A. E. Verrill — Corals of the Genus Acrojjora. 231 



moderately thick and lips rounded ; calicle small (about 1'"™), with 

 12 septa distinct. 



Radial corallites irregularly arranged, crowded and exsert on the 

 upper side ; loosely arranged below, and less exsert ; on the smaller 

 branches more regular and ascending, nearly adnate, but not ap- 

 pressed. On the larger branch they stand at angles varying from 

 W° to 60", and sometimes form oblique rows. They are verruci- 

 form, conoidal, or tubo-conoidal, with thickened walls and swollen 

 base ; summit usually obliquely truncated, with the small calicle 

 opening upward ; but sometimes it looks downward, or sideways, 

 and often it is terminal. 



Length of the larger radial corallites, mostly 3 to 4™'" ; diameter 

 at base, about S"""" ; calicles, 0.75 to 0.80""". 



The distal end of the radial corallites is usually free for 1 to 3"^", 

 with the inner lip well formed, but some are entirely adnate, with no 

 free inner lip. No immersed calicles occur on this specimen. 



The radial corallites are strongly stellate ; the six primary septa 

 are well developed, but narrow, thick next the wall, subequal ; the 

 secondaries are much smaller, but distinct. The whole surface is 

 uniformly and densely covered with fine rough granules. 



The type is a single stout branch, 100™™ long, with one side branch 

 20™"' long. No. 6155, Mus. Yale Univ. Australia (coll. Ward). 

 The rest of the specimen, on which I made my notes several years 

 ago, may now be in the Field Columbian Museum, Chicago. 



This species is remarkable for the unusual density of its coenen- 

 chyma, and for its conoidal radial corallites. 



Acropora Luzonica Ver., sp. no v. 



Plate XXXVI C. Figure 4. Plate XXXVI F. Figure 9. 



Coral arborescent, distantly, loosely, and irregularly branched, 

 Avith the branches often forked, mostly ascending, but some are 

 widely divergent and often crooked. The terminal branchlets taper 

 gradually to rather slender tips. Principal branches are mostly 12 

 to 15™™ in diameter at base; terminal ones ai'e 6 to 10™™ thick at 

 base, and up to 60 to 75™™ long. Their tips are subacute, truncate, 

 with the axial corallite 2 to 3'"™ in diameter and 1 to 3™"' exsert, 

 walls are not very thick, reticulate-porous, and strongly costulate. 



The radial corallites are mostly entirely or nearly immersed, on 

 all the larger branches ; some of them have slightly raised, thin 

 margins ; others have the lower lip a little prominent ; their calicles 



