326 Proceedings of the Royal Society of Edinburgh. [Sess. 
The record of the locality of this specimen has been unfortunately lost. 
All the other species have been recorded from the Indian Ocean. 
In some respects this species approaches Cactogorgia expansa , but it is 
easily distinguished by the characteristic shape of the colony and by the 
architecture of the anthocodial armature. 
The following table gives a summary of the differences in the anthocodial 
armature for the different species of Cactogorgia : — 
Species. 
“ Crown.” 
“ Point.” 
G. celosioides , Simpson. 
7-10 rows of curved spindles. 
1 large pair, with occasionally 
1 or 2 smaller ones between. 
G. expansa , Simpson. 
About 8 rows of curved 
spindles. 
6-8 pairs arranged en chevron. 
C. alciformis , Simpson. 
10-14 rows of curved spindles. 
10-15 spindles only slightly en 
chevron. 
C. lampas , Thomson 
and M‘Kinnon. 
6 rows of horizontal spindles. 
About 3 converging pairs of 
spindles, and between two 
“points” lies a single spindle. 
G. agariciformis , n. sp. 
22-28 rows of slightly curved 
spindles. 
4 pairs of curved spindles en 
chevron , with a few scattered 
between the “ points.” 
EXPLANATION OF PLATE. 
Fig. 1. Colony enlarged almost twice natural size* 
Fig. 2. Stalk broken across to show the large main canals ( x 6). 
Fig. 3. Polyps enlarged to show anthocodial armature ( x 35). 
Fig. 4. Spicules from the stalk ( x 25). 
Fig. 5. Spicules of the verrucae ( x 25). 
Fig. 6. Spicules of the anthocodiae ( x 40). 
Fig. 7. Spicules from the aboral surface of the tentacles ( x 85). 
( Issued separately March 10, 1910.) 
