SPIROTRICHA, OLIGOTRICHA 663 



Genus Tetratoxum Gassovsky. Slightly compressed; 2 anterior 

 and 2 posterior zones of membranellae ; in the colon of horse. 



P. unifasciculatum (Fiorentini) (Fig. 311, h). 104-168^* by 62- 

 100)u; widely distributed. 



T. escavatum Hsiung. 95-135)u by 55-90)u. 



T. parvum H. 67-98/x by 39-52^. 



Genus Tripalmaria Gassovsky {Tricaudalia Buisson). Adoral zone 

 at anterior end; 2 dorsal and 1 ventral-posterior zones in tuft-form; 

 macronucleus inverted U-shape; in the colon of horse. 



T. dogieli G. (Fig. 312, a). 77-123/x by 47-62^. 



Genus Triplumaria Hoare. Adoral zone; 2 dorsal and 1 ventral 

 cirrose tufts (caudals); skeleton, composed of polygonal plates ar- 

 ranged in a single layer, surrounds the body except the dorsal sur- 

 face; dorsal groove supported by rod-like skeleton; macronucleus 

 elongate sausage-form, with a micronucleus attached to its dorsal 

 surface near middle; about 6 contractile vacuoles arranged in line 

 along dorsal surface of body; in the intestine of Indian rhinoceros. 



T. hamertoni H. 129-207^ long, 65-82m thick, 4-39/x broad; endo- 

 commensal in the intestine of Rhinoceros unicornis in Zoological 

 Garden in London. 



Genus Cochliatoxum Gassovsky. Adoral zone near anterior end; 

 3 additional zones, 1 antero-dorsal, 1 postero-dorsal and 1 postero- 

 ventral; macronucleus with curved anterior end; in the colon of 

 horse. One species. 



C. periachtum G. (Fig. 312, b). 210-370^ by 130-210^. 



Genus Ditoxum Gassovsky. Large adoral zone near anterior end; 

 2 dorsal (anterior and posterior) zones; macronucleus curved club- 

 shaped; in the colon of horse. 



D.funinucleum G. (Fig. 312, c). 135-203/x by 70-101^. 



Genus Troglodytella Brumpt and Joyeux. Ellipsoid; flattened; 

 adoral zone; 3 additional zones (anterior zone continuous or not con- 

 tinuous on ventral surface; posterior zone continuous on dorsal 

 surface; between them a small zone on each side); skeletal plates in 

 anterior region; macronucleus L-form; contractile vacuoles in 2 cir- 

 cles; in the colon of anthropoid apes. 



T. abrassarti B. and J. (Fig. 312, d-j). About 145-220m by 120- 

 160iu; in the colon of chimpanzees. Reichenow (1927) distinguished 

 var. acuminata on the basis of drawn-out posterior end, which was 

 found by Swezey (1932) to be a variant of T. abrassarti. 



T. gorillae Reichenow. 200-280m by 120-160/^; in the colon of 

 gorilla; with anterior zone not reaching the right side. 



