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ALBERT R.. MANN LIBRARY 
CORNELL UNIVERSITY 


The Gift of 
THE ESTATE OF 


BRUCE VOELLER 


Cornell University 


Library 


The original of this book is in 
the Cornell University Library. 


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the United States on the use of the text. 


http://www.archive.org/details/cu31924090243449 


; SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE. 
241 


A CONTRIBUTION 


TO THE 


HISTORY OF T 


L 


EK FRESH-WATER ALG 


OF 


NORTH AMERICA. 


BY 
HORATIO C. WOOD, Jr., MD., 
BOTANY, AND CLINICAL LECTURER ON DISEASES OF THE NERVO 


UNIVERSITY OF PENNSYLVANIA; PHYSICIAN TO THE PHILADELPHIA HOSPITAL, ETC. 


a 
[ACCEPTED FOR ‘PUBLICATION, FEBRUARY, 1872.] 


PHILADELPHIA! 
COLLINS, PRINTER, 705 JAYNE STREET. 


ADVERTISEMENT. 


THE following memoir was referred for examination to Dr. John Torrey and Dr. 
F. A. P. Barnard, of Columbia College, New York. ‘They recommended its pub- 
lication provided certain changes were made in the manuscript. These having 
been made by the author, the work is published as a part of the series of « Smith- 
sonian Contributions to Knowledge.” 

JOSEPH HENRY, 
' Secretary, S. . 


WasHINGTON, October, 1872. 


( iii ) 


PREFACE. 


OF all the various branches of Natural History, none has been more enthusias- 
tically and more successfully prosecuted in the United States than Botany. ‘The 
whole field has been most thoroughly occupied, save only as regards certain of the 
lower cryptogams, and amongst the latter, it is the fresh-water Alge which alone 
can be said to have been almost totally neglected. In this fact lies my apology for 
offering to the scientific public the following memoir. 

In doing this, so far from thinking that the work contains no error, I hasten to 
disarm criticism, and to ask with solicitude for a favorable reception, in view 
of the difficulties of the investigation, which I have conducted alone, and almost 
unaided. 

The investigation was first undertaken in connection with my elementary studies 
of Materia Medica and ‘Therapeutics, and has since been prosecuted at intervals 
amidst the distractions of medical teachings and practice, and in some cases with- 
out immediate access to authorities. ‘The field covered is so wide that it is almost 
impossible to exhaust it, and, if it were not for rapidly increasing professional 
engagements, I would gladly devote more time to the subject ; but, as it is, I must 
leave to others to carry on the work thus begun. 

While saying this, it is but just to state that nothing here published has been 
done hastily, but that all is the result of arduous and conscientious investigation. 

A very large part of my material has been of my own gathering, and was 
studied whilst fresh; but I am indebted to several persons for aid by collections. 

First of all, I desire to offer my thanks to Dr. J. S. Billings, U.S. A., and to 
Professor Ravenel, of South Carolina; to the former for assistance in various 
ways, and for collections made near Washington City; to the latter for very large 
collections made in Texas, South Carolina, and Georgia. I am also indebted to 
Mr. C. F. Austin for a large collection gathered in Northern New Jersey, to Mr. 
William Canby for some beautiful specimens obtained in Florida, to Professor 
Sereno Watson for Rocky Mountain plants, and to Dr. Frank Lewis for a number 
of White Mountain desmids. 

These various collections were partly dried and partly preserved in a watery 
solution of carbolic acid or of acetate of alumina, both of which I have found more 
or less satisfactory preservatives. 

The present investigations embrace all families of the fresh-water alge except 
the Diatomacee, which, as every one knows, are so numerous as to constitute in 


C¥) 


a PREFACE. 
themselves a special study. As I have paid no attention to these plants, they are 
of course not included in this memoir. 

In the synonymy I have generally followed Prof. Rabenhorst. ‘The original de- 
scriptions of the forms, especially those of the older authorities, are very frequently 
so meagre and obscure, that the species cannot be recognized by them with any cer- 
tainty. Prof. Rabenhorst has gone over the ground most carefully, with access to 
the whole literature of the subject and probably to all extant type specimens, and his 
decisions are, no doubt, as accurate as the circumstances will allow. To attempt to 
differ from them, to go behind his work to the original sources and make fresh 
interpretations, would cause endless confusion. I have, therefore, nearly always 
contented myself with his dictum, and have referred to him as the authority for the 
names used. 

The following refercnccs were omitted through a misunderstanding from the first 
portion of the text. 

Page 14. Celospherium dubium, Grunnow. RaBenuorst, Flora Europ. Algarum, Sect. I. p. 55. 

“15. Merismopedia convoluta, Br&Bisson. RaBEnHOoRST, Flora Europ. Algarum, Sect. I. p. 58. 

“ 18. Oscillaria chlorina, Kirzinc. Rapenyorst, Flora Europ. Algarum, Sect. I. p. 97. 

“ 18. 0. Fréhlichti, Kitzine. Rapenuorst, Flora: Europ. Algarum, Sect. I. p. 109. 

“ 19. O. nigra, VaucHER. RaxBenuorst, Flora Europ. Algarum, Sect. I. p. 107. 

“ 19. O. imosa, AGARDH. Raxsenuorst, Flora Europ. Algarum, Sect. I. p. 104. 

“ 91. Chthonoblastus repens, Kitzinc. Rasenuorst, Flora Europ. Algarum, Sect. I. p. 132. 

“ 92. Lyngbya muralis, AGarpu. Harvey, Nereis Boreali-Americana, pt. III. p. 104. 

In the text after the “ Habitat,” a name is quoted as the authority therefor; if 
such a name be in brackets, it signifies that the specimens were simply collected by 
such individual, but that the identification was made by some one else; when there 
is not a name uninclosed in brackets, it is meant that the identification was made by 
the author of this memoir. 


Since the present memoir has gone to press, I have received from the author a 
copy of “ Alge Rhodiacee. A list of Rhode Island Alge, collected and prepared 
by Stephen T. Olney, in the years 1846-1848, now distributed from his own her- 
barium.” 

In the introduction to this list, Mr. Olney says: “Of the fresh-water species, I 
have few for distribution. These were obtained mainly in the environs of this 
city, and were placed in twenty-seven small vials in Goadsby’s solution, and sent 
to Prof. Harvey, who submitted them to the judgment of the most learned Eng- 
lish botanist in this particular department, G. H. K. Thwaites, Esq., then of Bris- 
tol, England. ‘The large number of species found in this collection, in so limited 
a range, and collected within a very short period, is surprising, and shows what 
moie persistent collections will develop. I have not time to collate the numerous 
publications of the lamented Prof. Bailey, or I might have made the list of this 
portion of Rhode Island plants more complete.” 

The chlorosperms of this list are as follows :— 


Porphyra vulgaris, AG.-Harv. Ner Bor. Am. 3. 53. Newport. 
Bangia fuscopurpurea, Lynap.-Hary. Ner. Bor. Am. 8.54. Southern Rhode Island. 


PREFACE. vii 


Enieromorpha intestinalis, Lynas.-Harv. Ner. Borr Am. 3. 56. Providence to Newport. 

Enteromorpha compressa, Gruv.-Hary. Ner. Bor. Am. 3. 56. Southern Rhode Island. 

Enteromorpha tlathrata, GRev.-Harv. Ner. Bor. Am. 3. 56. Newport. 

Ulva latissima, L.-Harv. Ner. Bor. Am. 3.59. Providence. 

Ulva lactuca, L.-Harv. Ner. Bor. Am. 3. 60. Providence. 

Tetraspora lacunosa, CHAUV.-Harv. Ner. Bor. Am. 3.61. J. perforata, Battey Mss. Providence. 

Tetraspora lubrica, AG. Providence. 

Batrachospermum pulcherrimum, Hass. Providence. 

Batrachospermum moniliforme, Rotu.-Harv. Ner. Bor. Am. 3. 63. Providence. 

Chetophora endivxfolia, Ac.-Harv. Ner. Bor. Am. 3. 69. Providence. 

Draparnidia glomerata, Ac.-Harv. Ner. Bor. Am. 3. 72. Providence. 

Stigeoclonium minutum, Kurz. Providence. 

Cladophora rupestris, L.-Harv. Ner. Bor. Am. 3. 74. Newport. 

Cladophora glaucescens, GRirr.-Harv. Ner. Bor. Am. 3. 77. Rhode Island. 

Cladophora refracta, Rotu.-Hary. Ner. Bor. Am. 3.79. Southern Rhode Island. 

Cladophora Rudolphiana, Ac.-Harv. Ner. Bor. Am. 3. 80. Providence. 

Cladophora gracilis, Grirr.-Harv. Ner. Bor. Am. 3. 81. Little Compton. 

Cladophora fracta, Harv. Ner. Bor. Am. 3. 82. Rhode Island, Bailey. 

Chetomorpha exrea, Dittw.-Har. Ner. Bor. Am. 3. 86. Newport, etc. 

Chextomorpha Olneyi, Harv. Ner. Bor. Am. 3. 86. Little Compton. 

Chetomorpha longiarticulata, Harv. Ner. Bor. Am. 3. 86. Little Compton. 
var. crassior, Harv. Ner. Bor. Am. 3.86. Little Compton. 

Chetomorpha sutoria, Berk.-Harv. Ner. Bor. Am. 3.87. Newport. 

Zygnema malformatum, Hass. 1.147. Providence. 

Zygnema cateneforme, Hass. 1.147. Providence. 

Zygnema Thwaitesii, OLNEY, n. s. Near Z. subventricosum, Providence. 

Zygnema longatum, Hass. 1.151. Providence. 

Zygnema striata, OLNEY, n. s. “ Cells evidently striated,” Thwaites. Providence. 

Tyndaridea bicornis? Hass. 1. 162. Providence. 

Tyndaridea insignis? Hass. 1. 163. Providence. 

Mesocarpus parvulus, Hass. 1. 169. Providence. 

' Mougeotia genuflexa, Aa.-Hass. 1.173. Providence. 

Vesiculifera concatenata, Hass. 1.201. Providence. 

Vesiculifera xqualis, Hass. 1. 205. Providence. 

Vesiculifera bombycina, Hass. 1. 208. Providence. 

Vesiculifera Candollii, Hass. 1. 208. Providence. 

Bulbochexte Thwaitesii, OLNEY, n. s. Providence. 

Lyngbya majuscula, Harv. Bor. Am. 3.101. Providence. 

Spheroplea virescens, BerK. Providence. 

Spheroplea punctalis, BERK. Providence. 

Tolypothria: distorta, Kirz.-Hass. 1. 240. 

Calothrix confervicola, Ac-Harv. Ner. Bor. Am. 3. 105. Providence. 

Qalothrix scopulorum, Ac.-Harv. Ner. Bor. Am. 3. 105. Providence. 

Hyalotheca dissiliens, Brev.-Ratrs. Des. 51. (Gloeoprium.) Providence. 

Hyalotheca mucosa, Earu.-Raurs. Des. 53. Providence. 

Didymoprium Grevillii, Kivz.-Raurs. Des. 61. Rhode Island, Bailey. 

Didymoprium Borreri, Raurs. Des. 58. Rhode Island, Bailey. 

Desmidium Swartzit, Ac.-Raurs. Des. 61. Throughout United States, Bailey. 

Aptogonum Baileyi, Raurs Des. 209. Worden’s Pond, Rhode Island, Bailey. 

Micrasterias rotata, Raurs. Des. 71. Providence. 

Micrasterias radiosa, Ac.-Raurs. Des. 72. Maine to Virginia, Bailey. 

Micrasterias furcata, Raurs. Des. 73. Worden’s Pond, Rhode Island, Bailey. 

Micrasterias Crusx-Melitensis, Raurs. Des. 73. Maine to Virginia, Bailey. 

Micrasterias truncata, Bres.-Rawrs. Des. 75. United States, Bailey. 


iii PREFACE. 


Micrasterias foliacea, BAtLEY-Ratrs. Desm. 210. Worden’s Pond, Rhode Island, Bailey. 

Micrasterias Bayleyi, Ratrs. Desm. 211. Rhode Island, Bailey. 

Euastrum oblongum, Ratrs. Des. 80. Rhode Island, Bailey. 

Huastrum crassum, Kiitz.-Raurs. Des. 81. Rhode Island, Bailey. 

Huastrum ansatum, Euru.-Rarrs. Des. 85. #. binale Kytz. Providence. 

Euastrum elegans, Kurz.-Ratrs. Des. 89. Providence. 

Euastrum binale, Raurs. Desm. 91. Providence. 

Cosmarium cucumis, CorDA.-RALFS. Desm. 93. United States, Bailey. 

Cosmarium bioculatum, Ratrs. Des. 95. Providence. 

Cosmarium Meneghinti, Brus.-Ratrs. Des. 96. United States, Bailey. 

Cosmarium crenatum, Raurs. Des. 96. Providence. 

Cosmarium amenum, BreB.-RaLrs. Des. 102. Providence. 

Cosmarium ornatum, Raurs. Des. 104. Providence. 

Cosmarium connatum, Bres.-Ratrs. Des. 108. Providence. 

Cosmarium Cucurbita, Ratrs. Des. 109. Providence. 

Cosmarium grandituberculatum, OLNEY, n. s.; “near C. cucumis, but with large tubercles on tho 
frond.” Providence. 

Staurastrum orbiculare, Raurs. Des. 125. Providence. 

Staurastrum hirsutum, Raurs. Des. 127. Providence. 

Staurastrum Hystrix, Raurs. Des. 128. Providence. 

Staurastrum gracile, Raurs. Des. 136. Providence. 

Staurastrum tetracerum, Rates, Des. 137. United States, Bailey. 

Staurastrum cyrtocerum, BREB.-Raurs. Des. 139. Providence. 

Tetmemoras Brébissoni, Raurs. Des. 145. Providence. 

Tetmemoras granulatus, Rautrs. Des. 146. Providence. 

Penium margaritaceum, BREB.-RALFS. Des. (Closterium Eur.) Providence. 

Penium Digitus, Bres.-Raurs. Des. 151. (Closterium lamellosum.) 

Docidium nodulosum, Bres.-Ratrs. Des. 155. Maine to Virginia, Bailey. 

Docidium Baculum, BReB.-Raurs. Des. 158. United States. Bailey. 

Docidium nodosum, Batey-Raurs. Des. 21%. United States, Bailey. 

Docidium constrictum, BatEy-Ratrs Des. 218. Worden’s Pond, Bailey. 

Docidium verrucosum, BatuEy-Ratrs. Des. 218. Rhode Island, Bailey. 

Docidium verticillatum, BAILEY-Raurs. Des. 218. W orden’s Pond, Bailey. 

Closterium Lunula, Hura.-Raurs. Des. 163. New England, Bailey. 

Closterium moniliferum, Kuru.-Raurs. Des. 163. New England, Bailey. 

Closteriiem striolatum, Wuru.-Raurs. Des. 173. New England, Bailey. 

Closterium cuspidatum, BAmLEY-Ratrs. Des. 219. Worden’s Pond, Bailey. 

Pediastrum tetras, Raurs. Des. 182. New England, Bailey. 

Pediastrum heptactis, Ratrs. Des. 183. Providence. 

Pediastrum Boryanum, MEnEGuH.-Raurs. Des. 187. Maine to Mexico, Bailey. 

Pediastrum ellipticum, Hass.-Ratrs. Des. 188. Maine to Virginia, Bailey 

Scenedesmus quadricauda, Bres.-Raurs. Des. 190. Maine to Virginia, Bailey. 

Scenedesmus oblusus, Muyun.-Raurs. Des. 193. Maine to Virginia, Bailey. 


TABLE OF CONTENTS. 


Advertisement ‘ ‘ é 


Preface 


Introduction 


Class PHYcOCHROMOPHYCEE 
Order CystiPpHoR@ 
Family CuroococcacEz 


Order NEMATOGENEE 
Family OscrnuaRIacEm 
Family NostocHacEa 
Family RIvuULARIACE 
Family ScyToNEMACEE 


Family SIROSIPHONACER . 


Class CHLOROPHYLLACE 
Order CoccopHycEz 
Family PALMELLACEs® 
Family PRoTococLacE& 
Family VoLvocinga 


Supplement 


Geographical List of Species. 


Bibliography . 
" Index : i 
Explanation of the Plates 


17 
78 
78 
85 
98 


Order ZyYGoPHYCcEm 
Family DesMiIpIAcER 
Family ZYGneMAcEm 


Order SIPHOPHYCE 
Family HyDRoGssTREz 
Family VAUCHERIACEs 
Family Utvacea& 
Family ConFERVACEs% 
Family GipoconracEa& 
Family CHROOLEPIDE 
Family CH@TOPHORACES 


Class RuoDoPHYcEz® 
Family PorpoyRaces® 


Family CHANTRANSIACES . 


Family BATRACHOSPERMACE 


Family LEMANEACE 


( ix ) 


INTRODUCTION. 


ALTHOUGH beset with difficulties in the outset, no branch of natural science 
offers more attractions, when once the study is fairly entered upon, than the fresh- 
' water alge. The enthusiasm of the student will soon be kindled by the variety 
and beauty of their forms and wonderful life processes, and be kept alive by their 
abundance and accessibility at all seasons of the year; for unlike other plants, the 
winter with them is not a period of counterfeited death, but all seasons, spring, 
summer, autumn, and winter alike, have their own peculiar species. They have 
been found in healthy life in the middle of an icicle, and in the heated waters of 
the boiling spring; they are the last of life alike in the eternal snow of the moun- 
tain summit and the superheated basin of the lowland geyser. 

In their investigation, too, the physiologist can come nearer than in almost any 
other study to life in its simplest forms, watching its processes, measuring its forces, 
and approximating to its mysteries. Sometimes, when my microscope has revealed 
a new world of restless activity and beauty, and some scene of especial interest, as 
the impregnation of an cedogonium, has presented itself to me, I confess the 
enthusiastic pleasure produced has been tempered with a feeling of awe. 

To any on whom through the want of a definite pursuit the hours hang heavy, 
to the physiologist who desires to know cell-life, to any student of nature, I can 
commend most heartily this study as one well worthy of any pains that may be 
spent on it. 

An aquarium will often, in the winter time, give origin to numerous interesting 
forms, but it is not a necessity to the fresh-water algologist; besides his microscope 
and _ its appliances, all that he absolutely needs is a few glass jars or bottles and 
the fields and meadows of his neighborhood. 

The great drawback to the investigation of these plants has been the want of 
accessible books upon them. In the English language there is no general work 
of value, and the various original memoirs are separated so far and wide in the 
Continental and English journals, as to be of but little use to most American 
readers. The Flora Europeum Algarum Aque Dulcis et Submarine, of Prof. Ra- 
benhorst, has done much to facilitate the study, and its cheapness brings it within 
the reach of all. It merely gives, however, brief diagnoses of the various species, 
but with the present memoir will, I trust, suffice for the American student, at least 


until he is very far advanced in his researches. 
1 November, 1871. ( 1 ) 


2 INTRODUCTION. 


A certain amount of experience and knowledge of the subject greatly facilitates 
the collection of these plants, but scarcely so much as in other departments of cryp- 
togamic botany, since most of the species are so small that the most experienced 
algologist does not know how great the reward of the day’s toil may be until he 
places its results under the object glass of his compound microscope. In order to aid 
those desirous of collecting and studying these plants, I do not think I can do 
better than give the following hints as to when and where to find, and how to 
preserve them. 

There are three or four distinct classes of localities, in each of which a different 
set of forms may be looked for. These are: stagnant ditches and pools; springs, 
rivulets, large rivers, and other bodies of pure water; dripping rocks in ravines, 
&c.; trunks of old trees, boards, branches and twigs of living trees, and other 
localities. 

In regard to the first—stagnant waters—in these the most conspicuous forms 
are oscillatorie and zygnemacee. ‘The oscillatoria may almost always be recog- 
nized at once, by their forming dense, slimy strata, floating or attached, gene- 
rally with very fine rays extending from the mass like a long, delicate fringe. 
The stratum is rarely of a bright green color, but is mostly dark; dull greenish, 
blackish, purplish, blue, &c. The oscillatorie are equally valuable as specimens 
at all times and seasons, as their fruit is not known, and the characters defining 
the species do not depend upon the sexual organs. The zygnemas are the bright 
green, evidently filamentous, slimy masses, which float on ditches, or lie in them, 
entangled amongst the water plants, sticks, twigs, &c. They are only of scientific 
value when in fruit, as it is only at such times that they can be determined. 
Excepting in the case of one or two very large forms, it is impossible to tell with 
the naked eye with certainty whether a zygnema is in fruit or not; but there are 
one or two practical points, the remembrance of which will very greatly enhance 
the probable yield of an afternoon’s search. In the first place, the fruiting season 
is in the spring and early summer, the latter part of March, May, and June being 
the months when the collector will be best repaid for looking for this family. 
Again, when these plants are fruiting they lose their bright green color and become 
dingy, often yellowish and very dirty looking—just such specimens as the tyro 
would pass by. The fine, bright, green, handsome masses of these alge are rarely 
worth carrying home. After all, however, much must be left to chance; the best 
way is to gather small quantities from numerous localities, keeping them separate 
until they can be examined. ; 

Adhering to the various larger plants, to floating matters, twigs, stones, &c., in 
ditches, will often be found filamentous alge, which make fine filmy fringes around 
the stems, or on the edges of the leaves; or perchance one may meet with rivularie 
or nostocs, &c., forming little green or brownish balls, or indefinite protuberances 
attached to small stems and leaves. These latter forms are to be looked for 
especially late in the season, and whenever seen should be secured. 

In the latter part of summer, there is often a brownish, gelatinous scum to be 


seen floating on ditches. Portions of this should be preserved, as it frequently con- 
tains interesting nostocs and other plants. 


INTRODUCTION. 3 


In regard to large rivers, the time of year in which I have been most successful 
in such localities is the latter summer months. Springs and small bodies of clear 
water may be searched with a hope of reward at any time of the year when 
they are not actually frozen up. I have found some exceedingly beautiful and 
rare alge in such places as early as March, and in open seasons they may be col- 
lected even earlier than this. ‘The desmids are most abundant in the spring, and 
possibly most beautiful then. They, however, rarely conjugate at that time, and 
the most valuable specimens are therefore to be obtained later—during the summer 
and autumn months; at least,so it is said; and the experience I have had with this 
family seems to confirm it. Rivulets should be watched especially in early spring, 
and during the summer months. 

From the time when the weather first grows cool in the autumn, on until the cold 
weather has fairly set in, and the reign of ice and snow commences, is the period 
during which the alge hunter should search carefully all wet, dripping rocks, for 
specimens. Amongst the stems of wet mosses—in dark, damp crevices, and little 
grottos beneath shelving rocks—is the alge harvest to be reaped at this season. 
Nostocs, palmellas, conjugating desmids, sirosiphons, various unicellular alge, then 
flourish in such localities. My experience has been, that late in the autumn, 
ravines, railroad cuttings, rocky river-banks, &c., reward time and labor better than 
any other localities. 

The vaucherias, which grow frequently on wet ground, as well as submerged, 
fruit in the early spring and summer in this latitude, and are therefore to be col- 
lected at such times, since they are only worth preserving when in fruit. 

In regard to algee which grow on trees, I have found but a single species, and do 
not think they are at all abundant in this latitude. Farther south, if one may 
judge by Professor Ravenel’s collections, they are the most abundant forms. 

Although perhaps of but little interest to the distant collector, yet for the sake 
of those living nearer, I will occupy a few lines with an account of the places 
around Philadelphia which will best repay a search for fresh-water alge. As is 
well known, below the city, there is what is known as the “ Neck,” a perfectly level 
extent of ground lying in the fork between the rapidly approaching rivers, Schuyl- 
kill and Delaware. ‘his is traversed by numerous large ditches, and, especially 
just beyond the city confines, has yielded to me an abundant harvest. My favorite 
route is by the Fifth Street cars to their terminus, then across the country a little 
to the east of south until the large stone barn, known as “Girard’s Barn,” is 
reached. A large ditch lies here on each side of the road, which is to be followed 
until it crosses the Pennsylvania Railroad, then along this to the west, until the 
continuation of Tenth Street crosses it. Here the ditches cease, and the steps are 
to be turned homeward. From Girard’s barn to the crossing just alluded to, 
ditches great and small lie all along and about the route, ditches which have often 
most abundantly rewarded my search, and enabled me to return home richly laden. 
The best season for collecting here is from March to July, and again in October, 
when some of the nostocs may be looked for. 

Crossing the river Delaware to the low country below and above the city of 
Camden, the collector will find himself in a region similar to that just described, 


4 INTRODUCTION. 


and like it cut up by numerous ditches, in which are pretty much the same forms 
as in the “Neck.” But by taking the Camden and Atlantic cars for twenty to 
forty miles into New Jersey to what is known as the “ Pines,” he will get into a 
very different country; low, marshy, sandy grounds, with innumerable pools, and 
streams whose dark waters, amber-colored from the hemlock roots over which they 
pass, flow sluggishly along. I have been.somewhat disappointed in my collections 
in such localities. Fresh-water alge do not appear to flourish in infusion of hem- 
lock, and consequently the streams are very bare of low vegetable life. On the 
other hand, in pools in the more open places, my search has been repaid by find- 
ing some very curious and interesting forms, which apparently are peculiar. 

North of Philadelphia are several places, which at certain seasons will richly 
reward the microscopist. Along the Delaware River, there is a similar country 
and flora to that of the “Neck.” But back from the river things are quite dif 
ferent. The North Pennsylvania Railroad passes near Chelten Hills, some eight 
miles or so from the city, through some deep rock cuttings, which are kept con- 
stantly dripping by numerous minute springs bursting from between the strata. 
At the proper season, these will yield an abundant harvest. Besides these, there 
is also a stream of water with ponds running along by the road, which should be 
looked into. I have seldom had more fruitful trips than some made very early in 
the spring to this locality; but then it was in little pools in the woods, and espe- 
cially in a wooded marsh or meadow to the left of the road, some distance beyond 
the station, that I found the most interesting forms. 

The Schuylkill River and its banks have afforded materials for many hours of 
pleasant work. In the river itself a few very interesting forms have been found; 
but it is especially along its high banks that the harvest has been gathered. 

The dripping rocks and little wood pools in the City Park are well worth visiting; 
but the best locality is the western bank, along the Reading Railroad, above Mana- 
yunk, between it and the upper end of Flat Rock tunnel. Down near the river, at 
the lower end of the latter, will be found a number of beautiful, shaded rocky pools, 
which, in the late summer, are full of Chaetophora and other alge. Along the 
west rocks of the river side of the bluff, through which the tunnel passes, are to 
be found, late in the fall, numerous alge. It is here that the Palmella Jessenit 
grows in such abundance. 

West of the city, in Delaware and Chester Counties, is a well wooded and 
watered, hilly couhtry, in which, here and there, numerous fresh-water alge may 
be picked up. 

As to the preservation of the alge—most of the submerged species are spoiled 
by drying. Studies of them should always, when practicable, be made whilst fresh. 
Circumstances, however, will often prevent this, and I have found that they may 
be preserved for a certain period, say three or four months, without very much 
change, in a strong solution of acetate of alumina. 

An even better preservative, however, and one much more easily obtained, is 
carbolic acid, for I have studied desmids with great satisfaction, which had been 
preserved for five or six years in a watery solution of this substance. In regard 
to the strength of the solution I have no fixed rule. Always simply shaking up | 


INTRODUCTION. 5 


a:few drops of the acid with the water, until the latter is very decidedly impreg- 
nated with it, as indicated by the senses of smell and taste. 

Almost all species of algee which are firm and semi-cartilaginous, or almost 
woody in consistency, are best preserved by simply drying them, and keeping them 
in the ordinary manner for small plants. ‘The fresh-water alge which bear this 
treatment well belong to the Phycochromophycee, such as the Nostocs, Scytonema, 
&c., the true confervas not enduring such treatment at all. When dried plants 
are to be studied, fragments of them should be soaked for a few minutes in warm, 
or for a longer time in cold water. 

The only satisfactory way that alge can be finally prepared for the cabinet is by 
mounting them whole or in portions, according to size, for the microscope. Of the 
best methods of doing this, the present is hardly the time to speak; but a word as 
to the way of cleaning them will not be out of place. Many of them, especially 
the larger filamentous ones, may be washed by holding them fast upon an ordinary 
microscope slide, with a bent needle or a pair of forceps, and allowing water to 
flow or slop over them freely, whilst they are rubbed with a stiffish camel’s-hair 
pencil or brush. In other cases, the best plan is to put a mass of the specimens in 
a bottle half full of water, and shake the whole violently; drawing off the water 
from the plants in some way, and repeating the process with fresh additions of 
water, until the plants are well scoured. At first sight, this process would seem 
exceedingly rough, and liable to spoil the specimens, but I have never seen bad 
results from it, at least when practised with judgment. The water seems so to 
envelop and protect the little plants that they are not injured. 

After all, in many instances it appears impossible to clean these alge without 
utterly ruining and destroying them—the dirt. often seeming to be almost an inte- 
grant portion of them; so that he who despises and rejects mounted specimens, 
simply because they are dirty and unsightly, will often reject that which, scienti- 
tically speaking, is most valuable and attractive. 

In finally mounting these plants, the only proper way is to place them in some 
preservative solution within a cell on a slide. After trial of solution of acetate of 
alumina and various other preservative fluids, I have settled upon a very weak 
solution of carbolic acid, as the best possible liquid to mount these plants in. 
Acetate of alumina would be very satisfactory were it not for the very great 
tendency of the solution to deposit minute granules, and thus spoil the specimens. 
As every one knows, the great difficulty in preserving microscopic objects in the 
moist way is the perverse tendency of the cells to leak, and consequently slowly to 
allow entrance to the air and spoil the specimen. 

As I have frequently found to my great chagrin, the fact that a slide has re- 
mained unchanged for six months, or even a year, is no guarantee that it will remain 
so indefinitely. It becomes, therefore, exceedingly important to find some way of 
putting up microscopic objects that can be relied on for their preservation. Where 
carbolated glycerine jelly or Canada balsam can be used, the solid coating which 
they form around thé specimens constitutes the best known protection. Except in 
the casé of the diatoms, however, these substances so shrivel and distort the fresh- 
water alge immersed in them as to utterly ruin them. I lost so many specimens 


6 INTRODUCTION. 


by the old ways of mounting, that, becoming disheartened, I gave up all idea of 
making a permanent cabinet, until a new cement, invented by Dr. J. G. Hunt, of 
this city, was brought to my notice. This is prepared as follows:— 

“Take damar gum, any quantity, and dissolve it in benzole; the solution may be 
hastened by heat. After obtaining a solution just thick enough to drop readily 
from the brush, add enough of the finest dry oxide of zinc—previously triturated 
in a mortar with a small quantity of benzole—until the solution becomes white 
when thoroughly stirred. If not too much zinc has been added, the solution will 
drop quickly from the brush, flow readily, and dry quickly enough for convenient 
work. It will adhere, if worked properly, when the cell-cover is pressed down, 
even when glycerine is used for the preservative medium. Keep in an alcohol- 
lamp bottle with a tight lid, and secure the brush for applying the cement in the 
lid of the bottle.” 

Its advantages lie in the circumstance, that the glass cover can be placed upon 
the ring of it whilst still fresh and soft, and that in drying, it adheres to both cover 
and slide, so as to form a joint between them of the width of the ring of cement, 
and not, as with asphaltum, gold size, &c., simply at the edge and upon the outside 
of the cover. It is readily to be seen how much less liability to leakage must 
result from this. The method of mounting with it is as follows: A ring of any 
desired size is made, by means of an ordinary Shadbolt’s turn-table, upon a slide, 
which is then placed to one side to dry. When required for use, the specimen, 
cover, &c., being all prepared and ready, the slide is again placed upon the turn- 
table and a new ring of cement put directly upon the old one. The specimen is 
immediately placed within the cell thus formed, and the requisite quantity of the 
carbolated water placed upon it. The cover, which must be large enough to entirely 
or nearly cover the cement ring, is now picked up with the forceps, the under side 
being moistened by the breath to prevent adhesion of air-bubbles, and placed care- 
fully in position. It is now to be carefully and equably pressed down with some 
force. By this, any superfluous water is squeezed out and the cover is forced down 
into the cement which rises as a little ring around its edge. The pressure is best 
made with a stiff needle, at first on the centre and then upon the edges of the cover, 
which may finally be made slowly to revolve underneath the needle point. The 
slide may then be put aside to dry; or, better, an outside ring of the cement thrown 
over its edge in the usual manner. Where a deep cell is required, several coats of 
the cement should be placed one over the other, each being allowed to dry in 
turn. If time be an object, and only a shallow cell be necessary, the first ring of 
cement may be dispensed with, and the whole mounting of the specimen be done 
in a few minutes. Even with this cement and the utmost care in mounting, the 
cabinet should be occasionally inspected, for there will always be some slides into 
which air will penetrate. When such are found, efforts may be made to stop the 
leak by new rings of cement overlaid upon the old, but very often entire remount- 
ing of the specimen is the only satisfactory cure. 

The classification which I have adopted in this memoir is that of Professor Ra- 
benhorst. I have finally selected it, not as being absolutely natural, but as conve- 
nient, and as rarely doing much violence to the natural relations of the various species, 


INTRODUCTION. qd 


Our knowledge of the life-history of the alge must make very many advances 
before the true system can be developed, and abstinence from adding to the present 
numerous classifications is an exhibition of self-control not very common. 

There are, however, certain great groups, which are already plainly foreshadowed, 
and which no doubt will be prominent points in the perfected classification. 
Amongst these are the Conjugate, or those plants in which sexual reproduction 
occurs by the union of two similar cells. In the present paper all the plants of 
this family described are together, since the diatoms are not noticed ; but in Raben- 
horst’s work the latter plants are very widely separated from their fellows, and this 
seems to me the weak point of the Professor’s system. 


FRESH-WATER ALG OF THE UNITED STATES, 


Crass PH YCOCHROMOPHYCE. 


Plante uni- vel multicellulares, in aqua vigentes vel extra aquam in 
muco matricali nidulantes, plerumque familias per cellularum generationes 
successivas ortas formantes. 

Cytioderma non siliceum, combustibile. 

Cytioplasma phycochromate coloratum, nucleo destitutum, granulis 
amylaceis plerumque nullis. 

Propagatio divisione vegetativa, gonidiis immobilibus vel sporis tran- 
quillis. 


Unicellular or multicellular plants living in water, or incased in a mater- 
nal jelly out of it, mostly in families formed from successive generations 
of cells. 

Cytioderm not siliceous, combustible. 

Cytioplasm an endochrome, brown, olivaceous, fuscous, &c., destitute 
of nucleus, mostly without starch granules, 

Propagation by vegetative division, by immovable gonidia or tranquil 
spores. 


The phycochroms are plants at the very bottom of the scale, distinguished by 
the simplicity of their structure and the color of their protoplasm, which, instead 
of being of the beautiful green that marks chlorophyll, is fuscous, or yellowish, 
bluish, brownish, or sometimes particolored, and rarely greenish, but of a shade 
very distinct from the chlorophyll green, more lurid, bluish or yellowish, or oliva- 
ceous in its hue. The nucleus appears to be always wanting. ‘The cell wall is 
oftentimes distinct and sharply defined, but in many instances it is not so, the 
walls of different cells. being fused together into a common jelly in which they are 
imbedded. In a large suborder the wall is replaced by a sheath, which in some 
genera surrounds cells with distinct walls, in others, cells without distinct walls, 
and in still others, a long cylindrical mass of endochrome, which may be looked 
upon as a single cell. 

Many of the phycochroms are unicellular plants in the strictest sense of the word, 
but more often the cells are conjoined, so as to form little families, each cell of 
which is in a sense a distinct individual capable of separate life, yet the whole 


bound together into a composite individual. Rarely the phycochrom is a multi- 
2 January, 1872. , (9) 


10 FRESH-WATER ALG#Z OF THE UNITED STATES. 


cellular plant in the stricter use of the term. Increase takes place by the multipli- 
cation of cells by division, and also by the formation of enlarged thick-walled cells, 
to which the name of spores has been given, although it is entirely uncertain 
whether they are or are not the result of sexual action. There are numerous 
peculiar forms of cell multiplication by division occurring in these plants, the dis- 
cussion of which will be found scattered through the remarks on the various 
families and genera. 

The method of reproduction, and in fact the life history in general, of the phy- 
cochroms, is still involved in such mystery, that I am not aware that absolute 
sexual generation has been demonstrated in any of them. This being the case, it is 
not to be wondered at that many have conjectured as possible, and some have roundly 
asserted as true, that the phycochroms are merely stages in the life history of higher 
plants; that they are not species, and, consequently, that any attempt at describing 
such is little more than a busy idleness. In regard to some of them it has certainly 
been rendered very probable that they are merely fixed stages of higher plants. 
On the other hand, in the great bulk of the forms, no proof whatever has been 
given that they are such. ‘They all certainly have fixed, definite characters, capa- 
ble of being expressed and compared, so that the different forms can be defined, 
recognized, and distinguished. If, therefore, future discoveries should degrade 
them as subordinate forms, names will still be required, and definitions still be 
necessary to distinguish them one from the other, so long as they are common 
objects to the microscopist. 

If Nostoc commune, for example, were proven to be a peculiar state or develop- 
ment of Polytricum commune, I conceive it would be still known as Nostoc commune. 
But, as previously stated, no proof whatever has as yet been furnished for the vast 
majority of the plants of this family, to show that they bear any such relation to 
higher plants; and until some such proof is forthcoming, certainly the only scien- 
tific way to act, is to treat them as distinct species, 


Orver Cystiphore. 

Plante unicellulares. Cellule singule vel plures in familias consociate. 

Unicellular plants. Cells single or consociated in families. 

In this order the cells are oblong, cylindrical, spherical, or angular. They are 
sometimes single, or more commonly are united by a common jelly into families, 
which sometimes are surrounded by distinct coats. ‘The mucus or jelly, in which 
the cells are imbedded, is mostly, but not always, colorless, and varies in firmness 


from semifluid to cartilaginous. The division of the cells may take place either in 
one, two, or three directions or planes. 


Fasmty CHROOCOCCACEA. 


Character idem ac ordine. 


Characters those of the order. 


FRESH-WATER ALG& OF THE UNITED STATES. 11 


Genus CHROOCOCCUS, Naceut. 


Cellule globose ovales vel a pressione mutua plus minus angulose, solitarie vel in familias con- 
Sociate, libere (a vesica matricali non involute) ; cytiodermate achromatico, homogeneo, sepe in muco 
plus minus firmo confluente; cytioplasmate eruginoso vel pallide ceruleo-viridi, non rare luteolo vel 


aurantiaco, interdum purpurascente. Generationum successivarum divisio alternatim ad directiones 
tres. 


Syn.—Protococcus, AG. et Krz., &c., ex parte. Plewrococcus, Munau. 
lobuline et Protospherix, TuRPIN, ex part. 


Cells globose, oval, or from mutual pressure more or less angular, solitary, or consociated in free 
families (not involved in a maternal vesicle); Cytioderm achromatic, homogeneous, often confluent 
into a more or less firm mucus; cytioplasm eruginous or pale bluish-green, not rarely yellowish or 
orange, sometimes purplish. Successive generations arising by alternate division in three directions. 
Cc. refractus, Woon. 


C. cellulis in familias solidas arcte consociatis, plerumque subquadratis, sepius triangularibus, 
rare angulosis; familiis sepius lobatis; cytiodermate tenui, vix visibile, achroo; cytioplas- 
mate subtiliter granulato, subfusco vel subluteo vel olivaceo, valde refrangente. 

Diam.—Cell gpon/’—sy'on'’, rare in cellulis singulis sggq/’; famil. pAyg”/—i 49". 

Syn.—C. refractus, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, 122. 

Hab.—In rupibus irroratis prope Philadelphia. 


Cells closely associated together into solid families, mostly subquadrate, very often triangular, 
rarely multiangular; families often lobed; cytioderm thin, scarcely perceptible, transparent ; 
cytioplasm finely granular, brownish, olivaceous, or yellowish, highly refractive. 


Remarks.—The color of this species varies from a marked almost fuscous brown 
to a light yellowish-brown, the lighter tints being the most common. The cells 
are remarkable for their powerful refraction of the light, resembling often oil as 
seen under the microscope, especially if they be the least out of the focus. They 
are very closely joined together to form the families, many of which are composed 
only of four cells. Often, however, a large number of the cells are fused together 
into a large, irregular, more or less lobate family, and these sometimes are closely 
joined together into great irregular masses. J have occasionally seen large single 
cells with very thick coats, whose protoplasm was evidently undergoing division. 
Are such a sort of resting spore? The color of the protoplasm varies. Perhaps the 
more common hue is a sort of clay tint. Bluish-olive and a very faint yellowish- 
brown are not rarely seen. The species grows abundantly on the wet rocks along 
the Reading Railroad between Manayunk and the Flat Rock tunnel. 

Fig. 5, pl. 5, represents different forms of this species; those marked a, magnified 
750 diameters; 6, 470 diameters; c, 950 diameters. 


Cc. multicoloratus, Woop. 

C. in strato mucoso inter algas varias sparsus; cellulis singulis et sphericis, vel 2-4 (rare 8) aut 
angulis aut semisphericis aut abnormibus in familias oblongas consociatis; cytiodermate crasso, 
hyalino, haud Jamelloso; tegumentis plerumque nullis, interdum subnullis; cytioplasmate ple- 
rumque homogeneo, interdum subtiliter granulato, vel luteo-viride vel cwruleo-viride vel luteo 
vel subnigro, vel brunneo, vel saturate aurantiaco, seepe ostro tincto. 


Diam.—Cell., sing. sine tegm., gyyy’’ cum teg. yPg5’’5 cell. in famil. sing. geyy"—aey5-” 
wt av. 6 7 tt 
Fam. long. gg00/’—a00 5 lat. gs'00"—as'00"- 


12 FRESH-WATER ALG#& OF THE UNITED STATES, 


Syn.—C. multicoloratus, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, 122. 
Hab.—in rupibus humidis prope Philadelphia. 


C. occurring scattered in a mucous stratum with other algez; cells spherical and single, or else 
angular semi-spherical or irregular and associated together in oblong families of from 2-4 
(rarely 8); inner coat thick, hyaline, not lamellate; outer coat generally wanting, sometimes 
indistinctly present; endochrome mostly homogeneous, sometimes minutely granular, either a 
yellowish-green or bluish-green, or yellowish or brown, or blackish, sometimes tinged with 
bright lake. 


The cells of this species do not appear to have any tendency to unite to form 
large masses or fronds. On the contrary they are generally very distinct. Their 
color varies very much, in a larger number of instances they were a decided yellow- 
ish-green, tinged at some point or other with a beautiful lake. When several cells 
are formed by division out of one cell, a similar division of the very thick surround- 
ing gelatinous coat follows separating them finally entirely one from the other. I 
have seen a single cell which appears to be an encysted form of this, of which I give 
a drawing. 

Fig. 6, pl. 5, represents different forms of this species magnified 260 diameters. 


Cc. thermophilus, Woop. 

C. cellulis singulis aut geminis vel quadrigeminis et in familias consociatis, oblongis vel sub- 
globosis, interdum angulosis, haud stratum mucosum formantibus; tegumento crassissimo, 
achroo, haud lamelloso, homogeneo; cytioplasmate viride, interdum subtiliter granulato, inter- 
dum homogeneo. 

Diam.—Cellule singule sine tegumento longitudo maximayz?5y”’, latitudo maxima gy’. 

Syn.— C. thermophilus, Woop, American Journal Science and Arts, 1869. 

Hab.—Benton Springs, Owen Co., California (Mrs. Parz.). 3 

Cells single, geminate, or quadrigeminate and consociated into families, oblong or subglobose, 
sometimes angular, not forming a mucous stratum; tegument very thick, transparent, not 
lamellate, homogeneous; cytioplasm green, sometimes minutely granulate, sometimes homo- 
geneous. 


Remarks.—Remarks upon this species will be found under the head of Nostoc 
calidarium, W ood. 


Genus GLOEOCAPSA, Krz. 


“ Cellule spherice aut singule aut numerose in familias consociate; singule tegumento vesiculi- 
forme (cytiodermate tumido) incluse, post divisionem spontaneam in cellulas duas filiales facta 
utraque tegumento se induit, dam ambe tegumento matricali involute remanent; cellularum harum 
filialium iterum in duas cellulas divisione continuo repetita, tegumentum atavie restat et sese exten- 
dens familiam totam cireumvelat. Cytioderma crassum, sepe crassissimum, cellule lumen crassitie 
equans vel superans, achromaticum vel coloratum, plerumque lamellosum; lamelle vel strata non 
raro discedentia. Cytioplasma eruginosum, ceruleo-viride, chalybeum, rufescens, luteo-fuscum, &e. 
Cellularum divisio directione ad tres dimensiones alternante. Cellule generationum ultimarom 
minores quam priorum sunt.” (Rab.) 


Syn.—Globulina et Bichatia, Turpin, ex part. 
Gloeocapsa, Krz., ex part. 
Microcystis, Menzau., ex part. 


Cells spherical, either single or associated in numbers into families; the single cell included a 
vesiculiform tegumeht (the tumid cytioderm); this cell then undergoing division into two daughter- 


FRESH-WATER ALG& OF THE UNITED STATES. 18 


cells, each of which has a distinct tegument, the whole being surrounded with that of the old mother- 
cell. This process of division is then repeated again and again, the original cell-wall remaining and 
surrounding the family thus formed. Cytioderm thick, often very thick, equalling, or exceeding in 
diameter the cavity of the cell, achromatic or colored, mostly lamellated, lamelle or strata not rarely 
separating. Cytioplasm of various colors, eruginous, bluish-green, chalybeate, reddish, yellowish- 
fuscous, &c. Division of the cells occurring in three directions. The last generation of cells smaller 
than the earlier ones. 


G. sparsa, Woop. 
G. in strato mucoso sociis algis variis sparsa; cellulis sphericis, vel oblongis vel ovatis, 2-8 in 
familias consociatis; familiis subglobosis vel subovatis, interdum numeroso-aggregatis; tegu- 
mentis internis aureofuscis, firmis, rarissime coloris expertibus, homogeneis, vel lamellosis; 


tegumentis externis achromaticis, rare subachromaticis, plerumque vix visibilibus; cytioplas- 
mate homogeneo. 


Diam.—Max. cell. oblong. sine tegum. long., gqg9’’; lat., zz'op’’; cell. glob., sine tegum., 
sooo 5 cum tegum., ygzg’’; fam., 739”. 

Syn.—G. sparsa, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, 123. 

Hab.—In rupibus irroratis prope Philadelphia. 


G. scattered in a mucous stratum composed of various alge; cells spherical, or oblong, or ovate, 
associated together in families of from 2-8; families subglobose or subovate, sometimes aggre- 
gated together in large numbers; inner tegument yellowish-brown, firm, rarely colorless, homo- 
geneous or lamellate; external tegument achromatic, rarely subachromatic, generally scarcely 
visible. 


Remarks.—This species was found in a rather firm, grumous or gelatinous coat- 
ing of a light brown color, growing on the rocks at Fairmount Water Works, 
chiefly composed of a very minute nostochaceous plant, but contained numerous 
other alge. The color of the tegument is yellowish-brown, sometimes with some 
red in it, sometimes with something of a greenish tint. This inner colored coat 
is not generally more than once or twice lamellate, often it is not at all so. This 
species seems somewhat allied to G. styophila, but differs slightly in the form of 
the cell, and more especially in not having a distinct thallus, and in the families 
being small and containing but few cells. 

Fig. 7, pl. 8, represents this species, magnified 750 diameters, 


Genus CAXLOSPH/ERIUM, N «cE. 


Thallus parvus, e cellulis minimis in familias periphericas consociatis vel in stratum periphericum 
simplex et in muco tegumentis celerrime confluentibus formato nidulantibus compositus, Cellu- 
larum divisio, initio generationum serierum, in omnem fit directionem, tum denique alternatim 
ad superficiei spheric utramque directionem. 


Thallus small, composed of very small cells consociated into peripheral families, or in a simple 
peripheral layer, inclosed in their quickly confluent teguments. Division of the cells at first in all 
directions, afterwards only in each direction on the surface of the sphere. 


C. dubium, Gron.? 
i C. thallo microscopico, subgloboso vel enorme, natante, congregato; cellulis globosis aut sub- 
globosis; cytioplasmate pallide erugineo, subtiliter granulato. 


Diam.—Cell. plerumque gayy’’ = -00016”; rare ggoq”” = .00025”; fam. yo %og—rstyg” = 
.00083/’—. 0033’’. 


14 FRESH-WATER ALG& OF THE UNITED STATES. 


Hab.—In aquis stagnis, prope Philadelphia. 


Thallus microscopic, subglobose or irregular, floating, aggregated in great numbers; cells glo- 
bose or subglobose; cytioplasm finely granulate, pale eruginous green. 


Remarks.—I found this beautiful little plant forming a dense scum on a stag- 
nant brick-pond, below the city, in the month of July. The scum was of the 
“color of pea-soup,” and so thick was it, that I think a quart of the plants might 
have been readily gathered. The fronds were of various sizes, and many of them 
were apparently undergoing division—some of them seemed to have little fronds 
in their interior. They were composed of an exceedingly transparent firm jelly, in 
which the cells were placed, often so as to leave the central parts of the frond 
empty, merely forming a sort of filament-like layer around the edge. Rarely they 
were in such numbers as to be crowded together over the whole surface of the 
frond. In some of the younger fronds the cells formed a little ball within the jelly, 
instead of being scattered through its outer portion. I have seen some large single 
cells three or four times the size of the ordinary frond cell, swimming amongst the 
plants, of which they are apparently the reproductive gonidia. Their cell-coats 
are very firm and thick. The fronds themselves are often closely aggregated 
together into little masses, and I think it probable that there is a state of the 
plant, in which the jelly becomes softened and the fronds more or less fused together 
in protococcus-like masses. This plant appears to be the same as the European C. 
dubiwm, but differs from ‘the description in the fronds not attaining to anything 
like the size. It is very prabable, however, that this depends upon age or circum- 
stances of growth, and that American plants may be found as large as the 
European. 


Genus MERISMOPEDIA, Meyen. 


Cellule globose, aut oblonge, aut ovales, tegumentis confluentibus, 4, 8, 16, 32, 64, 128 in fami- 
lias tabulatas, unistratas consociate. Thallus planus, tenuis, plus minus quadratus, in aqua libere 
natans. Cellularum divisio in planitiei utramque directionem. 


Cells globose, oblong, or oval, joined together by their confluent coats into tabular families of 4, 
8, 16, 32, 64, 128. Thallus, a more or less quadrate plane, swimming free in the water. Division 
of the cells occurring in all directions in the one plane. 


M. nova, Woop. 


M. thallo membranaceo, distincte limitato, cellulis numerosissimis composito; cellulis ovalibus, 
arcte approximatis, 16 in familias consociatis, dilute ceruleo-viridibus, interdum medio con- 
strictis; thalli marginibus rectis, integris. 


Syn.—M. nova, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, 123. 
Diam.—Cell. ad. gghy5’’ = 0.0025”. 
Hab.—In flumine Schuylkill, prope Philadelphia. 


Thallus membranaceous, distinctly limited, composed of very numerous cells; cells oval, closely 


approximated, consociate in families of 16, light bluish-green, sometimes constricted in the 
middle; margin of the thallus straight and entire. 


Feemarks—Mhe only specimens I have ever seen of this species were found grow- 
ing in the Schuytkill River adherent to, or entangled in, a lot of filamentous algee. 


FRESH-WATER ALG# OF THE UNITED STATES. 15 


The frond is very sharply defined, and, under a low power, is of a uniform bluish- 
green tint. The cells are associated in primary families of 16, of a number of 
which the thallus is composed. The species appears to be most closely allied to 
M. mediterranea, Neeg., from which it differs very essentially in the size of the fronds, 
and perhaps even more closely to M. glauca, the only character separating it from 
which is the straight margin. I have myself some doubts whether it ought not to 
be considered as merely a form of M. glauca. 
Fig. 8, pl. 8, represents this species, magnified 400 diameters. 


M. convoluta, Brzs. 

M. thallo membranaceo, oculis nudis visibili, plus minus convoluto; familiis e cellulis geminis et 
in subfamilias dispositis, 256 compositis, interdum familiis duabus in familia gemina conjunc- 
tis; cellulis sphericis aut oblongis; cytioplasmate homogeneo, viridi. 

Diam.—Cell. gggq'’ = 0.00017’; fam. long. ,3y’' = .06''; lat. g35’7 = 0.04’. 

Hab.—In aquis quietis prope Philadelphia. 

Thallus membranous, visible to the naked eye, more or less folded; families composed of 256 


geminate cells, arranged in subfamilies, sometimes two of these families conjoined with a com- 
\ posite family ; cells spherical or oblong; cytioplasm homogeneous, green. 


“Remarks.—When my Prodromus was published, the only specimens of this plant 
which I had seen were contained in a mounted slide given me by my friend Dr. J. 
Gibbons Hunt, of this city. Since then I have found it growing in a very shallow, 
quiet, but fresh, sweet pool at Spring Mills, making a distinct green layer upon the 
mud many feet inextent. Of course, there were millions of specimens in this layer. 
The fronds are irregular in shape, often somewhat ovate, sometimes subquadrate, 
variously torn, and not rarely somewhat lobate. Their edges are frequently very 
sharply defined and rendered firm and prominent by several rows of cells being 
crowded closely together along them. The cells in the body of the frond are arranged 
in large parallelogrammatic families, composed of 256 cells. There are 16 cells on 
each side, the families being parallelogrammatic rather than square, owing to the 
oblong shape of the cells. This cell family is composed of four subfamilies, each 
containing 64 cells. These are again subdivisible into four more or less distinct 
groups of 16 cells each. The cells are, finally, generally closely geminate, each 
pair being very distinctly separated from its neighbors. In certain stages of growth, 
as immediately after a general division of the cells, two of the large cell-families 
spoken of are often temporarily joined together to form a huge family of 512 cells, 
but soon separate one from the other. 


Orpen Nematogenez. 


Plante multicellulares vel pseudo-multicellulares. Cellule filum (trichoma) formantes et ple- 
rumque vagina tubulosa homogenea vel lamellosa incluse. Trichomata aut simplicia aut ramificata. 


Plants multicellular or pseudo-multicellular. Cells forming a filament, and generally included in 
a tubular lametlate or homogeneous sheath. Filaments either simple or branched. 


16 FRESH-WATER ALGA OF THE UNITED STATRS, 


Famity OSCILLARIACE.A. 


Trichomata simplicia haud vero multicellularia, sed distincte articulata, plerumque vaginata, mo- 
tionibus variis predita. 

Filaments simple, not strictly multicellular, but distinctly articulate, mostly vaginate, moving in 
various ways. 


Genus OSCILLARIA, Bosc. 


Trichomata simplicia, plerumque distincte articulata, rigida, recte vel parum curvata, rarius cir- 
cinata vel spiraliter convoluta, plerumque lete colorata, motu triplici pedita, in muco matricali 
nidulantia vel vaginula tubulosa angustissima utroque fine aperta inclusa; articuli fronte disciformes. 


(B.) 


Filaments simple, mostly distinctly articulate, rigid, straight, or somewhat curved, very rarely 
circinate or spirally convolute, capable of three motions, floating in a maternal jelly, and shut up 
in a fine tubular sheath, open at both ends; joints from the front disciform. 


The oscillaria are very peculiar plants, which flourish almost in every situation 
in which fresh water is to be found. ‘The purest springs are not always free from 
their presence, although they occur most abundantly in stagnant pools and ditches, 
where animal or vegetable matters are undergoing decay. When viewed in mass, 
floating upon some foul pool, few objects in the vegetable world are better calcu- ~ 
lated to excite disgust. A dark, slimy scum recking with its putrescent surround- 
ings, they seem to offer nothing of pleasure or interest. But, when brought home 
to the table of the microscopist and placed beneath his object-glass, they startle 
the observer by the wonders of their life-history. Living rods, writhing, twisting, 
bending, curling, creeping, gliding hither and thither; incessant, apparently cause- 
less, motion, occurring too in what to most minds is the very type of fixity and 
passivity—a plant. No marvel, then, that they are so famous. 

The structure of an oscillatoria is about as simple as it can be. An outside 
colorless cellulose sheath, which is probably in the uninjured filament closed at the 
end, although, as seen by the microscope, violence and age have often torn it open. 
Within is a long rod of variously colored endochrome, distinctly articulated by, at 
great or less intervals, breaks in the color, which appear as dark lines under a low 
power, but, under a higher objective, are revealed as narrow linear portions of 
protoplasm lighter and more transparent than the rest. Frequently at the joints 
there is a marked tendency to separation between the successive articles, and a very 
decided contraction of the endochrome on each side, so as to leave a little gutter, 
or dividing trench. The endochrome is sometimes homogeneous, sometimes con- 
tains numerous granules, which are, however, never amyloid in their nature, 

The color of the endochrome varies very greatly in the different species. Slate 
color, blue, greenish, olivaceous, are among the most common hues. According 
to Dr. Ferdinand Cohn (Botan. Zeitung, 1867, p. 38; Sitzung, 13th Dec. 1866, 
der Schlesischen Gesellschaft fiir vaterlandische Cultur), the coloring matter of the 
oscillatoria consists of true chlorophyll, and a substance which he calls Phycocyan, 
but which he states to be different from Phykokyan of Kiitzing, the Phychochrom 
of Negeli, and also from Phycocyan of the latter authority. ‘The chlorophyll is, 


FRESHWATER ALG#A OF THE UNITED STATES. 17 


of course, soluble in ether and alcohol but not in water; but the Phycocyan (Cohn) 
is insoluble in alcohol and ether, but soluble in water after the death of the oscil- 
latoria. Itis precipitated out of its solution by acids, alcohol, and metallic salts, 
as a blue jelly, but potash and ammonia throw it down as ina colorless, gelatinous 
mass. I have myself frequently noticed that oscillatoria after death will yield a 
bluish coloring matter to water, but thought that such coloring matter was the 
result of a partial decomposition, and I think that Professor Cohn has by no means 
established as a fact that his Phycocyan exists in the oscillatoria during life. 

As to the method of reproduction of these plants, we are as yet almost entirely 
in the dark. Individuals do multiply by the breaking up of the internal endo- 
chrome into masses or sections through a separation at the joints. These little 
masses frequently grow immediately into new individuals. Sometimes, however, 
they roll themselves into a ball, but whether they then have the power of coating 
themselves with a protective wall and passing into a sort of resting spore or not, I 
cannot say. 

The specific characters of the oscillatoria are derived from the color, form, mode, 
and place of growth, &c., of the large common mass, its thickness, consistency, 
the absence or presence of radii, &c. Descending to the individual filament, the 
characters are drawn from the size, the color, the length of the articulations, and 
the shape of the uninjured ends. Thus, it is to be noted, whether the latter are 
gradually narrowed (attenuated), or preserve their size to the very point, whether 
they are acutish or obtuse, rounded or truncate, whether they are straight or con- 
stantly curled. The activity and modes of motion are also to be remarked. Some 
species merely glide across the field of the microscope, some are constantly curling 
and uncurling at their ends, some bending to and fro almost like a pendulum, some 
are very sluggish, others very active and restless. 

After all, however, it must be confessed that the specific characters are very un- 
satisfactory, much more so than in any other phycochroms which I have studied. 

A very large number of European forms have been described, some few of which 
I have been able to recognize. I have also ventured to name a few forms appa- 
rently distinct, but have refrained from going. farther into their specific study, 
because I have found it so unenticing, and my time has been so limited. 

Professor Bailey, in Silliman’s Journal, N. S., vol. iii., states that he has identified 
a few species of this family, although with great hesitation and doubt. At the 
time he wrote there were really no known grounds upon which specific unity could 
be predicated in these plants, and I therefore think that his identifications are of 
but little value, although holding the most profound respect for his abilities as a 
naturalist. The list he gives is as follows :— 

O. tenuissima, Ag. Warm Springs of Washita. 

O. tenuis, Ag. Providence, Rhode Island. West Point, New York. Culpepper 
County, Virginia. 

. ©. decorticans, Gener. Common everywhere on pumps, &c. 
O. muscorum, Ag. West Point, New York. 

O. nigra, Vauch. West Point, New York. 

O. corium, Ag. 


3 February, 1872. 


18 FRESH-WATER ALG# OF THE UNITED STATES. 


O. chlorina, Kiirzine. 

O. interdum in strato sordide viridi natante, interdum in aqua diffusa; trichomatibus rectis, 
vivide moventibus, vel articulatis et cum cytioplasmate granulato, vel inarticulatis et cum 
cytioplasmate haud granulato; cytioplasmate hyalino, interdum coloris fere expertibus, 
interdum dilutissime viride; apiculo haud attenuato, obtuse rotundato, recto; articulis dia- 


metro subeequalibus. 
Diam.—zgo50''—sdo0'’ = .00014'’—.0001'". 


Hab.—In stagnis prope Philadelphia. 


Sometimes swimming on the water as a dirty-greenish stratum, sometimes diffused in the water; 
filaments straight, actively moving, either articulated and having the cytioplasm filled with 
blackish granules, or else neither articulate nor granulate, cytioplasm hyaline, almost colorless, 
or with a faint greenish tint; ends of the filaments not attenuate, straight, obtusely rounded ; 


joints about equal to the diameter. 


Remarks.—I found this species in the month of August, 1869, in one of the 
stagnant brick-ponds below the city. It occurred as a sort of floating scum, or 
else diffused through the water, which was then opaque and greenish. It resembled 
so a protococcus in gross appearance that I did not think of its being an oscilla- 
toria until I placed it under the microscope. The filaments are almost colorless, 
and, in most instances, are very distinctly granulate and articulate. The dissepi- 
ments are in such cases clear and transparent, perfectly free from granules. This 
form is very close to the descriptions of the European O. chlorina, Ktz., but differs 
somewhat from descriptions, chiefly in habit of growth. The filaments, when in 
mass, are often seen to be curved under the restraining force of the glass cover, 
but when free I think always straighten themselves. 

Fig. 1, pl. 1, represents a single filament, magnified 750 diameters, 


0. Frohlichii, K1z.? 
O. strato indefinito, tenue, viride; trichomatibus lete viridibus, subrectis, vivide oscillantibus, 
ad genicula nonnihil pellucidis et leviter contractis et rarissime granulatis; articulis diametro 
2, 3, 4 plo brevioribus; cytioplasmate obscure aut distincte minutissime granulato ; apiculo 
haud attenuato, late rotundato. 


Diam.—z¢55' '— B50 a 0. 00066’ ‘0. 0004. 
Hab.—In flumine Schuylkill. 


Stratum indefinite, thin, green; filaments bright green, straightish, vividly oscillating, some- 
what pellucid at the joints, where they are slightly contracted and very rarely granulate ; 
articles 2, 3, 4 times shorter than the diameter, cytioplasm obscurely or distinctly very mi- 
nutely granulate; apex not attenuate, broadly rounded. 


Remarks.—I found this species growing upon the bottoms of the shallows in the 
Schuylkill River and its larger tributaries, forming a somewhat badly defined 
stratum, rather, indeed, a coating on the mud than a definite stratum. ‘The motion 
is exceedingly active, the filaments bending and gliding, and their apices con- 
stantly curling and extending in all directions. The apices are very blunt. The 
filaments are not often seen woven and twisted together into a mass composed 
simply of themselves, but are stuck together loosely, each filament remaining 
straightish, with numerous little masses of mud between them. I have not been 


FRESH-WATER ALGA OF THE UNITED STATES. 19 


able to identify the species positively, but have referred it with doubt to O. Fréhli- 
chit. : 
Fig. 2, pl. 1, represents the end of a filament. 


O. nigra, VavucuH. 

O. strato plus minus compacto, amplo, plerumque natante, atro-viride, cum radiis longis; tricho- 
matibus plerumque flexuosis; apice obtuse rotundato; articulis diametro 3 plo brevioribus; 
dissepimentis distincte granulatis; cytioplasmate pallide ceesio. 

Diam.—33'55''—a0 50": 

Hab.—In fossis stagnis prope Philadelphia. 

Stratum more or less compact, ample, broad, mostly floating, blackish-green, with long radii; 


filaments mostly flexuous; apices obtusely rounded; joints 2 shorter than broad; dissepi- 
nents distinctly granulate; cytioplasm pale-grayish. 


Remarks—This species is found in thick, rather loose strata, floating, especially 
when old, on stagnant waters, or adhering to plants, &c., or the muddy shores and 
bottom of ditches, foul aquaria, &c. The color of the stratum is a very dark 
blackish-green, with a peculiar, glossy, repulsive appearance. ‘The single filaments 
are of a pale-bluish neutral tint, sometimes a little greenish, very much curved 
and entangled, or more rarely straightish. Their motion is active. ‘The measure- 
ments do not quite equal those given by European authorities, but otherwise the 
plant agrees well with their descriptions. 

Fig. 3a, pl. 1, represents the mass of the plant as seen with the naked eye; fig. 
3b, shows a number of filaments slightly magnified; fig. 1c, a broken portion of a 
filament magnified 260 diameters, with the sheath projecting beyond the endo- 
chrome; fig. 1d, the end of a filament still more highly magnified. 


O. limosa, Acarpz. 

O. trichomatibus subrigidis et subrectis, vivide oscillantibus, ceruleo-viridibus, in stratum muco- 
sum Jeete saturate viride et modice longe radians et natans collectis et intertextis, distincte 
articulatis; articulis diametro subequalibus, interdum duplo brevioribus (post divisionem), 
ad genicula distincte constrictis; dissepimentis haud granulatis; apiculo obtuso, haud atten- 
uato, interdum recto, interdum curvato ; cytioplasmate granulato. 


Diam.—goo0"' 
Hab.—In stagnis prope Camden, New Jersey. 


Filaments straightish and somewhat rigid, vividly oscillating, bluish-green, interwoven into a 
bluish-green, floating stratum, with moderately long radii, distinctly articulate; articles about 
equal to the diameter, or after division one-half shorter, at the joints distinctly constricted ; 
dissepiments not granulate; apices obtuse, not attenuate, sometimes straight, sometimes 


curved; cytioplasm granulate. 


Remarks.—I have found this species floating on foul ditches near Kaighn’s 
Point, New Jersey, in the month of May. The color of the stratum is a very pure 
deep-green; the single filaments vary from a rather bright deep-green to a pale blue- 
green, according to the power under which they are seen. The apices are not at all 
attenuate. The constriction at the articles is scarcely visible with a lower power than 
ith. The stratum is rather thin, with a good deal of dirt adhering to its bottom. 


20 FRESH-WATER ALGA OF THE UNITED STATES. 


When grown in a bottle, the plant appears as a very thin stratum growing up the 
sides. ‘The agreement of this plant with the descriptions of the-European O. limosa 
is very close, so that I do not think it can be separated from it, although in O. 
limosa the dissepiments are said to be distinctly granular. . 

Fig. 4, pl. 1, represents a filament of the American plant magnified 1250 dia- 
meters. ‘The color and form are closely counterfeited, but the characteristic sepa- 
ration of the endochrome into parts at the joints is decidedly exaggerated. 


O. neglecta, Woon. 

O. trichomatibus modice brevibus, aut dilute purpuraceo-plumbeis aut plumbeo-cinereis, pler- 
umque,rectis, aut stratum mucosum atro-purpureum haud distincte radiante formantibus, aut 
in strato gelatinoso haud radiante subplumbeo dispersis et.cum algis aliis intermixtis, rare 
oscillantibus sed lente sese moventibus; articulis diametro fere 4 plo brevioribus; dissepi- 
mentis plerumque haud granulosis, rare indistincte granulosis; apiculo obtuse rotundato, 
interdum breviter nonnihil attenuato. 


Syn.—O. neglecta, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, 124. 
Diam.— zPyq'' = .0066. 
Hab.—In stagnis prope Philadelphia, 


Filaments rather short, of a dilute purplish-lead color, or leaden-gray, generally straight, either 
forming a mucous, blackish-purple stratum without marked rays, or diffused with other alge 
in a gelatinous mass, rarely oscillating but gliding; articles about four times shorter than 
broad ; joints for the most part not granulate, rarely indistinctly granulate; ends obtusely 
rounded, occasionally short, somewhat attenuate. 


Remarks.—I have found this plant in the shallow ditches along the track of the 
Norristown Railroad above Manayunk, growing in two different ways. In the one 
it forms a distinct, soft, gelatinous, floating stratum of a very dark purplish color, 
consisting of nothing but intérwoven filaments, and provided with long rays. In 
the other, the plant is largely mixed with diatoms and other alge into a thick, 
gelatinous stratum without rays, whose color is a dirty slaty tint, which, however, 
is not all distinctive, and often varies as the proportion of the different constituents 
varies. The color of the single filaments is a slaty, almost neutral tint. The 
.cytioplasm is remarkable for the numerous very minute spots more transparent and 
with less color than the surrounding parts. ‘The ends of the filaments are often 
abruptly obtuse, frequently however there is a very short taper. Motion does not 
appear to be very active, and seems especially to be gliding, rather than a bend- 
ing to and fro of filaments. 

Fig. 5a, pl. 2, is an outline drawing of a filament magnified 450 diameters; 5d 
is a portion of a filament. 


O. imperator, Woop. 

O. in strato mucoso, plerumque natante, olivaceo-atro, longe radiante; trichomatibus rectis aut 
subrectis, tranquillis, dilute viridibus vel saturate olivaceis, haud oscillantibus, sed ambulan- 
tibus; apiculis nonnihil attenuatis, late rotundatis vel subtruncatis, curvatis; articulis diame- 
tro 5-12 plo brevioribus, ad genicula indistincte contractis ; cytioplasmate homogeneo, | 
olivaceo-viride; vaginis firmis, ad genicula distincte transverse striatis. 


Syn.—O. imperator, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, 124. 
Diam.—.002’’. 


FRESH-WATER ALG OF THE UNITED STATES. 21 


Hab.—In stagnis prope Philadelphia. 


O. occurring in an olive-black, mucous stratum, mostly swimming and with long rays; filaments 
straight or straightish, light-green or deep-olive, tranquil, not oscillating, but moving with a 
gliding motion; ends somewhat attenuate, broadly rounded or subtruncate, curved; articles 
5-12 times shorter than broad, slightly contracted at the joints; cytioplasm homogeneous, 
olive-green ; sheaths firm, distinctly transversely grooved at the joints. 


Remarks.—The strata of this species are often of great extent, and resemble 
more masses of spirogyra than of the ordinary oscillatoria. They are very loose in 
texture and are very slimy, whilst their edges are fringed by the long tranquil 
rays. In certain conditions of growth, the endochrome of the filaments is so dense 
as to render them very opaque and the articulations very obscure. ‘The sheaths 
when emptied show the marks of the joints very distinctly ; but, at times, when 
gorged with cytioplasm, scarcely can the sheath itself be seen. ‘The color of the 
filament is also affected by the state of the protoplasm, so that it varies from a 
lightish-green with an olive tint to a very decided dark olive. This species seems 
to be closely allied to the European O. princeps, from which, however, it differs in 
its motion, which is always very slow and merely gliding, its color, the distance of 
the dissepiments, and the much longer curvature of the ends. It grows everywhere 
in the ditches around the city; when mature, generally floating upon the surface 
with an adherent under-stratum of dirt, but, in its earlier history, often adhering 
to the bottom. 2 

Fig. 6a, pl. 1, is a drawing of the end of a filament; fig. 6b, represents a small 
fragment of a filament, showing the tendency to take a roundish or barrel shape; 
much of the endochrome has been squeezed out by the injury which has broken 
the filaments. 


Genus CHTHONOBLASTUS, Kz. 


Phormidii trichomata fasciatim congesta et vagina communi mucosa apice clausa vel aperta inclusa. 
Tales fasciculi numerosi in stratum (quasi thallum) gelatinosum, passim amoso-divisum aggregati. 
Vagine communes achromatice, sepe lamellose, plus minus ampliate, rarius indistincte et subnulle, 
evacuate, pleramque valde intumescentes. Trichomata Phormidii modo oscillantia, articulata et 
vaginata, rigida, recta vel parum curvula, in fasciculos funiformes plus minus dense contorta, apice 
soluta et divaricata. Cellulas propagatorias observare mihi contigit. (R.) 


Filaments fasciately placed together and included in a common mucous sheath with open or shut 
apex. A number of these fasciculi aggregated in a gelatinous stratum (pseudothallus), which is 
gelatinous, and here and there ramosely divaricate. Common sheath colorless, often lamellate, more 
or less enlarged, rarely indistinct and nearly wanting, when empty mostly markedly intumescent. 
Filaments oscillating like to those of Phormidium, articulate and vaginate, rigid, straight, or a little 
curved, more or less densely entangled into cord-like fasciculi, with the apex dissolved and dis- 
severed. 


Ch. repens, Krz. 


Ch. terrestris, strato plus minus expanso, saturate serugineo-chalybeo aut olivaceo-fuscescente, 
mucoso-membranaceo; trichomatibus equalibus in fasciculos filiformes, sepe valde elon- 
gatos, e vaginee communis apertura penicillatim exsertos congestis; articulis diametro equali- 
bus dissepimentis granulatis, apiculo obtuse recto. (R.) 

Species, mihi ignota. 


22 FRESH-WATER ALG#A OF THE UNITED STATES. 


Hab.—Common on damp earth. West Point, New York; Bingham, Massachusetts; Provi- 
dence, Rhode Island; Baily, Silliman’s Journ., N. 8., vol. iii. 

Terrestrial, stratum more or less expanded, deep eruginous chalybeate, or olivaceous fuscous, 
mucous membranaceous ; filaments equal, in filiform fasciculi, which are often much elongate 
and penicillately exserted from the open common sheath ; joints as long as broad, the dissepi- 
ments granulate; the apex obtuse, straight. 


Genus LYNGBYA, AGARDH. 


Trichomata inarticulata vel breve articulata, cellulis perdurantibus instructa. Vagina szpe colo- 
rate, crassa, sepe lamellone. 


Filaments not articulate, or shortly so, furnished with heterocysts. Sheaths often colored, thick, 
often lamellate. 


“HE. muralis, Ac. 
Filaments somewhat rigid, thickish, tortuous, very long, interwoven in a bright, grass-green 
stratum; annuli strongly defined. Ag. Syst., p. 74; Harv. Man. Ed., p. 160; Conf. muralis. 
Ditllw., tab. 1, E, Bot. t. 1554. g. aquatica. 


Hab.—Var. 8. in pools of fresh water, Whalefish Island, Davis Straits. Dr. Lyall. 


The specimens are mixed with turfy soil. Except in the submerged habitat, this agrees with 
the ordinary form. Intermixed with threads of the usual size and structure are others 
cohering in pairs, as in Z. copulata, Harv., which is obviously only a state of this widely 
dispersed species. I have not received specimens of the ordinary Z. muralis from America ; 


but no doubt it is common on damp walls, &c., as in Europe generally.” 
. 


I have never identified this species, and have simply copied Harvey’s account 
of it from the Nereis Boreali Americana, pt. III. p. 104. : 


L. bicolor, Woop. 


L. trichomatibus simplicibus, in ceespites nigro-virides vel ceruleo-virides dense intricatis, varie 
curvatis, plerumque inarticulatis, interdum breviter articulatis et ad genicula contractis; cytio- 
plasmate dilute cieruleo-viride, plerumque copiose granulato, sepe interrupto; cellulis perdu- 
rantibus cylindricis, sepe elongatis, saturate brunneis, sparsissimis; vaginis firmis, achrois, in 
trichomata matura modice crassis. 

Syn.—L. bicolor, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, 124. 

Diam.—yz7pq"". 

Hab.—In flumine Schuylkill prope Philadelphia. 

L. with the filaments closely interwoven into a blackish or bluish-green niat; filaments variously 
curved, simple, mostly inarticulate, sometimes shortly articulate with the joints contracted ; 
endochrome light bluish-green, mostly very granulate, often interrupted ; heterocysts cylin- 


drical, often elongate, deep brown, very few; sheaths firm, transparent, in old filaments 
moderately thick. 


Remarks.—This species is abundant in the shallow water of the Schuylkiil 
River, near Spring Mills, where it forms dark waving tufts ahalf inch or more in 
height, which are adherent either to the bottom of the stream or to some firm sup- 
port, such as large growing plants, sticks fixed in the mud, &c. When examined 
with the microscope, these tufts are seen to be composed of innumerable, very long, 
motionless, greatly curved filaments. They do not seem to be attached to their 
support, but in the denser parts are woven into a very thick mat, which apparently 
adheres en masse to the fixed body. These fitaments are very rarely articulate, 


FRESH-WATER ALGA OF THE UNITED STATES. 23 


but, when they are, the joints are shorter than broad. The endochrome is mostly 
very granulate ; sometimes, however, it is much more homogeneous. The sheaths 
in the old filaments are rather thick, and frequently partially empty; the exterior 
of such sheaths has often a rough, ragged look. The larger cells are very few in 
number. ‘They are elongated cylinders with concave ends. I have found this plant 
in the Schuylkill River, just above Fairmount dam, in a younger state, and appa- 
rently without heterocysts. The threads near their ends had their endochrome 
distinctly articulate, like an oscillatoria, but elsewhere the protoplasm was continu- 
ous. It often contains numerous large granules resembling minute starch grains, 
which however fail to exhibit the reaction with iodine. 

Fig. 7, a, pl. 1, represents a portion of the filament slightly magnified; fig. 7, b, a 
heterocyst from the same specimen more magnified ; fig. 7, c and d, are drawings from 
another specimen from the same locality, each magnified 800 diameters; fig. 8, 
pl. 1, represents the form alluded to in the text as having been found in the 
Schuylkill River just above the dam. 


Famity NOSTOCHACEA. 


Trichomata simplicia, e cellulis distinctis composita, interdum vaginata, articulata, in gelatina 
immersa, cellulis perdurantibus, et interdum sporis porro instructa. 


Filaments simple, composed of distinct cells, sometimes vaginate, imbedded in jelly; furnished 
with heterocysts and sometimes with spores also. 


Remarks.—The nostochaceee are plants of simple construction, consisting of a 
more or less firm jelly in which are imbedded serpentine filaments, composed of 
numerous cells, ‘These cells are mostly more or less globose, especially in the true 
nostocs, so that the filament has amoniliform aspect. ‘They have not distinct walls, 
or at least any that can be distinctly seen by ordinary powers of the microscope, 
and are sometimes closely connected, sometimes rather widely separated. No 
nuclei are usually discernible; I have, however, seen in some instances central 
spots, which were possibly of that nature. The filaments themselves are of various 
length, almost always tortuous, sometimes widely separated, sometimes closely in- 
terwoven. The gelatinous portions of the fronds are of various consistence—some- 
times semifluid, sornetimes very firm, almost cartilaginous. 

The order is divisible into two families—the Nostocs proper and the Spermosiree. 

In the former, the outer portion of the frond is condensed and firm, forming a 
sort of outer coat or epidermis, which is sometimes quite distinct, but in other 
instances can scarcely be said to exist. 

In the filaments of a true nostoc are placed at irregular intervals cells, which 
are mostly larger than the others, and have thick, distinct walls. These cells con- 
tain very little or no chlorophyllous protoplasm. ‘They are often, but by no means 
always, provided with numerous exceedingly attenuated, hair-like processes, or 
quiescent cilia. These bodies were supposed by Kiitzing to have some sexual 
value, and received from him the name of Spermatia. But, as their functions are 
entirely unknown, the name of heterocysts, first applied by M. Allman, is prefera- 
ble. They are the “connecting cells” of Thwaités. No one has as yet demon- 


24 FRESH-WATER ALG OF THE UNITED STATES. 


strated the existence of anything indicating sexuality in the nostocs proper, or 
shown any body at all worthy to be looked upon as a spore. 

Their ordinary method of reproduction is simply a slight modification of that of 
growth. If a fragment of an actively growing nostoc is placed under the micro- 
scope, the filaments of it are seen to be irregular and distorted, thicker in one 
place than another, the cells misshapen, and sometimes apparently lumped and 
fused together. The formation of new filaments is taking place in such cases by 
the simultaneous growth and longitudinal segmentation of the cells of the old, and 
this may occur through the whole or in only a portion of the length of the latter. 
(Pl. 2, fig. 10.) 

The filament of a nostoc is, in other words, capable of a double growth or de- 
velopment, the result in one instance being increase in its length, in the other the 
production of a new form like itself. The first of these is brought about by a 
transverse division of the cells, so that out of each single cell two are formed, 
placed end to end, each daughter-cell at first only half the size of their parent, but 
soon attaining to its full stature. In the other case great increase in the size of 
the cell occurs almost consentaneously with a longitudinal or lateral segmentation, 
the cell dividing in the direction of its length, instead of transversely, so as to form 
two cells lying side by side instead of end toend. ‘The misshapen filaments alluded 
to simply represent different stages of this change, which goes on until two perfect 
filaments lie side by side, to be finally more or less widely separated by the jelly 
which they secrete around themselves. 

This process of growth continues until the plant has arrived at its mature size, 
when it ceases. During this time the inner portion of the- frond has been be- 
coming more and more liquid, and finally the outer epidermis bursts and the 
thoroughly softened inner portion is discharged. In this way, innumerable filaments 
are set free, which are endowed with a power of motion similar to, but much less 
active than, the gliding of the oscillatoria, by means of which they are diffused in 
the water. Scattered in this way, carried hither and thither by currents, each 
minute thread, fixing itself to some object, at last becomes the centre from which 
a new plant is formed in a manner similar to that already described. 

In the second division of the Nostochacee, the jelly is always much less firm 
than in the true nostocs, and is not condensed in the outer portions. The fronds 
are therefore soft, almost diffluent, and entirely shapeless. The filaments them- 
selves also differ from those of the true nostocs. There are no fixed differences 
in the vegetable cells or heterocysts, however, although the former are apt to be- 
come more cylindrical and the filament consequently less moniliform. It is espe- 
cially in the possession of distinct reproductive sporangial cells that the differences 
are to be found. These are much larger than the ordinary cells, from which, in 
their first appearance, they are not distinguishable ; but, when the frond has attained 
a certain age, the spore-cells begin to enlarge both in diameter and length, and 
finally assume a form and size apparently fixed within narrow bounds for each 
species, and surround themselves with distinct, often quite thick coats. It is very 
possible that the production of new individuals may take place by a detachment of 
portions of the frond and subsequent growth, as described in the Nostocs proper, 


FRESH-WATER ALGA OF THE UNITED STATES. 20 


but increase of the species does certainly occur by means of these so-called spores. 
The growth of the plant takes place in the same way as in the true nostocs. 
The filaments increase in length by transverse division and consequent multiplica- 
tion of the cells, whilst new filaments are formed by the consentaneous longitudinal 
division of all the cells of a filament. 

The spores of a Cylindrospermum have the power of germinating after prolonged 
desiccation, they having been successfully cultivated even from specimens long 
preserved in the herbarium. Their development has been carefully and success- 
fully studied by M. Thuret. According to this authority the first change consists 
in an elongation of the spore, which ruptures the wall of the sporangium, pushing 
a portion of it before it. Directly after this the spore undergoes division, so that 
out of it is formed a little torulose filament, composed of four or five cells. Growth 
takes place at both ends, but more rapidly at the free one. The new cells formed 
are smaller than those which arise directly from the spore, but, finally, all the arti- 
cles assimilate. The wall of the sporangium remains attached for a long time to 
the end of the filament forming a little cap to it. The heterocysts, according to 
Thuret, at first are indistinguishable from the ordinary cells, but after awhile the 
granules in them begin to disappear, the color to pale, the outer wall to become 
apparent and grow thicker, until at last a perfect “connecting cell’ is educed. 
I have, myself, carefully watched the early development of the spores of a cylin- 
drospermum, and can confirm, in all essential particulars, the description Thuret 
has given of the process. Fig. 10, pl. 2, represents a partially formed filament, 
to which the empty sporangium is still attached. 

As no sexual reproduction has as yet been shown to exist among the Nostocha- 
cee, it is very evident that their whole life-history is not comprised within the 
changes which have been detailed. It has long been known that the gonidia of 
many lichens have the power of independent existence, %.e. that when they are 
discharged from their thallus they can continue to live and multiply, if circum- 
stances favor them, without giving origin to a new thallus. This, and the great 
similarity of structure between the nostocs and the lichen genus Collema, has 
suggested a possibly close relation between the two. The first observer, I believe, 
who asserted that they were different stages of the same plant was Dr. Hermann 
Itzigsohn. 

His observations are, however, rendered of so little value by his own statements 
that itis not necessary to review them here. Thus, he says, that after seven years’ 
observation he had yet to see a true one called alge, that the Desmidi@ are, at 
least, two-celled, &c. &c. The most weighty observations upon this subject are 
those of Professor Julius Sachs and of J. Baranetzky—the former published in the 
Botanische Zeitung for 1855, the other in the Bulletin of the St. Petersburg 
Academy for 1867. . 

Professor Sachs states that he watched a whole bed of Nostoc commune deve- 
loping into Collema bulbosum. He says that the peculiar Collemoid threads first 
appeared as little lateral offshoots or prolongations from the cells of the nostoc 
filaraent, and rapidly developed into well-formed collemoid filaments. Every 


possible stage from the typical nostoc to the typical collema was seen repeatedly. 
4 February, 1872. 


26 FRESH-WATER ALG OF THE UNITED STATES. 


The development of the distinguishing threads of the collema out of the ordinary 
nostoc-cell has never been confirmed by any other observer; but it seems to me 
that it must be at least provisionally accepted, although De Bary expresses some 
doubt of it. (Morphol. und Physiol. der Pilze, Flechten, &c., p. 290.) 

The researches of M. Baranetzky were directed to the developing of a nostoc 
out of acollema. Hicks and other observers had previously stated that they had 
seen this, but none of them had given sufficient details as to the method of their 
observations, to be fully convincing. 

M. Baranetzky placed sections of actively growing fronds of Collema pulposum, 
Ach, upon smooth, damp earth, using all proper precautions to prevent external 
influence. After some days the sections became less transparent and intensely green 
from the crowding of the gonidia, which were now arranged in curved rows closely 
rolled together into balls. Upon the upper surface of the section appeared little 
gelatinous balls or warts, which contained gonidia in rows, and gradually developed 
typical nostoc forms, whilst on the edges of the sections appeared little colorless 
wart-like masses of jelly, in which, after some time, appeared gonidia, some of 
which developed into the typical nostoc form, others into true collemoid plants. 

Mr. Baranetzky further states that he watched the body of the section gradually 
change by the continual growth and increase of the rows of gonidia, before alluded 
to, and by the disappearauce of the collemoid threads, until at last the whole 
mass of the tissue of the lichen had been converted into a true nostoc, which was 
finally identified as Nostoc vesicarium, D. C.1 

I have no observations of my own to offer upon this subject; but think enough 
has been done to show not only that the nostocs proper have very close relations 
with the collemoid lichens, but that they are probably a peculiar phase in their 
life-history. This being the case, it may seem a perfectly superfluous work to 
indicate species amongst the nostocs. To any one who has given much study to 
the fresh-water alge, the reply to this will immediately suggest itself; namely, that 
in the present state of the science it seems impossible to avoid it; they are so 
commonly thrust at one by collectors, amateurs, &c., are so distinct, are so often 
the subject of tongue and pen, that they must have aname. The idea that at- 
taches to the term species is at present not a very definite one; that there are, 
however, amongst the nostocs fixed forms, which do not change into one another, 
and can readily be distinguished, I have no doubt. Such forms are herein de- 
scribed. If they be only life stages of lichens, I have no doubt that it will finally 
be found that each so-called species of nostoc has its own peculiar so-called species 
of lichen, from which it alone springs, and into which alone it can develop. It 
seems to me, then, that as yet no cause for abandoning the specific names of the 


* In order to aid any one desirous of going over this subject more thoroughly, a list of papers is 
appended :— 

Ventenab und Cassini Opuscula Phytolog., 1817, vol. ii. p. 361. 

Dr. Hermann Itzigsohn. Botanische Zeitung, 1854, p. 521. 

Prof. Julius Sachs. Botanische Zeitung, 1855, p. 1. 

Bayrhoffer. Botanische Zeitung, 1851. 

Hicks. Journal of Microscopical Science, 1861, p. 90. 

Baranetzky. Bulletin de la Société des Sciences Nat., St. Petersburg, vol. xii. p. 418. 


FRESH-WATER ALGZ OF THE UNITED STATES. at 


nostocs has been shown, but only reason to study also their relations with the vari- 
ous collema, 

In regard to the Spermosirew, there is as yet no direct proof whatever connect- 
ing them with lichens. It is very possible that they are not so closely related to 
the true nostocs as is generally believed, so that the probabilities of their being 
. lichens are at present so remote, that for the systematist to refuse to take note of 
their distinct forms, seems to me most unwarrantable. 


Supramity NOSTOCE. 


Thallus peridermate plus minus distincto instructus, sporis destitutus. 


Thallus provided with a more or less distinct integument, and destitute of spores. 


Genus NOSTOC, Vaucuer, (1803.) 

Thallus gelatinosus, varie coloratus, aut globosus vel subglobosus aut foliaceo-membranaceus et 
irregulariter expansus, sepe bullatus. Trichomata plus minus moniliformia. Cellule perdurantes 
exacte spherice vel rare oblonge. 

Thallus gelatinous, variously colored, either globose or subglobose, or foliaceously membranous 
and indefinitely expanded, often a bulla. Filaments more or less moniliforme. Heterocysts exactly 
spherical or rarely oblong. 


a. Thallus globosus vel subglobosus, vel disciformis. 


Thallus globose, subglobose or discoid. 


N. Austinii, Woon, (sp. nov.) 

N. subglobosum, parvum, plernmque magnitudine ovorum piscium, rare ad 2”, fuscescente, 
vel nigrescente, interdum durum interdum submolle, superficie sepe corrugata; tricho- 
matibus varie curvatis, dense intricatis vel distantibus et laxissime intricatis, viridibus, 
fuscescentibus, subplumbeis vel luteo-brunneis, in thallis minoribus spe distincte vaginatis, 
in thallis majoribus haud vel indistincte vaginatis ; articulis maturis globosis, sepe didymis, 
crasse granulatis; cellulis perdurantibus articulorum diametro equalibus vel paulo majoribus, 
globosis, interjectis vel terminalibus, plerumque sparsis. 

Diam.—Cell. Veg., z250"—1z$00" = -0026”—00033"; cell. perdurant, .00033”. 

Hab.—in rupibus irroratis, New Jersey. (Austin.) 

Subglobose, small, mostly the size of fish-eggs, but reaching the diameter of nearly two lines, 
fuscous or blackish, sometimes very hard, sometimes much softer; surface often corrugated ; 
filaments variously curved, densely intricate or distantly and loosely interwoven, greenish, 
fuscous, subplumbeis or yellowish-brown, in the smaller fronds often distinctly vaginate, in 
the larger indistinctly or not all vaginate; mature joints globose, often didymous, coarsely 
granulate; heterocysts equal to the diameter of the other joints or a little larger, globose 
interspersed or terminal. 

Remarks.—The fronds of this distinct species vary greatly in appearance; the 
larger of them are often almost colorless, and, when viewed with the microscope, 
are seen to be composed of a transparent colorless jelly, with remarkably large 
filaments scattered through it. These filaments are generally without sheaths, 
though occasionally a sheath can be faintly traced. The smaller fronds are much 
firmer than the larger and are more decidedly colored. Some of them are entirely 
opaque, looking simply black when viewed by transmitted light under the micro- 
scope. In these the filaments are densely crowded together, often misshapen and 


28 FRESH-WATER ALG& OF THE UNITED STATES. 


provided with distinct broad brownish sheaths: every gradation exists between 
these forms and the first described fronds. The heterocysts are quite uniform in 
size, agreeing in diameter with the largest vegetative cells, they are always single. 
This species is most nearly allied to M. ichthyoon, Rasena.; from which it is 
separated by the differences in the sheaths, the greater size of the filaments, and 
the single heterocysts. It gives me great pleasure to dedicate the species to Mr. 
Austin, by whom it was collected near Gloucester, New Jersey, growing amidst 
mosses on rocks. 


N. pruniforme, (Rors,) Agh. 

N. magnum, gregarium, noncoherens, globosum, magnitudine pisi, pruni majoris et ultra, oliva- 
ceum vel saturate erugineum, etate provecta fusco-nigrescens, haud raro cavum, levissimum, 
intus aquosum, peridermate coriaceo subachroo ; trichomatibus subequalibus, hic illic tumidis, 
laxe intricatis; articulis globosis, plerumque compressis, sepe didymis, arcte connexis; cel- 
lulis perdurantibus articulis duplo majoribus, plerumque terminalibus, rarius interjectis. R. 

. Species mihi ignota. 


Diam.—Artic. 0.00024"—0.0003” ; cell. perdur. 0.0003—0.00045”. (R.) 
Syn.—N. pruniforme, (Rotu,) Ac. Ragznuorst, Flora Europ. Algarum, Sect. II. p. 168. 
Hab.—Maine. Leidy. 


Large, gregarious, not cohering, globose, varying from the size of a pea to a large plum, or 
even beyond this, olivaceous or deep erugineous, in old age blackish fuscous, often hollow, 
very smooth, within watery, periderm coriaceous, somewhat transparent; filaments subequal, 
here and there swollen, laxly intricate; articles globose, mostly compressed, often twofold, 
closely connected; heterocysts twice the size of the vegetative cells, mostly terminal, rarely 
interspersed. 


Remarks.—1 have never found this species; but some years since some speci- 
mens, sent to the Academy of Natural Sciences of Philadelphia from Maine, were 
identified by Professor Joseph Leidy as belonging to it. 


N. verrucosum, (Liny.) Vaucu. 

N. magnum, gregarium, bipollicare et ultra, subglobosum, sepe lobatum, verruculosum, irrora- 
tum, initio solidum, postremo cavum, vesiciforme, saturate brunneo-viride; peridermate mem- 
branaceo-coriaceo, olivaceo-fuscescente; trichomatibus varie curvatis, centralibus parcioribus 
et laxissime intricatis, periphericis densius intricatis; articulis oblongis, rare globosis, arcte 
connexis, crasse granulatis; cellulis perdurantibus interstitialibus vel terminalibus, sphericis, 
articulorum diametro duplo majoribus. 


Diam.—Cell. vegetativ. .000166”; cell. perdurant. .000233”. 

Syn.—N. verrucosum, (LINN.) Vavon. Rasennorst, Flora Europ. Algarum, Sect, IT. p. 176. 

Hab.—In fonte, Centre County, Pennsylvania. 

Large, subglobose, often lobed, warty ; gregarious, two inches in diameter, growing under water, 
fixed, in the beginning solid, afterwards hollow, bladder-shaped; periderm membranaceous, 
coriaceous, olivaceous-fuscous; filaments variously curved, centrally fewer, and laxly intricate, 
towards the outside much more close; articles oblong, rarely globose, closely connected, 


coarsely granulate; heterocysts interstitial or terminal, spherical, twice the size of the other 
joints. 


Remarks.—In the summer of 1869, I found a nostoc growing in great abundance 
in a very cold, large, limestone spring in Centre County, Pennsylvania, which I 


FRESH-WATER ALGA OF THE UNITED STATES 29 


have referred to N. verrucosum with some little hesitation. Some of the fronds 
were smoothish, others very decidedly warty. My specimens are old plants, 
which have become hollow by the discharge of their internal contents. It is pos- 
sibly on this account I have not been able to verify the minute description given 
by Professor Rabenhorst. As the latter may not be accessible to some of those 
who consult these pages, I append the latter part of it, which differs from that 
given by myself from the American plants. 

“ Trichomatibus flexuoso-curvatis, quasi triplici ordine; centralibus parcioribus, 
laxissime implicatis, apices versus plus minus attenuatis, articulis oblongis, sub- 
distantibus, periphericis densius sepe densissime intricatis, basi haud raro cellulis 
biseriatis, articulis globosis, arcte connexis, extremis (nonnisi in thallo vetusto 
occurrunt) subflagelliformibus, articulis oblongis, cylindraceis sphericisque simul 
immixtis, distantibus; cellulis perdurantibus sphericis interjectis terminalibusque, 
nonnunquam pluribus simul seriatis articulorum diametro duplo triplove majoribus,” 

According to Professor Harvey (Nereis Bor. Amer., part iii. p. 114), this species 
has been collected by Dr. Lyall in pools of fresh water, Isle of Disco, and at 
Beechey Island, Arctic Regions; also by Mr. Fendler at Sante Fé, New Mexico. 


N. alpinum, Krz. 

N. rupestre, immersum; thallo suborbiculare, erecto, membranaceo, ad {=2 unciam lato, ad 
lineas duas vel tres crasso, tenaci, saturate olivaceo-fusco, levi, sepe rugoso-plicato, cum mar- 
gine integro et plerumque incrassato; trichomatibus varie curvatis, laxe vel nonnihil dense 
implicatis; articulis fuscis vel dilute erugineis plerumque globosis, sepe subtiliter granulatis, 
arcte connexis; cellulis perdurantibus sphericis plerumque articulorum diametro paulo ma- 
joribus, interdum subequalibus, interjectis vel terminalibus. 


Diam.—Artic. vegetativ. .00016’’—00023”’; cell. perd. .00026. 


Syn.— N. alpinum, Krz. Phycol. General., p. 206, No. 10.” Ragpennorst, Flora Europ. 
Algarum, vol. ii. p, 174. 
“WN. Sutherlandi, Dickie.” Harvey, Nereis Boreali Americana, part iii. p. 114. 
“ N. cristatum, BatLey.” Harvey, Nereis Boreali Americana, part iii., 1857, p. 114. 
Growing attached by its margin to the rocks in running water; thallus suborbicular, erect, 
membranaceous }—2 an inch high and 1—38 lines thick, very tenacious, deep olive-green, 
smooth, often rugosely plicate especially at the base, with the margin entire, rounded, and 
mostly thickened; filaments variously curved, laxly or somewhat densely interwoven; arti- 
cles fuscous or greenish, mostly globose, often finely granulate, closely connected ; heterocysts 
spherical, generally a little larger than the ordinary cells, sometimes about equal to them, 
interspersed and terminal. 


Remarks.—This interesting little plant was found in the mountain rivulets 
near West Point, New York, by the late Prof. Bailey, and received from him the 
specific name cristatwm, first published in Harvey’s work on the North American 
Alge. I have myself seen it growing in very great abundance in rapid mountain 
streams in the central portions of this State. It is doubtless, therefore, an inhabi- 
tant of the whole Alleghany range. In the low country, east or west of these 
mountains and their outlying hills, I do not know of its having been found. I have 
very recently received specimens of a nostoc from Sereno Watson, Esq., undoubt- 
edly belonging to this species, which were collected by himself, in cold streams in the 
Clover Mountains, Nevada, at an altitude of 11,000 feet. Under the name of M. 


30 FRESH-WATER ALG& OF THE UNITED STATES. 


Sutherlandii a nostoc has been described by Mr. Dickie, which was collected.in the 
neighborhood of Baffin’s Bay, and must be referred to this species, although the 
description given of it is very imperfect.” Again, NV. alpinum, Krz., appears to be in 
all respects similar to the North American forms. So that this cosmopolitan little 
plant seems only to ask for a cold shelter, and it flourishes. The Alps, the Alle- 
ghanies, the Rocky Mountains, and the cold North are its homes. To those who 
believe in a single centre for a species, the suggestion that it has spread across 
the globe, through the arctic regions, and followed our mountain chains southward, 
will of course present itself. 

As I have seen it, the plant is very abundant where it grows, five, six, twelve, 
or more of the little fronds adhering to a single pebble. ‘The frond is generally 
longer than broad, the margin sometimes sinuous but never, as I have seen it, 
lobate or incised. It appears finally to burst and discharge its inner portion, 
whilst the outer cortical portion, now a little vesicle containing a globule of air, is 
set free and floats down the stream. 


N. depressum, W000, (sp. nov.) 
N. enormiter suborbiculare, minutum, gregarium et interdum aggregatum muscos immiersos 


adherens, mangitudine seminis sinapeos vel parvius, durum, elasticum, subnigris; peridermate 
firme, achroo; trichomatibus plerumque laxe intricatis, haud vaginatis ; articulis globosis, 
plerumque modice arcte connexis, rare distantibus; cellulis perdurantibus globosis, ceteris 
paulo majoribus. 


" Diam.—Artic. veget. max: .0002/; cell. perdurant. max .00029. 
Hab.—In rivulis, New Jersey (Prof. Austin). 


Irregularly suborbicular, gregarious and sometimes aggregated, elastic, blackish, about the size 
of a mustard-seed, or smaller, adhering to immersed mosses ; periderm firm, translucent; fila- 
ments not vaginate, mostly loosely interwoven; joints globose, generally rather closely con- 
nected, rarely distant; heterocysts rather larger than the other. 


Remarks.—This plant was found by Prof. Austin attached to a brook-moss 
(Dichelyma), growing in a rapid rivulet in Northern New Jersey. 

The minute fronds sometimes are so thin and spread out as to be almost folia- 
ceous. ‘The species I take to be most nearly allied to N. lichenoides of Europe, 
from which it is, however, apparently distinct. In the American plant the fila- 
ments and heterocysts are a little larger, and the frequent elliptical cells of the 
European plant are wanting. The frond also apparently does not grow so large as 
the European, and is further distinguished by its flat, discoid form. In many of the 
specimens examined the filaments are very thick, irregular, and contorted, the cells 
being fused together. In other instances, a filament will be plainly double, and 
every grade between these conditions is present. This is plainly owing to a process 
of growth, to the cells enlarging and dividing laterally so as to form new filaments. 


N. sphzericum, (Porrer,) Vaucu. 

N. globosum, interdum oblongum vel ovale, gregarium, sepius aggregatum, raro tamen conflu- 
ente, durum, elasticum (in etate provecta intus molle et subaquosum?), olivaceum, magnitudine 
seminis sinapeos, ad cerasi parvi; peridermate firmo, pellucido; trichomatibus intricatis, luteo- 
lis, aut prasinatis aut dilute ceruleis; articulis pleramque subquadratis, interdum transverse 


FRESH-WATER ALG OF THE UNITED STATES. 31 


subovalibus, arcte connexis; cytioplasmate granulato; cellulis perdurantibus interjectis 
terminalibusque, sphericis. 


Diam.—Artic. diam. long. ggg” = .000125";  transv. gy'55” = .00017”; cell. perdurant. 
sz00 = .00029”. 

Syn.—wWN. sphericum (Porret ) Vaucn. Ragenuorst, Flora Europ. Algarum, Sect. II. p. 167. 

Hab.—In fontibus, prope Philadelphia. 

Globose, sometimes oblong or oval, gregarious, but rarely confluent, hard, elastic (in advanced 
age within soft and watery’), olivaceous, varying from the size of a mustard-seed to that of 
asmall cherry; periderm firm, pellucid; filaments intricate, yellowish, greenish or bluish; 


articles mostly subquadrate, sometimes transversely suboval, closely connected; cytioplasm 
granular; heterocysts interspersed or terminal, spherical. 


Remarks.—The specimens from which the above diagnosis was prepared were 
found at Spring Mills, adhering to mosses and twigs in the water. The fronds 
were remarkable for their firmness and elasticity. The color was a dull, rather 
greenish, olive; that of the filaments varied from a decided greenish to a marked 
yellowish, or sometimes an almost silvery bluish tint. The heterocysts were rather 
few in number, and were either terminal or interstitial, sometimes they were with- 
out, sometimes with evident endochrome. The length of the general articulations 
varied a good deal, it was, however, mostly less than their breadth, which seems 
quite constant. When kept in water in the house, this species softens, and the 
periderm as it were peels off, allowing the interior to disperse itself as it gradu- 
ally becomes more and more diffluent. Most of the fronds afforded ample evidence 
of their method of’ growth by the presence of filaments in every stage of division. 

Fig. 10, pl. 2, represents filaments of this species. 


N. czeruleum, Lynes. 

N. minimum, sepe microscopicum, enormiter globosum vel subglobosum, affixum, gregarium, 
sejunctum vel aggregatum ; trichomatibus valde inequalibus; articulis elongato-cylindraceis, 
vel acute ellipticis, vel perfecte ellipticis, vel globosis, vel subglobosis, vel subquadrangulis, 
sejunctis et nonnihil distantibus vel arcte connectis aut confluentibus; cellulis perdurantibus 
globosis, passim interjectis terminalibusque, ceteris duplo vel subduplo majoribus. 

Diam.—Cell. perdurant, .000303; cell. vegetat. plerumque .00012—000166’’; rarius .0001— 
.00021. 


Syn.—N. ceruleum, Lynas. Rasenuorst, Flora Europ. Algarum, Sect. II. p. 167. 


Hab.—Inter muscos, New Jersey (Prof. Austin). 


Very small, often microscopic, irregularly globose or subglobose, affixed, gregarious, separate or 
aggregated ; filaments very unequal; articles elongate-cylindrical, or acutely elliptical or 
perfectly so, or subglobose, or globose, or subquadrangular, separate and somewhat distant 
or closely connected or confluent; heterocysts globose, interspersed or terminal, double or 


about double the size of the other cells. 


