(17 ) 
as well as respects the true place of Umbilicaria (L. E. p. 348) as espe- 
cially in his consideration, some years later (FV. Scc. 1835) of the transi- 
tion of Cetraria into Parmelia. But important as were these suggestions, 
they remained without fruit; and it was thus left to the writer of this 
(Lich. Calif. 1866) first to give full expression to the view that the Par- 
meliei are, in every respect, immediately contiguous to the Usneei. 
Some of the more obvious points of contact of the two families have 
been noticed already; and all are well known. Borrera, Ach., was made 
up of members of both: and the difficulty which the father of Lichenog- 
raphy found in distinguishing really alien types remained, after Eschweiler 
had emended, and Fries had finally (LZ. H. pp. 75-8) reduced the genus; 
recurring in the emended Evernia as well of Fries as of Eschweiler; and 
perpetuated to this day in Tornabenia, Trev., and Blasteniospora, Trev. 
(Theloschistes Th. Fr.) both of which are still recognized by some as 
Usneet. The even more striking fact that so marked a fruticulose lichen 
as Cetraria tristis is yet in question between Usneei and Parmelia, has 
been considered in its place. And against all this, and the general evi- 
dence from structure, pointing at once to the superior affinity of Sticta to 
Peltigerei, and to the more central and higher place, in the tribe, of the 
latter, as compared with the Parmelici, there is possibly nothing to set, 
beyond a certain superficial resemblance in certain Cetraric, tb Nephroma. 
There is no doubt of this resemblance; especially marked in C. Stracheyi, 
Bab. (Hook. et Thoms. Herb. Ind. Or. n. 2074, 2080. Platysma nephromoi- 
des, Nyl. Enum.) and accompanied in this species also,as in C. leucostigma, 
Lévy. (Sticta Wallichiana, Tayl. Herb. Hook.) and, if I mistake not, in 
C. citrina Tayl. (C. Teysmanni, M. et V.de B. Herb. V. d. Bosch) by 
the surprising anomaly of what appear to be cyphelle; but it sinks into 
insignificance before the generical, and higher differences. 
The centre of the Parmeliei is seen to be Parmelia, of the colourless 
series; filling here the place which is occupied by four genera in the Usneei, 
and offering analogues, we had almost said, to each. From Parmelia devi- 
ates Theloschistes, of the same series, the analogue of Ramalina; while a 
still greater divergence in the same direction is exemplified in Speerschneid- 
era, Which it seems possible to consider as in like relation to Roccella. In 
the brown series, on the other hand, the place corresponding to Thelos- 
chistes is taken by Physcia, the analogue here of Alectoria in the Usneei; 
and finally by Pyxine, an extreme and aberrant type, anticipating, as 
respects the fruit, the similarly exceptional, next succeeding family. 
VIII.—SPEERSCHNEIDERA, Trey. 
Trev., cit. Stizenb., infra. Physcia sect. 2, Tuckerm. Obs. Lich., Ll. ¢. 4, p. 
338. Nyl. Syn. 1, p. 413. Physcia sect. 3, Stizenb. Beitr. L ¢. p. 173- 
Apothecia scutelleformia. Spore ex ellipsoideo oblonge 1. dac- 
3 
