MAEINE ALG^ OF THE 'SEALAIIK' EXPEDITION. 131 



penicillis Dast/ojjsis Geppii ; fills stlchidia In aplclbus pedlcellorum brevlum 

 monosiplionlorura. clrcumdantibus. Stichidlis sporls numerosls. Cystocarpiis et 

 antlieridiis ignotis. 



Amiraute, 20-25 fins. ; in alcoliol. 



Chagos Archipelago, Solomon Island ; in alcohol. 



Coetivy, reef ; in alcohol. 



Dasyo2)sis imlmatijida resembles in essential points X>. Gextpiiy but its frond is far 

 more deeply palmatifid and the different segments often terminate in a cylindrical 

 branch. These fasten themselves to any hard object and produce at that spot a little 

 tubercle, which much resembles the thick pedicel of D. Geppii. I have considered 

 the question whether J), palmatifida might not be the stichidia-bearing form of 

 I). Geppii t but have been unable to solve it. In addition to its deeply palmatifid frond, 

 J), pahnatifida differs also from D. Geppii in the size of the filaments forming the 

 penicilli ; these cells having a length of 104-106 /* and a breadth of 12-20, 3G-40 /i.. 

 Stichidia with tetrasporangia are borne at the base of the penicilli on monosiphonous 

 pedicels ; they have a blunt apex. 



Tapeinodasya, Weber-van Bosse* 

 1. Tapeinodasya Ethels, n. sp. (Plate 13. figs. 22, 23.) 



4 



Thallo procumbente, constante e sympodio bilaterali ; tertio quoque segmento aut 

 ramulum lateralem spinosum incremento finito ferente, aut ramulum lateralem 

 spinosum incremento sympodiali infinito. Bamulis adventitiis pra^terea ex axillis 

 ramulorum spinosorum emergentibus sed parvis etiam adultis. Axi constante 

 e cellula centrali cum quattuor cellulis pericentralibus ; quo numero vcrumtamen 

 cellularum pericentralium in segmentis ssppe majore ob concrescentiam ramulorum. 

 Axi centrali cellulis corticalibus, peripheriam versus diminutis, cincto. Hyphis 

 numerosis in parietibus inter cellulas pericentrales nascentibus. Organis fructi- 



ficationis ignotis. 



Amirante, 20-25 fms. ; dry and in alcohol. 



Tapeinodasya EthelcB is the second known species of this genus; the type, T. Bojvietii, 

 being described in the 'Recueil des Travaux botaniques N^erlandais/ Ko. 1, 1904 The 

 plant from Amirante differs in having a less dense ramification, which is, as a rule, 

 bilateral. The branches have the outward appearance of little spines. At the top of 

 the main axis they point outwards in three directions, but immediately below the 

 growing-point the branches stand in two rows. In my preparations the distance 

 between the succeeding branches in the sympodium is three cells, but I should not be 

 surprised if in parts of the frond the distance amounted to only two cells, as in 

 the other species, T. Bornetii, the number is known to vary. The branch that is 

 displaced ends in a spine ; it is either of definite growth and develops no further, or of 

 indefinite growth, in which case it may give rise to a lateral sympodial branch. The 

 branches grow congenitally with the main axis for one or two segments, and in a 

 cross-section through such a scj?ment a greater number of pericentral cells is visible. 



n" Ol^VX^ « ^V;, 



2 



