CHARA ACULEOLATA. 49 



Habitat. — Lakes, pools, pits and ditches in peaty 

 districts. 



Distribution. — England : Rare, occurring in a few 

 scattered areas. Somerset, N., Suffolk, E. & W., Nor- 

 folk, E. & W., Cambs, Lines, N., Lanes, W., Yorks, 

 S.E. & N.E., Westmorland, Cumberland. 



Wales : Anglesea. 



Scotland : South and South-east, Kirkcudbright, Wig- 

 ton, Selkirk, Roxburgh, Fife. 



Ireland : Widely distributed, especially in the centre. 

 Kerry, N., Cork, E., Tipperary, S., Limerick, Tipperary, 

 N., Kilkenny, Carlow, Queen's County, Galway, S.E., 

 W., N.E., King's County, Kildare, Wicklow, Dublin, 

 Meath, Westmeath, Roscommon, Mayo, E. & W., Sligo, 

 Monaghan, Armagh, Down. 



First record : Plulsenet, 1692. 



Outside the British Isles C. aculeolata occurs in 

 Sweden, Denmark, Germany, Switzerland, Hungary, 

 France and Italy. 



A medium-sized or large plant (about 20-30 cm. in height), 

 with stout firm stem and rather short branchlets, so that the 

 internodes become relatively long, in the lower part of the stem 

 sometimes as much as four times the length of the branchlets. 

 The branchlets are usually straightish, but sometimes consider- 

 ably incurved. 



The spine-cells are usually more strongly developed than in 

 most other species. Dr. A. W. Hill has shown that extra cells 

 are produced at some of the nodes of the cortex, between the 

 node-cell and the spine-cells (see Vol. I, p. 35, f. 10). The spine- 

 cells are long and slender and acute, and occur usually in groups 

 of 3-4, but in weak forms some are solitary. Occasionally 

 adventitious bract-cells are produced below the normal ones. 



G. aculeolata is usually much incrusted, when the plant has 

 a remarkably rigid habit. Superficially it resembles some forms 

 of C. hispida, but the much larger primary cortical-cells and the 

 secondary cortical-cells joining obliquely and overlapping one 

 another, so that the cortex is partially triplostichous, serve 

 readily to distinguish it. It is also stricter in habit, the branch- 

 lets are shorter and it is more spinous, and the spine-cells are 

 much less deciduous. 



VOL. II. 4 



