visible in most Herpetomonas forms, so that practically 

 a spindle-shaped flagellate, with anterior blepharoplast, 

 is a Herpetomonas. The undulating membrane is, if 

 present, only slightly developed and difficult to see. 

 There is, therefore, little, if any difference, between a 

 Herpetomonas and the forms taken on by trypanosomes 

 in culture. Further, the Herpetomonas assumes a 

 resting gregarine form, attached to epithelial cells of 

 the gut by their flagella, e.g., in the pyloric dilatation of 

 the larva, developing into free forms in the mid-gut 

 of the mosquito. 



1. H. muscae-domesticae (Burnett) in the gut 

 of house flies, e.g., Muse a domestic a, Homalomyia 

 scalaris, etc. Also a similar one in the gut of 

 Stomoxys calcitrans. 



2. H. sarcophagae (Prowazek), in Sarcophaga 

 haemorrhoidalis, the meat-fly. 



3. H. algeriense, in the gut of C. pipiens and S. 

 calopus. It is 12 by 2*5/4, flagellum 4'5/ A , blepharo- 

 plast posterior. Non-motile forms also occur, 5*5/4 

 in diameter, with flagellum 17/4. Resting (gregarine) 

 forms without flagellum also occur. 



4. H. culicis(Novy). In C. pipiens, etc. Actively 

 motile: (i) long, 25-35/4 by 1-1*5/4; flagellum, 

 5-10/4; (2) medium, 15-25 by 1*5-2*5/4; flagellum, 

 3-8/4 (male type) ; (4) Wide form, 20 by 2*5-3/4 ; 

 flagellum, 5-8/4 (female type). They all have a double 

 body (diplosome) situate posteriorly (Fig. in). 



These forms also become spherical, about 5/4 in 

 diameter. H. culicis can be grown on Novy and 

 McNeal's medium. The forms in culture resemble 

 those in the mosquito. 



5. H. pulicis. In the gut of fleas ; P. cleopatrae 

 (Balfour) and Ctenocephalus felis (Patton). 



6. H. subulata. In Tabanus glaucopis and Hue- 



