IM KKIKNT MADKKI'OKAKIA OF THK IIAVVAIIAN ISLANDS AND LAYSAN. 



Aci'ordiiijT to Professor Stiulor"s tiyiiri' the jiapillii' may .sometimes fuse together 

 laterally, thus foi-iuinj^- short, more or less coneeutrie rulffes. The arrangement of 

 the ])iii)ill;e is more striUiiiuly roiucntric than radial in the illustration. 



Prof. W. T. Briu'liam has sent me one speeimen from Kahana, Oahu. and another 

 from I'ukoo, Molokai. olilaiiied at a depth hetween :; and t! feet. 



6. MONTIPORA STUDERI, new species. 

 I'hitr I.XII, liirs. I, L': I'liilc I. XIII, li-. 1. 



CoraUnin a thin lamina. Ihe iare'er specimen shows no si^n of having been 

 attached, tiie smaller is broken along one edge, and may have been detached from an 

 object of supi)oi-t. The margin of the lamina is more or less scalloped, and may be 

 somewhat bent, (ireater distance across larger specimen, 114 mm.; width of median 

 portion, 80 mm. ; length of smaller specimen, 59 mm. ; width, 31 mm. Thickness of the 

 edge of larger specimen, '2 to 2.5 mm. ; in central poition, about 6 mm. ; of small sjieci- 

 men, at free edge, 2 mm.; thickest part of broken edge, i mm.; in other places 

 along that edge, 1 to 2.5 mm. The upper surface is somewhat humpy and undu- 

 lated; the lower surfa<'e shows, inversely, the same irregularities. Under side cov- 

 ered by an epitheca that extends to the edge of tlie lamina, with only a very narrow 

 peripheral margin not invested by the epitheca. The epithecal surface is very 

 mimitely concentrically striate. 



The ealices are almost entirely confined to the upper surface; in some places a 

 few may be crowded in between the growing edge of the corallum and the edge 

 of the epitlieca, but when these are present they present no special peculiarities. 

 Calices of the upper surface minute, 0.5 to 0.6 nun. in diameter, not hidden, 2 to 4.5 

 mm. apart. There are two larger directives septa, one standing opposite the other, 

 four smaller primaries, and very often, if not usually, tlie second cycle is com- 

 plete. The length of the larger septa is about one-fourth the diameter of the calice. 

 The directives sometimes meet in the bottom of the calice, which is rather deep. 

 The calieular mouths may occur on the flat ctenenchymal surface; they may be situ- 

 ated on the distal end of a papilla or, in a few instances, are on the ends of tubular 

 elevations. 



The cieiienchymal surface has flat areas and j)apilliform protuberances. The 

 papilla' radiate outward, their outer ends falling abruptly to the level of the general 

 surface, while the slopes on their inner sides are gradual. In the larger specimen, at 

 the appai-(>nt center of the corallum some of th(; papilhe rise pei'pendicular to the sur- 

 face. The same may occur on the humps. The length and height of the radiating 

 papilhe are veiy variable; one measured 9.5 mm. in length and was only 1 mm. high 

 at the distal (Mid; 2.5 nun. is about th(> maximum height, 1.5 to 2 mm. probably the 

 average. The papilhe have a rather indefinite concentric as well as a radial arrange- 

 ment; in some instances they are rather clo.se together, the intervening coenen- 

 chyma rising to a higher level, making a short tiansversely corrugated ridge. The 

 papilhe are in close relation to the calices. ,V calice occurs at the distal end of 

 every one, sometimes at the foot of the abrupt downward slope of the outer end, 

 but very often f)ne is situated above the level of the general c<enenchvraal surface 



