Tracheiina.] THE INFUSORIA, 297 



The intestinal Bursaria has a slender cylindrical body, at- 

 tenuated posteriorly ; mouth small, below the frontal apex. 

 In this species, as well as in others, Ehrenberg has seen 

 transverse self-division. Size 1 -240th to l-120th. 



481. Bursaria (?) cordiformis. The heart-shaped Bur- 

 saria. — Body reniform, front depressed, mouth slightly 

 curved in a spiral manner; colour white. Size 1-2 10th. 



482. Bursaria lateritia [Trichoda ignita, M.) The 

 hrick-red coloured Bursaria. — Body compressed, ovato- 

 triangular, with the front sharply crestated. Found with 

 lemna, conferva, &c. Size l-430th to l-144th. 



(6.) Frontonia. — Anterior part oj' the body [broiv] projects 

 beyond the mouth, and is convex. 



483. ^VK^xniA vernalis {henco2ihravirescetis,^.) The 

 spring Bursaria has an oval turgid body, rounded at the 

 ends, and attenuated posteriorly. The mouth has a wreath 

 of stiff short bristles, resembling teeth ; numerous stomach 

 vesicles are often filled with large Oscillatoriae, Naviculae, 

 &c., and contain a reddish bile. The process of digesting 

 the Oscillatoriae is interesting to follow : — they are at first 

 elastic and rigid, and of a beautiful blue green colour, then 

 distinctly lax, flexible, and bright green, becoming after- 

 wards yellowish-green, and falling into separate articu- 

 lations, which at length turn yellow. Found amongst 

 oscillatoria in spring. Length 1 -144th to l-120th. 



484. Bursaria leiicas. The lohite Bursaria. — Body 

 oblong, cylindrical extremities nearly equi-convex, bile 

 colourless (see Jig. 295). This creature has a contractile 

 bladder, with a curious jagged margin near the long open 

 mouth. Found with oscillatoria, and on the surface of 

 water. Size 1 -144th. 



