HYMENODECTON. 



251 



3. Graphis serpentina. Lirellae immersed, slender, of 

 same width throughout, extremities obtuse : thalamium ca- 

 naliculate, naked, or pruinose. Spores linear, margined, 

 rounded at the ends ; each containing eight to ten trans- 

 versely-oval, margined, yellow cellules. (E. B. 1755, var. 

 eutypa; 2301, var. rectal) 



Genus III. HYMENODECTON, LeigM. 



Gen. Char. Apothecium lirellate, immersed. Perithecium a 

 very thin, black, cartilaginous membrane, surrounding sides and 

 base of thalamium, which is broad, plane, having a very slender 

 proper margin and an accessory thalline margin. Thallus crusta- 

 ceous or membranaceous. (Name from vfirjv, a membrane, and 

 Scktlkos, fitted to receive, in allusion to the structure of the peri- 

 thecium.) 



1. Hymenodeoton dendeiticum (8ev$pov, a tree). Thal- 

 lus tartareous, pulverulent, determinate; lirellae branched 

 in a pedate-radiate manner ; thalline margin prominent, ru- 

 gose. Thalamium plane, dilated, pruinose. Spores linear, 

 margined, rounded at ends, each containing about eight 

 transversely -oval, margined cellules. (E. B. 1756, var. 

 Smithii.) 



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