UNIVERSITY of CALIFORNIA

AT

LOS ANGELES
LIBRARY

TUFTS COLLEGE STUDIES, Vol. IV., No. 7

(SCIENTIFIC SERIES No. 37)

THE GREEN ALGAE OF NORTH AMERICA,

(SECOND SUPPLEMENT.) By FRANK S. COLLINS.

PUBLISHED BY THE CHARLES HYDE OLMSTEAD FUND.

TUFTS COLLEGE, MASS.
JUNE i, 1918

LIST 01 TUFTS COLLEGE STUDIES

-hed

{Bulletin of //'..- . pp. 1-9. 1893). i Plate

am: :re.

:rr: Ectodermic Origin of th< of the

viii. pp. 506-509. 18-,
•cation of the Arthropoda «
xxviii, pp. j 18 and 220, 1894).

pment of the Lungs of Spi<
.• ' of Stienif \ S<j \}. i i

lopment of the Win.
>nii (Ame? xxviii, p. 761, 1894).

The Morphology and Classification of the
PauropoJ. i the Morphology of thi-

4 Plates.

! : drocranium in '

thia

7 '

to i

>f Am-
18. A

TUFTS COLLEGE STUDIES, Vol. IV, No. 7.

THE GREEN ALGAE OF NORTH AMERICA,

SECOND SUPPLEMENTARY PAPER.

BY FRANK S. COU<INS.

In the five years since the first supplement to the Green
Algae of North America, Vol. Ill, No. 2, of this series was
published, many species known from other countries have been
found to occur here, while to a larger extent than in the first
supplement, species and genera new to science have been dis-
covered here. The largest contributors to this increase have
been E. N. Transeau and G. M. Smith. Transeau's papers,
1913, 1914, 1915, beside a general account of the algae of the
prairie regions of Illinois, give a careful study of our Zygne-
maceae and Mesocarpaceae with many new species, and also
a number of new species of Ocdogonium. Transeau, 19133, is
a study of seasonal variation in algae, covering a period of five
years; Transeau, 1917, reports collections in Michigan in 1915.
G. M. Smith, 1916, igiGb, form a very important contribution
to the knowledge of our plankton forms, giving the results of
two years' exploration of the lakes of Wisconsin. Smith, 19163,
is a monograph of the genus Scencdesmus, intended to include
all references in print, and probably coming as near to com-
pleteness as is humanly possible. Smith, 1913, describes a new
and interesting genus ; other papers by the same author are of
special interest in other than systematic lines. It is a matter
for congratulation to all interested in the study of our fresh
water algae that two men whose names did not appear in the
original paper or its first supplement are now doing work equal
to the best anywhere. The species of Transeau and Smith
have been included here as given by them ; it is probable that,
as in all such cases, changes will later be found necessary, but
they cannot be foreseen. Borgesen, 1913, and Collins & Her-
vey, 1917, add a number of species from subtropical regions,
the former from the Danish West Indies,* the latter from Ber-

* These islands have lately been purchased by the United States, and
in the following text will be referred to by their new name, the Virgin
Islands.

56097

2 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

muda. Other authors and contributors are recorded in their
proper places.

The most important general work appearing during the past
five years is Die Siisswasser- Flora Deutschlands, Oesterrek-hs
und der Schweiz, issued by Pascher of Prag, really a series of
monographs by the best specialists of continental Europe, cov-
ering all vegetation from flowering plants down, to be found
in fresh water. Beside recording all, and figuring nearly all,
found in the regions named, it has at least references to most
species of other regions with similar conditions ; it is prac-
tically indispensable to any careful student. The student will,
however, regret that the condensed form, in one way an advan-
tage, has excluded all references to original descriptions and
most synonymy. As no citations are given, it is impossible to
determine when a combination is used for the first time, as is
certainly sometimes the case. Part V, Tetrasporales, Proto-
coccales, Part VI, Ulothricales, Microsporales, Oedogoniales,
Part IX, Zygnemales, have been issued ; Parts IV, Volvocales,
VII, Siphonales, XI, Heterokontse, are still to come.

West, 1916, contains a system of classification of all the
green algae, with characters of genera and higher divisions ;
it differs considerably in details from previous classifications.
Attention has been given to it in cases where genera not before
known in North America are now reported, but no attempt has
been made to rearrange genera already known here. In ^m
eral, specific names have not been changed from those used in
1909 and 1912, when the change was due to the dis< »
an older name than the one hitherto prevailing ; nor has record
been made of extensions of range.

Citations have been made in the same manner as in tilt-
original paper and the first supplement; all works not already
included in the lists given with those papers will be found in
the list at the end of this paper. In general the seco-nd sup-
plement follows the plan of the first, as stated on p. 70 of the
latter. No attempt has been made to revise the keys to the
genera, as a paper by the writer will soon be issued in the Tufts
College Studies, giving a general key to the genera of North

_3 j:Jb

THE GREEN ALGAE OF MOUTH AMERICA 3

American algae. The plates, illustrating all but one of the
new genera, are the work of Professor F. D. Lambert, with the
exception of the plate of Oedocladium, which is by Professor
I. F. Lewis.

Page 94, for Key to the Species of Ophiocytium, substitute,
i. Attached. 2.

i. Free. 3.

2. Cells 5-7 /u diaui., stipe 10-14 /j. long. 6. O. gracilipes.

2. Cells 3-5 M diam., stipe 2-3.5 /* long. 5. O. arbuscula,

3. Bearing a stipe or spine. 4.

3. Without stipe or spine. 7.

4. Stipe with capitate end. i. O. ntajits.

4. Stipe or spine acute. 5.

5. Spine at one end. 2. O. cochleare.

5. Spine at each end. 6.

6. Cells 12-15 f- diam. 7. O. bicuspidatum.

6. Cells 10 M diam. or less. 3. O. capital iim.

7. Cell rounded at both ends. 4. O. parvulum.

7. Cell rounded at one end, sharply truncate at the other.

8 O.truncatum.

After the description of O. CAPITATUM, add,

Var. LONGISPINUM (Mob.) Lemmermann, 1899, p. 32, PI. IV,
figs. 21-25; Rcinschiella longispina Mobitis, 1894, p. 331, PI. I,
figs- 3l~33- Cells 6-7 ju. diam., 3-4 diam. long, at first straight,
then curved, finally convolute, spine 16-50 //. long at each end.
Wis., G. M. Smith. Europe.

Page 95, after description of O. GRACILIPES, add,

7. O. BICUSPIDATUM (Borge) Lemmermann, 1899, p. 31, PI.
Ill, figs. 13-15; O. majusv&r. bicuspidatum Borge, 1894, p. 10,
PI. I, fig. 3. Cells solitary, 12-15 /"• diam., arched or spiral,
with spine 5-7 //. long at each end. Fla., Borge. Europe.

8. O. TRUNCATUM Lemmermann, 1899, p. 33, PI. IV, figs.
26-29. Cells solitary, 5-6 /u, diam., straight, arched or spiral,
one end rounded, the other sharply truncate. Harpswell,
Maine, Lambert. Europe.

Page 95, TRIBONEMA Derbes & Solier is now generally
accepted in place of CONFERVA Linnaeus.

Page 99, under CHLOROTHECIACEAE, cancel "Only one
genus represented here," also everything referring to CHARAC-
IOPSIS, and substitute as follows :

4 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

CHARACIOPSIS Borzi, 1894, p. 151.

Cells lanceolate, cylindrical, pyriform or ovoid, solitary or
gregarious, attached to plants or crustaceans by a stipe, usually
with basal disk ; chromatophores one to several, parietal, disk-
shape ; asexual reproduction by uniciliate zoospores with lateral
stigma ; in one species macro- and microzoospores ; also by
aplanospores ; sexual reproduction by zoogonidia formed 1-4 in
an aplanospore, the zygote developing 1-2 zoospores.

In habit the species of this genus closely resemble species of
CHARACIUM, but possess asexual reproduction, have zoospores
with only one cilium or with merely the rudiment of a second
cilium, and have no pyreuoid. Lemmermann, 1914, is a mono-
graph of the genus, and is here followed.

KEY TO THE SPECIES OK CHARACIOPSIS.

I. Cell with obtuse apex. 2.

i. Cell with acute or subulate apex. 6.

2. Mature cell of uniform diam. most of its length. 5. C, cylindrica.

2. Mature cell of various shape, not cylindrical. 3.

3. Cell ovoid or ellipsoid, subequally rounded above and below. 4.
3. Cell rounded above, tapering below. 5.

4. Stipe slender, with basal disk. i. (. Naegelii.

4. Stipe stout, without basal disk. 2. C. tltipsoidta.

5. Epiphytic, 15-25 M long. 3. C. Pyrifonnis.

5. Epizoic, 50-150 M long. 4. C. grocnlandica.

6. Cell more or less falcate. 8. C. subu/aia.

6. Cell not falcate. 7.

7. Stipe half to twice as long as cell. 9. C. longipei.

7. Stipe less than half as long as cell. 8.

8. Cell short-acuminate, straight at both ends. 6. C. acuta.

8. Cell long-acuminate at both ends, more or less oblique.

7. C. miHHla.

1. C. NABGBLII (A. Br.) Lemmermann, 1914, p. 253, ti^s.
io, 14; Charadum Nafgelii A. Braun in Nageli, 1849, p. 87,
PI. Ill, D, a-ra ; Collins, 1909, p. 150; Phyk. Univ., No. 492.
Cells ovoid or ellipsoid, broadly rounded at each end, 20-42 X
7-18/4, stipe 3-4 n long, with capitate base but no disk ; chro-
matophore single; zoospores numerous, escaping laterally.
Mass., Pa., Neb. Europe.

2. C. KLLiPSpiDBA G. S. West, 1905, p. 288, PI. CCCCLX 1 V,
fig. 8, a-c ; Collins, 1909, p. 100; Lemmermann, 1914, p. 253.
Cells narrowly ellipsoid, obtusely rounded at each end, 15-22 X
8-10/4; stipe very short and straight, not capitate; chromato-
phores 2-4. Barbados.

THE GREEN ALGAE OF NORTH AMERICA 5

3. C. PYRIFORMIS (A. Br.) Borzi, 1894, p. 153 ; G. M. Smith,
igi6b, p. 563 ; Characium pyriforme A. Brattn, 1855, p. 40, Pi.
V. B. Cells obovoid with broadly rounded apex, base attenuate
into a capitate stipe, 9-13 /* long; total length of cell 18-25/1,
width 5-12 /*; chromatophores 1-4. Wis. Europe ', Africa.

Var. SUBSESSIUS Lemmermann, 1914, p. 254, fig. il. C.
minuta P. B.-A., No. 1369. Smaller, cell 13-16 X 4-5 /"• ; stipe
very short, 1.5-2 /A; chromatophore single. Cal. Europe.

4. C. GROENI.ANDICA (P. Richter) Lemmermann, 1914, p.
255 ; Characium grocnlandicum P. Richter, 1897, p. 6. Cell
claviform or subfusiform, apex straight or more often slightly
curved, rounded, base gradually attenuate into non-capitate
stipe. Cells 50-150 X 7-25 /*, stipe about 12 /u. long ; chromato-
phore single ; zoospores numerous. On crustaceans. Greenland.

5. C. CYLINDRICA (Lambert) Lemmermann, 1914, p. 256 ;
Characium cylindricum Lambert, 1909, p. 65, PI. LXXIX, figs,
i, 2, 7, 8, 10-13, 23-25; Collins, 1909, p. 151; P. B.-A., No.
1269. Cell cylindrical with rounded apex and tapering base,
24-430 X 10-20 p., stipe short, without basal disk ; chromato-
phores two; macrozoospores 8-16, escaping by a lateral open-
ing, microzoospores numerous, escaping by an apical opening.
Mass.

6. C. ACUTA (A. Br.) Borzi, 1894, p. 153; Collins, 1909,
p. 99; Lemmermann, 1914, p. 257 ; Charadcum acutum A. Braun,
1855, p. 41, PI. V. C. ; Wolle, 1887, p. 177, PI. CLIX, fig. 2 ;
Wittr. & Nordst., No. 1236. Cell ovoid or broadly fusiform,
short-acuminate at each end, 20-38 X 6-10/1, stipe 3-4^ long,
with basal disk ; chromatophores 1-2 ; zoospores escaping by
apical opening. Pa. Europe.

7. C. MINUTA (A. Br.) Borzi, 1894, p. 152 (as to name only) ;
Collins, 1909, p. 99 ; Lemmermann, 1914, p. 257, figs. 4-5 ;
Characium minutum A. Braun in Kiitzing, 1849, p. 892 ; 1855,
p. 46, PI. V. F. ; P. B.-A., No. 1221. Cell lanceolate, straight
or very slightly curved, ending in a short, curved apiculum,
base gradually attenuate into a short stipe with disk ; cells
12-38 X 3-8 p. ; chromatophore single; zoospores 4-8, escaping
by an apical opening. Mass., Cal.

Europe, So. America, Australia, etc.

Collins, 1900, fig. 6, does not represent this species, but C.
turgida W. & G. S. West, which has not yet been found in this
country. Borzi having first used the binominal Characiopsis
minuta, his name must be retained as author, although the
plant described and figured by him, 1894, p. 152, PI. XIV, figs.

6 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

i- 1 2, is not, as he supposed, Charm inm minuium A. Braun, but
a then undescribed species, now Characiopsis Borziana Lemmer-
mann, 1914, p. 256.

8. C. SUBULATA (A. Br.) Borzi, 1894, p. 152 ; Collins, 1909,
p. 100; Leuimermann, 1914, p. 258, fig. 3; P. B.-A., No. 1370;
Characium subulatum A. Brauii, 1855, p. 41, PI. V. C. Cell of
oblique lanceolate or falcate outline, gradually attenuate from
near the base to the acute apex, shortly attenuate to the very
short, capitate stipe, 10-20 X 4-6 /t ; chromatophore single ;
zoospores 2-4. Cal. Europe.

P. B.-A., No. 1370, contains, along with this species, some
C. minuta (A. Br.) Borzi.

9. C. LONGIPES (Rab.) Borzi, 1894, p. 152; Lemmermann,
1914, p. 259; Characium longipes Rabenhorst, Dec. 18, No. 171,
1852 ; in A. Braun, 1855, p. 42, PI. V. D. Cell suberect or
inclined, narrowly or broadly lanceolate, ending in a somewhat
oblique apiculum ; stipe from half to twice as long as the cell,
with basal disk. Wis., G. M. Smith. Europe.

PERONIKLLA Gobi, 1887, p. 244.

Cell ovoid, pyriform or subglobose at maturity, living in the
gelatinous coating of filamentous desmids, attached to the cells
by a slender stipe with basal disk. Asexual reproduction by
(uniciliate ?) zoospores.

P. PLANCTONICA G. M. Smith, 1916, p. 476, PI. XXV, fig.
15. Cells ovoid-pyriform, 6-9.5 /* l°ng« stipe '8-10 ^ long, zoos-
pores 2-4 in a cell. In coating of Sphaerozosma. Fig. i.
Wis., G. M. Smith.

P. Hyalothccae Gobi, inhabiting Hyalothcca mucosa in Europe,
is to be looked for on the same host here. It is somewhat
larger, 7-10 /* diatn., stipe 13-15 /• long, and has usually 8
zoospores in a cell.

MISCHOCOCCUS Nageli, 1849, p. 82.

Cells globular, united by thick tubular gelatinous sheaths to
form branched colonies; cells only at ends of sheaths; each
cell with 1-4 chromatophores ; sexual reproduction by isogam-
ous gametes, the zygospore dividing to form an epiphytic
cushion ; asexual reproduction by zoospores germinating
directly. Only one species.

M. CONFBRVICOLA Njigeli, 1849, p. 82, PI. II. D. Cells
3.5-5.5 M diam. Fig. 2. Wis., G. M. Smith. Europe.

THE GREEN AUJAE OF NORTH AMERICA 7

Page 102, for Key to the Species of Zygneraa substitute,

i. Spore formed in the tube. Sect. PECTINATA. 2.

i. Spore usually formed in one of the cells. 6.

2. Spore with thick, lamellate membrane. 2. Z. pachydermum.

2. Spore without thick, lamellate membrane. 3.

3. Spore bluish. 3. Z. cyanospermum.

3. Spore brownish. 4.

4. Spore smooth. 14. Z. ericetorum.

4. Spore pitted. 5.

5. Cells 30-50 n diam. i. Z. pedinatum.

5. Cells 18-25 M diam. 9- Z. decussatum.

6. Spore with smooth median membrane. Sect. L,EIOSPERMA. 7.

6. Spore with pitted median membrane. Sect. SCROBICUI.ATA. 10.
7. Vegetative filaments 20-22 n diam. 5. Z, leiospermum.

7. Vegetative filaments over 26 M diam. 8.

8. Vegetative filaments 35-54 M diam.

7. Z. cruciatum forma leiospermum,

8. Vegetative filaments 26-33 V- diam. 9.

9. Zygospores unknown ; aplanospores cylindric, filling the cell.

ii. Z. cylindricum.
9. Zygospores globose or broadly ovoid, 30-32 M diam. 6. Z. insigne.

10. Spore bluish. n.

10. Spore brown. 13.

ii. Fertile cells not swollen. 7. Z. cruciatum var. coeruleum.

ir. Fertile cells swollen on the inner side. 12.

12. Spore globose to oblong, 26-40 n diam. and length; aplanospores
cylindric-oblong, 18-24 A* diam. ; both with large pits.

13. Z. Collinsianum .

12. Spore subglobose, 33 /x diam., no aplanospores ; spore finely scro-

biculate. 10. Z. peliosporum.

T3- Vegetative cells 35-54 M diam. 7. Z. cruciatum.

13. Vegetative cells 22-36 M diam. 14.

14. Spore produced by union of contiguous cells in a filament through
the partition wall. 12. Z. rhynchonema.

14. Conjugation scalariform. 8. Z. stellinum.

Page 103, after description of Z. PECTINATUM, insert,

Var. CRASSUM Transeau, 1915, p. 21. Vegetative cells
30-40 /A diam., spores 40-55 X 50-60 /A. 111.

Var. CONSPICUUM (Hass.) Kirchner, 1878, p. 127; Tynda-
ridea conspicua Hassall, 1845, p. 164, PI. XXXIX, figs. 1-2.
Vegetative cells 18-27 P- diam ; membrane thick and lamellose.
111.

Page 104, cancel No. 4, Z. CHALYBEOSPERMUM.

After description of Z. CRUCIATUM, insert,

8 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

Var. COBRULEUM Transeau, 1915, p. 22. Median membrane
of spores steel-blue. 111.

Under Z. INSIGNE, cancel, P. B.-A., No. 457.
Page 103, cancel var. DECUSSATUM.
Page 105, after first three lines, add,

9. Z. DECUSSATUM (Vauch.) Agardh', 1817, p. XXXII;
Transeau, 1914, p. 290; Z. pectinatum var. decussatum Collins,
1909, p. 103 ; Conjugata dccussata Vaucher, 1803, p. 76, PI. \ II,
fig. 3. Vegetative cells 18-20 /* diam., cells 3-5 diam. long, mem-
brane not specially thickened ; spores 27-30 /i diam. Mass.,
Ill: Europe.

10. Z. PELIOSPORUM Wittrock, 1868, p. 188 ; Transeau,
1915, p. 21. Vegetative cells 24 p. diam., 1-3 diam. long; fer-
tile cells swollen on the inner side ; spores subglobose, 33 /*
diam., dark blue, median membrane scrobiculate. Cal., Colo.,
Vancouver. Europe.

P. B.-A., No. 808 ; Tilden, Amer. Algae, Nos. 156, 392, all
distributed as '/.. chalybtospermum, belong to this species.
There seems to be no certain record for /.. chalybcosperntum in
this country.

11. Z. CYLINDRICUM Transeau, 1915, p. 22. Vegetative
cells 28-33 /* diam., 1-2 diam. long ; zygospores unknown ;
aplanospores cylindric or tumid-cylindric, filling the cell,
30-33 X 24-58 ft, median membrane brown, scrobiculate. 111.

12. Z. RHYNCHONEMA Hansgirg. i888a, p. 257; Transeau,
1915, p. 22. Vegetative cells usually 12/1, sometimes 16-20/1
diam., cells 2-6 diam. long; conjugation always lateral, spores
subglobose, about 33 /* diam.

The dimensions given above are for the European, typical,
form ; the specimens from Vancouver, attributed to this species,
have cells 22-28/4 diam., 1-2 diam. long; the zygospores are
ovoid, 24-28 X 36-44 p., and the conjugation took place through
the partition wall. Aplanospores also occurred, globose, 24-26
n diam.

13. Z. COLLINSIANUM Transeau, 1914, p. 289, PI. XXV,
figs. 1-3. Vegetative cells 18-24 M diam., 2-3 diam. long, fertile
cells swollen on the inner side ; zygospores globose, 26-40 /*
diam., or oblong. 26-40 X 30-47 /*. median membrane blue,
with large pits; aplanospores cylindrical-oblong, 18-24 X
40-76 M. scattered among the vegetative cells, color and mark-
ings as in the zygospores. III.

THE GREEN ALGAE OP NORTH AMERICA 9

14. Z. ERICETORUM (Kiitz.) Hansgirg, 1886, p. 155 ; Zygo-
gonium ericetorum Collins, 1909, p. 120, with description. Re-
cent investigations have shown that the distinction between
Zygncma and Zygogonium cannot be maintained. Var. TER-
RESTRE becomes ZYGNEMA ERICETORUM var. TERRESTRE
Kirchner, 1878, p. 127.

Page 105, for Key to the Species of Spirogyra, substitute,
i. Cell conjugating directly, not by a tube. 2.

i. Cell emitting a tube. 4.

2. Filaments 38-54 M diam., spore up to 60 /x. 58. S. stictica.

2. Filaments 56-85 M diam., spore 75-115 M. 3-

3. Fertile cells much inflated, up to 135 M- 55- S. florid ana.

3. Fertile cells only slightly inflated. 54. S. illinoiscnsis.

4. Dissepiments plane. 5.

4. Dissepiments largely'replicate. 48.

5. Chrotnatophore mostly single. 6.

5. Chromatophores two or more. 27.

6. Spore membrane punctate. 7.

6. Spore membrane smooth. .11.

7. Fertile cells not distinctly swollen. 41. S. daedalea.

7. Fertile cells distinctly swollen. 8.

8. Conjugating tube from both cells. 5. S.variansv&r.scrobictilata.

8. Conjugating tube always or usually from male cell. 9.

9. Fertile cells inflated on tube side only. 56. 5". micropunctata.

9. Fertile cells inflated on both sides. 10.

10. Spore about 36 M diam. 27. S. punctata.

10. Spore 40-48 p. diam. 50. S. punctifornris.

ii. Fertile cells not distinctly swollen. 12.

ii. Fertile cells distinctly swollen. 17.

12. Cells less than 30 M diam. 13.

12. Cells 30 fj. diam. or more. 15.

13. Spore ovoid, slightly longer than the diam. ; cells 22-25 M diam.

9. 5. subsalsa.
13. Spore ellipsoid, 2-3 times longer than the diam. . 14.

14. Chromatophore slender, with inconspicuous pyrenoids.

7. S. communis.

14. Chromatophore broad. i. S. longata.

14. Chromatophore slender, with many large, distinct pyrenoids.

3. S. Juergensii.

15. Cells 30-48 fM diam. 16.

15. Cells 48-70 M diam. 8. S. condensata.

16. Cells seldom reaching 35 /u diam. ; chrouiatophore slender.

38a. S. Lagerheimii.

16. Cells 40-48 n diam. ; Chromatophore broad, dentate.

2. S. porticdlis.

TUFTS COLLEGE STUDIES, VOL. IV, No. 7

17. Fertile cells swollen on one side only.
17. Fertile cells swollen on both sides.

18. Cells less than 25 M diam.

18. Cells over 30 M diam.

18.

21.

5. gracilis.
19-

19. Cells 40-48 M diam. ; spores marked with a longitudinal line.

39. S. circumlineata.

19. Cells under 40 M diam. ; spore without line.

20. Fertile cells swollen on the tube side.

20. Fertile cells swollen on the outer side.
21. Fertile cell reflexed.
21 Fertile cell not reflexed.

22. Chroniatophore slender.

22. Chromatophore broad.
23. Cells 27-30 M diam., spore 30-33 X 33-45 M.
23. Cells 40-45 M diam., spore about 47 M diam

20.

5. S. rations.

40. S. Borgeana.

57. 5. reftexa.

22.

23-
24.

1 8. S. affinis.
of varying shape.

6. S.fusco-atra.
20. S. flavescens.
25-

24. Cells under 15 M diam.

24. Cells over 17 M diam.
25. Cells with twochromatophores frequent ; sterile cells often inflated.

47. S. pratfttsis.
25. Chromatophore always single. 26.

26. No zygospores ; aplanospores 24-26 X 38-50/1. 19. S. tnirabilis.

26. Zygospores regularly produced. 4. S. catenaeformis.

27. Chromatophores two, rarely three. 28.

27. Chromatophores regularly three or more. 30.

28. Spore membrane scrobiculate. 42. S. velata.

28. Spore membrane smooth. 29.

29. "Cells 21-40 ft diam. 66.

29. Cells 43-50 ft diam. 26. S. dubia.

30. Spore lenticular. 31.

30. Spore ovoid, ellipsoid or subglobose.
31. Cells 1 20 M diam. or more.

31. Cells 1 10 /i or less.

32. Spore membrane pitted.

32. Spore membrane smooth.
33. Fertile cells little or not swollen.
33. Fertile cells distinctly swollen.

34. Spore a»>out 72 n diam., 48 M thick.

31. Spore 70-110 /i diam., 50-75 n thick.
35. Cells 90-163/1 diam.

35. Cells 80 M diam. or less.

36. Cells over 125 M diam.

36. Cells 1 10 M diam. or less.
37. Spore compressed. 38.

37. Spore not compressed. 46. S. ellipsospora.

if..

35-

S. »/n \ i >it,i.

32-

58. S. kydrodictya.
33-
34-

25. 5. bfltis.

15. S. orthospira.

45. S. submaxima.

36-

41.

37-

39-

THE GREEN ALGAE OF NORTH AMERICA i

38. Spore compressed oval. 17. S. crassa.

38. Spore compressed ellipsoid ; ends pointed in edge view.

46. 5". ellipsospora var. crassoidea.

39. Spore compressed. 17. 5. crassa var. formosa.

39. Spore not compressed. 40.

40. Cells loo-no n diatn. ; chromatophores 4-8. 13. S. setiformis.

40. Cells 90-100 /* diam. ; chromatophores 3-4. 12. S.jugalis.

41. Cells less than 40 yu diam. 42.

41. Cells 50-80 At diam. 43.

42. Chromatophores four. 24. 5". fluviatilis.

42. Chromatophores 3, rarely 2 ; of brackish water.

10. S. submarina.

43. Spore punctate or scrobiculate. 44.

43. Spore smooth. 45.

44. 3 chromatophores, making half to one turn. 48. S. propia.

44. 3-5 chromatophores, making two and a half to four turns.

49. S. novae-angliae.

45. Cells 50-65 a diam. 23. S. neglecta.

45. Cells 70-78 M diam. 46.

46. Spore 60-72 M diam. 47.

46. Spore about 50 /u. diam. 14. S. parvispora.

47. Spore verrucose, ovoid. 44. S. dilula.

47. Spore smooth, ellipsoid and tapering. n. .S. nitida.

48. Replicate and plain walls about equal in number.

6 r. S. fallax.

48. Plain walls rare and exceptional. 49.

49. Replication an entire ring. 50.

49. Replication forming half a ring. 51. S. narcissana.

50. Chrouiatophore single, rarely two. 52.-

50. Chromatophores two or more. 51.

51. Membrane reticulate. 59. S. reticulata.

51. Membrane smooth. 64.

52. Membrane punctate or areolate. 53.

52. Membrane smooth. 57.

53. Cells 30 M diam. or more. 54.

53. Cells 24 M diam. or less. 55.

54. Membrane areolate. 60. 5. areolata.

54. Membrane punctate. 37. S. protecta.

55. Chromatophores slender; cells 12 n diam. or less.

28. 5". tenuissitna var. rugosa.
55. Chromatophores broad ; cells 15 M diam. or more. 56.

56. Cells 15-18 A* diam. ; spores scrobiculate.

29. S. inflata v&r.foveolata.

56. Cells 22-24 ** diam. ; spores punctate or granulate.

43. S. Goetzii.

iz TUFTS COLLEGE STUDIES, VOL. IV, No. 7

57. Fertile cells little if any swollen. 32. S. Weberi.

57. Fertile cells distinctly swollen. gft.

58. Cells 9-23 M diatn. 59.

58. Cells 24-33 M diam. 62.

59. Inflation cylindrical. 34. S. groenlandica.

59. Inflation rounded or tapering at the ends. 60.

60. Cells 12 M diam. or less. 28. 5. fenuissittia.

60. Cells 15 M diatn. or more. 61.

6l. Chromatophore broad ; cells 3-8 diam. long. 29. />. inflata.

61. Chromatophore slender ; cells 10-25 diam. long. 30. S.Spreeiana.

62. Fertile cells with quadrate swelling. 31. S. quatirafa.

62. Fertile cells with rounded swelling. 63.

63. Spore o%'oid, 30-36 M diam. 33. S. Grtvilltana.

63. Spore ellipsoid, ends more or less pointed, 32-45 M diam.

53. S. Farloii'ii.

64. Cells 35 M diam. or less. 35. S. Hassallii.

64. Cells 39-42 M diam. 65.

65. Fertile cells shortened and swollen. 36. S. insignis.

65. Fertile cells with quadrate swelling. 52. S. rcetangularis.

66. Chromatophores quite broad. 10. A" decimina.

66. Chromatophores very slender. 63. S. irrtgularis.

Page 71 of supplement, cancel beginning, " Page 107, for No.
34" and all of page 72 to line ending "23. S. NBGLBCTA."
Page 107, under S. LONGATA, cancel P. B.-A., No. 510.
Page 108, under S. PORTICALIS, cancel P. B.-A., No. 365.
After description of S. CATENABFORMIS, add,

Var. PA UVULA Transeau, 1914, p. 292, PI. XXVI, figs. 3-4.
Filaments usually scattered ; vegetative cells 20-24 X 50-105 /*,
chromatophore single, making 1-6 turns; fertile cells inil.it..1..
up to 37 M; conjugation mostly lateral, sometimes scalariform ;
spores yellow, elliptical, 20-27 X 40-60 p. 111.

Page 109, after description of S. VARIANS, add,

Var. MINOR Teodoresco, 1908, p. 188; Transeau, 1915, p. 23.
Cells 28-30/1 diam. ; spores 26-33 ft diam. Mass., 111. Europe.

Var. SCKOBICULATA Stockmayer, fide Transeau, 1915. p. 23.
Spores scrobiculate. 111.

Under S. COMMUNIS, cancel P. B.-A., No. 1416.
Under S. CONDBNSATA, add, The typical form occurs in Mass.
Page no, change S. DECIMINA var. SUBMARINA to S. SUB-
MARINA (Collins) Transeau, 1915, p. 25.
Under S. NITIDA. cancel P. B.-A., No. 513.

THE GREEN ALGAE OF NORTH AMERICA 13

Page in, cancel reference to S. diluta Wood.
Page 113, after description of S. CRASSA, add,
Var. FORMOSA Transeau, 1915, p. 27. Slender, cells 80-95 X
80-270/1, spores 88-110 X 120-150 X 70-90/1. 111.

Page 114. The specimens from Mass, and Washington re-
ferred to S. IOJTETIANA seem rather to belong to S. FALLAX
(Hansg.) Wille. Wolle's somewhat doubtful record is now
the only one for America.

Under S. FLUVIATHJS, add, spores brown, scrobiculate.

Page 115, under S. DUBIA var. LONGIARTICULATA, cancel
P. B.-A., No. 961.

Under S. TENUISSIMA, cancel, P. B.-A., No. 456.

Page 116, after description of S. TENUISSIMA, add,

Var. RUGOSA Transeau, 1914, p. 291 ; P. B.-A., No. 456.
Cells 1 1-13 /u. diani. ; spores 28-32 X 55-64 p., membrane minutely
pitted. Mass., R. I., N. J., 111.

Under S. INFLATA, cancel P. B.-A., No. 363. Add,
Var. FOVEOLATA Transeau, 1914, p. 291. Spore membrane
scrobiculate. 111. ,;

P. 117, under S. GREVII^EANA, cancel P. B.-A., No. 362.
P. 119, after paragraph on S. ELONGATA, add,

383. S. LAGERHEIMII Wittrock in Wittrock & Nordstedt,
Alg. Exsicc., No. 961, 1889, with figure; .S". porticalis var.
tenuispora Collins, 1912, p. 72. Cells 27-33 \L diam., 3-5 diam.
long ; dissepiments not replicate ; chromatophore single, 2.5-3.5
turns ; vegetative cells among fertile cells more or less swollen,
fertile cells slightly swollen on tube side ; spores ellipsoid with
pointed ends, 25-31 X 48-66/4, light brown; membrane finely
punctate. Mass., N. H., 111. Europe.

39. S. CIRCUMLINEATA Trauseau, 1914, p. .293, PI. XXVI,
figs. 5-6. Cells 40-48 p. diam., 120-240/1 long; dissepiments
plane ; chromatophore one, making 4-8 turns ; fertile cell
swollen on tube side only ; spores ellipsoid, 40-50 X 70-125 //.,
yellowish brown, outer wall marked by a more or less distinct
longitudinal line. 111.

40. S. BORGEANA Transeau, 1915. p. 23. Filaments 30-35 /*
diam., cells 50-200 /* long ; dissepiments plane; one chromato-
phore, making 1.5-5 turns; fertile cells inflated on the outer
side, straight on the inner side ; spores ellipsoid, 33-40 X
54-70 fj., yellow, smooth. 111.

14 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

41. S. DAEDALEA Lagerheim, 1888, p. 592 ; Transeau, 1915,
p. 24. Filaments 33-36 /i diam., cells 5-8 diam. long; dissepi-
ments plane; chromatophore single, making 2-3.5 turns ; fertile
cell little or not swollen, somewhat shortened ; spores ellipsoid,
36-45 X 75-120/1, brown, membrane with flexuous groovings.
Mass., 111. Europe.