Remarks.—I am indebted to Mr. Austin for specimens of this species collected by 
him in Northern New Jersey. The fronds grow attached to moss and are very mi- 
nute, the largest I have seen being not more than half a line in diameter. The 
filaments are remarkable for their inequality, which is often very perceptible in 
different parts of the same filament. Ihave referred my specimens to N. cerulewm— 


32 FRESH-WATER ALGH#H OF THE UNITED STATES. 


the only differences between them and the European plant are that they are not so 
large, and do not agree in color, many of them being browner; but these are certainly 
insufficient grounds for separating them. Prof. Rabenhorst speaks of observing 
the contents of heterocysts dividing up so as to form a little colony of cells, which 
finally break through the maternal wall. I have only studied mounted specimens, 
but have seen very clearly heterocysts in which this process was taking place. 


N. punctatum, Woop, (sp. nov.) 
N. terrestre; thallo expanso orbiculare vel nonnihil irregulare, tenuissimo, eruginev, parvo 


membranaceo, pellucidulo; trichomatibus laxe intricatis, varie curvatis, articulis globosis vel 
sepius ellipticis, plerumque medio pellucidulis, laxe connexis; cellulis perdurantibus termi- 


nalibus vel interjectis. 
Diam.—Cell. vegetat. ys255” = -000166; cell. perdur. ysgoq” = .00033. 


Hab.—In terrestre, New Jersey, (Prof. Austin.) 


Terrestrial; thallus expanded, irregular or orbicular, very thin, eruginous, small, membranous, 
pellucid; filaments loosely interwoven, variously curved, joints globose or often elliptical, 
mostly pellucid in the centre, loosely connected ; heterocysts terminal or interspersed. 


Remarks.—Mt. Austin has kindly sent me the only specimens I have seen of this 
species; they are labelled “Damp Ground, Sept.” The fronds, which are often 
aggregated, are very small and exceedingly thin, especially in their central por- 
tions, where they are quite translucent; in form they are often circular, some- 
times quadrangular, sometimes quite irregular. As to size, most of them are not 
more than two lines in diameter, some three, or possibly five lines. The margins 
are often reflexed and thickened, especially in the smallest fronds. Two kinds 
of filaments are visible; Ist, those which I take to be in a perfected quiescent 
state; 2d, those which are in active growth. The former are composed of globose, 
or more commonly elliptical joints, which are remarkable for the possession of a 
central translucent, almost colorless spot, the endochrome apparently being arranged 
in a ring around the outer part of the cell. This is, however, occasionally want- 
ing. The filaments, which are in active growth, are very irregular in form, often 
much broader than the others; their cells very irregular and sometimes fused 
together into one mass. The measurements given in the diagnosis were taken 
from the filaments of the first kind. 

b. Thallus indefinite expansus. 
Thallus indefinitely expanded. 
N. Cesatii, Bats. 
N. terrestre; thallo longe lateque expanso, gelatinoso-membranaceo, viridi-flavescente ; tricho- 


matibus flexuoso-curvatis, sublaxe implicatis, pallide erugineis; articulis sphericis, laxe vel 
arctius connexis; cellulis perdurantibus spheericis, et interjectis et terminalibus. 


Diam.—Artic. .00016—.0002; cell. perdur.—.00038”. 
Syn.—WN. Cesatii, Bats. Rapennorst, Flora Europ. Sect. II. p. 175. 
Hab.—In terrestre, Kansas (Prof. Parry); Texas (Prof. Ravenel). 


Terrestrial; thallus broadly and indefinitely expanded, gelatinous-membranaceous, yellowish- 
green; filaments flexuously curved, rather laxly implicate, pale-greenish; articles spherical, 
laxly or more closely connected ; heterocysts spherical, both interstitial and terminalibus. 


FRESH-WATER ALGA OF THE UNITED STATES. 33 


Remarks.—This plant was sent to me by Dr. C. C. Parry, from whose letter the 
following is extracted: “I send enclosed specimens of a singular land Alga? which 
I met with in this vicinity; lightly attached to bare patches of soil interspersed 
with buffalo grass. In the adjoining bluffs are cretaceous shales full of seams and 
layers of selenite, from the decomposition of which the bottom soil becomes 
strongly impregnated with various saline matters. ‘The present season has been 
characterized by unusual quantities of rain, causing extensive floods over what is 
usually a dry, arid district.” 

The agreement between the mature forms is essentially perfect. There can be 
scarcely any doubt as to the identification, although I have not seen the Ameri- 
can plant in its young state. The fronds appeared to be 1—2 lines in thickness, 
with its surface smooth, or sometimes with close subparallel ridges or wrinkles. 


According to Rabenhorst, the young European WM. cesatii is in the beginning 
globose, and pale golden-yellow ; soon, however, bursting and spreading out into an 
indefinitely expanded thallus. 


Among the alge collected by Prof. Ravenel in Texas is a Nostoc, labelled “On 
Mud Flats, Cedar Bayou, Harris Co.,” which comes so close to N. cesatii, that I 
think it must be referred to it. It differs only in being more olivaceous, some- . 
what firmer and in the size of the heterocysts—the largest of the latter which I 
have examined, attaining the size only of .00027”. The largest vegetative cells are 
.00017 in diameter. 


N. calcicola? Aa. 

N. thallo irregulariter expanso, enormiter sublobato, tenue, membranaceo, cartilagineo, elastico, 
pellucido, aut laete viride, vel brunneo, vel dilute viride, irregulariter undulato plicato vel 
bullatoo; peridermate plerumque subnullo; trichomatibus cum filis leptothrichoideis ramosis 
intermixtis, flexuosis, plerumque distantibus, rarissime e cellulis biseriatis compositis ; cellulis 
subglobosis, oblongis, ovalibus, cum ceteris ellipticis intermixtis, plerumque laxe connexis; 
cellulis perdurantibus spnericis, interjectis et terminalibus. 

Diam.—Art. gtgq"—1 7300" = -0001"4—.0001"; cell. perdur. yo3qq’—saya” = .0003’— 
0002”. : 


Syn.—wN. calcicola, Ac. Rapenuorst, Flora Europ., Sect. II. p. 174. 
Hab.—In rupibus, Georgia. (Prof. Ravenel.) 


Thallus irregularly expanded, membranaceous, thin, cartilaginous, elastic, pellucid, bright green, 
pale green or brownish, thin, irregularly undulately plicate or bullate; periderm mostly 
scarcely distinguishable; filaments intermixed with branched leptothrix filaments, -flexuous, 
mostly distant, very rarely composed of biseriate cells; cells subglobose, oblong, oval, inter- 
mingled with elliptical ones, mostly loosely connected ; heterocysts spherical, interspersed or 


terminal. 


Remarks.—This species is one of those sent me by Dr. Billings. It was collected 
near Catoosa Springs, Georgia, by Prof. H. W. Ravenel. In the dried state it is 
of a dirty olive-green, and very much wrinkled and irregular on its surface. The 
largest specimens are about an inch long. There is no very distinct periderm, 
although in some places the filaments are placed more closely together on the outer 


portions of the frond. This plant seems to agree with the descriptions of the 
5 March, 1872. 


34 FRESH-WATER ALG OF THE UNITED STATES. 


European 8. calcicola, from which it differs somewhat, however, in having its hete- 
rocysts both terminal and among the cells, and also somewhat in their size. 


N. calidarium, Woop. 

N. thallo maximo, indefinite expanso, aut membranaceo-coriaceo vel membranaceo-gelatinoso 
vel membranaceo, aut lete virdi vel sordide olivaceo-viridi vel olivaceo-brunneo, irregulariter 
profunde laciniato-sinuato, ultimo eleganter laciniato; trichomatibus inequalibus, interdum 
flexuoso-curvatis, plerumque subrectis et arcte conjunctis, in formis duabus occurrentibus : 
forma altera parva, viridi, articulis cylindricis, cum cellulis perdurantibus hic illic interjectis, 
vaginis interdum obsoletis, sepius diffluentibus; forma altera maxima, articulis globosis vel 
oblongis, aurantiaco-brunnea, cellulis perdurantibus ab articulis ceteris haud diversis. 


Diam.—Forme prime articuli maximi zy3gq unc.; cellule perdurantis gygq unc. Forme 
secunde articuli long. sg55 to spyq Une., lat. gdog to selon, articuli globosi 355 to gy'gg UDC. 

Syn.—WN. calidarium, Woop, American Journal of Science and Arts, 1869. 

Hab.— Benton Springs, Owen’s Valley, California” (Mrs. Partz). 


Thallus very large, indefinitely expanded, either membrano-coriaceous or membrano-gelatinous 
or membranaceous, either bright green or dirty olive-green or olive-brown, irregularly pro- 
foundly laciniately sinuate, finally elegantly laciniate; filaments unequal, sometimes flexu- 
ously curved, but mostly straightish and closely conjoined, occurring in two forms; the 
one small, green, with cylindrical joints, the heterocysts scattered here and there, the sheaths 
sometimes absent, often diffluent; the other form very large, with globose or oblong articles, 
orange-brown, the heterocysts not different from the other cells. 


Remarks.—Numerous specimens of this species were received from Mrs. Partz, 
who collected them in Benton’s Spring, a thermal water situated in the extreme 
northern point of Owen’s Valley, California, sixty miles southwest from the town 
of Aurora. The following extract from a letter of Mrs. Partz describes the place 
and mode of their growth more minutely. 


“‘T send you a few samples of the singular vegetation developed in the hot springs 
of our valley. These springs rise from the earth in an area of about eighty square 
feet, which forms a basin or pond that pours its hot waters into a narrow creek. 
In the basin are produced the first forms, partly at a temperature of 124°—135° 
Fahr. Gradually in the creek and to a distance of 100 yards from the springs are 
developed, at a temperature of 110°—120° Fahr., the Alge, some growing to a 
length of over two feet, and looking like bunches of waving hair of the most beau- 
tiful green. Below 100° Fahr., these plants cease to grow, and give way to a slimy 
fungus growth, though likewise of a beautiful green, which, finally, as the tempera- 
ture of the water decreases, also disappears. They are very difficult to preserve, 
being of so soft and pulpy a nature as not to bear the least handling, and must 
be carried in their native hot water to the house, very few at a time, and floated 
upon paper. After being taken from the water and allowed to cool they become 
a black pulpy mass. But more strange than the vegetable are the animal organ- 
izations, whose germs, probably through modifications of successive generations, 
have finally become indigenous to these strange precincts. Mr. Partz and myself 
saw in the clear water of the basin a very sprightly spider-like creature running 
nimbly over the ground, where the water was 124° Fahr., and on another occasion 
dipped out two tiny red worms.” 


FRESH-WATER ALG OF THE UNITED STATES. 30 


In regard to the temperatures given, and the observation as to the presence of 
animal life in the thermal waters, Mr. William Gabb, of the State Geological 
Survey, states ‘that he has visited the locality, knows Mrs. Partz very well, and that 
whatever she says may be relied on as accurate. 


The color of the dried specimen varies from a very elegant bluish-green to dirty- 
greenish and fuscous-brown. After somewhat prolonged soaking in hot water, the 
specimens regained apparently their original form and dimensions, and were found 
to be in very good condition for microscopical study. 


The plant in its earliest stages appears to consist simply of cylindrical filaments, 
which are so small that they are resolved with some difficulty into the component 
cells by a first-class one-fifth objective. Fronds composed entirely of filaments of 
this description were received. Some of these were marked as “first forms,” and 
as having grown in water at a temperature of 160° Fahr. Probably these were 
collected immediately over the spot where the heated water bubbled up. At this 
temperature, if the collection made is to be relied on as the means of judging, the 
plant does not perfect itself. ‘To the naked eye these “first forms” were simply 
membranous expansions, of a vivid green color and indefinite size and shape, 
scarcely as thick as writing-paper, with their edges very deeply cut and running 
out into a long, waving, hair-like fringe. Other specimens, which grew at a much 
lower temperature, exactly simulated those just described, both in general appear- 
ance and microscopical characters. ‘These, I believe, were the immature plant. 


The matured fronds, as obtained by the method of soaking above described, were 
“gelatinous membranous,” of a dirty-greenish or fuscous-brown at their bases, and 
bright green at their marginal portions, where they were deeply incised and finally 
split up into innumerable hair-like processes. Proximally they were one, or even 
two, lines in thickness, distally they were scarcely as thick as tissue paper. ‘Their 
bases were especially gelatinous, sometimes somewhat translucent, and under the 
microscope were found to have in them only a few distant filaments. 

Two sets of filaments were very readily distinguished in the adult plant. The 
most abundant of these, and that especially found in. the distal portions of the 
fronds, were composed of uniform cylindrical cells, often enclosed in a gelatinous 
sheath. The diameter of such filaments varies greatly; in the larger the sheaths 
are generally apparent, in the smaller they are frequently indistinguishable. 

In certain places these filaments are more or less parallel side by side, and are 
glued together in a sort of membrane. It is only in these cylindrical filaments 
that I have been able to detect heterocysts, which are not very different from the 
other cells; they are about one-third or one-half broader, and are not vesicular, but 
have contents similar to those of the other cells. In one instance only was I able 
to detect hairs upon these heterocysts. 

The larger filaments are found especially near the base and in the other older 
portions of the frond. Their cells are generally irregularly elliptical or globose, 
rarely are they cylindrical. They are mostly of an orange-brown color; and there 
exists a particular gelatinous coating to each cell rather than a common gelatinous 


36 FRESH-WATER ALG OF THE UNITED STATES. 


sheath to the filament. These larger threads are apparently produced from the 
smaller filaments by a process of growth. 

Near the base and in the under portions of the fronds, these filaments are scat- 
tered in the homogeneous jelly in which they run infinitely diverse courses. In 
the upper portions of the frond, and at some little distance from the base, the ad- 
joining cells are very close to one another, and pursue more or less parallel courses, 
with enough firm jelly between to unite them into a sort of membrane. 

This plant certainly belongs to the Nostochacee, and seems a sort of connecting 
link between the genera Hormosiphon of Kiitzing and Nostoc. 

The best algologists now refuse to recognize the former group as generically 
distinct; and the characters presented by this plant seem to corroborate that view. 

Adherent to, and often more or less imbedded in, the fronds of the Nostoc, were 
scattered frustules of several species of diatoms, none of which was I able to iden- 
tify. In some of the fronds there were numerous unicellular Alge, all of them 
representatives of a single species belonging to the genus Chroococcus, N ageli. 
This genus contains the very lowest known organisms—simple cells without nuclei, 
multiplying, as far as known, only by cell-division. These cells ure found single or 
associated in small families; and in certain species these families are united to form 
a sort of indeterminate gelatinous stratum. In these species the families are com- 
posed of but very few cells, surrounded by a very large, more or less globular or 
elliptical mass of transparent, firm jelly. The species is very closely allied to 
Chroococcus turgidus, var. thermalis, Rabenh., from which it differs in the outer 
jelly not being lamellated. 

The technical description of this plant will be found in the proper place. 

Fig. 2a, pl. 2, represents the most mature and largest filament; Fig. 26, a small 
filament from the same frond, each magnified 800 diameters. Fig. 2 ¢, represents 
portions of the upper surfaces of fronds. 


N. comminutum, K7z. 

N. thallo indefinite expanso, gelatinoso, natante, modo viride, plerumque sordide ferrugineo; 
trichomatibus flexuosis, plerumque subdense intricatis; articulis globosis (ante divisionem 
factam subcylindricis), subtiliter granulatis, interdum lete viridibus, plerumque ferrugineis 
aut luteo-fuscescentibus aut fuscis; cellulis perdurantibus globosis, articulorum diametro 
duplo majoribus, interjectis aut terminalibus. 

Diam.—Artic. ggyy”; cell. perdur. sg55”. 

Syn —N. comminutum, Krz. Raxenuorst, Flora Europ. Algarum, Sect. IT. p. 179. 


Hab.—In fossis natante, prope Philadelphia. 
Thallus indefinitely expanded, gelatinous, floating, mostly sordidly ferruginous, sometimes 
greenish; trichomata flexuous, mostly subdensely intricate; joints globose (before division 


subcylindrical), minutely granulate, sometimes bright green, sometimes ferruginous, yellow- 


ish-fuscous, or fuscous; heterocysts globose, about twice as long as ordinary joints, both 
interspersed and terminal. 


Remarks.—This species is to be found floating on the surface of the ditches 
below the city in the latter part of August and September, forming a repulsive, 
ferruginous, slimy scum. The periderm is not very apparent, and indeed the sepa- 


FRESH-WATER ALGA OF THE UNITED STATES. 37 


rate fronds are not distinct. The filaments are very long, mostly closely intricate, 
very much curved; in some places they are more sparse. Their color is mostly a 
sort of yellowish ferruginous-green, sometimes they are, decidedly, almost purely 
ferruginous, more rarely a bright green. This plant agrees pretty well with the 
descriptions of the European Nostoc comminutwm, and I believe is the same 
species; if, however, N. lacustre of Kiitzing is distinct from N. comminutum, this 
is also; but I incline to the opinion that they are all different forms of one plant. 
Fig. 3, pl. 2, represents a single filament magnified 800 diameters. 


N. commune, Vavcu. 


N. terrestre, thallo irregulariter expanso, difformi, undulato-plicato, tremulo, intus aquose gela- 
tinoso, etate provecta plerumque excavato, peridermate subcoriaceo firmo, olivaceo, Inteo- 
fuscescente vel luteo-fusco cincto; trichomatibus flexuoso-curvatis, pallide srugineis, laxe 
implicatis, equalibus vel subequalibus, haud raro a basi ad medium usque cellulis biseriatis 
compositis; articulis sphericis vel e mutua pressione subquadrangularibus, laxe connexis, 
passim distantibus, puncte centrali turbato praditis; cellulis perdurantibus globosis, articu- 
lorum diametro duplo majoribus, interstialibus terminalibusque. 


Diam.—Cell. vegetat. .00012”—.00016”; cell. perdurant. .00025”—.00033”. 
Syn.—N. commune, Vavon. Rasennorst, Flora Europ. Algarum, Sect. II. p. 175. 
Hab.—In terrestre, New Jersey. (Austin.) ‘Rio Bravo. Schott.” Harvey. 


Terrestrial ; thallus irregularly expanded, shapeless, undulate-plicate, tremulous, within of the 
consistence of thin jelly, in advanced age mostly hollow ; periderm subcoriaceous, firm, oliva- 
ceous, yellowish-fuscous ; filaments flexuously curved, pale green, laxly implicate, equal or 
subequal, not rarely composed of a double series of cells from their base to their middle; 
articles spherical or subquadrangular from mutual pressure, loosely connected, here and there 
distant, furnished with a central spot; heterocysts globose, twice as large as the vegetative 
articles, interstitial and terminal. 


Remarks.—The only specimens I have seen of this species are very old ones, 
which have burst and discharged their central portions. I have consequently pre- 
ferred to copy the diagnosis of Prof. Rabenhorst. My specimens agree pretty 
closely with it. The filaments, and also the single cells, are closer together than 
his words would seem to indicate. My measurements of the heterocysts, as given 
above, are larger than those of Prof. Rabenhorst. ‘They agree, however, with his 
text, which his own measurements do not. I am indebted to Prof. Austin for 
specimens of this species, which he collected in Northern New Jersey. According 
to Professor Harvey this plant was collected by Dr. Schott along the Rio Bravo, 
where it is common on dry flats after rains. 


SuBFAMILY SPERMOSIRE. 


Thallus sine peridermate, interdum nullus. Trichomata sporis instructa. 


Thallus without any periderm, sometimes absent. Filaments furnished with spores. 


Genus ANAB/ENA, Bory. 


Trichomata moniliformia, evaginata; sporis sphericis, aureis vel aureo-fuscis, plerumque singulis, 
cum cellulis vegetativis vel perdurantibus conjunctis. 


38 FRESH-WATER ALG#Z OF THE UNITED STATES. 


Filaments moniliform, without sheaths; spores spherical, yellow or yellowish-fuscous, mostly sin~ 
gle, variously placed as to the heterocysts and ordinary cells. 


Remarks.—'Che characters which I have given are somewhat different and less 
exacting than those of Prof. Rabenhorst, otherwise our American species would 
hardly be covered by the diagnosis. Professor Harvey in his Phycologia Britan- 
nica states that A. Jussieu had preoccupied the name, Anabaena, by applying it to 
a genus of Huphorbiacee. The date of Bory’s name is, however, 1823, whilst that 
of Jussieu is 1824. Hence, it is the latter which must be changed. 


A. gelatinosa, Woop. 


A. thallo mucoso gelatinoso, indefinite expanso, dilutissime brunneo, nonnihil pellucido ; tricho- 
matibus haud vaginatis, leviter flexuoso-curvatis, nonnihil distantibus, haud intricatis, aut 
dilute aureis aut dilute ceruleo-viridibus; articulis globosis, homogeneis; cellulis perdu- 
rantibus articulorum diametro fere equalibus, globosis, vel rare oblongis; sporis terminalibus, 
singulis, globosis (fusco-brunneis ?). 


Syn.—A. gelatinosa, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, 126. 

Hab.—Prope Philadelphia. 

Thallus gelatinous, mucous, indefinitely expanded, somewhat. pellucid, with-a brownish tinge ; 
filaments not vaginate, somewhat curved, rather distant, not intricate, either a light golden- 


yellow or light bluish-green; joints globose, homogeneous; heterocysts about equal to the 
filaments in diameter, globose or rarely oblong; spores terminal, globose. 


Remarks.—The color of the shapeless mass of jelly of which the frond is com- 
posed is a light.brown with, in places, a decided reddish or flesh-colored tint. The 
heterocysts are either interstitial or terminal, no hairs were detected on them; 
they are mostly globose and only occasionally are they oblong. 

Fig. 4, pl. 2, represents a filament of this species magnified 750 diameters; the 
color of the endochrome of the large spore was possibly due to its being dead. 


A. flos aquze, (Lynes.) Krz. 


A libere natans, submembranacea, eruginea; trichomatibus plus minus curvatis, sepius circi- 
natis; articulis sphericis vel e mutua pressione modo ellipticis modo oblongo-quadratis; cel- 
lulis perdurantibus ellipticis singulis vel geminis; cytioplasmate pallide erugineo granulato 
turbato ; sporis exacte globosis aureo-fulvis lucidis, sinzulis interjectis, articulorum diametro 
subduplo majoribus. R. Species mihi ignota, 


Diam.—Artic. 0.00017”—0,00025"; diam. long cell. perd. 0.00048”—0.00053"; — spor. 
0.00032"—0.0004”. 


Syn.—A. flos aque, (Lynes.) Krz. Rasennorst, Flora Europ. Algarum, Sect. IT. p. 182. 


Hab.— Round Pond, West Point, New York.” Prof. Bailey. Silliman’s Journal, N. 8., vol. 
ili. 18 

Swimming free, submembranaceous, eruginous; filaments more or less curved, ‘very often cir- 
cinnate; articles spherical, or, from mutual pressure, elliptical or oblong quadrate ; heterocysts 


elliptical, single or geminate ; cytioplasm pale eruginous, granulate ; spores exactly globular, 
golden-fulvous, bright, singly interspersed, nearly twice the diameter of the joints. 


A. gigantea, Woop. 


A. thallo nullo, trichomatibus singulis et numeroso-consociatis, natantibus, rectis, in state 
juveni spiraliter convolutis; articulis plerumque subglobosis, arcte connexis, granulosis; cel- 


FRESH-WATER ALG# OF THE UNITED STATES. 39 


lulis perdurantibus interjectis, articulis vogetativis subequalibus, utroque polo punctiforme 
incrassatis, subsphericis; sporis subsphericis. 


Syn.—A. gigantea, Woon, Prodromus, Proc. Amer. Philos. Soc., 1869, 145. 
Hab.—In stagnis natante, prope Philadelphia. 


Diam.—Artic. vegetat. max. g7g'gy. Heterocysts gfyy = .0005. Spor. lat. ytdyg = Long. 
bo = -001 
1000 . 


Thallus wanting ; filaments occurring floating singly on water or in great numbers, straight, 
but in the young state often spirally convolute; articles mostly subglobose, closely connected, 
granular, heterocysts subspherical, interstitial, a very little larger than the vegetative cells, 
thickened at each end in a punctiform manner; spore subspherical. 


Remarks.—This plant was found by myself, late in the summer, floating upon a 
brick-pond below the city, forming a part of a thick, dirty-green, “ pea-soup 
colored,” almost pulverulent scum. The filaments, though occasionally in great 
numbers, were never, that I saw, joined together by any jelly so as to form a frond. 

Fig. 5, pl. 3, represents a short filament of this species magnified 750 diameters. 


Genus CYLINDROSPERMUM, Kzz. 


Spore ante cellulam terminalem orte. 


Spore developing from the next to the terminal cell. 


C. minutum, Woop. 

C. trichomatibus dilute xrugineis, plerumque flexuoso-curvatis et intricatis, interdum subrectis ; 
articulis cylindricis, ad genicula plus minus constrictis, homogeneis vel granulatis; cellulis 
perdurantibus terminalibus, hirsutis, globosis; sporis ellipticis, diametro 2—3 plo longioribus, 
subtilissime granulatis. 


Syn.—C. minutum, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, 126. 

Diam.—Artic. ypyq”’; spor. long. yyy" trans. goga”. 

Hab.—In stagnis prope Philadelphia. 

Filaments light eruginous-green, generally curved and intricate, sometimes straightish ; articles 
cylindrical, more or less constricted at the joints, homogeneous or granulate; heterocysts 


terminal, hirsute, globose; spores elliptical, 2—-3 times longer than broad, very minutely 
granulate. 


Remarks.—This species was found by myself at Spring Garden, New Jersey. 
With a number of other alge it formed a ferruginous-brown gelatinous mass, 
growing in a deep, shaded, very stagnant pool. In most instances the filaments 
were closely interwoven, and sometimes.formed minute greenish balls, just large 
enough to be visible to the unassisted’ eye. In other instances they were mixed 
up with various alge in little indefinite masses. There is apparently a stage in 
the life of the plant, when it consists of a single filament enclosed in a little cap- 
sule, for mixed in with the rest of the gelatinous scum were little microscopic, sub- 
globose masses, with a firm outer periderm and a single filament coiled up in the 
centre. The color of the filaments was generally a faint bluish-green, sometimes, 
however, with a yellowish tint. The spores were decidedly yellowish. 

Fig. 6, pl. 2, represents a fragment of a filament with the spore magnified 800 
diameters. 


40 FRESH-WATER ALG& OF THE UNITED STATES. 


C. flexuosum, (Ac.) RaBena. ; 

C. strato gelatinoso, saturate viride, indefinite expanso; trichomatibus equalibus, pallide vel 

saturate ceruleo-viridibus, pleruamque valde flexuosis et intricatis, sepius circinatim vel 

fasciatim convolutis, interdum subrectis, et fasciatim contextis; articulis oblongis, ad geni- 

cula plus minus contractis, homogeneis vel granulatis, distinctis; cellulis perdurantibus 

terminalibus, subglobosis, rare hirsutis, nonnunquam in trichomatis utroque fine; sporis 
oblongo-cylindricis, diametro 2—38 plo longioribus, distincte granulatis. 


Diam.—Spor. yyh5q” = .000416”; cell. veget. gayq” = .000166". 
Syn.—C. flecuosum, (Ac.) Raxsenuorst, Flora Europ. Algarum, Sect. IT. p. 188. 
Hab.—In locis irroratis, prope Philadelphia. 


Stratum gelatinous, deep green, indefinitely expanded; filaments equal, pale or deep bluish- 
green, mostly very flexuous and interwoven, often circinnately or fasciately convolute ; some- 
times straightish and in bundles; articles oblong, more or less contracted at the joints, homo- 
geneous or granulate, distinct; heterocysts terminal, subglobose, rarely hirsute, sometimes 
at both ends of the filament; spores oblong-cylindrical, 2 or 3 times longer than broad, dis- 
tinctly granulate. 


Remarks.—The color of the filaments in young specimens is deeper than in the 
older, which, however, grew in a much darker locality. The young spores are a 
yellowish-green, afterwards they are of a sort of yellowish reddish-brown. In one 
instance two spores were seen closely conjoined together at the end of a filament. 
In some filaments one or more heterocysts occur interstitially. Often one or more 
filaments will be seen coiled together like a rope. On the banks of the Schuyl- 
kill River I have found this species in two localities in the latter part of Sep- 
tember. In the one instance it grew along the Reading Railroad, just above the 
Flat Rock tunnel, in a dark little grotto, formed by shelving rocks. In the other 
case, it was on wet ground by a horse-trough very near the west end of the upper 
bridge at Manayunk. 

Fig. la, pl. 3, represents a filament, magnified 450 diameters. 

Fig. 16, a portion of a filament, magnified 800 diameters. 


— 


C. macrospermum, Krz. 
C. trichomatibus curvatis vel subrectis, pallide #rugineis; articulis cylindricis vel subcylin- 
dricis (in forma Europea “ globosis vel ellipticis”), ad genicula plus minus constrictis, 
passim confluentibus; cellulis terminalibus plerumque ellipticis vel ovatis, diametro paulo 
vel subduplo longioribus; sporis elliptico-oblongis vel oblongo-cylindraceis, viridibus (in 
formam Europeam maturam “saturate fuscis”), subtiliter granulosis, diametro duplo lon- 
gioribus. 
Diam —Trich. cell. transv. g¢y5” = .00003”; spor. .00046”—.00054”. 


Syn.—C. macrospermum, Krz. Rasenuorst, Flora Europ. Algarum, Sect. IT. p. 186. 

Hab.—In rivulis, South Carolina. (Prof. Ravenel.) 

Filaments curved or straightish, pale eruginous; articles cylindrical or subcylindrical (in 
European species ‘‘ globose or elliptical”), more or less constricted at the joints, here and 
there confluent; terminal cells mostly elliptical or ovate, a little longer or about twice as 


long as broad; spores elliptical-oblong or oblong cylindrical, greenish (in mature European 
specimens deep fuscous), finely granular, about twice as long as broad. 


Remarks.--I have received this species from Professor Ravenel, who collected 
it near Aiken, South Carolina, in the month of September ; with it was the follow- 


FRESH-WATER ALG&H OF THE UNITED STATES. 41 


ing note: “In bottom of shallow, slowly running streams, adhering to ground or 
fallen leaves, &c., gelatinous green.” ‘lhe specimens agree well with the descrip- 
tion of the European form, except that I have never seen the joints globose or ellip- 
tical, but always cylindrical, as they are said to be sometimes in the typical speci- 
mens. ‘The color of. the spores also is not ‘fuscous,” but that probably depends 
upon their not being fully mature. 

Fig. 7, pl. 2, represents the spore of this species with the neighboring hetero- 
cyst, magnified 750 diameters. 


C. comatum, Woop (sp. nov.) 


C. terrestre, stratum gelatinosum erugineum interdum brunneo tinctum, formans; trichomati- 
bus flexuosis, intricatis, haud spiralibus, equalibus; articulis breve cylindraceis, diametro 
eequalibus ad plus duplo longioribus, plerumque sejunctis, pallide erugineis, obscure granu- 
latis; cellulis terminalibus subglobosis ; sporis oblongo-cylindricis, diametro fere duplo longi- 
oribus, granulatis, luteo-brunneis ; membrana crassa, distincte granulata. 


Diam.—Spor. transv. yoy” = .00042”. Long. yagsg” = .00092”. Artic. .0001”. 
Hab.—In terra uda; Niagara, Canada. 


Growing on the ground, forming a gelatinous stratum of an eruginous color, sometimes tinged 
on edges with brown; filaments flexuous, equal, intricate, not spiral; joints shortly cylin- 
drical, equal to or more than twice as long as the diameter, mostly separated, pale eruginous, 
obscurely granulate, terminal cells subglobose; spores oblong-cylindrical, about twice as 
long as broad, granulate, yellowish-brown; membrane thick, distinctly granulate. 


Remarks.—I found this Cylindrospermum growing upon the ground in the 
marshes which border the Niagara River just above the Canadian Falls. It formed 
a bright, eruginous, gelatinous, but firmish, almost membranous, stratum. 

The filaments are often quite long, and are composed of short, cylindrical cells, 
mostly placed rather far apart. ‘The terminal cells are remarkable for being abun- 
dantly provided with long, flexible, hair-like processes, upon the ends of which are 
minute lobular bodies (cells?). These appendages are so minute as to make it diffi- 
cult to determine their structure, and although I have studied them with a ,,th 
immersion lens, giving a power of nearly 2500 diameters, there are some points 
about them still undetermined. I do not know whether they or the little globules 
are hollow or not. I do feel pretty certain, however, that the little globules are 
distinct bodies, and that they finally drop off, leaving the naked hair behind. Is 
it possible that they have any sexual significance? The spore-wall is thick, and 
under a high power is seen to be distinctly granulate. ‘The granules are of course 
small, but in the perfected spore can plainly be seen with an eighth objective pro- 
jecting out from the margin. 

Fig. 8, pl. 2, represents the spore-end of a filament, magnified 1875 diameters. 


Genus DOLICHOSPERMUM, Tuwaites. 


Spore elliptic, oblonge vel cylindracez, inter cellulas vegetativas orte, sepe in seriebus con- 
nexe, a cellulis perdurantibus disjuncte. 


Spores elliptical, oblong, or cylindrical, occurring amidst the vegetative cells, often connected in 


series, separated from the heterocysts. 
6 April, 1872. 


42 FRESH-WATER ALG#& OF THE UNITED STATES. 


Syn.—Spherozyga, (AuctTorEs, partim.) ; 
Dolichospermum, Tuwarre’s MSS. Mr. J. Raurs on the Nostochinex, Ann. Mag. 
Nat. Hist. 1850, p. 335. 


Remarks.—This genus differs from Sphewrozyga in that the spores have no rela- 
tion, in regard to position, with the heterocysts. Professor’ Rabenhorst, in his 
Flora, does not acknowledge it; but it is very evident that he has neither seen 
the original paper of Mr. Ralfs, nor the species upon which the genus was founded, 
for he mentions none of the latter, either as good species or synonyms, and the 
memoir itself is not included in his bibliographical list. The generic characters 
given by myself are essentially those of the original description, with the excep- 
tion that the filaments in the latter are said to be aggregated into a stratum, which 
is not true of the American forms herein described. 


D. subrigidum, Woop. 

S. natans; trichomatibus singulis, rectis aut subrectis, minimis, dilute viridibus: articulis 
cylindraceis aut subglobosis, distinctis; sporis cylindraceis, in medio gradatim nonnibil 
constrictis, singulis aut duplicis, sine cellulis perdurantibus inter se; cellulis perdurantibus 
breve cylindraceis, singulis, distinctis. 


Syn.—Spheroziga subrigidum, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, p. 123. 

Diam.—Cell. veg. trans. gyyy” = .00016”; spor. transv. g355/—ayon” = -00023"” —.00022” ; 
long. yoo” = -00066”; cell. perd. transv. gg” = .00022”. 

Hab.—In stagnis prope Philadelphia. 

8. Floating; filaments single, straight or straightish, very small, light green; articles cylin- 
drical or subglobose, distinct; spores single or double, in the middle gradually a little con- 


stricted, not having a heterocyst between them; heterocysts shortly cylindrical, single, 
distinct. 


Remarks.—I have found this species growing in the scum floating upon the 
ditches below the city. The filaments are always, as I have seen them, scattered. 
They seem always to be nearly straight, or entirely so, and indeed preserve their 
straightness so constantly as to suggest the name given the species. The spores are 
very distinct, and all that I have seen were greenish, cylindrical, and constricted in 
the middle, so that their sides are concave. Their position does not seem to be 
uniform, any further than that they are amongst the ordinary cells. The heterocysts 
are large, almost equalling the spores in diameter; I have never detected hairs on 
them. This species appears to be most nearly allied to D. Thwaitesii of Ralfs, from 
which it differs in not forming a stratum, and in the great proportionate diameter 
of the heterocysts. I have never seen any measurements of D, Thwaitesti. 

Fig. 2, pl. 3, is a filament, magnified 975 diameters. 


D. polysperma, (Krz.) 

8. trichomatibus pleramque subsolitariis, sed interdum consociatis et intricatis, dilute ceruleo- 
viridibus, subrectis aut varie curvatis et flexuosis; articulis aut subsphericis aut breve cylin-! 
dricis; cellulis perdurantibus globosis aut latissime ellipticis, articulorum diametro paulo 
vel duplo majoribus; sporis plus minus elongatis, cylindraceis—in tate immatura, sparse 


granulatis, dilute ceruleo-viridibus, et cum membrana haud distincta,—in etate matura dense 
granulatis et cum membrana subcrassa. 


FRESH-WATER ALG OF THE UNITED STATES. 43 


Diam.—Artic. gjo5" = 00016" ; spor. r5$55"—rz $00" = -00026"—.00038”. 
Syn.—S. Carmichelii, Harvey, Phycol. Brittanica, T. cxiii. 

S. polysperma, (Krz.) RasBxEnuorst, Flora Europ. Algarum, Sect. II. p. 192. 
Hab.—In stagnis, New Jersey. 


8. filaments mostly subsolitary, but sometimes associated and interwoven together, light bluish- 
green, straightish, or variously curved and flexuous; articles either subspherical or shortly 
cylindrical ; heterocysts globose or very broadly elliptic, a little larger to twice as large in 
diameter as the ordinary joints ; spores more or less elongate, cylindrical, in the uncertain 
condition sparsely granulate, light bluish-green, with the membrane not distinct, in the 
mature state densely granulate, and with a thickish membrane. 


Remarks.—I found this species growing in a brownish jelly, with various other 
alge, in a. pool east of Camden, New Jersey. The filaments were mostly scattered, 
but in some places numbers of them were collected in little masses. In some fila- 
ments almost all the cells were developed into spores, so that a single thread con- 
tained ten or even more spores. In by far the larger number of such cases there 
was between each pair of spores a heterocyst; sometimes, however, the latter was 
wanting, and the spores would be attached to one another. 

My specimens differ somewhat from the European form, but are too close to 
separate from them. ‘They equally resemble, however, S. Carmichelii. Indeed, I 
cannot see any sufficient reason for separating the species. &. Carmicheelii is, to 
be sure, a salt-water plant. I have, however, received specimens collected by Dr. 
Lewis, near Stonington, which I believe grew in salt water, and which agree in 
every respect with my fresh-water specimens. 

Fig. 3, pl. 3, represents a portion of a filament, magnified 750 diameters. 


Famity RIVULARIACEA. 


Thallus gelatinosus, mollis vel induratus, vel crustaceus, interdum calce impletus, subglobosus 
velamorphus. ‘Trichomata ad oscillarium morem articulata, vaginata, sed interdum state provecta 
cum vaginis in gelatinam matricalem confluentibus et haud visibilibus, simplicia vel pseudoramosa, 
superne attenuata, sepius in apicem piliformem longe producta, parallela vel radiatim disposita, 
cellula basale hyalina globosa et interdum cellulis interstialibus instructa. Spore (manubria, Krz.), 
singule plerumque inter cellulam perdurantem basilarem et cellulas vegetativas posite, seepe per- 
magne, cylindrice, plerumque pachydermatice. 

Vegetatio terminalis. Propogatio sporis tranquillis. 


Thallus gelatinous, soft, or indurated, or crustaceous, sometimes filled with lime, subglobose or 
amorphous. Trichomata. articulated like an oscillatoria, vaginate, but sometimes, when old, with 
the sheaths confluent in the maternal jelly and not visible, simple or pseudoramose, attenuated 
above, often with the apex prolonged into a long hair, parallel or radiately disposed, furnished with 
globose hyaline, thick-walled basal cells, and sometimes with interstitial cells. Spores cylindrical, 
generally placed between the basal and vegetative cells, often very large, mostly with thick coats. 

Vegetation tranquil. Propagation by means of tranquil spores. 


Remarks.—In the Rivulariacee the thallus is always small; but is most gene- 
rally in the various species somewhat definite in form and size. Its consistency in 
our North American forms varies from that of an exceedingly soft, formless jelly 
to that of a gristly mass. The maternal jelly is usually colorless, sometimes brown- 
ish or yellowish. There is never any condensation of the outer portion of the 


44 FRESH-WATER ALG OF THE UNITED STATES. 


frond into a periderm. The filaments commonly radiate from the centre to the 
circumference ; sometimes, especially in the softer fronds, they are simply parallel 
with one another. The sheaths vary in their breadth, firmness, and distinctness. 
These little plants grow chiefly in the water; some species are said to live in 
the air in exceedingly damp places, but I have not as yet met with any such. 
They appear to prefer cold climates, although I have received specimens from 
South Carolina, With us, I have only found them in the late autumn and winter 
months. As to their life-history very little appears to be known; I have not been 
able to make any observations myself upon this point, nor to obtain access to the 
papers' by De Bary, almost the only sources of such information, and therefore 
pass by the subject. 


Genus NOSTOCHOPSIS, Woop. 


Trichomata ramosa cum cellulis perdurantibus aut in lateribus sessilibus aut in ramulorum brevissi- 
morum apicibus dispositis. Vagine nullx. Thallus definitus. 


Syn.—WNostochopsis, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869. 


Thallus definite; filament branched ; heterocysts sessile upon the sides of the filaments, or raised 
upon the apices of short branches; sheaths none. 


Remarks.—The curious plant upon which this genus is founded has the habit 
of anostoc. The outer portion of the frond is condensed, so as to give the appear- 
ance of a periderm; but there is, in reality, no true periderm. The consistence 
of the thallus is that of a firm, gelatinous mass. ‘The trichomata or filaments 
radiate from the inner part of the frond towards the outer surface, but many of 
them take their origin in the outer portions of the thallus. In most places they 
are distinctly articulated, and, indeed, the joints being swollen and moniliform, in 
some parts they almost seem to be composed of globular cells, resembling some- 
what the filaments of a nostoc; on the other hand, in certain portions they are not 
at all articulated, and this for long distances. No sheaths are anywhere visible. 
The heterocysts are, strangely enough, never placed in the continuity of the fila- 
ments. Sometimes they are sessile immediately upon the latter, sometimes they 
are raised upon very short branches. They are globose, with rather thick walls. 
Possibly, however, I am mistaken in believing these bodies to be heterocysts, for 
they may be rather of the nature of spores, as is somewhat indicated by their 
thick walls, and often apparently dense contents. ‘Their round shape, and the 
absence of anything else representing heterocysts, has induced me, however, so to 
consider them. In my Prodromus I placed this plant provisionally amongst the. 
nostocs; but the radiation of the filaments from within outwards, and especially 
their being branched, on second thought seem to me to indicate a closer relation 
with the Rivulariacew. ‘The genus appears to be a sort of connecting link be- 
tween the two families. 


+“ Flora,” 1863. 


FRESH-WATER ALGH OF THE UNITED STATES. 45 


WN. lobatus, Woop. 


N. thallo vivide viride aut luteo-viride, cavo, enormiter lobato, natante, modice magno, firmo, 
gelatinoso ; trichomatibus plerumque longis, flexuosis, dilute viridibus, pleruamque articulatis, 
partim inarticulatis, cylindricis aut sub-moniliformibus, sparse granulatis. 


Diam.—Trichom. rsto0 = -00006"—7A5y” = .00013” ; cell perdum. 37Eo_ = .00026”. 
Syn.—WN. lobatus, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869. 
Hab.—In Schuylkill Flumine, prope Philadelphia. 


Thallus bright green or yellowish-green, hollow, irregularly lobed, floating, moderately large, 
firm, gelatinous ; filaments mostly long, flexuous, dilute green, mostly articulate, partly inar- 
ticulate, cylindrical or somewhat moniliform, sparsely granulate. 


Remarks.—I found this plant floating upon the Schuylkill River just above 
Manayunk. The hollow frond was buoyed up by a bubble of gas contained within 
it. It was an irregular, flattened, somewhat globose mass, of a bright green color 
and about half an inch in diameter. It seems very probable that in its earlier 
condition, it was a solid attached frond. The long slender filaments are often very 
tortuous, but run a pretty direct general course towards the outer surface. 

Fig. 6a, pl. 3, represents a section of the frond slightly magnified; a, b,c, por- 
tions of filaments magnified 800 diameters. 


‘Genus GLOIOTRICHIA, J. Ac. (1842.) 


Trichomata e planitie orta pseudoramosa, distincte vaginata; vagine ample, basi plerumque 
saccate, transverse undulato-plicate, plus minus constrictz, apice aperte, non laciniate. Spore 
magne cylindrica. 

Filaments springing from a plane, pseudoramose, distinctly vaginate; sheath ample, mostly 
saccate at the base, transversely undulately plicate, more or less constricted, open at the apex, 
not laciniate. Spores large, cylindrical. 


Remarks.—This genus was, I believe, first indicated by Professor Agardh in 
his Alge Maris Mediterranei et Adriatici, a work to which I have not access. 
On account of this, and also because I have not seen any of the typical species 
of the genus, I have preferred simply copying the generic characters given 
by Professor Rabenhorst. If my understanding of “e planitie orta” is cor- 
rect, 1 do not think it true. Professor Rabenhorst’s own figure of Rivularia 
shows that the filaments do not all arise on one plane; although he asserts the 
character equally for that genus. In our American species the filaments do not 
all arise on one plane, nor can they be spoken of as “ pseudoramosa.” 


G. incrustata, Woop. 

G. globosa vel subovalis, firma, solida, ad pisi minimi magnitudinem, dilute viridis, crystallo- 
phora; trichomatibus rectis aut leviter curvatis, in pilum productis, viridibus aut flavescen- 
tibus, seepe infra lete viridibus sed supra flavescentibus, haud ordinatim articulatis; articulis 
inferioribus in trichomatibus maturis brevibus, plerumque compressis; pilo apicale recto aut 
leviter curvato, plerumque indistincte articulato, sepe interrupto; vaginis amplis, achrois, 
saccatis, interdum valde constrictis ; sporis cylindricis, sepe curvatis, diametro ad 9 plo lon- 
gioribus ; cellulis perdurantibus sphericis. 


46 FRESH-WATER ALGA OF THE UNITED STATES. 


Diam.—Trichom. cum vag. 7255"—7255"; Sporis max. 7455"—7e455"; cell. perd. rgZa0". 
Syn.—G. incrustata, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, p. 128. 
Hab.—Schuylkill River, plantas aquaticas adherens. 


Frond globose or suboval, firm, solid, about the size of a very small pea, light green, crystal 
bearing ; filaments straight or slightly curved, produced into long hairs, green or yellowish, 
sometimes bright green in their proximal portions but yellowish above, not regularly articu- 
late; lower articles in the mature filament short, and generally compressed; apical seta 
straight or slightly curved, mostly indistinctly articulate, frequently interrupted; sheath 
ample, transparent, saccate, sometimes strongly constricted; spores cylindrical, frequently 
curved, about 9 times as long as broad. 


Remarks.—I found this species growing attached to some little plants, either in 
the Schuylkill near Spring Mills, or else in the spring itself, I do not know which. 
The roundish fronds varied in size from a mustard-seed to that of a half-grown 
pea. They were of a decided green color, but appeared grayish from the amount 
of carbonate of lime in and upon them. ‘The larger balls, when cut in two, were 
distinctly separable into a central and cortical part. The former was more gela- 
tinous and contained fewer of the filaments than the latter. The filaments mostly 
arose in sets together, i.e. there were one or more zones or planes in which the 
bases of the filaments were placed together. This, however, was not strictly the 
case, as there were almost always some scattered trichomata.. The matured fila- 
ments are very distinct. ‘Their sheaths are very large, and often saccate, with 
wavy, loose-looking margins ; sometimes they are suddenly transversely constricted, 
once or more in their length; sometimes they look as if a tight spiral band were 
wound around; sometimes they are entirely tree from any constrictions. These 
sheaths are open above, appearing as though they had been melted away. The 
spore is long and cylindrical, and is highly granular. The endochrome is gene- 
rally articulated below, the joints are often so nearly globular in the lower portions 
as to give a moniliform appearance; sometimes the articles are compressed. The 
upper portion of the trichoma is frequently interrupted, and if at all articulated 
is very irregularly and indistinctly so. The younger filaments have their endo- 
chrome variously and irregularly interrupted. The basal cells are globular. I 
believe the formation of new filaments and the consequent growth of the frond 
take place by distal portions of the projecting endochrome separating from the 
parent filament, then forming a basal cell, and lastly a sheath. (See Plate 00.) 
The carbonate of lime does not exist as a definite incrustation, but in the form of 
semi-crystalline masses scattered through the frond. This species seems to come 
closer to G. boryana than any described species, from the description of which it 
differs, in the color of thallus, in the latter being always solid (at least so I have 
found it late in the fall, when the spores were fully perfected), in its habit of in- 
closing crystals of carbonate of lime, in the curved spores; and, doubtless, a com- 
parison of the specimens would show still more important differences. 

Fig. 4a, pl. 3, represents a section of a frond moderately magnified; fig. 43, 
the basal end of a filament magnified 460 diameters; fig. 8c, filaments magnified 
260 diameters. 


FRESH-WATER ALG OF THE UNITED STATES. 47 


G. angulosa, (Rors.) J. Aen. 

G. globoso-angulosa, cava, viridi-fuscescens, ad cerasi magnitudinem; trichomatibus strictis, 
torulosis, superne leviter flexuosis, passim interruptis; articulis inferioribus plus minus 
compressis, diametro duplo triplove longioribus ; vaginis amplis, achrois hic illic leviter con- 
strictis; sporis plus minus elongatis, oblongo-ovatis vel ellipsoideo-cylindricis, diametro 3—-6— 
10 plo longioribus, wrugineo-fuscescentibus, nonnunquam leviter curvatis, cytioplasmate sub- 
tiliter granuloso, turbato. (R.) Species mihi ignota. 

Diam.—Cell. perd. 0.00036”—0.0005". Spor. max. 0.00059" (R.) 

Syn.—G. angulosa, (Roru.), J. AGARpH., RaBenuorst, Flora Hurop. Algarum, Sect. II. p. 201. 

Hab.—Hudson River prope West Point. (Bailey.) 

Globose angular, hollow, greenish-fuscous, attaining the size of a cherry ; filaments strict, toru- 
lose, above somewhat flexuose, here and there interrupted ; inferior joints more or less com- 
pressed, 2-3 times longer than their diameter; sheath ample, colorless, here and there slightly 
constricted; spores more or less elongate, oblong-ovate or ellipsoidal-cylindrical, 3-6-10 
times longer than the diameter, eruginous-fuscous, sometimes slightly curved, cytioplasm 
very minutely granulate. 


Genus RIVULARIA, (Rorz.) Acu. 


Thallus et trichomata eadem que Gloiotricha, sed vagine arctissime, sepe in gelatinam matri- 
calem confluentes, quasi nulle. 


Thallus and filaments similar to those of Gloiotricha, but the sheaths very close, often confluent 
in the gelatinous matrix and apparently wanting. 


Remarks.—The characters given above are those of Professor Rabenhorst. 
Flora Europ. Algarum, Sect. I]. p. 206 


R. cartilaginea, Woop. 


R. subglobosa, parva, cartilaginea, saturate brunnea vel subatra, solitaria in plantis aquaticis :— 
trichomatibus maturis-sterilibus, rectis aut subrectis, cylindricis, elongatis, haud articulatis ; 
cytioplasmate sepe interrupto; vaginis arctis et distinctis; cellulis perdurantibus globosis, 
diametro subequalibus :—trichomatibus fertilibus—rectis aut subrectis, supra spora cellulis 8-9 
instructis; sporis elongatis, rectis, cylindricis; vaginis nonnihil crassis, arctis :—trichomatibus 
immaturis breve articulatis; vaginis subamplis. 

Diam.—Trich. cum vag. gq'g9”5 spor saga”: 

Syn.—R cartilaginea, Woop, Proc. Am. Philos. Soc., 1869, p. 128. 


Hab.—In palude, Northern Michigan. 


Frond subglobose, small, cartilaginous, deep brown or blackish, solitary upon aquatic plants; 
mature sterile filaments, cylindrical, elongated, not articulated, their cytioplasm frequently 
interrupted, their. sheaths close and distinct, their heterocysts globose and about equal to 
them in diameter; fertile filaments straight or nearly so, above the sporcs furnished with 8 or 
9 cells; spores elongate, straight, cylindrical; sheaths rather thick, close; immature filaments 
shortly articulate, their sheaths rather large. 


Remarks.—The frgnd of this species grows attached to the leaves of water-plants, 
and has its under side markedly flattened so that it is somewhat semi-globose. The 
filaments which compose the mass of the very firm frond are elongated, cylindrical, 
and of nearly or entirely uniform diameter throughout. The sheaths are close, 
distinct, rather thin, open above, and, in many instances, almost or even entirely 
empty. Scattered amongst such filaments are the fertile ones. These have at 
their base an elongated cell, in which is the long cylindrical spore, which varies 


48 FRESH-WATER ALG& OF THE UNITED STATES. 


very greatly in length in the various filaments, but is almost always shorter than 
the cell containing it. Just beyond the spore is a series of distinct, variously 
shaped cells, about seven in number, which are, as I have seen them, empty. In 
the outer portions of the frond occur what I believe to be young filaments. These 
are distinguished by their rapidly decreasing in diameter towards their distal end, 
by their being distinctly articulated, by their basal cell not being distinctly sepa- 
rated as in the older filaments, and by their sheaths being more ample. 

These various filaments composing the fronds do not arise from any one place, 
but commence at very different distances from the centre, and pursue a more or 
less straight course to the circumference of the frond, from which they often project. 

Fig. 9, pl. 2, represents a section of the frond moderately magnified ; fig. 9 8, is 
a drawing of the basal part of a filament magnified 800 diameters. 


Genus ZONOTRICHA. 


Thalli pulvinato-hemispherici, sepe confluentes, calce pregnantes, plus minus indurati, basi plani 
affixa, etate provecta plerumque excavati, intus zonati; zonis concentricis, variegatis; trichomata 
pseudoramosa, gracilia, inequalia, apice hyalina et plus minus longe cuspidata vel in pilum producta. 
Vagine firme, homogenee vel longitudinaliter plicato-fibrillose, apice integre vel dilatate et in 
fibrillas solute. Spore ignote. 


Thalli pulvinately hemispherical, often confluent, impregnated with lime, and more or less indu- 
rated, fixed by the flattened base, in advanced age mostly excavated, zoned within; zones concentric 
variegated ; filaments pseudoramose, slender, unequal, their apices hyaline and more or less cuspid- 
ate or prolonged into a hair; sheaths firm, homogeneous, or longitudinally plicately fibrillose, their 
apices entire or dilated and dissolved in fibrille. Spores unknown. 


Z. mollis, Woop (sp. nov.) 


Z. interdum subhemispherica sed gregaria et in stratum nonnihil mammillosum confluens, 
submollis, cinerea vel griseo-carnea, parcezonata; trichomatibus longissimis, angustis, 
flexuosis; vaginis arctis, decoloratis, non fibrosis, firmis; trichomatibus internis articulatis, 
sepe interruptis; articulis disjunctis, diametro equalibus ad 4 plo longioribus; cellulis 
perdurantibus singulis globosis. 

Diam.—Trich. ¢. v. pg2gq” = -00017". Sine vag ys355// = .000084". 

Hab.—In saxis irroratis, ‘Cave of the Winds,” Niagara, Wood. 

Z. sometimes subsemispherical but gregarious and confluent into a somewhat mammillate, rather 
soft stratum, ashy or grayish flesh-colored, sparsely distinctly zoned; filaments very long, 
narrow, flexuous; sheaths close, colorless, not fibrillose, firm; internal filament articulated, 


often interrupted ; joints separated, equal to 4 times longer than the diameter ; heterocysts 
single globose. 


Remarks.—Every American tourist is familiar with that most wonderful spot, the 
so-called “Cave of the Winds,” at Niagara. It is simply a place where it is possible 
to go underneath a portion of the great cataract, and then round upon the rocky 
debris outside of it. Growing upon these rocks, eternally wet and glistening with 
foam and spray, I found this and the following species. The present form was 
much the most abundant, making a slippery, grayish, or grayish flesh-colored coat- 
ing to many of the rocks, dotted here and there with the rigid, blackish fronds of 


FRESH-WATER ALGHA OF THE UNITED STATES. 49 


its fellow. This coating was not at all uniform, but was covered with mammillated 
masses, and consequently varied from two to six lines in thickness. Internally, it 
was striated or radiated, but not so evidently as the following species, and presented 
several distinct variegated zones. It was quite soft to the touch, as well as readily 
broken or crushed, and under the microscope was seen to contain very little lime 
salt. When dried it has a pronounced sebaceous appearance. The filaments com- 
posing it are remarkable for their great length, often apparently running from the 
bottom to the top of the frond. They are rarely if ever branched, and appear 
never to be furnished with any heterocysts save at their enlarged base. I have 
never seen any distinct hairs terminating them, their ends always appearing broken 
and open, They are often quite flexuous or even tortuous. The internal filament 
is remarkable for having its articles so distinctly separated. It is often very much 
interrupted, and in specimens preserved in carbolic-acid water is of an orange-brown 
color. 
Fig. 3, pl. 4, represents a single filament magnified 260 diameters. 


Z. parcezonata, Woon, (sp. nov.) 

Z. nigro-viridis, enormiter semiovalis, ad 6” longa, dura, lubrica, non fragilis, calee pregnans, 
intus a basi distincte radiata, parce et sepe obsolete zonata; trichomatibus modice longis, 
subrectis; trichomatibus internis cylindricis inarticulatis vel articulatis, et interdum monili- 
formibus ; articulis longis et cylindricis vel brevibus et globosis; vaginis amplis, fibrillosis; 
cellulis perdurantibus basalibus et interjectis, his oblongis vel cylindricis, illis globosis et 
sepe geminis. 


Diam.—Cell. perd. basal. gpg =.00017” ; trichom. cum vag. gogo" —sgiyq" =. 00025" —.00087". 
Sine vag. .00006”—.00008”. 

Hab.—In saxis irroratis. “Cave of the Winds,” Niagara. 

Var.—Z. cinerea. 

Blackish green, irregularly semioval, to 6 lines long, hard, slippery, not fragile, impregnated with 
lime, internally distinctly radiate, sparsely and often obsoletely zoned; filaments moderately 
long, straightish ; internal filament cylindrical, not articulated or articulated, sometimes monili- 
form; joints long and cylindrical, or short and subglobose; sheath ample, fibrillose ; heterocysts 
basal and interposed in the body of the filament; the former globose, often geminate; the 
latter oblong or cylindrical. 


Var.—Cineritious in color. 


Remarks.—I found this plant growing on rocks as glossy, blackish, very hard and 
slippery fronds or masses, which varied in size from that of very small shot to 
nearly half an inch in length. The larger ones were not nearly so high as long, 
and presented irregular, almost bossellated upper surfaces. The filaments are 
often very evidently and frequently pseudoramose. The external surface of the 
broad sheath is covered with numerous fibrille, which envelop and seem sometimes 
to wrap it round and round. The color of the frond internally, when broken, is 
mostly a dark chocolate, and the surface presents a radiated appearance, with but 
two or three zones at most, and, in the very dark specimens, even these are not 
evident. No signs of spores have been found. Certain specimens which I ob- 


tained growing with the others, instead of being blackish in color, are grayish, but 
vd April, 1872, 


50 FRESH-WATER ALG&Z OF THE UNITED STATES. 


agree in all other respects with their fellows. This gray color depends, I believe, 
upon the deposit of an immense quantity of lime salts, which in such specimens, 
constitute by far the larger portion of the frond. 

Fig. 4, pl. 4, represents a section of frond, slightly magnified. 

It is either this, or the preceding species, which is referred to by Professor 
Bailey in Silliman’s Journal, vol. iii, under the name of Rivularia calcarea, Sm. 
The present form may possibly be that plant, but not having been able to find any 
description sufficiently well made out to make identification possible, I have de- 
scribed both species as new. 


Z minutula, Woop, (sp. nov.) 

Z. minutissima, nigro-viridis, subglobosa, haud distincte zonata, nonnihil mollis, muscicola, calce 
non pregnans; trichomatibus internis, breve articulatis, distinctissime fasciculatim pseudora- 
mosis; vaginis crassis, amplis, sepe dilute aurantiaco-brunneis, apice plerumque coloris 
expertibus fissis et apertis; cellulis perdurantibus ovato-globosis. 

Diam.—Trich. intern. .00012”—.00021” ; cell. perd. .00025.” 

Hab.—In lacu, “ Clear Pond,” muscis affixa, Adirondack Mountains. 


Very small, blackish-green, subglobose, not distinctly zoned, rather soft, growing on mosses, not 
impregnated with lime; internal filaments shortly articulate, very distinctly fasciculately pseu- 
doramose; sheaths thick, ample, often pale orange-brown, with their apices mostly colorless, 
torn and open; heterocysts ovately globose. 


Remarks.—The locality in which I found this plant is in the heart of the Adi- 
rondack wilderness. ‘The little frond in none of my specimens is larger than a 
mustard-seed, and is not distinctly zoned. The plants were collected in the begin- 
ning of July, and very possibly are not fully grown, as the season of general growth 
opens very late in its parent lake. Very possibly, later in the year, it may be found 
larger and distinctly zoned. The general appearance of the plant, the character 
of its sheath, and the marked branching habit of the filaments have caused me to 
place it in this genus. 


Genus DASYACTIS, Krz. 


Thallus gelatinosus, mollis, non zonatus. Trichomata matura sepe haud vaginata. Spore 
nulle. 


Thallus gelatinous, soft, homogeneous, not zoned. Mature filaments often not vaginate. Spores 
absent. 


D. mollis, Woop. 


D. parva, ad magnitudinem pisi minimi, enormiter subglobosa, mollis, gelatinosa, dilute viridis: 
trichomatibus plerumque subrectis, partim distincte, partim indistincte artionlatie: vaplate, 
in trichomatibus maturis haud visibilibus, in trichomatibus juvenibus supra subamplis: cel- 
lulis perdurantibus sub-globosis, globosis, vel ellipticis, diametro duplo majoribus ploy ue 
singulis sed interdum bi vel triseriatis, % 


Diam.—Trich. ggo5"—agy5”; cell. perd. roo 
Syn.—D. mollis, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, p. 128. 


Hab.—In palude plantas aquaticas adherens, Northern Michigan. 


FRESH-WATER ALGH OF THE UNITED STATES. 51 


Frond small, about the size of a small pea, irregularly subglobose, soft, gelatinous, light green ; 
filaments generally straightish, partly distinctly, partly indistinctly articulate ; sheaths in the 
mature filament not perceptible; in the young filaments rather large in the upper portion ; 


heterocysts subglobose or globose or elliptic, twice as large as the filament, generally single 
but sometimes bi or tri-seriate. 


Remarks.—I found this species growing attached to the little leaves of various 
minute cryptogamic and phaneerogamic water-plants,-in a small bog, near the 
mouth of Carp River, in Northern Michigan. The frond is somewhat translucent, 
with a slightly greenish tint, and has a soft, gelatinous consistency. The matured 
trichoma or filaments are more or less radiating, very long, generally nearly straight 
and parallel. Their joints or articles are long, mostly not very distinctly separated, 
and often are entirely wanting. ‘The sheaths are entirely lost, no traces of them 
being perceptible. They seem to be altogether melted down into the homoge- 
neous jelly, in which the filaments are imbedded. The basal cell is large, mostly 
globular, and very prominent. On the edges of the frond may frequently be seen 
small, evidently immature filaments, which have no distinct basal cell. Around 
the basal portion of these young trichoma there is a well-marked close sheath, 
which near the apex is wanting. In their immature filaments the joints are mostly 
very short, rather distinctly separated, almost globular. 

Fig. 5, pl. 4. 


Genus MASTIGONEMA, Scuwass. 


Trichomata articulata, sursum flagelliformia vel subulata, simplicia vel pseudoramosa (nonnunquam 
fasciculatim pseudoramosa), procumbentia vel erecta, in thallo indistincto caspitoso-aggregata; 
vagine arcte et homogenee vel ample et plus minus distincte lamellose, apice plerumque aperte, 
interdum laciniate. 


Filaments articulate, superiorly flagelliform or subulate, simple, or falsely branched, sometimes 
fasciculately so, procumbent or erect, cespitosely aggregated into a sort of thallus; sheaths close 
and homogeneous or ample, and more or less distinctly lamellate, the apex for the most part open, 
sometimes laciniate. 


M. fertile, Woop, (sp. nov.) 

M. cespitosum, cum algis alteris intermixtum; trichomatibus simplicibus, elongatis, flexuoso- 
curvatis, apice truncatis; trichomatibus internis viridibus, seepe interruptis, interdum dis- 
tincte articulatis interdum inarticulatis; articulis diametro 3-5 plo longioribus; vaginis modice 
arctis, firmis, achrois, crassis, coloris expertibus, apice truncatis et apertis ; sporis cylindricis, 
sparsis, in filamento unico sepe pluribus, in cellulis inclusis; cellulis perdurantibus globosis, 
interdum compressis trichomatis diametro fere equalibus. : 


Diam.—Filam. x55" = .00033" 5 spor. gayq” = .000166". 
Hab.—In stagnis. Alleghany Mountains, Centre County, Pennsylvania. 


Cespitose, intermixed with other alge; filaments simple, elongate, flexuously curved, trun- 
cate at the apex; internal filament green, often interrupted, sometimes articulated, some- 
times not articulate; joints 2-3 times longer than théir diameter; sheath moderately close, 
thick, firm, transparent, and colorless, truncate and open at the apex; spores cylindrical, 
scattered, each contained in a cell, frequently several in a filament; heterocysts globose, 
sometimes compressed, about equal in diameter to the filament. 


52 FRESH-WATER ALG& OF THE UNITED STATES. 


Remarks, —I found this plant in a stagnant pool in “ Bear Meadows,” forming a 
filamentous, felty mass with Gidogoniwm echinatum and other alge. ‘The variously 
curved and interlaced flexible filaments are always simple and of uniform, or 
nearly uniform, diameter through their whole length; excepting that in some 
instances there are small, local, bulbous enlargements of the sheath. Though the 
ends of the filaments in all the specimens I have seen are abruptly truncate, it is 
very possible that in the young trichoma the apex is prolonged into a long hair as 
in most of the Mastigonema. The inner filament is sometimes very distinctly arti- 
culated, often, however, it is not at all so. The sheaths are firm, not at all lamel- 
late, and generally project beyond the inner trichoma. The spores are cylindrical, 
yellowish, with a pretty distinct, although very close coat. They are always in- 
closed in distinct cells, and are mostly several in a filament, placed at intervals in 
its length. 

This is the first instance, at least that I know of, in which a species of this 
genus has been found in fruit, and it is interesting to note the resemblance of the 
spores to those of the more commonly fruiting rivularias. At the same time the 
peculiar arrangement of the spores is remarkable, and if the other species of Mas- 
tigonema should be found to have the more common exclusively basal arrangement 
of spores, I think it would afford good ground for considering M. fertile as the type 
of a new genus. Moreover, the filaments are not united into a distinct thallus, and 
also want the apical hair of Mastigothria, so that it is very probable that they represent 
an undescribed genus. Until, however, the fructification of the European species 
is elucidated, it seems best to forbear multiplying names. 

Fig. 1, pl. 4, represents a single filament of this species. 


MI. halos, Woop, (sp. nov.) 


M. cespitulis; trichomatibus simplicibus, in etate matura valde elongatis et cum vaginis trun- 
eatis et apertis,—in state immatura modice brevibus et in setam modice longam achroam 
productis; trichomatibus internis breve articulatis, subtiliter granulatis continuis vel varie 
interruptis ; vaginis firmis, modice crassis, sepe distincte lamellosis, coloris expertibus ; cel- 
lulis perdurantibus subglobosis 


Diam.—Sine vag. = .0003”; cum vag.= .0005”. 

Hab.—In estuario, Stonington, Conn. (Dr. F. Lewis.) 

In little tufts; filaments simple, in mature state greatly elongate, and with the sheath truncate 
and open,—in the young condition shorter and often ending in a rather short seta; internal 


filament shortly articulate, minutely granular, continuous or variously interrupted; sheath 
firm, rather thick, often distinctly lamellated, colorless ; heterocysts subglobose. 


Remarks.—This species is an inhabitant of salt, or at least brackish water, having 
been collected in Stonington Inlet by Dr. Frank Lewis. The filaments are very 
long and always simple; forming apparent exceptions to this, I have seen once or 
twice a number of young filaments so united as to give the appearance of having 
been produced from one old one, and in other cases young filaments growing from 
the side of an old one; but I believe those are always set free so soon as they 
attain a certain size. In one instance there were large, globular cells, with very 
thick walls, produced, and lying free, in the sheath. Are these spores? They are 


FRESH-WATER ALG OF THE UNITED STATES. 53 


well shown in figure 2, pl.5. Associated with them were a number of similar cells 
which had not obtained as yet the outer thick wall. ‘The color of the filaments is 
in my specimens of a rich golden brown; but, as they have been preserved in car- 
bolic acid water, I cannot speak positively as to the original tint. The heterocysts 
are subglobose, sometimes compressed, sometimes somewhat triangular. ‘They 
about equal in diameter the internal filament. 

Fig. 2, pl. 5, represents a small cluster of youngish filaments of this species. 


M. sejunctum, Woop, (sp. nov.) 

M. thallo cespitulo, molle, parasitico; trichomatibus simplicibus, plerumque inarticulatis, sed, 
interdum breve, interdum longe, articulatis, continuis, rarius interruptis, apice attenuatis, 
flavo-olivaceis aut viridibus, sparse granulatis; vaginis plerumque amplis et distinctis, hya- 
linis, sepius valde undulatis, apice plerumque valde amplificatis et in fibrillas solutis ; cellulis 
perdurantibus diametro subequalibus ; sporis nullis. 

Diam.—Trichom ggg” = .00016"; cum vag. gygq” = .0005”. 

Hab.—In plantarum aquaticarum foliis, Carp River, Michigan. 

Thallus somewhat cespitose, soft, parasitic; filaments simple, mostly inarticulate, but some- 
times shortly sometimes long articulate, continuous or more rarely interrupted, attenuate at 
the apex, yellowish-olive or greenish, sparsely granulate; sheaths mostly ample and distinct 


hyaline, often strongly undulate, the apex mostly much amplified and dissolved into fibrille ; 
heterocysts about equal to the filament in diameter; spores wanting. 


Remarks.—This species was found in the Carp River bog, growing on the edges 
of minute leaves, so as to form little prominences or thickenings of the margin. 
The trichomata are quite distinct from one another, and can scarcely be said to be 
united into a frond, although they all appear to radiate from the base, where they 
are consolidated into a dense mass. The sheaths are generally quite distinct, much 
broader than the cytioplasm, and are not sensibly dilated below. In most speci- 
mens they are very distinctly alternately dilated and contracted, or in other words, 
undulated. This is especially the case when the sheaths are quite wide. Above, 
they are rapidly and widely dilated, are distinctly fibrillose, and appear to gradu- 
ally melt away. The cytioplasm is rarely articulated, and, when it is so, the joints 
are scarcely longer than broad, and are most generally confined to the distal end of 
the filament. The species appears to be most nearly allied to I Bauerianum, 
Grun., from which, however, it is quite distinct. 

Fig. 2a, pl. 4, represents this species magnified 250 diameters; fig. 2 6, a single 
filament magnified 800 diameters. 


M. elongatum, Woop. 


M. initio subglobosum, postea sepe nonnihil fusinum, nigro-viride, lubricum, firme ; trichoma- 
tibus erugineis, valde elongatis, flagelliformibus, interdum inarticulatis sed sepius breve 
articulatis, interdum ad genicula valde constrictis, apice interdum truncatis sed plerumque 
in pilum, longum, achroum, flexuosum, productis; vaginis achrois, arctis, sepe apice trun- 
catis; cellulis perdurantibus globosis vel subglobosis. 

Diam —rer0" = 00026.” 

Syn.—M. elongatum, Woon, Prodromus, Proc. Amer. Philos. Soc., 1869, p. 128. 


Hab.—In aquario. 


54 FRESH-WATER ALG& OF THE UNITED STATES. 


Thallus at first subglobose, afterwards frequently fusiform, blackish-green, slippery, firm; fila- 
ments #ruginous, very elongate, sometimes not articulated, but more generally shortly arti- 
culated, sometimes strongly contracted at the joints; apices sometimes truncate but generally 
produced into a long, flexuous, translucent hair; sheath transparent, close, frequently trun- 


cate at the apex; heterocysts globuse or subglobose. 


Remarks.—This species grew in my aquarium on some brook-moss, which I 
obtained from a spring above Manayunk. It forms little nodules of the size of a 
pin’s head upon the wire-like stems, or sometimes longer fusiform masses, which are 
apparently produced by the coalescence of a number of the little globes. The color 
of these fronds, which are very firm, is a blackish-green. The filaments radiate from 
the base in all directions, and at the apex are tipped with a very long hair-like flexu- 
ous point, or they are truncate, apparently from the breaking off of this terminal 
seta. The endochrome is not unfrequently interrupted within the sheath. When 
it is articulated, the joints are usually about as long as broad, and frequently are 
distinctly separated from one another. The sheath is sometimes quite apparent 
and distinctly truncate and open above, but in other instances is with difficulty 
perceived anywhere, and above is lost in the long hyaline point. At the points 
of attachment of the frond the filaments are so densely crowded as almost to 
appear to be coalescent, though I believe they are never really so; yet it is often 
almost impossible to separate them one from another by pressure on the glass cover, 
without entirely mashing and distorting the filaments. 

Fig. 1 a, pl. 5, represents a section of a frond of this species slightly magnified ; 
fig. 1 6, a single filament magnified 460 diameters. 


Genus MASTIGOTHRIX, Krz. 


Trichomata singula, plerumque sparsa, parasitica intra thalluam Chetophorarum aliarumque 
algarum, flagelliformia, in apicem piliformem achroum hyalinum cuspidata, distincte articulata, 
arcte vaginata, basi cellula perdurante instructa. (R.} 

Filament single, mostly scattered, parasitic within the thallus of Chetophora or other alge, 
flagelliform, with the apex produced in a. hyaline hair, distinctly vaginate, furnished with a basal 
heterocyst. 


Remarks.—I have simply copied the generic description of Prof. Rabenhorst, 
although it seems to me mare than doubtful whether the place of growth is any 
generic character whatever. I have relied more on the long hyaline apical hair, 
although our American form does grow in a gelatinous palmella like jelly. 


M. fibrosa, Woop. 
M. dilute vel cwruleo-viridis, vel olivaceo-viridis, vel sub-eruginea, infra haud articulata 
. . : . ? 
sursum spe breve articulata, apice in trichomata matura in setam hyalinam, distincte 
articulatam, longam, producta; vaginis achroois—in filamento immaturo, supra distinctis, 
latis, hyalinis, infra modice crassis, arctis,—in tvichomata matura infra arctis, indistinctis, 
supra in fibrillis dissolutis, apice absentibus; cellulis perdurantibus globosis, interdum 
geminis. 
Diam.—Trichone aeso 5 cell. perdur. ree00 —t3e00"- 
Syn.—M. fibrosa, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, p. 129. 
Hab.—Prope Philadelphia. 


FRESH-WATER ALGZ OF THE UNITED STATES. 55 


Light bluish-green, or olivaceous-green, apex in the mature filament -prolonged into a long, 
distinctly articulated hyaline seta; sheath transparent—in the immature filament distally, 
broad, and distinct although hyaline, below rather thick and close; in the mature filament 
below close, indistinct, above dissolved in fibrille and wanting at the apex; heterocysts 
globose, sometimes geminate. 


Remarks.—This plant was found growing with other low alge in a thick jelly, 
which clothed some wet, dripping rocks near Manayunk. In the young filaments 
the sheath is produced above into a broad, thick, gelatinous-looking portion, the 
cavity of which is often scarcely apparent. The cytioplasm in such filaments is 
mostly of a light bluish-green color, is granular and not very apparent. In older 
filaments, the trichoma above is prolonged into a long, curved hyaline point, and the 
sheath just below the base of this- is split into a number of fibrille. No spores 
were perceived. ‘The increase of the species appears to take place in the follow- 
ing manner: Near the middle of the filament a tumid swelling forms, in the 
centre of which appears after awhile a constriction, and this increases until at last 
there are shaped out the bases of two filaments. ‘Then the heterocysts appear, and 
finally the two halves of the original trichoma separate—each a perfect filament. 
(Fig. 3, pl. 5.) Sometimes, instead of a pair of filaments being thus formed, but 
a single base is shaped out at the place of swelling, and the original filaments split, 
as it were, thus giving origin to a second trichoma, which for awhile appears as a 
branch of the former, but is soon detached from it. In some specimens there are 
two heterocysts, unless the proximal of these, which is a light orange-clay color, 
represents a spore. 

Fig. 3, pl. 5, represents different forms of this species. 


Famity SCYTONEMACEA. 


Trichomata articulata, sepe moniliformia vel submoniliformia, vaginata, pseudoramosa, cellulis 
limataneis, ad pseudoramulorum basin, vel interstitialibus, pleramque pachydermaticis instructa. 
Vagine e stratis pluribus (etsi non semper distinctis) formite, superficie leves, corrugate vel 
exasperate, crustate, nonumquam stratis exterioribus in fibrillas discedentibus, haud raro passim 
intumescentes vel ocreate. 

Vegetatio non terminalis ; cellularum vegetativarum divisio ad unam directionem, initio in tricho- 
matibus medio, postea in utroque fine sepe alternans. Cellule limitanez ad utrumque polum locello 
lucido instructe. 

Propagatio gonidiis pleramque exultima generatione ortis. Gonidia plerumque numerosa seriata 
e vagina se exserunt tumque in singula secedunt. (R.) 


Filaments equal, articulate, often moniliform or submoniliform, vaginate, pseudoramose, furnished 
with heterocysts which are either interstitial or at the base of the branches, and are mostly thick- 
walled. Sheaths formed of numerous strata (not always distinct), their surface smooth, corrugate, 
or roughened, the exterior stratum sometimes breaking up into fibrille, not rarely intumescent or 
ochreate. 

Vegetation not terminal; division of the cells occurring in one direction, in the beginning in the 
middle of the trichoma, afterwards often alternately at each end. Heterocysts furnished with a trans- 
lucent spot at each end. 

Propagation mostly by gonidia arising from the last generation Gonidia mostly numerously 
seriate, passing out of the sheaths and then separating one from the other. 


56 FRESH-WATER ALGA&A OF THE UNITED STATES. 


Remarks.—The Scytonemacew are simple or branched filamentous plants, which 
grow in water, or in the air, upon tree-trunks, rocks, fences, &c., in moist localities. 
A number of individuals of one or more species are almost always associated to 
form on the ground little mats, or in the water attached or floating masses of vary- 
ing color and characters according to the species. ‘The individual filaments are 
composed of two distinct parts, the inner the protoplasmic matter, the outer the 
cellulose sheath. The former of these is a long cylindrical mass, which is occa- 
sionally interrupted by a distinct thick-walled cell, spoken of in this memoir as 
the heterocyst, or “cellulis perdurantibus.” The inner filament is composed of 
colored protoplasm, which is sometimes homogeneous, but in other cases is dis- 
tinctly granular. It is most generally articulated after the manner of an oscilla- 
toria, but occasionally it is continuous for a great portion of its length, and in one 
species, which is here described, although very possibly not belonging in the family, 
there are, at regular intervals, partitions running across from one side to the other of 
the sheath, so that the inner filament may be said to be made up of a number of cells. 

The heterocysts are of various shapes, globular, compressed, cylindrical, oblong, 
_ &c. &c. They are mostly provided with a bright colorless spot at each end. Their 
number varies according to the species. Sometimes they are single, in other cases 
there are several of them arranged in series. They are placed either at the origin 
of the branches, or are scattered apparently without definite arrangement in the 
length of the filament. In the one case, they are known as “ dasal,” in the other 
as “interstitial.” In any species, either of these methods, or both of them, may 
prevail; but a certain amount of specific value attaches to the situation of the 
heterocysts. Their function is totally unknown, although some have imagined 
them to have a sexual significance and even to be spermatozoids, but there is 
no proof whatever of the truth of such suppositions, and it is, I think, very certain 
that these heterocysts are not of the nature of spores. 

The sheath of the Scytonema is composed of one or more strata, which are 
often very distinct from one another, but are more often, perhaps, not so. It is 
opaque or translucent, aud has its outer surface smooth, or tubercular, fibrillate or 
roughened in some way. 

The specific characters in this family can best be commented upon under two 
heads—namely, those which are discoverable with the unaided eye, and those 
which the microscope alone can reveal. The points to be observed under the first 
of these are as follows: The place of growth of the plant, whether in the air or in 
the water, and, if it live in the air, to what it is attached—whether to stones, dead 
wood, or living trees, and it is possible that in some cases it may be found that 
certain species of Scytonema inhabit only certain species of trees. If the plant 
be in water, it must be noted whether it be attached or floating. Then the habit 
of growth must be looked at, including in this the size and thickness of the masses 
of filaments, whether they be flocculent, turfy, crustaceous, membranous-gelatinous, 
&c., their softness or rigidity, their color, as well as the arrangement in them of 
the filaments. ‘To discover the latter, it will generally be necessary to use a low 
power of the microscope, and at the same time the mode and profusion of branch- 
ing of the individual plant should be studied. 


FRESH-WATER ALG& OF THE UNITED STATES. 57 


The second class of characters are those discoverable only with the higher powers. 
They are divisible into two sets; those afforded by the inner filament and those 
derived from the sheaths. In the first of these the points to be noted are, the 
diameter of the filament; its color, whether it be or be not articulated, and if it 
be the length of the joints; whether it is uniform or moniliform; whether it be 
homogeneous or granulate; then the heterocysts should be examined as to their 
size, position, arrangement, shape, number, and color. 

The diameter of the sheath, its homogeneousness, its color, firmness, and the 
condition of its outer surface are to be included in the specific study. 


Genus SCYTONEMA. 


Trichomata ceespitoso-congregata vel fasciculata, plus minus pseudoramosa, cellulis interstitialibus 
instructa; vagine gelatinoso-membranacee, e stratis (interdum obsoletis) pluribus cylindraceis com- 
posite; cellulis perdurantibus singulis. 


Filaments cespitosely-congregate or fasciculate, more or less pseudoramose; furnished with in- 
terstitial cells; sheaths gelatinous-membranaceous, composed of many cylindrical, sometimes ob- 
solete, strata; heterocysts single. 


a. Terrestres vel aquatice. 


a. Terrestrial or aquatic. 


S. sim plice, Woop, (sp. nov.) 

S iu strato modice crasso, subtomentoso, nigro-viride ; trichomatibus valde elongatis, flexuoso- 
curvatis, parcissime pseudoramosis vel seepe sine pseudoramulis; pseudoramulis geminis vel 
singulis, plerumque elongatis ; trichomatibus internis modo distincte articulatis, modo inar- 
ticulatis, apice interdum brevissime articulatis, granulosis, pallide viridibus, ad genicula sepe 
nodosis vel disjunctis, articulis plerumque diametro equalibus ad 7 plo longioribus; vaginis 
plerumque supra truncatis et apertis, pellucidis, sepe coloris expertibus, interdum dilute 
aureo-brunneis; cellulis perdurantibus cylindricis, interjectis, diametro 2-5 plo longioribus. 


Diam.—Trich. cum vag. ge55/—te50" = -0004"—.00066"; sine vag. zeoq”—7e50" = 00013” 
—.00026” 


Hab.—In lignis irroratis, South Carolina. (Ravenel. ) 


S. in a moderately thick, somewhat tomentose, blackish-green stratum; trichomata very elongate, 
flexuously curved, very sparsely branched or frequently without branches ; branches geminate 
or single, mostly elongate; internal filament partly distinctly articulate, partly inarticulate, 
granular, pale-greenish, in its apex sometimesevery shortly articulate, sparsely granular, 
often nodose or disjoined at the joints; articles mostly from equal to to 7 times longer than 
the diameter; sheaths thick, transparent, often colorless, sometimes pale yellowish-brown, 
mostly open and truncate at apex; heterocysts cylindrical, interspersed, 2-5 times longer 
than their diameter. 


Remarks.—I am indebted to Professor Ravenel for specimens of this species. 
They are preserved in solution of acetate of alumina and accompanied by the fol- 
lowing label: “ Adhering to the wet sides of a wooden gutter, leading water from 
a spring, September 29, 1869: Aiken, South Carolina.” The filaments are 


remarkable for the fewness of their branches. Generally, indeed, there are no 
8 May, 1872. 


58 FRESH-WATER ALG OF THE UNITED STATES. 


branches whatever, and I have never seen more than a single pair, or, at most, 
three branches to a filament. The mass of filaments is blackish-green, somewhat 
tomentose and quite shiny in appearance. The articles are often very long, and 
the internal filament is frequently in such cases enlarged into a sort of globular 
node at the joint. Not at all rarely there is a very decided break in the endo- 
chrome at the joints. 

This species is very close to S. Austinit, from which, however, I think it suffi- 
ciently distinct. The points of difference are in the much firmer, much more 
colored and opaque, and rougher sheath of that species; in the swollen ends of 
the internal filament of S. Austinii, and its shorter articles, with the absence of 
nodes or distinct interruption of the endochrome at the joints. ‘The heterocysts 
are also quite different in the two forms, whilst the filaments of S. simplice are 
much the longer. 


S. Austinii, Woon, (sp. nov.) 

S. rupicola, strato tomentoso, cxspitoso, crasso, fusco-nigro; trichomatibus adscendentibus, 
curvatis, pleruamque simplicibus; trichomatibus internis erugineis vel fuscescentibus, articu- 
latis vel inarticulatis, fine seepe valde incrassatis; articulis diametro pleramque multo bre- 
vioribus, interdum longioribus; vaginis rubido- vel aureo-fuscescentibus, sepe sub-opacis, 
firmis, indistincte lamellosis, in apice plerumque achrois et coloris fere expertibus, superficie 
subrugosa et hirta; cellulis pedrurantibus breviter cylindricis, vel subquadratis vel subglo- 
bosis, interdum valde compressis et diametro multo brevioribus. 


Diam.—Fil. cum. vag. .0006”—.0008”; sine vag. .00016”—.0004”. 
Hab.—In rupibus, “ Little Falls, New Jersey.” (Austin.) 


S. growing on rocks, stratum tomentose, and somewhat turfy, brownish-black; trichomata 
ascending, mostly simple, curved ; internal filament eruginous or fuscous, articulate or inar- 
ticulate, often very much thickened at the ends; articles much shorter to longer than their 
diameter ; sheaths reddish or yellowish-fuscous, at the apex colorless and transparent, firm, 
indistinctly lamellate; surface rough; heterocysts shortly cylindrical, subquadrate or sub- 
globose, sometimes strongly compressed and much shorter than broad. 


Remarks.—This plant occurs as a blackish stratum of one or two lines in thick 
ness, forming a sort of miniature turfy cushion upon the rock. When examined 
with the hand-glass, this layer is seen to be composed of a great number of ascend- 
ing curved filaments whose color, in some specimens, is a reddish-brown; in 
others, apparently younger, yellowish-brown. Under the compound microscope 
the sheaths in the older filaments are seen to be much roughened externally and 
irregular in outline. The young sheaths are smooth. The filaments are mostly 
simple, since I have not seen more than a half dozen having even a single branch. 

The heterocysts are scattered at irregular intervals, and are remarkably irregular 
in form—sometimes much shorter than broad, sometimes several times as long. 
As the ends of the filaments are approached the internal filament suddenly swells 
out and increases sometimes to twice the diameter it has in the central part of the 
filament. In the filament proper it rarely attains a diameter of more than .0003”, 
and is commonly about .00025’’, whereas at the ends it very generally approaches 
the maximum .00042”, 


FRESH-WATER ALG& OF THE UNITED STATES. 59 


S. immersum, Woon, (sp. nov.) 

S. immersum cum algis alteris intermixtum et plantas aquaticas adherens; trichomatibus 
elongatis ; pseudoramulis plus minus distantibus, pleramque geminis, et e basi divergenter 
adscendentibus, brevibus aut elongatis; trichomatibus internis lete erugineis, interdum dis- 
tincte articulatis, interdum inarticulatis, apice obtuse rotundato, erugineo; articulis diametro 
subequalibus vel brevioribus; vaginis amplis, hyalinis, coloris expertibus; cellulis perdu- 
rantibus distinctis, singulis, interjectis, subcylindricis, diametro interdum fere duplo breviori- 
bus, interdum duplo longioribus. 


Diam.—Sin. vag. yySyq" = 000415". Cum vag. yx85q’” = .00075". 


Hab.—In aquis quietis, Cumberland County, New Jersey. 


S. immersed, intermixed with other alge and adhering to aquatic plants; filaments elongate ; 
branches mostly geminate, more or less distant, short or elongate; internal filaments bright 
eruginous, sometimes distinctly articulate, at others not sv, apex obtusely rounded eruginous ; 
joints about equal to the diameter or shorter; sheath ample hyaline, colorless; heterocysts 
distinct, single, interjected, subcylindrical, sometimes about half as long as broad, sometimes 
nearly twice as long. 


Remarks.—I found this plant in September, 1869, in Shepherd’s Mill Pond, near 
Greenwich, Cumberland County, New Jersey, forming, with other alge, a floccu- 
lent, greenish-black, slimy coating to the stems and finely dissected leaves of 
Ranunculus aquatilis. ‘The branches are very few in number in most specimens, 
and when they are more plentiful are apt to be short and abortive. ‘Their apices 
do not differ materially from their other portions. 

Fig. 9, pl. 2a, represents a portion of a filament of this specimen magnified 750 
diameters ; fig. 2 6 a whole filament magnified 260 diameters. 


S. Neegelii, Krz. (?) 

S. cesptoso-floccosum, bryophilum, nigro-viride; trichomatibus, plerumque sparse pseudora- 
mosis, pseudoramulisque elongatis et intricatis; trichomatibus internis breviter articulatis, szepe 
interruptis, sepe nonnihil moniliformibus, viridibus aut in etate provecta brunneis; articulis 
seepe sejunctis, diametro plerumque brevioribus, subtiliter granulatis; pseudoramulis plerumque 
singulis ; vaginis modice arctis, interdum subamplis, haud distincte lamellosis, modice crassis, 
hyalinis, coloris expertibus aut in etate provecta dilute fusco-brunneis; cellulis perduranti- 
bus nonnihil reniformibus, plerumque nullis, basilaribus. 


Diam.—Fil. cum vag. plerumque 755"—max. gyyy" 3 Sine vag. ygSqq", cell. perdurant. lab. 
tz$00"—long. reno". 

Syn.—S. Negelii (K1z.), RABENHORST, Flora Europ. Algarum, Sect. II. p. 252. 

Hab.—In fonte, prope Belvidere, Centre County, Pennsylvania. 


Growing in small, blackish-green woolly mats attached to mosses; filaments mostly sparsely 
branched, with the branches elongate and intricate; internal filament shortly articulate, 
often somewhat muniliform, often interrupted, green, or, in mature state, brownish; joints 
often disjoined, mostly shorter than the diameter, finely granulate; branches mostly single; 
sheaths moderately close, sometimes ample, not distinctly lamellate, rather thick, hyaline, 
colorless, or, in old age, light fuscous brown; heterocysts mostly wanting. 


Remarks.—I found this plant in the large spring that supplies Bellefonte with 
water, growing attached to mosses, so as to form little dark-green mats around 


60 FRESH-WATER ALG OF THE UNITED STATES. 


their stems and branches. These mats never exceeded an inch in length in any 
specimens that came under my notice. The filaments themselves are apparently 
not much branched and are densely interwoven. The sheaths are close, rather 
thick, not lamellate, of uniform diameter, except in that they are occasionally 
locally swollen, and are truncate and open at the end. ‘The internal filaments are 
frequently much interrupted, and in the younger plants are of adeep green. The 
joints are in many instances much separated, and in most cases very distinct. 
The filaments. indeed show a remarkable tendency to break up at the joints, so as 
to form a series of dish-like gonidia, so that the articles, or endochrome masses, 
may be generally described as strongly compressed spheres. In all the specimens 
that I have examined, I have seen but a single heterocyst. This was at the base 
of a branch, was somewhat reniform, and about three-fifths as long as broad. I 
have referred this species, doubtfully, to S. Naegelii, Ktz., the only account of 
which that I have met with, or know of, is a brief diagnosis in Rabenhorst’s Flora, 
in which many of the essential characters are omitted. 
Fig. 6, pl. 8, represents a portion of a filament of this species. 


S. thermale, K7z. 

S. strato tenue, nigrescente; trichomatibus flexuoso-curvatis, intricatis, parce pseudoramosis, 
internis pallide erugineis, sepe coloris fere expertibus, passim interruptis, pleramque inar- 
ticulatis sed sepe indistincte et interdum distincte articulatis, granulosis ; articulis diametro 
brevioribus vel subequalibus; pseudoramulis plerumque brevibus, geminis, in diametro tri- 
chomatibus equalibus vel subequalibus et interdum usque ad medium conjunctis, basi coa- 
litis, sepe e basi divergentibus; vaginis crassis, indistincte lamellosis, -vel luteo-fuscis vel 
fuscis, sed passim fere coloris expertibus, plerumque vix pellucidulis, in ramulorum apice 
spe hyalinis et coloris fere expertibus; cellulis perdurantibus, subquadratis vel cylindricis, 
singulis, interjectis. 

Diam.—Tr. cum vag. ysS55’— e300" = -00042"—.00058; sine vag. gogq” = .000166"— 
ad00 = -00025, rs 


Syn.—S thermale, K1z., RABENHORST, Flora Europ. Algarum, Sect. II. p. 250. 
Hab.—In terra argillacea, South Carolina. (Ravenel.) 


Stratum thin, blackish; filaments flexuously curved, intricate, sparingly branched; internal 
filament pale-greenish, often almost colorless, here and there interrupted, mostly inarticulate, 
but often indistinctly and sometimes distinctly articulate, granular; joints shorter or about as 
long as broad; branches geminate, mostly short, equal or subequal to the filament in diameter, 
coalescent at the bases, rarely so even to their middle, mostly divergent from the base ; sheath 
thick, indistinctly lamellate, yellowish-fuscous, and scarcely semitransparent, but here and 
there nearly colorless and pellucid, generally so in the apices of the branches; heterocysts 
subquadrate or cylindrical, single, interspersed. 


Remarks.—I am indebted to Professor Ravenel for specimens of this species pre- 
served in solution of acetate of alumina. The label reads, “Damp surface of hard 
clay, Sept. 25, 1869.” The sheaths are quite thick and scarcely translucent, so that 
the color of the inner filament seen through them is that of themselves. Curiously 
enough, one of these dark sheaths will for a space lose its color and be very trans- 
parent, in such places and in the apices of the branches, the inner filament is often 
a decided pale-green ; at other times it is almost colorless. The end of the sheaths 
are mostly closed, but I have seen them open, with the inner filament project- 


FRESH-WATER ALG# OF THE UNITED STATES. 61 


ing. The branches are nearly always short, and divergent from their united bases. 
The heterocysts have frequently one of their ends rounded; and are quite 
numerous. ‘This species corresponds too closely to Rabenhorst’s description of 
Scytonema thermale to be separated, but it is possible a comparison of specimens 
might show decided differences —the description of the European form is not very 
full. ‘The American plants seem to approximate most closely the Var. intextum. 
I have seen a single branch given off only in one instance. 

Fig. 1, pl. 6, represents a filament of this species magnified 260 diameters; fig. 
1 6, the outline of a heterocyst magnified 750 diameters. 


S. Myochrous, Ac. 

S. strato tenui, pannoso-tomentoso, obscure fusco (nonnunquam subsericeo); trichomatibus 
validissimis, fuscis, lucidis, leniter curvatis, adscendentibus, internis erugineis, apice (articul. 
term. 5-6) rubellis, distincte articulatis; pseudoramulis plerumque geminis, seepe longissimis 
flaccido-erectis, trichomate dimidio circiter tenuoribus; trichomatis vaginis crassis, distincte 
lamellosis, firmis, pulchre luteo-fuscis, superficie levissimis, ramulorum semper pallidioribus 
(luteis, rarius achrois), apice sepe achrois, clausis et obtuso-rotundatis; cellulis perdu- 
rantibus oblongis vel subcylindricis, achrois, trichomatis interni diametro subequalibus. 
(R.) Strato obscure olivaceo, trichomatibus parce pseudoramosis, ad #,’” crassis ; psendo- 
rannulis singulis, vaginis achrois vel luteolis; vag. trich. luteo-fuscis. (R.) Species mihi 
ignota. 


Diam.—Trichom 0.0011”—0.0014”; ramulorum ad 0.00068”. (R.) 


Syn.—S. Myochrous, AGARDH; Var. Contextum, CARMICHAEL. RABENHORST, Flora Europ. 
Algarum, Sect. II. p. 254. 


Hab.— Foot of Crow’s-nest,- West Point.” Bailey. Silliman’s Journal, N.S. vol. iii. 


Strato thin, pannosely tomentose, obscurely fuscous (sometimes somewhat silky) ; filaments very 
strong, fuscous, bright, slightly curved, ascending ; the internal eruginous, distinctly articu- 
late with the apex (terminal 5-6 joints) reddish; branches mostly geminate, often very long, 
flaccidly erect, about one-half thinner than the filament; sheath of the filament thick, dis- 
tinctly lamellate, firm, beautifully yellowish-fuscous, surface very smooth; sheath of the 
branches always paler (luteous or rarely colorless) with the apex colorless, short and obtusely 
rounded ; heterocysts about equal in diameter to the internal filament. Stratum obscurely 
olivaceous, filaments sparsely branched, about ,’" thick; branches single, with the sheaths 
transparent or yellowish ; sheath of the trichoma luteo-fuscous. 


S. calotrichoides. Kurztna(?). 

8. cespitosum, mucosum, plerumque cum algis variis intermixtum; trichomatibus plus minus 
curvatis; pseudoramulis plerumque geminis, varie curvatis, simplicibus, elongatis; tricho- 
matibus internis modo distincte articulatis, modo inarticulatis, interdum moniliformibus, 
luteo-viridibus vel erugineis, granulosis; articulis plerumque diametro brevioribus sed in- 
terdum permulto longioribus, haud rare vel subglobosis vel valde compressis; cellulis per- 
durantibus singulis, subcylindricis; vaginis plerumque pellucidulis, distincte lamellosis, in 
trichomatibus plerumque rubido-vel luteo. brunneis sed interdum coloris expertibus, in pseu- 
doramulis hyalinis, coloris expertibus vel dilutissime luteis vel dilute luteo-brunneis. 


Diam.—Cum vag. max. zz'55”=.00075"; plerumque z75p" =.00045"; sine vag. ze55° — aoa’ 
pseudoram. gqg5” = .0005”. 
' Syn.—S. calotrichoides, Kz. TRABENHORST, Flora Europ. Algarum, Sect. IT. p. 252. 


Hab.—South Carolina. (Ravenel.) 


62 FRESH-WATER ALG& OF THE UNITED STATES. 


Cespitose, mucous, mostly intermixed with various alge; filaments more or less curved ; 
branches mostly in pairs, elongate, simple, variously curved; internal filament partly dis- 
tinctly articulate, partly not articulate, sometimes moniliform, yellowish-green or emginous, 
granular; joints mostly shorter than the diameter, sometimes much longer, pOMstINES sub- 
globose or strongly compressed; heterocysts single, subcylindrical ; sheaths distinctly lamel- 
late, mostly reddish or yellowish-brown, but sometimes colorless, in branches hyaline, color- 
less, or with a very faint yellowish tint, or sometimes brownish. 


Remarks.—The specimens, from which the above description was drawn up, 
were sent me by Professor Ravenel from South Carolina. The extremities of the 
sheaths are either closed, or open. ‘The branches are almost always in pairs, and 
sometimes three or four are given off together, but this is not common. They 
are often nearly or quite colorless; the main filament is generally a sort of 
brown—sometimes quite bright from the predominance of the yellow hue. 
Although my specimens do not precisely agree with the descriptions of the 
European S. calotrichoides, yet the disagreement does not seem sufficient or 
sufficiently constant to separate specifically the two forms; the most important of 
the differences is in the coloration of the sheaths and heterocysts, which in the 
American plant are commonly, but not universally, respectively brownish and 
greenish. , 

The label, which Professor Ravenel has attached to some of the specimens, 
reads, “In wet, boggy places, on rotten pine boards, Sept. 25, 1869.” 

Fig. 2, pl. 6, represents a filament of this plant magnified 250 diameters. 


S. cataracta, Woop. 

S. rupicola, cespitosum, fusco-atrum, longe et late expansum; trichomatibus flexuosis, flexili- 
bus, fere 0.25” longibus, vage pseudoramosissimis, superficie levibus; pseudoramis elongatis, 
singulis, rarissime geminis, liberis, interdum fuscis, sepius hyalinis, apice plerumque truncatis 
et rare nonnihil attenuatis et seepe barbais sed haud rubellis; trichomatibus internis erugi- 
neis, tenuissimis, plerumque distincte articulatis; articulis diametro plerumque brevioribus, 
sed interdum longioribus, sepe sejunctis, seepe subglobosis ; vaginis crassis et firmis; cellulis 
perdurantibus et basilaribus et interjectis, singulis, rarissime geminis. 


Diam.—Trich. cum vag. plerumque.00045”; max. .0011”; sine vag. max. .00013”. 

Syn.—S. cataracta, Woop, Prodromus, Proc: Am. Phil. Soc., p. 129, 1869. 

Hab.—In flumine Niagara prope cataractam. 

8. forming on rocks an extended turf-like stratum of a brownish-black color ; filaments flexuous, 
flexible, almost 0.25” long, irregularly branched, their surface smooth; branches elongate, 
single, rarely in pairs, free, sometimes fuscous, frequently hyaline, their apices generally 
truncate, rarely somewhat attenuate, frequently provided with enlargements, never reddish ; 
cytioplasm eruginous, very thin, generally distinctly articulate; articles mostly shorter than 


broad, but sometimes longer, frequently disjoined, often subglobose; sheaths thick and firm; 
heterocysts both basal and interjected, single, extremely rarely geminate. 


Remarks.—This species grows abundantly in the Niagara River, on the rocks 
below the great cataract. It is really in little tufts, but these are in many cases 
placed so closely as to form a broad turf-like coating to the stones. Often, however, 
the tufts are in smaller patches, and are of sufficient length to wave with the 
eddies and currents in the water. The branches are almost always given off 


FRESH-WATER ALG# OF THE UNITED STATES. 63 


singly since I have examined some hundreds of specimens, and have only in one 
instance detected them in pairs. ‘The apices of the branches, and indeed of 
the main filaments, are beautifully colorless and hyaline, and not unfrequently a 
branch will have this hyaline sheath for a long distance. ‘The extreme ends are 
mostly truncate and open, and, often near them, the sheaths will have marked 
swellings ; a condition which, for want of a better term, I have spoken of as being 
barbate. Sometimes near the end of the filament the diameter of the sheath will 
be suddenly lessened. ‘The large cells are both interstitial and placed at the bases 
of the branches; they are more or less oblong or quadrangular, sometimes being 
scarcely longer than broad, but in other cases several times longer. At their posi- 
tion there is very generally a sort of globular enlargement of the filament. The 
sheath is sometimes very obscurely lamellate. The color of the older filaments is 
a dark, almost chocolate-brown. This is apparently the species referred to by 
Professor Bailey as being Scytonema ocellatum of Harvey, in Silliman’s Journal, vol. 
il. N. S., although that plant, according to Professor Rabenhorst, belongs to the 
genus Sirosiphon. 

Fig. 1 a, pl. 7, represents a portion of a filament, magnified 280 diameters; fig. 
1 6, a whole filament slightly magnified. 


S. dubium, Woop (sp. nov.) 

S. immersum, in floccis mucoso-tomentosis olivaceo-nigris plantas aquaticas adherens, vel in 
strato mucoso et nonnihil tomentoso dispositum; trichomatibus valde elongatis et arcte in- 
tricatis, varie curvatis, plerumque sparse pseudoramosis; pseudoramulis plerumque singulis, 
et plus minus distantibus et modice brevibus, vel interdum brevissimis et abortivis et nonnihil 
confertis; trichomatibus internis seepe in pseudocellulis distinctis contentis, interdum con- 
tinuis et indistincte articulatis vel inarticulatis, plerumque dilute ceruleo-viridibus sed inter- 
dum lete erugineis, subtiliter granulatis; vaginis arctis plerumque modice crassis et firmis, 
hyalinis, coloris expertibus; cellulis perdurantibus cylindricis, diametro 2-6 plo longioribus. 


Diam.—Cum vag. ps35q'—raba7" = -00025"—. 0004”. 


Hab.—In aquis quietis, Cumberland County, New Jersey. 


Immersed, adhering to water plants in olive-black tomentose flocculent masses, or arranged 
in a mucous and somewhat tomentose stratum ; trichomata very long and closely interwoven, 
variously curved, mostly sparsely branched; branches generally single, more or less distant, 
and moderately short, sometimes very short, abortive, and somewhat crowded ; internal fila- 
ment often contained in distinct cell-like apartments, sometimes continuous and indistinctly 
articulate, or not at all articulate, finely granulate, mostly a pale bluish-green, sometimes a 
bright eruginous color; sheath close, mostly rather thick and firm, hyaline colorless; hetero- 
cysts cylindrical, 2-6 times longer than broad. 


