228 THE VOYAGE OF H.M.S. CHALLENGER. 
The dark linear bodies represented as embedded in the calcareous matter 
are cavities bored by parasitic vegetable organisms, the black dots being 
spore-cavities. In one of the dactylopores a branched mycelial thread is seen 
to cross over between the tubular cavities bored in the ccenosteum. 
7. Shows the appearance presented under transmitted light by a thin horizontal 
section of the ccenosteum of a species of Millepora from Samboangan, 
Philippines, in which the pores and canal-systems have become filled with 
opaque matter. The black streaks thus shown represent the ramifica- 
tions of the canals of the ccenosare within the tortuous canals in the 
substance of the ccenosteum, and show their anastomoses with the pore 
JQ 
cavities, 
Fig. 8. Portion of a fine section of the coenosteum, as seen under Hartnach’s objective 
No. 8, eyepiece No. 3. 
The canals bored by the parasitic fungus are seen traversing the calcareous 
matter. 
At (a) the fibro-crystalline elements of the hard tissue project in a series 
of points. 
PLATE XIV. 
Various structures occurring in Millepora nodosa, 
Fig. 1. View of a group of zooids in the expanded condition. In the centre is the 
short gastrozooid, provided with only four tentacles. Grouped around are 
seen five dactylozooids. A sixth dactylozooid belonging to the group is 
omitted from the drawing for the sake of clearness. 
Fig. 2. Vertical section of the decalcified living superficial lamina. A gastrozooid 
and a dactylozooid are shown in the retracted condition. In the gastro- 
zooid one tentacle is omitted for the sake of clearness. The open spaces in 
the network of the coenosare are in the recent condition occupied by the 
caleareous network. The vessels are in places cut through, and have the 
pigmented endodermal cells exposed to view. 
E. Superficial layer of the ectoderm. 
D Z. Dactylozooid. 
GS. Gastrozooid. 
A. One of the spaces occupied by calcareous matter in the recent con- 
dition. 
B. Secondary branch of one of the canals of the ccenosare. 
O, One of the cut openings into one of the vessels. 
