94 KKCENT MAUKKI'ORARTA OF THE HAWAIIAN ISLANDS AND LAY8AN. 



4. POCILLOPORA LIGULATA Dana. 



Plate XVI, figs. 1, 1'-; I'lateXVII. lijis. L', L'.-; Tlatrs XVIIl, XIX, XX, XXI. 



184(i. I'orilhporo fnmm (part) Dana, ZoDpli. WWki-H Kx].!. Kxpe.i., )). 528 (not Ehrenbei^; 



Milno Edwards). 



1846. I'ddUopora lujnlaUi Da.n'a, Znoi)h. Wilkes Expl. Exped., p. 581, pi. l, tigs. 2, 2«. 



1846. Pocillopora plicata (part) Dana, Zooph. Wilkes Expl. Exped., p. 534. 



1860. Pocillopora liijuhiUi :Milne Edwards, Hist. Nat. Corall., Ill, p. 306. 



1864. Pocillopora Uijulula Verhill, Bull. Mus. CJomp. Zool., I, p. 59. 



186ii. Pocillipom (!.<;«Tr(, Verrill, Proc. Essex Inst., \l, p. 93. 



1869. Pocillipora aspern var. lata Verrill, Proc. Essex Inst., VI, p. 94. 



1869. Pocillipora lii/ulata Verrill, Proc. Essex Inst., VI, p. 95. 



1886. Pocillopora liijulata Quelch, Reef Corals, Challenger Rept., ]). 68. 



1886. Pocillopora plicata QrELCH, Reef Corals, Challenger Rept., p. 68. 



1901. Pocillopora licjulata Studer, Zool. Jahrb., Syst., XL, p. 400. 



1901. J'ocillopora axpera, Studer, Zool. Jahrb., Syst., XL, p. 401. 



The orijrinal description of J', ligaldta according to Daua is as follows: 



Hemispherical, branches subdivided, rather remote, straight, thin (2 too lines), much compressed 

 and complanatc, \ to Ij inches wide, verruc;e small, ascending, and a])pressed to the branch, obsolete 

 at apex. C'oralhim having the cells short stellate, columella very distinct, and united by one of the 

 lamelUe to the side of the cell. 



******* 



This species is peculiar in its thin-compressed branches, and small appressed verrucifi, rather 

 distant and sometimes running in longitudinal carinate lines. The intervals between the branches 

 are from i to % of an inch wide, and give an open apjiearance to the clumps. It has the habit of the 

 plicata \n its distant verrucic and cell, but the branches are very much narrower. 



Professor N'erriil in lSt>9 published a redescription of the type specimen of the 

 species. His description is: 



In mode of branching and form of the verruca? they resemble some forms of P. aspera, though 

 the branches are more regular and unusually divergent and distant. The longer branches are much 

 compressed, thin, and mostly dilated at the ends, 0.4 of an inch to 1.5 broad, and 0.3 to 0.4 thick. 

 The larger branches have very cellular naked summits; some of the younger branches are strongly 

 verrucose at the end. The lateral verrucje are well developed, not crowded, ascending, and mostly 

 partially appre.ssed to the surface. The lateral cells are rather distant, quite small, mostly stellate, 

 with twelve well-developed septa, one of which joins the small prominent columella. The ccenen- 

 chyma is firm, between the cells covered with small spinule-like grains. The specimens are about 6 

 inches high and broad. 



Hawaiian Islands, Rev. Mr. Baldwin. 



This species is evidently closely allied to P. aspera, from which it differe chiefly in its smaller and 

 more distant cells, more fully developed septa, and the finer granulation of the ccenenchyma. With 

 a larger series of specimens it might perhaps be possilile to unite the two, but as yet I have observed 

 no intermediate forms. 



The original description of P. aspera, by Verrill, is as follows:" 



Corallum branching much as in the preceding [/'. ilan:r Verrill], forming dense hemispherical 

 clumps, often more than a foot in diameter, often having a rather rough ragged appearance, owing to 

 irregularity of the branches and prominence of the verruca?. Branches very variable in different 

 examples, and often even in the same specimen; sometimes (piite slender and not more than half an 

 inch in breadth and varying in length from 1 to 4 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, 



"Proc. Essex. Hist., VI, p. 94. 



