392 Philippine Journal of Science 1919 



rounded in shape, centrally placed, and measures 6 p to 7 /» ifi 

 diameter. The micronucleus, which lies in its vicinity, is also 

 rounded and measures only 1 p in diameter. The cysts are oval. 



Balantidinm falcif arum Walker. (12) 



Found in the large intestine of the frog Rana palustris Le- 

 conte. The body is falciform and oval in cross section. The 

 anterior end of the body is narrow and truncated obliquely to 

 the right. The peristome is limited to the anterior end. The 

 cytopharynx is very short. The meganucleus, lying either in 

 the middle of the body or a little posteriorly, has an oval or 

 rounded shape. It measures 3.8 p. to 4.6 p in diameter. The 

 size of the organism is from 30 /* to 35 ^ by 10 p to 15 p. Ac- 

 cording to Walker it sporulates on artificial media. The cysts 

 are round and single-walled and their contents granular. 



Balantidinm orchestis Watson (Kamm).(13) 



Parasitic in the alimentary tract of Orchestva agilis and Talor- 

 chestia longicornis. The body of this species is ovoidal or ellip- 

 soidal and measures from 300 p to 360 p in length with a width 

 of from 180 p to 220 p. The meganucleus is ellipsoidal. The 

 micronucleus, which is small, lies close to the meganucleus. The 

 peristome is small and inconspicuous and leads into a short, 

 slender oesophagus. There is a single contractile vacuole at the 

 posterior end. 



Balantidium coli var. hondurense Barlow. 



This is described by Barlow as differing from Balantidium coli 

 in that the cilia are not arranged in rows ; there is no contractile 

 vacuole ; and the cytopyge, or anus, is contractile. The micronu- 

 cleus, Barlow says, is difficult to demonstrate. This is an in- 

 teresting form that requires further study. 



Balantidinm italicnm Sangiorgi and Ugdulena. (8) 



This is described by Sangiorgi and Ugdulena as very similar 

 to Balantidium minutum Schaudinn, the only differences being 

 the eccentric position of its nuclear apparatus and the inconstant 

 relative position of the micronucleus with regard to the mega- 

 nucleus. This organism has been found in human diarrhceic 

 stools. It has been successfully cultivated in peptone water and 

 agar-agar media. The average size of those grown in peptone 

 water is 31.5 n by 14 p and those grown in agar, 33 p by 25 p. 



Fantham, Stevens, and Theobald (3) mention species of Balan- 

 tidium occurring in polychaste annelids, and various authors have 

 described balantidia from the human intestinal tract to which 



