Floscularui.] the INFUSORIA. 343 



Genus CXLIII. Tubicolaria. The encased wheel 

 Animalcules are destitute of eyes at all ages (?) have a four- 

 lobed rotatory organ, and a gelatinous case {urceolus). 

 Their internal structure comprises four posterior longitudi- 

 nal muscles, an alimentary canal, with a long stomach, 

 devoid of coecal appendages ; a short rectum, an oesophagal 

 head with four muscles, two jaws with teeth, two semi- 

 spherical pancreatic glands, and an ovarium, with a single 

 ovum. Anteriorly, upon the ventral surface, are two res- 

 piratory tubes. 



574. Tubicolaria najas. The mantle Tubicolaria. — 

 The jaws have four teeth, and the respiratory tubes are 

 hairy anteriorly. It is described fully in the account of 

 the genus, and Jigures 379 to 382 will illustrate it; 381 

 represents those of the natural size, as found attached to 

 the roots of Lemna polyrrhiza, with those of the following 

 genus ; 379 represents an animalcule within its case, the 

 rotatory organ withdrawn ; 380, another animalcule ex- 

 tended, and without its lorica. Fig. 382 shews the oeso- 

 phagus, with the jaws and teeth separate. Length l-36th. 



Genus CXLIV. Stephanoceros. The crown-wheel 

 Animalcules have one eye, and a rotatory organ, deeply 

 divided into lobes, and furnished with verticellate cilii : 

 this organ performs the office of locomotion. Their nu- 

 tritive apparatus consists of a simple alimentary canal, 

 with a stomach, and small rectum ; the oesophagal head 

 has jaws, with free teeth, four in number ; before it is a 

 large crop-like structure, and two glands at the stomach ; 

 the ovarium only developes a few ova at a time ; perhaps 

 two male glands exist at the commencement of the row of 

 tremulous gills ; a red visual point, with a row of nervous 



