508 nkw and rare freshwater alg^, 



FLAGELLATtE. 

 Fani. HYMENOMONADACE.^-:. 

 Genus 8 y n u r a Ehr. 

 Synuka (GRANULOSA Playf. (PL Ivi., f. 1-3). 



I give another figure of the cells of this species, that in Fi-w. 

 Alg. Lismore, PL xlv., £.3, being shown too finely granulate. The 

 granules are quite coarse, no more than 16 being visible at the 

 edge, round the anterior margin. Home, that T noted lately, had 

 from 1 to 8 minute dark red, or nearly black, irregular granules 

 at the base of the fiagella; or, sometimes, one, larger, simulating 

 a stigma, in the gap between the chloroplasts (PL Ivi., f.2, 3). 

 The chromatophores in this case were a very pale green with(jut 

 any trace of yellowness, and the crenobia peculiar in being oblong 

 (not globose and stellate), with the cells attached round a central 

 peduncle. The origin of these oblong ccenobia becatne clear 

 later, when I found a long cylindrical ccenobium (80/x long by 

 30/x broad, cells long. 12-20, lat. 6-10/x) with a central mucous 

 or membranous peduncle (PL Ivi., f. 1). The latter being gradu- 

 ally drawn apart by the perpetual twisting of the cells, the 

 c<enobium broke up into two oblong colonies. In the same way, 

 these probably break up into smaller groups, which become 

 regularly stellate by cell-division. The formation of the ccenobia 

 in this genus would appear, therefore, to be on somewhat the 

 same lines as in Anthophysa vegetans. 



Genus T e s s e l l a r i a Playf., nom. emend. 

 Cf. Frw. Alg. Lismore, p. 3 15. I find that ^^TesselW^ is pre- 

 occupied by Ehrenberg for a genus of diatoms; I hav^e altered 

 the name of my new genus, therefore, to Tessellaria. 



Tessellaria volvocina Playf. 

 In PL Ivi., f.I, I give a figure of a yellow-green fiagellate evi- 

 dently belonging to this family, which I think is very probably 

 a free zooid of this organism. In shape globose, truncate in 

 front, diam. 10/x, with two long fiagella, two small yellow-green 

 chromatoiDhores confined to the anterior part of the cell, and a 

 number of relatively large refractive globules scattered round 



