly
arranged
opaque
needles other-
wise poor.

Decom-
poses into
fibrous
aggre-
gate par-
allel to
axis
with
dirty
brown or
green
color, as
enstatite.

In grains in
gabbro. nor-
ites, in later
eruptives,*par-
ticularly au-
gite andesite
and in feld-
spathic basalts
poor in olivine
as primary
necessarycom-
ponent and
with mono-
clinic augite.

Distinguished
from mono-
clinic augite
only by effects
of convergent:
polarized
light, from
bronzite by
strong pleo- j
chroism. !

1

The three rhoixibic augites — enstatite, bronzite and hypersthene are chiefly distinguished
by variation in amt. of iron, accompanying which a variation in angle of the optical axes lying^
in the plane i-i. Rhombic augites distinguished from monoclinic by inferior brilliancy of
polarization and feebler double refraction. Isotropous sections perpendic. to opt. axis in mono-
clinic augite exhibit two or three rings and bands while the rhombic at most one and also
lacks polysynthetic twinning | i-I.

}' In sections | to 0 the axial interferance
aa. Disappearance of the acute

Ffame.

Chem.
Comp, and
reactions.

Specif.

Grav.

Cleavage.

Usual com-
binations Cf
form of Secs.

Tzuins

Opticial

determtnants

Double

Refract

Colors
of Po-
larizn.

1. Andalusite.
Chiastolite is a
variety with sp.
grav. 2.9-3. 1,
characterized by
regularly ar-
ranged particles
of carbon in the
centre and four
angles Occurs
in metamorphic
slates.

( AI2) Si O5
Insoluble.

3.10-

3-17

Prismatic
in I.
Incom-
plete in
i-i, i-i
and I-i .
1=90°
50^

Fracture

II 0.

Long col
umns I . 0 .

I-i, more
rarely gran-
ular. Trans-
verse sec-
tions quad-
ratic, longit.

sections

rectangular

i

Opt. axis
plane |j i-i .
Acute
bisectrix
^0 .
c=a
b=b
a-=c

Axial angle
consider-
able.

Nega-

tive,

strong.

Bril-

liant.

2. Cordierite.
(Dichroite)
Finite is a de-
composition
product of the
above, consisting
of minute fibres
and scales.

Mg.2 (R.,)
Sis 0]8
(R.) = Al,
Fe,

Almost

insoluble.

!

!

2-59-

2.66

i-i

In comp.
I-i . 1=

119° lO''.

In large
grains and
crystals.

I . i-i . 0 .
Hexagonal
cross sec-
tions, rect-
agonal
longit.
sections.

Inter-
pene-
trating
twins
mult;i-
ples in
I, more
rarely
in i-3

Opt. axis
plane || i-i .

Acute bi-
sectrix-L-O.
c''=a
b=c

p<y

Nega-

tive,

feeble.

Bril-
liant as
in

quartz.

bb.

Disappearance of obtuse

1 7.oisite.

H2 Ca^
(AI2) 3 Si,j
^26

Soluble
with diffi-
culty with
separation
of gelatin-
ous silica.

3.22-

3-36

i-i

Very

complete

Fracture

parallel

0.

Elongated
grains and
long, trans-
versely
jointed
columns.

I . i-i ,
I--ii6° 26^

Opt. axis
plane || i-i
always
a^=C=+
b=b {pfy)
c'’=a or
when Opt.
oxis plane

II 0

b— a ipf>v)

c/=b .

Feeble

Bluish

gi'ay,

not

bril-

liant

usual-

ly-

''^Finite. Large crystals = I . i-i . i-i . O . Polarizes as an aggregate. Occurs with
quartz, orthoclase and biotite, Easily recognized macroscopically by the character of
decomposition.

figure is visible; durable refraction negathe. TABLE XI.

bisectrix, in O negative.

Color Cf
refract.

Structure.

Association

Inclusions

Alterations

Occurrence.

Remarks.

Colorless.

flesh

colored,

relief

strong.

/3p=

1.63S

Pleochi'o-

ism.

a=dark
blood red
h=oil
green
c=olive
green.
c>b>a.

Rarely in
grains, almost
always colum-
nar like stau-
rolite. Often
so full of in-
clusions as to
obscure the
andalusite.
Often in radi-
ating aggre-
gates of long
needles.

With

quartz,

orthoclase.

biotite,

muscovite.

Sometimes
poor, often
as in met-
amorphic
slates, rich
in quartz
grains,
bitumen
and scales
of biotite

Often into
greenish
fibrous
aggregates

Primary ac-
cessory in
granite and
cryst. slates,
as metamor-
ph. mineral in
contact
schists, etc.

Distinguished from
augite by pleochro-
ism and perpendic-
ular extinction;
from enstatite by
character of double
refraction; from
hypersthene by col-
or and double re-
fraction, from zoi-
cite by pleochroism,
form of sections
etc.; more difficult
to distinguish from
sillimanite which,
however, occurs in
minute needles.

Violet
blue, col-
orless in
very thin
sections.

1.56
a=yel-
lowish
white,
16= berlin
blue.
b>a>cC

Never in
microlites. In
large round
grains or small
crystals (in
eruptive
rocks.) Amet-
amorphic
mineral.

With

quartz, or-
thoclase,
and biotite
With
quartz
sanidine,
pleonast,
and corun-
dum.

Fluid in-
clusions,
sillimanite
needles,
pleonast
crystals,
zircon,
gl-assy in-
clusions.

Very fre
quent, par-
ticularly
when oc-
curing in
grains.
Changes to
a fibrous
green ag-
gregate re-
sembling
andalusite
(pinite) .

Rare, as ac
cessory, pri-
mary constit-
uent of gran-
ite, quartz^ —
porphry
(pinite) and
in grains in
gneiss. Rarely
in Trachytes
and trachytic
volcanics.

In thin sections
much resembling
quartz, but may be
distinguished by the
decomposition.

bisectrix in 0 (negative.)

Colorless-

white.

/?p=i.7o

relief

strong.

The trans-
verse fractures
of the long
columns is
characteristic,
also the inclu-
sions.

With
quartz,
ompha-
cite,garnet
mica, and
horn-
blende.

Fluid in-
clusions
are nu-
merous.

Frequent-
ly cloudy
on the
edges.

Frequent in
crystalline
slates as
eclogites and
particularly
amphibolites.

Easily distinguish’d
from apatite by op-
tical peculiarities,
from andalusite by
cleavage in O , and
the pleochroism and
colors of polarizat’n.
Never microlitic as
Sillimanite. It dif-
fers irom olivine in
crystal form, etc .

II. b. 2. Monoclinic minerals.

a. Apparently hexagonal (or rhombic) ; highly perfect cleavage parallel O.

Name.

I Chemical
comp, and
reactions.

Specific

gravity

Cleavage.

Usual combi-
nations and
form of sec's.

Twins.

Optical deter
minants.

Dotdde re
fraction.

i.Mica Group

Mixture of

28-3.2

11 0 very

I almost 120°

Rare.

Opt. axial

N egative.

a. Meroxene.

(Ala)^

perfect.

I. i-P. 0.

Twin-

plane j i-i^

'Apparent-

{Biotite)

iSi, H3 0,,

Separati’g

Thin plates or

j niiig

and parallel

ly perpen-

b. Rubelane.

and Mg^3

in -1-3^

short columns.

j plane

two opposite

dicular ex-

Differs in the

Si,. 0.^^ in

and

Sections par

I. Indi

sides of the

tinction &

brownish red

ratio of

(i-i) cor-

allel to 0 are

vidu’ls

hexagon

small axial

or seal red col

i:i or 1:2

respondi’g

hexagonal

distort'd

Acute bisec-

angle

or from biotite

(Tscher-

to sliding

plates without

so as to

trix vary-

make it

of which it

mak) De-

or pres

fracture lines.

be at-

ing little from

appear

seems to be a

composed

sure

Often with

tached

the per pen

hexagonal

pyrogene pro-

by H., SO,

planes.

sliding planes

in a !

dicular to 0.

Cross sec-

duct of altera-

c’mpletely

and three sys-

plane al-|

Axial angle

tions ap-

tion. Occurs

with for-

tems of lines

most par

usually very

parently

in basalts and

Illation of

intersecting at

allel to

small =c^°-

isotropous

lava.

skeleton of

60°. The Ion

0. Often

1.3°, variable,-

In con-

c. Phlogopite.

silica.

gitudinal sec

inPrlam-

occasionally

vergent

Can be distin-

tion rectangu

ellated

large, varying

polarized

guished by

lar with nu-

when

with the

light appa-

chemical an-

merous cleav

only rec-

amount of

rently hex-

alysis and the

age lines par-

ogniza

iron. Disp.

agonal.

yellow or light

allel to axis U .

ble in po

p<u.

brown color

larized

A magnesia

light. ]

mica nearly

According

Optical axis

free'from iron

to Tscher-

As in

As in merox-

1

planes -I- i-i'

Negative.

mak, a

meroxene.

ene.

a almost -L 0.

Extinction

d. Anomite\N\y.\.wx& of

i

Axial angle

perpendic-

(Biotite-pars)

H, K,

12-16° Disp.

ular.

1 (Al.,h, Si,

v<p.

e. Muscovite

0-24 and

2.76-

Very per

Rarely crys-

!

(and Sericite)

I Mgi2 Si,

3-1

feet paral-

tallized in

As me-

Optical axis

Negative,

O24 in ra-

lel to 0 .

rocks. Six

roxene.

plane i-i^ a

strong.

tio i: I or

Sliding

sided plates.

i

slightly varies

Extinction

2:1.

i

planes.

from U, a al-

perpen-

most -^,.to 0

dicular.

; H4 K2

1

Disp pP>v.

Apparent-

(AI2 ), Si,

1

axial angle

ly rhomb-

O24. Insol-

usually large.

ic.

uble.

1

60-70°.

H2 Mg3

2. Talc.

Si4 O12.

2.69-

Perfect

Never in crys-

Optical axis

Negative,

i

Unattack-

2.8

11 Oj (in-

tals, in rocks

j

plane || i-i^, ||

feeble.

ed by

complete

usually as mi-

■

to a line of

Extinction

acids. Al-

I-)

nute irregular

fracture, a

apparent-

3. Chlorite

kaline re

plates like

almost at -J-

ly rhomb-

Grotip.

action.

mica.

i

to 0.

ic.

a. Ripidolite

Mixture

1

(b. Clinoch

of p(2 H2

2,7-

Perfect

Scales and

t

Although oft-

Negative,

lor mon’clinic

0. 3MgO

2*95-

II 0.

hexagonal

en seeming

feeble.

habit, strong

2 Si O2 ) +

plates I. 0. as

hexagonal yet

pleochroism.

y(2H2 0.

though hex-

sometimes

Semicryst.

2Mg 0

agonal. If

1 (

obviously bi-

and metamor-

AI2 O3 Si

monoclinic I.

,

axial with

phic.) ;

O2 ).

i-P.O.

small axial

1

angle a-^O.

TABLE XII.

Colors of
polarisa-
tion

Color ana
index of re
fraction.

r

Structure.

Association

: Inclusions.

Alterations

Occurrence

’ Remarks.

Not par
ticularly
brilliant.
Browns.
In thin
plates ir-
ridescent,
carmine
red.

Brown
black,
dark green
f3=i.6i.
Pleochro-
ism strong
in long’t.
sections a
and b near
ly alike

In sections
parallel to
c — axis
a=yellow-
bright
brown, at
right an-
gles c
C=brown-
black.
c>b>«.

Primary, as
large crystals
(in eruptive
rocks) fre-
quently frag-
mentary or
with opaque
margin,
(comp, of
first order) ;
also in minute
scales particu-
larly in crys-
talline slates
or scattered
through the
magma, as in
basalts, etc.
(comp of sec-
ond order.

Usually

with

quartz and
ortho-
clase, also
with horn-
blende,
and more
rar’Iy with
augite and
olivine.

Generally
free from
inclusions,
but not
rarely
with fas
ciculate
masses of
epidote
needles or
regularly
arranged
slender
needles of
rutile.

Into chlo-
rite like
mineral,
with epi
dote and
calcite
Loses its
brown col-
or, be-
comes
green, cal-
cite pene
trates be
tween the
scales. nee
dies of ep-
idote ap-
pear. Also
formation
of limon-
ite or mag-
netite on
periphery.

In nearly
all rocks.
In many
as neces-
sary pri-
mary con-
stituent,
one ot the
first to ap-
pear of the
minerals.
Product of
alteration
of augite,
horn-
blende,
rarely ol-
ivine.
Contact
mineral in
metamor-
phic slates

Easily recog-
nized by the
cleavage and
strong pleo-
chroism. Cross
sections not
pleochroic as
hornblende.
Not green as
chlorite, nor
fasciculate.

As merox-
ene.

Red-br'wn
Pleochro-
ism feeb
ler than in

meroxene.

With oliv-
ine and
actinolite.

Becoming
green to
colorless,
as above.

Rare in ol-
ivine store.

Difficult to
distinguish
microscopic-
ally from talc.
Sericite is but
an unctuous,
inelastic, light
green musco-
vite. which
occurs in ir-
regular scales
in certain
crystalline
slates.

Occurrence .

Primary in granites
(in particular in tour-
maline granites) and
crystalline slates, as
gneiss, mica schists
and slate. In no other
rocks primary but as
product of alteration
in feldspars, chiasto-
lite. liebenerite. etc.

Very bril-
iliant, irrid-
escent, red
to yellow.

Colorless,
light green
oil green.

As primary in
large plates
In fasciculate
and radiate
aggregate. As
secondary in
aggregates of
minute irreg
ular scales

In crystalline
slates.

With

quartz, or-
thoclase
tourma-
line.

Very poor
Rarely
needles of
rutile,
plates of
specular
iron, or
columns ol
tourma-
lin, or Zir-
con.

Colorless,

white,

light

green.

Usually in ir
regularly felt
ed or rosette-
shaped radi-
ating aggre-
gates of mi-
nute scales.

With

quartz, or-
thoclase,
mica or
with aug-
ite and
olivine.

Very poor,
biotite, ac-
tinolite.
As musco-
vite.

A primary constit
ent in many crystal-
line slates. Not abun-
dant Secondary pro-
duct of decomposition
of augites poor in iron
and hornblende, par-
ticularly Enstatite al ;
tered to olivine stone
and serpentine.

Microchemi-
cal treatment
of isolated
scales with
fluorosilicic
acid is the
surest test.

Not very
brilliant,
blue —
green.

Light to
dark green

^^=i*5,75-
Pleochro-
ism feeble

Not in large
scales but like
talc as aggre
gates of mi-
nute irregular
scales radiate
or disperse.

With

quartz, or-
thoclase,
biotite
muscovite
as primary
const.

Poor. hem-
atite and
limonite,
needles of
actinolite
and rutile.

Also hel-
minth, pen-
nine. kaem-
mererite chlo-
ritoid, sism on-
line, and ott
relite. Rare.

Primary in chlorite
slate. Decomposition .
product of mica, au ,
gite. hornblende and ,
garnet. ,

^ 2. Crystals with

i aa. Optical axis plane -L i-F; perfect

Name.

Chem.
Comp and
Reactions.

Specif.

Grav.

Cleav-

age.

Usual combina-
tions and fo7'm
of sections.

Twins.

Optical

determinants.

Double

refraction.

I a. Or-
thoclasc

K,(Al,)Si,

^16 •

Not

attached
by acids.

2.50-2.59

(2-57)

1

Very
perfect
Be-
tween
0 and
i-i^
angle
89° ArO'

In grains or
columnar,

0 . i-F . I .

2-i . 2-F . I .

Sometimes tab-
ular or more
rarely, in min-
ute crystals.

1 F I . 0 .
2-i . i-i .

Frequent.

(1) Oftenest
according
to Karlsbad
type. Twin-
ning plane

1- i.

(2) Baveno
type. Twin
ning plant

2- i^.

(2) Rarel)
Manebach
type.

Optical axis
plane inclined
to 0 forming an
an angle of tf
I with vertical
axis.

C=b

a : a = 5“
Real axial angle
=69°.

In sections || i-F
or i-i a distorted
bisxial inter-
ferance figure
visible in con-
vergent pol.
light.

Negative,

rather

strong.

' In sections

1 i-i^ one
direction of
extinction
varies from
the angle

0 . i-i
(=a . a)
by 5° 18^
Sections in
zone 0 . i-i
extinguish
perpendic-
ularly.

1 b.
Sani-
dtne.

As

above.
Full of
rifts.

In slender rods
or large crystals,
almost never
granular. Sec-
tiuns 11 0 and i-i
elongate bands
truncate or
acute at the
ends, II i-F dis
torted hexagons
with sides cor-
responding to

0 . I . i-i .

In the columnar
type, sections
rectangular if
perpendicular to
0 . i-F , if 2-i^
is present
octagonal.

Twinning

plane=

0.

If parallel i-F
B=b

a : a=50°.

Monoclinic Habitus.

cleavage 1| O and i-i^; angle about 90°. TABLE XIII.

Colors of
Folaj'iza-
ti07l.

Color.

Sii'ucture.

Association.

Inclu-

siofis.

Altera-

tions.

Occurrence.

Reinaj'ks .

Rather
brilliant,
but less
than as
quartz.
In thin
sections
often
less bril-
liant,
bluish
gray as in
nepheline

General-
ly cloudy
white or
gray,
rarely
clear.
Colored
red by
limonite.

In large crys-
tals or grains
of the first
order, more
rarely in small
grains or rods
in eruptive
rocks. Often
coalesced
with plagio-
clase. Zonary
structure is
rare as is
zonal arrange-
ment of in-
clusions.

With
quartz,
biotite,
muscovite,
hornblende
and rarely
with augite.
plagioclase
and

elseolite.

In

general

poor.

Specular

iron,

biotite

scales,

fluid

inclu-

sions,

needles

of

apatite,

zircon.

Kaolini

zation

with

forma-

tion.

of musco-
vite or
epidote.

One of the
most abun-
dant compo-
nents in gran-
ular and por-
phyritic older
eruptives.
Essential
comp, in
granite, syen-
ite. quartz
porphyry and
accessoi-y in
nearly all
plagioclase
rocks. Also
in crystalline
slates as
gneiss, here
often glas-y
like sanidine

Large crystals
may be recog-
nized by
twinning in
sections par-
allel to 0 and
i-i and by the
oblique ex-
tinction paral-
lel i-E. Mi-
nute rods of it
and sanidine
in the magma
of rocks often
greatly re-
semble neph-
eline and cer-
tain melilites,
Orthoclase
lacks, how-
ever, the iso-
tropous hex-
agonal sec-
tions

From plagio-
clase it may
be distin-
guished by
absence of the
polysynthetic
twins of the
latter.

Colorless

clear.

/3 p=

1-5237

In eruptive
rocks as large
crystals of
first order and
minute rods
second order.

The large
crystals often
fractured.

Zonary

structure.

As

orthoclase
a'so with
nepheline
and leucite
but never
with

muscovite.

Very

rich.

Gla.ss in-
clusions,
usually
zonal in
arrange
merit,
augite
micro-
lites and
needles
of apatite

Almost
always
unaltered
Into opal
in ande-
sites and
trachytes

Essential
comp, (pri-
mary) in
trachytes,
rhyolites,
phonolite,
and the glass
of orthoclase
rocks. In
nearly all
later plagio-
clase rocks.

bb. Optical axial plaiie || i-V ; perfect cleavage in 1=87°.

Name.

Chemical
comp . and
reactions.

Specif.

Gray.

Cleavage.

Unsual combi-
nations of form
of sections.

Twins.

Optical deter-
minants.

Double re-
fraction.

I . Mono-

3 17-

Perfect

Rarely in

Very fre-

Optical axis

Positive,

clinic All-

R Si Qg

3-41

I

grains crys-

quent.

plane || i-i^.

“ strong.

^ite Group

R=-Mg.

tals I, i— i. i-i^.

twinning

acute bisectrix

Extinction

a. Common

Ca, Fe,

I and i-i. 0,

plane i-i,

in the ob-

in sections

and basalt

and Fes

3-34-

_i,I=87°6'

also in pol-

tuse angle j3.

II b per-

ic augite.

O3 AI2 O3

3-38.

Sections per

ysinthetic

h=hC

pf^ndicu

According

pendicular to

twins.

The positive

lar; in sec-

to Tscher-

c octagonal

More rare-

axial angle

tions in-

mak a

with evident

ly inter-

enlarges with

clined to

mixture of

prismatic

penetrat-

the amount of

i-i^ C: c

Ca Mg Si-2

cleavage.

ing twins

iron in rhomb-

becomes

Og-j-Ca Fe

Longitudinal

in a plane

ic augite.

smaller

Sis

section dis-

of— I-i or

about 60°.

until it

Mg AI2 Si

torted hexag

1-2' .

Sections | i-i

reaches 0

Og Scarce-

onal, with

and perpen-

when par-

ly attacked

cleavage lines

dicular to c

allel to i-i

by acids.

parallel to i-i^

[show the dis

In sections

quadrangular

'appearance of

II i-F C:

often rhomb-

an optical

c=39° 54°

ic.

axis in almost
the middle of
the field.

a:a=22°.

b. Dial-

do

3-23-

1(87°),

\

do i

do

do

lage.

3-34

shelly
fracture in

1

1

i-i.

i

i

c. Ompha-

do

3-3

As in au-

Only in

cite.

with more

gite, frac-

grains.

rare

do

do

AI2 O3

d6

ture less
perfect
than in di-
allage.

do

do

do

do

d. Diop-

more CaO

side.

than MgO

poor in

Also in long

AI-2 O3

columns with

transverse

do

do

do

Fracture

fracture,

in 0 be-

usually not

e. Salile.

poor in

3-2-

sides the

terminated.

iron.

3-33-

above.

Section as in
augite.

TABLE XIK

Colors

ofpolar-

ization.

do

In section
green to
brown,
often vio-
let brown
in basalt.
The same
crystal
often ex-
hibiting
several
colois.
Pleochro-
ism usual-
ly feeble.
In phono-
lite it may
be strong.
c>a>b.

do

do

Very

bril-

liant*

Color
and Re-
fraction

Structure,

Greenish
brown.
Pleochro-
ism very
feeble.

Grass

3;reen.

do

Light
green — ■
colorless.
Relief
strong.

In large
crystals
(L O.)
with zonal
alt’rnating
colors. In
twins
these
bands pass
through;
both. Oft-
en with so-
called
“hour-
glass”
form. when
sections
parallel to
i-i fall into
I 4 areas. ^
Also in
J columns
and micro-
lites(II.O,)
crystals
often in
large ag-
gregates &
radial
groups

Chiefly
with pla-
gioclase,
nepheline,
leucite,
with or
without
olivine
and bio-
tite. Rare-
ly with
ortho-
clase, horn-
blende,
and
quartz.

Only as
large ir-
regular
grains. In
inclusions,
in fibrous
and twin
ning char-
acters
much as
bronzite.
Often co-
alesced
with ordi-
nary aug-
ite, horn-
blende or

Only in un
altered
gr’ins poor
in inclu-
sions. Oft-
en coalesc
ed with
horn-
blende.

Association

Inclusions.

Abundant
glass inclu-
sions, apa-
tite nee-
dles and
magnetite.

Decomposition.

With pla-
gioclase,
common
augite, ol-
ivine,
horn-
blende,
and rarely
with
quartz.

(c) With
quartz,
horn-
blende,
garnet, zo-
isite, dis-
thene, and
rutile.

(d_) With
olivine,
chromite,
diallage, &
rhombic
augite.

(e) quartz,
horn-
blende,
scapolite,
plagio-
clase, and
titanite.

Like
bronzite
with inclu-
sions of
brown
scales of
goethite?
parallel to
i-i. other-
wise poor
in inclu-
sions.

(c) Rare,
fluid and

rutile nee
dies.

(d) Rarely
glass in-
clusions.

Into chlorite,
calcite, limon-
ite. epidote
and quartz,
ps’udomorphs
of any of these
after augite.

Into opal.
More rarely
into horn-
blende, the
form being re-
tained but the
cleavage that
of hornblende.
Into serpen-
tine with talc
and chlorite.

At the ends
changes into
dark green
strongly pie-
ochroic horn-
blende fibres.
Into viridite,
also serpen-
tine with for-
mation of
chlorite and
talc.

Occurrence.

Later porphy-
ritic eruptives
as essential
and primary,
in diabase,
augite ande-
site, and all
basalts, also
andesites, tra-
chytes. phon-
olites. Rarely
in large grains
in older erupt-
ives and crys-
talline slates.

Primary abun-
dant in gab-
bro, norite,
rare porphyr
itic eruptives.

In olivine
stone and ser-
pentine. Rare
in crystalline
slates.

(c) In eclcg-
ite and am-
phibolite

(d) In olivine
stone (prima-
ry) rarely sec-
ondary altera-
tion of garnet.

(e) In crystal-
line slates.

Remarks.

Easily recog-
nized by ob-
liquity of ex-
tinction of c.‘
c. the prismat-
ic cleavage
with angle of
87°, especially
in cross sec-
tion. Liable
to be confused
with horn
blende in sec-
tions inclined
to c. When
augite is near-
ly colorless its
polarization
colors are;
vivid and like
olivine.

Often similar
to bronzite
in sections or
plates parallel
to i-i easily
recognized.

Colors lighter
than in augite
proper (less
iron). Differ
from diallage
in absence of
complete
fracture in

Name.

Chem.

Comp, and
reactions.

Specif.

Gray.

Cleavage.

Usual com-
binations Sf
form of Secs.

Twins

Opticial

determinants

Dcmble

Refract.

Colors of
Polariza-
tion.

f. Acmite.

Na2 (Fe2 )

3*53-

Complete

In grains or

i-i

As augite.

As

As

Si, 0,,

3-55

I 87°,

long flat-

fre-

augite.

augite.

incom-

tened col-

quent. 1

plete

umns

Pleochro-

i-i.

(planes i-i

ism rath-

being

i

1

er strong.

largest.)

1

1

C=dark

■

I . i-i . i-F

i

brown.

■

1

1

1

a=

1

1

brownish

g. Wallas-

Ca Si 0.,

2. 78-

Parallel

1=87°

do

Opt. axis

Positive,

green.

Ionite.

Completely

2.91

i-i, 0

Almost

plane

strong, c

cf>hf>U

decompos’d

and I-i

always in

11 i-i^-

forms an

separating

irregular

Apparent

angle with

Very

galatinous

flbrous

axial

Oof32°-I2^

brilliant.

silica.

long prisms

i

angle = 70°

a : c--=i2°

cc.

Complete

1

2 . Horn

mRSi O.,

31-

I very

I . i-i^ . i-i

Fre-

Opt. axis

Negative,

Less

blende \

n ( R2 ) 0., .

3-3

perfect

and 0 . I or

quent

plane || i-F.

rather less

brilliant

Group. !

R=Ca, Mg

with

I— F almost

I i-i

Acute bisec-

strong than

than in

Commondf'i

Fe.

angle of

always in

trix=a

augite.

augite.

Basaltic

R2 = (Al,)

124° iC;

crystals.

i

falls in the

Extinction :

yellow.

Hornblende

(Fes ).

i-i and

Cross sec-

!

obtuse

C: c= about

green.

[b. Smar-

When

i— i^

tions usual-

angle

13° (2-18°)

brown.

1 agdite

containing

imperfect

ly hexagons

h=h. Real

a : c---75°

1 Compare

much iron,

also octago-

i

axial angle

a : a^=29°

uralite. Oc-

attacked

nal, longit.

about 79°.

38^-

curs with

slightly by

sections as

Positive

c : C=I3-

omphacite

acids.

augite.

1

axial angle

garnet,

1

j

varying

in green.

zoisite. and

with amt

11-13° in

; rutile.]

of Fe. Opt.

brown

axis disap-

hornblende

i

Ca Mg3 Si,

3.026-

As

Long

More

pears on

jc. Actino-

Oi2+CaFe3

3.16

above.

columns

rarely.

edge of

1 lite.

Si, 0,.2

fracture

usually not

field

( £

(Techer-

trans-

terminated

j

j| 0 and i-i.

mak)

verse.

I . i-i"

p<fy

No Al.

little iron.

3MgSi03+

I

I . i-i

[C: c 15°]

d. Treino-

CaSi O3

2-93-3

as above'.

long

lite.

Preponder-

slender

( 6

Very

ating

columns.

£ £

brilliant.

%

Mg 0 .

(See next

Insoluble.

table.)

TABLE XV

Color etc.

Structure.

Association

Inclu-
sions .

Alterations.

Occurrence.

Remarks.

Dark

In large crys-

With elae-

Metallic

Not rare in

elaeolite-syenite,

brown-

tals in syenite,

olite, soda-

particles.

Phonolite,

and trachytes.

dark

often frayed

lite, micro-

green

at the end. In

line, and

/3=over

minute crys-

biotite.

(g) as product

(g) Very similar to

r.7.

tals yellow or

alteration of

tremolite, distin-

dark green in

contact miner-

guished by angles

trachytes and

al rare in

of the prisin and

phonolites.

granular

solubility .

limestones,

Difficult to distin-

Colorless

In fasciculate

With cal-

Fluid in-

which have

guish from zeolitic

yellowish

or radiate

cite, green

elusions.

been the re-

substances as

white.

aggregates.

augite.

sult of meta-

scolezite.

strong

granite.

merphism.

relief.

Rarely in

phonolite etc.

cleavage

1=124°.

Green-

In large crys

With

Poor.

Yellowish

Primary

Distinguished

brown.

tals or grains

orthoclase

P'luid in-

fibrous, epi-

essential in

from augite by

/? p=i.62

I . 0 . rarely

plagio-

clusions.

dote, calcite

granular and

prismatic cleavage

Pleochro-

in small crys

clase.

glass and

and limonite.

porphritic

angle, slight in-

ism rath-

tals and mi-

quartz, bi-

gas pores.

Often on the

eruptives, as

clination of c : c

er strong

croliths II. 0 .

otite rare-

Metallic

surface to

syenite, diorite

and strong pleo-

a= yel-

Green horn

ly with

particles

magnetite as

(green) por-

chroism. Biotite

lowish

blende often

augite and

and

augite. Into

phyrite, ande-

has not the cleav-

green or

fibrous, brown

olivine.

apatite

biotite, chlo-

site, trachyte

age and dichroism

honey

zonal. Green

needles.

rite.

(brown) .

in sections uarallel

yellow.

hornb. often

Accessory in

0

!6=yel-

coalesces with

Occurrence.

besalt (browm)

lowish

augite.

olivine stone

brown.

(c) Rather

(green) rare.

C=black

frequent in

In crystalline

or green-

certain crys-

slates (green)

ish brown

talline slates

abundant.

c>b>'a.

lacking feld-

Essential in

With

Very

spar as talc-

amphibolite

(c) Almost al-

Light to

Needles or

quartz,

poor.

mica-and

slates and

ways in long col-

dark

grains often

mica.

chlorite-

certain gneiss.

umns not in short

green.

fibrous.

chlorite

schists and in

crystals as in ordi-

pleochro-

and rutile.

serpentine.

nary hornblende.

ism"'

(d) As con-

feebler

tact mineral in

C=dark

With cal-

limestone. As

(d) compare

green.

In columns

cite, oli-

primary (rare-

wollastonite.

a=yel-

and fasiculate

vine, horn-

£ C

ly secondary)

lowish.

aggregates.

blende,

component in

and

slates and

Colorless

diallage.

serpentine.

(e.) Arfvedsonitc. Na2 (Fcg'' Si^ O12. Specif, gr. 3.33-3. 59- Occurs in large
grains cleaving in I, with orthoclase, microcline. elaeolite and sodalite, rarely in elaeolite
rocks. It is distinguished from hornblende by blue-green color and composition .

(b.) Glaucophane. Nag ( Alg ) Si4 O12 with Ca Mg. and Fe. Specif, gr. 3.1.
It is an indigo blue mineral with strong pleochroism occurring, in long fibrous needles

dd. Cleavage 1| O and i-i ; angle 115°.

Name.

Chemical
comp, and
reactio7is.

Specific

gravity

Cleavage.

Usual co7nbi-
nations and
form of sec's.

Twins.

Optical deter-
minants.

Double re-
fi'action.

Epidote.

H2 Ca4
( R2 )3 Sie
026-

3-32-

3-5

1

1 0 perfect
and i_i
forming
angle of
115° 24^

Extended in
the ortho-di-
agonal, gen-
erally small
columns I. 0.
i-i. i_i. Lon-
gitudinal sec-
tions 1 i_F
hexagonal.
Cross sections
II O: i_i elong
ate quadrang-
ular or ex-
tended hex-
agonal. Also
in grains.

Plane i_i
Rarely
micro-
scopic.

Optical axis
plane 1 i-i^
b=b acute
bisectrix =a
nearly coin -
cides with c.
Sections || to
i-i show a bi-
axial interfer-
ence figure. '

Negative,
strong.
Extinction
a: c=2°
20^,

c: U--=2fi
47^=c:0.

ee. Cleavage imperfect in I or

Titafiite.

Ca Si Ti
O5. De-
composed
by H-2 SO^

1 Ti O2 is
jdissolved,
and gyp-
! sum
formed.

3-T3-6

I 133° 55"

i-F 113°
30^ im-
perfect.

Usually crys-
talline I. 0.
/^(i-F.) Yz
(1-2") or
(1-2^). Or in
wedge-shaped
grains.

Rather
frequent
Contact
or inter
pene-
trating
twins in
plane O.

Optical axis
plane || i-i^
acute bisectrix
=<:almost per-
pendicular to
I-i) strong
dispersion of
axes.

Positive;
strong.
Extinction
a: c=39°
I7^a-a^=
21°.

1

1

Gypsum.

Ca SO4+
2 Aq. Sol-
uble in
acids with
difficulty.

2, 2-2.4

Complete
in the cli-
nodiago-
Inal, less so
-I.

In grains or
long colamnar
individuals.
Crystals I.

i-F. -I.

Rare in
micro-
scopic
individ-
uals.

Optical axis
plane || i-F
Acute bisect.
=«. One op-
tical axis al-
most -L i-i
forming with
c an angle of
83°, the other
an angle of
22°.

Negative

strong.

Extinc-

tion

a: c=52°

30^

C: c=37°
30C

often coalesced with hornblende, rarely in crystalline slates, eclogite, amphibolite, mica
and chlorite-slates.

(g ) Uralitc (Smaragdite in part) has the composition of honddende but has a
cleavage similar to augite. It is a product of the decomposition of augite and diallage.
It occurs in gabbros and serpentine as well as augite porphyry.

TABLE XVL

Colors of
pola riza-

ti07l.

Color and
index of re
fraction.

Structnre.

Association

1 Inclu-
sions.

! —

Very bril-

Citron yel-
low, yel-

In long mi-

With

V ery

liant, yel-

lowish

nute columns

quartz, or-

j poor.

low to red.

green.

in chloritic

thoclase,

1 Fluid

f-=1.72-

substance or

plagio -

! inclu-

1.75. Ple-

in pseudo -

clase.

isions.

ochroism
rather
strong in
thick col
ufnns.
a=-pale
yellow,
b=yellow-
ish green
C=green-
ish yellow.
6>c>a.

morphs, rare-
ly in grains.

i

j

I

horn -
blende, bi-
otite, aug-
ite and
chlorite.

'

j

Altera-

tions

Occurrence

Secondary
frequently
as decom
position
product of
feldspar,
horn-
blendes,
biotite,
rarely of
augite in
eruptives
& crystal-
line slates.
In the lat
ter also as
primary.

Re7narks.

Similar to au-
gite. Charac-
teristic is the
yellow color,
strong refrac-
tion and vivid
colors of po-
larization.

i-i^; acute wedge-shaped sections.

Not bril-
liant.

Faint yel-
low, red-
dish

! brown to
I colorless,
j Pleochro
I ism rather
j strong in
■dark varie-
I ties, a-=
j reddish
I brown,
C=green-
ish yellow

Very bril
liant, ir-
ridescent.

Colorless
or colored
by iron.

Surface of sec-
tion rough.
One of the
first minerals
to form in
eruptive
rocks.

With
quartz
plagio
clase. horn-
blende,au
gite, bio-
tite. chlor-
ite, quartz
and other
I accessory
minerals.

In minute
grains and
needles, rare-
!]y in crystals.

Rarely
with clas-
tic compo-
nents, as
quartz
grains or
scales of
mica.

Very

poor.

Rarely |As prims -
pseudo- |ry accesso-
morphs j ry in
of cal- I eruptives.
granite,
syenite
phonolite,
schists,
etc.

Andesite
diorile.

; cite af-
I ter ti
itanite.

Fluid

inclu-

sions.

As a sim
pie rock,
granular
or massive,

Easily recog
nized” by the
wedge-
shaped sec-
tions and
rough surface.

II. b. 3. Triclinic

a. Elongated columnar crystals, colorless or blue,

Name.

Che77i .
Comp, and
Reactions.

Specif.

Grav.

Cleavage.

Usual combina -
tio?is and for?n
of sections.

Tivins.

Optical deterrnmants.

Coloj's
of Polar
Ration.

D is them.
(Cyanite)

(Ag Si O5
Insoluble.

3-48-

3.68

■

Very

Perfect.

II •

Perfect

II i-i and

0.

Grains or col
umns i-i . i-i
with an angle
of io5° 15^,
rarely termi
nated. Cross
section quad-
rate (or hex-
agonal of i^-i
or i-G is ad-
ded.

1

Frequent.
Less so micro-
scopic. Either
multiples in
i-i or

(2) perpendic-
ular to c axis,
or

(3) to b axis, or

(4) parallel to

0.

Opt. axis plane makes
an angle of 30° with
the angle i-i : 0, with
the angle i-i . 0 an
angle of 60° 15^ and,
like the acute bisec-
trix = a stands at
nearly a right angle
with i-i, parallel to
which plane sections
show a biaxial inter-
ferance ^figure with
negative bisectrix.

Very

vivid.

b. Broad tabular crystals or grains, colorless.

Tricilnic
Feldspars
I. Micro-
cline
{fibrous
^ ortho-
clase.)

As

orthoclase

1

2.54-

2-57

Perfect

II 0 .
quite
perfect,

11 >

i-T^.

As orthoclase
i-i . 0 . i^-i
i-C predomi
nating.

Rare, |i i-i and
at right angles
to it. Almost
always inter-
lammellate
with ortho-
clase givingin
sections || O
the character-
istic “lattice
structure.”
Also polysyn-
thetic twins
with albite,
so that the 0
surfaces are
parallel in
each.

i

Opt. axis plane, al-
most -L 0, its sec-
tion with i-i forms
with the obtuse angle
0 . i-i 5-6° in the
obtuse angle ac
cleavage plates in i-i
show one axis . evi-
dently, the axial
plane is somewhat
oblique to i-i.

Very

.bril-

liant.

2. Plagio-
clase.
Feldspars
(a) Albite
[Ab]

N a^ AI2 Sig
Oxn

Traces of
Ca and K.

Not at-
tacked by
acids.

Si O2

68

2.61-

2.63

Complete
II 0 and
i-i

incom-
plete
i-i^ and
I. Angle
0 : i-i at
the right
="93° 36"

i-i . 0 . i^-i .

i-i^ . I-i . I
Very similar
to orthoclase

Opt. axis plane forms
an angle of 96° 16^
with the c axis, with
the perpendicular to
i-i 16° 17^ Acute bi-
sectrix = c. Disper-
sion slight, p<7r'.cleav-
age plates || i-i show
a complete distorted
interferance figure.

Usual-

ly.

quite
vivid,
not so
strong
as

quartz.
In very
thin

sec-

tions

feeble

blue-

g^ay.

Twins.

Almost always twinned.

( 1 ) Albite type i-i, and gen-
erally polysynthetic. Often
two such polysynthetic indi-
viduals are again twinned ac-
cording to the Carlsbad type.

(2) Percline type and these
again united on the Mane-
bach type.

(3) By a union of (i) and (2)
there results a lattice arrange-
ment reminding of micro-
cline.

Minerals. ' table xvii.

(or granular.) Cleavage in i-I, i-i, andO.

Double

refraction.

Color^ etc.

Structure.

Association.

Inclu-

sions.

Altera-

tions.

Occurrence.

Remarks .

Negative,
strong.
Extinction
in sections

il i-1

c : 0=^56°
vfp

Colorless
or sky
blue.
/Ip=1.72
strong re-
lief. If
blue, with
rather
strong
pleochro
ism.
C=blue
a=white

In long col-
umns or ir-
regular
grains with
crevices |
or 4- to
axis c.
Often com-
pletely or
mottled
blue. Rare
ly in aggre-
gates of
needles.

With
quartz,
mica,
garnet,
omphacite,
hornblende
rarely with
orthoclase.

Poor.

Fluid

inclu-

sions.

Rarely
mar-
gined,
by a
zone

of al-
tera-
tion.

Raie as primary
accessory in
crystalline slates
granulite, eclo-
gite and mica
schists.

If colorless,
only to be dis-
tinguished
from silliman-
ite by position
of axis of
elasticity.

Cleavage parallel to 0. and i-i.

Negative,

rather

strong.

In plates
parallel to
i-i positive.
Extinction
not perpen-
dicular but
oblique in
plates par-
allel to 0.

Colorless
Reliefnot
strong, as
in ortho-
clase.

i

In rocks
only as
grains,often
coalesced
with

quartz, as
in graphic
granite.

.(a) With
orthoclase,
elaeolite,
sodalite,
augite, and
hornblende
(b) With
quartz,
orthoclase,
biotite,
hornblende
&muscovite
(c) With the
above and
garnet and
, cyanite.

Usual-
ly very
poor.
Horn-
blende
biotite,
zircon,
apatite

Simi-
lar to
that of
ortho-
clase.

Primary essen-
tial with ortho-
clase in
(a) elaeolite-
syenite.

(b) in various
granites par-
ticularly in

graphic granite.

(c) Crystalline
slates as granu-
lite and gneiss.

Easily dis-
tinguished
from ortho-
clase by
extinction
oblique to

0 and
twinning;
from other
tnclinic
feldspars by
latticed
twinning
and optical
peculiarities.

Positive,
rather
strong. In
cleavage
plates II 0
extinction
inclined
with the
angle 0 :
i-i

+3° 54"-
+4° 51/;

+ 15° 33"-

4-20° .

Colorless

clear,

slight

relief.

^•537

In large
grains, rare-
ly in crys-
tals, often
coalesced
with ortho-
clase and
quartz In
eruptive
rocks in
slender
rods.

With cal_
cite, quartz,
mica and
orthoclase,
alsochlorite
and more
rarely
hornblende

I

i

1

V ery
poor,
fluid
inclu-
sions.

Rarely
altered
Be-
comes
cloudy
as or-
tho-
cl a. sc. i

i

In granular
limestone, fre-
quent. In crys-
talline slates. In
many semi-crys-
talline gneisses,
phyllite, sericite
slate. Rarely in
erupt ives, in
grains in dio-
rites, in rods in
andesites and
porphyrys.

All plagio-
clase is char-
acterized by
the polysyn-
thetic twin-
ning. Triclinic
feldspars can
only be dis-
tinguished by
chemical
means or de-
tei mination of
direction of
extinction etc.

Even then
only in rather
large grains.

Name.

Chemical
comp . and
reactions.

Specif.

Grav.

Cleavage.

Usual co77ibi-
fiations Cffo7'-77i
of sections.

Twitis.

Optical deter
77iinants.

Double I'e-
f7'action.

b. Oligo-
clase.

Si O2 =
62-66%.
A little K
(Aba Ahj
Ab. Aiij^.)

2.62-

2.65

(2.63.)

Most per-
fect 1 0,
also i-i as
albite. 0:

i 1-93°

28^ at the
right.

As albite.

Always
polysyn-
thetic, of
the albite
type; also
ofpericlin-
ic type.

Very similar
to albite. In
cleavage
plates II i-i the
axial points
lie farther out
of the field of
view than in
albite. c in-
clined to the
obtuse angle
0: i-i.

As albite.
Extinction
li 0 in-
clined to
angle 0:
i-i +1°
10^; 11 i-i
inclined

2°-4°.

c. Ande-
site.

R A1 Si^
O12, R=
Na2 and
Ca. (Aba
An^ to Ab^
AiiiO

i

2.65

do

As albite.

As albite.

Often with
the albite
and peri
cline» type
combined.
Individu
als twin-
ned 11 i— 1
are again
twinned
according
to Carls
bad type
or in i-i or
0.

Similar to or-
thoclase but
the axial
plane is more
than I f in-
clined to ob-
tuse angle 0:

i-i. Disp.
=p<v.

As above.
Extinction

II 0 inclin-
ed to an-
gle 0: i-i
— 1° ^7^ to
-2° 19"

II i-i— 4°
50^ to 8°

d. Labra-
dorite.

RAl Sia
Oio (Abi
Aiij to Ab^
Ana ) At
tacked by
!HC1.

2.68-

2.70

As ortho -
clase in
i-i often
with a
play of
colors.

Usually in
large grains,
rarely crys-
tals, as ortho-
clase.

In surface j|
i_i, lateral dis-
appearance of
one axis and
signs of lem-
nisci axial
point not vis
ible; 11 0 lat-
eral disap-
pearance of
the other axis,
axial point
also not visi-
ble. pfv.
do

Acute bisec
trix ^^c at
right angles to
2-i. pfv.
Plates 1 0 and
i-i show lat
eral disap-
pearance of
one or other
axis Axial
point on mar-
gin of field.

As ortho-
clase. Ex-
tinction,
in 0 — 4°
30^ to-6°

54"; i-b

— 1 6° 40''
to 21° 12C

e. B)down-
ite.

(A mix-
ture?) Si
O2 = 49-
45% (Aby
I An3_An.)

, More easi-
4y decom-
! posed by
;HC1.

2.70-

2.73

(2.71)

do

do

do

As Lab-
radorite.
Extinction

II 0=-i4.

5° to 20°

1 i-i=-27°
to 32°.

f. Anor-
thite.

[An]

Ca AI2 Si^
Og SiOs

== 45 —
43%. Sol-
uble in
HCl with-
out forma-
tion of gel-
1 atinous
Isilica.

2.73-

(2.75.)

Complete
0 and i-i.
P: M= at
right =
94° 10°.

As albite.

As albi-
bite.

As albite. '
Extinction

110^-36°

to 42° II

i-i— 37° to
43°-

TABLE XV ILL

Colors

ofpolar-

ization.

1 Color

1 and Re-
fraction.

Struclu7'e.

AssociatioJt

hiclusions .

Altei'ation.

Occurrence.

Re-

marks.

As al-
bite.

i

Colorless,
clear or
cloudy,
white to
gray.

In large grains
or crystals oi
I.O. and in
minute slen-
der rods (sec-
tions of thin
plates. Zonary
structure and
arrangement
of inclusions.
Twinning and
concentric ar-
rangement (as
in orthoclase)
both present.

With

quartz, or
thoclase,
horn-
blende,bi-
otite. aug-
ite and ol
ivine.

Fluid (rarely)
and frequent-
[ly glass inclu-
sions in later
eruptives; au-
gite and apa-
tite microlites

Usually unal-
1 tered in later
and cloudy-
fibrous in ear-
• Her eruptives
Change into
epidote
(“saussurite”)
also to musco-
vite as in or-
thoclase and
nearly all pla-
gioclase.

Primary es-
• sential or ac-
cessory in
eruptives.
granite, dior-
ite. diabase,
gabbro, tra-
chyte, ande-
site, also in
basalt, and
crystalline
slates.

As al-
bite.

With sail-
dine, or
thoclase,
augite,
horn-
blende,bi
otite and
quartz.

do

Primary es-
sential in ton-
alite (quartz
diorite), in
andesite, in
particular, and
esites, porph-
yries, syenite,
also in cryst.
slates.

do

As al-
bite.

i

[

do

Usually un-
altered.

do

Hornblende,
olivine, dial-
lage, magne-
tite, titanic
iron. Acicu-
late microlites
are very abun-
dant and lie |
c or the angle
0: i-i, and
brown plates
(ferric oxide
or brookite?)
which have
their long axis
at right angles!
to the micro |
lites, or innu-
merable mi-
nute colorless
or greenish
grains (epi- I
dote?)

In grains and
large crystals
I.O. and mi-
crolites II 0
When twin’d
upon both the
albite and pe-
r feline type a
lattice struc-
ture similar to
microcline ap-
.pears, but the
bands are
more distinct

As orthoclase.
Often into
epidote and
muscovite.

Primary, es-
sential, in nor-
ite, gabbro,
dolerites, es-
pecially also
in dacite, ba-
salts, diorite.

do

Usual-
ly very
vivid.

!

As ortho-
clase.

With di-
allage, hy-
persthene,
olivine,
also with
quartz, au
gite, horn-
blende,
and bio-
tite

do

Primary es-
sential in
eruptives, di-
orite, gabbro,
andesites.

do

1

do

1

do

do !

i

1

i

i

1

j

i

1

With
horn-
blende,au-
gite, bio-
tite, dial-
lage, hy-
persthene

do

but no micro-
lites and
scales.

As lab-
brador-
te.

i

[Colorless,
clear, as
labrador-'
ite.

As labrador-
ite.

!

j

i

1

With lab-
radorite,
augite, hy-
persthe-
nite, oliv-'
ine.

As oligoclase.

Usually unal-
tered, as the
other plagio- <
clase species. 1

1

c

(

Rather rare,
primary es-
sential in
sruptives. In
basaltic rocks
and augite an-
desites, gab-
bro and norite,
in crystalline
>lates,amphib-
alites, gneiss.

!

Distinctions between the various plagioclase species.

The species lettered b-e are, as is well known, isomorphous mixtures of the
two terminal members of the series — albite (ab) and anorthite (an). In physical
and optical, as well as chemical characters, there are perfect transitions, and
oligoclase, andesite, labradorite and bytownite are simply named members of the
series.

As shown by Schuster’s investigations, it is possible to distinguish the plagioclase
species by determining the direction of extinction in cleavage (planes parallel to
O and i-i.

The "above given data of extinction refer to the customary position of the
examined plagioclase, (the upper O surface inclines from left to right, as well
as to the front,) and always to the obtuse angle O. i-i, i. e. the surface i-i lying
to the right. The -|- sign in the case of cleavage plates || O indicates that the
direction of extinction is inclined to the obtuse angle O : i-i in the direction of
the right prismatic angle; in cleavage plates i| i-i that it is inclined as i-i with i-i
the — sign in both cases indicates the opposite direction.

C. Aggregates.

Aggregates are never dark between crossed Nicols because the numerous
minute crystals are irregularly distributed. If the aggregate has a radial fibrous
structure a fixed interferance figure may appear. Very often such aggregates
may only he determined by chemical means.

1. Serpentme (Mgj Si2 H.2 Og aq.) Specif, gr. 2. 5-2. 7. Green, yellow or
brown, to black. Characterized by the mesh structure resulting from decay of
olivine. In other cases the substance consists of large plates which may be
regularly arranged at right angles to each other. It occurs as an independent
rock mass or a decomposition product or pseudomorph after olivine.

2. Viridite. Decomposition products of augites and hornblendes as well as
garnet and biotite. (Delessite, chlorophaite, etc.)

3. Basite. Decomposition product of pyroxene, very similar to serpentine.

4. Chalcedony. A secondary mineral except in quartz sphaerulites.

5. Zeolites. Include natrolite, scolezite, stilbite, de.smite, and chabasite.

6. Carbonates. Aragonite. Decomposing with effervescency in H Cl,
Easily distinguished from calcite by crystal form.

Explanation of Figures.

Fig. I. Distyla ohioensis, sp. n. (p. 54.)

Fig. 2. Diurella tigris, Ehr. (p. 49.) M, maxtax, egg, G. ganglion, s,
sensory tube, spines of lorica, /, intestine, Pv. Pulsating vessel, eye.

Fig. 3a. Ploesoma lenticulare, sp. side view.

Fig. 3b. do. do. ventral view.

ERRATA.

Page 7, line i, instead of preceding, read proceeding,
do 8, do 4, do do anteriorally, read anteriorly,
do 15, Plate I, Fig. 2. instead of L, read f.
do 48, line 7.\, zw/mz/ ampuliformis ampulliformis.
do 59, do I2-, do do Plate i, Fig. Ill readV\d.i% III, Fig. i.

do 60, do 27, do do Asplanchnsea do Asplanchna.

do 61, do 33, do do ampuliformis do ampulliformis.

do 133, do 6, et seq. i-i read i-F.

do 135, do Under monoelinic, instead of i-i and i-i, read i-F in each case.
Table VIII, Apatite, instead of I,i readl.i.

do /A, Olivine do do I=i 19° 2^ 1=130° 2^.

do XI, Hypersthene, under cleavage, instead of conchoidal fracture i-i,
read i-i.

