104 KKCKNT MADKKI'iiKAUIA (>1< IIIK HAV\•AIIA^f ISLANDS AND LAYSAN. 



Columcllii luodiM-atcly developed, fulse, coiiiposed (if fu^^ed septal trabeculte. 



ZocrtZ/ViV-.s.— '•Saiulwich Islands," Dana; Laysun, Studer. 



Reefs, Kaunakakai, Island of Moiokai ('J s])eeiineMs); and Hawaiian Islands, no 

 more derinik- locality (I specimen). A/ /hi tn '«■■<, 1'.MI2. 



Kahana, Oaliu. •_' speciiiieiis; Pukoo, Molokai, 'A specimens; Kaneohe, Oahii; 

 1 specimen without locality lal)el; depth, 3 to 6 feet; received from W. T. Brigham; 

 Waikiki, Oahii, and Pukoo. Molokai, J. E. Ducrden, collector. 



There are It! specimens in the United States National Museum, and I was able to 

 exatnine other sp(>cinlen^ in tiie Yale rniversity Museum. 



Family FANllD.K (Iregory. 



Genus CCEUASTREA Verrill. 



186(). OckiMrcii Vkkuii.i., I'roc. Essex Inst., V, p. :i2. 

 (h'ujimil de><<ri/)/i(in of fhi' geinis. — Accordinj;' to \'eriill this was as follows: 



Coraihun iiiiissive, cellular, fasciculate, formed by prismatic corallites intimately united by their walls, 

 which are thin and simjile. The exterior of the coralluni is destitute of an epitheca, lobed, and dis- 

 tinctly oostate like that of Metastrea. The cells are polyjronal, often closed below by the dissepiments, 

 w'hich, occurring at the same level, unite from all sides, forming thus transverse septa. In a transverse 

 section traces of a very rudimentary and loose columella are seen in some cells. Septa in three or four 

 cycles, unequal, the inner edges prolonged into strong paliforra teeth. 



The polyps increase by fissiparity, and near the margin by disk-budding. This genus appears to 



hear the same relation to floiiiastrm that Melaslrca does to Prionastreu, differing from it in the absence 



of epitheca and the lobed and striated exterior, thinness of the walls, and rudimentary columella. 



From Melantrca it differs in the last character, and in its. mf)de of increase as well as in the coincidence 



.of the dissepiments an<l the strong pali. 



As this gimus is based on a sino-le. species, which supposedly cauie from the 

 Hawaiian Islands, t lie generic description is given. 



CCELASTREA TENUIS Verrill. 

 Plate XXVI, figs. L', 2a. 

 180(>. Calaslrca tenuis Vekku.l, Proc. Kssex Inst., V. p. 33. 



Oru/inal deHcrlptint,. — This species was originally de.scribed by Verrill as 

 follows: 



Coralluni somewhat c-uhnunar or turbinate, Hat :', tnp, attached by a narrow base; the sides are 

 marked by lobes corresponding to the marginal corallites, and striated even to the base; the ribs a 

 little jironiinent, finely echinate near the cells. Cells unequal, irregularly polygonal, mostly closed 

 by a complete floor below. Walls very thin, forming a zigzag line between the septa. Septa very 

 narrow, thin, finely serrate, the inner edges perpendicular, little exsert, not crowded, in four cycles, 

 the last often incomplete. Pali prominent, wide, thicker than the septa, situated before all the cycles 

 except the last. Columella not apparent except in a section, where it appears very rudimentary. 

 Dissepiments horizontal, about a tenth of an inch apart, mostly coincident, so as to form complete 

 tranverse floors. 



Height, 2 inches; diameter, 3; the average width of cells, 2. 



Sandwich Islands? I'mf. .1. I). Dana, U. S. Ex[)l. Kxp. 



Type.—OAX.. No. 47f>. Yale Universitv Museum. 



