Conibiiied under var. dixtinclum 

 Milne Kdwards and Haime. 



BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 51 



<*(ilk'il in tlu" present puper — 

 Angle of lateral e<lges with each nther less than l.SO°. 

 Height of coralhnn less than the length of the calico. 



Lateral edges round, not crested, may be obscurely keeled 

 near the pedicel. 

 Angle 112°, 6 cycles of septa, 24 principals, height 39 

 mm., greater diameter of calice 56 mm. /<'. latum 



Studer ; var. Idiimi Studer. 



-ateral edges acute, at least near the pedicel, often crested. 



Angle 100°-160°, (i complete cycles of septa, some mem- 



lierg of the seventh, 24 to 38 principals, height 4.3 



mm., length of calice .5.5 mm. F. pateiix Mnselcy . . . 



Angle about 90° ("not much larger than aright angle ") , 



6 cycles of septa, 24 principals. F. distinctmn Milne 



Edwards and Haime 



.\ngle 7O°-90°, 6 cycles of septa complete, or nearly 

 so, 48 principals, height 57 mm., greater diameter 

 65 mm. Septal margins excavated at the wall. 



F. <iii.ilmli' Moseley 



Height of corallum ec|uals or exceeds the length of the calice. 

 Lateral edges sharp. 



Angle 108°," 6 cycles of septa, 24 print-ipals, height 39 

 mm., length of calice 37.5 mm. F. paripavonimnn 

 Alcock var. /niriptivoniriuin Alcnck. 



A .study of the literatiuv and the >pecinieiis suhniittcd to lue k-ads me to think 

 that this protean species can best be handled l)y recognizing live varietal forms, vars. 

 hdidUulosum Aleook, parinunum typical, var. latum Studer, var. distinvtioii Milne 

 Edwards and Haime {-\-F'. patt-ns ^Moseley + I'\ att-ffrale ^loseley), and var. 

 paripavoninum Alcock. In the preceding s3niopsis the height of the corallum 

 and the length of the calice are given merely to show tlie relative measurements. 

 F. httuiii may have a wider basal angle and niort; numerous principal septa; the basal 

 angle of F. parlparo)iiNuni. is variable, and tliere may be as nianj- as 50 principal 

 septa. 



FLABELLUM PAVONINUM var. LAMELLULOSUM Alcock. 



riate I, tigs. 1, la, 1/,. 



1902. FlabeUum Idini/lidoxum .\lcock, Deep .Sea Madrepor., Sibnga Kxped., p. 30, pi. :v, figs. 28, 

 28(t, 2Sh. 



Original desc)'i,ptio7i. — Alcock's description is as follows: 



Corallum snow-white, of excessively thin and translucent texture, shaped like a widely-stretched 

 fan, its circumference being e(|ual to about 285° of a circle. There is a slender short pedicle, and the 

 lateral costR-, which arch outward and downward, are sharp and finely and irregularly jagged. The 

 two faces of the corallum are slightly concave and moderately everted, are transversed by faint radiating 

 costa;, and are very faintly marked with fine wavy transverse accretion lines. The septa, which are 

 very thin, are in the unicpie specimen 336 in number. Forty-eight largo ones of equal size divide the 

 t«licle into 48 compartment-s, each of which contains 7 smaller septa of diminishing size. Of these 

 7 septa, the largest one (fifth cycie) does not descend quite to the level of the columella, the two 



« Measured in figures. 



