SLIME FUNGI— MYXOMYCETES 



313 



classification which has been adopted for these singular 

 organisms, the characters for which are derived from the 

 final and reproductive condition. 



The first of the four orders, into which the entire group is 

 subdivided, is the Peritrichiaceae, in which the wall of the 

 sporangium is not encrusted with lime, and the capillitium is 

 either absent or formed from the wall of the sporangium. 

 This order is again subdivided into two suborders — that of 

 the Tubulinae, in which the wall of the sporangium is not 

 perforated; and the Cribrariae, in which the wall of the 

 sporangium is perforated. 



The principal genus in the Tubulinae is that of Tubulina, 

 in which the sporangia are crowded 

 together so as to form an aethalium, 

 which term is applied to an ag- 

 glomeration of sporangia. The Crib- 

 rariae includes the genera Enteridium, 

 Clathroptychium, Cribraria, and Dic- 

 tydium, in all of which the perforated 

 sporangia are very elegant objects. 

 The subsidiary characteristics of the 

 several genera have reference chiefly 

 to the manner of the perforations. 

 In Cribraria the permanent upper 

 portion of the sporangium forms a 



Cribraria intricate,. 



Fig. 142. — Dictydium, natural 

 size and magnified. 



kind of network (Fig. 141), and in 

 Dictydium the permanent radiating 

 ribs are united by transverse bars 

 (Fig. 142). 



The second order, Columelliferae, 

 with the walls of the sporangium 

 not containing lime, has for its chief 

 character a central columella, from 

 which the capillitium originates. The 

 two suborders into which this group 

 is divided are the Stemoniteae, in 

 which the capillitium springs from 

 every part of an elongated columella, 



and the Lamprodermeae, in which the capillitium springs from 



