Hazen: Lire History or SPHAERELLA LACUSTRIS — 287 
able to identify his plant with any described earlier, he called it 
Haematococcus pluvialis. 
Kützing (45) rejected the genus Haematococcus and seca the 
species of Flotow under Agardh’s first genus Protococcus, and this 
name was adopted by Cohn ('53). 
Alexander Braun ('5 I), considering our species generically dis- 
tinct from Haematococcus (Protococcus) nivalis, founded for it a new 
genus and gave it the name Chlamydococcus pluvialis. 
In 1875 Rostafinski decided that this species was generically 
and even specifically identical with the “ red snow " species and 
therefore restored it to the genus Haematococcus ; he further iden- 
tified it with the Volvox lacustris described by Girod-Chantrans in 
1802, and made the new combination Haematococcus lacustris. 
Perty (52) had anticipated Rostafinski in recognizing Girod's Vol- 
vox lacustris as the commonly known species, but he regarded it 
as an animal when in the motile condition and gave it the name 
Hysginum pluviale, placing it in his class Phytozooidia. 
In 1883 Wittrock* revived for the “ red snow " species the 
name Sphaerella nivalis Sommerf. which, though four years older 
than Haematococcus nivalis Ag., had never come into general 
use. In 1886 Wittrock changed our rainwater species which he 
had previously called Haematococcus lacustrist to Sphaerella 
pluvialis.t 
It is not clear why he did not keep the specific name /acustris : 
it may be that he was influenced by the fact that Cohn ('81, '82) 
had refused to accept it, mainly on the ground that Girod's Vol- 
vox lacustris was found in salt water while the common species is 
now known only in fresh water. Finally, however, Wittrock$ 
returned to the first specific name with the combination Sphaerella 
lacustris (Girod) Wittr. 
Objection to the revival of Sommerfelt's generic name Sphae- 
rella was made by Berlese and De Toni.('87) on the ground (1) 
That the genus was poorly defined, and (2) That it would cause 
* V. B. Wittrock. Om snóns och isens flora sárskildt i artiska trakterna. Stock- 
holm. 1883. 
+ Wittrock and Nordstedt. A'g. Exsic. No. 156. 1878. 
$ Ibid. No. 733. 1886. 
4 A. Hansgirg. aan der Algen F.ora von Bóhmen. Arch. d. Nat. Land. 
v. Bohm. 65: 105. 18 
