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Mr. G. H. K. Thwaites on Coceochloris Brebissonii. 243 
: XXVIL —Description of Coccochloris Brebissonil, @ new species 
of the Palmellez, in conjugation. By G. H. K. "TW AITES. 
[ With a Plate. ] 
Coccochloris Brebissonit, n. sp. Frons saturate-viridis, gelatinosa, 
vix cartilaginea, effusa, nec frustulosa: cellulis subsphericis 
vel rotundato-ellipticis, minutissime granulosis: sporangiis 
oblongis. 
C. Brebissonii occurs upon the perpendicular surfaces of wet 
rocks, forming a gelatinous or slightly cartilaginous coating, se- 
parating very readily from the surface of the rock. It is of a pale 
green colour, sometimes slightly reddish. The cells are shortly 
elliptical with the ends much-rounded, and contain a minutely 
granulose endochrome of a yellowish green colour. The gela- 
tinous appendages of the cells cohere to form an apparently 
homogeneous mass, and are not separately distinguishable as in 
some species of the genus. The cells when conjugating are at 
first united by a narrow connecting tube, but this soon enlarges 
to the width of the cells. The sporangium is of an oblong form 
and transparent, containing an endochrome somewhat similar to 
that of the cells, but with the granules much larger. Imme- 
diately that conjugation of two cells has commenced to take place, 
their granules of endochrome are observed to have increased in 
size, and this increase continues until the sporangium is mature. 
During the formation of the sporangium, the original cell-mem- 
branes appear to become absorbed, and are not thrown off as in 
Cylindrocystis Brebissonii. 
Branched threads similar to those represented in my figure of 
Palmella botryoides, Grev.*, ramify throughout the gelatinous 
mass of the present species, ‘but only in one instance have I suc- 
ceeded in tracing a connexion between them and the cells, owing 
I suspect to the state of maturity of the plant. By watching the 
species attentively, I hope to be able to observe the early develop- 
ment of the plant from the contents of the sporangia. 
This well-marked species, which is I believe undescribed, I 
have the greatest pleasure in dedicating to the learned French 
botanist M. de Brébisson, to whose researches we are indebted 
for the first discovery of species of Palmellee in a state of con- 
jugation. 
EXPLANATION OF PLATE VIII. C. 
Fig. 1. Small portion of Coccochloris Brebissonit, showing the cells and 
ramifying threads. 
— 2. Cells of C. Brebissonii in conjugation. 
— 3. Mature sporangia. All magnified 270 linear. 
* Ann. and Mag. Nat. Hist. Ser. 2. vol. ii. Pl. X. 
16* 
