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Introduction
Although convenient, the term algae has been applied to such a
great variety of plant groups and has been given so many interpreta-
tions that it has no very precise meaning. In the broadest sense it
may refer to all chlorophyll-bearing thallophytes and protista, and
their colorless close relatives. Life history studies have established
genetic relationships between definitely plant-like and animal-like
algae. Thus the incorporation of the Volvocales in the phylogeny of
the Chlorophyta is necessary. Other protozoa-like, pigmented
organisms, such as the Euglenophyta and the Cryptophyceae and
other Pyrrhophyta, are examples of evolutionary lines which appar-
ently have ended blindly in their present expressions. One might
contend, therefore, that their inclusion among the other definitely
plant-like algae cannot be justified because, unlike the Volvocales,
they have no phylogenetic connections with the group. Notwith-
standing the fact that the Euglenophyta and Pyrrhophyta include
some colorless and definitely protozoa-like relatives, the groups merit
a place in phycological study by virtue of their many plant-like at-
tributes. Likewise, chlorophyll-bearing, bacteria-like organisms must
be given a place in the broad definition of the Cyanophyta. Many of
the organisms belonging to the Chrysophyta have only a few char-
acteristics which entitle them to a place among the algae, but be-
cause the morphology and the habits of some members are funda-
mentally plant-like their inclusion is clearly justified.
Whatever limits of classification may be set up for the algae, all
these groups of simple organisms are interesting to the phycologist,
the aquatic biologist, the limnologist, and the oceanographer. In
order to meet a number of these interests and to make the present
work as useful as possible, the broader interpretation of the algae
has been adopted and representatives from the eight divisions are
treated here. (There are eight divisions, or phyla, if one recognizes
the Chloromonadineae. This little-known class is represented by
Gonyostomum semen Dies. in our collections.) Hardly any two phy-
cologists are in complete agreement on the disposition of forms with-
in the algal groups. The taxonomist will note, therefore, many
inconsistencies if the details of the arrangement used here are com-
pared with any one of the several schemes followed in handbooks,
[1]
floras, and in some monographic works. I have chosen to use familiar
names of long standing unless changes in such names have been
adopted in generally used monographic studies which are easily
obtainable for reference. For the most part I have followed the taxo-
nomy and nomenclature suggested by Pascher (1931) and employed
by Gilbert M. Smith (1938). The structure of the cell wall, the pig-
mentation, and the nature of food reserves have been used to unite
the Heterokontae, the Chrysophyceae, and the Bacillariophyceae to
form what seems to be a very natural division, the Chrysophyta.
This rearrangement reduces the number of groups previously recog-
nized among the algae. The colorless relatives of the motile algae
are not included here. The taxonomic arrangement employed, then,
takes the following plan:
Division I. Chlorophyta (Green Algae)
A. Chlorophyceae
B. Charophyceae
Division II. Chrysophyta (Yellow-green Algae )
A. Xanthophyceae (Heterokontae )
B. Chrysophyceae
C. Bacillariophyceae (Diatoms )
Division IJ. | Euglenophyta (Euglenoids )
Division IV. | Chloromonadophyta (Chloromonads )
Division V. Pyrrhophyta (Yellow-brown Algae )
A. Cryptophyceae
B. Desmokontae
C. Dinophyceae
Division VI. | Phaeophyta (Brown Algae, marine )
Division VII. | Cyanophyta (Blue-green Algae)
A. Myxophyceae
B. Chlorobacteriaceae
Division VIII. Rhodophyta (Red Algae, mostly marine)
In the following pages certain terms will be used frequently when
reference is made to the type of existence most characteristic of
a species. The name plankton, of course, refers to organisms which
[2]
have a drifting habit and includes all forms of both macro- and
microscopic life which float free in the water or, if motile, are un-
able to swim against currents. Open-water plankters are called
euplankton (true plankton). Many algal species existing as such
have elongations of the cell, or bear long spines, whereas others may
gain buoyancy through the possession of mucilage. There is evidence
that pseudovacuoles in the cells of many blue-green plankters aid in
this connection. Forms which are unattached but are caught among
filamentous algae and other vegetation and reproduce in shallow
water are called tychoplankton. The minute phytoplankters which
pass through the meshes of a fine (No. 20) bolting-cloth collecting
net are here termed nannoplankton. A special term, periphyton, may
be applied to the organisms which form associations on the stems
and leaves of aquatic plants. Benthic algae, benthos, are the organ-
isms which live on the bottom especially in deep water, for ex-
ample, Chara, Nitella, Dichotomosiphon, and some species of
Cladophora.
[3]
Geological Features and
Algal Distribution
Some species of aquatic plants may have a wider geographical dis-
tribution than terrestrial forms. This is true, for the most part,
because of the more nearly universal similarity of aquatic habitats
and the somewhat greater constancy of the factors which play a role
in determining distribution. It need only be mentioned, by way of
illustration, that in an aquatic habitat nutrients are more equally
diffused and more readily obtained, temperature changes more
gradual, and annual temperature range less, than in a terrestrial
environment.
Ecologists, however, not infrequently assume a more universal
distribution for aquatics than may actually exist; in a recent excel-
lent volume on ecology one finds a complete disregard of plants in
an aquatic environment. Facts bear out the reasonable assumption
that habitats with similar floras have the necessary determining
physical-chemical conditions in common. Where there are variations
in the flora and when there is an absence of widely distributed
species from certain habitats, correlated modifications in the environ-
mental factors, sometimes obscure, must be sought for. As is well
known, species are subject in their distribution, in water as on land,
to limitations imposed by the presence or absence of certain ecologi-
cal factors. Less than minimal requirements of salts, carbon dioxide,
nitrogen, phosphorus or other nutrients, the degree of illumination,
and temperature changes are a few of the factors involved in distri-
bution and habitat selection.
The part ecological factors play in determining quantity and qual-
ity of algal floras is readily appreciated in a study of lakes in this
area, famous for its great number of inland bodies of water, bogs,
and forested swamps. In Michigan there are about 11,000 lakes,
with a total area of 1137.6 sq. mi.; Antrim County has 10.1 per cent
of its area in lakes, and several other counties have nearly as much
(Brown, 1943). In Vilas County, Wisconsin, the area occupied by
lakes is 15 per cent of the total, although this figure does not include
the innumerable small ponds, permanent pools, and _ spring-like
seeps where algae abound. It is estimated (Juday, 1914, p. xi) that
[4]
approximately 1620 sq. mi. of Wisconsin are water, as compared
with 55,256 sq. mi. of land surface. The suitability for algae of this
entire lake region is reflected in its rich and heterogeneous aquatic
flora.
The great variety of aquatic habitats makes it possible to relate
certain species or complexes of species to what may be called ‘types’
of lakes. In making such a correlation it is of course necessary to rec-
ognize that it is practically impossible to ‘type’ a lake, because each
one, in final analysis, possesses a distinct individuality. It is possible,
however, to classify lakes according to certain characteristics which
are of known biological significance. Most lakes in the region are of
glacial origin, but because geographical and geological features
(and the geological history) are not uniform there are some general
differences to be noted in the bodies of water occupying respective
sections. For the surface features and geology of Michigan the
reader is referred to Leverett (1911, 1917).
The pertinent geological features of Wisconsin have been ade-
quately described by G. M. Smith (1920), and the reader is urged to
refer to the highly informative introduction to his volume, “Phyto-
plankton of the Inland Lakes of Wisconsin, Part I.” In this connec-
tion also see the remarks on p. 8 et seq., of this volume.
SOIL TYPES AND ALGAL DISTRIBUTION
MICHIGAN
The physiography within the political boundaries of Michigan is
extremely varied and is in part complicated by the differences in the
geology of the Upper and Lower Peninsulas. The Upper Peninsula,
lying between Lake Superior on the north and Lake Michigan on the
south, is about 300 miles long, east and west, and averages about 50
miles in width. The Upper Peninsula itself has two definite areas
the character of which is determined by the type of underlying rock
formation. One, west of a north-south line passing through Mar-
quette, is a highland region which continues on over into northern
Wisconsin (to be discussed below), where it is referred to as the High-
land Lake Region. This is underlain by ancient rock formations (Pro-
terozoic) which are covered in most places by glacial drift; notable
exceptions, of course, are the Porcupine Mountains in the far
western part of the Upper Peninsula, and hard ‘knobs’ also project
elsewhere. The basic rock is both sedimentary and igneous. These
crystalline masses seem to have exerted an influence on water
chemistry in certain sections of this western half of the Peninsula,
especially in those sections where the rock is exposed or covered
[5]
by only a thin mantle of glacial deposits. In general, the lakes of the
region are characteristically soft or semi-hard and are poor pro-
ducers of phytoplankton bulk. It is well known that waters associ-
ated with pre-Paleozoic rock are low in calcium, are usually but
little mineralized, and support a predominantly desmid flora, especi-
ally in habitats that possess a low pH. (The symbol pH refers to the
relative amount of free hydrogen ions in a solution. Soft water or
acid lakes have a pH below the neutral point, pH 7.0, whereas hard
water lakes give readings above neutral, pH 7.1-9.8.) Such algal col-
lections as have been made in northwest Michigan, and in the same
topography of northern Wisconsin, bear out this relationship. The
moraines and drifts of sand left by the recession of the last glacial
lobes are largely responsible for the numerous soft water lakes and
acid swamps that are especially abundant north of Michigamme,
in Michigan, and in upper Wisconsin.
The phytoplankton and the desmid flora are characteristic of soft
water lakes in the western section, whereas in the second area, which
forms the eastern part of the Upper Peninsula, the flora is, in general,
that of semi-hard water habitats. This is in accord with the geology
of the area, which is underlain by younger Paleozoic rock, all sedi-
mentary and unmetamorphosed. The eastern section is known as the
Lowlands because the greatest altitude (with possible exceptions ) is
only 250 feet above lake level. Shale and limestone predominate, the
latter forming a tableland along the northern border of the present
Lake Michigan. The Lowlands swing back westward both north and
south of the western Highlands into Minnesota and Wisconsin.
There are numerous outcroppings, and the effect on water chemistry
is marked, finding expression in lakes with a pH generally higher
than that of the western lakes. Like the western province, the eastern
region has been covered by glacial drift that came in with the ice
from northeast Canada, resulting in extensive swamps and sluggish
streams. Whereas there are some habitats (such as an occasional
acid swamp ) that develop a rich algal flora, most of the waters in the
eastern area are not good producers, and the flora is strangely poor
in both bulk and number of species. Many of the slow-flowing
streams of the area are practically barren, and such algal forms as
are conspicuous are cyanophycean or hard water chlorophycean
(Phormidium, Oscillatoria, Spirogyra, Chara). The darkly stained
water of the Tahquamenon River, however, is characterized by a
luxuriant growth of Nitella, a genus almost always confined to soft
water or water rich in humic acids.
Big Spring, near Manistique, Michigan, is an interesting habitat
with an algal flora that seems typical of the region. The spring has
[6]
a tremendous flow of water that forms a deep pool and is the
fount for a large stream. The pool is clear, the water hard, and
there is a luxuriant growth of Chara over much of the bottom. There
is also a scant development of Spirogyra spp. along the fringes of
the pool, while Oscillatoria spp. and Phormidium spp. encrust sub-
merged timbers and water-logged wood. The pool is bordered in
part by the vestige of a tamarack swamp, bedded with Sphagnum.
The water here is only slightly acid, and the algal flora in the
swamp is not rich in desmids as might be expected but very meager
and consists mostly of filamentous Zygnemataceae characteristic of
hard or semi-hard water situations.
In the Lower Peninsula of Michigan, which is also underlain by
Paleozoic rock, there are five physiographic regions. The most
northern one, the Northern Upland, occupies roughly the upper
quarter of the Peninsula and is bordered on the south by a diagonal
line running northeast-southwest from Alpena toward Muskegon
on the west coast. The line swings north, however, before reaching
Muskegon and extends to the lake, passing up and around Man-
istee. The Northern Upland is characteristically a semi-hard and
soft water lake region; although some bodies are basic (pH 7.8,
for example) most of them are below pH 7.1 and some as low as
pH 4.2. Except for a few limestone exposures the region is deeply
covered with a sandy glacial drift which has formed innumerable
lakes and swamps. The result is that the algal flora is richer and
more varied than perhaps anywhere else in the state. There are
both acid swamps favoring a luxuriant desmid and Oedogonium
flora, and mineralized waters supporting a characteristic flora in
which planktonic blue-green algae predominate. Meager water
blooms develop in a few lakes of upper Michigan, which are alka-
line, which have an ample supply of carbon dioxide, and which
have been fertilized by nitrogenous matter from tilled soil or from
human habitation. Such conditions are more common in the south-
ern part of the state, where water is harder and where the lakes
are frequently the eutrophic type.
Southwest from the Northern Upland is the Michigan Lowland,
bordering Lake Michigan. To the southeast is first the Saginaw
Lowland, extending southwest from Saginaw Bay of Lake Huron,
then the Thumb Upland, including the ‘Thumb’ and the greater
part of central southern Michigan. In the Thumb Upland, hard
waters predominate and although there is an occasional kettlehole
type of tamarack swamp, most of the water is rich in calcium, and
the hard water (cyanophyte-diatom) flora prevails. Many lakes are
bedded with Chara, and numerous marl deposits are found in old
[7]
lake bottoms of southern Michigan. The marl lakes are character-
istically poor in both plankton and higher vegetations ( Potamoge-
ton, Ceratophyllum, Myriophyllum). In such hard water lakes,
however, where nitrogenous substances and phosphorus are pres-
ent, higher aquatic plants become so abundant as to cause serious
problems.
The few collections that have been made from the Erie Low-
lands (including the Detroit area and the extreme southeast of
Michigan ) show that here too the algal flora, like that of southern
Wisconsin and Minnesota, is characteristically the hard water type.
WISCONSIN
The geological history of this state has determined six general
soil areas which are shown in F igure 1. Except for the unglaciated
limestone in the driftless area of the southwest corner of Wisconsin,
the soils represent deposits from the various periods of glaciation.
They overlie three chief types of basic rock formation shown in
Figure 2: crystalline rock in the northern third of the state; lime-
stone in the southern third and extending into the Green Bay
region; a sandstone area in the middle portion of the state and the
extreme northwestern corner. These soil types, in combination with
their respective underlying rock formations, determine four great
areas of the state, which, generally speaking, show corresponding
differences in lake types and algal floras.
First, there is a glaciated limestone region, the northern bound-
ary of which extends diagonally east to west, beginning just above
Green Bay in Marinette and Oconto counties and ending with
Green County in the south-central part of the state. This highly
calcareous area occupies most of the southeastern third of Wiscon-
sin. Second, there is an unglaciated limestone area made up of six-
teen southwestern and western boundary counties. Because this is a
driftless area there are few lakes in the region. As would be expect-
ed, the lakes in the entire lower portion of the state, both southeast
and south-central, are rich in calcium, magnesium, carbonates,
and bicarbonates. These qualities, together with such factors as
relative shallowness and high summer temperatures, determine the
character of the algal flora which, in general, is the cyanophyte-
diatom, or hard water type.
In Lauderdale Lake, Walworth County, Wisconsin, for example,
the number of species of Chlorophyta and Cyanophyta are about
equal, but the abundance of the latter far exceeds the bulk of the
green algal vegetation. This is in keeping with the general observa-
tion that where water is warm, rich in fixed and half-bound carbon
[8]
=== RED CLAY
b
1+ GRANITE
b ‘
HEAVY SILTLOAM SC SS
SANDY Rae Sizes
\_|
Se GLACIATED LIMESTONE a ee ES SSE
Xl
~..|
os UNGLACIATED LIMESTONE
= SS as Ee an
ho RSS aati n eee Saae"
{ILE Es 0B Pea SSS. Sas
=
Figure 1. Distribution of the chief soil types in Wisconsin. The unglaciated
limestone region of the southwest is practically devoid of lakes. In the granite
and sandy soils of the northern half of the state, the lakes are mostly soft water,
and there are many acid bogs. In the central and southeast portion of the state,
the lakes are basic (hard water). (Soil data from the Wisconsin Geological
and Natural History Survey. Base map courtesy of A. J. Nystrom and Co. )
[9]
linn
y
LU
IH
i
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A ac tha pr > red:
Tie et s ae Ws Sereatane
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Figure 2. Distribution of three underl
(Data from the Wiscons
courtesy of A. J. Nystrom and Co.)
[ 10 }
dioxide, and high in nitrogen, cyanophycean and diatom species
predominate, both in number of kinds (usually), and number of
individuals. In the lakes which characterize this calcareous region,
blue-green algal water blooms develop during summer periods.
The water chemistry is reflected in the flora of the Green Bay and
Fox River area, where the phytoplankton is made up almost en-
tirely of Microcystis aeruginosa, Aphanizomenon flos-aquae, Lyng-
bya Birgei, Stephanodiscus niagarae Ehrenb., and Melosira spp.,
with infrequent specimens of Pediastrum Boryanum, P. duplex, and
Dinobryon sertularia. The Fox and East rivers drain a calcareous
and clay soil region, gathering considerable quantities of waste from
agricultural lands and industrial plants. Williamson e¢ al. (1939,
p- 66) have expressed the opinion that a heavy bloom of blue-green
algae in these waters is not related to the nitrogen content, but
nitrogen in available form for plants is relatively abundant in
these streams, especially as compared with that in inland lakes.
Bound carbon dioxide is likewise relatively abundant. Such fea-
tures are usually correlated with luxuriant cyanophyte—diatom
floras (see Sawyer, Lackey, and Lenz, 1943). In lakes that have a
chemistry similar to the Fox and East Rivers the number of blue-
green algal individuals may reach several million per liter.
Lake Geneva, Walworth County, Wisconsin, is another hard water
lake 1n the glaciated limestone soil area which is larger and deeper
than Lauderdale Lake. It is high in carbonates (74 ppm), calcium
(20.7 ppm), magnesium (26.9 ppm), sodium (4.4 ppm), and HCO
(110.5 ppm). Analyses of Lake Geneva water samples made in
August 1940 show a relatively high nitrogen content: organic nitro-
gen 0.55 ppm, ammonia 0.01 ppm, nitrate nitrogen 0.8 ppm, nitrites
0.0. As might be expected, the phytoplankton of this lake is predom-
inantly blue-green. Microcystis aeruginosa, Coelosphaerium Naegeli-
anum, and Lyngbya Birgei being the most conspicuous represent-
atives. The green algae which occur here in June, for example, are
Cladophora fracta and C. glomerata, species typical of hard water
habitats. In contrast, the desmid and predominantly chlorophycean
flora appears not to occur in the lakes of this limestone region. There
is further discussion of hard water lakes below.
The third and fourth soil types, which are much less clearly de-
fined, constitute, in general, the upper third of the state. This is
basically a crystalline rock area, but within it are sandy soils and
glaciated granite soils. The former predominate in the north-central]
counties: Vilas; Oneida, parts of Langlade, Lincoln, Forest, Iron,
and Price. The same soil appears in the central part of the state in a
sandstone region including Juneau, Adams, and Monroe counties,
[11]
and there appear to be other sandy islands in the northwestern
and northeastern corners of the state. The glaciated granite soils
lie over crystalline rock areas both east and west of the north-
central sandy soil region. Too few lakes have been sampled in
northwestern Wisconsin to make it possible to generalize on the
relative quality and quantity of the algal flora. Such limnological
data as have been collected by Birge and Juday indicate that there
are fewer soft water lakes in the northwest than in the north-central
and eastern sections of Wisconsin. In Washburn County there is
an extensive sand hill area in which the lakes are characteristically
soft water. Here there was the expected paucity of algae, especially
of phytoplankton.
An interesting situation exists in the Waupaca chain of lakes in
Waupaca County, where there are glaciated granite soils, but also
crystalline rock and sandstone, with small amounts of surface lime-
stone in the extreme southeast (Whitson, Geib, and Tosterud,
1921). The glaciated granite soils extend up into the northeast sec-
tion of the state, and there is a great area of similar soils in the
northwest. Most lakes in this type of soil are soft water, with typical
soft water algal floras. In many of the Waupaca lakes, however, the
water is so exceedingly hard that lime incrustations form on stones
and submerged objects of all kinds. Similar conditions occur in
some south-central Michigan lakes. The floras are typical hard
water types. Chara spp., heavily incrusted with lime, abound in
many lakes. The explanation of these hard water lakes in the sand-
stone and granite soils of Waupaca County is found in the geologi-
cal history of the area. Among the glacial soils brought into this
part of the state from the east there was a considerable amount of
dolomite, the outwash from which is highly calcareous. Hence,
lakes in the Waupaca chain are characterized by hard water floras.
A greater part of the limnological work in Wisconsin has been
done in the granite and sandy soil areas of the northeast and north-
west sections. Accordingly more attention was given the highland
lake areas when the present survey was made, in order to make
correlations possible between types of floras and physical-chemical
data. In the entire northern portion of the state the lakes are char-
acteristically soft, poor in calcium, low in half-bound carbon diox-
ide and nitrogen, and give pH readings on the acid side of neu-
trality. A soft water lake might have 9.8 mg. or less of bound
carbon dioxide per liter, whereas in a hard water lake there might
be 43 mg. or more per liter.
It is in such soft water lakes of northern Michigan and Wisconsin
that finely drawn differences can be noted in algal ecology.
[12]
For although most of the lakes are soft, those which do have a
somewhat alkaline or basic character reflect their chemistry in a
noticeably richer blue-green and diatom flora. In Arbor Vitae Lake,
Wisconsin, for example, a lake somewhat harder than nearby Trout
Lake, a relatively heavy bloom of Gloeotrichia echinulata is sup-
ported, and the flora as a whole is the cyanophyte—diatom type.
A comparison of the algal flora of the northern and northeastern
sections with those of the south and southeastern sections of both
Michigan and Wisconsin leads to the generalization that in the
northern sections the bulk of the algal vegetation is low but the
number of species is high. The larger number of species for the
northern section is due to the luxuriant desmid flora which abounds
in the soft (acid) water lakes and bogs. (See Fassett, 1930; Wilson,
1937, 1941, on the larger aquatic plants of lakes in northeastern
Wisconsin. )
Approximately 200 collections were made from the sandy-crystal-
line rock area of northwest Wisconsin (Burnett, Washburn, and
Sawyer counties). The lakes here, as has been pointed out, are
mostly soft water, with a pH on the acid side. The bottoms
and the shores are sandy, with little aquatic vegetation of any kind.
Of course there are exceptions. Shell Lake in Washburn County,
for example, is a habitat of relatively hard water, supporting a rich
blue-green algal flora. This is the only lake in northern Wisconsin
from which collections were made that had a bloom of Aphani-
zomenon flos-aquae. Although chemical analyses are not at hand
for support, one can predict that this lake is relatively rich in nitro-
gen, as judged by the cyanophyte-diatom flora. This condition might
be expected because the lake lies within the town of Shell Lake
and is bordered, in part, by tilled soil, a situation which makes the
accumulation of nitrogenous substances possible. In contrast is
Round Lake, Sawyer County, a large lake with a considerable
amount of shallow water which supports a very scant phytoplank-
tonic flora, with filamentous forms poorly represented. Chara spp.,
at least when collections were made in August, were found to be
stunted. There were, however, luxuriant beds of Nitella, a genus
which prefers soft water habitats.
LAKE TYPES AND ALGAL DISTRIBUTION
Inland lakes of the region fall naturally into four main types as
determined by hydrographic features. In their Wisconsin lake
surveys Birge and Juday noted and described significant limnologi-
cal characteristics peculiar to these classes. Correspondingly, the
[13 ]
production of plant and animal life, as might be expected, is found
to vary when the biotas of the respective types of lakes are com-
pared. The chief types are: 1) hard water drainage lakes, stream
or spring-fed, with an outlet, at least during part of the year; 2)
hard water seepage lakes (rare), high in calcium, magnesium, and
half-bound carbon dioxide, landlocked; 3) soft water drainage
lakes (uncommon in Wisconsin and Michigan), low in calcium and
half-bound carbon dioxide, with inlet and outlet; 4) soft water
seepage lakes (common, particularly in northern parts of the area,
in the northern part of the Lower Peninsula, the Upper Peninsula
of Michigan, and in upper Wisconsin), low in calcium, magnesium,
and half-bound carbon dioxide, fed by seepage or drainage from
bogs, without outlet.
To these four classes, two other types of lakes should be added:
5) acid bog lakes, mostly seepage, low in calcium; 6) alkaline
bog lakes, mostly drainage, relatively high in calcium.
In general, the lake types are determined by differences in their
geological history, differences principally related to glaciation. The
most recent glaciation, Late Wisconsin, obviously had the greatest
influence on the present physiography of the region. Although
most lakes had their birth during and following the closing years of
this period, it appears likely that a few of the deeper lakes, Lake
Geneva and Green Lake in Wisconsin, for example, may antedate the
Late Wisconsin. There are at least four types of lake formation in
the Great Lakes region: 1) depressions formed by the melting away
of great blocks of glacier fragments and the subsequent sloughing
off of glacial drift so that mounds of debris were left about a kettle-
hole, which is usually soft and is frequently the acid bog type; 2)
lake basins formed by the damming of preglacial valleys; 3) basins
created when terminal moraines were formed in parallel ridges and
the intervening valleys dammed subsequently by deposits at either
end; and 4) depressions formed in the ground moraine. (See
Juday, 1914. )
The lakes which were left with an outlet became immediately a
part of a drainage system Other drainage systems were evolved by
subsequent wearing away of impounding glacial deposits and
through variations in water level. Thus some lakes were included
in a drainage system, but others were left perpetually land-locked
and doomed consequently to extinction. Fundamental differences
between the drainage and seepage types of lakes, which are so con-
spicuous today, are related, therefore, to the mode of the lakes’ for-
mation in the remote past.
[14 ]
Harp WATER DRAINAGE LAKES
These lakes are numerous and are to be found in such drainage
systems as the Wisconsin River, the St. Croix River, the Fox River,
and the Yahara River in Wisconsin, and in the Crooked River and
Cheboygan River in Michigan. In general, they are high in calcium
and half-bound carbon dioxide (see Table 1) and correspondingly
have a high pH (pH 7.2-9.4). Reference has already been made to
this type of lake and its characteristics. In southern Michigan and
Wisconsin, most drainage lakes are naturally harder than in the
northern parts of the states because of the difference in the chemis-
try of the soil. It is noteworthy that when the drainage type of lake
in the highland region has a sandy bottom, and few flat beaches
or shallow bays, it may be as poor a producer as some of the soft
water lakes. In Table 1, 13 hard water drainage lakes are listed to
show something of the quality of their algal floras in relation to
critical limnological features. Compare Table 1 with Table 2,
which summarizes collections made in Wisconsin from December
through July.
These general quantitative and qualitative observations contribute
to the evaluation of the hard water lake as an habitual producer of
blue-green and diatom floras which are rich both in number of spe-
cies and in number of individuals. Chlorophycean species, on the
other hand, while not always fewer in number than the components
of the cyanophyte-diatom flora, comprise but a small portion of the
bulk of algal vegetation in hard water lakes. Except for the Volvo-
cales, they seldom, if ever, form water blooms. Certain members of
the Volvocales, Volvox and Pandorina, in some lakes may reach cli-
maxes that form blooms, though of relatively short duration.
Drainage prevents hard water lakes from achieving a constantly
high concentration of nutrients; yet the chemistry of the water,
together with such eutrophic features as shallowness and high sum-
mer temperatures, make possible the characteristic luxuriant flora.
This type of lake may also have a high productivity of larger aqua-
tic vegetation—Sweeny Lake in Oneida County and Lake Mendota
in Dane County, Wisconsin, and Ocqueoc Lake in Presque Isle
County, Michigan, for example.
Although there is conflicting evidence regarding the role that
phosphorus plays as a controlling factor in the development of
aquatic floras, many critical studies indicate that it is a regulator.
It is well known that soluble phosphorus in a lake decreases with
the seasonal increment in plankton and increases as organisms die
and disintegrate. Tressler and Domogalla (1981) have shown that
in Lake Wingra (Wisconsin) soluble phosphorus declines and
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TABLE 2
OccURRENCE OF ALGAE IN Four WISCONSIN HARD WATER LAKES
(From Sawyer, Lackey, and Lenz, 1943)
Number of species, with percentage of their occurrence in samples |
Lake and Kegonsa Wingra
No. of Samples (9) (30) (25) (10)
Dinoflagellates fo | aso | 2 c50%) | 3 (23%)
Cryptophyceae 4 (50% 5 (49%) | 5 (56%)
) )
)
Chrysophyceae 6 (18% 8 (12%) 8 (15% 10 (23%)
Euglenophyta 8 (10%) 8 ( 7%) 8 (15%)
Chlorophyt
eerie) 16 (23%) | 35( 9%) | 26(14%) | 41 (24%)
remains low during the spring and summer months but increases
during the fall and winter periods when there is a reduction in the
plankton. In general, where the total phosphate and nitrate con-
tent of drainage lakes is high, the algal flora is abundant. This
relationship is clearly demonstrated by the higher productivity of
plankton bulk in such lakes as Jordan in Michigan and Wingra in
Wisconsin when compared with the productivity of lakes in the
northern areas. It is noteworthy that in some of the Yahara River
lakes near Madison there is a significant relationship between exces-
sive growths and blooms of algae and the high phosphate-nitrate
content resulting from sewage effluents and run-off water from
populated areas. A similar condition is observable in Jordan Lake,
Michigan, and in some of the eutrophic lakes in northwestern Iowa
which have received a continuous flow of fertilizing elements during
the past few decades.
Lake Mendota, Dane County, Wisconsin, in the Yahara River sys-
tem, is a typical hard water drainage lake. The pH ranges from 7.4
[17]
TABLE 8
ABUNDANCE OF THREE CLAssEs OF ALGAE, LAKE MENDOTA, WISCONSIN
Average number of individuals per liter of lake water
(22 spp.) (6 spp. ) (15 spp.)
January 612 1,668
February eae at 1,912 754
March 31 879 414
April 130 504 1,661
May 2,695
June
13,059
July 3,904
September 10,413
October 398 1,969 28,751
November 155 4,666 5,016
December 114 782 17,780
Norte: Readings for August were not available for the table.
in February to 8.6 (surface level) in August and October. In Feb-
ruary, readings for carbonates at 21 meters have been as high
as 43 ppm. Fixed carbon dioxide is relatively high, 36-37 ppm.
Hardness is 163 mg. per liter (American Public Health Unit). Inor-
ganic nitrogen is 0.08-0.36 ppm, whereas total nitrogen varies from
13.1 ppm at the surface to 15.2 ppm at 22 meters depth (June). Sol-
uble phosphorus occurs in 0.01-0.02 ppm. Correlated with these
physical-chemical characteristics, the algal flora is predominantly
the cyanophyte-diatom type, although during summer months there
may be a dense growth of Staurastrum (a desmid genus), which
gives the Chlorophyta a larger representation as far as number of in-
dividuals is concerned. The over-all bulk of algal vegetation is not so
great in Lake Mendota as in some of the other bodies of water in the
[ 18 ]
Yahara River system, but water blooms occasionally develop in it.
The average number of individuals per liter of lake water for the
Chlorophyta, the Cyanophyta, and the diatoms are listed in Table 3.
These figures were obtained by counts from centrifuged plankton
samples from Lake Mendota, Wisconsin, a typical hard water drain-
age lake. It will be noted that it is only in the months of May, June,
and July that the Chlorophyta exceed the Cyanophyta in numbers
per liter. It is interesting also to note that the numbers represent 22
species of Chlorophyta, only 6 species of Cyanophyta, and 15 species
of diatoms. This is a more nearly equal distribution of species among
these three groups of algae than usually occurs in a hard water
drainage lake when sedentary or attached species, as well as plank-
tonic forms, are considered.
HARD WATER SEEPAGE LAKES
This type of lake is rarely found in our region, for seepage lakes
are characteristically soft. Spider and Round Lakes, Vilas County,
Wisconsin, are examples. Sloughs which have no outlet and some
swampy ponds might be included in this class. Characteristics of
hard water seepage lakes are shown in Table 4. These habitats, as
might be expected, are not unlike the northern hard water drainage
lakes except that the chlorophycean flora equals or exceeds the cyan-
ophycean in abundance. Although the pH of the water in such lakes
was found to be always above neutral, it is likely that great varia-
tions would be discovered if readings were made throughout the
year. A much higher pH would be expected in late summer months
because of increased photosynthetic activity which removes the half-
bound carbon dioxide from the bicarbonates.
Euglenoid genera, such as Phacus, Euglena, and Trachelomonas,
and some of the Chrysophyta, Tribonema spp. and Synura uvella,
for example, are typical components of the algal flora in hard water
seepage lakes.
SorT WATER DRAINAGE LAKES
Soft water lakes are nearly always of the seepage type; a soft
water lake with drainage, or a seepage lake with hard water, is sel-
dom found. It will be noted in Table 5 that soft water drainage lakes
have limnological and biological characteristics very similar to the
soft water seepage type. The algal flora, in both quality and quantity,
is predominantly chlorophycean. The phytoplankton is sparse, some-
times lacking except for an occasional diatom. It is noteworthy also
that the available total-nitrogen readings for soft water drainage
[19]
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TABLE 6
A CoMPARISON OF WISCONSIN DRAINAGE (D) AND SEEPAGE (S) LAKES
Fixed
CO2
(aver. mg./L)
155,11 — .026 1.26
and diatoms
Arbor Vitae (D) | 7.0-8.4 22.0 102 024 1.86
predominate
Crystal (S) 6.0-6.4 1.4 Ste 016 0.48 pot
Plankton Blue-green
Conductance (averane 70) algal
flora
++
Blue-greens
and diatoms
predominate
Allequash- (D)
Few species,
not abundant
+
Species domi-
nant but not
abundant
Few blue-
greens
+++
Blue-greens
+
Few species,
but fairly
abundant
Few species,
on bottom
++
++ Abundant in
Fishtrap (D) 7.1-8.0 17.5 52-70 .026 Gonnnon species and
numbers
Clear (S) 6.1-6.8 3.6 016 0.66 Rare Few
The relative degree of abundance of blue-green algae is indicated by the plus and minus signs.
lakes are higher than those for hard water drainage or soft water
seepage types. This suggests that if other essential nutrients were
present, the soft water drainage lake might be more productive.
High nitrogen content is correlated seasonally with a low plankton
count, for when the plankton is high, especially during summer
months, the nitrogen content of the lake water is low, increasing,
however, as the biota decreases in fall and winter. In many seepage,
acid lakes (Lynx and Mary Lakes, Wisconsin, for example), the
desmid flora has an abundance approaching that of bog lakes, which
are highly productive.
SoFT WATER SEEPAGE LAKES
In Table 6 three typical hard water drainage lakes are compared
with three soft water seepage bodies. The latter type of lake usually
has a sandy bottom, with few bays and shallows; the nutrients are
low in concentration and the half-bound carbon dioxide content is
much less than in the drainage lake. In soft water habitats the algal
flora is almost entirely planktonic, and even this is relatively scant.
Filamentous algae are practically non-existent. In many such lakes,
only sterile Mougeotia and Zygnema can be found, entangled about
the culms of rushes that form sparse beds. Zooplankton is scarce in
the soft water lakes, which further explains their general low produc-
tivity of fish. The total plankton residue (dry weight analysis) in
Crystal Lake, Wisconsin, is only 0.48 mg. per liter (Birge and
Juday ). When a soft water lake is found capable of supporting a sub-
stantial fish population, it is obvious that at least periodically there
must be crops of phytoplankters of sufficient magnitude to support
the intermediate zooplankton elements of the food chain. The pro-
portionate production of fish in a soft water lake has been made very
graphic in a paper by Juday (1942). One of his diagrams is shown
in Figure 8. This illustrates the quantitative relationships of the sev-
eral components of the biota as expressed in kilograms per hectare of
lake surface (wet weight, ash-free computation). See also Table 7
for analyses of 27 soft water seepage lakes.
One of the many interesting problems involved in the differences in
production of soft and hard water lakes is the role played by hetero-
trophic bacteria. The unanswered question is: Do the nature and
abundance of the biota determine the kind and quantity of the bac-
terial flora, or does the bacterial flora function critically in releasing
nutrients which, if sufficient, make possible an abundant and varied
algal flora through the overturn of organic matter? This is doubtless
a vicious circle, but Henrici and McCoy (1938) and Henrici (1939)
have shown that soft water, oligotrophic lakes have fewer bacteria
[ 28 ]
2 eee eee e eee e-- Bottom flora
Sewewwesccos Phytoplankton
-----Dissolved organic
matter
Figure 3. Relative weights of various components of the biota and dissolved
organic matter in Weber Lake, Wisconsin, a soft water seepage type. Scale:
4.9 sq. mm. = | kilogram per hectare. (From Juday, 1943)
than hard water, eutrophic habitats. In their studies Henrici and
McCoy (l.c.) show that the bacterial flora of the bottom is larger
in numbers of individuals than that of open water and that, as might
be expected, the difference between the bottom and upper level
flora is greater in eutrophic than in oligotrophic lakes.
In oligotrophic Crystal Lake, Vilas County, Wisconsin, for ex-
ample, the bacteria count per cc. of bottom mud sampled was 2,160;
whereas in Alexander, a eutrophic lake in Minnesota, the count was
144,240 per cc. of bottom “kalkgyttja.” In the former lake the total
bacterial flora of the bottom (average bacteria per cc. x depth of the
mud) was 38,880 as compared with 2,599,320 in Alexander Lake.
In the examination of the open water of the two lakes, an inter-
esting bacterial count was secured. In Crystal Lake the average was
80 organisms per cc.; in Alexander, 675 per cc. When the ratio of the
number of bottom bacteria to open water bacteria in the two lakes is
compared, an even greater difference is noted. In Crystal Lake the
total open water flora (average bacteria per ce. x depth of the lake)
is 159,900, which, when compared with 38,880 on the bottom, gives a
quotient of 0.2. A much higher ratio is found in the eutrophic type
of lake. In Alexander there was a total of 538,300 organisms in the
[ 24 ]
open water, or a quotient of 5.0 when this is compared with
2,599,320 in the total bottom count.
The activity of bacteria produces food substances for bottom or-
ganisms, as previously mentioned, and at the same time increases the
concentration of nutrients available for plant and animal life in the
upper levels. It is obvious that the quantity and quality of the bac-
teria in both bottom and open water floras can produce effects in
the chemical nature of the water, and in the chemistry and physical
condition of the bottom sediments. In a sense a closed cycle is in-
volved here. In the first place a rich bacterial flora, through the rapid
breakdown of organic matter, may produce (at least indirectly) a
varied and rich phytoplankton and zooplankton. The quantity and
quality of the microbiota, in turn, have far reaching effects on the
productivity of other kinds of animal life, both on the bottom and
in open water. And finally, the relative abundance and quality of the
organisms (i. e., productivity ) within a lake determine whether the
bottom sediments will support a rich bacterial flora. The role of
bacteria in this cycle has been clearly summarized by Waksman
(1941).
The characteristic paucity of nutrients in a seepage lake is explain-
able, at least in some instances, by the source of the water, which
percolates through sand and crystalline soils. Frequently there is
seepage from bogs and marshes, with the result that the water is
rich in humic acids. Birge and Juday found only 3-4 grams of or-
ganic matter per cubic meter in the soft water type of lake; of this
amount, 15-18 per cent was accounted for by the plankton. Over a
three-year period they found that the total nitrogen content of such
a lake averaged 7.2 per cent of the dry weight of the plankton per
cubic meter of water (as determined by ash-free analyses ).
Table 7 lists 27 typical soft water seepage lakes with their biota
and critical limnological features.
Acip Boc LAKES
The acid bog lake, usually found in Sphagnum bogs, is of the
kettlehole type. The water is at times acid, although the marginal mat
may be more acid than the open water. Here are found a great vari-
ety of desmids and a few Cyanophyta, such as Scytonema ocellatum,
Hapalosiphon pumilus, and Chroococcus Prescottii. The plankton
of these lakes is not abundant, usually, but the filamentous forms
are luxuriantly developed, especially in the marginal waters and
in the small seeps leading into the lake. Such bodies of water are
aging rapidly, and there is a great accumulation of organic matter,
[ 25 ]
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much of which eventually forms peat because it is only partially de-
cayed by bacterial action. Microspora spp. are often the dominant
filamentous forms, attached to Chamaedaphne stems at the margin
of the open water. It has been observed that Oedogonium, often
abundant in the vegetative condition, in the open water portion of
acid bog lakes, rarely reproduces sexually there. In the pools and
ditches of the marginal mat, however, where there is a concentration
of organic acids and decaying matter, and where temperatures are
higher, fruiting plants are abundant and numerous species may be
identified in a single collection. Batrachospermum spp., in luxuriant
tufts, are also characteristic of the acid bog lake. In general it may
be stated that this type of lake, when shallow enough to permit opti-
mal temperatures, is more productive than any of the other types in
number of algal species.
ALKALINE Boc LAKES
The alkaline or basic bog lake usually involves a stream meander-
ing through a kettlehole depression which has never been entirely
closed. Mud Lake, Cheboygan County, Michigan, and a small lake
near High Lake, Vilas County, Wisconsin, are clear examples. Al-
though there is an acid type of terrestrial flora forming a marginal
mat around such lakes, the water is fairly hard. The pH is 7.1-7.4,
the bound carbon dioxide is 21.8 ppm and calcium is 11.25 ppm;
the conductivity 85. They have, therefore, the chemistry of semi-
hard lakes, but the algal flora is poor both quantitatively and qual-
itatively. There is a conspicuous growth of Spirogyra crassa, S.
decemina, and Chara spp., all calcophiles (hard water organisms ).
SUMMARY
Some of the correlations between types of algal floras and physi-
cal-chemical conditions in lakes are summarized in the charts in
Figures 4, 5, and 6. The diagrams are based on analyses of 100 lakes
in Vilas and Oneida counties, Wisconsin, selected at random from
the list of habitats from which collections were made. The samples
upon which counts of algal species are based were collected during
July and August. The chemical data are from the records of E. A.
Birge and C. Juday.
In Figure 4 the graph at the left shows the distribution of the lakes
according to pH readings (expressed in number of lakes which
fall within the pH range indicated). As will be noted, the majority
of the lakes in the sample have a pH near 7.5. Only a few are as
basic as 8.3; a somewhat larger number are as acid as 5.3. Correlated
[ 28 ]
BLUE- GREEN
GREEN ALGAE ALGAE a
Figure 4. Diagram showing the number of Wisconsin lakes (in a random
sample of 100) which lie within different pH readings; their bound carbon
dioxide content (expressed in parts per million); and the percentages of green
and blue-green algal species in their total algal flora. (See discussion in text. )
[ 29 ]
with this distribution is the first graph to the right, which shows the
amount of bound carbon dioxide that occurs in the lakes (expressed
in parts per million). As would be expected, since the majority have
a pH above neutral, most of the lakes have a relatively high bound
carbon dioxide content in the form of calcium and magnesium car-
bonates. In the particular group of lakes under consideration the
bound carbon dioxide content was no higher than 14 ppm, however.
The graphs on the right of this diagram show the distribution of
green and blue-green algal species (expressed in percentages of the
lakes’ total algal flora). It will be noted that where both the bound
carbon dioxide and the pH are high the percentages of blue-green
and green species are approximately equal. With a lowering of the
pH and a corresponding decrease in the amount of bound carbon
dioxide, however, there is an increase in the percentage of green
algal species, reaching 100 per cent of the flora in the highly acid
lakes. This increase is in almost exact inverse proportion to the
decrease in the carbon dioxide content. In this connection it should
be pointed out that there is no causal relationship between large
numbers of individuals or numbers of species and high bound car-
bon dioxide content since in this form it is unavailable to most vege-
tation. Bound carbon dioxide content is significant, however, and is
useful in providing an index of algal production, because almost in-
variably a lake with a high bound carbon dioxide content will also
be high in bicarbonates. Half-bound carbon dioxide in Ca(CO3)o
and MgCa(CO3)z is available to photosynthetic organisms, and it
follows that such lakes are able to support an abundant algal flora,
other factors being also favorable. Whereas the relationship between
half-bound and bound carbon dioxide mentioned above usually
holds, it is possible in senescent lakes to have a high bound carbon
dioxide content with little or no half-bound or free carbon dioxide.
In such cases one would expect to find a very scanty algal flora and
a heavy deposition of marl or some similar carbonate. See Welch
(1935) for an outline of the relationship between available carbon
dioxide and bicarbonates.
In Figures 5 and 6, the lakes used in this analysis are divided into
four groups: hard water drainage (HD), soft water drainage (SD),
hard water seepage (HS), and soft water seepage (SS). In Figure 5
the distribution of the hard and soft water drainage lakes according
to pH readings is shown in the graph on the left. With this distribu-
tion is compared bound carbon dioxide content, as in Figure 4. As
was noted in Figure 4, the blue-green and green algae are present in
almost equal percentages in the hard water lakes; the acid lakes have
by far the larger percentage of green algae and almost no blue-green
[ 30 ]
> @®
ae ©)
om
>mM
m2
mcr ow a
MPS>Oor > ZMMVO
HARD :
9 NO
SOFT
6 DRAINAGE % ALGAE
SPECIES
leet
0 5 0.0%
Figure 5. Diagram showing the percentages of hard and soft water drainage
lakes in a random sample of 100 Wisconsin lakes; their bound carbon dioxide
content (expressed in parts per million); and the percentages of green and
blue-green algal species in their total algal flora. (See discussion in text.)
[31 ]
BOUND CO, %, OF
PPM ALGAE
| SPECIES
NO 753 001
TLARD
[a hl
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TA:
: ' |
‘ '
: bar in
‘
uJ )
' t De
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1 ‘
ut
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‘ ' ua
GREEN
ALGAE
Figure 6. Diagram showing the relative number of hard and soft water
seepage lakes in a random sample of 100 Wisconsin lakes; their bound carbon
dioxide content (expressed in parts per million, the highest being 14); and
the percentages of green and blue-green algal species in their total algal flora.
(See discussion in text. )
[ 32 ]
flora. The decidedly larger number of algal species in the highly
basic lakes is related to the richness of the phytoplankton in such
habitats. It is in lakes with pH readings such as these that blue-green
species often produce water blooms.
As was mentioned previously in another connection, hard water
seepage lakes are rather rare. This is seen in Figure 6, which shows
a few lakes having a pH between 7.2 and 7.7. In at least one of these
lakes the bound carbon dioxide was as high as 14 ppm. In such lakes
the green algal species are sometimes three times as numerous as the
blue-green.
A considerable number of soft water seepage lakes were found
among those used in this analysis; most of these had a pH between
6.0 and 6.8. As with the soft water drainage lakes, the seepage lakes
have floras predominantly of the green algal type. It should be men-
tioned, however, that some of the soft water seepage lakes have a
great bulk of certain blue-green algae, but the number of species is
very small.
[ 33 ]
Relationships of Phytoplankton
to Lake Productivity
One of the more interesting problems confronting the aquatic bi-
ologist, and one of great practical importance, is that of productivity.
By this term is meant the quantity and quality of plant and animal
life which a body of water is capable of supporting. Limnology com-
prises such a heterogeneity of fields of inquiry that limnological
studies often seem to lack correlation. Nevertheless, the chief aim of
the limnologist is to devise methods of evaluating productivity of
aquatic habitats for both purely scientific and practical purposes.
Many of the problems that arise in shellfish culture, fish management
programs, and similar projects are problems of productivity. Consid-
erable progress in both the Old and New Worlds has been made
in determining index characters by which productivity of aquat-
ic environments can be evaluated and predicted; that is, a set
of characteristics or standards by which a lake may be measured in
respect to the quantity and kinds of plants and animals it can pro-
duce. Physical-chemical factors, however, seem to defy analysis be-
cause they interlock and interact in bewildering complexities. Since
they are never quite the same in any two lakes, they give each body
of water a distinct individuality. Thus limnologists find great diffi-
culty in determining a productivity index which can be generally
applied. A brief consideration of a few biological and physical-chem-
ical factors involved in the relationships of the algae to productivity
in lakes is in order here.
No more graphic outline of the factors involved in production
is at hand than a diagram prepared by D. S. Rawson (1940). Re-
ferring to this diagram (reproduced here, Fig. 7), it is of interest to
check through the factors, noting which ones have a direct bearing
upon the quantity and quality of the algae and other plant life,
factors which also influence animal life, of course, either directly or
indirectly. As complex as this chart may appear, it is, of necessity, a
simplified presentation of the multitudinous factors involved and
shows none of the ramifying and anastomosing interactivities of the
components. If the contributing agents shown in this chart were to
be analyzed further, the diagram would become very much in-
[ 34 ]
Geographic Location
lume! eolog) Latitude
es S jical Topogra’ Lonat
Influence Formation pography \\\ a
A sare Compas Shape of Basin Climate
; as
iti i Bottom Precipitation Wind Insolation
ret Ha ccs ae Se
jaterial
oe int of Seasonal Cycle
pains of Inflow a Trans- Light Heat Reostrattce aS Oees Penetr. Devel eats osente cre
pareacy — oF ue Stratthcation Utincation Growing Season
— 1D
Trophic Nature of the Lake
Amount, com and distribution of
Prengal petal Also
rates of circulation.
“Productivity”
Figure 7. A diagram showing the contributions toward lake productivity
by some interesting factors, both inside and outside of a body of water After
a diagram by D. S. Rawson. (By courtesy of the American Association for
the Advancement of Science. )
volved. For example, ‘primary nutritive materials’ depend on many
specific factors which are interrelated with and are governed by
‘topography, ‘drainage area,’ and the ‘inflow of allocthonous mater-
ials.’ The availability to plants of the ‘primary nutrient materials,
such as nitrogen, phosphorus, and various salts, would be, in part,
determined by ‘oxygen concentration and utilization, as well as by
the ‘seasonal cycle of circulation and stagnation.’ ‘Depth’ and ‘wind’
together, or wind alone, directly affect turbidity (‘transparency’),
[ 35 ]
which in turn determines ‘light penetration. The amount of carbon
dioxide (not indicated as such on the chart) is regulated by a num-
ber of factors shown in this chart. Carbon dioxide plays an important
role, of course, because of its relationship to photosynthesis and
hence to the amount of plant life.
As has been pointed out by Chandler (1944) all these factors fall
into three groups or classes: edaphic, morphometric, and climatic. In
this paper he relates seasonal pulses and annual variations in the
quantity and quality of the phytoplankton to some of these factors.
He found the most important to be turbidity, solar radiation, and
temperature.
CHLOROPHYLL AS AN INDEX OF
PRODUCTION
It is sufficient to say that chlorophyll in water plants, as in land
plants, is the all-important agent and initiator in a series of physical-
chemical changes which culminate in and are responsible for the
fauna. In this connection, mention should be made here of the pos-
sible use of chlorophyll measurements as indirect, if not direct, in-
dices of potential productivity.
An approach to such an evaluation of production has been de-
scribed by Kozminski (1938). He secured acetone extractions of
chlorophyll from the phytoplankton at different lake levels and then
made quantitative readings by measuring the absorption of light
waves 6200-6800 A in length. By this photometric method he was
able to secure an index of phytoplankton production in terms of the
amount of chlorophyll at different lake levels. By plotting the chlor-
ophyll (expressed in Mg./M*) against depth in meters a useful in-
dex of the amount of phytoplankton at different levels is obtained.
Then when the curves from various lakes are compared an evalua-
tion of respective productivity potentials is established on the basis
of the available chlorophyll. (See Fig. 8. )
It is interesting to correlate these readings (Fig. 8) with the qual-
ity of the phytoplankton and limnological characteristics. In Scaf-
fold Lake, Wisconsin, for example, there is shown to be very great
absorption of light in photometric tests, especially between 2 and 8
meters, and we find a very dense flora of nannoplankters. At the time
observations were made, the lake had a peculiar bluish-tan color from
a tremendous population of the chlorobacteriacean Pelogloea bacil-
lifera. This is a colonial organism with minute cells rather loosely
held in soft mucilage. In a plankton net, the aggregates usually
break up and only individual cells or small clumps appear when the
[ 36 ]
CrioropHyyy in Mo/M®
Figure 8. Graph showing vertical distribution of chlorophyll as determined
by Kozminski’s photometric studies of a number of Wisconsin lakes. C—
Crystal; H—Helmet; Ma—Mary; Mu—Muskellunge; Sc—Scaffold. The ordinate
represents depth in meters. The high chlorophyll-content of Scaffold Lake at
eight meters is caused by an abundant growth of Pelogloea bacillifera
Lauterbon. (From Kozminski, 1938. )
sample is examined microscopically. The organism is easily mistaken
for a cluster of bacterial cells. In Scaffold Lake, Pelogloea bacillifera
was apparently the only organism responsible for the heavy absorp-
tion in Kozminski’s photometric analyses. Phormidium mucicola was
the only other species found, and this was seen only after samples
of the lake water had been cultured in the laboratory.
The rather curious flora of Scaffold Lake is accompanied by an
equally interesting chemistry. The pH is high in the upper levels
(pH 8.6-9.2) but drops to 6.3 at‘nine meters. Bound carbon dioxide
is relatively low at the surface (5.0 ppm), but rises to 14.9 ppm at
the bottom. Free carbon dioxide is likewise low at the surface (3.0
ppm) but is plentiful at or near the bottom (41.0 ppm). Calcium is
present in 2.37-2.83 ppm. The color index is 26 (platinum cobalt
scale). These data make it possible to classify Scaffold Lake as a
medium hard water habitat, capable of supporting a luxuriant algal
flora; hence it could be said to have a high production potentiality.
An index to this is also to be found in Kozminski’s chlorophyll analy-
ses. (See also the remarks by Dutton, 1941, p. 397; Dutton and Man-
ning, 1941, p. 516; Manning and Juday, 1941, p. 363. )
In such a transparent lake as Crystal (Wisconsin) the chlorophyll
content is relatively low at all levels (Fig. 8), but shows a slight in-
crease near the bottom. This is in keeping with the prediction one
[ 37 ]
would be able to make on productivity of this lake from a considera-
tion of other limnological features. The pH is low (6.0-6.4). The free
carbon dioxide is 1.25 ppm near the surface, although at the bottom
it is high, 10.5 ppm. The conductivity is low, the mineral content al-
most non-existent. It is reported that the water from Crystal Lake
can be used safely in storage batteries. Repeated tow samples from
this lake (July-August) yielded scarcely a single plankter, and there
was a negligible amount of attached filamentous algae in the shallow
water zone. On the bottom, at 10-15 meters, however, there is a car-
pet of the aquatic moss Drepanocladus fluitans and a meager algal
flora of 15 species (including desmids). The stratum of vegetation
accounts for the rise in chlorophyll content, shown by Kozminski
(I.c.), in a layer where there is also an increase in the amount of
available carbon dioxide.
PHYSICAL-CHEMICAL FACTORS
The quantity and quality of the algal flora is affected by many
edaphic factors, and in turn these plants produce effects in the phys-
ical-chemical factors in the medium. These effects may directly or in-
directly influence the biota of the environment, sometimes very dras-
tically. Algae alter the oxygen and carbon dioxide content of the
water, cause the pH to fluctuate, contribute to the nature of bottom
sediments, and in other ways initiate series of cause-effect inter-
actions. It is recognized that these changes are involved in what may
be called algal ecology. This is an ill-defined term and broad in its
application because it must cover such a complex of interacting fac-
tors and processes of nature. Since life itself is the product of these
processes and the responses that protoplasm makes to them, it is not
possible to regard any one ecological factor as more important than
another. Carbon dioxide and oxygen might be selected arbitrarily for
primary consideration.
CARBON DIOXIDE
Carbon dioxide and carbon dioxide tension (Burr, 1941) are criti-
cally important and only those bodies of water abundantly supplied
with this gas, free or at least available, can support a luxuriant
growth of algae. The quantity of carbon dioxide is regulated by
a number of factors, many of which, in turn, are related to climatic
conditions and geological events of the remote past. The temperature
of the water at different times of the year and in different strata, the
amount of carbon dioxide released by respiration, the chemical
nature of the bottom and the overturn of organic matter by bacteria,
[ 38 ]
the geographical and physiographic features of the terrain surround-
ing the water (or, in the case of a river, the land drained by it), all
have their bearing on the carbon dioxide content.
Because of its crucial position in the lake’s metabolism, a radical
unbalancing of the amount of carbon dioxide in solution is felt
throughout the entire biological cycle. A minimum amount will limit
the quantity of phytoplankton a body of water can support, as
indicated above in the remarks on Crystal Lake. A boundless
supply, together with other favorable conditions, may influence the
development of a superabundant water bloom, followed by a series
of disturbed biological conditions. Examples of this are to be
found in the prevalent water blooms in southern Michigan and
Wisconsin, in Minnesota, and in some northern Iowa lakes. Only
rarely have northern lakes been found with floras which approach
the bloom condition. In southern parts of Wisconsin, the richness of
the algal flora in the limestone region, as previously mentioned, is
related to a high bound and half-bound carbon dioxide content.
For example, Lake Geneva in Walworth County contains an average
of 20.7 ppm of calcium and 3.7 ppm of carbonates. Trout Lake in
Vilas County, a medium hard water lake, contains but 6.7 ppm of
calcium and no carbonates. This great difference in the amount of
available carbon dioxide is correlated with a great dissimilarity of
the floras. Lake Geneva has at times a dense bloom of the eutrophic
type, but in Trout Lake there is a relatively scant growth of algae in
the main body of water. Birge and Juday (1911) have shown that
there may be as many as 1000 phytoplankters per liter (mostly Oscil-
latoria sp.) at a depth of 15 meters in Lake Geneva At this level,
free oxygen was 2.4 ppm and the temperature was 13.6° C. It may
be of interest here to point out that the number of phytoplankters
may be as high as 9 million (filaments, not cells) per liter in hard
water lakes during periods when water blooms flourish (Prescott,
1932).
Although an adequate supply of carbon dioxide is essential, an in-
crease in carbon dioxide tension, especially if rapid, may either kill
fish or seriously upset their physiology. Death is brought about more
or less directly through failure in elimination of carbon dioxide from
the body on account of the high concentration of carbon dioxide in
the water, or indirectly through ionization forming injurious car-
bonic acid (Powers, Shields, and Hickman, 1939).
Again, the basic chemistry of a lake varies greatly as carbon diox-
ide is removed from the bicarbonates. Some Iowa lakes that I sur-
veyed developed a pH of 9.6-9.8 in the upper zones during the sum-
mer period of accelerated photosynthesis; an increase for the period
[ 39 ]
of as much as 2.4. This is, of course, a logarithmic expression of in-
crease and represents an enormous change in water chemistry with
far-reaching biological effects.
OxYGEN
It is obvious that oxygen is one of the primary limiting and deter-
mining factors in phytoplankton ecology, as for all other forms of
life. Because of their photosynthetic activities, plants in daylight are
practically independent of free oxygen in solution. When carbon di-
oxide is present in sufficient quantities and other factors are favor-
able, chlorophyll-bearing organisms can automatically maintain the
required amount of oxygen needed for their own respiration. But at
night plants are required to draw upon free oxygen in the surround-
ing medium for this process. When there are excessive growths of
algae, particularly in warm shallow water when the oxygen content
is low, the available supply of oxygen may be reduced to a point be-
low the amount normally required by the fauna. Thus, by increasing
or decreasing the oxygen content, algae act as agents in determining
the quantity and kinds of animal life which a body of water may
support at different levels. Photosynthesis, however, is regulated by
such factors as carbon dioxide, discussed above, and light.
LIGHT
Illumination as an ecological factor determines that most algae,
particularly plankters, occupy what is termed the photosynthetic
zone, the upper 2-5 meters of water. Turbidity, color, and amount of
disturbance at the surface all help to determine the depth to which
light favorable for photosynthesis will penetrate. Because of the
great amount of light lost at the surface through reflection and be-
cause of further reductions by absorption and diffusion, photosyn-
thetic plants are required to carry on their activities in the upper
levels. This explains the (usually) greater quantity of dissolved oxy-
gen in this stratum. The exhaustive studies of Birge and Juday
(1911) describe the gas content and its fluctuations in 156 lakes.
Their graphs clearly illustrate this relationship between oxygen and
the photosynthetic zone. In their Figure 135 (p. 243), curves are
shown for the oxygen content of Lake Mendota, Wisconsin, in July.
At this time there was a heavy growth of phytoplankters (Coelos-
phaerium sp., Aphanizomenon flos-aquae ) of more than 5000 organ-
isms per liter. At the surface, the oxygen content was 6.6 ppm. From
the surface flora the number of algae was irregularly reduced to
about 1000 per liter at 20 meters, where the oxygen content was only
0.1 ppm. In May of the same year in which the above readings
[ 40 ]
were made, the surface waters of Lake Mendota showed 28.5 ppm
of calcium and 5.0 ppm of carbonates. This lake lies in the limestone
region of the state and supports a eutrophic type of flora.
NITROGEN AND PHOSPHORUS
Special mention should be made of the significant roles of nitro-
gen in its various forms, and of phosphorus. The importance of these
nutrients has been measured, although somewhat incompletely. That
they are potential determiners of ultimate productivity is evidenced
clearly by the many limnological studies which have related high
nitrogen and phosphorus readings to luxuriant phytoplankton floras
(Harvey, 1926; Wiebe, et al, 1929; Domogalla and Fred, 1926).
The negative correlation of relatively high concentrations of these
elements with periods of phytoplankton minima provides inferen-
tial evidence of their use by green plants. That is, when nitrates
and phosphorus are low the phytoplankton population is high, the
nutrients being consumed and stored in the organisms. When the
phytoplankton decreases through an accelerated death rate and
distintegration occurs, the elements are released and their per-
centages in the chemistry of the lake rises. Nitrogen enters di-
rectly into the phytoplankton cycle. Nitrogen content, in turn, is
dependent upon several physical processes in and around the body
of water (run-off from agricultural lands, for example). The
nature of the bacterial flora, therefore, the chemistry of the drain-
age water, and the presence or absence of nitrogen-fixing bacteria
and algae, are some of the more important factors determining
nitrogen content. High oxygen content permits a rich plankton
flora, but when nitrogen is low or absent, many kinds of algae are
excluded from the flora. Some species of the Cyanophyta are
especially rich in proteins and require, therefore, a highly nitro-
genous medium. Thus a dense bloom of Aphanizomenon flos-
aquae or Microcystis aeruginosa would account for a great fluctua-
tion in the free nitrogen and nitrate content of lake water at different
periods of the year. Nitrogen fixation by some species of blue-green
algae (see De, 1939; Fogg, 1942; Fritsch and De, 1938; Hutchinson,
1944) is also involved here. This specific relationship to nitrogen
fixation is a reminder of the many reasons that limnological studies
which involve analyses of the biota should include specific, not
merely generic, determinations of the organisms concerned. Lim-
nologists not infrequently list only algal genera in the published
results of their studies, and this is not in keeping with the best
scientific procedure.
Here it might be well to recall that although nitrogen content,
carbon dioxide, phosphorus, and other elements are able to deter-
[ 41 ]
mine abundance of the algal flora, they also influence the variety, i.e.,
the kinds, of species present. As mentioned before, it does not follow
that because water is a universal and standard medium selectivity is
not being exercised rigorously. So clear-cut are some qualitative
selections operating in algal ecology that the phycologist is able to
use the presence of certain species or groups of species as indi-
cators of physical-chemical conditions in a body of water. Without
hydrogen ion determination equipment but just by observing the
quantity and quality of the algal flora, especially the phytoplankters,
the experienced worker can estimate the acidity or alkalinity (some-
what roughly to be sure) and the relative abundance of carbon
dioxide; can predict whether there is a rich or poor supply of nitrates;
and can tell something of other limnological features in a habitat.
BotrroM DEPosITS
Another way in which modification of phytoplankton quantity
and quality may come about is through the effects produced in
bottom sediments when organic matter decomposes. The composi-
tion of the silt, or ‘Gyttja’, determines the quality of the bacterial
flora, a group of organisms which is important in fixing the manner
and speed with which nutrient elements are returned to solution.
It is obvious, of course, that the kind and quantity of biota supported
in the water above, as well as on, the floor influence the physical and
chemical nature of the bottom sediments, which, in turn, acts in de-
termining the number and, to a certain extent the kinds of bacteria
in the sediments. Also, a lake bottom which supports dense popula-
tions of mollusks and midge larvae will be affected by the fauna.
In a lake where a luxuriant phytoplankton has become established,
especially in a cyanophycean lake, a great accumulation of nitro-
genous matter may result, As mentioned above, some of the blue-
green algae are nitrogen fixers, and many of them are great accumu-
lators of this element, Thus their physiology may result in an
ever-increasing supply of organic nitrogen in a lake. With bacterial
turnover, nitrogen appears first in one form and then another, and
eventually alters the chemistry of the water above bottom sediments
and so influences the biota.
Thus a closed cycle of interchanging and interacting phenomena is
seen to be operating within a lake. The processes which make up the
cycle are forever fluctuating. It is easy, therefore, to use the analogy
so often made between organic metabolism and the flux, reflux, and
pulsations within a body of water. The productivity of an aquatic
habitat is achieved by its ‘metabolism.’
[ 42 ]
QUALITY OF ALGAL FLORAS
The physical-chemical factors of the environment act not only in
selecting the quality of a flora, but sometimes the very quality deter-
mines the quantity. A single example to illustrate this is the fre-
quently encountered case of two lakes which support quite different
qualities of phytoplankton, one predominantly chlorophycean, the
other conspicuously cyanophycean. The factors which have acted
selectively to determine the qualities of these floras are well known
and include those mentioned above. The cyanophycean lake is high
in nitrogen, there is a relatively large amount of phosphorus avail-
able, the water is alkaline, with a pH ranging from 7.2 to 9.5, and
there is an abundance of free carbon dioxide or half-bound carbon ~
dioxide. This is the eutrophic type of lake and because frequently it
is relatively shallow the summer temperatures are high (25-30 C»):
Thus, although the characteristics of the hard water lake are far
from being detrimental to a chlorophycean flora, the combination of
factors is such that an ultra-favorable habitat is provided for the
blue-green algae and the diatoms. It is well known that the phys-
iology of many species in these groups is such that they are able to
carry on cell division and vegetative reproduction at an astoundingly
high rate. In fact, certain species of blue-green algae are so much
more successful in this respect than others even in the same group,
that they completely take over at the expense of competing forms.
Some pelagic Anabaena spp., Aphanizomenon flos-aquae, Gloeo-
trichia echinulata, Coelosphaerium Naegelianum, or Microcystis
aeruginosa, for example, either singly or together, may constitute
nearly 100 per cent of both the quantity and the variety of the phyto-
plankton because of their ability to reproduce rapidly. These organ-
isms are often responsible for water blooms, the excessive growth
being directly related to the quality of the flora.
In the chlorophycean lake, which frequently is the oligotrophic
type, there is a minimum of nitrogen and phosphorus, the water is
deeper than in the cyanophycean lake, there is proportionately less
water in contact with the bottom, and the temperature is generally
lower. Although the surface temperature may be the same in the two
lakes at a given time in mid or late summer, the chlorophycean lake
reaches its maximum temperature at a later date than the eutrophic
or cyanophycean lake because of the greater amount of water in the
hypolimnion and because of the greater time consumed in the
spring-summer overturn. With little carbon dioxide available, there
is no opportunity for a luxuriant growth of phytoplankters. The flora
that does develop here may contain many blue-green and diatom
species, but the greatest number of forms are chlorophycean. Even
[ 48 ]
under ideal conditions, green algae and most diatoms seldom, if ever,
form a bulky phytoplankton which can compare with the enormous
and overwhelming blue-green algal blooms frequently encountered
in hard water lakes, for their rate of reproduction is lower. Further-
more, green algae do not form sticky, floating mats of vegetation as
do many of the cyanophycean species. Hence, the quantity of the
algal vegetation is related to the kinds of plants that become estab-
lished in a lake.
It is well known that some oligotrophic lakes are practically bar-
ren of a microflora, as well as being almost entirely devoid of higher
aquatic plants. See Table 1, which shows a comparison of the nitro-
gen content and the quality of the plankton.
WATER BLOOMS
Serious economic problems and drastically unbalanced biological
conditions frequently arise in sluggish streams and in lakes which
are physico-chemically constituted to support a luxuriant water
bloom. This is particularly true in southern Michigan and Wisconsin,
as previously mentioned, where a body of water may become over-
grown with cyanophycean species, many of which have the habit of
floating high in the water. Their tremendous numbers cause floating
crusts and scums to form, wherein plants die quickly and disinte-
grate in the intense sunlight. The living plants and the increased
bacterial flora resulting from their decay after death deplete the oxy-
gen below the point required for fish (2-3 ppm) and other animals.
In my study of Iowa lakes I observed similar abundant blue-green
floras. After a few hot days and nights in summer, when the oxygen
was low in any case, a climax situation developed. The dissolved
oxygen dropped to zero around midnight, with the result that within
a few hours not a single living animal could be found in a lake with
such a water bloom. Even bottom organisms, adapted to low oxygen
supply, were killed, and there was a mass of dead Chironomus lar-
vae and microcrustacea near the shore and in the shallows of bays.
After such a climax, dead fish appeared within a few days, first float-
ing at the surface and then collecting in heaps along the beaches.
Thus enormous loss in game fish was sustained as a result of super-
abundant growth of blue-green algae.
I have some evidence that fish may be killed also by poisonous
substances, such as hydroxylamine, produced from the decay of pro-
teins with which blue-green algae are abundantly supplied. Fitch
et al. (1934) have described the poisoning of domestic animals by
toxic substances produced by certain species of these plants.
[ 44 ]
Excessive growths of phytoplankters may be costly in another
way; they may interfere both chemically and physically with the
operation of city water systems in which lakes, reservoirs, and filters
are involved. Copper sulphate (Moore and Kellerman, 1905; Domo-
galla, 1941; Prescott, 1938), chlorine, sodium arsenite (Surber, 1929;
Wiebe, 1930) and activated carbon are required to control algae or
to eradicate objectionable tastes and odors produced by them. Sand
filters are easily clogged by some species of algae such as Melosira
spp. and Aphanizomenon flos-aquae, and must be cleaned frequently.
Recreational sites are ruined and open bathing pools are rendered
unusable when phytoplankters take advantage of optimal lim-
nological conditions.
THE FOOD CHAIN
No single phase of the great cycle of events which occur with-
in a water habitat is of greater importance to the main problem of
productivity than the one which involves physiological activities
carried on by the algal portion of the biota, especially the phyto-
plankton. This is particularly true because the phytoplankton is
related to the food chain of aquatic animals, especially in lakes where
larger aquatic vegetation is scarce. Chandler (1944) has pointed this
out in connection with his studies of Lake Erie. No other group of
organisms in a body of water, unless it be the bacteria, can produce
such far-reaching effects by fluctuation in quality and quantity.
This leads to a consideration of the familiar position which phyto-
plankton and other forms of vegetation occupy in the food chain of
animals. That algae deserve the often applied term, ‘pasturage of
the sea,’ is seldom denied, and it is fairly well agreed that they hold
a basic position in the food cycle of both fresh and salt water
animals.
At the same time, many published studies, beginning with the
work of Pitter published in 1909 (see also Petersen and Petersen,
1911), have raised a question concerning the degree to which
aquatic animals are directly dependent upon phytoplankters. Hardly
any of these papers which have pointed out aquatic animals’ inde-
pendence of phytoplankton made claims that all the microfauna
subsists on nutrients of a non-particulate nature. Some students have
shown, rather convincingly, that at least certain zooplankters are
not directly supported by plants but are able, on the other hand,
to take nourishment from colloidal matter, organic debris, and, to a
minor degree, from substances in solution. In some such studies
nannoplankters have been shown to be the source of food when
[ 45 ]
larger phytoplankters have been excluded from the diet of experi-
mental animals such as Calanus (Clarke and Gellis, 1935).
Furthermore, other researchers have indicated that the concentra-
tion of dissolved and colloidal matter used in the culturing of lab-
oratory animals was greater than the normal concentration of these
substances in nature which is supposedly not sufficient to maintain
microfaunal populations. Thus the burden of direct support is
thrown back on the phytoplankton.
It is noteworthy that although the idea that phytoplankters are im-
portant in the food chain is apparently sound and generally accep-
ted, it is borne out by relatively few published scientific observations.
It is evident that there is much to be learned in this connection, and
the question certainly merits considerable attention both in the field
and in the laboratory. This is especially true, since so many predic-
tions and evaluations of productivity are based, in part, on the as-
sumption that phytoplanktonic components in the biota are of basic
importance in the food chain. A clear understanding of the exact
nature of this problem must be reached before the quality and quan-
tity of phytoplankton can be used as dependable indices of pro-
ductivity.
There are many published studies bearing out the correlation
between seasonal maxima in phytoplankton and peaks in microfau-
nal populations. The inference usually drawn from this correlation is
that the increased phytoplankton makes possible a larger microfau-
nal foraging population, which in turn would support a more
numerous macrofauna. But it is not known whether the microfauna
achieves maxima after a peak in the phytoplanktonic population
because it feeds directly on the plants, or because it is nourished by
particulate matter resulting from the plants’ disintegration.
Whatever the precise relationships are between the algae and the
eventual productivity of fish and other animal life, it is well known
that lakes with a luxuriant flora maintain a correspondingly dense
population of animals. This relationship is illustrated many times
over in lakes of the Michigan and Wisconsin area. Post Lake, Lang-
lade County, Wisconsin, for example, and Ocqueoc Lake, Michigan,
are highly productive and excellent for game fish, as many as eight
species occurring in the former. These are medium hard water lakes
and characteristically support a luxuriant vegetation of both algae
and larger aquatic plants. Chara spp. abound, and the phytoplank-
ton approaches the cyanophyte-diatom type. Near Post Lake is
Elcho Lake, in which perch is the only game fish on record, and
which has a poor phytoplanktonic flora and scarcely any larger vege-
tation, as compared with Post Lake.
[ 46 ]
In general, the lakes in the southern sections have the physical-
chemical qualities which permit the production of a bulk of vegeta-
tion of all kinds greater than that of lakes in the central and northern
regions. Hence the ultimate production of animal life is doubtless
greater on the whole in the southern lakes, although there are few
figures to support this. Crystal and Weber Lakes in Vilas County,
and Clear Lake in Oneida County, Wisconsin, are notable examples
of soft water lakes which are low in vegetation and are correspond-
ingly poor producers of fish.
Experimental studies have been made, and others are still in pro-
gress, on the effect on ultimate faunal production of increasing the
plankton by the addition of fertilizers. It has long been considered
good practice in Europe to improve fish production in nursery ponds
by this means, but few scientific evaluations have been made in this
country. Wiebe, Radcliffe, and Ward (1929) report that in ponds to
which fertilizers had been added, especially superphosphate, the
microfauna and algae showed a great increase in numbers over con-
trol ponds. (See also Ball, 1949.)
Although the total quantity of plankton in a lake may be large, it
is significant that the kind or quality of the plankters may be very
important in regulating production of fish. There may be sufficient
phytoplankton to support a rich microfauna on which fish feed. But
if there is a paucity of intermediate feeders, such as minnows or
other small predators, the food chain will thereby be interrupted,
‘om
£
AWATER PANTS XS
‘i 61.5
Y Bx
TER PLANTS
Cee ale
Figure 9. Diagrams illustrating the percentages of various types of food
used by two species of turtles. Left: Percentages by volume of various foods
consumed by western painted turtle (Chrysemys picta marginata). Right:
Percentages by volume of various foods consumed by the snapping turtle
(Chelydra serpentina). (Reproduced courtesy of Karl F. Lagler.)
[ 47 ]
for most of the larger fish cannot or do not feed directly upon the
microfauna and flora. (See Fig. 3.)
In addition to serving as food for the microfauna, either directly or
indirectly, phytoplankton makes up a large part of the food con-
sumed by several species of fish such as the gizzard shad, young
suckers, black bass fingerlings, and certain mollusks. Recently
I examined the alimentary tracts of several dozen snapping turtles
and found that in nearly every instance they were heavily packed
with algae and other plant fragments, to the exclusion of almost all
other types of food. Spirogyra crassa, Cladophora sp., and Cerato-
phyllum demersum L. were the principle plants eaten. Lagler
(1940) has published on the food of the snapping turtle and points
out that 36.2 per cent of the ingested material consisted of algae. He
found that 70 per cent of all turtle specimens examined had con-
sumed plant food. (See Fig. 9.) This is of interest because the
snapping turtle had been considered almost entirely carnivorous.
(See Lagler 1943. )
FACTORS THAT DETERMINE THE
CHARACTER OF LAKE FLORAS
A SUMMARY
1. The geological history of the region and the nature of the soil
over which the lake lies or which is drained by inlets.
2. The depth of the lake and the shape of the bottom—V-shaped or
U-shaped; presence or absence of shoals, shallow bays, etc.; extent
of the epilimnion, location of the thermocline; completeness of the
seasonal overturn.
3. Latitude; altitude (temperature and temperature range).
4. Relative amounts of oxygen and available carbon dioxide.
5. Nutrients in solution; salts; conductivity; pH; nitrogen content;
phosphorus.
6. Nature of the bottom; bacterial flora; rate of overturn of or-
ganic matter.
7. Biological enemies and competitors; parasites.
8. Chance distribution by agencies such as wind, waterfowl; isola-
tion by barriers from other bodies of water.
9. Light; turbidity; color of the water; rate of diffusion of rays in-
volved in photosynthesis.
Because of the interrelationships and the complete interdepen-
dence among some of the factors that determine the lake flora, it is
obviously impossible to select any one as of paramount importance
in a cause-effect analysis. Major interest here, however, is directed
[ 48 ]
toward phytoplankters and other chlorophyll-bearing organisms. As
is well known these, both directly and indirectly, contribute food to
the microfauna, which in turn provides nourishment for the benthic,
limnetic, and emergent faunas. (“Emergent’ refers to the animal life
which passes part of its life cycle in aquatic habitats, later emerging
to join the land fauna.) In addition to their role in the food chain,
chlorophyll-bearing organisms supply shelter and breeding places
for many kinds of aquatic animals, and they also have important
limnological bearings in that they alter the chemistry of the water,
interfere with illumination, affect color, etc.
Some of the phytoplankton (members of the Cyanophyta) are
able to fix nitrogen and so affect the supply of nitrates and the nitro-
gen cycle. Information on the nitrogen-fixing activities of the aquatic
algae is meager, but evidence indicates that some forms play a more
important role than is generally recognized in this connection.
The quantity of phytoplankton is determined, in part at least, by
the abundance of available carbon dioxide contributed by the atmos-
phere, by half-bound carbon dioxide from bicarbonates, and from
springs, etc. Carbon dioxide is, of course, continually being supplied
also by respiration in all forms of life, including bacteria. At the
same time all life draws upon dissolved oxygen, which diffuses from
the atmosphere or is contributed as a result of photosynthesis.
Other elements necessary for plants, such as phosphorus and nitro-
gen, are supplied through drainage and by the continual overturn of
organic matter by bacteria and other destructive organisms. Var-
ious edaphic, limnological, and geological factors which determine
water chemistry, contour of the bottom, and the presence or absence
of seasonal overturns of lake water. These, in turn, help to determine
the nature of the bacterial flora, and hence the kinds and amounts of
decomposition products and the completeness with which the or-
ganic matter is reconverted.
Lakes and streams may receive run-off water from agricultural
lands and effluents of waste matter which are richly supplied with
critical nutritive elements and compounds. These become incorpo-
rated in the food cycle.
To an unknown extent, substances produced by bacterial decom-
position also furnish nutrients to the microfauna. Also unknown is the
extent to which nitrates for the use of green plants are formed by
nitrifying bacteria. Information is not at hand which will permit a
definite statement concerning this portion of the nitrogen cycle, but
there is ample justification for assuming that nitrification by bacteria
occurs under favorable aquatic conditions as it does in terrestrial
soils.
[ 49 ]
MORPHOLOGICAL TERMS
ILLUSTRATED
PLANE SURFACES
|] trapezoid subhexagonal
quadrate
oblong
ovate ag
lanceolate
aaa
rhomboid spatulate; truncate-spatulate
[ 52 ]
REGULAR SOLID ForMsS
CPC
id
orbicular depressed globose ae
obovoid
oblong-ovate
discoid i. pyramidal
we Ble:
cylindrical
fusiform; naviculoid lenticular dolioform
[ 53 ]
IRREGULAR SOLID Forms
as
S 3
renif orm lunate
sigmoid —_semilunate
ane
arcuate cordiform
planoconvex
) pyriform
G clavate i
saccate panduriform
[ 54 ]
IS
vermiform
citriform
ventricose
terebriform
TERMINAL FORMS AND STRUCTURES
sagittate truncate
uncinate rostrate; rostrate-capitate calyptrate
[55 ]
CHLOROPLAST FoRMS AND ARRANGEMENTS
axial
laminate
radial
CELL WaLL Forms AND STRUCTURES
) 4
plane cross walls replicate cross walls
laminated walls colligate
[ 56 ]
SURFACE CHARACTERS
SS la
SOE VT
ee ES
%00090005> Tugose
punctate 095000. 002 PSs
© CO000m6 O°
Se
a ean
CPALLOAON
verrucose
ST verrucae
S S23
can
a)
reticulate
costate
plicate zonate
[ 57 ]
MARGINAL CHARACTERS
crenate
undulate
dentate
imcise
convolute
sinus
[ 58 ]
SHEATHS
U
.
’
,
:
o ’
4 ° .
. ° .
a 8 »
» .
‘ ts °
x . a
: we 3
\ as :
: a 0
: “i :
S v Py
:
: e
: *
: e
> .
RQ .
: . :
: oS
. . e
: . 5
1 . .
: .
~ .
t .
+ .
‘= ‘
Hy e .
. 5 . .
a . . .
“| Le . .
s " 5 .
2 wie . .
= ore . .
® .° . : .
wile toe 5
° 7 :
sane ae :
~ ‘ re
. . Vv .
’ .
. . 4
. . :
. .
° . ©
. . :
confluent
diffuent
CELLULAR EXTENSIONS
flagella
rhizoids setae sheathed seta
[59 ]
BRANCHED FILAMENTS
monaxial
penicillate
multiaxial
intricate irregular
[ 60 ]
BRANCH CHARACTERS
\P
bilateral
unilateral
bifurcate
dendroid
adnate
divaricate dichotomous
[ 61 ]
FmAMENTOUS COLONIES
uniseriate
multiseriate
Boreee,,
“tee,
My
.
scalariform
pseudofilamentous
[ 62 ]
circinate fliform flagelliform
moniliform catenate caespitose
[ 63 ]
NON-FILAMENTOUS COLONIES
700000:
(00000:
00000:
00000:
00000;
rectilinear
pulvinate
clathrate
Faligse lacunose
[ 64 ]
Systematic Account
Structural terms are illustrated in the preceding section and are
defined, together with other technical terms, in the Glossary.
DIVISION CHLOROPHYTA
Plants belonging to this group are characterized by grass-green
chloroplasts, one to many in each cell or protoplasmic unit. In most
forms the chloroplast contains one or more pyrenoids, which ac-
cumulate starch as a food reserve. Even in plants which do not pos-
sess a pyrenoid, presence of starch makes possible the use of the
iodine test for separating doubtful forms from those Chrysophyta
which are similar in general appearance.
The cell wall, which is firm in most genera, is composed of cellu-
lose and pectic compounds. There may be, also, a mucilaginous outer
layer.
‘See G. M. Smith (1933, 1938) and F. E. Fritsch (1935) for a
discussion of the reproduction and the taxonomy of this division;
Collins (1909, 1918, 1918a) on the taxonomy; Blackman (1900),
Blackman and Tansley (1902), and Fritsch (1916) on the phylogeny.
The modern interpretation of this division recognizes two classes,
Chlorophyceae and Charophyceae.
CLASS CHLOROPHYCEAE
This class, commonly known as the green algae, includes a great
variety of forms: unicells (sometimes motile), simple or well-
organized colonies, simple or branched filaments, partitioned coeno-
cytes, and true coenocytes (filaments without cross walls). The chief
evolutionary series in the Chlorophyceae begins with the motile uni-
cells of the Volvocales.
The methods of reproduction, both asexual and sexual, vary
greatly within the several orders. In some orders, the sexual repro-
ductive methods and organs are unique and serve as a basis for
classification. This is particularly true for the Zygnematales (Con-
jugales), the Oedogoniales, and the Siphonales.
See the authors mentioned above, as well as Oltmanns (1922), for
an account of reproduction and life histories in the Chlorophyceae.
[ 65 ]
Key to the Orders
In the Keys, asterisks indicate orders, families, genera, or species
that are likely to be found in the central Great Lakes region but
have not been reported there to date.
Ile
1.
Motile in the vegetative condition; eee 2 or 4, ae 8, equal in
length; organism 1-celled or colonial = 2 VOLVOCALES
Not motile in the vegetative Gonditigii ae Aoi eel (Lhe 2
2. Cells embedded in copious mucilage (which is either homogeneous or
10.
lamellated), united in colonies of indefinite shape (see Apiocystis,
however ), or in tubes forming gelatinous strands (pseudofilaments ), or
bullate masses (See mucilage-invested Chlorococcales also.); some
forms unicellular or forming dendroid colonies which are epiphytic
or epizoic; cells frequently possessing false flagella (pseudocilia),
returning to a motile condition without resorting to reproductive
(Se) | SR aneeiaedie ph iret Se ae ema Ce Oo) Eee TETRASPORALES
ERE aTits FOL AS a bOVe wet. sae cane en Oe Ee ene ee eee eee 3
. Plants filamentous, composed of cells adjoined end to end in definite
Series:sometimes, mterrupteds ss) 82. Uae stk Passa h ee Wn) CA Ne ee oe oe 4
- Plants not composed of cells arranged to form filaments; unicellular or
colonial or, if filamentous, occurring as coenocytes without cross walls_15
. Filaments unbranched; attached or free-floating... 5
. Filaments with Beaneties! the branches sometimes closely appressed, form-
ing spseudoparenchymatous iMmagees 2. Awe ee ee 13
. Filaments composed of a single series of cells_.-__-______-__-____- 6
. Filaments composed of more than | series of cells; cells adjoined; thallus
a hollow tube or a ribbon-like or frond-like expansion 12
. Chloroplasts 1 to several, large, in the form of spiral bands, stellate
masses, or broad plates; pyrenoids oe reproduction by conjuga-
tion _ ae E3 _ZYGNEMATALES
d Chloroplasts parietal, plate- aes nee likes or eal pads Se (in the latter
case usually many in a cell); reproduction by iso- or heterogametes___. t
. Cells with a single, parietal, plate-like or broadly discoid chloroplast;
cells cylindrical; filaments uniseriate or multiseriate ULOTRICHALES
3 Gells: withyother ‘types vot chloroplasts =" == =a se ee eee 8
. Plants composed of long, cylindrical, coenocytic and thin-walled units,
containing numerous disc-like chloroplasts arranged in narrow annular
bands; cross partitions with knob-like thickenings; reproduction usually
OOPAMNGUS A teates oo eS Pe See ad eet Dea ae SPHAEROPLEALES
sa P lamtsenO tras a DOV Geet a a eee wes ieee ee) ee ee 9
. Cells cylindrical, ovate or subspherical, each surrounded by lamellate
mucilage; frequently losing their uniseriate arrangement and forming
palmella stages; chloroplast massive, filling the cell, obscured by many
starch grains; sexual reproduction oogamous__...___. CYLINDROCAPSALES
. Cells cylindrical, not surrounded by lamellate mucilage; chloroplast
Parietal ot See ea MS Bate Dg Ci ied ua aa, ec ee 10
Cells with parietal, net-like or sheet-like chloroplasts, which usually cover
both the end and lateral walls; wall composed of two sections which over-
lap in the midregion, forming H-shaped pieces upon fragmentation;
pyrenoids lacking; sexual reproduction unknown... MICROSPORALES
[ 66 ]
10. Cells not showing H-shaped sections upon dissociation; pyrenoids present;
sexual’ reproduction} kno Wn =e aeeee es eee) 1l
11. Cells coenocytic, cylindrical, with thick walls; chloroplast a dense, parietal
net with pyrenoids at the intersections of the meshwork, or with many
ovoid parietal discs; walls without ring-like scars at the anterior end of
[een 6 =) | Gye Se Reece ee eee en kt Ves ls CLADOPHORALES (in part)
11. Cells not coenocytic, cylindrical but usually perceptibly larger at the an-
12. Plant an expanded plate or tubular strand formed by several series of cells;
chloroplast a parietal plate similar to that in the Ulotrichales...."uLVALEs
12. Plant an expanded sheet, composed of several series of cells; chloroplast a
Stellate qaxktal OOCyet nse 25 ee mee es se ta, __ *SCHIZOGONIALES
13. Filaments composed of cylindrical or rectangular, uninucleate cells which
have a single, plate-like and parietal chloroplast; branches terminating in
setae, or with cell walls bearing hairs or bristles which usually are not
distinctly bulbousat the base: 2 CHAETOPHORALES
13?yPilaments notas ‘above ee SITE 1 alae 14
14. Filaments composed of cylindrical, coenocytic cells which may become
attenuated toward their apices; setae and bristles wanting .________
Ree eeeeses | he ee ee _ CLADOPHORALES a(S AED)
14. Filaments composed of cells which are larger at the anterior end; bearing
setae with much-enlarged, bulbous bases; reproduction oogamous, the
female gametes produced in conspicuously swollen gametangia
ale EPC sa Bit Pg 8 eo ee OEDOGONIALES (in part)
15. Plant composed of long, branched coenocytic strands without cross walls
except where reproductive structures are cut off... SIPHONALES
15. Plant a single cell, or a colony of definite or indefinite form; cells various
in shape, spherical, pyramidal, or polygonal, incapable of division in the
vegetative state; reproduction by autospores, zoospores, or isogametes.
(Compare with Tetrasporales, in which Chlamydomonas-like cells form
colonies in mucilage that resemble some members of this order.)
____..... CHLOROCOCCALES
ORDER VOLVOCALES
In this order both vegetative and reproductive cells are motile.
The prototype of the Chlorophyceae is to be found among the
1-celled members, from which colonial Volvocales, as well as other
orders of green algae, are thought to have evolved. There may be
2, 4, or rarely 8 flagella. Usually there is a conspicuous pigment-spot.
Although a few colorless forms are recognized, by far the majority
of these organisms have a cup-shaped, parietal chloroplast (rarely
stellate or axial) with one or more pyrenoids. Reproduction is by
cell division, by zoospores (formed 2—8 in a cell), by isogametes,
or by heterogametes, egg and antherozoids being formed in sexual
reproduction among the more advanced colonial genera.
[ 67 ]
Key to the Families
1. Cells solitary, naked, i.e., inclosed only by a membrane; cell wall lack-
11) © eae eae een ce erees SAND Cane mmr re sn ask Ae el: 5 POLYBLEPHARIDACEAE
1. Cells possessing a definite wall and sometimes a mucilaginous sheath;
Solitary or united inicolonies:=)2 252 Bt ee ie eed, 2
2enGellstsolitany' 23322 ee Ue ak eS 8 oe eee a A eS) Seen 8
2 Gellsmunited int colonies 222 * 2a st te ee ee oe ee 5
3. Wall bivalved, the cells compressed and the halves of the wall adjoined
along their lateralimargins 92.3 ee * PHACOTACEAE
8: \Wallenot bivalved:' cells not fattened 3 eee 4
4. Cells with protoplasts located at some distance within the cell wall and
connected to it by radiating cytoplasmic
GERAIS: Peace. cee cece ere ete Se ecanrn ett HAEMATOCOCCACEAE (in part)
4. Cells without radiating cytoplasmic strands. CHLAMYDOMONADACEAE
5. Cells with many radiating cytoplasmic processes connecting the proto-
plast with the cell wall................. Perce HAEMATOCOCCACEAE (in part)
5. Cells without such radiating protoplasmic processes _________-_---------_-- 6
6. Cells united to form flat or globular colonies, evenly dispersed, although
sometimes closely arranged within colonial mucilage_______. VOLVOCACEAE
6. Cells compactly united in tiers of 4 with their anterior ends all directed
the same way; gelatinous sheath lacking —.._._______. SPONDYLOMORACEAE
FAMILY POLYBLEPHARIDACEAE
The chief characteristic of this family of unicellular individuals
is the lack of a cellulose wall, the protoplast being inclosed by a
membrane only. The cells have 2-4-8 anterior flagella of equal
length, with contractile vacuoles sometimes present at their bases.
A red pigment-spot is normally present. The chloroplast varies in
form among the different members; usually it is a parietal cup con-
taining a pyrenoid. Of the 7 genera reported from North America
only 1 is known from this region at present.
PYRAMIMONAS Schmarda 1850, p. 9
Cells hemispherical or obpyriform, broadest at the anterior end,
which is depressed and 4-lobed; 4 flagella attached in the apical
depression, with 2 contractile vacuoles below their point of attach-
ment. Chloroplast a parietal cup with a pyrenoid in the posterior
portion.
Pyramimonas tetrarhynchus Schmarda 1850, p. 9
Pl. 1, Figs. 1, 2
Cells pyriform with the anterior end conspicuously 4-lobed; fla-
gella attached close together in the apical depression. Chloroplast a
parietal cup with 4 lobes. Cell 12-18, in diameter, 20-28, long.
Wis.
[ 68 ]
FAMILY CHLAMYDOMONADACEAE
The unicellular organisms which compose this family have a
smooth cellulose membrane in 1 piece. There are 2 or 4 flagella,
equal in length, and 2-4 contractile vacuoles at the anterior end of
the cell. In most forms the chloroplast is cup-shaped and contains 1
to several pyrenoids (posterior or scattered) and a red pigment-spot
laterally placed, usually anterior.
Members of this family should be compared with those of the
Phacotaceae in which the cell wall is in 2 valve-like pieces that
adjoin along the lateral margins; and with the Haematococcaceae,
in which there are radiating protoplasmic processes extending from
the cytoplasm to the cell wall.
There are 10 genera of this family reported from the United States,
but only 2 of these have appeared in our collections.
Key to the Genera
COUS With AAC Cline ae eet eeieee eee eS pa Ae ed Carteria
Cells with 2) flagella st ped LU hy, ek LS Chlamydomonas
CHLAMYDOMONAS Ehrenberg 1835, p. 288
Cells ovoid, ellipsoid, or spherical, sometimes with 1 or 2 apical
papillae, from which the 2 flagella arise; often with a narrow or wide
mucilaginous sheath. Chloroplast a dense, padded body occupying
the entire cell, or a thin parietal cup (in a few species H-shaped or
stellate); pyrenoids 1 to many, basal or bilateral and scattered;
pigment-spot lateral and anterior, rarely median; 2-4 apical contrac-
tile vacuoles usually discernible.
Species of this genus have the habit of coming to rest, losing their
flagella, and entering upon a quiescent phase. Vegetative cell divi-
sion continues, ordinarily accompanied by the secretion of mucilage,
so that amorphous gelatinous masses are formed which contain
many nonmotile cells. This is known as the palmella stage. Unicellu-
lar or colonial algae in which the cells are ovate or globose and
which have cup-shaped chloroplasts (e.g., Gloeocystis) should be
compared, in making identifications, with this palmelloid expression
of Chlamydomonas.
Key to the Species
1. Cells inhabiting the empty loricas of Dinobryon C. Dinobryonii
uy Cells not inhabiting the loricas of Dinobryon—..._____._._.. 2
2s Gells with) axial pyrenoids, basal or median 3
2. Cells with 1 or more pyrenoids, lateral or scattered..........0.00.00.00.000.0000. whet |
Se Cells without anvapicaly papilla. = 6 C. globosa
Bepoellsawitind or more. apical papillae. 22-22 4
[ 69 }
4, Cells epiphytic, on the mucilage of Microcystis...» C. epiphytica
4. Cells not epiphytic on colonies of Microcystis
5. Cells globose, with 2 contractile vacuoles in
thiel anterior, @niG-see sie nae DL eee eae Sa ee C. pseudopertyi
oo Cells; ellipsoid’ or, 10 vate eset Oo. ME ie SUPER ee a ee ee a 6
Guibapillaxsharplyspomtedes ere. = = 1 ce We ee ace eceeeree aeen erat Went. C. Snowii
6. Papilla broad and truncate; cell often truncate
and angular at the anterior end) 3 4) ae eee C. angulosa
i, (Cellsewith.2 apical papillae: == 2222 eee C. sphagnicola
i. \@ells without; papillae or with only 12s = eee ee eee 8
SiiG@ellsvellipsoidy withet oyrenoid = 2 sen C. mucicola
8. Cells ovate or cylindrical, with many pyrenoids fe)
9. Cells ovoid, without a papilla; pyrenoids
many. W216). lateral: We. 2s ee C. polypyrenoideum
9. Cells cylindrical to subcylindrical, with a papilla;
PY LEW OL Sie Wy na eeaeee ns Dees eet oa ae eee NL Ee ae Oe eee C. Cienkowskii
Chlamydomonas angulosa Dill 1895, p. 337
PI Bigs3
Cells broadly ovoid to cylindric, often truncated anteriorly and
with a prominent papilla. Contractile vacuoles 2, below the flagella,
which are as long as or slightly longer than the cell body. Chloro-
plast a massive, parietal cup with a large angular pyrenoid in the
base; pigment-spot anterior and lateral. Cells 11-13-(15), in dia-
meter, 15-18-20, long.
Tychoplankter. Wis.
Chlamydomonas Cienkowskii Schmidle 1903a, p. 349
Pl.1, Fig. 4
Cells cylindric to subcylindric with a prominent apical papilla,
below which are 2 contractile vacuoles. Flagella shorter than the cell
in length. Chloroplast a thin, parietal, cylindrical cup with several.
pyrenoids. Pigment-spot anterior and lateral. Cells 10-11 in dia-
meter, 20-25, long.
Our specimens are shorter than usual for this species, but the shape
of the cell, the form of the chloroplast, and the number of pyrenoids
are in agreement.
Tychoplankter. Wis.
Chlamydomonas Dinobryonii G. M. Smith 1920, p. 91
PIV igo
Cells ovoid to pyriform, without an anterior papilla, inhabiting the
empty loricas of Dinobryon; flagella 6-8» long. Chloroplast disc-
[ 70 ]
shaped to hemispherical, lying either at the base of the cell or along
the lateral wall; pigment-spot lacking (?). Cells 2-3, in diameter,
3-5y long.
Rare to common in several lakes. Wis.
Chlamydomonas epiphytica G. M. Smith 1920, p- 91
Plol, Figsi6,7
Cells spherical to nearly pyriform, anteriorly narrowed into a
papilla-like beak. Cells becoming non-motile, adherent to the colon-
ial mucilage of Microcystis without losing flagella. Chloroplast a thin
parietal cup; pigment-spot lacking. Cells 7-8. in diameter, 8-9u
long.
Common in several lakes. Wis.
Chlamydomonas globosa Snow 1903, p. 389
BLAS Wigs. 8.9
Cells broadly ovoid to globose, inclosed in a hyaline, gelatinous
sheath; anterior papilla absent. Chloroplast a dense parietal cup
with a basal pyrenoid; 1 contractile vacuole in the anterior end of
cell; pigment-spot lens-shaped, supramedian in position and lateral.
Cells 5-7, in diameter, 10-19, long.
Tychoplankter; common. Mich., Wis.
Chlamydomonas mucicola Schmidle 1897a, p. 17
Pl. 46, Fig. 20
Cells narrowly elliptic or narrowly ovoid, attenuated to a blunt
point anteriorly, broadly rounded posteriorly. Flagella 114 times the
body in length. Chloroplast a lateral plate with a single large pyre-
noid; pigment spot and 4 contractile vacuoles in the anterior end.
Cells 3-4, in diameter, 6-10, long.
Tychoplankter. Mich.
Chlamydomonas polypyrenoideum Prescott 1944, p. 348
PUA Figs, 10.11
Cells ovoid to ellipsoid, without an apical papilla; gelatinous
sheath lacking (?). Chloroplast a dense parietal cup with a deep
median invagination; pyrenoids many (12-16), scattered; pigment-
spot not observed. Cells 8-10 in diameter, 9-12» long.
Rare in euplankton. Wis.
[71]
Chlamydomonas pseudopertyi Pascher 1927, p. 214
Blah ig 2
Cells globose, with a prominent, hemispherical papilla. Chloro-
plast cup-shaped, dense in the basal portion; 2 anterior contractile
vacuoles; pyrenoid posterior; pigment-spot lens-shaped, anterior and
lateral. Cells 12-18—(27), in diameter.
Tychoplankter; rare. Wis.
Chlamydomonas Snowii Printz 1914, p. 18
Pl. 1, Figs. 13, 14
Cells narrowly ovoid to ellipsoid, with an anterior beak. Chloro-
plast a parietal cup, dense in the posterior portion; 1 pyrenoid,
centrally located, palmella stages frequent. Cells 6.5-8» in diameter,
10-15, long.
Tychoplankter; rare. Mich., Wis.
Chlamydomonas sphagnicola Fritsch & Takeda 1916, p. 373
Pl. 1, Figs. 15, 16
Cells broadly ovoid to subglobose, broadly rounded both anteriorly
and posteriorly, with 2 prominent papillae at the anterior end; the
protoplast separated from the wall, also having pointed apical papil-
lae. Chloroplast a parietal sheet, granular, covering most of the cell
membrane (in our specimens more dense toward the basal part);
pyrenoids several (4-6), scattered; pigment-spot prominent, anter-
ior, nearly median. Cells 15-18, in diameter, 21-29, long.
This species commonly forms resting stages during which 2-4 cells
are formed within the old mother cell.
Common in Sphagnum bogs; tychoplanktonic in lakes. Wis.
CARTERIA Diesing 1866, p. 356
Cells oval or round in cross section, elliptic, oval, or cordiform in
front view, with a definite cell wall; furnished with 4 long flagella.
Chloroplast parietal, cup-shaped, with or without a pyrenoid;
pigment-spot usually present, at the anterior end of cell.
Species in this genus should be compared carefully with Chlamy-
domonas spp. Carteria in the past has been placed in a separate fam-
ily (Carteriaceae), mostly on the basis of the number of flagella.
Only 2 species have appeared in our collections.
Key to the Species
Cells cordiform, broadest at the anterior end,
Awihich: is: CONCAVG =.= eres ee) es ee C. cordiformis
Cells ellipsoid or ellipsoid-cylindric, narrower, and
papillaterat. the anterioniend == ee C. Klebsii
Carteria cordiformis (Carter) Diesing 1866, p. 356
PI. 1, Fig. 20
Cells cordiform, broadest at the anterior end, which is deeply de-
pressed, the 4 flagella arising within the depression; somewhat smal-
ler but broadly rounded posteriorly. Chloroplast a thin parietal cup,
with 1 basal pyrenoid. Cells 16, in diameter, 12-20, long.
Rare in tychoplankton. Mich., Wis.
Carteria Klebsii (Dang.) Dill 1895, p. 353
Pl. 1, Figs. 17-19
Cells ellipsoid or ellipsoid-cylindric, narrower at the anterior end,
which is sharply rounded with a papilla around which the flagella
arise. Chloroplast a massive parietal cup, with 1 basal pyrenoid;
pigment-spot lacking. Cells 5-10y in diameter, 8-16, long.
Rare in tychoplankton. Wis.
FAMILY PHACOTACEAE
The flattened, unicellular biflagellates of this family, with their
two-valved walls, especially Phacotus lenticularis (Ehrenb.) Stein,
and Pteromonas angulosa (Carter) Lemm., are to be expected in
the central Great Lakes region, but no member of the family has
appeared in our collections.
FAMILY VOLVOCACEAE
Members of this family are colonial. The cells are characteristically
biflagellate and Chlamydomonas-like and are so arranged as to form
globose or obovoid hollow colonies or flat plates. There may be as
few as 4, or as many as 25,000, cells in a colony. Cell sheaths may
be distinct or confluent with the colonial mucilage.
In most genera the cells of the colony are alike in size and func-
tion, but in the more advanced forms there is a certain amount of
specialization. In Pleodorina, for example, a few of the cells are dis-
tinctly smaller than others and have no reproductive function. In
Volvox some cells enlarge and become female gametes, whereas
others undergo division to form plates of numerous, small anthero-
zoids. Both kinds of gametes may be produced in the same colony
(monoecious) or in separate colonies (dioecious) according to spe-
cies. See Smith (1933, 1938, 1944), Fritsch (1935), and Pascher
(1927) for the morphology, reproduction, and taxonomy of this
family.
[ 73 ]
Key to the Genera
le* Wolony/sphericaliorsGyoid 229 )8. 21s et ed ge) 2
1. Colony a flat or twisted plate with cells in 1 layer___-_-____ 5
2. Colony spherical, ovoid, or obovoid, containing 256 or fewer cells 8
2. Colony a hollow sphere, containing from 500 to several
thousand cells wm be lauretee Lars i ihe 1S eal ee SM Dye NA RUN hee Volvox
3. Colony containing from (32)—64 to 256 cells, which are of 2
SIVA SNA en eg ees ote eg PRE Ren i ae aces ak Sek ee ad Pe Re A SE Pleodorina
3. Colony containing less than 64 cells, all similar in size_t 4
4. Colony ovoid or obovoid, composed of spherical or ellipsoid cells
arranged at some distance from one another and often
appearing in transverse tiers _ ___. Eudorina
4, Colony ovate, composed of pyriform cells compactly ‘arranged _ = Pandorina
5. Colony a flat, rectangular plate of from 4 to 32 cells Gonium
5. Colony horseshoe-shaped, slightly twisted on its
Axis MCOMPOSECLO lel GNOIaa Cel IS eee eon ee Ee *Platydorina
GONIUM Mueller 1778; emend. Prescott in
Prescott, Silva, & Wade 1949, p. 84
A free-swimming, plate-like, quadrangular colony of 4-32 ovate,
ovoid, pyriform, or bilobed cells so arranged within a gelatinous
envelope that a rectangle of 4-8 central cells is inclosed by a periph-
eral series of 12-24 individuals; the long axis of the central cells at
right angles to the plane of the colony, but axis of peripheral cells
radial to the center of the colony. Cells interconnected by fine proto-
plasmic processes; individual envelopes adjoined by stout processes
with those of neighboring cells, so that oval or quadrangular inter-
stices are formed in the colonial mucilage. Flagella 2, attached in
the narrow anterior end just above 2 contractile vacuoles. Chloro-
plast a parietal cup with 1 or 2 pyrenoids; pigment-spot usually large
and conspicuous, lying laterally in the anterior end. Sexual repro-
duction by the division of the vegetative cells into 4-16-(382?) iso-
gametes which fuse in pairs, the quadriflagellate zygote becoming
a thick-walled resting spore.
Key to the Species
1. Colony 4-celled, with anterior ends of cells all directed outward __ G. sociale
1. Colony 16-32-celled (rarely 4-celled); the outer cells with flagella directed
in the transverse plane of the colony, the inner cells with flagella directed
at right angles) to: the:trausverse plane. 5 <0) 22.3 2 ees 2
2, Cellsvellipsoid Or;subsphericalest ss. e See teaees eee ee G. pectorale
2. Cells ovoid-pyriform, narrowed anteriorly... G. formosum
Gonium formosum Pascher 1927, p. 418
Colony of 16 ovoid-pyriform cells inclosed in relatively wide indi-
vidual sheaths which are joined to neighboring sheaths by narrow
and relatively long arm-like extensions so that each of the inner 4
[74 ]
cells is connected with 6 other cells, leaving a large circular open
space in the center of the plate. Chloroplast a parietal cup, thickened
at the base, which incloses a pyrenoid; pigment-spot anterior and
lateral. Cells about 10, in diameter, 1-114 times as long as wide.
Mich.
Gonium pectorale Mueller 1773, p. 60
PI. 1, Fig. 21
Colony of (4)-8-16 ellipsoid, subspherical or sometimes ovoid
cells closely arranged in a flat, quadrangular plate, usually with 4
inner cells bordered by a series of 12 marginal ones which have their
anterior ends projected outward and parallel with the plane of the
colony, the inner cells directed at right angles to the plane. Cells
inclosed by individual sheaths, which are connected to neighboring
sheaths by very short processes. Cells 5-15 in diameter.
Associated with other Volvocales in hard water rich in nitrogen.
Mich., Wis.
Gonium sociale (Duj.) Warming 1876, p. 82
Pl. 1, Fig. 22
Colony of 4 ovoid cells, all directed outward, inclosed by colonial
mucilage which has a central rectangular perforation. Cells 10-15.
in diameter, 12-20, long.
This species, like G. pectorale, is often found in barnyard pools,
watering troughs, and sloughs where nitrogen content is high.
Eu- and tychoplanktonic; in hard water lakes. Mich., Wis.
PANDORINA Bory 1824, p. 600
Colony ovate or obovoid, composed of 8-16—(32) globose or pyri-
form cells compactly arranged and inclosed by a common gelatinous
envelope; cells with the broad anterior end directed outward. Chlor-
plast a parietal cup with 1 basal pyrenoid; pigment-spot anterior and
lateral. Flagella 2, arising from the anterior end of the cell and
diverging widely after emerging from the colonial envelope; the
colony swimming in a rolling or tumbling fashion; vegetative re-
production by the simultaneous division of each cell in the colony
to form as many colonies; sexual reproduction by isogametes formed
in groups of 8 or 16 by the partition of some or all of the cells of
the colony.
Pandorina morum (Muell.) Bory 1824, p. 600
Pl. 1, Fig. 23
Colony usually distinctly ovate, as much as 220y in diameter.
Cells pyriform, crowded, usually 16 in number, 10—15y in diameter,
12-17». long.
[75 ]
Common in the plankton of both hard and soft water lakes but
more frequent among dense growths of algae in shallows, especially
in water rich in nitrogenous matter. Mich., Wis.
EUDORINA Ehrenberg 1832b, p. 78
A free-swimming ovate, obovoid, or globose colony, in which
16-32-64 ovoid or ovate cells are inclosed within a gelatinous en-
velope. Cells sometimes arranged in transverse series, sometimes
evenly disposed throughout the colonial mucilage; 2 long flagella
present, which diverge widely beyond the periphery of the colonial
envelope; cells often with 1 or 2 anterior beaks or papillae where
the flagella arise; 2 minute contractile vacuoles at the base of the
flagella. Chloroplast cup-shaped and parietal, with 1 to several pyre-
noids. Red pigment-spot laterally placed at the anterior end of the
cell. Cytoplasmic strands connecting the cells sometimes in evidence.
Anisogamous sexual reproduction by small antherozoids and _bi-
flagellate female gametes similar in size to vegetative cells.
Eudorina elegans Ehrenberg 1882b, p. 78
Pl. 1, Figs. 24-26
Colony spherical or ovate with 16-82 ovoid cells evenly disposed
within a gelatinous envelope, or arranged in transverse series, the
cells usually lying near the periphery of the envelope but sometimes
crowded toward the interior. Cells 10-20, in diameter; colonies up
to 200u in diameter.
This species shows a great deal of variation in the size and shape
of the colony. In liquid-preserved material the envelope shows the
form of E. unicocca G. M. Smith, with posterior mammillate pro-
jections.
Common in euplankton of hard water lakes. Mich., Wis.
PLEODORINA Shaw 1894, p. 279
A free-swimming globose colony of 32-128 (rarely 256) spherical
or ovoid cells arranged at the periphery of a gelatinous colonial in-
vestment. Cells differentiated and of 2 sizes, the purely vegetative
(toward the posterior pole) being about half the size of the repro-
ductive (anterior) cells. Chloroplast a parietal cup, with 1 or more
basal pyrenoids. Pigment-spot lateral and anterior. Flagella, 2, at-
tached at the anterior end of cell, just above 2 contractile vacuoles;
the colony swimming in a rolling or tumbling fashion. Sexual repro-
duction anisogamous.
[ 76 ]
Key to the Species
Colony with 64-128 cells about half of which
are smaller anGy vegetative. =e es eee en ee nk P. californica
Colony with 32-64 cells, only 4 of which are
Smiallensands vecetacives <2 2s tek eee ea P. illinoisensis
Pleodorina californica Shaw 1894, p. 282
Pl. 2, Fig. 1
Colony spherical, containing as many as 128 globose cells, about
half of them vegetative and half reproductive in function, the latter
distinctly larger than the former. Flagella subparallel within the mu-
cilage, diverging widely outward. Vegetative cells 6-14 in diam-
eter; reproductive cells up to 34u in diameter.
Rare in the plankton of several lakes; occasionally abundant in
water rich in organic matter. Mich., Wis.
Pleodorina illinoisensis Kofoid 1898, p. 274
[Eudorina illinoisensis (Kofoid) Pascher]
Pl. 2, Fig. 8
Colony globose, containing 32-64 cells, 4 of which are small and
vegetative, and located toward the posterior pole of the colony.
Vegetative cells 8-10 in diameter; reproductive cells 14-20u in
diameter.
Rare; found in a fish hatchery pond. Wis.
VOLVOX Linnaeus 1758, p. 820
Colony free-swimming, spherical or ovate, composed of from 500
to several thousand cells arranged at the periphery of a gelatinous
sphere of homogeneous mucilage, in which, however, the individual
cell sheaths may be distinct; the cells all directed outward and each
having 2 flagella of equal length. In some species, the cells are inter-
connected by protoplasmic strands or ‘canals’. Chloroplast a parietal
incomplete cup covering most of the cell wall. Daughter colonies
form within the interior of the sphere by repeated division of special
gonidial cells which have withdrawn from peripheral layer. Sexual
reproduction oogamous; female gametes large spherical cells within
the sphere; male gametes spindle-shaped, formed in several to many
rectangular plates or bundles in the interior of the colony, the
antherozoids with their longitudinal axes at right angles to the
surface plane of the plate. Zygote thick-walled, smooth, or bearing
external decorations such as spines and warts.
ecicea
Key to the Species
1. Colony of from 8000 to 17,000 cells which are angular,
polygonal. or stellate iiend view) == ee V. globator
1. Colony with fewer cells than above; cells round in end view_.-_____. 2,
2. Colony of 1800-3200 cells which are not inclosed by
TMNCUVAGl altars la eal thn gees ee ee La kL al ee V. aureus
bo
. Colony smaller, 500-2000 cells, inclosed by individual sheaths V. tertius
Volvox aureus Ehrenberg 1838, p. 71
Pl. 2, Fig. 4
Dioecious (rarely monoecious), spherical colonies of (500)-
1300-3200 ellipsoidal cells, 4-6. in diameter, with interconnections
of fine protoplasmic strands; individual cell sheaths wanting. Strands
of mucilage radiate from the center of the colony. Cells contain a
circular, parietal plate-like chloroplast, with 2 contractile vacuoles
at the anterior end, below the point of flagella attachment, and a
pigment-spot, anterior and lateral. In mature coenobia, 2 or more
daughter colonies are present. As many as 21 (usually about 9) eggs
are formed in female colonies; half of the cells in male coenobia
develop antherozoid bundles, 15-18, in diameter, with as many as
32 antherozoids in each bundle. Zygote 38-62, in diameter, with a
smooth wall.
Common in the plankton of many lakes; sometimes abundant in
shallow, backwater habitats; also found in inlets to lakes where
water is slow-flowing or pooled. Mich., Wis.
Volvox globator Linnaeus 1758, p. 820
Pl. 2, Fig. 5
Large, monoecious, spherical or ovate, gelatinous colonies contain-
ing as many as 17,000 ovoid or pyriform cells. Cells 2.5-3.5p in di-
ameter, with conspicuous protoplasmic interconnections; with 1
parietal plate-like chloroplast and a pigment-spot in each cell, and
with 2-6 small contractile vacuoles in the anterior region below the
point of flagella attachment. Individual sheaths of the cells conspic-
uous and not confluent with the colonial mucilage, clearly visible in
surface view of the colony, the sheaths 5-8-sided from mutual com-
pression. Coenobium commonly containing 4-7 (or as many as 17)
daughter colonies; sexual colony with 11-17, or up to 40, eggs, each
inclosed by a wide gelatinous sheath; 3-7 rectangular plates of fusi-
form antherozoids in bundles of 64-256, 22-32 in diameter. Zy-
gotes 45-54, in diameter, with thick walls exteriorly decorated with
wart-like, blunt spines and verrucae.
[ 78 ]
Although not uncommon in the plankton of lakes, this species is
most frequently found in the shallow water of bogs, ponds, and
ditches especially where the nitrogen content is high; also in hard
water habitats. Mich., Wis.
Volvox tertius A. Meyer 1896, p. 188
[Volvox mononae G. M. Smith]
Pl. 3, Fig. 12
Dioecious, relatively small colonies, 280-550. wide, 302-590.
long, spherical to ellipsoidal, containing 500-2000 ovoid or ellip-
soid cells without interconnecting protoplasmic strands, but with
individual sheaths which sometimes are scarcely evident. Cells 5-8,
in diameter. Chloroplast parietal, cup- or bell-shaped; pigment-
spot anterior and lateral; 2 (sometimes more) contractile vacuoles
below the point of flagella attachment. Mature coenobium contains
3-10-(12) daughter colonies. Eggs, 3-8 large globose cells inclosed
by a gelatinous sheath; antherozoid bundles 20-60 in number, con-
sisting of 16-32 (sometimes as many as 64) fusiform antherozoids;
zygotes 58-66, in diameter, with a thick, smooth wall.
This species is reported from Lake Monona, Wisconsin (Smith,
1920). In Iowa (Prescott, 193la) it was found in one of the semi-
hard water lakes, forming a dense bloom, which endured for two
or three days in late summer when the water temperature was
high (28°C.).
Mich., Wis.
FAMILY SPONDYLOMORACEAE
In this family the cells are compactly arranged in small colonies
of 8 or 16 individuals with their long axes parallel and all directed
forward. There is no colonial mucilage. The chloroplast is a dense,
parietal cup without a pyrenoid except in the genus Pascheriella
Korshikov (not represented in our flora).
There are 2 or 4 flagella, 2 contractile vacuoles in the anterior re-
gion, and a pigment-spot, either anterior or posterior. See Fritsch
(1934) and Smith (1938) for a discussion of reproduction in this
family; also Korshikov (1923, 1924, 1928).
SPONDYLOMORUM Ehrenberg 1849, p. 236
Colony ovoid, of 8 or 16 pyriform cells compactly arranged in
tiers without an evident gelatinous investment; the cells with their
broad apices all directed anteriorly, and having 4 long flagella which
[ 79 ]
arise from a conical protuberance, at the base of which are 2 con-
tractile vacuoles. Chloroplast cup-shaped, without a pyrenoid; pig-
ment-spot lateral and posterior.
Spondylomorum quaternarium Ehrenberg 1849, p. 236
Pl. 3, Figs. 1, 2
Cells narrowed and somewhat produced posteriorly to form blunt-
ly rounded points, 5-15, in diameter. Colony 36-75y in diameter.
Reported by Stickney from a laboratory aquarium in Madison; to
be expected in the plankton of lakes rich in nitrogenous substances.
Wis.
FAMILY HAEMATOCOCCACEAE
In this family the cells are peculiar in that the protoplast lies some
distance within the cell wall, to which it is connected by fine proto-
plasmic strands. Between the wall and the protoplast there is a wide
layer of mucilage. There is a massive chloroplast, which in Sphae-
rella is usually masked by an abundance of haematochrome, a red
pigment which develops when the cell is dormant. There are 2 fla-
gella, several contractile vacuoles, and a lateral pigment-spot.
Key to the Genera
Welispesp litany cece seus e, sony teem aie) cts A etn ence Haematococcus
Cells in colonies, forming a circumferential band in a
spheroidal gelatinous’ investment... .- = Stephanosphaera
Haematococcus C. A. Agardh 1828, Icon. Algar., Pl. 22.
Cells ovoid to ellipsoid, having 2 widely diverging flagella from an
anterior papilla; protoplast separated from the wall by a wide en-
velope of mucilage through which cytoplasmic strands radiate;
pigment-spot lateral. Cells frequently appearing in a stationary
(akinete) condition in which haematochrome pigment becomes pre-
dominant (assumed to be an adjustment to intense illumination,
especially when the water is shallow). At least 1 species of the genus
has been reported from red snow of alpine and subalpine regions.
Haematococcus lacustris (Girod.) Rostafinski, 1875, p. 139
Sphaerella lacustris (Girod.) Wittr.
Pl 2 Fig. 2: Pl. 3, Figs. 3-5
Cells ellipsoid or ovoid; chloroplast apparently cup-shaped, some-
times appearing axial and usually masked by haematochrome; cells
variable in diameter, 10-50 in the encysted condition.
[ 80 |
This species is usually found in small pools, crevices in rocks hold-
ing rain water, and in concrete basins of various kinds. A familiar
habitat is the bird-bath in gardens. Because intermittent drying of
the habitat keeps this plant in a dormant condition most of the time,
it usually appears as a brick-red, slimy or granular encrustment on
the substrate.
Mich., Wis.
STEPHANOSPHAERA Cohn 1852, p. 77
A colony of 4-8 ovoid cells with branched (both lateral and polar)
protoplasmic extensions, arranged in a median circumferential band
within an oblate-spheroid colonial mucilage. Cells free from, and
some distance from, one another, not connected by protoplasmic
extensions. Flagella 2; pigment-spot lateral, near the anterior end of
cell; chloroplast parietal and usually dense, with 2 or more pyre-
noids.
Stephanosphaera pluvialis Cohn 1852, p. 77
Pl. 46, Fig. 26
Characteristics as described for the genus. Cells 7-12.5, in diam-
eter; colony up to 60, in diameter. Reproduction by isogametes.
Zygote up to 28u in diameter.
Michigan.
ORDER TETRASPORALES!
Plants belonging to this order are essentially volvocaceous, but
they are nonmotile in the vegetative condition. Some forms are free-
floating, but many are sedentary. The volvocaceous characters are
pseudocilia (non-functioning flagella), the pigment-spot, and the
type of chloroplast. All of the features may not be exhibited by all
members. Most forms are colonial, with the cells embedded in
copious mucilage, but there are unicellular genera. It is easy to
confuse some of the small free-floating colonies with certain plants
belonging to the Chlorococcales. Differentiation must be made by
considering a combination of characteristics and the type of repro-
duction used. The Tetrasporales are able to reproduce freely by cell
division in the vegetative state, but the Chlorococcales are all in-
capable of this method of reproduction. In general, the chloroplast
in the Tetrasporales (Asterococcus excepted ), is a parietal cup (see
Elakatothrix, however), with a single pyrenoid. In the Chlorococ-
cales it is nearly always a parietal plate or sheet, not a Chlamydo-
monas-like cup.
1Some authors, Fritsch (1935), Pascher (1927), for example, treat the Tetrasporales as
a suborder of the Volvocales.
[ 81 ]
Key to the F amilies
1. Cells solitary or in false dendroid colonies, attached by stalks or fine
thread-like stipes to larger algae and microfauna_________ CHLORANGIACEAE
1. Cells not as above; free-floating or adherent_—_______-______ 2
2. Cells ellipsoidal or fusiform_ COCCOMYXACEAE
2. Cells spherical —_------—-—------ 3
3. Cells bearing pseudocilia (frequently discerned only with difficulty );
usually united in definitely shaped gelatinous colonies, macroscopic
or microscopic; individual cell sheaths rarely present and if present
may be scarcely visible__----—----—----—--------------------- TETRASPORACEAE
3. Cells not bearing pseudocilia; solitary or united in amorphous gela-
tinous masses; individual cell sheaths usually clearly visible _PALMELLACEAE
FAMILY PALMELLACEAE
These plants have spherical or ovate cells united in amorphous or
sometimes definitely shaped colonies. Individual cell sheaths (if
present) are clearly evident and are usually lamellate. Although
some colonies are spherical and free-floating, others are tubular or
bullate and adherent, or entangled among other algae. In one genus
( Asterococcus ) the chloroplast is stellate, but in general it is parietal
and cup-shaped. In 2 genera the sheaths are much lamellated and
are deposited as mucilaginous secretions about the cell more on one
side than on others so that the cell comes to lie excentrically in the
investment. Sometimes this may result in the formation of branched,
gelatinous strands.
Key to the Genera
Iea@ells solitary ae 2
1. Cells arranged to form colonies or families which may be definite or
indefinite in shape 8
2. Cells with a stellate chloroplast or with radiating strands from a
GOI OME CEIMLCT ese 2 ae alr a ee ee Asterococcus (in part)
2. Cells with a cup-shaped, parietal chloroplast____________-- Gloeocystis (in part)
(see also Urococcus )
3. Cells grouped to form amorphous colonies 4
3. Cells grouped to form colonies of definite shape, spherical
clusters, or tubular arrangements _______----------——-------——--—--—-----~-—=== 5
4. Colonies of macroscopic size, amorphous masses, adherent; cells single
or in pairs within a copious mucilage; cell sheaths confluent... Palmella
4. Colonies of microscopic size; cell sheaths definite, usually
lamellate-=1 i) Lied 8 ee Gloeocystis (in part)
5. Colonies -spherical________-____-_____-___>__ 6
5. Colonies elongate and tubular, forming false filaments. Palmodictyon
6. Chloroplasts stellate ____--------------------------------------- Asterococcus (in part )
6. Chloroplasts parietal a
7. Sheaths of cells definite, often lamellated; colonial mucilage
Vari ates fh ee aug ah eA Gia te aS Gloeocystis (in part)
7. Cells without sheaths, colonial mucilage homogeneous ___----- Sphaerocystis
[ 82]
PALMELLA Lyngbye 1819, p. 203
A shapeless, gelatinous mass, containing many spherical cells with-
out any order of arrangement; individual cell sheaths usually dis-
tinct at first, becoming confluent with the colonial mucilage. Chloro-
plast cup-shaped or bell-shaped, with 1 pyrenoid. Plants aquatic or
terrestrial.
Palmella mucosa Kuetzing 1848, p. 172
Pl. 3, Figs. 8, 9
Plant mass densely green, forming gelatinous expansions on the
substrate; individual cell sheaths evident at first but becoming in-
distinct; chloroplast parietal, covering nearly the entire wall; cells
6-14, in diameter.
On submerged logs, aquatic plants, and other substrates; frequent-
ly on wet rocks, on sides of aquaria, or on cement basins. Wis.
SPHAEROCYSTIS Chodat 1897, p. 119
A free-floating spherical colony of from 4 to 32 spherical cells,
evenly spaced near the periphery of a non-lamellate gelatinous en-
velope, sometimes with a sheath about each group of 4 cells within
the colony. Chloroplast cup-shaped and covering most of the wall,
containing | pyrenoid.
Sphaerocystis Schroeteri Chodat 1897, p. 119
Pl. 3, Figs. 6, 7
Colony often including both undivided and recently divided cells
which form small spherical clusters within the colonial envelope.
Cells 6-20, in diameter; colonies up to 500, in diameter.
This plant should be compared with Planktosphaeria gelatinosa.
Widely distributed and common in a variety of lakes, both hard
and soft water. Mich., Wis.
GLOEOCYSTIS Naegeli 1849, p. 65
Cells spherical, sometimes solitary, but usually grouped in colonies
of 4, 8, or many individuals inclosed by a colorless gelatinous en-
velope, which may be globose or somewhat amorphous, lamellate
or (rarely) homogeneous. Chloroplast parietal, cup-shaped, but
often covering the entire wall, obscured by numerous starch grains
or oil bodies; 1 pyrenoid. This genus should be compared with
Sphaerocystis and Planktosphaeria.
[ 83 ]
Key to the Species
1.Cells oblong ‘or ovate*<= 2 Se >a) See 2
1. Cells, spherical 2. eee 8
2. Colony triangular or pyramidal; individual cell sheaths distinct
and “much lamellated Ses ee G. planctonica
2. Golony.ovate oF aMmorphOuse == 225 ee ee 4
3. Colony spherical, usually of 8 cells (sometimes solitary), the
colonial mucilage and cell sheaths regularly lamellate______________. G. gigas
3. Colony amorphous, forming irregularly expanded, jelly-like masses,
often attached; colonial mucilage lamellate_.______________________ G. vesiculosa
4. Cells many in a colony; individual cell sheaths distinct, angular
frommutual compression, not lamellate=: == a es G. ampla
4. 1Cells) few inva colony; sheaths lamellate=— == = G. major
Gloeocystis ampla (Kuetz.) Lagerheim 1883, p. 63
Pl. 3, Fig. 17
Cells ovoid or oblong, arranged in amorphous or somewhat globu-
lar colonies and embedded in copious unlamellated gelatinous en-
velopes, the sheaths of each cell or group of cells not confluent but
distinct and angular from mutual compression. Cells 9-lly in
diameter, 10-14 long; colonies up to 150p in diameter.
Common in the tychoplankton of many soft water lakes and acid
swamps. Mich., Wis.
Gloeocystis gigas (Kuetz.) Lagerheim 1883, p. 63
Pl. 3, Fig. 16
One-celled or a colony of § spherical or slightly oblong individuals
inclosed by a copious, gelatinous, lamellate envelope. Contents of
the cell frequently brownish-green because of oil. Cells 9-12, in
diameter. Forming gelatinous masses on submerged aquatics or
entangled among other algae.
Common in the tychoplankton of many lakes and swamps. Mich.,
Wis.
Gloeocystis major Gerneck ex Lemmermann 1915, p. 35
Pl. 52, Figs. 9, 10
Cells ovoid, in colonies of 4-8, inclosed by a wide, lamellate sheath
in which groups of individuals are surrounded by concentric layers;
Chloroplast massive, completely covering the wall; cells 17-19, in
diameter, 21-23, long.
Tychoplankter; in hard water lakes. Wis.
[ 84 ]
Gloeocystis planctonica (West & West) Lemmermann 1915, p. 34
Pl. 3, Figs. 10, 11
Cells spherical or ovoid, united in free-floating gelatinous colonies
which are angular or pyramidal. Sheaths of each cell or group of
cells distinct and lamellate. Cells 4-13, in diameter; colonies up to
125 wide.
Common in the littoral plankton of shallow lakes and ponds; inter-
mingled with other algae. Mich., Wis.
Gloeocystis vesiculosa Naegeli 1849, p. 66
Pied, Bigals
Cells spherical, arranged in large amorphous masses (usually at-
tached), inclosed by copious lamellate mucilage. Cells 4.5-12 in
diameter.
Commonly intermingled with other algae in bogs and shallow
lakes; on submerged aquatics. Mich., Wis.
PALMODICTYON Kuetzing 1845, p. 155
Thallus an anastomosing or irregularly branched gelatinous strand,
inclosing families of globose cells with individual mucilaginous
sheaths. Frequently several generations of cells are within a common
investment. Chloroplast a parietal plate covering most of the cell
wall, with 1 pyrenoid.
Key to the Species
Cells without evident individual sheaths ess P. varium
Cells with distinct individual sheaths. 2-9 P. viride
Palmodictyon varium (Naeg.) Lemmermann 1915, p. 37
Pixs Figs. 3,4
Thallus a simple or branched gelatinous strand, often many such
tubular strands radiating from a common center, containing spheri-
cal cells without evident sheaths in linear series or irregularly crowd-
ed. Cells 4-8 in diameter; thallus 20-50, wide.
Entangled among dense growths of algae on submerged aquatics
in soft water lakes. Mich., Wis.
Palmodictyon viride Kuetzing 1845, p. 155
Pl. 4, Figs. 5, 6
Thallus a branching and anastomosing gelatinous strand or cylin-
der in which families of globose cells are arranged in groups of 2-4
within a mucilaginous sheath. Cells arranged in 1 or 2 linear series,
[ 85 ]
with distinct, sometimes lamellate sheaths. Cells 5-10, in diameter;
thallus 15-17, wide.
Not common in shallow water of acid lakes; among other algae in
tychoplankton. Mich., Wis.
ASTEROCOCCUS Scherffel 1908, p. 762
Cells globose or subglobose, either solitary or in colonies of from
4 to 16, in colorless homogeneous envelopes of mucilage. Chloroplast
4 stellate mass with radiate arms from a central core, which contains
a pyrenoid.
The shape of the chloroplast assists in differentiating this genus
from similarly shaped and arranged species of Gloeocystis.
ts (Celliwallsispiny = = Pe ss FE LET 8 SCR ie 28 he A. spinosus
Te Gelll-walls: smooth 2-2 ee
2. Cells solitary or in colonies of 4, 836-43 in diameter... A. superbus
2. Cells in colonies of 8 or 16, 10-25. in diameter —...........____. A. limneticus
Asterococcus limneticus G. M. Smith 1918, p. 627
Pl Ay Bigs
Cells spherical, arranged at some distance from one another in
free-floating colonies of 4-16 within a colorless homogeneous invest-
ing mucilage. Chloroplast stellate with 4-16 lobes radiating from a
central core, the lobes becoming flattened against the cell wall. Cells
10-25-(35)» in diameter; colonies 50-125» in diameter.
Common, usually in soft water. Mich., Wis.
Asterococcus spinosus Prescott in Prescott,
Silva, & Wade 1949, pp. 85, 93
Pl. 46, Figs. 17, 18
Cells spherical, solitary, or 2 within a gelatinous sheath, the cell
wall thin and evenly beset with long, slender sharp spines. Chloro-
plast with numerous (more than in other species ) narrow, radiating
strands. Cells 12-16, in diameter.
In shallow water of an acid lake. Mich.
Asterococcus superbus (Cienk.) Scherffel 1908, p. 762
Pl. 4, Fig. 10
Cells spherical, solitary, or in families of 4-8 inclosed by a lamel-
late gelatinous envelope. Chloroplast a stellate mass with several
ridges or rays flattened against the cell wall. Cells 36-43, in diam-
eter; 8-celled colony 93, in diameter.
Euplankter; tychoplankter among dense growths of miscellaneous
algae in shallow, soft water lakes and ponds. Mich., Wis.
[ 86 ]
FAMILY TETRASPORACEAE
In this family colonies of spherical cells bearing long, fine hair-like
pseudocilia are embedded in copious mucilage. The pseudocilia are
extensions from the protoplast; because they are extremely fine, fav-
orable optical conditions or special staining may be required in order
to distinguish them. The cell contents are as described for the order,
the chloroplast being a parietal cup or plate covering most of the
cell wall.
The cells usually remain in groups of 4 after division of the parent
cell and in most forms are disposed at the periphery of the colonial
mucilage. The colony may be amorphous or somewhat definite in
shape.
Key to the Genera
1. Plant mass mucilaginous, amorphous or intestiniform, macroscopic.____ @
1, Plant mass' of definite shape, microscopic 3
2. Plant an amorphous, usually floating, mass of mucilage in which
fragments of old cell walls remain...» Schizochlamys
2. Plant an elongate, tubular, or intestiniform, gelatinous thallus,
with cells arranged at the periphery of the mucilage;
fragments of old cell walls lacking — Tetraspora (in part)
5. An attached pyriform gelatinous thallus... Apiocystis
3. A free-floating, globular thallus of few cells,
embedded in homogeneous gelatin Tetraspora (in part)
TETRASPORA Link 1809, p. 9
Thallus a gelatinous sac, or a tubular or membranous mass, con-
taining spherical cells arranged in 2’s and 4’s. Chloroplast parietal,
bell-shaped, covering almost the entire wall, with 1 pyrenoid. Cells
often showing long, extremely fine pseudocilia which extend far
beyond the limits of the colonial mucilage; thallus attached, at least
when young, forming bulbous or vermiform masses, later becoming
free-floating green skeins or sheets; rarely globular and euplanktonic.
Some species of Tetraspora occur in early spring and are among
the first plants to develop in ditches and streams of cold water after
the melting of ice. They may continue on in favorable habitats
throughout early summer. Draparnaldia spp. are commonly found
associated with Tetraspora.
Key to the Species
1. Thallus cylindrical at all ages, attached; narrowed and
coustricted’ below to fommia short stipe 2. 6 2 T. cylindrica
1. Thallus not cylindrical at all ages, becoming bullate or expanded _____ 2
2. Cells with individual, thick gelatinous sheaths... T. lamellosa
2. Cells without individual sheaths, or with sheaths thin and diffluent_____ 8
3. Thallus an attached gelatinous sac, becoming bullate and lobed _ T. gelatinosa
8. Thallus not an attached, bullate, or lobed sac... 4
[ 87 ]
4, Thallus euplanktonic (or incidentally tychoplanktonic) spherical or
elongate, composed of relatively few cells evenly distributed or
arranged in groups of 4 within the colonial mucilage === T. lacustris
4. Thallus not planktonic, although frequently becoming free-floating
in age; at first tubular and sac-like, later expanded and laciniate,
forming Ss keinse: 2s cain a mae ath) Se ae eee eee ne es T. lubrica
Tetraspora cylindrica (Wahl.) C. A. Agardh 1824, p. 188
Pl. 5, Figs. 1, 2
Thallus an attached, irregularly lobed cylinder of firm mucilage
which may be 1 meter long, narrowed at the point of anchorage.
Cells scattered, showing arrangement in 4’s only when young,
14-17, in diameter.
Forming long, green, intestiniform strands in streams of cold
water. Mich., Wis.
Tetraspora gelatinosa (Vauch.) Desvaux 1818, p. 18
Pl. 5, Figs. 3, 4
Thallus at first an attached cylindrical sac, later becoming bullate
and lobed but not perforate. Cells irregularly arranged in old plants
and differing in size, 2.5-13, in diameter.
The globular and bullate form of the thallus, even when old, is
the chief differentiating character of this species. It is impossible to
separate this species clearly from young plants of T. lubrica.
In the quiet backwaters of lakes, among rushes. Mich., Wis.
Tetraspora lacustris Lemmermann 1898d, p. 152
Plo, Fig. 1
Thallus a free-floating, spherical, or elongate and irregularly
shaped, microscopic gelatinous colony containing relatively few
spherical cells, the long pseudocilia usually clearly evident. Cells
arranged in groups of 2 or 4; 7-10, in diameter.
This species is microscopic and apparently free-floating at all
stages. It should be compared with Sphaerocystis Schroeteri, from
which it may be differentiated by applying some simple stain to
determine the presence of pseudocilia. See Smith (1933, p. 352).
Common in the plankton of several lakes and inlets. Wis.
Tetraspora lamellosa Prescott 1944, p. 348
PI. 5, Fig. 6
Thallus irregularly lobed and saccate, free-floating. Cells spherical,
in 2’s, with thick walls and gelatinous, lamellate sheaths which are
[ 88 ]
distinct and not confluent with the colonial mucilage. Pseudocilia
very fine and 20-30 times the diameter of the cell in length. Chloro-
last a dense parietal plate covering almost the entire wall. Cells
9-10.5p in diameter.
This species differs from others by the possession of distinct lamel-
late cell sheaths and the extraordinarily long pseudocilia.
Euplanktonic. Wis.
Tetraspora lubrica (Roth) C. A. Agardh 1824, p. 188
Pl. 5, Fig. 9
Thallus at first tubular or sac-like and attached, later becoming
laciniate, irregularly expanded and floating, or forming streaming
gelatinous strands or skeins when in flowing water. Cells in 4's or,
when old, irregularly scattered through the rather firm mucilage;
7-10. in diameter.
In ditches, in cold springs, and flowing water; and in the marginal
flora of lakes. Mich., Wis.
APIOCYSTIS Naegeli in Kuetzing 1849, p. 208
Thallus a pyriform or irregularly bulbous, gelatinous vesicle, at-
tached by a narrowed base to submerged aquatic plants and fila-
mentous algae. Cells spherical, 64 to hundreds, evenly scattered or
sometimes in pairs or in circular zonations within the colonial mu-
cilage. Cells bearing a pair of very long pseudocilia. Chloroplast
parietal, covering most of the wall; with 1 pyrenoid.
Underdeveloped stages of this plant can scarcely be differentiated
from young or small colonies of Tetraspora.
Apiocystis Brauniana Naegeli 1849, p. 67
Plo; Figs. 7,'6, 10
Thallus an attached, pear-shaped, gelatinous vesicle in which the
cells are arranged at the periphery in 2’s or 4's. Pseudocilia clearly
evident. Cells 6-8u in diameter.
Considerable variation in the shape of the vesicle occurs, young
colcaie.. being almost round, with a very short stipe, whereas old
thalli are oboviform or pyriform.
This plant is attached to filamentous algae and submerged aqua-
tics such as Utricularia. It is common in acid water habitats where
temperatures are fairly high and where there is a great deal of
organic material. Mich., Wis.
[ 89 }
SCHIZOCHLAMYS Braun in Kuetzing 1849, p. 891
Thallus an amorphous gelatinous mass, either soft or firm, con-
taining numerous spherical cells irregularly arranged; fragments of
cell walls of previous generations lying about clusters of 2-4 cells.
Chloroplast usually a single parietal cup, sometimes occurring as 2
parietal plates; in some plants more massive and completely filling
the cell; with 1 pyrenoid. Pseudocilia sometimes discernible. Cells
divide by a splitting of the mother cell wall into 2 or 4 fragments
(sometimes old cell walls appearing as single pieces only), which
persist within the colonial mucilage.
Key to the Species
Gelatinous investment firm; colony of definite shape;
Gld mother cell wall-iragments Vor 2) S. compacta
Gelatinous investment soft and amorphous;
wallifragments of old mother cell’ 2ton 4 = 2 ee S. gelatinosa
Schizochlamys compacta Prescott 1944, p. 348
Pl. 4, Figs. 12-14
Thallus microscopic, the mucilage firm and homogeneous and
bounded by a definite tegument. Cells globose, with a conspicuous
gelatinous cap-like concretion at one side. After division, 1 fragment
(rarely 2) of the mother cell wall remains, the mucilage cap per-
sisting on the old wall; daughter cells with apposed caps of muci-
lage. Cells 7.4-11 » in diameter.
This plant should be compared with S. delicatula West, which
forms but a single fragment of the mother cell wall upon division to
liberate daughter cells. S. compacta differs in the definiteness of the
shape of the colonial mucilage, in the larger size of the cells, and in
the mucilage cap on the cell wall, the presence of which seems to be
a constant character.
Rare; in a small pool within a Sphagnum bog. Wis.
Schizochlamys gelatinosa A. Braun in Kuetzing 1849, p. 891
Pl. 4, Fig. 15
Plant mass extensive, often macroscopic and free-floating; muci-
lage soft and amorphous. Cells spherical, 10-15p in diameter, divid-
ing by a splitting of the cell wall into 2 or 4 portions, these persisting
and partially inclosing the daughter cells in pairs or in 4’5. Cells
have 1 or 2 chloroplasts; pseudocilia often evident.
Generally distributed in several types of lakes, but usually in
shallow warm water. Mich., Wis.
[ 90 ]
FAMILY CHLORANGIACEAE
Plants in this family are globose, ellipsoid, or oblong, attached by
a stipe to other algae or to microfauna. They may be solitary or
colonial, arranged in such a way as to form false filaments (i.e.,
series ) that may be simple or arbuscular. The cells are attached, the
anterior end downward, by a stalk-like extension of the sheath, in
which the protoplasts are inclosed. There is 1 cup-shaped chloro-
plast or 2 elongate parietal bodies, sometimes with a pyrenoid.
Usually there is an anterior pigment-spot.
Key to the Genera
Cells globose or ovoid; epiphytic in the Ege
of colonial blue-green algae —....... Stylosphaeridium
Cells elongate-ellipsoid or oblong- shite
epizoic on micrOratna \=s) 0 Cee ee et Chlorangium
CHLORANGIUM Stein 1878, Pl. 19, Figs. 1-7
Cells ellipsoid or spindle-shaped, solitary or in arbuscular series,
attached, anterior end downward, by mucilaginous (simple or
branched) stalks. Chloroplasts 2 laminate parietal plates; without
pyrenoids (?). Cells with 2 contractile vacuoles and a red pigment-
spot at the anterior end. Reproduction by longitudinal cell division
to form 2 or 4 daughter cells, which escape by the bursting of the
mother cell membrane that elongates and forms branching stalks
which result in arbuscular colonies. Biflagellate swarmers produced
by resumption of motility of vegetative cells. Gametes have been
reported.
Chlorangium stentorinum (Ehrenb.) Stein 1878, Pl. 19, Figs. 1-7
Pl. 46, Figs. 1, 2
Characteristics as described for the genus. Cells 12-14y in diam-
eter, 23-43 » long.
Widely distributed in the region, on microfauna in several types
of lakes. This species is not so common as Colacium spp. which also
attach themselves to Cladocera and copepods. Mich., Wis.
STYLOSPHAERIDIUM Geitler & Gimesi in Geitler 1925, p. 608
Cells globose or ovoid, solitary, attached by a slender stipe in the
mucilage of Coelosphaerium and Anabaena, and probably to other
Cyanophyta. Chloroplast solitary, massive, covering the posterior
(outer) portion of the cell wall, and containing a single pyrenoid.
This genus should be compared with Peroniella, a member of the
[ 91 ]
Chrysophyta which lacks a pyrenoid and has a parietal, plate-like
chloroplast along the lateral walls. There are species in that genus
which are similar in shape and habit to Stylosphaeridium, but they
are usually much larger.
Stylosphaeridium stipitatum (Bachm. ) Geitler & Gimesi
in Geitler 1925, p. 608
Pl. 4, Figs. 7-9
Characteristics as described for the genus. Cells 5-8» in diameter,
8-10 long; stipe 20p long.
This species apparently is not widely distributed in lakes of our
region, but in the habitats where it does occur it is common. The
plants are gregarious, and the host colony is usually thickly beset
with the epiphytes. Mich., Wis.
FAMILY COCCOMYXACEAE
Plants in this family are ovate, ellipsoidal, cylindrical or fusiform
cells, either solitary or forming colonies inclosed by a copious muci-
laginous investment. There is a single parietal chloroplast which
may have a pyrenoid.
The genera of the Coccomyxaceae are not altogether typical of
the Tetrasporales but are precluded from possible classification with
the Chlorococcales by the fact that the cells can undergo cell division
in the vegetative state.
Key to the Genera?
Cells fusiform or elongate-cylindric, arranged in a copious
mucilage to form spindle-shaped colonies —___--------------- Elakatothrix
Cells ovate or oblong, arranged in a flat plate
withinea, rectangular gelatmous sheath 2 Dispora
DISPORA Printz 1914, p. 32
Cells ovate to oblong, sometimes nearly spherical; pairs or quar-
tets of cells irregularly arranged within a wide gelatinous sheath,
forming a flat, rectangular plate, the colony increasing in size by cell
division in 2 directions in the same plane; chloroplast a parietal cup,
without a pyrenoid (?).
Dispora has been placed by Printz in another family, the Pleuro-
coccaceae, together with Coccomyxa, Pseudotetraspora, and Elakato-
thrix. Fritsch (1935) suggests that a suitable place for Dispora
would be with the Palmellaceae.
2Since this key was written, Coccomyxa dispar Schmidle has been collected in a Michigan
lake. This consists of ellipsoidal cells embedded in amorhous mucilz ve.
[ 92 ]
Dispora crucigenioides Printz 1914, p. 32
Pl. 46, Figs. 5, 6
Characteristics as described for the genus; cells broadly ovate to
nearly spheroidal, 3-5y in diameter, 4—6y long; colonies 20-30, in
width.
Tychoplankter; in soft water, northern lakes. Mich.
ELAKATOTHRIX Wille 1898, p. 302
Gelatinous, fusiform or irregularly shaped colonies containing fusi-
form or ovate cells. Free-floating at least when mature. Cells with
either 1 or both poles acutely pointed. Chloroplast a parietal plate
containing 1 or 2 pyrenoids and covering almost all the wall along
one side. Division transverse, the daughter cells lying in pairs with
their longitudinal axes parallel with the axis of the colony.
Key to the Species
Cells small, narrow, spindle-shaped, 3—6y in diameter,
pole: pomted, the other rounded =. E. gelatinosa
Cells broadly fusiform, larger, up to 15 in diameter,
taperinestoa-point: at beth poles=.-- 1) 82 eS E. viridis
Elakatothrix gelatinosa Wille 1898, p. 802
Pl. 3, Figs. 18, 14
A free-floating colony of 4-16 fusiform cells with longitudinal axes
parallel, arranged end to end in pairs, broad at the adjoined poles,
tapering to a blunt point at the opposite pole. Cells 3-6, in diam-
eter, 15-25, long; colony 10-30» in diameter, up to 160, long.
Rare to common in various types of lakes; mostly euplanktonic.
Mich., Wis.
Elakatothrix viridis (Snow) Printz 1914, p. 31
Pl. 4, Figs. 1, 2
A broadly ellipsoid colony, attached at first but later becoming
free-floating. Cells ovate or fusiform and arranged in pairs; dividing
transversely, but daughter cells with longitudinal axes at oblique
angles to one another. Cells 6-15, in diameter, 35, long.
Rare. Mich., Wis.
ORDER ULOTRICHALES
As interpreted here, this order includes unbranched, simple fila-
ments of mostly uniseriate cells, multiseriate in one suborder. With
few exceptions, the cells are cylindrical and contain a single, band-
[ 93 ]
like chloroplast which shows significant similarity to that possessed
by the Volvocales and most Tetrasporales. Usually 1 or more pyre-
noids are present. In some forms there is a basal-distal differentia-
tion, with an attaching holdfast cell. Most species which are attached
when young, however, become free-floating. Isogametes and zoo-
spores are produced in unspecialized vegetative cells. There are two
suborders.
SUBORDER ULOTRICHINEAE
FAMILY ULOTRICHACEAE
Nearly all the members of this family have cylindrical, uniseriately
arranged cells, either adjoined or separated from one another. In a
few forms there is a gelatinous sheath. The chloroplast is a parietal
late or band which varies in the degree to which it encircles the
cell wall. In a few species a special holdfast cell develops at the
base of the filament, the only cell incapable of further division. Re-
production is by vegetative proliferation, by palmella stages, by
zoospores, and by isogametes.
Key to the Genera
1. Filaments tapering at one end, and ending in a stout blunt point __Uronema
1. Filaments not tapering, the same diameter throughout > 2
2. Filaments inclosed by a gelatinous sheath ____- Fan aR Sag Ses 2 es 3
2. Filaments not inclosed by a gelatinous sheath ________________________.. f
3. Cells cylindrical, adjoined at the end walls to form continuous filaments. 4
3. Cells oblong or spheroidal, sometimes not forming continuous threads 5
4. Chloroplast a parietal band, nearly encircling the cell- Ulothrix (in part)
4, Chloroplast a parietal fold or plate, not encircling the cell,
covering only a small portion of the wall _________ Geminella (in part)
5. Cells spheroidal, adjoined in some species with the wall composed of
2 helmet-shaped halves which adjoin
in the miGrePiOM = ee DS 2 ee re ar goa A Radiofilum
5. Cells of different shapes from those above; wall
motcomposediotstwovhalves = esse eee ee eee §
6. Cells cylindrical, frequently in linear pairs, forming filaments
ofsndefinite: lenothylc:. 2.2 2bis e300. es Geminella (in part)
6. Cells transversely elliptic, in discontinuous series, often in groups of 4,
each group inclosed by a sheath; filaments short —._________. Hormidiopsis
7. Filaments with cells in pairs, the protoplasts at some
distance from the wall, the intervening space filled with
lamellate (¢elatmous| deposits Binuclearia
7. Filaments with cells not in pairs and without gelatinous
Gepasits aboubthe protoplasts eee a eee ee 8
8. Filaments of indefinite length, composed of many cells,
SOMMELIMEST With basallcitterem tl ctic imams meee eae nee enna nn enn n nS uOnESE EEE 9
[ 94 ]
8. Filaments of definite length, short and frequently interrupted;
basalyditierentiation lacking - Sess ee ees Stichococcus (in part)
9. Filaments often showing basal differentiation; chloroplast a complete
or-nearlycomplete parietal band = se Ulothrix (in part)
9. Filaments without basal differentiation; chloroplast a folded plate
along one side of the cell and not nearly encircling it 10
10. Chloroplast as long as the cell or nearly so
(See Ulothrix cylindricum, however)... Stichococcus (in part)
10. Chloroplast half the length of the cell = Hormidium
ULOTHRIX Kuetzing 1833, p. 517
Simple, unbranched filaments of cylindrical cells, often showing
basal differentiation and arising from a special holdfast cell; becom-
ing free-floating in some species. Chloroplast a parietal band which
extends %% to 34 of the way around the cell (forming a complete ring
in 1 species), and sometimes extending the entire length of the cell.
Asexual reproduction by 4-8 quadriflagellate zoospores cut out from
the protoplast of unspecialized cells; sexual reproduction by iso-
gametes formed 8-16-64 in a cell, smaller than the zoospores and
biflagellate. Palmella stages not uncommon.
This genus is distinguished from others in the family principally
by the approximate completeness with which the chloroplast covers
the wall, and also by the attached habit of growth, which involves a
basal holdfast cell in some species.
Key to the Species
1. Filaments (20)—25-45—(60) in diameter; wall thick;
chloroplast a ‘complete parietal band. U. zonata
1: “Filaments 20 or less in diameter; ‘wall thin: 2-2. 9
2. Filaments 11—20u in diameter CUE never Ree Rai Ae Wake eee ene 3
2°) alaments ‘smaller. 5—1 Uz in) diameters. eee x
3. Filaments composed of long, cylindrical cells, 11-12.5,» in
diameter, the length 2'4-3 times the width _______________. U. cylindricum
3. Filaments composed of shorter cells, 13-20u in diameter _- 4
4. Cells up to 20u in diameter, shorter than wide U. tenuissima
4. Cells 13-16y in diameter, 1-2 times longer than wide —.... U. aequalis
5. Cells 4—5u in diameter; chloroplast extending nearly the entire
lemme orsthie cell ¢2utes cee pee eee le The ho WO U. subtilissima
5. Cells wider; chloroplast extending 33 or less the length of the cell 6
6. Cells 5-6u in diameter, short-cylindric; chloroplast covering
aor less .Olgthe;cellawall ss ee 2 ae ee U. variabilis
6. Cells larger, 6-94 in diameter _...... _. gk SP RR oe Nee ier DB ah 2c w
7. Filaments constricted at the cross walls, 5.7—9u in diameter;
cells 2—4 times. ~diams long) Shs Oo hee oessccccctesesesee U. subconstricta
7. Filaments not or slightly constricted at the cross walls; cells
rectangular, 7.5—10y in diameter, the length 2/3 to 11/3
(HOG: AGG (a oats arc bnes tr ki ica A een he eee ed OLS ten U. tenerrima
Ulothrix aequalis Kuetzing 1845, p. 197
Pl. 6, Fig. 1
Filaments very long, composed of cylindrical cells and without
constrictions at the cross walls. Chloroplasts a parietal plate extend-
ing 4 of the distance around the wall. Cells 13-15.54 in diameter,
18-30 long.
Common; forming pure, bright green masses in shallow water of
several lakes and swamps; scattered among other algae. Mich., Wis.
Ulothrix cylindricum Prescott 1944, p. 349
Pl. 6, Fig. 2
Filaments long, curved, and lightly entangled. Cells elongate-
cylindric, 11-12.5. in diameter, 214 to 3 times longer than wide; the
wall thin and not constricted at the joints. Chloroplast a broad band,
nearly equal to the cell in length and folded around % of the cir-
cumference; pyrenoids 2-5.
This species should be compared with Ulothrix aequalis Kuetzing,
which has thick walls, shorter cells, fewer pyrenoids, and a different
form of chloroplast.
Tychoplankter. Wis.
Ulothrix subconstricta G. S. West 1915, p. 82
Pl6; Figs 1
Filaments planktonic, composed of slightly inflated cells, which
are moderately constricted at the cross walls and sometimes inclosed
in a gelatinous sheath. Chloroplast a parietal plate extending
through about 3 of the median region of the cell, sometimes with a
pyrenoid. Cells 5.7-9 in diameter, 10-36, long.
Euplankter. Wis.
Ulothrix subtilissima Rabenhorst 1868, Alg. Exsic. No. 655
Pl. 6, Fig. 3°
Filaments long and slender, free-floating or attached. Cells very
slightly inflated and constricted at the cross walls. Chloroplast ex-
tending the entire length of the cell, with 1 pyrenoid. Cells 4-5, in
diameter, 11-14.8, long.
In shallow water of a swamp. Wis.