Table APT/. Instead of Tricilnic, Triclinic.

do XVIII. Anorthite; cleavage, instead of \-l read i-i.

/

I NDEX.

A.

Acroperus

Alona quadrangula__

Alona sanguinea

Alonopsis

Anuraea

Anuraea longispina

Asplanchnaea

Asplanchna magnificus

Asplanchna sp

Asplanchna Brightvvelli

B.

Barnes & Co

Bausch & Bomb

Behrens

Bor'cky

Brachionus bakeri

Brachionus intermedins

Brachionus militaris

c.

Canthocamptus

Camptocercus

Chirocephalus holmani

Cladocera :

Clinton Group of Ohio

Coccothraustes

Conochilus

D.

Dinocharis pocillum

Distyla minnesotensis

Distyla ohioensis

Distemma ,

Diurella

38

37

37

38

48, 58
61
60

60

61
61

126

127
130
130

55

56
56

37

37
19

38

63-120

5

44

5^

53

54
^9
49

Diurella insignis 50

Diurella tigris 49

E.

Editorial statement 4

Euchlanis (dilatata'i hippo-

siueros 47

Euchlanis ampulliformis 48

Evening Grosbeak 5“i5

F.

Floscularia ornata 47

Foerste, Aug 25, 63

FOSSILS. —

Acidaspis loi

Acidaspis 100, lOi

Arionellus 114

Arionellus loi, 114

Atrypa 90

Atrypa nodostriata, H 78-90

Atrypa reticularis, Linn., — 7,5

Bathyurus 100, 103

Bellerophon 99

Beilerophon fiscello-striatus,

n. sp 94-99

Bellerophon bilobatus, Sow. 99

Brachiopoda 77, 78

Buchania 99

Buchania exigua, n. sp 94, 99

Calymene 74-109, 110

Calymene Blumenbachii,

Brong ? lOi, 109

Calymene Niagarensis, H.,_ 109

Calymene- 100, 109

Chaetetes 68

Clathrapora Clintonensis H.

&Wh 72,75

Crustacea 100

Cyclonema 94

Cyclonema bilex, Con 76, 94

Cyalora 96

Cyclora alta 94, 96

Cypricardites 93

Cypricardites ferrugineu’xi,

A. and Wh 91, 93

Dalmanites - 1 16

Dalmanites verrucosus, H loi

Dalmanites vigilans loi, 116

Dalmanites Werthneri, n.

sp 68, 76, lOi, 1 16

Eichwaldia 91

Eiclrwaldia reticulata, H_75, 76, 78, 91

Gasteropoda 77, 94

Grammysia 92

Grammysia Caswelli, n. sp_ 91, 92

Holopea 96. 98

Illsenus 73, 76, 104

Illaenus ambignus, n. sp_ 100. loi, 106
Illaenus Daytonensis, H. Sl

Wh 100, loi, 104, 108

Illaenus insignis, H loi, 106

Illaenus Madisonianus, Wh_

74, 100, loi. 106

Lamellibranchiata 77, 91

Leptaena 79

Leptaena prolongata, n. sp_ 78, 7q

Leptaena sericea. Sow 79

Leptaena transversalis, Wahl. 78, 79

Lichas 112

Lichas breviceps i o i , 1 1 2

Merisiella 88

Meristella cylindrica, HalL 88

Meristella Prinstana, Bill 88

Meristella umbonata, Bill 76, 78, 88

Nucula 93

Nucula minima, n. sp 91, 93

Nucleospira pisiformis, H.. 83

Orthis 72, 80, 86

Orthis acuto-plicata 86

Orthis bella-rugosa, Con 86

Orthis biforata, Schlot 80, 81, 82

var. lynx 74, 78, 80, 82

var. acutilriata. 82

Orthis biforata. f. Clintonensis —

f. reversata 76

f. Daytonensis 78; 82

f. reversata 78, 80, 82

Orthis DaytonensL, n. .sp-- 74, 78, 87
Orthis elegantula, Dalm_76, 78, 84, 85
Orthis elegantula, var. parva,

n. var 76, 78, 85

Orthis fausta, n. sp 70. 76, 78, 85

Orthis flabellum. Sow 76, 78,82

Orthis hybrida, Sow 76, 78, 83, 84

Orthis insculpta, H 86

Orthis Nisis, H 78, 86

Orthis pisum, H —

Orthoceras 117

Orthoceras Duseri. H. & Wh. 1 18

Orthoceras inceptum 117

Platyostoma Niagarense. H- 73, 94, 97
Platyostoma Niag. var. trigostoma.
Platyostoma plebium, H — 98

Pleurotomaria 96

Pleurotomaria inexpectans,

H. & Wh 94, 96

Pterinea gi

Pterinea brisa, H 91

Ptychophyllum 75

Raphistoma 95

Raphistoma affinis, n. sp 94,- 95

Raphistoma lenticularis, Em_ 95

Retepora angulata, H 72

Rhinopora 68

Rhynchonella 90

Rhynchonella neglecta, H 78

Rhynchonella scobina,Meek- 76, 78, 90

Strophomena 79

Strophomena rhomboidalis.

Wilck ' 78, 79

Strophostylus 96

Strophostylus cyclostomus, H. 94, 96

Trilobita 77, 100

Triplesia 89

Triplesia Ortoni, Meek 76, 78, 98

Triplesiana, n. sp 78, 89

Trochonema 94

Trochonema nana, n. sp 94

Zygospira

90

PLANTS. —

Zygospira modesta. H

78, 90

Ambirosia artemisiaefolia, L.

31

Fringillidae..

13

Ambrosia trifida, L

31

Furcularia

49

Aristolochia clematitis

34

G.

Aristolochia Sipho, L’Her_

27» 33

Atriplex patula, L

34

Geology

64

Atropa Belladona

29

H.

Barbarea vulgaris. R. Br

31

Brassica nigra, Gray

31

Hesperiphona vespertina

5

Carya alba, Nutt

30

Hesperiphona abeillii

5

Carya amara, Nutt

30 •

Heterognathus

49

Carya microcarpa, Nutt

30

Hussak - 1 21, 123,

i34> 137

Carya olivaeformis, Nutt

30

1.

Carya porcina. Nutt

30

Ilyocryptus agilis

40, 41

Carya sulcata, Nutt

30

Ilocryptus setifer

39

Carya tomeiitosa, Nutt

30

Ilycryptus sordid us

40, 41

Cassia Chamaelicrista, L

32

Ilvocryptus spinifer

40, 41

Cercio Canadensis, L

29

Chelidoneum majus, L

3L 32

L.

Chenopodium album, L

31

Laboratory manipulation

121

Coreopsis tinctoria, Nutt__

34

Leydigia quadrangularis

37

Coreopsis tripteris. L

34

Limnetes gouldii

17

Cornus stolonifera, Miohy

31

T .irlTnlriTiml Inflip

126

Delphinium

27, T.'l

Lithological microscope

127

Delphinium consolida, L

32, 33

Lithological manipulation

121

Dianthera Americana, L

32

M.

Dicentra Cucullaria, DC

30

Fraxinus Americana, L

27, 29

Macrodactylea _

49

Fraxinus sambucifolia, Lam._

29

Mastigocerca

49

Fraxinus viridis, Michx

29

Melicerta ringens

44

Cerardia purpurea L

31

Micro-chemical methods

128

Gleditschia triacanthos, L. _

33

Minerals (see below.)

Gymnocladus Canadensis,

Monocerca

49

Lam .. 21;

26, 30

Monocerca rattus

51

Juglandaceae

25, 27

Monostyla quadridentata_l

53

[uglans cinerea, L

33

Monospilus dispar

3^

Juglans nigra, L

33

Monura

49

juglans regia, L

30

N.

Lactuca

27

Lactuca Canadensis, L

31

Notommata ..

47

Leguminosae

29, 34

0.

Lilium bulbiferum, L

33

Osteology of Hesperiphona

7

Lindera Benzoin, Meisner

33

Lippia Lanceolata, Michx__

32

P.

Liriodendron Tulipifera, L_

30

Paleontology

76

Lonicera Tartarica, L

25, 34

Phyllopoda, Metamorphosis of

16

Loranthaceae

33

Pipilo erythropthalmus

13

Lycopus sinuatus, Ell

31

Lysimachia ciliata, L..

31

Lysimachia nummularia, L_

33

Lythrum alatum, Pursh

32, 33

Medicago

29

Melilotus alba, Lam

34

Menispermum Canadense, L.

30

Mimulus ringens, L

3i

Nesaea verticillata, H. B. K.

31

Oenothera fructicosa,. L

31

Passiflora lutea. L

34

Penthorum sedoides, L

32

Phryma leptostachya, L

31

Ptelea trifoliata. L

29

Ptero-carya Caucasica, KenelL

30

Robina Pseudacacia, L

30

Rubus

30

Ruella ciliosa, Pursh

31

Sambucus Canadensis. L

30

Scrophularia nodosa, L

31

Sisymbrium officinale, Scop.

31

Solanaceae

29, 34

Teucrium Canadense, E

31

Thalictrum dioicum, L 28,

3L 34

Trifolium

34

Ulmus fulva, Michx

35

Verbena stricta, Vent _

31

Verbena urticifolia, L

31

Vitaceae

34

Pleochroism

134

Pleuroxus procurvus

37

Ploesoma lenticulare

57

Polyarthraea

48

Polyarthra platyptera

49

Pterodina patina

59

mine:

Q.

QUARRIES. —

Allen’s

74

Carrollton Pike

70

Centreville

74

Day' on

73

Eaton Pike

66, 70

Fair Flaven

75

Fauver’s

75

Huffman’s

73

Soldiers’ Home

70

Stolz’s

67

Swartzbaugh’s

68

R.

Rattulus

49

Rock sections

121

Rotifers of America .

43^ 62

Rotifer . :

47

s.

Salpina affinis

52

Salpina mucronata

52

Scardium .

49

Squamella bractea

54

Stephanops muticus

54

T.

Table of abbreviations

137

Tables for determination of

rock-forming minerals_

^37-157

Thoulets’ method

123

Triarthra

48

Twinning phenomena

133

u.

Use of polarizing microscope-

131

LS.

A.

Acmite XV
Actinolite XV
Afftrre^ates XIX
Albite XVII
Alamandine garnet II
Analcite III
Anatase V

Numbers refer to cable.

Apatite VIII
Aragonite
Augite XIV
Andalnsite XI
Andesite XVII
Anomite XII
Anorthite XVIII
Anthophyllite X

B.

Basite X
Biotite VIII
Bronzite X
Bytownite XVIII
C.

Calcite VII
Cancrinite VII

Calcedony XIX
Chiastolite XI
Chlorite VIII
Chloritoid XII
Chromite III
Clinochlore XII
Cordierite XI
Corundum VIII
Couseranite V
Chabasite XIX
Cyanite XVII

D.

Delessite XIX
Diaclasite X
Diallage XIV
Dichroite XI
Diopside XIV
Dipyre V
Disthene XVII
Dolomite VII

E.

Elaeolite VII
Enstatite IX
Epidote XVI

F.

Feldspars XVII
Fluorite III

G.

Glaucophane XVI
Garnet II
Graphite I
Gypsum XVI
II.

Helminthite XII
Hauyn (Hauynite) II
Hematite VIII
Hercynite III
Hornblendes XV
Hypersthene X

I.

Ilmen ite=Chromite

L.

Labradorite XVHI
Leucite HI, IV
Liebenerite V H
M.

Magnesite VH
Magnetite I
Mejonite V
Melanite HI
Melilite V
Meroxene XH
Microcline XVII
Micropegmatite H
Muscovite XH
N.

Natrolite XIX
Nepheline VII
Nigrine IV
Nosean 1 1

O.

Oligoclase XVHI
Olivine IX
Omphacite XIV
Opal

Orthocla.se XH
Ottrelite XH

P.

Pennite XH
Perowskite HI
Phlogopite XH
Picotite HI
Pinite HI
Plagioclase XVH
Pleonast HI
Protobasite X
Pyrite I
Pyrope H

Pyrrhotite I.

Q.

Quartz VI

R.

Repidolite
Rubellane XH
Rutile IV

S.

Sagenite IV
Salite XIV
Sanidine XIH
Scapolite V
Sericite XH
Serpentine XIX
Siderite VH
Sillimanite IX
Smaragdite XV
Sodalite'II
Specular iron VIH
Spinel HI
Staurolite IX
Stilbite XIX

T.

Talc XH
Titanite XH
Titanic iron I
Tourmaline VIH
Tremolite XV
Tridymite VI ■

U.

Uralite XVI

V.

Viridite XIX

W.

Wollastonite XV
Z.

Zeolite XIX, VH
Zircon IV
Zoicite XI

The Natural History Department

OF

DENISON UNIVERSITY.

The work in Natural History is distributed as follows:

I. In Biology. The preparation assumed in such as is usually
afforded in high and preparatory schools, viz: An elementary term

in Human Physiology and Hygene and some preparatory work in Bot-
any. In the Sophomore year the winter term is devoted to Compara-
tive and Human Anatomy and Physiology. The genesis of organs
and comparative (vertebrate) morphology is discussed as far as time
permits. The hygenic applications of physiology are briefly presented
but the physiology of the nervous system and comparative Psychology
are relegated to the elective term of the Junior year. An
amount of time equivalent to an hour per week is devoted to dissec-
tion and other laboratory practice.

In the following term elementary Botany is studied. The time
is largely occupied with the study of phenogams and higher crypto-
gams. Field-work and plant-analysis supplemented by some labora-
tory practice in structural Botany accompany the use of the text book.

During the Junior year one term is given to Structural Botany and
the study of the lower groups, including Algae and Fungi.- Apart of
the term is occupied with Plant Physiology. Three-fifths the time is
devoted to the laboratory work. The class construct simple appara-
tus and conduct independently experiments in physiology.

A term in Zoology follows, and is- occupied chiefly with the study
of invertebrates. Begining with the cell and monocellular organism,
types of each class are studied in the laboratory. In this way the de-
velopement of the vertebrate type is traced. The proportion of time
devoted to lecture and laboratory work is as in the previousTerm.

An elective term in Zoology affords opportunity^ for workjn His-
tology and special study in particular lines. It is intended to confine

study very largely to the vertebrate type and an exhaustive study of
one organism or system is advised. The work is supplemented by a
short course in comparative psychology on the basis of Wundt and
Lotze.

Geology and Mineralogy.

In the spring term of the Sophomore year opportunity is offered
scientific students to study mineralogy. The work is largely confined
to the laboratory, and embraces blow- pipe analysis and the elements
of crystallography. Some attention is given to economic mineralogy
but assaying, etc., are considered to belong with the chemical depart-
ment.

The Seniors study Dynamical and Historical Geology in the fall
term using Le Conte’s text book, supplemented by lectures on the sim-
pler facts of structural Geology and extended tours to interesting lo-
calities.

In the winter term a course in Applied and General Geology
varies with the exigencies arising. The course this year embraces the
study of lithology, and the application of geology to the arts. Strati-
fied rocks are studied with reference their macroscopic peculiarities and
economic application. Metamorphic and igneous species are then
studied by means of thin sections and the polarizing miscroscope. At
other times paleontology is substituted.

OUTFIT AND APPARATUS.

For Botany an herbarium (to which additions have been received
from Minnesota during the past year and a large collection is promised
by Mr. Foerste) affords the needed illustrative material. A good set
of compound microscopes with cameras, dissecting apparatus,
staining and other reagents have quite recently been secured.
Aquaria and a collection of conservatory plants will soon be provided,
while the apparatus needed in vegetable physiology will be construct-
ed by the students.

The Zoological laboratory is supplied with approved microtomes,
and hardening, staining and conservative fluids, injecting apparatus, etc.
We at present lack the costly apparatus for physiological investigation
and records but it is hoped that this need may be soon supplied.
Physiology is illustrated by prepared skeletons, casts, microscopic
slides, etc., but much more is .needed. ^Fhe instructor will soon have
ready a large suite of specimens illustrating comparative anatomy.
The cabinet, though small, is rapidly augmenting, having more than
doubled in effectiveness during the year past,

In Geology charts and illustrative material are of a good quality,
but requiring many additions. The supply of type minerals and
rocks has been materially increased. A lithological lathe and polariz-
ing microscope of modern construction as well as over one hundred
typical rock sections have been secured. Apparatus for applying
micro-chemical tests is also supplied.

Although much has been done, there are many wants unsupplied.
The room is much too limited and two additional appartments could be
at once employed. The cabinets in all departments need great addi-
tions to make them adequate for purposes of illustration. To this
end friends are earnestly solicited to send to the professor in charge
specimens of any and all natural objects from various parts of the
state. No animal or stone is so common (if perfect in its way) as to
be useless. Contributions in money will be carefully expended to the
same end in securing exotic specimens.

Directory of Colleges of Ohio, Etc.

ALPHABETICALLi’ ARRANGED.

ADELBERT COLLEGE, OF WESTERN RESERVE
UVIVERSITY.

CLEVELAND, OHIO.

Pres. Rev. Carroll Cutler, D. D.

Open to both sexes on equal terms.

Adjuncts: Medical Department, G. C. E. Weber, LL. D.,
Dean; Western Reserve Academy, Principal, N. B. Hobart, A. M.,
Hudson, O. Green Spring Academy, Principals, P. E. Laner, A. B.
and M. J. Hole, Green Springs, O.

Two courses are provided in the collegiate department, leading to
the degrees of Bachelor of Arts and of Letters respectively, and
special courses with certificates, libraries contain about 12,000 volumes.
The departments of Chemistry and Physics are well supplied with ap-
paratus. The observatory is equipped with a five-inch equatorial and
a three-inch meridian circle. The museum contains well-selected and
increasing geological and other cabinets. Next year begins Sept.
9th, 1886.

BUCHTEL COLLEGE.

AKRON, OHIO.

Pres. Rev. Orello Cone, D. D.

Three courses of study, these are: — The Classical, Philosophical
and Scientific course, leading to the degrees B. A., Ph. B. and B. S.,
respectively. All studies are elective after the first term of Sopho-
more year. The faculty consists of eighteen professors and instruct-
ors. The college was founded by the Ohio Universalist Convention
in 1870. Its outfit embraces an astronomical observatory fully
equipped with in.struments and improved physical and chemical ap-
paratus and a cabinet of Natural History. Those designing to teach
receive the benefit of regular instruction in methods of teaching.
Year begins on the first Tuesday in September.

DENISON UNIVERSITY,

GRANVILLE, OHIO.

Pres. Alfred Owen, D. I).

Denison University comprises both a collegiate and a preparatory
department. In the college department are three courses leading to
the following degrees, A. B., B. Ph., B. S., with preparatory courses
corresponding.

The college has eleven Professors and instructors, well equipped
Chemical, Physical and Biological laboratories and a large and excel-
lent library. The productive endowment exceeds $300,000. In-
struction is thorough and expenses low. Those who cannot take a
full course are permitted to take special studies when they can do so
with profit to themselves and without injury to others. School year
from Sept. 9, 1885, to June 24, 1886. The next school year com-
mences Sept. 6, 1886.

HIRAM COLLEGE.

HIRAM, PORTAGE CO., OHIO.

Pres. Geo. LI. Laughlin, A. M.

Four courses, comparing favorably with best colleges in Ohio, viz: —
Classical, Philosophical, Scientific, and Biblical. Faculty of twelve
competent instructors. Total number of students 205, of whom 99
are ladies. Ample provision for instruction in music and drawing, as
well as in the elementary branches. The outfit in science includes val-
uable collections of Western ores and fossils from Dr. F. V. Hayden
and contributions from the Smithsonian Institute. Valuable additions
have been made to the philosophical apparatus of the college. Tui-
tion and board at reasonable rates. First term opened Sept, i, 1885,
and the year closes Thursday, June 17, 1886.

OHIO STATE UNIVERSITY.

COLUMBUS, O.

President, W. H. Scott.

The University has twenty-five professors and instructors.
It offers eight courses of study leading to degrees as follows: — B. A.,
B. Ph., B. Sc., C. E., Mining Eng., Mech. Eng., B. Ag., and V. S.;
preparatory, course, a short course of two years in agriculture, and a
course in pharmacy.

If possessess eleven well-equipped laboratories, — Physical, mechani-
cal, chemical, metallurgical, agricultural-chemical, botanical, and physi-
ological, and the most extensive and valuable museum of Ohio geology.

Its land, buildings, equipment and endowment are worth more
than one million, one hundred thousand dollars.

OHIO UNIVERSITY.

ATHENS, OHIO.

Chas. W. Super, President.

Classical, Philosophical, Preparatory and Normal departments.
Instruction is chiefly given by the regular professors who are more or
less specialists in their departments. Much new apparatus has recent-
ly been purchased to illustrate Physics and Chemistry. A chemical
laboratory with gas and water has been provided. Young ladies are
admitted to all departments upon the same terms with young men.
One student from each county is entitled to a free scholarship, the con-
ferring of which is in the hands of the county auditor and commissioners.
Fall term begins Sept. 7, 1886, spring term begins Mar. 30, 1886.

OHIO WESLEYAN UNIVERSITY.

DELAWARE, OHIO.

C. H. Payne, D. D., LL. D., Pres.

Offers to both sexes, at surprisingly small expense, unsurpassed
advantages for a full collegiate course or for special studies. Collegi-
ate, Preparatory, Normal, Commercial, and Art Departments. First-
class Conservatory of Music. Elegant home for ladies, with teachers.
Necessary expenses per term $50 or less. As at present constituted,
the museum embraces four distinct cabinets :

I. William Wood Cabinet of Casts of Fossils. 2. Mann Cab-
inet of Palaeontology. 3. Prescott Cabinet of Biology, and 4. Mer-
rick-Trimble Cabinet of Mineralogy.

The library embraces 13,786 volumes.

'^he study of the Bible is persued in some form by every student
during his entire course.

BETHANY COLLEGE.

BROOKE CO., W. VA.

Pres. W. K. Pendleton, LL. D.

PYur courses, leading to appropriate degrees, viz: — Classical, Sci-
entific, Ministerial and Ladies’ courses ; also special Professional Courses
in Engineering, Practical Physics and Chemistry, with ample training
in field-work and laboratory with use of instruments and apparatus.
Now in 45th session. Alumni number 640. Expenses are reduced
to a minimum, and every facility for economy in time and money is
afforded. All classes open to both sexes. Year begins the last
Monday of September, closing the third Thursday of June. For cata-
logueaddress Prof. W. H. Woolery.

LABORATORY SUPPLIES.

In order to facilitate the study of Natural History in Ohio the de-
partment has arranged to furnish such laboratory supplies as may be
accessable in convenient sets adapted to college or high school or in-
dividual use. The business will be conducted by Mr. C. J. Herrick,
while the preparation of the material will be under the immediate direc-
tion of the department.

No. I. Lithological suite of 25 hand-samples of type rocks

wdth accompanying thin sections and a lithological microscope
manufactured expressly for the department, also apparatus for
making thin sections by hand, _ _ _ _ $-7^ 00

Lithological lathe (additional) - - - - - 50 00

No. 2. Suite of stratified fvcks, 25 samples, accompanied by sections
of the most important building stones and fossils typical of each
rock and one of Bausch & Lombs’ model microscopes, com-
plete, ‘1^65 00

Sections of rocks or fossils will be made on application at a low
rate. Other laboratory supplies will be secured and kept on hand as
opportunity affords. Address C. J. Herrick, Granville, O.

THE. TWENTIETH YEAR !

THE AMERICAN NATURALIST;

A Popular Illustrated Magazine of N atural History and Travel.

ANNOUNCEMENT FOR i8S6. ' VOLUME XX.

This journal of popular Natural Science is published by Messrs. McCalla &
Stayely, Philadelphia. Pa., under the editorial management of Dr. A. S. Pack-
ard, and Prof. E D. CoPE, with the assistance of eminent men of science. The
typographical dress and illustrations which have heretofore given character to this
magazine will be sustained, and it will be of a thoroughly popular nature, so as to
interest the general reader as well as the young naturalist. It will continue to be
a journal of science-education and for the use of science- teachers

The eighteenth and nineteenth volumes were double the size of the earlier
volumes ; and for variety, interest and freshness of scientific news, it is claimed
that the N^atu racist is without a rival.

Each number of the Naturalist contains carefully written original articles
on various scientific subjects, and, in addition, twelve departments — Recent Litera-
ture, Geography and Travels, Geology and Paleontology. Mineralogy , Botany, Ento-
mology, Zoology, Embryology, Physiology, Psychology, Anthropology , and Microscopy .
The department of Botany is edited by Prof. C. E. Bessy, that of Microscopy is
edited by Prof. C. O Wi-iitman, that of Mineralogy is edited by Dr Geo. H.
Williams, and that of Physiology by Prof. Henry Sewell, while the depart-
ment of Geography and Travels is edited by W. N. LocKiNGTON. Prof. Otis T.
Mason will continue his monthly summaries of Anthropological News, and will
edit the department of Anthropology We added this year a department of Em-
bryology, under one ol our ablest investigators, Mr. Jno. A Ryder, of the Smith-
sonian Institution. Arrangements have been made to report the Proceedings of
Scientific Societies with promptness. Particular attention will be given to micro-
scopical and historical discoveries, methods of microscopical research, new instru-
ments, methods of cutting and staining sections, etc. The series of illustrated
monographs on North American fossil vertebrates, by Prof- Cope, witl be continued.

The attention of publishers and teachers is called to the critical notices of
standard scientific books, to which especial attention has been given the past year,
and will be given during the ensuing year.

Original articles or notices by over one hundred of our leading naturalists have
appeared in the volumes for i88i, 1882, 1S83, 1884 and 1885, among whom are
the following: —

Dr. C. C. Abbott,

Prof. J. C. Arthur,

Mr. E. A. Barber,

Prof. W. J. Beal,

Prof. W. K. Brooks,

Mr. Edward Burgess,

Hon. J. D. Caton,

Dr. Elliott Cones,

Dr. W. H. Dali,

Prof. Walter Faxon,

Prof. S. A. Forbes,

Mr. J. W. Fewkes,

Prof. Archibald Geikie,

Mr. Henry Gillman,

Dr. Carl F. Gissler,

Mr. Edward Lee Greene,

Prof. F. V. Hayden,

Subscription Price,

Rev. E. J. Hill,

Mr. E W. Claypole,
Prof. T. Sterry'Hunt,
Prof. A. Hyatt,

Ernest Ingersoll,

Prof. 1). S Jordan,

Mr. J. S. Kingsley,

Prof. Samuel Lockwood,
Prof. Leo Lesquereux,
Prof. G. Macloskie,

Dr. C. Hart Merriam,
Mr. Charles Morris,

Rev. Henry C. McCook.
Prof. C. Sedgwick Minot
Prof E. S. Morse,

Prof. A N Prentiss,

Dr. D. W. Prentiss,

Mr. Richard Rathbun,

Dr. Charles Ran,

Mr. J. A. Ryder.

Dr. R. W. Shufeldt,

Dr. T. H. Streets.

Prof S. I. Smith,

Prof. V. M. Spalding,

J. F. Whiteaves,

Prof. F. H. Snow,

Dr. R. E. C. Stearns,
Prof. Cyrus Thomas,

Mrs. Mary Treat,

Mr. Wm. Trelease,

Dr. M. PT Wadsworth,
Dr. R. H. Ward,

Prof. C. A. White,

Prof. R. Ramsay Wright.

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or New York, or registered letter, to M'SCALLA Bs

237«9 Sook StKst, PMladdpkia, Pa.

BULLETIN

OF THE

SCIENTIFIC LABORATORIES

OF

DENISON UNIVERSITY,

EDITED BY

i

yJ

C. L. HERRICK, Dep’t. of Geol. and Nat. History,

AND

A. D. COLE, Department of Chemistry and Physics.

VOL. II, PART 1.

GRANVILLE, OHIO, APRIL, 1887.

i-

Downs & Kussmaul,
Printers,
Granville, Ohio.

EDITORIAL STATEMENT.

We note with pleasure the growing interest in the work represent-
ed by this publication and the greatly increased facilities now afforded
for advanced work. The present volume, although the work of more
hands than that of last year, does not adequately indicate the scope which
the publication is expected to cover, because a disproportionate amount
of space has been given to geological discussions, the results of which it
is hoped to immediately employ. Several articles again crowded out,
as well as the promised instalments of continued papers, will appear
in the next issue The department of Chemistry and Physics may be
expected to contribute its full quota to the interest of the publication.

We need hardly remind the professional naturalist that other con-
siderations are subordinated to the educational, and the papers are
strictly, as they profess to be, outgrowths of class work and laboratory
exercise. If, notwithstanding, results of a certain degree of interest
as contributions to science develop, it will not be regretted by us. It
ought not to be necessary to say that the material is in each case origi-
nal, and collected, as well as elaborated, by those to whom it is accred-
ited.

The uniform kindness of the learned societies from which ex-
changes have been solicited, calls for grateful recognition on our part
A full acknowledgement will be found in the next issue.

To kind friends who have contributed apparatus and specimens
we can only speak general indebtedness. A freezing microtome man-
ufactured and donated by Dr. Jacobs, of Newark, should be appre-
ciatively mentioned, as also a valuable collection of eggs presented
by Mr. G. D. Pearce. Finally, it should be said that the means for
sustaining this publication have been secured solely by voluntary con-

tribution, almost the entire amount being donated by Hon. E. J.
Barney and Hon. J. B. Thresher, of Dayton, and another person too
immediately interested to care to allow his name to appear. The re-
sults of the laboratory class on lake Superior, during the last summer,
were so satisfactory that it is hoped to repeat the experiment on a
larger scale during the summer of 1888. The editors will be glad to
correspond with teachers and others desiring such opportunities as
would be afforded by laboratory work at a station located upon the
Gulf of Mexico. The work will depend somewhat on the desires of
those participating, but will consist chiefly in lectures on biology,
chemistry, physics, and geology, and laboratory study in these branch-
es, as well as detailed investigation of the peculiar fauna of the Gulf.
The co-operation of eminent southern naturalists is assured, and the
imperfectly known crystalline rocks of the South will afford a fine
field for the lithologist, as the proposed scheme involves a short tour
in the mountains of Alabama. The facilities of the college laborato-
ries will be placed at the disposal of the workers so far as may be prac-
ticable and all obtainable aids will be secured.

A Sketch of the Geological

HISTORY OF LICKING COUNTY,

Accompanying an Illustrated Catalogue of Carboniferous Fossils
FROM Flint Ridge, Ohio.

Every acr^ of our earth’s surface is marked with tracery which, if
patiently studied and correctly interpreted, will supply pages in the
history of creation. The mind which has ceased to be interested by
the record thus preserved or which inclines to ridicule the youthful
enthusiasm which sees in all natural phenomena manifestations of Di-
vine intelligence, must be far forward in its differentiation (or rather
indifferent-ization) toward the Nirvana of blase^ modern scientists.

We believe that there is vast gain every way in supplementing the
natural curiosity which furnishes the earliest incentive to investigation
by maturer faith in immanent Divinity in nature. Still more useful
is it if one feels that the problems afforded by the earthy records are
God’s gifts to us with the intent that we should learn to know his will
concerning the earth as well as ourselves.

This paper is intended to outline briefly those facts in the geologi-
cal history which lie easily within the reach of any one living in this
county, and to afford the means of studying intelligently the portion
of the geological column lying exposed in this part of Ohio. In as
much, however, as the column is an integer, the investigation of one
part is of importance in the study of the rest.

Far too little has as yet been done in the careful and systematic
study of limited fields. We need in geology more than elaborate gen-
eralizations on insufficient data, carefully elaborated pictures of limited
areas and the succession of life traceable in closely related strata. We
believe it possible to become almost as familiar with the fauna and
flora of Licking county, for instance, during the time when coal depos-
its were forming as we are with its present animals and plants. The
question whether the earth has been repeopled at the opening of each

6

BULLETIN OF THE LABORATORIES

era, as claimed by some, or gradually reached its present condition by
progressive development and continuous differentiation, is most likely
to be settled by such detailed study of superposed strata. The work
represented by the notes here given has been the recreation of spare
moments during less than a year, ’but has been sufficient to indicate an
almost exhaustless mine of interesting information. It is hoped that
the study may be pursued much further. The accumulation of mate-
rial has been greatly facilitated by the co-operation of the class in lith-
ology of 1886, some members of which have continued to assist in the
necessary collecting and field-work. Mr. Foerste, of ’87, has also ren-
dered efficient aid in collecting and otherwise.

In as much as the study was carried on independently of the pub-
lished reports it is gratifying to observe the substantial accord of our
results with those of the Geological Survey, so far as the latter ex-
tend. The examination was restricted to a band some miles in width,
extending from Alexandria to Brownsville, with the view of perfecting
a geological section across the line of contact between the coal meas-
ures and the sub-carboniferous formations, which alone are here repre-
sented. Our plan has been to study the various quarries and natural
exposures, gathering such information as may be furnished by fossils
or stratigraphy, then proceeding to parallelize as far as possible the
strata which are recognizable. It is surprising how many hints a bar-
ren looking heap of rock may often furnish. The dip of strata is often
only obtainable by the use of a transit as it varies little from -the hori-
zontal. As we pass from horizon to horizon the imagination sees broad
sandy shoals, marked by ripples, and here and there exposing to view
bivalves of unfamiliar form, or detached valves of brachiopods. Again
a shallow lagoon, with a muddy bottom supporting a luxuriant vegeta-
tion of Spirophyton sea-weeds, whose broad leaves floated about like
the pond-weeds of to-day. Among these darted the trilobites, spring-
ing backward by a quick stroke of the tail, or lazily floating near the
surface, or crawling along the under surfaces of their leafy retreats.
In clearer spots the sea-lily spread its graceful but direful petals while
an occasional horny shielded flsh flashed by in pursuit of slow-swim-
ming gasteropods. Here one reads proof of a stormy promontory,
where the waves ravened pitilessly about the abutting cliffs, and scat-
tered the eroded material in bars and banks within sheltering coves, or
distributed it by currents more equally over a wide area. Such was
the condition of Granville and the adjacent townships before it was

OF DENISON UNIVERSITY. 7

r^-'ised forever beyond the creative touch of the ocean. The Waverly",
group of rocks is the result of the quiet but constant efforts of our
most modern sea. Farther east, however, the sea still continued, but
cut off from direct communication with the westerp ocean and only
now and then keeping up the union at the south. The townships of
Madison and Hopewell were covered by shallow lagoons of salt water.
It was now a 'period of quiet. The gradual formation of a ridge of
considerable width, along the axis, extending from Cincinnati to To-
edo, had cut off the “sou-western,” which had stunted vegetation,
land along the borders of the steaming lagoons a dense forest of ferns
and succulent vegetation of unfamiliar kinds sprang' up. The lepido-
dendrids, whose trunks had occasionally been preserved in qhe sand-
bars of the VVaverly sea, gave place to a more dense growth, , which
literally buried itself under its own profusion and the decaying boughs
were soon submerged by the variable, though shallow waters. There
were, however, constantly recurring periods when the ocean asserted
its ascendency; local or general depressions were followed by inva-
sions of deep arms of the sea, which eroded the distant granite or
nearer sand hills and covered all evidences of forest luxuriance with
sand. The animals which swarmed in the shallow lagoons were such
as are found everywhere in the coal measures and the accompanying
plates illustrate the most important species.

The above history is recorded in alternating layers of shale, coal,
and white sandstone. In the following diagram the sequence of strata
is illustrated, while the sections of Fig. 2 show the chief observed ex-
posures and their relations, as further indicated upon the geological
map.

(The section represented in Figure i, is, in general, east and
west, but there is also introduced a partial section from Madison town-
ship, which is nearly north and south, exhibiting a greater dip, proba-
bly of a local nature, as above indicated. The vertical scale is greatly
exaggerated — 50 feet vertical, equalling one mile horizontal.)

I

BULLETIN OF THE LABORATORIES

Fig. I. SECTION FROM MOOT’S RUN TO FLINT RIDGE, LICKING CO., OHIO.

There is nothing to indicate any great disturbance in position in
the strata since their deposition. Although there is no obvious uncon-
formity between any of the strata exposed, yet the fact that so many
•of them are shore deposits and the fact that farther south and east
Tands of limestone are interpolated, indicates that here and there there
must have been intervals of considerable duration when the process
-of accumulation was interrupted and the days ran round unrecorded.
Any attempt to estimate the time represented must include ample al-
lowance for such breaks in the continuity of the series. Within the
limits of our study about 400 feet in vertical thickness can be assumed,
of which 200 feet consists of the coal measure rocks, and the remain-
der of shales and freestones of sub-carboniferous age. It is probable
that 100 feet should be added below the rocks exposed in this part of
the county to touch the dividing line between the Devonian and car-
boniferous. We have then some 500 feet of material, representing at
least, say 500,000 years, without allowance for the intervals.

Much of the material, undoubtedly, accumulated much more rap-
idly than a foot a century; while the shales and coals no doubt repre-
sent periods of slower deposition. Highly carbonated waters and at-
mosphere no doubt facilitated subaerial erosion, while the profusion of
vegetation must have greatly increased the deposit of organic matter.

OF DENISON UNIVERSITY.

9

Altogether, it would seem that modern measures as applied to calcula-
tions in the Paleozoic, are likely to be too long rather than too shorb
Here the question naturally arises, what is the source of all the mate-
rial thus accumulated, especially the quartz. Most of the white sand-
stones of the coal measures are highly micaceous and in places the
loose sandstone has a schistose character, due to the presence of large
amounts of light colore.d mica. Such deposits can be most readily ex-
plained by supposing them more or less directly derived from granite-
rocks, which were first kaolinized, the aluminous or fedspathic ingredi-
ents being separated and floated to a distance, there producing the
shales, while the sand is accumulated near the shore line. The mica
is partly separated, but is always found in connection with arenaceous,
deposits. But how is it that such large deposits of sand are found at so
great a distance from granitic ranges ? To this it might be suggested
that many spurs of the Archean continent had remained even near
this area and that the material was thus derived directly. Such spurs-
would, however, be very likely to leave other evidences of their exist-
ence. It might be, on the other hand, that during the preceding (De-
vonian) age, sandstones had been accumulated, which now fell a prey
to encroaching and receding seas. But in such a case we might hope
to find fragments of the fossils of the Devonian among carboniferous,
deposits or in other ways receive information of the appropriation,,
much as the old parchments used for church missials have been forced
to reveal the more ancient heathen lore inscribed beneath. Aside
from the negative evidence hinted at, we have the fact that there are
here and there conglomerates containing quartz-fragments which must;
in all probability, have been derived from veins such as are found in
igneous rocks, A third explanation is that the highlands on the east;
and north really supplied the materials and that they were floated and
rolled to their present positions by tidal and wave action. This theory
receives incidental confirmation in several ways.* We find the heavier
materials collected more considerably to the east, even in as narrow^
an area as our own. Bands of Waverly rock, which at Granville con-
sist of freestone, become conglomeritic east of Newark. Northeast of
Clay Lick there seems to have been a promontory or low spit during
the early part of the Waverly epoch. Here accumulated quantities of
sand and conglomerate, while to the south and west layers of shale and
freestone were formed at the same horizon. Then, as now, the dip was
southwest at this point, and in the more protected reach of shore to the

lO BULLETIN OF THE LABORATORIES

west, there gathered at intervals great floating beds or tangles of sea-
weeds. Currents setting from the northeast, bearing freight of sand
and gravel, would naturally deposit all but the lighter .in making this
point, and in the slower eddies beyond drop the clays we really find.

Now it remains to notice that there was evidently a considerable
interval between the fossiliferous beds of the upper Waverly and the
fossil bearing shales of the coal measures — a far greater interval than
is represented by the 170-180 feet intervening. An interval of 100
feet between the shale at Flint Ridge and the silicious limestone seems
to have produced no marked change in fauna, many identical species
Taeing found, while very fewYorms pass from the Waverly into the coal
measures. This might be partially explained by the changed condi-
tions, but that this is insufficient is indicated by the fact that Waverly
freestones contain many species identical with limestones of the same
borizon (Spergen Hill) in Indiana. However, it may be in part ex-
plained by supposing that the waters during the Waverly epoch were
connected with the sea at the west, while during the coal measures
period the sea was part of a southeastern basin, which in the meantime
had become independent. Nevertheless, we have evidence of a pe-
riod left unrepresented in Licking county, but which was employed
farther south in the formation of sub-carboniferous limestones ’( Max-
ville.)

In order to determine the exact relation between the strata men-
tioned it will be necessary to carefully study and compare all the re-
mains preserved, as well as to carry stratigraphical research beyond the
limits assigned. We will examine, therefore, first of all the fossils
found in a thin layer of black shale immediately overlying the coal at
Flint Ridge and lying about 100 feet below the summit of the ridge.
This stratum appears, upon the top of Bald Hill, near Newark, with
identical fossils and lithological character. It is here not supported by
■coal, but lies 100 feet above the lowest coal horizon in the county
(about 73 feet only above the Waverly). This shale also appears to-
ward Brownsville, wherever its horizon is reached. This is undoubt-
edly coal measure rock and its fossils are those found in the coal meas-
ures of West Virginia, Illinois, Missouri, and the far West. After
enumerating these, comparisons may be instituted with the Waverly
and sub-carboniferous limestone as welhas the silicious limestone above.
This narrow band of shale is one of the most highly fossiliferous strata
known, though the number of species is not relatively so great.

OF DENISON UNIVERSITY.

1 1

Should there be found errors of identification, as would be nat-
ural where it has frequently been impossible to obtain reliable exam-
ples of related forms, and in spite of obvious incompleteness, it is
hoped that, in as much as most of the* forms described are figured, this
catalogue may serve a good purpose in several ways.

The Surface Geology of the southeastern part of Licking county,
does not present any very striking points, but it may be interesting to
notice a few of the salient features. The drainage is toward the south-
east, the tributaries of the Licking river, constituting almost the only
streams, except in Bowling Green township. The only large body of
water is the reservoir in Union and Licking townships.

Granville township furnishes numerous exposures of the Waverly
rock, which here may be separated into an upper massive portion fur-
nishing available freestone for foundations and construction below the
water table and for coarse masonry, and the lowest shaly portion which
is here and there interrupted by beds of freestone. The quarries are
all in the hill tops and may be found in many parts of the township,
everywhere, in fact, where the elevation is great enough. But few are
worked more than needed for local consumption, but in the vicinity of
Granville, especially in the hills lying north of the village, are several
which are considerably developed. The best exposure in the township
is midway between Granville and Newark and is formed by the ero-
sion of Raccoon creek. The section at this place is atypical one and
exposes all rocks found in the township, except a few feet above.
About 150 feet is therefore the approximate vertical measure for the
township. The upper courses are in places very fossiliferous, Creni-
pecten Winchelli being a characteristic fossil. Below it is a layer of
shale characterized by the plant Spirophytbn, and below this an 18-inch
band of conglomerate. A few feet below the conglomerate is a dark
shale, affording many lamellibranchs, Allorisma hannibalensis being
abundant. The free-stone below is apt to be full of a species of Cam-
erophoria and many other fossils. The lower shales are usually barren of
other fossils than the stems of fucoids. At Spring Valley, a beautiful
dell a half mile southwest of Granville, a good exposure of the shale
may be seen which is, however, much surpassed at Moot’s Run, nearer
to Alexandria. Union township lies almost wholly below the free
stone, though several exposures of the .shale may be found along the
streams. This shale is in many places highly concretionary, the nodu-
les often containing plant or animal remains. At Moot’s run, some

12

BULLETIN OF THE LABORATORIES

interesting Producti have been found imbedded in these concretions.
Northeast of Granville is a very rough section of the county and here
the conglomerate is more highly developed than elsewhere, and is often
highly fossiliferous, Chonetes illinoisensis, Spirifer carter!, and two
other species, as well as large specimens of Hemipronites being the
characteristic fossils. The highest hills in this vicinity are perhaps 150
feet above the altitude of the conglomerate, at the “dug way,” and may-
be near the line of juncture with the coal-measure sandstone or, in-
deed, may contain a few feet of that rock, though only surface frag-
ments of such a rock have been seen. The thickness of the conglom-
erate or coarse Waverly sandstone is estimated at twenty feet and grad-
uates insensibly into the olive free-stone, as well shown a half mile
northeast of the “ dug way,” 'half way from Granville to Newark.
The free- stone extends in these hills to some 120 feet above their bases,
(or perhaps 60-80 feet above the" 18-inch layer of conglomerate, this
being a mere estimate). The dip is here very slight, probably south-
east.

Hebron Hill, south of Granville, is 106 feet above the B. & O.
track, south of it. South of Newark, along the right bank of South
Fork of Licking, are many exposures of the Waverly rock. The
abutment of the bridge crossing this stream, west of Mechanicsburg,
is 170 feet lower than the top of Hebron Hill and about 60 feet below
the B. & O. track, as indicated. The hills east of the bridge rise, 180
feet and do not reach the coal-measure sandstone. The village of
Mechanicsburg is 150 feet above the abutments, but a few rods east,
at the Licking township line, are hills over 200 feet high, with thirty
to forty feet of the characteristic white sandstone and conglomerate.
It is here massive and might be quarried with ease. A few rods north-
east is a high hill, 300 feet above the bridge, where there seemed to
be about 115 feet of coal-measure rock, part of which is a ferrugine-
ous shale, and extends far above the horizon of the Bald Hill coal.
Indeed, some indications of its presence could be detected. The sum-
mit of this hill is some 60 feet higher than the horizon of Bald Hill
coal and another hill east of Bald Hill rises to a considerably greater
height, though not to the horizon of the Flint Ridge shale, as does
Bald Hill, 100 feet above the coal. The reservoir lies in a depressed
region in Union and Licking townships, but is bounded on the east by
low hills. A trip through this region revealed the presence of Waverly
shales and freestone, with characteristic fossils. A mile eastward, 45

OF DENISON UNIVERSITY.

13

feet above the T. & O. C. R. R. track at the reservoir, by combining
various exposures a thickness for the Waverly of over 100 feet at least
can be made out. Thornville is about 180 feet higher than the rail-
road, and the Waverly shales west of Amsterdam are ten or twenty
feet higher. A range of hills half a mile to the south of the National
Road, rise to 280 feet and expose at least 85 feet of coal-measure sand-
stone and conglomerate, here of a white color and full of Lepidoden-
dron stems and other plants. The base of the sandstone is marked
by a line of springs. It is not now possible to compare these eleva-
tions with those farther north, but evidently the relations are precisely
the same. Although a sub-carboniferous limestone is marked on the map
published by the Ohio Geological Survey, no indications of its existence
were seen in Licking county. On the other hand, the Waverly seems
to extend to the base of the coal-measures exactly as elsewhere.

Passing east from Newark many exposures of the Waverly are
found along Licking river, but the most characteristic exposure is in a
large quarry (the largest in the country), in the southeastern corner of
Newark township. It is possible to trace the whole section from Lick-
ing river to the top of Bald Hill, in the southwest corner of Madison.
The results of our study are embodied in the section accompanying.

14

BULLETIN OF THE LABORATORIES

Fig. 2. GROUPED SECTIONS FROM GRANVILLE TO NEWTON.

Franklin and Hopewell townships are very rough and are inter,
sected in^ every direction by valleys. Flint Ridge, the highest por_
tion of the county, furnishes the best continuous section of the coal-
measures. In the southeastern part of Madison township are several
hills which reach within 200 feet of the top of Flint Ridge, i. e. , to
beyond the base of the coal-measures sandstone. In the northeastern
part of Franklin township are several hills exposing various parts of
the coal-measure series which seems to dip rather strongly to the south.
The coal at Flint Ridge occupies a small local basin and cannot be ex-

OF DENISON UNIVERSITY.

15

pected to prove continuous. It seems to lie some 160 feet above the
Waverly. The highest hill in the county, so far seen, lies in Hopewell,
a mile or more south of this mine, and its summit is 135 feet above
the coal. The upper 30 feet or more is composed of the flinty lime-
stone which caps the ridge. This limestone contains many impressions
of foramifera (Fusulina cylindrica), and but few fossils, among which
are Chonetes mesoloba, Productus longispinus, Pernopecten n. sp. ,
Euomphalus sp. , Productus muricatus, P. nebrascensis, and bryozoans.
This hill is 250 feet above the National Road, directly south. This
road is mended with the carboniferous shale of the horizon of the Flint
Ridge coal. Near Brownsville the sub-carboniferous limestone is said
to appear, but we have not been able to find it, and it seems impossi-
ble that so low a horizon could be reached.

It remains to take a hasty view of the region about Clay Lick
Station, in Hanover township. Here in the middle of Hanover is a
great development of the conglomeratic phase of the Waverly. One
half mile east of Clay Lick there is a nearly continuous exposure of
about 100 feet of alternating conglomerate and coarse sandstone of
prevailingly red color. West of Clay Lick there is a considerable, dip
to the west or southwest. The dip is about seven feet to the hundred.
At a distance of a mile south or northwest the exposure gives a dip of
about 3.6 feet in the-hundred to the northwest. These may be simply
local flextures. It is altogether probable that a spit or bar extended
into the sea northeast of Clay Lick and there great quantities of sand
and gravel were accumulated, while the clayey deposits to the south
and west were longer under the sea and sank somewhat under the
weight of the massive deposits south of them. In the creek bed at
the last mentioned exposure, a mile south of Clay Lick, is nearly a
hundred feet of continuously exposed Waverly, showing none of the
conglomeratic character found east of Clay Lick.

In-order to define as nearly as possible the relations between the
formations in Licking and adjoining counties, a histy excursion was
made into Muskingum county, with the results compendiously exhib-
ited in the sections of Fig. 2. The baroinetic readings were interfered
with by atmospheric changes in passing from Mt. Perry to Brownsville,
so that the connection is not complete, but it is believed that the rela-
tions are relatively correct. Near Newton is a good exposure of over
200 feet, which is shown at No. I. The Maxville limestone is near
the water and continues near the surface of the stream nearly to Mt.

1 6 BULLETIN OF THE LABORATORIES

Perry. The dip from Mt. Perry to Newton appears to be not less
than 250 feet, with no noticeable change in the relative thickness of
the exposed strata. The whole distance southeast represented by the
grouped sections, is about 30 miles. The dip southeast accomplished
in this distance is roughly estimated at from 300 to 350 feet, or some-
thing over ten feet to the mile ; but the dip is much more abrupt after
passing about six to eight miles east of Granville. It would seem from
observations so far obtained that there is every where a rather abrupt
decline along a line a short but variable distance from the edge of the
coal field, so that the sub-carboniferous with a portion of the coal-
measures extends outward in the form of a flat rim to the more con-
cave central basin. In some places this line is almost of the nature of
a fault and causes some obscurity. This line crosses the Licking river
a mile or so east of Clay Lick.

In the next paper we shall be able to make more detailed com-
parisons of the faunae represented. Enough is now known to assure
us that many species have continued from the beginning to the end of
this period. In other cases the coal-measures contain forms which
might be considered the somewhat modified descendants of Waverly
species. Nevertheless there are many, perhaps a majority of forms
which do not exhibit a traceable connection with the Waverly or lower
horizons. How much of this disparity is to be explained by the
changed conditions of life — how much by the fact that the connection
was with a different sea basin, and how much these categories leave
unexplained, bids fair to prove a perplexing question. Such problems
as these demand careful scrutiny and, if possible, adequate treatment.

CRUSTACEA.

Trilobita.

Only one species of trilobite has been encountered and this is
fully described in connection with the discussion of Carboniferous tril-
obites upon a later page of this issue.

The only other remains suggesting crustacean affinities is the cu-
rious valve or plate, figure 21, Plate 1. In some respects this resem-
bles the valve of an Ostracode crustacean, with a very thick shell.

OF DENISON UNIVERSITY.

17

MOLLUSCA.

Cephalopoda.

Genus Ortho c eras.

Orthoceras cribrosuin, Geinitz. (?)

(Plate V, Fig. 2.)

There is but one species of Orthoceras at all abundant at Flint
Ridge, and this is invariably more or less crushed. A smaller species
like O. rushensis, has been doubtfully identified. An average exam-
ple of our species is from three to four inches in total length, with a
rather gradual expansion. About a fourth or fifth part of the shell be-
low is without visible septa and is more rapidly expanded than the re-
mainder, which is apparently cylindrical, having moderately concave
septa, separated by intervals of about four and one-half into the width
of the shell. The siphuncle is apparently nearly central (?) The shell
is very thin and the epidermis apparently unornamented or granular.
The removal of the epidermis reveals a nodose line near one side, the
nature of which has not as yet been determined (Cf.- O. duseri of
Lower Silurian.)

