Monadina.'} ixTTso-RTa. aktat xt.cft.-es. 127 



amongst confervaj and lomna. Size l-2000tl) ; diameter of cluster 

 l-280th. 



TJvELLA chamaemopim. — Smaller than the preceding one. Found 

 in water-butts. Size 1 -2880th ; diameter of cluster 1-5 70th. 



U. tiva. — Has indistinct vesicles, and is vciy small. Found in 

 stagnant water. Size l-4800th; diameter of cluster l-960th. 



U. atomus. {JTotias atomus, M. lens et Volvox socialis, M.) — 

 Voracious, with large vesicles. Size 1 -6900th to 1 -3406th; diameter 

 of cluster l-1150th. 



U. glaucoma. ( Vohox socialis, M.) — Form oval, but inclining to 

 conical, with the posterior extremity attenuated as it advances in 

 age. Hyaline, with large vesicles, and two evident filiform probos- 

 cides: individuals loosely aggregated. In 1831, Ehrenberg first 

 observed a vibration at its anterior part, and. its reception of coloured 

 food. In 1835, he discovered within the body of this minute 

 creatui'e some gi'een Monads which it had eaten, and by which it 

 was proved to subsist by prey. When fed on indigo, as many as 

 twelve stomachs were filled, and it has been sometimes seen to void 

 little blue particles, like undigested matter, from its mouth. With 

 a power of 800 diameters, a great number of small colourless 

 granules, having the appearance and form of ova, may be discerned 

 lying between the nuti'itive sacs. It increases both by transverse 

 and by longitudinal fission. Engi-aving, group 3, represents a 

 cluster of these creatures ; figiu'es 4 and 5, separate young ones ; 

 and 6, an old one. They are magnified about 350 diameters. The 

 indi\'iduals, when full grown, are elongated. Found in water-butts. 

 Size l-2300th to l-2350th; diameter of cluster l-430th. 



U. hodo. — Fore part of the body rounded ; posterior attenuated. 

 It is of a beautiful gi-een colour ; found in stagnant water. Size 

 l-4030th to l-3450th; diameter of cluster l-2350th. 



Genus Miceoglena. — TJie eye Monads. — This genus is essen- 

 tially characterized by all its species having a minute red eye-like 

 speck situated at the anterior part of the body. In other respects 

 they resemble time Monads, being deficient of the projecting lips 

 and tail, and swimming in the direction of the long axis of the body. 

 They possess a very delicate flagelliform proboscis, of simple sti-ueture. 