Ulothrix tenerrima Kuetzing 1843, p. 253
Pl. 6, Fig. 12
Filaments free-floating or attached; long, or in short sections; com-
posed of cylindrical, relatively short cells with constrictions at the
[ 96 ]
cross walls. Chloroplast an irregularly folded plate, about 1%4 the
length of the cell, with 1 pyrenoid. Cells 7.5-10» in diameter, 10-15.
long.
Common in many lakes and ponds, both the eutrophic and the
soft water types. Mich., Wis.
Ulothrix tenuissima Kuetzing 1833, p. 518
P61, Wigs, 11912
Filaments long, composed of cylindrical cells that are shorter than
wide, 16-20 in diameter, thin-walled and not constricted at the
cross walls. Chloroplast a broad band encircling about 24 of the
circumference of the cell, with 2 or several pyrenoids.
Mich.
Ulothrix variabilis Kuetzing 1849, p. 346
Pl. 6, Fig. 18
Filaments long, slender, and entangled, forming cottony masses.
Cells cylindrical, without constrictions at the cross walls. Chloro-
plast a folded, parietal plate, 14 to 24 the length of the cell, with 1
pyrenoid (or 2 ?). Cells 4.5-6 in diameter and up to 15, long.
Common in a variety of lakes and in seeps along sandy shores;
often forming bright green, slimy masses in trickles from springs.
Mich., Wis.
Ulothrix zonata (Weber & Mohr) Kuetzing 1833, p. 517
Pl. 6, Fig. 14
Filaments attached, usually long and stout, variable in diameter
in the same plant mass. Cells short , or elongate-cylindric, sometimes
slightly swollen, with constrictions at the cross walls. Cell walls
thick, especially near the base of the filament. Chloroplast a com-
lete circular band in the midregion of the cell, with several pyre-
noids. Cells 20-45, in diameter, 21-60, long.
Not uncommon in several lakes in early summer; frequently
found in cold streams, artificial ponds, and in drinking troughs in
which there is running water, especially in spring. Mich., Wis.
HORMIDIUM Kuetzing 1843, p. 244; emend. Klebs 1896, p. 326
Simple filaments of cylindrical, undifferentiated cells. Chloroplast
a parietal plate extending around the cell for 14 or less of the cir-
cumference; 1 elongated or oval pyrenoid. Filament readily frag-
menting to form Stichococcus-like sections.
[ 97 ]
Hormidium Klebsii G. M. Smith 1933, p. 385
Pl. 6, Fig. 4
Long unbranched filaments in which there is no basal-distal dif-
ferentiation. Cells cylindrical, not constricted at the cross walls.
Chloroplast a parietal plate covering only a small portion of the cell
wall. Cells 5.8-6 in diameter, 15.6-25, long.
In Sphagnum bogs and roadside ditches. Wis.
URONEMA Lagerheim 1887, p. 517
Simple, unbranched filaments which are always attached. Cells
cylindrical, the basal cell forming an organ of attachment, the ter-
minal cell tapering unsymmetrically to a blunt boint. Chloroplast a
parietal plate, 14 to 24 the length of the cell; with 1 or 2 pyrenoids.
Uronema elongatum Hodgetts 1918, p. 160
Pl. 5, Fig. 5
Cells cylindrical, as much as 13 times their diameter in length,
and 5-10u wide. Chloroplast a parietal folded plate extending for
24 of the circumference and 14 to 24 the length of the cell; with 2
pyrenoids. Terminal cell unsymmetrically tapering to a blunt point
and often slightly curved.
This plant should be compared with germlings and young stages
in the development of Ulothrix and such members of the Chaeto-
phoraceae as Stigeoclonium and Chaetophora. The separation of
Uronema from Ulothrix has been questioned; but the tapering apical
cell persisting through maturity, the permanent attachment of the
plants, and the type of basal holdfast of Uronema seem to be suffhi-
cient justification for the retention of the two names.
Attached to filamentous algae and other submerged aquatics in
shallow backwaters. Mich., Wis.
STICHOCOCCUS Naegeli 1849, p. 77
Simple unbranched filaments of short, cylindrical, undifferentiated
cells, which are often loosely connected, so that interrupted series
are formed. Chloroplast a parietal folded plate, covering 1 or less
of the cell wall, with 1 pyrenoid. Filament fragmenting easily to
form short sections or solitary cells, which by vegetative division
rebuild longer, curved (sometimes coiled) or straight filaments. Fre-
quenting moist substrates in association with Protococcus [Pleuro-
coccus]; also in algal mixtures encrusting submerged wood, or on
aquatic plants.
[ 98 ]
Key to the Species
Da @ellse 24 te Water. * 2-0 * re weeds eee ements |e hi Se! PI en 2
lee Celisto—Gue wide tte 2k eee ee eee) | TL eStonibhilis
2: \Gells 2—3.on awide; 3-S4 long: se ee ek et S. bacillaris
27) Gellsio—4 wide’ and ‘upto SOn lompn = 2 TS, scopulinus
Stichococcus bacillaris Naegeli 1849, p. 77
Pl. 6, Fig. 5
Filaments composed of short cylindrical cells very slightly con-
stricted, if at all, at the cross walls. Chloroplast a pale green parietal
plate or folded disc covering a small portion of the wall. Cells
2-3.5u4 in diameter, 3-8, long.
On moist, aerial substrates, associated with other algae to form
films on floating wood, etc. Mich., Wis.
Stichococcus scopulinus Hazen 1902, p. 161
Pl. 6, Fig. 6
Filaments of relatively long cylindrical cells without constrictions
at the cross walls. Chloroplast a long, folded plate with an indistinct
pyrenoid. Cells 3-4 in diameter and up to 30, long.
Our specimens are questionably assigned to this species. Hazen
(I.c.) described the species as growing in dark green skeins on
dripping rocks. It has not been possible to differentiate it clearly
from S. bacillaris forma confervoidea Hazen (l.c., p. 60), except
that the cells in S. scopulinus average slightly wider.
On stones and moist soil, forming small green patches. Mich., Wis.
Stichococcus subtilis (Kuetz.) Klercker 1896, p. 103
Pl. 6, Figs. 7, 8
Filaments very long, composed of rather stout, cylindrical cells
without constrictions at the cross walls. Chloroplast an elliptical
parietal plate with 1 pyrenoid. Cells 5-7-(8), in diameter, 7-20,
long.
In shallow water of beach pools and lake margins. Mich., Wis.
GEMINELLA Turpin 1828, p. 329
Filaments unbranched and uniseriate, composed of spheroidal,
broadly ovoid, or short cylindrical cells inclosed by a wide gelat-
inous sheath and usually separated from each other; daughter cells
approximated for some time after division to give a paired arrange-
ment. Chloroplast a parietal folded plate, with 1 pyrenoid.
[ 99 ]
Key to the Species
1. Cells oblong or subquadrate; the lateral walls unsymmetrical
because of longitudinalifolds == = a G. crenulatocollis
1. Cells ovate, spheroidal, or oblong to subcylindrical; wall
without folds, the cells symmetrical. ss ee 2
2. Cells adjoined to form continuous filaments______________________ G. minor
2. Cells not adjoined, separated from one another
within a\gelatinous sheath... 2. 2h 2S ee 3
3. Cells in linear pairs, pairs separated from neighboring pairs
bya) cells length; cell 5—8,in*diameter> = See G. interrupta
85 (Gells\motiin pairs; evenly spaced! ina. linear Series22 8 4
4, Cells séparated from one another by a cell’s length or more G. ordinata
4, Cells separated from one another by less than a cell’s length G. mutabilis
Geminella crenulatocollis Prescott 1944, p. 349
Pl. 6, Figs. 9, 10
Uniseriate filaments of irregularly ovoid, subquadrate, or oblong
cells, with emarginate, crenulate, or wavy lateral walls; truncate or
broadly rounded at the poles, with folds and ridges sometimes pres-
ent in the lateral walls. Cells inclosed by a broad gelatinous sheath
and arranged in linear pairs, but often evenly spaced. Chloroplast
an irregularly shaped, folded parietal plate, which makes an almost
complete cylinder within the wall, often showing a ridge or wing-
like flange extending radially toward the wall. Cells 12-15p in
diameter, 18-24 iong.
This species should be compared with G. mutabilis, from which
it differs in the irregularly creased cell wall and the shape of the
chloroplast. Originally described from Wisconsin, this species has
since been found in Michigan.
In soft water and acid swamps; tychoplanktonic in mixtures of
algae in lake margins; in Sphagnum bogs. Mich., Wis.
Geminella interrupta (Turp.) Lagerheim 1883, p. 68
Pl. 6, Fig. 15
Uniseriate filaments of broadly ovoid or subcylindric cells; pairs o1
cells separated from the next pair in the series by at least a cell’s
length. Cells 5-84 in diameter, 6-15, long. Chloroplast a parietal
plate covering %% of the cell wall.
This species, even more than others in the genus, seems to be
confined to soft water lakes. It appears in great profusion in desmid
habitats. Mich., Wis.
Geminella minor (Naeg.) Heering 1914, p. 41
Pl 5 Mig. Ad,
Uniseriate filaments of short, cylindrical cells adjoined without
interruption within a wide gelatinous, homogeneous sheath. Chloro-
[ 100 ]
plast covering the entire lateral walls, but narrow, ring-like, and
zonate immediately following cell division. Cells 4-8 in diameter;
filament (including sheath) 8-18, in diameter.
This species often appears in the tychoplankton of acid lakes and
in small pools of Sphagnum bogs. Mich., Wis.
Geminella mutabilis (de Bréb.) Wille 1911, p. 72
Pl. 6, Fig. 16
Uniseriate filaments of broadly ovate, spheroidal, or cylindrical
cells, almost equally separated from one another, but with daughter
cells remaining in approximation. Chloroplast completely covering
the cell wall. Cells 9-13-( 20), in diameter.
Intermingled with other algae in shallow water of small lakes and
swamps. Wis.
Geminella ordinata (West & West) Heering 1914, p. 41
Pl. 24, F ig. 9
Uniseriate filaments of oblong-ellipsoid cells, arranged in an inter-
rupted series, separated from each other by a distance of a cell’s
length or more. Chloroplast solitary, extending completely around
the wall. Cells 5-5.8, in diameter.
Intermingled with other algae in shallow water of lakes and ponds.
Wis.
HORMIDIOPSIS Heering 1914, p. 50
Filaments short, composed of from 5 to 20 cells, arranged in con-
tinuous or interrupted linear series. Cells ovoid, cylindric, or trans-
versely ellipsoid, inclosed by a gelatinous sheath. Chloroplast a
parietal, incomplete band, without a pyrenoid (or with 1 ?). Oil
formed as a food reserve. Reproduction by zoospores or gametes
unknown.
Hormidiopsis ellipsoideum Prescott 1944, p. 350
Pl. 7, Figs. 1, 2
Cells transversely elliptic, arranged in linear series in groups of 4,
each group inclosed by a wide, hyaline, and homogeneous gelatinous
sheath. Chloroplast a parietal band as wide as the cell but not en-
tirely encircling the wall; with 1 pyrenoid. Cells 8» in diameter,
5.5p long; filament 14.8» wide.
Although this plant was found in only one collection it appeared
distinctive enough to be worthy of description. Hormidiopsis is a
little-understood genus, apparently containing but one other species,
H. crenulata Heering. To this genus, Heering has also assigned ques-
[ 101 ]
tionably a plant previously described by Borge as Ulothrix monili-
formis. Although our plant has the cell shape of the latter species
and is approximately the same size, it differs in the arrangement of
the cells. Ulothrix moniliformis Borge possesses cells in continuous
filamentous arrangement inclosed by a sheath. All of the Wisconsin
specimens had the cells arranged in crooked filaments in linear
groups of 4, each group with an individual sheath. Occasionally the
cells showed a tendency toward an irregular bilateral arrangement.
The chief objection to placing the Wisconsin species in Hormidiopsis
is the presence of a pyrenoid. The cell shape and arrangement would
seem to preclude the assignment of this species to Geminella. Addi-
tional observations and life history studies are necessary before the
plant can be satisfactorily identified.
Found in a Sphagnum bog lake intermingled with other algae.
Wis.
BINUCLEARIA Wittrock 1886, p. 9
Filaments of long cylindrical cells. Protoplasts short-cylindric or
oblong with rounded apices; not filling the cell, but surrounded by
lamellated mucilage, which fills the space between the protoplasts
and the end walls. Protoplasts in pairs (as a result of their remaining
close together after cell division) separated by a thin cross wall.
Chloroplast laminate, forming a band in the midregion of the cell;
without pyrenoid.
Binuclearia tatrana Wittrock 1886, p. 9
Pl. 7, Figs. 7-9
Cells 7-10, in diameter; the length sometimes as much as 6 times
the width.
Common in acid bogs and soft water lakes; appearing quite fre-
quently in small pools and ditches where the water is shallow and
where there is an abundance of organic matter. Mich., Wis.
RADIOFILUM Schmidle 1894, p. 47
Filaments either unbranched or branched, the branches sometimes
anastomosing to form a series of links. Cells lenticular, spherical, or
oblate-spheroidal, dividing in 1 or 2 planes. The cell wall (at least in
some species) composed of 2 cups or helmet-shaped halves, which
adjoin in the midregion to form a transverse rim around the cell, at
which point cell division occurs, new cell halves being interpolated
between the older parts of the cell wall. Chloroplast a parietal plate,
[ 102 ]
_ —OrrtC rh
with 1 pyrenoid, lying along the transverse wall. Filament inclosed
by a broad gelatinous sheath through which fibrillar concretions
radiate to the periphery.
Key to the Species
1. Cells transversely ellipsoid or subquadrate, arranged to form
a long continuous filament, inclosed in a relatively narrow
sheath; cell wall halves not apparent —_____________-_--________. R., flavescens
1. Cells a different shape from above, not forming
a continuous simple filament —- sete heh tS 5 5 eee. Say cena Ohl CS ee 2
2. Cells transversely lenticular, pointed at the poles, separated from
each other in a wide, gelatinous sheath, sometimes irregularly
arranged, forming filaments with anastomosing branches;
cellswallehalves;mot apparent 2. 25s ee R. irregulare
2. Cells spheroidal, evenly spaced and separate from each other;
cell wall halves evident, forming a transverse rim around
1d c=). (675) | | ee ae Ose ee 28 ae ee ene eee See ee ree Sete R. conjunctivum
Radiofilum conjunctivum Schmidle 1894, p. 48
[R. apiculatum West & West]
Pl. 7, Fig. 6
Filaments short, fragmenting readily, composed of spheroidal cells
in a wide gelatinous sheath. Cell walls formed by 2 cup-shaped
halves adjoined in the midregion and forming a rim which produces
an apiculation at each side of the cell. Chloroplast a parietal plate
lying along the end wall. Cells 6» in diameter, 4—6y long.
Very common in a large number of lakes and swamps, especially
in soft water and acid habitats, hence often associated with desmids.
Mich., Wis.
Radiofilum flavescens G. S. West 1899, p. 57
Pl. 7, Fig. 10
Filaments long, composed of transversely ellipsoidal or subquad-
rate cells in a narrow gelatinous sheath in which radiating fibrils
are apparent. Chloroplast a parietal plate. Cells 6.8-15, in diam-
eter, 5-10, long; filament 9-25, wide, including sheath.
Some specimens in our collections are larger than the dimensions
usually reported for R. flavescens, and have cells that are often def-
initely subquadrate. It is possible that such an expression justifies a
separation to form a new species. The shape of the cell in this species
is known to vary, however.
Scarce; in a few soft water lakes and in Sphagnum bogs. Mich.,
Wis.
[ 103 ]
Radiofilum irregulare (Wille) Brunnthaler 1918, p. 7
Pl. 7, Figs. 3-5
Filaments long, irregularly branched, branches often anastomosing
to form a series of chain-like links. Cells transversely ellipsoid, divid-
ing in 2 planes and appearing in more than | series within the wide
gelatinous sheath. Cell wall in 2 saucer-shaped halves, adjoined in
the midregion, the line of juncture not always evident. Cells 7-10
in diameter, 3.5-5, long.
Very common in desmid habitats and soft water lakes. Mich., Wis.
Published descriptions of this species do not mention the two-part
structure of the cell wall, a character of R. conjunctivum. Also the
shape of the cells in our specimens agrees closely with a plant which
W. and G. S. West originally described as R. apiculatum. The ar-
rangement of the cells and other features, the irregular form of the
filament in particular, justify referring our specimens to R. irregulare.
Radiofilum apiculatum West & West has been reduced to synonymy
with R. conjunctivum. The characteristics of our specimens would
apparently justify emending the description of R. irregulare if it
were determined that the type specimens possess the wall structure
of R. conjunctivum.
SUBORDER SCHIZOMERIDINEAE
FAMILY SCHIZOMERIDACEAE
In this family, which consists of the single genus Schizomeris, the
unbranched filamentous habit takes on a multiseriate expression.
The plant is uniseriate in the basal portion, where the cells are long
and cylindrical, but becomes multiseriate through cell division in 3
planes in the distal region, where the cells are brick-like and quad-
rangular. The cross walls of the lower cells are thick plates. Chloro-
plasts are broad parietal bands which encircle about %4 of the cell
wall in the lower cylindrical cells, but become massive and com-
pletely fill the cells in the distal portion of the filament.
The multiseriate habit and the method of zoospore escape (men-
tioned below) are characters which have influenced some phycol-
ogists to treat Schizomeris as a member of the Ulvaceae. It is an
enigmatic plant, and its inclusion with either the Ulotrichales or the
Ulvales seems justifiable.
SCHIZOMERIS Kuetzing 1848, p. 247
Characters as described for the family. Filaments uniseriate below,
with cylindrical cells; multiseriate above, with brick-like cells.
Chloroplast a parietal plate nearly encircling the lower cells, with
[ 104 }
several pyrenoids; distal cells have a dense chloroplast of indefinite
shape.
See Smith (1933, p. 457) for a discussion of the various opinions
concerning the taxonomic position of this genus.
Schizomeris Leibleinii Kuetzing 1848, p. 247
Pl. 7, Figs. 11-18
Filaments stout, macroscopic, 20-25 in diameter below, and as
much as 150, wide in the multiseriate upper portion of the frond.
Cells 15-30 in diameter. Zoospores formed in the upper limits and
escaping through an opening in the apex of the frond after interior
cell walls have disintegrated.
Rather rare; in shallow water and marsh-like margins of both hard
and soft water lakes; also in several swamps. Mich., Wis.
ORDER MICROSPORALES
In this order there is only one family, which is monogeneric. The
plants are unbranched filaments, which are free-floating except when
young. The most distinctive feature is found in the structure of the
cell wall. The cells are cylindrical, with walls composed of two
H-shaped sections which adjoin in the midregion. In the thin-walled
species, however, this feature is scarcely discernible. When the fila-
ment dissociates, the cells fall apart into H-shaped sections because
the cleavage occurs at the points of juncture in the midregion rather
than at the cross walls. The end of a filament shows a half of the
H adjoined to the terminating cell. A thin, internal cellulose mem-
brane holds the wall sections together. Another characteristic which
differentiates this order is the morphology of the chloroplast. Al-
though it shows different specific expressions, its general form is
that of a parietal reticulum or perforated sheet, which may be dense
and padded or open and thin, covering almost all of the cell wall.
Often the padded character gives the appearance of there being
several chloroplasts. Starch accumulates as a food reserve, but there
are no pyrenoids.
The absence of pyrenoids and the H-shaped wall sections are
characteristics in common with Tribonema in the Chrysophyta. In
that genus there are 2 to several disc-like, pale green chloroplasts,
and starch is not formed.
Asexual reproduction is by biflagellate zoospores; gametes are
unknown. Aplanospores are frequently formed, especially when
water temperatures become high.
[ 105 |
Microspora, the only genus, is sometimes included in the order
Ulotrichales. The characteristics of Microspora species are so dis-
tinctive, however, that placing them in a separate order seems
justifiable (Heering, 1914; et al.).
FAMILY MICROSPORACEAE
MICROSPORA Thuret 1850, p. 221
Plants unbranched, unattached filaments of uniseriately-arranged
cylindrical, or slightly swollen, cells (attached filaments are not un-
known, however). Cell walls thin in some species; in others thick
and lamellate, composed of 2 sections overlapping in the midregion.
Filaments fragmenting readily when mature by the separation of the
walls at their point of juncture, so that H-shaped sections and frag-
ments are formed. Chloroplast either a dense and irregularly padded
parietal plate or net, or an open meshwork or “rosenkranz’” form of
reticulum; pyrenoids lacking. Cells frequently forming aplanospores
or akinetes, the latter globose, with much-thickened walls.
Key to the Species
1. Walls thin, lu or léss in thickness; juncture of the wall
sections in the midregion of the cell not clearly evident
except upon fragmentation OPtheshlament ss) eee ee ee eee 2)
1. Walls 1.5-2.5u thick, often lamellate; juncture
of the wall sections clearly evident —_..__------------------------------------------------- 6
2. Chloroplast an open meshwork, stringy, but
sometimes thickened in places___——--------------------------=-------- 3
2. Chloroplast a parietal, perforated plate or close
meshwork covering most of the cell e171 | Me ce Nee lel sacle x SR lon wh J Dt erty 4
3. Cells distinctly cylindrical, 14-17» in diameter, 22-354 long .. M. floccosa
3. Cells quadrate or short-cylindric, 11—-14y in diameter
PTAs Hho} (0) 0272) 1) | (0) 04 eee reer ee reece peepee saa crc eaee een ncaace ccna: M. Willeana
4. Cells about 9u in diameter, 1-3 times the diameter
in length; chloroplast a granular plate M. stagnorum
4. Cells narrower, and usually shorter; chloroplast dense —________-- 5
5. Cells 6.7-9.5u in diameter, quadrate (sometimes as much
as twice the diameter in length); constricted at the cross walls _ M. tumidula
5. Cells 5.5-7.0u in diameter, shorter than wide, or quadrate;
MOM COUStEICLEC mata tine KCLOSS Hive |S eee ee ee M. quadrata
6. ‘Filaments 21.5—407: im diameter 224 ee sat
6. Filaments 20 or less in diameter ..--.....-.---------------------------------------2- 2 8
7, Filaments 21.5-27» in diameter, up to twice the diameter in
length; slightly constricted at the cross walls M. amoena
7. Filaments 26—-33y in diameter (rarely more ), cells usually
cylindrical, 1-14 times the diameter in length M. crassior
8. Cells cylindrical, 8-12 in diameter, up to twice the
diameter in length__._________-____--------------= M. pachyderma
8. Cells quadrate or cylindric, 13-20» in diameter: 325-2 ie ee 9
[ 106 ]
9. Cells elongate-cylindric, 13-15 in diameter, up to 3 times
FhegGiamictcrrmplonCth.-. -=>=S CHAETOPHORACEAE
FAMILY CHAETOPHORACEAE
In this family, as the name implies, most of the genera bear setae
or hairs. These may develop as outgrowths of the cell wall or they
may be formed by the attenuation of cells toward the apices of the
branches, forming short or long hyaline bristles, one or more cells
in length. The two chief expressions of these plants are the erect,
branched filament, and the prostrate, cushion-like expansion. In
some forms the thallus involves both a horizontal and an erect por-
tion. In prostrate species the thallus may be a single layer of cells
or it may be cushion-like and several cells in depth, especially in the
center, becoming 1-celled in thickness at the margin. In such plants
the true filamentous character may be lost because of the compact-
ness of the cells and the irregular habit of branching.
Key to the Genera
1. Plant a prostrate or creeping filament, little or not at all branched_____.. 2
1. Plant a much-branched filament; filaments
often adjoined and forming erect tufts, or
Pseudoparenchyniatous expansions =. 9-8 ss ee 3
2. Filament creeping, little or not at all
branched, if so, with branches not erect —___---__----------------------- Aphanochaete
2. Filaments creeping,.with infrequent, short branches ___________ Chaetonema
3. Plant consisting of an axial row of large, barrel-shaped or cylindrical
cells giving rise to nodal whorls of branches, or oppositely arranged
fascicles, of much smaller cells; thallus inclosed
faba SOLE COPIOUS MANCHA Ge 22 ee Draparnaldia
3. Plants without an axial row of distinctly larger cells; branch cells
about the.same size as those of the, main axis 2) Se 4
4, Plant a branched filament, the cells of the branches scarcely smaller
than those of the main axis, gradually tapering to long or short setae
or to pointed apical cells; horizontal or prostrate portion of the
thallus often present; thallus inclosed in a thin mucilage which
mipy snipe, be eViGent e252 ot ot ae es Stigeoclonium
PEEP TIE DIA LSA ADO VG eee wits NOL 50 ES EN hte pe ko ee
ee eelant anerece: branched “filament <2... 26 2 ee el 6
5. Plant a horizontal or pseudoparenchymatous expansion __________----------- 7
6. Plant a much-branched filament inclosed in firm, copious mucilage,
forming macroscopic thalli of definite
Shapes branches attenuate. 8225! aos the ee Chaetophora
6. Plant microscopic; branches not at all or scarcely
attenuate; investing mucilage wanting —_______________-_- Microthamnion
[ 113 ]
. Plant endophytic in the walls of large algae (sometimes epiphytic
also), consisting of an irregularly branched filament or pseudo-
parenchymatous mass of cells which bear no setae Entocladia
. Plant epiphytic or otherwise attached, not endophytic;
pseudoparenchymatous or discoid —. Brh esas
. Thallus a compact dise of definite limitation, with colorless hairs
arising from the outer sheath of the cells; filaments not evident _. Chaetopeltis
. Thallus a flat, broad, epiphytic disc with filaments
evident; cells without setae —-.________--. _. DUR! pacer ees Cee ae 9
. Thallus a broad, epiphytic disc, several cells in thickness, with
filaments radiating from a common center; margins of the frond
definite; evanescent hairs sometimes present__-_-.___________- Pseudulvella
. Thallus an irregularly spreading epiphyte; filaments adjoined and
compactly arranged, not radiating from a common center; one cell
infthickness;!setae lacking: 2 2ss Cee ee See eee Protoderma
STIGEOCLONIUM Kuetzing 1848, p. 253
A branched filament arising from a prostrate portion of a thallus,
which may be reduced to a pseudoparenchymatous mass of cells. In
some species the major portion of the plant spreads in loosely
branched, horizontal filaments; plant covered by a thin, scarcely evi-
dent, film of mucilage. Branches of first and second order either al-
ternate or opposite, and composed of cells scarcely smaller than
those of the main axis, ending in bluntly pointed or setiferous cells.
Chloroplast a parietal plate covering most of the cell wall, especially
in the cells of the branches; 1 to several pyrenoids. See Hazen (1902,
Pp:
fon) OD Ot Ol He i co
193) on the taxonomy of this genus in the United States.
Key to the Species
. Plants mostly prostrate and creeping; filaments
Wathia) few. Short vertical branches. ee ee S. polymorphum
. Plants mostly erect, branched filaments; horizontal
portion of the ‘thallus* reduced 223s et ee eee ee 2
» Branching mostly altemate!- 25-3 eee 3
/ Branching mostly opposite. = eee i
. Walls of main axial cells 1.5-2.5—(4)u thick; branching very irregular,
with long and tapering, as well as short, arbuscular or rhizoidal
branches produced throughout the length of the main axis__S. pachydermum
. Walls of main axial cells thinner; branching regular, the branches
gradually attenuated: toward the apices 20. i ee 4
. Plants short-tufted; apices of branches not tapering to
setae but 'short-pointed 2.2 eee een ie ee S. nanum
. Plants not short-tufted; branches elongate, gradually attenuate,
and: endmptnilong. setae. se ee 5
. Plants slender, main axis less than 8u in diameter... S. attenuatum
» Plants stouter) main aus 8—ISi) inidiameter 2. se eee eee 6
. Branches nearly always few-celled and thorn-like, 8—11y in
diameter,in, the amnain axis. eee S. stagnatile
. Branches elongate, thorn-like branches rare; cells 12-18, in
diameter sin’ thesmain, axis] ===. ee ee ee eee S. subsecundum
[114]
. Filaments slender and graceful, less than 10u in diameter S. tenue
pehilamentsestouter 91 4—l'Saminmciamectc rma mes ee alae u sre mene 8
. Main filaments 14-17 in diameter; branches mostly short-pointed;
cells of the main axis swollen, 1-2 times the diameter in length_.S. lubricum
. Main filaments (12)—14—18 in diameter; cells 4-8 times their
diameter in length, cylindrical; branches
attenuate candy SethLeK Otis!
15-(16)» in diameter, (21)—48-53-(66) long. Oogonia solitary;
globose; operculate; division superior; 40.7-42-(45), in diameter,
44-46-(49), long. Oospores globose; filling the oogonia; wall
smooth; 38-43, in diameter, 38-43, long. Antheridia 10.7 in
diameter, (5)-6-7-(8)» long.
In a roadside fosse. Wis.
Oedogonium crispum ( Hass.) Wittrock 1875, p. 10
Pl. 44, Fig. 5
Macrandrous; monoecious. Vegetative cells cylindric, (10)—12-l5pz
in diameter, 35-42-(80), long. Oogonia solitary; subglobose or
obovoid-globose; operculate; division superior; (37 )—39—-42-(45) »
in diameter, 42-50-(53) long. Oospores subglobose; the wall
smooth; 35-40-(43)» in diameter, 35-40-(43)» long. Antheridia
8-14, in diameter, 7-12, long.
In small pools on beach of lake, Wis., Mich.
Oedogonium crispum fa. inflatum Hirn 1900, p. 161
Vegetative cells 12-16, in diameter, 35-95, long. Oogonia obovoid-
globose, 40-50» in diameter, 45-53, long. Oospores 37—-45p in
diameter, 38-45» long. Antheridia 8-12, in diameter, 9-12 long.
Mich.
Oedogonium gracilimum Wittrock & Lundell in Wittrock 1875, p. 15
Pl. 34, Figs. 13, 14
Macrandrous; monoecious. Vegetative cells cylindric but often
irregular, forming crooked filaments, epiphytic on other species of
Oedogonium; (4)-5.2-5.5-(7)» in diameter, 15-22-(42) long.
Oogonia solitary; oblong; operculate; division superior; 14-19» in
diameter, 34-40» long. Oospores oblong-ellipsoid; not filling the
oogonia; 13-17, in diameter, 25-28-(82) long. Antheridia 3-5p in
diameter, 5-7,» long.
In a roadside fosse. Mich., Wis.
Oedogonium Gunnii Wittrock 1875, p. 387
Pl. 34, Figs. 15, 16
Macrandrous; monoecious. Vegetative cells cylindric or slightly
capitellate, 6-9.2-(10) in diameter, (16.6 )—20.3-30-(45) long.
Oogonia 1-4, depressed-globose; operculate; division median and
[ 190 ]
narrow (sometimes wide in our specimens); (23 )—25-26-(29), in
diameter, (19)-—29-30. long. Oospores depressed-globose; nearly
filling the oogonia; wall smooth; 22.5-27y in diameter, 17-18.5—( 23) p
long. Antheridia 7.6-9, in diameter, 3.8-11—(12) » long.
Attached to grass in a small pond. Wis.
Oedogonium inclusum Hirn 1895, p. 21
Macrandrous; monoecious. Described in previous section.
Oedogonium Itzigsohnii DeBary 1854, p. 56
Macrandrous; monoecious. Vegetative cells cylindric, 8-10 in
diameter, 25-50» long. Oogonia solitary; ellipsoid, with a median
whirl of cone-shaped projections; operculate; division inframedian;
34-40 in diameter, 32-40u long. Oospores globose; not filling the
oogonia; wall smooth; 20-23. in diameter. Antheridia 8-9, in
diameter, 8—15y long.
Mich.
Oedogonium minisporum Taft 1939, p. 80
Pl. 43, Fig. 1
Macrandrous; monoecious. Vegetative cells capitellate, 6-14, in
diameter, 53-69, long. Oogonia 1 or 2; subpyriform-globose to
subglobose; operculate, opening median; 30-42» in diameter, 34-42,
long. Oospores globose to subglobose; not filling the oogonia; wall
smooth (yellow); 25-30, in diameter, 24-29, long. Antheridia 8-11p
in diameter, 7-9» long.
Presque Isle County, Michigan.
Oedogonium minus ( Wittr.) Wittrock 1875, p.9
Pl. 34, Figs. 7-9
Macrandrous; monoecious. Vegetative cells capitellate; walls
spirally punctate; (9)-12-13, in diameter, (30)-35-74-(78)y long.
Oogonia solitary, globose or pyriform-globose; wall with spiral
punctations (in our specimens, with projections, as if mucilaginous
concretions had formed at the punctations); operculate; division
median; (34)-35-40-(46), in diameter, (28)-30-40-(42)» long.
Oospores depressed-globose; not filling the oogonia; wall smooth;
30-35-( 42). in diameter, (26)-30-33-(36) long. Antheridia 9-13,
in diameter, 3-5,» long (in series of up to 10).
In a roadside fosse. Mich.,Wis.
[ 191 ]
Oedogonium nodulosum Wittrock 1872, p. 22
Macrandrous; monoecious. Vegetative cells with 2 prominent
undulations and constrictions; 20-29. in diameter, 30-140, long.
Oogonia 1 or 2; obovoid-globose or obovoid-ellipsoid; operculate;
opening superior; 45-57» in diameter, 56-73, long. Oospores globose
or subglobose-ellipsoid; nearly filling the oogonia; wall smooth;
46-53, in diameter, 49-56y long.
Mich.
Oedogonium oblongum Wittrock 1872, p. 2
Macrandrous; monoecious. Vegetative cells cylindric, 6-lly in
diameter, 20-86 long. Oogonia solitary; oblong; operculate; division
superior; 20-264 in diameter, 41-60, long. Oospores ellipsoid to
ovate; not filling the oogonia; wall smooth; 19-23 in diameter,
30-36, long, Antheridia 6-9, in diameter, 7-9 long.
Mich.
Oedogonium oblongum var. majus Nordstedt in Wittrock 1876, p. 45
Vegetative cells 8-11, in diameter, 35-75 long. Oogonia 26—28y
in diameter, 42-50» long. Oospores 22-26 in diameter, 31-34» long.
Antheridia 4-9 in diameter, 9-10,» long.
Mich.
Oedogonium oblongum var. minus Wart 1939; p. 6!
Pl. 48, Figs. 2,3
Vegetative cells 3-6, in diameter, 16-35, long. Oogonia 13-16y
in diameter, 20-23 long. Oospores 11-15» in diameter, 17-21, long.
Antheridia 5-6 in diameter, 7p long.
Mich.
Oedogonium pachydermum Wittrock & Lundell
in Wittrock 1871, p. 125
Macrandrous; monoecious. Vegetative cells cylindric, 21-27» in
diameter, 34-120y long. Oogonia solitary (sometimes 2); ellipsoid;
operculate; division superior; 50-70p in diameter, 75-100, long.
Oospores ellipsoid; not filling the oogonia; wall smooth; 40-60 in
diameter, 50-80, long. Antheridia 18-21» in diameter, 10-12» long.
Mich.
Oedogonium poecilosporum Nordstedt & Hirn in Hirn 1900, p. 298
Macrandrous; monoecious or dioecious. Described in previous
section.
Oedogonium psaegmatosporum Nordstedt 1877, p. 24
Pl. 34, Fig. 4; Pl. 37, Fig. 6
Macrandrous; monoecious. Vegetative cells cylindric, elongate;
9-10-(14) in diameter, (56)-57—80, long. Oogonia 1-5, pyriform-
[ 192 }
globose; operculate; division median; (28)-33-39 in diameter
33-40--(43) long. Oospores depressed-globose; nearly filling the
oogonia; wall smooth; 27-3lp in diameter, 23-27 long. Antheridia
9-12, in diameter, 6-10-(11.7) long.
Our plants seem to belong here, although the vegetative cells
are slightly larger than described for this species and the oospores
sometimes do not completely fill the oogonia.
In a ditch through a Sphagnum bog. Wis.
Oedogonia pusillum Kirchner 1878, p. 59
PI. 37, Figs. 11, 12
Macrandrous; monoecious or dioecious. Vegetative cells cylindric,
6» in diameter, (10)-25-50-(60), long; basal cell hemispheric.
Oogonia solitary; subbiconic-ellipsoid to subbiconic-globose, with
a slight median constriction when mature; operculate; division
median; 14-16, in diameter, (15)-20-25 long. Oospores broadly
ellipsoid, but deeply constricted in the median portion; wall smooth;
11-13, in diameter, (13)-14-15-(16)» long. Antheridia 3-4 in
diameter, 5-6, long.
On aquatic vegetation in swamps and ditches. Mich., Wis.
Oedogonium pyriforme Wittrock 1875, p. 39
Pl. 34, Figs. 5,6
Macrandrous; monoecious. Vegetative cells cylindric, 13.6-15-
(16) in diameter, (48)-74-80-(90)y long. Oogonia solitary;
pyriform; operculate; division superior; 40-44.8—(46), in diameter,
(44 )—52.6-(60)» long. Oospores usually filling the oogonia and of
the same shape; wall smooth; (36)—40-42, in diameter, (36)-—40-44y
long.
On grass and Eleocharis in soft water lakes. Wis.
Oedogonium Reinschii Roy in Cooke 1883, p. 160
Pl. 34, Figs. 1-3
Macrandrous; monoecious. Vegetative cells subellipsoid to hexa-
gonal or fusiform, especially the latter shape in the lower portions
of the filament; (5)-7.5-8-(11)» in diameter, 8.5-19.2-(24), long.
Oogonia 1-2; pyriform-globose; operculate; division median; (17)-
19-20, in diameter, 15-21-(22.8)» long. Oospores depressed-globose;
not filling the oogonia longitudinally; wall smooth; (13)-15-18, in
diameter, 14—15-(17), long. Antheridia 4~9.5p in diameter, 9-11.4p
long.
This species was found to be in a reproductive state in several
places during August. It is one of the few species of the genus
[ 193 ]
which can be identified when in the vegetative condition, because
ot the distinctive cell shape.
Common in many desmid habitats where the water is soft or
acid. Mich., Wis.
Oedogonium spheroideum Prescott 1944, p. 353
Pl. 38, Figs. 3, 4
Macrandrous; monoecious. Vegetative cells elongate-cylindric,
16-19, in diameter, 115-155, long. Oogonia solitary; broadly ellip-
soid to subglobose; operculate; division superior; 55-64, in diameter,
80-87.5, long. Oospores spheroidal, the wall thick, outer membrane
with 12-15 longitudinal ribs; 57-60» in diameter, 57-60, long.
Antheridia 1-4, immediately below the oogonia or scattered. Anther-
ozoids 2; the division horizontal; 19-21, in diameter, 16, long.
This species should be compared with Oe. sol Hirn, which is
smaller and has an oospore with the middle, rather than the outer,
layer of the wall ribbed.
Attached to grass in a roadside swamp. Wis.
Oedogonium spirostriatum Tiffany 1936a, p. 2
Pl. 44, Figs. 1, 2
Macrandrous; monoecious. Vegetative cells slightly capitellate;
16-24-( 28), in diameter, 50-164, long; wall of the vegetative cells,
as well as of oogonia, with spirally disposed punctations; basal cell
hemispherical to nearly globose. Oogonia solitary; subglobose to
depressed-globose; operculate; division supramedian; 49-56 in
diameter, 40-50u long. Oospores depressed-globose, about the same
shape as the oogonia but not filling them; 40-47» in diameter,
34-40» long. Antheridia 20-24, in diameter, 17-20, long.
This species should be compared with Oe. punctatostriatum,
which is dioecious and has cylindric cells; also the oogonium of Oe.
punctatostriatum has a median, rather than a supramedian, division.
Common in many lakes. Mich., Wis.
Oedogonium spurium Hirn 1900, p. 301
Macrandrous; monoecious or dioecious. Described in previous
section.
Oedogonium trioicum Woronichin 1923, p. 99; 1923a, p. 141
Macrandrous; monoecious or dioecious. Described in previous
section.
[ 194 ]
SECTION 5
Nannandrous—Idioandrosporous—Poriferous
Oedogonium cyathigerum Wittrock 1871, p. 181
Nannandrous; idioandrosporous. Vegetative cells cylindric, 2130p
in diameter, 40-300» long. Oogonia 1-8; subovate; opening by a
superior pore; 57-65, in diameter, (70)-77-100p long. Oospores
subovoid or quandrangular-ellipsoid; outer spore wall smooth
middle layer with 16-25 longitudinal ribs; 51-62» in diameter,
60-75. long. Dwarf male plants 10-15, in diameter, 50-58, long.
In swamps. Mich., Wis.
Oedogonium cyathigerum fa. ornatum (Wittr.) Hirn 1900, p. 254
Pl. 44, Fig. 13
A form somewhat larger throughout than the typical plant and
with dwarf males more elongate.
With the typical plant. Wis.
Oedogonium gallicum Hirn 1900, p. 197
Pl. 39, Fig. 4
Nannandrous; idioandrosporous. Vegetative cells cylindric, 16-
18.5-( 22) in diameter, 51-65-(120) long. Oogonia solitary (rarely
2 together); globose; opening by a median or supramedian pore;
(39)—45-48, in diameter, 40—-45-(54), long. Oospores depressed-
globose; filling the oogonia; wall thick, smooth; 36-46, in diameter,
39-44, long. Dwarf male plants 2-celled, on the suffultory cells.
Antheridia exterior, 11.71 in diameter, 10-13, long. Suffultory cell
18, in diameter, 51, long.
In waterlily pond. Mich., Wis.
Oedogonium hystricinum Transeau & Tiffany 1919, p. 240
Nannandrous; idioandrosporous. Vegetative cells cylindric, 8-l5pz
in diameter, 42-100, long. Oogonia solitary; globose or obovoid;
opening by a median pore; 30-40» in diameter, 35-53 long.
Oospores globose or subglobose; outer wall densely spiny; 23-38,
in diameter, 28-43, long. Antheridia 5-6 in diameter, 6-10p long.
Mich.
Oedogonium idioandrosporum (Nordst. & Wittr.)
Tiffany 1934, p. 325
Nannandrous; idioandrosporous. Vegetative cells cylindric, 25-36,
in diameter, 65-200» long. Oogonia 1-8; globose-obovoid to globose;
[ 195 ]
opening by a superior pore; 48-59» in diameter, 57-90, long.
Oospores ellipsoid-globose, ovoid, or angular-globose; wall smooth;
42-57 in diameter, 50-66. long. Antheridia 8-10» in diameter,
10-18, long.
Mich.
Oedogonium irregulare Wittrock 1871, p. 128
Nannandrous; idioandrosporous (?). Vegetative cells cylindric,
15-20. in diameter, 40-8Uz long. Oogonia solitary; globose or
subdepressed-globose; opening by a superior pore; 37—45y in diam-
eter, 36-47 long. Oospores globose; filling the oogonium; wall
smooth; 36-42 in diameter, 34-41, long. Antheridia 10-12, in
diameter, 6-8» long.
Mich.
Oedogonium magnum (Ackley ) Tiffany 1934, p. 325
Nannandrous; idioandrosporous. Vegetative cells cylindric, 14-18p
in diameter, 30-90p long. Oogonia solitary; subglobose; opening by
a supramedian or median pore; 40-43, in diameter, 33-38, long.
Oospores globose to subglobose; wall smooth; 38-41» in diameter,
32-36, long. Antheridia 8-10-(12), in diameter, 8-10,» long.
Mich.
Oedogonium multisporum Wood 1869, p. 141
Nannandrous; idioandrosporous (or gynandrosporous ?). Vegeta-
tive cells cylindric, 10-15y in diameter, 10-30 long. Oogonia 1-3;
subovoid or subglobose; opening by a superior pore; 2435p in
diameter, 27-33, long. Oospores globose; nearly filling the oogonia;
wall smooth; 27-30, in diameter, 24-30y long. Antheridia quadrate,
7-9, in diameter.
Mich.
Oedogonium perfectum (Hirn) Tiffany 1934, p. 326
[Oe. cyathigerum fa. perfectum Hirn]
P3095 Migs: 6, 7,
Nannandrous; idioandrosporous. Vegetative cells cylindric, 20-
30-(35) in diameter, (65)-92-350, long. Oogonia solitary (or as
many as 4 in a series ); subovate, subquadrangular-ellipsoid, or ovate;
opening by a superior pore; (65)—66-72-(85), in diameter, 70-85-
(111), long. Oospores obovoid; filling the oogonia; outer spore wall
smooth, middle layer ridged with 16-24 anastomosing and curved
costae; 59-70-(80)» in diameter, (65)-—70-83-(85) long. Dwarf
male plants on the suffultory cells, 12-16 in diameter, 50-58—(85) »
long.
In swamps. Wis.
[ 196 ]
Oedogonium Westii Tiffany 1934, p. 325
Pl. 39, Fig. 8
Nannandrous; idioandrosporous (?). Vegetative cells cylindrical
or somewhat capitellate, (17)-19.5-29-(35), in diameter, (S1)-
117-163-(180), long. Oogonia solitary or as many as 3 in a series;
obovoid or ellipsoid; opening by a superior pore; 53-68, in diameter,
67-99, long. Oospores obovoid or ellipsoid; filling the oogonia;
wall smooth; (49)-54.6-65, in diameter, (49)-68.2-81 long. Dwart
male plants on suffultory cell. Antheridia 18, in diameter, 13, long.
On grass and other submerged aquatics in several soft water and
acid lakes. Wis.
SECTION 6
Nannandrous—Gynandrosporous—Poriferous
Oedogonium Braunii Kuetzing 1849, p. 366
Nannandrous; gynandrosporous. Vegetative cells cylindric, 13-15
in diameter, 25-60, long. Oogonia solitary; ovate or subglobose;
opening by a median pore; 30-37» in diameter, 33-43, long.
Oospores globose; wall smooth; 27-33, in diameter. Antheridia 5-8»
in diameter, 9-10, long.
Mich.
Oedogonium concatenatum Wittrock 1875, p. 25
Nannandrous; gynandrosporous. Vegetative cells cylindric, 25—40p
in diameter, 75-400» long. Oogonia 1-6, subovate or quadrangular-
ellipsoid; opening by a superior pore; 63-83, in diameter, 76-105.
long. Oospores subovoid or quadrangular-ellipsoid; median wall
with pits arranged in longitudinal series; 60-75, in diameter, 67-95p
long. Antheridia 13-15, in diameter, 12-25p long.
Mich.
Oedogonium crassiusculum Wittrock 1871, p. 182
Nannandrous; gynandrosporous. Vegetative cells cylindric, 27-30
in diameter, 95-105» long. Oogonia 1-2; globose-ovate or subglo-
bose; opening by a superior pore; 54-60» in diameter, 60-75, long.
Oospores ellipsoid-globose or globose; wall smooth, thick; 51-57u
in diameter, 52-63, long. Antheridia 7-9, in diameter, 9-16, long.
Mich.
Oedogonium depressum Prigsheim 1858, p. 69
Nannandrous; gynandrosporous. Vegetative cells cylindric, 5—9p
in diameter, 25-54 long. Oogonia solitary (sometimes 2); globose
or subglobose; opening by a median pore; 28 in diameter, 26 long.
Oospores depressed-globose, not filling the oogonia; wall smooth;
234 in diameter, 17-18, long. Dwarf male plants 4-5p in diameter,
14-16 long.
Mich.
[197 ]
Oedogonium hispidum Nordstedt in Wittrock 1871, p. 128
Pl. 24, Fig. 4
Nannandrous; gynandrosporous. Vegetative cells cylindric, 9-l4y
in diameter, 36-1380» long. Oogonia solitary; terminal; subellipsoid
or ellipsoid-globose; opening by an inferior pore; 35-44, in diameter,
42-56 long. Oospores globose to globose-ellipsoid; not filling the
oogonia; outer wall spiny; 32-39» in diameter, 32-40 long. An-
theridia 5-6, in diameter, 7-9p long.
Mich.
Oedogonium multisporum Wood 1869, p. 141
Nannandrous; gynandrosporous or idioandrosporous. Described in
previous section.
Oedogonium Sawyerii Prescott 1944, p. 354
Pl. 39, Fig. 1
Nannandrous; gynandrosporous. Vegetative cells cylindric, stout;
30-33.3n in diameter, 66.6-8l long. Oogonia solitary; nearly glo-
bose; 63-66.62 in diameter, 55-60 long; opening by a superior
pore. Suffultory cell swollen. Oospores globose; outer membrane
with a prominent spiral ridge, continuous from pole to pole, the
axis of the spore turned at an angle of about 30 degrees from the
longitudinal axis of the oogonium; 50-55p in diameter (including
ridge). Male plants on the suffultory cell. Antheridia 8-10, in
diameter; androsporangia 25.9» in diameter, 14.8» long.
This species should be compared with the smaller and idioandro-
sporous Oe. latviense (Tiff.) Tiffany and with Oe. spiripennatum
Jao, which has a median pore.
In a beach pool cut off from a soft water lake. Wis.
Oedogonium sexangulare Cleve in Wittrock 1871, p. 131
Pl. 39, Figs. 2,3
Nannandrous; gynandrosporous. Vegetative cells cylindric, (9)-
16-20-(22.6)» in diameter, (33)-39-57-(78) long. Oogonia soli-
tary; sexangular-ellipsoid; opening by a median pore; 29-33-(40)
in diameter, (33)-34-89, long. Oospores the same shape as the
oogonia and filling them; wall smooth; (27)-31p in diameter,
(31 )-86-38.7-(40)» long. Dwarf male plants on the suffultory cell.
Antheridia exterior, 6-8. in diameter, 9-12» long. Suffultory cell
somewhat larger than the vegetative cells.
In a lily pond and in acid swamps. Mich., Wis.
Oedogonium stellatum Wittrock 1871, p. 129
Nannandrous; gynandrosporous. Vegetative cells cylindric, 15-35,
in diameter, 40-225, long. Oogonia 1-3; obovoid-globose; opening
[ 198 ]
by a superior pore; 51-64, in diameter, 56-70% long. Oospores
globose; filling the oogonia; outer wall spirally striated with ribs;
50-58 in diameter. Antheridia 6-9, in diameter, 8-13, long.
Mich.
Oedogonium subsexangulare Tiffany 1934, p. 325
Pl. 39, Fig. 5
Nannandrous; gynandrosporous. Vegetative cells cylindric, (15)-
19-24 in diameter, (20)-30-(68), long. Oogonia solitary; sexan-
gular; opening by a median pore; 35-38-(48), in diameter, (41)-
45-50, long. Oospores the same shape as the oogonia and filling
them; 3440, in diameter, (39 )—40—-43-( 48) long; the wall smooth.
Dwarf male plants with elongated stipes. Antheridia 6—S» in
diameter, 8-10, long.
Floating clots of filaments in a small pond. Wis.
SECTION 7
Nannandrous—Idioandrosporous or Gynandrosporous—Poriferous
Oedogonium Borisianum (LeCl.) Wittrock 1875, p. 25
Pl. 35, Figs. 8,9
Nannandrous; gynandrosporous or idioandrosporous. Vegetative
cells cylindric, (15)-18.5-24» in diameter, (45)—-55-59—-(140)» long.
Oogonia 1-5; obovoid or angularly ellipsoid; opening by a superior
pore; (33)—40-50 in diameter, 55-90 long. Oospores obovoid;
filling the oogonia in diameter but not in length; wall thick, smooth;
(35)-47-49u in diameter, (48)-55.5-57-(60) long. Dwarf male
plants on the much enlarged suffultory cell. Antheridia exterior;
§-10u in diameter, (11)-12-15-(16), long. Suffultory cell 37, in
diameter, 55-(92)» long.
Common in several swamps and small lakes. Mich., Wis.
Oedogonium echinospermum A. Braun in Kuetzing 1849, p. 366
Pl. 35, Figs. 10, 11
Nannandrous; gynandrosporous or idioandrosporous. Vegetative
cells cylindric, 18-21-(30) in diameter, (45)-62-130, long. Oogonia
depressed-globose or ellipsoid-globose; opening by a median pore;
(39)-50-54.6y in diameter, (41)-46—49-(57) long. Oospores globose
or depressed-globose; the outer wall furnished with short, sharp
spines; (38)—46—47, in diameter, (38)—40-44-( 49)» long. Dwarf
male plants on the suffultory cell. Antheridia exterior, 6-9-(12), in
diameter, 6-11-(15) long.
On overhanging grass in a ditch through a Sphagnum bog. Mich..,
Wis.
[ 199 ]
Oedogonium spiralidens Jao 1934, p. 84
Pl. 40, Fig. 1
Nannandrous; gynandrosporous or idioandrosporous. Vegetative
cells cylindric, (12)-14-16-(18) in diameter, (50)-55-76—(85)»
long. Suffultory cell enlarged, 22.5 in diameter, 70.3» long. Oogonia
solitary; globose or obovoid; opening by a median pore; (42)—44—
46—(50) in diameter, (40 )—48—(50) » long. Oospores nearly globose,
with long axis transverse to long axis of oogonium; outer spore
wall with 4-7 spiral costae, irregularly toothed at the edges, the
costae meeting at the poles; wall also marked with coarse granula-
tions or crystalline deposits; 41-50, in diameter, 41-47 long. Dwarf
male plants 2- or 4-celled; on the suffultory cell; 10-12-(18), in
diameter, 62.91 long. Antheridia exterior; 6-7.8-(8)» in diameter,
(8)—-11-12y long.
Attached to reeds in lakes. Wis.
Oedogonium striatum Tiffany 1934, p. 326
Pl. 39; Fig. 10
Nannandrous; gynandrosporous or idioandrosporous. Vegetative
cells cylindric or slightly capitellate, (18)-30-36, in diameter,
(53 )-76-250 long. Oogonia 1-8-(10); subovate or ellipsoid;
opening by a superior pore; (67 )—76-80p in diameter, 79-83-(92) »
long. Oospores the same form as the oogonia; the outer layer of
the spore wall with about 40 longitudinal, anastomosing ribs;
64-72-(76)» in diameter, 74-76-(90) long. Dwarf male plants
on the much enlarged suffultory cell. Antheridia exterior; (12)-13.3-
14, in diameter, 9.5-12y long. Suffultory cell 57-68.4, in diameter,
117, long.
In a small northern lake among sand hills. Wis.
Oedogonium Wolleanum Wittrock 1878, p. 137
Pl. 35, Figs. 12, 18
Nannandrous; gynandrosporous or idioandrosporous. Vegetative
cells long, cylindric; (21)-25-30, in diameter, (65)-70-180-( 235)
long. Oogonia 1-4, ellipsoid or subquadrangular; opening by a
superior pore; 58-65-(68), in diameter, (65)-69-80-(89), long.
Oospores filling the oogonia and of the same shape; the outer layer
of the spore wall furnished with 25 or more ribs with entire margins;
(56 )-58-65-(66) in diameter, 65-80.5-(83), long. Dwarf male
plants, usually several, on the suffultory cell; 2- or 4-celled. Anther-
idia exterior; (9)—10-12-(14), in diameter, (7)—8-10-(11), long.
Suffultory cell much enlarged, (45)—48-53-(65) » in diameter.
In a small northern lake among sand hills. Wis.
[ 200 ]
SECTION 8
N annandrous—Idioandrosporous—Operculate
Oedogonium Ackleyae Tiffany 1937, p. 70
Nannandrous; idioandrosporous (?). Vegetative cells cylindric,
9-11» in diameter, 27-60 long. Oogonia 1-3; globose or subglobose;
operculate; division superior; 32-35, in diameter, 30-35, long.
Oospores globose; not filling the oogonia; median wall scrobicuiate;
31-33 in diameter, 31-32. long. Antheridia 8-9» in diameter,
6-10, long.
pach Oedogonium brasiliense Borge 1899, p. 4
Pl. 41, Figs. 3, 4
Nannandrous; idioandrosporous. Vegetative cells distinctly capi-
tellate, (16)-20.3-22, in diameter, (35 )-55-74—(95)» long. Oogonia
1-4-(9); depressed-globose; operculate; division wide, median or
supramedian; 51.8-55.5-(63) in diameter, 46.2-52-(59) long.
Oospores globose or depressed-globose; not filling the oogonia; wall
smooth; (44.5)—48-53, in diameter, 33-35-(45) long. Dwarf male
plants unicellular; on the oogonia; 11, in diameter, 12-13-(19) long.
Our specimens differ from the original description of Oe. brasilien-
se in having the operculum sometimes supramedian and in having
the oogonia in longer series.
In a small pond on grass. Wis.
Oedogonium Kozminskii Prescott 1944, p. 355
Pl. 42, Figs. 4-6
Nannandrous; idioandrosporous. Vegetative cells cylindric to
slightly capitellate, 14-15.6. in diameter, 50-60 long. Oogonia
solitary; globose; operculate; division supramedian; (46 )-50.7-52p.
in diameter, 46-53.7 long. Oospores globose or depressed-globose;
wall smooth; 43.9-45, in diameter, 39-42 long. Suffultory cell not
enlarged or scarcely so. Dwarf male plants unicellular; on the
oogonia; 11.7-13, in diameter, 13-14.5p long.
The distinguishing characteristics of this species are the capitellate
vegetative cells and the supramedian opening of the oogonium. It
should be compared with Oe. mirandrium Skuja, in which the
suffultory cell is enlarged and the oogonium smaller.
Attached to grass in a Sphagnum bog. Wis.
Oedogonium longatum Kuetzing 1853, Tab. Phyc. 3, p. 11
Nannandrous; idioandrosporous (?). Vegetative cells cylindric,
4-7, in diameter, 10-35y long. Oogonia 1-3; ovate or ellipsoid;
operculate; division superior; 16-18, in diameter, 21-25, long.
[ 201 ]
Oospores ellipsoid, nearly filling the oogonia; wall smooth; 15-17,
in diameter, 17-20, long. Antheridia 4-5 in diameter, 5-6y long.
Mich.
Oedogonium macrandrium Wittrock 1871, p. 130
Nannandrous; gynandrosporous; operculate. Described in the fol-
lowing section.
Oedogonium megaporum Wittrock 1872, p. 3
Nannandrous; idioandrosporous. Vegetative cells cylindric, 13-17p
in diameter, 40-100. long. Oogonia 1-6; pyriform, with 12-16
longitudinal ribs; operculate; division supramedian; 37-42, in
diameter, 40-45, long. Oospores subdepressed-globose; not filling
the oogonia; wall smooth; 31-35-(38), in diameter, 27-30» long.
Dwarf male plants unicellular, 8-124 in diameter, 13-16, long.
Mich.
Oedogonium polyandrium Prescott 1944, p. 355
P]. 42, Figs. 7-9
Nannandrous; idioandrosporous (?). Vegetative cells slightly
capitellate, 4.5-5.4, in diameter, 14-30» long. Oogonia solitary;
ovate or broadly ellipsoid; operculate; opening superior; 17-19» in
diameter, 27-28, long. Oospores ovate; nearly filling the oogonia;
outer spore wall with coarse sparsely arranged scrobiculations or
shallow pits; middle and inner layers of the spore wall smooth;
15-17 in diameter, 22-25. long. Dwarf male plants 2-celled,
numerous; on the oogonia; stipe 4.5. in diameter, 14-16, long.
Antheridia exterior (?).
This species has a combination of characteristics which make it
quite unlike any other. It should be compared, however, with Oe.
longatum, which is similar in size, but in which the outer layer of
the oospore wall is smooth. Also in Oe. longatum the dwarf male
plants are distinctly curved or reflexed. Skuja (1932, p. 59) describes
the oospore wall as having the middle layer pitted.
Attached to grass in a bog. Wis.
Oedogonium pseudoplenum Tiffany 1934, p. 326
Pl. 40, Fig. 9
Nannandrous; idioandrosporous. Vegetative cells capitellate, (12)-
15.6-16.5-(17)» in diameter, (36)-54.6-120, long. Oogonia 1-8;
globose; operculate; division median and wide; 36—40-(42)» in
diameter, (36)-389-41-(53), long. Oospores depressed-globose; not
filling the oogonia; wall smooth; (30)—31.2-33, in diameter, (27)-
30-31, long. Dwarf male plants unicellular; on the oogonia; 8. in
diameter, (12)—14—15y long.
In a Sphagnum bog. Wis.
[ 202 |
Oedogonium sinuatum (Trans.) Tiffany 1934, p. 325
Nannandrous; idioandrosporous. Vegetative cells undulate (with
4 undulate constrictions), (13)-19-26» in diameter, 48-110, long.
Oogonia 1-2, subglobose or ellipsoid-globose; operculate; division
inferior; 56-68 in diameter, 45-80 long. Oospores globose; not
filling the oogonia; wall smooth; 42-60,» in diameter, 42-56, long.
Dwarf male plants elongate-obconic, on the suffultory cell. (Typical
plant not found in our collections. )
Oedogonium sinuatum fa. seriatum Prescott 1944, p. 354
Pl. 40, Fig. 2
Vegetative cells undulate and capitellate, with 4 median undula-
tions; 22-25 in diameter, 48-59.2-(140) long. Oogonia in series
of 4 or 5; operculate; division inferior; 62-67» in diameter, 62-72
long. Oospores globose; not filling the oogonia; wall smooth; 55.54
in diameter. Dwarf male plants usually crowded on the suffultory
cell. Antheridia exterior (?), 10.9 in diameter.
This form has some features resembling Oe. undulatum, with
which it should be compared. The principal difference is the seriate
arrangement of the oogonia in our specimens.
Attached to overhanging grass in a Sphagnum bog ditch. Wis.
SECTION 9
Nannandrous—Gynandrosporous—Operculate
Oedogonium ambiceps (Jao) Tiffany 1937, p. 79
Pl. 37, Figs. 7-9
Nannandrous; gynandrosporous. Vegetative cells distinctly capi-
tellate, (9)-12-13. in diameter, 22-424 long. Oogonia solitary,
depressed-globose, with 8-10 median longitudinal bulges separated
by narrow creases, or sometimes by broad depressions; operculate;
division inframedian; 32—37—(38) in diameter, (19)—29.6—33p,
long. Oospores depressed-globose; nearly filling the oogonia; wall
thick, smooth; (19)—26—33, in diameter, (19)—25.9—27p long.
Dwarf male plants not observed. Androsporangia 11—13, in diam-
eter, 4p long.
The absence of dwarf male plants from our specimens and the
small proportions of the androsporangia make it possible to confuse
this with some other monoecious species, but the distinctive form
of the oogonium and its markings, together with the gynandrous
condition, are helpful in identification.
Attached to logs. Wis.
[ 203 ]
Oedogonium Areschougii Wittrock 1871, p. 122
Nannandrous; gynandrosporous. Vegetative cells cylindric, (8)-
9-12-(13), in diameter, 36-38-(75)» long. Oogonia 1-7; depressed-
globose or pyriform-globose; operculate; division median; (34)-35-
37-(39)» in diameter, 36-40» long. Oospores globose; not filling
the oogonia; wall smooth; (22)-23-25-(26) in diameter. Dwarf
male plants unicellular; on or near the oogonia; 6-7» in diameter,
12-13-(15)» long.
In a lily pond. Wis.
Oedogonium Areschougii var. contortofilum Jao 1934a, p. 199
Pl. 40, Figs. 6, 7
Somewhat larger throughout (in our specimens) than the typical
plant. Vegetative cells slightly capitellate, forming spiral] twists
especially just above the oogonial series, in which there may be as
many as 7; 7-12-(15.6)) in diameter, 54-60, long. Oogonia 36—-41p,
in diameter, 30-31 long. Dwarf male plants unicellular; on the
oogonia or near them. Oospores globose, 31p in diameter, 29-30
long.
Ree ate variation was noted in the amount of twisting
exhibited by this variety in different habitats. The suggestion
naturally presents itself that the spiral character of the filaments
is related to environmental factors. It is known that reaction to
parasitism frequently causes bending in filamentous algae, although
in these cases no parasitic organisms were observed.
On submerged wood. Wis.
Oedogonium ciliatum { Hass.) Pringsheim 1856, p. 227
Nannandrous; gynandrosporous. Vegetative cells cylindric, 14-24,
in diameter, 35-921 long. Oogonia 1-7; ovate or ovate-ellipsoid;
operculate; division superior to supreme; 43-50 in diameter, 55-72y
long. Oospores ovate to subellipsoid-globose; nearly filling the
oogonia; wall smooth; 40-47» in diameter, 44-57» long. Antheridia
8—10p. in diameter, 10-11, long.
Mich.
Oedogonium Croasdaleae Jao 1934a, p. 202
Pl. 41, Fig. 11
Nannandrous; gynandrosporous. Vegetative cells cylindrical, (20)-
25-28-(30) in diameter, 95-105-( 230)» long. Oogonia usually 3-4
in a series (rarely solitary); subovate or ellipsoid (sometimes sub-
quadrangular-ellipsoid ); operculate; division superior; (56)-58—
[ 204 |
62-(77) in diameter, 86-96-(116)» long. Oospores filling the
oogonia and the same shape; outer spore wall smooth; middle layer
with coarse, anastomosing, longitudinal costae; (54)—55-62-(73)
in diameter, (77)—79-94-(105) long. Dwarf male plants 10-15.
in diameter, 55-60-( 62) » long.
In a roadside swamp; attached to submerged aquatics in a beach
pool. Wis.
Oedogonium decipiens Wittrock 1871, p. 126
Pl. 42, Figs. 13, 14
Nannandrous; gynandrosporous. Vegetative cells cylindric or
slightly capitellate, (9)-10-12, in diameter, (28 )—-30-78-( 80) » long.
Oogonia solitary; subglobose; operculate; division median; (30)-
33-36-(38) in diameter, (27)-30-40» long. Oospores depressed-
globose, (25)-28-33-(34) in ‘diameter, (23)-25-28-(30)p long.
Dwarf male plants unicellular, 7» in diameter, 13-14-(15), long.
In several soft water and acid habitats. Mich., Wis.
Oedogonium decipiens var. africanum Tiffany 1929, p. 74
Pl. 41, Fig. 2
Vegetative cells capitellate; filaments frequently twisted; 9-9.2—
(13), in diameter, 25-30-(60) long. Oogonia globose; (25 )-29.6—
32 in diameter, (23)-27-28.6. long. Antheridia 6» in diameter,
Tp. long.
On overhanging grass. Wis.
Oedogonium decipiens var. dissimile (Hirn) Tiffany 1937, p. 68
Pl. 42, Figs. 11, 12
Vegetative cells capitellate, 8-11-(14)» in diameter, (20 )-55-
(65) long; oogonia (28)-33.3-354 in diameter, (23)-29.6-38»
long; oospores (23)-30-(34), in diameter, 21-(30)p long. Andro-
sporangium 9.2 in diameter, 8» long. Antheridia 8» in diameter.
Common in swamps and lakes. Mich., Wis.
Oedogonium hians Nordstedt & Hirn in Hirn 1900, p. 227
Pl. 40, Fig. 10; Pl. 42, Fig. 10
Nannandrous; gynandrosporous. Vegetative cells slightly capitel-
late, 9-14.8-(18), in diameter, 37-48-(145) » long. Oogonia 1 or 2;
subglobose or subovoid; operculate; division superior; 37-48 in
diameter, (40)-45-60—( 80) long. Oospores globose; quite or nearly
filling the oogonia; wall smooth; 30-31.4-( 40)» in diameter, 32-34—
(40) long. Dwarf male filaments 2-celled, on the suffultory cell.
[ 205 }
Antheridia exterior, 6-8. in diameter, 5-6. long. Suffultory cell
(26)-32-34y in diameter, (46 )-—50-53.6—( 80) » long.
Attached to grass in a small northern pond in sand hills. Wis.
Oedogonium macrandrium Wittrock 1871, p. 180
Pl. 41, Fig. 1
Nannandrous idioandrosporous (or gynandrosporous?). Vege-
tative cells cylindric, 14.8—16—(20), in diameter, 40—51.8—(100) u
long. Oogonia 1—4; sub-globose or ovate-globose; operculate; di-
vision superior; 36—42, in diameter, (43)—48—154, long. Oospores
globose; wall smooth; (31)—34—37, in diameter. Dwarf male
plants 2- or 4-celled; stipe 14.8, in diameter, 33.3y long; scattered
on the female plant. Antheridia exterior, 7.4—-10» in diameter,
7—10, long.
In soft water bog lakes. Mich., Wis.
Oedogonium michiganense Tiffany 1927, p. 205
P]. 43, Figs. 9-11
Nannandrous; gynandrosporous. Vegetative cells capitellate, 12-
24u in diameter, 80-160» long. Oogonia 1-7; globose to ellipsoid-
globose; operculate; division supreme; 50-64, in diameter, 50-80,
long. Oospores globose; sometimes filling the oogonia; wall smooth;
44-60» in diameter. Dwarf males 13-20y in diameter, 40-56, long.
Mich.
Oedogonium monile Berkeley & Harvey in Hooker 1859, p. 342
Nannandrous; gynandrosporous (?). Vegetative cells cylindric,
sometimes capitellate; 9-15» in diameter, 50-160, long. Oogonia
1-8; subovate or subglobose; operculate; division superior; 80-39
in diameter, 30-56 long. Oospores globose or subglobose; outer
spore wall smooth, median wall scrobiculate; 28-38, in diameter.
Antheridia quadrate, 7» in diameter. Suffultory cell 21—29—(32) p
in diameter.
Mich.
Oedogonium oelandicum Wittrock 1875, p. 17
Nannandrous; gynandrosporous. Vegetative cells capitellate, 10—
15, in diameter, 25-125, long. Oogonia 1-7; depressed-globose, with
12-16 prominent longitudinal ribs in the median portion; operculate;
division supramedian and broad; (29)-31-40p in diameter, 25-32y
long. Oospores depressed-globose; almost completely filling the
oogonia; wall smooth; 25-36, in diameter, 23-30, long. Dwarf male
plants unicellular; on the oogonia; 7-8, in diameter, 12-15, long.
Mich.
[ 206 |
Oedogonium oelandicum var. contortum Prescott 1944, p. 355
Pl. 42, Figs. 1-3
A variety differing from the typical by its contorted filaments
which sometimes form short spirals, several of which may occur in
one filament. Vegetative cells 11-12 in diameter, distinctly capi-
tellate. Oogonia much shorter than wide; depressed-globose; 29-30,
in diameter, 20-21.5. long. Oospores depressed-globose; the wall
smooth; 25-271 in diameter, 18-20» long. Dwarf male plants
unicellular; on the oogonia.
Attached to grass in small lakes. Wis.
Oedogonium rugulosum Nordstedt 1877, p. 28
Pl. 44, Figs. 14, 15
Nannandrous; gynandrosporous. Vegetative cells cylindric, (4)-
8-9.5. in diameter, (10)-11.7-19.5-(35) long. Oogonia solitary
(rarely 2 together); ellipsoid or globose-ellipsoid; operculate; di-
vision superior; (16)—20, in diameter, (22)-25.4-29, long. Oospores
globose or subglobose; wall smooth; 15-17.5-(18) in diameter,
17.5-19.7-(25)» long. Dwarf male plants short; on the oogonia.
Antheridia exterior, 5. in diameter, 6 long. Basal cell of female
filament 7.8» in diameter, 11-13.6-(14)» long.
In a roadside fosse. Mich., Wis.
Oedogonium rugulosum fa. rotundatum (Him) Tiffany
1936, p. 169
Pl. 89, Figs. 9, 11, 12
Vegetative cells cylindric or slightly capitellate, 5-6.8-(8) in
diameter, 27-30-(31) long. Oogonia 1-3; ovate or globose-ellipsoid;
division superior; (19)-20-23-(30), in diameter, (20)-29-30, long.
Oospores globose or ellipsoid-globose; nearly filling the oogonia;
wall smooth; 18-20—(22), in diameter, 22-25, long.
Our plants are in agreement with this variety except that the
cells have a tendency to be capitellate.
With the typical plant. Wis.
SecT1on 10
Nannandrous—Idioandrosporous or Gynandrosporous—Operculate
Oedogonium acrosporum DeBary 1854, p. 47
Pl. 41, Fig. 7
Nannandrous; gynandrosporous or idioandrosporous. Vegetative.
cells cylindric, (12)—15-19.5-(21), in diameter, (34)—40-68-(125) »
long. Oogonia solitary; ellipsoid; terminal; wall ridged internally
[ 207 ]
with 23-30 longitudinal ribs; operculate; division superior; (30')-
35-48, in diameter, 50-63, long. Oospores filling the oogonia, with
as many ridges on the membrane as the ribs on the wall of the
oogonia, and fitting in between them. Dwarf male plants 2 to 4
cells long, the stipe elongate; 2- or 3-celled; attached to the suffultory
cell, Antheridia exterior, 7» in diameter, 11, long.
This species is separated from its varieties mostly by the stout
suffultory cell and by the somewhat longer oogonia, with more
ridges.
Common in several lakes and Sphagnum bogs. Wis.
Oedogonium acrosporum var. boreale Wolle 1887, p. 84
Vegetative cells 7.8-12u in diameter, 54.6-140, long. Oogonia
elliptical, with 11-15 longitudinal ribs; 30-3lp in diameter, 44-46y
long. Dwarf male plants 2-celled. Antheridia exterior, 9» in diameter,
11, long. Suffultory cell 15.6, in diameter, 39, long.
In acid and soft water lakes. Wis.
Oedogonium acrosporum var. bathmidosporum (Nordst.) Hirn
1900, p. 246
Pl. 41, Figs. 5,6
Vegetative cells (8)-12-17p in diameter, 46-54-(125), long.
Oogonia with few ridges (about 18 in our specimens); thick and
sometimes interrupted; 27.3-80—( 40)» in diameter, (37)-39-59, long.
Dwarf male plants 2-celled; on the suffultory cell, which is enlarged
to 22. Antheridia exterior, 5-8—(10)» in diameter, 9-12—(18) » long.
Specimens collected in Wisconsin have the characteristics of this
variety except that the ribs are not crenulate as originally described
for it.
Common in several lakes and Sphagnum bogs. Mich., Wis.
Oedogonium acrosporum var. majusculum Nordstedt 1878, p. 21
Pl. 41, Fig. 10
Vegetative cells relatively longer; (14)—16-20-(21), in diameter,
50-125-(165) long. Oogonia 45-58. in diameter, 50-65.5—-(70)
long. Oospores 46-55» in diameter.
Attached to grass in a ditch through a Sphagnum bog. Mich., Wis.
Oedogonium macrospermum West & West 1897a, p. 472
Pl. 41, Fig. 12
Nannandrous; gynandrosporous or idioandrosporous. Vegetative
cells cylindric, (10)-16-18.5, in diameter, (80)-55-57—(80) » long.
Oogonia solitary; subglobose; operculate; division median; (39)-
[ 208 ]
40-44.4-(46) in diameter, 35-38-(44) long. Oospores depressed-
globose; with a smooth wall; 36-38.5-( 44) in diameter, (32)-36.5-
42u long. Dwarf male plants short; usually 2-celled; on the suffultory
cell. Antheridia exterior; stipe of dwarf male 9-14.81 in diameter.
Antheridia 7-10, in diameter, (6 )-11—16—( 22), long.
On submerged aquatics in shallow water of a slough. Mich., Wis.
Oedogonium subplenum Tiffany 1934, p. 326
Pl. 40, Fig. 8
Nannandrous; gynandrosporous or idioandrosporous. Vegetative
cells slightly capitellate, (7)-8-12. in diameter, 23-80, long.
Oogonia solitary; depressed-globose or pyriform-globose; operculate;
division median; 29-35-(38) in diameter, (26)-29-33-(41), long.
Oospores globose; not filling the oogonia; 21-22.4—(28) in diam-
eter, 19-26 long. Dwarf male plants 1-celled; on the oogonia; 6-7p
in diameter, 6-10, long.
In shallow water at edge of a Sphagnum bog. Wis.
Oedogonium undulatum (de Bréb.) A. Braun in DeBary
1854, p. 94
Pl. 40, Figs. 3-5
Nannandrous; gynandrosporous or idioandrosporous. Vegetative
cells capitellate and 4-undulate, except the basal cell which is
elongate and smooth; 15.6-18-(22), in diameter, (15.8)—45-100-
(110) long. Oogonia solitary (sometimes 2 together); globose or
ellipsoid-globose; operculate, the division inferior; (48)-50.7-55,
in diameter, (50)-54.6-56-(75) long. Oospores globose; filling
the oogonia; wall smooth; 42-50 in diameter. Dwarf male plants
on the suffultory cell or nearby. Antheridia interior; 9» in diameter.
Very common in many soft water and acid habitats. Mich., Wis.
Oedogonium undulatum fa. senegalense (Nordst. ) Hirn 1900, p. 261
Pl. 44, Fig. 4
Vegetative cells with 3 median undulations and of somewhat
narrower proportions than in the typical plant; 18-20, in diameter,
48-80» long. Oospores 38, in diameter.
Attached to overhanging grass in a ditch through a Sphagnum
bog. Wis.
ORDER CHLOROCOCCALES
This large order is composed of a great variety of plants which
are l-celled or which form colonies of rather definite shape. The
[ 209 ]
cells may be adjoined or merely inclosed by a colonial mucilaginous
envelope. In a few forms the cells are connected by strands formed
by the remains of old mother-cell walls. The chief characteristic
which all forms have in common is a negative one, namely, the
inability to multiply by cell division in the vegetative state. Auto-
spores are common in vegetative reproduction, as is also the habit
of forming daughter colonies within each cell of a mature colony.
Zoospores are used by some forms in asexual reproduction and
isogametes are the rule in the genera which have sexual reproduc-
tion.
The cells vary widely in shape, being globose, ovate, acicular,
fusiform or polyhedral. Although most forms are uninucleate, a few
are coenocytic and hence are regarded by some phycologists as the
likely ancestors of the Siphonales. The form of the chloroplast varies
almost as much as the cell shape. There may be numerous ovate
discs, parietal plates, networks, or in some genera cup-shaped
chloroplasts. Pyrenoids may be lacking, but usually there are 1 to
several. One family, the Endosphaeraceae, is unique in being diploid
in the vegetative state.
Key to the Families
1. Unicellular, relatively large, and irregular in shape; wall very
wide, lamellated, and not uniform in thickness; inhabiting
the tissues of higher plants, or free-living _____ ENDOSPHAERACEAE
1. Unicellular or colonial; cells varied in shape but not irregular; wall
of uniform thickness and not definitely lamellated; free-living
or attached, rarely ‘subaenialwiss “hee ee ee 2
Ov Pree-foating, or adherentoon) soil = 6 eee 3
2. Attached and sessile, unicellular; cells fusiform — CHARACIACEAE
3. Cells cylindrical and forming a macroscopic network, or
triangular or polyhedral and united to form either a flat
and circular, or globose coenobium (colony) HYDRODICTYACEAE
8. Cells not cylindrical, and not forming colonies as above... eae 4
4. Unicellular, solitary or sometimes gregarious, free-floating (usually
on moist soil if adherent), reproducing by zoospores (rarely aplan-
ospores) which do not adhere to one another but which are liber-
ated separately from the parent cell (See Chlorella
OWE VET) MUN eects tras tet Rl ane akan Ant idli::ARRe baker ee nare inl enis3 Lance tat CHLOROCOCCACEAE
4.) Colomial:, or ‘solitary not, reproducing as ‘aboyes.)..1..5...022s0.sccseasenee- 5
5. Thallus a hollow, globular coenobium of spherical or
pyramidal cells, adjoined to neighboring cells by
processes, rarely by direct contact. Baie Waser BaeY Se 2 COELASTRACEAE
em hvallnasy mOtRAS Ta DOV Case) ec Theo ENN oad See al acl ae) 6
6. An irregular mass of mucilage, often darkly colored,
containing ovate or spherical cells at the periphery
(compare with Dimorphococcus in the Oocystaceae ) BOTRYOCOCCACEAE
GRIN te cas eu Ve ce 2 a FD A a ra a Pate ese 7
7. Cells solitary or in colonies of definite or indefinite shape; cells
variable in torm (spherical, ovate, lunate, polyhedral, etc. ),
not adjoined to one another; reproduction by autospores____ OOCYSTACEAE
7. Two to eight cells adjoined together or adherent to form
a pattern of definite shape (a linear series, stellate, or
cruciate ); reproduction by the formation of autocolonies
within the cells of the parent coenobium_——_-___ SCENEDESMACEAE
FAMILY CHLOROCOCCACEAE
In this family the cells vary in shape from spherical to fusiform or
spindle-shaped (represented in our collections by spherical cells
only ). The family is characterized by the use of zoospores in asexual
reproduction. These escape through a pore in the wall and separate
immediately. In some forms arrested zoospores (aplanospores ) may
function.
The plants are mostly solitary and free-floating, but in one genus
(Chlorococcum) cells are gregarious and sedentary, inhabiting
moist soil or other subaerial habitats. The cell wall may be smooth
or spiniferous. There is considerable variation in the form of the
chloroplast which may be a parietal or massive cup, or axial and
stellate, with 1 or more pyrenoids. In some species the cells become
much enlarged and in age multinucleate.
In the identification of members of this family a comparison should
be made with similarly shaped plants in the Oocystaceae.
Key to the Genera
1. Cells spherical or subspherical, inclosed in a wide,
longitudinally striated, spindle-shaped sheath. Desmatractum
i Gells'spherieal, not inclosedimiasheath= 2
2. Cells free-floating, solitary, the walls setiferous _._.-_______ 3
2. Cells sedentary, or rarely free-floating, solitary or gregarious on
moist earth or submerged substrates; wall smooth ._-_-_ = Chlorococcum
3. Setae gradually tapering from the base to apex Golenkinia
8. Setae thickened for a short distance in the basal portion,
then abruptly narrowed and tapering to apex Acanthosphaera
CHLOROCOCCUM Fries 1825, p. 356
Cells spherical, solitary or more often gregarious in amorphous
gelatinous clumps, or forming films on moist or submerged sub-
strates; cell wall thin and undecorated; chloroplast a thin parietal
plate covering the wall or nearly so, containing 1 pyrenoid; repro-
duction by 8-16 oblong zoospores with 2 flagella.
Species of Chlorococcum should be compared with Chlorella. See
note under that genus.
[ 211 ]
Chlorococcum humicola (Naeg.) Rabenhorst 1868, p. 58
PI. 45, Fig. 1
Cells spherical, solitary or in small clumps, variable in size within
the same plant mass; cells 8-20—( 25)» in diameter.
This species is luxuriantly represented on and about dead fish
and animal wastes along shores, forming green films in association
with Scenedesmus spp. and Euglena spp. Common on beach soils
and in moist aerial habitats. Mich., Wis.
Without a doubt, another common species, C. infusionum
(Schrank) Meneghini occurs in our region. It has larger cells than
C. humicola (15-45, in diameter) and is ordinarily found on sub-
merged substrates.
DESMATRACTUM (West & West) Pascher 1930b, p. 651
Cells globular, the wall thin, firm, and smooth, inclosed in a wide,
transparent or brownish spindle-shaped sheath which is longitud-
inally striated; and composed of 2 top-shaped halves which adjoin
at the midregion of the spindle; chloroplast solitary, a parietal cup
with 1 or 2 pyrenoids; reproduction by biflagellate zoospores or by
autospores.
This genus, as Bernardinella, was once placed in the Heterokontae.
Desmatractum bipyramidatum (Chod.) Pascher 1930b, p. 654
Pl. 46, Fig. 9
Characteristics as described for the genus; cells (with sheath) 12
in diameter, 22y long.
In acid waters; Sphagnum bogs. Mich.
ACANTHOSPHAERA Lemmermann 1899a, p. 118
Unicellular, spherical; free-floating; wall uniformly beset with
24 long, needle-like setae arranged in 6 tiers, 4 in each tier, about
the cell wall; setae thickened for about 14 their length from the base,
then abruptly narrowed to form slender spines; 1 parietal, lobed
chloroplast, covering most of the cell wall, with 1 pyrenoid.
Acanthosphaera Zachariasi Lemmermann 1899a, p. 118
Pl. 45, Figs. 4, 5
Characteristics as described for the genus; cells spherical with
numerous long setae with thickened bases; cells 9-14.5 in diameter
without setae; length of setae 30-35p.
In plankton. Wis.
[ 212 ]
GOLENKINIA Chodat 1894, p. 305
Cells spherical, solitary and free-floating, the wall furnished with
long, slender tapering setae; false colonies sometimes formed by the
interlocking of setae; cells rarely inclosed by a thin, mucilaginous
envelope; chloroplast a parietal cup covering most of the cell wall,
containing 1 pyrenoid; reproduction by autospores and zoospores.
This genus seems to belong with the Oocystaceae, and it should
be compared with spherical members of that family. The justification
for placing it with the Chlorococcaceae is the report that zoospores
are formed in asexual reproduction, a method not used by the
Oocystaceae.
Key to the Species
Cells 15-184 in diameter; setae 12-18 long G. paucispina
Cells 7-15u in diameter; setae 25—45u Via oks oe I be ee et G. radiata
Golenkinia paucispina West & West 1902, p. 68
Pl. 45, Fig. 2
Spherical, free-floating unicells with a few short setae arising from
all sides of the cell wall; 1 cup-shaped chloroplast, with 1 pyrenoid;
cells 15—18, in diameter; setae about 16, long.
Rare, in the plankton of several lakes. Wis.
Golenkinia radiata (Chod.) Wille 1911, p. 57
Pl. 45, Fig. 3
Spherical, free-floating unicells with long and very slender setae;
cells usually solitary but often in false colonies of 4 as a result of the
interlocking of the setae; cells 7-15, in diameter; setae 25-45, long.
Rare; in euplankton. Mich., Wis.
FAMILY ENDOSPHAERACEAE
In this family the plants are unicellular, large, irregularly oblong
or ovate in shape, free-living, parasitic, or (in our region) endo-
phytic, embedded in the tissues of higher plants or in the mucilage
of other algae. The chloroplasts are parietal in young cells but be-
come massive and axial in older plants, with several pyrenoids. The
wall is thick and lamellate, or has knob-like elongations. The family
is unique in that the single cells are diploid, being but enlargements
of the zygospore formed by the union of isogametes. Reduction
division occurs when the cell contents divide to form as many as
256 biflagellate protoplasts. It is possible that zoospores, as well as
gametes, are produced in this way.
[ 213 ]
Key to the Genera
Inhabiting ‘the tissues of Lemnass =) San eee Chlorochytrium
Free-living or embedded in the mucilage of other algae ______ Kentrosphaera
CHLOROCHYTRIUM Cohn 1875, p. 102
Unicellular, oblong or broadly ellipsoid, often irregular in outline,
formed when a zygote germinates and sends a tubular elongation
into the tissues of Lemna, the cell contents migrating into the tube
and then enlarging among the host cells, the entrance tube persisting
as a knob-like extension of the wall, which is thick and lamellate;
chloroplast at first parietal, later becoming radial and massive;
reproduction by division of the cell contents into a large number of
biflagellate isogametes or zoospores.
Chlorochytrium Lemnae Cohn 1875, p. 102
Pl. 45, Figs. 6,7
See characters of the genus; cells broadly ellipsoid or ovate, with
1 or more knob-like extensions; wall thick and lamellate; cells 60-
100, in diameter, inhabiting the tissues of Lemna trisulca.
In host plants collected from water of marshy lakes; in roadside
swamps. Mich., Wis.
KENTROSPHAERA Borzi 1883, p. 87
Unicellular, often crowded and intermingled with other algae,
sometimes living in the mucilage of colonial Myxophyceae; cells
irregularly ovate, ellipsoid, or sub-cylindric; walls lamellated, irreg-
ularly thickened with knob-like outgrowths; chloroplast axial, with
extensions flattened at the wall to form irregularly shaped processes;
one pyrenoid.
Kentrosphaera gloeophila (Bohlin) Brunnthaler 1915, p. 68
Pl. 45, Figs. 8-10
Characters of the genus; cells broadly ovate, or ovoid or elliptic,
with knob-like thickenings of the lamellate wall, 18-20, in diameter,
25-30u long.
(For a discussion of the nomenclature of this species see Moore,
1917; G. M. Smith, 1983; Bristol, 1920. )
Among thick clots of blue-green algae. Wis.
FAMILY CHARACIACEAE
This is a small family of which there is but a single genus
(Characium) represented in our collections. ( Actidesmium, reported
from California and arctic Alaska, has spindle-shaped, free-floating
[ 214 ]
cells which are arranged in stellate clusters, adjoined to form com-
pound colonies by gelatinous strands.) Characium, which is much
more common, has spindle-shaped or ovoid cells growing on other
algae, on submerged aquatic plants, or on microfauna. There are
1 or more parietal chloroplasts, each with a pyrenoid (sometimes
several). The cells are mostly uninucleate. Biflagellate zoospores,
formed 2-128 in a cell, escape through an apical or lateral pore.
CHARACIUM A. Braun in Kuetzing 1849, p. 208
See characteristics as described for the family; cells variously
shaped, ovoid, fusiform, or cylindric, attached to a substrate (sub-
merged plants, larger algae, microfauna) by a stipe (usually) and
often with a basal attaching disc; rarely sessile; chloroplasts 1 or
several parietal plates which sometimes become diffuse; pyrenoids
1 to several, although rarely there are none; food reserve in the form
of starch.
Key to the Species
1. Cells epizoic on crustacea, often specific as to host -__.-_----------------_-_---- 2
1. Cells epiphytic on miscellaneous plants but especially
Gry HAUIeR Osi Al gag wise ies ewe tage dre gs Cote ea Ae 5
ame clisnrounGee cat the apes. 1.0 restive on ther ee 3
2~ Cells narrowed to-aispinejatithe apex, <= en ee 4
3. Cells broadly ovoid or pyriform, on a short stout stalk. C. Debaryanum
8. Cells elongate-ellipsoid or narrowly obovoid_.......-.--_----.---.. C. Hookeri
4. Cells fusiform or slightly crescent-shaped, on a long, needle-like
stipe without a holdfast at the base _________.-..--.-..--------------- C. limneticum
4. Cells elongate-cylindric, from a stipe which has a
forked hizoidal sholdfast. 22-04 5 Se C. gracilipes
5. Cells broadly pyriform or broadly ovate, or ovoid —.._.__-__-__---____-_-- 6
5. Cells narrowly ovoid, fusiform, lanceolate, falcate or cylindrical 8
6. With a very slender stipe, 1 to 1} times as long
esa reyes) || oo ht Sis aU es Vaca), See C. stipitatum
6. With a stout stipe, much shorter than the length of the cell body a
7. Cells broadly ovate, 10-12 wide____-_-___-__ C. obtusum
Weg @ells pyxitorm, 1d—loy widest C. operculum
8. Cells elongate-fusiform, narrowed anteriorly but
bluntlyazcunded atthe tap. C. Rabenhorstii
8. Cells lanceolate, falcate, or cylindric, ending in
anvapiculation Oryspine ssc. se... ite 2 os sul 9
9. Stipe enlarged at the base to form an attaching disc ____________________- 10
O. 7Stipenwithout apbasalvattachmp dise < e 12
IOs Cells straight,cerect, the stipe short 22s C. Pringsheimii
1G. Gellsystrongly7curved ormalleate .=2 52 PE 11
I, ‘Gells: lanceolate or faleate: = spss Oe UPR ele C. rostratum
11. Cells broadly and unsymmetrically ellipsoid, convex on one
margin, nearly straight on the other_____---_-_______. C. ornithocephalum
[ 215 ]
12. Cells fusiform, oblong or ovate, straight or nednly(so == 13
12. Cells strongly curved —_—_-————————-—————— == 14
13. Cells 15—20u in diameter_____------------------------—----------------___- C. acuminatum
13. Cells 4-8» in diameter___-.---.----------—--------------------------------------- C. ambiguum
14. Stipe stout and tubular, with irregular margins C. curvatum
14. Stipe long and slender_______---________----_- C. falcatum
Characium acuminatum A. Braun in Kuetzing 1849, p. 892
Pl. 46, Fig. 7
Cells oblong or narrowly ovate, narrowed anteriorly to form a
short apiculation, acuminate; stipe short; cells 15-20» in diameter,
35-40 p long.
Attached to filamentous algae. Mich., Wis.
Characium ambiguum Hermann 1863, p. 26
Pl. 45, Fig. 11
Cells solitary, lance-shaped, fusiform or ensiform, narrowed to a
sharp point anteriorly, tapering posteriorly to a fine hair-like stipe,
without an attaching disc; chloroplasts 1-3; cells 4-8, in diameter,
25-30, long.
Attached to filamentous algae; tychoplanktonic. Mich., Wis.
Characium curvatum G. M. Smith 1918, p. 641
Pl. 45, Figs. 12, 13
Cells lunate or sickle-shaped, either sharply or bluntly pointed;
stipe stout, without an attaching disc; chloroplast with or without
a pyrenoid; cells 3-6, in diameter, 13-22 long, including stipe.
Epiphytic in the mucilage of colonial algae; tychoplanktonic. Wis.
Characium Debaryanum (Reinsch) DeToni 1889, p. 628
Pl. 46, Fig. 19
Cells oblong or ovoid, broadly rounded anteriorly, narrowed
below into a stout stipe with a basal adhesive disc or swelling; cells
20-25, in diameter, 30-40, long.
Epizoic on copepods. Mich.
Characium falcatum Schroeder 1898, p. 23
Pl. 45, Fig. 14
Cells sickle-shaped, ending in a long sharp point; stipe long and
slender, without an attaching disc; 1 chloroplast without a pyrenoid
(?); cells 4.2-6.5p in diameter, 36-50, long.
This species is somewhat like C. rostratum but is separable on the
basis of the attaching disc which that species possesses. Also, C.
[ 216 ]
falcatum has a long, colorless apical beak not present in the former
species. It should be compared also with Characiopsis longipes.
On filamentous algae in shallow water of lake margins; swamps.
Mich., Wis.
Characium gracilipes Lambert 1909, p. 65
Pl. 45, Fig. 16
Cells elongate cylindric, straight or very slightly curved, abruptly
tapering anteriorly and extended to form a long, hyaline hair, and
abruptly tapering below to a slender stipe with 2 or 3 fine, rhizoidal
branchings at the base; chloroplasts variable, 1-32 in number with
a single pyrenoid in each; cells 5-14» in diameter, (70)-80-480, long.
Epizoic on the anterior appendages of crustacea. Mich., Wis.
Characium Hookeri (Reinsch) Hansgirg 1888, p. 128
PI. 45, Fig. 17
Cells mostly gregarious on Cyclops, club-shaped to subcylindric;
stipe long or short, without an attaching disc; chloroplast 1, with 1-3
pyrenoids; cells 9-12. in diameter, 27-30, long.
On Cyclops in lakes and ponds; euplanktonic and tychoplanktonic.
Wis.
Characium limneticum Lemmermann 1903c, p. 81
Pl. 45, Fig. 18
Cells fusiform or lunate (rarely almost straight), extended an-
teriorly into a long, sharp, spine-like tip, tapering posteriorly rather
abruptly to form a long narrow stipe, without a basal attaching disc;
chloroplasts 1-8, arranged to form a series of parietal bands; cells
5—14p in diameter, 25-110, long, including stipe.
Epizoic on Diaphanosoma brachyura in lakes. Mich., Wis.
Characium obtusum A. Braun 1855, p. 39
Pl. 45, Fig. 20
Cells oblong-ovate; stipe short and fairly thick; cell rounded
anteriorly and furnished with a thickened plug at the apex; chloro-
plast parietal, with a single pyrenoid; cells (8)—10—12» in diam-
eter, 12.9—14.8—(33), long.
Attached to filamentous algae; lakes and Sphagnum bogs. Mich.,
Wis.
Characium operculum Ackley 1929, p. 304
Pl. 46, Fig. 18
Cells broadly pyriform on a short thick stipe with a basal
attaching disc, broadly rounded anteriorly and furnished with an
[ 217 ]
apical thickened plug; chloroplast (?); cells 13-15p in diameter,
19-24y long.
On filaments of Desmidium. Mich.
Characium ornithocephalum A. Braun 1855, p. 42
Pl. 46, Fig. 14
Cells broadly and unsymmetrically ellipsoid, convex on one side,
nearly straight on the other, abruptly narrowed anteriorly to form
a sharp apiculation, the cell body set at an angle and curved away
from a long stipe with a basal attaching disc; chloroplast laminate,
parietal, with a conspicuous pyrenoid; cells 25-33p long, without
stipe.
on submerged plants, especially filamentous algae. Mich.
Characium Pringsheimii A. Braun 1855, pp. 37, 106
Pl. 45, Fig. 21
Cells narrowly elongate-ovoid to fusiform, erect but with a short
oblique tip; stipe short; chloroplast a laciniate plate with | pyrenoid;
cells 7.8-9, in diameter, 13-16 long.
Attached to Tribonema filaments in a roadside fosse. Mich., Wis.
Characium Rabenhorstii DeToni 1889, p. 625
Pl. 46, Fig. 27
Cells elongate-fusiform or lanceolate; narrowed anteriorly but
with a bluntly rounded apex; narrowed below to a long slender
stipe, about % the length of the cell body, with a brown basal
attaching disc; cells 8-9, in diameter, 16-18y long.
On filamentous algae. Mich.
Characium rostratum Reinhard 1876, ex Printz 1914, p. 41
Pl. 45, Figs. 22, 23
Cells lanceolate-faleate with curved apex; stipe long and slender
from an attaching disc; chloroplast laminate, nearly covering the
entire wall; cells 7.81 in diameter, 40-45» long, including the stipe.
Attached to Tribonema filaments in a roadside fosse. Mich., Wis.
Characium stipitatum (Bachm.) Wille 1911, p. 45
Pl. 45, Fig. 15
Cells ovate to subspherical or pyriform; stipe slender and tapering
from the base of the cell, without an attaching disc; chloroplast
parietal along the apical wall, with 1 pyrenoid; cells 5-8» in diam-
eter; stipe 10-16, long.
Epiphytic on Coelosphaerium Naegelianum; generally distributed.
Mich., Wis.
[ 218 ]
FAMILY HYDRODICTYACEAE
The members of this coenocytic family are morphologically very
distinctive, although extremely variable. All forms are free-floating,
but some are found only in the tychoplankton. In one genus,
Hydrodictyon, there are cylindrical cells arranged to form a mac-
roscopic, closed cylindrical net. In other genera the cells are
triangular or polyhedric in outline and are arranged to form flat or
spherical coenobia. The number of cells in the colony varies from
2 to 64 in the plate type of colony, whereas in Hydrodictyon several
hundreds of cells are involved, always in multiples of 2. The
chloroplast is parietal, either a continuous or perforate sheet, with
1 to many pyrenoids.
Like other families in this order, vegetative reproduction by cell
division does not occur. The most common method of reproduction
is by the formation of daughter colonies within the parent cell,
these developing from retained zoospores. Sexual reproduction is
by biflagellate isogametes.
Key to the Genera
1. Thallus a cylindrical closed reticulum of cylindrical cells
which form: 5-sor 6-sided: meshes. Hydrodictyon
ienhiallussnotparcyundiscal. nee a= 5 4. ane et eo ES oa 2
2. Thallus composed of 2 triangular or trapezoidal cells with
PRG Er MASE Siac IR eel esa cf Euastropsis
2P Shallus composed of more than 2.cells <2. = 20 3
3. Thallus a flat, circular plate of polygonal cells ...___»____ Pediastrum
3. Thallus a spherical colony of spine-bearing cells on stalks
radiating. tom a common center... 2 Sorastrum
HYDRODICTYON Both 1800, p. 531
Thallus macroscopic, composed of cylindrical cells which are
adjoined at their ends to form a cylindrical net with 5- or 6-sided
meshes; chloroplast at first a parietal plate with a single pyrenoid,
later becoming a reticulum covering the entire wall and containing
many pyrenoids; cells multinucleate.
Hydrodictyon reticulatum (L.) Lagerheim 1883, p. 71
Pl. 47, Fig. 1
Characteristics as described for the genus; cells up to 200, in
diameter, as much as 1 cm. long when fully enlarged, forming a
net up to 2 dm. in length; chloroplast a much diffused reticulum,
light yellow-green color in the plant mass, especially at maturity.
This is a plant which prefers quiet water and is found in lakes
where there is little wave action, in pooled streams, and in the
[ 219 ]
shallow water of swamps and marshes. Its rapid rate of reproduction
(daughter nets formed within each cell of the parent net) makes it
possible for H ydrodictyon to develop luxuriant growths in favorable
habitats. Thick floating mats often result, and sometimes unbal-
anced biological conditions are produced. In some sections it
becomes an obnoxious weed, clogging filters, drains, etc. It is so
definitely confined to hard water that it may be used as an index
organism for a high pH. In the far West it finds ideal growing
conditions in the alkaline water of irrigation reservoirs and ditches.
Common in a large number of lakes, mostly hard water; generally
distributed. Mich., Wis.
EUASTROPSIS Lagerheim 1895, p. 20
Thallus free-floating, composed of 2 flattened, triangular or
trapezoidal cells adjoined along one wall, the lateral free margins
converging and slightly concave, the apex deeply notched; chloro-
plast 1, parietal, with 1 pyrenoid.
Euastropsis Richteri (Schmidle) Lagerheim 1895, p. 20
Pl. 47, Fig. 2
Characters as described for the genus; cells 4.5-25p in diameter,
5-20p long; 2-celled colony 4.5-25 wide, 10-40» long.
Rare, in plankton. Wis.
PEDIASTRUM Meyen 1829, p. 772
Coenobium a free-floating, circular, monostromatic disc of cells
which may be continuous or perforate; peripheral cells of the disc
with 1 or 2 lobes or processes, or merely emarginate without
processes; interior cells either the same shape as the marginal ones
or different; chloroplast a parietal reticulum, covering the wall,
with 1 pyrenoid; cells multinucleate.
Because the plates of Pediastrum are formed by the juxaposition
of zoospores developed within a vesicle which is extruded from the
mother cell, it not infrequently happens that irregularly formed or
abnormal coenobia develop when the zoospores fail to align them-
selves in one plane. Hence coenobia may be found in which some
cells overlie others. For a criticial study of this genus the reader is
referred to Bigeard (1933) and Harper (1916, 1918).
Key to the Species
1, Outer free wall of the peripheral cells extended to form
a sinple,‘horn-like projection. 2s eee P. simplex
1. Outer free wall of peripheral cells with 2 to 4 projections, or
merely ‘emarginate; not forming. processes... ee 2
[ 220 ]
. Outer free walls of peripheral cells deeply incised or
emarpinate todform 2 to 4 processes eee 5
. Outer free walls of peripheral cells not incised or lobed; processes, if
any, only prominent undulations or knob-like thickenings on the wall 3
. Peripheral cells quadrangular-rhomboid, 5-6 sided, the outer margins
bearing 1-2 stump-like projections == P. integrum
sebernipheral) cellsenor tas: above ste serene is stadt 1 Sot ele a 4
. Peripheral cells with a single emargination, throwing the margin
of the colony into a series of undulations. P. muticum
. Peripheral cells with 2 shallow emarginations, forming 8 lobes which
do not project beyond the periphery of the colony. P. Braunii
. Lobes of the peripheral cells not in the same plane, but one
above the other as seen in surface view... P. Kawraiskyi
- Lobes of the peripheral cells in one plane. __-_____ 6
. Lobes of the peripheral cells elongate and tipped
by. a elobuilar swellinge ss. 21 235 r cet Ts P. glanduliferum
. Lobes of the peripheral cells without apical thickenings 7
. Colony entire, without perforations, or with but
Date W aint Uite oI CErshiGeS = a) cots et we or eA ee Ey th 8
euColony (Gistilictly,nertonate eset se. fe ge 12:
. Incision of the peripheral cells deep and narrow
sometimes linear and completely closed Seat ee 9
. Incision of the peripheral cells widely open __-_____-__________ 10
. Incision of the peripheral cells forming a closed sinus with the
sides nearly parallel, peripheral cells definitely 4-lobed______ P. obtusum
. Incision of the peripheral cells forming a sinus with converging
margins, outwardly widely open; peripheral cells
Hotpronunently 4A-loped = 1 ees er ss Vee SPE 9 ts P. tetras
wiGelliwall-smoothor granulate: 42.002... 6. oc cleceecsk P. Boryanum
pecelwallreticulate: 2. eet, rey Oe cee ee Uk A ie, oy 11
. Cell wall with fine, close reticulations; processes
ofeperipheral cellon girs. .< oert See ee eee et P. sculptatum
. Cell wall with coarse reticulations; processes of peripheral cells
short, or with a broad concave emargination between them __ P. araneosum
. Lobes of the peripheral cells bifurcate at their apices ____. P. biradiatum
. Lobes of the peripheral cells not bifurcate at their apices ___ P. duplex
Pediastrum araneosum (Racib.) G. M. Smith 1916, p. 476
[P. angulosum var. araneosum Raciborskil]
Pl. 47, Fig. 4
Colony entire, or with minute interstices; cells 5-sided; peripheral
cells 2-lobed; margin concave between the lobes, which are short
and are about as far apart as are the lobes of two adjacent cells;
wall with reticulate ridges; cells 15-32 in diameter.
Common in the tychoplankton and euplankton of many lakes;
generally distributed. Mich., Wis.
[ 221 ]
Pediastrum araneosum var. rugulosum (G. S. West)
G. M. Smith 1916, p. 476
[P. Boryanum var. rugulosum G. S. West]
Pl. 47, Fig. 3
A variety differing from the typical in having the adjoined cells
distinctly undulated or crinkly.
Euplanktonic and tychoplanktonic. Mich., Wis.
Pediastrum biradiatum Meyen 1829, p. 773
Pl. 47, Figs. 5, 6
Colony perforate, the peripheral cells deeply bilobed, the lobes
incised; cells adjoined along the lower part of their lateral walls;
inner cells bilobed, the lobes not incised, all walls concave; diameter
of cells 10—20z.
Common in the plankton of many lakes; generally distributed.
Mich., Wis.
Pediastrum biradiatum var. emarginatum fa. convexum
Prescott 1944, p. 356
Pl. 47, Figs. 7, 8
Colony perforate (clathrate), cells bilobed at the periphery, the
lobes bifurcate, the inner margin of the lobules convex; peripheral
cells adjoined along the lower part of their lateral margins only;
lobes of inner cells merely emarginate; cells up to 11.7» in diameter,
9.7-10p long; 16-celled colony 44-50, wide.
Rare, in Sphagnum bogs. Wis.
Pediastrum Boryanum (Turp.) Meneghini 1840, p. 210
Pl. 47, Fig.9; Pl. 48, Figs. 1,3
Colony entire; cells 5—6-sided with smooth or granular walls;
peripheral cells with outer margins extended into 2 blunt-tipped
processes; cells up to 14 in diameter, 21u long; 36-celled colony
85—90u wide.
Common in the eu- and tychoplankton of many lakes and swamps;
generally distributed. Mich., Wis.
Pediastrum Boryanum var. longicorne Raciborski 1889, p. 18
Pl. 47, Fig. 10
Peripheral cells with outer margins extended into longer processes
than in the typical plant; apices of lobes swollen; cells 20-35-(40) »
in diameter.
Euplankter. Mich., Wis.
Pediastrum Boryanum var. undulatum Wille 1879, p- 28
Pl. 48, Fig. 2
Similar to the typical plant, but the adjoining cell walls are
undulate and irregular rather than straight; surface walls with
granules or smooth; the lobes of the peripheral cells narrow and
longer than in var. rugulosum, lobes of one cell about the same
distance apart as are the lobes of adjoining cells; cells 17—22 in
diameter.
Euplankter. Mich., Wis.
Pediastrum Braunii Wartmann in Wartmann & Schenk
1862, Fasc. 1, No. 32
Pl. 48, Fig. 5
Colony circular in outline, nearly entire but with a few interstices,
composed of 4-16 quadrate or 5-sided cells (11 peripheral and 5
central); peripheral cells with 3 or 4 short, sharp projections which
are unevenly spaced; interior cells 4-5-sided, the walls without
projections or incisions; cells 9-12, in diameter.
Euplankter. Wis.
Pediastrum duplex Meyen 1829, p:. 772
Pl. 48, Fig. 4
Colony 8-128-celled, the walls smooth, with lens-shaped spaces
between the inner cells, which are quadrate, the outer margin
concave; peripheral cells quadrate, the outer margin extended into
2 tapering, blunt-tipped processes, distance between processes of
one cell about one-half the distance between processes of adjacent
cells; cells 15.6. in diameter; 36-celled colony 105 in diameter.
Common in the eu- and tychoplankton of many lakes and swamps.
Mich., Wis.
Pediastrum duplex var. brachylobum A. Braun 1855, p. 93
A variety in which the peripheral cells bear 2 widely separated,
very short, truncate processes (about 3 long); colony composed
of 16-128 cells, with granular walls; colony up to 300, cells up to
40u, in diameter.
Mich.
Pediastrum duplex var. clathratum (A. Braun) Lagerheim 1882, p. 56
Pl. 48, Fig. 6
Colony with larger perforations than in the typical form; walls
with deep emarginations; apices of lobes of peripheral cells truncate;
cells 12-20 in diameter.
Very common in a large number of lakes of both hard and soft
water; generally distributed. Mich., Wis.
[ 223 ]
Pediastrum duplex var. cohaerens Bohlin 1897, p. 31
Pl. 48, Fig. 11
Colony with large clathrations; cell walls granular; cells 15-20.
in diameter.
Common in tychoplankton. Mich., Wis.
Pediastrum duplex var. gracilimum West & West 1895a, p. 52
Pl. 48, Fig. 12
Colony with large perforations; body of cells narrow, equal in
width to the processes of the peripheral cells, which are relatively
larger than described for the typical plant.
This is undoubtedly a growth form of the typical plant.
Euplankter. Mich., Wis.
Pediastrum duplex var. reticulatum Lagerheim 1882, p. 56
Pl. 49, Fig. 1
Outer margins of the peripheral cells having lobes with subparallel
sides; inner cells nearly H-shaped.
This form, like the preceding one, should be interpreted as a
growth form of P. duplex.
Widely distributed; euplanktonic. Mich., Wis.
Pediastrum duplex var. rotundatum Lucks 1907, p. 31
Pl. 48, Fig. 8
Marginal cells with stout lobes which have convex rather than
parallel margins; apices of lobes closer together than in the typical
plant.
Euplankter; common. Mich., Wis.
Pediastrum duplex var. rugulosum Raciborski 1889, p. 24
Pl. 49, Fig. 3
Colony ovoid, entire except for small lens-shaped openings be-
tween peripheral and inner cells; walls irregularly crenate and
wrinkled, granular; cells 15-22, in diameter.
Euplankter. Wis.
Pediastrum glanduliferum Bennett 1892, p. 7
Pl. 49, Fig. 4
Colony elliptical, entire or nearly so; peripheral cells 5- or 6-angled
with a concave incision between 2 long, capitate projections which
are tipped with a globular swelling; cells about 10, in diameter, 12
long.
Euplankter. Wis.
[ 224 ]
Pediastrum integrum N aegeli 1849, p. 97
PI. 48, Figs. 9, 10
Colony entire; cells 5-sided; outer margin of peripheral cells
smooth or with 2 short and much reduced processes, and granular
walls, emarginate between the processes; cells 16-25u in diameter.
A smooth-walled form of this species, fa. glabra Racib., is fre-
quently encountered.
Euplankter. Mich., Wis.
Pediastrum integrum var. priva Printz 1914, p. 73
Pl. 48, Fig. 7
Colony smaller than the typical plant; peripheral cells trapezoidal,
the outer margins straight or slightly retuse.
Euplankter. Wis.
Pediastrum integrum var. scutum Raciborski 1889, p-5
Pl. 49, Fig. 2
Colony entire, 8—64-celled, walls thick; interior cells 5- or 6-sided;
peripheral cells 5-sided, rhomboidal, the outer wall convex and
without processes, surface of walls and free outer margins furnished
with numerous, sharp granules; cells 10-18.5-(28), in diameter.
Rare, in littoral flora. Mich., Wis.
Pediastrum Kawraiskyi Schmidle 1897, p. 269
Pl.50, Fig. 1
Colony entire; inner cells 4- or 6-sided; peripheral cells napiform
in vertical view, the outer margin extended into 2 projections which
are not in the same plane, one usually directly above the other;
cells 10-20, in diameter.
Eu- and tychoplanktonic; common. Mich., Wis.
Pediastrum muticum Kuetzing 1849, p. 193
Pl. 49, Fig. 8
Colony perforate, with 8-64 smooth-walled cells; inner cells 5-
or 6-sided; peripheral cells with emarginate outer walls and 2
broadly rounded lobes, which are further apart than the lobes of
adjacent cells; cells 20 in diameter.
The original description of this plant contains no justification for
including it with P. tetras as in DeToni, 1889, Sylloge Algarum, 1
(1) p. 581.
Rare, in euplankton. Mich., Wis.
[ 225 ]
Pediastrum muticum var. crenulatum Prescott 1944, p. 356
PI]. 49, Fig. 9
A variety differing from the typical in having crenulate or ir-
regularly wavy walls on both the adjoining and the outer free
surfaces; colony large, as many as 134 cells (in concentric rows of
34, 31, 27, 21, 15, 6); cells 18-24.5y in diameter, colony up to 167p
wide; 340, long.
Rare; in plankton. Wis.
Pediastrum obtusum Lucks 1907 (reprint), p. 13
[Pediastrum quadricornutum Prescott 1944, p. 3561
Pl. 49, Figs. 6, 7
Colony nearly entire, with minute interstices formed by the
retuse margins of some cells; colony oblong, rarely subcircular (the
rows of cells arranged: 7 - 1; 16- 11-5; 16-9-7), composed of from
8-32 cells which have a deep narrow sinus forming 2 major lobes,
the lobes incised to form bluntly rounded lobules, the two central
lobules in contact or nearly so, thus closing the sinus outwardly,
the two lateral lobules in contact with the lateral lobules of the
adjoining cells; interior cells about the same shape as the peripheral
cells but with the lobules less prominent, sometimes wanting, with
the wall merely emarginate or nearly straight; cells 10.5-18, in
diameter; 8-celled colony up to 144» wide.
Euplankter. Wis.
According to Bigeard (1935) such a form as this would be included
with P. tetras, a species which has many variations. Pediastrum
obtusum is here regarded as separable from P. tetras on the basis
of the narrow, closed incisions of the cells and the obtuse apices.
The form was described by Prescott (1944) as P. quadricornutum
because it seemed to be separable from the forms included in
Bigeard’s monograph (1935). It had been described earlier, how-
ever, as P. obtusum by Lucks (1907).
Pediastrum sculptatum G. M. Smith 1916, p. 475
Pl. 49, Fig. 5
Colony entire or with narrow perforations; internal cells 4—6-sided;
peripheral cells with 2 lobes having subparallel margins; cell wall
covered with a fine reticulum of ridges; cells 10-15 in diameter;
colony 150-180, wide.
Euplankter. Wis.
[ 226 ]
Pediastrum simplex (Meyen) Lemmermann 1897, p. 180
Pl. 50, Fig. 2
Colony entire, composed of 16-32-64 smooth-walled cells; inner
cells 5- or 6-sided; peripheral cells with the outer free wall extended
to form a single tapering, horn-like process with concave margins;
cells 12-18y in diameter.
Common in the plankton of a number of lakes. Mich., Wis.
Pediastrum simplex var. duodenarium ( Bailey )
Rabenhorst 1868, p. 72
Pl. 50, Figs. 4, 5
Colony perforate, composed of 36-48-64 cells with their inner
margins concave, the outer margin of inner cells forming a long pro-
cess, peripheral cells forming a stout process; cells 11-15y in dia-
meter, 27-28 long; 36-celled colony 137, in diameter.
Euplankter. Mich., Wis.
Pediastrum tetras (Ehrenb.) Ralfs 1844, p. 469
Pl. 50, Figs. 3, 6
Colony entire; inner cells (frequently none) with 4-6 straight
sides but with one margin deeply incised; peripheral cells crenate,
with a deep incision in the outer free margin, their lateral margins
adjoined along 2 of their length; cells 8-12-(16) in diameter.
Common and generally distributed in both eu- and tychoplankton.
Mich., Wis.
Pediastrum tetras var. obtusata Raciborski 1889, p. 32
Cells larger than in the typical plant, the outer margin of the peri-
pheral cells straight, not so emarginate; cells 14-18, in diameter,
18-22, long.
Euplankter. Wis.
Pediastrum tetras var. tetraodon (Corda) Rabenhorst 1868, p. 78
Pl. 50, Fig.7
Colony 4—8-celled, outer margins of peripheral cells with deep
incisions; the lobes extended into sharp, horn-like processes; cells
12-15, in diameter, 16-18, long.
Euplankter. Mich., Wis.
SORASTRUM Kuetzing 1845, p. 144
A spherical colony of either loosely or compactly arranged reni-
form, pyriform, cuneate or pyramidate cells, attached by radiating
strands to a common polyhedroid central body of mucilage; outer
[ 227 ]
and free surface of the cell furnished with 1-4 stout, outwardly
directed spines; 1 diffuse chloroplast covering most of the wall,
containing a single pyrenoid.
Key to the Species
Cells broadly cuneate; spines 4—8u long —__._.._--_--_----- S. spinulosum
Cells narrowly cuneate; spines 10—15u long. S. americanum
Sorastrum americanum (Bohlin) Schmidle 1900d, p. 230
Pl. 50, Fig. 8
A free-floating spherical colony of 16-128 heart-shaped or sub-
pyramidate cells with the outer free walls emarginate and furnished
at each of the 4 angles with a long, stout, outwardly directed spine;
cells narrowed toward the base and attached to the center of the
colony by a short, cylindrical stalk which at the base is 5- or 6-sided
adjoining the sides of other stalks in such a way as to form a central
hollow sphere; cells 7-20» in diameter, 5-20 long, 4-8 thick;
spines 10-15». long.
Rare; in several soft water lakes, especially in northern counties;
eu- and tychoplanktonic. Mich., Wis.
Sorastrum americanum var. undulatum G. M. Smith 1918, p. 640
Pl. 50, Fig. 10
A variety differing from the typical in having the margins of the
facets at the base of the stipe undulate.
Rare; in the euplankton of lakes. Wis.
Sorastrum spinulosum Naegeli 1849, p. 99
PI. 50, Fig.9; Pl. 53, Fig.1
A spherical, free-floating colony of 4-32 rhomboidal, reniform, or
broadly cuneate cells attached by a very short and broad stipe to
a common center; outer free wall straight, furnished at each angle
with 2 relatively short spines, 4-8 long; cells 8-20, in diameter,
6-18, long, 5—8p thick..
Common in the plankton of many lakes; generally distributed.
Mich., Wis. .
FAMILY COELASTRACEAE
This small family is characterized by cells that are radiately
arranged and adjoined, forming globular colonies which may be
either hollow or solid. In most species the cells are interconnected
by narrow processes or by extensions of the cell membrane to form
interstices. The chloroplast is parietal, covering nearly the entire
wall. Reproduction is by formation of a definite number of auto-
[ 228 ]
spores within each cell of the colony. These become adjoined to
form daughter colonies before being liberated. There is but one
genus, Coelastrum, since “Phytomorula”? has been found not to be
an alga.
COELASTRUM Naegeli in Kuetzing 1849, p. 195
A hollow, spherical, free-floating colony of as many as 128 globose,
ovoid, or pyramidal cells which either are closely adjoined and
compressed, or interconnected by narrow processes to form a
fenestration. Daughter colonies are formed within the parent cells;
the walls of the parent cells may persist about the new colonies,
interconnecting them and so forming complexes.
Key to the Species
1. Cells without arms; interconnecting processes extremely
short, sometimes: scarcely ‘evident! 2
1. Cells with arms, or with longer and very
evident IntercOMNE CHINE MTOCESSES = 95 = oh 4
2.) Cell walls with-wart-like processes. = C. scabrum
2. Cell: walls’ without ‘wart-like processes =) ==). 3
8. Cells spherical or ellipsoidal, closely adjoined, with interstices
narrower than the diameter of the cells_......___-__»_»_»_»»__ C. microporum
3. Cells conical, adjoined, but with interstices as wide as the
Gdiameter of the cells, or wider... es C. sphaericum
4. Cells pyramidal or conical; arms truncate, adjoined within the colony in
such a way as to form large fenestrations... C. proboscideum
Are G@ellsesplericnll» 8.7 k ait. EE an Se ot tate Dn Ee 5
5. Cells at the ends of long gelatinous strands
fainting irom asconmion. center. (te 122 2 sie Se Se ed C. speciosum
o. Gells\not at the. ends of long radiating strands 6
6. Outer free walls of the cells with a truncate projection;
interconnecting processes of cells short._.._-.....--------------------- C. cambricum
6. Outer free walls of cells without a projection;
mterconmecting processes long. 2 st C. reticulatum
Coelastrum cambricum Archer 1868, p. 65
Pl. 58, Fig. 2
Coenobium spherical, usually composed of 32 globose cells (rang-
ing from 8 to 128 in number), each cell adjoined to neighboring
cells by 6 broad, short projections of the sheath so that triangular
intercellular spaces result; outer free wall of the cells with a
flattened, truncate projection; cells 10-20. in diameter, including
sheath.
Widely distributed and common in the plankton of a great variety
of lakes and bogs. Mich., Wis.
3Phytomorula regularis Kofoid, the only species described, has been shown to be pollen of
Acacia spp. (H. F. Copeland in Madrofio, 4, pp. 120-125. 1937); hence the family Coelas-
traceae is monogeneric, unless Chodat’s genus Coelastrella should prove to be well founded.
[ 229 }
Coelastrum microporum Naegeli in A. Braun 1855, p. 70
PI. 53, Fig. 3
Coenobium spherical, composed of 8-64 sheathed globose cells
(sometimes ovoid, with the narrow end outwardly directed); cells
mterconnected by very short, scarcely discernible gelatinous proc-
esses, leaving small intercellular spaces; cells 8-20. in diameter
including the sheath.
Common in the tychoplankton of many lakes and ponds. Mich.,
Wis.
Coelastrum proboscideum Bohlin 1897, p. 33
[C. compositum G. S. West]
Pl. 53, Figs. 4, 5, 8
Coenobium pyramidal or cubical (rarely polygonal), composed
of 48-16-32 truncate cone-shaped cells with the apex of the cone
directed outward, the inner or basal wall of the cell concave, the
lower lateral walls of the cells adjoined about a large space in the
center of the colony; cells 8-15, in diameter; 4-celled colony as much
as 35p in diameter.
In both tycho- and euplankton of several lakes; not as common as
other species of Coelastrum. Mich., Wis.
Coelastrum reticulatum ( Dang.) Senn 1899, p. 66
Pl. 53, Fig. 6
Coenobium spherical, free-floating, composed of 8-32 globose cells
each inclosed by a gelatinous sheath and adjoined to neighboring
cells by 6 long, slender gelatinous processes, leaving large intercell-
ular spaces; outer free wall of the cells without protuberances or
processes; cells 8—20-(24) » in diameter including the sheath.
Euplankter. Mich., Wis.
Coelastrum scabrum Reinsch 1878, p. 238
Pl. 46, Fig. 3
Coenobium spherical, composed of 8-16 angular-globose to
angular-depressed-globose cells which bear on their outer faces 4-6
short, wart-like and truncate projections; cells 8-10 in diameter.
Mackinaw City, Michigan.
Coelastrum speciosum (Wolle) Brunnthaler 1915, p. 197
Coenobium spherical, composed of 16-24 spherical cells, each at
the end of a slender gelatinous strand radiating from the center of
the colony; outer face of the cell with a single, short-truncate gel-
atinous projection; cells 10-12» in diameter.
Cheboygan County, Michigan.
[ 230 ]
Coelastrum sphaericum Naegeli 1849, p. 98
Pl. 53, Fig. 7
Coenobium ovoid, composed of conical cells, the narrow end
directed outward, adjoined without processes along the lower lateral
walls, forming interstices which are equal to or greater than the
diameter of the cells; cells up to 25, in diameter.
Euplankter. Mich., Wis.
FAMILY BOTRYOCOCCACEAE
This family is composed of plants which have ovoid or spherical
cells embedded and crowded in tough, often foamy, irregularly
shaped masses of mucilage which are frequently darkly colored and
semi-opaque. In some species the cells are inclosed in a cup of fatty
substance with an outer layer of pectic material. The chloroplast is
an open or close parietal net-work, usually with 1 pyrenoid. Both
starch and oil accumulate as food reserve, the latter often so dense
as to obscure the true nature of the cell content. Asexual reproduc-
tion is carried on by autospores.
As here defined, this family includes only the genus Botryococcus
which has been given various taxonomic positions. Because the fatty
material] in which the cells are embedded is so darkly colored in the
type species, B. Braunii Kuetz., the exact nature of the cell content
and pigmentation has been difficult to determine. Until recently the
genus has been placed in the Heterokontae (Chrysophyta) with a
few other genera, to comprise the family Botryococcaceae. The
critical studies of Blackburn (1936) on Botryococcus Braunii Kuetz.,
however, seem to establish the identity of this species as a member of
the Chlorophyta. The morphology of the wall, the presence of
a pyrenoid and of starch, and the habit of retaining mother cell
membranes and secretions in the building of the colony justify the
removal of the genus from the Chrysophyta. Blackburn (l.c.) rightly
proposes that the Botryococcaceae be placed near the Dictyo-
sphaeraceae. See page 237.
BOTRYOCOCCUS Kuetzing 1849, p. 892
[Ineffigiatus West & West]
Thallus an irregularly globose or bullate colony of ovoid or
spherical cells densely arranged somewhat radially in a sticky, often
dark-colored mucilage, the cells embedded in a cup-like sheath of
fatty material in one species; compound or net-like aggregates of
colonies may be formed by long or short strands of rubbery mucilage
connecting several clusters of cells; chloroplast a fine or close
[ 231 ]
net-work covering only part of the wall, containing 1 pyrenoid;
both starch and oil present as food reserves; reproduction by frag-
mentation and by autospores.
Key to the Species
1. Cells inclosed by a tough, rubbery, often darkly colored mucilage ._-______. 2
1. Cells invested by a thin, colorless mucilage == B. sudeticus
2. Colonial envelope completely covering the cells; mucilage darkly
colored, especially in the older colonies... B. Braunii
2. Colonial envelope leaving the outer face of the cells free B. protuberans
Botryococcus Braunii Kuetzing 1849, p. 892
Plo, wigsa le. Ut
Cells ellipsoid, radiately arranged at the periphery of irregularly
shaped, usually dark-colored masses of mucilage; free floating;
colonial mucilage much folded and extended into tough, foamy
strands, often forming colonial complexes by interconnecting strands
of mucilage; chloroplast a thin, or dense, parietal net with 1 pyrenoid,
covering only a portion of the wall (often masked by the dark
color of the mucilage); starch and oil droplets present; individual
cells invested by a layer of fatty substance and an outer layer of
pectin; cells 3-6 in diameter, 6-12, long.
Common, and often abundant, especially in semi-hard water
lakes where it frequently is the dominant component of water-bloom
associations.
Mich., Wis.
Botryococcus protuberans var. minor G. M. Smith 1918, p. 652
Pl. 52, Figs. 4,5
Cells ovoid, arranged in few-celled clusters which are connected
by long tough, fibrous strands, 4-16 such clusters involved to form
multiple colonies; cells embedded in but not entirely surrounded
by mucilage, one end protruding at the periphery; cells 5-6.5 in
diameter, 8—9.5, long.
Rare to common in the euplankton of several lakes, Mich., Wis.
Botryococcus sudeticus Lemmermann 1896a, p. 111
Pl. 52, Fig. 3
Cells spherical, clustered and embedded in a hyaline mucilaginous
envelope, forming irregularly shaped or somewhat spherical masses
which may be joined together by gelatinous strands to form com-
plexes; cells 6-13, in diameter.
Rare in the euplankton of several lakes. Mich., Wis.
[ 232 ]
FAMILY OOCYSTACEAE
This is a large family in which there is a wide range in cell shape
and arrangement. The cells may be spherical, ovate, pyramidal, or
polygonal. Some forms are unicellular, others colonial. The chief
characteristic which unites the 30 or more genera is the autospore
method of reproduction; ordinary cell division and zoospore for-
mation are not known. The autospores are small replicas of the
mother cell and are usually cut out in a definite number from the
parent protoplast. Upon escape they may remain together to form
a colony, as in the Coelastraceae, or may separate. Unlike the
Coelastraceae and the Scenedesmaceae, however, the colonies are
not composed of definitely arranged cells. In most cases the cells
are not adjoined but are held together by a gelatinous investment
or by the enlarged and persistent mother cell wall, or gelatinized
portions of the old wall. In the majority of forms there is a single,
laminate chloroplast, but a few species have several to many disc-
like bodies, each with a pyrenoid. Multinucleate cells are rare.
Key to the Genera
1. Plants endozoic in the cell or body cavities of animals
RS OME CS UTR: TELCO) ian ahs ce tte! Seen wn Se ee ee Zoochlorella
Tarts mots CUE OAOTC se. wre aed LN ee A oe eee Se 2
Opel lear tssesuiray ce ll eit sa 92 a Fa en eg ne a 3
ems ATUESHS COOMA Noe Wee eke eee BI Re le Ly epee 21
8. Cells angular, pyramidal, triangular, or polygonal ____________________ 4
3:, Gells: spherical, ellipsoid, ovoid; or acicular— 8
Ae angies bearings spines ‘Or bristles. ee 6
4, Angles not bearing spines; smooth or with the angles produced
and extended to form simple or branched processes___...._._------_----------------- 5
5. Cell body evident, distinguishable from the extensions of the
angles, or with angles smooth and rounded. Tetraédron (part)
5. Cell body not clearly evident, gradually extended into the
processes of the sanglesz 2 S30. et Cerasterias ( part )
6. Body of the cell evident, with or without
POC eG eet le seeteemetien eres eats eR ee 32
6. Body of the cell not clearly evident, gradually extended into the processes . 7
7. Angles of the cell with a thick, stout, and very long spine Treubaria
7. Angles of the cells gradually narrowed to form a spine-like tip,
or with the apices tipped with minute spines___________ Cerasterias (part)
Gas Cells splierice late ene eet ere eee eee ee eee Se ee 9
SeCellssovate:. ellipsoids lunate, “or GicicMlar =)... scan fescacesnoeeteeeadnedeeoneene 14
9. Cell wall ric LGROMUROMDME Ns ou ay a re) 10
SeGeulwallenot asin Ot eee weer eae ant aoe ties ee ee eae Hts}
10. Cells with 1 chloroplast (see also Zoochlorella) Chlorella
10 Cells; with several tosmany chloroplasts 4° 5 Te
11. Cells inclosed by a wide gelatinous investment; chloroplasts not
» in a reticulum nor in radiating strands. Planktosphaeria (part)
11. Cells not inclosed by a gelatinous investment —_________._______-_-_------- 12
[ 233 ]
12. Chloroplasts numerous irregular plates arranged in a reticulum
or in strands of cytoplasm radiating from the center of the cell;
pi ofall Wo of 5 « Mane aan UL Ee eek OI AN BAC Zs Ney Dee LI oe A Eremosphaera
12. Chloroplasts cone-shaped, arranged at the periphery and
projecting inward; wall thick and lamellate_________ Excentrosphaera
13. Cell wall with reticular markings or with short spines _.. Trochiscia
13. Cell wall with several long, sometimes stout, spines Echinosphaerella
Tas @ells ellipsoid oan Ee ee ee eee 15
14, Cells lunate, straight and fusiform, or acicular____-__________________ 17
Tb>aGells: without spinesor setae. Oocystis ( part )
15.) \Cells\ bearing spines) Or/setae 2-2 id ae 16
16. Setae distributed over the entire cell wall —_______-__------------------- Franceia
16. Setae arising from the poles only, or from the poles
and the equator ei BAe 2k 2 Re ee Ee ee Lagerheimia
Lie Gellsilunate distinctly jemrved See ts et Ea Yee ee eee 18
L7aeellststraignt, acieular,iorjfusitorm sme uale2 TE eee eee 19
18. Cells invested by a gelatinous sheath________________-_-- Kirchneriella (part)
1$2' Cells notjinclosedbyya) sheath 4 ee Ankistrodesmus ( part )
19. With a fine, needle-like spine at one or both poles of the cell Schroederia
19. Poles of the cell without a spine, although apices may taper
toy aslinte pointasiee fs oe hei ate ee ee eee 20
20. Chloroplast an elongate plate with a row of pyrenoids;
cell up to 5304 long reece aa ect Bs MOURNE ee Meron er eds Closteriopsis
20. Chloroplast without pyrenoids, or with but 1;
cell’ much shorter than above... Ankistrodesmus ( part )
Die Cellsiwithia celatmousiinvestment = = se eee 22
2ieiGellsiwithoutkagelatinousinvestment =" eae se 26
22 Cellsisphenicaly or broad lyiovatetiene es ee wee 23
22. Cells not spherical, but elongate, at least twice as long as wide —...__ 24
23. Cells arranged in clusters at the ends of radiating strands _Dictyosphacrium
23. Cells not adjoined by radiating strands Planktosphaeria ( part )
24. Cells straight, with long axes parallel in the colony___-- Quadrigula
AM Ge SS Currey CC eee ae re ee Oe ee ee 25
25. Cells invested by a firm sheath (gelatinized mother cell wall);
cells’ slightly, curved: or remiform 2. -.o..cecccsee oapcese cote peers Nephrocytium
25. Cells in a homogeneous, thin mucilage; sharply
curved, lunate or sickle-shaped.......................:-:0-00- Kirchneriella (part)
26. Cells adjoined by remains of old mother cell walls
at-the center of the: colomy:..0 72 Ues J. 1.26 2) ee ee oT
26. Cells held together by other means; fragments of old mother cell
wallsinot presentat centerol colony. = ee 28
27. Cells spherical; cell wall fragments curved and unbranched... Westella
27. Cells reniform or ovoid; cell wall fragments forming
straight branching) strands. ee Dimorphococcus
28. Cells spindle-shaped; adjoined end to end to form
ALChain which miay Drala cli: sass ine Loewe eee eee Dactylococcus
28. Cells not spindle-shaped and not adjoined end to end
dint alcchrain® like wS ee GS ie oes nie a eI Ce 29
29. Cells ovate or spherical, inclosed by enlarged mother cell walls___________-- 80
29. Cells elongate, acicular, or spindle-shaped__________-__-------------------------------— 31
30. Cells separated from one another by a deposit of semi-opaque
mucilage which forms cruciately arranged bands
about, thie ;Colonyst.5 odode, Sen ee ee ee eee Gloeotaenium
30. Cells not separated by semi-opaque deposits of mucilage_. Oocystis (part)
31. Cells lunate or sickle-shaped, with their convex
SUEEACES AP DOSeCi. ees oc ene et Sl oo! Selenastrum
31. Cells straight, in fascicles or irregular clusters, sometimes
twistedabout one. another t=. “Ue Ne eee Ankistrodesmus (part)
32. Angles tipped with 4-6 fine, hair-like bristles 3 Polyedriopsis
32. Angles tipped with 1, 2, or 3 short, stout spines ___ Tetraédron (part)
ZOOCHLORELLA Brandt 1882, p. 140
Unicellular; spherical or ovoid; inhabiting the cells and body cav-
ities of animals. Chloroplast (sometimes 2) a parietal plate covering
only a portion of the wall; pyrenoid usually present. Reproduction
by aplanospores, as in Chlorella.
This group, with justification, is regarded by some students as
being congeneric with Chlorella. It is arbitrarily separated here and
the name retained in order to provide a distinct category for the
endozoic species. The phenomenon of ‘green’ animals, such as Hydra,
Ophrydium, Spongilla, etc., is invariably referred to as being caused
by Zoochlorella. Long usage, therefore, seems to warrant the sepa-
ration. The relationship between species of this group and various
animals is apparently definite and not haphazard. The symbiosis may
vary from commensalism to parasitism. Although the species are
described as having no pyrenoid, our specimens usually showed
this body very clearly, especially in larger cells.
Key to the Species
Plants inhabiting Hydra; cells 3-6u in diameter Z. conductrix
Plants inhabiting Ophrydium, Spongilla, and Stentor;
@ellsnltn—s ein Ciaimeter ee oe te Pai ee! Z. parasitica
Zoochlorella conductrix Brandt 1882, p. 140
Pl. 53, Fig. 10
Cells globose or broadly ovoid, usually densely compacted with
the cells of Hydra; chloroplasts 1-2, usually with a pyrenoid; cells
3-6, in diameter.
Common; in green Hydra; inhabiting ponds and swamps where
there are dense beds of aquatic vegetation. Mich., Wis.
Zoochlorella parasitica Brandt 1882, p. 140
Pl. 53, Fig. 9
Cells ovoid, inhabiting Ophrydium, fresh-water sponges (Spong-
illa), and Stentor spp.; chloroplast 1 (rarely 2); cells 1.5-3» in
diameter.
Common in Ophrydium, a colonial ciliate which forms floating
or attached gelatinous masses 1-10 cm. in diameter. Sometimes the
[ 235 ]
colonials are attached to submerged vegetation. The algal cells vary
in abundance so that the colony may be light or very dark accord-
ingly. The protozoan inhabits mostly hard water lakes where it is
frequently mistaken for Nostoc, Tetraspora, or some other gelatinous
alga. Mich., Wis.
CHLORELLA Beyerinck 1890, p. 758
Unicellular, solitary or aggregated in irregular clumps; round or
ellipsoid; variable in size in the same habitat. Chloroplast a parietal
cup or merely a plate, with or without a pyrenoid. Reproduction by
4 or 8 daughter cells (non-motile) produced from the protoplast
of the mother cell.
This small plant may be confused with species of Chlorococcum,
a soil or subaerial genus, from which it can be differentiated with
surety by a study of reproductive habits. It is very similar also to
many other unicellular green algae and may be confused with
motionless ZOOspores of some genera. It is necessary, therefore, to
study a large number of individuals, or better still to culture the
plants in making identification.
Chlorella forms 4 or 8 daughter cells within the mother cell wall
whereas Chlorococcum produces biflagellate zoospores which escape
and immediately separate from one another. In Chlorococcum the
chloroplast more nearly covers the cell wall than in Chlorella.
Chlorococcum lives almost entirely on or in soil, sometimes at con-
siderable depth, or on old wood and rocks. Chlorella is aquatic but
may share the same habitat with Chlorococcum.
Beyerinck (1890) recommends combining Chlorella and Zoo-
chlorella, but for the reason mentioned above (under Zoochlorella ),
they are separated here.
Key to the Species
Cells ellipsoidal, 7-8 in diameter, 9.5 long: Mesias C. ellipsoidea
Cells spherical, usually 5-10 in GaaMeter eet tS es ee C. vulgaris
Chlorella ellipsoidea Gerneck 1907, p. 250
Pl. 58, Figs. 11, 12
Cells ellipsoidal, sometimes unsymmetrical; chloroplast a folded
plate over part of the cell wall; described as producing as many as
32 autospores during reproduction; vegetative cells 7-8, in diameter,
9-9.5p long.
Generally distributed in many lakes and ponds. Mich., Wis.
[ 236 ]
Chlorella vulgaris Beyerinck 1890, p. 758
PI. 53, Fig. 13
Cells spherical, scattered among other algae or sometimes occur-
ring in almost pure growths; chloroplast a parietal cup, sometimes
without a pyrenoid; cells 5-8.5-(10) in diameter.
In small lakes and pools, especially where there is a concentration
of organic matter. Mich., Wis
WESTELLA de Wildemann 1897, p. 532
A free-floating, globose colony of 30-100 spherical cells without
a gelatinous investment; members in groups of 4 and bound together
by the persistent remains of old mother cell walls; 1 parietal, cup-
shaped chloroplast, often with a pyrenoid.
Key to the Species
Colonies of 40 cells or fewer; cells arranged in
linearseries;)6=G.in diameter: 2b he W. linearis
Colonies of 40-80 cells; cells arranged to form
quadrate Or pyramidate clusters 2 8 W. botryoides
Westella botryoides (W. West) de Wildemann 1897, p. 532
PI. 58, Fig. 14
Colony composed of 40-80 spherical cells, quadrately arranged
in groups of 4, the groups loosely connected by the persistent
remains of old mother cell walls; cells with 1 parietal, cup-shaped
chloroplast; pyrenoid sometimes present; cells 3-9, in diameter.
Rare but widely distributed, in a large number of lakes, especially
in the plankton of soft water. Mich., Wis.
Westella botryoides var. major G. M. Smith 1918, p. 628
A variety differing from the typical by having larger cells, 8-13p
in diameter.
Rare in euplankton. Mich., Wis.
Westella linearis G. M. Smith 1920, p: 107
Pl. 53, Figs. 15, 16
An irregularly shaped colony of about 40 spherical cells arranged
in a linear series of 4; groups of cells held together by inconspicuous
remains of old mother cell wall fragments; cells 3-6. in diameter.
Rare in euplankton. Wis.
DICTYOSPHAERIUM Naegeli 1849, p. 72
Colony globular or ovoid, composed of spherical or ovoid cells
attached by fine, branching strands which radiate from a common
[ 237 ]
center, the entire colony invested by a wide, hyaline, gelatinous
envelope; cells with 1 or 2 parietal chloroplasts, each with a pyrenoid.
Key to the Species
Cells ellipsoidal or ovoid; colony ovoid D. Ehrenbergianum
Cellsispherical; colony usually globose! = ee D. pulchellum
Dictyosphaerium Ehrenbergianum Naegeli 1849, p.73
Pl. 51, Figs. 3, 4
Colony ovoid, composed of 8-30 ellipsoidal cells with 1 or 2
parietal or cup-like chloroplasts, cells attached in groups of 2 or 4
at the ends of fine, branched strands; cells 4-6y in diameter, 8-10
long.
Goenee in the plankton of many soft water lakes. Mich., Wis.
Dictyosphaerium pulchellum Wood 1874, p. 84
PI. 51, Figs. 5-7
Colony spherical or ovoid, composed of as many as 32 spherical
cells arranged in series of 4 on dichotomously branched threads,
inclosed in mucilage; cells 3-10 in diameter.
This species is sometimes a conspicuous component of the
plankton in acid bog lakes. Taylor (1935) has found it in the leaves
of pitcher plants (Sarracenia purpurea L. )
Generally distributed in many soft water as well as semi-hard
water lakes. Mich., Wis.
TROCHISCIA Kuetzing 1833b, p. 592
Free-floating (or sometimes subaerial), spherical, unicellular
plants with thick walls which are either smooth or variously
sculptured and decorated (reticulations, warts, spines); with 1 to
several plate-like, parietal chloroplasts; pyrenoids 1 or more.
Some care must be used in distinguishing members of this genus
from the zygospores of some desmids. The latter have a single,
massive chlorophyll-bearing body of indefinite form.
Key to the Species
1. Wall decorated with granular, wart-like or spine-like roughenings — 2
1. Wall decorated with ridges which may be concentric
and: parallel; or may, form ‘a xeticulun=— 8 6 eee 8
2. Granulations sharply pointed and numerous.._..-...--------------------- T. aspera
2. Granulations low and blunt, not so closely
AETAN SEC 525) 5 AON Cet ea te oe an ae aT der T. granulata
3. Wall with concentric ridges which form
low,bhunt: protuberances: 050 00 iio hawk Ee eee T. obtusa
Suk Wall’ with reticulate ric ges: 5 be 5 8 ee eee 4
4. Reticulations coarse, forming ‘8-10 visible polygonal areas ____ T. Zachariasii
4. Reticulations fine, forming as many as 35
visible areas vonsthes wall. se dite) ais Ca onc) Bee, oa ae T. reticularis
[ 238 ]
Trochiscia aspera (Reinsch) Hansgirg 1888a, p. 128
PI. 53, Fig. 17
Cells free-floating, globose, the wall moderately thick, decorated
with evenly distributed, wart-like projections (interconnected by
faint lines P), chloroplasts several, disc-shaped; cells (13 )-18-29.5u
in diameter.
Rare in plankton. Mich., Wis.
Trochiscia granulata (Reinsch) Hansgirg 1888a, p. 128
Pl. 53, Fig. 18
Cells aquatic or subaerial, spherical, the wall thick and densely
covered with low, granular or wart-like roughenings; cells 10-20-
(23) in diameter.
In a Sphagnum bog. Mich., Wis.
Trochiscia obtusa (Reinsch) Hansgirg 1888a, p. 130
PI. 52, Fig. 8
Cells spherical, the wall thick, with concentric series of ridges
or low, parallel protuberances; 34-37, in diameter.
Tychoplankter. Mich., Wis.
Trochiscia reticularis (Reinsch) Hansgirg 1888a, p. 129
PI. 53, Figs. 19, 20
Cells free-floating, spherical, with thick walls which are externally
ridged to form a reticulum in which as many as 70 polygonal areas
may be marked out; cells up to 39, in diameter.
This plant also passes under the name of T. sporoides (Reinsch)
Hansgirg.
Rare; in several lakes and Sphagnum bogs. Mich., Wis.
Trochiscia Zachariasii Lesamermann 1903, p. 157
PI. 58, Fig. 21
Cells free-floating, spherical; wall very thick and decorated ex-
ternally with a very coarse reticulum of prominent ridges marking
out 8-10 irregularly shaped, polygonal areas on the visible side of
the cell, forming prominent projections at the periphery; cells 10-20.
in diameter.
Rare, in plankton. Wis.
PLANKTOSPHAERIA G. M. Smith 1918, p. 627
A free-floating colony of spherical cells compactly grouped within
a mucilaginous, homogeneous envelope; chloroplasts several, angu-
lar, parietal discs, each with a pyrenoid.
[ 239 ]
Planktosphaeria gelatinosa G. M. Smith 1918, p. 627
Pl. 53, Fig. 23
Characteristics as described for the genus; cells (4.5)—20-25, in
diameter.
This plant should be compared with Sphaerocystis Schroeteri,
which has a single parietal, cup-shaped chloroplast and in which
the cells are usually more distantly arranged. In old colonies of
Planktosphaeria gelatinosa the cells may become somewhat loosely
arranged, but usually they are closely clustered.
Common in the plankton of a variety of lakes and ponds, both in
hard and soft water. Mich., Wis.
EREMOSPHAERA DeBary 1858, p. 56
Cells spherical, spheroidal, or somewhat angular-spheroidal (3-
angled in face view); solitary or 2-4 together within an old mother
cell wall, with or without a gelatinous sheath; free-floating or lying
among mixtures of algae in shallow water; chloroplasts numerous,
ovate or irregularly shaped discs or pads, with large starch grains,
lying in a meshwork along the periphery or in radiating strands of
cytoplasm from a central core which involves the nucleus. The
chloroplasts are able to shift their position in response to light
stimulus.
Key to the Species
Cells spheroidal or angular-spheroidal, 2-4 within an old mother
cell wall, inclosed by a gelatinous sheath —_____-_______- E. oocystoides
Cells spherical, solitary, sheaths not apparent.___________________-__ E. viridis
Eremosphaera oocystoides Prescott in Prescott,
Silva & Wade 1949, p. 85
Pl. 46, Fig. 12
Cells spheroidal or triangular-spheroidal in one view, 2-4 (rarely
solitary) within old mother cell walls which are ovate or oblate-
spheroidal, inclosed in a wide gelatinous sheath in which there are
numerous radiating spicules, the old mother cell wall often appear-
ing spiny, and showing flattened, thickened poles; chloroplasts
numerous, small irregularly shaped plates, lumpy with starch grains;
cells up to 122» in diameter; colony 300-450» in diameter.
In shallow water of an acid swamp. Mich.
Eremosphaera viridis DeBary 1858, p. 56
Pl. 53, Fig. 22
Cells solitary, spherical, not inclosed by a mucilaginous sheath;
chloroplasts as described for the genus; cells 50-350, in diameter.
[ 240 ]
This plant is so definitely restricted to soft water habitats that it
may be used as an index organism for acid conditions in which the
pH is 6.0-6.8. It is a common component of a flora in which desmids
predominate, and there is some evidence that high organic acid
content of the water results in huge Eremosphaera cells.
Common in many acid lakes and Sphagnum bog ponds. Mich.,
Wis.
EXCENTROSPHAERA Moore 1901, p. 322
Cells spherical or ellipsoid, free-floating, intermingled with other
algae, the wall thick and often lamellate; chloroplasts numerous
cone-shaped bodies arranged at the periphery and directed inward,
each with many small pyrenoids; reproduction by aplanospores.
Excentrosphaera viridis Moore 1901, p. 322
Pl. 46, Figs. 15, 16
Characteristics as described for the genus; cells 22-55, in diam-
eter; spores (not observed in our collections) 2-3, in diameter.
Tychoplankter; in shallow water of lake margins and soft water
or acid swamps. Mich.
ECHINOSPHAERELLA G. M. Smith 1920, p. 128
Free-floating, globose cells, entirely covered with long, stout,
tapering spines; chloroplast 1, cup-shaped and parietal, containing
a single pyrenoid. The genus is monotypic.
Echinosphaerella limnetica G. M. Smith 1920, p. 128
Pl.51, Figs. 1, 2
Characteristics as described for the genus; cells 9-12, in diameter
exclusive of spines; spines 2.5-31 wide at the base, 20-25, long.
This species should be compared with desmid zygospores, many
of which have spiny walls and greatly resemble Echinosphacrella.
Differentiation can be made on the basis of the chloroplast, there
being no definitely shaped chlorophyll-bearing body in the desmid
zygospore, but a dense, rather shapeless mass.
Rare, in plankton. Wis.
TREUBARIA Bernard 1908, p. 169
Free-floating, pyramidal or flattened 3- to 4-angled unicells, the
angles rounded or produced to form a stout, thick-based spine
which is either tapering or has subparallel sides; the margins of
the cell concave between the angles; chloroplasts 1-4, parietal,
[ 241 ]
cup-shaped in some, becoming massive and filling the cell; 1 or
more pyrenoids, usually 1 in each angle of the cell.
This genus should be compared with the pyramidal species of
Tetraédron, in which the angles of the cell are sometimes drawn
out to form arms. Some species of Tetraédon have the angles bearing
spines, but these are relatively short, never equaling the diameter
of the cell, whereas in Treubaria the angles of the cell are spines,
which are much longer than the diameter of the cell body.
Treubaria setigerum (Archer) G. M. Smith 1933, p. 499
[Tetraédron trigonum var. setigerum ( Arch.) Lemmermann]
Pl. 51, Fig. 8
Cells triangular and flattened in surface view, the angles broadly
rounded and then produced to form a long tapering spine; chloro-
plast a parietal plate, covering the cell wall; cells 7-9, in diameter;
spines 12-15, long.
Rare; in tychoplankton. Wis.
OOCYSTIS Naegeli in A. Braun 1855, p. 94
Unicellular or in colonies of 2-16 individuals inclosed by the
persistent and much swollen mother cell wall of the previous
generation; several successive generations of cells sometimes in-
closed within old membranes; cells ovoid, ovoid-ellipsoid, or rarely
subcylindric, with rounded poles which may be smooth or furnished
with a conspicuous nodule-like thickening; chloroplasts 1 or many,
mostly parietal, of various shapes, ovoid discs, irregular star-shaped
plates, or reticular; 1 pyrenoid in each chloroplast (sometimes
wanting ).
Key to the Species
il Poles) vot) cells) wathe nodular. thickening) ce. cee ese ceseed reer eee 2
1. Poles of cells without nodular thickening; apices rounded or pointed... 9
2. Cells with one pole thickened, the other broadly rounded;
cellsvisomew hate, pyri Orit ele ica. ttle Weel entoaeec snes ae O. pyriformis
2. Cells with nodular thickenings at both poles;
Celismovals vellipHe Or gOOlom ee! write ee eet ate: toe erhe neaeaeen deer erase ea 3
3. Chloroplasts mumerous, 4—25—60 ooo... cece eeeent etre ttteteeen rere eres 4
3. Chloroplasts fewer in number, 1—3 (rarely 4) .........0:ccce ii
4. Cells oblong, with lateral walls concave;
chloroplasts) M2 Dose. 4it s meedeont dy et aeetusteneett ieee zeceto scien O. panduriformis
4. Cells elliptic or oval (sometimes nearly round)...........0.0.:c::cc 5
5. Chloroplasts 40—60 irregularly lobed, parietal discs ...... O. Eremosphaeria
5. Chloroplasts fewer, disciform or oval, laminate ................... ce 6
6. Chloroplasts relatively large, 4-10; mother cell wall
much swollen and inclosing 2—4—(8) daughter cells.................... O. crassa
6
. Cloroplasts smaller and more numerous, 12—25;
mother cell wall not swollen; cells mostly solitary ae
(uncommonly as many as 8 in’/a famiy).........00...0......c: O. solitaria
[ 242 ]
7. Polar nodules conspicuously projecting
inward) 40m.) the cell, wall poh eee ee es a eel a ........O. nodulosa
7. Polar nodules projecting outward (sometimes
with) ‘a ‘slight inner swelling also) 00 ..2205...0. 4 He RR OEE aes
8. Cells elongate-elliptic to nearly cylindrical, 2—3 times their
diameter in length, with subparallel margins .........................O. submarina
8. Cells ellipsoid or ovate, 11/2 times their diameter in length O. lacustris
9. Chloroplasts 1—3—(4) laminate dises or~plates .........0....0..cceeee LO
9. Chloroplasts 4—20—(30) parietal discs or plates
which are oval or star-shaped Ly Pee UPTON 1 oN Aw OCR eee A
10. Cells narrowly elliptic, with sharply rounded to apiculate
poles: 1 laminate chloroplast). 2.22..40.5.-0.-5... .... O. gloeocystiformis
10. Cells oval or more broadly elliptic, with rounded or bluntly
pointed (not apiculate) poles; chloroplasts 1—3—(4).....00.00.0. ial
11. Cells narrowly elliptic, with pointed poles .....0.....00...0.cccceeee O. parva
11. Cells broadly elliptic or oval, with rounded poles.........................:::000 12
12. Cell walls relatively thick; poles very slightly pointed in
some individuals; cells often egg-shaped............................ O. novae-semliae
12 nCellwalls thin: polessmoumdeds.0) 04 oh ahs.g ie sheos etapa tnon a aeed ote 13
13Gells small: °3:8—7.5u in diameter, 6—12,, long... 522.04. mx. O. pusilla
13. Cells larger, 9—13u in diameter, 9—19, long................00......... ..O. Borgei
4: (Chloroplasts 46" star-shaped! "plates yc)... cc mee ctestseeecoeeoeetes O. natans
14. Chloroplasts (4)—10—20 parietal discs or small plates.............0..0..00..... 15
15. Cells 29—40u in diameter; chloroplasts numerous;
old mother cell wall symmetrically inflated ..........0...000000.00.. ee O. gigas
15. Cells 11—15.6u in diameter; chloroplasts 10—20; old
mother celliwalliirrectlarly inflated): 2.0 -1.r.1)..2.0cie0.- teats O. elliptica
Oocystis Borgei Snow 1903, p. 379
Pl. 51, Fig. 10
Unicellular or crowded in groups of 2-8, inclosed by the old
mother cell wall; ellipsoid or ovate cells with the poles broadly
rounded and smooth; chloroplasts 1 or as many as 4 parietal plates,
each with a pyrenoid; cells (9)-12-13 in diameter, (9)—-10-19p
long; colony of 8 cells, up to 31 in diameter, 46, long.
Lemmermann (1903) has assigned this species, as a variety, to
O. gigas.
Common in the plankton of soft water lakes; often appearing
among filamentous algae in shallow water. Mich., Wis.
Oocystis crassa Wittrock in Wittrock & Nordstedt 1880, p. 117
Pitot. Kig.9
Unicellular or in colonies of 2-8, inclosed by a much swollen and
gelatinized mother cell wall; cells ovate, the poles broadly rounded
and furnished with a nodular thickening; chloroplasts several (as
many as 10) large parietal discs, with pyrenoids usually present;
cells 10-20, in diameter, 14-26, long.
Rare; in plankton. Mich., Wis.
[ 248 ]
Oocystis elliptica W. West 1892, p.736
Plot Bigs
Colony composed of 4-8 oblong-ellipsoid cells inclosed by the
irregularly swollen old mother cell wall; poles of the cells broadly
rounded and without polar thickenings; chloroplasts numerous (as
many as 20) parietal discs, apparently without pyrenoids; cells
11-15.6, in diameter, 20-21.4—( 25)» long.
Common in the plankton of many soft water lakes and ponds;
frequent in ditches and swamps, especially where there are luxuriant
growths of algae and where the water is rich in organic acids. Mich.,
Wis.