Remarks.—I found this plant, September, 1869, in Shepherd’s Mill Pond, near 
Greenwich, Cumberland County, New Jersey. It formed dark, ugly, somewhat 
slimy, tomentose flocculi adhering to, and binding together, the finely-dissected 
leaves of Ranunculus aquatilis. The filaments are very long, slender, and sparsely 
branched.. The branches are given off at right angles, or nearly so, but are fre- 
quently sharply bent. just above their origin. They are often, but not always, 
rather short. The most remarkable character that the plant possesses is that in 
many filaments there are very distinct regular partitions stretching across from 


64 FRESH-WATER ALGA OF THE UNITED STATES, 


side to side, so that the interior is divided, as it were, into successive cell-like 
chambers, in which the colored protoplasm is contained. This character seems 
almost to separate the plant from the genus Scytonema, but I have deemed it 
insufficient grounds for indicating a new genus, Since writing the preceding 
remarks, I have received specimens of this species from Professor Ravenel, who 
collected them in South Carolina, near the town of Aiken. They agree in all 
respects, except that they form a dark, mucous, somewhat tomentose coating to 
pieces of wood. 

Fig. 3 a represents the outline of a series of the cells alluded to, magnified 750 
diameters, and figs. 34 and 3c, portions of filaments magnified 460 diameters. 


b. Arboricole. 
b. Growing on trees. 


S. cortex, Wooo. 

S. minutissimum, stratum tenue submembranaceum formante; trichomatibus sparse pseudoramu- 
losis, pseudoramulisque repentibus et plus minus concretis, viridibus aut dilute fuscis, varie 
curvatis, haud rigidis; cytioplasmate viride, articulato, rare distincte granuloso; articulis 
diametro longioribus aut brevioribus; vaginis arctis, nonnibil.tenuibus, plerumque coloris 
expertibus, sed interdum dilute fuscis; cellulis perdurantibus et singulis et geminis, et basa- 
libus et interjectis, globosis vel subglobosis. 

Diam.—tTrich. cum vag. 7255"—7e50" 

Syn.—Scytonema cortex, Woop, Prodromus, Proc. Am. Philos. Soc., 1869, p. 180. 

Hab.—South Carolina. 

S. very minute, forming a thin, submembranaceous stratum ; filaments sparsely branched, toge- 
ther with the branches, creeping and more or less concreted together by their sides, green or 
light brown, variously curved, not rigid; cytioplasm (internal filament) articulate, rarely 
distinctly granulate; joints longer or shorter than broad; sheaths close, rather thin, trans- 
parent, generally colorless but sometimes light brown; heterocysts globular or subglobular, 
single or in pairs, basal or otherwise. 


Remarks.—I have specimens of this species collected in South Carolina by Pro- 
fessor Ravenel, who found it growing on the bark of Platanus occidentalis. The 
thin, almost membranous stratum which it forms, is of a dark olive-black, and has 
to the eye a sort of minutely warty appearance. The filaments are so involved 
and so adherent, one to the other, that I have not been able to separate any length 
of them, nor are the branches distinguishable from the main filaments. The sheaths 
are rather thin, and often not very apparent. 

Fig. 4, pl. 6, represents this species. 


S. Ravenelii, Woop. 

S. lignicola, breve cespitosum, Viride-nigrum; trichomatibus plerumque repentibus, vel fusco- 
olivaceis vel aureo-fuscis, modice pseudoramosis; ramis ascendentibus, rigidis, flexuosis rare 
pseudoramulosis, vel fusco-olivaceis vel aureo-fuscis, rarissime cum apicibus subachrois; tri- 
chomatibus internis coloris expertibus, granulosis, sepe vagina erumpentibus, plerumque 
articulatis; articulis diametro longioribus aut brevioribus; vaginis arctis, crassibus, fusco- 
olivaceis vel aureo-fuscis, plerumque supra truncatis et apertis, superficie nonnunquam irregu- 
laribus; cellulis perdurantibus subquadratis vel subglobosis singulis aut rare geminis, inter- 
jectis; in stato juvene trichomatibus internis erugineis, vaginis tenuibus. 


7 i 9 6", * . 
Pacino cum vag. 7550 —7B00 3 TAM cum vag. 7Ayq”—zs55”; trich. sine Vag. sain” 
— 2.0005. 


FRESH-WATER ALG#Z OF THE UNITED STATES. 65 


Syn.—S. Ravenelit, Woop, Prodromus, Proc. Am. Philos. Soc., 1869, p. 180. 
Hab.—tIn cortice, South Carolina. 


8. Forming little turfy spots of a greenish color, on bark; filaments mostly creeping, either 
brownish-olive or yellowish-brown, moderately branched; branches ascending, rigid, flexu- 
ous, very rarely provided with secondary branchlets, either brownish-olive or yellowish- 
brown, rarely subtransparent at the apex; cytioplasm colorless, granular, often extending out 
beyond the sheaths, generally articulate; joints longer or shorter than broad; sheaths close, 
thick, brownish-olive or yellowish-brown, for the most part truncate at their ends and open, 
their surface sometimes irregular; heterocysts subquadrate, single, interstitial. 


Remarks.—I am indebted to Prof. H. W. Ravenel for specimens of this very 
distinct species. Some of these are labelled as having grown on the twigs of a 
celtis in South Carolina, other specimens are on the bark of a willow. The branches, 
which are mostly shortish, simple, and variously curved, are sent up in great 
numbers by the creeping stems, and, like the stems themselves, are mostly free, 
but not unfrequently are closely adherent by their edges. 

The internal trichoma or cytioplasm, owing to the great thickness of the sheaths, 
is not very apparent within these latter, but not unfrequently projects for a dis- 
tance beyond them, when it is seen to be colorless, very granular, and mostly, but 
not always, distinctly articulated. In the young plant the filaments are bright- 
green, often not more than ,;4,, of an inch in thickness, and have the sheath very 
thin, or may be almost imperceptible. It affords me great pleasure to dedicate 
this species to Professor Ravenel, not as an acknowledgment merely of his aid in 
my studies of this hitherto neglected branch of the North American Flora, but 
rather of the great services he has rendered science in some of its kindred 
branches. 

Fig. 4, pl. 5, represents the end of a filament of this species magnified some 450 
diameters. 


Genus TOLYPOTHRIX, Krz. 


Trichoma scytonemacea cum cellulis perdurantibus seriatis. 


Filament similar to that of scytonema, but with the heterocysts seriate. 


T. distorta, (MttiEx) Kovrz. 

T. cxespitoso-floccosa, lete et pulchre viridis; trichomatibus intertextis, lete viridibus, modo 
distincte articulatis modo inarticulatis; articulis diametro brevioribus seepe aut sub-nullis 
aut nullis; pseudoramulis singulis; vaginis arctis, homogeneis, vitreis ; cellulis perdurantibus 
basilaribus et interdum interjectis, pachydermaticis, plerumque in parallelogramme enormis 
forma, plerumque 4-seriatis, subachrois, interdum sparsissime granulatis. 


Diam.—y3'59"—s0'o0 « 
Syn.—T. distorta, (MtuuER) Krz. Raxpenuorst, Flora Europ., Algarum, Sect. IT. p. 275. 


Hab.—In aquario, Philadelphia, Wood. Rhode Island (Olney} Thwaites. Warden’s Pond, 
Rhode Island; Reservoir Pond, West Point; Fourth Lake, Madison, Wisconsin, Bailey. 


Flocculent cspitose, bright, beautiful green; filaments interwoven, bright green, partly dis- 
tinctly articulate, partly continuous ; articles shorter than long, often very indistinct, some- 
times absent; branches single; sheaths close, homogeneous, glassy; heterocysts basilar, 
9 May, 1872. : 


66 FRESH-WATER ALG OF THE UNITED STATES. 


sometimes interspersed, thick-walled, mostly irregularly parallelogrammatic, mostly 4-seriate, 
semitransparent, sometimes very sparsely granulate. 


4 


Remarks.—This species grew spontaneously in the aquarium of my friend Dr. | 
Frické, to whom I am indebted for specimens of it, forming little, bright-green 
balls adherent to the various aquatic plants. It approaches so very closely the 
European 7. distorta, that I have considered it as a mere variety of it, although it 
differs in having the heterocysts mostly arranged in fours, and also apparently in 
their shape—they being in our plant mostly parallelogrammatic. 

Fig. 1 a, pl. 8, represents a section of heterocysts magnified 800 diameters; fig. 
1 6, a portion of filament magnified 800 diameters. 


Genus PETALONEMA, Berk. (1833.) 


Scytonematis trichomata vaginis crassissimis e stratis numerossissimis brevioribus, infundibuli- 
formi dilatatis, imbricatis et plerumque dilutissime coloratis compositis. (R.) 


Syn.—Arthrosiphon, Krz. (1845.) 


“Filaments stratified, decumbent, free, simple, or branched. Tube or sheath very wide, flat- 
tened, longitudinally and transvetsely striate and crenulate at the edge; endochrome oliva- 
ceous annulated, here and there interrupted by a heterocyst. Brauches issuing in pairs, 
formed by the division and protrusion of the endochrome of the original filament. 

“When placed under the microscope the filaments present the appearance of a cylindrical cen- 
tral column, containing annulated, olive-colored endochrome, and a wide wing-like border at 
each side of the column, This border or sheath is obliquely striate, the stris running in an 
arch from the margin toward the centre, where they become parallel, and are then continued 
longitudinally downward along the medullary column, till lost in the density. The margin 
of the wing is closely crenulate and in age transversely striate at the crenatures as though 
jointed. Such is the apparent structure; the real structure seems to be, that an annu- 
lated central filament is inclosed within a number of compressed, trumpet-mouthed gelatino- 
membranaceous tubular sheaths, one arising within the other, and successively developed as 
the growth proceeds. These sheaths, thus concentrically arranged, are indicated by arching 
longitudinal striae; and the mouths of the younger sheaths, projecting slightly beyond those 
of the older, form the crenatures of the margin.” Harvey. 


P. alatum, Bers. 

A. pulvinato-crustaceus, rupicola, varie coloratus; trichomatibus internis erugineis, curvatis, 
parce pseudoramosis, modo continuis, modo torulosis, submoniliformibus, apice plerumque 
paulum incrassatis, sepe roseolis, rotundatis; articulis distinctis, granulosis, diametro sub- 
equalibus vel paulo brevioribus; vaginis stratis internis, aureis vel aureo-fuscentibus 
externis achrois, vitreis; cellulis perdurantibus interjectis et ad pseudoramulorum asin: 
plerumque solitariis, subglobosis vel oblongis, dilute fuscis. (R.) Species mihi tgnota. 


Diam.—Trich. intern. 0.00016”—0.00032” ; vag. 0.00377". (R.) 


Syn.—Arthrosiphon alatus, (Grev.) Rasen. Flora Europ. Algarum, Sect. II. p. 265. 
Petalonema alatum, BERKELEY. Harvey, Nereis Boreis Americana, part iii. p. 99 
Smithsonian Contributions, 1846. 


Hab.—‘ On dripping rocks under Biddle Stairs, Niagara Falls.” (Harvey.) 


“This forms strata of a dark chestnut-brown color and of indefinite extent on the surface of 
rocks or soil exposed to the constant drip of water. The filaments are decumbent lying 
without order in the gelatinous matrix in which they are developed, and which Foose the 


FRESH-WATER ALG OF THE UNITED STATES. 67 


groundwork of the stratum. They appear to be unattached to the soil, and each filament 
may be about half an inch in length; but they are commouly found broken off at the inferior 
end, or the lower part decays whilst the upper continues to grow. They are slightly curved, 
in serpent-like fashion, never quite straight; at first they are simple, but now and then emit 
lateral branches, which issue at considerable angles and generally in pairs. When a filament 
is about to branch, a rupture takes place in the side of the sheath, and the endochrome issues 
in two portions, one connected with the upper, the other with the lower half of the filament; 
these form the nuclei or medullary portion of two new branches and become duly invested with 
@ membranous sheath, and gradually put on the aspect of the adult filament. The endo- 
chrome is granular, dark-brown, and annulated at short intervals, the transverse rings being 
placed very close together in the youngest portions, and less closely in the older, where they 
are distant from each other about twice the diameter of the column. This annulated endo- 
chrome is interrupted at certain fixed places, where an ellipsoidal cell is formed, separating 
the endochrome of the lower from that of the upper portions.” Harvey. 


Remarks.—I have never seen either the genus or species, and therefore am 
forced to copy the descriptions of both from Rabenhorst and Harvey. 


Fammty SIROSIPHONACE.A. 


Thallus ramosus, e cellulis pachydermaticis aut uni vel pluri seratis et in vagina ampla inclusis 
formatus, interdum cellulis perdurantibus instructus. Ramificatio vera fit cellularum vegetativarum 
quarundam divisione in axis longitudinalis directionem, qua ex re cellule duz sorori# gignuntur; 
cellula inferior in trichomatis continuitate permanet, superior divisione continua repetita in eandem 
directionem se ad ramum explicat. 

Propagatio adhuc ignota. i 


Frond branched, formed of thick-walled cells in an ample sheath, sometimes furnished with hete- 
rocysts. Cells uni- or multi-seriate. Branches formed by a longitudinal division of certain 
cells, so as to form two sister cells; the inferior of which remains as part of the trichoma, whilst 
the other, by repeated divisions, grows into a branch. 

Propagation not known. 


Remarks.—The Sirosiphonacee are the most complex in their organization of 
all the Phycochromophycec, in so far as the protoplasm within the sheaths is every- 
where broken up into a number of distinct cells, each of which is provided with 
a thick coat or wall as well as in the circumstance of the frond having more perfect 
branching. The so-called pseudo-branches in the other families are more truly 
comparable to distinct fronds or thalli remaining attached to the parent thallus 
than to distinct branches, whilst among the sirosiphons the branches really belong 
to the original thallus. The heterocysts are much more frequently absent than 
present, only one of the known American species being furnished with them. 
The sheaths are generally not so distinctly sheaths as among the oscillatoria, &c., 
for, instead of being distinct tubes, they appear rather in most cases as masses of 
firm jelly, the outer portion of which is hardened almost into a periderm, and in 
the inner part of which the cells are imbedded. Their color varies from the 
transparent colorlessness of glass to a dark opaque-brown. Their surface is per- 
haps most'frequently smooth, but at times is tuberculate or otherwise roughened. 
I have never seen anything like spores about them. 


63 FRESH-WATER ALGA OF THE UNITED STATES. 


These plants grow in the majority of cases in the air, in such situation as on 
the face of dripping rocks; on the trunks and branches of trees, on moist ground, 
&c.; but some of the species are found in the water, either attached or floating. 
They generally form little mats of indefinite extent, but occasionally the filaments 
are united more closely into an almost membranaceous stratum. 

The species are, I think, in most instances readily distinguished, the characters 
being partly discoverable with the unaided eye and partly microscopic. The 
points to be attended to in the first category are the size, color, form, and 
consistency of the mats of fronds, and the place of growth. In the second are 
included the general shape of the frond and its size and method of branching; 
the general shape, color, and size of the cells, the thickness of their walls and the 
method of their arrangement, both in the main thallus and the branches, also the 
form, &c., of the end cells of the branches; the heterocysts, their absence, or, if 
present, their frequency, size, shape, color, and position; the sheaths, their color 
and firmness, and the character of their surface. 


Genus SIROSIPHON, Krz. 


Trichomata torulosa, vaginata, plerumque ramossissima et aureo- vel olivaceo-fusca, e cellulis 
pachydermaticis 1-2-3 vel pluri-seriatis formata et cellulis interstitialibus (seepe nullis) subglobosis 
vel oblongis coloratis instructa. Vagina plerumque crassissima, firma, pulchre aureo-fusca, lutea 
vel olivacea, in apicem obtusum plus minus attenuata. 


Filament torulose, sheathed, mostly very much branched, yellowish, or olivaceous-fuscous, formed 
of thick-walled 1-2-3 or many seriate cells and furnished with interstitial cells (often wanting) 
which are globose or oblong and colored. Sheaths mostly very thick, firm, beautiful golden fus- 
cous, clay-colored or olivaceous, more or less attenuate at the obtuse apex. 


a. Cellula in trichomatibus plerumque in serie simplice vel duplici ordinata. 


a. Cells mostly arranged in a simple or double series in the filament. 


S. scytenematoides, Woop. 

8. strato submembranaceo, nigro-viride, sepe interrupto, cum superficie inequale; trichoma- 
tibus sepe arcte intricatis, flexuosis aut varie curvatis, haud rigidis, pleruamque vix ramosis; 
cellulis uniseriatis, interdum interruptis, arctis, irregulare quadrangulis, diametro subsequa- 
libus aut 1-3 plo brevioribus, haud distincte granulatis, cweruleo-viridibus; vaginis amplis, 
hand distincte lamellosis, superficie enormiter corrugatis et hirtis, plerumque coloris experti- 
bus sed interdum dilute brunneis. 


Diam.—Sine vag, max. 755” = .00066”; cum vag. max. 719,”= 0013”. 
Syn.—S. scytenematoides, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, p. 184. 
Hab.—South Carolina. (Ravenel.) 


S. In a submembranaceous, blackish-green, frequently interrupted stratum, with an uneven 
surface; filaments often closely intricate, flexuous or variously curved, not rigid, mostly 
sparsely branched ; cells uni-seriate, sometimes interrupted, close, irregularly quadrangular, 
about equal in length to their diameter, or about 1-3 times shorter, not distinctly granulate, 
bluish-green; sheaths ample, not distinctly lamellate, their surface rough and corrugate, 
transparent, mostly colorless, sometimes light-brown. 


Remarks.—This species was collected in South Carolina by Prof. Ravenel, who 
found it in the month of February growing on the limbs of Myrica cerifera. The © 


FRESH-WATER ALGA OF THE UNITED STATES. 69 


blackish-green layer, which it makes upon the bark is very peculiar, being almost 
membranaceous, and especially in the dried state, presenting a rough, somewhat 
warty surface. ‘The trichomata have the sheath more distinctly in the form of a 
hollow cylinder, or, in other words, more plainly a sheath, than any other species 
T have seen of the genus; the cells are also without any apparent walls, and are 
placed very closely together, so that the whole filament looks very like a scyto- 
nema, 7 
Fig. 1, pl. 9, represents a portion of a frond ‘magnified 260 diameters, 


S. pellucidulus, Woop. 

S. immersus; trichomatibus ramossissimis, solitariis vel subsolitariis; ramis plerumque unila- 
teralibus, ramulosis; ramulorum apicibus late rotundatis, haud attenuatis; cellulis in serie- 
bus simplicibus dispositis, in trichomatibus nonnihil rotundatis, in ramulis sepe angularibus, 
plerumque compressis, diametro equalibus—4 plo brevioribus; terminalibus cylindricis et 
obscure articulatis; cellulis interstitialibus nullis; vaginis arctis, hyalinis, haud lamellosis; 
cytioplasmate wrugineo vel brunneo, minute granulato. 

Diam.—Trich. cum vag. 7855” = .00106”; sine vag. = .0008”. 

Syn.—S. pellucidulus, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, p. 183. 

Hab.—In stagnis, prope Hibernia, Florida. (M. W. Canby.) 


S. immersed ; filaments very much branched, solitary or subsolitary ; branches mostly unilateral, 
branched; apices of the branches not attenuate, broadly rounded ; cells disposed in a simple 
series, in the trichoma somewhat rounded, in the branches frequently angular, mostly com- 
pressed, from equal to 4 times shorter than the diameter; terminal cell cylindrical, obscurely 
articulate ; interstitial cells none; sheath close, hyaline, not lamellate; cytioplasm srugin- 
ous or brown, minutely granulate. , 


Remarks.—This species was collected by Mr. William Canby in a little marsh 
pool near Hibernia, Florida. ‘The branches are given off in abundance, mostly in 
a unilateral manner, are often very long, and about equal in diameter to the main 
filament, and give origin to numerous branchlets. The sheaths are very trans- 
parent and very close. I have never seen them in any way lamellate or fibrous, 
or of any color. The cells do not have very apparent walls. In the main fila- 
ment and branches they are globose, or, more commonly, very much compressed, 
but in the newer branches, and sometimes in the older, they are very angular. 
The few cells near the end of the branches are so shaped as to remind one of the 
phalanges of the fingers. The last cell is cylindrical and has a number of cells 
indicated in it. The color of the young cells varies from a deep bluish-green 
to a ferruginous-brown—that of the older from a light bluish-green to ferruginous- 


brown. 
Fig. 2a, and 24, pl. 8, represent portions of filaments of this species. 


S. compactus, (Ac.) Krz. 

S. strato expanso, tomentoso, fusco-nigro; trichomatibus elongatis ramulisque adscendentibus, 
apice interdum paullum attenuatis sed sepe clavatis, obtusis ; trichomatibus internis e cellu- 
larum serie simplici formatis, et plerumque moniliformibus; cellulis diametro subequalibus 
vel brevioribus, subglobosis vel subquadratis, spe compressis ; cytioplasmate dilute ceruleo- 
viride, subtiliter granulatis; cellulis apicalibus cylindricis et oscillarium modo, seepe indistincte, 


710 FRESH-WATER ALG#& OF THE UNITED STATES. 


articulatis ; vaginis firmis, aureo- vel rubido-fuscis, in ramulis sepe subluteis, haud distincte 
lamellosis; cellulis perdurantibus plerumque modice numerosis, singulis, subglobosis, sepe 
valde compressis, dilute fuscentibus. 


Diam.—Plerumque y2,%5o"—12es0" = -0008"—.001"; max. goy5” = .0013"; cell. perdurant. 
Tz500° = .00058”. 
Syn.—Scytonema compactum, Acarpu. Syst. p. 38, N. 3. Harvey’s Manual, p. 154. 
Hassalia compacta, Hassau, Fresh-water Alge, p. 232, t. Ixviii. f. 3. 
Sirosiphon compactus, (Ac.) Krz. RaBennorst, Flora Algarum, Sect. II. p. 287. 
Hab.—In rupibus calcareis, New Jersey. (Austin.) Prope Salem, Mass. (Russel. ) 


Stratum expanded, tomentose, fuscous-black; filaments and branches ascending, with their 
obtuse ends sometimes slightly attenuate but often clavate; internal filaments composed of a 
single series of cells, mostly moniliform; cells shorter than or nearly as long as broad, 
subglobose or subquadrate, often compressed; apical cell cylindrical and articulate somewhat 
like an oscillatoria; cytioplasm light bluish-green, finely granulate; sheath firm, reddish or 
yellowish-brown, yellowish in the branches and near the ends; heterocysts mostly rather 


numerous, single, subglobose, brownish. 
¢ 


Remarks.—The specimens from which the above description was drawn up 
were received from Messrs. Austin and Russell, and have been considered as 
identical with the European 8S. compactus, although not in absolute agreement 
with the descriptions thereof. The most important of the differences are in the 
matter of size, the measurements given by Prof. Rabenhorst not equalling those 
attained to by the American plant. 

The differences, however, do not seem sufficient to separate the forms, and, 
in the absence of European specimens, the two have been considered one species, 
The sheaths in the older portions of the filaments are nearly opaque, but in the 
branches and younger portions they are quite translucent. The heterocysts some- 
times are truncate atone end. The internal cells are rarely arranged in a double 
series, such arrangement is, however, much more common in the specimens re- 
ceived from near Salem, than in those found in Northern New J ersey. Mr. Rus- 
sell’s specimens are labelled as growing on shaded and moist rocks in patches two 
or three inches wide. 

Fig. 3 a, pl. 8, represents the end of a filament of this magnified 150 diameters ; 
3b, a fragment magnified 250 diameters; 3c, a heterocyst magnified 860 dia- 
meters. 


S. Crameri, Briaa. 

8. cespitibus, tomentosis, spatiose expansis, fusco-nigris; trichomatibus vage ramosis; ramis 
plerumque singulis, sepe elongatis, spe clavatis; cellulis internig uniseriatis, diametro sub- 
zequalibus vel brevioribus, interdum subglobosis, sepe subquadratis, in etate provecta sepe 
e pressione mutua valde compressis et transverse oblongis, aureo-fulvis vel in state juvene 
interdum erugineis; cellulis terminalibus in massam subcylindricam coalescentibus; cellulis 
perdurantibus nullis; vaginis aureo-fuscis in state provecta plus minus subopacis et distincte 
lamellosis, in etate juvene plus minus pellucidis et seepe coloris expertibus. 


Diam —Trich. cum vag. max plerumque .002”; interdum 00225”; ram. .0015”—.0025” ; trich 
sine vag. .00083”. | 


Syn.—S. Crameri, Briiaa. Razennorst, Flora Kurop. Algar., Sect. II. p. 288. 


FRESH-WATER ALGA OF THE UNITED STATES. 71 


Hab.—In rupibus irroratis inter muscis minutis. Mount Tahawus (vulgo Mount Marcy)! alt. 
5000 feet. 


Forming a blackish, widely expanded, tomentose turfy covering to rocks; filament with scat- 
tered branches; branches mostly single, often elongate and clavate; cells uniseriate, about 
equal, or shorter than long, sometimes subglobose, often subquadrate ; in advanced age often 
strongly compressed and transversely oblong from mutual pressure, yellowish, or sometimes, 
when young, greenish ; the apical cells coalescent into an irregularly cylindrical mass ; hete- 
rocysts wanting ; sheaths yellowish-brown ; at maturity more or less subopaque, and distinctly 

: lamellate; in youth more or less transparent, and sometimes colorless 


femarks.—Near the top of Mount Tahawus, in the Adirondack Mountains, 
there is, at an altitude of about five thousand feet, a steep slope of bare rock, 
the bed of an old landslide, over portions of which water is continually drip- 
ping. In such places the plant under consideration flourishes, forming with 
some very minute mosses a blackish, turfy coating to the rock of many feet, 
or even yards, in extent. The specimens agree well with the descriptions of the 
European plant, which also grows at about the same altitude as the American. 
They have, however, one peculiarity not noted in description of the European 
form, namely, that oftentimes the sheath of a branch widens out until it is actually 
much larger than the main filament. The color of the cells in the European form 
is said to be eruginous; but I conceive this depends somewhat upon the age of 
the specimens and is scarcely of primary value.. The only other difference worth 
noticing is that my measurements exceed somewhat those given of the European 
plant. Ido not think, however, there is any good ground for separating the forms 
as distinct species. 

The finding of an Alpine plant growing on a mountain half way across the world 
from its first discovered home, at practically the same altitude, is a matter worth 
noting as a fact in Botanical Geography. 


S. neglectus, Woop. 

8. immersus; trichomatibus subsolitariis, longis usque ad lineas quatuor, cylindricis, ramossis- 
simis ; ramulis singulis; cytioplasmate interdum erugineo, plerumque aureo-brunneo; cellulis 
uniseriatis rarissime biseriatis, subglobosis, interdum sejunctis sed plerumque arcte connectis 
et moniliformibus, modo confluentibus, haud distincte pachydermaticis; cellulis terminalibus 
elongato-cylindricis, spe nonnihil oscilatorium modo articulatis; cellulis interstitialibus nullis ; 
vaginis interdum brunneis, plerumque coloris expertibus. 


Diam.—Trichom. cum vag. zg} =.0017"; sine vag. ogy” = -001”. 
Syn.—S. neglectus, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, p. 133. 
Hab.—In stagnis, New Jersey. 


S. immersed, subsolitary, attaining a length of 4 lines, cylindrical, very much branched ; branches 
single; cytioplasm eruginous, mostly yellowish-brown ; cells uniseriate, very rarely biseriate, 
subglobose, sometimes separate but more frequently closely united and moniliform; terminal 
cell an elongated cylinder, often articulate somewhat like an oscillatoria; interstitial cells 
wanting ; sheaths transparent, sometimes brown, mostly colorless. 


1 “ Tahawus,” cloud splitter. The Indian names of the American mountains ought to be retained, 
in spite of the fact that some vulgar land surveyor has defiled the Adirondacks with the names of 


politicians, through whose influence he hoped for patronage. 


72 FRESH-WATER ALGA OF THE UNITED STATES. 


Remarks.—This plant was found in a very stagnant pool, forming, with various 
other species of alge, a gelatinous, eruginous-brown stratum, through which the 
single plants were thickly scattered, without anywhere forming the major portion 
of the mass. The plants themselves are large enough to be distinguished by the 
unaided eye. Under the microscope the sheaths are seen to be exceedingly trans- 
parent and colorless, except in the older part of the filament, where they are often 
dark brown and opaque; but even in such case, the edges are translucent and 
lighter colored. 

The internal cells or globose masses rarely have distinct coats, and even when 
such were apparent, as in the older portions of the plants, there appeared to be a 
communication between the cells. ‘The original main stem is rather short, shorter 
often than numerous branches into which it breaks up. Very often the apices of 
the branches are colorless and entirely empty, consisting simply of sheath; often, 
however, they are occupied by a cylinder of protoplasm, which is sometimes arti- 
culated more or less distinctly like an oscillatoria. 

Fig. 4, pl. 8, represents a fragment of a filament with a small branch. 


S. lignicola, Woop. 
8. strato expanso, tomentoso, atro; trichomatibus ramossissimis, arcte intertextis; ramulis ab- 
breviatis vel elongatis, subrectis aut varie curvatis, apicibus obtuse rotundatis vel subacumi- 
natis ; trichomatum et ramulorum cellulis uni-vel biseriatis, rare in trichomatibus maturis mul- 
tiseriatis, pleruamque pachydermaticis, dilute vel saturate swrugineis, enormibus, plerumque 
homogeneis ; cellulis terminalibus in trichomatibus immaturis elongatis, cylindricis, sepius 
nonnihil oscillatorium modo articulatis, granulosis; vaginis sat amplis, haud achrois, vel 
luteo-brunneis vel fuscentibus vel ferrugineis. 


Diam.—Trich. cum vag. max. py” = .00066”. 
Syn.—S. lignicola, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, p. 133. 
Hab.—South Carolina. (Ravenel.) 


Occurring in an expanded, tomentose, black stratum; filaments very much branched, closely 
interwoven, branches abbreviate or elongate, nearly straight or variously curved, their apices 
obtusely rounded or subacuminate; cells 1-2 seriate, mostly thick-walled, light or deep 
wruginous, irregular, mostly homogeneous; terminal cells elongate, cylindrical, frequently 
articulate somewhat like an oscillatoria, granulate; sheaths somewhat ample, not transparent, 
light bright, fuscous or ferruginous. 


Remarks.—I have seen dried specimens only of this plant, which were collected 
by Prof. H. W. Ravenel, in South Carolina, It is said to grow on old boards, 
and appears to be a very distinct species. There are frequently two or three 
very short, stubby branches arising together. The apices of the filaments and 
branches are in some cases filled with endochrome to the end, and are broadly 
rounded at the apex. In other cases the sheath of the filament extends a distance 
beyond the endochrome, and is finally rapidly diminished to a point. The cells 
within the filaments are of various shapes, sometimes globular, sometimes quad- 
rangular, more often irregular. The original specimens from which this descrip- 
tion was written were collected in April. I do not know whether they grew 
immersed, or merely on boards exposed to the weather. I have since received 


FRESH-WATER ALG OF THE UNITED STATES. 13 


specimens collected in the month of August, which grew on boards over which 
spring water was constantly running. ‘These specimens agree perfectly with the 
others, except that the filaments are larger and the elongated apical cell is wanting; 
differences which I believe to be due to the specimens collected in August being 
older than those first received. 

Fig. 2 a and 2 6, pl. 9, were taken from the types, whilst fig. 2 ¢, pl. 9, from the 
August specimens. 


a. Cellule plerumque in serie duplict vel multiplict. 
a. Cells generally in double series, or multiple series. 


S. argillaceus, Woop, (sp. nov.) 


S. strato tenui, expanso, subnigro, submembranaceo; trichomatibus brevibus, dense intricatis 
et spe nonnihil concretis, ramosis, irregularibus; pseudoramulis brevibus, varie curvatis, 
nonnihil rigidis, plerumque ascendentibus, apice nonnihil attenuatis; cellulis subglobosis, 
sepe compressis, plerumque in serie simplici sed interdum in serie duplici, vel rare multiplici; 
cellulis apicalibus valde elongatis, cylindricis, scytoneme trichomatibus internis similibus; 
vaginis crassis, firmis, in trichomatibus maturis saturate rubido-brunneis, in ramulis sepe luteo- 
brunneis et in apice hyalinis et fere coloris expertibus; cellulis perdurantibus nullis. 


Diam.—ze%55" = .000833”. 
Hab.—In palude argillacea, South Carolina. (Ravenel.) 


Stratum thin, expanded, blackish, submembranaceous; filaments short, densely intricate, and 
‘frequently somewhat concreted, giving origin to numerous branches, irregular; branches short, 
variously curved, somewhat rigid, mostly ascending, apex somewhat attenuate; cells sub- 
globose, often compressed, mostly in simple series, sometimes in double, rarely even in multi- 
ple; apical cells elongate, cylindrical, resembling the inner filament of a scytonema; sheath 
thick, firm, in the mature filament deep reddish-brown, in the branches yellowish-brown, at the 
apices of the branches nearly colorless and transparent ; heterocysts absent. 


Remarks.—I am indebted to Prof. Ravenel for this plant, which was found by 
him on a moist clay bank near Aiken, South Carolina, August, 1869. It forms a 
thin, somewhat membranous, dark stratum, the filaments of’which -are so closely 
united that it is almost impossible to tease them apart with needles. Neighboring 
filaments are often united at the edges so as to form distinct bundles, and even 
the branches are sometimes concreted, although, generally, as seen under the 
microscope, they project from the mass in all directions. The surface of the fila- 
ments is mostly rough and ragged with fibrille and membranous projections. In 
the older filaments the cells are often entirely absent. They are mostly single, 
but sometimes multiple in the filaments; in the branches they are often partially 
double. The ends of the older branches are often broken and empty, whilst those 
of the younger are rounded. The color of the cells, as I have seen it, does not 
strikingly differ from that of the sheaths. 

Fig. 3 a, pl. 9, represents a portion of an old frond magnified 460 diameters, 
and fig. 3 }, the end of a younger branch. No. 79. Collection of Ravenel, Aug. 


1869. 


S. guttula, Woop. 
8. in maculis subnigris, parvis, tenuibus, plerumque rotundatis, interdum enormibus, dispositus; 
trichomatibus arcte intertextis, ramossissimis, rigidis, ineequalibus, subcylindricis, nonnihil 
10 May, 1872. 


14 FRESH-WATER ALG& OF THE UNITED STATES. 


contortis; ramulis abbreviatis vel nonnihil elongatis, apice obtuse rotundatis; ramulorum et 
trichomatum cellulis tri-multiseriatis, pleramque pachydermaticis, ferrugineo-fuscis, enormiter 
globosis, homogeneis; cellulis apicalibus interdum breve cylindricis, haud articulatis; vaginis 
sat amplis, luteo-brunneis vel dilute ferrugineo-brunneis. 

Diam.—Max. trich. cum vag. 735” =.0013". 

Syn.—S. guttula, Woov, Prodromus, Proc. Amer. Philos. Soc., 1869, p. 132. 

Hab.—South Carolina, in Taxodium distichum. (Prof. Ravenel.) 


Arranged in small, thin, black spots, which are generally round, but sometimes irregular: fila- 

- ments closely interwoven, very much branched, rigid, unequal, subcylindrical, somewhat con- 

torted; branches abbreviate or somewhat elongate, apex obtusely rounded; cells of the 

trichoma and branches 8 to many seriate, mostly with thick coats, ferruginous-fuscous, irregu- 

larly globose, homogeneous; apical cells sometimes shortly cylindrical, not articulate, sheaths 
ample, yellowish-brown. 


Remarks.—This species was found growing on the bark of Taxodiwm distichum, 
by Prof. H. W. Ravenel, in South Carolina, and by him given to Dr. Billings, 
U.S. A., to whom I am indebted for specimens. It forms on the bark minute 
roundish, blackish, dot-like spots of about a line in diameter, or sometimes, appa- 
rently, by the coalescence of two or more of these spots, larger irregular patches. 
The habit of the plant is a rigid‘one. The main stem is often irregular in size, 
variously bent and rebent, and mostly gives off a number of branches, which fre- 
quently nearly equal the main filament in size, and like it are bent in various 
directions. They also frequently give origin to numerous short branches. In 
some instances, there is a distinct apical cell, which is cylindrical, but only two or 
three times longer than broad; in many cases, however, this cylinder being want- 
ing, the ordinary cells extend to the extreme apex. 

Fig. 4 a, pl. 8, represents a filament, and fig. 4 6, the end of a branch magnified 
460 diameters. 


S. acervatus, Woop. 

8. in guttulis minutissimis, subcrustaceis, nigris, in strato subcontinuo sepe ageregatis; tricho- 
matibus parvis et brevibus, rigidis, admodum ineequalibus,. prostratis, tuberculis, arcte et dense 
ramossissimis, viridibus aut aureis aut brunneis ; ramulis brevibus, plerumque haud ramulosis, 
erectis aut ascendentibus, sepe abbreviatis et papilliformibus, obtusis, sepe lateraliter connatis ; 
cellularum serie in trichomatibus multiplici in ramulis plerumque simplici; cellulis subglobosis 
vel subangularibus, viridibus, haud distincte granulosis, in ramulorum apice seepe breve cylin- 
dricis et interdum obsolete articulatis ; vaginis aureis, nonnihil hyalinis. 


Diam.—Trich. max. 73§y"; ram. 725q’—7Hyy". 
Syn.—S. acervatus, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, p. 132. 
Hab.—South Carolina, in corttce (Ilex opaca). (Prof. H. W. Ravenel. ) 


Arranged in drops, which are very minute, subcrustaceous, black, and frequently aggregate into 
a subcontinuous stratum ; filaments small and short, prostrate, rigid, somewhat unequal, tuber- 
culate, densely and closely branched, green or golden or brown; branches short, for the most 
part not branched, erect or ascending, frequently abbreviate, and papilliform, obtuse; series of 
cell multiple in trichoma, mostly simple in the branches; cells snbloboss or subanedier 
green, not distinctly granulate, in the apices of the branches frequently shortly cylindrical ani] 
sometimes obsoletely articulate; sheaths golden, somewhat hyaline. 


FRESH-WATER ALGA OF THE UNITED STATES. 15 


Remarks.—This species was found in winter by Prof. H. W. Ravenel in South 
Carolina, growing upon the bark of Ilex o,.aca, forming minute, firm, crustaceous, 
roundish dots or masses, much smaller than a mustard-seed; but in some cases so 
closely aggregated as almost to make a continuous stratum. When one of these 
dots is placed under the microscope, the branches are seen presenting their ends 
upon all sides, reminding one of some varieties of coral, and between these are 
blackish matters, which prevent the whole dot from being seen. These branches 
are frequently placed very close to one another, and cohere by their edges so as to 
make a sort of membrane or a solid mass. The filaments themselves are mostly 
obscured in the dense mass of branches which clothe them. This species seems 
to be closely allied to S. coralloides, and I am not certain whether it is distinct or 
not. It is certainly very much smaller. 


S. pulvinatus, Brés. 

8. pulvinatus, humectatus, saturate olivaceo-niger, ad tres lineas crassus; trichomatibus crassis- 
simis, ramossissimis, fuscescentibus, enormiter curvatis; ramulis polymorphis pro state cras- 
sitie magnitudineque variis, apice plerumque obtuse rotundatis ; trichomatum cellularum serie 
multiplici, ramulorum 2-4 plici; vaginis crassis, luteo-fuscis ad saturate-fuscis, vel pellucidis 
vel non pellucidis, interdum rugoso-tuberculis. 

Diam.—Trich. cum. vag. max. .0042”. 

Syn.—S. pulvinatus, (BREB.) Razenuorst, Flora Europ. Algar., Sect. II. p. 290. 

Hab.—In rupibus prope Philadelphia, Wood. 


In moist, deep olive-black cushion-like masses of two or three lines thick ; filaments very thick, 
much branched, brownish, irregularly curved; branches polymorphous, varying in thickness 
and size, mostly with their apices obtuse; cells of the filament many seriate, of the branches 
two to four seriate; sheaths thick, yellowish-fuscous to deep fuscous, pellucid or opaque, 
sometimes rugose-tuberculate. 


Remarks.—I have received specimens of this species found by Mr. Austin in 
Northern New Jersey, growing on the exposed face of rocks. 

The size attained to exceeds that given by Mr. Rabenhorst for the European 
form. ‘The color of the cytioplasm varies from an almost verdigris-green to 
fuscous. 

Besides these specimens, Dr. I. Gibbons Hunt has given me fresh ones of a 
Sirosiphon which he found growing on the face of dripping rocks along the 
Wissahickon Creek, near this city. These are much smaller in every way than 
their more northern brethren, and differ in other respects, I think, sufficiently for 
a distinct variety. The filaments and branches are much flatter than in Mr. 


Austin’s specimens. I append a description. 


(Var. parvus.) 

S. trichomatibus in cespite saturate olivaceo-nigro arcte intertextis; trichomatibus crassissimis, 
enormiter ramosissimis, luteo-fuscescentibus, varie curvatis; ramulis polymorphis, apice 
plerumque obtuse rotundatis; trichomatum cellularum serie multiplici, ramulorum 1-4 plici; 
cytioplasmate granulato, plerumque saturate fuscescente, interdum lete viride ; vaginis crassis, 
dilute luteo fuscescentibus, interdum achrois. 


Diam.—Trichom. cum. vag. max. 53,” = .03” 


716 FRESH-WATER ALG OF THE UNITED STATES. 


Filaments closely interwoven into a deep olive-black turfy mass, very thick, irregularly and fre- 
quently branched, yellowish-fuscous, variously curved ; branches polymorphous, their apices 
mostly obtusely rounded; series of cell in filament multifold, in branches 1-4 fold; cytio- 
plasm granulate, mostly deep brown, sometimes bright green; sheaths thick, light yellowish- 
brown, sometimes transparent. 


Remarks.—The fronds are very irregular in form and size, much branched, and 
so closely interwoven that they mostly cannot be separated without breaking. 
The branches are sometimes short and stumpy, sometimes they are very long. 
The color of the cells approaches somewhat to a chocolate, at times with a little 
red in it so as to give something of a mahogany tint. ‘The walls of the cells are 
mostly very thick, but they are often lost in the general mass of the frond. In the 
branches, the cells are often so closely crowded as to almost obliterate their walls. 
In a few specimens I have found the cells to be of a bright green color, instead 
of that just mentioned. The exact meaning of this I do not know; it would 
scarcely seem to indicate immaturity, for I have found it in the oldest portion of 
large fronds, whose other parts were of the normal color. 

Fig. 1, pl. 10 represents a filament of this variety magnified 160 diameters. 


I have received from Prof. Ravenel certain dried alge, labelled Stigonema 
Ravenelli, BERKELEY, which appear to me to belong to this genus. In what place 
Berkeley described them, if ever, I do not know, nor why he placed them in the 
genus Stigonema. The following is a description of the species :— 


S. strato sub-nigro; trichomatibus arcte intertextis, ramossissimis, enormibus, varie curvatis ; 
ramulis brevibus et sublongis, varie curvatis, latis, apice nonnihil attenuatis et obtusis; tri- 
chomatum et ramulorum cellulis arctis, enormibus, in serie duo-multiplici enormiter dispositis ; 
cytio-plasmate bomogeneo, lete viride ; vaginis aureis, lucidis. 

Diam.—Max. trich. cum vag. 714y". 


When dried blackish ; filaments closely interwoven, very*much branched, irregular, and variously 
curved ; branches short or largish, variously curved, broad, their apices somewhat attenuated 
and obtuse; cells of the filament and its branches very close, irregular, irregularly arranged 
in a twofold or multiple series; endochrome homogeneous, bright green; sheath yellow, 
semitranslucent. 


Remarks.—This plant was collected by Prof. Ravenel on the now famous Look- 
out Mountain. It is of a thick, bushy habit, and appears to form turf-like mats 
of a line or two in thickness and of a blackish color. ‘The filaments throw off in 
all directions very numerous branches, some of which are short and stumpy, others 
quite long, and are themselves the parents of numerous secondary branches. The 
longer branches often rival the main filament in size, and like it vary continually, 
in being irregularly expanded and contracted. There is never a long, articulated 
cell, not even in the apices of the branches. The apices are often somewhat 
attenuated, and are always more or less obtuse. The cells are of a bright green 
color, are very irregular in form, and are often very irregularly arranged in rows 
of from two to five, both on the main filament and branches. The base of the 
filament often gives origin to several small, cylindrical, root-like processes, 


FRESH-WATER ALGA OF THE UNITED STATES. 17 


Fig. 4 a, pl. 9, represents a frond of this plant magnified 125 diameters; fig. 4 4, 
a fragment magnified 460 diameters. 


Professor Bailey, in American Journal of Sciences, vol. iii., new series, states 
that he has found two species of the genus Stigonema, namely, St. atrovirens, Ac. 
and St. mammillosum, AG.; the former growing on wet rocks at Indian Falls, 
Putnam County, New York; the latter at Round Pond, near West Point. I have 
no personal knowledge of the genus, but, according to authorities, it belongs to 
the lichens rather than the alge, apothecia having been detected in various 
species, 


Crass CHLOROPHYLLACEA 


Plantule aquatics vel aéres, uni-, bi-, vel multicellulares, aut singulee 
aut consociatee, familias formantes. 

Vegetatio terminalis vel non terminalis. 

Ramificatio aut nulla aut vera, sed cellularum non divisione, potius 
prolificatione. , 

Cytioderma non siliceum, combustibile, sepius e stratis successivis 
compositum, substantiam gelatinosam plerumque liquidam exsudans. 

Cytioplasma chlorophyllosum, chlorophylli loco nonnunquam erythrino 
vel substantia oleosa coccinea, carnea aut rufescente coloratum, nucleo 
(centrali vel laterali) plerumque preeditum, granulis amylaceis rarissime 
carens. 

Multiplicatio fit cellularum divisione vegetativa. Foecundatio ple- 
rumque sexualis. 

Propagatio fit aut oosporis vel zygosporis aut gonidiis tranquillis vel 
agilibus. 


Aquatic or aerial uni-, bi-, or multicellular plants occurring singly, or 
consociated in families. 

Vegetation terminal or not so. 

Branches either wanting, or if present, true branches, although formed 
rather by a process of proliferation than division of the cells. 

Cytioderm not siliceous, combustible, often composed of successive 
strata. 

Cytioplasm chlorophyllous, sometimes colored by an oily crimson, flesh- 
colored or yellowish-red substance, in the place of the chlorophyl, gene- 
rally furnished with a nucleus (either lateral or central), very rarely 
without starch granules. Growth occurring by the division of the cells. 
Fecundation generally sexual. 

Propagation taking place by oospores or zygospores, or by tranquil or 
motile gonidias. 


1 The description of this Class and Order is that of Prof. Rabenhorst. 


18 FRESH-WATER ALG OF THE UNITED STATES. 


Orpen Coccophycez. 


Alge unicellulares, Cellule aut-singule (plerumque perfecte segregate) aut plures in familias 
consociate, tegumentis involute vel nude, aut ramificatione aut vegetatione terminali destitute. 
Propagatio fit aut cellularum divisione aut zoogonidiis. 


Unicellular alge. Cells either single (mostly entirely segregate), or mostly consociated in fami- 
lies, walled or clothed with teguments, destitute of branches or terminal vegetation. Propagation 
by means of zoospores, or by the division of the cells. 


Famity PALMELLACEA. 


Alge unicellulares sensu latiori. Cellule aut singule aut numerose, familias constituentes, in 
muco matricali plus minus firmo, stratum gelatinosum amorphum, sepius figuratum, tubulosum 
(Hormospora) varie divisum et perforatum (Tetraspora), quasi ramificatum (Hydrurus) formante 
nidulantes, vel nullo (Rhaphidium, Dactylococcus). Cytioderma plerumque teiue, sepius tegumento 
gelatinoso aut homogeneo aut lamelloso preditum. Cytioplasma homogeneum, etate provecta ple- 
rumque distincte granulosum, viride, aut rubescens aut fuscescens, vesicula chlorophyllosa semper 
instructum (excepto Rhaphidio). 

Multiplicatio fit cellularum divisione vegetativa, propagatio gonidiis ex ultima cellularum gene- 
ratione transitoria cytioplasmatis divisione varia ortis. Gonidia tegumentis liberata, polo autico ciliis 
vulgo binis plerumque instructa et alacriter circumvagantia. -(R.) 


Alge unicellular in a broad sense. Cells either single or numerous, constituting families, imbedded 
in a jelly to form a gelatinous stratum which is amorphous or shaped, as tubular (Hormospora), 
variously divided and perforate (Tetraspora), falsely branched (Hydrurus), or sometimes is wanting 
(Rhaphidium, Dactylococcus). Cytioderm mostly thin, often furnished with a gelatinous or homo- 
geneous or lamellate tegument. Cytioplasm homogeneous, mostly at maturity distinctly granular, 
green-reddish or fuscous, always furnished with a chlorophyllous vesicle (except Rhaphidium). 

Multiplication taking place by a vegetative division of the cells, propagation by transitory gonidia 
arising by various divisions of the protoplasm from the last vegetative generation. Gonidia with- 
out integument, mostly furnished with two cilia at the anterior end, and moving about actively. 


Genus PLEUROCOCCUS, Meneu. (RABENE.) 


Cellule globose vel e mutua pressione angulose, plerumque nucleo instructe, tum singule tum 
in familias consociate. Cytioderma firmum, spe crassum, leve, hyalinum; cytioplasma homoge- 
neum viride vel oleosum rubrum. Multiplicatio cellularum vegetativarum divisione in directionem 
ad omnes dimensiones alternantem. Propagatio fit gonidiis intra sporangia ortis. 


Cells globose or angular from mutual pressure, mostly furnished with a nucleus, sometimes single, 
sometimes aggregated into families. Cytioderm firm, often thick, smooth, hyaline; cytioplasm 
homogeneous-green or oleaginous-red. Multiplication occurring by a vegetative division of the 
cells alternately in three directions. Propagation by means of gonidia, formed within sporangia. 


P. seriatus, Woop, (sp. nov.) 

P. corticolus, strata pulverula, rubido-brunnea, nonnibil crustacea formans; cellulis enormiter 
subglobosis, vel ovalibus, lete aurantiacis, interdum viride tinctis, haud distincte nucleatis, in 
seriebus singulis rectis vel curvatis conjunctis; tegumentis crassis, hand lamellosis, coloris 
expertibus. 

Diam.—zé55"'—7 250" = .00053”—.001 Q". 

Hab.—In palude. New Jersey. (Austin.) 


Growing on bark,. forming a reddish-brown, somewhat crustaceous powdery mass; cells irregu- 
larly subglobose, or oval, bright orange, sometimes tinged with green, not evidently nucleated, 
conjoined in single straight or curved series; tegument thick, lamellate, or not so, colorless. 


FRESH-WATER ALG#Z OF THE UNITED STATES. 19 


Remarks.—I am indebted to Mr. Austin for specimens of this little plant, which 
he found growing in a swamp near Closter, Northem New Jersey, on a young 
pin oak. It forms a sort of crustaceous powder, with little aggregations here and 
there, of a dull reddish-brown color. When these little masses are broken up, 
they are found to be composed of little series of very closely joined cells, generally 
a half dozen to a dozen in the row. I believe that at certain states of their growth 
these cells are green, as many of them have a very decided green tint on their 
edges, and I have seen one or two of them quite green. 

Fig. 2, pl. 10, represents this species magnified 460 diameters. 


P. pulvereus, Woon, (sp. nov.) 


P. cellulis minimis, ceruleo-viridibus, enormiter subglobosis, vel angulosis, in familias nume- 
Tosas consociatis; familiis e cellulis numerossissimis et dense confertis compositis, irregu- 
laribus, interdum confluentibus, plerumque pseudotegumentis hyalinis involutis, in strato 
pulvereo lete viridi aggregatis. 


Diam.—gz3 55" —s2250" = .00004"—.00013". 


Hab.—In fonte. ‘“ Boiling Springs,” prope Bellefonte, Pennsylvania. 


+ 


Cells very small, bluish-green, irregularly subglobose, oval, or angular, associated in numerous 
families ; families composed of very numerous and densely crowded cells, irregular, sometimes 
confluent, mostly surrounded by a false hyaline tegument, aggregated into a bright green 
pulverulent stratum. 


Remarks.—In Centre County, Pennsylvania, two miles “from Bellefonte, there is 
a very large and beautiful limestone spring, which is a favorite roadside watering 
place, and is laid down on the maps as “ Boiling Springs.” Forming a stratum 
over most of the bottom of this spring is the little plant here described. The 
stratum is in places nearly an inch in thickness, and when lifted by the hand is - 
found to be dry and crumbly, instead of mucous and tenacious. Under the micro- 
scope it is seen to be composed of vast numbers of irregular masses or families of 
cells imbedded in a firm jelly, which projects so as to form a sort of transparent 
coat to the whole mass; this cast I have spoken of in the description as a false 
tegument. The cells themselves are exceedingly small and furnished with an 
excentric point, which is probably a nucleus. 


Genus PALMELLA. 


Cellule globose vel ovales vel oblong, tegumentis plus minus crassis in mucum gelatinosum, 
sepius mox confluentibus involute, thallum difforme efficientes. Cellularum divisio directione in 
omnes dimensiones alternante. 

Cells globose, oval, or oblong, surrounded with a more or less thick integument generally very 
soon confluent into a firm or soft jelly. Thallus shapeless. Division of the cells alternately in all 
directions. 


P. Jesenii, Woop. 

P. thallo indefinite expanso, initio dilute aut lete viride, molle, pellucidulo; setate provecta 
firmo, tuberculoso, saturate olivaceo-viride; cellulis globosis vel ellipticis,—in thalli state 
immaturo, plerumque singulis aut geminis, sepe distantibus,—in etate provecta seepe in fami- 
lias connexis, pleramque confertis; tegumentis in thalli etate immaturo plerumque diffluenti- 
bus, etate provecta plerumque distinctis. 


80 FRESH-WATER ALG OF THE UNITED STATES. 


Diam.—Cell. glob. max. s;455” = -00028"; cell. oblong. long. max. ggg” = 0004”. 
Syn.—P. Jesenii, Woop, Prodromus, Proc. Am. Philos. Soc., 1869, p. 134. 


Hab.—In rupibus irroratis, prope Philadelphia. 


Thallus indefinitely expanded, in the beginning soft and pellucid, afterwards firm, tubercular, 
deep olive-green ; cells globose or elliptical; in the immature thallus, single or geminate, fre- 
quently scattered; in the mature thallus often closely conjoined into families, mostly crowded ; 
in the young thallus the teguments of the cells are mostly diffluent, afterwards distinct. 


Remarks.—This little plant was found along the banks of the Schuylkill River, 
just above Flat Rock tunnel, near Manayunk, forming in the early winter a gela- 
tinous mass of two to three lines in thickness, irregularly and.interruptedly spread 
over the face of wet, dripping rocks. In what appeared to be the younger por- 
tions, the jelly was often quite soft and almost colorless, and had the cells scat- 
tered rather sparsely and distantly through it. ‘The cells were but partially filled 
with chlorophyl, the vacuole left containing often numerous granules, and had 
distinct walls, being, as it were, merely immersed in the general maternal jelly. 
In the older fronds the texture is more firm, the color a deep green, and the bright 
green cells are mostly surrounded by a thick, very distinct tegument. ‘They are 
also largely arranged in little families of two, four, or even eight cells, surrounded 
by a common integument. ‘The oldest fronds are of a deep olive, almost blackish 
color, markedly tuberculate upon their upper surface and very firm in texture. 
They are surrounded by very distinct, firm, dark brown coats (a simple coat often 
involving two or more cells), and arranged in groups or families. As shown by 
the microscope in the superficial portion of such fronds, the jelly is of a yellowish- 
fuscous color, and the cells are themselves of a dark brown tint. The number of 
cells in the individual families varies from two to a dozen or more. Even in these 
old, firm fronds, the interior portions are frequently composed of greenish cells, 
without any distinct teguments or coat. In such cases the cells are mostly oblong 
or elliptical, and very much crowded together. This species appears to come 
closest to P. Brébissonii, Ktz., from which it differs, however, in its habit of 
growth and the size of its cells, 

Fig. 3a, pl. 10, represents a fragment of the upper surface of an old frond 
magnified 750 diameters; fig. 36, when taken from the inner jelly of similar 
fronds. 


P. dura, Woop, (sp. nov.) 
P. thallo enormiter subgloboso, enormiter minute lobato vel verrucoso, ceruleo-nigro, nonnihil 
crustaceo, minuto; cellulis arctissime confertis, plerumque enormiter oblongis, seepe in serie- 


bus irregulare dispositis, ceruleo-viridibus vel luteo-brunneis; tegumentis haud distinctis ; 
sporis globosis vel ovalibus. 


Diam.—Cell. reso =>, 00008" —zJ55” = .0001 6” 5 Spor. rxs00" =, 00058" —7 855" =.0008" 
Hab.—In fonte prope Philadelphia. 


Thallus irregularly subglobose, irregularly minutely lobate or warty, bluish-black, somewhat 
crustaceous, minute; cells densely crowded, mostly irregularly oblong, often arranged irre- 


gularly in series, bluish-green or yellowish-brown ; coats not apparent; spores globose or 
oval. 


FRESH-WATER ALG OF THE UNITED STATES. 81 


Remarks,—I found this plant growing in the large spring at Spring Mills in 
March or April, The fronds were in the form of little blackish balls attached to 
the stems of mosses in the water. They varied in size from the minutest speck, 
scarcely visible to the naked eye, up to ten lines in diameter; they are globose, 
very firm and hard, and the larger look almost as if they were aggregations of 
smaller ones. They are gregarious. The spores are mostly borne on the edges 
of the frond, sometimes they appear to be imbedded in its substance. At first 
they are of an intense bluish-green, but afterwards they appear to be yellowish- 
brown. None of the cells, as I have seen them, have their contents granulate. 

Fig. 5a, pl. 10, represents a section of a frond magnified 460 diameters; fig. 
5 6, a section of the edge of an old frond, developing spores. 


P. hyalina, Lyvas. 


“Fronds from a quarter of an inch to an inch in diameter, somewhat globose, but at length fre- 
quently more or less elongated into an ovate or even cylindrical form. Substance gelatinous 
and very tender, of a pellucid, watery appearance. Granules numerous, globose, green. 
The fronds are produced at first on rocks and stones at the bottom of streams, and afterwards 
become disengaged and float on the surface.” 


Remarks.—Professor Bailey states that he has found this species from Rhode 
Island to Wisconsin. Whether it is identical with the P. hyalina of Brébisson, or 
not, I cannot say. 


_ Genus PAGEROGALA,! Woon. 


Thallus solidus, gelatinosus, indefinitus, exalbidus, nonnihil pellucidulus, nodulis dense ageregatis 
et spe confluentibus formatus. Cellule globose, conferte, in familias consociate. Familie tegu- 
mentis tenuibus et membranaceis involute, in nodulorum centro posite. 


Thallus solid, indefinite, gelatinous, whitish, somewhat pellucid, composed of closely aggregated 
nodules which are often indistinct. Cells globose, crowded in families. Families surrounded by a 
thin membranaceous coat and placed in the centre of the gelatinous nodule. 


Remarks.—This curious plant was found by myself floating as indefinite masses 
of milk-white jelly on a mountain spring near Bear Meadow, Centre County, Penn- 
sylvania. The largest.of these gelatinous masses was six inches long. On taking 
them out of the water they were seen to be composed of somewhat irregular 
nodules, which in some portions of the mass were very distinct one from the other, 
but in other parts were confluent into an almost uniform jelly. When the nodules 
were separated it was discovered that each contained a membranous very delicate 
sack of a pale green color, which the microscope showed to be really a cell family. 
Their interior was hollow, or at least only partially filled with a transparent fluid, 
and they contained all round their exterior portion a layer of round, closely placed 
cells. In some instances the outer membrane was ruptured, and the sac only con- 
tained a few cells, which could often be seen to be moving freely in the inner 
liquid. The sac membrane is thin and delicate, colorless, and marked with curious, 
regular wrinkles or folds. In those portions of the common gelatinous mass, where 
the nodules were lost, I could not find any of these sacs. 


1 Tayepos, frozen; yaaa, milk. 
11 May, 1872. 


82 FRESH-WATER ALG OF THE UNITED STATES. 


No opportunity was afforded to study the development of this plant; but there 
can be but little doubt that the globular, thickish-walled cells are finally dis: 
charged by a rupture of the membrane and escape from the softening jelly into the 
water, each to be a possible starting point for a new frond. 

I have given this curious plant the name of Pagerogala, from its milky white- 
ness. Floating in the water it offered so close a resemblance to the spawn of frogs, 
though more opaque, that my companion, a most excellent naturalist, insisted, 
until its true nature was absolutely demonstrated, that I was simply wasting my 
time collecting the spawn of an amphibian. 


P. stellio, (sp. nov.) 
Diam.—Frond 3 inch; cells s455’—sg/0"- 


Genus TETRASPORA, Link. 


Thallus gelatinosus, membranaceus vel submembranaceus, initio saccato-clausus, etate provectiori 
vel postea explanatus. Cellule globose (vel anguloso-rotundate) plus minus distantes sed in familias 
magnas unistratas consociate ; tegumentis crassis in mucum homogeneum cito diffluentibus. Cel- 
lularum divisio in planitiei duas directiones alternans. 

Propagatio fit gonidiis mobilibus. 

Thallus gelatinous, membranous or submembranous, in the beginning a short sack, afterward 
expanded. Cells globose, or angularly so, more or less distant but consociated in a single stratum 
into large families. Tegument thick, very rapidly diffluent into a homogeneous mucus. Division 
occurring in two directions in the one plane. 

Propagation by means of zoospores. 


T. lubrica ? (Ror) Aa. 

T. thallo gelatinoso-membranaceo, lubrico, dilutissime viride, tubulogo sed seepe postea explanato, 
simplice vel ramoso, undulato-sinuoso, sepe lacunis munerosis perforato; cellulis globosis 
vel ellipticis, lete viridibus, interdum singulis sed plerumque quaternis vel geminis, locello 
achroo hyalino parietali sepe preeditis; cytiodermate tenuissimo, haud distincte visibile. 


Diam.—Cell. sg55"—azdy0" = 0.00025"—0.0005". 


Syn.—T perforata, Harvey. Batey, Silliman’s Journal, N. 8. vol. iii. 
f. lubrica, (Rorn) Ag. Rasenuorst, Flora Europ. Algarum, Sect, III. p. 41. 


Hab.—Northern Atlantic States. 


Thallus gelatinoso-membranaceous, slippery, very dilute green, tubular, but often finally ex- 
panded, simple or branched, undulately-sinuate, often perforated with numerous holes; cells 
globose or elliptical, bright green, sometimes single but mostly in pairs or fours, furnished 
with a parietal transparent hyaline space; cytioderm very thin, not distinctly visible. 


Remarks.—This little plant is very common around this city, growing usually 
in limpid, quiet water, such as springs, little rushy pools, and clean ditches, The 
frond is a translucent, light green or scarcely greenish, very slippery jelly, with 
the edges often very markedly undulate. It is very rarely simple, but on the con- 
trary is often very much and very irregularly branched, frequently indeed consist- 
ing of several broad portions united by narrow necks. It is an irregular sack, 
generally profusely perforate, and often with large imperfect portions. I think it 
finally in many instances becomes expanded and open. It is sometimes found 
lying on the bottom, but more frequently floats on the surface of the water. The 
breadth of the frond varies from two or three lines to an inch. The length often 
reaches several inches. The cells are mostly globular; but, immediately after 


FRESH-WATER ALG OF THE UNITED STATES. 83 


division, they are elliptical. They are of a bright green color and almost always 
have a conspicuous rounded granule within them; sometimes, but not commonly, at 
one end there is a hyaline space or vesicle, similar to that seen in zoospores. I 
have watched the production of zoospores in a plant gathered late in November. 
The outer wall of the cell is always so thin as to be scarcely perceptible, and when 
the zoospore is beginning to move, it looks as though the whole cell were rocking, 
the thin outer coating being lost to sight. After a considerable period of vain 
effort the zoospore escapes from the thick gelatinous mass which surrounds it. It 
is biciliated, roundish, and furnished with a hyaline space at the end. 

I have observed a Tetraspora growing in rapidly running water, which some 
would no doubt consider distinct, but which seems to me rather a variety. ‘he 
saccate frond was of a very vivid green, erect, buoyed up by an air-bubble con- 
tained in its upper end. Its shape was that of a long sack widened very much 
above, and below constricted into a fine point, by which it was firmly attached. 
In some instances it attained a length of seven or eight inches. In all other 
respects these plants agreed with the others found in quiet water. 

The species of this genus are to me not at all well-defined in any work which I 
have had access to. The plant now under consideration abounds everywhere in 
this neighborhood, and is without doubt the one identified by Prof. Bailey as 7. 
gelatinosa (Vauch), of which, however, he afterwards states that Prof. Harvey, to 
whom he had sent specimens, writes that it is a distinct species, and proposes to 
call it perforata. In my Prodromus I referred the plant to 7. lubrica (Roth). 
My reasons for doing this were that the size of the cells corresponds very closely 
with the measurements of that species as given by Prof. Rabenhorst, and the 
absence of anything that seemed to me definite in the descriptions of the two 
species. Moreover, if the possession of a parietal hyaline spot be not simply an 
accident of growth, it would indicate that the plant belongs to P. lubrica. I do 
not think, however, that any importance is to be attached to this, as the vacuole 
is often absent, and, although Prof. Rabenhorst makes no mention of it, is, in all 
probability, present in certain states or stages of T. gelatinosa. My own convic- 
tion is, at present, that 7. gelatinosa and T. lubrica are very probably synonyms. 
If they be distinct, the plant from which the above description was taken is refer- 
rible to T. perforata (Harvey), which, if not new, is a form of 7. lubrica rather 
than 7. gelatinosa, If T. lubrica and T. gelatinosa be united, no grounds are left 
for sustaining the separateness of T. perforata. 

Whilst botanizing in a primeval glade and forest, known as Bear Meadows, in 
this State, I came across a spring, covered with a Tetraspora, which appears to 
represent the 7. gelatinosa type. It formed great masses half an inch in thickness, 
at first attached, afterwards floating and covering the surface of the pool for several 
feet each way. When young these masses were elongated and were formed of 
numerous lobes attached often by very slender pedicles, and having their margins 
thickened and undulated so as to give a beautiful waved appearance to the light 
green mass. Under the microscope the structure was similar to that of the other 
form, except that the cells varied more and attained a greater size. ‘Their diame- 
ters ranged from g7!55” = 0.00027" to 73455” = 000066". 


84. FRESH-WATER ALG& OF THE UNITED STATES, 


I have also received from Prof. Ravenel specimens of a Tetraspora, which may 
be the young of a variety of this species, but which is very possibly distinct. If 
the specimens are adult, it certainly is. They consist of numerous little fronds not 
more than a third of an inch in length, often composed of several subcylindrical 
arms, as it were, radiating from a central portion, and attaining a length of a third 
of an inch or so. ‘These fronds are irregularly perforate, and are composed of 
cells agreeing perfectly in form, size, and arrangement with the more ordinary 
forms of 7. lubrica. 


TT. bullosa, (Rots) Ac. 

T. thallo membranaceo-saccato, obovato, sinuoso-bulloso, unciam usque palmam longo, postea 
explanato, dilacerato, saturate viridi, plus minus verrucoso; cellulis subsphericis (post divi- 
sionem factam hemisphericis vel angulosis) geminis vel quateruis, confertis, granulosis. 
(R.) Species mihi ignota. 

Diam.—Cell. ante divis. 0.00032”—0.00049” ; post divis. 0.00022”—0.00029”. (R.) 

Syn.—T. bullosa, (RorH) Ac. Rapennorsr, Flora Europ. Algarum, Sect. III. p. 39. 


Hab.— Salem, North Carolina. Schweinitz, Newburgh, New York.” Bailey, Silliman’s 
Journal, New Series, vol. iti. 


Thallus membranaceous saccate, obovate, sinuosely-bullose, from one to six inches in length, 
afterwards expanded, torn, deep green, more or less verrucose; cells subspherical (after divi- 
sion hemispherical or angular) in twos or fours, crowded, granular. 


Genus DICTYOSPHRIUM, Nace. 


Thallus gelatinosus plus minus liquidus, libere natans, seepe quasi nullus. Cellule vesicula chlo- 
rophyllosa unica et locello achroo parietali predite, tegumentis crassis in gelatinam homogeneam 
confluentibus involute, filis propriis subtilibus dichotome divisis, e familiarum centro ad peripheriam 
radiantibus connexe. Cellularum divisio ad omnes directiones. 

Propagatio fit gonidiis mobilibus 

Thallus gelatinous, more or less liquid, swimming free, often almost wanting. Cells furnished 
with a single chlorophyllous vesicle and a lateral transparent spot, surrounded with. thick coats, 
which are confluent into a homogeneous jelly and united by very fine filaments, which are dichoto- 


mously divided and.radiate from the centre to the peripheral families, Division of the cells occur- 
ring in all directions. 
Propagation by motile gonidia. 


D. pulchelluma, Woop, (sp. nov.) 


D. thallo subgloboso vel subovale, interdum subnullo, interdum indistincte lobato; cellulis 
globosis plerumque sparsis sed interdum nonnihil confertis. 


Diam.—Cell. gog5” = 0.00025"; thalle plerumque giy” = 0.0033"; interdum 135” = 0.0054.” 
Hab.—In stagnis prope Philadelphia. 


Thallus subglobose or suboval, sometimes indistinctly lobate, sometimes almost wanting; cells 
globose, mostly scattered, but sometimes rather crowded. 


Remarks,—I found this little plant, one August day, floating, in company with 
Closterium acerosum, in a brick-pond below the city. The little fronds are mostly 
roundish, or longer than broad, with a distinct outline, sometimes, however, the con- 
stituent jelly seems to fade into the surrounding water. There is never a distinct: 


FRESH-WATER ALG OF THE UNITED STATES. 85 


outer coat. The lateral transparent spot in the cells is mostly very evident, some- 
times it is wanting, however. Occasionally there is a very distinct blackish “ eye 
spot.” The threads which join the cells are very delicate, and I have never been 
able to absolutely demonstrate their meeting in the centre of the frond, although 
I believe they do so. In mounted specimens, even when preserved in carbolic 
acid water, they disappear after a time. I have never seen zoospores or any other 
reproductive bodies. 


Genus RHAPHIDIUM, Krz, 


Cellule fusiformes vel cylindracee, utrinque (plerumque) sensim sensimque cuspidate vel acumi- 
nate, rarius obtusate, recte vel varie curvate, singule, gemine vel fasciculatim aggregate, medio 
decussatim vel radiatim conjuncte, rarius bine sub polis lateraliter connexw, ceterum libere. 
Cytioderma tenue, leve. Cytioplasma viride, subtiliter granulosum, locello pallidiori vel achroo, 
centrali, rarius laterali, preditum. Cellularum divisio ad unam directionem. (R.) 


Cells fusiform or cylindrical, generally very gradually cuspidate or acuminate at the ends, rarely 
obtuse, straight or variously curved, single, geminate, or fasciculately aggregate, decussate in the 
centre or radiately conjoined, rarely two laterally united at the end, other cells free. COytioderm 
thin, smooth. Cytioplasm green, very finely granular, furnished with a central or rarely lateral 
transparent vacuole. Division of the cells occurring only in one direction. 


R. polymorphum, FResen. 


R. cellulis rectis vel varie curvatis, singulis, vel 2-4~8-16 fasciculatim collocatis, gracilibus, 
sepe gracillimis, nonnunquam medio paullum turgidis, subventricosis, nonnunquam paullum 
constrictis, apices versis, sensim attenuatis, acutissimis. 


Diam.—z 355" =.0001 3 
Syn.—B. polymorphum, FREsSEN., RABENHORST, Flora Europ. Algarum, Sect. ITI. p. 44. 
Hab.—Prope Philadelphia, Wood. 


Cells straight or variously curved, single or 2—4-8-16 fasciculately joined together, slender, 
often exceedingly so; sometimes slightly turgid in the centre, subventricose, sometimes 
slightly constricted; the apices gradually attenuate, very acute. 


Var. falcatum. 

Cellulis fusiformibus, gracillibus, utroque fine acutissime cuspidatis, curvatis vel semilunaribus, 
4-16 fasciculatim congregatis. 

Syn.—Ankistrodesmus falcatus. (CorDA.) RaBEnnorst, Flora Europ. Algarum, Sect. III. 
p. 45. 

Hab.—South Carolina, Georgia, Florida, Rhode Island. (Bailey.) 

Cells fusiform, slender, at each end very acutely cuspidate, curved or semilunar, 4-16 fascicu- 
lately congregate . 


Remark.—Fig. 3, pl. 7, represents different forms of 2. polymorphum. 


Famity PROTOCOCCACEA. 


Alge unicellulares sensu strictissimo, chlorophyllose, et vegetatione terminali et ramificatione 
vera carentes, sine cellularum generatione vegetativa. Vivunt aut singule, segregate aut in fami- 
lias consociate. Harum familiarum cellule numero aut indefinite semper se augentes (tum sensu 
vero familie nomen ferunt), aut definite, se non augentes (que cceenobium dicuntur). 


86 FRESH-WATER ALG& OF THE UNITED STATES. 


Propagatio fit gonidiis, que intra cellulam matricalem cytiogenesi libera oriuntur et duplicis indolis 
sunt; altera majora, que macrogonidia, altera minora quae microgonidia dicuntur ; illa oblonga, polo 
antico plerumque rostelliformi-producta, pallidiora, ciliis vibratoriis predita, polo postico truncato- 
rotundata, obscure viridia, individuum propagant; hec forma similii, itidem mobilia, brevi postea 
in statum quiescentem transeunt, druique in sporas perdurantes (Hypnosporas, Braun) transmu- 
tantur. (R.) 


Unicellular alge, in the strictest sense of the word, chlorophyllous, without terminal growth or 
true branching, without a vegetative generation of cells. They live either single, segregate, or con- 
sociated into families. The cells of these families, either indefinitely increasing in number (then 
families in the true sense of the term), or of definite number (then forming a ccenobium). 

Propagation by means of gonidia arising within the mother-cell by free cell-formation ; gonidia of 
two kinds; the one larger, macrogonidia—the other smaller, microgonidia; the former oblong, 
mostly produced into a pale bicilate beak anteriorly, rounded and greenish at their hinder end, 
developing into the individual plant; the microgonidia similar to these and also motile, but passing 
after a short time into a quiescent state, and at last into resting spores or hypnospores. 


Genus PROTOCOCCUS, Ag. 1824. 


Cellule spheroidex, segregate, cytiodermate tenui, hyalino, absque tegumentis, libere natantes 
vel extra aquam in stratum tenue pulvereum cumulate. Cytioplasma initio homogeneum, denique 
granulosum, viride vel rubellum. 


Spheroidal cells, segregate, cytioderm thin, hyaline, without integument, swimming free or col- 
lected out of water into a thin pulverulent stratum. Cytioplasm in the beginning homogeneous, 
finally granular, green, or reddish. 


Remarks.—I have introduced this genus as given by Professor Rabenhorsi in 
his Flora Europea Algarum for the purpose of describing a little plant, upon which 
I have made some observations. As the notes were originally drawn up as a de- 
scription of a species, I leave them in that form. I believe it has never before 
been described. 


Protococcus, (sp. nov. ?) 


P. aquaticus ; cellulis globosis vel angulis, viridibus in stratum pulvereum cumulatis vel in fami- 
lias arcte conjunctis; cytiodermate plerumque distincto; sporis rotundatis, tegumentis duobus 
vel tribus protectis; tegumentis externis, crassibus; zoogonidiis ovalibus, vel subrotundatis, 
vel subellipticis, ciliis duobus instructis. 


Diam.—Macx. spor. perdurant. 755” = .00093"; microg. 7455” = .00053”. 


Aquatic; cells green, globose or angular, accumulated in a green pulverulent stratum, often 
closely united into families; cytioderm mostly not distinct; resting spores round with two or 
three thick coats; zoospores oval or roundish, or somewhat. elliptical, furnished with two 
cilia. 


Remarks.—I found this species growing in a spring near Hestonville, West 
Philadelphia, in the month of March. ‘The large winter spores are round, with 
thick coats. Except in one instance, in which the color was a decided reddish- 
brown, all that I have seen have been green. How they are produced I do not 
know. ‘The history of their development into the plant appears to be as follows: 
The first change is the rupture of their outer thick coat (fig. 4 6, pl. 7) from which 
the spore finally escapes still clothed with a coat of moderate thickness. The 
green contents next divide into a number of oval bodies (fig. 68, pl. 7) which 


\ 


FRESH-WATER ALG OF THE UNITED STATES. 87 


grow, and, at the same time, separate from one another. Whilst these changes 
have been taking place the spore coat has been becoming gelatinous and enlarging, 
so that it continues to enclose its progeny. In this way a family of oval cells is 
formed (fig. 4, pl. 7). So far, I think, is positive. The next step I have never 
actually seen, but believe to be the escape of these oval bodies as zoospores (fig. 
4c, pl. 7) which are of very various sizes and are elliptical, globose, or oval. They 
have a tolerably well-marked bright vacuole at their beak, and after swimming 
about actively for a time finally settle down, lose their cilia, and undergo division. 


They seem often to cluster together before thus becoming quiescent, so as to make 
little colonies (fig. 5, pl. 7). 


Genus CHLOROCOCCUM, Friss. 


Cellule spheroidez, aut singule, liberse, vesicula chlorophyllosa et locello laterali pallidiori cavo? 
instruct, limbo hyalino et tegumentis sepe amplissimis cincte, aut plures in stratum vel acervulos 
cumulate. 


Propagatio fit zoogonidiis cytioplasmatis divisione ortis, e cytiodermatis abavie (intellige tegu- 
mentum extremum) rupturis excedentibus 


Cells spheroidal, either single, free, furnished with a chlorophyllous vesicle and a paler lateral 
(hollow ?) spot, with a hyaline nimbus and surrounded by a wide coat; mostly accumulated together 
into strata or little heaps. Propagation by means of zoospores, which are formed by a division of 
cytioplasm and escape from their general tegument (the cytioderm of the original cell). 


Remarks.—But a few weeks after the commencement of my study of fresh- 
water alge, a friend, a young microscopist, asked me to look at his aquarium, as 
the water of it had become stagnant, opaque, and green. On examining a little 
of the water with the microscope it was found to be full of what I now know to 
have been either one of the forms already described under this genus, or else one 
undescribed, but still embraced within its limits. ‘There were two sets of bodies, 
the one motile the other at rest. The motile forms (Fig, 5, pl. 3) were globular or 
pyriform, and generally contained a large, roundish, green, distinct mass. They were 
of course provided with cilia, although at that time I was not able to demonstrate 
their presence. These bodies, even when moving, appeared to have a distinct 
wall. After a time they settled down and assumed the quiescent state. The 
outer coat now rapidly enlarged so as to leave a considerable space between it and 
the green endochrome, which rapidly underwent division, forming two or more 
new cells which were still surrounded by the enlarged maternal coat. The num- 
ber of daughter-cells enclosed in the parent cell varied. A considerable quantity 
of the water was allowed to stand in a glass jar, exposed to the light. In a very 
few days all the motile forms had disappeared. The contents of the vessel were 
allowed slowly to evaporate. ‘The jar being tall and narrow it was some weeks now 
before this process was completed, before which consummation haematococcus forms 
were abundantly developed. 

Instead of being green, and surrounded by a distant, almost sac-like wall, the cells 
had acquired a dark brownish-red color, were very opaque, and were protected by 
a thick wall, whose surface was quite rough. Unfortunately, I did not measure 
either the active gonidia or their progeny, the quiet cells, but I found the general 


88 FRESH-WATER ALGZ OF THE UNITED STATES. 


diameter of these hematococcus cells to be one twelve-hundredth of an inch 
(.00083"). 

MM. Famnitzin and Boranetzky, in arecent paper (“Zur Entwickelungsgeschichte 
der Gonidien und Zoosporenbildung der Flechten,” Mem. de L’ Académie Impériale 
des Sciences de St. Petersbourg, 1868, Annals and Mag. Nat. History, Feb. 1869), 
state as the result of direct observation that this genus of algz, so called, is really 
a stage in the life history of the gonidia of lichens. These gentlemen took thin 
slices of lichen thalli containing gonidia, and placed them upon pieces of fir and 
linden bark, which had been previously boiled to kill any plants that might be 
growing on them. ‘These were then put ina glass jar inserted over a vessel con- 
taining water, in such way that they would be constantly exposed to a very damp 
atmosphere, and at the same time communication with the external air would be 
impossible. In another set of experiments, pieces of the lichens were allowed to 
lie for a long time in water, until the component filaments were decomposed into 
a gelatinous mass, in which the still green vigorous gonidia were imbedded. ‘These 
pap-like (breiige) masses were then washed with pure water and smeared upon 
pieces of linden bark. ‘The results obtained were identical.in the two cases. ‘The 
gonidia were at first provided each with a distinct nucleus and a well-marked 
lateral vacuole, and resembled closely the first form of cystococcus. The next 
change was a division of their contents into a large number of roundish masses, 
with the disappearance both of the vacuole and of the central nucleus. The cell- 
membranes were next ruptured, and the endochrome, protruding through the open- 
ing, formed a little ball sittimg upon the parent cell. In doing this it doubled 
in size, so that the part without was as large as the part within, although the latter 
still filled the cell. The contents finally escaped, but were yet surrounded by a 
very thin membrane, which soon, however, ruptured, and freed the biciliated 
zoospores into which the endochrome had in the mean time resolved itself. These 
zoospores remained a long time in the motile state, but finally settled down, drop. 
ping their cilia, and became little round cells, which grew to three or four times 
their original size. Further development was not made out. 

Certain of the gonidia, belonging to a lichen of the genus Physcia, failed to 
produce zoospores, but their endochrome, divided so as to form a number of 
quiescent cells, which either ruptured very early the original cell-membrane and 
became free in the water, or else remained bound together by it into a family for a 
longer period. In these researches MM. Famnitzin and Boranetzky employed 
lichens of three genera, namely Physcia, Cladonia, and Evennia, and claim, as 
above stated, that their investigations prove that they developed the alge genus 
Cystococcus of Negeli (Chlorococcum, Fries), from the gonidia. 


Genus POLYEDRIUM, Naezti, (1849.) 


Cellule singule, segregate, libere natantes, compresse, 3-4-8 angulares, angulis plus minus pro- 
duct, nonnunquam radiatim elongate, aut integre aut bifide, plerumque armate, a latere oblongo- 
elliptice, utroque polo rotundate vel subtruncate. Cytioderma tenue, leave. Massa chlorophyl- 


lacea plerumque granulosa, per cellule lumen equaliter distributa, nonnunquam guttulis oleosis 
rubris 1-4 mixta. 


Propagatio adhuc ignota. (R.) Genus mihi ignotum. 


FRESH-WATER ALG OF THE UNITED STATES. 89 


Cells single, segregate, swimming free, compressed, 3-4—8-angled, more or less produced as to their 
angles, sometimes radiately elongate, either entire or bifid; mostly armed, oblong-elliptical when 
viewed laterally, at each end rounded or subtruncate. Cytioderm thin, smooth; chlorophyl mostly 
granular, equally distributed through the cell, sometimes mixed with reddish oil-drops. 

Propagation unknown. 


Remarks.—This genus was described by Negeli in his “Gattungen Einzelliger 
Algen,” and, although I have never seen any specimen of it, it claims a place here, 
because one species has been found in this country by Prof. Bailey. 


P. enorme, (Rats) Dez Bary. 


P. tetraédiicum, angulis productis achrois profunde bilobis, nonnunquam repetito-bilobis, lobis 
mucronatis. (R.) 


Diam.—0.0011”—0.0016". (R.) 


Syn.—P. enorme, (Raurs) De Bary. Rasennorst, Flora Europ. Algarum, Sect. III. p. 62. 
Staurastrum enorme, RA.rs, British Desmidiez. 


Hab.—Florida. Bailey. 


“Frond irregular or quadrate, spinous; end view three or four-lobed; lobes broad, more or 
less emarginate or bifid, and terminated by spines, which are either simple or branched. 
Sometimes the front view differs but little from the end one, usually, however, there is a 
slight constriction or sinus at the junction of the segments, but I have never observed any 
difference in the endochrome at that part. The spines, which are almost confined to the 
angles, are irregular, some simple and some branched. ‘The end view has three or four broad 
and very irregular lobes ; these are spinous and more or less emarginate, and frequently one 
lobe is much broader and more spinous than the others. The spines on such lobe form two 
groups, separated by the notch; they vary much in size and are either simple and subulate, 
or else forked; sometimes the forked spines are again divided at the apex.”—Ralfs’ British 
Desmidieex, p. 141. 


Genus SCENEDESMUS, MEyren. 


Cellule polymorphs, utroque polo equales vel insequales, sepe in cornu spiniforme producte, in 
zetate perfecto 2-16 aut in seriem simplicem aut parenchymatice arcte conjuncte et ccenobium con- 
stituentes ; cytioplasmate initio homogeneo, postea granuloso, vesicula chlorophyllosa centrali vel 
sublaterali et seepe locello achroo laterali instructo. . 

Propagatio fit cytioplasmatis divisione succedanea, unde gonidia oriuntur, que intra cellulam 
matricalem jam in ceenobium planum sese conjungunt et membrane matricalis ruptura vel dissolu- 
tione prodeunt. 

Cells polymorphous, equal or unequal at the ends, often produced into a spine-like horn, in the 
perfect state 2-16 closely conjoined, either as a simple series or in a parenchyma-like manner so as to 
form.a cenobium. Cytioplasm in the beginning homogeneous, afterwards granular, furnished with 
a. central or sublateral chlorophyllous vesicle, and often with a lateral transparent spot. 

Propagation occurring as a succedaneum to the division in the cells, whence arise gonidia, which, 
already within the mother-cell, join themselves into a coenobium, and are finally set free by the rupture 
and dissolution of the maternal cell-wall. 


Remarks.—According to Unger, in the genus Scenedesmus the cells never exist 
singly, but always in families. 
Two of the species here described as representatives of the genus certainly do 


not conform to this, for I have frequently seen them both separate and in ccenobia 
12 May, 1872. 


90 FRESH-WATER ALG&Z OF THE UNITED STATES. 


or families. The latter were exactly like those of the European forms, at least 
in one of the two species, and I do not therefore think it justifiable to indicate a 
new genus. Moreover, I have certainly seen single cells, belonging to a species 
which agrees precisely in its characters with a European form, save only in the 
occasional existence of these single cells. 

I have never studied the method of propagation, but it is said to occur by the 
division of the cytioplasm of a large cell into a minute ccenobium composed of 
two or more cells, which remains for some time within the walls of the mother- 
cell, but is finally set free by the solution of the latter. 

The cells are mostly much longer than broad, cylindrical, elliptical, or sive; but 
in one species herein described they are habitually globular. 


a. Cellule inermes. 


a, Cells unarmed. 


S. obtusus, Mryen. 
S. cellulis oblongis vel ovatis, utroque polo obtusis, 4-6-8 modo arcte modo laxe in ‘seriem 
simplicem aut rectam aut duplicem obliquam conjunctis, diametro 3-5 plo longioribus. (R.) 


Diam.—Transv. max. 0.00023”—0.00028”. (R.) 
Syn.—S. obtusus, MEYEN. RaBENHORST, Flora Europ., Algarum, Sect. IIT. p. 63. 
Hab.—Georgia: Rhode Island, Bailey. 


Cells oblong or ovate, obtuse at each end, 4-6-8, partly closely partly laxly conjoined into a 
simple series either straight or oblique and double, 3-5 times longer than broad. 


Remark.—I have never met with this species. 


S. acutus, Mryven. 
8. cellulis fusiformibus, vel ovato-fusiformibus vel ovatis, utrinque acutis sed inermibus, inter- 
dum singulis sed plerumque in seriem aut simplicem rectam aut duplicem inordinate alter- 
nantem dispositis, arcte concretis, diametro 2-4 (6?) -plo longioribus. 


Diam.—Trans. vag. max. ? .00016". 

Syn.—S. acutus, MEvyEN. Rasennorst, Flora Europ. Algarum, Sect. ITI. p. 64. 
Hab.—Prope Philadelphia, Wood. Rhode Island, Bailey. 

Cells fusiform, or ovate-fusiform or ovate, acute at each end but unarmed; sometimes single 


but mostly conjoined into a single straight series or into an irregularly alternate double series, 
2-4 times longer than broad. 


Remarks.—This species is common around Philadelphia. Our specimens agree 
very well with the descriptions and figures of the European, excepting that occa- 
sionally a cell is single, and that none which I have measured have attained the 
size given by Prof. Rabenhorst as the maximum, namely, 0.00023”, According 
to Rabenhorst, S. obliquus, Ktz., is only a variety of S. acutus, Meyen. It has 
been found by Prof. Bailey in South Carolina, Georgia, and Rhode Island. 


b. Cellule armate. 
b. Cells armed. 


FRESH-WATER ALGA OF THE UNITED STATES. 91 


S. polymorphus, Woop. 

8. cellulis fasiformibus, aut ovalibus aut ellipticis aut globosis, singulis aut 2-8 conjunctis, 
plerumque utroque polo aculeo unico, interdum aculeis duobus, instructis: apicibus obtusis, 
acutis, vel acutissimis ; aculeis gracillimis, rectis, modice elongatis, inclinatis. 

Diam.—g355"—73'00" 5 plerumque zy'50"- 

Syn.—S. polymorphus, Woop, Prodromus, Proc. Am. Philos. Soc., 1869, p. 185. 

Hab.—In aquis quietis prope Camden, New Jersey. 

8. cells fusiform, or oval, or elliptic, or globose, single or 2-7 conjoined, furnished in most 


cases with a single spine, sometimes 2, at each end; ends obtuse, acute, or very acute; spines 
exceedingly slender and acute, straight, moderately long, inclined. 


Remarks.—This plant was found in a quiet pool, filling the water in such num- 
bers as to make it opaque and very green. The color of the cells, as first obtained, 
under the microscope, was a vivid green, but, the water containing them having 
been placed in a dish, during the slow desiccation which followed the color ot the 
cells changed to a golden yellow. 

Fig. 1, pl. 11, represents different forms of this species magnified 450 diameters. 


S. quadricauda, (Turpin) Brés. 


S. cellulis oblongo-cylindricis, utroque polo obtuse rotundatis, 2-4-8 arctissime conjunctis, 
ordine aut simplici recto aut duplice alternante, omnibus rectis, medianis inermibus vel his 
illisve apice uno alterove aculeo curvato instructis, extimis utroque apice sapius item dorso 
armatis. 


Diam.—0.00035"—0.00039"; long. 0.00091”. 
Syn.—S. quadricauda, (TurPIN) Bris. Rapennorst, Flora Europ. Algar., Sect. IIT. p. 65. 
Hab.—Rhode Island, Bailey. Pennsylvania, Wood. 


Cells oblong-cylindrical, obtusely rounded at each end, 2~4~8 very closely conjoined either in a 
single straight series or a double alternating one, all straight, the median unarmed or some of 
them with the apex furnished with a curved spine, the external with both apices and some- 
times the dorsum thus armed. 


Remark.—Fig. 2, pl. 11, represents this species magnified 750 diameters. 


S. rotundatus, Woop, (sp. nov.) 
8. cellulis globosis vel subglobosis, spinulis longissimis, rectis, gracillimis, acutissimis, 3-6 
armatis, aut singulis aut geminis aut 3-4 arcte duplice conjunctis. 
Diam.—gygn" t0 sy'50" 
Hab.—In aquis quietis prope Philadelphia. (Dr. Chapman.) 
Cells globose or subglobose, armed with three to five very long, slender, acute, straight spines, 
single or in pairs, or three to four closely conjoined in a twofold rank. 


Remarks.—The cells of this species are globular, and, when more than two, 
they are arranged in two rows placed.at right angles one to the other. ‘The con- 
tents of the cells are markedly granular, and the endochrome a bluish-green, and 
from the surface of the walls project outwards, very long and fine, rigid hair-like 
spines. 

It seems scarcely correct to place this plant in the genus Scenesdesmus, but I do 


92 FRESH-WATER ALG& OF THE UNITED STATES. 


not know any other genus to which it is more closely allied, and do not feel dis- 


posed to indicate a new one for it. 
Fig. 3, pl. 11, represents a cell-family magnified 250 diameters. 


Genus HYDRODICTYON, Roru. (1800.) 


Cellule oblongo-cylindrice, in ccenobium reticulato-saccatum connexe#, omnes fertiles; alice 
procreant macrogonidia, que jam intra cellulam matricalem in ccenobium filiale se connectunt ; alice 
microgonidia, que multo minora, cellule matricalis membranam perrumpunt, polo antico ciliis vibra- 
toriis binis et puncto rubro laterali predita sunt, brevi postea in globulos protococcoideos tranquillos 
transformata sporas perdurantes efficiunt. 


Cells oblong-cylindrical, joined into a reticulated saccate ccenobium, all fertile; some producing 
macrogonidia, which join themselves into a cenobium within the parent cell; the others producing 
microgonidia, which are furnished with two vibratile cilia and a lateral red spot, and which, escaping 
from the parent cell, are, after a brief period of motile life, transformed into protococcoid thick-walled 
spores. 


Remarks.—The genus Hydrodictyon comprises, as far as known, but a single 
species, which is common to North America and Europe. It grows in great 
abundance in the neighborhood of Philadelphia, especially in the ditches and 
stagnant brick-ponds in the low grounds below the city known as the “ Neck.” 
‘There it very frequently forms floating masses several inches in thickness and 
many feet in extent, so that with the aid of a rake it could be gathered by the 
bushel. When thus in mass the color is very generally dingy and yellowish, 
although the fronds, when in active vegetative life, are mostly of a bright, beauti- 
ful green. The plant is in greatest profusion in June and July, after which time 
it gradually disappears, until in the autumn it is scarcély to be found, but early 
in the spring it reappears. ‘The very young fronds are minute, oval, cylindrical, 
filmy-looking, closed nets, with the meshes not appreciable to the eye ; when growth 
takes place, the fronds enlarge until finally they form beautiful cylindrical nets 
two to six inches in length, with their meshes very distinct and their ends closed. 
In the bright sunlight they, of course, by virtue of the life-functions of their chlo- 
rophyl, liberate oxygen, which being set free in the interior of the net, and its 
exit barred by the fine meshes, collects as a bubble in one end of the cylinder and 
buoys it up, so that, the heavier end sinking, the net is suspended, as it were, ver- 
tically in the water. I know of few things of the kind more beautiful than a jar 
of limpid water with masses of these little nets hanging from the surface like cur- 
tains of sheen in the bright sunlight. A few cells collected in the fall or early 
spring, if put into a preserving-jar and the water occasionally changed, will multi- 
ply, and in a little while become a source of frequent pleasure to the watcher. 

As the fronds increase in size they are always in some way or other broken up 
so that, instead of being closed cylinders, they appear as simple open networks of 
less or greater extent. ‘The extreme length to which the frond attains is, I think 
very rarely over twelve inches, with meshes of about a third of an inch in length, 
The construction of the frond is always the same. It is composed of cylindrical 
cells united end to end in such a way as to form polygonal, and mostly pentagonal 


FRESH-WATER ALG#A OF THE UNITED STATES. 93 


meshes, the size of which varies with the age of the plant. These cells, 
which are closely conjoined but have no passage-ways between them, are capable 
of independent life, so that the hydrodictyon may be looked upon as an elaborate 
type of a cell-family, one in which cells are conjoined in accordance with a defi- 
nite plan, so as to make a body of definite shape and size, yet in which each cell 
is an independent being, drawing nothing from its neighbors, The cells them- 
selves are cylindrical, with a thickish cellulose wall, and have no nuclei. Their 
chlorophyllous protoplasm is granular, and is placed in the exterior portion of the 
cell, forming thus, within the outer wall, a hollow cylinder, in which are imbedded 
starch granules, and whose interior is occupied with watery contents. The hydro- 
dictyon cell, when once-formed, is capable of growth, but not of going through the 
usual process of cell multiplication by division, so that the adult frond is com- 
posed of just as many and indeed the same cells, as it had in its earliest infancy. 

No true sexual reproduction has as yet been discovered in the water-nets. There 
have been described, however, two forms or methods in which the species multi- 
plies, both of them occurring by means of motile zoosporoid bodies. In the one 
case these develop immediately into the new plant, whilst in the other before 
doing so they pass through a resting stage. Of the life-history of the latter, the 
microgonidia, I have no personal knowledge. 

The investigation of the production and development of the macrogonidia, how- 
ever, has occupied considerable of the time devoted by myself to the microscope, 
and I have seen large numbers of specimens in almost all the stages of develop- 
ment. EF have never been able to detect, however, any decided motion in the 
macrogonidia. 

They are formed in the protoplasmic stratum, already alluded to as occupying 
the outer portion of the interior of the hydrodictyon cell. The first alteration in 
this, presaging their formation, is a disappearance of the starch granules, and a 
loss of the beautiful, transparent green color. Shortly after this, even before all 
traces of the starch-grain are gone, there appear in the protoplasm numerous 
bright spots placed at regular intervals; these are the centres of development 
around which the new bodies are to form. As the process goes on, the chlorophyl 
granules draw more and more closely around these points, and at the same time 
the mass becomes more and more opaque, dull, and yellowish-brown in color, This 
condensation continues until at last the little masses are resolved into dark hexa- 
gonal or polygonal plates, distinctly separated by light, sharply defined lines. In 
some, the original bright central spot is still perceptible, but in others it is entirely 
obscured by the dark crowded chlorophyl. The separation of these plates now 
becomes more and more positive, and they begin to become convex, then lenticular, 
and are at last converted into free, oval, or globular bodies. When these are fully 
formed, they are said to exhibit a peculiar trembling motion, mutually crowding 
and pushing one another, compared by M. Braun to the restless, uneasy movement 
seen in a dense crowd of people in which no one is able to leave his place. Whilst 
the process just described has been going on, the outer cellulose wall of the hydro- 
dictyon cell has been undergoing changes, becoming thicker and softer and more 


94 FRESH-WATER ALG#H OF THE UNITED STATES. 


and more capable of solution, and by the time the gonidia are formed it is enlarged 
and cracked, so that room is afforded them to separate a little distance from one 
another within the parent cell. Now the movements are said to become more 
active—a trembling jerking which has been compared to the ebullition of boiling 
water. There is, however, with this a very slight change of space, and in a very 
short time the gonidia arrange themselves so as to form a little net within the 
parent cell, a miniature in all important particulars of the adult hydrodictyon. 
The primary cell-wall now becomes more and more gelatinous, and soon undergoes 
complete solution, so that the new frond is set free in its native element. As pre- 
viously stated, in my investigations I have never seen the peculiar motion above 
described, the newly formed gonidia simply separating and arranging themselves 
without my being able to perceive any motion, or exactly how they fell into posi- 
tion. 

It is evident that when the species is multiplied in the way just described, the 
birth of the new frond is consentaneous with the death of the old cell. But when 
the hydrodictyon disappear in the fall, it is months before they reappear in the 
spring. It is, therefore, evident there must be some other method of reproduction. 
This slow development of new fronds takes place, according to Pringsheim, by 
means of little motile bodies which he calls “ Dauerschwiirmer,” which has been 
translated into English chronispores (statospores, Hicks). M. Braun stated already 
some years since that sometimes, instead of the hydrodictyon producing the ordi- 
nary reproductive bodies (macrogonidia), there are formed in the cells much smaller 
and more active bodies, the microgonidia, ‘The changes which occur in the pro- 
duction of these are very similar to those already described as happening when 
the macrogonidia are formed. When the chronispores are once formed, however, 
they, instead of uniting together escape in a free distinct condition into the water. 
They are now small ovate bodies, with a large anterior transparent space, to which 
are attached a pair of cilia, and their life and history, according to Pringsheim, is 
as follows: For a few hours they move about very actively in the water, and then, 
dropping their cilia, and acquiring an outer cellulase wall, pass into a quiescent 
stage, in which they closely resemble protococcus granules. ‘They are capable of 
living in this state for a long time, if kept in water. They can also endure desic- 
cation if the light be excluded during the process, but, if it be present, they wither 
and die, and cannot be revivified. 

After a longer or shorter period, but never shorter than three months, according 
to Pringsheim, they recommence their life, provided they be in water. For four 
or five months after this the chief change consists simply in an increase in size, 
The dark-green protoplasm is arranged around the exterior of the cell, within are 
the more fluid colorless contents, the whole body still looking like a protococcus 
cell. After a size of about 7; mm. is attained, the endochrome divides succes- 
sively into several portions, The external layers of the surrounding wall now 
give way in some spot and allow the inner layers to protrude and form a sort of 
hernial sac, into which the several endochrome masses soon pass, at the same time 
assuming the well-known characters of true zoospores, From two to five of these 


FRESH-WATER ALGA OF THE UNITED STATES. 95 


bodies are thus produced out of each original microgonidium. They are large 
ovate, biciliate, and, generally, soon escaping from the hernial sac, move abeut 
actively in the water for a few minutes. Sometimes, however, they settle down 
within the generative utricle. In either case, after a little time, they become 
motionless, lose their cilia, and develop into polyhedral cells, which are structurally 
remarkable for having their angles prolonged into long horn-like appendages. Under 
favorable circumstances, at the end of a few days, the bright green endochrome of 
these undergoes similar changes to those described as presaging the production of 
the microgonidia, and is finally formed into zoospores, which, in from twenty to forty 
minutes, unite, within the polyhedron or large cell, into a Hydrodictyon, which is 
finally set free by a solution of the cellulose coat of the polyhedron. ‘The network 
thus formed differs in no essential way from that which arises in the better known 
way, except that it is composed of much fewer cells. It is generally a closed 
sac; but when the polyhedron, out of which it is developed, is small, it is some- 
times merely an open network. Its after-history appears to be identical with that 
of the ordinary hydrodictyon frond. 


MH. utriculatum, Rors. 
Species unica. 
Syn.—H. utriculatum, Rota. Rasenuorst, Flora Europ. Algarum, Sect. III. p. 66. 
Hab.—In aquis quietis. West Point, Bailey. Weehawken, (Mr. Walters.) ‘‘ Waterholes 
between Van Horn’s Mills and Mueote on the Mexican boundary, Dr. Bigelow. Pennsyl- 
vania, Wood. 


Genus PEDIASTRUM, Meyen, (1829.) 


Ceenobium planum, disciforme, libere natans, e celluarum strato unico, rarius centro entro duplicato, 
continuo vel perforato formatum. Cellule polygoniz, peripherice szpe bilobe, lobis cuneatis et 
simplicibus et bidentatis, nonnunquam in cornua productis. 


Ceenobium plain, discoid, swimming free, formed of cells in a single, rarely in the centre double 
stratum, which is continuous or perforate ; cells polygonal, the peripheral often bilobed, the lobes 
cuneate, either simple or bidentate, sometimes produced into a horn. 


Remarks.—The ccenobium or cell-family, or colony, in the genus Pediastrum is 
always discoid, and has generally a more or less truly circular outline. The cells 
are mostly in a single stratum, but in some species there are two, more or less, 
complete strata superimposed one upon the other. The arrangement of the cells 
in this stratum, or these strata, varies greatly, as does also their number. They 
are mostly more or less polyhedral, and often have their margins scooped out or 
their angles prolonged. This may occur in such a way that the projecting point 
of one cell fits into the hollow in its neighbor, and the ccenobium be rendered 
entire, or, no such relation existing between the parts of adjacent cells, the coeno- 
bium may be perforated with regular or irregular openings. The outer or mar- 
ginal cells are often deeply notched externally, and frequently are prolonged into 
acute or obtuse lobe-like processes. The walls of the cells are, in adult specimens, 
quite thick. The contents consist of chlorophyl, protoplasm, starch granules, &c. 


96 FRESH-WATER ALGAZ OF THE UNITED STATES. 


There are generally one or more hyaline spaces, besides a distinct chlorophyl 
vesicle, but no distinct nuclei. 

At certain periods of their existence the Pediastrums produce both macrogonidia 
and microgonidia. The life-history of the former is very similar to that of the 
same bodies in the water-nets. The ultimate fate of the microgonidia has not as 
yet been determined, but in all probability they go through cycles of change 
similar to those seen in the lives of the corresponding bodies in the Hydrodictyon 
utriculatum. I have not had an opportunity of watching the development of 
either of these reproductive forms, but, according to MM. Braun, Pringsheim, &c., 
their life-history, as far as known, is as follows: In most cases, all the cells of a 
pediastrum produce their macrogonidia simultaneously, or within a very short 
period of time, so that the ccenobium will be left emptied of its contents as a mere 
shell, the outer skeleton of its former self. When a cell is about to give birth to 
these reproductive bodies, the endochrome divides into two parts; each of which 
then undergoes a similar binary division. This is repeated once, twice, thrice, or 
oftener, until the endochrome is divided into 8-16-32-64 gonidial masses, the 
number of which, generally, but not always, corresponds to the number of cells in 
the colony, to which the parent-cell belongs. After the division of the endochrome 
is completed, a slit occurs in the outer strata of the wall of the mother-cell through 
which a hernial protrusion of the inmost stratum occurs. The protruded part 
now rapidly enlarges until at last there is formed a sort of hourglass-shaped sac, 
one portion of which is within, fhe other part without, the old parent-cell: 
Whilst this has been going on a portion of the gonidia have escaped from the 
parent-cell into the outer free portion of the sac, and each end of the hourglass, 
therefore, contains some of them. The sac with its contents now gradually 
withdraws itself more and more from the parent-cell until at last it lies a free 
globose vesicle in the water. The gonidia occupy the centre, and M. Braun states, 
that, although he has never been able to demonstrate any cilia upon them, yet 
they have an active swarming motion. At first, they are irregularly heaped toge- 
ther in the nearly filled sac; but the latter rapidly enlarges and elongates, and the 
gonidia in a little while arrange themselves in a flat, tabular group within it, and 
cease to move. ‘Then the several individuals of this group begin to develop, 
becoming emarginate and assuming the form of the parent-cell, until, finally, they 
have all grown into the shape which is peculiar to the adult cells of the species, 
and after a few hours have closely cohered to form a young conobium. 