It is by no means certain that the identification is correct. Geinitz
laid stress upon the pitted nature of the shell, though his figure shows
the epidermis to have been exfoliated.

JV’atilus sp.

(Plate II, Fig. 17.)

Fragments of what appears to be a Nautilus allied to N. forbesi-
rnus, McChesney, are not rare, but none of them indicate the shell to
have been septate. Awaiting additional material these are inferred to
be identical with N. decoratus of Cox, identified with the above.

GASTEROPODA.

Genus Bellerophon.

Bellerophon percarinatus ^ Conrad.

(Plate II, Fig. 14.)

Shell subglobose ; laterally expanded at the front ; umbilici closed;
outer lip thin at fhe front, thickened by callus at the sides ; inner lip

BULLETIN OF THE LABORATORIES

.18

thickened by callus, which is sometimes in the form of a broad, prom-
inent lobe, and that at the median line ; the last volution is always
marked by- one strong, rugose or nodose median carina, which extends
from the inner Ifp to the front margin ; in most cases there is a more
or less distinct revolving ridge at each side of the median carina, and
of equal extent with it ; the whole surface is also marked by strong
transverse wrinkles and lines of growth, but sometimes the lateral
ridges are wanting. Length and breadth equal.

This species is represented by several recognizable fragments from
Flint Ridge and Bald Hill. The description is quoted for reference.

Bellerophon noclocarinatus , Hall {fide White.)

(Plate III, Fig. 3.)

A number of specimens of a rather large Bellerophon are in ex-
actly the condition figured by White, in the 13th report of the Geologi-
cal Survey of Indiana. The lip seems to be but slightly expanded ;
general form, sub-globose; dorsal surface of outer volution, with a
subnodose median carina which is divided by a furrow, in which at the
bottom is a slightly raised line ; on either side the carina a broad, shal-
low sinus ; proximally the volution marked by prominent distant re-
volving ridges and the carina disappears ; the carina seems to termi-
nate in a slight dorsal emargination of the lip.

None of our specimens preserve the aperture or umbilicus.
White is inclined to believe his B. inspeciosus a variety of this species.

Bellerophon {sub-cordiformis, sp. n.)

(Plate II, Fig. 7 a, b, c. )

A fragment of a small Bellerophon may be noticed, which appears
to, indicate a species entirely distinct from any known to the writer.
Neither the mouth nor the umbilicus is visible,^ but the last coil is evi-
dently very rapidly enlarged. The outline, as viewed from behind, is
cordate; the diameter in the plane of the coils nearly equal to the
width ; middle of outer coil carinate, lip apparently regularly expand-
ed; surface marked by oblique, revolving, rounded ridges, springing
from the median carina and passing toward the lip, between these
ridges are impressed lines, containing prominences disposed at regular
intervals. This peculiarity of the surface markings alone is thought
characteristic. Width, over 0.4 in., height about the same. Should

OF DENISON UNIVERSITY.

19

'a name be required for this species it may be called B. subcordiformis.
(x\ somewhat similar surface ornamentation is found in the otherwise
very different B. pullchellus of Toula.)

Seller ophoji Montfortianus, N. and P.

(Plate II, Fig. I ; Plate V, Fig S.)

The largest Bellerophon found at Flint Ridge agrees with this fine
species. We are able to give more complete figures than hitherto ob-
tained, many of our specimens, though crushed, being entire.

Shell proximally very small, expanding rapidly; aperture enor-
mously expanded, sub-reniform ; outer volution with a deeply impressed
medial sulcus emarginating the lip distally ; lip thin, with a prominent
callous where covering the inner coil. The surface is ornamented by
strong revolving lines, which are separated by about ten striae and are
crossed by fine concentric striae, giving the whole a delicate textile na-
ture. In one of the specimens figured the revolving lines do not
reach the lip, but the zone with only concentric lines seems due to
exfoliation. The surface is also marked by distant concentric plica-
tions which become more numerous proximally. Width of aperture,
1.24, height, .95.

Bellerophon deeussatus, Fleming ? ?

(Plate II, Fig. 12. )

Our figure represents the dorsal surface of the outer volution,
which is marked by a combination of revolving and concentric striae
of nearly equal size and number. There is also a slight median fold.
It is not certain that the identification can be sustained.

Bellerophon carhonarius, Cox.

(Plate II, Fig. 20.)

This, or a closely related species is represented by only a few frag-
ments. (Cf. also B. stramineus. )

“ Shell globose, broadly rounded over the dorsum ; umbilical im-
pressions very small or closed. Aperture transversely sublunate, much
wider than high, and strongly arched, but not expanding more rapidly
than the uniform increase of the size of the volutions ; inner lip nearly
wanting or little developed ; outer lip moderately thick near the umbil-

20

BULLETIN OF THE LABORATORIES

icus on either side, but thinner between; sinus shallow and rounded,
its band obscure or scarcely visible on the costated part of the outer
whorl, sometimes a little concave, or with traces, on each side, of a
faintly marked ridge on the smooth part of the outer volution ; surface,
except on the terminal half or third of the body whorl, ornamented
wdth about 18-2^ simple, rather distinct, revolving raised lines.” This
species is widely distributed.

Bellerophon inarcouianus, Geinitz.

' • (Plate V, Fig. 7.)

Several fragments are sufficient to indicate this species, but add
nothing to the meagre description given by Geinitz and Meek. The
shell is marked only by fine, close, unequal or alternating, revolving
lines and has an aperture like B. montfortianus, which it approaches
in size.

Bellerophon (cf crassus, Meek and Worthen.)

(Plate V, Fig. 6. )

This Bellerophon is derived from the flinty limestone at the sum-
mit of Flint Ridge, and hence its horizon is 100 feet higher than the
shells just described. Though much smaller than B. crassus, it has
much the form of that species, yet the shell appears hot to have been
thick. The umbilical expansions of the lip are broken, but may have
partly covered the cavity. The markings are nearly obliterated, but
there are indications of a mesial ridge on the dorsum. The greatest
diameter is over one inch.

Polyphemopsis inornata, Meek and Worthen ?

(Plate II, Fig. 15.)

Even the generic reference of this specimen must remain doubt-
ful, as it is so largely imbedded in the rock. If a Polyphemopsis, it
resembles P. inornata as nearly as any American species encountered.
P. melanoides from Newtonville would appear to be too slender. Our
specimen is larger than the type of P. inornata.

OF DENISON UNIVERSITY.

21

Macrocheilus s/??

(Plate II, Fig. i6. )

A single specimen, pretty well preserved, but unfortunately not
displaying the characters of the columella, seems to indicate a species,
of Macrocheilus, about the size and form of M. ^nedialis, Meek and
Worthen. The aperture is narrower, however, and the form of its
lower angle is different. It is also but little larger than M. siLbco7'pu-
lentus of Whitfield, but until figures of the latter appear it will be im-
possible to compare them.

Macrocheilus sp ?

(Plate II, Fig. 2.)

A second species is recognized from a badly flattened specimen^
which is perfect enough, however, to show that the species is very like
M. planus, though in its present condition it seems much more robust.
In size and number of volutions it agrees very fully.

Pleurotoinaria sp?

Figures ii and. 13 of Plate II, indicate a species of this genus
with rather high conical spire and revolving as well as obliquely decus-
sating striae. I am not able to suggest its specific affinities.

Pleurotojviaria neivportensis, White (?)

(Plate II, Fig. 18.)

Volutions about five, regularly rounded, very convex, and rap-
idly diminishing in size ; spire short ; lower whorl marked by a spiral
band originating at a notch in the margin of the aperture, consisting
of an elevated striated ridge ; otherwise marked with numerous revolv-
ing lines of which some are larger than others and separated by one
or two of the smaller lines. It is by no means certain that our form
is really this species. In the first place, the shell is flattened obliquely
by pressure, so as to greatly distort the aperture and otherwise alter the
form. Evidently, however, it was a shell of similar form and general
appearance with P. newportensis. The strice differ in being more nu-
merous, though the obliteration of the minuter sort would remove this
difference. P. newportensis is further described : Aperture sub-cir-

22

BULLETIN OF THE LABORATORIES

cular in outline, its margin oblique; outer lip having a broad notch a
little above the middle; inner lip thickened. Our specimens indicate
a species at least a third smaller than White’s types.

EuomplialiiS sp ?

(Plate II, Figs. 4, 5, and Plate V, Fig 5.)

A small species is represented by impressions and fragments of
the dorsal and umbilical side. About three whorls are preserved, meas-
uring .42 in diameter. The dorsal or upper surface seems to be
marked by a sharp carina along the outer margin and to have been or-
namented with strong lines of growth. The umbilical surface is less
perfectly preserved, but had a series of sharp prominences along the
inner margin and semi-carinate ridges elsewhere. Since writing the
above more perfect and larger specimens have been found. This spe-
cies is also found in the flinty limestone at the top of Flint Ridge.
The existence of prominences along the inside of the umbilical whorls is
a constant character, and the revolving lines seem less so. The
sharp external carina of the opposite or upper side is also a character
identical with E. rugosus, but this species differs constantly in the
presence of the prominences on the umbilical edge of the whorl.

Genus Loxonema.

(Plate III, Fig. 2.)

A fine species of this genus is known from a single crushed speci-
men which is represented (partly restored) in our figure. The shell
is 2.20 or more in length, the ' diameter of the largest whorl being
about. 75. The spire is elevated and has an apical angle of 15°.
The number of volutions can not be less than ten (the terminal ones
are absent in the specimen. ) The volutions are convex and are marked
by strong, somewhat oblique plications, about seven in half an inch on
the largest volution. The characters of the lip, aperture and colum-
ella can not be made out, though there is some evidence of a projec-
tion of the lip downward at the lower angle of the aperture. The
shell accords in most points which can be made out with L. plicatum,
Whitfield, but, as there are in the neighborhood of twenty described

OF DENISON DNIVERSn'Y.

23

coal-measure species, many being similar, it is hazardous to identify it
certainly with any of them. ^

LAMELLIBRANCHIATA.

Entoliuin aviculatums Swallow.

(Plate I, Figs, i, 2 ; Plate III, Fig. jo.)

It is submitted that it is impossible to rescue the Fntoliums of the
carboniferous from the inextricable confusion into which they have
fallen. Nevertheless the name F. aviculatum doubtless applies to a
species of wide distribution in the coal-measure rocks, however it may
be related to sub-carboniferous species.

The remarks of Prof. Meek, under his description of an Fntolium
from the Waverly, are instructive as showing the difficulty of discrimi-
nating species in this group. He also says Prof. WinchelPs type
[of Pernopecten shumardianus] seems to agree exactly, in all constant
specific characters, with Entolium aviculatum. Swallow, already mentioned,
from the coal-measures. So we have here a remarkable case of shells
presenting extremely little or no constant specific difference, and yet
differing in a character of the hinge that seems to be of generic impor-
tance.”

Although Prof. Hall figures Pernopecten shumardianus from New-
ark, O., we have found no such form, though another and smaller
shell apparently belonging to Pernopecten, is rarely found in the Wa-
verly. We thought for some time that by mistake some Flint Ridge
or Bald Hill specimens (coal-measures) had been labeled WNverly, but
none of our numerous specimens from the coal-measure shales show
the crenulated hinge prominences ascribed to the species in question.
Mr. Meek, however, supposed P. shumardianus to be without the
crenulated hinge and others have decided that Fntolium is synonymous
with Pernopecten. If that be the case it is difficult to see how F.
aviculatum can be distinguished from Pernopecten shumardianus.
The hinge in all specimens seen from the coal-measures shows, instead
of a prominence, an impressed line on the left valve, at the point des-
ignated in Penopecten by a crenulated ridge, this appears on the out-
side of the valve as a ridge, the shell being very thin. On the ventral
valve in the same position is a ridge, designed, it 'would seem, to fit
into the groove of the other valve. The left valve, however, has its

24

BULLETIN OF THE LABORATORIES

ears produced upward so that the hinge line is straight and distant
from the groves, while on the right valve the ridge is at the upper
margin. Thus Prof. Hall has compared the hinge line of a right valve
of Pernopecten limiformis with the left valve of P. shumardianus on
Plate I, of the Report of the State Geologist of New York. The pro-
jecting ears of the left valve evidently prevent the easy dis-articulation
of the valves in this monomuscular form perhaps especially liable to
such an accident.

Shell very thin, compressed, very ineqi-valve, height of left valve
noticeably greater than width; general outline (without the ears)
acutely oval, lower outline a nearly regular curve, extending posteri-
orly about one third the height of the shell, anteriorly two-thirds
the height, posterior margin thence proceeding upward nearly
a straight but oblique line to the angle of the ear, but rather
abruptly angled near the union of the upper and middle thirds
of the height, the anterior margin is strongly curved inward
at the same point and thence continued in a . line at about
the same angle as the opposite side to the ears, which pro-
ject slightly upward so that the angles formed by the hinge line
and the lateral margins are about right angles ; position of the hinge
of the opposite valve indicated by an impressed groove appearing out-
wardly as a ridge; ears set off by distinctly marked furrows ; ■ valve
marked by numerous faint concentric lines and very feeble distant ra-
diating striations.

Right valve as high as wide, its lower margin qvenly rounded,
the curve continuing on both sides to nearly yi the height, the front
side more produced and abruptly curved, front ear longer but less high,
so that the hinge line, which is nearly straight, seems oblique to the
long axis of the valve.

Entolium atteniiatuin, sp. n.

(Plate I, Fig. 1 1, )

A very slender species represented by a single left valve is derived
from the flinty limestone at the top of Flint Ridge, and thus loo feet
higher than the horizon of the above named. This species was much
more elongated, and had a very narrow hinge. The lower margin is
uniformly but strongly curved, while the sides are nearly straight and
inclined at a very acute angle to each other. The anterior margin

OF DENISON UNIVERSITY.

25

curves somewhat abruptly at its upper third, the posterior margin is
straight. The ears are acute and depressed, while the beak is acute
and somewhat elevated. There seem to be indications of the hinge
ridge or furrow peculiar to this genus. Markings obscure, but appa-
rently consisting of few radiating and many faint concentric lines.
Length, the greatest width. Hinge somewhat over the great-
est width.

Genus Aviculopecten.

The literature at command makes an attempt to study the numer-
ous members of this genus rather unprofitable, but in as much as sev-
eral have been figured we may briefly allude to them.

v^viculopecteib hertzeri, Meek.

(Plate I, Figs. 5 and 10.)

Specimens corresponding in size and form to Meek’s type, are
numerous, and occasionally one encounters the same shell of double
the usual size, but retaining the characteristic marking. This species
may be recognized by the close thread-like concentric and radiating
lining producing a peculiar textile structure. This may be seen from the
inside of the shell also. In the smaller specimens seen the shell sculp-
ture is somewhat different. The entire shell is covered by strong radi-
ating costae in pairs, the costae being closely crowded but separated by
deeply impressed grooves between the pairs. These radiating lines
are crossed by very fine and numerous concentric striations. The
pairs tend also to again bifurcate toward the lower margin. This
dichotomous arrangement of the very strong radiating ribs seems to
distinguish this form constantly, though it may be, as at first supposed,
the younger variety of A. hertzeri.

Aviculopecten? sp?

(Plate III, Fig. 18.)

The shell figured resembles A ? sublobatus, Phillips, but is still
more elongate. It may be that the shell has suffered some distortion,
though there little indication of it, and until other specimens are seen
it will not do to rely too much on the figure. The left (?) valve fig-

26

BULLETIN OF THE LABORATORIES

iired IS elongate, almost linguliform; beak acute, prominent; hinge line
less than yi the height of the valve, which is strongly convex near the
median line and ornamented with fine radiating and concentric striae.

Aviculopecten coxanus, M. and W.

(Plate I, Figs. 4 and 17.)

This little shell is not uncommon at Flint Ridge- and Bald Hill,
and curiously enough is generally preserved so as to expose the inte-
riors, this fact led to some confusion, as the shell is so thin that the
markings involves the whole shell and the inside is therefore a nega-
tive copy of the outer surface. Our largest specimen is of the size of
the specimen figured by Meek, but presents the inner surface. This
species maybe recognized by the slight obliquity (more than indicated
by Meek) and alternating striae. The striae seem to be uniformly more
prominent than in the type, the striae are also square in section. The
posterior ear is acute with its posterior outline concave, less distinctly
separated from the valve than the anterior ear, which is less acute.
Length, .50; width, .49; hinge line, .40. About 14 primary striae on
the body of a valve of this size with alternating minute ones.

Aviculopecten scalaris, sp. n. ?

(Plate I, Fig. 8.)

We have been tempted to regard this as a form of A. occidehtalis,
but there is a marked dissimilarity in the markings. The shell is
equivalve, the valves nearly alike; somewhat longer than wide; hinge
line shorter than greatest width ; lower margin a uniform curve ; front
margin strongly curved, anterior ear separated from the body of the
shell by a sharp depression ; posterior ear larger, more excavated on
its lateral margin and less distinctly marked off from the valve. The
valves are marked by fascicles of triangular, prominent striae or ridges,
which increase by bifurcation, usually with a feeble preference for
dichotomy; these ridges crossed by sharply marked concentric angu-
lar depressions causing a resemblance to the treads of a stairway ; also
concentric lines most prominent upon the ears. The coarser wrinkles
might have been thought accidental, but for the constancy with which
they appear. After making the corrections indicated by Meek (Geo-

OF DENISON UNIVERSITY.

27

logical Siirv. Neb., p. 193) in the figure of Geinitz, the dissimilarity
in form is very slight and it is suspected a wider comparison would
prove these shells identical.

Aviculopecten sorer, sp. n. ?

(Plate I, Fig. 7, and Plate III, Fig. 16.)

We have a number of specimens of a fine species remarkable for
the beauty of the surface markings, but all too imperfect to very satis-
factorily characterize. The form, exclusive of the ears, is sub-trian-
gular, both anterior and posterior margins being concave or nearly
straight. The greatest breadth is below the middle and the lower
margin is a uniform, rather shallow curve. The ears are large and
sub-equal, the anterior are (?) most acute. Shell ornamented with
prominent distant ribs separated by three or more smaller ones, all be-
ing nodose in the path of concentric markings or, rather, the nodose
character produces the effect of concentric lines crossing the striae.
This shell resembles A. scalaris in general configuration very closely,
more closely than indicated by the description, but it seems to vary
greatly. The nodose character is also variable. No perfect specimen
has been found, but many fragments indicate a species about the size
and form of A. scalaris, with rounded distant striae, separated by
crowded finer ones. The ears are broken in all the specimens seen,
but we presume the valve. Fig. 16, Plate III, is opposite to that of
A. scalaris Fig. 8, Plate I, and so there is a slight difference in
outline.

Aviculopecten sp?

(Plate I, Fig. 6.)

A little shell similar in outline to A. (Crenipecten) leon, Hall, is
known from the single valve figured. It is peculiar in the relatively
very short hinge and restricted ears, as well as in the ornamentation
which consents of sharply defined, though small, ribs arranged in
rather distant pairs. The specimen is a left valve and rather oblique.
The general outline is acutely ovoid, the beak being nearly central and
quite prominent. The posterior ear is very small and acute, anterior
ear larger, with a more concave outline.

28

BULLETIN OF THE LABORATORIES

Crenipecten Foerstii, sp. n.

(Plate III, Fig. 9, 9a.)

The species figured is, next to Entolium aviculatum, the most
common bivalve at Flint Ridge, and finds its counterpart in Streblop-
teria (?) tenuilineata, M. and W, Indeed, it is riot improbable that
the two are identical, in spite of marked points of divergence.
It would be impossible to reconcile the description of that
species with our specimens, while Meek’s drawings are equally
different. The reference to Streblopteria is certainly erroneous,
although it is fair to add that Meek and Worthen had not
seen the hinge. ‘ The genus Crenipecten, as defined by Hall,
includes a diversity of forms ranging from such symetrical, long-
hinged species as C. Winchelli to those oblique species represent-
ed by C. amplus.and our own. A single specimen (Fig. 9 a.) from
Mr. Foerste’s collection, gave evidence of the crenulated hinge area,
from the impression, the shell having been exfoliated. The characters
of Streblopteria are as follows :

“Shell ovate or rounded, obliquely extended towards the anterior
side; posterior wing broad, undefined, nearly rectangular, extending
nearly as far as the posterior margin of the shell; anterior ear small,
deeply defined; surface smooth or radiately ridged; one large, faintly
marked, muscular impression a little behind the middle; one short,
narrow tooth slightly diverging from the hinge on the posterior side of
the beaks ; ligament confined to a narrow, simple facet on the hinge
margin.” .. ,

In comparing our specimens with the figure of S. tenuilineatus
we find, aside from its greater average size and different markings, that
the anterior margin is more produced, and the anterior ear is much
more sharply defined. There is little doubt that the two forms are at
least congeneric.

Shell below the ears subcircular, but moderately convex, equi-
valve. Right valve with the anterior ear produced, rounded in front,
separated from the valve by a deeply impressed, concave auricular
sinus; posterior ear nearly rectangular, slightly concave in posterior
outline, separated from the valve by an impressed line ; hinge line one
half the height of the valves. Left valve of same form, but the ears
less distinctly separated; hinge line less than half the height, anterior
ear with concave front outline,. The beaks are acute and moderately

OF DENISON UNIVERSITY.

29

prominent. Surface marked by numerous close, minute, concentric
lines, and numerous irregular, concentric wrinkles which give a pecu-
liar appearance to the shell, not shared by other species. These
wrinkles are less marked on young shells. There are also, in most
cases, indications of radiating lines, which in the larger shells are
strong striae or ribs, at a distance from each other. Length of mature
specimen .70, width, a trifle less, hinge of right valve, .34. A very
similar, or probably identical form, occurs in the Waverly, which may
prove to bear a name ranking the one now proposed.

Genus Lima.

retifera, Shumard.-
(Plate IV, Fig. 2^\ Plate V, Fig. 3.)

Shell obliquely subovate; posterior side short; anterior side ob-
liquely produced; cardinal border rather short; lower margin a nearly
uniform curve ; anterior margin nearly equal, anterior one obtuse in
outline, posterior ear rectangular; surface of valves marked by strong
angular radiating costae and concentric striae. Height . c;o; length .70.
Our specimens were, for the most part, very small, but otherwise
agree with the description of this species, which is widely though not
abundantly distributed.

Roemer, in his paper entitled “ Ueber eine marine conchylien-
Fauna im Steinkohlengebirge Oberschlesiens,” figures a little shell,
very much like this, but somewhat less oblique He identifies it with
a query, with Pecten interstitialis, Phillips.

Genus Solenomya, ham?

The generic reference is here very doubtful, d'wo of the forms
are evidently closely allied, while the other might probably be more
properly referred elsewhere, if we knew anything of its hinge.

1. Solei%oinya (?) anoclontoides , Meek.

(Plate IV, Fig. TO.)

This form agrees with Meek’s description and figures, except that
the anterior margin is much less acute, that portion of the shell not
extending into a heel-like prolongation below, as repiesented in his

30

BULLETIN OF THE LABORATORIES

figure. The anterior margin is subtruncate in some specimens, and the
lower margin is nearly straight and parallel with the axis of the shell ;
the posterior margin is evenly curved, the greatest convexity being in
the middle of the height of the shell. The largest specimen measures
1.20 in length and .75 in width, the smallest, 1.12 by .66.

The surface in each was covered by rather strong, variable, con-
centric lines. The middle of the valve is nearly uniformly convex,
sometimes with a shallow depression extending from near the beak to
the lower margin; shell slightly gaping behind.

2. Solenomya i?) meelciana, sp. n •

(Plate IV, Fig. 9 )

This is a much more elongated species or variety, otherwise almost
identical, though the specimens observed were all smaller. Nearly
quadrate, elongate, more than twice as long as wide ; sides parallel,
straight ; posterior outline gently curved; anterior outline somewhat
truncate, not produced ; convexity somewhat greatest near the beak,
but entire valve nearly equally convex, sloping gently and almost
equally to the entire margin. Length, 1.05, width, .50. Surface
marked as in the previous variety. Although Meek (Geol. Surv. Neb.
p. 23,3 ; Plate IV, Fig. 7,) refers to Edmondia a species almost cer-
tainly identical with ours, as E. reflexa, comparison with the typical
form, shows that it is far from probable that the specific reference (if the
generic) could be sustained. It may be better to apply a new name,
as suggested, and await farther evidence as to the relation to S. ano-
dontoides.

Solenomya suhradiata, sp n-
(Plate III, Fig. 8. )

This species somewhat resembles S. radiata, M. and W., but is
much more elongated and expanded posteriorly. The shell is very
thin and is somewhat compressed in the only specimens seen. Very
narrowly oval and slightly convex ; posterior dorsal line straight ; pos-
terior margin a regular curve ; lower margin a uniform slight curve ;
umbo 4-5 the length from the posterior extremity, anterio-dorsal line
convex, inclined abruptly from beak ; anterior part of shell produced
below in a strong ‘‘ heel.” Surface with very obscure concentric lines

OF DENISON UNIVERSITY.

31

and still more faint equidistant radiating lines. These latter are not
very numerous and could easily be overlooked. Length r.20,
width .45.

The radiating stri^ or impressed lines do not spring from the
beak, but seem to terminate in the posterior hinge line ; they are only
obvious on the posterior third of the shell.

Genus macrodon, Lycett.

1. Macrodon ohsoletus, Meek.

(Plate IV, Fig. 19.)

Shell elongate sub-quadrate or sub-rhombic, moderately convex,
greatest convexity forming a gentle prominence extending from the
umbo to the lower posterior margin. Upper posterior portion nearly
plane, inclining gently to the obliquely truncated posterior margin ;
this part of shell only marked by faint radiating striae. Hinge line
straight, parallel to it two or three impressed lines separating the teeth,
these showing in the partially denuded shell figured. Beaks removed
but a short distance from the front margin. Anterior margin gently
curved, meeting the hinge line by an abrupt right angle. Lower mar-
gin nearly straight or slightly convex. Entire surface marked by few
concentric lines of growth.

2 .Macrodon tenuistriata, M. and W.

“ Shell small, rhombic-oblong, rather distinctly convex along the
umbonal slopes and near the front, a little more than twice as long as
high ; basal and cardinal margins parallel, the former nearly straight
or somewhat sinuous near the middle ; cardinal margin straight, not
quite equalling the greatest antero-posterior diameter ; anterior side
rounding up from below so as to meet the hinge nearly at right angles;
posterior basal margin narrowly rounded ; posterior margin obliquely
truncated, often a little sinuous above ; dorsal region behind the um-
bonal slope compressed; beaks compressed, a little flattened, incurved
and rising somewhat above the hinge margin, located about half way
between the middle and front; flanks broadly impressed or concave
from the umbonal region obliquely backward to the faintly sinuous
part of the base ; surface ornamented by distinct marks of growth

32

BULLETIN OF THE LABORATORIES

crossed by radiating markings, well-defined behind, forming anteriorly
crowded, obsolescent striae.”

Our specimens are smaller than those described by Meek, and
more convex, but otherwise they agree. Length, .36, height, .16.
This shell is almost identical in outline with M. obsoletus, but is much
more gibbous. The possibility that it is merely the young of that spe-
cies cannot be disputed.

S. Macrodon carbonaria, Cox.

(Plate IV, Figs. 21 and (?) 14.)

This is a very pretty and somewhat common species. It is easily
recognized by the strong radiating ribs which are much more promi-
nent in the area marked off by the posterior umbonal ridge. The lar-
gest specimen measures 1.40 long by .625 wide and is truncated ob-
liquely behind. The concentric markings are plainly seen.

Figure 14 shows the inside of a valve which, from the inferior
size and projecting anterior margin, could be identified with M. tenu-
istriata, M. and W., though, as the shell is but a fragment, it would be
venturesome.

Genus Prothyris.

Prothyris elegans, Metk.)

(Plate IV, Fig. 3.)

The specimen on which this identification rests is imperfect and
the anterior is not fully preserved. The description of the species is
as follows : “ Shell compressed, elongate oblong, the length being

about three and a half times the height; ventral and dorsal margins
straight or a little arched ; the latter with a faintly defined marginal
furrow, below which there is usually an obscure ridge, also parallel to
the dorsal margin ; posterior extremity obliquely sub-truncate, the most
prominent part being below the middle ; beaks compressed, depressed,
not distinct from the dorsal margin, and placed about one-eighth or
one-ninth the length of the valves behind the anterior extremity;
notch of the anterior margin well-defined and extending about one
half way up to the beaks; ridge from the inner angle of the notch
narrow, flat, widening slightly from above ; anterior margin above the

OF DENISON UNIVERSITY,

33

notch rounded, and having the appearance of a flattened ear ; surface
striae nearly obsolete on the upper half of the valves, and more dis-
tinct on the ventral and antero-ventral regions.”

Genus Allorisma.

Allorisina costata, M. and w.

(Plate III, hflg. 7, and Plate IV, Fig. 28.)

We have not been able to compare this fine species with types,
but in spite of its great dissimilarity, notably in size, from specimens
referred to this species by Mr. Meek, we regard this as identical with
the Illinois species. The generic reference is far less satisfaotory.
Indeed, it is suspected that an examination of the hinge would prove
this an independent genus.

Shell medium sized, elongate ; upper and lower margins sub-par-
allel; beak prominent, anterior; anterior margin short, convex ; shell
produced and slightly attenuated posteriorly, posterior margin sub-
truncate ; greatest depth of the shell a little posterior to the umbo ; sur-
face marked with (12) strong, distant concentric cost^ extending from
the anterior margin to the prominent posterior umbonal ridge, where
they abruptly cease. The surface above the ridge being marked by
fine concentric lines and a well marked ridge extending from the beak
toward the centre of the posterior m'argin. Our specimens embrace
impressions as well as the right valve. The space between the costae
is gently concave and smooth and there seems to have been a radiating
rib upon the summit of the umbonal ridge into which the concentric
ribs merge. There are indications of an impressed line along the
hinge line posteriorly. The outline of the posterior margin seems in
the best preserved specimen, bi-truncate, in others obliquely truncate
in one straight line; other minor differences are referred to the condi-
tions of preservation. Length, 1.40; height, ,50. Comparisons were
drawn in our note book with Orthonota, to which it may be allied.

Allorisma Geinitzii, Meek. (?)

(Plate IV, Fig. 27.)

This small species resembles, somewhat, A. gilberti. White, though
it is by no means so much produced posteriorly. Shell very small,

34

BULLETIN OF THE LABORATORIES

elongate; not very gibbous ; anterior dorsal margin inclined from the
beak to the anterior end of the evenly curved lower margin, with
which it united by an acute angle ; posterior dorsal margin gently sinu-
ous, four times as long as the anterior ; posterior margin somewhat
obliquely truncate, more prominent below ; greatest height at the umbo,
posterior part somewhat narrowed. Surface marked by irregular con-
centric striae and, at least posteriorly, by a few indistinct radiating
lines. Length, .33, height, .17. It is more probable that this species
is new, but some hesitation is felt in separating it from a minute form
of nearly the same outline, in view of the poverty of our material and
the variability of the species.

AllorisiTia szibcuneata, M. and H.

(Plate IV, Fig. I.)

I am by no means certain regarding the identification of the frag-
ments which have been referred to this species. However, it is cer-
tain that a shell of about the same size and having the same form about
the umbo and the same coarse markings is found at Flint Ridge. The
species, moreover, is widely distributed, occuring in Utah and New
Mexico, as well as Indiana and others of the central states. The de-
scription is as follows : Shell large, twice or more times as long as
high, gibbous anteriorly, compressed posteriorly, where the valves gape
somewhat ; basal margin nearly straight, curved rapidly near the ante-
rior, more slowly at the posterior ends; dorsal margin convex posteri-
orly, giving the posterior outlines a somewhat spatulate form ; front
margin rather narrowly rounded; beaks projecting well beyond hinge
line; surface marked by well defined concentric lines. Length, near-,
ly four inches.

Genus Clinopistha.

Clifiopistha radiczta, Hall.

(Plate III, Fig. II.)

Our specimen was associated with the forms elsewhere referred to
Edmondia aspenwallensis, and resembles them very nearly. The out-
line differs perceptibly, however, and the faint and very rugular con-
centric stri^ are quite unlike the folds which ornament the shell of

OF DENISON UNIVERSITY.

35

Edmondia. No traces of radiating lines are preserved, but the con-
dition is such as to explain their disappearance.

Our specimen is rather less ventricose than that figured by White,
but is also smaller. Length, .52, height, .40.

Genus Pleurophorus, King.

1. Pleurophorus tropidophorus , Meek.

(Plate IV, Fig. 15.)

This pretty shell is not uncommon at Flint Ridge. I am not sure
that there are not two closely related species differing chiefly in size.

2- Pleurophorus suheostatus, M. and w. (?)

(Plate IV, Figs. 16 and i6a.)

We have a number of small specimens which vary so much
among themselves that the variableness may account for some discrep-
ancies between them and the description of Meek and Worthen.
Ours is a smaller form and the larger examples have the sinuous lower
outline of P. subcostatus. A very much smaller and more compact
form figured on the same plate, Fig. 7. may be the young of the
same species.

Genus Cypricardina, Hall.

Hinge unknown, shell elongate trapezoidal, moderately com-
pressed, beaks anterior or sub-anterior, slightly prominent, surface
marked by rather prominent concentric plications or striae. (Hinge
with well deYeloped hinge- plate, with one linear tooth in one valve
and two in the other, and other, minute linear teeth shorter than the
others, Synopleura^ Meek. )

Cyprieardina (?) earhonaria, Meek.

(Plate IV, Figs. 17 and 18.)

This shell was described from the locality whence our specimen
came, so that it may- be best simply to quote the description given by
Meek: Shell small, longitudinally oval, less than twice as long as

high, the widest (highest) part being under the posterior extremity of

36

BULLETIN OF THE LABORATORIES.

the hinge ; rather gibbous, usually with a broad impression extending
from the beaks obliquely backward and downward to the middle of
the base of each valve ; anterior side extremely short, or nearly obso-
lete, convex, and rounded; posterior side broader, more compressed
or cuneate, with its upper edge straight and sloping obliquely back-
ward to the regularly rounded posterior margin ; base broadly and
slightly sinuous in the middle, and rounding upward at the extremities;
hinge line straight, between one-half and two-thirds as long as the
valves, ranging at an angle of about 25 deg. with the oblique, longer
axis of the shell, so as to meet the sloping upper edge of the posterior
margin at a very obtuse but moderately well-defined angle, this im-
parting to the somewhat compressed posterior dorsal region a very
faintly alate appearance ; beaks extremely oblique, depressed nearly
to the dorsal margin, very nearly terminal, and scarcely projecting be-
yond the rounded outline of the anterior extremity. Surface orna-
mented by fifteen to twenty exceedingly regular, well-defined, sub-im-
bricating, flattened ridges or undulations, that gradually become small-
er and more closely approximating on the umbones. Length of larg-
est specimen seen 0.55; height at the posterior extremity of
hinges -32.”

The specimen figured is but 0.45 long, but agrees well with the
description, it being a partial cast, shovVing hinge teeth distinctly.

Gervillia i?) ohioense, sp. n.

(Plate IV, Fig. 13, and Plate III, Fig. 12.)

(Cf. Avicitla lon^a, Meek.

Two specimens have been secured from Flint Ridge, both some-
what imperfect, but indicating a species quite different from Monop-
teria gibbosa. The whole question of the generic affinity of the car-
boniferous species referred to Gervillia, Monopteria, Blakevellia, etc.,
is very obscure.

The upper outline is nearly straight ; beak distant nearly one-third
''the length from the anterior margin; posterior wing greatly produced,

• posterior margin deeply sinuous ; posterior, produced part of shell
■ keeled ; anterior wing acute, its margin very oblique and slightly curved
to its junction with the lower margin, with which it forms a continuous
symmetrical curve. Hinge line, .65, height, .45, greatest length, .85.

OB' DENISON UNIVERSITY.

37

The surface is marked by rather obvious concentric lines. The pos-
tero-inferior projection is greater than that of the hinge line. Fig. 13
of Plate IV, represents a specimen in which part of the posterior out-
line is obscure, while that figured on Plate III, Fig. 12, had its ante-
ro-inferior outline crushed in. By combining the figures a fair idea
of the shell can be obtained. The specimen figured on Plate IV,
is much flattened and somewhat distorted, it should be restored by
producing the upper, posterior angle and the lower, posterior lobe.
From A. longa, which it most resembles, it differs in being not only
larger, but less produced posteriorly, the posterior sinus is much less
and the anterior part of the shell does not appear to have the oblique
sulcus described for that species. (We have, since writing the above,
found the long posterior tooth characteristic of Avicula.)

Myalina {cf. recurvirostris, M. and W.)

N (Plate V, Fig. 4.)

A single fragment indicates a species of nearly the size of the spe-
cies quoted. It is not sufficient, however, to furnish the basis for ac-
curate identification. The outline probably is not correctly restored
in our drawing, but the shell was flattened, causing uncertainty as to
the natural course of the striae. The surface is marked by very coarse
but regular and distant furrows, as well as the finer concentric lines.

Myalina sp?

(Plate IV, Fig. 20.)

Only a small fragment was found to indicate a species, like M..
Meliniformis, M. and W. It belongs to the group of M. subquadrata,
M. sublamellosa, Eldridge, M. perattenuata. Meek, M. Flemingii,
King, etc., but is a very small species, with acute beaks and strong
striae.

Myalina {?) SWallovi, McChesney.

(Plate IV, Fig. 6 )

This familiar and widely distributed species is common here also.
The general aspect is unlike most species of Myalina, but more like

38

BULLETIN OF THE LABORATORIES

Modiola. The surface is marked by few indistinct concentric lines.

Genus Aviculopinna, Meek. ■ ■

“ Very elongated siibtrigonal, equi-valve, with slightly indicated
sub-terminal beaks, the shell being, produced in front of them, gaping
posteriorly ; hinge line very long, edentulous. ”

1. AviGiilopinna amsricana, Meek.

(Plate I, Fig. 20. )

Our fragmentary specimen is insufficient to warrant a description,
but is obviously a member of the old genus Pinna. In size and ascer-
tainable characters it seems to correspond with the species quoted
above. We are unable to discover that the beaks are not anterior, but
this may be due to the imperfect condition of the fossil. The charac-
ter of the ligament grooves is well shown in this specimen. The only
tangible' distinction between Pinna and Aviculopinna being the posi-
tion of the umbo, the generic reference is but provisional.

Solen? sp?

(Plate I, Fig. 19.)'

We have figured a fragment which seems to indicate a Rasor shell
about as completed in outline in the drawing. The piece is too small
to characterize, but attention is called to it to stimulate collectors to
examine the rocks for more complete specimens.

Eclmoridia icf. aspinwallensis, Meek )

(Plate IV, Fig. 4,; Plate III, Fig. 17.)

We have a considerable number of specimens of various sizes,
but all of the larger individuals are imperfect, while the smaller ones
•differ considerably from the species quoted. The shell is covered with
strong concentric folds and very numerous striations. The posterior
margin is broadly and evenly rounded (sub-truncate in the larger ones);
the beaks are not prominent ; the lower outline is a regular curve ;
the anterior margin seems much shorter than in types of E. aspinwall-
ensis; the. convexity is greatest in front and above the middle and
there is sometimes a posterior umbonal ridge, nearly reaching the mar-

OF DENISON UNIVERSITY.

39

gill. Hinge and beaks not clearly seen. Length of small specimen,
,55, height, .50 ; larger specimen, .85 by .70. ’ ^ :

Genus Astartella. , '

Astartellci Jfewherryi, Me k. -r
(Plate IV, Fig’. 33.)

This species is very abundant and varies in size greatly, but ad-
heres strictly to the same type.

Astartella vera, Hall. (??>

A species about the same size as the last is less abundant, it seems
to correspond with the form figured in the second voL of Ohio Paleon-
tology, Plate XIX, Fig. i. It differs in outline from the latter, but
the shell figured was evidently broken, as shown by the direction of
the concentric ribs, the posterior wing being broader than represented.
It differs from A. Newberryi, chiefly in the somewhat coarser stri«.

Astartella varica, McChesney.

( Plate IV, Pfig. 31.)

This species is not very well represented in our collections. It
attains as great or greater size than A. Newberryi, but is more flattened,
with only a slight posterior umbonal ridge, but the specimen figured in
the Ohio Paleontology, was evidently badly flattened, as the umbonal
ridge is much more distinct than there represented. Several of our
specimens were in the same state of preservation.

Genus Microdon, Conrad,

The reader is referred to the discussion of this genus, in the 13th
Annual of the Indiana State Geologist. It seems very probable that
our specimens are generically if not specifically identical with the little
shells found in the Spergen Hill, Indiana, limestones.

40

BULLETIN OF THE LABORATORIES

Microdojh icf. subelliptica, Hall.)

( Plate IV, Fig. 32. )

Both valves are preserved and are nearly alike. Shell very small,
somewhat trapezoidal, obliquely truncate behind, height over four-
fifths the length, gently and evenly convex ; dorsal margin, behind the
beaks nearly straight, the gently concave cardinal margin forming
nearly a right angle with it; lower margin a uniform curve. Posterior
umbonal region evenly convex, but with evident ridge. The surface
of the shell is marked by fine yet distinct concentric lines, there being
about 21 upon a shell .20 high. Although the hinge has not been
seen it seems reasonably sure that the generic reference is correct,
making the first instance we remember of its occurrence in the coal-
measures.

Genus nuculana.

J^'uculana heUistviata, Stevens.

(Plate IV, Fig. 26. )

This very pretty shell is abundant. Our specimens are much
smaller than the types. They resemble in form and markings the
European Leda attenuata, yet probably are correctly identified with
the West Virginia species. The species occurs also in Indiana.

Genus Schizodus, King.

Shell trigonal, rounded anteriorly, attenuated behind; rather thin,
smooth, with an obscure oblique ridge; ligament external ; hinge teeth
2.3, rather small; anterior adductor slightly impressed, removed from
the hinge, with a pedal scar close to it ; pallial line simple.

The reference of species to this genus upon the evidence of ex-
ternal form alone, can only be provisional. There are over twenty
species of fossil forms attributed to this genus.

Six species from the coal-measures of this country are described,
while there seem to be at least four forms among the specimens de-
rived from the shales at Flint Ridge. It is frequently difficult to de-
termine what variations are due to distortion, especially in thin-shelled
specimens like these, which are usually more or less flattened. The

OF DENISON UNIVERSITY.

41

American species are S. cimeatus, wheeleri, ampins, perelegans, oc-
cidentalis, and curtus.

1. Schizodus affijiis, sp if) n,

(Plate IV, Figs. 22 and 22a.)

This species is represented by nearly perfect casts of both valves,
which are similar in form though various in size. The description will
refer to the specimens rather than the species they represent. Right
valve ovate, sub-trigonal, greatest convexity being about one-third from
beak and one-third in length ; anterior margin broadly curved, its
curve varying little from an arc of a circle, a little truncated above ;
lower margin much less curved to the sharp angle at its posterior ex-
tremity, which is produced as the termination of a prominence begin-
ning at the umbo as a sharp ridge extending as a low fold to the mar-
gin ; posterior margin slightly convex, inclined forward entering the
upper margin by a gentle curve. The beak is distant one-third the
greatest length from the anterior margin and is but moderately convex.
Surface apparently with fine concentric lines and deeper lines of
growth. Length, 1.20, width, 1.03; convexity apparently not
over 0.50.

Schizodus cimeatus. Meek, differs most notably in the position of
the beaks, which are located only one-quarter from the anterior mar-
gin, and as a result, the posterior part of the hinge line is much longer
and the anterior broad margin as seen in our shell is absent. Our speci-
men as figured is possibly somewhat flattened.

2. Schizodus sub-circularis, sp. n.

( Plate IV, Fig. 24. ) ,

A still smaller species or variety from the same rocks differs chief-
ly in having the beak near the middle line of the shell. It is known
from a single left valve. The anterior and lower margins are contin-
uous parts of almost a circle, which is only a little produced posterior-
ly; the posterior margin is inclined; beak sub-median, posterior um-
bonal ridge not sharp. The shell is moderately convex and is nearly
smooth, except for the distant lines of growth. Length, .63, width,
.59, convexity, about .20 (single valve).

42

BULLETIN OF THE LABORATORIES

3. Schizodus wheeleri, Swallow.

(Plate III, Fig. 15.)

This species is identified beyond question and is recognized by
the great prolongation of its posterior side. The beaks are prominent'
and situated over one-quarter the length of the shell from the anterior
margin. The anterior part of the shell is moderately convex, while
that posterior to the sharply defined ambonal ridge is greatly com-
pressed. The lower margin is very long and evenly convex, termi-
nating posteriorly in a prominent acute angle; posterior margin ob-
liquely truncate; dorsal margin deflected posteriorly. Length, 1.20 ;
height, .80. Surface marked by very fine concentric lines.

4. Schizodus cuueatiis, Meek. (?)

(Plate IV, Fig. 23.)

It is very strange that the original localities of this species have
yielded us four species besides, but no typical example of that one.
The fragment drawn is referred here only because it indicates a spe-
cies produced posteriorly somewhat and different from S. wheeleri.

I am inclined to believe that S. cuneatus is not a valid species.

5. Schizod^US CZtrtuS, Meek and Werthon. (?)

A single specimen, showing parts of both valves, agrees most
nearly with this species, but is more like a form figured by Meek, U.

S. Geol. Surv. Neb., Plate X, Fig. 13d. This he says is probably a
different species. In S. curtiLS the lower margin is straitened in front
of the umbonal ridge, in this the regular curve is continued. S. ciirtus
is so variable that it is not impossible that our species is identical.

6. Schizodus {?) spelhnani, sp. n.

(Plate III, Fig. 14.)

. A very perfect left valve collected by Mr. Spellman, forms the
basis of this description. The shell is larger than either of the above,
but falls short of the maxiiHum of S. cuneatus, which it somewhat re-
sembles. The margin valve is sub-elliptical, and moderately and
evenly rounded; ventral margin forming a perfect semi-ellipse ; poste-
rior side long, posterior margin rounded, beaks moderately prominent,

OF DENISON UNIVERSITY.

45

rounded, at least one-third length of valves from anterior margin ;
hinge line straight behind the beak ; posterior umbonal ridge rounded,,
not carinate ; surface with imperfectly preserved fine lines of growth..
This species obviously differs from the three above described. It
would seem to resemble S. a77ipliis, but in that the posterior margin is
said to be vertically sub-truncated, also the posterior umbonal slope
has a distinct sulcus not seen in this species.

Genus Placunopsis,* Morris and Lycett.

Placiinopsis recticardinalis , Meek.

(Plate IV, Fig. II.)

This species was described from Flint Ridge and hence the figure
given by Meek is copied, although we have not found the shell as yeL

Genus Posidonomya, Brown.

Posidonoinya fracta, Meek.

Only fragments of this shell which, as Meek says, is almost an
exact miniature of the cretaceous Inoceramus problematicus were
found.

BRACHIOPODA.

Lingula tighti, sp. n.

(Plate IV, Fig. 5.)

This name is proposed for a Lingula of medium size found in
great numbers upon the lamellae of earthy portions of fissile canneE
coal at Flint Ridge, ten miles east of Newark, Ohio. This coal seam,
is number two in the section and has furnished considerable quantities;,
of fairly good coal to local consumers. The Lingulae occur in great
numbers, covering the surface in places completely, and the coal is;
filled with them for a thickness of several inches. Valves nearly sim-
ilar, elliptical, somewhat asymetrical ; one margin nearly straight, the
other more strongly curved, sides narrowed anteriorly .and then rather
abruptly rounded ; width equal to over one-half the length; beak near-
er the straight margin ; shell covered with brown, finely striate epid-
ermis, which is well preserved ; striae very numerous, crowded, but

44

BULLETIN OF THE LABORATORIES

regular, somewhat umbricated about the beaks. Length, .50-.60;
width, ,30.

This species resembles rather closely L. melie, Hall, but is not
narrowed toward the beaks as much as in that species, neither has it
the rather prominent mesial sinus. Our species is more oblique in
front.

The European L. mytiloides is also very similar, but seems to be
uniformly smaller and more nearly resembles L. melie than our speci-
mens. Named for the discoverer Mr. Wm. G. Tight, of Granville.
We have thought this a possible variety of L. umbonata, Cox, a shell
common in the coal-measures. It is nearly of the same size, but is
relatively longer and the margins do not approach each other above as
rapidly. It is quite characterisdc of our species that the breadth of
the shell at one-fourth the length from the beaks is equal or even greater
than the width at the same distance from the front margin. The oc-
currence of this Lingula in cannel coal along with broken fern fronds
supports the theory that it was formed under water by debris brought
in by streams or otherwise.

Athyvis suhtilata, Hall,

(Plate I, Fig. 18.)

'This common and widely distributed species seems not to be
abundant in the rock under consideration, only a few specimens hav-
ing been secured.

Shell somewhat ovate, longer than broad, front margin nearly cir-
cular; valves very nearly equally inflated; ventral valve rather more
convex, the greatest convexity being one-third the distance from the
prominent arched beak; mesial sinus obscure, except toward the front
of the valve, hypodermis marked with radiating lines which sometimes
appear through the shell, especially that at the bottom of the sinus ;
epidermis marked by concentric lines of growth ; dorsal valve uni-
formly convex, without evident fold and with short approximated beak.
The radating lines on the dorsal valves are less regular — they are
simply lines impressed upon the shell by the viscera.

Spirifera opima. Hall.

(Plate ir. Fig. 23.)

Shell rather small, moderately convex, nearly semi-circular to

OF DENISON UNIVERSITY,

45

transversely oblong, variable. Ears and middle of ventral margin
rarely salient. Hinge line nearly or quite equal to the greatest width
of valves. Ventral valve evenly arched, most prominent one-fourth
distance from beak to ventral margin ; lateral portions rounded, not
reflexed; beak moderately prominent, considerably incurved; 'area of
medium size, marked with numerous obliquely upright ridges ; fora-
men rather broad; mesial sinus rather sharply triangular in section,
but not very deep, bearing a medial and four lateral plications, which
are also impressed upon the cast, but do not extend to the beak,
however ; costse of the lateral slopes of the valve triangular in sec-
tion, moderately large, varying in number between to and 14, usually
not bifurcating, but occasionally increased by implantation, costae to-
ward the lateral margins, merging into the area before reaching the
beak. Dorsal valve rather less convex, greatest prominence being
nearer the middle than in the ventral valve; beak projecting slightly,
incurved; mesial fold about in correspondence with the sinus, bearing
five or six simple or bifurcating cost^. The form of the cast of the
ventral valve is sufficiently illustrated by our figure, also the fact that
in this species the hinge area of the ventral valve is ribbed — a point
hitherto unnoticed.

Spirifera cam^irata , Morton.

(Plate 11, Figs. 22.)

This is the commonest Spirifer and one of the most characteristic
fossils of the coal-measures. It is found rarely at Flint Ridge and
Bald Hill in specimens of rather more than medium size.

Shell somewhat trihedral, the hinge line being longer than any
other part, often pointed or mucronate. Ventral valve arched, with a
prominent incurved beak ; area concave, not very acute toward the
extremities, with an almost equilateral foramen, which is partly closed
by a pseudo-deltidiiim ; the mesial sinus is deep, triangular in section,
continuous from the beak to anterior margin. Dorsal valve less convex;
mesial fold well defined, high; sides of the valves nearly uniformly
inclined to the lateral margins, beak small, slightly produced. Both
valves covered with moderately strong radiating ridges which soon in-
crease by division, the cetral one remaining strongest so that they are
grouped in fascicles of from three to five ; striae covering both sinus
and fold; shell also marked by concentric ridges.

46

BULLETIN OF THE LABORATORIES

‘ Spirifera, sp?

(Plate II, Fig. 6,)

A very transverse species is indicated by the cast figured, which -
can not be identified with any known coal-measure species. The na-
ture of the specimen forbids making it the subject of a formal descrip-
tion. It is clearly related to Waverly forms.

Sub- GENUS martinia, McCoy.

Dorsal margin shorter than the width of the shell, the angles of
the hinge-margin shortly rounded; surface smooth or with punctate
(spiniferous?) concentric lines, often with less distinct sub-epidermal
radiating striae ; spiral lamellae small.

Species o^ this group appear in the Silurian and continue into the
carboniferous.

i. Spirifera {Martinia) planoconvexa, Sch.

(Plate I, Fig. 12.)

This little shell was found but once in the shales above the Flint
Ridge coal. It is one of the commonest and most widely distributed
coal-measure species, very possibly identical with S. Urii^ Fleming, of
Great Britain.