Oocystis elliptica var. minor West & West 1894, p. 14
Cells smaller than in the typical plant, 7-10 in diameter, 15-22u
long. Common in plankton. Wis.
Oocystis Eremosphaeria G. M. Smith 1918, p. 630
Pl. 51, Fig. 12
Plants unicellular, usually solitary, sometimes in a group of 2 or
4 within the old mother cell wall; cells narrowly ovate, the poles
broadly rounded and furnished with a large nodular thickening;
chloroplasts numerous, as many as 60 parietal, lenticular discs, each
with a pyrenoid; cells 20-25-(31), in diameter, 35-45, long.
The larger specimens always seem to be found in habitats where
there is a rich mixture of algae in shallow, warm water.
Plankter; in many lakes and sloughs. Mich., Wis.
Oocystis gigas Archer 1877, p.105
P1.51, Fig. 14
Plant usually a family of 4 broadly ellipsoid or ovate cells inclosed
within a much enlarged, elliptical mother cell wall; cells broadly
rounded at the poles, which are smooth and without nodules;
chloroplasts many parietal discs; pyrenoids not observed; cells
29--35-(40) » in diameter, 40-51.8y long.
Rare; in plankton. Mich., Wis.
Oocystis gloeocystiformis Borge 1906, p. 23
Pl. 51, Fig. 13
Plant usually composed of a family of 2 or 4 ellipsoid cells inclosed
within the old mother cell wall; cells with narrowed and sharply
rounded poles, without nodular thickenings; 1 parietal chloroplast in
each cell, pyrenoid lacking; cells (8)—11p in diameter, 8-18.5, long.
The poles of the cells of this species are somewhat produced to
[ 244 ]
form blunt points, giving an appearance of nodular thickenings.
This may be interpreted as a modification of the nodule character
which is common to many species, and from the evidence at hand
it would seem logical to include O. gloeocystiformis with that section
of the genus characterized by the possession of polar nodules. Our
specimens compare more closely with the plant figured by Borge
(1906) than with those shown by Smith (1920).
Among other algae in a few soft water lakes and swamps. Wis.
Oocystis lacustris Chodat 1897, p. 119; 1897a, p. 296
Pl. 54, Fig. 1
Plants usually in families of 2-8 within enlarged, oval mother
cell walls; cells broadly elliptic or moniliform, the poles furnished
with large nodular thickenings; chloroplasts 1-8 parietal plates,
usually containing 1 pyrenoid; cells 12-20, in diameter, 16-28, long.
Common in the plankton of several soft water lakes. Mich., Wis.
Oocystis natans (Lemm.) Wille 1911, p. 58
Cells ellipsoid with sharply pointed poles, without nodular
thickenings, united in families of 8; cells 12-15, in diameter, 23-26
long; chloroplasts 4-8 star-shaped plates.
Typical plant not observed in our collections.
Oocystis natans var. major G. M. Smith 1918, p. 630
Pl. 54, Fig. 2
A family of 2 or 4 ovate cells inclosed in the much expanded old
mother cell wall; poles of the cells rather sharply rounded but
without polar nodules; chloroplasts 4-8 in number, parietal, lobed
or star-shaped plates, each containing a pyrenoid; cells 16-25, in
diameter, 31-38, long; families about 90, in diameter, 120, long.
Plankter; common. Wis.
Oocystis nodulosa West & West 1894, p. 15
PI. 54, Figs. 6,7
Cells solitary, or 2 within old mother cell wall; ellipsoid to oblong-
ellipsoid, with rounded apices bearing a papillate thickening which
projects both inward and outward; 16-18, in diameter, 25-30, long.
Rare; in plankton. Wis.
Oocystis novae-semliae Wille 1897, p. 26
Cells ellipsoidal with thick walls; 4 or 8 individuals inclosed by
the old mother cell wall; poles of cells without nodular thickenings;
cells 5p in diameter, 8» long.
Typical plant not represented in our collections.
[ 245 ]
Oocystis novae-semliae var. maxima West & West 1894, p. 13
A variety differing from the typical plant by its much greater
size, 12-15y in diameter, 19-23 long; colony 23-42 in diameter,
40-52 long.
Plankter; in several lakes. Wis.
Oocystis panduriformis West & West 1894, p. 15
A family of 4 oblong-ovate cells with emarginate, concave lateral
walls; cells broadly rounded at the poles and furnished with a
conspicuous nodular thickening; chloroplasts numerous, parietal
discs, each with a pyrenoid; cells 23-25, in diameter, 50-61.5p long.
Typical plant not represented in our collections.
Oocystis panduriformis var. minor G. M. Smith 1916, p. 471
PI. 54, Fig. 11
A variety differing from the typical plant by its smaller size,
12-20 in diameter, 30-41» long; colony of 4 cells up to 59, in
diameter, 103, long.
Euplankter. Wis.
Oocystis parva West & West 1898, Jour. Bot., 36, p. 335
Pl. 54, Fig. 3
One-celled or in families of 2-8 individuals, inclosed by the
enlarged mother cell wall of the previous generation; 2-4 generations
sometimes involved; cells ellipsoid or fusiform with pointed poles
which are not furnished with definite polar nodules; chloroplasts
1 to 3 parietal discs, pyrenoids sometimes present; cells 4—7.5y in
diameter, 6-15.6, long; colony up to 43.9 in diameter.
Common in the tycho- and euplankton of several lakes and bogs.
Mich., Wis.
Oocystis pusilla Hansgirg 1890, p.9
Pl. 51, Fig. 15; Pl.54, Figs. 4,5
A colony of 4 ovate cells inclosed by the enlarged mother cell
wall; poles of the cells broadly rounded, without nodular thicken-
ings; chloroplasts 1 or 2 parietal plates, pyrenoids sometimes present;
cells 3.8-7.5, in diameter, 6-12, long.
Plankter. Uncommon but found in several lakes. Mich., Wis.
Oocystis pyriformis Prescott 1944, p. 357
PI. 54, Figs. 8, 9
Cells broadly pyriform-ovoid, with a prominent apiculation at
one pole, the other end broadly rounded; united in families of 2
[ 246 ]
or 4; chloroplast massive and parietal with 1 pyrenoid; cells 14-16p
in diameter, 16-19» long; colony of 4 cells up to 36 in diameter,
48.8y long.
This species should be compared with O. apiculata W. West, a
much smaller plant with broadly elliptic cells.
Plankter; in a cedar swamp. Wis.
Oocystis solitaria Wittrock in Wittrock & Nordstedt 1879, p. 24
Pl. 54, Fig. 10
Often solitary, or in a family of 2-8 cells inclosed by the old
mother cell wall; cells ovate or ellipsoid; poles with nodular
thickenings; chloroplasts numerous parietal plates, each with a
pyrenoid; cells 3-9, in diameter, 7-20, long.
Common in the euplankton of lakes; also in tychoplankton among
filamentous algae. Mich., Wis.
Oocystis solitaria var. major Wille 1879, p. 26
A form differing from the typical by having sharply pointed poles
and by its larger size, about 16.5y in diameter, 29» long.
Rare; in plankton. Wis.
Oocystis submarina Lagerheim 1886, p. 45
Pl. 54, Fig. 12
Usually a family of 2-16 oblong-cylindrical cells, rarely solitary;
cells narrowed at the poles and furnished with a nodular thickening;
chloroplasts 1-3 parietal plates with 1 pyrenoid each; cells 3-9
in diameter, 7-20y long.
Rare; in eu- and tychoplankton. Mich., Wis.
GLOEOTAENIUM Hansgirg 1890, p. 10
A free-floating, spherical or quadrangular-ovate colony of 2-8
globose or ellipsoid cells compactly and cruciately arranged within
the persistent mother cell wall; cells separated within the colony
by dark-colored masses of mucilage containing calcium carbonate,
usually appearing as 2 X-shaped bands and sometimes almost
entirely masking the inclosed cells, a cap of dark mucilage also
appearing between the cells and the colonial membrane; chloroplast
massive and indeterminate in shape.
There is but 1 species in this genus; it is rather rare and widely
distributed.
[ 247 ]
Gloeotaenium Loitelsbergerianum Hansgirg 1890, p. 10
Pl. 54, Figs. 13, 14
Characteristics as described for the genus; cells globose or ovoid,
18-25-(30), in diameter; 8-celled colony as much as 70 in diam-
eter, 80 long.
In tychoplankton of lakes, in soft or semi-hard water. Mich., Wis.
NEPHROCYTIUM Naegeli 1849, p. 79
A colony of 4-8 cells, varied in shape, ovate, fusiform, hemispheri-
cal, or oblong-ellipsoid to reniform, inclosed by the much enlarged
persistent mother cell wall, which may gelatinize and coalesce
somewhat, permitting daughter colonies to adhere together, thus
forming colonial complexes; occasionally 2 generations of cells
inclosed by 1 mother cell wall; chloroplast a parietal plate, which
becomes very diffuse in older cells; 1 pyrenoid.
Key to the Species
1. Cells broadly ovate or hemispherical, 133 times longer than wide_____________ 2
1. Cells lunate, fusiform, or reniform, 2-3 times longer than wide____._____. 3
2. Old mother cell walls gelatinized and persisting as fragments
about the colony; cells 13-18 in diameter,
broadly ovate or hemispherical... N. ecdysiscepanum
2. Old mother cell wall firm and thick; cells hemispherical or
very broadly ovate, up to 28 in diameter. N. obesum
8. Investment of cells formed by gelatinized mother cell
walls; cells curved or sausage-shaped_.___-_= N. limneticum
8. Investment of cells formed by persistent and firm mother cell walls______ 4
4Ui@ellssreniforn 22.4 choles a0 atl ey Wa Lead. Ee OSE N. Agardhianum
4x Cells shumatersses sb’ a: 58 tp loa Toe eh 6? ses ele Peek el Gane a a N. lunatum
Nephrocytium Agardhianum Naegeli 1849, p.79
[N. Naegelii Grunow]
Pl. 54, Figs. 15, 16
Colony ovate, composed of 2-8 cylindrical or reniform cells,
twisting so as to give a spiral arrangement within the old mother
cell wall; cells 2-7 in diameter, 8-18, long.
Rather common in the tychoplankton of several lakes and ponds.
Mich., Wis.
Nephrocytium ecdysiscepanum W. West in West & West 1896, p. 161
Pl. 54, Fig. 17
Colony broadly ovate, composed of 4-16 ovate, ovoid, or nearly
hemispherical cells inclosed by the old mother cell wall, the family
adjoined or adhering to other families by the gelatinized and
[ 248 ]
fragmentary remains of cell walls of previous generations, the
complex often forming a fan-like arrangement; cells (13 )-15.6-18u
in diameter, 30-32 long; colony of 4 cells about 60.4 in diameter.
Rare; in lakes and swamps. Wis.
Nephrocytium limneticum (G. M. Smith) G. M. Smith 1933, p. 503
Pl. 54, Fig. 18
Colony subspherical, composed of 4-8 curved, crescent- or
sausage-shaped cells with broadly rounded ends; mother cell wall
of previous generation completely gelatinized and not persisting as
a membrane; cells 7.4 in diameter, 10-25, long.
Reported as Gloeocystopsis limneticus G. M. Smith from Wis-
consin.
Euplankter; in ponds and lakes. Mich.
Nephrocytium lunatum W. West 1892, p. 736
Pl. 54, Fig. 19
Colony ovate, consisting of 4-8 lunate, bluntly-pointed cells
inclosed by a thin, hyaline membrane and arranged so that the
concave wall is directed toward the center of the colony; chloroplast
covering the cell wall; cells 4—5y in diameter, 14-18, long.
Tychoplanktonic in swamps; in ditches. Wis.
Nephrocytium obesum West & West 1894, p. 18
Pl. 54, Fig. 20
Colony broadly ovate, composed of 2-4 broadly ovate to hemis-
pherical cells inclosed by a thick membranous integument, the cells
broadly rounded at the poles and with one margin strongly convex,
the other straight or concave; chloroplast massive, somewhat
reticulate and covering the entire wall; cells 14-16-(28) in diam-
eter, 30-33-(49 ) » long.
This species should be compared with N. ecdysiscepanum.
Tychoplankter; in ponds and lakes. Mich., Wis.
LAGERHEIMIA (DeToni) Chodat 1895, p. 90
[Chodatella Lemmermann 1898]
A solitary, free-floating, moniliform, ovate, or ellipsoid cell with
a rather thick wall beset with long, tapering, needle-like setae which
are confined to the polar or to the equatorial region; chloroplasts
1-4 parietal plates, with or without pyrenoids.
Key to the Species
ie Gellspmonilitors 25 ee mee eee oe ee L. citriformis
EeeCelistovate Or cllipsoig sewers 2. PN le ee a 2
2. Setae more than twice the length of the cell... L. longiseta
2. Setae shorter, twice the length of the cell or less__.... 3
3. Cells with 2 diverging setae arising near each apex.____ L. quadriseta
3. Cells with more than 2 setae, arising at the apices of the cell.
4. Cells with 2-4 setae arising from each pole; cells ovate L. subsalsa
4. Cells with 3-8 setae arising from each pole; cells oblong-ovate_____- L. ciliata
Lagerheimia ciliata ( Lag.) Chodat 1895, p. 90
Pl. 55, Fig. 1
Cells oblong-ovate with 3-8 (usually 6) fine, tapering setae at
each pole; chloroplasts 1-4 parietal plates, each with a pyrenoid;
cells 6-184 in diameter, 10-21, long; setae 15-20p long.
Rare; in plankton. Mich., Wis.
Lagerheimia ciliata var. minor (G. M. Smith)
G. M. Smith 1920, p. 129
Pl. 55, Fig. 2
A variety with smaller, ovate, cells, 6-7.5, in diameter, 8-10, long;
setae up to 20, long.
Rare; in plankton. Wis.
Lagerheimia citriformis (Snow) G. M. Smith 1920, p. 130
Pl. 55, Fig. 4
Cells ellipsoid, moniliform with knob-like extensions at the poles
(giving an Oocystis-like appearance to the cell); 4-8 long tapering
setae arranged in a whorl at each pole; 1 parietal chloroplast con-
taining a single pyrenoid; cells 8-20 in diameter, 13-23» long
without the setae, which are 25-35, long.
Rare; in plankton. Mich., Wis.
Lagerheimia citriformis var. paucispina
Tiffany & Ahlstrom 1931, p.462
Pl. 46, Fig. 4
Cells the same shape as the typical but smaller, 8-9, in diameter,
10-14, long; each pole provided with 2-4 setae.
Mich.
Lagerheimia longiseta (Lemm.) Printz 1914, p. 60
Pl. 55, Fig. 5
Cells ovate or ellipsoid, with very long setae (more than twice
the length of the cell) arranged in a whorl] of 4-10 close to the poles;
1 (?) parietal chloroplast without a pyrenoid; cells 5-8, in diameter,
9-13, long without setae; setae 40-55, long.
Rare; in plankton. Mich., Wis.
[ 250 ]
Lagerheimia longiseta var. major G. M. Smith 1920, p. 130
Pl. 55, Fig. 6
A variety differing from the typical by its pointed ovate cells
which are considerably larger, 12-15u in diameter, 15-22y long
without setae; setae 45-60, long; described as having 1-2 chloro-
plasts, each with a pyrenoid.
Rare; in plankton. Mich., Wis.
Lagerheimia quadriseta (Lemm.) G. M. Smith
Pl. 46, Fig. 11
Cells ovate, with 2 long, diverging setae arising near the apices;
cells 46.5 in diameter, 7.5-12 long; setae up to 23, long.
Mich.
Lagerheimia subsalsa Lemmermann 1898, p. 193
PI. 59,, Fig. 7
Cells ovate, with a tuft of 2-4 setae at the poles; 1 parietal
chloroplast with a pyrenoid; cells 2.5-8. in diameter, 5-12» long
without setae; setae 7.5-26, long.
Rare; in plankton. Mich., Wis.
FRANCEIA Lemmermann 1898c, p. 307
Free-floating ovate or ellipsoid cells, solitary or 2-4 together;
walls covered with long, slender bristle-like setae which may show
a basal swelling or tubercle; chloroplasts 1-4 parietal plates; pyre-
noids present or absent.
This genus should be compared with Lagerheimia in which the
setae are confined to the polar or equatorial regions of the cell wall.
Key to the Species
ells ellipsaia, chloroplasts 2—4 6A oes Ne F. Droescheri
Cells ovate: “chiloroplasts l—2—-(3)) 3, ee F. ovalis
Franceia Droescheri (Lemm.) G. M. Smith 1933, p. 505
PI. 56, Figs. 1-3
Cells broadly ellipsoid, the wall covered with stiff, straight,
spine-like bristles without tubercular thickenings at their bases;
chloroplasts 2—4 parietal plates; cells 5-124 in diameter without
setae, 9-16y long; setae 15-22, long.
Euplankter. Mich., Wis.
Franceia ovalis (Francé ) Lemmermann 1898c, p. 308
Pl. 56, Fig. 4
Cells ovate; chloroplasts 1-2-(3) parietal plates; cells 7-10, in
diameter, 13-17, long without setae; setae 15-23, long.
Rare; in plankton. Mich., Wis.
[ 251 ]
DIMORPHOCOCCUS A. Braun 1855, p. 44
Colony free-floating; cells arranged in groups of 4 on the branched
wall fragments of the previous generation, not inclosed in mucilage;
quartets of cells composed of 2 ovate or subcylindric and 2 reniform
or cordate individuals; 1 chloroplast, parietal, with 1 pyrenoid.
Dimorphococcus lunatus A. Braun 1855, p. 44
Pl. 55, Fig. 8
Cells in groups of 4 on the ends of fine, branched threads com-
posed of the fragments of the mother cell wall, the 2 inner cells of
the quartet ovate or subcylindric, the 2 outer cells cordate; cells
4-15y in diameter, 10-25, long; chloroplast 1, a parietal plate nearly
covering the entire cell wall in mature individuals.
Common and widely distributed; especially in the plankton of
soft water lakes and acid bog ponds. Mich., Wis.
ANKISTRODESMUS Corda 1838, p. 196
Cells acicular, crescent-shaped, or narrowly fusiform; solitary or
clustered in fascicles, sometimes straight, usually curved, and often
twisted about one another; without a gelatinous envelope. Chloro-
plast a thin, parietal plate covering most of the cell wall; pyrenoid
present or absent.
Members of this genus are frequently found in great abundance
in small pools, along with species of Scenedesmus, coloring the
water green. They are common pioneers in waterlily and other
artificial ponds and laboratory aquaria. Care is needed to distinguish
some species of Ankistrodesmus from the myxophycean genus
Dactylococcopsis.
Key to the Species
1. Cells sigmoid or spirally twisted, sometimes wound about one another___. 2
1Y Cells fusiform; ‘straight’ or luuate, not. twisted === = Se 8
2. Cells slender and elongate, spirally twisted
about one another, forming bundles: 2 = A. spiralis
2. Cells wider and stouter than above, sigmoid-arcuate, twisted
at the apices only, not forming bundles —_____________________-- A. convolutus
3. Cells straight, or nearly so, broadly fusiform, solitary. A. Braunii
3. Cells narrower than above, curved or lunate, or if straight,
endingiin long meed|e: points eee 4
4. Cells fusiform or lunate, straight, or curved,
Uistallysentanpled) Or Clustered sess eee eee A. falcatus
4. Cells arcuate, dorsal walls straight from the midregion to the
sharply pointed apices; cells always solitary. A. fractus
[ 252 ]
Ankistrodesmus Braunii (Naeg.) Brunnthaler 1915, p. 189
Pl. 46, Fig. 8
Cells relatively broadly fusiform, lateral margins convex but
irregularly so, narrowed at either pole to short points (not drawn
out into long needle points as in most species of the genus);
chloroplasts 2 parietal plates; cells 8-10 in diameter, 20-25-56y
long.
Tychoplankter. Mich.
Ankistrodesmus convolutus Corda 1839, p. 199
Pl. 55, Fig. 3
Solitary or in groups of 2-4 cells, fusiform in shape, twisted and
sigmoid; apices sharply pointed and often twisted in opposite
directions; cells 3-4.5, in diameter, 15-25, long.
Common in the tychoplankton. Mich., Wis.
Ankistrodesmus falcatus (Corda) Ralfs 1848, p. 180
Pl. 56, Figs. 5, 6
Cells needle-like to somewhat spindle-shaped, solitary or in
clusters of 2-32 individuals, not inclosed in a colonial sheath;
chloroplast 1, a parietal plate without pyrenoids; cells 2-6 in
diameter, 25-100» long, sometimes longer.
Ubiquitous; intermingled with other algae and most commonly
found in acid water habitats of high temperatures where there is
a dense conglomeration of unicellular and colonial algae. Mich., Wis.
Ankistrodesmus falcatus var. acicularis (A. Braun )
G. S. West 1904, p. 223
Pl. 56, Fig. 16
Cells solitary and almost straight, the outer wall slightly curved
in the median portion, extended into long, finely drawn out apices;
chloroplast extending over 24 of the cell wall; cells 2.54 in diameter,
36-65, long.
Tychoplankter; rare in several lakes. Mich., Wis.
Ankistrodesmus falcatus var. mirabilis (West & West)
G. S. West 1904, p.224
Pl. 56, Fig. 10
Cells sigmoid or lunate, apices gradually tapering to fine points;
cells solitary, 2-3 in diameter, as much as 150, long.
Generally distributed. Mich., Wis.
[ 253 ]
Ankistrodesmus falcatus var. stipitatus (Chod. )
Lemmermann 1908, p. 176
Pl. 56, Figs. 14, 15
Cells lunate (rarely almost straight), attached at one pole to
filamentous algae or other submerged aquatics; usually gregarious,
forming clusters of 2-8; cells 3-4» in diameter, 18-22p long.
Plankter. Wis.
Ankistrodesmus falcatus var. tumidus (West & West)
G. S. West 1904, p. 224
Pl. 56, Fig. 9
Cells lunate or fusiform, the ventral margin decidedly tumid in
the midregion, 4.5-6.5, in diameter, 61-73» long.
Rare; in plankton. Wis.
Ankistrodesmus fractus (West & West) Brunnthaler 1915, p. 189
Plro6a hig. 7
Solitary, arched-fusiform or arcuate cells, the outer wall convex
in the median portion only, with almost straight walls extending
to the sharply pointed apices, the inner margin concave in the
median portion, straight toward the apices; cells 2.8» in diameter,
40-43.5p long; chloroplast divided into 4 portions by deep folds
or incisions.
Rare; in the plankton of Sphagnum bogs. Wis.
Ankistrodesmus spiralis (Turner ) Lemmermann 1908, p. 176
Pl, 56, Figs. 11, 12
Cells spindle-shaped, spirally twisted into bundles of 4-16 cells;
cells 2-3, in diameter, 25-35, long; chloroplast a parietal plate
without a pyrenoid.
Common in a variety of ponds and lakes; tycho- and euplanktonic.
Mich., Wis.
DACTYLOCOCCUS Naegeli 1849, p. 85
Pseudo-filamentous, consisting of ovate or fusiform-elliptic cells
attached end to end, filaments breaking up to form single, scattered
cells or small chains of cells; chloroplast a parietal plate, with or
without a pyrenoid.
See G. M. Smith 1933, p. 507, for a discussion of the systematic
position of this genus.
[ 254 ]
Dactylococcus infusionum Naegeli 1849, p- 85
Pl. 56, Fig. 13
Fusiform cells, either solitary or attached pole to pole to form
false, branched filaments or chains; chloroplast a_parietal plate,
sometimes with a pyrenoid; cells 2.5-3.5, in diameter.
From a laboratory culture. Wis. (Smith).
CLOSTERIOPSIS Lemmermann 1899a, p. 124
Cells long and needle-like, tapering to sharp points at both ends;
chloroplast a lobed plate extending almost the entire length of the
cell and containing a row of pyrenoids.
Closteriopsis should be compared with Closterium and Ankistro-
desmus. It is shaped much like some of the very slender species of
the former genus in which, however, there are two chloroplasts,
one on either side of a central nucleus. It is differentiated from
Ankistrodesmus on the basis of its greater size, stouter proportions,
and the axial row of pyrenoids.
Closteriopsis longissima Lemmermann 1899a, p. 124
[Ankistrodesmus longissimus (Lemm.) Wille]
Pl. 57, Fig. 1
Cells long and very narrowly spindle-shaped, the ends tapering
to fine points; chloroplast a parietal, lobed plate; cells 3.5-6y in
diameter, 190-240-(530) u long.
Rare; in the plankton of a few soft water lakes. Wis.
Closteriopsis longissima var. tropica West & West 1905, p. 31
Pl. 57, Figs. 2, 3
A variety of stouter proportions than the typical plant and not
tapering to a fine point but bluntly tipped at the poles; cells
6—7.5p in diameter, 225-370, long.
Plankter. Wis.
SCHROEDERIA Lemmermann 1898c, p: 311
Free-floating, unicellular, acicular, fusiform or straight, tapering
at the poles and forming long fine setae, one of which may terminate
in a disc or may be bifurcated near the end to form a pair of
recurved, bristle-like spines; 1 parietal chloroplast covering most of
the cell wall, with 1-3 pyrenoids.
Key to the Species
Cells as much as 20 times their diameter in length;
Smimes ts Dg lonpg: «seem ene ceeee raee kien S. setigera
Cells smaller, not more than 10 times their diameter
ma lempth-xspines PO—1Gu tome etek S. Judayi
[ 255 ]
Schroederia Judayi G. M. Smith 1916, p. 474
Pl. 57, Figs. 5,6
Cells fusiform, straight or arcuate, the poles narrowed and ex-
tended into long setae, one of which terminates in short bifurcations;
1 chloroplast, with a single pyrenoid; cells 2.5-6. in diameter,
45-63, long, including the setae, which are 10-16y long.
This species resembles an unattached Characium and should be
compared with some of the species of that genus.
Rare; in euplankton. Mich., Wis.
Schroederia setigera (Schroed. ) Lemmermann 1898c, p. 311
Pl. 57, Fig. 4
Cells fusiform, mostly acicular, the poles extended into long,
fine setae, one of which is bifurcate near the tip, forming recurved
bristles; chloroplast plate-like, covering most of the cell wall,
usually with 1 pyrenoid; cells 3-6, in diameter, 60-85, long, in-
cluding the setae, which are 13-17, long.
In plankton of lakes. Wis.
SELENASTRUM Reinsch 1867, p. 64
A colony of 4-16 lunate or sickle-shaped cells with acute apices,
the dorsal or convex walls adjacent; not inclosed by a gelatinous
envelope; chloroplast 1, parietal, lying along the convex wall,
usually with 1 pyrenoid.
Species of this genus should be compared with Kirchneriella
which has somewhat scattered lunate cells within a gelatinous
envelope.
Key to the Species
1. Cells decidedly sickle-shaped, 19-28 from tip to tip___________ S. gracile
1. Cells lunate (crescent-shaped ), or arcuate but not
sickle:shaped, mostly: smaller. .- 6. ee eee 2
D, Gellis areata, Usain, tin Clam S. Westii
2-1 Cellsilunate,slarteninididmeter. 2-22 eee 8
3. Cells 5—8u in diameter, 16—42u from tip to tip.................... S. Bibraianum
3. Cells (2)—3 in diameter, 7-94 from tip to tip S. minutum
Selenastrum Bibraianum Reinsch 1867, p. 64
Pl. 57, Fig. 9
Colony ovate in outline, composed of 4-16 lunate or sickle-shaped
cells with sharp apices and arranged so that the convex surfaces
are apposed and directed toward the center of the colony; cells
5-8. in diameter, 20-38, long; distance between apices 16—42u.
Rare; in several lakes, mostly soft water, and in acid swamps.
Mich., Wis.
[ 256 ]
Selenastrum gracile Reinsch 1867, p. 65
PI. 57, Fig. 11
Colonies of 8-64 sickle-shaped cells in irregular arrangement, but
with the convex surfaces apposed; apices of the cells sharply
pointed; chloroplast a parietal plate along the convex wall, without
a pyrenoid (?); cells 3-5 in diameter, 19-28, between apices.
In tychoplankton of lakes and swamps. Mich., Wis.
Selenastrum minutum (Naeg.) Collins 1909, p.171
Pl. 46, Fig. 10
Cells often solitary or in small families, irregularly arranged,
crescent-shaped, the poles bluntly pointed; cells 2-3 in diameter,
7-9. between apices.
Mich.
Selenastrum Westii G. M. Smith 1920, p. 133
Pl. 57, Fig. 10
Colony small, composed of 2-8 slender, lunate or arcuate (but
not sickle-shaped) cells, arranged with their convex walls apposed;
chloroplast a parietal plate lying along the convex wall; pyrenoid
lacking (?); cells 1.5-2.51 in diameter; 15-18 between apices.
Rare; in euplankton. Mich., Wis.
KIRCHNERIELLA Schmidle 1893, p. 83
Free-floating or caught among larger algae; a colony of strongly
curved, lunate, sickle-shaped or twisted fusiform, sometimes cylin-
drical cells, inclosed by a gelatinous envelope in which there is
no regular arrangement of individuals although young colonies may
have even numbers of individuals, and these are usually arranged
so that the convex walls are together; chloroplast a parietal plate
along the convex wall, with 1 pyrenoid.
Key to the Species
1. Cells inclosed by the persistent mother cell
wallofithe laskicemerationes = en epee K. subsolitaria
1. Cells inclosed by a copious mucilaginous sheath __________»_________ 2
2. Cells vermiform cylinders, rounded at the poles ____________________________-___- 8
2. Cells lunate, sickle-shaped, sharply or bluntly pointed at the apices 4
3. Cells small, 2u or less in diameter, up to 14u long == K. contorta
3. Cells larger, 2-3u in diameter, up to
Dap wlonp) spinal ys tis ecd meee seis oe anh ile ee ee ee K. elongata
4, Cells narrowed at the poles, rounded or bluntly pointed_________ K. obesa
4, (Cellsisharply pointed’ at the: poles: =) 20s.) 2) a 3) K. lunaris
[ 257 ]
Kirchneriella contorta (Schmidle) Bohlin 1897, p. 20
Pl. 57, Figs. 7, 8
Free-floating colonies, usually of 16 twisted, arcuate, cylindrical
cells with broad, convex apices, lying irregularly scattered through-
out the homogeneous, gelatinous envelope; chloroplast covering the
entire wall of the cells, which are 1-2 in diameter, 5.8-10-(14)y
long.
fae! in plankton of several lakes. Mich., Wis.
Kirchneriella elongata G. M. Smith 1916, p. 473
Pl. 58, Fig. 1
Colonies composed of 4-16 elongate-cylindrical, spirally twisted
cells which have rounded apices; individuals much entwined near
the center of the homogeneous colonial envelope; 1 parietal chloro-
plast, without a pyrenoid; cells 2-3» in diameter, 15-25, long;
colonies up to 100, in diameter.
Rare; in the plankton of several lakes. Mich., Wis.
Kirchneriella lunaris (Kirch. ) Moebius 1894, p. 331
Pl. 58, Fig. 2
Colony composed of numerous cells arranged in groups of 4-16
within a close, gelatinous envelope; cells flat, strongly curved
crescents with rather obtuse points; chloroplast covering the convex
wall; cells 3-8. in diameter, 6.5-13, long; colonies 100-250,» in
diameter.
Common in the plankton of open water or among mats of algae
in the shallow water of acid ponds and lakes. Mich., Wis.
Kirchneriella lunaris var. Dianae Bohlin 1897, p. 20
Pl. 58, Fig. 3
A variety differing from the typical in having very strongly curved
cells with sharply pointed apices which are not in the same plane;
cells 8-5u in diameter, 10-18-(21)» long.
Rare; in plankton of several lakes especially in acid habitats.
Mich., Wis.
Kirchneriella lunaris var. irregularis G. M. Smith 1920, p. 142
Pl. 58, Fig. 4
A variety differing from the typical by having the apices distinctly
twisted and very evidently pointing in different directions so that
a spiral sigmoid curve is produced; cells 4-6» in diameter, 6-13,
long.
Tae in plankton of a variety of lakes. Wis.
[ 258 ]
Kirchneriella obesa (W. West) Schmidle 1893, p. 16 [83]
Pl. 58, Fig. 5
Colony composed of many irregularly arranged cells in a wide
gelatinous envelope; cells strongly lunate, the outer margin convex
and the inner nearly parallel to it, tapering slightly to bluntly
pointed apices; chloroplast covering the entire convex portion of
the wall; cells 4-6 in diameter, 10-14, long.
Rare but widely distributed; in the plankton of many lakes. Mich.,
Wis.
Kirchneriella obesa var. aperta (Teil.) Brunnthaler 1915, p. 182
Pl. 58, Figs. 6,7
A variety in which the cells are less strongly lunate, with the
inner margin of the cell describing a much greater arc than the
outer; cells 7.4-10 in diameter, 10-14, long.
Rare; in the plankton of several lakes. Wis.
Kirchneriella obesa var. major (Bernard) G. M. Smith 1918, p. 636
Pioiebic. 2
A variety differing from the typical by having the inner and
outer margins nearly parallel, slightly tapering at the apices, which
are bluntly rounded; cells 3-5y in diameter, 10-18-(21), long.
Rare; in plankton. Mich., Wis.
Kirchneriella subsolitaria G. S. West 1908, p. 284
PI. 58, Fig. 8
Plant consisting of 4 strongly curved, crescent-shaped cells ar-
ranged together within old mother cell wall, the apices bluntly
rounded and not tapering; cells 3-4.5p in diameter, 10-14 long.
Euplankter. Wis.
QUADRIGULA Printz 1915, p. 49
A free-floating, ellipsoid colony of 2-4-8 long-cylindrical or fusi-
form cells with long axis parallel with that of the gelatinous sheath
in which they are inclosed; poles of the cells subacute or sharply
rounded; chloroplast a parietal plate covering most of the cell wall,
or sometimes located along one side; pyrenoid sometimes present.
Some species of this genus will be found treated under
Ankistrodesmus in a number of manuals. The two genera are
separable on the basis of their arrangement in the colony and the
common investing sheath, the latter not being present in
Ankistrodesmus.
[ 259 ]
Key to the Species
1. Cells spindle-shaped, numerous and scattered within a gelatinous
investment but with the longitudinal axes parallel...» Q. lacustris
1. Cells arcuate, lunate, or straight, arranged in bundles of 4
within the gelatinous investment, fewer in number than above 2
2. Cells straight, margins subparallel in the
median portion; poles rommded = es Q. closterioides
2; Cells arcuate or lunate; poles pointed QO. Chodatii
Quadrigula Chodatii (Tan.-Ful.) G. M. Smith 1920, p. 138
[Ankistrodesmus Chodati (Tan.-Ful.) Brunnthaler]
Pl. 59, Figs. 1-3
Free-floating; cells long, fusiform to slightly lunate or arcuate,
tapering to subacute points, longitudinally arranged within a
broadly fusiform colonial envelope; chloroplast a parietal plate with
a median notch, containing 2 pyrenoids; cells 3.5-7 in diameter,
30-80 long; colony as much as 250, long.
Rare; in euplankton of a few lakes as well as in the tychoplankton
of shallow water. Mich., Wis.
Quadrigula closterioides (Bohlin) Printz 1915, p. 49
Pl. 58, Figs. 9, 10
Cells long, straight, but with one margin slightly curved, cylin-
drical in the mid-region, tapering to sharply rounded apices,
arranged in longitudinal bundles of 4 within a fusiform colonial
envelope; chloroplast parietal, covering almost the entire cell wall,
with a median notch; 1 pyrenoid; cells 4-6, in diameter, 22-35-(45)p
long.
Common in many soft water lakes. Mich., Wis.
Quadrigula lacustris (Chod.) G. M. Smith 1920, p. 189
[Ankistrodesmus lacustris (Chod.) Ostenfeld]
Pl. 59, Figs. 4,5
A free-floating, fusiform-shaped colony containing many short,
fusiform cells, mostly arranged in pairs; cells straight, but with
slightly convex margins, tapering to blunt points; chloroplast a
parietal plate, sometimes twisted in the cell, without a median
notch, with 1 pyrenoid; cells 3-5y in diameter, 20—25y long.
Rare; in the plankton of many lakes, mostly soft water. Mich., Wis.
TETRAEDRON Kuetzing 1845, p. 129
Cells solitary and unattached; of various shapes, triangular and
flat, pyramidal, polyhedric; the angles entire, with or without spines,
[ 260 ]
w
or variously lobed to form dichotomous or trichotomous spine-tipped
processes; chloroplasts one to many parietal discs or plates;
pyrenoids usually present.
Key to the Species
1. Angles or poles of the cell smooth or tipped with spines
but not extended and produced to form processes 2
1. Angles of the cell extended and produced to form short or long
arms or processes, branched or unbranched... 19
2 Auelesstipped, Withl|| =o" SpINcs 222 sas wen amane cm eee 2A 8
ZaPancies smoot, or with a blunt spapillase se ee es eee 16
Sr anglesior tierce lvalluimione plane 22 2a ee eee Ss 4
oe anlples of theycell not all. ini oneplanc 7 9
em OC HSNCTES CONES Hae les meas Se avis fo Pad en se ute eee er T. lunula
Fame lS en Ota eLeSCent-Siid PEC a= =e au nie ee Se ee ee 5
bell Sea Det eae ee ee ee ee eran ek eee T. trigonum
Se Gellsmmore tthan3-an tiled 2a ne ee ee ee 6
CBs, CCGA Sa al (2 at ele a near aG a RL T. caudatum
GmCellswrtcan gles cme as 28 RL reg ne el eh a if
7. Cells deeply constricted on 2 sides, each of the
four lobes tipped with a spime—_ T. arthrodesmiforme
ie (Gellsmot*deeply, constricted on‘ 2sidesi= 2 27 sts 2) SAS
8: Gells tetrahedraly anargins concave 2-227 T. regulare
8. Cells quadrangular, margins straight____________----_-_-----_--_-- T. quadratum
9. Cells broadly ellipsoid in outline but with 3 scarcely evident
angles,-each tipped with a’short spine 222. T. obesum
9. Cells polyhedral or pyramidal, with 4-5 angles 10
OM Gelisfwith Ahan ples A 2): set om epee So Se ee ed 8 11
HOSGelis avitht oranges 21! os el alee T. pentaedricum
HTS Giga ryr An ele ee gh T. regulare
(see var. torsum)
11. Cells lobed, the lobes contorted, usually not all in the same plane. 12
Oe Cell cwalleveniiCose e:2- = oe hy Bree Een We Es T. verrucosum
Es Gel lea src tines 2 oe ae ee, ee ee 13
13. Angles of the cell tipped with 2 spines_______________________ T. bifurcatum
dis ae Ani mlestOtstaedce ll with hss pine: ak aE ea 14
14. Lobes of the cell long and gradually tapering, tipped with a
long, slender spine, the lobes forming 2 semicells and cruciately
arranged, 2 in one plane and 2 in another-_._._._.----.-.----.---------- *_T. Victoriae
14. Lobes of the cell short and abruptly tapering, all in different planes 15
15. Lobes twisted over one another, the angles
furmished with aslonpispine. «2 = T. arthrodesmiforme var.
(compare with T. Victoriae )
15. Lobes shorter and not twisted over one another;
angles tipped! witht a shortispine =< hee! Pe T. regulare
165) Gells*regularly. or irregularly pyramidal .."-- Le
16. Cells not pyramidal; triangular or quadrangular______________________ 18
17. Cells regularly pyramidal, symmetrically 4-lobed_._________ T. tumidulum
iveaGe lsvrrecularly o- Ol G-l@ueG ee ee T. gigas
aie C@clistetianelilar, etemeenmemnes oe ete POL Ne a ee T. muticum
TS meC@ells cqmaciam pul dns) ceeneeme Teel Pies eRe it T. minimum
[ 261 ]
19. Processes not divided and without secondary lobes — 20
IG MProcessesnaiviGd ed aot =a Ole tet a te maaan aed TT 293
20. Processes very short, angles scarcely produced
at all tipped wath 2 spines. 512013 Vel ae eee ee T. armatum
20.eAngles, ‘markedly, produced)» =. — AJA) 2 een ee oa 21
21. Cells cruciately lobed, the lobes in 1 plane,
deeply, bifurcatelatithe apices.) 5 sa. ae ee Bele ae ead, T. pusillum
21. Cells not cruciately lobed; lobes not all in the same plane... 2.2
22. Cells tetrahedral, pyramidal, the lobes long and
tapering, tipped with) 3. spines se 0) Civ i ee T. hastatum
22. Cells with short, asymmetrical lobes, not at all or scarcely
tapering, tipped with 2-3 blunt spines._.___»_-_ T. asymmetricum
23; Opes allcin the same tp larie mut Jee ae 2) eee 0h) il elles eal alma See OMe 24
23, Wobes not allyimicthe saine) plane see lt eae leat ee ean Hil
24. Cells definitely 4-lobed, the lobes forming
ain shaped igure (sete ve wih vont ei SEL APRIL a CR T. constrictum
24.) Cellssnot definitely vil -shaped x. sa4 Ws Lies he ap SL eee 25
25. Lobes and lobules of the cell long and slender, tipped with 2 spines 26
25. Lobes short and broad, rarely with secondary lobes —_--_____ T. cruciatum
26. Processes long and slender, much branched_______________________ T. gracile
26. Processes short, rarely with secondary lobes... T. lobulatum
27. Angles extended into very short, broad processes
winieh lravershorty secondary Wobes suse. mae ee eee T. enorme
27. Angles extended into long, tapering processes
with) long: narrow secondary lepes 2 es eee 28
28. Processes much branched
to the fifth order.....8.42. a NES Se T. lobulatum var. polyfurcatum
28: Processesswith: oor less Series of divisions. 2+ eee es 29
29. Body of the cell narrow, processes longer
than) thediametemobthe.cellt. 22 DU ew eee ee ae T. limneticum
29. Body of cell thick; processes shorter than
the\drameéter: ob thercelli tana a, ae et ol a T. planctonicum
Tetraédron armatum (Reinsch) DeToni 1889, p. 611
i PI. 59, Figs. 6,7
Cells irregularly triangular and lobed, the angles scarcely or not
at all produced, but furnished with a pair of widely separated
spines; the angles of the cell sometimes not all in the same plane,
so that 1 or 2 pairs of spines are seen one above the other when
viewed from the side; cell 30—47.6, in diameter.
Rare; in euplankton. Mich., Wis.
Tetraédron arthrodesmiforme (G. S. West) Woloszynska 1914, p. 203
Pl. 59, Fig. 8
Cells quadrate in outline, symmetrically incised to form 2 lobes;
a spine on each of the 4 angles; 2 sides of the cell subparallel,
convex, the isthmus bordered by a widely open sinus; cells up to
56u in diameter.
Typical form not reported from our region.
[ 262 ]
Tetraédron arthrodesmiforme var. contorta Wotoszynska 1914, p. 203
Pl. 59, Figs. 9, 10
A variety differing from the typical by having the 4 lobes twisted
and extending in at least 2 planes, a character which is particularly
evident when seen from the ‘side’; cell 25-32-(50) in diameter,
up to 60, in the longest dimension.
Rare; in euplankton. Wis.
Tetraédron asymmetricum Prescott 1944, p. 357
Pl. 59, Figs. 11-13
Cell quadrangular in outline, unsymmetrically incised to form 2
major lobes with an isthmus bordered by a widely open sinus, the
2 major lobes slightly bilobed, the lobules tipped with 2 or 3 short
spines; cells 10-18, in their longest dimension.
This species should be compared with T. irregulare (Reinsch)
DeToni.
Rare; in euplankton and tychoplankton. Wis.
Tedraédron bifurcatum (Wille) Lagerheim 1893, p. 160
Pl. 59, Fig. 14
Cells irregular tetrahedrons, the lobes tipped by 2 short spine-
bearing processes, the margins of the cell concave between the
apices of the lobes; maximum diameter of the cell 55-60x.
Rare; in plankton of lakes; tychoplanktonic in swamps. Wis.
Tetraédron bifurcatum var. minor Prescott 1944, p. 358
Pl. 59, Figs. 15, 16
A form differing from the typical by its small size and in having
the lobes bifurcated, the lobules rather stu1t and tipped with a
short spine; cells up to 22.5y in their maximum diameter.
Rare; in tychoplankton. Wis.
Tetraédron caudatum (Corda) Hansgirg 1888a, p. 131
PI. 59, Figs. 17, 24, 25
Cells flat, 5-sided, the angles rounded and tipped with a short,
sharp spine, the sides between the angles concave, but with one
margin narrowly and deeply incised; cells in their longest dimension
8-15—(22) u.
Tetraédron caudatum var. incisum Lagerheim, reported from
Michigan by Taft (1939), does not seem to be separable from the
typical form. The sinus of the incision on the margin is very narrow.
In tychoplankton; in shallow water of lakes and in swamps. Wis.
[ 263 ]
Tetraédron caudatum var. longispinum Lemmermann 1898d, p. 151
Pl. 59, Figs. 20-22
A variety differing from the typical by having longer spines which
are directed at right angles to the flattened surface of the cell, 2
turned in one direction, 3 in the opposite; cells 8-18, in diameter;
spines 3-8, long.
Euplankter; in lakes. Wis.
Tetraédron constrictum G. M. Smith 1920, p. 122
Pl. 59, Fig. 28
Cells quadrangular in outline, tetragonal, 2 sides subparallel, the
other 2 deeply concave as seen in front view, the angles extended
into slightly tapering processes which are dichotomously branched
and tipped with a short spine; in side view fusiform, the processes
at the superimposed poles of the cell not quite in the same plane
but slightly turned at different angles; cells 5-8. in diameter,
without processes, 8u thick, 18-25, in their longest dimension.
Rare; in euplankton. Wis.
Tetraédron cruciatum ( Wallich) West & West 1902a, p. 198
Cells cruciately 4-lobed, the lobes bifurcate, one division of 2
lobes usually again divided; lobes and lobules tipped with 2 short
spines; margin of the cell deeply concave between the lobes, more
deeply so on 2 sides than on the others; cells (larger forms) 42-54y
or (smaller forms) 17, in diameter.
Typical plant not reported from our region.
Tetraédron cruciatum var. reductum Prescott 1944, p. 358
Pl. 59, Fig. 23
Cell flat, irregularly cruciform or sometimes 3-lobed, the lobes
bifurcate, the lobules tipped with a short spine; margins of the cell
concave on 2 opposite sides, straight or only slightly concave on the
other sides; cells 28-30, in diameter, up to 54, in the greatest
dimension.
Tychoplankter; in swamps. Wis.
Tetraédron duospinum Ackley 1929, p. 304
Pl. 46, Figs. 22, 23
This species, described as new from Michigan and illustrated
(Ackley, l.c., Pl. 35, Fig. 14), appears to be a Cystodinium or some
other encysted dinoflagellate. I have not seen type specimens, how-
ever.
Mich.
[ 264 ]
Tetraédron enorme (Ralfs) Hansgirg 1888a, p. 132
Pl. 52, Figs. 6,7 (var.); Pl. 59, Fig. 19
Cells poly- or tetrahedric, the angles shortly produced and bilobed,
the lobes bifurcate and tipped with short spines; margins of the cell
concave between the angles, the processes not all in the same plane;
cells (25)-30-( 45), in diameter.
Common in the tychoplankton of several lakes; generally distrib-
uted. Mich., Wis.
Tetraédron enorme var. pentaedricum Prescott 1944, p. 358
PI. 59, Fig. 18
Cells 5-sided in outline, the sides straight or slightly convex, with
pairs of narrow bifurcated processes extending in all planes, the
processes tipped with short spines; cells 50-55, in diameter, without
processes.
This form differs from the typical plant by its straight margins
and narrow bifurcated processes extending from the angles. It is
similar to Borge’s figure of T. enorme, which I judge to be typical.
Rare; in plankton. Wis.
Tetraédron gigas (Wittr.) Hansgirg 1888a, p. 131
Cells relatively large, irregularly 5- or 6-angled, the processes
broadly rounded, with the margins between the angles broadly
concave; cells 35-45, in the short diameter, 65-75, long.
Typical form not reported in our region.
Tetraédron gigas var. granulatum Boldt ex Brunnthaler 1915, p. 148
A variety differing from the typical by the possession of finely
punctate walls.
Mich.
Tetraédron gracile (Reinsch) Hansgirg 1889, p. 19
Pl. 60, Fig. 1
Cells flat, cruciform, rectangular in outline, the angles extended
into narrow, twice furcated processes which are tipped with 1 or 2
short spines, the margins deeply concave between the processes;
cells 15-30, in diameter, without processes, 35-40, wide including
processes; 6-12, thick.
Rare; in euplankton. Mich., Wis.
Tetraédron hastatum (Reinsch) Hansgirg 1888a, p. 132
PI. 59, Fig. 26
Cells pyramidal, the angles extended into narrow, slightly taper-
ing, unbranched processes which are tipped with 2 or 3 short spines,
[ 265 ]
the margins concave; cells 28—36y in diameter, processes 8p wide at
the base.
Rare; in plankton. Wis.
Tetraédron hastatum var. palatinum (Schmidle )
Lemmermann 1902, p. (247)
Pl. 59, Fig. 27
Cells pyramidal, the processes longer and more graceful, not
tapering, tipped with 3 short spines, the margins of the cell convex;
cells 4-14, in diameter without processes.
Euplankter. Wis.
Tetraédron limneticum Borge 1900, p. 5
Pl. 60, Figs. 2-4
Cells pyramidal, 4-angled, the angles produced into relatively
narrow, once or twice furcated processes which are tipped with
short spines, the margins of the cell concave between the angles;
cells 30-55-( 85) in diameter including processes.
Common and generally distributed in many lakes. Mich., Wis.
Tetraédron limneticum var. gracile Prescott 1944, p. 358
Pl. 60, Fig. 5
Cells pyramidal or tetragonal, the angles extended into bifurcate
processes which are tipped with 2 or 3 stout spines, the margins of
the cell concave between the processes; bases of the processes
adjoining so that there is scarcely a cell body; cells 40-46.8, in
diameter; processes 6-8 wide.
Euplankter. Wis.
Tetraédron lobulatum (Naeg.) Hansgirg 1888a, p. 132
Pl. 60, Figs. 6, 7
Cells tetragonal, mostly pyramidal (or flattened); processes short
and stout, bifurcate at the apices; cells 35-40, in diameter.
Euplankter. Mich., Wis.
Tetraédron lobulatum var. crassum Prescott 1944, p. 359
Pl. 60, Fig. 8
Cells tetragonal, pyramidal, the angles slightly produced to form
relatively wide, short processes which are bilobed, the lobules bi-
furcate and ending in short curved spine-like tips; cells 25-30, in
diameter.
[ 266 ]
This form differs from the typical by its broad, bilobed processes
and by the lateral walls of the cell being much less concave or
emarginate. It differs from var. polyfurcatum G. M. Smith in the
form and number of processes.
Planktonic in lakes; also found in Manitowish River, Wisconsin.
Tetraédron lobulatum var. polyfurcatum G. M.Smith 1916, p. 480
Pl. 60, Fig. 11
Cells tetragonal, pyramidal or flattened, the angles extended into
processes which are dichotomously divided 3 to 5 times, the lobules
ending in 2 or 3 minute spines; margin of the cell concave between
the processes; cells 15-25, in diameter without processes, 35-70, in
diameter including processes.
Rare; in the plankton of many lakes. Wis.
Tetraédron lunula (Reinsch) Wille 1911, p. 60
Pl. 60, Figs. 9, 10
Cells lunate, tapering to sharply pointed poles; the outer margin
more sharply curved than the inner, which is concave; cells 11-12y
in diameter, 25-30, long.
Plankter, in a small inlet of the Wisconsin River, Wisconsin.
Tetraédron minimum (A. Braun) Hansgirg 1888a, p. 131
Pl. 60, Figs. 12-15
Cells small, flat, tetragonal, the angles rounded and without spines
or processes, lobes sometimes cruciately arranged; margins of the
cell concave, with one frequently incised; cells (6)-14.5-20, in
diameter.
Common in the tychoplankton and euplankton of many lakes and
ponds. Mich., Wis.
Tetraédron minimum var. scrobiculatum Lagerheim 1888, p. 591
A variety differing from the typical by having deeply punctate
walls.
Mich.
Tedraédron muticum (A. Braun) Hansgirg 1888a, p. 131
Pl. 60, Figs. 16, 17
Cells small, flat, triangular, the angles without spines or furcations;
sides of the cell emarginate or slightly convex; cells 6-1$, in
diameter.
A common species in many habitats, but because of its small size
it is easily overlooked in rich tychoplanktonic collections. Mich., Wis.
[ 267 ]
Tetraédron muticum fa. punctulatum (Reinsch )
DeToni 1889, p. 600
Pl. 60, Fig. 18
Cells flattened, triangular, the angles sharp but without spines;
margins slightly convex; wall granular; cells 15-20, in diameter,
8-10u thick.
Euplankter. Wis.
Tetraédron obesum (West & West) Wille ex Brunnthaler 1915, p. 154
Pl. 60, Figs. 19, 20
Cells ovate or broadly elliptic in outline, but with 3 lobes
which are scarcely produced, one lobe lateral to the long axis of
the cell, all lobes tipped with a short sharp spine; cells 15y in
diameter, 31-35, long.
Plankter; in lakes and ponds. Mich., Wis.
Tetraédron pentaedricum West & West 1895, p. 84
Pl. 60, Figs. 21-23
Cells irregularly 5-lobed, with 1 lobe extended in a different
plane from the others; angles sharply rounded, the apex of each
lobe furnished with a sharp spine; diameter of cells 18-21,.
Rare; in euplankton. Mich., Wis.
Tetraédron planctonicum G. M. Smith 1916, p. 479
Pl. 60, Figs. 27, 28
Cells polyhedral-pyramidate, 4- or 5-angled, with convex sides,
the angles produced into once- or twice-furcate processes, becoming
narrower in the furcations, the lobes tipped with 2 or 3 spines;
cells 18-30, in diameter without processes, 45-60, including the
processes.
Common in the plankton of many lakes. Mich., Wis.
Tetraédron pusillum (Wallich) West & West 1897, p. 237
Pl. 60, Fig. 29
Cells cruciform, deeply 4-lobed, concave between the lobes, the
lobes bifurcate at the apices, all in one plane; cells elongate-elliptic
in side view; 10 in diameter, 25, long.
Plankter; found in several lakes; common. Mich., Wis.
Tetraédron quadratum (Reinsch) Hansgirg 1889, p. 18
Pl. 46, Figs. 21, 21a
Cells quadrangular in front view, the lateral margins straight
with sharp angles which are furnished with a short spine; membrane
2-layered, up to 4.5, thick; cells 17-34,» in diameter.
Mich.
[ 268 ]
Tetraédron regulare Kuetzing 1845, p. 129
Pl. 60, Figs. 24-26
Cells tetragonal, pyramidal, the angles produced to form stout
lobes, narrowly rounded and tipped with a single, stout spine; the
margins of the lobes convex or straight, lateral walls between the
lobes concave; cells (14)—45-51.8 in diameter.
Plankter; in many lakes and ponds; generally distributed. Mich.,
Wis.
Tetraédron regulare var. bifurcatum Wille 1884, p. 12
PI'6!, Figvl
Cells tetragonal, pyramidal, the sides convex or slightly concave,
the angles broadly rounded and tipped with 2 stout often curved
spines; cells 30-36 in diameter including spines.
Tychoplankter; in shallow water of lakes and sloughs. Mich., Wis.
Tetraédron regulare var. granulata Prescott 1944, p. 359
Pl. 61, Figs. 2,3
Cells large, pyramidal, the lobes broad and stout with convex
margins, the angles broadly rounded and tipped with a single short
spine which may be reduced to a mere papilla; wall punctate and
covered with small granules or roughenings; cells 35-51.8. in
diameter.
Plankter; in several lakes. Wis.
Tetraédron regulare var. incus Teiling 1912, pp. 274, 277
Pl. 61, Figs. 4-7
Cells tetragonal, flat or pyramidal, with concave lateral margins,
the angles slightly produced to form short lobes each tipped by a
relatively long spine; cells 15-20, in diameter without spines, up to
37, in diameter including spines.
Plankter; in several lakes. Wis.
Tetraédron regulare var. incus fa. major Prescott 1944, p. 359
P1.61, Fig. 13
Cells tetragonal, pyramidal, the margins straight or slightly convex,
the angles produced to form long, stout spines; cells 35-50,» in
diameter, including spines; spines 12-13.5, long.
Plankter; lakes and streams. Wis.
Tetraédron regulare var. torsum (Turner) Brunnthaler 1915, p. 150
Pl. 61, Figs. 8-10
Cells tetragonal, pyramidal, the lobes narrow and tapering to a
spine-tipped apex, twisted so that they are cruciately arranged;
[ 269 ]
lateral margins convex; sides of the cell concave between the lobes;
cells 25-33—( 40)» in diameter.
Tychoplankter. Mich., Wis.
Tetraédron trigonum (Naeg.) Hansgirg 1888a, p. 130
PI. 61, Figs. 11, 12
Cells flat, 3-angled, the angles tapering to sharply rounded, spine-
tipped apices; margins convex; sides of the cell body concave or
straight; cells 19-29.8, in diameter.
Common in the tychoplankton of several lakes. Mich., Wis.
Tetraédron trigonum var. gracile (Reinsch) DeToni 1889, p. 598
Pl. 61, Figs. 14-16
Cells flat, triangular, the angles narrower and more produced
than in the typical plant, sometimes curved, tapering acutely and
ending in a spine; cells 25-40y in diameter, including the spines.
Euplankter. Wis.
Tetraédron trigonum var. papilliferum (Schroed. )
Lemmermann ex Brunnthaler 1915, p. 149
A variety with only slightly concave margins, the angles tipped
with a blunt, wart-like papilla; cells 12-15, in diameter.
Mich.
Tetraédron tumidulum (Reinsch) Hansgirg 1889, p. 18
Pl. 61, Figs. 17, 18
Cells tetragonal, pyramidal, the margins straight, concave, or
convex; the angles bluntly rounded and sometimes with knob-like
extensions; cells 30-53, in diameter.
Plankter; in lakes and sloughs. Mich., Wis.
Tetraédron verrucosum G. M. Smith 1918, p. 632
Pl. 61, Figs. 24, 25
Cells tetragonal, pyramidal, sometimes with lobes cruciately
arranged; margins of the cell convex, the angles ending in a stout,
blunt spine; wall coarsely verrucose; cells 65-80% in diameter
including the spines, which are 13-18, long.
Rare; in euplankton. Wis.
Tetraédron Victoriae Wotoszynska 1914, p. 203
Cells deeply lobed to form 2 semicells which are subcruciform in
arrangement, the semicells bilobed, with the walls emarginate
[ 270 |
between the lobes; apices of the lobes rounded and tipped with a
short, blunt spine; cells 10-15, in diameter, 20-30, long.
Typical form not reported from our region.
Tedraédron Victoriae var. major G. M. Smith 1920, p. 119
Pl. 61, Figs. 28, 29
Cells 4-angled, divided into fusiform-shaped semicells, as seen
in vertical view, by deep emarginations, the two semicells bilobed
and cruciately arranged, each lobe produced into a stout spine;
cells 15-20, in diameter, 30-60, long including spines.
Euplankter; rare but found in several lakes. Wis.
CERASTERIAS Reinsch 1867, p: 68
Unicellular, free-floating, triangular or pyramidal, the angles
extended into long, tapering processes, the bases of which comprise
the body of the cell; processes all in one plane or in more than one;
chloroplast parietal, without a pyrenoid.
This genus should be compared with Tetraédron, from which it
is separated only on relative size of the cell body. In Tetraédron
the main part of the cell is evident, and it may have spines or
processes at the angles. In Cerasterias the body of the cell is
practically non-existent, being only the bases of the cell lobes.
C. irregulare G. M. Smith is to be expected in this area, but in our
collections only the European species, C. staurastroides West &
West, has been found. It is sometimes listed as Tetraédron stauras-
troides (W. West) Wille.
Cerasterias staurastroides West & West 1895b, p. 268 (fa. )
Pl. 56, Fig. 8; Pl. 61, Figs. 19, 20
Cells tetragonal, the body narrow and gradually extended into
4 long, slightly tapering processes which have 2 or 4 teeth-like
spines (in our specimens) at the apices; the wall of the processes
covered with sharply pointed granules arranged in transverse series;
body of the cell 10, in diameter; greatest dimension, including
processes, 36.5p.
Our specimens differ from the typical in having the processes
tipped with short teeth. The apices are described as rounded by
Brunnthaler (1915, p. 159).
Plankter; rare. Wis.
POLYEDRIOPSIS Schmidle 1900a, p. 17
Unicellular, free-floating, tetragonal or pyramidal, the angles
truncately rounded and furnished with a tuft of 3-10 long, tapering
[ 271 ]
setae; sides concave, or in some slightly convex; chloroplast a
parietal plate covering most of the cell wall, or more massive in
old cells, with 1 pyrenoid.
Polyedriopsis spinulosa Schmidle 1900a, p. 17
Pl. 62, Figs. 2,3
Characteristics as described for the genus; cells 12-25 in diameter;
setae 40y long.
Rare; in plankton. Wis.
FAMILY SCENEDESMACEAE
In this family the cells are adjoined to form definite patterns
and colonial aggregates of regular shape. This arrangement is
determined by the autospores which, when cut out of the parent
protoplast, become definitely related and oriented to one another
to form autocolonies in which there are always multiples of 2. These
colonies upon being liberated increase in size to form the mature
lant.
There is a great variety of cell shapes (oblong, fusiform, spherical,
triangular, trapezoidal) and arrangement. The colony may be a
linear series, a flat plate, a trapezoidal aggregate, or a cluster of
radiating fusiform individuals.
This family differs from the preceding one (Oocystaceae) in
that colonies are formed by the definite adjoining of cells in a
regular pattern.
Key to the Genera
1. Cells ovoid, fusiform, crescent-shaped, or oblong, arranged with
their long axes parallel to form a single
or double senies\inel yplaueee = ed ee Scenedesmus
(See S. acyminatus, with cells in a curved series. )
1. Cells of different shape, or otherwise arranged ____------------------______-- 2
2. Cells fusiform or cylindrical, with long axes
parallel; quadrately arranged in 2 tiers Tetradesmus
2. Cells arranged otherwise-__._.__—-_--_------_---—-—-_-------- 8
3. Cells spherical, forming pyramidal and multiple
colonies of 4; cells bearing long spines______-------------------------- Micractinium
3. Cells not spherical, without spines or with but very short ones______- 4
4. Cells with only their poles adjoined, extending in several planes 6
(See Scenedesmus Bernardii, however. )
4. Cells, often in 4’s, forming a flat coenobium with cells adjoined
or not adjoined along their walls_________-_-----------—-----------------------—--— 5
5. Cells bearing spines. -____--_______- Tetrastrum
5. Cells without spines_______________---_____-______--__ Crucigenia
6. Cells cylindrical or fusiform _-_------------—---—--—--—-—-------------—-- Actinastrum
6. Cells sausage-shaped, or crescent-shaped —_.._-—---_----------- Tetrallantos
[ 272 }
SCENEDESMUS Meyen 1829, p.774
Colony of 2—4-8-32 ovoid, fusiform, crescent-shaped, or oblong
cells lying side by side in a single series, or in a double row with the
cells alternating; cell walls smooth or with spines, teeth, and ridges;
chloroplast a parietal plate covering most of the cell wall and often
showing a median lateral notch; 1 pyrenoid.
This genus contains some species which are perhaps more widely
distributed than any other fresh-water algae. Whereas a few are
commonly found as euplankters, especially those which bear spines,
most forms occur in tychoplankton. In favorable habitats one or
two species may completely dominate the flora, and often a small
artificial pool or an aquarium will be densely colored by their
tremendous numbers. See Chodat (1926) and Smith (1916a) on
the taxonomy and pure-culture studies of the genus.
Key to the Species
1. Wall smooth, without decorations such as spines, teeth, or nid fesse 2
1. Wall decorated with spines, teeth, or 1G eS ean Pear Seen tate Ra Sy il
ugh Miesgotvcelisrroundedes25em See ere Sd ad 3
2. Poles of cells narrowed, sometimes Polite ss 29 A 2 a he Sa 4
3. Cells definitely arranged in a double series... S. arcuatus
3. Cells arranged in a single series (sometimes in
aniudefinitelyaltemating Series)! 122) Vee eh S. bijuga
deaGellstallemnivonerplarie sheet On cielo Bete Vk ah aS 5
A Ce usmotallsin: one wplaie 2a) tb oe Ay ee Pe ee. ee 6
5. Cells fusiform, all the same shape in the colony. S. obliquus
5. Cells both fusiform and crescent-shaped in the same colony_..S. dimorphus
6. Cells adjoined alternately at their poles
Guly, forming a\twasted chain! 102 8 ees ie S. Bernardii
6. Cells adjoined along their longitudinal walls,
POrnaae ATCInG C= eer see ke ees meee oe ef DIS S. acuminatus
7. Cells with longitudinal ridges only, no teeth S. acutiformis
7. Cells with teeth, spines, and sometimes ridges also. 8
6: Gellsiwithsteethvorispinesyomly.< 28.07 9
&~ Cells with both teeth(or'spimes) and ridges= 9 18
9. Wall uniformly beset with very short teeth S. hystrix
9. Wall not beset with uniformly distributed teeth. 10
10. Cell wall with a longitudinal row of small
teeth>"as) welllasitecthvat the poles. ets S. serratus
10. Cell wall without a longitudinal row of teeth. ia
11. Cells with only a single, blunt, papilla-like
Spine ‘atythesapexvoneach celle. ee en S. incrassatulus
I... Gellsi with long, shanp testh or spines 12
12. Cells with 2 or 3 sharp teeth at the poles S. denticulatus
12. Cells with long spines, not teeth alone at the poles 13
13. Spines on only the outer cells of the series 14
13. Spines on both the outer and inner cells of the series... 16
[ 273 ]
14. Cells cylindrical or ovate, adjoined along
theirs errtine wl ate Tall val Sess escent ee na eR S. quadricauda
14. Cells naviculoid or subquadrate, not adjoined
along theis entixe! lateral: wallsi22 3 "es ee ee ee 15
15. Cells naviculoid, attached along the middle
Pe oye tdaveive keene Seb S. opoliensis
15. Cells subquadrate, lateral walls of inner cells
concave; attached ionly, at the comers a eee S. perforatus
16. Spines arising from both the poles and from face of cell S. abundans
16) Spines) arising from: the polesjofthe cell only: = ee i7/
172 Gells mavieuloid, narrowed ‘at the poles === =a. S. opoliensis
17. Cells oblong or cylindrical, the ends rounded —_______________ S. longus
18. Outer cells only bearing a long spine at each pole—-__-____ S. armatus
18. All cells bearing 2 or 4 sharp teeth at the poles —______________ S. brasiliensis
Scenedesmus abundans (Kirch.) Chodat 1918, p. 77
Pl. 61, Fig. 21
Cells oblong or ovate, in a linear series of 4, the terminal cells
with 1 or 2 polar spines and 2 spines on the lateral wall, the inner
cells with a spine at each pole; cells 4-7 in diameter, 7-12, long.
Plankter; found in several lakes; common. Mich., Wis.
Scenedesmus abundans var. asymmetrica (Schroed. )
G. M. Smith 1916a, p. 468
Pl. 61, Figs. 22, 23
Cells oblong-ellipsoid, outer cells with a spine at each pole and
all cells with a median spine arising perpendicularly from the lateral
walls; cells 2.5-4.5 in diameter, 12-15y long.
Plankter; uncommon. Wis.
Scenedesmus abundans var. brevicauda G. M. Smith 1916a, p. 468
PIG, Figs: 26, 27; Pl62, Fig
Cells smaller than the typical; spines shorter and fewer; cells
2.5-5u in diameter, 5-8» long; spines 1.5-3.5p long.
Wis.
Scenedesmus abundans var. longicauda G. M. Smith 1916a, p. 467
Pl. 62, Figs. 4,5
Cells smaller than the typical, with relatively longer spines; cells
3-6, in diameter, 7-9, long; spines 6-10, long.
Wis.
Scenedesmus abundans var. spicatus (West & West )
G. M. Smith 1916a, p. 468
Colony composed of 2-4 cells, the outer cells with a longitudinal
series of 5-7 spines, the inner cells with 1-2 spines at the apices
only; cells 4» in diameter, 7.5-9p long.
Wis.
[ 274 ]
Scenedesmus acuminatus (Lag.) Chodat 1902, p. 211
Pl. 62, Fig. 16
Cells arranged in a curved series of 4 (rarely 8) cells strongly
lunate, with sharply pointed apices, the convex walls adjoined in-
wardly, the concave faces directed outward; cells 3-7 in diameter,
30-40, long.
Plankter; rare. Mich., Wis.
Scenedesmus acuminatus var. minor G. M. Smith 1916a, p- 436
A small variety; cells 3.5-6. in diameter, 18-28, between the
apices.
Wis.
Scenedesmus acuminatus var. tetradesmoides
G. M. Smith 1916a, p. 439
A variety with cells less strongly curved than in the typical;
2.5-4 in diameter, 11-15, long; curvature of colony varying from
slight to acute.
Wis.
Scenedesmus acutiformis Schroeder 1897a, p. 45
Pl. 62, Figs. 6, 7
Cells arranged in a single series of 4 (2 to 8), fusiform-elliptic,
with poles sharply pointed; inner cells with a single facial longitu-
dinal ridge; outer cells with 2-4 longitudinal ridges; cells 7-8» in
diameter, (16)-22.5y long.
Plankter; found in several lakes and bogs; fairly common. Mich.,
Wis.
Scenedesmus arcuatus Lemmermann 1899a, p. 112
Pl. 62, Fig. 8
Cells arranged to form a curved (usually double) series of 4-16
oblong-ovate individuals with lateral walls in contact along 14to 14
their length; cell wall without spines or teeth; poles of the cell
broadly rounded; cells 4-8-(9) in diameter, 10-15-(17), long.
Swamps, lakes. Mich., Wis.
Scenedesmus arcuatus var. capitatus G. M. Smith 1918, p. 637
Pl. 62, Fig. 9
Similar to the typical form but with a short, blunt-pointed pro-
jection at each pole of the cells; cells 5-11, in diameter, 11-23, long.
Wis.
Scenedesmus arcuatus var. platydisca G. M. Smith 1916a, p. 451
Pl. 62, Figs. 10-12
Plant composed of 8 cells arranged in a flat, rather than a curved,
double series; cells oblong-elliptic, 4.5-7.54 in diameter, 8-17, long.
Mich., Wis.
[ 275 }
Scenedesmus armatus (Chod.) G. M. Smith 1916a, p. 460
Pl. 62, Figs. 13, 14
Plant composed of 2-8 cells arranged in a single, partially alter-
nating series, oblong-ellipsoid but with ends broadly rounded;
terminal cells with a single, long, usually curved or unevenly bent
spine at each pole; central cells with a median, incomplete longi-
tudinal ridge; cells 6-8 in diameter, 9-15, long.
Widely distributed and fairly common in a variety of lakes and
ponds. Mich., Wis.
Scenedesmus armatus var. Chodatii G. M. Smith 1916a, p. 461
A variety with more slender cells and with proportionately less
of the lateral walls in contact so that the notches between the poles
of adjacent cells are deeper; cells 4—5p in diameter, 11-15y long.
Wis.
Scenedesmus armatus var. major G. M. Smith 1920, p. 155
Pl. 62, Fig. 15; Pl. 68, Fig. 23
Cells larger than in the typical plant, 9» in diameter, 25p long;
spines longer, 15y.
Wis.
Scenedesmus armatus var. subalternans G. M. Smith 1916a, p. 461
Colony composed of pyriform cells, subalternately arranged in
two series; cells 3-5.5 in diameter, 9-12 long.
Wis.
Scenedesmus Bernardii G. M. Smith 1916a, p. 436
Pl. 63, Fig. 1
Colony composed of 2-8 fusiform, lunate, or sigmoid cells in a
single series, but with terminal cells at an angle to the plane of
arrangement of the inner cells; cells adjoined alternately by the
apex of one cell to the midregion of the next in series; wall without
spines or teeth; cells 3-6, in diameter, 8-17» long.
Mich., Wis.
Scenedesmus bijuga (Turp.) Lagerheim 1893, p. 158
Pl. 63, Figs. 2,7
Colony composed of 2-8 cells in a single (rarely alternate) flat
series; cells ovate or oblong, without teeth or spines; cells 4-8» in
diameter, 8-16, long.
Widely distributed; often appearing as a prominent component
of the littoral plankton. Mich., Wis.
[ 276 ]
Scenedesmus bijuga var. alternans (Reinsch) Hansgirg 1888, p. 114
Pl. 63, Figs. 3, 4
Cells ovate or elliptic, regularly arranged in 2 alternating series;
cells 4-8» in diameter, 7-16, long.
Widely distributed; common in the plankton of many lakes and
in the tychoplankton of ponds and swamps. Mich., Wis.
Scenedesmus bijuga var. flecuosus (Lemm.) Collins 1909, p. 168
A variety differing from the typical by having the cells arranged
in a single series only, as many as 32 in one colony; cells broader
than in the typical plant.
Wis.
Scenedesmus bijuga var. irregularis ( Wille)
G. M. Smith 1916a, p. 448
Cells very irregularly arranged, occurring either in alternate or
double series; 3.5—-6y in diameter, 7.5-10, long.
Wis.
Scenedesmus brasiliensis Bohlin 1897, p. 22
Pl. 63, Figs. 5,6
Colony composed of 2-8 subcylindric or ovate-ellipsoid cells
arranged in a single series; apices of cells with 1-4 short teeth and
with a longitudinal median ridge extending between the apices of
each cell; cells (3)-5-7p in diameter, 10-22» long.
Common in many lakes. Mich., Wis.
Scenedesmus denticulatus Lagerheim 1882, p. 61
Pl. 63, Figs. 10, 11
Colony composed of 4 or 8 ovate cells arranged in a single
series (rarely alternating); apices of cells with 1-4 short teeth;
free walls of cells smooth; cells 6-10» in diameter, 8—15y long.
Very common and almost always accompanying other species of
Scenedesmus. Mich., Wis.
Scenedesmus denticulatus var. linearis Hansgirg 1888, p. 268
Colony composed of 4 or 8 ovate cells arranged in a single,
straight series, poles of the cells rounded and furnished with 2
small teeth; cells 4—5y in diameter, up to 15y long.
Wis.
Scenedesmus dimorphus (Turp.) Kuetzing 1833, p. 608
Pl. 63, Figs. 8, 9
Colony composed of 4 or 8 fusiform cells arranged in a single
or alternating series; the inner cells with straight, sharp apices; the
art |
outer cells lunate, strongly curved, with acute apices; cells 3-6y in
diameter, 16-22, long.
Common and widely distributed in many lakes and bogs. Mich.,
Wis.
Scenedesmus hystrix Lagerheim 1882, p. 62
Pl. 63, Fig. 12
Colony composed of 2-4-8 oblong-cylindric cells arranged in
a single series; apices narrowly rounded; wall uniformly beset with
short, sharp spines; cells 3-5 in diameter, 8—18p long.
Rare; in plankton. Wis.
Scenedesmus incrassatulus Bohlin 1897, p. 24
Pl. 63, Fig. 14
Colony composed of (2)—4-8 fusiform, subacute cells, arranged
in either 1 or 2 series (alternating); median cells slightly curved;
outer cells definitely curved, with the free walls strongly concave;
apices of the cells with a nodular thickening; cells 5-8, in diameter,
17-24, long.
Typical plant not reported from our area.
Scenedesmus incrassatulus var. mononae G. M. Smith 1916a, p. 440
Pl. 63, Fig. 13
A variety differing from the typical by its smaller, more slender
cells, 4.4-5y in diameter, 11-12, long.
Wis.
Scenedesmus longus Meyen 1829, p. 774
Pl. 63, Figs. 15, 16
Colony composed of 2—4-8 oblong-cylindric cells arranged in a
single series; apices of both inner and outer cells with 1 or 2 sharp
spines which are longer on the outer cells; cells 4-6u in diameter,
8—12y long.
Rare in the plankton of several lakes. Mich., Wis.
Scenedesmus longus var. brevispina G. M. Smith 1916a, p. 471
A variety with more slender cells than the typical and with
shorter spines; cells 3-5, in diameter, 9-11p long.
Wis.
Scenedesmus longus var. ellipticus (West & West )
G. M. Smith 1916a, p. 472
Colony composed of 4 ellipsoid cells arranged in a single series;
outer cells bearing 2 outwardly curved spines, the inner cells with
a single spine; cells 5. in diameter, 12, long.
Wis.
[ 278 ]
Scenedesmus longus var. minutus G. M. Smith 1916a, p. 471
A small variety with short spines; cells 2-3, in diameter, 8y long;
spines 1.5-2, long.
is.
Scenedesmus longus var. Naegelii (de Bréb. )
G. M. Smith 1920, p. 156
Pl. 63, Fig. 24; Pl. 64, Fig. 1
Colony composed of 8 cylindrical cells arranged in a single series;
outer cells bearing a long, curved spine at each pole; inner cells
with a long spine at one pole only (rarely with no spines); cells
7-12, in diameter, 16-28, long.
Plankter; in several small lakes. Mich., Wis.
Scenedesmus obliquus (Turp.) Kuetzing 1833b, p. 609
Pl. 63, Fig. 17
Colony composed of 2-8 (usually 4 or 8) fusiform cells arranged
in a single series; apices of cells apiculate; wall smooth; cells 4.2-9n
in diameter, 14-18—( 21), long.
Rare in tychoplankton of a swamp; rare in many lakes. Mich., Wis.
Scenedesmus opoliensis P. Richter 1896, p.7
Pl. 63, Fig. 18
Colony composed of 2-4-8 naviculoid cells arranged in a single
series, with free walls of outer cells convex, the lateral adjoined
walls in contact along 1/3—2/3 of their length; apices of cells with
long spines (inner cells with a spine at one pole only, or some-
times without spines); cells 6—8» in diameter, 14—26, long.
Rare but widely distributed. Mich., Wis.
Scenedesmus opoliensis var. contacta Prescott 1944, p. 359
Pl. 63, Figs. 19, 20
Colony consisting of 4 naviculoid cells arranged in a single series,
adjoined along %4 of the length of their lateral walls; spines on
terminal cells either 1 or 2 at each pole, long and curved; spines on
apices of inner cells short and straight; cells 6-8, in diameter,
20-24 long.
Plankter; rare. Wis.
Scenedesmus perforatus Lemmermann 1904, p. 159
Pl. 46, Figs. 24, 25
Cells subrectangular with convex end walls and concave lateral
walls, thus forming biconvex intercellular spaces; end cells of the
[ 279 }
colony bearing a single long curved spine at each pole arising from
the corner of the cells, the outer lateral walls of the end cells
straight or umbonate; cells 3-3.5-(5) » in diameter, 10-13, long.
Mich.
Scenedesmus quadricauda (Turp.) de Brébisson in
de Brébisson & Godey 1835, p. 66
Pl. 64, Fig. 2
Colony consisting of 2-4-8 oblong-cylindric cells usually in 1
series (sometimes in 2 alternating series); outer cells with a long
curved spine at each pole; inner cells without spines or with mere
papillae at the apices; cells variable-in size, 3-18. in diameter,
9-35 long.
Common and widely distributed in a variety of habitats; one of
the most nearly ubiquitous algal species. Mich., Wis.
Scenedesmus quadricauda var. longispina (Chod. )
G. M. Smith 1916a, p. 480
Pl. 63, Fig. 22
A variety differing from the typical by the greater length of the
spines; cells 3.5-5y in diameter, 8-11 long; spines 7.5-10p long.
Plankter; in lakes. Mich., Wis.
Scenedesmus quadricauda var. maximus West & West 1895, p. 83
Pl. 64, Figs. 3, 4
A variety differing from the typical by the larger size of cells
and relatively longer spines; cells 9-11.5p in diameter, 27-36, long;
spines 20-30, long.
Plankter; in lakes; rare. Mich., Wis.
Scenedesmus quadricauda var. parvus G. M. Smith 1916a, p. 480
Pl. 64, Fig. 6
Colony composed of 2-16 cylindrical-ovate cells arranged in a
single series; outer cells with a long spine at each pole; inner cells
with spineless walls; cells 46.5, in diameter, 12-17, long.
Very common in many lakes and swamps. Wis.
Scenedesmus quadricauda var. quadrispina (Chod. )
G. M. Smith 1916a, p. 480
Pl. 63, Fig. 21
Colony composed of 4-8 ovate cells with short spines, usually
strongly recurved; cells 47.4, in diameter, 9-16p long; spines about
Su long.
fete but widely distributed in many lakes and ponds. Mich., Wis.
[ 280 ]
Scenedesmus quadricauda var. Westii G. M. Smith 1916a, p. 480
Pl. 64, Figs.7, 9
Colony composed of 4-8 ovate cells with broadly rounded apices;
cells 5-8. in diameter, 10-18—(22), long; spines relatively short,
often strongly reflexed.
Rare, but found in the plankton of a great variety of lakes, ponds,
and swampy habitats. Mich., Wis.
Scenedesmus serratus (Corda) Bohlin 1901, p. 44
Pl. 64, Fig. 8
Colony composed of 4 oblong-ovate cells arranged in a single
series; the outer cells with one, the inner cells with two longitudinal
rows of small teeth; apices of all cells bearing 3-4 small teeth; cells
4.5-7y in diameter, 15-20, long.
Plankter; in several lakes. Wis.
ACTINASTRUM Lagerheim 1882, p. 70
Colonial, planktonic, composed of 4-16 truncate-fusiform or
basidia-like cells, sometimes cigar-shaped with subacute poles,
radiating in all planes from a common center, not inclosed by a
colonial envelope; chloroplast a parietal, elongate plate covering
about 14 of the wall in circumference and nearly as long as the
cell; 1 pyrenoid present.
Key to the Species
Cells 7-10 times as long as wide, about as wide at the poles
asjnithe median part of the celle. A. gracilimum
Cells 3-6 times as long as wide; median part of the
cell about twice as wide as the poles__.____________»____ A. Hantzschii
Actinastrum gracilimum G. M. Smith 1916, p. 480
Pl. 64, Fig. 5
Cells cylindrical, with very slightly narrowed to abruptly truncate
poles, forming colonies of individuals with the long axes of the
cells radiating in all planes from a common center; cells 1.7—3p in
diameter, 14-21 long; colonies 30—45y in diameter.
Rare; in the plankton of several lakes. Mich., Wis.
Actinastrum Hantzschii Lagerheim 1882, p. 70
Pl. 64, Figs. 10, 11
Cells spindle-shaped or cylindrical, narrowed toward the apices,
arranged in simple or compound colonies of 4 or 8 with the long
[ 281 ]
axes of the cells radiating from a common center; chloroplast a
parietal plate, with 1 pyrenoid; cells 3-5.6 in diameter, 12-22, long.
Common in plankton. Mich., Wis.
Actinastrum Hantzschii var. elongatum G. M. Smith 1918, p. 636
Pl. 65, Fig. 2
Cells cylindrical, very slightly if at all narrowed toward the apices,
larger than in the typical plant; cells 4-5p in diameter, 30-35, long.
Rare; in plankton. Wis.
Actinastrum Hantzschii var. fluviatile Schroeder 1899, p. 20
Pl. 65, Fig. 1
A variety differing from the typical in that the cells are sharply
pointed; cells 3.3-3.5y in diameter, 39-42, long.
Rare in a swamp. Wis.
TETRADESMUS G. M. Smith 1918, p.76
A 4-celled, free-floating colony; cells fusiform, or cylindrical,
arranged in 2 planes with their longitudinal axes parallel, the
adjoined walls straight, in contact throughout most of their length,
the outer free wall straight or concave, the poles of the cell directed
away from the center of the colony; cells in vertical view spherical,
arranged in a quadrangle; chloroplast a parietal plate with 1
pyrenoid.
Key to the Species
Cells fusiform, attached throughout the length
Ofutheinalatenal wwralllseescee cies ales ne Nera e eye ose cere T. wisconsinense
Cells crescent-shaped, cylindrical, attached along only a
portion of their lateral walls___________________ T. Smithii
Tetradesmus Smithii Prescott 1944, p. 360
Pl. 64, Figs. 15-17
Cells slightly arcuate or crescent-shaped or subcylindrical, slightly
narrowed toward the poles which are broadly rounded, in groups
of 4 with their long axes parallel and with the convex walls adjoined
in the mid-region only; outer free walls concave or nearly straight;
cells in end view spherical, arranged in a quadrangle; chloroplast
a parietal plate; cells 3.7-4y in diameter, 27-29, long.
This species should be compared with Quadrigula spp. The cells
are not so straight as in that genus although they have about the
same proportions and are arranged in bundles of 4. Also Tetradesmus
Smithii, unlike Quadrigula, has no gelatinous investment inclosing
the quartets of cells.
Rare; in plankton. Wis.
[ 282 ]
Tetradesmus wisconsinense G. M Smith 1913, p. 76
Pl. 64, Figs. 12-14
Cells fusiform arranged with their long axes parallel; cells ad-
joined throughout the length of their lateral walls; outer free walls
concave; poles of the cell narrowed and directed away from the
center of the colony; in end view spherical, the cells arranged in
a quadrangle; cells 4—-6u in diameter, 12-14.5y long.
Rare; in the plankton of lakes. Wis.
CRUCIGENIA Morren 1830, pp. 404, 415
Colony free-floating, consisting of a plate of 48-16 trapezoid or
rhomboid cells lying in one plane about a small or large central
space; chloroplast a parietal plate with 1 pyrenoid in each cell;
colony inclosed by a thin, inconspicuous gelatinous envelope which
often causes the families to adhere to one another and to form
colonial complexes.
Key to the Species
1. Opening at the center of the colony large, approximately
equal: tothe, greatest dimension of ‘the cells-2 te 2
1. Opening at center of the colony small, less than
theporeatest dimiensionzeta tic. cells acter 8.2 2s ee Al seal rove eee 8
2. Cells nearly hemispherical, old mother cell
By AAS DES ASLS TE oe eeatooe e E El 8 SO a C. Lauterbornii
2. Cells trapezoidal; outer free walls slightly convex; old
mother cell walls not persistent C. fenestrata
3. Cells triangular; opening at the center of the colony very small... 4
sate GerISH Ona Le | OT pO hy ei oKnal ioe sets PES ES Esa LE Cee hen he 5
Ap Outer tree walls; Straig@hibe fs aatte eld era 2k C. tetrapedia
Are Otter eine wWallsnCOMVeN een o et Fa ee ee C. quadrata
9. Cells’ with an apiculation at the free pole C. apiculata
oeCellsiwithouk au iapiculationm: 0s ot yak 28D ee a ee ee 6
6. Cells abruptly truncated at the free poles, the
walls ‘thickened atthe apex 51828 We ee C. truncata
6. Cells not truncated, the wall not thickened at the apex_________________ il
7. Cells somewhat reniform, the outer free walls concave;
cells “always: quadrately arranged= 25.2) at a eek C. crucifera
eg CNIS OV ALC resins te oe NL ke we od SS 8
8. Cells regularly arranged in quartets or in multiples
OL Quartets 15 Oj longa ees eee ee eee Ee C. rectangularis
8. Cells irregularly arranged within the colony,
SOnge amt S.18 14 ce Meouier 2 tO ea a ee ee to C. irregularis
Crucigenia apiculata (Lemm.) Schmidle 1901, p. 234
Pl. 65, Fig. 3
Colony composed of 4 ovate, rhomboidal or somewhat triangular
cells arranged about a 4-sided opening, with 1 short, cone-shaped
apiculation on the cell wall at the free outer apex, and one on the
[ 283 ]
lateral walls where the cells adjoin at their ‘bases’; cells 3-7 in
diameter, 5-10, long; colony 6-12.51 wide, 9-18, long.
Euplankter. Mich., Wis.
Crucigenia crucifera (Wolle) Collins 1909, p. 170
Pl. 65, Fig. 4
Colony consisting of 4-sided cells arranged about a central square
opening, the outer free walls longer and concave, the outer free
angles of the cells rounded, the lateral adjoined walls straight and
converging inward where they adjoin other cells, the inner walls
about the central opening forming a short, straight side; multiple
colonies resulting from the adherence of quartets of cells by per-
sisting mother cell walls; cells 3.5-5yu in diameter, 5-7 long; colony
9-11, wide, 14-16, long.
Plankter. Mich., Wis.
Crucigenia fenestrata Schmidle 1901, p. 234
Pl. 65, Fig. 5
Colony consisting of 4 trapezoidal cells arranged about a square
opening, the outer free wall longest and convex, the free angles
sharply rounded; lateral and inner (the shortest) walls straight;
cells 3-5 in diameter, 5-13, long; colony 8-14y wide, frequently
adjoined in closely arranged association to form multiple colonies.
Rare; found in the euplankton of a few lakes. Mich., Wis.
Crucigenia irregularis Wille 1898, p. 302
Pl. 65, Fig. 6
Colony free-floating, consisting of 4, or multiples of 4 ovate cells
not definitely arranged about a central space as in other species of
the genus and not in quadrangular formation, with both lateral
and apical walls in contact; chloroplasts broad parietal plates or
discs, as many as 4 in a cell; pyrenoid sometimes absent; cells 5-9
in diameter, 8-14» long.
This is the most frequently seeu species of Crucigenia in our
collections. It should be compared with C. rectangularis (Naeg. )
Gay which also has ovate cells but in which the cells have a
regular arrangement about a central space.
Common in a large number of lakes and ponds. Mich., Wis.
Crucigenia Lauterbornii Schmidle 1901, p. 234
Pl. 65, Fig. 11
Colony free-floating, consisting of 4 subspherical cells arranged
in 2 opposite pairs about a large square space bounded by the flat,
[ 284 ]
inner walls of the cells; cells in contact only at their inner corners;
1 chloroplast, parietal along the outer convex wall; pyrenoid present;
cells 4.5-9 in diameter, 8-15, long; quartets of cells adjoined in
multiples by remains of old mother cell walls.
Rare; in the plankton of several lakes. Wis.
Crucigenia quadrata Morren 1830, pp. 415, 426
Pl. 65, Fig.10
Colony free-floating, consisting of a circular plate of 4 triangular
cells, cruciately arranged about a small central space, the outer free
wall of the cells broadly convex, the lateral walls straight, adjoined
throughout their length with neighboring cells and converging to-
ward the center of the colony; walls sometimes with knob-like
projections; chloroplasts parietal discs, as many as 4 in a cell;
pyrenoids not always present; cells 2.5-6. in diameter, 3.7, long;
multiple quadrate colonies formed by the close arrangement of
component quartets.
Smith (1920, p. 147) considers Staurogenia multiseta var. punctata
Schmidle and Crucigenia triangularis (Chod.) Schmidle to be
synonymous with this species.
Plankter; found in a large number of lakes in northern counties.
Mich., Wis.
Crucigenia rectangularis (A. Braun) Gay 1891, p. 100
Pl. 65, Figs. 7,8
Colony free-floating, consisting of ovate or oblong cells, very
regularly arranged about a rectangular central space in 2 pairs,
with the apices adjoining; chloroplasts 1-4, parietal discs, with a
pyrenoid in each; cells 4-7 in diameter, 5-10,» long.
This species should be compared with C. irregularis Wille.
Common in both eu- and tychoplankton of a large number of
lakes. Mich., Wis.
Crucigenia tetrapedia (Kirch.) West & West 1902, p. 62
PliGa;, Hig. 9; Fl..66, Fig.)
Colony free-floating, consisting of 4 triangular cells cruciately
arranged about a minute central space; outer free wall and lateral
walls straight, the angles acutely rounded; chloroplast a parietal
plate with a single pyrenoid; cells 4.5-9 in diameter, frequently
forming a rectangular plate of 16 cells (4 quartets).
Common in a small lake. Wis.
[ 285 ]
Crucigenia truncata G. M. Smith 1920, p. 146
Pl. 66, Fig.2
Colony free-floating, consisting of 4 ovate cells arranged about a
central, rectangular space, with lateral walls of each pair of cells
adjoining and with apical walls in contact at the corners, the outer
free walls thick and truncate, straight; chloroplasts 1-4, parietal
discs; pyrenoids absent; quartets of cells adjoined to form compound
colonies by the adherence of old mother cell walls; cells 4-6, in
diameter; colonies up to 50 wide, 75y long.
Rare in the plankton of several lakes. Wis.
TETRASTRUM Chodat 1895a, p. 114
Plant a free-floating colony of 4 triangular, cruciately arranged
cells, inner faces straight and adjoined to form a rectangular plate,
outer free wall convex and beset with 3 or 4 short setae; colony
inclosed by a thin gelatinous matrix; chloroplasts 1-4 in each cell,
parietal discs with pyrenoids sometimes absent.
This plant should be compared with Crucigenia, a genus with
which it has much in common. Some species of Crucigenia in the
past have been assigned to Tetrastrum. The latter genus is character-
ized by the setae, by its possession of a definite colonial investment,
and by its failure to form compound colonies.
Key to the Species
Outer faces of cells with short, knob-like projections —.______. T. punctatum
Outer faces of cells with long, hair-like setae _________- T. staurogeniaeforme
Tetrastrum punctatum (Schmidle) Ahlstrom & Tiffany 1934, p. 504
Colony of 4 angular, or somewhat triangular cells, broadly convex
on their outer free walls, arranged about a very small central space;
walls furnished with several coarse knob-like projections; chloro-
plast parietal and plate-like, with a single pyrenoid; cells 8-12» in
diameter.
Uncommon; in plankton. Mich., Wis.
Tetrastrum staurogeniaeforme (Schroeder )
Lemmermann 1900d, p. 95
Pl'66; Fig.* 3
A colony of 4 triangular cells, cruciately arranged about a small
rectangular space; lateral margins of the cells straight and adjoined,
the outer free walls convex and furnished with as many as 6 fine,
hair-like setae; chloroplasts 1-4 parietal discs, sometimes containing
[ 286 ]
pyrenoids; cells 3-6, in diameter; colony 7-15» wide without setae,
which are 4-8, long.
This species should be compared with Crucigenia quadrata.
Rare in the plankton of several lakes. Mich., Wis.
TETRALLANTOS Teiling 1916, p. 62
A colony of 4 crescent-shaped or sausage-shaped cells which are
bluntly rounded at their apices and inclosed by a colonial mucilage,
with clusters of daughter cells often held in approximation by old
mother cell wall fragments; cells in 2 pairs and in 2 planes, 1 pair
facing each other and in contact at their poles, the other pair in a
longitudinal plane vertical to these and so arranged that each
member has 1 pole at the point of contact of the poles of the other
pair; chloroplast a parietal plate with 1 pyrenoid.
Tetrallantos Lagerheimii Teiling 1916, p. 62
Pl. 66, Figs. 4-6
Characteristics as described for the genus; cells 4-8» in diameter,
10-13 long.
This rather unusual plant is rare in the United States, apparently
having been found only in Wisconsin, Massachusetts, and Mississippi.
Rare; in the plankton of soft water lakes and small ponds. Wis.
MICRACTINIUM Fresenius 1858, p. 236
Free-floating, one-celled or in colonies of tetrahedrally or pyramid-
ally arranged spherical or ovate cells (sometimes in 1 plane); walls
beset with 1-7 long, needle-like setae; 1 parietal, cup-shaped
chloroplast containing a single pyrenoid. Korschikov (1937) reports
observation of sexual reproduction in this genus.
Key to the Species
Gellsspherical; setae/20=S5p longa. 1 hee ee M. pusillum
Gellsiovatesssetac (2040 n long oe fe te Ta kN M. quadrisetum
Micractinium pusillum Fresenius 1858, p. 236
Pl. 66, Fig. 8
A free-floating colony of 4-16 spherical cells arranged in a
pyramid or in a square, groups of 4 in association with other
similar groups; free walls beset with 1-5 finely tapering setae;
chloroplast a parietal cup with 1 pyrenoid; cells 3-7 in diameter
without setae; setae 20-35, long.
Rare in the plankton of many lakes, mostly soft water habitats.
Mich., Wis.
[ 287 ]
Micractinium pusillum var. elegans G. M. Smith 1918, p. 631
Pl. 66, Fig. 7
A variety differing from the typical by having more numerous
and longer setae on the free walls of the cells; setae 5-7 in
number.
Rare; in plankton. Wis.
Micractinium quadrisetum (Lemm.) G. M. Smith 1916, p. 479
Pl. 68, Fig. 1
A free-floating colony of 4 ovate cells, adjoined to other groups
of 4 about a central rectangular space; wall with 1-4 very long,
finely tapering setae; chloroplast a parietal cup with 1 pyrenoid;
cells 4~-7p in diameter, 8-10, long; setae 23-40, long.
Rare; in the plankton of lakes. Mich., Wis.
ORDER SIPHONALES
In this order the thallus is a coenocytic tube, more or less branched
and usually showing a basal-distal differentiation. In marine forms
the thallus becomes very elaborate and complex; in the fresh-water
genera the vegetative thallus is simplified, although sexual repro-
duction is of an advanced type. There are no cross walls except where
sex organs or zoospores are cut off, although in Dichotomosiphon
there are frequent constrictions of the filament. There are numerous
ovate chloroplasts peripherally arranged in a layer of cytoplasm
along the wall, the center of the tube being vacuolate. There are
no pyrenoids, but starch is stored in Dichotomosiphon, and either
starch or oil may accumulate in Phyllosiphon and Vaucheria.*
Asexual reproduction is accomplished by zoospores or aplano-
spores. In sexual reproduction a high type of heterogamy is involved.
Enlarged oogonia, each with a single egg, are cut off by a wall
from the vegetative filament, usually near tubular antheridia which
produce large numbers of small biflagellate antherozoids. Fertiliza-
tion is effected through a terminal pore in the wall of the oogonium.
Key to the Families
Plants: endophytic. = 25.23 oe Se ay eet PHYLLOSIPHONACEAE
Plants free-living, either aquatic or subaerial VAUCHERIACEA®
FAMILY PHYLLOSIPHONACEAE
In this family the thallus is a much contorted tubular or vesicular
coenocyte which is either endozoic or (in our specimens) endophytic.
The plants inhabit the tissues of the Araceae, especially in tropical
and subtropical climates. There is but a single genus in our region.
*Now considered a member of the Chrysophyta.
[ 288 ]
PHYLLOSIPHON Kihn 1878, p. 24
This genus is parasitic in the tissues of the common Jack-in-the-
pulpit, Arisaema triphyllum (L.) Schott. The thallus consists of a
much twisted and closely compacted coenocytic tubular filament
with numerous oval chloroplasts and nuclei. The alga brings about
the disintegration of the host tissues and a destruction of the
chlorophyll so that large yellow patches develop. Food reserve is
in the form of either starch or oil. The only known method of
reproduction is by the formation of numerous aplanospores in the
tube which, upon being liberated, generate new coenocytic filaments
directly.
Phyllosiphon Arisari Kiihn 1878, p. 24
Pl. 69, Figs. 1-3
Characters as described for the genus; tubes dichotomously
branched, ramifying among the tissues of the host plant and
producing discolored areas; tubes 25-35, in diameter, 60» in
diameter during aplanospore production.
On blades and stalks of Jack-in-the-pulpit. Wis. (Swingle).
FAMILY VAUCHERIACEAE
Thallus long, much-branched, coenocytic tubes, sometimes pos-
sessing horizontal, downwardly directed, and vertical sex-organ-
bearing branches; chloroplasts numerous ovate or circular discs
embedded in a thin sheet of cytoplasm along the wall and about
large vacuolated central regions; pyrenoids lacking; reserve food
either oil or (less often) starch; reproduction by large multiflagellate
zoospores cut off from the ends of branches, by akinetes, or by
eggs and antherozoids, the gametes being produced in special sex
organs.
Key to the Genera
Regularly branched dichotomously and frequently
constricted; sex organs terminal -2) 2) 22s he Dichotomosiphon
Irregularly branched (sometimes sparsely so), not constricted;
sex organs lateral on the main filament
are (eearmimell Gyn leiwereall [sree Vaucheria
DICHOTOMOSIPHON Ernst 1902, p. 115
A multinucleate siphon, forming attached, felt-like masses on the
bottom of aquatic habitats, or rarely subaerial on damp soil; branch-
ing usually dichotomous with frequent constrictions at the base of
the branches; chloroplasts numerous small discs; pyrenoids lacking;
sexual reproduction oogamous, the sex organs borne in corymb-like
[ 289 ]
clusters at the ends of branches, the oogonia usually solitary glo-
bose; antheridia 1 to several in the cluster, formed at the tip of the
branch, becoming cut off by a septation, producing numerous motile
antherozoids. Large akinetes are common.
There is but one species in this genus.
Dichotomosiphon tuberosus (A. Braun) Ernst 1902, p. 115
Pl. 68, Figs. 6,7
Thallus a dichotomously branched tube with constrictions at the
base of the branches and with cross walls only where reproductive
structures are cut off; forming felt-like or cushion-like mats in the
silt of lake bottoms, and consisting of horizontal, downwardly
projecting, and erect, sex-organ-bearing branches; much enlarged,
elongate, subcylindric or globose akinetes frequent; sex organs
monoecious, located at the ends of strongly recurved branchlets
which form corymb-like clusters at the ends of vegetative filaments;
usually 1 spherical oogonium and several cylindrical antheridia
present; the oospores globular, becoming yellow at maturity and
easily seen with the unaided eye, oospore wall 3-layered; vegetative
siphons 50-100, in diameter; oogonia 250-300» in diameter; oospore
nearly the same size as the oogonium; antheridia 35—50u in diameter,
2-4 times the diameter in length.
This plant seems to grow only in lakes with a rich organic silt.
The thallus is often nearly buried in loose bottom deposits with
only the tips of vertical branches and the sex organs emerging. In
Wisconsin the plant has not been collected except from hard water
or eutrophic lakes. In Michigan it is common at depths up to 16
meters, but in such habitats it appears to reproduce only by akinetes,
sex organs being formed when the plant grows at 2 meters or less.
This may be related to water temperature. Like Vaucheria,
Dichotomosiphon forms a habitat for an association of microfauna
such as Rotifera, Cladocera, and many protozoa.
From several lakes, mostly from silty bottoms. Mich., Wis.
VAUCHERIA De Candolle 1805, p. 61*
Thallus subaerial or aquatic, a much and irregularly branched
siphonous coenocyte without cross walls except where reproductive
structures are cut off; filaments often compactly interwoven (espe-
cially in terrestrial species) to form a felt-like expansion, with
colorless rhizoids when attached, or forming entangled clots of
coarse threads when floating; branches arising laterally or dichoto-
mously, nearly as large as the main filament and tapering slightly
to broadly rounded tips; chloroplasts numerous ovate discs without
*See footnote, p. 288.
[ 290 ]
pyrenoids; asexual reproduction by large globose, multiflagellate
zoospores cut off singly at the ends of clavate branches; thick-walled
akinetes at the ends of branches, or in the tubes of some species;
sexual reproduction oogamous; oogonia globose or ovate, sessile, on
pedicels, or on long stalks, containing a single egg which may
completely fill the oogonium; antheridia on the same or different
filaments, clavate, cylindrical, or subcylindrical, coiled or straight,
usually reflexed with the terminal opening directed toward the
oogonium, borne near the oogonia or at the end of a series, producing
many biflagellate, ovoid to fusiform antherozoids; oospores with
thick walls, sometimes completely filling the oogonia and the same
shape.
Key to the Species
i Oogonia: 262 —289n 1m: diameter 2a ee V. Nicholsii
He @n Conta SAN er se kere cal AN eS ee Ae eats Tastee Lag 2
2. Oovonia sessile’ on the main filament = = 8 eee 3
2. Oogonia: on a ‘pedicel or ‘ona lateral ‘branch. 2 5
3. Oogonia obliquely ovate, large, up to 160 high
andy 220), dongee wall) Gut tinick: 2.) ithe ket V. pachydermum
83. Oogonia more nearly erect, smaller; wall not thick __--________ 4
4. Oogonia erect, the pore vertically directed _..__.________. V. orthocarpa
4, Oogonia with the pore directed obliquely upward_______________ V. sessilis
5. Oogonia on a short pedicel, sometimes nearly sessile_.____-_______-____ 6
5. Oogonia at the end of a long or short lateral branch, stalked. 10
6. Oospores not filling the oogonia; oogonia usually
In"pairss the pores directed oppositely. © ss Te V. aversa
6. Oospores filling the oogonia; arranged otherwise —.______-__-__-__ vi
7. Pedicel very short, scarcely evident; oogonia
broadly ovate, the pore nearly erect _____--..--_-----—-_________.--. V. sessilis
7. Pedicel evident; oogonia narrowly ovate or ellipsoid,
the pore oblique or more nearly horizontal -_.__.__________----_-_---------------- 8
8. Oogonia in pairs, or several on a short pedicel,
thewantheridiumimbebweensa ees = = sue eek eee ee ie V. geminata
8. Oogonia arising singly, near the antheridium________________ 9
9. Oogonia 80-150. in diameter, the pore directed
horizontally or obliquely downward © __--------------- *V. ornithocephala
9. Oogonia 60-65. in diameter; pore directed obliquely upward_V. polysperma
10. Oogonia 2 to several on the end of a lateral branch
arialllimeter Or mnone’ Int Wen cthizce te Sek snot ot ee er eke V. longipes
10: Oogonia solitary, ona. much) shorter branch 2-2 pe 11
11. Oogonia 60-103, in diameter, 85-211, long, without a pedicel
from the branch, arising near the base of the antheridia _______ V. terrestris
11. Oogonia averaging smaller, 60-75 in diameter, 75-90 long, with
a pedicel, placing it well above the associated antheridium —___- V. hamata
Vaucheria aversa Hassall 1843, p. 429
Pl. 66, Figs. 9, 10
Coarse filaments, freely branched and readily collapsing upon
being handled, 65-100» in diameter; oogonia usually in pairs or
[ 291 ]
several in a series on very short pedicels, mostly sessile, ovoid to
subglobose, opening by an oblique pore in a narrow beak which
faces in an opposite direction from the neighboring oogonium,
100-125, in diameter, 180-250, long; antheridia subcylindric, strong-
ly recurved, one on each side of a pair or series of oogonia; oospores
globose, with a 3-layered membrane, 80-120, in diameter, not filling
the oogonium.
Forming a soft, felt-like mat in spring seeps and on moist shady
banks of streams, etc. Wis.
Vaucheria geminata (Vauch.) De Candolle 1805, p. 62
Fl 68, Pigs: 223
Aquatic or on very moist soil; filaments coarse and freely branched,
80-100 in diameter; oogonia in pairs, ovate to subglobose, borne
laterally near the end of a short stipitate branch of the main axis,
with 1 antheridium circinate or strongly reflected; oogonia with
pores directed vertically, 60-80, in diameter, 70-90 long; oospores
with thick, 3-layered membranes, completely filling and the same
shape as the oogonia.
Forming floating, tangled mats in marshes and cut-oi ; from lakes
protected from wave action; in ditches of shallow water Mich., Wis.
Vaucheria geminata var. depressa Transeau 197, .228
A variety differing from the typical by having the pedicels of
the oogonia longer than in the typical, arising from a saort lateral
branch and curved so that the oogonia are in contact with the
main filament.
Mich.
Vaucheria hamata (Vauch.) De Candolle 1805, p. 63
Filaments rather slender; monoecious; oogonia solitary, or rarely
2 together, ovate to somewhat lunate, with the inner or lower margin
somewhat concave, borne on a pedicel at the end of a lateral branch
from the main axis, 60-75, in diameter, 75-90, long; antheridium
tubular, circinate, arising from near the base of the oogonium
pedicel; oospore with a 4-layered membrane, completely filling the
oogonium, containing a dark granular spot.
Floating, tangled mats in quiet water. Mich., Wis.
Vaucheria longipes Collins 1907, p. 201
Pl. 67, Fig. 5
Filaments rather coarse, 80-90» in diameter; monoecious; sex
organs on a long (1-4 mm.) lateral branch, 30-40, in diameter; the
[ 292 ]
antheridium distinctly circinate, terminal on the branch; oogonia
usually 3 (2-4), ovoid, somewhat oblique on rather long stalks
(up to 1500.) arising from just below the antheridium, 35-40, in
diameter, 70-85, long.
In pooled streams and quiet water of lakes. Wis.
Vaucheria Nicholsii Brown 1937, p. 283
Pl. 67, Fig. 10
Filaments very coarse, 112-120, in diameter; monoecious; oogonia
globose, sessile, the opening vertical, 262-289, in diameter; oospore
the same shape as and filling the oogonium (except the beak),
yellow-brown; antheridia sessile, arising from all sides of the main
filament near the oogonium and recurved so as to lie parallel with
the filament and opening toward the oogonium, 39-50p wide,
115-123, long.
Shore of Douglas Lake, Michigan.
Vaucheria orthocarpa Reinsch 1887, p. 191
BW6(, Hig
Filaments slender to moderately coarse, 77-110» in diameter;
monoecious; oogonia sessile, ovoid, erect with the opening vertical;
oospore ovate, completely filling the oogonium, the wall thick,
50-65 in diameter, 65-90» long; antheridia sessile, arising near
the oogonia, distinctly coiled, with the opening directed toward
the oogonium.
Mich.
Vaucheria pachyderma Walz 1866, p. 146
Pl. 67, Fig. 2
Filaments variable, slender or stout, 40-123 in diameter; monoe-
cious; oogonia mostly solitary, globular or transversely ellipsoid,
the opening horizontal, or downwardly oblique, the wall thick, up
to 6u, with discolored spots, 69-160» high, 69-220, long; oospore
filling the oogonium, 145, in diameter, 180, long, with a thick
wall; antheridium erect beside the oogonium, hooked at the apex.
Mich.
Vaucheria polysperma Hassall 1843, Pl. 6, Fig. 6
Pl. 67, Fig. 13
Filaments very slender, 15-33» in diameter; monoecious; oogonia
in a series of 3-5, each on a short pedicel, ovate, opening upwardly
oblique, 60-65, in diameter; oospores globose, filling the oogonium
in width only, 44-60.5 in diameter; antheridia cylindrical, sessile
on a short pedicel, strongly reflexed and opening toward the oogonia.
Mich.
[ 293 ]
Vaucheria sessilis (Vauch.) De Candolle 1805, p. 63
PIGS) Higa5
Aquatic or terrestrial; filaments somewhat slender, 50-58» in
diameter, with irregular branching; monoecious; oogonia usually
in pairs, ovoid to subglobose with the pore in a short beak and
directed obliquely upward, 70-85» in diameter, as much as 100p
long; antheridia on a short pedicel between 2 oogonia, either
straight or circinate, but usually with the opening directed toward
the pore of an oogonium, about 25p in diameter; oospore with a
3-layered membrane, filling the oogonium.
A common species but infrequently found in our collections;
forming a felt-like mat on submerged rocks and on sandy bottoms
of springs; on rocky outcrops where there is trickling water. Mich.,
Wis.
Vaucheria sessilis fa. clavata (Klebs) Heering 1921, p. 88
Pl. 67, Figs. 3, 4
Filaments stouter than in the typical, 77-110, in diameter; oogonia
broadly ovate with the beak directed vertically; oospore 49.5-66.5p
in diameter, 66-88.5, long.
Mich.
Vaucheria terrestris (Vauch.) De Candolle 1805, p. 62
Pl. 68, Fig. 4
Either aquatic or terrestrial, usually forming floating clots; fila-
ments rather slender, 50-80 in diameter, branching dichotomous,
or at right angles to the main filament (as in the case of the relatively
long branches which bear the sex organs ); monoecious; oogonia
subglobose to ovoid, at the end of a slightly bent stalk, with the
pore directed downward, exceeding the antheridium and appearing
to be terminal on the branch, 60-103 in diameter, 85-211, long;
antheridia strongly circinate, 15-20 in diameter, terminating the
branch but appearing to arise beneath the oogonium; oospore with
a thick, 4-layered membrane, completely filling the oogonium which
falls with the oospore.
Floating in hard or soft water lakes and small ponds, becoming
mature and fruiting abundantly at low temperatures. This species
is also found on moist soil, especially in well-shaded habitats. Mich.,
Wis.
ORDER ZYGNEMATALES
Except for the desmid families in which there are unicellular
genera (See Appendix) plants in this order are unbranched
filaments without basal-distal differentiation. Rarely, incidental
rhizoidal branches may be formed where filaments come in contact
[ 294 ]
with substrates. The cells are long or short cylinders, but in some
species the cells become inflated during the reproductive process
(conjugation ). The cell wall has 1 or 2 layers of firm cellulose and
an outer pectose layer of varying thickness and consistency. The
mucilaginous sheath present in most forms is responsible for the
fact that these plants very seldom become hosts for epiphytes
although frequently parasitized by Lagenidium and Myzocytium
(Phycomycetes). The end walls of the cells are separated by a middle
lamella and may be either plane or characteristically infolded
(replicate). One of the most characteristic features of this order
is the relatively large size of the chloroplasts, usually 1 or 2 in each
cell, although in Spirogyra there may be several (up to 16).
Pyrenoids in the chloroplasts are large and conspicuous, but in
Mougeotiopsis pyrenoids are lacking. The chloroplasts may be axial
plates, stellate masses or cushions, or parietal spiral ribbons. In asex-
ual reproduction aplanospores and akinetes are sometimes formed.
It is in sexual reproduction that plants in this order show their most
distinctive characteristics. Either all or part of the vegetative cell
content serves as a gamete, union being achieved by one or both
gametes passing through a tube which forms between the cells of
two filaments (scalariform conjugation) or between cells of the
same filament (lateral conjugation). In a few species, filaments
become adjoined or are juxtaposed, and gametic union is achieved
without the use of tubes. The resulting zygospore has a wall which
is usually 3-layered and thick. It may be smooth or the outer layers
may be decorated with scrobiculations, pits, or reticulations, features
which are specific and of taxonomic importance. The gametangial
cells after conjugation may be empty or may become filled with
pectic compounds which are usually deposited in layers.
Motile reproductive cells do not occur. This, together with other
fundamental details of the life history, behavior of the germinating
zygospore, etc., set the Zygnematales well apart from other orders of
the Chlorophyta, so that in some systems of classification they have
been placed outside the Chlorophyceae.
Of the 3 families which comprise this order (Zygnemataceae, Me-
sotaeniaceae, Desmidiaceae*) only the first is considered in this
book.
FAMILY ZYGNEMATACEAE
Characteristics as described for the order; cells short- or long-
cylindric with plane or folded end walls, usually unbranched and
without basal-distal differentiation; chloroplasts few, large, and,
except for one genus, with conspicuous pyrenoids.
*See appendix for desmid genera.
[ 295 ]
Besides conjugation, described above, akinetes (thick-walled rest-
ing cells formed by modification of vegetative cells) or partheno-
spores (aplanospores ) may occur. The latter are thick-walled, zygo-
spore-like bodies formed within cells independent of conjugation.
Reproductive material often can be identified in the field, espec-
ially in Spirogyra, Mougeotia, and Zygnema, by the foamy, brownish
or ‘dirty’ appearance of the plant masses. In many forms conjugation
regularly occurs in surface mats of filaments, each species fruiting
in its own season.
Key to the Genera
1. Cells with 2 broad, disc-like chloroplasts, mostly axial but in part
parietal; cell sap deep purples (rarely, colorless) = * Pleurodiscus
1. Cells with other types of chloroplasts; cell sap colorless (but
lilac or purplish-brown in Mougeotia Capucing ee 2
to
Chloroplasts parietal ribbons (usually with laciniate or crenate
margins ), spiral (rarely nearly straight), with several
to many pyrenoids in a Siig lesserics == Spirogyra
(including Sirogonium )
2. Chloroplasts axial, shaped otherwise, broad bands, stellate bodies,
elongate pads, or axial polster (cushion-shaped) bodies == 3
3. Chloroplasts axial plates or bands, broad and filling the width of
the cell in some; pyrenoids none, or 2 to many, in 1 row or Scattered ae 4
3. Chloroplasts (usually 2) axial, star-shaped or pad-like bodies aS PE Ys
4. Chloroplasts without pyrenoids_____--------------_--------- Mougeotiopsis
4, Chloroplasts with pyrenoids._________----------------——-------------- 5
5. Conjugating cells formed by a portion of the
vegetative cell cut off from one end —-_________-- *Temnogametum
5. Conjugating cells involving the entire vegetative cell 6
6. Conjugating cells becoming filled with pectic substances —___- Debarya
6. Conjugating cells not becoming filled with pectic substances,
often containing granular residues ____--------------------------------— Mougeotia
7. Chloroplasts 2 central, polsterform bodies (without, or with very
short, radiating processes); cytoplasmic granular material left in
conjugating cells and in ‘sporangia + -.------____-------------- Zygogonium
7. Chloroplasts 2 star-shaped bodies in each cell
(radiating processes long) =. ——--=--=-——- =n 8
8. Conjugating cells becoming filled with pectic substances;
zygospores always formed in the tube, spheroidal or mostly
quadrate, flattened or polsterform in side view ——----- Zygnemopsis
8. Conjugating cells not becoming filled with pectic substances;
zygospores formed in the tube or in one of the
gametangia, globose, ovate, or somewhat cylindric_________— Zygnema
DEBARYA (Wittr.) Transeau 1934, p. 203
Filaments of slender, cylindrical cells; chloroplast a narrow axial
plate containing 2-8 pyrenoids (these sometimes increasing in
number prior to conjugation); conjugation scalariform by pro-
tuberances from both gametangia; zygospores variable in shape,
[ 296 ]
ovate, quadrangular-ovate, or spheroidal, formed between the
gametangia, the median wall yellow, brown, or blue, smooth or
variously ornamented; gametangia becoming filled with pectic
substances but without residues of cytoplasmic granules; reproduc-
tion also by aplanospores and akinetes.
This genus is so much like Mougeotia in its vegetative expression
that identification cannot be made unless reproductive stages are
at hand.
Key to the Species
Zygospores lenticular, with 3 transverse ridges,
30—48u in diameter, 42-72 long. D. glyptosperma
Zygospores compressed-globose, median spore wall
tricarinate, 50-54 in diameter, 52-654 long D. Ackleyana
Debarya Ackleyana Transeau 1944, p. 244
Vegetative cells 12-15, in diameter, 90-140, long; chloroplast an
axial ribbon with 8 pyrenoids; zygospores compressed-globose or
ovate, median spore wall with 3 ridges, the lateral ones ruffled and
with transverse corrugations between the ridges, middle keel 10
wide and radially striated, polar walls finely pitted, 50-54 in
diameter, 52-65, long.
Douglas Lake, Michigan.
Debarya glyptosperma (DeBary ) Wittrock 1872, p. 35
Vegetative cells 9-16 in diameter, 50-200, long; chloroplast an
axial plate with several pyrenoids; zygospores lenticular or
compressed-ovate, median spore wall with 3 ridges which extend
as projections at the poles, the ridges interconnected by transverse
striations, 30-48, in diameter, 42-72, long.
Douglas Lake, Michigan.
MOUGEOTIA (C. A. Agardh) Wittrock 1872, p. 35
Unattached filaments of cylindrical cells without basal-distal
differentiation (rarely with lateral anchoring rhizoidal branches
near one end of the filament), forming entangled cottony masses,
floating or caught among aquatic plants, sometimes attached and
epiphytic on submerged culms of Scirpus, etc. Chloroplast occasion-
ally rod-like, usually a broad axial plate, sometimes 2 plates
connected by a bridge; with either an axial row of pyrenoids or
with pyrenoids scattered over the surface; sometimes twisted in
the midregion of the cell. Conjugation usually scalariform, the
zygospore formed in the tube between the gametangia; the zygo-
spore and tube sometimes enlarged so as to divide the gametangia,
[ 297 ]
giving the sporangium the appearance of being bounded by as many
as
4 cells. Zygospore wall smooth or variously decorated; with
residues in the gametangial cells outside the zygospore.
bo e
bo
. Zygospores
. Zygospores
The genus should be compared with Debarya.
Key to the Species
. Reproduction by aplanospores only; conjugation
and zygospores unknown M. ventricosa
. Reproduction by conjugation; aplanospores present or absent................
. Zygospores formed in the tube, but extending into and
dividing one. of the Gametaneia Giga aosce seer eet ea ecae 3
. Zygospores formed wholly in the tube, or extending into
both gametangia ....... By sel Rae ATI Ln Te rok Ne ct WAY ADe ee exe 6
. Zygospores drum-shaped (short-cylindric) 0.0.0.0... M. varians
D0 19 OID D TTT A G9 9
Zygospores some other shape ................:ccccceecee ete ete ee ec eeer ene
Zygospores globose or triangular-ovate, 30—40u in diameter M. floridana
Zygospores ovate to subglobose, 40—45m in diameter........ M. sphaerocarpa
Zygospores formed wholly in the conjugating Guile pate ees ite eee
Zygospores extending into and dividing both gametangia...................... 22
Zig @aspore + Wall psmnOOtlay. cet ee cases obeges es cere coe sane epe aed brane ne nee ses eareee nee 8
Zygospore wall (median or outer layer) decorated... 17
. Vegetative cells 20—40u in diameter... etree 9
. Vegetative cells 204 in diameter or less............0.0..1:c eee 13
pe Spore: wall Woltpet estes cec eine tance ces tence cage nec ata sents oa alitacseceearsee M. maltae
P Spore, wall’ ‘rowan c.cc.g te seiko ie acarte cde cene nee taeeei ek eee oneemes ase 10
10. Zygospores cylindric-ovate in front VieW.............00c M. laetevirens
10. Zygospores some other shape ...............0c:ccccec settee tees ee te cseeeeeneeaeaeeeneey 11
11. Zygospores ovate, 40—48u in diameter.............0..0:: cee M. Hirnii
11. Zygospores some other shape .................:::c:ccesessseece teen ener 12
. Zygospores
diameter
quadrately ovoid to subglobose, 30—40u in
12. Zygospores ovate-globose, (23)—30—31u in diameter.............. M. scalaris
13. Zygospores globose) —.........-.... CAP eed) ME He UTR OA As kar he OO Mat toate ete 14
13. Zygospores quadrate-globose or rhomboid .................::: ese 16
14. Vegetative cells 6—12u in diameter..................0:c: eee M. parvula
14. Vegetative cells larger ....... ES Be tne cree Chale Tr nent 1S
15. Spore wall blue; vegetative cells 17—20—(22)u in diameter... M. maltae
. Spore wall brown; vegetative cells 12—18u in diameter
. Zygospores quadrate-globose or rhomboidal;
. Vegetative cells 8—16u in diameter.................0:: ee
. Spore wall brown, coarsely punctate
M. recurva
aplanospores oblique-ovate
. Zygospores sexangular- or octangular-globose;
aplanospores globose
. Vegetative cells (14)—18—20m in diameter. ...........0.... ee 18
. Zygospore wall punctate ................:cccee ree sceees tsetse retenenesenenenaneneneuttectoness 19
. Zygospore wall scrobiculate....................::ecsseceeetee eset tenenteatneneteneeceeenes 21
. Spore wall blue, finely punctate ...............00: ce M. cyanea
[ 298 ]
20.
20.
21.
21.
22.
22.
23.
23.
24.
24.
25.
25.
26.
26.
27.
27.
28.
28.
29.
29.
30.
30.
31.
31.
Vegetative cells 18—23u in diameter;
PY COSPOLES* PIODOSE! LO) \OVALE deste a eee nes ccs Soka nse p dass stion: M. micropora
Vegetative cells 24—29, in diameter; zygospores ovate-ellipsoid,
with flattened ends ................. fd wee A kee ty Aled ad eae ee eens M. pulchella
Zygospores 20—30—(36)u in diameter; ovate
to ‘broadly ellipsoid: pyrenoids an, J rOW.-..2.25.-.<:csee:savisse.tas beens M. laevis
Zygospores 35—41y in diameter, ovate to
subglobose; ‘pyrenoids ‘scattered 0.2... i020 iecese sate esseestedetetneie ties M. robusta
PESOS POLE Y NV lA ISTMO OEM: on. te. ok: Sth cagy her tes, be Sac wise se Meri Cade 23
Zyeospore wall decorated. :2...5 2.05. csexc.etsnsae et ads oe Oe AT We 29
Wesetative cells (4 —Spe im \diatmeter .22 acto cca soe ee eae estas se seen os secures ere 24
Vegetative cells (8)—9—24u in diameter...................0:c cette 26
Vesetativecells’ 4—5e in diameter: 7.0). f. uc se5s SH hee asnnadesss 25
WVeoetative cells 6—8m in diameter. 1c0j.1c25.-:-ceceeccees ns ne ee M. viridis
Zygospores irregularly quadrate, the angles extended ........... M. americana
Zygospores cruciate-quadrate, with concave
WHAT SINS «the, OMENS | LOUNGE {0c rsync. cvelcosec cece st toes ....M. elegantula
Zygospores globose, or angular-globose...............0....0.:0:cee M. calcarea
ZYGOSpPOres: Ovate, (OL UAGrAMmUlar 5G ck ec sates ateh ee erase techn consent a7
Zygospores ovate to subglobose; vegetative
Gals MO=OAbine Shan GUETTATE a nposatenndlt meee: onbeoncscbaaneecocienmbtbere M. sphaerocarpa
Zygospores quadrate; vegetative cells 8—19—(21)u in diameter ......... 28
Wallon WoUEplisinee eee een see ede en a BN ana ences M. capucina
Gellscsapenotypurplshis inet ee tee Ue eee NT Sl ohtitec deance M. virescens
Vegetative cells (8)—13—16u in diameter;
Nala GlarmeOSPOLe . PIMCtALG gti. ia ct oe ohe ah ook Skabace cn it vea lige gas enentanensa 30
Vegetative cells 5—8.5u in diameter; wall of
ZYSOSPOTe SCrODICUIALS OT VELEUCOSE. ¥....2c2.0-.c ese che tee taht qracs sh aneseeepogesmcs tes a
Zygospores cruciate-quadrate, sides concave, 18—29u in
diameter, 30—38u long; vegetative cells 8—10u
Thalys (GuPiba 0 (21U2) eee ROU NY CEC Dy 2 Ua DOGS Boia iene RAW ot Poymer ai Ras M. punctata
Zygospores quadrate, sides straight, 28—40u in diameter;
vegetative cells (8)—14—16u in diameter........................ M. quadrangulata
Zygospores quadrate with tumid margins, wall
MUUUMTILE]y eESCTOOLCU ALE nfo 5 cece oo eco i paeta ee age cepaety tne exon neck eeas sacs M. tumidula
Zygospores quadrate, with concave margins, wall
THINMLEl Va WERENCOSCY |. Focihtt5. oy raed 2 ae eater e. orho mean sdwaeoetne M. gracilima
Mougeotia abnormis Kisselew 1927, p. 301
[M. notabilis Hassall 1842, p. 46]
Pl. 70, Figs. 3, 4
Filaments forming sparse entanglements; vegetative cells long-
cylindric, 10-21,» in diameter, 50-111-( 250), long; chloroplast filling
the length of the cell. Zygospores formed almost entirely within the
conjugation tube but extending into and filling one of the gametan-
gia; triangular or quadrate-ovate, with margins concave and median
spore wall smooth; 24-26, in diameter, 26-36, long.
Our specimens are referred to M. abnormis on the basis of their
agreement with the published partial description.
Among other algae in ponds and lake margins. Wis.
[ 299 ]
Mougeotia americana Transeau 1918, p. 237
Filaments slender; vegetative cells 4-5. in diameter, 40-120,
long, becoming geniculate in conjugation. Zygospores formed in
the tube, but extending into both the gametangia; irregularly
quadrate, the margins concave or convex, with angles produced
and truncately rounded; median spore wall colorless and smooth;
13—24, in diameter, 18—32y long; sporangium membrane becom-
ing filled with pectic substance.
Douglas Lake, Michigan.
Mougeotia calcarea (Cleve) Wittrock 1872, p. 40
Vegetative cells 8-14 in diameter, 40-280, long, filaments be-
coming geniculate in conjugation. Zygospores formed in the tube
but extending into the gametangia; globose or somewhat angular,
the wall colorless and smooth; 25-30 in diameter, or (if angular)
22-28y in diameter, 30-50, long.
Mich.
Mougeotia calcarea var. bicalyptra (Wittr.) Transeau 1926, p. 316
Vegetative cells 10-12. in diameter, 30-110» long; zygospores
with thick end walls adjacent to the gametangia, extending into and
at times completely dividing the gametangia.
Mich.
Mougeotia capucina (Bory) C. A. Agardh 1824, p. 84
Pl. 70, Figs. 5, 6
Filaments long and slender, forming purplish, cottony masses;
vegetative cells 14-21, in diameter, 70-150-(280) » long; chloroplast
a narrow axial band with 4-6 pyrenoids (sometimes as many as 12
or 16) ina single series. Zygospores formed in the tube but extending
into and dividing both gametangia; irregularly quadrangular with
concave margins, the wall brownish-violet and smooth; 50-74, in
diameter, 80-100y long; with lamellate pectic substances deposited
in the angles of the spore.
This species is often found fruiting during late summer along lake
margins where water has receded. It forms purple films on
moist substrates or purple cloud-like masses about the stems of
Chamaedaphne.
A collection of M. capucina from a Sphagnum bog in Cheboygan
County, Michigan, showed mature zygospores with minute puncta-
[ 300 ]
tions when viewed under oil immersion magnification (H. K. Phinney
manuscript ).
Entangled about reeds and in shallow water of beach pools;
common in acid habitats and Sphagnum bogs. Mich., Wis.
Mougeotia cyanea Transeau 1926, p. 321
Vegetative cells 14-18-(20) in diameter; chloroplast one-third
to one-half the cell in length. Zygospores formed in the tube, not
dividing the gametangia; compressed-globose; at right angles to
the tube; wall blue, finely punctate; 30-40, in diameter, 38-48, long.
Douglas Lake, Michigan.
Mougeotia elegantula Wittrock 1872, p. 40
Pl. 70, Figs. 7, 8
Filaments very slender, becoming geniculate in conjugation; cells
long-cylindric, 4-4.5 in diameter, 50-135p long; chloroplast a thin
plate, not quite equalling the cell in length, containing 4-8 pyre-
noids. Zygospores formed in the tube and dividing both gametangia;
quadrate with concave margins, the wall smooth, hyaline; 18-25.
in diameter.
Forming cottony masses in shallow water. Mich., Wis.
Mougeotia floridana Transeau in
Transeau, Tiffany, Taft, & Li 1934, p. 224
Vegetative cells 14-20 in diameter, 60-200, long; chloroplast
with 6-8 pyrenoids in 1 series. Zygospores formed in the tube and
extending into one gametangium; globose or triangular; the median
wall yellow and smooth; 30-40 in diameter, 36-48, in long
dimension.
Mich.
Mougeotia genuflexa (Dillw.) C. A. Agardh 1824, p. 83
Pl. 70, Figs. 9, 10
Filaments slender, frequently conjugated by geniculations but
not producing zygospores; cells 25-38, in diameter, 50-100—( 225) p
long; chloroplast a broad band filling the length of the cell, with
several pyrenoids. Zygospores formed either by lateral or (more
rarely) scalariform conjugation, within the tube, not dividing the
gametangia; quadrately-ovate or subglobose; median wall smooth
and hyaline; 30-35-(40) » in diameter.
Among beds of vegetation in lagoons and lakes; rather common
in Sphagnum bogs, growing luxuriantly in shaded habitats. Mich.,
Wis.
[ 301 ]
Mougeotia genuflexa var. gracilis Reinsch 1867, p. 215
Smaller than the typical; vegetative cells 15-24, in diameter;
zygospores 24-30, in diameter.
Mich.
Mougeotia gracilima ( Hass.) Wittrock 1872, p. 40
Vegetative cells 5-7» in diameter, 55-140n long. Zygospores
dividing both gametangia; quadrate with concave margins to retuse
angles, the wall finely verrucose; 20-25, in diameter, 20-28p long.
Mich.
Mougeotia Hirnii Transeau in
Transeau, Tiffany, Taft, & Li 1934, p. 218
Vegetative cells 25-28. in diameter, 60-140, long. Zygospores
formed in the tube, not dividing the gametangia; ovate; the median
spore wall smooth, yellow to brown; 40—48, in diameter, 43—50y
long.
Mich.
Mougeotia laetevirens (A. Braun) Wittrock in Wittrock
& Nordstedt 1877, Algae Exsic. No. 58
Pl. 70, Figs. 11-14
Filaments forming light green, cottony growth; cells long-cylindric;
(22)-27—40p in diameter, up to 350, long; chloroplast a broad band
extending the full length of the cell, containing an indefinite number
of irregularly arranged pyrenoids. Zygospores formed by scalariform
conjugation in the tube, not dividing the gametangia; cylindric or
ovate in front view, with lateral walls convex, free walls concave;
median wall smooth and brown; 36-50, in diameter, 45-73, long.
Mich., Wis.
Mougeotia laevis (Kuetz.) Archer 1866, p. 272
[Debarya laevis (Kuetz.) West & West]
Pl. 70, Figs. 1, 2
Vegetative cells elongate-cylindric, 20-26, in diameter, up to 5
times the diameter in length; chloroplast with 2-4 pyrenoids.
Zygospores formed in the conjugation tube, not dividing the game-
tangia; ovate to broadly ellipsoid; outer wall smooth, median wall
coarsely scrobiculate; 20-30-(36) » in diameter, 42-50» long.
Shallow water of ponds and ditches. Mich., Wis.
Mougeotia maltae Skuja 1926, p. 111
Vegetative cells 17-22 in diameter, up to 160, long; chloroplast
with a single row of 4-8 pyrenoids. Zygospores formed in the tube,
[ 302 ]
not dividing the gametangia; globose; median spore wall blue and
smooth; 30—35—( 40)» in diameter.
Mich.
Mougeotia micropora Taft in
Transeau, Tiffany, Taft, & Li 1934, p. 218
Pl. 74, Fig. 5
Vegetative cells 18-234 in diameter, 60-160, long; chloroplast
with 4-6 pyrenoids in 1 series. Zygospores formed in the tube, not
dividing the gametangia; globose, ovate, or compressed, parallel
with the tube; median spore wall brown and punctate; 26-36, in
diameter, 26-30, long; sporangium finally becoming inclosed by a
thick layer of pectose.
Mich.
Mougeotia nummuloides ( Hass.) DeToni 1889, p. 718
Vegetative cells 8-16. in diameter, 32-160, long. Zygospores
formed in the tube, not dividing the gametangia; globose to ovate;
median spore wall brown and scrobiculate; 17-37, in diameter.
Mich.
Mougeotia parvula Hassall 1843, p. 434
Vegetative cells 6-12 in diameter, 30-140 long; chloroplast 4
the length of the cell, with 4-6 pyrenoids. Zygospores formed in
the tube, not dividing the gametangia; globose; median spore wall
brown and smooth; 13-24, in diameter.
Mich.
Mougeotia pulchella Wittrock 1871, p. 88
Vegetative cells 24-29, in diameter, 48-150, long; chloroplast
with pyrenoids in a single series. Zygospores formed in the tube,
not dividing the gametangia; ovate or ellipsoid, with flattened ends;
median spore wall brown and punctate; 28-35, in diameter, 40-50
long.
Mich.
Mougeotia punctata Wittrock 1867, p. 21
Pl. 71, Fig.1
Filaments forming sparse, cottony growths; cells short- or long-
cylindric, 8-10 in diameter, (50)-115-135, long; chloroplast a
broad plate with 4-6 (or more ?) pyrenoids. Zygospores formed in
the tube and dividing both gametangia; quadrate with retuse
margins; outer spore wall coarsely punctate or pitted; (18)-29y
in diameter, 30-33-(38) » long.
Among reeds.in a small lake of soft water. Wis.
[ 303 ]
Mougeotia quadrangulata Hassall 1843, p. 434
Pl. 71, Figs. 3-5
Vegetative cells long-cylindric, 14-16» in diameter, 135-150, long;
chloroplast a broad plate extending the full length of the cell, with
4-6 pyrenoids. Zygospores formed in the tube, dividing both
gametangia; quadrate, with straight or slightly retuse margins, ovate
when seen from the side; wall finely scrobiculate or punctate,
colorless; 28-40 in diameter.
In shallow water of lake margins and swamps. Mich., Wis.
Mougeotia recurva ( Hass.) DeToni 1889, p. 714
Vegetative cells 12-18» in diameter, 50-180, long. Zygospores
formed in the tube, not dividing the gametangia; globose; median
spore wall brown and smooth; 23—33p in diameter.
Mich.
Mougeotia Reinschii Transeau in
Transeau, Tiffany, Taft, & Li 1934, p. 224
Vegetative cells 9-13, in diameter, 80-160) long; chloroplast with
5-8 pyrenoids in a single series. Zygospores usually formed by
lateral conjugation, or in the tube by scalariform conjugation, not
dividing the gametangia; quadrangular-globose or rhomboid; me-
dian spore wall yellow and smooth; 25-30, in diameter.
Mich.
Mougeotia robusta (DeBary ) Wittrock in
Wittrock & Nordstedt 1884, Algae Exsic. No. 651
Pl. 74, Fig. 7
Vegetative cells 25-33. in diameter, 75-260p long; chloroplast
with many irregularly placed pyrenoids. Zygospores formed in the
tube, not dividing the gametangia; ovate to subglobose; median
spore wall brown and scrobiculate; 35-41, in diameter, 47-54, long.
Mich.
Mougeotia robusta var. biornata Wittrock in
Wittrock & Nordstedt 1884, Algae Exsic. No. 615
Vegetative cells 27-30, in diameter, 25-240» long. Zygospores
with outer wall inwardly verrucose, median spore wall scrobiculate;
30-38, in diameter, 42-50, long.
Mich.
Mougeotia scalaris Hassall 1842, p. 45
Pipiierigss67
Vegetative cells 20-27—-(34) in diameter, 40-180,» long; chloro-
plast a broad plate with 4 pyrenoids. Zygospores formed in the tube
[ 304 ]
by scalariform conjugation, not dividing the gametangia; globose
or broadly ovate; walls smooth and golden brown; 25-3lp in
diameter, 27—40p long.
In littoral flora of many lakes. Mich., Wis.
Mougeotia sphaerocarpa Wolle 1887, p. 227
Pl. 74, Fig. 6
Vegetative cells 19-24, in diameter, 60—-120—( 240) long; chloro-
plast with 4-6 pyrenoids. Zygospores formed variably, sometimes
dividing one or both gametangia; subglobose to ovate; median spore
wall brown and smooth; 40-45, in diameter, or 36-40, in diameter
and 40-55y long.
Mich.
Mougeotia tumidula Transeau 1914, p. 297
PIT? Fig.2
Vegetative cells long-cylindric, 6-8» in diameter, up to 120,» long;
chloroplast a broad plate with 4-8 pyrenoids in one series.
Zygospores formed in the tube, dividing both gametangia; quadran-
gular; both inner and outer spore walls minutely scrobiculate;
22-26, in diameter, 26-30, long.
Mich.
Mougeotia varians ( Wittr.) Czurda 1932, p. 79
Ploya, Figs. 1112
Vegetative cells 25-27, in diameter; chloroplast a broad band
entirely filling the length of the cell, with 4 pyrenoids. Zygospores
formed in the tube, dividing one of the gametangia; cylindric or
drum-shaped, the free walls concave, the walls adjoining the
gametangia convex; median wall smooth and brown; 48-60, in
diameter, 60-70—(78 ) » long.
This species is smaller than M. laetevirens (A. Braun) Wittr.
and also differs in that the zygospore completely fills the gametangial
cell, whereas in M. laetevirens the spore is formed entirely within
the conjugation tube.
In the tychoplankton of soft water lakes. Mich., Wis.
Mougeotia ventricosa ( Wittr.) Collins 1912, p. 69
Vegetative cells 5-8—(9)» in diameter, 100-140» long. Zygospores
unknown. Aplanospores obliquely ellipsoid to subglobose; median
spore wall yellow and smooth; 12-24, in diameter, 16-29, long.
Mich.
[ 305 ]
Mougeotia virescens ( Hass.) Borge 1913, p. 43
PI. 72, Figs. 1, 2
Vegetative cells 8-9-(11) in diameter, 30-80-(130)p» long.
Zygospores formed in the tube, dividing both gametangia; quadrate
with concave margins and rounded angles; wall smooth and color-
less; 29-34.5u in diameter.
Our specimens agree with M. virescens except that the vegetative
cells are a little longer than described.
In a small pond, Sawyer County, Wisconsin.
Mougeotia viridis (Kuetz.) Wittrock 1872, p. 39
Pl. 71, Figs. 8-10
Filaments slender, becoming geniculate in conjugation; cells 6-Sy
in diameter, 24-40-(80), long; chloroplast a broad plate extending
the full length of the cell with 4-6 pyrenoids. Zygospores formed
in the tube, dividing both gametangia; quadrate, the sides concave,
corners retuse; median spore wall smooth and colorless; 24—32y
in diameter.
This is the most common species of Mougeotia in our collections.
It appears in many shallow water situations and in roadside trickles,
seeps from banks, etc.
Tychoplankter; in several lakes; in swamps. Mich., Wis.
MOUGEOTIOPSIS Palla 1894, p. 228
Filaments slender, composed of short cylindrical cells; 1 axial,
plate-like, folded chloroplast without pyrenoids; conjugation scala-
riform, the zygospore formed in the tube, protruding into one or
both of the gametangia and not cut off from them by a wall;
entire contents of the gametangial cells used in the formation of
the zygospore; gametangial cells not becoming filled with lamellate
pectic substances.
Mougeotiopsis should be compared with Debarya, from which it
may be differentiated in the vegetative condition by the presence of
pyrenoids in the latter. In the reproductive phase Mougeotiopsis
may be identified by the lack of pectic substances in the old
gametangial cells. In our specimens a gelatinous sheath was some-
times present about the filaments.
Mougeotiopsis calospora Palla 1894, p. 228
Pl. 69, Figs. 4-6
Filaments light green, long and loosely entangled. Cells short-
cylindric, sometimes quadrate in the vegetative state, becoming
elongate in conjugation; 12-14, in diameter, 14-18» long. Chloro-
[ 306 }
plast a broad, folded axial plate, almost as long as the cell (sometimes
ulotrichaceous in appearance). Zygospores formed in the connecting
tube by’scalariform conjugation, and extending into the gametangia;
oblong or rectangular-oblong; outer spore wall smooth, middle wall
with deep pits; 22-25, in diameter, 33-38, long (rarely longer).
This species was once described as Mesogerron fluitans Brand and
included in the Ulotrichaceae because of its Ulothrix-like chloroplast.
Our specimens were found only in the vegetative condition, but
this plant is so distinctive that it can be assigned to M. calospora.
Rare in several lakes and Sphagnum bogs. The plants seems to
be confined to soft water habitats. Mich., Wis.
SPIROGYRA Link 1820, p.5
Filaments long and unbranched, usually without basal-distal
differentiation but sometimes with rhizoidal branches developing
laterally where the filament comes in contact with substrate. Cells
cylindrical, short, to very long in some species, with plane (even
and smooth), replicate, or colligate (exterior H-shaped piece) end
walls. Chloroplast a parietal band or ribbon which may be spirally
twisted 14 to 3 (rarely 8) turns, or may be nearly straight (as in
genus Sirogonium, not separated here); 1-16 chloroplasts in a cell.
Conjugation either lateral or scalariform, usually by the formation
of tubes, rarely by geniculate bendings of the filament so that
conjugating cells are brought into juxaposition. Zygospores formed
in one of the gametangial cells, which may become swollen, depend-
ing upon the species; zygospores ovate, subglobose, ellipsoid, or
oblong, with 3-layered wall, of which the middle layer may be
smooth or decorated and colored. Aplanospores uncommon, similar
to the zygospores in shape and wall markings; rarely aplanospores
alone occur.
Spirogyra is the largest genus in number of species and the most
common of Zygnemataceae. It is identifiable in the field by its
bright green, cottony growths and its slippery mucilaginous texture.
In hand, a mass of filaments is easily drawn out into a long fine
thread.
In deep cold springs and pools Spirogyra flourishes abundantly
and vegetatively, forming enormous green ‘clouds’ several feet in
diameter in favorable habitats. In shallow warm water it has a
tendency to form floating mats, with conjugation and subsequent
disintegration of the filaments occurring. During conjugation the
plant masses become dull, dirty-green or brownish, often with a
burnt-orange tinge, which is almost invariably macroscopic evidence
that reproduction is in progress. Some species of Spirogyra seem to
[ 307 ]
prefer hard water habitats with a pH between 7.0 and 8.5 (S. crassa,
for example). Others are always found in shallow water which is
rich in organic acids and where there is a considerable amount of
disintegrating vegetation.
As in most other genera of the Zygnemataceae, species identifica-
tion cannot be made without mature zygospores, or in some cases
aplanospores. Of the 258 or more known species of Spirogyra, only
50 have been found fruiting in our region, hence the following key
is greatly limited.
In those species of Spirogyra which have a large number of closely
spiraled chloroplasts a count may be made easily by focusing on
a band at the upper side of the cell, counting this as 1. Then by
focusing down, the number of bands which are seen to be crossed
by this one and added to it will give the total number of chloroplasts.
Key to the Species
1. End walls of cells plane (not folded) _—____..— = -—= =~ __ 13
1. End walls of cells replicate (infolded) — ------ —-- --- —- -— —- —--—— 2)
2. Median wall of zygospore smooth ____-_-------------------------------____-__-----—- 4
2. Median wall of zygospore not smooth —______---------------------------_______---- 3
3. Median spore wall with conical projections;
spores 52-63. in diameter _____——_---------------- S. borysthenica
3. Median spore wall reticulate; spores 45-75 in diameter _______- S. inconstans
4. Conjugation tubes formed only from thy irra @allg 5
4. Conjugation tubes formed from both cells ——________---_-—------- 6
5. Zygospores ellipsoid; fertile cells inflated on both sides - __ S. Spreeiana
5. Zygospores ovate; fertile cells inflated on conjugating side — S. Grevilleana
6. Chloroplasts 1 (rarely 2) in each cell _-----_________-----------— 8
6. Chloroplasts 3-5 (2-4 in some cells) === ees petites. “feiss eee tT i
7. Vegetative cells 28-33, in diameter; zygospores 35—47u
in diameter; fertile cells cylindric _____________-__-_-_--_____-____ S. gratiana
7. Vegetative cells 33-45, in diameter; zygospores 45-60
insdiameter> fertileycells inflated), = S. fallax
8. Vegetative cells 8-13-(15) in Glare te re ee neni S. tenuissima
8. Vegetative cells larger _-_------------------———-—--—— 9
9. Vegetative cells 15-20 in diameter (rarely with 2
chloroplasts ); fertile cells FROGSOVSTT SUAVE oe S. inflata
9. Vegetative cells larger -._____----------- 10
10, Spores ovate 2. ee 11
10, ‘Spores ellipsoid 2. ee 12
11. Inner layer of outer spore wall scrobiculate; vegetative cells
(28)-32-36-(44)u in diameter; fertile cells cylindric —__. S. protecta
11. Both median and outer walls of spore smooth; vegetative cells
19-30. in diameter; fertile cells slightly enlarged — S. Weberi
12. Fertile cells much inflated, fusiform; vegetative
Cells) 24-304 mnidiamecton ee ee S. Farlowii
12. Fertile cells cylindric; vegetative cells up to 40 in diameter _____ S. laxa
13. Chloroplast 1 (rarely 2) in each cell —-.----_________-_» 14
13. Chloroplasts 2-16 in each cell __---- -- --—- 88
. Conjugating tubes arising only or mostly from the male Celleshet cee 15
. Conjugating tubes arising from both cells; or conjugation
ocurring by geniculate bending of the filaments
Withaue bes. pei, toLmed.— . eke ee I itz
15. Vegetative cells 15—24y in diameter ___—____-____-_-_----_______-__ S. Collinsii
lea Veretativercells larger sss == ne eee ee 16
16. Median spore wall punctate; spore 37-42u in diameter. S. micropunctata
16. Median spore wall smooth; spore 44—54y in diameter... S. reftexa
ieeechandes poreswallysmooth == eS on
je Miechan spore: wallydecoited = eS 18
18. Vegetative cells 11-14u in Giameten] == aaeaen one A Ores S. porangabae
iseeVecctaverce|iswlarger == =) = SSS eS i
19m Median spore’ wall’scrobiculate = = S. scrobiculata
(oe Mediansspore: wallizcticulate= Sa Ee 20
20. Spore ovate, 43-46 in diameter______________________ S. sulcata
20. Spore ellipsoid, 35-444 in diameter. Bats S. daedaleoides
21. Spores varied in shape, ovate, ellipsoid, or irregular when seen
from the same angle; 24—36y in diameter ee pe re S. pratensis
21. Spores uniform in shape when seen fromthe same angle) 222 oN
22. Vegetative cells less than 15 in diameter S. flavescens
22. Vegetative cells more than 15y in TATA CET meee ee ce ne ee ere o3
23. Spores ovate ———._______________--- 24
23. Spores ellipsoid ———________ 28
24. Spores 18-20-(35) in diameter; vegetative cells
AAGLDNS fitea e 6 N12 T6421 (=) GOs a el ee aan Rear as SeaPesae i S. subsalsa
24. Spores larger; vegetative cells mostly larger_—________________________-__- 25
25. Spores 38—50u in’ diameter —_________-_—_——— S. porticalis
25. Spores smaller, (28)—33—38—(39) mu in diameter ........0....00:1 cee 26
26. Vegetative cells 24-26, in diameter; spores
94-29u in diameter __ ae Mote. ay ee ee eee Sa TPTES
26. Vegetative cells and spores larger ___---------—------------------________---------- 27
Diesbertile icelisueylingsi@s 8 a eS S. longata
O7/, Wwesdulle @alls travileawec! Gin lowtin GieleS. S. suecica
28. Sporangia cylindric (rarely slightly enlarged by
thetsporeybut nok millated ies=) = 23 2 29
28. Sporangia inflated on one or both sides __-----------_-________-------- 82
29. Vegetative cells 48—62u in diameter_____--------__________- S. condensata
29. Vegetative cells smaller —___________-____---_---_____-___-________-__---—- 30
30. Vegetative cells 18-26 in diameter, relatively stout, up to 904
long; spores 28-33 in diameter_______-> S. communis
30. Vegetative cells greater in diameter, but relatively
more slender; up to 240y long —______— 81
31. Vegetative cells 24—30u in diameter, up to 125
long; spores 28-33 in diameter______--------------—---—---------___- S. Juergensii
31. Vegetative cells averaging larger, 28-36-39, in diameter, up to
240» long; spores 27-37 in diameter —____________------------—_-_-- S. singularis
32. Vegetative cells 40-50y in diameter______----------------_- S. circumlineata
32. Vegetative cells smaller __________--___-- 33
33. Vegetative cells 16-24» in diameter. S. gracilis
33. Vegetative cells larger ———_______-___---_--___-_—__----____ 34
34. Sporangia (female cell) inflated on both sides — 37
34. Sporangia inflated only on one side ___------—---____---------------- 35
[ 309 ]
. Sporangia inflated only on outer side; vegetative
cells GO—3.5 coin cian te ys 55 eater ta Ree ee eee Evy S. Borgeana
. Sporangia inflated mostly on the inner (conjugating) side 36
» Vegetative cells 23—30x, in diameter. 2) sa) es S. Teodoresci
wy Vegetativercells)30—40.0. im) diameters em smen bane ne ese tv) S. varians
. Spores 28-33. in diameter, short, up to 50u long;
sporangia’ (decidedly mnfiated ssa. Fe er eee een a S. affinis
. Spores averaging smaller, 24—30u in diameter, and much longer
up to 90u; sporangia slightly inflated to 38m... S. catenaeformis
. Conjugation by geniculate bending of filaments, without
conjugation tubes (Sirogonium of some authors) 39
;) Conjugation| by tubes formed: from:both’cells 2s 2 ee eee 40
. Vegetative cells 38—56u in diameter; spores 41-64
inidiameter; median spore: wall smooth =) /2 ih ees =e S. stictica
. Vegetative cells 51-60. in diameter; spores 63-70u in diameter;
median spore wall wrinkled or granular. S. pseudo floridana
Median'sporemwalliismooth) i) 28221) a JA Ue SAN Enel oe SEEN Ste 2 41
Median spore; wall: not; smooths .2...28 4. a eae oe Te ee 49
. Vegetative cells 125-150» in diameter ...__________ S. ellipsospora
wNviegetative cells smalleny: 20 este See ae eke ME seen ne ee ee 42
. Conjugating cells inflated (or cylindric in S. majuscula)...............00....... 43
muConjugatingiucellsteylinidnicy serene «ohio ae pee 44
. Vegetative cells 50-80u in diameter; chloroplasts 3-8... S. majuscula
. Vegetative cells 40-50. in diameter; chloroplasts 2-3 —..________. S. dubia
» Vegetative cells more) than (tou: inydiameter eee 45
Vegetative cells lessithan) 49. in diameters 2 eee 46
5. Spores 60-80-(85)u in diameter, 90-170 long, ends pointed S. nitida
. Spores 87-108u in diameter, 120-155 long, ends not pointed __ S. jugalis
. Spores ovate, cylindric-ovate (sometimes nearly globose) ——__-_____ 47
Hespotes) ellipsoid) sess eimai i, Se dae Jal ele elie le ena BEE le 48
. Chloroplasts 3; spores ovate to subglobose,
34—48 in diameter, 48-54 long ____.._.___---_---_-__ S. triplicata
. Chloroplasts 2 (rarely 3 in some cells of the filament); spores
cylindric-ovate to subglobose, 31-40 in diameter, 31-68» long _ S. decimina
48. Vegetative cells 40-44u in diameter, up to 240u long; chloroplasts
3, making 1-2 turns; spores 832—40u in diameter — S. Fuellebornei
48. Vegetative cells averaging smaller, 36-41 in diameter, up to
400u long; chloroplasts 2-3, making 2% to 3% turns ._____ S. rivularis
49. Vegetative cells more than 100u in diameter —_._____________-_- 50
49" Vegetative cells less: than’\ 100” in diameter) 2s 51
50. Vegetative cells 140-165, in diameter; spores
compressed-ovate; median spore wall pitted__________________- S. crassa
50. Vegetative cells 118-140-(153)u in diameter; spores
compressed-spheroid; median spore wall reticulate ______ S. maxima
oll iSpores\ ellipsoid st? eae ee ee eee 52
9) SPOTES OV tee eee eee ee ee eS 53
52. Zygospores 32-42 in diameter, wall finely scrobiculate S. oriertalis
52. Zygospores averaging larger, 838-62u in diameter; median spore
wall irregularly sreticulate 000000 S. rhizobrachialis
53. Vegetative cells 23-25-(29)u in diameter —____________. S. aequinoctialis
oo. Vegetative ;cellsy larger _ 54
o4. Fertile cells cylindric =. esos) tt) eee eee S. novae-angliae
54- Fertile’ cellsisimflated! £03 282 ee S. fluviatilis
[ 310 ]
Spirogyra aequinoctialis G. S. West 1907, p. 105
Pl. 72, Figs. 3, 4
Vegetative cells long-cylindric, 23-29, in diameter, up to 150
long, with plane end walls. Chloroplasts 2-3, with crenate margins
and large pyrenoids, making 1 to 1% turns. Conjugation by tubes
from both gametangia, the receiving cells becoming symmetrically
inflated. Zygospores ovate or elongate-ellipsoid, with broadly
rounded poles; median spore wall with deep pits; (40)—41—50,
in diameter, (52)—72—77y long.
In shallow water of lake margins. Wis.
Spirogyra affinis ( Hass.) Petit 1880, p. 18
Filaments of rather stout cylindrical cells, 27-30. in diameter,
up to 90u long, with plane end walls. Chloroplast solitary, making
1 to 31/2 turns. Conjugation mostly lateral, but also scalariform,
tubes from both cells; sporangia inflated on both sides. Zygo-
spores ellipsoid; wall layers smooth; 28—334 in diameter, 30—50,
long.
Common in ponds and swamps. Mich., Wis.
