PALMELLACES, 21 
Dictyosphezrium reniforme. Buln. Hedwigia 1. 22. 
Families aggregated in an irregular form; cells reniform, 
nearly twice as broad as long. 
Size. Cells -008--009 mm. (Rabh.), ‘006-01 x :01-:02 mm. 
(Kirch.), 
Rabh, Alg. iii. 47. Rabh. Exs. 789. Archer in Micro. 
Journ., 1868, viii. p. 65. Kirch. Alg. Schl. p. 106. 
In pools. Near Snowdon, N. Wales. 
“This plant possesses larger families than D. Ehrenbergianum, which 
are irregularly shaped, seemingly owing to the development of the 
delicate supporting fibre not going on in the same regular manner as in 
the preceding species, and the cells themselves are much larger and 
reniform.”—Archer. 
Plate IX. fig. 2. a, b, plants magnified 400 diam.; ¢, portions show- 
ing filament, 
Dictyospherium constrictum, Archer (Micr. Journ., 1866, p. 128) 
having been afterwards found to produce zygospores (see ** Micro. 
Journ.,” 1875, p. 415), has been transferred to the Desmidee 
in company with Cosmocladium, to which gehus it seems to be 
weoga 
ladium Saxonicum, DeBary, is sometimes placed by 
(as in Rabenhorst’s Algz) in this family. But, as 
/ demonstrated in ‘ Flora” (No. 21, 1865), the cells 
ed in the same manner as in Cosmarium, and therefore its 
er place is with the Conjugate, as one of the Desmidee. 
..v has been found in North Wales. 
Grnus 15. HORMOSPORA. Bred. (1840.) 
Thallus tubular, gelatinous, swimming free. Cells oblong, 
or oval, green, arranged in simple longitudinal series (families), 
either remote from each other, or more or less united at the 
poles. Tegument thick, confluent, contained within the broad 
gelatinous tube, which is either simple or branched. 
* Tubes simple. 
Hormospora mutabilis. Breb. Mem. Fal. 1840. 
Tubes intricate, more or less broad, or parallel and coalescing ; 
cells twice as long as broad, broadly rounded at each end ; 
tegument very thin. 
Size. Cells 011-017 mm., tube diam. -043 mm. (Radh.). 
Rabh. Alg. iii. 48. Breb. in Ann. des Sci. Nat., 1844, t. i. 
f.2. Kirch. Alg. Schl. p. 108. 
In boggy pools. Ireland. 
Plate X. fig. 1. a, portion of filament X 300; 5, same breaking up 
X 300. 
