—93— 



New by name to the United States. 

 Lecidea (Rhizocarpon) alboatra var. epipolia (Ach.) Schaer. Enum. p. 122.. 

 1850. 



Thallus whitish, friable and areolate, firm and rimulose, or continuous and 

 unmarked, effuse or limited, destitute of hypothallus in the American speci- 

 mens examined. Apothecia small, more or less immersed, plane with a thin 

 margin or convex and immarginate, disk black, sometimes bluish or whitish- 

 pruinose. Spores 8, ellipsoid, from one varying to three-septate, and sub- 

 muriform, 18-22 x 7-1 1 /jl, nearly colorless or brown, hypothecium brown, para- 

 physes distinct, tips clavate and blackish-brown. 



On calciferous conglomerate, near the tide water, No. Haven. 



The var. b. saxicola Fr. is little different, but our plant is without hypothallus. 

 Lecidea (Rhizocarpon) eupetraea Nyl. Flora 1870, p. 36. 



Thallus limited or effuse, granulate-verruculose, thin, the black hypothallus 

 here and there visible, ashy or ashy-fuscous, K + > dark rusty-red. Apothecia 

 rather small, scattered, commonly slightly convex with a thin persistent margin, 

 black. Spores oblong-ellipsoid, fuscescent or decolorate, apparently without 

 halo, muriform, septa irregular, 20-25 x 10-14 /j, hypothecium dark-brown, 

 paraphyses and asci gelatinous, epithecium infuscate. 



On fragmental stones on earth, and rocks of walls, Rockport. 



Nylander compares this species externally to L. petraea, and Hue, in Ad- 

 denda, to L. parapetraea. It is unlike the common states of L. confervoides 

 from this region in color and conditioning of the thallus, but is analogous in 

 color and granulated crust to one form of L. concentrica. The species is reported 

 from Miquelon, Hue; and from Labrador, Arnold. In Eckfeldt's Newfound- 

 land and Labrador list it is noted as L. empetraea, and in Macoun's Canadian 

 list the spelling is again incorrect. New to the United States. 

 Lecidea {Rhizocarpon) confervoides forma dispersa (Leight.) comb. nov. 



L. petraea f. dispersa Leight. Lich. Fl. G. Brit. Ed. Ill, p. 376. 



On ledges, Rockport. 



Hypothallus conspicuous, the thalline areolae scattered and ashy, Apothe- 

 cia seated on the hypothallus, L. conjervoides is in part Buellia petraea of Tuck- 

 erman's Synopsis. Unnoticed in American lists. 



Lecidea {Rhizocarpon) obscurata (Ach.) Schaer. Spiclg. p. 130. 1828. 



Thallus grayish, thin, areolate, the areolae small and never discrete in oui 

 specimens, plane, K -+- faint, C — hypothallus black but not always visible. 

 Apothecia small to medium, innate-sessile, plane or slightly concave, disk black 

 with a rather thickened obtuse margin. Spores variable in number, oblong 

 ellipsoid, colorless or fuscescent, muriform, halonate, 26-45 ^ 13-20 n, hypothec- 

 ium gel. with 1 H- deep blue. 



On rocks in bed of a stream, but mostly about its margins, Camden. 



A curious feature of the Knox Co. specimens is the often concentrical ar 

 rangement of the apothecia, exactly in the manner of L. concentrica. 



The plant is noticed in Macoun's Canadian list, and in the Newfoundland 

 catalogue of Eckfeldt, Dr, Fink records it from Minnesota, but I find no other 

 record for the United States. 



