136 BULLETIN 120, UNITED STATES NATIONAL MUSEUM. 



This Zelleriella is distinguished by the very dense ciliation, and the 

 usually narrow form of its anterior end, and also by the position of 

 the nuclei, which are usually well back in the body. The nuclear phe- 



Fio. 100. — Zelleriella hirscta : o^ a cyst, X 1,000 diameters ; h, an optical, ver- 

 tical SECTION, X 460 diameters ; C, A CELL WITH TWO APPARENTLT NORMAL NUCLEI 

 AND FIFTEEN SMALL NUCLEI <?) OF DIFFERENT SIZES, PORTIONS OF THE ENDOSARC WITH 

 ITS ENDOSPHERULBS BEING REPRESENTED, ALSO PORTIONS OF THE LINES OF INSERTION 

 or THE CILIA, X 460 DIAMETERS. 



nomena are similar to those in Z. [of Bufo woodhousi]. The "pri- 

 mary" nuclei, in my material, are readily distinguished by their 

 darker staining, even in individuals in which they are not larger than 

 the largest of the " secondary nuclei." The species seems quite dis- 

 tinct. Its body form and dense 

 ciliation would almost justify 

 classification in a distinct genus. 

 In connection with the nuclear 

 phenomena in this and the last de- 

 scribed species it is interesting to 

 note that Eaff (1912) reports find- 

 ing certain " abnormal " multinu- 

 cleated forms (fig. 101), probably 

 of Zelleriella hinucleata^ in a 

 specimen of Limnodynastes dor- 

 salis from Heathcote, Victoria, 

 Australia. These individuals, of 

 diverse shapes, had from three to 

 eight nuclei arranged in no regu- 

 lar way. Raff regards them as " abnormal forms, in which the nuclei 

 have divided irregularly without the body dividing." It seems likely 

 that the phenomena observed were similar to those seen in Zelleriella 

 [of Bufo woodhousi^ and Z. hirsuta. 



Fig. 101. — "Abnormal forms of Opalina" 

 [Zelleriella] from Limnodxnastbs 

 DORSALis. (After Raff.) 



