366 PROCEEDINGS OF THE ACADEMY OF [1893. 



The peculiar spore wartiug of A. magna can be found with a high 

 degree of amplification in A. punicea, A. mitans and several other 

 species of the eu-arcyrise. It may practically be considered the type 

 of the spore-sculpturing of that section of the genus. 



Trichia pulchella n. sp. 



Sporangia substipitate or sessile with a narrow base, globose, 

 averaging *6 mm. in diameter, bright vitelline yellow, growing either 

 singly or in small scattered clumps containing but few sporangia, 

 but not upon a common hypothallus ; sporangium-wall clear, trans- 

 lucent, rupturing irregularly at the top ; capillitium and spores 

 vitelline yellow in mass; capillitium composed of cylindrical 

 threads 3"5-4'5,a in diameter, terminating in pointed ends from one 

 to one and one half times the diameter of the thread in length ; 

 spirals three to four in number, winding more or less irregularly ; 

 interspiral filaments absent or very rudimentary; threads occasion- 

 ally branched and having occasionally bulbous expansions in their 

 course; spores 11 to 12'5,u in diameter; epispores provided with a 

 sculptured reticulation composed of very narrow rounded thread-like 

 raised bands combined into more or less broken polygons numbering 

 from five to seven to the entire epispore. 



Adirondack Mts., N. Y.— Chestnut Hill, Philadelphia, Pa. 



This species is allied to the group of Trichias of which T. chryso- 

 sperma may be said to be the central form. It differs from them all 

 however, in the solitary or individual habit of growth of the spor- 

 angia, which are not developed on a common hypothallus, and in 

 the absence of interspiral ridges even under high amplification. 



The very delicate thread-like character of the reticulations of the 

 epispores is remarkable. The threads forming the sides of the 

 polygons are sometimes simple, sometimes zigzag or broken in out- 

 line enclosing minute rhombic interspaces, or sometimes marked by 

 a row of rudimentary pits like those often found in the epispores of 

 T. chrysosperma. The spores of the two gatherings from which the 

 species is described are identical, but the capillitium varies, being 

 more bulbous and irregular in one gathering than in the other, due 

 to the fact that it was developed in colder weather. In neither of 

 the specimens could the sporangia be said to be stipitate, but the 

 character of the dark plasmodic bases of the few subsessile sporangia, 

 warrants the belief that under specially favorable conditions, stipit- 

 ate sporangia may be developed analogous to those of the neighbor- 

 ing species T. varia, var. nigripes. 