The microgonidia are formed in a very similar way by the dividing of the endo- 
chrome, the cracking of the outer membrane, and the protrusion and final escape 
of the inner. ‘They are, however, much smaller and more numerous than the 
macrogonidia. When the parent vesicle first escapes into the water, they are 
crowded in its centre, and are nearly globose. As it enlarges, however, they elon- 
gate more and more, and finally become distinctly bi- or, more rarely, uni-ciliate. 
The cilia are much longer than the body, and are attached to the smaller end, 
which is prolonged into a pointed, transparent beak, about equal to the green por- 
tion in length. The microgonidia now become more and more restless, they, moving 
about very actively, and after awhile bursting the parent sac, escape into the water. 


FRESH-WATER ALGA OF THE UNITED STATES 97 


What becomes of them after this, as has been stated, is a mere matter of conjec- 
ture. M. Braun’ and others have described unicellular forms of several of the 
multicellular species of Pediastrum, and Pringsheim suggests that these are really 
polyhedrons developed out of these microgonidia, as is seen in the water-nets. 
‘This, of course, may or may not be the case. 


P. Boryanum, (Turpin) Mena. 

P. cenobio orbiculari, oblongo vel elliptico, magnitudine vario, continuo, lete viridi, e cellulis 
4-8-16-32-64 (rarissime 128) composito (cellularum strato simplici, nonnunquam medio 
duplicato); cellulis periphericis plus minus profunde emarginatis vel bilobis, lobis cornutis, 
cornibus achrois hyalinis, abbreviatis vel elongatis, teretibus, obtusis vel subobtusis, interdum 
capitellato-incrassatis, centralibus arctissime concretis, polygonis (4-6 angularibus), in antica 
parte modo angulo prominulo modo plane truncatis, modo leviter repandis, omnium mem- 
brana decussatim punctata. (R.) 


Diam.—Transyv. cell 0.000795" ; rarius 0.00088”—0.00094”. (R.) 


Syn.—P. Boryanum, (Turpin,) MENGHINI. Ragenuorst, Flora Europ. Algarum, Sect. III. 
p. 74. 

Hab.—Georgia, Florida, Rhode Island, Bailey; Pennsylvania, Wood. 

Cells arranged in one or more circles round one or two central cells ; the inner variable, generally 


concave at one side, the outer tapering into two long subulate points, the notch narrow. 
L. 1-2088” to 1-1633"; B. 1-2733” to 1-2222”. (Archer.) 


P. Selenza, K1z. 
P. cenobio orbiculari, integro, e cellulis 8-16 (rarius 31=1+4+5-+10+4 15, Krz.) formato; 
cellulis periphericis angustis, lunatis, acute lobatis, disci cellulis leviter excisis, centrali unica 
5-angulari, omnium membrana firma, subcrassa, ztate provecta rubescente. (R.) 


Diam.—Ceenobii 0.00124"—0.0035"; cell. (distantiz interlobos) 0.00026”—0.00069". (R.) 
Syn.—P. Selenxa, Krz. RaBenuorst, Flora Europ. Algarum, Sect. III. p. 73. 


Hab.—-Rhode Island, Bailey. 
Cells crescent-shaped, arranged in one or more circles round one or two central ones, connecting 
medium colored. (A.)? 


P. pertusum, Krz. 
P. cenobio orbiculari, lacunis pertuso, magnitudine vario, e eellalis plerumque 1+5+10+415 
(in formis quibusdam ad 64) composito; cellulis periphericis basi tantum laxe connexis, ad 
medium usque bilobis, lobis rectis, in cornua hyalina modo subacuta modo obtusa vel trun- 
cata plus minus productis, centralibus plus minus exacte quadrangularibus, et in antica parte 
et utrinque emaginatis, omnibus levibus, locellis pallioribus finis instructis. (R.) 


Diam.—tTransv. cell. perfecte evolut. circiter 0.00065”—0.00089". (R.) 


Syn.—P. pertusum, Krz. Rasenuorst, Flora Europ. Algarum, Sect. IIT. p. 75. 

Cells arranged in circles round one or two central ones; inner cells quadrangular, sides concave 
and leaving angular vacant intervals; the outer cells with square bases, externally triangu- 
larly notched, the subdivisions tapering to an acute point. L. 1-2266”; B. 1-3268". (A.) 


P. constrictum, Hassat. 
P. cceenobio orbiculari vel suborbiculari, lete viridi, continuo, levi?, e cellulis 16 (ad 1+5 + 
10) vel 32 (ad 1 +6 -+10-+ 15) formato; cellulis periphericis irregulariter bilobis, sinu 


1 The best exposition of this genus is to be found in Braun’s Unicellular Alge. 
2 The letter A used here signifies that the description is copied from Mr. Archer in Prichard’s Infu- 


soria. 
13. June, 1872. 


98 FRESH-WATER ALGHE OF THE UNITED STATES. 


angusto, lobis inequalibus, basi plerumque constrictis, in cornua subcrassa obtusa productis, 
centralibus polygonis, in antica parte repandis. (R.) 


Syn.—P. ellipticum, HassaL. RABENHORST, Flora Europ. Algarum, Sect. III, p. TT. 
Hab.—South Carolina, Georgia, Rhode Island, Bailey. 


Cells varying in number and arrangement; outer cells suddenly contracted into two short, 
cylindrical, obtuse processes. L. 1-1754” to 1-906”; B. 1-1515” to 1-1020". 
g, Processes of the lobes truncately emarginate. (A.) 


P. Ehrenbersgii, (Copa) Braun. 

P. ceenobio et orbiculari et oblongo, perfecte clauso, e cellulis 8 ¥el 16 composito et quadrato, 
e cellulis 4, late cuneatis, profunde lobatis, exacte cruciatim dispositis formato ; cellulis peri- 
phericis-cuneatis a basi truncata ad apicem usque concretis, profunde bilobis sinu angusto, 
lobis sepe oblique truncatis, plus minus sinuato-excisis, angulis interioribus ad duplum lon- 
gioribus, omnibus acutis vel breviter appendiculatis; cellulis centralibus aut singulis aut 
pluribus (2-5-6 v. 8), omnibus flavo-viridibus, polygovis, uno latere repandis vel profunde 
incisis. (R.) 

Syn.—P. Ehrenbergii, (Corpa,) Braun. RaBENHORST, Flora Europ. Algarum, Sect. III. p. 77. 

Hab.—South Carolina, Georgia, Florida, Rhode Island, Bailey. 


Frond minute; cells eight (seven disposed in a single series round a central one), bilobed,. 
angular. L. 1-2900"; B. 1-2500". (A.) 


P. simplex, Mrven. 
P. cellulis periphericis ovato-cuspidatis, 8-10-16 basi tantum concretis, circulum simplicem 
constituentibus, centralibus sepe nullis. (R.) 


Syn.—P. simplex, Mryen. Rasennorst, Flora Europ. Algarum, Sect. III. p. 71. 
Monactinus octonarius, BAtLeY, Smithsonian Contributions. 
Hab,—South Carolina, Rhode Island, Bailey. 


Var.—duodenarius. 
Ceenobio clathrato, cellulis periphericis 12, centralibus 4, regulariter cruciatum dispositis. (R.) 


Syn.—Monactinus duodenarius, BAILEY. 


Inner cells four, somewhat triangular, enclosing a central, quadrate vacant interval, and four 
broadly lanceolate vacant intervals between them and the outer series, to which they are 
united by their terminal angles, outer cells twelve, subovate, truncate below, much attenuated, 
acuminate. (A.) 


Famy VOLVOCINEA. 


Ceenobia mobilia, globosa, subglobosa vel quadrangulo-tabulata, e cellulis viridibus cilia bina 
agilia gerentibus, intus vesica duplici contractibili preditis composita, membrana (tegumento, 
chlamyde) communi achroa hyalina plus minus ampliata involuta. : 

Propagatio aut sexualis, monoica vel dioica (adhuc in paucis tantum generibus probata) ; cellulis 
cenobii aut omnibus aut quibusdam genus masculinum vel feminum exhibentibus, illis in fasciculos 
spermatozoideorum (autheridia), has in oosporas episporio inclusas, non mobiles commutatis, aut 
non sexualis, gonidiis agilibus, (et macrogonidiis et microgonidiis—etiam zoogonidia vocantur). 
Macro- et microgonidia (cellule primordiales) cytioplasmatis divisione simultanea et multiplici orta; 
priora numero definita (2-4-8-16, &c.), majora oblonga vel rotundata, polo antico plus minus postel. 
formi producta, ciliis binis per vesicee membranam exsertis, puncto (ocello Ehrberg. stigma) sanguineo 
centrali vel parietali et locellis (vacuolis) spe binis contractibilibus instructa; ultima numero indefi- 
nita, multo minora, pallide vel sordide viridia vel luteola, apice ciliis instructa, pleramque jam intra 
cellulam matricalem vivide vacillantia, postea membrane ruptura libere erumpentia, examinantia. (R.) 


FRESH-WATER ALG OF THE UNITED STATES. 99 


Ceenobium mobile, globose, subglobose or in square tables, composed of green cells which have 
two motile cilia and a double contractile vesicle. The common tegument surrounding the cenobium 
hyaline, and more or less amplified. 

Propagation either sexual or non-sexual. The sexual monecious or diecious; either all or some 
of the cells of the cceenobium exhibiting male and female characters. The male cells containing 
spermatozoids, the female finally converted into a quiet oospore. Non-sexual propagation taking 
place by means of motile gonidia (both macrogonidia and microgonidia, by some called zoogonidia). 
Macro- and micro-gonidia arising by the simultaneous and repeated division of the cytioplasm; the 
first definite in number (2-48-16, &c ), the larger, oblong or rounded, with the anterior end more 
or less rostellate, with two cilia exserted through the membrane of the vesicle, furnished with a cen- 
tral or parietal red spot, and often with two contractile vacuoles; the microgonidia indefinite in 
number, much the smaller, pale or dirty green or luteolous, furnished at the apex with cilia, mostly 
even within the mother-cell, moving rapidly, and finally escaping on the rupture of the membrane. 


Genus CHLAMYDPOCOCCUS, A. Braun. 


Cellule globose, vel subglobose (4-8 in ccenobium fugacissimum conjuncte), cytiodermate sub- 
crasso firmo, cytioplasmate granuloso, fusco-rubro vel puniceo (in evolutionis gradibus quibusdam | 
in colorem viridem mutato). Macrogonidia 2—4—8, rotundata, polo antico rostriformi producta, duo 
cilia longissima gerentia, nucleo centrali rubro, globulis amylaceis 4~6, non semper visibilibus 
instructa, tegumento amplissimo hyalino plerumque ovoideo vestita. Microgonidia multo minora, 
numerosa, luteola vel sordide viridia, apice rubella, ciliis binis instructa, intra tegumentum matri- 
cali alacriter vacillantia, denique membrane ruptura elabentia. (R.) 


Cells globose, or subglobose (4-8 conjoined in a very fugitive ccenobium), cytioderm thickish, 
firm, cytioplasm granular, brownish-red or puniceus, in certain stages of evolution changed into 
green, Macrogonidia 2-4-8, rounded, the frond end bearing very long cilia, furnished with a 
central reddish nuclei and with four to six, not always perceptible, starch granules, clothed with a 
yery ample, hyaline, mostly ovoidal tegument. Microgonidia much the smaller, numerous, luteolous 
or-sordid green, the apex reddish, furnished with two cilia, moving actively within the maternal 
‘egument, and at last escaping by the rupture of the membrane. ~ 


Ch. nivalis (Bauer, Ac.). A. Braun. 
Ch. globulis, 0.004”—0.00135”. (R.) 
Hab.—In nive externa, Greenland. Rocky Mountains. 
Syn.—Ch. nivalis (Baur, Aa.). A. BRAUN. Rasenuorst, Flora Europ. Algarum, Sect. IIT. 
p. 97. 
Globules, 0.004”—0.00135” in diameter. 


Remarks.—I have never seen any good specimens of this plant, merely some 
cells mounted in Canada balsam, and therefore ruined for scientific study, which 
had been collected by Dr. Kane in one of his Arctic voyages. I have also had 
some indications of plants in a little parcel sent me by Mr. Sereno Watson, who 
informs me he has seen the red snow very abundant in the higher peaks of the 
Rocky Mountains. It is a matter of presumption rather than determination, there- 
fore, that the species is identical with the European. 


Genus VOLVOX, Eure. 


Coenobium exacte sphericum, continuo rotatum et agitatum, globum cavum quasi fingens, e cel- 
lulis numerossissimis squali distantia peripherice dispositis, gelatina matricali connexis, puncto 
rubro laterali, locellis (vacuolis) binis contractibilibus necnon ciliis binis longe exsertis instructis, 
vesica communi hyalina cireumcinctis compositum. 


100 FRESH-WATER ALG& OF THE UNITED STATES. 


Propagatio duplex ist, aut non sexualis aut sexualis; illa fit cellulis quibusdam certa distantia 
intumescentibs, multipartitis, in cenobia filialia intra ceenobium matricale evolutis, postea libere 
erumpentibus; hc cellulis masculis multipartitis in fasciculos spermatozoideorum mobilium, con- 
tractilium, pyriformium, ciliis binis instructorum, postea liberorum evolutis ; cellulis femineis intu- 
mescentibus, non divisis, sed post feecundationem in oosporas immobiles episporio duplici circum- 
datas postremo rubras evolutis. (R.) 


Coenobium exactly spherical, continually rotating and agitated, looking like a hollow globe, 
composed of very numerous cells, which are arranged on the periphery at equal distances, and are 
connected by the maternal jelly, and surrounded by a common hyaline bladder; they are also fur- 
nished with a lateral red point, with two contractile vacuoles, as well as two long exserted cilia. 

The propagation is both sexual and non-sexual. In the latter, certain distant cells enlarge greatly, 
divide into numerous parts, and evolve within the parent ceenobium daughter-ccenobia, which are 
finally set free. In the sexual propagation certain molecular cells undergo a multipartite division 
into fasciculi of spermatozoids, which are motile, contractile, pyriform, and furnished with two 
cilia; the feminine cells are enlarged, and do not undergo division, but after fecundation develop into 
immovable oospores, which are finally red, and are surrounded by a double episporium or coat. 


'V. globator, (Liny.) Exes. 

V. conobiis majoribus ad 2’”, cellulis numerossissimis (ad 12,000); ccenobiis filialibus semper 
octo intra matricale fructificatione non sexuali evolutis; fructificatione dioica; ecenobiis 
masculis fasciculos spermatozoideorum numerosos rubescentes foventibus (= Spherosira 
volvox, Ehrb.); ccenobiis femineis cellulas sexuales (oogonia) 20-40 post foecundationem in 
totidem oosporas globosas rubras episporio hyalino stellato circumdatas foventibus. (= Vol- 
vox stellatus, Ehrb.). (R.) , 


Syn.—J. globator, (Linné,) Eurp. Rasennorst, Flora Europ. Algarum, Sect. III. p. 97. 
Hab.—In stagnis. United States. 


Larger cenobium, about 4” in diameter, composed of very numerous (about 12,000) daughter- 
ceenobia, always 8 within the maternal one, evolved without sexuality; fructification dix- 
cious; male cenobium giving origin to numerous reddish spermatozoids (= Spherosphera 
Volvox, Ehrb.); female ccenobium, giving origin to from 20-40 sexual cells, which, after 
fecundation, develop into the same number of globose red oospores surrounded by a stellate 
hyaline episporium. 


Remarks.—Some of my friends tell me they have found this species abundantly 
around Philadelphia. I have not been so fortunate, and have seen but a few 


scattered specimens, which have afforded no opportunity of studying their deve- 
lopment and life-history. 


Orpen Zygophycex. 


Alge aut uni- aut pseudomulti-cellulares, sine vegetatione terminali et ramificatione vera. Cellule 
singule aut geminate aut seriatim conjuncte. Multiplicatio fit cellularum divisione in unam direc- 
tionem, 

Propagatio fit zygosporis conjugatione cellularum similium binarum ortis. 


Alge either uni- or pseudomulti-cellular, without terminal growth or true branches. Cells segre- 


gate or geminate, or arranged in a single row. Multiplication taking place by a division of the 
cells in one direction. 


Propagation by zygospores, formed by the conjugation of two similar cells. 


Famity DESMIDIACEA. 


Alge unicellulares, sine ramificatione vel vegetatione terminali. Cellule forma admodum varia 
plerumque in medio plus minus profunde constrict et in duas semicellulas symmetricas divise, 


FRESH-WATER ALG# OF THE UNITED STATES. 101 


libers vel in fascias filifcrmes aut teniiformes arcte conjuncte aut in muco matricali nidulantes et 
in familias indefinitas consociatw, Cytioderma non siliceum, plus minus firmum, leve aut varie 


asperatum (striatum, costatum, aculeatum, &c.). Massa chlorophyllacea in laminales axiles vel. 
parietales, seepe e centro radiantes, distributa, 


Propagatio non sexualis per divisione transversa in eandem directionem repetita ; sexualis per 
zygosporas, que per cellularum binarum conjugationem oriuntur. 


Unicellular algz, without branches or terminal growth. Cells of very various forms, mostly more 
or less profoundly constricted in the middle and divided into two symmetrical semicells, free or con- 
joined in filiform or teniform fascia, or involved in the maternal jelly so as to form indefinite fami- 
lies. Cytioderm not siliceous, more or less firm, smooth, or variously roughened (striate, costate, 


aculeate, &c.) Chlorophyl masses in axillary or parietal lamina, which often radiate from the 
centre. 


Non-sexual propagation by repeated transverse division in one direction ; sexual by zygospores 
which are formed by the conjugation of two cells. 


Remarks,—Of all the fresh-water alge, with the exception of the diatoms, this. 
family has attracted most attention, owing, not only to the beauty and variety of 
its forms, but also to their universal presence and abundance, and the ease with 
which their most wonderful life-histories are observed. ‘They are exclusively, as 
far as known, denizens of fresh-water, and preferably that which is pure and limpid. 
Although Mr. Ralfs states that they never grow in stagnant water, I have often 
found them in great abundance in such, yet never in that which was actually putrid. 
The same authority is also too sweeping, at least as far as this country is concerned, 
in stating they are never found in woods, although they are really most abundant 
in the open country. My experience has taught me to look for them in brick- 
ponds, small mountain lakes, springy fens, ditches, and, in the fall, growing among 
mosses and in the thick jelly composed of unicellular alge on the face of drip- 
ping rocks, or, to sum up in a word, they dwell in quiet, shallow waters, for I have 
never found them in rapidly moving or very deep water. 

The single cell, of which a desmid is composed, is mostly divided into two very 
marked similar portions, the exact ‘counterparts one of the other, which by some 
have been asserted to be distinct cells. Their close union and connection, and their 
inherent oneness are, however, so apparent that it is needless here to spend time 
in demonstrating that they really are halves of one individual cell. They contain 
together all the parts found in the typical vegetable cell; an outer cellulose wall, 
chlorophyllous protoplasm, a nucleus, starch granules and semiliquid contents, 
The cell-wall, or cytioderm, as it is called in this memoir, varies in thickness 
and firmness. During life it is mostly, if not always, colorless i but in certain 
species in the dead empty frond is of a reddish-yellow. The markings upon it are 
various, and are not infrequently altogether absent; they are such as fine or coarse 
punctations, granulations of various size, striee, furrows or elevated ribs, tuber- 
cles, obtuse or sharp simple or forked spines, hair-like processes, umbonations, &e. 
&c. These markings are within narrow limits constant in each species, and 
more or less peculiar, so that they afford valuable characters to the systematist. 
The cytioderm itself is mostly composed of cellulose free from appreciable nor 
ganic matters, but in certain species contains a large amount of silex. ‘Thus, 


102 FRESH-WATER ALG OF THE UNITED STATES. 


according to De Barry, if Closterinm lunula be carefully burnt upon a slide, a per- 
fect hyaline silex cast of the cells is left. 

The chlorophyl is variously placed in the cell, sometimes it is arranged in 
lamina, sometimes in spirals, sometimes in the form of radii from a central mass, 
These different methods afford good generic characters, and will be dwelt upon 
more in detail under the various genera. The color of the chlorophyl during 
active life is a vivid green, which, as the vital forces lessen, changes to a faded 
yellowish tint. 

Negeli and others affirm that there is always a central nucleus in the desmid, 
and probably do so with truth, although in many instances I have found it impos- 
sible to demonstrate its presence from the size and opaqueness of the frond, 
crowded with endochrome, &c. In a large number of cases, however, it is very 
apparent. 

As ordinarily viewed under the microscope the two most striking peculiarities 
presented by these little plants are the motion of the whole desmid in the water 
and the various movements exhibited within the fronds. The general movement 
is most apparent in the larger species, which exist free and distinct in the water, 
especially in the boat-shape closteria. It mostly consists of a steady, stately, 
slow onward movement, with sometimes backward vscillations. By virtue of it, 
desmids in a bottle will often congregate in such positions as are most exposed to 
light. ‘There have been various theories advanced as to the cause of this motion. 
Ehrenberg believed that he had found foot-like processes protruding from the end 
of the frond and giving the motile power. Others, such as Rev. Mr. Osborne and 
Mr. Jabez Hogg, have attributed the movements to the presence of cilia, but I 
think have failed so entirely to establish this that their views are more than pro- 
blematical. That the motion is due to vital actions, taking place especially under 
the action of light, is as much as can be at present affirmed with any certainty, though 
it is probable that the immediate agents are endosmotic currents of gas or water. 

The movements of the contents within the cells are chiefly of two kinds. Tak- 
ing Closterium lunula as an illustrative example, there will be found on ex- 
amination with an {th objective, a narrow, very transparent, and therefore 
often not very apparent layer or zone lying immediately within the cell- 
wall, between it and the endochrome, and dipping inward in the middle of the 
frond so as to communicate with the nucleus. In this zone are protoplasm, 
watery fluid, and scattered granules. In the ends of the fronds the different por- 
tions of this zone, meeting and widening, fill up the whole of the cavity, and within 
the space thus occupied by them, there is a glopular, sharply defined, still more 
transparent vacuole. ‘This, some have thought to be a closed sac, with a distinct 
wall, but it seems really to be a vacuole lying in the midst of the inner protoplasm, 
which with a few granules occupies more or less completely the transparent zone 
already described. Sometimes the chlorophyl encroaches upon this zone at the 
ends so as to more or less completely surround the vacuole, within which are always 
found watery fluid and granules. In the protoplasmic zone and its vacuole active 
movements are probably always present during active life. Streams of protoplasm 
appear to be constantly passing to and fro between the nucleus and the ends of 


FRESH-WATER ALG OF THE UNITED STATES. 103 


the cell along the outer zone, and granules can be always seen passing backwards 
and forwards with an unsteady motion. 

When the streams of protoplasm are setting very actively from the centre to- 
wards one end, there will often be an accumulation of the protoplasm there, and a 
consequent decided lessening in the size of the vacuole, which will again expand 
as the return currents arouse themselves. Within the vacuoles are seen more 
or less numerous smaller or larger granules in active busy motion, swarming over 
and about one another with an unsteady hurrying to and fro. 

A form of motion, similar in appearance to this, but probably of different signi- 
ficance, is seen in most desmids when in an unhealthy feeble condition. I 
have seen it most marked in Cosmarium margaritaceum. In such fronds the endo- 
chrome has lost its deep green color, and become shrunken, and lying within it is 
a great space containing myriads of minute blackish particles swarming about 
actively. ‘This peculiar state and appearance is by no means confined to the 
desmids, for I have seen it very highly developed both in species of Spirogyra and 
Cidogonium. It appears to be connected with decay. Is it possible that these 
minute particles are foreign to the plant, vibrionic in nature? 

In regard to the nature of the movements seen within a healthy desmid, some 
have viewed them as exceedingly mysterious, the result of the presence of 


cilia, &c.; but these views have been so thoroughly exploded that it is scarcely 
necessary even to mention them here. The movements are, in truth, precisely 


parallel to the so-called cyclosis of the higher plants. Protoplasmic germinal mat- 
ter, wherever it exists, be it in animal or vegetable, has as one of its distinguish- 
ing characters the power of active, spontaneous, apparently causeless movements, 
and it is simply the carrying out of this power or attribute which has attracted so 
much attention in the desmids, because it is in them so readily seen. 

There are, in this family, two distinct methods in which the species are multiplied 
one with, the other without, the intervention of anything like sexuality. The 
non-sexual method of increase is really a modification of an ordinary vegetative 
process, a peculiar cell multiplication by division. In such fronds as those of the 
genus Cosmarium, which are composed of two evident halves connected by a 
longer or shorter isthmus, the first step in the process is an elongation of this neck. 
In a very short time there appears around the centre of this a constriction, and I 
believe an actual rupture of the outer coat. By this time a new wall has formed 
inside each half of the isthmus, and stretches also across its cavity, forming with 
its fellow a double partition wall, separating the two halves of the old frond. 
Rapid growth of the newly formed parts now takes place, the central ends become 
more and more bulging as they enlarge, and in a little time two miniature lobules 
have shaped themselves at the position of the old isthmus. These are at first 
small, colorless, and destitute of all markings, looking, as Mr. Ralfs says, like con- 
densed gelatine. They, however, rapidly increase in size and firmness, their con- 
tents assuming a green color and their walls taking on the peculiar markings of 
the species. At last, the parts thus formed having assumed the shape and appear- 
ance of the original lobules, the two fronds, which have been developed out of one, 
separate, mostly before the new semicells have acquired their full size. 


104 FRESH-WATER ALG# OF THE UNITED STATES. 


What part the nucleus has in the process just described I have never actually 
demonstrated, but have little doubt but that it undergoes a division in the very 
commencement, so that the new nucleus of each secondary frond is formed out of 
one-half of the old one. 

In proportion as the form of the desmid becomes simpler, so do the peculiarities 
of its cell multiplication become less. In those species which are simple cylindri- 
cal cells, there appears to be nothing peculiar in the method of dividing, which, 
however, always takes place through the centre of the cell, and subsequent growth 
occurs, generally, only in the newly formed part. 

True sexual reproduction apparently does not take place as freely in this family 
as the former process, for whilst I have seen hundreds of cells undergoing the 
latter, it has not been my good fortune to meet with conjugating specimens on 
more than two or three occasions. 

The process has, however, been studied very closely by De Bary, Braun, Hof 
meister, and others, and appears to consist generally in a rupture of the outer wall 
of two cells and the protrusion of delicate processes from an inner, often newly 
formed coat, with subsequent union of these, and consequently of the two cells, 
and afterwards a condensation of the contents in the enlarged connecting passage. 
The connecting passage between the fronds is really a sporangium in which the 
spore is perfected, the contents of the cells finally condensing it into a firm globe 
and secreting around themselves a thick coat. 

The after-history of this spore has been very successfully studied by M. Hof- 
meister, whose observations were made upon Cosmarium tetraophthalmum, which 
he watched conjugating and forming a sort of resting spore which was perfected 
early in the month of July. This was composed of a thick outer coat and green 
endochrome lying within as a distinct ball, nowhere in contact with the invest- 
ing membranes. In three weeks’ time this chlorophyllous protoplasm had divided 
into ellipsoidal masses, or primordial cells, which soon surrounded themselves with 
cellulose walls and became distinct free cells in the granular fluid which filled the 
cavity of the original spore. In August, each of these masses was divided into two 
and in the month of September the process was repeated, so that out of the original 
endochrome eight strongly flattened primordial cells were produced. Division in 
some specimens ceased here, and in others took place once more, so that by the fol- 
lowing spring all of the living Sporangia contained eight or sixteen green daughter- 
cells, each of them discoid in outline with a strongly marked central notch. 
These daughter-cells were finally set free by the solution of the spore wall, as Cos- 
maria of minute size, but agreeing in all other characters with the specific form to 
which they belonged. 

According to Braun, in the larger, more or less lunate Closteria, conjugation 
occurs in the following method: Two fronds approach one another in such a way 
that they lie back to back. In the middle of each of them, there then appears an 
annular line or trench reaching through the cell wall, and accompanied by a dis- 
tinct separation of the endochrome into two halves. Whilst these changes have 
been progressing there has also formed a new double wall at the position of the 
trench, so that out of the two Closteria two pairs of separate equal cells have been 


FRESH-WATER ALGA OF THE UNITED STATES. 105 


formed. Near to the larger or central end of each of these now appears a pouting 
transparent nipple-like process, The corresponding opposing processes enlarging 
and meeting coalesce, so that the upper half of one closterium, in the form of a 
daughter-cell, is finally united with the upper half of the other closterium, and the 
two lower halves are also joined together. Thus from a single pair of fronds arise 
two conjugating pairs of cells, and finally two sporangia, in each of which a spore 
is perfected. 

This process does not seem, however, to be universal amidst the Closteria, for 
in many, if not all, of the smaller species, a pair of fronds produces a single spo- 
rangium. 

In the genus Palmogloea, in which I have had an opportunity to study the devel- 
opment of the spores, the process closely simulates that seen in certain of the 
Spirogyra. The contents of the cells first became broken up and confused, and 
almost simultaneously the nucleus disappeared (fig. 4, pl. 11) the cells became 
swollen at one side and slightly bent backward so as to form jutting processes, 
which meeting grew together, became confluent and developed into a sporangium 
much larger than either of the parent cells. Into this sporangium the contents of 
the latter passed and soon became converted into a thick-walled spore (fig. 00, pl. 
00) often completely filling the cavity, and apparently with its wall adherent to that 
of the latter. 


Genus PALMOGLGA, Krz. (1848). 


Cellule oblong, elliptic: vel cylindrice, utroque polo rotundate, medio non constricte, plerumque 
in muco gelatinoso nidulantes, liber, singule vel in familias consociate, lamina chlorophyllacea 
axili vel excentrica, etate provecta medio constricta, denique divisa praedite. (R.) 

Syn.—Wesotenium, N 2GELI. 


Cell oblong, elliptical or cylindrical, rounded at each end, not constricted in the middle, mostly 
swimming in a gelatinous mucus, free, single or associated in families, chlorophyl lamina axillary 
or excentric, in the early state constricted, and at length divided in the middle 


Remarks.—The above diagnosis of the genus is that given by Prof. Rabenhorst, 
and agrees essentially with that of De Bary, Negeli, &c. In the species herein 
described however, the axillary lamina of chlorophyl were not so pronounced, for 
the green coloring matter seemed often to surround the cavity of the cell, and in 
other specimens was broken up and diffused through it. 


P. clepsydra, Woop. 
P. saxicola et bryophila, in gelatina achroa interdum dilute viride nidulans; cellulis cylindricis, 


cum polis obtuse truncato-rotundatis, diametro 2-3 plo longioribus; lamina chlorophyllacea 
axili, plerumque indistincte, sepe nulla; plasmate dilute viride; nucleo plerumque distincto; 
zygosporis subfuscis aut subglobosis aut enormiter in clepsydre forma; membrana externa 
enormiter excavata et sulcata. 

Diam.—7135". 

Syn.—P. clepsydra, Woop, Prodromus, Proc. Amer. Philosophical Soe. 1869, 


Hab.—In rupibus et in muscis irroratis ad Chelten Hills, prope Philadelphia. 
14 June, 1872, 


106 FRESH-WATER ALG& OF THE UNITED STATES. 


P. living on rocks and mosses, swimming in a transparent, sometimes light-green jelly; cells 
obtusely truncated, rounded at the ends, 2-3 times longer than broad; chlorophyl lamina 
axillary, mostly indistinct, often wanting ; endochrome light-green; nucleus generally distinct ; 
zygospore subfuscous, either globose or of an irregular form, somewhat resembling that of an 


hour-glass; external coat irregularly excavated and sulcate. 


Remarks.—This species was found along the North Pennsylvania Railroad, near 
Chelten Hills, growing amid mosses on the rocky juttings over which the water 
was dripping. It occurs as a rather firm, transparent jelly, mostly of a light 
greenish tint, in which the cells are often placed quite thickly. They are cylin- 
drical, mostly straight, but sometimes slightly curved, and often completely filled 
with a light greenish endochrome. The central lamina is irregular, and mostly 
not at all pronounced. In some cells the endochrome is much broken up, so that 
the interior is filled with little green masses with light spaces between them. In 
these cells the nucleus is generally not perceptible, whilst in the others it is very 
well marked. The zygospore is often globular, sometimes it is irregularly elliptical, 
with a constriction in the centre, so as to give it somewhat of an hour-glass shape. 
The outer coat mostly fits pretty closely on the inner contents, and is very often 
distinctly marked with little pits, some round, some irregular in shape; in other 
cases, instead of being thus pitted, the spores seem to be marked with deep curved 
furrows. 

Fig. 4, pl. 11, represents this plant in different stages of growth. (See Eayle 
nation of Plates.) 


Genus PENIUM, Bris. (1848.) 


Cellule cylindrice vel fusiformes, rectz, utroque polo rotundate vel truncato-rotundate (nec emar- 
ginate nec excise), medio sepius constrict. Lamina chlorophyllacea axilis, ex transverso conspecta 
radiatim-divergens, radii sepe furcati, granula amylacea plerumque longitudinaliter seriata includens. 
Individua in aqua libere natantia, singula, sparsa vel in massa gelatinosa consociata. Cellule mem- 
brana levis vel granulata, achroa vel fuscescens vel rubicunda, sepius longitudinaliter striata. (R.) 


Syn.—Netrium, N mgExt. 
Cylindrocystis, MENGH. 
Closterium, partim, EHRENBERG. 


Cells cylindrical or fusiform, straight, rounded at each end, or truncately rounded (not emarginate 
or excised), medianly often constricted. Chlorophyl lamina axillary, when seen transversely radi- 
ately divergent, arms often forked, and containing starch granules, mostly longitudinally striate. 
Individuals swimming free in the water, scattered and single, or associated in gelatinous masses. 
Cell membranes smooth or granulate, transparent or fuscous or reddish, often longitudinally striate. 

a, Lamina chlorophyllacea peripherice lobata vel radiatim expansa. 


a, Chlorophyl lamina, lobate.on the periphery or radiately expanded. 


P. Digitus, (Eurs.) Brés, 
P. cellulis ovato-cylindricis, diametro 3-5 plo longioribus, utroque polo parum attenuatis, sub- 
truncato-rotundatis; laminis chlorophyllaceis peripherice lobatis, medio interruptis. 


Diam.—7}35" = .00173”—7225” = .0029". 
’ Syn.—P. Digitus, (Enrs.) Brés. Rapennorst, Flora Europ. Algar., Sect. III. p- 118. 


Cells ovately cylindrical, 3-5 times as long as broad, at each end slightly attenuate, subtrun. 
cately rounded; chlorophy] lamina lobate on the periphery, interrupted in the middle, 


FRESH-WATER ALG# OF THE UNITED STATES. 107 


Remarks.—This species is probably widely diffused through the temperate por- 
tions of North America. I have found it abundantly near Philadelphia, as well as 
among the Alleghanies, and have received specimens from Dr. Lewis, collected in 
Saco Lake, Northern New York; Prof. Bailey also notes it as occurring in Georgia. 
There is one form of it which resembles somewhat in outline the modern coffin, 
one end being much broader and much more rapidly narrowed than the other. 
There is no distinct vacuole at the end, at least in any specimen I remember to 
have seen, although frequently large numbers of moving granules can be detected 
in that portion of the frond. 

Fig. 6, pl. 20, represents the outline of a frond of this species. 


P. lamellosum, Brés. 
P. cellulis oblongo- vel fusiformi-cylindricis, diametro 5-6 plo longioribus, medio sepe leviter 
constrictis, utroque polo magis attenuatis, obtuso rotundatis. (It.) 


Diam.—0.0023"”—0.0029". (R.) 
Syn.—P. lamellosum, Brés. RaBENHORST, Flora Europ. Algarum, Sect. III. p. 118. 
Hab.—Rhode Island. (Olney) Thwaites. 


Cells oblong or fusiform cylindrical, 5-6 times. longer than broad, often slightly constricted in 
the centre, more attenuate at the ends, obtusely rounded. 


Remarks.—I have never recognized this species, but it is one of those sent over 
by Mr. Olney, and identified by Prof. Thwaites. 


b. Lamina chlorophyllacea integerrima. 
b. Chlorophyl lamina entire. 
* Cellule in medio plus minus constricte. 


* Cells more or less constricted in the middle. 


P. margaritaceum, Exes. 
P. elongato cylindricum, diametro 8-9 plo longius, medio plerumque leviter constrictum, utroque 
polo rotundato-truncatum ; cellule membrana nodulis seriatis quasi margaritacea; locellus 
in medio (circiter) utriusque cruris corpusculis mobilibus in mure Closteriorum repletus. (R.) 
Diam.—0.00098"”—0.0011". (R.) 
Hab.—Rhbode Island. (Olney) Thwaites; Bailey. Florida. Bailey. 


Elongate cylindrical, 8-9 times longer than broad, in the centre generally slightly constricted, 
at each end roundly truncate ; membrane of the cells somewhat pearly with seriate granules ; 
vacuole about in the centre of each crus, filled with moving granules, as in closterium. 


Remarks.—I have not seen this desmid, but it is in Prof. Bailey’s list; it was 
also among those sent by Mr. Olney to Prof. Thwaites. 
P. minutum, CLEVE. 
P. cylindricum, gracile, diametro 5-7 plo longius, leve, ad polos obtusissimos (latissime rotun- 
datos) parum attenuatum, medio leviter constrictum. (R.) Species mihi ignota. 
Diam.—0,00044”—0.00063”. (R.) 


Syn.—Docidium minutum, Raur’s British Desmid. 
P. minutum, Cievs. Rasenuorst, Flora Europ. Algarum, Sect. III. p. 123. 


108 FRESH-WATER ALG OF THE UNITED STATES. 


Hab.—South Carolina; Florida. Bailey. “Rhode Island. (S. T. Olney) Thwaites. 

Frond slender, suture not prominent; segments four to six times longer than broad, somewhat 
tapering, inflation obsolete, sides straight, ends entire; e. f. without puncture. L. s}3"5 
B. gesy". (Archer.) 


b. Cellulee in medio non constrictz. 


b. Cells not constricted in the middle. 


P. interruptum, Brés. 

“P. cellulis late lineari-cylindricis, diametro 5-6 plo longioribus, utroque polo subito cuneato- 
acutatis, apicibus obtuso-rotundatis; laminis chlorophyllaceis longitudinalibus saturate viridi- 
bus, zetate provecta fasciis transversis tribus pallidis interruptis.” (R.) Species mihi ignota. 

Diam.-0.00147”’—0.00177”". (R.) 

Syn.—P. interruptum, Bris. RaBENHOoRST, Flora Europ. Algarum, Sect. ITI. p. 119. 

Hab.—In fossis, South Carolina, prope Grahamsville. Prof. Bailey. 


Cells broadly linearly cylindrical, 5-6 times longer than broad, at each end suddenly cuneately 
sharpened, the apex obtusely rounded; longitudinal chlorophyl lamina deep green, in ad- 
vanced age interrupted by three transverse pale fascia. 


P. Jenneri, Ratrs. 

P. ab P. Brebissonii vix discernendum, cellulis cylindricis, utroque polo rotundatis, levibus, dia- 
metro 23-5 plo longioribus; zygosporis plerumque globosis, membrana fuscescente subgranu- 
lata. (R.) Species mihi ignota. 

Diam.—0.00057”—0.0006”. (R.) 

Syn.—P. Jenneri, Raurs. RaBenworst, Flora Europ. Algarum, Sect. III. p. 120. 

Hab.—In fossis, Florida. Prof. Bailey. 


Scarcely distinguishable from P. Brébissonii, cells cylindrical, rounded at each end, smooth, 
23-5 times longer than broad ; zygospores mostly globose, membrane somewhat fuscous, sub- 
granulate. 


P. Brébissonii, (Menez.) Rates. \ 
P. in massa mucosa indefinite expansa sepe cum algis alteris intermixtis; cellulis perfecte 
cylindricis, interdum nonnibil curvatis sed plerumque rectis, diametro 23-4 plo longioribus, 
utroque polo late rotundatis, in medio non constrictis; “ zygosporis angularibus vel rotundatis, 
membrana fuscente, subtiliter granulata.” : 
Diam.—7z55" = .00066”. 


Syn.—P. Brébissonii, (MENGH.) Ratrs. Rasennorst, Flora Europ. Algarum, Sect. III. Pp. 
120. 


Hab.—In fossis, South Carolina. (Prof. Ravenel.) 


In an indefinitely expanded mucous mass, intermixed with other alge; cells perfectly cylindri- 
cal, sometimes slightly curved, but generally straight, at each end broadly rounded, not con- 
stricted in the middle; “zygospores angular or rounded, membrane fuscous, finely granu- 
late.” 


Remarks.—Among the numerous desmids which I have received from Prof. 
Ravenel are some which, I think, must be referred to P. Brebissonii, although they 
do not nearly equal the size of the European form, nor even the diameter given 
above, which is almost the lowest limit of the mature foreign plant. I believe 
however, Prof. Ravenel’s specimens are immature, a 


FRESH-WATER ALG# OF THE UNTEID STATES. 109 


Mr. Ralfs’ description of the conjugation is as follows: The process of the con- 
jugation in this species differs from that in the rest of this genus; for, as in Hya- 
lotheca dissiliens, the conjugation cells enter into the formation of the containing 
cell and are permanently attached to the sporangium, instead of being detached, 
as commonly happens, in the Desmids. The sporangium is at first cruciform, then 
quadrate, and finally orbicular. 


P. closterioides, Ratrs. 

P. cellulis anguste lanceolatis, diametro maximo 5-6 plo longioribus, a medio in apices subtrun- 
cato-rotundatos sensim attenuatis; laminis chlorophyll. saturate viridibus, medio fascia trans- 
versa pallida interruptis. (R.) Species mihi ignota. 

Diam.—0.00159"”—0.00175". (R.) 

Syn.—P. closterioides, Ratrs. RaBenuHorst, Flora Europ. Algarum, Sect. III. p. 121. 

Hab.—Prope Grahamsville, South Carolina. Prof. Bailey. 

Cells narrowly lanceolate, 5~6 times longer than the greatest diameter, sensibly attenuate from 


the middle into the subtruncate apices; chlorophyl lamina deep green, interrupted by a median 
pale band. 


Genus CLOSTERIUM, Nirtscu. 


Cellule interdum cylindrice sed sepius fusiformes et utroque polo attenuate, plus minus lunula- 
tim curvate, in medio haud constricte sed stria transversa unica vel 2-5 impresse. Cytioderma 
tenue, sat firmum, lave vel plus minus distincte striatum et interdum longitudinaliter costatum. 
Cytioplasma chlorophyllosa plerumque in laminis longitudinalibus disposita, et sub cellule polis 
locello achroo, plerumque globoso et corpusculis plus minus numerosis se vivide moventibus impleto 
instructa. 

Cells sometimes cylindrical, but more often fusiform and attenuate at each end, more or less 
lunately curved, in the centre not constricted but marked with from 1-5 transverse strie. Cytioderm 
thin, moderately firm, smooth or more or less distinctly striate, and sometimes longitudinally costate. 
Chlorophyllous cytioplasm mostly arranged in longitudinal lamina, and furnished at each end with a 
clear space, which is mostly globose, and contains more or less numerous actively moving corpuscles. 


a. Zygospore globose, rarissime angulares ; cellule crura aut non aut minus producta. 
a. Zygospores globose, very rarely angular ; crura of the cells not at all, or only slightly, pro- 
duced. 
. Cellule cylindrice, ad utrumque polum vie vel paullum attenuate, rectz vel leviter curvate, 
apicibus rotundatis vel truncatis. 
1. Cells cylindrical, not at all or but slightly attenuated at the ends, straight or slightly 
curved, the apex rounded or truncate. 


a 


C. striolatum, Eze. 

C. anguste lanceolato-fusiforme, leviter arcuatum, 8-12 plo fere longius quam latum, utroque 
polo paulum sensimque attenuatum, apicibus truncatis sepe fuscescentibus ; membrana dis- 
tinctissime striata, vacuata fuscescente; vesiculis chlorophyllaceis 5-7 (in quoque crure); 
locello apices versus sito, submagno, corpuscula 12-20 includente. (R.) 

Diam.—7z5”—gs"" = 0.00152" —0.00187". (B.) 

Syn.—C. striolatum, Burs. Rasenuorst, Flora Europ. Algarum, Sect. IIT. p. 125. 

Hab.—In aquis quietis, Centre County, Pennsylvania. Wood. Saco Pond, New Hampshire. 

(Lewis) 
Narrowly lanceolately-fusiform, slightly bent, 8-12 times longer than broad, sensibly attenuated 


110 FRESH-WATER ALG& OF THE UNITED STATES. 


at the ends, which are truncate and often somewhat fuscous ; membrane very distinctly striate, 
when empty somewhat fuscous; chlorophyl globules 5-7 (in each limb); vacuole placed in . 
the bent apex, moderately large, including 12-20 corpuscles. 


Remarks.—The measurements given are those of Prof. Rabenhorst. Our Ame- 
rican forms agree well with them. 


Cc. angustatum, K1z. 

C. gracile, sublineare, diametro 16-18 plo longius, ad polos levissime attenuatum, apicibus late 
truncatis; costis longitudinalibus paullulum prominulis 4-5, interstitiis circiter z}y’” latis; 
vesiculis chlorophyllaceis in quoque cruro 6-7; locello ab apice subremoto mediocri, corpus- 
culis 12-20 impleto. (R.) 

Diam.—yzhy"—se" = 0.00081” —0.0010". (R.) 

Syn.— CO. angustatum, Krz. Rasennorst, Flora Europ. Algarum, Sect. ITI. p. 126. 

Hab.—In aquis quietis, prope Philadelphia, Pennsylvania. Wood. Rhode Island. Bailey. 

New Hampshire. (Lewis) 


C. slender, sublinear, 16-18 times longer than broad, very slightly attenuate at the ends, which 
are broadly truncate; with from 4-5 somewhat prominent longitudinal ribs, the interstices 
about z1,”” broad; chlorophyl globules in each limb 6-7; vesicle subremote from the apex, 
moderate, containing from 12-20 corpuscles. 


Cc, juncidum, Ratrs. 
C. elongatum, anguste lineare, diametro 20-35 plo longius, leviter arcuatum, utroque polo vix 
attenuatum; apicibus truncatis; cytiodermate luteolo, interdum longitudinaliter striato. 
Diam.—yz2oy" = .0004". 
Syn.—C. juncidum, Raurs. RaxBenworst, Flora Europ. Algarum, Sect. III. p. 12'7. 
Hab.—In fossis, South Carolina. (Ravenel) In lacu Saco, New Hampshire. (Lewis) 


Elongate, narrowly linear, 20-35 longer than broad, slightly bent, scarcely narrowed at the 
ends; apices truncate; cytioderm yellowish-brown, sometimes longitudinally striate. 


Remarks.—I am indebted to Prof. Ravenel for specimens of this species, by 
whom they were found on the slimy surface of a half dried-up ditch, associated 
with numerous other desmids. ‘he specimens are all smaller than the measure- 
ments of Rabenhorst, but much larger than those given by Mr. Ralfs. None of 
the plants have any chlorophyl granules—a circumstance probably simply depen- 
dent upon the stage of their development. The longitudinal striz are in none of 
the specimens very distinct, and in many cannot be demonstrated. 

Since writing the above I have seen specimens collected by Dr. Lewis in “Saco 
Pond,” near the Crawford House, New Hampshire.. 

Mr. Archer (Pritchard’s Infus., p. 749) lays stress upon the ere being straight 
in the middle, with the ends curved downwards; but I have seen numerous speci- 
mens in which the curve was through the whole length. 

Fig. 20, pl. 12, represents one of the specimens collected by Prof. Ravenel in 
South Carolina. 


. Cellule cylindrice, dorso plus minus convex, ventre subplane, nunquam ventricoso 
— inflate, 


FRESH-WATER ALG&A OF THE UNITED STATES. Ill 


2. Cells cylindrical, with the dorsum more or less convea, the belly straightish, never venirt- 
cosely inflated, 
Cc. Lunula, (Miter) Exes. 

C. permagnum, subleve (strie subtilissime vel indistinct), semilunare, dorso alte convexum, 
ventre subplanum, apicibus attenuatis rotundatis; vesiculis chlorophyllaceis numerosis spar- 
sis; locello distincto subapicali corpuscula numerosa includente. (R.) 

Diam.—3,"—z}5" = 0.00032" —0.0045". (R.) 

Syn.—C.Lunula, (Mituzr,) Furs. Rapennorst, Flora Europ. Algarum, Sect. III. p. 127. 

Hab.—South Carolina, Georgia, Florida. Prof. Bailey. Pennsylvania. Wood. 


Very large, smoothish (strie very fine or indistinct), semilunar, dorsum strongly convex, belly 
straightish, the ends attenuate and rounded; chlorophyl globules numerous, scattered; vesi- 
cle distinct, subapical, including numerous corpuscles. 


C. acerosuma, (Scuzanx) Hugs. 
(Var. nov. maximum.) 

C. lineare-fusiforme, sub-rectum aut leve curvatum, utroque fine sensim et paullulum atten- 
uatum, diametro 15-24 plo longiore; apicibus angustissime truncatis, achrois; membrana 
haud striata; vesiculis chlorophyllaceis 11-14 in quoque crure, in serie axilli simplici collo- 
catis; locello apicali parvo, corpuscula numerosa includente; zygosporis globosis. 

Diam.—Transv. max. 7335” = .0017"; zygosp. 7295" =.0027”. 

Syn.—C. acerosum, (ScHRANK) EurB. Raxpenuorst, Flora Europ. Algarum, Sect. III. p. 

128. 
Hab.—Pennsylvania; Wood. South Carolina, Georgia, Florida; Bailey. 


Linear, fusiform, straightish, or slightly curved, at each end sensibly little by little attenuate, 
15-24 times longer than broad; apices narrowly truncate, transparent; membrane not striate ; 
chlorophyl globules 11-14 in each limb placed in a simple axillary series; apical vesicle 
small, containing numerous corpuscles; zygospores globose. 


Remarks.—The desmid, described above, was found in New Jersey, near Cam- 
den. It differs from the typical form of C. aceroswm in its size, proportionate 
length to breadth, and in not being striate. The European “ formd major” 
(RABENH.) appears, however, to exceed it in transverse diameter, and, according 
to some authors, certain fronds of the species are not striate, and all authorities 
agree that at times the striz are exceedingly delicate. For these reasons, I think, 
our American form must be regarded simply as a variety. As far as can be judged 
from the rude figure, it is this species which Prof. Bailey identifies as C. tenue, 
Krz., in Silliman’s Journal for 1841. 

Fig. 5, and 5 a, pl. 11, represent this species magnified 250 diameters; 5 } 
represents the sporangium with portions of the dead fertile fronds still attached. 


Cc. areolatum, Woon, (sp. nov.) 

C. fusiforme, subrectum vel normihil curvatum, lateris ventralis medio seepe paullulum concavum, 
diametro 9-10 plo longius, utrinque modice attenuatum; apicibus truncato-rotundatis ; mem- 

| brana crassa, et firma, rubido-brunnea, profunde distante striata, et minutissime sed distincte 
granulata vel areolata; suturis medianis distinctissimis 4-10. 


Diam.— 0.0024”. 
Hab.—In aquis puris quietis; Northumberland Co., Pennsylvania. 


112 FRESH-WATER ALG& OF THE UNITED STATES 


Fusiform, straightish, or very slightly curved, the ventral side often a little concave in the 
middle, 9-10 times longer than broad, moderately attenuated at each end; the apices trun- 
cately rounded ; cell-membrane reddish-brown, thick and firm, distantly profoundly striate, 
and very minutely but distinctly granulate or areolate; median sutures very distinct, 
4-10 in number. 


Remarks.—I found this species growing in a quiet pool of pure water, in a wild, 
deeply wooded ravine, near Danville, Central Pennsylvania. It was in great 
abundance, forming a translucent greenish jelly, one or two gills of which might 
have been readily gathered. Unfortunately, I had no microscope with me and 
cannot, therefore, determine at all as to the arrangement of the endochrome, the 
carbolic acid, used as preservative, having entirely disarranged this by the time I 
got the fronds upon a slide. ‘The empty frond is of a reddish-brown color. The 
membrane is quite thick and firm, and is marked with very prominent broad striz 
or grooves. In a number of cases I have counted these and always found nine 
present upon one face of the frond. There are also upon the surface numerous 
minute markings not fairly visible with a lower power than a ;4th objective. 
Under this glass they appear as minute punctations. An eighth resolves them 
into granules mostly of an oblong shape, arranged more or less regularly in longi- 
tudinal rows. Very generally, each side of the stria or groove has a close row of 
larger and more distinct granules forming a sort of border to it. In truth, the 
surface of the frond is covered with broad longitudinal bands of these granules, 
and the narrow smooth spaces between them constitute the stria spoken of. This 
species is very closely allied to C. turgidum, Exrs., agreeing pretty well with it in 
general outline and size. I think, however, the peculiar markings upon the 
membrane are sufficient to separate it, and do not doubt that if fresh specimens 
were at hand, differences would be found to exist also in the arrangement of the 
cell-contents. The turning up of the ends, generally so marked in C. turgidum, 
is mostly entirely absent in this species, rarely there is some tendency fo it. 

Fig. 6, pl. 11, represents in outline a frond magnified 160 diameters; Fig. 6 a, 
the end of an empty cell, magnified 1375 diameters; the color of this is, perhaps, 
a little too dark. : 


C. lineatum, Eure. 


C. valde elongatum, gracile, quater vicies-tricies longius quam latum, distincte striatum, e 
medio recto cylindrico utrinque valde attenuatum, apices versus leviter incurvum, obtuso- 
truncatum; vesiculis chlorophyllaceis in quoque crure 20-21, in seriem unicam axilem dis- 
tributis ; locello parvo, ab apice remoto, corpusculis 10-12 impleto. (R.) 


Diam.—zi55" = .0015”. 
Syn.—C. lineatum, Exrs. Razenuorst, Flora Europ. Algarum, Sect. IIT. p. 130. 
Hab.—Pennsylvania, Wood. 


Very much elongate, slender, distinctly striate, from the centre straight and cylindrical, at each 
end very greatly attenuate, apex bent, slightly incurved, obtusely truncate; chlorophyl glo- 
bules 20-21 in each limb, placed in a simple axillary series; vacuole small, remote from the 
apex, containing from 10-12 corpuscles. 


Remarks.—The American forms agree well with the above description ; some 


FRESH-WATER ALGD OF THE UNITED STATES. 113 


of them, however, are a little more curved in the central portion than it would 
imply. 
Fig. 1, pl. 12, is a drawing of an American plant, magnified 160 diameters. 


Cc. Cucumis, Exzs. 
C. oblongum, turgidum, leviter curvum, leve, diametro 4-7 plo longius, apicibus obtusis. (R.) 
Syn.—C, Cucumis, Hurensera, Verbreit. b. 28, 1V. F.28. Rapenuorst, Flora Europ. Alga- 
rum, Sect. III. p. 138. 
Hab.—New York; Ehrenberg. 


Oblong, turgid, slightly curved, smooth, 4-7 times longer than broad, the apex obtuse. 


Remarks.—I have no knowledge of this species other than that in the above 
short description, which has been copied frota Rabenhorst’s works. 


3. Cellule semilunares, plerumque magis curvatz quam in Sect. 1 et 2, ventre semper tumide, 
veniricoso-in flatzx. 


3. Cells semilunar, mostly more curved than in Sect.1 and 2, with the belly always tumid, 
ventricosely inflated. 


Cc. Ehrenbersgii, Mznez. 
C. fusoideo-semilunare, ventre inflato, ceterum ut in C. Lunula. (R.) 


Diam.—Lat. 7135” = .0029". Long. g235” =.0042.” 
Syn.—C. Ehrenbergii, Mzenau. Rasenuorst, Flora Europ. Sect. III. p. 131. 
Hab.—Prope Philadelphia. 


“Frond large, stout, about five or six times as long as broad, lunately curved, extremities taper- 
ing; upper margin very convex, lower concave with a conspicuous central inflation; ends 
broadly rounded; large granules, numerous, scattered ; fillets several; e. f. colorless, without 
strie, central suture not evident. Sporangia orbicular, smooth, placed between the but- 
slightly-connected empty conjugated fronds, the endochrome during the process of conjuga- 
tion emerging from the opened apex of a short conical extension from each under side of each 
younger segment (or shorter cone) of each pair of recently divided fronds, the conjugating 
fronds being produced immediately previously by the self-division of a pair of old fronds—two 
sporangia being thus the ultimate produce of the two original fronds. L. J"; B. zip”. 
Archer.” Pritchard’s Infusoria, p. 748. 


Remark.—Fig. 2, pl. 12, represents a plant of this species magnified 160 dia- 
meters. 


C. moniliferum, (Bory) Ears. 

C. semilunare, plus minus curvatum, diametro maximo 6-9 plo longius, ventre inflato, utroque 
polo sensim attenuatum, apicibus achrois obtusis, vesiculis chlorophyllaceis in serie unica 
longitudinali axili dispositis, in quoque crure 7-10; locello apicali submagno, corpuscula 
numerosa includente (corpusculum in quoque locello unicum mobile ellipsoideum, magnitudine 
linee partem millesimam equans, cetera mobilia per totum corporis distributa observavit cl. 
Perty.) (R.) Species mihi ignota. 

Diam.—0.0019"—0.0022”. (R.) 

Syn.—C. moniliferum, RaBenuorst, Flora Europ. Algarum, Sect. ITI. p. 131. 


Hab.—Georgia; Rhode Island; Bailey. 
15 June, 1872. 


114 FRESH-WATER ALG# OF THE UNITED STATES. 


“ Frond smaller than C. Ehrenbergii, stout, five or six times as long as broad, lunately curved, 
extremities tapering, upper margin convex, lower concave, with a central inflation, ends 
rounded; large granules, conspicuous, in a single longitudinal series; e. f. colorless, without 
strie, suture not evident. L. 7’—gy’. B. sty’—ady". Archer.” Pritchard’s Infusoria, 


p. 748. 


C. Leibleinii, K1z. 
C. priore minus, semilunare, magis incurvum, ventre inflato, ad utrumque polum largius attenu- 


atum, apicibus achrois acutis; vesiculis chlorophyll. in quoque crure 5-6, in serie simplici 
axillari dispositis; locello magno, apices versus sito, corpuscula numerosa includente. (R.) 


Diam.—7}35". 
Syn.—C. Leibleinit, Ktrzine. Rasenuorst, Flora Europ. Algarum, Sect. III. p. 132. 
Hab.—Georgia; Rhode Island; Bailey. Pennsylvania; Wood. 


“Frond somewhat stout, distance between the extremities six or eight times the breadth, 
crescent-shaped, much curved, rapidly attenuated, upper margin very convex, lower very con- 
cave, often with a slight central inflation; ends subacute; large granules, in a single series; 
fillets few or indistinct; e. f. somewhat straw-colored, without strie; suture evident. Spo- 


rangium orbicular.” Archer. 


Remark.—Fig. 6, pl. 12, represents this plant, magnified 260 diameters. 


4. Cellule maxime curvate, ventre non tumide. 


4. Cells most curved, the belly not tumid. 


C. Diane, Eure. 

C. anguste fusiforme, semilunare, utroque polo valde attenuatum, apicibus subacutis; cytioder. 
mate achroo (vel dilutissime umbrino), striis subtilissimis medio interruptis predito, in media 
parte striis transversalibus 3-5; vesiculis in quoque crure 6-7, in serie unica axili dispositis ; 
laminis chlorophyllaceis pluribus, spe flexuosis; locello indistincto, corpusculis pluribus 


vivide mobilibus. (R.) 
Diam.—Lat. 755" =.00053”. Long. 7834” = .00082". 
Syn.—C. Diane, EHRENBERG. RABENHORST, Flora Europ. Algarum, Sect. IIE. p. 183. 
Hab.—Georgia; Florida ; Rhode Island; Bailey. Pennsylvania; Wood. 


Frond crescent-shaped, six or eight times as long as broad, much curved, rapidly attenuated ; 
upper margin very convex, lower very concave without a central inflation; ends sobacuite 
with a very slight emargination at the upper outer extremity; large granules in a single 
series; empty frond, somewhat straw-colored, or faintly reddish, without striz, suture evident. 


(A.) 


Remarks.—My. Archer marks C. Venus, K1z., as a doubtful synonym of this 
species; not having Prof. Kiitzing’s work at hand, I do not know whether (0. 
Venus, Kz. is really the following species or not. The two forms here known as C. 
Diane, urs. and C. Venus, Krz. are, however, I think sufficiently distinguished. 

Fig. 4, pl. 12, represents this species of desmid., 


Cc. Venus, Krz. 
C. parvum, plus minus gracile, semicirculare, octies-duodecies longius quam latum, in apices 
subacutos sequaliter sensimque attenuatum ; cytiodermate tenui, leve; laminis neat 
ceis obliteratis ; vesiculis in quoque crure 3-4; locello distincto corpusculis 4-6 repleto. (R.) 


Diam.—.0004”. 


FRESH-WATER ALG# OF THE UNITED STATES, 115 


Syn.—C. Venus, Kivzinc. Rasenuorst, Flora Europ. Algarum, Sect. III. p. 184. 
Hab.—South Carolina. (Ravenel. ) 


Small, more or less slender, semicircular, eight to twelve times longer than broad, equally and 
very perceptibly attenuate at both apices; cytioderm thin, smooth; chlorophyllous lamina 
obliterated ; vesicles in each crus 3-4; vacuole distinct, containing 4-6 corpuscles. 


Remark,—Fig. ‘1, pl. 11, represents in outline a frond magnified 450 diameters. 


Cc. parvulum, Nc. 


C. parvum, semicirculare, medio non tumidum, gracile, anguste lanceolatum, sexies-octies lon- 
gius quam latum, apicibus acutis; cytiodermate tenui, levissimo, vacuato nonnunquam luteolo- 
fuscescente et subtiliter striato; vesiculis uniseriatis, in quoque crure 2-4, varius 1-7; laminis 
chlorophyllaceis 4-5. (R.) 


Diam.—Max. 0.00026”—.00062” (R.) (.0008” W.) 
Syn.—C. parvulum, Nzeet. Rapenuorst, Flora Europ. Algarum, Sect. III. p. 184. 
Hab.—Prope Philadelphia, Wood. 


Small, semicircular, not swollen in the middle, slender, narrowly lanceolate, six to eight times 
longer than broad, with the apices acute; cytioderm thin, very smooth, when empty some- 
what yellowish-fuscous and finely striate; vesicles uniseriate, in each crus 2-4, rarely 1-7; 
chlorophyllous lamina 4-5. 


Remarks.—I have referred to this species a desmid which I have found about 
Philadelphia, and which agrees in all respects with the description of Prof. Raben- 
horst except in attaining a larger size. 

Fig. 5, pl. 12, represents this plant magnified 450 diameters. 


Cc. Jennerii, Rarrs. s 
C. cylindraceo-fusiforme, semilunare, leve, utrinque modice attenuatum, sexies-octies longius 
quam latum, apicibus obtuse rotundatis; vesiculis in quoque crure 5—7, in serie unica axili 
dispositis; laminis chlorophyllaceis 2-3; locello subaquali magno, corpusculis numerosis 
impleto. (R.) 
Diam.—0.00057”. (B.) 
Syn.—C. Jennerii, Rats. RaBENHORST, Flora Europ. Algarum, Sect. III. p. 134. 


Hab.—Rhode Island, Bailey. 


Frond small, distance between the extremities six or seven times the breadth, crescent-shaped, 
much curved, gradually tapering (sometimes with an obscure central constriction); upper 
margin very convex, lower very concave without a central inflation ; ends obtuse, rounded ; 
large granules in a single series; e. f. colorless without strie. L. sty’. B. q7gq”. Archer. 
Pritchard’s Infusoria. 


b. Zygosporx plerumque quadrangulares, cellularum crura longe vel longissime producta, 
sexpe setiformia. 
b. Zygospores mostly quadrangular, crura of the cells greatly produced, often setiform. ~ 


C. rostratam. Ere. ; 
C. corpore lanceolato-fusiformi, utrinque valde et longe attenuato, leviter eurvato, striato ; Cor 
nibus setaceis singulis corpus vix equantibus, sepius longe brevioribus ; cytiodermate dilute 
umbrino vel luteolo, dense striato ; vesiculis uniseriatis, in quoque crure 5-6 ; locello oblongo, 
sepius indistincto, corpusculis 12-15 vivide se moventibus. (R.) 


116 FRESH-WATER ALG OF THE UNITED STATES. 


Diam.—0.0008". (0.0009/’-0.0016.’” R.) 
Syn.—C. rostratum, EHRENBERG. RaBENHoRST, Flora Europ. Algarum, Sect. III. p. 135. 
Hab.—In fossis, prope Philadelphia; Wood. 


Body lanceolate-fusiform, at each end greatly and for a long distance attenuated, slightly curved, 
striate ; crura setaceous and scarcely as long as the body and sometimes much shorter; cytio- 
derm light or luteolous, densely striate, vesicles uniseriate, 5-6 in each crus; vacuoles oblong, 
often indistinct, containing from 12-15 actively moving granules. 


Remark.—Fig. 3, pl. 12, is a drawing of this species, magnified 260 diameters. 


C. setaceum, Exzs. 

.C. corpore anguste lanceolato, recto vel subrecto, distincte striato, utrinque in rostrum setaceum, 
levissime incurvum, obtusum, longissime porrecto; singulo rostro corpore 3-4 plo longiore; 
et vesiculis et locello indistinctis. (R.) ‘ 

Diam.—Max. (plerumque) 0.0004”—0.00044.” (R.) 

Syn.—C. setaceum, EHRENBERG, Flora Europ. Algarum, Sect. III. p. 136. 

Hab.—Stonington. (Lewis) Pennsylvania; Wood. Georgia; Florida; Providence, Rhode 

Island; Bailey. 


Frond very slender, from twenty to twenty-five times as long as broad, narrow-lanceolate ; 
upper and lower margins nearly equally and but slightly convex; each extremity tapering 
into a very long and slender setaceous colorless beak, longer than the body, ultimately curved 
downwards, ends obtuse; e. f. colorless, strix close, faint, central suture solitary. Sporangium 
cruciform. L. pte”. B. ggg”. Archer. Pritchard’s Infusoria. 


C.Amblyonema, Exzs. 
C. filiforme, cylindricum, lve, utroque fine parum attenuatum, apice rotundum. (R.) 


Syn.—C. lineatum, Burs. Battey, American Journal of Science and Arts, 1841, p. 3038. 


C. Amblyonema, Eure. Verbreit. p, 123. Rasennorst, Flora Europ. Algarum, Sect. 
IIT. p. 138. 


Hab.—West Point, New York; Providence, Rhode Island, Bailey. 


Filiform, cylindrical, smooth, gradually attenuated at each end; the apex rounded. 


Remarks.—I have never recognized a specimen of this species, nor have I had 
access to the original description of Ehrenberg. 


Genus TETMEMORUS. 


Cellule cylindrice vel fusiformes, rectse, medio distincte constrict, utroque polo anguste incise 
cytioderma sat firmum, plerumque granulatum vel punctatum. 


Cells cylindrical or fusiform, straight, distinctly constricted in the middle, narrowly incised at 
each end. Cytioderm firm, mostly punctate or granulate. 


T. Brebissonii, (Mznan.) Razrs. 


T. diametro 4-6 plo*longior; a fronte cylindricus, utroque polo non attenuatus sed rotundato- 


truncatus ; a latere fusiformis et a medio in apices rotundatos sensim attenuatus; cytiodermate 
striato-punctato. 


Diam.—7}2," = -001 6", 


Syn.—T. Brébissonii, MENGHEINI, RABENHoRsT, Flora Europ, Algarum, Sect. III. p. 189 


FRESH-WATER ALG OF THE UNITED STATES. 117 
Hab.—In fossis, Atlantic States. 


Four to six times longer than broad; from the front cylindrical, not attenuate at the truncately 
rounded ends; viewed laterally fusiform, attenuated from the middle to the rounded ends; 
cytioderm striately punctate. 


Remarks.—The central constriction is more apparent in the lateral than front 
view. When the frond is full of endochrome the puncte on the outer wall are 
not apparent, but when it is empty they are seen to be small, and closely arranged 
in stria-like rows. This species extends through all the Atlantic sea-board States. 
Prof. Bailey has found it in South Carolina and Florida, as well as in Rhode Island. 
T have collected it in Centre County, of this State. 

Fig. 3, pl. 21, represents an empty half frond of this species; 3 a the outline of 
the frond. 


T. granulatus, (Brés.) Ratrs. 

T. habitu Tetm. Brébissonii, sed major et cytiodermate irregulariter granulato-punctato. (R.) 

Diam.—7z}hy” = .0013”. 00155”. RB.) 

Syn.—T. granulatus, (Bripisson.) Ratrs. RaBenyorst, Flora Europ. Algarum, Sect. III. 

p. 140. 

Hab.—Prope Philadelphia ; Wood. Rhode Island; (S. T. Olney.) Thwaites. South Caro- 

lina ; Bailey. 

Frond somewhat longer than T. Brebissonii, about five or six times longer than broad; in both 
f. v. and s. v. fusiform, the constriction a very shallow groove, ends with a hyaline lip-like 
projection extending beyond the notch; endochrome with a longitudinal series of large 
granules; e. f. punctate, the puncta scattered, except near the constriction; where they are 


disposed in two transverse rows. Sporangium orbicular, smooth, margin finely striated, placed 
between the deciduous empty fronds. L. y}y”. B. hy”. Archer. Pritchard’s Infusoria. 


Remark.—Fig. 8, pl. 12, represents this species magnified 450 diameters. 


T. giganteus, Woop. 
T. maximus, oblongus, diametro 3 plo longior; apicibus haud attenuatis, late rotundatis; suturis 
profundis, linearibus; cytiodermate irregulariter granulato-punctato. 
Diam.—724,y" = .0031”. 
Syn.—T. giganteus, Woop. Proc. Acad. Nat. Sci., 1869. 
Hab.—In stagnis, Centre County, Pennsylvania. 


Very large, oblong, 3 times longer than broad ; with the ends not attenuate but broadly rounded ; 
suture profound, linear; cytioderm irregularly granulately punctate. 


Remarks.—I found this beautiful desmid in a stagnant pool in Bear Meadows, 
Centre County, in the month of August. It is very different in its outline from 
its nearest ally, 7. granulatus. The diameter is preserved uniform until near the 
end, where there is an alteration in the line of the margin, so as to cause 
some contraction, which is, however, wanting in some specimens. The ends are 
therefore broad and obtuse. The size is also double that of 7. granulatus. 

Fig. 7, pl. 12, represents a frond of this species magnified 260 diameters. 


118 FRESH-WATER ALG& OF THE UNITED STATES. 


TT. levis, (Kurz.) Ratrs. 
T. Brébissonii formis similis sed parvior, 3-4 plo longior quam latus; cytiodermate plerumque 


levissimo, interdum indistinctissime punctato. 
Diam.—yZoy" = 00066". 
Syn.—T. levis, Kirzinae. Ratrs. RaBennHorst, Flora Europ. Algarum, Sect. III. p. 140. 


Hab.—In aquis quietis, prope Philadelphia. 
Similar in form to T. Brébissonii, but smaller, 8-4 times longer than broad; cytioderm mostly 
very smooth, sometimes indistinctly punctate. 


Remarks.—Prof. Rabenhorst states that the cytioderm of this species is very 
smooth, and Mr. Ralfs says that he has failed to detect any punctations, but also 
states that “ Mr. Jenner and Mr. Ross assure me that they (puncte) are scattered 
as in T. granulatus.” Ihave no doubt of their existence in certain individuals, 


whilst in other cases they appear to be absent. 


Genus PLEUROTAINIUM, Naat (1849). 


Cellule singule in aqua natantes, rectz vel subrecte, cylindrice vel fusiformes, valde elongate, 
utroque polo rotundate vel truncatz, medio leviter constricte, ex transverso circulares. Cytio- 
plasma chlorophyllaceum in laminis longitudinalibus pluribus dispositum, et sub utroque polo locello 
rotundato corpusculis se vivide moventibus impleto instructum. 


Cells single, swimming in water, straight or nearly so, cylindrical or fusiform, very much elongate, 
rounded or truncate at each end, in the end view with a circular outline. Chlorophyllous protoplasm 
arranged in longitudinal laming and furnished at each end with a round vacuole containing actively 


moving corpuscles. 


Remarks.—This genus appears to include the main portion of the species, which 
have been described under the name of Docidium; the remainder being represen- 
tatives of a number of genera. I have not had access to the original description 
of Docidium, and do not know in what year it was published; but, according to 
De Bary, Docidiwm is much the older name (“Ueber de Conjugat.,” p. 75). M. 
De Bary states, however, that he prefers the name of Negeli, because that autho- 
rity first defined the genus and his name expresses very clearly the character 
of it, as well as from the circumstance that the name Docidium having been 
made to cover a heterogeneous mass of species, its retention might cause confu- 
sion. I confess to thinking that this action of De Bary is not in accordance with 
the recognized laws of priority, but, in the absence of the original description, 
have thought best to follow it. 


P. trabecula, (Esrs.) Naceti. 
P. spe valde elongatum, octies vicies-longius quam latum, cylindraceum, utroque fine levissime 
attenuatum aut incrassatum, juxta medium constrictum sepius bigibbum (quasi biundatum), 
apicibus late truncatum ; cytiodermate tenui levi, achroo. (R.) 


Diam.—7z}y" = .0013". 


Syn.— Docidium Ehrenbergit. Rats.” BAr.ey, Microscopical Observations. Smithsonian 
Contributions. 


ca 


Pleurotenium trabecula, (Eur.) Nacernt. Rasengorst, Flora Europ. Algarum, Sect. 
III. p. 141. , 


Hab.—South Carolina, Georgia, Florida ; Bailey. Pennsylvania ; Wood, 


FRESH-WATER ALGA OF THE UNITED STATES. 119 


(Docidium Ehrenbergii. Raurs.) Frond slender, linear; suture forming a very sharply 
defined rim; segments 8-12 times longer than broad, basal inflation having another smaller 
one above it, sides otherwise straight, parallel; ends crenate, owing to a number of emargina- 
tions on the edge of the truncate extremities, from three to five of the crenations being 
usually visible; e. f. punctate or rough with minute granules. Sporangium suborbicular or 
elliptic, or slightly angular, smooth, placed between the deciduous empty fronds. Ciliated 
zoospores formed by segmentation of the cell contents, and their emission effected through 
the opened apex of each one, two or three, especially, formed lateral tubes arising from be- 

. neath the base of one of the segments. Archer. 

Remarks.—This species is quite common around Philadelphia; but I do not 
remember ever to have seen one with the cell-wall granulate. The smaller of the 
two umbonations near the centre is often wanting or exceedingly small, and the 
erenulations in the ends are very often obsolete. 

Fig. 9, pl. 12, represents a cell of this species magnified 160 diameters. 


P.Baculum, (Brés.) Dz Bary. 
P. priori simile, sed gracilius, angustius et plerumque longius, medio tantum semel constrictum ; 
cytiodermate levi. (R.) Species mihi zgnota. 
Diam.—0.00054”—0.0009”. (R.) 


Syn.—P.Baculum, (Brés.) DeBary. RaBenuHorst, Flora Europ, Algarum, Sect. ITI. p. 141. 
Hab.—Georgia ; Bailey. 


Frond slender, suture not prominent; segments very many times longer than broad, basal in-. 
flation very conspicuous, solitary, sides otherwise straight, very nearly parallel, large gran- 
ules of the endochrome in a single series; ends entire; e. f. without puncta. L. y+,” B. 


1937 
P. breve, Woop. 

P. robustum, diametro 4-8 plo longius, in medio distincte constrictum sed haud undulatum, 
utroque polo nonnihil attenuatum; apicibus truncatis et nonnihil rotundatis; cytiodermate 
crassissimo, dense granulato-punctato; marginibus vel rectis, vel breve undulatis. 

Diam.—.0038”—.00095”. 

Syn.—P. breve, Woop. Proc. Acad. Nat. Sciences, 1869. 

Hab.—District of Columbia. (Billings.) 

Robust, 4~8 times longer than broad, distinctly constricted but not undulated in the middle, 
slightly attenuated towards the ends; apex truncate and somewhat rounded ; cytioderm very 
thick, densely minutely granulate; margins either straight or shortly undulate. 

Remarks.—This species was sent to me by Dr. Billings, who obtained it near 
Washington, D. C. The margins are sometimes straightish, but in other fronds there 
are three or more distinct short undulations, or rounded projections in each half 
margin. ‘The cell-wall is excessively thick, especially at the end—in many cases 
much thicker than the drawing. 

Fig. 2, pl. 21, represents an empty frond of this plant magnified 750 diameters. 


P. crenulatum, (Ears.) RABENHORST. 
P. robustum, cylindraceo-subclavatum, octies-duodecies longius quam Jatum, medio undulato- 
nodulosum, stricture medie margine tumido, apicibus late truncatis, altero seepe crenulato ; 


cytiodermate granulato-punctato. (R.) Species mihi ignota. 
Diam.—0.0023". (R.) 
Syn.—P. crenulatum, (HBRB.) RABENHORST, Flora Europ. Algarum, Sect. IIT. p. 142. 


120 FRESH-WATER ALG OF THE UNITED STATES. 


Docidium nodulosum, Brés. Raurs. British Desmidi, p. 155. 
Closterium trabecula, Bartey. American Journal of Science, 1841. 
Hab.—In aquis quietis, South Carolina; Georgia ; Florida; Rhode Island; Bailey. Pennsyl- 
vania; New Jersey ; Wood 
(Docidium nodulosum.) Frond very stout, the thickened sutures forming a projecting rim; 
segments four to six times as long as broad, scarcely attenuated, regularly inflated at intervals 
so as to form an undulated margin, the basal inflation the most prominent, the others, as they 
approach the ends, less so, where they are indistinct or wanting; ends entire; e. f. coarsely 
punctate. L. gy”. B. gig”. Archer. Pritchard’s Infusoria. 


Remarks.—I have found this species in ‘“ Shepherd’s Mill Pond,” near Greenwich, 
Cumberland County, New Jersey, and also in a Spring in the Philadelphia Park, 
near Columbia bridge. 

Fig. 1, pl. 21, represents the outline of a frond of this species magnified 160 
diameters. 


P. clavatum, (K1z.) Dz Bary. 
P. subcylindraceum, multoties (16-24) longius quam latum, ad utrumque polum sensim incras- 
satum, subclavatum, apicibus late truncatis; cytiodermate firmo achroo, dense et irregulariter 
granulato-punctato. (R.) Species mihi ignota. 


Diam.—Max. 0.00165”—0.00147"; min. = 0.0010”—0.00092". (R.) 


Syn.—P. clavatum, (Ktz.) Dz Bary. RaseEnuorst, Flora Europ. Algarum, Sect. ITI. p. 141. 
Docidium clavatum, Kirzina. Ratrs, British Desmidie. AncuER. Pritchard’s Infusoria. 
Hab.—South Carolina; Georgia; Bailey. 


Frond slender, suture scarcely prominent, segments eight to ten times as long as broad, slightly 
clavate near the ends, and ultimately somewhat attenuated, basal inflation sometimes solitary, 
sometimes having another slight one above it; ends entire; e. f. punctate. L. 3”. B. g}y”. 


ae) 
P. undulatum, (Barzzy.) 
D. leve, gracile cylindricum, undulatum, latitudine 18-20 plo longius, medio modice constrictum ; 
cruribus et basi et apice truncatis et crenatis. (R.) Species mihi ignota. 
Syn.—Docidium undulatum, BattEy. Micros. Observ. p. 36. 
Hab.—Florida, Bailey. 


“Segments eight to ten times longer than broad, constricted six to eight times at regular intervals 
throughout their entire length, with the base and ends crenate, smaller than D. nodulosum, 
Brés., with more frequent and deeper constrictions. The same characters distinguish it from 
D. nodosum and D. constrictum.” 


P. nodosum, (Barzey.) 


D. validissimum, undulatum, spinulis sparsis hirsutum, medio valde constrictum, diametro 8-10 
plo longius; cruribus e basi dilatata leviter attenuatis 4-undatis, apicibus quasi productis, 
latissime truncatis; locello apicali ratione parvo, rotundo, corpusculis paucis (ut videtur) 
repleto. (R.) (Species mihi ignota.) 


Syn.—Docidium nodosum, Battery. Micr. Observ., pl. 1, fig. 4. Ras, British Desmids 
p. 218. 


Hab.—United States; Bailey. 


“Frond stout; segments with four prominent nodes separated by constrictions; end view 
crenate. An end view shows that each node is not a simple swelling, but reully formed by 
whorls of tubercles. ‘This species is easily recognized by the deep indentations in its out- 
line, corresponding to the constrictions which separate the transverse rows of knob-like pro- 
jections. It is one of the largest species in the genus,’ Bailey.” Ralfs. 


1 


FRESH-WATER ALGH OF THE UNITED STATES. 121 


P. constrictum, (Barer) 

D. subvalidum, leve, latitudine 10-12 plo longius, medio valde constrictum, stricture margine 
non prominente; cruribus a basi tumida in apicem late truncatum non attenuatis, 4 undu- 
latis. (R.) (Species mihi ignota.) 

Syn.—Docidium constrictum, BAILEY. Ratrs, British Desmids, p. 218. 

Hab.—Rhode Island, Bailey. 


“Frond stout, segments with moderately deep constrictions, which separate four equal, gently 
curving prominences; end view entire. ‘This species is at once distinguished from D. nodosum 
by the cross section of the nodes being a simple circle instead of an indented one,’ Bailey.” 
Ralfs. 


P. verrucosum, (BAILEY) 


D. validum, granuloso-verrucosum, latitudine 10-12 plo longius, undulatum, apicibus integris 
truncatis. (R.) (Species miht ignota.) 


& 


Syn.—Cosmarium verrucosum, BaitEy, Amer. Journ. Sci. and Arts, 1846. 
Docidium verrucosum, Raxrs, Brit. Desm. p. 218. Batey, Micr. Observ. p. 28. 


Hab.—Rhode Island; Bailey. 


“Segments, with numerous whorls of small prominences, which give the margins an undulated 
appearance, all the undulations are equal. ‘ This is a very pretty species with a waved out- 
line, caused by the slight projections, which are arranged in numerous transverse rings,’ 
Bailey.” Ralfs. 


P. hirsutum, (BAILEY) 
D. spinuloso-hirsutum, medio valde constrictum, diametro 10-12 plo longius; cruribus et basi 
et apice subdilatatis, truncatis. (R.) (Species mihi ignota.) 


Syn.—Docidium hirsutum, Bamy, Micr. Observ. p. 36. 
Hab.—Florida; Bailey. 


“Segments many times longer than broad, slightly inflated at the base, surface hirsute. A 
small species resembling D. Ehrenbergii in its form, but strongly hirsute on its outer sur- 
face.” Bailey. 


Genus TRIPLOCERAS, Battey. 


Cellule singule, rect, valde elongate, processus magnorum seriebus transversis armate, utroque 
polo trilobatz, lobis acute bidentatis. 


Syn.— Triploceras, BatLEY, Microscopical Observations, p. 37, Smithsonian Contributions, 1850. 


Célls single, straight, very much elongate, armed with transverse series of large processes, trilo- 
bate at each end, lobes acutely bidentate. 


T. verticillatum, Batey. 

T. cellulis subcylindricis, sed utroque fine leviter angustatis et nonnihil fusiformibus, modice 
robustis, diametro 12-20 plo longioribus; processibus lateralibus robustis, magnis, apice 
emarginatis. 

Diam.—Cum process. 7345” = .00146” ; sine process. reys0” = -00113". 

Syn.—T. verticillatum, BAILEY. Microscopic Observations. Smithsonian Contributions, 1850. 

Docidium verticillatum, Raxrs, British Desmids, p. 218. 

Pleurotenium verticillatum, RaBenHorst, Flora Europ. Algar., Sect. ITI. p. 148. 
Hab.—Rhode Island, New Jersey, Georgia, Florida ; Bailey. Saco Lake, (Dr. Lewis) Wood. 
Subcylindrical, but slightly narrowed at each end, and therefore somewhat fusiform, moderately 

robust, 12-20 times longer than broad; lateral processes large, robust, with their apices 


emarginate. 
16 June, 1872. 


122 FRESH-WATER ALGA& OF THE UNITED STATES. 


T. gracille, Batezy. 
T. cellulis subcylindricis, utroque fine vix angustatis, gracillimis, diametro 25-30 plo longi- 
oribus; processibus lateralibus brevibus, conicis. 
Diam.—Cum process. 755" = .008”; sine proc. yg85q” = -0006”. 


. Syn —T. gracille, BarLuy, Smithsonian Contributions. 
Docidium pristide, Hopson, Magazine Natural History, v. p. 168. 
Pleurotenium gracile, RABENHORST, Flora Europ. Algar., Sect. III. p. 144. 
Hab.—In iisdem cum antecedente locis. 


Subcylindrical, scarcely narrowed at the ends, 25-30 times longer than broad ; lateral processes, 
short, conical. 


Genus SPIROTAENIA, Brés. 


Cellule recte, cylindrice vel subfusiformes, seepe in muco gelatinoso aggregate, medio haud con- 
strictz, utroque polo rotundate vel acuminate. Cytioplasma chlorophyllaceum in laminis spiralibus 


dispositum. 

Cells straight, cylindrical or subfusiform, often aggregated in a gelatinous mucus, not constricted 
in the middle, rounded or acuminate at each end. Chlorophyllous cytioplasm arranged in spiral 
lamina. 


Sp. bryophila, (Bzés.) Rasennorst. 
Sp. mimina, bryophila; cellulis in gelatina matricali consociatis, oblongo-cylindricis, rectis vel 
subcurvatis, bis vel ter longioribus quam latis, utroque polo rotundatis; lamina chlorophyl- 
lacea singula anfractu 1-24. 
Diam.—gggq" = .00033" (0.00024”—.00029". R.) 
Syn.—Spirotenia bryophila, (BREB.) RaBEnHorst, Flora Europ. Algarum, Sect. III. p. 146. 
Hab.—Prope Philadelphia ; Wood. 


“(8. muscicola (De Bary)) Frond cylindrical two to four times as long as broad, ends rounded; 
endochrome a single, broad, smoothly defined, widely wound spiral band, its revolutions very 
few (one or two).” (A.) 


Remarks.—I found this beautiful little desmid on the North Pennsylvania Rail- 
road, near Chelten Hills, growing amongst some mosses which were kept con- 
stantly wet by overhanging dripping rocks. It formed little transparent masses of 
almost colorless jelly looking much like drops of dew. It agrees well with the 
descriptions of the European form, except that there were generally from 2-24 
turns of the spiral, and the cells exceed somewhat the measurements of Prof. 
Rabenhorst. The cells are closely placed in the jelly. 

Fig. 10, pl. 12, represents some plants of this species, 


Sp. condensata, (Brés.) Rasennorst. 
Sp. cellulis cylindraceis, rectis (vel leviter curvatis) octies vel decies longioribus quam latis, 
utroque polo rotundatis; laminis chlorophyll. singulis, anfractibus subarctis (plerumque 8-12). 


Diam.—0.00075". 
Syn.—Sp. condensata, (Brés.) Rasennorst, Flora Europ. Algarum, Sect. III. p. 146. 
Hab.—Florida; Rhode Island; Bailey. Pennsylvania; Wood. 


Frond cylindrical, two to four times as long as broad, ends rounded; endochrome a single, 
broad, closely wound spiral band, its revolutions numerous. L. 535”. Br. yggg”. Archer. 
Pritchard’s Infusoria. 


FRESH-WATER ALGE&E OF THE UNITED STATES. 1238 


Remarks.—The only specimens that I have seen of this species were found in a 
spring in the Philadelphia City Park, near Columbia bridge. 
Fig. 11, pl. 12, was drawn from one of these specimens. 


Genus SPHEROZOSMA, Corpa. 


Cellule compress, medio transversim profunde inciss, itaque bilobate, in quoque lobo massa 
chlorophyllosa quadriradiata nucleum amylaceum involvente preedite, in filum planum teniiformem 
literaliter isthmis conjuncte. Zygospore globose vel ovales, glabra. (R.) 


Syn.—Isthmosira, Kz. 
Odontellx, spec., EuRB. 
Isthmiz, spec., MENEG. 
Spondylosium, Bris. 
Cells compressed, transversely very deeply incised in the centre and therefore bilobate, furnished 


in each lobe with a quadriradiate mass of chlorophy] surrounding a starch grain, conjoined laterally 
by isthmuses in a teniform fascia. 


femarks.—I have never found any species of this genus in America. Professor 
Bailey has, however, detected the following:— 


Sph. excavatum, Ratrs. 

Sph. plerumque nudum (sine tubo mucoso) sph. vertebratum multo minus; cellulis diametro 
duplo-longioribus, medio excavato-constrictis, a latere ellipticis utroque polo rotundatis; lobis 
brevibus truncato-rotundatis, levibus vel granulato-denticulatis ; isthmis binis parvis verru- 
ciformibus; zygosporis plerumque ovatis. (R ) 


Latit. filor. 0.00047”—0 00032”. (R.) 
Syn.—Sph. excavatum, Raurs, British Desmids, p. 67. 
Hab.—Florida; Georgia; South Carolina; Rhode Island; Bailey. 


“Joints longer than broad, having a deep sinus on both sides and two sessile glands at each 
margin at their junction, very minute, seldom more than twenty-five joints in the filament, 
which is fragile, and finally separates into single joints; at their junction, in the front view 
are two minute glands or processes, situated one near each angle, and nearly invisible before 
the escape of the endochrome. ‘The joints are nearly twice as long as broad and much con- 
stricted in the middle; the constriction is like an excavation or broad sinus on each side, so 
that the margins of the filaments appear sinuated. The endochrome is pale blaish-green 
with minute scattered granules. The transverse view is oblong with four sessile glands, two 
on each side and situated near the ends.”—Ralfs’ Brit. Desm., p 61. 


Sph. pulchrum, Batey. 
Sph. cellulis oblongo-quadrangularibus, diametro duplo-brevioribus, acute incisis, arcte con- 
nexis; lobis oblongis rectis, apice rotundatis; isthmis nullis, vagina mucosa ampla dis- 


neta. (R.) ~ 

Syn.—S. pulchrum, Baty. Ratrs, British Desmid., p. 209 (Cum icone). 

Hab.—West Point, New York; Princeton, New Jersey; Bat.ey. 

“ Joints twice as broad as long, deeply incised on each side; junction margins straight, con- 
nected by short bands.” 


Remark.—* Prof. Bailey informs me that this species is twice as large as Sph. 
vertebratum,” RALFS. 


124 FRESH-WATER ALG& OF THE UNITED STATES. 


Sph. serratum, Baley. 

Sph. cellulis diametro duplo brevioribus, profunde et acute excisis, arcte conjunctis; lobis 
utrinque cuspidatis, paulum conniventibus; isthmis nullis; vagina crassa. (R.) 

Syn.—Sph. serratum, BAILEY, Micros. Observation. Smithsonian Contributions, 1850. Cum 

icone. 

Hab.—South Carolina; Georgia; Florida; Bailey. 

“ Joints broader than long, deeply notched or divided into two transverse portions with acute 
projecting ends, which give a serrated outline to the chain.” Bailey. 


Genus HY ALOTHECA. 


Cellule breve, cylindric, medio non profunde constrict, a latere disciformes, in fila confervacea 
sine isthmis arcte conjuncte et vagina mucosa ampla achroa incluse. Massa chlorophyllosa in 


quaque semicellula 4-8, 5-10 radiata. 


Cells short, cylindrical, not profoundly constricted in the middle, disciform in the end view, 
closely united without intervening isthmuses into a confervoid filament, which is inclosed in an 
ample mucous sheath. Chlorophyl masses in each cell 4-8, 5-10 radiates. 


H. disilliens, (Smirx) Brés. 

H. fasciis prelongis; cellulis oblongo-quadrangularibus, diametro sub-duplo brevioribus, inter- 
dum ante divisionem subequalibus, angulis nounihil rotundatis, pleruamque medio obsolete 
constrictis, sepe haud constrictis. 

Diam —0.00089’’—0.00098’". (R.) 

Syn.—H. disilliens, (Smita) Brés. RaBennorst, Flora Europ. Algarum, Sect. ITI. p. 152. 

Hab.—South Carolina; Florida; Rhode Island; Bartey. Rhode Island (S. T. Olney), 

Thwaites. Pennsylvania; Wood. 


Filament very long, cells oblong, quadrangular, about one-half as long as broad, sometimes before 
division as long as broad, angles somewhat rounded, mostly obsoletely constricted in the 
middle, often not constricted. 


Remarks.—The specimens which I have identified as H. disilliens, agree with 
the various figures and descriptions of the European form, in every thing except 
that in many cases there is no constriction whatever in the centre of the cell, and 
when the constriction does exist, it is never so pronounced, as some of the descrip- 
tions indicated. The plant is very common about Philadelphia, growing in springs 


and ditches. 
Fig. 12, pl. 12, represents this part of a filament of this species, 


Hi. mucosa, (Mzrv.) Exrs. 
H. fasciis confervaceis, minus fragilibus; cellulis quadrangularibus, diametro eequalibus vel 
subequalibus, medio non constrictis, ad utrumque finem (annuliformi-bicarinatis) bidentatis. 
(B.) Species mihi ignota. 
Diam.—0.00073”—0.0008”. (R.) 


Syn.—Gloeoprium mucosum, Hassat, Fresh Water Algae, p. 346. 
H. mucosa, (Merv.) Eurg. Rasennorst, Flora Europ. Algarum, Sect. IIT. p. 132. 


Hab.—Rhode Island; (S. T. Olney) Thwaites. 


Filament scarcely fragile, mucous sheath very broad; joints about as broad as long, not con- 
stricted, but having at one of the ends a minute bidentate projection on each margin, the 


FRESH-WATER ALGA OF THE UNITED STATES. 125 


adjoining ends of the next joint being similar, these projections being produced by an annular 
grooved rim. L. ys'gy’—600".  B. apq”—ayy7". (Archer) 


Genus BAMBUSINA. 


Cellule oblongo-orculiformes, in filamenta articulata nodosa dense conjuncte, medio vitta trans- 
versa carinis duabus annuliformibus limitata instruct, itaque superne et inferne bidentate, fronte 
circulares, supra et infra dente unico prominente. (R.) 


Cells oblong-orculiform, densely united into an articulate nodose filament, surrounded by two 
median bands. 


B. Brébissonii, K1z. 
B. filamentis nodoso-articulatis ; cellulis diametro duplo longioribus. (R.) 


Diam.—0.00077"”—0.00092”. (R.) 
Syn.—B. Brébissonii, Kirzina. Raspennorst, Flora Europ., Algarum, Sect. III. p. 152. 


Hab.—South Carolina. (Ravenel) Wood. South Carolina; Georgia; Florida; Rhode Island. 
Bailey. 


(Didymoprium Borreri, (Ralfs)) Joints inflated, barrel-shaped, longer than broad, without a 
thickened border at their junction; angles bicrenate, crenatures rounded; transverse view 
circular; sporangium elliptic, formed within the (for some time) persistent extensions from 
the conjugating joints, which do not previously break up into single joints, but couple, still 
united in the filament, in a confused or zigzag manner, some of the joints remaining unchanged. 


L. ats’: B. yos0": 
Remarks.—The specimens which I have seen agree well with the descriptions, 


except in regard to size; some of the cells which I measured were more than 
zyoy Of an inch in diameter. 


1200 
Genus DIDYMOPRIUM. 


Cellule oblongo-ellipticee, modice compress, ancipites, angulis porrectis inciso-bidentatis, in fila- 
menta articulata biconvexa et torta sine isthmo arcte conjuncte, et in vagina mucosa incluse. 
Cytioplasma chlorophyllosa cellule a fronte cruciatim disposita, cujus crura e laminis duabus parie- 
talibus divergentibus granum amylaceum unicum involventibus formantur. 


Cells oblong-elliptical, moderately compressed, two-edged, with the produced angles incisely-biden- 
tate, closely united into a biconvex and twisted filament, which is inclosed in a mucoid sheath, cytio- 
plasm so placed as to be cruciate when viewed from the front (end), each crus composed of two 
parietal divergent lamina, each of which contains a single starch granule. 


D. Grevillii, K7z. 
D. cellulis oblongis diametro duplo brevioribus, saturate viridibus. (R.) 
Diam.0.0024/”—0.0031."" (R.) 
Syn.—D. Grevillii, Kivzine. Rapennorst, Flora Europ. Algarum, Sect. IIT. p. 153. 
Hab.—Georgia, South Carolina; Bailey. Pennsylvania; Wood. 


Sheath distinct ; joints broader than long, with a thickened border at their junction; angles 
bidentate; teeth angular; transverse view broadly elliptic. Sporangium orbicular, formed 
within one of the two conjugating joints, the endochrome passing over from one by a narrow 
connecting tube produced between the otherwise, but little altered, broken-up single joints. (A.) 


Remark.—Fig. 18, pl. 12, represents the end view of a broken filament of this 
species, 


126 FRESH-WATER ALG#Z OF THE UNITED STATES. 


Genus DESMIDIUM. 


Cellule oblongo-tabulares, medio inciso-bilobe, lobis integris vel irregulariter dentatis, a fronte 
tri- vel quadrangulares, angulis obtuse rotundatis, in fila angulosa, prelonga, torta, fragiles arcte 
connexz, Massa chlorophyllosa (a cellule fronte visa) 3-4 radiata; quisque radius e laminis 
duabus lateralibus divergentibus compositus. Zygospore globose vel oblonge, glabre. 


Cells oblong-tabular, medianly incisely bilobate, with the lobes entire or irregularly dentate, as 
seen from the front tri- or quadrangular, and having the angles obtusely rounded, closely conjoined 
into an angular, fragile, twisted filament. Chlorophyl (as seen from the front) 3-4 radiate; each 
radius composed of two lateral divergent lamina; zygospores globose or oblong, smooth. 


D. Swartzii, Ac. 
D. cellulis a fronte triangularibus, diametro 2-3 plo brevioribus. (R.) 


Diam.—0.00096"”—0.00189". (B.) 
Syn.—D. Swartzii, AGarpH. Rasenworst, Flora Europ. Algarum, Sect. ITT. p. 154. 


Hab.—In aquis quietis, Atlantic States. Florida; Georgia; South Carolina; Rhode Island; 
Bailey. New York; Edwards. Pennsylvania; Wood. 


Filament triangular, equal, with a single longitudinal waved, dark line, formed by the third 
angle; joints in front view somewhat. quadrangular, broader than long, with two slightly 
angular crenatures on each lateral margin, united at the whole of their end margins by a 
thickened border, end view triangular; endochrome three-rayed. Archer. Pritchard’s Infu- 
soria. 

D. quadrangulatum, Kz. 

D. quadrangulare, cellulis oblongo-quadrangularibus, diametro 2-3 plo brevioribus, lobis denti- 
formibus obtusis, a fronte sinuato-quadrangularibus, angulis late rotundatis, lateralibus exca- 
vatis. (R.) Species mtht ignota. 


Diam.—0.0021”—0.0029”. Z 
Syn.—D. quadrangulatum, Korzine. Rasennorst, Flora Europ. Algarum, Sect. III, p. 155. 


Filament quadrangular, varying in breadth from its twisting, having two longitudinal waved 
lines; joints in f. v. broader than long, with two somewhat rounded crenatures on each lateral 
margin, united by the whole of their end margins; e. v. quadrangular; endochrome four 
rayed. L. ysyz". B. g},"—ahy”. (Archer) 

D. aptogonium, Bréz. 

D. fasciis pleramque subbrevibus, nudis, perforatis; cellulis quadrangularibus, inciso-bilobis, 

lateralibus concavis, lobis crenatis, a fronte triangularibus (nonnunquam biangularibus), centro 


concavo, angulis rotundatis protensis isthmum brevissimum triplicem efficientibus. (R.) 
Species mihi ignota. 


Diam.—0.00089"—0.00147”. (R.) 


Syn.—Aptogonium desmidium, Ratrs, British Desmids. 
D. aptogonium, Brépisson. RaBennorst, Flora Europ. Algarum, Sect. ITI. p. 155. 


Hab.—Georgia; South Carolina; Bailey. 


Joints in f. v. quadrangular, broader than long, with two rounded crenatures on each lateral 
margin, united at the outer portion only of each end margin by mutual projections, thus pro- 
ducing intervening central oval foramina. Archer. 


Genus APTOGONIUM, Ratrs. 


Cellule 3-4 angulares vel compress, non constrict; margine laterali plane vel crenate, in 
fascias perforato-articulatas, angulares conjuncte. (R.) 


FRESH-WATER ALG OF THE UNITED STATES. 127 


Cells 3-4 angular or compressed, not constricted, their lateral margins plain or crenate, conjoined 
into angular perforately articulate fascia. 


A. Baileyi, Ratrs. 
“ Filament not crenated ; joints about equal in length and breadth. 


Syn.—Odontella? tridentata, Battey. In lit. cum icone (1846). 
Hab.—W orden’s Pond, Rhode Island; near Princeton, New Jersey, with sporangia,” Bailey. 


“Filament triangular; joints excavated at their junction like those of Aptogonum desmidium- 
The joints are not bicrenate, hence the margins of the filament are entire, a character which 
distinguishes it from that species. The end view is triangular, with rounded angles.” Ratrs, 
British Desmidiex, p. 208. 


Genus COSMARIUM, (Corpa) 


Cellule oblong, oblongo-cylindrice, elliptice, vel orbiculares, medio transverse plus minus con- 
strice, utroque polo obtuse vel rotundate et integra, a vertice elliptice. Zygospore muricate vel 
verrucose. 


Cells oblong cylindrical, elliptical or orbicular, more or less transversely constricted in the middle, 
obtuse or rounded, and entire at each end, viewed from the end elliptical. Zygospore warty or 
muricate. 


1. Cellule sejuncte. 
Cells separate. 
Cellule elliptice, vel subelliptice ; semicellule medio nonventricose. 


. Cells elliptical or subelliptical ; semicells medianly not ventricose. 


* 2 8 


Cytiodermate granuloso vel verruculoso. 


* 


Cytioderm granular or warty. 


Cc. margaritiferum, (Turp.) Menaeu. 

C. paulo longius quam latum, profunde constrictum ; sinu amplo, vel modice angusto, interdum 
intra excavato; semicellulis semiorbicularibus, vel reniformibus vel nonnihil quadrangulis 
dorso plerumque late rotundatis ; cytiodermate verruculoso. 

Diam.—Max. yy" = .0006” (0.00073"—0.0012". R.) 


Syn.—Euastrum margaritiferum, Eurs. Baixey, Silliman’s Journal, 1841. 
Cosmarium margaritiferwm (TURPIN), MENEGHINI. RaBenuHorst, Flora Europ. Algar., 


Sect. III. p. 157. 
Hab.—In aquis quietis, South Carolina; Florida; Mexico; Bailey. Pennsylvania, Wood. 


A little longer than broad, profoundly constricted ; sinus. ample or moderately narrow, some- 
times widened on the inside; semicells semiorbicular, reniform or somewhat quadrangular ; 


dorsum mostly broadly rounded ; cytioderm warty. 


Remarks.—I have found a form of this species growing in the vicinity of this 
city, which I at first was disposed to look upon as distinct, but which, in truth, 
grades into the typical form. In it the cells are almost quadrangular, often with 
their basal angles acute. The margin of the frond in C. margaritiferum, as it 
occurs with us, is sometimes distinctly serrate or, more correctly, crenulate from 
the presence of the granulations. The granules are larger than in C. botrytis, but 
smaller than in C. tetrophthalmum. When viewed laterally the semi-cells are 
roundish, or nearly so (according to Ralfs’ elliptical), and closely connected by 


128 FRESH-WATER ALG& OF THE UNITED STATES. 


a very broad neck. I have never seen the sporangia, but, according to Mr. Ralfs, 
they are orbicular and inclosed in a granulated cell. 

Fig. 8, pl. 21, represents half of an empty frond of this species magnified 750 
diameters; and fig. 21, pl. xii., a frond densely filled with living endochrome . 


C. Botrytis, (Bory) Mrneu. 
C. late ovale, profunde constrictum, diametro plerumque 13—2 plo longius; sinu angusto, 
lineare; semicellulis nonnihil triangularibus, apice interdum truncatis, interdum late rotun- 


datis; cytiodermate minute granulato. 
Diam.—zi," = 0.0019" (0.0014"—0.0023"). (R.) 
Syn.—C. Botrytis, (Bory) MENEGHENI. Raxpenuorst, Flora Europ. Algarum, Sect. IIT. p. 
158. 
Hab.—Pennsylvania, Wood. 


C. broadly oval, profoundly constricted, 14-2 times longer than broad; sinus narrow, linear; 
semicells somewhat triangular, with the apex sometimes truncate, sometimes broadly rounded ; 
cytioderm minutely granulate. 


