Jan., 1896. RECENT WORK ON SEA WEEDS. 35 



In the main part of the work the author begins with the brown 

 seaweeds, as being the more familiar forms ; he discusses each Order, 

 with the life-histories of certain typical forms, indicating any 

 divergence that occurs in other members of the group, and giving in 

 each case the geographical distribution of the genera. He then takes 

 up the Chlorophyceae, in which plankton forms are numerous and 

 include the plants that cause the brilliant luminosity of tropical and 

 other seas. The Diatomaceae are treated as a separate sub-class by Mr. 

 Murray, for, though they are nearly related to Orders under the 

 Chlorophyceae, they are separated off from these by their brown colour. 

 Dr. Schmitz's sketch of the classification of the Florideae forms the 

 basis of arrangement for the Rhodophyceae. They are divided into 

 four orders, viz., the Nemalionaceae, the Gigartinaceae, the Rhody- 

 meniaceae, and the Cryptonemiaceae. The grouping is made to 

 depend entirely on the development and structure of the carpogonium, 

 while the vegetative characters show considerable diversity even in 

 genera placed side by side, as, for instance, Delessevia and Claudea, 

 which are both placed in the family of the Delesserieae. The 

 Cyanophyceae have been described last of all : they do not form a 

 large group, many of them being fresh-water forms. The book is 

 very fully illustrated with drawings that, with one or two exceptions, 

 have not appeared in any text-book of general botany, many of them 

 having been prepared for this volume. The coloured plates give 

 illustrations of the typical British forms of the principal Orders. 



The new forms recently described are very important, and include 

 plants from North and South America, the East Coast of Africa, and 

 the Cape of Good Hope, as well as from European shores. Mr. E. A. 

 Batters (2) publishes those found lately in Britain ; he adds two new 

 genera, Tellamia (green) and Hymenoclonium (red), and five species, four 

 of which are described for the first time. He has founded a new 

 natural Order, Buffhamiaceae, on the genus Buffhamia, one of the 

 Phaeosporeae, on account of its peculiar vegetative character, a mode 

 of classification also followed by Kjellman in his Phaeophyceae. Mr. 

 Murray, in his " Study of Seaweeds " (1, p. 87), writes regarding the 

 multiplying of Orders : " Considering how much remains to be dis- 

 covered in the neighbouring groups, it appears to be scarcely justifiable 

 to add, on grounds mainly of vegetative development, to the already 

 excessive number of orders in the Phaeophyceae." Mr. Murray has 

 carried out his own theory in this matter by sinking the Myriotrichaceae 

 into the Order Elachistaceae, while he has placed Stilophora and 

 Spevmatochnus, which had each a natural Order allotted to it by 

 Kjellman, provisionally under Sporochnaceae. 



Miss Barton (3) has made the Cape marine flora her own, and 

 her " Notes on Bvyopsis " have reference to Cape specimens ; she 

 figures and describes, for the first time, the haptera of Rryopsis 

 cupyessina, Lam., by which the younger plants attach themselves to 

 the parent stem, and thus grow into colonies of bushy tufts ; she adds 



D 2 



