PARASITES OF PROTOZOA 1069 



development of the parasites has been mistaken for a phase of the 

 cycHcal development of the host. In the tintinnids these errors were 

 first pointed out by Duboscq and Collin (1910); in the Radiolaria by 

 Chatton (1920b). 



Chatton (1920b) established the genus Duhoscquella for the para- 

 site of tintinnids, and recorded D. tint'mnkola as occurring in Codonella 

 galea, Tint'ninopsis campanula, and Favella (as Cyttarocylis) ehren- 

 bergii. In the last ciliate, Duboscq and Collin (1910) observed the 

 parasite in abundance at Cette. It is a subspherical body which grows 

 to a large size (100 |j) without apparent inconvenience to the host. Re- 

 peated division gives rise to a dense mass of gametocytes, each of which, 

 after ejection from the host, undergoes two divisions inside or outside 

 of the host, to produce biflagellate gametes. Hofker (1931) found 

 Duhoscquella t'mtinnicola in Favella ehrenhergn and F. helgolandica. 



Although the enigmatic organism described by Campbell (1926) as 

 Karyoclastis tintinni is apparently not a dinoflagellate, it may be men- 

 tioned here because of its occurrence in this same group of ciliates. 

 Campbell found it to be primarily an intranuclear parasite of Tintin- 

 nopsJs nucula, but, unlike most other described nuclear parasites, it has 

 a cytoplasmic phase. In the macronucleus the parasites occur as numerous 

 small bodies, each with a gray-staining mantle, a clear central area, and 

 within a central granule which undergoes division. The parasites mul- 

 tiply within the nucleus, then the membrane partially disintegrates, 

 and the parasites emerge and form a cloud-like mass in the cytoplasm. 

 Campbell noted that the parasites are distinct in structure from Nucleo- 

 phaga and Sphaerita. Further investigation is necessary to elucidate the 

 complete life cycle and establish the systematic relationships of Karyo- 

 clastis. Hofker (1931) found a resemblance to Karyoclastis in round 

 bodies associated in the test, in some instances, with Tintinnopsis fim- 

 briata; but he recognized the possibility that their occurrence was the 

 result of a fragmentation phenomenon. 



Chatton (1920a, 1920b) pointed out that the so-called anisospores, 

 or gametes, in Thalassicolla, Sphaerozoum, and Collozoum (Brandt), 

 the origin of which in the first genus from intracapsular plasmodial 

 masses was described by Hovasse (1923a), belong not to the radiolarians 

 but to the parasitic dinoflagellates similar to Syndinium of the pelagic 

 copepods. Chatton (1923) proposed the genus Merodinium for these 



