No. 2.] FRESH-WATER PROTOZOA. 37 



Chlamydomonas Ehrbg. 



Spherical to cylindrical, with a delicate shell and 

 prominent chromatophores, which form the chief mass of 

 the body, and contain one or more spherical or ribbon-like 

 pyrenoids. Two flagella, a nucleus, and an eye-spot, and 

 two contractile vacuoles present. Multiplication by di- 

 vision, usually in a resting stage. 

 Chl.sp. (?),Fig. ii6. 

 Chlorangium Stein. 



In the motile condition, spindle-shaped, with two fla- 

 gella, a delicate shell, and two green, ribbon-shaped 

 chromatophores. Two contractile vacuoles at base of 

 flagellum with a central nucleus, but no eye-spot. In 

 passing into a resting stage it attaches itself by its an- 

 terior end and loses its flagella, but secretes a short stalk. 

 While in resting condition, body divides into four parts 

 which burst the shell and secrete stalks, so that a small 

 colony arises. 

 Chi. sp. ( ?). Fig. 114 I place with doubt in this genus. 

 Synura Ehrbg. 



Spherical colonies of about fifty radially arranged in- 

 dividuals. Individuals ellipsoidal with a delicate cuticle 

 which is often covered with spines. Two brown chromato- 

 phores. Nucleus central and many contractile vacuoles. 

 Eye-spots at the base of the flagellum. The single indi- 

 viduals either united by their hind end or held loosely to- 

 gether by means of the shell. 

 Sy. uvella Ehrbg., Fig. 104. 

 Spondylomorum Ehrbg. 



Colonies of sixteen individuals which are arranged in 

 four alternating rows. Multiplication by the division of 

 the individuals into sixteen cells. Each individual of the 

 colony bears four flagella. 

 Sp. quaternarium Ehrbg., Fig. 108. Shown in condition of 

 multiplication at Fig. io8a. 

 Pandorina Ehrbg. 



Spherical colonies (thirty-two cells) on the inside of 

 a spherical shell. The individuals are remote from the 

 outer shell, and each bear two flagella. 

 Eu. elegans ( ?) Ehrbg., Fig. 109. 



