MR. H. N. MOSELEY ON THE STRUCTURE OF THE STYLASTERIDHL 
489 
Fig. 8. 
Figs. 9 
Fig. 9. 
Fig. 10 
Fig. 11 
Fig. 12 
Fig. 13 
Fig. 14 
Fig. 15, 
C. Space behind the wall of the upper gastropore chamber leading to the 
dactylopore tubules. 
L. Lid covering the cyclo-system. 
Pore system of Astylus subviridis laid open by a vertical incision through the 
axis and in the direction of the length of the supporting branch. 
G P. Upper chamber of the gastropore. 
G P\ Lower chamber of the gastropore. 
B. Tongue-like process of the lower border of the wall of the upper 
chamber of the gastropore, which projecting horizontally in the 
direction, in each system, of the tips of the branches, converts the 
aperture leading between the two chambers into the form of a 
horseshoe. 
A. Base of the tongue-like process and part of the wall of the upper 
chamber cut through. 
C C. Space behind the wall of the upper gastropore chamber, leading, 
as in the last figure, to the dactylopores. 
G, G. Ampullae. 
16. Diagrammatic representations of the arrangements of the gastropores and 
dactylopores in the several genera of Stylasteridse, to show the manner 
in which cyclo-systems and their pseudosepta have become developed in 
this family. 
The following letters apply similarly throughout the series. 
G Z. Gastropore. S. Its style. 
D Z. Dactylopore. 
Sporadopora dichotoma. The pores of both kinds are irregularly scattered 
over the surface of the corallum. 
Allopora nobilis. A number of dactylopores are grouped in a circle around a 
single centrally-placed gastropore. 
A system of pores from another part of the same specimen of Allopora 
nobilis. Shallow grooves run from the central gastropore to the encircling 
dactylopores, a cyclo-system being thus commenced. 
Horizontal section through the foregoing group at a slight depth from the 
surface to show the existence of styles in the pores of the dactylozooids. 
Allopora profunda. The connecting grooves between the pores of the cyclo- 
system are deeper. The system is regular, and the interval between the 
dactylopores have all the appearance of septa. 
Allopora mineacea. (Copied from Pourtales ‘ Deep Sea Corals,’ plate 3, 
fig. 16.) Here the styles of the dactylozooids are brusli-like in form, just 
like those of the gastrozooids. 
Astylus subviridis. There are no styles present in either kind of pore. The 
pseudoseptal system is complete. The open mouths of the tubular con- 
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