VAUCHERIACE&, 125 
6. Vaucheria geminata. (Vauch.) Walz. Jahrb. p. 147, t. 12, f. 7-11. 
Dark or dull green, in dense intricate tufts. Thallus capil- 
lary, tough, dichotomous. Oogonia two (rarely 1 or 8), 
ovate or obovate, opposite, distinctly pedunculate. Antheridia 
intermediate, subulate, more or less recurved. Mature oospore 
spotted with brown, sporoderm colourless, composed of three 
strata. Sporangia on the same or a proper thallus, broadly 
cup-shaped, truncate, and angtilarly horned. 
Size. Oospore °11-"12 x°18-"19 mm. 
DCand. Fl. Fr.ii., 62. Hass. Alg. t. 3,f.1. Cleve Vauch. 
p. 6, f. 4. Kirsch. Alg. Schl. p. 83. Kutz. Tab. Phyce. vi, 
t. 59, f. 8. Eng. Fl. v., 320. Harv. Man. 148. Eng. Bot. 
1, t. 1766, li, t. 2420. Grev. Alg. Britt. p. 198, t. 19. 
Purton Mid. Fl. i, 611. Johnst. Fl. Berw. ii., 252. Grev. 
Fl. Ed. 306. Fil. Devon. ii.,56. Gray Arr. i, 291. 
Ectosperma geminata, Vauch. Conf, 29, t. 2, f. 5. 
Vaucheria Dillwyni, Rabh. Alg. Sachs. No. 1078. 
To this species we also refer the following as synonyms, 
although usually referred to V. sessilis :— 
Vaucheria ovoidea, Hass. Alg. 57, t.5, f. 3. 
Vaucheria ovata, Gray Arr. i., 289. 
Ectosperma ovoidea, Huds. Fl. Ang. 954. Hook. Fl. Scot. 
979. With. Arr. iv., 129. 
In ponds and ditches. 
var, B Yacemosa. 
Oogonia shortly pedunculate, 3 to 5 or more aggregated 
in a corymbose manner. Antheridia single, scarcely longer 
than the oogonia. 
Sizz. Oospore :06-:08 x :075-"08 mm. 
Vaucheria racemosa, Eng. Bot. ii., 126. Grev. Alg. Britt. 
195. Harv. Man. 149. Grev. Fl. Ed. 306. Gray Arr. i, 
292. Hass. Alg. 56,.t. 8, f. 2. 
We have reproduced Hassall’s figure of this form in which the antheri- 
dium is considerably longer than the oogonia. Vaucher says, “This 
species is one of the most common, and is found in nearly all ditches, 
principally in the spring. It is loaded with little bouquets manifest to 
the unassisted sight, and which with the microscope seem to be formed of 
a common peduncle, subdivided into pedicels, each of which carries on 
its summit a spherical body in every way resembling the grains of other 
ectosperms, but nearly half as small again. In the middle of this 
bouquet is the horn, which, without doubt, performs the function of a 
male flower, and which is here but a prolongation of the peduncle. The 
number of grains varies from 5 to 7, but commonly 4 are met with.” 
It is of this species that Hassall says, “It is most frequently infested 
with the curious parasite Cyclops lwpula ot Muller, which occasions the 
growth on the filaments of such extraordinary-looking appendages, in 
the midst of which the parasite resides.” This parasite, whatever it may 
be, was tbe subject of a communication by Mr. A. Lister to the Essex 
Field Club, July 22, 1882, and will be found in the “ Proceedings” of the 
Club (Vol. iii.). 
