201) KKCENT MADKKl'DliAKIA OF THE HAWAIIAN ISLANDS AND LAYSAN. 



speiMiiion iiiitunil size and o-ives both its size, and mode of <,n-owth. Uii the other side, 

 or inside, the free portion is only about 87 nnn. in height. The tissues are continu- 

 ous in <rro\vtii. witiiout indication of superimposed layers. 



Calices polvjionjil, excavated, of moderate depth, from 1.25 to 2 nun. in diame- 

 ter, 1.5 is probai)lv the averao-c; compared to those of the other closely related forms 

 thev are larjre; the calicular margins sharp edged. The walls really are rather 

 thick, and are compact for Jhrltex, Imt the outer ends of the septa are narrow and 

 the margins slope to the pali. The edges of the walls are beaded by only moderately 

 prominent denticles. 



The sloping margins of the septa have been noted; between a pahis and the 

 wall arc usually two or three, and sometimes four, rather obtuse denticles. A longi- 

 tudinal section, however, shows that there is only one septal trabecula; one or two 

 processes from this trabecula may produce dentations and the same ma}' occur on 

 the mural trabecula. In the undamaged calices a peripheral zone of synapticula can 

 be indistinctly distinguished: when the calices have had their walls broken down, a 

 clearly developed ring of peripheral synapticula, separated by interspaces from the 

 wall, is seen. The septal faces are slightly rough; interseptal loculi narrow. 



Tiie pali present as slight, rather low thickenings on the inner ends of the septa; 

 they are not |)rominent: tlie formula is complete, and they are united b}' a palar 

 ring of synapticula. 



The I'ohimclla is a low-compressed style, situated in a pit surrounded l)y the 

 inner edges of the pali; it is joined by radii to the septa, and the whole columella 

 tangle is almost compact. 



The suumiit calices siiow no noteworthy diti'erence from those of the sides, 

 except their walls are not so elevated, causing a Hattening between the calicular 

 cavities. The calices near the lower edge of the living portion present no special 

 peculiarities. 



Tjiadit'ies. — Kahana, Oahu, receixcd from Dr. W. T. iirighaiii: ^Vaiklki, Oaliu, 

 .1. v.. Duerden. collector. 



Type.—(\i. No. 2l>243, U.S.N. M. 



7?^^////'//'/Ix. -Notwithstanding the apparent distinctixe dirtercnces between this 

 forma and lornia lacera., intermediate specimens exist, the two forma? gi'ading into 

 each otiier: it also passes into tlie typical form of the species. 



PORITES LOBATA forma PARVICALYX, new. 



The corallum is composed of connected, ascending, compressed, tiat-topped lobes. 

 The type consists of two lol)es. with undulations and longitudinal ridges on their 

 surfaces. The specimen has been ln-oken from a larger mass and does not show the 

 base. Height, 108 mm.; greatest width, '.Ht mm.; width of wider lobe. T-t mm.; 

 width of narrower lol)c, 71 nnn. The wi<lcr lobe has a free end i:! nun. tall, the 

 other has none. 



Calices jjolygonal, deep, small, usually 1 nnn., or may be somewhat less in diam- 

 eter, separated by tall walls. The succeeding description is based upon some of the 

 lateral calices and particidarly some of those near the lower limit of the living por- 

 tion, as these show the skeletal elements in their most developed condition. 