Spirogyra Borgeana Transeau 1915, p. 23
PI77,. Figs: 7,8
Filaments of cylindrical cells, usually slender, 30-35, in diameter,
up to 200, long, with plane end walls. Chloroplast solitary, making
114 to 5 turns. Conjugation scalariform; sporangia inflated only on
the outer side. Zygospores ellipsoid; wall layers smooth; 33-40, in
diameter, 54-70» long.
Mich.
Spirogyra borysthenica Kasanowsky & Smirnoff 1913, p. 139
Filaments of slender cylindrical cells, 30-40, in diameter, 130-450,
long, with replicate end walls; chloroplasts 3-4, making 14 to
21/2 turns. Conjugation scalariform, tubes from both cells, fertile
cells swollen to twice the diameter of the vegetative cells. Zygo-
spores ellipsoid to fusiform; median wall with papillae; 52-63,
in diameter, 100—180, long.
Mich.
Spirogyra catenaeformis ( Hass.) Kuetzing 1849, p. 438
Filaments of rather stout cylindrical cells, 24-27-(32) in dia-
meter and up to 5 diameters in length, with plane end walls;
chloroplast solitary, making 1 to 6 turns. Conjugation by tubes from
both gametangia; fertile cells swollen; the sporangia inflated on
both sides. Zygospores ellipsoid; wall layers smooth; 24-30, in
diameter, 55-90, long.
Mich., Wis. 311]
Spirogyra circumlineata Transeau 1914, p. 293
Pl. 74, Fig. 8
Filaments of rather stout cells, 40-50, in diameter and 3-6 times
their diameter in length, with plane end walls; chloroplast solitary,
making 4 to 8 turns. Conjugation by tubes from both gametangia;
sporangia inflated mostly on the inner (conjugating) side. Zygo-
spores ellipsoid; wall layers smooth; 40-50» in diameter, 70-125p
long.
Mich.
Spirogyra Collinsii (Lewis) Printz 1927, p. 372
Pl. 77, Figs. 4-6
Filaments of rather slender cells, 15-24, in diameter, and about
5 times as long as broad, with plane end walls; chloroplast solitary.
Conjugation scalariform and lateral, the tube formed by the male
gametangium only; sporangia inflated slightly on both sides to
contain the spore; the male gametangium formed by a partitioning
off of one end of a vegetative cell. Zygospores ellipsoid; median wall
coarsely punctate; 35, in diameter, 60» long.
Mich., Wis.
Spirogyra communis ( Hass.) Kuetzing 1849, p. 439
Vegetative cells slender, cylindric, (18)-20-26, in diameter, (35)-
65-100, long, with plane end walls; chloroplast solitary, making 114
to 4 turns. Conjugation by tubes from both gametangia; fertile cells
cylindric. Zygospores ellipsoid, with narrowly rounded poles; median
spore wall smooth, colorless, or yellowish in age; 19-23, in diameter,
36-69, long.
Common in ponds and swamps. Mich., Wis.
Spirogyra condensata (Vauch.) Kuetzing 1843, p. 279
Pl. 72, Figs. 5, 6
Filaments of rather stout vegetative cells, (48)-53-62, in diameter,
45-94—(120) long, with plane end walls; chloroplast solitary, mak-
ing 14 to 4 turns. Conjugation by tubes from both gametangia, or
lateral; fertile cells cylindric. Zygospores ellipsoid; median spore
wall smooth and brown; 34-38 in diameter, 50-75y long.
In alkaline bog lakes. Mich.
Spirogyra crassa Kuetzing 1843, p. 280
Pli2,, Kigs..75.8
Filaments coarse, stout, feeling glassy to the touch; vegetative cells
cells (133)-—140-160, in diameter, quadrate or 2 times the diameter
in length, with plane end walls; chloroplasts 6-12 (usually 8-10),
[ 312 ]
slender, making 14 to 1 turn. Conjugation by tubes from both
gametangia; fertile cells cylindric. Zygospores ovate or laterally
flattened, the poles broadly rounded; median spore wall finely
pitted and brown; (80)—120—140, in diameter, 166-175, long.
Forming dark green masses of coarse filaments in quiet water of
bogs and pooled streams; apparently specific for hard water habitats.
Mich., Wis.
Spirogyra daedaleoides Czurda 1932, p. 180
Pl. 72, Figs. 9-11
Filaments of rather stout cylindrical cells, 30-35 in diameter,
70-148-(240) long, with plane end walls; chloroplast solitary,
making 3 to 4 turns. Conjugation scalariform by tubes from both
gametangia, or lateral; fertile cells becoming inflated. Zygospores
ellipsoid or ovate-ellipsoid; median spore wall coarsely reticulate
and brown; 35-(44) in diameter, (46)-—59-77, long.
In hard water lakes. Mich., Wis.
Spirogyra decimina (Mueller) Kuetzing 1843, p. 280
Filaments of rather stout cylindric cells, 34-40» in diameter,
60-125-(150), long, with plane end walls; chloroplasts 2 (rarely 3)
in each cell, broad, making 2 turns. Conjugation by tubes from both
gametangia; fertile cells cylindric. Zygospores cylindric-ovate, rarely
subglobose; median spore wall smooth; 31-40, in diameter, 31-68—
(75) long.
Forming cloudy masses on false bottom of an alkaline bog lake.
Mich., Wis.
Spirogyra dubia Kuetzing 1855, p. 8. Tab. Phyc. V
Filaments of rather stout cylindrical cells, (40)—43-50p in diam-
eter and up to 21% times the diameter in length, with plane end walls.
Chloroplasts 2 (sometimes 3), making 1 to 3 turns. Conjugation
scalariform by tubes from both gametangia; fertile cells inflated.
Zygospores globose or ovate; median wall smooth; 40p in diameter,
up to 80, long.
Mich., Wis.
Spirogyra ellipsospora Transeau 1914, p. 294
Pl. 72, Fig. 12
Filaments of stout cylindric cells, 125-150, in diameter, 125-230-
(500), long, with plane end walls; chloroplasts 3-8 narrow bands,
making 14 to 5 turns. Conjugation by tubes from both gametangia;
[ 313 ]
fertile cells cylindric. Zygospores ellipsoid or cylindric-ellipsoid, not
compressed; spore walls smooth, becoming yellow-brown in age;
100-140 in diameter, 160-255, long.
This species is readily differentiated from other large forms in
our collections (S. crassa and S. maxima) by the large ellipsoid
spores with smooth walls. In our region it has not been collected in
pure growths as have many other species of the genus.
Among other filamentous algae in shallow water. Mich., Wis.
Spirogyra fallax (Hansg.) Wille 1900a, p. 16
PI, 77, Wig. 10
Filaments of rather slender cylindrical cells, 33-45, in diameter
and up to 8 times the diameter in length, with replicate (rarely
plane) end walls; chloroplasts 3-5, making 14 to 14% turns (sometimes
nearly straight). Conjugation scalariform, the tubes short but formed
from both gametangia; fertile cells inflated (shortened). Zygospores
ellipsoid; wall layers smooth; 45-60, in diameter.
Mich.
Spirogyra Farlowii Transeau 1914, p. 291
Filaments of rather long cylindrical cells 24-30, in diameter and
up to 180% long, with replicate end walls; chloroplast solitary,
making 214 to 6 turns. Conjugation scalariform by tubes from both
gametangia; fertile cells fusiform, inflated. Zygospores ellipsoid;
median spore wall smooth; 32-45, in diameter, 48-93, long.
Mich.
Spirogyra flavescens ( Hass.) Kuetzing 1849, p. 438
Filaments of slender cells, 11-13, in diameter and up to 4 times
the diameter in length, with plane end walls; chloroplast solitary,
making 1 to 2 turns. Conjugation scalariform by tubes from both
gametangia, the fertile cells inflated. Zygospores ovate to cylindric-
ovate; median spore wall smooth; 20» in diameter, up to 30 long.
Mich.
Spirogyra fluviatilis Hilse in Rabenhorst
1864-1868, Algen No. 1476
Pl. 73, Figs. 4, 5
Filaments of rather stout cells, (30)-36—40-(45) in diameter and
5-6 times the diameter in length, with plane end walls; chloroplasts
3-5, making 11% to 214 turns. Conjugation scalariform by tubes from
both gametangia, fertile cells becoming inflated. Zygospores ovate;
median spore wall wrinkled and irregularly pitted; 42-44-(65) in
diameter, 59-77—(110) » long.
In pooled streams; common in lakes and ponds. Mich., Wis.
[314]
Spirogyra Fuellebornei Schmidle 1903, p. 76
Pl. 73, Fig. 6
Filaments of stout cylindrical cells, 40-44 in diameter, 120-200-
(240) long, with plane end walls; chloroplasts 3-4, making 1 to 2
turns. Conjugation by tubes from both gametangia; fertile cells
cylindric. Zygospores ellipsoid, with sharply rounded poles; median
spore wall smooth and brown; 32-40, in diameter, 50-80, long.
In an alkaline bog lake. Wis.
Spirogyra gracilis (Hass.) Kuetzing 1849, p. 438
Filaments of rather stout cells, 16-24, in diameter and up to 5
times the diameter in length, with plane end walls; chloroplast
solitary, making 1% to 3 turns. Conjugation scalariform by tubes from
both gametangia; sporangium inflated on the conjugation side only.
Zygospores ellipsoid; median spore wall smooth; 27-30» in diameter
and up to 60, long.
Mich.
Spirogyra gratiana Transeau 1938, p. 528
Pl. 74, Fig. 9
Filaments of elongate-cylindric cells, 28-33, in diameter, 144400»
long, with replicate end walls; chloroplasts (2)-3-(4). Conjugation
lateral or scalariform by tubes from both gametangia; fertile cells
cylindric or merely enlarged. Zygospores ellipsoid or cylindric-
ellipsoid; median spore wall smooth and yellow; 35-47, in diameter,
108-223, long.
Rock pool from north shore of Lake Superior.
Spirogyra Grevilleana ( Hass.) Kuetzing 1849, p. 438
Pl. 74, Fig. 11
Filaments of rather slender cells, 21-25—-(28) in diameter and
up to 10 times the diameter in length, with replicate end walls;
chloroplast solitary (rarely 2 in each cell), making 4-5 (up to 9)
turns. Conjugation scalariform, the tubes formed from the male
gametangium only; fertile cells inflated on the conjugation side.
Zygospores ovate; median spore wall smooth; 30-36, in diameter
and up to 214 times the diameter in length.
Mich.
Spirogyra inconstans Collins 1912, p. 74
Filaments of rather slender cells, 30u in diameter and up to 15
times the diameter in length, with replicate end walls; chloroplasts
8-4 (rarely only 2), making 1 to 3 turns. Conjugation scalariform
[ 315 ]
by tubes from both gametangia; fertile cells inflated. Zygospores
ellipsoid; median wall reticulate; 45-75» in diameter and up to
125y long.
Mich.
Spirogyra inflata (Vauch.) Kuetzing 1843, p. 279
Filaments of rather slender cells, 15-20» in diameter and up to
§ times the diameter in length, with replicate end walls; chloroplast
solitary (rarely 2), making 3 to 8 turns. Conjugation scalariform by
tubes from both gametangia; fertile cells inflated, fusiform. Zygo-
spores ellipsoid; median spore wall smooth; 42-48» in diameter and
up to 96, long.
Mich., Wis.
Spirogyra Juergensii Kuetzing 1845, p. 222
PlN713, Figs. 7,/8
Filaments of moderately stout, long or short cylindrical cells,
24-26-(30)y in diameter, 60-125, long, with plane end walls; chloro-
plast solitary, making 2 to 4 turns. Conjugation by tubes from both
gametangia; fertile cells cylindric. Zygospores ellipsoid; median
spore wall smooth and brown; 28-30-(33) in diameter, 40-75, long.
Floating mats in a marsh; in swamps and ditches. Mich., Wis.
Spirogyra jugalis (Fl. Dan.) Kuetzing 1845, p. 223
Filaments of large, stout cells, 90-100 in diameter, 1-114 times
the diameter in length, with plane end walls; chloroplasts 3-4,
making 1 to 2 turns. Conjugation scalariform by tubes from both
gametangia; fertile cells cylindric. Zygospores ellipsoid or cylindric-
ellipsoid; wall layers smooth; 87-108, in diameter and 114 times the
diameter in length.
Mich.
Spirogyra laxa Kuetzing 1849, p. 438
Filaments of rather stout cells, 30-33-( 40) in diameter and up to
230» long, with replicate end walls; chloroplast solitary, making
3 to 5 turns. Conjugation by tubes from both gametangia; fertile
cells cylindric. Zygospores ellipsoid; median spore wall smooth and
yellow; 30-33, in diameter, 60-82» long.
Mich.
Spirogyra longata (Vauch.) Kuetzing 1848, p. 279
Filaments of moderately stout cells, 20-36 in diameter and up
to 10 times the diameter in length, with plane end walls; chloroplast
solitary, making 2 to 5 turns; conjugation by tubes from both game-
[ 316 ]
tangia; fertile cells cylindric. Zygospores ovate or elongate-ovate;
median spore wall smooth but with a longitudinal suture, brownish;
30—(38) in diameter, 50—(83), long.
Mich.
Spirogyra majuscula Kuetzing 1849, p. 441
Pl. 74, Fig. 10
Filaments of stout cells, 50-80 in diameter, 80-500 long, with
plane end walls; chloroplasts 3-8, nearly straight or making less
than 14 turn. Conjugation by tubes from both gametangia; fertile
cells cylindric (sometimes slightly swollen). Zygospores lenticular
or spheroidal, laterally compressed; median spore wall smooth and
brown; 57-72» in diameter, 45-60 wide.
Mich.
Spirogyra maxima ( Hass.) Wittrock 1882, p. 57
Filaments of rather stout, short-cylindric cells (118)-145-153,
in diameter, with plane end walls; chloroplasts 6-8, making 14 to %4
turn. Conjugation scalariform by tubes from both gametangia; fertile
cells cylindric. Zygospores compressed-globose or lentil-shaped;
median spore wall finely reticulate; 100-120» in diameter, 70-95,
wide.
In an alkaline bog lake. Mich., Wis.
Spirogyra micropunctata Transeau 1915, p. 27
Pl (3, Big: 9
Filaments of fairly stout cells, 30-33-(36) in diameter, 108—114—
(300) long, with plane end walls; chloroplast solitary, making 2 to 4
turns. Conjugation scalariform by tubes from the male gametangium
only; fertile cells becoming slightly inflated. Zygospores ellipsoid,
the poles broadly rounded; median spore wall finely and densely
punctate; 37-42, in diameter, 57-70-( 100)» long.
In bogs and ditches. Mich.
Spirogyra mirabilis ( Hass.) Kuetzing 1849, p. 438
PL 7 7ebige |
Filaments of slender cells, 24—26-(27), in diameter and up to 10
times the diameter in length, with plane end walls; chloroplast soli-
tary, making 4 to 7 turns. Conjugation by tubes from both game-
tangia; fertile cells inflated. Zygospores ovate to ellipsoid; median
spore wall smooth and brown; 24-29, in diameter, 50-83, long.
Mich.
[ 317 ]
Spirogyra nitida ( Dillw.) Link 1833, p. 262
Pl. 73, Fig. 10
Filaments of rather stout cells, 60-80, in diameter, 90-166—(170) »
long, with plane end walls; chloroplasts 3-5, making 44 to 11% turns.
Conjugation by tubes from both gametangia; fertile cells cylindric.
Zygospores ellipsoid or cylindric-ellipsoid, with sharply rounded
poles; median spore wall smooth and brown; 60-77-(85)p in diam-
eter, 90-118—( 170)» long.
Tychoplankter; in shallow water of lakes and marshes. Mich., Wis.
Spirogyra novae-angliae Transeau 1915, p. 26
Pl. 75, Figs. 1-3
Filaments of rather stout cells, 49-60, in diameter, 140—-240-(390)
long, with plane end walls; chloroplasts 3-5, broad, making 1% to 4
turns. Conjugation by tubes from both gametangia; fertile cells
cylindric. Zygospores ovate to ovate-ellipsoid; median spore wall
irregularly reticulate and brown; 50-60, in diameter, 82-92-( 120)
long.
Forming sparse floating clots in several lakes. Mich., Wis.
Spirogyra orientalis West & West 1907, p. 186
Vegetative cells 30-31, in diameter, 90-160, long, with plane end
walls; chloroplasts 3, making 1 to 1% turns. Conjugation scalariform
by tubes from both gametangia; fertile cells inflated. Zygospores
ellipsoid; median spore wall finely scrobiculate; 32-42, in diameter,
61-67 long.
Mich.
Spirogyra porangabae Transeau 1938, p. 525
Pl. 77, Figs. 2,3
Vegetative cells 11-14.5, in diameter, 65-145p long, with plane
end walls; chloroplast solitary, making 4 to 9 turns. Conjugation
scalariform by tubes from both gametangia; fertile cells slightly
inflated (or merely enlarged to contain the spore). Zygospores
ellipsoid; median spore wall irregularly punctate when mature,
yellow; 21-27, in diameter, 47-54, long.
Mich.
Spirogyra porticalis (Muell.) Cleve 1868, p. 22
Pl. 75, Fig. 10
Filaments of rather stout cells, 40-50y in diameter, 68-200» long,
with plane end walls; chloroplast solitary, making 3 to 4 turns.
Conjugation scalariform by tubes from both gametangia; fertile
[ 318 ]
cells sometimes inflated. Zygospores ovate to subglobose-ovate;
median spore wall smooth and yellow; 38-50, in diameter, 50-83.
long.
Coe in shallow water of lakes, swamps, and roadside ditches.
Mich., Wis.
Spirogyra pratensis Transeau 1914, p. 292
Pl. 75, Figs. 4-6
Filaments of rather slender cells, 17-20, in diameter, 80-95-(240).
long, with plane end walls; chloroplast solitary (rarely 2), making
1 to 8 turns. Conjugation by tubes from both gametangia; fertile
colls inflated. Zygospores ellipsoid to subcylindric-ovate; median
spore wall smooth, yellow at maturity; 24-36, in diameter, 50-60-
(70) » long.
In a small pooled stream. Mich.
Spirogyra protecta Wood 1872, p. 165
Vegetative cells 32-36-(44)» in diameter, 120-475,» long, with
replicate end walls; chloroplast solitary making 4 to 5 turns. Con-
jugation by tubes from both gametangia; fertile cells cylindric or
slightly enlarged, sterile cells becoming inflated during conjugation.
Zygospores ovate or cylindric-ovate; median spore wall smooth
and yellow, inner scrobiculate; 36—42—(50)y in diameter, 66—
130, long.
Mich.
Spirogyra pseudofloridana Prescott 1944, p. 360
Pl. 75, Figs. 7-9
Filaments of stout cells, 51-60, in diameter and 3-5 times the
diameter in length, with plane end walls; chloroplasts 4 (rarely 5),
narrow, making 14 to 1% loose turns. Conjugation by geniculate
bending of filaments, without tubes being formed; gametangia
becoming shortened and thickened and apparently cut off from
vegetative cells; fertile cells becoming slightly inflated. Zygospores
ellipsoid, with narrowly rounded poles; median spore wall rough-
ened with irregular granulations and wrinkles (not regularly re-
ticulate), brown; 63-70, in diameter, 100-120, long.
This species should be compared with S. illinoisensis Transeau and
S. floridana Transeau. It is smaller than the former and has fewer
chloroplasts. From the latter it differs chiefly in the decoration of
the mesospore.
Floating in a lagoon. Wis.
Spirogyra reflexa Transeau 1915, p. 28
Vegetative cells 30-40, in diameter, 120-300, long, with plane end
walls; chloroplast solitary, making 3 to 8 turns. Conjugation by tubes
[ 319 ]
from the male gametangia only; fertile cells grouped, in series of 2-4.
Zygospores ellipsoid; median spore wall smooth and yellow-brown;
44-54 in diameter, 90-150, long.
Mich.
Spirogyra rhizobrachialis Jao 1936a, p. 57
Pl. 76, Figs. 1, 2
Filaments of rather stout cells (40)—45-59, in diameter, 114-240,
long, with plane end walls; chloroplasts 3-5, crenate and deeply
toothed on the margins, making 11% to 21% turns. Conjugation by
tubes from both gametangia; fertile cells cylindric, sterile cells fre-
quently forming tubes which develop highly branched rhizoidal
processes at their ends. Zygospores ellipsoid; median spore wall
irregularly and coarsely reticulate, brown; (38 )—40-62, in diameter,
111 be long.
Our specimens agree closely with this species in habit of growth
and spore characters, but vary in dimensions from the original
description.
Bright green cottony masses in soft water lakes. Wis.
Spirogyra rivularis ( Hass.) Rabenhorst 1868, p. 243
Vegetative cells 36-41, in diameter, 100-400, long, with plane end
walls; chloroplasts 2-3, making 2% to 314 turns. Conjugation by
tubes from both gametangia; fertile cells cylindric. Zygospores ellip-
soid or cylindric-ellipsoid; median spore wall smooth.
Mich.
Spirogyra scrobiculata ( Stock.) Czurda 1932, p. 182
Pl. 76, Figs. 3, 4
Filaments of short cells, 30-34-(40), in diameter, (30)-90-136,
long, with plane end walls; chloroplast solitary, making 1 to 5 turns.
Conjugation by tubes from both gametangia, the fertile cells inflated
on the conjugating side; zygospores ellipsoid, median spore wall
deeply pitted and brown; 33-35-(38), in diameter, 44—50-(68) long.
Among other algae in swamps. Mich., Wis.
Spirogyra singularis Nordstedt 1880, p. 23
Vegetative cells 29-39, in diameter, with plane end walls; chloro-
plast solitary. Conjugation by tubes from both gametangia; fertile
cells cylindric. Zygospores ellipsoid or cylindric-ellipsoid, not later-
ally compressed; median spore wall smooth; 27-37 in diameter.
Mich.
[ 320 ]
Spirogyra Spreeiana Rabenhorst 1863, Algen No. 988
Pl. 77, Fig. 9
Vegetative cells 18-21-(25), in diameter and up to 25 times the
diameter in length; end walls replicate; chloroplast solitary, mak-
ing 11/2 to 4 turns, Conjugation tubes formed from the male
gametangia only; fertile cells inflated on both sides. Zygospores
ellipsoid, median spore wall smooth and yellowish; 30—36, in
diameter, 55—100. long.
Mich.
Spirogyra stictica (Engl. Bot.) Wille 1884, p. 34
Pl. 76, Figs. 5-7
Filaments of short or long cells, 38-56 in diameter, 80-300p long,
with plane end walls; chloroplasts 2-6, straight or making 14 turn,
Conjugation by geniculate bending of the filaments; connecting
tubes not formed; the fertile cells becoming slightly swollen. Zygo-
spores ellipsoid; median spore wall smooth; 41-64, in diameter,
75-118» long.
In shallow water of lake margins, and in swamps. Mich., Wis.
Spirogyra subsalsa Kuetzing 1845, p. 222
Pl. 73, Figs. 1-3
Filaments of slender cells 26-28. in diameter, (35)-148y long,
with plane end walls; chloroplast solitary, making 114 to 3 turns.
Conjugation by tubes from both gametangia; fertile cells becoming
slightly swollen. Zygospores ellipsoid; median spore wall smooth,
inner irregularly reticulate (?), and brown; (18)—33—35n in
diameter, (30)—55—59, long.
This species should be compared with S. esthonica (Skuja)
Czurda and S. daedalea Lag., from which two species it differs in
fundamental details of the spore characters.
In swamps and other shallow water habitats. Wis.
Spirogyra suecica (Borge) Transeau 1934a, p. 420
Vegetative cells 26-29. in diameter, 80-175, long, with plane
end walls; chloroplast solitary. Conjugation by tubes from both
gametangia; fertile cells inflated on both sides. Zygospores ovate;
median spore wall smooth; 32-39, in diameter, 38-60, long.
Mich.
Spirogyra sulcata Blum 1943, p. 783
Filaments of rather stout cells 837-46y in diameter, 50-160, long,
with plane end walls; chloroplast solitary (rarely 2), making 2 to 5
turns. Conjugation by tubes from both gametangia, which are
[ 321 ]
shortened, the receiving cell becoming somewhat swollen. Zygo-
spores ovate; median spore wall reticulate and brown; 43-46, in
diameter, 52-62» long.
Wis.
Spirogyra tenuissima ( Hass.) Kuetzing 1849, p. 437
Vegetative cells (8)-9-12-(15)y in diameter, 4-12 times the diam-
eter in length with replicate end walls; chloroplast solitary, making 3
to 514 turns. Conjugation by tubes from both gametangia; fertile
cells fusiform, inflated. Zygospores ellipsoid; median spore wall
smooth and yellowish; 30, in diameter.
Mich.
Spirogyra Teodoresci Transeau 1934a, p. 420
Vegetative cells 23-30, in diameter, 42-90p long, with plane end
walls; chloroplast solitary, making 1 to 5 turns. Conjugation by tubes
from both gametangia; fertile cells greatly inflated on the conjugat-
ing side. Zygospores ellipsoid, varying to ovate or globose; median
spore wall smooth; 26-33, in diameter, 45-55y. long.
Mich.
Spirogyra triplicata (Collins ) Transeau 1944, p. 243
Vegetative cells 34-40(48), in diameter, 2-4 times the diameter
in length, with plane end walls; chloroplasts 3, making 1 to 2 turns.
Conjugation by tubes from both gametangia; fertile cells cylindric.
Zy gospores ovate to subglobose, not compressed; median spore wall
smooth; 34-48, in diameter, 48-54 long.
Mich.
Spirogyra varians ( Hass.) Kuetzing 1849, p. 439
Ble 76 yHigs: Let
Filaments of short cells, (28)-33-(40)» in diameter, 51-85-(120)
long, with plane end walls; chloroplast solitary, making 1% to 4 turns.
Conjugation by tubes from both gametangia; fertile cells inflated on
the conjugation side only. Zygospores ellipsoid or ovate-ellipsoid;
median spore wall smooth; 32-40, in diameter, 50-63-( 100) long.
Mich.
Spirogyra Weberi Kuetzing 1843, p. 279
Pl. 76, Figs. 8-10
Filaments of long cells, 19-30» in diameter, 80-480, long, with
replicate end walls; chloroplast solitary, broad, making 3 to 614 turns.
Conjugation by tubes from both gametangia; fertile cells cylindric.
Zy gospores cylindric-ovate; median spore wall smooth and brown;
21-25 in diameter, 30-95, long.
This species has never been found in pure growth; it seems always
[ 322 |
to be mixed with other filamentous algae. The unusually long,
slender cells and the long ovate spores are distinctive features. ,
Entangled among other algae in many lakes and swamps; common.
Mich., Wis.
ZYGNEMA C. A. Agardh 1824, p. 77
Unbranched filaments of short or long cylindrical cells with plane
end walls, inclosed by a soft (usually) mucilaginous sheath, rarely
with irregular rhizoidal outgrowths of a few cells when in contact
with the substrate; chloroplasts 2 (rarely 4) axial, stellate masses,
each containing a large central pyrenoid with a conspicuous starch
sheath. Conjugation mostly scalariform, with the zygospores formed
in the connecting tube, or rarely in one of the gametangia, but not
cut off by membranes from the gametangial cells. Zygospores spheri-
cal, ovate, or ellipsoid, with a thick, 3-layered wall, the outer and
middle layers variously sculptured with scrobiculations and puncta-
tions. Asexual reproduction by aplanospores and akinetes.
The genus Zygnema contains about 85 known species, and many
more of these certainly occur in our region than can be listed now.
Numerous collections of Zygema were made in the sterile condition
and are, therefore, unidentifiable. One species was invariably found
in soft water lakes attached about the culms of Scirpus spp., where
it formed pale green, cottony masses. Although this species was
collected repeatedly at several different seasons no fruiting speci-
mens were found. This is interpreted as having a distinct ecological
significance, and several possible explanations present themselves.
One of these has to do with water chemistry. Species of both
Zygnemataceae and Oedogoniaceae were found to flourish vegeta-
tively in soft water lakes but were scarcely ever collected in a
fruiting condition. In hard water lakes or in shallow ponds where
there was a high concentration of organic matter and organic acids,
these plants are more luxuriant and fruit abundantly.
Key to the Species
1. Zygospores not formed; conjugation unknown; reproduction by
aplanospores; vegetative cells 44-54 in diameter. Z. sterile
1. Zygospores formed by conjugation; aplanospores present
orbabsent; vegetative cells smaller 02 so 9)
peeopore wall bilge when mature: ole! tiles bei 3
2. Spore wall yellow, yellow-brown, or colorless when mature... 6
3. Spores formed in one of the gametangia________________. Z. chalybeospermum
3. Spores formed in the conjugation tube, extending
mao tue, Carmietan pia oro bsesen econ eas | ae ee 4
aeeNiedian, ‘Spore wall, ‘smootlal.7) 5.000)... ade isi cetsteane nee. Z. cyanosporum
Paiccian, spore «wall: punctate! oy 08 ogy) xcen he. ab aid a teeta eee 5
5. Median spore wall coarsely punctate, 33—36y in
GAM CLE Ie ces ss se nnaek ust saccem ioar cea! teehee aay eae ae Z. synadelphum
5. Median spore wall finely punctate;
Spores 2026 sin diameter, tA ae ee ee ete eee ee Z. carinatum
6. Spores formed mostly within the conjugating tube 9
6) Spores) formed in ome Ob the (ametam gia weeme enone Sees ec 7
7. Vegetative cells 20-24 in diameter; gametangia
inflated and shortened; spore wall smooth =. Z. leiospermum
7. Vegetative cells larger in diameter; gametangia
cylindricalor inflatedyonlyon-one side | 9 8
8: Mediant-wall"ofizygospore: smooths = Z. insigne
8: iMediantspore; walljscrobiculate:22%.. 1. = ee ee Z. stellinum
OL \Vegetativescells 24-40. sim (diameter). 2. ee 10
Ol Wevetative cells: 14-20 ini diameter. a. ke ee ee Il
10. Vegetative cells 30-40. in diameter; spores 35-50y in diameter,
wali with pitsy2=S-imt diameter ses seu se eee ee Z. pectinatum
10. Vegetative cells 24-33 in diameter; spores 24—32u in diameter,
wall with pits less than 2u in diameter —___._____________ _._ Z. conspicuum
11. Median spore wall minutely punctate —..____________ Z. micropunctatum
Ie Mediantspore; -walliscrobiculate === se eee Z. decussatum
Zygnema carinatum Taft in Transeau, Tiffany, Taft,
and Li 1934, p. 210
Pl oa bige ial
Vegetative cells 16-18, in diameter, 33-36, long; fertile cells not
inflated. Zygospores formed in the tube; compressed-globose, ovate,
or top-shaped, compressed at right angles to the tube; median spore
wall blue and punctate, with a conspicuous transverse suture; 23-26
in diameter, 29-33 long. Sporangium finally encased in a thick
pectic layer.
Mich.
Zygnema chalybeospermum Hansgirg 1892, p. 243
Pl. 74, Fig. 2
Vegetative cells 24-27, in diameter and up to 3 times the diameter
in length; fertile cells cylindrical (shortened). Zygospores formed
in one of the gametangia; globose or broadly ovate; median wall
blue and smooth; 30-35, in diameter, 30-38, long.
Mich.
Zygnema conspicuum ( Hass.) Transeau 1934, p. 208
Vegetative cells (18)-22-27-(33) in diameter, 50-90—-( 100), long;
fertile cells not inflated. Zygospores formed in the tube; globose or
ovate; median wall brown and rather coarsely pitted, the pits 1.5-2
in diameter; the spores 24-32, in diameter, 26-33, long.
Mich.
[ 324 ]
Zygnema cyanosporum Cleve 1869, p. 28
Vegetative cells (17)-20-(27), in diameter and up to 9 times the
diameter in length; fertile cells not inflated. Zygospores formed in
the tube; globose or depressed-globose, compressed at right angles
to the tube; median layer blue and smooth; 34—40, in diameter.
Mich.
Zygnema decussatum (Vauch.) Transeau 1914, p. 290
Vegetative cells 18-20, in diameter and up to 100, long, the wall
without a thick layer of mucilage; fertile cells not inflated. Zy go-
spores formed in the tube; globose or depressed-globose; median
spore wall brown and scrobiculate; 27-30 in diameter.
Mich.
Zygnema insigne ( Hass.) Kuetzing 1849, p. 444
Vegetative cells 26-30. in diameter, 1-2 times the diameter in
length; fertile cells cylindrical or inflated on one side only. Zygo-
spores formed in one of the gametangia; subglobose to ovate; median
wall brown and smooth; 32, in diameter, or (ovate spores) 26y in
diameter, 32, long.
Mich.
Zygnema leiospermum DeBary 1858, p. 77
PITS 4 Bigs
Vegetative cells 20-24, in diameter, quadrate; fertile cells enlarged
but not distinctly inflated. Zygospores formed in one of the game-
tangia; globose; median wall brown and smooth; 23-30, in diameter.
Mich.
Zygnema micropunctatum Transeau 1934, p: 210
Pl. 78,’ Fig. 12
Vegetative cells 14-16 in diameter, 24-52 long; fertile cells
not inflated. Zygospores formed in the tube; depressed-globose or
ovate, compressed at right angles to the conjugation tube; median
wall yellow-brown and minutely punctate; 28-32, in diameter,
3640, long.
Mich.
Zygnema pectinatum (Vauch.) C. A. Agardh 1817, p. 102
Pl. 69, Figs. 9, 10
Filaments forming light green, cottony masses; vegetative eells
30-37-(40) in diameter, up to 80» long, usually inclosed by a soft
mucilaginous sheath; fertile cells not inflated. Zygospores formed
[ 325 ]
in the tube; globose; median spore wall brown and pitted; 35-50,
in diameter.
Rare in a few lakes; forming floating masses among larger vege-
tation or entangled about the culms of rushes in shallow water,
Mich., Wis.
Zygnema stellinum (Vauch.) C. A. Agardh 1824, p. 77
Filaments forming green, mucilaginous masses, floating free or
sometimes in pooled seeps on banks; vegetative cells (25 )-28-26-
(40) in diameter, quadrate or up to 3 times the diameter in length
(mostly about 70,); fertile cells not inflated. Zygospores formed in
one of the gametangia; broadly ovate or oblong; median layer brown
and deeply pitted; 30-35, in diameter, 35-48, long.
In Sphagnum bogs and sloughs. Mich., Wis.
Zygnema sterile Transeau in Transeau,
Tiffany, Taft, & Li 1934, p. 212
Filaments scattered among other algae and seldom forming pure
masses; vegetative cells 44-54» in diameter, 22-69, long, with a
thick wall and inclosed by a firm pectic sheath which may be as
much as 15y in thickness, the sheath often deeply constricted at the
plane of the cross walls; cell contents very dense and so nearly
opaque that the individual chloroplasts can scarcely be discerned.
Conjugation not known; reproduction by thick-walled, scrobiculate
akinetes which fill the cell when mature.
Common; intermingled with other algae in shallow water, espe-
cially in small lakes and ponds where there is a high concentration
of decomposing organic matter. Mich., Wis.
Zygnema synadelphum Skuja 1926, p. 110
Pl. 74, Fig. 1
Vegetative cells 17-21 in diameter; fertile cells not inflated
Zygospores formed in the tube; globose, or compressed parallel with
the conjugation tube; median layer blue and scrobiculate; 33-36.
in diameter.
Mich.
ZYGNEMOPSIS (Skuja) Transeau 1934, p. 203
Filaments slender, composed usually of cylindrical cells which
are as much as 10 times their diameter in length; chloroplasts 2
steHate or cushion-like ‘masses, containing a single pyrenoid each.
Conjugation scalariform (between dissociated cells in some species
?), the gametangia persisting and becoming filled with cellulose-
[ 326 ]
pectic compounds, usually deposited in layers. Zygospores formed
in the enlarged conjugating tube, compressed-spheroid or quadrate
in front view, the median spore wall smooth or variously sculptured
and decorated, brownish in color.
This genus should be compared with Zygnema, especially those
species which have stellate chloroplasts. It is separated from that
genus chiefly by the presence of swollen and filled gametangia.
Key to the Species
ieevieretative cells 16—o2. 1m, diameter. ts ee 2)
SCO e Lani c eorsistialler ios ae 1 BONA SERS SIP AWN ee 3
2. Zygospores ovate or quadrangular-ovate,
median-spore wall ‘scrobiculate J es Z. decussata
2. Zygospores quadrate, outer wall densely punctate_.____ Z. spiralis
om Median and outer spore walls smooth =.) 4
Se Medianvor outer Spore| walls decorated 5
4. Vegetative cells 8-10—(12), in diameter, with
PRTOUNGEALCIMOEODOIAS{S oc. 22880 2 eb we le Z. minuta
4. Vegetative cells 10—12u in diameter, with
ig piate-vkevculovoplash = oe ne a ee eae Z. Tiffaniana
5. Median spore wall finely reticulate; spores 20-40u in diameter,
30—40y long; 1 chloroplast with 2 pyrenoids Z. americana
5. Median spore wall finely punctate; spores 14—24y in diameter,
20-27 long; 2 cushion-like chloroplasts in each cell Z. desmidioides
Zygnemopsis americana ( Trans.) Transeau in Transeau,
Tiffany, Taft, & Li 1934, p. 215
Vegetative cells 9-12» in diameter, 27-120, long; chloroplast with
2 pyrenoids. Zygospores formed in the tube but extending into the
gametangia; ovate or quadrangular-ovate in face view, the angles
retuse or rounded; median wall verrucose; 20-40. in diameter,
30-40 long.
Mich.
Zygnemopsis decussata (‘Trans.) Transeau in Transeau,
Tiffany, Taft, & Li 1934, p. 214
PI. 74, Fig. 3
Vegetative cells 16-20 in diameter, 24-50, long; chloroplast with
2 pyrenoids. Zygospores irregular in shape, or ovate to quadrate-
ovate, somewhat compressed parallel with the conjugation tube;
the angles various, either rounded, retuse, or extended; median spore
wall scrobiculate; 24-30 in diameter, 30-48, long.
Mich.
[ 827 ]
Zygnemopsis desmidioides (West & West) Transeau in
Transeau, Tiffany, Taft, & Li 1934, p. 215
Pl. 69, Fig. 8
Filaments short, slender, and fragile, much constricted at the
cross walls, composed of cylindrical cells, broadly rounded at the
apices, 8-llp in diameter, 25-40, long. Zygospores rectangular in
front view, broadly ellipsoid in side view; the median wall finely
and densely punctate; 14-24, in diameter, 20-27-(30)» in long
dimension. Gametangia persisting about the spore as 4 horn-like
processes filled with pectic compounds.
Rare; in shallow water of swamps; lake margins. Mich., Wis.
Zygnemopsis minuta Randhawa 1937, p. 312
Vegetative cells 8-10. in diameter, 36-46» long; chloroplasts 2
irregular cushion-like bodies. Reproduction mostly by lenticular
aplanospores. Zygospores quadrate in a 4-lobed sporangium (some-
times 3-lobed), formed by remains of gametangia; median spore
wall brown and smooth; 22—24, in diameter. Conjugation usually
between dissociated cells.
Mich.
Zygnemopsis spiralis (Fritsch ) Transeau in Transeau,
Tiffany ,Taft, & Li 1934, p. 214
PIS69) Migs
Filaments long, composed of short cylindrical cells, 17-22» in
diameter and up to 130, long; chloroplasts 2 stellate bodies. Zygo-
spores quadrate in outline, formed in the enlarged connecting tube
but extending into the gametangial cells which form horn-like
enlargements; outer spore wall brown and densely punctate; 30-36,
in diameter, 48-54, in long dimension.
Mich., Wis.
Zygnemopsis Tiffaniana Transeau 1944, p. 244
Pl. 74, Fig. 4
Vegetative cells 10-12 in diameter, 30-60, long; chloroplasts
with 2 pyrenoids. Zygospore quadrate, the margins either retuse or
straight to angles which may be produced or retuse (concave );
median spore wall smooth; 20-24, in diameter, 28-324 long. Con-
jugation frequently between dissociated cells.
Mich.
[ 328 ]
ZYGOGONIUM Kuetzing 1843, p. 280
Filaments of short-cylindric or slightly tumid cells with lateral
branches, either rhizoidal or several cells in length. Chloroplasts
cushion- or pad-like, 2 in a cell, or appearing as 1 duplex body
with an interconnecting narrow band; a pyrenoid in each chloroplast;
at times the chloroplast showing short radiate processes similar to
Zygnema; nucleus in the bridge between the 2 chloroplasts; cyto-
plasm usually colorless but sometimes purplish, becoming brown.
Conjugation lateral or scalariform by protuberances from both
gametangia; only part of the cell contents serving as a gamete.
Zygospore ovate, in a sporangium which is formed between the two
gametangia and which splits along a median line; spore wall smooth
or decorated; gametangia not becoming filled with pectic substances
but with granular residues, Reproduction also by akinetes and
aplanospores (more common than zygospores ).
Zygogonium ericetorum Kuetzing 1845, p. 224
Pl. 78, Figs. 8-10
Filaments with cells 15-24, in diameter and 14--114,-(4) times the
diameter in length, cylindrical or slightly constricted at the cross
walls; cell walls thick; chloroplasts, cytoplasm, and conjugation as
described for the genus; zygospore ovate or globose, 20-25, in
diameter, the median spore wall smooth.
In shallow water of Black Lake, Michigan; on damp soil and tree
trunks arising from water along lake margin.
CLASS CHAROPHYCEAE
This unique group of plants occupies an isolated position from a
taxonomic point of view. They have no known ancestors nor have
they given rise to other living plant forms according to present
information. They are alga-like in their reproductive habits and
because of their pigmentation there is ample justification for giving
them a place in the Chlorophyta. In many characteristics they are
quite unlike the green algae, however, and are so unique that in
some systems of classification the Charophyceae are considered to
be a separate division in the plant kingdom.
The Charophyceae are all macroscopic, having rhizoidal, erect
stem-like branches and whorls of secondary branches, or ‘leaves’.
They vary in height from 2 to 60 cm., growing erect or sprawling
in the bottom of lakes or slow-flowing streams. In many forms
vegetative proliferation occurs by stolons and special buds or
[ 329 ]
‘bulbils’ which develop on subterranean rhizoidal branches. Hence
it is customary to find members of this group in compact beds or
‘meadows.
The stem has definite nodes and internodes. From the former,
short branches of definite growth (the ‘leaves’) and longer branches
of unlimited growth develop. The leaves and secondary branches
may arise in whorls or in a dichotomous or trichotomous plan. The
chracteristic manner of growth in the Charophyceae is unique
among the Chlorophyta. A meristematic apical cell cuts off node
and internodal segments and from the former all lateral branches
and sex organs are produced. In one genus cortical cells also develop
from the node region and extend both anteriorly and posteriorly
along the internodal cell.
Reproduction is heterogamous and the sex organs are relatively
complex. There are both monoecious and dioecious species. The
oogonia are large, ovoid, or subglobose cells containing a single egg
and are inclosed by a definite number of spirally twisted corticating
cells which form a crown, the cornula, at the apex. The oogonia,
like the antheridia, are produced at a node of the stem or its leaves.
The antheridia are globose and usually smaller than the oogonia
but are frequently conspicuous because of their red color when
mature (as is also the oogonium in some species). The shell of the
antheridium is composed of a definite number of flat, shield-like
cells which have radiating lobes, these interlocking with lobes from
other cells. The shield cells bear internally a large number of multi-
cellular filaments, in each cell of which a swimming antherozoid is
produced. The oogonia may be above, below, or side by side with
the antheridia, depending upon the genus.
The reader is referred to Groves and Bullock-Webster (1920),
Fritsch (1935), and Smith (1938) for detailed discussions of the
morphology of the group and of the many characteristics which are
of taxonomic importance. It is a class which requires special
terminology and much careful study in dealing with its taxonomy.
There is 1 order and 1 family, divided into 2 clearly recognizable
tribes.
ORDER CHARALES
FAMILY CHARACEAE
In the taxonomy of this family the arrangement of the sex organs,
the presence or absence of cortical cells, and the number and
arrangement of these, are the major fundamental characteristics
upon which differentiations are made.
[ 330 ]
Key to the Tribes
Crown of oogonium composed of 5 cells; oogonium always above
the antheridium (in monoecious species) CHAREAE
Crown of oogonium composed of 10 cells (5 pairs, 2 cut off from
the tip of the cortical cells of the oogonium); oogonium below
or beside the antheridium; stem uncorticated_..-_-_ NITELLEAE
TRIBE NITELLEAE
In this tribe the stem bears whorls of short branches and 2 or
more branches of indefinite growth. The plan of branching is dicho-
tomous or trichotomous, and in many forms the secondary branches
or ‘leaves’ all terminate at about the same level and are usually less
than the internodes in length so that (especially in some species of
Nitella) a beaded appearance results. The plants are entirely un-
corticated and in most forms (particularly Nitella) they are limp
and flexible. The coronula (‘crown’) of the oogonium is composed
of 10 cells in 2 tiers at the ends of the 5 corticating cells of the
female organ. The antheridium may be vertical at the end of a
short stalk from the node of a fertile branchlet, or lateral (Tolypella)
and either sessile or stalked. In the monoecious species the oogonia
are below the antheridia (Nitella) or above and beside them
(Tolypella).
Key to the Genera
Branching regular and symmetrical; antheridia terminal and
vertical on a branchlet in the furcations;
oogoniaxbclomthe antheridiay 0 fs et Nitella
Branching irregular or not symmetrical, some branches longer
and giving a scraggly appearance; antheridia lateral in the
furcations; oogonia beside the antheridia or
appeaninpatosbesabove then: 2.02 ee Tolypella
NITELLA (C. A. Agardh) Leonhardi 1863, p. 69
Branches of unlimited growth, usually 2 at each node, the sex-
organ-bearing branches repeatedly forked and terminating at the
same level; antheridia terminal on a short stalk among the furcations
of the branchlets; oogonia lateral, either just below an antheridium,
or solitary on the node of a ‘leaf.’
Key to the Species
1. Plants small, 2-5—(8) cm. tall; ultimate divisions
omthe branchlets: (gays) po -ecliemies 2. oat a 2
1. Plants larger; ultimate divisions of the branchlets 1-celled_....- = 8
[ 331 ]
to
Whorls of verticils at the nodes globular in outline, gradually
decreasing in size toward the apex of the main
axis, forming minute tufts’ at the tip 222 N. tenuissima
. Whorls of verticils at the nodes spreading, not forming compact
globules, becoming compactly arranged at the anterior end and
bo
forming dense clusters cone-shaped in outline —_______ N. Batrachosperma
3. Plants monoecious Usp tat Rie IE MH cide ee ee N. flexilis
Se Plants. Gideciqus 222-2 ee ee ee N. opaca
Nitella Batrachosperma (Reichenb.) A. Braun 1847, p. 10
Pl. 78, Figs. 1-4
Plants minute and very delicate, up to 2 cm. (rarely 3 cm.) tall,
with several branches arising from a basal node; internodal cells in
the lower part of the thallus 2-3 times the length of the verticils,
which are in whorls of 8 at the node, and spreading, the branchlets
crowded toward the apex, forming a cone-shaped cluster at the tip;
branchlets once or twice divided, the ultimate rays 2-celled, the
terminal cell awl-shaped; monoecious; antheridia terminal on a
short stalk in the furcation of a ‘leaf, 0.135-0.210 mm. in diameter;
oogonia borne laterally to the antheridia and below them, with a
persistent coronula; oospore globose, 0.27-0.30 mm. in diameter,
dark brown in color, the outer membrane with reticulations.
This species is the smallest and the most delicate one in our
collections. Like N. tenuissima, it has a gray-green color, is often
found embedded in silt in the bottoms of shallow ponds and lagoons
and hence is easily overlooked.
Mich.
Nitella flexilis (L.) C. A. Agardh 1824, p. 124
Pl. 79; Figs: 1-3
Plants large (up to 30 cm. tall) and stout, with long internodes
(about 2 times longer than the branchlets), repeatedly branched,
especially long and sprawling stems in deep water; nodes bearing
whorls of 6-8 branchlets, with the sex-organ-bearing branchlets
usually shorter, forming dense clusters, the branchlets but little
divided, usually only one, the ultimate rays 1-celled and ordinarily
acuminate; sex organs monoecious, the oogonia 2-3, subglobose or
broadly ovoid, 0.55-0.75 mm. in diameter, 0.625-0.9 mm. long,
the investing cells showing 8—9 turns; antheridium 0.5-0.75 mm. in
diameter.
In shallow water of soft water lakes and Sphagnum bogs; from
10-12 meters. Mich., Wis.
[ 332 ]
Nitella opaca C. A. Agardh 1824, p. 124
Pl. 79, Figs. 4-10
Plants large and robust with very long internodes (2-4 times
longer than the branchlets); nodes bearing 6-7 branchlets which
may be either simple or once-divided, ultimate rays 1-celled and
mucronate; fertile branchlets crowded, forming heads; sex organs
dioecious, the oogonia 1-2, broadly ovoid, 0.5-0.565 mm. in diameter,
0.65-0.7 mm. long, the investing cells showing 7-9 turns, the crown
0.25-0.4 mm. high, deciduous; antheridia 0.65-0.75 mm. in diameter.
Common; a very luxuriantly growing, bushy plant, often forming
dense beds, especially in soft water lakes; sometimes found at a
depth of 5-8 meters. Mich., Wis.
Nitella tenuissima (Desv.) Kuetzing 1848, p. 319
Pl. 80, Figs. 1-7
Plants small, tufted, 2-8 cm. high, with several branches arising
from a single basal node; stem very slender, bearing whorls of 6
branchlets which are short, densely crowded and form glomerules,
giving a distinct beaded appearance to the plant; the branchlets
forking 3-4 times, ending in 2-celled rays; sex organs monoecious,
the oogonia spherical or broadly elliptic, about 260, (0.26 mm.) in
diameter, 400. (0.4 mm.) long, invested by corticating cells that
show 9 turns; antheridia about 0.175 mm. in diameter.
Like N. Batrachosperma, this species is often overlooked because
it grows in silt, with only the tips of the branches emergent.
Growing in shallow water on silty bottoms, mostly in soft water
or slightly acid lakes. Mich., Wis.
TOLYPELLA (A. Braun) Leonhardi 1863, p. 72
Thallus relatively coarse, (8)-10-25 cm. high, light green or gray-
green in color, usually irregularly branched, presenting a scraggly
appearance; sterile branches 6-16 in a verticil, of variable length;
fertile branches involving several long, and one head of short,
branchlets; internodes of principal filament and of primary laterals
long; uncorticated; primary laterals sparsely branched; branches
terminating in a series of unbranched ray cells which may be pointed
or bluntly rounded at the tip; monoecious (in our specimens), the
antheridia sessile or at the ends of short lateral branchlets in the
furcations; oogonia usually crowded, appearing to be above and
also beside the antheridia on the same node, formed either at the
base of a fertile branchlet or on one of the lower nodes, the coronula
persistent or not; oospore round in cross section, light to orange-
brown in color.
[ 333 ]
Tolypella intricata Leonhardi 1863, p. 32
Pl. 78, Figs. 5-7
Thallus 8-25 cm. tall, gray-green; sparsely branched with a few
primary branches and dense heads of fertile branchlets subtended
by laterals of unequal length; the primary ray including but few
nodes from which 2 or 8 lateral branches arise, simple or again
divided, the laterals but 8 or 4 cells in length, the terminal cell
sharp-pointed or sometimes bluntly rounded; fertile branchlets
densely clustered and including also long, coarse branchlets of
irregular length; the primary branch with 2 or 3 nodes, each bearing
3-(4) lateral branches, the ultimate rays of the fertile branches 3-
or 4-celled, the lateral branch rays branched at the first node and
again branching, sometimes also branching from the second node,
these branches simple if there are but 2 nodes in the branchlet;
antheridia sessile, up to 0.3 mm. in diameter, lateral at the nodes of
the fertile branchlets; oogonia at the base of or on the nodes of the
fertile branchlets, several together, appearing above or beside the
antheridia; oospore 0.3-0.318-(0.4)mm. in diameter, light brown
when mature, decorated with 10-11 ridges, the outer membrane
yellowish, thin, and granular.
In hard and semi-hard water lakes, in shallow water where there
is protection from wave action and strong currents. Mich.
TRIBE CHAREAE
In this tribe the stems usually have but a single branch of
unlimited growth arising from the nodes of the stem. The whorls
of branchlets are simple, having only short bracts or leaflets at
their nodes rather than bifurcations. In one genus, Chara, most
species are characterized by having the internodal cells of the stem
corticated. The sex organs may be monoecious or dioecious, in our
specimens (Chara) with the oogonium borne above the antheridium
in the monoecious species. The coronula of the oogonium in this
group is composed of but 5 cells, cut off from the tips of the spiral
corticating cells of the oogonium.
CHARA Linnaeus 1754, p. 491
These plants are usually stout and coarse of texture, when com-
pared with Nitella. They are frequently encrusted with lime and
thrive best in hard or semi-hard water lakes and slowly flowing
streams. It is this character which has earned for them the common
name of Stoneworts. The stem in most species is corticated by
elements which develop from the node cells in both directions along
[ 334 |
the internodal cell and so meet cortical cells from the node above
and below. The cortical cells in their development themselves cut
off small node cells. These show as small round units in the series;
often they are spiniferous. From the node cells of the corticating
cells secondary corticals may be cut off and grow down alongside
the primary elements. These may be more prominent than the
primary, or less so, a specific character of taxonomic value. Some-
times there are two such cells cut off, one on either side of the
primary cortical cell. The results of the behavior of the node cells
of the cortical elements are then: 1. The node cells may not produce
laterals and the cortical cells are rather large and equal in number
to the leaves, which are borne at the node of the stem. This
condition is known as haplostichous cortication. 2. If the node cell
of the cortical series cuts off one lateral so that the cortex is com-
posed of alternating primary and secondary cells the condition is
known as diplostichous, and there are twice as many cortical cells
as there are leaves at the stem node. 3. The node cells of the cortical
series may give rise to two laterals, one on either side, so that in
the circumference of the stem the primary cells alternate with two
secondary cortical cells, and there are three times as many cortical
cells as there are leaves in the whorl at the stem node. This condi-
tion is known as triplostichous. There are irregularities in these plans
of arrangement, so that it is often necessary to examine many stem
sections to obtain the necessary information for taxonomic consid-
erations. Rarely the stems are ecorticate.
In most forms, besides bearing a whorl of leaves, the stem node
is encircled by a single or double row of spine-like cells, the
stipulodes.
The nodes of the leaves may be smooth or they may bear leaflets
or bracts (bracteoles ). Some of these may be mere papillae, whereas
others at the same node may be much elongated, especially at fertile
nodes where there are usually 2 or 4 long bracts about the oogonium.
The last 1 to 4 cells of the leaves may be ecorticate and the general
form and arrangement of these cells at the tip, and the lateral
elements given off just below the uncorticated cells at the end of
the leaves are characteristics which are of taxonomic value also.
There are both monoecious and dioecious species. In the former
condition the oogonia are always borne above the antheridia, devel-
oping, however, from the same initial cell in the node of the
branchlet.
Only the more conspicuous species of Chara were collected, and
in the present treatment I have included one which has been
previously reported. Hence only a few of the many forms which
[ 335 ]
undoubtedly occur in the region are included. In order to make
an adequate study of this interesting group, dredging and other
special methods of collecting would be required. Many species of
Chara listed by Robinson (1906) occur in the range of this area,
but none are specifically referred to Michigan and Wisconsin. See
Allen (1888-1896), Robinson (l.c.), and Groves and Bullock-
Webster (1924) for the taxonomy of Chara.
Key to the Species
i, Siem wincomnerniedl (Sonar) 2
es Stemsscorticated (Corticatay) ie. ot 2 AA A eae eT os 3
2. Bracts about the oogonium distinctly shorter
(Haehair{davempanPstaurgenn am ibncaese meme Ae aces 1 AN ON eS ee a C. Braunii
2. Bracts about the oogonium as long as or
longersthan)thesmaturesinuit 262 Sie Ay Was ae ee C. Schweinitzii
3. Cortication haplostichous (see definition above )—______ C. canescens
34 Corticationsdiplastichoussor) triplostichous= 224. -- tt) ie ts Be 4
Ave Cortications G@iplostichOUS= 2
2. Flagella of equal length; lorica absent -___-----_-__ ISOCHRYSIDINEAE
2. Flagella of unequal length; protoplast
inclosed) by ia lorica 9
9. Cells twisted throughout their length >>> P. helikoides
9. Gells twisted only in the caudal portion —__________________. P. tortus
10. Cell with a short, straight, almost papilla-like caudus P. acuminatus
10. Cell with a conspicuous caudus, straight,
eurved, or strongly retle xec semerstaee cee 11
11% ‘Gell -with\ evenly undulate margins 98. P. crenulata
11. Cell with margin entire, irregularly undulate,
orenotched: unsymmetrical yiewel. ee See | Sat 12
12. Cell unsymmetrically fusiform, somewhat euglenoid P. asymmetrica
12. Cell ovoid or orbicular in outline, symmetrical or nearly so 13
[ 395 ]
13. Cell with a prominent dorsal flange, decidedly triangular when
seen in end view (cf. P. Swirenkoi, which is somewhat triangular) ____. 16
13. Cell without a dorsal flange, not triangular in end view___-_---_. 14
14 Marem’ of ‘cell’ with prominent notches 22 ee ee 15
14s. Margin-of, cell Gntinre 252.225 1) ly 8 ee 17
15. Cell with 1 or 2 lateral notches; 1 large
circular paramylon body —_-.... _.-.----- ss Mia VINE t P. pseudoswirenkoi
15. Cell with several notches in both sides; 1 large
auduseveral ‘stall paramylon) bodies== == ee P. Birgei
16. Cell with a strongly decurved caudus.___.____---.------------------- P. orbicularis
16. Cell with the caudus straight or only slightly
curved away from the longitudinal axis -______________ P. triqueter
Lier Gells p15=2 5 up inudiameter sss teow i ed ee ee el ee ee 18
24,
24.
«Cells. 80=50=(60)) i inadiaimetent 82S tel 8 ee ail
. Paramylon plates 2 large oval rings, at least
A thecell body im length. a2 See Sa ee ee ee ee P. alatus
/Paramylon:plates:smalier, 2.or'several === ee ee 19
. Cells distinctly twisted in the posterior part, just above the
caudus, where there is often a swelling; one side of
the’ cell much’ thicker than/the other == 23. P. Lemmermannii
. Cells not distinctly twisted in the posterior portion;
without a/swelling; above the caudus === 20
. Cell ovoid to ellipsoid, with a straight
or only slightly curved! caudus #2 = P. caudatus
. Cell broadly ovoid to orbicular, with a short
Caudus.curvingrto: the letee 2. es ee P. curvicauda
. Cell distinctly twisted in the posterior part just above the
caudus; paramylon bodies usually 2 large
and several ‘small: plates == ee P. Lemmermannii
. Cells not distinctly twisted above the caudus;
patamylon bodies usually 2 large sings ise ee 22
. Cell orbicular, broadest below the transverse median line;
caudus deflexed mostly to the right;
cell-angiilar in end View sas. Mie S00 ht eee 23
. Cell ovoid or nearly so, broadest at the
transverse median lines or above: ity 2. ee ee ee 24
. Cell twisting slightly into the caudus, which is
prominent and elongate, slightly deflexed P. pleuronectes
. Cell not twisting into the caudus, which
isnshort. and) sharply. detlexed . es ee ee P. Swirenkoi
Cell broadly ovoid or orbicular, with a strongly
curved caudus; cells 50-100u long —._-...---..-------------------------- P. orbicularis
Cells narrowly ovoid, somewhat unsymmetrical, with a nearly
straight caudus; cells up to 48 long P. anacoelus
Phacus acuminatus Stokes 1885a, p. 183
Pl. 88, Fig. 4
Cells suborbicular in outline, broadly rounded posteriorly, with
a short, blunt apiculation; periplast longitudinally striated; paramy-
lon bodies 1-2 ring-like discs; cells 20-22 in diameter, 23-25, long.
Plankter; in cedar swamp. Wis.
[ 396 ]
Phacus acuminatus var. Drezepolskii Skvortzow 1928, p. 113
[P. caudatus Ehrenberg ex Pochmann 1942, p. 146]
Pl. 88, Figs. 17, 18
Cells ellipsoid or ovoid, slightly produced posteriorly, sometimes
with the cell margins convolute, forming a short, sharp caudus;
periplast longitudinally striated; paramylon bodies 2 large discs;
cells 10-15, in diameter, 21-24, long.
In swamps and ditches. Wis.
Phacus alatus Klebs 1883, p. 312
Cells very broadly ovoid to nearly circular in outline, with a short
caudus which is strongly curved and twisted to the left (when the
cell is seen in ventral view); periplast longitudinally striated; para-
mylon bodies 2 large plates or rings which are at least 14 the cell
body in length, lateral and sometimes peripheral, one on either side
of the cell; cells (16)-19-22 in diameter, 19-24, long.
In a slough; among dense growths of filamentous algae. Wis.
Phacus anacoelus Stokes 1888, p. 91
Pl 87, Figs: 7, 6; Plr3s, Fig: 1
Cells broadly ovoid, narrowed abruptly posteriorly to form a short
caudus, which turns to the left (as seen in ventral view); paramylon
bodies 1-2 circular plates; lateral margins of cells with 2-3 creases
or folds, the membrane convex between the indentations; periplast
longitudinally striate; cells 32-36-(40) in diameter, 40-48, long.
Euplanktonic and tychoplanktonic. Wis.
Phacus anacoelus var. undulata Skvortzow 1928, p. 109
[Phacus undulatus Pochmann 1942, p. 191]
Pl, 87, Figes
Cells broadly ovoid, produced posteriorly into a long (or short)
sharply pointed caudus, oblique to the longitudinal axis of the cell,
anteriorly broadly rounded but slightly bilobed because of the
gullet groove; periplast longitudinally striated; margin of the cell
with 2-3 bulges; 1 large centrally located paramylon disc; cells
60-65, in diameter, 80-111, long.
Our specimens average much larger than the dimensions recorded
for this variety, but otherwise they are in agreement.
Planktonic; also found in swamps and ditches. Wis.
[ 397 ]
Phacus anacoelus var. undulata fa. major Prescott 1944, p. 366
PI. 89, Fig. 20
Cells broadly ovoid; ending posteriorly in a long obliquely directcd
caudus; margins of cell with a deep crease on either side, forming
2 broad bulges; cells much larger than in the typical form, 64y in
diameter, 111-115, long.
Euplankter. Wis.
Phacus asymmetrica Prescott 1944, p. 366
Pl. 88, Fig. 19
Cell irregularly ovoid-fusiform and slightly spiral in the posterior
and anterior portions; extended into a curved, bluntly-pointed cau-
dus posteriorly; narrowed anteriorly and with 2 irregular bulges on
either side of the apex; periplast finely striated longitudinally; para-
mylon bodies 2 thick twisted rings, usually lying transversely in the
cell; chloroplasts numerous small ovoid discs; cell 22-25, in diam-
eter, 50-53, long.
This species should be compared with Phacus Raciborski Drez.,
which is much more slender and more nearly symmetrical.
In a roadside fosse. Wis.
Phacus Birgei Prescott 1944, p. 367
Pl. 87, Fig. 11
Cell broadly ovoid, produced posteriorly to form a long tapering
caudus which is oblique to the longitudinal axis of the cell, broadly
rounded anteriorly; flagellum as long as the cell; periplast very
finely striated; margins of the cell sharply notched with 4 small
indentations on either side; paramylon bodies 1 large and numerous
small circular plates; chloroplasts many ovoid discs; pigment-spot
(?); cell 50-60, in diameter, 70-80, long.
In a small pond near Genoa City, Wisconsin.
Phacus caudatus Huebner 1886, p. 5
Pl. 87, Fig. 13
Cells ovoid-pyriform, spirally twisted, produced posteriorly to
form a straight, sharp caudus; broadly rounded anteriorly; periplast
longitudinally striated; 1 large, disc-like paramylon body; cells
15-27, in diameter, 30-50y long.
Euplanktonic and tychoplanktonic. Wis.
Phacus caudatus var. ovalis Drezepolski 1925, p. 266
Pl. 88, Fig. 18
Cells elongate-ovoid, with a short, blunt caudus; cells 18.54 in
diameter, 33.3» long; periplast smooth (?).
With the typical form. Wis.
[ 398 ]
Phacus chloroplastes Prescott 1944, p. 367
Pl. 87, Figs. 15, 16
Cells broadly pyriform; produced posteriorly to form a straight
or very slightly deflected caudus; broadly rounded anteriorly, with
a median papilla; periplast longitudinally striated; margin of the
cell entire; chloroplasts several parietal bands lying parallel with
the long axis of the cell; paramylon bodies 2 large thin rings or
slightly twisted bands lying lengthwise in the cell; eye-spot median,
in the apical region; cell 20-22, in diameter, 29-31, long.
This form should be compared with P. hispidula (Eichw.) Lemm.
Plankter; from an inlet of Trout Lake, Wisconsin.
Phacus chloroplastes fa. incisa Prescott 1944, p. 386
Pl. 88, Figs. 5-8
Cells pyriform or napiform in outline, tapering abruptly to a
long, straight sharp caudus; periplast longitudinally striated; margin
of the cell with 2 sharp notches on either side; cells 25-26p in diam-
eter, 38—40p long.
In cedar swamp. Wis.
Phacus crenulata Prescott 1944, p. 368
Pl. 88, Fig. 9
Cells ovoid-pyriform, posteriorly extended to form a gradually
tapering, sharp-pointed caudus; anterior end broadly rounded but
bilobed, with a convex papilla between the lobes; flagellum as long
as the cell or a little longer; margins of the cell distinctly crenulate
or undulate; periplast longitudinally striated with undulating lines;
paramylon bodies 2 circular discs; cells 14-15 in diameter, 34-36,
long.
This species should be compared with P. costata Conrad, which
has spiral entire striations rather than longitudinal wavy ones. The
anterior end is different in that species also. P. setosa var. crenata
Skv. has spiral striations.
Plankter; in a cedar swamp. Wis.
Phacus curvicauda Swirenko 1915a, p. 333
Pl. 87, Fig. 14; Pl. 88, Fig. 21
Cells broadly ovoid to suborbicular in outline, slightly spiral in
the posterior part, which is extended into a caudus that curves
obliquely to the left (when viewed from the ventral side); anterior
end broadly rounded; periplast longitudinally finely striated (or
[ 399 ]
smooth ?); paramylon bodies 2 large discs; chloroplasts numerous
ovoid bodies; cell 24-26y in diameter, (25)-—28-30, long.
Euplanktonic and tychoplanktonic. Wis.
Phacus helikoides Pochmann 1942, p. 212
Pl. 87, Fig. 9
Cells fusiform or elongate fusiform-pyriform, twisted’ throughout
their entire length (sometimes closely so), briefly narrowed anter-
iorly and bilobed, the lobes appearing in 2 planes when seen from
the side; tapering posteriorly to a spirally twisted, long, straight
caudus which is about 1% the cell body in length; margins of the cell
entire but with 2 or 3 bulges; periplast longitudinally and spirally
striated; 1 large circular paramylon body; cells 39-(40)—54» in
diameter, 70-120, long.
This species should be compared with P. tortus (Lemm.) Skv.,
which is broader and is twisted only in the posterior portion of the
cell.
Not uncommon in the plankton of lakes and ponds but most
frequently found in the tychoplankton of shallow water. Wis.
Phacus Lemmermannii (Swir.) Skvortzow 1928, p. 114
Pl. 88, Fig. 12
Cells broadly ellipsoid to ovoid, decidedly twisted in the posterior
portion (usually) and somewhat abruptly tapered to a short, sharp
caudus which turns to the right (when the cell is seen from the
ventral side); slightly retuse at the anterior pole and sometimes
rather narrowly rounded (in our specimens); paramylon bodies
either 2 moderately large rings or, more commonly, 2 larger rings
and many small circular plates; cell (19)-20-30, in diameter,
(27 )-32-45-( 47) » long.
Plankter; in sloughs and ponds. Wis.
Phacus longicauda (Ehrenb.) Dujardin 1841, p. 337
Pl, 37, Fig. 1
Cells broadly ovoid to pyriform, tapering gradually posteriorly
to form a long, straight, sharply pointed caudus; anteriorly broadly
rounded; periplast longitudinally striated; flagellum shorter than
the cell in length; paramylon body usually in the form of a single
large (or small) circular plate; cells 45-70» in diameter, 85-170n
long.
ace common in the euplankton and tychoplankton of lakes and
swamps. Mich., Wis.
[ 400 ]
Phacus Nordstedtii Lemmermann 1904, p. 125
Pl. 88, Fig. 1
Cells napiform, nearly spherical but with a long, straight, sharply
pointed caudus; broadly rounded anteriorly; periplast forming an
envelope widely separated from an elliptical protoplast, the periplast
spirally striated; paramylon bodies not observed; chloroplasts num-
erous ovoid indistinct discs; cells 18.54 in diameter, 36, long.
Our specimens are assigned here because of the cell shape and
periplast characteristics. Judging from the original description of
P. Nordstedtii, it was not clear to the author of the species whether
the species actually belonged to Phacus. Our specimens are much
smaller than the dimensions given for this species and perhaps
should be described as a new variety. This shouild be deferred,
however, until more is learned of their cytology.
Plankter; from a cedar swamp. Wis.
Phacus orbicularis Huebner 1886, p. 5
Pl. 87, Fig. 10
Cells orbicular in outline, with a short caudus curved to the right
(when seen in ventral view); broadly rounded anteriorly; periplast
finely striated longitudinally; flagellum as long as the body; para-
mylon bodies 2 disc-shaped plates; cells 39-45, in diameter, 60—70-
100, long.
Plankter; from a cedar swamp. Wis.
Phacus orbicularis var. caudatus Skzortzow 1928, p. 112
[P. platalea Drezepolski ex Pochmann 1942, p. 179]
Pl. 87, Fig.12; Pl. 88, Fig. 15
Cells broadly ovoid to nearly round in outline, spirally twisted,
extended posteriorly into a long, straight, sharply pointed caudus;
periplast longitudinally striated; paramylon bodies 1-2 (sometimes
several) large circular plates; cells 45-47, in diameter, 65-69, long.
With the typical form in a cedar swamp. Wis.
Phacus orbicularis var. Zmudae Namyslowski 1921
[P. circulatus Pochmann 1942, p. 177]
Pl. 88, Fig. 10
Cells orbicular in outline, produced posteriorly to form a short
caudus obliquely turned to the left (as seen in ventral view); peri-
plast longitudinally striated; cells 18.5-21 in diameter, 27-29 long.
In a roadside fosse. Wis.
[ 401 ]
Phacus pleuronectes (Muell.) Dujardin 1841, p. 336
Pl. 88, Fig. 16
Cells broadly ovoid to suborbicular in outline, slightly spiral and
produced posteriorly to form a stout, sharp-pointed caudus which
is obliquely turned to the right (when seen from the ventral side);
anterior end broadly rounded; periplast longitudinally striated;
flagellum as long as or longer than the body; paramylon bodies
1-2 ring-like discs; cells (30)-37-46.8-(50)u in diameter, (42)-
50-80—( 100) » long.
This is a common species in marginal waters of eutrophic lakes,
especially where protected from wave action; also frequent in ponds
and ditches. Mich., Wis.
Phacus pseudoswirenkoi Prescott 1944, p. 368
Pl. 85, Fig. 26; Pl. 87, Fig. 2; Pl. 88, Fig. 14
Cells orbicular in outline, abruptly narrowed posteriorly and
produced to form a short, sharp caudus which curves to the left
(when seen from the ventral side); anterior end broadly rounded;
flagellum about as long as the body; periplast longitudinally striated,
with a deep, sharp, lateral notch medianly located on the right
side (rarely one on the left side also); paramylon body a large,
circular plate; cells 30-33» in diameter, 37-40, long.
This species should be compared with P. Swirenkoi, a species
which is about the same size but which has entire margins and a
caudus which turns to the right.
Plankter; from a cedar swamp; in ponds and ditches. Wis.
Phacus pyrum (Ehrenb.) Stein 1878, III, Taf. 19, Figs. 51-54
Pl. 88, Fig. 22
Cells ovoid, narrowed gradually posteriorly to a long, straight,
finely pointed caudus; broadly rounded anteriorly, but with 2 pa-
pillae between which the flagellum emerges; periplast spirally
ribbed; paramylon bodies 2 ring-like plates, laterally situated; cells
(7)-15.6-21 in diameter, 27-30, long.
Euplanktonic and tychoplanktonic. Mich., Wis.
Phacus Segretii Allorge & Lefevre 1925, pp. 128, 129
Cells broadly ovoid or unsymmetrically orbicular in outline, with-
out a caudus; slightly narrowed anteriorly, with a prominent ventral
furrow; broadly rounded posteriorly; periplast longitudinally or
slightly spirally striated; paramylon bodies in the form of 1 large
and 1 smaller circular plate; cells 20-22» in diameter, 22—28p long.
Typical form not observed in our collections.
[ 402 ]
Phacus Segretii var. ovum Prescott 1944, p. 369
Pl. 88, Fig. 23
Cells larger than in the typical form, broadly ovoid; 28-30» in
diameter, 39-41, long.
In swamps. Wis.
Phacus Spirogyra Drezepolski 1925, pp. 234, 267
Cells unsymmetrically spherical or ovoid, with a sharply pointed
caudus arising from the broadly rounded posterior; periplast spirally
striated with rows of granules; cells 32, in diameter, 45, long, caudus
10, long.
Typical form not observed in our collections.
Phacus Spirogyra var. maxima Prescott 1944, p. 369
Pl. 87, Figs. 4-6
Cells ovoid to somewhat oblong, unsymmetrically spiral or merely
twisted once, abruptly narrowed posteriorly into a long straight or
curved caudus; broadly rounded anteriorly (narrowly rounded when
seen from the side), with a prominent median protrusion; periplast
longitudinally striated with spiral rows of granules; chloroplasts
numerous discs; paramylon bodies 2 large doughnut-shaped rings;
cells 35-40, in diameter, 70-80, long.
This species is peculiar in the shape of the cell body which is not
very much flattened. In side view it is narrower than when seen
from the front.
In a roadside fosse. Wis.
Phacus suecicus Lemmermann in Pascher
& Lemmermann 1913, p. 139
Pl. 88, Figs. 2,3
Cells broadly ellipsoid or ovate, but not quite symmetrical, with
a relatively long, sharp caudus which is slightly deflected; truncate
or slightly retuse at the anterior end but with a prominent, median,
collar-like papilla through which the flagellum extends; flagellum
as long as the cell body; cell planoconvex when seen from the side;
periplast longitudinally striated with rows of sharp granules; chloro-
plasts numerous circular discs; paramylon bodies 2 lateral and
peripheral plates or rods lying just within the periplast; cells (14)-
19-22, in diameter, 34-36, long, 6-11, thick.
Plankter; in a cedar swamp. Wis.
[ 403 ]
Phacus Swirenkoi Skvortzow 1928, p. 114
Pl. 88, Fig. 24
Cells orbicular in outline, slightly twisted posteriorly and extended
into a short, sharp caudus which turns obliquely to the right (when
seen from the ventral side); broadly rounded anteriorly; periplast
longitudinally striated; margin of the cell entire; paramylon bodies
2 large circular plates; cells 35y in diameter, 48—46y long.
Common in the plankton of lakes; in tychoplankton of bays and
in swamps. Wis.
Phacus tortus (Lemm.) Skvortzow 1928, p. 110
Pl. 88, Fig. 20
Cells broadly fusiform or napiform, broadest in the anterior third
of the cell, conically rounded at the anterior end, tapering and
spirally twisted in the posterior portion to form a long, straight
(rarely slightly curved) caudus; periplast with spiral striations;
paramylon bodies 1 or 2 large, centrally located circular plates;
flagellum 24 the length of the cell body; cells (38 )—40-50-(52) » in
diameter, 85-95-(112) » long.
In shallow water of many swamps and in small ponds. Wis.
Phacus triqueter (Ehrenb. ) Dujardin 1841, p. 338
Pl. 107, Figs. 4-6
Cells broadly ovoid, usually broadest below the median line,
broadly rounded and bilobed anteriorly, narrowed unsymmetrically
posteriorly to form a prominent, slightly deflected, sharply pointed
caudus; the dorsal surface with a high flange, thus making the cell
triangular in outline when seen from the end; a deep longitudinal
furrow on the ventral side; periplast longitudinally striated, the
striations extending slightly into the caudus; paramylon bodies 2
to several large rings (sometimes only 1); cells 30-45, in diameter,
37-68» long.
Tychoplankter. Wis.
LEPOCINCLIS Perty 1849, p. 28
Cells ovoid, ovate, elliptical or fusiform, sometimes nearly spheri-
cal, with a firm and usually spirally striated periplast, round in cross
section; posteriorly extended into an abruptly pointed tail-piece
(rarely gradually tapering); a gullet in the anterior end where there
arises a single flagellum that is once or twice the cell in length;
chloroplasts numerous parietal discs; pigment-spot laterally placed
[ 404 ]
in the anterior region; reserve food in the form of 2 large, lateral
paramylon rings, the 2 together sometimes nearly encircling the cell.
Species of this genus are usually found in company with other
euglenoids. They are, for the most part, not found in euplankton
but occur among dense growth of algae in shallow bays, swamps,
and in ponds. They nearly always appear in samples from water
which is rich in organic acids and nitrogenous substances.
The nature of the periplast decoration is of taxonomic value
because it varies according to species. This character is often ob-
scured by the density of cell contents, and it is necessary to manipu-
late a specimen so that it can be seen from various angles.
Key to the Species
1. Cells narrowly pyriform or narrowly ovoid,
oragtially wtapering, MOStETIOTLY® Site en. Fe L. acuta
1. Cells broadly ovoid, or broadly ellipsoid,
Wwitla@utwa lomGCatichis =e aepes net © 50) che cd 1h es ee ee 2
2. Cells ovoid, 39-58u long, with a short caudus L. fusiformis var. major
21 (Gellsisubplobese, ovoid; or! fusiform; ‘smaller 2S ea ee 3
8. Cells with a bipapillate protrusion at the anterior
end: trou which the fagelluny emergesi 22 4
a: Cellsswithout; a. bipapillate protrusion 3 = = ee ee 5
4, Cells broadly ovoid, 19-21 in diameter_._____________ L. glabra
4. Cells ellipsoid, or narrowly ovoid, 8-104 in diameter_______ L. sphagnophila
sells: iis li(jcwunciarmietet se sie Fv ES te 9 ee L. fusiformis
Ba Cells largery, 22-30 inidiameter 2 oe oie oe 8 es ee es 6
6. Cells 22—25u in diameter; flagellum emerging
aie (oven inudetalore Clateluoetn Sy Meh is FT ee See St eee re ee ee Ree ee L. ovum
6. Cells 28—30u in diameter; flagellum arising
subapically;to nearly Naterally, 0 ee L. Playfairiana
Lepocinclis acuta Prescott in Prescott, Silva, & Wade 1949, p. 89
Pl. 89, Figs. 8, 9
Cells ovoid-pyriform, tapering posteriorly to a long, sharply point-
ed caudus, slightly narrowed anteriorly and rounded at the apex;
periplast spirally striated downward to the right; flagellum about
as long as the body; paramylon in the form of 2 curved plates, 1
on either side of the cell; chloroplasts several ovoid discs; cells
11-13, in diameter, 30-34» long.
Conrad in his’monograph (1934) does not record any species
which combine the characteristics of our specimens. The size of the
cell and the long, tapering caudus are distinctive.
Among other algae in a fosse. Wis.
- [ 405 |
Lepocinclis fusiformis (Carter ) Lemmermann 1901, p. 89
Pl. 89, Figs. 1-4
Cells broadly fusiform or pyriform, slightly produced posteriorly
to form a blunt basal point; membrane spirally striated; paramylon
bodies 2 to several circular plates; flagellum about as long as the
cell; 15-17 in diameter and up to 36, long.
In a roadside fosse. Wis.
Lepocinclis fusiformis var. major Fritsch & Rich 1930, p. 72
Pl. 89, Figs. 7, 15
Cells elongate-ovoid to subfusiform, broadest below the midregion,
produced posteriorly into a very short obtuse tail-piece; usually
with a bipapillate protrusion at the anterior end; periplast sometimes
with extremely fine spiral striations (almost straight in our speci-
mens); paramylon bodies 2 very large oval rings, sometimes over-
lapping one another; chloroplasts numerous irregularly shaped discs;
cells 25-29-(39) in diameter, 39-58, long.
This variety is originally described as having, at times, many small
paramylon bodies, but our specimens showed only the large rings.
The periplast is very faintly striated, a character seen only under
favorable conditions. This species should be compared with L.
Steinii Lemm. and L. costata Playf. These species are somewhat
similar in shape but differ in size and details of the periplast fea-
tures, as well as in the form of the paramylon bodies.
Tow from a small pond. Wis.
Lepocinclis glabra Drezepolski 1925, p. 269
Pl. 89, Fig. 14
Cells broadly ellipsoid or ovoid, broadly rounded posteriorly but
with a short, blunt caudus; very slightly narrowed anteriorly, with
a bipapillate protrusion through which the flagellum arises; flagellum
about as long as the body; periplast smooth (?); paramylon in the
form of 2 very large, curved plates, one on either side and in certain
positions appearing as 4 plates; cells 19-21, in diameter, 25-31, long.
In a roadside fosse. Wis.
Lepocinclis glabra fa. minor Prescott 1944, p. 370
Pl. 89, Fig. 10
Cells broadly ovoid, with a short papilla-like caudus, broadly
rounded anteriorly and ending in a bipapillate protrusion through
which the flagellum emerges; flagellum about as long as the body;
periplast smooth; paramylon in the form of 2 semicircular bands,
[ 406 ]
curving transversely at the periphery of the cell, one on either side;
chloroplasts numerous, oval discs; cells 14-16 in diameter, 20-22y
long, smaller than the typical form.
In a tow sample from a cedar swamp. Wis.
Lepocinclis ovum (Ehrenb.) Lemmermann 1901, p. 88
Pl. 89, Figs. 5, 6
Cells broadly ovate, with a short, blunt caudus, rounded both
anteriorly and posteriorly; periplast spirally striated to the right;
flagellum about as long as the body; paramylon in the form of 2
rings, 1 on either side of the cell; cells 22-25y in diameter, 28-30,
long.
oem in ditches, swamps and small ponds; also found in the
shallow water of bays and lagoons among dense growths of algae;
rarely euplanktonic. Mich., Wis.
Lepocinclis Playfairiana Deflandre 1932, p. 227
Pl. 89, Fig. 16
Cells broadly oval with a short caudus, slightly narrowed and
sharply rounded anteriorly, the gullet and flagellum attachment
lateral to the apex, where there is a slight invagination on the right
side; periplast smooth; paramylon bodies 2 large circular or oval
rings; cells 28-30, in diameter, 46-48, long.
In tows from swamps and ponds. Wis.
Lepocinclis sphagnophila Lemmermann 1904, p. 124
Pl. 89, Figs. 11-18
Cells fusiform or ovoid, narrowed posteriorly into a short caudus,
tapering anteriorly and forming a bluntly rounded apex which is
bipapillate (in our specimens); paramylon bodies 4 plates, 2 on
either side; chloroplasts relatively few ovoid discs; flagellum length
(?); cells 8-10» in diameter, 22-25, long.
Our specimens are assigned here because of their general agree-
ment with Lemmermann’s description. Conrad (1934) reports this
as a doubtful or little known species.
Not infrequent in soft and acid water habitats. Wis.
TRACHELOMONAS Ehrenberg 1835, p. 315
In this genus euglenoid cells are enclosed in a firm gelatinous
shell which has an opening for the flagellum. The shell or test has
an almost endless variety of shapes and forms of decoration, and
since these features are specific the taxonomy of the genus is based
[ 407 |
upon characteristics of the test rather than on those of the proto-
plast. The test is brown, often opaque, or tan to nearly colorless,
according to the amount of iron compounds deposited in it. The
test may be smooth or decorated with spines, warts, reticulations,
punctations, or combinations of these. The protoplast inside is highly
metabolic and has the general features of the euglenoids. There is
1 flagellum, a red pigment-spot, and numerous ovoid, disc-like
chloroplasts which may have pyrenoids. Reproduction is by cell
division, which takes place within the test, one of the new cells
escaping through the aperture and secreting its own shell.
Although a few species may appear in the euplankton, most
species of Trachelomonas occur in shallow water of swamps, ditches,
and lagoons as tychoplankters, especially where there is a high con-
centration of organic matter and where temperatures are high. The
organisms may be so abundant as to color the water brown, although
they never form a conspicuous surface film as does Euglena.
Key to the Species
1. Test with the flagellum opening in a neck, or
Surrounded mibYyieaeCOllan earache urn ee eee See ee 2
1. Test without a neck or collar around the flagellum aperture................ 22
2; Flagellum) opening “in) a> distinct® necks. sts eee ee eee 3
2. Flagellum opening in a collar or thickened ring (*)..0.00.00.00.0ccccc... 12
3. Test globose, with 4 or 5 long, sharp spines.....................00000000-+. T. aculeata
3. West with ‘shorter, more numerous (Spimes .2..0.20). sess. cetosecescveeeseceee ec. 4
4. Test extended into a long, spine-tipped caudus ....................... T. speciosa
4. Test without a caudus, or if present not spine-tipped.......................... 5
5. lest isexangullan-ellipsoid teen e300) se Pe ee eee T. hexangulata
Dilest™ some Other” SHAPE. ee ee ee Re I a eae 6
6. Test broadly ovoid, wrinkled and rugose;
MECKIBiWisted WORM CURVEC tne YN cen nts cue die cnet ode a eae T. scabra
GP lest shaped otherwise; mot. FugOSe!:.6..- 02 eoeeae keene ee ee ee 7
7. Test rectangular-fusiform, margins retuse, extended into a
Candis ett A nok eee le be cst. rune Aceh eee aoe rhs pee T T. Girardiana
7. Test some other shape, not extended into a caudus.........0....0..0.0:000000 8
lest a-elongate-ellipsoids. east edi tee koe too ee ee ee 9
Sn Lest; oblong-cylindricor oblong: ee ee ee 10
9. Test with numerous, minute spines, punctate;
Warn Of “COMAT PSIMOOEN ; 4-0-5. 00 cesco nm tosesospes ssa ae oases Poe ae T. bulla
9. Test with scattered, stout spines; collar
foothed sat thes marginus eee. ee eee et ay eee reas T. sydneyensis
105 Test oval’ to,oblong. collar curveds.cn.2. cl pc euen idee ee T. similis
10. Test some other shape; collar not curved ....................... Peet Rh Ls ll
(*) The thickened ring is a variable feature in some species. For question-
able forms, follow through both No. 2 choices.
[ 408 ]
Tests anpularnly* oblong, bottle-shaped 2205. 2.2.-::...0<2-..-----o- 2! T. euchlora
. Test oblong-cylindric, lateral margins parallel.........0...00000........... T. dubia
. Test beset with long or short spines ...... val hic Gen 0 Ae pe ea A ie 13
. Test without spines; either smooth or with granules or warts................ 16
Wham: Of-collar beset with stout Spimes!s.5 4. Gesclcw.csteelosesdisocrs.:. T. armata
EIEIO S ADELEUITE pSTMOOL ce sai a eet. ee er en aa one 14
Milestrovalyewith long-. stout; -spines= 0 este. ssetec.ves cakes T. horrida
. Test broadly oval to subspherical, with short spines or sharp warts... 15
15. Test subspherical, beset with sharp warts or very short
SIUIINES Fee ee ee SE cs, a eee Ma Rr a T. hispida
15op@est.oval. beset; with ‘stout Spines......221..0. 406-5 se00-p0-one- eee T. charkowiensis
1G abestmsimsaObitt ese) 2s bea ie as OS een ny ae tee acd eee ben U7
16. Test granular, rugose, OT AS PUNY he sf oe hae ne me We) Bn ioreas 20
17. Test with mammillate collar; spherical Sie ee thc aly VER T. mammillosa
17. Test without a mammillate collar; cylindric or ovalis <2 i. 18
1S eaestarcylinvelraeal Mer tort. ee ide oo. «anette Fae Rese Serres sauces onthe T. cylindrica
Stes OvAltOnuspuencCal, 22. ees totes... casgeki ut eer As ae cone eee 19
19. Test spherical with an inward projecting flagellar tube........... T. varians
19. Test broadly ellipsoid or oval, with short curved collav.......... T. Playfairii
20. Test oval, (19)—23—25u in diameter, 31—33u
lonmemnnitormnly seranilatey ee ey tl ho, cee a) hore tae cee aa ae T. crebea
20. Test ellipsoid to ovoid, smaller, (5)—19u in diameter.................0..0....... 21
21. Test oval, 5—11—17u in diameter, W767 gl Cosa aes On ae a T. pulchella
21. Test ellipsoid, 19a an ‘diameter. 20py, long 7 cc.ccrsapteetesneseee? T. granulosa
22. Test triangular, flagellum aperture occupying the entire
ESF ec hace meant Rh ners ORME AREER UR og e PAN PATE OR RORaay ai pimpin Ra amr T. triangularis
22. Test some other SHADE: APeCKEMTE: MATTOWED \ 20.0 c5..5.65- cece esc sateen cosas sete 23
D3e Vhest A cpuentcal mon SUDSPleTICA bls foots sous sete et aastatenees eee eeeste 24
93° Test elongate, ovoid or: cylindrical’... 4 ...04:.3.c%-d.. = G. palustre
Glenodinium armatum Levander 1900, p. 103
Pl. 90, Fig. 7
Cells spherical in outline, unsymmetrically divided by a broad,
transverse furrow, the epicone longer, almost hemispherical but
sharply rounded at the apex; the hypocone short, broadly rounded
at the pole and with a short conical projection on the left side
(right side as seen from the ventral surface); plates scarcely visible
in the thin but firm theca; chromatophores radially arranged ovoid
plates; pigment-spot present in the longitudinal sulcus which is
hardly visible but which extends from the transverse furrow almost
to the posterior pole; cells 19-28 in diameter, 16-29.7, long.
Tychoplankter. Wis.
Glenodinium Borgei (Lemm.) Schiller 1935-1937, p. 112
[Peridinium Borgei Lemmermann]
Pl. 90, Figs. 8, 9
Cells broadly ovoid to subglobose, the epicone high and shortly
apiculate; not dorsiventrally compressed but round in polar view;
epitheca with 1 apical, 2 intercalary, and 6 precingular plates; the
[ 428 ]
apical plate on the dorsal side not extending to the apex; hypotheca
with 5 postcingular and 2 antapical plates; cells 36-40, in diameter,
4046p. long.
Tychoplankter. Wis.
Glenodinium Gymnodinium Penard 1891, p. 54
Pl. 90, Figs. 10, 11
Cells broadly oval as seen in the ventral view, dorsiventrally flat-
tened as seen vertically; transverse furrow broad, turning spirally
to the left; longitudinal furrow extending from the epicone to the
apex of the hypocone, the left margin of the longitudinal furrow
with a flange which ends in a tooth at the posterior pole; epitheca
with 1-(2?) apical, 4 intercalary, and 7 precingular plates; hypo-
theca with 5 postcingular and 2 antapical plates; chromatophores
brownish-green; cells 35, in diameter, 40, long.
Tychoplankter. Wis.
Glenodinium Kulczynskii (Wolosz. ) Schiller 1935-1937, p. 96
PI. 90, Figs. 12-14
Cells broadly ovoid or nearly round as seen in ventral view,
flattened in polar view, the dorsal margin broadly convex; epitheca
with 1 apical, 3 intercalary, and 6 precingular plates; hypotheca with
6 postcingular and 2 antapical plates; longitudinal furrow extend-
ing to the apex of the hypocone; cell 30-31.5y in diameter, 35, long.
Tychoplankter. Wis.
Glenodinium palustre (Lemm.) Schiller 1935-1937, p. 99
[Gonyaulax palustris Lemmermann]
Pl. 90, Figs. 15, 16
Cells globose with the transverse furrow slightly but clearly
spiral; longitudinal furrow extending from the epicone through the
hypocone; epitheca with 1 apical plate, 3 intercalary and 6 precin-
gular plates; hypotheca with 5 postcingular and 1 antapical plate;
cells 25-30, in diameter, 27-34, long.
Plankter; in several, mostly soft water, lakes and acid bogs. Wis.
Glenodinium Penardiforme (Linde.) Schiller 1935-1937, p. 113
Pl. 90, Fig. 21
Cells small, ovoid, the epicone sharply rounded and slightly api-
culate, dorsiventrally flattened; the hypocone broadly rounded and
emarginate at the pole; transverse furrow broad; longitudinal fur-
row scarcely extending into the epicone, broadening into the
[ 429 ]
hypocone and reaching the posterior pole; cells 20-25, in diameter,
30-35p long.
The plates are very inconspicuous in the specimens seen and their
assignment is questionably made on the basis of present information.
G. Penardiforme is described as having 4 intercalary and 6 precin-
gular plates in the epitheca, 5 postcingular and 2 antapical plates
in the hypotheca; the cell with or without chromatophores.
Not uncommon; in several soft water lakes, ponds, and swamps.
Wis.
Glenodinium pulvisculus (Ehrenb.) Stein 1883, Ill, part 2
Pl. 90, Figs. 17, 18
Cells ovate to subglobose, the epicone and hypocone both broadly |
rounded at the poles; transverse furrow winding to the left; longi-
tudinal furrow extending into the epicone and posteriorly almost to
the pole of the hypocone; chromatophores numerous, golden-brown
bodies; cells 13-19-(29) in diameter, 23-35, long.
The plates of the theca of this species are as yet incompletely
known, and the assignment to the genus Glenodinium is question-
able. As suggested by Eddy (1930) it may belong to Gymnodinium.
Tychoplankter. Mich., Wis.
Glenodinium quadridens (Stein) Schiller 1935-1937, p. 117
Pl. 90, Figs. 19, 20
Cells ovate, the epicone apiculate, the hypocone broadly rounded
and furnished with 3-5 short, sharp spines, laterally and posteriorly
placed; transverse furrow not spiral, usually median and equally
dividing the cell; longitudinal furrow extending into the epicone,
widening posteriorly and reaching the apex of the hypocone;
epitheca with 1 apical, 5 intercalary, and 7 precingular plates;
hypotheca with 5 postcingular and 2 antapical plates with a stout
spine on each; cells 20-35, in diameter, 2480p long.
Tychoplankter. Wis.
HEMIDINIUM Stein 1883,p. 90
Cells unsymmetrically ellipsoid, much flattened dorsiventrally,
both poles broadly rounded, the anterior less so and somewhat
cone-shaped; transverse furrow incomplete, spirally descending to
the left; membrane covered by a very thin theca in which there
are indistinctly marked areolate plates; epitheca with 6 apical,
6 precingular plates; hypotheca with 5 postcingular, 1 intercalary,
[ 430 ]
and 1 antapical plate; chromatophores golden-brown fusiform bod-
ies, radially arranged.
The plates in this genus can be discerned only under favorable
optical conditions.
Hemidinium nasutum Stein 1883, p. 91
Pl. 90, Figs. 4-6
Cells elliptical or narrowly ovoid; transverse furrow incomplete,
curving down to the right as seen from the ventral side; longitudinal
furrow forming a narrow sulcus which extends from the transverse
furrow to the posterior pole which is broadly rounded; cell 16-20,
in diameter, 24-28, long.
Fairly common in the plankton of several lakes, especially in
marginal waters among dense beds of other algae. Wis.
FAMILY PERIDINIACEAE
This family has cells which are globose, or only slightly flattened,
fusiform, or top-shaped. The transverse furrow is broad and hori-
zontal, definitely dividing the cell into epicone and hypocone.
Although usually broadly rounded anteriorly, the epicone may be
narrowed and pointed at the apex. The hypocone likewise is usually
broadly convex, but in a few forms it may be somewhat produced
to form one or more lobes or conical projections. Reproduction is
by cell division. Resting cysts of specific shape are used during
periods of adverse environmental conditions.
PERIDINIUM Ehrenberg 1832a, p. 38
[Peridinium Ehrenb., Stein 1883]
Cells globose, ovoid, or fusiform (in fresh-water species ), usually
somewhat dorsiventrally flattened, either broadly rounded at the
poles or produced to form apiculations or short horns; transverse
furrow infra-median and slightly spiral, the epicone sometimes with
a true apex and a pore at the anterior pole, or with a false apex
that is produced into a horn without a pore and is longer than the
hypocone; longitudinal furrow usually broad in the hypocone and
extending to the posterior pole, or not, and into the epicone slightly;
flagella attached in the ventral sulcus, one winding about the cell
in the transverse furrow, the other trailing; arrangement and num-
ber of plates in the epitheca variable, usually 4 apical, 3 intercalary
and 6-7 precingular plates, one of the apical plates extending from
the top of the longitudinal sulcus to the apical pole (the rhomboid
or ventral plate); hypotheca with 5 postcingulars and 2 antapical
[ 431 ]
plates; all plates conspicuously marked with reticular thickenings
and sometimes other decorations, such as small spines, and with
narrow or wide sutures between the plates which are usually
striated, as is also the transverse furrow; in some species with a
conspicuous flange or wing-like rim about the cell through which
small ribs or concretions radiate to the margin from the surface of
the plates.
Key to the Species
1. Cells broadly fusiform, extended posteriorly into 1 or more processes. 2
Ti iCells) broadly rounded) posteriorly, 225 228 5S eae ee ee eee 8
(See P. cinctum var. tuberosum, however. )
2. One posterior horn-like extension_.______-_-_.-_-----.-------------- P. wisconsinense
2. Two: posterior horn-like extensions=+ == Se P. limbatum
CE Gell onl Uutancbihoo (elas @ Geet eee Eee ne es ae ee ee 6
SenGelisy lary e ten xe a hk a i ee ol PA ee 4
4.1G@ellsmeanly, cixeularsimpout line sas ee ee eee 5
4 Gellsidistinctlyslonger than broad === ss a eee P. Willei
5. Cells 35-55y in diameter; longitudinal furrow extending
for some distance into the epicone______-_______ P. cinctum
5. Cells 55-80u in diameter; longitudinal furrow
scarcelya extending into ‘the epiconé: 2-2) P. gatunense
6. Cells with 3 small teeth at the posterior pole___________ P. inconspicuum
6. Cells with broadly rounded smooth antapical poles _________ P. pusillum
Peridinium cinctum (Muell.) Ehrenberg 1838, p. 253
P]. 91, Fig. 1-4
Cells globose, subglobose, or broadly ovoid in ventral view, very
slightly flattened dorsiventrally as seen in polar view; transverse
furrow broad, spiral, dividing the cell almost equally on the left
side (as seen ventrally) but spiralling to a supramedian position
on the right; plates thick and coarsely reticulate; epicone high and
broadly rounded, epitheca with 4 apicals (including the rhomboid
plate), 3 intercalary, and 7 precingular plates; hypocone broadly
rounded posteriorly, hypotheca with 5 postcingular and 2 antapical
plates; cells 35-55, in diameter, 40-60, long.
Fairly common in both euplankton and tychoplankton. Mich., Wis.
Peridinium cinctum var. Lemmermannii
G. S. West 1909, p. 190
Cells 62-70 in diameter, 56-70» long, 52-53, thick; a variety in
which the right antapical plate is distinctly larger than the left.
Euplanktonic and tychoplanktonic. Mich., Wis.
[ 432 ]
Peridinium cinctum var. tuberosum (Meunier )
Lindemann 1928, p. 260
Pl. 91, Figs. 7-12
A variety larger than the typical, 63» in diameter, 66.6, long,
and more nearly globose, scarcely if at all dorsiventrally flattened;
in ventral view the epicone broadly rounded in general outline,
with angulations at the margin where it is interrupted by the sutures
of the plates, sometimes apiculate at the pole; plates variable,
usually with 4 apical, 3 intercalary, and 7 precingular plates; the
2 hypothecal plates produced posteriorly to form 3 stout, blunt
horns (the variety is described as having 3 antapical plates, but
Wisconsin specimens seem to have but 2 in every case); the cell
showing a flange that extends from the transverse furrow around
to the poles; plates coarsely reticulate.
Tychoplankter; in ponds and swamps. Wis.
Peridinium gatunense Nygaard in Ostenfeld
& Nygaard 1925, p. 10 (reprint)
Pl. 90, Figs. 25, 26
Cells globose to elliptic, with angulations at the marginal sutures;
(as seen ventrally), the poles broadly rounded; transverse furrow
spiral with a wide border, unequally dividing the cell into a greater
epicone and a shorter hypocone; the longitudinal furrow extending
from high in the epicone to near the posterior pole; plates with
wide, striated sutures between them, coarsely reticulate; epitheca
with 13 plates; hypotheca with 2 large antapicals and 5 postcingular
plates; cells 55-80, in diameter, 45-80, long.
Tychoplanktonic and euplanktonic. Wis.
Peridinium inconspicuum Lemmermann 1900, p. 350
Pl. 90, Figs. 22-24
Cells small, ovoid, with the apical region slightly produced and
pointed, the posterior pole broadly rounded with 2 or 3 short, sharp,
horn-like projections; in polar view slightly flattened dorsiventrally;
transverse furrow broad, without a marginal ridge, or with a very
narrow one (although the furrow is very deep), not spiral, dividing
the cell into a tall epicone and a short hypocone; longitudinal furrow
very broad in the hypocone, extending from the posterior pole into
the epicone a short distance; epitheca with 13 plates and a true apex;
hypotheca with 2 large antapical and 6 postcingular plates; cells
18.5-20, in diameter, 22-25, long.
The plants are small and the plate characteristics are seen with
difficulty unless empty cells are found. This species often appears in
[ 433 ]
great numbers, although it is less widely distributed than some other
species of Peridinium in our collections. Several of the described
varieties have been noted in our collections, but according to
Schiller (1935) these should be referred to the typical form and
the varietal names not retained.
Plankter; found in several, especially soft water, lakes and in
desmid habitats. Wis.
Peridinium limbatum (Stokes) Lemmermann 1900c, p. (120)
Pl. 91, Figs. 16-18
Cells ovate, the epicone narrowed and produced to form a promi-
nent apiculation which is bifurcate and often turned to the left
when viewed from the ventral side; hypocone broad, with 2 stout
posterior horns; transverse furrow broad, slightly spiral, unsymmetri-
cally dividing the cell into a high epicone and a short hypocone;
longitudinal furrow very broad in the hypocone, extending from
the posterior pole to well within the epicone; rhomboid plate extend-
ing from the top of the longitudinal furrow to the apical pole, which
has a true apex and pore; epitheca with 10 plates; hypotheca with
5 (?) postcingulars and 2 antapical plates (these two produced to
form the posterior horns); sutures and transverse furrow striated;
plates reticulate; cells 60-65, in diameter, 80-85.5 long.
Rare; in the plankton of soft water lakes and in Sphagnum bogs.
Wis.
Peridinium pusillum (Penard) Lemmermann 1901d, p. 65
Pl. 107, Figs. 7-9
Cells ovoid, somewhat flattened dorsiventrally, the epicone
slightly longer than the hypocone so that the transverse furrow is
inframedian, and not spiral; epitheca slightly produced at the apex
and emarginate, with 7 precingular and 6 apical plates; hypotheca
with 5 postcingular and 2 antapical plates; chromatophores golden-
brown; 13-20y in diameter, 18-24, long.
Mich.
Peridinium Willei Huitfeld-Kaas 1900, p.5
Pl. 91, Figs. 22-25
Cells large, subglobose, very little compressed dorsiventrally,
broadly rounded at both poles, with a wing-like flange which forms
a crest anteriorly and two lobes posteriorly, and with raised edges
along the margins of the sutures of the plates (especially in mature
cells); transverse furrow broad, spiral, dividing the cell unsymme-
trically into a high epicone and a short hypocone, with a wide
border that often extends down along the edge of the longitudinal
[ 434 ]
furrow, producing a wing-like flange; longitudinal furrow broad in
the hypocone, extending into the epicone from the posterior pole;
rhomboidal plate broadly wedge-shaped, widest at the top and
reaching from the margin of the longitudinal furrow to just below
the anterior pole where there is not a true apex; epitheca with 14
plates, 7 precingulars, 3 apicals (median), 2 ventral apicals, 1 dorsal
apical, and a rhomboidal plate; hypotheca with the usual arrange-
ment of 5 postcingular and 2 large antapical plates; cell 49-55 in
diameter, 50—70y long.
Plankter; in a variety of lakes; widely distributed but seldom
occurring in abundance. Wis.
Peridinium wisconsinense Eddy 1930, p. 300
Pl. 91, Figs. 13-15
Cells large, spindle-shaped, slightly flattened dorsiventrally when
seen from the poles; epicone greatly produced to form a prominent
cone and the hypocone likewise produced to form a single, stout
sharply-pointed horn; transverse furrow broad, slightly spiral (in
our specimens, but described as strongly spiral), almost equally
dividing the cell into conical epi- and hypocones; longitudinal fur-
row extending from about half way to the posterior pole to the
transverse furrow but not into the epicone; rhomboidal cell ex-
tending from the top of the longitudinal furrow to the apical pole
which has a true apex; epitheca with 14 plates (including the rhom-
boidal), 1 median apical, 2 ventral apicals, 1 right lateral apical (on
the left as seen from the top), and 2 dorsal apicals; hypotheca with
5 postcingular and 2 antapical plates, one of which (left, as seen
from the posterior pole) forms the posterior horn; plates coarsely
reticulate; cells 48-56u in diameter, 55-64, long; cyst broadly ovoid
with one pole sharply and the other bluntly pointed, the membrane
thick and lamellate at the poles.
Originally described from Lake Oconomowoc, Wisconsin.
Common in a variety of lakes; frequently abundant in favorable
habitats. Mich., Wis.
FAMILY CERATIACEAE
This family (erected for the genus Ceratium) has cells which
are fusiform in general outline. As described below, there is a
prominent apical horn in the epicone and 2-3 posterior horn-like
processes in the hypocone. The longitudinal sulcus is very broad
and short. The cell undergoes division in such a way that one of
the new protoplasts inherits 4 apical, 2 precingular and three post-
cingular plates, while the other portion retains the remaining 2
[ 435 ]
precingular, the 2 antapical and 2 postcingular plates. This means
that the plane of division and separation of plates is oblique. The
daughter protoplasts continue to move about and gradually build
in the necessary complement of plates.
CERATIUM Schrank 1793, p. 34
In this genus there are broadly fusiform cells which have 3 or 4
horns, one anterior and 2 or 3 posterior. The epivalve of the theca
(broad just above the girdle) soon narrows abruptly to form the
apical horn, which is composed of 4 plates. The hypotheca has 5
postcingular and 2 antapical plates, the latter forming the longest
posterior horn. In forms which have 3 posterior horns, one is very
short. There are no broad sutures between the plates as in some of
the related genera. The transverse furrow opens into a broad longi-
tudinal sulcus. The entire theca is uniformly marked with a fine
reticulum, the meshes of which are 5- or 6-sided. There are numer-
ous brown disc-like chromatophores which are often obscured by
the semi-opaqueness of the theca.
Most species of Ceratium are marine but there are a few fresh-
water plankters, usually occurring more abundantly in hard water
than in soft water lakes.
Key to the Species
1. Apical horn long and tapering, as long as or longer than the
cell body and! the posterior homs — 2-2 C. hirundinella
1. Apical horn shorter than the remainder of the cell 2
2. Apical horn sharply curved and tapering
(OV evel OVPUN © 0,0) 00) ¢ Meee en eee C. carolinianum
2. Apical horn straight but directed at an angle from the longitudinal
axis; squarely truncate at the apex C. cornutum
Ceratium carolinianum (Bailey) Jorgensen 1911, p. 14
[C. curvirostre Huitfeldt-Kaas]
PI. 92, Figs. 2,3
Cells broadly fusiform in outline; epivalve broad above the
transverse furrow, narrowed abruptly to form a stout, curved apical
horn, with a shoulder on each side at the base; transverse furrow
relatively narrow; hypotheca broad, with a short diverging horn
on the left (as seen from the ventral surface), and a longer central
horn which is somewhat obliquely directed; cells 65-80, in diam-
eter, about twice as long as broad.
Plankter; in Sphagnum bogs, ponds and ditches. Wis.
[ 436 ]
Ceratium cornutum (Ehrenb.) Claparede
& Lachmann 1858, p. 394
Pl. 92, Figs. 8,9
Cells broadly fusiform in outline, stout, the epitheca broad above
the transverse furrow, the sides rapidly converging and narrowed
to form a short, stout anterior horn which extends obliquely and is
truncate at the apex; transverse furrow relatively broad; hypotheca
broad below the furrow, extended into 2 horns, 1 short lateral horn
and 1 longer and median; cells 75-SO» in diameter, about as long
as wide, or slightly longer.
Rare; in the plankton of soft water lakes. Mich., Wis.
Ceratium hirundinella (O. F. Muell.) Dujardin 1841, p. 377
Pl. 92, Figs. 4,5
Cells broadly or narrowly fusiform in outline, depending upon
the degree of divergence of the horns; very much flattened dorsi-
ventrally; epitheca with sharply converging margins from just above
the transverse furrow, then narrowed more gradually to form a long
horn; transverse furrow relatively narrow; body of the hypotheca
broad and short below the transverse furrow, divided into a varying
number of posterior horns, usually 3, sometimes only 1, the central
or median horn the longest and formed by the antapical plates;
plates coarsely reticulate; cells varying in size depending upon
environmental conditions, 100-400, long.
This species is very common, especially in hard water lakes, where
occasionally it may become so abundant as to color the lake a deep
brown. Such blooms develop and disappear suddenly.
This species shows a great variation in the form of the cell, num-
ber of horns, etc., and it is often the subject of ecological and
limnological studies. It shows a remarkable periodicity and may
exhibit a vertical distribution which is accompanied by some inter-
esting relationships between the length of the horns and buoyancy;
form of the cell and temperature, etc.
The tremendous amount of nitrogen, phosphorus, and products
of photosynthesis which accumulate in these organisms when they
develop a bloom must certainly produce interesting limnological
effects in a lake. In spite of the wealth of literature on this genus,
very little seems to have been published on the role that these
species play in lake biology.
Mich., Wis.
ORDER DINOCOCCALES
These are forms which are not motile in the vegetative state and
which are incapable of cell division. They exist as either free-
[ 437 ]
floating or sedentary attached unicells of various forms, crescent-
shaped, quadrangular, or pyramidal, with the angles extended into
horns or spines. Usually the wall is thick and shows lamellations
where it is thickened at the poles or angles. Many have an expression
similar to the encysted phase of the motile Peridiniales. In their
reproductive methods the Dinococcales employ autospores or zoo-
spores. There are 2-8 of these formed in a cell. In some forms the
zoospores show a transverse furrow and other Gymnodinium fea-
tures. The spores, upon escape, enlarge and assume the expression
of the nonmotile parent cell. One family is recognized.
FAMILY DINOCOCCACEAE
Characteristics as described for the order.
Key to the Genera
i} Cells: free-toating.. lunate or arcuate,— = sss ae Cystodinium
1. Cells attached, transversely ellipsoid or inversely
buaugularsneiront view ee eee 2)
2. Cells triangular or tetrahedral (especially when
SEER TOMIADOVE)* aes ae ne To ea ee Tetradinium
2 Cells tellipsoid 2-5! a .2) 2 esa Raciborskia
CYSTODINIUM Klebs 1912, pp. 384, 442
Cells free-floating, lunate or arcuate, the poles extended to form
sharp, usually recurved spines; longitudinal and transverse furrows
lacking, although the position of the furrows is represented in the
swarmers formed by the division of the protoplast within the parent
cell; chromatophores several to many, brown, more or less pointed
or fusiform discs; nucleus conspicuous and centrally located, pig-
ment-spot usually lacking.
Key to the Species
1. Cells broadly crescent-shaped, the outer margin broadly convex,
the mmer slightly tumidionsteighie = C. iners
1. Cells narrowly crescent-shaped, the outer margin convex, the
inner margin concave (sometimes straight in the midregion) 2
2. Each pole of the cell ending in a curved spine which is twisted
away from the longitudinal axis of the
cell *cellsiGo U0 long seen Sh ee ee C. Steinii
2. Each pole of the cells ending in a spine, 1 straight, the other
twisted away from the longitudinal axis of
the cell cells| 40-60 .vlong = C. cornifax
Cystodinium cornifax (Schill.) Klebs 1912, pp. 384, 442
Pl. 91, Figs. 5, 6
Cells lunate, the dorsal margin strongly convex, the inner margin
concave (slightly straight in the midregion); poles extended into
[ 438 ]
colorless, somewhat twisted horns, one of which is recurved and is
directed at an angle from the longitudinal axis; protoplast forming
2 (or only 1) Gymnodinium-like swarmers which have a wide trans-
verse furrow, dividing the zoospore into a broadly rounded anterior
portion and a broadly conical or sharply pointed posterior, with
pigment-spot showing in the longitudinal furrow; cells 28-36y in
diameter, 40-60, long (sometimes longer); swarmers about 20
in diameter, 25, long.
In the tychoplankton of several lakes and swamps; frequently
found in desmid habitats. Wis.
Cystodinium iners Geitler 1928a, p.5
Pl. 91, Figs. 19-21
Cells crescent-shaped, strongly convex on the dorsal margin,
tumid (or straight) on the ventral or inner margin, ending in sharp
points at the poles, with the wall much thickened at the base of the
horns, which are in the same plane with the longitudinal axis of the
cell; protoplast usually showing a transverse furrow, appearing as
a Gymnodinium-like cell dividing to form two swarmers; chromato-
phores numerous ovoid plates; cells 25-28-(30) in diameter, 60-80p
long, including the apical spines.
Mich., Wis.
Cystodinium Steinii Klebs 1912, pp. 382, 442
PI. 93, Figs. 1, 2
Cells crescent-shaped, the dorsal margin more strongly convex
than the ventral; apices terminating in curved and slightly twisted
points, each projecting at a different angle from the longitudinal
axis of the cell; upon dividing producing 2 Gymnodinium-like
swarmers with a broad transverse furrow and with both poles
broadly rounded; pigment-spot in the longitudinal furrow; cells
25-35 in diameter, 65-100-(110), long; swarmers 30-35, wide,
40-50, long.
Rare; in the tychoplankton of lakes and acid swamps. Mich., Wis.
RACIBORSKIA Woloszyhska 1919, p. 199
Cells attached, inversely triangular-ellipsoid as seen from the
front, ellipsoid when seen in vertical view, the poles tipped with a
single stout spine; attached by a short stalk to the substrate; in side
view the upper margin straight, the 2 lateral margins straight or
slightly convex, converging to the thick stalk; reproduction (?).
[ 489 ]
Raciborskia bicornis Woloszynska 1919, p. 199
PI. 93, Figs. 4-7
Characteristics as described for the genus; cells 25-35y long,
including the spines, 9-12” in diameter.
Rare; attached to the aquatic moss Drepanocladus in 35 feet of
water; on large filamentous algae. Wis.
TETRADINIUM Klebs 1912, p. 408
Cells triangular or tetrahedral, attached by a short stalk to a
substrate, the angles tipped with 1 or 2 short, stout spines; chromato-
phores many small ovate discs; nucleus central; reproduction by the
formation of 2 swarmers in each cell.
Key to the Species
Angles’ of the’ cells tipped’ with 2 spines 2 T. javanicum
Aneles of the/cellsitipped with spine 2 2 T. simplex
Tetradinium javanicum Klebs 1912, p. 408
PI. 93, Fig. 3
Cells inversely pyramidate when seen from the front, the dorsal
margin straight or slightly convex, the lateral margins convex, con-
verging to a short, stout stalk which attaches the cell to the substrate;
angles of the cell furnished with 2 short curved spines: cells 35-50p
in diameter.
Attached to filamentous algae. Mich., Wis.
Tetradinium simplex Prescott in Prescott, Silva, & Wade 1949, p. 89
Pl: 107, Fig. 2
Cells inversely triangular, sessile, with scarcely any stipe, on fila-
mentous algae, the dorsal margin broadly convex in front view, the
angles tipped with a single, downward projecting spine; triangular
in top view, the angles bearing a short spine; cells 12-25 in diam-
eter, 12-20, high.
On filamentous algae in shallow water of acid ponds. Mich.
CLASS CRYPTOPHYCEAE
In this group the organisms are mostly motile by means of 2 apical
or lateral flagella (Cryptomonadales), but coccoid forms (Cryto-
coccales) have been placed here also. The cells are dorsiventrally
flattened, ovoid, slipper-shaped, or reniform, and possess a longitudi-
nal furrow. In some, a gullet extends inwardly from the furrow in
the anterior end of the cell. The pigments are dark golden-brown,
[ 440 ]
localized in (usually) 2 parietal and (in our specimens ) laminate
chromatophores which may possess pyrenoids. Both starch ( staining
blue with iodine) and oil are produced as food reserves. The cells
are uninucleate and possess a contractile vacuole. In some forms
trichocysts border the furrow. There are 3 subgroups, one of which
is without pigmentation.
Key to the Genera
Glee Pasen bi 3.5 ooo. sinin odin uct Se ee Bint Pn Chroomonas
( Cryptochrysideae )
Culllet Soresent ..22..6..5. 00. ee ee eee Ea crt ds xaces.. CRY PEOMONGS
( Cryptomonadeae )
CHROOMONAS Hansgirg 1885, p. 230
Cells swimming by 2 apical flagella, dorsiventrally flattened,
elongate-ellipsoid or pyriform, broader toward the anterior end,
which is unsymmetrically bilobed, narrowed but broadly rounded
at the posterior end; longitudinal furrow narrow and shallow, with-
out a gullet, extending farther on the ventral surface than on the
dorsal; chromatophores 2 lateral parietal bands.
Chroomonas Nordstedtii Hansgirg 1885, p: 230
Pl. 95, Fig. 45
Cells slipper-shaped, broader toward the anterior end, which is
unsymmetrically bilobed; narrowed posteriorly but broadly rounded
at the pole; chromatophores 2 broad, parietal bands; cells 9-16,
long, 4-8, in diameter.
Common in shallow water of lakes and among algae masses and
decaying vegetation; in shallow pools and bogs. Wis.
CRYPTOMONAS Ehrenberg 1838, p. 40
Cells slipper-shaped, dorsiventrally flattened, convex on the
dorsal surface, flat or concave ventrally, with a broad and con-
spicuous longitudinal furrow from which a gullet extends inwardly
from the anterior end; flagella 2, attached on the ventral surface at
the anterior end; chromatophores | or 2, lateral and parietal; starch
grains often present in the form of short rods; trichocysts sometimes
discernible along the margins of the furrow; contractile vacuoles 1-3.
Key to the Species
Gullet extending scarcely to the middle of
thevcell; cells: 15-3 2inlongeemern ee ur ee OY C. erosa
Gullet longer, extending nearly *4 the length of
thescell-cellsilarsersupitorcosm louesiens 2a Se C. ovata
[ 441 ]
~ Cryptomonas erosa Ehrenberg 1838, p. 41
Pl. 95, Fig. 39
Cells broadly ovate or ellipsoid, with the left hand margin (as
seen from the ventral side) arcuate and more convex than the right;
apex almost evenly bilobed, the apical depression deep, the. gullet
broad, extending about 1% or less the length of the cell; chromato-
phores 2 parietal elongate plates, brown (in our specimens), blue-
green or reddish; cells 8-16, in diameter, 15-32, long.
In stagnant waters; swamps; tychoplanktonic in small lakes. Mich.,
Wis.
Cryptomonas ovata Ehrenberg 1838, p. 41
Pl. 95, Fig. 40
Cells broadly ellipsoid or ovate, the left hand margin (as seen from
the ventral side) symmetrically convex, the right nearly straight;
apex unsymmetrically bilobed, the apical depression broad and
shallow, gullet extending about 34 the length of the cell; chromato-
phores 2 elongate parietal plates, brown; cells 5-18 in diameter,
20-80p long.
Euplankter; in lakes and ponds. Mich., Wis.
[ 442 |
DIVISION CYANOPHYTA
In this division the cells are without chromoplastids, the pigments
being diffused generally throughout the peripheral portion of the
protoplast. In some forms the pigments occur as granules crowded
and somewhat localized just within the cell membrane. Besides the
usual complement of pigments found in the green algae (although
chlorophyll-b is lacking in the Cyanophyta), phycocyanin (water-
soluble) and myxophycean phycoerythrin may be present. Different
concentration and combinations of these pigments are responsible
for the multitudinous colors exhibited by the blue-green algae.
Photosynthetic products are glycogen and glycoproteins rather
than starch. Frequently proteinaceous granules (cyanophycin) are
present. There is no definite nucleus, although the presence of
chromatin bodies has been proved in the central region of the cell.
Usually the cells or colonies of individuals are invested by muci-
laginous substances, which may be either soft and watery or firm
enough to form a definite sheath. The cell membrane is thin and is
composed of two layers, the outer one gelatinous and contributing
to the investing mucilage. Many forms contain pseudovacuoles
which are dark and refractive and sometimes cause the cells to
appear black, reddish, or purple. According to some investigators,
these are gas vacuoles; others identify them as pockets of mucilage.
Reproduction occurs principally by fission and by fragmentation,
but in some of the filamentous members, akinetes, sometimes referred
to as gonidia, function as reproductive cells. Sexual reproduction is
unknown in the Cyanophyta. In a few forms, endospores may be
employed. These are especially characteristic of the Chamaesipho-
nales where gonidia-like bodies are formed from the protoplast by
either simultaneous or successive constrictions or divisions.
Colonial organization is very simple, and the range of architecture
is limited, the branched trichome being the climax of structural
complexity.
As interpreted here, the Cyanophyta include 2 classes, the blue-
green algae or Myxophyceae, and the Chlorobacteriaceae, a group
of pigmented, bacteria-like organisms.
CLASS MYXOPHYCEAE
The Chamaesiphonales and Chroococcales constitute the tribe
Coccogoneae, and the Hormogonales the tribe Hormogoneae of
some authors.
[ 443 ]
Doe
Key to the Orders
. Cells club-shaped unicells (in our specimens) showing basal-
distal differentiation; solitary, or forming rather definite layers
on rocks and shells, or epiphytic; reproduction
by jnon-motiles endospores=. 2-2 sateis ce ele en CHAMAESIPHONALES
. Cells other shapes; not reproducing by endospores_._-_-_= 2
. Cells coccoid; solitary or united in colonies of definite or
indefinite shape; reproduction by fission CHROOCOCCALES
. Plants filamentous; reproduction by fission, by hormogonial
fragmentation; or bysdonidiae = tit ee ee HORMOGONALES
ORDER CHROOCOCCALES
This group includes plants which are unicellular or which form
simple colonies of cells. The colonies may be definite or indefinite
in
shape, but there is no differentiation of cells, or interdependence.
A copious gelatinous investment is present in most forms. See Daily
(1942) and Drouet and Daily (1939) for critical studies of this group.
FAMILY CHROOCOCCACEAE
Unicellular or colonial, free-floating or attached to submerged or
aerial substrates. There are no pseudofilamentous arrangements or
expanses produced as in the Entophysalidaceae, another family in
this order, which is not represented in our region.
Key to the Genera
. Plants unicellular or forming small aggregates
of 2-8 \(rarelyy pr to o2)) Cells 2) ees ee ee ee 2
. Plants composed of many cells embedded in copious mucilage,
with'or without apparent: cell) sheaths: ' =. aS eee eee 8
. Cells spherical, forming small clusters
of 2-4 16=32"individuals® 22 Ses Ves ee Chroococcus (in part)
» Cellsslonger than stheir. diameter sie. set ies) altar ee ee et 8
. Cells occurring as blue-green chromoplast-like
loovebies) sin Collodiass lnon? Gallb 4
. Cells not occurring as chromoplast-like bodies
InCOlorless NOStiGe lls meee eke a eer gee ee es Rees ee 5
. Host cell adherent, bearing long bristle-like setae; usually 2-4
host cells inclosed in a common mucilage Gloeochaete
. Host cell free-floating, not bearing setae,
not. inelosed in colonial mucilage-1:— = sss Glaucocystis
. Cells with a gelatinous sheath; several individuals
inclosed by a common mucilage —.._.--.-_--------------- Chroococcus (in part)
. Cells solitary or clustered in small groups,
without a miucilaginous investment...) "2 a ee 6
6Cf. the symbiotic genera Glaucocystis and Gloeochaete, in which the host cells may be
grouped in small families.
[ 444 ]
, Gells\ pear-shaped, radiately ‘arranged == Marssoniella
6. Cells some other shape, not radiately arranged —________________ io
7. Cells cylindrical and strongly curved through 7% of a circle,
often lying parallel and compact within the mucilage of other
algae; minute, O:o—l. in’ diameters = Cyanarcus
7. Cells ovate or oblong; larger, up to 15 in diameter__________ Synechococcus
8. Cells 10 or more times their diameter in length; cylindrical,
WGUSTCUNOH MATL, TREpOUU COHEN, (OVC TUB VUCO AON 9
82 Cells sound: ovate; or/Short-cy lind ric enna ee 1C
9. Cells narrowly fusiform, with tapering
aicl | POUL. APICES 2)... 5vs aes eee eee ee Dactylococcopsis
9. Cells reniform or vermiform, rounded at the apices_____________ Rhabdoderma
10. Cells oblong or short-cylindric, with rounded ends, many
10.
lige
doe
12.
12.
13.
13.
14.
14.
15.
15.
16.
16.
Wi
L7-
individuals irregularly and densely crowded in copious
mucilage; individual cell sheaths evident or not Anacystis (in part)
Including:
a. Aphanothece (see p. 465) with individual
cell sheaths not evident
b. Gloeothece with individual cell sheaths distinct
Cells spherical or ovate, sometimes ellipsoid, not cylindrical. 1]
Cells round, embedded in copious mucilage, and forming
shapeless masses on submerged or more
frequently aerial ‘substrates Gloeocapsa
Cells of other shapes, or if round not forming
Shapeless masses (00 «subspates ee 42
Cells round or ovate, dividing in 2 directions
fo, £ORm. Fectan Gul argyp late spteere oe eee 13
Cells dividing in 3 planes to form spherical,
ovate, Or Shapelessvealoumall masses ee 14
Cells regularly arranged in rectilinear series. Merismopedia
Cells irregularly arranged to form
Somewhat rectangulamsplates ee. 2 Holopedium
Colony hollow, the cells arranged toward the periphery 15
Colony not hollow; cells distributed throughout
the colonial smucilage: nn eS 16
Cells at the ends of branching gelatinous strands which radiate
from the center of the colony oe 12 Serle) nes a Gomphosphaeria
Colonies without radiating gelatinous strands______________. Coelosphaerium
Cells longer than wide, distributed throughout the colonial muci-
lage, with or without evident individual cell sheaths _____ Anacystis (in part)
Including:
a. Aphanothece (see p. 465) without evident cell sheaths
b. Gloeothece with individual cell sheaths evident
Gels» ‘globose 2s eS 17
Cells evenly and remotely distributed within the colonial
mucilage; pseudovacuoles wanting —_____--------------------------- Aphanocapsa
Cells crowded, usually very densely so, not evenly distributed
throughout the colonial mucilage;
pseudovacuoles usually present ____----------------------------------- Microcystis
CHROOCOCCUS Naegeli 1849, p. 45
One-celled, or an association of 2-32 spherical, hemispherical or
ovate individuals, either free-floating, adhering to submerged sub-
strates, or forming expansions in moist aerial habitats; each cell with
a sheath which may be distinct from or (as in most planktonic
species) confluent with the common mucilage investing a group of
cells; several generations of sheaths present as a result of successive
cell divisions; sheaths either hyaline or ochraceous; cell contents
homogeneous or granular, not vacuolate, light to bright blue-green,
olive-green, or yellowish.
The sedentary species, especially, should be compared with
Gloeocapsa, a genus which in some conditions and stages of develop-
ment might be confused easily with Chroococcus. Gloeocapsa forms
attached, gelatinous masses on either submerged substrates or, more
commonly, in aerial habitats. In Gloeocapsa, many more cells are
associated in families and clusters of families than in Chroococcus;
the individual cell sheaths are usually thick and conspicuous, and
the gelatinous matrix in which the cells are embedded is formed of
several concentric layers. A small, isolated, and little-developed
clump of Gloeocapsa resembles certain species of Chroococcus. It
is desirable, therefore, to see a number of plants in a collection
before attempting determinations.
Key to the Species
1. Cells large, 13-70 in diameter__—_-----—---_-----__--------------— 9)
iei@ellstsmaller, 1-5—10p in diameter Se 3
2. Maximum diameter of cell, including sheath, 504. C. turgidu
2. Cells larger, diameter 67—70y including the sheath ____ C. giganteus
3. Colonial mucilage or individual cell sheaths lamellate = ae 4
3. Colonial mucilage or individual cell sheaths not lamellate2 44 eee ber 5
4. Cells arranged in cubical (sarciniform) packets. C. Prescottii
4, Cells not in cubical packets _______—__________- C. varius
5. Cells arranged in cubical packets of from 4-8, or in multiple
packets of 32 cells in Sarcina-like families ____________. C. Prescottii
5. Cells not arranged in cubical packets 6
6. Colonies free-floating in the euplankton —____---______________-------- 7
6. Colonies adhering to substrates, or entangled
among other algae in tychoplankton —__-__-------------—---=-— 9
7. Colony of many cells within a homogeneous sheath,
cells: 2=2 iin: Giamete ts ie ee ee C. minimus
7. Colony of 24 or fewer cells in a homogeneous sheath, cells
usually more than 3 in diameter 8
8. Cells 8-4.5u in diameter, arranged at
some distance from one another. ........-----------—--—------------ C. dispersus
8. Cells 6-12—(22), in diameter, arranged close together C. limneticus
[ 446 ]
9. Cells (5)-G—8—(11)u in diameter; contents pale yellow. C. pallidus
9. Cells mostly smaller than above; contents blue-green —______________ 10
10. Cells oblong; 5-7—(10) in diameter; in groups of 2
inclosed in a homogeneous sheath_.._________________-__. C. minutus
10. Cells angular or irregularly globose, 3-44 in diameter; solitary
or 2 together within homogeneous sheaths, sometimes forming
small masses on submerged aquatic plants. —_------_-_- C. minor
Chroococcus dispersus (Keissl.) Lemmermann 1904, p. 102
PI. 100, Fie. 7
A free-floating, flattened, ovate or irregularly-shaped colony of
4-16 spherical cells which are either single or arranged in small
clusters, evenly distributed at some distance from one another in
the mucilaginous envelope; individual cell sheaths not evident; cell
contents bright blue-green (sometimes gray-green or pale blue-
green); cells 3-4.5, in diameter.
This species should be compared with C. limneticus, in which the
colonies are globular and the cells are larger.
Euplankter. Found in many lakes of both hard and soft water.
Mich., Wis.
Chroococcus dispersus var. minor G. M. Smith 1920, p. 28
Pl. 100, Figs. 1-3
A variety differing from the typical in having smaller cells, 1.7-
2.5 in diameter.
Rare, but has been found in several lakes. Mich., Wis.
Chroococcus giganteus W. West 1892, p. 741
Pl. 100, Fig. 16
Cells hemispherical or ovate, solitary or in groups of 2-5, inclosed
by a wide, hyaline, lamellate envelope of mucilage in which indi-
vidual cell sheaths are evident; cell contents bright blue-green and
densely granular; cells, without sheath, 54-58, in diameter, 67—70n
including the sheath.
This species is, by far, the largest of the genus in our region.
Except for its greater size it is not unlike C. turgidus with which it
should be compared. Specimens of C. giganteus collected in Vilas
County, Wisconsin, are so much like a large form of C. turgidus that
I am inclined to regard the former as a variety maximum of the latter.
Tychoplankter. Rare; in mixtures of other algae in shallow water.
Mich., Wis.
[ 447 ]
Chroococcus limneticus Lemmermann 1898d, p. 153
Pl. 100, Figs. 4, 5
A free-floating, spherical or ovate colony of 4-32 spherical cells
rather closely and evenly arranged, sometimes in groups of 2-4 cells
as a result of rapid cell division; individual cell sheath usually
indistinct and confluent with the hyaline, mucilaginous colonial
envelope; cell contents dull to bright blue-green, not conspicuously
granular; cells 6-12-22 in diameter, without sheath.
This is one of the most common of all planktonic species found
in our region. Its distribution in acid or soft water habitats suggests
a specificity similar to that of C. turgidus in the tychoplankton of
highly acid mediums.
Euplankter. Found in many lakes, especially soft or semi-soft
water. Mich., Wis.
Chroococcus limneticus var. carneus (Chod. )
Lemmermann 1904, p. 101
Pl. 100, Fig. 6
A variety differing from the typical by its smaller size and the
irregularity of cell distribution within the colonial envelope; cells
4-16 in number, 7-9, in diameter without sheath.
Euplankter. Found in several lakes. Mich., Wis.
Chroococcus limneticus var. distans G. M. Smith 1916, p. 481
Pl. 100, Fig. 8
A free-floating ovoid colony of 8-32 globose or hemispherical
cells, rather widely separated (or in widely separated groups of
individuals) within a hyaline; homogeneous, gelatinous colonial
envelope; cell sheaths confluent with the colonial mucilage; cell con-
tents homogeneous, gray to light blue-green; cells 6-8 in diameter.
Euplankter. Found in several soft water lakes. Mich., Wis.
Chroococcus limneticus var. elegans G. M. Smith 1916, p. 619
Pl. 100; Fig; 11
A free-floating colony of ovoid cells which are circular in one view
but flattened when seen from the side; cells irregularly scattered in
a wide, gelatinous colonial envelope; cell contents bright blue-green
and non-granular; cells 18-22, in diameter without sheaths, 20-26
in diameter including the sheath.
Euplankter. Mich., Wis.
[ 448 ]
Chroococcus limneticus var. subsalsus Lemmermann 1901c, p. 84
Pl. 100, Fig. 10
A globose or ovoid to ellipsoid colony of 8-32 spherical cells,
evenly scattered within a wide, hyaline, and homogeneous colonial
envelope of mucilage; individual cell sheaths not evident; cell con-
tents bright blue-green and non-granular; cells smaller than in the
typical plant, 3—4.5p in diameter without sheaths.
Euplankter. Found in a number of lakes; rare but widely distrib-
uted in our region. Mich., Wis.
Chroococcus minimus ( Keissl.) Lemmermann 1904, p. 102
A globose or elliptical colony of 4-8 spherical or ovoid cells in a
wide, hyaline, non-lamellated colonial envelope; cells 2-3» in diam-
eter without sheaths; contents blue-green, non-granular.
Euplankter. Wis.
Chroococcus minor (Kuetz.) Naegeli 1849, p. 47
Pl. 100, Fig. 12
A small gelatinous attached and amorphous mass in which cells
(spherical or angular from mutual compression) are irregularly
scattered, singly, in pairs, or in larger groups resulting from repeated
cell division; individual cell sheaths scarcely visible, confluent with
the colonial envelope; cell contents pale to bright blue-green, non-
granular; cells 3-4 in diameter without sheath.
Growing on moist substrates or intermingled with dense clots of
miscellaneous algae; often forming small masses on Potamogeton
spp. or other submerged aquatics; sometimes buried in the decaying
tissues of higher plants. Wis.
Chroococcus minutus (Kuetz.) Naegeli 1849, p. 46
Pl. 100, Fig. 9
A small, amorphous, mucilaginous mass in which spherical or
hemispherical cells are compactly arranged within a wide hyaline
envelope; individual cell sheaths indistinct, not lamellated; cell
contents blue-green, either homogeneous or finely granular; cells
5-7-(10)» in diameter without sheaths.
Common in a great variety of both hard and soft water lakes;
tychoplankter; found among dense growths of algae and higher
aquatics in shallow water of lakes, cut-offs from lakes, and in
swamps; sometimes appearing incidentally in tow samples from
Sphagnum bogs. Mich., Wis.
[ 449 ]
Chroococcus pallidus Naegeli 1849, p. 46
Pl. 100, Fig. 14
Single-celled or, more frequently, a small colony of 2-4-(8)
spherical individuals inclosed by an oval or globose, wide, hyaline
or yellowish, homogeneous envelope of mucilage; individual cell
sheaths indistinct; contents pale blue-green; cells (5)-6-11p in
diameter without sheath.
Plants of this species are to be found on moist aerial substrates
or scattered among algae in shallow water tychoplankton. Mich., Wis.
Chroococcus Prescottii Drouet & Daily in
Drouet 1942, p. 127
P1.100, Fig. 13
A free-floating colony of 4-16-32 spherical cells arranged in 2
planes to form cubes or sarciniform clusters, inclosed in a rectan-
gularly shaped, hyaline, colonial envelope which is often lamellated,
with individual cells or quartets of cells inclosed by a sheath; cell
contents bright blue-green; finely granular, cells 5-8» in diameter;
colony (of 16 cells) 18-224 wide, 30-42 long, and about as thick
as wide.
This plant was questionably listed as Eucapsis alpina Clements
and Schantz by Prescott and Croasdale (1937). It should be com-
pared with that species, the cells of which are similarly arranged
but more numerous in the colony and in which the colonial sheath
is without lamellations.
Not uncommon in the tychoplankton of acid habitats, intermin-
gled with dense growths of other algae, especially desmids, and
commonly associated with C. turgidus. Mich., Wis.
Chroococcus turgidus (Kuetz.) Naegeli 1849, p. 46
Pl. 100, Fig. 19
A free-floating colony of 2-4 ovoid or hemispherical cells inclosed
by a very wide (usually), hyaline, and lamellate colonial sheath;
cells bright blue-green, contents sometimes coarsely granular, in-
closed by individual sheaths, 8-324 in diameter without sheath,
15-50, wide including sheath.
Tychoplankter. Common in many lakes and in bogs. This is a
relatively large species, attaining maximum size and abundance in
Sphagnum bogs. Mich., Wis.
[ 450 J
Chroococcus varius A. Braun in Rabenhorst
1861-1878, Nos. 246, 248, 252
Pl. 100, Fig. 15
An irregularly shaped colony of 2-8 spherical cells inclosed by a
hyaline, sometimes colored, gelatinous envelope, forming dark-green
or brownish masses on moist aerial substrates, or among other algae
in shallow water; colonial envelope lightly lamellate, individual cell
sheaths not distinctly evident; cell contents blue-green or olive, not
granular; cells 2-4 in diameter.
Most of the records of this species in North America are from
moist substrates near geysers and hot springs, or from sulphur water.
Not infrequent in the tychoplankton of a variety of both hard and
soft water lakes. Wis.
GLOEOCAPSA Kuetzing 1843, p. 174
Essentially unicellular but with many individuals aggregated to
form amorphous gelatinous masses of spherical cells, or as associa-
tions of families of irregularly arranged cells, each individual in-
closed by a lamellate, mucilaginous, and usually thick sheath; plant
mass blue-green, reddish; yellowish, or brown; cell contents blue-
green or yellowish to olive-green, homogeneous or (more often)
granular, without pseudovacuoles.
This genus should be compared with those attached or sedentary
species of Chroococcus in which the colonial envelopes of the
families are persistent and do not become confluent with the general
investing mucilage. In general, Gloeocapsa masses contain many
more cells than Chroococcus, and the lamellate, thicker sheaths are
more conspicuous, whereas in some (especially planktonic) species
of the latter genus they tend to become confluent.
Key to the Species
1. Sheaths yellowish or brownish to orange_______-_----------------------- G. rupestris
ee Sheathiscaeo lor es sess sein te he week eer eC Dee el 9
2. Cells 6—9u in diameter without sheaths, 11—-12u
ATUL ATIVE CE TERWVA EELS res this fae aeeaeeae ea cn ene ere G. calcarea
Cals: Srrvaill eer eee eo ee ae ioe aL 8
. Plants encrusting on moist substrates; cells 2-4y in diameter __ G. aeruginosa
. Plants free-floating (tychoplankton ); cells
0:7=2:8a: in- diameter 2 a ee G. punctata
woh
Gloeocapsa aeruginosa (Carm.) Kuetzing
1845-1849, Tab. Phyc., Pl. 21, Fig. 2
Pl. 101, Fig. 6
Plant mass with firm or leathery mucilage, blue-green; cells
spherical, with blue-green, homogeneous contents, arranged in small
[ 451 ]
families and inclosed by wide, colorless sheaths which are only
slightly lamellate; cells 2-4 in diameter, with sheaths 4-8 wide.
On shore and in tychoplankton of shallow lake. Mich., Wis.
Gloeocapsa calcarea Tilden 1898, p. 29
Plant mass light gray-green to blue-green, forming a calcareous
crust on moist substrates; cells spherical, in families of 4-16 indi-
viduals inclosed in thin, colorless sheaths, 6-9, in diameter, with
sheaths 11-12 wide.
On wet boards, Osceola, Wisconsin.
Gloeocapsa punctata Naegeli 1849, p. 51
Pl. 101, Fig. 7
Plant mass blue-green, floating or entangled among other algae,
consisting of small aggregates of 4-16 individuals which are spher-
ical and inclosed by thick sheaths that are weakly lamellate out-
wardly but which break down and become confluent with the
colonial mucilage internally; cells 0.75-2.31 in diameter; contents
blue-green, homogeneous.
This species may be identical with G. aurata Stiz., a species
described as having yellowish envelopes that are not lamellate.
Sheath color and presence or absence of lamellatigns seem to be
such variable characters that alone they are inadequate for the
separation of species.
On soil and in tychoplankton of soft water lakes. Wis.
Gloeocapsa rupestris Kuetzing 1845-1849, Tab. Phyc., 1, p. 17
Pl. 107, Fig. 13
Plant mass dark-colored, brownish, encrusting; cells blue-green,
spherical, in few-celled colonies; cell sheaths thick and but slightly
lamellated, yellowish or orange-brown; cells 6-9. in diameter;
families 15-75, in diameter.
Mich.
APHANOCAPSA Naegeli 1849, p. 52
A globular, ovate, or sometimes amorphous mass, gelatinous, and
free-floating, in which spherical cells are usually widely and evenly
distributed through a yellowish or hyaline, homogeneous colonial
mucilage; individual cell sheaths not evident; cells often in pairs
as a result of recent division; contents homogeneous or finely gran-
ular, pale gray-green to bright blue-green. See description of Micro-
cystis, page 455.
[ 452 ]
These plants are common in plankton and frequently appear with
Microcystis aeruginosa in water blooms, but they never become
dominant components of such blooms in our region. Most species
show a preference for soft water and acid habitats.
Key to the Species
1. Cell endophytic in the mucilage of other algae____-_»»_=_ A. endophytica
deg @elishiree=biviri tf... a2 ee ee eee se A a te 2
2. Cells 5-6u in diameter, colony usually free-floating,
Sometimess attached —-..-2 5 sx 2u 5 00 Bae eRe A. rivularis
Orn@ellsismiallereek 2:1 > eee Dee ernie dio ete hd 8
3. Cells bright blue-green; rather crowded ___.-_____-__________ A. Grevillei
3. Cells gray-green or bluish-green, colonial mass not deeply colored;
cells not crowded (except var. conferta of A. elachista) -_-__________- 4
Al. (Calls Gs 2Mbyn, aio, Glieionetnere A. pulchra
4\. (Calls less Gein, Syn tin Ghtimneter 5
5. Cells minute, coccoid, lu in diameter or less = A. delicatissima
i, Calls Tg olen ty Gliese A. elachista
Aphanocapsa delicatissima West & West 1912, p. 431
Pl. 101, Figs. 8, 9
Colonies spherical or elliptical, free-floating; cells minute, bluish,
evenly distributed throughout copious, colorless mucilage, 0.5-0.8p
in diameter.
Common in the tychoplankton of many lakes. Most frequent in
soft or acid water. Mich., Wis.
Aphanocapsa elachista West & West 1895b, p. 276
Colonies spherical or ellipsoid, free-floating or intermingled with
other algae, small and few-celled, the colonial mass pale blue-green;
cells small, globose, often in pairs and widely separated in colorless
mucilage, 1.5-2.5, in diameter.
Mich., Wis.
Aphanocapsa elachista var. conferta West & West 1912, p. 432
PL JO Bigs. 10,07
Colonies ovate or globose, frequently irregular in shape (in our
specimens commonly very large) up to 150» in diameter; cells
spherical, crowded within a hyaline colonial mucilage, often with
many cells in pairs, 1.6-2.0y in diameter.
Euplankter. Rare to common in several soft water lakes. Mich.,
Wis.
[ 453 ]
Aphanocapsa elachista var. planctonica G. M. Smith 1920, p. 42
Pl. 101, Fig. 12
Cells less crowded than in var. conferta, evenly dispersed through-
out a colorless, colonial mucilage, 2-3» in diameter.
Euplankter. Rare in several, mostly soft water, lakes. Mich., Wis.
Aphanocapsa endophytica G. M. Smith 1920, p. 42
Pl. 101, Fig. 18
Endophytic in the colonial mucilage of Microcystis; cells solitary or
arranged in small clumps which are evenly dispersed and remote
from one another; cell contents homogeneous, pale to bright blue-
green; cell 2u in diameter.
Reported as common in Poor Farm Lake, Wisconsin.
Aphanocapsa Grevillei (Hass. ) Rabenhorst 1865, p. 50
Pl10U Figs. lo, 16
Free-floating colonies, sometimes on moist soil, spherical or, in
age, irregularly shaped; cells in pairs, in groups of four and crowded,
or solitary, evenly dispersed through colorless mucilage, blue-green,
with pseudovacuoles, 3.8-5.5u in diameter.
Rare; in the tychoplankton of several lakes. Mich., Wis.
Aphanocapsa pulchra (Kuetz.) Rabenhorst 1865, p. 49
Pl. 101, Fig. 14
Colonies ovate or globose, free-floating; cells spherical, loosely
and evenly dispersed within a copious mucilage, contents blue-
green, finely granular, 3.4-4.5u in diameter.
This is the most common species of the genus in our collections
of phytoplankters. It is often a component of water blooms in hard
water lakes although not infrequently found intermingled and
attached among other algae in shallow water of Sphagnum bogs.
The colonies often attain macroscopic size. Mich., Wis.
Aphanocapsa rivularis (Carm.) Rabenhorst 1865, p. 49
Pl 101. Pigs 17
A free-floating or sessile, amorphous, or tubular to spherical
colony of globose cells which have bright blue-green, granular
contents; cells solitary or in pairs and scattered at some distance
from one another within the colonial mucilage; cells 5-6 in diameter.
The slightly larger size of the cells, and the more scattered ar-
rangement separate this species from A. Grevillei.
Euplankter. Mich., Wis.
[ 454 ]
MICROCYSTIS Kuetzing 1833a, p. 372"
A free-floating or sedentary colony of numerous spherical cells
closely and irregularly arranged within copious mucilage, forming
ovate, globose, or irregularly shaped masses which are often lacerate
or perforate; individual cell sheaths confluent with the colonial
mucilage; cell contents pale or bright blue-green, or appearing
black or purplish because of pseudovacuoles, present in most species,
which are large and conspicuous, or sometimes numerous and small.
This genus should be compared with Aphanocapsa in which the
spherical cells are evenly and widely spaced within a definitely
shaped (usually spherical ) colonial investment of mucilage. Unlike
most of the species of Microcystis, the cells of Aphanocapsa are
always without pseudovacuoles.
The reader is referred to Elenkin (1924), to Drouet and Daily
(1939), and to Teiling (1946), for critical remarks on the synonymy
of species in this genus. In the following key those species which
have been reassigned by students of the genus are given in paren-
theses.
Key to the Species
1. Colonies saccate, lobed and clathrate, the colonial mucilage
thick and! refractiveum young, plats .- 2 =) M. aeruginosa
1. Colonies globular, or ovate, definite in shape,
notepertorate’ OL CLAuanated ee ee SE ee 2
2. Cells without pseudovacuoles or, if present,
simall Rand MnCOris pico tis eee nee ae ee es ee 4
2. Cells with large and conspicuous pseudovacuoles 3)
3. Colonies simple, a large mass of much crowded cells inclosed
by a transparent, mucilaginous envelope PS coal (M. flos-aquae )
M. aeruginosa
3. Colonies compound, several groups of cells, each with a colonial
envelope, inclosed within a common mucilage (M. ichthyoblabe )
M. aeruginosa
4. Cells 1-2u in diameter, small and numerous but uniformly
distributed within the enlonial AUC ASE 4s 30) hat een SEs M. incerta
4. Cells 2-3u in diameter, compactly arranged
within, the colonial mucilage ose eee eS (M. pulverea)
M. incerta
7See notes by Drouet and Daily (Daily, 1942, p. 638) in which they explain the use of the
generic name Polycystis Kuetz. for the species grouped under Microcystis Kuetz. I prefer to
retain the latter name because it is generally accepted and well understood. Although
Microcystis was used originally for a miscellany of organisms, and at one time only for
flagellates, those species to which it referred in earlier times have all been transferred to
their proper places in other genera. Since the name Microcystis no longer applies to any of
them, there is no danger of taxonomic confusion. In any case, the creation of Polycystis as
a genus by Kuetzing in 1849 was antedated by the use of that name for a genus of
Uredineae (Polycystis Leveille 1846, Annales Sci. Nat. Bot., 5 (Ser. 3), p. 269). This
precludes the revival of the name for the species now grouped under Microcystis.
[ 455 ]
Microcystis aeruginosa Kuetz.; emend. Elenkin 1924, p. 14
[M. aeruginosa var. major G. M. Smith; M. flos-aquae
(Wittr.) Kirchner; M. ichthyoblabe Kuetzing]
Pl. 102, Figs. 1-4
An ovate, spherical, or irregularly lobed, saccate and clathrate
colony of numerous spherical cells which are much crowded within
a gelatinous matrix (several colonies sometimes invested by a com-
mon tegument); colonial mucilage hyaline and homogeneous, re-
taining a definite shape; cell contents blue-green, highly granular
and with conspicuous pseudovacuoles; cells 3-4.5u in diameter.
Very common in hard water lakes, becoming especially abundant
during late summer periods and appearing in such dense growths
in favorable habitats as to color the water. Mich., Wis.
This species is a frequent component of water blooms, especially
in lakes with eutrophic characteristics, although it is common to a
great variety of aquatic habitats. The tendency to float high in the
water results in the formation of large, macroscopic clots and floating
crusts which develop as the plants push each other above the
surface. Like Aphanizomenon flos-aquae, this species is notorious as
a spoiler of water for domestic uses, swimming, and recreation and
often causes the death of fish in heavily infested lakes.
In assigning species of Microcystis collected in this region, I have
followed the nomenclature recommended by students who have
given special attention to the genus. There long have been recog-
nized two species names for the very common planktonic forms of
Microcystis, which show considerable variation in colony form.
The name M. aeruginosa Kuetz. has been used for the plant which
has a perforated or clathrate and much lobed colony. The name
M. flos-aquae (Wittr.) Kirch. has been applied to the form with
globose, non-perforate or non-clathrate colonies. Elenkin (1924, p:
14), after a critical study, reduced this latter species to synonymy
with M. aeruginosa Kuetz. At the same time he recognized two
forms: fa. minor Elenkin, cells 3-54 in diameter, and fa. major
( Wittr.) Elenkin, cells 4-7, in diameter. It is held by some that the
perforate condition of the colony is merely a character accompany-
ing age and that the many intergrading variations are related to
physical conditions in the habitat such as water currents, or to
methods of collecting. Virieux (1916) and others (Drouet and
Daily, 1939) also have advocated uniting M. aeruginosa and M.
flos-aquae. Drouet and Daily (I.c.) have published on the synonymy
of Microcystis aeruginosa and have discussed the fresh-water species
[ 456 ]
of the genus critically. Teiling (1946) advocates the retention of
the two names.
If the interpretations of Elenkin (J.c.), Drouet and Daily (l.c.)
and others are followed, the name M. flos-aquae (Wittr.) Kirch.
will be discarded. The view which holds that the clathrate condition
is a result of age only, is not compatible with the many observations
which I have made on collections of these forms in which very
large, globose, solid colonies dominate the habitat, forming almost
pure growths in some lakes. Such colonies mature and disintegrate
without assuming the perforate and clathrate condition which one
might expect to develop if age were responsible for the aeruginosa
form. Illustrations of some of the various expressions which this
plankter assumes are illustrated on Plate 102, Figs. 1-4. See also
Fjerdingstad (1945) on the retention of these two names.
Microcystis incerta Lemmermann 1899a, p. 132
[M. pulverea (Wood) Migula]
Pl. 102, Fig. 5
A spherical or lobed colony, consisting usually of many small,
spherical, closely arranged cells, inclosed by a thin, mucilaginous
envelope; cells 0.5-2» in diameter; cell contents gray-green to light
blue-green; pseudovacuoles lacking or minute and inconspicuous;
colonies either tychoplanktonic, or forming blue-green granular
masses on the bottom.
Not uncommon, occurring in both hard and soft water lakes.
Mich., Wis.
The small size and compact arrangement of the cells, and the
minute pseudovacuoles are characteristics which aid in the identi-
fication of this species.
I follow Drouet and Daily (l.c.) in assigning forms ordinarily
listed under the name of M. pulverea (Wood) Migula to M. incerta
Lemm. The plant listed by other authors as Anacystis pulverea Wolle
has been transferred to M. glauca (Wolle) by Drouet and Daily
(I.c.). Apparently it has ‘not been collected in our region. It inhabits
hard water lakes rich in lime and is to be expected in lakes of
southern Michigan and Wisconsin.
MERISMOPEDIA Meyen 1839, p. 67
A plate-like colony of ovate or globose cells compactly or loosely
arranged in rows both transversely and longitudinally, inclosed by
a hyaline, homogeneous, mucilage; colony quadrangular (becoming
distorted in age) or with margins rolled and convolute; cell contents
homogeneous (rarely with pseudovacuoles ); individual cell sheaths
[ 457 ]
indistinct in most species and confluent with the colonial mucilage.
The plate-like form of the Merismopedia colony and the regularity
of cell arrangement make identification of this genus certain. Only
in rare instances are Chroococcus cells found in a somewhat plate-
like colony, and the examination of a number of individuals will
confirm the identification.
Key to the Species
1. Colony a very broad, membranaceous plate with
imarcins convolute-and :enrolleds el. sass ERE Aen ese M. convoluta
1. Colony: ‘a; flat plate 240 Gers bon er oe eee eee eee 2
2Gellsiwithretractivesvacuo lesi a. => 45 0e.0 32 522 ia ee ae 6
5. Cells 1-1.5u in diameter, about twice the diameter in length A. nidulans
5. Cells larger, (1)—1.8-2u in diameter, slender, up to
Sitimes: the diameter inilength «12 Ae) es BE A. saxicola
6. Cells ovate to nearly spherical, not cylindric -___._________. A. gelatinosa
6. Cells cylindrical, up to 3 times the diameter in length .____________»______ a
7. Plant mass very pale, gray to light blue-green_______________ 8
ice Blantemassi brig latly Colored 2.5 ee teens a See eee ee 9
8. Cells 3.3-3.7—(4.5) in diameter, up to Tu
long-sdensely ramamced. ies seaee ee title 52 ee A. microscopica
8. Cells larger, 4.5-5.6u in diameter, up to
8.54 long; loosely arranged... (A. pallida—see Gloeothece rupestris )
Anacystis rupestris
9. Cells elongate-cylindric, 2.4—-3u in diameter, up to 3
times the diameter in length; loosely arranged_.____________ A. microspora
9. Cells short-cylindric, 2-83.54 in diameter, up to 2 times the
diameter in length; densely arranged_________________ (A. Castagnei )
Anacystis marginata
[ 466 ]
Aphanothece Castagnei (de Bréb.) Rabenhorst 1865, p. 76
[Anacystis marginata Meneghini 1837]
Pl. 105, Figs. 5, 6
Cells ellipsoid or ovate to subcylindric, densely arranged within
a gelatinous, amorphous mass which is olive-green or brownish; cells
of various shapes and sizes within the same colony, oblong or poly-
gonal when compressed; 2-3.5p in diameter, 4-8» long; cell contents
finely granular and olive-green.
In ditches; in tychoplankton of lakes. Wis.
