238 BULLETIN 120, UNITED STATES NATIONAL MUSEUM. 



middle 0.0345 mm., posterior 0.0275 mm. (a smaller individual has 

 these three measurements of thickness, respectively, 0.016 mm., 0.024 

 mm., 0.02 mm.) ; diameter of nucleus 0,004 mm. to 0.0055 mm., mean 

 0.005 mm. ; diameter of endospherule 0.0014 mm. ; cilia line interval, 

 anterior 0.00175 mm., posterior 0.00412 mm.; basal granules in the 

 lines of the anterior cilia 800 to the millimeter. 



This species is much like O. raTiaruTn in shape, extept that it is 

 thickest in the middle. Its nuclei run smaller than in 0. ranarumi. 

 Its endospherules are usually small. Its cilia are very numerous 

 anteriorly, the lines of their insertion being close together and the 

 basal granules (cilia) being very close together in these lines. This 

 is a well demarcated species. |. 



OPALINA LATA Bezzenberger (1904). 



Host. — Rana limnocharis Wiegmann, from "Asia." I have had 

 no material of this species. 



Fig. 213. — Opalina lata, x 350 diameters. (Afteb Bezzbnbesgeb.) 



Measurernents.— Length of body 0.3 mm. ; width of body 0.18 mm. ; 

 thickness of body 0.0126 mm. ; diameter of nuclei 0.0049 mm. 



The rows of cilia are "extraordinarily close together" and the 

 nuclei are very numerous. This species is ranarum-like in form, 

 but has smaller nuclei. It seems also similar to O. draytonii from 

 western North America and to O. camerunends from western Africa. 

 The rows of cilia are " extraordinarily close together " in the latter 

 species also, and the cilia are very closely set in the rows, so 0. lata 

 and 0. camerunensis agree in being densely ciliated. O. camerun- 

 ensis is nearly twice as thick as O. lata. 



