THAMNOMYCES FUCIFORMIS (Fig. 852).--In general appearance, this is the same as Thamnomyces chordalis, but a much larger plant. The fruit bodies (perithecia?) are more slender and are short, stalked. Our figure, which is about half the spike, will show exactly the difference between the two species. The plant was named by Berkeley from specimens collected in Brazil by Spruce, and to this day is only known from this old collection. The name is from the habits, "those of a fucus rather than a fungus," a far-fetched comparison, for my impression is there are no fuci that are carbonous, or have much resemblance to this plant. RELATED PLANTS. The following plants are compiled in the section Thamnomyces in Saccardo. None of them are true Thamnomyces, and most of them could go into Fries' genera Rhizomorpha. I do not believe, however, it is possible to keep Rhizomorpha separate from Xylaria. The type species Xylaria setosa is quite different from the normal type of Xylarias in having entirely carbonous, filiform stems and superficial perithecia, but both of these features merge into Xylaria through so many intermediate species that there is no drawing the line of demarcation. [Illustration: #Fig. 853.#] XYLARIA SETOSA (Fig. 853).--Stem densely fasciculate, filiform, black, entirely carbonous. Perithecia ovate, sparse, rarely developed. Spores (teste Fuckel), ovoid, dark, 10 x 16 mic. This is a rare plant in Europe, growing on old sacks, matting, carpets, and similar refuse. It is generally found in cellars. I think it is not known on wood nor recorded in the United States. It resembles carbonized horse hair and was called "horse hair usnea" by old Dillenius. Our photograph of the specimen at Kew will give a good idea of it, although from the account it grows erect, and is not matted. Both Bulliard and Sowerby gave characteristic figures, both from plants growing in cellars, on old mats. It has had a great number of names, and is recorded in Saccardo as Xylaria hippotrichoides, the specific name proposed by Sowerby and used by Persoon. Some very recent juggler, I have forgotten who, dug up the old name setosa, which I adopt as being less cumbersome. Occasionally these jugglers do propose some improvement in names, and I believe in encouraging them, when their wonderful date dictionary discoveries are really better names. Saccardo gives the following synonyms: Sphaeria hippotrichoides, Ceratonema hippotrichoides, Hypoxylon loculiferum, Rhizomorpha tuberculosa, Cryptothamnium usneaeforme, Rhizomorpha setiformis, Chaenocarpus setosus, Chaenocarpus Simonini. The date expert must have had quite a job. Xylaria adnata as described by Fuckel (Rhizomorpha adnata), and unknown to me, is evidently very similar to the preceding plant, but grows closely adnate to rotten beech wood. Xylaria fragilis (Rhizomorpha fragilis) is imperfectly known from old records in Europe. It is probably same as above.