MORPHOLOGY AND TAXONOMY OF MASTIGOPHORA 285 



chlorophyll, is green or red (hematochrome) in color. Reproduction 

 by longitudinal division during free-swimming or quiescent periods. 

 Fresh and salt water, more commonly the former. 



Family 2. Astasiidae, Biitschli. — Here we include all colorless 

 forms of Euglenida ha^•ing only one flagellum. The body is usually 

 ellipsoidal, or swollen at the posterior end and metaboly in charac- 

 teristic but not invariable. The periplast is usually conspicuous 

 and may be ornamented by one or more ridges (carinse) as in Peta- 

 lomonas. A cytopharynx system is similar to that in Euglenidse 

 and a stigma is present in at least one exceptional species (Astasia 

 ocellafa). Movement by creeping or free-swimming; when creeping 

 the flagellum is usually extended straight ahead, the tip, or free 

 end of the axial filament alone in vibration. Reproduction as a 

 rule is by longitudinal division while free-swimming. 



Family 3. Heteronemidse.— Colorless forms of Euglenida with 

 2 flagella, 1 usually directed posteriorly. The vacuole system is 

 complex, stigmata are absent but param\'lum is usually present. 

 Body ellipsoidal sometimes metabolic but more often rigid with 

 thick periplast which is often ornamented with longitudinal or spiral 

 ridges. Movement creeping and free-swimming. 



Order YL CHLOROMONADIDA, Klebs. 



A very artificial group of comparatively rare forms with obscure 

 affinities. The vacuole system is similar to that of the Euglenida 

 but with starch, grass-green chromatophores of discoid al form, in 

 chlorophyll-bearing t\pes. The cortical protoplasm easily becomes 

 vacuolated, and pseudopodia are present in one genus (Thaumato- 

 mastix). Trichocyst-like rods are present in (Jonyostomum. Little 

 is known about their life histories. 



Class II. ZOOMASTIGODA, Doflein. 



The animal flagellates have no chromatophores, no chlorophyll 

 and no paramylum granules. The vacuole is a simple vesicle, and 

 cortical differentiations are less extensive and of a different type 

 from those of the Phytomastigoda. On the whole the group includes 

 small forms of relatively less complexity than those of the preceding 

 class and other forms of remarkably great complexity. In one 

 respect particularly, the group shows more complicated difteren- 

 tiations than do the plant flagellates. This has to do with the 

 kinetic and locomotor apparatus, where specializations are complex, 

 especially in the parasitic types. In other respects the animal 

 flagellates parallel the types already outlined, especially as regards 

 form of the body, number and specialization of flagella, and life 

 history. Colony forms are common, particularly the branching 



