HETEROTRICHIDA 379 



third with comb-like structure posterior to it. Oval macro- 

 nucleus dorsal. Fresh water. 



Epalxis mirahilis Roux (Fig. 163, a). Body 32 to 40 microns 

 long by 27 to 30 microns broad. 



Genus Pelodinium Lauterborn. Body form constant. Simi- 

 lar to Epalxis, but the posterior end narrowed. 



Pelodinium reniforme Lauterborn (Fig. 163, b). Body 40 to 

 50 microns long. 



Genus Discomorpha Levander. Anterior end with a ven- 

 trally pointed spine. There are two spines on the right side of 

 the body. 



Discomorpha pectinata Levander (Fig. 163, c). Body 60 to 

 80 microns long. 



Genus Saprodinium Lauterborn. With six or eight posterior 

 spines, but none on the sides. 



Saprodifiium dentatum Lauterborn (Fig. 163, d). Body 80 

 microns by 72 microns. 



Suborder 2 Tintinnoinea Kofoid and Campbell 



These Hetrotrichida possess a conical or trumpet-like body, 

 attached inside a lorica which is composed of gelatinous or 

 pseudochitinous substances and which varies in shape. Body 

 with several longitudinal rows of cilia, and two macronuclei and 

 two micronuclei are present in the majority. The organisms are 

 mostly pelagic, a few inhabiting brackish or fresh water. Kofoid 

 and Campbell distinguished more than 300 species and placed 

 them in 12 families and 51 genera, of which 23 genera were es- 

 tablished by them. Here a fresh water genus is mentioned. 



Genus Tintinnidium Kent. With an elongated lorica, highly 

 irregular in form ; soft in consistency. Aboral end closed or with 

 a minute opening. Wall viscous and freely agglomerates foreign 

 objects. Salt or fresh water. 



Tintinnidium fliiviatile (Stein) (Fig. 163, e). Lorica about 

 125 microns high by 45 microns broad. Widely distributed on 

 aquatic plants in fresh water. 



Tintinnidium semiciliatum (Sterki) (Fig. 163, /, g). Body 

 length 40 to 60 microns. Widely distributed on aquatic plants 

 in fresh water. 



