642 FAMILY: CEYPTOBIIDiE 



seems more probable that he was dealing with some other flagellate, possibly 

 a Cercomonas. Hovasse (1924) has given the, name Trypanoplasma sagittce 

 to a form he has found in the intestine of a little marine worm belonging 

 to the genus Sagitta. 



C. Blood Forms of Fish. 



Laveran and Mesnil (1901c) created the genus Trypanoplasma for a 

 flagellate they discovered in the blood of the fresh-water rudd, Leuciscus 

 enjthrojjhthahnus, which they named T. horreli (Fig. 151). Since that date, 

 a number of similar forms have been discovered in the blood of fresh- 

 water fish. Curiously enough, no one has yet described an intestinal 

 form from fresh-water fish, though such forms have been seen in marine 

 fish, in which, however, the blood forms do not occur. Structurally, the 

 blood flagellates are similar to those of snails and the intestine of marine 

 fish, so that strictly they should be included in the genus Cryptohia. 

 The blood forms have been so long known by the name Trypaiioplasfna 

 that it seems better to retain this name for them provisionally. They 

 are carried from host to host by leeches, while the other forms have a 

 different method of transmission. In the case of the intestinal flagellates 

 of fish, and possibly those of snails, it might be expected that encysted 

 forms would occur. Such, however, have not yet been described. Future 

 investigation may, however, reveal encysted forms, in which case the re- 

 tention of the name Trypanoplasma for the blood forms would be justified. 

 The possibility of a difference in life-cycle was suggested by Woodcock 

 and Lodge (1921). 



The various tryj)anoj)lasms of fish resemble one another very closely, 

 so much so that Keysselitz (1906), who studied these flagellates in many 

 species of fresh-water fish, came to the conclusion that they all belonged 

 to the species T. horreli. Other observers, however, have given specific 

 names to the forms occurring in different fish. 



The following species have been described: 



T. horreli Laveran and Mesnil, 1901: Leuciscus eryihrophihahnus (rudd). 



T. cypriniVlGhn, 1903: Carassius vulgaris (carp), C. auraiius (goldfish). 



T. varium Leger, 1904: Cobitus barbatula (loach). 



T. guernei Brumpt, 1905: Coitus gohio (bull-head). 



T. barbi Brumpt, 190G: Barbus fluviatilis (barbel). 



T. abraviidis Brumj)t, 1906: Abraviis hrama (bream). 



T. Initiw Brumpt, 19C6: Salmo fario (trout) = T. valentini Gauthier, 1920: 



Salmo fario. 

 T. sp. Rodliain, 1907: Labeo macrostoma 

 T. gurneyorum Minchin, 1909: Esox lucius (pike). 

 T. Clarice Mathis and Leger, 1911: Clarias macrocephnlus. 

 T. sp. Mathis and Leger, 1911: Monopterus javancnsis. 

 T. heysselitzi Minchin, 1909: Tinea tinea (tench). 

 T. sp. Tanabe, 1924: Misgurnus anguillicaudatus. 

 T. nince koM-yaJcimov Yakimofl, 1925: Silurus glaris. 



