aN

SN

~

s

eS
*

WARS
SN
SSN

AS AN

NN
BY

Se

AS

SS

" AN

S
aa eel
~~
SSNS

Ree

SNES
ASS

Y SANE.
SN
WN

OY WS
RY
AX

RAS
WALS

OS Sek RP ‘ REN Tee

Avie

w

aes

ARENT SS.'

SSS
aa

a

FROM THE

Library of Rhoda A. Esten

A teacher and supervisor in the schools
of the City of Providence from January,
1878, to May, 1901.

Donated to this Library under tbe
provisions of ber will.

-

ee

MOE

1OHM/18WW

ous
-

Sh iow Sa
ee oe!

alia

. ye ter

yea

Were a ete tae a.

he,

ANALYTICAL KEYS
TO THE

GENERA AND SPECIES

OF THE

FRESH WATER ALGE

AND

The Desmidiee of the United States,

FOUNDED ON THE CLASSIFICATION OF
THE REV. FRANCIS WOLLE’S MONOGRAPHS,

BY

DR. ALFRED C. STOKES,

Author of “Microscopy for Beginners;” “A Contribution toward
a Natural History of the Fresh Water Infusoria
of the United States,” etc.

PORTLAND, CONN.:
EDWARD F. BIGELOW, PUBLISHER.

1893.

Entered according to act of Congress, in the year 1893, by

L. F. BIGELOW, Publisher,

in the office of the Librarian of Congress, at Washington.

Sto

CONTENTS.

Explanation of Plate, - -
Value of of Mikrons in parts of an inch,
Introduction, : - -
Key to the Classes of the Fresh-water Alga,
Key to the Genera of the Fresh-water Algz,
Key to the Species of the Fresh-water Alge,
Key to the Genera of the Desmidiez,

Key to the Species of the Desmidiez,
Glossary, - : -
Index, ~°*- . . .

Value of Microns (/) in fractions of an inch.

fd Inches.| yw Inches.| ym Inches.| yw Inches.| yw Inches.
I,.0=I-25000 | 18.0=1-1383 | 45.0=1-533 | 79.0=1-316 | 113.0=1-221
* 1.5=1-16666 | 18.5=1-1351 | 46.0=1-543 |80.0=1-312 | 114.0=1-219
2.0=1-12500 | 19.0=1-1315 | 47.0=1-532 | 81.0=1-308 | 115.0=1-217
2.5 = I-10000 | 19.5 =1-3333 | 48.0=1-521 |82.0=1-304 | 116.0=1-215
3.0= 1-8333 | 20.0=1-1250| 49.0=1-510 |83.0=1-301 | 117.0=1-213
3.5 = 1-7222 | 20.5=1-1214| 50.0=1-500 |84.0=1-297 |118.0=1-211
4.0==1-6250 | 21.0=1-1143 | 51.0=1-490 |85.0=1-295 | 119.0=1-209
4.5=1-5555 | 21.5=1-1162 | 52.0=1-480 |86.0=1-291 | 120.0=1-208
5-O=1-5000 | 22.0=1-1131 | 53.0=1-471 |87.0=1-287 | 121.0=1-206
5-5 =1-4545 | 22.5=I1-1111 | 54.0=1-464 | 88.0=1-284 | 122.0=1-205
6.0= I-4333 | 23.0=1-1087 | 55.0=1-454 |89.0=1-281 | 123.0=1-203
6.5=1-3846 | 23.5 =1-1064|56.0=1-446 |90.0=1-277 | 124.0=1-201
7.0=1-3285 | 24.0=1-1042 | 57.0=1-438 |91.0=1-274 | 125.0=1-200
7.5—=1-3333 | 24.5=1-1020 ,58.0=1-431 |92.0=1-271 |126.0=1-198
8.0=1-3125 | 25.0=I1-1000 | 59.0=1-423 |93.0=1-268 | 127.0=1-196
8.5=1-2941 | 26.0=1-961 |60.0=1-416 |94.0=1-266 | 128.0=1-195
9.0=1-2777/27.0=1-926 |61.0=3-409 |!95.0=1-263 | 129.0=1-193
9.5 =1-2631 | 28.0=1-893 | 62.0=1-403 |96.0=1-260 | 130.0=1-192
10.0=1-2500! 29.0=1-862 |63.0=1-396 |97.0=1-259 | 131.0=1-191
10.5 =1-2381 | 30.0=1-833 |64.0=1-390 |98.0=1-255 | 132.0=1-189
II,O=1-2272 | 31.0=1-806 | 65.0=1-384 |99.0=1-252 | 133.0=1-188
II.5=J-2173|32.0=1-781 | 66.0=1-378 | 100.0=1-250| 134.0=1-186
12,0=1-2166 | 33.0=1-787 |67.0=1 373 | 101.0=1-247 | 135.0=1-185
12,5 =1-2000 | 34.0=1-706 |68.0=1-368 | 102.0=1-245 | 136.0=1-183
13.0=1-1923 | 35.0=1-714 |69.0=1-390 | 103.0=1-242 | 137.0—1-182
13.5=1-1851 | 36.0=1-694 | 70.0=1-357 | 104.0=1-240/138.0=1-181
14.0=1-1785 | 37.0=1-675 | 71.0=1-352 | 105.0=1-238| 139.0=I1-179
14.5=1-1724 | 38.0=1-657 | 72.0=1-345 | 106.0=1-235 | 140.0=1-178
15.0=1-1666 | 39.0=1-641 | 73.0=1-342 | 107.0=1-233| 150.0=1-166
15.5=I-1612 | 40.0=1-625 | 74.0=1-337 | 108,0=1-231|175.0=1-142
16,0=1-1562|41.0=1-609 | 75.0=1-333 | 109.0=1-228 | 200,0=1-125
16.5=1-1515 | 42.0=1-593 |76.0=1-328 | 110.0=1-227
17.0=1-1470 | 43.0=1-583 |77.0=1-324 | I11.0=1-225
17.5=I-1421 | 44.0=1-567 | 78.0=1-320 | 112.0=1-223

Explanation of Plate.
[FRONTISPIECE.]

GENERA OF DESMIDS.

Each Figure is numbered to correspond with the number of the genus,

FIG,

CON AKHAW D4

IO,

Gonatozygon. Omitted; the cell needs no figure.
Genicularia.

Hyalotheca.

Bambusina.

Leptozosma. Omitted; the cell needs no figure.

- Desmidium.,

Phymatodocis.

Sphzrozosma.

Onychonema.

Mesotznium.

Spiroteenia.

Penium.

Closterium; three figures, showing central inflation and ends
produced into beaks.

Docidium.

Triploceras; end and part of cell.

Calocylindrus.

Cosmarium.

Tetmemorus.

Xanthidium..

Arthrodesmus; 20a, front view, 4, end, view.

Euastrum.

Micrasterias; five forms.

Staurastrum; four forms; 23a, front view, 4, end.

Pediastrum; three forms.

INTRODUCTION.

To know the origin of any object, event or act, is always of in-
terest. To know what lead up to a certain acceptable innovation or
aid is pleasing to everyone, and often important to the historian of
any department of the world’s work. What was the form of the first
analytical key, who made it and what induced him to make it, are in-
teresting questions that the writer at least cannot answer. Such
tables have become very popular in the various departments of. bot-
any and of zoology, but who originated them is not known; nor
when the first was published, nor where. Like many other good
things, these keys may have been the result of simultaneous thought
and experiment on the part of several workers that felt the need of
some outside aid to the inside treasures of the ever increasing mass
of scientific knowledge. But to whomsoever belongs the credit of or-
iginating these devices, to him belong much praise and many hearty
thanks.

That analytical keys were needed is proved by their popularity.
They are welcomed by the student in all the sections into which Na-
ture is for convenience divided. It is true that there are some ob-
servers who scoff and laugh in derision when “keys” are mentioned,
but these few belong to that class, fortunately limited, whose mem-
bers are unable to usethem. There are persons that seem to be de-
ficient in those mental qualities that make the use of such tables a
pleasure and a delight, as there are others unable to arrange even
the simplest of keys. If in a scheme of the kind there are three
groups, a blue, a black anda green, these unfortunate opponents of
keys seem unable to decide what to do next, when the specimen hap-
pens to be green whilethe first description in the list calls for a blue

‘

12 INTRODUCTION,

object. That they should glance down the list tosee if by any
chance a green specimen may have been provided for, does not oc-
cur to them; they toss the paper aside, and laugh at the utter folly of
the statement that any intelligent person should be able to use a
key. The truth is that inability to use these valuable aids is an evi-
dence of adefect inthe mental organization. Such critics are forced
to page through the monographs they attempt to study, with great
loss of time and with much labor, to find the information that may
be wanted; whereas with the object and a key to its class in hand the
labor becomes a delight, and the result a valuable acquisition, be-
cause no key to any department can be used evento a limited extent
without teaching the student many facts that he might otherwise have
overlooked.

A table of the kind will draw attention to the morphology of the
object in a way that will lead not only to its proper classification,
but to something much more important, the enlarging of the stu-
dent’s powers of observation. Some of those that oppose the use of
artificial keys are themselves compelled not only to page through an
unfamiliar monograph, but in many instances to scan the pictures for
the light they are’ groping after; and failing pictures they guess as
to the character of the object from its resemblance to something re-
motely similar, and in the end, at great expense of time, and perhaps
of temper, may get aclue that may lead them to the goal they have
been so laboriously seeking. With the intelligent use of an artificial -
key the place, the character, and even so unimportant a matter as
the name, can be rapidly obtained, and the student be led on to fur-
ther study and investigation.

It is always encouraging to feel that by one’s efforts a way has
been opened to further conquests, or even that a path has been cut to
some previously unknown view. This the use of artificial keys
always accomplishes. When the beginner feels that he can do some-
thing unaided he is inspired to do more. When he feels that he has
travelled alone through some pathway in some department
of natural science, he is anxious to go further. One step taken
with the aid of an artificial key is sureto be an encouragement toward
another. The powers of observation are increased. The ability
to balance one thing against another is cultivated. In a word, an
artificial key can be made one of the most important aids in the
mental development of the beginner that can be imagined. The ob-
server that scoffs at these aids, the observer that refuses to take
advantage of them, is doing a foolish thing and losing a good one.

INTRODUCTION, : 13

There are two distinct varieties of these valuable aids, the nat-
ural and the artificial. The former is founded only on the charac-
ters that the advanced scientist uses in his classification. These are
often so exceedingly natural that to learn the proper position of the
object it must be destroyed. To learn something of an animal
through them the animal must be dissected, and the anatomy of its
nervous system, and the morphology of its osseous system, and the
structure of its heart be accurately observed before it can be
classed. These arrangements may be, they often are exceedingly
valuable to the advanced scientist; to the amateur and the beginner
they are terrible. They haunt his dreams like horrid night-mares,
provided he is incautious enough, or ignorant enough to attempt to
use them. I have not a word to say against such analytical tables.
I commend them for use in their proper places. They are important
for their purpose, but that purpose cannot be the beginner’s or the
amateur’s. It is the learned man that can delight his soul with such
a scientifickey. To him itisinstructive and helpful. Toany one else
itis a bugbear anda horror. The beginner is not prepared to begin
with the nervous system of his ‘‘find,” or even with the structure of
its heart. He must have something nearer the surface and more easily
seen than are these parts. His key must deal with the external and
the evident characters. It is for him that the artificial key is in-
tended, and to him it is inspiring and helpful.

This second kind of key, this artificial kind, is as its name indi-
cates, founded not on what the advanced investigator would use in his
classification of the animal or the plant, but on some obvious, prefer-
ably external, points that may be of no use in the art of classification,
but that can be used as crutches to help the student over the miry
and the stony ground to the hills of science where he will be ,able to
look back and smile at his former helplessness. These artificial
keys have this for their object, and only this. They aim to help over
the hard places; to encourage the user to go further, and ‘to do mote,
so that finally he may become an expert, when he will. no, longer
need any but the natural aids, or may even get along without any
other assistance than skilled eyes and a “learned touch.”

The beginner, however, must have a guide, especially if he be
trying to work alone. This is true in every department of natural
science. It is especially true in microscopy. The field is so im-
mense, the outlook so vast, the work so apparently endless, that with-
out an aid the beginner at once begins to flounder in his sea of
troubles, and before long he sinks discouraged to rise no more. He

~

14 INTRODUCTION.

becomes so disheartened since everything is so new and strange, and
there seems to be no one within call to lead him out of the difficult-
ies, or out of the embarrassment of scientific riches, that he is entirely
discouraged, his enthusiasm is lost, and with this loss is abandoned
a study that would have lessened his cares, increased his joy in living
and lengthened his life. The beginner working alone wastes much
time. ‘To be sure, he may before long learn that a green object that
stands still is a plant, or may be; and also before long he hears that
all green microscopic objects that stand still are not always plants.
If he have a teacher his condition is a more favorable one; but if he
be alone he must have an artificial guide, or fail. For such students
the artificial keys are providential. | Once introduced to them he is
ready to go on to new conquests, The use of such tables in the
popular treatises on botany has done more to popularize that beautiful
study than a score of learned monographs on the subject. As soon
as the pupil learnsthat he can by his own efforts obtain even the bo-
tanical name of his plant,a feeling of enthusiasm fills his heart, and he
is eager for another specimen to analyse. And in the analysis he is
learning the principles of classification, the structure of. the specimen
and the function of the various organs. By means of the key he goes
with little trouble and waste of time to the order, there he finds
another key that leads him pleasantly to the genus, and perhaps a
third that takes him to the species. There he finds the plant exactly
described. He has had the prominent characters brought to his no-
tice in a pleasing way, and the final result is that he not only learns to
love the science of botany, but that he soon learns to know at a
glance, without the use of the artificial key, to what order a strange
specimen may belong. He has become scientific without knowing

“how he*became so. Hehas travelled by the royal road. It is so, or

should be so, in the science of microscopy, to call for convenience a

‘sciéncé that which is really a combination of all the sciences.

If every department of microscopy could have an artificial key to
open the doors of its treasure-houses, the amateur would have a hap-
pier time, science would be benefitted and the maker of the key, the
scientific artisan, would himself be blessed both in this world and in
the next. Such a pleasing state of affairs can not be attained. The
doors are too numerous to be opened by a single key. To make the
proper number is not possible for one worker, however willing he may
be to try. Each specialist could forge a key to the doors or to the
dark passage-ways of his special scientific castle, and offer it to those
that would follow after himif they could. But the specialists are not

INTRODUCTION. ace C

disposed to become scientific blacksmiths, and to forge keys to the
treasures they have locked up in their formidable monographs. In-
deed, it is not possible that they should. Theyhave no time to make
the entrance ways easy and agreeable. They are after the facts of
the science; they are seeking the internal secrets of the creatures
they have studied and written about; they are content to leave the en-
larging of the building to other specialists that may come after. It is
no fault of the writers of learned monographs that they put forth
their treatises without a single loop-hole of entrance for those that
would, if they could, enter in to see some of the treasures of which
rumor has told. When a man has spent his days and his nights and
his earthly and bodily substance on the production of a treatise that
shall make his name known to the world, he is naturally disin-
clined to labor longer and harder to make easy grades and smooth
paths and shady retreats along the way to his treasure house; and
when the learner has arrived.at the gates, the learned man is not dis-
posed to stop his further investigations to throw a pretty key out of
the window and ask the uninvited guest to come in and sup with him.
He is too busily engaged in the new investigation that his completed
investigations have made necessary. There is no end to the questions
to be studied and decided. He cannot, muchas he may be willing,
condescend to make keys for the beginners. If he makes any at all,
‘they will be of the severest kind and intended for his scientific equals
only, not for the humble followers in his foot-steps. We should
never blame the writers of learned monographs for not offering these
gilded keys. They cannot. They have gone up too high to stop, for
the higher they go the more there is to be done. Andthey that have
climbed that high are the ones best adapted to climb higher, for they
find it easier to go up than to come down.

But if such books are to be used by any others than the rather
limited class of experts that have the knowledge needed to find their
way unaided through the pages, then a guide of some kind must be
furnished. An index will not answer the purpose, as to use it de-
mands just that information not at the disposal of the novice orof the
amateur. All of these scientific treatises may be as useful to the
modest student as to the learned investigator, provided, as I have so
often said and repeated, some means can be devised by which he
may be helped to make an intelligent entrance into its various depart-
ments.

Mr. Wolle’s monographs on the Algz and the Desmids are no
exception to the rule. They are not adapted to the use of the ama-

16 INTRODUCTION,

teur microscopist in the state in which the author has left them. It
is not possible for the youthful microscopist to read the description
of one hundred and twenty genera of Algz in order to locatea
single specimen that he may find in the wayside ditch. To ascertain
with any degree of comfort the probable resting place of the speci-
men he must have some help. It is that help that this little compila-
tion hopes to supply. By its intelligent use the student may ascer-
tain the specific name of any fresh water Alga or Desmid in the ponds
and the ditches of the United States. This he can do with the ex-
penditure of the least time and labor, leaving them to be spent in the
subsequent study of the plant, after he has had the satisfaction to
learn what it is, and where inthe classification it belongs. If the
worker has the name of the specimen, he then feels that he has a sup-
port on which he may hang his subsequent information, and a starting
point for further investigations. Not to know the name of the ob-
ject and yet to try to study it, is like an attempted conversation with
a stranger whose antecedents and local habitation are unknown.
The effort is not an agreeable one. Theconversation languishes, and
interest is lacking. The name and the habitat of the person add
much to the pleasure of the meeting, and many suggestions to the in-
terview. So the name of the microscopical or other specimen is al-
most essential to the well being of the young student.

The name is, too, about the first thing the advanced scientist tries
to learn. It is impossible to do otherwisé. The object can not be re-
ferred to by speech or in writing until its name is known; what other
workers in other parts of the world may have said about it or done
with it, can not be known until its name is learned, as without the name
all indexes are closed in all the books of all the libraries. The name
is the clue to further knowledge, its starting point, even the hook upon
which further information is to be hung. Whatever advanced scien-
tists may say to the contrary, their first effort, perhaps it is an uncon-
scious one, but their first real effort is to ascertain the name of their
new specimen. If it has none, they at once proceed to give it one.
All the wild talk about the undesirability of learning the name is
wrong in principle. ‘The name is, as every one will cheerfully admit,
only of secondary importance when compared with a study of habits
or of morphology, but it is as essential, since it is and must ever be
the starting point for further investigations, at least on the part of the
amateur. If he chooses to stop at the name, that is his misfortune;
but even then he has gained something. If those whom I may be able
to help by these keys shall do nothing more than identify their

INTRODUCTION. A

“finds,” I shall feel that Ihave done some little thing to help them
and their friends. I shall feel pretty sure that the mere finding of
the name will not be the end; but if it should be, where will be the
harm? Is it acrime to know the scientific name of the plant or of the
animal? Knowing that is knowing something, I think. Would you
have the pupil dissect the nervous system before he has learned to
recognize a nerve, or before he knows the muscles to which the nerves
are distributed? Of course he might say ‘“‘This is a nerve,” and “That
is a nerve and it goes to that muscle,” but would you have him carry
the dead body about with him in order to dissect it and point out the
nerves and the muscles that receive them whenever he wished to com-
municate with you or with any of his friends in reference to the nerves
and the muscles of that special creature? This is exactly the result
which those that cry out against learning names would accomplish
if their desires prevailed. No, no! Get the name the very first
thing, if you wish. It will make a good starting point. It is not the
end and the aim of any study; it is only the bridge that takes us over
the swamp. . After awhile we will be big enough and strong enough
to pass the swamp without the bridge, as after awhile we will be able
to get along without an artificialkey. But do not condemn the bridge
that has carried you safely over.

The keys in this little book are as artificial as they could be made.
In some instances they are perforce somewhat natural; that is, the
fruiting plant has been used to the exclusion of the more frequent
sterile condition. This, however, has been avoided as much as possi-
ble, and in several instances two keys have been prepared to the same
genus of plants, one for the fertile, the other for the sterile filaments.
They are all, as the title page indicates, founded on the classification
contained in the admirable monographs by the Reverend Francis
Wolle on the fresh water Algze and the Desmids of this country. Un-
til Mr. Wolle took up the subject our American microscopic plants
had scarcely been touched, except by a few observers in a desultory
way. Hehas brought order out of chaos, and has prepared two mon-
ographs that are monuments to his learning, skill, care and patience.
These keys are made not alone with the object of leading the begin-
ner to the study of the fresh water Algz and the Desmids, but to in-
troduce him to these fine works of Mr. Wolle’s. While the beginning
mcroscopist in his study of microscopical botany may, toa certain ex-
tent, succeed in identifying his “finds” with these keys alone, to do
so with entire satisfaction he should have access to the monographs
on the Algz and on the Desmids. The references at the end of the

18 INTRODUCTION,

classes and of the genera are to the numbers preceeding those classes
and genera in this list; those following the species are in every case
for reference to the pages on which will be found the extended de-
scriptions in the monographs already so often referred to, where ref-
erences will also be found to the illustrations.

The measurements of the Alge are given in parts of amikron (j);
in the Desmids, by both fractions of an inch and of mikrons. The
former will necessitate a little calculation, if the reader is not en-
tirely familiar with the minute space called a mikron and represented
by the Greek letter 4. It measures the 5,4,, of an inch in length, and
the calculation needed to bring it to the fractions of an inch as given
in the measurements of the Alge, are slight. Twenty-five mikrons,
for instance, being 55,5 inch, or z;45 inch. It is only necessary
therefore to use the number of mikrons as given with the Algez for
the numerator of a fraction of which the 25000 forms the denomi-
nator, and reducing the whole tothe lowestterms. Inthe Desmids the
calculations have been made, and the measurements given in both
forms. ‘The student will therefore need an eye-piece micrometer, but
it may be ruled to parts of an inch. The use of the mikron, like the
use of the metric system, has not and probably never will come into
popular favor.

Does the reader know how to use a key of this kind? To some
this appears to be a mysterious thing, although a little inspection of
the key itself should make it plain. It is simply a matter of exami-
nation, comparison and rejection. With the specimen in hand, which
in this instance means under the microscope, begin at the beginning
of the key and compare the description in the first sentence with the
object under the instrument. Do the two agree in every particular?
If not, leave that reference and go to the next having the same letter
or other symbol at its front. If that should describe the specimen,
notice the letter in the parenthesis at the end of the line, and seek
that same letter at the beginning of a line in some other part of the
key. You will probably find several lines beginning with that letter.
Starting at the first, compare the description there given ina word or
two with the actual specimen, and if it does not agree pass to the line
next below. If at the end of this line there is another reference let-
ter in parenthesis, turn to that, and so continue until at the end of
some line you find the generic or the specific name of the plant. Mis-
takes are easily made, here as elsewhere. If you should happen to
make one at the start every step forward will lead you further and
further astray. With care and intelligent observation, errors may be

INTRODUCTION, 19

avoided and the specimen readily run down to its proper place. Af-
ter a little practice, the use of such artificial keys becomes a great
pleasure. The benefit has already been referred to. Theonly secret
of their successful use is to be certain that each progressive step is
right before it is abandoned for the next. And after a little practice,
too, the student will become so familiar with the Algz or with the
Desmids that he will not need to apply to the generic keys for aid,
but will be able toturn at once to the proper genus, and there use the
keys to the species; and with a little further experience he will be en-
abled to recognize at a glance the species, and then will be prepared
to proceed with his investigations, or to refer intelligently to the ob-
ject so as to communicate with his friends and fellow workers in re-
gard to it. It is as impossible to speak or to write of an Alga or of a
Desmid without using its proper name, as it is to speak or to write of
your most intimate friend without using his. )

Alge and Desmids are singly invisible to the naked eye. It is
only when they occur in large masses that the eye can take cogni-
zance of them. It'rarely occurs, however, that the Desmids are so
abundantly congregated that they thus obtrude themselves on the
observer. When a large quantity has been collected and the vessel
placed near a window, they will collect ina green film at the surface
of the water on the lighted side, and there become visible in mass.
In the ponds and shallows such an occurrence isnot common. At
times they are found so abundantly that by holding a glass vessel of
the water up to the light they may be seen floating about as minute
green objects, which the trained eye will recognize and the pocket
lens make distinct. But these varieties are among the largest of the
forms; according to my experience they are always exclusively con-
fined to the Closteriums. Other large forms, like JZicrasterias, at
least in the writer’s locality, rarely occur in such profusion... To col-
lect the Desmids, therefore, it is necessary to collect by faith. The
microscopist can know exactly what he has only when he gets home
and examines the water drop by drop under the microscope.

