28 Cincinnati Society of Natural History. 



III. TRICHIA, Haller. Sporangia regular and stipitate or 

 sessile and somewhat irregular; the wall, at maturity, irreg- 

 ularly ruptured. The stipe more or less elongated or often 

 wanting, usually resting on a hypothallus. Capillitium con- 

 sisting of numerous short slender tubules, called elaters, inter- 

 mingled with the spores and wholly free; elaters simple or 

 rarely branched a time or two, each extremity terminating in 

 a smooth tapering point; the spiral ridges parallel and con- 

 spicuous, 2-5 in number, smooth or spinulose. Spores globose, 

 yellow, ochraceous, olivaceous. 



The genus Trichia is unique among the Myxomycetes in 

 having its capillitium composed of tubules, which are entirely 

 free from the wall of the sporangium. The length of these 

 free tubes varies usually between .3 mm. and .5 mm., being 

 sometimes shorter, but seldom longer; they are typically 

 cylindric, or equally thickened from end to end, or quite 

 rarely they are thickened in the middle, and taper gradually to 

 each extremity ; the extremities terminate in a smooth taper- 

 ing point, straight or sometimes a little curved or flexuous, 

 which maintains an average length in each species. The 

 spiral ridges wind around the thread almost invariably to the 

 left, or with the hands of a watch ; the}' are always more or 

 less prominent and conspicuous, and usually maintain a 

 regular curve and uniform interval between each other in the 

 same species; their surface is either smooth, or sometimes it is 

 invested with minute w^arts or spinules. 



In all the species of this genus, however, irregular and 

 abnormal elaters are occasionally met with among the typical 

 ones. As these abnormal forms always arrest attention, and 

 have been conceived to possess specific value, it maj' be well 

 to note the principal of them. 



1. The elater is sometimes branched. In two or three 

 species the branching appears to be quite regular and not 

 abnormal ; still, even in these species, most of the elaters in 

 the sporangia are not branched. In some cases the branching 

 arises from confluence of two or more elaters. 



2. Ellipsoidal swellings, or enlargements of the elater, 

 sometimes occur, at one or both extremities, or at points 

 intermediate between them ; these always occur irregularly, 

 and are essentially abnormal. 



