92 



BULLETIN 120, UNITED STATES NATIONAL MUSEUM. 



Measurements: A, of a wedge-shaped individital; B, of a hroader 

 individual — 



Measurements. 



WtTO. 



Length of body 0. 097 



Width of body 0. 571 



Length of nucleus • • 0135 



Width of nucleus 01 



mm. 



0.091 

 .083 

 .0135 

 .0087 



There are apparently eight massive chromosomes. 

 This small Zelleriella has two distinguishable forms, which, how- 

 ever, intergrade. In one form the individuals are broadly wedge- 



^ d c 



Fig. 59. — Zellekiella atelopyxena : a to c, individdals whose nuclei ahe in mitosis, 



X 460 DIAMBTEES ; i, A. N0CLKDS IN MITOSIS SHOWING 8 MACROCHROMOSOMES, X 1,000 

 DIAMETERS. 



shaped (fig. 58, d, g and 59, c), usually with the posterior end dis- 

 tinctly pointed. The broad, rounded individuals are not usually 

 pointed posteriorly. The nuclei are broadly ellipsoidal in the rest- 

 ing condition. In active mitosis the nuclei are more elongated, or 

 spindle-shaped, or dumb-bell-shaped. Several daughter cells were 

 found with both nuclei spherical. In several nuclei eight massive 

 chromosomes were counted (fig. 59, d). 