Aphanothece clathrata G. S. West in West & West 1906, p. 111
Pl. 104, Figs. 6, 7
Colonies free-floating, irregular in shape and usually clathrate
with large perforations; cells cylindrical or elongate-elliptic, straight
or slightly curved, scattered through a transparent mucilage; cells
0.8-1.2u in diameter, 3-6, long.
The small size of this species and the clathrate colony are char-
acters which separate this species from most of the other free-floating
forms of Aphanothece. Its lack of pseudovacuoles differentiates it
from A. pulverulenta Bachmann, another species with minute cells
(ellipsoid in shape) which possess pseudovacuoles.
Floating in several soft water lakes. Mich., Wis.
Aphanothece gelatinosa (Henn.) Lemmermann 1910, p. 69
Pl. 104, Fig. 8
Cells ovate, nearly spherical, compactly arranged in globular,
blue-green to brown gelatinous attached masses; cell contents blue-
green; cells 3.8—4y in diameter, 44.5, long.
This plant is differentiated by the color of the colonial mass and
by the size of the cells from Aphanothece stagnina. It is possibly
only a variation of that species, and the assigned name is used here
tentatively to designate a form which does not agree with typical
A. stagnina. I have not seen type specimens of A. gelatinosa for
comparison.
In a hard water swamp and in lakes with a high calcium carbonate
content. Wis.
Aphanothece microscopica Naegeli 1849, p. 59
Pl. 104, Figs. 9, 10
Cells ovate to subglobose, densely arranged in small, free-floating
or attached ovate colonies; cell sheaths not evident; cell contents
[ 467 ]
light blue-green, finely granular; cells 3.3-3.7-(4.5) in diameter,
5.5-7.5p long.
This plant has smaller cells than those described for Aphanothece
prasina, and they are not cylindrical.
Euplankter. Mich., Wis.
Aphanothece microspora (Menegh. ) Rabenhorst 1863, p. 76
Pl. 105, Figs. 7-9
Cells short-cylindric with rounded ends, loosely arranged, solitary
or in pairs in small, amorphous, olive or yellow-green gelatinous
masses; cells 2.4-2.7 in diameter, 6-10, long.
Fairly abundant in a few hard water lakes; entangled in tycho-
plankton, among filamentous algae. Wis.
Aphanothece nidulans P. Richter 1884, p. 128
Pl. 104, Figs. 2,3
Cells short-cylindric, broadly rounded at the apices, densely and
evenly distributed in small ovate or spherical colonies, inclosed by
a colorless mucilage in which individual cell sheaths are not distinct;
cells small, 1-1.54 in diameter, 3-3.5y long; cell contents pale blue-
reen.
: This is a euplanktonic species, often forming a major portion of
a rich flocculent algal population in shallow water, especially in
hard water lakes. The minute bacilliform cells give colonies the
appearance of a bacterioidal mass. Mich., Wis.
Aphanothece nidulans var. endophytica West & West 1912, p. 482
Pl. 105, Fig. 16
Cells within the mucilage of other colonial Cyanophyta, such as
Coelosphaerium and Microcystis, where they are evenly distributed
throughout the envelope of the host; cells 0.8-1.54 in diameter,
2.54.5 long.
Rare; in the euplankton of lakes of fairly soft water. Wis.
Aphanothece saxicola Naegeli 1849, p. 60
Pl. 104, Fig. 1
Cells cylindrical with rounded ends, 2—3.5 times longer than wide,
loosely arranged, solitary or in pairs within amorphous, homo-
geneous, and almost colorless mucilage; colonies free-floating or
attached; cell contents pale blue-green; cells (1)-1.5-1.8-(2)p in
diameter, 2.8-6y long.
The cells of this species are bacilliform and are almost colorless.
[ 468 ]
Because of their minute size they may easily be mistaken for a
colony of bacteria. Their faint bluish-green pigmentation is scarcely
to be differentiated from the apparently similar color of unstained
bacteria caused by light refraction in microscopical examination.
The name A. saxicola Naeg. is used tentatively for this small plant.
It is nearest A. nidulans P. Richt. in size but is more slender and
the cells are more loosely arranged in the colonial mucilage than
described for A. nidulans. According to Drouet and Daily (l.c.)
Aphanothece saxicola is synonymous with Anacystis marginata Men-
eghini, the original description of which does not agree with our
specimens. The former name is used here, therefore, to refer to a
plant which agrees with the description of A. saxicola.
In Sphagnum bogs; tychoplankter in lakes. Mich., Wis.
Aphanothece stagnina (Spreng.) A. Braun in Rabenhorst
1864-1869, Algen No. 1572
[Anacystis rupestris (Lyngb.) Drouet & Daily in Daily 1942, p. 650]
Pl. 103, Figs. 14-16
Cells short cylindric, evenly distributed throughout an ovate or
irregularly globose gelatinous mass; colonies bright green, attached
and attaining macroscopic size; cell contents usually bright blue-
green (sometimes pale), homogeneous; cells sheaths diffuent and
not evident; cells 3.7—7 in diameter, 5—8p long.
Free-floating colonies with larger cells are usually referred to
Aphanothece prasina A. Braun. In his treatment of the genus, Daily
has assigned the name Anacystis rupestris var. prasina (A. Braun )
Drouet & Daily to this form and does not separate it from Aphano-
thece stagnina (Spreng.) A. Braun.
Common in many lakes; usually in shallow water; often forming
almost continuous gelatinous expanses on the bottom of favorable
eutrophic habitats. Mich., Wis.
COELOSPHAERIUM Naegeli 1849, p. 54
A free-floating, globular, ovate, or irregularly shaped colony of
spherical or subpyriform cells arranged in the colonial mucilage, in
a single peripheral layer, producing a hollow sac; cell contents pale
to bright blue-green, either homogeneous or with numerous refrac-
tive pseudovacuoles; colonial envelope homogeneous, or with radiat-
ing, gelatinous fibrils.
This genus should be compared with Aphanocapsa, in which the
cells are scattered throughout the colonial mucilage.
[| 469 ]
Key to the Species
i (Cells: 5—Fupin; Gtameter, ‘spherical. 22) 5 ee C. dubium
i. (Gellsesmaller. either sphericalior ovate 2 sss ee 2
ZuCellssround, wp tor4 wai diameters sss =e eee ea C. Kuetzingianum
2. Cellssovate tovellitysoic sea Stee eo Rae ei ee ee ed eden Ces 3
3. Cells appearing dark and granular because of pseudovacuoles;
2—suein CiaMeten, S;0-Ou) ONG = at cates eee ee C. Naegelianum
3. Cells pale blue-green, without pseudovacuoles,
1[2)5pein.diameter; 2—3:2)¢ long) = 0514 Ae ae C. pallidum
Coelosphaerium dubium Grunow in Rabenhorst 1865, p. 55
Pl. 106, Fig. 1
Plant a spherical or sometimes irregularly-shaped colony of spher-
ical cells, or an aggregate of colonies in a common gelatinous enve-
lope; free-floating; cells densely arranged in the colonial mucilage
to form a peripheral layer, thus producing a hollow sphere; cell
contents blue-green, either homogeneous or with pseudovacuoles;
cells 5-7y in diameter; compound colonies as much as 300y in
diameter.
Rare in euplankton. Wis.
Coelosphaerium Kuetzingianum Naegeli 1849, p. 54
Pl. 106, Fig. 2
A free-floating spherical, or ovate, gelatinous colony of spherical
or subspherical cells arranged at some distance from one another
(usually) at the periphery of the colonial envelope; cell contents
homogeneous (rarely with pseudovacuoles ), light blue-green; cells
2.5—4u in diameter.
This species is not quite so common in our collections as C.
Naegelianum. It is, however, widely distributed in a variety of lakes,
mostly hard or semi-hard water habitats. It seems never to become
conspicuous in water blooms as does C. Naegelianum. It is to be
differentiated from that species by the shape of the cells and by
their lack of the reddish-brown color produced by many pseudo-
vacuoles. It also lacks the radiating gelatinous fibrils in the colonial
mucilage possessed by C. Naegelianum.
Mich., Wis.
Coelosphaerium Naegelianum Unger 1854, p. 196
Pl. 106, Fig. 4
A free-floating, spherical, ovate, or lobed colony of ovate or
ellipsoid cells arranged to form a dense peripheral layer in the
[ 470 ]
colonial mucilage; cell contents with many pseudovacuoles, giving
a dark reddish-brown or black granular appearance to the cell and
making the colony opaque when viewed microscopically; colonial
mucilage with many radiating fibrillar concretions which clearly
show when the colony disintegrates with age; cells 2-34 wide, 3.5-6
long.
This species is very common and occurs in abundance in suitable
habitats such as hard water, highly nitrogenous lakes with adequate
carbon dioxide content. In late summer periods these plants are
often conspicuous components of water blooms. Coelosphaerium
Naegelianum Unger is associated with Microcystis aeruginosa
Kuetzing emend. Elenkin, Lyngbya Birgei G. M. Smith, Coelo-
sphaerium Kuetzingianum Naeg. and Gloeotrichia echinulata (J. E.
Smith) P. Richter (see C. Kuetzingianum above). When the colony
is disintegrating the cells and the fibrils have a distinct radiate
appearance and the cells seem to be at the ends of fine strands
from the center of the colony.
The original description of this plant agrees with our specimens.
In DeToni (1907, p. 100), the name is regarded as synonymous with
C. Kuetzingianum Naeg.
Coelosphaerium pallidum Lemmermann 1898d, p. 154
Pl. 106, Fig. 3
A spherical or ovate colony of small, ovate cells crowded, but
evenly arranged, within the periphery of the colonial mucilage; cell
contents pale blue-green, without pseudovacuoles; cells 1-2.5y in
diameter, 2-3.2 long; colony 30-40, in diameter.
This species has smaller and more crowded cells than others in
our collections. These characters, together with the lack of pseudo-
vacuoles, are sufficient for identification.
Rare. Found in a Sphagnum bog and in pooled streams. Wis.
MARSSONIELLA Lemmermann 1900d, p. 275
A colony of 8-12 ovoid or pyriform cells, radiately arranged, with
their narrow ends directed outward, inclosed by a thin, transparent,
scarcely discernible investment (usually requiring a stain to demon-
strate).
Marssoniella elegans Lemmermann 1900d, p. 275
P]. 107, Fig. 12
Characteristics as described for the genus; cells 1.3-5p in diam-
eter, 5-6 long.
Euplankter. Mich.
[ 471 ]
GOMPHOSPHAERIA Kuetzing 1836, Dec. XVI, No. 151
A globose or ovate colony of globular or pyriform cells arranged
singly or in pairs at the ends of gelatinous strands which radiate
from a common center, the cells at the periphery of a colorless,
mucilaginous envelope; individual sheaths of the cells usually con-
fluent.
Following cell division in this genus, the cells lie side by side in
pairs (or in 4’s) for some time. The division is accompanied by a
forking of the stalk at base of cell, which thus forms the radiating
branched stalks of the colony. The cells, especially in some species,
appear heart-shaped because fission begins at the outer, free pole
of the cell, whereas division of the attached end of the cell is delayed.
Key to the Species
Cells 4-12 in diameter (some varieties
smallen))wpyxitonm oncordate =). = SIRES NRE ae G. aponina
Cells 1.5-2.44 in diameter, spherical or somewhat reniform G. lacustris
Gomphosphaeria aponina Kuetzing 1836, Dec. XVI, No. 151
Pl. 106, Fig. 5
Cells pyriform, or cordate in stages of division, arranged at the
periphery of a globular and usually wide gelatinous sheath, and at
the ends of stout radiating, gelatinous strands; cells 4-5y in diam-
eter, 8-12, long.
Tychoplankter; common in many lakes. Mich., Wis.
Gomphosphaeria aponina var. cordiformis Wolle 1882,
Bull. Torr. Bot. Club, 9, p. 25
PI? 106), Fig:'6
Cells decidedly cordate, compactly arranged within a thick gela-
tinous envelope, individual sheaths distinct; cells 6-12» in diameter,
12-15—-( 20)» long.
Occurring with the typical plant. Mich., Wis.
Gomphosphaeria aponina var. delicatula Virieux 1916, p- 69
Pl. 106, Fig. 7
A variety differing from the typical by the smaller size of the
cells, which are 2-3.51 in diameter, 4.5-6. long; colonies globose
or ovate and often lobed.
Euplankter; uncommon. Wis.
[ 472 ]
Gomphosphaeria aponina var. gelatinosa Prescott
in Prescott, Silva, & Wade 1949, p. 89
Pl. 106, Fig. 10
Cells pyriform, arranged in 2’s and 4's in multiple, irregularly
lobed or vermiform colonies, each group of cells entirely or partially
enclosed by a thick gelatinous integument, the radiating gelatinous
strands common to the typical form not in evidence; cells 3.7—4p in
diameter, 6-7.4, long.
This variety should be compared with Gomphosphaeria aponina
var. multiplex Nygaard.
Plankter; in soft water lakes. Wis.
Gomphosphaeria lacustris Chodat 1898, p. 180
Pl. 106, Fig. 9
Cells spherical or sometimes reniform, arranged in clusters of
4-8 individuals at the ends of fine gelatinous strands, clusters at
some distance from one another in copious gelatinous envelopes;
cells 1.5-2.4u in diameter.
This species is sometimes abundant as a euplankter, but it is more
commonly found among other algae in the tychoplankton. Although
generally distributed, this species seems to prefer hard or semi-hard
water lakes. It should be compared with Coelosphaerium Kuetzing-
ianum.
Euplankter. Mich., Wis.
Gomphosphaeria lacustris var. compacta Lemmermann 1900, p. 339
| Pl. 106, Fig. 8
Cells oblong, very compactly arranged within a wide, gelatinous
envelope, 1.5-2.0, in diameter, 4-6» long.
Rather common in the euplankton of both hard and soft water
lakes. Wis.
GLAUCOCYSTIS Itzigsohn, No. 1935 in Rabenhorst 1866,
Die Algen Europas; emend. Geitler 1923a
A colony of 4-16 cells inclosed by the persistent mother cell wall
(as in Oocystis); cells spherical or ellipsoidal, containing numerous
vermiform or sometimes irregularly shaped chromatophore-like
bodies which may be either peripheral or somewhat radiating and
axially arranged.
This interesting plant is now interpreted by most students of algae
as a colorless member of the Oocystaceae (Chlorophyta ) containing
protoplasts which belong to the Chroococcaceae. It is a little-
[ 473 ]
understood genus and rather rare, although some species seem to
be widely distributed. There appears to be some confusion in the
records of the plants assigned to the type species, G. Nostochin-
earum. Evidence at hand appears to warrant the separation of
spherical from elliptical plants and the assignment of only the latter
to the type species if they possess vermiform, radiating “chromato-
phores. See Geitler (1923a) and Hieronymus (1892a) on the
morphology of these plants.
Key to the Species
Ms Gels ellijascic atl sas celses 0 ee Dae ee hE SO 2
ly: elisesplherica es sia otec22 Magla Sao 2 eo eS one Eee G. duple
2. Cells broadly elliptical with nodular thickenings
at the poles® :..0i\ eis oc Uw y PE See ie eee G. oocystiformis
2. Cells elliptical, without nodular thickenings
ab tne ppOles aime ki ss see NEE ute Ee) Sates Fe oe G. Nostochinearum
Glaucocystis duplex Prescott 1944, p. 371
PI. 108, Fig. 1
Colony composed of 8-16 spherical cells inclosed by a much
enlarged spherical mother cell wall; chromatophore-like bodies in
the form of 2 stellate masses with long or short vermiform blue-
green protoplasts radiating from 2 separate points; cells 40-44, in
diameter; colony 150-170, in diameter.
This species differs from G. Nostochinearum by its spherical shape
and by the dual arrangement of the colored protoplasts. From G.
cingulata Bohlin it differs in the morphology of the cell wall. In
that species the cells are spherical, but the wall has a median an-
nular thickening. The chromatophores are numerous and parietal.
Some forms of G. Nostochinearum are described as spherical, but
other features which they possess seem to warrant the assignment
of the Wisconsin plants described above to a different species.
Among dense clots of algae in Manitowish River, Wisconsin.
Glaucocystis Nostochinearum (Itz.) Rabenhorst 1868, p. 417
PI. 108, Fig. 2
A free-floating colony of 4-8 elliptical cells inclosed by the old
mother cell wall; chromatophores axial and stellate in arrangement,
bright blue-green; host cell reproducing by autospore formation;
cells 10-18, in diameter, 18—23.4-(28), long; colony of 4 individ-
uals up to 50, long.
Intermingled with miscellaneous algae in soft water ponds and
acid swamps; especially common in desmid habitats. Wis.
[ 474 ]
Glaucocystis oocystiformis Prescott 1944, p. 372
Pl. 108, Fig. 3
Cells solitary (or in colonies ?), broadly elliptic, with nodular
thickenings of the cell wall at the poles; chromatophores numerous,
irregular pads at the periphery of the cell about a central, spherical,
colorless vacuole (?); cells 20-27.3» in diameter, 40-45, long.
This species differs from the others in the shape of cell, the form
of the chromatophores, and in its possession of polar nodules.
Whether the absence of colonial association or the retention of
autospores within the mother cell wall is a constant feature is un-
determined, but in all cases observed, the cells were solitary. In
the developmental stages of G. Nostochinearum as described by
Hieronymus (1892a) the chromatophores show much the same
character as exhibited in G. oocystiformis. I have not found examples
of the latter species showing any form of chromatophore other than
that described.
In a pooled stream, northern Wisconsin.
GLOEOCHAETE Lagerheim 1883, p. 39
Either a single colorless cell or a group of 2-4 such individuals
endophytized by ovate, blue-green protoplasts which form a cup-
shaped body within the host cell; colorless cell spherical, with a
single long and very fine gelatinous hair; plants inclosed in a copious,
homogeneous gelatinous envelope, attached to the walls of fila-
mentous algae.
The genus is similar to Glaucocystis in respect to its symbiotic
composition. The host cell is regarded as a colorless member of the
Tetrasporaceae (Chlorophyta). As in the genus mentioned above,
the colorless host cell is not well understood and merits a critical
study.
Gloeochaete Wittrockiana Lagerheim 1883, p. 39
P]. 108, Fig. 9
Characters as described for the genus; cells 4-8» in diameter,
usually in groups of 4; gelatinous setae about 20 times the diameter
of the cell in length; endophytic cells 1 (or 2 ?), ovoid, forming a
blue-green cup within the host cell.
Attached to filamentous algae in soft water lakes. Mich., Wis.
ORDER CHAMAESIPHONALES
FAMILY CHAMAESIPHONACEAE
Members of this family are solitary, or gregarious and form
families attached as epiphytes or develop as encrusting expansions
[ 475 ]
on stones, shells, and other submerged objects. In many there is a
definite basal-distal differentiation, with the lower part of the cell
narrowed to form an attaching stipe. Although cell division is used
by a few forms, the characteristic method of reproduction is by
endospores (gonidia), i.e., spore-like bodies cut out simultaneously
from the entire protoplast or by successive constrictions at the
anterior end of the cell. There is but a single genus represented in
our collections.
CHAMAESIPHON Braun & Grunow in Rabenhorst 1865, p. 148
A slender, club-shaped (sometimes ovate or pyriform) sheathed
cylinder from a narrow attaching basal portion, growing epiphytic-
ally on other algae or larger aquatics; sheath open at the widened
apex when the cell is mature to permit the escape of 1-celled gon-
idia (endospores) which are cut off successively from the anterior
end of the protoplast; cell contents pale to bright blue-green, homo-
geneous; sheath thin (usually), hyaline or yellowish; plants nearly
always gregarious and often forming extensive patches and showing
all stages of development, the germinating endospores sometimes
forming a layer more than one cell in thickness on the substrate. Of
the many species recognized for this genus, only three are identi-
fiable in-our collections.
Key to the Species
1. Cells long and strongly curved from a stipe-like base C. curvatus
1. Cells short, or elongate, straight, not Sironplyicurved {= =. a SiMe )
2. Entire content of the cell becoming divided to
form many gonidia simultaneously C. confervicola
2. Gonidia cut away from the apex of the protoplast
by ysuceessive” constrictions SU stb he) te wees C. incrustans
Chamaesiphon confervicola A. Braun in Rabenhorst 1865, p. 148
Pl. 108, Fig. 4
Cylindrical to claviform, usually straight, sometimes curved; 1-2
in diameter at the base, 3-9u at the apex; sheath thin, expanded
above; 7% to 34 of the protoplast divided to form endospores, which
are 2-4» in diameter and which may occur in double series or in
groups of 4; plant either solitary or gregarious.
Epiphytic on Cladophora and on submerged mosses and other
aquatic plants. Wis.
Chamaesiphon curvatus Nordstedt 1878, p. 4
Pl. 108, Figs. 5, 6
Several-celled, violet in color, solitary or gregarious, cylindrical,
[ 476 ]
strongly curved and twisted, sometimes club-shaped, with a narrow,
stipe-like base, 3.8—-44 in diameter, 14-65, long.
Growing on Drepanocladus in deep water (5-15 m.). Wis.
Chamaesiphon incrustans Grunow in Rabenhorst 1865, p. 149
Pl. 108, Figs. 7, 8
Cylindrical, gregarious, usually straight (sometimes slightly
curved ), attached to filamentous algae or leaves of aquatic plants;
cells 3-6-(8) in diameter, 10-25, long.
This plant was found growing on mosses and other vegetation
taken from a depth of 30 feet. Mich., Wis.
ORDER HORMOGONALES
In contrast to the Chroococcales and Chamaesiphonales, plants
in this order are filamentous, comprising a “tribe” known as the
Hormogoneae, the other orders making up the “tribe” Coccogoneae.
The plant may consist of a trichome of cells inclosed by a sheath
which is extremely variable in character, or there may be no sheath.
In one suborder, the Homocystineae, there is no differentiation of
the cells within the trichome, and, also, there may or may not be
basal-distal differentiation. In the other suborder, the Heterocy-
stineae, there is a specialization of certain cells in the filament to
form two types of structures which are of taxonomic value. One of
these is the heterocyst, a thick-walled cell, usually somewhat larger
and often different in shape from the vegetative cells. The contents
are ordinarily homogeneous. In many cells, the wall at either pole
is thickened by a plug of mucilage. The heterocyst may be terminal
only, intercalary, or lateral to the trichome. Another special cell
is the spore or gonidium, sometimes termed akinete. This cell is
usually much-enlarged and thick-walled and has an adventitious
reproductive function.
The presence or absence of the heterocyst and spore, the position
of these in the trichome, together with form and size, are all-
important in the recognition of species in this order. Heterocysts
are incapable of cell division, but they assist in vegetative repro-
duction by facilitating fragmentation of the trichome, or by deter-
mining points of proliferation of the trichome through branch for-
mation. In some forms heterocysts are known to function as spores.
Branching of the trichome may be false, or there may be true
branching as a result of cell division in two planes. Reproduction
by fragmentation of the trichome to form hormogonia is common
to nearly all forms, whereas gonidia are employed only in certain
families or genera.
[ 477 ]
Key to the Families
1. Heterocysts lacking; trichomes with or without a sheath; sometimes
with several trichomes within a single sheath ._____ OSCILLATORIACEAE
1. Heterocysts present (rarely absent in some genera which are not
represented in our collections; see Amphithrix) ___________-_______ 2
2. Trichomes exhibiting true branching (branches arising as a
result of cell ‘division’ im) 2iplanes ) 2 = 5 = os ae eee ee eee 8
2. Trichomes exhibiting false branching, or without branches 4
3. Trichomes and lateral branches uniseriate; heterocysts lateral,
ysually at the ends of short branches; sheaths confluent __*NosTOCHOPSACEAE
3. Trichomes and lateral branches multiseriate, or if uniseriate with
thick, firm sheaths which are not confluent...._-_____ _ STIGONEMATACEAE
4. Trichomes decidedly tapering toward the apex, usually from a
basal: lieterocyst,, 202... eR 2 Ate Ee a ee RIVULARIACEAE
4, ‘Tnichomes not) tapering, toward! the apex. =. 5
5. Trichomes with a definite, firm sheath; false branching
frequent) 220» sae eae eee SCYTONEMATACEAE
5. Trichomes without a sheath, or with only a thin one; no
branching a NOSTOCACEAE
SUBORDER HOMOCYSTINEAE
Simple trichomes, without cellular differentiations, with dissepi-
ments (sometimes granular) except in the unicellular genus Spiru-
lina, and usually sheathed. The sliding, spiral, or oscillating move-
ment shown by most members is characteristic of this suborder but
not confined to it. Trichomes reproduce by fission or by fragmenta-
tion (to form hormogonia), sometimes breaking by means of dead
cells (necridia), into sections that then increase in length by fission.
The suborder comprises 1 family.
FAMILY OSCILLATORIACEAE
Key to the Genera
i) Trichomes’ spiralled or sepularly coiled eS 2
1. Trichomes straight, bent, or entangled, but not regularly coiled _________ 4
9), Wate nonnes vate Gl Gavin Lyngbya (in part)
OasTeni hommes wc vvat oui ts ges ti eee ha ere 3
3. Trichomes 1-celled, usually relatively short Spirulina
3. Trichomes much longer, many-celled, with the
dissepiments sometimes indistinct..______________-_=______-________ Arthrospira
4. Trichomes without an evident sheath (though hormogonia may
sometimes showsa, thinesheath)) es ee eee Oscillatoria
ATT GhOmeSnwiAthy alee VAG emits Ske cl knee eae ene 5
5. Sheath containing a single trichome ——-------------—---------------______---- 6
5. Sheath containing several to many trichomes____--____________________- 9
6. Sheaths firm and definite, not sticking to or confluent
with sheaths of other/plants= =) = = 2 ee Lyngbya (in part)
6. Sheaths mucous and sticky, confluent with those
of other plants, often indefinite i
7. Plant mass forming erect tufts from a horizontal expanse,
especially when growing on moist substrates __________ Symploca
7, splantmeasseuoet tOxmnIng erect tures eee ee
8. Trichomes lying parallel, forming planktonic fascicles. Trichodesmium
8. Trichomes entangled, forming mucous, sometimes
thick, layers on a substrate________-_-—-____________- Phormidium
9. Sheaths wide, mucous, soft and sticky; freely branching -.________. 10
9. Sheaths firm and narrow; not freely branching;
trichomes densely compacted and entwined Schizothrix
10. Trichomes loosely arranged, 2-4 in a sheath —______________-_. Hydrocoleum
10. Trichomes densely entangled, many within a sheath. Microcoleus
SPIRULINA Turpin 1827, p. 309
A spirally twisted, unicellular trichome, cylindrical throughout
and not tapering toward the apices (although briefly attenuated in
some species ); spiral loose and lax, or close and tightly coiled ac-
cording to species, the spiral usually very regular; trichomes free-
floating and planktonic or intermingled with other algae in tycho-
plankton, sometimes forming layers on moist soil, especially where
water has subsided.
This genus should be compared with Arthrospira, in which the
trichomes are multicellular. According to the interpretations of some
phycologists the two genera should not be separated. This would
seem to be justifiable when the dissepiments of Arthrospira cannot
be demonstrated and the trichome appears to be unicellular. See
Crow (1927) on the characteristics of these two genera.
Key to the Species
1. Trichomes very tightly coiled.____________-_-_-__----__________- S. subsalsa
1. Trichomes loosely coiled. ®
2. Spirals 10-12—(16) or more V1 CL A Wh a ook a Bs 1 S. princeps
2. Spirals less than 10 Sia (a (Rei uea Meche rateable iia oe os ONE er ane 3
3. Spirals 4-6u wide, very 1 GG Se aa ha I eae a bed oa, oe ee 4
3. Spirals averaging less in width, more tightly coiled ALD
4, Trichamerso ue diameters. S. laxa
An Rrchome.O.— Ose a Giameter ee S. laxissima
5. Spirals 54 wide; trichomes 2 WiC Gi see ee er ae S. Nordstedtii
5. Spirals 2.5-4u wide; trichomes 1.2-1.7u wide, very long. S. major
Spirulina laxa G. M. Smith 1916, p. 481
Pl. 108, Fig. 10
Trichomes loosely spiralled, forming a dark blue-green mass,
2-2.5p in diameter, spiral 4-6. wide; distance between spirals 15-20p
wide; cell contents blue-green.
Tychoplankter. Wis.
[ 479 ]
Spirulina laxissima G. S. West 1907, p. 178
PIO Figs
Trichomes very slender, 0.7-0.8u in diameter, twisted in a very
loose spiral, 4.5-5.31 wide; distance between spirals 17-22»; apex
bluntly rounded.
Euplankter. Mich.
Spirulina major Kuetzing 1843, p. 183
Pl. 108, Fig. 11)
Trichomes loosely spiralled, scattered among other algae, or when
aggregated forming a dark, blue-green mass; trichomes 1.2-1.7p in
diameter; spiral 2.5-41 wide; distance between spirals 2.7-5y.
This is a very active species of great length. It is commonly found
among Oscillatoria species on soil from which water has recently
subsided, or on muddy shores and margins of springs, etc.
Wis.
Spirulina Nordstedtii Gomont 1892a, p. 252
Pl. 108, Fig. 12
Trichomes rather closely and regularly spiralled, 2» in diameter,
spiral 5» wide, distance between spirals 5p; cell contents pale or
bright blue-green.
Plankter; also found on bottom of soft water lakes discolored by
humic acids. Wis.
Spirulina princeps (West & West ) G. S. West 1907, p. 179
Pl. 108, Fig. 13
Trichomes loosely spiralled, either straight or bent, 3-5y in
diameter; spirals 8.8-16 wide; distance between spirals (9.5)—10-
12-(16),; cell contents bright blue-green, homogeneous or slightly
granular.
Among other algae in tychoplankton. Wis.
Spirulina subsalsa Oersted 1842, p. 17
Pl. 108, Fig. 14
Trichomes both closely and loosely spiralled in the same indi-
vidual, 1-2 in diameter; spiral 3-5, wide, often so tightly coiled
that there is no space between the turns.
Tychoplankter. Wis.
ARTHROSPIRA Stizenberger 1852, p. 82
Trichome a long, loosely spiralled, many-celled plant, not at all
or only very briefly tapering toward the apex, which is broadly
[ 480 ]
rounded; sheath wanting; cells quadrate or a little longer than wide,
the dissepiments sometimes granular, sometimes scarcely discernible.
See note under Spirulina (p. 479). These plants may form thin
expansions, but more usually are found intermingled with other
algae, especially Oscillatoria spp.
Key to the Species
TMriGhoOmeseee sa see MTS Ta Te Ce eee A. Gomontiana
TrichomeswG—Gusiiciamecter: 200 ee A. Jenneri
Arthrospira Gomontiana Setchell 1895, p. 430
PI. 108, Fig. 21
Trichomes very loosely spiralled, entangled to form free-floating
flakes, bright blue-green, 2.5-3.2 in diameter; cells 4-5 long, with
the dissepiments often scarcely discernible; cell contents vacuolate
(?); width of spiral 4-6; distance between turns 16-18»; forming
floating patches of much entangled and actively twisting trichomes.
Tychoplankter. Wis.
Arthrospira Jenneri (Kuetz.) Stizenberger 1852, p. 32
Pl. 108, Figs. 22, 23
Trichomes blue-green, scattered or gregarious, loosely coiled, not
tapering toward the apices, 6-8, in diameter; cells quadrate, dis-
sepiments granular, 4-5» long; spiral 10-15, wide, distance between
turns 12-14n.
Intermingled with other Cyanophyta filaments on mud, or in
organic sediment which has collected on submerged plants. Com-
mon. Mich., Wis.
OSCILLATORIA Vaucher 1803, p. 165
Filamentous and elongate, without a sheath (except in hormo-
gonous stages of filament development); straight, or twisted and
entangled; the mature plant showing a polarity with an apical
region, which is often attenuated, the basal end truncate; trichomes
solitary and scattered, or forming expanded plant masses and slimy
layers on submerged objects or on the bottom; microscopically
usually showing an oscillating or gliding movement, especially
active in the anterior portion of the trichome; apical cell smoothly
rounded, or swollen and capitate, sometimes with a distinct sheath-
like membrane, the calyptra; most species having cells much
shorter than their width, with or without constrictions at the cross
[ 481 ]
walls, which sometimes have a row of granules on either side; plants
often living under semi-anaerobic conditions in stagnant water.
In examining species of Oscillatoria care must be used not to
confuse them with Phormidium, a genus in which there are sticky
but sometimes very thin sheaths, which are best seen by stainin
with an aqueous dye or with chlor-zinc-iodide (see Drouet, 1937).
Key to the Species
i. Trichomes':10p.0r more imidiameter= see te es ee, 2
i> Erichomeswlessithany Oj oin. diameters. eet ake eee 8
2° Triehomes :25—80n) intdiameter =.= BO a ae O. princeps
2) Trichomessmallers) 222 /or less in. diameters ie es 3
3. Cells almost colorless, with large, conspicuous
AI COMMON VACUOLES 2h 2s eae Rian pi Nan) A ale eae Does ey O. Bornetii
3. Cells definitely pigmented, without conspicuous alveoli,
although’ sometimes; with pseudovacuoles_= 4 4
4, trichomes) constricted at the cross walls\2- =) ta ey 5
4. Trichomes not constricted at the cross walls === a
5. Trichomes slightly capitate at the apex, with a calyptra_..____ O. sancta
Sawirichomes mat teapitate, withoutia: calyptra == os Cat eh 6
6. Trichomes not tapering at the apex; cells very
short less/thany+$-as long, as broad —-=_ = O. ornata
6. Trichomes tapering at the apex; cells 14
OPMMOre, ass lompras sblOad) aaa tne Y wards alee Bee ee ee Mal O. chalybeu
aA EI MOTHIESe IS tha LG Ib en toe fare io th ee Ae ee eee O. limosa
i} Erichomesshookedsatithe apextcass =e J 8 By deen . eet a, O. curviceps
SabrichomesnO!6—2/0 aiminci amie ter eee eee ee ae aes eae nee 9
8:5 Drichomes (2) =2-2—l0 a. in. diameter = 2 a es wo ee 13
GO} airichomes: 0:6—1e8icim diameter-e- ss es eee e es e 10
9) trichomes: 175-24 in diameters es ee ee ee ene itil
10. Trichomes 0.64 in diameter, 1-1.84 long... O. angustissima
10. Trichomes 0.8—1.3u in diameter, 5—7u long. O. angusta
11. Plants golden-colored, coiled, 2u in diameter____-___-_»___> O. minima
11. Plants blue-green or olive-green, straight, 1.5-1.8—(2)u in diameter. 12
12. Trichomes tapering at the apex, and bent.______________. O. acutissima
12. Trichomes not tapering at the apex, straight O. limnetica
13. Trichomes with cross walls very much thickened, sometimes
nearly equalling the length of the cell cavity_______ O. articulata
13. Trichomes without conspicuously thickened cross walls... 14
14. Plants planktonic and purplish or red,
usually, coloring :the, water 24s. Se se O. rubescens
14. Plants planktonic or not, but not purple
On ed: anid, notacolormmgy the water.) 7 ses. es eee eee 15
IS, Dine nvorines, Qs syn. iim Ghiewnelier 16
Ns, ANmtelvomas NO, tm, ligne 26
16) Apical cellcapitate;;usually with a calyptras = = eee 17
16 4-Apical’ cell wotica pitake, ==. pe. 2 oad es ee 21
17. Trichomes slightly constricted at the cross walls...................... O. amoena
17. Trichomes not constricted at the cross walls _______»___-_______ 8
18. Trichomes tapering for a long distance in the apical region. O. splendida
18. Trichomes not at all or only briefly tapering in the apical region__________ 19
[ 482 }
») Gellsienanulaniat the’ cross walls. 0s... eee eee O. Agardhii
. Cells not granular at the cross walls (rarely granular)..................... 20
. Apicalvee!liiwath a flattened ‘calyptra = Sees Ee O. prolifica
. Apical cell with a cone-shaped calyptra___________________. O. amoena
. ‘richemes tapering in, the apicaliregion 252 2 Set ea 2D
.. Dnichomes mot tapering in the apical regions 23 2 24
» Frichomestsmaughtsthronghout (ste Spee eee O. Agardhii
. Trichomes twisted and bent, or straight in the basal portion and
hooked orreumvediatrthe apex i222 9a: jhe 23
. Trichomes crooked or spirally twisted at the
apers, crossswalismmot pramulars 2 = O. terebriforinis
. Trichomes curved but not hooked or twisted
at the’ apexvierosstwallsupranular 2. 20102 O. granulata
)) \Cellssnotiexanularwaptheteross walls 1.222 ee O. subbrevis
-. Cells, withidistictly. granular cross’ walls 2. = 25
. Cells with rows of granules at the cross walls_____________________ O. tenuis
. Cells with 1 or 2 conspicuous granules at the cross walls O. amphibia
: “Apical cell capitate; usually with a calyptra Dy
ay Apicalicell ot capitate ten es ee ee eee 29
. Trichomes bent or hooked at the apex, forming a plant mass __ O. anguina
. Trichomes scattered in tychoplankton or euplankton, straight —_._ _. 28
. Cells 6—8u in diameter, trichomes usually scattered,
appearing red or purple when in bundles —_-____________- O. rubescens
. Cells 4—6u in diameter, trichomes solitary, or,
when in bundles, appearing blue-green. _..O. Agardhii
Reiinichomies, Sbraiplit 22.0 eee 80
. Trichomes spirally twisted, undulate, or at
leastuhooked orfeurvedatythejapexs = 6a. eh ee 36
. Trichomes constricted (sometimes slightly) at the cross walls............ 34
. Trichomes not constricted at the cross wallls..............0.....0.0.cceccssenee 31
Strichomes mot appeanmp: ted or purple 2 32
. Trichomes appearing red or purple, coloring the water when
abundantly present; solitary or in bundles _________________-_-------- O. rubescens
. Cells 8—9.2—(10)» in diameter (sometimes curved at the apex). O. nigra
MECC) s 4.3.5) => — Oe ine RaNeLer see 83
. Cells granular at the cross walls, with pseudovacuoles —__. O. Agardhii
. Cells not granular at the cross walls, without pseudovacuoles__O. subbrevis
. Trichomes in parallel, free-floating bundles _____________-- O. lacustris
. Trichomes not in parallel, free-floating bundles___________________--____--_--- 85
pe@ellsslome: cy lita Gri Call qs ee a O. Hamelii
; Gells shorter than wide, or about quadrate_ = 2 O. tenuis
Bi@ellsmongacylindrical = See es sie O. Hamelii
. Cells shorter than wide, or slightly longer
tianebroad:, but nearly quadnate see 87
Rerichomes .6—9—( 10) ya: amy chamleten ess = ee 38
, Ihatelrornas leostdeain Gyn tin Clerc 2 40
. Trichomes crooked and much twisted in the apical region ________- O. ornata
. Trichomes regularly curved at the apex (often
shraishior only slightly bent see een ee 39
. Cells granular at the cross walls, very little or
Sometimes Ot at all constricted= === es O. nigra
. Cells not granular at the cross walls, definitely
constrctedsatithe cross walls 25 sees os Pt O. chalybea
40) Trichomesstapering ‘atithe. apex 22). a0. nk See A 4l
40. Drichomes moe tapering: at the apexsss. == eames en een es O. nigra
41. Trichomes crooked and undulate at the apex;
not constricted at ‘the cross.walls = 222) = eee O. terebriformis
41. Trichomes curved at the apex, sometimes straight;
constricted iat the cross.walls: oo! eed O. formosa
Oscillatoria acutissima Kufferath 1914, p. 264
Pl. 109, Fig. 1
Trichomes solitary and scattered, or loosely entangled in the
mucilage of other algae; gradually tapering to the apex, which is
curved or bent slightly. Apical cell acute-conical, with a calyptra.
Cells 1.5-2, in diameter, 114 to 3 times longer than wide; not con-
stricted at the cross walls, which are not granular.
Although I have not seen type specimens of O. acutissima, I have
assigned our plants to this species on the basis of their agreement
with Kufferath’s description.
Tychoplankter; in mucilage of colonial diatoms and egg masses.
Mich., Wis.
Oscillatoria Agardhii Gomont 1892a, p. 205
Pl. 108, Figs. 15, 16
Trichomes interwoven to form a blue-green plant mass; occasion-
ally found floating free; straight throughout their entire length,
briefly tapering at the anterior end, which is usually capitate, but
frequently smooth. Apical cell truncate-conical, with or without a
calyptra. Cells (3.4)-5.5-6, in diameter and not constricted at the
cross walls, which are granular; their length from 1% to approxi-
mately equal their width (sometimes 114 times their width in length).
This species shows a great deal of variation in the morphology
of the apex of the trichome. The straight interwoven filaments, the
cell proportions, and the granular cross walls help to identify it.
Abundant in tychoplankton; generally distributed. Mich., Wis.
Oscillatoria amoena (Kuetz.) Gomont 1892a, p. 225
Pl. 109, Figs. 2-4
Trichomes usually forming a thin, submerged, weft-like, blue-
green mass, or sometimes scattered among other algae; usually
straight but not rigid, slightly tapering toward the apex. Apical
cell broad, capitate, with a cone-shaped calyptra. Cells (2.5)—4-5p
in diameter, 2.5—4.2u long; usually slightly constricted at the cross
walls, which are granular.
In tychoplankton of littoral flora; in springs. Mich., Wis.
[ 484 ]
Oscillatoria amphibia C. A. Agardh 1827, p. 632
Pl. 109, Fig. 6
Trichomes straight or curved and interwoven to form a thin,
blue-green plant mass on submerged objects or in moist aerial habi-
tats; not tapering toward the apex. Apical cell broadly rounded,
smooth, with a convex outer membrane. Cells (1.5)—2-2.8-(4), in
diameter, 2-4 times their diameter in length (4-8); not constricted
at the cross walls, which have a single large granule on either side,
a series of paired granules showing throughout the length of the
trichome.
In shallow water of lakes, ponds, and swamps; on submerged
objects. Mich., Wis.
Oscillatoria anguina (Bory ) Gomont 1892a, p. 214
Pl. 108, Fig. 24
Trichomes entangled and interwoven to form a dark green plant
mass on submerged objects, or intermingled among other algae;
straight for most of their length but bent and sometimes twisted in
the apical region, slightly tapering toward the apex. Apical cell
slightly narrowed and capitate, with a thickened outer membrane.
Cells 7-8 in diameter, short, as little as 4% of their diameter in
length; not constricted at the cross walls, which are granular. Swol-
len refringent cells common throughout the length of the trichome.
Forming films on bottom in shallow water. Wis.
Oscillatoria angusta Koppe 1924, p. 641
Pl. 109) Fig, if
Trichomes loosely entangled to form a thin plant mass, or solitary;
not tapering toward the apex; apical cell bluntly rounded, without
a calyptra and not capitate; cells (0.8)-1.1-1.3y in diameter, (5)—
7-8-(10), long, not constricted at the cross walls; contents nearly
colorless, without pseudovacuoles or conspicuous granules.
Entangled and intermingled with other species of Oscillatoria
and miscellaneous blue-green algae, forming a slimy layer in shallow
water. Wis.
Oscillatoria angustissima West & West 1897, p. 300
PI. 109, Fig. 5
Trichomes much entangled to form a thin, light blue-green plant
mass, not tapering toward the apices; apical cell bluntly rounded,
not capitate and without a calyptra; cells 0.6-1.0y in diameter, 1144-
3 times their diameter in length; not constricted at the cross walls,
[ 485 ]
which are scarcely discernible, especially in the anterior end of
the trichome; cell contents almost colorless.
This is the smallest species of Oscillatoria appearing in our col-
lections. It is easily mistaken for a filamentous bacterium because
of its size and pale color. In mass, however, it clearly shows its
blue-green algal identity. Not infrequently this species is found en-
tangled in the mucilage of colonial Cyanophyta.
Tychoplanktonic and euplanktonic. Mich., Wis.
Oscillatoria articulata Gardner 1927, p. 34
[Oscillatoria Grunowiana var. articulata (Gard. ) Drouet]
Pl. 107, Fig. 22
Trichomes entangled, flexuous, forming a thin blue-green plant
mass, or scattered among other algae, not tapering to the apices;
apical cell rounded, not capitate and without a calyptra, but with
a thickened outer membrane; cells 2.8-3.2 in diameter, quadrate
or 44-14 as long as broad, not constricted at the cross walls, which
are conspicuously thickened, sometimes as much as the length of
the cell cavity.
Mich.
Oscillatoria Bornetii Zukal 1894, p. 260
Pl. 108, Figs. 19, 20
Trichomes forming a slimy, expanded plant mass, or intermingled
among other algae; more or less straight but often bent or slightly
sigmoid in the apical region, not tapering toward the apex. Apical
cell smoothly rounded, not capitate, and without a calyptra. Cells
(10)-12-16, in diameter, 3.744 long; not constricted at the cross
walls; cell contents pale, almost colorless, with large quadrangular
alveolations or vacuoles.
Tychoplankter; in lakes and slowly flowing water. Wis.
Oscillatoria chalybea Mertens in Jiirgens 1822, Dec. 18, No. 4
Pl. 109, Figs. 8, 9
Trichomes aggregated to form a dark blue-green plant mass;
straight for a portion of their length but much entangled and some-
times spirally twisted, gradually tapering toward the apex. Apical
cell conical, with a smooth, unthickened outer membrane. Cells
(6)-8-12-(13) in diameter, 4-6.8, long; slightly constricted at
the cross walls, which are not granular.
Tychoplankter. Mich., Wis.
[ 486 ]
Oscillatoria curviceps C. A. Agardh 1824, p. 68
Pl. 108, Figs. 17, 18
Trichomes forming an expanded blue-green plant mass; straight
for at least a portion of their length, twisted and much entangled,
scarcely tapering to the apex. Apical cell broadly rounded, not
capitate, without a calyptra. Cells 10-14-(17), in diameter, 3-5y
long; not constricted at the cross walls, which may be granulate.
Forming floating clots; tychoplanktonic. Mich., Wis.
Oscillatoria formosa Bory 1827, p. 474
Pl. 109, Figs. 10, 11
Trichomes aggregated to form a dark blue-green plant mass;
straight and rather firm, curved and slightly tapering toward the
apex. Apical cell conical, not capitate, without a calyptra. Cells 4-6
in diameter, 2.5—5, long; constricted at the cross walls, which
are granular.
Rather common on wet soil at margins of lakes, and about
swamps; tychoplanktonic in shallow water of ponds. Mich., Wis.
Oscillatoria granulata Gardner 1927, p. 37
Pl. 109, Figs. 12, 13
Trichomes aggregated to form an expanded plant mass; straight
or somewhat curved, especially at the apex, which is slightly atten-
uated. Apical cell not capitate and without a calyptra. Cells 3-5
in diameter, 14-114 times their diameter in length; not constricted
at the cross walls, which are distinctly granular.
Occurring as small, slimy flakes, or scattered among other algae.
Wis.
Oscillatoria Hamelii Frémy 1930, p. 218
Pl. 109, Fig. 14
Trichomes solitary among other algae, or sparsely aggregated to
form blue-green masses; straight or undulate, not attenuated at the
apices. Apical cell truncately conical, without a calyptra. Cells
7.2-8.5 in diameter, 114-2 times the diameter in length; distinctly
constricted at the cross walls, which are not granular.
This plant is assigned here on the basis of its agreement with
Frémy’s description. The type habitat of O. Hamelii is in Africa,
but the universal distribution of many species of the genus makes
its appearance in North America not unusual.
Forming a film on dead leaves in a stream. Wis.
[ 487 ]
POscillatoria lacustris (Kleb.) Geitler 1925a, p. 362
[Trichodesmium lacustre Klebahn 1895, p. 13]
Pl. 109, Fig. 15
Trichomes straight, lying parallel in free-floating, flake-like bun-
dles or fascicles, not tapering at the apices; apical cell broadly
rounded, without a calyptra; cells compressed globose or barrel-
shaped, sometimes semiquadrate, or a little longer or shorter than
wide, 5-7» in diameter, 3-7» long; cell contents with many pseudo-
vacuoles.
The specimens assigned here are enigmatic. The bundles of
trichomes strongly suggest Trichodesmium because of their arrange-
ment and lack of heterocysts. They are not like Trichodesmium
lacustre Klebahn, however, in respect to the morphology of the
apical cell which in that species is long and attenuate, but which
in our specimens is short and rotund. The suggestion has been made
that the plant found in our collections is a juvenile form of Aphani-
zomenon, which would appear reasonable because of the similarity
in respect to trichome arrangement, cell shape, and cytology. As I
have pointed out elsewhere (1942, p. 665), however, the occurrence
of these bundles of trichomes in what certainly appears to be a
mature condition and without any suggestion of nostochaceous
characters (heterocysts, gonidia), precludes such a disposition.
Geitler has assigned Klebahn’s species to Oscillatoria and relegates
the Wisconsin plant previously reported by Smith (1920) to Aphani-
zomenon. There is scarcely enough evidence at present to justify
giving a new name to the Wisconsin plant, but it is possible that
subsequent study will establish it as a new fresh-water species of
Trichodesmium.
Plankter; in hard or semi-hard water, especially eutrophic, lakes.
Wis.
Oscillatoria limnetica Lemmermann 1900, Ber. d. Deutsch.
Bot. Ges., 18, p. 310
Pl. 109, Fig. 16
Trichomes solitary and planktonic or intermingled with other
algae in littoral waters; straight or flexuous, not tapering toward the
apex. Apical cell bluntly rounded and without a calyptra. Cells
1.5-1.8 in diameter, 314 times the diameter in length; not con-
stricted at the cross walls, which are scarcely visible and are not
marked by granules.
In shallow water of swamps and bogs; among submerged aquatics.
Wis.
[ 488 ]
Oscillatoria limosa (Roth) C. A. Agardh 1812, p. 35
PIZLOS) Pig7
Trichomes usually forming a very dark blue-green or brownish
plant mass attached to submerged objects or forming films on sandy
bottoms, although rarely solitary or loosely entangled among fila-
mentous algae; straight, tapering little or not at all toward the
apex. Apical cell rotund, the outer membrane thickened but without
a definite calyptra. Cells 12-18—(20) in diameter, 3.7-5y long, not
constricted at the cross walls, which are usually granular. Trichomes
not infrequently inclosed in a hormogonous sheath.
Common in stagnant water of ditches and small ponds; tycho-
planktonic in lakes. Mich., Wis.
Oscillatoria minima Gicklhorn 1921, p. 4
Pl. 107, Fig. 24
Trichomes somewhat coiled and spirally twisted, golden-colored,
inclosed in a delicate mucilaginous sheath, not tapering toward the
apex; apical cell not capitate and without a calyptra; cells 2 in
diameter, 5-6, long.
Mich.
Oscillatoria nigra Vaucher 1803, p. 192
Pl. 109, Fig. 18
Trichomes aggregated to form a thick, mucilaginous blackish-
green plant mass on submerged objects, becoming free-floating;
straight or slightly twisted and entangled, slightly tapering toward
the apex and curved (or straight). Apical cell rotund, not capitate
and without a calyptra. Cells 8—10y in diameter, 3.7—4.5, long;
slightly constricted at the cross walls, which are sometimes gran-
ular; cell contents dark olive-green.
Common in the shallow water of many lakes and ponds. Mich.,
Wis.
Oscillatoria ornata Kuetzing 1845-1849, p. 30
Trichomes forming a dark, blue-green plant mass; spirally twisted
at the end, not at all or scarcely tapering toward the apex. Apical
cell broadly rounded, not capitate and without a calyptra. Cells
9-11p in diameter, short, 14-14 times as long as broad (2-5p long),
constricted at cross walls which are granular.
Mich.
Oscillatoria princeps Vaucher 1803, p. 190
PE L110; Fig. 1
Trichomes solitary or loosely entangled to form small floating
plant masses, which are black-green in color; individual plants
[ 489 ]
visible to the unaided eye; trichomes very slightly and briefly taper-
ing at the apex. Apical cell usually not capitate, sometimes very
slightly so, the outer membrane broadly convex and smooth. Cells
32-55—(80)» in diameter, 4-8.71 long; not constricted at the cross
walls, which are not granular; cell contents densely granular.
Common in tychoplankton of a variety of lakes and small ponds;
in marshes. Mich., Wis.
Oscillatoria prolifica (Grev.) Gomont 1892a, p. 205
Pl. 110, Figs. 2, 3
Trichomes aggregated to form a floating, purple-black expanded
mass; straight, but flexible, slightly tapering toward the apex. Apical
cell capitate, with a broadly flattened calyptra. Cells 2.5-5, in
diameter, 4-6, long, without constrictions at the cross walls, which
are sometimes granular; cell contents densely granular. Plant
described as becoming lilac-colored upon drying.
Tychoplanktonic and euplanktonic. Mich., Wis.
Oscillatoria rubescens De Candolle 1825, Mém. Soc. Phys.
Nat. Geneve, 2, p. 29
Pl. 107, Fig. 21
Trichomes solitary or forming small fascicles, appearing red or
purple in the plankton; very slightly if at all tapering toward the
apex. Apical cell often capitate, with a calyptra, but (in our speci-
mens ) as often broadly rounded and smooth. Cells 6-8 in diameter,
2-4» long; not constricted at the cross walls, which are usually
granular; cell contents with pseudovacuoles.
Our specimens definitely appear to belong to this species, but
the lack of capitate apical cells in most plants observed, and the
non-tapering trichomes are in disagreement with the original de-
scription.
Euplanktonic and tychoplanktonic. In hard water lakes of south-
ern Michigan; forming blooms during late winter immediately after
the disappearance of ice.
Oscillatoria sancta (Kuetz.) Gomont 1892a, p. 209
Pl. 110, Fig. 4
Trichomes aggregated to form a dark gray-green plant mass (in
our collections), usually on submerged vegetation; straight, not at
all or scarcely tapering toward the apex. Apical cell somewhat
capitate, with a calyptra, and with a much thickened outer mem-
brane. Cells 11—13—(20)» in diameter, 4—5y long; slightly con-
stricted at the cross walls, which are conspicuously granular; cell
contents coarsely granular, olive- or gray-green in color.
On submerged aquatics. Mich., Wis.
[ 490 ]
Oscillatoria sancta var. aequinoctialis Kuetzing 1845-1549, p. 30
A questionable variety, with a diameter in the upper limits of the
species range (14~-20,).
Mich.
Oscillatoria splendida Greville 1824, p. 305
Pl. 110, Figs. 5-7
Trichomes solitary and scattered, rarely aggregated in small,
flake-like masses; straight or curved, tapering for a long distance
to a fine hair at the apex. Apical cell conical and capitate. Cells
2.2-2.8 in diameter, 7.2-9» long, not constricted at the cross walls;
cell contents finely granular or homogeneous, pale blue-green.
Common in a variety of lakes with a high pH; generally distrib-
uted. Mich., Wis.
Oscillatoria subbrevis Schmidle 1901b, p. 243
Pl. 107, Fig. 23
Filaments solitary, not occurring in a plant mass; straight and not
tapering toward the apices. Apical cell rounded, not capitate and
without a calyptra. Cells short, 5-6 in diameter, 1-2 long, with
frequent necridia in evidence; cross walls not granular; cell contents
pale gray-green.
Mich.
Oscillatoria tenuis C. A. Agardh 1813, Algarum Decades, p. 25
Pl. 110, Figs. 8, 9, 14
Trichomes aggregated to form a blue-green mass, sometimes be-
coming scattered and appearing singly among other algae. Straight
or slightly flexuous, especially at the anterior end, which does not
taper; hormogonous sheath frequently present. Apical cell convex,
smooth, and not capitate; outer membrane sometimes slightly thick-
ened. Cells (4)-5-8-(10)» in diameter, 2.5-3.2-(5)y long; con-
stricted at the cross walls (sometimes only slightly so), which
are granular.
Generally distributed and very common in tychoplankton of a
variety of lakes and ponds; in swamps and roadside ditches. Mich.,
Wis.
Oscillatoria tenuis var. natans Gomont 1892a, p. 221
Pl. 110, Figs. 10, 11
A variety differing from the typical by having stouter trichomes
(in our specimens), which are 7.4-10, in diameter; cells 3.44.6
long; apical cell truncately rounded.
[ 491 ]
Forming a blue-green algal film on the bottom; tychoplanktonic.
Wis.
Oscillatoria tenuis var. tergestina (Kuetz.) Rabenhorst 1865, p. 102
PH WMO Wigs i213
A variety differing from the typical by its smaller proportions,
5.56 in diameter; apical cell convex or cone-shaped.
Drouet (1938, p. 269) states that both this variety and var. natans
may be found in the same collection, suggesting that the differences
in size hardly justify the use of two varietal names. Gomont in his
monograph (1892, p. 221) recognizes the variety.
Euplanktonic and tychoplanktonic. Wis.
Oscillatoria terebriformis C. A. Agardh 1827, p. 634
Pl. 107, Figs. 25, 26
Trichomes forming a plant mass, dark steel-blue in color; spirally
twisted, especially at the apex, slightly tapering in the apical region.
Apical cell round or pointed, not capitate, and without a calyptra.
Cells 4-6.5y in diameter, 2.5-6 long; not constricted at the cross
walls.
Mich.
PHORMIDIUM Kuetzing 1843, p. 190
Plant mass consisting of simple, unbranched filaments within
agglutinated and diffluent sheaths which form mucilaginous layers
or penicillate tufts (streaming in flowing water). Trichomes cylin-
drical throughout, except for a slight and brief tapering in the apical
region; either parallel or entwined. Apical cell conical, blunt-
pointed or capitate, with or without a calyptra. Individual sheaths
usually indistinct and difficult of demonstration, although the
diffluent sheaths of the plant mass are clearly in evidence. Cells
shorter than wide, or quadrate; constricted at the cross walls in
some species.
Under certain conditions of preservation the sheath structure of
species in this genus may become so difficult of demonstration that
it is possible to confuse them with some forms of Oscillatoria. It is
the sheath which fundamentally separates the two genera. In the
field and in macroscopic appearance they may be differentiated
usually on the basis of the compact, felt-like layer constructed by
Phormidium. Whereas masses of some species of Oscillatoria may
form somewhat similar mats, the trichomes dissociate easily when
the collection is made. In Phormidium, the mat when present is
compact and does not dissociate.
[ 492 ]
Key to the Species
1. Trichomes short, living within the mucilage
of other Cyanophyta (e.g. Microcystis )...........::c1eciee P. mucicola
1. Trichomes long, forming plant masses, not
living within the mucilage of other algae...................0:: eee 2
2. Trichomes with constrictions at the cross walls ..............0..:::ccees 3
2. Trichomes without constrictions at the cross walls.........0....00.0ccs 6
3° Trichomes capitate at the apex. cccgceccceecs tenn see cet ee coc eeeeencneteganeenss P. lucidum
Sh Trichomes: mae Gapitate sie tee ee eee ence oon cece seascape oanestaaaee 4
4, Apical cell decidedly tapering and elongate 20.0.0... P. tenue
4. Apical cell not elongate, not or slightly tapering ............0.- es 5
5. Cells 2.5m in diameter, 2—4u long ...............cccceeeee P. minnesotense
B@ells 426) in wiameters 1220 by WOM oto as. fa.se sens ewe secre: P. ambiguum
6. Trichomes decidedly twisted or hooked at the apex.............. P. uncinatum
6. Trichomes not twisted, straight or slightly curved at the apex............ 7
@. Apical “cell (capitate oc: ocoe cece ccs saceceterre erence aeons tecncbeveswerecracnenne edenes tanec 8
7. Apical’ cell not Capitate 3 pce seek tape ae anata esate ona 11
8. Trichomes with a conical, sharply pointed calyptra........ P. Setchellianum
8. Trichomes with a broadly rounded or convex calyptra.................0-+. 9
Gili hones? est reli gitar ees eee ese eee ac ote teed aera =ciaia 10
Ge kmchomies scurved. clexmwous ) eect terete ace ret rer eee: P. autumnale
10: Gells longer ‘tham wide ji )-0:2.3:5-20e 2 beeaecacon cece O00 eer veges neces P. favosum
1OksGellseshorter thane pwidese., 2 eres et neat new esterase: P. subfuscum
1 ‘Plant mass incrusted wath lime (2.222. 4-.c...5-6: 222 -casecnnsoee ee P. incrustatum
ldewPlant- mass not ameristed) with ‘Mintel 2) oe. cect ce secneccenceersene see re os a 12
PIG rossi walls cerani lane oe. Bee -tosc ten. ccna ote pone ences ed P. inundatum
Se ransecyralll's is carob rene aN a sce eh geet veneers are sese send gases as 13
13. Trichomes curved; cells 3—4.5u in diameter, 3.4—8» long ....... P. Corium
13. Trichomes straight; cells 4.5—12u in diameter,
PNET VPP (yas a el nea eee Pd ne cee Pence nome Pc ree P. Retzii
Phormidium ambiguum Gomont 1892a, _p. 178
PL Big
Filaments forming a blue-green, mucilaginous layer; straight or
gracefully curved, either parallel or somewhat entwined; individual
sheaths usually distinct and lamellate but becoming confluent with
the mucilage of the plant mass; trichomes curved or rarely straight
at the apices, which are not tapering; apical cell broadly rounded,
not capitate, but with a thickened outer membrane, which may
give a slightly pointed appearance; cells short, disc-like constricted
at the cross walls, 4-6 in diameter, 1.2—2.7 long; cell contents
finely granular.
Among other algae and floating free in tychoplankton. Wis.
Phormidium autumnale (C. A. Ag.) Gomont 1893, p. 207
Pl. 107, Figs. 19, 20
Plant mass forming a broadly expanded, dark-green, mucilaginous
layer; filaments much entangled but may be either straight or
curved and flexuous; sheaths at first distinct, becoming diffluent
[ 493 ]
and confluent with the mucilage of the plant mass; apex slightly
tapering, either straight or somewhat curved and capitate, with a
calyptra; cell contents blue-green; cells 4-7 in diameter, 2-5» long,
not constricted at the cross walls, which are granular.
Mich.
Phormidium Corium (C. A. Ag.) Gomont 1890, p. 355
Filaments compactly intertwined and entangled to form a soft
but tough membranous layer, dark bluish-green to black; sheaths
thin and becoming confluent with the mucilage of the plant mass,
trichomes curved (or straight) and slightly tapering at the apex,
but not capitate and without a calyptra; cells 3-4.5, in diameter,
3.48 long, not constricted at the cross walls; cell contents granular.
Mich.
Phormidium favosum (Bory ) Gomont 1892a, p. 180
Pl. 111, Fig. 2
Filaments forming a dark green expanded, thin or thick plant
mass; individual sheaths not clearly evident; trichomes straight or
flexuous and sometimes coiled in the distal region which tapers
slightly; apical cell capitate, with a conical or hemispherical calyp-
tra; cells 4.5-9, in diameter, 3-7 long, not constricted at the cross
walls but with a double row of granules at the partitions; cell con-
tents blue-green.
In trough, at Osceola, Wisconsin.
Phormidium incrustatum (Naeg.) Gomont in Bornet &
Flahault 1889, p. CLIV
Filaments forming a dark red or violet stratum, encrusted with
lime. Trichomes parallel, or curved and entangled in thin mucous
sheaths; straight at the apex and tapering slightly, not capitate.
Apical cell obtuse-conical. Cells quadrate or slightly longer than
wide; not constricted at the cross walls, which are sometimes gran-
ular; 4-5p in diameter, 3.5-5.2 long.
In a stream at Osceola, Wisconsin.
Phormidium inundatum Kuetzing 1849, p. 251
Pl. 111, Fig. 3; Pl. 107, Fig. 15
Filaments forming a blue-green, gelatinous, membranous expan-
sion; individual sheaths scarcely discernible, diffluent. Trichome
straight and parallel, tapering at the apices to form a conical apical
cell, which is not capitate. Cells quadrate or short-cylindric, 3-5
[ 494 ]
in diameter, 4-8 long; not constricted at the cross walls, which
are granular; cell contents granular, especially at the cross walls.
Tychoplanktonic; on submerged vegetation. Wis.
Phormidium lucidum (C. A. Ag.) Kuetzing 1843, p. 194
Filaments forming thick, firm mats which are dark green above
but colorless within. Trichomes somewhat parallel, either curved or
(at least at the ends) straight, and slightly tapering, sometimes
ending in a point but with the apical cell capitate; calyptra broadly
rounded; sheath diffuent and not colored by chlor-zinc-iodide
reagent. Cells very short, 7-8» in diameter, 2-2.5p long; slightly
constricted at the cross walls, which are granular.
Mich.
Phormidium minnesotense (Tilden) Drouet 1942, p. 136
Filaments forming a blue-green, thin expanse; individual sheaths
indistinct, confluent with the mucilage of the plant mass; trichomes
straight or slightly curved, parallel or somewhat entangled, not
tapering at the distal end; apical cell broadly rounded, not capitate,
and without a calyptra; cells short-cylindric, 2.5p in diameter, 2-4
long, constricted at the cross walls.
Tychoplankter. Wis.
Phormidium mucicola Naumann & Huber-Pestalozzi in
Huber-Pestalozzi & Naumann 1929, pp. 67, 68
Pl. 111, Figs. 4,5
Filaments short, clustered or scattered in the mucilage of other
blue-green algae (Microcystis). Sheaths thin, inconspicuous, difflu-
ent. Trichomes parallel or scattered; up to 50, long; not tapering
at the apices, which are broadly rounded or conical. Cells quadrate
to short-cylindric, 1.3-2» in diameter, 1.8-3p long; constricted at
the cross walls, often separated from one another; cell contents
pale blue-green.
This species is a frequent inhabiter of colonies of Microcystis
aeruginosa, in which there may be far fewer Microcystis cells than
Phormidium filaments.
Rather common in hard water; euplanktonic. Mich., Wis.
Phormidium Retzii (C. A. Ag.) Gomont 1892a, p. 175
PIM Hig.6
Filaments forming thin, dark blue-green skeins or tufts on sub-
merged aquatics, or floating free; sheaths thin and inconspicuous,
diffuent; trichomes straight, parallel, not tapering at the apices, or
[ 495 ]
very slightly so; apical cell truncate, with the outer membrane
thickened; cells quadrate, or longer (sometimes shorter) than wide,
4.5-12u in diameter, 4.8» long, usually not constricted at the cross
walls except in the distal end of the trichome; cell contents granular.
On submerged aquatics or floating in small tufts in hard water
lakes; forming thick, streaming tufts in flowing water; forming a
membrane on casing of a spring. Mich., Wis.
Phormidium Setchellianum Gomont 1892a, p: 156
Filaments forming a thin, weft-like, dark purple layer; sheaths
thin and generally confluent with the mucilage of the plant mass;
trichomes curved or straight, often hooked at the apex, which is
not tapered, or but very slightly so; apical cell capitate with a coni-
cal calyptra; cells 44.8 in diameter, 3-6» long, constricted at the
cross walls; cell contents purplish.
On muddy shores. Mich.
Phormidium subfuscum Kuetzing 1848, p. 195
Pl. 107, Fig. 16
Filaments forming a widely expanded, thin and Jamellate plant
mass, dark green (or olive) in color. Trichomes straight, agglutinated
and more or less parallel, relatively short; straight at the apex and
briefly tapered; sheath becoming diffluent with the mucilage of
the plant mass. Apical cell capitate, with a broadly rounded calyp-
tra. Cells 5.5—11p in diameter, 2—4y long, granular, not constricted
at the cross walls. Cell contents sometimes granular and_ blue-
green in color.
On log near shoreline of lake, Mich.
Phormidium tenue (Menegh.) Gomont 1892a, p. 169
PRAT, Figs 7
Filaments forming a blue-green, membranous expanse; sheaths
diffuent, mucilaginous and indistinct; trichomes straight except at
apices, where they are bent and attenuated; apical cell conical,
smooth, neither capitate nor furnished with a calyptra; cells 1.2-8
in diameter, 2.5-5y long, constricted at the cross walls, which are
not granulate; cell contents homogeneous.
Common, forming thin films on submerged aquatics and inter-
mingled with decaying vegetation in shallow water. Mich., Wis.
Phormidium uncinatum (C. A. Ag.) Gomont 1890, p. 355
Pl. 107, Fig. 18
Filaments forming an expanded, thin but firm plant mass, either
[ 496 ]
floating or adherent to a substrate, dark green or brownish; tri-
chomes straight or curved, briefly tapered at the apex, which is
hooked or spiralled; sheaths sticky, distinct finally but becoming
confluent with the mucilage of the plant mass; apical cell capitate,
with a rotund or conical calyptra; cells not constricted, 6—9 in
diameter, 2—6p long, granular at the cross walls; cell contents blue-
green.
On mud near stream, Mich.
LYNGBYA Agardh 1824, p. XXV
Filamentous, composed of a uniseriate, unbranched trichome of
cells inclosed by a non-gelatinous, more or less firm sheath; plank-
tonic and solitary, or aggregated, forming entangled masses on
substrates or intermingled among other algae; some species spirally
coiled; trichomes mostly cylindrical throughout and tapering very
slightly, if at all, toward the apices, which are usually not capitate.
In favorable habitats some of the planktonic species may become
superabundant, but unlike Aphanizomenon flos-aquae and Micro-
cystis aeruginosa, the plants remain distributed throughout the
water and do not form sticky masses and floating scums; hence they
seldom figure in water bloom disturbances.
Key to the Species
1. Filaments spirally coiled or twisted, sometimes
entwinedsabout other “algae. 5st t = eee ee ee a ee 2
1. Filaments straight, curved, or entangled,
buiamotadelinitely coiled)... 525 2550s ee =
2. Filaments wound about and creeping over
Otnenmlamentous algae. 2 Se 2 Sa ee L. epiphytica
2: Filaments not entwined about other algae 3
3. Trichomes very loosely spiralled, or merely
Wwaviye(Obtenystraip hips: 2 et L. spirulinoides
3.) brichomes closely coiled and: twisted == 52 4
4, Trichomes irregularly twisted and coiled _____________-_____- L. Lagerheimia
4°vtrichomes recularly*spiralled&s 222233205 ye L. contorta
Sea bilaments: 0-59 ini diametcrees oS 6
i, liibmaeaes Teas doch OO) tim Gleronelyere 8
6. Filaments euplanktonic, 20-24, in diameter;
sheath Oio—40 thick: solitary) ss ee Se L. Birgei
6. Filaments tychoplanktonic, intermingled with
Otheralaae: ox tormming a plant mass a
7. Filaments 44—58u in diameter; sheaths up to
5u thick; intermingled with other algae__________________-_-------------- L. latissima
7. Filaments 8—24—(28)u in diameter; sheaths thinner; usually
forming) entangled plant) masses= == == a L. aestuarii
S-ePlants cuplanktonic amd solitary 9
8. Plants epiphytic, adherent and forming plant
masses, or entangled among other algae, tychoplanktonic__.___. 12
[ 497 ]
A FGil armemtSpelale NG pepsin Gli arn © ee eee 10
Hilamemntssorria lle retook oP eae ee I Se Mal
. Trichomes 11-13. in diameter,
usually with, pseudovacuoles =)" 2) Ss a L. Hieronymusii
. Trichomes 14—16u in diameter, without pseudovacuoles L. spirulinoides
; Plant mass*purpleyor purple-red= 2 ee L. purpurea
Plants; solitany, iblue-gteen= == == see eee L. limnetica
//Plantamass) purplish or purple-ted= = ee L. purpurea
‘yPlantmass (eray- 01 bltie-Sreem se eee ee 13
. Filaments small, 14—(rarely 5) in diameter________-__----------------------- 14
) Hilaments) 5-202 nuedianicter = ee 16
. Plants forming a layer of much entangled
filaments, (‘See also EZ: Diguert below) = === L. versicolor
. Plants not forming a definite mass or layer;
solitary or gregarious; epiphytic ________________ 15
. Filaments 1.2—2u in diameter, lying prostrate along the host plant
for much of their length and then curved away to form a free
apical portion; cells usually quadrate or shorter than wide __ L. Nordgaardii
. Filaments 2-3.2u in diameter, arising directly from the host plant,
with little of their length prostrate; cells usually longer than wide;
filaments sometimes forming a plant mass, usually on Rhizoclonium
or Cladophora, or other filamentous algae which do not have a
mucilaginous outer wall layer L. Diguetii
Filaments sl0-20u inidiameter =e ee ee eee ff
Bilamentseo=) Owsine aiameten= oss eee owe en ee eee 18
. Filaments mostly straight; apical cell with a thickened outer |
membrane; trichomes 11-17 in diameter ___--____-_----.----------- L. major
. Filaments much entangled; apical cell without a thickened outer
membrane; trichomes variable, (8)—10-20—(24) in diameter _ L. aestuarii
. Filaments lying parallel, forming tufts —.__-____________ L. Taylorii
. Filaments not lying parallel and not forming Gefmitestutts se 19
_ Trichomes small, 2.8-3.4u in diameter; filaments up to 5u wide;
sheaths thick (2u); cells usually distinctly longer than wide —. L. versicolor
. Trichomes larger; cells shorter, 1.7—3.34 long. a ee 20
. Filaments 6—10u in diameter; apical cell
rotund: sheaths, thick 00) = lees he L. Martensiana
. Filaments 4—6u in diameter; apical cell conical, usually capitate,
with a thickened outer membrane__.....---------------------- Ih aerugineo-caerulea
Lyngbya aerugineo-caerulea (Kuetz.) Gomont 1892a, p. 146
Pl Fries; 10pm
Plants aggregated, forming masses of curved and loosely entangled
filaments among other algae, or expansions on submerged substrates
(solitary filaments frequently found scattered among other plants);
filaments (4)-6-(7.5)» in diameter; trichomes 4-7» in diameter;
cells varying in length from a little less to longer than the width,
2.7-7.8» long, not at all or but very little constricted at the cross
walls; apices of trichomes straight, with cone-shaped or slightly
capitate terminal cells. Sheaths firm, thin, sometimes with regularly
[ 498 ]
spaced bands of roughenings; colorless; extending far beyond the
apices of the trichomes.
In a variety of lakes, both acid and hard water; in Sphagnum bogs.
Mich., Wis.
Lyngbya aestuarii ( Mert.) Liebmann 1841, p. 492
Pl. TUS igs
Plants aggregated, entangled, forming extensive layers on sub-
merged substrates, or upon moist earth and stones; sometimes be-
coming free-floating. Filaments varying greatly in diameter, 10-26,
wide. Trichomes 8-20-(28), in diameter, tapering a little at the
apices, which vary in shape, conical, truncate, or somewhat capitate.
Cells 2.5-5 in length, not constricted at the cross walls. Sheaths
firm, becoming thickened, lamellose, and discolored with age.
This species sometimes forms very thick, felt-like layers, yellow-
gray or olive-green in color, the color ordinarily masked by accumu-
lated silt and debris.
On stones and moist earth. Mich., Wis.
Lyngbya Birgei G. M. Smith 1916, p. 482
PL 1, Fig: 9
Plants solitary, planktonic, scattered among water bloom organ-
isms; filaments straight, (18)-24-(25), in diameter, with many
hormogonia when aged; sheaths thick and firm, not lamellated, ex-
tending far beyond the apices of the trichomes, which are broadly
rounded; trichome 20-24, in diameter, not constricted at the cross
walls; cells very short and disciform, 3-7,» long.
This species is frequently a prominent element in the composition
of water blooms which develop in lakes with a pH of 7.4-9.0. It is
almost invariably associated with Microcystis aeruginosa, Aphanizo-
menon flos-aquae, Anabaena flos-aquae, Stephanodiscus spp. and
Melosira spp. In fact, its association with these species in eutrophic
waters is so constant that during the months of July and August,
at least, the relative abundance of Lyngbya Birgei G. M. Smith can
be used as an approximate index of alkalinity. Although abundant
in hard water lakes it does not play an important role in the water
bloom disturbances of which Aphanizomenon and Microcystis are
capable, because of its failure to form clots and floating masses.
Common in the euplankton of many hard and semi-hard water
lakes. Mich., Wis.
[ 499 ]
Lyngbya contorta Lemmermann 1898, p. 202
Pl M2s Higa
Plants solitary and planktonic, spirally twisted or coiled (rarely
straight); trichomes not tapering at their apices and withaut con-
strictions at the cross walls; cells 1.5-21 in diameter, 3.5-5.6y long;
sheaths thin but firm.
This plant sometimes becomes dominant in the plankton of a
hard water lake and so abundant as to color the water a brownish-
green or a rusty-gray. In some small Iowa lakes it has been found
in almost pure growth with scarcely any other phytoplanktonic spe-
cies present. The dispersed habit of the plant and its failure to
agglutinate account for its inability to produce the unbalanced con-
ditions produced by other blue-green plankters.
Eu- and tychoplanktonic. Wis.
Lyngbya Diguetii Gomont in Hariot 1895, p. 169
Pl. 112, Fig. 8
Plants solitary or entangled, sometimes forming bundles, fre-
quently adhering to and growing out from filamentous algae which
have non-mucilaginous walls; filaments up to 3.24 in diameter,
sheaths thin; trichomes 2.5-3n in diameter, cells 1.5-3.54 long;
apical cell convex, smooth.
This is a very common species in hard water habitats and is in-
variably found associated with Cladophora and Rhizoclonium. It
is similar in some characters and in habitat to Lyngbya epiphytica
Wille (Nyt Mag. f. Natur., 1913, p. 25), a synonym of L. Nord-
gaardii Wille, but in our region is slightly larger than that species.
Mich., Wis.
Lyngbya epiphytica Hieronymus in Engler & Prantl 1900, p. 67
Pl. 112, Figs. 2,3
Plants epiphytic, entangled and spirally twisted about other
filamentous algae to which they are adjoined throughout their en-
tire length; filaments 1.5-2.5y in diameter; trichomes without con-
strictions at the cross walls; cells 1.2-2u in diameter, 1-2» long;
apical cell convex, not capitate; sheath thin and close.
This species is not to be confused with L. epiphytica Wille, which
is synonymous, apparently, with L. Nordgaardii Wille (Frémy, Soc.
Arch. et Hist. Nat. Manche, 47, p. 44, 1936).
On filamentous algae. Tychoplankter. Wis.
[ 500 ]
Lyngbya Hieronymusii Lemmermann 1905, p. 146
Pl, 112,' Fig. 4
Plants solitary, scattered among other algae or in littoral plankton.
Trichomes straight and not tapering at the apices, which are broadly
convex; 11-13 in diameter. Cells 45-15 as long as wide (2.7—-4u
long); usually with pseudovacuoles; not constricted at the cross
walls, which are granular. Sheath rather thick, but homogeneous,
not lamellose. Filaments (12)-14-19, wide.
This species should be compared with L. major Menegh. and L.
Birgei G. M. Smith. From the former it differs in the convex, non-
tapering apices, the homogeneous sheaths, and its failure to form
agglutinated masses. From the latter species it differs in size and in
its possession of granular cross walls.
Tychoplankter. Mich., Wis.
Lyngbya Lagerheimia (Moebius ) Gomont 1890, p. 354
Pl. 112, Figs. 5, 6
Plants solitary or somewhat entangled, bent and twisted, some-
times spiral; trichomes not at all or but very slightly tapering toward
the apices, which are broadly conical or convex; cells 2.2—-3y in
diameter, 1.5-2.8. long; cell contents coarsely granular; sheaths
thin; filaments 2-2.5, wide.
Among other algae in shallow water of lakes and in roadside
ponds. Mich., Wis.
Lyngbya latissima Prescott 1944, p. 372
PI. 112, Fig. 9
Plants solitary, planktonic, entangled among other floating algae;
trichomes straight, not tapering toward the apices; cells disc-like,
with contents finely and evenly granular (sometimes with coarse
granules in old plants), 37-40.7 in diameter, 3.7-7.4y long; sheaths
thick, 3.7-5» wide, lamellated, with outer layers wrinkled and
roughened in age; filaments 44-58, in diameter.
This species, found in but two habitats, may be a planktonic and
unbranched expression of Plectonema Wollei. The plants described
by Prescott (1944, p. 372) are about the same diameter as this
large species of Plectonema, and they have some of the same sheath
characteristics. The filaments are entirely unbranched and solitary,
however, whereas Plectonema Wollei is branched (although infre-
quently) and occurs in woolly mats. Lyngbya latissima should be com-
pared also with Oscillatoria princeps when the latter is in a hor-
mogonous condition and inclosed by a sheath. The sheath is not
thick and lamellated as in our plant, nor are the trichomes so long.
[ 501 |
L. gigantea Lewis, Zirkle, and Patrick (1933), referred by Drouet
(1938) to Oscillatoria princeps, differs in having thin smooth
sheaths characteristic of the hormogonial phase of the latter. Our
specimens are not at all tapering at the apices, and the contents of
the cells are granular.
Lyngbya Hummellii Borge (1934), a large species, differs from
L. latissima in its smaller size (874, maximum width) and in the
longer cells (6-11). Also the sheath of Borge’s species is thinner
and apparently not lamellated as in our specimens.
Euplanktonic and tychoplanktonic. Wis.
Lyngbya limnetica Lemmermann 1898d, p. 154
Pd igo,
Plants straight, solitary, planktonic; trichomes 1-2-(2.5)y in
diameter, not tapering at the apices; cells 6-12 long, not con-
stricted at the cross walls; cell contents coarsely granular; sheaths
thin and colorless; filaments 2—2.2u wide.
Euplankter. Wis.
Lyngbya major Meneghini 1837, p. 12
P1112, Fig. 10
Plants solitary among other algae, or somewhat gregarious, but
not forming expansions or plant masses; filaments straight; tri-
chomes not or but very slightly tapering to the apices, which are
indistinctly capitate in older plants, 11-17 in diameter; cells 14-
1/4 as long as wide, (2)—3.5—4u in length, not constricted at the
cross walls, which are definitely granulose; cell contents homogen-
eously granular; sheaths thick (3-3.7,), firm, and usually lamellated,
becoming roughened in age; filament 22-26, in diameter.
Caught about Utricularia and other vegetation; widely distributed
in a variety of lakes, mostly hard water; tychoplanktonic. Mich., Wis.
Lyngbya Martensiana Meneghini 1837, p. 23
Pl. 112, Fig. 11
Plants much entangled and interwoven to form an expanded,
dark blue-green mass; trichomes 6—10—(12)y in diameter, not
tapering toward the apices, which are broadly convex; cells about
1/4 as long as wide, 2.5—2.84 long, not constricted at the cross
walls, contents homogeneous except for 1 or 2 conspicuous gran-
ules at the cross walls; sheaths firm, moderately thick (1.5—2,);
filaments mostly 6—10» (up to 14.) in diameter.
This plant is assigned here on the basis of size, lack of constric-
tions at the cross walls, and the tendency to form plant masses. It
[ 502 }
is similar to L. putealis Montagne, but that species has trichomes
constricted at the cross walls. Our specimens should be compared
also with L. major.
Rare; in tychoplankton. Mich., Wis.
Lyngbya Nordgaardii Wille 1918, p. 32
[Lyngbya epiphytica Wille 1913, p. 25]
Pl. 118, Figs. 1, 2
Plants solitary or forming minute patches on the walls of larger
filamentous algae (Oedogonium, Rhizoclonium), curved and vermi-
form, sometimes recurved from a basal attachment; trichomes gray-
green, not tapering at the apices, 1.2-2 in diameter, about as long
as wide or a little shorter; sheaths very thin and transparent.
On Drepanocladus from a depth of 35 feet; on filamentous algae,
and in tychoplankton. Wis.
Lyngbya purpurea (Hook. & Harvey ) Gomont 1892, p. 49
Plant mass highly mucilaginous, purplish red; trichomes some-
times scattered among other algae, curved and flexuous, not con-
stricted at the cross walls, 1.4-1.8. in diameter; sheath thin and
transparent, not stained blue by chlor-zinc-iodide; cells quadrate.
Mich.
Lyngbya spirulinoides Gomont 1890, p. 355; 1892a, p. 146
Pld), aig. 1
Plant mass planktonic, olive-green; filaments entangled, loosely
spiralled through most of their length (or all of it), rarely straight;
cells light blue-green, with homogeneous or slightly granular con-
tents; sheaths thin and homogeneous, sticky and colorless; trichomes
14-16, in diameter, not constricted at the cross walls nor tapering
toward the apices; apical cell broadly rounded, not capitate, and
without a calyptra; cells 3.46.8» long.
Tychoplankter. Wis.
Lyngbya Taylorii Drouet & Strickland in Strickland 1940, p. 631
Pl. 118, Fig. 3
Plants forming tufts of parallel but flexuous filaments on sub-
merged substrates, or floating free. Trichomes not tapering toward
the apices; very little or not at all constricted at the cross walls;
4-7, in diameter. Terminal cell broadly convex. Cells quadrate,
about as long as wide or a little shorter; cell contents granular.
Sheaths thin and colorless; filaments long, 6-9» in diameter.
Forming a bright blue-green film on mud; tychoplankter. Wis.
[ 503 ]
Lyngbya versicolor (Wartmann) Gomont 1892a, p. 147
Pl. 113, Fig. 4
Plants forming a mucous expansion on submerged objects, be-
coming detached and floating; filaments much entangled; trichomes
not tapering toward the apices and not constricted at the cross
walls, which are not granular; cells 2.8-3.44 in diameter; filaments
3-3.8-(5) in diameter; sheaths thick (up to 2), mucous.
Forming compact films on submerged logs; tychoplankter. Mich.,
Wis.
SYMPLOCA Kuetzing 1843, p. 201
Unbranched sheathed filaments, united in branching bundles or
fascicles which are erect or growing out and away from the sub-
strate to which they are attached (rarely free-floating); trichomes
uniseriate and straight, tapering distally but very slightly; apical
cell conical or broadly rounded, sometimes with a thickened outer
membrane; sheaths firm and close, or confluent in the median
portion of the filament only, thus producing the effect of false
branching; cells quadrate or cylindric, slightly, if at all, constricted
at the cross walls.
Symploca muscorum (C. A. Ag.) Gomont 1890, p. 354
Pl. 113, Fig. 7
Filaments forming brownish-green, erect or procumbent tufts
or fascicles (often producing Phormidium-like expansions); tri-
chomes straight or wavy, parallel; cells quadrate to cylindrical, not
constricted at the cross walls, 5-8. in diameter, 5-11, long; cell
contents densely granular; apical cell broadly rounded or obtuse-
conical; sheaths firm, thin, close.
Along sides of ditches and in Sphagnum bogs; rare in our collec-
tions, although a widely distributed and common species. Mich., Wis.
HYDROCOLEUM Kuetzing 18438, p. 196
Trichomes few to several in relatively wide, lamellate, and color-
less sheaths, which are in part close and definite, becoming diffluent,
the sheaths sometimes branching; forming a cushion-like expanse
(sometimes lime-encrusted ); individual trichomes tapering slightly
at the apices, the terminal cell usually capitate and sometimes with
a calyptra; cells quadrate or shorter than wide.
Hydrocoleum oligotrichum A. Braun in Rabenhorst 1865, p. 294
Plant mass cushion-like, lime-encrusted, and brownish in color;
trichomes clustered in bundles, 2-6 within a lamellate sheath,
[ 504 J
golden-brown in color, tapering toward the apex, which is capitate;
cells 6-8» in diameter, 3-9, long.
In small pools on rock cliffs, Pictured Rocks, Michigan.
MICROCOLEUS Desmaziéres 1823, p.7
Plant mass consisting of many parallel trichomes inclosed by a
wide, gelatinous, homogeneous and sticky sheath; trichomes with
basal-distal differentiation, tapering anteriorly to conical or capitate
apices, closely entwined, sliding upon one another in and out of
the sheath; cells quadrate or elongate-cylindric; contents granular
but without pseudovacuoles; cross walls sometimes granular; plants
mostly on moist soil, sometimes submerged on old wood in a gela-
tinous mixture of miscellaneous blue-green algae.
This genus should be compared with Schizothrix, which has firm
colored sheaths, often forms erect tufts or fascicles of filaments, and
is seldom aquatic.
Key to the Species
i PAnical cell capitate ete Se it eles ela i M. vaginatus
i Apical cell. nok-capitate <7 A. a aS 2
2. Trichomes 4—5u in diameter, constricted
Sistine .CrOss Wallssw AM UAliC ee oe en ee M. lacustris
2. Trichomes 5—7u in diameter, not constricted at the cross walls;
plants teuallysonymoistisoll+ = #2 ee ee M. paludosus
Microcoleus lacustris (Rab. ) Farlow in Farlow, Anderson, &
Eaton 1877, Algae Amer. Bor. Exsic., No. 227
Pl. 113, Fig. 6
Aquatic; forming dark blue-green patches on submerged wood
or on bottom. Sheaths colorless, confluent with the sheaths of other
filaments, thin and evanescent at the ends; not stained by chlor-zinc-
iodide reagent. Trichomes with bluntly tapering apical cells, not
capitate; 4-5, in diameter. Cells distinctly cylindrical, constricted
at the cross walls; 8-14, long; contents finely granular, blue-green.
Among other filamentous blue-green algae in tychoplankton and
adhering to submerged substrates. Mich., Wis.
Microcoleus paludosus (Kuetz.) Gomont 1892, p. 358
Pl. 113, Fig. 5
Filaments either solitary among other algae or entangled to form
dark green, thready masses; sheaths either closed and pointed (some-
times forked) or open; sheaths sticky but not especially confluent,
not colored by chlor-zinc-iodide reagent; trichomes compactly en-
twined, tapering to blunt, conical apices, which are not capitate;
[ 505 J
cells 5-7 in diameter, 7-13-(14) long, not constricted or granular
at the cross walls; cell contents bright blue-green.
On moist soil at margins of lakes; tychoplanktonic. Mich., Wis.
Microcoleus vaginatus (Vauch.) Gomont 1890, p. 353
Pl. 131, Fig. 2
Plants solitary or, more often, forming dark green and shiny hori-
zontal layers; twisted and branched. Sheath colorless and either
cylindrical throughout or irregularly undulate and wrinkled; not
stained by chlor-zinc-iodide reagent; agglutinated and either open
at the end or closed and diffluent. Trichomes numerous within the
sheath; not constricted at the cross walls, which are often granular;
tapering slightly and briefly at the apex, which is straight. Apical
cell capitate, with a calyptra. Cells 3.5-7p in diameter, 14-2 times
as long as wide.
Mich.
SCHIZOTHRIX Kuetzing 1843, p. 230
Plant mass consisting of several to many trichomes inclosed by a
copious sheath of mucilage, which is usually firm and not sticky,
the sheath colorless or yellowed, especially in age, frequently forked
towards the ends with but a single trichome in the ultimate divisions;
filaments either single, in fascicled tufts, or in an expanded layer;
trichomes twisted and intertwined, cylindrical throughout but with
the apical cell tapering to a blunt or sharp point; cells cylindrical,
or shorter than wide, sometimes constricted at the cross walls.
This genus should be compared with some species of Phormidium
in which the sheaths are agglutinated and diffluent.
Key to the Species
isaSheathsy colored ese sts Pes tetg tn ws oly ek ee A 8 eee 2
1 $Sheathsacolorlessrt+lti nd et eels Pd ray Ante i ae ee 3
2. Trichomes 2.8—8u in diameter, not tapering
at the apices, the end bluntly rounded_______________________----- S. fuscescens
2. Trichomes 6-13» in diameter, tapering slightly toward the
apices; tne end\ canically rounded = 2 S. Muelleri
3. Filaments compactly agglutinated to form erect tufts_____________. S. Friesii
3. Pilaments notpapelutinated: to stom erect tuikts =e ee ee 4
4, Filaments branching but very little,
ainited: toform'-horizontalilayers=— >!) Se eee S. lardacea
4. Filaments forming cushion-like masses, or
penicillate, streaming ytuits= 2S eS SS 5
5. irichomes:>—Ullpeimydiameter sash Jeeeo e |
istallyiby, arsingleycell (ne ee A. limnetica
. Gonidia spheroidal or broadly ovate, separated from the
lieteracyst by 2 or more cells= A. planctonica
. Gonidia short-cylindric, not more than twice the diameter in
length, hexagonal in optical cross section. A. macrospora
. Gonidia usually more than twice the diameter in
length, round in optical cross section _—--------—---—-----—----_~--_------ Wa
[ 511 ]
a(GOMIGTaiMaSeTICS = = sd et ae Ee ee ee ee A. Felisii
17
bie, Gonidiay solitary 3) <2. 8. 15s See eS ee ee eee ieee ke, eee 18
18. Vegetative cells 4u in diameter, 4—-6u long; gonidia slender, 6u in
diameter and up to 56—(70)w long................ A. Augstumalis var. marchica
18. Vegetative cells 4—6u in diameter; gonidia larger,
(fc =) Syrah baWECo bE 0cVel (=) pee meee eet te NT oe AS ie ee ee 19
19. Vegetative cells 4—6u in diameter; gonidia more than twice the
diameter ofthe vegetative; cells) 2 aa ee ee A. Levanderi
19. Vegetative cells 5-6u in diameter; gonidia less than twice the
diameter ofthe; vepetative Cellsiss sae se esneeenemnsanaemne ene See A. affinis
20. Gonidia developing adjacent to the heterocysts —-__.._--____________-__=_ 21
20. Gonidia developing remotely from the heterocysts, scattered 25
21. Vegetative cells globose or barrel-shaped ...-- De,
21s) Vegetative cellsycyling tical 26 roasts tae A. subcylindrica
Zon Vegetative cells 4=—Oye in Cidmieter mee st mise eke ee, one eee 23
220) Vegetative cells (lar genie ata teen) oo Wes Lireeenl pein used sek eens 24
23. Gonidia cylindrical, with lateral margins parallel ___________ A. oscillarioides
23. Gonidia elongate-ovate, with lateral margins convex... A. torulosa
24. Vegetative cells 7.5-9u in diameter; gonidia
UL BSG (Mey Nn Soy Ole A. lapponica
24. Vegetative cells 12u in diameter; gonidia 15—20u in diameter. A. Bornetiana
Zo. Vegetativercells cylindrical +2 432 he Se ee ee 26
25. Vegetative cells ovate, barrel-shaped, or truncate-globose —..._____ 27
26. Gonidia usually in series, 10-12y in diameter, with a smooth outer
membrane; vegetative cells 6-74 in diameter_._...-_____-__________. A. Felisii
26. Gonidia 1 or 2 together, 3.7-4-(7)u in diameter, with a rough
outer membrane; vegetative cells 3-4u in diameter —_______ A. verrucosa
. Trichomes lying somewhat parallel in a thin mucilaginous layer,
usually extending over the surface of large filamentous algae or
stems of aquatic plants; heterocysts round, 4—6u in diameter A. inaequalis
. Trichomes not parallel; irregularly entangled
or solitary ‘among jother algad = 20 Se 28
* Heterocysts) spherical 2. 0 ee ae ee A. affinis
» Heteroeysts elongate-ovate or ellipsoid! 2. 29
» (Gonidia,in*series, OVvate or subglobose -.....2 22. er 30
. Gonidia 1 or 2 together, elongate to subcylindric ______-___ A. aequalis
» Gonidia barrel-shaped, /.5—14p longs. A. variabilis
. Gonidia oblong, often with retuse margins __________________________-- *A. catenula
Anabaena aequalis Borge 1907, p. 65
Pl. 115, Figs. 1, 2
Trichomes straight, forming a small plant mass, or scattered
among other algae; cells somewhat quadrate or barrel-shaped,
(4.5)-5.5-7.5u in diameter, 7.6-8.5y long; heterocysts ovate to sub-
cylindric, (5.5)-8. in diameter, (10)-13-(15.2)» long; gonidia
cylindrical, remote from the heterocysts, the wall smooth and color-
less, 5-7.6u in diameter, (21)-385-41-( 49.4), long.
Tychoplanktonic; intermingled with other algae in shallow water
in Sphagnum bogs. Wis.
[512 }
Anabaena affinis Lemmermann 1898a, p. 261
Pl. 115, Figs. 10, 14, 15
Trichomes straight or flexuous, solitary and free-floating, either
planktonic or intermingled with other algae in the littoral flora,
inclosed in a thin, wide, mucilaginous sheath (often indistinct);
cells spherical to spheroidal with either homogeneous contents or
with pseudovacuoles, especially the latter when plants are solitary
in the plankton, 5-6-(7) in diameter; heterocysts spherical, slightly
larger than the vegetative cells, 7.5-10, in diameter; gonidia usually
short-cylindric, sometimes broadly ovate and ‘truncately rounded
at the poles, scattered, solitary, 9.5—12y in diameter, 17—24—(26)p
long.
Rare to common in euplankton and tychoplankton of several
lakes. Mich., Wis.
Anabaena Augstumalis Schmidle 1899a, p. 174
Trichomes twisted and flexuous, free-floating, solitary; cells barrel-
shaped or somewhat cylindric, 4—5p in diameter, 5-6, long; hetero-
cysts cylindrical, slightly greater (64) in diameter than the vegeta-
tive cells; gonidia narrowly cylindric, 6. in diameter, 30-50-(56) »
long, adjacent to the heterocysts.
This species should be compared with A. circinalis, also a plankter.
Euplankter. Wis.
Anabaena Augstumalis var. Marchica Lemmermann 1905, p. 147
Pl. 115, Fig. 11
Trichomes flexuous (not circinate), planktonic; cells spherical to
cylindric with many conspicuous pseudovacuoles, 5-7 in diameter,
5-9.5u long; gonidia cylindrical, 9.5-12» in diameter, 40-70» long,
remote from the heterocysts.
In the plankton of several hard water lakes. Mich., Wis.
Anabaena Azollae Strasburger 1884, p. 352
Pl. 115, Figs. 12, 13
Trichomes straight or coiled, often in small clusters but more
frequently solitary, inhabiting the tissues of Azolla; cells subglobose
to ellipsoid, the contents granular, 4-5y in diameter, 6-8-(9.5) uw
long; heterocysts ovate, 6-9.5. in diameter, 9-10-(11.5)» long;
gonidia not known.
The lack of gonidia in these plants makes their identification
questionable. It is possible that they are only a sterile condition
of a free-living species called by another name.
In the tissues of Azolla; shallow water and sloughs. Wis.
[ 518 ]
Anabaena Bornetiana Collins 1896, p. 120
Pl. 115, Figs. 8, 9
Trichomes straight, planktonic and solitary; cells spherical or
compressed globose, contents densely granular or homogeneous,
11-12 in diameter; heterocysts nearly spherical, 10-12-(14), in
diameter, 12-14-(20) long; gonidia cylindrical, adjacent to the
heterocysts (often one on either side) or scattered, (12.8 )—14—(20)
in diameter, (50 )—66-90, long.
Plankter; in lakes. Wis.
Anabaena circinalis Rabenhorst 1852, p. 209
BIG Sigs 2
Trichomes planktonic, flexuous and contorted; solitary or entangled
to form floating clots which are easily visible to the unaided eye.
Cells spherical or depressed-globose from contact; 8-12-(14), in
diameter. Heterocysts spherical or compressed, 8-10» in diameter.
Gonidia remote from the heterocysts, rarely adjacent; cylindric,
straight or curved; (14)-16-18, in diameter, 22-30-(32), long.
This species is very common and widely distributed. It is often
found associated with A. spiroides in the plankton of hard water
lakes. These two species, together with Microcystis aeruginosa and
Gloeotrichia echinulata, are conspicuous components of water
blooms during late summer periods.
Anabaena circinalis may be differentiated from A. spiroides by
the shape of the spore when in the reproductive condition, by the
lack of regularity in the twisting of the trichome, and by the size of
the cells in the vegetative state.
Mich., Wis.
Anabaena circinalis var. macrospora ( Wittr.) DeToni 1907, p. 445
Pl. 116, Figs. 5,6; Pl. 120, Fig. 1
A variety with smaller vegetative cells and narrower, more elon-
gate gonidia. Cells 7-8 in diameter; heterocysts 7.5-10, in diameter;
gonidia 9-10.5y in diameter, 28-42, long.
Euplankter. Wis.
Anabaena Felisii (Menegh.) Bornet & Flahault 1888, p. 232
Pl. 116, Figs. 3, 4
Trichomes straight; solitary or in small clusters. Cells short-
cylindric, 6-7 in diameter, 7-llp long. Heterocysts ovate to sub-
cylindric, 7» in diameter, 12-14» long. Gonidia scattered; solitary
[514 ]
or in short series; remote from the heterocysts; 10-12-(14), in
diameter and up to 70, long.
This species should be compared with A. oscillarioides, from
which it differs in having spores remote from the heterocysts, which
are subcylindric rather than round. The cells in A. Felisii are cylin-
drical, whereas those of A. oscillarioides are barrel-shaped.
Tychoplankter. Wis.
Anabaena flos-aquae (Lyngb.) De Brébisson in
De Brébisson & Godey 1836, p. 36
[A. Lemmermannii P. Richter]
PING: Fig. 7
Trichomes planktonic; very flexuous and contorted, sometimes
coiled in an irregular spiral fashion; either solitary or entangled in
a twisted mass. Cells spherical to subcylindric; (4)-5-6-(8), in
diameter, 6-8—(12) » long; cell contents granular with conspicuous
pseudovacuoles. Heterocysts globose or somewhat depressed at the
poles; 7-9» in diameter, 6-10, long. Gonidia cylindrical or sausage-
shaped; solitary, or sometimes in a series, crowded near the center
of a tangle of filaments; usually adjacent to the heterocysts; (6)-8-
12-(13), in diameter, (20)-—24-30-(50)» long.
Common in the plankton of hard and semi-hard water lakes;
sometimes producing conspicuous water bloom growths during the
warm summer months, often in association with Microcystis aeru-
ginosa and Gloeotrichia echinulata. Mich., Wis.
Anabaena flos-aquae var. Treleasei Bornet & Flahault 1888, p. 230
[A. Mendotae Trelease 1889, p. 123]
Pl. 120, Fig. 2
A variety differing from the typical by the somewhat smaller size
of the vegetative cells and by the more slender gonidia; vegetative
cells 41 in diameter. Heterocysts 5 in diameter, 10» long. Gonidia
6. in diameter, 40, long.
Forming dense water blooms. Wis.
Anabaena helicoidea Bernard 1908, p. 52
Pl. 116, Fig. 8
Trichomes free-floating; solitary or entangled in a group; spirally
twisted throughout their length. Cells ovate or somewhat barrel-
shaped, with large granules of food reserve, 3.5-3.8. in diameter,
4-5 long. Heterocysts globose, 5-6» in diameter, 6 long. Gonidia
small, cylindrical, 54 in diameter, 17» long.
This species is quite similar to A. flos-aquae but is separated pri-
[ 515 ]
marily on the form of the plant, which is a loose spiral, not a
tangled knot. It also should be compared with A. circinalis which
has gonidia of quite different shape, relatively longer and larger.
Euplankter. Wis.
Anabaena inaequalis (Kuetz.) Bornet & Flahault 1888, p. 231
[A. laxa (Rab.) Braun ex Bornet & Flahault 1888, p. 120]
Pl. 116, Figs. 9, 10
Trichomes straight or slightly twisted; lying parallel and entwined
and inclosed by a definite sticky sheath, 7.4-8. wide; forming
gelatinous strands, entangled among other algae and adherent
(sometimes floating free). Cells short barrel-shaped or truncate-
globose, 3.7-4.2-(5) in diameter. Heterocysts globose or ovate,
4-6» in diameter, 7.24 long. Gonidia cylindrical, scattered, with
wall often golden-brown when mature; 6-8» in diameter, 15—-16—
(17) long.
Among other algae and floating free in marginal waters. Mich.,
Wis.
Anabaena lapponica Borge 1913a, p. 101
PL. 116 Fig. 11
Trichomes straight, somewhat entangled; cells globose, 7.4-9.2u
in diameter; heterocysts globose, 7.4-10 in diameter; gonidia cylin-
drical, (11.5)-13-14-(17) in diameter, 40.7-63—( 85) » long, develo-
ping on one or both sides of the heterocysts.
Type specimens of this plant have not been seen for confirmation,
but our material agrees with Borge’s description. The spherical
shape of the vegetative cells and heterocysts separate this species
from A. oscillarioides, which has barrel-shaped or elongate-ovate
vegetative cells and heterocysts.
Tychoplanktonic in lakes; in roadside ditches. Wis.
Anabaena Levanderi Lemmermann 1906b, p. 536
PI117, Figs. 1,2
Trichomes planktonic, solitary, straight or flexuous. Cells cylin-
drical, 4-6 in diameter, 11-33, long; constricted at the cross walls,
which are rounded; contents with pseudovacuoles. Heterocysts
spherical to ellipsoid, 6.5-8, in diameter, 6.5-9.5-(14)» long. Gon-
idia solitary, ellipsoid, 8—15y in diameter, 19—45y long.
Euplankter. Wis.
Anabaena limnetica G. M. Smith 1916, p. 481
PIAL, Fig..3
Trichomes planktonic, solitary, straight or flexuous, inclosed by
[ 516 |
a mucilaginous sheath. Vegetative cells spherical or compressed at
the poles, (10)-12-14-(15) in diameter. Heterocysts globular,
10—14, in diameter. Gonidia broadly ovate, near to the heter-
ocysts or scattered, 17-20 in diameter, 20-30, long.
Euplankter. Mich., Wis.
Anabaena macrospora Klebahn 1895, p. 269
Pl. 117, Figs. 4-6
Trichomes planktonic, straight or flexuous, solitary; cells globose
or somewhat ellipsoid, 5-6.5. in diameter, (5)-6-8-(9), long;
heterocysts spherical, about 6, in diameter; gonidia globose to ovate,
angular in optical section, not adjoining heterocysts, 17—18.5u in
diameter, 24—26, long.
Plankter; in many hard and semi-hard water lakes. Wis.
Anabaena macrospora var. robusta Lemmermann 1898d, p- 154
Pl. 7, Fig. 7
Trichomes planktonic and solitary. Cells globose or ellipsoid,
9.7-11 in diameter. Heterocysts globose, 11.54 in diameter, 11-12y
long. Gonidia globose or ovate; scattered, or adjacent to the heter-
ocysts; 13.2-15, in diameter, 27-28-(34) » long.
Plankter; in several hard water lakes; often appearing in water
bloom associations in late summer. Wis.
Anabaena oscillarioides Bory 1822, p. 308
Pl. 117, Figs. 8-10
Filaments straight, or entangled in a thin gelatinous layer or soli-
tary. Cells barrel-shaped or truncate-globose, 4—6u in diameter,
7.8-8 long. Heterocysts round or ovate; 6-8» in diameter, (6)—
9.2-(10) long. Gonidia cylindrical; developing on both sides of
the heterocyst (rarely on one side only); 8-10-(15.2) in diameter,
20-40-(76) » long.
Spores in our specimens are larger than those originally described
for this species.
Forming thin films on submerged aquatics, or subaerial in swampy
places and along margins of lakes. Mich., Wis.
Anabaena planctonica Brunnthaler 1903, p. 292
Pl. 118, Figs. 1-3
Trichomes solitary, free-floating, inclosed in a wide gelatinous
sheath; cells barrel-shaped or spherical, 9-15» in diameter, 6.5-10
long, with pseudovacuoles; heterocysts spherical, with lateral ‘wings’
of mucilage, 9—l1p in diameter; gonidia ellipsoid, 10—14, in diam-
eter, 15-30, long, near or remote from the heterocysts.
Plankter; in lakes. Wis.
[al]
Anabaena Scheremetievi Elenkin 1909, p. 125
Pl. 117, Figs. 11, 12
Trichomes planktonic; mostly straight, sometimes flexuous with a
gelatinous sheath. Cells spheroidal or barrel-shaped; with pseudo-
vacuoles; 8.5-9-(11)» in diameter, 8-11-(12)» long. Heterocysts
spherical, 8-10.8, in diameter. Gonidia spherical to ellipsoid, some-
times angular in optical section, not adjacent to heterocysts, (18)
—20—22.6» in diameter, 21—24u long.
Euplankter. Wis.
Anabaena spiroides Klebahn 1895, p. 268
Trichomes spiral, solitary, inclosed in a thin mucilaginous sheath.
Cells spherical or compressed-spheroidal, 6.5—-8 in diameter. Hetero-
cysts spherical, slightly smaller than the vegetative cells. Gonidia
spherical, 14 in diameter; adjacent to the heterocysts.
Typical form not reported from our region.
Anabaena spiroides var. crassa Lemmermann 1898d, p. 155
Pl. 117, Fig. 13; Pl. 118, Figs. 4,5
Trichomes solitary, spirally twisted, planktonic. Cells spherical,
10-11.5y in diameter. Heterocysts subspherical, 10u in diameter, 12
long. Gonidia oblong; remote from the heterocysts; 19-20, in diam-
eter, 25-30p long.
Plankter; in many lakes; especially abundant in late summer,
appearing in water blooms with A. circinalis and A. flos-aquae. Wis.
Anabaena subcylindrica Borge 1921, p. 12
Pl. 118, Figs. 6-8
Trichomes straight; solitary or forming a thin layer; adherent on
submerged aquatics and entangled among other algae. Cells short-
cylindric, 44.5» in diameter, 5.5-8—(10) long. Heterocysts cylin-
drical, 5-7.5-(10) in diameter, 15—(18) long. Gonidia cylindrical,
adjacent to heterocysts, 7—8.5u in diameter, 54—57p long.
Sphagnum bogs; tychoplanktonic in soft water lakes. Wis.
Anabaena torulosa (Carm.) Lagerheim 1883, p. 47
Filaments somewhat straight or irregularly bent (not coiled);
forming sparsely clustered flakes. Cells subspherical or barrel-
shaped, 4.2-5 in diameter; the terminal cell conical. Heterocysts
globular, 6 in diameter. Gonidia elongate-ovate to subcylindric,
with smooth convex lateral walls; solitary or in a series, on either
side of the heterocyst; 7-12 in diameter, 18-28, long.
Mich.
[ 518 ]
Anabaena unispora Gardner 1927, p. 59
PI. 131, Fig.5
Filaments straight or slightly curved, mostly solitary. Cells rec-
tangular, 2-4 times longer than wide; 4-5, in diameter, 11-20, long;
slightly constricted at the cross walls. Heterocysts elongate-ovate or
subcylindric, 6 in diameter, 11y long. Gonidia solitary; developing
near the middle of the filament and close to the heterocyst; elongate-
ovate, the margins subparallel or slightly convex; 11-15,» in diameter,
31-35, long.
Mich.
Anabaena variabilis Kuetzing 1843, p. 210
Pl. 118, Figs. 9, 10
Trichomes entangled in a gelatinous plant mass, on damp soil, or
floating entangled among other algae. Cells compressed-globose,
3.7-4-(6.5) in diameter. Heterocysts globular or ovate; 5.5-5.8-
(8) in diameter, 5.8-6.5, long. Gonidia ovate; in series; remote from
the heterocysts; 6.8—9 in diameter, 7.5-8.2—(14)» long.
In seeps and ditches. Mich., Wis.
Anabaena verrucosa Boye-Petersen 1923, p. 299
PIS. Figs. 11512
Trichomes straight, parallel, with a wide gelatinous sheath; grow-
ing on and adherent to other filamentous algae. Cells short-cylindric,
3.3-4n in diameter, 3.3-6-(8) long. Heterocysts cylindrical, 3.6,
in diameter, 5h long. Gonidia cylindrical; remote from the hetero-
cysts; 4~7p in diameter, (10.5)-12-(15) long.
Tychoplankter. Wis.
PAnabaena Viguieri Denis & Frémy 1923, p. 122
PI. 119, Figs. 1-3
Trichomes planktonic; straight. Cells barrel-shaped to short-
cylindric; 77.8 in diameter, (4)-9-10u long; with pseudovacuoles.
Heterocysts globose to subglobose; 7.6. in diameter and up to 9u
long; smaller than the vegetative cells. Gonidia broadly ovate;
12-14-(15) in diameter, 17-18.5p long; solitary or in 2’s; not ad-
jacent to the heterocyst.
This interesting plant was found in but one collection made in
our area. It agrees in most respects with the description of A.
Viguieri, but the cells are slightly longer.
Euplankter. Wis.
[ 519 ]
Anabaena wisconsinense Prescott 1944, p: 378
Pl. 115, Figs. 3-7; Pl. 119, Figs. 4-8
Trichomes planktonic; straight or slightly flexuous; solitary or
(more often) aggregated in parallel fashion to form small, loose,
flake-like bundles; without a sheath; not tapering at the apices.
Cells quadrate to cylindrical; constricted at the cross walls; 3.64
in diameter, 3.6—10.8 long; with large pseudovacuoles. Heterocysts
spherical or compressed-globose, 3.6—-4.24 in diameter; only 1 in
each trichome, centrally located. Gonidia elliptic-ovate to broadly
oval, 7.2-8 in diameter, 10-13 long; beginning their development
as a series of 3 enlarged vegetative cells, of which usually only 1
matures, so that each trichome has but a single gonidium (if more
than 1, the gonidia in pairs); remote from the heterocysts.
This plant is remindful of Aphanizomenon flos-aquae. It should be
compared with Anabaena aphanizomenoides Forti, from which it
differs in its smaller size throughout, in the shape of the gonidia,
and in the location of the gonidia (remote from, rather than adjacent
to, the heterocysts ).
Both euplanktonic and tychoplanktonic. Wis.
ANABAENOPSIS (Wolosz.) Miller 1923, p. 125
Trichomes planktonic; short and coiled, with a heterocyst at either
end. Cells elongate-ovoid to subcylindric. Akinetes intercalary, re-
mote from the heterocysts.
Anabaenopsis Elenkinii Miller 1923, p. 125
PI. 131, Fig..4
Trichomes composed of ellipsoid or elongate-ovoid cells which
contain pseudovacuoles. Heterocysts spherical, 4.6-6.7» in diameter.
Akinetes broadly ovoid, 8.3-10.5u in diameter, 9.3-12 long; some-
times nearly spherical, 8.3-10.7, in diameter. Cells 4.6-5.7y in
diameter.
Cheboygan County, Michigan.
NOSTOC Vaucher 1903, p. 203
Membranous or globular or irregularly lobed colony of tangled,
uniseriate unbranched trichomes of globose and bead-like, barrel-
shaped, or cylindrical cells, inclosed in copious, thick mucilage
which (in many species) outwardly forms a firm integument, giving
the colony a fixed and definite shape; individual sheaths of the
trichome confluent with the colonial mucilage; trichomes without
basal-distal differentiation, made up of vegetative cells, frequent
[ 520 ]
heterocysts and, when mature, gonidia which are either solitary or
in series.
This genus should be compared with Anabaena in which some
species have trichomes similarly inclosed in a thick mucilage but
for which there is no definite shape. The colonial mass in Anabaena
is soft, spreading, and does not retain its shape when removed from
the water.
Key to the Species
1. Plants inhabiting the tissues of Ricciocarpus
and ROtherwlivernwOnts = ee es eee See Saree N. sphaericum
(See also N. punctiforme. )
i) Plants dree-living, aquatic, or subserial 2. 2
2. Colonies globular masses of microscopic size,
attached or entangled among other algae_______________ N. paludosum
DeRSOl@Hics (ot sinc hOSCODICUSIZG == mee oe ee 3
3. Colony a membranous expanse, usually Subacha N. muscorum
(See also N. Linckia and N. commune.)
3. Colony globular, regular in shape or lumpy and warty; mostly aquatic 4
4, Trichomes inclosed in a thick, tough, wrinkled mucilage, at first
globular and solid, later becoming hollow and irregularly tuber-
cular; colonies olive-green or brownish; trichomes densely en-
tangled at the periphery of the colonial mass. N. verrucosum
4, Trichomes not in leathery, hollow, tubercular Colonies = ee ee 5
5. Colonies spherical, planktonic, blue;
Pe erynia a vGd IMIG LOR: = roe oh SS N. caeruleum
5. Colonies not definitely planktonic; not blue 6
6. Colonies with a firm outer membrane; definite
in shape; usually globular —_______ SER Seen Gi ne Ain A ls SR a tt 7
6. Colonies without a firm outer membrane or integument; usually
soft and amorphous, although retaining their shape when re-
THOU LaCO Dy ava Ry ee eS ee eS eee 11
q. Plants! growmay on! moist Sol 9
fe blants) crowing nh) Water ee ee ee 8
8. Cells 4-5u in diameter; gonidia elliptic or spherical, 5-7y in
diameter; colonies tuberculate or expanded irregularly N. sphaericum
8. Cells 4—6y in diameter; gonidia spherical, 104 in diameter; colonies
firm, globular pellets,. sometimes several adhering together;
Uisulllys Price AriOUS eee se oe N. pruniforme
9. Colonial mass membranaceous, expanded (although at first form-
ing elopuinr wiaSses)- = ee N. commune
OuColonialamassimotanembranacecous 10
10. Cells cylindrical; constricted at the end walls, which are truncate;
gonidia ellipsoid to cylindric, 6-74 in diameter, 6—14u long N. ellipsosporum
10. Cells barrel-shaped, short; gonidia oval,
niin ie Lens ir powON Gc Asso es see oe N. sphaericum
11. Trichomes densely entangled, filamentous
arrangement not clearly discernible —______________----------- N. punctiforme
11. Trichomes not so densely entangled that the filamentous arrange-
fHent is not easily discernible es 12
12. Plants terrestrial; individual sheaths apparent; cells rather large,
5—8u in diameter; gonidia 6—7u in diameter, 10-154 long _N. microscopicum
12. Plants aquatic; individual sheaths not apparent; vegetative cells
averagine smaller thanvaboye = so) ss iens eee ee 13
13. Colonies when old forming irregularly expanded, gelatinous, free-
floating masses; cells cylindrical, 3.5-44 in diameter; hetero-
Gystsr@vaterOr ODO tees ee ee N. carneum
1oer@ells not acyuund ni call see nen Serene ee ee 14
14. Trichomes densely and compactly entangled;
gonidia/@—7 41m) diameter, (Op long. eae a N. Linckia
14, drichomes not. densely, entangled 15
15. Cells of various shapes within the same trichome, globose to elon-
gate and barrel-shaped; heterocysts globose or oblong, slightly
larger\than'the vegetative cells. 3 N. spongiaeforme
15. Cells all spherical or compressed-globose; heterocysts globose,
larger, up to twice the size of the vegetative cellsave Vos? N. comminutum
Nostoc caeruleum Lyngbye 1819, p. 201
Pig) Bigs, LOo
Colony spherical, planktonic, 5-10 mm. in diameter, appearing as
bright, sky-blue globules dispersed through quiet water; colonial
sheath firm and tough; trichomes densely entangled; cells sub-
spherical or barrel-shaped, 5-7 in diameter; heterocysts frequent,
subglobose or spherical, 8-104 in diameter; gonidia apparently
never described.
Rather uncommon in plankton of lakes with eutrophic character-
istics. Mich., Wis.
Nostoc carneum C., A. Agardh 1824, p. 22
Pl. 119, Fig. 9 (showing an atypical form )
Colony olive-green or blue-green, globular, becoming irregularly
lobed in age and finally expanded soft to firm; trichomes twisted
and entangled but not crowded. Cells subglobose to short-cylindric,
sometimes twice as long as wide, 3-4 in diameter, 6-8p long; con-
stricted at the cross walls. Heterocysts ovate, 6-7 in diameter, 8p
long. Gonidia ovate to oblong, 6-7» in diameter, 8-10, long.
On the bottom, and floating at the surface of quiet water; forming
soft gelatinous expansions when old but retaining a firm tegument.
Wis.
Nostoc comminutum Kuetzing 1849-1869, Tab. Phyc., 2, p. 3
Pl. 119, Fig. 12
Colony an irregularly lobed and membranaceous mass, golden-
brown in color, the investing mucilage soft but retaining a definite
shape when removed from the water. Trichomes twisted or some-
what entangled. Cells globose or compressed-globose; 3.7-4. in
[ 522 ]
diameter, 3-4, long; either adjoined or separated (in different parts
of the colony). Heterocysts spherical, 6. in diameter. Gonidia not
observed (unknown ?).
Tychoplankter; also found on bottom in shallow water. Mich., Wis.
Nostoc commune Vaucher 1903, p. 222
Pl V19 3 Biggs
Plant at first a brown, globular, firm, gelatinous mass, later,
especially when growing on moist soil, becoming expanded; lobed
and clathrate; forming tough leathery layers of considerable extent
(20 cm. wide). Trichomes closely entangled and intertwined, espe-
cially compact in the outer, brown, layer, less so in the colorless,
softer, inner region of the colony. Cells subglobose or barrel-shaped
4-6 in diameter, 7» long; constricted at the cross walls. Heterocysts
frequent, spherical, 7-8.4» in diameter. Gonidia the same shape and
about the same size as the vegetative cells.
On the bottom and on submerged objects; collected from depth of
20 feet in soft water lakes; on damp soil at the margin of lakes and
swamps. Mich., Wis.
Nostoc ellipsosporum (Desmaz. ) Rabenhorst 1865, Vol. 2, p. 169
Plant mass reddish-brown, irregularly globular. Trichomes loosely
entangled. Cells subcylindric to cylindric; 4p in diameter, 6-14p
long; constricted at the cross walls, which are truncate; cell contents
yellowish or olive. Heterocysts subglobose or oblong, 6-7» in diam-
eter, 6-14, long. Gonidia ellipsoid or cylindric-oblong; 6-8 in
diameter, 14-19, long; with smooth walls.
On grass at margin of lakes; on clay banks. Mich.
Nostoc Linckia (Roth) Bornet & Thuret 1880, p. 86
Pl. 119, Figs. 14-16
Colonies firm and globular when young, becoming irregularly
expanded, clathrate, and membranous, soft in age; blue-green in
color, becoming dirty green. Trichomes much entangled, twisted.
Cells subglobose or barrel-shaped, 3—4.5p in diameter. Heterocysts
subspherical to ovate, 6—7.54 in diameter. Gonidia subglobose;
6—7, in diameter, 7—8» long; with dark, smooth membrane.
Among clots of filamentous algae in hard water lakes; sometimes
on moist earth at margin of lakes. Mich., Wis.
Nostoc microscopicum Carmichael (see Harvey in Hooker 1833, p. 399)
Pl. 120, Figs. 3-5
Colonies minute, blue-green or olive-green, globose or ovoid to
[ 523 |
somewhat irregular. Trichomes relatively loosely entangled in a
colorless mucilage. Cells globose, (4.5)-5-8 in diameter; frequently
not adjoined but loosely arranged in a series. Heterocysts subspher-
ical or ovate, 7.3» in diameter. Gonidia ovate or subspherical, 6-7
in diameter, 10-15, long; with smooth walls. Colony 1-9 mm. in
diameter.
Subaerial or growing on pebbles in running water or floating
and entangled among filamentous algae; common.
Mich., Wis.
Nostoc muscorum C. A. Agardh 1812, p. 44
Pl. 120, Fig. 6
Colony a brown, lumpy or tuberculose membrane, firm and
leathery when growing:on moist soil. Trichomes crowded and much
entangled. Cells variable in shape, subcylindrical, barrel-shaped, or
subglobose; constricted at the cross walls; 3-4 in diameter, 5.4-6.5p
long. Heterocysts globose or compressed-globose, 6-7 in diameter.
Gonidia ovate, in a series, with smooth ochraceous membranes.
Occurring in swamps and in shallow water of lakes, mostly soft
water; common. Mich., Wis.
Nostoc paludosum Kuetzing 1850, p. 1
Pl. 121, Figs. 1-3
Plant a minute, oblong or subspherical colony in which a few
trichomes are loosely or (when young) tightly coiled in a wide and
copious gelatinous investment. Cells barrel-shaped, 3-4 in diameter;
cell contents yellowish or olive-green. Heterocysts ovate, 4-5p in
diameter, 6» long. Gonidia ovate, in short series; with a smooth
membrane; 4—4.5 in diameter, 6-8» long. Colony 1 mm. or less in
diameter.
In ditches and Sphagnum bogs; caught among mosses and mats
_ of filamentous algae. Wis.
Nostoc pruniforme C. A. Agardh 1812, p. 45
Pl. 120, Figs. 7, 8
A spherical or ovate colony of loosely entangled or sometimes
radiating trichomes inclosed in a copious and firm gelatinous matrix;
olive-green when young and changing to a black-olive in age. Cells
spherical or compressed-spherical to barrel-shaped; 4-6-(7.5) in
diameter, 4-7, long; cell contents blue-green or gray-green. Hetero-
cysts globose or compressed-globose, 6-7 in diameter. Gonidia
spherical, about 10» in diameter.
This species is common in hard water lakes and slow-flowing
[ 524 ]
streams, rare on recently inundated soil and on moist earth from
which the water has receded. The colonies often appear as marble-
like bodies scattered over the bottom among submerged. grass,
reeds, etc., sometimes in large numbers so that one can scoop them
in double handfuls. Although the average size is 1-2.5 cm., the
colonies may attain a diameter of 5 cm. Not infrequently they are
mistaken for reptile eggs.
Mich., Wis.
Nostoc punctiforme (Kuetz.) Hariot 1891, p. 31
Pl. 121, Figs. 4,5
A small, usually attached, colony of very compactly entangled
trichomes in a colorless, soft mucilage; the linear arrangement of
the cells frequently not discernible. Cells compressed-globose, 3.2—4p.
in diameter. Heterocysts globose, 4.5—-6y in diameter. Gonidia ovate
or oblong; 5-6, in diameter, 5-8p long.
Attached to large filamentous algae and to leaves and stems of
submerged aquatics in hard water lakes. This species also occurs
as an endophyte or a symbiont with lichens and some cycads. Mich.,
Wis.
Nostoc sphaericum Vaucher 1803, p. 223
Pl. 121, Figs. 6-9
A globose or tubercular, olive-green colony when young, becoming
flattened and somewhat membranous and brown in age; trichomes
densely entangled; cells globose, 4-5y in diameter; heterocysts
spherical, 7.4» in diameter; gonidia solitary or in very short series
(3-4 together), ovate, 5-7 in diameter, 10» long, with a smooth
brown wall.
The colonies become as much as 5-6 cm. wide under favorable
conditions. The species should be compared with N. pruniforme, an
aquatic species, but one which sometimes appears in the same habi-
tats as N. sphaericum.
Growing on soil at the margins of lakes; in marshy places among
grasses; in thalli of Ricciocarpus. Mich., Wis.
Nostoc spongiaeforme C. A. Agardh 1824, p. 22
Pl. 121, Fig. 10
A globular colony of loosely entangled trichomes when young,
becoming lobed, expanded, warty and bullate, especially when grow-
ing on damp soil, the color changing from blue-green to brownish-
green. Cells variable in shape within the same colony, subglobose to
barrel-shaped and cylindrical; 3.4-5p in diameter, 5.4-6.5n long.
Heterocysts ovate to oblong or subglobose, 4.8-8» in diameter, 7.2
[ 525 ]
long. Gonidia oblong or ovate; formed in a series and becoming
loosely arranged; 6-7 in diameter, 8-10, long.
Growing on damp soil in marshy places; near margins of lakes.
Mich., Wis.
Nostoc verrucosum Vaucher 1808, p. 225
Pl. 121, Figs. 11-18
A globular or bullate, verrucose and warty, leathery mass, many
colonies sometimes coalescing to form a large olive-green or brown,
somewhat membranous expansion on soil or on submerged sub-
strates, solid at first but becoming hollow. Trichomes densely en-
tangled, especially in the outer firm layers of the colonial mucilage,
less compact inward; straight and radiating, frequently with indi-
vidual sheaths distinct. Cells compressed-spherical or disc-shaped,
3-4 in diameter, 2.5-4y long. Heterocysts spherical, 6. in diameter.
Gonidia ovate, 5u wide, 7p long.
Growing in 27-85 feet of water in semi-hard water lakes; some-
times large colonies are found floating or washed onto beaches of
lakes; also reported growing on rocks near a waterfall. Mich., Wis.
WOLLEA Bornet & Flahault 1888, p. 223
An attached tubular, saccate-cylindric, gelatinous colony of macro-
scopic size in which unbranched, simple trichomes of ovate or
cylindrical cells lie parallel, their sheaths confluent with the soft
colonial mucilage; heterocysts intercalary, or terminal through vege-
tative fragmentation of the trichome; gonidia ovate, solitary or in
a series, either adjoining the heterocyst or distantly removed from it.
Wollea saccata (Wolle) Bornet & Flahault 1888, p. 223
Pl. 122, Figs. 1, 2
Characteristics as described for the genus. Plant mass irregularly
tubular or bullate, closed at the top, at first attached (usually in
shallow water ), later expanding and forming soft, gelatinous masses
floating at the surface. Trichomes compactly arranged, mostly paral-
lel with the long axis of the colony, not contorted and twisted but
commonly curved. Cells ovate to subcylindric; constricted at the
cross walls; varying in their diameter throughout the length of the
trichome; 3.6—4.2-(5) in diameter, 5-10u long. Heterocysts ovate
to subcylindric; solitary; terminal or intercalary; 4-5p in diameter,
6.5-91 long. Gonidia oblong or subcylindrical, with thin, smooth
walls; usually in a series of 3-5, rarely solitary; either near the hetero-
cysts or distant from them.
This plant, although rare, has wide distribution in the United
[ 526 ]
States (Massachusetts and New Jersey to South Dakota). I have
collected the species in southern Louisiana and in Panama.
Attached to the sandy bottom of lakes in shallow water. Wis.
NODULARIA Mertens, in Jiirgens 1822, Dec. 15, No. 4
A sheathed filament, either solitary among other algae or forming
thin expansions or tufts, aquatic or subaerial, on moist soil; cells
disc-shaped or compressed spheroidal, constricted at the cross walls;
heterocysts similarly compressed, about 14 of the width in length;
gonidia spherical or disc-shaped, occurring in short (sometimes
long ) series, intercalary.
Key to the Species
Filaments 4—6u in diameter; gonidia 6-8» in diameter. N. Harveyana
Filaments 8-12—(18) in diameter; gonidia 12” in diameter... N. spumigena
Nodularia Harveyana (Thw.) Thuret 1875, p. 378
Filaments usually solitary; nearly straight, sometimes flexuous but
not entangled or coiled. Sheaths colorless and thin, usually close
but sometimes diffuent and becoming indistinct. Cells 4-6» in
diameter, 14 the diameter in length or, before division, nearly as
long as broad. Apical cell obtusely conical. Gonidia nearly spherical
or compressed-spheroidal; about 8» in diameter; yellowish-brown
in color.
Tychoplankter; in shallow water. Wis.
Nodularia spumigena Mertens in Jiirgens 1822, Dec. 15, No. 4
P]. 122, Figs. 3-5
Filaments usually entangled and clustered in a loose, gelatinous
mass; sometimes solitary; 8-12, in diameter. Cells disc-shaped, very
much compressed; constricted at the cross walls; 6-7.8-(10)» in
diameter, 5.6 long. Gonidia intercalary but not necessarily near
the heterocysts; 12, in diameter, 8—-9y, long.
Uncommon; found among algae in lakes of especially hard water;
also adhering to the culms of rushes submerged in shallow water.
Wis.
APHANIZOMENON Morren 1838, p. 11
Filamentous; united to form fusiform or plate-like bundles and
flakes of parallel trichomes, which are free-floating. Trichomes
relatively short, tapering very slightly at both ends. Cells quadrate-
[ 527 ]
rectangular, constricted at the cross walls. Heterocysts cylindric,
usually but one (rarely 2) in each trichome. Gonidia cylindrical,
truncate at the apices; only one in each trichome; located in the
median region but not adjacent to the heterocyst.
Aphanizomenon flos-aquae (L.) Ralfs 1850, p. 340
Pl. 122, Figs. 6-8
Trichomes parallel, tapering at both ends; united in bundles or
fiakes to form macroscopic colonies of few or hundreds of plants.
Cells 5-6 in diameter, 8-12 long. Heterocysts oblong or cylindrical,
scattered in the midregion of the trichome; 7» in diameter, 12-20p
long. Gonidia cylindrical; formed near the middle of the trichome
but not adjacent to the heterocyst; 8» in diameter, 60-75y long.
This plant is a frequent component of water blooms and in favor-
able habitats may become super-abundant. Hard water lakes in
which there is a high nitrogen content and an adequate supply of
carbon dioxide, either free or available in half-bound carbonates,
may become biologically unbalanced by excessive growth of this
plant. The cells have pseudovacuoles which permit the trichomes
to float high in the water, where they form sticky masses, that are
sometimes many square feet in extent. Either alone or in accompani-
ment with Microcystis, aeruginosa and Anabaena spiroides, this
plant is not infrequently responsible for oxygen depletion in small
lakes and bays, resulting in great loss of fish. The occurrence of this
species is so consistently related to hard water lakes that it may be
used as an index organism for high pH, and usually a high nitrogen
and carbonate content (especially when the plant appears as a
water bloom). Aphanizomenon flos-aquae is rarely found except in
eutrophic lakes or in polluted, hard water, slow-flowing streams. An
exception to this was found in Rahr Lake, Vilas County, Wisconsin,
where there was a visible, although not abundant, bloom in August,
Rahr Lake is a semi-hard water body with an acid marginal mat.
This species may remain alive all winter in the vegetative state,
sometimes thriving under ice; as with Oscillatoria rubescens, there
is some evidence that such growths bring about depletion of oxygen
in shallow lakes, poorly illuminated because of coverage by ice and
snow. The blue-green algae are poor oxygenators in any case. Also
the gonidia may carry the plant over a period of unfavorable en-
vironmental conditions. Their germination and the relation of the
gonidium to bundle-formation have been carefully studied under
laboratory conditions by Rose (1934).
Mich., Wis.
[ 528 ]
CYLINDROSPERMUM Kuetzing 1843, p. 211
Filaments straight, curved, or loosely entangled, each surrounded
by a soft film of mucilage which is confluent with others, forming
an expanded mass of indefinite shape on soil or on submerged sub-
strates. Heterocysts ovate or ellipsoid, one at either end of the
trichome, or at only one end. Cells cylindric or barrel-shaped and
constricted at the cross walls. Gonidia ovate, ellipsoid, or sub-
cylindric, adjoining the heterocyst, solitary or several in a series
with smooth, punctate, or granular calls; inclosed by a thick, close
sheath.
Key to the Species
1. Conidia ocepering, ina: series:____ >= eae 2
i, Gonidia salitasy: aarely 2: together <= es = es 3
2. Cells 4—5u in diameter; gonidia 8—10u in diameter________ C. catenatum
2. Cells 2.3-3.54 in diameter; gonidia 4—5.5u in diameter______ C. Marchicum
a. Conidia cyludrical or subcylindric-= S20 sss ee ee 4
3. .Gonidia, ellipsnid Or ovate. 6
4. Cells 1.8—2u in diameter; gonidia subcylindric,
Buh Ot Sr rina amMetel ooo. 4. 2-2. Ree ee ee C. minimum
4. Cells larger, 3.8-4.5-(6) in diameter; gonidia
eylindries| og subcylndric.. 3a 5
5. Gonidia cylindrical, with smooth walls._____________________--_-------- C. stagnale
5. Gonidia subcylindric, with roughened, punctate walls__________ C. majus
6. Gonidia with punctate walls when mature_______________---__---_------------------- 7
GsiGonidianwathesmoothwalls:__---- ee sere ee ee 8
ea (GOmiGta Gp line Glam ete Trea C. minutum
i Gonidia 14-3, 1m diameter ee C. majus
8. Cells 2-2.54 in diameter; gonidia 8-94 in diameter________.. C. minutissimum
8%) Cellsvand conigiallarger SS 9
9. Gonidia 9-12» in diameter, 10-20u long —_.-_--_-_-_-__ C. muscicola
9. Gonidia 12—14y in diameter, 20-384 long —_.____-__--_ C. licheniforme
Cylindrospermum catenatum Ralfs 1850, p. 338
Pl. 122, Figs. 9, 10
Filaments united by their confluent mucilage to form dark green
patches on submerged aquatics or on damp soil. Cells rectangular
to short-cylindric; slightly constricted at the cross walls; 4-5y in
diameter, 4-7 long. Heterocysts ovate to ellipsoid, 4-5y in diam-
eter, 4-7» long. Gonidia oblong; formed in a series adjacent to the
heterocysts; with a smooth brownish wall when mature; 8-10» in
diameter, 14-18, long. “
On aquatic vegetation; tychoplanktonic. Mich., Wis.
Cylindrospermum licheniforme (Bory ) Kuetzing 1847, p. 197
Pl. 131, Fig. 14
Filaments entangled and forming an expanse of macroscopic
[ 529 ]
proportions, dark green in color. Cells short cylindric; constricted at
the cross walls; 2.5-4.21 in diameter, 4-5. long. Heterocysts elon-
gate, 5—6y in diameter, 7—-12u long. Gonidia solitary, elongate-
ellipsoid to oblong; the wall thick and smooth; 12—14, in diameter,
20—38, long.
On submerged aquatic plants or on stones which are encrusted
with sediment. Mich., Wis.
Cylindrospermum majus Kuetzing 1843, p. 212
Pl. 122, Figs. 11, 12
Filaments entangled to form dark green mucilaginous patches.
Cells short-cylindric; slightly swollen and constricted at the cross
walls; 3.7-51 in diameter, 4-6. long. Heterocysts elongate, little
larger than the vegetative cells, up to 10u long. Gonidia ellipsoid
to subcylindric, with a roughened and punctate wall; 14.8, in
diameter, 27 long, including the sheath.
In several soft water and acid lakes and pools. Wis.
Cylindrospermum Marchicum Lemmermann 1910, p. 196
Pl. 122, Fig. 13
Filaments entangled, forming small mucilaginous patches. Cells
short-cylindric; slightly constricted at the cross walls; 2.5-3.5 in
diameter, 7.4-8.54 long. Heterocysts ovate to subquadrate-ovate,
2.5-3u in diameter, 3-4 long. Gonidia ovate to subcylindric; in a
catenate series adjoining the heterocyst; with thick smooth walls;
45.5 in diameter, (12)-14.8-16, long.
This plant should be compared with C. catenatum from which it
differs but very slightly, chiefly in size. It was originally described
as a variety of that species.
On moist substrates and on vegetation in shallow water. Wis.
Cylindrospermum minimum G. S. West 1914, p. 1016
Pl. 122, Figs. 14, 15
Filaments solitary, or in small clusters, straight or gracefully
curved; cells rectangular to short cylindric, 1.8-2 in diameter,
1.8-3.54 long; heterocysts subglobose to ellipsoid, 2 in diameter,
2.5—2.7 long; gonidia solitary subcyclindric, 3.5—3.8 in diameter,
8—9p long, with a thick smooth wall.
This species was originally described from high altitudes in the
Andes. Such a record naturally casts doubt on the assignment of
our specimens, but they agree so well with West's description that
the disposition seems justified. I have not seen the type specimens
for comparison.
Rare in tychoplankton. Wis.
[ 530 ]
Cylindrospermum minutissimum Collins 1896, p. 120
Piast} Fig. 13
Filaments loosely entangled, forming a thin blue-green skein.
Vegetative cells quadrate-cylindric; not constricted at the cross
walls; 2-2.5. in diameter, 4-5p long. Heterocysts elongate, 4, in
diameter, 6-8» long. Gonidia solitary or in pairs; ellipsoid; the wall
smooth; 8-9, in diameter, 18-20, long.
On mats of algae in shallow water; tychoplankter. Wis.
Cylindrospermum minutum Wood 1874, p. 39
Filaments much entangled in a mucilaginous expanse; forming
bright blue-green to dark green patches on submerged aquatics;
frequently scattered in minute clusters among other algae. Cells
short-cylindric or slightly swollen, with constrictions at the cross
walls; 3-4, in diameter, 3.5-4.8, long. Heterocysts ovate or sub-
globose, 5-7 in diameter, 7-8, long; hirsute, with long radiating
gelatinous fibrils. Gonidia ovate, 6-7» in diameter, 16-19, long,
with a punctate or granular wall.
Common in several acid or soft water lakes and small ponds.
Mich., Wis.
Cylindrospermum muscicola Kuetzing 1845, p. 173
Pl. 122, Fig. 16
Filaments entangled in a mucous expanse, forming dark green
patches on submerged aquatics (Potamogeton, Elodea, Ceratophy-
llum). Cells quadrate to cylindric; with slight constrictions at the
cross walls; 3.5-5.5p in diameter, 46.5, long. Gonidia broadly ovate;
with thick, smooth wall; 9-12n in diameter, (9)—16-20, long.
A rather common species, occurring mostly in hardwater habitats,
alkaline swamps, and shallow lakes. The broadly ovate gonidia are
characteristic. Mich., Wis.
Cylindrospermum stagnale (Kuetz.) Bornet & Flahault 1888, p. 250
Pl. 122, Figs. 17, 18
Filaments entangled or parallel in a mucilaginous expanse, at-
tached or floating. Trichomes with cells constricted at the cross
walls. Cells slightly swollen, 3.8-4.5-(6) in diameter, 7-13.4u long.
Heterocysts globular or elongate, 6-7 in diameter, 7-16 long.
Gonidia ovate or sybcylindric; with thick, smooth wall, (8)-10-
15-(16) in diameter, 19-21.6-( 40)» long.
This is the most common species of the genus in our collections.
It is found on or among aquatic vegetation such as submerged
mosses, and in shallow water on dead and decaying grasses and
[ 531 ]
culms of rushes. At first the plant mass is attached and spreading
over the substrate, but soon becomes free-floating, forming muci-
laginous flakes.
Mich., Wis.
Cylindrospermum stagnale var. angustum G. M. Smith 1916, ‘p. 481
Pl. 123, Fig. 1
A form with gonidia smaller than in the typical plant; vegetative
cells 4-4.5 in diameter, 8-10, long; heterocysts 5.5-5.6» in diam-
eter, 7-11 long; gonidia 7-9 in diameter, 18—-25y long.
Benthic and tychoplanktonic. Wis.
AULOSIRA Kirchner 1878, p. 238
Trichomes solitary or loosely clustered in small bundles, inclosed
in a thin but definite sheath which is closed at the ends. Trichomes
the same diameter throughout or narrowed in the midregion and
larger toward the apices. Vegetative cells rectangular to short-
cylindric, or somewhat barrel-shaped. Heterocysts intercalary;
round, ovate, or subcylindric. Gonidia 1 to several in a series, some-
times adjacent to the heterocysts.
Aulosira laxa Kirchner 1878, p. 238
Pl. 123, Figs. 2,3
Filaments straight or slightly curved; 8» wide; usually solitary
but sometimes in 2’s or 3’s, entangled and parallel, with thin, color-
less, and close sheaths which are somewhat diffluent and not lamel-
late. Cells short and discoid or as long as wide (rarely a little
longer); 6-7.2» in diameter, 3-8 long; much constricted and often
not adjoined at the cross walls; sometimes forming a double series
for a short distance in the sheath. Heterocysts quadrate to angular-
globose, 7.5, in diameter. Gonidia solitary or in series of 2-3; cylin-
drical with rounded ends; 5-7.5p in diameter, 16-19, long.
Entangled with other algae, forming soft gelatinous expanses on
submerged sticks, etc. Wis.
FAMILY SCYTONEMATACEAE
The chief characteristic of the sheathed plants which comprise
this family is their habit of forming false branches. The filaments
are all uniseriate, but in Desmonema and Diplocoleon (not repre-
sented in our collections), more than one trichome is inclosed by a
single sheath. All the genera except 2 (Plectonema and Spelaeopo-
gon) have heterocysts. These determine the point of branch devel-
[ 532 ]
opment in some forms, whereas in others the branching occurs
between the heterocysts. The branch arises when hormogonia in
the primary filament proliferate and produce series of cells that
push out laterally through the sheath, often continuing to form
successive branches. Occasionally branches arise in pairs when
adjacent ends of two hormogonia proliferate.
The sheath is usually firm and definite and sometimes lamellate.
It may be colorless or ochraceous. In general, the cells are quadrate
or short-cylindric, although in some species they are somewhat
barrel-shaped and constricted at the cross walls.
Key to the Genera
iPetlcterocysts, wantin SS Plectonema
1. Heterocysts present ____——_________-_-__--_____________-__-—— 2
2. Heterocysts basal (with intercalary heterocysts sometimes also
present; {oy gebavel OUR S2 520s) ee Microchaete
2. Heterocysts all intercalary; false branching frequent ——___________ 3
ey)
. Branches arising in unilateral pairs, about midway between two
heterocysts (sometimes branches at the heterocysts also); sheath
Hsiallydlamellates=ees sete Scytonema
. Branches arising singly, just below a heterocyst or a series of them. 4
4, Filaments aggregated, somewhat radially arranged in a mucilaginous
layer; branching regularly dichotomous; heterocysts solitary Diplonema
4, Filaments solitary or aggregated, sometimes forming free-floating,
cottony tufts; branching irregular; heterocysts solitary or 2-4 in
IS OTIEGS- 4 5:75 tee ae ee as On eee ke eee Tolypothrix
SCYTONEMA C. A. Agardh 1824, p. xxii
A falsely branched, usually thick-sheathed, filament, the false
branches ordinarily developing in pairs (rarely singly) between the
heterocysts (and sometimes also at the heterocysts ); forming wooly
mats or tangled clots. Trichomes solitary within the sheath, forming
hormogonia in the branches. Cells quadrate or short-cylindric.
Heterocysts subglobose or quadrangular-globose. Gonidia rare; glo-
bose or ovate; about the same size as the vegetative cells. Sheaths
sometimes homogeneous but in most species definitely lamellated,
with the layers either parallel or diverging; hyaline or, especially in
the main filament, ochraceous.
This genus should be compared with Tolypothrix. Scytonema
mirabile, for example, seldom forms branches in pairs but singly, as
in Tolypothrix.
ie)
Key to the Species
1. Sheaths very wide, forming lateral, wing-like expansions S. alatum
1. Sheaths not forming wing-like expansions —____--------------—_--------- 2
[ 583 ]
2. Sheaths lamellate, the lamellations diverging ..________ 3
2. Sheaths not lamellate, or with lamellations parallel __.__________-_________ 5
3. Filaments 18-30-—(36) in diameter; cells 6-124 wide... S. myochrous
SaMilamentst smaller’) 110i 22 Sere ee ee ee 4
4
. Forming free-floating clots with filaments more or less radiating
from a common center, 10-15 in diameter_______________- S. tolypothricoides
4, Forming attached, wooly expanses; filaments 15-214 in diameter__S. mirabile
5. Cells very short, about 1% their width in length; filaments very
coarse and wiry, seldom branching. __- = S. crispum
5: (Cells longer; branching) frequent= = ee S55 aft dc ec net 6
6. Heterocysts ovate or subglobose; filaments 18—24y in diameter____ S. coactile
6. Heterocysts quadrate to cylindrical; filaments
19 1G usin’ diameters sans eke eel EY a Se ee ee ve S. Archangelii
Scytonema alatum (Carm.) Borzi 1879, p. 378
PI. 123, Figs. 4,5
Filaments forming dark olive-brown, wooly mats or tufts. Branches
of trichomes in pairs between the heterocysts, branches relatively
short. Cells short cylindric or barrel-shaped; 9-15y in diameter,
8-15» long. Heterocysts subglobose, tinged with yellow-brown.
Sheaths wide; much lamellated, with the layers diverging, forming
‘wings’; with decided constrictions here and there, especially at
the heterocysts. Filaments 24-66, in diameter.
Tychoplankter. Mich., Wis.
Scytonema Archangelii Bornet & Flahault 1887, p. 92
Pl. 123, Figs. 6, 7
Filaments in fascicles or tufts, forming brownish or gray mats and
cushions. Trichomes with long, gracefully curved branches arising
singly at the heterocysts, or more commonly in pairs between the
heterocysts. Cells quadrate; without constrictions at the cross walls;
12-18, in diameter, 14-20, long. Heterocysts quadrate or cylindrical;
either colorless or ochraceous. Sheaths thin, close, hyaline. Filaments
12-16, in diameter.
Tychoplanktonic and on shore. Wis.
Scytonema coactile Montagne in Kuetzing 1849, p. 305
Pl. 124, Figs. 1-3
Filaments forming thick, blue-green skeins or film-like expansions.
Trichomes frequently branched, with the solitary habit predominat-
ing; false brenches long and spreading. Cells quadrate or com-
pressed barrel-shaped, 12-18, in diameter, 5.8-7.5. long; cell
contents a deep blue-green or yellow-green, especially in the distal
ends of the branches. Heterocysts scattered and infrequent; olive-
[ 534 ]
brown in color; ovate or subglobose; 15.6 in diameter, 19.5 long.
Sheaths close and firm; colorless or light olive; not lamellate. Fila-
ments 18—23.4 in diameter.
All our specimens of this plant have been collected in Sphagnum
bogs and soft water lakes. Wis.
Scytonema crispum (C. A. Ag.) Bornet 1889, p. 156
[S. cincinnatum Thuret]
Pl. 124, Figs. 4-6
Filaments forming dark brown or gray-brown wooly mats; seldom
branched; coarse and wiry. Trichomes straight or somewhat bent,
not tapering, frequently constricted and forming hormogonia. Cells
very short, disc-like; 14-30. in diameter, 2.4-3 long. Heterocysts
spherical, frequent, olive-green or yellowish, 19. in diameter.
Sheath thick (3.5), firm, brown, not lamellated. Filaments 16-36
(mostly 20-30») in diameter.
Frequent in hard water lakes. Forming tangled, brown clots
among filamentous algae or submerged aquatics. In sections of the
filament which are unbranched and in which no heterocysts occur
the plant has the appearance of a coarse Lyngbya. Wis.
Scytonema mirabile (Dillw.) Bornet 1889, p. 155
[S. figuratum C. A. Agardh]
P]. 124, Figs. 7, 8
Filaments forming brown or dark green wooly tufts, either aquatic
or terrestrial. Trichomes with long, infrequent branches usually
arising singly either at the heterocysts or between heterocysts. Cells
quadrate in the main filaments, cylindrical in the branches; 6-12,
in diameter, 8-14p long. Heterocysts quadrate-globose to cylindric;
about the same size as the vegetative cells. Sheaths thin and close
in the branches, thick and with diverging lamellations in the main
filaments. Filaments 15-20, in diameter.
One of the most common species of Scytonema found in our
region. It occurs in both soft and hard water lakes. Many times
the plants have the appearance of a Tolypothrix, especially in the
habit of branching.
Mich., Wis.
Scytonema myochrous (Dillw.) C. A. Agardh 1812, p. 38
Pl. 124, Fig. 9; Pl. 125, Figs. 1, 2
Filaments forming dark brown turfy or tomentose patches. Tri-
chomes long and flexuous in wide sheaths. Cells quadrate to cylin-
dric in the older portions, disc-shaped or compressed-globose in the
[ 535 ]
distal ends of the branches; 6-12, in diameter, 4-14u, long. Hetero-
cysts quadrangular-globose, yellow-brown in color, the contents
yellow-green, sheaths thick and lamellated, with layers diverging;
brown in color. Filaments 18-36 wide.
This species is recorded frequently from aerial habitats.
On logs and stones; tychoplankter. Mich., Wis.
Scytonema tolypothricoides Kuetzing 1849, p. 307
[S. mirabile var. tolypothricoides (Kuetz.) Lobik 1915, p. 42]
Pl. 123, Figs. 8,9
Filaments forming dark blue-green or brown floating, cottony clots.
Trichomes more or less radiating from a common center; freely
branched, the branches mostly in pairs. Cells quadrate to subcylin-
dric in the older portions, compressed and much shorter than wide
in the branches; 6.8—12, in diameter. Heterocysts quadrate or ovate;
about 10, in diameter. Sheaths wide, lamellate, at first colorless, be-
coming brown or orange colored. Filaments 10-15, in diameter.
Common in the plankton of a variety of lakes, mostly soft water.
Appearing as Tolypothrix-like clots floating among aquatic vegeta-
tion near shore. Mich., Wis.
TOLYPOTHRIX Kuetzing 1843, p. 227
A sheathed, falsely branched trichome; solitary or, more usually,
forming cottony tufts and expansions; the false branches mostly long
and flexuous, arising from just below a heterocyst. Cells quadrate
to cylindric or barrel-shaped, constricted at the cross walls. Hetero-
cysts quadrangular, globose, or subglobose, single or in series.
Sheath firm and thin, or somewhat gelatinous and lamellated.
Gonidia ovate to elliptic, or subglobose; with a thin membrane;
often occurring in a series.
Key to the Species
1. Sheaths thick, about as wide, or wider than
the ‘diameter of the trichome +. ~/2. e ek Se )
1. Sheaths thin, usually close, but lamellated in some; less than the
diameterof the, trichome dm width: Sos 2 eee 3
2. Trichomes 5.5—9y in diameter; cells barrel-shaped;
SHG ALS INO’ SHC Kye! ... - =e ee eee ee S. mesentericum
2. Filamentous arrangement of cells apparent; more elongate branches —_- i}
3. Filaments 40-70 wide; plants mostly aquatic; branches
short. and.: broad :2te= Te 6 te Sar aes eee Dera es Pe he S. mamillosum
3. Filaments 27-371 wide; plants mostly terrestrial;
branches long and curved ——______—_————— S. turfaceum
Stigonema mamillosum (Lyngb.) C. A. Agardh 1824, p. 42
Pl. 130, Figs. 1-3
Filaments much-branched, forming attached, dark green wooly
tufts, or scattered in small entanglements among other floating
algae, composed of several series of globose or ellipsoid cells;
branches short, irregularly developing, narrowed at both the base
and in the distal region; heterocysts numerous, compressed-ovate,
cut off laterally from the vegetative cells; sheath wide, lamellate,
becoming yellowish or olive-brown in age; cells 14-17, in diameter;
filaments 40-70» wide; hormogonia developing in special short
branches.
Our collections have all been made from soft water habitats.
Common in several lakes, usually attached to submerged wood;
sometimes forming small clots among floating algae. Mich., Wis.
[ 547 J
Stigonema mesentericum Geitler 1925a, p. 184
Pl. 130, Fig. 4
A gelatinous, cushion-like mass, composed of filaments with very
short, broad, irregularly developed branches in which series of glo-
bose or ovate cells are arranged without definite order; heterocysts
compressed globose, intercalary or lateral; cells 6-12 in diameter;
sheath close, thick and lamellate, inclosing small groups of cells
which form irregular lobes from the main axis; filaments 25-35
wide.
Tychoplankter; in semi-hard water lakes. Wis.
Stigonema ocellatum (Dillw.) Thuret 1875, p: 380
[Incl. S. tomentosum (Kuetz.) Hieronymus 1895, p- 166]
Pl. 130, Figs. 5, 6
Filaments forming brown tufts or cottony masses, with long, nar-
row and curved branches; trichomes partly uniseriate; heterocysts
mostly lateral; cells quadrate-globose to globose, with intercellular
connections, 20-30, in diameter in the principal filament, each cell
inclosed by a conspicuous individual sheath which is either colorless
or brown; cell contents blue- or olive-green to bright marine-green in
the young cells of the branches; sheath wide and lamellated, brown
in the older parts, colorless in the branches; filaments 35—45y wide.
Stigonema ocellatum is a very common species, appearing in a
great variety of fresh-water and aerial habitats. It is often a con-
spicuous component of the algal flora in habitats where desmids
abound, forming brown wooly mats on and over submerged aquatics
such as the culms of Scirpus, Utricularia, decaying leaves, etc.
This is the only common species of Stigonema which has but one
series of cells in the filament (rarely showing a double series for
short distances).
Mich., Wis.
Stigonema turfaceum (Berkeley ) Cooke 1884, p. 272
Pl]. 129, Fig. 5
Filaments much-branched, forming dark-colored, cushion-like
masses, the branches about the same diameter as the principal
filaments, long and curved, with hormogonia produced distally;
trichomes of from 2-4 series of globose or much compressed-
globose cells which in the hormogonia are 12, in diameter; hetero-
cysts intercalary or lateral, much compressed; sheaths wide, lamel-
late and yellow-brown in age; filaments 27-37,» in diameter.
Tychoplankter. Mich., Wis.
[ 548 ]
FISCHERELLA (Bornet & Flahault ) Gomont 1895, p. 52
A branched and sheathed filament with a stouter, prostrate portion
giving rise to vertically elongate, much narrower, curved or straight
branches in which 1 or more hormogonia are formed; cells sub-
globose, quadrate, or cylindrical, usually loosely arranged in 1 to
several series in the principal filament, in a single series only in the
branches; hormogonia with cells closely adjoined and usually in-
creasing in diameter toward the apices; heterocysts globose, barrel-
shaped, or quadrate; sheaths either colorless or brownish, homo-
geneous or lamellated.
