2 University of California Publications in Zoology [Vol. 20 



forms belonging to the family Trichonymphidae, such as Trichonympha 

 Leidy, which are among the most highly specialized members of the 

 Protozoa. 



Along with these more complex forms are others which, while 

 simpler in structure, yet show certain peculiar morphological char- 

 acteristics that distinguish them as a group apart from other intes- 

 tinal flagellates. Among these we find Pyrsonympha vertens and 

 Dinenympha gracilis described by Leidy in 1881. 



Later investigators have added both to the number of genera and 

 of species of these peculiar flagellates. 



Material 



The material for these studies was obtained from one species of 

 termite which is abundant on the University campus at Berkeley. 

 This is Termopsis angusticollis Walker and was identified for us by 

 Dr. Nathan Banks of the Museum of Comparative Zoology at Cam- 

 bridge, Mass. Most of this material was obtained from the decayed 

 trunk of an oak tree in Strawberry Canon. Many of the same species 

 were obtained during the swarming season from the piles on TMeiggs 

 Wharf, San Francisco, by Dr. A. D. Drew of the Public Health 

 Service. 



These termites are large and show an infection of about one hun- 

 dred per cent, soldiers, workers and males of the colony being infected 

 alike. The amount of. infection in a single individual is relatively 

 enormous. The abdomen is large and nearly filled by the greatly 

 swollen intestine. This distension is caused by the vast numbers of 

 parasitic and commensal protozoans which fill the lumen of the intes- 

 tine. When this is opened a thick milky fluid exudes. Under the 

 lens this is found to be composed of great quantities of these small 

 forms, thickly massed together, along with fragments of wood upon 

 which the host, as well as some of its commensals, feeds. 



In Termopsis angusticollis four different species of large protozoans 

 are invariably present, sometimes about equal in number or with one 

 predominating over the others. In addition to these there are usually 

 present minute forms of two, sometimes three different species of 

 flagellates, the whole forming a complex of organisms wonderful both 

 for variety and amount. Of these forms the two largest species 

 belonging to the family Trichonymphidae and a third species belong- 

 ing to the Polymastigidae, will be reserved for discussion in later 