42. S. VELATA Nordstedt, 1873, p. i, PI. I; Petit, 1880,
p. 24, PI. VII, figs. 1-5. Filaments scattered among other
algae; cells 29-41/1 diam., 2-4 diam. long; dissepiments not
replicate; chromatophore single, rarely two, making 1.5-6
turns : fertile cells slightly swollen ; spores ovoid to cylindric-
ovoid, 35-45 X 60-90/1, brown; membrane scrobiculate. Mid-
dlesex Fells, Mass., Lambert. Europe.

Var. OCCIDENTALS Transeau, 1914, p. 294, PI. XXVI, figs.
8-9; P. B.-A., No. 961. Cells up to 53 /i diam., chromato-
phores 1-3; spores yellowish brown. 111., Transeau; Van-
couver, Gardner.

Differs from the typical form by the larger filaments, larger
number of chromatophores, and the lighter color of the spores.

43. S. GOETZII Schmidle, 1901, p. 251, PI. IV, fig. 8;
Transeau, 1915, p. 25. Filaments 22-24 /» diam., cells 9-10
diam. long ; dissepiments replicate ; chromatophore one, with
many pyrenoids and dentate margin, making 5-6 turns; fertile
cells somewhat shorter and swollen, to 32 /i diam. ; spores ellip-
soid, 28-30 X 42-56 /i, red-brown, membrane finely punctate or
granulate. Mass. Africa.

A single collection at Welfleet, Mass., by Charles Hullard, is
the only record for the species outside of Africa.

44. S. DILUTA Wood, 18693, p. 139; 1872, p. 170, PI. XV,
fig. 2; Transeau. 1915, p. 27; P. B.-A., No. 513. Filaments
70-80 /i diam., cells 1-1.5 diam. long, dissepiments plane, fertile
cells not swollen ; chromatophores about 5, narrow, with many
pyrenoids, making '_• to i turn ; spores ovoid, about 60 /i diam..
1.5-2 diam. long, dark brown, membrane verruculose or some-
what reticulate. Mass., Conn., N. Y., Pa.

Hitherto confused with 5*. nitida, this species seems amply
distinct by the short cells, the shape and color of the spores,
and the markings of the median membrane.

45. S. sniMAxiMA Transeau, 1914, p. 295, PI. XXVII, figs.
3-4. Cells 70- 1 10 x 100-300/1; dissepiments plane ; chromato-
phores 8-9, making .1-1 turn; fertile cells slightly or not in-
flated ; spores lenticular, brown, 70-1 10 /i diam., 50-75 /i thick ;
membrane smooth. Usually forming dark brown, lubricous

THE GREEN ALGAE OF NORTH AMERICA 15

masses; often with thick, pectose sheath, up to 17 /A thick.
Mass., 111.

46. S. ELLIPSOSPORA Transeau, 1914, p. 294, PI. XXVII,
fig. i ; 1915, p. 25. Filaments dark green, lubricous ; veg. cells
[25-150 X 125-500/1; dissepiments plane ; chromatophores 3-8,
making ^-4 turns; spores ellipsoid with more or less pointed
ends, 100-140 X 160-255 /A. Me., Mass., 111., Minn.

Var. CRASSOIDEA Transeau, 1914, p. 295, PI. XXVII, fig. 2.
Cells 140-150 X 140-560 /A; spores compressed ellipsoid, ends
broadly rounded in one position, sharply pointed in another,
120-140 X H5-255 /"• Hi-
Differs from the typical form chiefly in the shape of the spore.

47. S. PRATENSIS Transeau, 1914, p. 292, PI. XXV, figs.
12-14; PI- XXVI, figs. 1-2. Forming yellowish green masses;
cells 17-20 X 80-240 fj., dissepiments plane ; chromatophores 1-2,
making r-8 turns; fertile cells inflated, up to 55 ft ; sterile cells
cylindrical, inflated or bullate (up to 90 /K) ; zygospores ovoid,
ellipsoid or cylindrical with rounded ends, 24-46 X 50-70 /A,
yellow, membrane smooth ; aplanospores similar to zygospores.
I'll.

48. S. PROPIA Transeau, 1915, p. 25. Cells 60-68 X
80-150 /A, dissepiments plane; chromatophores 3, making .5-1
turn ; fertile cells cylindrical ; spores ellipsoid, 42-60 X 80- 120 p. ;
yellow brown, membrane irregularly pitted. 111.

49. S. NOVAE-ANGLIAE Trauseau, 1915, p. 26. Cells
50-60 X 200-350 ft. ; dissepiments plane ; chromatophores 3-5,
making 2.5-4.5 turns; fertile cells not inflated; spores ovoid,
50-65 X 80-120 /A, yellow, membrane reticulate and densely
punctate. Mass., 111.

50. S. PUNCTIFORMIS Transeau, 1914, p. 294, PI. XXVI,
fig. 7. Filaments usually scattered; cells 27-30 X 120-390^1;
dissepiments plane : chromatophores 1-2, narrow, making 3-6
turns; fertile cells inflated, 44-50^; male cells 90-140 /A long,
female cells 100-250 p. long ; occurring singly or in pairs, alter-
nating with vegetative cells ; tube usually produced by male
cells ; spores ovoid to cylindric-ovoid, 40-48 X 60-110 /A, yellow,
membrane punctate. 111.

51. S. NARCISSANA Transeau, 1914, p. 290, PI. XXV, figs.
4-6. Filaments usually scattered; cells 12-14 X 200-400 /A;
one chromatophore, slender, making 2-5 turns; dissepiments
semi-replicate ; fertile cells much inflated towards the middle,
rounded or quadrate in outline, up to 33 /u.diam., not shortened ;
zygospores unknown ; aplanospores ellipsoid to ovoid, 23-30 X
50 1 20 /A, yellow, membrane smooth. 111.

16 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

The replication is unique in character ; occupying only 180°
on each side of a dissepiment, alternating on the two sides.

52. S. RKCTANGULARIS Transeau, 1914, p. 291, PI. XXV,
figs. 9-1 1. Filaments usually scattered ; cells 35-40 X 150-320/1,
dissepiments replicate ; chromatophores 2-4, making 2-5 turns ;
fertile cells quadrately inflated towards the middle, up to 70 /t
diam ; spores ovoid to cyliudric-ovoid with rounded ends,
45-65 X 75-120/1, yellowish brown, membrane smooth. 111.

53. S. FARLOWII Transeau, 1915, p. 29; P. B.-A., No. 362.
Cells 24-30 X 70-180/1; dissepiments replicate; one, rarely two
chromatophores, making 2.5-6 turns ; fertile cells inflated to
39-60 /i ; spores ellipsoid, ends more or less pointed, 32-45 X
48-93 /i, yellow, smooth. Mass.

Apparently much of the material that has passed in New
England for S. Grtvilltana, comes nearer to this species, of
which the ellipsoid spores with pointed ends constitute the most
distinctive character.

54. S. ILLINOISBNSIS Transeau, 1914, p. 296, PI. XXVIII,
1'3- Forming dull green tangled masses; cells 65-85 X

100-300/4; dissepiments plane; chromatophores 6-9, narrow,
nearly straight and longitudinal, or spiral and making .1-1
turn ; conjugating cells shortened and somewhat inflated and
geniculate ; tube short and broad ; male cells shorter than
female; spores 85-115 X 140-190 /i, ovoid to ellipsoid, yellow,
membrane thick and punctate. 111.

55. S. FLORIDANA Transeau, 1915, p. 30. Cells 56-66 X
'20-335 /i; dissepiments plane; chromatophores 4-5, nearly
straight or making a half turn ; conjugating cells geniculate,
shortened; fertile cells inflated, up to 135^; tube very short
and broad ; spores ellipsoid, 75-105 X 95-135 /*, yellow, smooth.
Fla.

56. S. MICROPUNCTATA Transeau, 1915, p. 27. Cells 30- 36 X
120-300/1; dissepiments plane; one chromatophore, making
3-7 turns ; fertile cells scattered in twos or fours among vegeta-
tive cells, or continuous, inflated on the tube side, outer side
straight ; tubes formed almost wholly by the male cell ; spores
ellipsoid, 37-42 X 57-70 /i, yellow, membrane minutely punctate.
N. H., III.

57. S. RKPLRXA Transeau, 1915, p. 28. Cells 30-40 X
120- 300/1; dissepiments plane; chromatophore single, making
3-8 turns ; fertile cells in groups of 2 or 4, inflated or strongly
reflexed ; tube formed by male cell ; spores ellipsoid, 44-54 X
90-150 /i, yellow-brown, smooth- 111.

THE GREEN ALGAE OF NORTH AMERICA 17

58. S. HYDRODICTYA Transeau, 1915, p. 28. Cells 75-100 X
210-360/4; dissepiments plane; chromatophores 7-10, either
straight or spiral, and making one-tenth to one-half turn ; fer-
tile cells more or less inflated ; tube formed by the male cell ;
spores lenticular or globose-lenticular, 80-120 X 110-195 /"*•
brown, membrane pitted. 111.

59. S. RETICULATA Nordstedt in Wittrock & Nordstedt,
Alg. Exsicc., No- 362; De Toni, 1889, p. 774. Filaments
28-40- fj. diani., cells 4-11 diam. long; dissepiments usually
replicate ; chromatophores 1-3, usually 2, making about 4
turns ; fertile cells somewhat swollen at the middle ; spores
ovate-ellipsoid, 46-56 X 80-108 //., yellow, membrane irregularly
reticulate. Mass., Fla. Brazil.

60. S. AREO^ATA L,agerheim, 1883, p. 56, PI. I, figs. 18-20.
Filaments about 36 ^ diam. ; cells 5-9 diam. long ; dissepiments
replicate; chromatophores 1-2, making 4-9 turns; fertile cells
swollen; spores ovoid or rarely globose, 45-57 X 60-120 //,,
brownish yellow ; membrane densely areolate. Me. Europe.

61. S. FALLAX (Hansg.) Wille, 1900, p. 16, Pi. I, figs. 19-
26; Transeau, 1915, p. 30; 6". insignis var. fallax Hansgirg,
i888a, p. 253 ; £. inconstant Collins, 1912, p. 73 ; P. B.-A., Nos.
1768, 1570, 1571. Cells 33-45 p- diam., 2-8 diam. long ; dissepi-
ments partly replicate, partly plane ; chromatophores 3-4,
slender, with many pyrenoids, straight or slightly spiral ; con-
jugating tube formed by male cell ; female cell much swollen ;
spores ellipsoid, 45-80 X 75- 140 /A, brown, membrane with net-
work of fine raised lines. Mass., 111. Europe.

Transeau's disposition under this species of forms attributed
to three other species is followed here, as the best in our pres-
ent state of knowledge of them. It is quite likely that there
may be changes when more is known. As noted by Transeau,
1915, p. 24, it is doubtful if 6". luteliana occurs in America ; all
references so far appear to refer to the present species. G. A.
Hill, I9i6a, p. 247 has a note on 51. lutetiana, apparently made
from sterile material, and based on the description in Collins,
19°9, P- IJ4- While the identification is doubtful, the observa-
tions on the chromatophores are interesting, indicating that in
Spirogyra species with normally one spiral this may grow
rapidly, turn back from the dissepiment and continue growing,
afterwards breaking apart, when the appearance is quite that
of two normal and distinct chromatophores.

i8 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

62. S. ikKKt.i LAKIS Nageli in Kiit/ing, 1849, p. 440;
18553, p. 7, PI. XXII, fig. n. Pale or dirty green, little lu-
bricous; vegetative cells cylindrical, 32-36 /* diam., 3^2-7 diain.
long ; dissepiments plane ; fertile cells scarcely swollen ; chro-
matophores 2-3, very slender, with large, nodulose, distant
pyrenoids, making three-fourths to one turn in a cell ; spores
32-36 /* diam., i%-2 diam. long. Charleston, 111., Trauseau.

Europe.

Spirogyra gigantica Grace A. Hill, 1916, p. 198, is founded
on a sterile plant resembling 5". crassa, but with somewhat
larger filaments, 173-188 p. against 150-160; chromatophores
making more turns to the cell ; pyrenoids somewhat larger.
The dimensions of 5". crassa are probably taken from Collins,
'9°9. P- "3. but MISS HM apparently overlooked p. 105 of the
same paper. " Specific distinctions not always clear, based on
the character of the dissepiments, the number and breadth of
the chromatophores, the size and form of the spore, the charac-
ter of its median membrane, the inflation of the fertile cell, and,
too often, the dimensions of the filaments ; this last character
being too uncertain to have much weight, except when asso-
ciated uniformly with other characters."

The specific name proposed appears to sin against the inter
national rules of botanical nomenclature, Chapter I, Art. 7.
"Scientific names are in Latin for all groups." Gigantfus is
good Latin, and has frequently been used as a specific name :
there appears to be no authority for giganticus.

Page 119, cancel all under DEBARYA, and substitute,

DEBARYA Wittrock, 1872, p. 35.

Cells cylindrical, or contracted at the dissepiments; chro-
matophores either several, stellate, each with one pyrenoid, or
a single axial plate with several pyrenoids ; conjugation be-
tween two filaments not differing in appearance, the entire con-
tents of the conjugating cells (gametangia) passing into the
tube to form the zygospore ; gametangia not walled off from
the spore, but filling up with cellulose.

KEY TO THR SPKCIRS OP DRBARYA.
i. Spore* with longitudinal line* ami crow ridge*.

i. D. gtyptospcrm*.
i. Spores verrncote or scrobiculate, without line*. a.

THE GREEN ALGAE OF NORTH AMERICA 19

2. Vegetative cells 9-12 M diam. 2. D. americana.

2. Vegetative cells 15 M diam. or more. 3.

3. Cells 16-20 M diam., chromatophores 2, stellate. 3. D. decussata.
3. Cells 20-26 M diam., chromatophore an axial plate. 4. D. laevis.

1. D. GLYPTOSPERMA (De Bary) Wittrock, 1872, p. 35 ;
P. B.-A., No. 1419 ; Mougeotia glyptosperma De Bary, 1858,
p. 78, PI. VIII, figs. 20-25 : Wolle, 1887, p. 229, PI. CXLVI,
figs. 6-9. Filaments crisped, lubricous, 10-15 //. diam., cells
6-12 diam. long, fertile cells still longer ; spores ovoid, 42-49 X
30-40 n, with smooth, saccate, yellowish, translucent outer
membrane and yellowish-brown median membrane, with three
longitudinal parallel ridges connected by fine radial cross lines.
Fig. 9. Mass., Minn., Fla. Europe, New Zealand.

Var. FORMOSA Transeau, 1915, p. 18. Vegetative cells
7-5-9 ^ diam., spores 30-42 X 24-30 /*, steel blue. Among
Zygnema peliosporum in P. B.-A., No. 808, Cal.

2. D. AMERICANA Transeau, 1915, p. 18. Vegetative cells
9-12 X 27-120 p., constricted at the dissepiments, chromatophore
a two-lobed axial plate with two pyrenoids ; zygospores ovoid
or quadrate-ovoid, 20-40 X 30-40 /*, with angles rounded, pro-
duced or retuse ; parthenospores 15-20 X 20-30 ft, unilaterally
ellipsoid with retuse ends ; median spore wall minutely and
irregularly verrucose, yellow brown at maturity. Ontario,
A. B. Klugh.

3. D. DECUSSATA Transeau, 1915, p. 19. Vegetative cells.
16-20 X 25-50 /*, cylindrical ; chromatophores two, stellate, each
with a pyrenoid ; zygospores ovoid, quadrate-ovoid or irregular,
24-30 X 30-48, with rounded, retuse or produced angles ; aplano-
spores unilaterally ovoid, 17-25 X 20-40 p ; parthenospores
15-20 X 20-30 ft ; median membrane scrobiculate, yellow brown ;
akinetes with smooth, heavy walls, 18-20 X 20-30 ft. Pa., 111.,
Mich., Minn., Ont. Transeau.

4. D. LAEVIS (Kiitz.) W. & G. S. West, 1897, p. 476;
Zygogonium laeve Kiitzing, 1845, p. 225. Vegetative cells
20-26 p. diam., 1-5 diam. long; fertile cells often much longer;
spores broadly ellipsoid to ovoid, 42-50 ft long, 20-30 ft thick ;
median membrane thick, brown, scrobiculate. Wis., G. M.
Smith.

Page 122, and p. 75 of supplement, for Key to the Species of
Mougeotia, substitute,

i. Fructification by zygospores ; aplanosphores unknown. 2.

i. Zygospores exceptional ; usual reproduction by aplanospores. 22.

2. Spore bounded by 2 cells. 3.

2. Spore normally bounded by more than 2 cells. 15.

20 TUFTS COLLBGB STUDIES, VOL. IV, No. 7

3. Conjugation geniculate. 13. M. laeleritens.

3. Conjugation not genicnlate. 4.

4. Filaments usually genicnlate ; conjugation almost always lateral.

12. M. genuftexa,

4. Filaments not genicnlate ; conjugation scalariform. 5.

5. Spore smooth. 6.

5. Spore pitted or punctate. 13.

6. Filaments 20 M diam. or more. 7.

6. Filaments 15 M diam. or less. 9.

7. Spore projecting into the cell on each side. 8.

7. Spore occupying the tube only. n.

8. Spore about 60 M diam. 5. M. ininn f sot f nit's.

8. Spore 45 M diam. or less. 10.

9. Filaments 12-14 M diam. 7. M. delicatula.

9. Filaments 6- IOM diam. 3. M.parvula.

10. Fertile filaments straight. 4. M. sphaerocarpa.

10. Fertile filaments undulate. 6. M. divaricate.

II. Filaments about 50 M diam. 10. M. crassa.

li. Filaments 30 M diam. or less. 12.

12. Spore 55-60 M diam. u. M. macros flora.

12. Spore 30-40 ft diam. i. M. sea/art's.

13. Spore transversely ovoid. 8. M.verrucosa.

13. Spore globose or nearly so. 14.

14. Filaments 8-10, rarely 15 M diam. 2. M. nummuloides.

14. Filaments 22-32 M diani. 9. M. robusla.

•15. Spore normally bounded by 3 cells. 14. M. tenttis.

15. Spore normally bounded by 4 cells. 16.

16. Spore punctate or scrobiculate. 17.

16. Spore smooth. 18.

17. Filaments 8-12 M diam. 15. M. quadrangnlata.

17. Filaments 6-8.5 M diam. 25-

18. Filaments bluish or purplish with age. 18. flf. cap*ci*a.

18. Filaments not becoming bluish or purplish. 19.

19. Filaments 10-12 M diam. 20.

19. Filaments 8 M diam. or less. n.

20. Spore globose to angular globose, wall of uniform thickness.

19. M. calcarea.

20. Spore transversely ellipsoid, wall thicker at poles.

24. M. bicalyptrata.

21. Spore quadrangular with concave aides. 16. A/, viridts,

21. Spore quadrangular with straight sides. 17. M. (legantula.

22. A planonpores spherical. 19. M. calcarea.

22. Aplanospores elongate or snbpolygonal. 23.

23. Aplanospore* swollen on one side only. 20. M. rtniricoia.

23. Aplanospores swollen on both sides. 24

THE GREEN ALGAE OP NORTH AMERICA 21

24. Filaments 56 M diam. 21, M. Boodlei.

24. Filaments 10-13 f- diam. 22. M. Transeaui.

25. Spore with slightly tumid sides. 23. M. tumidula.

25. Spore with strongly concave sides. 25. M. gracilli ma.

Page 124, after description of MOUGEOTIA ROBUSTA, add,

Var. BIORNATA Wittrock in Wittr. & Nordst., Alg. Exsicc.,
No. 651, 1884. Mesospore yellow-brown, strongly scrobiculate ;
epispore verruculose internally ; filaments 22-30 p. diam., spores
30-36 X 42-47 p.. Charleston, 111., Transeau. Sweden, Ceylon.

After description of M. GENUFLBXA, add,

Var. GRACILIS (Kiitz.) Reinsch, 1867, p. 215 ; M. gradlis
Kiitzing, 1845, p. 221. Smaller throughout; filaments 15-24/1
diam., spores 24-30 p. diam. Charleston, 111., Transeau.

Europe.

Page 127, after description of M. CALCAREA, add,

23. M. TUMIDULA Transeau, 1914, p. 297, PI. XXVIII,
fig. 4. Vegetative cells 6-8.5 X 70-120 p, diam., zygospores
quadrate, somewhat tumid, 22-26 X 20-30 //., elliptical when
seen from the side, angles retuse, median membrane distinctly
but minutely scrobiculate. Charleston, 111., Transeau.

24. M. BICALYPTRATA Wittrock in Wittr. & Nordst., Alg.
Essicc., No. 741, 1886; De Toni, 1889, p. 722. Vegeta-
tive cells n-12 p. diam., 3-9 diam. long; conjugating cells
slightly genuflexed ; spore ellipsoid or subellipsoid, transverse,
33-38 p. max. diam., 25-28 p. min. diam. ; epispore brownish,
thickened at each pole ; mesospore brown, smooth. Carp Lake,
near Mackinaw, Mich., Transeau. Sweden.

Resembles M. calcarea, but differs by the more ellipsoid
spore, and darker epispore with calyptras.

25. M. GRACILLIMA (Hass.) Wittrock, 1872, p. 40; Tran-
seau, 1917, p. 225 ; Staurocarpus gracillimus Hassall, 1845,
p. 185, PI. VII, fig. 6; Staurospermu'm gracilli mum De Bary,
1858, p. 81, PI. VIII, fig. 12. Cells 5-7 p. diam., 8-20 diam.
long ; spores quadrate (sometimes triangular) about 25 p. wide,
sides deeply concave, angles retuse, median membrane finely
granulate. Twin Lakes, Mich., Transeau. Europe.

Page 129. Note, Printz, 1914, p. 18, considers Chlamy-
domonas communis Snow to be not the same as C. com munis,
Perty, and substitutes C. Snowii Printz. The name C. eriensis
proposed by Printz in place of C.globosa Snow, is unnecessary,
as C. globulo&a Perty does not invalidate C. giobosa Snow.

22 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

Page 130, after description of CHLAMYDOMONAS NIVALIS,
add,

6. C. MONADINA Stein. 1878, Vol. Ill, PI. XV, figs. 38-39;
Wille, 1903, p. 144. PI. IV, fig. 19. Cell subglobose, 14-26 /*
diatn., cilia 2, about as long as the cell ; 2 pulsating vacuoles
at anterior end ; stigma elongate, near anterior end ; chromato-
phore cup-shaped, posteriorly thickened, with one pyrenoid.
Greenland, P. Richter, as C. Braunii. Europe.

CRYPTOGLENA Ehrenberg, 1832, p. 150.

Cells ellipsoid to ovoid, with thin wall and 2 cilia, with several
disk-shape blue-green chromatophores ; reproduction by re-
peated division of cells that have lost their cilia.

C. AMERICANA B. M. Davis, 1894, p. 96, PI. XI. Motile
cells ellipsoid, 8-10 X 5-6 p. ; stigma single or double ; motion-
less cells 7-9 X 6-7 ft. Fig. 3. Mass., Bermuda.

Like Glocochaete and Glaucocyslis this genus has often been
placed among the Myxophyceae on account of the color, but all
other characters indicate the Chlorophyceae.

PYRAMIMONAS Schmarda, 1850, p. 9.

Cells obconical, with 4 longitudinal ribs, with no definite cell
wall ; chromatophore cup-shape, lobed, with stigma, and with
pyrenoid at base ; cilia 4, equal ; reproduction by successive
longitudinal divisions.

P. TETRARHYNCHUS Schmarda, 1850, p. 9, PI. Ill, figs. 1-8.
Fig. 4. Madison, Wis., G. M. Smith. l-'.tirope.

SPONDYLOMORUM Khrenberg, 1848, p. 236.

Colony of 16 cells, loosely attached in 4 alternating whorls of
4 cells each; cells obovoid, with membrane forming a papilla
at the smaller end of the cell ; each cell with 4 cilia at tin-
larger end, and with pyrenoid and stigma. Asexual reproduc-
tion by the formation of a i6-celled colony in each mother cell.

Only one species.

S. QUATERNARIUM Khrenberg, 1848, p. 236. Cells 5-15 \L
diam. ; colony 36-75 n diam. Fig. 5. Conn., Ohio, Cal. Eurof>c.

Page >34> aft*1* KUDORINA KLEGANS, add,

BESSBYOSPHABRA Shaw, 1916, p. 254.

Colonies spherical, containing biciliate cells in a single layer
near the surface of the colony ; vegetative and gonidial cells
intermingled, unconnected ; gonidial cells developing asexually
to form new colonies ; sexual reproduction unknown.

THE GREEN ALGAE OF NORTH AMERICA 23

Differs from Volvox in the absence of protoplasmic connec-
tion between the cells, and in that the differentiation of vegeta-
tive and gonidial cells does not occur in a colony until it is
freed from the mother colony. From Pleodorina it differs in
having vegetative and gonidial cells intermingled, not developed
in separate areas.

B. POWERSII Shaw, 1916, p. 254. Mature colony 1800-2500
It. diam., usually about 2000 /* ; vegetative cells about 12 /x diam.,
distant 50-250^; gonidia 10-78 in number ; new colonies less
than 150/11 diam. when leaving mother colony, differentiation
occurring later.*

Page 135, for generic and specific account of VOLVOX,
substitute,

Colonies spherical or ovoid, of 200-20,000 cells or even more ;
cells pyriform, in most species united by protoplasmic threads,
and closely set near the surface of the colony, the cilia pro-
jecting. A number of cells are specialized as parlhenogonidia,
asexually forming new colonies by repeated division. Sexual
reproduction by antheridia and oogonia ; the former containing
8-256 clavate antherozoids, with red stigma and two cilia ;
oospores round, with smooth or stellate membrane ; new colo-
nies formed by their germination, in the same way as by
parthenogonidia.

Powers, 1907 & 1908, gives results of the author's studies of
the genus, leading to the belief that it is impossible to include
all our American forms under the European species, V.globator
and V. aureus ; indeed he found no plants agreeing with either
of those species. Only long-continued observations in many
localities can determine whether Powers' new species will be
maintained, but the following notes indicate the diagnostic
characters as far as possible ; the author does not give as full
comparative diagnoses as might be wished ; for details the two
papers should be consulted ; the "second form " Powers, 1907,
appears now as Besseyosphaera Shaw.t

*The wording is somewhat changed from the author's description,
which is curiously zoological for a botanical subject. " Daughters less
than 150 fa diam. at birth." Figures of this species from photomicro-
graphs were given by Powers, 1907, but they are very unsatisfactory, and
as no fresh material is available, no figures are given with this paper.

tPowers' papers appeared in a publication containing little botanical
matter; indeed he refers to his species, 1908, p. 142, as part of "our
fauna ", and they have not attracted the attention they deserve, whether
their conclusions are fully accepted or not.

24 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

Page 135, for Key to the Species of Volvox, substitute,

I. Colonies ovoid ; antbeiidia arranged in spheres, without vegetntive

cells. i. /'. spermatosphata.

i. Colonies spherical. 2.

2. Colonies 600-1500/1 diam. 3.

2. Colonies 200-500 M diaui. 4.

3. Monoecious; antherozoids in free flat disks. 4. I', globular.

3. Dioecious ; antherozoids in hollow spheres, becoming flattened.

5. V. pcrglobator.
4. Colonies 350 500 M diam. ; reproductive bodies 8-10, in 2 or 3 planes.

2. V. Wcissmanniana.

\. Colonies about 200 M diam. ; reproductive bodies in varying numU T .
not originating in any definite order. 3. V. aurcus.

1. V. SPERMATOSPHARA Powers, 1908, p. 142, PI. XXIII,

XXIV; 1907, PI. XI-XIII. Colonies distinctly ovoid ; cells with
stigmas abundant at anterior pole, decreasing in number towards
posterior pole ; no strands of protoplasm connecting cells : ma-
ture colonies 1 50- looo /A diam., commonly 250-600 /*, containing
1000-3000 cells; parthenogonidia, oospores and male colonies
in varying proportions in the same colony, 1-25 in all, average
8 ; parthenogonidia ovoid, about 200 ^ diam. ; oospores 40-50 M
diam., with smooth wall ; " sperm spheres " spherical, ioo-i2Ofi
diam., containing 64,128 or 256 disks, usually 32 antherozoids
in each ; sperm spheres without distinction between poles, with
vegetative cells, breaking up while in the mother colony.
Neb., Mo.

2. V. WKISSMANNIANA Powers, 1908, p. 152, PI. XXV.
XXVI. Colonies spherical, poles differentiated; cytoplasmic
threads distinct ; mature colonies 350-500 /* diam. ; i>aithem>
gonidia, oogonia and male colonies in varying proportions in
same mother cell, usually 8, arising in two plains, sometimes
10. the two additional in another plane ; parthenogonidia 150
170/4 diam. ; oospores 40-50 n diam., with smooth wall; male
colonies spherical, 200-250 M diam., containing numerous anthe-
ridia, curved disks, of 64 or 128 antherozoids each. Mo.

3. V. AUREUS Ehrenberg, 1832, p. 77; 1838, p. 71, PI. IV,
fig. 2. Proterogynous ; colonies about 200 p. diam., of 600-900
cells with cytoplasmic connections; vegetative cells 4-6.5 /*
diam.; oogonia 1-15, 50-60 ft. diam., membrane smooth; anthe-
ridia numerous, small. 16 or 32 cells each, united in small
daughter colonies, with vegetative cells. Europe.

No American citations or localities are given for this species
or for V. globator as it is probable that much of the material

THE GREEN ALGAE OP NORTH AMERICA 25

assigned to these two species would now be assigned to one of
the newer species.

4. V. GLOBATOR Ivinnaeus, 1758, p. 320; Ehrenberg, 1838,
p. 68, PI. IV, fig. i. Colonies spherical, monoecious and
usually proterandrous, 600-800 ft diam., of 3,000-20,000 cells,
2-3 p. diam., with cytoplasmic connections; parthenogonidia
to the number of 8 in a colony, about 50 ft diam. : oogonia 20-
40 in a colony, about 50 ft diam., wall with stellate projections ;
antheridia seldom over 5 in a colony, discoid, 35-40 ft diam.,
antherozoids numerous, 5-6 ft long. Europe.

5. V. PERGLOBATOR Powers, 1908, p. 162. Colonies spher-
ical, 900-1500 ft diam., dioecious, mostly trioecious ; vegetative
cells in mature colonies more distant than in other species, but
with distinct protoplasmic connections ; oogonia stellate ;
antherozoids united in large numbers to form hollow spheres
"globoids", soon becoming flattened, poles differentiated ; re-
productive bodies of all kinds numerous in a colony, from 40 to
300. Mass., Me., Mich., Neb., La.

Powers' description of this species is less full than the descrip-
tions of the two others, and there are no plates; in material
from Fenway Park, Boston, Mass., which seems to belong to
this species, the number of reproductive bodies was less than
that given by Powers, but much more than that characteristic
of V. globator, the only species of the same habit and order of
magnitude ; the oogonia and antheridia were in distinct colo-
nies, the former about 60 ft diam. ; the latter 40-50 p. diam.;
mature colonies ranged from 800 to 1200 ft diam.

Page 138, add note,

INEFPIGIATA has proved to be a state of Botryococcus Braunii.

Page 140, add note,

Lemmermann, 1915, unites the genera PALMODICTYON and
PALMODACTYLON under the former name, with two species,
PALMODICTYON VIRIDE Kiitz. and P. VARIUM (Nag.) Lem-
mermann. The change seems justified.

Page 146, CHLOROCHYTRIUM, for "biciliate zoospores" read
" biciliate or quadriciliate zoospores." For Key to the Species
of Chlorochytrinm, substitute,

i. In fresh water phanerogams. 2.

i. In algae. 3-

2. A prolongation of the cell wall remaining where the zygote entered
the host, Lemna trisulca. C. Lemnae.

26 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

2. Cell entirely enclosed, no prolongation to surface of host. In vari-
ous plants, including species of I.fiiina, but not recorded in
L. trisulca. 2. C. R'nyanum.

3. Cell with pointed base. 3. C. Schtnitzii.

3. Base of cell not pointed. 4.

4. Cell snbhemispherical, base flattened. 4. C. dcrtnatocolax.

4. Base of cell not flattened. 5.

5. Fertile cell elongate-ovoid ; in gelatine of Rivularia colonies.

8. C. gloeoph Hum.

5. Cell globose or subglobose. 6.

6, In tnembranaceous red algae of the Pacific; cells usually 100 n

diam. or more. 5. C. inclusuw.

6.. Cell 60 M diam. or less. 7.

7. Cell 40-60 n diam., entirely included in fronds of Porphyra.

7. C. Porphyrae.

7. Cell 30 M diam. or less, partly external, or when immersed having a
tube-like projection connecting with the surface. 6. C. Moorei.

Page 148, cancel generic description of CHLOROCYSTIS, and
for C. COHNII (Wright) Reinhardt substitute CHLOROCHY-
TRIUM MOOREI Gardner, 1917, p. 382 ; Chlorocystis Cohnii
Moore, 1900, p. 100 ; not C. Cohnii Reinhardt, 1885, p. 4, which
is Chlorochytrium Rcinhardtii Gardner, 1917, p. 382 ; nor Chlo-
rochytrium Cohnii Wright, 1879, p. 355 ; place as No. 6 under
CHLOROCHYTRIUM.

7. C. PORPHYRAE Setchell & Gardner in Gardner, 1917, p.
379, PI. XXXII, fig. 6. Cells spherical, 40-60 ft diam., im-
bedded in the membrane of Porphyra perforata forma segrtgata
Setchell & Hus. on both sides of the median layer of ft-lls ;
chromatophore single, at first small, covering the upper part of
the cell, increasing by sending out several arms, finally cover-
ing the wall ; pyrenoid single, large ; cell wall 2-3 n thick, not
laminate; color grass-green: sexual reproduction by biciliate
gametes, 3-4 /* diam., fusiform to subspherical, escaping by an
oval opening in the wall ; asexual reproduction unknown.
Lands End, San Francisco, Cal., Gardner.

8. C. GLOEOPHILUM Bohlin, 1897, p. 28, PI. I, figs. 53-54;
G. F. Moore, 1917, p. 271, PI. XVIII. Vegetative cells sub-
spherical, 25-30 n diam., with single parietal chromatophore,
usually covering the entire cell wall, with one large pyrenoid ;
later developing into an ovoid-oblong sporangium, 50-70 X 25-
35 M occasionally even larger; wall 5-10 /* thick, often with
irregular prominences, external or internal, which sometimes
show lamination; 32-64 spherical aplanospores, 4 /* diam.,

THE GREEN ALGAE OF NORTH AMERICA 27

formed by successive division, released by disintegration of the
mother cell wall. In colonies of Rivularia Bornetiana, Mass.,
Conn. So. America.

