TRIBE I. ASTR.E A C E A. 317 



III. Oririmis inconsjncuis, nullis medianis seriatis. 



6. POLYPHYLLIA PILEIFORMIS. (Dana.) 



\ 



P. subhemispherica, pikiformis, superne ampliter rotundata ; juniore 

 inversfi, late patelliformi. Corallum tenue ("), fragile; lamellis 

 undique solitariis, 2-3'" longis ; oririmis nullis nusquam conspicuis. 



Very large, nearly hemispherical or cap-shape, at top very broadly 

 rounded ; young specimens broad dish-shape. Corallum thin ( 

 of an inch), fragile ; Iamella3 every where solitary, 2 to 3 lines long ; 

 no distinct oririmes in any part. 



Plate 21, fig. 4, lamellae, natural size. 



Feejee Islands. Exp. Exp. 



In one specimen, of this species, the top of the hemispherical cap 

 is nearly flat for three or four inches in breadth, and hence, when 

 young, it has at first the shape of a nearly flat disk. In this respect 

 it resembles the pelvis, but there is no median trench, as in the adult 

 specimens of that species : the lamella? are throughout solitary. The 

 largest individual in the collections is ten inches in one diameter and 

 eight in the other, with a height of five inches : inverted it looks like 

 a large dish of this depth. It is very fragile, and of quite even 

 thickness throughout, with the under surface striate and strongly 

 scabrous. 



7. POLYPHYLLIA GALERIFORMIS. (Dana.) 



P. conico-hemispherica, pikiformis, superne anguste rotundata; juniore 

 inversa, bene pocilliformi. Corallum tenuissimum (J"), fragile ; 

 lamellis undique solitariis, l-2"' longis, oririmis nullis nusquam 

 conspicuis. 



P. conico-hemispherical, cap-shape, with the top narrow ; young spe- 

 cimens inverted neat cup-shape, hemispherical. Corallum quite 

 thin (\ of an inch), and fragile; lamellae every where solitary; 1J 

 to 2 lines long ; no distinct oririmes in any part. 



80 



