arcyria] arcyriaceae 235 



lation and spinules on the other part ; there are numerous free branches 

 with clavate or pointed ends ; except that the spines are more 

 developed than usual, the markings do not differ from those frequently 

 seen in typical A. ferruginea, of which it must be considered a form. 

 The type of Heterotrichia Gabriellae Mass, from South Carolina (K. 

 838), has numerous pointed free ends in the upper part of the net 

 of the capillitium ; the threads are flattened, very closely reticulate 

 and spinulose, and in many places thickened on one side ; the spores 

 measure 10 to 11 fi. A similar form has been met with repeatedly in 

 the British Isles when the conditions of development have not been 

 entirely favourable ; free ends are usually abundant in sporangia 

 that have matured in cold weather. As this variety is not 

 unfrequent, for convenience of reference we follow Dr. Torrend in 

 distinguishing it as var. Heterotrichia. An abnormal form of 

 A. ferruginea was found by Prof. Schinz near Goldau, Switzerland, 

 in September, 1902 (B.M. slide) ; the sporangia are very shortly 

 stalked or sessile, the slender capillitium threads measure 2 - 5 to 3 [t. 

 diam., and are beaded at short intervals with globular or ovoid 

 swellings, 10 /x thick, which are marked with . a close reticulation of 

 raised bands ; the threads between the swellings are nearly smooth ; 

 the spores average 10 to 12 //, but there are also many monstrous 

 and irregular spores. It is not unusual to find globular expansions 

 in the threads of more normal developments, but this gathering is 

 interesting from their great abundance. 



Hob. On dead wood. Frequent in the British Isles. — Leytonstone, 

 Essex (B.M. 1493) ; Lyme Regis, Dorset (B.M. slide) ; Leighton, 

 Beds (B.M. 1492) ; Hampstead Park, Birmingham (B.M. 1494) ; 

 Broseley, Salop (B.M. 3014) ; Scarborough (B.M. 3015) ; Alnwick 

 (B.M. 3023); Anglesea (B.M. 1130); Mid-Lothian (B.M. 3016); 

 France (K. 921) ; Germany (B.M. 727) ; Norway (Christiania Herb.) ; 

 Sweden (B.M. 3017) ; Bohemia (B.M. 3018) ; Switzerland (B.M. 3019) ; 

 Portugal (B.M. 3020); German East Africa (B.M. 3021); Ceylon 

 (Peradeniya Herb.) ; Australia (K. 848) ; New Zealand (B.M. 3022) ; 

 Banff, Canada (B.M. 3024) ; Washington State (B.M. 3025) ; Maine, 

 U.S.A. (B.M. 1627) ; Massachusetts (B.M. slide) ; South Carolina 

 (B.M. 966). 



2. A. versicolor Phillips in Grev., v. 115 (1877). Plas- 

 modium ? Total height 2-5 to 3 mm. Sporangia shortly 

 stalked or sessile, gregarious, pyriform or clavate, 1 to 2 mm. 

 diam., more or less shining, yellow or olivaceous-yellow ; 

 sporangium-wall membranous, persistent except at the apex, 

 yellow, papillose on the inner side. Stalk membranous, 

 0*2 mm. long, yellow-brown, filled with spore-like cells, arising 

 from a well-developed hypothallus. Capillitium an elastic 

 network of freely branching yellow threads, 4 to 6/t diam., 

 triangular or oval in section, either uniformly spinulose and 

 marked with broken reticulation, or with one side thickened and 

 marked with transverse bars ; the threads arise from the tube 

 of the stalk, and are not attached to the sporangium- wall ; 

 free ends shortly pointed. Spores yellow, smooth, 8 to 10 yu. 

 diam. — Mass. Mon., 149. Arcyria vitellina Phill., I.e. ; Macbr. 

 N. Am. Slime-Moulds, 192. 



