498 Howe : Phycoi-ogical studies 



Utricles of subcortical Subturbinate, obconical, cor- BuUate, varying from broadly 

 layer. nucopiaeform, or clavate, funnelform to subglobose, 



35-110^ in ^maximum mostly ventricose-obovoid, 

 width, often scarcely larger 110-215// '"^ maximum 

 than the peripheral utricles. width, always much larger 



than the peripheral utricles. 



JVodal Jllafnents of the Fusing in twos or threes, often Fusing in twos, rarely in 

 central strand. somewhat coherent just threes, not coherent, the 



above the points of fusion. fusion often incomplete. 



In addition to the differences mentioned above, the utricles ot 

 the subcortical layer form a more compact flat-topped stratum in 

 H. discoidea than in H. Tuna, as will be seen by comparing figure 

 1 1 with figure I . It should be mentioned that in drying the large 

 utricles of the subcortex of H. discoidea commonly collapse and 

 are flattened against the medulla and often revive imperfectly on 

 being soaked out ; this is especially true of specimens which have 

 been long in herbaria and it doubtless explains why this striking 

 peculiarity has not received earlier recognition. 



In the firm and extensive contact of the peripheral utricles, 

 Halitneda discoidea bears some resemblance to Halimeda cutieata 

 Hering, originally described from Natal Bay, but otherwise the two 

 have little in common. We have not seen Hering's original speci- 

 men, but have examined a plant from Natal agreeing in every respect 

 with his description. In this, the peripheral utricles measure 27— 

 44// in diameter, surface view, and show no evidence of fusion ; 

 they are 60-1 10 [i long, are in close contact distally for |^-| their 

 length, are obconical or clavate, surmounted in a somewhat capi- 

 tate fashion by the coherent distal parts, which appear subquadrate 

 in a radio-vertical section. The utricles of the subcortical layer 

 are only 27—55 ji in maximum diameter, scarcely larger than those 

 of the peripheral stratum, are 2-4 times dichotomous {i. e., in 2-4 

 series), and obconical, ovoid-turbinate, or clavate. The nodal fila- 

 ments of the central strand fuse in twos and threes and are strongly 

 coherent just above the points of fusion, as well described by Mrs. 

 Gepp (/. c. I 5-17). Branches given off from the filaments near the 

 points of fusion form a compact narrow annular cushion above 

 which the filaments are naked and subtorulose. This annular 

 nodal cushion we have observed in no other species. The seg- 

 ments of H. cimcata are cuneate-obdeltoid and are almost without 



