MADREPORARIA. 759 



find few other species — to venture on an}- determination of the species. The corallites of my 

 specimens are extremely variable, but most show the star- of the above species formed by the 

 six primaries. The genus appears to me to be a very doubtful member of the Astraeidae, 

 and would probably repay morphological investigation (both corallum and polyps). 



Locality. Common under overhanging coral or rock masses of the boulder zone, reef- 

 flat and lagoon reefs throughout the Maldives (not Minikoi). The corallites are only found 

 in comparative darkness, and appear to shun the light. Polyps colourless. 



III. Genus T^-idacophyllia . 



3. Tridacophyllia lactuca (Pallas). Dana, p. 195, IX. 10. 



A single specimen from S. Nilandu, 30/!, and a smaller piece, Felidu, 20/!, seem to 

 belong to this species as understood by Dana. The surface of the first is so distorted by 

 worms and capsules of Pyrgoma, standing up for 1 — 2 cm., that identification is extremely 

 difficult. 



IV. Genus Eiiphyllia. 



4. Euphyllia glabrescens (Chamisso). Ed. and H., ii. p. 192 and Gard., p. 73-5. 



The specimens differ from the Rotuma ones in that the septa very seldom rise above 

 the wall. Fission takes place by a pinching in and fusion of the two opposite walls of an 

 elongated corallite. The calices are often much distorted by the round tubular dwellings of 

 Pyrgoma. 



Locality. The colonies of this species may generally be found in hollows towards the 

 inner side of the reef-flat <ir in protected situations, where there is no sand or mud, both 

 at !Minikoi and throughout the Maldive group. Where it occurs, as to the S. of !Hulule, it 

 is exceedingly abundant, but is nowhere a reef-builder. Colour, dull green. 



5. Euphyllia turgida (Dana). Dana, p. 167, and Ed. and H., ii. p. 193 (and Ann. 

 des Sc. Nat, t. x. pi. 6, fig. 1, 1848). 



Three branched specimens with calices varying up to 4 cm. long by 2 cm. broad, closely 

 agree with Ed. and H.'s description and figure, especially the section. The septa are 

 scarcely exsert, and the corallites have a tendency to be constricted round their open ends. 



Locality. North Male, 28/, and S. Nilandu, 36/ 



V. ? Genus MycetophyUia, Ed. and H. 



6. A small specimen with five calicular centres may belong to this genus. It presents 

 a striking resemblance to Ed. and H.'s figure of M. lamarckana (Ann. des Sc. Nat, t. x. 

 pi. 8, fig. 6a), and does not agree with the young specimens of Mussa that I have seen. 



Locality. Suvadiva, 40/, bottom covered with coarse rubble. 



