CHAPTER VI 



ORDER 2 CRYPTOMONADIDA STEIN 



THE CRYPTOMONADIDA differ from the Chrysomonadida in 

 having a constant body form. Pseudopodia are very rarely 

 formed, as the body surface is covered by a pellicle. The 

 majority show dorso-ventral differentiation, with an oblique 

 longitudinal furrow. One or two unequal flagella arise from 

 the furrow or from the cytopharynx. In case two flagella are 

 present, both may be directed anteriorly or one posteriorly. 

 These organisms are free-swimming or creeping. 



One or two chromatophores are usually present. They are 

 discoid or band-form, and may be green, bluish green, blue, 

 yellow, brown, reddish brown, or red. The nature of the color- 

 ing matter is not well understood, but it is said to be similar 

 to that which is found in the Dinoflagellida and diatoms. One 

 or more spherical pyrenoids which are enclosed within an en- 

 velope of amyloid substance are present. Nutrition is mostly 

 holophytic; a few saprozoic or holozoic. Assimilation products 

 are amyloid substances; fat and oil are produced in holozoic 

 forms which feed upon bacteria and small Protozoa. The stigma 

 is usually associated with the insertion point of the flagella. 

 Contractile vacuoles, one or several, are simple and are situated 

 near the cytopharynx. A single vesicular nucleus is ordinarily 

 located near the middle of the body. 



Asexual reproduction, by longitudinal fission, takes place in 

 either the active or the non-motile stage. Sexual reproduction 

 is unknown. Some members form palmella stages and others 

 gelatinous aggregates. In the suborder Phaeocapsina, the 

 palmella stage is permanent. Cysts are spherical, and the cyst 

 wall is composed of cellulose. The Cryptomonadida abound in 

 sea water, living also often as symbionts in marine organisms. 

 A comparatively few forms are found in fresh water. According 

 to Pascher, they are divided into two suborders: 



Motile flagellate forms predominant Suborder 1 Eucryptomonadina 



Palmella stage permanent Suborder 2 Phaeocapsina 



[92]] 