With the Alge it is different. These are usually visible to the
naked eye, as they are almost invariably collected in large masses
floating on the surface, submerged just beneath the surface, or at-
tached in waving tufts or fringes to sticks and stones and other
plants in the ponds. ‘The eye of faith is not needed to recognize
them. They usually force themselves on the wondering attention of
the observing pedestrian in the wayside lanes, beside the ditches and
slow brooks. As soft emerald clouds, or graceful streamers floating

20 INTRODUCTION.

in the sluggish current, or resting like a green skum on the surface,
they are readily seen and as easily gathered. No collecting tools are
demanded for either Algze or Desmids, except a dipper of some
kind, a common tin dipper is as good as anything, and a few bottles
or other vessels to carry the treasures home, and to keep them con-
cealed from inquisitive people; the collecting naturalist must always
be prepared for a meeting with such persons.

Many media have been recommended for the preservation of these
beautiful plants. Thé trouble with the majority of these prepara-
tions is that they will in time, some usually ina very short time,
allow the cell contents to contract and to become so distorted that
the object is worthless for any serious study, and worthless, too, as
the object of beauty that it was when first mounted. Some of the
commended media act well on some kinds of Algz and Desmids, but
fail on others. The following are among the best, yet even these are
not all adapted to all the different kinds. They are mentioned in
the order of their excellence.

CAMPHOR WATER.—This is made by placing a lump of camphor
in distilled water and leaving it there for several days. Mr. W. H.
Walmsley, anexpert preparer of microscopical slides, says that he
has had a specimen of Draparnaldia in camphor water for twenty
years, and that it is now as beautifully green as when first mounted,
and that the chlorophyll, its green coloring matter, seems to be un-
changed. When he desires to mount an Alga or a Desmid, he places
it ina small quantity of camphor water to which a few drops of glyc-
erine have been added. At first the plant will become lemon color,
but after a few hours the original green returns in all its vividness,
and then he at once mounts the plant in some of the fluid. }

CARBOLIC ACID WATER, made by adding afew drops of the acid
to a phial of water, is recommended by the Rev. Mr. Wolle, but he
says that although this will preserve them for months or even years
without deterioration, it may allow the coloring matter, the chlor-
ophyll, to fade; this however in the case of the Desmids is of little
importance.

A SOLUTION OF CHLORAL HYDRATE, in the proportion of five
grains of the salt to one ounce of water, answers well for some
specimens. Like camphor water it has the merit of being easily
made and easily used.

A SOLUTION OF COPPER made after the following receipt is admir-
able for some of the Algze, preserving the color and the form entirely
unchanged, while on others it will not act so favorably.

INTRODUCTION, 21

: 50 grammes;
: : 50 grammes;
- 0.5 grammes;
- 2 grammes;
- - 2 grammes.

Camphor water, - - -
Distilled water, - - - -
Glacial acetic acid, - - -
Crystallized chloride of copper, - -
Crystallized nitrate of copper, - -

Dissolve and filter.

When mounting with this copper solution the cell should be
made and the cover cemented down with shellac. With almost any
other cement failure is pretty certain, as the cement will surely
run under and ruin the preparation. After the shellac is hard, it isa
good plan to add some of Brown’s rubber cement around the cover.
This is entirely transparent and will make the mount more secure,
and-at the same time add something to the beauty of the finish.

TRENTON, N. J., 1892.

Powe. fF

Key to the Classes and the Genera of the

Fresh-Water Alge.

KEY TO THE CLASSES AND THE GENERA OF . THE
FRESH WATER ALG.

CLASSES OF THE ALG.
§ Rosy red, blood-red, reddish-brown, purple or blackish; many
Se NE a ee Vw gel tN. ok aA) ig Aas
§ Chlorophyll-green, sometimes becoming crimson, purplish, flesh-
color or yellow-brown; 1, 2 or many celled; often nucleated,

CLASS IL.
§ Never chlorophyll-green; colorless or variously colored; 1 or many
celled; in jelly when out of the water . ° ..'. 39>. CLASS 111:

KEY TO THE GENERA OF THE ALG.

CLASS I.

@ Olive, brown or grey, black with age; filamentous, often hollow,
bristle-like, rigid (A).
“ Violet, violet-purple or bluish-green; filaments articulate, branched
or not (E).
“{ Purple; tufts loose; filaments r in. long, not branched (D).
“ Purplish, smooth, forming a firmly attached coating to stones,
flildebrantia, 7
{ Brownish red, vermillion, or greenish with red centre; cells 4-8,
free or in a short lived cluster . . . . . Chlamydococcus, 38
{ Blood red, cells large, tegument thick, lamellose, stem ringed,
Urococcus, 66
A. Filaments nodose, tufted; fertile filaments hollow, with internal
axillary thread; in rapid water (B). a
A. Filaments transversely banded or annularly constricted; with in-
ternal central axis (C).

) 3

26

GENERA OF ALG&.,

. Axillary thread a single series of cells with transverse threads at

regular intervals .. . oS Sin ete a a aE Se
Axillary thread of cohering Rlamente: ie many whorls of mon-
iliform branchlets So8 5 ENT aR Gin ARENA, ae

. Simple or branched, slinnery: cells in a ieee layer, membrane

thick, colorless . . Os ear mee ts” a

. Branched; main stem often wane an extemal parallel series of

cells; branches moniliform, clustered . . Satrachospermum, 4

. Branched; main stem without external parallel series of cells;

branches not moniliform (F).
Filaments articulate, villose, branchlets dichotomous . TZhorea, 5
Filaments articulate; branches not whorled; plant steel blue or
PUP DUST Ma et OF Fag Cs ae
Filaments articulate; brahoben gree: anfeaninn: plant olive-green,
| Compsopogon, 8

CLASS II.

§ Multicellular or apparently so (A).
§ Unicellular, the cells often clustered or forming a colony (F).

A,
A.

B.
B.

o:

aoimmoo

QO

Chlorophyll diffused, not in patterns (B).

Chlorophyll in spiral bands, axillary lamine, or twin, stellate
nuclei (f).

Filamentous (C).

Not filamentous; articulate, prostrate, or net-like, often membra-
nous, sometimes parasitic (M).

Basal cell lobately divided, or with a terminal disk attaching the
young plant (D).

. Basal cell not lobate nor disciform (E).
. Not branched; terminal cell sometimes setiform, C@dogonium, 10
. Not branched; no setz; strongly contracted at intervals,

Schizomerts, 24a

. Branched; with long terminal sete bulbous at base, Bulbochete, 11
. Branched; no setz; cells long, cylindrical . . . Sctadium, 46
. With branches (G).

. Without branches, but sometimes with lateral processes (L).

Plants filamentous (N).

Plants not filamentous, sometimes curved or spiral, without root-
lets (T).

. Plants globose, small, on moist earth, with colorless rootlets (O).
. Filaments erect (H).
. Filaments prostrate or creeping, branched or not (*).

s

GENERA OF ALG&. 27

* Without dorsal spine;cell walls thick . . . . . Gongrosira, 21
power amee Spe 4 66 Ss , -» Aphanochele, 20
Pe teereea in firm jelly 2 Ce hetophora, 3
H. Not in a firm jelly (I).
I. Filaments dichotomously or trichotomously branched,
Microthamnion, 19
I. Filaments not dichotomously branched (J).
J. Branches in lateral clusters; cells of main stem with a transverse,
central chlorophyll band .... . . . WDraparnaldia, 16
J. Branches not in lateral clusters (K).
K. Cell membrane usually thick, cells longer than broad; ultimate
branches, much thinner than the primary,
Cladophora, 23, or Pithophora, 24
K. Cell membrane very thin and hyaline; stem and branches barely
separably in size and appearance Cg ee MACON, 47
K. Cell membrane thin; branches radiating, umbel-like, one-celled,
Sciadium, 46
L. Distinctly many celled (P).
L. Articulate (apparently multicellular) (Q).

oe

P:

Q.

. Articulate, branched, ee a little mass or a subdisciform

layer et Bits oa OO a Coleachatle:¢

. Articulate, mr Gateate or OS a spiné on the back,
Aphanochete, 20
. Expanded, leaf-like, smooth, formed of angular cells; always ad-
herent ieee ge ea Ey aio. NS

Membranaceous, vaBnlar: or ‘periutar. fixed only when young,

Enteromorpha, 15
. Forming a green net, visible to the naked eye, Mydrodictyon, 41
. Forming a colony, plane; discoid or stellate, often perforated;
cellspolygonal. .. . see oie Pasir ame, “40
. Filaments tufted, long, apiietinees ‘branched: . . Vaucherta, 30

. Rootlets much divided, descending from the cell base into the

earth Up lgtan OA es OPAL SE
Cells long; ehlorophy!l eaploaine hire: regularly placed vacuoles,
. Spheroplea, 12

Cells long, filaments somewhat geniculate, without vacuoles (¢).
Cells short, cylindrical or oblong; without vacuoles; filaments not
contracted; attached when young. . . . Cylindrocapsa, 13

Cells short, broader than long, filaments contracted irregularly,
Schizomerts, 24a

Filaments simple, not laterally united, (R).

28
Q.

GENERA OF ALG,

Filaments 2 or more laterally united, or in flat narrow bands,
Schizogonium, 26

R. With one row of cells, (S).
S. Without lateral processes (except Ulothrix rivularts), strictly un-

branched io sce. les 4. Chars ee onsera: 27

S. With short, irregular, ioteral processes, 1-3 or more celled,

és
y

Rhizoclonium, 29
Parasitic, z. ¢. penetrating the membrane of the host (g).
Not parasitic (*).

* Cells united or clustered in families (U).
* Cells scattered, independent or irregularly clustered (Z).

Meats diddd

re

<I

NN

. Colonies motile, each cell with 2 cilia (V).

. Colonies often free but not spontaneously motile, without cilia (¢).
. Colony (cenobium) spherical or circular (W).

. Colony flat, cells 4-16, angles rounded, in a colorless sheath,

Gonium, 36~

. No gelatinous coating; cells many on ahollow globe Volvox, 32
. With gelatinous coating (X).

. Colony ovate or spherical (Y).

. Colony of 8 cells at equal distances around a circle,

Stephanosphera, 37

. Cells 16-32, globose, at regular intervals on a colorless sphere,

Eudorina, 33

. Cells 8-16-32-64, globose, crowded, often angular from pressure,

‘Pandorina, 34

. Cells free-swimming (a).
. Cells attached to aerial or to submerged objects (4).

Ovate, granular, ina ie obtuse sheath; contractile vesicle
PCRRIE iiss . . . . Chlamydomonas, 39

. Cylindrical, srratwik or Corea (ods sometimes spinous,

Ophiocytium, 47

. Spherical, 3-15in diameter ... . . . . Protococcus, 49
Spherical, too-150 in diameter . . . . Lremosphera, 65
. Compressed, 3-4-8 angled, angles often ceisced or bifid,

Polyedrium, 50

. Aquatic; form variable, cells not spinous, usually stipitate,

Characium, 48
Aquatic; form variable, cells often with a dorsal spine,
Aphanochete, 20

. Aerial; cells circular, flat, numerous, becoming red by exposure,

Protococcus, 49

GENERA OF ALG, 29

. Aerial, on moist objects; gelatinous, cells globose or angular, be-

Comune 607 7 . . . . Porphyridium, 57

. Family in jelly mass, hatte Beth. irregular, tubular, clustered,

branched, etc. (2).

c. Family globose (¢).

bay

Be See

Maly ©

. Family plane, discoid or stellate, often perforated; cells polygonal,

Pediastrum, 40
Family cubical, cells 4-38-16, rhomboidal . . . Staurogenia, 44
Family of laterally united, often spinous or crescentic cells (e).
Family of cylindrical cells (/).

. Cells in a single stratum; coenobium hollow . . Celastrum, 42
. Cells 4-8—-16-32, ii dagger apices sinuate or bifid; coenobium
por ee, ree Ne Ee OSI: 43
. Cells 2-4-8, wicbeee or Shiocie: gy Hae Spee ie COONS Ss, GO
. Cells cylindrical to ovate, ends often spinous . Scenedesmus, 45
e. Cells not spinous, fusiform, am straight or variously curv-
ed, single or united Ate . . . . LRhaphidium, 62
. Upper cells spreading, contracted at bake Ce OU ean, 46
. Cells globose or pear-shaped (A).
. Neck not cylindrical, aperture witha lid . . . Chytridium, 68
Cmrece Cyclical, Clonpated . 2 eS Olpidium, 66

HPD WwW woe NW

Z.

Cells connected by fine filaments (*).
Cells not connected by filaments (7).
Filament attached to the convex side of the cells,
Dimorphococcus, 63
Filament attached to the concave side of the cells,
_ Dictyospherium, 51

. Families free-swimming (not attached), (2).

Families not free-swimming (attached), (/).

. Cells oblong, sree 2-4-8-16; tegument oval or reniform;

Wari oS . . . . LMephrocytium, 61

. Cells oval, small, in grape- ike chastepe: tegument thin, diffluent,

Botrycoccus, 59

. Cells globose, large, cell walls firm, border hyaline; chlorophyll

sometimes radiate . . . ob ec te eremosprera, 05

. Cells fusiform, crescentic or deraigh’: cylindrical, ends cuspidate or

acuminate, tegument thin... 01°... . Rhaphidium, 62
Cells globose, elliptical or elongate (w).

m, Cells red, large; tegument thick, concentrically lamellate, stem

ringed <5 oes era, si Urococcus, 66

m. Cells green; tegument not lamellate ‘

30 i GENERA OF ALG&.

nm. Thallus soon diffluent into shapeless mucus,
Tetraspora, 54, or Palmella, 56
m. Thallus with a definite form (¢).
o. Cylindrical or cumpressed, branched, 2-12 inches long; one pole
of cells colorless . . . «fp hog Ae eS, CS
o. Cylindrical, sometimes septate, ‘attached at one end and spreading,
Palmodactylon, 53

Conjugation ladder-like (zw).

Conjugation lateral (z).

Conjugation geniculate (w).

Aiacdieaniamcr absent, spore formed spontaneously in the cell,
Gonatonema, 78

o. Pear-shaped, fixed by the stem-like base . . . . Afiocystis, 76
p. Chlorophyll in spiral bands (¢).

p. Chlorophyll in two, many-rayed bodies in each cell (7).

p. Chlorophyll in axile plates (¢).

g. Conjugation geniculate. Gulf States . . . . Strogonium, 71
g. Conjugation ladder-like ... oe ie et RE 20
yr. Conjugation ladder-like or lateral (5).

s., Spore in one of the cells) 3.0. 0% te AS ee oe a
s. Spore in the connective between the celle . . . Lygogonium, 73
f.

Z.

Z,

Z.

uw. Spore in the connective between the cells,
Mougeotia,74, or Mesocarpus, 75

uw. Sporesinoneofthecells .... .. . . Plagiospermum, 77
v. Spore lateral, at the point of twocells . . . WPleurocarpus, 76
w. Spore formed at point of conjugation . . . Craterospermum, 80

w. Spore between the cells, quadrangular in front view,
Staurospermum, 79

CLASS III.

§ Multicellular or apparently so, filamentous (A).

§ Unicellular, the cells sometimes clustered or in families (V).

A. With hair-like points (B).

A. Without ‘“ AG:

B. Branched (but spuriously so); in smalltufts . . Calothrix, 81

B. Not branched; not in jelly mass; heterocysts yellow, at the base
of the filaments; free orin smallmats . . . Mastigonema, 82

. Not branched; in more or less firm mucilage or jelly (4).

Branched; in a sheath or jelly mass (E).

Branched; not in jelly.

Not branched (D).

aaaw

woo

GENERA OF ALG&, 31

. In a sheath or a jelly mass (K).
. Not sheathed nor in jelly (P).
. Branched at almost 7 iad to the stem; cells i ina single se-

ol ee aes . . . . Hapalosiphon, 92

E. Branched ieregulagty : or with bats bvanches (F).

=

mmo si

Cells in single series in young plants, several series when older,
Strosiphon, 91
Cells in a single series only (G).

. Sheath broad, striate, hyaline, wing-like . . . Petalonema, 90
. Sheath not wing-like (H).

. Sheaths distinct, not agglutinated to one another (1).

. Sheaths agglutinated in erect, wick-like bundles,

Symphyosiphon, 87

I. Heterocysts present (J).

I.

af not present; sheath with a single bluish filament,
Plectonema, 89

J. Heterocysts disconnected from the twin branches, Scytonema, 86

J. Heterocysts near the usually single branches . . Tolyfothrix, 88
K. In a sheath; filaments moniliform, curved . . . . Wostoc, 93
K. In a sheath; filaments not moniliform (Q).

K. In mucilage or jelly mass (L).

L. Jelly mass spherical; filaments transversely plicate, radiate,

° SR ee err

Om

Gleotrichia 84
Jelly mass hemispherical, filaments radiate . . . Rivularia, 85
Jelly mass a stratum or indefinite (M).
Filaments erect, attached at base, jelly stratum flat, often

MCE RRO As a art cn ant ok tS ee
Filaments not attached at base, mal ‘sodiliforn heterocysts ter-
minal, single. 5... Pero er uty Coen dpcriaa: 98
Filaments not attached, Sol aionittlorn, colorless, heterocysts
SOG cy Sh ei YC OROEAPTS, O°

. Filaments inoniliform, cells globose o or elliptical (N).

“a & cells compressed disciform (O).

. Heterocysts intercalated in the filaments,

Anabena, 94, or Spherozyga, 95

. Heterocysts intercalated at regular intervals, yellow,

Nodularia, 97

. Bluish, bluish-green, blackish (T).
. Whitish or silvery; in sulphur waters. . . . . Beggiatoa, 105
. Two or more filaments in each sheath . . . Microcoleus, 103

Q.

One filament only in each sheath (R).

Daw &

5 Pe

ar)

KK

SS we

Hee 22 2 2460 Gan

GENERA OF ALGA.,

. Parasitic; sheaths thin; cells short, tubular . Chamesiphon, 100
. Not parasitic (S).

Agglutinated in erect, wick-like clusters, articulate, base prostrate,
Symploca, 102

Not agglutinated; exceptionally appearing branched; often form-
ingastratum .. . oe) ta pt) ROME: “ROX

. Filaments parallel in dense clusters: Gee, -swimming,

Aphanizomenon, 96

. Filaments short, heterocysts at their base; not free- -swimming, >

Mastigonema, 82
Filaments slowly motile . . . . . . . . . Oscillaria, 104
Filaments not motile (U).
Filaments very slender, articulations more or less indistinct,
Leptothrix, 106
Filaments cruciformly branched . .. . . Asterothrix, 106a

Free-swimming, (¢. e. not adherent), (W).

. Not free-smimming (X).

Cells globose, or oblong when dividing, in a single, quadrate

layer, bluish-green . . . . . . Merismopedia, 112
. Cells globose, sometimes in a tial colony, brownish or red,
sometimes greenish . .. . . . . « Chlamydococcus, 38
Cells wedge-shaped, in radiating ities . Gomphospheria 115

. Cells filamentous or ring-like, spirally twisted, usually motile,

Spirillum, 107

. Cells filiform, very minute, spirally twisted . , Spirulina, 108

Sheath present, gelatinous or jelly-like, often colorless (Y).
Sheath none; cells spherical or angular by pressure, solitary or in
small families Ronee tur re OE Te a

. Aquatic (a).

On moist timbers and earth; cells small, in globose bodies in a
thin membrane. . Le gon eet OLY abe EE

. Sheaths thin, not confluent: calle sabhlar: short, parasitic,

Chamesiphon, 100

. Sheaths confluent, in a mucous stratum, or elongation or membra-

nous (0).

\
. Sheaths bladder-like, colorless; cells cylindric, ends rounded,

Gleothece, 109
Sheaths confluent (c).

. Sheaths membranous (/).

Cells spherical or nearly so (@).
Cells not spherical (e).

GENERA OF ALGA, 33

. Tegument mucous, cells spherical or elongated, one pole color-

less, notin families . . . Re ee 50 ia ee
. Tegument mucous, with small eetucd families of innumerable
eee. ieee ai ee a ee iy, OE, EF
. Tegument soft, thick SOK aap eee eat id PS PE 120
. Tegument a mucous stratum, jactaiaiuie groups of two cells, these
surrounded by another tegument. . . . . Gleocapsa, 119
. Tegument a mucous stratum; thallus spherical, hollow, cells many,
small, onthe surface .. . . 4 1... -Calospherium, 113

. Tegument confluent, firm; cells longer than broad,

Aphanothece, 110
. Tegument inconspicuous; cells elongate, cylindrical,

Synechococcus, 111
. Tegument soon perforate, breaking into lobed forms; cells very
small embedded «s+ 52... Sei. Y Clathrocystis, 118
. Cells globose, united in families, ‘hastened grape-like,

Polycystis, 118
. Irregularly branched, often closely interwoven; stems and pri-
mary branches:of the same thickness; often aerial, Chrvolepus, 22
. Cruciformly branched, ends acute; filaments articulate or not,
Asterothrix, 106a
. Somewhat dichotomously branched, apices rounded; floating and
yellow, gr not yellow and coating wet rocks . . Calothrix, 81
. Filaments erect, laterally adherent, basally attached, forming layers
on flat surfaces Pampa fe: kes
. Filaments distinctly sheathed at hase. sheaths broad, often sac-
cate, transversely plicate; heterocysts basal . . Gleotrichia, 84
. Filaments agglutinated by mucilage, and forming hemispherical or
PUMNeTY POTMIS ee ee ee OIA SS

Pai Li.

Key to the Species of the Fresh-Water

Alge.

KEY TO THE SPECIES OF THE FRESH WATER ALG.

I. LEMANEA.,

A. Filaments straight, 4-5 in. long, . . . . . . . fluviatilis, 52
A. i arcuately curved (a).
@, 1-2 in. long, olive green, black withage.. . . . . torulosa 51
a. 5 in. long, violet in mass; regularly constricted . . catenata, 52

2. TUOMEYA.

A. Much and irregularly branched; tufts 1-2 in. long . fluviatilis, 53
Me TaMONe a ee Oe grande Rg

3. BANGIA.

Filaments about 1 in. long; in lax purple tufts . atro-purpurea, 55
4. BATRACHOSPERMUM.

~ A. Branches sometimes setigerous, internodes naked or nearly so;

gelatinous. Variable .. . . . moniliforme, 56
A. Branches not setigerous, whorls inperiecdy developed, the branch-
lets often impacted; color bluish green . . . . . vagum, 57

5. THOREA.

Much branched, ramuli horizontal, long and short alternating,
ramosissima, 58

6. CHANTRANSIA,

A. Tufts 1 in. long; filaments with many straight branches; fertile
DTAnCHGs Very Sacre. so eh ES ee eerogpora, - 5a
A. Tufts 1-6 mm. long (a).
a, Parasitic on other plants (3).
a, Not parasitic (c).
6. Fresh water; bright violet, 2 mm. long; branches erect, ends obtuse,
violacea, 59

> Ses SPECIES OF ALGA,

6. Marine; 1-4 mm. long in close fringe; branches rarely opposite,

often Haity.. oss. oe Sa a,

c. Terminal cells cuspidate or ; viliterses . . . . ermannit, 60

c a4 iM TORNGER |e WE ee a eee ee
; 7. HILDEBRANTIA.

a. Fresh water; cells red; on river stones . . . . . rivularis, 61
a. Marine; cells spherical J hig eos POR Oey nce eee en ae
8. COMPSOPOGON,

One species es eS Ea ee Se
9. COLEOCHATE.

A. Filaments irregularly disposed, variable in form . trregularis, 65

A. ¢ radiating (a).

a, Filaments not laterally adhering, forming small disks . soluta, 64
a. . adhering side to side, forming a disk (6).

6, Disk irregularly orbicular; cells subquadrangular . . scutata, 64
6. “ exactly orbicular, thin, flat, . . . . . . orbicularis, 64
6. “ orbicular, upper surface rounded, about 2 mm. high,

pulvinata, 64
10. CEDOGONIUM.

It is only possible to identify the sixty-three species of this genus
when the plants are in fruit, the forms being arranged in groups ac-
cording to some characteristic or peculiarity of the odspore (the seed
or spore), and of the odgonium (the sac containing the odspore). It
is therefore scarcely possible to devise an artificial key.

§ Male and female organs on the same plant (A).
§ Male and female organs on different plants (B).
§ Male organs of fructification not known (C),
. Odspores globose or nearly so (D).

«elliptical or ovate (2).
Males short (dwarf), 1-celled (2).
Males short (dwarf), 2—many-celled (J).
Males filamentous, many-celled plants (gg).
Odspores globose or nearly so ( ff).

‘ elliptical or ovoid (ss).
. Odgonia globose or nearly so (a).

‘¢ elliptical or ovoid (2).
ee opening by a pore (0).