This genus is considered by some to be unseparable from Stigo-
nema and is, therefore, often included with it as a subgenus. When
given genus rank it is differentiated principally by the unilateral
arrangement of the branches, which are distinctly smaller than the
main filament, and also by the habit of forming hormogonia in
the apices of the branches.
Key to the Species
Main vfilament mostly, wiiserates = 2s. ee F. ambigua
IM avin, dillewanverne Tentillawerneyey F. muscicola
Fischerella ambigua (Naeg.) Gomont 1895, p. 49
Plant mass consisting of prostrate mats of interwoven filaments
from which vertical fascicles arise; filaments 6-9, in diameter,
giving rise to unilateral branches, which are grouped; sheaths
colorless when young, becoming brownish; cells 2-3 in diameter,
ovate or subglobular to quadrate in the main axis, rectangular in
the branches, 4-6 times longer than wide; heterocysts cylindrical.
On moist soil. Mich.
Fischerella muscicola ( Borzi) Gomont 1895, p. 52
Pl. 130, Figs. 7, 8
Plant mass consisting of prostrate, irregularly spreading filaments,
containing several series of cells, from which mostly unilateral and
uniseriate branches arise; cells quadrate or subglobose in the main
axis; branches 4—6y in diameter, developing hormogonia up to 100
in length; heterocysts globular or barrel-shaped, about the size of
the vegetative cells; sheaths colorless or brownish, without lamella-
tions; filaments 10-14, in diameter.
In shallow water at the margin of ponds among filamentous algae
and larger vegetation. Mich., Wis.
[ 549 ]
FAMILY RIVULARIACEAE
The outstanding characteristic of plants belonging to this family
is the pronounced tapering of the trichomes, which exhibit a distinct
basal-distal differentiation. The sheath is firm, at least in the basal
portion, and may be lamellate or homogeneous. There may be one
or more trichomes within the sheath. In most forms there is a basal
heterocyst or a short series of them (and rarely intercalary hetero-
cysts as well), whereas in 2 genera some species are without hetero-
cysts. The trichomes may be solitary or they may form colonial
aggregates of spherical or hemispherical shape, or the thalli may be
amorphous. In most forms there is an evident false branching which
occurs immediately below an intercalary heterocyst. In at least one
genus the branches lie semiparallel with the original trichome in
the same sheath for some distance before they emerge. Branches may
arise also by in situ proliferation of hormogonia. The presence or
absence of gonidia is of taxonomic interest. These, if present, are
adjacent to the heterocysts.
Key to the Genera
1, Filaments numerous, closely arranged in radiate or parallel series
within copious mucilage to form globular or hemispherical, free-
floating worgattachedsecolonies= 1 sler es aes ae eee 2
PSbilamentsy arranged | otherwise ase sees orale eee eee oy eee Eee ee 8
2. Mucilage firm, often hard and lime-encrusted; akinetes not present;
tnichomies often sparallel) compacted. 2) emer ee ee Rivularia
2. Mucilage soft (especially when the plants are mature); akinetes
present; trichomes radiately arranged ________»__ Gloeotrichia (in part)
3. Trichomes contained in amorphous gelatinous mucilage; attached
orgitee-Moating tes. Ate ce et! xn ee ee pak oe a ee mere eal 5
3. Trichomes not contained in amorphous mucilage; more or less
solitary, or forming plant masses of definite shape 4
4, Colonial mass small, saccate and torn, with the investing mucilage
lamellatetand! much folded’) 8 eee Sacconema
4. Colonial mass otherwise, large and expanded, at first attached, later
free-floating, mucilage not lamellate or folded ___ Gloeotrichia (in part)
BAlkimetes! salosen ies 28 20's ne Aaa § NGA) Se) teks te Pa 6
Dapakcinetes presents... = 4 eas 2 ot LE 5 ee Ld 7
6. Trichomes many, arising from a basal pseudoparenchymatous
poron efithe: thalluss 26s se. CRAs a ee ee Amphithrix
6. Trichomes few together, not arising from a basal pseudoparenchy-
miatousgthalllysy omnes. he sorties es). nist pee ee Calothrix (in part )
7. Filaments freely branched, the branches inclosed within the sheath
of the primary filament, forming dichotomously branched tufts;
NOL TAepipiay tucbeesee whe eee Ses Cele tse te ee ree! Dichothrix
7. Filaments seldom branched; solitary or gregarious, sometimes form-
ing stellate tufts; plants epiphytic on walls of other algae or inclosed
in colonial mucilage; forming encrustations in
aerialvhabitatse: sei tae ey bes oD Calothrix (in part)
AMPHITHRIX Kuetzing 1843, p. 220
Thallus composed of erect, parallel, tapering trichomes from a
basal pseudoparenchymatous tangle of closely appressed trichomes;
heterocysts and akinetes wanting; plant mass often purplish.
Amphithrix janthina ( Mont.) Bornet & Flahault 1886, p. 344
Pl. 131, Fig. 9
Characters as described for the genus; trichomes tapering to a fine,
hair-like extremity, composed of rectangular cells; sheaths thin and
colorless; cells 1.5—2.5u in diameter.
Mich.
CALOTHRIX C. A. Agardh 1824, p. xxiv
‘Trichomes tapering from basal heterocyst (rarely wanting) to a
fine point in most species, abruptly ending in others. In some species
the lower part of the trichome is cylindrical, only the apical region
tapering. Vegetative cells shorter than wide below, longer than wide
toward the apices; heterocysts subglobose or hemispherical, basal
but sometimes intercalary also; gonidia (akinetes) often present, 1
or more in a series, adjacent to the basal heterocyst; sheaths firm,
close, either homogeneous or lamellated, but not flaring away from
the trichome (see Calothrix adscendens); filaments usually simple,
sometimes with false branches from the midregion; plants either
solitary or clustered to form stellate tufts, the basal portion of the
plant lying approximately parallel with the substrate and then bend-
ing away at a sharp angle (in most species); either epiphytic or
endophytic (in the mucilage of other algae), growing on submerged
or on exposed and moist rock surfaces, where extensive patches may
be produced, sometimes becoming encrusted with lime.
Key to the Species
i: Akinetes present ee C. stagnalis
iN eeeAtlcrnetecst a seers Gi nee oe a eA sc EB ee 2
2, Filaments definitely enlarged in the basal portion; sheaths some-
ELMS LN MALeCs CONV A sect ete ae te te a ee 8
2. Filaments very gradually tapering, or cylindrical throughout much
of their length and then tapering ——------—-----________________-----_-- 5
3. Filaments compactly arranged in common mucilage, forming a
colonial expanse on aquatic substrates ___—_-_------_--________. C. Braunii
3. Filaments solitary, or in small tufts, intermingled among other
algae, or epiphytic____________-— 4
4. Sheath close, without lamellations; scattered among
Otherralpae == =e C. stellaris
4. Sheath wide, lamellated; plants attached in the mucilage
Of other alee oo C. fusca
[ 551 ]
5. Trichomes not tapering to a hair; short, abruptly ending C. atricha
5. Trichomes decidedly tapering, sometimes to a long hair 6
6. Filaments associated to form a colonial expanse C. parietana
6. Filaments solitary, or few together, scattered or epiphytic 7
7. Cells very short, 4-45 as long as wide; sheath brown _____C. breviarticulata
i Cellsslonger-psheathycolorless\-- == = aan ED eee eee 8
8. Trichomes slender, 3.5-4u in diameter at the base; filaments
DHRC ATE LEH. so ee teks Uh SOE: Sy eae URI ae Me cere C. epiphytica
8. Trichomes stouter, 12u in diameter at the base; filaments
S24 evimiwdiameteyse sb.) ot Laces) Oe Saget eaace eth See ee) C. adscendens
Calothrix adscendens (Naeg.) Bornet & Flahault 1886, p. 365
Pl. 130, Figs. 9-11
Filaments solitary or in small clusters, tapering from the base to
apex, sheath wide, lamellated; heterocysts basal, 11, in diameter,
11.8, long; vegetative cells 9.24 in diameter, 7.4-8, long at the base;
filament 12-18—( 24) wide at base.
Attached to larger filamentous algae and other aquatic plants. Wis.
Calothrix atricha Frémy 1930, p. 261
Pl. 129, Fig. 6
Trichomes short, solitary or in clusters of 3-4, curved and torulose,
sheaths thin, colorless, not lamellated, slightly tapering to a blunt
apical cell; heterocysts basal, usually in pairs, spherical, 9» in
diameter; vegetative cells 7.4-81 in diameter at the base, 1-14
times as long as wide.
Our plants are questionably assigned to this species originally
described from Africa. The torulose character of the filaments and
the shape of the cells, together with the characteristics of the sheath
and the form of the apical region of the trichome, agree with the
description.
Wis.
Calothrix Braunii Bornet & Flahault 1886, p. 368
PI. 181, Fig. 12
Trichomes parallel, gradually tapering to a point, compactly
arranged to form a colonial expanse on submerged substrates;
sheath thin and colorless; heterocysts hemispherical, basal; vegeta-
tive cells shorter than broad or about as long, constricted at the
cross walls, 6-7» in diameter at the base.
On submerged vegetation and stones in hard water lakes. Wis.
Calothrix breviarticulata West & West 1897, p. 240
PIP 132, Fig.l
Filaments mostly solitary, tapering gradually from a broad base
[ 552 ]
to a long hair, 16, in diameter; sheaths thick, lamellate, discolored
in age; heterocysts basal, hemispherical, 12» in diameter; cells
11-14, in diameter, very short, 145-14 as long as wide, contents
blue-green.
Attached to larger filamentous algae. Wis.
Calothrix epiphytica West & West 1897, p. 240
Pl. 132, Figs. 2,3
Filaments either single or in small clusters, gradually tapering
from base to apex, ending in a long hair; 5-7.5-(7.8) in diameter;
sheaths wide, not lamellate; heterocysts basal, 4-5» in diameter;
cells 4-5 in diameter at the base of the trichome, about as wide
as long.
On filamentous algae and submerged aquatics. Mich., Wis.
Calothrix fusca (Kuetz.) Bornet & Flahault 1886, p. 364
Pl. 132, Figs. 4,5
Filaments strongly curved from short horizontal basal portions,
attached in the mucilage of other algae, bulbous at the base, 11-14y
in diameter, tapering to a long hair; vegetative cells 7—llp in
diameter, 14 as long as wide; heterocysts basal, hemispherical, 9-10
in diameter.
Attached in the mucilage of Coleochaete, Batrachospermum, and
other algae inclosed in mucilage. Wis.
Calothrix parietana (Naeg.) Thuret 1875, p. 381
Pl. 132, Fig. 6
Trichomes solitary or gregarious, forming dark brown patches on
submerged substrates or in aerial habitats, tapering from the base,
much twisted and contorted, with the basal portion of the trichome
appressed on the substrate; vegetative cells very short, 5-10» in
diameter, 2.53» long; heterocysts 6-10 in diameter, usually basal,
quadrate-globose to hemispherical; sheaths firm, relatively thick
and close, not lamellated, becoming yellowish-brown with age;
filaments 10-12» wide.
Attached to old logs and stones in running water; tychoplankton.
Mich., Wis.
Calothrix stagnalis Gomont 1895a, p. 197
PIMS2, Figs?
Filaments usually gregarious in stellate clusters or tufts, rarely
solitary, appressed to the substrate in the basal region but bent
sharply or twisted to form an erect apical portion; trichomes tapering
[ 553 ]
gradually to a hair-like point from a basal heterocyst; cells short,
rectangular to slightly swollen, with constrictions at the cross walls,
5-9 in diameter, shorter than wide below, becoming longer than
wide in the apical region; heterocyst spherical or subspherical,
basal, solitary or in pairs, 6-lly in diameter; sheaths thin, firm,
gradually narrowed with the trichomes; gonidia 1-3 in series,
adjacent to the heterocyst, 10.8 in diameter, 14-16, long; filament
8—(9)-10-(11), wide at the base.
Common; attached to large filamentous algae such as Cladophora,
Rhizoclonium, and Oedogonium. Mich., Wis.
Calothrix stellaris Bornet & Flahault 1886, p. 365
Filaments solitary or clustered and radiately arranged, bent from
the basal swollen portion and tapering to a fine hair from a hemi-
spherical, basal heterocyst; sheaths thin, firm and close, colorless;
cells 6-7 in diameter, constricted at the cross walls, 14-14 times as
long as broad; heterocysts either solitary or in a series of 2-3;
filaments 15-21, in diameter at the base.
Attached to submerged plants. Wis.
DICHOTHRIX Zanardini 1858, p. 297
In this genus the plant is composed of 2-6 tapering trichomes
inclosed within a single sheath for at least a part of their length.
They are usually solitary but sometimes form macroscopic, cushion-
like masses or feathery tufts on submerged wood and stones, or on
moist substrates; trichomes with basal heterocysts (sometimes inter-
calary also), and with dichotomous false branching, a branch ex-
tending for some distance within the same sheath as the principal
trichome, then emerging in its own sheath and usually rebranching
successively; cells quadrate, slightly swollen, or shorter or longer
than their diameter, either constricted or not at the cross walls;
tapering at least in the distal portion of the trichome; basal hetero-
cysts connate or hemispherical; sheaths either thin and close or
lamellated, sometimes with a bulbous base, tapering with the
trichome or widely diverging toward the apex to form a funnel,
according to the species.
Key to the Species
1. Filaments 10—14, in diameter, with flexuous,
Spread Gan cedlarattchesmm ee wrote ree cok x; voces Les hee ceen nese CMe en eee D. Orsiniana
1. Filaments larger, with straight or curved branches .......................00.c0000--. 2
2. Filaments coarse, 20—28u in diameter; branches bulbous
at thet basca, pies Mem ne Maen kde Ee Ma a ca D. Hosfordii
2. Filaments narrower, (12)—15—18u in diameter;
branches not’ bulbous’ atsthe base. .)s). scene ee D. gypsophila
Dichothrix gypsophila (Kuetz.) Bornet & Flahault 1886, p. 377
Pl. 133, Figs. 1, 2
Either solitary among other algae or forming tufts and expanded
strata, frequently encrusted with calcium carbonate; filaments re-
peatedly branched, the branches parallel with the principal trichome
and inclosed in the same sheath with it for a considerable distance;
vegetative cells shorter than wide at the base and with convex walls,
longer than wide toward the distal end and cylindrical without
constrictions at the cross walls, 6-8, in diameter in the basal portion
of the trichome; heterocysts subglobose or hemispherical, 10-12y
in diameter; sheaths lamellated, at first close, then becoming funnel-
shaped toward the distal end; filament (12)-15-18p wide at the
base; penicillate tufts as long as 2 mm.
This species varies in its sheath characters, apparently, for authen-
tically named material which was compared with Wisconsin plants
shows both close, tapering sheaths as well as flaring, funnel-forming
sheaths. It should be compared with D. Hosfordii, a much larger
plant with sheaths bulbous at the base.
Forming tufts of filaments entangled among other filamentous
algae in shallow water at the margin of marshy lakes. Wis.
Dichothrix Hosfordii (Wolle) Bornet in Setchell 1896a, p. 190
Pl. 133, Figs. 3, 4
Plants penicillate tufts of stout, dichotomously branched filaments,
90-28 in diameter at the base; vegetative cells much shorter than
their diameter, 10-15, in diameter at the base, 3-5p long, becoming
cylindrical and several times their width in length in the distal
region, which tapers to a hair-like point; heterocyst a short, broad
cone, or hemispherical, olive or blue-green, 15-18 in diameter;
sheaths lamellated and bulbous at the base, several trichomes within
a sheath, the branches appressed for some distance, then emerging
in their own sheath.
This species is more common in our collections than D. gypsophila.
It occurs among other algae in a number of both hard and soft
water lakes. The greater size and the bulbous-inflated sheaths help
to identify it. Mich., Wis.
Dichothrix Orsiniana (Kuetz.) Bornet & Flahault 1886, p. 376
Pl. 133, Figs. 5, 6
Gelatinous, penicillate tufts, composed of slender trichomes in
close and thick, lamellated, tapering sheaths; filaments branching
freely, the branches extending for most of their length within the
sheath of the principal trichome; trichomes subcylindric below,
[ 555 ]
tapering to a fine point distally; vegetative cells very short, 5-8
in diameter, 2-4, long, or quadrate; heterocysts subglobose or
hemispherical, 8-10, in diameter; filaments 10-14, wide at the base.
On moist earth or attached to or entangled among filamentous
algae. Mich., Wis.
RIVULARIA (Roth) C. A. Agardh 1824, p. 19
Filaments semiparallel or radiately arranged in copious, very
firm mucilage, forming either semi-microscopic globose colonies or
macroscopic, bullate or expanded masses which may be either solid
or hollow; heterocysts all basal and the trichome tapering from
them to fine points; frequently branched, the branches sometimes so
disposed as to form transverse zones through the colonial mass;
individual sheaths definite at the base but becoming diffluent toward
the apex of the filament; gonidia lacking.
Key to the Species
Cells 4—7.5u in diameter; colonies lime encrusted... R. haematites
Cells 9-12.5y in diameter; colonies not conspicuously lime encrusted..R. minutula
Rivularia haematites (D. C.) C. A. Agardh 1824, p. 26
Pl. 131, Figs. 10, 11
Filaments united in attached, hemispherical colonies, inclosed by
a firm mucilage and encrusted with lime, colonies frequently gre-
garious and agglutinated to form an expanse as much as 8 cm.
thick; filaments closely arranged and semiparallel, the false branches
forming transverse tiers or zones; individual sheaths conspicuous
below, firm and close, either colorless or yellow, becoming expanded
and funnel-form above toward the periphery of the colony; cells
4-7.5u in diameter, twice the diameter in length in the lower part
of the trichome, becoming 14 as long as wide in the apical region.
On stones in lakes and flowing water. Mich.
Rivularia minutula (Kuetz.) Bornet & Flahault 1886, p. 348
Pl. 136, Fig. 9
Filaments arranged in brownish, globular or hemispherical
colonies, enclosed in firm mucilage, but rather loosely and radiately
arranged within the colony and inclosed in wide, hyaline or brown-
ish, lamellate sheaths, becoming funnel-form toward the periphery
of the colony; trichomes tapering to a stout hair above from oblong
or hemispherical heterocysts; cells 9-12.5 in diameter, quadrate
below, becoming 3-4 times as long as wide in the apical region.
Attached to submerged plants and wood. Mich.
[ 556 j
GLOEOTRICHIA J. G. Agardh 1842, p. 8
A free-floating or attached hemispherical or globose colony of
radiating trichomes, tapering from basal heterocysts and much
attenuated at the apices; colonial mucilage soft or rather firm
according to species (but not rubbery and not so tough as in the
genus Rivularia), either colorless or becoming ochraceous with age
in some species; sheath of the trichome usually confluent but often
evident in the basal part of the trichome; heterocysts solitary (rarely
2), basal as well as intercalary, globose to oval; vegetative cells
short in the basal portion of the trichome but becoming barrel-
shaped, longer and cylindrical distally; gonidia cylindrical, usually
single, adjoining the heterocyst, rarely in a short series, the mem-
brane thick and smooth.
Species of Gloeotrichia are included with Rivularia by some
authors. Separation is here arbitrarily made on the presence of the
gonidia, Rivularia lacking them. The latter genus includes species
which are always attached and which have very firm, sometimes
hard mucilage, often encrusted with lime. The hemispherical col-
onies of both genera are macroscopic in size and similar in general
appearance. In Rivularia the colony may be hollow, and the radiat-
ing filaments are in concentric zones as a result of false branching.
In some species of Rivularia agglutinated and expanded gelatinous
attached masses are formed. In Gloeotrichia the colonial mucilage
is softer and the trichomes definitely radiate and not zoned. Branch-
ing is less common. Whereas some Gloeotrichia may remain attached,
most species become planktonic or free-floating, especially G.
echinulata and G. natans.
Key to the Species
ae iGolonies elobular, planktonic... et ts G. echinulata
1. Colonies not planktonic or, if free-floating, not globular and burr-like____ 2
2. Colonies containing only a few trichomes; cells very long and
cylindrical, rounded at the ends; a conspicuous granule at each
GTOSSiavy alll fis Bit 2) eG Seay aa et oh Li Sao all G. longiarticulata
2. Colonies containing numerous trichomes; cells quadrate or
slightly longer than wide, or shorter than wide in the basal
portion; end walls not rounded or marked by conspicuous granules___ 3
3. Colonies globular or hemispherical, 1-5 mm. in diameter; attached,
sometimes completely coating aquatic plants G. Pisum
3. Colonies irregularly globose or bullate, 5 mm. to 10 cm. across,
becoming soft and irregularly expanded and floating when old___ G. natans
Gloeotrichia echinulata (J. E. Smith) P. Richter 1894, p. 31
Pl. 134, Figs. 1, 2
A free-floating, spherical, gelatinous colony of many sheathed
[ 557 ]
trichomes radiating from a common center; trichomes tapering from
a basal heterocyst to a fine hair-like point extending beyond the
limits of the colonial mucilage and so giving a burr-like appearance;
cells spherical or barrel-shaped at the base of the trichome, 8-10u
in diameter, becoming long and cylindrical in the distal portion;
cell contents with many pseudovacuoles; heterocysts spherical, 10n
in diameter; gonidia cylindrical, 10-18» in diameter, up to 50y long,
adjacent to the heterocyst; sheaths colorless, wide, without lamella-
tions, covering approximately the lower third of the trichome.
The colonies are macroscopic and appear as minute, dark, egg-
like or burr-like bodies, opaque in the center and translucent at
the periphery. The planktonic habit is associated with the pseudo-
vacuoles, which are often numerous and large. As is well-known,
those blue-green species which have a high degree of vacuolization
show a great buoyancy, often floating at the very surface. Gloeo-
trichia echinulata, like Aphanizomenon flos-aquae and Microcystis
aeruginosa, often forms a dense suspension of thalli in upper lake
levels. Such superabundant growths are frequently followed by
unbalanced biological conditions as a result of the death and decay
of plant masses. During mid-summer and throughout the warm
season Gloeotrichia echinulata makes periodic blooms, sometimes
becoming concentrated near the shore line and in shallow bays in
such numbers as to form a veritable puree.
This species undoubtedly begins its life cycle in a sedentary or
attached condition, developing from gonidia of the previous genera-
tion. The mechanics involved in the germination which determines
the filament arrangement, the soft consistency of the colonial muci-
lage, and the volume of the cell contents occupied by pseudovacuoles
no doubt are responsible for the ready adoption of the planktonic
habit. Hence conspicuous growths make a sudden appearance in
lake plankton when large numbers of colonies become free-floating.
Wind and water currents and probably a change in physiology also
act to bring about a scattering and vertical distribution so that a
dense surface bloom may disappear as quickly as it developed.
Common in the plankton of many lakes, especially in hard water
habitats. Mich., Wis.
PGloeotrichia longiarticulata G. S. West 1907, p. 183
Pl. 134, Figs. 8-5
Thallus hemispherical and attached, containing relatively few,
widely separated, and loosely arranged trichomes which taper to
a very fine point; sheaths confluent with the colonial mucilage; cells
elongate-cylindric with rounded ends, (4.5)-9.5 in diameter, 3-7
[ 558 ]
times the diameter in length (in our specimens, with cells separated
slightly from each other), with a conspicuous granule at each cross
wall, contents not vacuolate; heterocyst subglobose to elongate-
elliptic or ovate; gonidia short-cylindric, 14.81 in diameter, 27.3-
(44) long with a yellowish membrane.
The plant, found but once, is scantily represented in the collec-
tion. The characteristics are distinctive, however, and agree closely
with the description given by West; hence it is tentatively assigned
to Gloeotrichia longiarticulata G. S. West. Subsequent collections
are needed to confirm this identification.
Attached to submerged aquatics. Wis.
Gloeotrichia natans (Hedwig) Rabenhorst 1847, p. 90
Pl. 134, Figs. 6, 7
A soft, gelatinous, globose or bullate, attached colony, brown or
olive-green in color, becoming free-floating and expanded to form
irregularly shaped mucilaginous masses at maturity; filaments at
first somewhat radiate, becoming irregularly arranged and entangled,
very long and tapering from a basal heterocyst; cells barrel-shaped
or subglobose below, becoming quadrate or subcylindrical distally,
7-10, in diameter; heterocysts globose or ovate, 8-12, in diameter;
gonidia solitary, adjacent to the heterocyst, 12-18, in diameter, up
to 250, long, with a thick wall and a sheath; basal sheath of the
filament covering about a third of the length, lamellated, wrinkled,
wide and funnel-shaped above.
This species forms attached colonies as much as 10 cm. across
under favorable conditions (quiet hard water and high tempera-
tures). The mucilage is very soft, and the colonies expand and be-
come floating masses by the time gonidia have reached maturity.
Inasmuch as the plant mass soon fragments, this species is frequently
collected in plankton catches, where it appears as irregular flakes
of entangled filaments. Under such circumstances it may be differ-
entiated from old colonies of Gloeotrichia echinulata by the form
of the sheath, the larger size of the gonidia, and by the greater
length of the flagelliform trichome. At maturity the vegetative cells
dissociate, leaving the spore and the heterocyst adjoined.
Common in many hard or semi-hard water lakes. Mich., Wis.
Gloeotrichia Pisum (C. A. Ag.) Thuret 1875, p. 382
Pl. 134, Figs. 8-10
A firm, mucilaginous, brown or olive-green, globular or hemispher-
ical colony, attached to submerged aquatics; colonies from 1 mm. to
1 cm. in diameter (usually about 5 mm.), composed of compactly
[ 559 ]
arranged filaments radiating from a common center and tapering
from a basal heterocyst to a very fine point; colonial mucilage
bounded by a leathery integument; cells short, barrel-shaped or
quadrate below, becoming cylindrical in the distal portion, 4~7p in
diameter, 8-12 long; heterocysts spherical or ovate, 8-11-(15), in
diameter; gonidia cylindrical with broadly rounding poles, the
membrane thick and sheathed, 10-15, in diameter, up to 400u long.
This species is attached throughout its entire development, rarely
or only incidentally becoming free-floating. In suitable hard water
habitats its brown or olive globular colonies are thickly clustered
and sometimes completely coat over submerged aquatics such as
Potamogeton spp. and Ceratophyllum demersum. Because of the
firm texture of the colonial mucilage and the compact arrangement
of the filaments, the species may be confused easily with Rivularia
when the plants are young, before gonidia have developed.
Common in many hard or semi-hard water lakes and streams.
Mich., Wis.
SACCONEMA Borzi 1882, pp. 282, 298
Colonial mass amorphous or somewhat tubercular, the mucilage
soft and irregularly lobed and folded, and lamellate; trichomes
radiating irregularly, 2 or several within the same sheath, which is
wide, lamellate, and expanded at the extremities; heterocyst and
akinetes basal, the trichome tapering to fine hair-like points; plants
attached to stones and other submerged substrates; one species.
Sacconema rupestre Borzi 1882, pp. 282, 298
Pl. 186, Figs. 1, 2
Characteristics as described for the genus; trichomes 8-10» in
diameter at the base; heterocysts globose or compressed-spheroidal;
akinetes globose, 15 in diameter, with a granulose wall.
On stones from a depth of 20 feet, Douglas Lake, Michigan.
CLASS CHLOROBACTERIACEAE
In this group of the Cyanophyta are classified minute, bacteria-
like organisms of uncertain position which are weakly pigmented.
The cells are spherical or bacilliform and are arranged to form
amorphous, gelatinous colonies in which the cells have no definite
arrangement, or the cells may form false filaments or reticulate
associations. The colonies may vary greatly in size from 4-celled
aggregates to gelatinous masses containing hundreds of individuals.
See p. 36 in connection with chlorophyll tests involving a member
of this class.
[ 560 ]
PELOGLOEA Lauterborn 1913, p. 99
Cells bacilliform, straight or slightly twisted, often knobby and
irregular (in our specimens), solitary or in short linear series;
crowded within an amorphous or irregularly globular gelatinous
matrix.
Pelogloea bacillifera Lauterborn 1917, p. 430
Pl. 104, Figs. 4, 5
Characteristics as described for the genus; cells bacilliform,
straight or curved rods, sometimes elliptic, slightly tapering at the
poles, solitary or 2-3 in linear series; densely crowded in a gela-
tinous, saccate or clathrate mucilage; cells 0.6—-1.54 in diameter,
2-4, long.
When this plant was collected in Scaffold Lake, Wisconsin, it
was so abundant as to color the entire lake, although ordinary
plankton catches failed to disclose the presence of the organism.
It was found that the gelatinous colonies dissociate within the net,
so that individuals or small clumps of cells only occur, these appear-
ing as bacteria. Repeated collections and laboratory culture per-
mitted the determination of the presence of Pelogloea bacillifera
together with Plectonema nostocorum.
Nannoplankter; in semi-hard water lakes; often in tychoplankton
but usually found at great depths; sometimes occurring in a
stratum near the bottom of a lake. Mich., Wis.
[ 561 ]
DIVISION RHODOPHYTA
In this division the cells contain a variety of pigments, chlorophyll,
phycocyanin, and phycoerythrin. The latter, a red pigment, is
usually predominant, especially in the marine forms, but varying
amounts of this and the other pigments produce violet, gray-green,
or blue-green colors. This is especially true for the fresh-water
Rhodophyta which are almost any color except red. The chromato-
phore, usually axial, contains a central pyrenoid which collects
starch as a food reserve. In one of the subgroups the end walls of
the cells have a pore which permits intercellular cytoplasmic con-
nections.
The primary distinguishing characteristics of the division are the
structure of the sex organs, the sexual methods of reproduction, and
the types of life history entailed.
Throughout the division the range of plant forms discloses an
evolutionary series which has counterparts in other algal groups.
There are unicellular, palmelloid, simple and branched filamentous,
and frond-like expressions. In the higher forms there is often found
considerable differentiation among the cells to form what might be
regarded as tissues.
The majority of the Rhodophyta are marine, but a few genera
are either fresh-water or have representatives in inland habitats.
Many of these are found in streams in alpine or subalpine situations.
There are 2 subclasses, the Bangioideae and the Florideae. The
former, which is the more primitive, contains 3 families in fresh
water. The Florideae, a much larger group, includes the majority
of species and is represented by 4 families in fresh water.
CLASS RHODOPHYCEAE
SUBCLASS BANGIOIDEAE
In this group, the fresh-water members possess a thallus which is
a branched or unbranched filament, or a ribbon-like or plate-like
expanse one cell in thickness. The cell walls are thick and gelatinous
and often somewhat lamellate. Unlike some of the Florideae, plants
in this group do not have intercellular protoplasmic connections. The
chromatophore, which is axial and stellate, contains a single pyre-
noid. Pigmentation as described for the division.
Asexual reproduction is by nonmotile spores. In the few known
cases of sexual reproduction, divisions of the vegetative protoplast
[ 562 |
give rise to spermatia which fuse with vegetative cells, after which
reproductive cells known as carpospores are formed.
This subclass contains but a single order, the Bangiales, which
is represented in our region by 2 genera.
ORDER BANGIALES
Characters as described for the subclass. The three families which
comprise this order are the Bangiaceae, in which spores are formed
by divisions of unspecialized vegetative cells, the Erythrotrichiaceae,
in which spores are borne in special sporangia, and the Goniotri-
chaceae, in which spores are simply modified vegetative cells
formed without division of the protoplast. Only the latter family
is represented in our collections.
FAMILY GONIOTRICHACEAE
In this family the plants are simple or branched, pseudofilamentous
thalli. Reproduction occurs as described above, sexual reproduction
being unknown.
ASTEROCYTIS (Thwait.) Gobi 1879, p. 93
Filaments simple or branched, composed of globose or oblong
cells inclosed in broad gelatinous sheaths, arranged in a more or
less irregular uniseriate manner. The cells may be closely arranged,
or at some distance from one another. The chloroplast is axial and
stellate and contains a central, usually conspicuous pyrenoid.
Asterocytis smaragdina (Reinsch) Forti 1907, p. 691
Pl. 135, Fig. 3
Characters as described for the genus; filaments simple or
branched, occasionally somewhat palmeiloid, the branches develop-
ing by a cell slipping to one side of the series and continuing to
divide in another plane; cells 6-11 in diameter, 8-16, long.
Attached to stones and to strands of coarse filamentous algae,
North Trout Lake and Fishtrap Lake, Vilas County, Wisconsin; also
reported (C. E. Allen correspondence) from Lake Mendota, Wis-
consin.
BANGIOIDEAE OF UNCERTAIN POSITION
FAMILY PORPHYRIDACEAE
PORPHYRIDIUM Naegeli 1849, p. 139
Unicellular but with many individuals aggregated to form an
irregularly expanded, thin, gelatinous layer. Cells mostly spherical,
[ 563 ]
with individual gelatinous sheaths and embedded in a common
gelatinous matrix; with dark red, stellate chromatophore and small,
excentric nucleus. Reproduction by cell division. Forming blood-red
film on moist soil and walls, especially in greenhouses.
Porphyridium cruentum Naegeli 1849, p. 139
Pl. 136, Fig. 6
Characters as described for the genus. Size of cells variable:
5-9yn, 7-12, or up to 24y.
On soil in greenhouse, University of Wisconsin, Madison.
SUBCLASS FLORIDEAE
In this advanced group of the red algae the thallus has a multi-
plicity of expressions, ranging from slightly branched filaments to
complex plants of macroscopic size, involving complexes of fila-
ments which may be differentiated to form tissues. Growth in all
these forms occurs by the activity of one or more meristematic
apical cells.
The sex organs, especially the female, are characteristic of the
group. The carpogonium has a definite neck-like extension, the
trichogyne, the shape of which varies in different genera and species
and is, therefore, of taxonomic value. See Smith (1933, 1938) and
Taylor (1937) for a description of morphological characteristics,
methods of reproduction, and outlines of life histories.
ORDER NEMALIONALES
There are four fresh-water families in this order, of which three
have representatives in the Wisconsin collections. The fourth family,
Thoreaceae, undoubtedly is present in the plant Thorea ramosissima
Bory, but as far as known this species has not been reported from
the region. Sexual reproduction involves specialized female sex or-
gans (carpogonia), and antheridia which develop non-motile sper-
matia. In addition to gametangia, the sexual plant may produce
non-motile monospores cut off from the tips of branches, especially
in juvenile stages of development.
FAMILY CHANTRANSIACEAE
In this family the thallus is a filament which has repeated alter-
nate branching and is without a conspicuous central axis.
AUDOUINELLA Bory 1823, p. 340
Thallus consisting of sparingly branched filaments of cylindrical
[ 564 ]
cells from rhizoidal holdfasts, the branches about equal in diameter
to the main filament which more or less becomes lost in the branch-
ings; branches of the second and third order about equal in diameter
to those of the first order; all branches ending in bluntly rounded
apical cells; chromatophores discoid or plate-like bodies, without
pyrenoids; color gray or violet-green; reproduction by monospores
borne singly or in clusters at the ends of short branches. Sexual
reproduction is known for a least one species.
Members of this genus should be compared with juvenile states
of Lemanea and Batrachospermum, especially if Audouinella-like
plants are collected nearby, or with adult stages of other red algae.
Most of the plants previously referred to species of Chantransia
have been assigned to Audouinella or redefined as juvenile stages of
Batrachospermum.
Audouinella violacea (Kuetz.) Hamel 1925, p. 46
Pl. 135, Figs. 1, 2
Plants forming violet-green tufts from horizontal holdfast branches;
filaments sparingly branched; branches scarcely tapering, varying
in length from one cell to as long as the main filament; cells cylin-
drical, with 2-3 plate-like chromatophores which are violet-green
in color and rather metallic in appearance; filaments 8-12y in
diameter.
Attached in flowing water. Wis.
FAMILY BATRACHOSPERMACEAE
In this family the thallus has a definite axis of cells which becomes
corticated by downward growing elements from node regions.
Branches are given off in more or less dense and definite whorls so
that a beaded effect is produced in the macroscopic appearance of
the thallus. Monospores are produced at the ends of branches in
juvenile stages, whereas carpogonia and clusters of antheridial cells
are borne in the adult phase only. The sex organs may be monoecious
or dioecious.
BATRACHOSPERMUM Poth 1797, p. 36
An attached, much branched thallus consisting essentially of an
axial row of large cells which cut off lateral units at definite intervals,
thus determining node and internode regions; from these laterals
a longitudinal investment of cortical filaments develops which more
or less (depending upon the species) completely covers the axial
row; also from the nodal units as well as from the cortical elements
[ 565 ]
themselves, out-turned fascicles of branches develop, those at the
node region forming primary whorls which in many species produce
a distinctly beaded appearance; cells in the axial row cylindrical,
ovoid, ellipsoid, or fusiform in the branches; branching of the fasci-
cles dichotomous, the ultimate branches terminating in short or
long colorless hairs; entire thallus inclosed in a soft amorphous
hyaline mucilage; a single massive chromatophore in each of the
principal cells, and two to five disc-like or irregular chromatophores,
each with a pyrenoid, in each cell of the branches; plant mass gray-
or violet-green or brownish.
In this genus sexual reproduction involves female (carpogonial)
cells and male (antheridial) units. The latter are small, non-motile
cells produced in clusters at the tips of lateral branches. The carpo-
gonium is a flask-like cell with an elongate tip, the trichogyne,
which receives the spermatia. The shape and location of the carpo-
gonium and the form of the trichogyne are specific characters and
are of taxonomic value. The trichogyne may be spatula-shaped,
oblong, or lanceolate. See Kylin (1912), Sirodot (1884), and Skuja
(1931) for a description of sex-organ morphology in this genus.
When reproductive organs are absent, identification of species in
Batrachospermum is practically impossible in most cases, and even
when such organs are present, experienced judgement is often re-
quired to make satisfactory determinations. Although there are
more than five species of Batrachospermum in our collections,
only those are listed here which have been observed in the fruiting
condition. An interesting problem involving the ecology and taxo-
nomy of this genus in this area awaits further studies.
Batrachospermum forms dark gray-green or blue-green masses,
streaming from stones or submerged wood in flowing or standing
water, usually at low temperatures. Some species are less widely
distributed than others and seem to be confined to acid ponds in
Sphagnum bogs, where they produce growths up to 30 cm. in length
on the submerged stems of Chamaedaphne or on overhanging
grasses and sedges. Early in the summer, juvenile or Chantransia-
stages predominate in certain habitats such as stones in flowing
water. In this condition the young plants cover submerged objects
with a blue-green gelatinous film. As mentioned under Audouinella
above, comparison should be made between these juvenile stages
of Batrachospermum and what may appear to be true Audouinella
plants.
Key to the Species
1. Lateral whorls of branches lacking or scarcely developed;
internodes lonpesnees eee VS SE Se eee B. Dillenii
1. Lateral whorls of branches well-developed, crowded; internodes short —__ 2,
[ 566 ]
Peenicnoeyie clavates =... 2 eee ee 4
2. Trichogyne spatula-shaped, ellipsoid, or ovate__-—----------_--_------- 3
Sudmichogyne.spatula-shaped 2 ses eee ae B. vagum
Oo einichosyne ellipsoid Or OVAte se ee ee B. Boryanum
4. Carpospores developed in outer part of a branch-whorl_______ B. ectocarpum
4, Carpospores developed in inner part of branch-whorls in axils of
branchesimean the:madin axis 0". “sth eee B. moniliforme
Batrachospermum Boryanum Sirodot 1884, p. 246
Pl. 136, Fig. 5
Thallus densely branched and embedded in copious mucilage,
gray-green to golden-green in color; whorls conglomerate, usually
closely arranged to form a decided beaded appearance; secondary
branches either few or many; corticating branches many, loosely
arranged; apical hairs few, slightly swollen at the base; dioecious;
carpogonia on a primary lateral branch or rarely on the branches
from the corticating filaments, the trichogyne ellipsoid or oval; carpo-
spore masses numerous, scattered throughout the branch-whorls.
Walnut Lake, Michigan.
Batrachospermum Dillenii Bory 1823, p. 226
Pl. 135, Figs. 4-6
Thallus irregularly and sparingly branched, the branches rather
rigid, straight or slightly curved; plant 2-5 cm. long; cortical fila-
ments highly developed and inclosing the axial filament with a
parenchymatous layer; lateral branching system poorly developed,
the branches short with few repeated branchings, forming nodal
clusters a considerable distance apart so that a jointed appearance
is produced macroscopically; in the apical region the abbreviated
out-turned branches numerous, compactly clustered, composed of
subglobose or ovoid cells and ending in long cylindrical cells but
without terminal setae; plants dioecious, the carpogonia on very
short branches, produced directly from the main axis, not in whorls
of branches, triangular in shape, narrowed above and then slightly
inflated to form a claviform or oblong trichogyne; antheridial cells
formed in transverse zones from short, out-turned branches, many
occurring in ohe cluster.
Scrapings from a log in flowing water. Wis.
Batrachospermum ectocarpum Sirodot 1884, p. 222
Pl. 136, Fig. 4
Thallus much-branched, the whorls of branches well-developed,
lobed and broadly rounded, close together, the internodes short;
inclosed in copious rather firm mucilage, gray- or olive-green, up
[ 567 ]
to 12 cm. long; hairs few or lacking, short with bulbous bases;
corticating branches few or lacking; monoecious; carpogonia on
primary lateral branches in the outer part of branch-whorl, sub-
tended by large cells and numerous lateral branches; trichogyne
clavate.
In Sphagnum bog pools; attached to stones in slowly flowing
water. Mich., Wis.
Batrachospermum moniliforme Roth 1800, p. 450
Pl. 136, Fig. 3
Plants stout, richly branched, with well-developed whorls of
branches presenting a distinct beaded or moniliform appearance
macroscopically; plant mass gray-green, violet-green, or brownish;
plant masses up to 10 cm. long, forming streaming tufts (frequently
in swiftly running water ); inclosed by copious, soft mucilage; plants
annual; monoecious; carpogonia developed in inner part of the
branch-whorls, terminal on short lateral branches in the axils, with
a clavate or lageniform trichogyne; carpospore masses, dense, scat-
tered throughout the plant; branches ending in long setae with a
swollen base.
This is the most common species of the genus in the region. It
often occurs in flowing water, where it may form extensive beds on
stones and gravelly bottoms.
On submerged wood in streams; also in lakes. Mich., Wis.
Batrachospermum vagum (Roth) C. A. Agardh 1824, p. 52
Pl. 135, Figs. 7-11
Plants freely branched, as much as 20 cm. long, forming dark
olive- or gray-green arborescent masses inclosed in copious mucilage
and forming soft, streaming thalli; whorls of branches well-
developed, forming globose nodal masses, the branches composed
of ovoid or ellipsoid-ovoid cells, ending in long hairs; the whorls
quite separated in the lower part of the plant, becoming closer and
coalesced distally; plants monoecious, the branch bearing the carpo-
gonium consisting of 7-14 cells, developing centrally in a whorl of
branches, the carpogonial cell bottle-shaped with a spatula-shaped
trichogyne; antheridial units globose, few in a cluster, cut off from
the tips of lateral branches; carpospores many, forming a dense
mass within the center of a whorl.
Attached to submerged logs in flowing water; fruiting late in
summer. Mich., Wis.
FAMILY LEMANEACEAE
In this family the thallus is a branched, solid or hollow cylinder
[ 568 J
and does not show the axial plan of the Batrachospermaceae. Other
essential characteristics are found in the behavior of the zygote and
the method by which carpospores are formed.
LEMANEA Bory 1808, p. 181; emend. C. A. Agardh 1828, p. 1
Juvenile stage composed of a branching filament, attached to
rocks and other objects in swift-running fresh water; mature plant
consisting of tufts of macroscopic, tubular reproductive strands
which have regularly placed swellings (nodes) distributed from
the tip to the basal stipe; strands generally olive-green, green, or
purple, leathery, 1-40 cm. long, with nodes 0.2—2.0 mm. in diameter;
antheridia produced at the nodes and carpogonia developed inter-
nally, with trichogynes extending to the outside; carpospores formed
within the thallus, which is hollow except for an axial filament which
is either naked or closely covered with enveloping filaments; juve-
nile stage maturing during winter; fruiting strands reaching their
mature size in the spring and spores becoming evident in late spring.
Lemanea fucina (Bory) Atkinson 1890, p. 222
Pl. 186, Fig. 7
Juvenile stage a mat or tuft 1-2 mm. high, of blue-green or green
filaments; fruiting strands generally olive or yellow-green, 2-40 cm.
long, with a stipe which is usually cylindric and passes abruptly
into the wider portion of the strand above, strands simple or much
branched, very delicate to stout, tips sometimes capillary; antheri-
dial papillae and nodes either plane, or prominently raised or
swollen; papillae 2-7 at each node; carpospores not developed in
the internodes.
Collected from Stevens Point, Wisconsin, by L. S. Cheney; speci-
men in University of Wisconsin Herbarium.
TUOMEYA Harvey 1858, p. 64
A macroscopic, cartilaginous and firm thallus with antler-like,
dichotomous branching, brownish-green or gray-green, essentially
composed of an axial row of large cells heavily invested by a mass
of longitudinal, cortical filaments from which out-turned branches
of ellipsoidal cells arise, thus producing a crowded pseudoparen-
chymatous cortication; thallus without nodes or whorls of branches;
plants monoecious, the carpogonia and antheridia developing in
different regions of the same plant, the female near the meristematic
apex in the main axils of the young branches.
[ 569 ]
Tuomeya fluviatilis Harvey 1858, p. 64
Pl. 132, Figs. 8-11
Characters as described for the genus; plant gray-green, 2-5 cm.
high, cartilaginous and firm, retaining its shape when lifted from
the water.
Attached to logs and on the rim of a dam in swiftly flowing
water. Wis.
[ 570 |
AN ANALYTICAL KEY
TO THE GENERA
Genera that are to be expected to occur in our region but have so far not
been reported there are indicated by asterisks. (See also Note 2, page 92. )
1. Plants macroscopic, 540 cm. high, growing erect from rhizoidal
attaching organs and showing stem-like branches with inter-
nodes and nodes from which whorls of ‘leaves’ arise (Pl. 79,
Fig. 1); not inclosed in mucilage)___—_—_=———— Characeae 170
1. Plants smaller, mostly microscopic, if macroscopic and showing
whorls of branches, inclosed in copious, sometimes firm, muci-
| OE 2
2. Cells with pigments confined to 1 or more definite chloroplasts
or chromatophores® = 3
2. Cells with pigments diffused throughout the protoplast (some-
times more dense in the peripheral region ) ____--------_-----------_-___ 252,
3. Chloroplasts grass-green, chlorophyll predominating; plants form-
ing starch or paramylon as a reserve food (starch-iodine test
usually positive) 3) 4
(Cf. Euglena, Sphaerella, and Trentepohlia, which may have
green chloroplasts masked by red pigment. )
3. Chloroplasts or chromatophores some color other than grass-
green, or with green masked by presence of other pigments; food
reserve mostly oil or glycogen; carbohydrates not stained blue
ype todime a ily/
(cf. the motile unicell Cryptomonas, however )
4. Plants unicellular, solitary (See Desmids: Appendix).............0.0.0...... 5
4, Plants not solitary unicells __________-_____-________________----- 12
5. Cells motile in the vegetative state (sometimes non-motile in
microscope mounts, with organs of locomotion GbSCUTE) ae 6
5. Cells non-motile in the vegetative state _________----—-—---------------__-__-- 81
6. Cells with numerous small, green, ovoid chromatophores; food
reserve paramylon or oil; swimming by means of 1 or 2 long,
whip-like flagella (Pl. 86, Figs. 1, 8.) aE SLL be ADs hs 172
6. Cells with 1 plate-like, cup- or star-shaped chloroplast; food re-
serve starch; swimming by 2 or 4 short flagella (Pl. 1, Figs. 3, j C7 BS) eno 7
WeyBlagelle, (2,20 en SS 8
We Blage le) Ae eS 11
8. Cells ovoid to ellipsoid, with the protoplast situated at some
distance within the cell wall and connected to it by radiating
protoplasmic strands; chloroplast often masked by a red pig-
Menit (MmAcmIALOCHTOMIC ) =.= Ee Sphaerella (in part)
8. Cells with or without a gelatinous sheath but without protoplas-
mic strands connecting the protoplast to the cell wall -_--________ 9
8See Trachelomonas and Dinobryon; species are identified by shape and markings of brown
or colorless empty tests or loricas.
[571 ]
10.
10.
. Cells round in end view; the wall simple and in 1 piece, some-
times inclosed by a mucilaginous sheath ____»___ Chlamydomonas
. Cells compressed when seen in end or side view; the wall
bivalved and laterally extended on either side of the protoplast to
form an expansion or flange, especially noticeable when seen
FOIA they (SUS ee ea a aes ae ee 10
Cells lenticular or elliptical in side view; valves of wall, when
viewed from the side, apparent in the vegetative condition; cells
often rectangular in front view, with horn-like processes at
the-angless? Shed see eee ee ed * Phacotus
Cells ovate in side view; the valves of the wall evident only
during cell division or release of swarmers; cells circular or
OVOIGMI ATONE Vie Wis neat es EEE TL en ee nk eee a Se * Pteromonas
. Cells elliptical, ovoid, or somewhat heart-shaped, with 4 flagella
arising from the midregion of the anterior end Carteria
. Cells ovoid in front view, quadrate in end view, with 4 rounded
lobes; flagella 4, each attached in a depression of the anterior
Ti Cl See ee rrp I el tle et 2h Re NET Nl eA PES TT Pyramimonas
. Plant a motile colony; cells inclosed by colonial mucilage; swim-
ming bysmicanston2)or4. tape lla eee See eee eee 13
. Plant non-motile in the vegetative condition; filamentous, or con-
sisting of a definitely or indefinitely formed colony or aggregate
of cells. (See. Desmids:)-Appendix)= 2 3 eee eee 20
. Colony composed of cells arranged to form a flat or twisted plate 14
» Colony*spherical. spheroidal "or, ovoid = = 15
> Colonysa’ circularjon rectangularplate == eens Gonium
. Colony an ovoid or horseshoe-shaped plate, broadly rounded
anteriorly, truncate posteriorly, with 3 prominent projections
of thecolontal/investment\s = eee ee Sees *Platydorina
. Colony oblong, without a gelatinous investment; cells pyriform, all
directed toward the anterior end of the colony; flagella 4._Spondylomorum
. Colony ovoid or spherical, with a gelatinous investment; flagella 2_____ 16
. Cells with sharply pointed lateral extensions of the protoplast,
arranged to form a mediaa girdle within a spheroidal colonial
Shea thy cnet AE RS ER EU he noe Ee ee Stephanosphaera
«Cells: not arranged as ‘above 2s) 2 sie a oe eee 17
. Cells pyriform, broadest at the anterior end, compactly arranged
in ovoidor ellipsoidal colonies 25s eS Pandorina
. Cells ovoid or spheroidal, not compactly arranged within the
colonial. mucilage, colonies’ globular or ovoid == === = _ 18
18. Colony spherical, involving hundreds of cells (500 to 5000 in-
dividuals ); all the vegetative cells the same size and sometimes
interconnected by protoplasmic strands _..____________-_--___--------------- Volvux
18. Colony spherical or obovoid, involving but a few cells (usually
32-64, rarely up to 256), without intercellular connections — 19
19. Colony spherical, containing cells of 2 sizes which are evenly dis-
tributed at the periphery of the colonial mucilage — Pleodorina
19. Colony obovoid or spheroidal, containing cells all the same size
aad often. arrangedian fers") a Eudorina
20. Plant a pair of trapezoidal cells adjoined along their bases Euastropsis
20. Cells otherwise arranged, or of different shape —______-_--------------------------- 21
[ 572 ]
VAL
21.
22.
22.
23.
23.
24.
24,
25.
25.
26.
26.
27.
27.
28.
28.
29.
29.
380.
80.
31.
Plant a definite colony or an aggregate of individuals either ad-
joined or lying free from one another, sometimes invested by mucilage_...22
Plant a branched or unbranched filament, either a series of cells,
or a tubular coenocyte (without cross walls), or filaments form-
ing an’ attached, cushion-like thalhus= = 116
Colony of cells invested by a common mucilaginous sheath, or
gelatinous matrix, (often close and discerned with difficulty;
SECT DICE OSTIINICTILLIN) oc eee 23
Colony or aggregate of cells not invested by a common muci-
[emuaris)s hep ae eae AT
Colony attached. or adherent to'a substrate 24
Colony free-floating (sometimes entangled among other algae,
butenoteattachedestovtlae rns) assess aie te eer eee eee 31
Colony saccate, bullate, intestiniform (Pl. 5, Figs. 1, 3), Or
cushion-like when growing on moist substrates (Pl. 3, Figs. 8, 9);
Tis llyennacKOs Cop ice ae en eS 25
Colony shaped differently; microscopic ____________-___________ 26
Cells in 2’s and 4’s, bearing long, fine pseudocilia (PI. 5, Figs.
6, 11) which extend far beyond the limits of the colonial muci-
lagessplants; aquatic = Tetraspora (in part)
Cells without pseudocilia; plants mostly aerial, living on moist
SUIS CERCA es al Palmella (in part)
Colony pyriform, narrowed to form a stipe-like basal attaching
portion; cells arranged at the periphery of the colonial mucilage
(ottentshowimp long, pseudocilia) = Apiocystis
Colony shaped differently; without pseudocilia She Pas eae SE 27
Colony fusiform; cells fusiform (Pl. 4, Figs. 1,2), solitary or in
linear pairs within the colonial mucilage and arranged with their
long axes parallel; colony usually free-floating but may be at-
PACHECAWHEM YOUNG. Elakatothrix (in part)
Cells not fusiform and not contained in a fusiform sheath —___----- 28
Cells elliptical or subspherical, arranged in 2’s and 4’s within
ungelatinized walls of mother cell; many cells inclosed by a
common mucilaginous investment; a red pigment spot and an
apical papilla often visible —__-- Palmella stage of Chlamydomonas
Cells spherical or ovoid, scattered irregularly throughout the
colonial mucilage, not inclosed within walls of old mother cells;
pigment spot lacking —____.__-____---------= === == 29
Colony composed of cells inclosed in shapeless masses of muci-
lage, with individual cell sheaths confluent with the common gelatine .. 30
Colony irregular, but keeping a definite shape; cell sheaths not
confluent with the colonial mucilage, but definite and often
lamellate (Pl. 3, Fig. 17); plants aquatic or growing on moist
soil, but becoming red in some species when exposed to strong
ALITA EO Tee we ee eg a Je Oe Gloeocystis (in part)
[ 573 ]
31.
32.
32.
33.
383.
34.
42.
42.
Coloniestshaped differently from above=._ See 82
Fragments of old mother cell walls lying scattered about and
partly inclosing spherical daughter cells; colonial mass soft and
shapeless, usually floating at the surface__________________ Schizochlamys
Fragments of old mother cell walls lacking or, if present, not
scattered among daughter cells; colonial mass of definite shape____ 83
Colonies irregularly globose or spherical; cells arranged in groups
of 4, the clusters remote from one another within copious muci-
lage; cells bearing long pseudocilia (visible only under favor-
able optical conditions))h == = ee eee Tetraspora (in part)
Colonies of various shapes; cells not arranged in groups of 4,
and! without pseudocilia 2-0 0c 2 03” Ee ee ee ak 34
Cells ovoid, compactly arranged in semi-opaque mucilage, form-
ing dense, simple or compound masses, adhering to one another
by branching strands of mucilage (Pl. 52, Figs. 1, 2); individual
cells often not apparent in older colonies because of dark muci-
lage and density) of cell contents. Botryococcus (in part)
. Cells not arranged in semi-opaque, irregularly shaped colonies... 35
. Chloroplast a stellate mass with radiating processes. Asterococcus (in part)
si Chloroplast, not)stellate ss ee. mia bate oe eV ey 5 ate EST se ee 36
. Cells arranged in groups of 4 at the ends of branching strands
formed by the remains of old mother cell walls; colony ovoid
OLE IG DOSe PENAL Sai Ae Pied Slt lined Caan SEEPS ES Sie etd eee 87
. Cells not arranged at the ends of branching strands; colony of
VAnLOUSS SHADES 22 see ce SE he Oe Es ee ee ee 88
. Cells reniform to sausage-shaped and some also appearing ellip-
soid in each group of 4, at the ends of branching strands (gela-
tinous investment usually lacking)... Dimorphococcus (in part)
. Cells spherical or broadly ovoid, all the same shape, in groups of
4 at the ends of branching strands____________________________ Dictyosphaerium
b Gells ssylneri cal = aks ee a ee a 39
. Cells of various shapes, fusiform, ovoid, reniform _____---------------- 42
. Cells arranged in linear series (single or double) within branched
gelatinous strands; either with or without individual lamellate
sheaths ea seees out os Be eRe ne aE eS, Palmodictyon (in part)
t Gells\ arranged! otherwise... ee ee ee
. Colonies spherical or irregularly shaped, sometimes triangular,
with cell sheaths distinct and not confluent with the colonial
IMC ape eae mee seu _ .. .... Gloeocystis (in part)
. Colonies spherical; cells without individual sheaths, or with
sheaths confluent with the colonial mucilage and not apparent ____---- 4]
. Cells with cup-shaped chloroplasts containing a conspicuous
pyrenoid; colony usually showing daughter colonies of smaller
cells resulting. from cell division. = 2) Sphaerocystis
. Cells with several peripheral, polygonal chloroplasts, each with a
pyrenoid (when cells are young with but 1 cup-shaped chloro-
plast; in this condition to be compared with Sphaerocystis );
colonies never containing daughter colonies, but frequently dis-
integrating so that cells become solitary______ Planktosphaeria (in part )
Cells lunate or sickle-shaped, with narrow poles —_____--------------------—-- 43
Cells reniform or fusiform, with rounded apices -_.....---_------------------- 44
[574]
43.
Cells strongly curved so that the poles nearly touch, scattered
throughout the colonial mucilage in groups of 4, generally with
the convexs walls} (apposed i) ss 9 sy Kirchneriella
. Cells crescent-shaped, arranged in groups of 4, 2 of which are
in one plane facing each other, and 2 at right angles to this
plane, each of the latter adjoined to one pole of the cells in
theyothers pair’ 25. 5. + stars, hehe gd eee iiaaa lies ie Tetrallantos (in part)
peC@el sehen eh corer 02) A OE. cee ee en Oded Meee TEN oll 46
u@ellstovates seniors oroblong = 2 we ane mented) eee Wen ih 45
. Cells ovate, arranged in 4’s within a gelatinous sheath, forming
Anite bap labceen eee WW sn it hub iS Ge DE aReR ee rene 6 ORS MOTE UF A Dispora
. Cells reniform or oblong, reproducing by autospores usually re-
tained within the old mother cell wall which may gelatinize
and appear as a mucilaginous sheath... Nephrocytium (in part)
. Cells solitary or in linear pairs within a fusiform, gelatinous enve-
lope, multiplying by cell division. Elakatothrix (in part)
. Cells arranged in parallel bundles of 4, reproducing by auto-
NSE ONES. Quadrigula
SPOTFeEs: _-2-_________-
. Cells, or some of them, in clusters, bearing gelatinous bristles
OLE SCtAG a ee ce ee ee ee Ee Te Ce en cat On eNom bell ln eco Seine EID |. 48
. Cells not bearing gelatinous bristles with or without spines................ 49
. Cells compactly arranged to form an adherent, dome-shaped
cluster within the old mother cell wall which bears a dichoto-
mously branched seta. (This cluster of cells results from the
formation of zoospores and not from division to form successive
generations of vegetative cells.) Dicranochaete (in part)
48. Cells globose, epiphytic, loosely arranged side by side to form a
cluster (often solitary however), each bearing a sheathed, un-
branchedwseta+@ Mose! : Pe Ue AUT 5s Chaetosphaeridium (in part)
49. Cells attached at the ends of branching gelatinous stalks, epizoic
OUEMICTOSCOMiG. AuIMIaIS seca ue Oe 1. ES ee en ed 8 50
400 Gelis not so,atanged ;not.epizoie == ee te ei ee a 51
50. Cells ellipsoid or spindle-shaped, chloroplasts 1 or 2 parietal
| SEPT STG KS Li AE hint Lae ee SE SAL ere Ft 0 ig ene Chlorangium (in part)
50. Cells ovate or oblong, with numerous disc-like chromatophores
(sometimes referred to as chloroplasts)... Colacium (in part)
51. Cells broadly fusiform or elliptic, attached end to end to form
lodsessbranching chains. 5) 27 2 Cea a Dactylococcus (in part)
ey bral@ells mots SO arramG ees: Loker cee a Mee Mine ee eR 52
52. Cells globose or angular from mutual compression; aerial; forming
elumps on moist substrates 22 Protococcus (in part)
52. Cells differently shaped, not forming expansions on moist substrates —__.. 53
53> Cells acienlar or stiehtly lumate = ves ee 54
So, celisiiditrerently. shaped = =) See ley 2 eh el at 55
54. Cells strongly curved, arcuate or lunate, not entangled but closely
aggregated in families of crescent-shaped individuals Selenastrum
. Cells straight or_slightly crescent-shaped, loosely entangled or
twisted about one another; often solitary. Ankistrodesmus (in part)
. Cells adjoined by their lateral or end walls to form definite pat-
EernsxOr akrangements = ts ius eee ed 2 ee 56
. Cells grouped otherwise, not adjoined by their lateral walls or,
itso; notstonming ‘definite patterns =. sates Be oe he 71
[ 575 ]
. Cells cylindrical, adjoined at each end by 2 other similar cells :in
successive order to form a network of coenocytic units, the meshes
ofiwhichware?D= Or G-sid ed) 125-040 erie See Hydrodictyon
. Cells attached by their lateral walls, or clustered to form other
by pes ok ce neg a an ee ee ee eee 57
. Cells forming flat, circular or rectangular plates______»_ 58
Cellsmnotiorming flat plates! 2) sxx5te See eee 61
. Cells forming circular or subcircular plates which may be per-
forate or continuous; marginal cells with a deep or shallow
incision or sinus; cells within the plate usually somewhat different
in?shape from) those atthe margin Pediastrum
» Cells not arranged’ to: formucireular plates! ee ee 59
. Cells triangular or ovoid, the walls bearing 1 or more spines,
LOrming quadrate plates of 4 cells cache = 2 ee Tetrastrum
2 Gellsiio& bearing splices 220 Sa a ee te 2 60
. Cells rectangular or trapezoidal, the outer free walls smooth and
entire, cruciately arranged to form quadrate plates of 4 cells or
TiUtiplesN OL Ai stde tee ES 2k AUS ee ek Sena ee Crucigenia
. Cells trapezoidal, the outer free walls deeply incised, cruciately
arranged to form subquadrate plates of 4 or 8 Pediastrum tetras
. Cells bearing: spines: 2: Sethe 2 ee 62
: Gells without. spinest= 2 2). Sa ee 65
. Cells ellipsoid, bearing many needle-like spines, adjoined side by
side to form clusters of indefinite number (usually 2 to 8), some-
HINES :SOlitan yo tleAe ec Oe ee ak eS) Franceia (in part)
. Cells with few spines (1 to 4, rarely as many as 7); cells defi-
mittely darrian cece 6 ps Os ce ee 63
. Cells ovoid, adjoined side by side, forming a linear series (single
or double ); spines usually few in number and mostly confined to
the poles of the cells or with 1 or 2 on the lateral free walls
(many minute spines in Scenedesmus hystrix) Scenedesmus (in part)
. Cells spherical, arranged in groups of 4 and multiples of 4 to
form compound colonies; outer free walls bearing 1-7 very long
BEM eT SOLS rena ete ee 64
. Compound colony triangular in outline; spines 1 to 7 in num-
| oY =i ems. ie PO SEN SS WARES Tee inte ely AIR ete a Fae ET fe Bl ae Micractinium
. Compound colony always pyramidal in shape, outer free wall of
cells bearing a single, stout long spine _________. *Errerella bornhemiensis
. Cells spherical or trapezoidal, arranged to form hollow, spherical,
or polyhedral colonies, the cells adjoined by interconnecting
protuberances 228 22s ee eee Coelastrum
; ells not arranged in hollow colonics == ee 66
. Colony composed of narrowly fusiform cells radiating from a
common center where they are adjoined at their poles —______ Actinastrum
. Colony not composed of fusiform cells radiating from a common
Ceriter esc sha Oe Is eR ee we 8s) Ee a ee 67
. Cells elliptical or fusiform, attached end to end to form branch-
mip, chain-like series. +s Sos ee Dactylococcus (in part )
. Geélls not forming such branching chains 2222 = 68
. Cells ovoid, elliptical, or fusiform, adjoined by their lateral walls
to form a series of 4 or more cells lying side by side in one
plane.(rarely im a icurved plate) <3 Scenedesmus (in part)
[ 576 ]
. Cells round or, if shaped otherwise, not attached side by side
id OMG yl avis men ome ae e/a 5hc And Re Ree eke A a | 69
. Cells fusiform or trapezoidal in face view, adjoined by their inner
faces in groups of 4 about a common center; long axes of the
COE) VIS) a || a se re, re Tetradesmus
. Cells differently shaped, not attached about a common center___._____ 70
. Cells lunate or crescent-shaped, arranged in groups of 4, two cells
in one plane, and two in a plane vertical to the other pair (Pl. 66,
Figs. 4,5), one pole of each of the latter pair adjoined to a pole
of the cells in the former; cells usually inclosed
HTIBIMUCTIAD OW tie Set e $ 25 Lo ty A A oe Tetrallantos (in part)
. Cells fusiform or needle-shaped, twisted about one another to
form a definitely shaped knot of individuals, or a somewhat ir-
Regma Cluster a ns. ee Ankistrodesmus (in part)
71. Cells held together by fragments of mother cell walls of previous
generation (Pl. 53, Fig. 14; Pl. 55, Fig. 8) Pea eins) See yh?
71. Cells not held together by fragments of mother cell walls. 73
72. Cells spherical, arranged in groups of 4 or 8, fragments of older
78.
78.
mother cell walls forming loops which help to hold the groups,
cormnarant tip leseolontes =e smu he ot Westella
. Cells both ovoid and reniform, in groups of 4, arranged at the
ends of branching strands formed by old mother
Gell weallllsseane sree bt a eee a De ee a Dimorphococcus (in part)
. Cells pyriform, semi-lunate, or reniform, bearing spines on their
outer faces, each cell at the end of a short, thick, gelatinous stalk
which radiates from a common center where it adjoins stalks of
otherucelis im the colomy s. 20s we ea Sorastrum
. Cells of different shapes, not arranged as above... 74
. Cells spherical or broadly elliptic, closely arranged in 2’s and 4’s
within the old mother cell wall, the cells separated from one
another by semi-opaque masses of mucilage, sometimes with a
plug of dark mucilage in the outer free wall of
Cachicelle aes Sle ce 2 Lee aes 8 Pe 208 Gloeotaenium (in part)
. Cells of different shapes, not separated by dark bands of mucilage_____ (a3
. Cells spherical, bearing spines; loose and temporary clusters
formediiby entangling iof spines 26. =. 3.) Sate Golenkinia (in part)
2) Cellsenots bearing (spines teas Scie i aie Se 5 Te 76
m@ellstmclosed by old, mother cellwalls! a et if
; Cells not-inclosed’ by’old mother’ cellwalls 2 2). 4 78
. Cells reniform or broadly elliptic, inclosed by old mother cell
walls (often gelatinized, thin, and appearing as a mucilaginous
Shea thy) ete aT Pe Shr ee nh wh LRP ate Nephrocytium (in part)
. Cells elliptic, moniliform, with nodules at the poles in some
species, or subcylindrical, or panduriform (retuse lateral margins);
old mother cell wall much expanded,
S@mietimes ela tinizim sce mein eS aL ee es Oocystis (in part)
Cells spherical, with several polygonal chloroplasts; arranged in
spherical clumps or distributed throughout the gelatinous enve-
lope (which is sometimes wanting, or
TUbMap parent) eeeee-. show Memuaes ee SA oe Sh Planktosphaeria (in part)
Cells more loosely arranged, sometimes solitary; chloroplasts
EIQ E pO Yeo ed ee oan eee Re ene efor ste Pe ae oe 98 ST) 79
. Cells spherical, not bearing spines; subaerial or terrestrial, some-
tameseregarious: and densely clustered == emeeenens eee 80
. Cells aquatic, fusiform, acicular or needle-like, loosely clustered
OTA TLAN CEC et es tn esha aU ea Oe eee eee Ankistrodesmus (in part)
. Cells gregarious (although sometimes solitary), but not adjoined,
usually in several-celled clusters on damp soil or moist sub-
strates; chloroplast not lobed = sesame Chlorococcum (in part)
. Cells in dense clumps and adjoined, rarely solitary; spherical,
or angular from mutual compression; chloroplast a dense, lobed
plate early filling: the cell = Protococcus (in part)
(Pleurococcus )
& Cells tbearingspmes Or Sete ea = «. sash einen ter tUR ee ee Lae eo 82
aw Celis#wathorit ys pimesiOr Setae 2 si: wanetens sate sree ee een teed eevee Cae eae 93
. Cells bearing a simple, sheathed seta___________. Chaetosphaeridium (in part)
-/Cellsinot bearing arsbeathed! seta 2-2) Sass ee ee 88
. Cells bearing a single dichotomously
branched sar 20 soe /eteee hee a fy Ca Se Dicranochaete (in part)
. Cells not bearing a dichotomously branched hair____________________________ 84
. Cells ellipsoid or ovate, bearing 1 to 4 teeth or short spines,
mostly at the poles; cells usually attached side by side, but
sometimes: solitan= ne ein ns Scenedesmus (in part)
. Cells fusiform or some other shape than above or, if ellipsoid,
bearing long spines over the entire surface of the wall .._-_-_-__»____- 85
. Cells triangular, pyramidal, quadrangular, or polygonal _______»____ 86
“ Cellsvovate round fusitorm.ior acicular2 = a" ses eee eee 88
. Cells pyramidate or tetragonal (rarely pentagonal), with 4 to 6
fine, needle-like spines radiating from each angle (see, however,
Rolyedtiopsisn. quadrispina) = eno: Sa ee Polyedriopsis
. Cells pyramidate or polyhedral, without a tuft of needle-like
spines ‘at eachmangle situ sas hn es SE a ee eS 87
. Cells triangular, polygonal, or pyramidal, consisting of a definite
body with 3 short, stout spines at the angles or at the apices
OP MprOCesses es sates fil t ENG. SO WO ae Tetraédron (in part)
. Cells pyramidal, each angle extended into a long spine-like pro-
cess, the body of the cell small in diameter and not distinguish-
able trom) the ‘basesiof thes processes 25 0s. sas sae) Pee Treubaria
. Cells acicular or fusiform, the poles extended to form a long,
finely-pointed seta, one of which may fork at the tip and serve
as jan: attaching: organs see soe alm Eola ha ee Schroederia
, (Gals sete aroronllere Gye aarcinioynin 89
» Cellsiglobose; with radiating spnes= = 90
» Cells wovatéewon,jellipticalle*s.25)) Je) eee 92
. The entire wall beset with long, stout, tapering spines which
ANC ADEOAGWAtEthiC bac pes e eee eae ie eam ce eee Echinosphaerella
. Cells bearing needle-like, slender spines________________________- 91
. Spines needle-like throughout, gradually tapering to a
Tne) 2) 0 OLE Ras Aaa a eM ENCES Bie Si Sh ene OLN Golenkinia (in part)
. Spines with basal portion thickened, then tapering abruptly to
a, longs inely,. pointed | tip, 3.8 gaa te ses Acanthosphaera
. Cells elliptical, with fine, needle-like spines arising from all
pantsyofsthes wall wlie 2 aan her Cd Bev ieee Franceia (in part)
. Cells ovate or ellipsoid, with a few long spines at the poles or
localized at. both poles and equator. = =o ee Lagerheimia
[ 578 ]
93.
93.
94.
94.
95.
9a:
96.
96.
Sle
ile
98.
98.
99.
99:
100.
100.
101.
101.
102.
102.
103.
103.
104.
104.
105.
105.
106.
106.
107.
107.
Cells irregularly globose or ovate, endophytic, buried within
the tissues of higher aquatic plants. Chlorochytrium
Cellsenotiendo phytic = ena ee 94
Cells endozoic, inhabiting the tissues of sponges, Hydra, and
I0L0 202 ee Zoochlorella
Wel stretch ZG ee 95
Cells epizoic, attached to small crustaceans such as Cladocera
and copepods 8 96
Cells not epizoie _.98
Cells fusiform or acicular, with a single diffuse chloroplast;
attached by avslender stipe = Characium (in part)
Cells ovate or elliptic; chloroplast not a diffused sheet; attached
by a thick stalk 97
Cells with 1 or 2 laminate, elongate chloroplasts Chlorangium (in part)
Cells with many ovate, disc-like chloroplasts (usually in branched
colonies. sometimes, solitary )— == Colacium (in part)
Cells free-living, not epiphytic or endophytic -__________________-- 100
Cells epiphytic ———_----—--——---------—-— 99
Cells globose, gregarious, attached by the anterior end, which is
elongated to form a narrow stipe; with a massive chloroplast in
the upper (posterior) end of the cell; growing in the mucilage
of blue-green algae_._________________------—--------------__------- Stylosphaeridium
Cells fusiform or cylindrical, attached to filamentous algae or
higher aquatic plants ______---------------________---- Characium (in part)
Cells fusiform to acicular, much longer than their diameter_— 101
Cells not spindle-shaped but of various other forms: spherical,
ovate, oblong, pyramidal, or polygonal _____-_-__________-----_---- 102
Cells narrowly fusiform, 3-6y in diameter, 50 (or more) times
longer than wide ._________-__-_----------------------- Closteriopsis
Cells much smaller than above, length less than 25 times the
GATING LET eee en ER, | er inte ae et eae Ankistrodesmus (in part)
Cells spherical, inclosed in a wide, spindle-shaped, 2-part enve-
lope (the parts adjoined at the equatorial plane). Desmatractum
Cells not inclosed in a spindle-shaped envelope -—---__----------~ 103
Cells spherical, wall decorated with a reticulum of ridges which
form blunt or sharply pointed projections at the periphery Trochiscia
Cells variously shaped; if spherical, without a Teticulum: | ee 104
Cells broadly and irregularly ellipsoid or subspherical, with
thick uneven stratiiied, walls Excentrosphaera
Cells spherical or of other shapes, without thick stratified walls. 105
Gells spherical 106
Cells not spherical iis
Cells containing a single axial, stellate chloroplast with radiating
processes which become flattened at the periphery
Felice) | ee ee ae eens oe ee Asterococcus (in part)
Cells not containing a stellate chloroplast) = = 107
Cells large (50-300» in diameter ), globular, containing numer-
ous ovate or disc-like chloroplasts arranged in radiating cyto-
plasmic strands and in a layer about the wall; chloroplasts shifting
their position in response to light intensity Eremosphaera
Cells smaller, without numerous ovate chloroplasts Rete: 108
[ 579 J
108.
108.
109.
109.
110.
110.
JO
ul ts
112.
112.
113.
113.
114.
114.
115.
115.
116.
116.
1a Uele
IBGE
118.
118.
Cells inclosed by a gelatinous sheath, with a parietal chloroplast
that nearly covers the wall (plant usually colonial but sometimes
occuring as asingle cell). => ee Gloeocystis (in part)
Gells notimclosed by . seen ste ses ere: ee *Gonyaulax
. Cells with 2 antapical plates, slightly flattened dorsiventrally_ Peridinium
. Colony actively swimming by means of flagella ___.._.___.-__._.-_-_.--.... 248
. Colony non-motile, or cells with rhizopodal processes __.___----- 247
. Cells 2, or 4-8, irregularly arranged in a common mucilage_....Chrysocapsa
. Cells 16 (rarely 32) radially arranged in a wide gela-
tinous sheath which is heavily impregnated with granular
Waste | PrOGUCES oul med 9 ies ye oe ew trey a2 Chrysostephanosphaera
. Colony spherical, composed of ovoid or pyriform cells arranged
ab thes penphery of a colomalmucilage 26 ee eee eee 249
. Plant not a spherical colony of ovoid or pyriform cells —__...-- 251
. Cells each with 2 apical cylindrical receptacles from which a
longesiliciouswnodvextends/.05 Samar. ese kee ee ee ees Chrysosphaerella
iiGells* not ibearing? silicious, 10ds'= 2 = eee 250
. Cells elongate-ellipsoid, or elongate-pyriform, with silicious scales
in the apical region; swimming by 2 flagella of equal length Synura
. Cells small,ovoid or pyriform, without apical silicious scales;
flagellac2qunequal imilength! 2222.2 2 eee Uroglenopsis
. Cells amoeboid, without loricas, adjoined in loose linear series
by thenslong-tthin, pseudopodia 8) ee Chrysidiastrum
. Cells with vase-shaped or conical loricas, forming arbuscular
or diverging colonies, with 1 or 2 loricas emerging from the
mouth of the lorica* below... ees SS eee Dinobryon (in part)
. Plant an attached parenchymatous mass in which filamentous
arrangement of cells is not clearly evident; endospores formed in
the upper or outer cells of the plant mass, or of the branches__.*Pleurocapsa
. Plants otherwise, not a parenchymatous mass .______------------------------- 253
. Plants unicellular or colonial, usually with an evident sheath,
Which mayebesiamellated 2 ee ee 954
. Plants filamentous; cells arranged in 1 or more series and in-
closed or not inclosed by a sheath (Pl. 112, Figs. 1-8). (The
series of cells is termed a trichome and this, together with its
sheath, is called a filament in this group of the algae.) 274
[ 590 J
254.
254,
255.
255.
256.
256.
257.
257.
258.
258.
259.
259.
260.
260.
261.
261.
262.
262.
263.
263.
264.
264,
265.
265.
266.
Plant a spirally twisted, long or short unicell, usually showing
Oseillatme@Or-spiral movements #22. Spirulina (in part)
ear tO ter WV iSe ees a see me ee ES Ss 255
Plant an epiphyte, a sheathed, club-shaped unicell usually show-
ing endospores (Pl. 108, Figs. 5, 6), which are cut off success-
ively from the apex of the protoplast _____________________. Chamaesiphon
Plant solitary or colonial, not forming endospores; not a club-
Shiga (iitte 2) | 256
Cells embedded in a mucilaginous sheath which may be lamellate__. 262
Cells not embedded in a common mucilaginous or gelatinous matrix___.257
Celisigio bases SS SS 258
Cells longer than wide, oblong or cylindrical ___________________. 259
Cells minute, 1-5 in diameter, solitary or gregarious (usually
with a sheath, but this is often not apparent)____ Chroococcus (in part)
Cells larger, up to 504 in diameter (colorless host cells with
vermiform, endophytic blue-green protoplasts )_______ Glaucocystis (in part)
Cells solitary or sometimes in families of 2-4; oblong or broadly
ovate to subcylindrical, up to 504 in diameter —___________-_____ 261
Cells in small colonies or rarely solitary, cylindrical, strongly
Canved! or pyriorn == 260
Cells in small clusters, sometimes solitary, strongly curved, de-
scribing nearly a complete circle, sometimes lying with long axes
parallel in compact series within the mucilage of other algae __Cyanarcus
Cells pyriform, radiately arranged in small colonies and inclosed
by an inconspicuous gelatinous investment, which is invisible
dinless stained se ie Su en Se ee Marssoniella
Cells ovate, solitary or in families of 2 to 4, inclosed by old
mother cell wall (colorless host cell with endophytic blue-green
protoplasts), up to 504 in diameter______________ Glaucocystis (in part)
Cells oblong or subcylindrical, up to 15y in diameter, not sym-
| US aUSR AES 51 0 Oh Gene Re is Swe el a ee Synechococcus
Cells globose, 2-16 in a mucilaginous sheath in which individual
cell sheaths are visible; free-floating or adherent, sometimes
Rats enlace ee eee pee ne eee ee Chroococcus (in part)
Cells globose, cylindrical, or elongate, forming many-celled
colonial aggregates of more than 16 individuals, inclosed by
copious mucilage which may or may not be lamellated —_________. 263
Cells 10 or more times their diameter in length, cylindrical,
Ret ORTH) OR PusifO ria se ee eee 264
Cells 2 or 3 (rarely as much as 8) times their diameter in
length; round, ovate, or short cylindric —-—______________------------- 265
Cells narrowly fusiform, with tapering, blunt-pointed
Sie ee Dactylococcopsis
Cells reniform or vermiform, straight or variously curved__. Rhabdoderma
Cells minute, 0.61.5 in diameter, bacilliform, crowded within a
colorless colonial mucilage; pigment scarcely discernible... Pelogloea
Cells larger, or not bacilliform; pigment readily discernible 266
Cells oblong or short cylindric, with poles rounded, crowded
and irregularly arranged in copious mucilage; individual cell
sheathsisometimes evident = ( Anacystis, in part )
Including: a. Aphanothece, with individual cell sheaths not apparent;
b. Gloeothece, with individual cell sheaths apparent.
[ 591 ]
280.
. Cells spherical or ovate, sometimes elliptical; not cylindrical,
but/very dlittle longer than “wide =. 267
. Cells round, embedded in copious mucilage with concentric
lamellations; individual cell sheaths becoming confluent; plant
usually formed by large numbers of cells; occurring mostly in
aerial ‘habitats, sometimes aquatic 2 Gloeocapsa
. Cells of different shapes, ovate, ellipsoid, or, if spherical, not
forming shapeless gelatinous masses on moist substrates ——_________ 268
. Cells round, ovate, dividing in 2 planes only to form flat, usually
rectangular, plates, with margins of plates sometimes rolled —________ 269
. Cells dividing in 3 planes to form spherical, ovate, or amor-
POUS Vass ES ol es Se as ee ee 270
. Cells regularly arranged in rectilinear series forming rectan-
Sulaky plates ita 1 a1. Toe Se A ee ae Merismopedia
. Cells irregularly arranged in 2’s and 4’s but not in rectilinear
SCTIES ses MTSE BLE ek Re RL aC ore PA EE Holopedium
. Colony hollow, the cells arranged in one layer near the periphery. 271
. Colony not hollow, the cells distributed throughout the colonial
TIRLIC Wag © oe obo eros wee eee eee ee ee 272
. Cells at the ends of branching, gelatinous strands which radiate
from the center of the colony (sometimes scarcely visible) Gomphosphaeria
. Colonies without radiating gelatinous strands ——________ Coelosphaerium
. Cells longer than wide, distributed throughout the colonial muci-
lage, with or without individual cell sheaths apparent. ( Anacystis, in part )
Including: a. Aphanothece, with individual cell sheaths not apparent;
b. Gloeothece, with individual cell sheaths apparent.
Be Ce llsip clo logs cts eet nete ean 273
. Cells crowded, usually very dense, not evenly distributed within
the colonial mucilage; pseudovacuoles present or absent (PI.
1) 2egiti 0, ly) eee ren ce Seber eee ee Microcystis
( Polycystis )
. Cells evenly and relatively remotely spaced throughout the
colonial mucilage; cell contents granular or homogeneous, with-
Outs pscud Ovactiolcsmes. = @es- ten es Aphanocapsa
. Heterocysts present, although sometimes infrequent —.________ 290
. Heterocysts not present; trichome with or without a sheath,
sometimes more than 1 trichome within a sheath ......________-- 25
} Umichomespspirallyscoiled <=. 276
. Trichomes straight, bent, or entangled, but not regularly coiled 422 278
, TGR nemnes Wriin a Caenin Lyngbya (in part)
Dutra chonie se WwitnOUcray Siacathcesete. ee ees oe os ee ee ee 277
. Plant a 1-celled trichome, up to 3004 long Spirulina (in part)
. Plant a many-celled trichome, the cross walls indistinct; usually
muchwongenthanla poves ss = Arthrospira
. Trichomes aggregated, tapering to a point from an attached
basal prostrate: cushion oficells= == Amphithrix (in part)
. Trichomes not tapered, or if tapered, without a basal prostrate
GUS HIOM La Cell smn tera ee ee en ia See ee ee ne ee 279
. Trichomes without a sheath (though hormogonia may show
aeithiiy Seeat ins) Meee ames ett eT heh ee ee es ee Oscillatoria
. Trichomes with a sheath which is usually very definite 280
. Trichomes tapering from base to apex, often ending in a Frat en 281
Trichomes not tapering, the same diameter throughout their length 282
[ 592 ]
. Trichomes gregarious, apices extended; plants parallel in a
Ceol STEN Fi CM ir 2s) ews oS abe Amphithrix (in part)
. Trichomes diverging; plants not parallel_______________- Calothrix (in part)
. Trichomes with false branching (branches sometimes infre-
CGH) eee eee ee eS Plectonema
ME raichormes emo t. brane lie Ce a ee 283
. Sheath containing a single trichome_____—_______-______________ 284
. Sheath containing more than 1 trichome —__——___________________. 287
. Sheath firm and definite, not adherent to sheaths of other plants
andi not comhuent fee Lyngbya (in part)
. Sheaths mucous and sticky, confluent with sheaths of other plants
(sometimes individual sheaths indistinct unless stained ) 285
. Trichomes lying parallel, forming planktonic fascicles. *Trichodesmium
. Trichomes not forming planktonic fascicles; sheaths mucous
EATNGE GL PETA UT Ua tesa ce ede We, en ee eee ee nes eee ee 286
. Trichomes much entangled (sometimes parallel), forming mucous
plant masses and often thick layers on substrates; sheaths
watery (best demonstrated with chlor-zinc-iodide reagent—see
Drouct..19a1.(p) 604) = Phormidium
. Plant mass forming erect tufts from an expanse on a substrate;
sheaths usually firm; plants mostly terrestrial _________ Symploca
. Sheaths firm, usually branching at the ends ____________________________ 288
. Sheaths wide, mucous, soft and sticky, dividing and frequently
anastomosing at the ends ____________--_---------_-----------___-- 289
. Sheath wide; trichomes few and separate, not intertwined. *Dasygloea
. Sheath close, trichomes many, intertwined. Schizothrix
. Trichomes loosely arranged, 2 to 4 in a sheath —_____ Hydrocoleum
. Trichomes densely entangled, many within a sheath Microcoleus
. Trichomes decidedly tapering from base to apex 291
. Trichomes not tapering from base to apex —----------------_---------— 295
. Filaments inclosed within a copious mucilage, many united to
form a globose or hemispherical attached or free-floating thal-
lus of macroscopic size ———___________-_-______-______— 292,
. Filaments not inclosed in copious mucilage to form thalli 294
. Sheaths containing 2 or more trichomes. Sacconema
. Sheaths containing but 1 trichome_—__--------------------------------------- 293
. Trichomes bearing cylindrical gonidia adjacent to the basal
heterocyst; enveloping mucilage not hard and granular (al-
though firm in 1 species); thalli free-floating or attached____ Gloeotrichia
. Trichomes without gonidia; colonial mucilage hard, often gran-
ular; thalli attached; trichomes radiate or often parallel in ex-
panded gelatinous masses —_--.--------—-—--—--—-----——_-------= Rivularia
. Filaments freely branched, the basal portion of the branches
inclosed for some distance within the sheath of the primary
filament; not epiphytic _—________ Dichothrix
. Filaments seldom or not at all branched; branches not inclosed
in the sheath of the primary filament; plants usually epiphytic;
solitary or gregarious. _-_____________-___»_ Calothrix (in part)
. Trichomes exhibiting true branching (branches arising as a
result of cell division in 2 planes) —_______--------------------------------- 296
. Trichomes exhibiting false branching, or without branches ___--------------- 299
. Trichomes and lateral branches uniseriate; heterocysts lateral,
mostly on the ends of short branches -__.----_-_--------- * Nostochopsis
[ 598 ]
. Trichomes and lateral branches multiseriate with wide muci-
laginous sheaths, or uniseriate with close, firm sheaths; hetero-
cysts not/ontthe ends of short lateral branches ee 297
. Filaments uniseriate; sheaths firm, close; heterocysts oblong
EO “ey limebraca eae oo oo near te Ose ee ee Hapalosiphon
(cf. Stigonema ocellatum )
. Filaments multiseriate’ (rarely uniseriate in part), with wide
mucilaginous sheaths; heterocysts compressed, spheroidal, usually
lnteralvonva-vesetative (cell: uses saa mete Aieee Ne ee eee eee 298
. Branches as wide or nearly as wide as the main filament; hormo-
gonia not formed in the apices of the branches__.___-_»_»_»____ Stigonema
. Branches narrow, erect, with hormogonia formed in their apical
TES IOWA eee nj on Ria Rle es he Beg Aa Lar Be ee Re Fischerella
* richomes cwithoug,branchesee et wee aie ea Ne 800
arichomes; with false branches. o sie Ca oe) eee ee eee un ae 810
. Trichomes with a basal heterocyst (sometimes intercalary hetero-
cysts also): (sheath firm\and definite. 2 = 322 2) Microchaete
. Trichomes without a firm sheath; heterocysts either always ter-
minalwonsalwaysesitercalary == sss seal eee es See 301
» Eleterocystsi always) terminals: = 2058 oe) 8 es ee ee 302
ou Lleterocysts) always: intercalanys =. ee 803
. Heterocysts at one end, rarely at both ends, of the trichome;
gonidia formed adjacent to the heterocysts__._______________. Cylindrospermum
. Heterocysts at both ends of the trichome; gonidia remote from
thephetenocy sts a. te eee Pore ee ee ree Anabaenopsis
. Plant formed of many trichomes, often lying parallel to one
EN GUOLCAY=) oy ee sea eee Sua hatn A, Nat pale so) Maple Be) heh Sell Greet DA hay ARWUED Ary ie Se DPA att 804
. Trichomes solitary or, if gregarious, entangled, not parallel _____. 306
. Trichomes surrounded by copious mucilage, forming hollow,
attached, tubular or bullateamasses ses seeeen ee eee Wollea
. Trichomes not forming attached, tubular or bullate masses, but
occurring in free-floating bundles or fascicles __._.__.__-___________. 805
. Trichomes very slightly tapering toward both apices; many
within free-floating macroscopic flakes of definite shape; gonidia
always solitamy:—--2/=5 Siiat ves aa ee ee Aphanizomenon
305. Trichomes not tapering toward the apices; forming flakes of
irregular outline; gonidia usually in a series (solitary in some
SPECles,) |. kat ster tk se Es GY ee a ees Rl Anabaena (in part)
306. Trichomes solitary, planktonic among other algae» 807
306. Trichomes aggregated in a gelatinous mass of definite or in-
definite: ‘Shapess=<4 "ae tte ke. | xe Die Bs 308
307. Cells disc-shaped, much shorter than wide; heterocysts com-
pressed ___. PD) fe Last 0) Pe Ais Sa SRS RnR, Py ees Sek ST A PP Nodularia
307. Cells not disc-shaped but globose to cylindrical; heterocysts
MOts COMpressed ewes mek es Fe ee i as Anabaena (in part)
308. Plant mass of definite shape, the periphery of the colonial
mucilage forming aytemument ses a ee Nostoc
308. Plant mass not of definite shape; colonial mucilage soft, not
bounded’ by. .a/firmtegument 22 eee 309
309. Trichomes forming small packets, entangled, sometimes sub-
parallel, inclosed in a gelatinous sheath _____.-__-_______-_-__- Aulosira
309. Trichomes not forming packets, individual sheaths lacking, or
MOtydehinite 2. | RUF eas Bod Neat i stale Anabaena (in part)
310.
$10.
811.
811.
Branches usually arising in unilateral pairs about midway be-
tween the heterocysts of the main filament; sheath firm and
lamellate: rarely vhomogeneous 225 ee Scytonema
Branches arising singly, just below a heterocyst or a series of them_—_ 311
Filaments aggregated, somewhat radially arranged in a muci-
laginous layer; branching regularly dichotomous; heterocysts
S10) ey a a Se ee Diplonema
Filaments solitary or aggregated, sometimes forming free-
floating, cottony tufts; branching not dichotomous, arising from
beneath a heterocyst or series of heterocysts Tolypothrix
[ 595 ]
Glossary
Terms Relating to Fresh-water Algae
Abscission: separation of a branch or portion of a thallus by degeneration of
cells at its base, or by constriction.
Achromatic: without color.
Achromatin: the material of the nucleus exclusive of the chromatin.
Acicular: needle-shaped.
Adnate: joined along a relatively broad surface.
Aerobic: using free oxygen in respiration.
Agglutinate, Agglutinated: sticking together; adherent, as with mucilaginous
sheaths.
Akinete: a spore produced from a vegetative cell which has developed a thick
wall about a concentrated food reserve.
Akontae (Akontean): plants in which neither vegetative cells nor reproductive
cells have flagella.
Alveolar: with cavities or pits.
Amoeboid: like an amoeba in locomotion or in nutrition; creeping by pseudo-
odia.
Agari without definite shape.
Anabaenin: a pigment found in the blue-green algal genus Anabaena.
Anaerobic: carrying on respiration without the use of free oxygen.
Anastomose: referring to sheaths, filaments, or thalli which intermittently join
and separate; sometimes joining in such a way as to form a network.
Androsporange, Androsporangium: box-like cell which produces a special spore,
androspore, which develops into a dwarf male plant (Oedogoniaceae ).
Androspore: a spore which gives rise to an epiphytic dwarf male plant (Oedo-
goniales ).
Anisogametes: sex cells of a plant slightly dissimilar in size, shape, or behavior.
Alternation of generations: a life cycle in which both asexual and sexual plants
occur, one giving rise to the other by the production of spores, and by the
fusion of gametes.
Annular: ring-like.
Antapical: posterior; basal; opposite the apex.
Antapical plates: sections of the cell wall of Dinoflagellatae at the posterior pole.
Antheridium: a male gametangium or sex organ.
Antherozoid: a male gamete; sperm, or spermatozoid.
Apex (Apical): forward tip; anterior end.
Apical plates: sections of the cell wall of Dinoflagellatae at the anterior pole.
Apiculate: abruptly tapered to a fine point.
Aplanogametes: non-flagellated gametes.
Aplanospore: non-motile asexual spores, formed one to several in but not the
same shape as a parent cell.
Aplanosporangium: cell which gives rise to aplanospores.
Apposed: paired; opposite in definite relation to one another.
Appressed: pressed together; closely adjoined.
Arborescent, Arbuscular: branched in tree-like fashion; bushy.
Arachnoid: like a web.
[ 596 ]
Arcuate: arched, bow-shaped, sharply crescent-shaped; strongly curved as in
a drawn bow.
Areolate: with openings; with thin areas (areolae), usually circular, in the wall.
Articulate, Articulated: jointed; with segments.
Asexual: referring to reproduction in which spores rather than gametes are used.
Asexual auxospore: a resting stage formed without union of gametes (diatoms ).
Attenuated: narrowed or tapering toward the ends.
Autocolony: colony of cells formed by the division of one or more cells of a
mother colony; or by internal division of a cell to form a miniature colony
(see Pediastrum, Oocystis, Volvox).
Autospore: a small replica of the parent cell formed internally, one or several
together.
Autotrophic: self-feeding; able to manufacture food.
Auxospore: a resting spore formed by some diatoms, either sexual or asexual.
Axial chloroplasts: chloroplasts in the median plane of a cell, arranged along
a median line.
Axis: the central or median plane of a figure, cell, or plant.
Azygote, Azygospore: a spore similar in shape and wall markings to a zygo-
spore (q.v.) but formed without the union of sex cells.
Bacillar: rod-shaped.
Basidia-like: club-shaped.
Basipetalous: developing from apex toward the base.
Benthon: organisms attached on the bottom of an aquatic habitat; deep-water
life.
Biconic: in the shape of two cones with their bases together.
Bifurcate: divided into two portions, or branches, as in the forking of spines
or lobes.
Bilateral: on two sides; arising on two sides; the same on two sides.
Biseriate: in two rows; with two series of cells.
Blepharoplast: small body (the central body) associated with the nucleus; in
some flagellates, the body from which the flagellum arises.
Bulbous: bulb-like, swollen at one end.
Caespitose (or Cespitose): clustered; in fascicles; forming a mat or tangle.
Calose: a substance appearing in the walls of the Siphonales which replaces
cellulose.
Calyptra: a thickening; a thick covering or membrane at the tip of a trichome
or organ (e.g. in Oscillatoria spp., Phormidium spp. ).
Canal: tube; fine channel, as in the wall of diatoms.
Capitate: with a head; swollen at one end, or at both ends.
Capitellate: slightly swollen or enlarged at one end.
Carotene, Carotin: an orange-colored pigment, usually associated with chloro-
hyll.
Gasiberne Carpogonium: female sex organ in the Rhodophyceae.
Carpospore: spore arising from the fertilized egg in some Rhodophyceae.
Cartilaginous: tough but pliable.
Catenate: joined to form a chain.
Caudus: a tail-piece.
Central body: the central region of the blue-green algal cell, which upon
staining shows the presence of chromatin granules; a granule associated
with the nucleus in flagellated organisms.
Central nodule: the thickening on the inner face of the wall of some diatoms.
Centricae: diatoms which are radially symmetrical.
Centrifugal: developing from the center outward, or from a point outward.
[ 597 ]
Centripetal: developing from without inward, or from exterior to interior.
Centrosome, Centriole: a small body, usually lying just outside the nucleus; in
flagellates a granule functioning in the neuromotor system.
Cespitose: See caespitose.
Chitin: a hard substance, C15 Hog O10 Ne, found in skeletons of lower animals
and in cell walls of some algae.
Chloroplast: a body (plastid) in the cell containing chlorophyll as the pre-
dominating pigment.
Chlorococcine tendency: evolutionary trend toward the Chlorococcales in the
green algae (or in other groups) from a solitary motile cell which has
ability to reproduce vegetatively by cell division to a nonmotile type of
ae lawn ania or coenocytic) in which vegetative cell division is not
used.
Chromatophore: a colored body in a cell which has a pigment other than
chlorophyll predominating.
Chromatic: colored.
Chromatin: the material in the nucleus which takes up dyes readily; nuclear
material composing chromosomes.
Chromoplasm: the portion or part of cell content containing pigments, not in-
volving plastids; in Myxophyceae the cytoplasm just within the cell wall
and exterior to the “central body.”
Chromulinad: a type of cell similar to Chromulina which has one flagellum.
Chroococcoidal: in shape or arrangement similar to Chroococcus; cluster of
round cells.
Chrysochrome: brown pigment found in Chrysophyceae.
Cilium (pl., Cilia): fine, hair-like extensions, usually from the outer membrane
of a cell; used in locomotion by ciliated protozoa; fibrils on the flagella of
the Heterokontae.
Cingulum: band within the diatom cell which holds the two overlapping sec-
tions of the wall together.
Circinate: coiled, rolled; twisted.
Cirque: arranged in a circle or nearly so.
Citriform: lemon-shaped.
Clathrate: with openings; intermittent spaces.
Clavate, Claviform: wedge-shaped.
Coalesced, Coalescent: joined, united; grown together.
Coccoid: round; spherical; cells as in Chroococcus, Aphanocapsa.
Coenobe, Coenobium: a colony of cells arranged to form a hollow sphere.
Coenocytic: with many nuclei; a thallus constructed of multinucleate cells;
a thallus in which there are no cross walls.
Collar: narrow neck around the flagellum-opening in a shell or lorica; some-
times a sheath at the base of a bristle or hair.
Colligate: united, joined, as in some species of Spirogyra which have an exter-
nal collar-like piece about the cells at the cross walls.
Colony: a group of individuals, joined together or merely inclosed by a com-
mon sheath or investing material; a group of cells joined together to form
a filament (rarely used in this sense); a cluster of individual plants,
closely associated in growth.
Commensal: referring to two or more species living in close association and
deriving mutual benefits.
Complanate: level, smooth, even, plane.
Concentric: layers or structures with a common center.
[ 598 ]
Confluent: growing into one another; soft sheaths which run together or which
become intermingled.
Conidium: a spore cut off from the tip of a cell, or from a filament.
Connate: pointed; united for a short distance as in the basal portion of branches.
Constricted: pinched in; deeply incised.
Contiguous: near-by, adjoined.
Conjugation: union of gametes from cells or from plants which become joined,
the gamel.s moving together in an amoeboid fashion; literally, a yoking
together.
Contorted: irregularly twisted.
Contractile: able to expand and contract.
Contractile vacuole: cavity in the cytoplasm surrounded by a membrane which
shows pulsating actions, compressing and expanding.
Convolute: rolled together; rolled inward from a margin.
Cordate, Cordiform: heart-shaped.
Coronula: a crown of cells at apex of oogonium in Characeae.
Cortex, Corticating: a layer of cells or filaments which invest or grow around
a central core (cell or filament), forming an inclosing layer (e.g., some
Rhodophyceae, Chara).
Corymb (Corymbose): a flat-topped cluster (especially when sequence of
development is from outside toward the center ).
Costa (Costate): rib (adj., ribbed).
Craticular stage: a condition in diatoms in which successively formed cell walls
nest within one another.
Crenate: with a wavy surface or margin.
Crenulate: finely crenate; with small scallops.
Cuspidate: furnished with a tooth.
Cruciate: cross-like in arrangement.
Cryoplankton, Cryovegetation: plants which live in snow, especially perpetual
snow banks of alpine situations.
Cuneate: wedge-shaped.
Cushion-like: said of a thallus composed of a mound of cells, two to many
layers of cells; parenchymatous.
Cylindrical: elongate and round in cross section with parallel lateral margins.
Cyst: a dormant, vegetative reproductive cell, usually with a heavy wall.
Cystocarp: a structure that develops around the fertilized egg in the Rhodo-
phyceae in which spores (carpospores) are formed.
Cystosome: soft portion of periplast of flagellates in the food-absorbing region.
Cytopharynx: a canal extending back from the anterior opening in flagellates;
narrow part of gullet in euglenoids.
Daughter cells, Daughter segments: cells or portions of thallus that are des-
cended from the same mother cell or parent plant.
Decumbent: growing horizontally but with the segment ascending (c.f. pros-
trate ).
Deliquescent: degenerating; dissolving.
Dendroid: tree-like, branching as in a tree.
Dentate: toothed; with blunt-pointed projections.
Depressed-globose: not quite spherical; like a slightly flattened sphere.
Diastole: period of expansion in action of contractile vacuole.
Diatomaceous earth: grayish-colored silicious deposit of diatom shells.
Diatomin: brown pigment found in diatoms.
Dichotomous, Dichotomy: divided or forked into two parts; forking branches.
Dioecious:“two households”; with male and female organs on separate plants.
[ 599 ]
Diffluent: flowing off; dissolving away.
Diploid: referring to nucleus with double number of chromosomes; a generation
of plant life cycle before reduction division (cf. haploid).
Disarticulate: unjointed; with segments separated.
Disc (Discoid): a circular, flat body; a plate.
Dissepiment: a cross partition; a cross wall.
Distal: referring to the forward end; opposite from basal.
Distromatic: occurring in two layers, or at two levels.
Divaricate: widely separating; spreading.
Diverging: extending from a common point in different directions.
Dolioform: barrel-shaped.
Dwarf male: a 1-celled or few-celled male plant epiphytic on the female,
usually on or near the oogonia.
Echinate: spiny.
Egg: female gamete; non-motile heterogamete.
Emarginate: a margin which is not even, but notched or with concavities.
Endocellular: within the cell.
Endogenous: arising from within.
Endophyte (Endophytic): plant living within another plant but not neces-
sarily parasitic.
Endospore: a spore formed within a cell; a spore cut off from the tip of a
protoplast as in Chamaesiphon.
Endozoic: living within an animal but not necessarily parasitic.
End piece: the unsheathed tip of a flagellum; a tail piece.
Entire: smooth, not toothed or roughened.
Envelope: a sheath or mass of mucilage which incloses a cell or colony.
Epicone: the upper or anterior half of a dinoflagellate cell.
Epiphyte (Epiphytic): plant growing on another plant but not necessarily
parasitic.
Epitheca: the part of the cell wall of a dinoflagellate above the transverse
furrow.
Epivalve: the upper or larger of the two parts of the wall of diatom cells;
sometimes the upper part of dinoflagellate cells.
Epizoic: attached to or growing on animals.
Erect oogonium: oogonium (in the genus Bulbochaete) borne at the end of
a suffultory cell (q.v.) that has been divided by a transverse wall.
Euplankton: true plankton; open-water drifting organisms.
Eutrophic: referring to older, shallow lakes; highly productive.
Evanescent: disappearing, vanishing, especially with advanced age.
Evection: to set aside or to push one part above another.
Excentric (or Eccentric): off center.
Exospore: the outer membrane of a zygospore wall.
Eye-spot: pigment-spot; granule which is sensitive to light and usually dark
red in color; found in some swimming spores or in motile vegetative cells.
False branch: a branch formed by a slipping to one side of a section of a fila-
ment; a branch not formed by lateral division of a cell.
Family: an aggregation of cells or of similar plants.
Fascicle ( Fasciculate ): a bundle or cluster.
Fastigiate: narrowed to a point.
Fenestrate (Fenestration): windowed; with openings.
Fibrils (Fibrillate, Fibrillose ):fine fibers; slender strands.
Filament: a linear arrangement of cells; thread of cells, together with sheath
(Myxophyceae ).
[ 600 |
Filiform: thread-like.
Fission: division of a cell by splitting to form two, not necessarily equal, parts;
cell division without mitosis.
Flaccid: soft, drooping, not rigid.
Flagellum: a stout, whip-like organ of locomotion which arises within the cell.
Flagelliform: whip-shaped.
Flange: a longitudinal ridge extending vertically from a cell wall.
Flexuous: pliable; not firm or rigid.
Floccose, Flocculent: cottony, or wooly; matted.
Floridean starch: a carbohydrate food reserve in the Rhodophyceae.
Foliaceous, Foliose: like a leaf.
Frond: a flat, leaf-like plant; a foliaceous thallus.
Frustule: the shell of diatoms.
Fusiform: an elongate figure broadest in the middle and tapering at each end;
spindle-shaped.
Gametangium: a gamete-producing cell; sex organ.
Gamete: a sex cell, male or female reproductive cell.
Gelatinous envelope: a sheath or investment of mucilage-like substance.
Geniculate: with knee-bendings.
Germling: young plant developed from a spore or zygote.
Gibbous: swollen in a regular curve.
Girdle: a band or belt, usually median; part of the structure just within the
wall, and lateral in the cell, which holds the valves of diatoms together.
Girdle view: a lateral or side view of a diatom, showing the overlapping of the
two wall sections.
Glaucous: grayish-green; green with a whitish overcast or ‘bloom.’
Glomerate: in compact clusters.
Glomerule: a small compact cluster.
Glycogen: a white carbohydrate, amorphous, similar to starch; a food reserve.
Gonidium: a spore-like, thick-walled reproductive cell (see akinete ).
Gonimoblasts: short filaments developing from the zygote in certain Rhodo-
phyceae which cut off spores (carpospores ) at their tips.
Granulose: furnished with granules.
Gregarious: growing in clusters or in close associations; not solitary.
Gullet: an opening through the membrane at anterior end of flagellates
(euglenoids ).
Gynandrosporous: in Oedogoniaceae, a condition in which androspores (spores
which produce male plants) are developed in the same filament in which
oogonia (female organs ) occur.
Gypsum: granules of calcium sulphate found in the cells of some desmids.
Haematochrome: a red pigment apparently functioning as a light screen,
appearing occasionally in green algae, sometimes permanently present.
Haploid: containing the half number of chromosomes (nucleus with the 1-n
number); referring to a generation in the life history following reductive
division.
Haplontic: a haploid or 1-n generation; referring to a cell containing the re-
duced number of chromosomes.
Hapteron (pl. Haptera): an anchoring, finger-like organ at the base of a young
lant.
Heleoplanktone floating organisms in a small, shallow pond.
Helotism: a form of symbiosis; two different species in close association
(lichens ).
[ 601 ]
Hemicellulose: a hard carbohydrate somewhat similar to cellulose in walls of
some algae; more common in cell walls of higher plants.
Heterocyst: a specialized cell in some filamentous Myxophyceae which is usually
larger than and a different shape from the vegetative cells.
Heterogametes: sex cells unlike in size, shape, and behavior.
Heterothallic: from two different thalli; of reproductive structures or cells
borne on different parents.
Heterotrophic: obtaining food in soluble or particulate form; not photosynthetic.
Heterotypic division: reductive division of a nucleus; segregation of chromo-
somes.
Hirsute: hairy.
Holdfast cell: the basal cell of a filament modified to form an attaching organ.
Holophytic: obtaining food by photosynthesis.
Holozoic: ingesting food like an animal.
Homothallic: from similar thalli; of gametes from the same parent.
Homotypic division: nuclear division (mitosis) involving a splitting of chrom-
osomes; the chromosome division immediately following first meiotic
division.
Hormogonium, Hormogone: a fragment of a filament; a short section broken
away from a mature trichome (Myxophyceae).
Hormospore: a vegetative spore-like body formed from a short section of a
filament that becomes invested by a thick membrane.
H-shaped pieces: sections formed when a filament of cells dissociates; the H-
shaped pieces formed as a result of the fact that cell walls are in two
pieces which overlap in the midregion, the line of cleavage being here
rather than at the cross walls of the filament.
Hyaline: colorless; transparent.
Hypocone: the lower part or posterior half of a dinoflagellate below the me-
dian girdle.
Hypotheca: the lower half of the cell wall of a dinoflagellate below the median
irdle.
H Weccilce: the lower or smaller of the two parts of a diatom cell wall.
Hypha, Hyphal filaments: threads which inclose the central, axial filament in
some Rhodophyceae (Lemanea).
Hypnospore: small, thick-walled, asexual spore; especially the spores formed
underground in Botrydium.
Idioandrosporous: having androspores formed in filaments separate from those
in which the female organs (oogonia) are produced (e.g., in Oedogonium).
Imbricate: overlapping; joined in an overlapping series.
Incised: cut, with narrow slits.
Indurate: hard.
Inferior pore: a pore in the wall in the lower part of an oogonium (Oedogon-
iaceae ).
Initial cell: cell which generates other cells, or which gives rise to tissue.
Inner fissure: the inner part of the raphe in the pennate diatoms.
Integument: a covering, sheath, or envelope.
Intercalary: appearing between, inserted (as between cells), rather than ter-
minal or marginal.
Intercalary bands: bands which help to hold the two valves of the diatom
cell together.
Interpolate: to place between.
Intestiniform: shaped like an intestine; tubular.
Intravitam: within living tissue; e.g., to stain a living cell.
[ 602 ]
Intricate: tangled.
Investment: an inclosing membrane or envelope.
Isochrysid: cells bearing two flagella of equal length in Chrysophyceae.
Isodiametric: having diameters equal.
Isogamous: sex cells similar to one another in size, shape, and behavior.
Isokontae (Isokontean): plants which have vegetative or reproductive cells
equipped with flagella (usually 2) of equal length.
Isthmus: narrow part of the desmid cell connecting two semicells (cell halves).
Karyokinesis: division of the nucleus; segregation of nuclear material in cell
division.
Keel: a flange on the valve of some diatoms.
Laciniate: torn; with a cut or lacy margin, or lace-work surface.
Lacuna (Lacunate): an opening (with spaces).
Lageniform: flask-shaped.
Lamellate, Lamellated, Lamellose: layered, with layers.
Laminate: plate-like.
Lanceolate: lance-shaped; long and narrow with subparallel margins but
tapered at the apex.
Lateral conjugation: sexual reproduction involving a joining to two contiguous
cells in the same filament (e.g., in some species of Spirogyra).
Lenticular: lens-shaped; with two convex surfaces.
Leucosin: a white food reserve material found in most Heterokontae.
Limnoplankton: drifting organisms in lake water.
Littoral: in shallow water near shore; on the shore.
Longitudinal furrow: a groove in dinoflagellates lying parallel with the long
axis, at right angles to the transverse furrow.
Loculiferous: with small chambers or compartments.
Lorica: a shell or case built around but separate from the living protoplast.
Lumen: a cavity, especially the space left in a cell after spores or gametes have
escaped.
Lubricous: slippery.
Lunate: crescent-shaped; moon-shaped.
Macrogamete: the larger of two sizes of swimming gametes (e.g., Stichococcus).
Macrandrous: having male plants that are as large or nearly as large as the
female plants (Oedogoniaceae ).
Macrozoospores: the larger of two sizes of zoospores (e.g., Ulothrix).
Mammillate: with nipple-like protuberances.
Marl: calcareous deposit formed by some algae, especially Chara.
Matrix: investing or surrounding matter, especially mucilaginous material sur-
rounding cells.
Median constriction: a pinched-in or narrowed region in central portion of cell
or thallus.
Membranous, Membranaceous: like a membrane, a thin layer.
Meristematic: referring to cells with the ability to divide rapidly.
Mesospore: middle one of three layers in the wall of zygospores.
Metabolic: changeable in form, varying in shape from time to time (e.g.
Euglena).
Microgamete: the smaller of two sizes of swimming gametes (e.g., Stichococ-
cus ).
Microspores: minute, spore-like bodies formed by some diatoms, questionably
sexual or asexual.
Microzoospores: smaller of two sizes of zoospores in Ulothrix; spores which
swarm for 2 to 6 days without germination.
[ 603 ]
Mitosis (Mitotic): nuclear division by formation of spireme thread and chrom-
osomes.
Moniliform: resembling a string of beads.
Monaxial: with one axis or with one row of cells.
Monoecious: “of one household”; with both male and female sex organs on the
same plant.
Monosiphonous: formed of a single tube or filament, without cross walls.
Monospores: asexual spores cut off from tips of branches, or from vegetative
cells (e.g., some Rhodophyceae ).
Monostromatic: referring to a prostrate thallus, one cell in thickness.
Mother cell: the cell which divides itself (often internally ) into daughter cells.
Motile: able to move; swimming.
Multicellular: composed of many cells.
Multiaxial: with more than one axis; with more than one row of cells.
Multinucleate: with many nuclei.
Multiseriate: with more than one row of cells; with many filaments.
Nannandrous: with dwarf male plants, minute male filaments growing epiphyti-
cally on the female plant (Oedogoniaceae ).
Nannoplankton: very minute aquatic organisms (see plankton).
Nannospores: very small vegetative cells arising from rapid cell division.
Napiform: turnip-shaped.
Naviculoid: like Navicula; like a little boat.
Necridium: a dead cell; a somewhat differentiated cell in some filamentous
Myxophyceae which permits fragmentation to occur readily.
Nekton: organisms capable of swimming against water currents.
Neuromotor apparatus: the bodies and fibrils interconnecting flagella and at-
taching them to the centriole and the nucleus (e.g., euglenoids ).
Neutral spore: a vegetative spore arising from increased cell division in certain
Rhodophyceae.
Nodule: a small knob.
Nonparticulate: referring to substances in solution.
Obconic: cone-shaped with the broader end foremost.
Obovoid: inversely ovoid; with the broader end anterior or outermost.
Obpyriform: inversely pear-shaped, with the broader end anterior or outermost.
Ochromonad: a type of cell similar to Ochromonas (with two flagella.of un-
equal length).
Ocelli: raised thickenings on the walls of diatoms.
Ocrea: a sheath; a layered envelope.
Oligotrophic: referring to younger, deep lakes; poor in production.
Ontogeny (Ontogenetic): life history of an organism.
Oogamy: reproduction involving gametes of which one is an egg.
Oogone, Oogonium: one-celled female reproductive organ, usually containing
a single egg.
Oolith: a stone-like concretion involving a fossil surrounded by deposits of
calcareous material.
Oospore: a thick-walled spore formed from a fertilized egg.
Operculum: a lid or cap.
Orbicular: spherical.
Orbiculate: circular in outline.
Oval: an elongate figure with convex margins and equally rounded at the ends.
Ovoid: shaped like an egg; an elongate figure with unequal curvature at the
poles, one being broader than the other.
Ovate: see oval.
[ 604 |
Outer fissure: the upper part of the raphe (q.v.) in pennate (bilaterally sym-
metrical) diatoms.
Packet: compact cluster or aggregate of cells, often cubical.
Palmella stage: a condition resembling Palmella, in which a motile cell has
lost organs of locomotion, become quiescent, and undergone division to
form clumps of daughter cells encased in mucilage.
Palmelloid: similar to Palmella; forming clumps of mucilage-encased cells.
Panduriform: fiddle-shaped; an elongate figure, broadest at the anterior end
and with concave lateral margins.
Papilla (Papillose): a small nipple-like swelling (adj.: bearing papillae ).
Paramylon: a solid carbohydrate food reserve formed by certain euglenoids.
Parenchymatous: cushion-like; composed of a mound of cells.
Parietal: lying along the wall; peripheral in the cell.
Parthenospore: a zygote-like spore produced from a single gamete which de-
velops a thick wall.
Patent oogonium: oogonium (in Bulbochaete) borne on a division of the
suffultory cell (q.v.) that has been cut off obliquely from the lower cel
rather than by a transverse wall; free; free spreading.
Pectin, Pectose: gelatinous substance (carbohydrate) found in the wall of
many algae.
Pedicel: a stalk or stem, often delicate and short.
Pelagic: floating organisms, especially in the ocean; surface organisms.
Pellicle: a thin membrane or sheet.
Pellucid: translucent, clear.
Penicillate: brush-like.
Pennatae: diatoms which are bilaterally symmetrical.
Pericentral cell: a cell (one of several) inclosing a central cell or filament.
Peridinin: a reddish pigment found in some dinoflagellates.
Periphyton: organisms attached at the water level to aquatic plants.
Periplast: the bounding membrane, especially the cell membrane of euglenoids.
pH: relative amount of free hydrogen ions; indicator of acidity or alkalinity.
Pharyngeal rods: bodies lying parallel with the gullet (e.g., Peranema).
Phototactic: movement or orientation with respect to light stimulus.
Phycochrysin: brown pigment found in Chrysophyceae (chrysochrome ).
Phycocyanin: a blue pigment in solution in cells of Myxophyceae and some
Rhodophyceae.
Phycoerythrin: red pigment in Rhodophyceae and some Myxophyceae.
Phycopyrin: brownish-red pigment in some dinoflagellates.
Phylogeny: racial development: racial history.
Pigment-spot: See eye-spot.
Piliferous, Pilose: hairy.
Placoderm desmid: desmid usually constricted in the midregion, with wall in
two sections.
Plakea: plate of cells formed by successive divisions from mother cell.
Plane: smooth and even, not folded.
Planoconvex: with convex surface opposite a flat surface.
Planogamic heterogamy: condition of having gametes of different size, motile
and non-motile.
Plankton (Planktonic): floating organisms unable to swim against currents,
drifting.
Plasmodium: naked protoplasm as in slime molds.
Plastid: any one of several kinds of bodies in the cytoplasm of a cell.
Plicate: folded.
[ 605 ]
Plurilocular gametangium: closely arranged cluster of cells, each producing a
gamete.
Polar: at the end of an axis.
Polar nodule: the body on the inner wall at the ends of some diatoms.
Polygonal: with many sides.
Pore: a hole or opening in a wall or membrane; mucilage pore; pore for en-
trance of antherozoid, etc.
Postcingular plates: sections of the wall of dinoflagellates lying between the
median girdle and the antapical plates; posterior plates.
Precingular plates: sections of the wall of dinoflagellates lying between the
median girdle and the apical plates; anterior plates.
Processes: extensions; lobes, arms, etc.
Proliferate: to develop a new thallus or branches by vegetative cell division.
Prostrate: lying down; horizontal.
Protonema; Protonema stage: prostrate filaments arising from germination of
spore, sometimes giving rise to upright branches.
Protophyte, Protophyta: simplest of plants; often referring to organisms with
both plant and animal-like characteristics.
Protoplast: the living material (protoplasm) of a cell.
Psammon: microorganisms inhabiting beaches or sandy shoals.
Pseudocilia: false cilia; hair-like extensions similar to flagella in shape but not
used for locomotion.
Pseudofilament:a thread of cells incidentally arranged in a linear series; not a
true filament.
Pseudoparenchymatous: resembling a mound of cells but actually constructed
of closely grown filaments.
Pseudoraphe: a false raphe (q.v.); a clear median area in the valves of some
diatoms which forms a line resembling a raphe.
Pseudopodium: a false foot; a root-like extension of protoplasm usually in-
volved in locomotion (see Chrysomoeba).
Pseudovacuoles: false vacuoles; pockets of gas or mucilage in the cytoplasm
resembling vacuoles, and usually light-refracting (Myxophyceae).
Pulsating vacuoles: vacuoles which contract suddenly and expand slowly.
Pulsule: non-contracting vacuole (as in dinoflagellates).
Pulverulent: finely granular; powdery.
Pulvinate: cushion-shaped.
Punctate: with minute points or dots; with cylindrical pores.
Pyramidal: in the shape of a pyramid.
Pyrenoid: a proteid granule which collects starch, either within a chloroplast,
on its surface, or free within the cytoplasm.
Pyriform: pear-shaped, with narrow end foremost.
Quadrate: square; arranged to form a rectangle.
Quadripartition: division to form four units.
Raceme: a cluster of reproductive structures which mature inwardly from
without, the youngest structure being in the center or at the top of the
cluster; racemose (adj.), arranged like a raceme.
Radial: along the radius; radiating.
Raphe: a fissure, slit, or channel in the wall of some diatoms.
Rectilinear: arranged in straight rows in two directions.
Reniform: bean-shaped; kidney-shaped.
Repand: referring to cells having the lateral walls concave or undulate.
Replicate: folded, especially the end walls of some species of Spirogyra.
Reservoir: posterior, enlarged portion of gullet in flagellates (euglenoids ).
[ 606 |
Reticulate: netted; arranged in a net-work; covered with thickenings in the
form of a net.
Retuse: rounded at the apex but with an incision (as in heart-shape ).
Rhabdosomes: small rods in the periphery of cells in some dinoflagellates.
Rhizoidal: root-like, resembling rhizoids.
Rhizoplast: fibril connecting flagellum base with centrosome; part of the neu-
romotor apparatus in flagellated organisms.
Rhizopodal: moving as an amoeba.
Rhizopodal tendency: evolutionary trend from a swimming cell to a condition
in which the organism is amoeboid.
Rhomboid: a parallelogram with oblique angles and adjacent sides unequal.
Rostrate: with a beak.
Rostrate-capitate: with a beak which has a swollen tip.
Rugose: roughened, as with ridges and furrows.
Saccate: like a sac; balloon-shaped.
Saccoderm desmids: desmids unconstricted in the mid-region and with the
wall in one piece (cf. placoderm desmids ).
Saggitate: arrow-shaped.
Saprophyte: organism that obtains food from dead organic matter.
Sarciniform: in the shape and arrangement of a cubical packet.
Scalariform: ladder-like, referring to conjugation by tubes connecting two
filaments.
Scale-like: like a small husk or membrane.
Schizophycean phycoerythrin: red pigment in the Myxophyceae.
Scrobiculate: pitted, usually with round, shallow depressions.
Scytonemin: a pigment found in the sheath of some Scytonema.
Semi-anaerobic: see anaerobic.
Semicell: cell-half of a desmid.
Semilunar: somewhat crescent-shaped.
Septa: a cross wall or partition.
Seriate: in a linear sequence or series.
Seta: a hair or bristle; sometimes a tail-piece.
Setiferous: bearing a seta or hair.
Sexual auxospore: spore formed by union of gametes, or from parthenogenetic
development of gametes (diatoms).
Sheath: a covering, an envelope, usually relatively thin and composed of
mucilage.
Sigmoid: like the letter S.
Silicious: containing silicon.
Sinus: the incision of a desmid cell in the midregion; any conspicuous invag-
ination.
Siphon: organ involved in the digestive apparatus of some flagellates.
Siphonaceous: referring to a tubular thallus which has no cross walls (e.g.,
Vaucheria).
Spatulate: elongate, gradually enlarged and bluntly rounded at one end.
Spermatia: cells acting as male gametes; non-motile male cells, as in Rhodo-
phyceae.
Spermatozoid: a male gamete.
Spermocarp: one of the investing cells developed about the fertilized egg
(Coleochaete ).
Spongiose: like a sponge; like a soft, thick mat.
Spicules: needle-like scales or hard bristles.
Spinescence: spines; spine arrangement.
[ 607 ]
Sporangium: a cell in which spores are produced (often zoospores ).
Spore: a one-celled, asexual reproductive element, with or without a wall.
Statolith: granule functioning as a balancing organ relating the cell to gravity.
Statospore: spore smaller than the parent cell, formed within the shell (frus-
tule) of diatoms.
Stauros: a stake; a stout, pole-like extension; an external central nodule in
some diatoms.
Stellate: star-shaped.
Stephanokontae: plants which have motile reproductive cells furnished with
a crown of flagella.
Stigma: the red granule or group of granules making up the light-sensitive
spot in zoospores and flagellates.
Stipe: a stalk.
Stratum: a layer.
Striae: delicate, long, narrow markings.
Stroma: supporting tissue or mass of cells serving as a base for upright branches
or other organs.
Sub—-: slightly or nearly, as subglobular; under; beneath.
Subbiconic: nearly or somewhat double cone-shaped.
Subhexagonal: somewhat six-sided.
Subparenchymatous: somewhat cushion-like; approaching the mound-like ar-
rangement of cells, in two or more layers.
Subpyriform: somewhat pear-shaped.
Suffultory cell: a cell resulting from the division of a vegetative cell, the
upper segment of which forms an oogonium, the lower segment a some-
what enlarged suffultory cell.
Sulcus: the longitudinal furrow in dinoflagellates.
Superior pore: a pore in the upper part of an oogonium (Oedogoniaceae ).
Supramedian: slightly above the median plane.
Suture: furrow or groove; trough between plates in wall of dinoflagellates.
Symbionts: two dissimilar organisms living together in close association.
Symbiotic: a condition in which two different organisms live together.
Systole: contraction period in action of pulsating vacuoles.
Tangential: section or cut made at right angles to the radius.
Tegument: a sheath or envelope.
Terebriform: twisted or twist-hooked, augur-shaped.
Test: an external shell inclosing the protoplast (e.g. Trachelomonas ).
Tetrad: four cells formed by two divisions from a spore mother cell.
Tetrasporine tendency: evolutionary trend in green algae from a motile uni-
cell through a palmelloid condition to a Tetraspora-like expression, and
then to a filamentous form.
Thalloid: like a plant body which has no roots, stems, or leaves.
Thallus: a plant body in which there is little or no differentiation of cells to
form tissues.
Tie cells: cells in the thallus of some red algae which connect peripheral cells
to a central axis.
Tomentose: covered with numerous fine hairs.
Torulose: twisted; flexuous, as in irregularly spiralled species of Anabaena.
Transverse: across the short diameter.
Transverse furrow: groove extending (at least partly) around the dinoflagel-
late cell in the midregion.
Trapezoid: a plane figure which has two parallel sides.
Trichites: silicious spicules; a tuft of bristles.
[| 608 ]
Trichocyst: an organelle in the cell which throws off a fibril; a stinging thread.
Trichogyne: narrow extended part of female sex organ (carpogonium) in the
Rhodophyceae.
Trichome: a hair; a thread of cells without the investing sheath in Myxophyceae.
True branching: branched by lateral division of a cell in a main filament.
Truncate: flat at the top; flatly rounded.
Tubercle (Tuberculate): small raised thickenings on the wall, or at the base
of spines.
Tychoplankton: floating or free-living organisms in shallow water of a lake
intermingled with miscellaneous vegetation, usually near shore.
Travertine: a deposit of chalk-like calcareous material.
Umbonate: with a cone-shaped protrusion.
Undulate: wavy.
Uncinate: with a hooked apex.
Unilateral: on one side; arising from one side only.
Unilocular sporangium: a solitary, one-celled spore-producing organ.
Uniseriate: arranged in a single row or series.
Uninucleate: with one nucleus.
Utricle: a small sac; a tubular bag or vesicle.
Vacuole: a space in the cytoplasm filled with cell sap, sometimes containing
granules.
Valves: the two parts of the wall of diatoms, one of which is larger and fits
over the smaller as a lid; the two parts of a dinoflagellate cell.
Valve view: view from the top or bottom of a diatom cell so that the broader
surface of the valve is seen.
Ventricose: bulged or swollen on one side.
Vermiform: worm-like.
Verrucae: short, stout projections, smooth or armed with teeth.
Verrucose: warty.
Vertical canals: canals which connect both outer and inner fissures of the
raphe (q.v.) in one part of the diatom cell with the fissures in the other
part.
Vesicle: minute sac or cavity.
Volvocine tendency: evolutionary trend in green algae from a single motile
cell toward simple colonies, and to colonies containing differentiated or
specialized cells.
Water bloom: a conspicuous and abundant growth of planktonic algae, some-
times appearing suddenly, often forming a surface scum.
Xanthophyll: yellow pigment associated with chlorophyll.
Zonate: with bands; with concentric layers.
Zoospore: a motile, animal-like spore without a cell wall.
Zygospore: a thick-walled resting spore resulting from the union of gametes.
Zygote: a fertilized egg; a cell resulting from the union of gametes.
[ 609 |
Bibliography
+ Important reference work
* Deals with Michigan and Wisconsin algae
ACKLEY, ALMA B. 1929.” New species and varieties of Michigan algae. Trans.
Amer. Microsc. Soc., 48: 302-309; Pls. 35, 36. 1929a.* The algae of Mich-
igan. Doctoral thesis, Ohio State University. Abstract. 1930.* The algae of
Michigan. Doctoral thesis, Ohio State University. 1932.% Preliminary report
on Michigan algae, exclusive of desmids and diatoms. Pap. Mich. Acad. Sci.,
Arts, and Letters, 15(1931): 1-49.
AcTON, ELizaBETH. 1914. Observations on the cytology of the Chroococcaceae.
Ann. Bot., 28: 434-454; Pls. 33,34. 1916. On the structure and origin of
“Cladophora balls.” New Phytol., 15: 1-10; Figs. 1-5.
Acarpu, C. A. 1810. Dispositio algarum Suecicae, Part I. Lund. 1812. Dis-
positio algarum Suecicae, Parts II and II. Lund. 1812-1816. Algarum
decades, I-IV. Lund. 1817. Synopsis algarum Scandinaviae, adjecta dis-
positione universali algarum. 185 pp. Lund. 1824. Systema algarum, Vol. I.
Lund. 1827. Aufzahlung einiger in den Ostreichischen Landern gefundenen
neuen Gattungen und Arten von Algen, nebst ihrer diagnostik und _bei-
gefiigten Bemerkungen. Flora, 10: 625-640. 1828. Species algarum, Vol. 2.
Lund. 1828-1835. Icones algarum Europaearum. Leipzig.
Acarpu, J. G. 1842. Algae maris Mediterranei et Adriatici. Paris. 1848. Nya
Alger fran Mexico. Oefv. Kongl. Sv. Vet.-Akad. Forhandl., 4(1847); 5-17.
1899. Analecta algologica. Observationes de speciebus algarum minus cognitis
earumque dispositione. Continuatio V. Lund.
AntstroM, E. H. 1936.* The deepwater plankton of Lake Michigan, exclusive
of the crustacea. Trans. Amer. Microsc. Soc., 55: 286-299. 1937.* Studies
on variability in the genus Dinobryon (Mastigophora). Ibid., 56: 139-156.
AutstroM, E. H., and Tirrany, L. H. 1934.* The algal genus Tetrastrum.
Amer. Jour. Bot., 21: 499-507; Figs. 1-36.
ALExENKO, M. A. 1888. Précis des algues chlorosporées des environs de Khar-
kow. Trav. Soc. Nat. Univ. Imp. Kharkow, 21: 141-278. 1891. Matériaux
pour servir a la flore des algues du gouvernement de Poltava. Ibid., 25:
47-88. 1894. Flore algues des maris et des tourbes de la vallée du Dnieper
dans les limites du gouvernement de Poltava. Ibid., 27: 59-118. 1895.
Matériaux pour servir a la flore des algues du gouvernement de Kharkow.
Ibid., 28: 81-132.
ALLEGRE, CHARLES, and JaHNn, T. L. 1943. A survey of the genus Phacus
Dujardin (Protozoa): Euglenoidina. Trans. Amer. Microsc. Soc., 62: 233-
244; Pls. 1-3.
ALLEN, T. F. 1880. The Characeae of America, 1-2: 1-14, Pls. 1-6. Boston.
1882. Development of the cortex in Chara illustrated by a series of American
species. Bull. Torr. Bot. Club, 9: 37-47. 1883. Notes on the American species
of Tolypella. Ibid., 10: 109-117. 1888-1896.+ The Characeae of America.
Pls. 1-27. New York. 1900. Three new Charas from California. Bull. Torr.
Bot. Club, 27: 299-304.
[ 610 J
Axuison, F. E., and Morris, H. J. 1930. Nitrogen fixation by blue-green algae.
Science, 71: 221-223.
AutorcE, P., and LeFevre, M. 1925. Algues de Sologne. Bull. Soc. Bot. France
(Session Extraord., Sologne, 1925), 72(Suppl.): 123-150. (This paper is
sometimes to be found bound with Vol. 77, 1930. Published bibliographies
occasionally cite the latter, rather than the former, volume of this journal,
giving either 1930 or 1931 as the date of publication. )
ALTEN, H. von. 1910. Beitrage zur Kenntnis der Algenflora der Moore der
Provinz Hannover. Hannover Jahrb. Nat. Ges., 59: 47-69.
ANDERSON, Emma N., and WaLKER, Expa R. 1920. An ecological study of the
algae of some sandhill lakes. Trans. Amer. Microsc. Soc., 39: 51-85; Figs.
1-17.
AnpERSSON, O. F. (O. Borge). 1890. Bidrag till kannedomen om Sveriges
Chlorophyllophyceer. I. Chlorophyllophyceer fran Roslagen. Bih. Kongl. Sv.
Vet.-Akad. Handl., 16, Afd. 3, (No. 5): 1-19.
ANpREESEN, H. 1913. Beitrag zur Kenntnis der Physiologie von Scenedesmus
acutus Meyen. Inaug. Diss. Kiel.
Arcuer, W. 1861. In A. Prichard, A history of infusoria including the Des-
midiaceae and Diatomaceae, 4th ed., London. 1866. [Remarks before
meeting of Dublin Microscopical Club, May, 17, 1866]. Quart. Jour.
Microsc. Sci., 14 (Vol. 6, n. s.): 268-272. 1867. On the conjugation of
Spirotaenia condensata (Bréb.) and of Spirotaenia truncata (Arch.). Ibid.,
7: 186-193; Pl. 8, Figs. 1-3. 1868. [No title]. Ibid., 8: 65. 1872. The genus
Tetrapedia (Reinsch) with two new forms. Grevillea, 1: 44-47. 1872a. Notice
of the genus Tetrapedia (Reinsch) and of two kindred new forms. Quart.
Jour. Microsc. Sci., 12(n.s.): 351-366. 1874. Algae and Rhizopoda from the
hot springs of Azores. Ibid., 16: 107. 1874a. Notes on some collections made
from Furnas Lake, Azores, containing algae and a few other organisms. In
J. D. Hooker, Contributions to the botany of the expeditions of H. M. S.
“Challenger.” Jour. Linn. Soc. Bot., 14: 328-340. 1877. New species of
Oocystis. Quart. Jour. Microsc. Sci., 17(n.s.): 104-105.
Antari, A. 1913. Zur Physiologie der Chlamydomonaden. Versuche und
Beobachtungen an Chlamydomonas Ehrenbergii Gorosch. und verwandten
Formen. Pringsh. Jahrb. f. Wiss. Bot., 52: 410-466.
Arwipsson, TH. 1938. Ueber Asterocytis, Astrocystis und Asterocystis. Bot.
Notiser, 1938: 190-192.
Atkins, W. R. G. 1923. The phosphate content of fresh and salt waters in its
relationship to the growth of the algal plankton. Jour. Marine Biol. Assoc.,
18: 119-150.
Arxins, W. R. G., and Harris, G. T. 1924. Seasonal changes in the water and
heleoplankton of fresh-water ponds. Sci. Proc. Roy. Dublin Soc., 18(n. s.):
1-21 (reprint).
Arxinson, G. F. 1890. Monograph of the Lemaneaceae of the United States.
Ann. Bot., 4: 177-229; Pls. 7-9. 1931. Notes on the genus Lemanea in
North America. Bot. Gaz., 92: 225-242.
ATWELL, C. B. 1889. A deep-water Nostoc. Bot. Gaz., 14: 991-292.
AvERINTZEV, S. 1899. Zur Kenntnis der Protozoen-Fauna in der Umgebung
von Bologoje. Trav. Soc. Imp. Natur. St. Pétersb., 30, Lvr. 1, No. 6: 238-251.
Bacu, E. B. 1907.* The Characeae of Michigan. Pap. Mich. Acad. Sci., Arts,
and Letters, 9: 126.
BacuMann, H. 1908. Vergleichende Studien iiber das Phytoplankton von Seen
Schottlands und der Schweiz. Arch. f. Hydrobiol. u. Planktonk., 3: 1-91;
Figs. 1-12, I-XI. 1911. Das Phytoplankton des Siisswassers mit besonderer
[ 611 ]
Beriicksichtigung des Vierwaldstittersees. Mitt. Naturf. Ges. Luzern, 6:
1-213. 1920. Merismopedia Trolleri Nov. Spec. Zeit. f. Hydrol., 1; 350. 1923.
Charakterisierung der Plankton-vegetation des Vierwaldstattersees mittels
Netzfangen und Zentrifugenproben. Mitt. Naturf. Ges. Basel, 35: 148-167.
1928. Das Phytoplankton der Pioraseen nebst einigen Beitragen zur Kenntnis
des Phytoplanktons schweizerischer Alpenseen. Zeit. f. Hydrol., 4: 50-103.
Baitey, J. W. 1841. A sketch of the infusoria, of the family Bacillaria, with
some account of the most interesting species which have been found in a
recent or fossil state in the United States. Amer. Jour. Sci. and Arts, 41:
284-305. 1847. Notes on the algae of the United States. Ibid., 3 (Ser. 2):
80-85, 399-403. 1848. Continuation of the list of localities of algae in the
United States. Ibid., 3(Ser. 2): 37-42. 1851. Microscopical observations
made in South Carolina, Georgia and Florida. Smiths. Contrib. Knowledge,
2(Art. 8): 1-48; Pls. 1-3. 1855. Notes on new species and localities of
microscopical organisms. I—XIV. Ibid., 7, Art. 3: 1-15.
Baker, W. B. 1926. Studies in the life history of Euglena. I. Euglena agilis
Carter. Biol. Bull., 51: 321-362; Pls. 1,2, Figs. A, B.
Batpwin, H. B., and Wuuepte, G. C. 1906. Observed relations between dis-
solved oxygen, carbonic acid and algal growths in Weequahic Lake, N. J.
Rep. Amer. Publ. Health Assoc., 32: 167-182.
Bearps.ey, A. E. 1901. Notes on Colorado protozoa, with descriptions of new
species. Trans. Amer. Microsc. Soc., 23: 49-59; PI. 11.
Bennett, A. W. 1886. Freshwater algae (including chlorophyllaceous pro-
tophyta) of the English Lake District; with descriptions of twelve new
species. Jour. Roy. Microsc. Soc. 1886: 1-15. 1888. Fresh-water algae
(including chlorophyllaceous protophyta) of the English Lake District. IL
With descriptions of a new genus and five new species. Ibid., 1888: 1-6.
1890. Freshwater algae and Schizophyceae of Hampshire and Devonshire.
Ibid., 1890: 1-10. 1892. Freshwater algae and Schizophyceae of South-west
Surrey. Ibid., 1892: 4-12.
Bercguist, S$. G. 1936. The Pleistocene history of the Tahquamenon and Man-
istique drainage region of the northern Peninsula of Michigan. Mich. State
Dept. Conserv., Publ. 40( Geol. Ser., 34): 1-137.
BerkELEY, M. J. 1833. Gleanings of British algae; being an appendix to the
supplement to English Botany. London.
BERKELEY, M. J., and Harvey, W. H. 1855-1859. In J. D. Hooker. The botany
of the antarctic voyage. Part HI. Flora Tasmaniae.
BERNARD, C. 1908. Protococcacées et desmidiées d’eau douce récoltées 4
Java. Dépt. Agric. Ind. Néerland. Batavia. Pls. 1-16. 1909. Sur quelques
algues unicellulaires d’eau douce récoltées dans le domaine Malais. Ibid.,
Buitenzorg. 1910. Algues d’eau douce. Nova Guinea, 8: 253-270.
BERTHOLD, G. 1878. Untersuchungen iiber die Verzweigung einiger Siisswasser-
algen. Nova Acta Acad. Caes. Leop.-Carol. Germ. Nat. Curiosorum, 40:
167-230; Pls. 1-4.
BERTRAND, PauL. 1927. Les Botryococcacées actuelles et fossiles et les consé-
quences de leur activité biologique. Comp. Rend. Soc. Biol., 96: 695-697.
Bryerincx, M. W. 1890. Culturversuche mit Zoochlorellen, Lichenengonidien
und anderen niederen Algen. Bot. Zeit., 48: 725-739, 741-754, 757-768,
781-785; Pl. 7.
Buarapwaya, Y. 1933. False branching and sheath-structure in the Myxophy-
ceae, with special reference to the Scytonemataceae. Arch. f. Protist., 81:
243-283; Figs. 1-9. 1933a. Contributions to our knowledge of the Myxo-
phyceae of India. Ann. Bot., 47: 117-143. 1934. The taxonomy of Scytonema
[ 612 |
and Tolypothrix including some new records and new species from India
and Ceylon. Rev. Algol., 7: 149-178. 1935. The Myxophyceae of the United
Provinces, India. I. Proc. Indian Acad. Sci., 2( Sec. B.): 95-107.
Bicearp, E. 1933.+ Les Pediastrum d'Europe. Etude biologique et systématiquc.
Trav. Lab. Bot. Univ. Cathol. Angers, 5: 1-192. 1934-1936. Les Pediastrum
d‘Europe. Etude biologique et systématique. Rev. Algol., 7: 1-94, 327-418.
Birce, E. A. 1898. Plankton studies on Lake Mendota. II. Trans. Wis. Acad.
Sci., Arts and Letters, 11: 274-448.
Birce, E. A., and Jupay, C. 1911. The inland lakes of Wisconsin. The dissolved
gases of the water and their biological significance. Bull. Wis. Geol. and Nat.
Hist. Surv., Sci. Ser., 22: 1-259; Figs. 1-142. 1912. A limnological study of
the Finger Lakes of New York. Bull. U. S. Bur. Fisheries, 32(Doc. No. 791):
525-609. 1914. The inland lakes of Wisconsin. The hydrography and mor-
phometry of the lakes, by C. Juday. Bull. Wis. Geol. and Nat. Hist. Surv.,
Sci. Ser., 27: 1-137. 1922. The inland lakes of Wisconsin. The plankton. I.
Its quantity and chemical composition. Ibid., 64(Sci. Ser. No. 13): 1-222.
BisHop, AMELIA SAMANO. 1934. Contribucién al conocimiento de las algas
verdes de los lagos del valle de México. Ann. Inst. Biol., 5(No. 2): 149-177;
Pls. 1-3 (reprint ).
ByevyaEva, A. I. 1922. De sectione Aegagropila Kiitz. generis Cladophorae
Kiitz. et de nonnullis speciebus hujus sectionis in Rossia inventis. Not. Syst.
Inst. Crypt. Horti Bot. Petropol., 1( No. 6): 86-94.
Buiackpurn, K. B. 1936. Botryococcus and the algal coals. Part I. A reinves-
tigation of the alga Botryococcus Braunii Kiitzing. Trans. Roy. Soc. Edin-
burgh, 58( pt. 3): 841-854.
Biackman, F. F. 1900. The primitive algae and the flagellata. An account of
modern work bearing on the evolution of the algae. Ann. Bot., 14: 647-688;
Figs: 1, 2:
pees F. F., and Tanstey, A. G. 1902. A revision of the classification
of the green algae. New Phytol., 1: 17-24, 47-48, 67-72, 89-96, 114-120,
133-144, 163-168, 189-192, 213-220, 238-244.
BLANCHARD, Frank N. 1913. Two new species of Stigonema. Rhodora, 15:
192-200; Pl. 105.
Buu, J. R. 1943.* New species of Spirogyra. Amer. Jour. Bot., 30: 782-788;
Figs. 1-11.
poet nae: F. 1894. Ferskvandsalger fra Ostgrénland. Medd. om Gronland, 18:
3-41; Pls. 1, 2; Figs. 1,2. 1898. Nogle Ferskvandsalger fra Island. Bot. Tids.,
22: 131-188. 1899. Conspectus algarum novarum aquae dulcis, quas in
insulis Faeroensibus invenit. Vidensk. Medd. fra den Naturhist. Foren. i
Kjobenhavn, 1899: 317-336. 1901. Freshwater algae. Botany of the Faeroes,
Part I. pp. 198-259. Copenhagen.
BoercEsEN, F., and OstenreLp, C. H. 1903. Phytoplankton of lakes in the
Faerées. Botany of the Faerées, Part II. pp. 613-624; Figs. 147-150. Copen-
hagen.
poe Knut. 1897. Die Algen der ersten Regnell’schen Expedition. I. Pro-
tococcoideen. Bih. Kongl. Sv. Vet.-Akad. Handl., 23, Afd. 3, No. 7: 8-47;
Pls. 1,2. 1897a. Zur Morphologie und Biologie einzelliger Algen. Oefv.
Kongl. Sv. Vet.-Akad. Férhandl., 1897(No. 9): 507-529; Figs. 1-10. 1897b.
Studier 6fver niigra sligten af Alggruppen Confervales Borzi. Bih. Kongl. Sv.
Vet.-Akad. Handl., 23, Afd. 3, No. 3: 1-56; Pls. 1, 2. 1901. Etude sur la
flore algologique d’eau douce des Acores. Ibid., 27, Afd. 3, No. 4; 1-85; Pl. }.
Boxp, H. C. 1931. Life history and cell structure of Chlorococcum infusionum.
Bull. Torr. Bot. Club, 57: 577-604; Pls. 32-36, Figs. 1-5.
[ 613 ]
Botpt, R. 1885. Bidrag till kannedomen om Sibiriens Chlorophyllophycéer.
Oefv. Kongl. Sv. Vet.-Akad. Forhandl., 42(No. 2): 91-128. 1893. Nagra
sdtvattens-alger friin Gronland. Bot. Notiser, 1893: 156-158.
BoLocuonzEw, E. 1903. Ueber das Phytoplankton einiger Seen im Rostowshen
Kreise des Gouvernement Jaroslawe und zweier Seen des Gouvernement
Wadimir. Jahrb. d. Biol. Walgastation Saratow, 1903: 251-269.
Borce, O. 1891. Ett litet bidrag till Sibiriens Chlorophyllophycé-Flora. Bih.
Kong]. Sv. Vet.-Akad. Handl., 17, Afd. 3, No. 2: 1-16. 1892. Chlorophyl-
lophyceer fran Norska Finmarken. Ibid., 17, Afd. 3, No. 4: 3-15. 1894.
Siisswasser-Chlorophyceen gesammelt von Dr. A. Osw, Kihlman im nérd-
lichsten Russland, Gouvernement Archangel. Ibid., 19, Afd. 3, No. 5: 1-41.
1894a. Ueber die Rhizoidenbildung bei einigen fadenformigen Chlorophyceen.
61 pp., 2 pls. Upsala. 1895. Bidrag till kannedomen om Sveriges Chloro-
phycéer. II. Chlorophyllophyceen aus Falbygden in Vestergétland. Bih.
Kongl. Sv. Vet.-Akad. Handl., 21, Afd. 3, No. 6: 1-26. 1896. Australische
Siisswasserchlorophyceen. Ibid., 22, Afd. 3, No. 9: 1-32. 1899. Ueber tropische
und subtropische Siisswasser-Chlorophyceen. Ibid., 24, Afd. 3, No. 12: 1-33.
1900. Schwedisches Siisswasserplankton. Bot. Notiser, 1900: 1-26. 1901.
Siisswasseralgen aus Siid-Patogonien. Bih. Kongl. Sv. Vet.-Akad. Handl.,
27, Afd. 8, No. 10: 1-40; Pls. 1,2. 1906. Siisswasser-Chlorophyceen von
Feuerland und Isla Desolacion. Bot. Stud. t. F. R. Kjellman, 1906: 21-34.
1907. Beitriige zur Algenflora von Schweden. Arkiv f. Bot., 6(1906), No. 1:
1-88. 1906. [1907]. Algen aus Argentina und Bolivia. Ibid., 6( 1907), No. 4:
1-13; Figs. 1-5. 1909.* Nordamerikanische Siisswasseralgen. Ibid., 8, No.
13: 1-29. 1913. Zygnemales, Spezieller Teil. In A. Pascher, Die Siisswassser-
flora Deutschlands, Oesterreichs und der Schweiz, Heft 9: 12-51, Figs. 1-79;
Jena. 1918a. Beitriige zur Algenflora von Schweden. 2. Die Algenflora um
den Torne-Triisksee in Schwedisch-Lappland. Bot. Notiser, 1913: 1-82,
49-64, 97-110; Pls. 1-3; Figs. 1, 2. 1918 [1919]. Die von Dr. A. Lofgren
in Sao Paulo gesammelten Siisswasseralgen. Arkiv £. sBots WaNos 13):
1-108; Pls. 1-8. 1921. Die Algenflora des Takernsees. Sjon Takerns Fauna
och Flora. Kongl. Sv. Vet.-Akad., 1921(No. 4): 38-48; Pls. 1, 2; Figs.
1-3. 1922 [1923]. Beitrage zur Algenflora von Schweden. 3. Arkiv. f.
Bot., 18(No. 10): 1-34; Pls. 1, 2; Figs. 1, 2. 1925. Die von Dr. F. C. Hoehne
wahrend der Expedition Roosevelt-Rondon gesammelten Siisswasseralgen.
Ibid., 19(No. 17): 1-56; Pls. 1-6; Figs. 1-3. 1928. Siisswasseralgen. In B.
Schréeder, Zellpflanzen Ostafrikas, gesammelt auf der Akademischen Studien-
fahrt 1910. Teil VIII. Hedwigia, 68: 93-114; Pls. 1, 2; Fig. 1. 1933.
Schwedische-chinesische wissenschaftliche Expedition nach den nordwest-
lichen Provinzen. Arkiv f. Bot., 25A(No. 17): 1-18.
Borce, O., and Pascuer, A. 1913. (See Borge, 1913.)
Bornet, E. 1889. Les Nostocacées hétérocystées du Systema Algarum de C.
A. Agardh (1824) et leur synonymie actuelle (1889). Bull. Soc. Bot. France.
36: 144-157.
Bornet, E., and Franautt, Cu. 1885. Note sur le genre Aulosira. Bull. Soc.
Bot. France, 32: 119-122. 1885a. Tableau synoptique des Nostocacées
filamenteuses hétérocystées. Mém. Soc. Nat. Sci. Nat. et Math. Cherbourg,
25: 195-223; Ibid., 26: 137-152. 1886.+ Révision des Nostocacées hétéro-
cystées contenues dans ‘les principaux herbiers de France. Ann. Sci. Nat.
Bot., 3(Sér. 7): 323-381. 1886a.+ Part IL., Ibid., 4 (Sér. 7): 343-373; 1887.
Part III. Ibid., 5(Sér. 7): 51-129. 1888.+ Part IV. Ibid., 7(Sér. 7): 177-262.
1888a. Note sur deux nouveaux genres d’algues perforantes. Jour. Bot., 2:
[ 614 ]
161-165. 1889. Sur quelques plantes vivant dans le test calcaire des
mollusques. Bull. Soc. Bot. France, 36: cxtv-cLxxvi; Pls. 6-12.
BorneT, E., and Tuuret, G. 1876-1880. Notes algologiques, recueil d’obser-
vations sur les algues. Paris.
Bory bE St. ViNcENT, J. B. 1808. Mémoire sur le genre Lemanea de la famille
des Confervés. Ann. Mus. Hist. Nat. Paris, 12: 177-190. 1808a. Mémoire
sur le genre Draparnaldia de la famille des Confervés. Ibid., 12: 399-409.
1822-1831. In Dictionnaire d’histoire naturelle. Paris.
Borzi, A. 1878. Note alla morfologia e biologia delle alghe ficocromacee.
Nuovo Giorn. Bot. Ital., 10: 236-288. 1879. Ibid., 11: 347-388. 1882. Ibid.,
14: 272-315. 1883. Studi algologici. Fasc. 1: 1-112; Pls. 1-9. Messina.
1889. Botrydiopsis, nuova genre di alghe verdi. Boll. Soc. Ital. Microsc., 1:
66-70. 1892. Alghe d’acqua dolce della Papuasia raccolte su cranii umani
dissepolti. Nuova Notarisia, 3(1892): 35-53. 1894. Studi algologici. Fasc.
2: 121-378; Pls. 10-31. Palermo. 1895. Probabili accenni di conjugazione
presso alcune Nostochinee. Boll. Soc. Bot. Ital., 1895, No. 6: 208-210. 1914.
Studi sulle Mixoficee. I. Nuovo Giorn. Bot. Ital., 21(n. s.): 307-360. 1916.
Studi sulle Stigonemaceae. Ibid., 23(n.s.): 559-588. 1917. Ibid., 24(n.s.):
65-112.
BourrELty, P., and FELDMANN, J. 1946. Une algue méconne: Sphaeroplea
Soleirolii (Duby) Montagne. Bull. Mus. Paris, 18(No. 5): 412-415; Figs.
1-11.
BoyE-PETERSEN, JOHN. 1923. The Botany of Iceland. Vol. 2, Part 2, No. 2:
249-324.
Bracuer, R. 1919. Observations on Euglena deses. Ann. Bot., 33: 93-108.
Branp, F. 1899. Mesogerron, eine neue Chlorophyceen-Gattung. Hedwigia,
38: [181-184]. 1899a. Cladophora-Studien. Bot. Centralbl., 79: 145-152,
177-186, 209-221, 287-311; Pls. 1-3. 1901. Ueber einige Verhiltnisse des
Baues und Wachsthums von Cladophora. Beih. Bot. Centralbl., 10: 481-521;
Figs. 1-10. 1902. Zur niheren Kenntnis der Algengattung Trentepohlia
Mart. Ibid., 12: 200-205; Pl. 6. 1902a. Die Cladophora-Aegagropilen des
Siisswassers. Hedwigia, 41: 34-71; 1 pl. 1905. Ueber die Anheftung der
Cladophoraceae, und iiber verschiedene polynesische Formen dieser Familie.
Beih. Bot. Centralbl., 18: 165-193. 1907. Ueber charakteristische Algen-
Tinktionen, sowie iiber eine Gongrosira und eine Coleochaete aus dem
Wiirmsee. Ber. d. Deutsch. Bot. Ges., 25; 497-506. 1908. Zur Morphologie
und Biologie des Grenzgebietes zwischen den Algengattung Rhizoclonium
und Cladophora. Hedwigia, 48: 45-73. 1909. Ueber die Siisswasserformen
von Chantransia (DC.) Schmitz, einschliesslich Pseudochantransia Brand.
Ibid., 49: 107-118. 1909a. Ueber die morphologischen Verhaltnisse der
Cladophora-Basis. Ber. d. Deutsch. Bot. Ges., 27: 292-300. 1918. Ueber
Cladophora humida n. sp., Rhizoclonium lapponicum n. sp., und deren
bostrychoide Verzweigung. Hedwigia, 53: 179-183.
Branp, F., and SrockMayeER, S. 1925. Analyse der aerophilen Griinalgenanfliige,
insbesondere der proto-pleurococcoiden Formen. Arch. f. Protist., 52: 265-
855; Pl. 11.
Branpt, K. 1882. Ueber die morphologische und physiologische Bedeutung
des Chlorophylls bei Thieren. Arch. Anat. Physiol. Abth., Heft 1: 125-150.
BRAUN, ALEXANDER. 1834. Esquisse monographique du genre Chara. Ann. Sci.
Nat. Bot., 1(Sér. 2): 849-857. 1845. Additional notices of the North
American Charae. In G. Englemann and A. Gray, Plantae Lindheimerianae.
