Wolle Desm. U.S. (1884), p. 44, t. 7, f. 11-12. Arclier in
P r it Inf. (1861), p. 750. Nordstedt Desm. Arct, (1875). p.
15. Cleve Sver. Desm. (1864), p. 495. Lundell Desm.
Snec. (1871), p. 82. Nordstedt Norges Desm. (187.5), p. 44.
Brebisson Liste Desm. (1856), p. 154. Rabli. Alg. Em.
(1868), p. 137. Wille Nov. Sem. (1879), p. 61.
Glosterium (Asteroselene) acutum, Wittrock Scan. Desm.
Glosterium pronum h. acutum, Klebs. Desm. Pruss. (1879),
Stauroceras acutum, Grunow Desm. Austr. (1868), p. 497.
Ecliinella acuta, Lyngb. Hydropby. Dan. (1819), t. 69, G.
Frustulia acuta, Kiitz. Syn. Diat. (1833), p. 637
Glosterium tenerrimum, Kutz. Pby. Germ. (1845), p. 130.
H ab. In marshy and boggy pools.
Sussex, Cornwall, Wales, Lancashire ; France, Gemiany,
Spitzbergen, Sweden, Denmark, Nova Zembla, United States.
Plate X IV ., fig. 5. a, living cells ; I, empty cells ; c, formation of
zygospore.
var. a. Balfs. Desm. p. 177.
Six to twelve times as long as broad, ends subacute.
C lo s te r ium s u b u la tum . {Kutz.') Syn. H a t. 1833, p. 5 38,/. 3.
Ten to twenty times as long as broad. Frond slender,
narrowly lanceolate, slightly and gradually curved and
attenuated to the very acute ends. Empty frond colourless,
without stri®.
S iz e . Diam. of G. acutum, length greater.
Brebisson Liste (1856), p. 154. Notaris Desm. Ital. 62,
t. 6, f. 64.
Frustulia suhulata, Kutz. Syn. Diat. (1833), p. 538, f. 3.
Stauroceras subulatum, Breb. fide Ralfs.
Glosterium acutum, var. /3, Ralfs. Desm (1848), p. 177, t.
30, f. 6, c.
H ab. Amongst Sphagnum.
Plate X V ., fig. 4. a, living cell ; h, empty cell.
C lo s te x ium a c ic u la r e . West. Micr. Journ. (1860), v n i., p. 153,
t. 7 , / . 16.
Frond elongated, very slender, straight, except a t the
extremities, which are v e ry slightly curved downwards,
gradually tapering from th e centre to th e very acute ends.
Empty frond not striate.
Size. 0'5 mm. long; 5 p broad.
Archer Micr. Journ. ii. (1862), p. 31 ; (1866), vi., p. 181.
H ab. In pools.
Yorkshire, Northumberland.
Plate X V ., Jig. 1. a, living cell ; h, empty cell.
C lo stex ium l in e a . Perty. Kleins. Leiens. (1852), y). 20G, t. 1 6 ,/. 20.
Small, slender, straight, gradually attenuated from the
centre to each acute extremity. Empty frond without stri®.
Zygospore sub-cruciate, elliptic in side view.
Size. Diam. 9 p-, 42 times as long (L.) ; 150 X 3 | m (0 .).
Archer Mior. Jonrn. (1866), vi., pp. 71. Lundell Desm.
Sueo. (1871), p. 82. Rabh. Alg. Eur. (1868), p. 139.
Glosterium pronum d. linea, Klebs. Desm. Pruss. (1879), p.
19.
H ad. Floating on th e surface of pools.
Ireland, Essex ; Switzerland.
Plate X V ., fig. 2. a, living cell ; h, empty cell.
C lo s tex ium G iif f ith ii. PerTc. in Micro. Diet., Kd. iii., p. l76.
Frond minute, scarcely curved, acioular, very acute,
smooth.
Archer in P rit. Inf. (1861), p. 750.
Glosterium subtile, Breb. (?)
Our knowledge of this obscure species is very imperfect.
Species omitted.
C lo stex ium e b o x a c e n se . Turner in Trans. Leeds Nat. Club, 1886.
Frond semilunate, four times as long as broad, ends broadly
rounded, upper margin convex, lower concave, never inflated
in the centre, large granules conspicuous in a longitudinal
series, empty frond colourless, without stri®, central, suture
indistinct.
S i z e . 200-220 p long; 50-57 p broad (T.).
Glosterium cucumis, Wolle (not Eh r.), Desm. U.S., p. 40,
t. 6, f. 17, 18.
H ab. In ponds.
Oampsall, Doncaster ; Chapeltown, Leeds.
From data and figures kindly furnished by Mr. W. B.
Turner, b u t too late for insertion in th e ir proper place.
Figures will be given hereafter.