APPENDIX. 
Family VI. ECTOCARPACE^. 
ECTOCARPUS TESSELATUS. 
This plant having been alluded to under fig. 95 as raised to the dignity of a species, it 
is necessary to add here that Dr. Harvey does not allow its claims to any other position than 
that of a varied form of E. grximdosus (fig. 95) ; a species very irregular in its habit of 
growth. Sometimes it is alternately branched throughout, as appears to have been the case in 
the plant from which the figure in English Botany was taken, or it is alternately branched in 
the larger divisions, and exactly oppositely in the lesser ones, as figured in the Phycologia 
Britannica; or the last branchlets are secund^ i.e. set along one side of the penultimate ones, 
like the teeth of a comb. And this is the case with the pretty form E. tesselatus, first 
discovered by the Eev. F. W. Hayden in rock crevices on the rugged surface of Filey Bridge, 
at the further extremity. And as this secAind branchleting occurs on both alternately- and 
oppositely-imwc/zec? specimens, it would seem that these varieties of habit are of little 
importance. 
The oppositely-branched is commonest on the south coast, and the alternate, or alternato- 
opposite, in the north. But they are found conversely. Dr. Cocks furnished fine alternato- 
secund to his Algarwn Fascicidi from Plymouth ; and opposito-secund^ with occasional double 
pairs, was gathered off a buoy at Whitby this year (1862). Filey Bridge affords the three 
varieties. 
The peculiarities of E. tesselatus appear to be the secund branchlets ; a beautiful ^ree?^-olive 
colour, and a richness and closeness of branching quite unknown in the larger forms, wliich 
often become straggling and have long portions of their stems naked. In a collection it will 
be well to call this plant Ectocaipus granulosus^ var. secundatus — a name bestowed upon one of 
the secund forms by Lyngbye ; and as Agardh unites under E. gramdosus the oppositely- 
branched Icetus^ the collector may, if he pleases, subdivide the three forms by separate titles. 
The epithet tesselatus is equally applicable to all, for it was suggested by the tesselated 
appearance of the fruit ; but this can only be observed under a very good microscope. The 
Whitby specimens, before alluded to, were furnished, besides the usual fruit, with globular 
bodies, having the appearance of spores inclosed in a hyaline cell. These were seated for tlie 
most part on the stems, the tesselated fruit on the branchlets. It is admitted by all, that the 
fructification of the Ectocarpi is very imperfectly understood ; the tesselated formations not 
having the usual characters of spores. 
RED GROUP. 
Family VII. RHODOMELACEn:. 
EYTIPHLAiA OXYACANTHA. 
A most delicate and lovely form discovered by Miss Turner in Jersey, in 1855, and pro- 
visionally called B. oxyacantha by Dr. Harvey. He is unwilling, however, to subdivide species 
unnecessarily, and has satisfied himself that this attractive little plant is but a slender and 
graceful variety of Bytiphlcea thuyoides (fig. 101). Its general appearance is much less stiff 
and formal than that of the usual B. thuyoides, for the branchlets, instead of being short, and 
rebranchleted with another set shorter still, are longer and simpler, being rarely rebranchleted 
at all. It seems hard not to allow so* interesting a variety a special name, but almost as much 
difference may be observed in the stiffer or slenderer forms of Polysiphoma parasitica as 
between B. oxyacantha and the coarser B. thuyoides. 
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