Boston Jour. Nat. Hist., 5: 264. 1847. Uebersicht der Schweizerischen
Characeen. Neue Denkschr. d. Schweiz. Ges. d. Natur., 10: 1-23 (reprint,
[ 615 ]
1849). 1849. In F. T. Kuetzing, Species algarum. 1851. Betrachtungen tiber
die Erscheinung der Verjiingung in der Natur. Leipzig. 1855.+ Algarum
unicellularum genera nova vel minus cognita. Pls. 1-6. Leipzig. 1856. Ueber
Chytridium, eine Gattung einzelliger Schmarotzergewachse auf Algen und
Infusorien, Abh. K. K. Akad. d. Wiss. z. Berlin, 1855: 21-83. 1865. In L.
Rabenhorst. Florae Europaea algarum aquae dulcis et submarinae. 2. Leipzig.
Braun, ALEXANDER, and Grunow, A. 1865. In L. Rabenhorst. F lorae Europaea
algarum aquae dulcis et submarinae. 2. Leipzig.
Brépisson, A. pe. 1844, Description de nouveaux genres d’algues fluviatiles.
Ann. Sci. Nat. Bot., 1 (Ser. 3): 25-81. Pls. 1, 2.
Brébisson, A. de, and Godey, P. 1835. Algues des environs de Falaise
décrites et dessinées. pp. 1-66. Falaise. 1836. Ibid. Mém. Soc. Acad. sci.
arts et bell. lettr. de Falaise Bot., 1835: 1-62, 266-269.
BreHM, V. 1910. Ueber tropisches Siisswasserplankton. Die Kleinwelt, 1:
171-175.
BRETSCHNEIDER, L. H. 1926. Ueber den feineren Bau von Phacus costata
Conrad. Arch. f. Protist., 53: 131-134.
BristoL, B. Muriev. 1920. A. review of the genus Chlorochytrium, Cohn. Jour.
Linn. Soc. Bot. London, 45: 1-28; Pls. 1-3. 1920a. On the alga-flora of
some desiccated English soils. Ann. Bot., 34: 35-80; Pl. 2.
Britton, M. E. 1943. New species of Chlorophyceae. Amer. Jour. Bot., 30:
799-800; Figs. 1-3.
Britron, M. E., and Smirn, B. H. 1942. A new species ef Spirogyra. Ohio
Jour. Sci., 42; 70.
Brown, C. J. D. 1943. How many lakes in Michigan? Mich. Conserv., 12(5)i:
6—7.
Brown, HeLen Jean. 1929.+ The algal family Vaucheriaceae. Trans. Amer.
Microsc. Soc., 48: 86-117; Pls. 15-20. 1937." A new species of Vaucheria
from northern Michigan. Ibid., 56: 283-284; Fig. 1.
Brown, W. H. 1909. The plant life of Ellis, Great, Little, and Long Lakes in
North Carolina. Contrib. U. S. Nat. Herb., 13(1909-1913): 323-341.
BrRUNEL, JULEs. 1932. Etudes sur la flora algologique du Québec. I. Contrib.
Lab. Bot. Univ. Montreal, No. 22: 3-19; Figs. 1-3. 1947. Vaucheria Schlei-
cheri in North America. Contrib. Gray Herb., 165: 62-69; Figs. 1, 2.
BRUNNTHALER, J. 1901. Die koloniebildenden Dinobryon-Arten. Ver. Cae KG
Zool.- Bot. Ges. in Wien, Math.-Nat. Kl1., 51: 293-306. 1903. Phytoplankton
aus Kleinasien. Sitz. K. K. Akad. Wiss. Wien, Math.-Nat. Kl, 112(1902),
Abt. 1: 289-293. 1907. Die Algen und Schizophyceen der Altwisser der
Donau bei Wien. Ver. K. K. Zool.-Bot. Ges. Wien, Math.-Nat. Kl., 57:
170-223. 1912. Systematische Uebersicht iiber die Chlorophyceen-Gattung
Scenedesmus Meyen. Hedwigia, 53: 164-172. 1913. Die Algengattung
Radiofilum Schmidle und ihre systematische Stellung. Oesterr. Bot. Zeit.,
63(No. 1): 1-8; Figs. 1-3. 1914. Beitrag zur Siisswasser-Algenflora von
Aegypten. Hedwigia, 54: 919-225. 1915.+ Protococcales. In A. Pascher, Die
Siisswasserflora Deutschlands, Oesterreichs und der Schweiz. Heft 5. Chloro-
phyceae 2: 52-205; Figs. 1-330. Jena.
Bucuanan, R. E. 1907. Notes on the algae of Iowa. Proc. Iowa Acad. Sci.,
14: 47-84.
Buppve, H. 1940. Beitrige zur Kenntnis der bayerischen Batrachospermum-
Arten aus der Umgebung von Tolz. Ber. Bayr. Bot. Ges., 24: 87-94.
Buri, HEeLen F. 1938. The taxonomy of a community of blue-green algae in
a Minnesota pond. Bull. Torr. Bot. Club, 65: 377-396; Figs. 1-12.
Buerscuui, O. 1878. Beitrige zur Kenntnis der Flagellaten und einiger ver-
wandter Organismen. Zeit. f. Wiss. Zool., 30: 205-281. 1883-1887. Masti-
[ 616 ]
gophora, Protozoa. In H. G. Bronn, Klassen und Ordnungen des Tier-Reiches,
1, Abt. 2; Pls. 39-55. Leipzig and Heidelberg.
BURKHOLDER, Paut R. 1930. Microplankton studies of Lake Erie. Bull. Buffalo
Soc. Nat. Sci., 14: 73-91. 1931. Studies in the phytoplankton of the Cayuga
Lake basin, New York. Ibid., 15: 21-179.
Burr, Geo. O. 1941. Photosynthesis of algae and other aquatic plants. In
A Symposium on Hydrobiology, Madison.
Carxins, G. N. 1892. On Uroglena, a genus of colony-building infusoria ob-
served in certain water supplies of Massachusetts. 23rd Ann. Rep. State Bd.
of Health, Mass., 1892: 647-657; Pls. 1-4. 1926. Biology of the Protozoa.
New York.
CampsELL, D. H. 1886.* Plants of the Detroit River. Bull. Torr. Bot. Club,
13: 93-94.
Carter, Neuuie. 1919. On the cytology of two species of Characiopsis. New
Phytol., 18: 177-186; Figs. 1-3.
Carter, H. J. 1856. Notes on the freshwater infusoria of the Island of Bom-
bay. No. 1. Organization. Ann. and Mag. Nat. Hist., 18(Ser. 2): 115-132,
221-249. 1859. On fecundation in the two Volvoces, etc. on Eudorina
Spongilla, Astasia, Euglena and Cryptoglena. Ibid., 3( Ser. 3): 1-20.
- CavanaucH, W. J., and TiLpEN, JOSEPHINE. 1930. Algal food, feeding and
case-building habits of the larva of the midge fly, Tanytarsus dissimilis.
Ecology, 11: 281-287.
Cavers, F. 1913. Recent work on flagellata and primitive algae. New Phytol,
12: 28-36, 78-83, 107-123, 177-187, 225-232; Figs. 1-10.
CEDERCREUTZ, Cart. 1924. Finnlaindische Zygnemalen. Acta Soc. Fauna et
Flora Fenn., 55(No. 2): 1-7. 1931. Zwei neue Heterokontenarten. Arch. f.
Protist., 75: 517-522. 1934. Die Algenflora und Algen-vegetation auf Aland.
Acta Bot. Fenn., 15: 1-120; Pls. 1-5; 2 maps.
CEDERGREN, G. R. 1926. Beitrage zur Kenntnis der Siisswasseralgen in Schwe-
den. II. Die Algen aus Bergslagen und Wiasterdalarne. Bot. Notiser, 1926:
289-313. 1932. Die Algenflora der Provinz Harjedalen. Arkiv f. Bot.,
25A(No. 4): 1-107.
Cuaperaup, M. 1938. Nouvelle recherches sur l’anatomie comparée des
Eugleniens: les Peranémines. Rev. Algol., 11: 189-220.
Cuamsers, C. O. 1912. The relation of algae to dissolved oxygen and carbon
dioxide, with special reference to carbonates. 23rd Ann. Rep. Missouri Bot.
Gard., 1912: 171-207.
CHANDLER, D. C. 1937. Fate of typical lake plankton in streams. Ecol. Monogr.,
7: 445-479, 1939.* Plankton entering the Huron River from Portage and
Base Line Lakes, Michigan. Trans. Amer. Microsc. Soc., 58: 24-41. 1944.
Limnological studies of western Lake Erie. IV. Ibid., 63: 203-236.
Cuapman, F. B. 1934. The algae of the Urbana (Ohio) raised bog. Ohio
Jour. Sci., 834: 327-332.
Cuapman, V. J. 1941. An introduction to the study of algae. New York. 1943.
The aims of future research in the algae. Farlowia, 1: 5-8.
CumirLewsx1, V. 1890. Matériaux pour servir 4 la flora des algues du governe-
ment de Kharkow. Trav. Soc. Nat. Univ. Imp. Kharkow, 23: 79-105.
Cuopat, R. 1894. Golenkinia, genre nouveau des Protococcoidées. Jour. Bot.,
8: 305-308. 1894a. Matériaux pour servir a histoire des Protococcoideées.
Bull. Herb. Boiss., 2: 585-616; Pls. 22-29. 1894b. Algues des environs de
Genéve. Comp. Rend. Soc. Phys. et Hist. Nat. Genéve, In Arch. Sci. Phys.
et Nat., 32: 623-625. 1895. Sur le genre Lagerheimia. Nuova Notarisia, 6:
86-90. 1895a. Matériaux pour servir 4 histoire des Protococcoidées. II. Bull.
[ 617 ]
Herb. Boiss., 3: 109-114. 1895b. Ueber die Entwickelung der Eremosphaera
viridis de By. Bot. Zeit., 53: 137-142; Pl. 5. 1896. Sur la structure et la
biologie de deux algues pélagiques. Jour. Bot., 10: 333-349, 405-408; PI. 3.
1897. Algues pélagiques nouvelles. Bull. Herb. Boiss., 5: 119-120. 1897a.
Etudes de biologie lacustre. A. Recherches sur les algues pélagiques de
quelques lacs suisses et frangais. Ibid., 5: 289-314. 1898. Etudes de biologie
lacustre. B. Nouvelles remarques sur la flore pélagique superficielle des lacs
suisses et francais. Ibid., 6: 49-77, 155-188. 1898a. Etudes de biologie
lacustre. C. Recherches sur les algues littorales. Ibid., 6: 431-475; Pls. 14,
15. 1900. Sur trois genres nouxeaux de Protococcoidées et sur la florule
planktonique d’un étang du Danemark. Mém. Herb. Boiss., 1(No. 17): 1-10;
Figs. 1-20. 1902. Algues vertes de la suisse. Pleurococcoides-Chroolépoides.
Matér. pour la Flore Crypt. Suisse, 1(No. 3): 1-373; Figs. 1-264. 1918.
Monographie d’algues en culture pure. Ibid., 4(Fasc. 2): 1-226; Pls. 1-9.
1919. Sur un Glaucocystis et sa position systématique. Bull. Soc. Bot. Genéve,
11: 42-49; Figs. 1,2. 1921. Matériaux pour histoire des algues de la
Suisse. I-IX. Ibid., 13: 66-114. 1926.+ Scenedesmus. Etude de genetique, de
systématique expérimentale et d’hydrobiologie. Rev. d’Hydrol., 3: 71-258;
Figs. 1-162.
Cuopat, R., and Cuopat, F. 1925. Esquisse planctologique de quelques lacs
francais. Festschr. Carl Schroter, 3: 436-459; Figs. 1-14.
Cuopat, R., and Grinrzesco, J. 1900. Cultures pure d’algues Protococcacées.
Comp. Rend. Soc. Phys. et Hist. Nat. Genéve, in Arch. Sci. Phys. et Nat.,
10: 386-387.
Crenxowsk1, L. 1855. Algologische Studien. 2. Protococcus botryoides Kuetz.
Bot. Zeit., 13: 780-782; Pl. 11. 1865. Ueber einige chlorophyllhaltige
Gloeocapsen. Ibid., 23(No. 8): 21-27; Pl. 1. 1870. Ueber Palmellaceen und
einige Flagellaten. Archiv f. Mikro. Anat., 6: 421-438; Pls. 23,24. 1876:
Zur Morphologie der Ulothricheen. Bull. Acad. Imp. Sci. St. Péters. 21:
529-557; Pls. 1, 2. 1881. [Algologische excursion an das Weiss Meer]. Arb.
d. Kais, St. Petersb. Ges. d. Naturf., 12: 130-171.
Cuarke, G. L., and Getuis, S. S. 1935. The nutrition of copepods in relation
to the food cycle of the sea. Biol. Bull., 68: 231-246.
CLAPAREDE, Ep., and LacuMann, J. 1857-1861. Etudes sur les infusiores et
les rhizopodes. Mém. Instit. Nat. Genevois, 5( 1858): 1-260; Ibid., 6(1860):
261—482.; Ibid., 7( 1861): 1-291.
Creve, P. T. 1868. Férsok till en monografi éfver de Svenska arterna af
Algfamiljen Zygnemaceae. Nova Acta Reg. Soc. Sci. Upsala, 6(Ser. 3),
No. 11: 1-88.
Cocuran, L. C. 1932.* A thermophilic Calothrix in Michigan. Pap. Mich.
Acad. Sci., Arts, and Letters, 15: 63-64.
Coun, F. [1852]. Ueber eine neue Gattung aus der Familie des Volvocinen.
Zeit. f. Wiss. Zool., 4: 77-116. 1856. Mémoire sur le développement et Je
mode de reproduction du Sphaeroplea annulina. Ann. Sci. Nat. Bot., 5(Sér.
4): 187-208; Pls. 12, 13. 1875. Ueber parasitische Algen. Beitr. Biol. Pflan-
zen, 1(No. 2): 87-108. 1875a. Die Entwickelungsgeschichte der Gattung
Volvox. Ibid., 1(No. 8): 93-115; Pl. 2.
Coun, F., and Wicuura, M. 1858. Ueber Stephanosphaera pluvialis. Nova
Acta Caes. Leop.-Carol. Germ. Nat. Curiosorum, 26: 1-BPe TAS, 15 BA
Coxer, W. C. 1919. A parasitic blue-green alga. Jour. Elisha Mitchell Sci.
Soc., 35:9.
Co.uins, F. S. 1896. New Cyanophyceae. Erythea, 4: 119-121. 1897. Some
perforating and other algae on fresh water shells. Ihid.. 5: 95-97. 1899.
[ 618 ]
Notes on algae. I. Rhodora, 1: 9-11. 1901. Ibid. Ill. Ibid., 3: 132-137. 1904.
Algae of the flume. Ibid., 6: 229-231. 1905. Chlorochytrium Lemnae in
North America. Ibid., 7: 97-99. 1907. Some new green algae. Ibid., 9:
197-202. 1909.+* The green algae of North America. Tufts College Studies,
Sci. Ser., 2: 79-480, Pls. 1-18 (reprinted and repaged by G. E. Stechert,
New York, 1928). 1912.+* The green algae of North America. Supplementary
Paper. Ibid., 3(No. 2): 69-109; Pls. 1, 2 (reprinted by G. E. Stechert, New
York, 1928). 1918.+ Notes from the Woods Hole Laboratory. Rhodora, 20:
141-143. 1918a.t The green algae of North America, 2nd Suppl. Tufts
College Studies, Sci. Ser., 4: 1-106; Pls. 1-3 (reprinted by G. E. Stechert,
New York, 1928).
Comenre, J. 1911. Additions a la flore des algues d’eau douce du pays toulousain
et des Pyrénées centrales. Bull. Soc. d’Hist. Nat. Toulouse, 44: 9-60.
Conn, H. W., and Wesster, Lucia W. 1908. A preliminary report on the
algae of the fresh waters of Connecticut. Conn. State Geol. and Nat. Hist.
Surv., Bull. 10: 1-78; Pls. 1-44.
Conran, W. 1913. Errerella bornhemiensis nov. gen., une Protococcacée nou-
velle. Bull. Soc. Roy. Bot. Belgique, 52: 237-242; Figs. 1-3. 1914. Contri-
butions a l’étude des flagellates. I. Arch. f. Protist., 34: 79-94. 1914a. Algues,
Schizophycées et flagellates récoltés par M. W. Reckert aux environs de
Libau (Courlande, Russie). Ann. Biol. Lacustre, 7: 126-152. 1916. Revision
des espéces indigénes et frangaises du genre Trachelomonas Ehrenbg. Ibid.,
8: 193-212. 1920. Contributions 4 T’étude des Chrysomonadines. Acad.
Roy. Belgique, Cl. des Sci., 1920: 167-189; Figs. 1-11. 1922. Contributions
a étude des Chrysomonadines. Rec. Inst. Léo Errera, 10: 333-353;
Figs. 1-11. 1926. Recherches sur les flagellates de nos eaux saumatres.
2. Chrysomonadines. Arch. f. Protist., 56: 167-231. 1927. Essai d'une
monographie des genre Mallomonas Perty (1852) et Pseudomallomonas
Chodat (1920). Ibid., 59: 423-505; Pls. 8-11. 1932. Flagellates nou-
veaux ou peu connus. III (Formes nouvelles du genre Trachelomonas
Ehrbg.). Ibid., 78: 463-472. 1933.+ Révision du genre Mallomonas Perty
(1851) incl. Pseudo-Mallomonas Chodat (1920). Mém. Mus. Roy. d’Hist.
Nat. de Belgique, 56: 1-82; Figs. 1-70. 1934.+ Matériaux pour une mono-
graphie du genre Lepocinclis Perty. Arch. f. Protist., 82: 203-249. 1934a.
Euglenacées nouvelles ou peu connues. Ann. Protist., 4: 171-180. 1935.+
Etude systématique du genre Lepocinclis Perty. Mém. Mus. Roy. d'Hist.
Nat. Belgique, 1(Sér. 2): 1-84. 1940. Notes protistologiques. 15. Sur une
Euglena du psammon de Iescaut. Bull. Mus. Roy. Hist. Nat. Belgique,
16(No. 29): 1-12. 1940a. Notes protistologiques. 16. Sur Peridinium
Woloszynskae n. sp. Ibid., 16(No. 32): 1-8.
Conran, W., and Kurreratu, H. 1912. Addition a la flore algologique de la
Belgique. Bull. Soc. Roy. Bot. Belgique, 49(Pt. 1): 293-335.
Cooxe, M. E. 1882-1884.+ British freshwater algae, exclusive of Desmidieae
and Diatomaceae. 329 pp.; Pls. 1-130. London.
Corpa, A. J. C. 1835-1839. Observations sur les animalicules microscopiques,
won trouve auprés des eau thermales de Carlsbad. Almanach de Carlsbad,
1835-1839.
Correns, C. 1893. Ueber Apiocystis Brauniana Naeg. In A. Zimmermann,
Beitr. z. Pflanzenzelle. 1( Heft 3): 241-259; Figs. 1, 2.
Couey, Faye M. 1935.* Fish food studies of a number of northwestern Wis-
consin lakes. Trans. Wis. Acad. Sci., Arts, and Letters, 29: 131-172.
Coyie, ExizaBetu. 1930. The algal food of Pimephales promelas. (Fathead
minnow). Ohio Jour. Sci., 30: 23-25.
[ 619 ]
Cramer, C. E. 1859. Oedogonium Pringsheimii Cramer. Hedwigia, 2: 17-19.
CroAsDALE, Hannay T. 1935. The fresh water algae of Woods Hole, Mass-
achusetts. 134 pp.; Pls. I-VII; maps. Philadelphia.
Crow, W. B. 1922. A critical study of certain unicellular Cyanophyceae from
the point of view of their evolution. New Phytol., 21: 81-102; Fig. 1. 1923.
Fresh-water plankton algae from Ceylon. Jour. Bot., 61: 110-114, 138-145,
164-171. 1924. Variation and species in Cyanophyceae. Jour. Genetics, 14:
397-424; Figs. 1-8. 1924a. Some features of the envelope in Coelastrum.
Ann. Bot., 38: 398-401; Figs. A, B. 1925. The reproductive differentiation
of colonies in Chlamydomonadales. New Phytol., 24: 120-123. 1927. The
generic characters of Arthrospira and Spirulina. Trans. Amer. Microsc. Soc.,
46: 139-148. 1927a. Abnormal forms of Gonium. Ann. and Mag. Nat. Hist.,
19(Ser. 9): 593-601; Figs. A-G. 1928. The morphology of the filaments of
Cyanophyceae. Ann. Protist., 1: 19-36.
Curtis, J. T., and Jupay, C. 1937.* Photosynthesis of algae in Wisconsin lakes.
III. Observations in 1935. Inter. Rev. Ges. Hydrobiol., 35: 122-133; Figs.
, 2: Tab. 1-2:
Czurpa, V. 1932.+ Zygnemales. In A. Pascher, Die Siisswasserflora Mitteleu-
ropas, Oesterreichs und der Schweiz. Heft 9: 1-232; Figs. 1-226. Jena. 1939.
Zygnemales der Deutschen Limnologischen Sunda-expedition. Archiv. f.
Hydrobiol. Suppl., 16: 398-427.
Da Cunna, A. M. 1913. Contribuigao para o conhecimento da fauna de pro-
tozoarios do Brasil. Mem. Inst. Oswaldo Cruz, 5: 101-122. 1914. Beitrag
zur Kenntnis der Protozoen-fauna Brasiliens. II. Ibid., 6: 169-175.
Dapay, F. 1907. Plankton-Tiere aus dem Victoria Nyanza. Sammelausbeute
von A. Bogert, 1904-1905. Zool. Jahrb. Abt. System, 25( Heft 2): 245-262.
Dairy, Fay K. 1944. The Characeae of Nebraska. Butler Univ. Bot. Studies,
6: 149-171; Figs. 1A-5C. 1946. Species of Tolypella in Nebraska. Ibid.,
8: 1138-116; Figs. 1A-1C.
Dairy, WM. A. 1938. A quantitative study of the phytoplankton of Lake
Michigan collected in the vicinity of Evanston, II]. Butler Univ. Bot. Studies,
4: 65-83. 1942. The Chroococcaceae of Ohio, Kentucky, and Indiana. Amer.
Midl. Nat., 27: 636-661; Pls. 1-6.
Damann, K. E. 1938. Quantitative study of the phytoplankton of Lake Mich-
igan at Evanston, Illinois. Butler Univ. Bot. Studies, 5: 27-44.
DancEarp, P. A. 1888. Recherches sur les algues inférieures. Ann. Sci. Nat.
Bot., 7(Sér. 7): 105-175; Pls. 11, 12. 1889. Recherches sur les Cryptomona-
dinae et les Euglenae. Le Botaniste, 1: 1-38. 1889a. Mémoire sur les algues.
Ibid., 1: 127-174;Pls. 6,7. 1899. Mémoire sur les Chlamydomonadinées ou
histoire d’une cellule. Jbid., 6: 65-290; Figs. 1-19. 1900. Observations sur
le développement du Pandorina morum. Ibid., 7: 192-211; Pl. 5. 1901.
Etude sur la structure de la cellule et ses fonctions, le Polytoma uvella. Ibid.,
8: 5-58; Figs. 1-4. 1902. Recherches sur les Eugléniens. Ibid., 8(1901):
97-360. 1911. Un nouveau genre d’algues. Bull. Soc. Bot. France, 58:
309-311. 1912. Recii2rches sur quelques algues nouvelles ou peu connues.
Le Botaniste, 12: I-XIX; Pls. 1,2. 1938. Mémoire sur la famille des Péri-
diniens. Ibid., 29: 1-180. 1939. Le genre Vaucheria, spécialement dans la
région du sud-ouest de la France. Ibid., 29: 183-264. 1939a. Second mémoire
sur la famille des Péridiniens. Ibid., 29: 267-808. 1939b. Sur les algues
Vaucheria observées dans la région du sud-ouest et sur une nouvelle espéce
de ce genre. Comp. Rend. Acad. Sci. Paris, 208: 297-299.
Davis, B. M. 1894. Euglenopsis, a new alga-like organism. Ann. Bot., 8: 877-
[ 620 ]
390; Pl. 19. 1896. The fertilization of Batrachospermum. Ibid., 10: 49-76;
Pls. 6,7. 1904. Oogenesis in Vaucheria. Bot. Gaz., 38: 81-98; Pls. 6, 7.
Davis, C. A. 1900.* A contribution to the natural history of marl. Jour. Geol.,
8: 485-497. 1908. The flora. A biological survey of Walnut Lake, Michigan.
Ann. Rep. Mich. Geol. Surv., 1907: 217-231.
Dr, P. K. 1939. The réle of blue-green algae in nitrogen fixation in rice fields.
Proc. Roy. Soc. London (B), 127: 121-139.
DeBary, A. A. 1854. Ueber die Algengattungen Oedogonium und Bulbochaete.
Abh. Senck. Nat. Ges. Frankfurt A. M., 1: 29-105. 1858. Untersuchungen
iiber die Familie der Conjugaten (Zygnemeen u. Desmidieen). 91 pp.; Pls.
1-8. Leipzig.
DeCanpotte, A. P. 1802. Rapport sur les Conferves. Jour. de Phys. et Chimie
et d’Hist. Nat., 54: 421-441. 1805. Flore Francaise, II. 3rd ed. Paris.
Drr.anpreE, G. 1924. Additions 4 la flore algologique des environs de Paris.
II.—Flagellées. Bull. Soc. Bot. France, 71: 1115-1180. 1924a. A propos de
Euglena acus Ehrenb. Rev. Algol., 1: 235-243. 1926.+ Monographie du
genre Trachelomonas. Pls. 1-15. Nemours. 1926a. Contribution a la flore
algologique de la Basse-Normandie. Bull. Soc. Bot. France, 73: 701-717.
1926b. Algues d’eau douce du Vénézuela (Flagellées et Chlorophycées )
récoltées par la Mission M. Grisol. Rev. Algol., 3: 211-241. 1927. Remarques
sur la systématique du genre Trachelomonas Ehr. I. Bull. Soc. Bot. France,
74: 285-288. Ibid. Il. Quarte Trachelomonas nouveaux. Ibid.: 657-665.
1930. Strobomonas, nouveau genre d’Euglenacées (Trachelomonas Ehrb.
pro parte). Archiv f. Protist., 69: 551-614. 1932. Contributions 4 la con-
naissance des Flagellés libres. I. Ann. Protist., 3: 219-239.
De Lacerpa, F. S. 1946. Oedogoniaceae de Portugal. Portugal Acta Biol.,
11(Ser. B): 1-142; Figs. I-LXVIII.
Denis, M., and Fremy, P. 1923. Une nouvelle Cyanophycée heterocystée
Anabaena Viguieri. Bull. Soc. Linn. Normandie, 6(Sér. 7): 122-125.
Denniston, R. H. 1921.* A survey of the larger aquatic plants of Lake Men-
dota. Trans. Wis. Acad. Sci., Arts, and Letters, 20: 495-500.
Densés, A., and Soxser, A. J. J. 1850. Sur les organes reproducteurs des algues.
Ann. Sci. Nat. Bot., 4(Sér. 3): 261-282. 1856. Mémoire sur quelques points
de la physiologie des algues. Paris.
Desmazizres, J. B. H. J. 1823. Catalogue des plantes omises dans la botano-
graphie belgique. Lille. 1825-1860. Plantes cryptogames de France. Ed. ,
Fase. 144 (1825-1836). Ed. II, Fasc. 1-37 (1836-1851). Ed. Novae.
Fasc. 1-16 (1853-1860). Lille.
Desvaux, A. N. 1818. Observations sur les plantes environs de Angers. Paris.
DeTon1, G. B. 1889.+ Sylloge algarum omnium hucusque cognitarum. I. Padua.
1907. Ibid. Myxophyceae. V. (A. Forti). Padua.
De Tont, G. B., and Fort, A. 1899-1900. Contributo alla conoscenza del planc-
ton del Lago Vetter. Atti Reale Istit. Veneto Sci., Lett. ed Arti, 59: 537-561,
779-829. (Note: pages 537-561 erroneously occur twice in Vol. 59. The
citation refers to the first series of these pages. )
DeETont, G. B., and Saccarpo, Fr. 1890. Revisione de alcuni generi di Cloro-
ficee epifite. Nuova Notarisia, 1: 3-20.
De WitpeMann, E. 1888. Observations algologiques. Bull. Soc. Roy. Bot.
Belgique, 27: 71-80 bis. 1892. Quelques mots sur le genre Scenedesmus
Turpin. Ibid., 31(Pt. 2): 218-224. 1893. Le genre Scenedesmus Meyen.
Notarisia, 1893: 85-106. 1893a. Contribution a l’étude des algues de Bel-
gique. Ibid., 32(Pt. 2): 88-101. 1895. Le genre Palmodictyon Nag. Bull.
[ 621 ]
Herb. Boiss., 3: 328-333. 1897. Encore le Pleurococcus nimbatus de Wild.
Ibid., 5: 582.
Diesinc, K. M. 1866. Revision der Prothelminthen. Abtheilung Mastigophoren.
Sitz. K. K. Akad. Wiss. Wein, Math.-Nat. K]., 52(1865), Abt. 1: 287-401.
Dit, O. 1895. Die Gattung Chlamydomonas und ihre nachsten Verwandten.
Pringsh. Jahrb. f. Wiss. Bot., 28: 323-358; Pl. 5.
Dittwyn, F. 1802. British conjugates. London .
Driwatp, Kar. 1989. Ein Beitrag zur Variabilitét und Systematik der Gattung
Peridinium. Arch. f. Protist., 93: 121-148.
Dortein, F. 1916. Lehrbuch der Protozoenkunde. IV. Auflage. Jena. 1921.
Mitteilungen iiber Chrysomonadinen aus dem Schwarzwald. Zool. Anz., 53:
153-173; Figs. 1-4. 1922. Untersuchungen iiber Chrysomonadinen. Arch. f.
Protist., 44: 149-213. 1923. Untersuchungen tiber Chrysomonadinen. III.
Arten von Chromulina und Ochromonas aus dem Badischen Schwarzwald
und ihre Cystenbildung. Ibid., 46: 267-327; Pls. 15-21. Figs. A-E.
Dottey, Joun S. 1933.* Preliminary notes on the biology of the St. Joseph
River. Amer. Midl. Nat., 14: 193-227.
Domocatta, B. P. 1926.* Treatment of algae and weeds in lakes at Madison,
Wisconsin. Eng. News Record, Dec. 9, 1926: 950-954. 1935.* Eleven years
of chemical treatment of the Madison lakes: its effect on fish and fish foods.
Trans. Amer. Fish. Soc., 65: 115-120.
Domoca..a, B. P., and Frep, E. B. 1926. Ammonia and nitrate studies of
lakes near Madison, Wisconsin. Jour. Amer. Soc. Agronomy, 18: 897-911.
Dorocostaisky, V. 1905. Matériaux pour servir a l’algologie du lac Baikal et de
son bassin. Bull. Soc. Imp. Nat. Moscou, 1904(No. 2/3): 228-265.
DreEZEPOLSKi, R. 1923. De Eugleninis se ipsis sustinentibus ex collectione facta
a Dr. J. Grochmalicki in Podlachi et Lithuania. Obd. z Rozpraw i wradomosci
z Muzeum im Dzied, 7/8(1922): 1-19. 1925. Przyeznek do znajomosci
polskich Euglenin. (Supplément a la connaissance des Eugléniens de la
Pologne.) “Kosmos,” Jour. Soc. ,Polonaise Nar. “Kopernik,” 50(Fasc. 1.A):
173-270; Pls. 1-6.
Drover, F. 1937. The Brazilian Myxophyceae. I. Amer. Jour. Bot., 24: 598-
608; Figs. 1-5. 1938. Ibid. Il. Ibid., 25: 657-666. 1938a. The Oscillatoriaceae
of southern Massachusetts. Rhodora, 40: 221-241, 255-278. 1939. Francis
Wolle’s filamentous Myxophyceae. Field Mus. Bot. Ser., 20: 17-64; Fig. 1.
1939a. The Myxophyceae of Maryland. Ibid., 20: 3-14. 1942. Studies in
Myxophyceae. I. Ibid., 20: 125-141. 1943. New species of Oscillatoriaceae.
Amer. Midl. Nat., 29: 51-54.
Drovet, F., and Coun, A. 1935. The morphology of Gonyostomum semen
from Woods Hole, Massachusetts. Biol. Bull., 68: 422-439. 1937. Further
observations on Gonyostomum semen. Bot. Gaz., 98: 617-618.
Drovet, F., and Damty, WM. A. 1939. The planktonic freshwater species of
Microcystis. Field Mus. Bot. Ser., 20: 67-83.
Duyarpin, M. F. 1841. Histoire naturelle des Zoophytes. Infusiores, compre-
nant la physiologie et la classification de ces animaux et la maniére de les
estudier 4 l'aide du microscope. In Suites a Buffon. Paris.
Dutton, H. J. 1941. The chromatographic adsorption of plant pigments as a
limnological method. In A Symposium on Hydrobiology. Madison.
Dutton, H. J., and Mannine, W. M. 1941. Evidence for carotenoid-sensitized
photosynthesis in the diatom Nitzschia Closterium. Amer. Jour. Bot., 28;
516-526.
Eppy, SAMUEL. 1927.* The plankton of Lake Michigan. Ill. Nat. Hist. Surv., 17:
[ 622 }
203-232. 1930.+ The fresh-water armored or thecate Dinoflagellates. Trans.
Amer. Microsc. Soc., 49: 277-321; Pls. 28-35.
Epmonpson, C. H. 1906. The Protozoa of Iowa. Proc. Davenport Acad. Sci.,
11: 1-124; Pls. 1-30.
EccLeTon, F. E. 1939. Réle of the bottom fauna in the productivity of lakes.
In Problems of lake biology. Amer. Assoc. Adv. Sci., Publ. No. 10: 123-181.
1939a. Freshwater communities. Amer. Mid]. Nat., 21: 56-74.
EHRENBERG, C. G. 1832. Die geographische Verbreitung der Infusionthierchen
in Nord-Afrika und West Asien. Abh. d. Phys. Kl. Konig]. Akad. Wiss. z.
Berlin, 1829: 1-20. 1832a. Beitrige zur Kenntniss der Organisation der In-
fusorien und ihre geographische Verbreitung besonders in Sibirien. Abh. d.
Kéngl. Akad. Wiss. z. Berlin, 1830: 1-88. 1832b. Ueber die Entwicklung und
Lebensdauer der Infusionsthiere; nebst ferneren Beitragen zu einer Verglei-
chung ihrer organischen Systeme. Phys. Abh. K6nigl. Akad. Wiss. z. Berlin,
1831: 1-154. 1835. Dritter Beitrag zur Erkenntniss grosser Organisation in der
Richtung des kleinsten Raumes. Abh. d. Konigl. Akad. Wiss. z. Berlin,
1833: 145-336. 1837. Zusatze zur Erkenntniss grosser organischer Aus-
bildung in den kKleinsten thierischen Organismen. Ibid., 1835: 151-180. 1838.
Die Infusionsthierchen als vollkommene Organismen. Leipzig. 1849. Beo-
bachtung zweier generisch neuer Formen der Friihlingsgewassers bei Berlin.
Monatsber. Konig]. Akad. Wiss. z. Berlin, 1848: 233-247.
Ercuwa.p, V. 1847. Erster Nachtrag zur Infusorienkunde Russlands. Bull. Soc.
Imp. Nat. Moscou, 20: 285-366. 1849. Ibid., 2. Ibid., 22: 400-548. 1852.
Ibid. 3. Ibid., 25: 388-536.
Exenxin, A. A. 1909. Neue, seltene oder interessante Arten und Formen der
Algen in Mittel-Russland 1908-1909 gesammelt. Bull. Jard. Imp. Bot. Pierre
le Grand, 9(No. 6): 121-154. 1915. [Note sur une algue nouvelle Leptobasis
caucasica mihi (nov. gen. et sp.) suivé de la révision critique de genre
Microchaete Thur.] Ibid., 15(No. 1): 5-22. 1922. Calothrix Ramenskii mihi
nov. sp. Not. Syst. Inst. Crypt. Horti Bot. Petropol., 1(No. 1): 6-9. 1922a.
De nova specie Aulosirae notula. Ibid., 1(No. 8): 127-128. 1923. De
Chroococcacearum classificatione notula. Ibid., 2(No. 4): 49-62. 1923a.
Schema Chroococcacearum classificationis. Ibid., 2(No. 5): 65-69. 1923b.
De gen. Anabaenopsis (Woloszynska ) Miller notula. Ibid., 2(No. 5): 73-78.
1924. De spec. duabus gen. Microcystis Kiitz. notula. Ibid., 3( No. 1): 12-15.
1924a. Descriptio specierum formarumque novarum e gen. Characium A.
Braun et Characiopsis Borzi cum Crustaceis symbioticis. Ibid., 3( No. 8):
33-36. 1924b. De Euglenarum sine flagello sectione nova. I-II. Ibid.,
8(No. 9/10): 129-160.
Evenxin, A. A., and Hotiersacu, M. M. 1923. De Coelosphaerio Naegeliano
Unger nonnullisque speciebus hujus generis et de Gomphosphaeria Kuetz.
notula. Not. Syst. Inst. Crypt. Horti Bot. Petropol., 2(No. 10): 145-155.
1923a. Schema specierum gen. Gomphosphaeriae Kuetz. et Coelosphaerii
(Naeg.) nob. emend. Ibid., 2(No. 10): 155-157.
Evenxin, A. A., and Ont, Lypia. 1926. Die Fortschutte der floristischen
algologie in USSR wahrend der letzten 25 Jahre. Ver. Inter. Vereinig. f.
Theoret. u. Angew. Limnol., 3: 166-177.
Evenxin, A. A., and Starx, N. V. 1923. De Asterocyti ramosa (Thwait) Gobi
caeterisque speciebus hujus generis notula. Not. Syst. Inst. Crypt. Horti Bot.
Petropol., 2(No. 8): 117-128.
E-Nayat, A. A. 1935. Egyptian freshwater algae. Egyptian Univ. Bull. Fac.
Sci., No. 4: 1-106; Figs. 1-143. 1939. On some new freshwater algae from
Egypt. Rev. Algol., 8: 311-319.
[ 623 ]
Entz, G. 1909. Ueber die Organisationsverhiltnisse Peridineen. Math.-Natur.
Berichte aus Ungarn, 25(1907): 246-274. 1926. Beitrage zur Kenntnis der
Peridineen. I. Zur Morphologie und Biologie von Peridinium Borgei Lem-
mermann. Arch. f. Protist., 56: 397-416. 1927. Beitrage zur Kenntnis der
Peridineen. II. resp. VII. Studien an Siisswasser-Ceratien. Ibid., 58: 344-440.
Ernst, A. 1902. Siphoneen-Studien. 1. Dichotomosiphon tuberosus (A. Br.)
Ernst, eine neue oogame Siisswasser-Siphonee. Beih. Bot. Centralbl., 138:
115-148; Pls. 6-10. 1904. Siphoneen-Studien. III. Zur Morphologie und
Physiologie der Fortpflanzungszellen der Gattung Vaucheria DC. Ibid., 16:
367-382; Pl. 20. 1908. Beitrage zur Morphologie und Physiologie von
Pithophora. Ann, Jard. Bot. Buitenzorg, 22: 18-55; Pls. 1-4.
EsMarcH, FERDINAND. 1914. Untersuchungen iiber die Verbreitung der Cyano-
phyceen auf und in verschiedenen Boden. Hedwigia, 55: 224-273.
Fartow, W. G. 1877. Remarks on some algae found in the water supplies of
the city of Boston. Bull. Bussey Inst., 2: 75-80. 1883. Relations of certain
forms of algae to disagreeable tastes and odors. Science, 2: 333-334.
Fassett, N. C. 1930. The plants of some northeastern Wisconsin lakes. Trans.
Wis. Acad. Sci., Arts, and Letters, 25: 157-168.
Fircu, C. P., BisHor, Lucie M., et al. 1934. “Water bloom” as a cause of
poisoning in domestic animals. Cornell Veterinarian, 24: 31-40.
Fyerpincstap, E. 1945. Planktonstudien. I. Zur Ausbreitung der Microcystis
aeruginosa Kiitz. emend. W. L., Microcystis flos-aquae (Wittr.) Kirchner
emend. W.-L. und Microcystis viridis (A. Br.) Lemmermann. II. Das phyto-
plankton im Vejle So im Sommer 1943 nebst einigen systematischen und
biologischen Bemerkungen. Dansk. Bot. Ark., 12(No. 1): 1-21.
FLAHAuLt, Cu. 1887. Note sur les Nostocacées hétérocystées de la flore Belge.
Bull. Soc. Roy. Bot. Belgique, 26( Pt. II): 171-179.
FLANicon, THomas H. 1943. Limnological observations on three lakes in
eastern Vilas County, Wisconsin. Trans. Wis. Acad. Sci., Arts and Letters,
34: 167-175.
Func, Eva M. 1939. One hundred algae of West Virginia. Castanea, 4: 5},
Fuint, L. H. 1947. Studies of freshwater red algae. Amer. Jour. Bot., 34(No.
3): 125-131; Figs. 1-31. 1948. Ibid., 85(No. 7): 428-433; Figs. 1-40.
FLotow, J. von. 1844. Beobachtungen iiber Haematococcus pluviatilis. Nova
Acta Acad. Caes. Leop.-Carol., 20: 413-606; Pls. 24-26.
Focc, G. E. 1942. Studies on nitrogen fixation by blue-green algae. I. Nitrogen
fixation by Anabaena cylindricum Lemm. Jour. Exper. Biol., 19: 78-87.
Forti, A. 1907. Sylloge Myxophycearum. In G. B. DeToni, Sylloge algarum.
V. Padua.
Franze&, R. H. 1892. Beitriige zur Morphologie des Scenedesmus. Termés-
ztrajzi Fiizetek kiadja a Magyar Nemzeti Muzeum, 15: 144-165. 1892a.
Zur Systematik einiger Chlamydomonaden. Ibid., 15: 273-286. 1893. Ueber
einige Algenformen. Oesterr. Bot. Zeit., 43: 202-205, 247-252, 282-286,
346-350, 381-386.
FREEMAN, E. M. 1899. Observations on Chlorochytrium. Minn. Bot. Studies,
2(No. 16): 195-204.
Fremy, P. 1922. Algues de l'Afrique centrale équatoriale. Bull. Soc. Bot. Linn.
Normandie, 5: 25-26. 1924. Contribution a la flore algologique de l'Afrique
équatoriale francaise. Rev. Algol., 1: 28-49. 1927. Les Scytonémacées de la
France. In Flore algologique de France, Cyanophycées. Fasc. 1. Paris and
Saint-L6. (Ibid. 1925. Rev. Algol., 2: 258-279. 1926. Ibid., 3: 55-98.)
1927a. Species des Stigonemacées de Normandie: Fischerella, Stigonema,
Capsosira, Nostochopsis. Bull. Soc. Linn. Bot. Normandie, 9: 41-44. 1930.
[ 624 ]
Les Myxophycées de l’Afrique équatoriale frangaise. 507 pp.; Figs. 1-362.
Thesis. Caen. 1930a. Algues provenant des récoltes de M. Henri Gadeau de
Kerville dans le canton de Bagnéres-de-Luchon (Haut-Garonne). Bull.
Soc. Amis Sci. Nat. Rouen, 1928-1929: 159-227; Figs. 1-139. 1936. Une
nouvelle Cyanophycée précipitant de Yoxyde de fer. Microcoleus ferrugineus
Frémy n. sp. Acta Inst. Bot. Univ. Zagreb., 11: 58-62; Figs. 1-7. 1936a. Les
Lyngbyées de la Normandie. Soc. d’Archeol. et d’Hist. Nat. Dept. de la
Manche, 47: 116-188; Figs. 1-18. 1938. Algues d’eau douce & subaériennes
des anciennes antilles danoises. D’aprés les récoltes de M. le Dr. Boergesen.
Mém. Soc. Nation. Sci. Nat. et Math. Cherbourg, 43: 37-62; Figs. 1-6.
FrEsENtvs, G. 1851. Ueber Sphaeroplea annulina. Bot. Zeit., 9: 241-248; Pl. 6.
1858. Beitrage zur Kenntniss mikroskopischer Organismen. Abh. Senck. Nat.
Ges., Frankfurt A.M., 2: 211-242.
Frizs, E. M. 1825. Systema orbis vegetabilis. Plantae homonemeae. 374 pp:
Fritscu, F. E. 1902. Algological notes. I. Observations on species of Aphano-
chaete. II. The germination of zoospores in Oedogonium. Ann. Bot., 16:
403-417; Figs. 1-7, 23. 1902a. Algological notes.—III. Preliminary report
on the phytoplankton of the Thames. Ibid., 16: 576-584. 1903. Further
observations on the phytoplankton of the River Thames. Ibid., 17: 631-647.
1905. Algological notes. VI. The plankton of some English rivers. Ibid., 19:
163-167. 1907. A general consideration of the subaérial and fresh-water
algal flora of Ceylon, Part I. Subaérial algae and algae of the inland fresh-
waters. Proc. Roy. Soc. London (B), 79: 197-254 .1907a. The subaérial and
freshwater algal flora of the tropics. Ann. Bot., 21: 235-275. 1914. Notes
on British flagellates. I-IV. New Phytol., 13: 341-351. 1916. The algal
ancestry of the higher plants. Ibid., 15: 233-250; Figs. 1,2. 1918. A con-
tribution to our knowledge of the fresh-water algae of Africa. Ann. S.
African Mus., 9: 483-611. 1929. The encrusting algal communities of certain
fast-flowing streams. New Phytol., 28: 165-196. 1929a. Evolutionary se-
quence and affinities among protophyta. Biol. Rev. and Biol. Proc. Cambridge
Philos. Soc., 4: 103-151; Figs. 1-7. 1929b. The genus Sphaeroplea. Ann.
Bot., 43: 1-26; Figs. 1-8. 1931. Some aspects of the ecology of fresh-water
algae. Jour. Ecol., 19: 233-272. 1935.+ The structure and reproduction of
the algae. I. 791 pp.; Figs. 1-245. New York. 1942. The interrelations and
classification of the Myxophyceae (Cyanophyceae). New Phytol., 41:
134-148; Figs. 1-5. 1945.+ The structure and reproduction of the algae. II.
939 pp.; Figs. 1-335. New York.
Fritscu, F. E., and Der, P. K. 1938. Nitrogen fixation by blue-green algae.
Nature, 142: 878.
Fritscu, F. E., and Jonn, R. P. 1942. An ecological and taxonomic study of
the algae of British soils. II. Consideration of the species observed. Ann.
Bot., 6(n.s.): 371-395; Figs. 1-8.
Fritscu, F, E., and Rich, FLoreNce. 1913. Studies on the occurrence and re-
production of British freshwater algae in nature. 3. A four year’s observation
of a freshwater pond. Ann. Biol. Lacustre, 6: 33-115. 1930. Contributions
to our knowledge of the freshwater algae of Africa. 7. Freshwater algae
(exclusive of diatoms) from Griqualand West. Trans. ny Soc. S. Africa,
18(1929): 1-92; Figs. 1-32. 1937. Contributions to our knowledge of the
freshwater algae of Africa. 12. Algae from the Belfast Pan, Transvaal. Ibid ,
25( Pt. IL): 153-228; Figs. 1-31.
Fritscn, F. E., and StepHens, Epiru L. 1921. Contributions to our knowledge
of the freshwater algae of Africa. 2. Fresh-water algae (exclusive of diatoms),
[ 625 ]
mainly from the Transkei Territories, Cape Colony. Trans. Roy. Soc. S.
Africa, 9(Pt. 1): 1-72; Figs. 1-29.
Frirscu, F. E., and Taxepa, H. 1916. On a species of Chlamydomonas (C.
sphagnicola F. E. Fritsch and Takeda—Isococcus sphagnicolus, F. E.
Fritsch). Ann Bot., 30: 373-377; Figs. 1-12.
Gamwukxov, N. 1903. Ueber die Kulturen und die Uronema-Zustand der Ulothrix
flaccida. Ber. d. Deutsch. Bot. Ges., 21: 522-524.
Garsint, A. 1899. Intorno al plankton dei laghi di Mantova. Atti e Mem. Accad.
Verona, 74(Ser. 3) Fasc. 3: 255-314. 1901. Intorno plankton del Lago
Maggiore. Ibid., 76(Ser. 3), Fasc. 2: 67-80.
Garp, M. 1920. Division chez Euglena limosa Gard. Comp. Rend. Acad. Sci.
Paris, 170: 291-292. 1922. Recherches sur une nouvelle espéce d’Euglene
(Euglena limosa nov. spec.). Bull. Soc, Bot. France, 69: 306-313.
Garpner, N. L. 1927. New Myxophyceae from Porto Rico. Mem. N. Y. Bot.
Gard., 7: 1-144.
Gates, F. C. 1912.* The vegetation of the beach area in northeastern Illinois
and southeastern Wisconsin. Bull. Ill. State Lab. Nat. Hist., 9: 255-372.
Gay, F. 1888. Sur les Ulothrix aériens. Bull. Soc. Bot. France, 35: 65-75. 1891.
Recherches sur le développement et la classification de quelques algues
vertes. 116 pp.; Pls. 1-15. Paris. 189la. Le genre Rhizoclonium. Jour. Bot.
5: 538-58.
GeirLer, L. 1921. Versuch einer Lésung des Heterocysten-Problems. Sitz. K.
K. Akad. Wiss. Wien, Math.-Nat. KI., 130: 223-245. 192la. Kleine Mitteil-
ungen uber Blaualgen. Oesterr. Bot. Zeit., 70: 158-167; Figs. 1-7. 1923.
Studien iiber das Hamatochrom und die Chromatophoren von Trentepohlia.
Ibid., 72: 76-83; Figs. 1-5. 1923a. Der Zellbau von Glaucocystis Nostochin-
earum und Gloeochaete Wittrockiana und die Chromatophoren-Symbios-
theorie von Mereschkowsky. Arch. f. Protist., 47: 1-24; Pl. 1. 1924. Die
Entwicklungsgeschichte von Sorastrum spinulosmum und die Phylogenie der
Protococcales. Ibid., 47: 440-447; Pl. 22. 1925. Beitraége zur Kenntnis der
Flora ostholsteinischer Seen. Ibid., 52: 603-611. 1925a. Cyanophyceae. In
A. Pascher, Die Siisswasserflora Deutschlands, Oesterreichs und der Schweiz.
Heft 12: 1-450; Figs. 1-560. 1925b. Ueber neue oder wenig bekannte
interessante Cyanophyceen aus der Gruppe der Chamaesiphoneae. Arch. f.
Protist., 51: 321-360; Pls. 12, 13. 1928. Neue Blaualgen aus Lunz. Ibid., 60:
440-448. 1928a. Zwei neue Dinophyceenarten. Ibid., 61: 1-8. 1928b. Neue
Gattungen und Arten von Dinophyceen, Heterokonten und Chrysophyceen.
Ibid., 63: 67-83; Pl. 7. 1930. Ueber die Kernteilung von Spirogyra. Ibid.,
71: 79-100. 1930-1931.+ Cyanophyceae. In L. Rabenhorst, Kryptogamen-
Flora von Deutschland, Oesterreich und der Schweiz. 14, Lf. 1( 1930): 1-288;
Lf. 2(1931): 289-464; Figs. 1-131. Leipzig. 193la. Untersuchungen iiber
das sexuelle Verhalten von Tetraspora lubrica. Biol. Centralbl., 51: 173-187;
Figs. 1-5.
Getus, S. S., and Crarxe, G. L. 1935. Organic matter in dissolved and in
colloidal form as food for Daphnia magna. Physiol. Zool., 8: 127-137.
GeMEInHarpT, K. 1938-1939.t Oedogoniales. In L. Rabenhorst, Kryptogamen-
Flora von Deutschland, Oesterreich und der Schweiz. 12, Abt. 4: 1-453;
Figs. 1-539. Leipzig.
Gervorr, J. 1940. Beitrage zur Kenntnis der Variabilitét und Systematik der
Gattung Chlamydomonas. Arch. f. Protist., 94: 311-502; Figs. 148.
Gernecx, R. 1907. Zur Kenntnis niederen Chlorophyceen. Beih. Bot Centralbl ,
21( Abt. 2): 221-290; Pls. 11, 12.
[ 626 ]
GicktHorn, J. 1921. Ueber den Blauglanz zweier neuer Oscillatorien. Oesterr.
Bot. Zeit., 70: 1-11.
Gmes1, N. 1930. Die Geburt von Trachelomonas volvocina Ehrb. Arch. f.
Protist., 72: 190-197; Pl. 14.
Ge.in, C. G. 1826. Flora Badensis Alsatica. IV: 643-647. Carlsruhe. (Not
seen. )
Gost, C. 1879. Kurzer Bericht iieber die im Sommer 1878 ausgefiihrte algolo-
gische Excursion (rossice). St. Petersb. Ges. d. Naturf., 10: 93-97. 1886-
1887. Peroniella Hyalothecae, eine neue Siisswasseralge. Script. Bot. Hort.
Petropol., 1(Fasc. 2): 233-250; 1 pl.
Gorz, H. 1897. Zur Systematik der Gattung Vaucheria DC. speciell der Arten
der Umgebung Basels. Flora, 83: 88-134; Figs. 1-55.
Goynics, Mary. 1934. The cell morphology and division of Euglena deses
Ehrbg. Trans. Amer. Microsc. Soc., 53: 999-310; Pls. 21-23. 1939. Some
observations on Euglena sanguinea Ehrbg. Ibid., 58: 241-248; 1 pl.
Gotenkin, M. 1899. Algologische Mitteilungen. Ueber die Befruchtung bei
Sphaeroplea annulina und iiber die Struktur bei einigen grunen Algen. Bull.
Soc. Imp. Nat. Moscou, 13: 343-361.
Gomont, M. 1885. Sur deux algues nouvelles des environs de Paris. Bull. Soc.
Bot. France, 32: 208-212. 1890. Essai de classification des Nostocacées
homocystées. Jour. Bot., 4: 349-357. 1892. Monographie des Oscillariées
(Nostocacées homocystées). Part 1. Ann. Sci. Nat. Bot., 15(Sér. 7): 263—
368; Pls. 6-14. 1892a.t+ Monographie des Oscillariées. Part 2. Ibid., 16(Sér
7): 91-264; Pls. 1-7. 1893.+ Monographie des Oscillariées (Nostocacées
homocystées). Paris. 1895. Note sur le Scytonema ambiguum Kiitz. Jour.
Bot., 9: 49-53. 1895a. Note sur un Calothrix sporifere (Calothrix stagnalis
sp. n.). Ibid., 9: 197-202.
GoroscHankn, J. 1891. Beitriige zur Kenntnis der Morphologie und Systematik
der Chlamydomonaden. I. Chlamydomonas Braunii. Bull. Soc. Imp. Nat.
Moscou, 1890 (No. 3): 498-520; Pls. 14,15. 1891. Beitrage zur Kenntniss
der Morphologie und Systematik der Chlamydomonaden. I. Chlamydomonas
- Reinhardii (Dangeard) und seine Verwandten. Pls. 1-8. Moskau.
Grecer, J. 1915. Beitrag zur Kenntnis der Entwicklung und Fortpflanzung der
Gattung Microthamnion Naeg. Hedwigia, 56: 374-380.
Grevitte, k. K. 1824. Flora Edinensis. Edinburgh. 1830, Algae britannicae.
Edinburgh.
Grirrirus, B. M. 1912. The algae of Stanklin Pool, Worcestershire; an account
of their distribution and periodicity. Proc. Birmingham Nat. Hist. and Phil.
Soc., 12: 1-23. 1915. On Glaucocystis Nostochinearum, Itzigsohn. Ann. Bot.,
29: 423-432; Pl. 19.
Groves, J., and Buttock-WessTER, G. R. 1920-1924.+ The British Charophyta.
I, 1920; II, 1924. Ray Society, London.
Grunow, A. 1858. Die Desmidiaceen und Pediastreen einiger Oesterreichischen
Moore, nebst einigen Bemerkungen iiber beide Familien im Allgemeinen.
Ver. K. K. Zool.-Bot. Ges. Wien, 8: 489-502. 1867. Algen. Leipzig.
Ginruer, F. 1928. Ueber der Bau und die Lebensweise der Euglenen, besonders
der Arten E. terricola, geniculata, proxima, sanguinea und lucens nov. spec.
Arch. f. Protist., 60: 511-590; Pls. 13-15; Figs: 1-5.
Guciie_metti, G. 1910. Contribuzioni alla flora algologica Italiana. I. Proto-
coccaceae raccolte nel Padovano. Nuova Notarisia, 21: 28-39.
Gusrarson, A. H. 1942.* Notes on the algal flora of Michigan. Pap. Mich.
Acad. Sci., Arts and Letters, 27(1941): 27-36. 1942a. Notes on some fresh-
water algae from New England. Rhodora, 44: 64-69.
[ 627 ]
Gutwinski, R. 1890. Zur Wahrung der Prioritiét. Vor laiifige Mittheilungen
iiber einige neue Algen-Species und Varietaéten aus der Umgebung von
Lemberg. Bot. Centralbl., 43: 65-73. 1893. Glony stawé6w na Zbruczu.
Akad. Umiej. w Krakowie Spraw. Komisyi Fizyogr., 29: 23-28. 1894. Flora
glonow okolic Tarnapola. Ibid., 30: 45-173. 1894a. Glony stawow na
Zbruczu (Ueber die in den Teichen des Zbrucz-Flusses gesammelten Algen).
Ibid., 29: 23-38. 1896. De nonnulis algis novis vel minus cognitis. Akad.
Umiej. w Krakowie, Rozpr. Wydz. Mat.-Przyr. 83: 82-63. 1897. Materyaly
do flory Glonow Galicyi. Res ad floram algarum Galiciae congestae. Pars
IV. A. Algae a Prof. Arsenio Dorozynski in Mizun ad Dolina anno 1896
collectae. B. Algae a Prof. Francisco Tondera in Knihynin ad Stanislowé6w
anno 1894 collectae. Nuova Notarisia, 8: 125-136. 1900. Additamenta ad
floram algarum Indiae Batavorum cognoscendam. Algae a cl. Dre. M. Raci-
borski in montibus vulcanis: Kraktau et Slamat anno 1897 collectae. Diss.
Mat.-Physic. Acad. Litter. Cracoviens, 89: 287-307; Anz. Akad. Wiss.
Krakau, 1900. 400-402. 1902. De algis a Dre. M. Raciborski anno 1899. in
insula Java collectis. Bull. Inter. Acad. Sci. Cracovie, Cl. Sci. Math. et Nat.,
1902: 575-617; Pls. 36-40. 1909. Flora algarum montium Tatrensium. Ibid.,
4: 415-560. 1913. Ueber die Algenflora und das Plankton des Tatra-Sees
“Morskie Oko’. Kosmos, 1923: 1426-1437 (reprint).
Haase, G. 1910. Studien iiber Euglena sanguinea. Arch. f. Protist., 20: 47-59;
Pls. 4-6.
Hare, Frank E. 1930. Control of microscopic organisms in public water
supplies, with particular reference to New York City. New Eng. Water Works
Assoc., 44: 361-385.
Hatxas, E. D. 1905. Nye Arter af Oedogonium fra Danmark. Bot. Tids., 26:
3897-410.
Hamet, G. 1925. Floridées de France. III. Rev. Algol., 2: 839-67, 280-309.
Hami.ton, J. M. 1948. Sexual reproduction in the genus Basicladia (Thallo-
phyta) Chlorophyceae. Trans. Amer. Microsc. Soc. 67: 201-205; Figs. 1-9.
Hanscirc, A. 1883. Beitrage zur Kenntniss der Flora von Bohmen. I, II. Sitz.
d. Konig]. Bohm. Ges. d. Wiss. Math.-Nat. Kl. Prag, 1882: 280-289. 1883a.
Neue Beitrage zur Algenkunde Bohmens. Ibid., 1883: 203-211; Neue
Beitrage zur Kenntniss bohmischer Algen. Ibid., 1883: 263-273; Neue
Beitrage zur Kenntniss der béhmischen Algenflora. Ibid., 1883: 360-371.
1885. Anhang zu meiner Abhandlung “Ueber Polymorphismus der Algen.”
Bot. Centralbl., 23: 229-233. 1885a. Ueber den Polymorphismus der Algen.
Ibid., 23: 385-406. 1886.+ Prodromus der Algenflora von Béhmen. Erster
Theil enthaltend die Rhodophyceen, Phaeophyceen und einen Theil der
Chlorophyceen. Heft 1. Archiv f. Natur. Landes von Béhm., 5( Bot. Abth.):
3-96; Figs. 1-126. 1887. Ueber Trentepohlia (Chroolepus) artige Moosvor-
keimbildungen. Flora, 70: 81-85. 1887a. Algarum aquae dulcis species
novae. Oesterr. Bot. Zeit., 37: 121-122. 1888.+ Prodromus der Algenflora
von Bohmen. Erster Theil enthaltend die Rhodophyceen, Phaeophyceen und
Chlorophyceen. Heft 2. Archiv f. Natur. Landes von Béhm., 6(No. 5):
3-290. 1888a. Ueber die Siisswasser-gattungen Trochiscia Ktz. (Astericium
Corda, Polyedrium Nag., Cerasterias Reinsch). Hedwigia, 27: 126-132.
1888b. Synopsis generum subgenerumque Myxophycearum (Cyanophycea-
rum) hucusque cognitorum, cum descriptione generis nov. “Dactylococcop-
sis.” Notarisia, 3: 584-590. 1888c. Beitrag zur Kenntniss der Algengattungen
Entocladia Reinke, etc. Flora, 71: 499-507; Pl. 12. 1888d. De Spirogyra
insigni (Hass.) Ktz. nov. var. fallaci, Zygnemate chlabeospermo nov. sp. et
[ 628 ]
Z. rhynconemate nov. sp., aijecto conspectu subgenerum. sectionum, sub-
sectionumque generis Spirogyrae Link et Zygnematis (Ag.) DeBy. Hedwigia,
27: 253-258; Pl. 10. 1888e. Algae novae aquae dulcis. Notarisia, 3(No. 9):
398-400. 1888f. Ueber die Gattungen Herpostiron Nag. und Aphanochaete
Berth. non A. Br., etc. Flora, 71: 211-223. 1889. Nachtrage zu den in
Hedwigia 1888, No. 5 und 6, No. 9 und 10 verdffentlichten Abhandlungen.
Hedwigia, 28: 17-19. 1889a. Resultate der vom Verfasser im J. 1888 ausge-
fihrten Durchforschung, der Siisswasseralgen und der saprophytischen Bac-
terien Bohmens. Sitz. d. Konig]. Bohm. Ges. d. Wiss. Math.-Nat. Kl. Prag,
1889: 121-164. 1890. Uber neue Siisswasser- und Meeres-Algen und Bac-
terien, mit Bemerkungen zur Systematik dieser Phycophyten und iiber den
Einfluss des Lichtes auf die Ortsbewegungen des Bacillus Pfefferi, nob. Ibid.,
1890: 1-34. 1890a. Physiologische und algologische Mittheilungen. Ibid.,
1890: 83-140. 1891. Algologische und bacteriologische Mittheilungen. Ibid.,
1891: 300-365. 1892[1893]. Prodromus der Algenflora von Bohmen. Zweitet
Theil welcher die blaugriinen Algen (Myxophyceen, Cyanophyceen), nebst
Nachtragen zum ersten Theile und einer systematischen Bearbeitung der in
Béhmen verbreiteten saprophytischen Bacterien und Eugleenen enthalt.
Archiv f. Natur. Landes von Bohm., 8(Bot. Abth.): 1-268; Figs. 1-67.
1892a. Beitrage zur Kenntnis der Siisswasser-Algen und Bacterien-Flora
von Tirol und Béhmen. Sitz. d. Konig]. Béhm. Ges. d. Wiss. Prag, 1892:
105-156. 1893. Mein letztes Wort iiber Chaetosphaeridium Pringsheimii
Kleb. und Aphanochaete globose (Nordst.) Wolle. Bot. Centralbl., 56:
321-326. 1905. Grundziige der Algenflora von Niederosterreich. Beih. Bot.
Centralbl., 18: 417-522.
Harior, P. 1889-1890. Notes sur le genre Trentepohlia Martius. Jour. Bot.,
3(1889): 345-350, 366-375, 378-388, 393-405. Ibid., 4(1890): 50-53,
85-92, 178-189, 192-197; Figs. 1-24. 1891. Le genre Polycoccus Kuetzing.
Ibid., 5: 29-32. 1895. Algues du Golfe de California. Ibid., 9: 167-170.
Harper, R. A. 1908.* Organization of certain coenobic plants. Bull. Univ. Wis.
No. 207(Sci. Ser., 3): 279-334; Pls. 1-4. 1916. On the nature of types in
Pediastrum. Mem. N. Y. Bot. Gard., 6: 91-104; Figs. 1, 2. 1918. Organisation,
reproduction, and inheritance in Pediastrum. Proc. Amer. Philos. Soc., 57:
375-439; Pls. 5-6. 1918a. The evolution of cell types and contact and
pressure responses in Pediastrum. Mem. Torr. Bot. Club, 17: 210-240;
Figs. 1-27.
Harvey, F. L. 1888. The freshwater algae of Maine. I. Bull. Torr. Bot. Club,
15: 155-161. 1889. Ibid. Il. Ibid., 16: 181-188. 1892. Ibid. II. Ibid., 19:
118-125.
Harvey, H. W. 1926. Nitrates in the sea. Jour. Mar. Biol. Assoc., 14: 71—88.
Harvey, W. H. 1833. Algae Gloiocladeae. In Hooker’s British Flora, 5: 385-
400. London. 1855-1859. In J. D. Hooker, The botany of the antarctic
voyage. Part III. Flora Tasmania. 1858. Nereis Boreali-Americana. Ill.
Chlorospermeae. Smiths. Contrib. Knowledge, 10( No. 2): 1-140; Pls. 37-50.
Hassatx, A. H. 1842. Observations on the genera Zygnema, Tyndaridea and
Mougeotia, with descriptions of new species. Ann. and Mag. Nat. Hist.,
10(Ser. 1): 34-47. 1843. Descriptions of British freshwater Confervae,
mostly new, with observations on some of the genera. Ibid., 11(Ser. 1):
428-437. 1843a. Observations on some points in the anatomy and physiology
of the freshwater algae. Ibid., 12(Ser. 1): 20-30; 1 pl. 1843b. Observations
on the genus Mougeotia, on two new genera of fresh water algae, and on
Tyndaridea, with descriptions of species. Ibid., 12(Ser. 1): 180-188; 1 pl.
1843c. Observations on the growth, reproduction, and species of the
branched fresh-water Confervae. Ibid., 11(Ser. 1): 359-364. 1845. A history
[ 629 ]
of fresh-water algae. 462 pp.; Pls. 1-103. London. 1852. A history of the
freshwater algae, including descriptions of Desmidiaceae and Diatomaceae.
2 vols. 462 pp.; Pls. I-CIII. London.
Hasstow, O. J. 1939. Einige Characeenbestimmungen. Bot. Notiser, 1939:
295-301, 817-818.
Hauck, F. 1885. Die Meeresalgen Deutschlands und Oesterreichs. In Raben-
horst’s Kryptogamenflora. II. Leipzig.
Haypen, Apa. 1910. The algal flora of the Missouri Botanical Garden. 21st
Ann. Rep. Missouri Bot. Gard., 1910: 25-48; Pls. 1-5.
Hazen, Tracy E. 1899. The life history of Sphaerella lacustris (Haematococcus
pluvialis). Mem. Torr. Bot. Club, 6: 211-224; Pls. 86-87. 1902. The Ulo-
thricaceae and Chaetophoraceae of the United States. Ibid., 11: 135-250;
Pls. 20-42.
HeeErInG, W. 1906. Die Siisswasseralgen Schleswig-Holstein, etc. Jahrb. Ham-
burg. Wiss. Anstal., 23(1905): 61-150. 1914.+ Ulotrichales, Microsporales,
Oedogoniales. In A. Pascher, Die Siisswasserflora Deutschlands, Oesterreichs
und der Schweiz. Heft 6. Chlorophyceae 3: 1-250; Figs. 1-384. Jena. 1921.+
Siphonocladiales, Siphonales. Ibid. Heft 7. Chlorophyceae 4: 1-103; Figs.
1-94. Jena.
HeeErinc, W., and Homrexp, H. 1905. Die Algen des Eppendorfer Moores bei
Hamburg. Ver. Natur. Ver. in Hamburg, 12(1904): 77-97.
HernricuEer, E, 1883. Zur Kenntniss der Algengattung Sphaeroplea. Ber. d.
Deutsch. Bot. Ges., 1: 483-450; Pl. 12.
Henrrey, A. 1859. On Chlorosphaera, a new genus of uni-cellular fresh-water
algae. Trans. Microsc. Soc. London, 7(n.s.): 25-29; Pl. 3.
Henrici, A. T. 1938. Studies of freshwater bacteria. IV. Seasonal fluctuations
of lake bacteria in relation to plankton production. Jour. Bact., 35: 129-139.
1939. The distribution of bacteria in lakes. In Problems of lake biology.
Amer. Assoc. Adv. Sci., Publ. No. 10: 39-64.
Henrici, A. T., and McCoy, ExizasetH. 1938. The distribution of hetero-
trophic bacteria in the bottom deposits of some lakes. Trans. Wis. Acad. Sci.,
Arts, and Letters, 31: 323-361.
HERMANN, J. 1863. Ueber die bei Neudamm aufgefundenen Arten der Genus
Characium. Leipzig.
Hirronymus, G. 1887. Ueber einige Algen des Riesengebirges. Jahr. Schles.
Ges. Vater. Kul., 1887: 293-297. 1892. Ueber Dicranochaete reniformis
Hieron., eine neue Protococcacea des Siisswassers. Beitr. Biol. Pflanzen., 5:
351-372; Pls. 11, 12. 1892a. Beitraége zur Morphologie und Biologie der
Algen. I. Glaucocystis Nostochinearum Itzigsohn. Ibid., 5: 461-495. 1895.
Bemerkungen iiber einige Arten der Gattung Stigonema Ag. Hedwigia, 34:
154-172.
HicrnsotHaM, Nor. 1942. Cephalomonas, a new genus of the Volvocales. Bull.
Torr. Bot. Club, 69: 661-668; Figs. 1-43.
Hirn, Kart E. 1895. Verzeichnis finlandischer Oedogoniacéen. Acta Soc.
Fauna et Flora Fenn., 11(No. 6): 1-24. 1895a. Die Finnlandischen Zygne-
maceen. Ibid., 11(No. 10): 1-15. 1900.+ Monographie und iconographie der
Oedogoniaceen. Acta Soc. Sci. Fenn., 27: 1-395; Pls. 1-64; Figs. 1-27.
1900a. Finnlindische Vaucheriaceen. Medd. Soc. Fauna et Flora Fenn.,
26(1900): 1-6 (reprint).
Hopcetts, W. J. 1918. Uronema elongatum, a new fresh water member of the
Ulotrichaceae. New Phytol., 17: 159-166; Figs. 1-11. 1921. A study of
some of the factors controlling the periodicity of fresh-water algae in nature.
Ibid., 20: 150-164, 195-227. 1922. Ibid., 21: 15-38; Figs. 1-11.
[ 630 ]
HorrMan, W. E., and TILDEN, JOSEPHINE. 1930. Basicladia, a new genus of
Cladophoraceae. Bot. Gaz., 89: 374-384; Figs. 1-22.
Horan, R. M., and Reep, E. 1918.* Notes on the phytoplankton and other
algae of Douglas Lake and vicinity. Ann. Rep. Mich. Acad. Sci., 20:
153-154.
Hooker, J. D. 1855-1859. The botany of the antarctic voyage. Part III.
Flora Tasmaniae.
Hooxer, W. J. 1833. The English flora. 5. Part 1. 432 pp. London.
Hoppaucn, KATHERINE. 1930.t A taxonomic study of species of the genus
Vaucheria collected in California. Amer. Jour. Bot., 17: 8329-347; Pls. 24-27.
Huser, J. 1892. Contributions 4 la connaissance des Chaetophorées épiphytes
et endophytes et de leurs affinités. Ann. Sci. Nat. Bot., 16(Sér. 7): 265-
359; Pls. 8-18. 1894. Sur ! Aphanochaete repens A. Braun et sa reproduction
sexuée. Bull. Soc. Bot. France, 41(Sér. 3): XCIV—CII.
Hvuser-PestaLozzi, G. 1919. Morphologie und Entwicklungsgeschichte von
Gloeotaenium Loitelsbergerianum Hansgirg. Zeit. f. Bot., 11: 401-472. 1924.
Notiz iiber Gloeotaenium Loitelsbergerianum Hansgirg. Ibid., 16: 624-626.
1925. Zur Morphologie und Entwicklungsgeschichte von Asterothrix (Cera-
sterias) raphidioides (Reinsch) Printz. Hedwigia, 65: 169-178; Figs. 1-5.
1929. Das Phytoplankton naturlicher und kiinstlicher Seebecken Siidafrikas.
Ver. Inter. Vereining. f. Theor. u. Angew. Limnol., 4: 343-390. 1930. Algen
aus dem Knysnawalde in Siidafrika. Zeit. f. Bot., 23: 443-480. 1938.+ Das
Phytoplanktons des Siisswassers. Systematik und Biologie. 1 Teil. Stuttgart.
342 pp.; Pls. 3-66. 1941. Ibid. 2 Teil. Stuttgart.
Huser-Pestatozzi, G., and Naumann, E. 1929. Phormidium mucicola Nau-
mann et Huber, ein Epibiont in der Gallerte pflanzlicher und tierischer
Planktonorganismen. Ber. d. Deutsch. Bot. Ges., 47: 67-76.
Huesner, E. 1886. Euglenaceen-Flora von Stralsund. Progr. d. Realgymnasiums
zu Stralsund. Ostern.
Hurr, N. L. 1923. Observations on the relation of algae to certain animals of
Vadnais Lake. Univ. Minn. Biol. Sci., 4: 185-197.
Hucues, E. O. 1948. New fresh-water Chlorophyceae from Nova Scotia. Amer.
Jour. Bot., 35(No. 7): 424427; Figs. 1-6.
Hurrretpt-Kaas, H. 1900. Die limnetischen Peridineen in norwegischen Bin-
nenseen. Vidensk. Skrifter, Mat.-Nat. KI. Christiania, 1900(No. 2): 1-7.
Hurcuinson, G. Evetyn. 1944, Limnological studies in Connecticut. VII. A
critical examination of the supposed relationship between phytoplankton
periodicity and chemical changes in lake waters. Ecology, 25: 3-26.
Hyanper, C. J. 1928. The algae of Connecticut. Bull. Conn. Geol. and Nat.
Hist. Surv., 42: 1-245; Pls. 1-28.
Hy, T. C. 1913-1914. Les Characées de France. Bull. Soc. Bot. France,
60(1913. Mém. 26): 1-47. Note additionelle. Ibid., 61(1914): 235-241.
Imuor, O. E. 1887. Studien iiber die Fauna hochalpiner Seen, insbesondere
des Cantons Graubiinden. Jahrb. d. Naturf. Ges. Graubiindens, 30: 45-164.
1890. Das Flagellatengenus Dinobryon. Zool. Anz., 13: 483-488.
IsRAELSSON, GuNNAR. 1938. Ueber die Siisswasserphaeophyceen Schwedens.
Bot. Notiser, 1938, 113-128.
Irzicsonn, H. 1850. Charologisches. Bot. Zeit., 8: 337-340. 1855. Skizzen zu
einer Lebensgeschichte des Hapalosiphon Braunii. Acta Acad. Caes. Leop.-
Carol., 25: 249-298.
Iwanorr, L. A. 1898. Zur Entwicklungsgeschichte von Botrydium granulatum
Woronin et Rostaf. Trav. Soc. Imp. Nat. St. Pétersb. Comp. Rend., 29( No. 4):
155-156. (Not seen.) 1898a. Zur Entwicklungsgeschichte von Botrydium
[ 631 ]
granulatum Woronin et Rostaf. Arb. d. Kais. St. Petersb. Ges. d. Naturf., 29:
1-10. 1900. Ueber neue Arten von Algen und Flagellaten (Stigeoclonium,
Vaucheria, Spirogyra, Gonyostomum), welche an der biologischen Station
zu Bologoje gefunden worden sind. Bull. Soc. Imp. Nat. Moscou, 1899(No.
4): 423-449, 1900a. Beitrag zur Kenntnis der Morphologie und Systematik
der Chrysomonadinen. Bull. Acad. Imp. Sci. St. Pétersb. 11: 247-262; 1 pl.;
Figs. A, B.
IyeNcAR, M. O. P. 1923. Notes on some attached forms of Zygnemaceae. Jour.
Indian Bot. Soc., 2: 1-9. 1925. Note on two species of Botrydium from India.
Ibid., 4: 193-201. 1925a. Hydrodictyon indicum, a new species from Madras.
Ibid., 4: 315-317. 1933. Contributions to our knowledge of the colonial
Volvocales of South India. Jour. Linn. Soc. Bot., 49: 323-373.
Ivencar, M. O. P., and Ivencar, M. O. T. 1932 On a Characium growing on
Anopheles larvae. New Phytol., 31: 66-69.
Jaun, T. L. 1946. The euglenoid flagellates. Quart. Rev. Biol., 21: 246-274;
Figs. 1-6.
Janet, C. 1912. Le Volvox. Limoges. 1918. Botrydium granulatum. Limoges.
1922. Le Volvox. Deuziéme mémoire. Paris. 1923. Le Volvox. Troisieme
mémoire. 179 pp.; Pls. 5-21. Paris.
Jao, C. C. 1934. New Oedogonia collected in China. Pap. Mich. Acad. Sci.,
Arts, and Letters, 19(1933): 83-92; Pls. 5-7. 1934a. Oedogonium in the
vicinity of Woods Hole, Massachusetts. Rhodora, 36: 197-214; Pls. 286—
288. 1935. New Oedogonia collected in China. I. Pap. Mich. Acad. Sci.,
Arts, and Letters, 20(1934): 57-63; Pls. X, XI. 1935a. New Zygnemataceae
from Woods Hole. Trans. Amer. Microsc. Soc., 54: 1-7; Pl. 1. 1936. Notes
on Oedogonium and Bulbochaete in the vicinity of Woods Hole, Massa-
chusetts. Rhodora, 38: 67-73; Pl. 407. 1936a. New Zygnemataceae collected
in China. Amer. Jour. Bot., 23: 53-60.
Jorcensen, E. 1911. De Ceratien. Eine kurze Monographie der Gattung
Ceratium Schrank. Inter. Rev. d. Ges. Hydrobiol. u. Hydrogr., 4(Suppl.),
Pt. 1: 1-124.
Jounson, L. N. 1894.* Some new and rare desmids of the U.S. I. Bull. Torr.
Bot. Club, 21: 285-291. 1895.* Ibid. I. Ibid., 22: 289-298.
Jounson, L. P. 1944.+ Euglenae of Iowa. Trans. Amer. Microsc. Soc., 63:
97-135; Pls. 1-6.
Jotxos, V. 1910. Dinoflagellatenstudien. Arch. f. Protist., 19: 178-206; Pls. 7-10.
Josr, L. 1895. Beitriige zur Kenntniss der Coleochaeteen. Ber. d. Deutsch. Bot.
Ges., 18: 483-452; Pl. 34.
Jupay, C. 1914. The inland lakes of Wisconsin. The hydrography and mor-
phometry of the lakes. Bull. Wis. Geol. and Nat. Hist. Surv., 27 (Sci. Ser.
No. 9): 1-157. 1934.* The depth distribution of some aquatic plants.
Ecology, 15: 325. 1942. The summer standing crop of plants and animals
in four Wisconsin lakes. Trans. Wis. Acad. Sci., Arts, and Letters, 34:
103-135; Figs. 1-4.
Jupay, C., and Bircr, E. A. 1931. A second report on the phosphorus content
of Wisconsin lake waters. Trans. Wis. Acad. Sci., Arts, and Letters, 26:
353-382. 1941. Hydrography and morphometry of some northeastern Wis-
consin lakes. Ibid., 833: 21-72.
Jupay, C., Bice, E. A., Kemmerer, G. I., and Rosinson, R. J. 1927. Phos-
phorus content of lake waters of northeastern Wisconsin. Trans. Wis. Acad,
Sci., Arts, and Letters, 23: 233-248.
Jupay, C., Brrcr, E. A., and MELocHE, V. W. 1935. The carbon dioxide and
hydrogen ion content of the lake waters of northeastern Wisconsin. Trans.
[ 632 ]
Wis. Acad. Sci., Arts, and Letters, 29: 1-82. 1938. Mineral content of the
lake waters of northeastern Wisconsin. Ibid., 31: 223-276.
Jupay, C., and ScHomer, H. A. 1935.* The utilization of solar radiation by
algae at different depths in lakes. Biol. Bull., 69: 75-81.
Jurcens, G. H. B. 1822. Algae aquaticae. Dec. XV.
Just, L. 1822. Phyllosiphon Arisari. Bot. Zeit., 40: 1-8, 17-26, 33-47, 49-57;
Jelly Jt
Kammerer, G. 1938. Volvocalen und Protococcalen aus dem unteren Ama-
zonasgebiet. Sitz. K. K. Akad. Wiss. Wien. Math.-Nat. K]., 147(Abt. 1):
183-228.
Karsten, G. 1891. Untersuchungen ueber die Familie der Chroolepideen. Ann.
Jard. Bot. Buitenzorg, 10: 1-66; Pls. 1-6.
Kasanowsky, V., and Smienorr, S. 1913. Spirogyra borysthenica n. sp. Oest.
Bot. Zeit., 63: 137-141.
Kater, J. M. 1929. Morphology and division of Chlamydomonas with reference
to the phylogeny of the flagellate neuro-motor system. Univ. Calif. Publ.
Zool., 33: 125-168; Pls. 11-16; Figs. 1-7.
Krerr, A. M. 1926. A preserving fluid for green plants. Science, 64(n.s.):
331-332. 1927. A new species of Aphanocapsa. Rhodora, 29: 39-41.
Kersster, K. von. 1911. Untersuchungen iiber die Periodizitit des Phyto-
planktons des Leopoldsteiner-Sees in Steiermark, in Verbindung mit einer
eingehenderen limnologischen Erforschung dieses Seebeckens. Arch. f. Hy-
drobiol. u. Planktonk., 6: 480-485.
Kemmerer, G., Bovarp, J. F., and Boorman, W. R. 1924. Northwestern lakes
of the United States. Bull. U. S. Bur. Fish., 39: 51-140.
Kent, S. 1880-1882. (See Seville-Kent, W.)
Krener, W. 1944. Notes on distribution and bio-ecology of Characeae in Ne-
braska. Butler Univ. Studies Bot., 6: 131-148.
Kinpte, E. M. 1915. Limestone solution on the bottom of Lake Ontario. Amer.
Jour. Sci., 189: 651-656; Figs. 1-3.
Kincuner, O. 1878. Algen. In F. Cohn, Kryptogamen-Flora von Schlesien
Breslau. 1900. Schizophyceae. In A. Engler and K. Prantl, Die Natiirlichen
Pflanzenfamilien. 1 Teil, Abt. la: 45-92. Leipzig.
KissELEw, J. A. 1927. Zur Kenntnis der Algen des Aralsees. Bul. Bur. Appl
Ichth., 5: 274-305. 1931. Zur Morphologie einiger neuer und seltener
Vertreter des pflanzlichen Microplanktons. Arch. f. Protist., 73: 235-250.
Kyettman, F. R. 1898. Zur Organographie und Systematik der Aegagropilen.
Nova Acta Reg. Soc. Sc. Upsala, 17(Ser. 8): No. 7: 1-26.
Kiepann, H. 1892. Chaetosphaeridium Pringsheimii, novum genus et nova
species algarum chlorophycearum aquae dulcis. Pringsh. Jahrb. f. Wiss. Bot.,
94: 268-282: Pl. 4. 1893. Zur Kritik einiger Algengattungen. Ibid. 25:
278-321; Pl. 14. 1895. Gasvacuolen, ein Bestandtheil der Zellen der wasser-
bliithebildenden Phycochromaceen. Flora, 80: 241-282; Pl. 4. 1896. Ueber
wasserbliithebildende Algen, insbesondere des Pléner Seengebiets, und iiber
das Vorkommen von Gasvacuolen bei den Phycochromaceen. Forsch. Biol.
Stat. z. Plén, 4: 189-206. 1899. Die Befruchtung von Sphaeroplea annulina
Ag. Festschr. f. Schwendener, 1899: 81-103; Pl. 5.
KLEBAnN, H., and LemMEerMaANN, E. 1895. Vorarbeiten zu einer Flora des
Pléner Seengebietes. I. Forsch. Biol. Stat. z. Plon, 3: 1-17.
Kress, G. 1881. Beitriage zur Kenntniss niederer Algenformen. Bot. Zeit., 39:
249-957, 265-272, 281-290, 297-308, 313-319, 329-336; Pls. 3,4. 1883.
Ueber die Organisation einiger Flagellatengruppen und ihre Beziehungen zu
Algen und Infusorien. Untersuch. a d. Bot. Inst. z. Tiibingen, 1: 233-862;
[ 633 ]
Pls. 2, 3. 1892. Zur Physiologie der Fortpflanzung von Vaucheria sessilis.
Ver. d. Naturf. Ges. z. Basel, 10( Heft 1): 45-72. 1893. Flagellatenstudien.
L-Il. Zeit. Wiss. Zool., 55: 265-351, 353-445; Pls. 17, 18. 1896. Die Bedin-
gungen der Fortpflanzung bei einigen Algen und Pilzen. Jena. 1912. Ueber
Flagellaten- und Algen- ahnliche Peridineen. Ver. Naturh. med. Vereins
Heidelberg, 11(Heft 4): 367-451; Pl. 10; Figs. 1-15. 1928. Die Bedin-
gungen der Fortpflanzung bei einigen Algen und Pilzen. Jena.
KiercuER, J. 1896. Ueber zwei Wasserformen von Stichococcus. Flora, 82:
pei . D. 1929. Notes on the life history of Tetraspora gelatinosa (Vauch. )
Desv. Arch. f. Protist., 66: 290-296; PI. 8.
Koro, C. A. 1896. A report upon the Protozoa observed in Lake Michigan
and the inland lakes in the neighborhood of Charlevoix, during the sum-
mer of 1894. Appendix II. In: Michigan Fish Comm. Bull., 6: 3-93.
Korom, C. A., and MicHENER, J. R. 1911. New genera and species of Dino-
flagellates. Bull. Mus. Comp. Zool. (Harvard College), 54: 267-302.
Korow, C. A., and Swezy, Oxive. 1921. The free-living or unarmored Dino-
flagellata. Mem. Univ. Calif., 5: 1-562; Pls. 1-12; Figs. A-VV.
Kotxwitz, R., and Kriecer, W. 1941. Zygnemales. In L. Rabenhorst, Krypto-
gamen-Flora von Deutschland, Oesterreich und der Schweiz. 13, Abt. 2,
Lief. 1/2. Leipzig.
Korrre, Fritz. 1924. Die Schlammflora der ostholsteinischen Seen und des
Bodensees. Arch. f. Hydrobiol., 14: 619-719.
Korscuikov, A. A. 1917. Contribution a l’étude des algues de la Russie. Trav.
Stat. Biol. Borodinskaja, 4: 219-267; Pl. 2. 1923. Zur Morphologie des
geschlechtlichen Prozesses bei den Volvocales. (Russian with German sum-
mary.) Arch. Russ. Protist. 2: 179-194. 1924. Zur Morphologie und Syste-
matik der Volvocales. (Russian with German summary.) Ibid., 3: 45-56;
Pl. 2. 1924a. Protistologische Beobachtungen. (Russian with German sum-
mary.) Ibid., 3: 57-74. 1925. Beitrage zur Morphologie und Systematik der
Volvocales. I, (Russian with German summary.) Ibid., 4: 153-197; Pls. 7-9.
1925a. Contribution 4 étude des algues de la Russie. Rech. algol. aux
environs de la station Biol. Borodinskaja pendant ]’été 1925. 1927. On the
validity of the genus Schizomeris Kiitz. (Russian with English summary. )
Arch. Russ. Protist., 6: 71-82; Pls. 5,6. 1928. On two new Spondylomor-
aceae: Pascheriella tetras n. gen. et sp. and Chlamydobotrys squarrosa n. sp.
Arch. f. Protist., 61: 233-238; Pl. 9; Figs. 1-5. 1928a. Notes on some new
flagellates. (Russian and English.) Ibid., 7: 151-158. 19387. On the sexual
reproduction (odgamy) in the Micractineae. Kharkov A. Gorky State Univ.
Book No. 10( 1937): 109-126, 1941. On some new or little known flagellates.
Arch, f. Protist., 95: 22-44,
Korscuixov, A. A., and Anacuin, I. K. 1928. [Contribution to the study of the
validity of Chlamydobotrys gracilis Korsch.]. (Russian with English sum-
mary.) Arch. Russ. Protist., 7: 145-150.
KossinsxajA, C. 1940. Die Algen des Neva Beckens. Akad. nauk S.S.R.R.,
Leningrad. Bot. Inst. Trudy, Ser. 2, Plantae Crypt. (Acta Inst. Bot. Acad.
[ 634 |
Sci. URSS), 4(1938): 83-106. 1940a. [Algae from the environments of
Jukki]. (Russian with English summary.) Ibid., 4(1938): 107-130.
Kozminsk1, Z. 1938. Amount and distribution of the chlorophyll in some lakes
of northeastern Wisconsin. Trans. Wis. Acad. Sci., Arts and Letters, 31:
411-438.
Kriecer, W. 1932. Untersuchungen iiber Plankton-Chrysomonaden. Die Gat-
tungen Mallomonas und Dinobryon in monographischer Bearbeitung. Bot.
Arch., 29: 257-329.
Krocu, Aucust. 1931. Dissolved substances as food of aquatic organisms.
Biol. Rev. and Biol. Proc. Cambridge Phil. Soc., 6: 412-442.
Kurun, J. 1878. Ueber eine neue parasitische Alge, Phyllosiphon Arisari. Sitz.
Natur. Ges. Halle, 1878: 24-26.
Kueune, Paut E. 1941 The phytoplankton of southern and central Saskatche-
wan. Part II. Can. Jour. Res., 19 (Sec. C): 318-322; Figs. 1-3.
Kvuerzine, F. T. 1833. Algologische Mittheilungen. I. Ueber Gloionema Agh.
II. Ueber eine neue Gattung der Confervaceen. Flora, 16: 513-528. 1833a.
Beitrag zur Kenntniss iiber die Entstehung und Metamorphose der niedern
vegetabilischen Organismen, etc. Linnaea, 8: 335-382. 1833b. Synopsis
Diatomacearum oder Versuch einer systematischen Zusammenstellung der
Diatomeen. Ibid., 8: 529-620. 1833-1835. Algarum dulcis germanicarum.
Dec. I-XVI.-Halis Saxorum. 1835. Description de quelques nouvelles
espéces de Chara. Ann. Sci. Nat. Bot., 3(Sér. 2): 64. 1839. Ueber ein neues
Botrydium. Nova Acta Acad. Caes. Leop.-Carol., 19: 385. 1843.+ Phycologia
generalis, oder Anatomie, Physiologie und Systemkunde der Tange. 458 pp.;
Pls. 1-80. Leipzig. 1843a. Ueber die Systematische Eintheilung der Algen.
Linnaea, 17: 75-107. 1845. Phycologia germanica, d. i. Deutschlands Algen
in biindigen Beschreibungen. 340 pp. Nordhausen. 1847. Diagnosen und
Bemerkungen zu neuen oder kritischen Algen. Bot. Zeit., 5: 164-167. 1846—
1871. Tabulae phycologicae oder Abbildungen der Tange. I-XIX; Pls.
1-1900. Nordhausen. 1849. Species algarum. 922 pp. Leipzig.
Kurreratu, H. 1913. Contribution 4 la physiologie d’une Protococcacée nou-
velle Chlorella luteo-viridis Chodat, nov. spec. var. lutescens Chodat, nov.
var. Rec. Inst. Léo Errera, 9: 114-319; Figs. 1-28. 1914-1915. Contribu-
tions 4 la flore du Luxembourg meridional. II. Chlorophycées (exclus.
Desmidiacées), Flagellates et Cyanophycées. Ann. Biol. Lacustre, 7: 231-
271.
Kurssanow, L. J., and SCHEMAKHANOVA, N. M. 1927. Sur la succession des
phases nucléaire chez les algues vertes. I. Le cycle de développement du
Chlorochytrium Lemnae Cohn. Arch. Russ. Protist., 6: 131-146; Pls. 9, 10;
Figs. 1, 2.
ae H. 1912. Studien iiber die schwedischen Arten der Gattungen Batracho-
spermum Roth und Sirodotia nov. gen. Nova Acta. Reg. Soc. Sci. Upsala,
3(Ser. 4), No. 3: 1-40. 1917. Ueber die Entwicklungsgeschichte von
Batrachospermum moniliforme. Ber. d. Deutsch. Bot. Ges., 35: 155-170.
Lackey, JAMEs B. 1936. Some fresh water protozoa with blue chromatophores.
Biol. Bull., 71: 492-497. 1939. Notes on plankton flagellates from the Scioto
River. Lloydia, 2: 128-143. 1940. Limitations of Euglenidae as polluted
water indicators. U. S. Publ. Health Rep., 55(No. 7): 268-280; Figs. 1-6.
1944.* Quality and quantity of plankton in the south end of Lake Michigan
in 1942. Jour. Amer. Water Works Assoc., 36: 669-674; Figs. 1-7.
LacrrHem, G. 1882. Bidrag till kannedomen om Stockholmstraktens Pedia-
stéer, Protococcacéer och Palmellacéer. Oefv. Kongl. Sv. Vet.-Akad. Fér-
handl., 39(No. 2): 47-81; Pls. 2,3. 1883. Bidrag till Sveriges algflora. Ibid.,
[ 635 ]
40(No. 2): 37-78; Pl. 1. 1884. Ueber Phaeothamnion, eine neue Gattung un-
ter den Siisswasseralgen. Bih. Kongl. Sv. Vet.-Akad. Handl., 9( No. 19): 3-14;
1 pl. 1886. Algologiska bidrag. I. Contributions algologiques a la flora de la
Suéde. Bot. Notiser, 1886: 44-50. 1887. Note sur /Uronema, nouveau genre
des algues d’eau douce de l’ordre des Chlorozoosporacées. Malpighia, 1: 517—
523; Pl. 12. 1887a. Zur Entwickelungsgeschichte einiger Confervacéen. Ber.
d. Deutsch. Bot. Ges., 5: 409-417. 1887b. Ueber einige Algen aus Cuba,
Jamaica und Puerto-Rico. Bot. Notiser, 1887: 193-199. 1888. Sopra alcune
alghe d’acqua dolce nuovo o rimarchevoli. Notarisia, 1888: 590-595. 1889.
Studien iiber die Gattung Conferva und Microspora. Flora, 72: 179-210; Pls.
5, 6. 1890. Contribuciones a la flora algologica del Ecuador. I-II. Anal. Univ.
Central de Quito, Ecuador, 4(1890-1891): 79-88. 1892. Die Schneeflora
des Pichincha. Ber. d. Deutsch. Bot. Ges., 10: 517-534; Pl. 28. 1893.
Chlorophyceen aus Abessinien und Kordofan. Nuova Notarisia, 4: 153-160.
1895. Studien wber die arktische Cryptogamen. 1. Ueber die Entwickelung
von Tetraédron Kiitz. und Euastropsis Lagerh., eine neue Gattung der
Hydrodictyaceen. Troms6 Mus. Aarschefter, 17(1894): 1-24. 1900. Vege-
tabilisches Siisswasser-Plankton aus der Bareninseln (Beeren-Eiland). Bih.
Kongl. Sv. Vet.-Akad. Handl., 26, Afd. 3, No. 11: 1-25.
Lacuer, Karu. 1940. A turtle loss? Amer. Wildlife, 29: 41-44. 1943. Food
habits and economic relations of the turtles of Michigan with special ref-
erence to fish management. Amer. Mid]. Nat., 29: 257-312.
Lampert, F. D. 1909. Two new species of Characium. Rhodora, 11: 65-74.
Lapua, I. A. 1850.* Plants of Wisconsin. Proc. Amer. Assoc. Adv. Sci., 1849:
19-59.
Larsen, E. 1904. The fresh water algae of East Greenland. Medd. om Gron-
land, 30(B): 75-100.
LauTERBORN, R. 1896. Diagnosen neuer Protozoen aus dem Gebiete des
Oberrheins. Zool. Anz., 19: 14-18. 1899. Protozoenstudien. Flagellaten aus
dem Gebiete des Oberrheins. Zeit. Wiss. Zool., 65: 365-391; Pls. 17, 18.
1913. Zur Kenntnis einiger sapropelischer Schizomyceten. Allg. Bot. Zeitschr.,
19: 97-100. 1913a. Siisswasserfauna. Handwort. Naturwiss., 9: 861-920.
1914-1917. Die Sapropelische Lebewelt. Ver. Natur. mediz. Ver. Heidel-
berg, 13: 395-481.
Leake, Dorotuy V. 1938. Preliminary note on the production of motile cells
in Basicladia. Proc. Okla. Acad. Sci., 19: 109-110.
Lesour, Marie V. 1925. The dinoflagellates of northern seas. Plymouth, Eng.
Lerevre, M. 1925. Contribution a la flore des algues d’eau douce du nord de
la France. Bull. Soc. Bot. France, 72 (Vol. 1, Ser. 5): 689-699. 1932.
Monographie des espéces d’eau douce du genre Peridinium. Arch. d. Bot.,
2(1928, Mém. 5): 1-210. 1932a. Sur la structure de la membrane des Eug-
lénes du groupe, Spirogyra. Comp. Rend. Acad. Sci. Paris, 195: 1308-1309.
LEFEVRE, M., and BourreLuy, P. 1939. Sur la stabilité de ornamentation chez
les espéces du genre Pediastrum Meyen. Comp. Rend. Acad. Sci. Paris,
208: 368-370.
LEMMERMANN, E. 1895. Verzeichnis der in der Umgegend von Ploen ges-
ammelten Algen. Forsch. Biol. Stat. z. Plon, 3: 18-67. 1896. Zweiter Beitrag
zur Algenflora des Pléner Seengebietes. Ibid., 4: 134-188. 1896a. Zur
Algenflora des Riesengebirges. Ibid., 4: 88-133. 1897. Die Planktonalgen des
Miiggelsees bei Berlin. II. Zeit. f. Fisch., 1897: 177-188. 1897a. Resultate
einer biologischen Untersuchungen von Forellenteichen. Forsch. Biol. Stat.
z. Plon, 5: 67-114. 1898. Der grosse Waterneverstorfer Binnensee. Eine
biologische Studie. Ibid., 6: 166-204. 1898a. Beitrag zur Algenflora von
[ 636 ]
Schlesien. Abh. Natur. Ver. Bremen, 14(1897): 241-263; Pl. 1. 1898b.
Algologische Beitrage. IV—V. Ibid., 14: 501-512; Pl. 5. 1898c. Beitrage
zur Kenntniss der Planktonalgen. I. Golenkinia Chodat, Richteriella Lemm.,
Franceia nov. gen., Phythelios Frenzel, Lagerheimia Chodat, Chodatella
nov. gen., Schroederia nov. gen. Hedwigia, 37: 303-312; Pl. 10. 1898d.
Beitrage zur Kenntniss der Planktonalgen. II. Beschreibung neuer Formen.
Bot. Centralbl., 76: 150-156. 1899.t Das Genus Ophiocytium Naegeli.
Hedwigia, 38: 20-38; Pls. 3,4; Figs. 15-18. 1899a. Das Phytoplankton
sachsischer Teiche. Forsch. Biol. Stat. z. Plon, 7: 96-140; Pls. 1,2. 1900.
Ergebnisse einer Reise nach dem Pacific (H. Schauinsland 1896-1897 )
Planktonalgen. Abh. Natur. Ver. Bremen, 16(1899): 313-398. 1900a. Beit-
rige zur Kenntniss der Planktonalgen. III. Neue Schwebalgen aus der
umgegend von Berlin. Ber. d. Deutsch. Bot. Ges., 18: 24-32. 1900b. Beitrage
zur Kenntniss der Planktonalgen. IV. Die Coloniebildung von Richteriella
botryoides (Schmidle) Lemm. Ibid., 18: 90-91; Pl. 3. 1900c. Beitrage zur
Kenntniss der Planktonalgen. VIII. Peridiniales aquae dulcis et submarinae,
Hedwigia, 39: [115-121]. 1900d. Beitrage zur Kenntniss der Planktonalgen.
VI. Das Phytoplankton brackischer Gewasser Ber.d.Deutsch.Bot.Ges.,18:90—94.
IX. Lagerheimia Marssonii nov. spec., Centratractus belonophora (Schmidle )
nov. gen. et sp., Synedra limnetica nov. spec., Marssoniella elegans nov. gen.
et sp. Ber. d. Deutsch. Bot. Ges., 18: 272-275. 1900e. Beitrage zur Kennt-
niss der Planktonalgen. XI. Die Gattung Dinobryon Ehrenb. Ibid., 18: 500-
524; Pls. 18,19. 1901. Beitriége zur Kenntniss der Planktonalgen. XII. Noti-
zen iiber einige Schwebalgen. Ibid., 19: 85-92. 1901la. Beitrage zur Kennt-
niss der Planktonalgen. XIII. Das Phytoplankton des Ryck und des Greifs-
walder Boddens. Ibid., 19: 92-95. 1901b. Beitrage zur Kenntniss der
Planktonalgen. XIV. Neue Flagellaten aus Italien. Ibid., 19: 340-348. 1901c.
Zur Kenntnis der Algenflora des Saaler Boddens. Forsch. Biol. Stat. z. Plon,
8: 74-85. 1901d. Algenflora eines Moortiimpels bei Plén. Ibid., 8: 64-73.
1902. Bericht der Commission fiir die Flora von Deutschland. VI. Algen
des Siisswassers. Ber. d. Deutsch. Bot. Ges., 20: [243-253, 257-263]. 1903.
Beitrage zur Kenntnis der Planktonalgen. XV. Das Phytoplankton einiger
Pléner Seen. Forsch. Biol. Stat. z. Plon, 10: 116-176. 1903a. Brandenbur-
gische Algen. Hedwigia, 42: [168-169]. 1903b. Brandenburgische Algen.
II. Das Phytoplankton des Miiggelsees und einer benachbarter Gewasser.
Zeit. f. Fisch., 11(Heft 2): 73-123. 1903c. Beitriége zur Kenntnis der
Planktonalgen. XVI. Phytoplankton voh Sandhem (Schweden). Bot. Notiser,
1903: 65-69. 1903d. Das Phytoplankton des Meeres. II. Beitrag. Abh.
Natur. Ver. Bremen, 17: 341-418. 1904. Das Plankton schwedischer Gewas-
ser. Arkiv f. Bot., 2, No. 2(1903+1904): 1-209; Pls. 1,2. 1904a. Beitrage
zur Kenntnis der Planktonalgen. XIX. Das Phytoplankton der Ausgrabenseen
bei Plén. Forsch. Biol. Stat. z. Plon, 11: 289-311; Figs. 1-17. 1904b.
Beitrige zur Kenntnis der Planktonalgen. XVIII. Ueber die Entstehung
neuer Planktonformen. Ber. d. Deutsch. Bot. Ges., 22: 17-22. 1905. Branden-
burgishe Algen. III. Neue Formen. Forsch. Biol. Stat. z. Plon, 12: 145-153.
1905a. Beitrage zur Kenntnis der Planktonalgen. XX. Phytoplankton aus
Schlesien. Ibid., 12: 154-163. 1905b. Beitrige zur Kenntnis der Planktonalgen.
XXI. Das Phytoplankton siichsischer Teiche. Zweiter Beitrag. Ibid., 12: 164—
168. 1905c. Die Algenflora der Sandwich-Inseln. Ergebnisse einer Reise nach
dem Pacific. H. Shauinsland 1896/97. Engler. Bot. Jahrb., 34: 607-663;
Pls. 7, 8. 1906. Ueber die von Herrn Dr. Walter Volz auf seiner Weltreise
,gesammelten Siisswasseralgen. Abh. Natur. Ver. Bremen, 18 (1905-1906 ):
143-174; Pl. 11. 1906a. Das Phytoplankton des Meeres. Beih Bot. Centralbl.,
[ 637 ]
19(Heft 2): 1-74. 1906b. Beitrage zur Kenntnis der Planktonalgen. Ber. d.
Deutsch. Bot. Ges., 24: 535-538. 1906c. Uber das Vorkommen von Siisswas-
serformen in Phytoplankton des Meeres. Arch. f. Hydrobiol. u. Planktonk., 1:
409-427. 1907. Das Plankton der Weser bei Bremen. Ibid., 2: 393-447. 1907a.
Das plankton des Jang-tse-Kiang (China). Ibid., 2: 534-544. 1907b. Bran-
denburgische Algen. IV. Gonyaulax palustris, eine neue Siisswasser-Peridinee.
Beih. Bot. Centralbl., 21: 296-300. 1907-1910.t Kryptogamenflora der
Mark Brandenburg. Algen. I. Leipzig. 1908. Algologische Beitrage. VI.
Algen aus der Biviera von Lentini (Sizilien). VII. Ueber Scheidenbildung
bei Oscillatoria Agardhii Gomont. VII. Zur Algenflora des Anapo. IX. Neue
Schizophyceen. X. Die Micrasterias-Formen des Kénigreichs Sachsen. XI.
Oedogonium cardiacum var. minor Lemm. nov. var. Arch. f. Hydrobiol. u.
Planktonk., 4: 165-192; Pl. 5. 1908a. Beitrage zur Kenntnis der Plankton-
algen. XXIII. Das Phytoplankton des Lago di Varano und des Lago di
Monate (Italien). Ibid., 3: 349-886; Figs. 1-25. 1908b. Beitrage zur
Kenntnis der Planktonalgen. XXIV. Plankton aus Schlesien. 2 Beitrag. Ibid.,
3: 386-404; Figs. 26-35. 1908c. Beitriige zur Kenntnis der Planktonalgen.
XXV. Die Algen Stralsunder Rohwassers. Ibid., 3: 404-410; Figs. 86-40.
1908d. Das Phytoplankton des Menam. Hedwigia, 48: 126-189. 1910
(1907-1910). Kryptogamenflora der Mark Brandenburg. Algen. I. Leipzig.
1913.+ Euglenineae. Flagellatae II. In A. Pascher, Die Siisswasserflora
Deutschlands, Oesterreichs und der Schweiz. Heft 2. Flagellatae 2: 115-174;
Figs. 181-377. Jena. 1914. Algologische Beitrige. XII. Die Gattung Chara-
ciopsis Borzi. Abh. Natur. Ver. Bremen, 23: 249-261; Figs. 1-14. 1915.+
Tetrasporales. In A. Pascher, Die Siisswasserflora Deutschlands. Oesterreichs
und der Schweiz. Heft 5. Chlorophyceae 2: 21-51; Figs. 1-33. Jena.
Lreonnarpi, H. von. 1863. Die boéhmischen Characeen. Lotos, 18: 55-80,
110-111.
Levanper, K. M. 1900. Der Kenntniss der Lebens in den stehenden Kleinige-
wissern auf den Skireninseln. Acta Soc. Fauna et Flora Fenn., 18(No. 6):
1-107. 1901. Beitrage zur Fauna und Algenflora der sussen Gewasser an
der Murmankiiste. I[bid., 20( No. 8): 1-35.
LEvERETT, FRANK. 1911. Surface geology of the Northern Peninsula of Mich-
igan. Mich. Geol. and Biol. Surv. Publ. No. 5: 1-86. 1917. Surface geology
and agricultural conditions of Michigan. Ibid., No. 25(Geol. Ser. 21): 1-223.
Lewss, I. F. 1913.* Chlorochromonas minuta, a new flagellate from Wisconsin.
Arch. f. Protist., 32: 249-256; Pl. 12. 1925. A new conjugate from Woods
Hole. Amer. Jour. Bot., 12: 351-357; Pls. 36, 37.
Lewis, I. F., Zmkie, C., and Parricx, Ruru. 1933. Algae of Charlottesville
and vicinity. Jour. Elisha Mitchell Sci. Soc., 48: 207-222.
Ley, S. H. 1947. Heleoplanktonic algae of North Kwangtung. Bot. Bull. Acad.
Sinica, 1: 270-282; Figs. la—lh.
Li, L. C. 1933. New species and varieties of freshwater algae from China.
Ohio Jour. Sci., 33: 151-154.
LirpMann, F. 1841. Bemiirkninger og Tillag til den danske Algeflora. Kroyers
Tidsk., 1841. Kjobenhavn. 1841a. Algologisk Bidrag. Kjobbenhavn. (Not seen.)
Littey, Gene. 1903. Nitella batrachosperma in Minnesota. Minn. Bot. Studies,
3: 79-82; Pl. 18.
Liuicx, Lois C. 1935.,A new species of Spirulina. Amer. Midl. Nat., 16:
210-211; Figs. 1A-ID.
LinpEMAN, RayMonp L. 1941. Seasonal food cycle dynamics in a senescent
lake. Amer. Midl. Nat., 26: 636-673. 1942. The trophic-dynamic aspect of
ecology. Ecology, 23: 399-418.
[ 638 |
LINDEMANN, E. 1925. Ueber finnische Peridineen. Arch. f. Hydrobiol. u. Plank-
tonk., 15: 1-4. 1928. Vorlaufige Mitteilung. Arch. f. Protist., 63: 259-260.
1928a. Peridineae (Dinoflagellatae). In A. Engler and K. Prantl, Die
Natiirlichen Pflanzenfamilien. 2: 1-104; Figs. 1-92. 2nd. ed. Leipzig.
Linx, H. F. 1809. Nova plantarum genera e classe Lichenum, Algarum, Fun-
gorum. Schrader’s Neue Journal f. die Botanik, 3(Stiick 1): 1-19. 1820.
Epistola de Algis aquaticis in genera disponendis. In C. G. H. Nees von
Esenbeck, Horae physicae berolinenses, pp. 1-8. 1833. Handbuch zur
Erkennung der nutzbarsten und am haufigsten vorkommenden Gewachse,
Dritter Teil. Berlin.
LinnaEus, Cart von. 1737. Genera plantarum. Leiden. 1753. Species plant-
arum. Stockholm., 1754. Genera plantarum. 5th ed. 1758. Systema naturae.
Regnum animale. Vol. I. 10th ed. Leipzig.
Losi, A. I. 1915. Catalogue des algues d’eau douce recueillies au Caucase
ar A. A. Elenkin et V. P. Savicz dans la région Czernomorsk pendant
Pété 1912. Bull. Jard. Imp. Bot. Pierre le Grand, 15(No, 1): 23-47.
Louman, H. 1911. Ueber das Nannoplankton und die Zentrifugierung kleinster
Wasserproben zur Gewinnung desselben in lebenden Zustande. Inter. Rev.
Ges. Hydrobiol. u. Hydrogr., 4(Pt. 1/2): 1-38.
LoisELEUR-DEsLoNccHamMps, J. L. A. 1810. Notice sur les plantes a ajouter 3
la flore de France, pp. 135-139. Paris.
Lowe, C. W. 1927. Some freshwater algae of southern Quebec. Trans. Roy.
Soc. Canada, 5: 291-316.
Lucxs, R. 1907. Zur Kenntnis der westpreussischen Pediastrumarten. Jahrb. d.
Westpr. Lehrevereins f. Naturk., 1906-1907: 31-49.
Lunp, J. W. G. 1947. Observations on soil algae. III. Species of Chlamydomo-
nas Ehr. in relation to variability within the genus. New Phytol., 46(2):
185-194; Figs. 1-3.
Lyman, F. E. 1936.* Plankton of inland waters. Mich. State College Agric.
Appl. Sci. Eng., Exper. Sta., Bull. No. 66: 20-24.
LyncByeE, H. Cu. 1819. Tentamen Hydrophytologiae Danicae. Kjobenhavn.
MacmiLan, Conway. 1894. Sphaeroplea annulina in Minnesota. Bot. Gaz.,
19: 246.
Macnus, P. 1883. Das Auftreten von Aphanizomenon flos-aquae (L.) Ralfs
in Eise bei Berlin. Ber. d. Deutsch. Bot. Ges., 1: 129-132.
Mainx, F. 1926. Einige neue Vertreter der Gattung Euglena Ehr. Arch. f.
Protist., 54: 150-182. 1928. Beitrige zur Morphologie und Physiologie der
Eugleninen. I. Ibid., 60: 305-414; Pl. 10.
Mancin, L. 1911. Modifications de la curiasse chez quelques Péridiniens.
Inter. Rev. Ges. f. Hydrobiol. u. Hydrogr., 4: 44-54; Plsaeieo:
Mannine, W. M., and Jupay, C. 1941. The chlorophyll content and product-
ivity of some lakes in northeastern Wisconsin. Trans. Wis. Acad. Sci., Arts
and Letters, 33: 363-393.
Manninc, W. M., Jupay, C., and Woir, MICHAEL. 1938. Photosynthesis of
aquatic plants at different depths in Trout Lake, Wisconsin. Trans. Wis.
Acad. Sci., Arts and Letters, 31: 377-410.
Marsu, C. D: 1903.* The plankton of Lake Winnebago and Green Lake. Bull.
Wis. Geol. and Nat. Hist. Surv., 12, Sci. Ser., No. 3: 1-94.
MarsHat, F. T., and Hacue, S. M. 1938. Basicladia in Illinois. Trans. Il.
Acad. Sci., 31: 111-112.
Martwus, C. F. P. von. 1817. Flora cryptogamica Erlangensis. Nuremberg.
MaskELL, W. M. 1887. On the fresh-water infusoria of the Wellington district.
Trans. N. Z. Inst., 20: 3-19.
[ 639 ]
Masser, G. 1891. Life-history of a stipitate freshwater alga. Jour. Linn. Soc.
Bot., 27: 457-462.
Menecuint, G. 1837. Conspectus algologiae euganeae. 37 pp. Patavia. 1840.
Synopsis Desmidiacearum hucusque cognitarum. Linnaea, 14: 201-240.
1842. Monographia Nostochinearum italicarum. Aug. Taurinorum. (Not
seen. )
MessikoMMER, Ep. 1927. Biologische Studien im Torfmoor von Robenhausen
unter besondere Beriicksichtigung der Algenvegetation. Mitt. Bot. Mus. Univ.
Zurich, 122: 1-171.
Meunier, A. 1919. Microplankton de la Mer Flamande. Part II. Les Péri-
diniens. Mém. Mus. Roy. Hist. Nat. Belgique, 8(No 1): 1-116.
Meyen, F. J. F. 1829. Beobachtungen iiber einige niedere Algenformen. Nova
Acta Acad. Caes. Leop.-Carol., 14: 768-778. 1838. Neues System Pflanzen-
Physiologie. Bd. 2. Berlin. 1839. Jahresberichte iiber die Resultate der
Arbeiten im Felde der physiologischen Botanik von dem Jahre 1838. Arch.
f. Naturg., 2: 1-153.
Meyer, A. 1895. Ueber den Bau von Volvox aureus Ehrenb. und Volvox
globator Ehrenb. Bot. Centralbl., 63: 225-233; Figs. 14. 1896. Die Plas-
maverbindungen und die Membranen von Volvox globator, aurens und
tertius mit Riicksicht auf die thierischen Zellen. Bot. Zeit., 54: 187-217;
Pl. 8; Figs. 1-7.
Meyer, C. I. 1922. Algae nonnullae novae baicalenses. Not. Syst. Inst. Crypt.
Horti Bot. Petropol., 1(No. 1): 13-15. 1930. Einige neue Algenformen des
Baikalsees. Arch. f. Protist., 72: 158-172.
Meyer, K. I. (See Meyer, C. I.)
Micuta, W. 1907. In Thome, Kryptogamen-Flora Deutschland, Deutsch-
Oesterreich und der Schweiz, 6, Kryptogamen 2, Algen 1. Gera.
Miter, V. V. 1923. Zur Systematik der Gattung Anabaena Bory. Arch. Russ.
Protist., 2: 116-126; Figs. 1-5.
Moestvus, M. 1888. Beitrag zur Kenntniss der Algengattung Chaetopeltis Ber-
thold. Ber. d. Deutsch. Bot. Ges., 6: 242-248; Pl. 12. 1888a. Ueber einige
in Portorico gesammelte Siisswasser- und Luft-Algen. Hedwigia, 27: 221-
249. 1889. Bearbeitung der von H. Schenck in Brasilien gesammelten Algen.
Ibid., 28: 309-847. 1892. Australische Siisswasseralgen. Flora, 75: 421-450.
1894. Australische Siisswasseralgen. II. Abh. Senck. Natur. Ges. Frankfurt
A. M., 18: 309-350. 1895. Beitrag zur Kenntniss der Algengattung Pitho-
phora. Ber. d. Deutsch. Bot. Ges., 18: 356-361.
Moewvus, Franz. 1935. Ueber einige Volvocalen aus dem Geogenfelder Moor
(Erzgebirge). Sitz. Abh. Naturwis. Ges. Isis in Dresden, 1933-1934: 45-51;
Figs. 1-6. 1936. Neue Volvocalen aus der Umgebung von Coimbra ( Portu-
gal). Bol. Soc. Broteriana, 10: 1-14; Figs. 1-6 (reprint).
Mouiscu, H. 1896. Die Ernéhrung der Algen (Siisswasseralgen II. Abhand-
lung). Sitz. Kais. Akad. Wiss. in Wien, Math.-Nat. KI., 105(Abt. 1):
633-648.
Moore, G. T. 1897. Notes on Uroglena americana. Bot. Gaz., 23: 105-112;
Pl. 10. 1900. New or little known unicellular algae. I. (Chlorocystis Cohnii}.
Ibid., 30: 100-112. 1901. Ibid. II. (Eremosphaera viridis, Excéntrosphaera).
Ibid., 32: 309-325. 1917. Chlorochytrium gloeophilum Bohlin. Ann. Missouri
Bot. Gard., 4: 271-278; Pl. 18.
Moores, G. T., and Carrer, NEE. 1923. Algae from lakes in the north-
eastern part of North Dakota. Ann. Missouri Bot. Gard., 10: 393-422; Pl. 21.
Moore, G. T., and KetLermann, K. F. 1904. A method of destroying or
preventing the growth of algae and certain pathogenic bacteria in water
[| 640 |
supplies. U. S. Dept. Agric., Bur. Plant Indust., Bull. 64. Washington. 1905.
Copper as an algacide and disinfectant in water supplies. Ibid., Bull. 76.
Washington.
Morosowa-WopyanirzkajA, N. W. 1925. Dichomologischen Reihen als Grund-
lage zur Klassification der Gattung Pediastrum Meyen. Russkii Ark. Protot.,
4(No. 1/2): 5-81.
MorreN, Cu. 1830. Mémoire sur un végétal microscopique d’un nouveau
genre, proposé sous le nomme Microsoter, ou conservateur des petites choses.
Ann. Sci. Nat. Bot., 20(Sér. 1): 404-426. 1838. Recherches physiologiques
sur les hydrophytes de la Belgique. Premier Mémoire. Histoire d'un genre
nouveau de la tribu Confervées, nommé par lauteur, Aphanizomene.
Mém. Acad. Roy. Belgique, 11: 5-20 (in unnumbered memoirs in vol. )eal spk
Muetter, O. F. 1773. Vermium terrestrium et fluviatilium. Hauniae, Faber.
1776. Zoologiae Danicae prodromus, seu animalium Daniae et Norvegiae
indigenarum characteres, nomina et synonyma imprimis populorium. Havnia,
Hallogeriis. 1786. Animalicula infusoria, fluviatilia et marina. Hafniae et
Lipsiae.
wigan GrorcE. 1892-1895.* Calcareous pebbles formed by algae. Phycol.
Mem., Part II( No. 13): 74-77.
Nagcet, C. W. 1847. Die neuern Algensysteme und Versuch zur Begriindung
eines eignen Systems der Algen und Florideen. Zurich. 1849.+ Gattungen
einzelligen Algen, physiologische und systematische bearbeitet. 137 pp.;
Pls. 1-8. Zurich.
Namystowsk1, B. 1921. Studja Hydrobiologiczne. HII. Prace Koniisji Matew.-
Przyrod. Tow. Pizyinc. Nauk. w. Pozanaiu. Ser. B. 1, z. 1(1921). Poznan.
(Not seen. )
Naya . See El-Nayal.
NEEDHAM, J. G., and Luoyp, J. T. 1916. The life of inland waters. Ithaca, N. Y.
NEEDHAM, J. G., and NEEDHAM, P. R. 1938. A guide to the study of fresh-
water biology with special reference to aquatic insects and other inverte-
brate animals and phytoplankton. 4th ed. Ithaca, N. Y.
NEEL, J. K. 1948.* A limnological investigation of the psammon in Douglas
Lake, Michigan, with especial reference to shoal and shoreline dynamics.
Trans. Amer. Microsc. Soc., 67: 1-53.
Nicnots, G. E., and AcxLry, ALMa B. 1932.* The desmids of Michigan with
particular reference to the Douglas Lake region. Pap. Mich. Acad. Sci., Arts,
and Letters, 15( 1931): 113-140.
Nisuimura, M. 1923. The theory of the spherical thallus formation of Aega-
gropila Sauteri (Nees) Kuetz. Bot. Mag. Tokyo, 37: 62.
Norpstept, [C. F.] O. 1876. In C. F. O. Nordstedt & V. Wittrock. 1876. I
Desmidieae (Kiitz.) De Bar. Oef. Kongl. Sv. Vet-Akad. Forhandl., 33
(No. 6): 25-44. 1877. Bohuslans Oedogonieer. Ibid., 34( No. 4) 21-38. 1878.
De Algis aquae dulcis et de Characeis ex insulis sandvicencibus a Sv. Berggren
1875 reportatis. Minnesskr. Fys. Sallsk. Lund, 7: 1-24; Pls. 1,2. 1879.
Algologiska smisaker, II. Vaucheria-studier. 1879. Bot. Notiser, 1879: 177-
190. 1888. Freshwater algae collected by Dr. S. Berggren in New Zealand
and Australia. Bih. Kongl. Sv. Vet.-Akad. Handl., 22(No. 8): 1-98. 1891.
On the value of original specimens (translated from Botaniska Notiser,
1891: 76-82). Nuova Notarisia, 1891: 449-454.
Norpstept, C. F. O., and Wirrrocx, V. 1876. Desmidieae et Oedogonieae ab
O. Nordstedt in Italia et Tyrolia collectae, quas determinaverunt. Oef. Kongl.
Sv. Vet.-Akad. Foérhandl., 33(No. 6): 25-56; Pls. 12, 18.
Nowaxowsk1, L. 1877. Beitrag zur Kenntnis der Chytridiaceen. Beitr. Biol.
Pflanzen, 2( No. 1): 73-100.
[ 641 ]
Nycaarp, G. 1932. Contributions to our knowledge of the freshwater algae
and phytoplankton from the Transvaal. Trans. Roy. Soc. S. Africa, 20:
101-148. 1949. Hydrobiological studies on some Danish ponds and lakes.
Kongl. Danske Vid. Selsk. Biol. Skrift., 7( No. 1): 1-293; 126 figs.
OerstTeED, A. S. pE. 1842. Beretning om en Excursion til Trindelen, en alluvi-
aldannelse i Odensefjord. Kjobenhavn.
Onasui, H. 1926. Oedogonium nebraskensis (sic), sp. nov. Bot. Gaz., 82:
207-214; Figs. 1-20.
Otive, Epcar W. 1905.* Notes on the occurrence of Oscillatoria prolifica
(Greville) Gomont in the ice of Pine Lake, Waukesha County. Trans. Wis.
Acad. Sci., Arts and Letters, 15(Pt. 1): 124-134.
OLrManns, F. 1922.+ Morphologie und Biologie der Algen. Vol. 1: 1-459; Figs.
1-287; Vol. 2: 1-439; Figs. 288-612; Vol. 3: 1-558; Figs. 613-797. 2nd ed.
Jena.
Osorio TaraLy, B. F. 1941. Materiales para el estudio del microplankton del
Lago de Patzcuaro (México). I. General idades y fitoplankton. Anal. Escuela
Nac. Cien. Biol. (México), 2: 331-382.
OsTENFELD, C. H. 1907. Beitrage zur Kenntnis der Algenflora des Kosogol-
Beckens in der nordwestlichen Mongolei, mit spezieller Beriichsichtigung
des Phytoplanktons. Hedwigia, 46: 365-420. 1909. Notes on the phyto-
plankton of Victoria Nyanza, East Africa. Bull. Mus. Comp. Zool. (Harvard
College), 52(No. 10): 171-181.
OsTENFELD, C. H., and Nycaarp, G. 1925. On the phytoplankton of the Gatun
Lake, Panama Canal. Dansk Bot. Arch., 4: 1-16; Figs. 1-20.
Oye, P. van. 1924. Note sur Euglena acus Ehrenberg. Bull. Soc. Bot. Belgique,
56, Fasc. 2(1921-1923): 124-182.
Pauia, E. 1894. Ueber eine neue, pyrenoidlose Art und Gattung der Conju-
gaten. Ber. d. Deutsch. Bot. Ges., 12: 228-236; Pl. 18.
Patmer, C. Mervin. 1941. A study of Lemanea with notes on its distribution
in North America. Butler Univ. Studies, 5: 1-26; Figs. 1-4.
Parmer, T. C. 1905. Delaware valley forms of Trachelomonas. Proc. Acad.
Nat. Sci. Phila., 57: 665-675. 1925. Trachelomonas: New or notable species
and varieties. Ibid., 77: 15-22.
Papenruss, G. F. 1946. Proposed names for the phyla of algae. Bull. Torr.
Bot. Club, 73(3): 217-218.
Pascuer, A. 1909. Einige neue Chrysomonaden. Ber. d. Deutsch. Bot. Ges.,
27: 247-254. 1910.’ Neue Chrysomonaden aus den Gattungen Chrysococcus,
Chromulina, Uroglenopsis. Oesterr. Bot. Zeit., 60: 1-5. 1912. Eine farblose,
rhizopodiale Chrysomonade. Ber. d. Deutsch. Bot. Ges., 30: BP alee TAL 6.
1912a. Ueber Rhizopoden-und Palmellastadien bei Flagellaten (Chrysomona-
den), nebst einer Ubersicht iiber die braunen Flagellaten. Arch. f. Protist.,
25: 153-200; Pl. 9; Figs. 1-7. 1912b. Zur Kenntnis zweier Volvokalen.
Hedwigia, 52: 274-287. 1913.+ Chrysomonadineae, Cryptomonadineae. In
A. Pascher, Die Siisswasserflora Deutschlands, Oesterreichs und der Schweiz.
Heft 2. Flagellatae 2: 7-95; Figs. 1-150. Jena. 1913a. Die Heterokonten-
gattung Pseudotetraédron. Hedwigia, 53(1912): 1-5; Figs. 1-6. 1913b. Zur
Gliederung der Heterokonten. Ibid. 53(1912): 6-22. 1914. Ueber Symbiosen
von Spaltpilzen und Flagellaten mit Blaualgen. Ber. d. Deutsch. Bot. Ges.,
32: 339-352. 1914a. Ueber Flagellaten und Algen. Ibid., 32: 136-160. 1921.
Ueber die Ubereinstimmungen zwischen den Diatomeen, Heterokonten und
Chrysomonaden. Ibid., 39: 236-248; Figs. 1-6. 1925. Heterokontae, Phaeo-
phyta. In A. Pascher, Die Siisswasserflora Deutschlands, Oesterreichs und der
Schweiz. Heterokontae, Phaeophyta, Rhodophyta, Charophyta. Heft 11:
[ 642 J
1-118; Figs. 1-96. 1925a. Neue oder wenig bekannte Protisten. XV. Arch.
f. Protist., 50: 486-510. 1925b. Die braune Algenreiche der Chrysophyceen.
Ibid., 52: 489-564. 1927. Volvocales-Phytomonadinae. In A. Pascher, Die
Siisswasserflora Deutschlands, Oesterreichs und der Schweiz. Heft 4: 1-506;
Figs. 1-45. Jena. 1927a. Neue oder wenig bekannte Protisten. XX. Arch.
f. Protist., 58: 577-598. 1927b. Die braune Algenreiche aus der Ver-
wandtschaft der Dinoflagellaten (Dinophyceen ). Ibid., 58: 1-54; Figs. 1-38.
1930. Zur Kenntnis der heterokonten Algen. Ibid., 69: 401-454; Pl. 21; Figs.
1-45. 1930a. Berichtigung zum Aufsatze: Zur Kenntnis der heterokonten
Algen. Ibid., 69: 666. 1930b. Ein griiner Sphagnum-Epiphyt und seine
Beziehung zu freilebenden Verwandten (Desmatractum, Calyptobactron,
Bernardinella). Ibid., 69: 637-658. 1932. Einige neue oder Kritische Hetero-
konten. Ibid., 77(No. 2): 305-359. 1932a. Zur Kenntnis mariner Plankton-
algen. I. Meringosphaera und ihre Verwandten. Ibid., 77(No. 2): 195-218.
1932b. Ueber eine in ihrer Jurgend rhizopodial und animalisch lebende epi-
phytische Alge (Perone). Beih. Bot. Centralbl., 49( Abt. 1): 675-685; Figs.
1-7. 1937-1939. Heterokonten. In L. Rabenhorst, Kryptogamen-Flora von
Deutschland, Oesterreich und der Schweiz. XI: 1-1092; Figs. 1-912. Leipzig.
1940. Zur Kenntnis der Siisswassertetrasporalen I. Beih. Bot. Centralbl.,
60A: 185-156; Pl. 4; Figs. 1-22.
Pascuer, A., and LEMMERMANN. E. 1913. (See Pascher, 1913.)
Pascuer, A., and Scuitter, J. 1925. (See Pascher, 1925.)
Pavitiarp, J. 1923. A propos de la systématique des Péridiniens. Bull. Soc.
Bot. France, 70: 876-882.
PearsaLt, W. H. 1924. Phytoplankton and environment in the English lake
district. Rev. Algol., 1: 53-67.
Prestes, F. 1909. The life history of Sphaerella lacustris (Haematococcus
pluvialis) with especial reference to the nature and behaviour of the zoo-
spores. Centralbl. Bakt., 24: 18-22, 511-521.
Penarp, C. 1891. Les Péridiniacées du Lac Leman. Bull. Trav. Soc. Bot.
Genéve, 6: 1-63.
PenHALLow, D. P. 1896.* Note on calcareous algae from Michigan. Bot. Gaz.,
21; 215-217.
Pennak, Rosert W. 1939. The microscopic fauna of the sandy beaches. In
Problems of Lake Biology. Amer. Assoc. Adv. Sci., Publ. No. 10: 94-106.
Perty, M. 1849. Ueber verticale Verbreitung mikroskopischer Lebensformen.
Natur. Ges. in Bern Mitt., 1849: 17-45. 1852. Zur Kenntniss kleinster Lebens-
formen nach Bau, Funktionen, Systematik, mit Specialverzeichnis der in der
Schweiz beobachteten. Bern.
PETERSEN, C. G. Jou., and PETERSEN, P. BoysEN. 1911. Valuation of the sea. I.
Animal life of the sea bottom, its food and quantity. Rep. Danish Biol. Sta.
to Bd. Agric., 20: 1-76.
Petr, P. 1880. Spirogyra des environs de Paris. Paris.
Perxorr, St. 1914. Les Characées de Bulgarie. Nuova Notarisia, 25: 35-56.
Purtson, P. J. 1939. Freshwater algae of North and South Carolina. Part 1
Cyanophyceae. Jour. Elisha Mitchell Sci. Soc., 55: 83-116.
Puinney, Harry K: 1943.* The filamentous algae of northern Michigan. M. A.
thesis. Albion College. 1945. Notes on Cladophora. Amer. Midl. Nat., 84:
445. 1946.* A peculiar lake sediment of algal origin. Ibid., 35: 453-459.
Pieters, A. J. 1894.* Plants of Lake St. Clair. Bull. Mich. Fish. Comm., No.
we NII be
Piayrarr, G. I. 1915. Freshwater algae of the Lismore district with an appen-
dix on the algal fungi and Schizomycetes. Proc. Linn. Soc. N. S. Wales, 40:
310-362; Pls. 41-46. 1916. The genus Trachelomonas. Ibid., 40(1915):
[ 643 ]
1-41. 1916a. Oocystis and Eremosphaera. Ibid., 41: 107-147; Pls. 7-9; Figs.
1-28. 1917. Australian freshwater phytoplankton. Ibid., 41: 823-852; Pls.
56-59. 1918. New and rare freshwater algae. Ibid., 43: 497-543; Pls. 54-58;
Figs. 1-11. 1920. Peridineae of New South Wales. Ibid., 44( 1919): 793-818;
Pls. 41-43; Figs. 1-18. 1921. Australian freshwater flagellates. Ibid., 46:
99-146; Pls. 1-9; Figs. 1,2. 1923. Notes on freshwater algae. Ibid., 48:
206-228; Figs. 1-30.
PocuMan, A. 1942. Synopsis der Gattung Phacus. Arch. f. Protist., 95(No. 2):
81-252; Figs. 1-170.
Pococx, Mary A. 1933. Volvox and associated algae from Kimberly. Ann. S.
African Mus., 16: 473-521. 1933a. Volvox in South Africa. Ibid., 16:
523-646.
Porjansky, G. I. 1923. De nova Euglenarum specie. Not. Syst. Inst. Crypt.
Horti Bot. Petropol., 1(1922): 177-183.
Potiock, J. E. 1942.* Blue-green algae as agents in the deposition of mar]
in Michigan lakes. Ann. Rep. Mich. Acad. Sci., 20: 247-260; Pls. 16. 17.
Porzcrr, J. E. 1942.* Study on the rooted aquatic vegetation of Weber Lake,
Vilas County, Wisconsin. Trans. Wis. Acad. Sci., Arts, and Letters, 34:
149-166; Figs. 1-3.
Poutron, E. 1926.+ Etude sur les Heterokontées. Thesis, Univ. Genéve, Class.
Sci. Ser. 10, Fasc. 11: 96 pp.; Figs. 1-13.
Powers, E. B., Suretps, A. R., and Hickman, M. E. 1939. The mortality of
fishes in Norris Lake. Jour. Tenn. Acad. Sci., 14: 239-260.
Powers, J. H. 1905. New forms of Volvox. Trans. Amer. Microsc. Soca:
123-149; Pls. 11-14.
Prescott, G. W. 1927. The motile algae of Iowa. Univ. Iowa Studies Nat.
Hist., 12: 1-40; Pls. 1-10. 1931. Iowa algae. Ibid., 13: 1-235, Pls. 1-89.
193la. Iowa lake survey. A report to the Iowa State Fish and Game Com-
mission. Mimeographed. 1936. Notes on the algae of Gatun Lake, Panama
Canal. Trans. Amer. Microsc. Soc., 55: 501-509; Pls. LXIV-LXV. 1937.*
Preliminary notes on the desmids of Isle Royale, Michigan. Pap. Mich. Acad.
Sci., Arts, and Letters, 22: 201-212; Pl. 19. 1938.* A new species and a
new variety of the algal genus Vaucheria De Candolle with notes on the
genus. Trans. Amer. Microsc. Soc., 57: 1-10; Pls. 1, 2. 1938a. Objectionable
algae and their control in lakes and reservoirs. Municipal Rev., 1(No. 2/3)
[reprint; pages not numbered]. 1938b.* Further notes on the desmids of
Isle Royale, Michigan. The genus Cosmarium. Pap. Mich. Acad. Sci., Arts,
and Letters, 23: 203-214. 1939.* Some relationships of phytoplankton to
limnology and aquatic biology. In Problems of lake biology. Amer. Assoc.
Ady. Sci., Publ. No. 10: 65-78; Figs. 2-4. 1940.* Desmids of Isle Royale,
Michigan. The genera Staurastrum, Micrasterias, Xanthidium, and Euastrum,
with a note on Spinoclosterium. Pap. Mich. Acad. Sci., Arts, and Letters,
25(1939): 89-100. 1941.* A concluding list of desmids from Isle Royale,
Michigan. Ibid., 26(1940): 23-29; Pls. 1, 2. 1942. The fresh-water algae
of southern United States. II. Trans. Amer. Microsc. Soc., 61: 109-119. 1944.*
New species and varieties of Wisconsin algae. Farlowia, 1: 347-385. 1948.
Objectionable algae with reference to the killing of fish and other animals.
Hydrobiologia, 1(No. 1): 1-18.
Prescott, G. W., and CroaspaLe, Hannan T. 1937. New or noteworthy
fresh water algae of Massachusetts. Trans. Amer. Microse. Soc., 56: 269-—
282; Pls. 1-3. 1942. The algae of New England. II. Amer. Midl. Nat., 27:
662-676; Pls. 1-5.
Prescott, G. W., and Macnorra, ANGELINA. 1935.* Notes on Michigan des-
[ 644 ]
mids with descriptions of some species new to science. Pap. Mich. Acad.
Sci., Arts, and Letters, 20: 157-170.
Prescott, G. W., Sizva, H., and Wane, W. E. 1949.* New or otherwise inter-
esting fresh-water algae from North America. Hydrobiologia, 2(No. 1):
84-91; Pls. 1-2.
PrincsHEIM, E. G. 1942. Contributions to our knowledge of saprophytic algae
and flagellata. III. Astasia, Distigma, Menoidium and Rhabdomonas. New
Phytol., 41: 171-205.
PrincsHem, N. 1856. Untersuchungen ueber Befruchtung und Generations-
wechsel der Algen. Monatsber. d. Konigl. Akad. d. Wiss. z. Berlin, 1856:
925-237; 1 pl. Figs. 1-10. 1858. Beitriige zur Morphologie und Systematik
der Algen. Pringsh. Jahrb. Wiss. Bot., 1: 1-81; Pls. 1-6. 1860. Beitrage zur
Morphologie und Systematik der Algen. III. Die Coleochaeteen. Ibid., 2.
1-38; Pls. 1-6.
Printz, H. 1913. Eine systematische Uebersicht der Gattung Oocystis Nageli.
Nyt Mag. f. Natur., 51: 165-203; Pls. 4-6. 1914. Kristianiatraktens Proto-
coccoideer. Skr. Vidensk. i Kristiania. Mat.-Nat. KI., 1913(No. 6): 1-128;
Pls. 1-7. 1915. Beitriige zur Kenntnis der Chlorophyceen und ihrer ver-
breitung in Norwegen. Det. Kgl. Norske Vidensk. Selskabs Skrifter, 1915
(No. 2): 1-76. 1915a. Die Chlorophyceen des siidlichen Sibiriens und des
Uriankailandes. Ibid., 1915 (No. 4): 1-52; Pls. 1-7. 1927.+ Chlorophyceae.
In A. Engler and K. Prantl, Die Natiirlichen Pflanzenfamilien. 3: 1-463; Figs.
1-366. Leipzig. 1940.+ Vorarbeiten zu einer Monographie der Trentepohlia-
ceen. Nyt Mag. f. Natur., 80: 137-210.
Prircuarp, A. 1841. A history of infusoria, living and fossil. London. 1861.
A history of infusoria, including the Desmidiaceae and Diatomaceae, British
and foreign. 4th ed. London.
Pitter, A. 1909. Die Emahrung der Wassertiere und der Stoffhaushalt der
Gewiasser. Jena.
Rasennorst, L. 1847. Deutschlands Kryptogamen-Flora, oder Handbuch zur
Bestimmung der kryptogamischen Gewiichse Deutschlands, der Schweiz,
des Lombardisch-Venetianischen Kénigreichs und Istriens. H, No. 2. Algen.
Leipzig. 1849-1860. Die Algen Sachsen’s. 1863. Kryptogamen-Flora von
Sachsen, der Ober-Lausitz, Thiiringen und Nordbohmen, mit Beriicksi-
chtigung der benachbarten Linder. Erste Abtheilung. Leipzig. 1864-1868.
Florae Europaea algarum aquae dulcis et submarinae. 3 Vols. Leipzig.
Raciworski, M. 1889. Przeglad Gatunké6w Rodzaju Pediastrum. Rozpr. i
Sprawozd. Wydz. III, Akad. Umiej.'w. Krakowie, 20: 1-37.
Ratrs, J. 1844. On the British Desmidieae. Ann. and Mag. Nat. Hist., 14(Ser.
1): 187-194, 256-261, 391-396, 465-471. 1848. The British Desmidieae.
266 pp.; Pls. 1-35. London. 1850. On the Nostochineae. Ann. and Mag.
Nat. Hist., 5(Ser. 2): 321-343.
Ranpnawa, M. S. 1936. Contributions to our knowledge of the freshwater
algae of northern India. I. Oedogoniales. Proc. Indian Acad. Sci., 4: 97-107;
Pls. 6-8. 1937. Genus Zygnemopsis in northern India. Ibid., 5: 297-314; Figs.
1-8. 1938. Observations on some Zygnemales from northern India. Parts
LII. Ibid., 8: 109-150, 336-366; Figs. 1-58. 1939. Genus Vaucheria in
northern India. Arch. f. Protist., 92: 537-542.
Rao, C. B. 1936. The Myxophyceae of the United Provinces, India.—II. Proc.
Indian Acad. Sci., 3: 165-174; Figs. 1-3. 1937. The Zygnemoideae of the
United Provinces, India. I. Jour. Indian Bot. Soc., 16: 269-288. 1937a. The
Myxophyceae of the United Provinces, India.—III. Proc. Indian Acad. Sci.,
6: 339-375. 1938. The Zygnemoideae of the Central Provinces, India.—I.
Jour. Indian Bot. Soc., 17: 341-853.
[ 645 ]
Rawson, D. S. 1930. The bottom fauna of Lake Simcoe and its réle in the
ecology of the lake. Univ. Toronto Studies, Publ. Ontario Fish Res. Lab.,
No. 40. 1939. Some physical and chemical factors in the metabolism of lakes.
In Problems of Lake Biology. Amer. Assoc. Adv. Sci., Publ. No. 10: 9-26.
Raymonp, M. R. 1937.* A limnological study of the plankton of a concretion-
forming marl lake. Trans. Amer. Microsc. Soc., 56: 405-430.
Rayss, TscHarna. 1915. Le Coelastrum proboscideum Bohl. Etude de planc-
tologie expérimentale suivi d’une revision des Coelastrum de la Suisse.
Mater. pour la Flore Crypt. Suisse, 5: 1-65; Pls. 1-20. 1930. Microthamnion
Kuetzingianum Naeg. Bull. Soc. Bot.-Geneve, 21(Sér. 2): 143-160; Figs. 1-9.
Rew, C. B. 1939. The effect of stream conditions on lake plankton. Trans.
Amer. Micros. Soc. 58: 398-403.
ReEmnBOLD, D. T. 1890. Die Chlorophyceen (Griintange) der Kieler Fohrde.
Schrif. des naturw. Vereins f. Schleswig-Holstein, 8( Heft 1): 109-144.
RemnuaArp, E. G. 1931.* The plankton ecology of the upper Mississippi, Min-
neapolis to Winona. Ecol. Monogr., 1: 395-464; Figs. 1-11. 1941. Notes on
Aphanizomenon with a description of a new species. Amer. Jour. Bot., 28:
326-329.
RetnHarpt, L. 1876. Entwickelungsgeschichte der Characien (rossice). Pro-
toc. de Seckt der 5. Versamml. russ. Naturf. und Aerzte in Warschau. Warsaw.
REINKE, J. 1879. Zwei parasitische Algen. Bot. Zeit., 37: 473-478.
Rewscu, P. F. 1867. Die Algenflora des mittleren Theiles von Franken, ent-
haltend die vom Autor bis jetzt in diesen Gebieten beobachteten Siisswasser-
algen, etc. Abh. Naturh. Ges. Niimberg, 3(1866): 1-238; Pls. 1-3. (Also
printed separately, Niirnberg, 1867.) 1875. Contributiones ad algologeam et
tungologeam. Leipzig. 1878. Contributiones ad floram algarum aquae dulcis
Promontorii Bonae Spei. Jour. Linn. Soc. Bot., 16: 232-248. 1879. Eine
neues Genus der Chroolepideae. Bot. Zeit., 37: 361-366. 1887. Eine neue
Vaucheria der Corniculatae, sowie tiber gynandrische Bildung bei Vaucheria.
Ber. d. Deutsch Bot. Ges., 5: 189-192. 1888. Familiae Polyedriearum mono-
graphia. Notarisia, 3: 493-516; Pls. 4-8.
RENDLE, A. B., and West, W. 1899. A new British freshwater alga. Jour. Bot.,
87: 289-291.
Ricu, FLoreNnce. 1932. Contributions to our knowledge of the freshwater
algae of Africa. 10. Phytoplankton from South Africa Pans and Vleis. Trans.
Roy. Soc. S. Africa, 20(Pt. 2): 149-188. 1935. Contributions to our
knowledge of the freshwater algae of Africa. 11. Algae from a Pan in
Southern Rhodesia. Ibid., 23( Pt. 2): 107-160; Figs. 1-24.
Ricu, FLoRENcCE, and Pocock, Mary A. 1933. Observations on the genus
Volvox in Africa. Ann. S. African Mus., 16: 427-471.
Ricuter, P. 1884. In Literaturdfversigt. Algae aquae dulcis exsiccatae prae-
cipue scandinavicae quas adjectis chlorophyllaceis et phychromaceis dis-
tribuerunt Veit Wittrock et Otto Nordstedt. Bot. Notiser, 1884: 121-128.
1894. Gloiotrichia echinulata P. Richt., eine Wasserblute des Grossen und
Kleinen Pléner Sees. Forsch. Biol. Stat. z. Plén, 2: 31-47. 1896. Scenedesmus
Opoliensis P. Richt. nov. sp. Zeit. f. Angw. Mikro., 1: 83-7. 1897. Siisswasser-
algen aus dem Umanakdistrikt. Bibl. Bot., 8( Heft 42): 1-12.
Rickett, H. W. 1921.* A quantitative study of the larger aquatic plants of
Lake Mendota. Trans. Wis. Acad. Sci., Arts, and Letters, 20: 501-527.
1924.* A quantitative study of the larger aquatic plants of Green Lake,
Wisconsin. Ibid., 21: 381-414; Figs. 1-7.
Ritey, Gorpon A. 1939. Correlations in aquatic ecology, with an example of
their applications to problems of plankton productivity. Jour Marine Res. 2:
56-73; Figs. 14-16.
[ 646 |
Ripart, J. 1876. Notice sur quelques espéces rares ou nouvelles de la flore
cryptogamique de la France. Bull. Soc. Bot. France, 25: 158-168.
Rosinson, Cuas. Bupp. 1906.+ The Chareae of North America. Doctoral
thesis, Columbia University. New York,
Rox, J. 1925. Les nouvelles espéces des algues trouvées aux environs de la
station biologique du Donetz du Nord. (Russian with French summary. )
Arch. Russ. Protist., 4( No. 3/4): 187-152. 1926. Untersuchungen am Phyto-
plankton der Binnengewdsser in Ukaja. Ibid., 5: 1-44.
Rose, Eart T, 1934. Notes on the life history of Aphanizomenon flos-aquae.
Univ. Iowa Studies Nat. Hist., 16: 129-136.
RosENBERG, Marie. 1939. A discussion of freshwater biology and its appli-
cations. III. Algal physiology and organic production. Ann. Appl. Biol., 26:
172-174.
RostTAFINsKI, J. 1875. Quelques mots sur l’Haematococcus lacustris et sur les
bases d’une classification naturelle’ des algues Chlorospordes. Mem. Soc.
Nat. Cherbourg, 19: 137-154.
RosTAaFINSKI, J., and Worontn, M. 1877. Ueber Botrydium granulatum. Leip-
zig. Bot. Zeit., 35: 649-671; Pls. 7-11.
Rotu, A. W. 1797. Bemerkungen iiber das Studium der kryptogamischen Was-
sergewachse. Hannover. 1797-1806. Catalecta botanica, 1-3. Leipzig. 1800.
Tentamen florae germanicae. Vol. 3. Leipzig.
RoussE.ET, C. F. 1914. Remarks on two species of African Volvox. Jour. Que-
kett Microsc. Soc., 12( Ser. 2): 3938-394.
Sanpor, Lancer. 1934. A Spirogyrak. A Spirogyrak monografikus Feldolo-
gozdsa, Kulénés Tekintettel Nagymagyaroszagra. Folia Crypt., 1: 1253-1304.
SAUNDERS, DE ALTON. 1894. Protophyta-Phycophyta. Flora of Nebraska. Vol.
L. Lincoln.
Sawyer, C. N., Lackey, J. B., and Lenz, A. T. 1943.* Investigation of the
odor nuisance occurring in the Madison Lakes particularly Lakes Monona,
Waubesa and Kegonsa from July 1942 to July 1943. A mimeographed re-
port to the Hon. S. Goodland, Acting Governor of Wisconsin.
ScHAaRscHMipT-IstvanFFI, J. 1881. Specimen Phycologiae aequatoriensis. Mag-
yar Novenytanu Lapok, 5: 17-24.
ScHERFFEL, A. 1899. Phaeocystis globosa n. sp. Ber. d. Deusch. Bot. Ges., 17:
317-318. 1908. Asterococcus n. g. superbus (Cienk.) Scherffel und dessen
angebliche Beziehungen zu Eremosphaera. Ibid., 26A: 762-771. 1908a.
Einiges zur Kenntnis von Schizochlamys gelatinosa A. Br. Ibid.: 783-795.
1911. Beitrag zur Kenntnis der Chrysomonadineen. Archit. Proust.) 22:
299-344.
ScHEwrAkorFr, W. 1893. Ueber die geographische Verbreitung der Siisswasser-
Protozoén. Mém. Acad. Imper. Sci. St. Pétersb., 41(Ser. 7): 1-201.
ScHiLLER, J. 1933-1937.+ Dinoflagellatae. In L. Rabenhorst, Kryptogamen-
Flora von Deutschland, Oesterreich und der Schweiz. 10(1933), Teil 1:
1-617; Teil 2, Lf. 1(1935): 1-160; Lf. 2(1935): 161-320; Lf. 3(1937):
321-480; Lf. 4(1937): 481-590. Leipzig.
Scumuine, A. J. 1891. Die Siisswasser-Peridineen. Flora Allgm. Bot. Zeit., 74:
220-299. 1913. Dinoflagellatae (Peridineae). In A. Pascher, Die Siisswasser-
flora Deutschlands, Oesterreichs und der Schweiz. Heft 3: 1-66; Figs. 1-69.
ena.
ee cans L. 1925. Myxophycearum in provincia Charkoviensi ( Ukrainae )
inventarum novae species et varietates. Not. Syst. Inst. Crypt. Horti Bot.
Petropol., 2(No. 6): 87-89.
ScuMarpa, L. K. 1850. Neue Formen von Infusorien. Denschr. Kais. Akad.
Wiss. Wien, 1( Abt. 2): 9-14; Pls. 3, 4. 1854. Zur Naturgeschichte Aegyptens.
Ibid., 7( Abt. 2): 1-28.
ScumMiLE, W. 1893. Beitrige zur Algenflora des Schwarzwaldes und der
Rheinebene. Ber. d. Natur. Ges. Freiburg, 7: 1-45 (68-112, double paging )
[ 647 J
1894. Aus der Chlorophyceen-Flora der Torfstiche zu Virnheim. Flora, 78:
42-66; Pl. 7. 1895. Weitere Beitrage zur Algenflora der Rheinebene und des
Schwarzwaldes. Hedwigia, 34: 66-83. 1895a. Einige Algen aus Sumatra.
Ibid., 34: 293-307; Pl. 4. 1897. Algen aus den Hochseen des Kaukasus.
Rep. Bot. Gard. Tiflis, 2: 267-276. 1897a. Beitrage zur Algenflora des
Schwarzwaldes und des Oberrheins. VI. Hedwigia, 36: 1-25. 1897b. Algolo-
gishen Notizen. II. Conferva Sandvichense Ag. Allg. Bot. Zeitschr., 3: 3-4.
1897c. Algologische Notizen. V—VII. Ibid., 3: 107-108. 1898. Ueber einige
von Prof. Lagerheim in Ecuador und Jamaika gesammelte Blattalgen. Hed-
wigia, 37: 61-75. 1898a. Ueber einige von Knut Bohlin in Pite Lappmark und
Vesterbotten gesammelte Siisswasseralgen. Bih. Kongl. Sv. Vet.-Akad. Handl.,
24, Afd. 3, No. 8: 1-71. 1899. Vier neue Siisswasseralgen. Oesterr. Bot. Zeit.,
1899(No. 1): 1-4. 1899a. Einige Algen aus preussischen Hochmooren.
Hedwigia, 38: 156-176. 1900. Algologische Notizen. VHI-IX. Allgm. Bot.
Zeitschr., 5(1899): 2-4. 1900a. Algologische Notizen. X—XIII. Ibid., 5:
17-20. 1900b. Ueber einige von Professor Hansgirg in Istindien gesammelte
Siisswasseralgen. Hedwigia, 39: 160-190. 1900c. Einige von Dr. Holderer
in Centralasien gesammelte Algen. Ibid., 39: [141-143]. 1900d. Ueber Plank-
tonalgen und Flagellaten aus dem Nyassasee. Engler’s Bot. Jahrb., 27:
229-237; Pls. 1-3. 1900e. Beitrage zur Kenntniss der Planktonalgen. Ber. d.
Deutsch. Bot. Ges., 18: 144-158. 1900f. Drei interessante tropische Algen.
Bot. Centralbl., 81: 417-418. 1900g. Algen des Siisswassers. Ber. d. Deutsch.
Bot. Ges., 18: [107-117]. 1901. Algologische Notizen. XV. Allg. Bot. Zeitschr.,
6: 233-235. 190la. Ueber drei Algengenera. Ber. d. Deutsch. Bot. Ges., 19:
10-24. 1901b. In Beitrage zur Flora von Afrika XXII. Schizophyceae, Con-
jugate, Chlorophyceae. Engler’s Bot. Jahrb., 30: 239-445. 1902. Notizen
zu einigen Siisswasseralgen. Hedwigia, 41: 150-163. 1902a. In Hans Simmer,
Vierter Bericht tiber die Kryptogamenflora der Kreuzeckgruppe in Karnten.
Allg. Bot. Zeitschr., 7(1901): 41-43, 83-86. 1903. Algen, insbesondere
solche des Plankton, aus dem Nyassa-See und seiner Umgebung gesammelt
von Dr, Fiilleborn. Engler’s Bot. Jahrb., 32(1902): 56-88; Pls. 1-3. 1903a.
Bemerkungen zu einigen Siisswasseralgen. Ber. d. Deutsch. Bot. Ges., 21:
346-855.
Scumupt, J. 1899. Danmarks blaagrénne Alger (Cyanophyceae Daniae). Bot.
Tidsskr., 22: 2838-419.
Scuomer, H. A., and Jupay, C. 1935.* Photosynthesis of algae at different
depths in some lakes of northeastern Wisconsin. I. Observations of 1933.
Trans. Wis. Acad. Sci., Arts, and Letters, 29: 173-193.
ScuHraMM, J. R. 1914. A contribution to our knowledge of the relation of certain
species of grass-green algae to elementary nitrogen. Ann. Missouri Bot. Gard.,
1: 157-184.
ScurANk, F. von Pau. 1783. Botanische Rhapsodien. Der Naturforscher, 19:
116-128. 1793. Mikroskopische Wahrnehmungen. Ibid., 27: 26-87.
ScHROEDER, B. 1897. Ueber das Plankton der Oder. Ber. d. Deutsch. Bot. Ges.,
15: 482-492. 1897a. Die Algen der Versuchsteiche des Schles. Fischerei-
vereins zu Trachenberg. Forsch. Biol. Stat. z. Plén, 5: 29-66. 1898. Neue
Beitrage zur Kenntnis der Algen des Riesengebirges. Ibid., 6: 9-47; Pls.
1, 2. 1898a. Planktologische Mittheilungen. Biol. Centralbl., 18: 525-535.
