488 



PROCEEDINGS OF THE NATIONAL- MUSEUM 



VOL. 87 



FiGUisE iZ.—Zellerietta antunesi Pessoa (?) from tadpoles of hufo crucikr: Free-hand drawings from life or 

 from nonpermanent specimens treated with acetic acid or with acetocarmine. Magnifications not 

 recorded. All are in Pro^oopa/jna-larval stages. 



Measurements, in microns, of 4 individuals — a, b, and c from Bufo 

 crucifer, d from Leptodadylus ocellatus: 



Measurement 



Length lof main body 

 Length to tip of taiL. 



Width of body 



Length of nucleus 



Width of nucleus 



c (in 

 fission) 



175 

 23 

 23 

 15 



100 

 125 



60 



17 



12. 3 



ZELLERIELLA ANTUNESI QUADRAT A. new forma 



Type: U.S.N.M. No. 22629. 



liost: Bufo crucifer Wied, from Rio de Janeiro, Brazil. 



Of 24 individuals of this toad, 12 were uninfected with opalinids, 

 5 bore abundant Z. antunesi, 2 showed Z. uruguayensis, and 5 bore 

 intermediate forms either with slight tails or a peculiar angular con- 

 tour, not protuberant, where a tail might have developed. These 

 last might almost be called forma quadrata. Their small nuclei dif- 

 ferentiate them from the species uruguayensis. In a small pond, 