Moore observed the formation of a pore in the cell wall, simi-
lar to that used for the exit of zoospores in the other species of
the genus, but no zoospores were seen in this species, nor any
tendency of the aplanospores to make use of the pore. He
suggests that zoospores, unavailable in the dense gelatine of
the host, have ceased to be produced, the pore remaining as
the only evidence of their former existence.

DICRANOCHAETE Hieronymus, 1887, p. 293.

Cell reniform, attached, with a single chromatophore with or
without pyrenoids ; with slender, dichotomously branched bris-
tles. Reproduction by 8-24 zoospores each with stigma, con-
tractile vacuole and 2 cilia.

D. RENIFORMIS Hieronymus, 1887, p. 293 ; G. S. West, 1916,
p. 212, fig. 139. Cells seen vertically reniform, laterally sub-
hemispherical, up to 32 /A wide ; bristle arising from the base
and passing up by a lateral groove in the cell wall, 80- 1 60 p long.
Attached to submerged plants etc. Fig. 6. Maine, F. D. Lam-
bert. Europe.

GLOEOCHAETE Lagerheim, 1883, p. 39.

Cells globose or subglobose, 1-4 in a wide mucilaginous coat-
ing, each with i or more long, slender, tapering setae ; chroma-
tophore bell-shape, blue-green ; reproduction by vegetative
division.

G. WITTROCKIANA Lagerheim, 1883, p. 39; G. S. West,
1904, p. 344, fig. 160. Cells 6-21 p. diam., setae 100-260 //. long,
one or more to a cell. Fig. 7. Harpswell, Maine, F. D. Lam-
bert, Wis., G. M. Smith. Europe.

In spite of the color, the affinities of this plant seem to be
with the Chlorophyceae.

Page 149, for Key to the Species of Characium, substitute,

i. Growing on animals. 2.

I. Not on animals. 3.

2. Ovoid or broadly ellipsoid. 8. C. DeBaryanum.

2. Elongate. n.

3. Sessile. i. C. sessile.

3. With a longer or shorter stipe. 4.

4. Apex acute. 5.

4. Apex rounded. 7.

28 TUFTS COLLEGE STUDIKS, VOL. IV, No. 7

5. Without basal enlargement of stipe. 7. C. ambiguum.

5. With basal enlargement of stipe. 6.

6. Basal enlargement capitate. 9. C. acumitiatutn.

6. Basal enlargement a disk. 12.

7. Without basal enlargement of stipe. 8.

7. With basal enlargement of stipe. 10.

8. Stipe long. 9.

8. Stipe short and stout. 2. C. Sieboldii.

9. Cell pyriform, up to 8 M long, stipe 10-16 M. 13. C. stipitatum.

9. Cells up to 20 M long, stipe 8 /*. 5. C. heteromorphum.

10. Broadly ellipsoid. 6. C. obtusutn.

10. Narrowly lanceolate to linear. 4. C. strict tun.

II. Regularly elongate-fusiform. 14. C. liintiftuutn.

ii. Cylindrical with tapering ends. 12. C. gradlipes.

12. Cell erect or somewhat oblique ; stipe shot t.

n. C. Pringskfimii.

12. Cell more or less distinctly falcate ; stipe longer.

15. C. rostratum.

Page 150, Note C. Natgelii and C. cylindricum have been
transferred to Characiopsis, p. 4.

C. DEBAR YANUM should not read (Reinsch) nov. comb., but
C. DEBARYANUM (Reinsch) De Toni, 1889, p. 628.

Page 151, after description of C. GRACIUPBS, add,

13. C. STIPITATUM (Bachmann) Wille, 1909, p. 45 ; Brunn-
thaler in Pascher, 1915, p. 81, fig. 26; G. M. Smith, 1916,
p. 472, PI. XXIV, figs. 4-6; Chlamydomonas stipitata Bach-
niann, 1908, p. 81, figs. 1-15. Cells globose to ovoid, .5-8 /*
diam., with very slender stipe, 10-16 ft long. In the gelatinous
coating of Coclosphaerium. Wis., G. M. Smith. /-.w/vyV.

14. C. UMNHTICUM Lemmermann, 1903, p. 81, PI. Ill
figs. 7-10. On the crustacean Diaphanosotna. Cells 25-80 X
5-14 M, fusiform, mostly curved, rarely straight, prolonged into a
stipe 6-10 M long, without basal disk. Apex ending in a long,
bristle-shaped beak ; chromatophores 4-8, band-shape, parietal,
with i pyrenoid; Wis., G. M. Smith. Sweden.

15. CHARACIUM ROSTRATUM Reinhard fide Printz, 1913,
p. 41, PI. II, fig. 32 ; 19153, p. 17, PI. I, figs. 36-39. Cell from
lanceolate with curved apex to strongly falcate ; length without
stipe, 23-28 M. width 5-7 p. ; stipe 5-9 ft long, with distinct basal
disk. Twin Lakes, Mich., Transeau. Europe, Asia.

The orginal publication by Reinhard being inaccessible, the
determination is from Printz.

Brunthaler in Pascher, 1915, p. 83, resuscitates C. subsessile

THE GREEN ALGAE OF NORTH AMERICA 29

(Wolle) De Toni, 1889, p. 622 ; Hydrianum subsessile Wolle,
18773 p. 186 ; and C. giganteum (Wolle) De Toni, 1889, p. 624 ;
Hydrianum giganteum Wolle, 18773, p. 186, but descriptions
are too unsatisfactory for recognition.

Page 157, for Key to the Species of Rhaphidium, substitute,

KEY TO THE SPECIES OF ANKISTRODESMUS.

i. Cells or colonies in gelatinous sheath. 5. A. lacustris.

i. No gelatinous sheath. 2.

2. Cells fusiform, ending in long bristles. 4. A. setigerus.

2. No bristles. 3.

3. Cells much twisted. 2. A. convolutus.

3. Cells straight or curved, not twisted. 4.

4. Cells slender, fusiform to acicular, straight, sigmoid or somewhat

lunate, gradually tapering to a fine point. i. A.falcatus.

4. Cells stouter. 5.

5. Cells subcylindrical, usually straight, short-pointed.

3. A. Braunii.

5. Cells more or less lunate with acute apices; chromatophore with
central notch and 2 pyrenoids. 6. A. Chodati.

Page 158, after description of R. SETIGERUM, note,

G. M. Smith, 1916, p. 473, PI. XXIV, fig. 8, removes this
species to the genus Schroederia as 6". setigera (Schroder) Lem-
mermann, 1898, p. 311, and describes a new species, S.Judayi
G. M. Smith, 1916, p. 474, PI. XXIV, figs. 9-11. Cells fusi-
form, straight or curved, ends attenuate into hair-like projec-
tions, one of which terminates in a disk ; chromatophore single,
parietal, with one pyrenoid. Length with spines, 45-63 n,
without spines, 14-30 /* ; breadth 6-25 /*. Wis., G. M. Smith.

The genus SCHROEDERIA was separated from ANKISTRODES-
MUS by Lemmermann on account of the much prolonged apices,
but has not generally been accepted. G. M. Smith figures a
terminal disk in >S. setigera, as well as in S. Judayi. If this is
really a generic character, it may raise some questions as to the
affinities of the genus.

5. A. LACUSTRIS (Chodat) Ostenfeld, 1907, p. 384 ; Raphi-
dium Braunii var. lacustris Chodat, 1902, p. 200, fig. 117. Cells
scattered without order in the gelatinous sheath, fusiform,
18-37 X 4 p, straight or somewhat curved, ends usually acute.
Wis., G. M. Smith. Europe.

6. A. CHODATI (Tanner) Brunnthaler in Pascher, 1915,
P- r93> fig- 3°6 5 Raphidium Chodati Tanner-Fullemann, 1906,

30 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

p. 158, fig. ii. Cells arcuate, acuminate, 30-80^1 long, 5-7 M
wide, chrotnatophore notched at the middle, with two pyrenoids.
Wis., G. M. Smith. Europe.

The description belongs to the European plant ; the Amer-
ican plant, while agreeing as to dimensions, notched chromato-
phore and pyrenoids, is usually straight or slightly curved.

CLOSTERIOPSIS Lemmermann, iSgSc, p. 29.

Cells mostly solitary, very long in proportion to the diameter,
with many pyrenoids in a single series ; otherwise as in
A nkistrodesm us.

C. LONGISSIMA (Schroder) Lemmermann, var. TROPICA W. &
G. S. West, 1904, p. 31, PI. I, fig. i. Cells mostly solitary,
225-370 X 6-7.5 /i, slightly curved, tapering gradually to the
slender but subtruncate ends. Fig. 8. Wis., G. M. Smith.

Europe.

The typical form of C. longissimat not yet reported here, has
tips tapering to an extreme fineness, and is usually more curved.

QUADRIGULA Printz, 1915, p. 49.

Cells cylindric-fusiform, straight or slightly curved, apices
more or less acuminate, without pyrenoid ; vegetative reproduc-
tion by division of cell in two planes at right angles to each
other at the longitudinal axis of the cell, the four daughter
cells remaining enclosed in a gelatinous mass, which as a result
of successive divisions may contain as many as 128 cells. Only
one species.

Q. CLOSTERIOIDKS (Bohlin) Printz, 1915, p. 49, PI. IV, figs.
110-116; Nfphrocytium dosterioides Bohlin. 1897, P- 18, PI. I,
figs. 23-24; Raphidium I*fit*eri Schroder, 1902, p. 152, PI. VI,
fig. 6 ; Ankistrodcsmus Pfitzeti G. S. West, 1904, p. 224, fig.
94. G. Cells 12-30 X i. 5-3.7 M- Fig- 9- Wis., G. M. Smith :
New Buffalo, Mich., Transeau. Europe.

The cells are in shape much like those of Ankistrodcsmus. but
in the latter the cell division is by an oblique wall. In .-/. lartts-
tris, in which the daughter cells remain enclosed in a gelantinous
body of definite form, they are in no definite order, while in
Quadrigula the four daughter cells merely separate but remain
parallel. In a subsequent division all cells in the colony par-
ticipate, so that however large the number of cells, they continue
symmetrically placed.

THE GREEN ALGAE OP NORTH AMERICA 31

Page 159, for Key to the Species of Oocystis, substitute,

i. Outer wall of the family thickened at the poles. 2.

i. Outer wall not thickened at poles. 4.

2. Individual cells thickened at poles. 3.

2. Individual cells not thickened at poles. 7. O.parva.

3. Many chrotnatophores. 3. O. solitaria,

3. 1-2 chromatophores. 2. O. lacustris.

4. Families often united in colonies by successive persistent walls. 10.

4. Families not united in colonies. 5.

5. Cells with thickening at poles. 6.

5. Cells not thickened at poles. 8.

6 Cells with polar thickening projecting internally. 8. O.nodulosa.

6. Cells without internal projection. 7.

7. Cells with concave sides and pointed ends. 9. O. panduriformis.
7. Cells with convex sides. 4. O. crassa.

8. Cells elongate-ellipsoid, about 2.5 diam. long. n.

8. Cells proportionally broader, ends more broadly rounded. 9.

9. Cells 9-17 fj. long. i. O. Borgei.

9. Cells 33-40 M long. 6. O. Naegelii.

10. Poles rounded. 5. O. novae-semliae.

. 10. Poles acute. n. O. gloeocystiformis.

ii. Chromatophores 1-2, with pyrenoid ; cells mostly solitary.

12. O. rupestris.

ii. Chromatophores 10-20, without pyrenoid : cells usually in families.

10. O. elliptica.

Page 79 of Supplement, after description of O. NOVAE-
SEMLIAE, add, Var. MAXIMA W. & G. S. West, 1894, p. 13,
PI. II, fig. 25. Cells 2-3 times larger than in the typical form,
19-23 X 12-15/1; family of 2-4 cells, 40-52 X 23-42/1. Wis.,
G. M. Smith. Europe.

7. O. PARVA W. & G. S. West. 1898, p. 335; 1900, PI.
CCCXCIV, figs. 14-17. Cells mostly solitary, but sometimes
in families of 2-4 cells; ellipsoid, 6-12 X 4-7 /*, ends slightly
pointed, not thickened, wall firm ; chromatophores 2-3. Wis.,
G. M. Smith. Europe.

8. O. NODULOSA W. & G. S. West, 1894, p. 15, PI. II, fig.
31. Cells oblong-ellipsoid, end rounded with papillate thicken-
ing, projecting internally ; cells 25-30 X 16-18 ft, solitary or two
in the much broadened mother cell wall. Wis., G. M. Smith.

Europe.

9. O. PANDURIFORMIS var. MINOR G. M. Smith, 1916, p.
471, PI. XXIV, fig. 2. Cells ovoid with somewhat concave

32 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

sides and pointed ends, with 15-25 disk-shape chromatophores
with distinct pyrenoids ; cells 30-35 /* long, median diani.
11-14 ft, max. diam. 12-15/1- Wis., G. M. Smith.

The typical form, W. & G. S. West, 1894, p. 15, PI. II, figs.
33-35, of about double these dimensions, has not been reported
in this country.

10. O. ELLIPTICA W. West, 1892, p. 736; Printz, 1913,
p. 182, PI. IV, fig. 33. Cells elongate-ellipsoid, with ends
rounded, not thickened, 22-25 X 11-12 /*, rarely solitary, mostly
in 4-8 celled families ; chromatophores 10-20, without pyrenoid.
Mich., Transeau. Europe.

Var. MINOR, W. & G. S. West, 1894, p. 14, PI. II, fig. 26,
Cells 15-22 X 7-10/1. Wis.. G. M. Smith. Europe.

11. O. GLOEOCYSTIFORMIS BorgC, 1906, p. 23, PI. II, fig. I.

Cells ellipsoid, with a thickening and a short, acute prolonga-
tion at each pole, 9 X 4-5 /*, 2 to several in a family, families
several in a general gelatinous coating, showing more or less
distinctly successive mother-cell walls. Wis., G. M. Smith.

• / del Fuego.

12. O. RUPESTRIS Kirchner, 1880, p. 169, PI. II, fig. 2;
Print/., 1913, p. 174, PI. IV, figs. 7-9 ; Wittr. & Nordst., Alg.
Kxsicc., Nos. 725, 1248. Cells oblong-ellipsoid, 13-28 X 6-12 ft,
poles rounded, not thickened ; chromatophores 1-2, with pyre-
noid ; mother cell wall soon dissolving, hence cells usually
solitary. Wis., G. M. Smith. Northern Europe.

GLAUCOCYSTIS Itzigsohn in Rabenhorst, 1868, p. 417.

Cells ellipsoid or ovoid, solitary or 2-8 in a family enclosed
by the mother cell wall ; chromatophores blue-green, in younger
cells many and scattered, later filiform and radiating stellately
from a central vacuole ; asexual reproduction by autospores,
usually 4 in a cell.

G. NOSTOCHINRARUM Itzigsohn in Rabenhorst, 1868, p. 417 ;
G. S. West, 1916. p. 40, fig. 24. Cells ellipsoid. 18-28 X
10-18 /*, membrane thin. Fig. 10. Scattered among other algae
in quiet water. Mass. I', it rope.

This genus has often been placed among the Myxophyceae,
on account of its color, but its other characters seem to place it
better in the Chlorophyceae, near Oo,

Page 1 60, cancel everything relating to CHODATKLLA, and

substitute,

THE GREEN ALGAE OP NORTH AMERICA 33

LAGERHEIMIA Chodat, iSgsb, p. 86.

Cells ovoid or ellipsoid, the membrane bearing 2 or more
setae, the base with or without thickening ; chromatophores
one or many, parietal, with or without pyrenoid ; cells free
or cpntained in the mother cell wall. Reproduction as in
Oocystis, from which it differs only by the presence of setae.
Chodatella L,emmermann is included, its only difference from
Lagerheimia being the absence of thickening at the base of
the setae.

KEY TO THE SPECIES OF LAGERHEIMIA.

i. Setae from all parts of the cell. 2. L. Droescheri.

i. Setae from ends only. 2.

2. Cells with an obtuse projection at each end. i. L. citriformis.

2. Cells without obtuse projection. 3.

3. Setae 44-55 M long. 5. L. longiseta.

3. Setae 7-26 M long. 4.

4. Cells 12-21 X 9-15 M; 3-7 setae at each end. 3. L. ciliata.

4. Cells 5-13 X 2.5-8.5 M; 2-3 setae at each end. 4. L. subsala.

1. Iy. citriformis (Snow) nov. comb. ; Chodatella citrijormis
Snow, 1903, p. 381, PI. II, fig. VIII. Cell ellipsoidal with an
obtuse projection at each end, 13-23 X 8-20 /n; chromatophore
single, with pyrenoid ; setae slender, in whorls about the pro-
jections at the ends of the cells. Collins, 1909, Fig. 45. Lake
Erie.

2. L. DROESCHERI (Lemm.) Printz, 1914, p. 60; Chodatella
Droescheri Lemmermann, 1900, p. 98, PI. Ill, fig. 12. Cells
10-16 X 5-12 /A, beset with numerous tapering setae, 10-17 /*
long. Wis., G. M. Smith. Europe.

2. L,. CILIATA (L,agerh.) Chodat, iBg^b, p. 86; Oocyslis
ciliata Lagerheim, 1882, p. 76, PI. Ill, figs. 33-37. Cells
12-21 X 9-18 ft, solitary or 2-8 in a family; setae 3-7 at each
end, 18-20 i*. long. Wis., G. M. Smith. Europe.

Var. minor (G. M. Smith) nov. comb. ; Chodatella ciliata
var. minor G. M. Smith, 1916, p. 477, PI. XXV, fig. 16.
Cells 8-10 X 6-7.5 /A, with 6-8 setae at each end. Wis., G. M.
Smith.

Differs from the typical form by the smaller size, and usually
more abundant setae.

4. L,. SUBSALSA Ivemmermann, i898b, p. 193, PI. V, figs.
2-6. Cells 5-13 X 2.5-8.5 //., solitary or 2-8 in a family ; setae

34 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

not formed until after leaving the mother cell, 2-3 just below
each end, 7-26 /* long. Wis., G. M. Smith. Europe.

5. L. LONGISETA (Lemm.) Printz, 1914, p. 60; Chodatclla
sub salsa var. longiseta Lemmermann, 1898, p. 310, PI. X, figs.
11-18. Cells ellipsoid, in vertical view circular, 8 /n wide, 12 /*
long, each end with 4-10 setae, 44-55 /* long. White Sand
Lake, Wis., G. M. Smith. Europe.

MICRACTINIUM Fresenius, 1858, p. 236.

Cells spherical or nearly so, solitary or loosely united in
colonies, cell with gelatinous envelope, bearing long, hyaline
setae, chromatophore bell-shaped, parietal, with or without
pyrenoid ; asexual reproduction by division in 2-3 directions,
the autospores escaping by an opening in the wall ; also by
akinetes.

KEY TO THE SPECIES OF MICRACTINIUM.

I. Cells mostly solitary ; setae uniformly distributed, cylindrical. 2.
i. Cells mostly in colonies; setae unilaterally placed, with thickened

base. 3.

2. Setae numerous, 25-45 j* long. i. M. radiatum.

2. Setae few, about 16 M long. 2. M. f>ancisf>inosutn.

3. Cells 3-7 M diatn., with 1-3 setae, about 60 n long. 3. M. f>usillu»i.

3. Cells 6.5-10 M 'liam., with 4 setae, 23-40 /* long. 4. M. quadrisftuin.

1. M. RADIATUM (Chodat) Wille, 1909, p. 57; Golcnkinia
radiata Chodat, 18943, p. 305, PI. III. Cells spherical, solitary
or in 4-celled colonies, 10-15 /* diam., with numi-rous setae,
25-45 M long, Fig. ii. Wis. G. M. Smith. l-.urope.

2. M. PAUCISPINOSA (W. & G. S. West) G. S. West, 1916,
p. 198, fig. 124, F; Golenkinia paucispinosa W. & G. S. West,
1902, p. 68, PI. I, fig. 18. Cells solitary, spherical, 15-16/1
diam., with a few setae, about 16 p. long. Wis., G. M. Smith.

I>< land.

3. M. PUSILLUM Fresenius, 1858, p. 236, PI. XI, figs. 46-49 ;
G. M. Smith, 1916, p. 477, PI. XXV, fig. 18; Richteriella botry-
oidcs Lemmermann, 1898, p. 306, PI. X, figs. 1-6. Cells spher-
ical, 3-7 n diam., forming colonies of four cells in one plane,
each with 1-3 tapering setae, about 60 /t long. Wis., G. M.
Smith. t-.urope.

4. M. QUADRISETUM (Lemm.) G. M. Smith, 1916, p. 479,
PI. XXV, fig. 17; Richteriella quadriseta Lemmermann. 1898,
p. 307, PI. X, fig. 7. Cells somewhat ellipsoid or ovoid, 6.5-7 X
7-10/1, each with 4 setae, 23-40 /i long. Wis., G. M. Smith.

Europe.

THE GREEN ALGAE OF NORTH AMERICA 35

FRANCEIA L,emmermann, 1898, p. 307.

Cells single or united in colonies, enclosed in a gelatinous,
hyaline envelope ; cell with 2-3 parietal chromatophores, and
with long spines, base of spine not thickened ; asexual repro-
duction by division of cells in one plane.

F. OVALIS (France) Lemmermann, 1898, p. 308, Phythelios
ovalis France, 1894, p. 2, figs. 1-5; Golenkinia Franzei Chodat,
18943, p. 308. Cells ovoid or ellipsoid, 10 /* wide, 17 /u. long,
with many spines, about 23 /x long. Fig. 12. Wis., G. M. Smith.

Europe.

The dimensions given above are those of the European plant ;
Smith's specimens from Wisconsin are decidedly smaller,
7 X 13 /*, with spines 15 p. long.

ACANTHOSPHAERA L,emmermann, 18993, p. 118.

Cells spherical, solitary (chromatophore single?) with distinct
pyrenoid ; membrane very thin, with gelatinous coating and
many spines ; spines with lower part rather thick and refring-
ent, above very slender and hyaline. Only one species.

A. ZACHARAISII L,emmermann, 18993, p. 118, PI. I, figs.
10-11. Cells 10-14 /A diam., spines 30-35^ long. The princi-
pal character of this species is found in the spines, the lower
third relatively stout and distinct ; the upper two-thirds delicate
and hyaline, visible only when dried, or under high magnifica-
tion. Fig. 13. Wis., G. M. Smith. Europe.

Page 161, for Key to the Species of Nephrocytium, substitute,

i. Cells semicular with rounded ends. 3. N. obesum.

i. Cells reniform. 2.

2. Daughter cells 2-7 /x diam., 3-6 diam. long. i. N. Agardhianum.

2. Daughter cells 11-22 n diam., 2 diam. long. 2. N. Naegelii.

and after description of N. NAEGELII, add,

3. N. OBESUM W. &G. S. West, 1894, p. 13, PI. II, figs. 39-
40. Daughter cells nearly semi-circular with rounded ends, the
ventral edge straight or slightly concave, 15-28 p wide, rarely
more, 25-49 /A long. Two cells within the mother cell wall,
which may be over 100 /* long and wide, with very thick mem-
brane. Manistique, Mich., Transeau. England, So. America.

Page 161, for Key to the Species of Tetraedron, substitute,
i. Cells without spines or sharp tips to lobes. 2.

i. Cells with spines or sharp tips to lobes. 8.

2. Cells with 3 rounded angles. 3.

2. Cells with more than 3 angles. 4.

36 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

3. Sides straight to snbconvez, membrane reticulate.

6. T. reticulalutn.
3. Sides straight to sinuate, membrane smooth or finely punctate.

2. T. mti tic it i n.

4. Cells with 4 angles. 5.

4. Cells with 5 angles or more. 7.

5. Cells 18-30 Mdiam. ; membrane granular-punctate. 5. T.punctatum.
5. Membrane smooth. 6.

6. Cells 6-1 1 M diam., sides distinctly emarginate. 4. T. minimum.

6. Cells 15-21 M diam., sides not emarginate. 3. T. tetragonum.
7. Irregularly 5-6-angled, 35.75 M diam., menbrane thin. 13. T.gigas.
7. Rather regularly 6-8-angled, 17-26 M diam., membrane laminate.

ii. T. pachyderm u in .

8. Cells semicircular to ovate with sides of unequal curvature, a spine
at each end. 18. T- obesum.

8. Cells not as above. 9.

9. Each angle with one spine. 10.

9. Bach angle with 2 or more spines. 17.

10. Spines short. 11.

10. Spines longer. 16.

u. Cells asymmetrical or contorted. 29.

n. Sides and surfaces of cells symmetrical or nearly so. 12.

12. Cells flattened, triangular. i. T. trigonum.

12. Cells more than 3-angled. 13.

13. Cells 4-angled. 14.

13. Cells 5-angled. 15.

14. Cells flattened, quadrate. 7. T. quadratuin.

14. Cells tetraedral. 12. T. regular e.

15. Cells flattened. 9*. T. caudatum.

15. Cells pen taedrical. 20. T. pentaedricutn.

16. Cells irregularly triangular, twisted, 73-81 M diam., spines about
30 M long. 19. T.tortittn.

16. Cells either fusiform, 65 X 12 M, or stellate with 3 rays, body about
36 M diam., margins sinuous, angles passing gradually into
spines. 27. 7\ proteifornif.

17. 4- 10 slender spines, 30-40 M long, at each angle. 21. '/'. */>/«// A u/<;«.
17. Spines relatively shorter and stouter. 18.

18. Cells with arm-like prolongations. 19.

18. Cells without arm-like prolongations. 23.

19 Arms not divided, except at tip. 20.

19. Arms 1-5 times divided. 21.

20. Cells tetraedral. 22.

20. Cells flatter. 28.

21. Ultimate division* very slender, acute. 8. T. gracile.

it. Ultimate divisions broader, especially in top view. 30.

THE GREEN ALGAE OK NORTH AMERICA 37

22. Body of cell inconspicuous, rays twice bifid, total diam. up to

7° V~ 22. T. limneticuin.

22. Body more conspicuous, rays once bifid or trifid ; total diam. not

over 33 /*. 28. T. hastatum.

23. Cells irregularly octaedral. • 25. T.floridense.

23. Cells 3- or more-angled. 24.

24. Cells flattened. 27.

24. Cells not flattened. 25.

25. Cells with rounded sides and inconspicuous angles.

14. T. arinatum.

25. Cells irregularly tetraedric, with conspicuous angles. 26.

26. Angles and spines repeatedly forked. 16. T. enortne.

26. Angles short, with concave ends and 2 short spines.

15. T. b if urea turn.

27. Cells quadrangular. 26. T. lobiilatuni var. polyfiircatum.

27. Cells polygonal. 10. T, angulosum.

28. Cells cruciate. 23. T. pusillum.

28. Cells with 2 long, subparallel, and 2 deeply emarginate sides.

29. T. artkrodesmiforme var. lobnlalum.
29. Cells much twisted, with deep median division into semicells.

30. T. victoriae.
29. Cells without deep division, with 3 or 4 unequal sides.

9. T. quadricuspidalum.
30. Width between apices 30-40 /x; cells flat or pyramidal.

26. T. lobulatum.
30. Width between apices 50-70 M ; cells flat. 24. T. planctonicum.

Page 162, after TETRAEDRON TRIGONUM var. PUNCTATUM,
add,

Var. SETIGERUM (Archer) I/emmermann, 1904, p. no; Tetra-
pedia setigera Archer, 1872, p. 365, PI. XXI, figs. 14-17 ; G. S.
West, 1904, p. 349 ; Polyedrium trigonum var. setigerum
Schroder, 1898, p. 23, PI. I, fig. 6. Cells with strongly con-
cave sides, the rounded angles each with a long straight spine.
Wis., G. M. Smith. Europe.

Described by Archer and accepted by West and Forti as be-
longing to the Myxophyceae, the species seems to belong
better to the Chlorophyceae, as surmised by Schroder and
Lemmermann ; as noted by G. M. Smith the chromatophore is
grass-green and contains a single central pyrenoid. Shape
and dimensions agree exactly with Archer's description, so that
there is little doubt of the identity.

Page 165, after T. REGULARS var. LONGISPINUM, add,

Var. INCUS Teiling, 1912, p. 277, fig. 12. Cells tetraedral,

56097

38 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

less commonly flat with concave sides; short sides 14-16 ft,
longer sides i6-i8fi, isthmus of former 13-14 /x, of latter 7-9 /x
wide; spines 7-8 /* long, usually slightly curved. Wis.. G. M.
Smith. liuropf.

Var. TORSUM (W. B. Turner) Brunnthaler in Pascher, 1915,

p. 150, fig. 169 ; Polycdrium tctracdricum var. torsum W. B.

Turner, 1892, p. 158, PI. XX, fig. 15. Angles prolonged and
twisted. Wis., G. M. Smith. Asia.

Page 80 of supplement, after T. CAUDATUM, add,

Var. LONGISPINUM Lemmermann, 1898, p. 151 ; 18993, p. 1 17,
PI. I, figs. 8-9. Cells 10-12 /t diam., spines 8-10 /* long, each
bent at a right angle with the plane of the cell body. Wis.,
G. M. Smith. Europe.

Page 166, after description of T. ENORME, add,

1 8. T. OBESUM (W. & G. S. West) Brunnthaler in Pascher,
1915, p. 154 ; Reinschiella obcsa W. & G. S. West. 19018, p. ioo,
PI. IV, figs. 53-54. Cells serai-circular to ovate with one side
more convex than the other, about 30 X 14 M. each end with a
strong spine about 7 p. long, curved towards the convex side ;
cells often in pairs. Me., F. D. Lambert. Siam.

19. T. TORTUMW.&G.S. West, i895b, p. 52. Cell irregularly
triangular, twisted, sides convex or concave or nearly straight ;
angles slightly prominent, each ending in a sharp spine about
30 fi long. Membrane thick. Cell without spines, 73-81 /A
diam., 42-44 /* thick. " North America " West.

20. T. PENTAEDRICUM W. & G. S. West, 18958, p. 84, PI.

V, figs. 15-16. Cells pentagonal, sides concave, angles rounded,
each with a curved or hooked spine. Cells 10-15 /* diam.,
without spine ; spine 4.5-5.5 M long. Wis., G- M. Smith.

Madagascar.

21. T. SPINULOSUM Schmidle, 1896, p. 193; Brunnthaler in
Pascher, 1915, p. 154, fig. 188 ; Polyedriopsis spinulosa Schmidle
in Lemmermann, 18993, p. 118. Cells 4-5-angled, up to 20 M
diam., angles somewhat prolonged, each bearing 4-10 irregularly
placed, slender, somewhat tapering spines, 30-40 n long. Wis.,
G. M. Smith. Europe.

The habit, small body with many very long slender spines, is
quite different from the other species of the genus, and perhaps
most writers would accept Schmidle's second thought, and
make a separate genus for it. But when one begins to divide
up Tttraedron, it is hard to stop, and for the present Polyedriop-

THE GREEN ALGAE OF NORTH AMERICA 39

sis may be kept as a subgenus, following Wille, with this one
species.

22. T. LIMNETICUM Borge, 1900, p. 5, PI. I, fig. 2. Cell
tetraedral, angles extending into long arms, each with 2 short
spines at tip; cells 65-70 /* diam., arms about 8-10 ft diam.
Wis., G. M. Smith. Europe.

23. T. PUSILLUM (Wallich) G. S. West, 18973, p. 237 ;
Micrasterias pusilla Wallich, 1860. p. 281, PI. XIII, fig. 13.
Cells flattened, cruciate, arms each with 2 crooked spines at
end; cells 25 ft wide, 10 ft thick. Wis., G. M. Smith. India.

24. T. PLANCTONICUM G. M. Smith, 1916, p. 479, PI.
XXVI, figs. 19-20. Cells 4-5-sided, sides generally incurved
and equal ; angles of cells prolonged into bifurcate or trifurcate
processes ending in 2 or 3 horns; processes broad in top view,
narrow in side ; cells without processes 18-24 P diam., with
processes 50-70 ft diagonal diam., diam. of processes 9-12 X
5-8 /», length 15-25 p.. Wis., G. M. Smith.

25. T. FLORIDENSE W. & G. S. West, 1898, p. 7. Cells
irregularly octaedral, sides slightly convex, angles forked, with
a somewhat curved spine on each fork ; cells 34-44 ft without
spines, with spines 44-59 /*. Deland, Fla.

26. T. LOBULATUM (Nag.) Hansgirg, 1888, p. 132; Polye-
drium lobulatum Nageli, 1849, p. 84, PI. IV, B, fig. 3 ; Reinsch,
1867, p. 78, PI. II, fig. II. Cells irregularly and indistinctly
tetraedral, sometimes flattened, margins from straight to deeply
concave ; angles usually 2-parted, each part with 2, rarely 3
points, very rarely the angle only emarginate ; width 30-74 ft.
Wis., G. M. Smith. Europe.

Var. POLYFURCATUM G. M. Smith, 1916, p. 480, PI. XXVI,
figs. 21-22. Prolongations branching 3-5 times, ultimate divi-
sions with 3 spines ; prolongations nearly as long as body of
cell; diam. 10-20 ft without processes, 30-40 ft with processes;
diagonal diam. 35-50 fi. Wis., G. M. Smith.

This variety seems transitional between the forms with
spinous angles and those with distinctly arm-like prolongations.

27. T. PROTEIFORME (Turn.) Brunnthaler in Pascher, 1915,
p. 152, fig. 177. Polyedrium proteiforme W. B. Turner, 1892,
p. 158, PI. XX, fig. 24b. Cells fusiform or triangular, with
sinuate sides and prolonged angles, each passing into a spine,
not sharply distinct from the cell disk ; fusiform individuals
about 65 ft long, 12 ft wide ; triangular 36 fi diam. with spines.
Wis., G. M. Smith. India.

40 TUFTS COI.I.KC.I: STI-UIKS, VOL. IV, No. 7

A cut, however rude, gives a better idea of this species, than
a description, however full ; this is true more or less of all
species of the genus. To do any work in it one should have
either a library with everything published on fresh water algae,
or Pascher's handbook, with its cuts.

28. T. HASTATUM (Rcinsch) Hansgirg, 1888, p. 132; Poly-
tdrinm tctracdricum var. hastatiun Reinsch, 1867, p. 77, H V,
fig. III. Cells tetraedral, about 23 /* wide, with 4 lateral sub-
concave surfaces ; angles gradually narrowed, each with a single
spine, shortly tridentate. Wis., G. M. Smith. /Europe.

