182 RECKNT MADKKPORARIA oK THE HAWAIIAN ISLANDS AND LAYSAN. 



Till' wall is thin, distinct, usually continuous; only slifjhtly elevated on the lower 

 portion of the coralluni, distally more elevated, hut not especially prominent. Mural 

 denticles fine, delicately frosted, a))out twice as numerous as the septa. 



The outer ends of the .septa are thicker than the inner ends; the septa as a whole 

 rather thick, their thickness exc(>c(linu- the width of the interseptal loculi; the latter 

 verv narrow on the l>asai portion of the coralluni. Between a palus and the wall 

 there apiiears to he a sin<;k' septal trahecula, but on the septal margin there are 

 several, two or three, delicate, minutely and very delicately frosted dentiitions or 

 spinules, which are almost as tall as the wall. Each of these denticles apparently 

 does not coincide with a trahecula, liut several may originate from the same trahe- 

 cula. Th(> outermost septal denticle often stands slightly away from the wall. The 

 inner or palar synapticular ring is normally complete; the outer or mural ring is 

 sometimes complete, and is slightly separated from the wall. 



The pali are rather tall and narrow, finely frosted, formula usually complete. 



The columella is a thin, compressed tubercle. 



All the skeletal surface are delicately and thickly spinulose, producing a rather 

 wooly appearance. 



Locality. —Kiihiinn, Oaliu; depth, 3 to 6 feet; received from W. T. Brigham. 



Coti/pes.— Cut. Nos. 20911, 20914, U.S.N.M. 



Remarks. — This forma intergrades with forma <h'ns!niurata. 



PORITES COMPRESSA forma DENSIMURATA, new. 



I'latf LXXIIl, liKM. 1, 1". 



Coralium ramose, branches compressed, of varialile width, superiorly spreading 

 somewhat or coalescent, the upper ends ai-e truncate and may be swollen, of Haliellate 

 or chnate I'onii. 



MK.\SlKb:MH;NTS. 



The three specimens here grouped together are all broken portions of coralla. 

 The l)ranches of No. 1 coalesce distally, whih? those of the two other specimens are 

 free. 



Calices polygonal, with definite boundaries, ranging in diameter from 1 to 1.75 

 mm., with an average of about l.-l, slightly less than 1.5 mm. The depth is onlj^ 

 moderate. 



The wall on the upper and median portions of the branches is slighth' elevtited, 

 sharp, and delinite. The mural denticles are relati\ely large, often coar.se, usually 



