CHAR A. >4 1 



#* Stem of one central and many cortical tubes (cells). 

 f St. ivith one row of cortical cells to each branchlet. Dioecious. 



3. C. canes' cens (Loisel.) ; st. slender coarsely striate densely 

 beset with setaceous patent clustered spines, branchlets 8 10 

 short, stipulodes long 1 , bracts 7 10 whorled slender equal usually 

 exceeding the narrowly oblong nucules of 10 12 spires. J. of 



B. xviii. t. 208. C. crinita (VVallr.) ed. viii. St. rigid, but 

 little branched, rarely incrusted, pale green. Branchlets stout, 

 6 8-jointed. Pools near the sea, rare. E. I. 



ft St. ivith 2 rows of cortical cells to each branchlet. 

 a. Monoecious. 



4. C. vulgar is (L.) ; st. finely striate, primary cortical cells 

 less prominent than secondary and bearing the few small spines, 

 branchlets 6 9 their upper part without cortical cells, stipu- 

 lodes sniall blunt, bracts on inner side of branchlet exceeding 

 the ovoid nucule of 12 or 13 spires. E. B. 336. C. fcetida 

 (Braun) ed. viii. Primary cortical cells collapse as they dry and 

 so place the spines in furrows. Very variable ; (C. longibracte- 

 ata Kiitz.) branchlets and bracts much longer j (C. decipiens 

 Desv.) [var. papillata (Wallr.)] spines many spreading long- 

 deciduous, secondary cortical cells very prominent ; ( U, sub- 

 verticillata Nordst. MS.) branchlets spreading with long upper 

 naked joints, not incrusted and few spines, dark green (hardly 



C. atrovirens Lowe); (C. crassicaulis Schl.) stout, branchlets 



stout connivent often \ naked, bracts short ovate, spines obsolete. 



own as iu 



E. S. I. 



[Var. melanopyrena (H. & J. G.) ; nucleus black instead of brown as in 

 other forms.] Universal. V. VI. 



5. C. contrdria (A. Br.) ; st. finely striate, primary cortical 

 cells more prominent than the secondary and bearing the spines 

 or tubercles ; branchlets 6 9 coated nearly throughout, stipu- 

 lodes blunt [or acute], bracts 4 (?) scarcely exceeding the nucules 

 of 12 or 13 spires and a conical contracted [or spreading] crown. 

 [J-. ofB. xix. (1881), t. 224, 2.] -Much like C. fcetida. Spines 

 more acute, ultimately on ridges. [/?. hispidula (Braun) ; spine-cells 

 prominent spreading. y. C. denudata (Braun) ; st. weak and as well as 

 the brauchl. almost entirely ecorticate. J. of _B. xxxiii. (1895), p. 290, 

 t. 350. A hybrid with sp. 6 occurs in the Norfolk Broads.] Lakes, 

 pools, and ditches, [y. Westmeath.] VI. VIII. E. S. I. 



6. C. his'pida (L.) ; st. stout thickened upwards rough 

 spirally striate, secondary cortical cells larger and more promi- 



