A. E. Yerrill — Corals of the Genus Acropora. 251 



Many of the lateral corallites are verruciform or low conoidal, 

 with a wide thick base. 



The coenenchyma and walls are nearly uniformly covered with 

 close, rough, not very minute granules. 



Bonin Islands, U. S. North Pacific Exp]. Exp. Yale Mus., No. 1687. 



Acropora striata Ver. 



Madrepora striata Ver., Comm. Essex lust., v, p. 24, 1866. Brook, p. 178. 



Plate XXXVI. Figures 4, 4a. Plate XXXVI A. Figures 4, 4a. 



Plate XXXVI F. Figure 7. 



This species is notable on account of the large size of the calicles 

 and the thin, flaring lips of the tubular corallites, which have regu- 

 larly costulate, thin walls. 



The axial and gemmiferous radial corallites are either exsert- 

 tubular or somewhat trumpet-shaped, many being distinctly widened 

 distally and 2-2.5 mm in diameter, with the wide, round calicle about 

 1.5 mm ; they are often 4-5 ram long, with thin, flaring, porous edges. 



The normal radial corallites are mostly openly tubular, about 3 mm 

 long, with the summit obliquely truncated and the inner lip nearly 

 or quite adnate, but not at all appressed nor compressed. The outer 

 lip is thin, but firm, usually somewhat excurved, so that the calicle 

 is widely open (1.5 mm ) and looks outward and upward. The coral- 

 lites mostly stand out pretty strongly, at angles of 50° to 70°. 



The septa are unusually well developed in the radial corallites ; 

 the six primaries nearly or quite meet in the center, rather deep 

 down in the calicles; the directives generally unite: the secondaries 

 are narrow, but usually distinct. 



The coenenchyma is firm, somewhat translucent, but with the sur- 

 face irregularly pitted and sharply echinulo-granulate. 



It is a handsome, shrubby or arborescently branched species, not 

 very closely allied to any other that I have seen, except A. tubigera, 

 with which it has several points in common 



Ousima, IT. S. N. Pacific Expl. Exped. Yale Mus., No. 1688. 



Acropora urceolifera Ver., sp. nov. 



Madrepora corymbosa Dana, Zooph., p. 456, 1846 (non Lam.). 

 Plate XXXVI D. Figure 3. Plate XXXVI E. Figure 6. 



Plate XXXVI F. Figure 13. 



It is remarkable that no recent writer seems to have had in hand 

 the species described by Dana as corymbosa. A part of the orig- 

 inal type is in the Yale Mus., No. 4187, labelled in Dana's hand- 

 writing. 