Length and breadth nearly equal; the lateral and lower (front)
margins forming a continuous arc like a segment of a circle; ventral
valve rather tumid, being most convex near the middle ; beak pro-
duced beyond the hinge line, incurved; foramen narrow; area con-
cave; dorsal valve flat with minute somewhat incurved beak; surface
of both valves granular, with few, rather indistinct concentric lines.

2. Spirifera (Martinia) lineata, Martin?

(Plate I, Figs. 13a, T3b, 13c.)

The second species is considerably larger than the first, indeed, it
is not certain that two species are not here confused. That figured on
Plate III, Fig. 23, was imperfect, but so far as preserved seemed to
agree with S. lineata, as identified by American writers. In this
specimen, which was largely denuded of the shell, the radiating striae
were very evident and yet on such portions as still retained the shell

OF DENISON UNIVERSITY.

47

the concentric markings were much more prominent. A peculiar fea-
ture is the existence of two rib-like costae, extending from the beak to
the front margin of the valve, which costae pertain to the sub-epider-
mal part of the shell rather than the surface. Our second specimen,
as figured on Plate i, is nearly circular in outline and with very little
evidence of radiating striae, while the concentric markings are very
prominent. This form may be distinguished from S. planoconvexa by
the great convexity of the dorsal valves, as well as its greater size and the
prominence of the beak of the ventral valve. Length, 14 mm,
breadth, 13 mm., convexity, 8 mm.

Procluctiis Cora, Owen.

(Plate II, Fig. 26 )

Productus cora, Owen, Geol. Rep. Iowa, etc. PI. V, Fig. i. 1852.

- Pfvduchis semireticulatus,Yidi\\. Stansbury’s Rep. Salt L. 41 1. 1852.

P?'-oductus Prattenianus, Norwood. Journ. Acad. Phila. iii, 17. 1854.

Productus O’ qinco status^ Shumard. Geol. Rep. Missouri, 201. 1855.

Productus cora, Marcou. Geol. N. A. PL VI. Fig. 4. 1858.

? Productus IcEvicostus, WhitQ. Journ. Post. Soc. N. H., VII. t86o.

Productus Flemmgii^ Geinitz. Garb. -format, u. Dyas in Nebras-
ka, 52. 1866. »

Productus CalhounianiLs , Geinitz (not Swallow) do. 1866.

Productus Konnickeanus^ Geinitz, (not de Verneuil) i860..

Productus Prattenianiis^ Meek. U. S. Geol. Surv. Net. 1872.

ProductiLS Pi'attenianus White. Rep. U. S. Surv. 100 Mer.
1877. Also referred to in Ohio Geology as P. aequicostatus.

' This is the most abundant species of productus in the Carbonif-
erous of Licking county, making up almost the mass of the rock in
many places, so that slabs may be secured whose entire surface is
studded with the remains of this fossil.- Yet, from the fragile charac-
ter of the shell, it is rarely found not destroyed or broken. I trans-
cribe Shumard’s original description as a basis for the study of our
forms.

“Shell large, broad, hinge-line equal to the greatest width of the
shell. Dorsal valve much elevated, arched, visceral portion slightly
flattened on the middle, sides falling rather abruptly to the ears. Ears
large, triangular, with three or four broad folds, which are not con-

48

BULLETIN OF THE LABORATORIES

tiiiued across the visceral portion. Just within the cardinal border is
a range of four or five small tubes on either side the beak. The beak
is moderately obtuse, and passes a little beyond the cardinal border.
The surface is covered with longitudinal rounded ribs, which, at from
about one-fourth of the distance from the back, preserve nearly an
uniform width to the front margin. Some of the ribs bifurcate near
the beak, and then continue without further division, the spaces be-
tween them being occasionally supplied with new ones; they are
nearly straight on the back of the shell, on the sides they are curved
toward the lateral borders, and rendered flexuous by the folds. At
ten lines from the beak there are fifteen ribs in the space of five lines,
the whole number is from 150 to 160. The surface is studded with
slender tubes, which in some specimens are separated from each other
by pretty regular intervals, and arranged in oblique line across the
shell; in others they are scattered promiscuously over the surface.

Ventral valve concave, visceral portion nearly plane, sub-
quadrilateral, with several folds which continue across the shell ; these
are prominent on the ears and side, but become obscure as they ap-
proach the middle.

ProdlLCtuS JJUnctatuS, Martin.

(Plate II, Fig. 29. )

This is also a widely distributed species which is not very common
at Flint Ridge. Attaining a large size; shell thin, varying from sub-
quadrate to longitudinally subovate, sometimes wider than long; hinge
line always shorter than greatest width of valves ; anterior outline reg-
ularly rounded or slightly sinnous in the middle. Ventral valve gib-
bous with a merial flattening or depression extending from the front
nearly to the beak. Ears compressed, small (the specimen figured is
distorted by pressure). Dorsal valve somewhat concave, with a slight
medial prominence. Surface marked by regular, rather conspicuous,
distant, concentric ridges, supporting numerous appressed spines.
Length, 2.50, breadth, somewhat less.

•

Productus lon^ispifius , Sowerby.

(Plate II, Figs. 25, 27, 28.)

'Fhis very common and characteristic shell is one of the most

OF DENISON UNIVERSITY.

49

abundant fossils in the shales and limestones of the coal measures.
Fig 25 illustrates the structure of the interior of the valve.

Productiis inuricatus, N. and P.

Fhis form, often called a variety of the above, differs so constant-
ly from P. longispinus as to be worthy of a distinct name. It is less
common than the above and may be recognized by the fact that the
striae are much coarser than in P. longispinus, and especially by the
concentric wrinkles upon the dorsal part of the ventral valve, which
inclines to become flattened in one plane.

Productiis Jfebrascensis, Owen.

(Plate II, Fig. 30.)

This widely distributed species is recognized by the peculiar no-
dulose character of the surface, the coarse radiating striae being
crossed by irregular concentric ridges.

Productus costatus is very similar, as is P. semireticulatus.

Both last named species probably occur in these beds, but as the
specimens do not now lie at command they are not enumerated.

Chonetes inesoloha.

Although not figured, this is one of the most abundant and char-
acteristic fossils of the region and may be known by the prominent
mesial fold. Its known vertical range in the county is over one
hundred feet. A figure can be found in Dana’s Manual p. 332.

Stricklanddnia i?) suhquadrata, sp. n.

(Plate I, Pdgs. 14, 14a.)

The generic reference is simply provisional, but the figures will
illustrate the specific characters. One specimen is in the form of a
cast showing some of the internal markings; these in some respects
resemble Pentamerus. The general outline is almost exactly that of
Lingula subquadrata of the Silurian, being subquadrate with parallel
sides. The beaks are moderately prominent and the valves quite
strongly convex. The shell is marked by rather strong distant striae

50

BULLETIN OF THE LABORATORIES

parallel to the edge. The interior of the ventral (?) valve (Fig. 14)
is marked by two bifid grooves anteriorly and many pits. The largest
specimen seen measures .70 by .c;o inches.

Heinipronitcs crassus, M. and H.

(Plate II, Fig. 19. )

This common Orthis-like shell is common to the sub-carbonifer-
ous and coal measures but is much less common in the latter in Lick-
ing Co. Specimens of this species occur sparingly at Bald Hill and
Flint Ridge.

PROTOZOA

Fusulina cylindricci, Fischer.

( Plate III, Fig. 20. )

The Foraminifera are represented by one species which is obtained
from the flint-bearing limestone of Flint Ridge. In many places the
rock was almost entirely composed of these minuie shells not larger
than and nearly the shape of a grain of wheat. The shell is not pre-
served but the cavity bears the markings of the exterior which are
unmistakable. This seems to prove that the flint bearing limestone
was formed at some depth and its flint must very likely be accounted
for by supposing it to be derived from silicious protozoa and spongue
spicules. Although this species probably had a calcareous shell it
suggests that conditions prevailed suited to the growth of siliceous
forms

CORALS ETC.

A species of Zaphrentis (Plate II, Fig. 21.) is indicated by sev-
eral poorly preserved specimens but these, as well as half a dozen
species of Bryozoa, are reserved for a latter occasion. (See Ap-
pendix 11. )

In conclusion we may remind the reader that this list is of neces-
sity quite incomplete and hasty and that it has been prepared at a
distance from means of accurate comparison with types and was
designed to illustrate the richness of a single limited horizon and to

OF DFNISON UNIVERSITY.

5'

prepare the way for the intelligent study of the difficult group of rocks
below.'

In fact, a larger number of species than are here described have
been already figured from the Waverly and only a beginning is yet
made. These plates it was hoped to' print at this time but circum-
stances forbid. In the neighborhood of eighty-five species have
been collected by the class from the coal measures during a few hasty
trips to Flint Ridge. This is as many as have been described
from the coal measures of Indiana. Meek, in the Ohio Paleontology
describes only about twenty.

APPENDIX L CARBONIFEROUS TRILOBITES.

P was intended to devote space to a somewhat extended discus-
sion of the carboniferous Trilobites of America but lack of space and
the incompleteness of the discussion possible at present has induced
us to give up the idea, especially in view of the hint that a special
work is soon to appear upon this subject. The following notes are,
however, appended to the present paper in the hope that they may
prove useful.

It is well known that during the carboniferous period trilobites
rapidly approach extinction and but few remained to struggle with the
adverse conditions of the Permican. But why the seas of the car-
boniferous were less favorable than those of the Cambrian and Silurian
remains a mystery. Although the trilobite of the early Palaeozoic was,
perhaps, a synthetic type as argued by Agassiz, it would seem that the
trilobites of the carboniferous belonged to a closed type with slight
powers of adaption.

A careful study of the trilobites of the carboniferous rocks of
America ought to throw some light on the5e matters if undertaken in
a truly comparative spijit rather than from the standpoint of the mere
systematist. Nevertheless it is necessary to first devote the requisite
systematic study in order to give critical value to determinations^ A
review of the whole field is necessary, but its difficulty has been much
lightened by the works of two European authors from which many of
our statements are drawn. ( Valerian v. Moeller. Ueber die
Trilobiten der steinkohlen formation des Ural, nebst einer Uebersicht
und einegen Ergaenzungen der bisherigen Beobachtungen ueber
Kohlen Trilobiten, 1867; H. Woodwai^d. A Monograph of the

52

BULLETIN OF THE LABORATORIES

British Carboniferous 'brilobites 18S3-81 Palaeontographical Society,
London. )

The first description of trilobite remains from carboniferous rocks
was that of the Abbe' de Vitry in 1779. (3 Mem. de I’Acad. imper.

et royale des sciences et belles lettres de Bruxelles, 1780.) Thirty
years later William Martin described in his Petrihcata Derbiensia a
toilobite as Entomolithus onicites Derbyensis, which he regarded as a
petrified insect related to Oniscus.

In 1836, Phillips’ Geology of Yorkshire appeared, in which eight
species were described, albeit very imperfectly.

Portlock, in 1843, published his Geological Report on London-
derry in which for the first time the attempt was made to set up distinct
genera for the carboniferous trilobites. Phillipsia .2iX\d GfiffithideSy
the two prominent genera, date from this report.

De Koninck added much to the general fund of information,
although his studies were restricted to Belgium.

M’Coy’s Synopsis of the characters of the carboniferous Lime-
stone Fossils added several species although none too well distinguished.

Family Proei'id/e.

The four genera, Phillipsia, Griffithides, Brachymetopus, and
Proetus, which constitute the family are all found in carboniferous
rocks, while the first three are restricted to it, and Proetus begins in
the Silurian. Phillipsia ‘and Griffiides really constitute one genus with
two types more or less closely united. In both, the general form is
oval, the angles of the cheeks may be greatly produced, facial suture
cutting obliquity across the posterior margin of the head-shield ;
thoracic segments nine in number ; pigidium with 12-18 segments,
margin rounded, not fimbriated.

Genus i. Phillipsia, Portlock, 1843.

Glabella with nearly parallel sides ; basal lobes, formed by a well
defined furrow separating the posterior corners, distinct ; middle of
glabella marked by two or more lateral furrows ; eyes large, facetted ;
cervical furrow deep.

Genus 2. Griffithides, Portlock, 1843.

Glabella, pyriforme, tumid, destitute of lateral furrows, eyes
small smooth, cervical lobe broad.

OF DENISON UNIVERSriY.

53.

Genus 3. Proetus, Steininger, 1830.

General form oval, head short, pigidiiim longer ; head-shield with
a raised border and furrow ; angle of free cheeks sometimes pro-
duced ; basal lobes of glabella distinct, with or without lateral fur-
rows ; axial furrows distinct, facial suture diverging in front of eyes to
form prominent palpebral lobes. Free thoracic segments 8-10.
Pigidium with elevated axis, plurse falling short of margin of the
pigidium, which usually is smooth.

Genus 4. Brachymeiopus, M’Coy, 1847.

Head shield nearly semicircular, acutish in front, one-third wider
than long; glabella small, about one-half length of head, with basal,
but no lateral lobes ; facial suture obscure.; angles of cheeks produced;
surface pustulate ; pigidum with a rounded border, ribs with double
furrows, surface ornamented.

The following list embraces all the now recognized species of car-
boniferous trilobites, so far as can be ascertained. It must be admit-
ted that many species have been described in this country from frag-
ments too imperfect or too incomplete to afford adequate means of
comparison.

Genus Dalmanites (?)

I. D. cuyahogce^ Claypole, (Plate II, Fig. 33.)

Genus Proetes.

1. P. laevis, Woodward.

2. P. auriculatis^ Hall.

3- P. ellipticus, Meek and Worthen.

Genus Phillipsia.

European Species.

Known from heads and pigidia.

A. Angle of free cheek produced to form a long spine.

I. Axial lobe of glabella not expanded in front.

I. P. gemmulifera^ Phillips. Two lateral furrows on the glabella,
axis of pigidium, with about 18 somites. (Plate VI, 6.)

3. P. triincatula, Phillips. Three lateral furrows on glabella,,
axis of pigidium, wirh about r8 somites. (Plate VI, 7.)

54

BULLETIN OF THE LABORATORIES

IL Axial lobe of glabella expanded anteriorly.

(a) of medium size.

f. pigidium rather longer than wide.

3. F. eichwaldi^ Fischer. Head nearly semi-circular, eyes large.
3a. P. eichwaldt^ var. 7nucronata, McCoy. Pigidium, with a me-
dian posterior prominence. (Plate VI, 8.)

4. P. leei^ Woodward. Eyes very small.

X. pigidium broader than long.

5. S. cliffordi^ Woodward. Pigidium twice as wide as long.

(b) . Of small size.

6. P. minor ^ Woodward.

B. Angle of free cheeks not produced to form a conspicuous
spine.

I. Anterior margin of glabella not expanded.

7. P. derbiensis, Martin, (Plate VI, Fig. 12.)

II. Anterior margin of glabella expanded.

a. Pigidium wider than long.

8. P. colei^ McCoy, (Plate VI, Fig. ii.)

b. Pigidium longer than wide.

9. P. scabra, Woodward.

Known only from pigidia.

10. P. articulosa^ Woodward. Resembles P. cliffordi, differing
in having seventeen coalesced somites instead of thirteen. -

11. P carinata^ Salter. Axis of the tail acutely ridged, seven-
teen segments.

12. P. laticaiidata, Woodward. Pigidium very wide, with
twelve somites, axis elevated.

American Species.

Known from both heads and pigidia.

.1. P. swallovi, Shumard.

, 2. P. shumardi\ Herrick.

, 3. P. sagainonensis , Meek and Worthen.

« 4. P. scitula^ Meek and Worthen.

. 5. doris, Winchell.

'6. P. rockfordensis, Winchell.

» 7. P. insignis^ Winchell.

8. P. irimuleata, Herrick.

OF DENISON UNIVERSITY.

5

Known from pigidia or glabellse only.

. 9. P. meramecensis ^ Shumard.
f 10. P. missouriensis , Shumard.

<11. P. major, Shumard.

.12. P. cliftonensis, Shumard.

(?)i3. P. stevensoni, Meek.

14. P. peraniilata, Shumard.

(?)i5. P. latispinosa, Sandberger.

(?)i6. P. tennesseensis, Winchell.

Genus Griffithides.

1. G. acanthiceps, Woodward, (Plate VI, Fig. 10.)

2. G. brevispiniLs , Woodward.

3. G. calcar atus, McCoy, (Plate VI, Fig. 16.*)

[^Figure omitted in plate, it lies above and between ii and 12.]
(?)4. G, carringtonensis, Etheridge.

5. G. glaber. Woodward.

6. G. globiceps, Phillips.

7. G. longispiniLs , Portlock.

8. G. moriceps, Woodward.

9. G. obsoleius, Phillips.

10. G. platyceps, Portlock.

11. G. seminiferus, Phhillips.

12. G. roemeri, Moeller.

13. G. gruenewaldti, Moeller.

14. G. btifo, Meek and Worthen.

15. G. portlocki, Meek and Worthen.

16. G. longiceps, Portlock.

Genus Brachymetopus.

1. B. discors, McCoy.

2. B. hibernicus, Woodward.

3. B. McCoyi, Portlock, (Plate VI, Fig. 16.)

4. B. oiLralicus, McCoy, (Plate VI, Fig. 14.)

(?)5. B. lodiensis, Meek, (Plate III, Fig. 4.)

Annotations on the above list.

Dalmanites ? cnyahogce Claypole was described in the Geol. Mag,

56

BULLETIN OF THE LABORATORIES

Decade iii, vol. i, p. 306, 1883. The specimen described was a near-
ly entire pigidium, differing from all known carboniferous species in
the long spinous processes, which resemble those of Dalmanites.

It might be observed that the great size of the median lobe is sug-
gestive that possibly the marginal part of the pigidium had been some-
how removed, leaving the ribs irregularly preserved. The pigidium
might then belong to Brachymetopus^ but such a mutilation would most
assuredly have been noticed by Prof. Claypole.

The specimens referred to Proetus consist of pigidia and frag-
ments and the reference is based on analogy simply.

Of the species of Phulipsia figured, it is not necessary to give
descriptions, while condensed descriptions of the others, as far as they
can now be drawn up, are given.

The various authorities who have described P. cequalis ( — P. pos-
thumus,) disagree even in essential characteristics, so that for the pres-
ent its position must remain doubtful.

P. articidosa is closely related to P. clijfoi'di^ from which it differs
in the greater number of coalesced somites.

“ Pigidium [the only part known] one-fourth broader than long,
axis one-third breadth, consisting of seventeen coalesced segments,
which diminish rapidly in breadth to the extremity, which is bluntly
round, and less than one third the breadth of the axis at the proximal
end; axial furrows deeply marked. Plurse 13, terminating abruptly
within the margin, which is finely striated, unornamented.”

P. carinata^ is too imperfect in the specimens as yet discovered
to be worthy of description.

P. cliffordi. Pigidium twice as long as broad, axis one-third the
breadth at proximal border, rapidly diminishing to one-seventh ; the
border is posteriorly one-seventh the length of the pigidium, but di-
minishes laterally; axis of 13 somites, with 10 lateral plurse, which
bifurcate as they approach the margin, unornamented.

P. laticaudata. Pigidium much broader than long, very strongly
trilobed; axis elevated, consisting of 12 somites; each strongly ridged
and ornamented with a series of minute tubercles. Plurse 9, broad
for half their length, minutely ornamented, losing themselves near
margin ; length 6 mm., breadth 9 mm. Glabella tumid, imperfect.

Our restoration of the head of P. leei is from badly distorted
specimens and hence may not be accurate in every particular. The
The pigidium is one-fifth broader than long, the axis forms one-third

OF DENISON UNIVERSITY.

57

of its breadth at the proximal border, but diminishes very rapidly, ter-
minating in a somewhat blunt point near the posterior margin, About
14 somites, with about 9 plurae, surrounded by a narrow, smooth bor-
der. The pigidium is more triangular that of P. colei.

P. minor is a very small species, having a pigidium resembling
that of P. eichwaldi. Head shield rounded in front, one-third broader
than long; glabella occupying one-third breadth, oval, slightly broader
in front, tumid, with distinctly marked basal lobes; lateral furrow in-
distinct ; neck-lobe rather prominent ; angle of cheek produced into a
short slightly curved spine.

P. qiiadrilimha is too imperfectly described to be recognized and
might better be dropped from synonomy.

Griffithides brevispiims is known only from two fragments of the
head. The author describes as follows :

“ Head nearly twice as broad as long ; free cheek, terminating
laterally in a short spine ; the eye, which is very smooth, is rounder
and more tumid than ‘in other species. The glabella is nearly smooth
in front, and overhangs the anterior border of head-shield ; posterior
portion of the glabella and the neck-lobe irregularly tuberculated ; free
cheek also tuberculated, about 8 tubercles on each cheek, placed in a
semicircle about the eyes. Margin of shield. raised and striated.”

G. I carringtqnensis is represented by pigidia resembling very
much that of G. obsoletus, except that this species has 12 axial seg-
ments and has a distinct margin to the pigidium, while G. obsoleius has
but 10 segments.

G. obsoleius. Pigidium one-fourth broader than long, composed
of 10 segments, oxis much broader than plural portion ; each of the
9 rib-like plicae marked by a furrow down the centre, margin smooth.
Glabella covered with peculiar striations.

G. plaiyceps was described from a fragmentary glabella, only and
is not recognizable.

The two species of Bi'achymetopus., B. discors and B. hibernicus
are founded on pigidia only and the outline drawings given will afford
all the information we possess concerning them.

Meek’s Pliilllpsia lodiensis., if a Brachymetopus, is the only mem-
ber of this genus yet found in America.

We have thus hastily reviewed the exotic species and turn to a
more careful study of the American forms. In the first place, let us
examine the original descriptions.

BULLETIN OF THE LABORATORIES

58

Genus Phillipsia.

Phillipsia SWallovi, Shumard.

Froetus swallovi, Shumard. Geol. Surv. Missouri.

“Head semi-circular, swollen, exterior border narrow, slightly
elevated and marked with 4 or 5 thread-like striae ; sinus of the border
shallow and indistinct ; posterior border of cheeks rather wide, and
limted internally by a shallow, but distinct groove ; genal angle
short and round?; glabella tumid, elevated above the plane of the
cheeks ; occupying about four-fifths the entire length of head, rather
more than half as wide as long ; front rounded ; sides convex in ad-
vance of the eyes ; slightly concave in the middle, and expanding
again posteriorly ; lobation indistinctly marked by three very shallow
depressions on each side, the anterior and middle ones being nearly
obsolete ; occipital segment wider than the base of the glabella ; occip-
ital furrow slightly arched toward the front, narrow, rather deeply im-
pressed, widest at the extremities; the furrow which separates the gla-
bella from the cheeks [facial suture] is narrow, flexuous and slightly
impressed ; palpebraral lobes semi-oval, visual surfaces minutely retic-
ulated. Thorax with 9 segments ; axial lobe elevated, width greater
than lateral lobes [pleural portions], rings rather wide, flattened in the
direction of the axis ; pigidium parabolic, moderately convex ; length
about equal to head; border rather wide; axial lobe elevated, as wide
as lateral lobes; segments eleven, lateral lobes about seven, indistinct.
Whole surface minutely punctuate; the punctures sometimes disposed
in quincunx, and sometimes irregularly. Length of head, 3^ lines;
greatest width, 6 lines.”

The species is described from the Ghemung, at Chouteau Springs,
Cooper Co., Missouri, but it is suspected that the formation will be
found to be really sub-carboniferous.

Phillipsia shumardi, Hen-ick.

Proetus niissouriensis^ Shum., Geol. Surv. Missouri.

Glabella tumid, greatest height about the centre, ovoid, obtusely
rounded in front, truncated posteriorly, length a little greater than width,
widest behind, three furrows on either side; posterior pair strongly
marked, these commence at the dorsal sinus about one-third from
base to front, pass in a curve backward, and bifurcate about midway
between the sides and middle of the glabella, one branch very shallow,

OF DENISON UNIVERSITY.

59

is continued for a short distance almost transversely, the other bends
back nearly to occipital sinus and, with the main branch, partially
encloses a large oval lobe on either side, the lobes [basal lobes] sep-
arated by a space about one-half width of glabella ; middle pair of
furrows shallow, curving backwards in a direction nearly parallel with
the posterior ones, but considerably shorter, anterior pair feebly im-
pressed, a little oblique ; occipital sinus a little convex toward the
front, shallowest in the middle ; occipital ring [neck-lobe] wide,
flattened, much lower than the plane of glabella. Pigidium semi-
circular, flattened convex, width double the length, margin broad and
slightly concave; axial lobe almost as wide as the lateral lobes,
rounded at the extremity, segments lo, separated by well-marked
furrows ; surface thickly studded with granulse, which are rather smaller
than those of the glabella. Length of head, 8^ lines; greatest width,
7^ lines; length of pigidium, 6^ lines; width i inch.

This species is also described from the Lithographic limestone
said to be of Chemung age, but it occurs to in the VVaverly (sub-
carboniferous) of Ohio, at Granville. As this species is certainly a
Phillipsia the name was preoccupied by Phillipsia 7nissoiLriensis,
Shumard, from Middle Coal Measures at Lexington, Mo., described
in 1858, Trans. Acad. Sci., St. Louis.

Phillipsia meramecensis , Shumard.

Pigidium [only portion known] semi-elliptical, rather wider than
long, very convex; 'border moderately narrow; axial lobe not quite as
wide as the lateral lobes, and considerably elevated above them; an-
terior extremity arched ; posterior extremity obtusely rounded ; rings
13. convex on the dorsum, but shallow and narrow on the flattened
sides; lateral lobes strongly arched downward; ribs about 12, indistinct,
except the last two or three ; the first four from the thoracic margin
marked by a shallow, but distinct furrow, which is situated very near
the posterior edge ; furrows between the ribs rather deeply impressed.
Surface very finely granulose. Length, six lines ; width, 6}4, lines.”

Described from the so-called Archimedes limestone, in St. Louis
Co., Mo. There is nothing characteristic about the pigidium de-
scribed, though it may be readily distinguished from the previous one.

Phillipsia inissouriensis , Shumard.

Pigidium semi-elliptical, elevated, width greater than length ; sur-

6o

BULLETIN OF THE LABORATORIES

face very finely punctate, punctse rather distant and arranged some-
what in quincunx ; margin rather broad and smooth ; axial lobe strongly
arched transversely, gradually tapering, forming not quite four-fifths
the total length ; its width equal to about three-fourths the width of
lateral lobe; rings about i8, rounded on the dorsum and flattened at
die extremities, transverse furrow narrow, distinctly impressed on the
dorsum, becoming obsolete before reaching the longitudinal furrows ;
lateral lobes rather strongly arched transversely ; anterior margin an-
gulated, apex of angle elevated and situated nearest the axial lobe ;
segments eleven, rounded, curving slightly downwards, not furrowed;
furrows between the segments rather deeply impressed, except the two
posterior ones, which are quite shallow. Length, .68; width, .76;
length of axial lobe, .56; width, .23.

Such a description of a pigidium simply can have but a local
value.

PJliUipsici major, Shumard.

Pigidium [only part known] large, elevated, approaching to semi-
elliptical, a little wider than long; surface smooth, or very finely
punctuate; outline of edges sinuate, margin broad, particularly to-
ward the posterior extremity ; axial lobe very much elevated, gently
tapering, forming five-sixths of the total length, not so wide as the lat-
eral lobe, rather strongly arched longitudinally, sides with a broad,
shallow groove running their whole length ; rings 23, very strongly
arched from side to side to side, angulated in the lateral depressions
and their extremities directed obliquely backward. The first 6 or 7
from the front are very flat in a longitudinal direction, and are sepa-
rated from each other by fine, scarcely impressed, transverse lines or
furrows. Posterior to these the furrows are distinctly impressed to the
extremity of the lobe, while the rings become gradually more rounded
on the dorsum, but on the sides they still continue flattened. Lateral
lobes moderately convex, obtusely angulated in front ; segments 12,
rounded, slightly sinuate, simple; furrows rather strongly impressed,
except the two last, which are nearly obsolete. Width, 1.20 in.;
length, T.io; length of axial lobe, .93; width at anterior extremity, .30.

This very large species has several peculiarities which may make
it possible to recognize it from the description. It is said to have been
derived from the upper coal measures in Kansas.

Meek was apparently in error in identifying the specimens figured

OF DENISON UNIVERSITY.

6i

in his Paleontology of Nebraska, with Shumard’s P. major. The for-
mer are characterized by a rather unusual length of pigidia, while those
of the latter are broad. The pigidium Fig. i, Plate II, of the Nebras-
ka report closely resembles Grififithides obsoletus.

Phillipsia cliftonensis , Shumard.

Pigidium small, semi-elliptical, gibbous, width greater than the
length; axial lobe elevated longitudinally, gently arched, dorsum
slightly depressed, width at forward extremity about equal to one lat-
eral lobe exclusive of smooth margin, gradually tapering and termi-
nating in a blunt point posteriorly; rings from 13 to 14, sub-granulose,
separated by distinctly impressed furrows ; lateral lobes angulated near
the middle, flattened above and on the sides, well defined from the
margin by a shallow, but distinct furrow; segments 7, rounded, sepa-
rated by distinct linear sulci ; margin moderately wide and regularly
convex. Length, .23; width, .25 ; heigt, .11 ; height of axial lobe,
.04; length, .19.

This is also from the upper coal measures of Kansas.

Phillipsia san£am01'isis . Meek and Worthen. ^

(Plate V, Fig. 13.)

Sub-ovate ; cephalic shield convex, regularly rounded in front,
cheeks produced into carinated processes less than one-third entire
median length ef head; glabella convex, sub-inflated, axial suture
moderately well defined, greatest convexity behind the middle, length

width, sides nearly parallel ; posterior lobes large, prominent ; sec-
ond lateral furrow curved, oblique, anterior furrows nearly obsolete ;
cervical segment and suture well defined; facial suture quite well de-
fined, intersecting posterior margin midway to angle. Eyes rather
large, half as long as glabella, exclusive of cervical segment, promi-
nent ; palpebral lobes convex, resting upon the eye like a lid.

Pigidium semi-elliptical, rather convex, a little wider than long,
narrow and rather longer than head, narrowing posteriorly, abruptly
rounded behind; mesial lobe prominent, a little flattened at each side,
narrower than the lateral lobes, from which it is separated by a broad
furrow, about two-thirds entire length of glabella ; lateral lobes less
prominent, abruptly convex at outer side ; segments 9 or 10, all termi-
nating abruptly at the edge of a broad marginal zone, which is widest

62

BULLETIN OF THE LABORATORIES

posteriorly; surface smooth. Length of head, medianly, .50;
breadth, .65 ; length of glabella, .35; width, .30.

This species is said to be rather common in the Western states,
but It has not yet been secured from Ohio.

Phillipsich scitulci, Meek and Wovthen.

Elliptical ; head semi-elliptical, tumid, one-third wider than long,
anterior margin rounded, cheeks produced into spines extending to
fifth thoracic segment ; glabella broadly rounded, occupying the mar-
gin in front, most elevated posteriorly, axial sutures obsolete anterior-
ly, posterior lateral lobes rather large, very oblique, lateral lobes al-
most obsolete ; cervical segment more prominent than the glabella,
with a median tubercle, cervical suture deep ; eyes one-half as long
as the glabella; palpebral lobes semi-circular, convex; cheeks small ;
pigidium almost as long as head, narrower, mesial lobe prominent,
wider than lateral lobes, border wide ; surface granular. Entire length,
.70; pigidium, .20; width of pigidium, .30; length of head, .25;
width, .31.

Judging from the figures and descriptions this species is the near-
est approach to Grifhthides yet found in America. The presence of
lateral furrows on the glabella indicate a member of Phillipsia, how-
ever, as the genera are now understoood.

Phillipsia doris, (Hall) Winchell.

Head surrounded by an outwardly inclined border marked off by
a deep groove from the cheeks, which are produced into spines poste-
riorly one-third whole length of head shield; glabella prolatel}/ semi-
elliptical, with large postero-lateral lobes, the lateral furrows indistinct;
pigidium semi-elliptical, axial portion convex, diminishing to an obtuse
point ; lateral lobes somewhat narrower, bordered by a smooth margi-
nal area, axis with 1 1 articulations, lateral lobe 7 ; surface obscurely
granulose,

Winchell says, also “ middle of the border (of head) marked by
a groove which reaches a point opposite one eye, to the corresponding
point on the other side of the head,” which seems somewhat difficult
to understand. The species was obtained from Rockford, Indiana.
Width of pigidium, .55; length, ,21.

Phillipsia rochfordensis, Winchell.

“ Cephalic shield surrounded by a narrow, convex border, which

OF DENISON UNIVERSITY.

63

is bounded internally by a narrow, but deep groove, and terminates
posteriorly in conically tapering genal points. The principal lobe of
the glabella is relatively very large, convex, highest in the middle,
widened anteriorly, circularly rounded in front, and gently curved on
the sides ; no glabellar furrows are present. The complimentary [pos-
tero lateral] lobes are large, oval, and project laterally farther than the
main lobe. The surface of glabella finely, but sharply granulated ;
margin finely striated. Size about as that of P. doris. Collected at
Rockford, Indiana.”

P. msignis, Winchell, is closely allied to P. meramecensis, Shumard.
Not having access to the original description I can only gather that
the head is armed with spines which reach twice the length of the
glabella from the anterior end,” and the eyes are large, while the pi-
gidium has a plane margin.

P. howi, was described by Mr. Billings. It is said to be closely
allied to the above, but has a greater number of annuli in the axis of
the pigidium, which alone is known.

P. vindobonensis, Hartt, is described as follows :

“Pigidium semi-elliptical, very convex; (one or two segments
appear to be wanting from the anterior margin of the only specimen
seen,) but its width must have been greater than its length. Ten or
eleven articulations are visible on the side lobes and twelve of the axis,
which is very prominent and moderately tapering. The axial rings
are depressed, convex, becoming smaller, more crowded, and more
distant toward the apex. Ribs on the side lobes depressed, convex,
decreasing in length, breadth and distinctness from before backward,
while at the same time they become more and more inclined backward.
The six anterior ribs preserved show a distinctly marked groove, origi-
nating on the posterior margin at about one-third the length of the rib
from the axis, and running obliquely, increasing in depth to the end
of the rib. Smooth border none, or extremely narrow at the anterior
angles, but becoming three-fifths the width of the axis near the poste-
rior part of the pigidium, which is not visible in the only specimen I
have examined.”

We have here, therefore, a species described from a fragment of
a pigidium, exhibiting neither end and nothing else of importance,
an. example of puerility too often followed.

64

BULLETIN OF THE LABORATORIES

Phillipsla, triniicleata, n- sp.

A considerable number of specimens have been collected which
were at first supposed to be P. sangamo7ieiisis, but are evidently quite
distinct from any described species. It is not absolutely certain that
the cheek spine belongs to the same species as the glabella and pigidia
with which it was associated, yet the circumstances render it highly
probable.

The glabella presents the most distinctive features. It is considera-
bly longer than wide and quite convex, the greatest height being poste-
rior to the middle. An^-erior depressed margin rather narrow in front,
expanded laterally; sides nearly straight' or somewhat concave near
the eyes ; postero-lateral lobes very sharply defined, conical, oblique,
with a second smaller pair in front of them, and a very faintly out-
lined second pair still farther forward ; between the postero-lateral
lobes a sharply defined, prominent, median elevation, almost as large
as the others; cervical segment convex, high, often with a single me-
dian tubercle. The surface of the glabella is minutely ornamented
and on either side in front of the eyes is an oval pit which has been
thought by some to represent the insertion of the antenna or organ of
sense.

The eyes are large and supported by a prominent palpebraral
lobe. A single movable cheek has been found. The margin is ob-
liquely inclined, forming a prominent angle at its union with the face;
middle of cheek depressed and marked with an impressed line ; cheek
produced into a spine as long as the whole remainder of the cheek ;
length of cheek, .77 (the spine, .35); length of eye, .11. Pigidia are
not rare and are very convex, the median lobe especially being con-
vex from side to side and particularly prominent posteriorly. The
median lobe occupies one-third or less the wddth of the pigidium prox-
imally and tapers gradually, forming a portion of a regular truncate
cone ; on either side an impressed line marking off an accessory por-
tion; axial segments 17-19; lateral lobes convex; plurae flattened
slightly above, separated by very deep sutures; margin broad, longi-
tudinally striate, abruptly deflexed ; ribs 9-12. Length of pigidiuiTi,
.35 ; width, .45, length of axial lobe, . 27. Another individual, length,
.48, width, .56, axial lobe, width, .20, length, 40. The pigidium is
generally, if not always ornamented by minute pistules on the summits
of the segments which are borne on the top of a slightly elevated, flat-
tened ridge forming the axis of the annuli.

OF DENISON UNIVERSITY.

65

PLATE I. '

(Figures, unless otherwise indicated, natural size.)

Fig. I. Entolium aviculatum. Swallow^ left valve.

Pdg. 2. Right valve of the same — p. 23.

Fig. 3. Aviculopecten ?

Fig. 4. Aviculopecten coxanus, M. and W.

Fig. 5. Aviculopecten hertzeri, Meek^ or related species — p. 25.
Fig. 6. Aviculopecten sp? — p. 27.

Fig. 8. Aviculopecten scalaris, — p. 26.

Fig. 9.

Fig. 10. Aviculopecten hertzeri. Meek — p. 25.

Lig. II. Entolium attenuatum, He^'rick — p. 24.

Fig. 13. Martinia ])lanoconvexa, Sch — p. 46.

Fig. 13. a, b, c. Martinia lineata, Martin — p. 46.

Fig. 14. Stricklandia ? subquadrata, Herrick — p. 49.

Fig. 16. a, b, c. Athyris subtilita ?? — cf. Pal. Neb. Plate I,
Fig. 12.

Fig. 17. Aviculopecten coxanus, M. and W. — p. 26.

Fig. 18. Athyris subtilita, Hall — p. 44.

Fig. 19. Solen sp. — p. 38.

Fig. 20. Aviculopinna americana. Meek — p. 38.

Fig. 21. Ostracode crustacean ? a single valve.

Fig. 22. Allorisma sp?

Fig. 23. Phillipsia trinucleata, Herrick.

Fig. 24. Productus sp. Small individual.

PLATE II.

Fig. I. Bellerophon montfortianus, N. and P. — p. 19.

Fig. 2. Macrocheilus planus? — p. 3i.

Fig. 3-

Fig. 4 and 5. Euomphalus sp. — p. 22.

Fig. 6. Spirifer sp.

Fig. 7. Bellerophon SLibcordiformis, Herrick— iS.

Fig. 8. Discina Meekana, Whitfield., with shell partly preserved.

Fig. 9. Under valve of same?

Fig. 10. Orbiculoidea ? sp. Incorrectly drawn, the outline is not
circular, but somewhat elliptical. Very likely the same species figured

66

BULLETIN OF THE LABORATORIES

but not named by Meek, in Paleontology of Nebraska, Plate IV, Fig. 3.
Figs, II and 13. Pleiirotomaria sp.

Fig. 12. Bellerophon decussatus, Fleming? 19.

Fig., 14. Bellerophon percarinatus. Con. — p. 17.

Fig. 15. Polyphemopsis inornata, M. and W. — p. 20.

Fig. 16. Macrocheilus medialis, M. and W. — p. 21.

Fig. 17. Nautilus sp. — p. 17.

Fig. 18. Pleurotomaria newportensis, White— 21.

Fig. 19. Hemiphronites crassus, M. and H. — p. 50.

— Fig. 30. Bellerophon carbonarius, C^'A:—p. 10.

Fig. 21. Zaphrentis, sp.

Fig. 22. Spirifer camerata, Mo^'ton — p. 45.

Fig. 23. Spirifer opima,Z/7i2// — p. 44.

Fig. 24. Spirifer striata ?

Figs. 25, 27, 28. Productus longispinus, Sowenby — p. 48.

Fig. 26. Productus cora, Owen — p. 47.

Fig. 29. Productus punctatus, Martin — p. 48.

Fig. 30. Productus nebrascensis. Owen — p. 49.

Fig. 31. Productus sp.

Fig. 32. Phillipsia trinucleata, Herrick, decorticated glabella.

Fig. 33. Dalmauites? cuyahogae, Claypole, pigidium.

Fig. 34. Unidentified gasteropod.

PLATE III.

Fig. I. Macrocheilus sp?

Fig. 2. Loxonema sp.

Fig. 3. Bellerophon nodocarinatus. Hall — p. 18.

Fig. 4. Brachymetopsus lodiensis. Meek.

Fig. 5. Griffithides glaber, Wotdw. — restored.

Fig. 6. Phillipsia scabra, Woodw.

Fig. 7. Allorisma costata, M. a7id W. — p. 33.

Fig. 8. Solenomya subradiata, Her7ick — p. 30.

Fig. 9. Crenipecten foerstii, Herrick, both valves of the same shell.
Fig. 9a. (near the centre of the plate) cast of same with impres-
sion of hinge line.

Fig. 10. Outline of Entolium aviculatum as found at Flint Ridge.
Two valves in position, showing supposed relation.

Fig. II. Clinopistha radiata, Hall — p. 34.

Fig. 12. Gervillia (Avicula) ohioense, Herrick — p. 36.

OF DENISON UNIVERSITY.

67

Fig. 13. Aviculopecten carboniferus. (Accidentally omitted from
the list.)

' Fig. 14. Schizodus (?) spellmani, Herrick — p. 42.

^ Fig. 15. Schizodus wheeleri, Swallow — p. 42.

Fig. 16. Aviculopecten sorer, Herrick — p. 27.

Fig. 17. Edmondia sp ? — p. 38.

Fig. 18. Aviculopecten? — p. 25.

Fig. 1 9. Discina convexa, Shzim, {?) Omitted from list.

Fig. 20. Aviculopecten sp? — above No. 19.

Fig. 21. Phillipsia trinucleata, Herrick.

PLATE IV.

\

Fig. I, 2. Allorisma subcuneata, M. and H. — p. 35.
Figr 3. Prothyris elegans, Meek — p. 38.

Fig. 6. Myalina swallovi, McChesney — p. 37.

Fig. 7.

Fig. 8.

Fig. 9. Solenomya ? meekana, Herrick — p. 30.

Fig. 10. Solenomya anodontoides, Meek — p. 29.

Fig. II. Placunopsis recticardinalis, Meek — p 43.

Fig. 12. Myalina?

Fig. 13. Gervillia (Avicula) ohioense, Herrick — p. 36.
Fig. 14. Macrodon carbonaria, Cox I — p. 32.

Fig. 15. Pleurophorus tropidophorus, Meek — p. 35.
Fig. 16. Pleurophorus subcostatus, M. and W. — p. 35.
Figs. 17, 18. Cypricardina carbonaria. Meek — p. 35.
Fig. 19. Macrodon obsoletus. Meek — p. 31.

Fig. 20. Myalina sp.

Fig. 21. Macrodon carbonaria, Cox — p. 32.

Fig. 22. Schizodus affinis, Herrick.

Fig. 23. Schizodus cuneatus, Meek?---p. 32.

Fig. 24. Schizodus subcircularis, Herrick.

Fig. 35. Lima retifera, Shumard — p. 29.

Fig. 26. Nuculana bellistriata, Stevens — p. 40.

Fig. 27. Allorisma geinitzi. Meek — p. 53,

Fig, 28. Allorisma costata, M. and W. — p. 33.

3°' (Specimen mislaid.)

Fig. 31. Astartella varica, McChesney — p. 39,

Fig. 32. Microdon subelliptica. Hall — p. 40.

Fig. 33. Astartella newberryi. Meek — p. 30.

Fig. 34. Unidentified.

68

BULLETIN OF THE LABORATORIES

PLATE V.

Fig. I. Allorisma ?

Fig. 2. Orthoceras cribrosum, Geinitz — p. 17.

Fig. 3. Lima retifera, Shimiard — p. 29.

Fig. 4. Myalina subquadrata ? (cf. M. recurvirostra.)

Fig. 5. Euomphaliis sp — p. 22.

Fig. 6. Bellerophon crassus, M. and IV.— p. 22.

Fig. 7. Bellerophon marcoiiianiis, Geinitz — p. 20.

Fig. 8. Bellerophon montfortianus, N. and P. — p. 19.

Figs. 9 and ro. Oudines of large plates, apparently part of head
armor of fishes, one-half natural size.

Fig. II. Phillipsia swallovi, Shumard.

Fig. 12. Phillipsia leei, Woodw.

Fig. 13. Phillipsia sangamonensis, M. and IV head.

PLATE VI.

Fig. I. Griffithides globiceps, Phillips.

Fig. 2. Griffithides longispinus, Portlock.

Fig. 3. Griffithides longisceps, Portlock.

Fig. 4. . Griffithides seminiferus, Phillips.

Fig. 5. Griffithides moriceps, Woodward.

Fig. 6. Phillipsia gemmulifera, Phillips.

Fig. 7. Phillipsia truncatula, Phillips.

Fig. 8. Phillipsia eichwaldi, var. mucronata, McCoy.

Fig. 10. Griffithides acanthiceps. Woodward.

Fig. II. Phillipsia colei, McCoy., iia, hypostome.

Fig. 12. Phillipsia derbiensis,

Fig. 13. Griffithides roemeri, Moeller.

Fig. 14. Brachymetopus oiiralicus, De Vetneall.

Fig. 15. Griffithides gruenewaldti, Moeller.

Fig. 16. Brachymetopus maccoyi, Portlock.

Fig. 17. Griffithides calcaratus, McCoy.

These figures are mostly reduced from Woodward’s monograph,
with slight modifications.

APPENDIX II. A Waverly Trilobite.

Since the preceding synopsis of Trilobites was put in type, a fine
specimen of Phillipsia shumardi, (missouriensis, Shumard, ) was found
in the Waverly, south of Granville, by W. F. Cooper, which makes it
possible for us to complete the description quoted on page 58, and to
correct a few minor inaccuracies. This identification, which can
hardly be open to the slightest question, will throw additional light on
the position of the Lithographic limestone of Missouri.

Phillipsia shumardi, Herrick.

( Plate VII, Fig. 14. )

Proetiis missouriensis, Shum., Geol. Surv. Missouri, p. 196. (See

ante, p. 58.)

The description following is based upon an entire and nearly per-
fect specimen from the Waverly freestone at Granville, O.;

General form elongate, oblong elliptical, axial portions strongly
elevated ; outline of head somewhat parabolic, nearly twice as broad
as axial length. Head shield very high axially, the height of the gla-
bella being considerably more than one-fourth the entire width of the
head shield ; cheeks produced into spines reaching about to the third
thoracic segment. The glabella is short and broadly rounded anteri-
orly, margin in front thickened to form a high mural ridge or lip sepa-
rated from the prominent frontal portion by a deep sulcus ; axial por-
tion about one-third as wide as the entire head shield and scarcely ex-
panded anteriorly, marked by three lateral sulci. The basal (postero-
lateral) lobes are large and oblique, separated by an interval equalling
about half the width of glabella. The sulcus anterior to the lobes has
a slight tendency to bifurcate and the two in front of it are faint and
less oblique. The palpebral lobes are very large. The cervical
groove is deep and abrupt and the cervical segment does not rise to
the level of the median axial portion. The cheeks are extensive and
decline greatly to a submarginal groove. The spine is of moderate

BULLETIN OF THE LABORATORIES

70

length and the margin is greatly rounded and exhibits (sub-epidermal?)
striations. The eyes are unfortunately destroyed in all specimens seen,
but evidently were large. The suture separating the fixed cheeks is
also obliterated, but its position is approximately indicated in our
figure.

The thorax consists of ten distinctly separated segments. The
axial portion is high and evenly convex and the lateral portions are
rather abruptly flexed near the middle of their width and the plurae
are high and convex, not sulcate. The pigidium is one third wider
than long (Shumard’s specimen was a fragment).and the postero-lateral
outline is a perfect arc of a circle, whose centre lies axially about four-
fifths its length from the posterior extremity of the pigidium. The
axial portion is high and tumidly conical and rather obtuse, the mar-
ginal sulci being rather deep. The pleural portions are convex and
descend rapidly peripherally to the plane of the wide, convex, smooth
border which is unmarked or ornamented with concentric striations.
The axial segments are ten or eleven and are not sulcate, while the
eight or nine pleural ribs are distant and prominent and bifurcate to-
ward the outer end. Entire length, 1,80; width, i.oo; axial length
of head, .50; entire length, .85; length of pigidium, .70; width
of pigidium, i.oo; width of axial lobe of pigidium, .35; width of
axial lobe of thorax anteriorly, .40.

Shumard’s statement that the margin of the pigidium is concave,
was due to the exfoliation of that portion of the specimen. Several
of our specimens are in the same state of preservation.

Note. — Phillipsia elliptica^ M. and W. which, by a curious over-
sight, was omitted from our list, is much more like P. swallovi than
the present species. Refer to Pal. 111., vol. Ill, p. 460; Plate 14,
Eig. 8.

APPENDIX III. Flint Ridge Bryozoa.

BY A. F. FOERSTE.

The following bryozoa, from Flint Ridge and the equivalent strata
at Bald Hill, are the result of several days’ collecting at each locality.
Considering the wealth of bryozoa in the Carboniferous formations of
America, the literature is scanty and frequently very unsatisfactory.
Hiram A. Prout described about thirty- five species in the Trans. St.
Louis Acad. Sci., from 1858 to i860. James Hall described about
eight species, in the Proc. Am. Ass’n. Adv. Sci. in 1857, and three
species in the Geo. Rep. of Iowa, in 1858. F. B. Meek, alone and
in conjunction with Worthen, published about nine species. Romin-
ger, Dawson, Geinitz, White, Nicholson, and Swallow have each added
one or more species at various times. To these, E. O. Ulrich has
added about eighteen species in his American Paleozoic Bryozoa, pub-
lished from 1882 to 1884. To these publications of Mr. Ulrich I am
greatly indebted, as will appear throughout the following notes. Until
some of the species published by Prout and others are better under-
stood, the work on Carboniferous bryozoa will remain rather unsatis-
factory. It is hoped that the following notes will at least not further
involve this subject.

RHABDOMESONTIDyR, Vine.

Ramose bryozoa ; cells radiating in all directions from the central
axis, of one kind only, tubular, with an expanded aperture, and an
angular immature region.

Genus RHOMBOPORA, Meek.

Branches slender ; cells radiating from an imaginary central axis;
aperture oval, placed at the bottom of concave, rhomboidal or hexag-
onal “vestibules,” the latter separated by spines, frequently arranged
in one or more rows along the dividing ridges.

72

BULLETIN OF THE LABORATORIES

I. Rhombopora multipora, sp. n.

(Plate VII, Pig. I, a, b, c)

Branches doubtlessly dividing; in a length of 25 mm. no such
division has taken place, but traces in the rock about 10 mm. beyond
seem to indicate that some method of branching has occurred.
Branches of medium size, 1.4 mm. wide. Cells arranged in diagonal
intersecting and in longitudinal rows; at least 7 cells are found in a
distance of 2 mm. in the vertical rows, and about 9 cells in the
same distance in the diagonal series. About 20 longitudinal rows sur-
round the stem. Mature region of the cells short, strongly deflected
laterally, but not reaching the surface at right angles to the same ; im-
mature region much longer, departing from the centre of the branch
at a low angle, suddenly bending into the mature portion. The vesti-
bule in well preserved regions has sloping sides and an hexagonal oval
outline; the ridges separating the cells are rather narrow and are cov-
ered with low, indistinct closely arranged granules, which do not
seem to be arranged in well defined rows, as in other species of this
genus; in worn portions of the specimen the ridges seem broader and
lower, and the granules are indistinct, and scattered. Towards the
base the vestibule is more inclined, lengthening its outline; at or just
within its border there is frequently a low, rounded node, easily over-
looked.

From most species of this genus this form may be readily distin-
guished by the size of the branches and the more numerous cells. Rh.
lepidodendroidea., Meek., has branches 1.75 to 3 mm. wide; from 5.5 to
6.5 cells occupy the oblique rows (using a standard length of 2 mm.).
Rh. crassa, Ulrich, has branches 2.5 to 4.5 mm. wide; from 5 to 5.6
cells occupy the oblique rows. Rh. persimilis, Ulrich, has branches
.88 mm. wide ; 4.4 cells occupy the vertical rows, and 8 cells the ob-
lique rows. Rh. pidchella, Ulrich, has the same measurements as the
last. Rh. armata, Ulrich, has branches perhaps slightly wider than
the last two, about 5.5 cells occupy the vertical rows, and 9.5 cells the
oblique rows. Rh. elegantula, Ulrich, has branches 2.5 mm. wide,
from 3 to 4 cells occupy the vertical rows, and almost 5 cells the di-
agonal rows. Rh. Wortheni, Ulrich, has branches from 1.3 to 3 mm.
wide ; 6 cells occupy the vertical rows, and almost 9 cells the oblique
rows.

