MADREPOEARIA. 765 



broad theca in the centre, from which the sejjta appear to radiate ; the loculi are filled up 

 with vesicles or cells not more than -75 mm. apart and scarcely longer, extending to within 

 1 mm. of the edges of the septa; the valleys are filled up in the same way but with rather 

 larger vesicles, so that there is obviously no columella. 



The species differs from all others in its large monticules and few septa, as well as its 

 light structure. The theca is very difficult to see in section ; it is often a mere rod from 

 which the septa radiate as from a rod-like columella. 



Locality. S. Nilandu, 25/., and Haddumati, 32/ 



17. Hydnophora microcona, Lmk. Ed. and H., II. 423, and Gard., p. 744. 



There are nine specimens of this species in the collection. It is fairly common, though 

 rather local, throughout the Maldives, but scarce at Minikoi, where it was only obtained from 

 the reef-flat. The Maldive specimens were collected at Hulule, Goidu. Addu, and Turadu 

 (S. Mahlosmadulu) from reef-flat and lagoon. Colour, olive green, polj^ps noticeable for their 

 large amount of mucus. 



18. Hydnophora ?lobata (Lmk.). Ed. and H., II. p. 421. 



Two moderate sized specimens, the largest 17 by 14 cm. by 13 cm. high, may belong to 

 this species. They are extraordinarily variable on their thin edges, lobes and valleys, in 

 parts appearing to represent a lobate variety of C. iiiicrocona, but I have seen no inter- 

 mediates. 



Locality. Two specimens from the west reef of Hulule. [H. lobata niihi (p. 745) from 

 Rotuma is probably not the same species as the above specimens, though it resembles them 

 in its light texture. H. exesa mihi (p. 745) from Funafuti is probably a new species.] 



19. Hydnophora maldivensis, n. sp. (PI. I^X. fig. 12.) 



We dredged 27 pieces, all small, of an explanate coral of this genus, which I am bound 

 to refer to a new species. It comes close to H. gyrosa, Ed. and H., but the only indication 

 of lobing that it gives is in an elevation over two barnacles 15 mm. high by 12 mm. broad. 

 Even in its thickest part it is less than 10 mm., averaging in different parts 3 — 6 mm. Its 

 characters are as follows : 



Colony, explanate, thin, covered underneath to within 1 cm. or so of the edge with a 

 delicate epitheca, through which the ridge-like, untoothed costae (14 in 1 cm.) are clearly 

 visible. Monticules towards the centre of the colony more rounded and much larger, 2 — 3 mm. 

 high and 6 — 7 mm. between the valleys, passing gradually into long (6 — 7 cm. at edges), 

 slightly sinuous collines 1 — 2 mm. high and 4 — 5 mm. broad, separating .series of calices, of 

 which the centres are not visible except near the centre of the colony, where they have 

 generally 6 septa ; theca only visible in places as a thin line. Septa not exsert, near the 

 edges sloping up very obliquely on the walls of the series, subequal about 1 nnn. apart but 

 sometimes alternating with very minute septa ; teeth not noticeable near upper edges, within 

 very low, distant and blunt. Columella a few irregular, rough, twisted trabeculae from the 

 lower ends of the septa, varying considerably in amount, in some places forming a distinct 

 base to the valleys, but in others very irregularly massed, probably not a true columella. 

 In section extremely vesicular, the vesicles extending to within 1 mm. of the edges of the 

 septa and forming the monticules ; theca not visible. 



Locality. S. Nilandu, 24/ and 30/, Haddumati, 32/, and Suvadiva, 25/ 



98—2 



