Hill W. B. TUKNER, FRESH-WATEB ALG-ffi OF KAST INDIA. 



Specim. Amer. 1. et lat. max. 165 X 24; 156 X 22; 262 X 28 fi ; comm. F. Wolle. 



Scotl. 186 X 19; 220 X 19; 280 X 20; 284 X 22 ,«; comm. J. Roy. 



Sibir. 220 X 19.5 ", Boldt 1. c. 



In the specimens witb dilated apices (by far the commoner form) t lie It. apic. 

 is 13 — 1(5.5 //, when undilated the It. apic. is 11 — 12 fi. 



There is considerable variation in si/e and general appearance of tliis ]»lant. 

 Dr. Nordstedt in litt. deems it to be the same as P. Haynaldii Schaar. (Magy. 

 Desm. j». 277, f. 2<), 1882); judging from Scandinavian specimens this niav be so, but 

 Schaarschmidtfs figure is hardly satisfactory; its si/.e is 150 X 20 ,n. 



Swedish specimens from Blekingia, et W. <Sc N. Alg. No. 574, give: 

 Long. et lat. max. 14D X 20: 152 X 27; 170 X 23; 162 X 27; 182 X 25 //. 



These are shorter and thicker and have the apices less dilated than any other 

 form of the plant I have seen; more so than the Norwegian specimens I have from 

 Orenvand (J. W. Addymax, Swedish and Norwegian Vice-consul in Leeds, legit), and 

 they are also verv different from the Scottish ones, which Mr. Roy informs me are 

 iypical, as they are not so long or so uniform in the sides. The colour of the niein- 

 brane is colourless or påle reddish-yellow (luteolo-rufescens), and the striae are 

 normal. 



Specim. Nord. long. et lat. max. 168 X 21; 194 X 20.5; 220 X 23; 226 X 22 ,«. 



I have not seen any specirnen with membrane 'brun foncé' as noted by Jacob- 

 sen, but I quoted this in the diagnosis. 



Hab. Pireland, Bark.; Scotl. Roy; Sweden, W. & N.; Norway, J. W. A.; U. S. A., 

 Wolle; Hungary? Schaar.; Siberia, Boldt]; British Burmah, Joshua. T. XXIII, 

 f. 3, 4, 5. 



A decidedly congeneric form is 



3. P. Scandinavicnm, n. sp. (Turner in litt. apud Du. Nordstedt 1887; P. spirostriola- 

 tum T. on Desm., J. K. Mic. Soc. p. 939, t. XVI, f. 26, 1885; /'. spir. rar. Wolle 

 Fr. Alg. p. 23, i. LXI, f. 19). 



P. rectum, turgidum, ad apices leniter attenuatum, medio modice constrietum, 

 apicibus rotundatis vel rotundato-truncatis valde incrassatis; costis longitudinalibus 6 

 — 8 crassis sub-parallelis spiraliter positis, et striis transversis 7 — 11 remotis (apud 

 quamque striam transversum paullo constrietum), instructum; lateribus leniter 8 — 12 

 undulatis. Membrana hyalina vel ad apices vel tota fusco-brunnea. Dimensiones: 

 Specim. Amer. 1. et lat. max. 194 X 26; 227 X 23; 260 X 31 ,«. 



Norw. » 176 X 24; 208 X 23; 219 X 27: 247 X 29 //. 



The Scandinavian plants are not so attenuate in the central part as the Ame- 

 rican ones; indeed, one of the latter was figured b) 7 me (f. 26 a, 1. c.) which I came 

 to consider was a 'double cell', i. e. not disconnected after cell-division, but I was 

 in error. This Desmid is very near to the preceding ones; I here insert it solely for 

 correction and the purpose of re-description. 



Hab. [U. S. Amer.; Norway, Orenvand, Dyrknutskjön, 3. \\'. A., Fiskeland 

 W. B. Russeli]. T. XXIII, f. 6. 



