70 BULLETIN 120, UNITED STATES NATIONAL MUSEUM. "■ 



mitosis than are the nuclei of ProtoopaliTia regularis, next to be 

 described. 



PROTOOPALINA REGULARIS, new species. 



Type. — United States National Museum Cat. No. 16451. 



Host. — Bufo regulans Reuss, 4 infections out of 13 toads opened, 

 5 (3 infected, 2 not infected) being from the Gold Coast, western 

 Africa, December 10 and 29, 1889, W. H. Brown, collector (one of 

 these, United States National Museum specimen No. 16064, giving 

 the type infection), and 8 (1 infected) from the Tana River, East 

 Africa, November, 1892 ; W. A. Chanler, collector. 



Measurements of the average individual shown in figure 1^1. — 

 Length of body 0.196 mm. ; width of body 0.0587 mm. ; thickness of 

 body 0.0375 mm. ; length of posterior process 0.0087 mm. ; length of 

 nucleus 0.03 mm. ; width of nucleus 0.013 mm. ; diameter of endo- 

 spherule 0.0025 mm. ; cilia line interval, anterior 0.002 mm., posterior 

 0.0047 mm. 



®-x^ 



Fig. 41. — Peotoopalina regularis, X 460 diameters. The macrochromosombs arb 



DRAWN ONLY IN THE UPPER PORTIONS OF THE NUCLEI. 



This Protoopalina somewhat resembles P. caudata in form. The 

 posterior end of the body usually bears a distinct, naked, spinelike 

 process which is sharp-pointed. The nuclear conditions are quite 

 various, chiefly because rather numerous daughter cells, recently 

 come from division, are present. The ordinary resting condi- 

 tion is seen in figure 41, in which we note two daughter nuclei 

 still united by a thread. Each of these nuclei, though they are 

 not yet completely separated, has entered upon the next mitosis 

 and is in an anaphase condition, with two sets of distinct macrochro- 

 mosomes, eight in each set. In the figure only those massive chromo- 

 somes which lie on the upper sides or the edges of the nuclei are 

 drawn. There are in reality three other chromosomes in each set, 

 not drawn, lying beneath those shown, making eight massive chromo- 

 somes in each set. 



In addition to these, the common sort of individuals, there are 

 others which have recently come from fission and show but a single 



