182 The Mastigophora 



Kent, both with a long anterior flagellum, and Macromastix Stokes (Fig. 

 4. 43, C) with a short anterior flagelkim. A lateral membrane (or keel?), 

 which is not an undulating membrane, extends the length of the body 

 in Trimastix. The flagellar equipment of Macromastix resembles that of 

 the chrysomonad genus Prymneshim Massart (Fig. 4. 8, A). Similarly, 

 Chrysochromiilina (Fig. 4. 8, D) is similar to DaUingeria and Trimastix. 

 Perhaps the Trimastigidae should be investigated for possible affinities 

 with the Chrysomonadida. 



Family 2. Tetramitidae. There are four unequal or equal flagella, one 

 or two of which may be trailed. No parabasal body or axostyle has been 

 reported, although a rhizostyle is present in Tetramitus (Fig. 4. 43, K) 

 and Copromastix (Fig. 4. 43, F). A dimorphic cycle involving flagellate 

 and amoeboid stages is known in Tetramitus (29, 110). 



The following genera have been included in the family: Costia Leclerq 

 (7, 59, 269; Fig. 4. 43, D, E), from the skin of fish; Tetramitus Perty (29, 

 110, 153, 245; Figs. 4. 43, K, L, 2. 14, C-E), in which the life-cycle includes 

 amoeboid and flagellate stages; and Tricercomonas Wenyon and O'Con- 

 nor (22, 65, 285; Fig. 11. 2, A-E), from the intestine of man. Enteromonas 

 Fonseca may be an additional valid genus, although Dobell (65) has con- 

 cluded that Tricercomo7ias is merely a synonym of Enteroynonas. How- 

 ever, da Cunha and Muniz (53), as well as Fonseca, have described 

 Entero?nonas intestinalis with one long and two short flagella, and in 

 contrast to Tricercomonas, without any trace of a fourth flagellum or 

 caudal extension. The status of Copromastix Aragao is uncertain. C. 

 prowazeki Aragao (Fig. 4. 43, F) is so similar to Tetramitus rostratus (29, 

 110) that the two flagellates probably should be referred to the same 

 genus. 



Family 3. Streblomastigidae. These parasites of termites {Termopsis), 

 have an unusually slender body with a few spirally wound ridges and an 

 anterior group of four flagella (131, 158). The flagella arise from the 

 anterior tip of the body which can be extended as a slender holdfast 

 organ. The only known genus is Streblomastix Kofoid and Swezy (Fig. 

 4. 43, M). 



Family 4. Retortomonadidae. This family (278) includes Retortomonas 

 Grassi {Embadomonas Mackinnon) (Fig. 4. 43, A, G, H) and Chilomastix 

 Alexeieff (Fig. 4. 43, B, I, J). Both Retortomonas (18, 150, 187, 278) and 

 Chilomastix (149, 198, 278) possess a cytostomal groove, in the margin of 

 which a cytoplasmic fibril extends across the anterior end and posteriorly 

 along each side. A true parabasal body is lacking. The significance of a 

 differentiated intracytoplasmic "band/' sometimes apparent just beneath 

 the right limb of the peristomial fibril (149), is uncertain. In both genera, 

 a single trailing flagellum emerges from the cytosomal groove. Retorto- 

 monas is distinguished from Chilomastix by the presence of one instead 

 of three anterior flagella. The cytostomal flagellum in Chilomastix has 

 been interpreted as part of an undulating membrane by Nie (198) and 



