Monadina.l iNFrsoHiAL animalcules. 133 



BoDO intestinal is. — Fonn almost conical, tail of equal length with 

 the body, transparent and colourless. Found in several living animals, 

 such as frogs, toads, &c. In the grey and edible frogs, amongst the 

 watery mucus of the alimentary canal, Ehrenberg has observed great 

 numbers of these creatures, and remarks that the Cercaria gijrinus of 

 Miiller (a different auimalciile) uiiglit pass as a representation of 

 this species, and that it was confounded by its discoverer with the 

 spermatic animalcules. G^roup 20 represents them magnified about 

 300 diameters. Size 1-1 720th. 



B. rananim. — Body turgid, ventricles indistinct. Found in live 

 fi'ogs, with the preceding species, and with the Burs aria rananim. 

 Size 1-1 440th. 



B. viridis. — Form neai'ly globular, tail very short, colour green. 

 Found amongst eonfervae. Size l-2400th. 



B. socialis. [Monas lens, M.)— Form ovate or subglobose; tail 

 often longer than the body ; transparent and colourless. Clusters 

 into a mulberry shape. Single forms are sometimes observed hop- 

 ping. Common in stagnant water. Size 1 -2970th. 



B. vorticellaris. The bell-shaped Bodo. — Body tlu-ee times as 

 long as it is broad ; tail very short. Found in fr-esh water. Size 

 l-11200th. 



B. didipnm. The douhle-tailed Bodo. — Body generally constricted 

 about midway, tail short. Size l-9600lh. 



'Q. saltans. — Very small ; body with ample ventricles; tail short. 

 This creature, most probably ft^om its small size, has been mistaken 

 for Miiller' s Monas termo, but its brisk leaping movement wiU suffi- 

 ciently distinguish it. Size 1-1 200th. 



B. grandis. — Form oblong, vesicles ample, tail rigid setaceous, 

 affixed to the abdomen. Found in stagnant water. Size l-864th. 



B. oystea. — Body globular; the anterior three-fourths occupied 

 with vesicles, the rest hyaline ; length of tail four times the diameter 

 of body. This active creatiu-e I discovered in the liquor of an 

 oyster, swimming freely among the ova (Sept. 1834.) Diameter 

 1 -2000th. 



The following genera named and described by Dujardin, are intro- 

 duced into his family Monadvna. 



Genus Cycliditjm, (D.) — Body discoid, compressed, or lameUiform, 



