H ab. In ponds.
Wales ; France, Germany, Sweden, Norway, Brazil, United
States.
Plate X L IX ., fig. 6. a, living frond; h, empty frond; e d,
variety ; e f , end views.
Stauzastzum m eg a can th um , Lundell Lesm. Suec. (1871), p . 61,
t. IV.,/. 1.
Of medium size, nearly as long as broad, very deeply constricted,
sinus acute-angled or rectangular ; semi-cells triangular
fusiform and ventricose ; dorsal margin sub-truncate or
slightly convex, attenuated on each side into a stout spine ; end
view three or four-sided ; sides concave, angles produced into a
firm spine ; membrane delicately punctate.
Siz e . Triangular form, 50 X 57 p, ; quadrangular form, 46
X 61 p (L.).
Nordst. Norges Desm. (1873), p. 28. Wolle Desm. U.S.
(1884), p. 121, t. 51, f. 10-12.
H ab. In pools.
Sweden, Norway, United States.
Plate X L IX ., fig. 7. a, living frond; h, empty frond; c, variety;
dy end view.
** Segments smooth, angles in end view not inflated, sides
straight.
Stauzastzum O’M ea z ii. Archer in Nat. Hist. Uev. (1858), p. 254,
t. 21, / . 8-13.
Frond very minute ; segments smooth, ends truncate (or
sliglitly convex ; central constriction in front view somewhat
cuneiform, gradually widening upwards, outer margin truncate,
awns acute, divergent; end view witii three or four acute angles
terminated by an awn, sides straight. Zygospore orbicular,
spinous, spines subulate, acute, ultimately somewhat inflated at
the base.
Siz e . 1 3 x 1 0 p (A . ) .
Archer in Prit. Inf. (1861), p. 738. Nordstedt Norges
Desm. (1873), p. 27. Rabb. Alg. Eur. (1868), p. 204.
Hab. In pools.
Ireland, Norway,
var. (3. End view with three angles, awns longer.
Siz e . 14 x l i p (A.)
H ab. In pools.
Ireland.
Stauzastzum pte zospozum. Lundell. Lesm. Suec. (1871), p. 60,
t. III. , / . 29.
Small, about as long as broad, median incision deep, very
b ro ad ; semi-oells somewhat wedge-shaped, dilated upwards,
dorsal margin truncate, sides straight, angles ^ rather acute,
furnished with a very delicate spine ; end view triangular, sides
straight, angles somewhat acute, delicately cuspidate. Zygospore
rectangular, compressed, the angles produced into a broad lobe,
which resembles the remains of tlie empty semi-cell.
Siz e. 14-15 p ; zygospore 20 X 13 p (L .).
H ab. In pools.
Westmoreland ; Sweden.
Plate L ., fig. 2. a, living frond ; h, empty frond ■, c d e, end views;
/ , zygospore.
Pisset. Journ. Roy. Micr. Soc. (1884),
195, t. 5, / . 5.
S tauzastzum Isevispinum .
IV. , p .
Frond small. Semi-cells in front view sub-triangular, produced
laterally into a somewhat thick, obtuse, hyaline arm, upper
margin concave, sides nearly straight, end view triangular, sides
concave, ends obtuse, colourless; membrane smooth.
S i z e . Length 28-30 p ; diam. 32-85 p ; breadth of constriction
9 p (B.).
H ab. Mountain pools.
Lake District (England) ; Arran (Scotland).
Plate L ., fig. 3. a, living frond ; b, empty frond; c d, end views.
Stauzastzum g labzum. (Xutz.J Ralfs. Lesm. (1848), p. 217.
Segments smooth, in front view cnneate, ends concave or
stra ig h t; spines slender, muoro-like ; end view with three
mncronate angles, sides concave.
S iz e . About 85 p X 26 p.
Archer in Prit. Inf. (1861), p. 738.
Desmidium glabrum, Ehr. Mikr. Leb. S. & N.A. (1848),
Meteorp., t. 1, f. 13.
P hyca strum glabrum, Kutz. Phy. Germ. (1845), p. 137.
Staurastrum dejectum, Eabh. Alg. Eur. (1868), p. 203, in part.
H ab. In pools.
Cornwall, Ireland; Germany.
Plate L,, Jig. 4. a b c, end views.
Segments rough with minute granules.
S tauzastzum lu n a tum . Palfs, Lesm. (1848), p . 124, t. 34, / . 12.
Frond rough with puncta-like granules ; segments externally
Innate, with an awn at each angle ; spines subulate, acute.
i' '■ 1
a :