Remarks.—In this species the semicells, as viewed transversely, are broadly 
elliptic in outline. The end view presents a longer narrower ellipse. ‘Their out- 
line, when seen from the front, varies remarkably from that of a very broad semi- 
oval to distinctly triangular with a truncate apex. The granules are small and 
arranged regularly, sometimes they are very obscure. I have often seen the endo- 
chrome so arranged as to leave a large pyriform central vacuole in each cell, com- 
municating with the narrow margin between it and the cell-wall. This vacuole 
was apparently filled with a transparent fluid, in which were minute granules in 
immense numbers, in constant active motion circling among one another and pass- 
ing out, into and along the marginal connecting space. According to Ralfs, the 
sporangia of this species are large (4,;’’), with branched spines. 

Fig. 5, pl. 21,-represents an empty frond of this species; 5 a, outlines of semi- 
cells to show the variations, and fig. 14, pl. 12, represents a frond crowded with 
endochrome, magnified 460 diameters. 


C. ovale, Ratrs. 

C. magnum, ovale, compressum, profunde constrictum, diametro subduplo longius, ambitu inte- 
gerrimum vel crenatum, a vertice late ellipticum; semicellulis basi paulo latioribus quam 
longis, triangulo-rotundatis, disco punctatis, margine verrucis margaritaceis achrois hyalinis 
in series 4 ordinatis. (R.) 


Diam.—Long. 0.0053”—0.0067”. Lat. plerumque-0.0041”". (R.) 
Syn.—C. ovale, Raurs, British Desmidiex, p. 98. 
Hab.—South Carolina; Rhode Island; Bailey. Cobble Mountain, Pa. (Lewis) Wood. 


Frond very large, elliptic, nearly twice as long as broad, constriction very deep, linear; seg- 
ments somewhat broader than long, somewhat triangular, rounded at ends, rough near the 
margin, with a band of large pearly granules, producing a dentate appearance, the dise punc- 
tate; e. v. elliptic. (A.) 


C. Brébissonii, Menzaz. 


C. paulo longius quam latum ; semicellulis semicircularibus, diametro paulo longioribus, angulis 
inferioribus obtusis approximatis, ventre modice concavis subplanis, dorso latissime rotun- 
datis; cytiodermate muricato, muricibus conicis in ordinibus regularibus collocatis. (B.) 


FRESH-WATER ALGA OF THE UNITED STATES. 129 


Diam.—Semicell, 0.0019”—0.0022”. (R.) 
Syn.—C. Brébissonti, MENEGHENI. RaBENHORST, Flora Europ. Algarum, Sect. III. p. 158. 
Hab.—White Mountains, New Hampshire, (Dr. F. W. Lewis) Wood. 


~ Frond somewhat longer than broad, constriction deep, linear; segments semiorbicular, rough 
all over, with somewhat elongate conical scattered pearly granules; e. v. elliptic. (A.) 


Remark.—Fig. 6, pl. 21, represents an empty frond of this species, magnified 
750 diameters. 


C. suborbiculare, Woop. 


C. parvum, suborbiculare, paulo longius quam Jatum, cum margine enormiter crenato vel 
crenato-undulato; semicellulis a latere orbicularibus, a vertice ellipticis; sinu extrorsum 
angustissimo sed introrsum nonnihil excavato; cytiodermate crasso, sparse verruculoso ; 
granulis in semicellulis singulis subdistantibus et in seriebus elongatis, duabus (interdum 
unica) externis curvatis, et in seriebus duabus internis brevibus et rectis. 


Diam.—Lat. ros. = .0012” ; lat. dso = .0013”. 
Syn.—C. orbiculare, Woon, Proceed. Acad. Nat. Se. 1870. 
Hab.—In lacu “Saco,” New Hampshire, (Lewis.) 


Small, suborbicular, a very little longer than broad, with the margin irregularly crenate, or 
crenate undulate; semicells from the side orbicular, from the vertex elliptical; sinus very 
narrow, but within somewhat excavated; cytioderm thick, sparsely coarsely granulated ; 
granules subdistant, in each cell arranged in one or two curved marginal series and in a cen- 


tral group of two or three short rows. ; 


Remarks.—The arrangement of the granules in this desmid is peculiar, one, or 
sometimes two rows of large obtuse pearly granules are placed at rather wide in- 
tervals along the whole outer margin, and then in the centre of each semicell is a 
group of two or three, or even more short straight rows of three or four similar 
but rather smaller granules. ‘The isthmus is rather broad and short; sometimes it 
has on it one or two granules. 

Fig. 9, pl. 21, represents an empty frond of this species, magnified 750 diame- 
ters; 9a, the outline of the end view of the same. 


C. tetrophthalmum, (K1z.) Brés. 

C. tertiam partem circa longius quam latum, profunde constrictum; sinu angusto, plerumque 

. sublineare ; ambitu obtuse crenato; semicellulis nonnihil semicircularibus, ventre subplanis, 
dorso rotundatis; cytiodermate verruculoso ; verruculis magnis, obtusis, subordinatim dispo- 
sitis. 

Diam.— 3959" ad .0025”. 

Syn.—C. tetrophthalmum, (KotTz1N@), Brépisson. RaBENHORST, Flora Europ. Algarum, Sect. 
IIT. p. 159. 

Hab,—New Jersey ; Wood. 


About one-third longer than broad, deeply constricted ; sinus narrow, mostly sublinear; margin 
obtusely crenated; semicells somewhat semicircular, belly nearly even, dorsum rounded ; 
cytioderm warty ; prominences large, obtuse, arranged somewhat regularly. 


Remarks.—The only specimens I have seen, and I believe the only ones hitherto 
17. «July, 1872. 


130 FRESH-WATER ALG& OF THE UNITED STATES. 


found on the continent, were collected by myself in ‘‘Shepherd’s Mill Pond,” near 
Bridgeton, Cumberland County, New Jersey. 
Fig. 7 a, pl. 21, represents the outline of a frond magnified 460 diameters. 


C. amoenum, Brés. 

C. mediocre, oblongum cylindricum, leviter compressum, diamétro duplo fere triplove longius, 
utroque polo rotundatum, medio profunde constrictum, sinu angusto, lineari, ambitu granulis 
margaritaceis achrois obsessum, a vertice ellipticum ; semicellulis oblongo-rotundatis, dorso 
alte convexis, lateribus vero rectis parallelis, angulis inferioribus rectis et subacutis; cytio- 
dermate granuloso-verrucoso, verrucis hyalinis in series regulares dispositis. (R.) Species 
mihi ignota. 

Long. 0.0017”—0.1016" ; lat. 0.00087”. (R.) 

Syn. —C. amenum, Brésisson. Rasenuorst, Flora Europ. Algar., Sect. III. p. 159. 

Hab.—Florida; Bailey. Rhode Island (S.°T. Olney); Thwaites. 


Frond twice as long as broad, sides parallel, ends rounded, constriction deep, linear; segments 
rough with crowded obtuse papilla-like pearly granules; s. v. much compressed, about thrice 
as long as broad; e. v. elliptic. (A.) 

** Cytiodermate glabro. 


** Cytioderm smooth. 


C. Cucumis, Coxzpa. 
C. ovale ellipticum, utroque polo late rotundatum, tertiam partem vel duplo longius quam latum, 
profunde constrictum; sinu lineari; semicellulis angulis inferioribus rotundatis, cytiodermate 
glabro, haud punctato. : 


Diam.—Max. long. 345” = 0.0026"; lat. 7135” = .0019". 
Syn.—C. Cucumis, Corpa. Rasenuorst, Flora Europ. Algarum, Sect. III. p. 161. 
Hab.—South Carolina; Georgia‘; Florida; Bailey. Pennsylvania; Wood. Saco Lake, (Lewis.) 


Oval or elliptic, at each end broadly rounded, one-third to twice as long as broad, profoundly 
constricted ; sinus linear; semicells with their inferior angles rounded; cytioderm smooth, 
not punctate. 


Remarks.—This species is very abundant around Philadelphia. The semicells 
generally each contain two large globular masses placed near the median line, 
which are sometimes hidden by the crowded endochrome. 

Figs. 15, 15 a, pl. 12, represent this species with their endochrome in different 
conditions ; 15 4, represents a monstrous frond, which had attempted to divide, but 
had not succeeded in so doing. 


Cc. depressum, Batiry. 


“ Elliptical, binate, division in the plane of the longest axis. Segments entire, nearly twice as 
long as broad, rounded above, very much flattened at base. 


Hab.—Lakes in Florida. 


This species resembles C. bioculatum, Brés.; but the segments are much closer together, and 


ate angular, not rounded at the basal extremities.” Barry. Microscopical Observations. 
Smithsonian Contributions. 


C. pyramidatum, Brés. 


C. mediocre, ovale vel subovale, utroque polo truncatum, medio profunde constrictum, duplo 


FRESH-WATER ALG# OF THE UNITED STATES. 131 


fere longius quam latum; semicellulis breviter pyramidatis, angulis inferioribus rotundatis, 
apice (dorso) modo truncatis modo rotundatis, a vertice late ellipticis; cytiodermate punc- 
tato vel subtilissime granulato. (R.) 


Long. 0.0021”—0.0037”. Lat. max. 0.0026”. 


Syn.—C. pyranvidatum, Bréstsson. RaBenuorst, Flora Europ. Algarum, Sect. III. p. 162. 
Hab.—Georgia ; Florida; Bailey. Pennsylvania ; Wood. 


Frond scarcely twice as long as broad, suboval ; constriction deep, linear ; segments pyramidal, 
rounded at basal angles, somewhat truncate at the ends, punctate ; e. v. broadly elliptic. (A.) 


Remark.—Fig, 14, pl. 13, is a drawing of this species. 


€. bioculatum, Brés. 


C. parviter, circiter tam longum quam latum vel paulo longius, profunde constrictum, sinu ex- 
trorsum ampliato; semicellulis diametro duplo latioribus, elliptico-prope hexagonis angulis 
obtuse rotundatis, integerrimis aut levissime crenulatis ; cytiodermate levi vel subtilissime 
punctato. (R.) Species mihi ignota. . 


Long. 0.00069”. Lat. 0.00066”. (R.) 
Syn.—C. bioculatum, Briépisson. Rasenuorst, Flora Europ. Algarum, Sect. ITI. p. 163. 
Hab.—Rhode Island, (S. T. Olney) Thwaites. 


Frond minute, about as long as broad, constriction deep, producing a gaping notch at each 
side; segments about twice as broad as long, elliptic, smooth; s. v. compressed s. v. elliptic. 
Sporangium orbicular with conical spines. L. yyg”; B. yyy”. (A.) 


C. Meneghenii, Bris. 


C. parvum, tam longum quam latum, modo paulo-longius, modo paulo-brevius, profunde con- 
strictum, sinu lineari, extrorsum non ampliato; semicellulis subquadratis, leviter sinuato- 
hexagonis ; angulis rotundatis, cytiodermate levi vel subtillissime punctato. (R.) 


Long. 3y'”--2'" = 0.00103"—0.0013"; lat. y5’”-—y}5'" = 0.00081" —0.00089". (R.) 
Syn.—C. Meneghenti, Brézisson. Rasenuorst, Flora Europ. Algar., Sect. III. p. 163. 
Hab.—Pennsylvania ; Wood. 


Frond very minute, rather longer than broad, constriction linear ; segments subquadrate, bicre- 
nate at the sides and ends, smooth; e. v. elliptic. (A.) 


Remark.—Fig. 18, pl. 12, represents a frond of this species, magnified 750 
diameters, ; ‘ 


C. crenatum, Ratrs. 

C. oblongum, tertiam partem circa longius quam latum, profunde constrictum, sinu lineari an- 
gusto; semicellulis e basi Jata subsemicircularibus, dorso plus minus depressis vel truncatis, 
ambitu crenatis vel regulariter undulato crenatis, crenis 10-14; cytiodermate punctato. (R.) 
Species mihi ignota. 

Long. 0.0021”—0.0023” ; lat. 0.0015”. (R ) 

Syn.—C. crenatum, Ratrs, British Desmidiex, p. 96. 

Hab.—Rhode Island; (S. T. Olney) Thwaites. 


Frond slightly longer than broad, constriction linear; segments semiorbicular, ends and sides 
broadly rounded, crenate or minutely undulate at margin; e. v. elliptic. Sporangium orbi- 
cular, spinous ; spines elongate, slender, swollen at the base and divided at the apex. L. gig”; 


1 
B. B71 . 


132 FRESH-WATER ALG# OF THE UNITED STATES. 


C. undulatum, Corpa. 

C. submediocre, oblongum, diametro subduplo longius, utroque polo late rotundatum, ambitu 
leviter sinuato-undulatum, profunde constrictum, sinu lineari extrorsum paullum ampliato ; 
semicellulis semiorbicularibus, et dorso et lateribus late rotundatis, margine undulato-crenatis, 
crenis 9, sublatis ; cytiodermate levi; zygosporis sphericis spinis elongatis, apice bi-tri-fidis 
obsitis. (R.) Species mihi ignota, 

Long. 0.0024”. Lat. 0.0017”. (R.) 

Syn.—C. undulatum, Conpa. RasenuHorst, Flora Europ. Algarum, Sect. III. p. 165. 

Hab.—South Carolina ; Rhode Island; Bailey. 


Frond rather larger than that of C. crenatum, slightly longer than broad, constrictions linear ; 
segments semiorbicular, ends and sides broadly rounded, crenate or minutely undulate at the 
margin; e. v. elliptic. Sporangium orbicular, spinous; spines elongate, slender, swollen at 
the base and divided at the apex. (A.) 

b. Semicellule medio-ventricoso inflate. 

b. Semicells medianly ventricose. 

* Cytiodermate lzxvit. 

* Cytioderm smooth. 


Cc. sublobatum, (Bréz.) ARcuzr. 

C. parvum, oblongo subquadratum, diametro subduplo longius, sinu angusto lineari; semicel- 
lulis subquadratis, e basi dilatata ad verticem sensim angustatis, angulis et inferioribus et 
superioribus rotundatis, dorso late truncatis lateribusque leviter sinuatis; cytiodermate 
levissimo. (R.) 


Long. 0.00179”—0.00196". Lat. max. 0.0015”—0.00157”. (R.) 


Syn.—C. sublobatum, (Brépisson) Axcuer. Pritchard’s Infusoria, p. 731. 
Hab.—Georgia; Florida; Rhode Island; Bailey. 
Frond scarcely twice as long as broad, oblong; constriction linear, segments subquadrate, 


somewhat wider at the base, lateral and end margins slightly concave, smooth and trans- 
verse vein cruciform. (A.) 


* * Cytiodermate granulato. 
* * Cytioderm granulate. 


Cc. ornatum, Ratrs. 

C. parvum, plerumque tam longum quam latum; semicellulis reniformibus, diametro duplo 
longioribus, angulis inferioribus una cum lateribus rotundatis; dorso sub-producto late trun- 
catis; cytiodermate granulato-verruculoso ; zygosporis longe spinosis, spinis elongatis apice 
furcatis. (R.) Species mihi ignota. 

Long. 0.0016”—0.0015". Lat. 0.0016”. (R.) 

Syn.—C. ornatum, Ratrs, British Desmidiew, p. 104. 

Hab.—Rhode Island; (S. T. Olney) Thwaites. 


Frond in f. v. about as long as broad, constriction deep, linear; segments semiorbicular or 
subreniform, with a central truncate projection at the ends produced by the continuation of a 
central inflation, rough towards the margin and on the inflation with pearly granules; e. v. 
with a rounded lobe on each side. Sporangium orbicular, spinous; spines elongated, dilated 
at the base and slightly divided at the extremity, g1”. (Archer.) 


Cc. commissurale, (Brés.) 


C. minutum, fere dimidio latins quam longum, profundissime constrictum, sinu amplo basi ex- 
cavato; semicellulis anguste reniformibus, diametro paene triplo longioribus, leviter incurvis, 


FRESH-WATER ALG#A OF THE UNITED STATES. 133 


angulis rotundatis, dorso truncato-rotundatis, margine crenulato-dentatis, a dorso oblongis, 
medio ventricosis, utroque polo plus minus tumidis; cytiodermate granulato margaritifero. 


(R.) 
Long. 0.0010”—0.0012.” Lat. 0.0013”—0.0015”. (R.) 
Syn.—C. commissurale, Bripisson. Raxsenuorst, Flora Europ. Algarum, Sect. III. p. 170. 
Hab.—In lacu. White Mountains, New Hampshire; (Dr. F. W. Lewis) 


Frond small, in f. v. one-third broader than long; constriction very deep, rounded ; segments 
narrow-reniform, with a central, somewhat truncate projection, produced by the continuation 
of the central inflation, rough on the inflation and on the extremities, with somewhat large 
pearly granules, e. v. three times longer than broad, constricted between the central inflation 

+ and the rounded extremities. Sporangium as in C. ornatum. (A.) 


Remarks.—I have seen but a single specimen of this species which differed from 
the typical form, in having the sinus very narrow in its outer portion, and in being 
shorter. 


Fig. 16, pl. 18, represents the frond of this specimen, magnified 750 diameters. 


Cc. cxlatum, Ratrs. 

C. suborbiculare, profunde constrictum; sinu angustissimo lineari; semicellulis inciso-crenatis, 
angulis rotundatis, a vertice medio nonnihil inflatis; cytiodermate granulato, granulis in 
series regulariter circulares positis. 

Diam.—Long. 132%y" = .0017”. Lat. phon” = .0014”. 

Syn.—C. czlatum, Raurs, British Desmidiee, p. 108. 

Hab.—In stagnis prope Aiken, South Carolina. (Ravenel.) 


Suborbicular, profoundly constricted; sinus very narrow, linear; semicells inciso-crenate, 
angles rounded, when seen from the end somewhat inflated in the middle; cytioderm granu- 
late, granules placed in circular series. 


Remarks.—This species was collected by Prof. Ravenel in a quiet ditch near 
Aiken, South Carolina, sparsely scattered amidst innumerable diatoms and desmids, 
The number of the crenations appears to vary. In the few individuals I have seen 
there were six end ones besides the two very broad basal ones, if the latter can be 
called crenatures. Ralfs gives six as the total number, and yet every one of his 
figures has many more. So I think the number a character of but little import- 
ance. The circular arrangement of the granules is not so positive and regular in 
the specimens I have seen, as is represented in the figure of Ralfs, otherwise the 


agreement is perfect. 


C. Broomei, Tuwaires. 

C. subparvum, plerumque tam longum quam latum, nonnunquam paulo longius, obtuse quad- 
rangulare, profunde constrictum, sinu angustissimo lineari ; semicellulis oblongo-quadrangulis, 
diametro duplo longioribus, angulis et inferioribus et superioribus obtuse rotundatis, ventre 
subplanis, dorso latissime truncatis et sepius leniter retusis vel plane convexis; cytioder- 
mate granulato-margaritaceo, granulis in seriebus subrectis collocatis. (R.) 


Long. 0.00194”—0.0022”. Lat. max. .002”, thick .0015”. 
Syn.—C. Broome, TuwaltTEs. RaALrFs, British Desmidiee, p. 103. 


Hab.—Georgia; Bailey. Prope Philadelphia ; Wood. 


134 FRESH-WATER ALG OF THE UNITED STATES. 


Frond in f. v. about as long as broad, constriction deep, linear; segments quadrilateral, ends 
straight, angles rounded, rough all over with minute granules; e. v. twice as long as broad, 
slightly inflated at the middle and rounded at the ends. Sporangium orbicular, smooth. (A.) 


Remarks.—The only specimens which I have seen were found in a brick-pond 
below the city in the month of June. They agree well with the descriptions, ex- 
cepting in that I should describe their central inflation as pronounced. ‘The sinuses 
also are ampliate or hollowed out within. ‘The granulations are quite large, and 
are arranged somewhat irregularly in rows. 

Fig. 15, pl. 13, is a view of the front of the frond magnified 460 diameters ; 
fig. 10, pl. 21, the outline of the lateral view. 


e. Cellule fusiformes, cylindrice vel ovales, in medio leviter constrictex. 


c. Cells fusiform, cylindrical, or oval, lightly constricted in the middle. 


Cc. Thwaitesii, Rarrs. 

C. mediocre, diametro bi-triplo longius, fusiformi-cylindraceum, medio leviter constrictum, am- 
bitu integerrimum, utroque polo rotundatum; semicellulis e cylindraceo subconicis, e medio 
in apicem sensim sensimque (sed modice) attenuatum; cytiodermate levi vel indistincte punc- 
tato. (R.) Species mihi ignota. 


Long. 0.00267”—0.00287". Lat. max. 0.0012”. (R.) 

Syn.—C. Thwaitesii, Raurs, British Desmidies, p. 109. 

Hab.—Florida ; Bailey. 

Frond in f. v. two or three times longer than broad; constriction a very shallow groove; seg- 


ments subcylindrical, with rounded ends ; endochrome scattered ; e. v. circular, or very slightly 
compressed ; e. f. not punctate, or puncta very indistinct. (A.) 


Cc. connatum, Brés. i 
C. validum, submagnum, leviter compressum, diametro duplo circa longius, subpanduriforme, 
plus minus constrictum, utroque polo late rotundatum, a vertice lato ellipticum ; semicellulis 
subhemisphericis, ambitu equabiliter rotundatis, integerrimis; eytiodermate punctato. (R.) 
Species mihi ignota. 


Long. 0.0035”. Lat. max. 0.00165”—0.0019”. (R.) 


Syn.— C. connatum, Brésisson. Ratrs,. British Desmidien, p. 108. 
Hab.—Florida; Bailey. 


Frond large, in f. v. about one-half longer than broad ; constriction shallow; segments about 
two-thirds of a circle, coarsely punctate, and with a distinct, sometimes striated, border; e. v. 
circular. (A.) 

d. Cellule in familias connexe. 

d. Cells united into families. 

C. Quimbyii, Woop. (sp. nov.) 
C. cellulis parvis, sub-ellipticis, medio profunde constrictis, in familias ecopulis hyalinis con- 


nexis; semicellulis a fronte ellipticis et diametro subduplo longioribus, a vertice ellipticis, a 
, D 


latere rotundatis; sinu lato; marsis chloro-phyllaceis in quaque semicellula singulis; cytio- 
dermate tenue, glabro. : 


Diam.—Long. zgy9" = 0.001". Lat. a fronte 4000 = 0.00075"; a latere izdoo” = 0.00042”. 
Hab.—In aquis puris, New Jersey. 


FRESH-WATER ALGA OF THE UNITED STATES. 135 


Cells small, subelliptical, profoundly constricted in the middle, joined by translucent bands into 
families ; semicélls seen from the front elliptical, and nearly twice as long as broad, from the 
vertex elliptical, from the side roundish ; sinus broad ; chlorophyl masses single in each cell; 
cytioderm thin, smooth. 


Remarks.—This plant was found by my friend Mr. Quimby growing in a beau- 
tiful spring above Camden, upon whose bottom it formed a gelatinous, trans- 
lucent, greenish mass. ‘The cells resemble in shape those of C. eucumis, although 
much smaller. They are joined by bands into little families, in which the original 
parent-cell is generally very distinct, it, or rather the two cells into which it first 
divides, remaining in the centre of the group. The bands are so hyaline that their 
edges can alone be distinctly seen, and hence the latter often look as though they 
were threads—there appearing to be two parallel threads, or two threads crossing 
one another, or a single thread, according as the band is flat, twisted, or on edge. 

It gives me great pleasure to dedicate the species to my friend Mr. Quimby, by 
whom it was collected. 

Fig. 9, pl. 1, represents one of the family groups of this plant. 


Genus EUASTRUM, Expres. 


Cellule vel oblonge vel elliptice, medio profunde incise, symmetrice sinuate, vel lobate, tumori- 
bus inflatis circularibus (rare obsoletis) instructe, utroque polo sinuato-emarginate vel inciso-bilo- 
bate, a vertice elliptice. 

Cells either oblong or elliptic, profoundly incised in the middle, symmetrically sinuate or lobed, 
provided with circular inflated protuberances (which are rarely absent), at each end sinuately emar- 
ginate or incisely-bilobate, from the vertex elliptic. 


A. Lobo polares in apice late sinuato-excist. 
A. Polar lobe with its apex broadly sinuately excised. 


E. multilobatum, Woop. 

E. magnum, fere duplo longius quam latum, medio profunde constrictum, et cum sinu modice 
amplo; a latere medio ventricosum et duplo biumbonatum, ad verticem dilatatum et emar- 
ginatum ; semicellulis a fronte trilobatis, lobis sinus amplissimis inter se sejunctis ; lobi basale 
distincte late emarginato, lobo centrale obtuso, lobo polare late leviter sinuato-emarginato ; 
semicellulis a vertice quinque lobulatis; cytiodermate levi. 


Diam.—Long. ySJ55" = 00475". Lat. 2% o” = 0025". 
Syn.—E. multilobatum, Woop, Proc. A. N. 8., 1869. 
Hab.—In Jacu ‘“‘Saco;” New Hampshire; (Lewis.) 


E. large, about twice as long as broad, in the centre profoundly constricted, with the sinus 

moderately large; from the lateral view somewhat enlarged and doubly biumbonate in the 

> middle; semicells from the front trilobate, the lobes separated by very wide sinuses, the basal 

lobe broadly emarginate, the central lobe obtuse, the end lobe broadly.and shallowly sinuately 
emarginate ; semicells from the vertex five-lobed ; cytioderm smooth. 


Remarks. —The basal lobes of this beautiful desmid are distinctly five lobulate, 
the lateral lobules being longer and broader than the others, which, instead of 
being emarginate, are obtuse. The sinuses, separating lobes and lobules, are very 
broad, with very obtuse angles. When the desmid is viewed from two-thirds 
round, so as to show the anterior and posterior lobules especially, it presents an 


136 FRESH-WATER ALG OF THE UNITED STATES. 


outline in which all the sinuses are of similar form, and the central and basal lobes 
are about equal size; whereas, when viewed from the front, the basal lobe is much 
the broader. When the desmid is viewed from the side it is seen to be enlarged 
in the centre, and provided with two distinct umbonations each side of the com- 


paratively narrow central sinus. 

Fig. 10, pl. 12, represents the front view of a frond of this plant; fig. 5, pl. 20, 
the outline of a two-thirds view, and fig. 5a, the outline of a lateral view, all mag- 
nified 450 diameters. 


E. verrucosum, Eure. 

E. magnum, late ovatum, vix longius quam latum, medio profunde constrictum, sinu extrorsum 
dilatato; semicellulis trilobatis, lobis triangularibus, divergentibus, apice late et profunde 
sinuatis; a latere ovato-oblongum, sinuato-lobatum, lobis octo in apice rotundatis, polaribus 
singulis porrectis, lateralibus ternis; cytiodermate granulato-verrucoso. (R.) Species mihi 
ignota. 

Long. 0.0036”—0039”". (R.) 

Syn.—E. verrucosum, EHRENBERG. RaBENHORST, Flora Europ. Algarum, Sect. ITI. p. 179. 

Hab.—South Carolina; Georgia; Florida; Rhode Island; Bailey. 

Frond somewhat longer than broad, rough all over with conic granules; segments 3-lobed, 
somewhat divergent, all the lobes broad, cuneate, with a very broad, shallow, or external 
sinus. Empty frond; f. v. segments with one large circular basal inflation on surface, one | 
smaller on each side, and two others on the end lobe; s. v. segments inflated at the base, 
narrowed into a short neck, end dilated with a central sinus; e. v. oblong, with three infla- 
tions at each side, one at each end, end lobe having 4 divergent lobelets. (A.) 


E. gemmatum, Brés. 

E. mediocre, diametro duplo longius, profunde constrictum, sinu angusto lineari, a vertice ovato- 
oblongum, ambitu sinuato-lobatum, lobis 8 conformibus, rotundatis ; semicellulis trilobatis, 
basi tumoribus 3 in seriem dispositis, lobis in apice profunde emarginatis, lobulis rotundatis, 
lobo polari dilatato et paulum producto; cytiodermate in tumoribus et lobulis granulato- 
punctato, ceterum levi. (R.) Species mihi ignota. 


Long. 0.00224”—0.0029". Lat. 0.00157’—0.0017”. (R.) 
Syn.—E. gemmatum, Brésisson. Rasennorst, Flora Europ. Algar., Sect. III. p. 180. 
Hab.—Rhode Island; Bailey. 


Frond scarcely twice as long as broad; segments 3-lobed, lateral lobes horizontal, deeply emar- 
ginate, the protuberances minutely granulate; end lobe dilated, its dilatations inclined 
upwards, and minutely granulate; ends with a deep rounded emargination. Empty frond 
slightly punctate ; f. v. segments with three granulate inflations near the base; tr. v. broadly 
elliptic, with three granulate inflations at each side and one at each end; e. v. end lobe cruci- 
form, lobelets rounded, granulate. (A.) 


. 


E. oblongum, (Grev.) Rats. ° 


E. magnum, diametro duplo triplove longius, oblongum, profande constrictum, sinu angusto, 
a latere oblongo-lanceolatum, utroque polo truncato leniter retusum, anitita undulato- 
sinuatum ; semicellulis (fronte) sinuato-quinquelobis, basi et in quoque lobo tumore instructis 
lobis lateralibus in apice dilatato sinuato-retusis, inferioribus latioribus quam superior. lobo 
polari late cuneato in apice profunde inciso, angulis omnibus totundatis, cytiodermate levi: 


zygosporis globosis verrucosis, verrucis obtuse conicis achrois hyalinis. (R.) Species mihi 
ignota. 


FRESH-WATER ALG OF THE UNITED STATES. 137 


Long. 0.0057"—0.0065". Lat. max. 0.00346”. 


Syn.—E. oblongum, (GREVILLE) Raxrs? British Desmidies, p. 80. 
Hab.—RBhode Island ; Bailey. 


Frond rather more than twice as long as broad, smooth, oblong; segments 5-lobed ; lobes nearly 
equal, cuneate; lateral lobes, or the basal only, with a broad, shallow, marginal concavity 
all their angles rounded, terminal notch linear. ; 

Empty frond; f. v. seg. punctate, with three large inflations, on surface near the base, two 
others above and two on terminal lobe; tr. v. three times as long as broad, with three sub- 
distant marginal inflations at each side, and one at each end, in 8, broader in proportion, 
more elliptic, and inflations cluse; e. v. end lobe notched at opposite external margins. 
Sporangium orbicular, beset with numerous conical tubercles. (A.) 


B. Lobi polares evidenter discreti et in apice anguste incist. 
B. End lobes evidently separated and narrowly incised in the centre. 


E. crassum, (Brés.) Krz. 

E. oblongum, diametro subtriplo longius, profunde constrictum, sinu angusto lineari, e vertice 
subquadrangulare, utroque polo profunde excisum, angulis rotundatis ; semicellulis (fronte) 
trilobis, basi et in quoque angulo tumore instructis, lobis lateralibus latissimis unisinuatis, 
lobo polari paullum prominente, in apice bifido, segmentis late rotundatis; cytiodermate dis- 
tincte punctato, punctis in series transversas ordinatis. (R.) 


Long. 0.0051”—0 0073”. Lat. max. 0.0041”. (R.) 


Syn.—E. crassum, (Brépisson) Kitzingc Rasennorst, Flora Europ. Algarum, Sect. III. 
p. 181. 


Hab.—United States. 


Frond about twice as long as broad, subquadrilateral, smooth; segments 3-lobed; basal lobes 
very broad, with a very broad, shallow marginal sinus, in which there is sometimes a slight 
intermediate rounded projection; end lobe creneate, rounded, terminal notch linear. 

Empty frond; f. v. punctate, segments with three inflations below and two above; tr. v. two or 
three times longer than broad, with three lobes or inflations at each side and one at each end; 
e. v. end lobe sinuate at opposite external margins. (A.) 


E. ornatum, Woop. 
E. oblongum, diametro duplo Jongius, profunde constrictum, sinu angusto lineari; semicellulis 
a fronte trilobatis; lobis basalibus latissimis, nonnibil sinuato-emarginatis, angulis plus minus 
productis et rotundatis; lobo polari medio profunde lineare inciso, segmentis late rotundatis ; 
semicellulis a latere bilobatis, lobis basalibus profunde emarginatis et cum angulis plus minus 
acutis; cytiodermate distincte ordinatim punctato. 


Diam.—z 3555" =. 00029”. 
Syn.—E. ornatum, Woop, Proc. A. N.S., 1869. 
Hab.—Saco Lake; New Hampshire. Lewis. 


E. oblong, twice as long as broad, profoundly constricted; semicells from the front trilobate ; 
basal lobe very ‘broad, slightly sinuately-emarginate, angles more or less produced and 
rounded; polar lobe medianly profoundly linearly incised, segments broadly rounded ; semi- 
cells bilobate at the sides, basal lobes profoundly emarginate and with the angles more or 


less acute; cytioderm distinctly regularly punctate. 


Remarks,—This species is close to E. crasswm, from which it differs in the pro- 
portionate length, being only twice instead of three times as long as broad; in the 
size being only three-fourths as large ; and especially in the peculiar lateral split- 


ting, as it were, of the basal lobes. 
1g July, 1872. 


138 FRESH-WATER ALGH OF THE UNITED STATES. 


Fig. 12, pl. 21, represents the front view of an empty half frond of this species, 
magnified 450 diameters; fig. 12a, the side view of an empty frond. 


E. affine, Raters. 

E. E. humerosum affine, paulo minus; semicellula quinquelobe ; lobi basales quales in EH. hume- 
rosum sed tumores quatuor in seriem transversam simplicem dispositi, lobi intermedii valde 
abbreviati eorumque basi tumoribus duobus instructi, lobus polaris magis porrectus et in 
apice minus dilatatus; cytioderma subtilissime punctatum subleve. (R.) 

Long. 0.0038”—0.0041”. (R.) 

Syn.—E. affine, Rars, British Desmidee, p. 82. 

Hab.—South Carolina; Georgia; Bailey. 

Frond about twice as long as broad; segments 3-lobed; basal lobes slightly emarginate, 
having intermediate between them and the end lobe on each side a tubercle representing 
middle lobes, the upper margin of which is horizontal; end lobe exserted, dilated, its notch 
linear. 

Empty frond; f. v. minutely punctate; the segments with four basal inflations, two above and 
two on end lobe; tr. v. elliptic, with four inflations on each side and one at each end; e. v. 
end lobe emarginate at opposite; e.v. end lobe emarginate at opposite external margins, 
producing four shallow lobulets. (A.) 


E. Didelta, (Turpin) RatFs. 

E. robustum, diametro duplo longius etiam supra, in sectione transversa ellipticum, ambitu un- 
dulato-crenatum, in utroque latere crenis quaternis ; semicellulis pyramidalibus, quinquelobis, 
tumoribus 9 in series tres alternantibus ordinatis, lobis inferioribus oblique truncato-rotundatis 
nonnunquam leniter retusis, intermediis subadscendentibus, rotundatis, lodo polari minus 
dilatato, bifido, segmentis rotundato-truncatis, conniventibus, in apice tumidis ; eytiodermate 
distincte punctato, punctis modo irregulariter sparsis modo in seriebus rectis collocatis. (R.) 


Long. 0.0055” Lat. 0.00279”. 
Syn.——E. Didelta, (Turpin) Ratrs, British Desmidee, p. 84. 
Hab.—South Carolina; Georgia; Rhode Island; Bailey. Pennsylvania; Wood. 


Frond rather more than twice as long as broad; segments pyramidal, inflated at the base and 
again at the middle, end scarcely dilated, rounded, its notch linear. 

Empty frond punctate; fv. segments with several inflations in lines and two at the end; tr. v. 
elliptic with four inflations at each side and one at each end; e. v. end lobe entire at margin. 
Sporangium orbicular, with subulate spines. (A.) 


Remark.—Fig. 13, pl. 21, represents this species. 


E. ampullaceum, Ratrs. 


E. diametro duplo longius ; semicellulis trilobis, ad basin tumidis, e basi latissima subito in lobi 
polaris collum attenuatis, lobis basalibus maximis integris, loco loborum intermediorum pro- 
cessu deutiformi, lobo polari cuneato, in apice bifido, segmentis late truncato-rotundatis ; 
cytiodermate subtiliter punctate. (R.) 


Long. 0.0035”—0.0038". Lat. max. .0026”; lat. in colli (lobi polar.) 0.00085”, (R.) 
Syn.—H. ampullaceum, Ratrs, British Desmidez, p. 83. 
Hab.—South Carolina; Florida; Bailey. 


Frond rather more than one-half longer than broad; segments obscurely 3-lobed, short, with 
broad inflated base ; basal lobes not emarginate, having on each upper side a small inter- 
mediate tubercle between each and the end lobe; end lobe exserted and dilated, its notch 


FRESH-WATER ALG#Z OF THE UNITED STATES. 139 


linear. Empty frond minutely punctate; f. v. narrow elliptic, with several inflated protube- 
rances, ends scarcely dilated, rounded; tr. v. with four inflations at sides and one at each 
end. (A.) 


Circulare, Hassa. 

E. mediocre, diametro duplo longius; semicellulis trilobis (at non semper distincte), ad basin 
versus tumoribus quinis aut pluribus in series duas v. tres alternantes ant singulo centrali, 
quaternis semicirculariter ordinatis instructis, lobis basalibus sinuato-emarginatis, subito in 
lobum polarem apice paullum dilatatum attenuatis; cytiodermate subtiliter punctato. (R.) 


Syn.—E. circulare, Hassau, Fresh-Water Alga, p. 383. 
Hab.—Providence, Rhode Island; Bailey. 


“Frond about twice as long as broad, tapering upwards into a neck, end not dilated, its notch 
an acute incision. Empty frond, segments with five basal inflations, four in a half circle 
around the fifth and two others at the extremity.” Archer. 


(Var. Ral fsii) 


Semicellula tumoribus minimis 11 in series tres alternantes ordinatis. 
Hab.—Saco Lake, New Hampshire; (F. W. Lewis) Wood. 


E. Jenneri, nobis. Frond scarcely twice as long as broad; segments 3-lobed, basal portions 
subquadrate, emarginate at the sides; end lobe, its notch linear. Empty frond punctate, 
segments with several inflations arranged in alternate lines. (Archer.) 


E. insigne, Hassat1. 
HE. subgracile, diametro duplo-triplove longius, a vertice fere quadratum, lateribus concavis, 
angulis rotundatis ; semicellulis basi inflatis, integris,e basi subreniformi in collum elongatum 
citius attenuatis, lobo polari dilatato bifido truncato; cytiodermate subtiliter punctato. (R.) 


Long. 0.0039”—0.0043”. Lat. max. 0.00236" (R.) 
' Syn.—ZE. insigne, Hassaut, Fresh-Water Alge, p. 21. 
Hab.—Florida; Rhode Island; Bailey. 


Frond rather more than twice as long as broad ; segments inflated at base, sides entire, without 
lateral tubercles, and tapering into a long slender neck; end lobe dilated, its notch linear. 
Empty frond minutely punctate ; f. v. segments with two inflations at the base ; f. v. narrower, 
gradually tapering to the end, which is considerably dilated; projections rounded, with a 
sinus between; tr. v. subquadrate, slightly concave at sides, with a rounded lobe at the 
centre of each end; e. v. end lobe with a sinus at opposite external margins, angles thus 
protruded into four divergent rounded lobelets. (A ) 


E. Ralfsii, Razena. 
E. mediocre, leviter compressum, medio inflatum, diametro duplo circiter longius; semicellulis 
pyramidalibus, e basi ventricosa in lobum polarem rectum truncatum sinuato-attenuatis ; 
cytiodermate subtiliter punctato, punctis in lineas rectas ordinatis. (R.) 


Syn.—E. ansatum, Eur. et auctores. Rapennorst, Flora Europ. Algarum, Sect. III. p. 184. 
E. Ralfsti, Rapenuorst, Flora Europ. Algarum, Sect III. p. 184. 
Hab.—South Carolina; Rhode Island; Bailey. White Mountains, New Hampshire (F. W 
Lewis). 
“E. ansatum, Ehrb. Frond about twice as long as broad; segments inflated at the base, taper- 
ing upwards without sinuations into a neck, end not dilated, rounded, its notch linear. Empty 


140 FRESH-WATER ALG& OF THE UNITED STATES. 


frond punctate; f. v. segments turgid on the surface, at the middle without circular inflations ; 
tr. v. elliptic, with a single large inflation at each side; e. v. end lobe entire at the margin, 
its divisions circular. (A.) 


Remarks.—I have seen only a very few specimens in a gathering made in Saco 
Lake, New Hampshire, by Dr. Lewis, which differ considerably from the typical 
form in the proportion of the breadth and length. There are also certainly four, 
if not more, umbonations on the face of each half-cell. ‘These are nowhere dis- 
tinctly spoken of as existing, and Mr. Archer states there are none visible in the 
front. view of E. ansatum. They are, however, represented in the side view of the 
original figure, and are said to be very noticeable by Mr. Archer himself, when 
the desmid is so looked at. In the Saco Lake specimens they are always seen in 
the front view with great difficulty, and in some cases I failed entirely to demon- 
strate them, so that they do not afford a good character for the indication of a new 
species. 

Fig. 1, pl. 18, represents a front view of a Saco specimen, magnified 450 dia 
meters, 

C. Lobi polares non-evidenter discreti. 
C. End lobes not evidently distinct. 


E. elegans, (Brés.) Krz. 

E. minus, oblongum, diametro duplo longius, utroque polo bifidum, segmentis introrsum rotun- 
datis; semicellulis sursum modice attenuatis, utroque margine laterali bi- vel tri- sinuatis, 
sinu superiori vel intermedio profundiori, sub polo utrinque dente acuto prominente; cytio- 
dermate subtiliter punctato, punctis irregulariter sparsis; zygosporis globosis aculeatis, 
aculeis elongato-subulatis. (R.) : 


Long. 0.0012".—0.002”. Lat. max. circiter 0.0011”. (R.) 


Syn.—E. elegans, (BRrépisson,) Ktrzina. Rasenyorst, Flora Europ. Algarum, Sect. III. p. 
185. 


Hab.—South Carolina; Georgia; Florida; Rhode Island; Bailey. White.Mountains, (F. W. 
Lewis). 


Frond minute, scarcely twice as long as broad, oblong; segments with their basal portion emar- 
ginate at the sides, connected by a broad neck with the terminal portion; ends protuberant, 
rounded, acutely emarginate at the centre, pouting; s. v. with an inflation at the base of the 
segments, sides concave, ends rounded. Sporangium orbicular, spinous. (A.) 


Remarks.—According to Prof. Rabenhorst FE. rostratum, Ralfs, which is noted 
as an American species by Bailey, is a variety of EH. elegans. Its peculiarities, ac- 
cording to Rabenhorst, are as follows: “Forma magis evoluta, profundior sinuata, 
segmentis polaribus latioribus, angulis acutis, dente paulo longiore.” 

Fig. 14, pl. 21, represents the outline of the frond as viewed laterally ; fig. 2, 
pl. 13, a front view of the frond, magnified 750 diameters. 


E. binale, (Turpin) Ratrs. 


E. minimum, diametro paulo vel subduplo longius, in sect. transversa oblongo-cylindricum, 
medio tumidum, utroque polo rotundatum; semicellulis indistincte trilobis, lobis basalibus 


FRESH-WATER ALG OF THE UNITED STATES. 141 


latis, rotundatis vel sinuato-bi- tricrenatis ; lobo polari abbreviato late truncato, leviter emar- 
ginato, angulis acutis lateraliter plus minus porrectis; cytiodermate subtilissime punctato. 


Syn.—E. binale, (Turpin) Ratrs, British Desmidew, p. 90. 
Hab.—Florida; Bailey. Rhode Island, (S. T. Olney,} Thwaites. Pennsylvania ; Wood. 


Frond very minute, scarcely twice as long as broad, oblong ; segments with their basal portion 
either entire or bicrenate at the sides, slightly contracted beneath the ends; ends dilated, not 
protuberant beyond the angles, its central notch acute, broad; tr. v. with two lateral infla- 
tions, ends truncate, angles rounded, (A.) 


Remark.—Fig. 3, pl. 18, represents the front view of a frond, magnified 750 
diameters. 


Genus MICRASTERIAS, Ag. (1827). 


Cellule compressa, profunde constrict, a fronte orbiculares vel late elliptice, a vertice fusiformes 
cum utroque polo acuto, semicellule tri- vel quinque-lobx ; lobi basales ant integri aut pluripliciter 
inciso-lobulati; lobus polaris aut integer aut sinuatus aut emarginatus, et interdum angulis produc- 
tus et bifidus. Cytioplasma chlorophyllacea in cellule lumen subequaliter distributa, granula 
amylacea sparsa involvens. Cytioderma plerumque leve, nonnunquam punctatum, granulatum vel 
mucronatuny, 

Zygospore globose, etate provecta aculeis simplicibus, apice bi- multi-fidis, nonnunquam repetito- 
multifiidis armate. 


Cells compressed, profoundly constricted, viewed from the front orbicular or broadly elliptic, from 
the vertex fusiform with acute ends. Semicells 3- or 5-lobed; basal lobes either entire or many 
times incisely-lobulate ; end lobe either entire or sinuate or emarginate, and sometimes with its angles 
produced and bifid. Chlorophyllous cytioplasm distributed nearly uniformly in the cavity of the 
cell, surrounding seattered starch granules. Cytioderm mostly smooth; sometimes punctate ; 


granulate or mucronate. 
Zygospores globose, at maturity armed with simple spines, whose ends bifid or multifid, and some- 
times repeatedly multifid. 


A, Semicellule trilobe. Lobi basales horizontales ; lobus polaris valde dilatatus, dorso plane 
converus, truncatus vel leviter retusus, a lobis basalibus sinu amplissimo discretus. 

A. Semicells trilobate. Basal lobes horizontal ; end lobe strongly dilated, with the back con- 
vex, truncate, or slightly retuse. 


M. arcuata, Batey. 

M. mediocris, quadrangularis, paulo latior quam longa, profunde pinnatifida; lobis basalibus 
angustis elongatis, arcuatis, in apicem acutum attenuatis, divergentibus; lobis polaribus 
angustusimis, utrinque graciliter productis, in apicem acutum attenuatis, in medio dorso 
modice retusis. (R.) 

Syn.—U. arcuata, BatLey, Microscopical Observations; Smithsonian Contributions, vol. ii 


Hab.—In stagnis. Florida; Bailey. 
“ Quadrangular, segments three-lobed, the basal lobes long and arcuate, subtended by the trans- 
verse projections from the ends of the slightly notched terminal lobes.” (Bailey.) 


M. expansa, BatLey. 
M. mediocris, tam longa quam lata, lobis stellatim expansis; lobis basalibus angustis in apicem 
acutum attenuatis, divergentibus, rectis; lobis polaribus e basi angusta sensim dilatatis, in 
medio dorso late sinuatis, angulis acutis (sed muticis). (R.) 


Syn.—M. expansa, Bartey, Microscopical Observations: Smithsonian Contributions, vol. ii. 


Hab.—In stagnis, Florida; Bailey. 


142 FRESH-WATER ALGA OF THE UNITED STATES. . 


Segments three-lobed, basal lobes long, subconical, acute; termina. lobes slender, forked at the 
end, with the divisions much shorter than the basal lobes. (Bailey.) 


ME. quadrata, BarLey. 
M. arcuate similis, sed duplo major, semicellularum lobi basales minus arcuati, basi inflati, 
apice bidentati et cytioderma irregulariter granulatum. (R.) 
Diam.—0.0043”"—0.0049”". 
Syn.—WM. quadrata, BatLey, Microscopical Observations: Smithsonian Contributions, vol. ii. 


Large quadrangular, three-lobed, basal lobes elongated, slightly curved, bidentate ; terminal 
lobes with two slender transverse bidentate projections. Bailey. 


M. disputata, Woop. 

M. magna, fere tam longa quam lata, subpinnatisecta, sinu acuto, lobis equalibus ; semicellulis pro- 
funde trilobis, lobis basalibus in apicem acute bidentatum valde attenuatis; lobo polari valde 
dilatato, dorso rotundato, angulis lateralibus acutissimis. 

Long. 7335" =.005”. Lat. 7295” = .004”. 

Syn.—WMicrasterias incisa, Krz. BatLey, Microscopical Observations: Smithsonian Contribu- 

tions, 1850. . 


Haud Micrasteria incisa, Kitzine, Spec. Algarum, p. 171. * 
Tetrachastrum Americanum, ARCHER, PRiTcHARD’s Infusoria, 1860, p. 725. 


Hab.—South Carolina; Georgia; Florida; Rhode Island; Bailey. Pennsylvania ; Wood. 
M. large, about as long as broad, subpinnatisected; sinuses acute; semicells profoundly trilo- 


bate; basal lobes strongly attenuate into the acutely bidentate apex; distal lobes strongly 
dilated, rounded, with their lateral angles bidentate ; end lobe broadly dilated, lateral angles 


very acute. 


Remarks.—This desmid was first figured by the late Prof. Bailey in his Micro- 
scopical Observations (Smithsonian Contributions), as M. incisa of Ktz., and Ra- 
benhorst, in his Flora Europea Algarum, confirms this identification. He has 
probably, however, never seen the plant itself, but merely accepts the opinion of 
Professor Bailey. Mr. Archer (Pritchard’s Infusoria), thinks the American plant 
is certainly distinct from the European, and this seems to me correct. The points 
of difference are—the American form is nearly twice the size of the European, the 
sinuses are much more widened outwardly, and the lobes are reduced rapidly in 
breadth to a mere point at the end, the dorsum of the distal lobes is also, I believe, 
more rounded. In his description of 7. Americanum, as he calls it, Mr. Archer 
states the end lobe has its angles bidentate. In the only specimen I have seen, 
the angles end in a very sharp, almost spine-like point. Dr. Leidy found the spe- 
cies abundantly at Newport, Rhode Island, and his figure agrees with mine in this 
respect. In regard to the name, as there is already an M. Americanum, the specific 
name of Archer cannot be adopted, and for a similar reason it would not do to call 
it M. Baileyi. I have then been forced to give it a new title. 

Fig. 4, pl. 13, was drawn by myself from the single specimen I have seen; fig. 
4 a was drawn by Dr. Leidy from a Newport specimen. 


M. oscitans, Raxrs. 

M. magna, pene tam longa quam lata, subpinnatisecta, a vertice elliptico fusiformis, utroque 
polo bifida; lobis basalibus horizontalibus conico-productis, apice bifidis; labo polari a lobis 
basalibus sinu amplo ac rotundato discreto, plus minus convexo, haud raro truncato, rarius 
leviter retuso, utrinque producto acuminato, plerumque bidentato. (R.) 


‘ FRESH-WATER ALGH OF THE UNITED STATES. 143 


Diam.—0.0047". Long. 0.0039”. (R.) 


Syn.—. oscitans, Raxrs, British Desmidiee, p. 76. Rasennorst, Flora Europ. Algarum, 
; Sect. III. p. 119. 
MM. pinnatifida Krz. Raxenuorst, Flora Europ. Algarum, Sect. III. p. 119. 


Hab.—Florida; Rhode Island; Bailey. 


Frond about as broad as long, pinnatifid; lateral lobes separated from the terminal by arounded 
sinus, horizontal, conical, their extremities bidentate ; end lobe short, broad, its lateral pro- 
jections short, conical, usually bidentate, narrower and shorter than the lateral lobes; ends 
convex at the centre; tr. v. fusiform, e. f. punctate. (A.) 


Remarks.—According to Prof. Rabenhorst M. pinnatifida, Ktz., is a variety of W. 
oscitans, different from the typical form only in being smaller, and in having the 
lobes narrower. 


B. Semicellulz 3-vel 5-lobe, plerumque radiatim inciso-lobulate. Lobi basales assurgentes 
aut non aut minus a lobo polari remoti, 


B. Semicells 3, or 5-lobate, mostly radiately incisely lobulate. Basal lobes assurgent, either 
close to, or but slightly remote from the end lobes. 


* Semicellulz trilobe. 
* Semicells trilobate. 


M. Americana, (Exuzs.) Krz. 
M. magna, oblonga, subpinnatiseeta, lobis polaribus paulum remotis, pene duplo longior quam 
lata; cytiodermate spinuloso unde laborum margines dentato-serrati conspiciuntur ; cellula 
e latere conspecta oblonga, in medio leviter constricta. wtroque polo bicornuta; semicellule 
basi tumore plus minus distincto instructe, fere quinquelobe, lobis basales latissimi iisdemque 
profunde bilobati, lobulis late excisis, segmentis dentato-serratis; lobis polaribus plus minus 
productis, in medio late excisis, segmentis profunde bifidis. (R.) 


Diam.—0.0041”. Long. circa 0.0051”. (R.) 
Syn.—M. Americana, Kirz1na. Rapenuorst, Flora Europ. Algarum, Sect. IIT. p. 189. 
Hab.—In stagnis, South Carolina; Florida; Bailey. 


Frond angular elliptic, more or less punctate; segments 3-lobed ; lateral lobes broad, cunéate, 
their margins concave, inciso-serrate ; and lobe broad, cuneate, end exserted, bipartite at the 
angles, the subdivisions narrow, and minutely dentate at the extremities ; end concave. (A.) 


Remark.—Fig. 17, pl. 12, represents a plate of this species. 


M. Baileyi, Ratrs. 

M. parva, oblonga, granulata; semicellulis trilobis, lobis basalibus a lobo polari sinu amplo 
discretis, excisura acute triangulari in duas lacinias partitis, laciniis e basi latiori in apicem 
truncatum bidentatum attenuatis; lobo polari e basi angusta Jonge porrecto, sursum valde 
dilatato, in vertice leviter et late sinuato, angulis truncato, bidentato. (R.) 


Syn.—M. Baileyi, Raurs, British Desmidiew, p. 211. 
Hab.—New York; Rhode Island; South Carolina; Florida; Bailey. 


Frond granulated; segments three-lobed ; lobes bipartite, end one much exserted. (Ralfs.) 


M. ringens, Batey. 
M. mediocris, oblonga, margine granulata; semicellulis trilobis; lobis lateralibus bipartitis, 
laciniis divaricatis, apjce obtusis, truncatis vel bidentatis; lobo polari e basi angusta sursum 
valde dilatato, exserto, in vertice leniter sinuato, angulis truncato. (R.) 


144 FRESH-WATER ALGH OF THE UNITED STATES. 


Syn.—M. ringens, BAILEY, Microscopical Observations, pl. 1, fig. 11: Smithsonian Contri- 
butions, vol. ii. 
Hab.—Florida; Bailey. 


Oblong, segments three-lobed, coarsely granulated near the edge ; basal lobes subdivided by a 
deep notch into two rather broad and obtuse or slightly bidentate projections ; terminal lobes 
exserted, emarginate; extremities bidentate or obtuse. 


* * Semicellule quinque-lobate. 
* * Semicells 5-lobed. 


Mi. truncata, (Corp4) Bres. 

M. magna, orbicularis, aut levis aut subtiliter punctata ; semicellulis quinquelobis, lobis inter 
se sinu obtusangulo subangusto discretis, basalibus et intermediis inciso-lobulatis, segmentis 
acute bidentatis; lobo polari late cuneato, in dorso truncato, modo leviter convexo, modo 
leviter retuso, angulis aut bidentatis aut integris. (R.) 

Diam.—0.003" Long. .0036”. 

Syn.—W. truncata, (Cornpa,) Brupisson. RaBENHORST, Flora Europ. Algarum, Sect. ITI. p. 

191. 


Hab.—Georgia; Florida; Rhode Island; Bailey. Pennsylvania; Wood. Rhode Island 
(S. T. Olney); Thwaites. : 


Frond orbicular, smooth; segments 5-lobed; basal and middle lobes obscurely bipartite, ex- 
tremities bidentate ; end lobe very broadly cuneate, bidentate at the angles, and with a slightly 
central concavity. (A.) 


Remarks.—The dimensions.given above were taken from the largest specimens 
I have seen, but do not at all equal those given, by Prof. Rabenhorst, his breadth 
is 0011”. According to the same authority, I crenata, Bréb., is merely a variety 
of this species. 

Fig. 15, pl. 21, represents the outline of a frond of this plant. 


M. furcata, Aa. 

M. permagna paulo longior quam lata, levis; semicellulis quinque lobis (pene 7-lobis) ; lobis 
omnibus rectis; lobis basalibus angustioribus, bilobulatis, lobulis bifidis, sinu obtusangulo 
vel acutangulo, segmentis linearibus bidentatis (denticulis sepe inequilongis); lobis inter- 
mediis duplo latioribus, inciso-bilobis, lobulis iisdem ac loborum basalium; lobo polari non- 
nihil anguste cuneato, prominulo, in apice plus minus profunde sinuato-vel undulato inciso, 
angulis bidentatis. 

Diam.—7z 335" = 008". 

Syn.—. rotata, Raurs, British Desmidiew, p. 71. 

Mf. furcata, Acanpu. Rasennorsr, Flora Europ. Algarum, Sect. III. p. 191. 


Hab.—South Carolina; Georgia; Florida; Rhode Island; Bailey. New Jersey; Wood. 


M. very large, a little longer than broad, smooth; semicells 5-lobed (scarcely 7-lobed) ; lobes 
all straight ; basal lobe narrower than the intermediate, bilobulate, lobules bifid, their ainuaes 
acute or obtuse, segments linear, bidentate ; teeth often long and unequal ; Sitetnadiata lobes 
twice as wide as the basal, bilobate, their lobules of the same form as fhe basal lobe; end 


lobes narrowly cuneate, prominent, more or less profoundly si 
sinuatel 
the apex, angles bidentate. a a 


Remarks.—According to Rabenhorst and others, there is a European form of 
this species in which the marginal teeth are wanting. This may exist in this 


FRESH-WATER ALGA& OF THE UNITED STATES. 145 


country, but I have never met with it. All the specimens which have come under 
my notice were obtained in “Shepherd’s Dam,” near Greenwich, Cumberland 
County, New Jersey. None of them were as large as the maximum of the European 
measurements of which Rabenhorst gives 0.0109” as the diameter. 

Fig. 5, pl. 13, represents a frond of this species, magnified 260 diameters. 


M. denticulata, Bris. ? 


M. permagna, paulo longior quam lata, levis; semicellulis quinquelobis (pzne 9 lobis) ; lobis 
intermediis et basalibus simillimis, bilobatis, lobulis item in lobulis bifidis duobus divisis ; 
lobo polare angusto, cuneato, in apice plus minus inciso; margine minute denticulato. 


Diam.—Lat. .0092”. Long. .011.” 
Syn.—. denticulata, Br&pisson. Rars, British Desmidiee, p. 70, et ARCHER, PRITCHARD’S 
Infusoria. 
MM. denticulata, Brksisson.? Rasenuorst, Flora Europ. Algarum, Sect. IIT. p. 192. 
Hab.—Pennsylvania; Wood. Florida; Bailey. 


Very large, a little longer than broad, smooth; semicells with five lobes (scarcely 9); basal 
and intermediate lobes alike bilobate, lobules also divided into two bifid lobules; end lobe 
narrow, wedge-shaped, more or less incised at its apex; margin minutely denticulate. 


Remarks.—Prof. Rabenhorst gives M. denticulata, Bris. as merely a variety of 
MU. furcata,; AG., stating that it only differs from the latter in the marginal incisions 
and teeth. Not having access to the original description of Brébisson I cannot 
express an opinion as to whether Prof. R. is correct or not, but the specimen from 
which the above description was drawn up (and which is figured on plate 13) cer- 
tainly differs from I furcata very essentially in the arrangement of its lobes, and 
is, I feel confident, If denticulata, Bris. of RALFs and ARCHER. 

Fig. 6, pl. 13, is a drawing of this plant, as seen by myself, magnified 260 
diameters, 


M. radiosa, Aa. 
M. maxima, orbicularis, levis, antecedenti simillima, differt inprimis segmentis ultimis tumidis 
in apicem bi-tri-fidum attenuatis, lobo polari vix prominulo, apice sinuato, ad utrumque 
angulum bi-tri-dentato. (R.) Species mihi ignota. 


Diam.—0.0076”. (R.) 
Syn.—WM. radiosa, AGARDH. RaxBeEnunorst, Flora Europ. Algarum, Sect. III. p. 192. 
Hab.—Florida; Bailey. 


Frond orbicular, smooth ; segments 5-lobed; basal lobes twice, middle lobes generally thrice 
dichotomous, ultimate subdivisions inflated, attenuate towards the end, bidentate; end lobes 
emarginate, its angles dentate. (A.) 


M. fimbriata, Ratrs. 

M. magna, orbicularis, levis (nonnunquam superficie aculeis singulis sparsis); semicellulis 
quinquelobis, lobis omnibus confertis, basalibus angustioribus, repetito bilobulatis, lobis inter- 
mediis duplo latioribus, repetito-bilobulatis, lacinulis extremis leviter emarginatis, in angulis 
spinis elongatis armatis; lobo polari prominulo, in apice obtuse sinuato- vel- undulato-emar- 
ginato, angulis lateralibus rotundatis, ad marginem superiorem spinis singulis vel geminis 
obsito (rarius nudo). (R.) Species mihi ignota. 

19 August, 1872. 


146 FRESH-WATER ALG OF THE UNITED STATES. 


Diam.— 0051”—.0078". (R.). 


Syn.—H. fimbriata, Rares, British Desmidiex, p. 71, et RaBENHOoRST, Flora Europ. Algarum, 
Sect. IIL. p. 193. . 


Hab.—South Carolina; Florida; Bailey. 


Frond orbicular, smooth; segments 5-lobed, basal lobes twice, middle lobes thrice dichotomous; 
ultimate subdivisions acutely bidentate; end lobe very slightly exserted, its angles very 
slightly produced, bidentate, ends emarginate. In transverse view is seen an inflated pro- 
tuberance just over the central isthmus, which may possibly exist in other species of Micras- 
terias. (A.) 


M. papillifera, Bris. 

M. orbicularis, superficie levis, margine extremo dentato papillifera; semicellulis quinquelobis; 
lobis basalibus et intermediis equilatis, bilobatis ; lobulis bifidis, laciniis linearibus bidentatis, 
déntibus papilliferis; lobo polari vix prominulo, in apice sinuato, angulis et margine dentato- 
mucronatis. (R.) Species mihi ignota. 

Diam.—0.0045”. (R.) 

Syn.—W. papillifera, Br&pisson. Ratrs, British Desmidiex, p. 72, et RaBENHoRsT, Flora 

Europ. Algarum, Sect. IIL. p. 194. 

Hab.—Florida; Rhode Island; Bailey. 


Frond orbicular, having the principal sinuses bordered by a row of minute granules, otherwise 
smooth ; segments 5-lobed; basal and middle lobes twice dichotomous, their ultimate shal- 
low subdivisions terminated by two, sometimes three, gland-like teeth ; end lobe emarginate, 
its angles dentate. Sporangium as in M. denticulata, but considerably smaller. (A.) 


M. granulata, Woop (sp. nov.) 

M. magna, suborbicularis, arcte granulata ; semicellulis quinquelobis, lobis inter se sinu angusto 
discretis, basalibus et intermediis plerumque integris, lobo polari supra valde dilatato, in 
dorso medio leviter retuso ; marginibus valde crenatis. 

Diam.—Long. 535” = .0048”". Lat. ys4355" = .0036”. 

Hab.—South Carolina, (Ravenel) 

Large, suborbicular, closely granulate; semicells 5-lobed, lobes separated by narrow sinuses; 


basal and intermediate lobes mostly entire; end lobe distally broadly dilated, broadly and 
very shallowly emarginate; margin of frond strongly crenate. 


Remarks.—The only specimens of this species that I have seen were collected by 
Prof. Ravenel in a shallow ditch near Aiken, South Carolina, where they formed a 
greenish, gelatinous mass, with numerous desmids and diatoms. It is most closely 
allied to M. truncata, from which it is separated by its entire lateral lobes, by its 
granulated surface, and its crenated margins. It also does not apparently attain 
as large a size as that species. The granules are very small in the central portion 
of the frond, but become larger as they approach the margin, 


Fig. 16, pl. 21, represents an empty frond of this species, magnified 460 diam- 
eters. 


M. Jenneri, Ratrs. 


M. magna, oblonga, plerumque subtiliter granulata; semicellulis quinquelobis; lobis basalibus 
et intermediis equilatis, confertis, cuneatis, bilobulatis; lobo polari Jate truncato vel late 
rotundato, in medio interdum leviter et obtuse emarginato, interdum nonnihil profunde emar- 
ginato. 


Diam.—Lat. 7§35’—r9'e'56" = .006”—.0062". Long. Tho —ri0o” = .0062"—.0087”, 


FRESH-WATER ALG OF THE UNITED STATES. 147 


Syn.—M. Jenneri, Ratrs, British Desmidiex, p. 76. 
Hab.—Prope Philadelphia; Wood. South Carolina; (Ravenel) 
Large, oblong, for the most part finely granulate ; semicells 5-lobed ; lobes wedge-shaped ; basal 


and intermediate, about equally broad; end lobe broadly truncate or broadly rounded, in the 
middle sometimes slightly and obtusely emarginate, sometimes rather deeply emarginate. 


Remarks.—I have found this species near Philadelphia, and also received it from 
‘Prof. Ravenel, by whom it was collected in South Carolina. The American plant 
differs from the typical form 1 not having the ultimate lobules emarginate, they 
being merely a little hollowed out in the centre, and sometimes scarcely this. The 
angles in some specimens are also more acute. Mr. Archer, however, speaks of a 
variety occurring in England, in which these lobules are not emarginate, and I do 
not think characters can be found separating the American from the European 
forms. The median suture is in all the specimens very narrow and deep, a mere 
line, as it were, extending nearly to the centre. 

Fig. 7, pl. 18, represents a frond of this species. 


Mi. Torreyi, Bariey. 

M. permagna, oblongo-orbicularis, levis, profundissime lobata; semicellulis quinquelobis, lobis 
basalibus profunde bifidis, laciniis inferioribus apice bidentatis, superioribus integris, lobis in- 
termediis profunde trifidis, laciniis superioribus bidentatis, inferioribus integris, lac. omnibus 
lanceolatis acuminatis, inferioribus paulum incurvis, superioribus recurvis ; lobo polari non 
prominente, e basi angusta seusim dilatato, in vertice acute sinuato, angulis integris acumin- 
atis. (R.) Species mihi ignota. 

Syn.—M. Torreyi, Batuny. Raxrs, Brit. Desmidiex, p. 210. 

Hab.—Prope Princetown, New Jersey; Bailey. 

Frond smooth ; segments 5-lobed ; basal lobes bifid, middle lobes trifid, the subdivisions nearest 
the opposite segments and those nearest the terminal lobe bidentate at the apex; the inter- 
mediate three terminating in acute points; all somewhat inflated and tapering; terminal 
lobe narrow, not exserted, spreading at the angles into divergent tapering points, ends 
slightly emarginate. (A.) 


M. foliacea, Barrey. 

M. parva, subquadrata, levis; semicellulis trilobis, lobis lateralibus profunde bifidis (unde rec- 
tior semicell. quinquelobe), lobulis inequaliter inciso-dentatis, lobulis inferioribus rectis, 
superioribus recurvis; lobo polari plus minus prominente, anguste cuneato, in vertice plus 
minusve emarginato, angulis aut acutis integris aut productis, bidentatis. R. Species mihi 
ignota. 

Syn.—M. foliacea, Battey. Ratrs, British Desmidiex, p. 210. 

Hab.—‘‘ Worden’s Pond, Rhode Island; Bailey.” 

Frond subquadrate, smooth; segments 3-lobed; lateral lobes deeply bipartite, inciso-dentate, 
their margins concave, inciso-serrate; end lobe broad, cuneate, and exserted, bipartite at the 
angles, the subdivisions narrow, and minutely dentate at the extremities ; end concave. (A.) 


Genus STAURASTRUM, Meven. 


Cellule libere natantes, in medio plus minus profunde constricte ; semicellule a vertice 3-6 angu- 
lares vel radiate. Cytioderma aut leve aut punctatum aut verrucosum aut aculeatum, nonnunquam 
ciliis vel pilis obsessum. 

Cells swimming free, more or less profoundly constricted in the middle; semicells when seen 
from the vertex 3 to 6 angular or radiate. Cytioderm either smooth or punctate, or verrucose or 
aculeate, sometimes covered with hairs or cilia. 


148 FRESH-WATER ALG OF THE UNITED STATES. 


A. CYTIODERMA LA&VE VEL RARISSIME SUBTILITER PUNCTATUM. 
CYTIODERM SMOOTH OR VERY RARELY VERY FINELY PUNCTATE. 
1. Semicellularum anguli rotundati. 
Angles of the semicells rounded. 


St. muticum, Brés. 

St. a fronte orbiculare, leave, profunde constrictum, nudum, vel muco plus minusve firmo invo- 
lutum ; semicellulis ellipticis, a vertice conspectis 3-4 angularibus (rarius quinquangularibus) 
angulis rotundatis, lateribus leviter sinuato-retusis; zygosporis aculeatis, aculeis elongatis, 
subulatis, furcatim fissis. (R.) Species mihi ignota. 

Diam.—0.0013"”—0.000147”. (RB.) 

Syn.—S. muticum, Bripisson. Rasenuorst, Flora Europ. Algar., Sect. III. p. 200. 

Hab.—Scuth Carolina; Rhode Island; Bailey. 


Segments inf. v. elliptic, smooth, without spines;.e. v. with three or four broadly rounded 
angles, sides concave. Sporangium beset with numerous elongate somewhat stout spines, 
forked at the apex. (A.) 


St. orbiculare, (Exzsz.) Raters. 
St. suborbiculare, leve, sepius muco matricali involutum; semicellulis divergentibus, semi_ 
orbicularibus, dorso nonnunquam elevatis, angulis plus minus late rotundatis, lateribus plus 
minus sinuato-retusis; zygosporarum aculeis elongatis, subulatis, integris. (R.) 


Diam.—.002"". 


Syn.—St. orbiculare, (EuRB.) Raxrs, British Desmidiex, p. 125. RapBennorst, Flora Europ. 
Algarum, Sect. III. p. 200. 


Hab.—Rhode Island; Bailey. Pennsylvania; Wood. Rhode Island; (S. T. Olney) Thwaites. 


- Segments in f v. semiorbicular, smooth, without spines; e. v. with three broadly rounded angles, 
sides slightly concave. (A.) 


Remarks.—Fig. 17, pl. 21, represents the outline of the end view of a frond of 
this species. Fig. 8, pl. 13, is a drawing of the front view of a living frond. 


2. Semicellularum anguli mucronati vel aristatt. 
Angles of the semicells mucronate or bristly. 
St. longispinum, (Battery) Arcner. 


St. magnum triangulare, leve, angulis in aculeos geminos validés subulatos longe productum, 
lateribus subplanum. (R.) Species mihi ignota. 


Syn.—Didymocladon longispinum, BaiLey, Microscopical Observations, 
Hab.—Florida; Bailey. 


“Large, smooth, triangular, with two long spines at each angle.” Bailey. 


St. dejectum, Brésztsson. 

St. leve, parvum, sinu amplo, obtusangulo (vel acutangulo); semicellulis ellipticis (vel subtri- 
angularibus), dorso nonnihil convexo, utroque fine in aculeum achroum rectum vel varie cur- 
vatis productis; a vertice triangularibus (vel quadrangularibus), angulis sepe rotundatis 
aculeo interdum obsoleto imposito. 


Diam.—Lat. 73$0’ —rec's0 = -0008"—.001”. Long. y3955"—r3259” = .0008"”—. 0001", 


Syn.—Staurastrum dejectum, Brisisson. RaBentiorst, Flora Europ. Algarum, Sect. III. 
p- 208. 


‘FRESH-WATER ALGA OF THE UNITED STATES. 149 


Hab.—South Carolina ; (Ravenel) Wood. 


Smooth, small; sinus ample, obtuse angled (sometimes acute angled ?); semicells elliptic (or 
subtriangular ?), with the dorsum slightly convex, at the angles with a straight or curved 
transparent spine; from the vertex triangular (or quadrangular ?), angles often rounded, 
with a sometimes obsolete spine superimposed. 


Remarks.—This species was collected near Aiken, South Carolina, by Prof. 
Ravenel, who found it forming with various diatoms and desmids a slimy mass in 
a feebly running ditch. It agrees very well with the European form, except that 
it is not so large (at least the largest I ever measured did not come up to the 
size of their transatlantic brethren), neither does it appear to vary quite so much. 
In the description, I have placed in brackets those characters in which the European 
form varies, and the specimens I have seen do not. 

Fig. 18, pl. 21, represents outline of end of a semicell, magnified 750 diameters. 
Fig. 9, pl. 13, a front view, and 9 a the end view, of the living frond, magnified 

diameters. 


. 


St. aristiferum, Raters. 

St. lave, St. cuspidatum quodammodo simile, et eadem magnitudine sed isthmo destitutum ; 
semicellulis tumidis, in media parte subrotundatis, lateraliter in lobum, basi constrictum, 
apice aristatum productis, lobis divergentibus, a vertice tri-quadrilobo-radiatis, radiis strictis 
squidistantibus cruciatim dispositis, interstitiis profunde excisis. (R.) Species mihi ignota. 

Diam.—Incl. arist. 0.0014". (R.) = 

Syn.—St.aristiferum, Raurs, British Desmidiee, p. 123. RaBennorst, Flora Europ. Algarum, 

Sect. III. p. 204. 

Hab.—Georgia ; Rhode Island; Bailey. 


Segments smooth, in f. v. prolonged at each lateral extremity into a mamillate projection, which 
is terminated by a subulate, acute straight awn, the awns divergent, e. v. with three or four 
angles; angles inflated mamillate, terminated by an awn, sides deeply concave in the centre. 


(A.) 
St. Lewisii, Woop. 
St. leve; sinu amplissimo, spinulo parvo armato et cum angulo obtuso; isthmo nullo; semi- 


cellulis a fronte late triangularibus, a vertice triangularibus et cum angulis nonnihil tumidis, 
et rotundatis; angulis spino maximo, robusto, acuto armatis. 


Diam.—Long. cum. spingg}y” = .0025”; lat. cum. spin. yyy" = -00225". Sine spin. : long. 
gin” =-001666"; lat. 3355”  .001666". Spin.: long. 73455” = .000666” 

Syn.—St. Lewisti, Woop, Proc. Acad. N. 8. 1870. 

Hab.—In lacu Saco; (Lewis) Wood. 


Smooth, with a very ample sinus, which is armed with a small spine and has a very obtuse 
angle; isthmus absent ; semicells from the front broadly triangular, from the vertex trian- 
gular, with the angles somewhat tumid and rounded; angles armed with a very large acute 
robust spine. 


Remarks.—This desmid is most closely allied to St. aristiferum, Ralfs, but differs 
from it in outline as seen from the front, there being no mamellation of the ends. 
The spines in the sinuses are always wanting in the European species. 

Fig. 19, pl. 21, represents the outline of the end of a semicell, magnified 750 
diameters. Fig. 11, pl. 13, represents the perfectly formed frond, magnified 750 
diameters. 


150 FRESH-WATER ALGZ OF THE UNITED STATES. 


B. CYrIoDERMA GRANULATUM VEL VERRUCOSUM. 
CYTIODERM GRANULATE OR WARTY. 

1. Semicellule a vertice 3~1 angulares; anguli plus minus radiatim elongati. 
Semicells seen from the vertex 3-1 angled; angles more or less radiately produced. 


St. margaritaceum, Exrs. 

St. mediocre, granulatum; semicellulis convergentibus, subfusiformibus, in medio tumidis, 
utrinque productis, truncatis, a vertice orbicularibus, 5-7 radiatis, radiis obtuse truncatis 
achrois, hyalinis, granulato-margaritaceis. (R.) Species mihi ignota, 

Diam.—0.00135"—0.0017". (B.) 

Syn.—St. margaritaceum, (EHRB.) MENEGHENI. Rapennorst, Flora Europ. Algarum, Sect. 

III. p. 206. 
Hab.—South Carolina; Georgia; Florida; Rhode Island; Bailey. 


Segments in f. v. gradually widening upwards, rough with pearly granules, outer margin con- 
vex, produced at each side into a colorless, more or less attenuate, short precess, having the 
granules in transverse lines, blunt and entire at the apex, e. v. circular, bordered by from five 
to seven short, narrow, obtuse, colorless, granulate marginal rays. (Archer. ) 


St. dilatatum, Exzs. 
St. parvum, granulatum ; semicellulis rectis, cylindrico-fusiformibus, non tumidis, utroque fine 
obtusis vel subtruncatis, a vertice 8-4-5 radiatis, radiis latioribus, truncatis vel rotundatis, 
achrois, hyalinis, granulato-margaritaceis. (R.) Species mihi tgnota. 


Diam.—0.0008"—0.0011”. (BR) 


Var. alternans. 
Semicellulis ellipticis rectis, utroque fine rotundatis, a vertice triradiatis, radiis obtusis, alter- 
nantibus cum semicellule inferioris. (R.) 


Var. tvicorne. 
Semicellulis fusiformibus, nonnunquam in medio subtumidis, haud raro isthmo distincto con- 


junctis, a vertice 3-4 angularibus, angulis truncatis vel obtusis, plus minus radiatim pro- 
ductis. (R.) 


Hab.—Georgia; Florida; Rhode Island; Bailey. 


Syn.—S. aliernans, Brésisson. Var. alternans et tricorne. Rasenuorst, Flora Europ. 
Algarum, Sect. III. p. 207. 


Remarks.—Prof. Rabenhorst considers S¢é. alternans and tricorne, as simple varie- 
ties of St. dilatatum, whilst both Archer and Ralfs describe them as distinct. I 
have not seen either of them, and am not therefore entitled to offer an opinion. 
Mr. Archer describes the two species as follows :— 


St. alternans, Brés. 
Segments in front view elliptic or oblong, two or three times as broad as long, separated by a 
wide sinus, twisted, unequal; rough with very minute pearly granules; e. v. with three 


obtuse and rounded angles, forming short, not colorless rays, alternating with those of the 
other segments, sides concave. L. yq37”. Br. ray¢”. 


St. tricorne, Brés. 


Segments in f. v. somewhat fusiform, often twisted, rough with minute puncta-like granules, 
tapering at each side into a short, usually colorless process, blunt or divided at the apex; 


FRESH-WATER ALG OF THE UNITED STATES. 151 


e. v. tri- or quadriradiate, processes short, usually colorless, sides somewhat concave. Spo. 
rangium orbicular, beset with spines ultimately branched at the apex. 
B. 539”. 


1. lv 
L. I2765 —97iz - 


2. Semicellule triangulares ; anguli non producti, obtust vel rotundati. 


Semicells triangular ; the angles not produced, obtuse or rounded. 


St. punctulatum, Brés. 


St. parvum, punctulato-granulosum; semivellulis enormiter ellipticis, dorso late rotundatis, a 
vertice triangularibus; angulis non productis, obtuse rotundatis ; lateribus modice retusis. 


Diam.—Lat. ,Ay5q" = .0012”. 


Syn.—S. punctulatum, Brézisson. Ratrs, British Desmidiee. RaBenHorst, Flora Europ. 
Algarum, Sect. III. p. 208. 


Hab.—Pennsylvania ; Wood. 


Small, punctulate-granulate; semicells irregularly elliptic, with the dorsum broadly rounded 
from the vertex triangular; angles not produced, obtusely rounded; sides somewhat retuse. 


Remarks.—This desmid is exceedingly common around Philadelphia, growing 
in the greatest abundance upon the face of wet dripping rocks. It is represented, 
fig. 10, pl.13. 


St. crenatum, Batter. 


St. duplo circiter longius quam latum, in medio utrinque exsectione profunda rotundata; 
semicellulis e basi cuneata flabelliformibus, margine superiore crenatis, a vertice triangularibus, 
angulis rotundato-truncatis, crenatis, lateribus sinuatis glabris. (R.) Species mihi ignota. 


Syn.—St. crenatum, Battey. Rats, British Desmidiex, p. 214. Rasenasorst, Flora Europ. 
Algarum, Sect. III. p. 220. 


“ Segments cuneate; outer margins crenate; end view with three truncate and crenate angles.” 
3. Semicellulz vertice 3-1 radiate ; radii in apice plerumque bi- tri- fidi vel bi- tri- spini. 


Semicells 3-1 radiate at the vertex; radii bi- or tri-fid, or bi- or tri-spinous at the apex. 


St. polymorphum, Brés. 

St. semicellulis ellipticis, subtiliter granulatis vel tenuissime spinulosis, in medio magis minusve 
inflatis, haud raro ventricosis, rectis, nonnunquam incurvis, utrinque processu plus minus 
elongato, lineari, in apice 3-4 fido vel spinulis 3-4 tenuissimis instructis, a vertice 3-4-5-6—-7 
radiatis, radiis achrois, aut trifidis aut rotundatis, trispinis- (R.) Species mihi tgnota. 

Syn.—St. polymorphum, Brésisson. Ratrs, British Desmidiex, p. 135. RaBennorsr, Flora 

Europ. Algarum, Sect. ITI. p. 209. 

Diam.—Long. 0.001". Lat. 0.00087”. (R.) 

Hab.—Florida; Bailey. 

Segments in f. v. broadly elliptic or almost circular, rough with minute granules (sometimes 
with a few minute scattered spines), processes short, stout, tipped by three or four divergent 
spines; e. v. with three, four, five, or six angles each produced into a short, stout process. 
Sporangium orbicular, beset with elongate spines, forked or branched at the apex. Archer. 


Var. cyrtocerum. (St. cyriocerum, Br&s.) 
Majus, ad J'”, longum, semicellulis introrsum ventricosis, dorso late rotundatis, .utrinque pro- 
cessu elongato, plerumque incurvo apice bi- vel tri-cuspidato instructis, a vertice triradiatis, 
radiis rectis vel leniter curvatis, in apice aut bi- aut tri-cuspidatis. (R.) 


152 FRESH-WATER ALG&E OF THE UNITED STATES. 


Syn.—Var. St. cystocerum, Bripisson. RABENHORST, Flora Europ. Algarum, Sect. ITI. p. 210. 
Hab.—Rhode Island; (8S. T. Olney) Thwaites. 


Segments in f. v. subcuneate, gradually widening upwards, truncate at the end margin, rough 
with minute granules, the lateral processes incurved, divided at the apex; e. v. triradiate, 
processes short, curved, sides slightly concave. L. gig”. B. gho” (Archer.) 


St. parodoxum, Meven. 
St. semicellulis inflatis, dorso rotundatis vel rectilinearibus, angulis superioribus in radium 
elongatum achroum hispidum, apice trifurcatim productis, sepius radio equali interposito 
a vertice tri- vel quadriradiatis, radiis strictis, trifurcatis, longitudine corporis diam, zquan- 
tibus vel superantibus. (R.) 


Diam.—Cum rad. .0015”. 
Syn.—St. parodozum, Muyen. Rasenuorst, Flora Europ. Algarum, Sect. III. p. 210. 
Hab.—In lacu Saco, New Hampshire; (Lewis) Wood. 


Semicells inflated, dorsum rounded or rectilinear, with superior angles produced into elongate, 
transparent, hispid radii with trifurcate apices, often furnished also with intermediate equal 
radii; from the vertex three or four radiate, radii straight, trifurcate, equalling or longer than 
the diameter of the body. 


Remarks.—I am indebted to Dr. Lewis for specimens of this species, which he 
collected at Saco Lake. 
Fig. 20, pl. 21, represents the end view of an empty frond. 


St. arachne, Ratrs. 


St. parvum, gracile, granulato-asperum; semicellulis introrsum ventricoso-globosis, angulis 
superioribus in cornu gracile, incurvum, apice obtusum, elongatis, a vertice pentagonis, 
quinque-radiatis, radiis elongatis linearibus achrois, obtusis, rectis vel leniter curvatis asperis. 
(R.) 

Diam.—Sine rad. .0005”, cum rad. .00167”. 


Syn.—St. arachne, Raurs, British Desmidiex, p. 136. Rapennorst, Flora Europ. Algarum, 
Sect. III. p. 210. 


Hab.—In lacu Saco, New Hampshire, (Lewis) Wood. 


Segments in f. v. suborbicular, rough with minute granules, lower margin turgid, outer convex, 
tapering at each side into an elongate, slender, incurved process having the granules thereon 
in transverse lines, entire at the apex; e. v. circular, bordered by five slender, linear, colorless 
marginal rays. 


Remark.—Fig. 21, pl. 21, represents an outline of the end view of the semicell. 


St. gracile, Ratrs. - 


St. mediocre, granulato asperum, granulis in series transversas ordinatis; semicellulis ventre 
valde inflatis, dorso truncatis, angulis in cornu rectum achroum gracile apice trifidum pro- 
ductis, a vertice triradiatis, lateribus sinuatis. (R.) Species mihi ignota, 


Diam.—0.0022". (R.) 


Syn.—St. gracile, Raurs, British Desmidiex, p. 136. 


RaBenyorst, Flora E . Al 
Sect. III. p. 211. urop. Algarum, 


Hab.—South Carolina; Florida; Georgia; Rhode Island ; Bailey. Rhode Island; (Olney) 
Thwaites. 


FRESH-WATER ALGA OF THE UNITED STATES. 153 


Segments in f. v. triangular, ends truncate, rough with minute granules, tapering at each side 
into elongate, straight, slender, horizontal processes, terminated by three or four minute 
spines; e. v. triradiate, processes straight, sides concave. (A.) 


C. CytTIoDERMA PILOSUM, SPINULOSUM VEL ACULEATUM. 


CYTIODERM PILOSE, SPINULOSE OR THORNY. 


St. polytrichum, Perry. 

St. mediocre, tam longum quam latum, profunde constrictum, sinu acutangulo ampliato, super- 
ficie undique setosum ; semicellulis ellipticis vel subellipticis, divergentibus, dorso subplanis, 
ventre tumidis, margine setoso-ciliatis, a vertice triangularibus, angulis obtusis, lateribus 
subrectis. (R.) 

Diam.—733," =.0017". 

Syn.—St. polytrichum, Perry. Rasenuorst, Flora Europ. Algarum, Sect. III. p. 214. 

Hab.—Prope Philadelphia ; Wood. 


Moderately large, about as long as broad, profoundly constricted, with the acute angled sinus 
widened, surface everywhere furnished with sete; semicells elliptical or subelliptical, diver- 
gent, the dorsum nearly plane, their belly swollen, the margin setose-ciliate, from the vertex 
triangular, the angles obtuse. 


Remarks.—This desmid appears to be rare in this country, as it probably is also 
in Europe. I have seen but a single specimen, which I found amongst other alge 
near Chelten Hills, north of the city. It agreed in all respects with the descrip- 
tion of Rabenhorst, as given above. 

Fig. 12, pl. 13, is a drawing of this plant, also fig. 23, pl. 21. 


St. Ravenelii, Woop. (sp. nov.) 
St. mediocre, paulo longius quam latum ; semicellulis a fronte ellipticis, a vertice triangularibus 
cum lateribus convexis vel leniter retusis et angulis rotundatis; isthmo connexivo subnullo, 
lato; sinu acutangulo; cytiodermate spinis acutis, robustis numerosis armato. 


Diam.—Long. yyy" = 0.0014". Lat. pogy” = 0.001". 
Hab.—South Carolina; (Ravenel) Wood. 
Mediocre, a little longer than broad; semicells from the front elliptical, from the vertex trian- 


gular, with the sides convex or slightly retuse, and the angles rounded ; connecting isthmus 
obsolete, broad sinus acute-angled ; cytioderm armed with numerous acute robust spines. 


Remark.—Fig. 22, pl. 21, represents the front view of an empty frond of this 
plant; fig. 22 a, the side view, and fig. 226, the end, all magnified 750 diameters. 


St. hirsutum, (Exes.) Brés. 
St. magnum, tertiam partem circiter quam longius quam latum, plus minus dense spinulosum, 
sinu plus minus lineari, acutangulo ; semicellulis late ellipticis vel subsemiorbicularibus, 
spinis tenuibus strictis hirsutis, a vertice triangularibus, angulis obtuse rotundatis, lateribus 


rectis vel leniter convexis. (R.) Species mahi ignota. 
Diam.—Sine spinis 0.0015”. Zygospor. 0.0022". (R.) 
Syn.—St. hirsutum, (EHRENBERG) BREBISSON. RaBennorst, Flora Europ. Algarum, Sect. 
IIT. p. 211. 


Hab.—Florida; Rhode Island; Bailey. Rhode Island; (S. T. Olney) Thwaites. 
20 August, 1872. 


154 FRESH-WATER ALG& OF THE UNITED STATES. 


Segments in f. v. semiorbicular, separated by a linear constriction, covered with very minute, 
very numerous close set hair-like spines; e. v. with three broadly rounded angles, the spines 
evenly and numerously scattered ; sides slightly convex. Sporangium orbicular, beset with 
short spines, branched at the apex. (A.) 


St. Mystrix, Rates. 
St. parvum, tertiam partem longius quam latum, angulis aculeatum (ceterum lave), sinu acu- 
tangulo; semicellulis subquadratis, angulis late rotundatis, dorso planis, a vertice 3-4 angu- 
laribus, angulis late rotundatis, plus minus dense aculeatis. (R.) Species mihi ignota. 


Diam.—0.001”—0 00089”. (R.) 
Syn.—St. Hystriz, Ratrs, British Desmidiee, p. 128. RaBenHorst, Flora Europ. Algarum, 
Sect. III. p. 213. 

Hab.—Rhode Island; (S. T. Olney) Thwaites. 

Segments in f. v. subquadrate, extremities somewhat rounded, end margin nearly straight, fur- 
nished with a few scattered, subulate, acute spines, chiefly confined to the lateral extremities ; 
e. v. with three or four broadly rounded angles, the spines scattered, chiefly confined to the 
extremities, sides concave. L. yy3’—rds0". Br. r1'ss"—s}2". 


St. Cerberus, (Batey) Arcuer. 

St. parvum, tam longum quam latum, sinu rotundato, superficie levi; semicellulis oblongis 
utroque fine sinuato-truncatis, angulis in aculeum cuspidatum productis, in medio sursum et 
deorsum prominentiis geminis in aculeum elongatis instructis, a vertice triangularibus, angulis 
in apice truncato- vel sinuato-bi-cuspidatis, sub apice aculeis geminis brevibus preditis. (R.) 
Species mihi ignota. 

Diam.—Cum. acul. 0.00114”’—0.0013”. (R.) 

Syn.—Didymocladon Cerberus, BAILEY, Microscopical Observations. 

St. Cereberus, (BAILEY) ARCHER. Rasenuorst, Flora Europ. Algar., Sect. IIL. p. 215. 

Hab.—Florida ; Bailey. 

Small, deeply constricted, segments three-lobed, lobes with four teeth, two of which project 
upwards and two downwards at each truncated angle. (A.) 


D. CyrloDERMA PROCESSIBUS NUMEROSIS, APICE PLERUMQUE TRUNCATIS ET DENTATO-FISSIS 
MUNITUM. : 
CYTIODERM WITH NUMEROUS PROCESSES, WHOSE APICES ARE MOSTLY TRUNCATE AND DEN- 
TATELY TORN, 


St. furcigerum, Brés. 

St. validum, submagnum, circiter tam longum quam latum, leve vel subtiliter granulatum, 
plerumque profundissime constrictum, sinu angusto lineari; semicellulis oblongo-ellipticis, 
plus minus tumidis, angulis in processus bifurcum aut rectum aut divergentem longe pro- 
ductis, dorso processibus similibus 2, 3, 4, instructis, omnibus processibus achrois granulato- 
dentatis, granulis in series transversas ordinatis, a vertice 3-, 4-, 6-, T-, 8-, 9-angularibus vel 
radiatis, angulis plus minus tumidis, in processus crassum achroum asperum in apice fissum 
productis. (R.) Species mihi ignota. 


Long. Sine process, 0.0018”—0.0019"; c. pr. 0.003’”’—0.0032". Lat. sine proc. 0.00185” ; 
ce. pr. 0.0027”. (R.) 


Syn.—Staurastrum furcigerum, Brésisson. Razennorst, Flora Europ. Algar., Sect. III. 
p. 219. 


Didymocladon furcigerus, Raurs, British Desmidier. 
Hab.—South Carolina; Florida; Rhode Island; Bailey. 


St. munitum, Woop. 


St submagnum, fere } plo longius quam .atum, medio leviter constrictum, semicellulis a fronte 


FRESH-WATER ALG OF THE UNITED STATES. 155 


enormiter hexagonis, angulis in processus rectos et divergentes productis, dorso processibus 
similibus 4-5 instructo; semicellulis a vertice polygonis vel suborbicularibus margine proces- 
sibus numerosis, plerumque 9 instructo; dorso processibus 5-8 instructis ; processibus omni- 
bus similibus, granulato-dentatis, apice achroo simplicibus, bifurcatis vel fissis. 


Diam.—A vertice cum processibus, ysXJ55” = .00475". Sine process. 559” = .002”. 
Syn.—St. munitum, Wood, Proceed. Ac. Nat. Sc., 1869. 
Hab.—In lacu Saco, New Hampshire; (Lewis) Wood. 


8. rather large, about one-half longer than broad, slightly constricted in the middle; semicells 
from the front irregularly hexagonal, the angles prolonged in straight divergent processes, 
and the surface furnished with four or five similar ones; semicells from the vertex polygonal 
or suborbicular, the margin furnished with numerous processes, mostly about nine, and also 
with 5—8 on the dorsum; processes all similar, granulate-dentate, their transparent apices 
simple, bifurcate or torn. 


Remarks.—This species is most closely allied to St. furcigerum, Bréb., from 
which it is at once distinguished by the orbicular vertex. The constriction between 
the semicells is also very different. In St. munitum it is a gradual, not very deep, 
hour-glass contraction ; in S¢. furcigerwm it is very narrow and linear. 

Fig. 13 a, pl. 13, is a front view of this plant magnified 260 diameters ; fig. 13 8, 
the end view of the same. 


St. eustephanum, (Exzs.) Ratrs. 
St. laterum integrorum angulis productis apice spinulosis, spinularum furcatarum corona media 
dorsali. (R.) Species mihi ignota. 
Syn.—Desmidium eustephanum. EurenserG, Verbreitung und Einfluss der Mikrosk. Lebens 
in Siid- und Nord-Amerika, t. 4, f. 23. 
Staurasirum eustephanum, (EuRB.) Raurs, British Desmidiex, p. 215. 
Stephanoxanthium eustephanum, Kirzinc. Rapenuorst, Flora Europ. Algarum, Sect. 
III. p. 221. 
Staurastrum eustephanum, Ratrs. RasEnuorst (loc. cit.) 
Hab.—West Point, New York; Bailey. 
End view triangular with six emarginate spines on the upper surface; each angle terminated 
by a short ray tipped with spines. (Ralfs) 


St. senarium, (Eee ) Ratrs. 
Antecedenti simile sed laterum parietibus spinulis furcatis binis (sex), corona dorsali senaria. 
(R.) Species mihi ignota. 
Syn.—Desmidium senarium, EurenserG, Verbreitung. T. IV. 
Stephanoxanthium senarium, Korzing. RABENHORST, Flora Europ. Algarum, Sect. ITI. 
p. 220. 
Staurastrum senarium, (EuRB.) Raxrs, British Desmidiee. RaABENHORST, (loc. cit.) 


Segments smooth in end view with three angles, each terminating in a short process tipped by 
minute spines, without lateral processes, but with six others confluent at their bases on the 


upper surface, divergent and forked. (Archer.) 


Genus XANTHIDIUM, Eure. 


Cellule singule vel geminz concatenate, inflato-rotundate, profunde constrict ; semicellule 
compress, oblong, hemispherice vel subquadrangulares, centro in tuberculum rotundatum vel 
truncatum et denticulatum protuberantes, ex transverso oblongo-rotundatew. Cytioderma firmum 
setis, aculeis vel spinis simplicibus aut bi- tri-furcato-divisis armatum. Massa chlorophyllacea 


radiatim expansa. Zygospore armate. (R.) 


156 FRESH-WATER ALG& OF THE UNITED STATES. 


Cells single or geminately concatenate, inflated, profoundly constricted ; semicells compressed, 
oblong, hemispherical or subquadrangular, protruding in the centre as a rounded truncate or den- 
ticulate tubercle. Cytioderm firm, armed with sete, or simple, or bi- tri-furcately divided spines. 
Chlorophyl radiately expanded. Zygospores armed. 


Remark.—It has so happened that I have identified but a single species of this 
genus. 


X. aculeatum, Exzz. 

X. parvum, singulum, sparsum, diametro ipse subequale, ex obliquo ellipsoideum, diametro 
duplo longius, constrictione obtusa lineari, semicellulis oblongis subreniformibus, basi sub- 
planis, dorso late rotundatis, tuberculo centrali minus elevato, truncato, margine autem crenato- 
dentato; cytiodermate undique aculeis subulatis obsito. (R.) Species mihi ignota. 


Diam.—(Sine aculeis) 0.0025” —0.0029". (R.) 

Syn.—Xanthidium aculeatum, EHRENBERG. Razsenuorst, Flora Europ. Algarum, Sect. ITI. 
p. 222. 

Hab.—Prope Savannah, Georgia; Bailey. 

Frond inf. v. broader than long; constriction deep, linear; segments somewhat reniform ; 


spines subulate, short, scattered, chiefly marginal; central protuberance cylindrical, truncate, 
border minutely dentate. (A.) 


X. Arctiscon, Exzs. 
X. semicellulis globosis, binis, aculeatis, aculeis numerosis undique sparsis crassis asperis apice 
trilobis. (R.) Species mihi ignota. ‘ 
Syn.—X. Arctiscon, HaREnBeRc. RasBEnHorst, Flora Europ. Algarum, Sect. III. p. 224. 
Hab.—America borealis ; Ehrenberg. 


Frond in f. v. about as long as broad; constriction forming a wide notch; segments narrowed 
at the base, with broadly rounded ends; spines numerous, restricted to the outer margin, 
scattered, elongate, stout, terminated by three or four diverging points. (Archer. ) 


X. armatum, (Brés.) Ratrs. 

X. maximum, validum, solitarium vel binatim conjunctum, diametro pleramque duplo longius; 
semicellulis subcordatis vel angulari-rotundatis tuberculo centrali subelevato, truncato, mar- 
gine granulato-dentato preditis; cytiodermate verruculoso et processibus sepius geminatis 
truncatis apice inciso-furcatis instructo. (R.) 


Syn.—Xanthidium armatum, (BRéBisson) Raxrs, British Desmidierw et Rasenworst, Flora 
Europ. Algarum, Sect. III. p. 222. 


Hab.—South Carolina; Florida; Bailey. Saco Lake; (Lewis) Wood. 


Frond large, in f. v. twice as long as broad; constriction deep, linear; segments broadest at 
the base; ends rounded or somewhat truncate; spines in pairs, principally marginal, short, 
stout, terminated by three or four divergent points; central projections cylindrical truncate, 


the border dentate; e. f. punctate. Sporangium large, orbicular, with depressed tubercles, 
perhaps immature. L. 735”. B. gh”. (A.) 


Remark.—Fig. 17, pl. 13, is a front view of a frond, magnificd 260 diameters. 


X. bisenarium, Eure. 


X. semicellulis globosis subangulosis, binis, aculeatis; aculeis fasciculatis, fasciculis in quovis 
globulo senis. Species mihi ignota. 


Syn,—X. bisenarium, EHRENBERG. RaBenuorst, Flora Europ. Algarum, Sect. III. p. 224. 
X. Brébissonii, Raurs. Ancor, PrrrcHarp’s Infusoria, p. 736. 


FRESH-WATER ALGA OF THE UNITED STATES. 157 


Hab.—America; Ehrenberg. 


Frond in front view broader than long; constriction deep, acute not linear; segments subellip- 
tic, sometimes irregular spines subulate, geminate, marginal, central protuberance cylindrical, 


truncate border minutely dentate. L. (not including spines) gig”. B. gig” to 43”. 


xX. cristatum, Bris. 


X. parvum, leve; semicellulis subhemispherico-reniformibus, utroque polo aculeo unico in- 
curvo, ambitu aculeis octo geminatis, a dorso ovato-ellipticis, utroque polo aculeis ternis, in 
medio plerumque aculeo abbreviato. (R.) Species mihi ignota. 


Diam.—0.00196". R. 


Syn.—X. cristatum, Brépisson. Ratrs, British Desmidies, et Razennorst, Flora Europ. 
Algarum, Sect. III. p. 224. 


Hab.—South Carolina; Georgia; Florida; Bailey. 


Frond rather longer than broad; constriction deep, linear; segments subreniform or truncate 
at ends; spines straight or curved, subulate, marginal, one at each side, at the base of the 
segment, solitary, the others geminate, in four pairs ; central protuberance short, conical. (A.) 


X. coronatum, Expres. 


X. semicellulis subglobosis binis, aculeatis, ubique asperis, aculeis crassis apice truncatis triden- 
tato-coronatis quatuor utrinque dorsalibus, uno utrinque latere medio. (R.) Species mihi 
ignota. 


Syn.—X. coronatum, Eurenserc, Verbreitung, p. 138, et RaBEnnorst, Flora Europ. Alga- 
rum, Sect. III. p. 224. 
Asteroxanthium coronatum, Ktrzine. Rapenuorst, (loc. cit.) 


Hab.—Awmerica; Ehrenberg. 


Remark.—Mr. Archer appears to think that this species is simply a form of 
Staurastrum furcigerum. (BReEB.); see Pritchard’s Infusoria, p. 743. 


X. fasciculatum, Exrs. 

X. parvum, singulum, constrictione profunde lineari; cytiodermate levi vel sublevi; semicel- 
lulis oblongo-reniformibus vel hexagonis, diametro duplo longioribus, ambitu aculeis gracilibus 
geminatis 4-6, a dorso ellipticis, utroque polo aculeis quatuor instructis. (R.) Species mihi 
ignota. 


Diam.—0.00228"—0.00256”. (R.) 
Syn.—X. fasciculatum, HHRENBERG. RABENHORST, Flora Europ. Algarum, Sect. III. p. 223. 
Hab.—South Carolina; Georgia; Florida; Rhode Island; Bailey. 


Frond about as long as broad; constriction deep, linear; segments somewhat reniform or sub- 
hexagonal, twice as broad as long, spines slender, subulate geminate, marginal, in four or six 
pairs; central protuberance short, conical, somewhat truncate. (A.) 


Genus ARTHRODESMUS, Eurs. 


Cellule profunde constrict ; semicellulea compresse aut oblonge, utroque polo aculeo subulato 
firmo instructe, aut quadrangulares, angulis in aculeum rectum vel curvum productis, a dorso vel 
ellipticee vel fusiformes. Massa chlorophyllacea in fascias quatuor radiantes disposita. (R.) 


Cells profoundly constricted; semicells compressed or oblong, furnished at each end with a subu- 
late spine, or else quadrangular with the angles produced into straight or curved spines, the dorsal 
aspect, elliptic or fusiform. Chlorophyl masses disposed in four radiating fascia. 


158 FRESH-WATER ALG OF THE UNITED STATES. 


Remarks.—I have found only a single undescribed species of this genus, but the 
following European forms have been detected in this country by Prof. Bailey. The 
genus appears to be, as Prof. Rabenhorst says, scarcely distinguishable from Xan- 


thidium or Staurastrum, 


A. octocornis, Exrs. 
A. parvus, levis, constrictione lata excavata; semicellulis trapezoideis, inciso-quadriradiatis, 
radiis in aculeum acutissimum strictum porrectis, a latere elongato-ellipticis, diametro fere 
triplo longioribus, utroque polo aculeum singulum gerentibus. (R.) 


Diam.—0.00065”". (R.) 
Syn.—Xanthidium octocorne, Rats. Batuey, Microscopical Observations, p. 29, 


Arthrodesmus octocornis, EHRENBERG. RABENHORST, Flora Europ. Algarum, Sect. II. 
p. 223. 


Hab.—Florida; Rhode Island; Bailey. 


Frond smooth, minute, about as long as broad; constriction a wide notch; segments much 
compressed, trapezoid, each angle terminated by one or two straight, subulate, acute spines, 
the intervals between the angles concave. (A.) 

a, Spine solitary at each angle. L. yyy”. B. ype”. (A) 

b. Larger spines geminate at each angle. L. yogq’. B. phy”. (A) 


A. quadridens, Woop. 

A. late ovalis, vel suborbicularis, paulum longior quam latus, cum margine crenato-undulato; 
semicellulis nonnihil reniformibus, utroque fine aculeo subulato, modice robusto, acuto, re- 
curvo, armatis; cytiodermate cum verruculis paucibus modice minutis in seriebus paucibus 
dispositis instructo; semicellulis a vertice acute ellipticis, et cum margine crenato et super- 
ficie sparse verruculosa. 

Diam.—Lat. zero = .00075” ; long. ee => .00125”. 

Syn.—A. quadridens, Wood, Proc. A. N.S. 1869. 

Hab.—In lacu Saco, (Lewis) Wood. 


Broadly oval or suborbicular, a little longer than broad, with the margin crenately undulate ; 
semicells somewhat reniform, at each end armed with a subulate, moderately robust, acute, 
recurved large spine ; cytioderm with a few smallish tubercles arranged in three or four rows ; 
semicells from the vertex acutely elliptical, with the margin crenate and the surface sparsely 
warty. 

Remarks.—This species approximates A. divergens, from which it differs in the 
arrangement of its granules, its attaining not one-half the size, and, I believe, in 
the larger and more robust spines. 

