2IO ALG^ 



is eaten in Scotland under the name of ' dulse.' Chondrus crispus (L.) 

 is known, when dried, as ' carrageen ' or ' Irish moss.' Gracilaria lichen- 

 oides (L.), which jdelds copious gelatine, known as ' Fucus amylaceus,' 

 is largely used as an article of food in Ceylon and on other tropical 

 coasts. Japanese isinglass is a product of species of Gelidium. The 





C30 0<^OcjC, Q 





pc 



Fig. 187. — Vertical median section of swelling on frond of Gracilaria conferuoides Grev, 

 f, f, cells of procarp ; fc, placental cells ; s, s, s, spores ( x 400). (After Johnson.) 



substance known to microscopists as 'agar-agar' is yielded also by 

 Gracilaria lichenoides, Eucheuma spinosa' (Ag.), and other seaweeds. 

 Several other species are employed in different parts of the world as glues 

 and varnishes. Marchesettia spongioides (Hauck) (Areschougiaceae), 

 from Singapore, has a remarkable resemblance to a sponge. 



Literature. 



Berthold — (Cryptonemiacese) Fauna u. Flora Golfes Neapel, 1884. 

 Johnson — (Gracilaria) Annals of Botany, i. 1888, p. 213. 



The SQUAMARIACE.E (Hildcnbrandtia, Nard., Cruoria, Fries, Peysson- 

 nelia, Dene., &c.) are a small group of small marine, or rarely fresh-water 

 Algae, growing on stones or on the shells of molluscs or Crustacea, or 

 attached to larger algae. The ' frond ' is expanded flat or hemispheri- 

 cal, gelatinous, membranaceous, or crustaceous, with lichen-like habit, 

 composed of a single layer of cells, or more often of short densely 



