134 



BULLETIN 120, UNITED STATES NATIONAL MUSEUM. 



this stud}' upon Z. antilliensis^ but anyone having favorable material 

 of an}^ Zellenella would do well to take advantage of the opportunity. 

 One of the species of Zelleriella with four chromosomes would be best. 



If both the small and the large bodies in Z. [of Bufo looodhousi] 

 are indeed true nuclei belonging to the Opalinid, we see that there 

 may be much confusion in our data as to nuclear size if we are not 

 careful, in our comparison of species, to compare similar phases ot 

 the life cycle, and the danger of confusion is equally great if the 

 phenomena be abnormal. 



Comparison with other Zelleriellas seems to indicate that Z. [of Bufo 

 looodhousi] is a distinct species, though it is possible that some of 

 the small Zelleriellas with small nuclei, already described, may be of 

 this species, being taken at a time when their original nuclei have dis- 

 appeared and been replaced by "secondary nuclei." Compare Z. 

 leptodacfyli, Z. [of Hyla septentrionalisl , Z. microcarya. But I in- 

 cline to the opinion that the phenomena of " secondary nuclei " are 

 associated with parasitism and are abnormal. 



Measurements: A, of a large individual with.'"'' degenerating pri- 

 mary nuclei and numerous secondary nuclei^\' B, of a hroad indi- 

 vidual with '■^primaiy nuclei and four secondary nuclei "/ 6', of a 

 daughter cell with one dumb-hell " primary nucleus and numerous sec- 

 ondary nuclei "/ />, of a daughter {f) cell with two '•'■secondary " {?) 

 nuclei — 



Measurements. 



Length of bod^' 



Width of body 



Diameter of: 



Nucleus 



Largest secondary nucleus. 



Smallest secondary nucleus 



Length of endospherule 



Width of endospherule 



Cilia line interval 



0.147 

 0.074 



Collapsed . 

 0. 013 

 0. 0085 

 0.002 

 0. 0013 

 0.002 



0. 0685 

 0. 0513 



0. 0084 



0.004 



0.003 



mm. 



0.085 



0.035 



0. 0073 

 0. 0048 



mm. 

 0. 0587 

 0.036 



0. 0076 



ZELLERIELLA HIRSUTA, new species. 



ry/?d.— United States National Museum Cat. No. 16500. 



Host. — Bufo cognatu-s Say, two infections, one from Fort Mohave, 

 Arizona, the other, the type infection, from United States National 

 Museum specimen No. 35629, 64 mm. long, from Phoenix, Arizona; 

 M. C. Dick, collector. 



Measurements of an ordinary individual. — Length of body 0.113 

 mm. ; width of body 0.06 mm. ; thickness of body 0.0215 mm. ; diameter 

 of nucleus 0.011 mm. ; diameter of largest " secondary " nucleus 0.0052 

 mm. ; diameter of smallest " secondary " nucleus 0.003 mm. 



