260 A. E. Verrill — Corals of the Genus Acropom. 



Fiji Islands (?) or Tahiti, Yale Museum (coll. Mrs. Mills), No. 3810. 



This species has some resemblance to A. tubigera, but the form of 

 the radial corallites is different and it lacks the numerous long, 

 tubular, clustered, exsert corallites of the outer branches. The tex- 

 ture of the coenenehyma is also different and less compact. The 

 mode of branching is similar, and both have similar costulate walls 

 and stellate calicles. 



It also has some resemblance to A. delicatula (Br., pi. xxviii), but 

 the latter is more suffruticose, with more profuse and more slender 

 branchlets. The tubular corallites are longer and more numerous. 



Acropora acuminata Ver. 



Madrepora acuminata Ver., Bull. Mus. Coinp. Zool., i, p. 40, 1864. Brook, 

 op. cit, p. 38, 1893. 



Plate XXXVI D. Figure 5. Plate XXXVI E. Figure 2. 

 Plate XXXVI F. Figure 11. 



This arborescent species branches much like some specimens of A. 

 muricata, var. cervicomis. The long branches are apt to arise 

 several near together and diverge widely, tapering very gradually. 

 The larger^ branches are about 20 to 30 mm in diameter and 150 to 

 250 mra long. 



The axial corallites are of moderate size, not swollen. The normal 

 radial corallites are mostly of one form but unequal in size, widely 

 divergent, mostly standing at angles of 60° to 80°, sometimes 90°. 

 They are mostly rather large, 2 to 2.2 mrr ' in diameter, and about the 

 same in length, or 2 to 2.T5 mm , with rather open, nearly round cali- 

 cles, 1 to 1.2 mra in diameter, looking outward and upward. 



The corallites are regularly short tubular, with the end very 

 obliquely truncated or dimidiate and often slightly enlarged, rarely 

 a little compressed. Outer lip a little thickened, often slightly 

 incurved, obtusely rounded; inner lip thin, the free part not half as 

 long as the outer lip. Wall firm, strongly costulate, with small 

 pores in the grooves. Between the large corallites there are many 

 small ones of similar form, but with the calicle less oblique and lips 

 thinner. 



On the large branches there are also, in some cases, many longer, 

 spreading, gemmiferous, tubular corallites, with the calicle more 

 nearly or quite terminal. The larger of these are nearly like the 

 true axial corallites in form, about 3-4 mm long, and 2.25-2.V5 mm in 

 diameter; they mostly bear only 1-4 very small basal calicles. The 

 walls are roughly and strongly costulate. 