Var. PALATINUM (Schmidle) Lemmermann, 1904, p. 112;
r^lytdriutn hastatum var. palalinum Schmidle, 1900, p. 148,
PI. VI, figs. 4-5. Cells rounded, mostly telraedal, less com-
monly disciform, each angle drawn out into a long prolongation,
bifurcate at the tip. Wis., G. M. Smith. Europe.

29. T. ARTHRODESMIFORMK var. LOBULATUM Wolos/ynska.

1914, p. 203, PI. VI, fig. ii. Cells with two long straightish
sides, each with a long, somewhat spreading prolongation, end-
ing in 2 short acute lobes, the 2 short sides deeply incised,
leaving only a narrow isthmus; width 1632 /*, length with
spines up to 56/1. Wis. G. M. Smith. Europe.

In the typical form, T. tetragonum forma arthr^dcmniforme
G. S. West, 1909, p. 245, PI. CCCXCYIII, fig. i. the apices of
the prolongations are simple.

30. T. VICTORIAB Wolos/yriska, 1914, p. 203, I'l. VI. ligs. 1-4.
Cells 4-lobed, deeply emarginate, forming two subcruciform,
strongly twisted semi-cells; angles rounded, with a shoit
straight spine with blunted tip; cells 20-30 X 10-15^. \\ i^ .
G. M. Smith. Africa.

The original material from Africa had cells with dimensions
as above; Smith's plants from Wisconsin measure 40-60 X
15-20 /*, but do not differ otherwise.

Page 167, cancel all in regard to ELAKATOTifRix, and sul.
stitute,

Cells cylindrical or fusiform, with one parietal chromatophore,
nearly covering the wall, with pyrenoid ; an extensive gelatin-
ous thallus, often branching and anastomosing, including many
cells, usually in longitudinal series ; asexual reproduction }>\
transverse division.

THE GREEN ALGAE OF NORTH AMERICA' 41

KEY TO THE SPECIES OK E^AKATOTHRIX.
i. Sheath little or not branched ; cells narrowly fusiform.

1. E. gelatinosa.
i. Sheath branching and anastomosing ; cells broad fusiform or ovoid.

2. E. americana.

1. E. GELATINOSA Wille, 1898, p. 302; Pascher, 1915, p.
220, figs. 25 & 26. Cells elongate fusiform, 18-22 X 4-6 /*, in
more or less distinct linear series ; gelatinous sheath cylindrical
or subfusiform, little or not at all branched, containing up to
32 cells, rarely more. Fig. 14. Wis., G. M. Smith.

Northern Europe.

2. E. AMERICANA Wille, 1899, p. 150; P. B.-A., No. 607.
Cells broad fusiform or ovoid, 12-25 X 6-15/1; gelatinous
sheath in the form of a laciniate, anastomosing thallus, attached
to various plants and reaching a length of several cm. ; later
forming floating masses of indefinite form. Conn.

Northern Europe.
FUSOLA Snow, 1903, p. 389.

Cells fusiform, parietal chromatophore nearly or quite cover-
ing the wall, with large central pyrenoid ; asexual reproduction
by transverse division of cell, the daughter cells separating and
issuing from the mother cell ; single cells surrounded by a
broad gelatinous coating of similar shape to the cell, containing
2-4 daughter cells during division, then dividing to contain a
single cell. Only one species.

F. VIRIDIS Snow, 1903, p. 389, PI. II, fig. 6 ; Elakatothrix
americana Collins, 1909, fig. 51, not of p. 167. Cells 27-40 X
9-12 /A, broad fusiform, sometimes slightly sigmoid ; sheath
35-60X15-25/4. Lake Erie. Northern Europe.

Pascher, 1915, p. 220, gives Fusola americana Snow as a syno-
nym of Elakatothrix americana ; no such binomial was used.

Page 1 68, after generic description of SCENEDESMUS, cancel
key, and substitute,

A very thorough monograph of this genus, G. M. Smith,
I9i6a, has been utilized for the following account of the American
forms. These are now given in the same order and under the
same names as in the monograph, with descriptions of all not
already described in this work.

KEY TO THE SPECIES OF SCENEDESMUS.
i. Cell membrane smooth, without terminal spines, teeth, granulations

or lateral ridges. 2.

i. Cells with projections of some sort. 8.

2. Cells acicular to fusiform. 3.

2. Cells ovoid. 7-

42 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

3. Cells without polar bulbs or thickenings. 4.

3. Cells with polar bulbs or thickenings. 5. S. incrassatulus.

4. Cells all in one plane. 5.

4. Cells not in one plane. 6.

5. All cells straight. I. 5. obliqmts.

5. Median cells straight, end cells curved. 2. 5. dimorf>hns.

6. Cells alternate, end cells usually not in same plane as others.

3. 5". Bernardii.

6. Cells forming a curved surface. 4. S. acuminatus.

7. Cells in a linear or alternating, not a double series. 6. S. bijuga.
7. Cells in two series. 7. 5. arcuatus.

8. Cells with teeth at poles, but no other projections.

8. S. dcnticulatus.

8. Cells with projections other than teeth. 9.

9. Cells with longitudinal ridges. 10.

9. Cells without ridges. 12.

10. Cells with ridges only. 9. S. acutifortnis.

10. Cells with ridges and other projections. n.

ii. Cells with teeth at poles. 10. S. brasiliensis.

II. End cells with spines. n. S. artnatus.

12. Cells with short spines or granulations. 13.

12. Cells with long spines or horns. 14.

13. Spines or granulations covering the wall. 12. 5. Hystrix.

13. Spines or grahulattons in longitudinal rows. 13. 5. serratus.

14. Spines on all cells. 15.

14. Spines on end cells only. 16.

15. Spines both on poles and middle part of cell. 14. S. abandons.
15. Spines only at poles. 15. 5. longus.

16. Cells in lateral contact throughout. 16. S. quadricauda.

16. Cells in contact for middle third only. 17. S. opoliensis.

1. S. OBLio.uus(Turp.) Kutzing, 1833, p. 609 ; G. M. Smith,
I9i6a, p. 428, PI. XXV, fig. 7; XXIX, figs. 63-68; Collins,
1909, p. 168 ; Achnanthes obliqua Turpin, 1820, fig. 9; 1828,
p. 3I2, PI. XIII, fig. 9.

2. S. DIMORPHUS (Turp.) Kiitzing, 1833, p. 608; G. M.
Smith, I9i6a, p. 434, PI. XXV, fig. 8; XXXII, figs. 185-189;
XXXIII, figs. 190-195 ; 5. obli(juusv*r.dimor/>hitsCo\\\\\st 1909,
p. 169 ; Ach»anthesdimor/>hnsTurv\nt 1820, fig. 2 ; 1828, p. 312,
PI. XIII, fig. 12.

3. S. BKRNAKDII G. M. Smith, I9i6a, p. 436, PI. XXV,
fig. 6; XXXIII, figs. 196-208. Colonies of 2-8 cells ; cells fusi-
form, often sigmoid, 8-16 X 3 7 M ; in a loose alternate series,
attached only near the poles. Wis., G. M. Smith.

4. S. ACUMINATUS (Lagerh.) Chodat, 1902, p. 211 ; Selenas-

THE GREEN ALGAE OF NORTH AMERICA 43

trum acuminatum Lagerheiin, 1882, p. 71, PI. Ill, figs. 27-30;
W. & N., No. 441. Colonies of 4 cells ; cells somewhat lunate,
falcate or sigmoid, apices acuminate ; not in one plane, but as a
more or less curved surface, a median section of the colony
sometimes showing a curvature of as much as 180° ; cells 6-7 /*
thick, apices distant 30-40 /x. Wis., G. M. Smith. Europe.

Smith (in litt.) states that his plant referred to above is certainly
a Scenedesmus, and to be identified with the plant of Lagerheim
and Chodat ; that he has also a true Selenastrum considerably
resembling it. If the same two species occur in Europe, it may
account for some recent authors doubting the validity of Chodat's
transfer of Lagerheim 's species.

Var. MINOR G. M. Smith, I9i6a, p. 436, PI. XXIX, figs. 70-74.
Cells 3.5-6 //. thick, apices distant 18-28 /*. Wis., G. M. Smith.

Var. TETRADESMOIDES G. M. Smith, 19163, p. 439, PI. XXIX,
figs. 75-80. Cells less lunate, 11-15 X 2.5-4 /*, curvature of
colony from slight to nearly a circle. Wis., G. M. Smith.

5. S. INCRASSATULUS Bohlill, 1897, p. 24, PI. I, figs. 45-51 ',

G. M. Smith, 19163, p. 440, PI. XXV, figs. 9-10. Colonies 4-8-
celled, occasionally 2-celled, cells in a single series or alternating,
or somewhat irregular, 17-24 X 5-8 /*; fusiform, subacute with
an apical thickening of the membrane, median cells usually
slightly curved, end cells distinctly so, outer side convex, inner
plane or concave. Stover's Pond, Harpswell, Maine, F. D.
Lambert. Brazil, Burma,

In the Harpswell material the cells are irregularly placed,
showing little seriate arrangement, but otherwise are quite
typical.

Var. MONONAE G. M. Smith, 19163, p. 440, PI. XXIX, figs.
81-83. Cells 11-12 X 4-4.5 M. Wis., G. M. Smith.

Cells more slender than in the typical form, and smaller in all
dimensions.

6. S. BIJUGA (Turp.) Lagerheim, 18933, p. 158 ; Collins,
1909, p. 168; G. M. Smith, 19163, p. 441, PI. XXV, fig. 2;
Achnanthes bij2iga Turpin, 1828, p. 310, PI. XIII, fig. 4.

Vsr. FLEXUOSUS (Lemin.) Collins, 1909, p. 168 ; G. M. Smith,
19163, p. 446, PI. XXV, fig. 10 ; 5. bijugatus V3r. flexuosus
Lemmermann, iSgSb, p. 191, PI. V, fig. i.

V3r. AI/TERNANS (Reinsch) Borge, 1907, p. 57; Collins, 1909,
p. 168; G. M. Smith, 19163, p. 447, PI. XXV, figs. 14-15 ; S.
alternans Reinsch, 1866, p. 135, PI. XX, fig. D. 5.

44 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

Var. IRRBGULARIS (Wille) G. M. Smith, 19163, p. 448, PI.

XXVIII, figs. 59-62 ; 5. bijugatus forma irrcgularis Wille, 19033,
p. 92, fig. 4. Cells irregularly arranged, alternately or in two
series, 7.5-10 X 3.5-6 /*. Wis., G. M. Smith. Europe.

7. S. ARCUATUS Lemmermann, 18993, p. 112, PI. I, figs.
2-4; G. M. Smith, 19163, p. 449, PI. XXVI, figs. 19-20;

XXIX, figs. 94-98 ; XXX, figs. 99-100. Colonies 4-i6-celled,
usually 8, more or less curved, small openings between cells ;
cells in two series, oblong-ovoid or subangulate, 9-15 X 5-9 /*.
Wis., G. M. Smith. Europe.

Var. PLATYDISCA G. M. Smith, 19163, p. 451, PI. XXX, figs.
101-105. Colony usually 8-celled, cells in two series in one
plane, with very small openings, 8-n X 4.5-6/4. Wis., G. M.
Smith.

8. S. DENTICULATUS Lagerheim, 1882, p. 61, PI. II, figs.
13-17; G. M. Smith, 1917, p. 452, PI. XXVI, fig. 23. Colo-
nies 4-celled, cells alternately or subcruciately arranged, ovoid
or ovoid-oblong, apices rounded, with two small teeth, 7-15 X
5-1 1 ft. Wis., G. M. Smith. Europe.

Var. I.INEARIS Hansgirg, 1888, p. 266 ; Collins, 1909, p. 169 ;
G. M. Smith, 19163, p. 454.

9. S. ACUTIFORMIS Schroder, i897b, p. 45, PI. II, fig. 4 ;
G. M. Smith, 19163, p. 456, PI. XXVI, figs. 28-29; XXIX,
figs. 84-89. Colonies 2-8-celled, cells uniseriate, fusiform, end
cells with 4 longitudinal ridges, median cells with 2 each ;
cells 16-22 X 5.5-8 /». Wis., G. M. Smith. Europe.

The number of ridges can best be seen in cross section ; a
side view shows usually only one ridge to a cell.

10. S. BRASILIBNSIS Bolllill, 1897, p. 22, PI. I, figS. 36-37 ;

G. M. Smith, 19163, p. 458, PI. XXVI, figs. 30-31. Colonies
4-8-celled, cells in a single straight series, oblong, obtuse, each
with minute teeth at pole, and four very slender longitudinal
ridges, 11-24 X 8-20/4- Melrose, Mass., C. Bullsrd ; \\ is .
G. M. Smith. Africa^ Asia, So. Am, rim. l-'.nrope.

n. S. ARMATUS (Chod3t) G. M. Smith, 19163, p. 460, PI.
XXVIII, fig. 53; XXIX. figs. 90-93; XXX, figs. 109-110;
S. Hystrix var. armalus Chodat, 1902^ p. 215, fig. 140. Colo-
nies 2-8-celled, cells in 3 straight or subalternate series, ovoid
or oblong-ovoid, end cells with a spine at each pole, median
cells spineless ; all cells with more or less distinct fine lateral
ridges; cells 7-14 X 4-? M, spines 5.5-7 /t long. Wis., G. M.
Smith. Europe.

THE GREEN ALGAE OF NORTH AMERICA 45

Var. CHODATII G. M. Smith, 19163, p. 461, PI. XXX, figs.
111-114. Cells proportionally more slender, notches between
poles deeper; cells 11-15 X 4-5 /*. Wis., G. M. Smith.

Var. SUBALTERNANS G. M. Smith, 19163, p. 461, PI. XXX,
figs. 115-120. Cells subalternately arranged, often pyriform,
3-5-5 /*• Wis., G. M. Smith.

12. S. HYSTRIX lyagerheim, 1882, p. 62, PI. II, fig. 18 ; Col-
lins, 1909, p. 169 ; G. M. Smith, 19163, p. 462, PI. XXVI, fig. 35.

13 S. SERRATUS (Corda) Bohlin, 1901, p. 44, PI. I, fig. 2 ; G.
M. Smith, 19163, p. 465, PI. XXVIII, figs. 55, 57 ; Arthrodesmus
serratus Cords, 1839, p. 244, PI. VI, fig. 35. Colonies 4-celled,
in a single straight series, cells oblong-ovoid, end cells each with
a single longitudinal series of minute teeth, median cells each
with two series : poles of all cells with 3-4 teeth each, cells 15-20
X 4.5-7 M. Wis., G. M. Smith. Austria, Azores.

14. S. ABUNDANS (Kirchner) Chodat, 1913, p. 77 ; G. M.
Smith, 19163, p. 465, PI. XXX, figs. 133-136; PI. XXXI, figs.
137-140; >S. caudatus var. abundans Kirchner, 1878, p. 98; S.
quadticauda var. abundans Collins, 1909, p. 169. Colonies
usually 4-celled, cells ovoid to oblong-ovoid, in- a strsight or
subalternate series ; end cells with spines at poles 3nd between
poles ; medi3n cells with spines at poles only ; cells 8-12 X 4-7 v- \
spines 4-7.5 /* long.

Var. LONGICAUDA G. M. Smith, 19163, p. 467, PI. XXX, figs.
121-125. Cells 7-9 X 3-6 /*; spines 6- 10 p. long. Wis., G. M.
Smith.

Spines longer thsn in the typicsl form, but fewer.

Vsr. SPICATUS (W. & G. S. West) G. M. Smith, 19163, p. 468,
PI. XXVII, fig. 51 ; XXXI, figs. -141-146; S. status W. & G.
S. West, 1898, p. 335. Colonies 2-4-celled, cells in 2-celled
colonies 3nd end cells in 4-celled colonies bearing a longitudinsl
series of 5-7 spines ; median cells of 4-celled colonies bearing 1-2
spines at each pole; cells 7.5-9 X 4 n; spines 2-2.5 /* long-
Wis., G. M. Smith. Europe.

Var. BREVICAUDA G. M. Smith, 19163, p. 468, PI. XXX,
figs. 126-132. Cells smaller, 5-8 X 2.5-5 M ; spines 1.5-3 /* long ;
spines fewer, never 5 on a cell. Wis., G. M. Smith.

V3r. ASYMMETRICA (Schroder) G. M. Smith, 1917, p. 468,
PI. XXVII, figs. 45-46 ; 5*. quadricauda V3r. asymmetrica
Schroder, 1897, p. 45, PI. II, fig. 5. End cells with 3 spine 3t
each pole; every cell with one lateral spine. Wis., G. M.
Smith. Europe.

46 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

15. S. LONGUS Meyen, 1829, p. 774, PI. XLIII, fig. 28;
G. M. Smith, 19163, p. 469, PI. XXVIII, fig. 54 ; XXXI, figs.
156-158; 5". quadricauda forma sefosus and forma horridus Col-
lins, 1909, p. 169. Colony 2-8-celled. cells oblong-cylindric or
ovoid, rounded at each end, with one chromatophore and one
pyrenoid; a single spine at each pole; cells 8-Ji X 4*5 M »
spines 2-4 /A long. Wis., G. M. Smith. Europe.

Occasionally a spine may be wanting of the normal number,
but this is exceptional.

Var. BREVISPINA G. M. Smith, I9i6a, p. 471, PI. XXXI,
figs. 151-155. Cells longer and narrower, 9- 1 1 X 3-5 /* ; spines
shorter, about 2 /*. Wis., G. M. Smith.

Var. MINUTUS G. M. Smith, 19163, p. 471, PI. XXXI, figs.
147-150. Cells smaller, 6.5-8 X 2-3/1; spines 1.5-2 ft long.
Wis., G. M. Smith.

Var. ELLIPTICUS (W. & G. S. West) G. M. Smith, 19163,
p. 472, PI. XXVII, fig. 44; 5. quadricauda var. ellipticus W.
& G. S. West, 18953, p. 83, PI. V, fig. 6 ; Collins, 1909, p. 169.

Var. Naegelii (Br£b.) G. M. Smith in litt., nov. comb ; 5". Nae-
gelii Br£bissou, 1856, p. 158 ; S1. caudatus (?) Nageli, 1849, p. 91,
PI. V, figs. 2, c & d. Cells larger than in the typical form,
18-33 X 7'11 M. spines 15-30 p. long. Colony usually 8-celled,
median cells with usually only one spine each, 3 adjacent cells
with spines at the same end, the 3 other with spines at the
opposite end. Wis., G. M. Smith. l:itropc.

16. S. QUADRICAUDA (Turp.) Krcbisson in Br£bisson &
Godey, 1835, p. 66 ; Collins, 1909. p. 169; G. M. Smith, 19163,
p. 472, PI. XXVII, fig. 39; XXXI, figs. 172-175; XXXIII.
fig. 176; Achnanthes quadricauda Turpin, 1820, fig. n; 1828,
p. 311, PI. XIII, fig. 6.

Var. QUADRISPINA (Chodat) G. M. Smith, 19163, p. 479, PI.
XXVII, fig. 43; XXXI, figs. 167-170; 5. quadrispina Chodat,
1913. P- 58« figs- 45-52. Cells broad ovoid, 8.5-11 X 3.5-6 /*;
spines short. Wis., G. M. Smith. l.uropt.

Var. PARVUS G. M. Smith, 19163, p. 480, PI. XXXI, figs.
162-166. Cells ovoid-cylindric, 5.5-8 X 3 /*; spines 4.5-8 /*
long. Wis., G. M. Smith.

Var. LONGISPINA (Chotlst) G. M. Smith, 19163, p. 480, PI.
XXVII, fig. 42; XXXI, figs. 159-161; S.lonKispina Chodat,
1913, p. 60, figs. 53-58. Cells ovoid-cylindric, 8-n X 3.5-5 /*;
spines 7.5-14 M long. Wis., G. M. Smith. Europe.

The spines are 11-14 M long in the European plant, 7.5-9.5 M
in the American.

THE GREEN ALGAE OF NORTH AMERICA 47

Var. WESTII G. M. Smith, igi6a, p. 480, PI. XXXIII, figs.
177-180. Cells 16-22 X 4.5-8 p.; spines 12-16 ft long. Wis.,
G. M. Smith.

A large form, but in its maximum not reaching the minimum
of var. maximus.

Var. MAXIMUS W. & G. S. West, 18953, p. 83, PI. V, figs.
9-10 ; G. M. Smith, 19163, p. 481, PI. XXVII, fig. 40. Cells
twice as large as in the typical form, 27-36 X 9-11.4 /*, with
long curved spines. Waltham, Mass., F. D. Lambert.

Europe, Africa, Asia.

17. S. OPOLIENSIS Richter, 1896, p. 7, fig. A-E ; G. M.
Smith, 19163, p. 481, PL XXVII, fig. 49; XXXII, figs. 181-
184. Colonies 2-4-celled, cells in a straight series, end cells
fusiform or subnavicular, with a long spine at each pole ;
median cells regularly fusiform, usually unarmed ; cells united
for about the median third only; cells 17-28 X 5-8 p. ; Lske
Erie, Snow; Wis., G. M. Smith. Europe.

The chsracters just given are the normal for the species, but
there is much variation as to the size 3nd number of the spines ;
they are never entirely wanting, and on the other hand are
never present on all the poles in the colony.

Page 170, for description of CRUCIGENIA, substitute.

Colonies free, of 4-8-16, rarely more cells, lying in the same
plane, with perforations at places where the cells have divided
and separated from each other; cells with parietal chromato-
phore, with or without pyrenoid, touching at the middle or at
the edges, and enclosed in more or less plentiful gelatine ; asex-
ual reproduction by division of a cell into 4 daughter cells,
arranged like the mother colony. Fresh water plankton 3lg3e.

KEY TO THE SPECIES OF CRUCIGENIA.

i. Cells with more or less rounded outline. 4.

i. Cells more distinctly angular. 2.

2. Cells triangular. 6.. C. tetrapedia.

2. Cells not triangular. 3.

3. Cells rhomboidal, sides concave. 2. C. crucifera.

3. Cells trapeziform. 7- C.fcnestrata.

4. Cells quadrate with rounded corners, or suborbicular.

3. C. quadrata.

4. Cells oval, oblong or subtriangular. 5.

5. Colonies of 4 cells, separating soon after division.

i. C. rectangularis.
5. 4-celled colonies remaining united. 6.

48 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

6. Colonies united by short gelatinous bands. 4. C. Lauterbomi.
6. Colonies united in extensive flat sheets. 5. C. irregularis.

1. C. RBCTANGULARis(A. Br.)Gay, 1891, p. ioo, PI. XV, fig.
151 ; W. & N., Alg. Exsicc. Nos. 53, 171 ; Staurogenia rect-
angularis A. Braun, 1855, p. 70. Cells 4-6 X 5-7 /*, oval or
oblong, united in fours, touching near the outer end, or curved
and touching near the middle. Greenland, Mass., Wis. Europe.

2. C. CRUCIKERA (Wolle) Collins, 1909, p. 170; Staurogenia
frua/era Wolle, 1877, p. 140 ; S. cruciata Wolle, 1887, p. 171, PI.
CLVII, figs. 9-1 1. Cells rhomboidal, equilateral, with incurved
sides and rounded angles, four forming a colony of the same form
as the individual cell ; " cells with a cruciform marking on the
surface." Wolle.

Since Wolle's imperfect description and rudimentary figures,
no information has been obtained as to this species, until its re-
discovery by G. M. Smith, who found it in Tenderfoot Lake,
Wis., June, 1917.

3. C. QUADRATA Morreii, 1830, p. 413, PI. XV, figs. 1-5 ;
including C. triangulaiis (Chodat) Schmidle, 1900, p. 234.
Cells quadrate, 3-4 /* square, with more or less rounded corners,
or subcircular, united in regular, quadrate, 4-celled colonies.
Wis., G. M. Smith. /:/</«>/>'.

4. C. LAUTKRHORNI (Schmidle) Chodat, 1902, p. 206, fig.
127; Staurogenia Lauterbomi Schmidle, 1896, p. 192, fig. i.
Cells arranged as in C. rectangularis, 6 X 3-4 M, the 4 celled
colonies united in groups of 8-32 by short gelatinous projections.
Wis., G. M. Smith. l:urope.

5. C. IRREGULARIS Wille, 1898, p. 302. Cells 6-14 X 4-9 M»
united as in C. rectangnlaris, but more irregularly, and more
cells to a colony, 45-90 /* diam. ; the colonies united by gelatine
into a flat or undulate expansion. Wis., G. M. Smith. Europe.

6. C. TRTRAPBDIA ( Kirchner) W. & G. S. West, 1902.
p. 62; Pascher, 1915, p. 174, fig. 251 ; Staurogenia f tclrapedia
Kirchner, i88o,'Pl. II. fig. i. Colony 4-celled, plane, quad-
rangular, cells in close contact, each a right-angled triangle,
the outer side (opposite the right angle) somewhat concave,
cells about 5-10/1 long; colonies united 4-16, individual cells
assuming a quadrangular shape before division, the division
diagonal. Chromatophore parietal, without pyrenoid. Wis.,
G. M. Smith. Europe.

7. C. PENRSTRATA Schmidle, 19003, p. 234 ; Pascher, 1915,
p. 174, fig. 252. Cells trape/iform, 6-8 X 2-3 /*i colonies 4-celled,

THE GREEN ALGAE OF NORTH AMERICA 49

plane, exactly quadrate with squarish central opening ; included
in an indistinct gelatinous layer ; division on the diagonals of
the quadrate colony. Wis., G. M. Smith. Europe.

ACTINASTRUM L/agerheim, 1882, p. 70.

Cells ovoid to clavate or'subcylindrical, radiately attached by
their apices to form small colonies, which often remain attached ;
chromatophore parietal, with or without pyrenoid ; asexual re-
production by longitudinal and transverse division.

KEY TO THE SPECIES OK ACTINASTRUM.
i. Cells elongate-clavate, 10-24 X 3-6 //, with pyrenoid.

i . A. Ha ntzsch it.
i. Cells nearly cylindrical, 14-18 X 1.75-2 M, without pyrenoid.

2. A . gracillimum.

1. A. HANTZSCHII L,agerheim, 1882, p. 70, PI. Ill, figs.
25-26. Colonies usually 4-celled ; cells elongate-clavate, 10-
24 X 3-6 fj., with one pyrenoid, apices attenuate or acuminate,
membrane delicate, hyaline. St. Louis, Mo., Ada Hayden,
1910, p. 43. Europe.

2. A. GRACILLIMUM G. M. Smith, 1916, p. 480, PI. XXVI,
fig. 23. Colonies 4-8-celled, cells elongate cylindrical or slightly
tapering, 14-18 X 1-75-2 /*, without pyrenoid. Wis., G. M.
Smith.

Page 80 of supplement, cancel ACTINASTRUM.

Page 171, after description of KIRCHNERIELLA, insert,

KEY TO THE SPECIES OF KIRCHNERIELLA.

i. Cells lunate or reniform. 2.

i. Cells cylindrical, curved or twisted. 3.

2. Ends of cells pointed, distant. i. K. lunaris.

2. Ends of cells blunt, approximate. 2. K. obesa.

3. Cells 8-10 /J. loug; ends usually recurved. 3. K. contorta.

3. Cells 15-25 /xlong, spirally or irregularly twisted. 4. K. elongata.

After description of Var. DIANAE, add,

3. K. CONTORTA (Schmidle) Bohlin, 1897, P- 2O J K. obesa
var. contorta Schmidle, 1894, p. 44, PI. VII, fig. 2. Cells cylin-
drical with rounded ends, 8-10 X 0.7-2 /x, the ends hooked and
curved. Wis., G. M. Smith. Europe.

4. K. ELONGATA G. M. Smith, 1916, p. 473, PI. XXIV,
fig. 7. Colonies of 4, 8, 16 or many cells imbedded in a copious
homogeneous matrix ; cells cylindrical, rounded at ends, spirally
or irregularly twisted into a knot-like snarl ; chromatophore
parietal, without (?) pyrenoid; cells 15-25 X 2-2.75 /A, colonies
up to 100 /j. diam. Wis., G. M. Smith.

50 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

Page 80 of supplement, after description of KIRCHXKKIKLLA
OBHSA, add,

Var. APERTA (Teiling) Brunnthaler in Pascher, 1915, p. 182 ;
K. aperta Teiling, 1912, p. 276, fig. 9. Differs from the type
by the acute-angled incision, being in this respect intermediate
between K. /unaris and K. obesa ; dimensions the same as in
K. obesa ; apices blunt. Wis., G. M. Smith. Europe.

Page 172, for Key to the Species of Coelastrum, substitute,

i. Cells united by arm-like processes from the membrane.

5. C. reticulatum.
I. Cells in contact or united by quite short processes. 2.

2. Cells without external projections. 3.

2. Cells with external projections. 4.

3. Cells spherical or slightly elongate, interspaces small.

i. C. microporunt.
3. Cells ovoid, mutually compressed, interspaces >£-i cell diani.

2. C. sphaericum.

4. Bach cell normally with one projection. 5.

4. Bach cell normally with several projections. 6.

5. External view of cell hexagonal. 3. C. proboscidfum.

5. External view of cell io-12-angled. 4. C. cambricum.

6. E»ch cell with 3 polar projections. 48. C. cubicum.

6. Bach cell with several irregularly placed projections.

6. C. verrucosum.

Page 173, after description of C. CAMBRICUM, add,

Var. INTERMEDIUM (Bohlin) G. S. West, 1907, p. 136 ; C. pul-

chrum var. intermedium Bohlin, 1897, p. 35, PI. II, figs. 16-17.

Projections broader and less acute than in the typical form.

Fla., Borge.

Page 173, after description of C. RETicuLATUM.'add,
C. SCABRUM Reinsch, 1877, p. 232 ; Printz, 1913, p. 90, PI.
VII, fig. 192 ; Brunnthaler in Pascher, 1915, p. 197, fig. 316.
Colonies spherical or subcubical, of 8-16 cells; cells spherical,
8-io/idiam., each with 3-6 firm, regularly arranged truncate
prolongations, punctulate at the apex. Mackinaw, Mich.,
Transeau. South Africa.

PHYTOMORULA Kofoid, 1914, p. 38.

Colony of 16 cells, 4 cells in the same plane being superim-
posed on 4 other similar cells, also in one plane, the group of 8
being surrounded by a ring of 8 cells. Chromatophore parietal,
with numerous minute pyrenoids and central nucleus. Repro-
duction unknown.

THE GREEN ALGAE OF NORTH AMERICA 51

P. REGULARIS Kofoid, 1914, p. 38, PI. VII. Colony solid,
flattened, orbiculate, the peripheral cells broadly cuneate, the
other cells squarish in surface view of the colony, 10-15 A* wide ;
each cell with a slight external projection. The only species,
found in a fresh water reservoir at Berkeley, California. Fig. 15.
C. A. Kofoid.

The peculiar arrangement of the cells is better understood by
the figures than by description. The colony may be considered
as a sphere much compressed in the line of the polar axis, the
two polar groups of four cells each coming in contact, the equa-
torial cells forming a ring, fitting into the groove around the
group of eight, "like an automobile tire into the rim of the
wheel," in the words of Kofoid.

Page 173, for Key to the Species of Sorastrum, substitute,

i. Outer angles of cells rounded, each with 2 spines. 2.

i. Outer angles ending each in a short, conical point.

2. S. bidentatum.
2. Cells as long as broad or longer. 3. 6". americanum.

2. Cells broader than long. i. 5". spinulosutn.

After description of S. SPINULOSUM, add,

Var. HATHORIS (Cohn) Lemmerman * ; Selenosphaerium
hathoris Cohn, 1879, p. 13, PI. XI, figs. 16-17. Cells 16-20 ft
wide, 10 [i. high and thick, central body more distinct than in
the typical form. Pa., West. Europe.

After description of S. BIDENTATUM, add,

3. S. AMERICANUM (Bohlin) Schmidle, 18993, p. 230, fig. 6 ;
Selenosphaerium americanum Bohlin, 1897, p. 40, PI. II, figs.
38, 41. Cells as long as broad or longer, obcordate or obpyra-
midal, with stout gelatinous stipe attaching to distinct central
body of colony ; cells 8-15 X 6-8 \L ; colony 22-60 \L diam., with-
out spines. Wis., G. M. Smith. Europe, So. America.

Page 175. Cancel paragraph beginning "The European
D. Luna/us" and substitute,

2. D. LUNATUS A. Braun, 1855, p. 44; Rabenhorsf, 1868,
p. 36, fig. 7. Inner cells ovoid-ellipsoid, outer lunate; cells
10-20 p. long, colonies up to 100/4 diam. Wis., G. M. Smith;
Fla., Borge. Europe.

After paragraphs referring to DICTYOCYSTIS, add, . '
*Fide Brunnthaler in Pascher, 1915, p. 201.

52 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

TETRADBSMUS, G. M. Smith, 1913, p. 76.

Colonies free, of four cells in two planes, the cells in one
plane laterally united to those in the other plane ; reproduction
by autocolonies. Otherwise like Scencdesmus.

T. WISCONSINENSIS G. M. Smith, 1913, p. 76, PI. I. Cells
ovoid, ends sharply pointed, 4-6 X 12-15 /*• Fig. f6. Madi-
son, Wis., G. M. Smith.

WESTELLA De Wildeman, 1897, p. 532.

Families of four cells in one plane ; cells spherical or sub-
spherical, rarely somewhat angular, with bell-shaped chromato-
phore. Families united by gelatinous threads, the remnants of
mother cell walls, into aggregates of 20-80 cells. Vegetative
reproduction by division in two planes, the daughter cells
(autospores) escaping from the dissolving wall.

W. BOTRYOIDES (W. West) De Wildeman, 1897, p. 532;

Tetracoccits botryoides W. West, 1892, p. 735, PI. X, figs. 43-48.

Cells 3. 5-8 n diam. ; aggregates 30-84 /* diam. Fig. 17. Wis.,

G. M. Smith. Europe.

TBTRASTRUM Chodat, iSgsa, p. 114.

Similar to Crutigenia, but with projections from the edges of
the cells.

KRY TO THE Si'RciRS OF TRTRASTKIM.

i. Cells each with one low protuberance. i. T. apiculatum.

i. Cell* each with several fine spines. a. T. staurogeniaeforme.

1. T. APICULATUM. (Lemtn.) Schmidle, 1900, p. 154 ; Stauro-
genia apiculala Lemmermann, 18983, p. 151 ; Crucigcnia apicu-
lala Collins, 1909, p. 170. Lake Erie, Snow; Wis, G. M.
Smith. Europe.

