204 THE NORTH AMERICAN SLIME-MOULDS 



rupture of the pcridfum, in typical cases at the apex, its walls remain- 

 ing then otherwise entire; capillitial threads in No. 3, only. 



Key to the Genera of the Tubiferaceae 



A. Spores olivaceous; sporangia in one or several series, 1. Lindbladia 



B. Spores umber; sporangia in a single series ... 2. TuBlFERA 



C. Sporangia stipitate; capillitium of tubular threads . 3. Alwisia 



1. Lindbladia Fries 



1849. Lindbladia Fries, Sum. Veg. Scand., p. 449. 



Fructification aethalioid ; the sporangia short, tubular, sometimes 

 superimposed, sometimes forming a simple stratum, in the latter case 

 generally sessile, but sometimes short-stipitate, the peridium at first 

 entire, at length opening irregularly either at the sides or apex, beset 

 with granules; spores olivaceous. 



This genus was established by Fries in 1849 to accommodate a 

 single species of wide distribution and somewhat varying habit, which 

 is neither a tubifera nor yet a cribraria and offers points of resem- 

 blance to each. It is distinct in that the sporangia, while often in 

 single series, are yet often superimposed. It resembles Tubifera in 

 its simple sporangia, opening without the aid of a net; it is like 

 Cribraria in the smooth ochraceous-olivaceous spores and granulifer- 

 ous peridium. 



1. Lindbladia effusa (Ehr.) Rost. 



Plate I., Figs. 3, 3 a, Plate XII., Figs, 1, 2. 



1818. Licea effusa Ehr., Syh. Myc. Ber., p. 26. 



1875. Lindbladia effusa (Ehr.) Rost., Mon., p. 223. 



1879. Perichaena caespitosa Peck., Rep. N. Y. Mus.. XXXI., p. 57. 



Sporangia minute, either closely combined and superimposed, so as 

 to form a pulvinate aethalium, or crowded together in a single layer, 

 sessile, or short-stipitate; the peridia thin, membranous, marked by 

 scattered plasmodic granules, often lustrous, sometimes dull lead- 

 colored or blackish, especially above ; stipe, when present, very short 

 but distinct, brown, rugulose; hypothallus well developed, membra- 

 nous, or more or less spongiose in structure; spore-mass ochraceous, 

 under the lens, nearly smooth, almost colorless, 6-7.5 /x. 



