900 PROTOZOA AND OTHER ANIMALS 



Of these only Portunus depurator developed a heavy infection and died. 

 Some were naturally immune, the serum agglutinating and destroying 

 the ciliates. In others the serum was not toxic in vitro, but the ciliates 

 were arrested in certain lymphatic spaces, killed, and phagocytized. 



Accidental parasitism of a nymph of the hemipteran Nepa cinerea 

 was reported by Mercier and Poisson (1923). A species of Colpoda had 

 invaded the body, probably through a wound in the integument, and 

 produced a tumor the size of a pinhead on the lateroventral surface of 

 the metathorax. The tumor extended part inside and part outside of 

 the body, and in it ciliates were numerous. Large ones contained nu- 

 merous inclusions, especially phagocytized amoebocytes. There were 

 also very small ones with no inclusions; these were believed to be nour- 

 ishing themselves by absorption of dissolved substances. Though locally 

 destructive, the parasite did not prevent growth of the nymph up to the 

 imaginal molt, when it was killed by the observers. 



Instances of accidental parasitism by Protozoa have been noted in 

 sea urchins. Lucas (1934), in examining Bermuda sea urchins, en- 

 countered transient Protozoa in the body fluids. She stated that these 

 "were normally free-living forms, which probably gained entrance 

 through the water-vascular system, and gave no evidence of coloniza- 

 tion." Andre (1910) reported Euplotes char on in certain abundance 

 in the perivisceral fluid of the sea urchin Echinus esculentis, as well as 

 on the surface of the host. Accidental invasion of the body cavity of 

 these marine echinoderms is apparently not infrequent. 



Warren (1932) studied at Pietermaritzburg, Natal, a ciliate which 

 possibly, according to his account, was a facultative parasite, in the 

 common garden slug Agriolimax ag rest is. He considered it to belong 

 to a new genus and species, Paraglaucoma limacis. Kahl (1926) had 

 already established a genus Paraglaucoma for P. rostrata, found in moss 

 in Germany; later he found the species in moss from California and 

 Wisconsin. Apparently Warren knew nothing of Kahl's work, but the 

 two ciliates appear similar. The length (60-80 pi) as reported by Kahl 

 (1931) is greater than that usual in Warren's form (40 \\ in the free- 

 living form; mean lengths 41-65 m in the parasitic form); but in 1926 

 Kahl had reported the length as 45-55 p. Warren did not report the 

 posterior bristle which Kahl observed. The species also resembles 

 Glaucoma maupasi Kahl, 1926, the ciliate Maupas (1883) described 

 as G. pyriformis. 