The nearest ally of this species in external features seems to be

OF DENISON UNIVERSITY.

73

Rh. lepidodendroidea, Meek. From this it may be distinguished by
the following characteristics. The mature region of the cells appears
more abruptly inclined to the immature region of the cells ; the ridges
between the cells are covered with smaller and more numerous gran-
ules, these are also present on the slopes of the vestibules, and are not
arranged in such well defined rows as in the other species. Meek in
his description of the type specimens gives the following measure-
ments: number of cells in .2 inch, measuring longitudinally, 12;
number of cells in .oc; inch measuring in the direction of the oblique
rows, 4. We have specimens from Kansas City which agree very
well with these measurements. The Ohio specimens on the other hand
present the following measurements: ^ number of cells in .3 inch,
measuring longitudinally, 17 ; number of cells in .05 inch, measuring
in the direction of the oblique rows, 6.

Rare at Flint Ridge. {Multipora many pores or cells.)

II. Rhombopora lepidodendroidea. Meek.

{Plate VII, Fig. 3. a, b.)

Zoarium branching, branches about i mm. wide, or slightly less.
Cells arranged in diagonal intersecting and in longitudinal series.
Longitudinally, 6 ceils occupy a length of 2 mm ; about 13 longitudi-
nal series surround the stem. Vestibule elongated, smooth, sharply
distinguished from the intermediate granule- bearing ridges. Granules
strong, readily seen even under a low magnifying power, arranged in
one, two, or even three rows along the ridges. At one end of the
vestibule a low node is frequently seen. The thin, immature portion
of the cells curves gradually outward into the mature portion, where
the curvature is increased and the walls become decidedly thickened.
The stems branch at intervals varying from 15 to 25 mm.

From the western forms of this species which we have seen, the
Ohio specimens show several variations. The branches are much nar-
rower, and instead of 4 cells, 5 cells may be counted in a distance of
.05 inch. The vestibules also appear more elongated. However the
fact that the branches are narrower would perhaps be sufficient to ac-
count for the other variations. Its wide geographical distribution is
also of interest in this connection. Meek mentions the species from
Nebraska,_ Kansas, Iowa, Missouri, and Illinois. In species of wide

74

BULLETIN OF THE LABORATORIES

distribution we are accustomed to look for variations, and our speci-
mens are probably the smaller sized form of the same.

Flint Ridge and Bald Hill. Rather common.

III. Rhombopora .

{Plate VII, Fig, 5, b, c.) .

A fragment showing the same internal features as the last probably
belongs to the same species. About 6 cells are found in a distance of
2 mm. in- the longitudinal series, and about 8 cells in the same dis-
tance in the diagonal series. The apertures are decidedly rhomboid,
the ridges bear rounded nodes at their intersections and show faint
traces of low granules between the cells. They recall strongly Meek^s
figures of the type specimens. They seem to us to owe their more de-
cidedly rhomboid character partly to the elfects of exfoliation of the
outer crust.

CYSTODICTYONID/E, Ulrich.

Frond composed of two or more layers of cells, united along their
epithecal membranes. Tubular cells with vertical folds or indenta-
tions, the remains of the crescent shaped lip. Interstitial spaces oc-
cupied by vesicular tissue, not visible at the surface.

Genus CYSTODICTYA, Ulrich.

Frond composed of two cell layers, branches compressed, divid-
ing dichotomously, with sharp, nonporiferous margins. Cells arranged
in diagonal intersecting series, with more or less marked longitudinal
series. Interstitial cells arranged in longitudinal series, angular; ar-
rangement more or less disturbed about the cells.

IV. Cystodictya carbonaria, Meek.

{Plate VII, Fig. 2, a, A c)

Plilodictya (Stictopora) carbonaria, Meek ; Proc. Acad. Nat. Sci. Phil.

XXIII., p. 16); Ohio Pal. Vol. II, p. 328.

Fronds dividing dichotomously at intervals from 5 to 15 mm,
branches very thin, non-poriferous margin narrow, smooth, or rarely
with faint striations. Branches 4 to 4. 7 mm. wide, with 9 to ii longi-
tudinal rows of cells. Cells arranged in diagonal intersecting rows,
more or less curved laterally and sometimes separated there by faint
grooves. Single undulating striations more less irregular extend

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75

longitudinally between the cell rows. Cells, five in a length of 2 mm,
seven to eight rows in the same distance in width.

Meek especially mentions the absence of striations, but the spe-
cies is very common at the locality he mentions, “Newark, Ohio,
Coal-measures,” namely, Bald Hill, and well preserved specimens, es-
pecially clear impressions, readily show the faint undulating stri^ other-
wise overlooked.

C. lineata, Ulrich, has a marked longitudinal arrangement of cells,
with marked longitudinal ridges extending between the cell rows.
The cells are also fewer in number.

C. occellata,. Ulrich, has the diagonal series of cells more curved
laterally and the separating furrows more marked, forming a distinct
feature of specific value. The branches are also wider.

Common at Bald Hill.

Genus, PRISMOPORA, Hall.

Fronds composed of three cell layers, hence triangular, dividing
(“ dichotomously,” Ulrich, and) trichotomously ; sides frequently une-
qual, concave, margin often serrated. Cells in oblique intersecting
rows, approaching the margins in the serrations, distant from the same
along the indented area. Interstitial cells in the form of vesicular
tissue, not visible at the surface.

V. Prismopora sereata. Meek.

{Plate VIT, Fig. 6, a, b, c.)

Ptilodictya (Stictopora) sereata, Meek, 1875, Ohio, Pal. Vol. II, p. 327.

Cf. Ptilodictya triangulata, 1878, White, Proc. Acad. Nat. Sci. Phil. p. 35.

Ptilodictya triangulata, 1879, White, Pal. Papers, No. XI, p. 214.

Ptilodictya triangulata, 1881, White, Appendix, Rep. of looth Meridian,
p. XXIV.

Ptilodictya triangulata, 1883, White, Contrib. to Invert. Pal. p. 13 1.

Prismopora serrulata, 1884, Ulrich, Am. Pal. Bryozoa, p. 41.

Zoarium dividing ; dichotomous branching alone observed, but
since the specimens are mostly in casts and never free, it can not be
determined with certainty that there was not a third branch. Speci-
mens from Danville, Illinois, found free, are all trichotomously di-
vided as far as we have observed. Branches triangular; the sides
sometimes very irregular. The sides are concave, concavity variable,
although always distinct. The three edges are all sharp and serrated

76

BULLETIN OF THE LABORATORIES

with wavy margins. The size of the serrations extremely variable ;
some of the most prominent seen being 1.4 mm. wide, 4 serrations
taking up a length of 9 mm. Cell apertures distinctly lipped on one
side, the lips not directed in definite related directions as far as known;
the apertures are not arranged in well defined lines, however, some
arrangement can always be discovered. Usually this consists in a dis-
position of the cell apertures in oblique intersecting lines across the
sides of the branches ; one of these oblique series can usually be readi-
ly seen, the other set are sometimes imperfectly developed; when
these oblique series are both well developed, longitudinal series are
necessarily present, although even in that case these longitudinal lines
run somewhat diagonally along the stem. In other words, diagonal
rather than longitudinal arrangement prevails. In the serrations the
cells are always more compactly arranged. Along the indented por-
tions, however, there is always a crescentic space, variable in size,
along which there are no cells, the margin is therefore interruptedly
celluliferous. As may be imagined from some of the remarks above,
the number of cells is variable. In one specimen 5 cells occurred in
a length of 2 mm. Interiorly the cells are surrounded by vesicular
tissue, irregularly arranged.

Meek clearly did not understand his own specimens; he did not
know that the branches were three-sided, but gave a thickness of .04
inch to his branches, supposing them to be flat. He also failed to no-
tice the distinctly projecting apertures of the cells with irregular lips.
White described his species from the Coal-measures at Danville, Illi-
nois, and states in a later publication that the type specimens were ob-
tained from Mr. William Gurley. I therefore applied to Mr. Gurley
for specimens he considered authentic, and received all he had. White
could not recognize the three-sided branches in Meek’s description and
so proceeded to describe his specimens as Pt. triangiilata^ and also
states that the cells are irregularly disposed at the surface. Specimens
at hand, from the original source, however, show the same arrange-
ment of the cells as noted in the Ohio specimens. Indeed, some of
the specimens from Danville show the oblique intersecting series very
beautifully. It must be remembered, however, that although diagonal
intersecting series are considered typical, most specimens are to some
extent variations from this type, however, even then they rather pre-
sent cases of disturbed regularity than typically irregular disposition.
The width is stated as varying from 3 to 5 mm; this is broad enough

OF DENISON UNIVERSITY.

77

to include our specimens from Ohio, but the average width of the Illi-
nois is less than that of Ohio forms, and in general the size of speci-
mens seems more variable at the former locality. Later in the Appen-
dix to the Report of Surv. W. of looth Meridian, PL IV, Fig. 2, White
figured one of the type specimens. This specimen falls below the
minimum width given in the original description, being only 2.5 mm.
wide, and is figured with scattered cells, irregularly undulating edges
and without crescentic nonporiferous portions regularly occupying the
incurved portions of the sides. However, since Fig. 2, e, on the
same plate, representing a specimen from Cebolla Creek, likewise
omits the crescentic non-poriferous characters of the margin, readily
seen in the original specimens, it is to be expected that in a small speci-
men this feature would be entirely overlooked. At any rate the small-
est specimen we have from Danville, which is 3 mm. wide, shows the
crescentic non-poriferous characters, the arrangement of cells noted in
the Ohio specimens, and a regularly undulating margin, all the charac-
ters being readily noted when attention has been once called to the
same.

Again, specimens from Chester, Illinois, of larger size, but of the
same average width as Ohio specimens, show no variations from the
latter in any particular. The same is true of the specimens just re-
ferred to from Cebolla Creek, New Mexico, Nos. 4480, 9447, and
9472 of the National Museum collections. In his Pal. Papers, No!
XI, White describes specimens from the middle Carboniferous series
of Yampa Plateau, N. W. Colorado, which are only 2 to 2.5 mm.
wide. We found in them the same crescentic nonporiferous spaces
as noted above in specimens from other localities. Finally, Ulrich
described a form from Tateville and Grayson Springs, Kentucky. It
is in every respect similar to the Ohio forms. He states: “This species
is readily distinguished from all other species of the genus known to
me by its wavy or serrated margins.” The three-sided character of
Meek’s specimen was unknown ; White in his original description
failed to mention the indentations of the margin, in his second descrip-
tion they are stated to be merely a little irregular, but in his third
description the scalloped character so readily noticed in larger speci-
mens is distinctly stated and in one example figured.

The general features of the species therefore consist in regularly
scalloped margins ; the serrations are not rounded typically, but are
more or less accurately truncated, sometimes even slightly concave,

78

BULLETIN OF THE LABORATORIES

the serrations decrease in prominence with the size of the specimens ;
the indentations are bordered by crescentic non-poriferoiis spaces ;
these spaces are large and conspicuous in the larger forms, decreasing
to narrow, but distinct proportions in the smaller specimens. The
specimens from New Mexico, Kentucky and Chester, Illinois, are un-
doubtedly the same as our Ohio forms. Those from Colorado are
readily connected, it seems, by the variable forms at Danville, Illinois.
In conclusion, I desire to express my gratitude to Prof. C. A. White,
of the National Mviseum at Washington, for the ready access to the
specimens described by him from western localities. The above dis-
cussion is designed merely to present a better understanding of this
species, from the abundant material which it has been my good for-
tune to see.

Common at Bald Hill; rare at Flint Ridge.

ACANTHOCLADIIDH:, Zittel.

Ramose bryozoa, dendroid, pinnate, or forming fenestrated ex-
pansions, consisting of strong central stems and smaller lateral branch-
es proceeding from the margins; the latter uniting in fenestrated gen-
era with the branches of adjacent stems. Stems and branches both
poriferous on one side only, non-poriferous dissepiments therefore
absent.

Genus GLAUCONOME, Goldfuss.

Main stem very slender, branches springing from the stem at large
angles, often at almost right angles. Celluliferous face of both' main
stem and branches with two alternating, longitudinal series of cells.
Non-poriferous side longitudinally striated.

VI. Glauconome whitii, sp. n.

{Plate VII, Fig. 4, <7, ci)

Largest specimen 18 mm. long and 6 mm. wide, evidently not a
complete zoarium. The stem is very slender, rounded, and regular
in thickness, having a diameter of about .22 mm. On either side are
branches, diverging from the stem at an angle varying from 65 to 82
degrees, usually nearer the angle first given. These branches are of
two kinds; the smaller kind are very narrow, about. 13 mm. wide,
and rather short, a millimetre or less is the length of the largest, so

OF DENISON UNIVERSITY.

79

far seen; the larger kind are slightly narrower than the main stems,
about 1-9 mm. wide, and are longer than the branches just described,
the length of the largest branch so far seen being 4 mm ; at a short
distance from the main stem these also bear very short minute branch-
es. Along the stem the branches are stationed with some regularity,
about 4 branches in a length of 2 mm ; three to four small sized
branches intervene between those of larger size when the latter occur.
At a distance of 1.6 mm. from the stem along one of the branches
the minute branches mentioned above begin ; these are stationed also
at equal distances apart, almost 5 in a length of 2 mm. The cell ap-
ertures are distinctly elevated above the surface of the stems and cause
irregularity in the surface. There is always a cell at each juncture of
a branch with the stem, near the smaller angle; and also one half way
between the successive branches along the stem. Since the alternation
of the cells is regular, the branches are therefore not strictly opposite,
although at first sight they may appear so. 'The presence and arrange-
ment of cells on stems and branches is similar, excepting that on the
smaller branches they are stationed closer together, as might be ex-
pected. Five to seven longitudinal wavy striae mark the poriferous
side ; two of these, somewhat more prominent and almost continuous,
though variable in distinctness, form a sort of median keel between the
cell rows. An equal number of striae mark the non-poriferous side ;
these are quite straight and are covered with numerous minute gran-
ules, scattered, or apparently forming three or four rows along the
stri^.

Glauconome trilineata, Meek, is readily distinguished by its larger
size, flattened stems and branches, and a median trilineate ridge on
the poriferous side which is very characteristic. Gl. nereidis, White,
differs in its larger size, the comparatively small space between the
branches, and in the presence of dimorphous pores upon the poriferous
side on the convex area between the regular cells.

Moderately common at Flint Ridge. Named in honor of the U. S.
Paleontologist, Dr. A. C. White, through whose courtesy I was per-
mitted free access to the valuable collections in the United States Na-
tional Museum at Washington.

Genus SEPTOPORA, Prout.

Zoaria fenestrated by the union of the short lateral branches of
adjacent stems ; cell rows, two ; dimorphic pores present. Synocladia,

8o

BULLETIN OF THE LABORATORIES

King, is distinguished by the absence of dimorphic pores, and the pres-
ence of more than two rows of cells.

VII. Septopora biserialis, var. gracilis, Meek.

(PlateKll, Fig. 7, a, b, c.)

Synocladia biserialis (gracilis, suggested), Meek, Ohio Pal. Vol II, p. 326.

Zoarium flabellate, composed of three or four strong radiating
stems, forming a net-work by pinnate division, and the union of oppo-
site, short, lateral branches. Intercalated stems, arising from the co-
alescing of lateral branches, are not unfrequent. All stems increase
in size above. Lateral branches short, inclining at angles of 60 de-
grees or more to the stems, those of adjacent stems uniting, the union
rounded, angular, nodose, or slightly produced. Poriferous face with
two rows of cells ; alternating with these, usually nearer the margin,
although sometimes between the cells, are pores of about one-third the
size of the cells. The median ridge is narrow, distinctly nodose,
nodes not quite as numerous as the cells on either side. Non-celluliferous
face, with the sides sloping from a convex median ridge, which some-
times is indistinct, longitudinally striated, striations strongest along the
median area. Dimorphic pores very small, situated singly or in pairs
at the junction of the branches with the stems, occasionally a few oth-
ers scattered about in various positions, but not with the frequency or
irregularity indicated by Meek in his figures of A. biserialis from the
Coal Measures of the West. •

‘ From Septapora biserialis. Swallow, this form may be distinguished
by the tendency towards the formation of a median ridge on the non-
poriferoLis side, by the regularity of arrangement of most of the dimor-
phic pores, both on the celluliferous and non-celluliferous sides, and
by the more distant stems and branches, forming larger fenestrules.
A. Cestriensis, Front, referred by E. O. Ulrich to A. biserialis as a va-
riety, differs from our form in wanting the dimorphic pores on the cel-
luliferoiis side, or at any rate in having them much less numerous.
Ulrich’s studies indicate great variability in this species, and our form
would give it also wide geographical distribution.

'The measurements in this case are variable and scarcely specific,
but a few may here be given of a specimen considered typical.
About 8 stems occur in a width of 10 mm ; 9 branches occur in the
same length. From the Feiiestellidce this species will of course be at

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8i

once distinguished by the celluliferous character of what might be
taken for dissepiments, even if these should unite neatly.

Common at Flint Ridge. ( Gracilis^ slender branches.)

FENESTELLIDAE, King.

Zoaria usually reticulate, poriferous on one side only, branches
united by non-poriferous dissepiments or anastomosing; in the latter
case there is never a division possible into stems and branches, so that
no confusion with the Acanthocladiidce need arise.

Genus CHAINODICTYON, gen. nov.

Zoaria flabellate or perhaps infundibuliform, branches inosculat-
ing, forming a loose net-work, the meshes of which are elongated,
elliptical, or oval, somewhat variable (as the openings in the fronds
of some Clathroporcd) . Branches flattened, sometimes even concave
on the non-poriferous side. Without longitudinal striae, as far as
known, but with very marked lunate striations or rather folds extend-
ing across the non-poriferous sides of the branches, similar to the lines
of growth seen on the epithecal membranes of Stictoporidcz. Cells
in oblique intersecting rows which give rise to three less evident, rather
irregular, longitudinal series. {Chaim, dictyon, net; alluding

to the elongated large meshes of the zoarium.)

Phyllopora, the nearest related genus, has rounded meshes; the
branches are far less flattened on the non-poriferous side, and are
finely striated longitudinally; on the poriferous side the cells have a
more regular arrangement into longitudinal rows ; it occurs in older
paleozoic formations; Chainopora maybe considered its later repre-
sentative.

VIII. Chainodictyon laxum, sp. n.

{Plate VII, Fig. 8, a, b, c.)

Meshes elongated, rhomboid, elliptical, oval, ovate, and obovate
in the same zoarium, typically elliptical, about 2.5 mm. long and 1.3
mm. wide. Branches narrow, about .3 to .38 mm. wide; the cells
are arranged in diagonal rows ; longitudinally about 5 cells may be
measured along the sides of the branches in a length of 2 mm. The

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BULLETIN OF THE LABORATORIES

cells arise near the nonporiferous side, are quite elongated, and reach
the surface at a very oblique angle. Longitudinal arrangement of cells
is incidental rather than typical and often obscured, whereas the oblique
series remain distinct.

Flint Ridge, rare.*^ iyLaxwn^ loose meshes.)

Genus POLYPORA, McCoy.

Zoarium flabellate or infundibuliform, poriferous on the inside;
branches nearly straight, connected at regular intervals by non-porifer-
ous dissepiments. No median keel on the poriferous side of the
branches; from two to six rows of cells.

IX. PoLYPORA FASTUOSA, De Konincli.

{Plate VII, Fig. 9, a, b, c, d.)

Zoarium infundibuliform. Branches dividing dichotomously, rap-
idly near the centre, then less frequently, becoming straight above.
Non-poriferous face with sloping sides, thus leaving a sort of carina
along the middle, varying from this to ordinary convexity ; the edges
of branches acute, frequently more horizontal than the sides of the
branches, thus forming a narrow margin along the fenestrules. The
dissepiments very prominent, as high as the branches or even exceed-
ing the same, less than a third the width of the branches, narrowly
compressed, and consequently carinated. These dissepiments are very
characteristic, giving the oval inclosed fenestrules an oblong outline.
Branches finely and closely striated longitudinally; dissepiments also
striated. Poriferous face convex. Cells arranged in four to six rows,
usually four or five rows; the diagonal series however are usually first
noticed. Cell apertures small, separated by twice their length longi-
tudinally. The spaces between the cells are longitudinally striated by
wavy lines. In another specimen, with the same characteristics on the
non-poriferous side, the poriferous face presents larger cells arranged
closely together without the intervening striations. The dissepiments
longitudinally striated.

The main characters in the identification of this species have been
drawn from Dr. Franz Toula, in his descriptions of Permo-carboniferous
fossils f7'om the west coast of Spitzbe7gen^ 1875, of Iho Carboniferous
Limestone Fauna from the Bai'ents Islands., N. W. of Nowaja-Semlja,

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83

1875. In the latter publication he states of the diagonal arrangement of
the cells ; “ This arrangement is first seen on the branches, when the ex-
terior layer has been removed. This layer, when best preserved, shows
distinct longitudinal striations; by abrasion or splitting off, the inner
portions of the cells appear arranged as stated above so‘ close to
one another that hexagonal outlines arise.” And later: “The di-
mensions of our specimens are very variable; the fenestrated branches
named are sometimes broader, sometimes narrower, and in a piece
narrower than usual, even 7 fenestrules are found in a length of 10 mm.”
Apparently the same variations are found in our specimens. The
largest has 5 fenestrules and 6 dissepiments in a length of 10 mm., 7
to 9 branches occur in the same distance in breadth. In one of the
smaller specimens, 7.3 fenestrules occur in a length of 10 mm. and
10.5 branches in the same breadth. From 7 to 9 cells occupy a length
of 2 mm. The fine longitudinal striae of the poriferous face of the
dissepiments are mentioned by Toula in his descriptions.

Common at Flint Ridge and Bald Hill.

Perhaps we have .confounded two species in the above descrip-
tion, one smaller than the other, or with smaller and more distant cells,
but we fail to find definite specific characters.

Genus FENESTELLA, Lonsdale.

Differing from Polypora in the presence of a median keel, the
cells being arranged in two rows, one on either side of the keel.,

X. Fenestella limbatus, sp. n.

{Plate VII, Fig. 10, a., b, c, d.)

In the limestones at Flint Ridge and Bald Hill are found numer-
ous specimens belonging to the genus Fenestella, all of which have the
following features in common. The zoaria are infundibuliform ; the
inner side is poriferous ; the median keel is well developed and dis-
tinct, along the summit it is occupied by a single row of rounded
nodes stationed at regular distances apart, and calling to mind such
PolyporcB as may be typified by Polypora submarginata, Meek, for in-
stance, (Pal. East. Nebr. Meek, 1872); the nodes often appear hollow,
where abraded, but never alternate with small pores as in the species
just cited. The nodes are somewhat more numerous than the cells.
Another equally characteristic feature is the form and arrangement of

84

BULLETIN OF THE LABORATORIES

the cells. Typically one cell is placed at each corner of the fenestrule
at the junction of the dissepiments with the branches, another cell is
situated on each side of the fenestrule half way between the two cells
already located; the number of cells is therefore typically twice
that of the dissepiments ; but occasionally two cells may fall in this .
intermediate region and the next cell is thrust to a position just above
the next dissepiment, but the typical distribution is easily recognized
in the complete individual. The cell mouths are very large, so that
the corners of the fenestrules are rounded and near the middle they are
constricted, giving a very peculiar appearance to the fenestrules. The
broad cells thus give the branches a very characteristic appearance
which is suggested in the specific name limbattis, bordered.

Here all similarity ceases. The specimens vary from small, fine,
delicate forms, to those which are quite coarse. It seems bold almost
to associate such forms under one specific name, but we fail to find
specific characteristics, although we have abundant material and prefer
to designate one well-defined species, to naming several which inter-
mediate forms refuse to admit. Considering them as one species we
have the following description of the non-poriferous side. Dissepi-
ments from one-fourth to almost one-half the size of the branches.
Fenestrules oblong, the corners angular, varying to coarsely granular,
then often with quite large granules in distinct longitudinal rows, often
longitudinally striated, especially in worn specimens. Branches from
lo to 13 in a width of 5 mm., dissepiments 9.5 to 13 in the same length.

As types of this species we take the smallest specimens.

XI. Fenestella limbatus, var. remotus.

{Plate VII, Fig. II.)

A variety having all the other features of this species differs only
in having the dissepiments relatively farther removed from each other
as shown by the following measurements: 10.5 branches occupy a
width of 5 mm, 6.5 dissepiments occupy the same distance in length.

Found with the above.

OF DENISON UNIVERSITY.

85

MONTICULIPORID.®, Nicholson.

Zoarium with tubular cells, which are thin walled and polygonal
below, above they are bent more decidedly towards the sur-
face, are of nearly equal size throughout, more or less thickened and
rounded, but never lipped nor separated by vesicular tissue. Zoari-
um occasionally frondose, but never composed of two distinct layers
of cells entirely separated by the epithecal membranes. A distinct
section of this family typified by the following genus will no doubt
soon be separated from the same and made an independent family.

Genus STENOPORA, Lonsdale.

Zoarium ramose. Cells of the mature region more or less annu-
lated periodically, with large spiniform tubuli at the angles and straight
diaphragms, frequently operculate. Species often erroneously referred
to Chcetetes.

XII. Stenopora Ohioensis, sp. ft.

{Plate VIII, Fig. 12, a, b, c, d, e.)

Branches sub-circular dividing at intervals of about 30 mm. show-
ing faint traces of bilateral arrangement in the immature region.
In the immature region the cell walls are thin and polygonal. In
the mature region the cell walls become strongly and closely an-
nulated by periodical thickenings, crossed by thin diaphragms at the
annuls. Spiniform tubuli of large size occupy the cell angles, others
of smaller size are found on the intermediate cell walls, encroaching
below upon the cell cavities as vertical ridges. Well preserved speci-
mens show operculate mouths. Cells irregular in size, the smaller
more angular, but not distinguishable in vertical section. About 10
cells occupy a length of 2 mm; branches 5.6 mm. thick.

Locality a?id position. Flint Ridge.

XIII. Stenopora carbonaria, Worthen.

{Plate VIII, Fig. 13, a, b, c.)

Branches of larger size than the last, 8.9 mm. thick. Cell walls
not distinctly annulated ; cells larger, crossed by more distant dia-
phragms, operculate, operculse visible both in cross and vertical sec-
tions, also in hand samples. Large spiniform tubuli at most of the
angles of the cells, intermediate spiniform tubulae wanting. Some

86

BULLETIN OF THE LABORATORIES

specimens indicate interrupted growth in the zoarium. About 7 cells
occupy a length of 2 min.

Locality and position. Bald Hill and Flint Ridge.

Among the Flint Ridge collections corals are exceedingly rare
and only one species has so far been recognized, belonging to the fol-
lowing genus.

Genus CYATHAXONIA, Michelin.

Single polyp cells, with diaphragms, the invaginated centres of
which form a solid central axis, the cristiform columella. Radial 1am-
ellse well developed, terminating as superficial carinations on the con-
ical centre of the diaphragms. (Rominger, Fossil Corals, Geol.
Surv. Mich. Vol. Ill, p. 96).

Cyathaxonia prolifer a, McChesney.

{Plate VIII, Fig. 15, <2, b, c.)

Coral conical, nearly straight, or curved below; epitheca thin,
marked by distinct vertical ridges locating the apertural and lateral
gaps distinctly; calyx nearly circular, deep; radial lamellae 20-28,
beginning as carinations at the mouth of the calyx, slowly enlarging
below and ending as ridges on the invaginated diaphragms ; alternat-
ing with these lamellae are carinations or secondary lamellae, which
reach scarcely more than half the distance down the calyx, and there-
fore are seen only in well preserved specimens ; the columella com-
pressed laterally, the larger axis in' line with the apertural and central
gaps, very prominent.

Largest specimen so far found 22 mm. long, and 17 mm. wide at
the mouth of the calyx ; the calyx is 13 mm. deep, the columella pro-
truding into the same fora distance of 7 mm; the columella is 2.7
mm. wide below, and about i mm. thick. The columella is not al-
ways so well preserved.

Locality and position. Flint Ridge and Bald Hill.

During the publication of these pages I learned that Mr. E. O.
Ulrich was engaged on a similar list of bryozoa from the base of the
Coal Measures at Seville, Illinois, for the Illinois Geol. Surv. Vol.

OF DENISON UNIVERSITY. 87

VIII. From his copious notes on the specimens submitted to him for
examination, most of the following are extracted.

Rhombopora multipora^ n. sp, is found at Seville, 111.

Glauconome, Goldfuss, is a synonym for Vincularia^ De France^
having been originally used to designate Mesozoic species of the lat-
ter genus ; our species must therefore be referred to Pinnaiapora^ Vine.

Pinnatopora Whiiii, n. sp, is closely related to P. bellula., Ulrich.,
from Seville, differing in the possession of a double ridged median keel
on the celluliferous side, and in the absence of distinct granules form-
ing single rows on the striae of the reverse, 4.3 cells occur in the same
distance as 3 cells in P. bellula, Ulrich.

Septopora biserialis, Swallow ; a form resembling the western types
of this species as figured by Meek, is found at a horizon about 100
feet above the Flint Ridge layer, near Brownsville. The branches are
more or less wavy, rounded on the non-poriferous side, the dimorphic
pores quite numerous, one or two stationed at the junction of the stems
with the branches, the rest scattered. The dimorphic pores of the
celluliferous side appear usually between the cells, rather than just
without the line formed by them, as is more commonly the case in S.
biserialis, var. gracilis.

Chaim dicty on laxum, n. sp, is also found at Seville, Illinois. Gen-
erically, the following cell structure is of importance. Arising near
the reverse side of the bryozoum the cells are at first somewhat de-
cumbent, then they enlarge, become compressed laterally, and bend
towards the celluliferous surface, opening upon the same as elongated
oval or elliptical cells more or less bounded on each side by single lon-
gitudinal wavy striae.

Fenestella limbata, n. sp, is very closely allied to F. mimica, Ul-
rich, as figured in the forthcoming Illinois report, pi. LII, fig. 7. The
median keel of the Ohio specimens, however, is more prominent and
distinct than in that species, but not at all as large as the median keel
of F. Wortheni, Ulrich, fig. 5, of the same plate.

Fenestella remota, n. sp. [F. limbata, var. remota, ante), proves on
further examination to be a well marked species, with four cells to
each fenestrule, a comparatively broad median keel occupied by a
closely arranged , series of nodes. The reverse is occupied by distinct
longitudinal striae.

88

BULLETIN OF THE LABORATORIES

Plate VIL

Fig. I. Rhombopora multipora, n. sp; a, type; b, part of the surface, X 14;
vertical section, X 4.5.

Fig. 2. Cystodiciya caj-bonaria, Meek; a, frond; b, part of the surface, X 6. 5;
c, cross-sections showing indented cells and angular interstitial cells, X 6.5.

F'ig. 3. Rhombopora lepidodendroidea, Meek; a, fragments ; b, part of the
surface, X18.

Fig. 4. Pinnatopora {Glattconojne, ante), Whitii, n. sp; a, type; b, cellulifer-
ous side, X 10 ; c, non-celluliferous side, X ii ; d, section showing internal ar-
rangement of cells, X II,

Fig. 5. Rhombopora ? lepidodendroidea. Meek; a, part of the surface, X 8 ; b,
section ; c, the same, X 3.^.

Fig. 6. P7dstnopora sereata, Meek; a, cast, trichotomously dividing at one
corner; b, surface; c, cross-sections; d, specimen from Danville, Illinois, dividing
trichotomously, with cross-section ; e, a side of another specimen.

Fig. 7, Septopora biserialis, var. g7'acilis. Meek; a, non-celluliferous side; b,
the same, X 4,2 ; c, section showing position of cells and dimorphic pores of the
celluliferous side, X 8.

Fig. 8, Chainodictyon Iax7t77i, n. sp; a, zoarium ; b, non-celluliferous side,
X 3 ; c, cells, surface view, X 15, and lateral views, X 5,

F'ig. 9, Polypora fastuosa, De Ko7nnck; a, non-celluliferous side; b, the same,
X4; c, celluliferous side, X3, a part, X8; d, another species, a part, X4,

Fig. 10, Fenestella limbata, 7t. sp; a, type; b, celluliferous side, X 11.4; c,
non-celluliferous side, X 12.3; d, larger form ; e, view of a branch, X 13.

F'ig. II, Fenestella re77iota, 71. sp. (7t. var. a7tte); a type; b, cast, X 13,

Fig. 12. Stenopo7'a Ohioe7tsis, 7t. sp; a, part of the surface, X 16 ; tangential
section, X9,5; the same, X 20; d, vertical section of mature portion showing
cross-section of annulae with their connecting cell-wall and diaphragms, also a lat-
eral view of the annulations and three of the vertical thickenings of the cell- wall,
which in tangential sections appear as darkened spots in the cell walls, X 12, also
a part enlarged, showing that the walls of contiguous cells are not divided from
each other, X 18; e, piece of a branch with cross-section showing tendency to-
wards bilateral structure.

Fig. 13, Stenopora earbona7'ia, Wo7‘then, a, part of the surface, X 12; b, tan.
gential section with traces of operculate diaphragms, X 12; c, vertical section indicat-
ing periodical growth, with diaphragms interrupted by operculse, X 12,

Fig. 14, Phillipsia Shumardi, Herrick; a, entire specimen; b, detached mova-
ble cheek.

Fig. 13, Cyathaxo7iia prolifera, McChesney; a, lateral view ; b, section passing
through longer axis of columella; c, view of calyx showing columella, (Plate II,
Fig, 21, internal cast of calyx,)

Fig. 16, Septopora biserialis. Swallow; a, part of a zoarium ; b, non-cellulifer_
ous side, X 6; celluliferous side, X 7. Specimen found half a mile west of
Brownsville, 100 feet above the horizon of Flint Ridge specimens.

II.

THE CLINTON GROUP OF OHIO. PART IF

BY A. F. FOERSTE.

CRUSTACEA.

I. Acidaspis Ortoni, . . . n. sp.

IL Proetus determinatus, . . . ’ n. sp.

HI. Proetus ,

IV. Iltenus Daytonensis, . . Hall and Whitfield.

V. ^Illaenus Madisonianus, . . Whitfield.

VI. Illaenus ambiguus, . . . Foerste.

VIE Calymene Vogdesi, . . . n. sp.

VIII. Ceraurus , .

IX. Lichas breviceps, . . . Hall.

X. Phacops pulchellus, . . . n. sp.

XI. Dalmanites Werthneri, . . Foerste-

XII. Encrinurus Thresher!, . . n. sp.

In the first paper of this series two new species of trilobites were
published and a provisional arrangement of the others was made.
Since its publication fresh material has been accumulating and a wider
literature has been examined, so that many things then left undecided
can now be definitely determined. The following pages may there-
fore be considered a revision.

90

BULLETIN OF THE LABORATORIES

Genus ACIDASPIS, Murchison.

I. Acidaspis Ortoni, n. sp.

{Plate VIII, Fig. 1.)

Acidaspis , D. U, Bull., Vol. I, p. loi, pi. XIII, fig. 23.

Head semi-circular in outline, moderately convex in the regions
of the glabella, suddenly depressed along the movable cheeks, the gen-
eral effect being to give the head a very convex appearance.

Glabella complex in structure, three-fourths as long as broad;
mesial lobe oblong, its length equal to twice the breadth, with three
lateral pairs of lobes ; the first pair very small, and near the obtuse
anterior border; the second pair of moderate size ; the last pair large,
oblong, occupying almost half the length of the mesial lobe ; the two
posterior pairs of lobes distinctly separated from themselves and the
fixed cheeks by furrows, from the mesial lobe by deep grooves. Fixed
cheeks provided with a furrow extending from the posterior part of the
eyes to the anterior part of the glabella, cutting from the fixed cheek
a lanceolate strip, the pointed end of which lies against the anterior
border of the middle pair of lobes; along this furrow, beginning at
the eye, extends a narrow ridge almost to the anterior pair of lobes.
The facial sutures anterior to the eyes begin the ridges just described,
and then gradually separate from the same, cutting the anterior margin
of the head with about the same curvature that the corresponding part
of the ridge possesses ; posterior to the eyes they extend in a curve later-
ally, then posteriorly to the posterior border of the head at a point
slightly removed from the postero-lateral spine. Occipital ring sepa-
rated from the glabella by a groove, of large size, laterally becoming
depressed and attenuated, terminating at the groove which separates
the posterior pair of lobes from the fixed cheeks.

Movable cheeks with a raised border along the lateral edge from
which a number of spines (about ten) extend j at the postero-lateral
edge is quite a long spine ; from this spine a border extends along
the posterior margin of the head, gradually becoming attenuated until
it almost reaches the end of the occipital ring. Owing to the sudden
and very great depression of the posterior lobes and fixed cheeks along
the posterior border of the head, and the position of the occipital

OF DENISON UNIVERSITY.

9^

groove, the occipital ring seems to extend quite a little distance beyond
the posterior border. ? -

A glabella figured by F. B. Meek, in Shumard’s Reports for the
Geological Survey of Missouri, for 1855, from the Cape Girardeau
Limestone, Acidaspis HalU, is a similar species, although much smaller.

Length of glabella in one specimen of moderate size, 8 mm ; in-
cluding the occipital ring, ii mm; breadth of the mesial lobe, 4.6
mm ; including the posterior lobes, 1 1 mm, between the inner margin
of the eyes, 15.3 mm, between the postero-lateral margins, 21 mm;
convexity of the head, 3 mm.

Named after Prof. Edward Orton, the distinguished State Geolo-
gist of Ohio.

Locality and position. Brown’s Quarry, two miles west of New
Carlisle, Ohio, Clinton Group.

Genus PROETUS, Steininger.

II. Proetus determinatus, sp. 11.

{Plate VIII, Figs. 2, 3, 3^:.)

Bathyurus , D. U. Bull., Vol I, p. 103, pi. XIV, fig. 5.

Glabella conical, convex, sharply defined from the remaining por-
tions of the head by a distinct furrow ; obscurely marked by three pairs
of grooves; the posterior pair being inclined at an angle of forty- five
degrees to the axis of the glabella, cutting off the postero-lateral cor-
ners; the middle pair, although shorter and less inclined, are still fairly
distinct; the anterior pair are very indistinct, quite short, and but
slightly inclined ; in addition three very indistinct pairs of pits may be
seen, the two anterior pairs are at the ends of the two anterior pairs of
grooves, the posterior pair are opposite the middle of the posterior
grooves. In the very distinct occipital furrow beneath the postero-
lateral corners of the glabella are two almost triangular tubercles
which add to the conical appearance of the glabella. The occipital
ring, broad at the middle, narrow at the ends, is supplied with a dis-
tinct granule near the centre.

The anterior margin of the head is curved downwards, giving this
portion of the head a distinctly convex appearance ; the edge is nar-
row, but plainly elevated at an angle of perhaps forty degrees with
those parts of the anterior margin immediately adjacent. The palpe-

92

BULLETIN OF THE LABORATORIES

bral lobes are rounded, and are situated opposite the anterior half of
the posterior furrows. The facial sutures anterior to the palpebral
lobes curve slowly outward toward the anterior edge, then suddenly
inward again cutting the edge beyond a line passing through the lat-
eral edge of the tubercles.

In this genus the facial sutures behind the eyes are parallel for a
short distance, then curve outward and reach the posterior border of
the head, usually at a point half way between the glabella and the
postero-lateral margin of the head. In Cyphaspis the posterior fur-
rows become deep grooves, dividing the glabella into three distinct
lobes, of which the central lobe is obovate in form. The middle and
anterior furrows are usually wanting. The tubercles found in the Ohio
species have not this signification, but are caused by the bifurcation of
the occipital furrow.

Length of smaller specimen, glabella, 3.5 mm; including anterior
margin, 5 mm. Breadth of glabella, 3. i mm ; including palpebral
lobes, 4.5 mm ; width measured between the antero-lateral margins of
the area anterior to the glabella, 4.5 mm. Length of the larger speci-
men, glabella, 7 mm ; including occipital ring, 8.2 mm; including
also anterior margin, 10 mm. Width of glabella just above the tuber-
cles, 7 mm.

Name signifies bounded, outlined, the limits established, and refers to
the distinct outline given to the glabella by the surrounding furrow.

Locality and position. Soldiers Home, near Dayton, Ohio. Clin-
ton Group.

III. Proetus .

(Plate VIII, Fig. 5.)

Fragments of the glabella of a species are found which are readi-
ly seen to be distinct from the species just described, but which do not
admit of a definite determination. There is no distinct, flat border
anterior to the glabella; instead, the broad groove lies close to the
glabella anteriorly, separating from the same laterally, and defining
the raised rim along the anterior edge of the head. This rim makes
an angle of 45° with the adjacent parts of the head. Only one set of
grooves is distinctly visible and that is the pair along the postero-lateral
margins of the glabella. They begin within the anterior portion of
the palpebral lobes and are directed backwards and inwards at the

OF DENISON UNIVERSITY.

93

same time. Tubercles and posterior parts of the glabella are unknown.

Length of glabella, 3.5 mm, including the rim, 4.7 mm; distance
between edges at junction of facial sutures with the anterior outline of
the head, 3.7 mm.

Locality and position. Brown’s Quarry. Clinton Group.

Genus ILL^NUS, Dalman.

IV. Ill/enus Daytonensis, Hall and Whitfield.

(Plate Wll, Figs. 6, 7.)

At Brown’s Quarry a head of this species was found by Prof. W.
S. Hoskinson, of Wittenberg College, which presents the movable
cheeks and the rostrum in position. Unfortunately the postero-lateral
regions of the movable cheeks are broken off. The character of the
rostrum may be easily seen from the figure. The facial sutures extend
along the anterior border of the head, of which the rostrum appears
a continuation. The movable cheeks become attenuated anteriorly
and take a twist which gives their surface a direction in 'the same plane
with the rostrum, against which their tips are accurately fitted.

Locality and position. Soldier’s Home Quarries, Brown’s Quarry,
Ludlow Falls (movable cheek and part of a glabella), Fair Haven (a
pygidium), Fauver’s Quarry (a pygidium). Clinton Group.

In Ohio this species is the most widely distributed and most char-
acteristic form of the Clinton Group. It would be interesting to
know if this is also the case in Wisconsin and Illinois, where similar
specimens are said to occur (Ohio Pal. Vol. H, p. 120).

I have seen this species in the collections of the Central Park
Museum, labeled Hamburg, Illinois.

V. Ill^nus Madison I an us, Whitfield.

(Plate VHI, Fig^. 8, 9, 10, loa.)

I

Since the publication of the last peeper little has been added to the
knowledge of this species. In that paper two specimens were de-
scribed. The first pigidium from Huffman’s Quarry was very convex
and had the anterior edge arching decidedly forwards. The other
specimen from Stolz’s Quarry was much flatter, broader and less arch-
ing anteriorly. At Brown’s Quarry numerous pygidia are found, which

94

BULLETIN OF THE LABORATORIES

approach the latter specimen, although sometimes quite convex and
more or less arched anteriorly. Associated with these pygidia are gla-
bellse, which would be referred to IllcEnus ambiguus without hesitation,
if the corresponding pygidia were found. However the following
slight distinctions may be discovered. The anterior margin is less
curved, the curve of the facial suture anterior to the palpebral lobe is
less marked, the glabella is less convex, especially along the median line.
All of these characters in themselves would hardly give rise to a new
species. Whether there are two species with different pygidia, but
very similar glabellae, is unknown. If not, the glabellae of Brown’s
Quarry must be referred to lUcemis ambiguus. Lieut. A. W. Vogdes
writes to me, as Prof. Whitfield’s opinion, that the pygidia are related to
those of IllcEniLs insignis, Hall^ as figured in N. Y. Report of State Cab.
20. But these evidently do not belong to the glabella which typifies the
species. Hence in either case the affinity of the pygidia of Brown’s
Quarry remains undecided. More material is perhaps necessary to
determine this question definitely.

Locality and position. Huffman’s Quarry, Stolz’s Quarry, Brown’s
Quarry, Clinton Group.

VI. Ill^nus ambiguus, Foerste.

' This species was founded upon a number of pygidia and gla-
bellas which have a wide range and are usually found associated to-
gether. In the first paper, figure loc, of plate XIV, is inaccurate,
representing the upper length of the grooves as being very distinct,
whereas in reality this part is very faint and the pits at the extremity
of the grooves seem to be isolated, if the glabellae be not carefully ex-
amined.

Locality and position. Soldiers’ Home Quarries, Fauver’s Quarry
(pygidium and fragment of glabella), Fair Haven (pygidium). Clin-
ton Group.

A hypostoma, not very unlike that figured by Billings under
Asaphus Pelops., is found at the Soldiers’ Home (Plate VHI, Fig. ii).
I am uncertain with what Clinton forms to place it. It is certain at
least that the hypostomae of the genus Illaenus figured by Gerhard
Holm, in his work on the Swedish species, are very unlike the hypos-
toma in question.

OF DENISON UNIVERSITY.

95

Genus CALYMENE, Brongniart.

VII. Calymene Vogdesi, sp. n.

{Plate VIII, Figs. 12, 13, 14, 15, 16.)

Calymene Blumenbachii ? Brongniart, D. U. Bull., Vol. I, p. no, pL
XIII, fig. 25.

Calymene . D. U. Bull., Vol, I, p. 109, pi. XIII, fig. 24.

Calymene Clintoni, Vogdes, 1882, Acad. Nat. Sc., Phila., Proc., p, 178,
fig- 3-

Head semi-circular, moderately convex. Glabella with three lat-
eral pairs of lobes; the posterior pair triangular-oval and well defined;
the middle pair half the size of the latter; the anterior pair small.
Glabella depressed towards the occipital furrow, defined from the an-
terior half of the fixed cheeks by very deep furrows which merge into
a groove, defining the anterior part of the glabella, and separating it
from the anterior border. Palpebral lobes slightly anterior to the mid-
dle lobes of the glabella. Fixed cheeks and adjacent parts of the
movable cheeks, greatly elevated, curving rapidly downwards towards
the sides and furrowed along the border by a deep, broad groove,
which, anterior to the fixed cheeks, merges into the grooves defining
the glabella. Just in front of their junction a low tubercle is seen on
either side of the border.

The anterior border is quite long, about one-third the length of the
glabella, depressed posteriorly along the glabella forming a groove,
otherwise quite flat, not arched in the middle, and elevated at a slight
angle above the plane formed by the base of the head. Facial sutures
parallel anterior to the eyes along the fixed cheeks, then curving slight-
ly outward .and inward again to the anterior edge of the head.

Thorax trilobate ; the mesial lobe convex ; lateral lobe broader, at
first horizontal, then curved backwards and downwards; pleurae
grooved anteriorly, about one-third of the pleura lying in front of the
groove; extremities of the pleurae unknown.

Pygidium strongly curved, almost semi-circular anteriorly, moder-
ately curved posteriorly, almost straight behind the mesial lobe. Mesial
lobe tapering posteriorly ; the anterior portions indefinitely known on ac-
count of the broken condition of the specimen, but apparently there is a
half segment, followed by six segments, terminating in a wedge-shaped
piece, rounded behind and equal in length to the last three segments.
Lateral lobes with segments strongly curved to conform with the ante-

BULLETIN OF THE LABORATORIES

rior and lateral margins of the pygidium, the last pair bordering upon the
grooves which divide the mesial from the lateral lobes. The last pair of
lobes, together with the posterior border, give the mesial lobe the
peculiar appearance of terminating in a box, or rather an enclosure
which is bounded on two sides by raised lines almost parallel, and on
the third side by the posterior outline of the pigidium.

The size is readily enough obtained from the figures and from the
description of the form formerly described under C. Blumenbachii.

Associated with these specimens are others of smaller size, de-
scribed under a separate heading in the first paper, but now believed
to be identical. They vary from the typical forms in possessing a less
distinct groove along the anterior edge of the glabella, the groove
almost merges into the flattened surface of the anterior border, the
tubercles at the junction of the lateral and glabellar furrows are scarce-
ly visible, often obsolete and the border appears raised at a somewhat
higher angle. However, it is now believed that the larger specimens
present the features of the smaller forms in a very marked degree,
magnifying their characteristics so as to seem distinct.

Lieut. A. W. Vogdes finds a form at Catoosa Station, also in the
Hematitic bed at Dug Gap, Clinton Group, Georgia. This he identi-
fied with Calymene Clintoni, Vanuxem. Expressing the belief that the
Ohio specimens should be referred to the same species, he requested
the loan of my specimens, and sent me his in return. The identity of
his specimens with mine is apparent. The anterior border has been
flattened down by pressure, the groove anterior to the glabella is thus
made indistinct, the irregularities of the border immediately in front
of the groove appear as indistinct low tubercles, or rather an uneven
raised line is formed defining the groove immediately anterior to the
glabella.

Since Lieut. A. W. Vogdes had access to the type specimens of
Calyjnene CUntoni, at the Am. Mus. of Nat. Hist., Central Park, N. Y.
and I doubted the identity of Ohio forms with these, I requested him
to compare the specimens, and give me an expression of his opinion.
He did so very kindly and thoroughly. Considering the very great
similarity of the species of Calymene, and the synonomy to which this
leads, it is considered desirable to distinguish a new species carefully
from all others with which it might be associated. The following
notes are therefore extracted from the correspondence of Lieut. A. W.
Vogdes.

OF DENISON UNIVERSITY.

97

The first is the well known Calymene Blu?nenbachii of the Wen-
lock Series of England. The forms of this species represented by
Salter (Paleont. Soc. Vol. 1863, pi. 8, figs. 7-16; pi. 9, figs. 1-5, var,
Auctorum), approach the American species. The head represented on
plate 9, fig. I, from the Lower Wenlock Grits (Niagara Series), shows
a wide frontal margin similar to the Ohio and Georgia forms ; the head
figured on plate 9, fig. la, has a straight anterior margin with a nar-
row limb, whereas the American forms have this part rounded with a
comparatively broad limb. The pygidia figured by Salter, plate 8, fig.
8c, and plate 9, fig. ib, have a general similarity, although the Ohio
forms show a tendency to extend their side ribs more to the rear, giv-
ing the pygidium a semi-circular outline.

The Bohemian Upper Silurian form described by Barrande (Syst.
Sil. Boheme, Vol. I, pi. 19, figs. 1-19, Calymene diademata, Etage E )
represents a form with a broad frontal margin (pi. 19, fig. 12), thick-
ened and incurved ; whereas, the Ohio species has its frontal margin
extended, the anterior border of the head forming a broad and even
curve about the head, turned slightly upwards and not arched in the
middle, the limb being exceedingly broad and separated from the an-
terior margin of the glabella by a deep groove. Barrande’s figure, pi.
19, fig. 18, represents a broadly rounded pygidium, the axis being an-
teriorly broad, and tapering ’posteriorly, marked by six axial rings.
The sides are marked by five bifid segments. The Ohio species has a
semi-circular pygidium, the posterior margin being almost straight. The
axis is broad anteriorly and tapers posteriorly to a rounded extremity,
marked by nine well defined axial rings. The sides have five bifid
segments, and a posterior undivided pair. The anterior segments be-
ing extended backwards to such a degree as to form a semicircle.

Angelin’s figures of Calymene spectabilis (Pal. Scand. pi. 19, fig. 5,
Reg. E), which Salter refers to Calymene Bliimenbachii^ lacks the
broad frontal margin of the Ohio forms. The pygidium of this species
as represented by Angelin’s figure shows the common rounded poste-
rior margin of the English species, Caly7nene Blumenbachii.

The American Calymene Clintoni is distinguished by the smooth
side lobes of the pygidia. It is found in the Niagara Group shales, at
Rochester, N. Y., below the falls.

Calymene 7na7nmillata^ Hall, (Geol. Rep. Wis. 1861, p. 50), from
the shales above the Trenton Group, has its anterior border extend-
ed in front of the glabella in a broadly rounded, thickened projection

98

BULLETIN OF THE LABORATORIES

which is abruptly recurved at the margin and marked on each side by
a mammilliform tubercle.” Only the largest Ohio specimen shows
signs of the tubercles, and the margin of none of the specimens is re-
curved. It is hoped that with these comparisons the character and ex-
tent of this species may cause no trouble.

Named after Lieutenant A. W. Vogdes, who has aided so much
in the elucidation of this species.

