520 BULLETIN OF THE BUREAU OF FISHERIES. 
Occasional on Bogue Beach, Beaufort, N. C., summer and autumn, sometimes fruiting. 
Two distinct forms, a thin, membranaceous one and a thicker, more gelatinous one, have previously 
been included under this species. Although both these forms seem to be represented under the name 
“ Halymenia floridana”’ in Herb. Agardh @% the concensus of opinion seems to be that the thin form 
should be considered as the type, and the thick one has accordingly been separated by Collins and 
Howe (1916) under the name Halymenia gelinaria. 
The present species (figs. 45 and 46) has a rather thin, membranaceous texture; the structure is 
fairly dense, the cortex consisting of one or usually two layers of medium-sized cells apparently formed 
from the ends of filaments, bounded by a definite cuticle; the medullary portion is densely filled with 
jelly and is traversed by rather scattered, irregularly branched filaments, segmented occasionally, but 
not conspicuously, the majority of these being small but mixed with occasional larger filaments, both 
kinds being irregular in size, anastomoses appear infrequent and inconspicuous in section; in surface 
view the surface appears composed of small, roundish-angular cells situated close together; a subepi- 
dermal view seen from the surface shows conspicuous anastomoses of filaments and numerous hetero- 
morphous ‘‘stellate ganglia’’ apparently formed from the enlarged ends of the larger filaments, from 
which radiate filaments running parallel with the surface and frequently fusing with similar filaments 
from other similar ganglia; the color is rather dark, rose or purplish pink. 
This species is distinguished from Halymenia gelinaria by its thinner, more membranaceous texture, 
its denser structure, its small cells seen in surface view, its heteromorphous ‘‘stellate ganglia’’ seen in 
subepidermal view, and its more rosy color. Its cystocarps also appear to the naked eye smaller and 
denser than in H. gelinaria. 
From Chrysymenia agardhii, which it somewhat resembles, it is distinguished by its more mem- 
branaceous texture and its thinner, denser frond, with smaller cells and more numerous internal fila- 
ments. It is distinguished from Callymenia reniformis (Turn.) J. Ag., with which it has often been 
confused, by its thinner, more membranaceous, less gelatinous frond, with denser, more regular 
structure. 
This is the northern known limit of the species and of the genus. 
Genus 2. Grateloupia Agardh. 
Grateloupia, Agardh, 1822, p. 221. 
Frond flattened, dichotomously or laterally branched in the plane of the flattening, 
primary frond sometimes simple or irregularly divided, often irregularly proliferous 
from the margins and sometimes from the flat surfaces; structure filamentous, inner 
(medullary) layer composed of thin, segmented, reticulately anastomosing filaments, 
sometimes rather lax, inner cortex moderately thick, lax within, gradually passing over 
into the medullary portion, outer cortex rather thick, composed of vertical, moniliform 
filaments; tetrasporangia scattered over the frond, embedded in the outer cortex, 
cruciately divided; antheridia arising from the outer cortical cells, forming patches over 
the surface of the frond; cystocarps scattered over the frond or forming irregular groups, 
small, inconspicuous, entirely sunken within cavities in the cortical layer, communicating 
with the exterior by an opening formed among the cortical filaments, bearing numerous 
carpospores in irregular groups radiating from a central point. 
About 35 species, mostly in warm seas. 
KEY TO SPECIES. 
Fronds decompound-pinzate, narrow linear, 0.5 to 2.5 mm. wide................ 1. G. filicina (p. 521). 
Fronds rather simple or irregularly divided, finally pinnate from the margins, main axis 0.5 
(Oo NEL 0 Py 5 (0 “Arg RS RAPIER RES RL DRMOY ge ea io RE es ae a eh 2. G. gibbestt (p. 521). 
@ The author is indebted to Dr. Marshall A. Howe for information regarding specimens placed under this species in Herb. 
Agardh. 
