448 DK LAUDER LINDSAY ON THE 



ray Herb.; exhibits sporiferous perithecia, cephalodia, and difform sterile 

 tubercles and maculae. The perithecia are scattered among the spermogones of 

 the Usnea, and may be confounded therewith, or overlooked among them ; but 

 they are at once distinguished by the brown, 1-septate, figure-8 spores, which 

 agree with those of A. Usnece. The cephalodia resemble those in specimen No. 1 

 (v&r.jlorida), being generally difform-biatorine, or irregularly tuberculated, pro- 

 ducing angularities of the branchlets. They occur also, however, as minute 

 isolated papillae or warts ; sometimes becoming difform or maculaeform ; scattered 

 on the ramules from base to apex of the plant ; sometimes sub-terminal ; 

 generally producing angularities or deformities, like the larger more common 

 forms — always more or less dark brown ; and frequently assuming the aspect of 

 species of Celidium or Phacopsis. These cephalodia are equally abundant and 

 variable also in specimens of var. ceratina from Tasmania (Lawrence), and in 

 U. longissma from Sikkim (Himalayas), both in Herb., Kew. 



5. Var. plicata, Fr., Mauritius; in Herb., Kew; exhibits sporiferous maculae 

 and cephalodia, as variable in character as those described under No. 4. The 

 maculae are brown ; they contain spores irregular as to size and form ; always 

 brown ; sometimes simple and oval ; sometimes 1-septate and figure-8-shaped ; 

 •0004'' to 0008" long, and -0002" broad. The cephalodia are abundant, generally 

 small, wart-like, resembling the apotheciaof Alectoria jubata, Ach., producing, as 

 usual, angularities of the ramules ; occasionally having on their surface brown 

 spores of the character of those of the parasite just described, and evidently refer- 

 able to it. 



6. Var. ceratina (U. barbata, Fr.), Hepp exs. 561. Some of the branchlets 

 exhibit tuberculate, irregular, brown gouty swellings, resembling those produced 

 by the spermogones on Neuropogon melaxanthus, Ach. and N. Taylori, Hook. fil. 

 (Mem. Spermog. plate iv. figs. 9, 10, and 13, 14.) The parasite wholly surrounds 

 the branchlet ; is distinctly limited above and below ; its brown colour is much 

 heightened by moisture ; it has no connection with any forms of either cephalodia 

 or apothecia, but it exhibits no reproductive structure. The whole aspect of the 

 parasite or deformity is Fungoid. In a specimen of U. angulala from New South 

 Wales (also in Hepp's exs. 561), I find simple brown maculae, which sometimes 

 envelope the branchlet, sometimes colour its tip ; but exhibiting no reproductive 

 structure. 



Genus III. Celidium, Tul. Mem. Lich. p. 120 ; plate xiv. figs. 9-13 ; Delisea, Fee ; Plecto- 

 carpon, Fee ; Dothidea, Smrf. pr. p. ; Sphceria, De Not. pr. p. 



The essential character of the genus is the close aggregation of the sporiferous 

 perithecia in round sori or maculae (whence the generic name KtjXiSiov. a macula), 

 with central spermogones, as in Phacopsis. These sori or maculae are blackish- 

 brown; less or more raised above the thallus on which they are parasitic; 



