LICHENS AND FUNGI OF OTAGO, NEW ZEALAND. 443 



and normal apothecia are marked by irregular, flat, brown, superficial maculse, 

 two or three of which generally nearly cover the epithecium (fig. 36). They are 

 scarcely raised above the surface of the epithecium, of which they appear simply a 

 discoloration ; but when moistened and closely examined under the lens, they are 

 found to be the seat of numerous extremely minute (microscopic), brown papillae, 

 which are semi-immersed. These papillseform conceptacles contain, instead 

 of spores, myriads of rod-shaped spermatid, varying in length from '00010" to 

 •00015," and about '00007" broad, borne on the apices of very short, simple, sterig- 

 mata (fig. 38). These conceptacles have externally, save as to colour, the aspect 

 of certain Microthelice (e.g., M. perrugosaria and M. Cargilliana) ; but their 

 contents show them to be spermogones, whose relative sporiferous perithecia re- 

 main yet to be discovered or determined. As regards their sterigmata and sper- 

 matia especially — as well as in other characters — these spermogones do not agree 

 with those of the only species of Abrothallus in which they are yet known to 

 occur* The knowledge we possess of the genus is, however, both fragmentary 

 and unsatisfactory. It does not follow, then, that a difference of character ex- 

 cludes them from the genus ; while, on the other hand, it must be stated as a 

 possibility that they may ultimately prove referable to some other genus or order. 

 The parasitic spermogones in question are, moreover, quite different in all 

 their characters from the spermogones of the genus Usnea or any of its species.f 

 The latter are minute wartlets, of the same colour as the thallus, scattered upon 

 the tips of the ultimate ramuscles, as well as over the apothecial marginal cilia. 

 The sterigmata are much larger, and are compound or articulated ; the spermatia, 

 though also linear, are longer. 



Beneath the brown macula? of the parasite the hymenium of the Usnea has 

 its normal character, striking its usual blue colour with iodine, and the thecse 

 containing the ordinary spores, which are oblong-ellipsoid, or sub-globose ; simple ; 

 colourless ; •0003" long, and '0002" broad ; with or without double contour, accord- 

 ing to age (fig. 43). 



On U. barbata, Fr., var. ceratina, Ach., growing on the branches of trees 

 in Saddlehill Bush. I found both apothecia and thallus infested with various 

 forms of a parasite. 



The one form consists of very minute, black, punctiform, or difform, semi- 

 immersed perithecia, abundantly scattered over the surface of the roughened 

 branchlets (fig. 39 a). In or on some of these I found brown, simple, oblong- 

 ellipsoid spores ; -0003" long, and -0002" broad ; but they are of the same size and 

 form as the normal spores of Usnea, to which they probably really belong, having 



* In A. oxysporus, Tul., as described by myself ("Monograph Abrothallus," p. 33). Tulasne 

 (Mem. 113) described the spermogones as wnknownin the genus. 



f Which are described and figured in my " Mem. Spermog." p. 121, plate i. figs. 1-8. 



VOL. XXIV. PART II. 6 D 