““ ie ee 3 lid (/).

. Pore median; veg. cells 4-6 times as long as wide . cryptoporum, 70

fT Sere rer

re RHP XN RAHA DO &

SREMXENSHSNRNKRNHBDBS SREYYYRHKPSDDWMS

. Odgonia without vertical constrictions (/).
. Odspore globose or nearly so (m).

“6 subellipsoid (a).

. Diameter veg. cells 15-174, 4 times constricted . undulatum,
i" «28-384, not constricted . . cataractum,

. «from 9-15 44 (72).
. Odspore depressed-globose ...-. .. . . . decipiens,
xt exactly globose . . . prig oo LN resehougt,
Dwarf males adhering to all parts of the female . mudltispora,
ss “ onornearthe odgonia . . . . . cyathigerum,

. Odspore membrane smooth (g).

‘6 é beset with bristles (cc).

. Odspores globose or nearly so (7).

m ellipsoid or ovate (zw).

: USecns opening by a lid (s).

“ ‘“¢ a pore (?).
) Terminal cen Toupge 26). eee ek oe Beene,
apie miate. © 345<. . . . macrandrium,

Pore in the middle or a little above i:
““ above the middle (z).

. Veg. cells 4.5-6 times aslong as broad... . flavescens,

“ “ 2-4 ZT: COE ee “6 ““ PONS See Braunit,

SPECIES OF ALG&. 39
. Pore above the middle (c).
Odspore not quite filling the odgonium (2).
Odspore entirely filling the odgonium (e).
. Veg. cells 3-5 times aslong as wide... . . . obsoletum, 71
- ee RTA on ee oe . . . . plustospermum, 72
i BAA er a ee . . . . polymorphum, 73
Veg. cells 4-5 timesaslongaswide ..... . . fragile, 71
““ ‘“ 2-4 CO he 6k rT: “ gee Nee . Zig-Zag, 71
. Odspores subglobose, filling the o6gonia . . . autumnale, 73
. Odspores obovate, not entirely filling the odgonia (g).
. Veg. cells 4-6 times aslongas wide... . . ... wernale, 72
Dee COG Soh ts oy i pis + 3 eraspum, 72
Odgonia single, opening by a seagate pore; GAcouce globose not
filling the odgonium : pg MPO iee F2
Odgonia opening by a pore Shave the ‘uaddie ( aN,
Odgonia . PM en) i pot SU i, hs SAT Ph
Veg. cells 3-7 times as long as wide ... . . paludosum, 74
cc < 2-5 é< “ec “ ‘<“ “ ; : f : ; CraSSUM, 74
. Odgonia with 7-12 vertical Gonebrictions . . . platygynum, 75

40 : SPECIES OF ALGZ.

v. Diameter of veg. cells 13-14u¢ . ... . . . pyriforme, 95
v. ef 6 ES OO Oe BOE SE a mee ae
v. $ FE BONE ee ee ee
w. Odgonia opening by a pore (2).

WwW. “é “6 ce Ge lid (aa).

x. Pore above the middle (9).

x: below ‘“‘ odspore with 4 spiral ridges . Huntit, 85
y. Odspore longitudinally costate . . . . . . . Wolleanum, 82
z. Diameter of odgonia 45-504 by 60-754 . . . #£Boriseanum, 81
Z. prac: 3 a 70-8314 by go-1o5fu@iwsi(‘(‘(wsst«Cf:SCCOnCatenatum, 81
Z. va it tl 29-32 by 33-38u . . . . + sexangulare, 82

aa. Odspore longitudinally costate, filling the odgonium,
acrosporum, 83

OA. eK not ef 5 (40).
66. Terminal cell setiform ) oa a a a a eee oe
bb. Jy “not setiform . . . . . . obtruncatum, 84

cc. Odspores ellipsoid odgonia opening ay a pore in the middle,
Lystrix, 87

ce. “i globose (dd).

dd, Odgonia opening by a pore at the middle . echinospermum, 86

ad. 1 SE SS DONS Ce ake ceed.

ee. Spines of odspores conical (//).

Jf. Diameter of veg. cells 2.5—5 times as long as wide . stellatum, 85

Tt. es ae “ 1-2 times as long as wide . Donnellit, 85

Tae " MAUS 6 64 IO OM OS en rr, oe

gg. Odgonia not or scarcely swollen (4%).

eed manifestly swollen (77).

hh, Diameter of odspore 22-52 by 38-624 =. w:C(«wsC‘(“«‘€;:sS«CCaptlaae, 87

ie a ro i: 47-49 by 50-664 . . . . sStagnale, $7

z. Odspores globose or subglobose (7).

ii i ellipsoid or oval (00).

D- i dies opening by a pore (£2).

Th " ‘“ “ lid; odspore globose . . Pringshetmit, ga

kk. Pore in the middle; tuceabbaie of veg. cells and of o6gonia spirally
PUnClate 4.525; . . puncto-striatum, go

kk. Pore in the middle; mena ‘en wiihictake . 6 WAP CSCERS ABO

kk. Pore above the middle (ZZ).

47. Odspore filling or barely filling the o6gonia (mm).

Zi. Odspores not filling the odgonia (nz).

mm. Odspore globose, filling the o6gonium, diameter 25-29 by 24-30)
_ Franklinianum, 89

SPECIES OF ALG,

41

mm. Odspore sub-globose, ais filling the odgonia, diameter 42-soyu

by 46-56 : carbonicum, go
nn. Diameter of odspore aaa I by ieese fie capilliforme, 88
nn. 2 4 4 51-54 by 73-85 pachyandrum, 89
un. Diameter of odspore 42-60 by 42-6op . cardiacum, 90
oo. Diameter of odgonia 40-454 by 80-1004. Boscit, 91
00. . sf 4 63-75 by 105-120 . | Landbaeehe. gi
00. 3 - s 7o-85 4 by 130-160p . rivulare, 92
00. is os = go—1ooft by 130-150 . _ var, major, 92
pp. Diameter of veg. cells less than 164 (99).
pp. és rit “ 16 or more (77).
gg. Diameter of odgonia 17-18 by 20h . adelicatulum, 93
99. i “ «24-28 by 28-35 . montiliforme, 93
99. DEN OF ares MD Sard i Londiense, 94
99. A . “24-25 by 26-28 hexagonum, 94
rr. Diameter of odgonia 36-40 by 44-45) . . fonticola, 93
rT. és . as 61-754 by 68-80p . princeps, 93
ss. Diameter of veg. cells less than 25 (¢t).
SS. 3 woe - 254 or more (wu).
tt, Diameter of odspore 35-36 by 45-48 yu pyriforme, 95
tt. ey fi ee 15-16 by 17-19 longatum, 95
wu. Diameter of odspore 54-654 by 75-103) gigateum, 94
uu. - fs “45-50 by 68-724 grande, 95

Il. BULBOCHATE.

In reference to the sixteen species forming this genus, the remarks
made in connection with @dogonium might be repeated. The spe-
cies can be identified only when in fruit; to make an artificial key is
therefore almost an impossibility.

Replying to a personal inquiry in regard to the division of the
species into moncecious and dicecious groups, with the presence of
dwarf males on or near the odgonia of all the so-called dicecious
forms, Mr. Wolle writes: ‘These male forms are not developed
when they appear; they are supposed to have been formed in dis-
tinct cells known as androsporangia, and when they have developed
and escaped, they float about and then attach themselves on, at or
near the oédgonium, but they are not necessarily a part of the plant
on which they may be seated.”

42 SPECIES OF ALG,

§ Odgonia globose or nearly so (A).

§ ‘¢ ellipsoid or nearly so; odspores longitudinally crenulate-
costate (F).

A. Dwarf males 1 celled, on or near the odgonia, elachistandra, 97

A « “2 celleds¢B).

B. Basal part (stem) of dwarf males, shorter than the spermogonia (C).

B “ mad iT) “c “ “é

longer than the spermogonia;
oOspore warty .. . je 2 ag Coe ee arenes. eee

C. Diameter of veg. cells 204 or ‘ean (D). |
ea Ls eee “ more than 20; odspore granulate,
setigera, 98

D. Odgonia without terminal seta. . . . . . intermedia, 97
D. ‘¢ with terminal seta, or beneath a eat cell (E).
E. Dissepiment supporting odgonia in the middle of cell or. slightly

below ara digg tly TERE: AE
E. Dissepiment ahave ete sniddie ag the eet . . . . polyandra, 98
E. pe below the middie ofl. So rebisonas, a6
F, Moneecious (G).
F. Dicecious (H).
G. Diameter of odgonia 27-354 by 46-564 . . . . mirabilis, 100
G. re sf i 20-25 by 33-364 . . . . . mana, 100
H. Dissepiment of cells supporting odgonia obsolete (1).
H. iti ‘74 “é 73 “cc present (J. )
I, Diameter veg. cells 12-54, length less than diameter, pygma@a, 101
J. Diameter veg. cells 16 or less (K).
i . 2 ‘* more than 16y (L).
K. Veg. cells 1-1.5 times as long as wide . . . . subsimplex, 101
kK ‘c“ << 2-3. 5 ““ “<“ “ “cc ““ repanda, 102
Bes ies Oe ee Si Ss RN etree rhadinospora, 103
L. Veg. cells 2.5-4.5 times as long as wide .. . . émsignis, 101
RD ree eres ee ce ign ey eee ‘san minor, 10%
A ae yj Meera ne ron pne) PouNE Mey ee a Se

12, SPHAZROPLEA.
Cells 8-10-20 times as long as broad, chlorophyllose rings 20-30 in
Carb ey ee a ie
13. CYLINDROCAPSA,

nds of Cells cleat and pearly a see amena, 105
Ends of cells notclear . . . . . .. . 4 +. geminella, 104

SPECIES OF ALG#, 43

14. PRASIOLA.

Tufts 2-6 mm. high and broad, cells 4-6 in diameter, crispa, 106

§

a,
a,

“« 1-3 inches long and broad, cells 6-8 ‘“ «Mexicana, 107

I5. ENTEROMORPHA,

In brackish water (a).
Fronds simple, elongate; cells 3-5-6 angled . . intestinalis, 107
Ny COMPLOsheG, LNDUIAE fo 2 ak a, OPES, TOT

16. DRAPARNALDIA,

A. Every mature joint with 2-4 clusters of branches, Ravenellii, 110
A. Branches less abundant, not at every joint (qa).

a,

a.

Or

Nw Ww & Q MH

RS NS KAKA

Se So

S.

Branches opposite, their stems thick, short, tapering to a point or
ae ras Boa a EOS en a ia aay, | AOS EO
Branches opposite or alternate . . glomerata, 108, plumosa, 109

I7. STIGEOCLONIUM.
In warm or hot water; 1-2 in. long, much branched, apex a bristle,
thermale, 111
Not in water of high temperature (a).

. Branches ending in a hair or bristle (4).

. Branches not ending in a hair or bristle (A).

. Bristle a colorless, apparently hollow prolongation (c).

. Bristle a delicate, filamentous, hair-like extension (¢).

. Cells nearly cylindrical, equal or twice as long as broad,

protensum, 112

. Parasitic, dwarf,2mm.long;in mucus . . . . . radians, 115
. Not parasitic (e).

Diameter of largest cells 20m or less (/).
ws " “« 25-40“ . . . | Mudiusculum, 113

. Diameter of filaments 11-20; basal cells 6-8 times longer than

MG eas Os wae 2 SOCAN UI TEA

. Diameter of filaments 10-16 (4g).
. Branches opposite on cells smaller and more oval than the others,

flagelliferum, 112

. Branch-bearing cells not smaller (A).
. Upper branches clustered, moniliform . . . . fastigiatum, 114

‘ not moniliform (7).

. Two or more inches long, branches mostly opposite,

fasciculare, 114

. Two to ro mm. long, simple to near the end, there branches

Ciistered i a ee gi a oe ioe pare £8

44 SPECIES OF ALG, »

7

Length 4-50 mm.; somewhat branched, branches simple,
tenue, 110
, ‘¢ - 2-3 mm.; branches alternate, ends obtuse, . mnanum, 112
R. «« 12 mm.; branches mostly opposite, ends acute,
| amenum, 113

18. CHATOPHORA.,

Jelly mass globose or nearly so (a).
Jelly mass elongated to 3 inches, margins tattered, forming ragged
Oranches 00 Ses . . . endiviefolia, 117
§ Jelly mass orbicular, small: Hlameuts heir: pointed . Jongipila, 118
a, Branches more or less moniliform; jelly mass 2 mm. diameter,
montilifera, 118

SR LI

a. Branches not moniliform, radiating (0).

6. Jelly mass smooth (c).

b. “ tuberculose, ends of branches rarely hair-like,

tuberculosa, 116

c. Diameter of branchlets 6; 1.5-3 times longer . jpistformis, 116

¢. ey “ branches 7-10; 1-1.5 “ OO i anges a ee
19. MICROTHAMNION.

But one species. io Pe ree

20. APHANOCHAETE.

§ Parasitic (a).

§ Not parasitic (4).

a, Cells globose, a bristle on the back ey iy POP OMS, IO

a. Cells various, elongate, curved, worm-like, sibs iotsae:

vermiculoides, 119

6. Cells globose, or subpyritform, a seta on the back or apex; in

PCB oe a el eee el ee aa

21. GONGROSIRA.

CONG SPECIES ui, Ae ae gee a ere es ee

20. CHROOLEPUS.

a. Cells globose, broadly elliptic or ovate (0).

a. Cells more or less elongate (c).

6. Dull or bright red; diameter 14-224 = wg = ws s=C«wsSCiwssts em brrinum, 123
6.-Ash color when dry; diameter 20-25 . . . . moniliforme, 123
é.

Diameter of cells more than 25-40; branches rather dichotomous,
Lolithus, 122
c; 25 « — less than 25 (a).

SPECIES OF ALG#, 45

. Stratum tawny red, drying greenish; diameter of filaments 9-14,

odoratus, 122

; Stratum orange-red, drying yellow; diameter of filaments 7-9,

lichentcolus, 122

. Stratum red or orange, soft, silky; much branched; diameter of

Re RSS aiitg ae a es ae ee MT US VST

23. CLADOPHORA.

Chlorophyll diffused, not in spirals (a).
¢ disposed to be net-like or in lax spirals (¢).

. Cell membrane smooth (4).

" se plicate-striate; contents of young slightly spiral,
crispata, 126

6, Cells more or less swollen; irregularly branched; variable,
Jracta, 124
6. Cells not noticeably swollen (c).
c. Diameter of branches 28-40 . . . . . . .. oligoclona, 126
é a ¥ abouti5u St . . . &lotowiana, 126
d. Branches united (connate) at base; cells 5-8 times as long as broad,
cantlicularis, 117
d. Branches not connate at base (e).
e. Filaments not radiating from common centre, cells smooth (/).
é. ‘ 5 e cell membrane plicate . flavescens, 128
é. ei radiating from a common centre, much branched,
| agagropila, 124
jf. Diameter of stems 60-100u . . ... . . . glomerata, 127
Fe ss Pe SAO Rae my er Coe LN es eee eae
24. PITHOPHORA.
me Fertile stem Goiethick 9s 3 dagonna, 1136
An OPO OIC a ee a ee aequalis, 13%
Pe “59 thick ART NE ard oh era Fs, ef
24a. SCHIZOMERIS.
COR Sette i ee eg a es eereeing, FEC £,
25. ULOTHRIX.
§ Length of cells equal to width (a).
eo “« “greater than width (e).
Bek «« «less than width (A).
a. Color dark, light or bright green (0).
a. Color yellowish green (@).

46 SPECIES OF ALG&,

4, Filaments dividing longitudinally; mucous; 4 in. long, floating,
Lenormandt, 138

b. Y not dividing longitudinally (c).
¢. Joints often constricted; diameter of cells g-I0ofk . rivularis, 136
c. Joints not constricted; aquatic; variable; diameter of cells 5—soy,
subtilis, 135
Bs 3 * = filaments tortuous, very long,
muralis, 137
Bey é: “ On damp walls, pavements, exposed rocks, etc., (*)
*. Cells 6-7 in diameter; on walls, pavements, etc. . mitens, 137
Ms EOS Mee si cell contents usually at one side; on ex- —
posed TOCKS, ETC Fea PE eee es
d. Cells 12-14 in diameter. . . . @gualis, 134
d, Cells about 7 in diameter; on moist ley or tose . . Varta, 138

e. Green, cell contents usually on one side, hemispherical, flaccida, 137

e. Green, dark, bright or pale; contents diffused (/).

f. Joints often constricted; cells g-1oy indiameter . rivularis, 136

f. ©“ not constricted; filaments attached, 17-25 in diameter,
tenuls, 134

PRE y ’ filaments not attached (g).
g. In brackish water, filaments 1-3 in. long, 1o-30y dia.,
Younganum, 135
g. Infresh water. . fy EE, hae
hk. Filaments dividing lonpitiiinally, 3 4 in. en Aspley:
Lenormandt, 138
h. not dividing (2).
t. Joints often constricted, cells g-1oy in dia.. . . rtvularis, 136
7, not constricted in sterile filaments (7).
j. Filaments roy or more in diameter (£).
y less than roy in diameter (m),
k. In brackish water; filaments 20-30 in dia. . Younganum, 135
Rk. In brackish and in fresh water; filaments 38—soy in dia.,

Spectosa, 135

Rk, In fresh water only or on the ground (2).
7, On shaded ground; flexuous, interwoven. . . . .parietina, 138
7, Aquatic; filaments 1o-t2uin dia. . . . . . . oscillarina, 137
. ¥: 6). Ten 4Op te aes wig Naan: } Ma ley
m. Bright, grass green; filaments ‘eebacien pe long, interwoven,

muralis, 137
m. Yellowish green, mucous; cells shorter than wide . compacta, 136

SPECIES OF ALG&, 47

26. SCHIZOGONIUM.
One species; found on moist cliffs, Colorado . . . . murale, 139

.

' 27 CONFERVA.

§ In brackish water; diameter 12-14) PIRES, var. salina, 141

§ In fresh water (A).

A. Diameter of filament from 3-5 (a).

A “ ie “from 6-124 (4).

A. Peer s from 14-25 (g).

a. Very pale; cells 1%-2-3 times as long aswide . /enerrima, 143

a. 6c 66 ““c 4-9 “cc ce “<c “ ia ‘ glacialiotdes, 143

a. Green; cells 3-4 ee rs ere eo Ge! TROD RIMES Bae

6. Cells before division 7 times aslong as wide . . . affinis 141

b “ “ec “c“ 4-5 ¢é iz “e “cc we (c).

eg te ‘- ‘“‘ less than 4 times as long as wide (e).

c. Not constricted atthe joints . . . ... . . fugacissima, 141

é Slightly “cc “cc (74 66 (Zz).

d. Cells before division about 4 times as longas wide . Funktt, 142

a. “e “ ‘“ <“ 5 “ “ iz 3 a3 ‘73 filaments of if.
regular thickness . . . GG Sopaileet oi a: OMEN OEIE, hae

e. Cells more or less swollen (*)
é. Cells not swollen, joints not constricted (/).

~ sampecer or Riaments 1o-Ta uo aedgarts, 242
* és . 3 7-0... . . . var, Farlowit, 142
jf. Attached; chlorophyll evenly divosed ie COONS Or etnaaaL' Sag
J. Not attached; contentsgranular .:.. . . ° .:. punctalts, age
g. Diameter of filaments 20-254 . . nae eee aE EO
g. - i less than 20) (2).

Ah. Cells more or less swollen, about twice as long as wide, floccosa, 140
Ie “« “ .“ constricted at the joints,

utriculosa 140; fontinalis, 141
28 CHAHTOMORPHA.
Marine, therefore omitted.
29 RHIZOCLONIUM.
§ On moist ground; cells 1.5—-3 times as long as wide,
hteroglyphicum, 144
§ In brackish water (a).
§ In sweet waters (4).
a. Filaments irregularly curved and angled. California, Casparyt, 145
a. Filamentsnot specially curved; diameter 20-304 . . salinum, 145
a. ce 66 e ‘73 “ 33-48 i R major, 146

yy a Yio

R OOD ON

s

Oe

oF SR oe oR RM

SPECIES OF ALG&.
Permanently attached, in rapid streams . . . . . fuitans, 145
. Not permanently attached (c).
Diameter of filaments 13-15.54 . . . . . . . fontinali, 144
“ “ . 25-33" 5 egele Sie Sn aaa ci eae
Af . 4s 36-40 OT vo g oReee

30. VAUCHERIA.

I. KEY TO THE STERILE PLANTS,
In salt or brackish water; mats velvety, feet in extent,
Thuretit, 149

In sweet water or somewhat terrestrial (a).
Apparently terrestrial only (4).

. Filaments dichotomous, branches constricted at the base of the

divisions, often intermediately, . . . . . . . tuberosa, 154

. Filaments not constricted at the branching points (0).

Stratum dense, pellucid below, creeping; terminal branches erect,
clustered, often crooked: 300 5° ot eo Deland, tee

Stratum not pellucid below (c).
Branches not clustered, vague. Thus far found only in California,
hamata, 153

Branches dichotomous or sparingly formed (¢).

. Diameter of filaments rooy or more (e).

# ss 2 less than 1oop (g).
Diameter 100 to 200p (/).
Diameter 1254; tufts dense, dark green . . . . geminata, 151
- roo; tufts loose, expanding in all directions,
aversa, 149
“4 100-200; dirty green or brownish; about limestone

Sg Cog. aie eh aaa adichotoma, 149 —

. Diameter 180-200, often hyaline; drying ash gray . pilus, 153
. In turfy mats; filaments densely intricate; 50-75 4 in diameter,

Serviced, 150

. In dense, intricate tufts; filaments dichotomous, 504 in diameter,

geminata, 151

. In loosely intricate clusters; filaments about 5oy in diameter,

sessilis, 151

. Stratum thin, expanded, filaments about 50m in diameter,

Dillwyntt, 150
a “« densely interwoven, dark green . . “¢errestris, 153

:
:
;
b.

SPECIES OF ALG&, 49
Il. KEY TO THE FRUITING PLANTS OF VAUCHERIA.

Antheridia slightly bent; the opening at top (a).
bs bent like a horn or hook (¢@).
V4 not known (g).

. Odgonia nearly round (4).

«not round; oval, often rather oblique (c).

. Odgonla about roowindiameter .. . . . . dichotoma, 149

* 7 2e8—-t20u.. ie gt et RUIN EAS
. Odgonia 1-6, on one side, mouths aral produced beak-like,

sericea, 150
/ erect, seis not ee not produced beak-like,

aversa, 149

. Antheridia beside or between the subsessile odgonia (e).
. Antheridia terminal, with the odgonia on each side or lower

down (/).

Terrestrial, broadly expanded; antheridia bag-shape or clavate,
Dillwynti, 150

. Aquatic; antheridia short and straight, or elongate and variously

CULVER ee, Sills ol SOSHEEOS BEE

. Terrestrial only; athieeidenti lone. caeved, sGponis on its back,

terrestris, 153

. Not strictly terrestrial; fruit on short lateral branchlets,

geminata, 151
“ 2 a fruit on short segments on the divided
ends of branchlets .. . RAMEE TES

. Branches regularly constricted at tae aud often elsewhere,

rade, 154

. Branches not constricted; filaments 180—200y in diameter,

pilus, 153

31. BOTRYDIUM.

CIE See ar ne ee CY RIIM ATR, EEE

32. VOLVOX.

One S0CCieb es Be ee ok a naar, ee

33. EUDORINA.

Brie SOECIOS re ee ie ee ta eee a. rar, VSR MIRe pS LOO

34. PANDORINA.

SE PUUIOR. ee Oe a a eR oe ys ROPES EOS

5° ; SPECIES OF ALG&,

35. EUGLENA.

The question as to the animal or vegetal character of Euglena has
been debated. The present tendency is to consider it an alga,
although the evidence is rather negative than positive. For the
present purpose however, it seems best to leave it among the Infu-
soria, where the older investigators classed it.

36. GONIUM.
Orie SHecies ie ea as ee
37. STEPHANOSPHARA,
No forms yet found in this country.
38. CHLAMYDOCOCCUS.

a. Cells subglobose, brownish-red, sometimes green; variable,
pluvialis, 164
a. Cells globose, red; at first with a hyaline border; on the snow of
high peaks, €tc: a \ ee lal vee re ea mn ee

39. CHLAMYDOMONAS,

With a red pigment spot (a).
Without “ . reais f 9 9

COD COD

a, Ovate; length twice the width; pigment spot lateral,

pluviusculus, 168
6. Pale, whitish green; oblong-elliptical .°. . . . Ayalina, 168
6. Bright light-green )
c. Ovate oroval . . wa RUE TT a Bi er
é. Spherical or nearly so... i. ou ae ee

40. PEDIASTRUM.

For full descriptions and figures of the species, see Wolle’s “Des-
mids of the United States,” from which the following classification is

compiled.

