180 KKCENT MA1>KKI'(>RAKI.'\ OK THK HAWAIIAN ISLANDS AND LAYSAN. 



living part, where tliere are oceasionally two, tlie outer arising in the angle between 

 the wall and the ne.xt more inwardly situated trabecula, which inclines toward the 

 eoluniella. Septal granules correspond to the septal trabeculie; usually there is only 

 one. which is detached from the wall, standing about halfway between it and the 

 palus. They vary both in prominence, size, and shape. When the calices are deep 

 they ai-e not so tall as the wall; when the calices are shallow they are of about the 

 same height. 'Vhcy may be irregularly shaped granules, narrow teeth, or platelike. 

 The septal trabecuhe wlien there is only one ring, or the outer trabecuhe when there 

 are two rings, are united by synapticula, extending higli up in the calice, and 

 detached from or fused to the wall, thus forming on the older portions of the 

 corallum a distinct mural shelf. 



The pali are often small, those before the lateral [)airs the larger, rather thin; 

 but they may be rather wide and tall. The formula is persistently complete. Palar 

 ring of synapticula complete. 



The columella is usually a rather wide, thin lamella, of moderate height, rising 

 from the flat bottom of the fossa, which is surrounded by the perpendicular inner 

 edges of the pali. There is considerable compacting around its base. 



The skeletal surfaces are covered with closely set, short, blunt granulations. 



Locality. — Reef at Kaunakakai. Molokai, AUxitross, 11H)2. 



Tyj)e.—C'At. No. :il27<;. U.S.X.M. 



Remarks. — This forma is in most respects the center of the species, binding 

 together the various foi'ma- that compose it. Its relations to the othei- fornne are 

 discussed in the concluding remarks on the species. 



PORITES COMPRESSA forma PROFUNDICALYX, new. 

 I'llUf I.XXIl, tig;^. 1, 1-/, 16. 



Corallum composed of ascending, truncate, compressed branches, coalescing 

 altundantly and forming irregular plates of considerable width. 



This foi'ma is based on four fragmentarj^ specimens, all of which may belong to 

 the same corallum. 



MEASUREMENTS. 



1" T.vpe. figured specimen. 



Calices polygonal, 1 to 2.5 mm. in diameter, usually about 1.5 nun.; excavated 

 and decidedly deep ntnir the branch summits and for considei'able distances down on 

 the .sides; separated by elevated, continuous, unusually compact walls, thin on the 



