THE OPAULNID CILIATE INFUSOKIANS. 93 



ZELLERIELLA ATELOPYXENA [STELZNERI], new subspecies (?). 



Type. — A specimen of this form has been deposited with the 

 United States National Museum as No. 16466. 



Host. — Atelopus stelzneri Weyenburgh, two infections, in United 

 States National Museum specimens No. 28481 (the type infection, 

 abundant) and No. 28521 (scant infection), both from Sapucay, 

 Paraguay, W. T. Foster, collector. 



Fig. 60. — Zblleriella atelopyxena [stelzner], x 460 diameters: 5 is a dadohtbb 



CELL. 



Measurements: A^ of a slender individual; B^ of a hroader indi- 

 vidual — 



Measurements. 



Length of body... 

 Width of body.... 

 Length of nucleus 

 Width of nucleus. 



This seems to be a slender variety of Z. atelopyxena. The pos- 

 terior end of the body in most individuals is rounded, not pointed; 

 in a few others it is distinctly pointed. The nuclei are rather simi- 

 lar in the species type and in its variety. I am naming the variety 

 only tentatively, pending further study of more abundant and better 

 material. 



ZELLERIELLA [ENGYSTOMOPSIS], new species (?) (figs. 61 and 62). 



Type. — A specimen of this form has been deposited with the 

 United States National Museum as Cat. No. 16467. 



Hosts. — Engystomops stentor (Espada), three infections, in United 

 States National Museum specimens No. 51959 (the type infection, 

 abundant), Nos. 51957 and 51958, all from Taboga Island, Panama, 

 June 12, 1914, J. Zetek, collector; also Engystomops pustulosus 



