W. O. Stiirgis — Type- Specimens of Myxomycetes. 485 



appear to be rather developmental than specific. The character of 

 the elaters in the Trichiacece, useful as it undoubtedly is as indicative 

 of generic and even specific lines of demarcation, nevertheless can 

 hardly be regarded as very stable. Species of Hemitrichia occasion- 

 ally show the free elaters characteristic of the genus Trichia, and on 

 the other hand forms normally provided with free elaters are some- 

 times found with the elaters combined into a network. Within the 

 limits of a single species, or even of a single specimen, great variety 

 in the markings of the elaters is often seen. In the small specimen 

 of T. reniformis, Pk., which we are considering, some of the elaters 

 are almost exactly like those of OUgonema, while others are long, 

 well-developed, and show perfectly even and distinct spirals, ap- 

 proaching very closely in this respect Rostafinski's T. inconspicua. 

 It does not seem advisable therefore, merely on the ground of varia- 

 tions in the character of the elaters, to distinguish, as separate 

 species, forms otherwise so nearly identical as the three above men- 

 tioned, and I can but regard Trichia reniformis, Pk. [T. contorta, 

 Rost., var. genuina, List.), T. incons2ncuq, Rost., and T. loioensis, 

 Macbr., as varieties of a single species characterized by sessile, sub- 

 globose or somewhat elongated sporangia, of a dark reddish or pur- 

 jilish-brown color, and provided with warted spores. 



Oligonema flavidum, Pk. (Ferichce?ia flavida,Yk.),}iep. XXVI, 

 p. 76, 1873, and Rep. XXXI, p. 57, 1878. The genus Oligonema 

 l^resents serious difficulties to the systematist, by reason of the varied 

 and intergrading characters exhibited not only in different gather- 

 ings, but often in different portions of the same gathering. The 

 type-specimen of the present species presents the following char- 

 acters : 



Sporangia densely aggregated in small, effused clusters, occasion- 

 ally superimposed, 0.4-0.6™™ in diameter, globose or slightly elon- 

 gated, sometimes cylindrical, clear golden yellow, shiny, smooth, 

 or wrinkled above. Wall membranous, pale yellow ; inner surface 

 minutely and densely punctate. Elaters scanty, simple or sparingly 

 branched, 52-243/x long, irregularly cylindrical, with occasional 

 bulbous swellings, short blunt spines, and minute warts, the whole 

 surface very minutely and densely spinulose or punctate, tips rounded 

 or bluntly pointed. Spores yellow, 13-15yu, in diameter,* the surface 

 marked with narrow, raised bands forming an almost complete net- 

 work. (PI. LXI, figs. 23 & 24.) 



* The measurements of the spores, in this and the following cases, include the 

 spore-border. 



