44 HERRE 



KEY TO SPECIES. 



Thallus of flat or flattish adnate squamules. 



Perithecium black; thallus more or less olive or blackish brown; on 



bark i. squameella 



Perithecium clear; squamules more or less reddish or chestnut brown; 



on earth 2. hepaticum 



Thallus foliaceous, umbilicate. 



One-leaved, large 3. minatum 



More or less polyphyllous 



The convolute, complicate lobes ascendant, the plant more or less 



cespitose 4. miniatum complicatum 



Thallus pseudo-crustaceous, small, closely appressed. 



5. aquaticum 



Section CATOPYRENIUM. 



Thallus squamulose; or minutely foliaceous, but not umbilicate; 

 perithecium black. 



i. DERMATOCARPON SQUAMEELLA (NyL). 



Verrucaria squameella Nyl. in litt. to Dr. Hasse. 1897. 



Thallus foliaceous, small to minute, irregularly lobate, with uneven, 

 undulate surface; the more or less upturned margin crenate, some- 

 times minutely orbicular-lobulate fringed; color dark olive or reddish 

 brown to blackish; beneath whitish or pale, fastened to the substratum 

 by numerous rhizoids. 



Apothecia rather numerous, immersed, minute, pear-shaped or 

 subglobose, the perithecium entire, dark brown or blackish; asci 

 clavate to short ventricose; hymenial gelatine vinous red with I, but 

 when KOH is applied first and then I the reaction is a quickly fading 



blue; spores narrowly ellipsoid, 5 ; 1L " Nyl. in 



i2j - 17} 15 - 18 



litt. 



Very rare; collected but once, on the bark of Quercus lobata, in the 

 foothills 5 miles south of Stanford University. Originally collected by 

 Dr. Hasse near Los Angeles, where it is also very rare. 



Section ENDOPYRENIUM. 



Thallus of adnate squamules or sub-foliaceous, but not umbilicate; 

 perithecium clear. 



