LAG EN IDI ALES 963 



KEY TO THE SPECIES OF PSEUDOSPHAERITA 



Parasitic in Euglena ; globules of zoospores not radiately arranged in the 



sporangium Ps. euglenae, p. 963 



Parasitic in Cryptomonas; globules of zoospores radiately arranged in 



the sporangium Ps. radiata, p. 963 



Pseudosphaerita euglenae Dangeard 

 Le Botaniste, 4:242, fig. 9. 1894-95; ibid., 25:36, pi. 4, figs. 3-15. 1933 



(Fig. 76 A, p. 960) 



Sporangium somewhat ellipsoidal, oblong, or tubular; zoospores 

 elongate-pyriform with attenuated apex, 6 \x long by 2.5-3 u. wide, 

 with a small granule at the point of insertion of the flagella, initiating 

 movement within the sporangium, swimming motion accompanied 

 by a trembling of the body. 



Parasitic in the cytoplasm of Euglena, sometimes accompanying 

 Sphaerita, Dangeard (loc. cit.), France; Euglena caudata, (?), Mitchell 

 (1928: 29, pis. 4-6), United States. 



The parasite of Euglena caudata so carefully described by Mitchell 

 (1928) has been included here by Karling (1942e). However, since no 

 zoospores were seen its actual relationships are in doubt. 



Pseudosphaerita radiata (Dang.) Sparrow 

 Aquatic Phycomycetes, p. 640. 1943 

 Sphaerita radiata Dangeard, Le Botaniste, 2: 54, pi. 2, fig. 20. 1890-91. 



From one to three parasites in the host, variable in position, if one, 

 occurring at the rear of the body, near the nucleus of the host, the host 

 cell becoming completely deformed and its contents being disorganized 

 as the parasite matures; at maturity the globules of the zoospores 

 showing a distinct radiate arrangement in the sporangium, the latter 

 upon the rupture of the host wall being projected from the host cell, the 

 freed biflagellate zoospores becoming narrow at their two extremities 

 and taking the form of a small rod with a globule in the center; resting 

 spore not observed. 



In Cryptomonas, France. 



