76 HERRE 



their tips enlarged, brown; spores 4 — 8 in the asci, variously 



1- J 10 ~ 15-5 

 shaped, ^-^ n, 



26 — 41.5 



Abundant throughout; occurring on various kinds of rocks, earth, 

 the bases of old tree trunks, and the thallus of Cladonia pyxidata. 



When the thallus is thick, soft, and crumbly or mealy, it forms the 

 variety or species gypsacea of various authors. When it is on Cla- 

 donias and mosses it is the subspecies bryophila; sometimes in this 

 habitat it grows without a thallus and is then variety parasitica 

 Sommerf. 



All of these variations occur with us, as well as some others, but 

 none of them depart widely enough from the average form to merit 

 special description. Several varietal forms may be secured from 

 one extensively spreading patch covering an irregular rock mass, 

 where different conditions of light and moisture may affect the 

 growth of different portions of the thallus. 



Widely distributed in both the north and the south temperate zones. 



2. DIPLOSCHISTES ACTINOSTOMUS (Pers.) A.Zahlbr. 



Urceolaria actinostoma Persoon, in Ach. Lich. Univ. 288. 18 10. 

 Urceolaria actinostoma Tuck. Syn. North Am. Lich. I: 222. 1882. 

 Diploschistes actinostomus A. Zahlbr. Ascolichenes, 122. 1907. 



Thallus of smooth, thick, closely compacted, angular or difform 

 areoles separated by deep cracks and fissures; the whole forming a 

 dense, determinate, suborbicular crust; rarely the crust is thin and 

 indeterminate; color whitish, gray, mouse-colored, dusky, and in one 

 specimen collected, black; the margin usually much paler and a 

 white hypo thallus more or less evident; KOH — ; CaCl202 faint 

 reddish. 



Apothecia numerous, immersed, very small, opening at the surface 

 by a minute pore, which is surrounded by an at length fully visible, 

 radiately striate or stellate proper margin; said by authors to be gray 

 pruinose, but not so with us; epithecium deep blackish-brown; para- 

 physes thread-like, densely entangled; spores 3, 4, and 8 in the asci, 

 variously disposed, ovoid to broadly ellipsoid, from colorless turning 

 dusky with age, then dark brown and much shrunken and misshapen; 

 12 — It; 



• ^~ PL. 



18 — 26.9 