Locality aiid position. Allen’s Quarry, Soldiers’ Home Quarries,
Ohio ; Catoosa Station, Hematitic bed at Dug Gap, Georgia ; Clinton
Group.

Genus CERAURUS, Green,

VITI. Ceraurus .

{Plate VIII, Fig. 17.)

This species, known only by a single glabella, is distinct from any
known to me in the same series of rocks. However, it is not deemed
wise to give it a specific name, since that might only lead to unneces-
sary synonomy.

Glabella oval, convex, the posterior border inclined to be straight,
with three pairs of furrows; the posterior pair are situated about a
third of the length of the glabella from the posterior margin of the
same, they curve gradually inwards and backwards, causing the glabel-
la to appear lobate. A little in front of the middle of the glabella is
the second pair of furrows, which are shorter. In front of these are
the anterior furrows, not so decidedly curved backwards. All these
furrows appear to consist of two narrow furrows running very close
together in a narrow groove. The little trace of the occipital groove
remaining indicates that the occipital ring was strongly depressed to-
wards either side.

Locality and position. Brown’s Quarry, Clinton Group.

Genus LICHAS, Dalman.

IX. Lichas breviceps, LLall.

{Plate VIH, Fig. 18, 19.)

Since the publication of the first paper, numerous specimens have
been found at John Brown’s Quarry. The structure of the head is now

OF DENISON UNIVERSITY.

99

better understood, and the following description represents the present
knowledge of the same.

Glabella trilobate. The middle lobe broadly rounded anteriorly,
laterally deeply incurved and almost parallel, posteriorly produced on
either side something like an apothecary’s pestle. Lateral lobes long,
sub-reniform, lying against the incurved portion of the mesial lobe,
bending about the pestle-like base of the latter. Palpebral lobes reni-
form, the convex side turns outwards, the anterior part attenuated, the
inner side depressed and defined from the fixed cheeks by a groove
more or less distinct. Fixed cheeks between the eyes and glabella are
ovate in form, at the base, however, they extend laterally along the
posterior part of the head, the facial sutures cutting the posterior mar-
gin of the same. Between the fixed cheeks, the lateral lobes of the
glabella, the tips of the mesial lobe, and the occipital ring, lie on either
side small laterally extended tubercles, well defined by furrows.

The hypostoma of this species is frequently found. The figure
will readily enough distinguish the same.

Locality and position. Brown’s Quarry, Soldiers’ Home Quarries,
Fair Haven (a glabella), Clinton Group.

Genus PHACOPS, Emmrich.

X. Phacops pulchellus, sp. n.

{Plate VIH, Fig. 4, 20, 21.)

Arionellus , D. U. Bull., Vol. I, p. 114, pi. XIV, fig. 3,

Head semi-circular, convex. Glabella convex and broadly round-
ed anteriorly, narrowed posteriorly, marked by three sets of grooves,
all of them curved, the convex side being directed upwards or inward.
The first set consisting of two pairs of grooves are horizontal, the rest
extending from the lateral terminations of the latter upwards and out-
wards. In Dalmanites these pairs become confluent at the adjacent
terminations and form the grooves distinguishing the anterior lobe of
the glabella, so characteristic of that genus. The second set are also
horizontal, the inner ends being directed slightly upwards. The third
set separates the anterior portion of the glabella from the remainder,
extending across the axis as an indistinct shallow groove. Between
the third set and the well defined occipital furrow the glabella becomes
suddenly depressed and compressed laterally, forming a sort of pedes-

lOO

BULLETIN OF THE LABORATORIES

tal for the anterior portions of the glabella. The eyes are large. The
occipital furrow continues as a well defined groove along the pos-
terior margin of the head. The border anterior to the head is nar-
row. The character of the postero-lateral corner of the same is un-
known, but judging from the usual characters of the genus it was
probably slightly rounded and destitute of -spines. The facial sutures
follow closely the anterior outline of the glabella to the palpebral lobes,
from the posterior parts of these they proceed laterally, cutting the
lateral margins of the head a short distance above, the postero-lateral
corners. Viewed directly from the front the facial sutures are seen to
be slightly depressed along the middle of the anterior edge of the gla-
bella. The same is true of the adjacent rim of the head.

Length of largest specimen found, 6 mm ; breadth, about 9.6
mm. Length of glabella to occipital furrow, 5 mm ; greatest width,
5.7 mm, width just above the third set of furrows, 3.1 mm. Associ-
ated with these forms is a pigidium which is similar to that of Proetus
planunarginatus ^ Meek^ of Ohio Devonian strata, but which is placed here
both on account of its relative frequency at the Soldiers’ Home and
because other species, undoubtedly of this genus, possess similar
pygidia.

These pygidia are broad; the curvature of the anterior edge is
moderate ; the middle lobe is prominent and very convex, ending ab-
ruptly posteriorly; segments about nine in a well developed specimen,
each segment with a tubercle, these forming a median row. Lateral
lobes moderately convex, with seven or eight segments, becoming in-
distinct posteriorly. Segments all grooved along the middle, that part
of the pygidium which lies behind the termination of the middle lobe
does not show evident segmentation. Posteriorly the margin is thick-
ened along the edge of the pygidium, so that a groove is formed with-
in the posterior edge leaving a plane margin which vanishes anteriorly.

In Proetus planimarginatus the central lobe of the glabella has sim-
ilar groovings, but the postero-lateral margins are enlarged; there is no
flat border between its anterior margin and the groove running along
the edge of the head, the tubercles are also smaller and more nearly
rounded. The pygidia have the same general form and the same me-
dian row of tubercles along the middle lobe, but the groove extends
all around the lateral and posterior margin, and leaves a continuous
border, from which it derives its name.

OF DENISON UNIVERSITY.

lOI

Length of pygidiiim, 7 mm; breadth, 12 mm; width of anterior
portion of middle lobe, 4 mm, near the posterior termination, 2 mm 5
the marginal groove vanishes between the third and fourth segments
of the lateral lobes.

Name signifies small and beautiful.

Locality and posiimi. Soldiers’ Home Quarries. Confounded by
collectors with small specimens of Dalmanites Werthneri. Clinton
Group.

Genus DALMANITES, Emmrich.

XI. Dalmanites Werthneri, Foerste.

{Plate VIII, Figs. 22, 22a, 23, 24, 25.)

The figures of this species, omitted from the original description,
are added here, for readier determination.

Locality and position. Soldier’s Home Quarries, Clinton Group.

Genus ENCRINURUS, Emmrich.

XH. Encrinurus Thresheri, sp. n.

{Plate VHI, Fig. 26.)

Pygidium, on account of the great compression and depression
of the lateral lobes, is longer than broad. The general form is trian-
gular, highly arched along the entire length of the mesial lobe. Me-
sial lobe broad anteriorly, becoming gradually attenuated posteriorly,
crossed by segments, about 18 in number, becoming indistinct poste-
riorly. The segments are all more or less interrupted along the me-
sial line of the lobe, and beginning with the anterior segment, each
third segment is supplied with a tubercle, i. e, the segments, i, 4, 7,
10, 13 and 16. The suppression of the middle part of the anterior
three segments is less evident. The lateral lobes are marked by seven
segments. The anterior segments are directed laterally for a short dis-
tance and then are deflected in a broad curve to the rear. The posterior
deflection of the succeeding segments becomes more marked until the
seventh pair extends in a parallel direction backwards from the mesial
lobe. The inner terminations of the interrupted segments of the me-
sial lobes form low nodules, often indistinct. A similar set may some-
times be distinguished along the edges of the mesial lobe. The seg-

102

BULLETIN OF THE LABORATORIES

ments of the lateral lobes are narrower than the intervening grooves,
and supplied with three or four sets of indistinct nodules.

Encrinurus deltoideus^ Shumard^ from the Cape Girardeau Lime-
stone, Missouri, may be distinguished by its rounded extremity, its
greater number of segments (24) along the mesial lobe, and also along
the lateral lobes (8 segments). The segments of the lateral lobes are
twice as wide as the furrows between them, and are devoid of nodules.

Encrmurus nereiis^ Hall^ from the Racine beds of Wisconsin, may
be distinguished by the greater number of segments (8 or 9) on the
lateral lobes, as far as known not tuberculated ; judging by the figure
of the type specimen a raised narrow, but distinct ridge runs along the
lateral borders of the middle lobe.

Encriniiriis Americmms^ Fogdes, from the Clinton Group of Geor-
gia, may be distinguished by the smaller number of segments (6)
along the lateral lobes ; the segments are almost twice as broad as the
deep intervening grooves, are flat and even slightly grooved along the
top, and are destitute of nodules, as far as known.

Encrinurus elegantulus, Billings^ from the Anticosti Group of Can-
ada, may be distinguished by the greater number of segments (24)
along the middle lobes, the anterior 8 extending entirely across, the
rest being interrupted, the free mesial space without tubercles. There
are only 5 pairs of segments on the lateral lobes. They agree how-
ever in the origin of the segments of the lateral lobes, when compared
with the position of the segments on the middle lobe.

Encrinurus ornatus, Hall and Whitfield, from the Guelph lime-
stones of Ohio, may be distinguished (if the figures of the type speci-
men are correct) by the segments of the lateral lobes having a less
abrupt backward direction, and being all situated along the side of the
middle lobe (whereas in E. Tliresheri the seventh pair extend posteri-
orly from the same). The arrangement of the mesial tubercles along
the middle lobe is also different, being situated on the second, fifth,
ninth, thirteenth, seventeenth, and perhaps one on a later segment.
If now the tubercle on the second segment be omitted the remainder
are evidently seen to be separated each time by three segments ( instead
of by two as in E. Tliresheri).

Encrinurus punctatus, Wahlenberg, of Sweden and elsewhere in
Europe, may be distinguished, it is said, by a single row of nodes
along the middle of each lateral lobe (whereas the fourth segment of

OF DENISON UNIVERSITY.

103

the lateral lobes in E. Thresheri, shows 4 tubercles, and the anterior
segments probably presented more.

Encrmiirus punctatus^ Hall^ from the Clinton Group of New York,
if it be identical with Encrinurus omatiis, will of course be distin-
guished by the same characters as those mentioned under that species;
the number of tubercles or nodes in the New York and Ohio Clinton
specimens and the size of the pygidia, however, agree better than
when the pygidia of the New York and Ohio Guelph specimens are
compared. At any rate, the Clinton forms are distinct from the typi-
cal specimens of E. punctatus from Europe, and from the species de-
scribed as E. ornatus^ from the Guelph strata of Ohio.

Named after Mr. B. B. Thresher, of Dayton, in whose cabinet the
type specimen is found.

Locality and position. Clinton Group.

GASTEROPODA.

Genus BUCANIA, Hall.

Bucania trilobata. Hall.

{Elate VIII, Eig. 33, a, b.)

Shell convolute, volutions in the same plane, contiguous ; later-
ally compressed. Body of the shell strongly lobed, the dorsum being
laterally compressed and thus separated by a sort of groove from the
lateral portions of the volution, giving rise to one dorsal and two lat-
eral ridges or lobes. The form of the aperture is not seen in our Ohio
specimens, but would naturally conform to the trilobate structure of
the last volution.

Authors are inclined at present to abandon the genus Bucania,
and to place the forms referred to it among the Bellerophons. We
have seen fit to retain this name in this case purely as a matter of con-
venience. There is already a species called Bellerophon tiHlobatus, de-
scribed by Sowerby, in his “Silurian System”, a European form.
From this our form may be readily distinguished by the lateral com-
pression of its last volution. The European form on the other hand
has this volution decidedly flattened transversely, being elliptical in
section ; the middle lobe is comparatively much broader and not so
much elevated above the lateral lobes. Our specimen differs from the
New York types chiefly in size, being comparatively exceedingly small.

104

BULLETIN OF THE LABORATORIES

It may be noted, however, in this connection that it is associated with
a number of small fossils, which apparently are depauperate forms of
other, well-known species.

Locality and position. Beavertown marl, Huffman’s Quarry.
Clinton Group.

LAMELLIBRANCHIATA.

Genus PTERINEA, Goldfuss.

Pterinea brisa. Hall.

(Plate VIII, Fig. 30.)

Since [the description of the specimens from the Soldiers’
Home Quarries, a large number of quite perfect specimens have been
obtained from Brown’s Quarry, near New Carlisle. A very fine speci-
men, belonging to the cabinet of Prof. W. S. Hoskinson, is here fig-
ured.

They are all left valves. The body of the shell is obliquely sub-ovate,
extremely inequilateral; the anterior wing is rather long, and distinct-
ly sinuate at its junction with the body of the shell; the posterior wing
is acute and extends almost if not quite as far as the posterior extrem-
ity of the shell. The umbo is prominent, rising above the hinge-line.
The anterior wing is depressed antero-laterally along the hinge-line,
giving sometimes the deceptive appearance of a hinge-line strongly
bent at the beaks (as in figure 9, plate 28, Geol. Surv. Ind., Eleventh
Report). The surface is marked by numerous distinct radiating and
concentric striae.

Our specimens compare very well, as near as we can judge, with
the type figured from Bridgeport, Illinois. The Indiana specimens re-
ferred to this species have a comparatively greater width, measuring
vertically from the hinge-line; the concentric striae are usually in the
form of prominent lamellae, recurving at their edges, often fimbriated,
characters which our specimens never present.

Length of one of the largest specimens, measured from the umbo
to the posterior extremity of the hinge-line, 1 8 mm, to the posterior ex-
tremity of the body, 21 mm; width measured from the hinge-line ver-
tically, 14.5 mm.

Locality and position. Brown’s Quarry, Soldiers’ Home Quarries.
Clinton Group.

OF DENISON UNIVERSITY.

105

BRACHIOPODA.

I. Streptorhyncus tenuis,
II. Strophomena patenta,

HalL

Hall.

Genus STREPTORHYNCUS, King.
I. Streptorhyncus tenuis. Hall.
{Plate VHI, Fig^. 31, 32, 38.)

Shell quite large, semi-circular ; cardinal line less than the great-
est width of the shell, cardinal extremities rounded. Ventral valve
flat, the beak and immediately adjacent portions slightly elevated. In
the description of the type specimens this valve is said to be slightly
concave. Our valve can not be said to be anything more than flat.
Dorsal valve moderately convex, the umbo not prominent; convex-
ity, with the exception of a little compression near the cardinal ex-
tremities, regular.

Surface marked by numerous, rounded, radiating striae, somewhat
curved near the cardinal extremities; alternating with these are smaller
thread-like striae. These radiating striae are crossed by fine concentric
striae, presenting when magnified, a beautiful, rugose appearance.
Substance of the shell very thin.

One of the largest ventral valves is 30 mm. long, and 36 mm.
wide. Our specimens therefore do not attain the size of the Indiana
specimens. A dorsal valve is 22 mm. long, 30 mm. wide, and meas-
ures 26 mm. between the cardinal angles ; its convexity is about
3.2 mm.

Locality and position. This is quite a common species in one part
of the Soldiers’ Home Quarry. Clinton Group.

Genus STROPHOMENA, Rafinesque.

H. Strophomena patenta. Hall.

{Plate VIII, Fig. 34, 35, 36, 37.)

Leptsena patenta, Hall, 1S52, Pal. New York, Vol. II.

Strophomena patenta, Hall, 1859, 12th Ann. Rep. Cab. Nat. Hist, of New

York.

Strophomena euglypha, Roemer, i860, Sil. Fauna, West. Tennessee.
Strophomena patenta, Hall and Whitfield, 1875, Pal. Ohio, Vol. H.

Shell of moderately large size. At various stages of growth they

Io6 BULLETIN OF THE LABORATORIES

present a very different appearance, so as often to suggest distinct spe-
cies, as may be noticed by the following descriptions.

Ventral valve, length 6.7 mm, width 8 mm. Valve moderately
convex, the cardinal extremities compressed, umbo moderately promi-
nent. The corresponding dorsal valve is moderately concave, greatest
concavity near the beak.

Ventral valve, length ii mm, width 14 mm. Valve strongly con-
vex, especially at t'he umbo which is about one-third the distance from
the beak to the anterior margin ; the cardinal extremities compressed.

Ventral valve, length 15 mm, width 19 mm. Valve convex es-
pecially at the umbo, which is one-fourth the distance from the beak,
the anterior, lateral, and postero-lateral extremities flattened or com-
pressed. The corresponding dorsal valve is slightly concave, its great-
est concavity being about one-fourth the distance from the beak. The
cardinal extremities are quite flat.

Ventral valve, length 18 mm, width 24 mm. Valve with cardinal
extremities quite flat ; the regions about the umbo, which is one fifth
the distance from the beak, convex; moderately concave beyond the
centre, towards the anterior and lateral margins. These margins in
the dorsal valve are slightly convex.

.Ventral valve, length 25 mm, width 33 mm. Concave in general
with a convex umbo, whose greatest convexity lies at about one eighth
the distance from the beak. The dorsal valve concave with the ante-
rior and lateral regions moderately convex. This is of the form of the
New York specimens which formed the type of this species. These
never seem to arrive at the stage presently to be described; the stria-
tions are also coarser than those of the Ohio forms.

Ventral valves, length 28, width 35. Valves convex for about
half their length, the umbo being very close to the beak, beyond the
middle anteriorly and laterally they become strongly recurved, or
geniculate in some individuals. The corresponding dorsal valve is
moderately concave for half its distance, then strongly bent or genicu-
late for the remainder of the distance' towards the anterior and lateral
margins.

Shell marked by numerous, fine, radiating strise; in young speci-
mens certain of the striae at more or less regular intervals become
more prominent, in the typically strophomenoid manner. In older
specimens, the prominence of these striae no longer is sufficient to at-
tract attention, or is even entirely lost. After the removal of the thin

OF DENISON UNIVERSITY.

107

exterior crust, these striae often appear as radiating series of papillae,
especially prominent and distinct near the anterior and lateral margins.

Locality and position. Soldiers’ Home Quarries, Fauver’s Quarry,
Centreville. Clinton Group. Also in New York and Tennessee.

/

GRAPTOLITID^.

I. Dictyonema pertenue, . . . . n. sp.

II. Dictyonema scalariforme, . . . . n. sp.

Genus DICTYONEMA, Hall.

I. Dictyonema pertenue, sp. n.

{Plate VHI, Figs. 27, a, b.)

Frond infundibuliform, composed of numerous slender branches
connected at intervals by fine transverse dissepiments, thus forming a
fenestrated expansion. The branches are more or less cylindrical in
form, about .23 mm. broad, and from 1.3 to 2 times their own width
distant from another ; they increase by dichotomous division, adjacent
branches are parallel, about 9 branches occupying a width of 5 mm.
The dissepiments are very fine, about .025 mm. thick; owing to their
fineness they can not be readily discovered in all parts of the fronds,
nor can their arrangement be accurately determined, but on an aver-
age they seem to be about i mm. or slightly less apart. Non-cellulifer-
ous face marked by strong, short, curved striae, suggestion the appear-
ance of twisted strands. The celluliferous face has not been seen,
however abraded specimens frequently leave impressions of the cells
in the rock from which the following characters are drawn up. Cells,
circular at their apertures and protruded from the surface of the frond,
arranged in a single, straight series along the middle of the branches.
The cells are about .18 mm. in diameter, and a little more than their
own width apart, about 12 cells occupying a length of 5 mm. The
frond from which this description was prepared is a flabellate fragment
23 mm. in length.

The name signifies very slender.

DictyoneiJia pergracile., Hall and Whitfield., is described as a species
in which the branches do not exceed .5 mm. Our specimens are- orily
half that size, but since the minimum width in the Kentucky speci-

io8

BULLETIN OF THE ■ LABORATORIES

mens is not mentioned, this can not assist in the identification of our
specimens. However the branches of our specimens are not evidently
tortuous, nor are the fenestrules elongate hexagonal in form.

Dictyonema splendens^ Billings^ is said to have ‘ ‘ longitudinal
stems about one-third of a line wide, and about their own width dis-
tant from each other. There are five or six longitudinal stipes in the
width of two lines,” a very suggestive mathematical problem. Giving
it a fair interpretation, there are 5 or 6 branches instead of 8 in a width
of 2 lines, and the branches are probably somewhat broader than in
our own specimens.

In neither case is any mention of the cells made. All three forms
may eventually prove to belong to the same species. At present,
however, our form appears a well defined species with close and nar-
rower branches than any hitherto described.

Locality and position. Soldiers Home, near Dayton, Ohio. Clin-
ton Group.

II. Dictyonema scalariforme, sp. n.

(Plate VIII, Figs. 28, 29.)

Frond infundibuliform. Branches of medium size, from once to
twice their own width distant from each other, dividing dichotomously
and connected by transverse bars or dissipiments one-fourth or one-
third their width. The dissepiments are- stationed at unequal distances
from each other, varying from once to twice the distance between the
branches, and leaving quadrangular or oblong fenestrules between the
same. The celluliferous side of the frond has not been seen ; in places
however where the frond has been abraded the position and the fre-
quency of the cells is distinctly shown. Judging from this, they are
placed in a single row along the middle of each branch ; there are
about 13 cells in a length of 5 mm ; these cells seem to have an ob-
lique upward direction, consecutive cells leaning upon those in front
of them, thus forming a narrow ridge or keel ; at their tips the cells
seem to have become more or less free, and to have developed circu-
lar apertures. Non-celluliferous face striated obliquely by short, curved
striae suggesting twisted strands.

Frond here described, a flabellate fragment, 40 mm. long and 35
mm. broad. From 10 to 12 branches occupy a width of 10 mm, and
from 10 to 13 dissepiments occupy the same distance in length. The

OF DENISON UNIVERSITY.

109

branches where they are well preserved, are from .5 mm, to .65 mm.
wide. The dissepiments vary from .1 mm. to .22 mm. in thickness.

The name signifies ladder shaped.

This species is evidently related to Dictyonema retiforme. Hall., dif-
fering from the ?ame in the narrower branches being more compactly
arranged, the dissepiments likewise occurring at shorter intervals. Ac-
cording to Prof. J. W. Spencer the branches of D. retiforme are on an
average about one millimetre in width. The largest branches of our
specimens do not attain this width.

Locality and position. Soldiers’ Home, Clinton Group.

Graptolites of this genus usually appear as black strands on the
surface of the rock. In this connection it is interesting to note that
the cell walls of Stictopora gracilis, Spencer, present the same appear-
ance, momentarily suggesting a graptolite.

PLATE VIII.

Fig. I. Acidaspis Oidoni, n. sp; a head, anterior margin unknown.

Fig. 2. Proetus determinatus, n. sp; a glabella with part of anterior border.
Fig. 3. Proetus determinatus, n. sp; a glabella, with attached border and pal-
pebral lobe.

Fig. 4. Phacops ptilchellus, n. sp;. an associated pygidium.

Fig. 5. Proetus ; a glabella with anterior border and palpebral

lobe.

Fig. 6. Illcenus Daytouensis, Hall and Whitfield; rostrum in position, sharp
edged postero- lateral margins of movable cheeks broken off ; a, a movable cheek,
from Ludlow Falls.

Fig. 7. Illeenus Madisonianus, Whitfield; a glabella, very doubtfully referred
here.

Fig. 8. Illcenus Madisonianus, Whitfield; pygidium, with paraboloid outline.
Fig. 9. Illcenus Madisonianus, Whitfield; pygidium, somewhat broader.

Fig. 10. Illcenus Madisonianus, Whitfield; pygidium, semi-circular, not parabo-
loid .

Fig. II. A hypostoma, very doubtfully referred to some species of Illaenus,
Fig. 12. Calymene Vogdesi, n. sp; head of type S])ecimen.

Fig. 13. Calymene Vogdesi, n. sp; profile along the middle of the same.

Fig. 14. Calymene Vogdesi, n. sp; head of a younger specimen.

Fig. 15. Caly7nene Vogdesi, n. sp; profile along, the middle of the same.

Fig. 16. Calymene Vogdesi, 7t. sp; characteristic pygidium.

Fig. 17. Ceraurus ; a glabella.

Fig. 18. Lichas breviceps. Hall; a glabella, with part of a fixed cheek.

Fig. 19. Lichas breviceps, Hall; a hypostoma.

no

BULLETIN OF THE LABORATORIES

Fig. 20, Phacops pulchellus. n. sp; a glabella, with fixed cheeks.

Fig. 21. Phacops pulchelhis ., n. sp; a head, the cheeks on the right wanting.
Fig. 22. Dalmanites Wej'thneri^ Foerste; a head, the spines wanting ; a, a de-
tached spine, seen from below.

Fig. 23. Dalmanites Werthneri, Foerste; a pygidium.

Fig. 24. Dalmanites Werthneri., Foerste; an almost entire specimen.

Fig. 25. Dalmanites Werthneri, Foerste; an eye, magnified.

Fig. 26. E7tcrinurus Thres\eri, n. sp; a pygidium, figured a little too narrow.
Fig. 27. Dictyojiema pertenne, ;z. sp; a, a frond; b, part of the same magnified.
Fig. 28. Dictyonema scalariforme., n. sp; a frond.

Fig. 29. Dictyone})ia scalariforme., n. sp; a part of the same magnified.

Fig. 30. Pterinea brisa, Hall; a right valve.

Fig. 31. Streptorhyncus tenuis, Hall; a dorsal valve.

F'ig. 32. Streptorhyncus tenuis, Hall; a ventral valve.

' Fig. 33. Bucania tfilobata. Hall; a, a lateral view ; b, dorsal view ; both views,
X 5-

Fig. 34. Strophomena patenta. Hall; a ventral valve of a young specimen, with
no distinctly elevated beak, referred here.

Fig. 35. Strophomena patenta. Hall; a ventral valve of a young specimen of
the normal type.

F'ig. 36. Strophomena patenta. Hall; a ventral valve at an older stage.

Fig. 37. Strophomena patenta. Half a dorsal valve, the cardinal angles not
acute.

Fig. 3S. Streptorhyncus tenuis. Hall; a few of the radiating striae enlarged,
showing fine concentric striae.

Fig. 39. Ichthyocrinus sp; a fragment of the calyx. >

Figs. 40, 41. Bases of calyces of crinoids, of unknown relation.

Figs. 42, 43. Plates from calyces of ;in unknown crinoid.

Fig. 44. A specimen of unknown relation, probably a part of some crinoid!

III.

On the Determination of the Horizontal Component of the
Earth’s Magnetic Force.

BY L. E. AKINS.

The method I have used in the determination of H is the one
used at the University of Glasgow. The attractive feature of the
method is the simplicity with which the ratio of m to H, and the pro-
duct of mH are determined, where m is the magnetic moment of a
given bar magnet. The apparatus used is a small Bottomley magnet-
ometer and a deflecting bar magnet.

The cut, which is exactly one half full size, fully illustrates the
magnetometer, except that the needle needs a little explanation.
The one I used consists of two bar magnets about eight-tenths centi-
metres long and one-tenth centimetre wide, and as thin as the steel
can be conveniently worked, d'he magnets are fastened with shellac,
like poles together, to the back of a small mirror and suspended by a
single silk fiber as in the cut. I silver my own mirrors, using the short
process given in Roscoe’s Chemistry, Vol. II. With care in cleaning
and by keeping the glass quite warm while the silver is being precipi-
tated, a very good mirror can be obtained. The mirrors I used were
small microscope covers five-tenths centimetres in diameter.

The first experiment is to find an expression for ~ which is

accomplished as follows. The magnetometer is set up so that its nee-
dle is in the magnetic meridian of the place and its centre directly
over the point where a line, exactly at right angles to the N. and S.
line, cuts that line. A very convenient arrangement for this consists
of two boards, each eight inches wide, one five feet long, the other

II2

BULLETIN OF THE LABORATORIES

three, put together in the form of a cross, with the middle of the short
board about forty inches from one end of the long board. The boards
should be carefully halved together and be exactly at right angles to
one another. This cross is mounted on a stand so that it' can be easily
turned in azimuth, and so that the longer part stands nearly east and
west. The magnetometer is now placed in the middle of the short
arm and adjusted so that the middle line of the short arm and the mid-
dle line of the long arm of the cross, exactly at right angles to the
former line, intersect directly under the centre of the needle. A scale
and lamp should now be arranged in front of the magnetometer, with
the scale supported by the longest arm directly in front of the magnet-
ometer, parallel with the line on the short arm and distant one hundred
centimetres from the needle. The middle of the scale should be di-
rectly over the middle line of its arm. The lamp is placed in front of
a hole cut in the scale support directly under the centre of the scale.
The light from the lamp is thus reflected back upon the scale. Now
turn the cross till the spot of reflected light falls directly on the centre
mark of the scale. The instrument is now in its proper position
for use.

I find that with a plane mirror I can get the best spot of light by
using two lenses, one of long focal length, placed close to the face of
the mirror and one of comparatively short focal length placed close to
the aperture in the scale support. To obtain a dark line across the
spot of light, I place a very fine wire between the two lenses and move
it back and forth till the mark is sharply defined across the spot.

The deflecting bar magnet is now placed, end on, in the east and
west line, with its centre forty centimetres distant from the needle and
the deflection of the spot of light noted. Then the magnet is placed
on the opposite side at same distance and deflection noted. If all the
adjustments are perfect, these two deflections will be equal ; but the
mean of them will give nearly enough the true deflection. All the
measurements being made with the same unit, the number of scale di-
visions divided by distance of scale from mirror gives tan 2a; where a
is the angle of deflection of the mirror.

If r is the distance of centre of magnet from the mirror, 1 the
half length of the magnet, m the magnetic moment of the mag-

m (r2 12 )2

net, H the horizontal component, then = - — Tana(i)

The magnet may also be placed in the north and south line, side

OF DENISON UNIVERSITY.

II3

on, and deflections taken ; then, r. 1. a. m. H meaning same as before,
{r2 + 12 ) =>-2 Tan a. (3)

The magnetometer is now removed, and the bar magnet sus-
pended by a single fiber of silk, where the magnetometer stood.
The ingenuity of the experimenter will best find a way for doing this.
It is well to fasten a very small mirror to the suspension fiber, so
that the period may be observed from the reflected light on the scale.
The fiber in this case should be as long as possible to make the error
due to its torsional rigidity as near a minimum as possible. If the
fiber be twenty centimetres long, the error will be so near to zero as
not to practically effect the result. The equation Mr. Gray gives

for the determining of T in terms of m and H is -f — ^ a = o

where N is the moment of inertia of the vibrating system. The
solution of this equation can be found in Williamson and Tarlton’s
Dynamics, art. 107. ; or in Dynamics of a Particle by Tait and Steel,

art. 88. From this T = 2 ii ^ ^^^r magnets one tenth centi-

metre in diameter N =

W 12

where W is the weight of the magnet

in grammes. Therefore m H = ^ (3) Combining this with

, o Il2 12 r w , . , Il2 12 w

(I) H2 = 8-3 /..o T7 NO and with (2) H2 = 4-:

T2 (1-2 -12 )2 Tan a

(r2 4- 12 ) 3-2 T2 Tan a

The measurements should all be in the metric system and then
the value of H is given in c. g. s. units. I find that magnets for de-
flectors made from No. 18 knitting needles and ten centimetres long
give the best results. If wire of a larger diameter is used, a more
complicated formula must be used, involving the moment of inertia of
a right cylinder about an axis through its centre of gravity and perpen-
dicular to its own axis. The length 1 is the measured half length of
the bar magnet. Mr. Gray gives a method for determining the actual
effective length of the magnet; but I have not used it. Corrections
also might be made for atmospheric resistance to the vibrator, change
of length due to change of temperature ; but these are so very small
that, for practical purposes, they may be neglected.

The angle 2a should be so small that Tan a—yi Tan 2 a. This
will avoid much labor in making computations.

As the mean of a considerable number of experiments I find for

I 14 BULLETIN OF THE LABORATORIES

H in my study the value .19707 c. g. s. units. Of course the value is
always modified by the presence of iron, and I could not eliminate
errors resulting from that.

The following from my results of Mar. 28 will help to illustrate
the method used :

SIDE ON.

Magnet

Mar

Tan. 2a

Tan. a

1

r

T

W

H

A

28

19*5

1000

.00975

5

35

4.16

.8765 gr.

.1989

B

28

20. 125

I coo

.01007

5

35

4.08

.8682 gr.

.1963

C

28

13-875

1000

.00694

5

35

4.706

.8745 gr.

.1987

D

28

1975

1000

.00988

5

35

4.285

9255

•1953

For further explanation the student is referred to Mr. Gray’s book.
I make no claim to originality. I have only followed as nearly as
possibile the directions given there. I have been so pleased with the
method that I have thought others might be induced to try it.

*The symbol Pi is represented by il throughout.

IV.

LIST OF ALG^F.

BY H. L. JONES.

The following list of Algae is made up from specimens collected
at the Licking Reservoir and from ponds in the vicinity of Granville.
Only a very few of the most common species are here given, with the
exception of the desmids, the list of which is somewhat more com-
plete.

Spirogyra Weberi, Ktz.,

Spirogyra insignis, Ktz.,

Scenedesmus polymorphus. Wood,

Scenedesmus quadricauda, Breb.,

Pediastriim

simplex, Meyer,

Pediastrum

Ehrenbergii,

A. Br.,

Pediastrum

Boryanum,

Turpin,

Pediastrum

angulosum.

Menegh.,

Cosmarium

Brebissonii,

Menegh.,

Cosmarium

contractum.

Kirch.,

Cosmarium

Seelyanum,

Wolle,

Cosmarium

intermedium

, Delp.,

Cosmarium

Botrytis, Menegh.,

Cosmarium

latum, Breb.,

ii6

BULLETIN OF THE LABORATORIES

Cosmarium Broomei, Thwaites,

Cosmarium orbiculatum, Ralfs,

Cosmarium Ralfsii, Breb.,

Cosmarium tinctum, Ralfs,

Cosmarium biretum, Breb.,

Micrasterias truncata, Ralfs,

Desmidium Swartzii, Ag.,

Sphaerozosma filiforme, Rab.,

Closterium moniliferum, Ehrb. ,

Closterium Dianse, Ehrb. ,

Closterium parvulum, Naeg.,

Closterium strigosum, Ehrb.,

Closterium lineatum, Ehrb.,

Staurastrum polymorphum, Breb. ,
Staurastrum pseudopachyrhynchum, Wolle,
Staurastrum inconspicuum, Nord. ,
Staurastrum anatinum, Cooke and Wells,
Dociduum Trabecula, Naeg.,

Euastrum elegans, Breb. ,

Euastrum rostratrum, Ralfs,

Ktz. — F. T. Kuetzing; Breb. — A. de Brebisson ; A. Br. — Alex. Braun;
Menegh. — J. Meneghini ; Kirch. — O.Kirchner; Delp. — J. B. Delponte ; Ag. —
C. A. Agardh ; Naeg. — C. Nageli ; Nord. — O. Nordstedt.

Bullatin nf ths LabnratnriBs nf Benisan Univarslty,

IZ-Ql. II,

PLATE I.

Bulletin ef the Laberaterles ef Benisen University,

Uel, II,

PLATE II,

HullBtln nf the Laharatariss af IlBiiisDii UnivBrsity,

ITbL II

FLUTE III,

HullBtiii nf the LabnratnriBS of DBnlsan UnivBrsity,

PLATE III,

BullEtln nf the Labarataries of BEnisan UnivErslty.

ITeL II.

PLATB IT.

BullEtiii of tha LabaratorlBS of BEnlsan UnivErsity,

Hal, II,

FLUTE HI,

-Vol, II,

BullEtin □! the Labaratariss of Benisan UnivBrsity,

PLilTE BII,

I

CUu\.T. TtruUU, cui.

Bull, Lali, Ban, Unlv,

Vnl. ii:

PLITE ¥IIL

' Bull B tin nf tliB LaboratBriEs of Banlsan UnlvBrsity,

■BbL II,

MA GNETOMETER.

FLUTE IX.

BULLETIN

OF THE

SCIENTIFIC LABORATORIES

OF

DENISON UNIVERSITY,

EDITED BY

C. L. HERRICK, Dep’t. of Geol. and Nat. History,

AND

A. D. COLE, Dep’t. of Chemistry and Physics.

VOL. II, PART 2.

GRANVILLE, OHIO, APRIL, 1887.

SWf? f, V w

‘ 'I-'

1

'.‘ : I

1

... ... :^^;'

, ' . • •' ‘*’
>'. , C ■ , ••'■; . '4'^,

Ku-: .y- f •■

.\.c

'13

V.' ’/ '

]'\--\A^i

U-::'-

m:

r-- '■■■’

^'7 A;

--A..”

'. ...J

>'S«5 .i

i'..* t •*'■■' “

!'•

,1V,

'<■( >

, \

■ ■J,'

‘ .-..v

V.

GEOLOGY AND LITHOLOGY OF MICHIPICOTEN BAY.

Results of the Summer Laboratory Session of 1886.

C. L. Herrick, W. G. Tight, and H. L. Jones.

\Read before the Denison Scientific Association, April 23, 1886.]

The excursion was undertaken with a view primarily to the en-
largement of the working series of crystalline rocks in our cabinet and
in the hope of affording a useful supplement to the class-work in lith-
ology, though it fell to the lot of but few of the class to participate in
it. It is hoped that these peripatetic summer training classes may be-
come a valuable adjunct to the regular work so long, at least, as we
have, as now, numbers who expect to work as scientific specialists.

The party left the Sault Ste. Marie, on the little steamer Remora,
and arrived at the fishing station near the mouth of the Dog River, in
Michipicoten Bay, at 4 o’clock in the afternoon when, by the kindness
of the agent, we were promptly transported to our permanent camping
station on the left bank of the Dog River at its mouth. Here a tem-
porary laboratory was located, and by means of oars and sail much of
the adjacent coast was carefully studied.

Those not particularly familiar with recent geological literature
may ask why this special locality was chosen for the summer’s work
and what is the nature of the problems whose solution was sought.
To properly answer these questions would be to review in great part
the writings of most of our leading geologists during a period of many
years, especially those of Canada, Michigan and Wisconsin. Such
an extended review is, however, rendered unnecessary by the fact that

120

BULLETIN OF THE LABORATORIES

several of the recent writers on the geology of Lake Superior have
given such collations and discussions from their several points of view,
notably Wadsworth, in “The Azoic System and its subdivisions”,

1884, and Irving, in his “Copper-bearing rocks of L. Superior”,

1885. Recent discussions may also be found in the Annual Reports
of Minnesota. In the region in question the geological relations ap-
pear to be relatively simple, but at the same time so intimately associ-
ated with the more intricate regions now chiefly under discussion as to
make any conclusions which can be reached of considerable value.

In general then, the region northward from L. Superior is a part
of the great V-shaped area of crystalline rocks classed as Azoic and
usually grouped in two great series, the one largely composed of
gneisses and granites and called Lawrentian, and the other, assumed to
be higher (and hence later) composed of crystalline slates and schists.
This whole series is supposed to consist of altered sediments, but with
an unconformity between the two groups. The evidences of life are
restricted to those furnished by the exceedingly problematical Eozoon
and the presence of graphite and iron. The original name given to
both these members was the term Azoic, applied by Foster and Whit-
ney, in 1850. Whitney and Wadsworth vigorously assert that there
exists no reason for changing this name (as to Archean) or subdividing
the series (into Lawrentian and Huronian). The Canadian geologists
claim that the Huronian schists are constantly unconformable to the
underlying Lawrentian and frequently contain pebbles from it. To
this Wadsworth and Whitney reply that there is a lack of observation
to substantiate the claim of unconformability and that the pebbles are
high in the series of the Huronian and not in any sense basement con-
glomerates. At page 557 of the “ Azoic System,” these authors seem
to imply that the Huronian conglomerates are formed by the imbed-
ding of matter ejected in a fragmental state in a detrital magma.

In the region under consideration a further difference of opinion
seems to prevail. Irving, in the map of L. Superior, given in his val-
uable report on the “ Copper-bearing Rocks,” marks all the granitic
areas as Lawrentian and the schists as Huronian, while the Canadian
geological map indicates all the granite areas near the lake and associ-
ated with the schists as eruptive, although a region to the north is cov-
ered with the Lawrentian. In the sequel the evidence which leads us
to accept the conclusions of the Canadian geologists as to this particu-
lar region, is reviewed in detail so far as our material warrants.

OF DENISON UNIVERSITY.

12 I

The most detailed account of the relations between the schists and
granite seems to be that of McFarlane, who says: “The manner in
which these Huronian rocks adjoin those of the Lawrentian series may
be observed on the north shore between Michipicoten Harbor and
Island. I paid some attention to that point of junction which lies to
the west of Eagle R. , the precipitous cliffs to the east of which consist
principally of diabase schist and greenstone slate. A few miles to the
west of these cliffs and at a point bearing N. 29°, 5° E., from the east
end of Michipicoten Island, the Lawrentian granite is penetrated by
enormous dykes of dense basaltic greenstone (having the peculiar
doleritic glitter when fractured) which contain masses of granite.
This greenstone is also seen in large masses, which can scarcely be
called dykes, overlying the granite and enclosing huge masses of that
rock, one of which I observed to be cut by a small vein of the green-
stone. From this point to the Eagle R. these two rocks alternately
occupy the space along the shore, seldom in such a manner as to show
any regular superposition of the greenstone on the granite, but almost
always more or less in contact with each other. The greenstone how-
ever, becomes more frequent towards the east and at Eagle R. it has
almost replaced the granite, and assumed a lighter color, and an ir-
regularly schistose structure. The strike of these schists is at places
quite inconstant ; they wind in all directions, and what appear at first
sight to be quartz veins accompany their contortions. On closer in-
spection, however, of the largest of these, they are seen to be of gran-
ite, but whether twisted fragments of that rock or really veins in it, is
at first glance very uncertain. ^ ^ ^ Although they are seldom

or never angular they can scarcely be regarded otherwise than as frag-
ments whose shape has been modified by contact with the greenstone.

* * * Either the granite forms veins, penetrating the schistose

greenstones, in which case the latter are the older rocks ; or it is in
the form of contorted fragments, in which case the enclosing rock
may be of eruptive origin. The latter supposition seems to be most in
harmony with the facts stated.” (Rep. Progress 1863-66.) Com-
menting on this account Whitney and Wadsworth remarked: “It
seems almost incredible that a geologist, who professed to be a litholo-
gist, should have been unable to ascertain the relations and relative
age of these rocks when so many excellent exposures were observed,
as he states. His observations show clearly that both formations here
are eruptive and of the same geological age.” (Azoic System, p. 346.)

122

BULLETIN OF THE LABORATORIES

In the light of the facts presented beyond it seems that the danger is
sufficiently obvious in attempting to generalize on the basis of observa-
tions covering a portion of a district and still farther of dogmatizing
on the basis of such a description as the above. In the first place our
study makes it appear that McFarlane, in his hasty examination, failed
to distinguish between the dykes and bosses of eruptive diabase, which
break through the granite as well as the schist, and the metamorphosed
schist itself. Having made this strange error, consistency required
that the obviously stratified schists should be also included, so it be-
came easy to consider the trap as a phase of the schist, all being neces-
sarily eruptive. Had he gone five miles farther east he would have
encountered schist conglomerates with water-worn bowlders of gneiss,
etc., and would have found it necessary to include them also in the
the curious group of igneous rocks which he calls greenstones. The
confusion above referred to is the more strange because at this point
there is actually no difficulty in distinguishing the eruptive granite
from the eruptive trap and the metamorphic schist. At other places
all the explorer’s acumen and care is taxed to distinguish the schists
from the dyke-matter, there having been extensive interaction between
them. It would seem that from the above statements it should be ob-
vious that a careful and detailed study of even a limited area might
serve a better purpose than a cursory examination of a large field.
With this in mind the short time at our disposal was employed in care-
fully working out the details of the geological structure of a small area
about Michipicoten bay where, fortunately, a very considerable varie-
ty of rock may be encountered within easy distance. Judging from
the brief accounts of this region published, we expected here to find
the three formations in doubt in close juxtaposition. Pitching- camp
at Dog river, the coast was explored foot by foot in each direction as
time permitted, while excursions into the interior enabled us to ob-
serve the substantial uniformity of strike and texture for several miles
inland. We proposed to ourselves the following questions: (i)
What distinct formations may be recognized, both lithologically and
stratigraphically ? (2) What is the relative position and age of each ?

(3) What has been the source of the material and what the circum-
stances of deposition ? (4) What alterations in composition and posi-
tion during the subsequent changes? (5) How may the present to-
pographical features be explained ?

It soon became evident that we had to deal with three easily rec-

OF DENISON UNIVERSITY.

123

ognizable and distinct classes of rock which, in this region at least,
show no sign of interblending. The first, consisting of slaty rock,
inclined at a high but varying angle and reposing upon an evidently
igneous mass of granite which frequently projects through the slates
where denudation has removed them. The third series occurring only
as a thin belt for a short distance near cape Cargantua, consists of
conglomerate and sandstone which laps unconformably upon the slates
and is largely re-enforced by igneous overflows and intrusive masses
and forms the entire island of Michipicoten.

We first directed our attention to the series of slates which varies
sufficiently lithologically to afford much field for conjecture. First,
does the cleavage really indicate sedimentation, or is it the result of
metamorphic action on an igneous rock ? We were fortunate in light-
ing upon the spot of all others most decisive on this point. It was
easy to convince ourselves that the cleavage followed closely the sedi-
mentation planes, for the lithological character of adjacent bands is
sufifciently distinct to prevent mistake. The occurrence at more or
less regular intervals of beds of conglomerate altered to schist-con-
glomerate, was especially decisive. These broad bands containing
large boulders as well as pebbles of granite and felsite-porphyry, pre-
serving their water-worn outlines and even jointage planes extend for
miles along the line of strike. The only stratified granitic rocks seen
were calcareous gneisses interlaminated with the schists near what is
assumed as the core of a great fold and thus representing possibly the
extreme of metamorphism.

Before proceeding to a discussion of the individual exposures the
first may be analyzed as follows : I. Greenish, more or less unctuous
slate varying to mica schist or hornblendic schist, always with more or
less calcite and chlorite. Although adhering to one facies it is greatly
influenced by the three classes of intrusives with which it is in various
places interbedded.

I. The most distinct of these groups of intrusives is made up of
diabases and diabase porphyrites which perforate the granite and in-
tersect the schists in the planes of strike and dip. No difficulty ever
exists in determining the contacts of these dykes. The aphanitic mar-
gins nearly always present sharp lines of contact. In some cases (as
No. 1108) the dyke-rock embraces fragments of granite and wraps it-
self about the altered fragments.

124

BULLETIN OF THE LABORATORIES

2. Rocks having the composition of mica-diorite or diorite, but
containing much calcite. Rocks of this group tend to assimilate
closely in appearance and structure to the schists in contact and sug-
gest the possibility of their having been the products of metamorphism
•of the schists themselves again altered by slow metasomatic
changes. A circumstance greatly favoring this theory is the fact that
the dykes in the underlying granite are always diabases so far as ob-
served while the diorites are very frequent in the schists. That the
contact action of the granites was amply sufficient to produce such
fusion is abundantly demonstrable.

4. Orthoclase and quartz-orthoclase felsite-porphyries occurring
under two conditions, but generally in such a way as to suggest an ex-
traneous origin of the porphyritic ingredients ; first, contacts of con-
glomerates with dykes of diabase or of diorite, second, interbedded
layers in the schist with adjacent alteration and veiny structure. We
incline to the belief that the greater part of the porphyry can be
traced directly to metamorphism in such conglomerates induced by
adjacent later eruptives.

Having thus briefly disposed of the two older groups we will now
consider the relation of the third or Keweenawan series to these.
The direction of the strike and dip of these series on Michipicoten
Island and Capes Choyye and Cargantua, furnish the only data on
which to base our conclusions. The strike on Michipicoten Island
appears to be in general a little N. of E., varying from the E. end of the
island to the W. end, toward the west end becoming more northerly.
At cape Choyye the strike seems to be in a direction a little W. of S.,
while at cape Cargantua it extends in almost a southern direction, va-
rying a little to E. This would seem to indicate that the older rocks
upon which the Keweenawan rests formed a synclinal with its axis in
a N. E. direction. The position of the granite rocks on either side of
this axis would indicate a synclinal rather than an eroded anticlinal,
as is the general rule. Also the fact that the Keweenawan is deposit-
ed within the basin itself and its margins abutt against the high cliffs
of the eroded older rocks. The relation of the basement conglomer-
ates exposed at cape Choyye to the older series will be discussed upon
a later page. The most complete discussion of the Keweenawan is
that of Prof Irving, in his monograph of the Copper-bearing
Rocks of Lake Superior. We may now proceed at once to a

OF DENISON UNIVERSITY.

125

Description of the Rocks of Michipicoten Bay.

It has been thought best to present these descriptions in about the
order in which they were examined by us, in order to place the reader
as nearly as possible at the same standpoint in regard to the questions
under discussion.

At the mouth of Dog river and extending along the coast for some
miles is No. 1001. Typical chloritic slate, strike S. 32° E., dip 80° N.
E. Very fissile and somewhat unctuous. Under the microscope, the
magma is close-grained, with much chlorite, irregular scales of biotite,
large irregular grains of calcite, occasional fragments of orthoclase,
fewer quartz grains, numerous crystalline grains of magnetite, and
some irridescent white scales which may be talc. The calcite, which is
characteristic of most of these schists, is here frequently granularly
decomposed in the centre of the grain. It is easily recognized
even in small grains by its irridescence and in larger ones by the rhom-
bohedral cleavage and twins.

Nos. 1005-1007. Same slate as No. 1001, but modified by con-
tact with dyke of No. 1004. The surfaces of the lamellae are covered
with wavy ridges arranged in ‘^cohesion figures.” The dark ingredi-
ents are collected in zones of varying width. Grains of orthoclase
and plagioclase* occur as well as quartz, which last in some cases is sur-
rounded by a zone of radially arranged fibres or plates of chlorite.
The calcite is also collected into zones. In one place (No. 1007) in
proximity to a quartz vein the rock is largely made up of rather regu-
lar though decomposing feldspar, chiefly orthoclase in Carlsbad twins.
The contact with the quartz is sharp, but the latter is permeated at the
edges by calcite and into it are fused iron globules from the schist.
Both these circumstances give evidence of high temperature during
the formation of the vein.

At the point one half mile east of Dog river is a wide band of
conglomerate (No. 1023 see beyond) passing which, we encounter
broad bands of yellowish felsite-porphyry and obliquely arranged len-
ticular masses and strings of a similar character (Fig. 5, Plate XL )

No. 1008 is a specimen from the lenticular masses and consists of
an exceedingly fine-grained felsitic magma, containing large rounded
grains or nearly perfect crystals of quartz and feldspar, (Plate XI, Fig. 2.)
The grains of quartz, though greatly rounded, appear to have been
doubly terminated crystals, while the feldspar, which is nearly all or-

126

BULLETIN OF THE LABORATORIES

thoclase in Carlsbad twins, is more frequently fractured than rounded
and is often filled with tongues of interpenetrating magma. This
magma is beautifully fluidal, the dark ingredients (biotite, chiefly al-
tered to chlorite) are scattered in crevices of the feldspars or sheltered
spots behind them where they have drifted like float-wood.

No. 1009, from the bands, is essentially similar, but is much finer-
grained and has fewer and smaller porphyritic ingredients. There are
mica rosettes and groups of magnetite, pyrite, apatite and other acces-
sories, as well as veins of calcite. •

No. loii. Chloritic schist one-half to three-fourths of a mile N.
E. of Dog river. It is greatly contorted, unctuous, containing large
quantities of calcite in the form of veins which conform to the contor-
tion. Microscopically it appears to be composed of a ground mass of
chlorite scales which when reduced to very thin sections lose their po-
larization colors and pleochroism. This ground mass is filled with
large crystals of much altered orthoclase, which have a tendency to
aggregate at 90° to axis c. The titanic iron shows all the gradations
to titanite. Large calcite grains showing characteristic cleavage in
three directions, with banded structure. The crystals of apatite pene-
trate all the ingredients of the rock. The rock appears to be much
altered from the influence of the interpenetrating diabase dykes.
Here as in other places it seems as if the interpenetrating dykes com-
ing through the primitive schists had fused the lower portions which
oozed up along the sides of the dyke and in cooling formed the more
coarsely crystalline rock No. 1012. (Plate XII, Figs, i, 2, and 3.)

No. 1012. Dark gray, coarse grained, unevenly fracturing rock,
intersected in all directions by veins of various minerals. Microscop-
ically it appears coarsely crystalline, with orthoclase and plagioclase
magma. The rock contains a considerable amount of biotite, some
calcite and a very few grains of hematite, with crystals of apatite scat-
tered through it sparingly. It appears as if this rock was the slowly
cooled product of the fused lower portion of the schists in which mica
and plagioclase have crystalized out. This all, apparently, through the
influence of the dyke which comes up through this boss and forms
No. 1013.

