APIOCYSTIS. 201 



form, but hitherto all efforts failed to detect any such con- 

 nection. The cells divide and redivide, produce resting 

 spores, etc. Different conditions are illustrated. 



Plate CLXVII, fig. 1, a cell in normal condition shedding 

 the outer membrane ; fig. 2, a cell dividing into two ; figs. 

 ,3, 4, a cell divided into eight sister cells, five only visible ; 

 still enclosed in the tegument; figs. 5-11, different condi- 

 * tions of propagation, forming macrogonidia, resting spores, 

 changing color to brownish or red, young forms, etc. 



Genus 66, UBOCOCCUS, Hass. 



Cells large, globose or oblong, reddish or blood-red ; tegument 

 thick, gelatinous, concentrically laniellose Gloeocapsa-like ; stem 

 thick, gelatinous, often ringed or annulate. Edbenhorst. 



Babenhorst properly makes the parenthetical note " Gloeo- 

 copsa-like," because it is to this genus that these so-called 

 Urococcus cells belong. They appear to be merely an occasional 

 condition, arrested development of Gloeocapsa cells; but Gloeo- 

 capsa is an intermediate, or arrested, polymorphous spore con- 

 dition of Sirosiphon ; therefore, Urococcus is a spore condition of 

 Sirosiphon. 



Two of the forms recognized have been named by Hassall as 



UROCOCCUS HOOKERIANUS and UROCOCCUS INSIG-NTS. 



The former is described: "Cells globose, or elliptic, vari- 

 able in size, blood-red, granular, stem more or less elongated, 

 often divided, densely ringed. Cells, 13-60 /*." The latter : 

 U. insignis, u cells larger, globose, blood-red; stem abbrevi- 

 ated, remotely annulated. 7 ' 



Frequent with Sirosiphon and Gloeocapsa, on dripping 

 rocks, mountain ravines, Pennsylvania. 



Plate CXXIII, figs. 11, 12, lateral and polar views of U. 

 insignis; fig. 13, cluster of cells of U. Hookerianus. 



Genus 67, APIOCYSTIS, Naeg. 



Thallus small, vesicular, fixed by a stem-like base. Cells glo- 

 bose, scattered or sometimes eight disposed in a circle ; contents 

 homogeneous, or delicately granulose, with a distinct colorless 

 vacuole ; tegument thick, dissolving into a homogeneous gela 

 tine, cells dividing alternately in all directions. 



Propagation by mobile gonidia, which are globose and fur 

 nished with a pair of vibratile cilia. 



