DEMATIEI. 



563 



Gen. 201. 



ARTKROBOTRYUra, Cesati. 



Common stem composed of jointed 

 threads ; spores large, radiating, so as 

 to form a little head, dark, septate. — 

 Berk. Outl.p. 3-i2. {Fig. 236.) 



1685. Arthrobotryum atrum. 



B. 4' Br. " Black Arthrobotryum." 



Stem short ; spores large, hyaline at 

 the extremities, unequally articulated. 

 —Ann. N. H. no. 822, t. 9,/. 6. 



On dead nettle stems. Dec. Bath- 



easton. 

 Fig. 236. 

 Minute, stem short, composed of simple, articulated tkreads, which are 

 swollen above, and terminate in subelliptic, very obtuse, unequally articu- 

 lated spores, which are dark in the centre and hyaline at the extremities, 

 (•001--0015 in.) long, exclusive of the swollen base.— 5. d; Br. [.Fig. 236.) 



1686. Arthrobotryum stilboideuxn. Ces. "Dense-headed 



Arthrobotryum.' ' 



Stem elongated ; spores cylindrical, obtuse, three times as long 

 as broad, triseptate. — Cesati. Hedw. t. 4, /. 1. B. ^ Br. Ann. 

 a.II. no. 94:3. A. Broomii. Babh.exs.no. 66. 



On pollard willows. April. 



Spores '0005 in. long, forming a dense St ilhum -like head. 



[A similar, if not identical, species has been found once on a piece of straw 

 from Norfolk, but the spores were only bi-nucleate, 7iot septate, perhaps 

 immature .] 



Gen. 202. 



Fig. 237. 



DENDRYPHIUIVI, Corda. 



Threads free, jointed, simple below, 

 branched above ; branches and branchlets 

 often monilioid ; spores sefjtate, acroge- 

 nous, concatenated. — Berk. Outl.p. 342. 



The spores in this genus sometimes form moni- 

 liform threads, and sometimes exhibit the more 

 usual mode of growth in Septonema. {Fig. 237.) 



1687. Dendryphium comosum. Wallr. 



'• Woolly Dendryphium." 



Tufts indeterminate, black ; stem simple, 

 brown, moniliform above ; spore-bearing 

 threads radiating, simple, or branched, or 