§ Apices cuspidate, each cell with one cusp or bristle (a).

§ iss ‘Ti e “cc “<< two ““ “ “cc (c).

§ Apices or angles, bidentate; small; cells often 4 . cuspidatum, 154

§ Apices truncate; cells 4 in form of cross, 4-sided; small, /e¢tras, 154

§ Apices concave, undulate (2).

§ Apices bilobed (e). :

a. Cells six, ovate or subfusiform, radiately connected; centre closed,
simplex, 152

a.. Cells six, 5 angled; centre open: «. 2)... 2) ee may A3

a, Cells more than six (4).

6. Outer circle 14, inner 7, centre closed by 1; outer spaces 7,inner 4,
stmplex var., 153
6, Outer circle 12, inner 4, centre open; outer spaces 4,
duodenartus, 153
b. Cie circle 14, inner 7, centre closed by 4; outer spaces 7, inner 4,
stmplex Var., 153
c. Marginal cells 2-lobed, each cuspidate; cells 8-16-128; centre closed, _
Boryanum, 153
d, Perforated by small openings .. . . . . brachylobum, 154
ad. No openings; centre closed; . . . . muticum, angulosum, 153
e. Perforate by small openings, or centre open (/).
e. Not perforate, centre closed (g).
f. Cells 16-32-64 fe ee a Vis! iting POPTRSUMN Se
7 iCeus 6 Centre open-.-. , . . angulosum, var., ¥54
g. Apices converging, space baleen oat Sle. 72) TOPE RIEME, 25%
g. Apices not converging (A).
A. Each apex 2-lobed, sometimes diverging . © hrenbergti, 154
41. HYDRODICTYON,
Wee Wee eR eR ae oO eiecaletum. 169
42. CCLASTRUM.

a, Cells globose, with interstitial openings . . . microporum, 170
a, Cells angular, each with a tubercular process . cambricum, 170
43. SORASTRUM.
pme SOCCER re ea CO pemeloium. 17%

44. STAUROGENIA. .
SUC i a oe a ne ere Bay
45. SCENEDESMUS.
Cells armed with spines (a). .

§
§

ier. aS

SPECIES OF ALG, 51

Cells not armed with spines (e).

. Aquatic (4). :
. On moist sand, Florida; cells 2-4, fusiform,

antennatus, var. rectus, 172

. Cells oblong, cylindrical, ovate or globose (c).
Cells, some at least, spindle-shaped (¢).
opines recurved On Outer Celle i. 3 Sk. eeudatus. 172
Spines straight, single orsometimes two. . . polymorphus, 173
Spines straight, three to five . . . Wa ins, POPARAGIES L954
. Inner cells fusiform, armed, outer Liwate, . . . @imorphus, 173

. Fusiform, oval or globose; spines straight . . jpolymorphus, 173

52 SPECIES OF ALGA,

e. Cells, some at least, fusiform (/),
e. Cells oblong_or ovate, obtuse; 3-5 times as long as wide,

obtusus, 173
f. Cells ina single even row; outer cells lunate . . dimorphus, 173
f. Cells usually all alike, acute, 3-6 timesas long as wide, acutus, 173

46. SCIADIUM.
a, Attached, umbellate; cells usually straight; base contracted into

a short‘stem'). 50-5 . . . arbuscula, 174
a. Floating; a collection of umbels connected by a usually straight
CON og Es ge i EO a ee

47. OPHIOCYTIUM,

§ One or both ends spinous (2).

§ Without spines (c).

a. Both ends spinous (0).

a. One end spinous, one end rounded; cells curved or coiled,
cochleare, 175

6. Cells arched or nearly straight, ends more or less enlarged,
capitatum, 176

6. Cells crescentic, Closterium-like, large . . . . cuspidatum, 76

c. Cells small, curved, often in masses, ends rounded, parvulum, 176
c. Cells long, narrow, repeatedly coiled, ends rounded, cércinatum, 176
48. CHARACIUM,

§ Sessile, no stipe; cells pyriform, apex.somewhat produced,
sessile, 177

§ Not sessile, stipe present but often short (a).

a. Apex rounded or truncate (4).

a. Apex acute (¢).

6. Stipe short, scarcely noticeable, end dilated; cells producing a

short neck . . Wis pCi g a Nar 2 Oat au ct a Oe
. Stipe longer, nouGeun: (6.
c. Apex produced as a thick neck; stipe brownish yellow,
Pringsheimtt, 177
c. Apex always rounded, cells obovate, stipe base not dilated,
Negelit, 178

~

c. Apex rounded, truncate when open; stipe hyaline,
heteromorphum, 178
ad. Producing a short neck; cells ovate ... . . . . acutum, 177
d, No distinct neck; lanceolate or sword-shaped, ends tapering,
ambiguum, 177

hy Ma ee

SD & SRR ROME

g

g

8

SPECIES OF ALG,

49. PROTOCOCCUS,
Aerial forms (a). :

Aquatic (c).

. Cells without gelatinous envelope (4).
. Cells with gelatinous hpiaie. in which they divide; angular from

° $3

pressure =. ; 4 . . angulosa, 181
. Common aeayaueves on freee: bacon: ete. cells yellowish green,
viridis, 181

. On moist old wood; cells dark green; decussately dividing,
dissectus, 181
. On pots, etc., in green-houses; orange, reddish-brown, yellowish
green wits Eh gee”, | PRES EOP

Beset with small Senied or aie (Oe ate ace ates CRC Tee

Smooth, in gelatinous tegument, . . . humicola, 182; gigas, 183
2 not in tegument (¢).
. Cells clustered somewhat grape-like . . . . . botryotdes, 182
. Cells single, membrane thick, oftenlamellate . . Wimmeri, 183
. Cells varying in size,membrane not lamellate . . :nwfusionum, 182
50. POLYEDRIUM.
Angles rounded, not spinous (a)
“bifid or trifid (4).
‘“‘ spinous or greatly elongated (c).
Cells 4 or 5 angled, diameter 35-7ou ..... . gigas, 184
«-4-angled, diameter 8-lof# 3... 0... minimum, 185
“3 angled, diameter 12-15u . . . . . . . = muticum, 185
. Angles bifurcate, sharply tipped . . . . . . dtfurcatum, 184

“« often repeatedly bilobed, hyaline, acute . . enorme, 184
. Centre scarcely body-like, radii thin, much prolonged,

longispinum, 185 -
. Centre distinctly a body; angles spinous . /etragonum, minus, 184
51. DICTYOSPHARIUM.
. Cells ovate or subglobose .. . . . . &hrenbergianum, 186
. Cells reniform, about twice as long as wide . . ~rentiforme, 186
. Cells oval, often centrally constricted . . . . SHitchcockit, 186
52. HYDRURUS.

One Very Vatiaine Srecieger aoe ee So ay FOS EBT
| 53. PALMODACTYLON.

. Family of cylindrical, bladder-like radiating cases; cells in 1 or
more rows . . . . vartum, 189
. Family simple, not Heatched, more : Wismentbus . . Simplex, 189

cylindrica, 190
a, Cells 8-1ojzin diam.; yellowish-green . . . . . lubrica, 191
4. Colorless, or green edged 8). es one eee
4. Green, rather soft and slippery . . . . . . explanata, 191
¢. Dark green, smooth or somewhat warty; cells crowed in 2s or 4s,
bullosa, 190
55. SCHIZOCHLAMYS,
Supposed to bea form of Tetraspora.
56. PALMELLA.
§ Aquatic (a).
§ On wet ground or dripping rocks (4).
8 On wet WObG ho. Se . . Uuveformis, 193, botryotdes, 194
a. Irregularly expanded; cells mpnlite (0.75-1.00/4), crowded,
hyalina, 193
a. Somewhat globose, tuberculate; cells elliptical, 5 by 8, |
Mooreana, 193
'b. Thallus expanded or indefinite . . . mucosa, 192, mintata, 193
. 57. PORPHRYDIUM.
One species; terrestrial 2.) i ee a
58. BOTRYDINA.
One species; terrestrial 640 f CP DU a
59. BOTRYCOCCUS |
One species; aquatic: =.) ese ee, ee | ee
~ } 60. GLOOCYSTIS.
§ Aquatic (a).
§ On wet rocks and walls; cells 3-5 in diameter . . rmpestris, 196
a. Dirty or bright green; families 45-90 indiameter . ampla, 196
Fe eh Oe 5 RI “ families about 35 in diameter,
vesiculosa, 196
a, Brownish-yellow or reddish . .... . . . wrufescens, 196
61. NEPHROCYTIUM.
Families oblong or elliptical, cells reniform . . Agardhianum, 197

64 SPECIES OF ALG,

54. TETRASPORA.
§ Thallus tubular, splitting (qa).
§ Thallus irregularly expanded (0).
§ Thallus membranous, saccate, obovate, sinuate, bullose (c).
a, Cells about ree in diam.; ends tapering to a fine point,

Families subspherical, cells oblong or elliptical . . WNegelit,

197

SPECIES OF ALG, 55

62. RHAPHIDIUM.

a. Cells straight or nearly so, length 15-20 times the diameter,
actculare, 197

ees. " seageieae “« “20-30 or more times the diameter,
contortum, 198

a. Cells decidedly curved; often crescentic or sigmoid (4).

6. Cells sigmoid, single or 2-4 connected . . . .. sigmotdeum, 198

6. Cells more or less crescentic (c).

c. Cells connected back to back, crescentic, sometimes single,

convolutum, 198

c. Cells not connected, long, slender, . . . . . . falcatum, 198
Genie aaa tf short, thick, diameter 5-74 . S#raunii, 198
63. DIMORPHOCOCCUS.

SEMIS ee ars te iyo Geo ee Pa es) CORQEEME,.. QO
64. MISCHOCOCCUS.

See Oe gh ee ere Pc ee dof ertecola, 200
65. EREMOSPHAERA.

MMM NaN Ie rm eel ioe hy Sabla Sie viridis, 200
66. UROCOCCUS,

a. Stem densely ringed, often divided . . . . Hookerianus, 201
a. Stem short, remotely annulated ..... . . émsignis, 201
67. APIOCYSTIS.

RMN ENORIOR ec) fr, Sinner went Gece gi gts. ce: ah RE, 208

68. CHYTRIDIUM.
a. On the odgonia of various ratte cells somewhat urn-shaped,

Witt GO ne se. mW ey a): | QEMMUARATEME, ' 258
a. On various filamentous Alo (2).
b. With a low lid; pale yellow . . ... . . .:. Minus, 203
6. Without a lid; cellsspherical .. .: . . . globosum, 203

69. OLPIDIUM.
§ On the exterior of the host; cells globose; mouth cylindrical,

nearly aslongasthecell . . . . . . . ampullaceum, 203
§ In the interior of the host; oe neck tubular, middle
globosely-dilated. . =... . . . . tntestinum, 203

§ In the interior; perforating neck stenighty not inflated,
entophytum, 204

56 SPECIES OF ALG&.
70. SPIROGYRA.

I. KEY TO THE STERILE PLANTS.

As it is often difficult to determine the number of spiral bands
within a cell of Spirogyra, the following method, originally suggested

“~by “The Botanical Gazette,” will be found exceedingly convenient.

Select a band near the middle of a cell, count those that cross it, add
one to the number, and the result will be the whole number of bands
in the cell.

§ Membrane of ce!ls folded in at the ends (a).
§ ¥ « « not folded in at the ends (/).
a. Chlorophyll bands one only (4).
a “i “two or more (g).
6. Membrane of spore smooth (c).
b, #3 punetate (7),
c. Filaments 28-33 in diameter; cells 3 to ro times as long as wide,
: Grevilleana, 209
&: . 24-30 “ ff cells 3-9 times as long as wide,
guadrata, 208
C. ‘ 18-28u “ a (2).
“ 9-18 ‘<é ‘6 (e). .
d. Cells to—-25 times as long as wide; spiral of 1% to 4 turns,
Spreetana, 208
@d. Cells 6-15 AO ORI Ae 2 oe 0S Gt,
Webert, 208

:

e. Cells 4-15 times as long as wide; spiral of 3-6 turns,
tenuissima, 207
Co EO BB SE OL a Aa ee ee
f. Diameter of filaments 36-40; cells 6-12 times the diameter,
calospora, 209

g. Spirals two (A).

g. Spirals three; cells 30-33 wide, 4—8 times as long as wide,
Hassallit, 210

A, Cells 16-22 in dia., 4-8 times as long as wide, . Hélseana, 209

kh. Cells: 30-3354 0%) 4B SB SO eee

Ah, Cells 36-454 in diameter (2).

#, Cells 4-12 times as long as wide . .. . . . » émsignis, 210

Oo SO re EME A EE | SON aig eae age oo

j. One spiral in each cell (4).

j. Two or more spirals in each cell (¢).

SPECIES OF ALG#,

k. Membrane of spore smooth ().

k. 58: - punctate {s),

Z. Cells less than twice as long as wide (m).
Celis twice or more fo. fg),

m. Diameter 22-254; 1-14 times as long as wide, ._ sudsalsa,
m. ie BRET A I Tato i A eo Der Iaes:
Mm. 33-404; 1-2 rarely 6“ “* MEME FO guinina,
mM. ss 48-754; 1-14% times“ “ “ “ | condensata,

n, Diameter 33 or more (0).

n. a less than 334 (¢).

o. Diameter 33-40; 1-2 rarely 6 times as long as wide, guznina,

0. 30-55 # (2).

p. Cells 3-7 times longer than wide; spiral dentate . Lufetiana,

ee ae a is fusco-atra,

g. Cells 3-5 times as long as wide (7).

g. Cells 2-12 times as long as wide (gg).

ry. Diameter 22 orless . . flavescens, gracilis, 211; communis,

a. i 24 OF MOTE 9 eS Variens, 212; Jurgensiz,

s. Diameter of cells 24-27 4, 6-12 times longer than wide, punctata,

¢, Spirals 2 (w).

zt. ae).

z. em (aa).

t, Pe ape).

t. “6 or more (ff).

u. Diameter of cells 40 or less (z).

u. : «¢ -“ more than gop (w).

v. Cells 2-4 times aslongas wide ..... . . detimina,

Be ers re etry fie e tee GN gS ahs 5 9 | ROI OND

w. Cells 1-2 times aslongas wide ..... . .. subequa,

ee eee eo re Pere i?

x. Cells go-1o0o0y in diameter, joe soiiewhat constricted,
jugalts,

x. Cells 50m or less in diameter (y).

x. Cells more than 50, in diameter (z).

y. Cells 7-11 times as long aswide .... . . . rivularts,

y. “ lessthan 7 timesaslongas wide .. . dubia, adnata,

z. Cells 1-2 timesaslongas wide ..... . . subequa,

Bo eee UR et a pire,

Oa 2S Nitin Se Ue. URC ie ary) RUG Ot genie URAC aye gh S

Be eR a ee eA eh ee a RR

57

212
212
213
215,

220
217
217
218
226
221

58 SPECIES OF ALGA,

aa, Cells more than room in diameter (40).

aa. “ from 72 to 1000p “ © (cc).

aa, ** leas than you me (dd).

bb. Cells 150-156 in diameter (the largest species) . . crassa, 219
bb, ““ t02—-110p “ é Speer has eg ieee Ne 8
cc. Cells go—1004 In diameter’... ae ee Pee
SC OOM x 1-3 times as long as wide witida; 217
Te RNAS aaiR br 8 ‘ * 2-4 RE RE Ie arUNSOnm: mee
dd. Cells 58-65 “ sf OPM et ee
dd SS egg ‘¢ a PEE ES Ue eS ee
ee. Cells.65—734 in diameter > eh ay Se. 2 eee eee
ee. “ 58-65 “ at ‘ . . . orthospira, 218

Jf. Filaments of two dinnuetere: one saa ithe other 80p,
inequalis, 218

Tf, ¢ “ same diameter, 150-1560). FN ere, 280
ff ‘6 io ah ‘< 102-110. . ._~—s Set formis, 219
ef, “ “ek é r1I8—125m@ Fo Samia, 218
Sf. ‘6 “Ke as 54-62u . . . . . mazjuscula, 221
gg. Cells 4-10 times as long as broad, 24-27. diam. . mitrabile, 211

PO ae eae ee ee “ 25-30udiam. . J/ongata, 214

Il.—KEY TO FERTILE FILAMENTS OF SPIROGYRA.

For method of determining the number of bands in the cell, see the
Key to the sterile filaments of Spirogyra, p. 56
§ Cell membrane folded in at the ends (a).

aia not folded in at the ends ().
a. cBro eng band single, rarely double (0).
a. «two or more (A).
6. Membrane of spore smooth (c).
b. " “« “punctate (2g).
c. Spores elliptical or fusiform (dz).
c. “ ovate or oval (e). |
@. Spore 24-30" by 50-58u . «www wtwttstCi«w#stSsChMUISSIMA, 207
d. © 30-36 in dia:, twice as tong =... ok. . . efiefa, 207
d. “ 27-32in dia., 2-4 timesaslong . . . . . guadrata, 208
¢. Spore-bearing cells fated (/).
es ten 28 “« slightly dilated; spore 26-30, in dia.,
Weberi, 208

fF. Spores 36m in diam., 2-3 times as long as wide . Spreetana, 208
Sf. “ 30-36 in tok. 2-254 Ms ig APO ane, 200

SN Nw wD. DDS

ee ee

sess

SPECIES OF ALG. 59

. Mature spores yellow or orange, 40-42 in dia. 2-3 times longer,
calospora, 209
: Seey Meshing cells not swollen, spores twice as long as wide,
Flantzschit, 211
. Spore-bearing cells swollen (7).
Mature spore yellow, 42-48u long . .. . . . Hassallit, 210
i: “ brown, elliptic, 284in diameter . . . imsignis, 210
One chlorophyll band in each cell (£).
Pear more Sc Fy a Fe fd).
. Membrane of spore smooth (2).
Hf so Sct ate: (ay.
Mature spore yellow (7).
" “not yellow (/).
. Spore cell slightly swollen on one side, spore oval,. twice as
one aswide =. |. Se AL gee ON gk eg PRIN EE
. Spore cell not swollen ta
. Spore cell swollen (o).
. Filaments 20-224in diameter . . . . . . . communis, 213
+ 25-30) “ ae DR Ble gta uae tre ROE, Ve
. Filaments 24-26y in Hamers hee ak tit Me Ene da es Sy Meek
- 40-434 “ e: Se cade RAINE 2 ak
Spore-bearing cell decidedly bwolien ie
: “ not or slightly swollen (7).
" “ *¢ swollen on one side only . . . varians, 212
Filaments 25 2) Camicter ea nial, 282
s 13-20 “ és Sl DESCERS.” 25%
. Filaments more than 30pm in diantcter 4).
“ 30 or less in diameter (Z).
. Diameter of filaments 33-40; spores polymorphous, gwinina, 213
‘s yy 3 40-554; spores polymorphous,
fusco-atra, 215
- 2 48-75 4; spores broadly elliptic,

condensatla, 215

. Diameter of filaments 25-304; spore twice as long as wide,

; _ longata, 214
‘6 46 “ 22-254; spore slightly longer than wide,
subsalsa, 212

. Mature spore yellow, spore cell much inflated, . . pwunctata, 215
. Spirals 2 (w).

ee
Lee).

60 SPECIES OF ALG.

Sey eines C8 &

v. ‘ 6or more (7).

w. Spore-bearing cells inflated, spore elliptic or ovate, elongata, 221
ee eR . “not or only slightly swollen (x).

x. Filaments 32-40 indiam. . . .. ... +: . . @ecimina, 216
m8 <i BE SORE i Po Sa ey a Nae eg ese ae eg ee
% ef 55-Gou . . . subequa, 220
y. Mature spores yellow, oval, \ lnauer than wide . wmneglecta, 216
J. 350 “not yellow (2).

z. Diameter of filaments go-1oof#; spore oval . . . jugalis, 219
Z. * . 40-65 4 (aa).

z. ie « e 32-36 (dz).

aa, Spore orbicular, flattened . . . .. . . . orthospira 218
aa. Spore not flattened (4).

bb. Spore spherical or broadly ovate . .... . subequa, 217
6b. Spore not elliptical or ovate (cc).

cc. Spore oval-elliptical or subcylindrical . . . dubia, adnata, 220

cc. Spore oval or subglobose, spore cells 2-4 times longer than wide,
majuscula, 22%
dd. Sterile cells 7-11, fertile cells about 4, times as long as wide,
rivularis, 220
ee. Spore-bearing cells much inflated, spore oval, 80y long,
fluviatilis, 216

RO * “ slightly or not inflated ( //).
Jf. Spore flattend, orbicular . . .. . . . .° orthospira, 218
Sf. Spore not fattened ( gg).
gg. Diameter of filaments 150-156" . . . . . . . crassa, 219
gg. 6 x4 LO2—TIOf ek yk ehefermes, 2ag
gg. ig ¥ 4 QOHTOO PE 2 oN Ee ane ee a tae
gg. * v4 72-784 (hh).
hh. Chlorophyll bands making 1-4 turnsin eachcell . wmtida, 217
hh. * “¢ “ 11% spore 50m wide,

parvispora, 221
zt. Spores flattened, orbicular, membrane smooth. . orthospira, 218
az. Spores “ e punctate or porose,

_ bellis, 217
jj. Filaments of two widths, one 125 p, the other 80h, inegualis, 218

i]. 4 of equal width seh

kk, Diameter 150-156" . . ssp ele cig: oe Ske ne Gacw et cas i err
RR. . SEO 1 OG Me SH a 4 2 er
Rk. - LOZ—EXOM ae Oe a 6 rr

Rk, w SAORI ee i, ee

SPECIES OF ALG. 61
71. SIROGONIUM.

oC ee rw aetna og at. My See

72. ZYGNEMA.

§, Color soon pecenye:' dark purple; filaments 20-25 4 in diam.,
Sieasein 224

§ Color green, or when in fruit yellowish or brownish (a).

a. Filaments with gelatinous sheath; cells 25 wide, anomalum, 224

a. eA nt or “ cells 40-444 wide, crassum, 224

a. : without sheath (4).

6. Spore membrane smooth (c).

hes is “punctate or granulate (¢).

c. Diameter.of filaments 20-224 . . . . . .°. Letospermum, 222

oft: “ ba . 2O—30fF ot wre: insigne, 223

a. Diameter of filaments 10-36, very Variable eo Shelia, 244

a, 1% if st BER OU ool ak rea ke: ote CMT VER
73. ZYGOGONIUM.

§ Diameter of filaments 20, or less (a).

§ i . cs more than 204 (c).

a. Diameter of filaments 15-184. . . . . . . . Agardhii, 226

a. i a is oe (0). |

pe epore spherical.) 5 0. 3 -ey “po decussabum, 262

b “« compressed siipentas ewiee as Hong aswide . Ralfsit 227

ec. Cells slightly constricted at the joints; spore punctate,

pectinatum, 225
c. not constricted (@).
a, Filaments 30-33in diameter . . . .. . . . @quale, 226
d, a 22-24u “ ie PES gs Ao Ever ah kg gc aa a

74. MOUGEOTIA,

§ Filaments 20-25 4.in diameter (a).

§ less than 20m in diameter (0).

a, Spore spherical, diameter about g4ou . . . . = spharocarpa, 227
OS “ | . Oi ARE ke ee OR ee
J. Filaments 15-18 in diameter . . . . . . Minnesotensis, 228
b. “ 10-14) te 46 (c).

¢. Spore spherical, 25-304 in diameter... . . delicatula, 228
c. “ oval, radiately corrugated, yellowish-brown glyptosperma, 229
* SS Saha “coarsely granular, dark brown . . . verrucosus, 229

62 SPECIES OF ALG,

75. MESOCARPUS.
; Diameter of filament 504; sporesmooth . . . . . ¢rassa, 230

: e " ‘ 18 or less (a).

§ 4 a 20 to 324 (Cc).

a. Spore membrane punctate; filaments 9-154 diam. nummuloides, 231%
’ EaG . smooth (4).

6, Filaments 8-rofin diameter . . . .. . . . parvulus, 230
b. i 10-18 “ . og RECUR ORS, S2t
c. Spore membrane punctate; Biadedee me fin diam, robustus, 231
“eee: a smooth (2).

d. With short branchlets from the middle of acell . vradicans, 231
@d, Without branchlets (e).

e. Diameter of spores and filaments about equal . ._ scalaris, 230
é 4 « «twice that of the filaments . macrospora, 230

76. PLEUROCARPUS.
§ Diameter of flaments 25-304 . . . . . . . . mtrabilis, 232
§ 5 " . 37-40" . . . . . . « Columbianus, 232
77. PLAGIOSPERMUM.

