BULLETIN ")0, fNITKI) SIAIKS XATKINAL MVSKUM. 177 



PORITES COMPRESSA forma ANGUSTISEPTA, new. 

 Plate XLVIU, ligs. 1, la; I'lato XClll, lij,'^. 1, :.', S. 



Description of fijpe spi'cin ten of tlw fortiin. — C'oralluin coinposod of iiscoiuliiig, 

 obtuse, or clavate branches, a number of which coalesce to form plates. Ileii,'ht of 

 specimen, 13cm.; depth of iiviiiir portion from 1.3 to ■!.<) cm.: leiiffth of free portion 

 of liranches from l.t) to 3.<) cm.; lesser diiimeter of bt-anciics. I.l' cm.; yii'atei-, from 

 1.35 to '2.5 cm.; width of jjiiite of five fused l)i;iiiches, s cm. 



Culices from 1.5 to ii nun. in diameter, a\erai;e alunit 1.75; deep, e.\ce[)t at the 

 hiwer edue of the living layer; separated by detinite continuous walls, decidedly 

 elevated, as much as 0.5 mm., except near the lower edge of the living layer. Walls 

 rather thick, and present a relatively solid appearance. The mmal dentii-les around 

 a calice are about twice as numerous as its septa; they are rather thick and covered 

 with closely set, thick granulations. 



The septa begin some distance below the upper edge of the wall. They are 

 rather thick, usually thicker than the widtii of the interseptal locidi, their outer ends 

 thicker than the inner. Betw'een a palus and the wall there is usually one, sometimes 

 two. se]ital trabecuhe, with corresponding dentations on each septal mai'gin. 



The septal granules are only slightly icmovcd from the wall; in fact, they are 

 actually or veiy nearl}- adherent to the wall by their outer edges. The outer ring of 

 synapticula is never complete, but it is almo'-t invariably partially represented; tho.se 

 present :\vv only slightly distant from the uall and often fuse with it. 



The pali are pronnnent. those before the lateral pairs the most prominent, 

 formula invariably complete; i)alar ring of synai)tieula usually or nearly always 

 complete. 



Columella a narrow lamella, rising from the bottom of a deep well-like fossa, 

 radially connected with the iimer ends of the septa. The himella and its radial pro- 

 jections may be considerably comparted by stereoplasmic deposit. 



The skeletal surfaces are thickly set with rough granulations of irregular shape 

 and of unequal sizes. 



Localities. — Kahana. Oahu. type and .'! other specimens; Pukoo, Molokai, 3 

 specimens, all received from Dr. W. T. Hrigham; depth. 3 to (i feet. 



Type.—C&t. No. 20915, U.S.N.M. 



Remarlis. — The 3 other specimens from Ktdiana, Oahu. all so closely agree with 

 the type and with one another in essential characters that they deserve no special 

 consideration. The branches or plates vary in width and height, but do not ditl'er 

 widely from the type. The 3 specimens from Pukoo. Molokai. however, show con- 

 siderable dillerences among themselves and from the Kahana material. One of these 

 is composed of three branches, the median bifurcating, fused into a zigzag corru- 

 gated plate 6 cm. wide and 2.15 cm. thick. The branches taper somewhat, are dis- 

 tallv free from 1 to 2.3 cm., and have obtusely rounded, not truncate, ends. The 

 branches of another specimen are divergent; they are not fused at all. The third 

 specimen is innnature. It is composed of two ascending, more or less compres.sed 

 branches, one of which is tjifunating. the other trifnreating. Height. 4.t! cm. The 

 calices average smaller than in the other specimens, about !..'> nun. The wall on the 

 32301—07 12 



