241 



one direction, so that the cells are grouped irregularly within 

 a cylindrical mass of mucus. This cylindrical mucous envelope 

 frequently branches, each 

 branch being similar to the <?&? 3 



_ OQD^tx*-, n^yooV 



primary mucous cylinder. 



P. varium Nag. (inclus. P. 

 subramosum Nag.) is a common 

 British Alga in peaty ditches 

 and in bog-pools. Diam. of cells 

 6'5 9'5 fj.; diam. of cylindr. 

 mucous investment 11 '5 33 p.; 

 fig. 108. 





 



Genus Schizochlamys 

 A.Br., 1849. The cells are 

 globular or slightly ellipsoid, 

 with a firm cell- wall of some 

 thickness, and they are ir- 

 regularly disposed within an 

 indefinite j elly . The chloro- 

 plast contains no pyrenoid. 

 The outer portion of the 

 cell-wall commonly becomes 

 ruptured, being cast off 

 either in one piece or in 

 four distinct pieces, which 

 are held in a position some- 

 what remote from the cell 

 by the intervening jelly. 

 It is the formation of this 

 large quantity of gelatinous 

 material that causes the 

 rupture of the firmer part 

 of the cell-wall. Multipli- 

 cation occurs by division 

 into two or four daughter-cells, usually subsequent to the rupture 

 of the outer layer of the cell-wall. 



Fig. 108. Palmodactylon varium Nag., 

 A C, from Esher Common, Surrey; D, 

 from Strensall Common, N. Yorks. A, x 100 ; 

 B D, x450. 









O 



Fig. 109. A B, Schizochlamys gelatinosa 

 A. Br., from Loughrigg, Westmoreland. C, 

 Sell, delicatula West, from near Bowness, 

 Westmoreland ( x 450). 



S. gelatinosa A. Br., in which the outer layer splits in four pieces, occurs 

 in ditches, ponds, etc.; diam. of cells 9'5 15 p.; fig. 109 A and B. S. deli- 

 catula West is also a frequent species, in which the outer layer is thrown off 

 in one piece; diam. of cells 5-8 6'7 /*; fig. 109 C. S. gelatinosa usually 



W. A. 16 



