632 SYSTEMATIC HISTORY OF THE INFrSORlA. 



the oesophagus is distinct, of considerable length, and cihated, but not thick- 

 ened at any portion so as to produce the appearance of a dental cylinder " or 

 bacillar apparatus." Coloured food received by all the species. Contractile 

 vesicles one or two in number, and in Paramecium of a stellate figure. 

 Nucleus usually rounded, oval or reniform. A red spot, eye-speck or stigma, 

 is common in OphryogUna. Propagation takes place by fission, which may 

 be either transverse or longitudinal ; by the production of single living em- 

 bryos (at least this occurs in Paramecium and Colpocla) ; and, in Perty and 

 Carter's opinion, by numerous germs or internal ova. The encysting-process 

 has also been seen in all the genera except Uroleptus. The integument of 

 Kolpodea is reticulated, presenting a beautiful diamond-pattern, and ha^dng 

 a cilium seated in the centre of each lozenge. 



The Kolpodea are highly- organized Ciliata, although inferior in this -respect 

 to the Yorticellina. The single ciixumstance of the limitation of the ciha to 

 the head in the latter family is of itself, according to a well-recognized law 

 of animal life, an intimation of a higher grade of organization. 



The genera are disposed as follows : — 



CM . i T i f absent posteriorly Kolpoda. 



Short protruding tongue. J 



^ ^^ [ present everywhere Paramecium. 



Eye absent. 



No tongue 



With tail and proboscis Amphileptus. 



With tail, no proboscis Uroleptus. 



Eye present Ophryoglena. 



This family corresponds generally with that of the Parameciens or Para- 

 mecina (Duj.), thus defined: — Body soft, flexible, variable in form, but 

 mostly oblong and more or less flattened ; provided with a loose, reticulated 

 integument, upon which numerous \ibratile cilia are disposed in regular 

 series. Mouth present. The genera included are : — Lacri/maria, PleuronemUf 

 Glaucoma, KoljDOcla, Paramecium, Ampliilep>tus, Loxopliyllum, Chilodon, 

 Panoj^hrys, NassuJa, Holojjlirya, and Prorodoa. 



Dujardin observes that Lacrymaria and Pleuronema should probably be 

 placed in a distinct family, since the mouth is rather presumed than demon- 

 strated in them. Tliis is, however, a reason which, in the present day, would 

 not be held valid, as the evidence of a mouth is equally strong in them as in 

 others of the genera enumerated. 



Perty also has constructed a family Paramecina, containing the genera 

 Ophryoglena, Panophrys, Paramecium, Bhp>liarisma, and Colpocla, and briefly 

 characterized as having the body covered with longitudinal rows of cilia, and 

 a lateral mouth often ^\dthin a fissure. Lastly, Mr. Carter has instituted a 

 new genus, named Otostoma, referable to this family, being a close ally to 

 Paramecium. 



Genus KOLPODA or COLPODA. — Body ovoid, sometimes reniform ; a Httle 

 tongue-like member (a tuft of cilia) inserted in the oral ca\ity ; ciliated in 

 front and partly beneath ; eye-speck wanting. The mouth, posterior termi- 

 nation of the alimentary canal, and numerous gastric cells may be demon- 

 strated by coloured food ; the two orifices are both on the ventral siuface. 

 ''Ova," adds Ehi-enberg, " occur in delicate strings, forming a sort of network ; 

 and their extrusion has been seen in one species. A round contractile vesicle 

 is observable in two species, and two such in another. A large round or 

 oval gland (nucleus) is found in the centre of the body." Self-division botli 



