OPALINID CILIATE INFUSORIANS METCALF 



491 



indeed there be distinct species in this exasperating genus that refuses 

 to play the Linnaean game, but it is difficult to give a diagnostic 

 description. Yet, on the basis of the strong impression from the 

 study of whole infections of this and other Zelleriellas it resembles, I 

 am giving it a distinctive name, pending more detailed study of 

 further material from this species of host. 



ZELLERIELLA OVONUCLEATA. new species 



FlGTJRE 45 



Type: U.S.N.M. No. 22631. 



Host: Leptodactylus pentadadylus (Laurenti). One specimen 

 from Bello Horizonte, Brazil, 135 mm. long, was uninfected. A 

 rectum of another specimen from the same locality, given me by Dr. 

 Lauro Travassos, showed very few Zelleriellas. 



Figure a.—Zelleriella ovonudeata, new species, X 249. 



Measurements, in microns: 

 Measurement 



Length of body 

 Width of body. 

 Nucleus length. 

 Nucleus width. 



SmaU 



In size and shape of body and of nuclei, and ua relative size of body 

 and nuclei, this form agrees with a Zelleriella from Bufo sternostignotus 

 Keferstein (see Metcalf, 1923a). The nuclei of the latter form were 

 never found so elongated as in the form from Leptodactylus penta- 

 dadylus, but the difference is slight. I am naming the species Z. 

 ovonudeata and am naming the form formerly mentioned tentatively 

 as Z. [of Bufo sternostignotus] as subspecies bufonis of the species 

 ovonudeata. 



