392 
Philippine Journal of Science 
1919 
rounded in shape, centrally placed, and measures 6 y to 7 y in 
diameter. The micronucleus, which lies in its vicinity, is also 
rounded and measures only 1 y in diameter. The cysts are oval. 
Balantidium falcifarum 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 y to 4.6. y in diameter. The 
size of the organism is from 30 y to 35 y by 10 y to 15 / a . Ac- 
cording to Walker it sporulates on artificial media. The cysts 
are round and single-walled and their contents granular. 
Balantidium orchestis Watson (Kamm).(l3) 
Parasitic in the alimentary tract of Orchestia agilis and Talor- 
chestia longicornis. The body of this species is ovoidal or ellip- 
soidal and measures from 300 /a to 360 y in length with a width 
of from 180 y to 220 y. 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. 
Balantidium italicum 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 diarrhoeic 
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 y by 14 y and those grown in agar, 33 y by 25 y. 
Fantham, Stevens, and Theobald (3) mention species of Balan- 
tidium occurring in polychsete annelids, and various authors have 
described balantidia from the human intestinal tract to which 
