(50) 
Mexico (Fendler). Both the lecanorine and pseudo-biatorine conditions 
are well marked. ——P. crossophylla, Tuckerm. (Obs. Lich. 1. ¢. 4, p. 404) 
an elegantly branch-lobed, minute rock-lichen, with bright-reddish, 
pseudo-biatorine apothecia, has only occurred at its original station in 
Vermont (Russell). ——P. granatina (Sommerf.) Th. Fr. (Lecanora, 
Sommerf., Nyl. Scand. Parmelia § Patellaria, Fr. Pyrenopsis, Nyl. 
Lich. Feltm. Th. Fr. Lich. Spitzb.). Granite rocks; Notch of the White 
Mountains (myself) and in Gorham, N. H., (Hd. Willey). Thallus here- 
tofore described as a chinky crust, made up of small, sometimes crenulate 
granules (Sommerf., Fries, Nyl.) or of cartilagineous squamules (Mass., 
Th. Fr.) but really, and in the European specimens (Herb. Th. Fr. Fellm. 
Lich. Arct. n. 4) equally with the American, peltate! and to be compared 
especially with Omphalaria botryosa. From this the plant before us 
appears at once and certainly to differ in its Lecanoreine and not Col- 
lemeine habit; and the details of structure, if they exclude it from the 
Lecanorei, as here understood, permit of its association with Pannaria. 
Iam at any rate unable, in a full comparison, under the microscope, of 
the thalline structure both of this, and of Collema hemaleum, Sommerf., 
referred here as a variety by Th. Fries, with the more reduced conditions 
of P. microphylla, etc., to discriminate any sufficient difference. The 
plant fills in this genus, if our view be not a mistaken one, a strictly 
analogous place to that occupied by L. rubina in Lecanora.——So closely 
related, in every respect, to the lichen just noticed is Pyrenopsis hema- 
topis, Th. Fr. (Collema v. hematopis, Sommerf. Pyr. rufescens, Nyl.) 
found in Greenland (Vahl, e Th. Fr. Lich. Arct.) that its place must 
undoubtedly be determined by that of the former. I have only seen the 
specimens in Fellm. Lich. Arct. (n. 5) which are hardly satisfactory as 
respects condition, but appear to agree generally, in important external 
teatures, with P. granatina. It is to be hoped that the plant may be 
found in New England. —-P. brunnea (Sw.) Mass., known only as an 
United States lichen, on the coast of Massachusetts (Oakes; H. Willey) is 
doubtless more common northward, and is found in Greenland (Vahl, e 
Th. Fr. Lich. Arct.) occurring also in the islands of Behring’s Straits 
(Wright). ——P. cyanolepra, Tuckerm. (Lich. Calif. p.17). On the earth, 
California (Bolander). Closely resembles P. nebulosa (Hoffm.) Nyl., and 
the alleged difference may prove to be insufficient. ——P. leucosticta, 
Tuckerm. (Obs. Lich. 1. c. 4, p. 404) is found throughout the Atlantic and 
Gulf States; and in Ohio (Lesquereux). From this species, first described 
by me in Darlingt. Fl. Cestr. 1853, I am scarcely able to distinguish such 
specimens as I have seen of-the European P. craspedia, Koerb., Parerg. 
p. 45 (Anz. Lich. Langob. n. 429) of Istria and Lombardy. ——P. lepidiota, 
Th. Fr. (Lich. Arct. p. 74. Lecid. muscorum var., Sommerf. P. preter- 
missa, Nyl. Lich. Scand. p. 124, teste ipso, p. 290) was referred by Som- 
merfelt, and Fries to P. muscorum, (Ach.) Del., but differs in its spores, 
and in other respects, and is perhaps nearest to P. leucosticta ; which is 
