546 



DESCRIPTIOX OF SPECIES. 



coloration, caused by impreg- 

 nation witli oxide of iron. The 

 threads are distinctly articulated, 

 and ensheathed. The segments are 



set free whed the sheath bursts, 

 and develop into new Jihreads. In 

 other cases the segments remain 

 enclosed, and subdivide into discs, 





Fig. 218.— Ckenothrix Kuhniana. 



a, b, c, d, e. Cocci in various stages o£ fission, x 600. 



/. Zoo^loea of cocci, x 600. 



ff. "Various forms of zooglcea, natural size. 



h. Colony of threads composed of rods grown out of a zooglcea of cocci. 



i — r. Thread-forms ; some straight, others spiral, with more or less differentia- 

 tion between base and apex, [r) is composed of short rods at the base, and above 

 these of cyUndrical segments, and at the apex these segments have divided into 

 cocci, X 600 (Zopf ). 