Fig. 2, pl. 20, represents an empty frond of this species. 


A.Incus, (Brés.) Hassat. 


A. parvus tam longus quam latus, constrictione lineari obtusa vel late excisa; semicellulis 


oblongo-quadrangularibus, angulis externis aculeatis, internis rotundatis inermibus, aculeis 
longis singulis divergentibus. (R.) ; 


Diam.—Max. 0.00098”. Long. 0.00091". Spor. (sine acul.) 0.00085”. 


Syn.—A. Incus, (Bré&sisson) Hassan, Fresh-Water Alga, p- 357, et Ragennorst, Flora 
Europ. Algarum, Sect. III. p. 226, 


Hab.—Georgia; Florida; South Carolina; Rhode Island; Bailey. 


Frond minute, smooth, as long, or longer than broad, constrictions a deep notch or sinus; seg- 


ments with inner margin turgid, outer truncate; spines subulate, acute ; Sporangium orbicular 
spinous; spines subulate. (Archer) 


FRESH-WATER ALG#A OF THE UNITED STATES. 159 


A. convergens, Exrs. 


A. levis mediocris, profunde et anguste constrictus, aculeis convergentibus armatus; semicel- 
lulis ellipticis vel ovato-oblongis, nonnunquam reniformibus, utroque fine aculeo longo firmo 
incurvo instructis. (R.) 


Diam.—0.00185"—0.0016”. (R.) 
Syn.—A. convergens, EHRENBERG. RaBENHORsT, Flora Europ., Algarum, Sect. III. p. 221. 
Hab.— South Carolina; Georgia; Florida; Rhode Island; Bailey. 


Frond smooth, broader than long; constriction deep, acute; segments elliptic, each having its 
lateral spines curved towards those of the other; ends convex. L. ,As5"— zh" B. q277"— 
sez. (Archer) 


Famiry ZYGNEMACEA. 


Cellule cylindric, zequipolares, similes, in familias filamentosas arcte conjuncte, et cytioblasto 
centrali plasmate plerumque radiante involuto, et plasmate chlorophylloso aut effuso, aut effigurato, 
aut (plerumque) in fascias spirales ordinato, et granulis amylaceis instructe. Filum simplex. Pro- 
pogatio fit zygosporis conjugatione cellularum binarum ortis. Conjugatio triplici modo, aut lateralis 
aut scalariformis vel genuflexa. Vegetatio fit divisione transversali repetita. 


Cells cylindrical, the same at both ends, closely conjoined into filamentous families, furnished with 
a central cytioblast wrapped up in generally radiating protoplasm, and with chlorophyllous proto- 
plasm effused in shapeless masses or arranged in spiral filaments, and also with scattered starch- 
granules. Filament simple. Propagation takes place by means of zygospores, arising from the 
conjugation of two cells. Conjugation occurring in three ways, lateral, scalariform, and genuflexuous. 
Growth taking place by means of transverse division of the cells. 


Remarks.—The family under consideration is among the commonest and most 
widely diffused of all the fresh-water alge. In almost every ditch or spring, or 
dripping moss-covered rock representatives of it are to be found, so that wherever 
quiet water is they may be confidently looked for. The single filaments are so minute 
that frequently the unaided eye cannot distinguish them, but multiplication with 
them is such a rapid process, that wherever found they are in great masses. These 
masses, when growth is active, are of a beautiful intense green, glistening and 
shining with the gelatinous matter which coats the threads and makes the mass so 
slippery. They may be found in greater or less abundance at all seasons, but as 
the specific characters are largely of sexual origin, non-conjugating specimens are 
of little value. For this reason, Zygnemas are only worth gathering when in fruit. 
The spores appear to be formed only in the spring and early summer, at least these 
are the only times in which I have found fertile filaments. In this neighborhood 
I have collected them in excellent condition as early as the beginning of April and 
as late as the latter part of June. Further south, conjugation of course commences 
earlier, and fine fruiting specimens received by myself from Mr. Canby were col- 
lected in Florida by him in February. — 

When conjugating freely the mass of Zygnema or Spirogyra loses its beautiful 
bright green color and become dingy and even brownish, often very dirty looking. 
The collector soon learns to pass by the beautiful vivid mass, as comparatively 
worthless, and fasten upon the pale, wan, sickly, apparently dying specimens as 
prizes worthy of a place in his cabinet. 

In the Zygnemacee the individual plant, as ordinarily considered, is a filament 


. 


160 FRESH-WATER ALG& OF THE UNITED STATES. 


composed of a varying number of cells placed, end to end, all alike, and each of 
them apparently independent of its associates. Each cell in one sense is, therefore, 
a perfect, complete individual, capable of living dissociated from its companions. 
How far the life of one of these cells is influenced by that of its neighbors is un- 
certain, probably to a slight extent, possibly not at all. At any rate, they are so 
far independent that the filament is rather a composite body than a unit of life. 
These cells are cylindrical, with the ordinary cellulose wall, which can commonly 
be stained blue by iodine and sulphuric acid, and is often distinctly composed of 
layers, but never has any “secondary markings,” each layer being precisely like 
that superimposed upon it. Outside of the wall is a jelly-like sheath, which is 
mostly not discernible from its thinness and transparency, although it no doubt 
exists, as is proven by the slipperiness of the general mass. The primordial utricle 
is always present. The chlorophyl is variously arranged, most generally in bands, 
either straight or spiral, sometimes in definite irregular masses, sometimes diffused 
through the cell. Imbedded in it are, at certain seasons, numerous minute, gene- © 
rally shining, granules, which are either minute specks of starch, or little drops of 
oil. Besides these there are contained in it, especially in the bands of chlorophy], 
more or less numerous comparatively large, oval or roundish bodies, with a distinct 
outline and a deeper color than the surrounding portions. ‘These masses are pro- 
toplasm, dyed with chlorophyl-green, and are believed to be especially active in 
the formation of starch. At times, iodine turns them simply brown; at others it 
colors their inner portions blue and their outer brown, showing them to contain 
starch. The general cavity of the cell is occupied by fluid, in which is placed the 
nucleus. ‘This is mostly single, but rarely, according to Negeli and other authori- 
ties, double, and De Bary states that he has seen three nuclei in a single cell. I 
have never seen more than one, and think that even this is not rarely absent, having 
certainly repeatedly failed to demonstrate its presence. It is colorless, often with 
a nucleolus, transparently bright, irregular in form, placed in the centre of the cell 
with numerous arms radiating out from it, some of them ending within the cell, 
others connecting it with the primordial utricle. De Bary states that this nucleus 
occasionally is tinged green with chlorophyl, I do not remember ever to have seen 
it so. 

Ihave not infrequently seen numerous minute dark granules, similar to those 
seen in Closterium, scattered through the inside of the cell, in active motion. Some- 
times they are to be found collected in vast numbers near the ends of the cells, 
dancing and swarming about one another, and passing off in small streams from 
one end to the other, coasting along close to the primordial utricle, in a word, ex- 
hibiting precisely the same motions as are so common among the desmids. 

The Zygnema filament grows in length by a process of cell multiplication by 
division of the simplest kind. It seems to be somewhat uncertain whether the 
nucleus always divides into two as a part of the process or not. These plants 
multiply both by the separation of cells and their subsequent growth, and, by 
means of resting spores, the so-called Zygospores, 

The first appearance of separation of the cells is an evident disposition to the 
rounding off of the ends of the cells. The corners are first rounded and separated 


FRESH-WATER ALG&H OF THE UNITED STATES. 161 


and this continues until only the centres of the ends are in apposition, and in a 
little while even these separate. This certainly, at least, is the process in certain 
species; but I have thought, that in other cases cells were separated by a simple 
splitting of the end wall, each cell retaining its half of the partition. 

The zygospores are produced by a process of union of two cells, to which the 
name of conjugation has been given. Very rarely, if ever, is there any difference 
between the cells before conjugation, and it has not existed in any species which has 
come under my notice; but, after conjugation, the receiving cell is frequently 
enlarged, the other remaining cylindrical. De Bary, however, states that he has 
found a small but constant difference between the fertile and sterile cells of 
Spirogyra Heeriana. 

The first perceptible change in a cell about to produce a resting spore, appears 
to be a loosening of the primordial utricle from the outer wall, and a contraction 
-of it upon the cell contents, which thus are crowded together and more or less 
deformed. Simultaneously with this, or a little after or before it, the side wall of 
the cell is ruptured and a little pullulation or process is pushed out, which directly 
coats itself with cellulose and rapidly enlarges to a considerable diameter, at the 
same time growing in length until it meets a similar process pushing out from an 
opposing cell, or has attained as great a length as its laws of development will 
allow. When two processes meet they become fused together, the end walls are 
ruptured, and the contents of one cell passing over are received within those of the 
other, or else the contents of both cells meet within the connecting tube and there 
fuse together. This is the more common mode of conjugation, in which two cells 
of distinct filaments become joined together by a connecting tube. It is evident, 
that, if the filaments are fertile to their fullest extent, there will be as many of these 
connecting tubes as there are pairs of cells in the filaments, and a ladder-like body 
will be formed, the original filaments corresponding to the side pieces, the connect- 
ing tubes to the rounds. Hence this method of conjugation has received the name 
of scalariform. 

In the so-called “Jateral conjugation,” instead of cells of different filaments join- 
ing, adjacent cells of one filament unite together to complete the process. The 
union of the two cells appears to take place in several ways. In accordance with 
one plan (fig. 1 a, pl. 14), connecting tubes, pushed out from near the ends of 
the cells, grow for a short distance nearly at right angles to the long axis of the 
filaments, and then bend at aright angle to themselves so as to run parallel to 
the filament-cells. The ends of these processes are, of course, opposed to one 
another, and coming in contact fuse together so as to form a continuous tube for 
the passage of the endochrome. Another method by which neighboring cells are 
sometimes connected is by the formation of coadjacent pouch-like enlargements of 
the opposing ends, and a subsequent fusion of these newly formed enlargements 
by the absorption of the end wall between them. (See fig. 2, pl. 14.) 

Sometimes I think the union of two neighboring cells is facilitated by a curved 
neck forming to one or both of them, so that they are bent at an angle to one 
another, andican readily be united by means of a straight tube. 


There is still another method of conjugation, the so-called gen uflexruous, in which, 
a1 August, 1872, 


162 FRESH-WATER ALG#Z OF THE UNITED STATES. 


instead of a connecting tube being formed as the medium of union, two cells of 
opposing filaments become sharply bent backwards, so that their central portions 
are strongly thrust forward as obtuse points, which, coming in contact, adhere and 
allow of a passage-way between the cells being made by the absorption of their 
cohering walis, 

A curious modification of, or departure from, the ordinary method of conjugation 
is sometimes seen, in the union of three instead of two cells. This is, I think,. 
very rare, but has been seen by Meyen in the genus Zyynema, as well as by 
Schleiden and De Bary in Spirogyra. I myself have observed it once or twice in 
the latter genus. One of the cells plays the part of the female, receiving the con- 
tents of the other two, so that in it the primordial utricles of the three, with their 
contracted protoplasm, are fused into a zygospore. 

The zygospore, however formed, varies in shape, but is mostly oval or globular, 
sometimes cylindrical, and when ripe is in most if not all species of a dark brown- 
ish color. It is described both by Pringsheim and De Bary as having three coats, 
but I have frequently found it impossible to demonstrate the presence of all of 
these, and I believe that not rarely one of them is absent. The outer coat is 
developed first and is the thickest and firmest. Occasionally it is double, i. ¢. 
composed of two distinct layers or parts, as in Sp. protecta, in which species the 
outer of these layers is the thickest, firmest, and most evident, whilst the inner 
layer is translucent and much less apparent. ‘The second coat contains the 
coloring matter, which is sometimes brown, sometimes decidedly yellowish. ‘The 
inner coat is not readily seen. It is elastic, thin, and is the last of the three to be 
formed. 

The principal contents of the ripe spore are protein compounds (protoplasm), 
oil-drops, starch granules, and pigment. The oil is generally much more abun- 
dant than the starch, and not rarely the minute, bright drops entirely replace 
the little granules. According to Prof. De Bary, the pigment frequently, but not 
always, reacts with sulphuric acid, as does that of the fungal family, Uredinee, 
striking with it a deep blue. 

The germination of the spore, both in the genus Spirogyra and Zygnema, is 
very simple. The first step is an elongation and growth of the protoplasmic 
central mass, together with the inner transparent cellulose coat, and a consequent 
rupturing of the outer two coats, through which the newly forming plant protrudes 
and finally escapes. In this way in the genus Spirogyra an elongated club-shaped 
cell arises, one end of which is much larger than the other and contains all the 
chlorophyl. Sometimes a nucleus is perceptible in this cell, sometimes it is not. 
The larger end now becomes cut off by a partition wall from the smaller; if no 
nucleus has been previously apparent it now becomes so, and the first stage of 
development is completed. The filament after this grows by a simple repetition 
of the process of division in the larger end and the cells formed out of it. The 
smaller end undergoes little or no change. In the genus Zygnema, the cell that 
first emerges from the germinating spore is a perfect one, similar in all respects to 
those seen in the fully formed filament, which is developed out of it, by a simple 
process of cell division. 


FRESH-WATER ALG OF THE UNITED STATES. 163 


Besides the true Zygospores, Hassall many years since described bodies (Fresh- 
water Alge, vol. i. pp. 182, 156, 170), which he found in filaments of this family, 
and which resemble in all respects ordinary Zygospores, but are produced each 
in a single cell without any aid from-a second cell. He affirmed that he had 
observed this phenomenon especially in two species, Spirogyra mirabilis and 
Zygnema notabilis, These observations were doubted by some, whilst others, as 
Alexander Braun, supposed that there was a division of the cell protoplasm into 
two distinct portions, and then a conjugation of these within the original cell, and 
that Mr. Hassall had overlooked these changes. Prof. De Bary, however, states 
that he has seen a great many instances of this production of spores without conju- 
gation (all in one species), and that there can be no doubt that Hassall’s obser- 
vations are substantially correct, and that no division of the primordial utricle such 
as was imagined by Prof. Braun takes place. Spores formed in this manner, as 
yet have nat been seen to develop. There is, therefore, no certainty that they are 
capable of doing so. It is possible that they are merely the results of abortive 
attempts at reproduction, wanting the power of development because not fertilized. 

Pringsheim and others have drawn from these bodies strong argument against 
the idea, that conjugation is to be looked upon at all as a sexual process, 

The arguments both for and against regarding conjugation as the simplest ex- 
pression of sexual life are ably elaborated by De Bary, Untersuchungen iiber die 
Familie der Conjugatem, p. 57, to which I must refer those desirous of following 
the subject further, contenting myself with expressing an agreement with the con- 
clusions there arrived at, namely, that in conjugation the first dawnings of sexuality 
are to be found. Looking at it in this light Prof. De Bary states his conviction 
that the spores formed in the manner last described, bear the same relation to the 
true Zygospore that the bud of a Phanerogam does to its seed, or the Zoospore of 
an Cidogonium does to its resting spore. 

Quite a number of bodies have been described by the older authorities as being 
found within the cells of plants of this family, which more recent observers have 
proven to be parasitic. Such are the “Spermatic spheres,” transparent spheres 
motile by virtue of vibratile cilia, various monads, &c. &c., bodies for which it has 
been claimed, from time to time, that they were sexual elements, spermatozoids. 


Genus SPIROGYRA, Linx. 


Cellule vegetative cylindric, fasciis chlorophyllosis spiralibus instructe. Conjugatio aut. later- 
alis aut scalariformis aut et lateralis et scalariformis. 


Syn.—Spirogyra et Rhynchonema, Kurzinc, RaBENuoRST, et auctores. 
Salmacis, Bory. 
Zygnema (partim), Hassa.. 


Vegetative cells cylindrical, furnished with spiral chlorophyl bands. Conjugation either lateral 
or sealariform or both lateral and scalariform. 


Remarks.—The genus Spirogyra, as defined above, has been divided by Kitzing, 
Rabenhorst, and others into two genera, the characters being drawn from the 
method of union of the conjugating cells; in the one case the neighboring cells of 
a single filament (Rhynchonema), in the other cells of distinct filaments (Spirogyra), 


164 FRESH-WATER ALG#& OF THE UNITED STATES. 


uniting to form the spore. This at first sight appears to be a good ground for sepa- 
ration, but there are certain species in which, undoubtedly, both the former and 
the latter method of conjugation take place indifferently. Such species make a 
third group so precisely between the two others as, to my mind, to fuse them toge- 
ther and necessitate either the acknowledgment of three genera or the denial of 
more than one. The latter seems to me the more philosophical course. 


A, CONJUGATIO LATERALIS (RHYNCHONEMA). 
A. CONJUGATION LATERAL. 
Sp. elongata, Woop. 

Sp. articulis vegetativis diametro 7-20 plo longioribus; articulis sporiferis multo brevioribus, 
valde tumidis ; cytiodermate utroque fine protenso et replicato ; fascia unica, laxissime spirali; 
anfractibus plerumque 7; sporis ellipticis, diametro 1-24 plo longioribus. 

Diam.—Spor. 757” = .00106". Artic. vegetat. 745” =.0005”. 

Syn.—Rhynchonemaelongatum,W oop, Prodromus, Proc. Amer. Philos. Soc. 1869, p. 187. 

Hab.—In aquis limpidis, prope Philadelphia. 

Sterile joints 7-20 times longer than broad; fertile joints much shorter, greatly swollen; cell 


wall at each end produced or folded in; chlorophyl filament 1, spiral lax; turns mostly 7; 
spores elliptical, 2-24 times longer than broad. 


Remarks.—I found this species about the middle of March, fruiting in a little 
pool near Chelten Hills, six or eight miles north of this city. It did not form a 
distinct stratum by itself, but was floating, intermingled with great numbers of 
other filamentous alge, such as fragillarie, zygneme, &c. It seems to be most 
closely allied to the European R. minimum ; it however not only attains a some- 
what larger size but also differs from that plant in the proportionate length of the 
sterile cells, in the number of the turns of the chlorophyl spiral in the cell, and in 
the proportionate length and breadth of the spore. 

Fig. 1, pl. 14, represents portions of sterile filaments magnified 450 diameters ; 
la, a part of a fertile filament, magnified 450 diameters. 


Sp. pulchella, Woop. 


Sp. articulis sterilibus diametro 2-3 plo longioribus; sporiferis nonnihil tumidis; fascia unica, 
anfractibus 3-4; sporis ellipticis, diametro fere duplo longioribus; cytiodermate utroque fine 
protenso et replicato. ; 


Diam.—Artic. Steril. 7f55"—725q" =.00033"—.0013” Spor. Te00 —7h 89" =.0012"”—.00133”". 
Syn.—Rhynconema pulchellum, Woon, Prodromus, Proc. Amer. Philos. Soc. 1869, p. 138. 
Hab.—In stagnis, prope Philadelphia. 


Sterile joints 2-3 times longer than broad; fertile joints somewhat swollen; chlorophyl band 


one; turns of spiral 3-4; spores elliptical, almost twice as long as broad; cell wall at each 
end produced or folded in. 


Feemarks.—This species was found by myself fruiting in April, 1869, in stagnant 
ditches below the city, and in similar localities near Camden, New Jersey. It did 
not occur in masses but singly, intermixed with great numbers of other fruiting 
spirogyras. Most of the filaments seen were about 0010” in diameter; in but a 
single instance did they come much short of this. This species differs from R. 
elongatum, among other points, in the shortness of the tubes connecting the fertile 


FRESH-WATER ALG OF THE UNITED STATES. 165 


cells. I have never been able to identify an entirely sterile filament of this species; 
the measurements and description of the sterile cells were taken from infertile cells 
in filaments, which in other places had produced spores. 


Fig. 2, pl. 14, represents a fertile filament, magnified 260 diameters. 


w 


. CONJUGATIO SCALARIFORMIS (SPIROGYRA VERA). 
Cytiodermate utroque fine protensum et replicatum. 
. Cytioderm folded in at the ends. 

Fascia spiralis unica. 

Spiral filament single. 
Sp. Weberi, K1z.? 


Sp. saturate viridis, lubrica; articulis vegetativis diametro 3-20 plo longioribus; fructiferis 
nonnihil inflatis; fascia dentata, plerumque unica sed fasciis duabus in quavis cellula; spire 


anfractibus 3-8; cytiodermate plerumque utroque fine protenso et replicato ; zygosporis ellip- 
ticis. : 


gS 8 


* * 


Diam.—Artic. steril. 7% 5"—7 255" = .0008"—.0012”. 

Syn.—S. Weberi, Kirzine. RaBennorst, Flora Europ. Algarum, Sect. III. p. 233. 
Hab.—In stagnis, prope Philadelphia. 

Deep green, slippery; sterile joints 3-20 times longer than broad; fertile joints not swollen; 


chlorophyl filaments mostly single, but sometimes two in certain cells, dentate; turns of the 
spiral 3-8; cytioderm protruded or infolded at the ends; zygospores elliptical. 


Remarks.—This species, which is abundant around Philadelphia in stagnant 
ditches, I have found fruiting in the month of April. The number of spirals fre- 
quently varies even in the same filament. The infolding of the walls at the end 
of the cells is very often wanting in the fertile cells and occasionally is absent from 
one end of an ordinary vegetative cell. The American form agrees pretty well 
with the European, but is, however, larger, and also attains in its cells a greater 
proportionate length and has more turns of its chlorophyl spirals. The lower 
limits of the American form are, however, so overlapped by the upper limits of the 
European, that it seems to me they must be considered identical. 

Fig. 19, pl. 12, represents a pair of fertile filaments of this species, magnified 
260 diameters; 19 a, part of a sterile filament, magnified 260 diameters; 19 }, out- 
line of a couple of fertile cells, magnified 260 diameters. 


Sp. protecta, Woop. 

Sp. saturate viridis, lubrica; articulis sterilibus diametro 6 plo longioribus; sporiferis vix tumidis ; 
cytiodermate utroque fine protenso et replicato ; fascia unica; anfractibus 6; sporis oblongis 
vel ellipticis : membrano crassissimo. 

Diam.—Art. steril. 7i}q” =.00146"; spor. lat. 73 95"—7} 90" = -00133"”—.0016” long. 7235" 

= 0038”. 

Syn.—Sp. protecta, Woop, Prodromus, Proc. Am. Philos. Soc. 1869, p. 131. 

Sp. deep green, slippery ; sterile joints 6 times longer than broad ; fertile cells scarcely swollen ; 
cell wall folded in at the ends; chloropby] band single ; turns 6 ; spores oblong er elliptical, 
spore wall very thick. 


Remarks.—I found this species in the latter part of April fruiting in a ditch 


in a meadow a little south of the mouth of Wissahicon Creek, near this city, 
and as late as the 25th of May in the “neck” below the city. It is remarkable 


166 FRESH-WATER ALG OF THE UNITED STATES. 


for the very great thickness of the walls of the spore. There are two very appa- 
rent coats separated by a thin not very evident one. The outer is the thickest ; 
it is very thick, firm, and nearly colorless. ‘The inner coat is of a decided orange- 
brown. The parent-cells which give origin to these spores are slightly enlarged 
in diameter. Sometimes the spores, instead of being elliptical, are irregular in 
shape. 

Fig. 3a, pl. 14, represents a sterile filament, magnified 250 diameters; fig. 3, a 
mature spore, magnified 450 diameters. 


Sp. insignis, (Hassait) Krz. 
Sp. articulis sterilibus diametro 5-14 plo longioribus; fasciis 2 (rarius 1-3), Jaxe spiralibus, 
angustis, crenatis ; articulis fructiferis nonnihil tumidis; cytiodermate utroque fine replicato 
vel protenso ; zygosporis rubido-brunneis, ovato-ellipticis. 


Diam.—0.0015”. 


Syn.—Zygnema insigne, HassauL, Fresh-Water Alge, p. 440. 
Spirogyra insignis, (HassaLL) Kirzina. Rasennorst, Flora Europ. Algarum, Sect. 
III. p. 235. 


Hab.—In stagnis, prope Philadelphia. 
Sterile joints 5-14 times longer than broad; chlorophy]l filaments mostly 2 (rarely 1-3), laxly 


spiral, narrow, crenate; fertile joints somewhat enlarged; cytioderm at each end folded in 
or produced ; zygospores reddish-brown, ovate elliptical. 


Remark.—Fig. 6, pl. 16, represents this species. 


6. Cytioderma cellule fine nec protensum nec replicatum. 
Cytioderm not infolded in the end of the cell. 

* Fasciz spirali unice (raro due). 
Chlorophyl band single (rarely two). 


Sp. longata, (V4vcsz.) Krz. 
Sp. dense cxspitosa, lete luteolo-viridis, valde lubrica; articulis sterilibus diametro 2-6 plo 
longioribus, fertilibus sepe tumidis abbreviatis ; fascia spirali lata, dentata; anfractibus sub- 
laxis 2-5 ; zygosporis ellipticis. 


Diam.—0.001". 
Syn.— Conjugata longata, VaucueEr, Histoire des Conferves d’Eau douce, p. 71. 

Sp. longata, (Vaucu.) Kiirzinc. RaBennorst, Flora Europ. Algarum, Sect. III. p. 238. 
Hab.—In stagnis, prope Philadelphia; Wood. Rhode Island; (S. T. Olney) Thwaites. 


Densely cxspitose, bright yellowish-green, very slippery ; sterile joints 2-6 times longer than 
broad ; fertile articles swollen, often abbreviate; chlorophyl filaments broad, dentate; turns 
of the spiral somewhat loose, 2-5 ; zygospores elliptical. , 


Remarks.—According to Prof. Rabenhorst, this species attains in Europe a 
diameter of .0011” and the cells a length of 8 times their breadth. The same 
authority also describes the fertile cell as being either not swollen, or moderately 
so (“aut non aut modice tumidis”), In all the specimens of our American forms 
which I have seen, the sporangial cells are very decidedly swollen. 

Fig. 4, pl. 14, represents portions of sterile filaments, magnified 250 diameters, 


and fig. 4 a, a part of a fertile pair of filaments containing immature spores enlarged 
260 diameters. 


FRESH-WATER ALGA OF THE UNITED STATES. 167 


Sp. quinina, (Ac.) Kurz. 


Sp. saturate viridis, valde lubricata; articulis sterilipus diametro 1-6 plo longioribus; articulis 
fertilibus vel haud tumidis vel nonnihil tumidis; fascia unica; spire anfractibus modo den- 
sioribus, modo laxioribus, nonnunquam laxissimis, plerumque 3, interdum 14-4; cytiodermate 

" cellule utroque fine neé protenso nec replicato; zygosporis aut globosis aut ovalibus aut 
cylindricis. . 
Diam.—Artic. steril. 7485’ —7i 35" = .0013"—.0017"; sporis ziig” =.0014”. 
Syn.—Sp. quinina, (AcarpH)Kirzine. Rasenuorst, Flora Europ. Algarum, Sect. III. p. 
240. 

Hab.—lIn stagnis, prope Philadelphia. 

Deep green, very slippery, sterile articles 1-6 times longer than broad; fertile joints scarcely 
or not at all tumid; chlorophyl filament single; turns of the spiral sometimes denser, some- 


times laxer, sometimes very lax, mostly 3 in number, sometimes 14-4; cytioderm neither 
infolded nor protruded at the end ; zygospores polymorphous, globose, elliptical or cylindrical. 


Remarks.—This species is very abundant in the ditches around Philadelphia, 
especially in the “‘neck” below the city. I have found it fruiting profusely in the 
month of April. ‘The spores vary very much in form, some of them being globose, 
others elliptic, and still others cylindrical, with obtusely rounded ends. All these 
forms may occur in a single filament. The spore cell also varies in the amount of 
its enlargement. In many cases it preserves its cylindrical shape completely; in 
ther instances it is markedly swollen. 

Figs. 4e, 4c, pl. 19, represent portions of sterile filaments of this species; figs. 
sa, 4b, and 4d, portions of fertile filaments. 


-{{ Fascizx spirale due vel plures. 
t{ Chlorophyl filaments two or many. 


Sp. decimina, (Muttzr) Ktz. 

Sp. sordide viridis, lubrica; articulis sterilibus diametro (0.00135”—0.00159”) plerumque 
duplo-, quadruplo fere longioribus, nonnunquam subequalibus, fertilibus aut non aut modice 
tumidis; fasciis spiralibus plerumque 2, latis, decussatis, rarius 1 vel 3, anfractibus laxis 
1-11; zygosporis aut ovalibus aut late ellipticis vel subglobosis. (R.) 


Syn.—Sp. decimina, (Miter) Kurzine. Rapenuorst, Flora Europ, Algarum, Sect. III. p. 
242, 
Hab.—Prope Philadelphia. | 


Dirty green, slippery; sterile joints mostly from 2-4 times as long as broad (0.00135’”— 
0.00159”), sometimes about as long as broad; fertile joints either moderately or not at all 
swollen; spiral filaments mostly 2, broad, decussating, rarely 1-3, turns loose 1-14; zygo- 
spores either oval, broadly elliptic, or subglobose. 


Remarks.—I find this species marked in one of my note-books as having been 
found by myself near this city. I have no distinct recollection of seeing it, and, 
having preserved neither figure, specimen, nor description, am forced to content 
myself with copying the description of Prof. Rabenhorst. 


Sp. dubia, Kz. 
Sp. viridis in fructe dilute viridis; articulis sterilibus cylindricis diametro 14-23 plo longioribus ; 
fasciis spiralibus 2-3, angustissimis, nodosis, anfractibus Jaxis 1-2 (= 3-6); cytiodermate 
utroque fine nec protenso nec replicato, nonnihil crasso ; zygosporis polymorphis, aut sub- 


168 FRESH-WATER ALG# OF THE UNITED STATES. 


globosis aut ovalibus, aut subcylindricis, diametro equalibus aut ? plo longioribus ; articulis 
fertilibus cylindricis, haud tumidis. 
Diam.—Art. steril. 7385” =.002; spor. 7185 — .002”. 
Syn.—Sp. dubia, Kurzina. Rapenuorst, Flora Europ. Algaram, Sect. IIT. p. 243. 
Hab.—In stagnis, prope Philadelphia. 


Green, in fruit light green; sterile joints cylindrical, 14-24 times longer than broad; spiral 
filaments 2-8, very narrow, nodose, lax, turns 1-2; cytioderm neither infolded nor protruded 
at the end, rather thick ; zygospores polymorphous, either subglobose, oval, or subcylindrical, 
as broad as long to 3 times longer ; fertile articles cylindrical, not enlarged. 


Remarks.—I have found this species growing in the ditches below the city, fruit- 
ing abundantly in May. When in this condition it forms masses of a dirty, lightish, 
yellowish-green. The spores mostly fill pretty well the fertile cells. My specimens 
do not agree completely with the descriptions given of the European. The two 
forms, however, completely overlap one another, except in one character, namely, 
the shape of the sporangial cell. I have never seen it swollen or at all tumid in 
American specimens, whilst in the European it is said to be “modice tumidis.” 
This difference alone does not, however, seem to me sufficient to characterize a 
new species. I have seen specimens of this plant collected by Dr. Lewis at Cobble 
Mountain. They agree well with the Philadelphia specimens, except in attaining 
a little larger size, .0021”, and in the sterile filaments having their walls very thick. 
The character of non-inflation of sporangial cells is perfectly preserved. 

Fig. 4, pl. 17, represents this species. 


Sp. rivularis, (Hassatt) Rasenn. (non Krz.) 

Sp. saturate viridis, lubrica; articulis sterilibus diametro 7-11 plo longioribus; fertilibus cylin- 
dricis aut vix tumidis; cytiodermato tenuissimo, utroque fine nec protenso nee replicato, 
fasciis 4, laxe spiralibus, modice angustis, nodulosis et serratis, anfractibus 24; zygosporis 
ellipticis, diametro 2-24 longioribus. 

Diam.—Art. ster. r2yq"—7h hy” = .0012"—.00146"; spor. 7395"—712,”. 

Syn.—Zygnema rivularis, HassaLu, Fresh-Water Alge, vol. i. p. 144. 
Spirogyra rivularis, (HASSALL) (non Ktrzine) Rasennorst, Flora Europ. Algarum, 
Sect. III. p. 243. 


Hab.—In rivulis, Florida; (Cansy) Woop. 


Deep green, slippery ; sterile articles 7-11 times longer than broad, fertile cylindrical or slightly 
tumid ; cytioderm very thin, neither infolded nor protruded at the end ; chlorophyl filaments 


4, laxly spiral, moderately narrow, nodose and serrulate, turns 243 zygospores elliptical, 
2-24 times longer than broad. 


Remarks.—This species was collected by Mr. Wm. Canby in Pine Barren Run, 
near Hibernia, Florida, It is rather smaller than the European forms, but does 
not appear to be distinct from them. Rabenhorst, indeed, states that there are 
only two or three chlorophyl spiral bands in a cell, but Hassall in the description 
of the type states distinctly that in some instances there are four bands, and also 
figures the plant so. 


Fig. 5 a and 6, pl. 17, represents sterile cells of this species, magnified 260 


FRESH-WATER ALGA OF THE UNITED STATES. 169 


diameters. Fig. 5 ¢ is an outline of a pair of fertile cells enlarged to the same 
extent. 


Sp. parvispora, Woop. 
Sp. articulis sterilibus diametro 2-4 plo longioribus ; fructiferis haud tumidis, diametro 1-23 plo 
longioribus; fasciis spiralibus 4, angustis, nodosis, anfractibus pluribus ; zygosporis parvis- 
simis, ellipticis, diametro 13-2 plo longioribus; cytiodermate utroque fine nec protenso nec 


replicato. 
Diam.—Art. steril 7335"=.008" ; spor. diam. transv. 7}35"—7}25" = .002”—.0023”, long. 7245” 
30" 
—T500 - 


Syn.—S. parvispora, Woop, Prodromus, Proc. Am. Philos. Soe. 1869, p. 139. 
Hab.—In stagnis, Hibernia, Florida. (WM. Cansy.) 


Sterile joints 2-4 times longer than broad; fertile not tumid, 1-24 times longer than broad ; 
chlorophyl bands 4, narrow, nodose; turns many; zygospores very small, elliptical, 14-2 
times longer than broad; cell wall not infolded at the end. 


+ Remarks.—I am indebted to Mr. Wm. Canby for specimens of this species, 
which he collected in a pond in the Pine Barrens near Hibernia, St. John’s River, 
Florida. It is remarkable for the comparatively small size of the spores, which do 
not nearly fill the perfectly cylindrical mother-cells ; indeed they are only about as 
long as the latter are wide. This species closely resembles S. majuscula, but is 
larger, does not, that I have ever seen, vary like it in the number of spores, and is 
especially separated from it by the very small size of the latter. 

Fig. 7, pl. 15, represents a fertile pair of filaments of this species magnified 125 


diameters. 


Sp. majuscula, Kz. 
Sp. pallide et sordide viridis, fructus tempore fuscescens ; articulis sterilibus diametro (0.0022” 
—0.0025”) 244-10 plo longioribus; cytiodermate tenui homogeneo; fasciis 3-4-5 (rarius 
7), modo subrectis longitudinalibus, modo laxissime spiralibus,.nodosis; zygosporis globosis 
vel ovalibus. (R.) 


Syn.—S! majuscula, Kirzine. Rapennorst, Flora Europ. Algarum, Sect. ITI. p. 244. 


Hab.—Prope Philadelphia. ? 


Pale and sordid green, fuscescent at the time of fruiting; sterile joints 23-4-10 times longer 
than broad (.0022”—0 0025”); cytioderm thin, homogeneous ; spiral filaments 3-45 (rarely 7) 
partly straightish and longitudinal, partly laxly spiral, nodose; zygospores globose or oval. 


Remarks.—Shortly after I commenced to study the fresh-water alge, I found 
below the city a fruiting Spirogyra, of which I preserved only a drawing, which I 
have since identified as apparently specifically one with the European S. majuscula, 
it differing only in not being quite so large; my measurement was z}5” = 0.002". 
Not having any specimens at hand, I have copied the description from the work of 


Prof. Rabenhorst. 
Fig. 1, pl. 15, was copied from the drawing alluded to. 


Sp. nitida, (Dittw.) Linx. : 
Sp. cespitibus, lubricis, saturate viridibus ; articulis sterilibus post vision su 
equalibus, ante divisionem 2-3 plo longioribus ; articulis fertilis aliis simillibus, haud tumidis ; 


fasciis spiralibus 4 (3-4 R.), modice latis, anfractibus 1-2; zygosporis ellipticis. 
22 August, 1872. 


4 
divisionem diametro sub- 


170 FRESH-WATER ALGH OF THE UNITED STATES. 


Diam.—0.0025”. 
Syn.—S. nitida, (Dinuwyn) Linx. Rapenuorst, Flora Europ. Algarum, Sect. IIT. p. 245. 


Hab.—Prope Philadelphia. 

Occurring in lubricous turfy masses, of a deep green color; sterile joints after division about 
as long as broad, before division 2-8 times longer ; fertile joints similar to the others, not 
tumid; spiral filaments 4, moderately broad, turns 1-2; zygospores elliptic. 

Remarks.—This species appears to be somewhat rare, at least I have found it 
but once, and then only in small quantity. Rabenhorst states that there are occa- 
sionally only three spirals, and his maximum diameter is 0.0031”; he also speaks 
of the fertile joints as “vix tumidis.” 


Sp. diluta, Woop. 

Sp. articulis sterilibus diametro subequalibus ad duplo longioribus, fructiferis hand tumidis ; 
fasciis spiralibus 5, angustissimis, laxis, valde nodosis; anfractibus plerumque 4, interdum 
1; zygosporis sparsis, late ellipticis vel ovatis aut globosis; cytiodermate modice tenue, in 
utroque fine nec protenso nec replicato. 

Diam.—Artic. steril. 7235” = .003”. 

Syn.—S. diluta, Woop, Prodromus, Proc. Am. Philos. Soc. 1869, p. 139.’ 

Hab.—In stagnis, prope Philadelphia. 


Sterile joints about as long as broad to twice longer, fertile cells not swollen ; chlorophyl bands 
5, exceedingly narrow, lax, strongly nodose; turns mostly 4, sometimes 1; zygospores few, 
broadly elliptical, ovate or globose; cell wall moderately thin, not infolded at the ends. 


Remarks.—I have found this species several successive seasons growing in the 
ditches in the Neck, below the city, especially in the neighborhood of the large 
stone barn, built by the great millionaire, and still known as “ Girard’s Barn.” 
The spirals are very narrow and slender, and are moderately close to one another. 
They are chiefly made up of a number of chlorophyl nodules, the connecting thread 
between which is often very faint. In all the fruiting specimens, as I have seen 
them, the spores have been very few in number, most of the cells of the fertile 
filaments appearing to have aborted, so that they are simply empty. In most cases 
only about every third or fourth cell contained a spore. 

Fig. 2, vl. 15, represents this species. 


Sp. setiformis, (Rorn) Krz. 

Sp. saturate viridis, lubrica; articulis sterilibus diametro paullum brevioribus ad 14 plo lon- 
gioribus; articulis fructiferis haud inflatis; fasciis 8-8, latis, dentatis; interdum nonnihbil 
remotis, sed spe arcte et dense conjunctis, nodosis; zygosporis globosis vel late ovalibus. 

Diam.—.0035”. 

Syn.—S. setiformis, (Ror) Kurzine. Rasenuorst, Flora Europ. Algarum, Sect. III. p. 246. 

Hab.—In stagnis, prope Philadelphia. 

Deep green, slippery ; sterile joints a little shorter to one and a-half times longer than broad; 
fertile joints not inflated ; spiral filaments:3-8, broad, dentate, sometimes somewhat remote, 
sometimes closely and densely conjoined, nodose ; zygospores globose or broadly oval. 


Remarks.—None of the descriptions which I have seen of this species state the 
number of the spiral filaments, but the other characters of the American form so 
agree with those of the European plant that it is probable that this one does also. 
The plant is not uncommon in the Neck, fruiting in the spring. 


FRESH-WATER ALGA OF THE UNITED STATES. 171 


Fig. 3.a, pl. 15, represents part of a sterile filament of this species; 3 6, portion 
of a pair of fertile filaments, both magnified 125 diameters. 


Sp. crassa, Krz. 


Sp. lete viridis, denique sordide viridis; articulis sterilibus diametro subsequalibus, post divi- 
sionem interdum fere 4 plo brevioribus, ante divisionem sepe fere 2 plo longioribus ; cytio- 
dermate tenui, homogeneo, utroque fine nee protenso nec replicato; fasciis spiralibus 4, 
dentatis vel tuberculatis, spe arctis, subtransversis, tenuibus; anfractibus 14-4; cellulis 
fructiferis aliis simillimis, haud inflatis ; zygosporis globosis vel ellipticis. 


Diam.—Max. .0065.” 
Syn.—Sp. crassa, Kz. Rapenuorst, Flora Europ. Algarum, Sect. III. p. 246. 
Hab.—In stagnis, prope Philadelphia. 


Bright green, but finally a dirty green; sterile articles about as long as broad, sometimes after 
division only half as long, sometimes before division twice as long; cytioderm thin, homo- 
geneous, not infolded or produced at the ends; spiral filaments 4, dentate or tuberculate, 
often close, subtransverse, thin; turns from 14 to 4; fertile cells very like the others, not 
inflated ; zygospores globose or elliptical. 


Remarks.—This species is very common in the neighborhood of this city, occur- 
ring in springs, &c., but especially in the ditches in the Neck. It forms long, 
lubricous masses, of a bright green color, readily distinguishable by the size of the 
filaments, which are separated with ease by the unaided eye. I have gathered it 
repeatedly, in fruit, from the middle of April to the middle of June. In this state 
the mass has lost its bright green color, and when the filaments are closely examined, 
even without a glass, mmute dark points mark the positions of the spores. 

Fig. 4 a, pl. 15, represents part of a filament commencing reproduction ; 4 8, fila- 
ments which have matured the spores; 4c, a pair of conjugating filaments. 


Genus ZYGNEMA. 


Cellule vegetative cylindrice. Massa chlorophyllacea initio effusa et subhomogenea, postea dis- 
tincte granulosa aut per cellule lumen distributa, granula amylacea duo centralia involvens, aut in 
corporibus duobus (in quaque cellula) plus minusve distincte stellatim radiantibus juxta nucleum 
centralum granum amylaceum unicum involventibus collocata. Conjugatio scalariformis vel late- 
ralis. 

Vegetative cells cylindrical. Chlorophyl masses in the beginning effused and subhomogeneous, 
afterwards distinctly granular, either distributed throughout the cavity of the cell, involving two 
central starch granules, or gathered together into two masses (in each cell), with more or less dis- 
tinctly stellate radii and a central starch granule placed near the nucleus, one on each side of it. 


Z. insigne, (Hassarx) Krz. 

Z. cespitibus et plerumque natantibus vel in aqua diffusis, saturate viridibus vel spe sordide 
flavo-viridibus ; articulis sterilibus diametro circiter equalibus vel duplo longioribus ; conju- 
gatione scalariforme (et sepe simul laterali, R.); zygosporis globosis; sporodermate levi. 

Diam.—Cell. ries” = .00 126” ; spor. redso —reoso” = 0.00093”—0.0001 6”. 

Syn.— Tyndaridea insignis, Hassan, Fresh-Water Alge, vol. i. p. 163. 

Zygnema insigne, (Hassaui) Kirzinc. Rasenuorst, Flora Europ. Alge, Sect. III. 
p. 249. 
Hab.—In stagnis, prope Philadelphia ; Wood. Rhode Island; (S. T. Olney) Thwaites. 


172 FRESH-WATER ALG# OF THE UNITED STATES. 


Cespitose and mostly floating or diffused in the water, deep green, or a dirty yellowish-green ; 
sterile joints about as long as broad, or twice as long; conjugation scalariform (according 
to Rabenhorst sometimes at the same time lateral) ; zygospores globose; spore coat smooth. 


Remarks.—This species is very common around Philadelphia, forming great 
masses in the ditches of the “Neck,” growing in the semistagnant water along the 
railroads, and forming with other alge slimy coatings on the dripping rocks of the 
Wissahicon and various railroad cuttings. At certain times the cells are found 
crowded with endochrome, at other times they are almost empty. At certain 
seasons this plant multiplies with great rapidity after a somewhat peculiar fashion. 
Constrictions first appear in the filament at the junctions of the cells, which thus, 
look as though their ends were rounding off. This goes on until the ends of the 
cells are greatly rounded, and are attached simply by their central parts, which 
soon separate. In this way ‘fig. 8b, pl. xv.) the filament is resolved into its com- 
ponent cells, or more generally into as many pairs of cells as compose it, which 
when once set free in the water rapidly grow into filaments by the ordinary pro- 
cess of cell multiplication by division. In most cases the zygospores are placed 
in one of the parent-cells, but I have seen instances in which some of them were 
formed in the connecting tubes. 

Fig. 8, pl. 15, represents this species. 


Z. cruciatum,(Vavucs.) Aa, 

Z. pallide viride, siccatum fuscescens vel fusco-nigrescens; articulis sterilibus brevicylindricis 
diametro (0.0016”—0.00195”) wqualibus vel dimidio longioribus, rarius duplo longioribus, 
post divisionem factam haud raro dimidio brevioribus, fructiferis non tumidis; zygosporis 
plerumque globosis, maturis obscure fuscis, sporudermate subtiliter punctatis. (R.) Species 
mihi ignota. : 

Syn.—Zygnema cruciatum, (VAucHER) AGARDH. RaBeEnuorst, Flora Europ. Algarum, Sect. 

III. p. 251. 


Tyndaridea cruciata, HassauL, Fresh-Water Alge, vol. i. p.160.—Harvey. Barzzy, 
Microscopical Observations, p. 21. 


Hab.—Northern States; Virginia; Florida; Bailey. 


Pale green, when dried subfuscous or blackish fuscous. Sterile joints shortly cylindrical, equal or 
a little longer, or more rarely twice as long as broad (diam. 0.0016”—0.001 95”), after division 
sometimes shorter than broad ; fruiting -cells not tumid; zygospores mostly globose ; -when 
mature, obscure fuscous, their coat minutely punctate. 


Genus SIROGONIUM, Kz. 


“ Cellule vegetative cylindrice, sporifere subinflate orculiforme. Fascie chlorophyllose longi- 
tudinales, parietales, leviter flexuose, nodose (plerumque 2-3, rarius 4 in quaque cellula), granula 


amylacea 7-8 involute. Copulatio genuflexa, sine tubo connexivo.” RB. In specie Americana 
fascie chlorophyllose spirales et Spirogyre illis similes. 


Vegetative cells cylindrical, spore bearing cells somewhat inflated, or orculiform. Chlorophy] fila- 
ment longitudinal, parietal, somewhat flexuous, nodose (mostly 2-8 rarely 4 in each cell), containing 
7-8 starch granules; conjugation genuflexuous, without any connecting tubes. (Rabenhorst). In 
American species the chlorophyl filament spiral and like to that of Spirogyra. 


Remarks.—This genus was originally made by Kiitzing to contain a single 
species, which possesses the characters given in the diagnosis of Prof. Rabenhorst 


FRESH-WATER ALG&A OF THE UNITED STATES. 173 


I have met with an American plant, which has some of these characters, and at the 
same time others which have been supposed to belong to the genus Spirogyra. It 
unites the method of reproduction of Strogonium and the arrangement of the 
chlorophyl band of Spirogyra, standing as it were midway between them. It is 
not midway, however, but much nearer Sirogonium, for the passage from a very 
loose spiral to a longitudinal flexuous filament is a brief one, and although in some 
cells of S. retroverswm the spiral makes a number of turns; in other long cells it 
scarcely gets around once, in other words the chlorophyl band is nearly straight. 
On the other hand, the reproduction is strictly that of S. strictum, at least in 
all cases which have come under my notice. There is, therefore, but one of two 
things to be done, either to unite Sirogoniwm with Spirogyra, or else to give up 
the arrangement of the chlorophyl as an essential character of the former genus. 
The great variance, in the latter respect, in our American species, greatly weakens 
the value of any such character, and I have, therefore, preferred the latter of the 
two courses, . 


S. retroversum, Woop. 

S. articulis sterilibus diametro 7-15 plo longioribus; fasciis spiralibus 1, rare 2, latis, granu- 
latis ; anfractibus 1-9; articulis fertilibus valde tumidis, retroversis ; conjugatione genuflexa et 
sine tubo connexivo; cytiodermate nonnihil crasso, utroque fine protenso vel replicato ; 
sporis ellipticis. 

Diam.—Art. steril. 714,” =.00146” ; spor. lat. 719,”—7125” =.00133”—.0016”; long. 7235” 

= 0033", 
Syn.—S. retroversum, Woop, Prodromus, Proc. Am. Phil. Soc. 1869, p. 139 
Hab.—In stagnis, prope Philadelphia. 


Sterile joints 7-15 times longer than broad ; chlorophyl band 1, rarely 2, broad, granulate ; 
turns 1-9; fertile article very tumid, retroverted ; fertile cells scarcely swollen ; cell wall folded 
in at the ends; chlorophyl band single; turns 6; spores oblong or elliptical, spore wall very 
thick. 


Remarks.—I have found this species growing in stagnant ditches in the Neck 
below the city. In fruit the cells are almost always very markedly bent backwards, 
and have a broad pouch-like dilatation in front. The spores are elliptical, and, as 
I have seen them, greenish and with a thin coat, but may not have been completely 
matured. 

Fig. 1, pl. 16, represents this species. 


Genus MESOCARPUS, Hassatt. 


Cellule massa chlorophyllosa initio diffusa, postea in fasciam longitudinalem, haud raro flexuosam 
contracta; nucleum centralem et granum amylaceum unicum vel duo involvens. Zygospora globosa 
vel ovata, in tubo connexivo inter cellulas binas plus minus genuflexas formata. 


Chlorophy!] mass in the beginning diffused in the cell, afterwards contracted into an often flexuous 
fascia, and involving a central nucleus and one or more starch granules. Zygospore globose or 
ovate, formed in the connecting tube between two more or less bent cells. 


MI. scalaris, Hassatt. 
M. cellulis sterilibus diametro 3-6 plo longioribus, fertilibus valde curvatis ; zygosporis ovalibus. 


Diam.—Max. 7835 = .0011”". 


174 FRESH-WATER ALG OF THE UNITED STATES. 


Syn.—. scalaris, HassauL, Fresh-Water Alge, vol. i. p. 166, et RABENHORST, Flora Europ. 
Algarum, Sect. III. p. 257. 

Hab.—In fossis, prope Philadelphia. 

Sterile cells 3-6 times longer than their diameter, fertile strongly curved; zygospores oval. 


’ Remarks.—This species is abundant in the stagnant ditches near Camden. It 
agrees well with the descriptions of the European form. I have, however, never 
seen it in the state in which it has “fuscous spores.” They have always been 
greenish, but yery possibly were not fully matured. 

Fig. 5, pl. 15, represents a pair of cells of this species just commencing to con- 


jugate. 


M. parvulus, Hassatt. 
M. cellulis diametro (0.00031”—0.00041") 5-12 plo longioribus ; zygosporis globosis, plerumque 
0.00062” latis, sporodermate fusco levi. (R.) Species mihi ignota. 
Syn.—H. parvulus, Hassan, Fresh-Water Alge, vol. i. p. 169, et RassnHorst, Flora Europ. 
Algarum, Sect. III. p. 257. 


Hab.—Rhode Island; (8. T. Olney) Thwaites. 


Cells 5-12 times longer than their diameter (0.00031’—0.00041”) ; zygospores globose, mostly 
0.00062” broad, spore coat fuscous smooth. 


Genus PLEUROCARPUS, A. Braun (1855). 


a 


Cellule eedem que in Mesocarpo; copulatio lateralis et sporifera, nonnunquam genuflexa et 
plerumque sterilis. (R.) 

Cells like those in Mesocarpus ; conjugation lateral and sporiferous, somewhat genuflexuous and 
mostly sterile. 


P. mirabilis, Braun. 
P. cellulis diametro (0 0011”—0.0013”) 2-5 plo longioribus; zygosporis subglobosis, fuscis, 
levibus. (R.) Species mihi ignota. 


Syn.—Mougeotia genufleza, AcaRDH. Batxey, Silliman’s Journal. New Series, vol. iii. 
Pleurocarpus mirabilis, A. BRAUN. RaBENHORST, Flora Europ. Algarum, Sect. III. p. 
258. 


Hab.—West Point, New York; Providence, Rhode Island; Detroit, Michigan; Fort Winne- 
bago, Wisconsin; Bailey. 
Cells 2-5 times longer than their diameter (0.0011"”—0.0018”) ; zygospores subglebose, fuscous, 
smooth. 


Orper Siphophycez. 


Alge unicellulares. Cellula utriculiformis, plerumque ramulosa; ramuli vegetatione terminali 
prediti, sepe demum septo discreti, et alteri in oosporangia, alteri in antheridia transmutantur. 
Cytioplasma, viride, granulosum, mucilaginosum, vesiculis chlorophyllosis et granulis amylaceis 
repletum. Propogatio fit aut cytiogenesi libera, aut zoogonidiis aut oosporis. 


Unicellular alge. Cells utriculiform, mostly branched; branches with a terminal vegetation 
often finally cut off by a partition wall and transformed into antheridia or oosporangia. Oytioplaam 
green, granular, mucilaginous, filled with chlorophyl vesicles and starch granules. Propogation 
either by forming minute spores by free cell formation, or by zoospores, or by oospores. 


FRESH-WATER ALGA OF THE UNITED STATES. 175 


Famity HYDROGASTREA. 


Plantule minima, terrestres, gregaria. Cellula initio globosa, postea clavato- vel pyriformi- 
intumescens, basi attenuata elongata et in ramulos subtillissimos hyalinos partita. Cytioplasma 
mucilaginosum, «tate provecta gonidia divisione simultanea transformatum. Oytioderma lamellosum 
ztate provecta dilabens et contabescens et gonidia liberans. 


Plants very small, terrestrial, gregarious. Cells in the beginning globose, afterwards clavate or 
pytiform, with an elongated, attenuated base, divided into very fine, hyaline branches. Cytioplasm 
mucilaginous, at maturity transformed by a simultaneous division into gonidia. Cytioderm lamel- 
late, at maturity wasting, withering away and setting free the gonidia. 


Remarks.—The Hydrogastree are curious little unicellular plants, which grow 
upon wet earth. The matured frond is swollen up at one end to form a subglobular 
or pyriform head, whilst at the other end it is produced into a long, much-branched, 
very fine root-like portion which enters the earth and maintains the little plant in 
its upright position. The green endochrome is contained almost entirely in the 
head, and forms generally a coat or layer in the outer portion of its cavity, the inner 
part of which appears to be occupied by a watery fluid. 

The only specimens which I have seen of this family were found growing in the 
mud left by the receding water of a recently drawn mill pond, by Dr. Billings, U.S. A. 
When I got them they were thoroughly dried up, and consequently no opportunity of 
studying their development was afforded. According to Kiitzing and Braun, the 
species is propagated ordinarily by the breaking up of the chlorophylous layer of pro- 
toplasm lining the wall of the cell into a larger number of very small globular spores. 
These, although not endued with the power of motion, seem from their method 
of formation and history to be homologous with zoospores. In most cases they 
are set free by the membrane of the parent-cell becoming gelatinously softened, 
swelling up, collapsing, and finally dissolving away. The little protococcoid cells 
then enlarging, develop at one end a hyaline prolongation which penetrates into 
the ground. Growth and development continuing the upper end of the cell swells 
up into the ovate or globular head, whilst the lower becomes the hyaline, branch- 
ing, root-like portion of the new frond. No indication of this method of repro- 
duction was discoverable in the plants which Dr. Billings sent me. The evident 
affinities of the family with the Vaucheriacew render it exceedingly probable that 
there is in it some method of sexual reproduction, as yet undiscovered, allied to 
that which occurs in the latter. In some of the specimens sent me, there were 
what appeared to be resting-spores (pl. XVI., fig. 2. a), occupying the whole of the 
cavity of the cell, from which they appeared to be finally discharged by a decay 
and rupture of the outer coat or wall. How these bodies were formed, and whether 
they really have power to reproduce the species I cannot tell. 


Genus HYDROGASTRUM, Dzsv. 


Character idem ac familie. 
Characters that of the family. 


H. granulatum, (Liny.) Desv. 
H. plerumque gregarium, sepe aggregatum, haud raro confluens; cellula e globoso-pyriformi, 
magnitudine seminis papaveris vel sinapios et ultra, prasino-viridi superficie pulverulenta, (R.) 


176 FRESH-WATER ALG OF THE UNITED STATES. 


Syn.—Botrydium argillaceum, WaLLROTH. RABENHORST, Flora Europ. Algarum, Sect. III. 
p. 265. 
Hydrogastrum granulatum, (Linnaus) Dzsv. RaBenworst, loc. cit. 


Hab.—Delaware; (Dr. Billings) Wood; West Point, New York; Providence and Newport, 
Rhode Island; Bailey. 


Mostly gregarious, often aggregate, not rarely confluent; cells pyriform, of the size of a poppy 
- or mustard seed and larger; pea-green; surface pulverulent. 


Remarks.—-The above description is taken from Rabenhorst’s work, and applies 
to the specimens collected by Dr. Billings in the State of Delaware, excepting that 
I did not discover any of them to be confluent, nor was their surface distinctly 
pulverulent. Prof. Kiitzing gives as a comparative character between this and H. 
Wallrothii, the smaller size of the spores; but Prof. R. says nothing about this. 
There were no spores in any of the American specimens, and I think it somewhat 
uncertain whether or not the plant is or is not either of the European species. It 
is very probable that it will be discovered that the only true specific characters are 
sexual, and consequently have not as yet been made out in any of the forms. 
Certainly the descriptions of the species as at present given seem to me not to 
contain any reliable characters. 

Fig. 2 a, pl. 16, represents a very young state of our American plant; fig. 2 is 
the perfected frond, both magnified ninety diameters; fig. 2 a shows what is sup- 
posably a perfected resting spore magnified 160 diameters. 


Famiy VAUCHERIACEA. 


Alge monoice, cespitose, unicellulares. Cellula vegetiva (thallus) vegetatione terminali, utriculi 
formi-elongata et ampliata, prominentiis plus minus elongatis ramosa. 

Propagatio aut sexualis, fit oosporis ope spermatozoidiorum fecundatis, aut non sexualis zoogonidiis. 
Fructificatio triplex (melius organa fructificationis tria) :— 

1. Sporangium terminale, ex thalli apice plerumque globoso-clavato-tumido formatum, septo dis- 
cretum, cytioplasmate obscure viridi, demum in zoogonidium (zoosporam, Thur.) unicum permag- 
num, ciliis vibratoriis dense obsitum abeunte farctum. 

2. Oogonium (cosporangium) laterale, sessile vel prominentia, plus minus elongata vel simplici 
vel partita pedicellatum, cytioplasmate state provecta in oosporam singulam transmutato fetum. 

8. Antheridium laterale, sessile vel e ramuli lateralis parte suprema septo discreta formatum, in * 
quo spermatozoidea (antherozoidea, Thur.) numeros issima nascuntur, denique erampunt. Sperma- 
tozoidea oblonga, ciliis duobus inzequilongis, subpolo antico ortis instructa. (R.) 

Monecious alge, cespitose, unicellular. Vegetative cells (thallus) growing at the ends, elongate, 
utriculiform, and ampliate, more or less profusely branched. ’ 

Propogation either sexual, with oospores which are fecundated by spermatozoids, or non-sexual, 
by means of zoospores. Organs of fructification of three kinds :— 

1. Sporangia, which are terminal and mostly formed from the separation of clavately swollen, 
globose apex of the thallus (often of a branch) by means of a partition; in the sporangium arises 
a single, very large zoospore, which is densely clothed with cilia. 

2. Oogonia (oosporangia), lateral, sessile or pedicelate simple bodies, whose eytioplasm is finally 
converted into an oospore. 

3. Antheridium lateral, sessile, or formed out of the end of a branch; the spermatozoids formed » 
in them oblong, furnished with two unequal cilia, arising near the front end. 


FRESH-WATER ALG#A OF THE UNITED STATES. 177 


Remarks.—The Vaucheriacee are amongst our most common fresh-water alge. 
They occur generally in the form of vast numbers of individuals interwoven into 
broad mats, which have often both a felty look and feel. When growth is going 
on rapidly, these mats are of a beautiful vivid green; but when the process of 
sexual reproduction has checked the life of the individual they become dingy and 
dirty looking. The thallus is composed of a single cell and is almost always 
branched. The branches never have, at least in any of our species, a definite 
arrangement, save only in that they always arise from the side and not from the 
point of the thallus. In the European species, V. tuberosa, however, the branches 
are said to arise both from the point and sides of the frond. 

The frond cell is generally nearly uniform in diameter and has a thick outer 
wall, which is composed of cellulose, as is proven by the action upon it of iodine 
and sulphuric acid and of the iodo-chloride of zinc solution. Within the cell are 
chlorophyllous protoplasm, starch granules, watery fluid, and a few scattered 
raphides or inorganic crystals. There is never any nucleus. The protoplasm is 
often very granular, and is mostly collected in a thick green layer upon the inner 
surface of the cell wall, leaving the centre of the cell free for the more watery 
contents. 

Growth, except in the very young fronds, consists exclusively in an increase in 
length, and takes place only at the ends of the thallus or in the portions near it. 
The branches are almost always simple, but are said in some species to give origin 
to secondary branchlets, and even, at times, to tertiary ones. They grow in the 
same manner as the main thallus, 7. e. by additions to their ends. 

When the thallus of a Vaucheria is ruptured by external injury, or, at times, 
when it is dying from some hidden cause, a number of bright green globes of 
various sizes are formed out of the endochrome. ‘These appear to have the power 
of independent existence for some time, but whether or not they ever actually 
grow into new thalli I am unable to state. 

M. Walz asserts that he has observed in certain species the formation of a quiet 
spore without the intervention of sexual organs, and that the process is as follows. 
The end of a long or short twig swells up, and the chlorophyl and protoplasm from 
the neighboring parts accumulate in the enlarged portion. A partition wall then 
forms at the base of the latter, which is thus changed into a closed chamber, a 
sporangium. The green contents then slowly gather themselves together into a 
denser and denser ball, becoming more and more separated, in so doing, from the 
wall of the sporangium, and finally secreting around themselves a distinct mem- 
brane. After the formation of a spore in this way, the sporangium opens at the 
apex and allows it to escape. The spore, after remaining quiet for some time in 
the water, at last germinates into a new frond, in a similar manner to an ordinary 
zoospore. In my earlier studies of fresh-water alge, I noticed something very 
similar to this in one of our species, but convinced myself that the little body was 
nothing but a zoospore, whose normal development had been perverted by unto- 
ward influences, and therefore paid no more attention to the matter. It is proba- 
ble that the life-hjstory of the bodies observed by M. Walz is capable of the same 


explanation. 
23 August, 1872. 


178 FRESH-WATER ALGA OF THE UNITED STATES. 


Although I have very frequently cultivated Vaucherias, I have never been so 
fortunate as to see them form their zoospores, nor indeed to see a zoospore in its 
motile state. The life-history of these bodies has, however, been fully and repeat- 
edly worked out by other observers. It is described by such as occurring in the 
following manner. One end of a branch first enlarges into a bulbous, often conical, 
point, into which the neighboring endochrome crowds itself. ‘This point is next 
divided off by a partition wall from the remainder of the thallus and constitutes the 
zoosporangium, the contents of which rapidly condense into one or two masses, 
generally oval in shape, each of which eventually forms a zoospore. When the 
latter are matured, the apex of the zoosporangiwm opens, and the little bodies 
within slowly and gradually emerge, without any apparent cause for their motion. 
Sometimes, according to Cohn, instead of this steady outward passage, there are 
repeated forward and backward movements of the zoospores within the case. The 
zoospore after its perfection is generally oval, and very large. Within it there are 
one or more vacuoles, and surrounding it is a layer of colorless protoplasm. It is 
remarkable for having its whole surface densely covered with short cilia. Its period 
of motile life appears to be very brief; according to Walz, that of the zoospore of 
V. sericea, Lyngb., lasts only from one-half to one and a half minute, after which 
time the cilia are lost and a cellulose wall secreted around the mass. Germina- 
tion takes place by the growth of the cylindrical thread out from each end of the 
zoospore, 

True sexual reproduction takes place in this family by means of antheridia and 
oogonia, male and female organs. All known species are mostly if not absolutely 
monzcious, both organs being contained in the one individual and always placed 
in proximity. All of the species in which the development and structure of the 
sexual organs have been studied, agree in the essential points, 

The first appearance of the antheridium is as a little pouch projecting out from 
the side of the thallus, This increases in size and soon assumes the peculiar shape 
of the species. At the same time there is a diminution, according to M. Walz, of 
the chlorophyl in the antheridium, so that, when the partition wall forms and shuts 
off the cavity of the latter from that of the thallus, there are only a very few scat- 
tered green granules remaining. The antheridium at the time of separation con- 
tains, therefore, only transparent protoplasm, which soon becomes granular, and 
shortly afterwards exhibits the moving spermatozoids, which appear to be formed 
out of the thick layer of protoplasm that lines the inner surface of the cell wall. 
The point of the antheridium opens so soon as the spermatozoids are perfected, 
and allows them to escape, 

The formation of the oogonia takes place very similarly to that of the antheridia. 
There is the same little protrusion from the side of the thallus in the commence- 
ment of the process, the same after-growth and increase of this pouch, and the same 
formation of a separating wall between it and the main body of the frond. A very 
marked difference, however, is to be found in the contents of the two, the oogonium 
from the very commencement being crowded with chlorophyl and oil globules. 
When the oosporangium is completed, the end of it opens, and, at the same time, 
the contents gather themselves into a dense protoplasmic ball, which lies in the 


FRESH-WATER ALGA OF THE UNITED STATES. 179 


centre. The spermatozoids, which are at this time already free in the water, are very 
minute, longish, ellipsoidal or ovate masses, provided with two unequal cilia. These 
commonly both arise together from one end of the body, and are directed in oppo- 
site directions—one backwards, the other forwards. According to M. Walz, how- 
ever, in V. sericea the cilia arise from the opposite ends. According to De Bary, 
the spermatozoids of V. aversa, Hassall, contain reddish pigment-granules. M. 
Walz states that he has twice seen the process of impregnation in V. sericea, Lyngb., 
and describes it essentially as follows: After the bursting of the antheridium and 
the formation of the opening in the oogonium, the spermatozoid clustered around the 
little orifice in the latter, but were apparently debarred entrance by the presence of 
a glutinous jelly. After a time, however, one, and then another, forced a passage 
through this obstacle until finally a number gained access to the protoplasmic ball 
within. Over this they swarmed, pushing it and retiring and butting against it 
until some of them actually forced their way into it and were absorbed by it. Im- 
pregnation being now completed, the oospore acquired a very sharp definite outline, 
and secreted in a very short time a membrane around itself. The changes which 
followed during its maturing consisted of the acquiring of a thick coat and the 
replacing of the chlorophyl within by a reddish-brown coloring matter. The ripened 
resting spore of almost all the Vaucheria is provided with three coats, of which the 
middle is the thickest. The contents consist of protoplasm, reddish-brown pigment, 
and numerous oil globules. : 


Genus VAUCHERIA. 


Genus unicum, character idem ac familie. 
The only genus of the family, having the same characters. 


V. sessilis, (Vaucu.) Dz Canpoute. 

V. laxe intricata, pallide et subsordide viridis; thallo capillari, parce ramoso; oogoniis 2-3 
approximatis, rarius singulis, ovatis vel ovali-oblongis, plus minusve obliquis, rostratis; anthe- 
ridio intermedio, ramuli modo brevi hamato, modo recto subulato, subclavato, modo elongato 
et incurvato, haud raro circinato sustentato; oosporis maturis fusco-punctatis, membrana 
triplici involutis. (R.) 


N 


Syn.—V. sessilis, (Vaucn.) De Canpotiz. Rasenuorst, Flora Europ. Algar., Sect. II. p. 
267. 
V. cespitosa, (VaUCH.) AGARDH. RaBENHORST, loc. cit. 


Hab.—Salem, North Carolina; Schweinitz. Common at West Point, New York; Waterville, 
Maine; Culpepper Co., Va.; Bailey. 


Laxly intricate, pale and subsordid green; thallus capillary, sparsely branched ; oogonia 2-3, 
approximate, rarely single, ovate or oval-oblong, more or less oblique, rostrate; antheridia 
intermediate, sustained upon branches partly shortly hamate, partly straight subulate, sub- 
clavate, partly elongate and incurved, and not rarely circinnate ; oospores at maturity, fus- 
cous-punctate, surrounded by a three-fold membrane. 


Remark.—I think I found this species near Philadelphia in my earliest re- 
searches, but cannot speak certainly, having preserved neither notes nor specimens. 


180 FRESH-WATER ALG&Z OF THE UNITED STATES. 


V. velutina, Ac. 
V. thallo repente, ramulis erectis, numerosis, fastigiatis, in ceespitem velutinum lete viridem 
intricatis ; oogoniis lateralibus singulis, globosis, sessilibus, antheridio paulo longiore unico 
subulato leviter incurvato consociatis (R.) Species mihi ignota. 


Diam.—Oogonii 0.0023”—0.0027". (R.) 

Syn.—V. velutina, AGARpH. Rasennorst, Flora Europ. Algarum, Sect. III. p. 274. 

Hab.—Salem, North Carolina; Schweinitz. Common at West Point, New York; Waterville, 
Maine; Culpepper Co., Va.; Bailey. 

“ Filaments exceedingly tough, interwoven into a dense, velvety, green stratum, pellucid below 


and creeping over the mud; branches near the extremity erect, fastigiate, and more or less 
crooked; vesicles solitary, globular, on short lateral peduncles.” Carmichael. 


V. geminata, (Vavucu.) Dz Canpo.tz. 

V. obscure vel sordide viridis, in cespites dense intricata; thallo capillari, tenaci, dichotomo ; 
oogoniis duobus (rarius 1 vel 3), ovatis vel obovatis, oppositis, distincte pedunculatis, antheridio 
intermedio subulato, plus minus recurvo; oosporis maturis fusco-maculatis, sporodermate 
achroo e stratis tribus composito involutis; sporangiis in eodem vel proprio thallo, cyathiformi- 
ampliatis truncatis et angulato-cornutis. (R.) 


Syn.—V. geminata, (Vaucu.) Dr CanDOLLE. RaxBenuorst, Flora Europ. Algarum, Sect. ITT. 
p. 269. 


Hab.—In stagnis, prope Philadelphia; Wood. 


Obscure or sordid green, densely interwoven into a turfy mass; thallus capillary, tenacious, 
dichotomous; oogonia two (rarely 1-3), ovate or obovate, opposite distinctly pedunculate, 
antheridia intermediate, subulate, more or less recurved; oospores at maturity spotted with 
fuscous, their coat transparent and composed of three strata; sporangia in the same or a sepa- 
rate thallus swollen cup-shaped, truncate and horned at the angles. 


Remarks.—I have found this species in fruit but once, then it grew in a ditch 
below the city. Not having mounted any of it, nor having written a description 
of it at the time, I have been forced to simply copy that of Prof. Rabenhorst. 


V. polymorpha, Wooo. 


V. in exspites dense intricata; thallo capillari, tenui; antheridiis corniculatis ex ramuli lateralis 
apice formatis; ramulis fertilibus interdum et oogoniis et antheridiis instructis, interdum 
antheridiis solum ; oogoniis plerumque geminis, interdum singulis, globosis vel ovatis, seepe 
breve rostratis, plerumque distincte pedunculatis sed rarius sessilibus; oosporis enormiter 
subglobosis vel ovatis; sporodermate achroo, e stratis duobus composito. 


Syn.— V. polymorpha. Woop, Prodromus, Proceedings Amer. Philos. Society, 1869, p. 140, 
Hab.—In aquis, prope ‘‘ Buffalo Bayou,” Texas; (Ravenel. ) 


Cespitose ; thallus hair-like, thin; antheridia corniculate, formed of the apex of lateral branches ; 
fertile branches sometimes furnished both with oogonia and antheridia, sometimes with 
antheridia alone ; oogonia sometimes single but mostly in pairs, occasionally shortly rostrate, 
generally distinctly pedunculate but sometimes sessile; oospores irregularly subglobose or 
ovate, surrounded by a transparent double spore coat. 


Remarks.—This species was collected by Prof. Ravenel near the city of Houston, 
Texas. As I received the mass, it was labelled as being obtained from “a shallow 
slimy pool formed by drippings from the side of a ravine near Buffalo Bayou.” 
The species probably grows in the water, evidently forming turfy mats. It is 


FRESH-WATER ALGA OF THE UNITED STATES. 181 


remarkable from the fact that, whilst in many cases the little branches which pro 
duce the antheridia give origin to the spores also, in others they do not; so that 
there are numerous antheridia, which are unconnected with any female organs. 
When a branch does produce both of the reproductive organs it usually forks into 
three short branchlets, thus giving origin to a pair of sporangia and a single curved, 
hooked antheridia. Sometimes, however, there is but a single female branchlet, 
and I have even seen a sporangium, immediately sessile upon a branch, which at 
its apex gave origin to a male organ. In the coat of the perfected spore, I have 
not been able to find more than two distinct strata. 

Figs. 3 and 3a, pl. 20, represent sporangia and antheridia of this species; 3 4, 
a simple, young and only partly formed antheridia, magnified 160 diameters ; 3 ¢, 
a perfected spore magnified 260 diameters. 


V. sericea, Lynesye. | 
Y. aquatica vel terrestris, cespitosa, vel sordide vel lete vel luteolo-viridis; thallis tenuibus, 
dense intricatis, laxe et vage ramosis, ramisque sepe adscendentibus vel erectis ; oogoniis ses- 
silibus vel brevissime pedicellatis, 1-6 seriatis, unilateralibus, oblique et enormiter ovalibus, 
ore laterali producto rostellatis; antheridiis in thallo ipso juxta oogoniis sessilibus, cylin- 
draceo-subclavatis, deflexis; spermatozoideis oblongis, puncto rubro notatis (teste de Bary), 

in utroque polo cilio unico preditis. 


Syn.— V. aversa, Hassat, Fresh-Water Alge, p. 54. 
V. sericea, LYNGBYE. RABENHORST, Flora Europ. Algarum, Sect. III. p. 271. 
Hab.—-Prope Philadelphia; Wood. 


Aquatic or terrestrial, occurring in turfy mats of a yellowish, dirty, or bright green color; fronds 
thin, densely intricate, laxly and vaguely branched, often together with the branches ascending 
or erect; oogonia sessile or very shortly pedicellate, 1-6 seriate, unilateral, obliquely irregu- 
larly oval, their lateral mouths produced into a rostellum or beak; antheridia sessile upon the 
thallus itself near the oogonium, somewhat cylindrical, subclavate, deflexed especially in age; 
spermatozoids (according to De Bary) oblong, marked with a red point and furnished with a 
single cilia at each end. 


Remarks.—I can perceive no constant differences between V. sericea, Lyng. and 
V. aversa, Hass. The extreme forms differ somewhat, but both are very common 
about Philadelphia, and everywhere grade into one another, Prof. Rabenhorst 
thinks that the two forms are scarcely distinct, and states that the most character- 
istic differences are, that in V. aversa, the thallus is much thicker, and the oogonia 
larger and more erect, whilst the oospores are smaller and consequently do not fill 
the cavity of their case. ‘These differences are, except the last, simply differences: 
in size, and seem to me to depend simply upon circumstances of growth. The rela- 
tively smaller size of the spore is a very frail hook indeed to hang a species upon. 

The plant grows in springs and actively running water abundantly in this neigh- 
borhood ; also on very wet ground, especially on that which is habitually overflowed, 
such as the face of dams, neighborhood of springs, &c. In the water, it is frequently 
on the ground, but also often clothes such objects as stones, largish sticks, &c. 


Orvrr Nematophycez. : 


Alge multicelullares, chlorophyllose, membranacee vel filamentose, ramificatione aut instructs 
aut destitute. Propogatio fit aut oosporis aut zoogonidiis, sed nunquam conjugatione. 


182 FRESH-WATER ALG OF THE UNITED STATES. 


Multicellular, chlorophyllous algs, membranaceous or filamentous, furnished with or destitute of 
branches. Propagated by oospores or zoospores, never by conjugation. 


Famity ULVACE. 


Thallus membranaceus vel foliaceus, vel filiformis (Schizomeris?) rarius crustaceus, e cellularum 
strato unico formatus, aut expansus aut tubuloso- vel vesiculoso-concretus. 

Propogatio fit zoogonidiis, cytioplasmatis divisione repetita ortis. Zoogonidia oblonga, polo 
antico ciliis vel binis vel ternis vel quarternis instructa. 


Thallus membranous or foliaceous, rarely crustaceous, composed of a single stratum of cells, either 
expanded or tubularly or vesicularly concreted. 

Propagation by means of zoogonidia, formed by the repeated division of the cytioplasm. Zoogoni-. 
dia oblong, furnished with two, three, or four cilia at the anterior end. 


Genus PROTODERMA, Krz. 


Thallus crustaceus, indeterminatus, substrato arcte adherens, e cellulis anguloso-rotundatis, 
irregulariter ordinatis, arcte connexis compositus. 

Propagatio ignota. 

Thallus crustaceous, indeterminate, closely adherent to the substratum, composed of closely con- 
joined irregularly arranged angularly rounded cells. 

Propagation unknown. 


P. viride, Krz. 
P. viride, lubricum. 
Syn.—P. viride, Kurzine. Rapennorst, Flora Europ. Algarum, Sect. III. p. 307. 
Hab.—In aquario; Wood. 
Green; slippery. 


Remark.—I have seen a plant, which I take to be this species, growing on the 
glass and on pebbles in the aquarium of my friend, Dr. Frické. 


Genus ULVA, Linn. 


Thallus membranaceus, plane expansus, angustus vel latus, nonnunquam latissimus, magis minusve 
undulato- crispatus, sepe laciniatus, haud raro perforatus, e cellularum strato unico formatus, callo 
disciformi parvo affixus, etate provecta spe libere natans. Cellule anguloso-rotundate, cceloplas 
matice, parenchymatice connexe. 

Vegetatio cellularum divisione in duas directiones repetitia. Propogatio fit zoogonidiis, in cel- 
lulis quibusdam cytioplasmatis divisione 4, 8-16 ortis, ciliis vibratoriis quaternis longitudine cor- 
poris longitudinem vix superantibus instructis. 


Thallus membranous, expanded, narrow or broad, sometimes very broad, more or less undulately 
curled or crisped, often laciniate, not rarely perforate, formed of a single stratum of cells, fastened 
by a small discoid thickened portion, in advanced age often swimming free. Cells angularly glo- 
bose, joined into a sort of parenchyma. 

Growth occurring by the repeated division of the cells in two directions. Propagation by 
zoospores, 4~8-16 of which are formed at once by a division of the endochrome of certain cells, 
and are furnished with four vibratile cilia scarcely longer than the body, 


U. merismopedioides, Woop. 

U. ampla, membranacea, late expansa, dilute viridis, tenuis, radiatim et enormiter plicata, ambitu 
sepe subrotundata; margine undulato, interdum subcrenato; cellulis enormiter ovalibus vel 
angularibus, nucleo destitutis, quarternariis et in familias Merismopediarum modo obscure 
associatis. 


Diam.—Cell. max. yxhqn" = 00041’, plerumque 75359” —ya350” = .00016' — .00025. 


FRESH-WATER ALGA& OF THE UNITED STATES. 183 


Syn.—U. merismopedioides, Woon, Botanical Report of the United States Geological Ex- 
ploration of the Fortieth Parallel, p. 415. 


Hab.—In torrentibus, Diamond Range (alt. 6000 ft.), Rocky Mountains; (Sereno Watson) Wood, 


Thallus ample, broadly expanded, membranaceous, dilute green, thin, radiately and irregularly 
plicate with its outline often somewhat rounded; its margin undulate or at times almost 
crenate; the cells irregularly oval or angular, destitute of nucleus, quarternary and obscurely 
arranged in families after the manner of a merismopedia. 


Remarks.—The largest fronds of this species that have come under my notice 
are about three inches long by two broad, thin, easily torn, and not all gelatinous. 
The portion by which they have been attached is very evident, near one of the 
margins, and from it broad undulations or folds radiate. Sometimes the frond is 
split up into palmate, lobe-like parts. 

The cells are not closely approximate, but are placed in a homogeneous translucent 
membrane, in such a way as to remind one of a Merismopedia. 

I do not feel certain that this plant is distinct from U. orliculata of Rabenhorst, 
though for the present I have preferred so to consider it. His description is very 
brief and incomplete, as is also the original one of Thuret, which I have con- 
sulted. Prof. R., however, gives U. latissima of authors as a synonym of U. or- 
biculata, and certainly this plant is distinct from U. latissima, Harvey, of our 
coast. Again it seems impossible that a plant growing near the summit of the 
Rocky Mountains should be identical with one found on the coast of France. 
Prof. Sereno Watson found this plant growing on rocks in a mountain stream of 
the Diamond Range, at an altitude of 6000 feet. 


Genus ENTEROMORPHA, Link. 


Thallus membranaceus, tubulosus vel utriculiformis, basj affixus (saltem initio, postea seepe libere 
natans), e cellularum strato unico compositus, sepe ramosus, haud raro ramosissimus. Propogatio 
fit zoogonidiis. Hse zoogonidia proceantur in cellulis quibusdam 8-16 cytioplasmatis divisione 
repetita, in polo antico rostriformi ciliis duobus corpus duplo superantibus pradita. (R.) 

Thallus membranaceous, tubular or bladder-shaped, affixed by the base (at least in the beginning, 
often afterwards floating freely), composed of a single stratum of cells, often branched, not rarely 
very much branched. Propagation by means of zoospores, 8-16 of which are formed by the 
repeated division of the protoplasm of a cell. Their anterior beak-like portion provided with two 
cilia whose length is not less than twice that of the body. 


E. intestinalis, (Livy.) Lins. 

E. teres, forma et magnitudine admodum varia, sepe pedalis etiam supra, leptoderma, saturate 
vel pallide viridis, filiformis vel intestiniformis, plana vel bullosa; cellulis 3-5-6 angularibus. 
(R.) Species mihi ignota, 

Diam.—0.00048” — 0.0008”. (R.) 

Syn.—E. intestinalis, (Linnzxus) Batxey, Silliman’s Journal, N. §., Vol. IIL, et Rapengorsr, 
Flora Europ. Algarum, Sect. IIT. p. 312. 

Hab.—Hudson River, from Newburgh to New York City; Narragansett Bay, Rhode 

Island; Bailey. 

Terete, very various in size and shape, often a foot or more in length, smooth, deep or pale 

green, filiform or intestiniform, plain or bullose ; cells 3-5-6 angular; their diameter 0.00048’ 


— 0.0008". 


184 FRESH-WATER ALG OF THE UNITED STATES. 


ay 


Genus SCHIZOMERIS, Krz. ? 


Thallus filliformis, cylindricus, hic illic valde contractus, basi attenuata affixus. Vegetatio fit cel- 
lularum divisione initio in duas postea in tres (?) directionem. Propogatio fit zoogonidiis. Zoogo- 
nidia in thalli juvenis cellulis orta, ovata, polo antico ciliis tribus instructa. 


Thallus filiform, cylindrical, here or there strongly contracted, adnate by the strongly contracted 
base. Growth in the beginning by the division of the cells in two directions, afterwards in three 
directions. Zoogonidia formed in the cells of the young thallus, ovate, their anterior end furnished 


with three cilia. 


Remarks.—The plant from which the above generic description has been drawn 
up grows abundantly in our ditches below the city. Whether it really belongs to 
the genus Schizomeris or is the representative of a new group is somewhat uncer- 
tain. I have never seen the European plant, but, if I understand the descriptions 
of it, the cells in it are all arranged in a single plane. This certainly is not the 
case in the old plants of our North American form, for in them the cells are so 
placed as to make a thick opaque filament, the outside of which everywhere pre- 
sents the outer walls of cells. The life history of the European species has not 
been at all worked out, and I have refrained from actually indicating a new genus, 
in the absence of absolute knowledge upon the subject, because the specific cha- 
racters of the two plants are so much alike. 

I have had some opportunities for studying the life history of our American 
plant. The zoospore (Fig. 1 ¢. pl. X VIT.) is of the ordinary conical or ovate form, 
with a very decided transparent anterior end, from which arise three cilia. As the 
number three is a rare one for cilia to exhibit, I have examined several zoospores 
with care, and am very certain that they had no more or less. It is, therefore, 
probable that the number is fixed for the species, although just possible that my 
finding several individuals in agreement was accidental. The zoospore after a 
period of free life, during which its motion is very active, becomes quiescent, and, 
its cilia withering away, attaches itself by its smaller end to some twig, stone, or 
other support. At the same time it appears to change its shape somewhat, grow- 
ing longer and narrower, and the smaller end spreading out to form a little foot. 
Simultaneously with these changes the young plant acquires a cellulose coat, and 
so becomes a perfect cell, in which I have never been able to detect any nucleus. 
After a while the cell thus formed divides transversely into two, which, of course, 
lay end to end. Each of these cells then grows until it attains a certain size, and 
then the transverse division is repeated. In this way the process goes on until 
finally a long filament is produced, which is composed of but a single series of 
cells. ‘These cells are much broader than long, and are placed end to end, so that 
the cylindrical frond is made up as it were of disks laid one upon the other. 
When the filament has in this way reached a certain stage of development, one of 
two things occurs, either the cells begin to divide at right angles to the plane of 
their previous division, or else the production of zoospores takes place. In the 
first instance each cell divides into two, four, or more cells. This division, I believe, 
occurs in three if not all directions, so that each original cell is represented by a 
number of cells, and a sort of compound filament arises, out of which the matured 


FRESH-WATER ALG OF THE UNITED STATES. 185 


large trichoma is formed by a continuation of growth, and, perhaps, by a repetition 
of the division. I have never been able to discover that any reproductive process 
whatever takes place in this compound filament, and am very confident it never 
produces zoospores, It is very possible, however, that it may in some way give 
origin to resting spores, although, as above stated, no indication of this has ever 
come under my notice. ‘The zoospores are formed in the young fronds as follows: 
The endochrome in the cell concerned gradually separates in the ordinary manner 
into several distinct masses, which soon assume a more or less irregularly globular 
or pyriform shape. Whether the number of these masses is fixed for the single 
cell or not I am unable to state. These changes occur almost simultaneously in a 
number of consecutive cells, commencing with the most distal and rapidly spread- 
ing towards the base of the filament. When they are pretty well advanced, the 
walls of the cells undergo some alteration, probably a gummy degeneration, whereby 
they become soluble in the water. As the division of the endochrome occurs first 
in the most distal cells of the filament, so does also this change in the cellulose coat. 
When the endochrome masses are well shapen and distinct, they begin to exhibit 
motion, becoming uneasy, restless, changing their position, rolling on themselves, 
and pushing against one another. At the same time solution of the cell walls com- 
mences, the partitions between the cells disappearing, and the outer walls spread- 
ing. These changes go rapidly forward, and in a little while the zoospores stream 
out from the fading end of the frond, jostling and crowding as though eager to 
enter upon their new life. : 
Fig. 1 a, pl. 17, represents the basal portion of an old filament which has failed 
to form zoospores, magnified 125 diameters. Fig 1 was drawn from a young 
filament during the process of forming zoospores; owing to their rapid motion, the 
cilia of the latter could not be seen. This figure is enlarged 250 diameters. Fig. 
le represents a zoospore which has just become quiescent, and still retains its 
cilia, although they have lost their motile power. Fig. 1 d, e, c, represent the very 
young plant in different stages of growth. ‘They are all magnified 450 diameters. 


S. Leibleinii, Krz. ? 
8. late viridis vel saturate nigro-viridis. 
Diam.—Max. 73,”.=.08". 
Syn.—S. Leibleinti, Kitzina. Rapennorst, Flora Europ. Algarum, Sect. III. p. 311. 
Hab.—In fossis, prope Philadelphia. 
Bright green to deep blackish-green; largest diameter of the frond 73,". 


Remarks.—Owing to the profusion of zoospores produced by a single filament 
at one time, it is very usual to find large numbers of the younger plants attached 
so closely to some central body as to form dense masses of a beautiful green color. 
The support of these small masses is often entirely concealed, and I have frequently 
seen them moving freely about the jar, without any apparent cause, until the mystery 
was solved by finding that some unfortunate snail carried the forest on his back. 

The oldest filaments are perfectly opaque, showing, under the microscope, by 


transmitted light, no trace of their structure. 
24 August, 1872. 


186 FRESH-WATER ALG OF THE UNITED STATES. 


The species is exceedingly common in the later summer and early fall months 
in the ditches and sluggish streams around the city, especially in the Neck. 


Famity CONFERV ACEA. 


Fila articulata aut simplicia aut ramosa, vegetatione terminali non limitata instructa. Articuli 
plerumque plus minusve elongati, sed nonnunquam diametro breviores, cylindrici, rarius tumidi. 
Cytioderma plerumque manifesto lamellosum. Massa chlorophyllosa granulata, vesiculas amylaceas 
involvens, parietalis vel in etate provecta spe in cellule centro contracta. 

Vegetatio fit utriculi primordialis divisione semper in unam eandemque (transversam) directionem 
repetitia. Propagatio fit zoogonidiis. 

Filaments articulate, simple or branched, growth terminal, unlimited. Joints mostly more or less 
elongated, but sometimes shorter than long, cylindrical rarely tumid. Oytioderm mostly plainly 
lamellate, chlorophyl masses granular, surrounding fine starch granules, parietal or often in the centre 


of the cell. 
Growth taking place by division of the primordial utricle always in one direction, namely trans- 
versely. Propagation by means of zoospores. 


Genus CONFERVA, (Liny.) Linx. 
“ Fila articulata simplicia. Articuli cylindrici. Massa chlorophyllosa homogenea vel granu- 
lata, vesiculas amylaceas involvens. Propogatio ignota.” (R.) 


Threads articulate simple. Articles cylindrical. Chlorophyl mass homogeneous or granulate, 
including amylaceous vesicles. 


Remarks.—A large number of forms of the genus Conferva have been described 
as distinct species by Kiitzing and other authors. The characters assigned to 
these species, however, do not seem to me in any way distinctive. I cannot believe 
it possible at present to recognize, define, and describe species in this genus, and 
believe that further studies must be made in their life-history, and other characters 
discovered before the different forms can be separated. Probably, as was the case 
with the Cidogoniacee, when their sexual life is made out, in it will be found the 
vital differences. No doubt there are many species common to Europe and Ame- 
rica, but I have been entirely unable to determine them. Among the very earliest 
of my observations upon the fresh-water algw, before experience had taught how 
and what to observe, was one made upon what I suppose was a species of this 
genus. I have never met with the plant since, but as the observation has direct 
bearing upon the method of propagation, I mention it here, imperfect as it un- 
fortunately is. The plant was found growing on the mud along the Schuylkill 
River, near Gray’s Ferry Bridge, below the city. The filaments were simple, of 
great length, and uniform in diameter; fig. 7 a, pl. 18, represents a portion of 
one magnified 500 diameters. The cells varied from about as long as broad to 
three times as long. The amount of endochrome in the cells also varied very much, 
In most of them, it was not nearly sufficient to fill the cavity, and was arranged as 
a central superficial band. Many of the cells were seen engaged in the production 
of zoospores. (Fig. 7 6, pl. 18.) Such were well filled with endochrome, which 
gradually condensed itself into a globular or pyriform mass in the centre of the 
cell. This, after a short time, began to exhibit activity, rolling upon itself and 
finally pushing about as much as its confined quarters would allow, until at last it 


FRESH-WATER ALG#H OF THE UNITED STATES. 187 


escaped into the water, through the cell wall. Each cell in this way gave origin 
to a single zoospore. ‘The walls did not melt away in the water, and, as a number 
of consecutive cells underwent these changes at the same time, the filament or a 
portion of it was left as an empty shell. The zoospores were of the usual shape, 
with a bright anterior spot or beak. The number of cilia was not noted. After 
a time they settled down generally in clusters, attaching themselves to some foreign 
particle, dropping their cilia and acquiring a cellulose wall. (Fig. 7e, pl. 18.) They 
then elongated, underwent the ordinary cell division in a transverse direction, and, 
by the repetition of this, gradually grew into filaments similar to that from which 
they sprang. 

Fig. 7 d, pl 18, represents a young filament just formed in this manner, magni- 
fied 500 diameters. 


Genus CLADOPHORA, Krz. (1848.) 


Fila cellularum serie simplici formata, varie ramosa. Rami filo centrali similes. Cytioderma 
plerumque crassum, lamellosum. Cytioplasma parietale. 


Filaments composed of a simple series of cells and variously branched. Cytioderm mostly thick 
and lamellate. Cytioplasm parietal. 


Remarks.—The Cladophora are branched plants of rather rigid habits, which 
grow both in salt and fresh water. They are readily recognizable by their 
comparatively still appearance, the absence of gelatinous matter about them, and 
by the want of regularity in their branching. A large number of species have 
been described, most of which are marine. They are exceedingly difficult to define, 
and it is very possible that their hitherto undiscovered sexual reproduction may be 
finally found to afford the only true characters. I have identified two European 
forms as growing near this city, and a third has been recognized by Prof. Harvey, 
as found in our northern States. . 

I have never seen the production of zoospores in this family, but they are said 
to be formed by the simultaneous division of the layer of chlorophyllous proto- 
plasm, which fills the outer part of the cell cavity. They exhibit the power of 
very active motion even before their exit from the cell, which occurs through a 
papilloid orifice, mostly at the end of the cell, sometimes in its side. Their cilia 
are sometimes two, sometimes four in number, and their life-history appears to be 
precisely similar to that of other zoospores. 


Cl. glomerata, (Ly.) 
Ramuli fili primarii in parte superiore atque ramorum ordinis secundi et tertii plerumque 
fasciculato- vel penicilliformi-aggregati. Cellula maxima vegete cytioplasmate cellularum 
parieti retiformi- vel subspiraliter applicato. Cellule fructiferee semper terminales, inferiores 


semper steriles videntur. (R.) 
Syn.—Cl. glomerata, (Kiitz1nc) Rasenuorst, Flora Europ. Algarum, Sect. III. p. 337. 
Hab.—Lake Ontario; Pickering. Falls of Niagara; Lakes Erie, Huron, and Michigan; 
Fourth Lake, near Madison, Wisconsin; Bailey. 


“Filaments tufted, bushy, somewhat rigid, much branched, bright grass-green; branches 
crowded, irregular, erecto-patent, repeatedly divided ; ultimate ramuli secund, subfasciculate ; 


articulations 4-8 times as long as broad.” 


188 FRESH-WATER ALG# OF THE UNITED STATES. 


Remarks.—Pyof. Harvey says (Smithsonian Contributions): “I have received 
North American specimens from Milton, Saratoga County, N. Y., and from Lake 
Erie; also from the Mexican Boundary Surveying Expedition.” 


Cl. fracta, Dittw. 

Clad. prima juventute affixa sed postea libere natans et cespites formans; ramis ramulisque 
sparsis, divaricatis, nonnunquam refractis; ramulorum cytioplasmate non spiraliter ordinato ; 
cytiodermate szepe crassissimo ; cellulis fertilibus haud terminalibus, plerumque in ramulorum 
medio, aut eorum basi. 


Syn.— Cl. fracta, (Dittw.) RABENHORST, Flora Europ. Algarum, Sect. IIL. p. 334. 


Hab.—In flumine Schuylkill, prope Philadelphia; Wood. West Point, New York; Provi- 
dence, Rhode Island; Bailey. 


In the young state fixed, but afterwards floating free and forming matted masses ; branches and 
branchlets scattered, divaricate, somewhat refracted ; cytioplasm of the branches not spirally 
arranged ; cytioderm often very thick; fertile cells not terminal, mostly in the middle of the 
branches, sometimes in their base. 


Cl. brachystelecha, Rasennorst. 

' Q. per totam vitam innata, obscure viridis, sicca pallida, pygmewa, 2-4, rarius 6 linea longa, 
ramosissima, intricata, plerumque culmigena; ramis primariis By” ay” = 0.00295" —0.0022" 
crassis, ramulis ultimis gy’"’— 7)” = 0.00147” — 0.00128” crassis; articulis diametro 4-12 
plo longioribus; cytiodermate subcrasso, hyalino, subtiliter plicato-striato ; cytioplasmate 
imprimis cellularum superiarum laxe spiraliter ordinato. (R.) 


Syn.—Cl. brachystelecha, RABENHORST, Flora Europ. Algarum, Sect. III. p. 343. 
Hab.—Prope Philadelphia; Wood. ; 


Fixed through the whole life, obscure green, pale when dried, dwarfish, 2-4, rarely 6 lines long, 
very much branched, intricate, mostly attached to culms; primary branches 0.00295" — 
0.0022” thick, ultimate ramuli 0.00147” — 0.00128” thick; articles 4-12 times longer than 
thick; cytioderm thickish, hyaline, subtilely plicately striate ; cytioplasm, especially of the 
upper cells, laxly spirally arranged. 


Remarks.—I have notes of having identified this species at some time, but, 
having kept neither specimens nor detailed memoranda, have simply copied the 
description of Prof. Rabenhorst. 


Famty OKDOGONIACEA. 


Alge monoice vel dioice. Fila articulata aut simplicia aut ramosa, cellula basali obovato-clavata, 
basi plerumque lobato-partitia vel scutata innata. Propagatio fit tum zoogonidiis tum oosporis 
fecundatione sexuali ortis. Zoogonidia formantur singula in quavis cellula, forma late ovali vel 
globosa, polo antico achroo corona ciliorum vibratoriorum predita. 

Oogonia singula vel plura (2-5) continua, plus minusve tumida, in quoque oospora singula, 
matura rubro- aut flavo-fusco-colorata, ante germinationem in zoosporas plerumque quatuor dilabens 
se format. : 

Antheridia brevi-filiformia, 1-2-3-10-articulata, plerumque singula aut oogonio aut filo vegeto in- 
sidentia aut in individuis variis sepe cellula obovato-clavata subtentata. 


Monecious or diecious algw. Filaments articulate, either simple or branched, fixed by the basal 
cell which is obovate-clavate, mostly with its base lobately parted or shield shaped. 
Propagation sometimes by zoospores, sometimes by resting spores, the result of sexual impregna- 
tion. Zoospores formed simply in certain cells, broadly oval or globose, their anterior end trans- 
parent, and furnished with a crown of vibratile cilia. Resting spores single or in series of from 


’ 


FRESH-WATER ALG# OF THE UNITED STATES. 189 


two to five, more or less tumid, single in each sporangium, at maturity reddish or yellowish fuscous, 
before germination dividing themselves into (mostly four) zoospores. 


Antheridia shortly filiform, 1-2-3-10 articulate, mostly single, either upon the sporangium or 
vegetation cell. 


Remarks.—The Cidogoniacee have been by previous writers simply divided into 
two genera, Gidogonium and Bulbochete. The plants represented by these two 
divisions have certainly many characters in common, as in the production of their 
zoospores and spermatozoids as well as in their peculiar method of cell division. 
Yet they are so very diverse in some particulars in regard to the latter, as well as 
in their habit of growth and in the formation of their sporangia, that it has 
seemed to me that the differences between them were more than sufficient to cha- 
racterize merely genera, and that to each of these groups should be awarded the 
rank of a sub-family. 

Again, in the old genus of Gidogonium, we have very distinct groups, separated 
by differences in the most important of all the characteristic portions of the plant— ~ 
the sexual apparatus. These groups are the so-called Monecious, Gynandrous, and 
Diecious Gidogonia; the monecious division comprising those plants in which one 
individual gives origin. both to the female and male germs; the gynundrous, those 
species in which the plant that produces the female germ gives origin also to a 
peculiar zoospore, the so-called androspore, which, after a period of motile life, 
settles down and develops a dwarf plant, the andreciwm, in which the spermato- 
zoids are developed ; and the diecious group containing species in which the male 
and female plants are distinct individuals, Dr. Pringsheim states (Morphologie der 
Cidogon., p. 43) that these groups pass into one another, but in my opinion, by his 
own showing, they are sharply distinct. The nearest approach to such passage is 
between the first and second groups, and consists simply in the fact that in certain 
species the androspore when it settles down develops into a one-celled instead of a 
two or three-celled antheridium. This to me does not seem to indicate a union of 
the groups, for the essential difference is not in the form or complexity of the an- 
theridium, but in the circumstance that in the one case the female filament develops 
a spermatozoid capable of fertilizing the germ, whilst in the other it gives rise to 
a body which does not possess that power at all, but does have the capability of 
giving origin to a second plant, in which the spermatozoid is developed. The 
groups, therefore, appear to be sharply and distinctly definable. 

In the Bulbochetie but a single genus has as yet been discovered, and this is 
distinctly gynandrous, but it seems probable that hereafter other plants of this 
subfamily will be found which are monecious or diecious, so that we will have 
in the two subfamilies two parallel groups of genera. 

For the reasons above indicated I have ventured to divide the family into two 
subfamilies, the one comprising three, the other a single genus. The peculiarities 
of growth, production of zoospores, and sexual development will be found described 


under the particular subfamilies. 


190 FRESH-WATER ALG#& OF THE UNITED STATES. 


SusraMILy GEDOGONIE. 


Filamenta stricta, haud ramosa, sine setis veris, sed sepe apice setiforma, elongata, hyalina. 


Filaments simple, not ramose, without true seta, but often with their apex seta-like, elongate, 
hyaline. \ 


Remarks.—The Gidogoniacee are small filamentous plants, whose size is sufficient 
to render them visible to the unaided eye, and yet not sufficient to make each indi- 
vidual distinctly apparent. They grow mostly in quiet water, attached to almost 
any and every thing that can afford a foothold, fringing with apparent indifference 
stones, twigs, sticks, dead leaves, bits of glass, boards, etc. I have seen such 
masses of them crowding the whole surface of a physa as to entirely conceal the 
animal and its shell, and present the curious spectacle of a perambulating, waving 
forest of bright green. ‘The individual filament is composed of cylindrical cells, 
which are always without a nucleus, and have their chlorophy! diffused instead of 
being collected into bands or stripes. The walls are mostly quite thick and 
marked near the distal end with circular strize, whose numbers bear relation to 
the edge of the cell, for these strie are the results of the peculiar method of cell 
multiplication by division, each one marking one such division. When an edo- 
gonium cell has attained sufficient maturity and is about to divide, the first per- 
ceptible change is the appearance of a little circular line or streak near its distal 
end. About the same time and in the same place a fine partition is formed by an 
outgrowth from the primordial utricle, a probably double delicate wall of con- 
densed protoplasm separating the upper end of the parent cell from the lower or 
main portion, The upper end now begins to develop into a new cell. This de- 
velopment takes place by the formation of an entirely new layer of celluloge 
inside the little cell, 7. e. between the new primordial utricle and the old cell all 
and afterwards by the lengthening of this layer by interstitial deposit in the usual 
way; the thick wall of the parent cell in no way directly participates in the 
growth (fig. 2 6, pl. 17). It is evident that as the new wall grows the old cell 
wall must be as it were raised up upon it, borne away as a little capping from the 
basal portion of the parent cell. Consequently when a young cell is watched 
during this process the little line-like incisure of the parent cell is seen to widen 
until it becomes an evident trench, and this trench grows wider and wider, until 
at last it is so broad as to be no longer a trench, and the little end of the parent 
cell simply caps its offspring. When the latter has fulfilled its allotted period ot 
growth, the process is repeated, the line of separation appearing this time just 
below the edge of the first cap. It is plain that the second new cell when formed 
must have a double cap crowning its extremity. At each repetition a new layer 
is added to the thickening cap, until at last it may be composed of six distinct 
layers, each projecting just beyond the next older one. Under the microscope the 
increased thickening of the distal end of a cell bearing such a crown-piecce is not 
sufficiently evident to at first attract attention, whilst each edge of a layer appears 
as a stria. Itis plain that the number of these striz represents the number of 


FRESH-WATER ALGA OF THE UNITED STATES. 191 


times division has occurred; if there be four strie, four times; six strie#, six 
times, &c. 

Besides this method of development, in many species new cells are formed by a 
sort of pullulation, occuring in the end cell of the filament. The primordial 
utricle appears to rupture the wall of the distal extremity of the latter and grow 
out into a little pullulation, or teat, which very soon becomes separated from the 
parent cell, by the reformation, as it were, of the end wall of the latter. The 
new little cell thus formed coats itself with cellulose, and rapidly grows, especially 
in length, always, however, or at least for a length of time, remaining of a smaller 
diameter than the cell from which it sprang. By a repetition of this process a 
succession of cells is formed, each one of which, like the successive joints of the 
field telescope, is a little smaller than its proximal neighbor and contains less 
chlorophyl, until finally the cells are reduced to exceedingly fine, perfectly trans- 
parent, colorless cylinders, which together form a seta or hair. 

Reproduction takes place among the Gidogoniacece, both by means of zoospores 
and sexual organs. The former of these are quite peculiar, and, therefore, require 
especial notice. 

