No. 625] HYBRIDS AMONG SPECIES OF SPIROGTBA 111 



The sporiferous cell is usually inflated on the eonjus?atinj? 

 side and the spores are frequently placed obliquely. In 

 conju^^-ating filaments cells that fail to mate usually be- 

 come oTcatly distended. The spores arc ('llipM)id. 40 m 

 X 5(>-100/x (Fig. 1). This species i^ lii-liK xnilal.N', hut 



I have examined many collections containing it and have 

 seen none that resemble the hybrids. 



typical filaments others with the characters of varians, 



