238 



Chlorophycew 



pyrenoid, but which I am inclined to believe is a small granule of 

 starch. In some cells starch appears to be quite absent. The 

 outer surface of each family of cells is enveloped in a tough elastic 



membrane of irregular form, 

 which contains a trace of 

 cellulose, and is folded and 

 produced into all manner of 

 irregular wrinkles, lobes, pro- 

 cesses and spines. Sometimes 

 these irregular projections are 

 wanting, but at other times 

 they are exceedingly nume- 

 rous. The membrane is a 

 secretion of the underlying 

 cells, and its presence renders 

 observations on this Alga 

 more difficult than on any 

 other of the Protococcacese. 

 Sometimes the smaller colo- 

 nies are united by more or 

 less rigid prolongations of the 

 enveloping membranes into 

 much larger colonies. 



The families multiply by 

 division, forming larger and 

 larger colonies, which ulti- 

 mately become separated into 

 smaller groups by the develop- 

 ment of elongated processes 

 of the enveloping membranes. The reproduction is unknown 1 . 



In situations in which Ineffigiata occurs in quantity, such as 

 in the freshwater plankton, the cells develop the brick-red oily 

 material which is found in the preceding genus. 



/. ncglecta W. & G. S. West is one of the most widely distributed of British 

 Algie, occurring in all kinds of situations in ditches, bogs, tanks, water- 

 butts, etc. and forming a regular and considerable constituent of the fresh- 

 water plankton. Diam. of single families 21 56 ^, of colonies 46 350 p ; 

 length of cells 5'7 10'5 M , breadth 3'4 5'3 /* ; fig. 107. 



1 Vide Journ. Bot. March, 1903, t. 447, f. 16. 



107. Ineffigiata neglecta W. & 

 G. S. West, from Harris, Outer Hebrides. 

 A, outline of colony ; B, smaller colony ; 

 C, part of single family in section; D, 

 showing escape of cells from a small 

 colony. 