Only a single one is ever produced in a cell, and there is.consequently no divi- 
sion of the chlorophyllous protoplasm preceding their formation. The first change 
noticeable is a sort of confusion of the cell contents, the protoplasmic portion of 
which loosens itself, as it were, from the walls, and collects in a mass at the 
distal end of the cell. This mass after a short time assumes a more or less irregu- 
larly globose shape, and simultaneously the parent cell begins to separate from its 
distal neighbor. This separation appears to take place commonly by a solution 
of an exceedingly fine ring of the wall of the parent-cell, just at the origin of the 
transverse partition separating the two cells, and it is therefore brought about not 
by a splitting of the end partition wall, but by a circumcision of the side walls of 
the cell, and consequently the cavity of the latter is thrown open, the end wall 
remaining with and closing the distal cell, whose contents have not undergone 
change. On the other hand, observation leads me to think that sometimes there is 
a splitting of the end wall. According to my observation, sometimes the filament 
is completely broken in two, but very commonly the two cells remain attached by one 
corner, opening from one another as it were on a hinge-joint (fig. 2 /, pl. 17). 

The gathering of the protoplasm, already spoken of, into a ball, is a slow process, 
and the escape of this ball, through the opening formed in the manner described, 
takes place even more slowly. ‘The motion is not at all perceptible, with a power 
of a thousand or twelve hundred diameters. During the passage the ball becomes 
more or less twisted and deformed, but as it emerges the uncompressed portion 
shortens and swells out, and when the mass of protoplasm is at last free in the 
water, it Soon assumes a globular or regularly ovate shape. The mother-cell, thus 
bereft of its contents, is left dead and void. The primordial utricle indeed still re- 
mains within, but it has lost all its wonderful powers, and is nothing but a shrunken, 
twisted, or folded dead membrane. What is the cause of the motion of the 
zoospore within the cell it is very difficult to determine. It certainly is not vibrating 
cilia. When the zoospore first escapes, it is, as already stated, an irregular lump 


192 FRESH-WATER ALG OF THE UNITED STATES. 


of strongly chlorophyllous protoplasm, homogeneous or with one or more roundish 
masses of darker green within it. As it assumes its shape, however, a very dis- 
tinct transparent spot appears at its smaller end. Whether this is an absolute 
vacuole or not, I have never been able to satisfy myself, but I am rather inclined 
to believe that it contains highly refractive transparent protoplasm. As this spot 
is perfected the cilia make their appearance. Whether they are actually first 
formed there, or whether, as is more probable, they are formed inside the cell, and 
are so folded against the general mass as to be invisible, I have never determined. 
Dr. Pringsheim, however, figures them within the cell. I have seen them in 
their early development long before motion commenced in them, but they were 
always perfectly formed as soon as apparent. ‘They are present in great numbers, 
making a crown or ring around the edge of the transparent beak-like end. When 
they commence to vibrate, their action is at first very slow, and the waves of 
motion run through them deliberately from one cilium to the other, but soon, 
however, the motile impulses succeed one another more and more rapidly, until 
the general mass of the zoospore begins to tremble, then to rock, and finally dart- 
ing off the little body hastens hither and thither through the water. The zoospore 
of an Gidogonium is always readily distinguished from most other similar bodies by 
its large size and peculiar motion, which is a forward movement combined with a 
distinct rolling on its long axis. After a time the zoospore, coming in contact 
with some speck of matter to which it can attach itself, ceases its movements, 
the cilia rapidly wither away, and the end to which they have been attached 
swells out or elongates into a broad, or narrow, simple, bifid, or trifid process, 
placed at an angle to the main axis of the cell, so as to form the so-called foot, the 
holdfast that anchors and fixes the new plant. Whilst this is taking place, the 
general form of the zoospore alters into that of a cylinder, a cellulose wall is 
secreted all about it, and the first cell of the new plant is complete. As soon as 
this cell is sufficiently matured, it begins to undergo division in the manner already 
described, and to develop into the new filament. 

In regard to the time when these zoospores are given off most abundantly, and 
the circumstances that influence the process, I can only state that it occurs when 
there is least tendency to the production of resting spores, probably in youngish 
plants, and I have thought was favored by a full supply of light, with a moderate 
temperature. 

Sexual reproduction occurs among the Cidogoniacew in accordance with three 
distinct types, to which the name of monecious, diecious, and gynandrous has 
been severally applied. The characteristic differences are to be looked for in the 
production of the antheridie or male plant, the female germ being always pre- 
“pared in essentially the same way. In most instances two cells are requisite for 
the production of the latter. At first there is nothing by which cells set apart for 
the formation of the female germ can be distinguished from ordinary cells. ‘The 
proximal one of the pair finally, however, undergoes changes similar to those 
seen when a zoospore is to be formed, namely, a sort of confusion of the endo- 
chrome, and finally a gathering of it into a mass at the distal end of the cell. In- 
stead of there being a solution of the side wall of the cell, however, the end wall 


FRESH-WATER ALGA OF THE UNITED STATES. 193 


undergoes absorption, so that the cavities of the two cells are more or less com- 
pletely thrown into one. All or nearly all of the contents of the proximal cell 
now slowly pass into the distal one, which thus becomes crowded with chloro- 
phyllous protoplasm. At or before this period, the distal receiving cell undergoes 
a change in form, widening out greatly, and sometimes appearing actually to 
shorten, so that it is in most instances resolved into a more or less regular globose 
or oval cell, As the sporangium or spore-case thus formed perfects itself the endo- 
chromes of the two cells become completely fused into one mass, which gradually 
condenses and assumes a regular shape, until, in the form of the perfected female 
or receptive germ, it is a dark, opaque ball more or less completely filling the spo- 
rangial cell. At the same time, in order to afford passage for the male germ, an 
opening is formed through the walls of the sporangium. This happens in two ways. 
The simplest of these is by the formation of one or more circular openings or 
pores in the wall. This pore is sometimes below, sometimes above the equatorial line. 
Its position, numbers, and form afford good specific characters. The second method 
is by the development of a little trap-door entrance at the distal end of the spore- 
case. This method is unknown in our American flora, and, never having seen it, 
I must refer to the papers of Pringsheim for details. 

The above-described mode of origin of the sporangium is the common one. In 
O. mirabile, Woop, however, but one cell is concerned. This cell grows to an 
enormous size, far beyond that of its fellows, and its endochrome collects into the 
upper half of it, to be at last shut off from the lower half of the cell by the. forma- 
tion of a new cellulose partition or end wall; or, in other words, the parent cell 
divides by a modified process of cell division, different from that common in the 
family. The distal daughter-cell contains all the endochrome. After the changes 
are completed, the appearance is the same as ordinarily presented, namely, an empty 
cell surmounted by the sporangium. Sometimes, even in plants in which the ordi- 
nary process occurs elsewhere, a single cell appears at times to have sufficient 
vitality to develop into a sporangium without aid from its neighbor, so that the 
latter will preserve its integrity, and the resting spore finally lie in proximity to a 
cell full of endochrome. 

In the monecious Cfdogoniacee, a single filament produces both the male and 
female germs. Certain cells appear to be set apart to develop into sporangia, whilst 
others give origin to the spermatozoids. No such plants have as yet been detected 
in North America, and I, therefore, pass on without speaking more in detail. 

The second method in which the spermatozoids are produced is the most com- 
mon in our flora; it is the so-called gynandrous plan. In this the single filament 
produces the female germs directly and the male germs indirectly. The former 
arise in the way previously described, whilst the latter are the ‘resultant of a 
complex series of life actions, as follows: One of the main cells of the originating 
filament, differing in no perceptible way from its fellows, instead of like them 
developing new cells, divides up by a simple process of cell division into two or 
more cells, each one of which contains very largely of chlorophyllous protoplasm. The 
protoplasm within each of these secondary or daughter-cells soon condenses into an 


irregularly ovate or conical mass, which often, even within the cell, may: be seen to 
25 September, 1872. 


194 FRESH-WATER ALG OF THE UNITED STATES. 


have the transparent beak of the zoospore (pl. 18, fig. 2d). Inside of the cell 
the androspore, as it is called, shows no cilia, but when it is set free by a more or 
less complete solution of the cell wall, it assumes the form of the ordinary Cidogo- 
nium zoospore, with a crown of cilia, whose vibrations soon cause it to dart through 
the water. These androspores are of course much smaller than an ordinary 
zoospore, and after a period of active motion, they attach themselves to the parent 
filament, generally either on or near the sporangial cell. ‘Their first life-actions, 
after settling, are precisely like those of the zoospore, namely, dropping of the 
cilia, enlargement of the smaller end into the so-called “ foot,” an elongation of 
the general mass, and the secretion of an outer coating of cellulose. In this way 
a peculiar-shaped, somewhat ovate cell is formed, which contains a great quantity 
of rich protoplasm with mostly a small amount of chlorophyl. From such cells are 
developed the mostly two- or three-celled, perfect antheridia, which in gynandrous 
Gidogonia are generally to be seen, during the period of fructification, in numbers 
attached to the filament, mostly in the neighborhood of the sporangium. Their pro- 
toplasmic contents are remarkable for the activity of their movements, and I have 
seldom seen more beautiful and rapid cyclosis than they display—currents setting in 
all directions—particles actually brushing against one another (pl. 17, fig. 2). 
The spermatozoids are formed in the distal cell, sometimes one, sometimes more. 
In the species O. mirabile, Woon, (pl. 18, fig. 2 g, 2 6) in which I have most 
carefully studied their origin, two are produced in the single cell. This cell is in 
the commencement of the process, although comparatively poor in chlorophyl, 
crowded with a rich solid protoplasm, which divides into two distinct masses, some- 
what in the manner seen in the commencement of ordinary cell division. As 
there is no distinct nucleus, of course there are no precedent nuclear changes, 
The masses thus formed gradually assume a more or less perfectly globular shape 
inside the cell, although I have never been able to see that they there develop cilia, 
and finally are set free by the lifting up of the end of the mother-cell, like a little 
trap-door. Their mode of escape through the exit thus offered is similar to that 
of the ordinary zoospore, which they resemble, except that they are much smaller, 
are much less rich in chlorophyl, and have the anterior clear space less defined. 
They are said to be furnished with a crown of cilia similar to that of the zoospore, 
I myself have never seen these, but do not doubt their existence. 

In the diecious Cidogonia there are distinct filaments, male and female, one of 
which produces the oosporangium with its contained germ, whilst the other gives 
rise directly to the spermatozoids. 

‘The resting spore which develops after impregnation is variously shaped, but in 
most instances is round or oval. It is often, if not always, furnished with two coats, 
the outer of which is thick, firm, and frequently provided with surface appendages, 
such as tubercles, ridges, spines, etc. Besides these there is also, probably, a very 
delicate inner coat. The spore appears to be set free from its case by the decay of the 
latter, there being never, at least that I have seen, any regular dehiscence. Although 
I have made several attempts, it has never been my good fortune to observe anything 
like germination of these resting spores. Prof. Chr. Vaupell, however, has published 
an account of the manner as observed by himself. Some water containing fruitful 


FRESH-WATER ALGA OF THE UNITED STATES. 195 


Cidogonia was allowed to dry in a glass, towards the close of September, and the 
greenish residue was placed in water in the following January. By March the 
resting spores were everywhere in active germination. The first change was a 
rupture of the two outer coats and the escape, through the slit, of the contents, 
still surrounded by a very delicate hyaline membrane. By this time the proto- 
plasm had divided into usually four (sometimes only two or three) greenish masses, 
each of which was oval in shape and had its own extremely thin, hyaline coat, 
and was therefore a perfect cell. The old outer shell of the spore laid discarded 
in the water and soon decayed, and in a little while the hyaline sac surrounding 
the four daughter-cells itself disappeared, leaving them exposed and naked. After 
awhile each of these cells opened at one end by means of an annular split, cutting 
off the apex of the wall and allowing it to lift off like a little lid. Through the 
circular opening thus made, the contents now emerged. The point of the inner 
mass was colorless and directed towards the orifice, and the whole moved vigorously 
backwards and forwards until it finally escaped, as a perfected zoospore. ‘This 
little body simulated very closely the ordinary zoospore, both in appearance and 
life-history, growing, after a brief period of activity, into an ordinary filament, in 
precisely the same manner as the zoospores. 


Genus GADOGONIUM. 


Antheridia et oogonidia in individuo unico. 


Antheridia and oogonidia in the same individual. 


Remark.—No species of ‘the genus Gidogonium, as here defined, has as yet 
been discovered in this country. 


Genus PRINGSHEIMIA. 


Dioica. Antheridia et oogonidia in individuis distinctis orta. 
Dicecious Antheridia and oogonidia arising in distinct individuals. 


P. inequalis, Woop. 
P dioica; cellula basali biloba; plantis femineis quam plantis masculis permulto majoribus; 
oogoniis enormiter globosis vel subovoideis, poro laterale supra medium posito instructis; 
oosporis forma eadem, sed paulo minoribus. 


Syn.—Cidogontum inequale, Woon, Proc. Amer. Philos. Soc., 1869, p. 141 
Hab.—In stagnis, prope Philadelphia. 


O. dicecious, basa] cell bilobate; female plant very much larger than the male plant; oospo- 
rangium irregularly globose or subovoidal, opening by a lateral pore above the middle; 
resting spores of the same form as the sporangium, but a little smaller. 


Remarks.—This plant seems to be more closely allied to O. gemelliparum, 
Pringsheim, than to any other species. It agrees with it in the inequality of the 
male and female plants, in the shape of the sporangium, and the position of the 
lateral pore. The diameter of the female plant is often nearly four times that of 
the male, and the difference in length is much more apparent. The mother-plant is 
composed of from 3-6 cells in the most distal of which the spermatozoids are formed. 
I am not able to state how many of these bodies are formed in a single cell, having 


196 FRESH-WATER ALG& OF THE UNITED STATES. 


only seen the latter when more or less completely emptied, but, judging from the 
relative sizes, there must be several. In acell containing a single spermatozoid, that 
body moved about freely, and at last escaped, apparently through an orifice in the 
end wall of the cell, It made two attempts before getting out, and during its 
passage was distinctly constricted in the middle. It resembled in appearance an 
ordinary zoospore, but was of course much smaller, and was nearly devoid of color, 
having but a slight greenish tint. I found this species growing abundantly in the 
stagnant ditches of the Neck, below the city. . 

Fig. 1 a, pl. 18, represents a young female plant; 18, a fertile plant with imma- 
ture spores. 1c was taken from the supposed male plant alluded to in the text. 
The latter figure is magnified 450 diameters, the others 250. 


Genus ANDROGYNIA. 


Gynandra. Androspore in plantis femineis orte ; postea hanc affixe et in antheridiis se formant. 


Gynandrous. Androspores arising in the female plant; after affixing themselves to this and 
developing into antheridia. 


A. multispora, Woop. 
A. oogoniis singulis, vel binis vel ternis continuis, globosis instructa; poro laterale distale; 
oosporis globosis, oogonii lumen replentibus ; antheridiis plerumque pluribus, planta feminea 
insidentibus, cellula inferiore multo majoribus. 


Syn.—Oedogonium multispora, Woop, Proc. Amer. Philos. Soc., 1869, p. 141. 
Hab.—In stagnis, prope Philadelphia. 


.Oosporangia single or bi- or triseriate, globose with a distal lateral pore; oospore globose, 
about the same size as the sporangial cavity; antheridia bi- or tricellular, curved, with the 
lower cell much the largest, generally adhering in considerable numbers to all parts of the 
female plant. 


Remarks.—This species differs from its nearest European congeners, Gidogon. 
Rothii and Gi. depressum, very markedly in the bicellular antheridia. I have never 
seen the spermatozoids actually emerging from their mother-cell, but have seen in 
the terminal antheridial cell a pair of oval bodies, which I took to be those bodies. 

Fig. 3, pl. 17, was taken from a filament of this species magnified 500 diameters. 
It shows spores in different stages of maturity, with an empty basal cell in one 
case, and in the others without. Also male plants, one of them containing partially 
formed spermatozoids. The small arrows indicate the direction of cyclotic 
currents. 


A. mirabilis, Woop. 

A, rare setigera; articulis diametro 2-8 plo longioribus ; oogoniis plerumque singulis, rare 
geminis, nonnihil ovatis, infra latis sed supra contractis et medio tumidis; poris lateralibus 
duobus supra medium positis ; oosporis aut late ovalibus aut subglobosis ; sporodermate haud 
signato; antheridiis plerumque bicellularibus, interdum tricellularibus, plerumque in filo 
vegetativo infra oogonium aut in oogonio insidentibus; spermatozoideis singulis et geminis, 

Diam.—Artic. veget Te00 —7hio” =-0004”—0017". Spor. reba —7 28". 0024"—0027". 

Syn.— Gidogonium mirabile, Woop, Proc. Amer, Philos. Soc., 1869, p. 142. 


Hab.—In rivulis quietis, prope Philadelphia, 


FRESH-WATER ALG#® OF THE UNITED STATES. 197 


A. rarely setigerous; articles 2-8 times longer than broad ; oosporangia mostly single, rarely 
geminate, subovate, in the lower portion broad, in the middle swollen, in the upper part con- 
tracted; the 2 lateral pores situated above the middle; oospore subglobose or broadly 
ovate, its coats without markings; antheridia generally bicellular, sometimes tricellular, 
numerous, placed generally upon the female filament either upon or below the oosporangia. 


Remarks.—This species was found growing in a rather stagnant brook in the 


meadow by “‘Robinson’s Knoll,” at the junction of the Schuylkill River and Wissa- 
hickon Creek, near Philadelphia. The filaments, which vary very greatly in size, 
are in their early history attached to dead leaves and sticks, but finally, I think, 
float free in the water. The larger, fruit-bearing filaments are remarkable for their 
crookedness. None of the threads that I have seen ended in a seta-like portion. 
The fruit is produced in abundance, but very rarely is there more than a single 
spore in any one place. ‘The method of the formation of the sporangia differs from 
that of all-the other Gidogonia which have come under my notice. Instead of 
two cells being concerned but one cell is employed. The cell (fig. 2 a, pl. 18) that 
is to be used for such a purpose grows much beyond the ordinary size, until it is 
nearly or quite twice as large as its neighbors. All the time it is well filled with 
chlorophyllous protoplasm. This now contracts and finally is all packed into the 
upper half of the cell. At or even before this time the lateral openings become appa- 
rent. There are two of them, situated just in the angle where the cell at its upper 
end commences to contract to the size of its fellow. At this time I think fertiliza- 
tion takes place, although I have never actually seen the spermatozoids enter the 
orifices. The cell (fig. 2 6, pl. 17) now divides into two by forming a wall separa- 
ting the lower empty half from the upper full one, which is to be the sporangium. 
The contents of the latter now condense into a ball, and it itself becomes more tumid 
in the middle. Finally a reddish-brown broadly globular spore (fig. 2 ¢, pl. 18) 
is formed. I have not been able to make out more than one distinct thick coat. 
The surface of the-spore is smooth. The androspores are formed in a cell (fig. 
2d, pl. 18) which has grown beyond the normal size and then divided into four 
or five short cells, each of which gives origin, I believe, to a single androspore 
inits interior. The antheridia are numerous, from 2 to 6 being commonly attached 
to the lower portion of the sporangium, or to the cells just beneath it. They 
(fig. 2 e, pl. 18) have a rather large foot, and are generally curved at the base. The 
distal of the two cells composing them is crowned with a little cap, and produces 
one or sometimes two spermatozoids. These (figs. 2 6 and 2 g, pl. 18) during their 
escape are always very much squeezed out of shape, but when free become globular 
or slightly pear-shaped. They are highly transparent and contain a few green 
granules. Their motion is at first slow, but soon becomes very active. The mode 
of egress from the cell is obtained by the cutting off of the upper end of it, the 
little cap opening like a trap-door. After this cell has been emptied, sometimes a 
second similar one is formed, which bears it aloft. I have never seen spermato- 


zoids produced by this second cell. 
A. Huntii, Woop. 


Filuma plerumque in setam longam, bet nj 
umque singulis, globosis, interdum nonnihil hexagoniis, medio nonnihil tumidis, 


terminalem coloris expertam productum ; oogoniis pler- 
poro laterale 


198 FRESH-WATER ALG OF THE UNITED STATES. 


infra medium posito; oosporis globosis, oogonii lumen haud replentibus, superficie lineis 
elevatis spiralibus quatuor instructa; antheridiis bicellularibus (interdum tricellularibus ?). 


Diam.—Spor. zhy”=.002”. 
Syn.—Cidogonium Huntii, Woop, American Naturalist, 1868. 
Hab.—In aquario meo. 


Filaments mostly produced into a long apical seta; oogonia mostly single, globose, sometimes 
somewhat, hexagonal, somewhat tumid in the middle, the lateral pore placed below the 
middle; oospore globose, not filling the cavity of the spore case, its surface with four spiral 
elevated lines or ridges; antheridia bicellular (sometimes tricellular 7). 


Remarks.—This little plant appeared in my aquarium some years since, forming 
a delicate fringe upon the various aquatic plants growing therein. Its color is a 
bright yellowish green, deepening to a very dark green in cells which are crowded 
with granular protoplasm. ‘The filaments vary very greatly in size, the largest I 
have seen were 54, of an inch in diameter. They are provided with long, termi- 
nal seta, which are much more universally present than in any of the other species 
I have met with. ‘The first step in the formation of a spore is the emptying of a 
cell into its distal neighbor, so that each spore case is placed at the end of an empty 
cell. These sporangia may be single or they may be in series of two or more, 
separated only from one another by the eruptive cells just spoken of. The color 
of the mature spore is a very dark reddish-brown. The antheridia is bicellular, 
slightly curved, somewhat stipate, with a distinct foot. Its most common position 
is on the vacated cell just below the spore case. The zoospores, as I have seen 
them, are always globose. 

I have named this species after my friend, Dr. J. Gibbons Hunt, a well-known 
microscopist of this city, to whom I am greatly indebted for aid in my earlier 
microscopic studies. 

Fig. 2, pl. 17, represents different forms and parts of this plant. 2 a shows 
the end of a filament and the long seta-like lip. 2b was taken from two cells, 
one of which had just undergone division, and shows very plainly the method of 
procedure; lying as it were between the cells, and bearing the end of the lower 
one upon it, is the new little cell. Fig. 2¢ represents a fertile filament with two 
mature spores and one not fully grown. Fig. 2d was drawn from a filament just 
forming a spore, and shows the male plant in situ. Fig. 2 e represents a male 
plant (magnified some 1300 diameters) with the outer terminal cell scarcely more 
than a primordial utricle. The contents of the lower cell were in a state of in- 
tense motion; and the arrows are meant to indicate the directions of the currents. 
Fig. 2 f represents a portion of a filament with a zoospore just escaped and still 
quiescent. 


A. echinata, Woop (sp. nov.) 
A. valde elongata; articulis diametro 6-14 plo longioribus; oogoniis globosis, plerumque de- 
pressis, ad .0014” crassis; oosporis oogonii forma et ejus lumen replentibus, valde aculeatis ; 
poro laterale supra medium posito; antheridiis bicellularibus ? 


Diam.—Spor. oso = .001”. Cell. 3000 — soso = .00033” — .0005”. 


Hab.—In stagnis, Alleghany Mountains, 


FRESH-WATER ALG# OF THE UNITED STATES. 199 


O. gynandrous, very elongate ; joints 6-14 times longer than broad ; sporangia globose, mostly 
depressed, about .0014” in diameter; oospores of the same form as sporangia, whose cavity 
they almost fill; covered with sharp spines; the lateral pore placed above the middle; an- 
theridia bicellular ? 


Remarks.—I found this distinct species in a little stagnant pool in the 
wilderness, known as Bear Meadows, in Centre County, of this State. ‘The fila- 
ments are very long, and were matted together into a sort of fibrous mass. The 
male plants were few in number, and were attached to the female plant in the 
neighborhood of the sporangia. I have not seen any composed of more than two 
cells, They are furnished with a well-marked foot, above which there is a short 
neck, As I have seen them they are nearly straight. 

I have not been able to make out more than one coat to the spores. This coat 
is very thick, and is furnished with numerous thorn-like spines. These are very 
sharp at the points, but at their bases are mostly very robust. 

Fig. 3, pl. 18, represents a spore of this plant magnified 750 diameters. 


SupramMity BULBOCH ATE. 


Filuma ramosum, setis strictis hyalinis achrois e basi bulbosa et plus minus elongatis instructum. 
Filaments branching, furnished with straight, hyaline, more or less elongated seta, arising from a 
bulbous base. 


Remarks.—The Bulbochetee are at once separated from their allies the Gidogo- 
miee by their bushy, branched habit of growth. The shape of the individual 
cell is also entirely different, for instead of being regularly cylindrical they are 
almost always markedly dilated at their distal end, so as to be somewhat clavate, 
nor is the filament or its branches ever ended by a long seta-like series of narrow 
colorless cells. Many or all of the cells are, however, furnished with a single 
very long unicellular unbranched hair. These hairs are colorless, hyaline, and 
provided with a markedly and abruptly bulbous base. The Bulbochetee grow in 
similar positions to their allies, but are not nearly so common, nor when present 
do they grow in such abundance, very rarely, if ever, forming the dense forest-like 
fringes or the matted masses that some species of the Gidogoniee do. They are 
reproduced both by zoospores and resting spores. 

The manner of the development of and growth of the plant from the zoospore 
is very peculiar. I have never myself studied it, but Prof. Pringsheim gives the 
following account: When the zoospore first settles down it produces a cell closely 
resembling that of an Gidogonium. ‘The first change which occurs in this cell is 
the formation of a small, conical, transparent, colorless space at the apex, which 
space in a little while becomes separated from the mother-cell by a distinct par- 
tition-wall, and at the same time the apex itself is ruptured, and the point of the 
little growing cone pushed through the opening. This rupture does not take 
place irregularly, but by a sort of circumscribed dertiscence, similar to that of the 
Cidogonium, the top of the mother-cell being lifted up like a little trap-door, and 
finally pushed aside as the new conical cell grows elongate and becomes converted 
into a hair. After the formation of this apical hair, the mother-cell undergoes 
division in a manner similar to that of an Gidogoniwm. Near its distal end a 


200 FRESH-WATER ALGA OF THE UNITED STATES. 


circular slit appears, and at the same time a partition forms, so that from the 
mother-cell are developed a small apical and a large basal daughter-cell. ‘The his- 
tory of the former of these is simply one of growth as regards the main axis, It 
increases in size but does not give origin to new cells. All such cells are formed 
out of the basal daughter-cell, which, as already described, divides into a new 
apical and basal cell—the apical only to grow in the main filament—the basal to 
divide anew. It is always the basal cell that undergoes division, throughout the 
whole life-history of the plant, one cell alone contributing to the growth of the 
main filament. The filament thus formed bears upon its distal end the hair which 
grew upon the original spore-cell, and this hair is, save only the basal cell, the 
oldest part of the filament. The cell upon which it rests is the next oldest, the 
next to it in position, the next in age, and so on (from older to younger) down to 
the basal cell, the oldest of all, lying next to the latest born. 

Although the cells of the main filaments do not contribute to its development, 
yet it is from them that the lateral branches are formed. The production of a 
branch begins by the appearance of a clear space near the apex of the cell, but this 
clear space is placed, not exactly at the apex, but a little to one side. It soon becomes 
distinctly conical, enlarges, bursts through the old cell-wall, is cut off by a cellulose 
partition from its parent, and develops into a hair similar to that first formed, but 
placed at an angle to the long axis. It is remarkable that the opening for the 
exit of the growing hair occurs, not by a circular transverse slit, but by a longi- 
tudinal one, the two halves of the old cell-walls separating as the little cone pushes 
its way between them and persisting as a sort of sheath to its base. When the 
hair is perfected the cell from which it grew undergoes division in the usual way, 
save only that the cutting off of the old wall is done obliquely instead of trans- 
versely, so that the partition is oblique instead of horizontal, and the new cell 
grows at an angle to the old, instead of in the line of its axis. The new cell, 
consequently, is the starting point to a branch at an angle to the main filament. 
This branch, like the main filament, grows only by the repeated divisions of its 
primal basal cell, and bears aloft its seta. Secondary branches may arise from it 
precisely in the way that it arose from the parent stem, and thus at last is formed 
the bushy plant of the Bulbochetee. 

The zoospores closely resemble those of the Gidogoniee, and are oval or glo- 
bose masses of chlorophyllous protoplasm, with a transparent space at the smaller 
end, surmounted by a crown of cilia. Their mode of formation and whole life- 
history are also similar to that of the’ Gidogoniece zoospores, up to the time when 
in their germination they begin to produce new cells. 

Sexual reproduction amongst all the known Bulbochetee is similar in its general 
aspect to that seen among the gynandrous Cidogoniee, but differs considerably in 
detail. The oogonia are mostly formed in lateral branches. Their position in these 
branches varies in the various species, : 

Since any cell from the next to basal to the most distal of all. crowned: with the 
terminal seta may be converted into a oogonium, according to Pringsheim, the 
cell which is to form the oogonium arises in the usual way, by the division of a 
cell into two daughter-cells. The new daughter-cell, which is to develop into the 


FRESH-WATER ALG# OF THE UNITED STATES. 201 


sexual part, does not, however, rupture the old wall of the mother-cell, but grows 
out beyond it, and there dilates. ‘The new cell is therefore divisible into two parts, 
a proximal cylindrical portion, contained within the walls of the mother-cell, and 
a distal more or less globular piece beyond the latter. The chlorophyllous proto- 
plasm now collects in this dilated portion, leaving the basal cylindrical part bare and 
empty. The oogonium is not, however, formed directly from this upper portion 
(the primitive oogonium, as it may be called), but a new wall forms within the latter 
and then it undergoes division much as did the primary cell. In this way it is that 
the upper and lower portions of the old wall, 7. e. that of the primitive oogonium, 
remain as a sort of basal sheath and cap to the fully-formed sporangium. The 
little hole by which the spermatozoids find entrance to the contents of the oogo- 
nium is always formed in the upper half of the wall of the latter. 

As stated, all the species of Bulbochetew as yet known are gynandrous. The 
antheridia resemble those of similar Gidogoniee, and their life-history is very similar. 
The development of the resting spores is said to take place as follows: The first 
change is in the color of the spore, the bright red becoming green, especially near 
the margins of the cavity. The outer wall is then ruptured and the spore grows 
into a long oval body, whose contents are chiefly green with a sprinkling of the 
original red. The protoplasm of this oval body gradually divides into four masses, 
which become more and more distinct, until they are at last well formed zoospores, 
similar to those produced in the more ordinary method, except, perhaps, that they 
are redder. They are finally set free in the water by a solution of the cell wall 
surrounding them, and enter upon a brief free existence, to settle down after a 
little and grow into a fully-formed plant. 


Genus BULBOCHLATE. 


Androspore in planta feminea ort, postea hance affix et.in antheridiis se formantes. 


Androspore arising in the female plant, afterwards affixed to it and developing into the antheridia, 


B. ignota, Woop. 

B. sparse ramosa, elongata; articulis diametro max. (xsoy’ = -00077") 13-83 plo longioribus; 
oogoniis long. gh4” = .0025”, lat. gi45” = -0018", interdum lateralibus et sessilibus, inter- 
dum inter ramulorum cellulas vegetativas positis, dissepimento nullo; oosporis ovalibus, longi- 
tudinaliter nonnihil oblique ct distante costatis, in etate provecta aurantiaco-brunneis, sporo- - 
dermate crasso; antheridiis 3-4 cellularibus, stipitatis. 


Syn.—B. ignota, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869. 

Hab.—In aquis quietis, prope Philadelphia. ; 

B. sparsely branched, elongate with the joints 13-3 times longer than broad (y3/gy” = .00077"); 
oosporangia .0025” long by .0018” broad, sometimes lateral and sessile, sometimes placed 
upon the apex of a branch, sometimes situated in the length of the branches between their 
cells; the empty cell which supports the sporangium without dissepiment; oospores, oval, 
filling rather closely the cavity of the spore-case, longitudinally somewhat obliquely and dis- 
tantly costate, when mature orange brown; spore-coat rather thick; antheridia 3-4 celled, 
scarcely stipitate. 


Remarks.— When I described and figured this species J had never scen the 


mature fruit, but very recently Mr. Quimby has communicated specimens to me. 
26 September, 1872. 


202 FRESH-WATER ALG& OF THE UNITED STATES. 


The color of the spore is orange brown, and the thick coat is slightly tinged with 
yellowish. The mature oosporangium is somewhat flattened at the sides, not so 
elliptical as the young spore, which I have figured. 

Fig. 5 a, pl. 18, represents a fragment of a filament showing young sporangial 
cells magnified 260 diameters; 5 b, represents a branch with a youngish spore in it, 
magnified 460 diameters; fig. 5c, was taken from a male plant. 


B. dumosa, Woop. a 
B. articulis diametro 14-2 plo longioribus; oogoniis plerumque in ramorum brevissimorum 
apicibus positis sed interdum lateralibus, plerumque setam terminalem gerentibus; oosporis 
enormiter ovalibus aut ovatis, nonnihil indistincte longitudinaliter oblique subarcte. striatis ; 
antheridiis bicellularibus, stipite instructis, cellula basale medio tumida, supra saepe contracta. 


Syn.—B. dumosa, Woop, Prodromus, Proc. Amer. Philos. Soc., 1869, p. 142. 
Hab.—In aquario meo. 


Joints 14-2 times longer than broad; oosporangia generally placed upon the ends of short 
branches but sometimes lateral, mostly carrying a terminal seta; resting spores irregularly 
oval or ovate, somewhat indistinctly obliquely longitudinally and rather closely striate; an- 
theridia bicellular, furnished with a little stipe, their basal cell tumid in the middle, frequently 
contracted above. 


Remarks.—This species appeared spontaneously during the latter part of the 
winter upon some large fresh-water alge which I was cultivating. It branches 
irregularly and sometimes somewhat profusely, so as to have quite a bushy habit. 
‘The antheridia appear to produce a single spermatozoon in the terminal cell; at 
least as far as my observation has gone this is true. I think I have always found 
the distal cells of fertile plants emptied of their contents, as though they had fur- 
nished the androspores which had grown into the antheridia. This species is 
closely allied to B. gracilis, of Pringsheim, from which it differs in the position of 
the oogonia, in the relative breadth and length of the cell, and the number of cells 
composing the antheridia.. 

Fig. 6 a, pl. 18, represents a filament of this species magnified 260 diameters; 
6 b, a male plant magnified 750 diameters. 


B. Canbyii, Woop. 

B. permagna ad .035” longa, sparse ramosa; articulis sterilibus diametro 2-8 plo longioribus: 
oogoniis lateralibus vel in ramulorum apicem positis, transverse enormiter ovalibus; oosporis, 
transverse enormiter ovalibus, plerumque nonnihil triangularibus, oogonii lumen replentibus; 

* sporodermate crasso, haud costato, enormiter punctato; antheridiis bicellularibus. 


Diam.—Cell. steril. roo" —eFo0" = .00066—001. Spor. transv. 7345" = .00226. 

Syn.—B. Canbyii, Woon, Proc. Amer. Philos. Society, 1869, p. 142. 

Hab.—In aquis quietis, prope Hibernia, Florida; (WIliam Canby). 

B. very large, attaining a length of more than one-third an inch, sparsely branched ; sterile 
joints 2 to 8 times longer than broad ; oosporangia lateral or placed upon the ends of branches, 
irregularly transversely oval; oospores of a similar shape, often a little triangular, filling the 
cavity of the sporangium; spore coat thick, not costate but irregularly punctate. 


Remarks.—It affords me great pleasure to dedicate this very handsome species 
to Mr. William Canby, by whom it was collected in Florida, as an acknowledg- 
ment of favors received, and as a testimony of respect and high regard for him 


FRESH-WATER ALG OF THE UNITED STATES. 203 


personally, and as being among the foremost students of American phanerogamic 
botany. 

This’ species is more nearly allied to S. minor than to any other of the European 
forms, but differs from it very essentially in size and habit. It is always, as I have 
seen it, except in very young plants, sparsely and mostly dichotomously branched, 
and attains a very great length, at times probably exceeding the third of an inch. 
The spore is mostly sessile upon the distal ends of the cells of the filament; in all 
such cases I have noticed that the cell upon which it was borne was divided in its 
middle by a partition into two cells. Not unfrequently the spore is raised upon a 
short branch. ‘The male plants are attached to the female filaments generally in 
the neighborhood of the sporangium, to which they sometimes fasten themselves 
immediately. ‘They are shortly stipitate, and composed of two cells. The mature 
spore is transversely oval, now and then slightly triangular, and is nearly of the 
color of burnt sienna. Its coat is thick, often slightly yellowish, and has on its 
outer surface irregular punctations, looking like corrosions. ‘These are not detach- 
able, except when the ruptured spore is more or less completely emptied of its 
contents. The sporangium closely invests the spore, and when the latter is matured 
undergoes a circular division, so that the top falls off and allows the spore to escape. 

Fig. 6 ¢, pl. 16, represents a portion of a filament, magnified 260 diameters, 
with a young sporangium and young male plants attacned; 6 b, represents a very 
young plant, magnified 260 diameters. Fig. 6 a, was taken from a mature plant, 
and shows the mature spore. Fig. 6 e, shows in outline a sporangium and male 
plants attached; whilst 6d, was drawn from a sporangium which had perfected 
its spore and undergone the natural dehiscence. 


Famity CHROOLEPIDEA. 


Alge aerex, aureo-, aurantiaco- vel rubro-fusco-colorate, siccate spe cane. Fila varie ramosa, 
cytiodermate crasso vel subcrasso, firmo, subcartilagineo preedita, in pulvinulos minutos vel in stra- 
tum tenue aut incrassato-tomentosum densissime aggregata vel implicata. Cytioplasma oleosum vel 
granulosum, aut rubellum, aureum, aut flavo-fuscum, interdum viride tinctum, post mortem plerum- 
que expallescens. Propagatio fit zoogonidiis. 


Mrial alge. Golden orange, or reddish fuscous, often grayish when dried. Filaments variously 
branched, furnished with a thick, or thickish, subcartilaginous cytioderm, densely aggregated into 
minute cushions, or a thin or tomentosely thickened stratum. Cytioplasm granular or containing 
oily particles, reddish-golden, or yellowish-fuscous, sometimes tinged with green; after death often 
colorless or nearly so. Propagation by zoospores. 


Remarks.—The plants of this family are so different from the others of the 
order, that it is a matter of considerable doubt whether or not they should be 
classified with them. They rarely possess distinct, well-pronounced chlorophyl, 
and form mats or strata of some shade of reddish, grayish, or brownish, so that 
they are very different in appearance from the other Confervacee. 

I do not think their position can be certainly fixed until their life-history has 
been more fully developed. In assigning them this place I have simply followed 
Prof. Rabenhorst. 


204 FRESH-WATER ALGA&A OF THE UNITED STATES. 


The only specimens that have come to my notice are in a dried condition, and 
consequently no possible opportunity has been afforded of studying the manner of 
reproduction. No one has as yet, at least to my knowledge, discovered any “sexual 
reproduction in the family, but the method in which the zoospores are produced 
has been carefully studied, especially by Drs. Caspary (Regensburg Flora, 1858) 
and Hildebrand (Botanische Zeitung). The little motile bodies are not produced 
in the cells indiscriminately, but in certain ones set apart for the purpose, to which 
the name of zoosporangia is very applicable. These are large, globular, thick walled 
cells, which are generally provided with a protuberance at the top and marked by 
transverse wrinkles. They are most frequently situated upon the end of the filament 
or one of its branches, but are rarely placed in the middle of the thread, and still 
more rarely the cell next below the zoosporangium elongates itself sideways and up- 
wards into a thread, so that the reproductive cell is left as a lateral one-celled branch 
or process. When the zoosporangium is sufficiently matured the endochrome 
breaks up into a number of minute masses, the future zoospores. Finally the 
crowning papilla of the mother-cell ruptures and allows the contents to escape as 
a well-formed vesicle, containing the perfected zoospores. It is said, however, that 
sometimes the vesicle is wanting, and the zoospores are discharged into the water. 
In the ordinary course, after a little while the vesicle lying in the water bursts 
and sets its motile contents free. ‘The ae a themselves are very small, accord- 
ing to Hildebrand, ,3,—;$,;mm. in length, by ;4,-;2y;mm. in breadth. In accord- 
ance with the same authority they are, when first discharged, cylindrical, but in a 
little while become flattened, and shaped like a flaxseed. ‘They are biciliate and 
contain a large number of small, orange-colored particles. From thirty-two to 
sixty-four of them are formed in one zoosporangium, and neither light nor time of 
day appear to have any influence upon their birth. Hildebrand states that their 
motile life lasts from eighteen to thirty-six hours, but according to Caspary, after 
continuing in motion for about an hour, they grow sluggish, sink, become globular, 
then siaene themselves and shortly undergoing transverse division, actively com- 
mence to form the new filament. 


Genus CHROOLEPUS, Aga. 


Fila distincte articulata, intricata, enormiter ramosa. 
Filaments distinctly articulate, intricate, irregularly branched. 


Cc. aureum, (Linyé.) Krz. 
C. filis ramossimis, in stratum aureo-brunneum, ad duas tres lineas crassum, ceespitosum et molle 
intricatis vel in cespitulos aggregatis ; articulis enormibus, diametro sesqui-, duplo triplove 
longioribus. 


Diam.—Max = .001”. 
Syn.— C. aureum, (Linné.) Ktrzinc. Raxennorst, Flora Europ. Algarum, Sect. III. p. 371. 
Hab.—Little Falls, New York; Godwinsville, New Jersey ; (Austin). Texas; (Ravenel). 


Filaments very much branched, interwoven to form a yellowish-brown softish mat, two or 
three lines in thickness; joints irregular, 13-3 times longer than broad. 


Remarks.—I am indebted to Mr. Austin for specimens which are labelled 
“Forms dense yellow-brown cushions on rocks, at Little Falls, New York and 


FRESH-WATER ALGA OF THE UNITED STATES. 205 


Godwinsville, New Jersey.” As dried, the plant is in extended, gray, felt-like 
masses. ‘The walls of the articles as seen with the microscope are thick and 
irregular, and the joints themselves are also very irregular, the end ones being often 
swollen and rounded so as to give the branches a sort of bulbous termination. 

Among the Alge collected in Texas by Prof. Ravenel, is a dried specimen (No. 
100), labelled “On Bark, Houston, Texas,” which I cannot separate from this 
species. It occurs in small tufts, which, as dried, are of a very decided orange, 
and, no doubt, were still brighter during life. The articles are not so irregular as 
in Mr, Austin’s specimens, but excepting in this and color when dried they agree 
very well. Besides these I have several specimens from the same source, which 
are in extended mats and agree in all respects with their northern brethren. 

Our American form appears to attain a greater diameter in its individual fila- 
ments than does the European variety, but I know of no other character separating 
it from the latter; and consequently must consider them identical. ‘The measure- 
ment given is an extreme one, .009” being commonly the limit. 


Genus BULBOTRICHIA, Kurtz. 


Fila indistincte articulata, achroa, firma, ramosa; rami in apice intumescentes, sporangia con- 
stituentes. 


Filaments indistinctly articulate, translucent, firm, branched; the ends of the branches swollen so 
as to form sporangia. 


B. albida, Woop (sp. nov.). 
B. strato albido, coriaceo vel crustaceo ; filis arcte intertextis, enormiter ramossissimis, coloris 
expertibus; sporangiis viridibus. 
Hab.—In muscis, Northern New Jersey; (Austin.) 


Forming a white leathery or crustaceous stratum ; thread closely interwoven, irregularly and 
plentifully branched, colorless; sporangia greenish. 


Remarks.—This curious little plant, which was sent me by Prof. Austin, occurs in 
minute white patches growing on mosses at the base of stumps in woods. Some- 
times these are encrusted abundantly with the carbonate of lime, when they are 
hard and crustaceous. ‘The sporangia appear to vary greatly in size; sometimes 
they resemble very closely a single spore (probably their commencing stage). The 
bases of the branches are rarely, if ever, furnished with the bulbous swelling, given 
by Rabenhorst as a generic distinction, but such enlargements do occasionally 
occur in the course of the filaments and branches. The filaments are composed 
of a series of cells, which are in places long, and have their end walls thin and not 
readily seen. 

Fig. 5, pl. 16, represents a part of a plant magnified 460 diameters. 


Famtty CHATOPHORACEA. 


Alge aquatice vel palustres, rarius terrestres, plerumque monoice vel dioice. Fila varia, seepe 
dichotome ramosa, haud raro fasciculatim ramulosa, plerumque in cespites vel pulvinulos cumulata, 
in muco gelatinoso subliquido vel firmo nidulantia. Propagatio fit tum oosporis, tum zoogonidiis, 
Zoogonidia oriuntur aut singula aut geminis aut cytioplasmatis divisione 8-16 in quoque sporangio. 


206 FRESH-WATER ALGA OF THE UNITED STATES. 


Aquatic, paludal, or rarely terrestrial alge, mostly monawcious or diecious. Filaments various, 
often dichotomously, but not rarely fasciculately branched, mostly aggregated into turfy masses or 
little cushions, and generally surrounded by a firm or subliquid gelatinons mucus. Propagation both 
by zoospores and resting spores. Zoospores arising either singly or by the division of the cytioplasm 
into 8-16 in each sporangium. 


Genus STIGEOCLONIUM. 


Fila articulata, simpliciter ramosa; rami ramulique sparsi, rarius fasciculatim approximati, in 
apicem acutum, sepe piliferum achroum attenuati et plerumque longe protensi, sepius ramellis 
brevibus subulatis instructi. (R.) 


Filaments articulate, simply branched; branches and branchlets sparse, rarely fasciculately ap- 
proximated, with their ends acute and frequently prolonged into an attenuate transparent seta or 
hair, and very often furnished with short subulate branches. 


Remarks.—Plants which" are certainly referable to this genus are abundant in 
every place in which I have ever looked for fresh-water alge. I confess, how- 
ever, that although very much time has been given to their study, I have not been 
able to make out any distinct specific characters, nor any identifications from the 
diagnoses of M. Rabenhorst. In a certain spring northeast of the city, there grows 
one of these forms, which I have closely watched for several seasons. In the. 
earlier state it appears at times to possess the characters of a young Chetophora 
(pl. 19, fig. 1), forming a small gelatinous base out of which the threads soon 
escape as they lengthen. It constituted a sort of mucoid layer adhering to the 
boards lining the stones with waving masses of projecting filaments six or even 
eight inches in length. The filaments were mostly about 3,17” in diameter and 
much interlaced. | 

The cells varied greatly in length, some being scarcely as long as broad, whilst 
others were eight or ten times longer. ‘The short cells were generally densely 
filled with endochrome, whilst the long ones were nearly empty. The branches 
often ended abruptly, but were more frequently tipped with ‘a long seta-like 
point. The method of branching is as varied as can be imagined, as is shown 
by fig. 4, pl. 16, and fig. 1, pl. 20, all taken from different plants of this species. 
I have frequently seen the production of zoospores, but no other method of repro- 
duction. In all cases a single motile body (fig. 4, pl. 16) was formed in each 
cell. These minute bodies are globular or pyriform, and within the cell exhibit 
no motion whatever. Their escape takes place very slowiy through a lateral slit 
in the wall. No cause of the motion is visible, and during the passage the 
zoospore is often very much squeezed out of shape. According to Braun (Ver- 
jungung), these zoospores possess a red eye-spot. I had not read his description 
at the time my observations were made, but did not notice any. The ZOOSpores 
germinated in the usual way, elongating and growing into a cell with a transparent 
seta-like end, and finally undergoing yepeated divisions to form the plant. 

M. Braun states that he has observed another process, in which the contents of 
a single cell undergoes a perpendicular division, so as to form four small zoospores, 
which escape from the cell in the same way as the larger one, and further says 
that he has never known these microgonidia to germinate, 


FRESH-WATER ALGA OF THE UNITED STATES. 207 


Genus DRAPARNALDIA, Ag. 


Fila articulata ramosa, e cellulis magnis, maxime hyalinis, fascia chlorophyllosa latiuscula ornatis, 
semper sterilibus formata, fasciculis penicillato-ramulosissimis, e cellulis minoribus fertilibus com- 
positis, plus minus dense obsessa. Articuli terminales omnium ramulorum inanes achroi steriles, in 
pilum hyalinum plus minus elongati. 


Filaments articulated, branched, formed of large cells which are chiefly hyaline, but furnished with 
a transverse chlorophyllous fascia, more or less densely clothed with penicillately ramulose fasciculi, 
formed of smaller fertile cells. Terminal articles of all the joints empty, trausparent, sterile, and 
elongate, in a more or less hyaline hair. 


D. glomerata, (Vavcu.) Aa. 

D. filis ramisque primariis achrois vel subachrois, ad 0.00147” crassis, articulis inferioribus 
diametro equalibus vel paulo brevioribus, geniculis manifesto constrictis, fasciis chlorophyl- 
losis angustis dilute viridibus; ramis primariis subrectangulo-patentibus, seepe oppositis ; 
ramulorum fasciculis confertis, patentibus, alternantibus vel oppositis, dense ramellosis, sub- 
ovalibus, obtusis. (R.) 


Syn.—D. glomerata, (VaucHER) AGAaRDH. RaBENHORsT, Flora Europ. Algarum, Sect. ILL. 
p. 38. 


Hab.—Rhode Island; (S. T. Olney) Thwaites. 


Filament and primary branches colorless or subcolorless, and reaching 0.00147” in diameter, 
lower articles about as long or a little shorter than broad, manifestly constricted at the 
joints, chlorophyl fascia narrow, light green; primary branches subrectangularly patent, 
often opposite; fasciculi of brapches crowded, patent, alternating, or opposite, densely 
ramellose, suboval, obtuse. 


Remarks.— According to M. Thwaites the true Dr. glomerata grows in Rhode 
Island, as he so identified specimens sent to him by Mr. Olney. ‘These specimens 
were, however, in all probability dried, and if this was so, I confess not to attach- 
ing much weight to the identification. The Draparnaldia, common near Philadelphia, 
is at once so like and yet so different from the description of D. glomerata, that I 
am unable to fully satisfy myself whether it be a variety of the European species 
or distinct from it. It differs very greatly in the thickness of the stem and pri- 
mary branches. I have given above Prof. Rabenhorst’s description of the Euro- 
pean variety, and now append one of th» plant growing in this neighborhood. 


Var. maxima. 

Dr. filig achrois, ad 0 004” crassis, articulis plerumque diametro duplo longioribus, in medio 
sepe valde tumidis; ramis primariis achrois vel subachrois, oppositis vel alternantibus vel 
ternatis, elongatis, dense ramellgsis, cum ramulis lanceolatis; ramulorum extremorum 
fasciculis dense ramelosis, ovatis vel late lanceolatis, plerumque confertis; ramulorum 
articulis inferioribus pleramque diametro (ad ters) subequalibus, articulis superioribus 
diametro duplo aut triplo longioribus, plerumque piliferis. 


Hab.—Prope Philadelphia ; Wood. 

Filament transparent, attaining a diameter of 0.004", its articles mostly twice as long as 
broad, strongly swollen in the middle; primary branches colorless or subcolorless, opposite, 
alternate or ternate, elongate, densely ramellose with the ramuli lanceolate; fasciculi of 
extreme branches densely ramellose, ovate, or broadly lanceolate, mostly crowded, inferior 
articles of the branches mostly about as long as broad (ers”), Superior articles two to three 
times as long, mostly pilifcrous. 


208 FRESH-WATER ALG OF THE UNITED STATES. 


Remari:s.—In this form there are almost always numerous little clusters of branch- 
lets, growing immediately from the main stem or large branches; such clusters are 
more rigid, more open, more broadly ovate, and less markedly piliferous than the 


others. 


D. plumosa, (VavcHer) AcarpH. . 
D. filis ramisque primariis hyalinis, pleramque )”” = 0.00179” crassis ; articutis diametro 
equalibus vel dimidio brevioribus, rarius paulo longioribus, geniculis vix aut modice con- 
strictis, fasciis chlorophyllosis angustis lete viridibus; articulis inferioribus ramulorum dia- 
metro ( yhq""—s33"") equalibus vel subduplo longioribus, pene torulosis, superioribus cylin- 
dricis ad ,3,’” attenuatis, diametro duplo triplo-quintuplo longioribus, plerumque non pili- 
feris; ramulorum fasciculis dense ramellosis, elongatis, acute lanceolatis, erecto-subap- 
pressis. (R.) 
Syn.—Dr. plumosa, (VaucHER) AGARDH. Rasenuorst, Flora Europ. Algarum, Sect. III. 
p. 382. 


Hab.—In rivulis et aquis quietis 


Filament and primary branches hyaline, mostly Jy”” = 0.00179” in diameter; articles as long as 
broad or one-half shorter, rarely a little longer, scarcely or slightly constricted at the joints, 
chlorophyl fascia bright green, narrow; lower articles of the branches about as long as 
broad (73,/” —z33'”) or nearly twice as long, somewhat torulose, the upper ones cylindrical, 
as small as s}5’”, two to five times longer than broad, mostly not piliferous ; fascicles of 
branches densely branched, elongate, acutely lanceolate, actually subappressed. 


Remarks.—I\ have found a Draparnaldia frequently, which I believe to represent 
the European D. plumosa. As I have preserved, however, no specimens or 
descriptions, I have simply copied the description of Prof. Rabenhorst. 


D. Billingsii, Wooo. 

D. valde gelatinosa; filis et ramis primariis achrois ad 729,” crassis, sparsissime ramosis, 
articulis diametro 2-6 plo longioribus, sepe medio valde tumidis ; fasciis chlorophyllis dilute 
viridibus, seepe nullis aut subnullis; ramulorum fasciculis distantibus, late ovalibus vel late 
triangularibus, alternantibus vel oppositis vel triplice verticellatis, sparse ramosis, patentissi- 
mis; ramulis pilis longissimis robustis terminalibus instructis; oosporis glubusis, moniliforme 
conjunctis ; sporodermate crasso. 

Syn.—D. Billingsti, Woon, Proc, Am. Philos. Soc., 1869, p. 148. 

Hab.—In aquis quietis, prope Philadelphia. 

Frond very gelatinous, filament and primary branches attaining a diameter of s},5”, very 
sparsely branched, their articles 2-6 times longer than broad, often very much swollen in 
the middle; chlorophyl band light green, frequently almost or entirely wanting ; fascicles 
of branches distant, broadly oval or triangular, alternate, opposite, or in whorls of three, 
very open; ultimate branchlets terminating in a long, robust, hyaline hair; resting spores 
globose, with thick walls, arranged in long moniliform sometimes branched filaments. 


Remarks.—I found this plant about the middle of March, 1869, floating on the 
surface of a little pool in the woods near Chelten Hills, a few miles north of 
Philadelphia. To the naked eye it appears as a gelatinous mass, resembling a 
Tetraspora, but when closely examined this translucent jelly is seen to be filled 
with rather distant greenish points, which are the little clusters of branches. The 
largest specimens I have seen had attained a length of nearly two inches. The 
filaments are very transparent and have the branches placed at long intervals. 


. 


FRESH-WATER ALG OF THE UNITED STATES. 209 


The ultimate branch groups are ovate or oval, and are remarkable for their open- 
ness, the branchlets being few in number and widely separated. Most of the ulti- 
mate branchlets are prolonged into a remarkably strong long hair. 

The cells of the main filaments are beautifully transparent, and are sometimes 
cylindrical but more generally are barrel-shaped. Both secondary and primary 
branches are often arranged singly, sometimes in pairs, not unfrequently in threes. 
When placed between two plates of glass and examined closely by the unaided 
eye, this species is readily distinguishable from our other Draparnaldia, by its fas- 
ciculi of branches being so widely separated as to be not at all confused with one 
another. 

I have a single specimen which I believe to be in fruit. The resting spores 
(fig. 6, pl. 14) are in long branched chains. They are more or less globose, with 
a very thick outer transparent wall, and an inner green endochrome, which very 
probably becomes brownish at maturity. Except when they are branched, these 
series of spores remind one very strongly of the filaments of some nostocs. 

I dedicate this very beautiful species to Dr. J. S. Billings, U.S. A., to whom I 
am under the greatest obligations for aid in the prosecution of this research, and 
whom I have ever found to unite the greatest scientific liberality with a strong en-. 
thusiasm for and able prosecution of the study of these lower vegetable forms. 

Since describing this species I have received the Microscopical Journal for 1869, 
containing Dr. Hicks’s paper upon D. ecruciata. The original description in the 
Linnean Transactions had escaped my notice. D.cruciata and D. Billingsii are 
exceedingly closely related, yet if Dr. Hicks’s description and figures be accurate 
they are probably distinct. ‘Thus in the last species the ramuli are not placed at 
right angles to the main filament, nor are they ever in fours, both of which are 
given as characters of D. cruciata. They are, on the contrary, in D. Billingsti at 
various angles, and commonly arise singly, but not unfrequently in pairs, and very 
rarely in threes. It is worthy of remark, on the other hand, that the figures of 
Dr. H. do not entirely agree with his description, as in no case are there more than 
two and frequently but a single branch at one place. The cells of the main fila- 
ment are also more barrel-shaped in our species than one would infer to be the 
case with D. cruciata. 

After all, however, I think it very possible that both forms belong to the one 
species. 

Fig. 6, pl. 14, represents a small portion of the frond with fertile branches mag- 
nified 460 diameters. 


Genus CHAXTOPHORA, ScHrank. 


Fila articulata ramique primarii radiatim dispositi, e cellulis vegetativis elongatis, fascia chloro- 
phyllosa in morem Draparnaldie et Stigeoclonii ornatis compositi, sursum in ramulos numero- 
sissimos, brevius articulatos, articulis extremis attenuatis sepe inanibus non aut vix piliferis in- 
structos, fasciculatos plus minus dense congestos divisi, massa gelatinosa firma, coriacea vel dura 
involuti, thallum globosum vel subglobosum aut plane expansum varie lobatum et fissum con- 
stituentes. (R.) 


Filaments articulated, with the primary branches radiately disposed, composed of elongated vege- 
tative cells, ornamented with a chlorophyllous fascia like a Draparnaldia or Stigeoclonium, distally 
27 September, 1872. 


210 FRESH-WATER ALG OF THE UNITED STATES. 


resolved into very numerous fasciculate, more or less densely congested branches, with shorter 
joints, their end joints alternate, often empty, either not or scarcely piliferous; surrounded by a firm 
coriaceous or hard jelly, so as to form a globose, subglobose, or expanded thallus. 


Remarks.—I have never seen the production of the zoospores in this genus, but 
they are said to arise one in a cell, and to escape by a sort of lateral splitting of 
the wall. 


C. elegans, (Rota) Acarpu. 
Ch. thallo globoso vel subgloboso, pisi vel cerasi magnitudine, dilute vel saturate viridi, nitido, 
superficie levi vel quasi tuberculata, elastice molli, nonnunquam indurato; fasciculorum 
ramulis laxis vel confertis, articulis extremis brevi-cuspidatis, seepe piliferis. 


Syn.—C. elegans, (RotH) AcarpH. Rasenuorst, Flora Europ. Algarum, Sect. III. p. 384. 
Hab.—United States. 


Thallus globose or subglobose, of the size of a pea or cherry, light green, with the surface 
smooth or quasituberculate, elastic but soft, sometimes indurated; branches of the fasciculi 
lax or crowded; end articles shortly cuspidate, often piliferous. 


Remarks.—One of the commonest of our fresh-water alge is a plant belonging 
‘to this genus, which I think is probably the C. elegans of Roth. I am, how- 
ever, unable to discover any characters separating C. pisiformis, C’. elegans, and 
perhaps (. tuberculosa, and hardly know by which of the three names our Ameri- 
can form should be known. Our plant grows generally in shaded pools, springs, 
and ditches in great abundance, adhering as little translucent balls to grasses, 
leaves, twigs, or anything that may be in the water. The size of the frond varies 
from the young one, not so large as a pin’s head, to the old matured one, which 
may be nearly an inch in diameter. The color also varies greatly. It is always 
some shade of a pure green. The-surface is mostly smooth, but sometimes it is 
so puckered up as to be a mass of large flat tubercles. It is these forms that I 
suppose to represent C. tuberculosa. The thallus is generally elastic, but at the 
same time soft, so that although readily compressed and pushed out of shape, it is 
entirely mashed with some difficulty, especially as, owing to its slipperiness, it 
constantly escapes from the grasp. 

In regard to the individual filaments, the method of their branching and the 
proportionate length and breadth of the cells vary very much in different in- 
dividuals and probably at different ages of the same individual. : 

Fig. 5, pl. 6, represents rather indifferently well a young individual of this 
species, 


C. endivizfolia, (Rorz) Ag. 

Ch. thallo lineari, subplano, semipollicari vel pollicari, nonnunquam valde elongato, late vel 
obscure viridi, dichotomo-subreticulatum-laciniato (nonnunquam habitu Ricci JSluttantis) ; 
filis ramisque primariis plerumque achrois, passim viridi-zonatis, parallelis; ramulorum fasci- 
culis lateralibus, plus minus densis, divaricato-patentibus; articulis plus minus tumidis, 
diametro squalibus vel subequalibus; geniculis constrictis; cytioplasmate granuloso 
effuso. (R.) Species mihi ignota. 


Syn.— C. endiviefolia, (Rorn) Acarps. Rasenuorst, Flora Europ. Algarum, Sect. III. 
p. 383. 


FRESH-WATER ALG OF THE UNITED STATES. 211 


Hab.—South Carolina; (Ravenel) Wood. Rhode Island; (S. T. Olney) Thwaites. 


Thallus linear, flattish, of half to a whole thumb’s breadth, sometimes greatly elongate, bright 
or obscure green, dichotomously subreticulately laciniate (sometimes with the habit of 
Riccia fluitans) ; filament and primary branches mostly colorless, sometimes zoned with green, 

_ parallel; lateral fasciculi of branches more or less dense, divaricately patent ; joints more or 
less tumid, diameter equal or subequal; joints constricted; cytioplasm effused granulate. 


Remarks.—T have never seen a living or well-preserved specimen of this species, 
and have, therefore, here simply copied the description of Prof. Rabenhorst. Prof. 
Ravenel has sent to me dried alge labelled, and I think correctly, as belonging to 
this species, but their condition did not allow any scientific study of them. 


Genus PILINIA, Krz. 


Fila articulata, erecta, simplicia vel dichotome ramosa, basi affixa, in stratum crustaceum sub- 
spongiosum, fragile aggregata. Propagatio adhuc ignota. 

Filaments articulate, erect, dichotomously branched, fixed by the base, aggregated into a some- 
what spongy fragile crustaceous stratum. Method of propagation unknown. 


P. diluta, Woon, (sp. nov.) 
P. rupicola, in strato cano-viridi disposita; filis ramisque fasciculatis, apice obtusis; articulis 
diametro 14 plo—3 plo longioribus. : 
Diam.—Max. 0.0004”. 
Hab.—In fontibus maximis, prope Bellefonte, Centre County, Pennsylvania; Wood. 
Growing on stones and rocks, forming a grayish-green stratum; filaments and branches fasci- 
culate, with the apices obtuse ; joints 14-34 times longer than broad. 


Remarks.—Near Bellefonte, Centre County, Pennsylvania, there issues from the 
limestone rocks the largest spring I have ever seen, giving rise to a creek-like tor- 
rent, which, supplies the city with water, and passes on scarcely diminished in 
volume, In this spring grows the curious alge under consideration, forming a 
somewhat lubricous crustaceous and stony stratum on the stones and rocks in the 
basin. This stratum is of a grayish-green color, and is quite friable, breaking in 
the direction of the filaments with the greatest possible readiness. When placed 
under the microscope it is seen to be composed of filaments whose course is a 
direct one from the under to the upper surface. They are apparently rigid, pre- 
serving their courses, and not being intermatted. ‘They are composed of cylindri- 
val, confervoid cells, and are dichotomously branched, and yet when viewed as 
a whole the filament and its branches form a sort of fasciculus. The basal cell 
or cells appear to be globular. When I collected this plant I was forced by cir- 
tumstances to put the specimens in carbolic-acid water for future study, and, 
therefore, I have had no opportunity of studying their method of reproduction. 
I am not altogether satisfied in referring this plant to the Pilinia, and yet all the 
most important of the characters given by Rabenhorst are preserved by it. It 
certainly, however, differs very greatly from P. rimosa, Ktz. 


Genus APHANOCH ATE, Braun. 


Fila distincte articulata, prostrata, repentia, interdum in stratum irregulare plus minusve concreta 
ramulis repentibus vel adscendentibus ; cellulis chlorophyllaceis, apice vel dorso setigeris. Propa- 


gatio zoogonidiis. 


212 FRESH-WATER ALG& OF THE UNITED STATES. 


Threads distinctly articulate, prostrate, creeping, sometimes more or less concreted into an irregular 
stratum; branches creeping or ascending; chlorophyllous cells with the dorsum or apex setigerous. 


Propagation by zoospores. 


Remarks.—Sexual reproduction has not as yet been discovered in this genus. 
According to Dr. Braun (Verjiing., Translation of the Ray Society, p. 184, &c.) 
two zoospores are generally formed in a cell by a division of its contents parallel 
to the septa, but occasionally this division not taking place, the cell contents are 
resolved into a single zoospore. ‘The zoospores themselves are nearly globular, 
biciliate, and unprovided with any reddish eye-spot. 


A. repens, Braun. 

A. filis procumbentibus plerumque simplicibus; articulis cylindricis aut tumidis, diametro sub 
equalibus ad 1-2 plo longioribus ; setis e cellularum dorso egressis, plerumque singulis sed in- 
terdum geminis, interdum nullis. 

Diam.—Artic. ps25y"—tz800" = -00025—.0004”, 

Syn.—A. repens, Braun. Raxpenworst, Flora. Europ Algarum, Sect. III p. 391. 

Hab.—In Cdogoniis, prope Philadelphia; Wood. 

Filaments procumbent, mostly simple; articles cylindrical or tumid, from as long as broad to 
twice as long; seta arising from the back of the cells, generally single, sometimes geminate, 
sometimes wanting. 


Remarks.—The specimens from which the above description was drawn up, were 
found growing on the filaments of Cidogonium mirabile, Woop. They were re- 
markable for the rarity with which they were branched, for in but two or three 
cases out of a great number, were any branches detected. ‘The articles were fre- 
quently twice as long as broad. In~-both these particulars the plant differs from 
the typical European A. repens, but the descriptions of that form are so short and 
imperfect that I have preferred retaining the name for the American plant. 

Fig. 5, pl. 14, represents an ordinarily formed specimen magnified 460 diameters. 
It had been kept for some time in weak carbolic-acid solution, and although the 
green of the chlorophyll was perfectly preserved, the stumps only of the sete 
were visible. How long the perfect sete are I canndt at present say, not having 
made any notes on the fresh specimens, 


Genus COLEOCH ETE, Bris. (1844). 


Fila articulata ramosa aut in pulvinulum conjuncta aut in thallaom planum subdisciformem 
parenchymaticum concreta; articuli oblongi, antice plus minus dilatati, angulo superiori vel dorso 
sepe in setam basi vaginatam producti. Propagatio fit tum oosporis foecundatione sexuali ortis, 
tum zoogonidiis. Zoogonidia in quaque cellula fructifera unica, forma subglobosa vel late ovalia, 
polo antico ciliis vibratoriis binis instructa. (R.) 

Filaments articulated, branched, either conjoined into a little cumulated mass or parenchematously 
concreted into a plain subdisciform thallus; articles oblong anteriorly, more or less dilated, often 
farnished with a long seta on their dorsum or superior angle. Propagation occurring by means of 
oospores, formed by sexual organs or by zoospores. Zoospores subglobose or broadly oval, formed 
singly in the fertile cell, furnished at their anterior pole with vibratile cilia, 


Remarks.—I have seen a large number of specimens of, as I believe, two distinct 
species of this genus, but never having found any fruiting fronds, have not been 


FRESH-WATER ALGH& OF THE UNITED STATES. 213 


able to identify them. One of the forms grows in this immediate locality, and is very 
probably C. scutata, Bréb, The other was collected in Northern Michigan. It is 
characterized by its frond never being disciform, although composed of a single 
plane of cells parenchematously united. 


Cuass RHODOPHYCE A. 


Algee multicellulares, vegetatione terminalis non limitata pradite 
plerumque trioice. 

Thallus e cellularum seriebus vel stratis singulis vel pluribus compo- 
situs, aut nudus aut e cellularum strato corticatus, forma quam maxime 
varius; membranaceus (Porphyridium), crustaceus (Hildenbrandtia), 
filamentosus et verticillatim ramosus (Batrachospermum, Thorea), fascii- 
formis (Bangia), foliaceus, etc. 

Cytioplasma plerumque rhodophyllo (Cohn), rarius phycho-chromate 
coloratum, granula amyloidea vel amylacea et seepe guttulas oleosas 
includens. 

Propagationis organa triplicis indolis, saepissime in plantas distinctas 
disposita. 

Ll. Organa mascula vel antherida e fasciculis cellurarum plerumque mo- 
niliformibus ramosis, denique in spermatozoidea vel spermatia foecun- 
dantia (Sporidia I. Ag.) oblonga vel ovalia, achrod, immobilia dissolutis 
formata. 

2. Organa feminea vel cystocarpia Ktz. e soris nonnunquam monilifor- 
mibus formata, qui e placenta saepissime corticali evolvuntur, nudi vel 
cuticula mucilaginosa vel involucro inclusi, denique sporas (polysporas) 
numerosas immobiles mox germinantes emittunt. Foecundatur cysto- 
carpium statu primordiali ope organi piliformis (¢richogyne Thuret et 
Bornet) quorum spermatia copulantur. 

3. Tetrasporangia e cellula corticali unica valde intumescente formata, 
divisione utriculi primordialis cruciata quadrilocularia; in quoque loculo 
(cellulis secundartis, sororits) spora unica (tetraspora) se format, quae sine 
foecundatione germinat. (R.) 


Multicellular alge, mostly trizcious, furnished with unlimited not ter- 
minal vegetation. 

Thallus composed of cells in rows or in a simple or multiple stratum, 
either bare or provided with cortical strata of cells, exceedingly various 
in form; membranaceous (Pophyridium), crustaceous (Hildenbrandtia), 
filamentous and verticillately branched (Batrachospermum, Thorea), 
fasciate (Bangia), foliaceous, &c. 

Cytioplasm mostly rhodophyllous, rarely phycochromatously colored, 
including amyloid granules or starch and frequently oil drops. 

Propagation by means of three immotile organs, generally placed 


upon distinct plants. . . 
1. Antheridia composed of mostly moniliformly branched fascicles of 


214 FRESH-WATER ALG# OF THE UNITED STATES. 


cells, which dissolve into oblong, oval, transparent immotile spermato- 
zoids (Sporidia Ag.). - ; 

2. Cystocarpia Ktz., or Pistillidia, formed of somewhat moniliform sori, 
which are evolved from a generally cortical placenta, and are naked or 
surrounded by a mucilaginous cuticle or involucre, and finally emit 
numerous immotile spores (polyspores), which quickly germinate. The 
fecundation of the cystocarpia occurs in their primordial state by con- 
tact of the spermatia with a piliform organ known as trichogonia. 

3. Tetrasporangia formed of single, greatly swollen cortical cells, be- 
coming cruciately quadrilocular by division of the primordial utricle; in 
each loculus (secundary or sister cells) a single spore (fetraspore) forms, 
which germinates without fecundation. 


Famity PORPHYRACEA. 


Thallus mucoso-membranaceus, foliaceus vel filamentosus, e cellularum seriebus vel strato unico 
formatus, plerumque purpurascens, valde lubricus. 

Vegetatio fit cellularum divisione in duas vel omnes directiones repetita. 

Propagatio fit tetrasporis. Cystocarpia nondum observata. 

Thallus mucous-membranous, foliaceous or filamentous, formed of cells in series or in a single stra- 
tum, mostly purplish, very slippery. 

Growth taking place by repeated division of the cells in two or all directions. 

Propagation by means of tetraspores. Cystocarps not yet observed. 


Remarks.—The only species of this family as yet observed in North America 
can hardly be said to have a definite thallus. They are rather multitudes of cells 
heaped together and closely attached to one another into a shapeless expanded 
mass. 


Genus PORPHRYDIUM, Nase. (1849). 
Thallus mucoso-membranaceus, subcrustaceus, longe lateque expansus, e cellulis globosis vel 
polyedricis compositus. Propagatio adhuc ignota. 
Thallus mucous-membranous, subcrustaceous, long and widely expanded, composed of globose or 


polyhedral cells. Propagation unknown. 


P. cruentum, (Ac.) Nase. 
P. thallo saturate purpuro-sanguineo, lubrico; cellulis anguloso-rotundatis. (R.) 


Diam.—0.0002'7”—0.00035". (R.) 
Hab.—New York. 


Syn.—P. cruentum, (Agarp.) Naxrcent, RaAsennorst, Flora Europ. Algarum, Sect, III. 
p. 39%. 


- Thallus deep crimson purple, slippery ; cells angled and rounded. 


Remarks.—The only specimen I have seen of this species was a little speck, 
adherent to a bone picked up on Governor’s Island, in New York Harbor. It is 
very probable that it was a recent arrival, brought over, perchance, by some emi- 
grant. For it I am indebted to Dr. Billings, U.S. A. The description and 


FRESH-WATER ALGA OF THE UNITED STATES. 215 


measurements given above are copied from Prof. Rabenhorst’s work. My specimen 
agrees well with it. 


P. magnificum, Woop. 


P. cellulis globosis vel subglobosis, spe nonnihil polygonis et in massam indefinite expansam 
confluentibus ; cytioplasmate purpureo, granulato; cytiodermate crasso, haud lamelloso. — 

Diam.—Cell cum. tegum. sz8g9—sahh5. Tegum. 35459—10h00- 

Syn.—P. magnificum, Woop, Proc. Am. Philos. Soc., 1869, p. 144. 

Hab.—In terra humida, Texas; Prof. Ravenel. 

Cells globose or subglobose, often somewhat polygonal and conjoined into an indefinite mass; 
endochrome purple, granulate; cell wall thick, not laminate. 


Remarks.—This species, which was collected in Texas by Prof. Ravenel, growing, 
I believe, on wet sand, is very distinct from the European plant, differing essenti- 
ally in size and form. In some instances the cells have a greenish tint, but this is 
possibly owing to immaturity, as such cells seem smaller than others. The whole 
mass to the eye has a very rosy purple tint, and although under the microscope it 
appears much darker and more purple, yet it often retains some of the roseate hue. 
At the edges of the masses the dark-reddish color often gives way to a very decided 
greenish tint, presenting an appearance which is very well represented in the 
drawing of the preceding species, in M. Mencruini’s Monographia Nostochinearum 
ftalicarum, &e., Memoire della Reale Academia delle Scienze di Torrino. The cells 
are often closely united by their thick coats into a very coherent mass. With the 
ordinary cells I have occasionally seen other larger ones, of an orange color, with 
very thick walls. Are these resting spores ? 

Fig. , pl. 19, represents single cells of this plant magnified 750 diameters. 


Famity CHANTRANSIACE. 


Thallus filamentosus. Fila articulata, e cellularum serie unica formata, ramosa, stricta, nuda, 
raro passim corticata, rami superne fasciculatim ramellosi; articuli cylindrici. Cytioderma, homo- 
geneum, maxime hyalinum. Cytioplasma homogeneum, plerumque purpurascens. Propagatio fit 
polysporis immobilibus, ovalibus, in ramellorum apice vel lateraliter formatis, corymboso aggregatis. 
Antheridia subglobosa, terminalia. Tetraspora raro observate. 


Thallus filamentous. Threads articulate, formed of a single series of cells, branched, straight, 
bare, rarely here and there articulate; branches above fasciculately branched; joints cylindrical. 
Cytioderm homogeneous, mostly hyaline, cytioplasm homogeneous, mostly purplish. Propagation 
by immovable oval polyspores formed on the ends of the branches or laterally and corymbosely 
aggregate. Antheridia subglobose terminal. Tetraspores rarely observed. 


Genus CHANTRANSIA, Fxrizs. 


Familie genus unicum. 
The only genus of the family. 


Cc. expansa, Woop. . 
C. cespitosa, in lapide stratum saturate violaceo-purpureum lubricum, indefinite expansum, 
formans; filis purpureis, modice ramosis, fere 2 lineas longis et ramis pleramque strictis et 
rectis, sepe elongatis; ramulis fertilibus brevibus, ascendentibus; articulis diametro 3-8 plo 


216 FRESH-WATER ALGA OF THE UNITED STATES. 


longioribus, extremis obtusis; polysporis in ramellis lateralibus racemosim et confertim 
cumulatis, ovalibus vel nonnihil obovatis. 

Diam.—Fil. gpyq" = 0004". Spor. transv. gg5y” =.00027 long. gJoy = .0004”. 

Syn.—C. expansa, Woop, Prodomus, Proc. Amer. Philos. Soc., 1869. 


Hab.—In rivulis, prope Philadelphia. 


Cespitose, forming a dark purple, slippery, indefinite stratum on stones; filaments purple,. 
moderately branched, almost 2 lines long, together with the branches strict and straight, 
often elongate; infertile branches sometimes very few, sometimes very numerous ; fertile 
branches short, ascending ; joints 3-8 times as long as their diameter, the final articles ob- 
tusely rounded: polyspores racemose, crowded on the fertile branches, oval or somewhat 


ovate. 


Remarks.—This species was found growing in a running stream, forming a felty 
slimy coating upon large stones, looking so much like a stratum of Oscillatoria, 
that when I gathered it I thought it probably was a representative of that genus. 
The stratum, however, when carefully examined, is seen to.be made up of an in- 
definite number of minute, very closely approximate tufts. The color was a dark 
dull purple. The plant may possibly be the Chantransia violacea, of Kitz1ne, 
which it resembles in many particulars, but it is nearly twice as long and the fila- 
ments are considerably thicker. Its habit of growth also seems to be essentially 
different from that of the European plant, so that I have finally decided to con- 
sider it a distinct species. The exact locality of its growth is in a thickly-shaded 
portion of the stream that runs along the North Pennsylvania Railroad, just this 
side of Chelten Hills. 

Fig. 2, pl. 19, represents a filament magnified 125 diameters; fig. 2a, a part of 
a fertile branch magnified 460 diameters, 


€. macrospora, Woop (sp. nov.). 

C. cespitosa, subpollicaris, olivaceo-grisea vel saturate violaceo-purpurea; filis ramosis et 
ramis plerumque strictis et rectis, et elongatis; articulis diametro 3-8 plo longioribus; ramu- 
lis fertilibus brevissimis ; polysporis singulis vel geminis, sparsis, seepe distantibus, globosis, 
interdum nonnihil ovalibus. 


Diam.—Fil. plerumque .0008—max. .001. Polysp. .0009. 
Hab.—South Carolina; (Ravenel). 


Cespitose, about an inch long, olive-gray to deep-violet purple ; filaments a good deal branched, 
with the branches mostly straight and elongated ; fertile branches very short; articles 3-8 
times longer tlfan broad ; spores single or geminate, few, often distant, globose, or sometimes 
slightly oval. 


Remarks.—I am indebted to Prof. Ravenel for specimens of this species pre- 
served in carbolic-acid water. They are labelled, “Dull olive green, growing 
against wooden boards in spring, Nov. 5, 1869. Aiken, South Carolina.” The 
most of the mass is of the color noted, or at least approaches it, but a portion is 
almost blackish purple. The species is a very distinct one, characterized by 
the larger diameter of its articles and spores, by the paucity and shape of the 
latter, as well as by its variance in coloration. In some old specimens the cell 
wall is distinctly lamellate. I have only seen fruit on the purple filaments, The 


FRESH-WATER ALGA OF THE UNITED STATES 217 


spores, apparently not mature, have a greenish-brownish tint. I have also received 
from Prof. Ravenel dried alge, which, apparently, are the same species as those 
from which this description has been written, but which, not being in fruit, cannot 
be absolutely identified. They are, as dried, of a bright bluish-green, and attain 
the length of an inch and a half or more. 


Fig. 3, pl. 19, represents a part of a branch of this plant magnified 460 
diameters. 


Famity BATRACHOSPERMACEA. 


Alge dioice. Thallus filamentosus, articulatus, ramosus, aut violaceus, violaceo-purpureus 
vel ceruleo-viridis, muco matricali involutus; filis primariis ramisque e cellularum serie unica 
centrali primaria et seriebus numerosis secundariis parallelis continuis vel interruptis externis com- 
positis, aut ramulorum fasciculis verticillatis globoso vel subgloboso dense conglobatis equali 
distantia obsitis, aut ramulis simplicibus vel dichotomis dense ubique vestitis. | Vegetatio 
terminalis. 


Diecious alge. Thallus filamentous, articulate, branched, violet or violet-purple or bluish-green, 
covered with mucous; primary filament and branches composed of a single central series of cells, 
and numerous external, parallel, continuous, or interrupted secondary series; either furnished with 
globosely or subglobosely densely conglobate, equally distant verticillate fasciculi of branches, or 
everywhere densely covered with simple or dichotomous branches. Vegetation terminal. 


Genus BATRACHOSPERMUM, Rorg, 1800. 


Thallus filamentosus, moniliformis, e cellularum serie unica medullari, accessoriis parallelis corti- 
cata compositis, ramulorum fasciculis subgloboso-conglobatis obsessus. 


Thallus moniliform, composed of a simple series of medullary cells and cortical accessory parallel 
series, clothed with subglobosely conglobate fasciculi of branches. 


Remarks.—The Batrachosperms are amongst the very largest of the fresh-water 
alge, forming gelatinous branched masses from a few inches to even more than a 
foot in length. The fronds are very freely and very irregularly branched, and are 
evidently composed throughout, #.¢., both in regard to the main filaments and the 
branches, of two portions, a central axis and much more slender short transverse 
branchlets, which often end in a long hair, and are arranged more or less exclu- 
sively in groups, so as to form, to the naked eye, at regular intervals, little balls or 
knots, the whole plant thus presenting a sort of moniliform aspect. Sometimes, 
however, these glomeruli are placed so closely together, and grow so large that 
they become confluent, and the branch to which they are attached appears as a 
uniform thick and very gelatinous cylindrical cord. 

The axis both of the stem and the branches of a Batrachosperm consist ori- 
ginally of but a single series of cells. The development of new cells takes place 
in two ways, the one of which results simply in an increase in the length of the 
axis, the other in the production of branches. The first of these is the ordinary 
process of cell multiplication by division, and occurs only in the end cells, so that 
no new cells are ever formed in the central portions of the axis, which increases 
in length solely by the addition of new cells at the end, and by longitudinal growth 
of the old ones. ‘The first step towards the formation of a branch is the produc- 


tion of a little pouch-like protrusion near the upper end of acell. This increases 
28 September, 1872. 


218 FRESH-WATER ALG OF THE UNITED STATES. 


in size and soon being cut off from the parent-cell by a partition, forms a complete 
cell, the starting point of a new branch. If this cell has been formed alone, with- 
out companions, it is the beginning of a main branch, and divides after a very brief 
period transversely, the new cell thus arising in a little while itself divides, and so 
the process goes on until the axis of a large branch, similar to the parent axis is 
developed, and which, like the parent axis, increases only. by a division of the end 
cell and longitudinal growth of the central ones. 

When a glomerulus is to be formed instead of a single pouch, a number appear 
around the upper end of a cell, and become cut off as new cells. Each of these 
is the starting point of a new row of cells, which not only grows, at least up to 
a certain point, by the division of the end cells, but which also gives rise to a 
large number of branches in a way precisely similar to that in which it itself was 
developed, i. ¢., by the formation of little lateral protrusions, &c. ‘These secondary 
branches have a life-history similar to that of the branch whose offspring they are. 
They continually give origin to new branchlets in the way just described, which 
branchlets themselves produce fresh offshoots, and so it goes on until at last the 
forest of branchlets making up the dense glomerulus is evolved. It has been 
just stated that the original axis of the main filament or any branch is composed 
of a single simple series of large cells; when an old Batrachosperm is placed under 
the microscope, however, it is at once evident that the axis is in reality formed of 
such a series lying in the centre and covered over and often hidden’ by numerous 
longitudinal series of smaller cells. These latter do not belong to the original 
axis, but are secondary additionssto it, and arise in this way. Whilst a glomerulus 
is being developed certain of the basal cells of its constituent branches give origin 
in the usual manner to branchlets, which, instead of growing outward to form a 
part of the glomerulus, grow upwards or downwards, closely hugging and finally 
enveloping the original axis, and at last forming a distinct cortical layer to it. 

Very frequently in well-advanced Batrachosperms there will be seen scattered 
among the glomerulus large, round, firm, dense balls composed of a great number of 
small closely-attached cells. These are the reproductive bodies, According to H. 
Graf zu Solms-Laubach (Botanische Zeitung, 1867, p. 161), they are the result of 
sexual reproduction, and are developed from antheridia and trichogonia (female 
organs) in the following manner :— 

The antheridia are small roundish cells full of a colorless protoplasm, which is 
remarkable for the very numerous bright granules which it contains. They occur 
either scattered or in groups, and are placed upon the upper ends of peculiar ovate 
cells, also filled with a colorless protoplasm. Most frequently there is a single 
antheridium to the basal cell, sometimes two; the latter number appears never to be 
exceeded. When matured, the antheridia open and allow their contents to escape 
in the form of roundish or flattened bodies, which never, as far as known, acquire 
cilia, and have, therefore, no power of spontaneous motion. These bodies, which 
are believed to be spermatozoids, are unprovided with anything like an external 
membrane, and are composed of protoplasm identical with that in the antheridium. 

Whilst these changes are occurring, certain cells in other localities are being trans- 
formed into female organs, to which our author applies the name of Trichogonia. 


FRESH-WATER ALG# OF THE UNITED STATES. 219 


These are borne upon cells similar to those supporting the antheridia. At first 
they are not markedly different from the other cells, but soon undergo a very rapid 
growth. This is not, however, regular, and is not partaken of by a band of tissue 
about one-third way from the basal end, so that at last a long somewhat flask- 
shaped cell is produced, with a very marked contraction at the point indicated, 
separating it into two portions. The wall of this cell is thin but very distinct, and 
the cavity is filled with a homogeneous or very sparsely granular protoplasm, which 
is continuous through the narrow neck-like portion. After a time there appear 
one or more large irregular vacuoles, with actively moving corpuscles in them, and 
at the same time the neck appears to be stopped with a slimy substance. Careful 
examination with reagents shows that this is cellulose, and that it does not com- 
pletely block the passage-way through the isthmus. At this time there appear lying 
upon the free end of the trichogonia globular or flattened bodies, without external 
membrane, corresponding in all respects with those already described as being pro- 
duced in the antheridia. The end of the trichogonium generally enlarges at this 
period into a sort of roundish knob, and by and by the end wall between this and 
one of these globules becomes absorbed, so that there is a free communication 
between the two. Whilst this is going on the globule acquires a thin, delicate 
coat, and there appears in it a vacuole similar to those preexisting in the tricho- 
gonium. : 

The first result of this impregnation of the trichogonium is the deposit of new 
cellulose, and the complete blocking up of the passage-way through the isthmus 
or narrowed portion. Already before the fecufndation, the upper cells of the 
branches supporting the trichogonia have produced numerous branchlets, which 
growing upwards more or less completely cover that organ. After impregnation 
the cells near to the trichogonium become much larger and broader, their vacuoles 
disappear, and are replaced by a dense granular dark greenish-brown protoplasm. 

These cells now show a great activity in the production of numerous branches 
in the usual way, but it is the upper two alone which, with the trichogontum that 
they support, are concerned in the formation of the fruit glomerulus. These put 
out all over their surface an immense number of protrusions, which soon in the 
ordinary way become the parents of as many twigs or branchlets, which growing 
and branching, precisely as do the vegetative branches, soon become excessively 
crowded. ‘The base of the trichogonium participates also in this production of 
branches, and at last a dense ball is formed of pseudoparenchymatous tissue by 
the forced adhesion of the crowded twigs. The central cells of the glomerulus 
thus formed are very large and bladder-like. The outer part of the ball is com- 
posed of innumerable radiating rows of small cells, the end cell of each branch 
being roundish so as to present a convex external face. At maturity these 
cells open and allow their contents to escape as round masses, which appear to 
have no membrane, but begin at once to grow and secrete cellulose. ‘heir after- 
history has not been made out with absolute certainty, but they are believed to 


directly develop the new plant. 


220 FRESH-WATER ALG OF THE UNITED STATES. 


B. moniliforme, (Rorz.) 

B. pollicare, bi- tripollicare, raro pedale, muco gelatinoso plus minus firmo involutum, viola-~ 
ceum, fuscum, rufo-brunneum, purpureum vel ceruleo-viridiscens, vage ramossissimum ; ramu- 
lorum articulis omnibus conformibus, oblongo-subclavatis, extremis nonnunquam setigeris; 
internodiis nudis vel ramulis accessoriis singulis sparsis instructis. 

Diam.—Tetrasp. globulus 235 = .006. 

Syn.—B. moniliforme, RorH. RaBenuorst, Flora Europ. Algarum, Sect. III. p. 405. 
Hab.—In aquis puris, Michigan; Gray. New York; Bailey. Virginia; Jackson, Alabama ; 
Tuomey. South Carolina; (Ravenel) Pennsylvania; New Jersey; Wood. 

One inch to a foot in length, clothed with a more or less firm gelatinous mucus, violet, fuscous, 
reddish-brown, purple, or bluish-green, vaguely and profusely branched; joints of the 
branches similar, oblong-subclavate, the outer ones sometimes setigerous; internodes naked 
or furnished with a few scattered accessory branchlets. 


Remarks.—This species is very abundant in fresh, cool rivulets, in springs, in 
limestone waters, in pine-barren streams, and even occasionally in ditches, wherever 
I have botanized in Pennsylvania and New Jersey. It varies greatly in size, in 
color, and other particulars. 

The branchlets, as I have observed them, are most generally not setigerous, but 
at times they are provided with seta of moderate length. 

I have found numerous fruiting fronds, but in none of them was the fruit in 
great abundance, not nearly so much so as in the Rocky Mountain species. 


B. vagum, (Rots) Acarpu. 


B. vage ramossissimum, uni- vel tripollicare, fascum vel erugineum; internodiis inferioribus 
ramellis numerosis obessis, superioribus nudis vel subnudis; ramulorum articulis extremis 
setis longissimis instructis. 


Diam.—Tetrasp. globulus 7435 = .00333. 

Syn.—B. vagum, (RotH) Acarpu, Rasenuorst, Flora Europ. Algarum, Sect. III. p. 406. 
Hab.—In aquis quietis, Uintah Mountains, Nevada; (S. Watson). 

Vaguely branched, one to three inches long, brownish or xruginous; internodes—the inferior 


covered with a dense mass of branchlets—the superior naked, or nearly so; last articles ot 
the branchlets provided with an extremely long seta. 


Remarks.—I have received from Mr, Sereno Watson some half a dozen dried 
alge, which I have referred to B. vagum, with some doubt. They are labelled as 
having grown in shallow water, ina beaver pond, in Pack’s Cafion, Unitas, Uintah 
Mountains, Nevada, at an altitude of 7000 feet. All the descriptions of B. vaguin 
which I have seen are singularly imperfect; in none is it stated how large the spore 
masses grow, and how plentifully the branchlets are provided with seta. As far 
as the descriptions go, however, my specimens agree with them, and I have, there- 
fore, refrained from indicating a new species. The plants are remarkable for the 
profusion and extreme length of the seta, and for the quantity of fruit which 
they produce. Tie fruit masses are small but very compact, scarcely more than 
half the size of those of the preceding species. The verticles of branchlets are 
often completely joined, and as it were almost swallowed up by the mass of inter- 
vening scattered branchlets which arise directly from the main axis, In the distal 


FRESH-WATER ALG OF THE UNITED STATES. 221 


portions of the fronds, however, the glomeruli are more fasciculate and more 
distinct, for although sometimes so close as to be almost confluent at their spread- 
ing edges, at their bases they are distinct. This species very probably attains a 
much larger size than indicated by my specimens, and possibly varies as much in 
color as B. moniliforme. 


’ 


Genus TUOMEYA, Harvey. 


“Frond cartilaginous, continuous, solid, at first transversely banded, afterwards annularly con- 
stricted ; composed of a longitudinal axis, and two strata of peripheric cells. Axis columnar, 
consisting of several longitudinal cohering filaments, beset with closely placed whorls of moniliform 
ramelli, whose branches anastomose horizontally and vertically into acellular peripheric membrane, 
which is coated externally with moniliform filaments, gradually developed. Fructification probably 
in the superficial filaments. 


T. fluviatilis, Harvey. 
Hab.—On stones, in rivers and streams. River in Alabama; Prof. Tuomey. Near Fred- 
ericksburg, Virginia; Prof. Bailey. 


Fronds tufted, an inch or two in height, scarcely as thick as a hog’s bristle, much and irregu- 
larly branched, bushy; the branches alternate or secund, scattered or crowded, twice or 
thrice divided, and set with scattered patent ramuli which are slightly constricted at the in- 
terstices, and taper to an obtuse point. When young the branches and ramuli are perfectly 
cylindrical, and when examined under a low power of the microscope show a surface com- 
posed of minute, dotlike cells, placed close together, and marked at short intervals with dark- 
colored transverse bands. These bands disappear under a higher magnifying power. They 
are indications of the nodes of the axis of the frond seen through the peripheric stratum. 
In old, fully developed specimens the branches and ramuli are annularly constricted at short 
intervals, the nodes becoming swollen, whilst the internodes remain unchanged. ‘When a 
young branch is bruised between two pieces of glass the axis may be readily extracted. It 
consists of several parallel longitudinal jointed threads combined together at closely-placed 
nodes, from which issue horizontal dichotomous filaments, composed of roundish or angular 
cells. These excurrent filaments spread both horizontally and vertically, and their branches 
anastomose into a cellular mass or fleshy membrane, which forms the inner peripheric stratum. 
In young plants a portion of the frond, between the axis and periphery, is hollow, but in 
older ones the cavity is quite filled up with cells. The external surface of the cellular peri- 
phery is clothed with a coat of moniliform filaments gradually developed, and forms what is 
above called the second peripheric stratum. These are found only in fully-grown specimens ; 
they consist of much smaller cells than those of the inner stratum ; they are more strongly 
colored, and I consider them to be connected with fructification. The color is a dark olive. 
The substance is brittle, rigid when dry, and the plant scarcely adheres to the paper. The 
generic name is in memory of the late Prof. Tuomey, of Tuscaloosa.” 


Remarks.—I have no knowledge of this plant, and have simply copied the de- 
scription of Prof. Harvey; Smithsonian Contributions, 1846. 


Famy LEMANEACEA. 


Alge rivulares vel fluviatiles. Thallus e prembryone confervacea enascens, setaceus, subsimplice 
vel fasciculatim ramosus, cavus, nodosus, e cellularum stratis internis et corticatis formatus. Noduli 


plerumque papillarum corona instructi. Polyspore numerose, in seriebus ramosis moniliformibus 


fasciculatim aggregate, sine fecundatione germinantes. 


222 FRESH-WATER ALG&ZH OF THE UNITED STATES. 


Alge growing in streams and rivers. Thallus developing from a confervoid prothalloid filament, 
setaceous, almost simple or fasciculately branched, hollow, nodose, composed of internal and corti- 
cal strata of cells. Nodules generally provided with a corona or papilla. Polyspores numerous, 
fasciculately aggregated in branched moniliform series, germinating without fecundation. 


Genus LEMANEA, Bory. 
Genus unicum. 


The only genus. 


Remarks.—The plants belonging to the genus Lemanea are quite peculiar in 
aspect and habit. ‘They grow exclusively in fresh water, especially frequenting 
streams whose current is rapid, and whose waters are chilled by the mountain air. 
Their frail, tubular, scarcely-branched fronds offer but little resistance to the 
water, whilst their lower end is swollen into a sort of discoid root, which adheres 
firmly to the stones. The frond is mostly blackish or brownish, and is formed of 
two distinct portions or layers, of which the outer or cortical is composed of small 
closely cohering, colored cells; the inner of much larger cells, which have thick 
colorless walls, and are placed so as to leave more or less numerous interspaces. 
In the immature frond there is also a longitudinal central column, besides some 
slender many-jointed filaments, passing obliquely through the cavity, but as final 
development takes place these seem to disappear. The mature frond is alternately 
contracted and expanded throughout its length. In the narrow portions the inner 
tissue often blocks up the tube entirely, whilst the dilated parts are loosely filled 
with the spores, which are produced within the frond. The spores themselves are 
oval, thickish-walled cells, whose endochrome changes from greenish to a very 
decided yellow during the process of maturing. They are joined together to form 
rows or series, which are not simple, but are very much branched, so that from a 
central basal row arises a complex bush-like mass (pl. 20, fig. 4). These spore- 
clusters are always distinct, a number of them existing in each sporangial node of 
the frond. 

Dr. B. Wartmann described, nearly twenty years ago, very fully the way in 
which the spores germinate and develop into the frond. The first step, according 
to this authority, consists in the elongation of the spore and the projection of one 
end, which is soon cut off by the formation of a transverse partition, and consti- 
tutes a new cell. This multiplying in no strikingly peculiar way soon develops 
into a branched confervoid filament. A large number of these filaments are gene- 
rally produced in one place at one time and form a very apparent greenish layer. 
Finally certain cells in branches of these filaments swell up and become very much 
broader than their fellows, undergoing, at the same time, division so rapidly that 
they become very short. By and by they divide also in the direction of their 
breadth, so that instead of a simple series of cells there arises a compound mass. 
This is the beginning of the new frond. At first it is dependent upon the parent 
filament, but soon acquires a root-like process at the base and develops rapidly 
into the complex cartilaginous plant. 


FRESH-WATER ALGA OF THE UNITED STATES. 223 


L. torulosa, (Ror) Ac. 


L. subsimplex, plerumque arcuata, cartilaginea et nonnihil rigida, 1-2 pollices longa; nodulis 


approximatis, papillis applanatis, plerumque 4-6 enormiter verticellatis, vel nonnihil sparsis, 
interdum nonnihil confluentibus ; sporis ovalibus. 


i ae i Bu 14 
Diam.—Sporis. transv. max. yy85y"—yohsy"- 


Syn.—L. torulosa (RorH) Ac. Rasennorst, Flora: Europ. Algarum, Sect. III. p. 411. 


Hab.—In flumine, Kentucky; (Short) Harvey. Pennsylvania; Virginia; New York; New 
Jersey ; Wood. 


Subsimple, mostly arcuate, cartilaginous and somewhat rigid, 1-2 inches long; nodules ap- 
proximate, with their papules applanate, mostly 4-6, irregularly verticillate or somewhat 
scattered, sometimes slightly confluent; spores oval. 


Remarks.—This plant attains a length of about two inches, and grows in masses 
attached to rocks, often forming a sort of turfy covering to them, in rapidly run- 
ning water. In mass it has a grayish or blackish appearance. The filament has 
a grayish groundwork, with a dark band at the position of the nodes, which are 
enlarged artd inclose the spores. The transverse outline of the filament is a very 
irregular circle. I have found this species very abundant in the rapid water of the 
Schuylkill, just above Flat Rock Turinel, on the Reading Railroad, eight or nine 
miles above Philadelphia. Prof. E. D. Cope has sent me specimens collected by 
himself. in swift streams in Western Virginia, and Mr. Austin has obtained it in 
similar situations in Northern New Jersey. Mr. Austin has also sent me specimens 
collected in Canada West. 


L. fluviatilis, Aa. 


L. simplex vel parce ramosa, quatuor uncias longa (interdum spithamea?), recta vel subrecta ; 
nodulis subremotis, papillis verticillatis magnis obssesis; sporis globosis vel subellipticis: 


Diam.—Spor. 73.o5n"—12s50" 
Syn.—L. fluviatilis, AGARDH. RaBENnorst, Flora Europ. Algarum, Sect. III. p. 411. 
Hab.—In rivulis, Alabama; T. M. Peters. 


Simple or sparsely branched, 4 inches long (sometimes growing of a span length ?), straight or 
nearly so; nodules rather distant, papilla verticillate, large, prominent. 


Remarks.—The only specimens I havé seen of this species were sent me by 
Prof. Ravenel. This plant is larger and heavier than L. torulosa, from which it is 
also readily distinguished by its very large prominent papille. These are in 
slightly irregular whorls of three or more. The spores vary in shape from that 
of a globe to that of a somewhat four-sided ellipse; in the latter case being some- 
times nearly twice as long as broad. Prof. Rabenhorst speaks of the plant attain- 
ing the length of a span. I have never seen it over four inches, 


L. catenata, Krz. 
L. ad uncias 5 longa, regulariter constricta, simplex, compressa, arcuata, in massa obscure 
violacea; papillis nullis; sporis enormiter ovalibus vel subglobosis. 
Diam —Spor. transv. max. qig5q” = -001”. 4 
Syn.—L. catenata, Kiirzinc. RABENHORST, Flora Europ. Algarum, See. III. p. 412. 


224 FRESH-WATER ALG OF THE UNITED STATES. 


Hab.—In rivulis frigidis montanis Diamond Range, Rocky Mountains ; (Sereno Watson). 


About 5 inches long, regularly constricted, simple, compressed, arcuate, in mass obscure violet; 
papules wanting; spores irregularly oval or subglobose. 


Remarks.—I have received specimens of the plant from which the above diag- 
nosis was drawn, from Mr. Sereno Watson, labelled ‘ Mountain stream, Diamond 
Range, altitude 6500 feet.” In the dried state they are closely interwoven into a 
dark purple, rigid thin mass. When soaked out they preserve the same color in 
mass, but each individual stem has a general light yellowish, neutral ground tint, 
. with dark-purplish or greenish-black bands at regular intervals. At the position 
of these bands the filament is nearly round and contracted, whilst between them it 
is compressed and enlarged. The spores are placed, not at the swelling, but at 
the constrictions, corresponding to the dark rings in position. They are quite 
irregular in shape, and of a faint yellow tint. The filaments between the little 
knots of spores appear to be hollow. Their walls are everywhere very thin when 
compared with ZL. torulosa, hence they are more flaccid. ‘The species agrees in 
every respect with Prof. Rabenhorst’s diagnosis of L. catenata, K1z., a native of 
cold mountain streams of Germany and Switzerland. I regret, however, very 

reatly that I have had no opportunity of comparison with European specimens, or 
a fuller description. 


SUPPLEMENT. 


Tue following species, of which the author has not seen specimens, were inad- 
vertently omitted from their proper places in the monograph. ‘They are all con- 
tained in the Nereig Boreali-Americana of Prof. Harvey. The following descrip- 
tions and remarks are simply copied from the work mentioned. 


Tetraspora lacunosa, Cuavy. 
Frond at first tubular, then flat, or irregularly lobed, membranaceo-gelatinous, pale-green, every- 
where pierced with roundish holes of various sizes. Chauv. Alg. Norm. Breb. Alg. Fal. p. 
li,é 1. Kiitz. Sp. Alg. p. 224. TF. Godeyi, De Breb. Kiitz. Tab. Phyc~t. 80, f. 3. T. 
perforata, Bailey, IS. , 


Hab.—In fresh-water streams. Abundant near Westpoint, Prof. Bailey; Providence, Rhode 
Island, Mr. Olney. (v. s. in Herb. T.C.D.) 


Frond at first fannel-shaped,: afterwards splitting open, and then flat, expanding upwards and 
irregularly lobed, everywhere pierced with roundish holes of various sizes, large and small 
intermixed. These holes increase in size and numbers with age, and thus at last the frond 
becomes an open network. The substance is very gelatinous, but rather firmer than in some 
other species of the genus. The color is a pale green; and the hyaline gelatinous membrane 
is filled with roundish granules set in fours. 


Kiitzing’s figure of 7. Godeyi answers well to our plant. I have not seen any 
authentic specimens of 7. /acwnosa, which is referred by Kiitzing to his 7. lubrica, 
var. 3., but the description given of it applies to the American plant. When care- 
fully dried, it forms a very pretty object for the herbarium. (Chlorospermee, p. 
61.) (Harvey, p. 61.) 


Nostoc (Hormosiphon) arcticum, BERs. 
Fronds foliaceous, variously plaited, green or brownish; filaments at length (their gelatinous 
envelope being dissolved) free. Berk. in Proc. Lin. Soc. fide An. Nat. Hist. 2d Ser. vol. 
10, p. 302. 


Hab.—On the naked soil, in boggy ground. Assistance Bay, lat. 75° 40'N. Dr. Sutherland. (v.s.) 


“ Fronds foliaceous, variously plicate, sometimes contracted into a little ball. Gelatinous 
envelope at length effused ; connecting cells at first solitary, then three together; threads, 
which are nearly twice as thick as in N. commune, breaking up at the connecting cells, so as 
to form new threads, each terminated with a single large cell, the central cell becoming free.” 


Berk. 1. ¢. 


“Tt grows,” says Dr. Sutherland, “upon the soft and almost boggy slopes around 


Assistance Bay; and when these slopes become frozen at the close of the season, 
29 October, 1872. ( 225 ) 


226 SUPPLEMENT. 


the plant lying upon the surface in irregularly plicated “masses becomes loosened, 
and if it is not at once covered with snow, which is not always the case, the wind 
carries it about in all directions. Sometimes it is blown out to sea, where one can 
pick it up on the surface of the ice, over a depth of probably one hundred fathoms. 
It has been found at a distance of two miles from the land, where the wind had 
carried it, At this distance from the land it was infested with Podure, and 1. 
accounted for this fact by presuming that the insects of the previous year had de- 
posited their ova in the plant upon the land, where also the same species could be 
seen in myriads upon the little purling rivulets, at the side of which the Nostoc 
was very abundant.” At p. 205 of his Journal, Dr. Sutherland further mentions 
having tried it as an article of food, and found it preferable to the Tripe de Roche 
of the arctic hunters. Its nutritive qualities are probably equal to those of the 
jelly derived from other Alge. (Chlorospermee, p. 113.) 


