T 



Chapter 36 

 Order 1 Holotricha Stein (continued) 



Suborder 5 Thigmotricha Chatton and Lwoff 



HE majority of the ciliates placed in this suborder are parasites 

 or commensals of molluscs. They possess thigmotactic cilia with 

 which they attach themselves to the host body. Though appearing 

 heterogeneous, Chatton and Lwoff (1949) maintain that there is a 

 phylogenetic unity among them, which condition has been brought 

 about by degenerative influence because of similar conditions of 

 habitat. Taxonomy (Jarocki and Raabe, 1932; Chatton and Lwoff, 

 1949). 



Following Chatton and Lwoff (1939), the suborder is here divided 

 into seven families: 



Family 1 Conchophthiridae 

 Family 2 Thigmophryidae (p. 776) 

 Family 3 Hemispeiridae (p. 776) 

 Family 4 Hysterocinetidae (p. 779) 

 Family 5 Ancistrocomidae (p. 780) 

 Family 6 Hypocomidae (p. 784) 

 Family 7 Sphenophryidae (p. 785). 



Family 1 Conchophthiridae Reichenow 



Genus Conchophthirus Stein. Oval to ellipsoid; flattened; right 

 margin concave at cytostomal region, left margin convex; ventral 

 surface somewhat flattened, dorsal surface convex; cytostome on 

 right side near middle in a depression with an undulating membrane; 

 macro nucleus; micro nucleus; contractile vacuole opens through a 

 canal to right side ; in the mantle cavity and gills of various mussels. 

 Species (Kidder, 1934, 1934a; Uyemura, 1934, 1935); morphology 

 (Raabe, 1932, 1934; Kidder, 1934). 



C. anodontae (Ehrenberg) (Fig. 329, a). Ovoid; cytostome in 

 anterior third, with an overhanging projection in front; cytopharynx, 

 surrounded by circular fibrils, continues down as a fine, disten- 

 sible tubule, to near the macronucleus; with peristomal basket; 

 ciliary grooves originate in a wide ventral suture near anterior 

 end; anterior region filled with refractile granules; macronucleus 

 posterior; contractile vacuole between nuclei and peristome, with 

 a slit-like aperture (Fig. 27); 65-125/* by 47-86^; in the mantle 

 cavity, gills and on non-ciliated surface of palps of Elliptio com- 

 planatus; Woods Hole. 



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