617 
the downwards growing cell-rows budding off from the base of the branches has a 
quite different structure from that of the Danish specimen. In the French plant it 
remains filamentous, consisting of parallel cell-rows and it has a comparatively 
small thickness, while the cortical cell-rows in the Danish plant are early divided 
by numerous transverse and longitudinal walls, the latter being both radial and 
tangential, with the result that the cortex becomes thick and is built up of numerous 
short cells, whereas the axial cell-row is narrow (fig. 616), in contradistinction to 
Atr. hypnoides where it is very broad. Finally the cortical cell-rows of the latter 
bear numerous short simple or feebly branched filaments which do not occur in 
the Danish plant (comp. Crovan lI. c. fig. 3—5). In spite of the differences quoted 
it seems probable that the Danish plant belongs to a species related to Atractophora 
hypnoides. 
Locality. Kn: South coast of the isle of Deget near Frederikshavn. 
Fam. Rhizophyllidaceæ. 
Chondrococcus Hornemanni (Mertens) Schmitz. 
This species was first described by MERTENS in 1815 (Göttinger gel. Anzeiger 
1815 No. 64) under the name of Fucus Hornemanni. It was mentioned and described 
1819 by LYNGBYE who writes (1819, p. 35) that it was found in Øresund “ubi ad 
oram Helsingoræ hance speciem elegantem et quidem rarissimam cel. Forskaal olim 
legisse fertur”. LYNGBYE named it Desmia Hornemanni and gave a very good picture 
of it (l.c. Tab. 7 C). The original of this figure is to be found in The Botanical 
Museum at Copenhagen, labelled by MERTENS: F, Hornemanni; on the back of the 
sheet HORNEMANN has wrilten: “legit Forsk: ad oras Helsingorze’. The species was 
referred to Spherococcus coronopifolius by C. AGARDH in Synops. Alg. Scand. 1817, 
p. 30, and later united with Spherococcus Lambertü (Suhr) by J. AGARDH (Sp. g. 0. 
Il.ır. 1852, p. 641) under the name of Desmia Hornemanni (Mert.) Lyngb., which 
name is still kept in his Epicrisis, 1876, p. 357, while Kürzıng referred the species 
to the genus Chondrococcus. There can be no doubt that this Alga has not been 
found growing in the Öresund. LYNGBYE had evidently his doubts as to the correctness 
of the locality cited, and J. AGARDH wrote (1852, p. 642): “cum nave forsan trans- 
vecta?”. Scumitz (Marine Florideen von Deutsch-Ostafrika, Engler’s Bot. Jahrb. Bd. 21, 
1895, p. 171) pointed out that Chondrococcus Lambertii, which is common at the Cape, 
is specifically quite different from the true Ch. Hornemanni which occurs in the 
Northern Indian Ocean. I can fully confirm this distinction. In Ch. Hornemanni the 
pinne are generally opposite while in Ch. Lambertii the branches are alternate and 
more distant, and the frond broader. It can be imagined that the specimen described 
and figured by LyNGByE has been collected by Forsskär in the Red Sea, but that 
a confusion of labels has occurred after Forsskau’s death, during the last part 
of the journey or later. 
D. K, D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd., VII, 4. 
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