Nostoc flagelliforme, Brrx. and Curt. 
Terrestrial; frond cartilaginous, linear, very narrow, compressed and often channelled, much 
branched, irregularly dichotomous; branches solid, densely filled with moniliform curved 
threads. Berk. and Curt. No. 3809. 


Hab.—On naked aluminous soil, at San Pedro, Texas, Mr. Charles Wright. (v.s.) 


Fronds several inches in length, half a line in diameter, lying prostrate on the surface of the 
soil, much branched in an irregularly dichotomous manner; branches exactly linear, com- 
pressed, often channelled on one or both sides, thinned in the middle and jincrassated to the 
edge. Substance firm and elastic, cartilaginous, solid, densely filled with moniliform, curved or 
curled, interlaced threads, which are set longitudinally in the frond, and lie nearly parallel to 
each other. Color dark olive. 


A very curious and most distinctly marked species, differing from others of this 
genus, much in the same manner that Chetophora endiviefolia does from the ordi- 
nary globose forms of Chetophora. (Chlorospermee, p. 115.) 


Nostoc microscopicum, Carm. 
Fronds densely aggregated, very minute, giobose or oblong, immersed in a blackish crust; fila- 
ments few. Carm. in Hook. Brit. Fl. 2, p.399. Harv. Man. Ed. 1, p. 184. N. muscorum, 
Hass. Br. Fr. Wat. Alg. p. 292, t. 14, fig. 4. 


Hab.—‘‘ Stones in a small stream, Baffin’s Bay,” Dr. Sutherland, fide Prof. Dickie. 


I have not seen American specimens. In Britain this species grows among 
mosses on exposed calcareous rocks, but not in water. The above specific charac- 
ter is taken from the British plant. The fronds are rarely more than the tenth of 


an inch in diameter, and contain two or three beaded filaments lying in a copious 
transparent jelly. (Chlorospermew, p. 115.) 


Genus Hyprurus, Ac. 


Frond fixed at base, cylindrical or compressed, elongated, branched, gelatinous. Structure: 
seriated, but separate, cellules, filled with bright-green endochrome, inclosed in gelatinous parallel 
tubes, ranged longitudinally in the frond, and surrounded by a common gelatinous envelope. 


SUPPLEMENT. 227 


Of this genus several species have been described by authors, all having a close 
resemblance to each other, and all very variable in ramification. Indeed it is 
almost impossible to fix characters by which they can be permanently kept apart ; 
and instead of adding another specific name to the already too numerous list, I 
prefer to consider the American specimens received as constituting a luxuriant 
variety of the best known of the established species. All previously recorded 
species or varieties of these plants are natives of rapid rivers and streams in 
various parts of Europe. (Chlorospermew, p. 118.) 


Hydrurus penicillatus, var. occidentalis, Harv. 
Frond very long (1-2 feet or more), much branched; branches very irregular, scattered or 
crowded, wormlike, tapering to a fine point, naked or clothed with feathery villous ramuli; 
cells ellipsoidal or pear-shaped, twice as long as their diameter. 


Hab.—On the rocky bottom of rivers and streams, in a strong current. Santa Fe, New Mexico, 
Mr. Fendler, February to April, 1847. (V.8. in Herb. T.C.D.) 


Fronds attached at base, one or two feet long, from one to four lines in diameter, very much 
and irregularly branched ; branches scattered or crowded, simple or divided, a foot or more 
in length, attenuated to a fine point, sometimes smooth and naked, but generally densely 
clothed with slender, villous ramenta, spreading to all sides. The gelatinous tubes or sheaths 
in which the cells are seriated are very obvious, and lie close together in longitudinal, paral- 
lel strata. The cells are of large size, bright-green color, and variable shape; some are twice 
as long as others. ‘ 


This I had at first supposed to be a new species, but now regard it as a very 
gigantic state of H. penicillatus, Ag., which under various forms and of various 
sizes is common in alpine streams in Europe. I fear characters derived from the 
shape and size of the cellules are not more to be depended upon than are those 
taken from the ramification. (Chlorospermee, p. 118.) 


Draparnaldia opposita, Ac. 

Frond vaguely much branched ; joints of the main filament as long as broad, or shorter; pencils 
of ramuli mostly opposite, densely set, lanceolate-acuminate in outline, plumose, bi-tripinnate, 
the apices much attenuated. Ag. Syst. p.59. Kiitz. Sp. Alg. 357. Lyngb. Hyd. Dan. tab. 
65, fig. A. Batrachospermum Americanum, Schweinitz. 


Hab.—In clear streams. New York, Professor Bailey. New Jersey, Mr. Jackson. (v.s.) 


Frond 2-3 inches long, gelatinous, capillary, irregularly much branched; the branches patent, 
lateral, more or less divided, and set with lesser ramuli. Main filaments with short articula- 
tions, as long as their breadth, or shorter, transversely banded. At every two or three nodes 
and sometimes at every node a pair of opposite penicillato-multifid ramuli are thrown off. 
These are bright green, ovato-lanceolate in outline, much acuminated and twice or thrice pin- 
nate, their pinnules somewhat constricted at the nodes, and tapering at the apex into long, 
needle-like, hyaline points. Their cells are commonly nucleated and filled with endochrome. 


Whether this be permanently distinguishable from D. glomerata is doubtful. It 
has externally the aspect of that species, but its microscopic characters are nearer 


those of D. plumosa. 


GEOGRAPHICAL LIST OF SPECIES. 


Cuass PHY COCHROMOPHYCE. 


Orper CYSTIPHORA. 


Family CHROOCOCCACEA. 
Chroococcus 

refractus, Wood. Hub. near Philadelphia. 

Hab. near Philadelphia. 


Hab. Benton Springs, Owen 
Co., California. 


multicoloratus, Wood 
thermophilus, Wood. 


Gloeocapsa 


| Hal: Prilactelphra 


sparsa, Wood. 


Cezlospherium 


dubium, Griin. Hab. near Philadelphia. 


Merismopedia 
Hab. near Philadelphia. 


Hab. Spring Mills, Montgomery 
Co., Pa. 


nova, Wood. 
convoluta, Bréb. 


OrpER NEMATOGENEZ. 
Family OSCILLARIACEA. 
Oscillaria 
ehlorina, Ktz. Hab. near Philadelphia. 
Hab. New York. 
Hab. Northern U. States. 


Schuylkill 


corium, Ag. 
decorticans, Gener. 
Frohlichii, Kuz. 


Hab. River, near 


Philadelphia. 

Hab. near Philadelphia. 

Hab. near Camden, New Jersey. 
Hab. West Point, New York. 
Hub. near Philadelphia. 

Hab. New York; Philadelphia. 
Rhode Island; New York; 
Virginia. 

Hab. Warm Springs of Washita. 


imperator, Wood. 
limosa, Ag. 
muscorum, Ag. 
neglecta, Wood, 
nigra, Vauch. 
tenuis, Ag. Hab. 


tenuissima, Ag. 


Chthonoblastus 
repens, Kitz. Hab. New York; Massachusetts ; 


Rhode Island. 


Lyngbya 
bicolor, Wood. Hab. Schuylkill River, near Phila- 


delphia. 


muralis, Ag. Hab. Whale Fish Islands, Davis 


Straits, British America. 


Family NOSTOCHACE/. 


Sub-Family Nosrocez. 
Nostoc 
Austinii, Wood. 


alpinum, Kitz. Hab. Alleghany Mountains ; Clover 
Mts., Nevada; Baffin’s Bay, British America. 


Hab. Catoosa Springs, Georgia. 


Hab. New Jersey. 


calcicola, Ag. 


Hab. Benton Springs, Owen 
Co., California. 


calidarium, Wood. 


Hab. New Jersey. 

Hab. Kansas. 

Hab. near Philadelphia. 
Hab. New Jersey ; Rio Bravo. 


ceruleum, Lyn. 
Cesatii, Bals. 
comminutum, Kiz. 
commune, Vauch. 
depressum, Wood. é Hab. New Jersey. 
punctatum, Wood. Hab. New Jersey. 
Hab. New ‘Jersey. 
Hab. Maine. 


Hab. Centre Co., Pennsylvania. 


pruniforme, Agh. 
verrucosum, Vauch. 


sphericum, Vauch. 


Sub-Family SPERMOSIREZ, 

Anabzena 
gelatinosa, Wood. Hab. near Philadelphia. 
Hab. near Philadelphia. 
Hab. Round Pond, West Point, 
New York. 


gigantea, Wood. 
flos-aque, Kiz. 


Cylindrospermum 
comatum, Wood. Hab. Niagara, Canada. 
Hab. near Philadelphia. 
Hab. South Carolina. 


Hab. near Philadelphia. 


flexuosum, Rab. 
macrospermum, Kéz. 
minutum, Wood. 


Dolichospermum 


Hab. near Philadelphia. 
Hab. New Jersey. 


polyspermum, Kitz. 
subrigidum, Wood. 


Family RIVULARIACEA, 


Nostochopsis 


lobatus, Wood. Hab. Schuylkill River, near Phila- 


delphia. 


Glolotrichia 


angulosa, Roth. Hab. Hudson River, near West 


Point. 
( 229 ) 


230 


Gloiotrichia 


incrustata, Wood. Hab. Schuylkill River near 


Philadelphia. 


Rivularia 


cartilaginea, Wood. Hab. Northern Michigan. 


Zonotrichia 
Hab. Clear Pond, Adirondack 
Mountains. 
Hab. Cave of the Winds, Niagara. 


ZIab. Cave of the Winds, 
Niagara. 


minutnla, Wood. 


mollis, Wood. 
parcezonata, Wood. 


Dasyactis 


mollis, Wood. Hab. Cass River, Northern Michigan. 


Mastigonema 
Hab. Philadelphia. 


Hab. Alleghany Mountains, Centre 
Co., Pennsylvania. 


elongatum, Wood. 
fertile, Wood. . 


halos, Wood. 


sejunctum, Wood. 


Hab. Stonington, Connecticut. 


Hab. Northern 
Michigan. 


Cass_ River, 


Mastigothrix 
fibrosa, Wood. Hab. near Philadelphia. 
Family SCYTONEMACEA. 
Scytonema 
Austinii, Wood. 


calotrichoides, Atz. 


Hab. Little Falls, New Jersey. 
Hub. South Carolina. 

Hab. Niagara River, Niagara. 
Hab. South Carolina. 

Hub. Cumberland Co., New Jersey. 
Hab. Cumberland Co., New 


cataracta, Wood. 
cortex, Wood. 
dubium, Wood. 


immersum, Wood. 


Jersey. 

Myochrous, Ag. Hab. West of Crow’s Neck, West 
Point. 

»Negelii, Atz. Hab. near Bellefonte, Centre Co., 
Pennsylvania. 


Hab. South Carolina. 
Hab. Aiken, South Carolina. 
Hab. South Carolina. 


Ravenellii, Wood. 
simplice, Wood. 


thermale. 


Tolypothrix 


distorta, Jul. Hab. near Philadelphia; West 


Point, N. Y.; Rhode Island; 
Madison, Wisconsin. 


Family SIROSIPHONACEA. 
Sirosiphon 
Hab. South Carolina. 
Hab. South Carolina. 
Hab. Salem, Massachusetts ; New 
Jersey. 


acervatus, Wood. 
argillaceus, Wood. 
compactus, Ag. 


Crameri, Br. Hab. Mount Tahawus, Adirondack 


Mountains. 


GEOGRAPHICAL LIST OF SPHOCIES. 


Sirosiphon 
guttula, Wood. 


lignicola, Wood. 


Hab. South Carolina. 
Hab. South Carolina. 
neglectus, Wood. Hab. New Jersey. 
Hab. near Hibernia, Florida. 
Hab. Northern New Jersey. 


Hab. South Carolina. 


pellucidulus, Wood. 
pulvinatus. 
scytenematoides, Wood. 


Stigonema 


Ravenellii, Berkeley. Hab. Lookout Mountains, 


Georgia. 


Ciass CHLOROPHYLLACES. 
Orver COCCOPHYCEA 
Family PALMELLACEA. 
Pleurococcus 


Hab. Boiling Springs, near Belle- 
fonte, Centre Co., Pennsylvania. 


pulvereus, Wood. 


seriatus, Wood. Hab. New Jersey. 


Palmella 
dura, Wood. 
hyalina, Lyn. 


Hab. near Philadelphia. 
Hab. From Rhode Island to 
Wisconsin. 


Jesenii, Wood. Hab. near Philadelphia. 


Pagerogalla 
stellio, Wood. Hab. Bear Meadows, Alleghany 
Mountains, Centre Co., Penn- 


sylvania. 


Tetraspora 
bullosa, Roth. . 
gelatinosa, Roth. 


Hab. Salem, North Carolina. 
Hab. Salem, North Carolina; 
Newburgh, New York. 


lubrica, Roth. Hab. Northern Atlantic States. 


Dictyospherium 


pulchellum, Wood. Hab. near Philadelphia. 


Rhaphidium 
falcatum. Hab. near Philadelphia. 
polymorphum, Fr. Hab. near Philadelphia. 


Family PROTOCOCCACEA. 


Polyedrium 


enorme, Ralfs. Hab. Florida. 


Scenedesmus 
acutus, Meyen. Hab. Rhode Island; near Phila- 
delphia. 
Hab. Georgia; Rhode Island. 
Hub. near Philadelphia. 
Hab. Rhode Island; Penn- 
sylvania. 
Hab. near Thiladelphia 


obtusus, Meyen. 
polymorphus, Wood. 
quadricauda, Turp. 


rotundatus, Wood. 


GEOGRAPHICAL LIST OF SPECIES. 


Hydrodictyon 
utriculatum, Roth. Hab. West Point and Wee- 
hawken, New York; Mexi- 
can Boundary; Pennsyl- 


. vania ; New Jersey. 
Pediastrum 


Boryanum, Jur. Hab. Rhode Island; Pennsyl- 
vania; Georgia; Florida. 
Hab. South Carolina; 
Georgia; Rhode Island. 
Hab. South Carolina ; Rhode Island. 
Ehrenbergii, Corda. Hab. Rhode Island; South 
Carolina; Georgia; Florida. 
Hab. Rhode Island. 

Hab. Rhode Island. 


constrictum, Hassall. 


duodenarius. 


pertusum, Kez. 


Selenza, Kitz. 


Family VOLVOCINEA. 
Chlamydococcus 


nivalis. Jab. Greenland ; Rocky Mountains. 


Volvox 


globator, Zinn. Hab. United States. 


OrpER ZYGOPHYCEA. 


Family DESMIDIACEA. 
Palmogloea 


clepsydra, Wood. Hab. near Philadelphia. 


Penium 
Hab. South Carolina. 
Hab. South Carolina. 


Hab. Pennsylvania; New York; 
Georgia. 


Brébissonii, Men. 
closterioides, Ralfs. 
Digitus, Ehrb. 


Hab. near Grahamsville, South 
Carolina. 


Hab. Florida. 
Hab. Rhode Island. 
margaritaceum, Lhrb. Hab. Rhode Island. 


Hab. Rhode Island; South Caro- 
lina; Georgia, 


interruptum, Bréb. 


Jenneri, Ralfs. 
lamellosum, Bréb. 


minutum, Cleve. 


Closterium 
Hab. South Carolina; Georgia; 
Florida. 
Hab. West Point, New York; 
Piovidence, Rhode Island. 
Hab. Rhode Island ; New Hamp- 
shire; Pennsylvania. 
Hab. Northumberland Co., 
Pennsylvania. 
Hab. New York. 
Hab. Georgia; Florida; Pennsyl- 
vania; Rhode Island. 
Hab. Philadelphia. 


acerosum, Schr. 
Amblyonema, Ehrb. 
angustatum, Kitz. 
areolatum, I ood. 


Cucumis, Ehrb. 
Diane, Ehrb. 


Ehrenbergii, Men. 
Jennerii, Ralfs. 


juncidum, Ralfs. ab. Saco Lake, New Hampshire ; 


South Carolina. 


Closterium 


Leibleinii, Kitz. 


lineatum, Fhrb. 
Lunula, Miller. 


maximum, var. 
moniliferum, Bory. 
parvulum, Neg. 
rostratum, Ehrb. 
setaceum, Lhrb. 


striolatum, Ehrb. 
Venus, Ktz. 


Tetmemorus 


Brébissonii, Men. 
giganteus, Wood. 
granulatus, Bréb. 


levis, Ktz. 


Pleurotzenium 


Baculum, Bréd. 
breve, Wood. 
clavatum, Ktz. 
constrictum, Bailey. 


erenulatum, Ehrb. 


gracile, Rab. 
hirsutum, Bailey. 


nodosum, Bailey. 


Trabecula, Ehrb. 


undulatum, Bailey. 
verrucosum, Bailey. 


231 


Hab. Georgia; South Carolina ; 
Pennsylvania. 


Hab. Pennsylvania. 


Hab. South Carolina; Florida ; 
Georgia; Pennsylvania. 


Hab. Pennsylvania. 

Hab. Georgia; Rhode Island. 
Hab. near Philadelphia. 
Hab. near Philadelphia. 


Hab. Stonington, Connecticut ; 
Providence, Rhode Island ; 
Pennsylvania; Georgia; 
Florida. 

Hab. Centre Co., Pennsylvania. 

JTab. South Carolina. 


Hab, Atlantic States. 
Hab. Centre Co., Pennsylvania. 


#Tab. Rhode Island; Pennsyl- 
vania; South Carolina. 


Hab. near Philadelphia. 


Hab. Georgia. 
Hab. District of Columbia. 
Hab. South Carolina; Georgia. 
Hab. Rhode Island. 
Hab. Rhode Island; New Jer- 
sey; Pennsylvania; South 
Carolina ; Georgia ; Florida. 
Hab. Florida. 
Hab. United States. 
Hab. South Carolina; Georgia ; 
Florida; Penusylvania. 
Hab. Pennsylvania; New Jer- 
sey ; South Carolina; 

Georgia ; Florida. 
Hab. Florida. 
Hab. Rhode Island. 


ITab. Rhode Idina 


Triploceras 

Hab. Rhode Island; New Jersey ; 
New Lampshire ; Florida; Georgia. 
Hab. with the last. 


gracile, Bailey. 


verticillatum, Bailey. 


Spirotznia 
bryophila, Bréb. 
condensata, Bréb. 


Hab. near Philadelphia. 


Hab. Pennsylvania; Rhode 
Island; Florida. 


Bar busina 
Brébissonii, Kitz. Hab. Florida; Georgia; South 


Carolina; Rhode Island. 
Didymoprium 
Grevillii, Kéz. Hab, Pennsylvania; South Caro- 


lina ; Georgia, 


232 GEOGRAPHICAL LIST OF SPECIES. 


Sphzrozosma 
excavatum, Ralfs. 


pulchrrwm, Bailey. 


Hab. Rhode Island; South 
Carolina ; Georgia; Florida. 
Hab. New York; New Jersey. 


serratum, Bailey. Hab. South Carolina; Georgia ; 


Hyalotheca 


Florida. 


disilliens, Smith. Hab. Rhode Island; Pennsyl- 
yvania; South Carolina; Florida. 


mucosa, Mert. 


Desmidium 
aptogonium, Bréb. 
quadrangulatum, Kiz. 
Swartzii, Ag. 


Aptogonium 


Hab. Rhode Island. 


Hab. South Carolina; Georgia. 
Hab. South Carolina. 
Hab. Atlantic States. 


Baileyi, Ralfs. Hab, Rhode Island ; New Jersey. 


Cosmarium 
amenum, Bréb. 
bioculatum, Bréb. 
Botrytis, Bory. 
Brébissonii, Men. 


Broomei, Thw. 


celatum, Ralfs. 
commissuralée, Bréb. 


connatum, Bréb. 
crenatum, Ralfs. 


Hab. Florida; Rhode Island. 

Hab. Rhode Island. 

Hab. Pennsylvania. 

Hab. White Mountains, New 

Hampshire. 

Hab. Pennsylvania; Georgia. 

Hab. near Albany, New York; 
South Carolina. 


Hab. White Mountains, New 
Hampshire. 


Hab. Florida. 
Hab. Rhode Island. 


cucumis, Corda. Hab. New Hampshire; Pennsyl- 


depressum, Bailey. 


margaritiferum, Turp. 


Meneghenii, Bréb. 
ornatum, Ralfs. 
ovale, Ralfs. 
pyramidatum, Bréb 


Quimbyii, Wood. 
sublobatum, Bréb. 


suborbiculare, Wood. 


tetropthalmum, Kitz. 
Thwatesii, Ralfs. 
undulatum, Corda. 


Euastrum 
affine, Ralfs. 
ampullaceum, Raifs. 


vania; South Carolina; 
Georgia; Florida. 


Hab. Florida. 


Hab. Pennsylvania; South 
Carolina; Florida; Mexico. 
Hab. Pennsylvania. 
Hab. Rhode Island. 
Hab. Pennsylvania. 


Hab. Pennsylvania ; Georgia; 


Florida.: 


Hab. near Philadelphia. 
Hab. Rhode Island ; Georgia ; 
Florida. 

Hab. Lake Saco, New Hamp- 
shire. 

Hab. New Jersey. 

Hab. Florida. 


Hab. Rhode Island; South 
Carolina. 


Hab. South Carolina; Georgia. 
Hab. South Carolina; Florida. 


Buastrum. 
binale, Turp. Hab. Florida; Pennsylvania; Rhode 
Island. 
circulare, Hassal. Hab. Rhode Island. 
crassum, Bréb. Hab. United States. 
Didelta, Turp. Hab. South Carolina; Georgia ; 
Pennsylvania; Rhode Island. 
elegans, Bréb. Hab. United States. 
gemmatum, Bréd. Hab. Rhode Island. 
insigne, Ralfs. Hab. Florida; Rhode Island. 
multilobatum, Wood. Hab. Saco Lake, New Hamp- 
; shire. 
oblongum, Greville. Hab. Rhode Island. 


ornatum, Wood. Hab. Saco Lake, New Hampshire. 
Ralfsii, Rabenh. Hab. Sotth Carclina ; New Hamp- 
shire; Rhode Island. 


verrucosum, Khr. Hab. Rhode Island; South 
Carolina ; Georgia; Florida. 


Micrasterias 


Americana, Ehrb. Hab. Florida; South Carolina, 
arcuata, Bailey. Hab. Florida. 


Baileyi, Ralfs. Hab. New York; Rhode Island; 
South Carolina; Florida. 


denticulata, Bréb. Hab. Pennsylvania; Florida. 
disputata, Wood. Hab. Atlantic States. 
expansa, Bailey. Hab. Florida. 


fimbriata, Ralfs. Hab. South Carolina; Florida. 
foliacea, Bailey. Hab.Worden’s Pond, Rhode Island. 


furcata, Ag. Hab, Atlantic States. 
granulata, Wood. Hab. South Carolina. 
Jenneri, Ralfs. Hab. near Philadelphia. 
oscitans, Ralfs. Hab. Florida; Rhode Island. 
papillifera, Bréb. Hab. Florida; Rhode Island. 
pinnatifida, Kiz. Hab. 

quadrata, Bailey. Hab. Florida. 
radiosa, Ag. Hab, Florida. 
ringens, Bailey. Hab. Florida. 
Torreyi, Bailey. Hab. near Princeton, New Jersey. 
truncata, Corda. Hab. Atlantic States. 

Staurastrum 


alternans, Bréb. Hab. Georgia; Florida; Rhode 
Island. 


arachne, Ralfs. Hub. Saco Lake, New Hampshire. 
aristiferum, Ralfs. Hab. Georgia; Rhode Island. 


Cerberus, Bailey. Hab. Florida. 
crenatum, Bailey. Hab. Rhode Island. 
cyrtocerum, var., Bréb. Hab. Florida. 
dejectum, Bréb. Hab. New York; South Caro- 

lina. 


dilatatum, Ehrd. Hab. Southern Atlantic States. 
eustephanum, Ral/fs. Hab. West Point, New York. 


furcigerum, Bréb. Hab. South Carolina; Flor'da; 
Rhode Island, 


GEOGRAPHICAL LIST 


Staurastrum 
gracile, Ralfs. Hab. South Carolina; Georgia; 
Florida; New York; Rhode 


Island. 

Hab. Florida; Rhode Island. 
Hab. Rhode Island. 

Hab. Saco Lake, New Hampshire. 
Hab. Florida. 


Hab. Saco Lake, New 
Hampshire. 

Hab. Saco Lake, New 
Hampshire. 

Hab. South Carolina; Rhode 
Island. 

Hab. Rhode Island ; 
Pennsylvania. 


Hab. Saco Lake, New 
Hampshire. 


Hab. Florida. 

Hab. near Philadelphia. 
Hab. Pennsylvania. 
Hab. South Carolina. 
Hab. America. 


Hab. Georgia; Florida; Rhode 
Island. 


hirsutum, Zhrob. 
Hystrix, Ralfs. 
Lewisii, Wood. 
longispinum, Arch. 


margaritaceum, Ehrb. 
munitum, Wood. 
muticum, Bréb. 
orbiculare, Ehrb. 
paradoxum, Mey. 


polymorphum. 
polytrichum, Per. 
punctulatum, Bréb. 
Ravenellii, Wood. 
senarium, Ehrb. 


tricorne, Zen. 


Xanthidium 
aculeatum, Ehrb. 
Arctiscon, Ehrb. 


armatum, Bréb. 


Hab. near Savannah, Georgia. 
Hub. North America. 


Hab. South Carolina; Florida; 
New Hampshire. 


Hab. America. 
Hab. Southern Atlantic States. 
Hab. America. 


Hab. South Carolina; 
Georgia; Florida; Rhode Island. 


bisenarium, Ehrb. 
cristatum, Bréb. 
coronatum, Efrb. 


fasciculatum, Hhrb. 


Arthrodesmus 
Hab. South Carolina; Georgia; 
Florida; Rhode Island. 


Hab. Georgia; Florida; South 
Carolina; Rhode Island. 


Hab. Florida; Rhode Island. 


Hab. Lake Saco, New 
Hampshire. 


convergens, Elirb. 
Incus, Bréd. 


octocornis, Lhrb. 
quadridens, Wood. 


Family ZYGNEMACEA. 


Spirogyra 
crassa, Kiz. Hab. uear Philadelphia. 
Hab. near Philadelphia. 
Hab. near Philadelphia. 
Hab. near Philadelphia. 
Hab. near Philadelphia. 
Hab. near Philadelphia. 


Tab. Rhode Island ; near Phila- 
delphia. 


decimina, Mil. 
diluta, Wood. 
dubia, Kitz. 
elongata, Berk. 
insignis, Has. 
longata, Vauch. 


30 October, 1872. 


OF SPECIES. 233 


Spirogyra 
majuscula, Kiz. 
nitida, Dill. 

.. protecta, Wood. 


Hab. near Philadelphia. 
Hab. near Philadelphia. 
Hab. near Philadelphia. 
Hab. Hibernia, Florida. 
Hab. near Philadelphia. 
Hab. near Philadelphia. 

Hab. Florida. 
Hab. near Philadelphia. 


parvispora, Wood. 
pulchella, Wood. 
quinina, Ag. 
rivularis, Hassall. 


setiformis, Roth. 


Weberi, Kitz. Hab. near Philadelphia. 
Zygnema 
insigne, Hassal. Hab. Rhode Island; near Phila- 
delphia. 
cruciatum, Vauch. Hab. Virginia; Florida; 
Northern States. 
Sirogonium 


retroversum, Wood. Hab. near Philadelphia. 


Mesocarpus 


scalaris, Hassall. 
parvulus, Hassall. 


Hab. near Philadelphia. 
Hab. Rhode Island. 


Pleurocarpus 


Hab. New York; Rhode Island; 
Michigan; Wisconsin. 


mirabilis, Braun. 


‘Orprr SIPHOPHYCE.A. 


Family HYDROGASTREA. 
Hydrogastrum 


granulatum, Linn. Hab. Delaware. 


Family VAUCHERIACEA. 

Vaucheria 
aversa, Hassall. Hab. near Philadelphia. 
Hab. near Philadelphia. 
Hab. Texas. 


Hab. New York; Maine; Vir- 
ginia; North Carolina. 

Hab. New York; Maine; Virginia ; 
North Carolina. 


geminata, Vauch. 
polymorpha, Wood. 


sessilis, Vauch. 


velutina, Ag. 


Orper NEMATOPHYCEA. 


Family ULVACEA. 
Protoderma 


viride, Kiz. Hab. Philadelphia. 


Ulva 
merismopedioides, Wood. Hab. Diamond 
Range, Rocky Mountains. 
Enteromorpha 
Hab. Hudson River; Narra- 
gansett Bay. 


intestinalis, Linn. 


Schizomeris 


Leibleinii, Kéz. Hab. near Philadelphia. 


234 


Family CONFERVACEA. 
Conferva. 
Hab. United States. 
Cladophora 


brachystelecha, Rab. 
fracta, Dill. 


Hab. near Philadelphia. 


Hab. Pennsylvania; New York ; 
Rhode Island. 


Hab. Lakes Ontario, Erie, 
Huron, and Michigan. 


glomerata, Linn. 


Family GDOGONIACEA. 

Androgynia ‘ 

echinata, Wood. 
Huntii, Wood. 

mirabilis, Wood. 


Hab. Florida. 
Hab. near Philadelphia. 


Hab. near Philadelphia. 


multispora, Wood. Hab. near Philadelphia. 
Pringsheimia 
inequalis, Wood. Hab. near Philadelphia. 


Bulbochete 
Canbyii, Wood. 
dumosa, Wood. 


Hab. Hibernia, Florida. 
Hab. near Philadelphia. 


ignota, Wood. Hab. near Philadelphia. 


Family CHROOLEPIDEA. 
Chroolepus 


Hab. New York; New Jersey ; 
Texas. 


aureum, Ktz. 


Bulbotrichia 


albida, Wood. Hab. Northern New Jersey. 


Family CHHTOPHORACEA. 
Stigeoclonium. 
Hab. Eastern United States. 
Draparnaldia 


Billingsii, Wood. 
glomerata, Vauch. 


Hab. near Philadelphia. 
Hab. Rhode Island. 


mnmaxima, var., Wood. Hab. near Philadelphia. 


GEOGRAPHICAL LIST OF SPECIES. 


Drapernaldia 


plumosa, Vauch. Hub. near Philadelphia. 


Chztophora 
Hab. Eastern United States. 


Hab. Rhode Island; South 
Carolina. 


elegans, Roth. 
endiviefolia, Roth. 


Pilinia 


diluta, Wood. Hab. Centre County, Pennsylvania. 


Coleocheete. 
Hab. Eastern United States. 


Aphanochete 


repens, Braun. Hab. near Philadelphia. 


Ciass RHODOPHYCEZ:. 
Family PORPHYRACEA. 
Porphrydium 
Hab. New York. 
Hab. Texas. 


a 


eruentum, Ag. 


magnificum, Wood. 


Family CHANTRANSIACER. 
Chantransia 
expansa, Wood. Hab. near Philadelphia. 


macrospora, Wood. Hab. South Carolina. 


Family BATRACHOSPERMACEA. 
Batrachospermum 
Hab. Eastern United States. 
Hab. Uiutah Mountains, Nevada. 


moniliforme, Roth. 
vagum, Roth. 


Tuomeya 
fluviatilis, Harv. Hab. Alabama; Virginia. 
Family LEMANEACEA. 
Lemanea 


catenata, Kiz. Hab, Diamond Range, Rocky 


Mountains. 

Hab. Alabama. 

Hab. Virginia ; Kentucky ; Penn- 
sylvania; New Jersey. 


fluviatilis, Ag. 
torulosa, Roth. 


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Microscopical 


237 


Candolle, See De Candolle. 


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Ibid., 1858, p. 237. 

On specific character, Fecundation, and abnormal de- 
velopment in Gidogonium. Ibid., 1857, p. 29. 


Carus (Carl Gustav). 

Beitrag zur Geschichte der unter Wasser an verschie- 
denen Thierkirpern sich erzeugenden Schimmel- 
oder Algengattung. Nova Acta Acad. Ces. Leopold.- 
Car. Natur Cur. Bd. xi., Bonn, 1823. 


Caspary (Robert). 

Vermehrungsweise von Pediastrum ellipticum. 
Botanishe Zeitung, viii., 1850. 

Deseription of a new British Alga belonging to the 
genus Schizosiphon. 
Annals of Natural History, vi., 1850. 

Ueber die Zoosporen der Gattung Chroolepus. Regens- 
burg Flora, 1857. Berlin Botanische Zeitung, 1857. 


The Zoospores of Chroolepus. Quarterly Journal of 
Microscopical Science, July, 1859. Annal. Scien. 
Natur. (Bot.), vol. ix., 1858. (Translated from Re- 
gensburg Flora). 


Cesati (Vincenzo barone). 


Ueber die Vermehrung von Hydrodictyon utriculatum 
Roth. Hedwigia, 1852. 


Chauvin (Frangois Joseph). 
Observations microscopique sur la Conferva zonata. 
Mémoires Société Linnéenne de Normandie, 1826-7. 


Observations microscopique sur la mode de reproduc- 
tion de la Conferva rivularis. Sessions des Con- 
grés scientifique de France, 1833. 

Examen comparatif des Hydrophytes non articulées de 
la France et de l’Angleterre. Ibid., 183. 


Recherches sur Vorganisation, la fructifieation et la 
classification de plusieurs genres d’algues, avec la 
description de quelque espéces inédites. Caen, 1£42. 


Cienkowski (L.). 
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Die Pseudogonidien. Pringsheim’s Jahrbuch, Bd. i., 
1858, p. 370. 

Rhizidium Conferve glomerate, 
1857. 


Cleve (P. T.). 

Bidrag till kinnedomen om Sveriges sitvattensalger 
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Om de Svenska arterna af Sligtet Vancheria, De Cand. 
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Forsok till en monografi éfver di Svenska arterna af 
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lakttagelser dfver den hvilande CSdogonium (Cidogo- 
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1864. Translated in Microscopic Journal. 


Botanische Zeitung, 1856. 
Bota- 


Botanische Zeitung, 


238 


Cohn (Ferdinand Julius). 

Zur Lehre vom Wachsthum der Pflanzenzelle. 
Cas. Leopold. Nova Acta, xxii., 1847. 

Nachtrage zur Naturgeschichte des Protococcus nivalis 
Ktz. Ibid., xxii., 1847. 

Ueber die Entwickelungsgeschichte der Pflanzenzelle. 
Uebersicht der Schlesischen Gesellschaft fiir vaiter- 
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Ueber blutaihnliche Farbungen durch mikroskopische 
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and Kolliker’s Zeitschrift fiir wissenschiftliche 
Zoologie, vol. iii., 1852. 

Ueber Keimung der Zygnemeen. Uebersicht_ der 
Schles. Gesell. fiir viterl. Cultur, 1852. 

Ueber Protococcus crustaceus Ktz. Hedwigia, 1851. 

Untersuchungen tiber die Entwickelungsgeschichte der 
mikroskopischen Algen und Pilze. Nova Acta 
Akad. Ces. Leopold., xxiv., 1854. Micros. Soc. 
Journ., iii., 1855. 

Ueber die Fortpflanzung von Spheroplea annulina. 
Monatsbericht der k. Preus. Akad. Wissensch. zu 
Berlin, 1855. Ann. and Mag. Nat. Hist., 1856. 
Ann. Sci., Natur. (Bot.), v., 1856. 

Ueber das Geschlecht der Algen. Uebersicht der 
Schles. Gesell. vaterl. Cultur., 1855. Report of 
the British Association for the Advancement of 
Science, 1855. 

Beobachtungen iiber den Bau und die Fortpflanzung 
von Volvox globator. Uebers. Schl. Gesell. vaterl. 
Cultur., 1856. Annals and Magaz. Nat. Hist., 1557. 
Ann. Sci. Natur. (Bot.), 1856. Comptes Rendus, 
xliii. Micros. Soc. Journ., 1857. 

Ueber einige neue Algen Schlesiens. Jahresbericht 
des naturwissen. Vereins zu Breslau, 1857. 

Ueber lebendige Organismen in Trinkwasser. 
1853. 


Acad. 


Ibid., 


Ueber contractile und irritable Gewebe der Pflanzen. 
Ibid., 1860. 

Contractile Gewebe im Pflanzenreiche. Ibid., 1861. 
(Translated) Annals and Mag. Nat. Hist., xi., 1863. 
Ueber das Verhiltniss der Zellen in den niederen 

Pflanzen und Thieren, Ibid., 1861. 

Ueber rothen Schnee. Ibid., 1861. 

Ueber die Algen des Carlsbader Sprudels und deren 
fo an der Bildung des Sprudelsinters. Ibid., 
1862. 

Ueber die Verbreitung der Algen, insbesondere in 
den Meerens Europa’s. Ibid., 1862. 

Verhalten der griinen mikroskopischen Pflanzen und 
Thiere zum Lichte. Ibid., 1863. Microscop. 
Journ., N. S., vol. vii. 

Beitrage zur Physiologie der Phycochromaceen und 
Florideen. Schultzes Archive fiir Mikrosc. Ana- 
tomie, 1867. 

Ueber Chlamydomonas marina, Cohn. Hedwigia, 1865. 

Comelli (Francesco). 


Intornuo alle alghe microscopiche del Dr. B. Biasoletto 
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Corda (August Karl Joseph), 


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Die Algen. Sturm’s Deutschland Flora, 2e Abthei- 
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Corti (Bonaventura). 


Osservazioni microscopische sulla Tremella. 


ail Lucca, 


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239 


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Influence de la lumiére artificielle sur le Spirogyra 
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Influence de la lumiére sur le movement des Chlamedo- 
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Jahrb. xvii., p. 55. 


Flotow (Julius von). 


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Ueber die Algengattungen Pandorina, Gonium, und Ra- 
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Pars I., Plante Homone- 


Gaebel (E.). 
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Gaillon (Benjamin). 

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Apergu d’histoire naturelle et observations sur les 
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240 


Glurup. 
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Bonn, Bd. xv., 1831. 


Goppert (Heinrich Robert). 
Bemerkungen iiber das Vorkommen von Pflanzen in 
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Wiegman’s Archives, 1837. 


G6ppert (Heinrich Robert) und Ferdinand Julius 
Cohn. 


Ueber die Algen Schlesiens. Uebersicht der Arbeiten 
und Verinderungen der Schlesischen Gesellschaft 
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Goodsir (John). 
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Goldfish. Annals and Mag. Nat. Hist., vol. ix., 
1842, p. 333. 


Gravenhorst (Johann Ludwig Christian). 


Einiges aus des Infusorienwelt. Nova Acta, Bonn, 
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Gray (John Edward). 
On the arrangement of the Families and the Genera of 


Chlorospermous Alga. Annals and Mag. Nat. 
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Greville (Robert Kaye). 


Scottish Cryptogamiec Flora. Edinburgh, 1823-29. 


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Micrographiec Dictionary, Ed. 2. London, 1860. 


Grunow (A.). 


Specimen Flore Cryptogame Septeminsularem Alga. 
Abhandlungen des zoolog.-botanischen Vereins, 1861. 


Die Desmidaceen und Pediastreen einiger Osterrei- 
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Ueber neue oder ungeniigend gekannte Algen. 
1860--61-62. 


Ueber die in Rabenhorsts Decaden ausgegebenden 
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Ibid., 


Hannover (Adolph). 

Ueber eine contagiése Confervenbildung auf dem Was- 
sersalamander. Archiv fiir Anatomie, Physiologie, 
und wissensch. Medecin. (J. Miiller), 1839. 

Fernere Erliuterung der contagiédsen Confervenbildung 
auf Fréschen und Wassersalamandern. _Ibid., 1840. 


Hartig (Theodore). 
Ueber die Funktionen des Zellkerns. 
Zeitung, xii., 1854. 
Ueber das Verhalten des Zellkerns bei der Zellen- 
theilung. Ibid., 1854. 


Beitrage zur Entwickelungsgeschichteder Pflanzenzelle. 
Botanische Zeitung, 1855. 

Ueber die Conjugation der Spirogyren. 
Flora. 


Botanische 


Regensburg, 


Harvey (William Henry). 


Manual of the British Algz. London, 1844, 


BIBLIOGRAPHY. 


Harvey (William Henry).— Continued. 

Index Generum Algarum. A Systematic Catalogue of 
all the Genera, Marine and Fresh-water. London, 
1860. 

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Hassal (Arthur Hill). 

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Observations on a new group (Vesiculasperme), genus 
(Vesiculifera), and subgenus (Vesiculifera com- 
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of species mostly New. Ibid., 1842. 


Observations on the growth, reproduction, and species 
of the branched Fresh-water Conferve, mostly new, 
with observations on some of the genera. Ibid., 
1843. 


Observations on some points in the anatomy and phy- 
siology of the Fresh-water Alge. Ibid., 1848. 

Observations on the genus Mougeotia, or two new genera 
of Fresh-water Alge, and on Tyndaridea, with de- 
scriptions of species. Ibid., 1843. 

Observations on the growth and reproduction of Entero- 


morpha intestinalis. Proceedings of the Linnzan 
Society of London, 1849. 

Essay on the distribution, vitality, structure, modes of 
growth and reproduction, and uses of the Fresh- 
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A History of the British Fresh-water Algz. 
100 plates. London, 1845. 


2 vols., 


Hawlett (Frederick). 


On the structure and circulation of Nitella translucens. 
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Hazslinkszky (Friedrich). 

Die Algen Flora Ungarns und seiner Bundeslinder. 
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1868. i 


Hedwig (Romanus Adolf). 
Tremella Nostoch. Commentatio. Lipsia, 1798. 
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Hermann (Johann). 


Botrydium argillaceum Wallr., ob Alge oder Flechte. 
Regensburg Flora, 1868, p. 129. ~ 


Hicks (John Bruxton). 

On Fresh-Water Algz. 
vii. 

On the Diamorphosis of Lyngbya, Schizogonium, and 
Prasiola. Ibid., N.S., vol. i. 

On the Motionless Species (Statospores) of Volvox 
globator. Ibid., N. S., vol. i. 

Remarks on Mr. Archer’s Paper on Alge. 
iv. p. 253. 

On the Ameboid Form of Volvox globator. 
1860, p. 99. 

Observations on the Gonidia and confervoid filaments 
of Mosses, and on the relation of their Gonidia to 


those of Lichens and of certain Fresh-water Algex. 
Trans. Linnean Soc., 1862, p. 567. 


Microscop. Journ., N.§., vol. 


Ibid., vol. 


Ibid., 


BIBLIOGRAPHY. 


Hicks (J. B.).— Continued. 


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Kryptogamischer Ursprung der Miasmen. 
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831 October, 1872. 


Hedwigia, 1852, 


Pringsheim’s 


Botanische 


241 


Itzigsohn (Hermann).— Continued. 
Bemerkung zu Rivularia gigantea, Grent. 
1853. 
Ueber den mannlichen Geschlechts-apparat bei Spiro- 
gyra und einigen andern Conferven. Botanische 
Zeitung, 1853. 


Die Nostoc-Diamorphose. 


Ibid., 


Ibid. 


Die Fortpfianzung der Oscillarien. Thid. 

Ein Wort iiber Hyalotheca und Micrasterias. Ibid., 
1853, p. 485. 

Ueber die Sporenbildung der Cladophora. Ibid., 1852, 
pp. 549, 569, 723, 785. 

Ueber das Studium der Siisswasseralgen. Regensb. 


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Regens- 


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Dissertatio 


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242 


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Paris, 


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Trans- 


BIBLIOGRAPHY. 


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Translated in Bull. Sci. 


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Microscopische Organismen der Alpen und der Itali- 
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Padova, 1793. 


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ANABAENA, 87 
flos-aque, Kiz., 38 
gelatinosa, Wood, 38 
gigantea, Wood, 38 
Androgynia, 198 
echinata, Wood, 198 
Huntii, Wood, 197 
mirabilis, Wood, 196 
multispora, Wood, 196 
Ankistrodesmus falcatus (Corda), 85 
Aphanochate, 211 
repens, Braun, 212 
Aptogonium, 126 
Aptogonium, Baileyi, Ralfs, 127 
Arthrodesmus, 157 
convergens, Lhrb., 159 
incus (Bréb.), 158 
octocornis, Hhrb., 158 
quadridens, Wood, 158 


Bambusina, 125 
Brébissonii, 125 
Batrachospermacee, 217 

Batrachospermum, 219 
moniliforme, Roth, 220 
vagum, Roth, 220 

Bichatia, 12 

Botrydium, 175 
argillaceum, 176 

Bulbocheteaw, 199 

Bulbochete, 201 
Canbyii, Wood, 202 
dumosa, Wood, 202 
ignota, Wood, 201 

Bulbotrichia, 205 
albida, Wood, 205 


“CxiospHzrium, 13 - 
dubium, Grun., 13 
Chetophora, 209 
elegans (Roth), 210 
endiviefolia (Roth), 210 
pisiformis (Roth), 210 
tuberculosa (Roth), 210 
Chetophoracer, 205 
Chantransia, 215 
expansa, Wood, 215 
macrospora, Wood, 216 
viclacea, Kiz., 216 
Chantransiacee, 215 
Chlamydococcus, 99 
nivalis, 99 
Chlorococcum, 87, 88 
Chlorophyllacee, 77 
Chroococcacez, 10 
Chroococcus, 11 
multicoloratus, Woud, 11 
refractus, Wood, 11 
thermophilus, Wood, 12 
Chroolepidex, 2/3 
32 October, 1872 


INDEX. 


Chroolepus, 204 
aureum, Kiz., 204 

Chthonoblastus, 21 
repens, Ktz., 21 

Cladonia, 88 

Cladophora, 187 
brachystelecha, Rabenhorst, 188 
fracta, Dillwyn, 188 
glomerata (Linn.), 187 

Closterium, 109 
acerosum, (Schr.), 111 
areolatum, Wood, 111 
amblyonema, Firb., 116 
angustatum, Atz., 110 
Cucumis, Fhrb., 113 
Diane, Fhrb., 114 
Ehrenbergii, Afengh., 118 
Jenneri, Ralfs, 115 
juncidum, Ralfs, 110 
Leibleinii, Atz., 114 
lineatum, Ehrb , 112 
Lunula (Miller), 111 
maximum (var.),111 
moniliferum (Bory), 113 
parvulum, Negel., 115 
rostratum, Ehrb., 115 
setaceum, Ehrb., 116 
striolatum, Lhrb., 199 
trabecula, Bailey, 120 
Venus, Kiz., 114 

Coccophye?e, 78 

Coleochete, 212 
scutata, Bréb., 213 

Collema bulbosum, 25 

Conferva, 186 
muralis, Dillw., 22 

Confervacee, 186 

Conjugata longata, Vaucher, 166 

Conjugation, 161 

Connecting cells, Thwaites, 23 

Cosmarium, 127 
ameuum, Bréb., 130 
bioculatum, Bréb., 131 
Botrytis, Bory, 128 
Brébissonii, Menegh, 128 
Broomei, Thw., 133 
celatum, Ralfs, 133 
comwmissurale, Bréb., 132 
connatum, Bréb., 134 
crenatum, Ralfs, 131 
Cucumis, Corda, 130 
depressum, Bailey, 130 
margaritiferum (Turp.), 127 
Menegheunii, Bréb., 131 
ornatum, Ralfs, 132 
ovale, Ralfs, 128 
pyramidatum, Bréb., 130 
Quimbyii, Wood, 134 
sublobatum, Bréb., 132 
suborbiculare, Wood, 129 
tetropthalmum, Atz., 129 


Cosmarium. 
Thwatesii, Ralfs, 134 
undulatum, Corda, 132 
verrucosum, Bailey, 121 

Cylindrospermum, 39 
comatum, Wood, 41 
flexuosum, Rabenh., 40 
macrospermuin. Atz., 40 
minutum, Wood, 39 

Cystiphore, 10 

Cystococcus, 88 


Dasyactis, 50 
mollis, Wood, 50 
Desmidium, 126 
aptogonium, Bréd., 126 
eustephanum, Lhrb,, 155 
quadrangulatum, Aiz , 126 
senarium, Jhrb., 155 
Swartzii, Agardh., 126 
Dictyospherium, 84 
pulchellum, Wood, 84 
Didymocladon cerberus, Bailey, 154 
furcigerum, Bréb., 154 
Didymoprium, 125 
Brébissonii, Atz., 126 
Borreri, Ralfs, 125 
Grevillii, Atz., 125 
Docidium clavatum, Atz., 120 
constrictum, Bailey, 121 
Ehrenbergii, Ra//s, 118 
hirsutum, Barley, 121 
minutum, Ralfs, 107 
nodosum, Bailey, 120 
nodulosum, Bréb., 120 
pristilda, Hobson, 122 
undulatum, 120 
verrucosum, Bailey, 121 
verticillatum, Ralfs, 121 
Dolichospermum, 41 
polyspermum, 42 
subrigiduin, Wood, 43 
Draparnaldia, 207 
Billingsii, Wood, 208 
cruciata, Hicks, 209 
glomerata (Vauch.), 207 
maxima, Wood, 207 
opposita, J7arv., 227 
plumosa ( Vauch.), 208 


EntTeRoMoRPHA intestinalis (Linneus), 
183. 
Euastrum, 135 
affine, Ralfs, 138 
ampullaceum, Ralfs, 138 
ansatum, Lhrb., 139 
binale (Turpin), 140 
circulare, Hassal, 139 
crassum (Bréb.), 137 


( 249 ) 


250 


Euastrum. 
didelta (Turpin), 138 
elegans (Bréb.), 140 
gemmatum (Bréb ), 136 
insigne, Ralfs, 138 
Jenneri, Archer, 139 
margaritiferum (ZTurp.), 127 
multilobatum, Wood, 135 
oblongum ( Greville), 136 
ornatum, Wood, 137 
Rulfsii, Rabenh., 139. 
verrucosum, Larb., 136 

Evennia, 88 


GrooRraPHicaL List, 229 
Globulina, Turpin, 12 
Gloeocapsa, 12 
sparsa, Wood, 13 
Gloeoprium mucosum, Hussal, 124 
Gloiotricha, 45 
angulosa (Roth.), 47 
incrustata, Wood, 45 


Heterocysts, 23 
Hyalotheca, 124 

disilliens (Smith), 124 

mucosa (Mert.), 124 
Hydrodictyon, 92 

utriculatum, Roth, 95 
Hy drogastrex, 175 
Hydrogastrum, 175 

granulatum (Linn.), 175 
Hydrurus, 226 

penicillatus, Ag., 227 

occidentalis, Llarv., 227 


Istamra, 123 
Isthmosira, 123 


Lemanga, 223 
catenata, Ktz., 223 
fluviatilis, Ag., 223 
torulosa (Roth), 223 
Lemaneacez, 221 
Lyngbya, 22 
bicolor, Wood, 22 
copulata, Harvey, 22 
muralis, Ag., 22 


Masticonema, 51 
elongatum, Wood, 53 
fertile, Wood, 51 
halos, Wood, 52 
sejunctum, Wood, 53 

Mastigothrix, 55 
fibrosa, Wood, 55 

Merismopediu, 14 
convoluta, Bréb., 15 
glauca, 15 
Mediterranea, Nay., 15 
nova, Wood, 14 

Mesocarpus, 173 
parvulus, Hassal, 174 
scalaris, Hassal, 173 

Mesotenium, 105 

Micrasterias, 141 
Americana (Lhrb.), 143 
arcuata, Bailey, 141 
Baileyi, Ralfs, 143 
denticulata (Bréb.), 145 
disputata, Wood, 142 
expansa, Bailey, 141 
fimbriata, Ralfs, 145 
foliacea, Bailey, 147 
furcata, Agardh, 144 


INDEX. 


Micrasterias. 

granulata, Wood, 146 

incisa, 142 

Jenneri, Ralfs, 146 

oscitans, Ralfs, 142 

papillifera, bréb., 146 ; 

pinnatifida, Atz., 143 

quadrata, Bailey, 142 

radiosa, Agardh, 145 

rotata, Ralfs, 144 

ringens, Bailey, 143 

Torreyi, Bailey, 147 

truncata, Corda, 144 
Microcystis, Menegh., 12 
Monactinus duodenarius, Bailey, 98 

octenarius, Bailey, 98 


NemMAToGENEs, 15 

Nostoc, 27 
arcticum, Berkeley, 225 
Austinii, Wood, 27 
alpinum, Atz., 29 
ceruleum, Lyngb., 31 
calcicola, Ag., 33 
calidarium, Wood, 34 
Cesatii, Bals., 32 
comminutum, Ktz., 36 
commune, Vaucher, 37 
cristatum, Bailey, 29 
depressum, Wood, 30 
flagelliforme, Berk. and Curtis, 

226 

lichenoides, 30 
microscopicum, Curm., 226 
punctatum, Wood, 32 
pruniforme, Agh., 28 
sphericum, Vauch., 30 
Sutherlandii, Dickie, 29 
verrucosum, Vauch., 28 

Nostochacex, 23 

Nostochopsis, 44 
lobatus, Wood, 45 

Nematophycee, 181 


OscrtuaRta, 17 
chlorina, Kitzing, 18 
corium, Agardh,17 
decorticans, Gener., 17 
Frohlichii, Avz., 18 
imperator, Wood, 20 
limosa, Agardh, 19 
muscorum, Agardh, 17 
neglecta, Wood, 20 
nigra, Vauch., 17,19 
tenuis, Ag., 17 
tenuissima, Ag., 17 
princeps, 21 
Oscillariacex, 16 
Odontella, 123 
tridentata, Bailey, 127 
CEdogoniacez, 188 
CGEdogoniex, 190 
Cdogonium, 195 
Huntii, Wood, 197 
inequalis, Wood, 195 
mirabilis, Wood, 196 
multispora, Woud, 196 


PAGEROGALLA, 81 
stellio, Wood, 82 
Palmella, 79 
dura, Wood, 80 
hyalina, Lyngb., 81 
Jesenii, Wood, 79 
Palmellaceex, 78 


Palinogloea, 105 


Palmoglea. 
clepsydra, Wood, 105 
Pediastrum, 95 
Boryanum (Turpin), 97 
constrictum (/Hassal), 97 
duodenarius, 98 
Ehrenbergii (Corda), 98 
pertusum, Kilzing, 97 
selenea, Kiuizing, 97 
Penium, 106 
Brébissonii (Menegh.), 108 
closteroides, Raljs, 109 
digitus (hrb.), 106 
interruptum, Bréb., 108 
Jenneri, Ralfs, 108 
lamellosum, Brébisson, 107 
margaritaceum, Lhrb., 107 
minutum, Cleve, 107 
Petalonema, 66 
alatum, Berkely, 66 
Phychochrom, 16 
Phycochromophyceg, 9 
Phycocyan, 16 
Phykokyan, 16 
Physcia, 88 
Pilinia, 211 
diluta, Wood, 211 
Pleurocarpus, 174 
mirabilis, Braun, 174 
Pleurococcus, 78 
pulvereus, Wood, 79 
seriatus, Wood, 78 
Pleurotenium, 118 
baculum (Bréb.), 119 
breve, Wood, 119 
clavatum (Kiz.), 120 
constrictum (Bailey), 121 
erenulatum, Ehrb., 119 
gracile, Rabenh., 122 
hirsutum (Bailey), 121 
nodosum (Bailey), 120 
trabecula (Ehrb.), 118 
undulatum (Bailey), 120 
verrucosum (Bailey), 121 
verticillatum, Raben., 121 
Polyedrium, 88 
enorme, Ralfs, 89 
Porphyravceer, 214 
Porphrydium, 214 
cruentum (Aq.), 214 
magnificum, Wood, 215 
Pringsheimia,195 
inequalis, Wood, 195 
Protococeacee, 85 
Protococcus, 86 
Protoderma, 182 
viride, Kitzing, 182 


Raapurpium, 85 
falcatum, 85 
polymorphum, Fresen, 85 
Rhynchonema, 163 
elongata, Wood, 164 
pulchella, Wood, 164 
Rhodophycee, 213 
Rivularia, 47 
calearea, Sm., 50 
cartilaginea, Wood, 47 
Rivulariacex, 43 


Satmacis, 163 

Scenedesmus, 89 
acutus, Meyen, 90 
obtusus, Meyen, 90 
polymorphus, Wood, 91 
quadricauda (Turpin), 91 
rotundatus, Wood, 91 


Schizomeris, 184 
Leibleinii, 185 
Scytonema, 57 
Austinii, Wood, 58 
calotrichoides, Aitzing, 61 
cataracta, Wood, 62 
cortex, Wood, 64 
dubium, Wood, 63 
immersum, Wood, 59 
Myochrous, Ag., 61 
Negelii, Ktz., 59 
ocellatuin, Harvey, 63 
Ravenellii, Wood, 64 
simplice, Wood, 57 
thermale, 60 
Scytonemacea, 55 
Siphophycez, 174 
Sirosiphon, 73 
acervatus, Wood, 74 
argillaceus, Wood, 73 
compactus (Ag.), 69 
coralloides, 75 
Crameri, Briigg, 70 
guttula, Wood, 73 
lignicola, Wood, 72 
neglectus, Wood, 71 
pellucidulus, Wood, 69 
pulvinatus, 75 
scytenematoides, Wood, 68 
Sirogonium, 178 
retroversum, Wood, 173 
Sirosiphonacez, 67 
Spermatia, 23 
Spermosiren, 37 
Sphezrozosma, 123 
excavatum, Ralfs, 123 
pulchrum, Bailey, 123 
serratum, Bailey, 124 
Spherozyga, 43 
Carmichelii, Harvey, 43 
polysperma (Kiz.), 43 
Spirogyra, 163 
crassa, Ki/zing, 171 
decimina, Mi ‘ler, 167 
diluta, Wood, 170 
dubia, Kitzing, 167 
elongata (Berk.), 164 
insignis, Hassal, 166 
longata (Vauch.), 166 
majuscula, Kitz.), 169 
nitida (Diller.), 169 
protecta, Wood, 165 
parvispora, Wood, 169 


INDEX. 


Spirogyra. 
pulchella, Wood, 164 
quinina, Ag., 167 
rivularis (fassal), 168 
setiformis (Roth), 170 
Weberi, Kiz., 165 
Spirotenia, 122 
bryophila (Bréb.), 122 
eondensata (Bréb.), 122 
Spondylosium, 123 
Staurastrum, 147 
alternans, Bréb., 150 
arachne, Ral/s, 152 
aristiferum, Ra/fs, 149 
Cerberus, Bailey, 154 
crenatum, Bailey, 151 
cyrtocerum, Bréb., 151 
dejectum, Bréb., 148 
dilatatum, Lhrb., 150 
enorme, Ral/s, 89 
eustephanum, Ralfs, 155 
furcigerum, Bréb., 154 
gracile, Ralfs, 152 
hirsutum, Earb., 158 
Hystrix, Ral/s, 154 
Lewisii, Wood, 149 
longispinum, Archer, 148 
margaritaceum, Hhrb., 150 
munitum, Wood, 154 
muticum, Bréb., 148 
orbiculare, Ehrb., 148 
paradoxum, Meyen, 152 
polymorphum, 151 
polytrichum, Perty, 153 
punctulatum, Bréb., 151 
Ravenellii, Wood, 153 
senarium, Ehrb., 155 
tricorne, Menegh., 150 
Stephanoxanthium eustephanun, 
Kiitzing, 155 
senarium, Kétzing, 155 
Stigonema mammellosuam, 77 
Ravenelii, Berkeley, 76 
Stigeoclonium, 206 


Tetmemorvs, 116 
Brébissonii (Menegh.), 116 
giganteus, Wood, 117 
granulatus (8réb.), 117 
lavis (Kdtz.), 118 
Tetraspora, 82 
bullosa (Roth), 84 


251 


Tetraspora. 
gelatinosa (Roth), 83 
lubrica (Roth), 82 
perforata, Harvey, 82 
Tolypothrix, 65 
distorta (Miller), 65 
Triploceras, 121 
gracile, Bailey, 122 
verticillatum, Bailey, 121 
Tuomeya, 221 
fluviatilis, Harvey, 221 
Tyndaridea cruciata, Hassal, 172 
insignis, Hassal, 171 


Unva, 182 
latissima, Harvey, 183 
merismopedioides, Wood, 182 
orbiculata, Rabenhorst, 183 
Ulvacez, 182 


Vaucueria, 179 
aversa, Hassal, 181 
cespitosa ( Vaucher), 179 
geminata ( Vaucher), 180 
polymorpha, Wood, 180 
sessilis ( Vaucher), 179 
sericea, Lyngbya, 181 
velutina, Agardh, 180 
Vaucheriacee, 176 
Volvocinez, 99 
Volvcx, 100 
globator, 100 


Xanraipium, 156 

aculeatum, Ehrb , 156 
Arctiscon, Ehrb., 156 
armatum (Bréb.), 156 
bisenarium, Ehrb., 156 
Brébissonii, Ralfs, 156 
coronatum, Fhrb., 157 
eristatum, Bréb., 157 
fasciculatum, Lhrb., 157 


Zovnorricata, 48 
minutula, Wood, 50 
mollis, Wood, 48 
parcezonata, Wood, 49 
Zygnema, 171 
insigné (Hassal), 171 
cruciatim, Vauch., 172 
Zygnemacez, 159 
Zygophycez, 100 


CORRECTIONS OF THE PLATES. 


Plate IV., for Zonotricha read Zonotrichia. - 

Plate VIII., for um in the terminations of the specific name of figures 2, 3, 
and 4, read us. 

Plate IX., fig. 3, for argillacea read argillaceus. ss 

Plate X., fig. 4, for Botryococcus pulchellus read Dictyospherium pulchellum. 

Plate XI., fig. 5, 6, and 7, for Cosmarium read Closterium. 

Plate XII., fig. 1 and 20, for Cosmarium read Closterium. 

Plate XV., fig. 8, for insignis read insigne. 

Plate XVI, fig. 4, for Bulbotricha read Bulbotrichia. 

Plate XVIIL., fig. 1, for Pringsheimii read Pringsheimia. 

Plate XXI., fig. 7, for tetraopthalmum read tetropthalmum. 


EXPLANATION OF PLATES, 


PLATE I. 


Fig. 1. A single filament of Oscillatoria chlorina, Kiitzing, magnified 750 diameters. 


Fig. 2. The end of a filament of an Oscillatoria supposed to be identical with O. Fréhlichii 
Kiitzing. 

Fig. 8. O. nigra, Vaucher. 

Fig. 3 a. Represents a portion of a mat or mass of Oscillatoria nigra, Vaucher; there is too 
much green in the color. 

Fig. 3 6. Represents several filaments separated from the edge of* the mass and slightly magni- 
fied. 

Fig. 3c. A portion of a filament. 

Fig. 3 d. A portion of another filament still more highly magnified. The color in 3 ¢ is more 
natural than that of 3 d. 

Fig. 4. A portion of a filament of O. limosa, Agardh, magnified 1250 diameters. The articles in 
this filament are more distinctly separated than natural. 

Fig. 5. O. neglecta, Wood. 

Fig. 5a. An outline view of a filament, magnified 450 diameters. 

Fig. 5 6. A full figure of the same, magnified 500 diameters. 

Fig. 6 0. imperator, Wood. 

Fig. 6 a. Represents the end of a filament, magnified 250 diameters. In the centre of the plate 
is a fragment (marked simply fig. b.), out of which the endochrome has been partially squeezed to 
show the markings of the sheath at the joints. 

Fig. 7. Lyngbya bicolor, Wood. Fig. 7 represents a moderately magnified portion of a filament. 

Fig. a (near to fig. 8) represents a portion of an ordinary filament very slightly magnified. 

Fig. T¢. A portion of a filament containing a heterocyst, magnified 800 diameters. 

Fig. 7d. A broken end of a filament showing the sheath extending beyond the endochrome, 
magnified 800 diameters. 

Fig. 8. A variety(?) of Lyngbya bicolor, Wood, from the Schuylkill River, magnified 200 dia- 
meters. 

Fig. 9. Cosmarium Quimbyii, Wood. The bands between the cells are too heavy and prominent. 


PLATE II. 


Figs. lbandle. Different stages of germination of the spore of a Cylindrospermum of unknown 
species, magnified respectively 800 and 1200 diameters. 

Fig. 1 a. A chain of spores, believed to belong to the same species; one of these Spores has 
commenced to germinate. 

Fig. 2. A portion of the upper surface of a frond of Nostoc calidarium, Wood. 


(253) 


204 EXPLANATION OF THE PLATES. 


Fig. 26. A ‘first form” filament of the same species. 

Fig. 2a. A filament from an old frond of the same plant. 

Fig. 2c. Fragments of tissue from the upper surface of a mature, actively growing plant of the 
same species. 

Fig. 3. A filament of Nostoc comminutum, Ktz , magnified 800 diameters. 


Fig. 4. A filament of Anabzna gelatinosa, Wood, magnified 750 diameters, showing the large 
globular body at the end, supposed to be a spore. 


Fig. 5. A filament of Anabena gigantea, Wood, magnified 750 diameters. 


Fig. 6. <A portion of a filament of Cylindrospermum minutum, Wood, magnified 800 diameters. 
The number has been omitted from this figure on the plate; the figure is immediately under A. 
gigantea, Wood; the hairs on the heterocyst are too coarse and rigid. 


Fig. 7. A spore and outline of heterocyst of Cylindrospermum macrospermum, Ktz., magnified 
750 diameters. 


Fig. 8. The end of a filament of Cylindrospermum comatum, Wood, magnified 1375 diameters. 
The appendages to the heterocyst are coarser than natural. 


Fig. 9a. A section of an immature frond of Rivularia cartilaginea, Wood. 
Fig. 95. The base of a fertile filament, showing the spore and basal cells, magnificd 800 dia- 
meters. 


Fig. 10. An ordinary filament of Nostoc sphericum, Poiret. 
Figs. 10aand10c. Filaments enlarging preparatory to longitudinal division. 
Fig. 106. A filament already partially divided into two. 


PLATE IIT. 


Fig. 1a. Cylindrospermum flexuosum (Ag.), a fertile filament, magnified 450 diameters. 
Fig. 16. The end of a fertile filament, magnified 750 diameters. 


Fig. 2. Dolichospermum (Spherozyga) subrigidum, Wood, magnified 975 diameters. 


Fig. 3. Portion of a fertile filament of Dolichospermum (Spherozyga) polysperma, Ktz., magnified 
750 diameters. 


Fig. 4a. A section of a frond of Gloiotrichia incrustata, Wood, showing youngish filaments, 
masses of lime, and an organic body of unknown nature, all inclosed in a transparent jelly. 

Fig. 4c. Single filaments with immature spores, magnified 260 diameters. 

Fig. 46. The base of a filament, showing the nearly matured spore, and empty cells situated 
beyond it. 


Fig. 5. Chlorococcus of undetermined species. 

Fig. 5a. The motile state. 

Fig. 5 5. The condition of the plant after having lost its cilia and commenced its quiescent 
life. 

Figs. 5 and 5c. Different stages in this life after division. 

Fig. 5 d. The Hematococcus or resting condition, the form assumed by the plant during slow 
desiccation. 


Fig. 6. Nostochopsis lobatus, Wood. 

Fig. 6 a. Part of a section, from within outwards, of the frond, showing the tortuous branched 
filaments, without sheaths in the gelatinous matrix. 

Fig. 6 6. A portion of a fertile filament with the lateral spores. 

Fig. 6c. A sterile filament. 


Fig. 7. Protococcus of undetermined species. 
Fig. 7a. A cell supposed to belong to the resting or winter condition of the plant. 


EXPLANATION OF THE PLATES. 255 


Fig. 7b. The first breaking-up of the contents of the large cell into a brood of cells. 
Figs. 7d and 7c. Different stages in the life of the latter brood-cells and their progeny. 


PLATELV. 


Fig. 1. Mastigonema fertile, Wood, a single plant (noé magnified 750 diameters, as marked on 
the plate). 


Fig. 1b. A heterocyst magnified 750 diameters, also a spore cell and spore similarly amplified. 


Fig. 2a. <A portion of the frond of Mastigonema sejunctum, Wood, amplified 250 diameters. 
Fig. 2b. A single filament magnified 800 diameters. 


Fig. 3. A single filament of Zonotrichia mollis, Wood, enlarged 260 diameters. 
Fig. 4. A section of the frond of Zonotrichia parcezonata, Wood, magnified a few diameters. 


Fig. 5. The base of a filament of Dasyactis mollis, Wood. 
Fig.5 a. Section of the frond, magnified 450 diameters. 
Figs. 56 and 5c. Young filaments; each magnified 450 diameters. 


Fig. 6. Fronds of Calospherium dubium, Wood. 


PLATE V. 


Fig. 1a. A portion of the frond of Mastigonema elongotum, Wood, slightly magnified to show 
the filaments radiating from the fragment of matter to which they are attached. 
Fig. 1b. A single filament magnified 460 diameters. 


Fig. 2c. A cluster of youngish filaments of Mastigonema halos, Wood. 

Fig. 26. A portion of an older filament to show the spore-like divisions of the endochrome, mag- 
nified 460 diameters. 

Fig. 3. A pair of young connate filaments of Mastigothriz jibrosa, Wood, magnified 450 
diameters. 

Fig. 3a. An old filament magnified 800 diameters. 

Fig. 36. <A young filament with heterocyst, enlarged 450 diameters. 

Fig. 3d. A filament with two basal cells magnified 450 diameters. 

Fig. 4a. <A portion of filament of Scytonema Ravenelliz, Wood, magnified 160 diameters. 

Fig. 4b. The end of a branch magnified 450 diameters. 

Figs. 5 a,b, c, &e. Different forms of Chroococcus refractus, Wood. Fig. 5 h is not a good 
one. I was not able to express well the peculiar translucent shining tint, and the artist who copied 
my drawing failed even more decidedly in simulating it; the pink shade is altogether wrong, I 
never saw any such color in the plant. 


Fig. 6. Different forms of Chroococcus multicoloratus, Wood. 
Fig. 6c. Represents what was thought to be possibly a hybernating form of the species. 


PLATE VI. 


Fig. 1a. A portion of a frond of Scytonema thermale, Ktz., magnified 260 diameters. 
Fig. 1b. Outline sketch, showing the form of the heterocyst, magnified 750 diameters. 


Fig. 2. Trichoma or frond of Scytonema callitrichoides, Ktz., amplified 250 diameters. 
Fig. 3a. Outline sketch showing the cells or chambers of Scyfonema dubiwm, Wood, magnified 


750 diameters. 
Figs. 3b and 3c. Portions of the filaments or trichoma, maguified 460 diameters. 


256 EXPLANATION OF THE PLATES. 


Figs. 4 and 4b. Scytonema cortex, Wood. Portions of filaments, magnified 750 diameters, 


Fig. 5. Piece of a small twig with a well-formed and also a very young frond of Chetophora 
elegans, Ag., growing upon it, magnified a few diameters. 


: PLATE VII 


Fig. 1. A perfect trichoma of Scyfonema cataractum, Wood. 
Fig. 16. A terminal part of a filament, magnified 250 diameters. 


Fig. 2a. A portion of a filament of Scytonema immersum, Wood, magnified 750 diameters. 
Fig. 26. Nearly a whole filament or trichoma, amplified 260 diameters. 


Fig. 3. Rhaphidium polymorphum, Wood, different forms, magnified 750 diameters. 


Fig. 4. Protococcus of undetermined species. 

Fig’ 4a. The largest and most mature form, probably the hibernating or winter cell. 

Fig. 4b. The same, commencing its active life. 

Fig. 4d. Colony cells believed to have been developed out of the cell represented by fig. 4 8, 
magnified 750 diameters. 

Figs. 4and 4c. The motile state of the species. 


PLATE VIII. 


Fig. 16. Portion of the frond of Tolypothrix distorta (Miller), magnified 500 diameters. 
Fig. 1a. Heterocysts magnified 800 diameters. 


Fig. 2. Portion of a frond of Strosiphon pelluctdulus, Wood, magnified 260 diameters. - 
Fig. 2. End of the branch. 


Fig. 3. Portion of a frond of Sirosiphon compactus (Ag.), magnified 260 diameters. 
Fig. 3a. End of a filament, magnified 160 diameters. 
Fig. 3¢. Portion of a filament showing the heterocyst magnified 460 diameters. 


Fig. 4. Portion of a frond of Sirosiphon neglectus, Wood. 


Fig. 5. Frond of Strostphon guttula, Wood. 
Fig. 5 6. End of a branch, magnified 460 diameters. 


Fig. 6. Portion of a frond of Scytonema Negelii, Ktz. 
Fig. 7. Different forms of Gleocapsa sparsa, Wood, magnified 700 diameters. 
Fig. 8. Merismopedia nova, Wood, magnified 400 diameters. 


PLATE IX. 


Fig. 1. Fragment of a frond of Sirosiphon scytenematoides, Wood. 


Figs. 2and 2c. Portions of fronds of Strosiphon lignicola, Wood, magnified 260 diameters. 
Fig. 2. The end of a branch of the same, magnified 460 diameters. 


Fig. 3a Portion of a very old frond of Sirosiphon argillaceus, Wood, magnified 460: diameters. 
Fig 36. <A terminal branch of a growing frond of the same. 


Fig. 4a. A frond of Stigonema Ravenelii, Berkeley, magnified 125 diameters; also a fragment 
of the same plant, magnified 450 diameters. 


EXPLANATION OF THE PLATES. 257 


PLATE X. 


Fig. 1a. <A frond of Sirosiphon pulvinatus, Bréb., var. parvus, from a specimen collected by 
Dr. J. G. Hunt, near Philadelphia. The ground color of this figure is too yellow. 
Fig. 1b. A fragment of the same, magnified 460 diameters. 


Fig. 2. <A row of cells of Plewrococcus seriatus, Wood, magnified 460 diameters. 
Fig. 8a. A portion of the old external part of a mass of Palmella Jessenii, Wood, magnified 750 
diameters. 


Fig. 3b. A fragment from the interior of such a mass of the same Amplification. 
Fig. 8. A portion of the soft jelly of a young actively growing mass, magnified 750 diameters. 


Fig. 4. A frond of Dictyospherium pulchellum, Wood, magnified 460 diameters. I at first 


referred this plant to the genus Borryococcus, and distributed some specimens under that generic title, 
and so marked my original drawing. 


Fig. 5. A slice of a youngish frond of Palmella dura, Wood, magnified 460 diameters. 
Fig. 5 b. A fragment from an old frond, showing the spores in various stages of growth. The 
color of the large spores is not nearly dark enough, it should be much more brownish. 


PLATE XI. 


Fig. 1. Different forms of Scenesdesmus polymorphus, Wood, magnified 450 diameters. 

Fig. 2. Scenedesmus quadricauda, Bréb., magnified 750 diameters. 

Fig. 3. Scenedesmus rotundatus, Wood, magnified 750 diameters. 

Fig. 4. Ordinary vegetative cells of Palmoglea clepsydra, Wood, in different stages or con- 
ditions of life-history, magnified 750 diameters. Those cells which have the endochrome much 
broken up are believed to be preparing for conjugation. 

Fig. 4a. <A pair of cells uniting in conjugation. 

Fig. 4 6. Cells which have united so that the young spore is very apparent with the empty semi- 
cells of the parents attached to it. 

Fig. 4c. A more advanced spore and empty semi-cells. 

Figs. 4d and 4e. Matured or nearly matured spores, as seen with different focussing; in the 
first the upper surface of the spore is especially brought out. All these figures, except 4 0, are 
magnified 750 diameters. 

Figs. 5 and 5a. Different forms of Closterium acerosum (Schr.), magnified 250 diameters. 

Fig. 56, Empty conjugating cells with nearly matured spore. 

Fig. 6. Outline of Closterium areolatum, Wood, magnified 160 diameters. 

Fig. 6 a. End of a dead, empty frond, enlarged 1375 diameters. 

Fig. 7. Outline of Closterium Venus, Ktz., magnified 450 diameters. 

(These last three species are incorrectly labelled on the plate, Cosmarium.) 


PLATE XII. 


Fig. 1. Closterium lineatum, Ebrb. (Incorrectly labelled on the plate Cosmarium.) Magni- 
fied 160 diameters. 

Fig. 2. Closterium Ehrenbergit, Menegh., magnified 160 diameters. 

Fig. 38. Closterium rostratum, Ehrb., magnified 260 diameters. 

Fig. 4.  Closterium Diane, Ehrb., magnified 260 diameters. 


Fig. 5. Closterium parvulum, Neg., magnified 450 diameters. 
33 October, 1872. 


258 EXPLANATION OF THE PLATES. 


6. Closterium Leibleinit, Ktz., magnified 260 diameters. 
q. Tetmemorus giganteus, Wood., magnified 260 diameters. 
Fig. 8. Tetmemorus granulatus (Bréb.), magnified 450 diameters. 
9. Pleurotenium Trabecula (Ebrb.), magnified 160 diameters. 
Fig. 10. Sptrotenia bryophila (Bréb.). 
Fig. 11. Spirotxnia condensata, Bréb. 
Fig. 12. Hyalotheca dissiliens, Bréb. 


Fig. 18. Didymoprium Grevillii, Ktz. 
Fig. 13 a. End view. 


Fig. 14. Cosmarium Botrytis (Bory.), magnified 460 diameters. 


Fig. 15. Cosmarium Cucumis, Corda. 

Fig. 15 d. A frond in which the neck or isthmus has begun to elongate previous to division. 

Fig. 15 6. An abnormal frond which has attempted division, but in which the inner.semicells of 
the new frond have failed to form perfectly and to separate. 


Fig. 16. Huastrum multilobatum, Wood ; front view. 
Fig. 17. Micrasterias Americana (Ehbrb.). 


Fig. 18. Cosmarium Menegheniti, Bréb., magnified 750 diameters. The sinus should be very” 
narrow but distinct, instead of being absent as in the figure. 


Fig. 19. Spirogyra Weberi, Ktz., portions of conjugating filaments, magnified 260 diameters. 
Fig. 19a. <A portion of a sterile filament, magnified 160 diameters. , 
Fig. 19 6, Conjugating cells with nearly mature spores, magnified 260 diameters. 


Fig. 20. Clostertum juncidum, Ralfs., magnificd 260 diameters, 


Fig. 21. Cosmarium margaritiferum (Turp.), magnified 460 diameters. 


PLATE. X ELL, 


Front view of Zuastrum Ralfsii, Rabenh., magnified 450 diameters. 
Front of Huastrum elegans, Bréb., enlarged 750 diameters. 


Front view of Huastrum binale (Turp.), magnified 750 diameters. 
Front view of Micrasteria disputata, Wood, drawn from a Philadelphia specimen. 


lL: 
2. 
3. 
4. 
Fig. 4a. The same after a figure drawn by Dr. Jos. Leidy, from a Newport specimen. 
5. Micrasterias furcata, Agardh., front view, magnified 260 diameters. 

6. Front view of Micrasterias denticulata, Bréb., magnified 260 diameters. 

4. Micrasteria Jenneri, Ralfs. Front view. 

8. Staurasirum orbiculare (Ehrb.). Front view. 

Fig. 9. Staurastrum dejectum, Bréb. Front view, magnified 750 diameters. 


Fig. 10. Staurastrum punctulatum, Bréb. Front view. 
Fig. 10 a. View from the apex. 


Fig. 11. Front view of Staurastrum Lewisii, Wood, magnified 750 diameters. 
Fig. 12. Front view of Staurastrum polytrichum, Perty. 


Fig. 13 a. Front view of Staurastrum munitum, Wood. 
Fig. 13 6. End view of the same. 


Fig. 14. Cosmarium pyramidatum, Brébisson. Front view. 


EXPLANATION OF THE PLATES. 259 


Fig. 15. Cosmarium Broomei, Thw. Front view, magnified 460 diameters. 
Fig. 16. Cosmarium comnvissurale, Bréb. Front view, magnified 750 diameters. 


» Fig. 17. Xanthidium armatum, Bréb. Front view, magnified 260 diameters. 


PLATE XIV. 


Fig. 1. A sterile cell of Rhynchonema elongatum, Wood, magnified 450 diameters. 


Fig. 1 a, Portion of a filament containing a fertile cell, with the spore nearly matured, amplified 
450 diameters. 


Fig. 2. A filament of Rhynchonema pulchellum, Wood, containing both fertile and sterile cells, 
magnified 260 diameters. 


Fig. 3. The ripened spore of Spirogyra protecta, Wood, magnified 450 diameters. 
Fig. 3a, Outline of conjugating filaments, and figure of a sterile filament, enlarged 240 diameters. 


Fig. 4. Sterile cells of Spirogyra longata (Vauch.), magnified 250 diameters. 
Fig. 4a. Fertile filaments, magnified 260 diameters. 


Fig. 5.. A filament of Aphanochete repens, Wood, which has lost its cilia, magnified 460 diameters. 


Fig. 6. A fertile branch of Draparnaldia Billingsti, Wood, showing the chains of spores, mag- 
nified 460 diameters. 


PLATE XV. 


Fig. 1. Portion of a filament of Spirogyra majuscula, Ktz., containing cells with mature spores 
and others just commencing the process of conjugation. 


Fig. 2. A portion of a sterile filament of Spirogyra diluta, Wood, magnified 125 diameters, also 
the outline of a'pair of conjugating filaments of the same amplification. 
Fig. 26. Conjugating filaments of Spirogyra diluta, Wood, magnified 125 diameters. 


Fig. 3a. Portion of a sterile filament of Spirogyra seliformis (Roth) Ktz., magnified 125 
diameters, 
Fig. 3b. Conjugating filaments of the same species, similarly amplified. 


Fig. 4a. Cells of Spirogyra crassa, Ktz., preparing for conjugation. 

Fig. 4c. Conjugating cells of the same plant in the first stage of union. 

Fig. 4b. Conjugating cells containing nearly matured zygospores, enlarged 125 diameters. 

Fig. 5. Filaments of Mesocarpus scalaris, Hassall, commencing the process of conjugation, mag- 
nified 125 diameters. 

Fig. 6. Sterile cells of Spirogyra insignis (Hassall) Ktz. 

Fig. 6 6. Conjugating filaments of the same species. 

Fig. 7. Conjugating filaments of Spirogyra parvispora, Wood, containing nearly matured 
spores, magnified 125 diameters. 

Fig. 8. Portion of an ordinary sterile filament of Zygnema insigne (Hassall) Ktz. 

Fig. 8a. Fertile filaments of the same, magnified 250 diameters. 

Fig. 8b. Sterile filament in which multiplication of the species is taking place by the separation 
of the cells, magnified 260 diameters. 


PLATE XVI. 


Fig. 1a. Cells of Sirogonium retroversum, Wood, just commencing the process of conjugation, 


Fig. 1b. Sterile cells. ; 
Figs. 1 dand1e. Outlines of fertile cells; all of these figures are magnified 260 diameters. 


260 EXPLANATION OF THE PLATES. 


Fig. 2. A matured frond of Hydrogastrum granulatum (Linn.), enlarged 90 diameters. 
Fig. 2a. A-resting spore of the same, enlarged 160 diameters ; alsoa minute, very young frond, 


magnified 90 diameters. 
Fig. 4. A branch of a Stigeoclonium, emitting zoospores, enlarged 460 diameters. i 


Fig. 5. Bulbotrichia albida, Wood, magnified 460 diameters. 


Fig. 6a. A fertile branch of Bulbochete Canbyti, Wood, showing the matured spore, magnified 
260 diameters. 

Fig. 6b. A young plant. 

Fig. 6c. A branch with young male plants, and a forming zoosporangium, magnified 260 
diameters. 

Fig. 6d. The empty cup left after the discharge of the oospore. 

Fig. 6¢e. Outline of sporangium. 


Fig. 9. A young plant of Stigeoclonium. 


The globular figures in the lower part of the plate are separate cells of Porphrydium magnificum, 
Wood, magnified 760 diameters. The numbering of the figures at the bottom of the plate are 
wrong, fig. 3 should read fig. 4, 4, 5, &. 


PLATE XVII. 


Fig. 1 a. The basal portion of an old frond of Schizomeris Leibleinii, Ktz., ? magnified 120 
diameters. 

Fig. 1b. A filament emitting zoospores, magnified 250 diameters. 

Fig. 1c. <A perfected zoospore. ; 

Figs. 1d, le, le. Young plants formed by the germination of the zoospore, magnified 450 
diameters. 


Fig. 2a. The distal end of a filament of Gdogonium Huntti, Wood. 

Fig. 26. Cells showing the formation and growth of a new cell. 

Fig. 2¢. <A portion of filament containing spores in different conditions of maturity. 

Fig. 2d. A young female plant with attached dwarf plant. 

Fig. 2. Cells emitting a zoospore, magnified 250 diameters. 

Fig. 2g. The perfected zoospore. 

Fig. 2h. Outline sketch of a young male plant, magnified about 1200 diameters. The arrows 
are meant to represent cyclotic currents. 


Fig. 3. A fertile filament of @dogonium multispora, Wood, showing spores in different states of 
maturity, and dwarf male plants. 


Fig. 4.¢. Sterile cells of Spirogyra dubia, Ktz., enlarged 260 diameters. 
Figs. 4 and 4d. Outline sketches of cells containing spores, magnified 260 and 160 respectively. 


Figs. 5aand 5b. Sterile cells of Spirogyra rivularis (Hassall), magnified 260 diameters. 
Fig. 5c. Outline sketch of conjugating cells with spore similarly amplified 


PLATE XVIII. 


Fig. la A young female plant of Pringsheimia inzequale, Wood, magnified 250 diameters. 

Fig. 1 3. A portion of an adult female plant, containing immature spores, and showing in out- 
line in the upper sporangium the orifice through which the spermatozoa enter magnified 250 dia- 
meters. ’ 

Fig. 1c. The supposed young male plant, magnified 450 diameters. 


Fig. 2. Cidogonium mirabile, Wood. A portion of a filament with a partially matured spore. 


EXPLANATION OF THE PLATES. 261 


Fig. 2a. A portion of a female plant, showing the beginning of the development of the female 
germ, 7. e. the formation of a very large cell. 


Fig. 26. A further stage of the process, showing the cell divided into an upper and lower por- 
tion, with the outline of the attached male plant. 

Fig. 2c. <A fertile filament containing a matured spore. All of these figures are magnified 160 
diameters. 


Fig. 2d. A couple of cells, one of which has divided into four daughter-cells, each of which 
contains a nearly perfected androspore, magnified 460 diameters. 

Figs. 2b and 2g. Different views of dwarf male plants discharging spermatozoids, the first figure 
offering a profile view of the cap, the second a view from behind, magnified 400 diameters. 


Fig. 2e. A three-celled dwarf male plant, magnified 460 diameters. 
Fig. 3. Matured spore of Gdogonium echinatum, Wood, uncolored and magnified 750 diameters. 
Fig. 4. Spores in sporangia of a Florida Gidogonium of undetermined species. 


Fig. 5. Bulbochete ignota, Wood. 


Fig. 5 a. Branches of a frond, showing different stages in the early development of the female 
germs. 


Fig. 5b. Sporangium containing a nearly matured spore. All magnified 460 diameters. 


Fig. 6a. Part of a frond of Bulbochate dumosa, Wood, with female germs and dwarf male plants 
in different stages of development, magnified 260 diameters. The fine markings on the spores have 
not been reproduced in the chromo-lithograph from my drawing. 

Fig. 6b. Male plant discharging spermatozoid, magnified 750 diameters. 


Fig. 7a. Part of a sterile filament of a Conferva of unknown species, 
Fig. 7b. The same discharging zoospores. 

Fig. 7c. <A cluster of germinating zoospores. 

Fig. 7. A young plant. All these figures are magnified 500 diameters. 


PLATE XIX. 


Fig. 1. Stigeoclonium, showing chetophoroidal stage. 


Fig. 2. Portion of a fertile filament of Chantransia expansa, Wood, magnified 125 diameters. 
Fig. 2b. A fragment of a fertile branch, magnified 260 diameters. 


Fig. 3. A portion of a fertile filament of Chantransia macrospora, Wood, magnified 460 
diameters. 


Fig. 4a. Outline of some fertile cells of Spirogyra quinina, Ag. 
Fig. 4b. Filaments in an advanced stage of conjugation. 
Figs. 4¢ and 4e. Fragments of sterile filaments. 


PLATE XX. 


Fig. 1. Stigeoclonium, found near Philadelphia. 


Fig. 2. Arthrodesmus quadridens, Wood, as viewed from the end, and magnified 259 diameters, 
also a front view of similar amplification. 


Figs. 3and 3a. Different forms of fructification of Vaucheria polymorpha, Wood, showing the 
emptied antheridia and fertile sporangium. 

Fig. 36. An immature antheridium. 

Fig. 3c. Spore of same species. 


Fig. 4. Section through fertile node of Lemanea torulosa (Roth). 


262 EXPLANATION OF THE PLATES. 


Fig. 5. Outlines of Huastrum multilobatum, Wood. The lower figure represents a lateral view ; 
the upper a two-thirds view. 


Fig. 6. Outline of Pentium digitus, Bréb. 


PLATE XXII. 


Fig. 1. Pleurotenium crenulatum (Ehrb.), an outline view, magnified 160 diameters. 
Fig. 2. Pleurotenitum breve, Wood, the empty dead frond, magnified 750 diameters. 


Fig. 3. Tetmemorus Brébissonti (Mengh.), an empty semicell. 
Fig. 3a. Outline of a whole frond. 


Fig. 4.6. Closterium lineatum (Ehrb.), an empty semicell, magnified 260 diameters. 


Fig. 5. Cosmarium Botrytis (Bory), an empty frond, magnified 750 diameters. 
Figs. 5 @and 5 6. Outlines of semicells to show the variety of form. 


Fig. 6. Cosmarium Brébissonii, Menegh., an empty frond, magnified 750 diameters and outline 
of apex view. 


Fig. 7a. Cosmarium tetropthalmum (Ktz.), outline of the empty frond, magnified 460 diame- 
ters. 


Fig. 8. Cosmarium margaritiferum (Turp.), view of an empty semicell, magnified 750 diame- 
ters; the outline of this should be more regular. 


Fig. 9. Cosmarium suborbiculare, Wood, an empty frond, magnified 750 diameters. 
Fig. 9a. An outline of end view of similar amplitication. ° 


Fig. 10. Cosmarium Broomei, Thw., lateral outline of the frond. 
Fig. 11. Micrasterias Jennerii, Ralfs, an empty semicell. 


Fig. 12. Huastrum ornatum, Wood, front view, magnified 450 diameters. 
Fig. 12a. Lateral view. 


Fig. 13. Huastrum Didelta, Turpin, outline of the front view. 

Fig. 14. Huastrum elegans, Bréb., outline of the lateral view, 

Fig. 15.  Micrasterias truncata, Corda, outline of front view, magnified 260 diameters. 

Fig. 16. Micrasterias granulata, Wood, front view of an empty frond, magnified 460 diameters. 
Fig. 17. Staurastrum orbiculare, Ehrb., outline of the end view. 

Fig. 18. Staurastrum dejectum, Bréb., outline of the end view, magnified 750 diameters. 

Fig? 19. Staurastrum Lewisii, Wood, outline of the end view, magnified 750 diameters. 

Fig. 20. Staurastrum paradoxicum, Mey., outline of end view. 


Fig. 21. The five radiate figure is an end view of Staurastrum Arachne, Ralfs, the triradiate of 
Staurastrum paradozum, Meyen, magnified 750 diameters. 


Fig. 22. Staurastrum Ravenellii, Wood, Front view of the empty frond, magnified 460 diameters 
Fig. 22a. The side view of an empty semicell, magnified 750 diameters. 
Fig. 226. The end view with the same amplification. 


Fig. 23. Staurastrum Polytrichum, Perty, outline of the frond as seen from the end. 


FRESH WATER ALGA. PLATE 1, 


i. ; 


a 


= 


HE RATINGS WPTIsAy BHA GPPIANACS ees AONE) 


750 


te 


<> 


Y. SINCLAIR & SON, PHILADELPHIA 
AFTER NATURE BY DR.H.C.WOOD. . 


i Fig.7. LYNGBYA BICOLOR. 
Fig. 1. O, CHLORINA. Fig. 4. 0. LIMOSA. z 
0 “8. LYNGBYA VARIETY. 
“9, O, FROHLICHH. « 5. QO, NEGLECTA. 


‘ : “9. C. QUIMBYII. 
«“ 3. 0. NIGRA. « 6, ©. IMPERATOR Q 


FRESH WATER ALGA. 


PLATE II 


AFTER NATURE BY DA, H. 0. WOOD 


Fig. | CYLINDROSPERMUM 
* 2 NORLOC CALIDARIUM 
* % NOSTOC COMMINUTUM 


Fig 
M6 


Lin Laon 2 —_—_, 


| 


T. SINCLAIR & SON, PHILADELPHIA 


ANABANA GELATINOSA Fie § © COMATUM 


ANAB/ENA GIGANTEA “9 RIVULARIA CARTILAGINEA 


“ 6 CYLINDROSPERMUM MINUTUM | “ WW NOSTOC SPHARICUM. 


ey Wi 


C MACROSPERMUM 


PLATE Ill, 


FRESH WATER ALGA 


FRESH WATER ALG4& 
a : . 


AFTER MATURE GY OR I woo 


Fig. 1. MASTIGONEMA FERTILE. 
* 2. MASTIGONEMA SEJUNCTUM. 


Fig 3. ZONOTRICHA MOLLIS 


4. ZONOTRICHA PARCEZONATA 


1. SINCLAIR & SON, PHILAD 


DASYACTIS MOLLIS. 


. CELOSPHARIUM DuBiUM, 


PLATE IV. 


Peel ese 


*. 
*s e 
Steg awwe * 


e ° Ls 
© “Sesceetee ® 


e eo” 


—— | 


ELPHIA 


FRESH WATER ALGA. 


. 


PLATE Y. 


“NS 


AFTER NATURE SY DR. H. C, wooo 7, SINOLAIR & SON, PHILADELPHIA 
Fig. 1. MASTIGONEMA ELONGATUM | Fig. 3. MASTIGOTHRIX FIBROSA. | Fig. 6 CHROOCOCCUS MULTICOLOR- 
| 
“« 2. MASTIGONEMA HALOS. | “ 4. SCYTONEMA RAVENELI, ATUS., 
| 


“ 5, CHROOCOCCUS REFRACTUS, 


F 
RESH WATER ALGA. PLATE VI. 


i = 


= , as 
AFTER NATURE BY DR.H.C.WOOD. T. SINCLAIR & SON, PHILADELPHIA. 


Fig. 4 S. CORTEX, 


Fig.1. SCYTONEMA THERMALE. 
“6, CHAETOPHORA ELEGANS, 


“2. S, CALLITRICHOIDES, 


“ 3, S. DUBIUM. 


PLATE VII 


. 
‘ 


4 


T. SINGLAIR & SON, PHILADELPHIA. 


AFTER NATURE BY OR, H. 0, WOOD: 


Fig. 3. RHAPHIDIUM POLYMORPHUM., 


Fig. 1. SCYTONEMA CATARACTUM. 
“4, PROTOCOCCUS. 


“ 9 SCYTONEMA IMMERSUM. \ 


FRESH WATER ALGA. 


U 


poguop9nnned? 00 


TT) 


\ 


PLATE VIII. 


0200 00680909 
0928 2006 9900 
2608 0600 2089 
CO ae 


0000 0800 0066 
GOG9 FOC F990 
2900 6060 9008 
6000 6060 0088 


AFTER NATURE BY DR.H.C. WOOD, 


Fig. 1. TOLYPOTHRIX DISTORTA. 
*“ 9, SIROSIPHON PELLUCIDULUM. 


“ 3, SIROSIPHON COMPACTUM. 


Fig. 4. SIROSIPHON NEGLECTUM. 
# §& SIROSIPHON GUTTULA. 


«“ 6, SCYTONEMA NAGELLII. 


SINCLAIR & SON, PHILADELPHIA. 


Fig. 7. GLOEOCAPSA SPARSA, 


“8. MERISMOPEDIA NOVA, 


‘FRESH WATER ALGA. 


AFTER NATURE BY DA H.C. wood. 


PLATE 


X. 


“Fig. 1, SIROSIPHON SCYTENEMATOIDES. 


Fig. 2, SIROSIPHON LIGNICOLA, 


Fig 4. STIGONEMA RAVENELLII. 


T.SINCLAIR &SON PHILADELPHIA. 


Fig. 3. S. ARGILLACEA, 


FRESH WATER ALGA. 
2 PLATE X. 


AFTER NATURE BY DR. H. C, WOOD. T. SINCLAIR & SON, PHILADELPHIA 
Fig.°3. PALMELLA JESSENN. Fig. 4. BOTRYOCOCCUS PULCHELLUS, 


Fig. 1. SIROSIPHON PULVINATUS. 
ee ET sh PALMELLA DURA, 


“ 2, PLEUROCOCCUS SERIATUS 


FRESH WATER ALGA PLATE II 


aa | 


AFTER NATURE BY DA.H C. WOOD, SAE NGURIRTRROA HAIR DELETE 
Fig. 1. SCENEDESMUS POLYMORPHUS, Fig. 3. SCENEDESMUS ROTUNDATUS. Fig. 6. COSMARIUM AREOLATUM. 
“9. SCENEDESMUS QUADRICAUDA, ‘4. PALMOGLOEA CLEPSYDRA. "7, COSMARIUM YENUS. 


ne “5, COSMARIUM ACEROSUM. 


FRESH WATER ALGAE PLATE XI. 


+3 


aod 


Ma = 2 = 


st 


**= 
= Pn 


i 
i 


© 6 


AFTER NATURE BY OR.H.C.WwOOD 


1. SINGLAIR & SON, PHILADELPHIA 


Fig. 1. COSMARIUM LINEATUM) Fig.6. C, LEIBLEINI), Fig. 11. SPIROTAENIA CONDENSATA Fig. 16, EUASTRUM MULTILOBATUM 
« 2. C. EHRENBERGII, | “7, TETMEMORUS GIGANTEUS. “ 12, HYALOTHECA DISSILIENS. ‘i 17 SE aceon: 
« 3. C. ROSTRATUM. | “8 TETMEMORUS GRANULATUS " 18, DIDYMOPRIUM GREVICLII, ‘ 18. Seen EGHENII 
“4, C, DIANA, “9. PLEUROTAINIUM TRABECULA. “ 14. COSMARIUM BOTRYTIS | 8; SPIROGYR EBERI 
“ 5, C. PARVULUM, “10. SPIROTANIA BRYOPHILA | “15, C, CUCUMIS. ~ 20. COSM.JUNCIDUM, 


“ 21 C. MARGARITIFERUM. 


FRESH WATER ALGA. PLATE X\il 


x “: ome.) | 


APT MATUPE BY DAH. G.WOOD. SINC) AIH & SON. PMU; ADELPHIA 


Fig. 1, EUASTRUM RALFSII, 
“9, EUASTRUM ELEGANS 
v] 


| Fiy. 6. IBID VARIETY DENTICULATA, | Fig, 10. STAURASTRUM PUNCTULA- | Fig. 18. STAURASTRUM MUNITUM 
i 

EUASTRUM BINALE iy 
| 
| 


M, JENNERHH | TUM. | “14, COSMARIUM PYRAMIDATUM 


STAURASTRUM ORBICULARE. | “ 11. STAURASTRUM LEWISII {5, COSMARIUM BROOMEI, 
16, COSMARIUM COMMISSURALE 
17. XANTHIDIUM ARMATUM 


“ 49. STAURASTRUM POLYTRI 


8, 
MICRAST. DISPUTA. * 9 STAURASTPUM DEJECTUM. 
CHUM 


4 
5. MICRAST, FURCATA. 


FRESH WATER ALGA, : PLATE XIV. 
a c mS Pur DE ay 
AFTER NATURE BY DR.H C. WOOD ao) 1 SINCLAIR &S5ON PHILADELPM IA 

Fig. 1 RHYNCHONEMA ELONGATUM. Fig. 3. SPIROGYRA PROTECTA. Fig. 5. APHANOCHAETE REPENS. 
"9. RHYNCHONEMA PULCHELLUM. 4, SPIROGYRA LONGATA. “6. DRAPARNALDIA BILLINGSII, 


FRESH WATER ALGA. 


PLATE XIV. 


i & \ / 4 
| 250. 
) aan, gray 
—— ie 
AFTER NATURE BY DR.H.C. WOOD : ; CHT Ta 
Fig. 1. RHYNCHONEMA ELONGATUM. Fig. 3. SPIROGYRA PROTECTA. Fig. 5. APHANOCHAETE REPENS. 
“2. RHYNCHONEMA PULCHELLUM. | ‘4. SPIROGYRA LONGATA. (oe MDRAPARNAECIALBILEINGE ITE 


FRESH WATER ALGA. 


de 
eet ® 
5 


a 


AFTER NATURE BY DR H. GC, WOOD. 


Fig. 1. SPFIROGYRA MAJUSCULA 
2. SPIROGYRA DILUTA. 


Fig. 3. SPIROGYRA SETIFORMIS 
4. SPIROGYRA CRASSA. 
5, MESOCARPUS SCALARIS. 


Y SINCLAIR & SON, PHILADELPHIA 


Fig, 6. SPIROGYRA NYSIGNIS 
7. SPIROGYRA PARVISPORA 


« 8 ZYGNEMAINSIGNIS 


FRESH WATER ALGA. 


PLATE XVI. 


| 
k, i 
4 
i 


m3 5 a ———_—! 


oe 


AFTER NATURE BY OR.H.C.WOOD. 


Fig. 1. SIROGONIUM RETROVERSUM. 


“ 2, HYDROGASTRUM GRANULATUM. 


« 3. STIGEOCLONIUM. 


T. SINCLAIR & SON, PHILADELPHIA, 


Fig. 4. BULBOTRICHA ALBIDA. 
“ 6. BULBOCHATE CANBYII, 


“ 6, STIGEOCLONIUM. 


PLATE XVII. 


T. SINCLAIR & SON, PHILADELPHIA. 


FRESH WATER ALGA. 


AFTER N@TUARE BY DR.H.C.WOOD. 


Fig. 4, SPIROGYRA DUBIA. 


SCHIZOMERIS LEIBLEINII. 


Fig. 1. 


a 
4 
=I 
=) 
= 
wo 
iS 
= 
iz 
= es 
=e 
= 6 
a 
5 & 
(oj) 
ce 2 
ae 
Mi. 
Oo Oo 
NS oS 


FRESH WATER ALGA. PLATE XVIII. 


T. SINCLAIR & SON, PHILADELPHIA 


AFTER NATURE BY DR.H.C.wOOoD 
Fig. 1. PRINGSHEIMI! INAEQUALE. Fig. 5 BULBOCHATE IGNOTA. 


“9. OEDOGONIUM MIRABILE. “6 BULBOCHATE DUMOSA. 


“7 CONFERVA, 


« 3. OEDOGONIUM ECHINATUM. 


“ & OEDOGONIUM. 


PLATE XIX. - 


FRESH WATER ALGAE. 


T. GINOLAIR & SON, PHILADELPHIA. 


AFTER NATURE BY DA.H.C. WOOD. 


< 
« 
Oo 
a 
o 
& 
< 
2-2 
== 
<a 
an oO 
SO, 
a 
tes 
z 9 
< O- 
pe ots 
z 
oes 
so + 
os 
ra 


Fig. 1, STIGEOCLONIUM. 


“2, CHANTRANSIA EXPANSA. 


PLATE XX 
FRESH WATER ALGA. z ea Ged 


‘ T. SINCLAIR & SON, PHILADELEH ¥ 1A 
i, 
"i "AFTER NATURE BY OR. H. C. WOOD. 
Fig. 5. EVASTRUM MULTILOBATUM 
F UM Fig 3. VAUCHERIA POLYMORPHA ig. 
Fig. 1. STIGEOCLONI Fi aA State 
‘ RTHRODESMUS QUADRIDENS. “4. LEMANEA TORULOSA. | 6, PE 
Fe A) 


: : 
FRESH WATER ALGA. ; PLATE XXI. 


AFTER NATURE BY DA. H. C. WOOD T. SINOLAIR & SON, PHILADELPHIA. 
' 


Fig. 1. PLEUROTCENIUM CRENULA-| Fig. 6. COSMARIUM BREBISSONII. ' Fig lv, COSMARIUM BROOME), Fig. 17, STAURASTRUM ORBICU- 
TUM. * 7, COSMARIUM TETRAOPTHAL | © Ji. MICRASTERIAS JENNERI. ; LARE 
« 2. PLEUROTCENIUM BREVE MUM. "12. EUASTRUM ORNATUM. “ 18. ST. DEJECTUM. 
«3. TETMEMORUS BREBISSONII. “8, COSMARIUM MARGARITIFE-}| “ 13. E. DIDELTA. bes Ship, EEN ASHE, 
«4, CLOSTERIUM LINEATUM. RUM. . ipa 14. E. ELEGANS. “20, ST PARADOXICUM. 
“5, COSMARIUM BOTRYTIS. “9. COSMARIUM SUBORBICU , “ 15. MICRASTERIAS TRUNCATA, ' 71. ST ARACHNE 
“ 16. MICRASTERIAS GRANULATA.; * 22. ST RAVENELLII. 


LARE. s i 
' “23 ST. POLYTRICHUM.