19 
are slightly raised, later the abaxial edge grows very much more than the rest so as to form 
a scale which finally covers over the gastropore. The scale may bear one or more dactylozooids. 
The gastropores are 0,4 mm. in diameter. The dactylopores occur on small nariform projections 
(whose aperture is always towards the apex of the branch) all over the surface of the coenosteum 
but often in greater numbers along the sides of the branches, than on either surface. The 
projecting part is soon worn down in the older parts of the branches. The ampullae which 
are smooth, except for what are apparently partially closed up dactylopores, occur on both 
surfaces and sometimes on the sides of the branches, but chiefly on the “anterior’’ surface. 
The ampullae are often placed at the base of a gastropore scale. 
On some of the branches smooth spherical galls occur perforated by 5 or 6 round pores. 
When fully formed these galls are 1,5 mm. in diameter. One of these when broken open was 
found to contain a curious Copepod which has been sent to Mr Scorr for examination and 
is probably new to science. 
This species closely resembles 4. gdaéra (Pourtales) in size and method of growth, and 
in the shape and position of the gastropores. The dactylopores of Z. glaéra are however 
arranged in a row along each side of the branch, instead of more or less irregularly all over the 
surface. In the arrangement of the dactylopores, 4. ramosa is more like £. carznata (Pourtales), 
but differs from it in having a gastropore scale. 
The species may be defined; 
Hydrophytum subflabellate, ramose, delicate; gastrozooids at the bases of branches, with 
a large scale bearing dactylozooids; dactylozooids also scattered all over the corallum on 
small projections. 
2. Errina horrida sp. n. Plate II, figs. 20 and 21. 
Stat. 150. 0°6'N., 129°7’.2 E. Djilolo Passage. 1089 M. Three pieces. 
This species forms a fairly robust, irregular, non-anastomosing flabellum. The most perfect 
specimen — one that had the base of attachment intact, although the terminal branches were 
broken — was probably about 60 mm. in height. The main stem, which almost immediately 
divides into two branches, is 6 mm. in diameter, the axis at the base of the terminal branches 
0,8 mm. in diameter. The colour of the specimens is a pale brownish yellow, lighter on one 
side than on the other. The surface of the coral is similar so that of A. vamosa, but the 
minute spines are rather larger and run in more definite longitudinal rows. Dactylopores are 
scattered all over the surface, cven upon the ampullae. The abaxial edge of these pores 
projects so as to form a nariform process. They are decidedly larger and more numerous than 
in £. ramosa. The young gastropores closely resemble the dactylopores, only they are larger 
and deeper (they may be 1,4 mm. long, even when young) and have the usual pointed hirsute 
style. A branch generally develops below each gastropore, so that when the pores are older 
they are always to be found in the angles of branches. The coenosteum being flabellate, the 
branchlets are only formed along the two sides of the branches and therefore when the 
gastropores occur on the surface of the flabellum they are not protected by a branch; they 
