Stat. ij. /°28'.5S., ii 5° 28' E. 1060 m. 1 Ex. 

 Stat. 18. 7°28'.2S., ii5°24'.6E. 1018 m. 7 Ex. 

 Stat. 212. 5 54.5 S., I20°I9'.2E. 462 m. 1 Ex. 



In none of these specimens are the costae so prominent as they are in specimens from 

 Indian Seas. 



The specimen from Station 212 is singular in having the corallum elongate and com- 

 pressed. with the lateral costae sharp and almost cristiform, and the septa increased innumber; 

 it. however, has all the look F. japonicum from which I am not inclined to separate it. 



Distribution. Off Japan, Java Sea, Bay of Bengal and Arabian Sea. 



XIX. Placotrochus Edw. & H., Duncan. 



47. Placotrochus Candeanus Edw. & H. 



Placotrochus Candeanus Milne Edwards et Haime. Ann. Sci. Xat. Zool. 3 sér. IX, 1848, 

 p. 283, and Hist. Xat. Corall. II, 99. 



Stat. 12. 7°I5'S., H5°I5'.6E. 289 m. 1 Ex. 



Distribution. China Sea, Java Sea. 



XX. Placotrochides n. gen. 



Two small dead and somewhat broken coralla of the "Siboga" collection might be 

 referred to Placotrochus E. & H., but for the presence of a large fascicular columella almost 

 as abundant as that of Caryophyllia. From Platytrochus E. & H. they are separated by the 

 absence of the characteristic lateral costse, and by a certain, apparently normal, irregularity 

 of growth. 



Corallum simple, compressed, free (or attached ?), indistinctly costate. A pellicular epitheca 

 may be present. Columella essential, elongate, ancl fascicular. Septa little exsert. Xo pali. 



4S. Placotrochides dcutiformis n. sp. Plate IV. Fig. 31, $\a. 

 Stat. 59. io°22'.7S., 123° 16'. 5 E. 390 m. 1 Ex. dead. 



Corallum free, simple, compressed, acutely wedge-shaped, fairly elongate, curved in the 

 plane of the major axis apparently in consequence of increased growth at one end. 



The costse, which correspond in number with the septa, are almost worn away, but 

 appear to have been low, broad, and equal — except that 01/c of the lateral costae seems to 

 have been more prominent than any of the others. 



The calicular orilïce is ovate, not regularly elliptical : the axial diameters are as 3:2, 

 and the major axis is on a slightly lower plane than the minor. 



The septa, which are coarse, are in six systems and three cycles with a fourth cycle in 

 a few of the half-systems. Those of the lïrst two cycles are the largest and reach the columella, 



SIBOGA-EXPEDITIE XVI O. 5 



