196 SIPHOPHYCEA. 
Plate XLVII1., figs. 6-7. Oogonia and antheridia of V. geminata X 
200. Fig. 8, non-sexual spores of the same X 200, after Walz. Fig. 9, 
mature oospore x 200. 
Plate {XLIX., fig. 4, fruiting branch of the variety racemosa, after 
Hassall. 
7. Vaucheria hamata. (Vauch.) Walz. p. 148, t. x11. f. 12-17. 
Aquatic or terrestrial, thallus rather rigid, vaguely branched. 
Oogonia usually single, ovate or ovate-hemispherical, seated 
on a short segment of the divided stem, the other segment 
elongated, curved, forming the antheridium. Mature oospores 
involved in asporoderm formed of four or more strata. 
Cleve Vauch. p. 6. Hassall Alg. t.v.,f. 1. Gray Arr. i., 
289. 
Ectosperma hamata, Vauch. Conf. 26, t. 2, f. 2. Hass. 
Ann. Nat. Hist. xi., p. 439. 
Vaucheria hamulata, Kutz. Tab. Phye. vi, t. 61, f. 2. 
In ditches. 
Vaucher wrote of this species—“TIt differs from all others by the 
manner in which it carries its grains. The peduncles which sustain them 
are much elongated, and they bear at their extremity two little threads, 
the one is recurved and receives the anther, the other is shorter and 
straighter, and carries the grain.” 
Plate XLVIIZ, figs. 10, 11. Oogonia and antheridia of V. hamata X 
200. Figs. 12, 13, mature oospores free from oogonia X 200. Fig. 14, 
sporangium X 200. 
8. Vaucheria terrestris. Lyngb. Hydro. Dan. p. 77, t. 21,f. A. 
Densely interwoven in a thin bright emerald stratum. 
Oogonia usually single, pedunculate, attached by the flattened 
base at the back of the incumbent elongated curved antheri- 
dium. Mature oospores enclosed in a hyaline colourless sporo- 
derm composed of four strata, considerably inflated. 
Eng. Flora v., 820. Grev. Alg. Britt. p.191. Eng. Bot. 
ii, p. 124. Jenner Tunb. Wells, 176. Harv. Man. 148. 
Johnst. F]. Berw. ii., 251. Mack. Hib. 234. Gray Arr. i, 
290. Hass. Alg. 58, t. 5, f. 2. Berk. Glean. t. 9. Walz. 
Jahrb. p. 149, t. xiii, f. 18, 19.  Rabh. Alg. Eur. p. 270. 
Cleve Vauch. 131, f. 1. 
Ectosperma terrestris, Vauch. p. 27, t. 2, f. 3. 
Vaucheria circinata, Kutz. Tab. vi., t. 60, fig. 2. 
Forming patches on damp and clayey soil. 
‘‘ Threads more straight and rigid than in V. Dillwyni, forming a more 
Jax and less interwoven stratum, the summits of the little branches often 
erect, and giving the whole a bristly appearance.” Greville. 
Plate XL1X. figs.1, 2. Oogonium and antheridium of /. terrestris XK 
200. Fig. 3, mature oospore of same, after Walz x 230. 
Plate XLIX., fig.7. Oogonium of V. velutina, Ag. (a marine species), 
after Harvey X 200. 