1899. Das Plankton des Oderstromes. B. Das pflanzliche Plankton der Oder.
Forsch. Biol. Stat. z. Plén, 7: 15-24. 1902. Untersuchungen iiber Gallert-
bildung der Algen. Ver. Naturh. med. Vereins Heidelberg, 7: 139-196. Pls.
1, 2. 1920. Schwebepflanzen aus dem Saarbor-Seen und aus den grosseren
Seen bei Liegnitz. Ber. d. Deutsch. Bot. Ges., 38: 122-135.
[ 648 J
Scuuette, H. A. 1918.* A biochemical study of the plankton of Lake Men-
dota. Trans. Wis. Acad. Sci., Arts, and Letters, 19(Pt. 1): 594-613.
ScHuETTE, H. A., and ALprer, H. 1929.* A note on the chemical composition of
Chara from Green Lake, Wisconsin. Trans. Wis. Acad. Sci., Arts, and
Letters, 24: 141-145.
ScCHUETTE, H. A., and HorrMan, A.ice E. 1921.* Notes on the chemical
composition of some of the larger aquatic plants of Lake Mendota. I. Clado-
phora and Myriophyllum. Trans. Wis. Acad. Sci., Arts, and Letters, 20:
529-531.
Scuuuze, B. 1927. Zur Kenntnis einiger Volvocales. Arch. f. Protist., 58:
508-576.
Scuutt, F. 1896. Peridiniales. In A. Engler and K. Prantl, Die natiirlichen
Pflanzenfamilien. Teil 1, Abt. 1. Leipzig.
SecxT, H. 1922. Estudios hidrobiologicos en la Argentina—Flagellatae. Bol.
Acad. Nac. Cienc. Cordoba, 25: 430-490. 1938. Contribucién al conocimiento
de las algas aerofilas en la Argentina. Ibid., 34: 108-141.
Sexico, A. 1887. Untersuchungen iiber Flagellaten. Beitr. Biol. Pflanzen, 4:
145-180; P1.8.
SENN, G. 1899. Ueber einige coloniebildende einzellige Algen. Bot. Zeitg., 57:
39-104; Pls. 2-3. 1900. Flagellata. In A. Engler and K. Prantl, Die Natiir-
lichen Pflanzenfamilien. Teil 1, Abt. 2: 93-192; Figs. 63-140. Leipzig.
SETCHELL, Wo. A. 1895. Notes on some Cyanophyceae of New England. Bull.
Torr. Bot. Club, 22: 424-431. 1896. Notes on Cyanophyceae. I. Erythea, 4:
87-89. 1896a.* Notes on Cyanophyceae. II. Ibid., 4: 189-194.
SETCHELL, Wm. A., and Garpner, N. L. 1903.+ Algae of Northwestern
America. Univ. Calif. Publ. Bot., 1: 165-418; Pls. 17-27.
SEVILLE-KENT, W. 1880-1882. A manual of the Infusoria. London.
SHaw, W. R. 1894. Pleodorina, a new genus of the Volvocineae. Bot. Gaz.,
19: 279-288; Pl. 27.
Simmer, Hans. 1898. Erster Bericht iiber die Kryptogamenflora der Kreu-
zeckgruppe in Karnthen. Allg. Bot. Zeitschr., 4: 74-78; 99-100; 118-120;
141-144; 158-159. 1901. Vierter Bericht iiber die Kryptogamen-flora der
Kreuzeckgruppe in Karnten. [bid., 7: 41-48, 83-86.
Sincu, R. N. 1938. The Oedogoniales of the United Provinces, India. Proc.
Indian Acad. Sci., 8: 373-395.
Stropot, S. 1884.+ Les Batrachospermes. Organisation, fonctions, développe-
ment, classification. Paris.
Sxuja, H. 1926. Zwei neue Zygnemaceen mit blauem Mesospor. Acta Horti
Bot. Univ. Latviensis, 1: 109-114; 1 pl. 1926a. Vorarbeiten zu einer Algen-
flora von Lettland. I. Ibid., 1: 33-54. 1926b. Vorarbeiten zu einer Algenflora
von Lettland. II. Ibid., 1: 149-178. 1927. Vorarbeiten zu einer Algenflora
von Lettland. HI. Ibid., 2: 51-116. 1928. Vorarbeiten zu einer Algenflora
von Lettland. IV. Ibid., 3: 103-218; Pls. 14. 1930. Siisswasseralgen von
den westestnische Inseln Saaremaa und Hiiumaa. Ibid., 4(1929): 1-74.
1931. Untersuchungen iiber die Rhodophyceen des Siisswassers. Arch. f.
Protist., 74: 297-308. 1934. Beitrag zur Algenflora Lettlands I. Acta Horti
Bot. Univ. Latviensis, 7(1932): 25-86. 1935. Die Flechte Coenogonium
nigrum (Huds.) Zahlbr. und ihre Gonidie. Ibid., 8: 21-44. 1937. Siisswas-
seralgen aus Griechenland und Kleinasien gesammelt von Prof. C. Regel.
Hedwigia, 77: 15-70; Pls. 1-3. 1938. Die Siisswasserrhodophyceen der
Deutschen Limnologischen Sunda-Expedition. Arch. f. Hydrobiol. (Suppl. )
15: 603-637; Pls. 29-35. 1939. Beitrag zur Algenflora Lettlands. II. Acta
Horti Bot. Univ. Latviensis, 11/12: 41-169. 1939a. Versuch einer systema-
tischen Einteilung der Bangioideen oder Protoflorideen. Ibid., 11/12: 23-40.
[ 649 ]
1948. Taxonomie des Phytoplanktons einiger Seen in Uppland, Schweden.
Symbol. Bot. Upsal., 9(No. 3): 1-399; Pls. 1-39.
Sxvortzow, B. W. 1917. Ueber Flagellata aus Mandschurei. Zhurnal Mikrobiol.
(Petrograd), 4(No. 1/2): 55-77. 1919. Notes on the agriculture, botany
and the zoology of China. XXXI. On new flagellata from Manchuria. Jour.
N. China Branch Roy. Asiatic Soc., 50: 96-104. 1922. On the winter phyto-
plankton of the fishponds of Foochow. Ibid., 53: 190-195. 1925. Die
Euglenaceengattung Trachelomonas Ehrenberg. Eine systematische Ueber-
sicht. Sungari Station zu Harbin der Ges. z. erforschung der Mandschurei,
1(No. 2): 1-101; Pls. 1-8. 1925a. Ueber einige Siisswasseralgen Umgegend
von Peking (China). Arch. f. Hydrobiol. u. Planktonk., 16: 337-340. 1925b.
Zur Kenntnis der Mandschurischen Flagellaten. Beih. Bot. Centralbl., 41
(Abt. 2): 811-315. 1925c. Ueber neue und wenig bekannte Formen der
Euglenaceengattung Trachelomonas Ehrenberg. Ber. d. Deutsch. Bot. Ges.,
43: 306-315. 1926. Ueber einige Siisswasseralgen aus der Nord-Mandschurei,
im Jahre 1916 gesammelt. Arch. f. Hydrobiol. u. Planktonk., 16(Heft 3):
421-436; Figs. 1-8. 1927. Ueber neue und wenig bekannte Formen der
Euglenaceengattung Trachelomonas Ehrenb. II. Ber. d. Deutsch. Bot. Ges.,
44: 603-621. 1928. Die Euglenaceengattung Phacus Dujardin. Ibid., 46:
105-125; Pl. 2. 1929. Einige neue und wenig bekannte Chlamydomonadaceae
aus Manchuria. Arch. f, Protist., 66: 160-163.
Smitu, Gitpert M. 1913.* Tetradesmus, a new four-celled coenobic alga. Bull.
Torr. Bot. Club, 40: 75-87; Pl. 1. 1914.* The organization of the colony of
certain four-celled coenobic algae. Trans. Wis. Acad. Sci., Arts, and Letters,
17 (Pt. If): 1165-1220; Pls. 85-91. 1916.* New or interesting algae from
the lakes of Wisconsin. Bull. Torr. Bot. Club, 43: 471-488; Pls. 24-26.
1916a.*+ A monograph of the algal genus Scenedesmus, based upon pure
culture studies. Trans. Wis. Acad. Sci., Arts, and Letters, 18: 422-539; Pls.
25-33. 1916b.* A preliminary list of the algae found in Wisconsin lakes.
Ibid., 18(Pt. IL): 531-565. 1917.* The vertical distribution of Volvox in
the plankton of Lake Monona. Amer. Jour. Bot., 5: 178-185. 1918.7 A
second list of algae found in Wisconsin lakes. Trans. Wis. Acad. Sci., Arts,
and Letters, 19: 614-654; Pls. 10-15. 1920.*+ Phytoplankton of the inland
lakes of Wisconsin. Part. 1. Wis. Geol. and Nat. Hist. Surv., Bull. 57: 1-243;
Pls. 1-51. 1922. The phytoplankton of the Muskoka region, Ontario, Canada.
Trans. Wis. Acad. Sci., Arts, and Letters, 20: 323-364; Pls. 8-13. 1922a.
The phytoplankton of some artificial pools near Stockholm. Arkiv f. Bot.,
17(No, 13): 1-8; Figs. 1-28. 1924. Ecology of the plankton algae in
Palisades Interstate Park, including the relation of control methods to fish
culture. Roosevelt Wild Life Bull., 2: 95-195; Pls. 3-24. 1924a.*+ Phyto-
plankton of the inland lakes of Wisconsin. II. Wis. Geol. and Nat. Hist.
Surv., Bull. 57: 1-227; Pls. 52-88. Madison. 1926. The plankton algae
of the Okoboji region. Trans. Amer. Microsc. Soc., 45: 156-233; Pls. 1-20.
1930. Notes on the Volvocales. I-IV. Bull. Torr. Bot. Club, 57: 359-370;
Pls. 17,18. 1931. A consideration of the species of Eudorina. Ibid., 57:
359-364; Pl. 17. 1933.*+ Freshwater algae of the United States. 716 pp.;
Figs. 1449. New York. 1937. Cryptogamic Botany. Vol. I. 545 pp.; Figs.
1-292. New York. 1944.* A Comparative study of the species of Volvox.
Trans. Amer. Microsc. Soc., 63: 265-310; Figs. 1-46.
Smitu, Girpert M., and Kiyver, F. D. 1929. Draparnaldiopsis, a new member
of the algal family Chaetophoraceae, Trans. Amer. Microsc. Soc., 48: 196-
208; Pl. 25; Fig. 1.
Smitu, J. E. 1790. English Botany, or coloured figures of British plants. London.
Smitu, L. L. 1941.* A limnological investigation of a permanently stratified
[ 650 ]
lake in the Huron Mountain region of Michigan. Pap. Mich. Acad. Sci., Arts,
and Letters, 26 (1940): 281-296.
Snow, Jura. 1899.* Ulvella Americana. Bot. Gaz., 27: 309-314; Pl. 7. 1899a.*
Pseudopleurococcus, nov. gen. Ann. Bot., 13: 189-195; Pl. 11. 1903. The
plankton algae of Lake Erie, with special reference to the Chlorophyceae.
Bull. U. S. Fish. Comm., 1902: 369-394. 1911. Two epiphytic algae. Bot.
Gaz., 51: 360-368; Pl. 18.
SOMMERFELDT, S. G. 1824. Physisk-Oeconomisk Beskrivelse over Saltdalen i
Nordlandene. Det. Kgl. Norske Vid. Selsk-Skr. i det., 19th Aarh, 2: 1-148.
STEIN, F. R. von. 1862. Der Organismus der Infusionsthiere. II, Abteilung;
Naturgeschichte der heterotrichen Infusorien. Leipzig. 1878. Der Organ-
ismus der Flagellaten nach einigen Forschungen in systematischer Reinen-
folge bearbeitet. Der Organismus der Infusionstiere. III Abteilung. I Hifte.
Die Naturgeschichte der Flagellaten oder Geisselinfusorien. Den noch nicht
abgeschlossenen allgemeinen Teil nebst Erklarung der somtlichen Abbildun-
gen enthaltend. 154 pp. Leipzig. 1883. Der Organismus der Infusionsthiere
nach eigenen Forschungen in systematischer Reinenfolge bearbeitet. III
Abteilung. II Hialfte. Die Naturgeschichte der Arthrodelen Flagellaten. 30
pp. Leipzig.
SticknEY, M. E. 1909.* Notes on Spondylomorum quaternarium Ehrenb. Bull.
Sci. Lab. Denison Univ., 14: 233-238; Pl. 6.
STIZENBERGER, Ernst. 1852. Spirulina und Arthrospira nov. gen. Hedwigia,
1: 32-34.
StockmayeER, S. 1890. Ueber die Algengattung Rhizoclonium. Ver. K. K. Zool.-
Bot. Ges. Wien, 40: 571-586.
Sroxes, A. C. 1885. Notes on some apparently undescribed forms of fresh-
water infusoria. No. 2. Amer. Jour. Sci., 29(Ser. 3): 313-328; Pl. 3. 1885a.
Notices of new fresh-water infusoria. IV. Amer. Monthly Microsc. Jour., 6:
183-190. 1886. Notes on Peridinium and other infusoria. Jour. Trenton Nat.
Hist. Soc., 1(No. 1): 18-22. 1886a. Notices of new fresh-water infusoria.
Proc. Amer. Philos. Soc., 23: 562-568; 1 pl. 1886b. Notices of new fresh-
water infusoria. V. Amer. Monthly Microsc. Jour., 7: 81-86; Figs. 1-18.
1887. Notices of new fresh-water infusoria. VI. Ibid., 8: 141-147. 1888. A
preliminary contribution toward a history of the freshwater infusoria of the
United States. Jour. Trenton Nat. Hist. Soc., 1(No. 3): 71-819; Pls. 1-13.
1890. Notices of new fresh-water infusoria. Proc. Amer. Philos. Soc., 28:
74-80; 1 pl. 1894. Notices of presumably undescribed infusoria. Ibid., 33:
838-344.
STRASBURGER, E. 1884. Das botanische Practicum. Jena.
STRICKLAND, J. C. 1940. The Oscillatoriaceae of Virginia. Amer. Jour. Bot.,
27: 628-633; Fig. 1.
StrOM, K. Munster. 1921. The phytoplankton of some Norwegian Lakes.
Videns. Skrift. I. Mat.-Nat. K]., 1921(No. 4): 1-51; Pls. 1-3. 1926. Norwe-
gian mountain algae. Det. Norske Vid.-Akad. Oslo. I. Mat.-Nat. Kl. 1926
(No. 6): 1-263; 25 pls. 1928. Production biology of temperate lakes. Inter.
Rev. Ges. Hydrobiol. u. Hydrogr., 19: 329-348.
SuRBER, EucENE W. 1929. The utilization of sloughs in the Upper Mississippi
Wild Life and Fish Refuge as fish ponds. Trans. Amer. Fish. Soc., 59:
106-1138.
Swincte, W. T. 1894.* Cephaleuros mycoidea and Phyllosiphon, two species
of parasitic algae new to North America. Proc. Amer. Assoc. Adv. Sci., 42:
260.
Swirenxo, D. O. 1914. Zur Kenntnis der russischen Algenflora. I. Die Eug-
lenaceengattung Trachelomonas. Arch. f. Hydrobiol. u. Planktonk., 9: 630-
[ 651 }
647, 1915. Materialy k florie vodoroslei Rossii. Niepotoryia dannyia k sis-
tematikie i geografii Euglenaceae. Obschchestvo Ispytatelei Prirody, Khar’kov.
Trudy, 48(No. 1): 67-148. 1915a. Zur Kenntnis der russischen Algenflora.
II. Euglenaceae (excl. Trachelomonas). Arch. f. Hydrobiol. u. Planktonk.,
10: 321-339, 1928. Contributions a l'étude algologique de l'Ingoule. (Russian
with French summary.) Arch. Russ. Protist., 7: 75-130
Tart, C. E. 1935. The Oedogoniaceae of Oklahoma including new species and
varieties. Bull. Torr. Bot. Club, 62: 281-290; Pls. 15, 16. 1937. A new species
of Vaucheria. Ibid., 64: 557; 1 fig. 1939.* Additions to the algae of Mich-
igan. Ibid., 66: 77-85; Figs. 1-12. 1942. Additions to the algae of the west
end of Lake Erie. Ohio Jour. Sci., 42: 251-256; Pls. 1,2. 1946. Some
Oedogoniaceae and Zygnemataceae from Texas and Louisiana. Trans. Amer.
Microsc. Soc., 65: 18-26; 1 pl. 1949.* New, rare, or otherwise interesting
algae. Trans. Amer. Microsc. Soc., 68: 208-216, Pls. 1, 2.
TANNER-FULLMAN, M. 1906. Sur un nouvel organisme du plancton du Schoen-
enbodensee le Raphidium Chodati Tanner. Bull. Herb. Boiss., 6(Ser. 2):
156-158.
TayLor, WM. RANpotpH. 1922. Notes on some algae from British Columbia.
Rhodora, 24: 101-111. 1924. Further notes on British Columbia algae. Ibid.,
26: 160-166. 1928. Alpine algal flora of the mountains of British Columbia.
Ecology, 9: 343-348. 1932. Notes on the genus Anabaenopsis. Amer. Jour.
Bot., 19: 454-463; Pls. 39,40. 1933. Methods for collection and study of
fresh-water algae. Jour. Mich. Schoolmasters Club, 1933: 114-125. 1935.
Alpine algae from the Santa Marta Mountains, Colombia. Amer. Jour. Bot.,
22: 763-781; Pls. 1-3. 1935a.* Phytoplankton of Isle Royale. Trans. Amer.
Microsc. Soc., 54: 83-97; Pls. 14-17. 1937.+ Marine algae of the northeastern
coast of North America. 427 pp.; Pls. 1-60. Ann Arbor.
Taytor, WM. Ranpotpn, and Corton, H. S. 1928. The phytoplankton of some
Arizona pools and lakes. Amer. Jour. Bot., 15: 596-614; Pls. 46, 47.
Temtinc, E. 1912. Schwedische Planktonalgen. I., Phytoplankton aus dem
Rastasj6n bei Stockholm. Svensk Bot. Tidskr., 6: 266-281. 1916. Ibid., I.
Tetrallantos, eine neue Gattung der Protococcoideen. Ibid., 10: 59-66; F igs.
1-15. 1941. Aeruginosa oder flos-aquae, eine Kleine Microcystis-studie. Ibid.,
35(No. 4): 337-349; Figs. 1-12. 1946. Zur Phytoplanktonflora Schwedens.
Bot. Notiser, 1946: 61-88; Figs. 1-22.
TemMPeERLy, B. N. 1936. The boghead controversy and the morphology of the
boghead algae. Trans. Roy. Soc. Edinburgh, 58(Pt. 3): 855-868.
TrEoporesco, E. C. 1907. Matériaux pour la flore algologique de la Roumaine.
Beih. Bot. Centralbl., 21(No. 2): 103-219.
THIENEMANN, Aucust. 1935. Die Bedeutung der Limnologie fiir die Kultur
der Gegenwart. Stuttgart.
Tompson, H. D. 1896.* Report on the plants. Appendix I. In A biological
examination of Lake Michigan in the Traverse Bay region. Bull. Mich. Fish.
Comms, 63) 3=93) Elssl=3:
THompson, R. H. 1938. A preliminary survey of the freshwater algae of eastern
Kansas. Univ. Kansas Sci. Bull., 25: 5-83; Pls. 1-12. 1938a. Coronastrum,
a new genus of algae in the family Scenedesmaceae. Amer. Jour. Bot., 25:
692-694; Figs. 1-10. 1947. Fresh-water Dinoflagellates of Maryland. State
Md. Bd. Nat. Resources, Publ. No. 67: 3-24; Pls. 1-4. 1949. Immobile
Dinophyceae. I. New records and a new species. Amer. Jour. Bot., 36 (No.
3): 301-308; Figs. 1-34.
THuNMARK, S. 1945. Die Abwasserfrage der Vaxjoseen in hydrobiologische
Beleuchtung. Medd. f. Lunds Univ. Limnol. Inst., No. 4: 1-239; Figs. 146.
Tuuret, G. 1850. Recherches sur les zoospores des algues et les anthéridies
[ 652 }
des cryptogames. Ann. Sci. Nat. Bot., 14(Sér. 3): 214-260; Pls. 16-81. 1875.
Essai de classification des Nostochinées. Ibid., 1(Sér. 6): 372-382. 1885. In
Hauck, F. 1885. Des Meeresalgen Deutschlands und Oesterreichs. Raben-
horst’s Kryptogamen-Flora. 2. Leipzig. 1887. In E. Bornet and Ch. Flahault,
Revision des Nostocacées. Ann. Sci. Nat. Bot., 5(Sér. 7): 51-129.
Tuuret, G., and Bornet, E. 1878. Etudes phycologiques. Paris.
Tirrany, L. H. 1921. New forms of Oedogonium. Ohio Jour. Sci., 21: 272-274.
1921a. Algal food of the young gizzard shad. Ibid., 21: 113-122. 1924. Some
new forms of Spirogyra and Oedogonium. Ibid., 24: 180-190; Pls. 1-3. 1926.
The filamentous algae of northwestern Iowa, with special reference to the
Oedogoniaceae. Trans. Amer. Microsc. Soc., 45: 69-132; Pls. 1-16. 1926a.
The algal collection of a single fish. Pap. Mich. Acad. Sci., Arts, and Letters,
6: 303-306. 1927. New species and varieties of Chlorophyceae. Bot. Gaz.,
83: 202-206; Pl. 9. 1928. The algal genus Bulbochaete. Trans. Amer. Mi-
crosc. Soc., 47: 121-177; Pls. 14-23. 1929. A key to the species, varieties,
and forms of the algal genus Oedogonium. Ohio Jour. Sci., 29: 62-80.
1930.t* The Oedogoniaceae, a monograph. 188 pp.; 64 pls. Columbus,
Ohio. 1934.+* The Oedogoniaceae. Supplementary paper number one. Ohio
Jour. Sci., 34: 323-326. 1934a. The plankton algae of the west end of Lake
Erie. Ohio State Univ., Franz Theodore Stone Lab., Contrib. No. 6. 112 pp.;
Figs. 1-374. 1936. Wille’s collection of Puerto Rican fresh-water algae.
Brittonia, 2: 165-176; Pls. 1-3. 1936a. New species of Oedogonium. Trans.
Amer. Microsc. Soc., 55: 1-5; Pl. 1. 1937.+ Oedogoniales. Oedogoniaceae. N.
Amer. Flora, 11, Part 1. 102 pp. New York Bot. Gard. 1937a. The filamentous
algae of the west end of Lake Erie. Amer. Mid]. Nat., 18: 911-951; Pls. 1-9.
1937b. Brazilian Oedogoniales. Rev. Sudamer. Bot., Montevideo, 4: 5—14;
Figs. 1-6. 1938. Algae: the grass of many waters. Springfield, Ill.
Tirrany, L. H., and Antsrrom, E. H. 1931. New and interesting plankton
algae from Lake Erie. Ohio Jour. Sci., 31: 455-467; Pls. 1-3.
Turrany, L. H., and Brirron, M. E. 1944. Freshwater Chlorophyceae and
Xanthophyceae from Puerto Rico. Ohio Jour. Sci., 44: 39-50.
Trrrany, L. H., and Transeau, E. N. 1927. Oedogonium periodicity in the
north central states. Trans. Amer. Microsc. Soc., 46: 166-174; Figs. 1-3.
TitpeN, JoserHine E. 1895. List of freshwater algae collected in Minnesota
during 1884. Minn. Bot. Studies, 1(No. 20): 228-237. 1898. List of fresh-
water algae collected in Minnesota during 1896 and 1897. Ibid., 2( No. 3):
25-29. 1910.* Minnesota algae. I. 328 pp.; Pls. 1-20. Minneapolis. 1935.
The algae and their life relations. 550 pp.; Figs. 1-257. Minneapolis.
TrmBerLake, H. G. 1902.* Development and structure of the swarmspores of
Hydrodictyon. Trans. Wis. Acad. Sci., Arts, and Letters, 13: 486-522.
TransEau, E. N. 1913. The periodicity of algae in Illinois. Trans. Amer.
Microsc. Soc., 32: 31-40; Figs. 1-8. 1913a. Annotated list of algae of eastern
Illinois. Trans. Ill. Acad. Sci., 6: 69-89. 1913b. The life history of Gloeo-
taenium. Bot. Gaz., 55: 66-73; Pl. 3. 1914. New species of green algae. Amer.
Jour. Bot., 1: 289-301; Pls. 25-29. 1915.* Notes on the Zygnemales. Ohio
Jour. Sci., 16: 17-31. 1916. The periodicity of freshwater algae. Amer. Jour.
Bot., 3: 121-133; Figs. 1-3. 1917.* The algae of Michigan. Ohio Jour. Sci.,
17: 217-232. 1925.t* The genus Debarya. Ibid., 25: 193-199; Pls. 1, 2.
1926.+* The genus Mougeotia. Ibid., 26: 311-351; Pls. 1-7. 1933.+* The
genus Zygogonium. Ibid., 33: 156-162; Pls. 1, 2. 1934.+* The genera of the
Zygnemataceae. Trans. Amer. Microsc. Soc., 53: 201-207. 1934a. Notes on
the Zygnemataceae. Ohio Jour. Sci., 34: 420. 1938. Notes on Zygnemataceae.
Amer. Jour. Bot., 25(7): 524-528; Figs. 1-19. 1943. Two new Ulotrichales.
[ 653 ]
Qhio Jour. Sci., 43: 212-213. 1944. Notes on Zygnemataceae. Ibid., 44:
243-244,
TransEau, E. N., and Tirrany, L. H. 1919. New Oedogoniaceae. Ohio Jour.
Sci., 19: 240-243.
TransEau, E. N., Tirrany, L. H., Tart, C. E., and Li, L. C. 1934.* New
species of Zygnemataceae. Trans. Amer. Microsc. Soc., 53: 208-230; Pls.
17-21.
TRELEASE, W. 1889.* The “working” of the Madison Lakes. Trans. Wis. Acad.
Sci., Arts, and Letters, 7: 121-129.
TressLer, W. L. 1939. The zooplankton in relation to the metabolism of lakes.
In Problems of Lake Biology. Amer. Assoc. Adv. Sci., Publ. No. 10: 79-93.
TressLeR, W. L., and Domoca.xa, B. P. 1931.* Limnological studies of Lake
Wingra. Trans. Wis. Acad. Sci., Arts, and Letters, 26: 331-351.
TressLer, W. L., Tirrany, L. H., and Spencer, W. P. 1940. Limnological
studies of Buckeye Lake, Ohio. Ohio Jour. Sci., 40: 261-290.
Troirzkaya, O. V. 1922. De Carteriis nonnullis minus cognitis notulae. Not.
Syst. Inst. Crypt. Horti Bot. Petropol., 1(No. 8): 114-119. 1922a. De
varietate nova Anabaena Scheremetievi Elenk. Ibid., 1( No. 5): 77-78. 1928.
Chlamydomonas sphaerica Troitzk. nov. sp. Ibid., 2(No. 6): 81-82. 19238a.
De affinitate inter Coelosphaerium Nag. et Gomphosphaerium Kitz. Ibid.,
2(No. 5): 69-78.
Turner, W. B. 1893. Algae aquae dulcis Indiae orientalis. Kongl. Sv.-Vet.
Handl., 25( No. 5): 1-187; Pls. 1-23.
Turpin, P. J. 827. Dictionnaire des Sciences Naturelles. Vol. 50. ed. F. G.
Levrault. 1828. Apercu organographique sur le nombre deux. Mém. Mus.
d Hist. Nat. par les Prof. de cet establissement, 16: 296-344.
Uncer, FRANz. 1854. Beitrage zur Kenntniss der niedersten Algenformen, nebst
Versuchen ihre Entstehung betreffend. Denskr. Akad. Wiss. Wien, 7:
185-196.
Unctr, W. B. 1941. A new variety of Trachelomonas urceolata (Protozoa,
Mastigophora). Bull. Mt. Desert Isl. Biol. Lab., 1941: 15-17. 1941a, A
preliminary survey of the protozoa of Beaver Lake near Salsbury Cove,
Maine. Ibid., 1941: 17-18.
Vaucuer, J. P. 1803. Histoire des confervés d’eau douce. Geneva.
VELAsQuEZ, Grecoria T. 1939. On the viability of algae obtained from the
digestive tract of the gizzard shad, Dorosoma cepedianum (Le Sueur).
Amer. Mid]. Nat., 22: 376-412; Pls. 1-7. 1940.* A list of the filamentous
Myxophyceae from Michigan. Ibid., 23: 178-181.
Virieux, J. 1916. Recherches sur le plancton des lacs du Jura central. Ann.
Biol. Lacustre, 8: 5-192; Figs. 1-46.
ViscHER, W. 1920. Sur le polymorphisme de L’Ankistrodesmus Braunii (Nae-
geli) Collins. Zeit. f£. Hydrol., 1: 5-50.
Waern, M. 1938. Om Cladophora aegagropila, Nostoc pruniforme och andra
alger i Lilla Ullevifjirden, Malaren. Bot. Notiser, 1938: 128-142.
Wautstept, L. J. 1875. Monografi dfver Sveriges och Norges Characeer.
Christiania.
Waues, C. H. 1928. Dinoflagellates and Protozoa from British Columbia with
descriptions of new species. Mus. and Art Notes (Vancouver, B. C.), 3: 1-8.
1929. Alpine Rhizopoda and Peridiniidae from British Columbia. Ann.
Protist., Paris, 2: 179-183.
WaxsMAN, SELMAN A. 1941. Aquatic bacteria in relation to the cycle of
organic matter in lakes. In A Symposium on Hydrobiology. Madison.
Wa.uicu, G. C. 1877. Observations on the Coccosphere. Ann. and Mag. Nat.
Hist., 19( Ser. 4): 342-349.
[| 654 J
Wattrotu, F. W. 1815. Annus botanicus, sive supplementum tertium ad Curtii
Sprengelii floram Halensem. Halle. 1833. Flora cryptogamica germanicae.
Pars posterior. Niirnberg. 1833a. Compendium florae germanicae. IV.
Niirnberg.
Watton, L. B. 1915.+ A review of the described species of the order Eug-
lenoidina Bloch. Ohio State Univ. Bull., 19: 343-459; Pls. 12-26; Fig. 1.
1930. Studies concerning organisms occurring in water supplies with parti-
cular reference to those found in Ohio. Part. I. Ohio Biol. Surv. Bull.
5(No. 24): 1-86.
Waiz, J. 1866.+ Beitrag zur Morphologie und Systematik der Gattung Vau-
cheria DC. Jahrb. Wiss. Bot., 5: 127-160; Pls. 12-14.
Warp, H. B., and Wuirrte, G. C. 1918. Freshwater biology. 1111 pp.; Figs.
1-1547. New York.
Warminc, E. 1876. Om en Fircellet Gonium (Dujardins Tetramonas socialis).
Bot. Tids., 9(Ser. 3): 69-83.
WarTMANN, B., and ScHEenx, B. 1862. Schweizerische Kryptogamen. Exsic-
cate. Fasc. I. St. Gallen.
Watson, J. B., and TiLpEN, JosEPHINE E. 1930. The algal genus Schizomeris
and the occurrence of Schizomeris Leibleinii Kiitzing in Minnesota. Trans.
Amer. Microsc. Soc., 49: 160-167.
Weser, Rotanp. 1933. Beitrige zur Kenntnis der Gattung Calothrix. Arch. £
Protist., 79: 391-415.
We cu, Pau S. 1935. Limnology. New York. 1936.* Limnological investiga-
tion of a strongly basic bog lake surrounded by an extensive acid-forming
bog mat. Pap. Mich. Acad. Sci., Arts, and Letters, 21: 727-751. 1986a.* A
limnological study of a small Sphagnum-leather leaf—black spruce bog lake
with special reference to its plankton, Trans. Amer. Microsc. Soc., 55: 800-
312. 1938.+ A limnological study of a bog lake which has never developed
a marginal mat. Ibid., 57: 344-357. 1941. Dissolved oxygen in relation to
lake types. In A Symposium on Hydrobiology. Madison.
Wesensurc-Lunp, G. 1908. Plankton investigations of the Danish lakes.
General Part. The Baltic fresh-water plankton, its origin and variation.
Copenhagen.
West, G. S. 1899. The alga-flora of Cambridgeshire. Jour. Bot., 87: 49-58,
106-116, 216-225, 262-268, 291-299. 1902. On some algae from hot springs.
Ibid., 40: 241-248; Pl. 439. 1904. A treatise on the British freshwater algae.
372 pp.; Figs. 1-166. Cambridge. 1904a. West Indian freshwater algae.
Jour. Bot., 42: 281-294; Pl. 464. 1905. A comparative study of the dominant
phanerogamic and higher cryptogamic flora of aquatic habit in three lake
areas of Scotland. Proc. Roy. Soc. Edinburgh, 25(No. 11): 976-1023. 1907.
Report on the freshwater algae, including phytoplankton, of the Third Tan-
ganyika Expedition conducted by Dr. W. A. Cunnington, 1904-1905. Jour.
Linn. Soc. Bot., 38: 81-197; Pls. 1-8. 1908. Some critical green algae. Ibid.,
38: 279-289; Pls. 20,21. 1909. A biological investigation of the Peridineae
of Sutton Park, Warwickshire. New Phytol., 8: 181-196. 1909a. The algae
of the Yan Yean Reservoir, Victoria; a biological and ecological study. Jour.
Linn. Soc. Bot., 39: 1-88; Pls. 1-6; Figs. 1-10. 1912. Algological notes.—
X-XIII. Jour. Bot., 50; 321-331. 1914. A contribution to our knowledge of
the freshwater algae of Columbia. Mém. Soc. Neuchat. Sci. Nat., 5: 1013-
1051. 1915. Algological Notes XIV-XVII. Jour. Bot., 53: 73-84. 1916.+
Algae. Vol. I. Myxophyceae, Peridineae, Bacillariaceae, Chlorophyceae, to-
gether with a brief summary of the occurrence and distribution of fresh-
water algae. 475 pp.; Figs. 1-271. Cambridge.
[ 655 ]
West, G. S., and Frirscu, F. E. 1927.+ A treatise on the British fresh-water
algae. 534 pp.; Figs. 1-207. Cambridge.
West, W. 1891. Notes on Danish algae. Nuova Notarisia, 1891: 418-425.
1892. Algae of the English lake district. Jour. Roy. Microsc. Soc. London,
1892: 713-748; Pls. 9-10.
West, W., and West, G. S. 1894. New British freshwater algae. Jour. Roy.
Microsc. Soc. London, 1894: 1-17. 1895. A contribution to our knowledge
of the freshwater algae of Madagascar. Trans. Linn. Soc. Bot., 5(Ser. 2):
41-90. 1895a. New American algae. Jour. Bot., 33: 52. 1895b. On some fresh-
water algae from the West Indies. Jour. Linn. Soc. Bot., 30(1893-1895):
264-280. 1896. On some new and interesting fresh-water algae. Jour. Roy.
Microsc. Soc. London, 1896: 149-165. 1896a. Algae from Central Africa.
Jour. Bot., 34: 377-384. 1897, Welwitch’s African freshwater algae. Ibid.,
85: 1-7, 338-42, 77-89, 118-122, 172-188, 285-243, 264-272, 297-304.
1897a. A contribution to the freshwater algae of the south of England. Jour.
Roy. Microsc. Soc. London, 1897: 467-511. 1898. Notes on freshwater algae
of the West Indies. Jour. Linn. Soc. Bot., 34: 279-295. 1900. Notes on
freshwater algae. II. Jour. Bot., 38: 289-299. 1900-1901. The alga-flora of
Yorkshire; a complete account of the known fresh-water algae of the county.
Bot. Trans. York. Nat. Union, 5, Pt. 22: 5-22; Pt. 23: 53-100; Pt. 25(1901):
101-164; Pt. 27(1901): 165-239. 1901. Fresh-water Cyanophyceae. In J.
Schmidt, Flora of Koh Chang, Part 4. Bot. Tids., 24: 157-186. 1902. A
contribution to the freshwater algae of the north of Ireland. Trans. Roy.
Irish Acad., 32(B): 1-100. 1902a. A contribution to the freshwater algae of
Ceylon. Trans. Linn. Soc, Bot., 6(Ser. 2): 123-215. 1903. Notes on fresh-
water algae. III. Jour. Bot., 41: 33-41, 74-82; Pls. 446-448. 1903a. Scottish
fresh-water plankton—No., 1. Jour. Linn, Soc. Bot., 35: 519-556; Pls. 14-18.
1905. Freshwater algae from the Orkneys and Shetlands. Trans. Bot. Soc.
Edinburgh, 23: 3-41. 1905a. A further contribution to the freshwater plank-
ton of the Scottish Lochs. Trans. Roy. Soc. Edinburgh, 41, Pt. 3: 477-518;
Pls. 1-7. 1906. A comparative study of the plankton of some Irish lakes.
Trans. Roy. Irish Acad., 33(B): 77-116; Pls. 6-11. 1907. Freshwater algae
from Burma, including a few from Bengal and Madras. Ann. Roy. Bot.
Gard. Calcutta, 6(Pt. 2): 175-260; Pls. 10-16. 1909. The phytoplankton of
the English lake district. Naturalist, 1909: 115-193, 260-321; Pls. 5-7.
1912. On the periodicity of the phytoplankton of some British lakes. Jour
Linn. Soc. Bot., 40: 895-432; Pl. 19; Figs. 1-4.
Wue pen, R. M. 1939. Notes on New England algae I: Cyclonexis and Acti-
desmium. Rhodora, 41: 133-136; Figs. 1-7. 1941. Some observations on
freshwater algae of Florida. Jour. Elisha Mitchell Sci. Soc., 57: 261-271;
Pls. 5,6. 1942. Notes on New England algae. II. Some interesting New
Hampshire algae. Rhodora, 44: 175-187; Figs. 1-6. 1943. Notes on New
England algae. III. Some interesting algae from Maine. Farlowia, 1: 9-23;
Figs. 1-18.
ieeece Gro. C. 1927. The microscopy of drinking water. 586 pp.; Pls. 1-19.
4th ed. New York.
Wurerte, Geo. C., and Parker, H. N. 1902. On the amount of oxygen and
carbon dioxide in neutral waters and the effect of these gases upon the
occurrence of microscopic organisms. Trans. Amer. Microsc. Soc., 23: 108-144.
Wuurtrorp, L. A. 1936. New and little known algae from North Carolina. Jour.
Elisha Mitchell Sci. Soc., 52: 93-98; Pl. 12. 1938. A new green alga:
Oedocladium Lewisii. Bull. Torr. Bot. Club, 65: 23-26; Pl. 2. 1943. The
fresh-water algae of North Carolina. Jour. Elisha Mitchell Sci. Soc., 50:
131-170.
[ 656 |
Wuirney, L. W. 1937. Microstratification of the waters of inland lakes in
summer. Science, 85: 224—225.
Wuirtson, A. R., DUNNEWALD, T. J., and THompson, Carv. 1921. Soil survey
of northern Wisconsin. Wis. Geol. and Nat. Hist. Surv. Bull. 55(Soil Ser.,
No. 27). Madison.
Wuttson, A. R., Gers, W. J., and TostEerup, M. O, 1921. Soil survey of Wau-
paca County, Wisconsin. Wis. Geol. and Nat. Hist. Surv. Bull. 54—C (Soil
Ser., No. 25). Madison.
Wiese, A. H. 1930. Investigations on plankton production in fish ponds. Bull.
U. S. Bur. Fish., 46: 187-176. 1930a. Notes on the exposure of young fish
to varying concentrations of arsenic. Trans. Amer. Fish. Soc., 60: 270-280.
Wiese, A. H., RapvcuirFe, R., and Warp, Fern. 1929. The effects of various
fertilizers on plankton production. Trans. Amer. Fish. Soc., 59: 94—105.
Wute, N. 1879. Ferskvandsalger fra Novaja Semla samlede af Dr. F. Kjellman
paa Nordenskidlds Expedition. Oefv. Kong]. Sv. Vet.-Akad. Forhandl., 36
(No. 5): 13-74. 1881. Om Hvileceller hos Conferva (L) Wille. Ibid.,
38(No. 8): 3-26; Pls. 1,2. 1884. Bidrag til Sydamerikas Algflora I-III. Bih.
Kongl. Sv. Vet.-Akad. Handl., 8(No. 18): 1-64; Pls. 1-3. 1887. Algologische
Mittheilung. I. Ueber die Schwarmzellen und deren Copulation bei Trente-
pohlia Mart. Jahrb. Wiss. Bot., 18: 426-434; Pl. 16; Figs. 1-11. 1887a.
Ibid., IV. Ueber die Zelltheilung bei Oedogonium. Ibid., 18: 443-454; Pls.
16,17. 1887b. Ibid., VIII. Ueber die Gattung Gongrosira Kiitz. Ibid., 18:
484-491; 1 pl. 1897. Chlorophyceae. In A. Engler and K. Prantl, Die
Natiirlichen Pflanzenfamilien. Teil 1, Abt. 2. Leipzig. 1898. Beschreibung
einiger Planktonalgen aus norwegischen Siisswasserseen. Biol. Centralbl., 18:
302. 1899. New forms of green algae. Rhodora, 1: 149-150. 1900. Astero-
cytis ramosa (Thw.) Gobi. Nyt Mag. f. Natur., 38: 7-10; Pl. 1. 1900a.
Algologische Notizen. I-VI. Nyt Mag. f. Natur., 38: 1-27. 1901. Studien
iiber Chlorophyceen. I-VII. Videns. Skrift. i Christiania, I. Mat.-Nat. K1.,
1900(No. 6): 1-46. 190la. Algologische Notizen. VII-VIII. Nyt Mag. f.
Natur., 39: 1-22. 1902. In F. S. Collins, I. Holden, and W. A. Setchell. Phyco-
theca boreali-americana. 1908. Zur Entwicklungeschichte der Gattung Oocystis.
Ber. d. Deutsch. Bot. Ges., 26A: 812-822; Pl. 15. 1909. Ueber Wittrockiella
nov. gen. Nyt Mag. f. Natur., 47: 5-21; Pls. 1-4. 1910. Algologische Notizen.
XVI-XXI. Ibid., 48: 281-306; Pls. 1, 2. 1911.+ Conjugatae, Chlorophyceae,
Characeae. In A. Engler and K. Prantl, Die Natiirlichen Pflanzenfamilien.
Teil 1, Abt. 2: 1-136; Figs. 1-70. Leipzig. 1912. Algologische Notizen.
XXII-XXIV. Ueber eine neue epiphytische Art von Lyngbya. Nyt Mag.
f. Natur., 51: 1-26. 1914. Botanische und zoologische ergebnisse einer Wis-
senschaftlichen Forschungsreise nach den Samoainseln, dem Nauguinea-
Archipel und den Salomonsinseln von Marz bis Dezember 1905. Denks. d.
Mat.-Nat. KI. d. Kaiser, Akad. Wiss., 91: 1-22; Pls. 1-3 (reprint). 1918.
Algologische Notizen XXV-XXIX. Nyt Mag. f. Natur., 56: 1-60; Pls. 1, 2.
1925. Vorarbeiten zu einer Monographie der Chroococcaceen. Ibid., 62:
170-209.
WriuiaMson, BEN L., GREENBANK, JOHN, Mutter, E. P., et al. 1938—1939*
Investigation of the pollution of the Fox and East Rivers and of Green Bay
in the vicinity of the City of Green Bay. Mimeogr. by Wisconsin State Com-
mittee on Water Pollution, the State Board of Health and Green Bay
Metropolitan Sewerage District. *
Witson, Ira T., and OppyKe, Davm F. 1941. The distribution of the chemical
constituents in the accumulated sediment of Tippecanoe Lake. Investigation
Indiana Lakes and Streams, 2: 16-43. Indianapolis.
Witson, L. R. 1987. A quantitative and ecological study of the larger aquatic
[ 657 ]
plants of Sweeney Lake, Oneida County, Wisconsin. Bull. Torr. Bot. Club,
64: 199-208. 1941.* The larger aquatic vegetation of Trout Lake, Vilas
County, Wisconsin. Trans. Wis. Acad. Sci., Arts and Letters, 33: 135-146.
Wimmer, E. J. 1929." A study of two limestone quarry pools, Trans. Wis.
Acad. Sci., Arts, and Letters, 24: 363-399.
Wistoucn, S. M. 1911. Ueber eine durch Oscillaria Agardhii hervorgerfene
wasserbliite, sowie iiber Spirulina flavovirens (nova sp.) mihi. Bull. Jard.
Imp. Bot. Pierre le Grand, 11(No. 6): 155-161. 1914. Sur les Chrysomona-
dines des environs de Petrograd. Jour. Microbiol. Petrograd, 1: 251-278.
Wirtrock, V. B. 1867. Algologiska Studier, I-II. Upsala. 1868. Bidrag till
kannedomen om Sveriges Zygnemacéer och Mesocarpacéer. Bot. Notiser,
1868: 187-190. 1871. Dispositio Oedogoniacearum suecicarum. Oefv. Kong}.
Sv. Vet.-Akad. Forhandl., 27, No. 3(1870): 119-144. 187la. Beitrag zur
Kenntnis der Zygnemaceen und Mesocarpeen. Hedwigia, 10: 88. 1872. Om
Gotlands och Oelands Sotvattens-alger. Bih. Kongl. Sv. Vet.-Akad. Handl.,
1(No. 1): 1-72. 1872a. Oedogoniaceae novae, in Suecia lectae, quas des-
cripsit. Bot. Notiser, 1872: 1-8. 1875. Prodromus monographiae Oedogonie-
arum. Nova Acta Soc. Sci. Upsala, 9(1874): 1-64; Pl. 1. 1876. In C.
F. O. Nordstedt and V. Wittrock. 1876. II. Oedogonieae De Bar., Pringsh.
Oefv. Kongl. Sv. Vet.-Akad. Forhandl., 33(No. 6): 44-56. 1877. On the
development and systematik arrangement of the Pithophoraceae, a new
order of algae. Ibid., Vol. Extra Ordine, Editum, 1877: 1-80; Pls. 1-6.
1878. Oedogonieae Americanae, hucusque cognitae, quas enumeravit. Bot.
Notiser, 1878: 133-145, 1878a. On the spore-formation of the Mesocarpeae
and especially of the new genus Gonatonema. Bih. Kongl. Sv. Vet.-Akad.
Handl., 5(No. 5): 1-18; Pl. 1. 1880. Points-fortekning 6fver Skandinaviens
vaxter, Part 4. Lund. 1882. In V. B. Wittrock and C. F. Nordstedt, Algae
aquae dulcis exsiccatae. Bot. Notiser, 1882: 51-61. 1886. Om Bu..“‘clearia,
ett nytt confervace-sligte. Bih. Kongl. Sv. Vet.-Akad. Handl., 12, Atd. 3,
No. I: 3-10; 1 pl.
Wirrrock, V. B., and Creve, P. T. 1875. In V. B. Wittrock, Prodromus mono-
graphiae Oedogoniearum. Nova. Acta Soc. Sci. Upsala, 9(1874): 1-64; Pl. 1.
Wirtrock, V. B., and LunpEtt, P. M. 1871. In V. B. Wittrock, Dispositio
Oedogoniacearum suecicarum. Oefv. Kongl. Sv. Vet.-Akad. Forhandl., 27
(1870): 119-144.
Wirrrock, V. B., and Norpstept, C. F. O. 1877-1903. Algae aquae dulcis
exsiccatae (Nos. 1-1612). 1877. Algae aquae dulcis exsiccatae (Fasc. 1
and 2, Nos. 1-100). Bot. Notiser, 1877: 21-26. 1878. Algae aquae dulcis
exsiccatae, etc. (Fasc. 3, Nos. 101-150; Fasc. 4, Nos. 151-200). Ibid., 1878:
67-73. 1879. Algae aquae dulcis exsiccatae (Nos. 201-298). Ibid., 1879:
20-27. 1882. Algae exsiccatae (Nos. 401-500). Ibid., 1882: 51-61. 1884.
Algae exsiccatae (Nos. 601-698). Ibid., 1884: 121-128. 1886. Algae exsic-
catae (Nos. 701-850). Ibid., 1886: 130-189. 1893. Algae exsiccatae (Nos.
1001-1200). Ibid., 1893: 185-200.
Wo te, Francis. 1887.* Freshwater algae of the United States. 364 pp. Pls.
1-210. 2 vols. Bethlehem, Pa.
Wozoszynska, J. 1914. In B. Schroeder, Zellpflanzen Oestafricas, gesammelt
auf der Akademischen Studienfahrt 1910. V. Studien iiber das Phytoplankton
des Viktoriasees. Hedwigia, 55: 184-223; Pls. 2-8. 1916. Polonische Siis-
swasser-peridineen. Bull. Inter. Acad. Sci. Cracovie, Math. et Nat. Cl,
Reihe B: Biol. Wissen., No. 8-10(1915): 260-285; Pls. 10-14. 1918. Neue
Peridineen-Arten, nebst Bemerkungen iiber den Bau der Hiille bei Gymno-
und Glenodinium. Ibid., No. 4-6(1917): 114-122; Pls. 11-13. 1917a.
[ 658 ]
Beitrag zur Kenntnis der Algenflora Litauens. Ibid., No. 4-6(1917): 123-
130. 1919. Die Algen der Tatraseen und Tiimpel. I. Ibid. (1918): 196-
200. 1925. Beitrage zur Kenntnis der Siisswasser-Dinoflagellaten Polens.
Polskie Towarzystwo botaniczne (Acta Soc. Bot. Poloniae), 3: 46-69; Figs.
1-7. 1930. Beitrige zur Kenntnis des Phytoplanktons Tropischer Seen. Arch.
d’Hydrobiol. u. d'Ichty., 5: 159-160; Figs. 1-6. 1936. Die Algen der
Tatraseen und Tiimpel. III. Peridineen im Winterplankton einiger Tatraseen.
Ibid., 10: 188-196; Pl. 9.
Woop, H. C. 1867. On Oedogonium Huntii. Proc. Amer. Philos. Soc., 10:
333-335. 1869.* Prodromus of a study of the fresh water algae of eastern
North America. Ibid., 11: 119-145. 1874.* A contribution to the history of
the fresh-water algae of North America. Smiths. Contrib. Knowledge, 19
(No. 241): 1-262; Pls. 1-21.
Woop, R. D. 1947. Characeae of the Put-in-Bay region of Lake Erie (Ohio).
Ohio Jour. Sci., 47: 240-258; Pls. 1-3. 1949. The Characeae of the Woods
Hole region, Massachusetts. Biol. Bull., 96( No. 2): 179-203; Pls. 1-4.
Woops, A. F. 1894. Coleochaetaceae, Characeae. Flora of Nebraska, Part II.
Lincoln, Nebr.
Woronicuin, N. N. 1923. Algae nonnullae novae e Caucaso. I. Not. Syst. Inst.
Crypt. Horti Bot. Petropol., 2(No. 7): 97-100. 1923a. Ibid. II. Ibid., 2,
(No. 8): 113-116. Ibid. Ill. Ibid., 2(No. 9): 140-142. 1923b. Ibid. IV.
Ibid., 2(No. 12): 192. 1924 Ibid. V. Ibid., 3(No. 6): 84-88. 1924a. Ibid.
VI. Ibid., 83(No. 7): 102-106. 1924b. Matériaux pour la flore algologique
des eaux douces du Caucase. V. Chlorophyceae. Zeit. Russ. Bot. Ges., 8
(1923): 78-86. 1925. Materialien zur Flora des Siisswasseralgen des Kau-
kasus. Trav. Stat. Biol. du Caucas. du Nord, 1(1925): 1-7. 1925a. Beitrage
zur Kenntnis der Siisswasseralgen des Kaukasus, II, III. Arch. Russ. Protist.,
4, No. 3/4: 199-216. 1930. [Algen des Polar- und des Nord-Urals]. Trav.
Soc. Nat. Leningrad Soc. Bot., 60(No. 3): 3-80.
Worontn, M. 1869. Beitrag zur Kenntniss der Vaucherien. Bot. Zeit., OT:
137-144, 153-162; Pls. 1, 2.
Wortuincton, E. B. 1939. Freshwater biology and its applications: Intro-
duction. Ann. Appl. Biol., 26: 165-167.
YamManoucul, S. 1913. Hydrodictyon africanum, a new species. Bot. Gaz., 55:
74-79; Figs. 1-6.
Younc, O. W. 1945.* A limnological investigation of periphyton in Douglas
Lake, Michigan. Trans. Amer. Microsc. Soc., 64: 1-20.
ZacHarias, Otro. 1897. Biologische Beobachtungen an den Versuchsteichea
des Schles. Fischereivereins zu Trachenberg. Forsch. Biol. Stat. z. Plon, 5:
10-28. 1898. Untersuchungen iiber das Plankton der Teichgewisser. [bid.,
6: 89-193; Pl. 4. 1899. Zur Kenntnis der Plankton siichsischer Fischteiche.
Ibid., 7: 78-95. 1903. Zur Kenntnis der niedern Flora und Fauna holsteinis-
cher Moorsiimpfe. Ibid., 10: 223-289. 1903a. Drei neue Pflanzenflagellaten
des Siisswassers. Ibid., 10: 290-303. 1907. Planktonalgen als Molluskennah-
rung. Arch. f. Hydrobiol. u. Planktonk., 2: 358-361. 1911. Das Siisswasser-
Plankton. Einfiihrung in die freischwebende Organismenwelt unserer teiche,
Fliisse und Seebecken. Leipzig.
ZaLEssky, M. D. 1926. Sur les nouvelles algues découvertes dans le saprope-
logéne du Lac Beloe et sur une algue sapropélogéne Botryococcus Braunii
Kitzing. Rev. Gen. Bot., 38: 31-42.
ZaNaARDINI, G. 1858. Plantarum in mari rubro hucusque collectarum enume-
ratio. Mem. Ist. Veneto, 7: 209-309; Pls. 3-14.
ZANEVELD, J. S. 1939. Nitella madagascarensis, nov. spec., with notes on the
Charophyta of Madagascar. Blumea, 3: 372-387.
[ 659 ]
ZeEDERBAUER, E. 1904. Geschlechtliche und ungeschlechtliche Fortpflanzung
von Ceratium hirundinella. Ber. d. Deutsch. Bot. Ges., 22: 1-8.
ZELLER, G. H. von. 1873. Algae collected by Mrs. S. Kurz in Arracan and
British Burma. Jour. Asiatic Soc. Bengal, 42: 175-193.
ZIMMER, CarL. 1899. Das Plankton des Oderstromes. A. Das tierische Plankton
der Oder. Forsch. Biol. Stat. z. Plon, 7: 1-14.
ZIMMERMANN, W. 1927. Ueber Algenbestinde aus der Tiefenzone des Bodensees.
Zur Oekologie und Soziologie der Tiefseepflanzen. Zeitsch. f. Bot., 20: 1-35;
Pls. 1, 2; Figs. 1-5.
ZoBELL, CLaupE E. 1940. Some factors which influence oxygen consumption
by bacteria in lake water. Biol. Bull., 78: 388-402.
Zuxat, H. 1894. Neue Beobachtungen uber einige Cyanophyceen. Ber. d.
Deutsch. Bot. Ges., 12: 256-266.
References for Desmids and Diatoms
Fritsch, F. E. 1935. Structure and Reproduction of the Algae. Vol. I. 791 pp.
Cambridge.
Hustedt, F. 1929. Die Kieselalgen. In: Rabenhorst, L. Kryptogamen-Flora
Deutschlands, Osterreich, und der Schweiz. Bd. VII.
Irénée-Marie, Fr. 1939. Flore Desmidiale de la Region de Montréal. 547 pp.
Laprairie, Canada.
Krieger, W. 1937. Die Desmidiaceen Europas mit Berucksichtigung der ausser-
europdischen Arten. In: Rabenhorst, L. Kryptogamen-Flora Deutschlands,
Osterreich und der Schweiz. Bd. XIII.
Prescott, G. W. 1964. How to Know the Fresh-Water Algae. 272 pp. Wm.
C. Brown Co.
Smith, G. M. 1924. Phytoplankton of the Inland Lakes of Wisconsin. Part II.
Desmidiaceae. Wisconsin Geol. & Nat. Hist. Surv., Bull. 57 (II). 227 pp.
Madison.
Van Heurck, Henri. 1896. A Treatise on the Diatomaceae. 558 pp. William
Wesly & Son, London.
West, W. and West, G. S. 1904-1912. A Monograph of the British Desmidia-
ceae. Vols. I-IV. and Carter, Nellie. 1924. Ibid. Vol. V. Ray Society, London.
[ 660 ]
PLATES
Figs. 1, 2.
Fign3:
Fig. 4.
Fig. 5.
Figs. 6, 7.
Figs. 8, 9.
Figs. 10, 11.
Fig. 12.
Figs. 13, 14.
Figs. 15, 16.
Figs. 17-19.
Fig. 20.
Fig. 21.
Fig. 22.
Fig. 23.
Figs. 24-26.
iPreAmeel
Pyramimonas tetrarhynchus Schmarda, x 750 (after
Smith )
Chlamydomonas angulosa Dill, x 750
Chlamydomonas Cienkowskii Schmidle, x 750
Chlamydomonas Dinobryoni G. M. Smith, x 1000
(redrawn from Smith )
Chlamydomonas epiphytica G. M. Smith, x 750
(redrawn from Smith )
Chlamydomonas globosa Snow, x 1000 (8 after Smith)
Chlamydomonas polypyrenoideum Prescott, x 1000
Chlamydomonas pseudopertyi Pascher, x 500
Chlamydomonas Snowii Printz, x 1000 (redrawn
from Smith )
Chlamydomonas sphagnicola Fritsch & Takeda, x 1000
Carteria Klebsii (Dang.) Dill, x 1000 (redrawn
from Smith
Carteria cordiformis (Carter ) Diesing, x 1000
(redrawn from Smith )
Gonium pectorale Mueller, x 500
Gonium sociale (Duj.) Warming, x 750
Pandorina morum (Muell.) Bory, x 500
Eudorina elegans Ehrenberg: 24 and 25, x 440; 26,
formation of daughter colonies, x 440
[ 662 ]
Fig. 1.
Fig. 2
Fig. 3.
Fig. 4.
Fig. 5.
PLATE 2
Pleodorina californica Shaw, x 250
Haematococcus lacustris (Girod.) Rostaf., x 1000
Pleodorina illinoisensis Kofoid, x 450
Volvox aureus Ehrenberg, x 266 (redrawn from Smith )
Volvox globator Linnaeus, x 266 (after Smith)
[ 664 ]
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Fig. 2.
Figs. 3—5
Figs. 6, 7.
Figs. 8, 9.
Figs. 10, 11.
Fig. 12.
Figs. 18, 14.
Fig. 15.
Fig. 16.
Rigel,
PLATE 3
Spondylomorum quaternarium Ehrenberg, x 440 (af-
ter Stickney )
Spondylomorum quaternarium Ehrenberg: single cell,
x 500 (after Jacobsen, ex Smith)
Haematococcus lacustris (Girod.) Rostaf. 3, swim-
ming cell; 4 and 5, encysted cells, x 750
Sphaerocystis Schroeteri Chodat, x 500
Palmella mucosa Kuetzing: 8, habit of colony, x 114;
9, portion of colony, x 440
Gloeocystis planctonica (West & West) Lemmermann,
x 500
Volvox tertius A. Meyer, x 266 (redrawn from Smith )
Elakatothrix gelatinosa Wille: 13, x 1000; 14, x 500
(after Smith)
Gloeocystis vesiculosa Naegeli, x 500
Gloeocystis gigas (Kuetz.) Lagerheim, x 1000
Gloeocystis ampla (Kuetz.) Lagerheim x 440
[ 666 |
2® EPO, GPE
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PLATE 4
Figs. 1, 2. Elakatothrix viridis (Snow) Printz: 1, x about 620 (re-
drawn from Smith); 2, x 440
Figs. 3, 4. Palmodictyon varium (Naeg.) Lemmermann, x 500
Figs. 5, 6. Palmodictyon viride Kuetzing, x 500
Figs. 7-9. Stylosphaeridium stipitatum (Bachm.) Geitler & Gi-
mesi: 7, x 500; 8 and 9, single cells, x 1000
Fig. 10. Asterococcus superbus (Cienk.) Scherffel, x 440
Big. 1, Asterococcus limneticus G. M. Smith, x 500
Figs. 12-14. Schizochlamys compacta Prescott, x 500
Fig. 15. Schizochlamys gelatinosa A. Braun, x 500
[| 668 ]
Figs, 1, 2.
Figs. 3, 4.
Fig. 5.
Fig. 6.
Figs. 7, 8.
Fig. 9.
Fig. 10.
Fig, AT:
PLATE 5
Tetraspora cylindrica (Wahl.) C. A. Agardh: 1, habit x 1;
2, cell arrangement, x 220
Tetraspora gelatinosa (Vauch.) Desvaux: 3, habit of
young colony, x 5; 4, habit of older colony, x 1
Uronema elongatum Hodgetts, x 440
Tetraspora lamellosa Prescott, x 500
Apiocystis Brauniana Naegeli: 7, colony, x 440; 8, single
cell, x 1500
Tetraspora lubrica (Roth) C. A. Agardh: portion of old
thallus, x 1
Apiocystis Brauniana Naegeli, « 300
Tetraspora lacustris Lemmermann, x 440
[ 670 ]
PLATE 6
Big. Ulothrix aequalis Kuetzing, « 500
Bigs 2; Ulothrix cylindricum Prescott, x 500
Fig. 3. Ulothrix subtilissima Rabenhorst, « 750
Fig. 4. Hormidium Klebsii G. M. Smith, « 500
Fig. 5. Stichococcus bacillaris Naegeli, x 1500
Fig. 6. Stichococcus scopulinus Hazen, x 750
Figs. 7,8. | Stichococcus subtilis (Kuetz.) Klercher, x 750
Figs.9,10. Geminella crenulatocollis Prescott, x 750
Fig. 11. Ulothrix subconstricta G. S. West, x 750 (after Smith)
Fig. 12. Ulothrix tenerrima Kuetzing, 500
Fig. 13. Ulothrix variabilis Kuetzing, « 750
Fig. 14. Ulothrix zonata (Weber & Mohr) Kuetzing, x 750
Fig. 15. Geminella interrupta (Turp.) Lagerheim, x 500
Fig. 16. Geminella mutabilis (de Bréb.) Wille, x 440
Big 7, Geminella minor (Naeg.) Heering, x 440
[ 672 ]
PLATE 7
Figs. 1, 2. Hormidiopsis ellipsoideum Prescott, x 750
Figs. 3-5. Radiofilum irregulare (Wille) Brunnthaler: 3, x 1000;
4, x 750; 5, x 440
Fig. 6. Radiofilum conjunctivum Schmidle, x 750
Figs. 7-9. Binuclearia tatrana Wittrock, x 440
Fig. 10. Radiofilum flavescens G. S. West, x 590
Figs. 11-13. Schizomeris Leibleinii Kuetzing: 11, x 220; 12, x 500;
13, x 500
[ 674 ]
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PLATE 8
Fig. 1. Microspora crassior (Hansg.) Hazen, x 750
Fig. 2. Microspora Loefgrenii (Nordst.) Lagerheim, x 750
Fig. 3. Microspora pachyderma (Wille) Lagerheim, x 750
Fig. 4. Microspora floccosa (Vauch.) Thuret, x 750
Fig. 5. Microspora Willeana Lagerheim, x 1000
Figs. 6,7. Microspora stagnorum (Kuetz.) Lagerheim: 6, x 1125;
7, x 750
Fig. 8. Microspora amoena (Kuetz.) Lagerheim, x 660
Fig. 9. Microspora tumidula Hazen, x 1125
[ 676 ]
)
Jee ee
PLATE 9
Figs. 1,2. Cylindrocapsa geminella var. minor Hansgirg, x 750
Figs. 3,4. Cylindrocapsa geminella Wolle, oogonia: 3, x 750; 4, x
1500
Figs. 5,6. Cylindrocapsa conferta W. West, x 750
Figs. 7,8. Stigeoclonium nanum Kuetzing, x 750
Fig. 9. Stigeoclonium polymorphum (Franke) Heering, x 750
Fig. 10. Protoderma viride Kuetzing, x 750
[ 678 |
PLATE 10
Figs. 1,2. Stigeoclonium lubricum (Dillw.) Kuetzing, x 440
Figs. 3,4. Stigeoclonium subsecundum Kuetzing: 3, x 500; 4, x 440
Figs.5-7. Protococcus viridis C. A. Agardh, x 1000
[ 680 ]
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~ Figs. 1,2. Stigeoclonium flagelliferum Kuetzing, x 440
Fig. 3. Stigeoclonium stagnatile (Hazen) Collins, x 440
Fig. 4. Microthamnion Kuetzingianum Naegeli, x 440
Figs. 5,6. Microthamnion strictissimum Rabenhorst: 5, x 1000; 6,
base of plant, x 1000
[ 682 ]
PLATE 12
Figs. 1-4. Stigeoclonium pachydermum Prescott: 1, x 100; 2, x
500; 3 and 4, x 250
Figs. 5-8. Sphaeroplea annulina (Roth) C. A. Agardh: 5, portion
of vegetative cell, x 650; 6 and 7, germlings, x 325; 8,
portion of oogonial cell, x 650 (after Smith, courtesy
McGraw-Hill Co. )
Figs.9,10. Stigeoclonium pachydermum Prescott: forms of branch-
es, x 250
[ 684 ]
Ze fF S=
Bie
Figs. 2, 3.
Figs. 4, 5.
Figs. 6, 7.
PLATE 13
Stigeoclonium attenuatum (Hazen) Collins, x 750
Chaetophora pisiformis (Roth) C. A. Agardh: 2, habit,
x 2; 3, portion of thallus, x 500
Chaetophora attenuata Hazen: 4, x 440; 5, tip of branch,
x 750
Chaetonema irregulare Nowakowski: 6, filament with
oogonium, x 500; 7, sporangia, x 500
[ 686 ]
Figs. 1, 2.
Figs. 3, 4.
Fig. 5.
Figs. 6, 7.
Fig. 8.
Fig. 9.
Fig. 10.
Fig. 11.
PLATE 14
Chaetophora incrassata (Huds.) Hazen: 1, habit, x 1%;
2, habit of branching in main axis, x 225
Chaetophora elegans (Roth) C. A. Agardh: 3, habit, x
1; 4, x 825
Chaetosphaeridium Pringsheimii Klebahn, x about 1000
(redrawn after Klebahn, ex Collins )
Chaetosphaeridium globosum (Nordst.) Klebahn, x 750
Chaetosphaeridium ovalis G. M. Smith, x about 1000
(after Smith )
Entocladia polymorpha (G.S. West) G. M. Smith, x 440
Protoderma viride Kuetzing, x 750
Chaetophora incrassata (Huds.) Hazen: tip of branch,
x 500
[ 688 ]
)
SU
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i
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A
Fig. 1
Figs. 2, 3.
Fig. 4.
Fig. 5.
Fig. 6.
Prates5
Draparnaldia acuta (C. A. Ag.) Kuetzing: portion of
main filament, x 75
Draparnaldia platyzonata Hazen: 2, portion of main fila-
ment, x 150; 3, x 350
Draparnaldia plumosa (Vauch.) C. A. Agardh: portion
of main filament, x 165
Draparnaldia glomerata (Vauch.) C. A. Agardh: portion
of main filament, x 150
Pseudulvella americana (Snow) Wille: portion of disc-
like thallus, x 440
[ 690 |
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Pirate 16
Figs. 1-5. Draparnaldia Judayi Prescott: 1, portion of main axis
showing sparsely branched fascicles; 2-4, forms of
setae, some of which replace lateral branches of main
filament; 5, whorled arrangement of fascicles; all x 500
Fig. 6. Chaetopeltis orbicularis Berthold: habit on filamentous
alga, x 440
[ 692 ]
Fig. 1.
Figs. 2, 3.
Fig. 4.
Figs. 5-7.
Figs. 8, 9.
PLATE 17
Aphanochaete polychaete (Hansg.) Fritsch, x 500 (re-
drawn from West and Fritsch, courtesy of the Mac-
millan Publishing Company )
Aphanochaete repens A. Braun, x 440
Aphanochaete vermiculoides Wolle, x 750
Coleochaete divergens Pringsheim: 5 and 6, antheridia,
x 150; 7, oogonium, x 220
Coleochaete irregularis Pringsheim: 8, antheridia, x 440;
9, oogonium, x 220
[ 694 ]
PuatTeE 18
Figs. 1, 2. Coleochaete Nitellarum Jost: 1, habit on Nitella; 2,
oogonium, x 440
Figs. 3-5. Coleochaete orbicularis Pringsheim: 3 and 4, x 440;
5, habit on grass, x about 20
Fig. 6. Coleochaete soluta (de Bréb.) Pringsheim, x 500
Figs. 7, 8. Coleochaete pulvinata A. Braun, x 220
Fig. 9. Coleochaete scutata de Brébisson, x 75
Figs. 10,11. Coleochaete soluta (de Bréb.) Pringsheim: oogonia,
x 100
[ 696 ]
(i
N\A
PLATE 19
Figs.1,2. | Dicranochaete reniformis Hieronymus, x 1000
Fig. 3. Gongrosira Debaryana Rabenhorst, x 500
Figs. 4-8. | Trentepohlia Iolithus (L.) Wallroth: 4-5, filaments, x
125; 6 and 7, tips of branches and sporangia, x 500; 8,
filaments, x 125
Figs. 9-11. Cladophora crispata (Roth) Kuetzing: 9 and 10, x 200;
11, habit of branching (diagram)
[ 698 ]
PuAaTE 20
Figs. 1-6. Cladophora fracta (Dillw.) Kuetzing: various expres-
sions of the filaments; 1, habit of branching (diagram);
2 and 3, x 200; 4, x 100; 5, branch origin, showing
lamellations of wall, x 250; 6, old, ‘winter’ stage, x 200
Fig. 7. Cladophora fracta var. lacustris (Kuetz. ) Brand, x 500
Figs. 8,9. Cladophora glomerata (L.) Kuetzing: 8, portion of main
filament, x 75; 9, habit of branching, x 350
[ 700 ]
Figs. 1, 2.
Fig. 3.
Figs. 4, 5.
Figs. 6-8.
PLATE 21
Cladophora glomerata (L.) Kuetzing: 1, x 37%; 2, x
225 (redrawn from Smith)
Cladophora glomerata fa. Kuetzingianum (Grunow)
Heering, x 150
Cladophora insignis (C. A. Ag.) Kuetzing, x 225
Cladophora oligoclona Kuetzing: 6, x 100; 7, habit of
branching; 8, portion of main filament, x 100
[ 702 ]
PLATE 22
Figs. 1-4. Cladophora profunda var. Nordstedtiana Brand, x 100
Figs. 5,6. Pithophora Mooreana Collins, x 60
Figs. 7-10. Pithophora oedogonia (Mont.) Wittrock: 7, x 25; 8, x
100; 9, x 30; 10, portion of cell showing chloroplasts,
4125
[ 704 ]
\
\ /
Fig. 1.
Fig. o:
Fig. 3.
Figs. 4, 5.
Figs. 6, 7.
Figs. 8-12.
PLATE 23
?Rhizoclonium crassipellitum West & West fa., x 150
Rhizoclonium fontanum Kuetzing, x 440
Rhizoclonium heiroglyphicum (C. A. Ag.) Kuetzing,
x 150
Rhizoclonium Hookeri Kuetzing: 4, large form, x 150;
5x15
Rhizoclonium Hookeri Kuetzing, drawn from an her-
barium specimen: 6, x 100; 7, x 75
Basicladia chelonum (Collins) Hoffmann & Tilden:
9-11 (redrawn from Smith, courtesy McGraw-Hill
Co.), x 125; 12, enlarged cells in upper limits of fila-
ment showing papilla-like pores in sporangia (from
specimens collected in Michigan ), x 100
[ 706 ]
Fig. 1.
Figs. 2, 3.
Fig. 4.
Figs. 5, 6.
Biggie
Fig. 8.
Fig. 9.
PLATE 24
Bulbochaete hiloensis (Nordst.) Tiffany, x about 355
(redrawn from Tiffany )
Oedogonium verrucosum Hallas, x about 285 (redrawn
from Hallas, ex Tiffany
Oedogonium hispidum Nordstedt, x 300
Pithophora varia Wille, x 145
Bulbochaete obliqua Lundell, x 255
Bulbochaete valida Wittrock, « 290
Geminella ordinata (West & West) Heering, x 500
[ 708 ]
Bigs: 12.
Fig. 3.
Fig. 4.
Fig. 5.
FIGS G7.
Fig. 8.
PLATE 25
Bulbochaete alabamensis Transeau & Brown, x 290
Bulbochaete borealis Wittrock, x 590
Bulbochaete angulosa Wittrock & Lundell, x 590
Bulbochaete congener Hirn, x 590
Bulbochaete dispar Wittrock, x 300
Bulbochaete crassa Pringsheim, x 590
[710 ]
Fig. 1.
Fig. 2:
Fig. 3.
Figs. 4-6.
Fig, 7.
Fig. 8.
Fig. 9.
PLATE 26
Bulbochaete gigantea Pringsheim, x 500
Bulbochaete Furberae Collins, x 590
Bulbochaete elatior Pringsheim, x 590
Bulbochaete insignis Pringsheim: 4, x 590; 5 and 6, x 300
Bulbochaete minor A. Braun, x 590
Bulbochaete intermedia var. depressa Wittrock, x 500
Bulbochaete intermedia Debary, x 590
[ 712 ]
Figs. 1, 2.
Fig. 3.
Figs. 4, 5.
Fig. 6.
Figs. 7, 8.
Figs. 9, 10.
Pare. 27
Bulbochaete mirabilis Wittrock, x 500
Bulbochaete Nordstedtii Wittrock, x 590
Bulbochaete polyandria Cleve: 4, x 590; 5, androspo-
rangia, x 590
Bulbochaete praereticulata Jao, x 330
Bulbochaete pygmaea Pringsheim: 7, x 590; 8, x 625
Bulbochaete rectangularis Wittrock: 9, x 312; 10, x 590
[714 ]
PLATE 28
Figs. 1, 2. Bulbochaete regalis (Wittr.) Tiffany, x 300
Figs. 3. 4. Bulbochaete repanda Wittrock: 3, x 312; 4, x 590
Fig. 5. Bulbochaete reticulata Nordstedt, x 500
Fig. 6. Bulbochaete scrobiculata ( Tiff.) Tiffany, x 590
Figs. 7-9. Bulbochaete varians Wittrock: 7 and 8, x 590; 9, x 312
Figs. 10,11. Bulbochaete setigera (Roth) C. A. Agardh: 10, x 500;
11, x 1600
Fig. 12. Bulbochaete sessilis Wittrock, x 440
[ 716 }
PLATE 29
Figs. 1, 2. Oedogonium angustum (Hirn) Tiffany, x 312
Figs. 3, 4. Oedogonium anomalum Hin: 3, x 180; 4, x 375
Figs. 5, 6. Oedogonium capilliforme var. australe Wittrock, x 375
Figs. 7, 8. Oedogonium cardiacum (Hass.) Wittrock: 7, x 220;
8, x 440
Figs.9-11. Oedogonium diversum (Hirn) Tiffany, x 250
Figs. 12-14. Oedogonium gracilius (Wittr.) Tiffany: 12, x 625; 18
and 14, x 825
Figs. 15-17. Oedogonium grande Kuetzing, x 275
Fig. 18. Oedogonium grande var. aequatoriale Wittrock, x 300
[718 ]
Figs, 1, 2:
Figs. 3, 4.
Figs. 5, 6.
Hig: 7.
Figs. 8-10.
Figs. 11, 12.
Figs. 13-15.
PLATE 30
Oedogonium australe (G. S. West) Tiffany, x 500
Oedogonium giganteum Kuetzing: 3, x 220; 4, x 590
Oedogonium Boscii (Le Cl.) Wittrock, x 285
Oedogonium crenulatocostatum Wittrock, x 590
Oedogonium Kjellmanii var. granulosa Prescott: 8, x
285; 9, x 440; 10, x 285
Oedogonium exocostatum Tiffany: 11, x 500; 12, x 275
Oedogonium crenulatocostatum var. cylindricum
(Hirn) Tiffany: 13, x 275; 14, x 590; 15, x 275
[ 720 ]
PLATE 31
Figs. 1-3. Oedogonium globosum Nordstedt: 1, x 590; 2 and 3,
x 800
Fig. 4. Oedogonium Hirnii Gutwinski, « 590
Figs. 5, 6. Oedogonium intermedium Wittrock: 5, x 270; 6, x 590
Figs. 7,7a. | Oedogonium oviforme (Lewin) Hirn, x 590
Figs. 8, 9. Oedogonium areolatum Lagerheim: 8, x 500; 9, x 275
Figs. 10,11. Oedogonium argenteum Hin: 10, x 600; 11, x 590
[ 722 ]
Neier oo 82 Fo.
y99 S000 00 Poe
PLATE 32
Figs. 1,2. Oedogonium Landsboroughii (Hass.) Wittrock: 1, x
Tis 2X 150
Figs. 3,4. Oedogonium plagiostomum Wittrock: 3, x 600; 4, x 300
Figs. 5,6. Oedogonium rivulare (Le Cl.) A. Braun: 5, x 250; 6, x
125
Figs. 7-9. Oedogonium sociale Wittrock: 7 and 8, x 275; 9, x 590
Fig.10._ | Oedogonium varians Wittrock & Lundell, x 600
Fig.11. | Oedogonium tyrolicum Wittrock, = 500
Fig 2, Oedogonium fennicum ( Tiff.) Tiffany, x 500
Fig.13. | Oedogonium fragile Wittrock, x 590
[ 724 ]
Figs. 1-3.
Figs. 4, 5.
igs On.
Fig. 8.
Figs. 9, 10.
Figs. 11, 12.
PLATE 33
Oedogonium plusiosporum Wittrock, x 340
Oedogonium suecicum Wittrock, x 590
Oedogonium oviforme fa. gracile Prescott, x 590
Oedogonium patulum Tiffany, x 590
Oedogonium urceolatum Nordstedt & Hirn: 9, x 127;
10, x 590
Oedogonium carolinianum Tiffany: 11, x 500; 12, x 300
[ 726 ]
Rigs. 1-3:
Fig. 4.
Figs. 5, 6.
Figs. 7-9.
Fig. 10.
Figs. 11, 12.
Figs. 13, 14.
Figs. 15, 16.
PLATE 34
Oedogonium Reinschii Roy, x 700
Oedogonium psaegmatosporum Nordstedt, x 590
Oedogonium pyriforme Wittrock, x 675
Oedogonium minus (Wittr.) Wittrock: 8, oogonium
with extrusions of mucilage through the punctae of
the wall; all x 600
Oedogonium Kurzii Zeller, x 300
Oedogonium autumnale Wittrock: 11, x 675; 12, x 375
Oedogonium gracilimum Wittrock & Lundell, on fila-
ment of Microspora, x 750
Oedogonium Gunnii Wittrock, x 590
[ 728 ]
Figs. 1-3.
Fig. 4.
Figs. 5-7.
Figs. 8, 9.
Figs. 10, 11.
Figs. 12, 13.
PLATE 85
Oedogonium iowense Tiffany: 1, x 375; 2, x 700; 3, x
500
Oedogonium pseudo-Boscii Hirn, x 500
Oedogonium inclusum Hirn: 5, x 500; 6 and 7, x 250
Oedogonium Borisianum (Le Cl.) Wittrock: 8, x 125;
9, x 500
Oedogonium echinospermum A. Braun, x 300
Oedogonium Wolleanum Wittrock: 12, x 350; 18, x 175
[ 730 ]
Figs. 1-3.
Figs. 4, 5.
Figs. 6, 7.
Figs. 8, 9.
Fig. 10.
Figs. 11-14.
Figs. 15, 16.
Figs. 17-19.
Figs. 20, 21
PLATE 36
Oedogonium Pringsheimii Cramer: 1, x 625; 2 and 3,
«312
Oedogonium pratense Transeau, x 590
Oedogonium porrectum Nordstedt & Hirn, x 590
Oedogonium pisanum Wittrock, x 600
Oedogonium nanum Wittrock, x 350
Oedogonium microgonium Prescott, x 675
Oedogonium abbreviatum (Hirn) Tiffany, x 590
Oedogonium Smithii Prescott: 17 and 18, x 500; 19, x
650
Oedogonium epiphyticum Transeau & Tiffany, x 500
[ 732 ]
Bigs. 12.
Fig. 3.
Figs. 4, 5.
Fig. 6.
Figs. 7-9.
Fig. 10.
Pgs ae:
Figs. 13, 14.
Figs. 15, 16.
PLATE 37
Oedogonium inconspicuum Hirn, x 650
Oedogonium bohemicum Hirn, x 590
Oedogonium spurium Hirn, x 590
Oedogonium psaegmatosporum Nordstedt, x 590
Oedogonium ambiceps (Jao) Tiffany, x 590
Oedogonium trioicum Woronichin, x 590
Oedogonium pusillum Kirchner: 11, x 730; 12, x 600
Oedogonium Woyliei Tiffany, « 355
Oedogonium calvuum Wittrock, x 590
[ 734 ]
Figs.
Figs.
Figs.
Figs.
Figs
Figs
Meee
3, 4.
3), (0)
138:
oh IOS
» L112:
PLATE 38
Oedogonium paucostriatum Tiffany: 1, x 600; 2, x 300
Oedogonium spheroideum Prescott: 3, x 300; 4, x 600
Oedogonium punctatostriatum DeBary: 5, x 300; 6, x
600
Oedogonium Welwitschii West & West, x 590
Oedogonium Pringsheimii var. Nordstedtii (Witt)
Wittrock: 9, x 365; 10, x 590
Oedogonium tapeinosporum Wittrock, x 700
[ 736 ]
Fig. 10.
Pigs ii 12:
PLATE 389
Oedogonium Sawyerii Prescott, x 590
Oedogonium sexangulare Cleve: 2, x 600; 3, x 300
Oedogonium gallicum Hirn, x 590
Oedogonium subsexangulare Tiffany, x 450
Oedogonium perfectum (Hirn) Tiffany: 6, x 360; 7, x
175
Oedogonium Westii Tiffany, x 325
Oedogonium rugulosum fa. rotundatum (Hirn) Tif-
fany, x 500
Oedogonium striatum Tiffany, x 175
Oedogonium rugulosum fa. rotundatum (Hirn) Tif-
fany, x 500
[ 788 ]
Fig. 1.
Fig. 2.
Figs. 3-5.
Figs, 6; 7.
Fig. 8.
Fig. 9.
Fig. 10.
PLATE 40
Oedogonium spiraldens Jao, x 625
Oedogonium sinuatum fa. seriatum Prescott, « 300
Oedogonium undulatum (de Bréb.) A. Braun, x 350
Oedogonium Areschougii var. contortofilum Jao, « 625
Oedogonium subplenum Tiffany, x 750
Oedogonium pseudoplenum Tiffany, x 625
Oedogonium hians Nordstedt & Hirn, « 375
[ 740 ]
larger ale
Fig. 2.
Figs. 3, 4.
Figs. 5, 6.
Fige 7.
Figs: 3, 9:
Big. 10;
Fig wale
Fig. 12.
PLATE 4]
Oedogonium macrandrium Wittrock, x 625
Oedogonium decipiens var. africanum Tiffany, x 625
Oedogonium brasiliense Borge: 3, x 200; 4, x 440
Oedogonium acrosporum var. bathmidosporum (Nordst.)
Hirn fa., x 625
Oedogonium acrosporum DeBary, x 750
Oedogonium orientale Jao, x 400
Oedogonium acrosporum var. majusculum Nordstedt, x
300
Oedogonium Croasdaleae Jao, x 340
Oedogonium macrospermum West & West, x 625
[ 742 ]
PLATE 42
Figs. 1-3. Oedogonium oelandicum var. contortum Prescott, x
450
Figs. 4-6. Oedogonium Kozminskii Prescott: 4, x 750; 5, x 375
Figs. 7-9. Oedogonium polyandrium Prescott: 7 and 8, x 625; 9,
x 700
Fig. 10. Oedogonium hians Nordstedt & Hirn, x 500
Figs. 11,12. Oedogonium decipiens var. dissimile (Him) Tiffany,
x 625
Figs. 13,14. Oedogonium decipiens Wittrock: 13, x 700; 14, x 350
[ 744 ]
Figel
Figs. 2, 3.
Figs. 4, 5.
Figs. 6, 7.
Fig. 8.
Figs. 9-11.
iat 1D
Fig. 12x,
Figs. 13, 14.
Fug.) Lo:
Bags: N67,
Figs. 18, 19.
Fig. 20.
PLATE 43
Oedogonium minisporum Taft, x 365 (redrawn from
are)
Oedogonium oblongum var. minus Taft, x about 500
(redrawn from Taft )
Oedogonium argenteum fa. michiganense Tiffany, x
about 240 (redrawn from Ackley )
Oedogonium Tiffanyi Ackley, x about 200 (redrawn
from Tiffany )
Oedogonium Richterianum Lemmermann, x about 225
(redrawn from Tiffany )
Oedogonium michiganense Tiffany, x about 250 (re-
drawn from Tiffany )
Oedogonium Sodiroanum Lagerheim, x about 300 (re-
drawn from Tiffany )
Oedogonium capillare (L.) Kuetzing, x about 280
Oedogonium upsaliense Wittrock, x about 250 (re-
drawn from Tiffany )
Oedogonium princeps (Hass. ) Wittrock, x about 185
Oedogonium americanum Transeau, x about 200 (re-
drawn from Tiffany )
Oedogonium Vaucherii (Le Cl.) A. Braun, x about
260 (redrawn from Tiffany )
[ 746 ]
Toe eT i
Fig.
Sr, V5 eh
Figs. 9, 10.
Pigs. 11, 12.
Fig. 18.
Figs. 14, 15.
6
PLATE 44
Oedogonium spirostriatum Tiffany, x 340 (redrawn
from Tiffany )
Oedogonium latiusculum Tiffany, x 440
Oedogonium undulatum fa. senegalense (Nordst.)
Hirn, x 500
Oedogonium crispum (Hass.) Wittrock, x 300 (re-
drawn from Tiffany )
Oedogonium angustissimum West & West, x 775
Oedogonium capilliforme Kuetzing; Wittrock, « 425
Oedogonium crassum ( Hass.) Wittrock, x 275
Oedogonium mitratum Hirn, x 300 (redrawn from
Tiffany )
Oedogonium cyathigerum fa. ornatum (Wittr.) Hirn,
Slo
Oedogonium rugulosum Nordstedt, 590
[ 748 ]
Bie i.
Fig. 2.
Fig. 3.
Figs. 4, 5.
Figs. 6, 7.
Figs. 8-10.
Fig. 11.
Figs. 12, 13.
Fig. 14.
Fig. 15.
Fig. 16.
Fig. 17.
Fig. 18.
Big 9:
Fig. 20.
Fig. 21.
Figs. 22, 23.
PLATE 45
Chlorococcum humicola (Naeg.) Rabenhorst, x 500
Golenkinia paucispina West & West, x 750 (redrawn
from Smith )
Golenkinia radiata (Chod.) Wille, x 750 (redrawn
from Smith )
Acanthosphaera Zachariasi Lemmermann: 4, x 1000;
5, x 750 (redrawn from Smith )
Chlorochytrium Lemnae Cohn: 6, x about 250 (re-
drawn from Bristol-Roach); 7, x 250
Kentrosphaera gloeophila (Bohlin) Brunnthaler, « 625
Characium ambiguum Hermann, x 500
Characium curvatum G. M. Smith, x 2000 (redrawn
from Smith )
Characium falcatum Schroeder, x 700
Characium stipitatum (Bachm.) Wille, x 2000 (after
Smith )
Characium gracilipes Lambert, x 1000 (redraw from
Smith )
Characium Hookeri (Reinsch) Hansgirg, on Cyclops,
< 500
Characium limneticum Lemmermann, x 1000 (re-
drawn from Smith )
Characiopsis cylindrica (Lambert) Lemmermann, x
500 (redrawn from Smith)
Characium obtusum A. Braun, x 1650
Characium Pringsheimii A. Braun, x 800
Characium rostratum Reinhard: 22, x 500; 23, x 750
[ 750 ]
ga ga oa
rs
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i
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i jo}
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Co
Fig. 14.
Figs. 15, 16.
Figs. 17, 18:
Fig. 19.
Fig. 20.
PLATE 46
Chlorangium stentorinum (Ehrenb.) Stein, x 500
Coelastrum scabrum Reinsch, x about 1000 (redrawn
from Bohlin )
Lagerheimia citriformis var. paucispina Tiffany & Ahl-
strom, x about 1000 (redrawn from Tiflany & Ahl-
strom )
Dispora crucigenioides Printz, x 700
Characium acuminatum A. Braun, x about 500 (re-
drawn from Braun)
Ankistrodesmus Braunii (Naeg.) Brunnthaler, x 500
Desmatractum bipyramidatum (Chod.) Pascher, x 1500
Selenastrum minutum (Naeg.) Collins, x 1200
Lagerheimia quadriseta (Lemm.) G. M. Smith, x 600
Eremosphaera oocystoides Prescott, x 1250
Characium operculum Ackley, x about 850 (redrawn
from Ackley )
Characium ornithocephalum A. Braun, x 650
Excentrosphaera viridis Moore, x 500
Asterococcus spinosus Prescott: 17, x 800; 18, x 600
Characium Debaryanum (Reinsch) DeToni, x 320
Chlamydomonas mucicola Schmidle, x about 200 (re-
drawn from Schmidle )
Figs. 21, 2la Tetraédron quadratum (Reinsch) Hansgirg: 21, x 800;
Figs. 22, 23.
Figs. 24, 25.
Fig. 26.
Fig. 27.
21a, x 400
Tetraédron duospinum Ackley
Scenedesmus perforatus Lemmermann, x 1250
Stephanosphaera pluvialis Cohn, « 1000
Characium Rabenhorstii DeToni, « 750
[ 752 ]
bo
ed
Q
Co
PLATE 47
Hydrodictyon reticulatum (L.) Lagerheim, x 75
Euastropsis Richteri (Schmidle) Lagerheim, = 1000
(after Smith )
Pediastrum araneosum var. rugulosum (G. S. West) G.
M. Smith, x 590
Pediastrum araneosum (Racib.) G. M. Smith, x 590
(Reticulations on walls not shown.)
Pediastrum biradiatum Meyen: 5, x 600; 6, x 300
Pediastrum biradiatum var. emarginatum fa. convexum
Prescott, x 750
Pediastrum boryanum (Turp.) Meneghini, x 750
Pediastrum boryanum var. longicorne Raciborski, x 590
[ 754 ]
‘
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tae Ne Sy
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sigan fete EDN eB WAe oo Sy NOEs
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pa Airariaee Bi a eUh Races) Loni mete ey A eey 3) jh)
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us raat Eon sen) Nasser a
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Figs. 9, 10.
Fig.l.
Fig. 12.
PLATE 48
Pediastrum Boryanum (Turp.) Meneghini, « 330 (re-
drawn from Smith )
Pediastrum Boryanum var. undulatum Wille, « 500
Pediastrum Boryanum (Turp. ) Meneghini, « 500
Pediastrum duplex Meyen, x 500 (redrawn from Smith)
Pediastrum Braunii Wartmann, < 750
Pediastrum duplex var. clathratum (A. Braun) Lager-
heim, x 500
Pediastrum integrum var. priva Printz, x 666 (redrawn
from Smith )
Pediastrum duplex var. rotundatum Lucks, x 333 (re-
drawn from Smith )
Pediastrum integrum Naegeli: 9, x 330; 10, x 500
Pediastrum duplex var. cohaerens Bohlin, x 500
Pediastrum duplex var. gracilimum West & West, x
333 (after Smith )
[ 756 ]
PLATE 49
Pediastrum duplex var. reticulatum Lagerheim, x 333
(after Smith)
Pediastrum integrum var. scutum Raciborski, x 625
Pediastrum duplex var. rugulosum Raciborski, x 750
Pediastrum glanduliferum Bennett, x 1000 (redrawn
from Bisley, ex West and Fritsch, courtesy Macmillan
Publishing Co. )
Pediastrum sculptatum G. M. Smith, x 333 (after Smith)
Pediastrum obtusum Lucks, x 590
Pediastrum muticum Kuetzing, x 750
Pediastrum muticum var. crenulatum Prescott, x 750
[ 758 }
igene
Fig. 2.
Fig. 3.
Figs. 4, 5.
Fig. 6.
Figiy:
1 OU rep
Fig. 9.
Fig. 10.
PLATE 50
Pediastrum Kawraiskyi Schmidle, x 333 (after Smith )
Pediastrum simplex (Meyen) Lemmermann, x 500
Pediastrum tetras (Ehrenb.) Ralfs, x 1000
Pediastrum simplex var. duodenarium (Bailey) Raben-
horst, x 500
Pediastrum tetras (Ehrenb.) Ralfs, x 1000
Pediastrum tetras var. tetraodon (Corda) Rabenhorst,
x 1000 (redrawn from Smith)
Sorastrum americanum (Bohlin) Schmidle, x 500 (re-
drawn from Smith )
Sorastrum spinulosum Naegeli, x 750 (after Smith )
Sorastrum americanum var. undulatum G. M. Smith, x
750 (after Smith )
( 760 |
Figs. £52.
Figs. 3, 4.
Figs. 5-7.
Fig. 8.
Fig. 9.
Fig. 10.
Big, i.
Fig. 12.
Pigel3.
Fig. 14.
Fig. 15.
PLATE 51
Echinosphaerella limnetica G. M. Smith, x 750 (after
Smith )
Dictyosphaerium Ehrenbergianum Naegeli: 3, x 312; 4
x 37d
Dictyosphaerium pulchellum Wood: 5 and 6, x 500; 7,
details of cells and attaching strands, x 500
Treubaria setigerum (Archer) G. M. Smith, x 750 (re-
drawn from Smith
?
Oocystis crassa Wittrock, x 1000 (redrawn from Smith)
Oocystis Borgei Snow, x 750
Oocystis elliptica W. West, x 600
Oocystis Eremosphaeria G. M. Smith, x 590
Oocystis gloeocystiformis Borge, x 350
Oocystis gigas Archer, x 500
Oocystis pusilla Hansgirg, x 1000 (after Smith )
[ 762 ]
figs.i6, 7,
Fig. 8.
Figs. 9, 10.
Eig;
PLATE 52
Botryococcus Braunii Kuetzing, x 875 (redrawn from
Blackburn )
Botryococcus sudeticus Lemmermann, x 600 (redrawn
from Smith )
Botryococcus protuberans var. minor G. M. Smith: 4, x
750; 5, x 1500 (redrawn from Smith)
Tetraédron enorme ( Ralfs) Hansgirg fa., x 885
Trochiscia obtusa (Reinsch) Hansgirg, x 750
Gloeocystis major Gerneck: 9, x 750; 10, x 560
Botryococcus Braunii Kuetzing, x 600 (after Smith )
[ 764 ]
Figg.
Fig. 2,
Fig. 3.
Figs. 4, 5.
Fig. 6.
Fig. 7.
Fig. 8.
Fig, 9.
Fig. 10.
Figs. 11, 12.
Fig. 13.
Fig. 14.
Figs. 15, 16.
Bical 7.
Fig. 18.
Figs. 19, 20.
Biga2t,
Fig. 22.
Fig. 23.
PEATE 53
Sorastrum spinulosum N aegeli, x 590
Coelastrum cambricum Archer, x 412 (redrawn from
Smith )
Coelastrum microporum Naegeli, x 350
Coelastrum proboscideum Bohlin: 4, x 825 (redrawn
from Smith ); 5, x 650
Coelastrum reticulatum (Dang.) Senn, x 500
Coelastrum sphaericum Naegeli, x 237 (adapted from
West and Fritsch, courtesy Macmillan Publishing
Co.)
Coelastrum proboscideum Bohlin, x 825 (redrawn
from Smith )
Zoochlorella parasitica Brandt: cells in Ophrydium, x
500; enlarged cells, x 1000
Zoochlorella conductrix Brandt: cells within tentacles
of Hydra, x 100; enlarged cells, x 590
Chlorella ellipsoidea Gerneck: x 225; 12, x 650
Chlorella vulgaris Beyerinck, x 1000 (redrawn from
Smith )
Westella botryoides (W. West) de Wildemann, x 650
Westella linearis G. M. Smith, x 500 (after Smith)
‘Trochiscia aspera (Reinsch) Hansgirg, x 850
Trochiscia granulata (Reinsch) Hansgirg, « 590
Trochiscia reticularis (Reinsch) Hansgirg: 19, x 800;
20, x 1000 (redrawn from Smith )
Trochiscia Zachariasii Lemmermann, * 1000
Eremosphaera viridis DeBary, x 50
Planktosphaeria gelatinosa G. M. Smith, x 250
[ 766 ]
Bigs, 6:./.
Figs. 8, 9.
Fig. 10.
Fig. 11.
Fig. 12.
Figs. 13, 14.
Figs. 15, 16.
Fig. 17.
Fig. 18.
Fig. 19.
Fig. 20.
PLATE 54
Oocystis lacustris Chodat, x 1750
Oocystis natans var. major G. M. Smith, x 1000
Oocystis parva West & West, x 750
Oocystis pusilla Hansgirg: 4, colony, x 800; 5, single
cell, « 1350
Oocystis nodulosa West & West: 6, x 250; 7, x 400
(adapted from West, ex Brunnthaler )
Oocystis pyriformis Prescott, x 590
Oocystis solitaria Wittrock, x 1000
Oocystis panduriformis var. minor G. M. Smith, x 1000
Oocystis submarina Lagerheim, x 1000 (redrawn from
Smith )
Gloeotaenium Loitelsbergerianum Hansgirg, x 440
Nephrocytium Agardhianum Naegeli, x 500
Nephrocytium ecdysiscepanum W. West, x 500
Nephrocytium limneticum (G. M. Smith) G. M. Smith,
x 500
Nephrocytium lunatum W. West, x 750
Nephrocytium obesum West & West, x 590
| 768 J
bo
He O09
PLATE 55
Lagerheimia ciliata (Lag.) Chodat, x 100 (redrawn from
Smith )
Lagerheimia ciliata var. minor (G. M. Smith) G. M. Smith,
x 1000 (redrawn from Smith )
Ankistrodesmus convolutus Corda, x 1000
Lagerheimia citriformis (Snow) G. M. Smith, x 1000 (re-
drawn from Smith )
Lagerheimia longiseta (Lemm.) Printz, x 1000 (redrawn
from Smith )
Lagerheimia longiseta var. major G. M. Smith, x 1000 (re-
drawn from Smith )
Lagerheimia subsalsa Lemmermann, x 1000 (redrawn trom
Smith )
Dimorphococcus lunatus A. Braun, x 750
| 770 ]
Fig. 10.
Figs. 11, 12.
Fig. 13.
Figs. 14, 15.
Fig. 16.
PLATE 56
Franceia Droescheri (Lemm.) G. M. Smith, x 900 (re-
drawn from Smith )
Franceia ovalis (Francé) Lemmermann, x 1000 (re-
drawn from Smith )
Ankistrodesmus falcatus (Corda) Ralfs, x 500
Ankistrodesmus fractus (West & West) Brunnthaler,
x 700
Cerasterias staurastroides West & West, « 590
Ankistrodesmus falcatus var. tumidus (West & West)
G. S. West, x 1000 (after Smith )
Ankistrodesmus falcatus var. mirabilis (West & West )
G. S. West, x 1000 (after Smith )
Ankistrodesmus spiralis (Turner) Lemmermann, x
1000 (after Smith )
Dactylococcus infusionum Naegeli, x 735 (redrawn
from Smith )
Ankistrodesmus falcatus var. stipitatus (Chod.) Lem-
mermann, x 590
Ankistrodesmus falcatus var. acicularis (A. Braun) G.
S. West, x 1000 (redrawn from G. S. West)
PrATE yo”
Figeel: Closteriopsis longissima Lemmermann, x 300
Figs. 2,3. Closteriopsis longissima var. tropica West & West: 2, x
220; 3, x 400 (after Smith)
Fig. 4. Schroederia setigera (Schroed.) Lemmermann, x 1000
(after Smith )
Figs. 5,6. Schroederia Judayi G. M. Smith: 5, x 1000 (after Smith);
6, x 1500
Figs. 7,8. Kirchneriella contorta (Schmidle) Bohlin: 7, x 650; 8, x
1000
Fig. 9. Selenastrum Bibraianum Reinsch, x 1000 (redrawn from
Smith )
Fig. 10. Selenastrum Westii G. M. Smith, x 1000 (redrawn from
Smith )
Fig. 11. Selenastrum gracile Reinsch, x 1000 (redrawn from
Smith )
Big: Kirchneriella obesa var. major (Bernard) G. M. Smith,
x 500
[774 ]
PLATE 58
Fig. 1. Kirchneriella elongata G. M. Smith, x 1000 (redrawn
from Smith )
Fig. 2. Kirchneriella lunaris ( Kirch.) Moebius, x 500
Fig. 3. Kirchneriella lunaris var. Dianae Bohlin, x 500
Fig. 4. Kirchneriella lunaris var. irregularis G. M. Smith, x 1000
(redrawn from Smith )
Fig. 5. Kirchneriella obesa (W. West) Schmidle, « 500
Figs.6,7. | Kirchneriella obesa var. aperta (Teil.) Brunnthaler: 6,
x 600; 7, x 700
Fig. 8. Kirchneriella subsolitaria G. S. West, x 650
Figs.9,10. Quadrigula closterioides (Bohlin) Printz: 9, x 600; 10,
x 500
[ 776 ]
ee
Figs. 1-3.
Figs. 4, 5.
Figs. 6, 7.
Fig. 8.
Figs. 9, 10.
Figs. 11-13.
Fig. 14.
Figs. 15, 16.
Fig. 17.
igs 13:
Fig. 19.
Figs. 20-22.
Fig. 23.
Figs. 24, 25.
Fig. 26.
Fig. 27.
Fig. 28.
PLATE 59
Quadrigula Chodatii (Tanner-Fullman) G. M. Smith:
1, x 500 (redrawn from Smith); 2, x 590; 3, x 500
Quadrigula lacustris (Chod.) G. M. Smith, x 500
(after Smith )
Tetraédron armatum (Reinsch ) DeToni, x 400
Tetraédron arthrodesmiforme (W. West) Wolszyn-
ska, x 175 (redrawn from Tiffany )
Tetraédron arthrodesmiforme var. contorta Wotoszyn-
ska, x 1000
Tetraédron asymmetricum Prescott, x 500
Tetraédron bifurcatum (Wille) Lagerheim, x 500
Tetraédron bifurcatum var. minor Prescott: 15, x 500;
16, x 750
Tetraédron caudatum (Corda) Hansgirg, x 200
Tetraédron enorme var. pentaedricum Prescott, x 650
Tetraédron enorme (Ralfs) Hansgirg, x 650
Tetraédron caudatum var. longispinum Lemmermann,
< 1000 (redrawn from Smith)
Tetraédron cruciatum var. reductum Prescott, x 600
Tetraédron caudatum (Corda) Hansgirg, x 1000 (af-
ter Smith )
Tetraédron hastatum (Reinsch) Hansgirg, x 100 (after
Smith )
Tetraédron hastatum var. palatinum (Schmidle) Lem-
mermann, x 1000 (after Smith)
Tetraédron constrictum G. M. Smith, x 1000 (after
Smith )
[ 778 ]
Fig. 8.
Figs. 9, 10.
Fig. 11.
Figs. 12-15.
Figs. 16, 17.
Fig. 18.
PLATE 60
Tetraédron gracile (Reinsch) Hansgirg, x 1000 (after
Smith )
Tetraédron limneticum Borge: 2-3, x 590; 4, x 1000
Tetraédron limneticum var. gracile Prescott, x 590
Tetraédron lobulatum (Naeg.) Hansgirg, x 1000 (after
Smith )
Tetraédron lobulatum var. crassum Prescott, x 1000
Tetraédron lunula (Reinsch) Wille, x 1000
Tetraédron lobulatum var. polyfurcatum G. M. Smith,
< 1000 (after Smith )
Tetraédron minimum (A. Braun) Hansgirg, x 1000
(14 and 15, after Smith)
Tetraédron muticum (A. Braun) Hansgirg: 16, x 1000;
17, x 590
Tetraédron muticum fa. punctulatum (Reinsch) De-
Toni, x 1000 (after Smith)
Tetraédron obesum (West & West) Wille: 19, x 600;
20, x 650
Tetraédron pentaedricum West & West, x 1000 (23,
after Smith)
Tetraédron regulare Kuetzing, x 1000 (26, after Smith)
Tetraédron planctonicum G. M. Smith, x 1500
Tetraédron pusillum (Wallich) West & West, x 1750
(redrawn from Turner, ex Brunnthaler )
[ 780 }
Fig
Figs. 2, 3.
Figs. 4-7.
Figs. 8-10.
Pigs iL 12,
Fig. 18.
Figs. 14-16.
Figs 17,18:
Figs. 19, 20.
Fig. 21.
Figs. 22, 23,
Figs. 24, 25.
Figs. 26, 27.
Figs. 28, 29.
PLATE 61
Tetraédron regulare var. bifurcatum Wille, x 500
Tetraédron regulare var. granulata Prescott, x 500
Tetraédron regulare var. incus Teiling, x 500 (6 and
7, after Smith )
Tetraédron regulare var. torsum (Turner) Brunntha-
ler: 8 and 9, x 500 (after Smith); 10, x 1000
Tetraédron trigonum (Naeg.) Hansgirg, x 500
Tetraédron regulare var. incus fa. major Prescott,
2500
Tetraédron trigonum var. gracile (Reinsch) DeToni,
x 1000
Tetraédron tumidulum (Reinsch) Hansgirg, x 1000
Cerasterias staurastroides West & West: 19, x 2500; 20,
x 4000
Scenedesmus abundans (Kirch.) Chodat, x 500 (after
Smith )
Scenedesmus abundans var. asymmetrica (Schroed. )
G. M. Smith, x 500 (after Smith)
Tetraédron verrucosum G. M. Smith, x 500 (after
Smith )
Scenedesmus abundans var. brevicauda G. M. Smith,
x 500 (redrawn from Smith )
Tetraédron Victorieae var. major G. M. Smith, x 500
(after Smith )
[ 782 ]
Fig,
Figs. 2, 3.
Figs. 4, 5.
igs 10a.
Fig. 8.
Fig. 9.
Figs. 10-12.
Figs. 13, 14.
Fig, 15,
Fig. 16.
PLATE 62
Scenedesmus abundans var. breviccuda G. M. Smith,
iy
Ww
A
4
(yy)
AAW
’ ND
'
if my
NY { WY
S)
\) '
7 Xi
a Xs SY
Rh)
SM)
SS
we |
\ WIA
y SAX WY
i Wi
tht
Wy
Ua)
Wy
mi rh
WZ
a
SS
PLATE 81
Bigeall Chara Braunii Gmelin, x 65
Figs. 2-6. | Chara canescens Loiseleur-Deslongchamps: 2, portion
of plant, x 1; 3 and 4, apices of branchlets, x 50; 5,
node, x 15; 6, oogonium, x 25
Figs. 7-10. Chara excelsa Allen: 7, cortications, x 20; 8, nodes of
cortical cells, x 40; 9, apex of branchlet, x 47; 10,
oogonium, x 40
[ 822 ]
PLATE 82
Figs. 1-5. Chara vulgaris Linnaeus: 1, portion of plant, x 12°2;
apex of branchlets, x 31; 3 and 4. node, x 12; 5,
oogonium, x 16
Figs. 6-8. Chara fragilis Desvaux: 6, apex of branchlet, x 18; 7,
sex organs, x 14; 8, node, x 14
Figs. 9-12. Chara sejuncta A. Braun: 9, portion of fertile branch-
let, x 13; 10, apex of branchlet, x 14; 11, node, x 19;
12, portion of axis showing cortical and spine cells,
ein
Figs. 13-15. Chara elegans (A. Braun) Robinson: 13, sex organs,
x 50; 14, apex of branchlet, x 50; 15, node, x 22
[ 824 ]
Wy
" Wi
VN
i) \\
Se hy
‘NY
I
\ ll
iS s
i al aL “wy if
. WHE WW, we
Bien:
Figs. 2, 3.
Figs. 4, 5.
Fig. 6.
Wigs: 7,8:
Fig. 9.
Fig. 10.
Fig i.
Fig. 12.
Fig. 13.
Figs. 14, 15.
Figs. 16, 17.
Figs. 18, 19.
Fig. 20.
Fig. 21.
Figs. 22, 23.
Figs. 24, 25.
Fig. 26.
Fig. 27.
Fig. 28.
Fig. 29.
Fig. 30.
Papo:
Fig. 32.
Fig. 33.
Fig. 34.
Fig. 35.
PLatTe 83
Trachelomonas volvocina Ehrenberg, x 938
Trachelomonas volvocina var. compressa Drezepolski:
2150023, x 1125
Trachelomonas varians (Lemm.) Deflandre, x 885
Trachelomonas triangularis Deflandre, « 1500
Trachelomonas volvocina Ehrenberg fa., x 750
Trachelomonas rotunda Swirenko, x 885
Trachelomonas intermedia Dangeard, x 885
Trachelomonas cylindrica Ehrenberg, x 885
Trachelomonas volvocina var. punctata Playfair, x
1500
Trachelomonas acanthostoma (Stokes) Deflandre, x
885
Trachelomonas lacustris Drezepolski, x 938
Trachelomonas Kelloggii (Skv.) Deflandre, x 885
Trachelomonas abrupta (Swir.) Deflandre, x 885
Trachelomonas cylindrica Ehrenberg, x 885
Trachelomonas Dybowskii Drezepolski, x 1500
Trachelomonas pulcherrima Playfair, x 885
Trachelomonas pulcherrima var. minor Playfair, x 1050
Trachelomonas armata var. Steinii Lemmermann, x
DES)
Trachelomonas armata var. longispina (Playf.) De-
flandre, x 975
Trachelomonas pulchella Drezepolski, x 975
Trachelomonas robusta Swirenko, « 1125
Trachelomonas hispida var. coronata Lemmermann,
x 885
Trachelomonas hispida var. crenulatocollis fa. recta
Deflandre, « 900
Trachelomonas armata (Ehrenb.) Stein, x 1125
Trachelomonas armata fa. inevoluta Deflandre, x 900
Trachelomonas superba var. Swirenkiana Deflandre,
x 900
Trachelomonas hispida (Perty ) Stein, x 885
[| 826 ]
Fig
g.
Fig.
Figs. 3, 4.
lEs
D)
Fig.
Fig. 6.
Fig. 7.
Figs. 8, 9.
ga’ ga gq aa ga
Q oO
i
comes
Q
S:
oe
OF
ie
12.
PLATE 84
Trachelomonas horrida Palmer, x 1125
Trachelomonas sydneyensis Playfair, x 885
Trachelomonas hispida var. punctata Lemmermann, x
885
Trachelomonas superba var. spinosa Prescott, x 1125
Trachelomonas Dybowskii Drezepolski, x 750
Trachelomonas hispida var. papillata Skvortzow, x 975
Trachelomonas superba var. Swirenkiana Deflandre: §,
~ 9a 91050
Trachelomonas superba (Swir.) Deflandre, x 1125
Trachelomonas superba var. duplex Deflandre, x 1125
Trachelomonas similis Stokes, x 1500
Trachelomonas speciosa Deflandre, x 885
Trachelomonas Girardiana (Playf.) Deflandre, x 885
Trachelomonas bulla (Stein) Deflandre, « 885
Trachelomonas hexangulata var. repanda Prescott, x 885
Trachelomonas crebea var. brevicollaris Prescott, x 1125
[ 828 ]
PLATE 85
Figs. 1, 2. Trachelomonas dubia (Swir.) Deflandre, « 885
Fig. 3. Trachelomonas acanthostoma (Stokes) Deflandre, x
125
Fig. 4. Trachelomonas aculeata fa. brevispinosa Prescott, x
750
Figs. 5, 6. Trachelomonas hexangulata Swirenko, x 885
Figs/(. Trachelomonas scabra var. longicollis Playfair, x 1125
Figs. 8, 9. Trachelomonas Playfairii Deflandre, x 885
Fig. 10. Trachelomonas similis Stokes, x 1500
Big. 1. Trachelomonas hexangulata Swirenko fa., « 885
Fig. 12. Trachelomonas mammillosa Prescott, « 900
Fig. 18. Trachelomonas similis Stokes, x 1200
Fig. 14. Trachelomonas charkowiensis Swirenko, x 1050
Fig. 15. Trachelomonas lacustris Drezepolski, « 885
Fig. 16. Trachelomonas erecta Skvortzow, x 900
Fig. 17. Euglena gracilis Klebs, x 750
Fig. 18. Euglena oxyuris var. minor Prescott, x 750
Fig. 19. Trachelomonas spectabilis Deflandre, « 885
Fig. 20. Euglena deses Ehrenberg, x 195
Figs. 21,22. Euglena polymorpha Dangeard, = 450
Figs. 23,24. Euglena minuta Prescott, x 885
Fig. 25. Euglena proxima Dangeard, = 885
Fig. 26. Phacus pseudoswirenkoi Prescott, x 975
Fig. 27. Euglena acus var. rigida Huebner, x 900
Fig. 28. Euglena acus Ehrenberg, x 885
[ 830 ]
PLATE 86
igss 2: Euglena sanguinea Ehrenberg, x 750
Fig, 3. Euglena elongata Schewiakoff, x 1200
Figs. 4-6. Euglena tripteris (Duj.) Klebs: 4 and 5, = 885; 6, x
1200
Figs. 7-9. Euglena convoluta Korshikov, x 885
Figs. 10-12. Euglena elastica Prescott, x 975
Fig. 13. Euglena Ehrenbergii Klebs, x 375
Fig. 14. Euglena convoluta Korshikov, paramylon bodies
Fig. 15. Euglena Spirogyra Ehrenberg, x 885
[ 882 ]
Riged,
Fig. 2.
Fig. 3.
Figs. 4-6.
Figs: 1,0.
Fig. 9.
Fig. 10.
Rig ar
Fig. 12.
Fig. 13.
Fig. 14.
Figs. 15, 16.
PLATE 87
Phacus longicauda (Ehrenb.) Dujardin, « 750
Phacus pseudoswirenkoi Prescott, x 975
Phacus anacoelus var. undulata Skvortzow, x 675
Phacus Spirogyra var. maxima Prescott: 4, x 675; 5 and
6, x 750
Phacus anacoelus Stokes: 7, x 1125; 8, apical view
Phacus helikoides Pochmann, x 750
Phacus orbicularis Huebner, x 750
Phacus Birgei Prescott, x 750
Phacus orbicularis var. caudatus Skvortzow, x 900
Phacus caudatus Huebner, x 885
Phacus curvicauda Swirenko, x 900
Phacus chloroplastes Prescott, x 900
[ 834 }
ig. Je
Figs. 2, 3.
Fig. 4.
Figs. 5-8.
Fig. 9.
Paget;
Faget
Fig. 12.
Fig. 13.
Fig. 14.
Fig. 15.
Fig. 16.
Figs: 7518;
Rigg:
Fig. 20.
ag. 2,
Pig. 22.
Fig. 23.
Fig. 24.
PLaTE 88
Phacus Nordstedtii Lemmermann, x 885
Phacus suecicus Lemmermann, x 900
Phacus acuminatus Stokes, x 885
Phacus chloroplastes fa. incisa Prescott, « 900
Phacus crenulata Prescott, « 1125
Phacus orbicularis var. Zmudae Namyslowski, « 1125
Phacus anacoelus Stokes, x 885
Phacus Lemmermannii (Swir.) Skvortzow, x 900
Phacus caudata var. ovalis Drezepolski, x 900
Phacus pseudoswirenkoi Prescott, x 1050
Phacus orbicularis var. caudatus Skvortzow, x 900
Phacus pleuronectes (Muell.) Dujardin, « 885
Phacus acuminatus var. Drezepolskii Skvortzow, = 885
Phacus asymmetrica Prescott, x 1500
Phacus tortus (Lemm.) Skvortzow, = 885
Phacus curvicauda Swirenko, x 1050
Phacus pyrum (Ehrenb. ) Stein, x 750
Phacus Segretii var. ovum Prescott, x 900
Phacus Swirenkoi Skvortzow, x 1125
[ 836 ]
Figs. 1-4.
Figs. 5, 6.
Fig. 7.
Figs. 8, 9.
Fig. 10.
Figs. 11-13.
Fig. 14.
Fig. 15.
Fig. 16.
Pica li,
Figs. 18, 19.
Fig. 20.
Fig. 21.
Fig. 22.
Fig. 23.
PLATE 89
Lepocinclis fusiformis (Carter ) Lemmermann, x 900
Lepocinclis ovum (Ehrenb.) Lemmermann, x 885
Lepocinclis fusiformis var. major Fritsch & Rich, x 900
Lepocinclis acuta Prescott, x 1050
Lepocinclis glabra ta. minor Prescott, x 900
Lepocinclis Sphagnophila Lemmermann, x 1050
Lepocinclis glabra Drezepolski, x 750
Lepocinclis fusiformis var. major Fritsch & Rich, x 900
Lepocinclis Playfairiana Deflandre, = 900
Trachelomonas granulosa Playfair, x 885
Colacium vesiculosum Ehrenberg, x 585
Phacus anacoelus var. undulata fa. major Prescott, x
1050
Trachelomonas euchlora (Ehrenb.) Lemmermann, x
750
Colacium arbuscula Stein, x 885
Gymnodinium fuscum (Ehrenb.) Stein, x 675
[ 838 ]
Figs. 1-3.
Figs. 4-6.
Fig. 7.
Figs. 8, 9.
Figs. 10, 11.
Figs. 12-14.
Figs, lo; 16:
Figs. 17, 18.
Figs. 19, 20.
Fig. 21.
Figs. 22-24.
Figs. 25, 26.
Figs. 27-29.
PLATE 90
Gymnodium caudatum Prescott: 1 and 2, x 700; 3, x
600
Hemidinium nasutum Stein: 4 and 5, x 560; 6, x 1000
Glenodinium armatum Levander, x 700
Glenodinium Borgei (Lemm.) Schiller, x 700
Glenodinium Gymnodinium Penard: 10, x 700; 11, x
about 700 (redrawn from Wotoszynska )
Glenodinium Kulczynskii (Wotosz.) Schiller, x 590
Glenodinium palustre (Lemm. ) Schiller, x 1000
Glenodinium pulvisculus (Ehrenb.) Stein, x 750
Glenodinium quadridens (Stein) Schiller, x 600
Glenodinium Penardiforme (Linde. ) Schiller, x 750
Peridinium inconspicuum Lemmermann, x 590
Peridinium gatunense Nygaard: 25, « 350; 26, x 500
Dinoflagellate cysts, x 500
[ 840 ]
Figs.
Figs.
Figs.
Figs.
Figs.
Figs.
Figs.
PLATE 91
Peridinium cinctum (Muell.) Ehrenberg, x 600
Cystodinium cornifax (Schill.) Klebs, x 300
Peridinium cinctum var. tuberosum (Meunier ) Linde-
man: 7, x 600; 8-10 (after Meunier, ex Schiller), x
about 188; 1] and 12, x 600
Peridinium wisconsinense Eddy: 13 and 15, x 500; 14,
x 250
Peridinium limbatum (Stokes ) Lemmermann, x 750
Cystodinium iners Geitler: 19, x 750; 20 and 21, x 325
(21 redrawn from Geitler )
Peridinium Willei Huitfeld-Kaas: 22, x 600; 23 and
24, x 440; 25, x 600
[ 842 |
ig
Figs. 2, 3.
Figs. 4, 5.
Figs. 6; 7.
Figs. 8, 9.
PLATE 92
Synura Adamsii G. M. Smith, x 590
Ceratium carolinianum (Bailey ) Jorgensen, x 500
Ceratium hirundinella (O. F. Muell.) Dujardin: 4, cyst,
x 590; 5, x 1000
Synura uvella Ehrenberg: 6, x 1250; 7, x 500
Ceratium cornutum (Ehrenb.) Claparéde & Lachmann,
x 500
[ 844 ]
Figs. 1, 2.
Fig. 3.
Figs. 4-7.
Figs. 8-10.
Figs. 11-13.
Figs. 14, 15.
Figs. 16-19.
Figs. 20-22.
Figs. 23-25.
Figs. 26, 27.
Figs. 28, 29.
Fig. 30.
Bigsot.
Fig. 32.
Figs. 33, 34.
Figs. 35, 36.
PLATE 93
Cystodinium Steinii Klebs, x 500
Tetradinium javanicum Klebs, x 500
Raciborskia bicornis Woloszynska, x 600
Chlorochromonas minuta Lewis, x 1500 (redrawn from
Smith )
Stipitococcus apiculatus Prescott: 11 and 12, x 600; 13,
x 2000
Stipitococcus capense Prescott, x 590
Stipitococcus crassistipatus Prescott, x 1000
Stipitococcus urceolatus West & West, x 2000
Harpochytrium Hyalothecae Lagerheim, x 590
Chlorobotrys regularis (W. West) Bohlin, x 590
Centritractus dubius Printz, x 1000
Mischococcus confervicola Naegeli, x 590
Characiopsis lageniformis Pascher, x 750
Characiopsis longipes (Rab.) Borzi, x 1000
Characiopsis pyriformis (A. Braun) Borzi, x 590
Gloeobotrys limneticus (G. M. Smith) Pascher, x 590
[ 846 ]
Migs 1 2:
Figs. 3-5.
Fig. 6.
Figs. 7-9.
Figs. 10, 11.
Fig. 12.
Figs. 13, 14.
Fug: Lo.
Fig. 16.
Figs. 17, 18.
Fig. 19.
Fig. 20.
Figs. 21, 22.
Fig, 23.
PLaTE 94
Characiopsis cylindrica (Lambert) Lemmermann, x
590
Characiopsis spinifer Printz, x 590
Peroniella Hyalothecae Gobi, x 590
Peroniella planctonica G. M. Smith, x 1000 (9, redrawn
from Smith )
Ophiocytium cochleare (Eichw.) A. Braun, x 590
Ophiocytium arbuscula (A. Braun) Rabenhorst, « 590
Ophiocytium elongatum var. major Prescott, x 590
Ophiocytium cochleare (Eichw.) A. Braun, x 600
Ophiocytium mucronatum (A. Braun) Rabenhorst, x
590
Ophiocytium majus Naegeli: 6, x 400; 7, x 590
Ophiocytium capitatum var. longispinum (Moebius)
Lemmermann, x 1000 (after Smith )
Ophiocytium parvulum (Perty) A. Braun, x 1000 (re-
drawn from Smith )
Ophiocytium capitatum Wolle, x 590
Ophiocytium bicuspidatum (Borge) Lemmermann, x
400
[ 848 ]
Figs. 1-3.
Fig. 4.
Fig. 5.
Figs. 6-8.
Figs. 9, 10.
Big. e
Figs. 12, 13.
Fig. 14.
Figs 15,
Figs. 16—18.
Figs. 19, 20.
Figs. 21, 22.
Fig. 23.
Fig, 24.
Figs. 25, 26.
Figs. 27, 28.
Figs. 29-31.
Figs. 32, 33.
Fig. 34.
Figs. 35, 36.
Figs. 37, 38.
Fig. 39.
Fig. 40.
Fig. 41.
Fig. 42.
Figs. 43, 44.
Fig. 45.
PLATE 95
Goniochloris sculpta Geitler, x 1000
Chlorallanthus oblongus Pascher, x 1500
Trachychloron biconicum Pascher, x 1500
Bumilleriopsis brevis Printz, x 1500
Arachnochloris minor Pascher, x 1500
Chlorothecium Pirottae Borzi, « 1500
Tetragoniella gigas Pascher, x 550
Diachros simplex Pascher, x 625
Pleurogaster lunaris Pascher, x 500
Chlorellidiopsis separabilis Pascher, x 1000
Pleurogaster oocystoides Prescott, x 1000
Meringosphaera spinosa Prescott, « 800
Chlorellidiopsis separabilis Pascher, x 1000
Monallantus brevicylindrus Pascher, x 1000
Perone dimorpha Pascher, x 1000 (26, redrawn from
Pascher )
Botrydiopsis arhiza Borzi: 27, x 500, 28, x 1500
Characiopsis acuta (A. Braun) Borzi, x 1000
Stipitococcus vasiformis Tiffany, x 1000
Derepyxis dispar (Stokes ) Senn, x 1000
Ophiocytium gracilipes (A. Braun) Rabenhorst, x
Centritractus belanophorus Lemmermann, x 500
Cryptomonas erosa Ehrenberg, x 1000
Cryptomonas ovata Ehrenberg, x 1000
Chrysostephanosphaera globulifera Scherftel, x 400
Chlorochloster pyreniger Pascher, x 625
Trachychloron depauperatum Pascher, x 1500
Chroomonas Nordstedtii Hansgirg, x 1000
[ 850 |
Bigel:
Figs. 2, 3.
Figs. 4, 5.
Fig. 6.
Figs. 7-9.
Fig. 10.
Fig. 11.
Figs. 12, 13.
Figs. 14-16.
Figs. 17, 18.
Fig. 19.
DA),
ee
wo wo Ww bw
me 09 LO
PLATE 96
Phaeothamnion confervicola Lagerheim, x 590
Ophiocytium desertum var. minor Prescott, x 590
Ophiocytium parvulum (Perty) A. Braun, x 590
Bumilleria sicula Borzi, x 590
Tribonema affine G. S. West, x 500
Tribonema bombycinum (C. A. Ag.) Derbés & Solier,
x 600
Tribonema bombycinum var. tenue Hazen, x 750
Tribonema minus (Wille) Hazen: 12, x 590; 13, x 1000
Tribonema utriculosum (Kuetz.) Hazen: 14 and 15,
x 590; 16, x 800
Botrydium granulatum (L.) Greville: 17, x 18; 18, x 4
Mallomonas alpina Pascher & Ruttner, x 500
Mallomonas acaroides var. Moskovensis (Wermel)
Krieger, x 590
Derepyxis amphora Stokes, x 700
Mallomonas acaroides Perty, x 750
Mallomonas pseudocoronata Prescott, x 500
Mallomonas elliptica (Kisselew ) Conrad, x 500
[ 852 ]
PLATE 97
igs. Mallomonas caudata Iwanoff, x 590
Fig, 2. Mallomonas fastigata var. macrolepis (Conrad) Con-
rad, x 750 |
Fig. 3. Mallomonas apochromatica Conrad, x 590
Fig. 4. Mallomonas producta (Zacharias ) Iwanoff, x 500 (re-
drawn from Smith )
Fig. 5. Mallomonas producta var. Marchica Lemmermann, x
500 (redrawn from Smith )
Fig. 6. Mallomonas tonsurata Teiling, x 500 (redrawn from
Smith )
Fig. 7. Mallomonas urnaformis Prescott, x 1000
Fig. 8. Chrysostrella paradoxa Chodat, x 800
Fig. 9. Lagynion ampullaceum (Stokes ) Pascher, x 600
Fig. 10. Lagynion macrotrachelum (Stokes ) Pascher, x 1000
Big TT: Lagynion triangularis var. pyramidatum Prescott, x
1000
Figs. 12,18. Lagynion reductum Prescott: 12, x 590; 13, x 1000
Fig. 14. Lagynion Scherffelii Pascher, x 600
[ 854 ]
PLATE 98
Chrysosphaerella longispina Lauterborn, x 700
Rhizochrysis limnetica G. M. Smith, x 400 (redrawn
from Smith )
Dinobryon Tabellariae (Lemm.) Pascher, x 1000 (re-
drawn from Smith)
Dinobryon bavaricum Imhof, x 700
Dinobryon divergens Imhof, x 750
Dinobryon calciformis Bachmann, x 1000 (after Smith)
Dinobryon sertularia Ehrenberg, 500
Hyalobryon mucicola (Lemm.) Pascher, x 1000
Dinobryon sociale Ehrenberg, x 750
{| 856 |
PLATE 99
Figs. 1-5. Uroglenopsis americana (Calkins) Lemmermann, x
1000 (3-5 after Smith )
Fig. 6. Chrysamoeba radians Klebs, x 1000 (after Smith)
PigaT. Chrysidiastrum catenatum Lauterborn, x 500 (after
Smith )
Fig. 8. Chrysocapsa planctonica (West & West) Pascher,
1000 (after Smith )
Figs.9,10. | Phaeothamnion confervicola Lagerheim, x 500
Figs. 11,12. Gonyostomum semen (Ehrenb. ) Diesing, x 500
[ 858 ]
Figs, 1-3.
Figs. 4, 5.
Fig. 6.
Fig.
Figae:
Fig. 9.
be
Fig.
10.
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14,
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BAG),
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g. 18.
g. 19.
PLATE 100
Chroococcus dispersus var. minor G. M. Smith, x 825
(redrawn from Smith)
Chroococcus limneticus Lemmermann, x 500
Chroococcus limneticus var. carneus (Chod.) Lemmer-
mann, x 310
Chroococcus dispersus (Keiss].) Lemmermann, x 825
Chroococcus limneticus var. distans G. M. Smith, x 750
Chroococcus minutus (Kuetz.) Naegeli, x 600
Chroococcus limneticus var. subsalsus Lemmermann, x
825 (redrawn from Smith)
Chroococcus limneticus var. elegans G. M. Smith, x 825
(redrawn from Smith )
Chroococcus minor (Kuetz.) Naegeli, x 590
Chroococcus Prescottii Drouet & Daily, x 600
Chroococcus pallidus Naegeli, x 590
Chrooceccus varius A. Braun, x 1000
Chroococcus giganteus W. West, x 825 (redrawn from
Smith )
M erismopedia tenuissima Lemmermann, x 1250
Merismopedia elegans var. major G. M. Smith, x 500
Chroococcus turgidus (Kuetz.) Naegeli. x 590
[ 860 |
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PLATE 101
Figs. Merismopedia elegans A. Braun, x 500
Figs, 2-4. Merismopedia glauca (Ehrenb.) Naegeli: 2, x 590; 3,
x 600; 4, x 590
Fig. 5. Merismopedia Trolleri Bachmann, x 1000
Fig. 6. Gloeocapsa aeruginosa (Carm.) Kuetzing, x 750
Lae fe Gloeocapsa punctata Naegeli, x 750
Figs. 8, 9. Aphanocapsa delicatissima West & West: 8, x 900; 9,
x 1000
Figs. 10,11. Aphanocapsa elachista var. conferta West & West, x
750
Fig. 12. Aphanocapsa elachista var. planctonica G. M. Smith,
x 500
Fig. 13. Aphanocapsa endophytica G. M. Smith, x 1000 (re-
drawn from Smith)
Fig. 14. Aphanocapsa pulchra (Kuetz.) Rabenhorst, x 500
Figs. 15,16. Aphanocapsa Grevillei (Hass.) Rabenhorst, 500
Fig. 17. Aphanocapsa rivularis (Carm.) Rabenhorst, x 825 (re-
drawn from Smith )
[ 862 |
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PLATE 102
Figs. 1-3. Microcystis aeruginosa Kuetz.; emend. Elenkin: 1, x 170;
2, x 1500; 3, x 940
Fig. 4. Microcystis aeruginosa Kuetz.; emend. Elenkin: unper-
forated colony (M. flos-aquae ), x 750
Fig. 5. Microcystis incerta Lemmermann, x 750
Figs. 6-8. Synechococcus aeruginosus Naegeli, x 940
Fig. 9. Glocothece linearis Naegeli, x 750
Fig. 10. Merismopedia punctata Meyen, x 750
[ 864 ]
Rigel
Figs. 2,3:
Fig. 4.
Figs. 5, 6.
Figs. 7, 8.
Figs. 9, 10.
Figs. 11, 12.
Fig, 13.
Figs. 14-16.
PLATE 103
Gloeothece linearis var. composita G. M. Smith, x 750
Gloeothece rupestris (Lyngb.) Bornet, x 750
Rhabdoderma Gorskii Woloszynska, x 750
Rhabdoderma sigmoidea fa. minor Moore & Carter: 5,
7100s oN x Silo
Cyanarcus hamiformis Pascher, x 3000
Rhabdoderma irregulare (Naumann ) Geitler, x 750
Rhabdoderma lineare Schmidle & Lauterborn: 11, x
750; 12, x 1500
Merismopedia convoluta de Brébisson, x 600
Aphanothece stagnina (Spreng.) A. Braun: 14 and 16,
habit, x 1; 15, x 750
[ 866 ]
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Figs. 4, 5.
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Fig. 8.
Figs. 9, 10.
PLatTe 104
Aphanothece saxicola Naegeli, x 900
Aphanothece nidulans P. Richter: 2, x 750; 3 (drawn
from a specimen in the Field Museum of Natural
History ), x 1500
Pelogloea bacillifera Lauterborn, x 750
Aphanothece clathrata G. S. West: 6, x 900; 7, x 1500
Aphanothece gelatinosa (Henn. ) Lemmermann, x 750
Aphanothece microscopica Naegeli: 9, x 750; 10, cells
in detail, x 1500
[ 868 |
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Figs. 1, 2.
Figs. 3, 4.
Figs. 5, 6.
Figs. 7-9.
Figs. 10-12.
Figs. 13-15.
Fig. 16.
Puate 105
Dactylococcopsis acicularis Lemmermann: 1, x 750; 2,
S25
Dactylococcopsis Smithii Chodat & Chodat: 3, x 975;
4, x 490
Aphanothece Castagnei (de Bréb.) Rabenhorst: 5, x
1875; 6, x 1500
Aphanothece microspora (Menegh.) Rabenhorst: 7,
habit of colony, x 1; 8 and 9, x 900
Dactylococcopsis fascicularis Lemmermann: 10, x 500;
Vand 2 se7a0)
Dactylococcopsis rhaphidioides Hansgirg: 13 and 14,
Pleurocapsa, 590
~ Pleurochloridaceae, 348
Pleurococcus. See Protococcus
Pleurodiscus, 296
Pleurogaster, 353, also 349, 587
Junaris, 353; Pl. 95
oocystoides, 353; Pl. 95
Polyblepharidaceae, 68
Polycystis, 455, 592
Polyedriopsis, 271, also 235, 578
quadrispina 578
spinulosa, 272; Pl. 62
[974]
Porphyridaceae, 563
Porphyridium, 563, also 586
cruentum, 564; Pl. 136
Potamogeton, 531, 560
Preservatives, 1x
Production in lakes, 23, 34, 35, 37, 42
Protococcaceae, 126
Protococcus, 126, also 112, 575, 578, 580
viridis, 127; Pl. 10
Protoderma, 123, also 114, 583
viride, 123; Pls. 9, 14
Pseudotetraspora, 92
Pseudulvella, 123, 114, 583
americana, 124; Pl. 15
Pteromonas, 73, 572
angulosa, 73
Pyramimonas, 68, also 572
tetrarhyncus, 68; Pl. 1
Pyrrhophyta, 423, also 1, 2, 421
Quadrigula, 259, also 234, 282, 575
Chodatii, 260; Pl. 59
closterioides, 260; Pl. 58
lacustris, 260; Pl. 59
Raciborskia, 439, also 438, 589
bicornis, 440; Pl. 93
Radiofilum, 102, also 94, 582
apiculatus. See Radiofilum conjunctivum
conjunctivum, 103, also 104; Pl. 7
flavescens, 103; Pl. 7
irregulare, 104, also 103; Pl. 7
Rhabdoderma, 462, also 445, 591
Gorskii, 463, also 462; Pl. 103
irregulare, 463, also 462; PI. 103
lineare, 463, also 462; Pl. 103
sigmoidea, 462
fa. minor, 463; Pl. 103
Rhizochloridales, 344, also 343
Rhizochrysidales, 380, also 369
Rhizochrysidaceae, 381
Rhizochrysis, 382, also 381, 589
limnetica, 382; Pl. 98
Rhizoclonium, 141, also 123, 135, 137, 138,
498, 500, 503, 540, 554, 581, 584
crassipelitum, 141; Pl. 23
var. robustum, 141
fontanum, 142, also 141; Pl. 23
hieroglyphicum, 142, also 141; Pl. 23
var. Hosfordii, 142
var. macromeres, 142
Hookeri, 143, also 141; Pl. 23
Rhizolekane, 344
Rhodophyceae, 562
Rhodophyta, 562, also 2
Ricciocarpus, 521, 525
Rivularia, 556, also 550, 557, 560, 593
haematites, 556; Pl. 131
minutula, 556; Pl. 136
Rivulariaceae, 550, also 478, 509
Sacconema, 560, also 550, 593
rupestre, 560; Pl. 136
Scenedesmaceae, 272, also 211
Scenedesmus, 273, also 212, 252, 272, 575,
578, 580
abundans, 274; Pl. 61
var. asymmetrica, 274; Pl. 61
var. brevicauda, 274; Pls. 61, 62
var. longicauda, 274; Pl. 62
var. spicatus, 274
acuminatus, 275, also 278; Pl. 62
var. minor, 275
var. tetradesmoides, 275
acutiformis, 275, also 273; Pl. 62 0 |
arcuatus, 275, also 273; Pl. 62
var. capitatus, 275; Pl. 62
var. platydisca, 275; Pl. 62
armatus, 276, also 274; Pl. 62
var. Chodatii, 276
var. major, 276; Pls. 62, 63
var. subalternans, 276 |
—_—s
Bernardii, 276, also 272, 273; Pl. 63 var. undulatum, 228; Pl. 50
bijuga, 276, also 273; Pl. 63 spinulosum, 228; Pls. 50, 53
var. alternans, 277; Pl. 63 Spelaeopogon, 532
var. flexuosus, 277 Sphaerella (See Haematococcus )
var. irregularis, 277 lacustris, 80; Pls. 2, 3
brasiliensis, 277, also 274; Pl. 63 Sphaerellaceae, 80, also 68
denticulatus, 277, also 273; Pl. 63 Sphaerocystis, 83, also 82, 574
var. linearis, 277 Schroeteri, 83, also 88, 240; Pl. 3
dimorphus, 277, also 273; Pl. 63 Sphaeroplea, 111, also 110, 581
hystrix, 278, also 273;-Pl. 63 annulina, 111; Pl. 12
incrassatulus, 278, also 273; Pl. 63 Sphaeropleaceae, 111
var. mononae, 278; Pl. 63 Sphaeropleales, 110, also 66
longus, 278, also 274; Pls. 63, 64 Sphaerozosma, 359
var. brevispina, 278 Spirogyra, 307, also 6, 7, 295, 296, 581, 583
var. ellipticus, 278 aequinoctialis, 310, also 311; Pl. 72
var. minutus, 279 affinis, 311, also 310
var. Naegelii, 279; Pls. 63, 64 Borgeana, 311, also 310; Pl. 77
obliquus, 279, also 273; Pl. 63 borysthenica, 311, also 308
opoliensis, 279, also 274; Pl. 63 catenaeformis, 311, also 310
var. contacta, 279; Pl. 63 circumlineata, 312, also 309; PI. 74
perforatus, 279, also 274; Pl. 46 Collinsii, 312, also 309; Pl. 77
quadricauda, 280, also 274; Pl. 64 communis, 312, also 309
var. longispina, 280; Pl. 63 condensata, 312, also 309; Pl. 72
var. maximus, 280; Pl. 64 crassa, 312, also 28, 48, 310, 314; Pl. 72
var. parvus, 280; Pl. 64 daedalea, 321
var. quadrispina, 280; Pl. 63 daedaleoides, 313, also 309; Pl. 72
var. Westii, 281; Pl. 64 decimina, 313, also 28, 310
serratus, 281, also 273; Pl. 64 dubia, 313, also 310
Schizochlamys, 90, also 87, 574 ellipsospora, 313, also 310; Pl. 72
compacta, 90; Pl. 4 esthonica, 321
delicatula, 90 fallax, 314, also 308; Pl. 77
gelatinosa, 90; Pl. 4 Farlowii, 314, also 308
Schizogoniales, 67 flavescens, 314, also 309
Schizomeridaceae, 104 floridana, 319
Schizomeridineae, 104 fluviatilis, 314, also 310; Pl. 73
Schizomeris, 104, also 581 Fuellebornei, 315, also 310; Pl. 73
Leibleinii, 105; Pl. 7 gracilis, 315, also 309
Schizothrix, 506, also 479, 505, 593 gratiana, 315, also 308; Pl. 74
fasciculata, 507 Grevilleana, 315, also 308; Pl. 74
Friesii, 507, also 506; Pl. 114 illinoisensis, 319
fuscescens, 507, also 506; Pl. 114 inconstans, 315, also 308
lacustris, 507; Pl. 131 inflata, 316, also 308
lardacea, 508, also 506 Juergensii, 316, also 309; Pl. 73
Muelleri, 508, also 506; Pl. 114 jugalis, 316, also 310
rivularis, 508, also 506; Pl. 114 laxa, 316, also 308
tinctoria, 508, also 507; Pl. 131 longata, 316, also 309
vaginata, 509, also 507 majuscula, 317, also 310; Pl. 74
Schroederia, 255, also 234, 578 maxima, 317, also 310, 314
Judayi, 256, also 255; Pl. 57 micropunctata, 317, also 309; Pl. 73
setigera, 256, also 255; Pl. 57 mirabilis, 317, also 309; Pl. 77
Scirpus, 548 nitida, 318, also 310; Pl. 73
Scytonema, 533, also 595 novae-angliae, 318, also 310; Pl. 75
alatum, 534; Pl. 123 orientalis, 318, also 310
Archangelii, 534; Pl. 123 porangabae, 318, also 309; Pl. 77
cincinnatum. See Scytonema crispum porticalis, 318, also 309; Pl. 75
coactile, 534; Pl. 124 pratensis, 319, also 309; Pl. 75
crispum, 535, also 534; Pl. 124 protecta, 319, also 308
figuratum. See Scytonema mirabile pseudofloridana, 319, also 310; Pl. {fe
mirabile, 535, also 533, 534; Pl. 124 reflexa, 319, also 309
var. tolypothricoides. See Scytonema rhizobrachialis, 320, also 310; Pl. 76
tolypothricoides rivularis, 320, also 310
myochrous, 535, also 534; Pls. 124, 125 scrobiculata, 320, also 309; Pl. 76
ocellatum, 25 singularis, 320, also 309
tolypothrichoides, 536, also 534; Pl. 123 Spreeiana, 321, also 308; Pl. 77
Scytonemataceae, 532, also 478, 543 stictica, 321, also 310; Pl. 76
Seepage lakes. See Lakes subsalsa, 321, also 309; Pl. 73
Selenastrum, 256, also 235, 575 suecica, 321, also 309
Bibraianum, 256; Pl. 57 sulcata, 321, also 309
gracile, 257, also 256; Pl. 57 tenuissima, 322, also 308
minutum, 257, also 256; Pl. 46 Teodoresci, 322, also 310
Westii, 257, also 256; Pl. 57 triplicata, 322, also 310
Silicon, 342, 370, 375, 385 varians, 322, also 310; Pl. 76
Siphonales, 266, also 67 Weberi, 322, also 308; Pl. 76
Sirogonium, 296 Spirulina, 479, also 478, 481, 591, 592
Snapping turtle, 47, 143 laxa, 479; Pl. 108
Sodium arsenite, 45 laxissima, 480, also 479; Pl. 107
Soft water lakes. See Lakes major, 480, also 479; Pl. 108
Soils, 5, 8, 11 Nordstedtii, 480, also 479; Pl. 108
Sorastrum, 227, also 219, 577 princeps, 480, also 479; Pl. 108
americanum, 228; Pl. 50 subsalsa, 480, also 479; Pl. 108
[975]
Spondylomoraceae, 79, also 68
Spondylomorum, 79. also 572
quaternarium, 80; Pl. 3
Spongilla, 235
Staurastrum, 18, 938, Pl. 3 (Appendix)
Staurogenia multiseta var. punctata, 285
Stentor, 235
Stephanodiscus, 409, 943, Pl. 5 (Appendix)
niagarae, 11
Stephanosphaera, 81, also 80, 572
pluvialis, 81; Pl. 46
Stichococcus, 98, also 95, 582
bacillaris, 99; Pl. 6
fa. confervoidea, 99
scopulinus, 99; Pl. 6
subtilis, 99; Pl. 6
Stigeoclonium, 114, also 98, 113, 583, 584
attenuatum, 115, also 114; Pl. 13
flagelliferum, 115; Pl. 11
lubricum, 115, also 116; Pl. 10
nanum, 116, also 114; Pl. 9
pachydermum, 116, also 114; Pl. 12
polymorphum, 116, also 114; Pl. 9
stagnatile, 117, also 114; Pl. 11
subsecundum, 117, also 114; Pl. 10
tenue, 117, also 115
Stigonema, 546, also 548, 549, 594
mamillosum, 547; Pl. 130
mesentericum, 548, also 547; Pl. 130
ocellatum, 548, also 547, 594; Pl. 130
tomentosum. See Stigonema ocellatum
turfaceum, 548, also 547; Pl. 129
Stigonemataceae, 543, also 478
Stipitococcaceae, 344
Stipitococcus, 344, also 588
apiculatus, 345, also 344; Pl. 93
capense, 345; Pl. 93
crassistipatus, 345; Pl. 93
urceolatus, 346, also 344; Pl. 93
vasiformis, 346, also 345; Pl. 95
Stylosphaeridium, 91, also 579
stipitatum, 92; Pl. 4
Symploca, 504, also 479, 593
muscorum, 504; Pl. 113
Syncrypta volvox, 374
Syncryptaceae, 374
Synechococcus, 460, also 445, 591
aeruginosus, 461; Pl. 102
Synura, 375, also 19, 590
Adamsii, 375; Pl. 92
uvella, 376, also 374, 375; Pl. 92
var. longipes, 376
Synuraceae, 374
Temnogametum, 296
Temperature, 43
Tetradesmus, 282, also 272, 577
Smithii, 282; Pl. 64
wisconsinense, 283, also 282; Pl. 64
Tetradinium, 440, also 438, 589
javanicum, 440; Pl. 93
simplex, 440; Pl. 107
Tetraédron, 260, also 233, 235, 242, 271,
578, 580
armatum, 262; Pl. 59
arthrodesmiforme, 262, also 261; Pl. 59
var. contorta, 263; Pl. 59
asymmetricum, 263, also 262; Pl. 59
bifurcatum, 263, also 261; Pl. 59
var. minor, 263; Pl. 59
caudatum, 263, also 261; Pl. 59
var. incisum, 263
var. longispinum, 264; Pl. 59
constrictum, 264, also 262; Pl. 59
cruciatum, 264, also 262
var. reductum, 264; Pl. 59
duospinum, 264; Pl. 46
enorme, 265, also 262; Pls. 52, 59
var, pentaedricum, 265; Pl. 59
gigas, 265, also 261
var. granulatum, 265
gracile, 265, also 262; Pl. 60
hastatum, 265, also 262; Pl. 59
var. palatinum, 266; Pl. 59
irregulare, 263
limneticum, 266, also 262; Pl. 60
var. gracile, 266; Pl. 60
lobulatum, 266, also 262; Pl. 60
var. crassum, 266; Pl. 60
var. polyfurcatum, 267; Pl. 60
lunula, 267, also 261; Pl. 60
minimum, 267, also 261; Pl. 60
var. scrobiculatum, 267
muticum, 267, also 261; Pl. 60
fa. punctulatum, 268; Pl. 60
obesum, 268, also 261; Pl. 60
pentaedricum, 268, also 261; Pl. 60
planctonicum, 268, also 262; Pl. 60
pusillum, 268, also 262; Pl. 60
quadratum, 268, also 261; Pl. 46
regulare, 269, also 261; Pl. 60
var. bifurcatum, 269; Pl. 61
var. granulata, 269; Pl. 61
var. incus, 269; Pl. 61
fa. major, 269; Pl. 61
var. torsum, 269; Pl. 61
staurastroides, 271
trigonum, 270, also 261; Pl. 61
var. gracile, 270; Pl. 61
var. papilliferum, 270
var. setigerum. See Treubaria setigerum
tumidulum, 270, also 261; Pl. 61
verrucosum, 270, also 261; Pl. 61
Victoriae, 270, also 261
var. major, 270; Pl. 61
Tetragoniella, 354, also 349, 588
gigas, 354; Pl. 95
Tetrallantos, 287, also 272, 575, 577
Lagerheimii, 287; Pl. 66
Tetraspora, 87, also 89, 126, 236, 573, 574
cylindrica, 88, also 87; Pl. 5
gelatinosa, 88, also 87; Pl. 5
lacustris, 88; Pl. 5
lamellosa, 88, also 87; PI. 5
lubrica, 89, also 88; Pl. 5
Tetrasporaceae, 87, also 82, 475
Tetrasporales, 81, also 66
Tetrastrum, 286, also 272, 576
punctatum, 286
staurogeniaeforme, 286; Pl. 66
Thorea ramosissima, 564
Thoreaceae, 564
Tolypella, 333, also 331, 585
intricata, 334; Pl. 78
Tolypothrix, 536, also 509, 533, 535, 540,
595
conglutinata, 537, also 536; Pl. 125
distorta, 537, also 536; Pl. 125
lanata, 537, also 536; Pl. 125
limbata, 538, also 536; Pl. 126
tenuis, 538, also 536, 537
var. Wartmanniana, 538
Trachelomonas, 407, also 19, 388, 389, 408,
571, 585
abrupta, 410; Pl. 83
acanthostoma, 410, also 408; Pls. 83, 85
aculeata, 408
fa. brevispinosa, 410; Pl. 85
armata, 410, also 409; Pl. 83
fa. inevoluta, 411; Pl. 83
var. longispina, 411; Pl. 83
var. Steinii, 411; Pl. 83
bulla, 411, also 408; Pl. 84
charkowiensis, 411, also 408; Pl. 85
crebea, 411, also 408
var. brevicollaris, 412; Pl. 84.
cylindrica, 412, also 410; Pl. 83
var. punctata. See Trachelomonas
lacustris
[976]
dubia, 412, also 409; Pl. 85
Dybowskii, 412, also 410; Pls. 83, 84
erecta, 412, also 410; Pl. 85
euchlora, 413, also 409; Pl. 89
Girardiana, 413, also 408; Pl. 84
granulosa, 413, also 409; Pl. 89
hexangulata, 413, also 409; Pl. 85
var. repanda, 413; Pl. 84
hispida, 414, also 409; Pl. 83
var. coronata, 414; Pl. 83
var. crenulatocollis fa. recta, 414; Pl. 88
var. papillata, 414; Pl. 84
var. punctata, 414; Pl. 84
horrida, 415, also 408, 409; Pl. 84
intermedia, 415, also 410; Pl. 83
Kelloggii, 415, also 409; Pl. 83
lacustris, 415, also 410; Pls. 83, 85
mammillosa, 415, also 410; Pl. 85
peridiniformis, 415
Playfairii, 416, also 409; Pl. 85
pulchella, 416, also 409; Pl. 83
pulcherrima, 416, also 410; Pl. 83
var. minor, 416; Pl. 83
robusta, 416, also 409; Pl. 83
rotunda, 416, also 409; Pl. 83
scabra var. longicollis, 417, also 408; Pl.
85
similis, 417, also 408; Pls. 84, 85
speciosa, 417, also 408; Pl. 84
spectabilis, 417, also 409; Pl. 85
superba, 417, also 409; Pl. 84
var. duplex, 417; Pl. 84
var. spinosa, 418; Pl. 84
var. Swirenkiana, 418; Pls. 83, 84
sydneyensis, 418, also 409; Pl. 84
triangularis, 418, also 409; Pl. 83
varians, 418, also 409; Pl. 83
volvocina, 419, also 409, 414; Pl. 83
var. compressa, 419; Pl. 83
var. punctata, 419; Pl. 83
Trachychloron, 354, also 349, 588
biconicum, 354; Pl. 95
depauperatum, 355, also 354; Pl. 95
Trentepohlia, 133, also 132, 571, 582, 584
aurea, 133; Pl. 67
var. polycarpa, 134
Tolithus, 134, also 133; Pl. 19
Trentepohliaceae, 132
Treubaria, 241, also 233, 578
setigerum, 242; Pl. 51
Tribonema, 366, also 19, 105, 218, 365,
883, 582, 587
aequale, 368
affine, 367; Pl. 96
bombycinum, 367; Pl. 96
var. tenue, 367; Pl. 96
minus, 368, also 367; Pl. 96
utriculosum, 368, also 367; Pl. 96
viride, 367
Tribonemataceae, 366
Tribonematales, 365
Trichodesmium, 479, 593
lacustre. See Oscillatoria lacustris
Trochiscia, 238, also 234, 579
aspera, 239, also 238; Pl. 53
granulata, 239, also 238; Pl. 53
obtusa, 239, also 238; Pl. 52
reticularis, 239, also 238; Pl. 53
sporoides, 239
Zachariasii, 239, also 238; Pl. 53
Tuomeya, 569, also 586
fluviatilis, 570; Pl. 132
Turtles, 47, 134, 143
Tychoplankton, 3. See also Plankton
Ulothrix, 95, also 94, 98, 582
aequalis, 96, also 95; Pl. 6
cylindricum, 96, also 95; Pl. 6
moniliformis, 102
subconstricta, 96, also 95; Pl. 6
[977]
subtilissima, 96, also 95; Pl. 6
tenerrima, 96, also 95; Pl. 6
tenuissima, 97, also 95; Pl. 67
variabilis, 97, also 95; Pl. 6
zonata, 97, also 95; Pl. 6
Ulotrichaceae, 94
Ulotrichales, 93, also 66
Ulotrichineae, 94
Ulvales, 67
Ulvella, 583
Urococcus, 82
Uroglenopsis, 380, also 376, 590
americana, 380; Pl. 99
Uronema, 98, also 94, 582
elongatum, 98; Pl. 5
Utricularia, 502, 542, 548
Vacuolaria virescens, 421
Vaucheria, 290, also 289, 585
aversa, 291; Pl. 66
geminata, 292, also 291; Pl. 68
var. depressa, 292
hamata, 292, also 291
longipes, 292, also 291; Pl. 67
Nicholsii, 293, also 291; Pl. 67
ornithocephala, 291
orthocarpa, 293, also 291; Pl. 67
pachyderma, 293, also 291; Pl. 67
polysperma, 293, also 291; Pl. 67
sessilis, 294, also 291; Pl. 68
fa. clavata, 294; Pl. 67
terrestris, 294, also 291; Pl. 68
Vaucheriaceae, 289, also 288
Volvocaceae, 73, also 68
Volvocales, 67, also 1, 66
Volvox, 77, also 15, 73, 74, 572
aureus, 78; Pl. 2
globator, 78; Pl. 2
mononae. See Volvox tertius
tertius, 79, also 78; Pl. 3
Water blooms, 7, 17, 44, 376
Westella, 237, also 234, 577
botryoides, 237; Pl. 53
var. major, 237
linearis, 237; Pl. 53
Wollea, 526, also 510, 594
saccata, 526; Pl. 122
Xanthophyceae, 2, 342
Xanthophyll, 421
Zoochlorella, 235, also 233, 236, 579
conductrix, 235; Pl. 53
parasitica, 235; Pl. 53
Zooplankton, 24
Zygnema, 323, also 23, 296, 327, 329, 581
carinatum, 324; Pl. 78
chalybeospermum, 324, also 323; Pl. 74
conspicuum, 324
cyanosporum, 325, also 324
decussatum, 325, also 324
insigne, 325, also 324
leiospermum, 325, also 324; Pl. 78
micropunctatum, 325, also 324; Pl. 78
pectinatum, 325, also 324; Pl. 69
stellinum, 326, also 324
sterile, 326, also 323
synadelphum, 326, also 323; Pl. 74
Zygnemataceae, 295
Zygnematales, 294, also 66
Zygnemopsis, 326, also 296, 581
americana, 327
decussata, 327; Pl. 74
desmidioides, 328, also 327; Pl. 69
minuta, 328, also 327
spiralis, 328, also 327; Pl. 69
Tiffaniana, 328, also 327; Pl. 74
Zygogonium, 329, also 581
ericetorum, 329; Pl. 78
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