106 GIGARTINACEAE 
the difference is less than is generally conceded to occur in related | 
species such as Chondrus crispus. Тһе Peruvian plant is a little 
less flattened and is more fastigiate in its branching, its somewhat | 
narrower segments are less closely and less patently flabellate- 
dichotomous towards the apices, and its substance is rather more 
corneous when dry. Dr. Coker's 565 p.p. may be more fully char- 
, acterized as follows: 
Densely cespitose and somewhat fastigiate, 3.5-7 cm. high, 
succulent, flaccid, and often transversely corrugated below (in 
preservative fluid), corneous when dry, simple or 1-7 times 
flabellately dichotomous, subterete or lightly compressed and 2-3 
mm. in diameter at base; segments linear or linear-obcuneate, 
strongly flattened and canaliculate or occasionally subterete, 
2.5-5 mm. broad, usually 2—3 times as broad as thick, mostly 1-5 
cm. long, suberect or erecto patent, the axils somewhat rounded, : 
the apices broadly obtuse, lateral prolifications very rare; cysto- | 
carps on concave or convex faces of the segments, scattered or ` 
aggregated, 1-1.5 mm. іп diameter, finally subconic or mammiform 
and highly protuberant, the pericarp (inner involucre) well de- 
veloped. 
The delicate arachnoid vegetative structure of Dr. Coker's | 
565 is very well illustrated by Kützing's figure of the structure of 
his South African C. scabiosus (Tab. Phyc. 17: pl. 63. f. 0.). ; 
Chondrus tuberculosus was included in “Species inquirendae" | 
by J. Agardh and seems never to have been admitted to Gigartina с 
Бу him. Whether the species is to be referred to the one or the ` 
other of these two genera appears to be a matter of taste and 
opinion rather than of decisive structural characters. The cystor | 
carps are often sessile upon the main segments or semi-immerse 
as in typical Chondrus, yet (in New Zealand specimens, at least) 
they are sometimes so protuberant and carry so much vegetative 
| tissue with them that they may be said to occupy reduced ramuli | 
as іп Gigartina. Тһе Cystocarps, in their younger stages, at 
least, have a well-developed special pericarp as in Gigartina, but à ` 
similar pericarp exists also in Chondrus canaliculatus, which no one 
seems inclined to remove from Chondrus for this reason. 
The South African Gigartina fastigiata J. Ag., according to 
photographs of the original specimens kindly furnished by Рго- 
fessor Nordstedt, is a plant of much less pronouncedly fastigiate 2 
habit and of much more divergent branching than the Peruvian ` 
