D80 Fostiz anD Howe: NEw CORALLINE ALGAE 
apparent at frequent intervals in a radio-longitudinal section 
(FIGURE 2, 6 and PLATE 26; see also Corallinaceae Siboga-Exped. 
59), but the West Indian plant is rather coarser and is considerably 
different in habit as-will be seen by comparing our photograph 
(PLATE 25) with that of Z. craspedium cited above, the branches 
being more inclined to increase in size upward and anastomosing 
in a more gyrose or daedaleoid fashion. We believe it should 
bear a distinctive specific name, at least until further collections 
give better grounds for understanding the relationships of West 
Indian forms to those of the South Pacific and Indian oceans. 
Lithophyllum africanum is \ess coarse than L. Antillarum, its 
branches are thinner, and more frequently subterete or compressed, 
though sometimes dilated and rather foliar, its medullary cells 
after decalcification are firmer-walled and more rounded at the 
angles, and the short rows of enlarged cells are rare. 
Explanation cf plates 23-26 
PLATE 23 
Goniolithon acropetum, natural size ; the topmost specimen is the type. 
PLATE 24 
Goniolithon acropetum. Photograph of a sagittal section (decalcified) © 4 
tened branch, ci perithallium and portion of medullary hypothallium, magnifie 
165 diamete 
of a flat- 
PLATE 25 
Lithophyllum Antillarum, rae size, the upper specimen seen from above, the 
lower from the side; the latter the 
PLATE 26 
Lithophyllum Antillarum, Photograph of radio-vertical section (decaf 
the medullary hypothallium, magnified 165 diameters. The direction of growt 
- towards the upper left-hand corner 
) from 
wth is 