CHE SPECIES oy 6 es Oe eta een ee

78. GONATONEMA.

(One Species: or i ee ae le

79. STAUROSPERMUM.

§ Diameter of filaments 14-20, becoming bluish, spore smooth,
capucinum, 234

‘i 8-124; spore punctate . . guadratum, 234

A i " 6-8u;spore smooth . . . . wirtde, 234

Cr Se
~
nw
nw
nw

80. CRATEROSPERMUM.

One SHECIER. i. A aoe rec on Je en 235

81. CALOTHRIX.

§ Diameter including sheath 6-84 at base . . . . gracilis, 237
§ “< ‘< “ IO-I 4p (2).
§ ‘é ‘“< “c 15-30) (2).
a. Sheath lamellose, ends colorless, torn into fibres; cells 6—8jzin diam.

Meneghiniana, 238
a. “ not fibrous at ends; brown or black in mass, gypsophila, 237
” aaa ws Ks « “bluish, rarely brownish, Dz//wynit, 237

Oe

we NR RS DO

R RM

SPECIES OF ALGA. 63

. Floating, dichotomously branched, apices slightly bent; diameter

RR ee aha oy i ey ig) kA MCOUR, 236

Attached (c).

Ends rounded, obtuse, fibrous with age, bluish . crustaceum, 239

Ends tapering, or hair-pointed (2).

Forming a stratum (/).

Forming tufts (g). 5%

Branches tapering toa fine hair-point . . . . Horsfordii, 239
on cuspidate at apex or obtuse . . . . Orsiniana, 236

Tufts small, wavering; filaments somewhat curved, clustered, ra-
diating; sheath up tozoy, wide . .. . . . radiosa, 239

. Tufts bright bluish, sometimes brown; sheath widens with age,

Brebissonii, 238
82. MASTIGONEMA.

Filaments rounded or truncate at apex (a).
" tapering to a hair-point (0). °

. Sheath thick, apex truncate, open; diam. 8u . . . fertile, 244

*« in young plants ending in a seta, becoming open and trun-

cate; diam'12u . . haar of ae Te G

. Mature sheath becoming fibrillose at ‘the ends (c).
. Mature sheath not fibrillose or rarely so (@).

c. Filaments 4 in diam.; yellowish or greenish; parasitic,

R

g

sejunctum, 243
Filaments ro-11y in diam.; bluish green; on wet rocks, fisrosa, 244

. Thallus subglobose or fusiform, blackish, firm; filaments bluish,

diam.6-7u4 .. . eh cy iat, (e) SIORC CIMA; 24%

. Not subglobose; filaments dechight. pene or curved, @rugineum, 241

83. ISACTIS.

. Filaments closely compacted, suddenly acuminate . fluviatilis, 244
» Pitaments erect, awl-shaped. 2.) 4.90...) ins 2 c@espitasa, 245

84. GLCOTRICHIA.

Sheath irregularly constricted; variable in size and form, watans, 246
*« close, simple, not inflated nor constracted, subspherical,

plsum, 247

e
85. RIVULARIA.

. Sheaths inconspicuous; filaments clustered, base about 7 diam.,

echinulata, 249

. Sheaths distinct; filaments some apparently withered, others more

Swanen, base 6-9 ii diamond Mara, BRO

64

SPECIES OF ALG&A.,
86 SCYTONEMA.

On warm sandy soil; blackish; diam. with sheath ro-14y,
thermale, 259
On bark of trees, in small, olive green or brown tufts (a).
On old wet wood (4).
On moist rocks, wall, earth, etc. (c).
Submerged in sweet water. (g).
Floating in sweet water; diam. of filaments 12-204. . matans, 251
# 6 ane - ee Sa: - 14-18 fl cincinnatum, 254
Brackish or salt; filaments curved and interwoven, chrysochlorum, 253

. Filaments bluish; branches forming long loops, ends continuous,

mirabilis, 255

a. Filaments creeping; branches not looped, ends not continuous,
cortex, 256
4. Diameter of filaments with sheath about 20. . éntertextum, 258
d. « ts - i a IO-15f. . stmplice, 259
b. i : "2 ri 20-254. . LHeppii, 260
¢. Mare or less cushion-like, may become confluent (d).
¢. Forming a stratum (e).
¢. Tufted or turflike (/).
@d. On pots etc. in conservatory; filaments bluish, sheath close, color-
ese Ser Ab ee aes .. + Castel, 255
@, On moist rocks, etc; ghiath thick, afte with a lime deposit:
_ cinereum, 258
e. Diameter of sheath 25-33, lamellate . . . . . myochrous, 252

é. Filaments flexuous, long, apices rounded; diam. 12-16-25 p,

SSS

SK SN

cataracta, 252
< entangled, branches ee single; cell ends somewhat
contracted 20.5 5, . . gracile, 253

Filaments interwoven, ate aleenih as ene’ as wide . turfosum, 253
“ sheath dissolving into fibrils,
_Notartssit, 255

. Branches thinner, often % or less than the stem, /ol/ypotrichoides, 250
. Branches thinner at base only, quickly enlarging . MWegeli 252
. Filaments sumewhat curved, branches thinner, bluish,

calotrichotdes, 251

'
87 SYMPHYOSIPHON.

. Diameter of filament without sheath 7, or less (a).

‘6 ‘6 és “ 3 more than 74 (0).

SPECIES OF ALG,

65

a, Diameter of filaments 2-3), of sheath at the base 6-74, apex 3-4)
crustaceus, 263
a. $ € ie rie BE il et od Oe . . . .ambiguum, 262
6. Surface pubescent; black; filaments 9-1 as Bo se wh Castel: 262
b. ” filaments 15-20”. . .. * . Austinit, 262
6. Surface not pubescent (c¢). |
c. Diameter of filaments 15 or less (¢).
ad. Filaments brown, 12-15, cells % as long as wide,
Bornetianum, 261
d. ” bluish, 8-roy, cells about as long as wide hirtulus, 261%
d, % bluish, 8-124, sheath wider at base. fofmanni, 262
88. TOLYPOTHRIX.
§ On tree trunks, surface velvety, blackish; diam. 11-14,
truncicola, 266
§ On wet exposed-rocks (a).
§ Aquatic (4).
a. Reddish brown; filaments with dark transverse bands,
Ravenellit, 265
a. Red, purple and black; filaments much branched . rufestris, 265
b. Spherical, pea-like masses, filaments bluish . £gagrophila, 264
6. Not spherical masses (c).
Pr eeeereT. Ol MUaIMeILS BA oe ee RES aoe
c. Diameter 10-17) (2).
¢. es g-I TM, often interrupted by inclined disc-like cells,
muscicola, 264
d. Impossible to separate here, dstorta, 263; pulchra, 264; flaccida, 265
89. PLECTONEMA.
OT eR ean aye Oteog gy be UEC as a IO a
gO. PETALONEMA.
CR ee ey eh ea Aa Se at Do aR ae
QI. SIROSIPHON,
§ Aquatic; brown; cells of stems 2-rowed, in branches 1-rowed,
ocellatus, 272
§ On old wood and tree trunks; in black spots; often aggregated,
lignicola, 273
§ In soda springs, west; not fully described . . . Branidegeei, 274

S

On damp soil or wet rocks (a).

SPECIES OF ALG#,

. Branches polymorphous (2).

a
a. Branches not polymorphous (¢).
6. Apices obtusely rounded (c).
6. ‘attenuate, or filaments with scattered spines, A/p~inus, 269
c. Plants attached only by the mucus surrounding them,
‘ pulvinatus, 268
c. Plants firmly attached to rocks and stones . . coralloides, 270
d,. Diameter of filaments about 50. Alpine . . . . Cvrameri, 273
a, . « ai less than 5oy (e).
e. Cells broadly ovate, moniliform; on wet rocks . compactus, 271
e. Cells small, not moniliform (/).
jf. Filaments flexuous, curved, not a lie branched, 16-17,
scytonematotdes, 271%
J. is short, intricate; branches many, irregular (g).
g. Mature sheath deep reddish brown, of branches yellowish, apices
colorless a8 . . @rgillaceus, 274

So SP

. Mature sheath Soloripee foulibe. rately light yellow crustaceus 274

92. HAPALOSIPHON,
Aquatic, often parasitic (a).
On tree trunks (c).
On wet rocks(¢).

. Diameter of filaments about 154; much branched, bluish; sheath

often yellowish brown . . Va Crea, 276

. Diameter of filaments less than nee (2).
. Cells about as long as wide; filaments 10-124 =. . Braunii, 275
. Cells about as long as wide; filaments 7-8, branches 3-4),

tcnutssimus, 277

. Cells equal to twice as long as wide; filaments 8-11

fuscescens, 277
Filaments 20-254, branches rather thinner. . . dyssoideus, 276

. Filaments apt to be solitary, cells moniliform, bluish,

torulosus, 276

93. NOSTOC.

Fronds soft, often without definite form (4).
Fronds globose or nearly so, or discoid or linear, often irregular
with age (JB).

A, Aquatic (a).
B.
B

Aquatic (¢).
. Terrestrial (0).

i a oe aa tee

sy 0g OG

Ss s,

bg Sts

DSR QR MOM

. Cells of two kinds, unequal (A).
. Cells uniform, regular (2).
. One kind elongated, the other spherical; bluish . ceruleum, 284

SPECIES OF ALG&, 67

. Without ‘mucilage; filaments in irregular masses, coiled,

tenuissimum, 282

. With mucilage; joints equal, rather distant . . comminutum, 282
. Soft, becoming gelatinous cushions (e).

is is tongue-shaped, plane, irregularly expanded (2).

. With a firm coating (/).
. Fronds with a firm coating (g).
. Mature frond suborbicular, often perforated and expanded,

commune, 283
‘ “ linear, straight, long; filaments parallel,
: flagelliforme, 285
Globose thalli within a subspherical gelatinous mass, muscorum, 282
Globose, firm; filaments olive . ... . . . humifusum, 282
Suborbicular, soft; filaments bluish green . . . . calcicola, 283
Globose, firm, coating brownish; joints subspherical,
sphericum, 283

af soft, sheath often colored and general mucus colorless,
rupestreé, 283
. not 1 mm in diam.; cells cylindrical, slightly constricted,

macrosporum, 284

. Fronds globose, from 2 mm to size of acherry . pruniforme, 284

“« rounded or discoid, becoming hollow (7),

Fronds subglobose, warty, brownish green . . verrucosum, 284
Fronds suborbicular, erect, smooth, tenacious . . Alpinum, 285

94. ANABAENA,

On tree trunks, near the water’s edge, bluish . cupressaphila, 288
In brackish ditches; stratum bluish . . . ._ oscillarioides, 288
In sweet waters (a).

. Cells 3-4 in diameter (2).
. Cells 4-11zin diameter (c).
. Deep blue green; filaments curved, almost parallel,

variabtlis, 287

. Pale bluish, sometimes yellowish; filaments curved, usually in

GCUIStErS <u ws. PSPS ORION ae ig Tat US og? A fe

. Filaments curved, often coiled . .. . . . . flos-aqua, 286
. Filaments straight, often coiled when young . . gigantea, 287

68 SPECIES OF ALG.

95. SPHAROZYGA,
§ Filaments in 2-4 in. long, vertical, closed tubes, % in. thick, more

orlessattached . . . . a hy) CCM, ae
§ Filaments straight, in a definite pelcacis sheath; joints subspher-
ical, spores cylindrical . . , . pei eae a=: a RR, ei

§ Filaments equal, curved or coiled in dein bluish stratum,
Hassallit, 289
_§ Filaments subsolitary or associated, bluish, variously curved,
polysperma, 289
96. APHANIZOMENON.

CONG SPECTER SA Pe ee te Ro ne

97. NODULARIA.
ONE SPECIES 658 ES Pe ais go

98. CYLINDROSPERMUM.

§ Spores about 14m in diam.; cells3-4 . . . macrospermum, 292

§ “ “ IOofl (a).

a. Diameter of cells about 4u . . . . . . flexuosum, 292

a. $3 5 gees “ 3m; terminal cilia with flexible, hair-like
filaments Sia EO EROS i gre ah Se Gti ce a

99. CRENOTHRIX.
One Species. 5) i wi IR EL On Nae sees ke be ene

100. CHAMSIPHON.

S Length (16-196) et ks Oe ee ee ee
Br On Pome 8S Lida add pe ea ee ee

IOI. LYNGBYA.
§ In brackish water; filaments rigid, curved; cells 3-4 times wider
than long, dian. 26-20 4003 oe oe Sa, estuarit, 296
§ On moist ground or wet rocks (a).

§ Aquatic (g).

§ Marine. . . . . mazguscula, 297; vermicularis. Omitted.
a. Stratum bright eres: filaments 8-roy in diam. . arenarium, 299

a. Not pure green (0).

4. Stratum blue green (c).

6, Stratum blackish green (e).

b. Stratum blue, red, purplish, olive, brown or becoming yellow (/).

SPECIES OF ALG. 69

. Filaments 4m in diameter, curved; substratum whitish,

inundata, 303
Filaments 3-3.5 in diam., slightly curved . . . cataracta, 302
Filaments 7-8 in diam. (@).

. Cells finely punctate;on rocks ... . . . ruprestre, 300
. Cells not punctate, joints somewhat pontracted: moist ground, Fla.

subtorulosa, 300
More or less radiating; apices obtuse . /uliana, 301; Retztz, 302

. Filaments straight, sheathed, s-gu diam. . . . . vulgaris, 300

ff slightly curved or flexuose; with sheath 40-80y diam.,
pallida, 298

¥: forming a purple stratum, long, waving, 8-9 diam.,
tinctoria, 301

.Inalpine lakes or marshes ... . . . . . cincinnata, 296
. Not alpine (2).
. Tufted on stones; filaments 40-45 to50-6ou diam. . Wollet, 297
. Ina stratum or floating singly (7).
Filaments 12-184 diam. . . SAD ey ise OOEUTAS 205
i 7-9.5 diam., matted; wie das bottoms,

phormidium, 299
os 5-7 diam. (7).
Stratum thin, paper-like, substratum, pallid, of empty sheaths,
papyrina, 302
membranous, mucous, filaments yellowish,
interrupta, 302

102. SYMPLOCA,.

Stratum dull green or blackish; filaments 4-6 diam.
Friesiana, 304
Stratum bluish green; filaments 3-4, Jlucifuga, 303; fuscescens, 304

103. MICROCOLEUS.

On rocks or moist earth (a).
Aquatic (0).

Diameter of filaments 3% to4¥4u . . . . . anguiformis, 306
‘“ “ “ BOGE oe a es HOP Ore eS
‘ ‘< ‘ tee goes Rs Ravenellit, 307
‘6 6 ts 10-134; ina Hie membrane amorpha, 304

. Stratum cushion-like, large, 6-8 in. or more in diam.,
jai: 305

ws

§
S
§
§

SRAMYANA ARK KARAARH HAHAH H&HeSHesg

SPECIES OF ALG&,

“* thin, skin-like,expanded. .. . . . gracilts,
‘* dense gelatinous, on partly pubsimered stones,
. heterotrichum,

104, OSCILLARIA,

Articulations indistinct (a).
f: about as long as wide (c).
‘c one-half 6“ “c “é “c (Z).
“© less than half as long as wide (7).

. In hot water from waste steam pipes; diam. 1.8—2.8 y,

amphibia,

Not in hot water (4d).

Filaments 1-1.5uindiam. ... . . ... . subtilissima,
rs Ti—-255 BT IA ec, eee ects tenerrima,
nf 2uindiam. . . ATT sega hey ta a detersa,

Diameter 2.8—3y, Tarely : 35 Miho a See Gn ee ee,
Pye ey) ME ie ore eer Peg
“i RM SOROS . . Chlorina, leptotricha,
ui 4.5-5.5; on mice oehwnd iememnercn ng

. Floating on hot water; diam.6-7u .-. . . . Cortiana,
. On wet ground (e).
. Aquatic (/).

Diameter 4.5-5@; on shaded mud .... . . .. 6revts,
i 4~4.7 ; INjgreenhouses: 605 ys as violacea,
. 6-7.7544; in swampy places... . . . &mosa,
2g 7-8; wet grounds, Fla... . . . . . chalybea,

. In large jelly masses; diam. 4-5-6 . . . . . . cruenta,

. Not in distinct jelly masses (g).
. Stratum black (A).

“bluish or not black (7).

. Filaments with two short cilia at the end; diam. 4.6-6.6y,

subfusca,

. Filaments without cilia; diam. g-1ow . . . . . . migra,
Diameter 9-114; stratum thin . . . . . 1. anguina
rs Fs) | RM Re em ee eas ities 313; watans,

a Am S ft Ee Ok GE oe Ia ee

In brackish or submarine waters (2).

In sweet waters (/).

Diameter 18-20) (0.0 0 ae ee eee
ES 1.7 Ava na yay Mum mime era ee

3°7

310

3599
599
310
310
311
311
310

313

312
311
313
314
312

312
315
314
314
311

316
317

SPECIES OF ALGZ,

Z, Diameter 30m or more (m).

m. Cells 4 to 4 as long as wide; diam. 30-45 . . . princeps,

m. Cellsabout { aslong as wide . .... . . . dtmperator,

n. Diameter less than 19p (0).

n. a rgft or more (/).

o. Diameter 154; cells 4-4 aslongas wide . . . percursa,

0. if to-18m; variable . . . . goad: le Qt ROE SAL,

p. Diameter 19-22; cells 4-% as long as wide eta I: POP

p. . 23-28; cells $4 “ “ “ “ | Bonnemasonit,
105. BEGGIATOA.

a, eemeter of filaments 1-21.55 fo ee naoeum,

a. 1.8-2.54 .. . . . leptomitiformts,
106, LEPTOTHRIX,.

§ In hot waste water, waving,6mmthick . . . . hinnulta,

§ On old wet walls; filaments strongly curved . . . calcicola,

§ On wet wood, herbaceous green; diam. 1.8-2.254 . herbacea,

be less than 304 (7).

§ Aquatic, sometimes on wet rocks (a).

7

317
317

335
315
316
316

318
329

320

319
320

a. Forming spherical masses, light ee tough, hollow, 4-8 mm
diam): (59. sive aes, Tee Fae
a. Forming elouddtike: dating fiaetle masses, yellowish; filaments
BOC Fie er ae ae. See
a. Forming a stratum (0).
a. Forming a tuft (e).
OC EMaents sf OF MOTE Giana ur eS RO may B99
b. : less than 3y in diam. (c).
c. Stratum composed of clusters, light bluish . . . rigidula, 321
op ¥ more or less expanded (@).
d. Bluish or greenish above, yellowish or colorless below,
laminosa, 321
d. Bright bluish, thin, membranaceous . . . . . @rugined. 319
é. Bluish, becoming yellowish ..... . . . cespttosa, 320
é:: PUTBIG @reeiror ceetityst se pk at sui ROE B28
106@. ASTEROTHRIX.
SORE ONE CI eon as oo eee eh Ce ae pus eA OPER NY Gee

72 SPECIES OF ALG#,

107. SPIRULINA.

§ A continuous, twisted, ring-like band. . .°. . . duplex,

§ Not continuous but filamentous (a).

a. In stagnant water; diameter 7-84 . . . . . . Jennert,

a. In sulphur springs; diameter 4-5 uw. . ws SC. Lemuttssima,

108. SPIRILLUM.

One Bpecies. ee Be ee RE epg tose enna ae
109. GLCOTHECE.

CONG SPECIES «8a. OAS, Us oe ee eae een
IIo. APHANOTHECE,

a. More or less globose, size of a cherry, usually floating,

prasina,
a. Gelatinous, 4-6 mm thick, in small masses; wet ground,
pallida,

IIt. SYNECHOCOCCUS.

ne species; on ‘wet rocks 33 ks i eee ea
II2. MERISMOPEDIA.

a. Rarely more than 4-64 cells, 3-5 diam... . . . glauca,

a. Often of 256 geminate cells, 4-4.54 diam. . . . convoluta,
113. CCLOSPH#ARIUM.

One Species... 9 PF, ee er
114. CLATHROCYSTIS.

CONG SHEDS. oo ie Be ge eee aeruginosa,
II5. GOMPHOSPHARIA.

GHEe'Species 8 Se ee

116. MICROCYSTIS,
One species; on moist timbers, ground, tree trunks, protogenita,

117. ANACYSTIS.

a. Cells ruin diam.; thallus light brown . . . . . drunnea,

a, Cells 2-3 diam. ** glaucous or pale bluish . pulvereus,

a. Cells 3-44“ “« globular, margins colorless,
marginata,

118. POLYCYSTIS.
One SPECIES 6 Ee OE el eee

343

323
323

324

325

325

325

326

326
326

327
a7
328
328

329
329

329

339

SPECIES OF ALG&, 73

I1g. GLOeOCAPSA.

These forms have been divided into as many species as there
are different colors to the cells or to the integument; they are green,
red, black, brown, coppery, orange, yellow, olive, purple or colorless.
They have no value as distinct plants, being phases or stages of de-
velopment of higher Alge. Mr. Wolle considers them to be spores
Ge mammrumouidis, Of Siremphgn ee ae

120. APHANOCAPSA.
Se meereca: thallus gionose:. oer ce Gremller 333
= Cn.wet rocks; thallus expanded 20.0.0 2.00... virescens, 333
: I21. CHROOCOCCUS.
a. Cell contents bright bluish, becoming brownish; 13-25 4 diam.
\ turgidus, 334
ty - reddish or yellowish brown; 12-16y diam.

rupescens, 335
Sg . blue green; 3-6u diam. . . . . . coherens, 335

BAO EL.

Key to the Genera and Species of the

Desmidiez.

A KEY TO THE GENERA AND THE SPECIES OF THE
DESMIDIE:.*

Plants composed of symmetrical cells, usually constricted in the
middle, often of beautiful, ornamental forms, single or conjoined
into filiform series, and sometimes involved in a maternal jelly,
Asexual multiplication takes place by transverse division, or by sep-
aration of the semi-cells, and by development of new parts similar to
the mother semi-cells.**

*The greater part of the following key was originally published in ‘“The American
Monthly Microscopical Journal,’”’ and is here reproduced by permission of the editor.
**Wolle: Desmids of the United States.

KEY TO THE GENERA OF THE DESMIDS.

§ Cells united into filaments (a).
§ Cells not united into filaments (g).

ROX & esas

Te Oa ee

. Ina transparent, jelly-like sheath (3).
. Not in a jelly-like sheath (¢).
Cells with 2 teeth on each narrowend. . . . . WDesmidium, 6
. Cells deeply constricted, almost into two parts (c). |
. Cells not deeply constricted, and without teeth . . Ayalotheca, 3
With ‘claspers’ across the sutures . . . . . . Onychonema, 9
Without ‘claspers;’ cells united by a narrow isthmus, Spherozosma, 8
. Band not twisted; cells with ‘claspers’ across the sutures,

Onychonema, 9
«“ a cells without ‘claspers’ (ce). _

. Band twisted; cells triangular or quadrangular . Desmidium, 6

Cells barrel or hub-shaped, with 1 or 2 median bands, Bamdbusina, 4
4 ; nd without bands, the sutures projecting,
Leptozosma, 5

e. Cells cylindrical, sometimes swollen at base (/).

NS

we Oe MW NN

. Cells quadrangular, deeply constricted, often slightly twisted,

Phymatodocts, 7

. Ten to 30 times longer than broad . . . . . Gonatozygon, 1
. Three to 6 times longer than broad . . . . . Genicularia, 2
. Cell more or less crescentic. . . pode ge Ose OSE SILI, Ee
. Cell cylindrical, fusiform, dumb- bell or hour-glass shaped (2).

. Cell flattened; orbicular, oblong, or elliptical (4).

. Mostly prbisuiae or broadly elliptical; centre deeply constricted,

the semi-cells 3-5 lobed, the lobes entire or variously incised,
Micrasterias, 22

. Mostly oblong or elliptical; margins wavy, the depressions rounded;

ends usually notched or incised . . . . . uastrum, 21

NON a a SS. SS BO,

NON

ys 'T SWS S RR YY

GENERA OF DESMIDS.