2. T. STAUROGBNIAEFORMK (Schroder) Chodat, 1902, p. 208,
fig. 148; Cohniflla staurogeniaeformis Schroder, 18973, p. 273,
IM. XVII, figs. 5-6. Cells subsemicircular, each bearing about
5 hyaline spines ; cells 5-6 ft long. Fig. 18. Wis., G. M. Smith

l-liiropt.

Page 176, after three paragraphs of PBDIASTRUM, add
Within the past four years two papers have been published,
in which this genus has been carefully presented ; but the two
arrive at very different results. Nitardy, 1914, consolidates
species and forms relentlessly and somewhat contemptuously ;
Brunnthaler in Pascher, 1915, while acknowledging the great
variability, does not consider that we have enough data to decide
whit should be considered permanent and what due to environ-
ment. The names used in the 1909 paper have not been changed

THE GREEN ALGAE OF NORTH AMERICA 53

here, but American forms and species reported since then have
been added.

Page 176, for Key to the Species of Pediastrum, substitute,

i. Marginal cells undivided, cuspidate. 8.

I. Marginal cells bilobed. 2.

2. Lobes of marginal cells simple. 3.

2. Lobes of marginal cells emarginate, bidentate or bifid. 7.

3. Disk continuous. 4.

3. Disk perforate. n.

4. Lobes of marginal cells incurved, forcipate. 3. P. forcipalum.

4. Lobes of marginal cells straight or nearly so. 5.

5. Margin finely tuberculate-crenulate. 5. P. vagum.

5. Margin not tuberculate-crenulate. 6.

6. Lobes ending in short, broadly triangular teeth. 12.

6. Lobes ending in linear projections. 13.

7. Disk continuous. 8. P. tetras.

7. Disk perforate. 9. P. biradiatum.

8. Marginal cells with a single tooth or cusp. i. P. simplex.

8. Marginal cells with more than one tooth or cusp. 9.

9. Marginal cells tridentate. 2. P. tricornutum.

9. Marginal cells with two projections. 10.

10. Projections in one plane, short, distant. 10. P. integrum.

10. Projections long, not in the same plane. n. P. Kawrayskii.
ii. Cell wall with a network of very fine ridges. 12. P. sculptatum.
ii. Without network. 7. P. duplex.

12. Cell wall with a rather coarse network of ridges.

13. P. araneosum.

12. Without network. 6. P. angulosuin.

13. Prolongations capitate. 14. P, glandulifertim.

13. Prolongations not capitate. 4. P. Boryanum.

Page 178, after description of P. BORYANUM, add,

Var. LONGICORNE Reinsch, 1867, p. 96. Marginal cells with
rounded lobes, each extended in a usually incurved projection,
15-30 /u. long. Greenland, Richter. Europe,

Page 179, after description- of P. DUPLEX, add,

Var. ASPERUM A. Braun, 1855, p. 93. Cells 8-64, up to 35 p.
wide, prolongations short, rough or toothed. Fla., Borge.

Europe.

Var. CORNUTUM Raciborski, 1890, p. 101. Cells slightly at-
tached, openings irregular, not rounded ; marginal cells sub-
cordate, each lobe ending in a long, straight, cylindrical pro-
longation. Fla., Borge. Europe.

54 TI-FTS COLLEGE STUDIES, VOL. IV, No. 7

Var. RETICULATUM Lagerheim, 1882, p. 56, PI. II, fig. i.
Colonies of 8-16 cells; all cells strongly emarginate, openings
large, rounded. Wis., G. M. Smith. Europe.

Var. GRACILLIMUM W. & G. S. West, 18950, p. 52. Colony
up to 87 p. diani. ; cells very slender, marginal cells arcuate,
with two long, slender processes, emarginate at the apex ; other
cells 4-radiate, with very large openings. Wis., G. M. Smith.

Page 179, after description of Var. EMARGINATUM, add,

10. P. INTEGRUM Nageli, 1849, p. 96, PI. V. B. Disk con-
tinuous, rounded, cells 4-32, disk up to TOO /* diam., cells
usually irregularly placed, marginal cells differing little from
disk cells, 5-6-angled, 20-28 /* diam., marginal cells eacli with
two short, blunt, distant prolongations. Wis., G. M. Smith.

Europe.

11. P. KAWRAYSKII Schtnidle, i897a, p. 269; Brunnthaler
in Pascher, 1915, p. 103, fig. 63. Disk continuous, rounded,
disk cells often irregular, 5-6-angled, 10-12 /i diam. ; marginal
cells about 14 /* wide, with two rather large, smooth, straight,
truncate projections, not in the same plane, often crossing,
sometimes one or both wanting. Wis., G. M. Smith. Europe.

12. P. SCULPTATUM G. M. Smith, 1916, p. 475, PI. XXV,
fig. 13. Disk oval or circular, 8-32-celled ; disk cells 4-6-sided,
with few openings ; marginal cells bilobed, the lobes produced
into divergent or parallel horn-like processes. Cell wall covered
with a network of very fine ridges; disk 80-150 /* diam., cells
10-15 /*• Wis., G. M. Smith.

13. P. ARANEOSUM Raciborski, var. rugulosum (G. S. West)
G. M. Smith, 1916, p. 476, PI. XXV, fig. 14; P. Boryanum
var. rugulosum G. S. West, 1907, p. 132, PI. V, fig. 22. Disk
1 50-200 /* diam. . cells 22-29 /A; margins of cells irregularly wavy,
surface with wavy ridges. Wis., G. M. Smith. Europe.

Typical P. araneosum Raciborski, 1890, p. n, has not been
reported from America.

14. P. GLANDULIFBRUM Bennett, 1892, p. 7, PI. II, figs. 5-7.
Colonies elliptical, continuous or with very small openings ;
marginal cells 5-6-angled, 10 p wide, 12 /* long, with a small
semicircular incision, with two projections from each cell, about
midway between side of cell and incision, projections about 15 n
long, filiform, distinctly capitate. Wis.. G. M. Smith. Europe.

3. EUASTROPSIS Lagerheim, iSgsa, p. 20.
Colonies 2-celled, flat, in one plane, membrane thin and
smooth ; chromatophore a parietal disk with one pyrenoid ;
asexual reproduction by zoospores 2-many in a cell, formed by

THE GREEN ALGAE OF NORTH AMERICA 55

successive division, ovoid, with 2 cilia, escaping in a gelatinous
vesicle by an opening in the mother cell wall, and after coming
to rest forming 1-16 new colonies.

1. E. RICHTERI (Schmidle) Lagerheim, 18950., p. 20, PI. I,
figs. 12-27 J Euastrum Richteri Schmidle, 1894, p. 60, PI. VII,
fig. 25. Cells trapezoid, strongly emarginate, 5-20 X 4.5-25 n ;
colonies 10-40 X 6-25 fi; zoospores 5 p. diam. Fig. 19. Wis.,
G. M. Smith. Europe.

Page 187, add,

GEMINELLA Turpin, 1828, p. 329.

Cells ovoid-cylindric to short-cylindric, normally in a single
series in a wide, homogeneous gelatinous sheath ; chromato-
phore zonate with one pyrenoid ; asexual reproduction by cell
division, the daughter cells usually remaining approximate ;
zoospores unknown ; akinetes in some species.

The generic name Hormospora is antedated by Geminella. It
is now generally recognized that in addition to the Hormospora-
forms assumed by some species of Ulothrix, etc., there are
autonomous forms with the characters of the genus. It is a
question whether Radio/Hum is distinct ; the only distinguishing
character now available is the structure of the sheath, homo-
geneous or longitudinally laminate in Geminella, transversely
in Radio/Hum. Wille, 1909, p. 72, has Hormospora and Radio/Hum
as sections of Geminella. In none of the species is the life his-
tory fully known, so for the present the two genera are retained.

KEY TO THE SPECIES OF GEMINELLA.

i. Cells transversely elongate. i. G. scalariformis.

i. Cells longitudinally elongate. 2. G. interrupta.

Page 188, for HORMOSPORA SCALARIFORMIS read,
GEMINELLA scalariformis G. S. West ms. ; Hormospora

scalariformis G. S. West, 1905, p. 282, PI. CCCLXIV, figs. 6-7.

Fig. 21.

After description of GEMINELLA SCALARIFORMIS, add,
Forma MARINA G. S. West in Collins & Hervey, 1917, p. 31.

Cells proportionally longer, sheath more homogeneous. In salt

water, Bermuda, Collins.

2. G. INTERRUPTA Turpin, 1828, p. 329, PI. XIII, fig. 24 ;
emend. Lagerheim, 1883, p. 68, PI. I. figs. 30-35. Cells 5-7 /x
diam., 6-15 /«. long, in a single series ; sheath 16-18 p. diam. ;
cells from recent division remaining approximate ; akinetes
9-10 p. diam., to 15 /x long, with thick, dark wall. Wis., G. M.
Smith, New Buffalo, Mich., Transeau. Europe.

56 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

Page 189, add to generic description of RADIOFILUM,
With more or less distinct transverse lamellate or fibrillosc
structure.

KKY TO TOE SPECIES OF RADIOFILUM.

i. Cell division transverse only ; cells nniseriate. 2.

i. Cell division transverse and longitudinal; cells uni-tuultiseriate,

sheath often branched. 4. R. irregulare.

2. Sheaths wide, of inner laminate and outer homogeneous layers.

2. K. conjunctiva in.

2. Sheath of uniform laminate structure. 3.

3. Cells lenticular with sharp lateral edge. I. R. apicvlaluni.

3. Cells spherical or ellipsoid. 4.

4. Sheaths cylindrical, cells broadly ellipsoid. 3. R.Jiavcscens.

4. Sheaths torulose, cells subspherical. 5. A', motiili/onnc.

1. R. APICULATUM see p. 188.

2. R. CONJUNCTIVUM Schmidle, 1894, p. 48, PI. VII, figs.
4-5. Filaments usually short and fragile ; cells spherical or
depressed-spherical, with more or less distinct and sharp lateral
edge, usually 6 X 4 /*, united by short gelatinous Lands, of
firmer consistency than the general sheath ; sheath about 25 /«
diani., with a thin homogeneous outer layer, and an inner layer,
distinctly laminate transversely. Wis., G. M. Smith. Europe.

3. R. KLAVBSCBNS G. S. West, 1899, p. 57, PI. CCCXCV,
figs. 10, ii. Cells broadly ellipsoid, 7.5-10.5 n diam., color yel-
lowish green ; sheath not much wider than cells, more or less
distinctly laminate. Wis., G. M. Smith; Twin Lake. Mich.,
Transeau. Europe.

4. R. IRRKC.UI.ARK (Wille) Bruntithaler * ; Ulothrix (/for-
mosfiora) irrcgularis Wille, 1880, p. 63, PI. II, figs. 41-42.
Cells ellipsoid, 12-15 M wide, 4-6 ft, long, dividing both laterally
and longitudinally ; sheath up to 30 /x wide, lamination more or
less distinct ; by the division of the cells the sheath may con-
tain two or several series, or the sheath may divide into two or
more series each, either reuniting to form a single sheath, or
forming an ordinary branch. Cuttyhunk, Mass., Miss J. M.
Furber ; Carp Lake, Kmmet Co., Mich., Transeau. Europe.

5. R. MONILIPORMH Collins & Furher ms.t Cells sub-
spherical, sheath moniliform. following the shape of the cells.
Cuttyhunk, Mass., Miss J. M. Furber.

•So quoted by Heering in Pascher, 1914, p. 40, but without reference,
t Unpublished species; this note not a publication.

THE GREEN AI.GAE OF NORTH AMERICA 57

P. 219, for No. i of Key to the Species of Prasiola, substitute,

i. Marine. ia.

i. Fresh water or terrestrial. 2.

ia. Frond 33-45 /* thick, with or without stipe. 4. P. borealis.

ia. Frond 10-15 fj. thick, with long distinct stipe. 6. P. stipitata.

P. 221, after account of P. CRISPA, add,

6. P. STIPITATA Suhr in Jessen, 1848, p. 16, PI. Ill, figs.
11-16; I. F. L/ewis, 1916, p. 90, figs. 1-2. Fronds tufted, sev-
eral from the same base, stipe long, slender, at extreme base of
only a single series of cells, widening and increasing in number
of cells, finally expanding into a cordate-cuneate frond, up to
5 mm. long. Cells of frond, before dividing, 6-io/x square, in
quite regular and distinct square areas ; cells in stipe larger
and more distant, in regular longitudinal and transverse series,
but not forming areas. In dense masses on rocks at high tide.
Woods Hole, Mass., I. F. Lewis. Europe.

Page 221, after the generic description of GAVEI^A, insert,

KEY TO THE SPECIES OF GAYEHA.
i. Fronds with deep regular constrictions and n6 rhizoids.

2. G. constricta.
i. Fronds cylindrical or somewhat irregular, with abundant rhizoids.

i. G.polyrhiza.

In description of G. POLYRHIZA, change "parietal " to read
"stellate" chromatophores.

Page 222, after account of G. POLYRHIZA, add,

2. G. CONSTRICTA Setchell & Gardner in Gardner, 1917,
p. 384, PI. XXXII, fig. 5 ; XXXIII, figs. 5-9. Frond similar
to that of G. polyrhiza, but curved and uncinate, and with fre-
quent deep constrictions at fairly regular intervals, each con-
striction caused by the failure of a certain group of primary
cells, usually 2-6 in a group, to divide vertically. A few very
slight rhizoidal projections at the extreme base, no other rhi-
zoids; primary filament about 2o//.diam., upper part of frond
up to 150 jt*, intervals between constrictions 200 p. to i mm.
Cal., N. Iy. Gardner.

This new species, quite distinct from G. polyrhiza, certainly
supports the validity of the genus. Prasiola borealis grows in
the neighborhood, but no intermediate forms have been found.
It seems to be a case where the conditions that favor Prasiola
favor also the nearly related Gayella.

58 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

Page 225 and p. 83 of supplement, tor Key to the Species of
Oedogonium,* substitute,

i. Mac rand rons. 2.

I. Nannandrous. 59.
2. Oogonium opening by a pore. 3.
2. Oogonium opening by a lid. 40.

3. Spore globose. 4.

3. Spore ellipsoid. 21.

4. Pore median. 5.

4. Pore supramedian.

4. Pore superior. 13.

5. Membrane of oospore smooth . 6.

5. Membrane of oospore pitted. 92.

5. Membrane of oospore spinous. 4. Of. succicum.*

6. Monoecious. 94.

6. Dioecious. 7.

7. Oogonia 22-25 M diam. 2. Oe. ru/fscens.

7. Oogonia 30.38 M diam. 2. Oe. socialt.

8. Pore slightly above the middle. 9.

8. Pore almost superior. n.

9. Monoecious. 10.

9. Dioecious. 7. Of. cardiacunt.

10. Oogonium subglobose or subdepressed-globose. 5. Of. obsoletiim.

10. Oogonium snbglobose or subellipsoid globose.

6. Oe. plusiosporum.

II. Monoecious. 12.
II. Dioecious. 8. Oe. franklinianutH.

12. Oospore 31-41 n diam. ; suffultory cell not swollen.

9. Of. various.

12. Oospore 40-48 Mdiani. ; suffultory cell swollen. 76. Of. tyrolicum.
13. Oogonium manifestly swollen. 14.

13. Oogonium little if any swollen. 19.

14. Membrane of oospore smooth. 15.

14. Membrane of oospore pitted. 93.

15. Monoecious. 16.

15. Dioecious. 12. Of. plagiostotnntn.

16. Vegetative cells less than 18 M diam. 17.

16. Vegetative cells 20-30 M diam. n. Oe. Vaucherii.

•89. Oe. Reinschii, fructification unknown, is not included in thin
key ; The hexagonal-appearing cells are characteristic.

t Descriptions of species with serial numbers from 1-74 will be found on
p. 229 and following pages of Collins, 1909; species with letters a or b
after their serial number are described on p. 84 and following pages of
Collins, 1912: species from 75 upare described on the pages immediately
following this key.

THE GREEN ALGAE OP NORTH AMERICA 59

17. Oogonium 40 ^ diam. or less. 18.

17. Oogonium 42-50 M diam. 10. Oe. fragile.

18. Vegetative cells 10-14 /* diam. loa. Oe. giobosum.

18. Vegetative cells 15-18 M diam. 75. Oe. intermedium.

19. Monoecious. 14. Oe. geniculatum.

19. Dioecious. 20.

20. Oogonium one-third to one-half wider than vegetative cells.

15. Oe. capilliforme.

20. Oogonium scarcely wider than vegetative cells. 16. Oe.capillare.
21. Oogonium swollen to twice the diam. of filament or more. 22.
21. Oogonium less swollen ; average less than double the filament. 33.

22. Membrane of oospore smooth. 23.

22. Membrane of oospore ribbed or pitted. 27.

23. Monoecious. 25.

23. Dioecious. 24.

24. Vegetative eel Is 25-30 n diam. 7. Oe. cardiacum var. carbonicum.

24. Vegetative cells 35-45 M diam. 19. Oe. rivulare.

25. Division of antheridial cell vertical. 17. Oe. upsaliense.

25. Division of antheridial cell horizontal. 26.

26. Oogonium largest near base, oospore filling lower part.

2ia. Oe. pseudoboscii.

26. Oogonium ellipsoid, quite filled by oospore.

18. Oe. Richterianum.

27. Membrane of oospore ribbed. 28.

27. Membrane of oospore areolate or pitted. 31.

28. Ribs continuous and entire. 29.

28. Ribs not continuous and entire. 30.

29. Monoecious. 20. Oe. paludosum.

29. Dioecious. 21. Oe. Boscii.

30. Ribs composed of elongate dots. 22. Oe. margaritiferum.

30. Ribs distinctly dentate. 23. Oe. crenulato-costatum.

31. Membrane of oospore areolate.

23. Oe. crenulato-costatum. var. aureum.
31. Membrane of oospore pitted. 32.

32. Oogonium 38-48 M diam. 25. Oe. punctatum.

32. Oogonium 70-83 M diam. 24. Oe. taphrosporum.

33. Membrane of oospore smooth. 34.

33. Membrane of oospore pitted. 70. Oe. giganteum.

34. Monoecious. 26. Oe. martinicense.

34. Dioecious. 35-

35. Oogonium usually 65-75 M diam., rarely to 63 M. 36-

35. Oogonium 65 M diam. or less. 37.

36. Vegetative cells 31-40 M diarn. 27. Oe. Landsboroughii.

36. Vegetative cells 40-49 /* diam. 88. Oe. crassum.

37. Vegetative cells 3-9 diam. long. 38.

37- Vegetative cells 1.75-3 diam. long. 31. Oe. mexicanum.

6o

TUFTS COLLKGE STUDIES, VOL. IV, No. 7

38. Oogoninm oboviform. 28. Oe. obovi/orme.

38. Oogonium snboboviform to obovi form-ellipsoid. 39.

39. Male plants stouter than female. 29. Oe. pachyandrium.

39. Male plants more slender than female. 30. Oe. grande.

40. Oospore globose. 41.

40. Oospore ellipsoid. 53.

41. Division of oogoninm median or subtnedian. 42.

41. Division of oogoninm superior. 47.

42. Cells with spiral markings. 32. Oe. punclato-slriatum.

42. Cells without spiral markings. 43.

43. Oogonium with a whorl of projections.
43- Oogoninm without whorl of projections.

44. Projections mammiform.

44. Projections blunt-conical.
45. Monoecious.
45. Dioecious.

46. Oospore 20-24 M diam.

46. Oospore 25-29 M diam.

46. Oospore 32-38 n diam.
47. Monoecious.
47. Dioecious.

48. Vegetative cells with 3 nodulose swellings.

48. Vegetative cells cylindrical.
49. Oogoninm pyriform or subpyriform.
49. Oogonium oboviform-globose to subglobose.

50. Oogonium 26-30 M diam.

50. Oogonium 40-45 M diam.
51. Oogoninm distinctly swollen.
51. Oogonium little swollen.

$2. Vegetative cells 15 M diam. or less.

52. Vegetative cells 16 M diam. or more.
53. Membrane of oospore smooth.
53. Membrane of oospore ribbed.

54. Oogonium oblong-ellipsoid or biconic.

54. Oogonium pyriform.
55. Ribs 30-35.
55. Rib* 15-19.

56. Vegetative cells 3-7 M diam.

56. .Vegetative cells 10-18 M diam.
57. Oogonium biconic to subglobose.
57. Oogoninm elongate-ellipsoid.

58. Oogoninm 14-19 M diam.

58. Oogoninm 23-28 ** diam.
59. Dwarf males pluricellnlar.
59. Dwarf males unicellular.

44-
45-

388. Oe. tttantntifcrum.
38b. Oe. Itzigsohnii.
77. Of. actnandriuni.
46.

78. Oe. consociatutn.
33. Oe. Howardii.
79. Oe. pratense.
48.

38. Oe. Pringsheimii.
41. Oe. nodulosutn.
49-
50.

34. Of. l*ithophorae .
71. Oe. pyriforme.
52.

37. Oe. autumnale.
35. Oe. cri sftum.
36. Oe. obesum.
54-
55-
56.

. Oe. sanctae-thoniae.
42. Oe. nob He.
. Oe. pauco-costatum.

57-

39. Of. Ahhtrandii.
7oa. Oe.pusillum.
58.

40. Oe. gracillimu m .
81. Oe. obloHgum.
60.
87.

THE GREEN ALGAE OF NORTH AMERICA

61

60. Antheridium exterior.

60. Antheridium interior.
61. Oogonium opening by a pore.
61. Oogonium opening by a lid.

62. Oospore globose.

62. Oospore ellipsoid.
63. Pore median or slightly above.
63. Pore superior.
63. Pore inferior.

64. Membrane of oospore smooth.

64. Membrane of oospore spinous or ribbed.
65. Oogonium 30-37 n diam,
65. Oogonium 49-53 /* diam.

66. Membrane of oospore ribbed.

66. Membrane of oospore spinous.
67. Oogonium subdepressed-globose.
67. Oogonium subglobose to ellipsoid. 46.

68. Membrane of oospore smooth.

68. Membrane of oospore spinous.
69. Oogonium solitary.
69. Oogonia usually seriate.

70. Spines without order.

70. Spines arranged spirally.
71. Spines scanty ; oogonium subglobose.

61.
84.
62.
77-
63-
73-
64.
68.
52. Oe. Huntii.

65-
66.

43. Oe. Braunii.
44. Oe. flavescens.
82. Oe. illinoisense.
67.

45. Oe.pungens.
Oe. echinospermum.
69.
70.

47. Oe. irregulare.
59. Oe. multisporum.

48.

53.

72.

Oe. armigerum.

71. Spines dense ; oogonium depressed-globose. 49. Oe. echinatum.
72. Oogonium 51-64 /j. diam. ; veg. cells 15-35 n diam.

50. Oe. stellatum.
72. Oogonium 63-78 M diam. ; veg. cells 42-59 M diam.

51. Oe. Donne llii.
73. Pore median or slightly higher.

73. Pore superior.

74. Membrane of oospore smooth.

74. Membrane of oospore spinous.
75. Membrane of oospore smooth.
75. Membrane of oospore ribbed.
75. Membrane of oospore pitted.

76. Suffultory cell not swollen.

76. Suffultory cell swollen.
77. Oospore globose.
77. Oospore ellipsoid.

78. Division median.

78. Division superior.
79. Suffultory cell distinctly swollen.
79. Suffultory cell not swollen.

80. Terminal cell apiculate or setaceous.

80. Terminal cell obtuse.

74-
75-

Oe. sexangulare.
54. Oe. Hystrix.
76.

57. Or. Wollcanum.

58. Oe. concatenatum.

55. Oe. crassiusctdum.

56. Oe. Borisianum.

78.

82.

83. Oe. macrosporum.

79-

593. Oe. inonile.
80.

84. Oe. praticolum.
81.

62 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

81. Oogonium 36-45 M diani., usually seriate. 60. Of. macrandrium.
81. Oogonium 29-36 n diatn., single or 2. 85. Oe. propinqnmn.

82. Division superior; oogonium 14-23 M diam. 95.

82. Division apical ; oogonium over 30 M diam. 83.

83. Oogonium 33-56 M diatn. 62. Of. acrosporutn.

83. Oogonium 66-82 M diam. 86. Of. tentoriale.

84. Oogonium opening by a pore. 85.

84. Oogonium opening by a lid. 64. Of. undulatum.

85. Membrane of oospore smooth. 86.

85. Membrane of oospore ribbed. 63. Of. cyathigerum.

86. Oogonium 28 M diam. 87. Of. depressum.

86. Oogonium 55 60 M diam. 73. Oe. cataract urn.

87. Oospore globose. 88.

87. Oospore ellipsoid. 69. Of. pluvialf.

88. Division of oogonium median. 89.

88. Division of oogonium inferior. 68. Of. platygynum.

89. Oospore nearly or quite filling oogonium. 90.

89. Oospore not nearly filling oogonium 67. Oe. Areschougii.

90.. Oogonium 20-27 M diam. 65. Oe. Rothii.

90. Oogonium 30-38 M diam. 91.

91. Oospore depressed-globose. 66. Oe. decipiens.

91. Oospore globose. 74. Oe. londinenst.

92. Dioecious, oogonium 24-27 M diam. 3. Oe. Afagnusii,

92. Monoecious, oogonium 30-40 M diam. 90. Of. cytnatosporum.
93. Monoecious, vegetative cells 14 23 M diam. 13. Oe. foveolatuin.
93. Dioecious, vegetative cells, female, 24-48 « diam.

91. Oe. americanutn.

94. Oogonium 23-28 M diam. i. Oe. cryptoporuttt.

94. Ooogonium 32-38 M diam. 92. Oe. laeve.

95- Oogonium ovoid, larger below. 61. Oe. longatum.

95- Oogonium obovoid, larger above. 93. Oe. rugnlosutn.

Page 229, after description of OE. RUKESCENS, insert,

Var. EXIGUUM Him, 1900, p. 76, PI. I, fig. 5. Vegetative
cells more slender, oogonium single or 2, oospore subdepressed-
globose, antheridium 3-celled. 111., Transeau. Europe.

veg. cell, 5-9 M diam., 4-10 diam. long.

oog., 22-24 M " 20-28 Mlonj?.

00*., 20-22 M " 17-23 M "

anth. cell, 5 M " 10-12 M "

Page 233. before OR. PLAGIOSTOMUM var. GRACILIUS, insert,

OB. PLAGIOSTOMUM Wittrock ex Hirn, 1900, p. 100, PI. VI,
fig- 39-

THE GREEN ALGAE OF NORTH AMERICA 63

veg. cell, female', 23-27 /u diam., 3-4-5 diam. long,

veg. cell, male, 23-25 M " 2-3 "

oog., 43-49 /* " 46-57 M long.

oos., 41-47 fi " 42-49 M "

anth. cell," 22-24 M " 5-? /* "

Eastham, Mass., F. S. Collins. Europe.

The male plants of the typical form of Oe. plagiostomum were
observed for the first time in this material, and the dimensions
are taken therefrom. The other dimensions are copied from
Hirn ; the Eastham material showed slightly larger.

Page 237, after description of OE. PALUDOSUM var. AMERI-
CANUM, insert,

Var. PARVISPORUM Hirn, 1900, p. 120, PI. XIII, fig. 70.
Oospore smaller, not filling the oogonium, oogonium subellip-
soid or suboblong-ellipsoid, antheridium subepigynous. sub-
hypogynous or scattered.

veg. cell, 15-20 M diam., 3-6 diam. long,

oog.,' 38-44 M " 70-86 M long.

COS., 35-41 M " 54-60 A* "

anth. cell, 15-17 /* " 7-12 M "

111., Transeau. Europe.

Page 239, after description of OE. CRENULATUM forma CYLIN-
DRICUM, insert,

Var. LONGIARTICULATUM Hansgirg ex Hirn, 1900, p. 130,
PI. XV, fig. 86. Vegetative cells more slender, oogonia sub-
oblong-oboviform, single, oospore oboviform or nearly ellipsoid,
not quite filling the oogonium, lines on the membrane distinctly
crenate.

veg. cell, 12-15 M diam., 5-6 diam, long,

oog., 27-30 M " 57-60/1 long.

oos., 24-47 /u " 45-48 M "

Eastham, Mass., F. S. Collins. Europe.

Page 243, after note on OE. GRANDE var. AEQUATORIALE
f. HORTENSE, add,

Forma ROBUSTUM Hirn, 1900, p. 144.

veg. cell, female, 34-45 M diam., 2.5-6 diam. long.

veg. cell, male, 33-42 M " 2.5-6 " "

oog., 54-66 n. 78-90 /x long.

anth. cell, 30-36 M " 9-J5 M '

Middlesex Fells, Mass., A. B. Seymour; 111., Transeau.

64 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

According to Transeau this form is distinct and well marked
in Illinois, and seems to deserve varietal rank.
Page 245, after OE. CRISPUM, add,

Forma INFLATUM Him, 1900, p. 161, PI. XXV, fig. 140;
Transeau, 1917, p. 231. A slender form, with larger oogonia
and oospores.

veg. cell, 12-16 n diam., 3-6 diam. long.

oog., 40-50 M " 48-53 M

oos., 37-45 M " 38-45 M

anth. cell, 8-12 M " 9-12 M "

Mich., Transeau. l-.nrope.

Page 260, after the description of OE. CYATHIGERUM, add,

The typical form has been found in Ohio, Transeau.

Var. ELLIPTICUM Magnus & Wille ex Him, 1900, p. 255,
PI. XLIV, fig. 271.

Vegetative cells shorter, oogonium and oospore smaller ;
oospore often not quite filling the oogonium, of varying form,
quadrangular-ellipsoid or .nearly ellipsoid, rarely subglobose ;
oogonium single or 2 ; dwarf males on suffultory cell, more
rarely on oogonium.

veg. cell,

19-30 M diam.,

1.5-4 diam. long.

stiff, cell,

26-43 M "

1-5-3 " "

oog.,

50-63 M "

68-94 M "

oos.,

48-57 M "

48-65 M "

nan. cell,

15-18 u ••

43-55 M "

Ohio, Transeau.

South A.

Page 262, after OE. UNDULATUM forma SENEGALENSK add,
Var. AMERICANUM Transeau, 1917, p. 232. Vegetative cells

as in the typical form, oogonia and oospores larger.
oog., 58-68 M diam., 60-80 M long.

oos., 48-60 M " 48-56 M "

Trout Lake, Mich., Transeau.
Forma SENBGALBNSB, the only certainly American form be-

fore recorded, is about as much smaller than the typical form

in these dimensions as var. AMERICANUM is larger, but differs

in other respects.

Page 266, after description of OB. LONDINBNSB, add,

75. OB. INTERMEDIUM Wittrock ex Him, 1900, p. 94, PI. V,

THE GREEN ALGAE OF NORTH AMERICA 65

fig. 31. Monoecious, oogonium single, oboviform to oboviform-
globose, pore superior; oospore globose or obovi form-globose
(more rarely globose-oboviform) quite or nearly filling the
oogonium ; membrane smooth, usually thick ; antheridium 1-4-
celled, subepigynous or hypogynous, or rarely scattered ; sper-
matozoids binate, division horizontal.

veg. cell, 15-18 M diani., 3-4-5 diam. long,

oog., 31-37 n " 34-45 u long,

oos., 30-36 fj. " 33-41 M "

auth. cell, 14-16 /x " 5-io/x "

Charleston, 111. ; Utica, Ohio, Transeau. Europe.

Stouter than Oe. fragile, more slender than Oe. Vaucherii, in
both of which species the oospores are more definitely globose
than in Oe. intermedium.

76. OE. TYROLICUM Wittrock ex Him, 1900, p. 91, PI. IV,
fig. 25. Monoecious ; oogonium single, seldom 2, ellipsoid-
globose or sometimes obovoid, pore supramedian or nearly
superior ; oospore globose, rarely globose-ellipsoid, not quite
filling the oogonium ; membrane smooth ; antheridium 1-4-
celled, subepigynous or subhypogynous ; spermatozoids binate,
division horizontal.

veg. fil., 15-24 fj. diam., 3-5 diam. long,

oog., 45-53 M " 57-70 M long,

oos., 40-48 M " 40-48 /x "

anth. cell, 12-21 n " 9-1 IM "

Middlesex Fells, Mass., F. D. Lambert. Halle in Tyrol.

77. OE. ACMANDRIUM Elfving ex Him, 1900, p. 150, PI.
XXIII, fig. 120. Monoecious, oogonium single, rarely 2,
depressed-globose or subglobose, operculate, division median,
narrow ; oospore depressed-globose (or subglobose) filling or
nearly filling the oogonium, membrane smooth ; antheridium
i-3-celled, subepigynous, epigynous or hypogynous, often ter-
minal ; (?) spermatozoids single ; basal cell usually elongate.

veg. cell, 7-10 M diam., 3.5-7 diam. long,

oog., 30-35 M " 28-38 n long,

oos., 28-33 M " 25-29 n "

anth. cell, 8-10 M " 10-15*1 "

111., Transeau. Northern Europe.

78. OE. CONSOCIATUM Collins & Hervey, 1917, p. 36, PI. I.
figs. 1-4; P. B.-A., No. 2068. Dioecious ?, macrandrous ;
oogonium single, globose or depressed-globose, operculate,

66 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

division median or slightly superior, narrow ; oospore globose
or depressed-globose, filling the oogonium ; membrane smooth ;
vegetative cells more or less distinctly clavate ; basal cell
depressed-globose ; filaments often united in dense stellate
clusters.

veg. cell, 6-12 M ( -20 n) diani., 1-4 diain. long,

oog., 28 M diani., 26-28 M long,

oos., 26/1 " 24-26 M "

Bermuda, A. B. Hervey.

79. OE. PRATENSE Transeau, 1914, p. 297, PI. XXIX,
figs. 9-12. Dioecious, macrandrous, oogonium single, very rarely
2, subdepressed-globose or broadly pyriform-globose, opercu-
late, division median, narrow but distinct ; oospore depressed-
globose or subglobose, filling or nearly filling the oogonium,
membrane smooth ; male filaments more slender than female ;
antheridia i-2-celled, usually alternating with vegetative cells ;
spermatozoid single ; basal cell of filament commonly elongate.

veg. cell, female, 10-17 M diatn., 3-5-5-5 diam. long,

veg. cell, male, 8-15 M " 4-5-5 " "

oog., 33-40 M " 33-50 M long.

