Oecistina.'] infusobiax animalcules. 611 



Glenophora frochiis. — Body ovato-conical, truncated, and turgid 

 anteriorly, attenuated posteriorly into a false foot; the eyes are 

 blackish. It swims quickly, like a Trichodina or free Vorticella. 

 The genera Monolabis and Microcodon have similar forms. 

 Figs. 359, 360, represent two animalcules, the latter having the 

 stomach filled with a green substance. Size 1 -570th. 



Family.— OECISTINA. 



Rotatoria with a single rotatory organ entire at the margin, with 

 a gelatinous envelope or lorica. This family contains only two 

 genera, which possess an organization more developed than any yet 

 described. Locomotive organs, with internal muscles, (says Ehren- 

 berg,) and a tail foot, not pincer-like, nutritive organs, with a 

 chewing apparatus, consisting of teeth in rows, two pancreatic 

 glands, as well as the development and expulsion of ova, are 

 observed. Male organs, vessels, two filiform tremulous organs 

 (gills), and nervous fibrillse, along with ganglia, are elicited in 

 Conochilus, and red visual spots in both genera. They are thus 

 tabulated : 



special and tUstinct to each single animalcule Oecistes. 



Lorica ' 



rica J 



L cong' 



lomerate, or common to many single animalcules Conocliilus. 



Genus Oecistes. — The sheathed little Jish Animalcules are 

 characterised by each animalcule having a separate lorica. They 

 have two eyes, situated anteriorly, which become effaced as age 

 advances. A simple wreath of cilia is observed in the frontal 

 region of the body; the long tail-like foot has internal longitudinal 

 muscles. A simple tubular contracted alimentary canal, with an 

 elongated stomach, teeth in rows, attached to two jaws, situated at 

 the head or bulb of the oesophagus, and two pancreatic glands, 

 compose the apparatus of nutrition. The visual organs are red 

 when the animalcule is young, and colourless in old age. The 

 ovarium has only a single ovum. The lorica is a viscid, gelatinous, 

 cylindrical box (urceolus), into which the animalcule can entirely 

 withdraw itself, or which it may quit when a new one is desirable. 



