40 
XANTHIDIUM, Ebr. 
Frond deeply constricted; segments broader than long, compressed, 
entire, spinous, having a circular cylindrical or conical projection on 
both surfaces near the centre, which is tuberculated or dentate, or 
entire; end view elliptic.—Cooke’s British Desmids, 129. 
X. Smithii, Archer. Cooke’s British Desmids, 133. Frond 
minute, in front vi bout as long as broad, constriction a wide 
notch; segments twice as broad as long, trapezoid; angles rounded, 
each presenting a pair of somewhat divergent, short, minute, acute 
spines ; central protuberance a minute tubercle.— Cooke l.c. 
ines. L ° 
somewhat curved inwards. The typical species is known from Iceland; 
the variation variabilis from New Zealand.” 
Hab.: Burpengary, Dr. Thos. L. Bancroft. 
‘(Plate X., Fig. 15.) 
COSMARIUM, Corda. ; 
Prof. Moebius says :—“Of the species noticed in my earlier work, 
the following were again found on this occasion: C. Seelyanum, Wolle 
(Plate X., Fig. 22); C. Meneghiniit, Bréb., forma; C. obsoletum 
3); ©. reniforme (Ralfs), 
Archer ; var. compressa, Nordst.” Besides these I have observed Pm 
C. sexangulare, Lund. One-fifth part longer than wide; 
constriction deep; sinus linear within and widening outward: . 
Semi-cells more or less hexagonal elliptic; ends truncate, 0S 
obtusely rounded; end view elliptical ; side view circular. Cy bat 
(cell-membrane) finely punctate; diameter, 20-42 »-— Wo p 
Desmids of U.S. of Amer., 69, ; oo 
28 p broad, with a y ae 
the figure in Wolle’s Desmids of the U.S.A. (Pl. 49, Fig. 13) Dade : 
Hab. : Glasshouse Mountains, September, 1892, Dr. Thos. L. Bancroft. 
(Plate X., Fig, 19.) 7 . 
SP. (0. sp.?) Prof. Moebius gives the following deseription | i 
Cc. 
“ Outline seen from the surface approximately circular, but his 
side com : from th 
broad. 
cells straight at the base, then proceeding from each mee 
shape of an arch. Membrane punctate, on the under : 
Rei, mi-cell furnished with several minute spines. In rm | 
mensions this Cosmarium is closely related to 0. — ae with 
Lund., w ose membrane is thickly punctate, but is not veigegneree 
the small spines at the margin.” et . 
Hab.: Port Curtis Distri Tho 
te Se a trict, May and June, 1892, Dr. Tho 
