200 CHYTRIDIES. 
GENUS 78. OLPIDIUM. Braun. (1856.) 
Cells globose or subglobose, parasitic, epiphytal, or endo- 
phytal, not operculate, nor rooting ; mouth vertical, elongated 
into a cylindrical tube. 
Olpidium endogenum. Brawn Chytrid. No. 20, t. v., f. 21. 
Parasitic in the interior of plants, usually gregarious, de- 
pressedly globose, extended at the apex into a tubular neck, 
which is globosely dilated in the middle ; perforating the mem- 
brane of its host, is extended beyond with a funnel-shaped 
mouth. 
Size. Cells about :024 mm. diam. 
Olpidium intestinum (Braun), Rabh, Alg. Eur, iii., 283. 
Parasitic in Closterium, Vaucheria, &c. 
This appears to be the species figured by Henfrey as occurring within 
the cells of Eremosphera viridis in “ Quart. Journ. Mier. Sci.” vii. (1859), 
t. 8, figs. 11,12. Also by Carter in Spirogyra, in “ Annals of Natural 
History,” 2nd Series, Vol. xvii. (1856), t. 9, figs. 9 and 10. 
Plate LXXX1. fig. 2. Olpidium endogenum parasitic in Clostertum 
lunula X 400. : 
Olpidium ampullaceum. (Braun.) Rabh. Alg. Hur. 111, 282, 
Epiphytal, gregarious, globose, small, sessile, rarely pedicel- 
late, tubular, mouth erect, cylindrical, about as long as the cell, 
terminating in a conical apiculus. 
Size. Cells ‘0065 mm. diam. 
Chytridium ampullaceum, Braun Chytrid., p. 66, t. 5, f. 24-27. 
Parasitic on various alge. 
It was probably this, or a closely-allied species, which was figured by 
Henfrey as parasitic on Eremosphera viridis in “ Quart, Journ. Micr. 
Sci.” vii. (1859), t. 3, £. 18, 14. 
Plate LXXXI. fig. 8. Olpidium ampullaceum parasitic on Mougeotia 
x 400; 8a, individual further magnified. Fig. 4, allied species x 400. 
Genus 79, SYNCHITRIUM. D.By. § Wor. (1863.) 
Thallus multiform. Cells (sporangia of some authors) often 
numerous and aggregated, closely involved in a common mem- 
brane, forming sori, filled with delicately granular orange con- 
tents. Zoogonidia globose, rarely oval or oblong, with a lateral 
orange-red nucleus, bearing a single (rarely 2) very long cilium. 
Inhabiting the substance of plants, with the habit of Ure- 
dines, but without mycelium, 
