EDMONDSON — PROTOZOA OF IOWA. 3 1 



Somewhat pear-shaped but changeable in form. Flagella two, 

 unequal. Yellow chromatophores usually present. 



^^Microgleiia Ehr. 



Ovate or elongate, plastic. Flagellum single. Two yellow 

 color bands usually present. 



Cryptomonadid^. 



Never amoeboid. Flagella two, very similar, color bands some- 

 times present. 



Chilomonas Ehr. 



Cryptonionas Ehr. 



'^Cyathomonas F'rom. 



Ovoid, flattened laterally. Flagella two, equal. Endoplasm 

 colorless with a row of refracting bodies near the anterior border. 



Chlamydomonadid.^. 



Body enclosed by a rigid, membranous sheath which is perfor- 

 ated for the flagella. Chromatophores present. 



CJilamydomonas Ehr. 



Families and Genera of Diniferida. 



Peridinid.e. 



With or without a shell. The cross-furrow near the middle of 

 the body. The only family represented in fresh water. 



^Gymnodinhim Stein. 



Cross-furrow encircling the body. 



'^Glciwdinmm Stein. 



Membrane enclosing the body thin, with no processes. 



^Peridiniuni Ehr. 



Membranous covering composed of polygonal plates. Processes 

 not highly developed. 



Note. — In the above classification, with the exception of Pcndinidcr, only families, 

 representatives of which have been observed to occur in this state, have been included. 



Species of the genera marked with an asterisk (*) have not so far been observed in this 

 state, but are likely to occur. 



Cla.ss, MASTIGOPHORA. 



Order, MONADIDA. 



Family, RHIZOMASTIGID^. 



MASTIGAMCEBA Schultze. 



Very plastic and changeable in form. Pseudopodia often 

 extended from the body, bluntly rounded, finger-like or pointed. 