. Cell constricted in the middle; no arms nor spines (/).

cf if with arms or spines (/).
Cell not constricted; no arms nor spines (7).
yet cylindrical, ends simply notched . . . . TZetmemorus,
sa as ends rounded, truncate or divided (2).
. Cell more or less dumb-bell, or hour-glass shaped (4).
. Cell 6 to 30 times longer than broad... . . Docidium,
. Cell 2-5 times longer than broad; ends rounded, Cadocylindrus,
. Arms 2, 3 or more, radiating . . ce & ' Saurastrum,

ulate dabeccle: spines usually numerous and marginal,
Xanthidium,

. Arms none; no central tubercle; spines 4 to 8, two on each end,

‘ce 6 spines 16, four on each end,

A ‘thiedeaane
. Chlorophyll in one or more spiral bands . . . Sfirotenia,

ms not in spiral bands (7).

. Surface rough with tooth-like or rounded elevations, Z7zploceras,
. Surface without tooth-like elevations; ends rounded (0).

. Cells in mucus, short, cylindrical or oval . . . Mesotenium,
Pa oemoL Or yarely I mucus — 95 . PE,
. End view 3-6 or more angular (7).

. End view not angular (s).

. Angles obtuse, acute, or with horn-like prolongations,

. Staurastrum,
. Margins smooth, dentate or crenate; no spines . Cosmarium,

79

18

14
16

23

. Arms none; semi-cells with a eas rounded, truncate or dentic-

>

20
It

15

Io
I2

23
|

KEY TO THE SPECIES OF THE DESMIDS.

1. GONATOZYGON.

. Cells swollen at base, with 6 longitudinal lines of short sete,
sex-spiniferum.,**

. Cells not swollen at base (a).

. With hair-like spines clothing the surface . . . . fpélosum, 22

. Without hair-like spines; surface minutely roughened, asperum, 22

2. GENICULARIA,* FIG. 2.

. Cells 3% to 6 times longer than broad; granules in spirals,
Americana.*
. Cells ro—-12 times longer than broad; granules scattered, spirotenia.*

3. -HYALOTHECA. FIG. 3.

. Cells slightly constricted, length % the width, sides not notched,
disstliens, 22

19 a oa i! “« sides arched, cen-
traity rotcheds.)7::..% pe ale AS aoe

2. Cells slightly concave, iehotn twice the wads . . undulata, 23
. Cells not constricted, margins straight; sheath wide, mucosa, 23
4 4 “ Sheath absent, dubia, 24

4. BAMBUSINA. FIG. 4.
. Cells hub-shaped, somewhat longer than broad . SArebissonit, 24
. Cells hub-shaped, nearly twice as long as broad’. gractlescens.**
3. Cells subcylindrical, 4 times longer than broad . delicatissima, 25

*Journ. R. Micr. Soc., Dec., 1885.
#*F W. Alge, p. 21.

SPECIES OF DESMIDS. 81

5. LrEprozosMa.

An immature form of Desmidium, 6.

S AY LS Q& Qe

NNR

6. DerEsmipium. FIG. 6.

p ieads sieath present. 23. eylendricum, 25

. Mucous sheath absent (a).

. Cells united by their entire end margins (4).

. Cells united by the outer portions of the ends (¢).

. Cells nearly twice aslongas broad . .. . . . longatum, 26
Cells less than twice as long as broad (c). |
Cells in side view quadrate . guadratum, 26; guadrangulatum, 27
Cells in side view triangular’. . .°. ; .°... . Swartstt, 26

. Borders crenate or undulate . . aptogonium, 27; diagonum, 159

. Borders straight, filament twisted . . ... . . Batleyi, 27

7. PuHyMatTopocis. Fic. 7.

Re ea el See 2 Aordsbeinanum: 28

—

KASS SsSRnrn-

ES

8. SPHAROZOSMA. Fic. 8.

. Cells twice éroader than long, lobes not constricted (a).

“ Ms “ “ lobes constricted near the end,
constrictum,**
. Cells twice /onger than broad, in sheath or not . excavatum, 29
. Cells less than twice longer than broad (6).
. Cells closely approximate, ends rounded . . . . pulchrum, 29
As a eh ends truncate, concave, rectangulare, 31
Cells more or less remote, ends rounded . . . vertebratum, 30
Ends pointed; semi-cells remote; sinus deep, wide, *monzliforme.**
Ends rounded, spinous; cells slightly constricted, spznulosum, 31
Ends rounded, not spinous; cells deeply constricted, fliforme, 29
Pree srmcate, CONCAVE) 6 re te oe eWeek, 30
minds truncate, mot concave © ...:0-. 0.0 soe. | pulchellum*®*

9. ONYCHONEMA.* FIG. 9.

. Cells with spine-like projecting ends ... .-. . = serratum, 30
. Cells without spine-like ends . . . . . . . Wordstedtianum.+

10. MESOTANIUM.. FIG. 10.

. Cells cylindrical (a).

Cells oval or elliptical, about twice longer than wide, in mucus on
WU Oe gore OR ce OCCU, 32

*Mr. Wolle joins this to Spherozosma. + Journ. R. Micr. Sec., Dec., 1885.
**F —w, Algee, .pp 23 ef seq.

82

a.

a,

QR 2 - A

R Rw N

Raney Peers

NX &

SPECIES OF DESMIDS.

Mucous masses floating; cells 2-2% times longer than wide,
Braunit, 3%

Mucous masses mingled with filamentous algze; cells 3-4 times
longer than wide Endlicherianum, 32

. Mucous masses on wet rocks and? mosses; cells 2-3 times longer

than: witke 3) eA Ot a ae ee
II. SPIROTANIA, FIG. II

. Spiral band single (a).

~ Spiral bands more than one... 350 ck, Whee eee as
_ Cell 8 to 10 times longer than broad . . . . . condensata, 33
. Cell4timeslongerthan broad . ... . . . O6ryophila, 33

I2.:. PENIUM:, ... FIG. 22.

. Chlorophyll interrupted by 1 central transverse band (a).

‘“ ‘6 “‘ 3 transverse bands; cytioderm smooth,
interruptum, 35

ée &< 6 66 ‘< “ cytioderm spirally
Striate © 2c ies Fey al a SPAT OSLO DEGTE”

. Chlorophyll sonceatteieds into 2 or more nuclei; in mucus, crassa, 37

a diffused (0).

. Endstruncate, square .. . ny nee at A TREE SR
. Ends not truncate; cells slightly worethioued: sides straight,

minutum, 35

‘“ ‘ ‘6 ‘“ ‘< “ sides convex,
cructferum.**
6 x as cell not ae 3-5 times longer than
WIGE borane: Bee ee Cad ee

. Ends not truncate; Celi not sonata: gel times longer than

wide: if@2%2 SS SOAS | ROT a Gs rc or

. Cytioderm smooth (c).

ee with pearly granules in longitudinal rows,
margaritaceum, 34

Cells in mucus, diameter 34, to z4, in. (63-83) 3 to 4 times as,

long aswide .... . . . . oblongum, 34

i) REA OE Ce aa iphes as ivide i Hiile 1204 MP ESTPE,” 29

«< “more than 3 timesas long as wide . Arebissonii, 36
Cells not in mucus; each semi-cell a truncated cone . stumidum.**

. Cells oblong, often slightly constricted . . . . Jlamellosum, 34

. Cells subcylindrical, in families of various sizes intermingled,

polymorphum, 36

. Cells subcylindrical, not in families . . . . i fernere, 26
. Cells broadly fusiform, 4-5 times longer bed wide: navicula, 36

**J. R.M.S., Feb. ’89.

S
S

Nn ON

ey sais Pe SY & Q&RQN

AO OR

SPECIES OF DESMIDS. 83.

13. CLOSTERIUM. FIG. 13, @, d,c¢.
Ends not or but slightly produced (1).
Ends produced into long, often setiform, beaks (2).
. Cells straight or slightly curved; ends slightly tapering (a).
a as se 5 if dorsum convex, ventrum nearly
straight (¢).

. Cells conspicuously curved; ventrum concave, with a central in-

flation (2).

. Cells conspicuously curved; ventrum without an inflation (7).
. Body margins equally convex; beaks longer than body, cetaceum, 47

ets « “beaks % as long as the body,
pronum,.**

. Body margins not equally convex (mm).

. Length 5-12 times the width (4).

. Length more than 12, less than 20 times the width (e).

. Length 20 times or more than the width (/).

. Ends suddenly contracted; cell fusiform, 5 times longer than wide,

SMM aig . . . masutum, 41
Ends not contracted, Hut Gerag, Site: ehorophyi bands sev-
eral grandest foW 2. i. a. Sanceolafum. 39

. Ends not contracted, rounded (c).

yi : truncate (2).
Cell slightly curved, small, 6-12 times longer than wide, smooth,
acutum, 44

“ ts bs 5-10 longer than wide, smooth, odtusum, 38
Cell nearly straight, decussately striate . . . . decussatum, 39
bs x ** smooth, apices obtusely rounded, addymotocum.*

. Cell slightly curved, 6-12 times pees than wide, striate; vacuole
Gistinct i 4 ei . . . . @tdymotocum, 39
Cytioderm with 4-5 eristeudintal strie, often with 2 or 3 transverse
bands and decussating strie . . . . . angustatum, 40,
Cytioderm striate; ends slightly incurved; globules about 20 in each,
eemi-cell axillary 5°; 2. Seika 2 COMORES ee
Cytioderm striate; ends truncate, corners rounded; with three
Seeererse Butaies OS Pe ee. sabdircthan >
Diameter 2 orless;smooth .. . . . gracillima-levissima.*

Diameter 3-4; slightly curved, smooth, or with 1-4 trans. striz,
subtile, 158
" RE ee MICE Ge yg epee ee ye Se RU Oey AO

S 10-1644 (4).

*F —w. Alge. p. 23 ef seg. **J. R. M.S., Feb. 89.

84
ne

f.
ee

q
q
«
&

i |

SPECIES OF DESMIDS.

Diameter 18; about 30 times as long as wide, smooth, ends

FOuNdEg SA eee ae ee
. 20-21; striated: éndé raioded” vee anh pheonguam.®
= 364; about 20 times as long as wide, smooth, ends not
curves "5. é Rees Acc

Surface smooth; slightly Sanevins froin the middie . strigosum, 42
ne longitudinally striate only; diam. 11-124, juncidum, 38

‘ ‘“ a with 1-4 trans. striz; diam. 12-13),
mactlentum, 38

. Ends inclined upward at a dorsal depression; ventrum slightly con-

cave; strie fine, numerous .. . i PUNE |r ee gt

. Ends suddenly contracted to a narrow palit: cell slightly curved,

attenuatum, 41

. Ends not suddenly contracted (A).
. Cytioderm deeply striate; distinctly Reaniiets or areolate,

arcolatum, 43
tf more or less distinctly striate; cell linear-fusiform,
15-24 times longer than wide .. . . . @cerosum, 41

. Cytioderm 9-12 longitudinally costate; cell paper aa, 4-5 times

longer thanwide ... . . . . subcostatum,*

. Cytioderm more or less diguisenae striae: may semi-lunar, 5-6 times

longer than wide... . Shvhe ey Sa,

. Diameter 51, to sf, in. (75-1104); eyodern smooth,

Ehrenbergii, 45

Diameter ;4, to zh in. (40-60); globules a single row,
moniliferum, 45; Letbleinit, 46
Ane ay “ cell curved, rapidly tapering into
narrow, somewhat peas fh) ends; cell 6-8 times

longerthan wide ... . oe Sco tee ee
Diameter =}, to x4, in. (35-454); 2 or 3 Sutures in the middle;
about 20 times longerthan wide. . . . . . .° Delpontii.*
Cytioderm with many distinct striz; ee 6-16 times the width;
vacuole large . . . . . . Sstrtolatum, 42
Cytioderm with fine striz; length 12— ioe fies the width; vacuole
SMaa oe. . . decorum, 43
Cytioderm with 5-8 Manet striz; ‘derh 6-8 times the width;
vacuole large .. . .. costatum, 42
Cytioderm smooth; cell crescent- shaped: often ‘subabsbicincutar (2).
a . cell not conspicuously crescent-shaped (/).

. Ends separated 7-10 times the diameter; width ;,4,5 to +> in.

(EORO JE) i oe Fie OSE eee ea ye ir
*F-w. Algz, p. 23.

SPECIES OF DESMIDS, 85

k, Ends separated 7-10 times the i, existe to zq55«Cin.

(25-28) 2 +. . . acuminatum, 44
k. Cell 6 to 8 times longer than wide; ‘ends. obtuse; width =, in.
(14) Ea bod ite Seen fo 7g sae ©
k. Cell 6 to 8 times longer than wide, ends obtuse; width 5,4, in.
eat . . parvulum, 45
k. Cell 8 to 12 a3 longer han wide, aes semicircular, ends
sharp; width 57, to,755 in.(8-10m) . . . , . Venus, 44

7, Cell stout, ends taste rounded; width ,1, to z 45 _*=in. (25-30),
cucumts, 40
m. Beaks slender, nearly as Jong as the body, ends obtuse, curved,

: Kuetzingit, 47
m, Beaks thin, % as long as the fusiform body . . rostratum, 46
I4. DOCIDIUM. . FIG. 14.

§ Suture a projecting or conspicuous rim (a),
§ Suture not projecting (2).

a. Cytioderm hirsute; semi-cell with 3 or 4 undulations, spznosnm, 51

a. Cytioderm not hirsute (4).

6, End dentate or crenate; semi-cell with 1 basal inflation (c).

A og fc “ “« semi-cell with 4 alias inflations; teeth
onthe margin. . . . . constrictum, 50

6, End dentate or crenate; semi- cell wab 3 or more inflations; teeth
below themargin . . . . . nodulosum.*™

6. End truncate or rounded; semi- cat with: 1 or 2 basal inflations,
Trabecula, 48; truncatum, 48

4 ey ‘ ie . semi-cell undulate to the contracted end,
crenulatum, 47
he rs i . i 1-2 undulate at base only,
Archerit.*
c. End with 1 tooth oneachangle ... .. . . Slowtowit, 49
¢c. End crenulate with tubercles . . . . . ¢coronatum, 49
d. Cytioderm hirsute; base of semi-cell slightly faflatodk hirsutum, 51%
d. Cytioderm not teats (e).
e. End dentate or crenate (/).
e. End not dentate nor crenate (7).
J. Semi-cell with 4 or more inflations (4).
if . with whorls of quadrangular prominences,
verrucosum, 52
7. ds with 20 or more constrictions . . . . . costatum, 53
y: “with 1 inflation (g). |

*F.-w. Alge, p. 25.

a

> % OF

SPECIES OF DESMIDS.

. End with numerous pearly teeth or beads . . coronulatum, 49
. End with prominent teeth, about 3 in view . . ¢ridentulnm, 52
. End with 3-5 minute tubercles; semi-cell with 4 or more undu-

lations . . Mee rem TE

. End with toothed annie (i).

Semi-cell with 4 prominent nodes; 8 to to tees longer than wide,
nodosum, 50
as “« 4 constrictions; ro—12 times longer than wide,
breve, 51
¥ “ 8 constrictions; 20-24 times longer than wide,
sinuosum, 5%
Semi-cell with 1 basal inflation (2).
undulate to near the end (Z).
43 with 4 larger and smaller undulations; cells 12 times as
long as wide (m). :
Semi-cells not or slightly undulate; densely granulate, Jdreve, 158

. Cytioderm densely, irregularly punctate . . . . clavatum, 48

pf smooth; ends truncately rounded, margins often wavy, ~
Baculum, 49; rectum.*

ae 3 ends round; cell minute; diam. 7-12),
minutum, 52

a : 2 " cell, large; diam. ends soy,

Woodit.*

Diameter ;,)5 in. (25/4); about 20 times longer than wide,
repandum, 50
Diameter 7755 tO zyp in. (13-164); 15-20 times longer than wide,
adilatatum, 50

. Diameter 3355 tO sy/g5 in. (10-124); 18-20 times longer than wide,

undulatum, 51%

m. Surface punctate; suture none; ends roundly truncate,

Georgicum.*

I5. TRIPLOCERAS. FIG. 15.

(Mr. Wolle unites this with Docidium, 14.)

1. Tooth-like prominences oblong . . . . . .. vwerticillatum, 53

S
§

$6 acute Bia fig cing ig eg Hise tae ad i 52g ios 7 rrr

16. CALOCYLINDRUS, FIG. 16,

Chlorophyll homogeneous (1).
" divided or scattered in each semi-cell (2).

*F.-w. Algz, p. 25 ef seq.

A RAR

YAR ®

so SS 8 Y&R RNR HN HH HH HOD

SPECIES OF DESMIDS. 87

. Length twice the width or less; cytioderm punctate or granulate (a).

6c ‘c ‘“ ‘< 7a sade cytioderm smooth (4).
és ‘ ‘é rT “Ok cytioderm with 5-7 coste,
costatus, 56

. Length 2% or 3 times the width; cytioderm punctate (c).

“« 4to 6 times the width; cytioderm smooth . minutus, 54

. Cell twice or more longer than wide; cytioderm punctate,

pseudoconnatus, 55
“ ‘ “ “ 6 “ cytioderm smooth,
Thwaitsi, 56

. Semi-cell subquadrate . . Pena age ors); i One |
Ԥ cylindrical, rounded; Raeeeelion slight . cucurbita, 54
eS . constriction wide, shallow . . connatus, 55
" sub-semicircular; constriction slight; ends rounded or
somewhat truncate; end view circular . . . Cordanum, *

. Cell somewhat fusiform, ends subconically rounded . curtus, 54

. Cell subcylindrical,ends broadly rounded . . . dadplospora, 56

. Cell subcylindrical, ends rounded; nuclei large, single or double,

Clevet, 56
17. COSMARIUM. FIG. 17.
End view without central inflations (1).
End view with central inflations (2).

. Cytioderm smooth or punctate (a).
si more or less verrucose or granular (/).
ih spinous (g).

; Cytioderm smooth or punctate (Z).
* more or less verrucose or granular (2).

. Chlorophyll diffused (4).

. Chlorophyll concentrated in 1 or more nuclei (e).

. Margins crenate, undulate, dentate or granulate (c).

f not crenate, undulate, dentate nor granulate (@).

Margin crenate (s).
‘“« —undulate (f).
“granulate (z).
“dentate or notched; end truncate, smooth; sides toothed,
CONVEX 8S got ac, tek AR CPMSCRER: OS
Margin dentate; pak 4- sphidd: Sides seek convex, aculeatum, 66

. Cell twice or more longer than wide (7).
. Cell 1% or less than twice longer than wide (A).
. Cells less than 1% times longer than wide (7).

*F.-w. Alge, p. 27.

$8 SPECIES OF DESMIDS.

*~

if

3

Se teks ~ aie |

NON & ews. ®. SSS,

Margins crenate, undulate, dentate or granulate (z).
Margins smooth; basal angles not toothed (zw).
Margins smooth; basal angles each with 1 tooth or papilla,
Smolandicum, 69
Verruce or granules in patterns, or more or less restricted (2).
am . . not in patterns; more or less covering the
surface (cc).
Spines on the whole surface; cell suborbicular; sinus elliptical,
aculeatum, 66
Spines marginal, conical; centre with 7 granules, and punctate,
trachypleurum, 73

. Margins crenate, undulate, or dentate (77).
. Margins smooth (//).

Verruce or granules in patterns, or more or less restricted (zm).
-s . fe not in patterns, more or less covering the
surface (vv). |
End rounded; semi-cell oblong, sides almost parallel, De Baryz, 58

< “ semi-cell spherical, . . . . . moniliforme, 60

fr semi-cell elliptical or oval . cordanum,* oblongumt

End truncate; semi-cell quadrate, sides almost parallel, anceps, 59

ef “«°, semi-cell pyramidal: 2300.0.) pa

. Cell joined by pellucid bands into families . . . Quimbyit, 61
. Cells net joined into families (2).

Ends rounded; semi-cells oblong ... . . . ¢cucumts, 58

i ‘“¢ * semi-cells oval; diameter ;44; in. (23,4),

Witrockitt

Ends truncate; semi-cells pyramidal, sides convex; diameter 4, to

aise (22-284) . . . 2. motabile, 306

bath on truncate; semi-cells cyrotael sides convex; diameter x4, to

shy (50-854) . . . . . . pyramidatum, 69

. Ends truncate; semi-cells pytamndal sides convex; diameter >;455

to zt5 heen sie ay ae . . . pseudopyramidatum, 69

Ends truncate; semi-cells asrasnidat: sides straight or slightly

CONCAVE, 295% 2 bg ee yeramatmnr, Oe

. Cell conspicuously phaddey chin ee semi-cells subsemicircular;
side view circular, end view elliptical; diameter 32-38,
scenedesmus, 59

m. Cell conspicuously droader than long; semi-cells subsemicircular;

side view ovoid; diameter 75-854 .. . . . ctrceulare,**

* Journ. R. Micr. Soc., Dec., 1885. + Journ. R. Micr. Soc., Feb., 1886.
** FW. Alge, p. 27 ef seg.

Mm,

2.

SPECIES OF DESMIDS. 89

Cell nearly as long as_ broad; semi-cells rhomboid, sides all
equal: sinus deep, wide... <.. . . . rhombusoides.**

. Ends rounded; semi- -cell subcircular, sinus a mere notch,

globosum, 60
_ g semi-cell subsemicircular (0).
. . semi-cell oval (7).
2 a semi-cell elliptical, or hexagonal-elliptical; cell 4
longer than wide; diam. 25-42, sexangulare, 63

. Ends rounded semi-cell elliptical; cell % longer than wide; diam.

A POM 2 . . microsphinctum,**
Ends truncate; semi- heel hemos diameter ag in. (21) or
OS aaa . . . polygonum, 65

Ends truncate; semi- cell triangles: inmicses siz in. (50) or less.
galerttum, 7°

. semi-cell subsemicircular, smooth; sinus deep, nar-

row . . . nitidulum, 62; psendonitidulum, 62
ve . punctate or granular; si-
nus narrow ALC Ur Cede cum lobulatulum.*

Sinus deep, narrow ( ).

. Sinus deep, wide, almost linear; cytioderm smooth, sejunctum, 62

% rounded or oval; semi-cells lunately curved; cytioderm

DUNC LAMe gs So a fematam, Os
Sinus deep, wide, obtuse; semi-cells idenine from a narrow base,
inflatum.*

Sinus acute angled, enlarging outwardly, rarely linear,
per foratum,*

Per eluptical; basal anglés acute ©. 5°. 2... Batley, G4
. Cell suborbicular; basal angles obtuse; diameter 54, to z4, in.
[DOXTOO} i ee eh a ae, OS
: ca “ diameter giv to ghy in.
£3-38), 85. Se wat eae 3s constrictum, 58
. Cytioderm centrally somewhat soaular nucleus 1 in each semi-
Wee aah aay tumidum, 61

¢ smooth or punctate; eelts shall

bioculatum, 60; tinctum, 61

Peis rounded; semi-cells semi- porpiemiar; crene usually 9,
undulatum, 67

x s¢ semi-cells subsemicircular; margins finely crenulate-
MGHCAte re ee Ge eg a 2 oc ORR

* Journ. R. Micr. Soc., Dec., 1885. + Journ. R. Micr. Soc., Feb., 1886.
** FW. Alge, p. 27 et seg.

go SPECIES OF DESMIDS.

s, Ends rounded; semi-cells subsemicircular, with 8-10 crenulations,
Sendtnerianum,*

s. Ends truncate; semi-cells pyramidal; cells small, . . motadbile, 66
Ss sides almost parallel; inmate gy tO ghy in.

(30-384), . . . . erenatum, 67
S. sides converging; diameter ae: in. (20/4),

Negelianum, 67
¢. Semi-cell quadrate, smooth, angles rounded; end retuse or convex,
guadratum, 59

Z. pyramidal or subquadrate; end undulate, Reina 68

£ as . end truncate; diameter =1, to <4, in. (32-36),

integrum, 68

Z. ‘ rx a diameter 3p/5y tO qo'gy in. (20-24),

| Hammert, 79

Z, ‘s sf end rounded, surface smooth, octogonum.*
z. Semi-cell pyramidal, punctate, base flat, angles rounded,

ansatum, 68; Vymannianum, 79
z. Semi-cell sub-semicircular, end truncate, sides with 2 .emargina-

tions; smooth (0<))5'2. 7% Pie More P ee ie
uz. Ends truncate. Diameter <4, to > tra in. (20-30f), punculatum, 74
uw. Ends convex. Diameter >s45 to ayy in (14-16) . . lave, 62

v. Cell twice as long as wide, rectangular; sinus linear, not widened,
sinuosum, 05
v. Cell less than twice as long as wide; semi-cell pyramidal,

venustum, 68
v. se " +4 ie semi-cell subquadrate, small,
Meneghinit, 65
w, Sinus narrow, not eidied outwardly; cell elliptical, end convex,
vartolatum 63; exiguum, 66
w. Sinus widened and rounded ete: narrowing outwardly, cell
wider than long .. . : . . . obsoletum, 64

w. Sinus widened outwardly; semi- oan ‘oval hase and end convex,
contractum, 63

WwW. a os " base and end flattend,
depressum, 64
w. Sinus widened outwardly; semi-cell quadrate, Meneghinit, 65
w a Ss semi-cell subsemicircular, end rounded;
diameter 51, to x4, in. (75-100) . . . . pachydermum, 70

x, Margins crenate or granulate (7).
x. Margins not crenate nor granulate (40).