008., 32-38 M " 28-35 M "

anth. cell, 10-14 M " 13-18 M "

Charleston, 111., Transeau.

Somewhat resembling Of. acmandrium Elfv. and Of. psacg-
matosporum Nordst., but both these are monoecious, and of
smaller dimensions.

80. OE. PAUCO-COSTATUM Transeau, 1914, p. 300, PI.
XXVIII, fig. 5. Dioecious, macrandrous; oogonium singlf.
ellipsoid, operculate, division superior ; oospore ellipsoid, nearly
filling the oogonium ; outer membrane smooth, median longi-
tudinally ribbed, ribs 15-19, inner membrane smooth ; anthe-
ridium 2-8-celled ; spertnatozoids binate, division hori/ontal ;
terminal cell obtuse, basal cell usually elongate.

veg. cell, female, (15- ) 20-27 M diam., 3.5-5.5 diam. long,

veg. cell, male, (15- ) 10-25 M " 3.2-5.5 " "

oog., 54-60 M " 70-104 M long.

oo§., 50-56 M " 66-90 M "

anth. cell, 18-23 M " 8-12 M "

Casey, 111,, Transeau.

Resembling Of. australicum Him, but larger, spores more
distinctly ellipsoid, and with fewer ribs.

81. OB. OBLONGUM Wittrock ex Him, 1900, p. 185, PI.

THE GRBEN ALGAE OF NORTH AMERICA 67

XXIX, fig. 181. Monoecious, oogonium single, oblong, oper-
culate, division superior; oospore ellipsoid, filling the inflated
median or lower part of the oogonium ; membrane smooth ;
antheridium i-3-celled, subepigynous, subhypogynous or scat-
tered, spermatozoids binate, division horizontal.

veg. cell, 6-1 1 /tt diatn., 3-8 diam. long,

oog., 23-26/4 ' 41-50 AC long.

oos., 21-23 M " 30-33 M "

anth. cell, 6-9 /* " 7-9 y. "

Charleston, 111., Transeau. Europe.

In Oe. gradllimum the oogonium somewhat resembles that in
this species, but. the former is smaller in all parts.

82. OE. iivUNOiSENSE Transeau, 1914, p. 299, PI. XXI-X,
figs. 6-8. Dioecious, nannandrous, gynandrosporous ; oogonia
single, subglobose to oboviform-globose, pore median ; oospore
globose or subglobose, nearly filling the oogonium ; epispore
with 4-7 spiral ribs, uniting at poles, polar axis always trans-
verse to axis of the filament ; inner wall smooth ; suffultory cell
swollen; androsporangia i-5-celled ; basal cell elongate ; dwarf
males slightly curved, on suffultory cell ; antheridium exterior,
i-4-celled.

veg. cell, 13-18 /j. diam., 6-8 diam. long,

suff. cell, 32-40^4 " 1.5-2 " "

oog., 51-60 n " 60-70 /i long,

oos., 45-56 M " 48-66/14 "

andr. cell, 13-17 M " 17-22 /u "

nan. stipe, 14-17 M " 37-57 /* "

anth. cell, 9-r2 M " 15-23 M "

Lerna, 111., Transeau.

83. OE. MACROSPORUM W. & G. S. West ex Him, 1900, p.
227, PI. XXXVIII, fig. 232. Dioecious, nannandrous ; oogo-
gonium single, subdepressed-globose, operculate, division
median, very narrow ; oospore subdepressed-globose, filling the
oogonium, membrane smooth ; dwarf males curved, on the
suffultory cell ; antheridium exterior, i-?-celled.

veg. cell, !3-i3-5 M diam., 4-5 diam. long,

oog., 44-46 n " 39-40 M long,

nan., n-5 M " 38;* "

Utica, Ohio, Transeau. England.

The only nannandrous species with external antheridium and
median division of the oogonium.

68 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

84. OB. PRATICOLUM Transeau, 1914, p. 298, PI. XXIX.
figs. 1-5. Dioecious, (?) nannandrous, id ioandros porous ; oogo-
niutn single, more rarely 2-7, ellipsoid to globose-ellipsoid,
often terminal, sometimes scattered, wall sometimes rather
thick, operculate, division superior, near summit, lid very
small, deciduous; oospore ellipsoid to globose-ellipsoid, quite
filling the oogonium ; membrane smooth ; androsporangial fila-
ments a little smaller than female filaments ; androsporangium
i-zo-celled; vegetative cells slightly capitellate, basal cell usu-
ally elongate ; terminal cell apiculate or extended into a long
hyaline seta.

Teg. cell, female,

1 6- 26/1 diam.,

4-5 diam. long.

veg. cell, andr.,

14-22 M "

4-5 "

oog.,

48-60 M "

62-74 M long.

oos.,

46-58 M "

60-72 M "

andr. cell,

20-24 « "

18-22 M "

Charleston, 111., Transeau.

Related to Of. obtrnncatum Wittr., but somewhat larger,
idioandrosporous, and with different form of terminal cell.

85. OE. PKOPiNyuuM Wittrock ex Him, 1900, p. 236, PI.
XL, fig. 243. Dioecious, nannandrous ; oogonium single or 2,
oboviform-globose, operculate, division superior ; oospore glo-
bose, nearly filling the oogonium, membrane smooth; dwarf
males near or on oogonium, stipe curved ; antheridium exterior,
i-2-celled.

veg. cell, 10-13 M diam., 3-5 diam. long.

oog., 20-36 M " 35-45 M long.

00«., 24-31 M " 24-31 M "

nan. ttipe, II-IJM " 20-23 M "

antb. cell, 7-8 M " 6-8 M "

Charleston, III., Transeau. Europe.

Near Oe. macrandrium , Wittr., but the latter has larger
dimensions, and the oogonia are more generally seriate.

86. OB. TBNTORIALB Nordstedt & Him in Him, 1900, p.
248, PI. XLII, fig. 260. Dioecious, nannandrous; oogonium
single, terminal, short-ellipsoid or oboviform-glolx>se, opercu-
late. division superior, lid very small, deciduous ; inner surface
of membrane with longitudinal ribs, sometimes anastomosing ;
oospore completely filling oogonium, its membrane uniting with
that of the oogonium ; epispore longitudinally ribbed, with fine
striations between the ribs, about 40-45 ribs at the middle of the
oospore, ribs minutely crenulate ; endospore smooth ; suffultory

THE GREEN ALGAE OF NORTH AMERICA 69

cell usually swollen ; basal cell usually elongate, terminal

obtuse ; dwarf males nearly erect, on suffultory cell ; anthe-
ridium exterior, i-2-celled.

veg. cell, 20-33 M diam., 3-7 diam. long,

suff. cell, 25-37 /i " 3-5 " "

oog., 66-82 M " 73-88 M long,

nan. stipe, 10-14 u " 37-48 M "

anth. cell, 9-12 /i " 7 n "

Charleston, 111., Transeau. Brazil.

In many of its characters like Oe. acrosporum De Bary, but
larger throughout, with oogonia of more variable shape, usually
thicker in proportion to the length.

87. OE. DEPRESSUM Pringsheim ex Him, 1900, p. 249, PI.
XLJI, fig. 261. Dioecious, nannandrous, gynandrosporous ;
oogonium single, depressed-globose, pore median ; oospore
depressed-globose, not filling the oogonium ; androsporangium
2-celled ; dwarf males oblong-oboviform, on the oogonium ;
antheridium interior.

veg. cell, 8-9 /j. diam., 3-6 diam. long,

oog., 28 n " 26 n long,

oos., 23 /A " 17.5 M "

nan. cell, 4-5 M " 14-16 M "

Greenland, P. Richter. Germany.

88. OE. CRASSUM Wittrock ex Him, 1900, p. 139, PI.
XVIII, fig. 99. Dioecious, macrandrous ; oogonium single,
rarely 2, oboviform-ellipsoid, pore superior ; oospore ellipsoid
or globose-ellipsoid, not filling the oogonium, membrane
smooth ; male plants somewhat more slender than female ;
antheridium up to 2o-celled ; spermatozoids binate, division
vertical.

veg. cell, 40-49 /* diam., 2-4 diam. long,

oog., 68-75 fj. " 93-125 M long,

oos., 63-69 /* " . 75-i 10 /t "

Hanover, Ohio; New Buffalo, Mich., Transeau. Europe.

89. OE. REINSCHII Roy ex Hirn, 1900, p. 319, PI. L, fig.
326. Cells generally hexagonal in vertical section (widest at
the middle) occasionally subellipsoid or subcylindrical ; basal
cell not elongate, subhemispherical ; terminal cell obtuse.

veg. cell, 6-9 M ( -u) diam., 1.25-2.5 diam. long,

basal cell, 8-9 /* 5-6 M long.

Fla., Borge. Europe, South America.

70 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

No organs of fructification have been observed in this species,
though it is known from many stations.

90. OE. CYMATOSPORUM Wittrock & Nordstedt ex Him,
1900, p. 80, PI. II, fig. 13. Monoecious; oogonia single,
rarely two, subdepressed-globose, pore median or slightly
higher ; oospore depressed globose, filling or not quite filling
the oogonium, with triple membrane, median pitted, others
smooth; antheridia i-4-celled, subepigynous, subhypogynous,
hypogynous or scattered ; spermatozoid single.

veg. cell, 8-10 M diatn., 4-7 diani. long,

oog., (24- ) 30-40 M " 27-40 M long.

008., (22-) 27-35 M " (I9-) 22-33 Ji "

anth. cell, 7-10 M " 9-11 M "

With other species, Waverley, Mass., A. B. Seymour. Europe.
Nearly allied to Oe. Magnusii, but monoecious, with longer
cells, larger and more flattened oogonium and larger oospore.

91. OE. AMEKICANUM Transeau, 1917, p. 231. Dioecious,
macrandrous, oogonia single, globose to depressed globose,
pore superior ; oospore globose, ellipsoid-or depressed-globose,
partly or wholly filling the oogonium ; membrane triple, the
•median scrobiculate ; antheridia 1-5 celled, frequently alternat-
ing with vegetative cells ; spermatozoids binate, division hori-
zontal ; basal cell elongate, terminal cell obtuse.

veg. cell, female,

28-48 M diani.

1.5-3 diam. long.

veg. cell, male,

24-30 M "

1.5-4 "

oog.,

40-76 M "

48-70 M long.

COS.,

3»-74M "

46-56 M "

anth. cell.

20-28M "

4-12 M "

Charleston, 111. ; New Buffalo, Mich., Transeau.
Nearest to Of. foveolatum among our species, but dioecious
and of larger dimensions throughout ; the markings are on the
median, not the outer wall.

92. OE. LABVE Wittrock ex Him, 1900, p. 75 ; Transeau,
1917, p. 231. Monoecious, oogonia single, depressed-globose,
pore median ; oospore depressed-globose, filling the oogonium ;
antheridia i-2-celled, subepigynous; spermatozoid single,
veg. cell, 10-12 M diatn., 2-6 diam. long,

oog., 32-38 M " 28-30 M long.

oo«., 30-35 M " 23-26 M "

anth. cell, 9-10 M " 9-13 M "

Saugetuck, Mich., Transeau. Frana .

THE GREEN ALGAE OF NORTH AMERICA 71

93. OE. RUGULOSUM Nordstedt ex Him, 1900, p. 241, PI.
XL, fig. 249; Transeau, 1917, p. 231. Dioecious, nannan-
drous ; oogonia single or 2, oboviform or oboviform-ellipsoid,
very rarely oviform, operculate ; division superior ; oospore
ellipsoid, nearly filling the oogonium, rarely globose-ellipsoid
and then not filling the oogonium (membrane sometimes very
finely crenulate) suffultory cell not swollen ; dwarf males on
oogonium or near it ; antheridium exterior, i (-?)-celled, curved.

veg. cell, 4.5-8 n diam., 2.5-5 diam. long,

oog., 16-20 fj. " 22-29 /i long,

oos., 15-18^1 " 19-23 AC "

anth. cell, 4-6 /u " 5-6 /* "

nan. cell, 5-7 n " 11-14/1 "

New Buffalo, Mich., Transeau. Europe.

Page 275, after account of BULBOCHAETE minor, add,

OEDOCLADIUM Stahl ex Hirn, 1900, p. 374.
Terrestrial, branching, partly subterranean and subhyaline,
partly above ground and green ; vegetative cells cylindrical,
growth chiefly by division of terminal cell of a filament or of a
branch ; oogonia arising by simple division of a vegetative cell.
O. albemarlense I. F. Lewis in litt. Monoicum, oogoniis
singulis, plerumque terminalibus, subglobosis, apice conica,
poro inferiore apertis, membrana levi, oosporis globosis, oogo-
nium non complentibus, episporio levi, mesosporio scrobiculato
(in sectione optica undulato) endosporio levi ; antheridiis ad
9-cellularibus ; cellulis vegetativis subcylindricis, cellula ter-
minali apice conica.

Monoecious, oogonia single, mostly terminal, subglobose with
conical apex, pore inferior, membrane smooth ; oospore globose,
not filling the oogonium; epispore smooth, mesospore scrobicu-
late (in optical section undulate) endospore smooth ; antheridia
to 9-celled ; vegetative cells subcylindrical, terminal cell with
conical apex. Fig. 22.

On sandy loam, bank of the Rivanna above the woolen mill
near Charlottesville, Albemarle County, Virginia, Oct. -Dec.,
1916, I. F. Lewis. Type deposited in the herbarium of the
Cryptogamic Laboratory, Harvard Univeraity.

veg. cell, superterranean, 25-40 n diam., 50-150 /* long,
veg. cell, subterranean, n M " -35°^ '

oog., 90 M " 95 M "

oos., 69 M " 69 M '

anth. cell, 20-15 M " 8-19 M "

72 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

The only other known species, O. protonema Stahl ex Him,
1900, p. 374, PI. LIV, fig. 396, was found on moist earth near
Strasbourg in 1877, but does not appear to have been found
elsewhere. O. albcmarlensc is larger throughout, the upper
part of O. protonema being only about 7 /* diam., and is also
distinguished by the scrobiculate mesospore and the inferior
pore. Like O. protonema it is found in company with Botry-
Jium, Vaucheria, Riccia, etc.

Page 279, for Key to the Species of Endoderma, substitute,

I. Kndophytic, marine. 2.

I. Epiphytic, fresh water. 5.

2. ID leaves of /ostera. 3. E. pfrforans.

2. In marine algae. 3.

3. Cellt mostly irregular. 2. E. viride.

3. Cells mostly cylindrical. 4.

4. Cells 5- 10 M diam. I. E. Wittrockii.

4. Cells 2-6 M diam. 6. E. Jilifortne.

5. Cells sobglobose to ellipsoid. 4. E. Pithophorae.

5. Cells much flattened. 5. E. polytnorphum.

Page 280, after description of E. POLYMORPHUM, add,
6. E. HILIPORMK Collins & Hervey, 1917, p. 39. Filaments
branched laterally and dichotomously ; cells cylindrical, 6 ft
diam. below, tapering to 2 /A near apex : sporangia formed from
any cell of the older part, depressed hemispherical, 6-12 ft diam. ;
bristles continuous with the cell, 4 p. diam. at base, tapering to
2 /*. In wall of Lyngbya conferuoidts Ag., Bermuda, Collins.

Page 281, change generic character of CHAETOSPHAERIDIUM
in first three lines as follows : —

Cells globose, ovoid or hemispherical, with one or more disk-
shaped chromatophores, each with one pyrenoid.

For Key to the Species of Chaetosphaeridium, substitute,

i. Utricles evanescent ; general gelatinous coating conspicuous.

I. C. globosum.
I. Utricles well develeped ; gelatinous coating inconspicuous. 2.

2. Cells globose, chromatophore single. 2. C. Pringsfieimii.

2. CelU ovoid, chromatophores two. 3. C. ovalis.

After description of C. PRINGSHEIMII, add,

Forma CONPBRTA Klebahn, 1893, P- 3<>7. PI- XIV, fig. n.
Cells closely compacted, often seeming to form a layer ; utricles
very short. Wis., G. M. Smith. Europe.

THE GREEN ALGAE OF NORTH AMERICA 73

3. C. OVALE G. M. Smith, 1916, p. 471, PI. XXIV, fig. i.
Thallus of 5-20 cells, epiphytic on filamentous Chlorophyceae ;
gelatinous sheath indistinct ; cells ovoid, with 2 parietal chro-
matophores each containing a pyrenoid ; sheath at base of setae
conspicuous. Cells 20-22 X 13-15 p- ', setae about 125/1; basal
sheath 3-5 p. Wis., G. M. Smith.

Page 282, after description of ACROCHAETE PARASITICA, add,

CHABTONEMA Nowakowski, 1877, p. 75.
Frond filiform, branching, bearing long, inarticulate bristles
with somewhat swollen bases ; cell division intercalary and
terminal ; chromatophore disk-shape, parietal, with i or more
pyrenoids. Asexual reproduction by zoospores formed 2 ill a
cell, with 4 cilia and contractile vacuole, without stigma.

Only one species.

C. iRREGuivARE Nowakowski, 1877, p. 75 ; Huber, 1892, p.
302, PI. XII ; P. B.-A., No. 2137. Cells 9-15 ft diam., 2-4 diam.
long ; bristles 4-5 /* diam. at base. In gelatinous coating of
Batrachospermum, Tetraspora, etc. Fig. 20. Mass. Europe,

PHAEOPHILA Hauck, 1876, p. 57.

Articulate filaments epi- or endophytic, each cell bearing 1-3
long, inarticulate hairs, continuous with the cell, and not
dilated at the base. Reproduction by zoospores.

P. FLORIDEARUM Hauck, 1876, p. 57; 1885, p. 464, fig. 2OO.

In various loose-tissued algae ; cells of irregular form, 12-40 /i

diam. Fig. 23. Bermuda. Europe.

Page 288, after the description of genus PRINGSHEIMIA, add,

KEY TO THE SPECIES OF PRINGSHEIMIA.

i. Median cells usually taller than their diam. ; cells not showing dis-
tinct radial or zonate arrangement. i. P. sen fata.

i. All vegetative cells broader than high; radial and zonate arrange-
ment of cells distinct. 2. P. Udotae.

After description of P. SCUTATA, add,

2. P. (?) UDOTAE Borgesen, 1913, p. n, fig. 3. Vegetative
cells mostly elongate towards the margin, 17-70 \i. long, average
40 p. ; 5-25 n wide, average 16 /* ; 10-12 p. thick ; except in center
of frond in distinct dichotomous radiating series, and often
showing concentric arrangement ; sporangia formed in central
part of the disk, which elongates vertically ; zoospores dis-
charged through a neck-like papilla. On Udotea Flabellum,
Virgin Islands, Borgesen, who places it in this genus with
some doubt.

74 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

Page 290, after generic account of GONGROSIRA, add,

KEY TO THE SPECIES OF GONGROSIRA.

I. Cells 6-14 M diam. ; branches of basal layer often penetrating sub-
stratum. I. G. /atus/n*.
i. Cells 15-30 M diam. ; no descending branches from basal layer.

2. G. Debaryana.

i. G. LACUSTRIS Brand, 1907, p. 502; Trauseau, 1917, p.
230. Fronds small, nearly flat, later confluent, dull green ;
base of procumbent filaments 6-14 p diam., usually about n /*,
erect branches of about the same size, short, little branched ;
cells varying, some short and with rich contents, of irregular
form, some longer, cylindrical and nearly empty. Reproduc-
tion by akinetes, and probably also by zoospores. Growing on
decaying wood and on stones ; in the former case the prostrate
filaments may send down branches penetrating the substratum.
Mich., Transeau.

Page 294, for Key to the species of Microthanmion, substitute,

i. Filaments 1-2.6 M diam. ; little branched. 3. M.exiguuin.

i. Filaments 2.5-4 M diam. ; much branched, 2.

2. Ramiiicaiiou dense; main stem and branches indistinguishable.

i. M. Kuetzingianum.
2. Ramification open ; main stem distinguishable.

2. M, strictissimtim.

Page 295, after M. STRICTISSIMUM var. MACROCYSTIS, add,

M. sxir.uuM Reinsch, 1877, p. 245; Transeau, 1917, p. 230.
Filaments 1. 1-2. 6 /* diam., sparingly branched, branches erect,
with few or noramuli, apices slightly clavate. Mich., Transeau.

/ ';/, ,/

Much smaller than our other species.

Page 297 and p. 90 of supplement, for Key to the Species of
Stigeocloniuni. substitute,
i. Erect filaments unbranched except at the extreme bate.

S. subsimple.i-.
i. Brect filaments more or less densely branched throughout. a.

2. Opposite branching predominant. 3.

a. Alternate branching predominant. 9.

3. Main filaments medium, or leas. 6. 5. tenuf.

3. Main filaments 1 1-30 M diam. 4.

4. Lower cells much inflated. 5. S. ventricosum.

4' Lower cells slightly or not inflated. 5.

5. Lower cells not over 2 diam. long. 6.

5. Lower cells 2-8 diam. long. 7.

THE GREEN ALGAE OF NORTH AMERICA 75

6. Lower cells seldom as long as broad ; ratnuli tapering, thorn-like.

4. S. subuligerum.
6. Lower cells usually longer than broad ; ramuli short-pointed.

i. 5". lubricum.

7. Lower cells 2-5 diam. long. i. S. lubricum var. varium.

7. Lower cells 3-8 diam. long. 8.

8. Ramuli pointed. 2. s. amoenum.

8. Ramuli setiform. 3. S. flag ellifer urn.

9. Filaments short, tufted. Ia

9. Filaments more elongate. ™

10. Of thermal waters. 7. s. thcrmale.

10. Of ordinary temperatures. JIm

ii. Tips obtuse or short-pointed. 8. S. nanum.

ii. Tips attenuate or setiferous. 12.

12. Ramuli scattered.

'3-

12. Ramuli densely fasciculate. 10. S. glomeratum.

13. Main filaments 7-9 //. diam. 9. S. aestivale.

13. Main filaments 4-6 /j. diam. 14. S. minus.

14. Floating. I2. 5. stagnatile.

14. Attached. I^<

15. Main filaments 10 M diam. or less. 16.

15. Main filaments 10 /* diam. or more. 17.

16. Cells of main filaments 6-10 M diam., usually 4-6 diam. long, some-
times 12 diam. 5. longearticulatum.
16. Cells of main filaments 5^7 p. diam., 2-5 diam. loug.

5*. attenuatum.
17. Filaments 10-12 /u, diam., cells except in the main axis seldom over

i diam. long. 2. 5". amoenum forma biforme.

17. Filaments 12-18 M diam. 18.

18. Main filaments with cells 1-2 diam. long, moniliforni.

5". autumnale.
18. Main filaments with cells 3-10 diam. long, cylindrical.

13. S. subsecundum.
Page 302, after description of S. MINUS, add,

S. LONGEARTICULATUM (Hansg.) Heering in Pascher, 1914,
p. 71, fig. 95; S. falklandicum var. longearticulatum Hansgirg,
1886, p. 65, fig. 27; S. falklandicum Wittr. & Nordst., Alg.
Exsicc., No. no. Main filaments 6-10 /x diam., cells 4-6, occa-
sionally 12 diam. long, cylindrical ; branching sparingly below,
freely above ; branches somewhat narrower and with relatively
shorter cells ; chromatophore a narrow band at the middle of
cell. Utica, Ohio, Transeau. Europe.

Page 305. Add, Lemmermann in Pascher, 1915, p. 47, trans-
fers CHLOROSPHAERA LACUSTRIS Snow and C. PARVULA Snow
to the following genus of Tetrasporales.

76 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

CHLOROSARCINA Gerneck, 1907, p. 221.

Cells solitary or united in colonies, with or without gelatinous
coating ; chromatophore parietal, with or without pyrenoid ;
product starch and oil ; asexual reproduction by division in 2-3
directions and by biciliate zoospores.

KKY TO THE SPKCIKS OF CHI.OROSARCINA.

i. Cell* without gelatinous coating. i. C. lacustris.

i. Cells with gelatinous coating. 2. C.f>arrnl<i.

1. C. LACUSTRIS (Snow) Lemmermanu in Pascher, 1915, p.
48; Chlorosphacra lacustris Snow, 1903, p, 386, PI. IV, fig. 14.
Cells spherical, ovoid or somewhat angular, 9-10.5 p. diain.,
forming dense, at first flat, later spherical free colonies without
gelatinous coating ; pyrenoid present ; zoospores 4 in a cell,
narrowly ovoid, 6.5-9 X 2.6-4 /*, with stigma. Fig. 24. Lake
Erie, Snow.

2. C. PARVULA (Snow) Lemmermann in Pascher, 1915, p.
48; CMorosfihaera parvula Snow, 1903, p. 386, PI. IV, fig. 15.
Cells spherical or ovoid, 7.8-9 /* diain., wall thin ; 4-8 united into
a flat, free gelatinous family ; pyrenoid present ; zoospores 4-8
in a cell, broadly ovoid or spherical, 5-6 /* diam., with stigma.
Lake Erie, Snow.

The value of this genus, and the inclusion in it of these two
species, are very uncertain matters. The paper by Gerneck, in
which the genus is proposed, though undoubtedly representing
careful study, from a systematic point of view holds the record
for being everything that such a paper should not be. Leinnu i
maun transferred to the genus these two American species \\itli-
out having seen them, alive or dead.

Page 309, after the description of GLOEOCYSTIS SCOPULORUM,
add,

GLOHOCYSTOPSIS G. M . Smith, 1916, p. 474.

Cells elongate-cylindrical, more or less curved, with rounded
ends, aggregated by 4 or 8 within a non-lamellated, sharply
defined, spherical, gelatinous sheath. Colonies of an indefinite
number of these aggregates arranged in a spherical or ovoid
mass ; chromatophore parietal, with one pyrenoid, later becom-
ing diffuse ; reproduction, aside from cell division, unknown.
Only species.

G. LIMNBTICUS G. M. Smith, 1916, p. 475, PI. XXIV, fig. 12.
Cells 10-15 X 4-6 ft. aggregates 25-30/1 diam. ; colonies up to
i25Mdiam. Fig. 25. Wis., G. M. Smith ; Mass., F. D. Lambert.

THE GREEN AI.GAE OF NORTH AMERICA 77 .

COCCOMYXA Schmidle, 1901, p. 20.

Cells enclosed in a general gelatinous mass, homogeneous or
sometimes showing slight stratification around the cells. Cells '
usually elongate, with lateral, parietal chromatophore without
pyrenoid ; asexual reproduction by autospores, 4 in a cell.
Only one American species recorded.

C. DISPAR Schmidle, 1901, p. 23, PI. I, figs. 6-25. Gelati-
nous mass attached, not floating, usually small but sometimes up
to several cm. diam. Cells ellipsoid, more or less unsymmetri-
cal, 4-8 /A diam., 2-2.5 diam. long. In moist places, on wood,
moss, etc. Fig. 26. Chocorua, N. H., W. G. Farlow. Europe.

Common mode of reproduction by an oblique wall, but this
may be merely incomplete autospore formation.

Page 311, for Key to the Species of Herposteiron, substitute,

i. Cells usually subglobose, 5-15 M diam. 2.

i. Cells usually elongate, 4-6 fj. diam. 2. H. vermiculoides.

2. Cells 5-10 fj. diam., each usually with one seta. i. H. confervicola.

2. Cells 9-12 judiam., each usually with several setae.

3. H. polychaete.

Page 312, after description of H. VERMICULOIDES, add,

3. H. POLYCHAETE Hansgirg, i888b, p. 214, PI. XIV, figs.

1-5. Cells subspherical, 9-12/1 diam., each bearing 2-6 setae

with sharply bulbous base, and tapering gradually to a very fine

point. Wis., G. M. Smith. Europe.

Page 315, after paragraph on COLEOCHAETE, add,
C. DECORANS Richter, 1897, p. 9. fig. 4, and C. IKERASA-
CENSIS Richter, 1897, p. 10, fig. 5, are described as growing on
Oedogonium from Greenland. No reproduction of any kind is
known, and habit characters are not such as to make certain
that they belong to this genus.

Page 323, for Key to the Species of Chaetomorpha, substitute,

i. Filaments 400 /* diam. or more.

i. Filaments less than 400 M diam. 6.

2. Filaments increasing noticeably in diam. from the base up.

i. C. clavata.

2. Filaments of nearly uniform diam. .except at the extreme base. 3.
3. Basal cell several times longer than any other cell. 3. C. media.
3. Basal cell not markedly longer than the others. 4.

4. Filaments more or less moniliform, usually closely curled.

i A. C. tort a.

4. Filaments not distinctly moniliform nor regularly curled. 5.

78 TUPTS COLLEGE STUDIES, VOL. IV, No. 7

5. Boreal plant, dark and stiff. 2. C. mtlagonium.

5. More southern plant ; not dark nor stiff. 9. C. crassa.

6. Filaments 40 ^ diam. or more. 7.

6. Filaments not over 40 M diam. 10.

7. Filaments not over 70 M diam. 10. C. gracilis.

7. Filaments 80 M diam. or more. 8.

8. Cells 3-8 diam. long. 6. C cannabina.

8. Cells not over 2 diam. long. 9.

9. Filaments 200-250 M diam., rarely to 125 or 400 M; yellowish green.

4. C. f. in inn.
9. Filaments 125-175 M diam., dark green ; southern plant.

5. C. brachygona.

10. Freshwater; filaments attached by pluricellular rhizoids.

.8. C. chtlonum.

10. Marine; attached by a disk. u.

ii. Saxicolons; 20-40 M diam. 7. C. calif ornica.

n. Epiphytic; 10-20 /i diatn. 11. C. minima.

Page 323, for C. CLAVATA, substitute,

i. C. CLAVATA (Ag.) Kiitzing, 1847, p. 166; Vickers, 1908,
p. 17, PI. VII ; not P. B.-A., No. 371 ; Conferva clavata Agardh,
1824, p. 99. Filaments attached, erect, stiff, up to 60 cm. long,
base about 500 /* diam., gradually increasing to 1.5 mm. at the
tip; lower articulations 3-4 diam. long, those of the upper part
about as long as broad, more or less moniliform, color deep
green. Fla., W. I.

lA. C. TORTA (Farlow) Yendo, 1914, p. 264, excl. syn. ;
C. clavata var. torla Farlow in Collins, 1909, p. 323 ; Alg. Am.-
Bor. Exsicc., No. 211 ; P. B.-A., No. 571 ; C. clavata P. B.-A.,
No. 371. Found only unattached ; filaments of nearly uniform
diameter throughout, little or not at all moniliform, 400-600 JA
diam., cells 1-2 diam. long, filaments usually coiled in a spiral,
often very close. Cal. Japan.

Yendo is probably right in separating this from C. clavata,
but hardly in including under it C. spiralis Okamura, dis-
tributed in Okamura, Alg. Jap. Exsicc., No. 94, ^903, with
description, and figured in Icones Jap. Algae, Vol. II, PI. XCV,
which seems quite distinct. Certainly nothing like it has been
recorded in California. Yendo has C. torla (Farlow) McClatchie,
and the binominal occurs in McClatchie, 1897, p. 351, but with-
out citation or description. Though distributed as C. clavata var.
/or/a in 1889, no description was published till 1909, and in case
it should prove that Okamura's plant is the same, his name has

THE GREEN ALGAE OF NORTH AMERICA 79

priority . C. spiralis, however, seems nearer allied to C. Darwinii
(Hook.) Kiitz., which also has the upper cells subspherical, or
depressed-spherical, but C. spiralis is in all probability distinct
from the latter. It may be a question, however, if it is distinct
from C. moniligera Kjellman, iSgyb, p. 24, PI. IV, figs. 17-23,
also from Japan.

Page 324, for C. ANTENNINA, substitute,

C. MEDIA (Ag.) Kiitzing, 1849^.380; C. antennina Vick-
ers, 1908, p. 19, PI. VIII; Collins, 1909, p. 324; Borgesen,
I9I3» P- l(>, figs. 4-5 ; Wittr. and Nordst., Alg. Exsicc., No.
1439 ; not Conferva antennina Bory ; Conferva media Agardh,
1824, p. TOO. Filaments deep or dark green, attached in dense
tufts, stiff and firm, up to 40 cm. high ; basal cell elongate, in-
creasing from 100-150 p. diam. at base to 300-400/1 at summit,
2-8 mm. long,, other cells 400-500 p diam., 2-6, mostly 3-4 diam.
long. W. I. Brazil.

In the West India region this species corresponds to the at-
tached forms of C. Linum of the Atlantic coast from Massachu-
setts south, and of C. melagonium from Massachusetts north.
The cells are longer than in either of the two last species, and
the basal cell is more specialized. It has generally passed
under the name of C. antennina, but Howe, 1914, p. 37, states
from his examination of the type of the latter that it has a longer
basal cell, with a diameter at the top of 500-580 /u., and the other
cells are usually only 270-400 p. diam., and ^3-1^ diam. long.
C. antennina appears to be limited to the Pacific Ocean ; the
reference to Africa, Collins, 1909, p. 324, being an error.

Page 325, after description of forma LINUM, add,

CONFERVA LINUM Flora Dauica, Vol. V, p. 4, PI. DCCLXXI,
1782, appears to be the oldest name; therefore what we have
considered as a form, and which is a form from the biological
point of view, must stand as C. LINUM (Fl. Dan.) Kiitzing,
1845, p. 204, while the attached form becomes forma AEREA
(Dillw.) ..

Page 326, after description of C. CHELONUM, add,

9. C. CRASSA (Ag.) Kiitzing, 1845, p. 204; 1853, p. 19, Pi.
LIX, fig. II; P. B.-A., No. 1864; Borgesen, 1913, p. 18 ;
Conferva crassa Agardh, 1824, p. 99. Filaments 500-550 p.
diam., cells usually about as long as broad, occasionally up to
2 diam., wall thick. In loose masses in shallow water, W. I.,
Bermuda. Europe.

8o TUFTS COLLKGB STUDIES, VOL. IV, No. 7

10. C. GRACIUS Kutzing, 1845, p. 203; 1853, p. 17, PI.
LII, fig. I; Borgesen, 1913, p. 19. Filaments 40-70/4 diam.,
cells 2-4 diam. long. Loosely floating, W. I., Bermuda.

Europe; Singapore.

11. C. MINIMA Collins & Hervey, 1917,?. 41, PI. I, figs. 5-7 ;
P. B.-A., No. 2007. Filaments cylindrical or slightly clavate,
short, 10-20 /* diam., cells 2-4 diam. long ; membrane relatively
thick and lamellate ; on larger algae. Bermuda.

