437 



are quite short and filled with chromatophores ; higher up the 

 cells gradually grow longer and become nearly destitute of chro- 

 matophores; in the upper parts of the hairs the cells reach a length 

 of about 180 IJL. In the basal part the hairs are thin, their diameter 

 reaching a length of about 6 p only; higher up the hairs grow 

 thicker to about 16 p. The cells of the hairs are barrel-shaped 

 cylindrical, being a little narrowed at the cross-walls. 



The plurilocular sporangia are oblong to spindleshaped, 

 about 16 26 ^ broad and 65 IJL long. They have a short stalk 

 consisting of a single or a few cells. 



Owing to its partly endophytic way of growing and to the fact 

 that the basal filaments do not form a disc this plant differs 

 from the hitherto described species of this genus and ought 

 perhaps rather to be referred to a new genus. Nevertheless I have 

 preferred to refer it to the genus Ascocyclus, having not seen 

 much of it. 



The Hypnea upon which this plant was found was gathered 

 in the month of January near the shore in shallow water. 



St. Croix: Lime Tree Bay. 



Fa m . Myriotrichiacece* 



Myriotrichia Harv. 



11. Myriotrichia occidentalis nov. spec. 



Frons ex filis basalibus repentibus, ramosis et filis erectis 

 composita. 



Filamenta basalia ex cellulis, 20 /* longis et 10 p latis compo- 

 sita, ramis aut oppositis aut alternis et unilateralibus instructa. 



Ex cellulis basalibus aut pili, aut fila brevia, aut rarius 

 sporangia plurilocularia aut filamenta principalia oriuntur. 



Pili ca. 12 JJL lati ex cellulis hyalinis valde elongatis orti. 



Fila brevia, ca. 150 /-/ alta et 12 fj. lata, ex cellulis ca. 6 com- 

 posita, apice obtuso, rarius ramosa. 



Fila principalia monosiphonia, ca. 1 mm longa, 1824 // 

 lata; ha3C ex cellulis sparsis (nodis) fila brevia, simplicia aut 

 ramosa, opposite aut subverticillate orta gerunt. 



Sporangia plurilocularia, aut sessilia aut pedicellata, 50- 

 100 rj. longa et 12 30 p lata ex seriebus pluribus loculorum com- 

 posita. 



