94 VEKRILL, SYNOPSIS OF 



Corallum branching much as in the preceding, forming 

 dense hemispherical clumps, often more than a foot in 

 diameter ; often having a rather rough and ragged appear- 

 ance, owing to irregularity of the branches and promi- 

 nence of the verrucse. Branches very variable in different 

 examples, and often even in the same specimen ; some- 

 times quite slender and not more than half an inch in 

 breadth and varying in length from one to four inches, 

 strongly compressed at the ends, or even tapering ; more 

 commonly much and irregularly subdivided, the ends 

 enlarged and variously lobed, and often conspicuously 

 verrucose at summit ; sometimes the branches are stouter, 

 less subdivided, compressed, one to two inches in breadth, 

 three to six thick and three to five long, some with the 

 ends verrucose, others scarcely so. The lateral verruca 

 are generally distant, irregular, often elongated, rising 

 very obliquely, or more or less oppressed to the surface ; 

 in other cases small, but little prominent, or even sub- 

 obsolete, especially below. Cells large, those at the 

 summit much crowded, deep, separated by thin walls ; the 

 lateral ones mostly circular, not distant, usually with a 

 jDrominent columella and twelve distinct septa, one of 

 which is wdder and joins the columella. Coenenchyma 

 between the lateral cells not very abundant, the surface 

 thickly covered with very rough, coarse, spinulose grains. 



The largest specimens are more than a foot in diameter. 



Hawaiian Islands. Horace Mann ; W. T. Brigham ; 

 J. D. Dana. 



Yar. lata Yerrill. 



Pocillopora plicata (pars) Dana, loc. cit. 



One specimen (referred to P. plicata by Dana) has 

 the branches stouter, .3 to .5 of an inch thick, and one to 

 three inches or more broad, variously plicate, with the 

 summits lobed and mostly naked, the smaller ones often 

 verrucose, but in the characters of the lateral verrucse and 

 cells it scarcely difliers from the large specimens of the 

 ordinary variety. The lateral cells, however, generally 

 have the septa less developed, and the surface between 



