34 BULLETIN 120, UNITED STATES NATIONAL MUSEUM, 



are numerous spheroidal spherules in the endosarc, in which also may 

 be seen a well developed excretory vacuole, especially well developed 

 in the neighborhood of the nuclei. The two nuclei are spherical, or 

 very nearly so, and are near together. They are always connected 

 by a thread. In more than a thousand individuals observed no 

 case of mitosis was found, nor any instance of fission. In many in- 

 dividuals I was able to count four chromatin masses in each nucleus. 

 In a few other individuals each nucleus showed eight chromatin 

 masses. Six and seven chromatin masses also were found, also 

 instances of a larger number of smaller chromatin bodies. These 

 conditions indicate four as the probable number of the massive 

 chromosomes, but it is unsafe to say positively without observation 

 of the anaphase stage of mitosis, the stage when the chromosomes 

 are most characteristic in form and most distinctly seen. I have no 

 nuclei in this condition to observe. 



This species is similar to Raff's Protoopalina acuta^ soon to be 

 described, but differs in its broader form ; in its broadly rounded an- 

 terior end ; in its abruptly acuminate, almost spinelike, posterior ex- 

 tremity ; in the greater length of its cilia ; in the presence of cilia, ap- 

 parently of full length,^^ over all of the body, posteriorly as well as 

 anteriorly; in the approximation of its nuclei; in their larger size 

 and spherical, rather than ellipsoidal, form; in the thread which 

 always connects them. 



Protoopalina diplocarya still more resembles P. dor^salis (Raff) 

 in form, but its cilia are much longer than those of the latter species; 

 it is more nearly circular in cross section; its nuclei are nearer to- 

 gether than in P. dorsalis and they are always united by a thread. 



P. diplocarya differs from P. papuensis, next to be described, 

 in being less elongated posteriorly and especially in the condition of 

 its nuclei, which are spherical instead of pear-shaped. The internal 

 condition also is different as the description of P. papuensis will 

 show. 



PROTOOPALINA PAPUENSIS, new species. 



Type. — United States National Museum Cat. No. 16625. 



Host. — Hyla dolichopsis (Cope), one abundant infection of well- 

 preserved parasites, in United States National Museum specimen 

 No. 57718, from Sorong, Dutch Papua, 1906; Julius Hurter, sr., 

 collector. 



Measurements of an ordinary individual. — Length of body 0.315 

 mm. ; width of body 0.048 mm. ; length of nucleus 0.023 mm. ; width 



"• Usually in Opalinids collected from frogs which have been long preserved one finds 

 the cilia in quite Imperfect condition. But even in many such cases, when the cilia are 

 matted together, the width of the peripheral band composed of matted cilia, and the direc- 

 tion of the cilia in this band, Indicate roughly the length of the cilia. In the specimens 

 of this species studied the cilia are fairly clear. 



