374 HERRE 



4. PELTIGERA CANINA MEMBRANACEA (Ach.) 



Nyl. 



Thallus very thin and papery, becoming greatly expanded, 

 the surface smooth and more or less pitted and furrowed. 

 Lobes large, dilated, rounded, irregularly crenate and lacini- 

 ate, more or less imbricate, often forming mats several layers 

 in thickness ; tips of lobes often visibly tomentose ; color and 

 under surface as in typical form. Apothecia numerous, margi- 

 nal or terminal on somewhat narrowed and extended lobules. 



Occurring throughout with the type on mossy tree trunks and 

 on earth and stones. 



Pcltidea canina membj'anacea Ach. Lich. Univ. 518. 1810. 

 Pcltigera canina membranacea Nyl. Syn. Meth. Lich. i : 324. 



i860. 



Xin. Endocarpiscum Nylander. 



Thallus quite small, one-leaved, umbilicate. Apothecia im- 

 mersed, indicated only by an ostiole, or superficial, lecanorine. 

 Spores numerous, very minute, simple, colorless. 

 Endocarpiscum Nylander, Flora 47 : 487. 1864. 



I. ENDOCARPISCUM GUEPINI (Moug.) Nyl. 



Thallus small to very small, one-leaved, umbilicate, ap- 

 pressed, rounded, scattered or crowded and imbricate ; the 

 sinuous, crenate, upturned margin bluish sorediate ; color 

 brownish olive to gray ; beneath naked, smooth, wrinkled, 

 flesh-color, brown, or even blackening. Apothecia deeply im- 

 bedded in tiny pits, invisible to the naked eye ; sometimes be- 

 coming superficial, lecanorine, black. Spores very small, 

 numerous, simple, colorless. 



Abundant in the foothills at moderate elevations and on cliffs 

 above the ocean. An inconspicuous plant easily overlooked ; 

 readily recognized by the blue sorediate margin. 



For the present I follow Tuckerman's classification of this 

 lichen ; Dr. Zahlbruckner places it in the genus Hcppia. 

 Ji7idocarpo7t guepini yioug. Fr. Lich. Eur. 410. 1831. 

 Endocarpiscum guepini ^y\. YXoYH ^^ : 487. 1864. 