No. T013. A fine grained dark rock presenting all the characters
of a typical diabase. The line of contact with No. 12 is very sharply
marked.

OF DENISON UNIVERSITY.

127

Next, passing up Dog river about one-eighth of a mile from
its mouth, we encountered a large dyke 15-20 feet in width. No. 1017,
which in microscopic section presents all the characters of a typical
diabase similar to the other dark, fine-grained dykes. Its feldspars
consist of oligoclase with an angle of about 26° and labradorite with
an angle of about 48°. Some magnetite, otherwise very free from ac-
cessory ingredients. Adjacent to this dyke is the indurated slate
forming No. 1018, finely crystalline, containing large quantities of
brown mica in scales in O plane, also many irregular grains (Plate XII,
Fig. 5 A), and grains of magnetite broken up into fine powder, also a few
calcite grains, showing characteristic cleavage. The mica appears to be
decomposing to chlorite, forming a chlorite and. quartz basis. Pseu-
.domorph crystals of chlorite after mica are seen (Plate XII, Fig. 5B.)
Passing farther up the river the slate becomes porpyritic for a consid-
erable thickness.

No. 1019 is a sample of this porphyry. It has a very fine quartz
magma, with brown mica. The orthoclase crystals have more or less
regular crystalline outlines and its general appearance is strikingly sim-
ilar to that of the pebbles in the conglomerate No. 1023. In close
contact with this porphyry is No. 1019a, a dark very fine grained typi-
cal diabase. Its relation to No. 1019 is shown in Plate XI, Fig. 6. It
appears from the relations as if the porphyry (No. 1019) was
once continuous with the conglomerate No. 1023, which is found a
little farther up the river, but has lost its conglomeritic structure and
suffered the complete fusion of the pebbles and schist through the in-
fluence of this dyke No 1019a.

No. 1023 is the band of conglomerate at lower Denison Falls,
where it is from 39-75 feet in width. Its ground mass, which is near-
ly similar to the adjacent schist, is filled with water-worn pebbles of a
porphyritic rock No. 1023a. (See Plate XII, Fig. 9.)

No. 1023a. These pebbles have a sharp outline and can be per-
fectly separated from the 'ground mass. They show unmistakable evi-
dence of the action of water in rounding their corners and angles be-
fore their deposition. They also show the jointage planes of the prim"
itive rocks from which they were derived. Their general external ap-
pearance is about the same, but under microscopic examination of a
large number of slides it is clearly shown that they consist of two dis-
tinct rock species. This distinction is well marked, for there is shown
no gradation from one to the other, even in pebbles which are only an

128

BULLETIN OF THE LABORATORIES

inch or two apart and which must have been subjected to the same
agencies of metamorphism. One of these species presents all the
characters of a typical granite with much quartz and orthoclase and few ac-
cessories. There is some pyrite, probably secondary. The orthoclase
is much altered and gives aggregate polarization. The quartz grains
are filled with numerous fracture lines and are rendered almost cloudy
with microlitic inclusions, both apparently the result of intense heat
and pressure. The other variety is unmistakably porphyry, with an
almost irresolvable ground mass of quartz filled with large crystals of
orthoclase, with now and then a large grain of quartz. These pebbles
also appear to be very much altered from the action of heat. The or-
thoclase still can be determined by its aggregate polarization, crystal-
line outline and perpendicular extinction. In microscopic characters
this rocks resembles very closely the porphyritic phase of the schist
further down the river. A mile or so above the falls is a shining, fis-
sile chloride schist (No. 1027) which under the microscope proves to
have a very uniform ground-mass of quartz and chlorite with a very
little brown mica and numerous and regularly distributed minute un-
terminated crystals of an orthorhombic mineral with optical characters
of staurolite. Much of the schist is of a highly metamorphic charac-
ter, but preserves the’ usual strike and dip.

Nos. 1.016, 1029, T031, and 1036 are various phases of gneiss ex-
tending from a point one-half a mile east of the union of Mountain
river with Dog river, in the line of strike, to intersect the coast several
miles northeast of the mouth of the latter. This series consists of
several bands of varying width and texture interstratified and conform-
able with the schists. No. 1016 occurs along the shore near the Terraces,
forming high bluffs. It is a very fine-grained dark gneiss, with obvi-
ous bands of flesh-colored feldspar. Microscopically the mass of the
rock is composed of much green muscovite mica, considerable epi-
dote in zones (recognized by its bright yellow color,) relatively large
amounts of oligoclase and decomposing feldspathic ingredient (ortho-
clase). There are innumerable needles of a transparent substance ap-
parently derived from the mica. Some calcite is probably derived
from the same source. Very little quartz is present.

No. T036 is identical with No. 1016 and is from an adjacent ex-
posure, but it is nearly schistose and the section exhibits a few veins

OF DENISON UNIVERSITY.

129

of amorphous substance full of minute needles (sillimanite ?) like those
above mentioned.

No. 1031 is the same gneiss where it intersects Mountain river.
Here it is somewhat coarsely granular, containing more orthoclase and
biotite mica. There is some (perhaps secondary) quartz in the confused
portion. The transition to the schist is here very readily seen, there
being no unconformity.

No. 1029 is a phase of No. 1031, just at contact with the schist
and partakes of its characters. It has biotite in large quantities in
conspicuous masses surrounded by irregularly disposed augite grains.
The most of the remainder being plagioclase and orthoclase, with
some quartz and an occasional large grain of calcite. The augite is
very brilliantly polarized, but chiefly in grains or much broken crystals.

From the above it may be gathered that these gneissic rocks form
really an integral part of the schists, being more highly metamorphosed
than they. We incline to regard them as the axial part of the fold,
the strata repeating to all appearances on either side, as indicated in
our diagram. The relation of the strata is such as to permit us to
consider the schist conglomerate a true basement conglomerate.

Passing beyond the gneiss the same series seems to be repeated
in reverse order, though more careful examination is needed on this
point.

No'. 1037 resembles closely 1009 and is followed by No. 1038,
which is identified with the conglomerate No. 1023. This is followed
by schists. The contact of these schists with the granite is very sug-
gestive. At a little distance from the contact, the schist (No. 1045) is
a shining green chloride mica schist, with light specks scattered
through it. Under the microscope it is seen that the green mineral is
arranged in wavy bands separating aggregates of quartz in a finely
granular condition with large porphyritic brown grains, seemingly ag-
gregates. Close examination shows however that the brown granular
appearance masks calcite, with its cleavage and irridescence, and a
comparison with the part more nearly adjacent to the granite shows
the brown grains to have been feldspar from the latter.

No. 1046 is on the granite side of the contact and is an altered
granite, having the quartz and feldspar imbedded porphyritically in a
magma like that of the schist. The orthoclase is much altered by heat
and the crystals are margined by calcite. The quartz is less fractured
than in 1045, but on the whole the two are much alike. The original

130

BULLETIN OF THE LABORATORIES

crystals of biotite (?) are broken up and greatly altered. The unal-
tered granite (No. 1042) is very coarsely granular and is perforated by
many diabase dykes having the same general strike as in the schist.
The granite continues to Little Bear river and thence to Dore^ river,
to the east of which a chloritic slate appears. The strike is S. 50° E.
with a dip toward the southwest of about 45°, though the strata are
very tortuous and embrace included masses. The contact with the
granite is here as elsewhere evidence of the eruptive nature of the
granite. Irving’s map does not correctly represent the distribution of
the granite in this bay. Gros Cap is the promontory west of Michi-
picoten harbor and is said to bear hematite veins. Bell says it is
composed of slaty diorite, though the only rock seen by us was a
tough silicious chlorite schist. At Michipicoten river the rocks are
said to be dark hornblendic mica schist.

Leaving Gros Cap we crossed the entrance to Michipicoten har-
bor and encamped upon a narrow beach nearly directly south of the
point. The rock here is strongly tortuous and confused. Much of
the rock is porphyritic in a grayish-green base, while other portions
are of dense close texture and uniformly micro-crystalline. In one
place beneath the water the porphyritic rock could be seen to contain
large rounded masses of a different color, often a foot or more in di-
ameter. These were supposed to be similar to' the conglomerate peb-
bles of the west side. As typical of much of the un porphyritic rock
of this shore we select No. 1068, which appears to the eye like a mod-
erately fine-grained diorite. The thin section shows it to have under-
gone great alteration. The greater part of the field is made up of
elongated unterminated fibrous crystals, lying at all angles and frayed
out at the ends. These are of a pale green color and scarcely pleo-
chroic. The polarization colors are very brilliant, like those of tremo-
lite. In cross section two sets of cleavage lines, with an apparent
angle of 120-130° appear, while the longitudinal cleavage lines are
frequently wavy. The twins are numerous and in the plane i-i, and
the extinction angle c : c = nearly exactly 15°. This combination of
characters is hard to understand. The absence of pleochroism and
brilliant polarization indicate a monoclinic augite, but the extinction
angle, cleavage, and habit are like hornblende. This is, therefore, a
decomposing hornblende like uralite in general appearance and like
actinolite in characters. The iron has nearly disappeared from the
whole rock, a few scales of hematite being found in the hornblende.

OF DENISON UNIVERSITY.

131

The remaining ingredients of the diorite, with the exception of the
rather small amount of quartz, are more completely altered. The
place of the plagioclase is taken by an opaque white amorphous sub-
stance and the interstices are filled with granular light material. A
few crystals of decayed augite are seen, which have large quantities
of iron in stales and grains. Here and there grains of calcite indicate
where some of the decomposition products have gone. There are ex-
posed a few interesting masses of ilmenite, in which the hexagonal
plates are matted obliquely, which show under the microscope the
characteristic bronzy reflection.

No. 1064 is essentially similar. It is a very tough, homogen-
eous, greenish-grey rock. The actinolite is in the condition described
above and the accessories are ilmenite, calcite, and apatite. It pre-
sents to the eye the appearance of a fine-grained diorite, altering to
serpentine. Irregular bands of a lighter colored rock occur in this
mass. Such a specimen is No. 1065, which is a confused mass of
finely granular material in which quartz, calcite and chlorite can be
identified. Strings or veins of calcite are abundant, and scattered
through the magma are many dark grains, the centres of which are
generally filled by a single crystal of secondary calcite.

No. 1066. This is the porphyritic phase before spoken of, which
also contains the larger pebbles. Here and there in the section are
large rounded grains of quartz, broken and intersected by the finely
granular magma. The latter is not essentially different from the basis
of 1065, but is crowded with rounded grains of oligoclase. Grains of
secondary calcite and veins of the same, also pyrite and perhaps titan-
ite are seen in the slide. It would appear that the magma is full of
minute scales of chlorite, (Plate X, Fig. 2.)

The only explanation suggested for the curious condition of the
rock here is that the metamorphism was excessive and resulted in a
thorough suffusion of the original slate with intrusive matter as well as
pasty portions of the adjacent sediments, reducing all to a somewhat
homogeneous character. The conglomeritic phases of the slate being
rendered pasty, the pebbles were at first unaffected and were in-
truded upon by the more fluid matter below. They were subjected to
more violent flowage by reason of the obstinate pebbles during which
the ingredients of the pebbles were partly set free and, although the
magma was in part melted, the larger crystals remained dispersed in

132

BULLETIN OF THE LABORATORIES

the magma in the corroded condition already described. The calcite
and chlorite date from later periods.

At this point are a number of trap dykes, but the extreme point
(Burnt Point?) is made up of granite, which continues to the mouth
of Riviere de la Vieille. Just southwest of the river are precipitous
cliffs, 600-800 feet high, made up of the highly metamorphic equivalent
of the schist. Here at places the granite appears beneath the slate,
which is unconformable and tortuous, without obvious stratification.
The granite rises only a few feet above the water’s edge in undulations
and seems to have thoroughly fused the superincumbent schist at con-
tact. A few miles further south, toward cape Choyye, the high bluffs
recede from the shore, leaving the point composed of Keweenaw con-
glomerate and sandstone, which laps out near the water’s edge at a
slight inclination.

No. 1074 is a specimen of the schist taken near the underlying
granite and is a greenish, irregularly fissile rock, completely checked
up by joints and so altered and veiny as to act as an aggregate with
much chlorite.

No. 1075, taken near cape Choyye, is an irregularly lamellated
mica schist. The section shows much brown mica and quartz, some
apatite, magnetite, pyrite, and scattered porphyritic more or less
quadrangular grains appearing like completely decomposed feldspar.
Although dip and strike, as taken, were dip 60°, strike S. 10° W., we
rather incline to believe that this is the same rock as that on the west
side of the bay, with a strike which might bring it hither.

Returning to Dog river, we proceeded westward for about six
miles to near Eagle river, a small trout brook near the western limit of
the bay. Here are precipitous cliffs nearly 800 feet high. The rock
here consists of much altered highly crystalline schists, varying from
green to brown (No. io49-io49a). The mica is largely altered to
chlorite in the green, while jt is reduced to a powder in the brown and
mixed with hematite. Both contain very large quantities of calcite, as
a product of alteration of mica no doubt. These rocks contain much
quartz. The strike is E.S.E., i. e. much more nearly east than far-
ther northeast, and the dip only about 45°. Here in many places di-
orite lies interbedded between the strata of schist. This diorite is
composed of the same twinned hornblende, mentioned at the east side
of the harbor, but although it is superficially identical it differs in re-
taining strong pleochroism. The extinction angle and general appear-

OB' DENISON UNIVERSITY.

133

ance of the section, otherwise is identical. Here, too, the adja-
cent schist has assimilated itself to it most remarkably in general ap-
pearance, though a glance at a section shows it to be of a quite distinct
character. It is really an aliered mica schist (!) consisting of quartz, ‘
chlorite, much calcite and iron salts. This fact that certain eruptives
have the power to assimilate the adjacent rocks so closely in external
appearance as to defy recognition, while not altering the real nature
of the rock, needs to be constantly borne in mind by field-geologists.
These rocks, classed as greenstone slates and. considered as eruptive
by previous writers, can with care be readily separated into interbed-
ded sedimentaries and eruptives. A succession of such dykes is
seen east of Eagle river. West of Eagle river, especially on the jut-
ting point referred to by McFarlane, the schist suffers the extreme of
metamorphism, being twisted and gnarled in every conceivable way,
at the same time seggregating various minerals in pockets and lenticu-
lar masses. Veins of granite perforate the schist and include it in ir-
regular masses. The effect of such intrusive action is here well seen.
The fragments of schist so inclosed are angular and though often fused
into the granite, never permit comparison with the Dog river conglom-
erate. A direct comparison of this sorf may bring out relations hard
to verbally explain. The contact samples show much epidote which
. forms zones at the contact, veins in the schist, or replaces the horn-
blende in the granite. At this point is this immense dyke No. 1056.

No. 1058 is schist at the contact and consists almost entirely of
epidote containing strings and fragments of the aphanitic margin of
1056. Westward the granite constantly encroaches on the schist,
which is here a typical mica schist of fine texture.

The diabases, as before stated, are exceedingly monotonous in
composition and structure. A considerable range of variation in the
relative size of the ingredients is the chief divergence. They never
carry an appreciable amount of olivine and the feldspars are either lab-
radorite or labradorite and oligoclase, the former with brilliant polari-
zation colors and distinct outlines.

No. 1056 may* be taken as a type of the whole series. This is
especially interesting as being the dyke northeast of Michipicoten
island, called, by McFarlane, doleryte and considered by him and by
Wadsworth after him, as one of the sources of the schist. This is

134

BULLETIN OF THE LABORATORIES

perhaps the largest dyke encountered, being over 75 feet wide. Its
contact can be traced with both granite and schist. The former is
more or less enclosed by branches from the dyke, while the latter is,
in the main, sharply distinct. Yet in places there is some ex-
cuse for the confusion of the two. The schist is very tortuous and
variable and in places is dark, closely granular and might casually be
mistaken for the diabase. The epidotic character of the schist as well
as the aphanitic marginal zone of the diabase prevent real obscurity,
however.

This diabase is rather coarsely granular and dark in color. The
microscopic structure is beautifully distinct. Very large elongate
prisms of brilliantly polarizing labradorite and fresh, pinkish-brown
augite, the latter perforated in all directions by the former, make up
the most of each field, though some of the augite is altered to viri-
dite and epidote (?). The magnetite, of which there is considerable,
is altered to hematite and limonite. Very little apatite is present.
(See Plate XII, Fig. 4. )

No. nil, from the dyke at the mouth of Dog river, is typical
of another phase of these dykes. While most of the feldspar gives
angles indicating labradorite, the paler crystals generally fall below 36°,
indicating, according to Pumpelly’s method, oligoclase. The augite
is in long twinned crystals, which are often bent or frayed out at the
ends. The margin is often greatly altered, (Plate XII, Fig. 8,) pro-
ducts of alteration being uralite in strongly pleochroic fibrous masses
suffused with brown, and large flakes of hematite. The numerous
large grains of magnetite or titanic magnetite altering to titanite, may
be regarded as autochtones. The augites show very fine interrupted
fibrous structures, || O, the angle c : c being about 39°.

No. 1004 is a finer-grained diabase, east of Dog river, contain-
ing much metallic oxide and numerous greenish grains, with aggregate
polarization and tendency to be surrounded by iron grains. A -very
few crystals of orthoclase, with zonary structure (Plate XI, Fig. 4, )
are also noticed.

No. 1019a is a peculiar modification, being a densely black di-
abase-porphyrite with ilmenite instead of magnetite. The magma can
be resolved by a high power to an irregularly granular mass, which is
filled with peculiar grouped rods of the titanic iron. (Plate XIII,

OF DENISON UNIVERSITY.

135

Fig. 6.) The porphyritic grains are of plagioclase with scattered aug-
ite. It is thought that much of the granular magma is augitic. The
ilmenite is altered in many places to titanic iron.

In discussing the Keweenaw rocks as exposed on Michipicoten
island, cape Choyye and cape Cargantua, we shall describe only
enough to give a clear idea of the relations of this series to the older
Lawrentian and Huronian, as found in this region. We may consider
these rocks under two heads; first, the eruptive igneous, including all
the diabases, amygdaloids, pseud-amygdaloids and perhaps the porphy-
ries ; second, the sedimentary and metamorphic. The former might
be considered the result of a single series of overflows closely related.
The cooling of these, taking place under different conditions, as in the
presence of water, superheated steam, under great pressure or other-
wise, must of necessity produce many different forms of the same
overflow. Only those whose structure is in some way characteristic,
are here described.

No. 1077 (Plate XIII, Fig. 3.) occurs on the south shore of
Michipicoten island, forming the most of the islands along the shore.
It is filled with vein matter, principally of quartz and agate and is
also somewhat amygdaloidal. The color is black, with almost a metal-
lic lustre. An uneven fracture and exceedingly tough. The specific
gravity is 2.76. Under the microscope the rock is seen to be com-
pletely crystalline. Oligoclase makes up a great portion of the sec-
tion, occurring in long, fine crystals, generally twinned. Rounded
grains of augite are scattered irregularly through the mass. Here and
there a crystal of orthoclase is present, but much altered. A very pe-
culiar kind of grains, evidently suffused with iron of a bright yellow
color, without polarization or pleochroism, filled with inclusions, prob-
ably of gas, with concentric lines running through them, is found.
There is a very large quantity of magnetite in the rock, not occurring
in regular form, but rather filling the interstices between the other min-
erals. According to Rosenbusch this is a typical diabase.

No. 1082 (Plate X, Fig. i., and Plate XI, Fig. 3.) is a diabase
porphyrite, black in color, with light colored crystals varying from one
sixteenth to three-sixteenths of an inch in length, scattered thickly
through it. The specific gravity is 2.7. The fracture is distinctly
conchoidal. In the aphanitic magma large twins of labradorite cut

136

BULLETIN OF THE LABORATORIES

the rock in all directions. The following measurements of the feli
spar crystals were made:

20°+23°=43° whole angle.

35°+3o°=65° -

25° + 23°=:48°

According to Pumpelly’s method this would make the feldspar
labradorite. The crystals are exceedingly regular in form, cutting
each other in many directions. Inclusions in the crystals are frequent,
presumably fragments of the magma. Colors of polarization gray,
yellow and blue. Minute crystals of feldspar, all of about the same
size, thickly dot the black magma. These are probably of the same kind
as the larger crystals.

The next ingredient which attracts attention is the augite. This
is not nearly as abundant as the feldspar and does not occur in as large
crystals. The form of the crystals is rarely regular, generally some-
what rounded. Inclusions of minute needles of apatite are frequent
in the augite, also a greenish alteration product, otherwise it is un-
altered.

No. 1083 (Plate XIII, Fig. 8.) is a weathered specimen of the
same rock. The specific gravity is 2.66, being much lighter than the
original rock. Here an excellent opportunity to study the effects of
w^eathering is afforded. The augite has entirely disappeared, not a
single crystal in the section possessing any of the augitic characteris-
tics. A greenish product, much colored by the iron of the magma,
probably represents the decomposed augite. The feldspar, while in
many cases still retaining its crystalline form, is in every case altered,
generally from the center. The figure shows one of the less altered
crystals beginning to decay in the center. The alteration product is of
a light green color, very irregular in form, but in a few cases the regular
form of the primitive crystal is retained. The aphanitic magma of the
unaltered rock has changed to a yellowish brown, with small crystals
of magnetite dotting it all over.

No. To82a (Plate XIII, Fig. 7.) is the next phase of the dia-
base. It is a somewhat porphyritic diabase of much lighter color than
any of the preceeding, being almost reddish-brown, and showing some-
what the effects of weathering. The specific gravity is less also than
any of the preceeding, being only 2.6. The fracture is somewhat
conchoidal though not as much so as No. 1082. Under the micro-

OF DENISON UNIVERSITY.

137

scope the effects of decomposition become very manifest. The large
crystals of triclinic feldspar have altered to a mineral resembling or-
thoclase, but very much clouded. The smaller crystals of feldspar
have likewise changed, though not as much as the larger ones. The
chief peculiarity of the rock is the alteration of the augite into chlor-
ite. These grains are, some of them, an eighth of an inch wide and
so can be tested for their solubility in sulphuric acid. These grains
are arranged in spherulitic masses, with radiating structure in polyhe-
dra. There is a large amount of hematite and magnetite present in
the section.

No. 1085 is banded sandstone, with alternate layers of brown
and gray color. The grains are exceedingly minute, situated in a high-
ly argillaceous magma. They are so small that they are very difficult
to make out, but some of them are evidently triclinic feldspar from
their form and angle of extinction.

No. 1088 (Plate XII, Fig 7.) is a very black rock, with none of its
ingredients macroscopically visible. It has a shelly fracture and is
quite brittle. Under the microscope it is seen to have a crystalline
base of minute needles of plagioclase, in many cases twinned, with
small grains of augite frequently surrounding them in sort of a pseudo-
amydaloidal arrangement. Dotting the section are regular crystals, prob-
ably magnetite. Here and there are found large crystals of plagio-
clase, with regular form and entirely unaltered. This rock is a typical
diabase aphanite. It is situated on the southwest corner of the island,
overlying a bed of conglomerate, which will be described later.

No. ,1091 (Plate XII, Fig. 4.) is a specimen taken from the zone in
contact with the conglomerate. It is dark in color, minutely crystal-
line and crossed in all directions by minute veins. Its specific gravity
is 2.79. Small crystals of plagioclase are very abundant, also iron
grains. The vein matter has aggregate polarization. Whatever augite
is present it is entirely broken up, but still retaining its bright colors
of polarization and angle of extinction. The amygdules here are
small, generally greenish in color, without polarization or pleochroism.
Alteration product much resembling olivine is present in large quanti-
ties. This rock is very similar to the one figured by Irving, on Plate
IX, in his “ Copper-bearing Rocks of Lake Superior.”

The amygdaloids on the northwest corner island have not yet
been carefully worked up by us. They are highly amygdaloidal con-
taining large masses of calcite. Plagioclase, together with large

138

BULLETIN OF THE LABORATORIES

grains of augite much broken up, always makes up a considerable per
cent, of the rocks. They also carry quite a large amount of suffused
iron.

On the southwest corner of the island, rising above the water’s
edge several feet, occurs a fine-grained conglomerate with small, sharp-
ly angular grains. Embedded in this are large boulders from one to
twelve inches in size, of several different kinds. The question of the
origin of these boulders becomes of the greatest value in establishing
the relations of the different series. One of the most numerous is a
granite, quite close-grained, light colored, containing somewhat altered
white mica, orthoclase much changed, but still retaining its form, and
quartz. There are no accessories present. These boulders have all
been rounded by the action of water.

No. 1087 (Plate XIII, Fig. 2.) is from a typical mica schist of
a light gray coloi, dotted all over by minute black crystals, giving it
somewhat of a salt and pepper color. Microscopically the rock is seen
to have a cloudy gray magma, in which are scattered very profusely
small fragments of quartz. Large scales of biotite mica, permeated
in all directions* by smaller scales of the same, make up the remaining
ingredients of the rock. Much of the mica is changed to chlorite.
Comparing this specimen with No. 1051, a mica schist from the high
cliffs, eight miles west from Dog river, on the main land, we find that
they are almost identical in appearance and composition. Their color
in the hand sample is the same as well as all of their macroscopic
characteristics. Under the microscope we find the same similarities.
The magma differs slightly, but it is very similar in both. The size
and relative amount of quartz grains in the two are the same. The
mica in No. 1051 is more altered and is not aggregated into such .pe-
culiar masses. Perhaps the most noticeable difference is the presence
of a few smill crystals of triclinic feldspar in No. 1051, but this can
be explained by the proximity of the eruptive No. 1050.

Another interesting example is a boulder of mica diorite which is
also common in the conglomerate. The plagioclase occurs as very
numerous small elongated crystals, permeating the section in all direc-
tions. These have been slightly altered, but can be readily
identified. The mica has for the most part disappeared, chlorite tak-
ing its place. This rock can also be readily referred to the igneous
form, No. 1050, which occurs at the same cliffs, interbedded with the
schists. As in the preceeding case the chief differences lie in the de-

OF DENISON UNIVERSITY.

139

gree to which they have decomposed, the ingredients being exactly the
same in the two specimens. Felsite porphyries are very numerous in
this conglomerate, occurring in well rounded boulders. The magma
is dark red in color, frequently showing fluidal structure. In many of
the specimens minute grains of quartz have almost entirely replaced
the matrix. Quartz crystals of any considerable size are rare in many
of the specimens. Orthoclase crystals, with regular form, but much
altered, are present in large quantities. These porphyries resemble
closely No. 1019, already described, which occurs at Dog river, on the
mainland. The matrix in which these boulders are imbedded varies
greatly, according as it approaches the diabase No. 1088, which complete-
ly covers it. Small crystals of quartz, orthoclase and plagioclase, which
are remarkably free from alteration, calcite, together with a few small
fragments of much altered diabase, and several other ingredients
which could not be identified, make up the mass of the rock.

The conglomerate which occurs at cape Choyye is made up entirely
of loosely compacted grains, quartz and feldspar being the principal ones.
There seems to have been no such action of heated matter at this
point, as on the island where capped by diabase, nor do boulders of
such size here occur. As seen from the above, the observations of Ir-
ving, in regard to these conglomerates, do not seem here to apply.
For as we have said, there are boulders of three distinct kinds in the
conglomerate on Michipicoten island, which have no parallel in the
rocks occurring there, but can be easily referred to the older Lawren-
tion and Huronian.

The quartz porphyries which occur about one mile south-east from
the mines toward the center of the island appear to be closely related
to the conglomerate described above and have all the appearances of
being simply this congloinerate fused by the overflow of the diabase.
Our data are too meager to make this anything more than a sugges-
tion. A careful study of the ground and patient tracing of contact
zones are necessary before anything can be positively affirmed of
these. The weathering to which these rocks have been subjected, ren-
ders the problem all the more difficult, as in many places soil several
feet thick has been formed.

No. 1 099 ( Plate XIII, Fig. i .) is a typical illustration of these por-

phyries. It is of a very dark red color. Crystals of quartz and or-
thoclase, averaging about a sixteenth of an inch in size, are regularly
distributed throughout the specimen. The. magma is light red in color

140

BULLETIN OF THE LABORATORIES

in the section and completely felsite. The figure shows one of the
quartz crystals cut exactly transversely. The only other conspicuous
ingredient is orthoclase. This occurs in crystalline form, frequently
in baveno twins, but never unaltered.

No. 1099b is found a short distance from the above. It is of
lighter color than No. 1099a, and has a more distinctly conchoidal frac-
ture. Large crystals of quartz, about an eighth of inch wide, and de-
composing feldspar crystals of light reddish color, one-fourth of an
inch in diameter are readily distinguished. The quartz crystals are
regularly filled with inclusions. Besides the larger crystals of quartz,
there are present smaller grains in large quantities, these latter of
about the same relative size. There is no free iron oxide present in
either specimen. Besides these two typical porphyries, there are two-
other kinds, which on account of their weathering can not be satisfac-
torily studied. One coarsely granular variety is light red, with whitish
grains, (orthoclase .^), scattered throughout it. These grains can not
be identified because of their decomposition. This rock has the char-
acteristics of a porphyry, but greatly resembles, superficially, the con-
glomerate. The other, occurring but a short distance from No. 1009b,
is apparently fragmental, but the fragments are angular and irregularly
aggregated, and in section appear like the felsitic magma of the adja-
cent porphyry. No critical examination even of our inadequate
material is now possible.

In conclusion, then, the north shore of lake Superior presents
three distinct groups of rocks with their respective intrusives, which
may be designated as granitic, schistose and conglomeritic. The gran-
ites are coarsely granular and contain small amounts of hornblende or
mica and are occasionally augitic. The quartz is in large amount,
while plagioclase is often present. These granites are found underly-
ing the schists in such a way as to suggest that they have been intrud-
ed beneath them, though of course the material must have previously
existed. That the material was granitic is indicated by the fact that
precisely similar granites associated with felsites constitute the pebbles
of the basement conglomerates in the schists. The origin of this old-
er granite is unknown, but it would seem that it occurred in the same
way as the existing exposures beneath sedimentary or other masses
which have been used in the formation of the schists.

The eruptives found. perforating the granite are all diabases. It
is not denied that there may be felsite dykes, but none were observed.

OF DENISON UNIVERSITY.

141

The schists have been fully described. There are constantly metamor-
phosed at contact with the granite and are perforated by dykes of di-
orite and felsite in the stratification, the former being derived from the
fused lower part of the schists, the latter from the upper part of the
granite more or less modified by contact with the schist. The schists
and schist-conglomerate especially have in several places been altered
to porphyry and felsite-porphyry by contact with the eruptives with or
without obliteration of the schistose structure.

The third group consists of basement conglomerates consisting of
fragments of all the varieties of rock included above, which it is possi-
ble to trace to their immediate source in the high cliffs adjacent. Pe-
riodic overflows of igneous matter have left vast sheets of diabase,
diabase-porphyrite, and diabase-aphanite, varying into so-called ash-
bed diabase, distributed irregularly with amygdaloids and pseud-amyg-
daloids in great variety. These flows were often apparently sub-aquatic
and the strong interaction between the sedimentary and eruptive in
presence of superheated steam or slowly percolating water has caused
the concentration of metals along contact zones of the amygdaloids.
The great quantity and area of the overflows caused extensive fusion
in the conglomerates in places, possibly producing a part of the quartz-
porpyry and porphyritic conglomerates. The large quantities of cal-
cite in this whole series is taken as proof of its essentially metamor-
phic character (in the sense of local derivation from existing materials.)
There is no evidence in this region that there were extensive eruptions
of acid rocks to furnish the materials for the clastic members, all the
conglomerates being easily derived from the adjacent cliffs of granites
and schists. No gabbro or allied rock which could be identified as an
eruptive of Keweenaw age was seen. It is evident that a very con-
siderable interval must have elapsed since the disturbance of the schist
prior to the formation of the Keweenaw conglomerates lapping upon
them. Erosion of enormous extent must have gone on and the mate-
rials may have been transported far into what is now the bed of lake
Superior. If this be the case, of course the base of the Keweenaw is
not exposed at all, but is situated far southward and the marginal part
very likely displays very different characters from that nearer the axis
of depression.

We desire, finally, to acknowledge the kindness of the Hon. Rob-
ert Bell, the distinguished geologist of the Canadian Geological Sur-
vey, for literary aids, and to disclaim any hope to do more in this pa-

142

BULLETIN OF THE LABORATORIES

per than point out a few simple facts and certain more or less pre-
sumptive inferences bearing on that most interesting problem, fur-
nished by the Azoic system.

PLATE X.

Fig. I. Diabase j)orphyrite, No. 1882.]

Fig. 2. Felsite porphyry, No. 1066.

PLATE XL

Fig. I. (No. 1001.) Section of chloritic schist just east of Dog river. A
closely granular magma of quartz, feldspar and calcite, with large irregular crys-
tals of calcite (<r), mica flakes {m)., quartz grains (0, and scattered magnetite and
hematite.

Fig. 2. (No. looS.) Section lenticular felsite-porphyry, occurring in the
schist, showing fluidal arrangement of the magma, L. orthoclase and oligoclase.
0 quartz.

Azg. 3. Diabase porphyrite (No. 1082.) from southwest coast Michipicoten
island. (See Plate X, Fig. i.) y. labradorite, a. augite, x. apatite, 3a. portion of
magma highly magnified, 3b. vesicles from same, 3c. crystals and twins of plagi-
oclase from same, 3d. isotropous section of apatite from same.

Fig. 4. From a dyke (No. 1004.) one half mile northeast of Dog river, o.
orthoclase,/. plagioclase, a. augite, x. peculiar green amorphous grain. Much
magnetite.

Fig. 5. Diagram of felsite veins in schist, east of Dog river, (Nos. 1008 and
1009.)

Fig. 6. Diagram of contact between Nos. 1019 and 1019a. No. 1019, por-
phyryritic phase of schist, 1019a. fine-grained diabase porphyrite.

Fi£. 7. Section through strata at west end of Michipicoten island. C. coarse
basement conglomerate, F. banded fine-grained sandstone in C. X. Contact zone
of conglomerate, (cupriferous) 10 feet. T. Amygdaloidal trap, 40 feet. A. vesic-
ular amygdaloid 33 feet.

Fig. 8. Hypothetical section through Michipicoten island, along line A-B.,
figure 9.

Fig. 9. Outline map of Michipicoten island, (not accurate) with position
of numbers in our series and supposed lines of strike.

PLATE XII.

Fig. I. (No. loiib.) Seep. 126.

Fig. 2. (No. loiia.) Seep. 126.

Fi^. 3. (No loiic.) Seep. 126.

OF DENISON UNIVERSITY.

143

Fig. 4. (No. 1056.) Section of diabase from large dyke cutting the point next
west of Eagle river.

5- (No. 1018.) Chlorite scales.

Fig. 5. B. (No. 1018.) pseudomorph of chlorite after mica.

Fig. 6. Baveno twin of orthoclase from-'granite No. 1059.

Fig. 7. (No. 1088.) Diabase-aphanite capping the conglomerate near west
end of Michipicoten island. The conglomerate extends 30 feet above the water’s
edge and is covered by the aphanitic phase of 1088, which becomes more porphy-
ritic above. The conglomerate is itself altered to a porphyry near contact.

I^ig. 8. Twin of augite from dyke (No. iiii.) at west side of Dog river at
its mouth, a. augite,/". feldspar, m. magnetite, u. uralite.

Fiq. 9. Conglomerate near Dog river, (No. 1023.) pebbles being 12 inches
in diameter. From a photograph.

Fig. 10. Diagram of supposed geological structure of lake Superior, partly
after Irving. A section through Michipicoten island and and Keweenan point.

PLATE XIII.

Fig. I. Section of the porphyry No. 1099a, with a slightly corroded isotrop-
ous transverse section of quartz.

hig. 2. No. loSya. Altered mica schist as a boulder in 1096.

Fig. 3. Pseud-amygdule from 1077, with concentric ferruginous bands.

Fig. 4. Pseud-amygdule in 1091.

Fi^. 5. Augite twin in granite No. 1107, near contact. /. feldspar, q. quartz-

Fig. 6. Highly magnified portion of No. 1019a. Diabase porphyrite at
Dog river, with grouped crystals of titanic iron.

Fig. 7. Section of No, 1082a. with concentric pseud-amygdules of chlorite
in stellate polyhedral aggregates, f. plagioclase. The black is magnetic.

Fig. 8. Altering crystal of plagioclase in 1083.

Fig. 9. A. map of region about Michipicoten} river, north shore of lake Su-
perio.r. B. Section along A B in above map.

I

Sketch of the Geological History of Licking Co. — No. 2.

Additional Fossils from Coal Measures at Flint Ridge.

(Plate XIV.)

Opportunity has been afforded to examine a few additional speci-
mens from the shale above the cannel coal at Flint Ridge, among
which are the following :

1. Lingula scotica., Day. (var.^) (Plate XIV, Fig. 15.)

Our only specimen is a fragment, agreeing pretty closely with the
form from the Waverly identified with this species by Meek (Pal. O.
Vol. II, p. 276. ) If Meek’s figure is accurate the Waverly species
has quite a different outline from the Scottish, as figured by Davidson,
(Carb. Brach. vol. IV, part III, plate XVIII, Fig. 5. ) The latter
also says, “ Beak extremely attenuated and acutely pointed at its ter-
mination.” L. scotica, var. nebrascensis., Meek, though much smaller,
has more distant striae. It is probable, judging from the fragment,
that our specimen had nearly the form of the European.

2. Lingula umbonata.^ Cox. (?) (Plate XIV, Fig. 2.)

The species resembles some varieties of Z. squamiformis., Phillips,
while Z. 7nelie H., as figured from the Waverly by Meek, resembles
closely some forms of Z. mytiloides. Sow. Specimens of L. melie in
our collection, however, show the very prominent mesial ridge char-
acteristic for that species. L. tighti, from the cannel coal a few feet
below the present horizon, unless all specimens examined were dis-
torted, differs very greatly in outline, (see Plate IV, Fig. 5.) In size
specimens under consideration agree exactly with the Indiana speci-
mens of L. umbonata, but are proportionally wider, especially above
the middle,

3. Discina co^ivexa., Shumard. (Plate III, Fig. 9. )

OF DENISON UNIVERSITY.

145

4. Discina nitida^ Sow. (Plate II, Figs. 8-9.)

(Discina meekiana, Whitfield. )

This species, if not identical with the European, is a very close
vicarious form and ought probably to be ranked as a geographical va-
riety. Some of our specimens show the radiating markings figured
by Davidson (1. c. supl. .Pl. XXX), and differ chiefly in the somewhat
more central position of the beak.

5. Edmondia (?) rcflexa^ Meek, (Plate XIV, Fig. 21.)

Only the exterior of the valves has been seen.

6. Pleurophorus vnmaturus ^ sp? n. (Plate XIV, Fig. 17.)

There would seem to be constant differences between the small

compact form referred to on page 35 and P. subcostaius, yi. and W.,
which proves to be very abundant and typical. A considerable series
of the latter has been obtained with constant characters.

While far from sure that the smaller form is not the young, it may
be best to distinguish it. The lower anterior margin is more abruptly
curved and the lower margin convex. The width is over one-half the
length, while in P. subcostatus it much less. The radiating striae also
cover a larger part of the shell, which is more convex. -

7. Placunopsis carhonaria^ M. and W., (Plate XIV, Fig. 27.)

A- specimen from the locality ofMeek’s P. recticardinalis is, like
the one figured in the O. Pal., a cast of the interior, but has the beak
nearer the posterior rounded ear. The markings seem to be char-
acteristic and not accidental. Meek’s conjecture of the identity of
these species seems correct.

8. Cf. Pseudomonotiis radialis. Meek, Pal. Neb., Plate IX,
Fig. 3. (Plate XIV, Fig. 26.)

A single left valve resembles that figured by Meek, but has
coarser distant radiating lines with finer striae implanted between.
The posterior wing is imperfect at the very top. The generic refer-
ence is doubtful.

9. Schizodus curfus, M. and W. (Plate XIV, Fig. 20.)

This small species is represented by both valves in connection,
which agree quite as well with S. rossicus, however, as the species to
which they are referred.

10. Schlzodus subcircularts , Her. (Plate XIV, Fig. 18, ) a cast.

11. Avicula {Gervillia) ohioense, Her. (Plate XIV, Fig. 22.)

146

BULLETIN OF THE LABORATORIES

A specimen apparently identical with those on which the species
was founded is somewhat better preserved than those previously fig-
ured. The outline is nearly exactly that of Pterinea pintoensis, Wal-
cott, but it is not covered by strong ridges as in that form and possess-
es the external ligamental groove (?) It is very likely that our species
belongs to Leptodesma or at least in that section of the Aviculidae.

12. Allorisma cosfata, M. and W. (Plate XIV, Fig. 25.)

We have thought best to illustrate the largest specimen of this
species yet obtained, which it is hard to identify with the specimen
figured in O. Pal. vol. II, Fig. 6, plate XIX.

13. Myalina sp. Plate XIV, Figs, i, la.)

This fine species was secured too late for study, but is perhaps

new.

14. Myalina ? sp. ? (Plate XIV, Fig. 24.)

This species likewise is not identified, it resembles a Modiolopsis
more than any carboniferous genus with which it has been compared.

15. Nautilus forbesianus, McChesney, (Plate XIV, Fig. 13.)

The fragment drawn is from Mr. Foerste’s collection and is suffi-
cient to indicate the species. A very much larger species is also indi-
cated by mere fragments.

16. Goniatites (?) cf. G. iowensis^ M. and W. (Plate VIII,

Fig. II.)

The cast does not even show the presence of septa and the "gen-
eric reference rests only upon a general resemblance in form to the
very flat species quoted.

17. Dentalium sp2 (Plate XIV, Fig. 12.)

This closely resembles D. canna, White, but has more oblique
striations and aperture. Apically the longitudinal striations are strong,
but toward the aperture they disappear and the concentric stri^ ap-
pear. The section seems to be naturally oval, though the specimens
are all somewat flattened.

17, Conularia neivberryi, Meek (?) (Plate XIV, Fig. 14.)

A fragment of a large Conularia indicates a fine large species with
much finer striae than C. missouriensis, as figured in Pal. 111. vol. 5,
but agreeing well with the figure given by Walcott, under that name,
but which should probably be identified with C. newberryi. The
specimen is interesting because of the rarity — almost absence — of
shells of this genus from the American coal-measure rocks. The cos.

OF DENISON UNIVERSITY.

147

tae in this species are acutely prominent and are separated by wider
depressions (about 24 to the inch) and are apparently not striate or
crenulated.

18. Euomphalus subquadratiis^ (Plate XIV, Fig. 9.)

Quite common.'

19. Loxone?na sp? (Plate XIV, Fig. 8.)

This shell is an almost exact miniature of that figured Plate III,
Fig. 2. Although both have the same number of volutions, yet that
one is three and one half times as large. In the present species the
plications are more numerous and scarcely oblique. There are ten
volutions in a shell seventeen millimeters high. About nine or ten
plications are visible on one side of the lowest volution. The spire is
moderately slender. Diameter of lower volution about live and one-
half millimeters. Z. rugosum, M. and W., has larger volutions. Z.
strigillatum, Dekon., is similar, but is more slender and has more nu-
merous plicae. Should this species prove undescribed it may be called
L. plebium and the large form figured on Plate III, Fig. 2. L. plenum.

20. Macrocheilus {Soleniscus)fusiformis, Hall? (Plate XIV, Fig. 7.)
Although much tempted to identify this with S. klipparti, Meek, it
would then be necessary to modify the description greatly, for Meek
says, “ spire, with its lateral slopes, concave above and convex below;
volutions six to nine, the upper five or six being very compactly coiled,
and forming comparatively but a small part of the entire shell,” nei-
ther of which statements apply to our form. Fig. 4, of Plate XIV,
seems to be S. medialis^ M. and W. and Figs. 5 and 6 most nearly re-
semble S. planus, White.

148

BULLETIN OF THE LABORATORIES

PLATE XIV.

Fig. I. Myalina sp?

Fig. 2. Lmgula umbonata.^ Cox ; two valves in connection.
Fig. 3. Straparollus ?

Fig. 4. Solenisais medialis^ M. and W.

Fig. 5. So kniscus planus, White?

Fig. 6. Probably the same species as Fig. 5.

Fig. 7. Soleniscus fusiformis, Hall.

Fig. 8, Loxonema plebium, sp. n.

Fig. 9. Euomphalus subquadrahis. ■

Fig. 10. Orthonema? sp.

Fig. II. Goniatites iowensis, M. and W.

Fig. 12. Dent a Hum sp.

Fig. 13. Nautilus forbesianus, McChesney.

Fig. 14. Conularia newberryi, yiedkl
Fig. i5» Lingula scotica, Davidson.

Fig. 16. Unidentified.

Fig. 17. Pleurophorus i/nmaturus, s^,x\.

Fig. 18. Schizodus sub-circularis, Her.

Fig. 19. Schizodus, cast of a very convex species.

Fig'.- 20. Schizodus curtus, M. and W.

Fig. 21. Edmondia {?) rejlexa. Meek.

Fig. 22. Gervillia ohioense, Herrick.

Fig. 23. Tooth of fish ? , •

Fig. 24. Myalina (Modiolopsis ?)

Fig. 25, Allorisina costa ta, M. and W.

Fig. 26. Pseudomonotus sp ?

Fig. 27. Placunopsis carbonaria. M. and W.

THE CLINTON GROUP OF OHIO.— Part HI.

BY -A. F. FOERSTE.

BRYOZOA.

The Clinton Group of Ohio is remarkable for the fine preservation
of a series of FtilodictyonidcE of rather large size, and for the meagre
representation of all other families of the bryozoa. In 1875, Hall and
Whitfield described five species from the Soldiers’ Home Quarries, in
Ohio Paleontology, Vol. H. In 1878, U. P. James described two spe-
cies, in The Paleontologist, No. I, in 1879, three more in No. HI, of
the same periodical; these specimens were collected in Clinton county,
at an exposure three miles north of Wilmington, along Todd’s Fork.
In 1882, Hall described seven species, in Indiana Geol. Surv. 12th
Ann. Report; the basis of these descriptions was some drawings and
antiquated notes left by Mr. Van Cleve; the specimens were collected
at Dayton, probably in the region of the Soldiers’ Home Quarries.
The drawings of Mr. Van Cleve were the work of an artist, rather than
the careful copy by a naturalist of the specimens at hand. His bryo-
zoa, however, are readily enough determined. These publications
have given rise to quite a little synonomy considering the small num-
ber of species involved ; our large collections, however, from the
original localities will readily unravel any confusion that may exist. '

150 BULLETIN OF THE LABORATORIES

In the following pages the sj^stem of classification used is that of
Mr. E. O. Ulrich. This necessitates the change of many generic refer-
ences. Unfortunate as tl\is may be, when a name has become familiar
and has been universally adopted, it is necessitated by very clear and
universally recognized facts. The description of bryozoa has until re-
cently consisted chiefly of the characterization of the external features
of the specimen. Specimens of very different structure have often
been associated together in incongruous genera, on the evidence of
external features alone. In consequence also of that system of classi-
fication, generic values were ill understood, and types of genera
could not prove a key to the situation. The new method has sought to
furnish a scientific basis to this artificial classification, and an unflinch-
ing application of the universally recognized rules applying to the type
species of genera, has made the avoidance of such changes simply im-
possible. In view of these facts it is rather amusing to notice the feel-
ing among many of our American paleontologists that Mr. E. O. Ul-
rich is unsettling the foundations of the classification of bryozoa, when,
in fact, he and the prominent European students of bryozoa, are mere-
ly doing all they can to give us a firm basis. Mr. Ulrich has assisted
me so much in the investigation of bryozoa, by advice, criticisms, the
presentation of specimens and the investigation of my own, that I can
only express general indebtedness.

FENESTELLIDyE, King.

Zoaria reticulated by the anastomosing of stems, or fenestrated by
the coalescence of the short non-poriferous branches of adjacent stems,
the dissepiments. Poriferous on one side only ; the cells sub-tubular,
their mouths rounded.

Genus PHYLLOPORINA, Ulrich.

Zoaria flabellate, perhaps infundibuliform when entire, consisting
of anastomosing stems which form elongated, irregular meshes. Sec-
tions made transversely at some distance from the poriferous side show
only one kind of cells. Sections passing just beneath the surface
seem to pass through short interstitial cells, which are closed at the sur-
face. Species of this genus have usually been referred to Retepora^
Lamarck.

OF DENISON UNIVERSITY.

151

I. Phylloporina angulata, Hall.

{Plate XV, Fig. i ; Plate XVII, Fig. i.)

^ Retepora angulata ?, Hall and Whitfield (J?. Daytonensis proposed), 1875;

Ohio Pal. Vol. II, p. III.

Retepora angulata, Hall, 1882 ; 12th Ann. Geol. Rep. Indiana, p. 269.

Frond found in flabellate fragments, originally perhaps infundi-
buliform, reticulated by the anastomosing of the dichotomously divid-
ing stems, forming elongated fenestrules, which are of small size to-
wards the base of the frond, increasing in size above ; fenestrules from
the same portion of the frond of about the same size. Poriferous side
strongly convex, the non-poriferous side much less convex, and finely
striated longitudinally. The cells are separated only by the cell-walls
below, above they become constricted, opening upon the surface as
small, rounded apertures which are more or less removed from each
other, the intermediate portion seems often to be occupied by short in-
terstitial cells not visible at the surface. The cells are arranged in
four rows along the stems, the lateral rows opening directly upon the
fenestrules. Cross-sections show that the two lower rows arise along
the middle of the non-poriferous side and extend along the
same to the lateral apertures, the two middle rows arise very near the
origin of the lower rows, and open along the upper side of the stem.
Partition walls extend longitudinally between the cells ; in division,
the middle wall usually divides dichotomously and terminates at the
origin of the new branches, the two lateral walls form the central par-
tition wall of the new branches ; the lateral partition walls in the branch-
es seem to arise from the middle wall by lateral division. During an-
astomosis, one or the other of the stems seems to prevail and to give di-
rection to the cells of the new structure.

The ordinary variety of this species is of common occurrence,
and is characterized by rather stout stems anastomosing at comparative-
ly short intervals ; another variety with equally stout stems has much
more elongated fenestrules, 3 mm. or even more in length. The va-
riety for which the name R. Daytonensis was suggested has very nar-
row branches, about .25 mm. broad, forming fenestrules 2.5 mm. long.
This form is said to differ from the typical forms of Ph. angulata in
‘^not possessing the angular ridges between the pores, and in having
the borders of the pores elevated, forming the spur-like projections
which that species does not show.” In our specimens a nodose ridge

BULLETIN OF THE LABORATORIES

152

along the middle of the stems is very evident. A similar ridge seems
to extend along either side^ thickening the inner side of the lateral
TOWS of cell apertures. Since the alternate arrangement of cells is
not regular, the lower cells are often brought beneath the upper ones,
•and then give them the appearance of having “a spur-like lip” on
the lower side ; and again, when these specimens are not free from the
surrounding rock they may appear to have only two or three rows of
cells, and this same arrangement may give the false impression that
the cells of the lateral ranges have the outer lip extended and ele-
vated, bringing that side of the margin to a level with the inner mar-
gin.” About 7 cells are found in a distance of 2 mm.

Locality and position. Soldiers’ Home Quarries, Brown’s Quar-
ry, Fair Haven, Todd’s Fork, Clinton Group.

Genus HEMITRYPA, Phillips.

Zoaria infundibuliform, poriferous on the inside, with branches
nearly straight and connected at regular intervals by non-poriferous
dissepiments. Cells in two rows, separated by a thin median keel. The
keel is supplied with elongated tubercles above; from the columns
thus formed, slender lateral processes extend on either side to the cen-
tre of the space between the keels, where they are united into a deli-
cate network, forming two series of openings between each pair of
keels, the openings corresponding in number to the cells beneath.

IT Hemitrypa Ulrichi, sp. n.

{Plate XV, Fig. 2 ; Plate XVH, Fig. 2. )

Frond infundibuliform below, broad and horizontally expanded
above, the edges in large specimens decumbent. Diameter of the
largest specimen seen, 40 mm ; but fragments indicate that the speci-
mens may attain a width of even 60 mm.

The poriferous side rarely shown and even then the pores are usu-
ally obscured by a peculiar network which is stretched above them.
Branches with a median keel along the summit of which, situated at
regular intervals, are a number of prominences from which slender
processes extend horizontally to the centre of the space between the
keels. The processes of adjacent branches unite along the middle of
the space between the keels, forming a net, the circular openings of

OF DENISON UNIVERSITY.

