176 MADREPORARIA. 
of the terminal 2 or 3 cm. is similar to that already described, but below the elongate 
corallites are more spreading (often at right angles) and distant, about 7 mm. apart, the 
largest 1 cm. long and 3 to 3°5 em. thick, usually bearing buds either around the base or 
near the apex. Between these a relatively small number of very small nariform subimmersed 
corallites, with variously directed aperture, occur. Corallum reticulate in section near the 
apex, but becoming much denser below; surface finely echinulate, sometimes subreticulate. 
Wall porous and striato-reticulate near the apex of the colony, but in other parts dense and 
closely echinulate. The septa are in two cycles, both moderately developed excepting in the 
younger radial corallites. 
Another specimen from Malacca agrees closely with Studer’s description and figure. 
Indo-Pacific Ocean: New Guinea, Caroline Islands, Malacca. 
a. Ponapé, Caroline Islands. Mus. Godeffroy. 81. 11. 21. 9. 
6. Malacca. Capt. Belcher, R.N. [P.]. 42. 11. 30. 28. 
c,d. ? ? 93.4.7. 91 & 92. 
189. Madrepora hystrix. 
Madrepora hystrix, Dana, Zoophytes, p. 476, pl. xl. fig. 1, pl. xxxi. fig, 5; M.-Edwards & Haime, Coral- 
liaires, t. iii. p. 149; Rathbun, Proc. U.S. Nat. Mus. 1887, vol. x. p. 16; Ortmann, Zool. JB. 
1888, Bd. iii. p. 150. 
The following particulars are supplied by Dana :—Corallum low fruticose, 10 to 125 cm. 
high and 12 to 15 em. broad, consisting of several branched stems from the same base. 
Branches and corallites very divaricate and sometimes reflexed. Axial corallites oblong, 
2 mm. broad. Radial corallites unequal, 3 to 8 mm. long, scattered, tubiform or tubo- 
nariform; some are obsolescent, others proliferous, stout, but the margin not thick. 
Independent of the corallites the branchlets are only about 4mm. thick. Surface finely 
scabro-striate. 
The specimen recorded by Ortmann agrees closely with Dana’s description, but the 
corallites are more crowded than is shown in the figure. The colony is 14 em. high, divided 
near the base into four spreading branches about 10 cm. long and 1:2 cm. thick, not 
including the corallites, the lower parts provided with short tubular, subimmersed and, near 
the base, immersed corallites. The branchlets are all spreading, those of the lower part of 
the colony almost at right angles, those near the apex at an angle of 60° to 70°; they vary in 
length from 9 mm. to 3°5 em., the stouter ones are 5 mm. thick. The short branchlets 
consist of an elongate tubular corallite with two to six radiating tubular bud-corallites. At 
first the bud-corallites have a circular aperture, but the inner part of the wall is not free ; 
later, with the development of the inner wall, the corallites become more spreading. The 
axial corallites usually have a diameter of 2 mm., but in a few of the more elongate 
branchlets the diameter may be 3 mm.; the margin is distinctly rounded. Radial corallites 
tubular and very spreading, 2 mm. diameter and up to 5 mm. long if simple, those which 
are longer bear buds. Occasionally one which bears only 2 or 3 short buds may be 1:2 cm. 
long. Corallum rather porous near the apex of the colony. Surface dense and finely 