* F.—w. Alge, p. 27 ef seg

SPECIES OF DESMIDS. gti

y. Central verruce none or scattered on each semi-cell (2).

y- as more or less clustered on each semi-cell (aa).
zg. Verruce none central, si ons I or 2 rows; cell about twice
longerthan wide... Ce et ROE
g. Verruce none central, Rcinal ¢ I or two rows; ea less than twice
ionger than wile. triplicatum, 73; LVordstedti1, *
gz, Verruce centrally scattered, marginal in series of 3 each; semi-
cell quadrate, anglesrounded .... . . triplicatum, 73
aa. Central verruce 3, in a single row; surface smooth, Donnellii, 71
aa, ' 3, 2 above the base; punctate between,
| polymorphum.*
aa. “f 5, in 2 transverse rows, a row within the margin,
guinarium,*
aa. : 6, in a triangle, apex toward the isthmus,
polymazum, 70

aa. se 6 or g, in 2 or 3 transverse rows; marginal rows
I or 2; semi-cell semicircular, <K7tchellit, 72; suborbiculare 78

aa, Central verrucze 10; semi-cell semicircular, end _ truncate,
antsochoudrum, 72

aa. “g circularly clustered; semi-cell twice longer than
wide, sides emarginate, ead truncate . . . . Seelyanum, 73
46. Centre granularly rough and punctate; margin smooth; semi-cells
Oe ae : CaO Sean Oe

bb. Centre with 3 verruce ina row; semi- cells semicircular,
Donnellit, 71%
46, Central verruce 1 at the isthmus, 8 or 9 marginal in 1 or 2 curves,
taxichondrum, 71

bb. e “: 5 arched near the margin, 4 be-
low these in the formofacross . . . . btdentulum.*
bo. - 4 nearthe isthmus; semi-cells semicircular; end

somewhat truncate; basal angles often pointed,
pseudotaxichondrum, 71
46. Central verruce 7, 1 central, 6 below in a semicircle; ends retuse,

SOOT Ss oe ee ia leg
bo. Central verruce 19; : larger, oanal 12 more or less distinct
aroundthem . . PRESS Per oe et ee, CRE COAET:
cc. Chlorophyll diffused (dd ).
ce. “ concentrated into r or 2 nuclei (ee).
ad. Marginal verruce or granules rounded (42).
ad, 5 “ conical or pointed (zz).

*F.-w. Alge, p. 27 ef seq.

g2 SPECIES OF DESMIDS.

ee, Cells twice or more longer than wide (/).
ee. Cells less than twice longer than wide (gg).

ff. Cells cylindrical, sides parallel (sometimes rounded); verrucz ob-

tHSO SCA Se ese . . amenum, 78

Ff. i r “3 verruce enane: in lines,
elegantissimum, 78
gg. Semi-cells oval or elliptical . . . sumidum, 61; orthosticum, 78
gg. “ semi-orbicular, setraophthalmum, 75; intermedium, 75

hh, Semi-cells pyramidal, end truncate; basal angles rounded,
octhodes, 76; Botrytis, 74

hh. Semi-cells oval or elliptical, approximate . . . . trigonum,*
margaritiferum, 75; punctulatum, 74
hh. ae * - remote, granulate, portianum, 77

Ahh. Semi-cells quadrangular, ends truncate; diam. 1, — 31, (60-73)),
conspersum, 75

hh. s : ends concave . . . . retusum.*
hh, : e diam. y4,-sh (s5-s35 0).

pseudobroomet, 86
hh. i es diam. +9/sy —adss (13-144),

sphalerostichum.*

hh. Semi-cells subreniform, sinus widened and rounded inwardly,
latum, 76; reniforme, 76; pardalis.*
hh. Semi-cells subspherical, approximate . . . . orbiculatum, 77
hh, Semi-cells hemispherical, remote; base flattened, excavatum, 77

zz. Ends and sides with teeth; sinus narrow, widened outwardly; basal
angles rounded 2.04: page SC CSSONE Ek
. Ends without teeth, sides with 10 to 20; sinus gaping, dentatum, 76

I- ae crenate; semi-cell semicircular, nuclei 2, end truncate,
cructatum, 8%
rr 4 undulate; sinus widening outwardly, homalodermum, 81
J. “ « sinus not widening outwardly (£2).
kk. Cell longer than wide; SOE aay to zt, in. (38-44),
sublobatum, 80
kk. Cells longer than wide, diameter 45 to zopq in. (22-25),
margaritum, 80

kk, Cell not ak. than wide, endtruncate ... . ~retusum, 80
“i, Diameter 755 in. (124), end truncate; sides convex, often ob-
tusely angled centrally . . . . . Schliephanckeanum, 82

i, Diameter greater than (12) sj5q in. (mm).
*F.-w. Alge, p. 25.

SPECIES OF DESMIDS. 93

wm, Sinus acute inwardly . .. . . . . . thithophorum, 80
mm, ‘ rounded and widened baeeactily ie ug Phaseolus, Br

. mm, “ rounded, but not widenedinwardly, pseudogranatum., 158

nn, Margins crenate or dentate (00).
nn, Margins smooth; centre with one verruca; semi-cell elliptical:

Gimmeter in. (19) a eS tw Otrremme, 82.
oo. Ends truncate; ere ae in. (33/) or larger (ff).
7” Steak ) diameter 54, in. (28) or smaller (77).
oo. Ends rounded, dentate . . . et ies heh at) MARCHES

pp. About 14 times longer than wide; Pinetes aby to sha in. (33-50")
triplicatum 73; speciosum, 87
pp. About 4 longer than wide; diameter 74, to 34, in. (65-70),
supraspectosum, 88
pp. About 4 longer than wide; diameter =}, in. (50,4),
pychnochondrum, 89
rr. Diameter 545 to zsk5 ious ends 4 crenate, sides 4-6 crenate,
subcrenatum, 84.
4 atav tO zalxy (20- sa sides nearly straight,
Kyjelimanii, 87
PF Rue tear tO zeow (14-25); granules not radiate; end 4crenate,
, Blyttit, 87

ss. Marginal teeth numerous, long, pointed oraculeate, Zloiseanum, 85
SS. - 17, emarginate-truncate . . . . .guadrifarium, 87
ss. Margins crenate (ZZ).

#t, Basal inflation granulate in vertical lines (wz).

Pegi «with scattered granules . . . pseudopectinoides, 89
ald e without granules, the marginal in 8 radiating lines,

nasutum, 89

uu. Sinus widening outwardly; granules geminate in rows,
Aoteuconss 88
uu ‘ not widening outwardly; cell oblong, diameter 1, (33),
pulcherrimum, 9o
ass bs 2 cell orbicular, diameter =1, (50),
radiosum, go
vv. End truncate (wz).
vv. End not truncate (22).
ww, Diameter 34, in. (50) or larger (x2).
ww, Diameter smaller than (50/4), -4, in. (yy).

*Journ. R. Micr. Soc., Dec., 1885.

94 SPECIES OF DESMIDS.

xx, Sides granulate, ohne. the ends; semi-cell twice longer
than wide: <9... . . protractum, 83

xx. Sides granulate, ends concave; semi- cell twine wider than long,
biretum var. Floridense.*

xx. Sides crenate-undulate, converging; cytioderm verrucose,

Quasillus, 84
xx. “ rounded, acutely toothed, ends usually nude; cell as long
a5 Wide 2 Eo T a eG RPEIIORSS. Sete
nah straight, diverging, verrucose; aunte rounded, Jdretum, 86

yy. Cytioderm granulate; cell widest at base, sides converging,
sportella, 83
YY. a cell narrowed at base, sides straight, diverging,
protuberans, 84
yy. Cytioderm verrucose; end more or less protruding and scolloped
(4-crenate) 35°’, ei OCISIRE
yy. Cytioderm verrucose; ee more or tess seabraiiinn: not acollaned
ornatum, 82; protractum, 82
yy. es ” end not protruding; semi- cell twice as long
as wide, oblong-quadrangular, angles rounded; Lvroomet, 86

zz. Cytioderm finely granulate or punctate; semi-cells triangular,

angles rounded, margins smooth . . . . . Turpinji, 158

22. Cyuederm verrucose; semi-cell subreniform, 3 times as wide as
LONG es . . commisurale, 83

2. : " semi-cell Bydacnidal: angles rounded, long,
tumidum, 75

2B. 3: ff semi-cell reniform, dangles denticulate, a
central inflation granulate ° . . . . . . subcruciforme*

18. .TETMEMORUS. Fic. 18.

§ Cytioderm smooth or very indistinctly punctate (c).

§ Cytioderm punctate (a).

a. Cell 3 times as long as Diet irregularly granular; base slightly
phcate 5. oa! oS erengeeas; G2

a. Cell more than 3 ie as Jone as wale (0).

6. Front and lateral views fusiform; end with colorless, lip-like pro-

section: | s+: a . . granulatus, 91
6. Front view eyhadacal, not ‘aherine: aides view fusiform, tapering;
end rounded: oo ee ee iat a ee

* F.—w. Alge, p. 27 ef seg.

Shee

Se ee

eae oie

SS YY RRR MM

SPECIES OF DESMIDS. 95

. Three times longer than wide, smooth; diameter 554, to =4>
($B eof) oy ca cee eg ea Mantes, Ox
. Four times longer than wide, leach: diameter of (484); linear
elliptical, nolip . . . . . pentoides,*
. Four to six times longer than we: Gecath. or indistinttly punc-
tate; front view tapering, lateral fusiform, ;,1,, toz,ky (20-22),
levis, 91
19. XANTHIDIUM. FIG. 19.
Spines divided atthe ends... . Seg es. LOIRE GS
Spines subulate, ends not divided oe
Spines more or less scattered, numerous . . . aculeatum, 92
$6 ag sf ra 4 within the margins, Columbianum'**
. Spines marginal (4).
. Basal angles with 2 spines (@).
és ” i. I spine (c).
. Other spines geminate in 4 pairs. . ee cristatum, 93
s - i in 2 pairs on the ene single on the sides,
asteptum, 93
if not geminate, single on theends . . Torreyi.**

. Other spines 6 to 10 pairs on semi-cell; protuberance beaded,

bisenarium, 93

. Other spines 2 to 4 pairs (e).
“s rN an ge gir rae OPE Ce RET Ole, (OS
Other spines, 4 pairs, terminal . . . . . . . fasciculatum, 93
a “¢ 2 pairs, basal, vertjcal . . . . rectocornutum, 94
ee ‘« 2 pairs, terminal; a row of granules above the cen-

tral projection, a spine above the granules, J/tnneapoliense, 94

. Other spines, 2 pairs, terminal; a row of granules above the cen-

tral projection, no spine above the granules . polymazum, 94

. Other spines, 2 pairs, terminal, no granules above the projection

: (/).

. Diameter 74, in. (55-654) or more, Zylerianum+, fasciculatum, 93

as shy in. (50) or less; semi-cell truncate-triangular,
— asteptum, 93
- ds . semi-cell not truncate-triangular,
antilopeum, 94
*Journ. R. Micr., Soc., Feb., 1886.

**F, W. Alge, p. 34 et seq.
¢Journ. R. Micr. Soc., Dec., 1885.

96

§
§

a.
a. Semi-cell with more than 2 spines (¢).
6, Cytioderm with deciduous spines. . . SASS ocaey Cae ane
4. " verrucose in rows, margins cheouen . guadridens, 96
b. ig “ « ends alone crenate, xotochondrus.**
¢. Spines on the same side diverging (e).
m # be parallel (g).
ra * . converging See es OCR S Oe
ad. Margin of semi-cell angular, each angle with 1 or two spines,
octocornis, 97
e. End truncate; spines widely divergent . . .. . . Juncus, 97
e. End convex; spines moderately divergent (/).
J+ Piameter of cell che (40M) Geo a aaa
es : shyt (30-35) « . e..) CSubulatus, 96
i +" FE praia CAMOIE) digs iste 5 aetna: ere iets an an
g. Nuclei, 2 in each oblong-oval semi-cell . . . . . fragilis, 95
g. Nuclei none; semi-cell oval, diameter z5/55 in. (20) . ovalis, 96
g: #5 semi-cell orbicular, diameter 574, (12),
orbicularts 96
r¢ semi-cell elliptical; spines often very short,
convergens Var., 95
g. 7 semi-cell triangular, sinus wide, isthmus cylindrical,
triangularis, 36**
21, EUASTRUM, FIG, 21.
§ End lobe evidently distinct (a).
§ End lobe evidently not distinct (6).
a. End lobe deeply notched (c).
a. End lobe more or less concave or sometimes convex (g.)
6. End deeply notched (e).
é. End more or less convex; semi-cell with 7 or 8 lateral, short, coni-
CHUTOCER a ieee og A REE 104
End more or less convex; ace pe ioe ‘teeth ‘130 2 DERSME, AOe

SPECIES OF DESMIDS.
20. ARTHRODESMUS, FIG. 20, a, 0.

Cytioderm smooth (a).
Cytioderm verrucose or spinous (4).
Semi-cell with 2 spines (c).

Margins smooth (d.)

. Margins more or less spinous or beaded (/).

Margins dentate (2).

*Journ. R. Micr. Soc., Feb., 1886.
**F, W. Alge, p. 34 ef seg.

SPECIES OF DESMIDS, 97

d. Basal lobe deeply notched; basal /odule broadly marginate; central

WARUIE ODTSUC 5 ew ee ab hlobatym, 98
d, Basal lobe undulate (7).
a, «¢ rounded or angular (/),
e. Margins smooth (A).
é. cuspidate, spinulose or beaded (7).
j. Basal lobe undulate (zw).
Be " rounded or angular (2).
g. Margins smooth (7)
| ees cuspidate, spinulose or beaded (7).
A. End lobes horizontal; diam. 45-504 . . . Wordstedtianum, 105
| bE it “5 diam. 35-409 . . . . . . Spinosum, 106
(Aiea P Uprignt, Civerging 3 4 formosum,; 103
z. Basal lobes deeply notched (4).
rz . undulate (z).

j. Cytioderm rough with conic granules; semi-cells with one large
central inflation, a smaller one on each side, two on end lobe,
verrucosum, 100

@, Basal lobes undulate (cc).

R, $ rounded or angular (ee).
7. A short spine on the angles of end and basal lobes divaricatum, 104
/, A small projection on each side near the apex . compactum, 107

m, Cytioderm more or less tuberculate (7).

m. 5 punctate (9).

m. smooth (7).

Beweuoercies basal, mostly 5 sl eo ow Creare, 101
nt. - R Conta A Marval | Gee So Bae, TOG
2. ie: scattered; end lobe with a tooth on each side,

| ornithocephalum, *
0. Semi-cell 5-lobed, basal lobe emarginate, the lateral small, entire,
pinnatum, 98

0. . not 5-lobed (/).

p. Basal lobe with 1 lateral, subcentral tubercle, not emarginate,
ampullaceum, 100

p. Basal lobe without lateral tubercle, slightly emarginate, affine, 100

p.: . s vs . not emarginate; diam. 22-25 p,
adidelta, 99
p. ‘« “not emarginate; diam. 60-694 . . . wentricosum, **

*Journ. R. Micr. Soc., Feb., 1886.

98 SPECIES OF DESMIDS.

vy. Semi-cell subrectangular, basal lobe very broad, end lobe partly in-

cluded ‘between: the: lateral. . 50°. Moos. ehessam OF
vr. Semi-cell more or less pyramidal (s).
s. Diameter 4, in. or more (50-55). . . . . : Ewuerettense, 102

s. Diameter less then 54, in.; apical angles acute,
* Porkornyanum, 104; erosum, 104
s. Diameter less than in.; apical angles rounded . elegans, 106
¢, End lobe ona long slender neck; basal lobe with 6 protuberances,
mammillosum, 102
ALE Suen vane Fe “« basal lobe without protuberances,
insigne, 102
¢, End lobe not on a long neck (z).
uw. Basal lobe much wider than end lobe (z).
tu. ‘ scarcely wider; diameter less than x4, in. (42)
stmplex, 106
. Basal sinus narrow, basal lobes approximate (f)
és wide, basal lobes widely separated . tutermedium, 102
Diameter 51, in, (1004) . . . . . . . . . magnificum, **

v
v

as less than in.; no pits on the surface

250 p ’

ansatum, 99; purum, **

Ww

Ww

° « «4 pits on semi-cell . scrobiculatum, **

. End lobe beaded: angles of basal lobes beaded. ventricosum, 160
* dentate; angles of basal lobes dentate . simplex, 106

Ww. sy smooth, its angles spinous orcuspidate. rostratum, 106
x. Angles of end lobe and margins of basal each with 3 diverging spines,
cuspidatum, 105

s “ with short a margins of basal dentate or
Sranvlate os iki, delta a ik OIE Sears

. Angles of end lobe gin one dauh orspine. . . . vrostratum 106
. Basal and central lobules both slightly emarginate, oblongum, 98
. Basal lobes slightly emarginate, central obtuse, multilobatum, 98

. End lobe columnar, margins nearly parallel, end truncate,
attenuatum, 103

z. End lobe not columnar, partly included between the lateral lobes,
oblongum, 98

8

n eS eS &

z. aE ss not included (aa).
aa, Cell 2-3 times longer than broad; diameter 54, in. (75,4),
humerosum, 99

aa, Cell about twice longer than broad, diameter 45, in. (14),
Lundellit,
aa, ‘s 4s a - diameter 4, in. (75),

pectinatum.**
** F -W. Algz, p. 36 et. seq.

SPECIES OF DESMIDS. 99

aa, Cell % or less longer than broad (0d).

66. Semi-cells urn-shaped; diameter s4, in. (50) . urnaforme, too
bb. - more or less quadrate; basal lobes horizontal, emargin-
ate; protuberances minutely granulate. . . gemmatum, 101

66. Semi-cells more or less pyramidal, basal lobes emarginate,

. insulare, 104

cc. Angles of end lobe acute cid as an A MANS.” LOG
CC. és " rounded or Benue (id).
dd. Diameter 1, to ~h, in (32-38). . «1... Omerme, 104
dd. i qo in. (144); length 51, (281) + + erassicollé, 105
dd. “ ass tO qolgy in. (20-22); length 51, (28),

compactum, 107
ee. Angles of end lobe acute (/*).
ee - F obtuse or rounded (gg).
ff. End notch broad, gaping, the apices upright . . . dbinale, 107
fF os narrow, Close, the apices horizontal . . simplex, 106

gg. End broadly rounded, continuous with the sides; diameter jh,
2 GAL) oe ie: | 0btesamys 104
s i 5 : <6 semi-cells wedge-
shaped; diam. 24-28 é . cuneatum,**
gg. End elevated above the sides, a small Breeton near the apex on
PROMI sy ee ee ale 8h COMPACLME, 107

. End elevated, no Pion peaiebtiod: Da aca eae BOR

22. MICRASTERIAS, FIG, 22. FIVE FORMS.

Cell more or less circular (1).
Cell oblong (2).
End lobe narrow, lengthened into divergent arms (a).
‘ ‘3 not lengthened into arms, semi-cells 5-lobed (4).
End lobe broad, not lengthened into arms (c).
Semi-cell 5-lobed, lobes horizontal; end lobe with 4 arms (¢).
£3 ef 2 vs end lobe with 2 arms (2).
Hy s lobes not horizontal, approximate; no arms (aa).
. Semi- cell 3-lobed, lobes horizontal; end lobe with 4 arms (¢).
be ag - “s end lobe without arms (/).
Semi-cell 5-lobed (4).
. 3-lobed, lobes radiate (/).
“Rad lobe not or slightly exserted (¢).
" conspicuously exserted (7).

SSR RNY NN NN FH HOD

100 SPECIES OF DESMIDS.

c. Semi-cells 5-lobed (7).
c. Semi-cells 3 or obscurely 5-lobed; lateral sinus shallow, obtuse;

lateral angles mucronate . . . . . . . decemdentata, 113
d. Basal lobes with 3 linear processes on each side . muricata, 118
d. . without linear processes, but (e).
e. Forked once only, margins finely serrate, Mahabuleshwarensis, 112
é. " ‘“‘ margins and surface spinous . . . spinosa.**™
A tf * “margins smooth . . . . Wordstedtiana, 113
e. Forked twice (lobules forked); cytioderm spinous . . sfinosa.*
é. ‘6 cytioderm smooth; margins serrate, Hermanniana, 112
é. ss re ~ margins not serrate, Americana, 112
jf. End lobe nearly as wide as the basal, apices deeply notched (g).
if a 3 s me s apices not deeply notched (Z).
jf. End lobe much narrower than the basal, end convex, oscttans, 116
be “ is . - é *« end deeply emarginate,
foliacea, 118
ve e ad See ei “« end slightly concave,
Rabenhorstit.**
g. Basal lobes furcate (with lobules), (7)
&. zs not furcate (7). :
Ah. End lobe convex, without prominences . . . . . J/aticeps, 115
h. ‘4 truncate, with 2small prominences . . . . recta, 112
h. retuse, basal lobe furcate . . . . . . Bailey, 118
z, " with 2 slender, transverse, bidentate projections,

3 guadrata, 117
z. End lobe without projections, convex; sinuses broadly rounded,
Kitchellit, 116

e * without projections, concave; neck short; sinuses acut-
isha PS oo ial ROT OnE. tee
z. oy * és " neck long; basal lobes

curved Upwards 6 0064 so ieee en ca a oe
Jj. Basal lobeshorizontal, not curved . . . . . jpinnatifida, 116
Le e curved upward, narrow,

expansa, 117; arcuata, 117; simplex.* |
k, Basal and lateral lobes deeply furcate (with lobules), furcata, 111

R, “i <n “shallowly furcate, surface smooth, (4)

Rk. % % o 9 ‘“* surface spinous; diam.,
175-200QM 65 2. . . apiculata.**

h. " es not furcate 402.75 fy ee III

* Journ. R. Micr. Soc., Dec. 1885.
** Fw. Alge, p. 36 ef seg.

SPECIES OF DESMIDS, IOI

“ Lateral and basal lobes separated by adeep acute notch,
Crux-Militensis, 111%
“ Lateral and basal lobes separated by a shallow rounded notch,
spectosa,**

Z, Lobules deeply furcate; borders not serrate . . . dichotoma, 111
Hi - not furcate, borders not serrate . . . . vringens, 112
‘ e u DOractS serrate 3 Sn serrata

. End lobe remote from the lateral (x).
m, End lobe not remote from the lateral (0).

