C YSTO TR YPA NEM 



397 



A. Forms carefully studied : — 



Snout long, no free flagellum forms like T. dimorphon : — 



1. Trophonucleus round — Rhynchoidomonas Patton, 



1910. 



2. Trophonucleus elon§2ite-—Cystotrypanosoma Rou- 



baud, 1911. 



B. Forms not yet fully studied: — 



We still retain the old term Trypanosoma sensil lato for these 

 forms, pending further investigation, and divide them into: — 

 I. Trypanosomes of Hirudinea. 

 II. Trypanosomes of Arachnida. 

 III. Trypanosomes of Hexapoda. 



Forms Carefully Studied. 

 Genus Rhynchoidomonas Patton, 1910. 



Definition. — CystotrypanecB with large kinetonucleus situated on 

 the aflagellar side of the rounded trophonucleus, with distinct 

 imdulating membrane and with the aflagellar end drawn out 

 considerably. 



Rhynchoidomonas lucilise Patton, 1910. 



This parasite is found in the Malpighian tubes of Lucilia serenis- 

 sima Walker, and Musca nebula Fabricius, in India. It moves by 

 sharp jerking movements, and has no free flagellum, but a pointed 

 flagellar extremity and a pointed aflagellar extremity. The kineto- 

 nucleus is large and circular, while the trophonucleus is also large. 

 The cytoplasm contains many chromatoid granules. 



Genus Cystotrypanosoma Roubaud, 191 1. 



Definition. — Cystotrypanece with small terminal kinetonucleus 

 situate on the aflagellar side of an elongated trophonucleus. 

 There is no free flagellum. It gives rise to pyriform cysts. 



Cystotrypanosoma intestinale Roubaud, 1911. 



This parasite is found in the intestine of a species of Lucilia at 

 Bamako in French West Africa. 



Forms not yet Fully Studied. 

 Trypanosomes belonging to the invertebrate and not due to the 

 sucking of contaminated blood have been found in the tsetse-fly, in 

 mosquitoes, in ticks, and perhaps in leeches, but it is doubtful about 

 the last named. 



The presence of the Herpetomonas, Crithidia, and Trypano- 

 soma in blood-sucking Arthropods may, therefore, be peculiar 

 to those animals, or only acquired from their hosts. Hence it is 

 quite possible for serious errors to arise in working out the life-history 

 of these parasites, especially as infection of the blood-sucker may 

 come from the eggs. 



