PRELIMINARY NOTE ON NEW PROTOZOAN PARASITE. 403 



The parasites occur in the coelomic cavities of one genus of 

 Burmese earthworms, Eutyphceus and most commonly in E. 

 foveatus. They are found in smaller numbers and more rarely in 

 E. spinulosus, rams, and peguanus. One hundred per cent, of 

 the E. joveatus examined during a period extending over four 

 years have been infected. In the majority of worms of the last 

 named species, large numbers of parasites are found, masses 

 containing 20-40 individuals being not uncommon. The largest 

 groups of parasites occur in segment three, the majority of which 

 are attached to the large nephridial masses of this segment. 

 Other locations are: under the nerve cord in segment four, and 

 on the septa or parietes of segments four to twenty. Those 

 found posterior to segment nine are almost always less than one 

 millimeter in length. 



AIKINETOCYSTIS siNGULARis, n. gen., n. sp. 

 Diagnosis. 



Uninucleated protozoa parasitic in the ccelomic cavity of 

 certain earthworms of Burma; body cylindrical or columnar with 

 a characteristic, regularly dichotomous branching at the at- 

 tached end; fixation to the host by means of sucker-like bodies 

 borne on the ultimate branches; nucleus with a single ec- 

 centrically placed endosome. 



Additional Observations. 



Pairs of animals are frequently found attached to each other 

 near the rounded free ends. Among the larger sized forms such 

 pairs are nearly as common as single animals, but do not occur 

 among the smaller parasites. Groups of three to eight animals 

 similarly adherent to each other are also found. Attempts to 

 pull apart the attached animals have always resulted in breaking 

 one or both of the animals near the place of attachment. How- 

 ever no evidence of organic connection between members of a 

 pair or group has been found. 



Monocystid-like spores of typical pseudo-navicella form in 

 masses visible to the naked eye are sometimes present in segments 

 three to five. In other specimens in which such masses are not 

 visible similar spores can almost always be found by scraping the 

 body wall of the segments just mentioned. The spores are of 