153

which usually alternate between the keels of adjacent branches, but
are opposed when situated on opposite sides of the same keel. The
mesh-work thus formed is very beautiful. The openings correspond in
number and situation to the cells beneath. Microscopical sections
show the cells to be angular below, becoming rounded and circular
above, and opening laterally upon the sides of the branches. About,
three cells occupy the length of a fenestrule.

The non-poriferous side forms the upper or inner face of the frond,
and is the face usually presented. The branches are of medium size,
from 5 to 6, usually 5.5 in the width of 2 mm, remotely bifurcated,
connected by dissepiments. Dissepiments strong, two-thirds as wide
as the branches, in some cases wider, in others narrower, about 4 to
4.5 in the length of 2 mm. The branches appear smooth in perfect
specimens, slightly striated longitudinally in worn specimens. The
fenestrules are oblong in form, the corners rounded.

Named in honor of Mr. E. O. Ulrich, to whose kind assistance I
am in many ways indebted.

The keels of Hemitrypa dubia^ Hall, are connected by continuous
transverse bars ; this species is therefore a member of the genus Uni-
trypa, Hall, and our Clinton species is undoubtedly the oldest species
of Hemitrypa known.

Locality and position. Brown’s Quarry, Clinton Group, common.

PTILODICTYONID^, Zittel.

Zoaria consisting of compressed branching or simple leaf-like ex-
pansions, composed of two layers of cells, grown together, back to
back, by the adhering of their epithecal laminae. Interstitial cells,
when present, never in the form of vesicular tissue.

Genus CLATHROPORA, Hall.

Zoaria consisting of dichotomously dividing branches which anas-
tomose at fairly regular intervals, forming a flabellate fenestrated frond.
Interstitial cells entirely wanting.

154

BULLETIN OF THE LABORATORIES

III. Clathropora frondosa, Hall.

{Plate XV, Fig. 3; Plate XVII, Fig. 3.)

Clathropora frondosa, Hall, 18S2, iith Indiana Geol. Report.

Fronds flabellate, composed of branches which divide dichoto-
mously at short intervals, forming short curves, which come in contact
again, coalesce, and divide as before ; by this means a fenestrated
frond is produced, which would alternately consist of a series of short
free branches or a series of rings along the growing edge, if the growth
were regular. In that case the fenestrules would be also arranged in
a concentric series of rows, the rows containing one more fenestrule
after each reunion of the branches. As a matter of fact, bifurcation
does not proceed in so regular a manner, but still enough regularity
exists to place the fenestrules in something like lines or curves, which
are often very striking. The fronds expand rapidly above, the sides
forming broad, outward curves, the anterior edge being broadly round-
ed. The fenestrules are comparatively small, oval or even circular in
shape. The cells are quadrangular, rhomboidal or hexagonal in form,
never typically elongated. From 7 to 8 cells occupy a length of 2
mm. The number of cell-rows on the branches varies from 8 to 17.
The fenestrules are also variable in size, an average size being 2 mm,
varying to 3 mm. The fronds frequently become very large, attaining
a length and breadth of 200 mm. The base of the fronds in the two
:specimens which alone preserved this portion was observed to be
broadly rounded just beneath the first fenestrule, indicating that the
frond was attached by the stipe to an articulating base ; the latter has
not been identified in our collections.

Locality and position. Soldiers’ Home Quarries, Centreville, Clin-
ton Group.

IV. Clathropora Clinton ensis. Hall and Whitfield.

■{Plate XV, Fig. 4; Plate XVII, Fig. 4.)

Clathropora Clintonensis, Hall and Whitfield, 1875 ; Ohio, Pal. Vol. H.

Fronds very similar to the last, the fenestrules varying from 2 to
5 mm. in length ; typically they are of larger size than those of C.
frondosa^ and are more elongated and irregular in form, varying from oval
to ovate, sub-rhomboidal,. or even irregular in outline, the upper part

OF DENISON UNIVERSITY.

155

of the fenestrules being frequently more or less acute. The compara-
tive width of branches and enclosed fenestrules has no specific
value whatever, the character of real importance being the form of the
cells, which are elongated oval in form, the length equalling about
twice the width. The cell apertures are arranged between quite prom-
inent longitudinal ridges. From 6 to 7 cells occupy a length of 2 mm.
The base of the only frond preserving this feature seems to pass with-
out interruption into a stipe about 4 mm. broad and 18 mm. long, to-
wards its origin the base becomes rapidly attenuated and may have ar-
ticulated with some expanded, rooting structure. Until more speci-
mens of this kind are discovered, this feature can have no value.

Locality and position. Soldiers’ Home Quarries, very common at
Fair Haven, Clinton Group.

Genus PTILODICTYA, Lonsdale.

Zoaria wedge-shaped below, above expanding into an undivided
leaf-like expansion. The cells are arranged in diagonal cross-rows or
have a plumose arrangement, diverging in rows from central longitudi-
nal series of cells, which usually are of smaller size. Interstitial cells
wanting. A non-poriferous margin occurs in most species, this if
present in the following species must be very narrow.

V. Ptilodictya expansa. Hall and Whitfield.

{Plate XV, Fig. 5; Plate XVI I, Fig. 5.)

Phaenopora (Ptilodictya) expansa, Hall and Whitfield, 1875; Ohio, Pal.
Vol. II. Plate V. fig. I, is a specimen of Phcenopora platyphylla.,
James, 1879.

Ptilodictya expansa, Hall, 1883 ; 12th Indiana Geol. Rep. The original de-
scription is here republished, but Plate 12, figs. 2 and 3 are correctly identified.

Frond arising from a wedge-shaped base, gradually enlarging,
forming lanceolate expan.sions, or elongated oblong forms with paral-
lel sides. Epithecal membrane marked by lunate lines of growth
along the mesial series of cells, their convex sides directed forward ;
along the sides of broad specimens there are often longitudinal wrin-
kles, perhaps indicating that these specimens were derived from the
narrower forms by lateral growth. Along the middle of the frond ex-
tend from 4 to 7 longitudinal series of cells, which are always con-

BULLETIN OF THE LABORATORIES

156'

spicuously narrower than the lateral rows, in sections made just above
the epithecal membranes. The central cells often show a tendency
towards a secondary horizontal arrangement, the lateral cells however
have also a well-defined secondary diagonal arrangement, diverg-
ing from the central rows of cells at an angle of about 15° above
a line drawn horizontally across the surface of the frond. The small-
er size of the mesial cells, and the diverging cells on either side give
the frond a leaf-like or rather a plumose arrangement which is very
characteristic.

Cells angular below, quadrangular or rhomboidal ; rounded at
their apertures, oval or almost circular ; arranged between longitudi-
nal raised lines. Fragments of variable size have been found, often
70 mm. long, without any evidence either of base or apex. Full grown
specimens were probably 15 to 20 mm. in length. The broadest speci-
men with perfectly parallel sides seen was 16 mm. broad ; the broad-
est specimen of those of more irregular form measured 25 mm. from
the mesial series of cells to the lateral edge, the entire width therefore
was probably 50 mm. Mesial cells usually number 14 to 16 in a
length of 4 mm; lateral cells, 10 to 14 in the same length. From 17
to 19 lateral cells occur in a width of 4 mm. The mesial cells are
narrower than the lateral cells, but the degree of narrowness is vari-
able.

There is not the least doubt of the identity of the first figure pub-
lished with Phcenopora platyphylla, James ^ a form related to Ph. constel-
lafa, Hall^ with which species, indeed, the authors compared our Ohio
specimens. But the identification made by Hall, among the figures
prepared by Van Cleve, evidently shows that the authors had an elon-
gated species in mind which they considered typical.

Again most of the distinct features mentioned in the original de-
scription are those of Ptilodictya expansa. These are : “ fronds form-
ing . . . elongate stipes, . . .. the lateral edges are

generally parallel, . . . thin longitudinal partitions .

slightly raised above the upper and lower walls of the cells,
cells ... in horizontal, or nearly horizontal, rows, diverging
from the central partition at an angle of about fifteen degrees above a
horizontal.” The reference to maculae ” is of course a description
of features belonging to the specimen of Phcenopora plaiypJiylla figured.
There is some doubt as to the meaning of the words ‘‘central parti-
tion” which I have italicised. If these refer to the narrow mesial cell

OF DENISON UNIVERSITY.

157

rows, the description is intelligible and pertinent ; if not, it has no tan-
gible meaning for either species. We believe that in this case, where
we have two generic references, a description including characteristics
of two species, and figures of two species, it is most advisable to make
the original description the material from which to unravel the form
which is to be considered authentic.

Locality and position. Forms with parallel sides are found frequent-
ly at Todd’s Fork, Clinton county, and rarely at the Soldiers’ Home
Quarries. Broader forms with less regular sides are common at the
Soldiers’ Home Quarries. Clinton Group.

Genus PH^NOPORA, Hall.

Zoaria forming simple or branching fronds without a distinct non-
poriferous edge ; the pores of the edge seem to be of the same rank
with the interstitial cells. Cells arranged in longitudinal series, sepa-
rated at their ends typically by two interstitial cells, although their num-
ber may be so increased in different parts of the same frond as to even
completely surround the cells. A transverse septum at the base of the
cells is also characteristic. The bases of the zoaria are attenuated and
rounded, or somewhat pointed, showing that articulation had formerly
existed with some fixed base.

VI. Ph^nopora platyphylla, fajnes.

{Plate XVI, Fig. i ; Plate XVH, Fig 6.)

Phaenopora (Ptilodictya) expansa, pars. Hall and Whitfield, including Plate
V, fig. I.

Ptilodictya platyphylla, James, 1879, Paleontologist. No. 3.

Ptilodictya bipunctata (Van C!eve) Hall, 1883. 12th Indiana Geol. Report.

Frond beginning with a small, narrow stipe, which at its origin is
obtusely pointed, or almost rounded, indicating articulation with some
attached base, rapidly widening above into a broad fiabellate expan-
sion, the contour in general being rounded, but flexuous in certain places
where growth has been irregular; never branched. The surface cov-
ered by conspicuous, rounded tubercles, having a tendency to arrange
themselves in rows, about six tubercles appearing in a length of 15
mm ; sometimes the tubercles have a tendency to be somewhat point-
ed. The surface is occupied by the cell mouths, which are very small.

BULLETIN OF THE LABORATORIES

158

circular, or slightly oval, arranged in longitudinal series, about eight
in the length of 2 mm. Typically two interstitial cells are found at
the extremities of the cells; in some specimens, however, additional
interstitial cells appear along the sides of the cell, or even at the ex-
tremities, so that the cells are sometimes completely surrounded by in-
terstitial cells. The cell rows are separated by raised ridges, which
appear like a narrow line running between the rows and closely pressed
by the cells and interstitial cells on either side; or they become quite
broad and poorly defined, bearing on their surface all the laterally sit-
uated interstitial cells, the mouths of which are apt to be of an elon-
gated rather than circular shape; whenever the interstitial cells become
very numerous these separating ridges are apt to disappear entirely in
a disordered mass of cells and interstitial cells. All these changes
may appear in one and the same species. At the summit of the
tubercles one or more cells are apt to be suppressed ; their places are
then taken by interstitial cells. The edges of the frond are acute ; no
non-poriferous margin has been observed, but considering the nature
of the growth of the species, this is rather to be expected. Specimens
are usually found divided in the middle, the epithecal laminae being
exposed, and the celluliferous faces being adherent to the rock
in which the specimens were imbedded. The epithecal mem-
brane is smooth, or wrinkled transversely in curves, which
to some degree mark various stages of growth, and conform
therefore with the general outline of the flabellate frond. Through
the epithecal membrane longitudinal lines may be seen, which are the
laminae that separate the cell rows ; between these are diagonal lines
dividing the surface into small subimbricating rhombs ; sometimes
short transverse lines intersect the diagonal lines of the rhomb. From
the epithecal laminae the cells diverge to the opposite faces of the
frond, making an angle of 65° or more with the epithecal laminae.

Fronds vary in size; one of the largest specimens seen being 100
mm. broad and 130 mm. long. Eight cells are found in the length of
2 mm ; eight or nine rows occupy the same distance measured trans-
versely. The thickness varies from a thin expansion to a frond 2 mm.
thick, rarely attaining a thickness of even 5 mm.

The figure accompanying the original description of Ptilodictya
expansa^ Hall and Whitfield, belongs to this species and the description
of that species shows that specimens of this species were by mistake
used in the determination of its characters. This species is evidently

OF DENISON UNIVERSITY.

159

closely related to Ph. constellata, Hall, from the Clinton Group of Can-
ada. A specimen from Hamilton, Ontario, before me, may be distin-
guished by the fact that the monticules appear only as slightly elevated
patches, and the thickness of the frond is reduced to very small dimen-
sions, perhaps .7 mm, and the frond seems to have been of small size.
Specimens collected by Prof. N. S. Shaler, however, from Anticosti,
Canada, show all the features of our Ohio specimens.

Locality and position. Soldiers’ Home Quarries, Allen’s Quarry,
Fair Haven, Todd’s Fork, Clinton Group.

VH. Ph^nopora MAGNA, Hall and Whitfield.

{Plate XV, Fig. 6; Plate XVI, Fig. 2; Plate XVH, Fig. 7.)

Stictopora magna, Hall and Whitfield, 1875, Ohio, Pal. Vol. II.

Stictopora compressa, (Van Cleve) Hall, 1883, 12th Indiana Geol. Report.

Frond beginning with a narrow stipe which is rounded at its ori-
gin, indicating that its base was articulating, gradually widening, until
it attains a width of about 6 mm, then branching dichotomously. The
dichotomous character of the branching is frequently obscured by the
unequal development of the branches and by the unequal intervals
between the places at which branching takes place. When
the specimens exist only as fragments, pieces of fair size may
sometimes be found which seem to be portions of lengthened, undi-
vided fronds, and it is very probable that species of this genus have
been described as unbranched, simply because the material in hand
was fragmentary. The general appearance of the frond varies, there-
fore, exceedingly, from a long, scantily branched specimen, to one
whose numerous branches look like narrow ribbons woven together.
The angles at which the specimens branch vary exceedingly, from
small angles of only 10°, in which the bending of the branches for
even a slight distance is sufficient to make them overlap each other, or
assume a parallel direction, to angles of 80° or even 90°. The sur-
face is covered by conspicuous tubercles, usually low, broad, and
rounded, but sometimes pointed and well defined, with a less regular
arrangement than in the former species, or even scattered ; about 5
tubercles usually occupy a length of 9 mm, although this is subject to
great variation.

The cell mouths are small, circular, or slightly oval, arranged in

l6o BULLETIN OF THE LABORATORIES

longitudinal series, about eight in a length of 2 mm ; ten or eleven of
these series are found in a width of 2 mm. The longitudinal series
are well defined by thin, slender, raised lamellae, without the complex
structure mentioned in the former species. The lamellae separating
the cells from the interstitial cells appear at the surface like fine threads,
connecting the longitudinal lamellae, and they cross each other at equal
distances between the same, thus enclosing two interstitial cells at the
ends of the cells. In the tubercles they become more numerous and
either surround the cells or entirely supplant the same. The branches
are quite thin and flat; the edges are thin and sharp, and are occupied
by minute pores or cells, corresponding in size to the interstitial cells
and forming only a narrow margin. Interstitial pores are apt to be
numerous in the cell rows along the edges of the branches. Speci-
mens usually divided at the centre, showing the epithecal laminte;
these are wrinkled transversely, the wrinkles being lunate in the mid-
dle of the frond, and deflected backwards on either side to the margin.
The exterior surface is rarely seen.

Fronds vary in size, a well grown specimen being no mm. long
and 80 mm. broad; the branches vary between 5 and 8 mm. in width,
and a form found at Fauver’s Quarry occasionally attains a width of
10 mm ddieir thickness varies between 1.5 and 2 mm.

Locality and position. Soldiers’ Home, Brown’s Quarry (a narrow
variety), and Fauver’s Quarry, Clinton Group.

VIII. Ph^nopora multifida, ( Van Cleve) Hall.

{Plate XVI, Fig. 3.)

Ptilodictya (sp ?) James, 1878, Paleontologist, No. i. (Name, P. JVelskz sng-
gested.

Stictopora multifida, (Van Cleve) Hall, 1883, 12th Indiana Geol. Report.

Frond beginning with a narrow stipe, gradually widening until a
breadth of 4 or 5 mm. is attained, then branching dichotomously at
small angles, the branches remaining parallel. The branches may lie
closely together and almost touch one another. They are rarely more
than their width apart. The usual form is that of a series of parallel
branches forming a sub-triangular frond by means of dichotomous di-
vision, the branches at their tip being a fifth or a sixth of their breadth
apart, and at the base touching one another, sometimes forming a con-
tinuous frond near the stipe, and at other times being open like the

OF DENISON UNIVERSITY.

16 1

branches above. All specimens seen were divided at the epithecal
membrane, which is wrinkled transversely by lines of growth, lunate
in the middle, the ends deflected backwards along the sides, the round-
ed ends of the branches are preserved on some of the specimens. In
specimens whose branches have' become contiguous and have grown
together at the base of the frond, the wrinkles or lines of growth still
indicate readily the position of the branches.

Branches thin and flat, the exterior surface not seen, but the cross-
sections made gave no evidence of tubercles, and therefore the surface
is believed to be flat. Cells oval, arranged in longitudinal series, 8
cells in a distance of two mm, and 10 or ii series occupying the same
distance in breadth. The series of cells are separated by thin, straight
lamellae, which are not intruded upon by either cells or interstitial cells.
Interstitial cells, two, between the ends of the cells, becoming more
numerous in one or two of the marginal series ; the margin is thickly
supplied with them, making it poriferous; poriferous margin narrow.

Frond about 75 mm. long and 70 mm. broad. Branches from
2.5 to 4 mm. broad. Cells, 8 in a distance of 2 mm, measured lon-
gitudinally, 10 or II in the same distance measured transversely.

It will be noted that this species assumes a sort of intermediate
position between the last and the following. In fact the difference in
the width of the cells and the different manner of branching, both
variable factors, alone distinguish them one from the other.

Locality and position. Soldiers’ Home Quarries, collection of Mr.
Geo. Caswell. Also, Brown’s Quarry, a form with more distant
branches. Clinton Group.

IX. Ph^ngpora fimbriata, James.

{Plate XV, Fig. 7 .)

Ptilodictya fimbriata, James, 1878, Paleontologist, No. i.

Stictopora Van Clevii, Hall, 1883, 12th Indiana Geo. Report.

Frond arising from a small narrow stipe, attenuated towards
the base, expanding gradually above until a width equal to
the branches is attained; then branching dichotomously at va-
riable intervals in different or even in the same specimens ;
the branches usually flexuose, forming characteristic meshes upon
the surface of the rock. Surface unknown, but from numer-

i62

BULLETIN OF THE LABORATORIES

ous sections believed to be destitute of tubercles. The branches are
quite thin and flat, with sharp edges.

Cells arranged in longitudinal series, about eight in a length of 2
mm. and ten or eleven in the same distance in breadth. Two intersti-
tial cells are found between the ends of the cells, becoming more numer-
ous in the lateral series of cells, and entirely pervading the tissues of the
edges of the branches, which as a consequence appear striated in worn
specimens. The branches are usually narrower than those of the last
species, eight to twelve series of cells occupying the branches in this
species, whereas in that species twelve to fifteen series are usually
found.

The largest frond so far observed, evidently not an entire speci-
men, was 65 mm. long, and 50 mm. broad. The branches vary from
2.3 to 3.2 mm, and sometimes attain a thickness of 1.2 mm.

Associated with these species are long, slender fronds, undivided,
with the characteristic cells and interstitial cells of the group, the lat-
ter pervading the edges of the frond. One specimen is 55 mm. long
and 5 mm. broad. They are probably the broken off stipes of some
of the species last described. That the species all form a closely allied
group may readily be seen.

Locality a7id position. Soldiers’ Home Quarries, Todd’s Fork,
Fauver’s Quarry, Alien’s Quarry, Fair Haven, Clinton Group. ^

Genus PACHYDICTYA, Ulrich.

Zoaria composed of thick, often irregularly branching fronds, with
distinct, smooth, non-poriferous margins. The cell walls are distinct
and regular, neatly enclosing the oval cells ; at their ends they are
usually approximate, nearly but not quite touching, the cells being ar-
ranged in longitudinal series ; laterally, however, they are always sep-
arated from each other by two quite thick lamellae which are continu-
ous between the cell rows, following up the contour of the cells, but
separated along the middle by a curved or quite straight line, which
sometimes is indistinct. Species of this genus are usually referred to
Stictopora., but in that genus the cells are separated by a series of small
spiniform tubuli.

X. Pachydictya emaciata, sp. n.

{Plate XV, Fig. 8; Plate XVH, Fig 8.)

Frond not known in its entire state, only one specimen (and that

OF DENISON UNIVERSITY. 1 63

a fragment) seen. The specimen is 26 mm. long and 22 mm. broad,
being divided dichotomously into branches at angles of about 45°.

The branches are 3 mm. wide and scarcely ^ mm. thick. The
cells are arranged in longitudinal series, forming at the same time more
or less accurate oblique cross-rows. Cells oval, narrow in the middle
rows, broader in the lateral rows, about 6 occupying a length of 2
mm, and ii series the same distance in breadth; 10 to 13 series are
found on the various branches. The longitudinal series are separated by
raised longitudinal lines, inclined to be flexuose on account of the diagonal
lines, in which the cells dispose themselves ; occasionally these ridges
seem to bear 2 or 3 fine striae. The margins of the branches show
faint traces of striae.

From the succeeding species it may be distinguished by the thin-
ness of its branches, the wider non-poriferous margin, and the greater
number of its cells in transverse measurement. Name signifies thinned
or grown thin.

Locality and position. Soldiers’ Home Quarry, Clinton Group.

XI. Pachydictya bifurcata, {Van Cleve) Hall.

{Plate XV, Fig. 9; Plate XVII, Fig. 9.)

Stictopora bifurcata, (Van Cleve) Hall, 1883, 12th Indiana, Geol. Report.

Frond arising from a narrow stipe, attaining the size of the branch-
es above, then branching rapidly below, less frequently above, at an-
gles between 30° and 50°. The branches are convex and decidedly
thickened, their thickness exceeding half their width. The surface
even and smooth, at least not tuberculate, channeled lengthwise, the
cells placed in the channels, five and a half or six found in a length of
2 mm, and six or seven in the same distance in breadth. The cells
are oval, slightly separated at the ends by the dividing lamellae ; the
longitudinal series are usually separated to quite a marked degree by
thick lamellae, which are marked longitudinally along the summit by
faint undulating stri^. The edges of the branches are non-poriferous
and smooth, or very indistinctly striate, obtuse, but with a narrow sa-
lient margin indicating the position of the epithecal lamina.

The largest specimen found was 160 mm. long and 85 mm. wide;
the branches are somewhat flexuose, about 4 to 5 mm. broad, and

164

BULLETIN OF THE LABORATORIES

from 2 to 3 mm. thick. This form may be compared with P. acuta ^
Hall, from the Trenton Group of New York.

Locality and position. Soldiers’ Home Quarries, Fair Haven.
Clinton Group.

XH. Pachydictya bifurcata, var. instabilis, var. n.

[Plate XV, Fig. 10.)

Frond known only by fragments 30 to 40 mm. long and broad,
branching dichotomously at wide and variable angles. The branches
from 3 to 5 mm. wide and from i to almost 2 mm, thick ; the sur-
face uneven, more or less tuberculated, the tubercles low but gener-
ally distinct, without evident arrangement, about 4 tubercles in a dis-
tance of 80 mm, measured longitudinally.

The cells are oval, from 6 to 7 occupying a length of 2 mm, usu-
ally nearer the latter number, and from 8 to 9.6 rows occupying the
same distance in breadth. The non-poriferous edges narrow in the
specimens examined.

Whether this form is distinct from the last one, it is difficult to
tell. Where there are so many species of a genus, occurring in such
abundance, their form is usually very variable, and the distinctions
between species are not always well defined. Judging from the speci-
men at hand, it is difficult and perhaps impossible to distinguish be-
tween the forms specifically, and intermediate forms seem to occur.

Locality and position. Brown’s Quarry, Clinton Group. The
species occurs here in all its forms apparently. The extreme, nodu-
lated or tuberculated forms, which are separated here as a variety pre-
dominate.

XHI. Pachydictya turgida, sp n..

[Plate XV, Fig. 11; Plate XVH, Fig. ii.)

Fronds variable, branching dichotomously at angles from 30° to
50°; branches more or less thickened, the edges inclined to be obtuse
with a salient line along the epithecal lamina, the margin non-porifer-
ous. Cells oval, 12 in a distance of 5 mm, measured along the lon-
gitudinal series, 16 series in the same distance in breadth. Two or
three faint flexuose lines are found on the ridges separating the series.

OF DENISON UNIVERSITY.

165

The surface is tuberculate ; the tubercles are of variable distinctness,
and are arranged in something like order, from 4 to 5 in a distance of 10
mm. The tissue in the tubercles becomes very thick, the arrange-
ment of the cells is somewhat disturbed and their number reduced.

The largest fragment at hand is 55 mm. long and 35 mm. broad.
The branches vary from 6 to 9 mm. in width, and from 1.8 mm. to
3.5 mm. in thickness.

Name signifies thicks swollen, referring to the thickened fronds.
This form may be compared with P.fenestelliformis, Hall, as identified
by Mr. E. O. Ulrich, from the (hncinnati Group of Illinois.

Locality and position. Soldiers’ Home Quarries, Fair Haven, Clin-
ton Group.

XIV. Pachydictya obesa, sp n..

{Plate XV, Fig. 12.)

The structure of this species is very similar to the last, but the
fronds are broader, apparently undivided, and usually thicker, forming
coarse, often undulating or folded fronds. Tubercles much more dis-^
tinct, with a more decided tendency for arranging themselves in series,
4 to 5 in a distance of 10 mm. 'Tangential sections show that the
number of cells is decreased in the tubercles by the turgescence of the
surrounding laminae, or by the entire suppression of cells. One of
the largest fronds at hand is a Iragment 65 mm. long, 37 mm. wide
and 5 mm. thick. Some specimens are not so thick, but still thick
enough to attract attention to this feature. It may be compared with
P. gigantea, Ulrich, from the Cincinnati Group of Illinois.

Name signifies, very thick "and swollen, fat.

Locality and position. Soldiers’ Home Quarry, Clinton Group.

CYSTODICTYONID.^, Ulrich.

Zoaria consisting of two or more layers, grown together along their
epithecal membranes. Cell apertures with a crescentic lip. Intersti-
tial spaces occupied by vesicular tissue, which in the matured stage is
almost obliterated by a secondary deposit of sclerenchyma, apparently

i66

BULLETIN OF THE LABORATORIES

perforated by minute, vertical, communicating canals. Margins of
zoaria non-poriferous. (Ulrich, Am. Pal. Bry. April, 1884.)

Genus RHINOPORA, Hall-

Zoaria consisting of two laminated expansions, grown together
along their epithecal membranes; the margins are non-poriferous.
The cell apertures are strongly raised above the surface in little papil-
lae or pustules. The aperture itself is quite small and usually appears
more or less irregular in form, suggesting the crescentic lip so char-
acteristic of the CystodictyonidcE and FistuliporidcF,. The interstitial tis-
sue, if any, seems to have been obliterated by the secondary deposit of
sclerenchyma.

XV. Rhinopora verrucosa, Hall.

{Plate XV, Fig. 13 ; Plate XVII, Fig. 12.)

Rhinopora frondosa, Hall .and Whitfield, 1871;, Ohio, Pal. Vol. II.

Escharina (?) distorta, James, 1879. "1"^^ Paleontologist, No. 3.

Rhinopora venosa, Spencer, 1S84, Niagara Fossils, St. Louis Acad. Science,
Vol. IV, No. 4.

Cf. Rhinopora curvata, Ringueberg, Bull, Buffalo. Soc. Nat. Sc., Vol. V,
No. I.

Fronds forming thin expansions, the defining margins being sharp
and distinctly non-poriferous. Specimens usually occur in the form of
fragments, smaller pieces of which appear flattish, and some pieces of
even fair size may be found with only a moderate amount of curva-
ture. However, when broken from the solid rock, parting along the
epithecal membranes, expansions may be followed for 30 mm. or more
through the rock, contorted and curved in almost every possible man-
ner. Proper branching does not take place, but the outlines of the
fronds are often quite irregular. The character of the base of the
frond is unknown. The cells are arranged in diagonally intersecting
rows which may be quite straight for a moderate distance, but usually
are somewhat curved. This arrangement may be perfectly maintained
over quite a large portion of the surface, but frequently is perfect only
in small patches, the rows of which do not perfectly join each other,
on account of the introduction of new rows, the sudden curvature of

OF DENISON UNIVERSITY.

167

a series of rows, or on account of the disturbing influences of the
structure next to be described. Between the cell rows at variable dis-
tances over the frond are distributed a number of raised lines which
are more or less connected with each other and have the appearance
of a branching structure trailing over the surface of the frond. These
may become quite conspicuous and form a marked feature of the frond,
but they do not seem to have any very intimate connection with the
rest of the frond. This they very frequently show by entirely weather-
ing away from the surface of the frond. The place they occupied is
then marked by a groove which becomes quite conspicuous in the
specimens which were characterized by large raised lines. These
raised lines extend along the grooves between the cell rows usually in-
cluding and resting upon the inner half of the cells between which
they extend. Usually they leave the arrangement of the cells unaf-
fected, but the arrangement of the rows may be more or less disturbed
in crossing these lines. At the junction of the raised lines, especially
where several lines meet, the cells are apt to be more separated at this
point than elsewhere on the frond ; the cells then frequently become of
somewhat larger size, are more prominent, and form slightly elevated
clusters of moderate size, over the surface of the frond, which some-
times occur at quite regular intervals and form conspicuous features of
the frond. When the raised lines in such specimens were quite nar-
row and then weathered away, these low elevations are still more con-
spicuous. The center of the elevations is frequently marked by an ir-
regular, non-celluliferous portion where the lines meet ; these spaces
then may suggest maculae. The prominent surrounding cells of the
elevated parts, are frequently crowded back upon each other for a short
distance by the dividing ridges and then also are more inclined to form
conspicuous elevations. The apertures of the cells are produced in
the form of round papillae above the surface of the frond. The mouth
is situated at the very summit of the papillae, but may appear more or
l«ss lateral by the unequal wearing away of the cells. Near the base
on one side of the cell may be found a small depression, the precise
nature of which is unknown. It may have had some connection
with the interior of the frond, but such connection has not been estab-
lished. No interstitial tissue has been satisfactorily determined. The
cells vary from 50 to 60 in the distance of 25 mm. In R. iiibulosa,
Hall^ they are said to be more crowded, numbering from 80 to 85 in
the same distance.

BULLETIN OF THE LABORATORIES

I 68

This species is seen to be quite variable, but there is no difficulty
at all in tracing the connection of the different forms in any collection
which contains a large number of specimens in a good state of preser-
vation. As might be expected, its distribution is also quite wide, ex-
tending from New York to Ontario and Ohio, and being found both in
the Niagara shales and in the Clinton Group.

Locality and position. Brown’s Quarry, Soldiers’ Home Quarries,
Centreville, Fair Haven, Todd’s Fork, Clinton Group.

FISTULIPORlDyE, Ulrich.

This family is closely allied to the Cystodictyonid(B, from which it
differs in the absence of non-poriferous margins and in having no sec-
ondary deposit obscuring the presence of the interstitial cells, or at
least, when present, being quite superficial.

Genus LICHENALIA, Hall.

Zoaria composed of a single layer of cells, the epithecal side be-
ing concentrically wrinkled, the wrinkles being supplemented by sec-
ondary finer concentric stri^; when the epithecal membrane is trans-
lucent, the bases of the cells may be frequently seen in the form of
short, radiating strise. Cells with a crescentic lip at the aperture
which is continued into the tube of the cell in the form of two longi-
tudinal inflections of the cell walls. Interstitial cells always present,
separating the cells.

XVI. Lichenalia concentrica. Hall.

{Plate XVH, Fig. lo.)

No specimens of this species have been found in my own collec-
tions, but it is represented by several specimens in the' cabinet of Dr.
L. B. Welch. The following short description of this species is there-
fore added.

Zoaria forming circular flattened expansions, often 130 mm, in di-
ameter, celluliferous on one side only, the arrangement of the cells
being disturbed in some varieties by the presence of macul^; Cells

OF DENISON UNIVERSITY. 169

separated by angular interstitial cells. Non-celluliferous face wrinkled
concentrically.

Locality and position. Clinton County, Clinton Group, collection
of Dr. L. B. Welch.

CERAMOPORID^., Ulrich.

Zoaria usually incrusting, sometimes ramose with hollow branches,
or flabeilate. Cell apertures triangular or ovate, with a prominent and
arched lip usually on one side. (Ulrich, Am. Pal. Bry. )

Genus CERAMOPORA, Hall.

Usually incrusting. Cells angular, with the lip strongly arched,
the aperture oblique ; cells radiating from one or more centers. (Ul-
rich, Am. Pal. Bry.)

XVII. Ceramopora expansa, James.

{Plate XVII, Fig. 13.)

Alveolites expansa, James, 1879, Paleontologist, No. 3.

“ Corallum, a flat or undulating expansion, irregular in outline, 6
inches or more in diameter, varying in thickness from less than one to
over two lines. Corallites very oblique and more or less sinuous in
their direction from the base or central axis to the surface. Calices
very narrow, slightly curved, elongated slits, showing, generally, when
a little weathered, a tooth-like projection in the middle of the upper
lip, and arranged sometimes in series of short curved rows in a more
or less alternating manner. About 4 calices in the space of a line.
Walls of corallites thick.

“Although the specimen from which this description is made was
found spread over the surface of a rock— from which it readily
scaled off — it is not certain that it was encrusting, as there is an appear-
ance of something like a central axis from which the corallites grew
in different directions to opposite surfaces, in a very oblique manner ;
portions of the side next the rock show calices similar to the other

BULLETIN OF THE LABORATORIES

170

side, but not so distinct, as it is mostly covered by, apparently, indu-
rated clay.” (James, loc. cit.)

Dr. L. B. Welch very kindly showed me the type specimen in his
cabinet. The specimen is very unsatisfactory. The cell apertures
were seen to have a strongly arched lip on one side, and were ar-
ranged in diagonally intersecting rows, about 5 cells in a length of 2
mm. I should be unwilling to attempt any further statements con-
cerning it, and so have repeated the original description. Its general
aspect seemed to be that of a much worn fragment of some species of
Cera7nopora.

Locality and position. Clinton Group, Clinton county; collection
of Dr. L. B. Welch.

xMONTICULIPORID^, Nicholson.

Zoarium with tubular cells, which are thin-walled and polygonal
below, above they are bent more decidedly towards the surface, are
of nearly equal size throughout, more or less thickened and rounded,
but never lipped nor separated by vesicular tissue. Zoaria usually ra-
mose, occasionally frondose, or forming flat circular or irregular ex-
pansions ; never composed of two distinct layers of cells entirely sep-
arated by epithecal membranes.

Genus PRASOPORA, Nicholson and Etheridge.

Zoarium forming a hemispherical mass or a thin expansion, with
a wrinkled epithecal membrane on the lower surface. Cells cylindri-
cal or more or less prismatic, lined on one side with cystoid dia-
phragms.

XVIII. Prasopora parmula, sp 11.

{Plate XV, Fig. 14; Plate XVII, Fig. 14.)

Zoaria forming thin, flattened expansions which are lined by a
wrinkled epithecal membrane on the lower surface ; circular when
young, later becoming more irregular in outline. Typically the lower

OF DENISON UNIVERSITY.

171

surface is concave, corresponding to the convex outline of the upper
surface. Cells of about the same size, occasionally a few are
slightly larger in size, but form no distinct feature in the
growth of the zoarium. Cell apertures polygonal, but rounded and
almost circular, having a tendency to arrange themselves in rows. In
the space left between the outlines of four cells is usually an angular
interstitial cell not always readily recognized at the surface under a
low magnifying power. Cells with cystoid diaphragms along one side,
the ends of the same gradually becoming attenuated and almost meet-
ing on the other side of the wall, thus almost encircling the cells. In
addition to cystoid diaphragms a number of straight diaphragms are
found, which run from the middle of the cystoid diaphragms to the
opposite wall. The interstitial cells are also crossed by straight dia-
phragms, which, however, are far more numerous than those of the
regular cells, being usually twice as many or even more.

Cells, about 8 or 9 in a distance of 2 mm ; in one specimen
about 18 straight diaphragms are found in the length of an interstitial
cell, 9 cystoid diaphragms are found in the adjoining cell, most of
which are connected with a straight diaphragm also belonging to this
cell ; since the thickness of this specimen is about i mm, a very fair
idea of the relative importance of these tissues may be formed. Ex-
pansions vary from 20 mm. to 33 mm. in diameter. The name signi-
fies <2 little shield.

Locality and position. Huffman’s Quarry, Beavertown Marl;
Soldiers’ Home, Clinton Group. Todd’s Fork, in the upper iron-bear-
ing portions of the Clinton Group; this iron-containing layer, which
is here several feet thick, contains almost all the characteristic fossils
of the Beavertown marl.

Genus MONOTRYPELLA, Ulrich.

“ Ramose, smooth or tuberculated. Cells apparently of one kind
only. Walls very thin in the axial portion of the branches, but thicker
in the peripheral region. Diaphragms straight. No spiniform tubuli.”
(Ulrich, Am. Pal. Bry.) The following species is provisionally re-
ferred here on account of the apparent absence of interstitial cells.

172

BULLETIN OF THE LABORATORIES

XIX. Monotrypella confluens, sp. n.

(Flafe XVI, Fig. 4; Plate XVII, Fig 15.)

Zoaria irregularly ramose, branches varying from 5 mm. to ii
mm. in diameter, usually forming coarse, gnarled growths by the irreg-
ular confluence of several branches, which are very characteristic of
this species. Cells vary from 9 to ii in a distance of 3 mm; where
the surface is well preserved, the margins of the cells are seen to be
circular and to be distinctly raised above the surface of the branch.
The margins sometimes touch each other on one or more sides, but
are just as frequently entirely free and distinct, and never are polygon-
ally compressed. The interstitial spaces left between the raised mar-
gins of the cells sometimes have the appearance of small interstitial
cells, but usually they appear simply as depressed areas. In worn
specimens the raised margins of the cells can not be detected and the
inter-cellular spaces then appear simply as thickened cell walls, sepa-
rating. the cells. Tangential sections give no evidence of interstitial
cells in such cases, and in longitudinal sections the cells appear to be
of one kind only. The cell walls in tangential sections near the sur-
face appear very thick, but only a slight distance from the surface they
are seen to be very thin. Straight diaphragms are developed in mod-
erate numbers and are- somewhat more numerous towards the surface,
but the distinction between the mature and immature portion does not
seem to be very great. About 9 diaphragms occur in one of the sec-
tions in a distance of 3 mm ; the number naturally would vary consid-
erably however. In some specimens in which the surface is free from
all sediment, operculate diaphragms seems to extend across the cells a
short distance below the surface of the specimen. Some specimens
also show low elevations about 3 mm. distant from each other, in
which the number of cells seems somewhat reduced. The name re-
fers to the characteristic gnarled expansions formed apparently by the
growing together of branches, the latter becoming confluent.

Locality and position. Soldiers’ Home, Clinton Group.

Genus CALLOPORA, Hall.

“ Ramose to sub-frondescent, smooth or tuberculated. Cell-tubes
cylindrical, their apertures often closed by an operculum, with a very
small central perforation, from which usually radiate small ridges. In-

OF DENISON UNIVERSITY.

173

terstitial cells, more or less numerous, sometimes completely isolating
the proper zosecia. Diaphragms numerous. Spiniform tubuli and
cystoid diaphragms wanting.” (Ulrich, Am. Pal. Bry. ) The follow-
ing species are provisionally referred here on account of an apparently
similar relation between cells and interstitial cells.

XX. Callopora magnopora, sp. n.

{Plate XVI, Fig. 5 ; Plate XVII, Fig. 16.)

Zoaria branching at intervals of about 15 mm; branches from 6.5
to 8 mm. in diameter, rather irregular in form and often with low tu-
bercles of no marked characteristics, and which may be entirely ab-
sent. Cells about 8 in a distance of 3 mm. Cell apertures sub-circu-
lar, the margins not distinguishable at the point of contact, but distinct
and elevated along the rest of the cells, apparently enclosing intersti-
tial cells, these appearances obscured by abrasion. Tangential sec-
tions seem to give better evidence of interstitial cells, these being
smaller, irregular, rather fewer m number, and more or less surround-
ing the more circular cells. In longitudinal sections the interstitial
cells may apparently be also detected, being narrower cells with some-
what more numerous diaphragms. In one specimen there were 10
diaphragms in a length of i mm. in the cells, in the interstitial cells
13 or 14 were found.

This species is readily distinguished from the last by the larger
size of the cell apertures, being about one and a half times the size of
that species. When the number of the cells is approximately the same
this may be accounted for by the fact that, whereas in the former spe-
cies there is a considerable space left between the margins of the cells, in
this species they are united into one cell wall, indistinguishable at the sur-
face. The number of diaphragms is also much greater in this species.
However, if the presence of interstitial cells has been correctly deter-
mined, this offers no ready character for determination, since abraded
specimens and even moderately well preserved specimens are scarcely
distinguishable by superficial examination in appearance from the last
species. The name signifies large pored or celled.

Locality and position. Centreville, Soldiers’ Home Quarry, Clin-
ton Group.

BULLETIN OF THE LABORATORIES

174

XXL Callopora Ohioensis, sp. n.

{Plate XVI, Fig. 6; Plate XVII, Fig. 17.)

Zoaria more regular in formation than the two species last de-
scribed, branches varying from 2.5 mm, to 5 mm. in diameter. Cells
apparently of two kinds. The true cells are of nearly uniform size,
subcircular, and stationed apart at somewhat regular intervals, from ii
to 13 occupying a distance of 3 mm. Separating these cells and
usually completely isolating them are a number of interstitial cells very
variable in size, even in the same part of the branch, some being lar-
ger and some smaller than the true cells, but usually of the same aver-
age size. The true cells are usually in our specimens filled more or less
with sediment and so are more readily distinguishable. Tangential sec-
tions show this feature very plainly. Longitudinal sections do not
show any difierence in size between the true and the interstitial cells,
nor is there any appreciable difference in the number of the straight
diaphragms; these features will distinguish it readily from C. elegantu-
la, Hall. It will be remembered that only under favorable circum-
stances was any difference noted in the number of diaphragms in the
last species. The number of diaphragms in general is but slightly greater
than in that species.

Locality and position. Centreville, Clinton Group.

PLATE XV.

Fig. I. Phylloporina angulata, Hall ; the small form for which the name P.
Daytonensis was suggested by Hall and Whitfield.

Pig. 2. Heminypa Ulrichi. n. sp ; a part of a frond showing the infundibuli-
form structure.

Pig. 3. Clathropora frondosa, Hall ; a part of a frond showing the point
of articulation with some basal structure.

Fig. 4. Clathropoi'a Clintonensis, Hall and Whitfield ; fragment of a frond
showing a somewhat similar provision for articulation.

Fig. 5. Ptilodictya expanse., Hall and Whitfield ; a part of a typical frond
from Todd’s Fork, Clinton County.

Fig. 6. Phcenopom niagna, Hall and Whitfield; a fragment showing the sur-
face.

OF DENISON UNIVERSITY.

175

Fzg-. 7. PhcBnopora fiznbriata, James ; a typical frond, parted along the epithe-
cal membranes; branches frequently found with a looser arrangement.

Fig. 8. Pachydictya emadata., n. sp ; the type specimen.

Fig. 9. Pachydictya bifurcata^ ( Van Cleve) Hall; a large frond showing in places
a pseudo-anastomosis of the branches.

Fig. 10. Pachydictya bifurcata^ var. instabilis, n. var ; one of the extreme
forms.

Fi%. II. Pachydictya turgida., 71. sp , a typical form.

F'ig. 12. Pachydictya obesa, n. sp ; the basal portion of a frond, its articulating
end not discovered; the frond usually widens considerably above and is often de-
cidedly undulating.

Fig. 13. Rhinopora verz'ucosa, Hall ; a, a fragment showing raised branching
lines ; b, a similar specimen in which weathering has caused the same to appear as
depressed veins ; c, a specimen in which the cells at the junction of the veins have
become somewhat more prominent, forming low tubercles.

Fig. 14, Prasopora pai'inula. n. sp ; the type specimen.

PLATE XVI.

Fig. I. Phcenopoi'a platyphylla, James ; a frond, parted along the epithecal
membrane.

Fig. 2. Phcenopoi'a magna, Hall and Whitfield ; a frond, parted along the
epithecal membrane.

Fig. 3. Phcenopora multijida, {Van Cleve) Hall; a typical specimen from the
collection of Mr. Geo. Caswell ; parted along the epithecal membrane.

Fig. 4. Monotrypella conjluens, n. sp ; a, a branch ; b, a typical gnarled ex-
pansion.

Fig. 5. Callopoi'a magnopora, n. sp ; a branch.

P'ig. 6. Callopoi'a Ohioensis, n sp ; a branch.

-5^

PLATE XVII,

Fig. I. Phylloporina angulata, Hall; a, celluliferous side ; b, non-cellulifer-
ous side ; c, a tangentitial section.

Fig. 2. Hemitrypa Uli’ichi, n. sp; a, the network covering the celluliferous
side ; b, the non-celluliferous side ; c,.a tangential section.

L-

176

BULLETIN OF THE LABORATORIES

Fiq. 3.' Clathropom frondosa, Hall ; a tangential section.

Fig. 4. Clathropom Clintonensis, Hall and Whitfield ; a tangential section.

Fig 5. Ptilodictya expansa, Hall and Whitfield; a, a part of the surface; b,
a tangential section.

Fig. 6. Phcenopora platyphylla, James ; a, a part of the surface; b, a tangen-
tial section.

Fig. 7. Pcenopora magna^ Hall and Whitfield ; a part of the surface.

Fig. 8. Paehydirtya emaeiata,, n. sp ; a part of the surface.

Fig. g. Pachydictya bifurcata., ( Van Cleve) Hall ; a, a part of the surface ; b,
a tangential section.

Fig. 10. Lichenalia concenh'ica. Hall ; a part of the surface, where it has been
worn or emacerated, showing the angular intercellular spaces. Copied from Hall,
Geol. Surv. Ind. nth Rep., Plate 5, Fig. 6.

Fig. II. Pachydictya turgida, n. sp ; a tangential section.

Fig. 12. Rhinopo7'a vei'tMcosa, Hall ; a tangential section.

Fig. 13. Ceramopoi'a expansa^ James ; a few cell apertures, as shown by a part
of the surface of the type specimens. From a sketch taken from the type specimen
in the collection of Dr. L. B. Welch.

Fig. 14. Prasop07'a parmula. n. sp ; a, a tangential section ; b, a vertical sec-
tion.

Fig. 15. Monotropella confiuens, n. sp ; a, a part of the surface ; b, a tangen-
sial section ; c, a vertical section.

Fig. 16. Callopora magnopora; n. sp ; a, a part of the surface ; b, a tangential
section ; c, a vertical section.

Fig. 17. Callopora Ohioensis, n. sp ; a, a part of the surface ; b, a tangential
section ; c, a vertical section

Bullstln of the LaboratariGS ut BEnisGii UnivBrsity.

Vnl. II,

Fig, ^

PLilTE X.

/

I

BullBtln nf the LahoratoriBS nt HlBiiisBn UnivBrsity

YoL II,

PLATE XI,

BullEtln nf the LatinratariES nf BEiiisnii UnlvErslty,

■yal, II.

PLATE XII,

BullBtln of thB LabaratBriBS nf BBnlsnn UnivBrsity.

VdI, II,

FLUTE XIII.

BullBtin at the LabaratariBS nf LlBnisBii UnivBrsity,

IZ-Ql, II,

PLATE XIT.

Bull, Lab, nail. Univ.

ITdI. it.

PLITE X¥.

Bull, Lab, Beu, B'nlv,

Vnl. 11,.

PLITE XYL

OF THE

Scientific Laboratories

OF

DENISON UNIVERSITY.

EDITED BY

C. L. HERRICK, M. S.,

PROFESSOR OF GEOLOGY AND NATURAL HISTORY.

GRANVILLE, OHIO:
Downs & Kussmaul, Printers.
December, 1885.

Table of Contents.

Page.

Editorial statement 3

I. Osteology of the Evening Gros,h&2ik~IIesperiphona vespertina Bonap.,

with plate I and Frontispiece, (Ed.) 5

II, Metamorphosis of Phyllopod Crustacea, with Plates V-VIII and Plate

X, (Ed.) - 15

III. Superposed Buds, with Plate XII, by Aug. F. Foerste, Class of ’87 25

IV. Limicole, or Mud-Living Crustacea, with Plate IX. (Ed.) 37

V. Rotifers of America, Part I, with Descriptions of a New Genus and Several

New Species, with Plates II-IV and Plate X, by C. L. Herrick 43

VI. The Clinton Group of Ohio, with Descriptions of New Species, with

Plates XIII and XIV by Aug. F. Foerste 63

VII. A Compend of Laboratory Manipulation, Chapter I, Lithological
Manipulation, Accompanied by a Condensed Translation of Eugene

Plussak’s Tables for the Determination of Rock -forming Minerals 122

Natural History Department of Denison University

College Directory for Ohio, etc

The Young Ladies’ Institute,

GRANVILLE, OHIO.

BlfiJi Year. 18ta Year with ISif. Graduates,

UNDER THE PRESENT ADMINISTRATION.

CLASSICAL, SCIENTIFIC AND PREPARATORY DEPARTMENTS,
MUSIC, VOCAL AND INSTRUMENTAL. DRAWING 'AND
PAINTING. CHINA' !:PAINTING, &c., &c.

g^^French 'and German Vithout extra charge to regular pupils.“@®[

Address, D.~ SHEPARDSON, D.^D.,

Granville, Licking Co., Ohio,

BULLETIN

Scientific

Denison University,

EDITED BY

C. L. HERRICK, Dep’t. of Geol. and Nat. History,

AND

A. D. COLE, Department of Chemistry and Physics.

GRANViLLfi; ' Ohio, May, 1887.

OF THE

Laboratories

OF

TABLE OF CONTENTS.

Part I.

I. A sketch of the Geological History of Licking Co., Ohio, accompanying
an Illustrated Catalogue of Coal-Measure Fossils from Flint Ridge. By
C. L. Herrick, assisted by classes of 1886 and 1887. Part I, with plates
I- VI., p. 4-68. Appendix 1, Notes on Carboniferous Trilobites. By C.
L. Herrick, with plate VI, p. 51-64. Appendix II. A Waverly
Trilobite. By C, L. Herrick, with plate VH, p., 69-70. Appendix III.
Coal-Measure Bryozoa from Flint Ride. By A. F. Foerste, with plate
VH. p. 71-88.

H. The Clinton Group of Ohio, Part H. By A. F. Foerste; with plate VHI,
p. 89-110.

HI. On the Determination of the Horizontal Component of the Earth’s Mag-
netic Force. By L. E. Akins, Instructor in Denison University ; with
plate IX, p. 111-114.

IV. List of Algse collected near Granville, O. By H. L, Jones, class of '86

p. 1 1 5-^116.

Part IL

V. Geology and Lithology of Michipicoten Bay, Lake Superior. Results of

Summer Laboratory Session of 18S6. By C. L. Herrick, W. G. Tight, ’86,
and H. L. Jones, ’86 ; with plates X-XHI, p. 1 19-143.

VI. Sketchof Geological History of Licking Co., O., Part H. By C. L. Her-

rick; with plate XIV, p.

VII. The Clinton Group of Ohio. Part HI. By A. F. Foerste ; with plates

XV-XVI, p. 149-176.

Denison University,

GRANVILLE, OHIO,

Has a beautiful and healthful location; a large and able faculty; Classical and
Scientific courses of study ; Preparatory and Collegiate departments ; a number of
Free Scholarships ; an excellent working Library ; four Laboratories and a Work-
shop with steam lathes and iron- and wood working machinery ; ample Chemical
and Physical Apparatus; special provision for advanced students ; good buildings.

EXPENSES UNUSUALLY LOW.

Fall Term begins Wednesday, Septembers, 1887.

FOR CATALOGUE AND FURTHER INFORMATION, ADDRESS

GALUSHA ANDERSON, President.
Granville, Licking Co., Ohio.

MM