318 DR. К. E, FRITSCH ON FRESHWATER ALGÆ 
this is in agreement with Chodat's earlier views *. It seems a little question- 
able, however, whether this is really warranted. The typical species of the 
genus Kaphidium are unicellular or colonial forms, in which reproduction is 
effected by transverse division of the contents (frequently into four), followed 
by elongation of the segments, so that they ultimately come to lie side by 
side as a number of daughter-individuals within the mother-cell (so-called 
autospore-development). "This has not been observed in Raphidonema nivale. 
On the other hand, although septate Raphidivms have been deseribed 
(e. g., №. nyrenogerum and В. nivale T), the breaking-up of the septate indi- 
vidual into two parts by fragmentation is not known for this genus. The 
resemblance of Raphidonema to Raphidium therefore appears to be purely 
superficial, and one must agree to Lagerheim’s original view { regarding the 
snow Alga as a member of the Ulotrichales, probably to be included in the 
Cheetophoracex ; the peculiar method of vegetative reproduction may, how- 
ever, indicate a relationship to Stichococcus §, and until more is known about 
Raphidonema its exact position must remain doubtful. 
Very rarely forms were found of. the type shown in РІ. 10. fig. 34. This 
shows a single cell of the Raphidium-type (diam. 2 р) with a prominent 
central pyrenoid. This is probably a species of. /'aphidium, possibly №. pyre- 
nogerum, which is distinguished by having а pyrenoid, but Chodat’s species 
appears to be much broader. Т have seen too few individuals to be sure of 
the specifie determination. 
Filamentous forms are poorly represented in the yellow snow Нога. The 
most abundant is Ulothrix subtilis, of which relatively short filaments were 
always to be found (РІ. 11. phots. 1, 2, & 6) embedded among the numerous 
unicellular and colonial constituents. Next in abundance comes Raphidonema 
nivale, which has already been considered. Lastly, very occasional filaments 
of a broad species of Gvdogonium (diam. cell= 20 p) with well-marked caps 
were observed. 
The remaining Alew found in the yellow snow are very rare. These 
include forms like Pleurococcus vulgaris, Menegh., Mesoterntum Endlicheri- 
anum, Naeg., Chlamydomonas caudata, Wille, Nostoc minutissimum, Kütz., 
and probably other species of Chlamydomonas. Lastly, mention must be 
made of large round cells with a smooth and fairly thick membrane and filled 
with yellowish-red or reddish, homogeneous or somewhat granular contents 
(text-fip., D, р. 323); the contents were commonly slightly contracted 
* Chodat, “Flores des neiges du col des Ecandies," in Bull Herb. Boissier, iv. 1896, 
р. 886. It does not seem that Chodat's R. nivale is in any way allied to Ruphidonema. 
t Chodat, * Algues vertes de la Suisse,’ 1902, p. 200, fig. 120. 
I Ber. Deut. Bot, Ges, х. 1892, p. 523, 
$ Cf. Lagerheim, loc. cit. pp. 523, 524. 
