52 KECKNT MADUKl'OHAKIA nK TlIK HAWAIIAN ISLANDS AND LAYSAN. 



next largest (sixth cycle) dn nut (IoscctkI (luite hull' way ilown the calicular wall, and the four smallest 

 (iiiconiiilele seventh cycle) are very short. The surfaces of the sejita are finely, sharply, and some- 

 what sparsely granular, ami their eil{;esas they descend in the calicle become sinuous, e8i)ecially in 

 the case of the lartrer septa. The columella, which is deep-seated and narrow, is formed hy small 

 trabeeuhe from tlie 48 lar<;e septa of the lirst four cycles. 



Greatest height of corallum, 39 nun.; maxinuim diameter, 47 mm. 



This species is, evidently, nearly related to F. pavoninnm, but the corallum iorms an arch of more 

 than three-<iuarters of a circle and the septa are nearly twice as numerous. 



Locality.— 5"^ 28'.4 S., 132'- 0'.2 I-:.. 204 ineter.s, 1 .speciiiK^n. 



A fomparison of Alfock's description with the table for typical F. ])avoninum will 

 show that the chai-acti'is l).y whieli laiiiclhihmnn can be .sepai-ated iroiw pa roninuni tj-p- 

 ical are reduced to ouc, the basal angle exceeding 180'- . Specimen No. 9 of that table 

 has ;52ti septa, with 48 principals; specimen No. S. which is of nearly the same size as 

 Alcock's type, has 2(i<» septa. Some specimens show a tendency for the basal angle 

 to exceed 180'^. Therefore I believe th(> /'". himellomin should be included in F. jxivo- 

 iiinum and {-onsidered tiie extreme of its variation in one direction. No specimen of 

 this variety' was found by the Alhatrosx on the Hawaiian expedition. 



FLABELLUM PAVONINUM (typical). 



riatc 1, liL's. L', -la. 21,, S, 3(i. 



1831. Plabdlum pavoninum Lesson, Ulustr. Zool., jil. .xiv. 



1846. Euphyllia pnioiniid D.vna, Zooph. Wilkes Expl. Exped., p. 1.59, \A. vi, figs. 5, 6. 



1857. Fkibellum pavonmum Milne Edw.\rds and Haime, Hist. Nat. Corall., II, p. 80. 



Descriptum. — In 1857 Milne Edwards and Haime described this species as 

 follows: 



Corallum fla'belliform, compressed chiefly toward the base; faces subconcave; lateral crests little 

 pronounced, almost horizontal, the obtuse angle that they form being almost 180°. Costa slightly 

 distinct. Calice strongly convex from one summit of the longer axis to the other, these .sunmiits 

 angular; the curved line of its margin circumscribes a segment of a circle larger than a semicircle. 

 The septa of the last cycle almost rudimentary; those of the first four cycles apparently equal, giving 

 the ap])earance of 4S systems with three septa each. The principal septa have their inner vertical 

 margins strongly undulated. 



This characterization is good. The following tables will V)ring out other char- 

 acters iutd al.so show variation. One character that needs special emphasis, besides 

 the ba.sal angle of the lateral edges, is that the greater diameter of the calice exceeds 

 in lengtii the height of the corralluiu. The average difference for 18 specimens is 

 10.5 mm. 



