206 



ALG^E 



branched rows of roundish or oval spores resulting from the division 

 of terminal cells of particular branches, or produced on the main 



branches. 



LITERATURE. 



Cramer Pflanzenphysiol. Untersuch., 1857 and 1863. 

 Nageli Sitzber. Munch. Akad. Wiss., 1861, p. 297. 

 Pringsheim Abhandl. Berlin. Akad. Wiss., 1862, p. I. 



The CORALLINACE^E (Corallina, L., Melobesia, Lmx., Litholhamnion, 

 Phil., Amphiroa, Lmx., &c.) are distinguished from other marine 



^ul,!^-- ' : ' '" ^iiiaiiSbua 



FIG. 183. Corallina officinalis L. a, longitudinal section through conceptacle with tetrasporanges ; 

 b, longitudinal section through cystocarp (x 100). (After Bornet.) 



algae by their calcareous habit. Most of the species are natives of 

 warmer seas. In Corallina the thallus is at first soft and flexible, 

 but it soon becomes very hard and brittle from the deposition of 

 calcium carbonate. The red colour and branching habit give this 

 genus a remarkable resemblance to small corals, as in C. officinalis (L.), 

 the common ' coralline ' or ' nullipore ' of our southern coasts. Many 

 species of Melobesia (fig. 182), Lithothamnion, Lithophyllum (Phil.), and 

 other genera, grow as lichen-like incrustations or in the form of small flat 



