I\ra(lrepora in the British ,]fusnu}n. 4G1 



nuliincntary. Coralluni dense, surface and wall finely 

 eeliinulate. 

 ]\Iauritius. 



Madrtpora delicatula. 



Corallum extending horizontally, branches not over 8 

 niillim. thick, laxly coalescent, but not coniplanate, and 

 bearing on the under surface numerous slender branchlets 

 almost at right angles, 1 centim. or more in length and gene- 

 rally "l-b niillim. diameter at the base, with distant appressed 

 tubular buds. Appressed tubular and immersed corallites 

 also occur between the twigs. The upper surface bears 

 slender arcuate branches not over 5 millim. thick, which give 

 rise to delicate ascending branchlets singly or in groups of 

 two or three ; these are 1'5 to 2*5 centim. long and scarcely 3 

 millim. thick at the base, apparently tapering, owing to the 

 lateral corallites being shorter near the apex. Apical coral- 

 lites 1*5 millim. diameter, usually 2*5 millim. exsert. Lateral 

 corallites rather distant, round-nariform, or labellate, 1 to 1*3 

 millim. wide and 1 to 4 millim. long ; the lip of the more 

 elongate ones is frequently a little incurved ; wall thin, aper- 

 ture round, star indistinct. Corallum very porous and fragile, 

 surface vermiculato-echinulate, wall finely striate, echinulate 

 near the base. 



Solomon Islands {Dr. Gappy). 



Madrepora diversa. 



Corallum cespitose from a broad incrusting base, 10 cen- 

 tim. high and 18 centim. broad. Branches 4'o centim. long, 

 1*3 to 1*8 centim. thick, simple or divided into two to five 

 little spreading digitiform branchlets about 2*5 centim. long 

 and 1 centim. thick, obtuse at the apex. Apical corallites 

 3*5 to 4 millim. broad, scarcely exsert. Lateral corallites 

 chiefly tubular, with a more or less oblique aperture, very 

 unequal in length and diameter, all are ascending. The 

 larger ones are 3 to 6 millim. long and 2 to 2'5 millim. 

 diameter, slightly compressed; wall thick, but only slightly 

 rounded at the margin ; smaller nariform and subimmersed 

 corallites occur between the others quite to the apex ; a few 

 are proliferous and 5 to 8 millim. in length. About 2 centim. 

 below the apex the prominent corallites are nariform or tubo- 

 nariform, with a thick and strongly convex outer wall ; at 

 the base nearly all are immersed. Star indistinct, often only 

 the directive septa are recognizable. Corallum moderately 



Ann. & Mag. N. Hist. Ser. 6. Vol viii. 32 



