152 SEAWEEDS 



(gametangium) on a short stalk surrounded by the 

 end branches. In Botryoplwra there is also no 

 incrustation, and the habit is similar but more lax, 

 the plants being larger and the branches not so 

 densely packed together. The sporangia are lateral 

 and occur several together on the base of the 

 branches. They contain a large number of spores with 

 membranes, which may be gametangia, but no 

 observation of their germination has been made. 

 There is only one species, which was originally 

 described under Dasydadus, and very probably that 

 will prove to be its true position. Neomeris has an 

 incrusted shoot of otherwise similar character to 

 Dasydadus. The lateral branches bifurcate and end 

 each in a swollen tip. These tips are arranged in 

 rows of facets externally, forming a sort of outer 

 cortex to the shoot. 



At the bifurcation of the lateral branches and 

 between them, occupying morphologically the 

 summit of the original lateral branch, there is a 

 single oval sporangium, with one spore as to the 

 development of which nothing is known. Bornetella 

 differs from Neomeris in the branches being in two 

 or three successive whorls and in the sporangia 

 being of lateral origin, and containing several spores. 

 Cymopolia is of very different habit since the main 

 shoot, the axial cell, is repeatedly branched dichoto- 

 mously. It consists of chains of cylindrical, incrusted 

 portions, separated from each other by short, not 

 incrusted, joints in which the branching has its 

 origin. The apex of each branch has a terminal tuft 

 of hairs like a brush. At the incrusted portions 



