130 



BULLETIN 120, UNITED STATES NATIONAL MUSEUM. 



This seems but a broader form of Z. opisthocarya. The hirge in- 

 dividuals for the most i^art have the nuclei placed well back in the 

 body. The smaller individuals differ from one another, some show- 

 ing the nuclei back, some iiaving them farther forward. It seems 

 that the former are anterior daughter cells, the latter posterior 

 daughter cells. One posterior daughter cell was seen with its two 



I 



Fig. 96. — Zelleriella opisthocauta [of Bufo typhonius], x 460 diameters. 



nuclei well forward and still united by a thread. The material is 

 not favorable for the study of the internal structure of the nuclei, 

 though in the individual last mentioned an anaphase condition was 

 evident, with seemingly eight macrochromosomes. 



As I am unwilling, without further study than the material allows, 

 definitely to assign this form to the species type, it is provisionally 

 referred to its host as a possibly distinct subspecies. 