Page 330, under RHIZOCLONIUM CRASSIPELI.ITUM, note,

The typical form has been found at Bermuda, and distributed
as P. B.-A., No. 2008; also at Holland, Mich., Transeau.

Page 332, in Key to the marine species of Cladophora, make
changes and additions as follows :
For Nos. 1-5,

I. Low, pulvinate or matted, with main filaments more or less pros-
trate. 2.
i. Erect. 6.
2. Lower part of filament! 300-350 n diam. 41. < '. mteite \ta.
2. Lower part of filaments less than 300 M diam. 3.
3. Branching mostly irregular, not dichotomons. 4.
3. Branching mostly di-trichotomous. 5a.
4. Erect branches distinct from prostrate filaments and smaller. 5.
4. No sharp distinction between different kinds of filaments.

37. C. Magdalenae.
5. Basal filments 150 M diam.; erect filament* 20-50 M diam., cells 5-20

iliatn. long. 38. C. ffowei.

5. Basal filaments 40-100 M diam. ; erect filaments 30-50 n diam., cells

4-8 diam. long. 40. C. amphibia.

5a. Cells cylindrical or nearly so ; color dark. 58. C. repens.

5*. Cells of ramnli ovoid or pyriform. 5b.

Sb. Cells 120-250 M diam. 39. C. trichotoma.

50. Cells 60-100 M diam. 59. C.frascatii.

For No 10,

10. Cells with more or less regular constrictions: IOA.

10. Cells without regular constrictions. 20.

loa. A single constriction near base of cell. la. C. constricta.

ioa. Frequent constrictions of cells of main axes; ramuli often hooked

or circinate. 54. C. uncinata.

For No. 30.
30. Branches often decumbent ; rbizoidal branches numerous.

55. C. corallicola.
30. Not decumbent ; rhizoids few or none. 30*.

THE GREEN ALGAE OF NORTH AMERICA 81

3oa. Articulations long, up to 20 diatn. 3. C. Rudolphiana.

3oa. Articulations not over 8 diam. long. 31.

For No. 45.

45. Forming a dense hemispherical tuft, with or without slender loose
tufts arising from it. 60. (7. hemisphaerica.

45. No dense hemispherical tuft. 458.

45a. Substance soft and silky; cells 4-12 diam. long; ramuli erect.

45b.
45a. Substance crisp or harsh; cells 1-5 diam. long; ramuli patent.

45C-

45b. Branching continuously dichotomous, except as to ultimate ramuli.

9. C. Stimpsoni.
45b. Main branching dichotomous ; lesser branches and ramuli dense,

largely secund. 19. C. crystallina.

45c. Crisp but not. harsh ; cells 3-5 diam. long ; ramuli scattered and

distant. 56. C. piscinae.

45C. Stiff and harsh ; cells mostly 1-2 diam. long ; ramuli closer, often
in secund series. 57. C. rigidula.

Page 335, in Key to the Fresh Water species, for Nos. 5 and
6, substitute,

5. Main filaments long, with few branches. 5a.

5. Filaments freely branching. 6.
5a. Strongly moniliform ; cells averaging little over i diam. long.

62. C. moniliformis.
5a. Cells slightly swollen, 4-6 diam. long. 51. C. insignis.

6. Ramuli mostly unicellular. 48. C. oligoclona.
6. Ramuli pluricellular, long-celled. 6a.

6a. Branching irregular ; branch-bearing cells appearing forked at sum-
mit; growing at bottom of cold, deep lakes. 61. C. profunda.

6a. Branching alternate, usually dense ; branch-bearing cells normal ;
plant of shallow water. 49. C. crispala.

Page 337, after first paragraph, add,

C. RUDOLPHIANA forma eramosa N. L/. Gardner forma
nova. Ramis praelongis, subsimplicibus.

Branches very long, subsimple. In warm salt water pool,
Key Route Power House, Oakland, Cal., April, 1915. Type
in herb. N. L. Gardner, No. 2856.

Apparently a result of the abnormal, uniformly high tem-
perature.

Page 349, after C. TRICHOTOMA, add,

Var. ELONGATA Collins in P. B.-A., No. 2141. Growing in
deeper water, up to 3 dm. long, little branched below, freely

82 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

branched near the surface of the water. Point Lobos, Cal.,
N. L. Gardner.

A form of deep quiet pools, little affected by the tide : very
different in appearance from the loose matted typical form, but
without technical characters sufficient for specific separation.

Page 356, after SPONGOPSIS SACCATA, add,

54. C. UNCINATA Borgesen, 1913, p. 20, figs. 9 and 10.
Densely tufted, 4-5 cm. high ; attached by branching rhizoids ;
main filaments no p. diam., cells 10-15 diam. long, with thick
wall and frequent annular constrictions; branches 65 n diam.,
without constrictions, cells 4-6 diam. long, di-trichotomously
branched, with scattered or secund ramuli, 35 p diam., often
hooked or circinate ; color dark green. Virgin Islands.

Amply distinct by constricted axes and' strongly hooked
ramuli.

55. C. CORALLICOLA Borgesen, 1913, p. 21, figs. 11-12;
P. B.-A., No. 2010. Densely tufted, decumbent filaments at-
taching to the substratum and emitting erect branches ; main fila-
ments 125-150 n diam., cells 5-10 diam. long, cells in secondary-
branches and ramuli 70 ft diam., 5-6 diam. long. Branching
di-trichotomous below, few branches above, branches more or
less curved or sinuous ; cells more or less clavate ; rhizoids
abundant, 45 M diam. Bermuda, Virgin Islands.

56. C. PISCINAE Collins & Hervey, 1917, p. 46; P. B.-A.,
No. 2165. Main filaments roo/tdiam.; ultimate ramuli 50 /* ;
cells 3-5 diam. long, nodes not constricted ; terminal cell rounded
or truncate ; branching by wide, equal, distant forkings, with
distant, patent ramuli above ; color light green ; substance
somewhat crisp but not fragile. Bermuda.

In still water of a fish pool, forming large, loose masses, in
appearance like some of the larger species of Spirogyra.

57. C. RIGIDULA Collins & Hervey, 1917, p. 47. Main fila-
ments 120 /* diam., secondary 100 /*. ultimate cells 80 ft ; cells
1-2 diam. long, nodes not constricted ; terminal cell usually
longer, sometimes 3 diam., rounded or subacute ; branching at
base by broad forkings, at first frequent, then distant ; branches
in upper half of frond long, straight, with ramuli nearly or
quite at right angles, distant and scattered below, near the tips
in secund series ; color rather dull light green ; substance firm
and harsh. Bermuda.

Iti some respects like the preceding species, but coarser and

THE GREEN ALGAE OP NORTH AMERICA 83

stiffer, and with shorter cells, with lesser differences as above
noted.

58. C. REPENS (J. Ag.) Harvey, 1846-51, PI. CCXXXVI ;
P. B.-A-, No. 2071 ; Conjerva repens]. G. Agardh, 1842, p. 13.
Filaments 100-150 p. diam., loosely dichotomous, not tapering to
apices ; cells below 2-3 diam. long, above 6-8, rarely 10 diam.
Color dull, dark green ; forming dense pulvinate spongy masses
at low water mark and between tides. Bermuda. Mediterranean.

A coarse, matted, unattractive plant.

59. C. FRASCATII Collins & Hervey, 1917, p. 49; P. B.-A.,
No. 2164. L,ow, 1-2 cm. high, branching irregular, below
mostly dichotomous, with wide forkings ; above partly similar,
partly lateral, patent, often at a right angle ; ultimate ramuli
i-3-celled, nearly or quite at right angles, often secund on the
outer side of a recurved branch. Cells below 70-100 p. diam.,
2-5 diam. long, cylindrical; in the ramuli 60-80 p. diam., 2-3
diam. long, somewhat swollen with constricted nodes; terminal
cell obtuse. Bermuda.

Growing in similar places to C. repens, and forming similar
matted tufts, but distinct by the smaller dimensions and the
lateral, secund, submoniliform ramuli.

60. C. hemisphaerica N. L. Gardner, sp. nov. Frons parva,
compacta, hemisphaerica, radii ad i cm. ; ramificatione dicho-
toma, densa ; dichotomiis angustis; cellulis 60-150 p. diam., 3-6
diam. longis, saepe manifeste clavatis ; postea minus regulariter
hemisphaerica, ad 3 cm. alta, ramis distantioribus, superiorum
cellulis 50-80 p. diam., cylindricis. Aliquando e fronde hemi-
sphaerica exsurgunt fasciculi longi, tenues, cellulis cylindricis,
50-80 p. diam., dichotomiis longe distantibus, perangustis.
Substantia chartacea, minus adhaerente.

Frond at first compact, hemisphaerical, of not over i cm.
radius, branching at base dichotomous, dense, forkings narrow,
cells 60-150/1 diam., 3-6 diam. long, often distinctly clavate ;
later less regularly hemispherical, up to 3 cm. radius, branches
more distant, with cells in the upper part 50-80 p. diam., cylin-
drical. Sometimes there arise from the hemispherical frond
long, slender tufts, with cylindrical cells, 50-80 p. diam., fork-
ings very distant and narrow. Substance firm, not adhering
well to paper.

On rocks and in pools, middle and upper literal zone, Monte-
rey County, California. Type No. 3359 in herb. N. L. Gard-
ner, from Cypress Point, June, 1916.

84 TUFTS COU.BGB STUDIES, VOL. IV, No. 7

The hemispherical tuft appears to be a single individual, and
to be the normal form of the species. When growing in warm
high pools, a long floating tuft is sometimes developed, arising
from the otherwise unchanged normal frond. There is no
species of this region with which it is nearly allied ; the habit
somewhat suggests a worn frond of some small species of Spon-
gomorpha, but the resemblance is only in habit.

61. C. PROFUNDA var. NORDSTEDTIANA Brand, 1902, p. 64.
Forming fine, loose, subradiate masses, branching erecto-patent,
often secund ; branches arising below the summit of a cell, the
first cross wall usually slightly above the origin of the branch :
main filaments 40-68 p. diain.. ramuli 23-35 /*; cells usually
8-30 diam. long, in lower part of frond occasionally only 4-8
diam. On limestone bottom of Lake Ontario, at 50 m. depth.
E. M. Kindle.

The typical C. profnnda occurs in European lakes at a depth
of 10-15 m., and has filaments up to 85 \<- diam. ; the distance
from the point of origin of a branch to the summit of the cell
bearing it is about the same as to the first cross wall in the
branch, and the appearance is that of a forked cell, each fork
bearing another cell ; this appearance is less marked in var.
Nordstfdtiana . In the letter of Dr. Brand, identifying the
Ontario specimen submitted to him, he proposes to call it
"forma into, " but gives no characters. See Kindle, 1915,
P- 654. .

62. C. moniliformis sp. nov. Fronde parce ramosa, inferne
dichotoma, ramis divergentibus, cellulis infimis ramorum vnl.u<>
adhaerentibus dimidio longitudinis, ramulis paucis, minorilms .
cellulis ramorum ^4-2 diam. longis/plerunujue diametrum paullo
superantibus, medio perinflatis, usque ad 145 /', dissepimento
solum 75-80 p. ; membrana manifeste striata, 20-25 /* crassa in
partibus adultioribus ; ramulis minus moniliforuiibus, nodis
autem semper manifeste constrictis, circa 60 /* diam.

Frond little branched, dichotomous below, branches divergent,
lowest cells of the branches usually adherent for about half
their length; cells of the branches #-2 diam. long, usually a
little longer than wide, much inflated at the middle, up to 145 M,
at the ends only 75-80 /* ; wall manifestly striate, in the older
parts 20-25 M thick ; ramuli less moniliform, but always dis-
tinctly constricted at the nodes, about 60 M diam. Floating in
a pond at Los Angeles, California, Feb., 1915. N. L. Gardner,
No. 2570. Type in herb. F. S. Collins.

THE GREEN ALGAE OF NORTH AMERICA 85

The fronds are often so little branched that one finds an un-
branched filament several cm. long : the general appearance is
then much that of a marine Chaetomorpha with short swollen
cells and thick wall. Its nearest relative would seem to be
C. insignis, but C. monilifonnis has much shorter and more
uioniliform cells and thicker wall. If C. frada is to be taken
to include all non-attached species outside the subgenus Aega-
gropila, the present form should be included in it as a variety ;
but to include in C. frada, C. insignis, C. oligodona and the
present form, would make C. frada altogether more cumbrous
and unsatisfactory than it is now ; it is already bad enough.

Page 367, after description of the genus BOODLE A, add,

B. SIAMENSIS Reinbold, 1901, p. 107; in Weber, 1913, p. 68,
fig. ii ; Borgesen, 1913, p. 49, figs. 34-36. Somewhat intricate
and spongy ; main filaments rather distantly branched, branches
densely and divaricately branching in all directions ; ramuli
here and there adherent by tenacula on their obtuse tips ;
length of cells variable, in main filaments up to 20 diam. ; diam.
of main filaments 160-200 p, rarely 300 p., ramuli 70-100 /*. Vir-
gin Islands. Eastern Asia.

Cancel all relating to B. COMPOSITA.

After description of the genus DICTYOSPHAERIA, add,

• KEY TO THE SPECIES OF DICTYOSPHAERIA.
i. Frond hollow ; interior of cell wall without acicular projections.

i. D.favulosa.
i. Frond solid; acicular projections within the cells.

2. D. van Bosseae.

After description of D. FAVULOSA, add,

2. D. VAN BOSSEAE Borgesen, 1912, p. 256, figs. 7-9 ; 1913,
P- 39. fig8- 23~25- Frond irregularly rounded or hemispherical,
solid, cells rounded-polygonal, about one-half mm. diam., with
acicular projections from the interior cell wall. Virgin Islands.

Distinguished from D.favulosa by the always solid frond and
usually smaller cells, averaging 500 /* diam., seldom reaching
800 /*, while those of D. favulosa average over i mm. D. Vers-
luysii of the Malayan Archipelago has a solid thallus, and
acicular projections into the cells, but the cells are twice the
size of those of D. van Bosseae, and the acicular projections long
in proportion.

86 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

Page 368, HORHISCIA, first line, cancel all in first paragraph
after "several pyrenoids," and substitute,

Asexual reproduction by macrozoospores, many in a cell,
obovoid, extending into a long projection below, and with 4
cilia above ; also by microzoospores in still larger numbers in a
cell, with 4 cilia and red stigma, but with less conspicuous pro-
longation below ; also by akinetes formed by the breaking up
of the filaments into individual cells, with thick wall, either
producing new filaments or zoospores ; sexual reproduction by
small male and larger female 2-ciliate gametes (Wille, 1909,
p. 115) ; also by isogamous 2-ciliate gametes (?).

Page 369, after note on HORMISCIA WORMSKJIOLDII, add,

H, tctraciliata Frye & Zeller, 1915, p. 9, PI. II, seems to be
a synonym of this species. It has macrozoospores similar to
the zoospores of //. penicilliformis, also smaller 4-ciliate spores,
supposed by the authors to be gametes, but probably microzoo-
spores. Macro-and microzoospores are known in many genera
of green algae, but there is no record of 4-ciliate gametes in the
Cladophoraceae, and in other families they are quite excep-
tional. Their figure 20, " gametes fusing," would seem rather
to represent two imperfectly separated microzoospores.

Page 372, for Key to the Species of Valonia, substitute,

i. Frond bullate, unbranched. i. V. vtntricosa,

i. Frond more or less abundantly branched. 2.

2. Branches in whorls. 5. V. cottffrvoides.

2. Branches not whorled. 3.

3. Cells spherical, ovoid or pyriform. 6. V. tnacrofihysa.

3. Cells cylindrical to clavate. 4.

4. Cells distinctly clavate, rather stout. 2. / '. utriculosa.

4. Cells nearly or quite cylindrical, slender, densely branched.

3. V. aegagropila.

Page 373, after description of VALONIA UTRICULARIS, add,

Forma CRUSTACEA Kuckuck, 1907, p. 180; Borgesen, 1913,
P- 30, figs. 17-18; P. B.-A., No. 2074. Forming dense, crisp
lUiMM in shallow water, both in quiet pools and on exposed
reefs. Bermuda, Virgin Islands. Enrofx.

P*g« 373» after V. VERTICILLATA, add,

V. vtrticillala is made the type of a separate genus,

KRNODESMIS Borgesen, 1912, p. 259.

Frond with erect main axis, attached by rhizoids, claviform,
annulately constricted near base, apex obtuse, bearing a whorl

THE GREEN ALGAE OF NORTH AMERICA 87

of similar cells, but with only one constriction near base ; simi-
lar branching to the fourth order ; zoospores formed in ultimate
ramuli, escaping by numerous minute openings. Fig- 27

Differs from Valonia by the regularly whorled branching,
borne on a distinct axis, the presence of annulations, and the
absence of lentiform cells. .

Only one species, E. VERTICILLATA (Kiitz.) Borgesen, 1912,
p. 259, figs. 10-12; 1913, p. 66, figs. 51-54.

Page 374, after description of V. CONFERVOIDES, add,

6. V. MACROPHYSA Kiitzing, 1843, p. 307 ; 1856, p. 30, PI.
LXXXVII, fig. 3; Kuckuck, 1907 /p. 158, figs. 5-10; Borge-
sen, 1912, p. 243; 1913, p. 29; V. utricularis Alg. Am.-Bor.
Exsicc., No. 171. Cells spherical to pyriform with similar
proliferations, solitary or forming more, or less dense masses ;
zoospores 4-ciliate. Bermuda, W. I. Europe.

Often confused with V. utricularis, but in the latter the normal
form of the cell is clavate, while in the present species it is
short pyriform. In both species, however, there is considerable
variation.

Page 376, for Key to the Species of Struvea, substitute,

I. Stipe unbranched. 2.

i. Stipe branched. 3.

2. Frond 3-5 cm. high, with 4-6 pairs of branches, i. S.anastomosans.

2. Frond 7-10 cm. high, with 10-15 pairs of branches. 4. S. elegans.
3. Each branch of stipe with a separate network. 4.

3. One network only. 2. S. pulcherrinta.

4. Branches of stipe opposite. 3. S. ramosa.

4. Branches of stipe irregular. i. S.anastomosans.

Page 377, after description of S. RAMOSA, add,
4. S. ELEGANS Borgesen, 1912, p. 264, figs. 13-14; 1913,
p. 51, figs. 37-38. Stipe cylindrical, 7-10 cm. high, with a few
annulations near the base, unbranched, bearing above a single
ovate pyramidal network, up to 4 cm. long, of 10-15 Pairs °f
opposite branches, with similar branching to the fourth order.
Virgin Islands.

Resembling .5". anastomosans, but a larger plant, with long
simple stipe, and with the branching network ovate acuminate
rather than broadly triangular ; the branching is more regularly
distichous, and there are several distinct aunulations near the
base of the stipe. 51. anastomosans sometimes has one or two

88 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

irregular branches to the stipe. 6". elegans has been found in
deep water dredging only.

Page 387, for Key to the species of Codium, substitute,
i. Forming a continuous expanded incrustation. 2.

i. Not forming a continuous incrustation. 3.

2. Utricles 50-100 M diam., rarely more.- i. C. ditnorphutn.

2. Utricles 125-200 /* diam., rarely to 300 M- 2. C. differing.

3. Frond globose to pyriform. 3. C. Ritteri.

3. Frond branched, cylindric or compressed. 4.

4. Frond creeping. 5.

4. Frond erect. 6.

5. Utricles 150-300 M diam. 4. C. repens.

5. Utricles 70-90 n diam. 10. C. interte.vtum.

6. All or part of the utricles tnucrouate. 9. C. fragile.

6. Utricles blunt, smooth. 7.

7. Branches usually constricted at base ; utricles 200-300 M diam.

6. C. isthmocladnm.
7. Branches not usually constricted at base. 8.

8. Frond normally cylindric throughout ; utricles seldom reaching
200 M diam. 5. C. tomenlosum.

8. Frond normally more or less compressed. 9.

9. Utricles seldom less than 300 M diam. ; compression chiefly at axils.

7. C. dfcorticatum.

9. Utricles usually less than 250 M diam. ; often compressed throughout.

8. C. Lindenbergii.

Cancel paragraph beginning " i. C. ADHAKRENS" and fol-
lowing paragraph, and substitute,

i. C. DIMORI-HUM Svedelius, 1900, p. 300, PI. XVII, figs.
16-19; A. M. Kurd, 1916, p. 211, PI. XXXVII; C. adhaerens
P. B.-A., No. 523, not of Agardh. Frond prostrate, dark green,
about 5 mm. thick, margin irregularly lobed ; interior of slender
filaments, exterior of utricles 50100/1 diam., commonly 75 /*,
the end wall sometimes thin, sometimes much thickened, show
ing distinct stratification. No hairs present. Pacific coast from
Alaska to San Diego. Patagonia.

It is unlikely that true C. adhaerens occurs in North America.
All specimens from the Pacific coast as far as examined prove to
be C. dimorphum, all from the Atlantic coast C. diffornte or
C. intcrtextum. In C. dimorphum the differentiation of the
utricles as to the character of the end wall is quite marked, the
two forms usually occurring on the same individual, and in
different parts of the frond. C. adhaerens produces abundant

THE GREEN ALGAE OF NORTH AMERICA 89

hairs when young, no hairs are found on C. dimorphum. Other
details of difference will be found in Svedelius' and Miss Kurd's
papers.

Page 99 of supplement, after note on CODIUM DECORTI-
CATUM, add,

Var. CLAVATUM Collins & Hervey, 1917, p. 56. Densely
branched, firmer, less gelatinous ; utricles very variable, mostly
clavate, capitate, bell-shaped or turbinate, length 480-980 /*,
diam. from 80 \L in- the middle of the smallest utricle to 480 /u. at
the summit of the largest. Bermuda.

A large deep-water form, firm and not collapsing when fresh,
but becoming papery when dried.

Page 99 of supplement, after notes on CODIUM FRAGILE, add,

10. C. INTERTEXTUM Collins & Hervey, 1917, p. 54;
P. B.-A., No. 2018. Frond prostrate, subterete or flattened,
closely adherent to the rock, but with tips usually free ; with
short irregular branches forming an almost continuous coating.
Utricles long, cylindrical or subclavate, 70-90 p. diam., ends
truncate or somewhat rounded. Color dark green, substance
firm, not specially gelatinous. Forming a continuous belt a few
dm. wide on upright or sloping rocks at low water mark.
Bermuda, W. I.

As noted under C. dimorphum, Atlantic records of C. adhaerens
on the North American coast should be mostly referred to this
species.

Page 389, and p. 99 of supplement, for Key to the Species of
Avrainvillea, substitute,

I. Upper part a distinct flabellum. 2.

I. Upper part digitately lobed. i. A. Kawsoni.

2. Surface of flabellum smooth or smoothish. 3.

2. Surface of flabellum velutinous, spongy or strigose. 6.

3. Filaments of flabellum of nearly uniform diam. throughout.

5. A. Elliottii.

3. Filaments distinctly tapering. 4-

4. Filaments 30-40 M diam. below, diminishing towards the surface,

but ends clavate. 6. A. Geppii.

4. Filaments smaller, tips not clavate. 5-

5. Filaments towards the surface torulose, densely matted.

7. A, asari folia.
5. Filaments little or not at all torulose, not so dense near surface.

3. A. levis.

90 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

6. Interior filaments moniliforui. 2. A. nigricans.

6. Interior filaments cylindrical, with basal constrictions.

4. A. longicaulis.

Page 391, after description of A. LONGICAULIS, add,

6. A. GEPPII Bbrgesen, 1913, p. 87, figs. 71-72. Frond i2cm.
high, rhizome erect, 2 cm. high, i cm. diatn. ; stipe l/3 cm.
diain., 5 cm. high, suddenly expanding into a transversely ob-
long flabellum, 5.5 cm. high, 8 cm. wide, of rather loose con-
sistency, slightly zonate, becoming very thin near the edge ;
filaments cylindrical or sometimes here and there subtorulose,
30-40 /* diam., diminishing to 14-17 ^ at the surface, apices
stouter, subclavate or obtuse, 17-25, rarely 27 n diam ; color of
dried specimen gray-green with dull yellow tinge. Dredged
in about 16 meters, Virgin Islands, Borgesen.

Only a single specimen is known. As noted, Collins, 1909,
p. 390 and 391, 1912, p. 100, the species of Avrainvillta leave
much to be desired, both as to distinction of species and as to
nomenclature.

7. A. ASARIFOLIA Borgesen, 1908, p. 34, fig. 4, PI. Ill;
19'3» P- 89« fiKs- 73-75; Gepp, 1911, p. 44. Rhizome terete,
stipe cylindrical below, flattened above, 6-23 cm, long, 7 mm.
diam. ; flabellum oblong-reniform or cordate, to 10 cm. high
and 14 cm. wide, entire or lobed, of rather firm consistency and
usually distinctly zonate ; surface subglabrous ; filaments of the
interior cylindrical or sometimes slightly moniliform, with a
rather strong constriction above the dichotomy ; diam. of fila-
ments 20-30 n, usually 24-27 ft ; tapering towards the surface
and becoming more torulose and more abundantly ramified, ami
firmly interwoven; outermost filaments 8-13^1 diam. ; color of
dried specimens dark olive green ; substance firm. Dredged in
20-30 meters, Virgin Islands, Borgesen.

Quite close to A. levis, but considered distinct by Borgesen
and Gepp.

Page 392, after description of PBNICILLUS DUMBTOSUS, add,

Forma KXPANSUS Borgesen, 1913. p. 101. Head larger and
looser, its diam. much greater than length of stipe ; stipe 2-4 ctn.
long, head 14-17 cm. diam. Dredged in about 30 meters, Virgin
Islands, Borgesen.

Page 393, after description of P. PYRIFORMIS, add,

Forma KXPLANATUS Borgesen, 1913, p. 99, fig. 81. Filanu-nts
of head looser than in the typical form, horizontally expanded

THE GREEN AI.GAE OP NORTH AMERICA 91

to a diameter of 10 cm. or more. Dredged in about 40 meters,
Virgin Islands, Borgesen.

The horizontally expanded filaments of the head seem to be
an adaptation to its deep water habitat ; otherwise it is of the
typical form.

Page 394 and p. 102 of supplement, for Key to the Species of
Udotea, substitute,

i. Whole flabellum with a stony coating. 2.

i. No general stony coating. 3.

2. Branches forming the cortex of the flabellum capitate.

6. U. occidentalis.

2. Cortical filaments not capitate. 5. U. Flabellum.

3. Flabellum with a cortex of spinulose branches. 4.

3. Flabellum uncorticated. 5.

4. Spinulose branches in close whorls. 43. U. verticillosa.

\. Spinulose branches subsecund or irregular. 4. U. spinulosa,
5. Flabellum plane. 2. U. conglutinata.

5. Flabellum concavo-convex to cyathiform. 3. U. cyathiformis .

Page 396, after description of UDOTEA ARGENTEA, add,

RHIPILIA Kiitzing, 1858, p. 12.

Uncalcified, green, cuneato-flabellate to excentrically subin-
fundibuliform, stipitate, stipe thin, flabellum thick or thin,
sometimes zonate, composed of a lax felt of dichotomously
branched filaments, often not cylindric, bearing rather short,
pseudo-lateral branchlets, each terminating in a 2-6-parted ten-
aculum or crown.

Differs from Udotea by the absence of incrustation ; from
Avrainvillea by the terminal tenacula.

R. TOMENTOSA Kiitzing, 1858, p. 12, PI. XXVIII, fig. i ;
Gepp, 1911, p. 55, PI. XV, figs. 126-128; Udotea tomcntosa
Collins, 1909, p. 394; Avrainvillea laetevirens Maze". No. 233.
Fig. 28. Guadeloupe.

Forma ZONATA Gepp, 1911, p. 55, PI. XV, fig. 129; Borgesen,
1913, p. 93, fig. 76. Stipe more slender than in the typical
form, frond round-flabellate or reniform, thin, translucently
zonate. Dredged in about 30 meters, Virgin Islands, Borgesen.

Page 399, after description of HALIMEDA GRACILIS, add,

Var. OPUNTIOIDES Borgesen, 1913, p. 108, fig. 87. Segments
large, up to 14 mm. wide and 9 mm. high, suboval-reniform,
often distinctly crenulate on the upper margin or even trilobed.
Dredged in about 30 meters, Virgin Islands, Borgesen.

92 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

Shape of segments very much as in H. Opuntia, but all in
one plane.

Page 403 after description of BRYOPSIS DUCHASSAINGII, add,

Var. FILICINA Collins & Hervey, 1917, p. 61. Outline of
frond broadly or narrowly lanceolate ; main axis not divided;
secondary axes closely and uniformly set, often opposite, densely
beset from the base with very fine ramuli of equal length.
Bermuda.

The very regularly pinnate branching gives the fronds in this
variety an appearance quite different from that of the typical
form.

Page 406, for Key to the Species of Derbesia, substitute,

I. Filaments 100-600 M diam. . 3. D. Lamourouxii.

i. Filaments less than 100 M diam. 2.

2. Sporangia ovoid to subspherical. 2. D. marina.

2. Sporangia obovoid to broadly pyriform. 3.

3. Pedicel cell 2-4 diam. long. i. D. vaucheriaeformis.

3. Pedicel cell i diam. long or less. 4. D.turbinata.

Page 407, after description of D. LAMOUROUXII, add,
4. D. TURBINATA Howe & Hoyt, 1916, p. 107, PI. II, figs.
10-16. More or less prostrate : filaments 15-95 fidiam., mostly
38-53 /*, sparingly branched, branches subdichotomousor oftener
lateral ; lateral branches without septum ; dichotomies with or
without i or 2 septa; sporangia broad-pyriform or turbinau-.
112-182 /x long, 104-156 wide ; pedicel 14-32 /* long, rarely up to
70 /&, 15-21 /idiam. ; pedicel cell cuboidal, 18-21 p, or shorter,
10-21 M- Dredged in 28 meters depth on reef 23 miles off Beau-
fort, N. C., Lewis Radcliffe.

Page 427, after account of VAUCHERIA GEMINATA var. K \e>:
MOSA, add,

Var. DEPRESSA Transeau, 1917, p. 228. Fertile branch
short, oogonial branches longer than in the type, and depressed,
bringing the oogonia to the level of the filament or below. 111.,
Mich., Transeau.

Perhaps to be compared with V. uncinatn Kiitz. and V. Wor-
on in tana forma ficndula Heering.

THE GREEN ALGAE OF NORTH AMERICA 93

LIST OF WORKS TO WHICH REFERENCE IS MADE.

This list includes only works not included in similar lists in
Collins, 1909 and 1912 ; references in the text to works included
in those lists use the abbreviations given in those lists.

Archer, W. 1872. Notice of the genus Tetrapedia (Reinsch)

... Quar. Jour. Micr. Sci., Vol. XII, p. 351.
Bachmann, H. 1908. Vergleichende Studien iiber das Phy-

toplankton von Seen Schottlands und der Schweiz.

Archiv fur Hydrobiologie und Planktonkunde, Vol.

Ill, p. i.
Bennett, A. W. 1892. Freshwater Algae and Schizophyceae

of South-west Surrey. Jour. Roy. Micr. Soc., p. 4.
Borge, O. 1894. Siisswasser-Chlorophyceen gesatnmelt von

Dr. A. Osw. Kihlmann im nordlichste Russland. . . .

Bih. Kong. Svensk. Akad. Handl., Vol. XIX, Afd.

Ill, No. 5, p. i.
1900. Schwedische Siiswasserplankton. Bot. Notiser, p. i.

1906. Siisswasser-Chlorophyceen von Feuerland und Isla
Desolacion. Bot. Stud, tillagnade F. R. Kjellraan,
p. 21.

1907. Beitrage zur Algenflora von Schweden. Arkiv for
Bot., Vol. VI, No. i, p. i.

Borgesen, F. 1912. Some Chlorophyceae from the Danish

W. I., Bot. Tidsskrift, Vol. XXXII, p. 241.
1913. The marine algae of the Danish W. I., part I,
Chlorophyceae. Dansk Bot. Arkiv., Vol. I, No. 4.

Brand, F. 1902. Die Cladophora-Aegagrppilen des Siisswas-

sers. Hedwigia, Vol. XLJ, p. 34-

1907. Ueber charakterische Algen-Tinktionen .... Ber.
Deutsch. Bot. Ges., Vol. XXV, p. 497.

Brebisson, A. de. 1856. Liste des Desmidiees observers en
Basse Normandie. Mem. Soc. Imp. Sci. Nat. Cher-
bourg, Vol. IV, p. 113.

Chodat, R. 18943. Golenkinia, nouveau genre de Protococ-
coid£es. Jour, de Bot., Vol. VIII, p. 305.

94 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

i.&95a. Materiaux pour servir a 1'histoire des Protococ-

coide*es. Bull. Herb. Boissier, Vol. Ill, No. 3, p. 109.
18955. Surle genre Lagerheimia. Nuova Notarisia, p. 86.
1913. Monographies d' algues en culture pure. Materiaux

pour la flore cryptogamique Suisse, Vol. IV, fasc. 2.
Cohn, F. 1879. Desmidiae Bongoenses. Festschrift d. Naturf.

Ges. zu Halle.
Collins, F. S. 1912. The green algae of N. A., supplementary

paper. Tufts Coll. Studies, Vol. Ill, p. 69.
Collins, F. S. & Hervey, A. B. 1917. The algae of Bermuda.

Proc. Amer. Acad., Vol. LIII, p. i.

Corda, A. J. C. 1838. In Almanach de Carlsbad, Prague, 1839.
Davis, B. M. 1894. Notes on the life history of a blue green

motile cell. Bot. Gazette, Vol. XIX, p. 96.
Ehrenberg, G. C. 1848. Beobachtung zweier generisch neuer

Fornien der Friihlingsgewassers bei Berlin. Monats-

ber. Akad. Wiss. Berlin, p. 233.
Francd, R. 1894. Recherches sur le genre Phythelios Freuzel.

Notarisia, p. i.
Fresenius, G. 1858. Beitrage zur Kentniss mikroskopischen

Organismen. Abh. Senckenberg. Naturf. Ges., Vol.

II, p. 211.
Frye, T. C. & Zeller, S. M. 1915. Hormiscia tetraciliata sp.

nov. Puget Sound Marine Station Publ., Vol. i, p. 9.
Gardner, N. L. 1917, New Pacific coast marine algae, I.

Univ. Calif. Publ., Bot., Vol. VI, p. 377-
Gerneck, R. 1907. Zur Kentniss der niederen Chlorophyceen.

