146 COLLINS AND HEBVET. 



inclusa; lino, raro duobua ad nodum, corticatione fere liberis, secun- 

 dum ramum k>ngitudmaliter seriatis. Plate V, Bgs. 29 31. 



Minnie creeping over other algae or rock-; prostrate filaments 

 60 90 fi diam., cells \\ 8 diam. long, cylindrical or slightly con- 

 stricted at node-, attached l>y colorless, unicellular rhizoids issuing 

 one or more at a node; an erect branch occasionally issuing al a node; 

 apex of prostrate filament becoming erect and similar to an erect 

 branch; penultimate branches about 60/u diam.; cells in erect part 



not over 2 diam. long, near the ape\ less than one diam.; repeatedly 



forking; lower cells cylindrical, upper apparently very shortly clavate 

 by the growth of cortication at the upper end; cortication sharply 



marked off from uncorticated portion, the lower portion <>t' each hand 



showing a -cries of transversely elongate cells passing around the 

 central cell; the upper part of ~ 3 series of irregularly placed roundish- 

 angular cells. Protoplast uniformly granular, or with slender, paral- 

 lel, longitudinal striations the whole length of the cell; the protoplast 

 cylindrical in the lower cells, subspherical in the upper. Cystocarp 

 borne at the end of a segment of 2 5 cells, which increase in size up- 

 ward, the upper cell being twice the diam. of the lower or even more; 

 on this are home several wide-spread, few-celled involncral branches 

 with one or two cystocarps between them, the cystocarps appearing 

 terminal, but with usually an axis extended beyond them and the 

 involucre, of few cells, the basal cell 2 'A diam. Ion--, the other-, a- all 

 the cells in the involucre, hardly 1 diam. Ion--. Tetrasporangia tri- 

 partite, up to (>() ^u diam. not including the wall 8/4 thick; one. occa- 

 sionally two at a node, in longitudinal series, nearly free from the 

 cortication. 



On Gcdaxaura, Spanish Rock, April 10, 1914, Hervey, type in 

 Collins herbarium, No. 8107. Also occurring on Zonaria variegata, 

 Harrington Sound, May, on Padina variegata, Agar's Island, Nov., 

 on Thala8sia s Fairyland, Dec., Collins; on Ascothamnion, Tucker's 



Town, July, Howe. 



The peculiar form of cortication, from which we have taken the 

 Specific name, does not seem to occur in any other species. C in'uiia- 



tuiu Suhr, resembling it in some respects, has distichous branching, and 

 small tetrasporangia sessile on both sides of the branches. Specially 



characteristic of ('. transversa!* are the serrate outline- near the apices, 

 due to the -harp limitation of the cortical growth there, and the tetra- 

 spore- unusually large in proportion to the size of the frond. When two 

 tetrasporangia are formed at a node, they arc set side by side, the line 

 made by tiie series of single sporangia passing between them. The 



