EXPLANATION OF PLATE 2 



Crithidia leptocoridis sp. nov., preflagellate stages 



Figs. 29-32. Multiple fission forms of the stomach phase which are intra- 

 cellular apparently and show the probable origin of the merozoites. 



Fig. 33. An early plasmodial form in the stomach. 



Figs. 34-36. Plasmodial forms containing very small merozoites. Each 

 merozoite shows the nucleus in posterior end and the "kinetonucleus" in the 

 anterior end. 



Fig. 37. An unusually large plasmodial form from the stomach. Not all 

 of the merozoites are the same size. The more mature ones show the vesicular 

 nucleus in the posterior end and the "kinetonucleus" surrounded by a light 

 area in the anterior end. The rhizoplast can also be seen in the larger mero- 

 zoites. 



Fig. 38. A merozoite which has escaped from Plasmodium and has under- 

 gone a rapid longitudinal division apparently. 



Figs. 39-45. Merozoites in different stages of development. With one 

 exception all these show both the nucleus, "kinetonucleus," rhizoplast and 

 the characteristic light area about the "kinetonucleus." 



Fig. 46. A peculiar structure which is seemingly due to rapid longitudinal 

 division and a subsequent failure on the part of the resulting forms to separate 

 at once. 



Figs. 47-51. A series of flagellates from stomach showing the flagellum 

 present which is just beginning to separate from body proper and to straighten 

 out. Figure 50 shows the flagellum bent back upon the body almost the entire 

 length. An "axostyle" is present in figure 51. 



Fig. 52. Almost mature flagellate from stomach. Nucleus with karyo- 

 some, rhizoplast, "axostyle" and a myonemic fiber connected with the 

 flagellum. 



Fig. 53. Almost mature flagellate from stomach. Nucleus with three 

 large chromosome-like granules. ' ' Axostyle ' ' present with several chromidia 

 in close proximity. 



Fig. 54. A more elongate flagellate, network in nucleus together with a 

 central karyosome, rhizoplast and "axostyle." A myonemic fiber lateral to 

 "kinetonucleus" connected with the flagellum. 



Fig. 55. Mature flagellate from mid-intestine. Light area about the nucleus 

 extended forward along flagellum and posterior to the nucleus, myonemic lines 

 outline this area. ' ' Axostyle ' ' present. 



Fig. 56. Mature flagellate from mid-intestine. "Axostyle" has a wavy 

 appearance and this is an edge view of the parasite. 



[18] 



