Volvocina.] infusoeial aniaialcttles. 161 



never protruding out of their cells from the common envelope. Ej^e 

 sparkling red. The clusters which are of an oval or globular form, 

 contain generally from 30 to 50 individuals, and never less than 15. 

 Motion rotating. Figure 47 is a cluster magnified; it exhibits the 

 proboscides extended, and the bodies of the animalcules within the 

 lorica. Clusters of these beautiful animalcules ai'e often seen in such 

 amazing numbers, along with the Folvox (ilohator and Chlamidomonas 

 puktsculus, as to render the water (otherwise colouiiess) of a decided 

 green colour, especially towards its edges. They are exceedingly 

 delicate, so much so, that it is difficult to preserve them alive for more 

 than a day or two : whenever it is attempted to retain them in large 

 quantities, the second day will generally exhibit a thick mass of dead 

 ones at the bottom of the vessels. "VVTien a few only remain alive, 

 if the water be poiu-ed away, and the creatures removed into a vessel 

 of clear water, they will live for weeks. Found at Hackney and 

 Hampstead ; most abundant in the spring of the year. Diameter of 

 cluster 1-1 80th. 



Genus Chlamidomonas. The cuiras Monad Animalcules are cha- 

 racterized by being deficient of the tail, but provided with a beau- 

 tiful red eye, indicating a sensitive system, and with a double 

 fiagelliform proboscis, for the purpose of locomotion, &c. The shell- 

 like envelope, which bears the form of a little box (wceolus) encloses 

 the creature up to the mouth, and when the young have attained to 

 maturity and self-division is to be completed, it bursts, to set 

 them at liberty. The lorica is with difficulty perceived upon the 

 young ones. 



C. pulmsctdus {Monas pulvisculus, M.) — Body composed of green 

 corpuscles, of an oval form, and included within a box-like shell. 

 Eye brilliant red, and proboscis double. The clusters are globular, 

 and made up of only tliree or four, or at most eight ? Group 52 re- 

 presents a single one ; also a cluster about to separate into five 

 the latter enclosed in a common envelope. See Diselmis vmdis 

 (Duj.) 



These creatures form the larger portion of the green matter which 

 colours the water contained in water-butts, ponds, and puddles, in the 

 summer and autumn, and especially after a storm. It could hardly 



