172 CoLLINs AND Howe: SpEcIES OF HALYMENIA 
less developed conditions these radiating arms seem to lose them- 
selves among the ordinary filaments of the medulla, but in older 
well-developed states some of these radiating arms may be traced 
directly to other ganglia, which thus form an interconnecting 
system. When a portion of the thallus is crushed on a glass slide 
and the other parts are reduced to a confused mass these ganglia 
and their rays often persist with little change. Septa in these 
enlarged specialized filaments are distant and irregularly placed. 
We have seen but few tetraspores and these were apparently not 
very well developed. Cystocarps have not been observed, al- 
though hundreds of specimens have been examined with the hope 
_ of finding them. In one lot of material, however, from Grasmere; 
we found small red spots resembling cystocarps under a hand lens, 
but these spots were apparently caused by the irritation of some 
endophyte or.through injury by some small animal. 
Halymenia bermudensis evidently finds its nearest ally in the 
little-known H. floridana J. Ag.,* with the type of which, as also 
with the Peruvian Sebdenia heteronema M. A. Howe,t it shows 
more or less agreement in having usually rather conspicuous sub- 
stellate medullary ganglia. It differs, however, from H. floridana, 
which is now known only from southern Florida and from neat 
Beaufort, North Carolina (W. D. Hoyt), in its darker color (roso- 
lane purple rather than pinkish vinaceous), in its commonly more 
lobed or dissected thallus, in its rather firmer texture, in its thicker, 
firmer, and less monostromatic cortex, and in its possible loss of 
sexual reproduction. Although, in a general way, the two species 
show a similarity in the medullary ganglia and the dimorphous 
medullary filaments, a critical comparison shows certain points 
of difference in these organs. The ganglia are less numerous 
less conspicuous, and less obviously anastomosing in H. bermir 
densis. The arms on leaving the ganglion commonly taper away 
gradually, usually without a septum or obvious interruption of the 
protoplast; in H. floridana, the arms usually taper towards the 
ganglion and usually have a septum or a wide interruption of the 
protoplast near the place of emergence. As a result of hee 
" Alg. 59. 1892 Howe Bull Torrey Cl : Mem. Torrey 
: : f ub 38: 511. 1911; 
Club 15: 164. 1914. oh geek 
T Loe. cit 
