240 NEMATOGEN 2. 
Aphanizomenon flos-aque. Ral/s Ann. Nat. Hist. t. 9, f. 6. 
Floating, forming a pale or dark blue green stratum on the 
surface of the water. Trichomes very thin, nearly straight, 
aggregated in membranaceous flakes which readily separate, 
either distinctly or indistinctly articulated, very pale blue or 
colourless. Joints cylindrival, about as long as broad, slightly 
granular. Spores more or less elongated cylindrical, 6-12 times 
as long as broad, granular. 
Sizz. Cells -003-004 mm, diam. Spores ‘005 x 03-04 
mm. 
Allman, Quart. Journ. Micr. Sci. 1855, p. 21, t. 3. 
Byssus flos-aque, Linn. Spec. Plant. (1753) No. 1168. 
Limnochlide flos-aque, Kutz. Tab. Phye. i, t. 91, f. 2, a. 
Aphanizomenon incurvum, Morr. Bull. Brux., 1839, Harv. 
Man. 145, Hass. Alg. 280, t. 76, f. 6. 
Spherozyga flos-aque, Rabh. Alg. Eur. ii., 195. 
In ditches, ponds, and meres. 
One of the species of Alge which contribute to the phenomena cha- 
racterized as ‘‘ breaking of the meres,” Professor Allman thinks that he 
has observed heterocysts (see Micr. Journ. p. 22), but this is not con- 
firmed. 
Plate XCIV. fig. 1. a, Trichomes in bundles, X 200; b, Trichomes, 
with spores X 400. 
GENUS 97. SPHMROZYGA. (4g) Ralfs. (1850) 
Trichomes involved in an amorphous, often very quickly 
diffluent, mucilage, rarely vaginate, agglutinated in an inde- 
finite gelatinous stratum; joints spherical, elliptical or oblong, 
transversely compressed and often quadrangular. Heterocysts 
intercalated, binary, or solitary. Spores originating in cells 
placed on each side of the heterocysts. 
Spherozyga Carmichaeli. Harv. Phyc. Britt. t. 113. 
Stratum thin, of a dark or bluish green colour when recent, 
but opaque and glaucous when dry. Trichomes moniliform, 
with tapering extremities; joints distinct, somewhat quadrate. 
Heterocysts spherical. Spores oblong. 
Size. Cells -0035--0045 mm. Heterocysts -006 mm. diam. 
Spores ‘008-01 x -018-:025 mm. 
Kutz. Tab. Phyc. i.,t. 99, f. 4. Ralfs Ann. Nat. Hist. 1850, 
t. 8, f. 7. Rabb. Alg. Eur. ii., 191. 
Belonia torulosa, Carm. Eng. Fl. v., 379. Harv. Man. 167. 
On damp soil in salt marshes flooded at spring tides, in 
brackish ditches, &c. 
