i:i 



2 KKCKNT MADKKl'oKAKIA OK TllK HAWAIIAN ISLANDS AND LAYSAN. 



near tlu' ,irruiuf,-iv,ue; tho«. (.f the last eyele, wl.i.li have a ragged appearance owing to the size and 

 ahiinihm.e ..f their granules, can lie .listing.iishe.l ..iily near the eireuniferenee and are smaller and 

 less salient than those of the other cycles. 



Septa and pali profusely ornamented with spinifnrm grannies. The septa are m six systems and 

 four complete cycles, hut in some of the half-systems a fifth cycle is developed. The septa of the 

 firet cycle are large and exsert, and each, with its pahis, remains [.erfirtly independent of all the other 

 septa and pali. The septa of tlie last cycle are small, independent, and without pali. The septa of the 

 second and third cycles (and those of the fourth, also, in the half-systems in which a fifth C) cle occurs) 

 are as large as those of the first, but their pali (which are larger and farther from the center than the 

 pali of the first cycle) soon unite to form "deltas." These "deltas," owing to the size and abundance 

 of their granulation, have a lace-like appearance. 



Columella sunken, concave, spongy-papillose. 



Color of the living corallum, madder tinted. 



Diameter of corallum about IS mm. 



A single specinuMi, from the .\ndaman Sea, 172-.'>03 fathoms. 



yoies on the llawaihtn spedmeiifi. — Tlio iiioasurement.s of the two specimens 

 obtained by the Alhatrosx. 1!»()2, are: (1) diameter, 1(» mm. ; heij,dit, 3 mm. ; (2) diameter, 

 1'2 mm. ; height, 3.5 mm. Tliese specimens are smaller and apparently younger than 

 Alcock's tvpe. The basal sear of detachment is not completely healed, and the costai 

 can be traced nearer to the center than in the type. The last cycle of septa rather 

 constantly fuse to the sides of the next older cycle. In the smaller specimen some 

 of th(> youn^^est septa appear to have fre(^ inner maryins, but I suspect that thi.s 

 appearanc(^ may lia\(> been l)rotight about, in some instances at least, by the break- 

 ing down of till' connection with the older septa. There are four complete cycles, 

 with some members of a fifth. 



There are many hundreds of specimens of DdtovijdtJinx italicus (Michelotti) 

 in the I'nited States National Museum, and a careful comparison has been made 

 between them and tlie Hawaiian specimens. No evidence of intergradation was 

 found. The former very ('onstantly has four cycles of septa. 



Locnllty. — West coast of Hawaii Island, Station 40^15; depth, 147-198 fathoms; 

 bottom, coral sand, foraniinifera; tem])eratiire, 4'.» F.; 2 specimens. 



Genus TROCHOCYATH US Milne Edwards and Haime 



The following species bears the same relation to the discoid Trochociiufhl that 

 D'aimrh doe.s to Fuinjm. 



TROCHOCYATHUS OAHENSIS, new species. 



Plate VI. ligs. 5, .'vi, (I, (in. 



Corallum small. Hat, transv(>rsely slightly elliptical. 



MICASUREMENTS. 



Specimen 



(ireater diameter 

 Lesser diameter. 

 Height 



4 



3.5 



2 



No. 2. 



5.5 



2.5 



"New individual being formed at one corner. 



