192 KKCKNT MADRKPORARTA OF THE HAWAIIAN ISLANDS AND LAYSAN. 



Vovm-d pt7».s(r is cspociully characterized by its shallow calices and the delicately 

 and thi.-kly spiiiulosc oniainciitation of the skeletal surfaces, producing a wooly 

 appcanuuc Tlu're are usually two or more septal dentations between a palus and 

 the wall: it is doubtful, however, if they correspond to septal trabecuhe. Some of 

 the calices of forma cnnjxiKjcns near the lower edge of the living portion present the 

 same ciiaracters as do those of pllosii, except the granulations may be coarser. It 

 will beshown that /lilosa connects through dciix'uiiurata and (/ranimurata with ahaem. 



Forma (lenxiiiiiiratu has a ratiier thick, compact mural apparatus, relatively 

 large, often coarse mural denticles, and detached septal granules. This forma and 

 pilom appear to i-cpi-esent opposite ends of the series, their diti'erences are so great, 

 but there is a specimen that combines the characters of l)oth: they intergrade 

 absolutely. 



Forma ijriiniiinirata has a compact mural apparatus with irregularly shaped 

 frosted grains along the top. It has a peculiarly rough, irregular textui-e. It 

 intergrades on one hand with densimurata^ on the other with ahaciis. 



Forma clmnix shows more evidence of separateness than any other form placed 

 in the series. The compactness of its walls and septa and the depth of the calice are 

 similar to forma profHndiculijx: iiut the usually int'omplete palai- formula recalls 

 dentiimurata or compacta. It differs from the latter bj^ the absence of a complete 

 ring of synapticula binding the septal trabecuhe together. As all the skeletal elements 

 found in cJufits occur in other forma- I think is not a valid species. 



Forma compixta is only a more solid form of forma ahaeii^i, with the palar 

 formula not so generally complete. 



Forma dlr<iri<rinx\s based partly on form, partly on its shallow calices. It is 

 close to compacta and ahacun. 



Forma> I'loiKjitta and tumidd are growth forms of roiijiDigenx or dhtici/s. There 

 are specimens showing connection with the latter. 



Forma, prqfu/ii/tiriiui is practically tin' same as foinia r/mn/iifif, but with thicker 

 septa. 



Forma hreti/rciiinxn differs from iinifuiiddniui Ijy its shorter, more nodular, 

 branches. 



Quelch's Poritt'Ji hidhom, judging from the original description and Bernard's 

 subsequent remarks and ffgures, presents the same calicular characters as ahavHfi, and 

 ran l)e separated only by its growth form. 



Dana's type of 1\ comj)?v,ssa is a peripheral form; it is not near the center of 

 the specii's as fornise conjiitu/ens and cdMieux are. P. comj>?-esm typical has a compact 

 looking wall, rather compact septa, and a very imperfectly developed outer ring of 

 synai)ticula. The typical form, however, intergrades with forma ahacus. 



