218 BULLETIN 120, UNITED STATES NATIONAL MUSEUM. 



OPALINA HYLAXENA, new species. 



Type.— United States National Museum Cat. No. 16573. 



IJost. — IJyla versicolor LeConte, one fine infection, alive, from a 

 half-<?roAvn host, from Lelancl, Michigan, July 18, 1917; M. M. Met- 

 calf, collector. 



■ 'oi°- o'-o' o 

 o'.Voo'ci-o'.o 

 '•■'o o° o 



a b 



Fig. 190. — Opalina moreletii : a, magnified 117 diameters ; h, a bit op the body 



X 460 DIAMETERS. 







o 



o 



o 



o 



te.vo9...---V.:-:--.- o o 



b ! 



Fig. lUl. — Opalina iiylaxena : a, magnified 117 diameters; 6, a portion of the 



BODY X 460 DIAMETERS. 



Measurements of a good-sized individual. — Length of body 0.419 

 mm.; width of body 0.135 mm.; thickness of body, 0.0285 mm.; 

 diameter of nucleus 0.0056 mm. to 0.008 mm.; diameter of en- 

 dospherule, first 0.00126 mm., second 0.0015 mm., third 0.0016 mm.; 



