194 DESCRIPTION OF Polygastnca.'] 



blackish- coloured spots, analagous to the eyes in the species of other 

 tribes. The Distigma are sometimes confounded with Proteus diffluens 

 of Miiller. All the species are exquisite objects for a deep powered 

 microscope, for instance, one magnifying 460 diameters. 



Distigma tenax {Proteus, M.) — Body larger than in either of the other 

 species, proteus-like, at times greatly distended, then as much con- 

 stricted : eyes rather indistinct ; colour transparent yellow. Found 

 about Lemna. Length 1 -240th. 



D. proteus {Proteus, M.) — Body smaller than the preceding, pro- 

 teus-like, sometimes greatly distended, at others constricted, blunted at 

 both extremities; eyes distinct. Group 81 represents these crea- 

 tures highly magnified. Found amongst conferva. Length 1 -580th. 

 to l-400th. 



D. viride. — Body smaller than in either of the other species; 

 proteus-like, sometimes greatly distended, at others constricted; 

 filled with green granules ; eyes distinct. Length not exceeding 

 l-570th. 



D. planaria. — Body small, linear, proteus-like, but less distended 

 or constricted than the preceding, pointed at both extremities ; 

 colourless ; eyes distract. Found by Ehrenberg amongst Conferva 

 in the Nile. Length 1 -240th. 



The following genera and species, are included by Dujardin in 

 this family. 



Genus Peranema. — Body of variable form, sometimes almost glo- 

 bular, at others distended posteriorly, and drawn out in front, or 

 prolonged into a long tapering filament. Movement forwards, slow, 

 uniform. 



The Peransma are colourless, but contain in their diaphanous sub- 

 stance, granules and vacuolae. The lobes they send out in their 

 frequent and remarkable changes of form, are, luilike those of 

 the Amceba, covered with an integument. They are found in stag- 

 nant marsh water, chiefly on the surface of dead plants. 



I suspect Ehrenberg has described a species fP. protractaj of this 

 genus, under the name of Trachelius trichophorus. 



P. protrada. — Body oblong, soft, dilated posteriorly, much ex- 

 tended anteriorly. Length l-838th. to l-370th. 



