132 DR LAUDER LINDSAY ON THE SPERMOGONES AND PYCNIDES 
some resemblance, in its general aspect, to Neuwropogon melaxanthus. < Lying 
without adhesion,” says TwrEpIE, apparently, of this curious lichen (in Herb. 
Hook.), “ on laxe sands at Iquique, Peru, 2-3000 feet, where clouds often hang. 
Tint to sand green from adistance. One other minute yellow lichen on old bones, 
and a cactus on lofty rocks on the coast. No other plant on coast for 14 leagues 
inward, and then three only on the west mountains!” 
Specimen 2.—Var. gracilior, Nyl. (Syn. Usnea tumidula, Nyl.); Coquimbo, 
Cuminc; in Herb. Hooker, Kew. Its segments are round, narrow, and fili- 
form, and the whole plant has the aspect of &. calicaris, var. canaliculata, Fr., 
or of &. linearis. The spermogones are large, black, round superficial bodies, 
sparingly scattered about the ends of the ramules. This specimen also bear 
apothecia. 
GENUS II. Durourga, Ach., Nyl. 
In this genus the spermogones are minute, black, punctiform, immersed, 
scattered about the angles of the erect thallus. The black points indicate the 
ostioles, which lead to the immersed body of the organ ; they vary greatly in size, 
and are generally flattish, though sometimes papilleform. The spermogones, ex- 
ternally, closely resemble those of Roccella. As in Ramalina, the sterigmata are 
short, simple, linear cells; but they are much more irregular in outline, and are 
generally of greater diameter; they are generally similarly sub-ramose at base. 
Their length varies from xath to sath long. But, unlike Ramalina, there are no 
elongated, anastomosing, sterile filaments intermixed. The spermatia also differ 
remarkably from those of Ramalina. They are linear, long, and slender, about 
sooth long, andslightly curved. 
Species 1. D. madreporiformis, Ach. 
Specimen 1.—Switzerland; in Herb. Hooker, Kew. The angles about the ends 
of the ramules are dotted over with the minute black points which mark the 
ostioles, and which become brown when moistened. The spermatia are about 
sooth long, with a breadth of ;;;ath; they are very slender and beautiful, straight, 
or more generally slightly curved. The sterigmata are irregular dilatations of 
simple cells, or digitate prolongations of basal tubes. Sometimes, though rarely, 
they are composed of two or more simple irregular cells or articulations. In 
general they resemble those of Lecanora subfusca. 
Specimen 2.—ScHLEIcHER exs., No. 67, 1814 (sub Lichen madreporiformis, 
Wutrr. Hatu., No. 1962); on top of Mount Letscherberg; in Herb. Hooker, Kew. 
The spermogones occupy the position they do in Sphwrophoron compressum, than 
whose spermogones, however, they are larger and not so crowded. They are 
generally scattered in groups of two or three together, near, but not on, the apices 
of the segments of the thallus. There are no spermogones in the specimen in 
Scu#RER’s exs. in Herb. Hooker. I have not met with apothecia on any speci- 

