CHARA PRAGILIS. 63 



mally quite rudimeutary, but occasionally one or more 

 elongated. Branchlets usually c. 375 [i in diam., 

 straightisli or somewhat incurved, of 8-10 segments, 

 the upper 1-3 ecorticafce. Bract-cells normally 7, the 

 anterior pair, and occasionally also a second, developed, 

 acuminate-mucronate, usually much shorter than the 

 fruit ; bracteoles usually from f to about as long as the 

 fruit. Oogonia and antheridia solitary produced at the 

 three, rarely more, lowest branch! et-nodes. Oogonium 

 c. 800-950 [i. long (excl. cor.), 500-675 [i broad ; spiral- 

 cells showing 14-17 convolutions ; coronula c. 175-250 fx 

 high, 200-375 (i broad, connivent straight or slightly 

 spreading. Oospore ellipsoid tapering slightly below, 

 c. 550-700 (X long, 350-450 (x broad, nearly black, 

 showing 12-15 well-defined ridges prolonged downwards 

 into a cage ; outer membrane thick, laminated, semi- 

 rigid, semi-opaque, very dark brown, very finely 

 granulated. Antheridium ->• c. 500 tx in diameter. 



Habitat. — In ponds, clay-pits and canals, but not 

 apparently in running water. 



Distribution. — Fairly common in the south and Mid- 

 lands, scarcer northwards, and rare in Wales, Scotland, 

 and Ireland. We have seen specimens recently from the 

 following counties, and it probably occurs in many others. 



England : Cornwall, E., Devon, S., Somerset, S., 

 Wilts, S., Wight, Hants, S., Sussex, B. & W., Kent, E. 

 & W., Surrey, Essex, N., Middlesex, Berks. Suffolk, W., 

 Cambs, Beds, Hunts, Gloster, W., Worcester, Warwick, 

 Staffs, Salop, Derby, Yorks, N.W. 



Wales : Glamorgan, Carnarvon. 



Scotland : Edinburgh, Perth, E., Forfar. 



Ireland : Cork, W., Limerick. 



First record : Hooker, ' British Flora,' 1833 (var. 

 Hedwigii). 



C. fragilis is world-wide in its distribution, occurring 

 over most of Europe and in all the other continents. 

 Some of the Australasian forms show an approach to the 

 next species in having the spine-cells partially developed. 