Me ae erlane ula ie ee hg Ertangularts, 48
2. - not triangular. . 4 8, Ramata, 114
o. Lobes closely approximate, radiating (p).
0. Mi es - not radiating, end lobe truncate,
truncata, 114
emer We CianeUlar 3 ee ae Priangelarts, 115
p - CApeate, Gnd CONCAVE (5 ee ee conf Orta AT4
p. ty very broad, end truncate or convex . . . crenata, 113
PMG DADINORS 6 ey oe ah epeemdala, “F10
r % not papillose (s).
s. Basal lobes with 4 subdivisions, lateral with 8; apices of end lobe
TURNS Nip tae ee MEL gy POLED, PIMOTUAAE, “109
S. " 4 “4 cats Oe apices of end lobe
ROE Turcate 0) gs a COP MME.
s. Basal lobes with 2 subdivisions, lateral with 4 Gy:
s. Basal and lateral lobes with the same number of subdivision (7).
¢. End lobe with 1 row of pearly granules . . . . Minnesotensis.t
is e without pearly granules (y ). |
wu. End lobe exserted onalong neck .. . . . brachyptera, 110
ut, ve exserted without long neck, its apices furcate, s¢mplex, 110
Se aee tse SDIDOUS ee aes ia eracApplera, 110
v. 4 not spinous . . . poe tg hi es) ORSON AEA.
y. Sinuses deep, inwardly witenen sia rounded: subdivisions of
semi-cell 20-40; surface smooth . . . . . ~radiosa, 109

y. Sinuses deep, inwardly rounded, surface with rounded elevations,
mamillata.**

z, Lateral lobe deeply furcate; basal part Cherie furcations
horizontal; ends bifid .. . . . eae ee

aa, A row of éentfally larger basal inflations across each semi-cell,
verrucosa.**

aa. No basal inflations; minutely granulate . . . . /enneri, 115

** F.—w Algz, p. 38 ef seg.
+ Journ. R. Micr. Soc., Dec. 1885.

102 SPECIES OF DESMIDS.

23. STAURASTRUM. FIG. 23. FOUR FORMS,

4 With numerous processes, their ends more or less divided (§ §)
{ Without processes, the angles infront view produced or not (§)
§ Cytioderm smooth or finely punctate (1).
§ Cytioderm verrucose or granulate (2).
§ Cytioderm hirsute, spinulose or thorny (3).
End view 2-armed, body pia ovate; arms serrate, apices
finely toothed .. . . A CoS sree ae ene idee
End view 3 or 4 angled (B).
End view 5 or 6-angled, apices of (6) rays rounded and spinulose,
Kissimmense.*
ss 5 angled, apices spinous (G).
End view 6-angled, apices of cylindrical processes slightly
notched, 4 processes within the margin; end view hexagonal,
Wolleanum.*
§§ =f " apices of (5-6) rays trifid, distended,
distentum, 149
§§ End view 8-angled; rays a whorl of 8 below, 4 above,
S§
§§

§§
S§
S§
S§
S§

tetroctocerum, 151
End view circular, rays a whorl of 9 below, 6 above, artiscon, 148
ne A rays marginal, very short, usually 9, ends notched,
Liloiseanum, 149
1. Angles of semi-cell in front view not produced; rounded and
smooth (a).
I. ws is 7 eS #1 mucronate, spi-
ous or notched (c).
Angles of semi-cell in front view produced more or less (2).
Angles of semi-cell in front view more or less produced (2).
ee re * s - not produced (gg).
Angles of semi-cell in front view more or less produced (00).
- : “a ss - not produced (yy).
Semi-cell oval or elliptical, ends not inflated (4).
y . % ends inflated; diam. , gh, in. (25,4),
bacillare.*
Semi cell semi-circular, smooth, sinus narrow, linear, ordiculare, 120
Semi- cell almost circular, sides finely dentate . . Cosmarioides.*
” es sides smooth . . . . . wesiculatum,*
Semi-cell triangular, sides concave . . . . . . éthedrale, 123
Semi-cell cuneate; cell slightly longer than wide,
pseudopachyrhynchum, 125

RAH NH

RAR RARA

*F.-w Alge, p. 41 ef seg.

{
q
q

ks aa 5 ii Cees te.

SPECIES OF DESMIDS. 103

Diameter 60-1124 (zh, to gh, in.) (8).
& 32 (ky in.); granulate-crenate . . . . . Juteolum.*

$s 13-1644 (x1,y to z44, in.),

mulicum, minor, 119; Bieneanum, 124

. Sides slightly constricted near the angles, especially in end-view,

tumidum, 120

. Sides not constructed; diameter 54, to z4, in. (75-83,),

grande, 120
s ‘ diameter z}, in. (60) . . . imerme 122
Angles mucronate (¢).

Angles aculeate, spinous, awned or notched (e).

. Mucros double on basal angles, none on the end in front view;

semi-cells truncated triangles . . . . . pantculosum, 124

. Mucros single on all angles, horizontal; diameter less than 34, in.

(50); semi-cells not quadrangular... brevispina, 121

. Mucros single on all angles, horizontal; semi-cells quadrangular,

guadrangulare, 145

. Mucros single on all angles, diameter larger than z4, (50),

magnum, 120

. Mucros single, oblique downward and inward; diameter 54,

(10cof) Or more. . - « + mazgusculum, 121
. Mucros single, oblique Downward ana outward; diameter zs}, _
fagityOr less. coco, RU, ee an cow ae, Dag
. Aculei or awns 1 on each angie (/).
. 2 on each angle (g).
f 3 on each angle (zz).
ff 40r more on each angle (ww).

. Semi-cells elliptical, often angular, approximate; ends straight,

concave or convex; awns horizontal, diverging, converging or
upwardly oblique; diameter ;4, to zap in. (25-38),
dejectum, 121

ca ae diameter z+, to qh, (55-60), cornutum.*

. Semi-cells elliptical, separated by along, narrow isthmus,

cuspidatum, 123
. ioarian nyt uci awns long; diameter z=}; to zhq_
(50-57) . . . . . megacanthum, 121

. Semi-cells triangular; sinus with a hall dnt on each side,

Lewisit, 122
* “« sinus without a spine . . ar¢stifcrum, 122
Soe cell quadrangular, margins toothed or spinous,
guadrangulare, 145
*F .-w. Alge, pe 4I.

104 SPECIES OF DESMIDS.,

Angles in end viewtrifid . . ., Pun So eee ee
2 A *¢ simple or bifid oy
Arms trifid or bifid; end view 3-4 radiate; arms smooth, .
jrdchistad 124
A. 4 3 e end view 3-radiate; arms aculeate, rough,
aspinosum, 143
bd end view 5-6 radiate . . . distentum, 149
A. s¢ * = end view 7-9 radiate . . . . Rotula, 135
Arms truncate, oblique, geniculate, short; end view 4-radiate,
inconsplcuum, 125
. Arms acute or aculeate, curved; end view3-radiate . sudeticum.*
Ends separated by a more or less elongated isthmus (7).
Ends approximate (z).
End view fusiform, with a central obtuse inflation, Zeptocladum, 136
Me oval, a long arm on each side,
grallatorium, 136; ungulatum, 136

oO
3s:

§:
h.

.
~
nw
“
~

»

BODO ROM.

j. End view triangular or 3-radiate (4).

fi 5 quadrangular or 4-radiate (/ ).

of 5-radiate (v).

J: ‘5 6-radiate (z’).

i ee 7—-8radiate . ... i vnp? ata iat ee

Rk, Isthmus basally inflated; irene or shins (2).

R, : not basally iinfideed cuspidate not spinous (72).

7, Isthmus basally inflated . . . . . . . elongatum, 130

Z. with a 1-4 fe oan protuberance on each side; arms
SORE As oie cy . fasciculoides, 130

Z. ¥ with 1 notched spine on sack Hae . . . Spinosum, 139

m, Diameter 4, in. (50/4) or less (7). !

m. vy zy in. (60) or wider (2).

n. End straightish, sides tapering into short, mostly obtuse processes,

tricorne, 126
a. End broadly convex; processes curved . . . . cyrtocerum, 128
n. ve oe processes straight, slender . . gracile, 133

o. In end view the angles produced in long arms,
vestitum, 138; pseudosebaldi, 139
In end view the angles not produced in long armss Sedaldt, 138
Isthmus basally inflated or cuspidate (7).
Isthmus not basally inflated nor cuspidate (s).
Isthmus basally inflated, corrugated and denticulate, tetragonum, 130
- witha short spine on each side . . . odontatum, 134

XX D'PS

*Journ. R. Micr. Soc., Dec., ’85.

SPECIES OF DESMIDS. 105

s. Diameter ,1, in. (314) or smaller (2).

‘“ ate in. (604) or longer (w).

t. End straight, sides RAPES into short, mostly obtuse processes,

i ee oS

8

RR N NA

tricorne, 126
End convex; processes short, stout . . . . . crenulatum, 126

End concave; processes short, upwardly diverging,
pustlinm, 130; Donnellit; 132

. Processes short, robust, incurved; end of semi-cell truncate,

cerastes, 133
ze long, narrow, incurved; end of semi-cell convex,
ankyrotdes, 137

_. Processes lone. horizontal 6. eS . helracerum, 134
. Processes curved, apices bifid . . . . . . pentacladum,.129
0 ” APNGCOR COE 2 i's 3 len SRCUUM, 132

Processes horizontally radiating; ends of cell mith bifid papille,
pentacerum, 134

. Processes horizontally radiating; ends without papille,

crenulatum, 126

. Processes upwardly diverging, the apices bifid . franconium, 131
. Diameter 7}, in. (40) or smaller (x).

“sho in. (70H) or larger (y).

. Isthmus centrally ribbed; rays curved downward . comptum, 129
not ribbed; in end view rays basally separated by an
acute incision . . . ae MSU, 132

. Isthmus not ribbed; in eee view tans Geared by a rounded

sinus Rng ie ty . . ¢crenulatum, 126

End with Si ae Rene pe ey to 4, In. (140-1504),
Ophiura, 134

End with prominent papillae; diameter 54; to 34, in. (75-85),
coronulatum, 135

. End without prominent papille; ray margins serrate,

macrocerum, 134
6 ““ ‘“ ray margins granulate-crenate,
hexacerum, 137

. End view oval, ends produced in along, thin arm, uagulatum, 136

" PSOE Ty 5s eee a ia tee rye cen eke: ustforme, 1
» 13

. End view triangular or 3-radiate (aa).

7 4-radiate or angular (ee).
e 5-radiate (7)

106 SPECIES OF DESMIDS.

aa. Apices of rays obtuse; diameter 4, to hy in. (40-50),
arachne, 129

aa, s - diameter z5i5 to apy in. (15-20),

totanum, 137
aa, Apices of rays not obtuse (40).

62, End of cell in front view papillose or verrucose (cc).

bb. Re " 7 “not papillose nor verrucose (da).
cc. Diameter ~4, in. (36) or smaller, arcuatum, 130; subarcuatum, 140
ce. : sty to zh, in. (60-804); arms diverging, anatinum, 139
dd, End view, sides straight, angles 3-4 spinous,, polymorphum, 126
dd. sh sides concave; arms long, straight, in front view di-
Verein oc, . . paradoxum, 129
dd, End view, sides concave; arms ahons Fipietionse 131; manum, 138
ad, ey sides convex; arms short, tumid at base, He/eanum, 133

ee. Apices of arms inconspicuosly bifid or trifid,

Haabeliense, 131; paradoxum, 129
ee. Apices of arms prominently and deeply trifid . . . Osceolense.*
ff. Apices of arms obtuse; the arms mere lobes, very short,

stlatatum, 128
Ff. * " “arms long, narrow. . . . arachne, 129
ff. Apices of arms bifid; front view end with a crown of papille,
Floridense, 135
ff. Apices of arms bifid; front view iia without papille,
pentacladum, 136

gg. End view 4, 5, 6, or 7-angular or radiate (Z/).
gg. End view triangular (77).

hh. Cytioderm rough with pearly. granules; rays 4-7, short, obtuse,
margaritaceum, 125

hh. 4g granulate; end view 4-6 angled, sides straight,
Meriani, 132
hh. ve ‘* end view 4 angled, angles with 2 spines,
Nove Cesaree, 145
hh. a i end view 4-5 angled, sides concave, angles
without spines 09 40003 ja RRO es ea ee

zz. Angles in front view notched or otherwise divided (j7).
zz, Angles entire (££).
*Bulletin Torrey Botanical Club, Dec. 1885.

SPECIES OF DESMIDS. 107

jj. Surface granules emarginate or divided; semi-cells broadly elliptical,
asperum, 127

J): “ not emarginate; semi-cells elliptic, ‘¢uncata, 128

Hf. - not emarginate; semi-cells subsemiorbicular,
angles truncate . . . pei et. MEP RMEME, 329

jj. Surface scabrous, semi-cells pihiatic Dae ae | ce), SOI, BAG

Jj. Surface tuberculate; sides at base convex, spinous; a central,
spherical, spinous projection conspicuous’ . . . dullosum.*

jj. Surface tuberculate; sides at base concave; no central protuber-

| ance 2 oe.» tberculatgan®

i se e ee as not concave, pseudocrenatum.**

kk, End view sides concave (//).

Rk, ck sides nearly straight, very slightly convex (wz).

Rk, . sides convex; semi-cells subsemiorbicular,

muricatum, 127
4. Semi-cells twisted; 2-3 times longer than wide, elliptic or oblong,
alternans, 128
7. Semi-cells not twisted (mm).
mm, Front view ends concave; end view angles rounded,
striolatum, 126
mm. 4 % end view anglesacute, /Pringlei, 132

mm. Front view ends convex; end view angles crenate, sides smooth,
crenalum, 126

mm. ¥ ee end view angles not crenate, somewhat
SrUnGhte (re PO a at RRL EEER, RID.

mm, s " ee view w angles granulate, rounded,
| erasum,**
nn, Diameter zj55 in. (25) orless . . . . . pygmeum, 128
nn. ss greater than 5,5, in. (25,4); end broadly truncate,

sides slightly convex or nearly straight, converging,
botrophilum, 131

nn, Diameter greater than 74,5 in. (25,4); end rounded, sides convex;

semi-cell elliptic . . . . vrugulosum, 127; punctulatum, 127
oo. End view 3-radiate or angular, sides nearly straight (ff).
00. a : ss sides concave (77).
oo. End view 4-radiate or angular (x2).
pp. Cells spinuloseon the whole surface . ... . aculeatum, 140
pp. n onthe margins only ... . ._ seligerum, 141

*Journ. R. Micr. Soc., Feb. 1886.
**F -w. Alge, p. 42 e¢ seg.

108 SPECIES OF DESMIDS.

rr. Cells spinulose, a short, irregular process on each side,
controversum, 143
rr. Cells spinulose on the margins of the long, colorless, diverging

BUONBS ee ee to oe ao pa oO
ss End view triangular or 3-radiate (wz).
SS. . 4 or 5-angular or radiate (7¢).
ss. End view circular, with usually 9 short, marginal, notched pro-
CORES ey Pied pk he oie Sie ae eps ee
tt, End view margins smooth; spines short; semi-cells in front view
twice as wide aslong. . - as. C0tCtla, 122
tt, End view margins smooth; ae shorts semi- ‘celles in front view 3,
‘or 4timesaswideaslong . . . . . commutatum, 124

tt. End view margins smooth; spines on ‘his angles only, very long,
longispinum, 145.
tt. _ ae on the ate and surface as well as on
the angles 2... aes Sri Minnesotense.**

#t, End view margins verrucose, the verruce emarginate or not,
: forficulatum, 144
tt. ns «« denate, angles usually 3 . monticulosum, 144

uu, End view margins smooth, concave; angles notched,

guadrangulare, 145,

uu. - ‘““ _crenate; spines long, divergent,
Nove Cesaree, 145,
uu. ff ‘‘ spinous; angles produced, furcate,

forficulatum, 144

vv. End view triangular; aculei short, Wystrix, 142; tridentiferum, 142
UU. i - spines long, colorless,

tricornutum, 145; triguetrum,**

vv. End view angie, rae hg rounded, spines scattered;

sides concave... ieee, oe in ea: ae

. End view 5-angled, sides concave . . . . . SBrasiliense, 146

ww. Angles with numerous sete as long as the lobes; cells in front
view cruciform. . . pe crucitatum, 142

ww. Angles with 4 teeth, 2 draiecine toswind, 2 downward,
cerberus, 142
WW. -2 spines; margins concave, spinous
guaternium, 144
xx. Sides unequally produced, spinulose or spinous, controversum, 143
xx, Sides equally produced, spineless; angles spinous aculeatum, 140

**F —w Algee, p. 41 ef seq.

18S.

XS

mb & & wodedoe AR

Se Se eS

SPECIES OF DESMIDS. 10g

. Diameter z4, in. (38/4) or less (22).
. Diameter greater than (38) ;4, inch (4).

Cytioderm aculeated, aculei larger and denser at the angles,
teliferum, 140
. Cytioderm aculeated oie at the centre, echinatum, 141; pecten, 141

| spinous; margins dentate oda a a ERE:

ce margins crenate ... . . Ravenellit, 143
. Cytioderm aculeated, aculei geminate ... . sociatum, 142
se 1“ aculei not geminate, densest at.the angles,
Brebissonnit, 141
ie aculei evenly covering the surface,
Saxonicum, 1413; hirsutum, 141
Cytioderm spinous, spines not notched .. . echinatum, 141
Le ‘¢ spines or short processes notched,
spongiosum, 148
. End view 3-angled; processes within the margin, 6 in number (C).
““ ““ ‘< ‘<“ “é ‘< 3 in number (D).
Ve i ‘i processes both on and within the margins (7).
* * 3 processes at the angles only (£).
End view 3-angled, angles broadly truncate, each with 3 promi-
nences . . . .xiphidiophorum,**
met Aa tk : es each with 2 promi-
Nences «...: ers stmplex,**
End view 4- Saeled. badly fe dronealae: nee of arms trifid,
Osceolense.**
. End view 3 or 4-lobed, eae or bifid; cell very irregular or

Gnadtate 47°.) sha CMOr me, ES%
Front view lateral nace crenate; betas margins crenate,
eustephanum, 147

S lateral margins smooth . . . pseudofurcigerum, 147

39 lateral margins with 3-6 sharp teeth; basal margin
cee i ee oes yee os eae Cc a ae ae

. Cytioderm granular . . . . . furcigerum, 146

. Cytioderm smooth; end view Silo srcduord into 2 processes, a

third above and betweenthem ..... . . Pottsti, 151

. Cytioderm smooth or finely punctate; end view angles notched,

Kittchellit, 150
Processes 9, nearly as long as semi-cell diameter, ends furcate,
Tohopekaligense.**

*Jour. R. Micr. Soc., Feb., 1886.
**F W. Algee, p. 41 et seg.

SY 2 Rs er a ae

SPECIES OF DESMIDS,

Processes shorter than semi-cell diameter, ends furcate,
furcatum, 15°
Processes 6, short, notched; semi-cell rectangular, twice wider
than Long i ee ee tree te a
End view central radiating processes 6; marginal, including
angles, 9, senartam, 147
central ae srargiwal Sailes short numerous, notched,
spongtosum, 148

Semi-cells saucer-shaped, eter with 5 divergent spines,

calyxotdes .*

*F —w. Alge, p. 46.

GLOSSARY.

Aculeaie: having one or more sharp points or prickles.

Acuminate: ending in a sharp point.

Antheridium, plural Antheridia: certain reproductive organs supposed
to have the function of the anthers of higher plants.

Annulate: ringed, marked with rings.

Articulate: jointed, formed of joints.

4i.; in compound woods, meaning two or twice.
Lidentate: with two teeth or tooth-like projections,
Bifurcate: forked, separating into two branches or parts.
Bullate: blistered or puckered.

Cenobium: a community of individual cells united in one body or
cluster. ;

Connate: united at base, as two opposite branches around the stem.

Costa, plural Coste: a rib.

Costate: ribbed.

Crenate: scolloped.

Crenulate: with small scollops.

Crescentic: crescent-shaped, like the new moon.

Cructform: cross-shaped. :

Cuneate: wedge-shaped.

Cuspidate: with ashort, stiff, sharp point.

Cytioderm: the membrane of the cell.

Decussate: in pairs alternately crossing.

Dentate: toothed.

Dichotomous: with the divisions in pairs; two forked.

Die«cious: having the male and female flowers on separate plants.
Dissepiment: a partition or division.

Dorsum: the back, here the back or curved portion of Closterium.

i12 GLOSSARY.

filiform: thread shaped, or thread-like.

Flexuose: bending in opposite directions.

Fusiform: spindle shaped, large in the middle and tapering to both
ends.

Geminate: twin, in pairs.

Geniculate: bent like a knee.

Gonidia: propagative bodies, not produced by any act of fertilization.
Granulate: with small or fine granules. |

Hirsute: hairy.
Hyaline: transparent as glass.
\

Impacted: matted, the whorls indistinct.

Lamellate, lamellose: formed of superposed layers or plates.
Lunate: crescent-shaped.

Mikron (pl): the szigy Of an inch.

Monecious: having the male and female organs separate but on the
same plant.

Moniliform: \ike a string of beads, or necklace-like.

Mucronate: tipped with a short, stiff point.

Nucleus, plural Vuclez: in this case, one or more collections of chloro-
phyll in the cell.

Obovate: egg-shaped, but with the broader end upward.
Oégonium, plural Odgonta: the sac bearing the odspores.
Odspore: spores formed in the ovarian sac or odgonium.
Orbicular: circular, or nearly so, in outline,

Pellucid: transparent.

Piliferous: bearing short hairs.

Plicate: folded.

Polymorphus: having several or many forms.

Pubescent: bearing fine, soft hairs.

Punctate: dotted with minute elevations or depressions.
Pyriform: pear-shaped. :

Ramulus, plural Ramuli: a small or secondary branch,
Reniform: kidney-shaped.

GLOSSARY. 113

' Saccate: sac-like, baggy.

Scabrous: rough.

Septate: with a partition.

Serrate: with saw-teeth, or teeth pointing forward.
Setiform: bristle-like.

Setigerous: bearing bristles or sete.

Sigmotd: s-shaped.

Sinus: the depression between two parts of a cell.
Spermatozoa: active, thread-like bodies in certain cells.
Spermogonia: cells which give rise to the spermatozoa.
Spinulose: bearing short spines or prickles.

Stipe: the stem or stalk..

Stipitate: with a short stem or stalk.

Stratum: a layer, anything spread out in a layer.
Sub.: in compound words, meaning less than.
Subulate: aw\-shaped.

Thallus: a mass of cells, consisting of one or more layers, often a
flat expansion.

Tortuous: irregularly curved, winding, twisted.

Truncate: as if cut off square at the end.

Tnberculose: with small rounded projections or tubercles.

Umbellate: the branches or parts beginning at the same point, like
the ribs of an umbrella.

Ventrum: in this case, the concave region of Clostertum.
Verruca, plural Verruce: rounded, wart-like elevations.

Whorl: ina circle round the stem.

ZLobspores: spores with active movements.

Anabeena
Anacystis
Aphanizomenon
Aphanocapsa
Aphanochete
Aphanothece
Apiocystis
Arthrodesmus
Asterothrix

Bambusina
Bangia |
Batrachospermum
Beggiotoa
Botrycoccus
Botrydium
Botrydina
Bulbochete

c

Calocylindrus
Calothrix
Cheetomorpha
Chzeetophora
Chamesiphon

INDEX.

Page.

Chantransia
Characium
Chlamydococcus
Chlamydomonas
Chroococcus
Chroolepus
Chytridium
Cladophora
Clathrocystis
Closterium

| Coelastrum
| Coelospherium

Coleochete
Campsopogon
Conferva

| Cosmarium
_ Craterospermum
~ Crenothrix

Cylindrocapsa
Cylindrospermum

D.

| Desmidium

| Dictyospherium
- Dimorphococcus
_ Docidium

_ Draparnaldia

116

E.

Enteromorpha
Eremosphera
Euastrum
Eudorina
Euglena

Genicularia
Gloeocapsa
Gloeocystis
Gloeothece
Gleeotrichia
Gomphospheria
Gonatonema
Gonatozygon
Gongrosira
Gonium

H.

Hapalosiphon
Hildebrantia
Hyalotheca
Hydrodictyon
Hydrurus

Introduction
Isactis

Lemanea
Leptothrix
Leptozosma
Lyngbya

M.

Mastigonema
Merismopedia
Mesocarpus
Mesotzenium

INDEX.
Page.
Micrasterias

43 Microcystis

55 Microcoleus

96 | Microthamnion

49 Mischococcus

50 | Mougeotia

N.

80 | Nephrocytium

73 Nodularia

é4 Nostoc

ly O.

6

: (EX dogonium

7? | Olpidium

62

8 Onychonema

1°) : :
Ophiocytium
44 | Oscillaria
50 scilla
P:

66 Palmella
Palmodactylon

38

80 Pandorina
Pediastrum

51 ‘

53 Penium
Petalonema
Phymatodocis

11 | Pithophora

63 Plagiospermum
Pleurocarpus
Plectonema

37 | Porphrydium

71 | Polycystis

81 Polyedrium

68 | Prasiola
Protococcus

63 R.

72 | Raphidium

62 Rhizoclonium

81 | Rivularia

Page.
99
72
69
44

55
61

54
68

66

38
55
81
52
70

54
53
-49
50
82
65
81
45
62
62
65
54
72
53
43
53

55
47
63

Scenedesmus
Schizogonium
Schizochlamys
Schizomeris
Sciadium
Scytonema
Sirogonium
Sirosiphon
Sorastrum
Spheeroplea
Spherozosma
Spherozyga
Spirogyra
Spirotenia
Spirillum
Spirulina
Staurastrum
Staurogenia
Staurospermum

Stephanosphera -

Stigeoclonium
Symphyosiphon
Symploca
Synechoccocus

INDEX,

Page.

51
47

nae

56,

45
52
64
61
65
51
42
81
68
58
82
72
72
102
51
62
50
43
64
69
72

Tetmemorus
Tetraspora
Thorea
Tolypothrix
Triploceras
Tuomeya

Ulothrix
Urococcus

Vaucheria
Volvox

Xanthidium

Zygnema
Zygogonium

48,’

49

61
61

Ze

Gi Gis oo,

oe Z Z La GB
yy

Y, tie tj
UY