LICHENS OF THE STATE OF WASHINGTON 23 



black ; paraphyses branched more or less entwining ; asci 4-8-sporeci ; spores 

 hyaline, 1-15-septate. 



1. Lecanactis arnylacea wa.r. megaspora (Merrill) Zahlbr., Cat. Lich. Univ. 

 2:533. 1924. Lecanactis illecebrosa var. megaspora Merrill, Bryol. 

 16:59. 1913. 



Thallus white or grayish white, thin, powdery to granular. Apothecia 

 circular 0.4-1.2 mm. in diameter, adnate; disk brown or black, sometimes 

 white pruinose, flat to convex or umbonate, becoming irregular in shape; 

 proper margin thin, black, more or less persistent; hypothecium brownish 

 black; asci 8-spored; spores hyaline; fusiform, 1-3-septate, 26.4-32 x 

 3.3-4.0 IX. 



On bark : San Juan Co. : Brown Island, 1940, 3256a. Clallam Co. : 

 near Elwha Post Office, 1911, Foster (F) ; Olympic Hot Springs, 2300 ft., 

 \9U, Foster 2885 (F). 



9. THELOTREMACEAE 



Thallus uniformly crustose, little or no differentiation into layers, at- 

 tached to the substratum by hyphal rhizoids. Apothecia circular, single or 

 rarely united in a stroma, immersed or emergent; proper margin well 

 developed and usually surrounded by a thalline one ; asci 1 -8-spored ; spores 

 hyaline or brown, 1 -many-septate, or muriform. 



Alga Trentcpohlia, Phyllactidium, or Heterothallns. 



13. Thelotrema Ach. Meth. Lich. 130. 1803. 



Thallus crustose, partly within the substratum, usually no differentiation 

 into layers. Apothecia small, circular, numerous ; proper margin thin but 

 prominent, thalline margin inconspicuous; hypothecium hyaline; para- 

 physes free, unbranched; asci 1-8-spored; spores hyaline, muriform. 



Alga Trentepohlia. 



1. Thelotrema lepadinum Ach. Meth. Lich. 130. 1803. Lichen lepadinus 

 Ach. Lich. Suec. Prodr. 30. 1798. 



Thallus pale olive-buff (R), cream-buff (R), or various shades of pale 

 gray, smooth to chinky, or areolate, usually thin, sometimes thick. Apo- 

 thecia circular, small, 0.5-1.0 mm., numerous, at first immersed finally 

 emerging like small warts or craters, the same color as the thallus ; disk 

 dark brown or black, white pruinose, partly enclosed, concave to flat ; 

 proper margin prominent, thalline margin thin and inconspicuous ; asci 

 usually 1-4-spored, rarely 8-spored; spores hyaline, ellipsoid-fusiform, 

 muriform, 118.0-126.0 x 13.2-20.0 ix. 



On bark, rarely on moss or rock : Clallam Co. : Elwha River Bridge near 

 Pt. Angeles, 244 ft., 1940, 2863, 2883. Thurston Co. : Gate, 1940, 2957. 

 Kitsap Co. : Hidden Ranch near Bremerton, 213 ft., 1930, 1926. King Co. : 

 Grass Mountain Trail, 2200 ft., 1931, 700. San Juan Co. : San Juan Island, 



