MORPHOLOGY AND TAXONOMY OF MASTIGOPHORA 207 



often filled with carbohydrates, and Cyathomonas are colorless and 

 live as saprophytes the latter also taking in bacteria, other small 

 protozoa and algse. Yellow chromatophores are present in Crypto- 

 monas and ChrysideJhi, the latter symbiotic with Radiolaria, Fora- 

 minifera and other marine animals. Rhodomonas has red, Chro- 

 omonas and Cyanomonas blue, Cryptochrysis brown or olive green, 

 chromatophores. Reproduction by longitudinal division occurs in 

 the motile stages or during resting phases, the latter sometimes 

 resulting in Palmella-like small aggregates which quickly break up. 

 The life histor\' is practically unknowai for any species and the 

 finer cytological structures equally so. 



Family 2. Nephroselmidae, Pascher.— Here the characteristic fur- 

 row is equatorial thus imparting a bean- or kidney-shape to the 

 cells. The two fiagella arising from the furrow are thus apparently 

 lateral, one being directed forward, the other backward. 



Sub-order 2. Phaeocapsina, Pascher. 



This group of Cryptomonadida corresponds to the Chrysocapsina 

 group of the Chrysomonadida consisting of forms which are prac- 

 tically in a permanent Palmella-stage, giving rise, however, to 

 flagellated swarmers of the cr;\'ptomonad type. The single individ- 

 uals are sometimes in gelatinous walls from which long thread-like 

 or tubular processes arise (Ncpgrliella), or sometimes in thread-form 

 slightly branched aggregates {Phoeoihamnwn). These two types 

 form the basis for the families (1) Phseocapsidse and (2) Phseo- 

 thamnidtie. 



Order III. DINOFLAGELLIDA, Stein. 



We follow Doflein in reducing the Dinoflagellida from the value 

 of a sub-class in earlier classifications, to the present position in 

 the Phytomastigoda. The affinities of this well-circumscribed group 

 are apparently more closely with the Cryptomonadida than with 

 any other type of Protozoa. The yellow-brown color of the chroma- 

 toi)hores, the peculiar furrows, the nature and positions of the 

 fiagella, and the alga-like nature of the series of forms which are 

 permanently without fiagella, are characteristics wdth prototypes 

 or parallels in the orders already considered. 



We go farther than Doflein and follow Kofoid and Swezy, not 

 o\\\y in placing the Cystoflagellina as a sub-order of the Dino- 

 flagellida, but in removing Nodiluca from the cystoflagellina and 

 including it with Gymnodinioidae. The homologies which Kofoid 

 has recently drawn between the swarm spores of Nodiluca and the 

 Dinoflagellida are clearly sustained and there are the same grounds 

 for regarding Nodiluca as a Dinoflagellate that there are for con- 

 sidering Hydrurus a Chrysomonad because of its temporary flagel- 



