RHODOSPERME. 159 
characterised as purplish or rose-red seaweeds, with a stringlike, or some. 
times expanded, and occasionally somewhat leafy, frond, having roots 
generally discoid, but in some instances clasping or creeping fibres. This 
Order is the largest and most widely dispersed of the Rhodosperms, species 
Fig. 146. Stichidium of Plocamiwn, 
highly magnified. 
Fie. 147. Cordylecladia erecta. 
of many of the genera being found on the Atlantic shores of both hemis- 
pheres, in the Mediterranean, and in the Indian oceans. Some species are 
found on the north-west coast of America, and others are abundant in 
the Southern Ocean, while one species at least, which is so rare in this 
country, viz., Gigartina Teedw (Fig. 160), is considered quite a common 
plant on the south European shores, where it is frequently found in fruit— 
a fact which has never been recorded of specimens taken in Britain. Several 
of the Cryptonemiacee might be used as articles of food; the well-known 
Carrageen moss, formerly used medicinally in consumptive cases, is com- 
posed of two species, Chondrus crispus (Fig. 162) and Gigartina mamillosa 
(Fig. 161), both of which may be boiled down to a jelly, and when mixed 
with milk or meal makes a far more wholesome article of food than 
indifferent potatoes or other vegetables; and that pretty membranous 
plant, Iridea edulis, as indeed its specific name implies,is by no means 
an indifferent esculent, in spite of what some writers have said to the 
contrary, for the flavour when cooked, is, as I have found, remarkably like 
roasted oysters. The title of this Order is derived from the characteristic 
form and situation of the Favellidia of most of these plants; each 
favellidium consisting of masses of spores which are developed within 
the substance of the frond, or, as Dr. Harvey says, “ either wholly con- 
cealed beneath the surface cells, or their place is indicated by a minute 
