50 COCCOPHYCE.E. 



FAMILY III. VOLVOCINBJS. 



Ccenobia mobile, globose, subglobose, or quadrangular and 

 flattened, produced from agile biciliate green cells, with a double 

 contractile vesicle. Common tegument of the ccenobiuin hya- 

 line, more or less ample. 



Propagation sexual or asexual. The sexual monascoius or 

 di&cious, either all or some of the cells of the coenobium ex- 

 hibiting male and female characters. Male cells containing 

 sperniatozoids (antheridici) , the female finally changed into a 

 quiet oospore. Non-sexual propagation by means of motile 

 gonidia (macrogonidia and microgonidia). These arise from the 

 simultaneous and repeated division of the cell contents (cytio- 

 jjlastn). Macrogonidia definite in number (2, 4, 8, 16, &c.), 

 the larger oblong or rounded, with the anterior extremity more 

 or less rostellate, with two cilia exserted through the membrane 

 of the vesicle, furnished with a parietal red spot (eye-spot), and 

 often two contractile vacuoles. Microgonidia indefinite in 

 number, much smaller, pale or dull green, or yellowish, with 

 cilia at the apex, mostly even within the mother-cell, endued 

 with rapid motion, and ultimately escaping by rupture of the 

 membrane. 



Pritchard's " Infusoria " (p. 144) may be consulted with advan- 

 tage, although including some genera which undoubtedly belong to 

 Infusoria. Also the various memoirs hereafter referred to under the 

 several genera. 



The passage into amseboid conditions has been observed in several 

 genera, but this is a subject on which further investigation is needed. 

 T. C. White has seen it in Chlamydococcus (" Journ. Quekett Micr. 

 Club," 1679), Archer in Steplianosplicera (" Quart. Journ. Micr. Sci.," 

 1865, p. 127), and Dr. Hicks in Volvox ("Quart. Journ. Micr. Sci.," 

 1860, p. 99, and 1862, p. 96). 



GENUS 37. CHLAMYDOCOCCUS. Br. (1849.) 



Cells globose, or subglobose, (4-8 joined in a very fugitive 

 ccenobiuni), cell-membrane thickish, firm, cell contents granular, 

 brownish red or vermilion, in certain stages changing into green. 

 Macrogonidia 2-4-8 rounded, the frontal extremity bearing 

 very long cilia, and furnished with a central reddish nucleus 

 and four to six starch granules (not always visible) involved in 

 a very ample, hyaline, mostly ovoid tegument. Microgonidia 

 much smaller, numerous, yellowish or dull green, the apex 

 reddish, biciliate, moving actively within the mother cell, and 

 at last escaping, by rupture of the membrane. 



