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Lambornella stegomyiae 
The formation of external cysts attached to the body of the host has been 
observed in other ciliates parasitic in the body-cavity of Arthropods. According 
to Balbiani (1885), Collinia circulans (Balbiani) Cepede 1910, which lives as 
a parasite in the body-cavity of Asellus aquaticus, after passing through a 
phase of active multiplication in the body-cavity of the host, escapes through 
ruptures in the antennae and attaches itself to the external cuticle of the host, 
or to the surrounding filaments of the alga Cladophora, where it becomes 
encysted. A similar mode of encystment has been observed by Cepede and 
Fig. 6. Lambornella stegomyiae . Dilferent forms of the cysts of this ciliate; m. micronucleus; 
M . macronucleus; W. wall of the cyst. 
Giard (1910) in Perezella pelagica Cepede, a ciliate parasite found in the body- 
cavity of marine Copepods. 
V. Mode of Infection. 
In his note (p. 214), Lamborn records that he has succeeded in infecting 
healthy Stegomyia larvae by keeping them with infected living and dead 
specimens of the larva. Infection is probably acquired through the mouth in 
the case of Lambornella, but it should be mentioned that Balbiani failed to 
infect healthy Asellus by feeding them upon the cysts of Collinia. It is possible 
that the failure was due to the fact that the cysts were unripe. 
