THE FAUNA OF BOULDER COUNTY 235 



(29) Reticularia Bulliard. Persistent portion of sporangium walls rusty brown, 

 forming broad folds and strands, as though frayed out. R. lycoperdon Bull. Not 

 definitely reported by Sturgis from our district, but he writes: "This species 

 appears to be common throughout the state, and often attains a very large size, 

 four to five inches in diameter. It occurs frequently on decorticated portions 

 of living trees and, with its silvery-white cortex, forms a very conspicuous object." 

 The aethalium is more or less convex. Spores pale rusty brown, closely reticulate 

 on one side. Mr. E. Bethel writes me that he has found it not infrequent in 

 Boulder County, on decorticated conifers and occasionally on poplars. 

 Reticularia Bulliard (1791) has long priority over Reticularia McCoy (1844) in 

 Brachiopoda. 



Order LYCOGALACE^E 



Sporangia forming an aethalium; pseudocapillitium consisting of branched color- 

 less tubes (Lister). 



Family LYCOGALID^ 



(30) Lycogala Micheli. ^thalia subglobose or subpyriform, with a cortex con- 

 sisting of two or more closely combined layers, provided with cell-like vesicles; 

 spores in mass pale pinkish-grey. L. flavofuscum (Ehr.), sethalia subpyriform, 

 brown, smooth. 



L. epidendrum (L.) is not specifically reported by Sturgis from our district, but is 

 said to be "the commonest of all myxomycetes everywhere." It has the cortex 

 minutely roughened or warted. Mr. E. Bethel tells me that he has found it very 

 common about Boulder. 



Order TRICHIACEjE 



Capillitium consisting of free tubular threads (elaters), or a network branching at 

 wide angles, with thickening in the form of spirals or rings. 



Family TRICHIIDiE 



(31) Trichia Haller. Capillitium of free elaters. T. coniorla Rost., var. incon- 

 spicua Rost.; T. varia (Pers.). The elaters have a fine spiral sculpture. The 

 sporangia in our species are sessile. 



(32) Hemitrichia Rostafinski. Capillitium combined into a net, the threads with 

 spiral bands. H. clavata (Pers.). In a variety collected by Mr. Bethel at Boulder 

 the threads of the capillitium, instead of being spirally banded, are minutely and 

 densely spinulose (Sturgis). The sporangia are ochraceous-yellow. 



Order ARCYRIACE^ 



Capillitium a network of tubular threads branching at wide angles and thickened 

 with cogs, half-rings, spines or warts. 



Family ARCYRIID^ 

 Capillitium elastic. 



(33) Arcyria Hill. Sporangia stalked, walls evanescent. A. incarnata Pers. 

 (sporangia flesh-color, crowded, stalks short); A. pomiformis (Leers) (sporangia 



