THE ALGA-FLORA OF CAMBRIDGESHIRE. 58 
The arrangement of the alge in this paper is based upon a con- 
sideration of all the — work at the group, and follows with few 
deviations that which is set down in the Journal of the Royal 
eroscopical Society, 1897, “467-511. * The few alterations consist 
in ne elevation of the subfa amily Confervee to the rank of a family 
—Confervaceze—and the removal of the genus Ooldotgines from the 
family Palmellacee to the family Confervacow, reasons for which 
are given under the genus, 
Much trouble has been taken to ensure that the nomenclature 
ed n 
ae to the inaccurate nomenclature of the latest British text- 
half the lniow n British spe cies, including many 
All measurements are given in microns or pu rd p = ‘001 aan): 
Summary oF GENERA AND SPECIES. 
VARIE' 
GENERA. | SPECIES. [ann rorms. 
Floridea. 
NtYANSIACEH .........s000.- Z 1 eee 
Chlorophycea. 
a Heterogame... 5 20 — 
fae 2 4 aos 
Gonferoidow Isogame ...... 18 28 y 
Conjug. 12 97 8 
PE tit A eee cin 28 62 3 
Myxophycea. 
Horm 14 39 — 
Gircce teciase 12 21 es 
Bacillariee 82 187 34 
Total...... 124 409 47 
Of this total of 409 species and 47 varieties, 85 species and 
8 varieties have not previonsly been recorded for the British 
Isles, these being denoted by an asterisk (*) placed in front of 
em. There are wee ts aoe 7 2 varieties which are here 
described for the firs 
The localities are as under the eight areas into which the 
Fl 
These areas are certainly convenient, but hardly natural, and 
little or no significance with regard to the distribution of the alge : 
they are as follows:—1. Cambridge; 2. Royston; 3. Wine ; 
* West & G. S. West, ‘A Contrib. to the Freshw. Alg. of the S. of t England 
t M.C. Cooke, British Freshwater Alge, 1882-4; also British Desmids, 1887. 
