780 PROTOZOOLOGY 



P. bacteriophilum Miyashita (Fig. 330,/). Elongate oval; 70-130/* 

 by 30-45/*; sucker oval and large, about 50/* in diameter; macronu- 

 cleus ellipsoid; endoplasm with numerous rods (symbiotic bacteria?) ; 

 in the freshwater oligochaete, Criodrilus sp. 



Family 5 Ancistrocomidae Chatton and Lwoff 



Genus Ancistrocoma C. and L. (Parachaenia Kofoid and Bush). 

 Elongate pyriform with attenuated anterior end; somewhat flat- 

 tened dorso-ventrally; a contractile suctorial tentacle at the anterior 

 tip, which is used for attachment to the epithelium of host, and 

 which continues internally as a long curved canal; longitudinal cilia- 

 tion on dorso-lateral and ventral sides, beginning at the anterior 

 end; parasitic in the gills and palps of mollusks. Taxonomy (Kozloff, 

 1946b; Chatton and Lwoff, 1950). 



A. pelseneeri C. and L. (Parachaenia myae Kofoid and Bush) (Fig. 

 331, a). Body 50-83(62)/* by 14-20(16)/* by 11-16(12.5) a*; 14 ciliary 

 rows on dorso-lateral and ventral surfaces; five rows on the ventral 

 side extend only 2/3 from the anterior end; tentacle continues in- 

 ternally for about 2/3 of body, curved; macronucleus sausage- 

 shaped; a single micronucleus; on the gills and palps of mussels: 

 Mya arenaria, M. irus, M. inconspicua, M. nasuta, M. secta, Crypto- 

 mya californica (Kozloff, 1946b). 



Genus Hypocomagalma Jarocki and Raabe. Ovoid or pyriform 

 with attenuated anterior end; asymmetrical; 22-24 ciliary rows 

 which do not reach the posterior end; a suctorial tentacle at the an- 

 terior end; on mollusks. 



H. pholadidis Kozloff (Fig. 331, b). 63-89/* by 18-25/* by 16-21/*; 

 anterior end bent ventrally; 24 or 25 ciliary rows; one or more con- 

 tractile vacuoles; macronucleus sausage-shaped; a single micronu- 

 cleus; parasitic in the epithelium of the gills and palps of Pholadidea 

 penita (Kozloff, 1946b). 



Genus Syringopharynx Collin. Elongate ovoid, narrowed ante- 

 riorly; a suctorial tentacle at anterior end; 14 ciliary rows (six dorsal, 

 six ventral and two lateral) ; on molluscs (Collin, 1914). 



S. pterotrachae C. Body 55/* by 25/*; macronucleus elongate band; 

 on the gills of Pterotracha coronata (Chatton and Lwoff, 1950). 



Genus Goniocoma Chatton and Lwoff. Ovoid with attenuated an- 

 terior end; end of suctorial tentacle extremely slender; 27-29 ciliary 

 rows; of the 14 dorsal rows, the median row is very short and the 

 rows on either side of it are progressively longer; ventral rows pass 

 over the posterior end and terminate on dorsal surface; on the gills 

 of molluscs. 



