OPALIjS'ID CILIATE INFUSORIANS — METCALF 



549 



^ The cilia on the anterior part are much longer than the posterior 

 ones. The pointed taillike end is deprived of cilia. The nuclei 

 are ellipsoidal or rounded and almost of the same size. There are 

 many spherical or elongate-oval endospherules in the endosarc. 

 1^ Measurements, in microns: In a number of individuals the body 

 length varies from 73.1 to 107.8, the width from 55.9 to 93.7, the 



Figure in.—Opalina cheni Nie from Kaloula borealu. (After Nie.) 



diameter of the nucleus varies from 4.9 by 3.6 to 7.6. The measure- 

 ment of the cilia line interval at the anterior end of one animal 

 was 3.7. 



This species is characterized by the permanent presence of several 

 folds or ridges on the surface of the body. These folds closely resem- 

 ble those found in 0. obtrigonoidea forma plicata Metcalf (1923a). 

 The present species, however, differs from the latter not only in the 

 larger diameter of the nucleus but also in its ciliation and the smaller 

 size of the body. 



OPALINA ACUMINATA Nie 



Figure 118 



Host: Kaloula borealis Barbour, from Nanking, China. 



The form of the body varies greatly from lanceolate to ellipsoidal. 

 The anterior edge is obliquely truncated. The posterior extremity 

 is drawn into a short sharply pointed spinelike process. The greatest 

 width is recorded at the region anterior to the middle of the body. 

 The nuclei are ellipsoidal or rounded, or elongate in form during 

 mitosis. 



The layer of ectosarc is fairly thm, but it is well marked off from 

 the endosarc, which is vacuolated in appearance. 



Measurements, in microns: In a number of specimens the length 

 of the body varies from 59.5 to 131.6, the width from 29.7 to 56.0, 

 the diameter of the nucleus from 5.3 to 5.8. The cilia-lme mterval 

 on one animal measured 1.9 on the anterior end and 2.1 on the pos- 

 terior end. 



