PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 1015 



the mistakes of others. But I think that it would be desirable to com- 

 mence any new researches on this subject by a study of the parasites 

 of the American Leitcotermes flaripes. It is quite possible that under 

 the name of Tr. agilis a number of different species or varieties haye 

 been described and therefore each description might be perfectly correct 

 in itself. 



In the remaining figures (19-30) of this Plate you will find the re- 

 production of the parasites that Leidy considered as young forms or 

 immature stages of Tr. agilis. Please give this subject your kind atten- 

 tion. Excepting perhaps figure 30, which seems to me to constitute 

 the Microjoenia hexamitoides of Grassi, all the others present an almost' 

 identical constitution, well pictured in his figvxre 11 (my figure 19). 

 Grassi, Biitschli, Delage rejected the conception of Leidy, and C. Fran§a 

 created in 1914 the genus Leidya for his L. metchniJcowi. 



The genus Leidya has the following characteristics : nucleus situated 

 in the anterior third of the body of the parasite, flagella inserted on a 

 double spiral band, starting from the anterior extremity and crossing 

 the body in opposite directions. Keeping these fundamental character- 

 istics I was obliged to introduce a small modification, that is to say, 

 that the flagella envelop the body in the whole or part of its 

 extension. 



You will easily see in Plate 169, figures 31-40, the reason of this modi- 

 fication. Fom: species of Leidya parasitize the intestine of Leucoternies 

 indicola : L. meichnikowi of Fran5a, and L. annandalei, L. kemfi and 

 L. campanula all of which I have studied. With two of them I associated 

 the names of the distinguished zoologists Annandale and Stanley Kemp. 

 All these parasites present a vivid progressive movement and their 

 anterior part is more mobile ; the first three easily take circular forms 

 and all present also an interesting helicoidal movement following the 

 direction of their spiral turns. Their anterior flagella are shorter but 

 it seems that they have all an identical disposition and there is no place 

 to describe the siderophile formation giving insertion to the anterior 

 flagella of L. metclinikowi of Franfa. In stained preparations one can 

 easily distinguish the basal granules giving origin to the flagella. They 

 are situated in the inferior face of the spiral band, excepting on the 

 anterior part, which, when it is elongated, changes the situation of 

 these granules from inferior to interior. My last three species, and 

 specially L. ccnnpaniila, show a curious contractile movement, beginning 

 in the basal insertion of the spira and permitting the elongation of the 

 jongitudinal axis of the parasite. The animal progresses thus in a 

 shaky way. 



