44 ZYGOPHYCBiE.
F e n iu m t r u n c a tu m . Rreh. in R a lfs. Desm., p. 162, t. 6.
Frond minute, two to four times as long as broad, cylindrical,
smooth, ends truncate. Zygospore orbicular, smooth, placed
between the dehiscing deciduous empty fronds.
Siz e. Diam. 11-12 (W .) ; diam. 11-12 p (K .) ; length
21-28 p ; diam. 10 p (D.). . t. t r
Breb. Liste Desm. (1856), p. 146. Archer in P/R- Inf.
(1861), p. 751. Delponte Desm. (1878), t. xv., f. 37-dJ.
Grunow Desm. Austr. (1858), p. 501. Notaris Desm. Ital.
(1867), p. 69, t. 8, f. 78. Rabh. Alg. Enr. (1868), P- 121.
Wolle Desm. U.S. (1884), p. 35, t. 5, f. 9, 10, 21, 22. Kiioh.
Alg. Schles. (1878), p. 136.
Fleurotmnium truncatum, Cleve Sver. Desm. (1864), p. 404.
Cylindrocystis tnm ca ia , Breh. fid e Ralfs. (1847).
H ab. In pools.
Wales, Ireland, Cornwall; France, Germany, Sweden,
Austria, Italy, United States.
Plate X V I I ., fig. 4. a, a, living fronds ; I, empty frond j c, zygos-
pore.
F e n iu m d id ym o c a ip um . Lundell Lesm. Suec., p. 85, t. 5, f . 9.
Minute, sub-cylindrical, not constricted in the middle,
scarcely attenuated towards the rounded apices, membrane
smooth. Zygospore geminate, compressed, suhquadrate,
rounded at the angles. ox qq
S i z e . Length 33-38 p ; diam. 14 zygospore 34-38 X -
^^A?clmr Mior. Journ. (1873), xiii., p. 213. Jacobsen Desm.
NcAfios/oi-a’iKraor, Reinsoh. Alg. et Fung. (1874), t. 17, f. 2.
H ab. In ponds, &o.
Cornwall, Ireland, Denmark.
Plate X V I I ., fiy , 6. a, living frond ; I, empty frond; c, zygospore.
F e n iu m c r a s s iu s c u lum . L e Bary Conjug. (1858), p. 73, t. 5 ,f. o-7.
Frond short, cylindrical, three to four times as long as broad.
Cell-membrane wholly smooth.
S i z e . Length 70 p diam. 20 p.
H ab. In rook pools, &o.
Craigendennie Rocks (Scotland), Germany.
Plate X V I I ., fig. 7- a b , living fronds; c, empty frond, after De Bary.
F e n iu m MCooreanum. Archer Micr. Journ. (1864), p. 179, t. 6,
/ . 34-44.
Frond very minute, about one-third longer than broad, sides
somewhat barrel-shaped, ends truncate-rotund, no clear space
with moving granules at the extremities ; zygospore quadrangular,
oblong, compressed, angles mamillate, extremities
nipple-like.
S i z e . 19 x 12 p zygospore 18 x 12 x 14 /x (A.).
Rabh. Alg. Enr. (1868), p. 123.
Penium pusillum, Delponte Desm. (1878), p. 89, t. 15, f. 34-
36. (?)
H ab. In bogs.
Ireland (Featherbed Bog and Lough Bray) ; Italy (?).
Plate X V I I ., fig. 5. a, living fronds; b, the same magnified 1,000
diam. ; c d, zygospores ; e, young zygospore, after Archer.
F e n ium sp in o s p e rm um . Josh. Journ. Bot. (1885), 35, t. 254, / . 10.
Small, about two and a quarter times longer than wide, sub-
cylindrical, with a very slight median constriction ; apices
round, very slightly attenuated ; membrane smooth ; zygospores
in young state globose and smooth, when mature thickly
covered with obtuse projections.
S i z e . Length 33 p ; breadth 25 p ; zygospore 23 p ; length
of processes 7‘^ p.
H ab. In bog pools.
Derrystrasna Bog, Armagh.
Plate X V I I ., fig. 9. a, living frond ; b, empty frond ; c d, zygospores.
F e n ium m in u t i s s im u m . Nordst. Norges Lesm. (1873), fig. 21.
Very minute, about 1^ times longer than broad, subelliptioal,
a little or scarcely constricted in the middle, from thence to the
broadly rounded apices very slightly but gradually attenuated ;
seen vertically, perfectly circular. Membrane smooth, yellowish ;
amylaceous granule single, (?) Zygospore suhquadrate, angles
rounded, a little prominent ; seen vertically and laterally,
broadly elliptical. Membrane yellowish.
S i z e . Length 12-16 p \ diam. 9 -10/x. Zygospore 16 X 14
p (N.).
H ab. In pools,
Scotland, Norway.
Plate X V I I . , fig. 10. a, living fronds ; b, the same magnified more
highly ; c, empty frond; d e, zygospores ; 5 to e, magnified 1,000 diam.
F e n ium la g e n a x io id e s Roy. Micr. Journ. 1884, p. 197, t. 5, f. 6
Joshua Journ. Bot. (1883), p. 292. ’
S i z e . 95x45;ix.
(Description imperfect.)
H ab. In pools.
Isle of Arran, Deeside, Windermere.