Beihefte zum Bot. Centralblatt, Vol. XXI, Abt. 2,

p. 221.
Gobi, C. 1887. Peroniella Hyalothecae, eine neue Siisswas-

seralga. Schrift. Bot. Hort. Univ. Imp. Petrop.,

Vol. I, p. 244.
Hansgirg, A. i888b. UebcrdieGattungen Herposteiron Nag.

und Aphanochaete Berth, non A. Br. Flora, Vol.

LXXI, p. 212.
Hauck, F. 1876. Verzeichniss der im Golfe von Triest ges-

ammelter Meeresalgen. Oest. Bot. Zeitschr., Vol.

XXVI, p. 54-

THE GREEN ALGAE OF NORTH AMERICA 95

Hill, G. H. 1916. Spirogyra gigantica n. sp. Puget Sound

Marine Station Publ., Vol. I, p. 198.
191 6a. Origin of the second spiral in Spirogyra lutetiana.

Puget Sound Marine Station Publ., Vol. I, p. 247.
Howe, M. A. 1914. The marine algae of Peru. Mem. Torrey

Bot. Club, Vol. XV, p. i.
Howe, M. A. & Hoyt, W. D. 1916. Notes on some marine

algae from the vicinity of Beaufort, N. C. Mem. N. Y.

Bot. Garden, Vol. VI, p. 105.
Kurd, A. M. 1916. Codium dimorphum. Puget Sound

Marine Station Publ., Vol. I, p. 211.
Kindle, E. M. 1915. Limestone solution in the bottom of

Lake Ontario. Amer. Jour. Sci., Vol. XXXIX, p.

651-
Kirchner, O. 1880. Beitrage zur Algenflora von Wiirttem-

berg. Jahresh. Vereins fur Vaterlandischer Natur-

kunde, Vol. XXXVI, p. 155.
Kjellman, F. R. iSgjb. Marina Chlorophyceer fran Japan.

Bih. Kgl. Svensk. Akad. Handl. Stockholm, Vol.

XXII, No. ii.
Kofoid, C. A. 1914. Phytomorula regularis, a symmetrical

protophyte related to Coelastrum. Univ. Calif. Publ.,

Bot., Vol. VI, p. 35.
Kutzing, F. T. 1857. Tabulae Phycologicae, Vol. VII.

1858. Tabulae Phycologicae, Vol. VIII.
Lagerheim, G. von. 1888. Sopra alcune alghe nuove o rimar-

chevole. Notarisia.
i895a. Studien u'ber die arktische Cryptogamen. I.

Tromso Mus. Aarsheft., Vol. XVII, p. i.
Lemmermann, E. iSgSc. Beitrage zur Kentniss der Plank-

tonalgen, II. Bot. Centralblatt, Vol. LXXVI, p. 150.
18993. Correction of date for 18983, in Collins, 1909.
1900. Beitrage zur Kentniss der Planktonalgen, VI. Ber.

Deutsch. Bot. Ges., Vol. XVIII, p. 94.

1903. Beitrage zur Kentniss der Planktonalgen, XVI.
Bot. Notiser, p. 95.

1904. Das Plankton schwedischer Gewasser. Arkiv. for
Bot., Vol. II, No. 2, p. i.

96 TUFTS COLLEGE STUDIES, VOL. IV, No. 7

1914. Algologische Beitrage. XII. Die Gattung Char-
aciopsis Borzi. Abh. Nat. Vereins Bremen, Vol.
XXIII, p. 249.

Lewis, I. F. 1916. Notes from the Woods Hole Laboratory,

1915. Rhodora. Vol. XVIII, p. 90.

McClatchie, A. J. 1897. Seedless plants of Southern Cali-
fornia. Proc. Southern Calif. Acad. Sci., Vol. I,

P- 337-
Moore, G. F. 1917. Algological Notes. I. Chlorochytriuui

gloeophilum Bohlin. Ann. Missouri Bot. Garden,

Vol. IV, p. 271.

Nageli, C. 1849. Correction of date for 1848, in Collins. 1909.
Nitardy, E. 1914. Zur Synonymic von Pediastrum. Beihefte

zum Bot. Centralblatt, Vol. XXXII, Abt. 2, p. in.
Nordstedt, O. 1873. Beskrifning ofver en ny art af slagtet

Spirogyra. Lunds Univ. Arsskrift, Vol. IX, p. i.
Nowakowski, L. 1877. Beitrage zur Kentniss der Chytridia-

ceen. Cohn's Beitr. zur Biologic der Pflanzen, Vol. II,

P- 73-
Okamura, K. 1907—1916. Icones of Japanese Algae. Tokyo.

Ostenfeld, C. H. 1907. Beitrag zur Kentniss der Algenflora
des Kossogol-Beckens .... Hcdwigia, Vol. XLVI,

P- 365-

Pascher, A. 1914. Die siisswasser- Flora Deutschlands, Oes-
terreichs und der Schweiz, Heft. 6.

1915. Die Siisswasser- Flora Deutschlands, Oesterreichs und
der Schweiz, Heft. 5.

Powers, J. H. 1907. New Forms of Volvox. Trans. Amer.

Micr. Soc., Vol. XXVII, p. 123.
1908. Further studies in Volvox. Trans. Amer. Micr.

Soc., Vol. XXVIII, p. 141.
Printz, H. 1913. Eine systetnatische Uebersicht der Gattung

Oocystis. Nyt Mag. Naturvidenskab, Vol. LI, p. 165.

1914. Kristianiatraktens Protoccoideer. Vidensk. Selsk.
Skrifter, Kristiania, No. 6.

1915. Beitrage zur Kentniss der Chlorophyceen ....
Kgl. Norsk. Vidensk. Selsk. Skr. Trondhjem, No. 2.

THE GREEN ALGAE OF NORTH AMERICA 97

19153. Die Chlorophyceen des siidlichen Sibiriens nnd

des Uriankailandes. Kgl. Norsk. Vidensk. Selsk.

Skr. Trondhjem, No. 4.
Raciborski, M. 1890. Przeglad gatunkoro rodzaju Pediastrum.

Mem. Acad. Imp. Sci. Cracow, Vol. XX, p. 84.
Reinbold, T. 1901. Marine Algae, in Flora of Koh Chang by

Jobs. Schmidt. Bot. Tidsskrift, Vol. XXIV, p. 103.
Reinsch, P. F. 1866. De speciebus generibusque nonnullis

novis . . . Abh. Senckenb. Naturf. Ges., Vol. VI,

p. in.
1877. On freshwater algae from the Cape of Good Hope.

Jour. lyinn. Soc., Bot., Vol. XVI, p. 232.
Richter, P. 1896. Scenedesmns opoliensis P. Richt. nov. sp.

Zeit. fur ang. Mikr., Vol. I, p. i.

1897. Botanische Ergebnisse der von der Gesellschaft fur
Erdkunde zu Berlin ausgesandten Gronlandexpedition.
. . . Bibl. Bot., Vol. VIII, Heft. XUI, p. 6.

Schmarda, Iy. K. 1850. Neue Formenvon Infusorien. Denkschr.

Wiener Akad., Vol. I, abt. 2, p. 9.
Schmidle, W. 1896. Algologische Notizen. I. Allg. Bot.

Zeitschr., p. 192.
iSgga. Ueber Planktonalgen und Flagellaten aus dem

Nyassa See. Engler's Bot. Jahrb., Vol. XXVII, p. 229.
1900. Beitrage zur Kentniss der Planktonalgen. Ber.

Deutsch. Bot. Ges., Vol. XVIII, p. 135.
igooa. Algologische Notizen. XV. Allg. Bot. Zeitschr.,

Vol. VI, p. 234.
Schroder, B. i897a. Attheya, Rhizosolenia und andere Plank-

tonorganismen .... Ber. Deutsch. Bot. Ges., Vol.

XV, p. 373-
i897b. Die Algen des Versuchsteich des Schles. Fisch-

vereins zu Trachenberg. Forsch. biol. Sta. Plon.,

Vol. V, p. 29.

1898. Neue Beitrage zur Kentniss der Algen des Riesen-
gebirges. Forsch. biol. Sta. Plon, Vol. VI, p. 23.

1902. Verh. Nat. Med. Vereins zu Heidelberg, N. F.,
Vol. VII, p. 139.

98 TI-FTS COLLEGE STUDIES, VOL. IV, No. 7

Shaw, W. R. 1916. Besseyosphaera, a new genus of the
Volvocineae. Bot. Gaz., Vol. LXI, p. 253.

Smith, G. M. 1913. Tetradesmus, a new four-celled coenobic
alga. Bull. Torrey Bot. Club, Vol. XL, p. 75.

1916. New or interesting algae from the lakes of Wiscon-
sin. Bull. Torrey Bot. Club, Vol. XLIII, p. 471.

19163. A monograph of the algal genus Scenedesmus.

Trans. Wisconsin Acad., Vol. XVIII, p. 422.
I9i6b. A preliminary list of algae found in Wisconsin

lakes. Trans. Wisconsin Acad., Vol. XVIII, p. 531.
Stein, F. von, 1878. Der Organismus der Infusionsthiere.

Leipzig.
Svedelius, N. 1900. Algen aus den Landern der Magellans-

strasse und Westpatagonien. Svensk. Exped. till

Magellanslanderne, Vol. Ill, No, 8.
Tanner-Fulleman, M. 1906. Bull. Herb. Boissier, Series 2,

Vol. VI, p. 156.
Teiling, E. 1912. Schwedische Planktonalgen. I. Sv. Bot.

Tidsskrift, Vol. VI, p. 266.
Teodoresco, E. C. 1908. Materiaux pour la flore algologique

de la Roumanie. Beihefte Bot. Centralblatt, Vol.

XXI, Abt. 2, Heft. 2.
Transeau, E. N. 1914. New species of green algae. Amer.

Jour. Bot., Vol. I, p. 289.
1915. Notes on the Zygnemales. Ohio Jour. Sci., Vol.

XVI, p. 17-

1917. The algae of Michigan. Ohio Jour. Sci., Vol.

XVII, p. 217.

Turpin, J. F. P. 1828. Apercu organographique . . . Mem.

Mus. d'Hist. Nat. Paris, Vol. XVI, p. 295.
Wallich, J. C. 1860. Desmidiaceae of Lower Bengal. Ann.

& Mag. Nat. Hist., Ser. 3, Vol. V, p. 184.
Weber van Bosse, A. 1913. Liste des algues du Siboga.

Siboga Expeditie, Monogr. LIXa, Leiden.
West, G. S. 1907. Report on the fresh water algae ... of

the third Tanganyika Expedition. Jour. Linn. Soc.,

Bot., Vol. XXXVIII, p. 81.

THE GREEN ALGAE OF NORTH AMERICA 99

1909. Phytoplankton from the Albert Nyanza. Jour, of

Bot., Vol. XLVII, p. 244.

1916. Algae, Vol. I, Cambridge Bot. Handbooks.
West, W. & G. S. 1894. New British fresh water algae.

Jour. Roy. Micr. Soc., p. i.

1898. Notes on fresh water algae. Jour, of Bot., Vol.

XXXVI, p. 330.

1899. Alga-flora of Cambridgeshire. Jour, of Bot., Vol.

XXXVII, p. 49.

1 90 1 a, Fresh water Chlorophyceae, in Flora of Koh Chang

by Jobs. Schmidt. Bot. Tidsskrift, Vol. XXIV.
1902. A contribution to the fresh water algae of the North
of Ireland. Trans. Roy. Irish Acad., Vol. XXXII,
Sect. B, part I, p. i.
1904. Fresh water algae from the Orkneys and Shetlands.

Trans. Bot. Soc. Edinburgh, Vol. XXIII, p. 3.
Wildemann, E. de. 1897. Encore le Pleurococcus nimbatus

de Willd. Bull. Herb. Boissier, Vol. V, p. 532.
Wille, J. N. F. 1900. Algologische Notizen. I-VI. Nyt

Mag. for Naturv., Vol. XXXVIII, p. i.
iQosa. Ueber einige von J. Meyenhardt in Siidafrika
gesammelte Siisswasseralgen. Oest. Bot. Zeitschr.,
Vol. LIU, p. 89.

Woloszyuska, Jadriga. 1914. Studien iiber das Phytoplank-
ton des Victoriasees. Hedwigia, Vol. LV, p. 184.
Yendo, K. 1914. Notes on algae new to Japan. Bot. Mag.
Tokyo, Vol. XXVIII, p. 263.

EXPLANATION O'F PLATES.

PLATE I

i. (a) Peroniella planctonica, after Smith. X 1200.

1. (£) " " " " X 1200.

2. (a) Mischococcus confervicola, after Nageli. X 45°-
2. (*) " " " " X 900.

2. (0 " " " " X 900.

3. Cryptoglena americana, after Davis. X 1125.

4. Spondylomorum quaternarium, after Stein. X 800.

ioo TUFTS COLLEGE STUDIES, VOL. IV, No. 7

5. Pyramimonas tetrarhynchus, after Stein. X 1000.

6. (a) Dicranochaete reniformis, after Hieronymus. X 400.

6. (b) " " " " X6oo.

7. Gloeochaete Wittrockiana, after Nordstedt. X 1000.

8. Closteriopsis longissima, var. tropica, after West.

X 520.

9. Quadrigula closterioides, after Printz. X 1000.

PLATE II

10. Glaucocystis nostochinearum, after West. X 1000.

n. Micractinium radiatum, after Chodat. X 800.

12. Franceia ovalis, after Pascher. X 500.

13. Acanthosphaera Zacharaisi, after Pascher. X 800.

14. (a) Elakatothrix gelatinosa, after Wille. X 224.
14- (*) " " . " " X 570.
14- (') " " X 570.
14- 00 X 242.
14- (') X 570.

15. Phytomorula regularis, after Kofoid. X 1125.

16. Tetradesmus wisconsinensis, after Smith. X 3300.

17. (a) Westella botryoides, after West. X 780.

17. (b) " •• " X 1245.

18. Tetrastrum staurogeniaeforme, after Chodat. X 1500.

19. Euastropsis Richteri, after Schmidle. X 1000.

20. Chaetonema irregularis, after Huber. X 300.

PLATE in

21. Geminella scalariformis, after West. X 780.

22. (a) Oedocladium albemarlense, after Lewis. X 200.

22. (b) " •«« V " X 200.

23. Phaeophila floridearum, after Hauck. X 300.

24. (a) Chlorosarcina lacustris, after Snow. X 500.
24- W " X 5°o-

24. (c) X 5°o-

25. Gloeocystopsis limneticus, after Smith. X 1000.

26. (a) Coccomyxa dispar, after Schmidle. X 800.

26. (b) " . •• . •• X 800.

27. Ernodesmis verticillata, after Borgesen. X a.

28. Rhipilia tomentosa, after Gepp. X 40.

THE GREEN ALGAE OF NORTH AMERICA

INDEX.

Synonyms are printed in

italics. The number of a page at which a

species or genus is described

is in bold-faced type.

Acanthosphaera, 35.

Chaetosphaeridium, 72.

Zacharaisii, 35.

ovale, 73.

Achnanthes.

Pringsheimii.

bijuga, 43.

f. conferta, 72.

dimorpha, 42.

Characiopsis, 4.

obliqua, 42.

acuta, 5.

quadricauda, 46.

Borziana, 6.

Actinastrum, 49.

cylindrica, 5.

gracillimum, 49.

ellipsoidea, 4.

Hantzschii, 49.

groenlandica, 5.

Ankistrodesmus.

longipes, 6.

Chodati, 29.

minuta, 5, 6.

lacustris, 29, 30.

Naegelii, 4.

Pfizeri, 30.

pyriformis, 5.

Arthrodesmus.

v. subsessilis, 5.

serratus, 45.

subulata, 6.

Avrainvillea. 89.

turgida, 5.

asarifolia, 90.

Characium, 27.

Geppii, 90.

acutum, 5.

laetevirens, 91.

cylindricum, 5, 28.

levis, 90.

DeBaryanum, 28.

Batrachospermum, 73.

giganteum, 29.

Besseyosphaera, 22.

groenlandicum, 5.

Powersii, 23.

limneticuni, 28.

Boodlea.

longipes, 6.

composita, 85.

minutum, 5.

siamensis, 85.

Naegelii, 4, 28.

Botryococcus.

pyriforme, 5.

Braunii, 25.

rostratum, 28.

Bryopsis.

stipitatum, 28.

Duchassaingii.

subsessile, 28.

v. filicina, 92.

subulatum, 6.

Chaetomorpha, 78, 85.

Chlamydomonas.

antennina. 79.

Braunii, 22.

clavata, 78.

communis, 21.

v. torta. 78.

eriensis, 21.

crassa, 79.

globosa, 21.

Darwinii. 79.

globulosa, 21.

gracilis, 80.

monadina, 22.

Linum, 79.

Snowii, 21.

f. aerea, 79.

stipitata, 28.

media, 79.

Chlorochytriurn, 2j.

rnelagonium, 79.

Cohnii, 26.

minima, 80.

gloeophilum, 26.

moniligera, 79.

Moorei, 26.

spiralis, 78.
torta, 78.

Porphyrae, 26.
Reinhardtii, 26

Chaetonema, 73.

Chlorocystis, 26.

irregulare, 73.

Cohnii, 26.

IO2

TUFTS COLLEGE STUDIES, VOL. IV, No. 7

Chlorosarcina, 76.

lacustris, 76.

parvula, 76.
Cblorosphaera.

lacustris, 75. 76.

parvula, 75. 76.
Cblorotbeciacrae, 3.
Chodatellat 32.

ciliata.
v. minor ; 33.

citri/ormis, 33.

Droescheri, 33.

subsalsa.

v. longiscta, 34.
Cladophora.

corallicola, 82.

fracta, 85

frascatii, 83.

hemispliHt-ru a, 83.

insignis, 85.

moniliforinis, 84.

oligoclona. 85.

piscinae. 82.

profunda. 24.
V. Nordstedtiana, 84.

rcpens, 83.

rigi.lula, 82.

Rndolpbiana.
f. eramosa, 81.

trichotoma.

v. elongnta, 81.

uncinata, 82.
Clostcriopsis. 30.

longissima, 30

v. tropic*. 30.
Coccomyxa. 77.

dispar, 77.
Codium, 88.

adhaerent, 88.

decorticatum.
v. clavatum, 89.

diffornu-, 88.

ditnorphum. 88.

intertextnm, 89
Coclastrntn, 50.

camhricutn.

v. intrrmcdium. SO.

f>nliht tun.

v. intermedium, 50

•cabrutn, SO.
Corlo*pha«-riuin, 28.
Cohniella.

staurogeniaf/ormis, 52.
Colcochaetc.

decoran*. 77.

ikeraMcensi*, 77.
Conferva, 3.

antennina, 79.

clavata, 78.

crassa, 79.

Linum, 79.

media, 79.

repens, 83.
Conjugata.

decussata, 8.
Crucigenia, 47.

apiculata, 52.

crucifera, 48.

fenestrata, 48

irregularis, 48.

Lauterborni, 48.

quadrata, 48.

rectangularis, 48.

tetrapedia, 48.

triangular i 's, 48.
Cryptoglena, 22.

americana, 22.
Debarya, 18.

americana, 19.

decussata, 19.

glyptosperma, 19.
v. formosa, 19.

laevis, 19.
Derbesia.

tnrbinata, 92.
Diapbanosonia, 28.
Dicranochaete, 27.

ri-ni for in i s, 27.
Dictyosphaeria.

van Bosseae, 85.

favnlosa, 85.

Vrisl uysii. 85.
Dimorphococcus.

Innatua, SI.
Blakatotbrix, 40.

americana, 41.

gelatinosa, 41.
Endoderma, 72.

filiforme, 72.
Ernodestnia, 86.

verticillata, 87.
Eua«tropii». S4.

Ricbteri, SS.
Eua strum.

Kichteri, 55.
Pranceia, 35.

ovalit, 35
1 us,,].-,, 41.

americana, 41.

viri.lis. 41
Gayella. 57.

conslricta. S7

polyrhiza. 57.
Geminella, 55.

THE GREEN ALGAE OF NORTH AMERICA

103

interrupts, 55.

marina, 55.

scalariformis, 55.
Glaucocystis, 22, 32.

nostochinearum, 32.
Gloeochaete, 22, 27.

Wittrockiana, 21.
Gloeocystopsis. 76

limneticus, 76.
Golenkinia.

Franzei, 35.

paucispinosa, 34.

radiata, 34.
Gongrosira.

lacustris, 74.
Halimeda.

gracilis.

v. opuntioides, 91.

Opuntia, 92.
Herposteiron.

polychaete, 77.
Hormiscia, 86.

penicillifonnis, 86.

tetraciliata, 86.
Hormospora, 55.

irregularis, 56.

scalariformis, 55.
Hyalotheca.

mucosa, 6.
Hydria n u in .

giganteum, 29

subsessile, 29.
Ineffigiata, 25.
Kirchneriella, 49.

aperta, 50.

con tort a, 49.

elongate, 49.

lunaris, 50.

obesa, 50.

v. aperta, 50.
v. con/or/a, 49.
Lagerheitnia, 33.

ciliata, 33
v. minor, 33.

citriformis, 33.

Droescheri, 33.

longiseta, 34.

snbsalsa, 33
Lyngbya.

confervoides. 72.
Micractinium, 34.

paucispinosum, 34

pusillum, 34.

quadrisetum, 34.

radiatum, 34.
Micrasterias.

pusilla, 39.

Microthamuion, 74.

exiguum, 74.
Mischococcus, 6.

confervicoia, 6.
Mougeotia, 19.

bicalyptiata, 21.

calcarea, 21.

genuflexa.

v. gracilis, 21.

glyptosperma, 19.

gracillima, 21.

gracilis, 21.

robusta

v. biornata, 21

tumidula, 21.
Nephrocytium, 35.

ciosterioides, 30.

obesurn, 35.
Oedocladiuui, 7).

albemarlense, 71.

protonema, 72.
Oedogonium, 58.

actnand riii in. 65, 66.

acrosporum, 69.

americanuui, 70.

australicuin. 66.

consociatum, 65.

crassum, 69.

crenulatum.
y. longiarticulatum, 63.

crispum.

f. inflatum, 64.

cyathigerum, 64.
v. ellipticum, 64.

cymatosporum, 70.

depressum, 69.

foveplatum, 70.

fragile, 65.

gracillimum, 67.

grande.

f. robustutn, 63.

illinoisense, 67

intermedium, 64.

laeve, 70.

macrandrium, 6q.

macrosporum, 67.

Magnusii, 70.

oblongum. 66

obtruncatum, 69.

paludosum.
v. parvisporum. 63.

pauco-costatum. 66

plagiostomum, 62.

pratense, 66.

praticolum, 68.

propinquum, 68.

psegmatosporum, 66.

io4

TUFTS COLLEGE STUDIES, VOL. IV, No. 7

Reinschii, 58, 69.
rufescens.

v. exiguutn. 62.
rugulosum, 71.
tentoriale, 68.
tyrolicuin, 65.
u minimum. +.

v. americanutn, 64.

f. senegalensc. 64.
Vaucherii, 65.
Oocystis, 31.
ciliata, 33.
elliptica, 32.

v. minor, 32.
gloeocystiforuiis, 32.
nodulosa, 31.
novae semliae.

v. maxima, 31.
panduriforuiis. 32.

v. minor, 31.
parva, 31.
rupestris, 32.
Ophiocytium, 3.
bicuspidatuDi, 3.
capitatum.

v. longispinuui, 3.
tnajus.

r. bicuspidalum, 3.
truncatum, 3.
Pal modacty lun, 25.
Palnipdictyon, 25.
varium. 25.
viride, 25.
Pediastrutn, 52.
araneosum, 54.

v. rugulosum, 54.
Boryanutn.

v. longicornr, S3.

r. rugulosum, 54.
duplex.

v. asperum, S3.

v. cornutam, S3-

v. gracilliniutn 54

v. reticulatum 54.
glandulifemm, 54
integrum, 54
Kawraytkii. 54
•calptatam. 54.
Penlcillns.
dametotnt.

f. expaniiuft. 90.
pyriformi*.

f. explanatUK. 90
Peroniella, 6.
Hyalothccae. 6.
planctonicA. 6.
PhaeophiU, 7V

floridearum, 73.
Phytelios.

oval is, 35.
Phytomorula, 50.

regularis, 51.
Polyedriof>sis.

spinulosa, 38.
Polyedriuin.

hastatntn.

v. palatinunt, 40.

hbulatum, 39.

protfiforme, 39.

tetraedricu tn .
v. hast a turn, 40.
v. tor sum, 38.

trigonum.

v. seiigerutn, 37.
Porphyra.

perforata, 26.
Prasiola.

borealis, 57.

stipitata, 57.
Pringsheimia, 73.

Udotae, 73.
Pyramitnonas, 22.

tetrarhynchus, 22.
Quadrigula, 30.

closterioides, 30.
Radiofilum, 56.

conjunctivutn. 56.

flavescens, 56.

irrcgulare. 56

nioniliferuin, 56.
Raphidimn.

ftraunii.
/. lacustris, 29

Chodati, 29.

Pfitzeri, 30.
Retnschiella.

obesa, 38.

longispina, 3.
Rhipilia, 91.

tomentosa, 91.
f. zonata, 91.
Rhizoclonium.

craiilpellitum. 8u.
Richter \ella.

botryoides, 34 •

quadristta, 34.
Rivularia.

Bornetiana, 27.
Scenedeamuft. 41.

abundan*, 45.

v. hrcvicauda, 4$.
v. longicauda. 45.
v. tpicatun, 45.
v. asymmetrical, •

THE GREEN ALGAE OF NORTH AMERICA

105

acuminatus, 42.

v. minor, 43.

v. tetradesmoides, 43.
acutiformis, 44.
alternans, 43.
arcuatus, 44.

v. platjdisca, 44.
armatus, 44.

v. Chodati, 45.

v. subalternans, 45.
Bernardii, 42
bijuga, 43.

v. alternans, 43.

v. flexuosus, 43.

v. irregularis, 44
bijugatus.

v. flexuosus, 43.

v. irregularis, 44.
brasiliensis, 44.
caudatus, 46.

:•. abundans 45.
denticulatus, 44.

v. linearis, 44.
dimorphup, 42.
Hystrix, 45.

v. armatus , 44.
incrassatulus, 43.

v. mononac, 43.
longispina, 46.
longus, 46.

v. brevispina. 46.

v. ellipticus, 46.

v. minutus, 46.

v. Naegelii, 46.
Naegelii, 46.
obliquus, 42.

v. dimorphus, 42.
opoliensis, 47.
quadricauda, 46.

v. abundans, 45.

v. asymmetricus, 45.

v. ellipticus, 46.

v. longispina, 46.

v. maximus, 4f .

v. parvus, 46.

f. horridus, 46.

v. quadrispina, 46.

f. setosus, 46.

v. Westii, 4T.
quadrispina, 46.
serratus, 45.
spicatits, 42.
Schroederia, 29.
Judayi, 29.
setigera, 29.
Selenastt iim.
acuminatum, 43.

Selenosphaeriu m .
americanuin, 51.
hathoris, 51.
Sorastrum, 51.
americanum, 51.
spinulosum.

v. bathoris, 51.
Sphaerozosma, 6.
Spirogyra.
areolata, 17.
Borgeana, 13.
catenaeformis.

v. parvula, 12-
circumlineata, 13.
communis, 12.
condensata, 12.
crassa, 18.

v. formo«a', 13.
daedalea, 14.
decimina.

v. submarina, 12.
diluta, 13, 14.
dubia.

v. longiarticnlata, 13.
ellipsospora, 15.

v. crassoidea, 15.
fallax, 13, U.
Farlowii, 16.
fluviatilis, 13.
iloridana, 16.
gigantica, 18.
Goetzii, 14.
Grevilleana, 13. 16.
hydrodictya, IT.
illinoisensis, 16.
inconstans, 17.
inflata, 13.

v. foveolata, 13.
insignis.
, v. fallax, 17.
irregularis, 18.
Lagerheimii, 13.
longata, 12.
lutetiana, 13, 17.
micropunctnta, 16.
narcissana, 15.
nitida, 12. 14-
novae angliae, 15.
porticalis. 12.

v. tenuispira, 13.
pratensis, 15.
propia, 15.
punctiformis 15.
rectangularis, 16.
reflexa, 16.
reticulata, 1?.
submarine, 12.

io6 TUFTS COLLKGE STUDIES, VOL. IV, No. 7

submaxima, 14.
lenuissima, 13.

v. rugosa, 13.
rarians.

v. minor, 12.

v. acrobiculata, 12.
velata, 14.

T. occidentalis, 14.
Spondylomoram. 22.

quaternarium, 22.
Stau rocarpus.

jrracillimus, 21.
Staurogenia.
apiculata, 52.
1 1- u data, 48.
crucifera, 48.
Lauterborni, 48
rectangularis, 48.
tetrapedia. 48.
Sta u rosperm u in .

gracilli »// « /// , 2 1 .
Stigeoclonintn, 74.
falklandicutii. 75.

Z-. longearticulatimi, 75.
longearticulaium, 75.
Struvea, 87.
anastomo«ans, 87.
elegans, 87.
Tftracoccus.

botryoides, 52.
Tctradesiiuis, 52.

witcoosinensis, 52.
Tetraedron, 35.
•rthrodesmiformr.

v. lobulatum, 40
caudatuin.

v. longispinum, 38.
floridense, 39.
hastatutn, 40.

v. palatioam, 40.
liinncticum, 39.
lohulatuin, 39.

v. polyfurcatutn, 39.
obennm. 38.
pcntaedricum, 38.
planet onicum. 39.
proteifortnr. 39.
pusillum, 39.
r eg u tare.

T. incus, 37.

v. torium, 38.
•pinulosum, 38.
tetragonum.

f. arthrode«mi forme. 40.
tort urn. 38.
trigonnm.

v. setigerum, 37.

victoriae, 40.
Tetrapedia.

setigera, 37.
Tetraspora, 73.
Tetrastrum, 52.

apiculatutn, 52.

staurogeniacformtf, 52
Tribonema, 3.
Tyndarttl, a.

conspicua, 7.
Udotea, 91.

flabellum, 73.

toitientosa, 91.
Ulothnv.

irregulariSt 56.
Valonia.

macrophysa, 87.

tttricularis, 87.
f. Crustacea. 86.

verticillata, 86.
Vaucheria.

geminata.

v. depressa, 92.

uncinata, 92.

Woroniniana.

f. pendula, 92.
Volvox, 23.

aurea, 23, 24

glohator, 23, 25.

perglobator, 25.

spermatospbara. 24.

Weisstnanniana. 24.
Westella. 52.

botryoidea, 52.
/.ygnema.

chalybeosperniutn, 7. H

Collinsiatiuni, 8.

cruciatum.

v. coeruleutn, 8.

cylindricum, 8.

decuasatani, 8.

ericetorujii. 9.
v. terrealre, 9.

intigne, 8.

pectinatum, 7.
v. cOOJipicumn. 7
v. crattum. 7
,-. dtftnsatutn. K.

peHoaporuni, 8. 19

rhychomema, 8.
Xygogonium.

f riff forum, 9.
v , terrestrt, 9.

/att'f, 19.

TUFTS COLLEGE STUDIES, VOL. IV, No. 7.

PLATE I

F. D. Lambert, del.

GREEN ALGAE OF NORTH AMERICA

TUFTS COLLEGE STUDIES, VOL. IV, No. 7.

PLATE II

F. D. Lambert, del.

GREEN ALGAE OF NORTH AMERICA

TUFTS COLLEGE STUDIES VOL. IV, No. 7

PLATE III

F. D. Lambert, del.

GREEN ALGAE OF NORTH AMERICA

1 9. G. E. MARION: Mandibular and pharyngeal muscles of Acan-
thias and Raja {American Naturalist, xxxix, pp. 891-920,
I9°5)- I5 Text-figures.

20. F. W. THYNG: The squamosal bone in tetrapodous Vertebrata,
(Proceedings of the Boston Society of Natural History, xxxii,
pp. 387-425). 3 Plates, i Table, and 20 Text-figures.

21. F. S. COLLINS: The Green Algae of North America. 1 8 Plates.

22. F. D. LAMBERT: Two New Species of Characium (Rlwdora,
Vol. ii, pp. 65-74, Plate 79, April, 1909). i Plate.

23. J. S. KINGSLEY: A Synopsis of the Fixed Hydroids of New
England. 7 Plates.

24. A. C. LANE : Wet and Dry Differentiation of Igneous Rocks.

25. J. S. KINGSLEY : Meristic Homologies in Vertebrates (Ameri-
can Naturalist, Vol. 41, pp. 103-107, 1907).

26. F. D. LAMBERT : An Unattached Zoosporic Form of Coleo-
chaete. i Plate.

27. FRANK S. COLLINS: The Green Algae of North America (Sup-
plementary Paper). 2 Plates.

28. F.- D. LAMBERT: Didymosporangium repens, New Genus and
Species of Chsetophoraceae. i Plate.

29. F. N. BLANCHARD: Two New Species of Stigonema (Rhodora,
Vol. 15, pp. 192-200, Plate 105, November, 1913). i Plate.

30. H. V. NEAL: The Morphology of the Eye-muscle Nerves (Jour-
nal of Morphology, Vol. 25, pp. 1-188, 9 Plates and 4 Text-fig-
ures, March. 1914). 9 Plates.

31. ALFRED C. LANE: Mine Water Composition an Index to the
Course of Ore Bearing Currents (Economic Geology, Vol. IX,
No. 3. April, 1914).

32. GEORGE A. BATES : The Pronephric Duct in Elasmobranchs
(Journal of Morphology, Vol. XXV, No. 2, June, 1914).

33. H. V. NEAL: The Basis of Individuality in Organisms-A De-
fense of Vitalism. (Science, N. S., Vol. 44, pp. 82-97, July, 1916.

34. A. C. LANE : The Keweenaw Fault (Bull.- Geol. Soc. Am., Vol.

27> PP- 93-IO°. i9l6)-

35. V. BUSH: The coupled circuit by the Method of Generalized
Angular Velocities, (Proc. Inst. Radio-Engineers, Vol. 5, No. 5,
PP- 363~382. 191?)-

36. H. V. NEAL: The History of the Eye Muscles (Journal of Mor-
phology ; Vol. 30, pp. 433-453, 20 Text-figures, March, 1918).

This book is DUE on the last date stamped helow

PLEASE DO NOT REMOVE
THIS BOOK CARD^l

University Research Library