538 



PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 87 



by having the nucleolar substance in a spherical mass and the chro- 

 matin in the form of a very well defined, rather coarse spireme. It 

 is a very distinct species well described and well illustrated by Weill. 



Measurements, in microns: Adult, body 210 by 56, nuclei 6.7, 7.4, 

 4.8 (daughter nucleus), length of cilia 4.3; cyst 13, with 2 nuclei 13.2, 

 with 11 nuclei 24.6; nuclei (uninucleate) 4, (binucleate) 3.2, (4 

 nuclei) 3.2 by 2.4; animal just hatched from cyst, body 44.2 by 16.7, 

 nucleus 3.2; "encysted adults," body 83, 100 by 47. 



The slender form of this Opalma is an unusual thing for an Eastern 

 Hemisphere species. It may be an unusually flat Cepedea, like C. 

 virgula. There seems to be no likelihood of its being genetically 

 related to the Opalinae angustae of the Western Hemisphere. 



OPAUNA NUCLEOLATA, new species 



Figure 106 



Type: U.S.N.M. No. 22649. 



Host: Rana chalconota (Schlegel), from Buitenzorg, Java, three 

 specimens. 



O 



®o o 



®0 ° 







Figure 106. — Opalino nucleolata, new species, from Rana chalconota: a and 6, X 78; c, X 673. 



From the largest of these frogs (U.S.N.M. No. 43933), 54 mm. 

 long, were obtained many very large Opalinas with large nuclei and of 

 shapes rather uniform and about like those of some infections of 

 0. ranarum, but their nuclei show a peculiarity that distinguishes 

 them. Their nucleolar substance is gathered into one or two globular 

 masses, slightly flattened against the nuclear membrane when in 

 contact with it, apparently spherical when lying deeper in the nucleus. 

 In my material the chromatin is scattered and not readily distin- 

 guished, not at all like the chromatin coil in young forms of Weill's 



