166] The Classification of Lower Organisms 



Family 2. Streblomastigida [Streblomastigidae] Kofoid and Swezy in Univ. Cali- 

 fornia Publ. Zool. 20: 15 (1919). The only known species is Strehlornastix Strix, a 

 slender spirally twisted organism with four anterior flagella, free-swimming or at- 

 tached in the gut of the termite Termopsis. The significance of the epithet Strix (a 

 Greek noun meaning screech owl) as applied to this species is not clear. 



Family 3. Dinenymphida [Dinenymphidae] Grassi in Atti Accad. Lincei ser. 5. 

 Rendiconti CI. Sci. 20, 1° Semestre: 730 (1911). Elongate flagellates, the four or 

 eight anterior flagella adherent to the body and spirally twisted with it, free at their 

 distal ends. Often beset with spirochaets, which have been mistaken for additional 

 flagella; the family has been misplaced in order Hypermastigina. Dinenympha and 

 Pyrsonympha in termites; Saccinohaculus in the wood roach Cryptocercus. 



Family 4. Oxymonadida [Oxymonadidae] Kirby in Quart Jour. Micr. Sci. n. s. 72: 

 380 ( 1928) . Flagellates with radially symmetrical bodies including two or more neuro- 

 motor systems, entozoic in termites of subfamily Kalotermitinae. Each pear-shaped 

 cell of Oxymonas has one nucleus and two neuromotor systems (Kofoid and Swezy, 

 1926). In Microrhopalodina {Proboscoidella) each cell contains a whorl of nuclei, 

 each with its separate neuromotor system (Kofoid and Swezy, 1926; Kirby, 1928). 

 These organisms are superficially closely similar to the Calonymphida, from which 

 Kirby distinguished them. 



Family 5. Trepomonadida [Trepomonadidae] Kent Man. Inf. 1: 300 (1880). 

 Family Hexamitidae Kent op. cit. 318. Distomata Klebs in Zeit. wiss. Zool. 55: 329 

 (1893). Family Distomataccae Senn in Engler and Prantl Nat. Pflanzenfam. I Teil, 

 Abt. la: 148 (1900). Flagellates each with two nuclei and two neuromotor systems. 

 In most examples, each half-cell is dorsiventral, and the whole isobilateral, with two 

 cytostomes. Most of the genera, Trepomonas, Gyromonas, Trigonomonas, are free- 

 living in fresh or foul waters and have been little studied. Hexamita occurs both free- 

 living and entozoic, in roaches and in all classes of vertebrates; the cells have eight 

 flagella {Octomitus Prowazek and Urophagus Moroff are synonyms). In Giardia 

 the half-cells are asymmetric, and the whole cells dorsiventral, with one cytostome. 

 There are several species, serious pathogens in mammals. The valid name of the 

 species in man, usually known as G. Lamblia, appears to be G. enterica (Grassi) 

 Kofoid (1920). 



Order 3. Trichomonadina Grasse Traite Zool. 1, fasc. 1: 704 (1952). 



Order Trichomonadida Kirby in Jour. Parasitol. 33: 215, 224 (1947), preoc- 

 cupied by family TRiCHOMONADroAE Wenyon (1926). 



Flagellates of the general nature of the Polymastigida having in each neuromotor 

 system one trailing flagellum; axostyle present, rigid, apparently not homologous 

 with the flagella; parabasal body present, disappearing during mitosis. Entozoic, the 

 majority of the species, to the number of fully 150, occurring in termites. 



The base of the trailing flagellum may be underlain by a cresta, a more or less 

 prominent body distinct both from parabasal body and from axostyle. The trailing 

 flagellum may be grown fast to the cell membrane and converted into an undulating 

 membrane; in this case it is underlain by a rod called the costa, apparently homolo- 

 gous with the cresta (Kirby, 1931). 



Nuclear and cell division have been described in Trichomonas by Kuczynski 

 (1914), Kofoid and Swezy (1915, 1919; the Trichomitiis described in the latter 

 year is a Trichomonas) and Hinshaw (1926). The centrosome (or a combined cen- 

 trosome and blcpharoplast, the centroblcpharoplast of Kofoid and Swezy, 1919) lies 



